* [PATCHSET #upstream] block, fs: replace HARDBARRIER with FLUSH/FUA, take#2
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Hello,
This patchset is combination of the following two patchsets.
[1] block, fs: replace HARDBARRIER with FLUSH/FUA
[2] block, dm: finish REQ_FLUSH/FUA conversion, take#2
Changes from the previous postings are
* Rebased on top of v2.6.36-rc3.
* 0010-block-implement-REQ_FLUSH-FUA-based-interface-for-FL.patch
description updated to include why special -EOPNOTSUPP handling is
no longer necessary as suggested by Mike Snitzer.
* 0025-dm-relax-ordering-of-bio-based-flush-implementation.patch
description updated to include why flush_error and special error
handling logic are no longer necessary as suggested by Mike
Snitzer.
* 0013-block-initialize-flush-request-with-WRITE_FLUSH-inst.patch and
0014-block-kick-queue-after-sequencing-REQ_FLUSH-FUA.patch added.
These fixes aren't strictly required by the current users but remove
fishy corner cases.
* 0015-block-make-sure-FSEQ_DATA-request-has-the-same-rq_di.patch
added. This is needed to make requested based dm work.
* 0026-dm-fix-locking-context-in-queue_io.patch added. This fixes
locking context problem introduced by
0025-dm-relax-ordering-of-bio-based-flush-implementation.patch.
* Tested/Reviewed-by's added and patches reordered such that block
layer conversion comes first followed by block driver conversions,
filesystem conversions and then finally removal of deprecate stuff.
I think the patchset is mostly ready now although I would love to have
acked/reviewd-by's on bio-based dm conversion patches. Jens,
Christoph, how do you guys wanna steer these patches? I think it
would be best to go through the block tree but splitting parts and
doing cross tree pull/merges should be doable too.
This patchset contains the following patches
0001-ide-remove-unnecessary-blk_queue_flushing-test-in-do.patch
0002-block-loop-queue-ordered-mode-should-be-DRAIN_FLUSH.patch
0003-block-kill-QUEUE_ORDERED_BY_TAG.patch
0004-block-deprecate-barrier-and-replace-blk_queue_ordere.patch
0005-block-remove-spurious-uses-of-REQ_HARDBARRIER.patch
0006-block-misc-cleanups-in-barrier-code.patch
0007-block-drop-barrier-ordering-by-queue-draining.patch
0008-block-rename-blk-barrier.c-to-blk-flush.c.patch
0009-block-rename-barrier-ordered-to-flush.patch
0010-block-implement-REQ_FLUSH-FUA-based-interface-for-FL.patch
0011-block-filter-flush-bio-s-in-__generic_make_request.patch
0012-block-simplify-queue_next_fseq.patch
0013-block-initialize-flush-request-with-WRITE_FLUSH-inst.patch
0014-block-kick-queue-after-sequencing-REQ_FLUSH-FUA.patch
0015-block-make-sure-FSEQ_DATA-request-has-the-same-rq_di.patch
0016-block-update-documentation-for-REQ_FLUSH-REQ_FUA.patch
0017-block-use-REQ_FLUSH-in-blkdev_issue_flush.patch
0018-block-loop-implement-REQ_FLUSH-FUA-support.patch
0019-virtio_blk-drop-REQ_HARDBARRIER-support.patch
0020-lguest-replace-VIRTIO_F_BARRIER-support-with-VIRTIO_.patch
0021-md-implment-REQ_FLUSH-FUA-support.patch
0022-block-make-__blk_rq_prep_clone-copy-most-command-fla.patch
0023-dm-implement-REQ_FLUSH-FUA-support-for-bio-based-dm.patch
0024-dm-implement-REQ_FLUSH-FUA-support-for-request-based.patch
0025-dm-relax-ordering-of-bio-based-flush-implementation.patch
0026-dm-fix-locking-context-in-queue_io.patch
0027-block-pass-gfp_mask-and-flags-to-sb_issue_discard.patch
0028-xfs-replace-barriers-with-explicit-flush-FUA-usage.patch
0029-btrfs-replace-barriers-with-explicit-flush-FUA-usage.patch
0030-gfs2-replace-barriers-with-explicit-flush-FUA-usage.patch
0031-reiserfs-replace-barriers-with-explicit-flush-FUA-us.patch
0032-nilfs2-replace-barriers-with-explicit-flush-FUA-usag.patch
0033-jbd-replace-barriers-with-explicit-flush-FUA-usage.patch
0034-jbd2-Modify-ASYNC_COMMIT-code-to-not-rely-on-queue-d.patch
0035-jbd2-replace-barriers-with-explicit-flush-FUA-usage.patch
0036-ext4-do-not-send-discards-as-barriers.patch
0037-fat-do-not-send-discards-as-barriers.patch
0038-swap-do-not-send-discards-as-barriers.patch
0039-block-remove-the-WRITE_BARRIER-flag.patch
0040-block-remove-the-BLKDEV_IFL_BARRIER-flag.patch
0041-block-remove-the-BH_Eopnotsupp-flag.patch
and is on top of v2.6.26-rc3 (2bfc96a127bc1cc94d26bfaa40159966064f9c8c)
and available in the following git tree
git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc.git flush-fua
and contains the following changes. (hey, 1000 less lines!)
Documentation/block/00-INDEX | 4
Documentation/block/barrier.txt | 261 ---------------
Documentation/block/writeback_cache_control.txt | 86 +++++
Documentation/lguest/lguest.c | 29 -
block/Makefile | 2
block/blk-barrier.c | 350 ---------------------
block/blk-core.c | 72 ++--
block/blk-flush.c | 265 +++++++++++++++
block/blk-lib.c | 18 -
block/blk-settings.c | 20 +
block/blk.h | 8
block/elevator.c | 79 ----
drivers/block/brd.c | 1
drivers/block/loop.c | 20 -
drivers/block/osdblk.c | 5
drivers/block/pktcdvd.c | 1
drivers/block/ps3disk.c | 2
drivers/block/virtio_blk.c | 37 --
drivers/block/xen-blkfront.c | 47 --
drivers/ide/ide-disk.c | 13
drivers/ide/ide-io.c | 13
drivers/md/dm-crypt.c | 2
drivers/md/dm-io.c | 20 -
drivers/md/dm-log.c | 2
drivers/md/dm-raid1.c | 8
drivers/md/dm-region-hash.c | 16
drivers/md/dm-snap-persistent.c | 2
drivers/md/dm-snap.c | 6
drivers/md/dm-stripe.c | 2
drivers/md/dm.c | 400 +++++-------------------
drivers/md/linear.c | 4
drivers/md/md.c | 117 +------
drivers/md/md.h | 23 -
drivers/md/multipath.c | 4
drivers/md/raid0.c | 4
drivers/md/raid1.c | 176 +++-------
drivers/md/raid1.h | 2
drivers/md/raid10.c | 7
drivers/md/raid5.c | 43 +-
drivers/md/raid5.h | 1
drivers/mmc/card/queue.c | 1
drivers/s390/block/dasd.c | 1
drivers/scsi/aic7xxx_old.c | 21 -
drivers/scsi/libsas/sas_scsi_host.c | 13
drivers/scsi/sd.c | 18 -
fs/btrfs/disk-io.c | 19 -
fs/btrfs/extent-tree.c | 2
fs/btrfs/volumes.c | 4
fs/btrfs/volumes.h | 1
fs/buffer.c | 7
fs/ext4/mballoc.c | 3
fs/fat/fatent.c | 4
fs/fat/misc.c | 5
fs/gfs2/log.c | 19 -
fs/gfs2/rgrp.c | 5
fs/jbd/commit.c | 30 -
fs/jbd2/commit.c | 72 +---
fs/nilfs2/super.c | 10
fs/nilfs2/the_nilfs.c | 7
fs/reiserfs/journal.c | 106 +-----
fs/xfs/linux-2.6/xfs_buf.c | 16
fs/xfs/linux-2.6/xfs_buf.h | 11
fs/xfs/linux-2.6/xfs_trace.h | 1
fs/xfs/xfs_log.c | 13
include/linux/blk_types.h | 5
include/linux/blkdev.h | 85 -----
include/linux/buffer_head.h | 2
include/linux/fs.h | 28 -
include/scsi/scsi_tcq.h | 6
mm/swapfile.c | 9
70 files changed, 819 insertions(+), 1877 deletions(-)
Thanks.
--
tejun
[1] http://thread.gmane.org/gmane.linux.kernel.device-mapper.devel/12363
[2] http://thread.gmane.org/gmane.linux.kernel/1029396
^ permalink raw reply [flat|nested] 159+ messages in thread
* [PATCHSET #upstream] block, fs: replace HARDBARRIER with FLUSH/FUA, take#2
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Hello,
This patchset is combination of the following two patchsets.
[1] block, fs: replace HARDBARRIER with FLUSH/FUA
[2] block, dm: finish REQ_FLUSH/FUA conversion, take#2
Changes from the previous postings are
* Rebased on top of v2.6.36-rc3.
* 0010-block-implement-REQ_FLUSH-FUA-based-interface-for-FL.patch
description updated to include why special -EOPNOTSUPP handling is
no longer necessary as suggested by Mike Snitzer.
* 0025-dm-relax-ordering-of-bio-based-flush-implementation.patch
description updated to include why flush_error and special error
handling logic are no longer necessary as suggested by Mike
Snitzer.
* 0013-block-initialize-flush-request-with-WRITE_FLUSH-inst.patch and
0014-block-kick-queue-after-sequencing-REQ_FLUSH-FUA.patch added.
These fixes aren't strictly required by the current users but remove
fishy corner cases.
* 0015-block-make-sure-FSEQ_DATA-request-has-the-same-rq_di.patch
added. This is needed to make requested based dm work.
* 0026-dm-fix-locking-context-in-queue_io.patch added. This fixes
locking context problem introduced by
0025-dm-relax-ordering-of-bio-based-flush-implementation.patch.
* Tested/Reviewed-by's added and patches reordered such that block
layer conversion comes first followed by block driver conversions,
filesystem conversions and then finally removal of deprecate stuff.
I think the patchset is mostly ready now although I would love to have
acked/reviewd-by's on bio-based dm conversion patches. Jens,
Christoph, how do you guys wanna steer these patches? I think it
would be best to go through the block tree but splitting parts and
doing cross tree pull/merges should be doable too.
This patchset contains the following patches
0001-ide-remove-unnecessary-blk_queue_flushing-test-in-do.patch
0002-block-loop-queue-ordered-mode-should-be-DRAIN_FLUSH.patch
0003-block-kill-QUEUE_ORDERED_BY_TAG.patch
0004-block-deprecate-barrier-and-replace-blk_queue_ordere.patch
0005-block-remove-spurious-uses-of-REQ_HARDBARRIER.patch
0006-block-misc-cleanups-in-barrier-code.patch
0007-block-drop-barrier-ordering-by-queue-draining.patch
0008-block-rename-blk-barrier.c-to-blk-flush.c.patch
0009-block-rename-barrier-ordered-to-flush.patch
0010-block-implement-REQ_FLUSH-FUA-based-interface-for-FL.patch
0011-block-filter-flush-bio-s-in-__generic_make_request.patch
0012-block-simplify-queue_next_fseq.patch
0013-block-initialize-flush-request-with-WRITE_FLUSH-inst.patch
0014-block-kick-queue-after-sequencing-REQ_FLUSH-FUA.patch
0015-block-make-sure-FSEQ_DATA-request-has-the-same-rq_di.patch
0016-block-update-documentation-for-REQ_FLUSH-REQ_FUA.patch
0017-block-use-REQ_FLUSH-in-blkdev_issue_flush.patch
0018-block-loop-implement-REQ_FLUSH-FUA-support.patch
0019-virtio_blk-drop-REQ_HARDBARRIER-support.patch
0020-lguest-replace-VIRTIO_F_BARRIER-support-with-VIRTIO_.patch
0021-md-implment-REQ_FLUSH-FUA-support.patch
0022-block-make-__blk_rq_prep_clone-copy-most-command-fla.patch
0023-dm-implement-REQ_FLUSH-FUA-support-for-bio-based-dm.patch
0024-dm-implement-REQ_FLUSH-FUA-support-for-request-based.patch
0025-dm-relax-ordering-of-bio-based-flush-implementation.patch
0026-dm-fix-locking-context-in-queue_io.patch
0027-block-pass-gfp_mask-and-flags-to-sb_issue_discard.patch
0028-xfs-replace-barriers-with-explicit-flush-FUA-usage.patch
0029-btrfs-replace-barriers-with-explicit-flush-FUA-usage.patch
0030-gfs2-replace-barriers-with-explicit-flush-FUA-usage.patch
0031-reiserfs-replace-barriers-with-explicit-flush-FUA-us.patch
0032-nilfs2-replace-barriers-with-explicit-flush-FUA-usag.patch
0033-jbd-replace-barriers-with-explicit-flush-FUA-usage.patch
0034-jbd2-Modify-ASYNC_COMMIT-code-to-not-rely-on-queue-d.patch
0035-jbd2-replace-barriers-with-explicit-flush-FUA-usage.patch
0036-ext4-do-not-send-discards-as-barriers.patch
0037-fat-do-not-send-discards-as-barriers.patch
0038-swap-do-not-send-discards-as-barriers.patch
0039-block-remove-the-WRITE_BARRIER-flag.patch
0040-block-remove-the-BLKDEV_IFL_BARRIER-flag.patch
0041-block-remove-the-BH_Eopnotsupp-flag.patch
and is on top of v2.6.26-rc3 (2bfc96a127bc1cc94d26bfaa40159966064f9c8c)
and available in the following git tree
git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc.git flush-fua
and contains the following changes. (hey, 1000 less lines!)
Documentation/block/00-INDEX | 4
Documentation/block/barrier.txt | 261 ---------------
Documentation/block/writeback_cache_control.txt | 86 +++++
Documentation/lguest/lguest.c | 29 -
block/Makefile | 2
block/blk-barrier.c | 350 ---------------------
block/blk-core.c | 72 ++--
block/blk-flush.c | 265 +++++++++++++++
block/blk-lib.c | 18 -
block/blk-settings.c | 20 +
block/blk.h | 8
block/elevator.c | 79 ----
drivers/block/brd.c | 1
drivers/block/loop.c | 20 -
drivers/block/osdblk.c | 5
drivers/block/pktcdvd.c | 1
drivers/block/ps3disk.c | 2
drivers/block/virtio_blk.c | 37 --
drivers/block/xen-blkfront.c | 47 --
drivers/ide/ide-disk.c | 13
drivers/ide/ide-io.c | 13
drivers/md/dm-crypt.c | 2
drivers/md/dm-io.c | 20 -
drivers/md/dm-log.c | 2
drivers/md/dm-raid1.c | 8
drivers/md/dm-region-hash.c | 16
drivers/md/dm-snap-persistent.c | 2
drivers/md/dm-snap.c | 6
drivers/md/dm-stripe.c | 2
drivers/md/dm.c | 400 +++++-------------------
drivers/md/linear.c | 4
drivers/md/md.c | 117 +------
drivers/md/md.h | 23 -
drivers/md/multipath.c | 4
drivers/md/raid0.c | 4
drivers/md/raid1.c | 176 +++-------
drivers/md/raid1.h | 2
drivers/md/raid10.c | 7
drivers/md/raid5.c | 43 +-
drivers/md/raid5.h | 1
drivers/mmc/card/queue.c | 1
drivers/s390/block/dasd.c | 1
drivers/scsi/aic7xxx_old.c | 21 -
drivers/scsi/libsas/sas_scsi_host.c | 13
drivers/scsi/sd.c | 18 -
fs/btrfs/disk-io.c | 19 -
fs/btrfs/extent-tree.c | 2
fs/btrfs/volumes.c | 4
fs/btrfs/volumes.h | 1
fs/buffer.c | 7
fs/ext4/mballoc.c | 3
fs/fat/fatent.c | 4
fs/fat/misc.c | 5
fs/gfs2/log.c | 19 -
fs/gfs2/rgrp.c | 5
fs/jbd/commit.c | 30 -
fs/jbd2/commit.c | 72 +---
fs/nilfs2/super.c | 10
fs/nilfs2/the_nilfs.c | 7
fs/reiserfs/journal.c | 106 +-----
fs/xfs/linux-2.6/xfs_buf.c | 16
fs/xfs/linux-2.6/xfs_buf.h | 11
fs/xfs/linux-2.6/xfs_trace.h | 1
fs/xfs/xfs_log.c | 13
include/linux/blk_types.h | 5
include/linux/blkdev.h | 85 -----
include/linux/buffer_head.h | 2
include/linux/fs.h | 28 -
include/scsi/scsi_tcq.h | 6
mm/swapfile.c | 9
70 files changed, 819 insertions(+), 1877 deletions(-)
Thanks.
--
tejun
[1] http://thread.gmane.org/gmane.linux.kernel.device-mapper.devel/12363
[2] http://thread.gmane.org/gmane.linux.kernel/1029396
^ permalink raw reply [flat|nested] 159+ messages in thread
* [PATCH 01/41] ide: remove unnecessary blk_queue_flushing() test in do_ide_request()
2010-09-03 10:29 ` Tejun Heo
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel
Cc: Tejun Heo
Unplugging from a request function doesn't really help much (it's
already in the request_fn) and soon block layer will be updated to mix
barrier sequence with other commands, so there's no need to treat
queue flushing any differently.
ide was the only user of blk_queue_flushing(). Remove it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Acked-by: David S. Miller <davem@davemloft.net>
---
drivers/ide/ide-io.c | 13 -------------
include/linux/blkdev.h | 1 -
2 files changed, 0 insertions(+), 14 deletions(-)
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index a381be8..999dac0 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -441,19 +441,6 @@ void do_ide_request(struct request_queue *q)
struct request *rq = NULL;
ide_startstop_t startstop;
- /*
- * drive is doing pre-flush, ordered write, post-flush sequence. even
- * though that is 3 requests, it must be seen as a single transaction.
- * we must not preempt this drive until that is complete
- */
- if (blk_queue_flushing(q))
- /*
- * small race where queue could get replugged during
- * the 3-request flush cycle, just yank the plug since
- * we want it to finish asap
- */
- blk_remove_plug(q);
-
spin_unlock_irq(q->queue_lock);
/* HLD do_request() callback might sleep, make sure it's okay */
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 2c54906..015375c 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -521,7 +521,6 @@ enum {
#define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
#define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
#define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
-#define blk_queue_flushing(q) ((q)->ordseq)
#define blk_queue_stackable(q) \
test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
#define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 01/41] ide: remove unnecessary blk_queue_flushing() test in do_ide_request()
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo
Unplugging from a request function doesn't really help much (it's
already in the request_fn) and soon block layer will be updated to mix
barrier sequence with other commands, so there's no need to treat
queue flushing any differently.
ide was the only user of blk_queue_flushing(). Remove it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Acked-by: David S. Miller <davem@davemloft.net>
---
drivers/ide/ide-io.c | 13 -------------
include/linux/blkdev.h | 1 -
2 files changed, 0 insertions(+), 14 deletions(-)
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index a381be8..999dac0 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -441,19 +441,6 @@ void do_ide_request(struct request_queue *q)
struct request *rq = NULL;
ide_startstop_t startstop;
- /*
- * drive is doing pre-flush, ordered write, post-flush sequence. even
- * though that is 3 requests, it must be seen as a single transaction.
- * we must not preempt this drive until that is complete
- */
- if (blk_queue_flushing(q))
- /*
- * small race where queue could get replugged during
- * the 3-request flush cycle, just yank the plug since
- * we want it to finish asap
- */
- blk_remove_plug(q);
-
spin_unlock_irq(q->queue_lock);
/* HLD do_request() callback might sleep, make sure it's okay */
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 2c54906..015375c 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -521,7 +521,6 @@ enum {
#define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
#define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
#define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
-#define blk_queue_flushing(q) ((q)->ordseq)
#define blk_queue_stackable(q) \
test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
#define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 01/41] ide: remove unnecessary blk_queue_flushing() test in do_ide_request()
2010-09-03 10:29 ` Tejun Heo
` (2 preceding siblings ...)
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
Unplugging from a request function doesn't really help much (it's
already in the request_fn) and soon block layer will be updated to mix
barrier sequence with other commands, so there's no need to treat
queue flushing any differently.
ide was the only user of blk_queue_flushing(). Remove it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Acked-by: David S. Miller <davem@davemloft.net>
---
drivers/ide/ide-io.c | 13 -------------
include/linux/blkdev.h | 1 -
2 files changed, 0 insertions(+), 14 deletions(-)
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index a381be8..999dac0 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -441,19 +441,6 @@ void do_ide_request(struct request_queue *q)
struct request *rq = NULL;
ide_startstop_t startstop;
- /*
- * drive is doing pre-flush, ordered write, post-flush sequence. even
- * though that is 3 requests, it must be seen as a single transaction.
- * we must not preempt this drive until that is complete
- */
- if (blk_queue_flushing(q))
- /*
- * small race where queue could get replugged during
- * the 3-request flush cycle, just yank the plug since
- * we want it to finish asap
- */
- blk_remove_plug(q);
-
spin_unlock_irq(q->queue_lock);
/* HLD do_request() callback might sleep, make sure it's okay */
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 2c54906..015375c 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -521,7 +521,6 @@ enum {
#define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
#define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
#define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
-#define blk_queue_flushing(q) ((q)->ordseq)
#define blk_queue_stackable(q) \
test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
#define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 02/41] block/loop: queue ordered mode should be DRAIN_FLUSH
2010-09-03 10:29 ` Tejun Heo
` (3 preceding siblings ...)
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
loop implements FLUSH using fsync but was incorrectly setting its
ordered mode to DRAIN. Change it to DRAIN_FLUSH. In practice, this
doesn't change anything as loop doesn't make use of the block layer
ordered implementation.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
drivers/block/loop.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index f3c636d..c3a4a2e 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -832,7 +832,7 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
lo->lo_queue->unplug_fn = loop_unplug;
if (!(lo_flags & LO_FLAGS_READ_ONLY) && file->f_op->fsync)
- blk_queue_ordered(lo->lo_queue, QUEUE_ORDERED_DRAIN);
+ blk_queue_ordered(lo->lo_queue, QUEUE_ORDERED_DRAIN_FLUSH);
set_capacity(lo->lo_disk, size);
bd_set_size(bdev, size << 9);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 02/41] block/loop: queue ordered mode should be DRAIN_FLUSH
2010-09-03 10:29 ` Tejun Heo
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel
Cc: Tejun Heo
loop implements FLUSH using fsync but was incorrectly setting its
ordered mode to DRAIN. Change it to DRAIN_FLUSH. In practice, this
doesn't change anything as loop doesn't make use of the block layer
ordered implementation.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
drivers/block/loop.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index f3c636d..c3a4a2e 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -832,7 +832,7 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
lo->lo_queue->unplug_fn = loop_unplug;
if (!(lo_flags & LO_FLAGS_READ_ONLY) && file->f_op->fsync)
- blk_queue_ordered(lo->lo_queue, QUEUE_ORDERED_DRAIN);
+ blk_queue_ordered(lo->lo_queue, QUEUE_ORDERED_DRAIN_FLUSH);
set_capacity(lo->lo_disk, size);
bd_set_size(bdev, size << 9);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 02/41] block/loop: queue ordered mode should be DRAIN_FLUSH
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo
loop implements FLUSH using fsync but was incorrectly setting its
ordered mode to DRAIN. Change it to DRAIN_FLUSH. In practice, this
doesn't change anything as loop doesn't make use of the block layer
ordered implementation.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
drivers/block/loop.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index f3c636d..c3a4a2e 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -832,7 +832,7 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
lo->lo_queue->unplug_fn = loop_unplug;
if (!(lo_flags & LO_FLAGS_READ_ONLY) && file->f_op->fsync)
- blk_queue_ordered(lo->lo_queue, QUEUE_ORDERED_DRAIN);
+ blk_queue_ordered(lo->lo_queue, QUEUE_ORDERED_DRAIN_FLUSH);
set_capacity(lo->lo_disk, size);
bd_set_size(bdev, size << 9);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* Re: [PATCH 02/41] block/loop: queue ordered mode should be DRAIN_FLUSH
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-12 8:38 ` Tao Ma
2010-09-12 11:41 ` Tejun Heo
-1 siblings, 1 reply; 159+ messages in thread
From: Tao Ma @ 2010-09-12 8:38 UTC (permalink / raw)
To: Tejun Heo; +Cc: linux-kernel, linux-fsdevel
Hi Tejun,
Just a small qs about this patch.
On 09/03/2010 06:29 PM, Tejun Heo wrote:
> loop implements FLUSH using fsync but was incorrectly setting its
> ordered mode to DRAIN. Change it to DRAIN_FLUSH. In practice, this
> doesn't change anything as loop doesn't make use of the block layer
> ordered implementation.
According to Documentation/block/barrier.txt,
QUEUE_ORDERED_DRAIN
Requests are ordered by draining the request queue and cache
flushing isn't needed.
Sequence: drain => barrier
QUEUE_ORDERED_DRAIN_FLUSH
Requests are ordered by draining the request queue and both
pre-barrier and post-barrier cache flushings are needed.
Sequence: drain => preflush => barrier => postflush
And for loop device, it call fsync in barrier request. See
do_bio_filebacked in drivers/block/loop.c
bool barrier = !!(bio->bi_rw & REQ_HARDBARRIER);
struct file *file = lo->lo_backing_file;
if (barrier) {
if (unlikely(!file->f_op->fsync)) {
ret = -EOPNOTSUPP;
goto out;
}
ret = vfs_fsync(file, 0);
if (unlikely(ret)) {
ret = -EIO;
goto out;
}
}
So actually the sync is done in barrier and no extra flush is needed?
Or Do I misread the rules in barrier.txt?
Regards,
Tao
>
> Signed-off-by: Tejun Heo<tj@kernel.org>
> ---
> drivers/block/loop.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/block/loop.c b/drivers/block/loop.c
> index f3c636d..c3a4a2e 100644
> --- a/drivers/block/loop.c
> +++ b/drivers/block/loop.c
> @@ -832,7 +832,7 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
> lo->lo_queue->unplug_fn = loop_unplug;
>
> if (!(lo_flags& LO_FLAGS_READ_ONLY)&& file->f_op->fsync)
> - blk_queue_ordered(lo->lo_queue, QUEUE_ORDERED_DRAIN);
> + blk_queue_ordered(lo->lo_queue, QUEUE_ORDERED_DRAIN_FLUSH);
>
> set_capacity(lo->lo_disk, size);
> bd_set_size(bdev, size<< 9);
^ permalink raw reply [flat|nested] 159+ messages in thread* Re: [PATCH 02/41] block/loop: queue ordered mode should be DRAIN_FLUSH
2010-09-12 8:38 ` Tao Ma
@ 2010-09-12 11:41 ` Tejun Heo
2010-09-12 11:55 ` Tao Ma
0 siblings, 1 reply; 159+ messages in thread
From: Tejun Heo @ 2010-09-12 11:41 UTC (permalink / raw)
To: Tao Ma; +Cc: linux-kernel, linux-fsdevel
Hello,
On 09/12/2010 10:38 AM, Tao Ma wrote:
> According to Documentation/block/barrier.txt,
> QUEUE_ORDERED_DRAIN
> Requests are ordered by draining the request queue and cache
> flushing isn't needed.
>
> Sequence: drain => barrier
>
> QUEUE_ORDERED_DRAIN_FLUSH
> Requests are ordered by draining the request queue and both
> pre-barrier and post-barrier cache flushings are needed.
>
> Sequence: drain => preflush => barrier => postflush
>
> And for loop device, it call fsync in barrier request. See do_bio_filebacked in drivers/block/loop.c
> bool barrier = !!(bio->bi_rw & REQ_HARDBARRIER);
> struct file *file = lo->lo_backing_file;
>
> if (barrier) {
> if (unlikely(!file->f_op->fsync)) {
> ret = -EOPNOTSUPP;
> goto out;
> }
>
> ret = vfs_fsync(file, 0);
> if (unlikely(ret)) {
> ret = -EIO;
> goto out;
> }
> }
>
> So actually the sync is done in barrier and no extra flush is needed?
> Or Do I misread the rules in barrier.txt?
Hmmm... maybe the doc was a bit confusing. Any device which has
writeback cache should have FLUSH in the queue ordered configuration.
The loop device used vfs_fsync() for cache flushing and didn't support
ordered sequence. As such, it should use draining for request
ordering and suports FLUSH, so the mode to use is DRAIN_FLUSH.
Thanks.
--
tejun
^ permalink raw reply [flat|nested] 159+ messages in thread* Re: [PATCH 02/41] block/loop: queue ordered mode should be DRAIN_FLUSH
2010-09-12 11:41 ` Tejun Heo
@ 2010-09-12 11:55 ` Tao Ma
0 siblings, 0 replies; 159+ messages in thread
From: Tao Ma @ 2010-09-12 11:55 UTC (permalink / raw)
To: Tejun Heo; +Cc: linux-kernel, linux-fsdevel
On 09/12/2010 07:41 PM, Tejun Heo wrote:
> Hello,
>
> On 09/12/2010 10:38 AM, Tao Ma wrote:
>> According to Documentation/block/barrier.txt,
>> QUEUE_ORDERED_DRAIN
>> Requests are ordered by draining the request queue and cache
>> flushing isn't needed.
>>
>> Sequence: drain => barrier
>>
>> QUEUE_ORDERED_DRAIN_FLUSH
>> Requests are ordered by draining the request queue and both
>> pre-barrier and post-barrier cache flushings are needed.
>>
>> Sequence: drain => preflush => barrier => postflush
>>
>> And for loop device, it call fsync in barrier request. See do_bio_filebacked in drivers/block/loop.c
>> bool barrier = !!(bio->bi_rw& REQ_HARDBARRIER);
>> struct file *file = lo->lo_backing_file;
>>
>> if (barrier) {
>> if (unlikely(!file->f_op->fsync)) {
>> ret = -EOPNOTSUPP;
>> goto out;
>> }
>>
>> ret = vfs_fsync(file, 0);
>> if (unlikely(ret)) {
>> ret = -EIO;
>> goto out;
>> }
>> }
>>
>> So actually the sync is done in barrier and no extra flush is needed?
>> Or Do I misread the rules in barrier.txt?
>
> Hmmm... maybe the doc was a bit confusing. Any device which has
> writeback cache should have FLUSH in the queue ordered configuration.
> The loop device used vfs_fsync() for cache flushing and didn't support
> ordered sequence. As such, it should use draining for request
> ordering and suports FLUSH, so the mode to use is DRAIN_FLUSH.
oh, thanks for the explanation.
Regards,
Tao
^ permalink raw reply [flat|nested] 159+ messages in thread
* [PATCH 03/41] block: kill QUEUE_ORDERED_BY_TAG
2010-09-03 10:29 ` Tejun Heo
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel
Cc: Tejun Heo, Christoph Hellwig, Nick Piggin, Jeremy Fitzhardinge,
Chris Wright
Nobody is making meaningful use of ORDERED_BY_TAG now and queue
draining for barrier requests will be removed soon which will render
the advantage of tag ordering moot. Kill ORDERED_BY_TAG. The
following users are affected.
* brd: converted to ORDERED_DRAIN.
* virtio_blk: ORDERED_TAG path was already marked deprecated. Removed.
* xen-blkfront: ORDERED_TAG case dropped.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
---
block/blk-barrier.c | 35 +++++++----------------------------
drivers/block/brd.c | 2 +-
drivers/block/virtio_blk.c | 9 ---------
drivers/block/xen-blkfront.c | 8 +++-----
drivers/scsi/sd.c | 4 +---
include/linux/blkdev.h | 17 +----------------
6 files changed, 13 insertions(+), 62 deletions(-)
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index f0faefc..c807e9c 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -26,10 +26,7 @@ int blk_queue_ordered(struct request_queue *q, unsigned ordered)
if (ordered != QUEUE_ORDERED_NONE &&
ordered != QUEUE_ORDERED_DRAIN &&
ordered != QUEUE_ORDERED_DRAIN_FLUSH &&
- ordered != QUEUE_ORDERED_DRAIN_FUA &&
- ordered != QUEUE_ORDERED_TAG &&
- ordered != QUEUE_ORDERED_TAG_FLUSH &&
- ordered != QUEUE_ORDERED_TAG_FUA) {
+ ordered != QUEUE_ORDERED_DRAIN_FUA) {
printk(KERN_ERR "blk_queue_ordered: bad value %d\n", ordered);
return -EINVAL;
}
@@ -155,21 +152,9 @@ static inline bool start_ordered(struct request_queue *q, struct request **rqp)
* For an empty barrier, there's no actual BAR request, which
* in turn makes POSTFLUSH unnecessary. Mask them off.
*/
- if (!blk_rq_sectors(rq)) {
+ if (!blk_rq_sectors(rq))
q->ordered &= ~(QUEUE_ORDERED_DO_BAR |
QUEUE_ORDERED_DO_POSTFLUSH);
- /*
- * Empty barrier on a write-through device w/ ordered
- * tag has no command to issue and without any command
- * to issue, ordering by tag can't be used. Drain
- * instead.
- */
- if ((q->ordered & QUEUE_ORDERED_BY_TAG) &&
- !(q->ordered & QUEUE_ORDERED_DO_PREFLUSH)) {
- q->ordered &= ~QUEUE_ORDERED_BY_TAG;
- q->ordered |= QUEUE_ORDERED_BY_DRAIN;
- }
- }
/* stash away the original request */
blk_dequeue_request(rq);
@@ -210,7 +195,7 @@ static inline bool start_ordered(struct request_queue *q, struct request **rqp)
} else
skip |= QUEUE_ORDSEQ_PREFLUSH;
- if ((q->ordered & QUEUE_ORDERED_BY_DRAIN) && queue_in_flight(q))
+ if (queue_in_flight(q))
rq = NULL;
else
skip |= QUEUE_ORDSEQ_DRAIN;
@@ -257,16 +242,10 @@ bool blk_do_ordered(struct request_queue *q, struct request **rqp)
rq != &q->pre_flush_rq && rq != &q->post_flush_rq)
return true;
- if (q->ordered & QUEUE_ORDERED_BY_TAG) {
- /* Ordered by tag. Blocking the next barrier is enough. */
- if (is_barrier && rq != &q->bar_rq)
- *rqp = NULL;
- } else {
- /* Ordered by draining. Wait for turn. */
- WARN_ON(blk_ordered_req_seq(rq) < blk_ordered_cur_seq(q));
- if (blk_ordered_req_seq(rq) > blk_ordered_cur_seq(q))
- *rqp = NULL;
- }
+ /* Ordered by draining. Wait for turn. */
+ WARN_ON(blk_ordered_req_seq(rq) < blk_ordered_cur_seq(q));
+ if (blk_ordered_req_seq(rq) > blk_ordered_cur_seq(q))
+ *rqp = NULL;
return true;
}
diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index 1c7f637..47a4127 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -482,7 +482,7 @@ static struct brd_device *brd_alloc(int i)
if (!brd->brd_queue)
goto out_free_dev;
blk_queue_make_request(brd->brd_queue, brd_make_request);
- blk_queue_ordered(brd->brd_queue, QUEUE_ORDERED_TAG);
+ blk_queue_ordered(brd->brd_queue, QUEUE_ORDERED_DRAIN);
blk_queue_max_hw_sectors(brd->brd_queue, 1024);
blk_queue_bounce_limit(brd->brd_queue, BLK_BOUNCE_ANY);
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 2aafafc..7965280 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -395,15 +395,6 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
* to implement write barrier support.
*/
blk_queue_ordered(q, QUEUE_ORDERED_DRAIN_FLUSH);
- } else if (virtio_has_feature(vdev, VIRTIO_BLK_F_BARRIER)) {
- /*
- * If the BARRIER feature is supported the host expects us
- * to order request by tags. This implies there is not
- * volatile write cache on the host, and that the host
- * never re-orders outstanding I/O. This feature is not
- * useful for real life scenarious and deprecated.
- */
- blk_queue_ordered(q, QUEUE_ORDERED_TAG);
} else {
/*
* If the FLUSH feature is not supported we must assume that
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index ab735a6..8341862 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -424,8 +424,7 @@ static int xlvbd_barrier(struct blkfront_info *info)
const char *barrier;
switch (info->feature_barrier) {
- case QUEUE_ORDERED_DRAIN: barrier = "enabled (drain)"; break;
- case QUEUE_ORDERED_TAG: barrier = "enabled (tag)"; break;
+ case QUEUE_ORDERED_DRAIN: barrier = "enabled"; break;
case QUEUE_ORDERED_NONE: barrier = "disabled"; break;
default: return -EINVAL;
}
@@ -1078,8 +1077,7 @@ static void blkfront_connect(struct blkfront_info *info)
* we're dealing with a very old backend which writes
* synchronously; draining will do what needs to get done.
*
- * If there are barriers, then we can do full queued writes
- * with tagged barriers.
+ * If there are barriers, then we use flush.
*
* If barriers are not supported, then there's no much we can
* do, so just set ordering to NONE.
@@ -1087,7 +1085,7 @@ static void blkfront_connect(struct blkfront_info *info)
if (err)
info->feature_barrier = QUEUE_ORDERED_DRAIN;
else if (barrier)
- info->feature_barrier = QUEUE_ORDERED_TAG;
+ info->feature_barrier = QUEUE_ORDERED_DRAIN_FLUSH;
else
info->feature_barrier = QUEUE_ORDERED_NONE;
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 2714bec..cdfc51a 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2151,9 +2151,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
/*
* We now have all cache related info, determine how we deal
- * with ordered requests. Note that as the current SCSI
- * dispatch function can alter request order, we cannot use
- * QUEUE_ORDERED_TAG_* even when ordered tag is supported.
+ * with ordered requests.
*/
if (sdkp->WCE)
ordered = sdkp->DPOFUA
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 015375c..7077bc0 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -470,12 +470,7 @@ enum {
* DRAIN : ordering by draining is enough
* DRAIN_FLUSH : ordering by draining w/ pre and post flushes
* DRAIN_FUA : ordering by draining w/ pre flush and FUA write
- * TAG : ordering by tag is enough
- * TAG_FLUSH : ordering by tag w/ pre and post flushes
- * TAG_FUA : ordering by tag w/ pre flush and FUA write
*/
- QUEUE_ORDERED_BY_DRAIN = 0x01,
- QUEUE_ORDERED_BY_TAG = 0x02,
QUEUE_ORDERED_DO_PREFLUSH = 0x10,
QUEUE_ORDERED_DO_BAR = 0x20,
QUEUE_ORDERED_DO_POSTFLUSH = 0x40,
@@ -483,8 +478,7 @@ enum {
QUEUE_ORDERED_NONE = 0x00,
- QUEUE_ORDERED_DRAIN = QUEUE_ORDERED_BY_DRAIN |
- QUEUE_ORDERED_DO_BAR,
+ QUEUE_ORDERED_DRAIN = QUEUE_ORDERED_DO_BAR,
QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
QUEUE_ORDERED_DO_PREFLUSH |
QUEUE_ORDERED_DO_POSTFLUSH,
@@ -492,15 +486,6 @@ enum {
QUEUE_ORDERED_DO_PREFLUSH |
QUEUE_ORDERED_DO_FUA,
- QUEUE_ORDERED_TAG = QUEUE_ORDERED_BY_TAG |
- QUEUE_ORDERED_DO_BAR,
- QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG |
- QUEUE_ORDERED_DO_PREFLUSH |
- QUEUE_ORDERED_DO_POSTFLUSH,
- QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG |
- QUEUE_ORDERED_DO_PREFLUSH |
- QUEUE_ORDERED_DO_FUA,
-
/*
* Ordered operation sequence
*/
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 03/41] block: kill QUEUE_ORDERED_BY_TAG
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo, Christoph Hellwig, Nick Piggin, Jeremy Fitzhardinge,
Chris Wright
Nobody is making meaningful use of ORDERED_BY_TAG now and queue
draining for barrier requests will be removed soon which will render
the advantage of tag ordering moot. Kill ORDERED_BY_TAG. The
following users are affected.
* brd: converted to ORDERED_DRAIN.
* virtio_blk: ORDERED_TAG path was already marked deprecated. Removed.
* xen-blkfront: ORDERED_TAG case dropped.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
---
block/blk-barrier.c | 35 +++++++----------------------------
drivers/block/brd.c | 2 +-
drivers/block/virtio_blk.c | 9 ---------
drivers/block/xen-blkfront.c | 8 +++-----
drivers/scsi/sd.c | 4 +---
include/linux/blkdev.h | 17 +----------------
6 files changed, 13 insertions(+), 62 deletions(-)
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index f0faefc..c807e9c 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -26,10 +26,7 @@ int blk_queue_ordered(struct request_queue *q, unsigned ordered)
if (ordered != QUEUE_ORDERED_NONE &&
ordered != QUEUE_ORDERED_DRAIN &&
ordered != QUEUE_ORDERED_DRAIN_FLUSH &&
- ordered != QUEUE_ORDERED_DRAIN_FUA &&
- ordered != QUEUE_ORDERED_TAG &&
- ordered != QUEUE_ORDERED_TAG_FLUSH &&
- ordered != QUEUE_ORDERED_TAG_FUA) {
+ ordered != QUEUE_ORDERED_DRAIN_FUA) {
printk(KERN_ERR "blk_queue_ordered: bad value %d\n", ordered);
return -EINVAL;
}
@@ -155,21 +152,9 @@ static inline bool start_ordered(struct request_queue *q, struct request **rqp)
* For an empty barrier, there's no actual BAR request, which
* in turn makes POSTFLUSH unnecessary. Mask them off.
*/
- if (!blk_rq_sectors(rq)) {
+ if (!blk_rq_sectors(rq))
q->ordered &= ~(QUEUE_ORDERED_DO_BAR |
QUEUE_ORDERED_DO_POSTFLUSH);
- /*
- * Empty barrier on a write-through device w/ ordered
- * tag has no command to issue and without any command
- * to issue, ordering by tag can't be used. Drain
- * instead.
- */
- if ((q->ordered & QUEUE_ORDERED_BY_TAG) &&
- !(q->ordered & QUEUE_ORDERED_DO_PREFLUSH)) {
- q->ordered &= ~QUEUE_ORDERED_BY_TAG;
- q->ordered |= QUEUE_ORDERED_BY_DRAIN;
- }
- }
/* stash away the original request */
blk_dequeue_request(rq);
@@ -210,7 +195,7 @@ static inline bool start_ordered(struct request_queue *q, struct request **rqp)
} else
skip |= QUEUE_ORDSEQ_PREFLUSH;
- if ((q->ordered & QUEUE_ORDERED_BY_DRAIN) && queue_in_flight(q))
+ if (queue_in_flight(q))
rq = NULL;
else
skip |= QUEUE_ORDSEQ_DRAIN;
@@ -257,16 +242,10 @@ bool blk_do_ordered(struct request_queue *q, struct request **rqp)
rq != &q->pre_flush_rq && rq != &q->post_flush_rq)
return true;
- if (q->ordered & QUEUE_ORDERED_BY_TAG) {
- /* Ordered by tag. Blocking the next barrier is enough. */
- if (is_barrier && rq != &q->bar_rq)
- *rqp = NULL;
- } else {
- /* Ordered by draining. Wait for turn. */
- WARN_ON(blk_ordered_req_seq(rq) < blk_ordered_cur_seq(q));
- if (blk_ordered_req_seq(rq) > blk_ordered_cur_seq(q))
- *rqp = NULL;
- }
+ /* Ordered by draining. Wait for turn. */
+ WARN_ON(blk_ordered_req_seq(rq) < blk_ordered_cur_seq(q));
+ if (blk_ordered_req_seq(rq) > blk_ordered_cur_seq(q))
+ *rqp = NULL;
return true;
}
diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index 1c7f637..47a4127 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -482,7 +482,7 @@ static struct brd_device *brd_alloc(int i)
if (!brd->brd_queue)
goto out_free_dev;
blk_queue_make_request(brd->brd_queue, brd_make_request);
- blk_queue_ordered(brd->brd_queue, QUEUE_ORDERED_TAG);
+ blk_queue_ordered(brd->brd_queue, QUEUE_ORDERED_DRAIN);
blk_queue_max_hw_sectors(brd->brd_queue, 1024);
blk_queue_bounce_limit(brd->brd_queue, BLK_BOUNCE_ANY);
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 2aafafc..7965280 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -395,15 +395,6 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
* to implement write barrier support.
*/
blk_queue_ordered(q, QUEUE_ORDERED_DRAIN_FLUSH);
- } else if (virtio_has_feature(vdev, VIRTIO_BLK_F_BARRIER)) {
- /*
- * If the BARRIER feature is supported the host expects us
- * to order request by tags. This implies there is not
- * volatile write cache on the host, and that the host
- * never re-orders outstanding I/O. This feature is not
- * useful for real life scenarious and deprecated.
- */
- blk_queue_ordered(q, QUEUE_ORDERED_TAG);
} else {
/*
* If the FLUSH feature is not supported we must assume that
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index ab735a6..8341862 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -424,8 +424,7 @@ static int xlvbd_barrier(struct blkfront_info *info)
const char *barrier;
switch (info->feature_barrier) {
- case QUEUE_ORDERED_DRAIN: barrier = "enabled (drain)"; break;
- case QUEUE_ORDERED_TAG: barrier = "enabled (tag)"; break;
+ case QUEUE_ORDERED_DRAIN: barrier = "enabled"; break;
case QUEUE_ORDERED_NONE: barrier = "disabled"; break;
default: return -EINVAL;
}
@@ -1078,8 +1077,7 @@ static void blkfront_connect(struct blkfront_info *info)
* we're dealing with a very old backend which writes
* synchronously; draining will do what needs to get done.
*
- * If there are barriers, then we can do full queued writes
- * with tagged barriers.
+ * If there are barriers, then we use flush.
*
* If barriers are not supported, then there's no much we can
* do, so just set ordering to NONE.
@@ -1087,7 +1085,7 @@ static void blkfront_connect(struct blkfront_info *info)
if (err)
info->feature_barrier = QUEUE_ORDERED_DRAIN;
else if (barrier)
- info->feature_barrier = QUEUE_ORDERED_TAG;
+ info->feature_barrier = QUEUE_ORDERED_DRAIN_FLUSH;
else
info->feature_barrier = QUEUE_ORDERED_NONE;
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 2714bec..cdfc51a 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2151,9 +2151,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
/*
* We now have all cache related info, determine how we deal
- * with ordered requests. Note that as the current SCSI
- * dispatch function can alter request order, we cannot use
- * QUEUE_ORDERED_TAG_* even when ordered tag is supported.
+ * with ordered requests.
*/
if (sdkp->WCE)
ordered = sdkp->DPOFUA
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 015375c..7077bc0 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -470,12 +470,7 @@ enum {
* DRAIN : ordering by draining is enough
* DRAIN_FLUSH : ordering by draining w/ pre and post flushes
* DRAIN_FUA : ordering by draining w/ pre flush and FUA write
- * TAG : ordering by tag is enough
- * TAG_FLUSH : ordering by tag w/ pre and post flushes
- * TAG_FUA : ordering by tag w/ pre flush and FUA write
*/
- QUEUE_ORDERED_BY_DRAIN = 0x01,
- QUEUE_ORDERED_BY_TAG = 0x02,
QUEUE_ORDERED_DO_PREFLUSH = 0x10,
QUEUE_ORDERED_DO_BAR = 0x20,
QUEUE_ORDERED_DO_POSTFLUSH = 0x40,
@@ -483,8 +478,7 @@ enum {
QUEUE_ORDERED_NONE = 0x00,
- QUEUE_ORDERED_DRAIN = QUEUE_ORDERED_BY_DRAIN |
- QUEUE_ORDERED_DO_BAR,
+ QUEUE_ORDERED_DRAIN = QUEUE_ORDERED_DO_BAR,
QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
QUEUE_ORDERED_DO_PREFLUSH |
QUEUE_ORDERED_DO_POSTFLUSH,
@@ -492,15 +486,6 @@ enum {
QUEUE_ORDERED_DO_PREFLUSH |
QUEUE_ORDERED_DO_FUA,
- QUEUE_ORDERED_TAG = QUEUE_ORDERED_BY_TAG |
- QUEUE_ORDERED_DO_BAR,
- QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG |
- QUEUE_ORDERED_DO_PREFLUSH |
- QUEUE_ORDERED_DO_POSTFLUSH,
- QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG |
- QUEUE_ORDERED_DO_PREFLUSH |
- QUEUE_ORDERED_DO_FUA,
-
/*
* Ordered operation sequence
*/
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 03/41] block: kill QUEUE_ORDERED_BY_TAG
2010-09-03 10:29 ` Tejun Heo
` (6 preceding siblings ...)
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo, Christoph Hellwig, Nick Piggin, Chris Wright,
Jeremy Fitzhardinge
Nobody is making meaningful use of ORDERED_BY_TAG now and queue
draining for barrier requests will be removed soon which will render
the advantage of tag ordering moot. Kill ORDERED_BY_TAG. The
following users are affected.
* brd: converted to ORDERED_DRAIN.
* virtio_blk: ORDERED_TAG path was already marked deprecated. Removed.
* xen-blkfront: ORDERED_TAG case dropped.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
---
block/blk-barrier.c | 35 +++++++----------------------------
drivers/block/brd.c | 2 +-
drivers/block/virtio_blk.c | 9 ---------
drivers/block/xen-blkfront.c | 8 +++-----
drivers/scsi/sd.c | 4 +---
include/linux/blkdev.h | 17 +----------------
6 files changed, 13 insertions(+), 62 deletions(-)
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index f0faefc..c807e9c 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -26,10 +26,7 @@ int blk_queue_ordered(struct request_queue *q, unsigned ordered)
if (ordered != QUEUE_ORDERED_NONE &&
ordered != QUEUE_ORDERED_DRAIN &&
ordered != QUEUE_ORDERED_DRAIN_FLUSH &&
- ordered != QUEUE_ORDERED_DRAIN_FUA &&
- ordered != QUEUE_ORDERED_TAG &&
- ordered != QUEUE_ORDERED_TAG_FLUSH &&
- ordered != QUEUE_ORDERED_TAG_FUA) {
+ ordered != QUEUE_ORDERED_DRAIN_FUA) {
printk(KERN_ERR "blk_queue_ordered: bad value %d\n", ordered);
return -EINVAL;
}
@@ -155,21 +152,9 @@ static inline bool start_ordered(struct request_queue *q, struct request **rqp)
* For an empty barrier, there's no actual BAR request, which
* in turn makes POSTFLUSH unnecessary. Mask them off.
*/
- if (!blk_rq_sectors(rq)) {
+ if (!blk_rq_sectors(rq))
q->ordered &= ~(QUEUE_ORDERED_DO_BAR |
QUEUE_ORDERED_DO_POSTFLUSH);
- /*
- * Empty barrier on a write-through device w/ ordered
- * tag has no command to issue and without any command
- * to issue, ordering by tag can't be used. Drain
- * instead.
- */
- if ((q->ordered & QUEUE_ORDERED_BY_TAG) &&
- !(q->ordered & QUEUE_ORDERED_DO_PREFLUSH)) {
- q->ordered &= ~QUEUE_ORDERED_BY_TAG;
- q->ordered |= QUEUE_ORDERED_BY_DRAIN;
- }
- }
/* stash away the original request */
blk_dequeue_request(rq);
@@ -210,7 +195,7 @@ static inline bool start_ordered(struct request_queue *q, struct request **rqp)
} else
skip |= QUEUE_ORDSEQ_PREFLUSH;
- if ((q->ordered & QUEUE_ORDERED_BY_DRAIN) && queue_in_flight(q))
+ if (queue_in_flight(q))
rq = NULL;
else
skip |= QUEUE_ORDSEQ_DRAIN;
@@ -257,16 +242,10 @@ bool blk_do_ordered(struct request_queue *q, struct request **rqp)
rq != &q->pre_flush_rq && rq != &q->post_flush_rq)
return true;
- if (q->ordered & QUEUE_ORDERED_BY_TAG) {
- /* Ordered by tag. Blocking the next barrier is enough. */
- if (is_barrier && rq != &q->bar_rq)
- *rqp = NULL;
- } else {
- /* Ordered by draining. Wait for turn. */
- WARN_ON(blk_ordered_req_seq(rq) < blk_ordered_cur_seq(q));
- if (blk_ordered_req_seq(rq) > blk_ordered_cur_seq(q))
- *rqp = NULL;
- }
+ /* Ordered by draining. Wait for turn. */
+ WARN_ON(blk_ordered_req_seq(rq) < blk_ordered_cur_seq(q));
+ if (blk_ordered_req_seq(rq) > blk_ordered_cur_seq(q))
+ *rqp = NULL;
return true;
}
diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index 1c7f637..47a4127 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -482,7 +482,7 @@ static struct brd_device *brd_alloc(int i)
if (!brd->brd_queue)
goto out_free_dev;
blk_queue_make_request(brd->brd_queue, brd_make_request);
- blk_queue_ordered(brd->brd_queue, QUEUE_ORDERED_TAG);
+ blk_queue_ordered(brd->brd_queue, QUEUE_ORDERED_DRAIN);
blk_queue_max_hw_sectors(brd->brd_queue, 1024);
blk_queue_bounce_limit(brd->brd_queue, BLK_BOUNCE_ANY);
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 2aafafc..7965280 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -395,15 +395,6 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
* to implement write barrier support.
*/
blk_queue_ordered(q, QUEUE_ORDERED_DRAIN_FLUSH);
- } else if (virtio_has_feature(vdev, VIRTIO_BLK_F_BARRIER)) {
- /*
- * If the BARRIER feature is supported the host expects us
- * to order request by tags. This implies there is not
- * volatile write cache on the host, and that the host
- * never re-orders outstanding I/O. This feature is not
- * useful for real life scenarious and deprecated.
- */
- blk_queue_ordered(q, QUEUE_ORDERED_TAG);
} else {
/*
* If the FLUSH feature is not supported we must assume that
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index ab735a6..8341862 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -424,8 +424,7 @@ static int xlvbd_barrier(struct blkfront_info *info)
const char *barrier;
switch (info->feature_barrier) {
- case QUEUE_ORDERED_DRAIN: barrier = "enabled (drain)"; break;
- case QUEUE_ORDERED_TAG: barrier = "enabled (tag)"; break;
+ case QUEUE_ORDERED_DRAIN: barrier = "enabled"; break;
case QUEUE_ORDERED_NONE: barrier = "disabled"; break;
default: return -EINVAL;
}
@@ -1078,8 +1077,7 @@ static void blkfront_connect(struct blkfront_info *info)
* we're dealing with a very old backend which writes
* synchronously; draining will do what needs to get done.
*
- * If there are barriers, then we can do full queued writes
- * with tagged barriers.
+ * If there are barriers, then we use flush.
*
* If barriers are not supported, then there's no much we can
* do, so just set ordering to NONE.
@@ -1087,7 +1085,7 @@ static void blkfront_connect(struct blkfront_info *info)
if (err)
info->feature_barrier = QUEUE_ORDERED_DRAIN;
else if (barrier)
- info->feature_barrier = QUEUE_ORDERED_TAG;
+ info->feature_barrier = QUEUE_ORDERED_DRAIN_FLUSH;
else
info->feature_barrier = QUEUE_ORDERED_NONE;
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 2714bec..cdfc51a 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2151,9 +2151,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
/*
* We now have all cache related info, determine how we deal
- * with ordered requests. Note that as the current SCSI
- * dispatch function can alter request order, we cannot use
- * QUEUE_ORDERED_TAG_* even when ordered tag is supported.
+ * with ordered requests.
*/
if (sdkp->WCE)
ordered = sdkp->DPOFUA
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 015375c..7077bc0 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -470,12 +470,7 @@ enum {
* DRAIN : ordering by draining is enough
* DRAIN_FLUSH : ordering by draining w/ pre and post flushes
* DRAIN_FUA : ordering by draining w/ pre flush and FUA write
- * TAG : ordering by tag is enough
- * TAG_FLUSH : ordering by tag w/ pre and post flushes
- * TAG_FUA : ordering by tag w/ pre flush and FUA write
*/
- QUEUE_ORDERED_BY_DRAIN = 0x01,
- QUEUE_ORDERED_BY_TAG = 0x02,
QUEUE_ORDERED_DO_PREFLUSH = 0x10,
QUEUE_ORDERED_DO_BAR = 0x20,
QUEUE_ORDERED_DO_POSTFLUSH = 0x40,
@@ -483,8 +478,7 @@ enum {
QUEUE_ORDERED_NONE = 0x00,
- QUEUE_ORDERED_DRAIN = QUEUE_ORDERED_BY_DRAIN |
- QUEUE_ORDERED_DO_BAR,
+ QUEUE_ORDERED_DRAIN = QUEUE_ORDERED_DO_BAR,
QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
QUEUE_ORDERED_DO_PREFLUSH |
QUEUE_ORDERED_DO_POSTFLUSH,
@@ -492,15 +486,6 @@ enum {
QUEUE_ORDERED_DO_PREFLUSH |
QUEUE_ORDERED_DO_FUA,
- QUEUE_ORDERED_TAG = QUEUE_ORDERED_BY_TAG |
- QUEUE_ORDERED_DO_BAR,
- QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG |
- QUEUE_ORDERED_DO_PREFLUSH |
- QUEUE_ORDERED_DO_POSTFLUSH,
- QUEUE_ORDERED_TAG_FUA = QUEUE_ORDERED_TAG |
- QUEUE_ORDERED_DO_PREFLUSH |
- QUEUE_ORDERED_DO_FUA,
-
/*
* Ordered operation sequence
*/
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 04/41] block: deprecate barrier and replace blk_queue_ordered() with blk_queue_flush()
2010-09-03 10:29 ` Tejun Heo
` (7 preceding siblings ...)
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Chris Wright, FUJITA Tomonori, Nick Piggin, Christoph Hellwig,
Geert Uytterhoeven, Pierre Ossman, Stefan Weinhuber, Tejun Heo,
David S. Miller, Alasdair G Kergon, Jeremy Fitzhardinge
Barrier is deemed too heavy and will soon be replaced by FLUSH/FUA
requests. Deprecate barrier. All REQ_HARDBARRIERs are failed with
-EOPNOTSUPP and blk_queue_ordered() is replaced with simpler
blk_queue_flush().
blk_queue_flush() takes combinations of REQ_FLUSH and FUA. If a
device has write cache and can flush it, it should set REQ_FLUSH. If
the device can handle FUA writes, it should also set REQ_FUA.
All blk_queue_ordered() users are converted.
* ORDERED_DRAIN is mapped to 0 which is the default value.
* ORDERED_DRAIN_FLUSH is mapped to REQ_FLUSH.
* ORDERED_DRAIN_FLUSH_FUA is mapped to REQ_FLUSH | REQ_FUA.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Boaz Harrosh <bharrosh@panasas.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Alasdair G Kergon <agk@redhat.com>
Cc: Pierre Ossman <drzeus@drzeus.cx>
Cc: Stefan Weinhuber <wein@de.ibm.com>
---
block/blk-barrier.c | 29 ----------------------------
block/blk-core.c | 6 +++-
block/blk-settings.c | 20 +++++++++++++++++++
drivers/block/brd.c | 1 -
drivers/block/loop.c | 2 +-
drivers/block/osdblk.c | 2 +-
drivers/block/ps3disk.c | 2 +-
drivers/block/virtio_blk.c | 25 ++++++++---------------
drivers/block/xen-blkfront.c | 43 +++++++++++------------------------------
drivers/ide/ide-disk.c | 13 +++++------
drivers/md/dm.c | 2 +-
drivers/mmc/card/queue.c | 1 -
drivers/s390/block/dasd.c | 1 -
drivers/scsi/sd.c | 16 +++++++-------
include/linux/blkdev.h | 6 +++-
15 files changed, 67 insertions(+), 102 deletions(-)
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index c807e9c..ed0aba5 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -9,35 +9,6 @@
#include "blk.h"
-/**
- * blk_queue_ordered - does this queue support ordered writes
- * @q: the request queue
- * @ordered: one of QUEUE_ORDERED_*
- *
- * Description:
- * For journalled file systems, doing ordered writes on a commit
- * block instead of explicitly doing wait_on_buffer (which is bad
- * for performance) can be a big win. Block drivers supporting this
- * feature should call this function and indicate so.
- *
- **/
-int blk_queue_ordered(struct request_queue *q, unsigned ordered)
-{
- if (ordered != QUEUE_ORDERED_NONE &&
- ordered != QUEUE_ORDERED_DRAIN &&
- ordered != QUEUE_ORDERED_DRAIN_FLUSH &&
- ordered != QUEUE_ORDERED_DRAIN_FUA) {
- printk(KERN_ERR "blk_queue_ordered: bad value %d\n", ordered);
- return -EINVAL;
- }
-
- q->ordered = ordered;
- q->next_ordered = ordered;
-
- return 0;
-}
-EXPORT_SYMBOL(blk_queue_ordered);
-
/*
* Cache flushing for ordered writes handling
*/
diff --git a/block/blk-core.c b/block/blk-core.c
index ee1a1e7..f063541 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1203,11 +1203,13 @@ static int __make_request(struct request_queue *q, struct bio *bio)
const unsigned int ff = bio->bi_rw & REQ_FAILFAST_MASK;
int rw_flags;
- if ((bio->bi_rw & REQ_HARDBARRIER) &&
- (q->next_ordered == QUEUE_ORDERED_NONE)) {
+ /* REQ_HARDBARRIER is no more */
+ if (WARN_ONCE(bio->bi_rw & REQ_HARDBARRIER,
+ "block: HARDBARRIER is deprecated, use FLUSH/FUA instead\n")) {
bio_endio(bio, -EOPNOTSUPP);
return 0;
}
+
/*
* low level driver can indicate that it wants pages above a
* certain limit bounced to low memory (ie for highmem, or even
diff --git a/block/blk-settings.c b/block/blk-settings.c
index a234f4b..9b18afc 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -794,6 +794,26 @@ void blk_queue_update_dma_alignment(struct request_queue *q, int mask)
}
EXPORT_SYMBOL(blk_queue_update_dma_alignment);
+/**
+ * blk_queue_flush - configure queue's cache flush capability
+ * @q: the request queue for the device
+ * @flush: 0, REQ_FLUSH or REQ_FLUSH | REQ_FUA
+ *
+ * Tell block layer cache flush capability of @q. If it supports
+ * flushing, REQ_FLUSH should be set. If it supports bypassing
+ * write cache for individual writes, REQ_FUA should be set.
+ */
+void blk_queue_flush(struct request_queue *q, unsigned int flush)
+{
+ WARN_ON_ONCE(flush & ~(REQ_FLUSH | REQ_FUA));
+
+ if (WARN_ON_ONCE(!(flush & REQ_FLUSH) && (flush & REQ_FUA)))
+ flush &= ~REQ_FUA;
+
+ q->flush_flags = flush & (REQ_FLUSH | REQ_FUA);
+}
+EXPORT_SYMBOL_GPL(blk_queue_flush);
+
static int __init blk_settings_init(void)
{
blk_max_low_pfn = max_low_pfn - 1;
diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index 47a4127..fa33f97 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -482,7 +482,6 @@ static struct brd_device *brd_alloc(int i)
if (!brd->brd_queue)
goto out_free_dev;
blk_queue_make_request(brd->brd_queue, brd_make_request);
- blk_queue_ordered(brd->brd_queue, QUEUE_ORDERED_DRAIN);
blk_queue_max_hw_sectors(brd->brd_queue, 1024);
blk_queue_bounce_limit(brd->brd_queue, BLK_BOUNCE_ANY);
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index c3a4a2e..953d1e1 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -832,7 +832,7 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
lo->lo_queue->unplug_fn = loop_unplug;
if (!(lo_flags & LO_FLAGS_READ_ONLY) && file->f_op->fsync)
- blk_queue_ordered(lo->lo_queue, QUEUE_ORDERED_DRAIN_FLUSH);
+ blk_queue_flush(lo->lo_queue, REQ_FLUSH);
set_capacity(lo->lo_disk, size);
bd_set_size(bdev, size << 9);
diff --git a/drivers/block/osdblk.c b/drivers/block/osdblk.c
index 2284b4f..72d6246 100644
--- a/drivers/block/osdblk.c
+++ b/drivers/block/osdblk.c
@@ -439,7 +439,7 @@ static int osdblk_init_disk(struct osdblk_device *osdev)
blk_queue_stack_limits(q, osd_request_queue(osdev->osd));
blk_queue_prep_rq(q, blk_queue_start_tag);
- blk_queue_ordered(q, QUEUE_ORDERED_DRAIN_FLUSH);
+ blk_queue_flush(q, REQ_FLUSH);
disk->queue = q;
diff --git a/drivers/block/ps3disk.c b/drivers/block/ps3disk.c
index e9da874..4911f9e 100644
--- a/drivers/block/ps3disk.c
+++ b/drivers/block/ps3disk.c
@@ -468,7 +468,7 @@ static int __devinit ps3disk_probe(struct ps3_system_bus_device *_dev)
blk_queue_dma_alignment(queue, dev->blk_size-1);
blk_queue_logical_block_size(queue, dev->blk_size);
- blk_queue_ordered(queue, QUEUE_ORDERED_DRAIN_FLUSH);
+ blk_queue_flush(queue, REQ_FLUSH);
blk_queue_max_segments(queue, -1);
blk_queue_max_segment_size(queue, dev->bounce_size);
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 7965280..d10b635 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -388,22 +388,15 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
vblk->disk->driverfs_dev = &vdev->dev;
index++;
- if (virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH)) {
- /*
- * If the FLUSH feature is supported we do have support for
- * flushing a volatile write cache on the host. Use that
- * to implement write barrier support.
- */
- blk_queue_ordered(q, QUEUE_ORDERED_DRAIN_FLUSH);
- } else {
- /*
- * If the FLUSH feature is not supported we must assume that
- * the host does not perform any kind of volatile write
- * caching. We still need to drain the queue to provider
- * proper barrier semantics.
- */
- blk_queue_ordered(q, QUEUE_ORDERED_DRAIN);
- }
+ /*
+ * If the FLUSH feature is supported we do have support for
+ * flushing a volatile write cache on the host. Use that to
+ * implement write barrier support; otherwise, we must assume
+ * that the host does not perform any kind of volatile write
+ * caching.
+ */
+ if (virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH))
+ blk_queue_flush(q, REQ_FLUSH);
/* If disk is read-only in the host, the guest should obey */
if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 8341862..f2ffc46 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -95,7 +95,7 @@ struct blkfront_info
struct gnttab_free_callback callback;
struct blk_shadow shadow[BLK_RING_SIZE];
unsigned long shadow_free;
- int feature_barrier;
+ unsigned int feature_flush;
int is_ready;
};
@@ -418,25 +418,12 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size)
}
-static int xlvbd_barrier(struct blkfront_info *info)
+static void xlvbd_flush(struct blkfront_info *info)
{
- int err;
- const char *barrier;
-
- switch (info->feature_barrier) {
- case QUEUE_ORDERED_DRAIN: barrier = "enabled"; break;
- case QUEUE_ORDERED_NONE: barrier = "disabled"; break;
- default: return -EINVAL;
- }
-
- err = blk_queue_ordered(info->rq, info->feature_barrier);
-
- if (err)
- return err;
-
+ blk_queue_flush(info->rq, info->feature_flush);
printk(KERN_INFO "blkfront: %s: barriers %s\n",
- info->gd->disk_name, barrier);
- return 0;
+ info->gd->disk_name,
+ info->feature_flush ? "enabled" : "disabled");
}
@@ -515,7 +502,7 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity,
info->rq = gd->queue;
info->gd = gd;
- xlvbd_barrier(info);
+ xlvbd_flush(info);
if (vdisk_info & VDISK_READONLY)
set_disk_ro(gd, 1);
@@ -661,8 +648,8 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
printk(KERN_WARNING "blkfront: %s: write barrier op failed\n",
info->gd->disk_name);
error = -EOPNOTSUPP;
- info->feature_barrier = QUEUE_ORDERED_NONE;
- xlvbd_barrier(info);
+ info->feature_flush = 0;
+ xlvbd_flush(info);
}
/* fall through */
case BLKIF_OP_READ:
@@ -1075,19 +1062,13 @@ static void blkfront_connect(struct blkfront_info *info)
/*
* If there's no "feature-barrier" defined, then it means
* we're dealing with a very old backend which writes
- * synchronously; draining will do what needs to get done.
+ * synchronously; nothing to do.
*
* If there are barriers, then we use flush.
- *
- * If barriers are not supported, then there's no much we can
- * do, so just set ordering to NONE.
*/
- if (err)
- info->feature_barrier = QUEUE_ORDERED_DRAIN;
- else if (barrier)
- info->feature_barrier = QUEUE_ORDERED_DRAIN_FLUSH;
- else
- info->feature_barrier = QUEUE_ORDERED_NONE;
+ info->feature_flush = 0;
+ if (!err && barrier)
+ info->feature_flush = REQ_FLUSH;
err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size);
if (err) {
diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c
index 7433e07..7c5b01c 100644
--- a/drivers/ide/ide-disk.c
+++ b/drivers/ide/ide-disk.c
@@ -516,10 +516,10 @@ static int ide_do_setfeature(ide_drive_t *drive, u8 feature, u8 nsect)
return ide_no_data_taskfile(drive, &cmd);
}
-static void update_ordered(ide_drive_t *drive)
+static void update_flush(ide_drive_t *drive)
{
u16 *id = drive->id;
- unsigned ordered = QUEUE_ORDERED_NONE;
+ unsigned flush = 0;
if (drive->dev_flags & IDE_DFLAG_WCACHE) {
unsigned long long capacity;
@@ -543,13 +543,12 @@ static void update_ordered(ide_drive_t *drive)
drive->name, barrier ? "" : "not ");
if (barrier) {
- ordered = QUEUE_ORDERED_DRAIN_FLUSH;
+ flush = REQ_FLUSH;
blk_queue_prep_rq(drive->queue, idedisk_prep_fn);
}
- } else
- ordered = QUEUE_ORDERED_DRAIN;
+ }
- blk_queue_ordered(drive->queue, ordered);
+ blk_queue_flush(drive->queue, flush);
}
ide_devset_get_flag(wcache, IDE_DFLAG_WCACHE);
@@ -572,7 +571,7 @@ static int set_wcache(ide_drive_t *drive, int arg)
}
}
- update_ordered(drive);
+ update_flush(drive);
return err;
}
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index ac384b2..b1d92be 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2245,7 +2245,7 @@ static int dm_init_request_based_queue(struct mapped_device *md)
blk_queue_softirq_done(md->queue, dm_softirq_done);
blk_queue_prep_rq(md->queue, dm_prep_fn);
blk_queue_lld_busy(md->queue, dm_lld_busy);
- blk_queue_ordered(md->queue, QUEUE_ORDERED_DRAIN_FLUSH);
+ blk_queue_flush(md->queue, REQ_FLUSH);
elv_register_queue(md->queue);
diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index e876678..9c0b42b 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -128,7 +128,6 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock
mq->req = NULL;
blk_queue_prep_rq(mq->queue, mmc_prep_request);
- blk_queue_ordered(mq->queue, QUEUE_ORDERED_DRAIN);
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue);
if (mmc_can_erase(card)) {
queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mq->queue);
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 8373ca0..9b106d8 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -2197,7 +2197,6 @@ static void dasd_setup_queue(struct dasd_block *block)
*/
blk_queue_max_segment_size(block->request_queue, PAGE_SIZE);
blk_queue_segment_boundary(block->request_queue, PAGE_SIZE - 1);
- blk_queue_ordered(block->request_queue, QUEUE_ORDERED_DRAIN);
}
/*
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index cdfc51a..63bd01a 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2109,7 +2109,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
struct scsi_disk *sdkp = scsi_disk(disk);
struct scsi_device *sdp = sdkp->device;
unsigned char *buffer;
- unsigned ordered;
+ unsigned flush = 0;
SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp,
"sd_revalidate_disk\n"));
@@ -2151,15 +2151,15 @@ static int sd_revalidate_disk(struct gendisk *disk)
/*
* We now have all cache related info, determine how we deal
- * with ordered requests.
+ * with flush requests.
*/
- if (sdkp->WCE)
- ordered = sdkp->DPOFUA
- ? QUEUE_ORDERED_DRAIN_FUA : QUEUE_ORDERED_DRAIN_FLUSH;
- else
- ordered = QUEUE_ORDERED_DRAIN;
+ if (sdkp->WCE) {
+ flush |= REQ_FLUSH;
+ if (sdkp->DPOFUA)
+ flush |= REQ_FUA;
+ }
- blk_queue_ordered(sdkp->disk->queue, ordered);
+ blk_queue_flush(sdkp->disk->queue, flush);
set_capacity(disk, sdkp->capacity);
kfree(buffer);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 7077bc0..e97911d 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -355,8 +355,10 @@ struct request_queue
struct blk_trace *blk_trace;
#endif
/*
- * reserved for flush operations
+ * for flush operations
*/
+ unsigned int flush_flags;
+
unsigned int ordered, next_ordered, ordseq;
int orderr, ordcolor;
struct request pre_flush_rq, bar_rq, post_flush_rq;
@@ -865,8 +867,8 @@ extern void blk_queue_update_dma_alignment(struct request_queue *, int);
extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
+extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
-extern int blk_queue_ordered(struct request_queue *, unsigned);
extern bool blk_do_ordered(struct request_queue *, struct request **);
extern unsigned blk_ordered_cur_seq(struct request_queue *);
extern unsigned blk_ordered_req_seq(struct request *);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 04/41] block: deprecate barrier and replace blk_queue_ordered() with blk_queue_flush()
2010-09-03 10:29 ` Tejun Heo
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel
Cc: Tejun Heo, Christoph Hellwig, Nick Piggin, Jeremy Fitzhardinge,
Chris Wright, FUJITA Tomonori, Geert Uytterhoeven,
David S. Miller, Alasdair G Kergon, Pierre Ossman,
Stefan Weinhuber
Barrier is deemed too heavy and will soon be replaced by FLUSH/FUA
requests. Deprecate barrier. All REQ_HARDBARRIERs are failed with
-EOPNOTSUPP and blk_queue_ordered() is replaced with simpler
blk_queue_flush().
blk_queue_flush() takes combinations of REQ_FLUSH and FUA. If a
device has write cache and can flush it, it should set REQ_FLUSH. If
the device can handle FUA writes, it should also set REQ_FUA.
All blk_queue_ordered() users are converted.
* ORDERED_DRAIN is mapped to 0 which is the default value.
* ORDERED_DRAIN_FLUSH is mapped to REQ_FLUSH.
* ORDERED_DRAIN_FLUSH_FUA is mapped to REQ_FLUSH | REQ_FUA.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Boaz Harrosh <bharrosh@panasas.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Alasdair G Kergon <agk@redhat.com>
Cc: Pierre Ossman <drzeus@drzeus.cx>
Cc: Stefan Weinhuber <wein@de.ibm.com>
---
block/blk-barrier.c | 29 ----------------------------
block/blk-core.c | 6 +++-
block/blk-settings.c | 20 +++++++++++++++++++
drivers/block/brd.c | 1 -
drivers/block/loop.c | 2 +-
drivers/block/osdblk.c | 2 +-
drivers/block/ps3disk.c | 2 +-
drivers/block/virtio_blk.c | 25 ++++++++---------------
drivers/block/xen-blkfront.c | 43 +++++++++++------------------------------
drivers/ide/ide-disk.c | 13 +++++------
drivers/md/dm.c | 2 +-
drivers/mmc/card/queue.c | 1 -
drivers/s390/block/dasd.c | 1 -
drivers/scsi/sd.c | 16 +++++++-------
include/linux/blkdev.h | 6 +++-
15 files changed, 67 insertions(+), 102 deletions(-)
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index c807e9c..ed0aba5 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -9,35 +9,6 @@
#include "blk.h"
-/**
- * blk_queue_ordered - does this queue support ordered writes
- * @q: the request queue
- * @ordered: one of QUEUE_ORDERED_*
- *
- * Description:
- * For journalled file systems, doing ordered writes on a commit
- * block instead of explicitly doing wait_on_buffer (which is bad
- * for performance) can be a big win. Block drivers supporting this
- * feature should call this function and indicate so.
- *
- **/
-int blk_queue_ordered(struct request_queue *q, unsigned ordered)
-{
- if (ordered != QUEUE_ORDERED_NONE &&
- ordered != QUEUE_ORDERED_DRAIN &&
- ordered != QUEUE_ORDERED_DRAIN_FLUSH &&
- ordered != QUEUE_ORDERED_DRAIN_FUA) {
- printk(KERN_ERR "blk_queue_ordered: bad value %d\n", ordered);
- return -EINVAL;
- }
-
- q->ordered = ordered;
- q->next_ordered = ordered;
-
- return 0;
-}
-EXPORT_SYMBOL(blk_queue_ordered);
-
/*
* Cache flushing for ordered writes handling
*/
diff --git a/block/blk-core.c b/block/blk-core.c
index ee1a1e7..f063541 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1203,11 +1203,13 @@ static int __make_request(struct request_queue *q, struct bio *bio)
const unsigned int ff = bio->bi_rw & REQ_FAILFAST_MASK;
int rw_flags;
- if ((bio->bi_rw & REQ_HARDBARRIER) &&
- (q->next_ordered == QUEUE_ORDERED_NONE)) {
+ /* REQ_HARDBARRIER is no more */
+ if (WARN_ONCE(bio->bi_rw & REQ_HARDBARRIER,
+ "block: HARDBARRIER is deprecated, use FLUSH/FUA instead\n")) {
bio_endio(bio, -EOPNOTSUPP);
return 0;
}
+
/*
* low level driver can indicate that it wants pages above a
* certain limit bounced to low memory (ie for highmem, or even
diff --git a/block/blk-settings.c b/block/blk-settings.c
index a234f4b..9b18afc 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -794,6 +794,26 @@ void blk_queue_update_dma_alignment(struct request_queue *q, int mask)
}
EXPORT_SYMBOL(blk_queue_update_dma_alignment);
+/**
+ * blk_queue_flush - configure queue's cache flush capability
+ * @q: the request queue for the device
+ * @flush: 0, REQ_FLUSH or REQ_FLUSH | REQ_FUA
+ *
+ * Tell block layer cache flush capability of @q. If it supports
+ * flushing, REQ_FLUSH should be set. If it supports bypassing
+ * write cache for individual writes, REQ_FUA should be set.
+ */
+void blk_queue_flush(struct request_queue *q, unsigned int flush)
+{
+ WARN_ON_ONCE(flush & ~(REQ_FLUSH | REQ_FUA));
+
+ if (WARN_ON_ONCE(!(flush & REQ_FLUSH) && (flush & REQ_FUA)))
+ flush &= ~REQ_FUA;
+
+ q->flush_flags = flush & (REQ_FLUSH | REQ_FUA);
+}
+EXPORT_SYMBOL_GPL(blk_queue_flush);
+
static int __init blk_settings_init(void)
{
blk_max_low_pfn = max_low_pfn - 1;
diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index 47a4127..fa33f97 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -482,7 +482,6 @@ static struct brd_device *brd_alloc(int i)
if (!brd->brd_queue)
goto out_free_dev;
blk_queue_make_request(brd->brd_queue, brd_make_request);
- blk_queue_ordered(brd->brd_queue, QUEUE_ORDERED_DRAIN);
blk_queue_max_hw_sectors(brd->brd_queue, 1024);
blk_queue_bounce_limit(brd->brd_queue, BLK_BOUNCE_ANY);
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index c3a4a2e..953d1e1 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -832,7 +832,7 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
lo->lo_queue->unplug_fn = loop_unplug;
if (!(lo_flags & LO_FLAGS_READ_ONLY) && file->f_op->fsync)
- blk_queue_ordered(lo->lo_queue, QUEUE_ORDERED_DRAIN_FLUSH);
+ blk_queue_flush(lo->lo_queue, REQ_FLUSH);
set_capacity(lo->lo_disk, size);
bd_set_size(bdev, size << 9);
diff --git a/drivers/block/osdblk.c b/drivers/block/osdblk.c
index 2284b4f..72d6246 100644
--- a/drivers/block/osdblk.c
+++ b/drivers/block/osdblk.c
@@ -439,7 +439,7 @@ static int osdblk_init_disk(struct osdblk_device *osdev)
blk_queue_stack_limits(q, osd_request_queue(osdev->osd));
blk_queue_prep_rq(q, blk_queue_start_tag);
- blk_queue_ordered(q, QUEUE_ORDERED_DRAIN_FLUSH);
+ blk_queue_flush(q, REQ_FLUSH);
disk->queue = q;
diff --git a/drivers/block/ps3disk.c b/drivers/block/ps3disk.c
index e9da874..4911f9e 100644
--- a/drivers/block/ps3disk.c
+++ b/drivers/block/ps3disk.c
@@ -468,7 +468,7 @@ static int __devinit ps3disk_probe(struct ps3_system_bus_device *_dev)
blk_queue_dma_alignment(queue, dev->blk_size-1);
blk_queue_logical_block_size(queue, dev->blk_size);
- blk_queue_ordered(queue, QUEUE_ORDERED_DRAIN_FLUSH);
+ blk_queue_flush(queue, REQ_FLUSH);
blk_queue_max_segments(queue, -1);
blk_queue_max_segment_size(queue, dev->bounce_size);
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 7965280..d10b635 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -388,22 +388,15 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
vblk->disk->driverfs_dev = &vdev->dev;
index++;
- if (virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH)) {
- /*
- * If the FLUSH feature is supported we do have support for
- * flushing a volatile write cache on the host. Use that
- * to implement write barrier support.
- */
- blk_queue_ordered(q, QUEUE_ORDERED_DRAIN_FLUSH);
- } else {
- /*
- * If the FLUSH feature is not supported we must assume that
- * the host does not perform any kind of volatile write
- * caching. We still need to drain the queue to provider
- * proper barrier semantics.
- */
- blk_queue_ordered(q, QUEUE_ORDERED_DRAIN);
- }
+ /*
+ * If the FLUSH feature is supported we do have support for
+ * flushing a volatile write cache on the host. Use that to
+ * implement write barrier support; otherwise, we must assume
+ * that the host does not perform any kind of volatile write
+ * caching.
+ */
+ if (virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH))
+ blk_queue_flush(q, REQ_FLUSH);
/* If disk is read-only in the host, the guest should obey */
if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 8341862..f2ffc46 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -95,7 +95,7 @@ struct blkfront_info
struct gnttab_free_callback callback;
struct blk_shadow shadow[BLK_RING_SIZE];
unsigned long shadow_free;
- int feature_barrier;
+ unsigned int feature_flush;
int is_ready;
};
@@ -418,25 +418,12 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size)
}
-static int xlvbd_barrier(struct blkfront_info *info)
+static void xlvbd_flush(struct blkfront_info *info)
{
- int err;
- const char *barrier;
-
- switch (info->feature_barrier) {
- case QUEUE_ORDERED_DRAIN: barrier = "enabled"; break;
- case QUEUE_ORDERED_NONE: barrier = "disabled"; break;
- default: return -EINVAL;
- }
-
- err = blk_queue_ordered(info->rq, info->feature_barrier);
-
- if (err)
- return err;
-
+ blk_queue_flush(info->rq, info->feature_flush);
printk(KERN_INFO "blkfront: %s: barriers %s\n",
- info->gd->disk_name, barrier);
- return 0;
+ info->gd->disk_name,
+ info->feature_flush ? "enabled" : "disabled");
}
@@ -515,7 +502,7 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity,
info->rq = gd->queue;
info->gd = gd;
- xlvbd_barrier(info);
+ xlvbd_flush(info);
if (vdisk_info & VDISK_READONLY)
set_disk_ro(gd, 1);
@@ -661,8 +648,8 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
printk(KERN_WARNING "blkfront: %s: write barrier op failed\n",
info->gd->disk_name);
error = -EOPNOTSUPP;
- info->feature_barrier = QUEUE_ORDERED_NONE;
- xlvbd_barrier(info);
+ info->feature_flush = 0;
+ xlvbd_flush(info);
}
/* fall through */
case BLKIF_OP_READ:
@@ -1075,19 +1062,13 @@ static void blkfront_connect(struct blkfront_info *info)
/*
* If there's no "feature-barrier" defined, then it means
* we're dealing with a very old backend which writes
- * synchronously; draining will do what needs to get done.
+ * synchronously; nothing to do.
*
* If there are barriers, then we use flush.
- *
- * If barriers are not supported, then there's no much we can
- * do, so just set ordering to NONE.
*/
- if (err)
- info->feature_barrier = QUEUE_ORDERED_DRAIN;
- else if (barrier)
- info->feature_barrier = QUEUE_ORDERED_DRAIN_FLUSH;
- else
- info->feature_barrier = QUEUE_ORDERED_NONE;
+ info->feature_flush = 0;
+ if (!err && barrier)
+ info->feature_flush = REQ_FLUSH;
err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size);
if (err) {
diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c
index 7433e07..7c5b01c 100644
--- a/drivers/ide/ide-disk.c
+++ b/drivers/ide/ide-disk.c
@@ -516,10 +516,10 @@ static int ide_do_setfeature(ide_drive_t *drive, u8 feature, u8 nsect)
return ide_no_data_taskfile(drive, &cmd);
}
-static void update_ordered(ide_drive_t *drive)
+static void update_flush(ide_drive_t *drive)
{
u16 *id = drive->id;
- unsigned ordered = QUEUE_ORDERED_NONE;
+ unsigned flush = 0;
if (drive->dev_flags & IDE_DFLAG_WCACHE) {
unsigned long long capacity;
@@ -543,13 +543,12 @@ static void update_ordered(ide_drive_t *drive)
drive->name, barrier ? "" : "not ");
if (barrier) {
- ordered = QUEUE_ORDERED_DRAIN_FLUSH;
+ flush = REQ_FLUSH;
blk_queue_prep_rq(drive->queue, idedisk_prep_fn);
}
- } else
- ordered = QUEUE_ORDERED_DRAIN;
+ }
- blk_queue_ordered(drive->queue, ordered);
+ blk_queue_flush(drive->queue, flush);
}
ide_devset_get_flag(wcache, IDE_DFLAG_WCACHE);
@@ -572,7 +571,7 @@ static int set_wcache(ide_drive_t *drive, int arg)
}
}
- update_ordered(drive);
+ update_flush(drive);
return err;
}
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index ac384b2..b1d92be 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2245,7 +2245,7 @@ static int dm_init_request_based_queue(struct mapped_device *md)
blk_queue_softirq_done(md->queue, dm_softirq_done);
blk_queue_prep_rq(md->queue, dm_prep_fn);
blk_queue_lld_busy(md->queue, dm_lld_busy);
- blk_queue_ordered(md->queue, QUEUE_ORDERED_DRAIN_FLUSH);
+ blk_queue_flush(md->queue, REQ_FLUSH);
elv_register_queue(md->queue);
diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index e876678..9c0b42b 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -128,7 +128,6 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock
mq->req = NULL;
blk_queue_prep_rq(mq->queue, mmc_prep_request);
- blk_queue_ordered(mq->queue, QUEUE_ORDERED_DRAIN);
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue);
if (mmc_can_erase(card)) {
queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mq->queue);
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 8373ca0..9b106d8 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -2197,7 +2197,6 @@ static void dasd_setup_queue(struct dasd_block *block)
*/
blk_queue_max_segment_size(block->request_queue, PAGE_SIZE);
blk_queue_segment_boundary(block->request_queue, PAGE_SIZE - 1);
- blk_queue_ordered(block->request_queue, QUEUE_ORDERED_DRAIN);
}
/*
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index cdfc51a..63bd01a 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2109,7 +2109,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
struct scsi_disk *sdkp = scsi_disk(disk);
struct scsi_device *sdp = sdkp->device;
unsigned char *buffer;
- unsigned ordered;
+ unsigned flush = 0;
SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp,
"sd_revalidate_disk\n"));
@@ -2151,15 +2151,15 @@ static int sd_revalidate_disk(struct gendisk *disk)
/*
* We now have all cache related info, determine how we deal
- * with ordered requests.
+ * with flush requests.
*/
- if (sdkp->WCE)
- ordered = sdkp->DPOFUA
- ? QUEUE_ORDERED_DRAIN_FUA : QUEUE_ORDERED_DRAIN_FLUSH;
- else
- ordered = QUEUE_ORDERED_DRAIN;
+ if (sdkp->WCE) {
+ flush |= REQ_FLUSH;
+ if (sdkp->DPOFUA)
+ flush |= REQ_FUA;
+ }
- blk_queue_ordered(sdkp->disk->queue, ordered);
+ blk_queue_flush(sdkp->disk->queue, flush);
set_capacity(disk, sdkp->capacity);
kfree(buffer);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 7077bc0..e97911d 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -355,8 +355,10 @@ struct request_queue
struct blk_trace *blk_trace;
#endif
/*
- * reserved for flush operations
+ * for flush operations
*/
+ unsigned int flush_flags;
+
unsigned int ordered, next_ordered, ordseq;
int orderr, ordcolor;
struct request pre_flush_rq, bar_rq, post_flush_rq;
@@ -865,8 +867,8 @@ extern void blk_queue_update_dma_alignment(struct request_queue *, int);
extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
+extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
-extern int blk_queue_ordered(struct request_queue *, unsigned);
extern bool blk_do_ordered(struct request_queue *, struct request **);
extern unsigned blk_ordered_cur_seq(struct request_queue *);
extern unsigned blk_ordered_req_seq(struct request *);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 04/41] block: deprecate barrier and replace blk_queue_ordered() with blk_queue_flush()
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo, Christoph Hellwig, Nick Piggin, Jeremy Fitzhardinge,
Chris Wright, FUJITA Tomonori, Geert Uytterhoeven,
David S. Miller, Alasdair G Kergon, Pierre Ossman,
Stefan Weinhuber
Barrier is deemed too heavy and will soon be replaced by FLUSH/FUA
requests. Deprecate barrier. All REQ_HARDBARRIERs are failed with
-EOPNOTSUPP and blk_queue_ordered() is replaced with simpler
blk_queue_flush().
blk_queue_flush() takes combinations of REQ_FLUSH and FUA. If a
device has write cache and can flush it, it should set REQ_FLUSH. If
the device can handle FUA writes, it should also set REQ_FUA.
All blk_queue_ordered() users are converted.
* ORDERED_DRAIN is mapped to 0 which is the default value.
* ORDERED_DRAIN_FLUSH is mapped to REQ_FLUSH.
* ORDERED_DRAIN_FLUSH_FUA is mapped to REQ_FLUSH | REQ_FUA.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Boaz Harrosh <bharrosh@panasas.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Alasdair G Kergon <agk@redhat.com>
Cc: Pierre Ossman <drzeus@drzeus.cx>
Cc: Stefan Weinhuber <wein@de.ibm.com>
---
block/blk-barrier.c | 29 ----------------------------
block/blk-core.c | 6 +++-
block/blk-settings.c | 20 +++++++++++++++++++
drivers/block/brd.c | 1 -
drivers/block/loop.c | 2 +-
drivers/block/osdblk.c | 2 +-
drivers/block/ps3disk.c | 2 +-
drivers/block/virtio_blk.c | 25 ++++++++---------------
drivers/block/xen-blkfront.c | 43 +++++++++++------------------------------
drivers/ide/ide-disk.c | 13 +++++------
drivers/md/dm.c | 2 +-
drivers/mmc/card/queue.c | 1 -
drivers/s390/block/dasd.c | 1 -
drivers/scsi/sd.c | 16 +++++++-------
include/linux/blkdev.h | 6 +++-
15 files changed, 67 insertions(+), 102 deletions(-)
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index c807e9c..ed0aba5 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -9,35 +9,6 @@
#include "blk.h"
-/**
- * blk_queue_ordered - does this queue support ordered writes
- * @q: the request queue
- * @ordered: one of QUEUE_ORDERED_*
- *
- * Description:
- * For journalled file systems, doing ordered writes on a commit
- * block instead of explicitly doing wait_on_buffer (which is bad
- * for performance) can be a big win. Block drivers supporting this
- * feature should call this function and indicate so.
- *
- **/
-int blk_queue_ordered(struct request_queue *q, unsigned ordered)
-{
- if (ordered != QUEUE_ORDERED_NONE &&
- ordered != QUEUE_ORDERED_DRAIN &&
- ordered != QUEUE_ORDERED_DRAIN_FLUSH &&
- ordered != QUEUE_ORDERED_DRAIN_FUA) {
- printk(KERN_ERR "blk_queue_ordered: bad value %d\n", ordered);
- return -EINVAL;
- }
-
- q->ordered = ordered;
- q->next_ordered = ordered;
-
- return 0;
-}
-EXPORT_SYMBOL(blk_queue_ordered);
-
/*
* Cache flushing for ordered writes handling
*/
diff --git a/block/blk-core.c b/block/blk-core.c
index ee1a1e7..f063541 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1203,11 +1203,13 @@ static int __make_request(struct request_queue *q, struct bio *bio)
const unsigned int ff = bio->bi_rw & REQ_FAILFAST_MASK;
int rw_flags;
- if ((bio->bi_rw & REQ_HARDBARRIER) &&
- (q->next_ordered == QUEUE_ORDERED_NONE)) {
+ /* REQ_HARDBARRIER is no more */
+ if (WARN_ONCE(bio->bi_rw & REQ_HARDBARRIER,
+ "block: HARDBARRIER is deprecated, use FLUSH/FUA instead\n")) {
bio_endio(bio, -EOPNOTSUPP);
return 0;
}
+
/*
* low level driver can indicate that it wants pages above a
* certain limit bounced to low memory (ie for highmem, or even
diff --git a/block/blk-settings.c b/block/blk-settings.c
index a234f4b..9b18afc 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -794,6 +794,26 @@ void blk_queue_update_dma_alignment(struct request_queue *q, int mask)
}
EXPORT_SYMBOL(blk_queue_update_dma_alignment);
+/**
+ * blk_queue_flush - configure queue's cache flush capability
+ * @q: the request queue for the device
+ * @flush: 0, REQ_FLUSH or REQ_FLUSH | REQ_FUA
+ *
+ * Tell block layer cache flush capability of @q. If it supports
+ * flushing, REQ_FLUSH should be set. If it supports bypassing
+ * write cache for individual writes, REQ_FUA should be set.
+ */
+void blk_queue_flush(struct request_queue *q, unsigned int flush)
+{
+ WARN_ON_ONCE(flush & ~(REQ_FLUSH | REQ_FUA));
+
+ if (WARN_ON_ONCE(!(flush & REQ_FLUSH) && (flush & REQ_FUA)))
+ flush &= ~REQ_FUA;
+
+ q->flush_flags = flush & (REQ_FLUSH | REQ_FUA);
+}
+EXPORT_SYMBOL_GPL(blk_queue_flush);
+
static int __init blk_settings_init(void)
{
blk_max_low_pfn = max_low_pfn - 1;
diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index 47a4127..fa33f97 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -482,7 +482,6 @@ static struct brd_device *brd_alloc(int i)
if (!brd->brd_queue)
goto out_free_dev;
blk_queue_make_request(brd->brd_queue, brd_make_request);
- blk_queue_ordered(brd->brd_queue, QUEUE_ORDERED_DRAIN);
blk_queue_max_hw_sectors(brd->brd_queue, 1024);
blk_queue_bounce_limit(brd->brd_queue, BLK_BOUNCE_ANY);
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index c3a4a2e..953d1e1 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -832,7 +832,7 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
lo->lo_queue->unplug_fn = loop_unplug;
if (!(lo_flags & LO_FLAGS_READ_ONLY) && file->f_op->fsync)
- blk_queue_ordered(lo->lo_queue, QUEUE_ORDERED_DRAIN_FLUSH);
+ blk_queue_flush(lo->lo_queue, REQ_FLUSH);
set_capacity(lo->lo_disk, size);
bd_set_size(bdev, size << 9);
diff --git a/drivers/block/osdblk.c b/drivers/block/osdblk.c
index 2284b4f..72d6246 100644
--- a/drivers/block/osdblk.c
+++ b/drivers/block/osdblk.c
@@ -439,7 +439,7 @@ static int osdblk_init_disk(struct osdblk_device *osdev)
blk_queue_stack_limits(q, osd_request_queue(osdev->osd));
blk_queue_prep_rq(q, blk_queue_start_tag);
- blk_queue_ordered(q, QUEUE_ORDERED_DRAIN_FLUSH);
+ blk_queue_flush(q, REQ_FLUSH);
disk->queue = q;
diff --git a/drivers/block/ps3disk.c b/drivers/block/ps3disk.c
index e9da874..4911f9e 100644
--- a/drivers/block/ps3disk.c
+++ b/drivers/block/ps3disk.c
@@ -468,7 +468,7 @@ static int __devinit ps3disk_probe(struct ps3_system_bus_device *_dev)
blk_queue_dma_alignment(queue, dev->blk_size-1);
blk_queue_logical_block_size(queue, dev->blk_size);
- blk_queue_ordered(queue, QUEUE_ORDERED_DRAIN_FLUSH);
+ blk_queue_flush(queue, REQ_FLUSH);
blk_queue_max_segments(queue, -1);
blk_queue_max_segment_size(queue, dev->bounce_size);
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 7965280..d10b635 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -388,22 +388,15 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
vblk->disk->driverfs_dev = &vdev->dev;
index++;
- if (virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH)) {
- /*
- * If the FLUSH feature is supported we do have support for
- * flushing a volatile write cache on the host. Use that
- * to implement write barrier support.
- */
- blk_queue_ordered(q, QUEUE_ORDERED_DRAIN_FLUSH);
- } else {
- /*
- * If the FLUSH feature is not supported we must assume that
- * the host does not perform any kind of volatile write
- * caching. We still need to drain the queue to provider
- * proper barrier semantics.
- */
- blk_queue_ordered(q, QUEUE_ORDERED_DRAIN);
- }
+ /*
+ * If the FLUSH feature is supported we do have support for
+ * flushing a volatile write cache on the host. Use that to
+ * implement write barrier support; otherwise, we must assume
+ * that the host does not perform any kind of volatile write
+ * caching.
+ */
+ if (virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH))
+ blk_queue_flush(q, REQ_FLUSH);
/* If disk is read-only in the host, the guest should obey */
if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 8341862..f2ffc46 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -95,7 +95,7 @@ struct blkfront_info
struct gnttab_free_callback callback;
struct blk_shadow shadow[BLK_RING_SIZE];
unsigned long shadow_free;
- int feature_barrier;
+ unsigned int feature_flush;
int is_ready;
};
@@ -418,25 +418,12 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size)
}
-static int xlvbd_barrier(struct blkfront_info *info)
+static void xlvbd_flush(struct blkfront_info *info)
{
- int err;
- const char *barrier;
-
- switch (info->feature_barrier) {
- case QUEUE_ORDERED_DRAIN: barrier = "enabled"; break;
- case QUEUE_ORDERED_NONE: barrier = "disabled"; break;
- default: return -EINVAL;
- }
-
- err = blk_queue_ordered(info->rq, info->feature_barrier);
-
- if (err)
- return err;
-
+ blk_queue_flush(info->rq, info->feature_flush);
printk(KERN_INFO "blkfront: %s: barriers %s\n",
- info->gd->disk_name, barrier);
- return 0;
+ info->gd->disk_name,
+ info->feature_flush ? "enabled" : "disabled");
}
@@ -515,7 +502,7 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity,
info->rq = gd->queue;
info->gd = gd;
- xlvbd_barrier(info);
+ xlvbd_flush(info);
if (vdisk_info & VDISK_READONLY)
set_disk_ro(gd, 1);
@@ -661,8 +648,8 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
printk(KERN_WARNING "blkfront: %s: write barrier op failed\n",
info->gd->disk_name);
error = -EOPNOTSUPP;
- info->feature_barrier = QUEUE_ORDERED_NONE;
- xlvbd_barrier(info);
+ info->feature_flush = 0;
+ xlvbd_flush(info);
}
/* fall through */
case BLKIF_OP_READ:
@@ -1075,19 +1062,13 @@ static void blkfront_connect(struct blkfront_info *info)
/*
* If there's no "feature-barrier" defined, then it means
* we're dealing with a very old backend which writes
- * synchronously; draining will do what needs to get done.
+ * synchronously; nothing to do.
*
* If there are barriers, then we use flush.
- *
- * If barriers are not supported, then there's no much we can
- * do, so just set ordering to NONE.
*/
- if (err)
- info->feature_barrier = QUEUE_ORDERED_DRAIN;
- else if (barrier)
- info->feature_barrier = QUEUE_ORDERED_DRAIN_FLUSH;
- else
- info->feature_barrier = QUEUE_ORDERED_NONE;
+ info->feature_flush = 0;
+ if (!err && barrier)
+ info->feature_flush = REQ_FLUSH;
err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size);
if (err) {
diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c
index 7433e07..7c5b01c 100644
--- a/drivers/ide/ide-disk.c
+++ b/drivers/ide/ide-disk.c
@@ -516,10 +516,10 @@ static int ide_do_setfeature(ide_drive_t *drive, u8 feature, u8 nsect)
return ide_no_data_taskfile(drive, &cmd);
}
-static void update_ordered(ide_drive_t *drive)
+static void update_flush(ide_drive_t *drive)
{
u16 *id = drive->id;
- unsigned ordered = QUEUE_ORDERED_NONE;
+ unsigned flush = 0;
if (drive->dev_flags & IDE_DFLAG_WCACHE) {
unsigned long long capacity;
@@ -543,13 +543,12 @@ static void update_ordered(ide_drive_t *drive)
drive->name, barrier ? "" : "not ");
if (barrier) {
- ordered = QUEUE_ORDERED_DRAIN_FLUSH;
+ flush = REQ_FLUSH;
blk_queue_prep_rq(drive->queue, idedisk_prep_fn);
}
- } else
- ordered = QUEUE_ORDERED_DRAIN;
+ }
- blk_queue_ordered(drive->queue, ordered);
+ blk_queue_flush(drive->queue, flush);
}
ide_devset_get_flag(wcache, IDE_DFLAG_WCACHE);
@@ -572,7 +571,7 @@ static int set_wcache(ide_drive_t *drive, int arg)
}
}
- update_ordered(drive);
+ update_flush(drive);
return err;
}
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index ac384b2..b1d92be 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2245,7 +2245,7 @@ static int dm_init_request_based_queue(struct mapped_device *md)
blk_queue_softirq_done(md->queue, dm_softirq_done);
blk_queue_prep_rq(md->queue, dm_prep_fn);
blk_queue_lld_busy(md->queue, dm_lld_busy);
- blk_queue_ordered(md->queue, QUEUE_ORDERED_DRAIN_FLUSH);
+ blk_queue_flush(md->queue, REQ_FLUSH);
elv_register_queue(md->queue);
diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index e876678..9c0b42b 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -128,7 +128,6 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock
mq->req = NULL;
blk_queue_prep_rq(mq->queue, mmc_prep_request);
- blk_queue_ordered(mq->queue, QUEUE_ORDERED_DRAIN);
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue);
if (mmc_can_erase(card)) {
queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mq->queue);
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 8373ca0..9b106d8 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -2197,7 +2197,6 @@ static void dasd_setup_queue(struct dasd_block *block)
*/
blk_queue_max_segment_size(block->request_queue, PAGE_SIZE);
blk_queue_segment_boundary(block->request_queue, PAGE_SIZE - 1);
- blk_queue_ordered(block->request_queue, QUEUE_ORDERED_DRAIN);
}
/*
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index cdfc51a..63bd01a 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2109,7 +2109,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
struct scsi_disk *sdkp = scsi_disk(disk);
struct scsi_device *sdp = sdkp->device;
unsigned char *buffer;
- unsigned ordered;
+ unsigned flush = 0;
SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp,
"sd_revalidate_disk\n"));
@@ -2151,15 +2151,15 @@ static int sd_revalidate_disk(struct gendisk *disk)
/*
* We now have all cache related info, determine how we deal
- * with ordered requests.
+ * with flush requests.
*/
- if (sdkp->WCE)
- ordered = sdkp->DPOFUA
- ? QUEUE_ORDERED_DRAIN_FUA : QUEUE_ORDERED_DRAIN_FLUSH;
- else
- ordered = QUEUE_ORDERED_DRAIN;
+ if (sdkp->WCE) {
+ flush |= REQ_FLUSH;
+ if (sdkp->DPOFUA)
+ flush |= REQ_FUA;
+ }
- blk_queue_ordered(sdkp->disk->queue, ordered);
+ blk_queue_flush(sdkp->disk->queue, flush);
set_capacity(disk, sdkp->capacity);
kfree(buffer);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 7077bc0..e97911d 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -355,8 +355,10 @@ struct request_queue
struct blk_trace *blk_trace;
#endif
/*
- * reserved for flush operations
+ * for flush operations
*/
+ unsigned int flush_flags;
+
unsigned int ordered, next_ordered, ordseq;
int orderr, ordcolor;
struct request pre_flush_rq, bar_rq, post_flush_rq;
@@ -865,8 +867,8 @@ extern void blk_queue_update_dma_alignment(struct request_queue *, int);
extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
+extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
-extern int blk_queue_ordered(struct request_queue *, unsigned);
extern bool blk_do_ordered(struct request_queue *, struct request **);
extern unsigned blk_ordered_cur_seq(struct request_queue *);
extern unsigned blk_ordered_req_seq(struct request *);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 05/41] block: remove spurious uses of REQ_HARDBARRIER
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo, Peter Osterlund
REQ_HARDBARRIER is deprecated. Remove spurious uses in the following
users. Please note that other than osdblk, all other uses were
already spurious before deprecation.
* osdblk: osdblk_rq_fn() won't receive any request with
REQ_HARDBARRIER set. Remove the test for it.
* pktcdvd: use of REQ_HARDBARRIER in pkt_generic_packet() doesn't mean
anything. Removed.
* aic7xxx_old: Setting MSG_ORDERED_Q_TAG on REQ_HARDBARRIER is
spurious. Removed.
* sas_scsi_host: Setting TASK_ATTR_ORDERED on REQ_HARDBARRIER is
spurious. Removed.
* scsi_tcq: The ordered tag path wasn't being used anyway. Removed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Boaz Harrosh <bharrosh@panasas.com>
Cc: James Bottomley <James.Bottomley@suse.de>
Cc: Peter Osterlund <petero2@telia.com>
---
drivers/block/osdblk.c | 3 +--
drivers/block/pktcdvd.c | 1 -
drivers/scsi/aic7xxx_old.c | 21 ++-------------------
drivers/scsi/libsas/sas_scsi_host.c | 13 +------------
include/scsi/scsi_tcq.h | 6 +-----
5 files changed, 5 insertions(+), 39 deletions(-)
diff --git a/drivers/block/osdblk.c b/drivers/block/osdblk.c
index 72d6246..87311eb 100644
--- a/drivers/block/osdblk.c
+++ b/drivers/block/osdblk.c
@@ -310,8 +310,7 @@ static void osdblk_rq_fn(struct request_queue *q)
break;
/* filter out block requests we don't understand */
- if (rq->cmd_type != REQ_TYPE_FS &&
- !(rq->cmd_flags & REQ_HARDBARRIER)) {
+ if (rq->cmd_type != REQ_TYPE_FS) {
blk_end_request_all(rq, 0);
continue;
}
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index b1cbeb5..0166ea1 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -753,7 +753,6 @@ static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *
rq->timeout = 60*HZ;
rq->cmd_type = REQ_TYPE_BLOCK_PC;
- rq->cmd_flags |= REQ_HARDBARRIER;
if (cgc->quiet)
rq->cmd_flags |= REQ_QUIET;
diff --git a/drivers/scsi/aic7xxx_old.c b/drivers/scsi/aic7xxx_old.c
index 93984c9..e1cd606 100644
--- a/drivers/scsi/aic7xxx_old.c
+++ b/drivers/scsi/aic7xxx_old.c
@@ -2850,12 +2850,6 @@ aic7xxx_done(struct aic7xxx_host *p, struct aic7xxx_scb *scb)
aic_dev->r_total++;
ptr = aic_dev->r_bins;
}
- if(cmd->device->simple_tags && cmd->request->cmd_flags & REQ_HARDBARRIER)
- {
- aic_dev->barrier_total++;
- if(scb->tag_action == MSG_ORDERED_Q_TAG)
- aic_dev->ordered_total++;
- }
x = scb->sg_length;
x >>= 10;
for(i=0; i<6; i++)
@@ -10144,19 +10138,8 @@ static void aic7xxx_buildscb(struct aic7xxx_host *p, struct scsi_cmnd *cmd,
/* We always force TEST_UNIT_READY to untagged */
if (cmd->cmnd[0] != TEST_UNIT_READY && sdptr->simple_tags)
{
- if (req->cmd_flags & REQ_HARDBARRIER)
- {
- if(sdptr->ordered_tags)
- {
- hscb->control |= MSG_ORDERED_Q_TAG;
- scb->tag_action = MSG_ORDERED_Q_TAG;
- }
- }
- else
- {
- hscb->control |= MSG_SIMPLE_Q_TAG;
- scb->tag_action = MSG_SIMPLE_Q_TAG;
- }
+ hscb->control |= MSG_SIMPLE_Q_TAG;
+ scb->tag_action = MSG_SIMPLE_Q_TAG;
}
}
if ( !(aic_dev->dtr_pending) &&
diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index f0cfba9..535085c 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -130,17 +130,6 @@ static void sas_scsi_task_done(struct sas_task *task)
sc->scsi_done(sc);
}
-static enum task_attribute sas_scsi_get_task_attr(struct scsi_cmnd *cmd)
-{
- enum task_attribute ta = TASK_ATTR_SIMPLE;
- if (cmd->request && blk_rq_tagged(cmd->request)) {
- if (cmd->device->ordered_tags &&
- (cmd->request->cmd_flags & REQ_HARDBARRIER))
- ta = TASK_ATTR_ORDERED;
- }
- return ta;
-}
-
static struct sas_task *sas_create_task(struct scsi_cmnd *cmd,
struct domain_device *dev,
gfp_t gfp_flags)
@@ -160,7 +149,7 @@ static struct sas_task *sas_create_task(struct scsi_cmnd *cmd,
task->ssp_task.retry_count = 1;
int_to_scsilun(cmd->device->lun, &lun);
memcpy(task->ssp_task.LUN, &lun.scsi_lun, 8);
- task->ssp_task.task_attr = sas_scsi_get_task_attr(cmd);
+ task->ssp_task.task_attr = TASK_ATTR_SIMPLE;
memcpy(task->ssp_task.cdb, cmd->cmnd, 16);
task->scatter = scsi_sglist(cmd);
diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h
index 1723138..d6e7994 100644
--- a/include/scsi/scsi_tcq.h
+++ b/include/scsi/scsi_tcq.h
@@ -97,13 +97,9 @@ static inline void scsi_deactivate_tcq(struct scsi_device *sdev, int depth)
static inline int scsi_populate_tag_msg(struct scsi_cmnd *cmd, char *msg)
{
struct request *req = cmd->request;
- struct scsi_device *sdev = cmd->device;
if (blk_rq_tagged(req)) {
- if (sdev->ordered_tags && req->cmd_flags & REQ_HARDBARRIER)
- *msg++ = MSG_ORDERED_TAG;
- else
- *msg++ = MSG_SIMPLE_TAG;
+ *msg++ = MSG_SIMPLE_TAG;
*msg++ = req->tag;
return 2;
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 05/41] block: remove spurious uses of REQ_HARDBARRIER
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo, Peter Osterlund
REQ_HARDBARRIER is deprecated. Remove spurious uses in the following
users. Please note that other than osdblk, all other uses were
already spurious before deprecation.
* osdblk: osdblk_rq_fn() won't receive any request with
REQ_HARDBARRIER set. Remove the test for it.
* pktcdvd: use of REQ_HARDBARRIER in pkt_generic_packet() doesn't mean
anything. Removed.
* aic7xxx_old: Setting MSG_ORDERED_Q_TAG on REQ_HARDBARRIER is
spurious. Removed.
* sas_scsi_host: Setting TASK_ATTR_ORDERED on REQ_HARDBARRIER is
spurious. Removed.
* scsi_tcq: The ordered tag path wasn't being used anyway. Removed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Boaz Harrosh <bharrosh@panasas.com>
Cc: James Bottomley <James.Bottomley@suse.de>
Cc: Peter Osterlund <petero2@telia.com>
---
drivers/block/osdblk.c | 3 +--
drivers/block/pktcdvd.c | 1 -
drivers/scsi/aic7xxx_old.c | 21 ++-------------------
drivers/scsi/libsas/sas_scsi_host.c | 13 +------------
include/scsi/scsi_tcq.h | 6 +-----
5 files changed, 5 insertions(+), 39 deletions(-)
diff --git a/drivers/block/osdblk.c b/drivers/block/osdblk.c
index 72d6246..87311eb 100644
--- a/drivers/block/osdblk.c
+++ b/drivers/block/osdblk.c
@@ -310,8 +310,7 @@ static void osdblk_rq_fn(struct request_queue *q)
break;
/* filter out block requests we don't understand */
- if (rq->cmd_type != REQ_TYPE_FS &&
- !(rq->cmd_flags & REQ_HARDBARRIER)) {
+ if (rq->cmd_type != REQ_TYPE_FS) {
blk_end_request_all(rq, 0);
continue;
}
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index b1cbeb5..0166ea1 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -753,7 +753,6 @@ static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *
rq->timeout = 60*HZ;
rq->cmd_type = REQ_TYPE_BLOCK_PC;
- rq->cmd_flags |= REQ_HARDBARRIER;
if (cgc->quiet)
rq->cmd_flags |= REQ_QUIET;
diff --git a/drivers/scsi/aic7xxx_old.c b/drivers/scsi/aic7xxx_old.c
index 93984c9..e1cd606 100644
--- a/drivers/scsi/aic7xxx_old.c
+++ b/drivers/scsi/aic7xxx_old.c
@@ -2850,12 +2850,6 @@ aic7xxx_done(struct aic7xxx_host *p, struct aic7xxx_scb *scb)
aic_dev->r_total++;
ptr = aic_dev->r_bins;
}
- if(cmd->device->simple_tags && cmd->request->cmd_flags & REQ_HARDBARRIER)
- {
- aic_dev->barrier_total++;
- if(scb->tag_action == MSG_ORDERED_Q_TAG)
- aic_dev->ordered_total++;
- }
x = scb->sg_length;
x >>= 10;
for(i=0; i<6; i++)
@@ -10144,19 +10138,8 @@ static void aic7xxx_buildscb(struct aic7xxx_host *p, struct scsi_cmnd *cmd,
/* We always force TEST_UNIT_READY to untagged */
if (cmd->cmnd[0] != TEST_UNIT_READY && sdptr->simple_tags)
{
- if (req->cmd_flags & REQ_HARDBARRIER)
- {
- if(sdptr->ordered_tags)
- {
- hscb->control |= MSG_ORDERED_Q_TAG;
- scb->tag_action = MSG_ORDERED_Q_TAG;
- }
- }
- else
- {
- hscb->control |= MSG_SIMPLE_Q_TAG;
- scb->tag_action = MSG_SIMPLE_Q_TAG;
- }
+ hscb->control |= MSG_SIMPLE_Q_TAG;
+ scb->tag_action = MSG_SIMPLE_Q_TAG;
}
}
if ( !(aic_dev->dtr_pending) &&
diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index f0cfba9..535085c 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -130,17 +130,6 @@ static void sas_scsi_task_done(struct sas_task *task)
sc->scsi_done(sc);
}
-static enum task_attribute sas_scsi_get_task_attr(struct scsi_cmnd *cmd)
-{
- enum task_attribute ta = TASK_ATTR_SIMPLE;
- if (cmd->request && blk_rq_tagged(cmd->request)) {
- if (cmd->device->ordered_tags &&
- (cmd->request->cmd_flags & REQ_HARDBARRIER))
- ta = TASK_ATTR_ORDERED;
- }
- return ta;
-}
-
static struct sas_task *sas_create_task(struct scsi_cmnd *cmd,
struct domain_device *dev,
gfp_t gfp_flags)
@@ -160,7 +149,7 @@ static struct sas_task *sas_create_task(struct scsi_cmnd *cmd,
task->ssp_task.retry_count = 1;
int_to_scsilun(cmd->device->lun, &lun);
memcpy(task->ssp_task.LUN, &lun.scsi_lun, 8);
- task->ssp_task.task_attr = sas_scsi_get_task_attr(cmd);
+ task->ssp_task.task_attr = TASK_ATTR_SIMPLE;
memcpy(task->ssp_task.cdb, cmd->cmnd, 16);
task->scatter = scsi_sglist(cmd);
diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h
index 1723138..d6e7994 100644
--- a/include/scsi/scsi_tcq.h
+++ b/include/scsi/scsi_tcq.h
@@ -97,13 +97,9 @@ static inline void scsi_deactivate_tcq(struct scsi_device *sdev, int depth)
static inline int scsi_populate_tag_msg(struct scsi_cmnd *cmd, char *msg)
{
struct request *req = cmd->request;
- struct scsi_device *sdev = cmd->device;
if (blk_rq_tagged(req)) {
- if (sdev->ordered_tags && req->cmd_flags & REQ_HARDBARRIER)
- *msg++ = MSG_ORDERED_TAG;
- else
- *msg++ = MSG_SIMPLE_TAG;
+ *msg++ = MSG_SIMPLE_TAG;
*msg++ = req->tag;
return 2;
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 05/41] block: remove spurious uses of REQ_HARDBARRIER
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo, Peter Osterlund
REQ_HARDBARRIER is deprecated. Remove spurious uses in the following
users. Please note that other than osdblk, all other uses were
already spurious before deprecation.
* osdblk: osdblk_rq_fn() won't receive any request with
REQ_HARDBARRIER set. Remove the test for it.
* pktcdvd: use of REQ_HARDBARRIER in pkt_generic_packet() doesn't mean
anything. Removed.
* aic7xxx_old: Setting MSG_ORDERED_Q_TAG on REQ_HARDBARRIER is
spurious. Removed.
* sas_scsi_host: Setting TASK_ATTR_ORDERED on REQ_HARDBARRIER is
spurious. Removed.
* scsi_tcq: The ordered tag path wasn't being used anyway. Removed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Boaz Harrosh <bharrosh@panasas.com>
Cc: James Bottomley <James.Bottomley@suse.de>
Cc: Peter Osterlund <petero2@telia.com>
---
drivers/block/osdblk.c | 3 +--
drivers/block/pktcdvd.c | 1 -
drivers/scsi/aic7xxx_old.c | 21 ++-------------------
drivers/scsi/libsas/sas_scsi_host.c | 13 +------------
include/scsi/scsi_tcq.h | 6 +-----
5 files changed, 5 insertions(+), 39 deletions(-)
diff --git a/drivers/block/osdblk.c b/drivers/block/osdblk.c
index 72d6246..87311eb 100644
--- a/drivers/block/osdblk.c
+++ b/drivers/block/osdblk.c
@@ -310,8 +310,7 @@ static void osdblk_rq_fn(struct request_queue *q)
break;
/* filter out block requests we don't understand */
- if (rq->cmd_type != REQ_TYPE_FS &&
- !(rq->cmd_flags & REQ_HARDBARRIER)) {
+ if (rq->cmd_type != REQ_TYPE_FS) {
blk_end_request_all(rq, 0);
continue;
}
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index b1cbeb5..0166ea1 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -753,7 +753,6 @@ static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *
rq->timeout = 60*HZ;
rq->cmd_type = REQ_TYPE_BLOCK_PC;
- rq->cmd_flags |= REQ_HARDBARRIER;
if (cgc->quiet)
rq->cmd_flags |= REQ_QUIET;
diff --git a/drivers/scsi/aic7xxx_old.c b/drivers/scsi/aic7xxx_old.c
index 93984c9..e1cd606 100644
--- a/drivers/scsi/aic7xxx_old.c
+++ b/drivers/scsi/aic7xxx_old.c
@@ -2850,12 +2850,6 @@ aic7xxx_done(struct aic7xxx_host *p, struct aic7xxx_scb *scb)
aic_dev->r_total++;
ptr = aic_dev->r_bins;
}
- if(cmd->device->simple_tags && cmd->request->cmd_flags & REQ_HARDBARRIER)
- {
- aic_dev->barrier_total++;
- if(scb->tag_action == MSG_ORDERED_Q_TAG)
- aic_dev->ordered_total++;
- }
x = scb->sg_length;
x >>= 10;
for(i=0; i<6; i++)
@@ -10144,19 +10138,8 @@ static void aic7xxx_buildscb(struct aic7xxx_host *p, struct scsi_cmnd *cmd,
/* We always force TEST_UNIT_READY to untagged */
if (cmd->cmnd[0] != TEST_UNIT_READY && sdptr->simple_tags)
{
- if (req->cmd_flags & REQ_HARDBARRIER)
- {
- if(sdptr->ordered_tags)
- {
- hscb->control |= MSG_ORDERED_Q_TAG;
- scb->tag_action = MSG_ORDERED_Q_TAG;
- }
- }
- else
- {
- hscb->control |= MSG_SIMPLE_Q_TAG;
- scb->tag_action = MSG_SIMPLE_Q_TAG;
- }
+ hscb->control |= MSG_SIMPLE_Q_TAG;
+ scb->tag_action = MSG_SIMPLE_Q_TAG;
}
}
if ( !(aic_dev->dtr_pending) &&
diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index f0cfba9..535085c 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -130,17 +130,6 @@ static void sas_scsi_task_done(struct sas_task *task)
sc->scsi_done(sc);
}
-static enum task_attribute sas_scsi_get_task_attr(struct scsi_cmnd *cmd)
-{
- enum task_attribute ta = TASK_ATTR_SIMPLE;
- if (cmd->request && blk_rq_tagged(cmd->request)) {
- if (cmd->device->ordered_tags &&
- (cmd->request->cmd_flags & REQ_HARDBARRIER))
- ta = TASK_ATTR_ORDERED;
- }
- return ta;
-}
-
static struct sas_task *sas_create_task(struct scsi_cmnd *cmd,
struct domain_device *dev,
gfp_t gfp_flags)
@@ -160,7 +149,7 @@ static struct sas_task *sas_create_task(struct scsi_cmnd *cmd,
task->ssp_task.retry_count = 1;
int_to_scsilun(cmd->device->lun, &lun);
memcpy(task->ssp_task.LUN, &lun.scsi_lun, 8);
- task->ssp_task.task_attr = sas_scsi_get_task_attr(cmd);
+ task->ssp_task.task_attr = TASK_ATTR_SIMPLE;
memcpy(task->ssp_task.cdb, cmd->cmnd, 16);
task->scatter = scsi_sglist(cmd);
diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h
index 1723138..d6e7994 100644
--- a/include/scsi/scsi_tcq.h
+++ b/include/scsi/scsi_tcq.h
@@ -97,13 +97,9 @@ static inline void scsi_deactivate_tcq(struct scsi_device *sdev, int depth)
static inline int scsi_populate_tag_msg(struct scsi_cmnd *cmd, char *msg)
{
struct request *req = cmd->request;
- struct scsi_device *sdev = cmd->device;
if (blk_rq_tagged(req)) {
- if (sdev->ordered_tags && req->cmd_flags & REQ_HARDBARRIER)
- *msg++ = MSG_ORDERED_TAG;
- else
- *msg++ = MSG_SIMPLE_TAG;
+ *msg++ = MSG_SIMPLE_TAG;
*msg++ = req->tag;
return 2;
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 06/41] block: misc cleanups in barrier code
2010-09-03 10:29 ` Tejun Heo
` (10 preceding siblings ...)
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
Make the following cleanups in preparation of barrier/flush update.
* blk_do_ordered() declaration is moved from include/linux/blkdev.h to
block/blk.h.
* blk_do_ordered() now returns pointer to struct request, with %NULL
meaning "try the next request" and ERR_PTR(-EAGAIN) "try again
later". The third case will be dropped with further changes.
* In the initialization of proxy barrier request, data direction is
already set by init_request_from_bio(). Drop unnecessary explicit
REQ_WRITE setting and move init_request_from_bio() above REQ_FUA
flag setting.
* add_request() is collapsed into __make_request().
These changes don't make any functional difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
block/blk-barrier.c | 32 ++++++++++++++------------------
block/blk-core.c | 21 ++++-----------------
block/blk.h | 7 +++++--
include/linux/blkdev.h | 1 -
4 files changed, 23 insertions(+), 38 deletions(-)
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index ed0aba5..f1be85b 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -110,9 +110,9 @@ static void queue_flush(struct request_queue *q, unsigned which)
elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
}
-static inline bool start_ordered(struct request_queue *q, struct request **rqp)
+static inline struct request *start_ordered(struct request_queue *q,
+ struct request *rq)
{
- struct request *rq = *rqp;
unsigned skip = 0;
q->orderr = 0;
@@ -149,11 +149,9 @@ static inline bool start_ordered(struct request_queue *q, struct request **rqp)
/* initialize proxy request and queue it */
blk_rq_init(q, rq);
- if (bio_data_dir(q->orig_bar_rq->bio) == WRITE)
- rq->cmd_flags |= REQ_WRITE;
+ init_request_from_bio(rq, q->orig_bar_rq->bio);
if (q->ordered & QUEUE_ORDERED_DO_FUA)
rq->cmd_flags |= REQ_FUA;
- init_request_from_bio(rq, q->orig_bar_rq->bio);
rq->end_io = bar_end_io;
elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
@@ -171,27 +169,26 @@ static inline bool start_ordered(struct request_queue *q, struct request **rqp)
else
skip |= QUEUE_ORDSEQ_DRAIN;
- *rqp = rq;
-
/*
* Complete skipped sequences. If whole sequence is complete,
- * return false to tell elevator that this request is gone.
+ * return %NULL to tell elevator that this request is gone.
*/
- return !blk_ordered_complete_seq(q, skip, 0);
+ if (blk_ordered_complete_seq(q, skip, 0))
+ rq = NULL;
+ return rq;
}
-bool blk_do_ordered(struct request_queue *q, struct request **rqp)
+struct request *blk_do_ordered(struct request_queue *q, struct request *rq)
{
- struct request *rq = *rqp;
const int is_barrier = rq->cmd_type == REQ_TYPE_FS &&
(rq->cmd_flags & REQ_HARDBARRIER);
if (!q->ordseq) {
if (!is_barrier)
- return true;
+ return rq;
if (q->next_ordered != QUEUE_ORDERED_NONE)
- return start_ordered(q, rqp);
+ return start_ordered(q, rq);
else {
/*
* Queue ordering not supported. Terminate
@@ -199,8 +196,7 @@ bool blk_do_ordered(struct request_queue *q, struct request **rqp)
*/
blk_dequeue_request(rq);
__blk_end_request_all(rq, -EOPNOTSUPP);
- *rqp = NULL;
- return false;
+ return NULL;
}
}
@@ -211,14 +207,14 @@ bool blk_do_ordered(struct request_queue *q, struct request **rqp)
/* Special requests are not subject to ordering rules. */
if (rq->cmd_type != REQ_TYPE_FS &&
rq != &q->pre_flush_rq && rq != &q->post_flush_rq)
- return true;
+ return rq;
/* Ordered by draining. Wait for turn. */
WARN_ON(blk_ordered_req_seq(rq) < blk_ordered_cur_seq(q));
if (blk_ordered_req_seq(rq) > blk_ordered_cur_seq(q))
- *rqp = NULL;
+ rq = ERR_PTR(-EAGAIN);
- return true;
+ return rq;
}
static void bio_end_empty_barrier(struct bio *bio, int err)
diff --git a/block/blk-core.c b/block/blk-core.c
index f063541..f8d37a8 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1037,22 +1037,6 @@ void blk_insert_request(struct request_queue *q, struct request *rq,
}
EXPORT_SYMBOL(blk_insert_request);
-/*
- * add-request adds a request to the linked list.
- * queue lock is held and interrupts disabled, as we muck with the
- * request queue list.
- */
-static inline void add_request(struct request_queue *q, struct request *req)
-{
- drive_stat_acct(req, 1);
-
- /*
- * elevator indicated where it wants this request to be
- * inserted at elevator_merge time
- */
- __elv_add_request(q, req, ELEVATOR_INSERT_SORT, 0);
-}
-
static void part_round_stats_single(int cpu, struct hd_struct *part,
unsigned long now)
{
@@ -1316,7 +1300,10 @@ get_rq:
req->cpu = blk_cpu_to_group(smp_processor_id());
if (queue_should_plug(q) && elv_queue_empty(q))
blk_plug_device(q);
- add_request(q, req);
+
+ /* insert the request into the elevator */
+ drive_stat_acct(req, 1);
+ __elv_add_request(q, req, ELEVATOR_INSERT_SORT, 0);
out:
if (unplug || !queue_should_plug(q))
__generic_unplug_device(q);
diff --git a/block/blk.h b/block/blk.h
index 6e7dc87..874eb4e 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -51,6 +51,8 @@ static inline void blk_clear_rq_complete(struct request *rq)
*/
#define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash))
+struct request *blk_do_ordered(struct request_queue *q, struct request *rq);
+
static inline struct request *__elv_next_request(struct request_queue *q)
{
struct request *rq;
@@ -58,8 +60,9 @@ static inline struct request *__elv_next_request(struct request_queue *q)
while (1) {
while (!list_empty(&q->queue_head)) {
rq = list_entry_rq(q->queue_head.next);
- if (blk_do_ordered(q, &rq))
- return rq;
+ rq = blk_do_ordered(q, rq);
+ if (rq)
+ return !IS_ERR(rq) ? rq : NULL;
}
if (!q->elevator->ops->elevator_dispatch_fn(q, 0))
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index e97911d..996549d 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -869,7 +869,6 @@ extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
-extern bool blk_do_ordered(struct request_queue *, struct request **);
extern unsigned blk_ordered_cur_seq(struct request_queue *);
extern unsigned blk_ordered_req_seq(struct request *);
extern bool blk_ordered_complete_seq(struct request_queue *, unsigned, int);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 06/41] block: misc cleanups in barrier code
2010-09-03 10:29 ` Tejun Heo
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel
Cc: Tejun Heo
Make the following cleanups in preparation of barrier/flush update.
* blk_do_ordered() declaration is moved from include/linux/blkdev.h to
block/blk.h.
* blk_do_ordered() now returns pointer to struct request, with %NULL
meaning "try the next request" and ERR_PTR(-EAGAIN) "try again
later". The third case will be dropped with further changes.
* In the initialization of proxy barrier request, data direction is
already set by init_request_from_bio(). Drop unnecessary explicit
REQ_WRITE setting and move init_request_from_bio() above REQ_FUA
flag setting.
* add_request() is collapsed into __make_request().
These changes don't make any functional difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
block/blk-barrier.c | 32 ++++++++++++++------------------
block/blk-core.c | 21 ++++-----------------
block/blk.h | 7 +++++--
include/linux/blkdev.h | 1 -
4 files changed, 23 insertions(+), 38 deletions(-)
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index ed0aba5..f1be85b 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -110,9 +110,9 @@ static void queue_flush(struct request_queue *q, unsigned which)
elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
}
-static inline bool start_ordered(struct request_queue *q, struct request **rqp)
+static inline struct request *start_ordered(struct request_queue *q,
+ struct request *rq)
{
- struct request *rq = *rqp;
unsigned skip = 0;
q->orderr = 0;
@@ -149,11 +149,9 @@ static inline bool start_ordered(struct request_queue *q, struct request **rqp)
/* initialize proxy request and queue it */
blk_rq_init(q, rq);
- if (bio_data_dir(q->orig_bar_rq->bio) == WRITE)
- rq->cmd_flags |= REQ_WRITE;
+ init_request_from_bio(rq, q->orig_bar_rq->bio);
if (q->ordered & QUEUE_ORDERED_DO_FUA)
rq->cmd_flags |= REQ_FUA;
- init_request_from_bio(rq, q->orig_bar_rq->bio);
rq->end_io = bar_end_io;
elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
@@ -171,27 +169,26 @@ static inline bool start_ordered(struct request_queue *q, struct request **rqp)
else
skip |= QUEUE_ORDSEQ_DRAIN;
- *rqp = rq;
-
/*
* Complete skipped sequences. If whole sequence is complete,
- * return false to tell elevator that this request is gone.
+ * return %NULL to tell elevator that this request is gone.
*/
- return !blk_ordered_complete_seq(q, skip, 0);
+ if (blk_ordered_complete_seq(q, skip, 0))
+ rq = NULL;
+ return rq;
}
-bool blk_do_ordered(struct request_queue *q, struct request **rqp)
+struct request *blk_do_ordered(struct request_queue *q, struct request *rq)
{
- struct request *rq = *rqp;
const int is_barrier = rq->cmd_type == REQ_TYPE_FS &&
(rq->cmd_flags & REQ_HARDBARRIER);
if (!q->ordseq) {
if (!is_barrier)
- return true;
+ return rq;
if (q->next_ordered != QUEUE_ORDERED_NONE)
- return start_ordered(q, rqp);
+ return start_ordered(q, rq);
else {
/*
* Queue ordering not supported. Terminate
@@ -199,8 +196,7 @@ bool blk_do_ordered(struct request_queue *q, struct request **rqp)
*/
blk_dequeue_request(rq);
__blk_end_request_all(rq, -EOPNOTSUPP);
- *rqp = NULL;
- return false;
+ return NULL;
}
}
@@ -211,14 +207,14 @@ bool blk_do_ordered(struct request_queue *q, struct request **rqp)
/* Special requests are not subject to ordering rules. */
if (rq->cmd_type != REQ_TYPE_FS &&
rq != &q->pre_flush_rq && rq != &q->post_flush_rq)
- return true;
+ return rq;
/* Ordered by draining. Wait for turn. */
WARN_ON(blk_ordered_req_seq(rq) < blk_ordered_cur_seq(q));
if (blk_ordered_req_seq(rq) > blk_ordered_cur_seq(q))
- *rqp = NULL;
+ rq = ERR_PTR(-EAGAIN);
- return true;
+ return rq;
}
static void bio_end_empty_barrier(struct bio *bio, int err)
diff --git a/block/blk-core.c b/block/blk-core.c
index f063541..f8d37a8 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1037,22 +1037,6 @@ void blk_insert_request(struct request_queue *q, struct request *rq,
}
EXPORT_SYMBOL(blk_insert_request);
-/*
- * add-request adds a request to the linked list.
- * queue lock is held and interrupts disabled, as we muck with the
- * request queue list.
- */
-static inline void add_request(struct request_queue *q, struct request *req)
-{
- drive_stat_acct(req, 1);
-
- /*
- * elevator indicated where it wants this request to be
- * inserted at elevator_merge time
- */
- __elv_add_request(q, req, ELEVATOR_INSERT_SORT, 0);
-}
-
static void part_round_stats_single(int cpu, struct hd_struct *part,
unsigned long now)
{
@@ -1316,7 +1300,10 @@ get_rq:
req->cpu = blk_cpu_to_group(smp_processor_id());
if (queue_should_plug(q) && elv_queue_empty(q))
blk_plug_device(q);
- add_request(q, req);
+
+ /* insert the request into the elevator */
+ drive_stat_acct(req, 1);
+ __elv_add_request(q, req, ELEVATOR_INSERT_SORT, 0);
out:
if (unplug || !queue_should_plug(q))
__generic_unplug_device(q);
diff --git a/block/blk.h b/block/blk.h
index 6e7dc87..874eb4e 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -51,6 +51,8 @@ static inline void blk_clear_rq_complete(struct request *rq)
*/
#define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash))
+struct request *blk_do_ordered(struct request_queue *q, struct request *rq);
+
static inline struct request *__elv_next_request(struct request_queue *q)
{
struct request *rq;
@@ -58,8 +60,9 @@ static inline struct request *__elv_next_request(struct request_queue *q)
while (1) {
while (!list_empty(&q->queue_head)) {
rq = list_entry_rq(q->queue_head.next);
- if (blk_do_ordered(q, &rq))
- return rq;
+ rq = blk_do_ordered(q, rq);
+ if (rq)
+ return !IS_ERR(rq) ? rq : NULL;
}
if (!q->elevator->ops->elevator_dispatch_fn(q, 0))
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index e97911d..996549d 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -869,7 +869,6 @@ extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
-extern bool blk_do_ordered(struct request_queue *, struct request **);
extern unsigned blk_ordered_cur_seq(struct request_queue *);
extern unsigned blk_ordered_req_seq(struct request *);
extern bool blk_ordered_complete_seq(struct request_queue *, unsigned, int);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 06/41] block: misc cleanups in barrier code
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo
Make the following cleanups in preparation of barrier/flush update.
* blk_do_ordered() declaration is moved from include/linux/blkdev.h to
block/blk.h.
* blk_do_ordered() now returns pointer to struct request, with %NULL
meaning "try the next request" and ERR_PTR(-EAGAIN) "try again
later". The third case will be dropped with further changes.
* In the initialization of proxy barrier request, data direction is
already set by init_request_from_bio(). Drop unnecessary explicit
REQ_WRITE setting and move init_request_from_bio() above REQ_FUA
flag setting.
* add_request() is collapsed into __make_request().
These changes don't make any functional difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
block/blk-barrier.c | 32 ++++++++++++++------------------
block/blk-core.c | 21 ++++-----------------
block/blk.h | 7 +++++--
include/linux/blkdev.h | 1 -
4 files changed, 23 insertions(+), 38 deletions(-)
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index ed0aba5..f1be85b 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -110,9 +110,9 @@ static void queue_flush(struct request_queue *q, unsigned which)
elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
}
-static inline bool start_ordered(struct request_queue *q, struct request **rqp)
+static inline struct request *start_ordered(struct request_queue *q,
+ struct request *rq)
{
- struct request *rq = *rqp;
unsigned skip = 0;
q->orderr = 0;
@@ -149,11 +149,9 @@ static inline bool start_ordered(struct request_queue *q, struct request **rqp)
/* initialize proxy request and queue it */
blk_rq_init(q, rq);
- if (bio_data_dir(q->orig_bar_rq->bio) == WRITE)
- rq->cmd_flags |= REQ_WRITE;
+ init_request_from_bio(rq, q->orig_bar_rq->bio);
if (q->ordered & QUEUE_ORDERED_DO_FUA)
rq->cmd_flags |= REQ_FUA;
- init_request_from_bio(rq, q->orig_bar_rq->bio);
rq->end_io = bar_end_io;
elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
@@ -171,27 +169,26 @@ static inline bool start_ordered(struct request_queue *q, struct request **rqp)
else
skip |= QUEUE_ORDSEQ_DRAIN;
- *rqp = rq;
-
/*
* Complete skipped sequences. If whole sequence is complete,
- * return false to tell elevator that this request is gone.
+ * return %NULL to tell elevator that this request is gone.
*/
- return !blk_ordered_complete_seq(q, skip, 0);
+ if (blk_ordered_complete_seq(q, skip, 0))
+ rq = NULL;
+ return rq;
}
-bool blk_do_ordered(struct request_queue *q, struct request **rqp)
+struct request *blk_do_ordered(struct request_queue *q, struct request *rq)
{
- struct request *rq = *rqp;
const int is_barrier = rq->cmd_type == REQ_TYPE_FS &&
(rq->cmd_flags & REQ_HARDBARRIER);
if (!q->ordseq) {
if (!is_barrier)
- return true;
+ return rq;
if (q->next_ordered != QUEUE_ORDERED_NONE)
- return start_ordered(q, rqp);
+ return start_ordered(q, rq);
else {
/*
* Queue ordering not supported. Terminate
@@ -199,8 +196,7 @@ bool blk_do_ordered(struct request_queue *q, struct request **rqp)
*/
blk_dequeue_request(rq);
__blk_end_request_all(rq, -EOPNOTSUPP);
- *rqp = NULL;
- return false;
+ return NULL;
}
}
@@ -211,14 +207,14 @@ bool blk_do_ordered(struct request_queue *q, struct request **rqp)
/* Special requests are not subject to ordering rules. */
if (rq->cmd_type != REQ_TYPE_FS &&
rq != &q->pre_flush_rq && rq != &q->post_flush_rq)
- return true;
+ return rq;
/* Ordered by draining. Wait for turn. */
WARN_ON(blk_ordered_req_seq(rq) < blk_ordered_cur_seq(q));
if (blk_ordered_req_seq(rq) > blk_ordered_cur_seq(q))
- *rqp = NULL;
+ rq = ERR_PTR(-EAGAIN);
- return true;
+ return rq;
}
static void bio_end_empty_barrier(struct bio *bio, int err)
diff --git a/block/blk-core.c b/block/blk-core.c
index f063541..f8d37a8 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1037,22 +1037,6 @@ void blk_insert_request(struct request_queue *q, struct request *rq,
}
EXPORT_SYMBOL(blk_insert_request);
-/*
- * add-request adds a request to the linked list.
- * queue lock is held and interrupts disabled, as we muck with the
- * request queue list.
- */
-static inline void add_request(struct request_queue *q, struct request *req)
-{
- drive_stat_acct(req, 1);
-
- /*
- * elevator indicated where it wants this request to be
- * inserted at elevator_merge time
- */
- __elv_add_request(q, req, ELEVATOR_INSERT_SORT, 0);
-}
-
static void part_round_stats_single(int cpu, struct hd_struct *part,
unsigned long now)
{
@@ -1316,7 +1300,10 @@ get_rq:
req->cpu = blk_cpu_to_group(smp_processor_id());
if (queue_should_plug(q) && elv_queue_empty(q))
blk_plug_device(q);
- add_request(q, req);
+
+ /* insert the request into the elevator */
+ drive_stat_acct(req, 1);
+ __elv_add_request(q, req, ELEVATOR_INSERT_SORT, 0);
out:
if (unplug || !queue_should_plug(q))
__generic_unplug_device(q);
diff --git a/block/blk.h b/block/blk.h
index 6e7dc87..874eb4e 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -51,6 +51,8 @@ static inline void blk_clear_rq_complete(struct request *rq)
*/
#define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash))
+struct request *blk_do_ordered(struct request_queue *q, struct request *rq);
+
static inline struct request *__elv_next_request(struct request_queue *q)
{
struct request *rq;
@@ -58,8 +60,9 @@ static inline struct request *__elv_next_request(struct request_queue *q)
while (1) {
while (!list_empty(&q->queue_head)) {
rq = list_entry_rq(q->queue_head.next);
- if (blk_do_ordered(q, &rq))
- return rq;
+ rq = blk_do_ordered(q, rq);
+ if (rq)
+ return !IS_ERR(rq) ? rq : NULL;
}
if (!q->elevator->ops->elevator_dispatch_fn(q, 0))
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index e97911d..996549d 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -869,7 +869,6 @@ extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
-extern bool blk_do_ordered(struct request_queue *, struct request **);
extern unsigned blk_ordered_cur_seq(struct request_queue *);
extern unsigned blk_ordered_req_seq(struct request *);
extern bool blk_ordered_complete_seq(struct request_queue *, unsigned, int);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 07/41] block: drop barrier ordering by queue draining
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo, Christoph Hellwig
Filesystems will take all the responsibilities for ordering requests
around commit writes and will only indicate how the commit writes
themselves should be handled by block layers. This patch drops
barrier ordering by queue draining from block layer. Ordering by
draining implementation was somewhat invasive to request handling.
List of notable changes follow.
* Each queue has 1 bit color which is flipped on each barrier issue.
This is used to track whether a given request is issued before the
current barrier or not. REQ_ORDERED_COLOR flag and coloring
implementation in __elv_add_request() are removed.
* Requests which shouldn't be processed yet for draining were stalled
by returning -EAGAIN from blk_do_ordered() according to the test
result between blk_ordered_req_seq() and blk_blk_ordered_cur_seq().
This logic is removed.
* Draining completion logic in elv_completed_request() removed.
* All barrier sequence requests were queued to request queue and then
trckled to lower layer according to progress and thus maintaining
request orders during requeue was necessary. This is replaced by
queueing the next request in the barrier sequence only after the
current one is complete from blk_ordered_complete_seq(), which
removes the need for multiple proxy requests in struct request_queue
and the request sorting logic in the ELEVATOR_INSERT_REQUEUE path of
elv_insert().
* As barriers no longer have ordering constraints, there's no need to
dump the whole elevator onto the dispatch queue on each barrier.
Insert barriers at the front instead.
* If other barrier requests come to the front of the dispatch queue
while one is already in progress, they are stored in
q->pending_barriers and restored to dispatch queue one-by-one after
each barrier completion from blk_ordered_complete_seq().
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
---
block/blk-barrier.c | 220 ++++++++++++++++++---------------------------
block/blk-core.c | 11 ++-
block/blk.h | 2 +-
block/elevator.c | 79 ++--------------
include/linux/blk_types.h | 2 -
include/linux/blkdev.h | 19 ++---
6 files changed, 113 insertions(+), 220 deletions(-)
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index f1be85b..e8b2e5c 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -9,6 +9,8 @@
#include "blk.h"
+static struct request *queue_next_ordseq(struct request_queue *q);
+
/*
* Cache flushing for ordered writes handling
*/
@@ -19,38 +21,10 @@ unsigned blk_ordered_cur_seq(struct request_queue *q)
return 1 << ffz(q->ordseq);
}
-unsigned blk_ordered_req_seq(struct request *rq)
-{
- struct request_queue *q = rq->q;
-
- BUG_ON(q->ordseq == 0);
-
- if (rq == &q->pre_flush_rq)
- return QUEUE_ORDSEQ_PREFLUSH;
- if (rq == &q->bar_rq)
- return QUEUE_ORDSEQ_BAR;
- if (rq == &q->post_flush_rq)
- return QUEUE_ORDSEQ_POSTFLUSH;
-
- /*
- * !fs requests don't need to follow barrier ordering. Always
- * put them at the front. This fixes the following deadlock.
- *
- * http://thread.gmane.org/gmane.linux.kernel/537473
- */
- if (rq->cmd_type != REQ_TYPE_FS)
- return QUEUE_ORDSEQ_DRAIN;
-
- if ((rq->cmd_flags & REQ_ORDERED_COLOR) ==
- (q->orig_bar_rq->cmd_flags & REQ_ORDERED_COLOR))
- return QUEUE_ORDSEQ_DRAIN;
- else
- return QUEUE_ORDSEQ_DONE;
-}
-
-bool blk_ordered_complete_seq(struct request_queue *q, unsigned seq, int error)
+static struct request *blk_ordered_complete_seq(struct request_queue *q,
+ unsigned seq, int error)
{
- struct request *rq;
+ struct request *next_rq = NULL;
if (error && !q->orderr)
q->orderr = error;
@@ -58,16 +32,22 @@ bool blk_ordered_complete_seq(struct request_queue *q, unsigned seq, int error)
BUG_ON(q->ordseq & seq);
q->ordseq |= seq;
- if (blk_ordered_cur_seq(q) != QUEUE_ORDSEQ_DONE)
- return false;
-
- /*
- * Okay, sequence complete.
- */
- q->ordseq = 0;
- rq = q->orig_bar_rq;
- __blk_end_request_all(rq, q->orderr);
- return true;
+ if (blk_ordered_cur_seq(q) != QUEUE_ORDSEQ_DONE) {
+ /* not complete yet, queue the next ordered sequence */
+ next_rq = queue_next_ordseq(q);
+ } else {
+ /* complete this barrier request */
+ __blk_end_request_all(q->orig_bar_rq, q->orderr);
+ q->orig_bar_rq = NULL;
+ q->ordseq = 0;
+
+ /* dispatch the next barrier if there's one */
+ if (!list_empty(&q->pending_barriers)) {
+ next_rq = list_entry_rq(q->pending_barriers.next);
+ list_move(&next_rq->queuelist, &q->queue_head);
+ }
+ }
+ return next_rq;
}
static void pre_flush_end_io(struct request *rq, int error)
@@ -88,133 +68,105 @@ static void post_flush_end_io(struct request *rq, int error)
blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_POSTFLUSH, error);
}
-static void queue_flush(struct request_queue *q, unsigned which)
+static void queue_flush(struct request_queue *q, struct request *rq,
+ rq_end_io_fn *end_io)
{
- struct request *rq;
- rq_end_io_fn *end_io;
-
- if (which == QUEUE_ORDERED_DO_PREFLUSH) {
- rq = &q->pre_flush_rq;
- end_io = pre_flush_end_io;
- } else {
- rq = &q->post_flush_rq;
- end_io = post_flush_end_io;
- }
-
blk_rq_init(q, rq);
rq->cmd_type = REQ_TYPE_FS;
- rq->cmd_flags = REQ_HARDBARRIER | REQ_FLUSH;
+ rq->cmd_flags = REQ_FLUSH;
rq->rq_disk = q->orig_bar_rq->rq_disk;
rq->end_io = end_io;
elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
}
-static inline struct request *start_ordered(struct request_queue *q,
- struct request *rq)
+static struct request *queue_next_ordseq(struct request_queue *q)
{
- unsigned skip = 0;
-
- q->orderr = 0;
- q->ordered = q->next_ordered;
- q->ordseq |= QUEUE_ORDSEQ_STARTED;
-
- /*
- * For an empty barrier, there's no actual BAR request, which
- * in turn makes POSTFLUSH unnecessary. Mask them off.
- */
- if (!blk_rq_sectors(rq))
- q->ordered &= ~(QUEUE_ORDERED_DO_BAR |
- QUEUE_ORDERED_DO_POSTFLUSH);
-
- /* stash away the original request */
- blk_dequeue_request(rq);
- q->orig_bar_rq = rq;
- rq = NULL;
-
- /*
- * Queue ordered sequence. As we stack them at the head, we
- * need to queue in reverse order. Note that we rely on that
- * no fs request uses ELEVATOR_INSERT_FRONT and thus no fs
- * request gets inbetween ordered sequence.
- */
- if (q->ordered & QUEUE_ORDERED_DO_POSTFLUSH) {
- queue_flush(q, QUEUE_ORDERED_DO_POSTFLUSH);
- rq = &q->post_flush_rq;
- } else
- skip |= QUEUE_ORDSEQ_POSTFLUSH;
+ struct request *rq = &q->bar_rq;
- if (q->ordered & QUEUE_ORDERED_DO_BAR) {
- rq = &q->bar_rq;
+ switch (blk_ordered_cur_seq(q)) {
+ case QUEUE_ORDSEQ_PREFLUSH:
+ queue_flush(q, rq, pre_flush_end_io);
+ break;
+ case QUEUE_ORDSEQ_BAR:
/* initialize proxy request and queue it */
blk_rq_init(q, rq);
init_request_from_bio(rq, q->orig_bar_rq->bio);
+ rq->cmd_flags &= ~REQ_HARDBARRIER;
if (q->ordered & QUEUE_ORDERED_DO_FUA)
rq->cmd_flags |= REQ_FUA;
rq->end_io = bar_end_io;
elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
- } else
- skip |= QUEUE_ORDSEQ_BAR;
+ break;
- if (q->ordered & QUEUE_ORDERED_DO_PREFLUSH) {
- queue_flush(q, QUEUE_ORDERED_DO_PREFLUSH);
- rq = &q->pre_flush_rq;
- } else
- skip |= QUEUE_ORDSEQ_PREFLUSH;
+ case QUEUE_ORDSEQ_POSTFLUSH:
+ queue_flush(q, rq, post_flush_end_io);
+ break;
- if (queue_in_flight(q))
- rq = NULL;
- else
- skip |= QUEUE_ORDSEQ_DRAIN;
-
- /*
- * Complete skipped sequences. If whole sequence is complete,
- * return %NULL to tell elevator that this request is gone.
- */
- if (blk_ordered_complete_seq(q, skip, 0))
- rq = NULL;
+ default:
+ BUG();
+ }
return rq;
}
struct request *blk_do_ordered(struct request_queue *q, struct request *rq)
{
- const int is_barrier = rq->cmd_type == REQ_TYPE_FS &&
- (rq->cmd_flags & REQ_HARDBARRIER);
-
- if (!q->ordseq) {
- if (!is_barrier)
- return rq;
-
- if (q->next_ordered != QUEUE_ORDERED_NONE)
- return start_ordered(q, rq);
- else {
- /*
- * Queue ordering not supported. Terminate
- * with prejudice.
- */
- blk_dequeue_request(rq);
- __blk_end_request_all(rq, -EOPNOTSUPP);
- return NULL;
- }
+ unsigned skip = 0;
+
+ if (!(rq->cmd_flags & REQ_HARDBARRIER))
+ return rq;
+
+ if (q->ordseq) {
+ /*
+ * Barrier is already in progress and they can't be
+ * processed in parallel. Queue for later processing.
+ */
+ list_move_tail(&rq->queuelist, &q->pending_barriers);
+ return NULL;
+ }
+
+ if (unlikely(q->next_ordered == QUEUE_ORDERED_NONE)) {
+ /*
+ * Queue ordering not supported. Terminate
+ * with prejudice.
+ */
+ blk_dequeue_request(rq);
+ __blk_end_request_all(rq, -EOPNOTSUPP);
+ return NULL;
}
/*
- * Ordered sequence in progress
+ * Start a new ordered sequence
*/
+ q->orderr = 0;
+ q->ordered = q->next_ordered;
+ q->ordseq |= QUEUE_ORDSEQ_STARTED;
- /* Special requests are not subject to ordering rules. */
- if (rq->cmd_type != REQ_TYPE_FS &&
- rq != &q->pre_flush_rq && rq != &q->post_flush_rq)
- return rq;
+ /*
+ * For an empty barrier, there's no actual BAR request, which
+ * in turn makes POSTFLUSH unnecessary. Mask them off.
+ */
+ if (!blk_rq_sectors(rq))
+ q->ordered &= ~(QUEUE_ORDERED_DO_BAR |
+ QUEUE_ORDERED_DO_POSTFLUSH);
- /* Ordered by draining. Wait for turn. */
- WARN_ON(blk_ordered_req_seq(rq) < blk_ordered_cur_seq(q));
- if (blk_ordered_req_seq(rq) > blk_ordered_cur_seq(q))
- rq = ERR_PTR(-EAGAIN);
+ /* stash away the original request */
+ blk_dequeue_request(rq);
+ q->orig_bar_rq = rq;
- return rq;
+ if (!(q->ordered & QUEUE_ORDERED_DO_PREFLUSH))
+ skip |= QUEUE_ORDSEQ_PREFLUSH;
+
+ if (!(q->ordered & QUEUE_ORDERED_DO_BAR))
+ skip |= QUEUE_ORDSEQ_BAR;
+
+ if (!(q->ordered & QUEUE_ORDERED_DO_POSTFLUSH))
+ skip |= QUEUE_ORDSEQ_POSTFLUSH;
+
+ /* complete skipped sequences and return the first sequence */
+ return blk_ordered_complete_seq(q, skip, 0);
}
static void bio_end_empty_barrier(struct bio *bio, int err)
diff --git a/block/blk-core.c b/block/blk-core.c
index f8d37a8..d316662 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -520,6 +520,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
init_timer(&q->unplug_timer);
setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q);
INIT_LIST_HEAD(&q->timeout_list);
+ INIT_LIST_HEAD(&q->pending_barriers);
INIT_WORK(&q->unplug_work, blk_unplug_work);
kobject_init(&q->kobj, &blk_queue_ktype);
@@ -1185,6 +1186,7 @@ static int __make_request(struct request_queue *q, struct bio *bio)
const bool sync = (bio->bi_rw & REQ_SYNC);
const bool unplug = (bio->bi_rw & REQ_UNPLUG);
const unsigned int ff = bio->bi_rw & REQ_FAILFAST_MASK;
+ int where = ELEVATOR_INSERT_SORT;
int rw_flags;
/* REQ_HARDBARRIER is no more */
@@ -1203,7 +1205,12 @@ static int __make_request(struct request_queue *q, struct bio *bio)
spin_lock_irq(q->queue_lock);
- if (unlikely((bio->bi_rw & REQ_HARDBARRIER)) || elv_queue_empty(q))
+ if (bio->bi_rw & REQ_HARDBARRIER) {
+ where = ELEVATOR_INSERT_FRONT;
+ goto get_rq;
+ }
+
+ if (elv_queue_empty(q))
goto get_rq;
el_ret = elv_merge(q, &req, bio);
@@ -1303,7 +1310,7 @@ get_rq:
/* insert the request into the elevator */
drive_stat_acct(req, 1);
- __elv_add_request(q, req, ELEVATOR_INSERT_SORT, 0);
+ __elv_add_request(q, req, where, 0);
out:
if (unplug || !queue_should_plug(q))
__generic_unplug_device(q);
diff --git a/block/blk.h b/block/blk.h
index 874eb4e..08081e4 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -62,7 +62,7 @@ static inline struct request *__elv_next_request(struct request_queue *q)
rq = list_entry_rq(q->queue_head.next);
rq = blk_do_ordered(q, rq);
if (rq)
- return !IS_ERR(rq) ? rq : NULL;
+ return rq;
}
if (!q->elevator->ops->elevator_dispatch_fn(q, 0))
diff --git a/block/elevator.c b/block/elevator.c
index ec585c9..241c69c 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -617,8 +617,6 @@ void elv_quiesce_end(struct request_queue *q)
void elv_insert(struct request_queue *q, struct request *rq, int where)
{
- struct list_head *pos;
- unsigned ordseq;
int unplug_it = 1;
trace_block_rq_insert(q, rq);
@@ -626,9 +624,16 @@ void elv_insert(struct request_queue *q, struct request *rq, int where)
rq->q = q;
switch (where) {
+ case ELEVATOR_INSERT_REQUEUE:
+ /*
+ * Most requeues happen because of a busy condition,
+ * don't force unplug of the queue for that case.
+ * Clear unplug_it and fall through.
+ */
+ unplug_it = 0;
+
case ELEVATOR_INSERT_FRONT:
rq->cmd_flags |= REQ_SOFTBARRIER;
-
list_add(&rq->queuelist, &q->queue_head);
break;
@@ -668,36 +673,6 @@ void elv_insert(struct request_queue *q, struct request *rq, int where)
q->elevator->ops->elevator_add_req_fn(q, rq);
break;
- case ELEVATOR_INSERT_REQUEUE:
- /*
- * If ordered flush isn't in progress, we do front
- * insertion; otherwise, requests should be requeued
- * in ordseq order.
- */
- rq->cmd_flags |= REQ_SOFTBARRIER;
-
- /*
- * Most requeues happen because of a busy condition,
- * don't force unplug of the queue for that case.
- */
- unplug_it = 0;
-
- if (q->ordseq == 0) {
- list_add(&rq->queuelist, &q->queue_head);
- break;
- }
-
- ordseq = blk_ordered_req_seq(rq);
-
- list_for_each(pos, &q->queue_head) {
- struct request *pos_rq = list_entry_rq(pos);
- if (ordseq <= blk_ordered_req_seq(pos_rq))
- break;
- }
-
- list_add_tail(&rq->queuelist, pos);
- break;
-
default:
printk(KERN_ERR "%s: bad insertion point %d\n",
__func__, where);
@@ -716,26 +691,8 @@ void elv_insert(struct request_queue *q, struct request *rq, int where)
void __elv_add_request(struct request_queue *q, struct request *rq, int where,
int plug)
{
- if (q->ordcolor)
- rq->cmd_flags |= REQ_ORDERED_COLOR;
-
if (rq->cmd_flags & (REQ_SOFTBARRIER | REQ_HARDBARRIER)) {
- /*
- * toggle ordered color
- */
- if (rq->cmd_flags & REQ_HARDBARRIER)
- q->ordcolor ^= 1;
-
- /*
- * barriers implicitly indicate back insertion
- */
- if (where == ELEVATOR_INSERT_SORT)
- where = ELEVATOR_INSERT_BACK;
-
- /*
- * this request is scheduling boundary, update
- * end_sector
- */
+ /* barriers are scheduling boundary, update end_sector */
if (rq->cmd_type == REQ_TYPE_FS ||
(rq->cmd_flags & REQ_DISCARD)) {
q->end_sector = rq_end_sector(rq);
@@ -855,24 +812,6 @@ void elv_completed_request(struct request_queue *q, struct request *rq)
e->ops->elevator_completed_req_fn)
e->ops->elevator_completed_req_fn(q, rq);
}
-
- /*
- * Check if the queue is waiting for fs requests to be
- * drained for flush sequence.
- */
- if (unlikely(q->ordseq)) {
- struct request *next = NULL;
-
- if (!list_empty(&q->queue_head))
- next = list_entry_rq(q->queue_head.next);
-
- if (!queue_in_flight(q) &&
- blk_ordered_cur_seq(q) == QUEUE_ORDSEQ_DRAIN &&
- (!next || blk_ordered_req_seq(next) > QUEUE_ORDSEQ_DRAIN)) {
- blk_ordered_complete_seq(q, QUEUE_ORDSEQ_DRAIN, 0);
- __blk_run_queue(q);
- }
- }
}
#define to_elv(atr) container_of((atr), struct elv_fs_entry, attr)
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index ca83a97..9192282 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -143,7 +143,6 @@ enum rq_flag_bits {
__REQ_FAILED, /* set if the request failed */
__REQ_QUIET, /* don't worry about errors */
__REQ_PREEMPT, /* set for "ide_preempt" requests */
- __REQ_ORDERED_COLOR, /* is before or after barrier */
__REQ_ALLOCED, /* request came from our alloc pool */
__REQ_COPY_USER, /* contains copies of user pages */
__REQ_INTEGRITY, /* integrity metadata has been remapped */
@@ -184,7 +183,6 @@ enum rq_flag_bits {
#define REQ_FAILED (1 << __REQ_FAILED)
#define REQ_QUIET (1 << __REQ_QUIET)
#define REQ_PREEMPT (1 << __REQ_PREEMPT)
-#define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
#define REQ_ALLOCED (1 << __REQ_ALLOCED)
#define REQ_COPY_USER (1 << __REQ_COPY_USER)
#define REQ_INTEGRITY (1 << __REQ_INTEGRITY)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 996549d..20a3710 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -360,9 +360,10 @@ struct request_queue
unsigned int flush_flags;
unsigned int ordered, next_ordered, ordseq;
- int orderr, ordcolor;
- struct request pre_flush_rq, bar_rq, post_flush_rq;
+ int orderr;
+ struct request bar_rq;
struct request *orig_bar_rq;
+ struct list_head pending_barriers;
struct mutex sysfs_lock;
@@ -491,12 +492,11 @@ enum {
/*
* Ordered operation sequence
*/
- QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */
- QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */
- QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */
- QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */
- QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */
- QUEUE_ORDSEQ_DONE = 0x20,
+ QUEUE_ORDSEQ_STARTED = (1 << 0), /* flushing in progress */
+ QUEUE_ORDSEQ_PREFLUSH = (1 << 1), /* pre-flushing in progress */
+ QUEUE_ORDSEQ_BAR = (1 << 2), /* barrier write in progress */
+ QUEUE_ORDSEQ_POSTFLUSH = (1 << 3), /* post-flushing in progress */
+ QUEUE_ORDSEQ_DONE = (1 << 4),
};
#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
@@ -869,9 +869,6 @@ extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
-extern unsigned blk_ordered_cur_seq(struct request_queue *);
-extern unsigned blk_ordered_req_seq(struct request *);
-extern bool blk_ordered_complete_seq(struct request_queue *, unsigned, int);
extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
extern void blk_dump_rq_flags(struct request *, char *);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 07/41] block: drop barrier ordering by queue draining
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo, Christoph Hellwig
Filesystems will take all the responsibilities for ordering requests
around commit writes and will only indicate how the commit writes
themselves should be handled by block layers. This patch drops
barrier ordering by queue draining from block layer. Ordering by
draining implementation was somewhat invasive to request handling.
List of notable changes follow.
* Each queue has 1 bit color which is flipped on each barrier issue.
This is used to track whether a given request is issued before the
current barrier or not. REQ_ORDERED_COLOR flag and coloring
implementation in __elv_add_request() are removed.
* Requests which shouldn't be processed yet for draining were stalled
by returning -EAGAIN from blk_do_ordered() according to the test
result between blk_ordered_req_seq() and blk_blk_ordered_cur_seq().
This logic is removed.
* Draining completion logic in elv_completed_request() removed.
* All barrier sequence requests were queued to request queue and then
trckled to lower layer according to progress and thus maintaining
request orders during requeue was necessary. This is replaced by
queueing the next request in the barrier sequence only after the
current one is complete from blk_ordered_complete_seq(), which
removes the need for multiple proxy requests in struct request_queue
and the request sorting logic in the ELEVATOR_INSERT_REQUEUE path of
elv_insert().
* As barriers no longer have ordering constraints, there's no need to
dump the whole elevator onto the dispatch queue on each barrier.
Insert barriers at the front instead.
* If other barrier requests come to the front of the dispatch queue
while one is already in progress, they are stored in
q->pending_barriers and restored to dispatch queue one-by-one after
each barrier completion from blk_ordered_complete_seq().
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
---
block/blk-barrier.c | 220 ++++++++++++++++++---------------------------
block/blk-core.c | 11 ++-
block/blk.h | 2 +-
block/elevator.c | 79 ++--------------
include/linux/blk_types.h | 2 -
include/linux/blkdev.h | 19 ++---
6 files changed, 113 insertions(+), 220 deletions(-)
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index f1be85b..e8b2e5c 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -9,6 +9,8 @@
#include "blk.h"
+static struct request *queue_next_ordseq(struct request_queue *q);
+
/*
* Cache flushing for ordered writes handling
*/
@@ -19,38 +21,10 @@ unsigned blk_ordered_cur_seq(struct request_queue *q)
return 1 << ffz(q->ordseq);
}
-unsigned blk_ordered_req_seq(struct request *rq)
-{
- struct request_queue *q = rq->q;
-
- BUG_ON(q->ordseq == 0);
-
- if (rq == &q->pre_flush_rq)
- return QUEUE_ORDSEQ_PREFLUSH;
- if (rq == &q->bar_rq)
- return QUEUE_ORDSEQ_BAR;
- if (rq == &q->post_flush_rq)
- return QUEUE_ORDSEQ_POSTFLUSH;
-
- /*
- * !fs requests don't need to follow barrier ordering. Always
- * put them at the front. This fixes the following deadlock.
- *
- * http://thread.gmane.org/gmane.linux.kernel/537473
- */
- if (rq->cmd_type != REQ_TYPE_FS)
- return QUEUE_ORDSEQ_DRAIN;
-
- if ((rq->cmd_flags & REQ_ORDERED_COLOR) ==
- (q->orig_bar_rq->cmd_flags & REQ_ORDERED_COLOR))
- return QUEUE_ORDSEQ_DRAIN;
- else
- return QUEUE_ORDSEQ_DONE;
-}
-
-bool blk_ordered_complete_seq(struct request_queue *q, unsigned seq, int error)
+static struct request *blk_ordered_complete_seq(struct request_queue *q,
+ unsigned seq, int error)
{
- struct request *rq;
+ struct request *next_rq = NULL;
if (error && !q->orderr)
q->orderr = error;
@@ -58,16 +32,22 @@ bool blk_ordered_complete_seq(struct request_queue *q, unsigned seq, int error)
BUG_ON(q->ordseq & seq);
q->ordseq |= seq;
- if (blk_ordered_cur_seq(q) != QUEUE_ORDSEQ_DONE)
- return false;
-
- /*
- * Okay, sequence complete.
- */
- q->ordseq = 0;
- rq = q->orig_bar_rq;
- __blk_end_request_all(rq, q->orderr);
- return true;
+ if (blk_ordered_cur_seq(q) != QUEUE_ORDSEQ_DONE) {
+ /* not complete yet, queue the next ordered sequence */
+ next_rq = queue_next_ordseq(q);
+ } else {
+ /* complete this barrier request */
+ __blk_end_request_all(q->orig_bar_rq, q->orderr);
+ q->orig_bar_rq = NULL;
+ q->ordseq = 0;
+
+ /* dispatch the next barrier if there's one */
+ if (!list_empty(&q->pending_barriers)) {
+ next_rq = list_entry_rq(q->pending_barriers.next);
+ list_move(&next_rq->queuelist, &q->queue_head);
+ }
+ }
+ return next_rq;
}
static void pre_flush_end_io(struct request *rq, int error)
@@ -88,133 +68,105 @@ static void post_flush_end_io(struct request *rq, int error)
blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_POSTFLUSH, error);
}
-static void queue_flush(struct request_queue *q, unsigned which)
+static void queue_flush(struct request_queue *q, struct request *rq,
+ rq_end_io_fn *end_io)
{
- struct request *rq;
- rq_end_io_fn *end_io;
-
- if (which == QUEUE_ORDERED_DO_PREFLUSH) {
- rq = &q->pre_flush_rq;
- end_io = pre_flush_end_io;
- } else {
- rq = &q->post_flush_rq;
- end_io = post_flush_end_io;
- }
-
blk_rq_init(q, rq);
rq->cmd_type = REQ_TYPE_FS;
- rq->cmd_flags = REQ_HARDBARRIER | REQ_FLUSH;
+ rq->cmd_flags = REQ_FLUSH;
rq->rq_disk = q->orig_bar_rq->rq_disk;
rq->end_io = end_io;
elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
}
-static inline struct request *start_ordered(struct request_queue *q,
- struct request *rq)
+static struct request *queue_next_ordseq(struct request_queue *q)
{
- unsigned skip = 0;
-
- q->orderr = 0;
- q->ordered = q->next_ordered;
- q->ordseq |= QUEUE_ORDSEQ_STARTED;
-
- /*
- * For an empty barrier, there's no actual BAR request, which
- * in turn makes POSTFLUSH unnecessary. Mask them off.
- */
- if (!blk_rq_sectors(rq))
- q->ordered &= ~(QUEUE_ORDERED_DO_BAR |
- QUEUE_ORDERED_DO_POSTFLUSH);
-
- /* stash away the original request */
- blk_dequeue_request(rq);
- q->orig_bar_rq = rq;
- rq = NULL;
-
- /*
- * Queue ordered sequence. As we stack them at the head, we
- * need to queue in reverse order. Note that we rely on that
- * no fs request uses ELEVATOR_INSERT_FRONT and thus no fs
- * request gets inbetween ordered sequence.
- */
- if (q->ordered & QUEUE_ORDERED_DO_POSTFLUSH) {
- queue_flush(q, QUEUE_ORDERED_DO_POSTFLUSH);
- rq = &q->post_flush_rq;
- } else
- skip |= QUEUE_ORDSEQ_POSTFLUSH;
+ struct request *rq = &q->bar_rq;
- if (q->ordered & QUEUE_ORDERED_DO_BAR) {
- rq = &q->bar_rq;
+ switch (blk_ordered_cur_seq(q)) {
+ case QUEUE_ORDSEQ_PREFLUSH:
+ queue_flush(q, rq, pre_flush_end_io);
+ break;
+ case QUEUE_ORDSEQ_BAR:
/* initialize proxy request and queue it */
blk_rq_init(q, rq);
init_request_from_bio(rq, q->orig_bar_rq->bio);
+ rq->cmd_flags &= ~REQ_HARDBARRIER;
if (q->ordered & QUEUE_ORDERED_DO_FUA)
rq->cmd_flags |= REQ_FUA;
rq->end_io = bar_end_io;
elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
- } else
- skip |= QUEUE_ORDSEQ_BAR;
+ break;
- if (q->ordered & QUEUE_ORDERED_DO_PREFLUSH) {
- queue_flush(q, QUEUE_ORDERED_DO_PREFLUSH);
- rq = &q->pre_flush_rq;
- } else
- skip |= QUEUE_ORDSEQ_PREFLUSH;
+ case QUEUE_ORDSEQ_POSTFLUSH:
+ queue_flush(q, rq, post_flush_end_io);
+ break;
- if (queue_in_flight(q))
- rq = NULL;
- else
- skip |= QUEUE_ORDSEQ_DRAIN;
-
- /*
- * Complete skipped sequences. If whole sequence is complete,
- * return %NULL to tell elevator that this request is gone.
- */
- if (blk_ordered_complete_seq(q, skip, 0))
- rq = NULL;
+ default:
+ BUG();
+ }
return rq;
}
struct request *blk_do_ordered(struct request_queue *q, struct request *rq)
{
- const int is_barrier = rq->cmd_type == REQ_TYPE_FS &&
- (rq->cmd_flags & REQ_HARDBARRIER);
-
- if (!q->ordseq) {
- if (!is_barrier)
- return rq;
-
- if (q->next_ordered != QUEUE_ORDERED_NONE)
- return start_ordered(q, rq);
- else {
- /*
- * Queue ordering not supported. Terminate
- * with prejudice.
- */
- blk_dequeue_request(rq);
- __blk_end_request_all(rq, -EOPNOTSUPP);
- return NULL;
- }
+ unsigned skip = 0;
+
+ if (!(rq->cmd_flags & REQ_HARDBARRIER))
+ return rq;
+
+ if (q->ordseq) {
+ /*
+ * Barrier is already in progress and they can't be
+ * processed in parallel. Queue for later processing.
+ */
+ list_move_tail(&rq->queuelist, &q->pending_barriers);
+ return NULL;
+ }
+
+ if (unlikely(q->next_ordered == QUEUE_ORDERED_NONE)) {
+ /*
+ * Queue ordering not supported. Terminate
+ * with prejudice.
+ */
+ blk_dequeue_request(rq);
+ __blk_end_request_all(rq, -EOPNOTSUPP);
+ return NULL;
}
/*
- * Ordered sequence in progress
+ * Start a new ordered sequence
*/
+ q->orderr = 0;
+ q->ordered = q->next_ordered;
+ q->ordseq |= QUEUE_ORDSEQ_STARTED;
- /* Special requests are not subject to ordering rules. */
- if (rq->cmd_type != REQ_TYPE_FS &&
- rq != &q->pre_flush_rq && rq != &q->post_flush_rq)
- return rq;
+ /*
+ * For an empty barrier, there's no actual BAR request, which
+ * in turn makes POSTFLUSH unnecessary. Mask them off.
+ */
+ if (!blk_rq_sectors(rq))
+ q->ordered &= ~(QUEUE_ORDERED_DO_BAR |
+ QUEUE_ORDERED_DO_POSTFLUSH);
- /* Ordered by draining. Wait for turn. */
- WARN_ON(blk_ordered_req_seq(rq) < blk_ordered_cur_seq(q));
- if (blk_ordered_req_seq(rq) > blk_ordered_cur_seq(q))
- rq = ERR_PTR(-EAGAIN);
+ /* stash away the original request */
+ blk_dequeue_request(rq);
+ q->orig_bar_rq = rq;
- return rq;
+ if (!(q->ordered & QUEUE_ORDERED_DO_PREFLUSH))
+ skip |= QUEUE_ORDSEQ_PREFLUSH;
+
+ if (!(q->ordered & QUEUE_ORDERED_DO_BAR))
+ skip |= QUEUE_ORDSEQ_BAR;
+
+ if (!(q->ordered & QUEUE_ORDERED_DO_POSTFLUSH))
+ skip |= QUEUE_ORDSEQ_POSTFLUSH;
+
+ /* complete skipped sequences and return the first sequence */
+ return blk_ordered_complete_seq(q, skip, 0);
}
static void bio_end_empty_barrier(struct bio *bio, int err)
diff --git a/block/blk-core.c b/block/blk-core.c
index f8d37a8..d316662 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -520,6 +520,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
init_timer(&q->unplug_timer);
setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q);
INIT_LIST_HEAD(&q->timeout_list);
+ INIT_LIST_HEAD(&q->pending_barriers);
INIT_WORK(&q->unplug_work, blk_unplug_work);
kobject_init(&q->kobj, &blk_queue_ktype);
@@ -1185,6 +1186,7 @@ static int __make_request(struct request_queue *q, struct bio *bio)
const bool sync = (bio->bi_rw & REQ_SYNC);
const bool unplug = (bio->bi_rw & REQ_UNPLUG);
const unsigned int ff = bio->bi_rw & REQ_FAILFAST_MASK;
+ int where = ELEVATOR_INSERT_SORT;
int rw_flags;
/* REQ_HARDBARRIER is no more */
@@ -1203,7 +1205,12 @@ static int __make_request(struct request_queue *q, struct bio *bio)
spin_lock_irq(q->queue_lock);
- if (unlikely((bio->bi_rw & REQ_HARDBARRIER)) || elv_queue_empty(q))
+ if (bio->bi_rw & REQ_HARDBARRIER) {
+ where = ELEVATOR_INSERT_FRONT;
+ goto get_rq;
+ }
+
+ if (elv_queue_empty(q))
goto get_rq;
el_ret = elv_merge(q, &req, bio);
@@ -1303,7 +1310,7 @@ get_rq:
/* insert the request into the elevator */
drive_stat_acct(req, 1);
- __elv_add_request(q, req, ELEVATOR_INSERT_SORT, 0);
+ __elv_add_request(q, req, where, 0);
out:
if (unplug || !queue_should_plug(q))
__generic_unplug_device(q);
diff --git a/block/blk.h b/block/blk.h
index 874eb4e..08081e4 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -62,7 +62,7 @@ static inline struct request *__elv_next_request(struct request_queue *q)
rq = list_entry_rq(q->queue_head.next);
rq = blk_do_ordered(q, rq);
if (rq)
- return !IS_ERR(rq) ? rq : NULL;
+ return rq;
}
if (!q->elevator->ops->elevator_dispatch_fn(q, 0))
diff --git a/block/elevator.c b/block/elevator.c
index ec585c9..241c69c 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -617,8 +617,6 @@ void elv_quiesce_end(struct request_queue *q)
void elv_insert(struct request_queue *q, struct request *rq, int where)
{
- struct list_head *pos;
- unsigned ordseq;
int unplug_it = 1;
trace_block_rq_insert(q, rq);
@@ -626,9 +624,16 @@ void elv_insert(struct request_queue *q, struct request *rq, int where)
rq->q = q;
switch (where) {
+ case ELEVATOR_INSERT_REQUEUE:
+ /*
+ * Most requeues happen because of a busy condition,
+ * don't force unplug of the queue for that case.
+ * Clear unplug_it and fall through.
+ */
+ unplug_it = 0;
+
case ELEVATOR_INSERT_FRONT:
rq->cmd_flags |= REQ_SOFTBARRIER;
-
list_add(&rq->queuelist, &q->queue_head);
break;
@@ -668,36 +673,6 @@ void elv_insert(struct request_queue *q, struct request *rq, int where)
q->elevator->ops->elevator_add_req_fn(q, rq);
break;
- case ELEVATOR_INSERT_REQUEUE:
- /*
- * If ordered flush isn't in progress, we do front
- * insertion; otherwise, requests should be requeued
- * in ordseq order.
- */
- rq->cmd_flags |= REQ_SOFTBARRIER;
-
- /*
- * Most requeues happen because of a busy condition,
- * don't force unplug of the queue for that case.
- */
- unplug_it = 0;
-
- if (q->ordseq == 0) {
- list_add(&rq->queuelist, &q->queue_head);
- break;
- }
-
- ordseq = blk_ordered_req_seq(rq);
-
- list_for_each(pos, &q->queue_head) {
- struct request *pos_rq = list_entry_rq(pos);
- if (ordseq <= blk_ordered_req_seq(pos_rq))
- break;
- }
-
- list_add_tail(&rq->queuelist, pos);
- break;
-
default:
printk(KERN_ERR "%s: bad insertion point %d\n",
__func__, where);
@@ -716,26 +691,8 @@ void elv_insert(struct request_queue *q, struct request *rq, int where)
void __elv_add_request(struct request_queue *q, struct request *rq, int where,
int plug)
{
- if (q->ordcolor)
- rq->cmd_flags |= REQ_ORDERED_COLOR;
-
if (rq->cmd_flags & (REQ_SOFTBARRIER | REQ_HARDBARRIER)) {
- /*
- * toggle ordered color
- */
- if (rq->cmd_flags & REQ_HARDBARRIER)
- q->ordcolor ^= 1;
-
- /*
- * barriers implicitly indicate back insertion
- */
- if (where == ELEVATOR_INSERT_SORT)
- where = ELEVATOR_INSERT_BACK;
-
- /*
- * this request is scheduling boundary, update
- * end_sector
- */
+ /* barriers are scheduling boundary, update end_sector */
if (rq->cmd_type == REQ_TYPE_FS ||
(rq->cmd_flags & REQ_DISCARD)) {
q->end_sector = rq_end_sector(rq);
@@ -855,24 +812,6 @@ void elv_completed_request(struct request_queue *q, struct request *rq)
e->ops->elevator_completed_req_fn)
e->ops->elevator_completed_req_fn(q, rq);
}
-
- /*
- * Check if the queue is waiting for fs requests to be
- * drained for flush sequence.
- */
- if (unlikely(q->ordseq)) {
- struct request *next = NULL;
-
- if (!list_empty(&q->queue_head))
- next = list_entry_rq(q->queue_head.next);
-
- if (!queue_in_flight(q) &&
- blk_ordered_cur_seq(q) == QUEUE_ORDSEQ_DRAIN &&
- (!next || blk_ordered_req_seq(next) > QUEUE_ORDSEQ_DRAIN)) {
- blk_ordered_complete_seq(q, QUEUE_ORDSEQ_DRAIN, 0);
- __blk_run_queue(q);
- }
- }
}
#define to_elv(atr) container_of((atr), struct elv_fs_entry, attr)
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index ca83a97..9192282 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -143,7 +143,6 @@ enum rq_flag_bits {
__REQ_FAILED, /* set if the request failed */
__REQ_QUIET, /* don't worry about errors */
__REQ_PREEMPT, /* set for "ide_preempt" requests */
- __REQ_ORDERED_COLOR, /* is before or after barrier */
__REQ_ALLOCED, /* request came from our alloc pool */
__REQ_COPY_USER, /* contains copies of user pages */
__REQ_INTEGRITY, /* integrity metadata has been remapped */
@@ -184,7 +183,6 @@ enum rq_flag_bits {
#define REQ_FAILED (1 << __REQ_FAILED)
#define REQ_QUIET (1 << __REQ_QUIET)
#define REQ_PREEMPT (1 << __REQ_PREEMPT)
-#define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
#define REQ_ALLOCED (1 << __REQ_ALLOCED)
#define REQ_COPY_USER (1 << __REQ_COPY_USER)
#define REQ_INTEGRITY (1 << __REQ_INTEGRITY)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 996549d..20a3710 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -360,9 +360,10 @@ struct request_queue
unsigned int flush_flags;
unsigned int ordered, next_ordered, ordseq;
- int orderr, ordcolor;
- struct request pre_flush_rq, bar_rq, post_flush_rq;
+ int orderr;
+ struct request bar_rq;
struct request *orig_bar_rq;
+ struct list_head pending_barriers;
struct mutex sysfs_lock;
@@ -491,12 +492,11 @@ enum {
/*
* Ordered operation sequence
*/
- QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */
- QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */
- QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */
- QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */
- QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */
- QUEUE_ORDSEQ_DONE = 0x20,
+ QUEUE_ORDSEQ_STARTED = (1 << 0), /* flushing in progress */
+ QUEUE_ORDSEQ_PREFLUSH = (1 << 1), /* pre-flushing in progress */
+ QUEUE_ORDSEQ_BAR = (1 << 2), /* barrier write in progress */
+ QUEUE_ORDSEQ_POSTFLUSH = (1 << 3), /* post-flushing in progress */
+ QUEUE_ORDSEQ_DONE = (1 << 4),
};
#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
@@ -869,9 +869,6 @@ extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
-extern unsigned blk_ordered_cur_seq(struct request_queue *);
-extern unsigned blk_ordered_req_seq(struct request *);
-extern bool blk_ordered_complete_seq(struct request_queue *, unsigned, int);
extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
extern void blk_dump_rq_flags(struct request *, char *);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 07/41] block: drop barrier ordering by queue draining
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo, Christoph Hellwig
Filesystems will take all the responsibilities for ordering requests
around commit writes and will only indicate how the commit writes
themselves should be handled by block layers. This patch drops
barrier ordering by queue draining from block layer. Ordering by
draining implementation was somewhat invasive to request handling.
List of notable changes follow.
* Each queue has 1 bit color which is flipped on each barrier issue.
This is used to track whether a given request is issued before the
current barrier or not. REQ_ORDERED_COLOR flag and coloring
implementation in __elv_add_request() are removed.
* Requests which shouldn't be processed yet for draining were stalled
by returning -EAGAIN from blk_do_ordered() according to the test
result between blk_ordered_req_seq() and blk_blk_ordered_cur_seq().
This logic is removed.
* Draining completion logic in elv_completed_request() removed.
* All barrier sequence requests were queued to request queue and then
trckled to lower layer according to progress and thus maintaining
request orders during requeue was necessary. This is replaced by
queueing the next request in the barrier sequence only after the
current one is complete from blk_ordered_complete_seq(), which
removes the need for multiple proxy requests in struct request_queue
and the request sorting logic in the ELEVATOR_INSERT_REQUEUE path of
elv_insert().
* As barriers no longer have ordering constraints, there's no need to
dump the whole elevator onto the dispatch queue on each barrier.
Insert barriers at the front instead.
* If other barrier requests come to the front of the dispatch queue
while one is already in progress, they are stored in
q->pending_barriers and restored to dispatch queue one-by-one after
each barrier completion from blk_ordered_complete_seq().
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
---
block/blk-barrier.c | 220 ++++++++++++++++++---------------------------
block/blk-core.c | 11 ++-
block/blk.h | 2 +-
block/elevator.c | 79 ++--------------
include/linux/blk_types.h | 2 -
include/linux/blkdev.h | 19 ++---
6 files changed, 113 insertions(+), 220 deletions(-)
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index f1be85b..e8b2e5c 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -9,6 +9,8 @@
#include "blk.h"
+static struct request *queue_next_ordseq(struct request_queue *q);
+
/*
* Cache flushing for ordered writes handling
*/
@@ -19,38 +21,10 @@ unsigned blk_ordered_cur_seq(struct request_queue *q)
return 1 << ffz(q->ordseq);
}
-unsigned blk_ordered_req_seq(struct request *rq)
-{
- struct request_queue *q = rq->q;
-
- BUG_ON(q->ordseq == 0);
-
- if (rq == &q->pre_flush_rq)
- return QUEUE_ORDSEQ_PREFLUSH;
- if (rq == &q->bar_rq)
- return QUEUE_ORDSEQ_BAR;
- if (rq == &q->post_flush_rq)
- return QUEUE_ORDSEQ_POSTFLUSH;
-
- /*
- * !fs requests don't need to follow barrier ordering. Always
- * put them at the front. This fixes the following deadlock.
- *
- * http://thread.gmane.org/gmane.linux.kernel/537473
- */
- if (rq->cmd_type != REQ_TYPE_FS)
- return QUEUE_ORDSEQ_DRAIN;
-
- if ((rq->cmd_flags & REQ_ORDERED_COLOR) ==
- (q->orig_bar_rq->cmd_flags & REQ_ORDERED_COLOR))
- return QUEUE_ORDSEQ_DRAIN;
- else
- return QUEUE_ORDSEQ_DONE;
-}
-
-bool blk_ordered_complete_seq(struct request_queue *q, unsigned seq, int error)
+static struct request *blk_ordered_complete_seq(struct request_queue *q,
+ unsigned seq, int error)
{
- struct request *rq;
+ struct request *next_rq = NULL;
if (error && !q->orderr)
q->orderr = error;
@@ -58,16 +32,22 @@ bool blk_ordered_complete_seq(struct request_queue *q, unsigned seq, int error)
BUG_ON(q->ordseq & seq);
q->ordseq |= seq;
- if (blk_ordered_cur_seq(q) != QUEUE_ORDSEQ_DONE)
- return false;
-
- /*
- * Okay, sequence complete.
- */
- q->ordseq = 0;
- rq = q->orig_bar_rq;
- __blk_end_request_all(rq, q->orderr);
- return true;
+ if (blk_ordered_cur_seq(q) != QUEUE_ORDSEQ_DONE) {
+ /* not complete yet, queue the next ordered sequence */
+ next_rq = queue_next_ordseq(q);
+ } else {
+ /* complete this barrier request */
+ __blk_end_request_all(q->orig_bar_rq, q->orderr);
+ q->orig_bar_rq = NULL;
+ q->ordseq = 0;
+
+ /* dispatch the next barrier if there's one */
+ if (!list_empty(&q->pending_barriers)) {
+ next_rq = list_entry_rq(q->pending_barriers.next);
+ list_move(&next_rq->queuelist, &q->queue_head);
+ }
+ }
+ return next_rq;
}
static void pre_flush_end_io(struct request *rq, int error)
@@ -88,133 +68,105 @@ static void post_flush_end_io(struct request *rq, int error)
blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_POSTFLUSH, error);
}
-static void queue_flush(struct request_queue *q, unsigned which)
+static void queue_flush(struct request_queue *q, struct request *rq,
+ rq_end_io_fn *end_io)
{
- struct request *rq;
- rq_end_io_fn *end_io;
-
- if (which == QUEUE_ORDERED_DO_PREFLUSH) {
- rq = &q->pre_flush_rq;
- end_io = pre_flush_end_io;
- } else {
- rq = &q->post_flush_rq;
- end_io = post_flush_end_io;
- }
-
blk_rq_init(q, rq);
rq->cmd_type = REQ_TYPE_FS;
- rq->cmd_flags = REQ_HARDBARRIER | REQ_FLUSH;
+ rq->cmd_flags = REQ_FLUSH;
rq->rq_disk = q->orig_bar_rq->rq_disk;
rq->end_io = end_io;
elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
}
-static inline struct request *start_ordered(struct request_queue *q,
- struct request *rq)
+static struct request *queue_next_ordseq(struct request_queue *q)
{
- unsigned skip = 0;
-
- q->orderr = 0;
- q->ordered = q->next_ordered;
- q->ordseq |= QUEUE_ORDSEQ_STARTED;
-
- /*
- * For an empty barrier, there's no actual BAR request, which
- * in turn makes POSTFLUSH unnecessary. Mask them off.
- */
- if (!blk_rq_sectors(rq))
- q->ordered &= ~(QUEUE_ORDERED_DO_BAR |
- QUEUE_ORDERED_DO_POSTFLUSH);
-
- /* stash away the original request */
- blk_dequeue_request(rq);
- q->orig_bar_rq = rq;
- rq = NULL;
-
- /*
- * Queue ordered sequence. As we stack them at the head, we
- * need to queue in reverse order. Note that we rely on that
- * no fs request uses ELEVATOR_INSERT_FRONT and thus no fs
- * request gets inbetween ordered sequence.
- */
- if (q->ordered & QUEUE_ORDERED_DO_POSTFLUSH) {
- queue_flush(q, QUEUE_ORDERED_DO_POSTFLUSH);
- rq = &q->post_flush_rq;
- } else
- skip |= QUEUE_ORDSEQ_POSTFLUSH;
+ struct request *rq = &q->bar_rq;
- if (q->ordered & QUEUE_ORDERED_DO_BAR) {
- rq = &q->bar_rq;
+ switch (blk_ordered_cur_seq(q)) {
+ case QUEUE_ORDSEQ_PREFLUSH:
+ queue_flush(q, rq, pre_flush_end_io);
+ break;
+ case QUEUE_ORDSEQ_BAR:
/* initialize proxy request and queue it */
blk_rq_init(q, rq);
init_request_from_bio(rq, q->orig_bar_rq->bio);
+ rq->cmd_flags &= ~REQ_HARDBARRIER;
if (q->ordered & QUEUE_ORDERED_DO_FUA)
rq->cmd_flags |= REQ_FUA;
rq->end_io = bar_end_io;
elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
- } else
- skip |= QUEUE_ORDSEQ_BAR;
+ break;
- if (q->ordered & QUEUE_ORDERED_DO_PREFLUSH) {
- queue_flush(q, QUEUE_ORDERED_DO_PREFLUSH);
- rq = &q->pre_flush_rq;
- } else
- skip |= QUEUE_ORDSEQ_PREFLUSH;
+ case QUEUE_ORDSEQ_POSTFLUSH:
+ queue_flush(q, rq, post_flush_end_io);
+ break;
- if (queue_in_flight(q))
- rq = NULL;
- else
- skip |= QUEUE_ORDSEQ_DRAIN;
-
- /*
- * Complete skipped sequences. If whole sequence is complete,
- * return %NULL to tell elevator that this request is gone.
- */
- if (blk_ordered_complete_seq(q, skip, 0))
- rq = NULL;
+ default:
+ BUG();
+ }
return rq;
}
struct request *blk_do_ordered(struct request_queue *q, struct request *rq)
{
- const int is_barrier = rq->cmd_type == REQ_TYPE_FS &&
- (rq->cmd_flags & REQ_HARDBARRIER);
-
- if (!q->ordseq) {
- if (!is_barrier)
- return rq;
-
- if (q->next_ordered != QUEUE_ORDERED_NONE)
- return start_ordered(q, rq);
- else {
- /*
- * Queue ordering not supported. Terminate
- * with prejudice.
- */
- blk_dequeue_request(rq);
- __blk_end_request_all(rq, -EOPNOTSUPP);
- return NULL;
- }
+ unsigned skip = 0;
+
+ if (!(rq->cmd_flags & REQ_HARDBARRIER))
+ return rq;
+
+ if (q->ordseq) {
+ /*
+ * Barrier is already in progress and they can't be
+ * processed in parallel. Queue for later processing.
+ */
+ list_move_tail(&rq->queuelist, &q->pending_barriers);
+ return NULL;
+ }
+
+ if (unlikely(q->next_ordered == QUEUE_ORDERED_NONE)) {
+ /*
+ * Queue ordering not supported. Terminate
+ * with prejudice.
+ */
+ blk_dequeue_request(rq);
+ __blk_end_request_all(rq, -EOPNOTSUPP);
+ return NULL;
}
/*
- * Ordered sequence in progress
+ * Start a new ordered sequence
*/
+ q->orderr = 0;
+ q->ordered = q->next_ordered;
+ q->ordseq |= QUEUE_ORDSEQ_STARTED;
- /* Special requests are not subject to ordering rules. */
- if (rq->cmd_type != REQ_TYPE_FS &&
- rq != &q->pre_flush_rq && rq != &q->post_flush_rq)
- return rq;
+ /*
+ * For an empty barrier, there's no actual BAR request, which
+ * in turn makes POSTFLUSH unnecessary. Mask them off.
+ */
+ if (!blk_rq_sectors(rq))
+ q->ordered &= ~(QUEUE_ORDERED_DO_BAR |
+ QUEUE_ORDERED_DO_POSTFLUSH);
- /* Ordered by draining. Wait for turn. */
- WARN_ON(blk_ordered_req_seq(rq) < blk_ordered_cur_seq(q));
- if (blk_ordered_req_seq(rq) > blk_ordered_cur_seq(q))
- rq = ERR_PTR(-EAGAIN);
+ /* stash away the original request */
+ blk_dequeue_request(rq);
+ q->orig_bar_rq = rq;
- return rq;
+ if (!(q->ordered & QUEUE_ORDERED_DO_PREFLUSH))
+ skip |= QUEUE_ORDSEQ_PREFLUSH;
+
+ if (!(q->ordered & QUEUE_ORDERED_DO_BAR))
+ skip |= QUEUE_ORDSEQ_BAR;
+
+ if (!(q->ordered & QUEUE_ORDERED_DO_POSTFLUSH))
+ skip |= QUEUE_ORDSEQ_POSTFLUSH;
+
+ /* complete skipped sequences and return the first sequence */
+ return blk_ordered_complete_seq(q, skip, 0);
}
static void bio_end_empty_barrier(struct bio *bio, int err)
diff --git a/block/blk-core.c b/block/blk-core.c
index f8d37a8..d316662 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -520,6 +520,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
init_timer(&q->unplug_timer);
setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q);
INIT_LIST_HEAD(&q->timeout_list);
+ INIT_LIST_HEAD(&q->pending_barriers);
INIT_WORK(&q->unplug_work, blk_unplug_work);
kobject_init(&q->kobj, &blk_queue_ktype);
@@ -1185,6 +1186,7 @@ static int __make_request(struct request_queue *q, struct bio *bio)
const bool sync = (bio->bi_rw & REQ_SYNC);
const bool unplug = (bio->bi_rw & REQ_UNPLUG);
const unsigned int ff = bio->bi_rw & REQ_FAILFAST_MASK;
+ int where = ELEVATOR_INSERT_SORT;
int rw_flags;
/* REQ_HARDBARRIER is no more */
@@ -1203,7 +1205,12 @@ static int __make_request(struct request_queue *q, struct bio *bio)
spin_lock_irq(q->queue_lock);
- if (unlikely((bio->bi_rw & REQ_HARDBARRIER)) || elv_queue_empty(q))
+ if (bio->bi_rw & REQ_HARDBARRIER) {
+ where = ELEVATOR_INSERT_FRONT;
+ goto get_rq;
+ }
+
+ if (elv_queue_empty(q))
goto get_rq;
el_ret = elv_merge(q, &req, bio);
@@ -1303,7 +1310,7 @@ get_rq:
/* insert the request into the elevator */
drive_stat_acct(req, 1);
- __elv_add_request(q, req, ELEVATOR_INSERT_SORT, 0);
+ __elv_add_request(q, req, where, 0);
out:
if (unplug || !queue_should_plug(q))
__generic_unplug_device(q);
diff --git a/block/blk.h b/block/blk.h
index 874eb4e..08081e4 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -62,7 +62,7 @@ static inline struct request *__elv_next_request(struct request_queue *q)
rq = list_entry_rq(q->queue_head.next);
rq = blk_do_ordered(q, rq);
if (rq)
- return !IS_ERR(rq) ? rq : NULL;
+ return rq;
}
if (!q->elevator->ops->elevator_dispatch_fn(q, 0))
diff --git a/block/elevator.c b/block/elevator.c
index ec585c9..241c69c 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -617,8 +617,6 @@ void elv_quiesce_end(struct request_queue *q)
void elv_insert(struct request_queue *q, struct request *rq, int where)
{
- struct list_head *pos;
- unsigned ordseq;
int unplug_it = 1;
trace_block_rq_insert(q, rq);
@@ -626,9 +624,16 @@ void elv_insert(struct request_queue *q, struct request *rq, int where)
rq->q = q;
switch (where) {
+ case ELEVATOR_INSERT_REQUEUE:
+ /*
+ * Most requeues happen because of a busy condition,
+ * don't force unplug of the queue for that case.
+ * Clear unplug_it and fall through.
+ */
+ unplug_it = 0;
+
case ELEVATOR_INSERT_FRONT:
rq->cmd_flags |= REQ_SOFTBARRIER;
-
list_add(&rq->queuelist, &q->queue_head);
break;
@@ -668,36 +673,6 @@ void elv_insert(struct request_queue *q, struct request *rq, int where)
q->elevator->ops->elevator_add_req_fn(q, rq);
break;
- case ELEVATOR_INSERT_REQUEUE:
- /*
- * If ordered flush isn't in progress, we do front
- * insertion; otherwise, requests should be requeued
- * in ordseq order.
- */
- rq->cmd_flags |= REQ_SOFTBARRIER;
-
- /*
- * Most requeues happen because of a busy condition,
- * don't force unplug of the queue for that case.
- */
- unplug_it = 0;
-
- if (q->ordseq == 0) {
- list_add(&rq->queuelist, &q->queue_head);
- break;
- }
-
- ordseq = blk_ordered_req_seq(rq);
-
- list_for_each(pos, &q->queue_head) {
- struct request *pos_rq = list_entry_rq(pos);
- if (ordseq <= blk_ordered_req_seq(pos_rq))
- break;
- }
-
- list_add_tail(&rq->queuelist, pos);
- break;
-
default:
printk(KERN_ERR "%s: bad insertion point %d\n",
__func__, where);
@@ -716,26 +691,8 @@ void elv_insert(struct request_queue *q, struct request *rq, int where)
void __elv_add_request(struct request_queue *q, struct request *rq, int where,
int plug)
{
- if (q->ordcolor)
- rq->cmd_flags |= REQ_ORDERED_COLOR;
-
if (rq->cmd_flags & (REQ_SOFTBARRIER | REQ_HARDBARRIER)) {
- /*
- * toggle ordered color
- */
- if (rq->cmd_flags & REQ_HARDBARRIER)
- q->ordcolor ^= 1;
-
- /*
- * barriers implicitly indicate back insertion
- */
- if (where == ELEVATOR_INSERT_SORT)
- where = ELEVATOR_INSERT_BACK;
-
- /*
- * this request is scheduling boundary, update
- * end_sector
- */
+ /* barriers are scheduling boundary, update end_sector */
if (rq->cmd_type == REQ_TYPE_FS ||
(rq->cmd_flags & REQ_DISCARD)) {
q->end_sector = rq_end_sector(rq);
@@ -855,24 +812,6 @@ void elv_completed_request(struct request_queue *q, struct request *rq)
e->ops->elevator_completed_req_fn)
e->ops->elevator_completed_req_fn(q, rq);
}
-
- /*
- * Check if the queue is waiting for fs requests to be
- * drained for flush sequence.
- */
- if (unlikely(q->ordseq)) {
- struct request *next = NULL;
-
- if (!list_empty(&q->queue_head))
- next = list_entry_rq(q->queue_head.next);
-
- if (!queue_in_flight(q) &&
- blk_ordered_cur_seq(q) == QUEUE_ORDSEQ_DRAIN &&
- (!next || blk_ordered_req_seq(next) > QUEUE_ORDSEQ_DRAIN)) {
- blk_ordered_complete_seq(q, QUEUE_ORDSEQ_DRAIN, 0);
- __blk_run_queue(q);
- }
- }
}
#define to_elv(atr) container_of((atr), struct elv_fs_entry, attr)
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index ca83a97..9192282 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -143,7 +143,6 @@ enum rq_flag_bits {
__REQ_FAILED, /* set if the request failed */
__REQ_QUIET, /* don't worry about errors */
__REQ_PREEMPT, /* set for "ide_preempt" requests */
- __REQ_ORDERED_COLOR, /* is before or after barrier */
__REQ_ALLOCED, /* request came from our alloc pool */
__REQ_COPY_USER, /* contains copies of user pages */
__REQ_INTEGRITY, /* integrity metadata has been remapped */
@@ -184,7 +183,6 @@ enum rq_flag_bits {
#define REQ_FAILED (1 << __REQ_FAILED)
#define REQ_QUIET (1 << __REQ_QUIET)
#define REQ_PREEMPT (1 << __REQ_PREEMPT)
-#define REQ_ORDERED_COLOR (1 << __REQ_ORDERED_COLOR)
#define REQ_ALLOCED (1 << __REQ_ALLOCED)
#define REQ_COPY_USER (1 << __REQ_COPY_USER)
#define REQ_INTEGRITY (1 << __REQ_INTEGRITY)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 996549d..20a3710 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -360,9 +360,10 @@ struct request_queue
unsigned int flush_flags;
unsigned int ordered, next_ordered, ordseq;
- int orderr, ordcolor;
- struct request pre_flush_rq, bar_rq, post_flush_rq;
+ int orderr;
+ struct request bar_rq;
struct request *orig_bar_rq;
+ struct list_head pending_barriers;
struct mutex sysfs_lock;
@@ -491,12 +492,11 @@ enum {
/*
* Ordered operation sequence
*/
- QUEUE_ORDSEQ_STARTED = 0x01, /* flushing in progress */
- QUEUE_ORDSEQ_DRAIN = 0x02, /* waiting for the queue to be drained */
- QUEUE_ORDSEQ_PREFLUSH = 0x04, /* pre-flushing in progress */
- QUEUE_ORDSEQ_BAR = 0x08, /* original barrier req in progress */
- QUEUE_ORDSEQ_POSTFLUSH = 0x10, /* post-flushing in progress */
- QUEUE_ORDSEQ_DONE = 0x20,
+ QUEUE_ORDSEQ_STARTED = (1 << 0), /* flushing in progress */
+ QUEUE_ORDSEQ_PREFLUSH = (1 << 1), /* pre-flushing in progress */
+ QUEUE_ORDSEQ_BAR = (1 << 2), /* barrier write in progress */
+ QUEUE_ORDSEQ_POSTFLUSH = (1 << 3), /* post-flushing in progress */
+ QUEUE_ORDSEQ_DONE = (1 << 4),
};
#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
@@ -869,9 +869,6 @@ extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
-extern unsigned blk_ordered_cur_seq(struct request_queue *);
-extern unsigned blk_ordered_req_seq(struct request *);
-extern bool blk_ordered_complete_seq(struct request_queue *, unsigned, int);
extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
extern void blk_dump_rq_flags(struct request *, char *);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 08/41] block: rename blk-barrier.c to blk-flush.c
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo, Christoph Hellwig
Without ordering requirements, barrier and ordering are minomers.
Rename block/blk-barrier.c to block/blk-flush.c. Rename of symbols
will follow.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
---
block/Makefile | 2 +-
block/blk-barrier.c | 248 ---------------------------------------------------
block/blk-flush.c | 248 +++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 249 insertions(+), 249 deletions(-)
delete mode 100644 block/blk-barrier.c
create mode 100644 block/blk-flush.c
diff --git a/block/Makefile b/block/Makefile
index 0bb499a..f627e4b 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -3,7 +3,7 @@
#
obj-$(CONFIG_BLOCK) := elevator.o blk-core.o blk-tag.o blk-sysfs.o \
- blk-barrier.o blk-settings.o blk-ioc.o blk-map.o \
+ blk-flush.o blk-settings.o blk-ioc.o blk-map.o \
blk-exec.o blk-merge.o blk-softirq.o blk-timeout.o \
blk-iopoll.o blk-lib.o ioctl.o genhd.o scsi_ioctl.o
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
deleted file mode 100644
index e8b2e5c..0000000
--- a/block/blk-barrier.c
+++ /dev/null
@@ -1,248 +0,0 @@
-/*
- * Functions related to barrier IO handling
- */
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/bio.h>
-#include <linux/blkdev.h>
-#include <linux/gfp.h>
-
-#include "blk.h"
-
-static struct request *queue_next_ordseq(struct request_queue *q);
-
-/*
- * Cache flushing for ordered writes handling
- */
-unsigned blk_ordered_cur_seq(struct request_queue *q)
-{
- if (!q->ordseq)
- return 0;
- return 1 << ffz(q->ordseq);
-}
-
-static struct request *blk_ordered_complete_seq(struct request_queue *q,
- unsigned seq, int error)
-{
- struct request *next_rq = NULL;
-
- if (error && !q->orderr)
- q->orderr = error;
-
- BUG_ON(q->ordseq & seq);
- q->ordseq |= seq;
-
- if (blk_ordered_cur_seq(q) != QUEUE_ORDSEQ_DONE) {
- /* not complete yet, queue the next ordered sequence */
- next_rq = queue_next_ordseq(q);
- } else {
- /* complete this barrier request */
- __blk_end_request_all(q->orig_bar_rq, q->orderr);
- q->orig_bar_rq = NULL;
- q->ordseq = 0;
-
- /* dispatch the next barrier if there's one */
- if (!list_empty(&q->pending_barriers)) {
- next_rq = list_entry_rq(q->pending_barriers.next);
- list_move(&next_rq->queuelist, &q->queue_head);
- }
- }
- return next_rq;
-}
-
-static void pre_flush_end_io(struct request *rq, int error)
-{
- elv_completed_request(rq->q, rq);
- blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_PREFLUSH, error);
-}
-
-static void bar_end_io(struct request *rq, int error)
-{
- elv_completed_request(rq->q, rq);
- blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_BAR, error);
-}
-
-static void post_flush_end_io(struct request *rq, int error)
-{
- elv_completed_request(rq->q, rq);
- blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_POSTFLUSH, error);
-}
-
-static void queue_flush(struct request_queue *q, struct request *rq,
- rq_end_io_fn *end_io)
-{
- blk_rq_init(q, rq);
- rq->cmd_type = REQ_TYPE_FS;
- rq->cmd_flags = REQ_FLUSH;
- rq->rq_disk = q->orig_bar_rq->rq_disk;
- rq->end_io = end_io;
-
- elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
-}
-
-static struct request *queue_next_ordseq(struct request_queue *q)
-{
- struct request *rq = &q->bar_rq;
-
- switch (blk_ordered_cur_seq(q)) {
- case QUEUE_ORDSEQ_PREFLUSH:
- queue_flush(q, rq, pre_flush_end_io);
- break;
-
- case QUEUE_ORDSEQ_BAR:
- /* initialize proxy request and queue it */
- blk_rq_init(q, rq);
- init_request_from_bio(rq, q->orig_bar_rq->bio);
- rq->cmd_flags &= ~REQ_HARDBARRIER;
- if (q->ordered & QUEUE_ORDERED_DO_FUA)
- rq->cmd_flags |= REQ_FUA;
- rq->end_io = bar_end_io;
-
- elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
- break;
-
- case QUEUE_ORDSEQ_POSTFLUSH:
- queue_flush(q, rq, post_flush_end_io);
- break;
-
- default:
- BUG();
- }
- return rq;
-}
-
-struct request *blk_do_ordered(struct request_queue *q, struct request *rq)
-{
- unsigned skip = 0;
-
- if (!(rq->cmd_flags & REQ_HARDBARRIER))
- return rq;
-
- if (q->ordseq) {
- /*
- * Barrier is already in progress and they can't be
- * processed in parallel. Queue for later processing.
- */
- list_move_tail(&rq->queuelist, &q->pending_barriers);
- return NULL;
- }
-
- if (unlikely(q->next_ordered == QUEUE_ORDERED_NONE)) {
- /*
- * Queue ordering not supported. Terminate
- * with prejudice.
- */
- blk_dequeue_request(rq);
- __blk_end_request_all(rq, -EOPNOTSUPP);
- return NULL;
- }
-
- /*
- * Start a new ordered sequence
- */
- q->orderr = 0;
- q->ordered = q->next_ordered;
- q->ordseq |= QUEUE_ORDSEQ_STARTED;
-
- /*
- * For an empty barrier, there's no actual BAR request, which
- * in turn makes POSTFLUSH unnecessary. Mask them off.
- */
- if (!blk_rq_sectors(rq))
- q->ordered &= ~(QUEUE_ORDERED_DO_BAR |
- QUEUE_ORDERED_DO_POSTFLUSH);
-
- /* stash away the original request */
- blk_dequeue_request(rq);
- q->orig_bar_rq = rq;
-
- if (!(q->ordered & QUEUE_ORDERED_DO_PREFLUSH))
- skip |= QUEUE_ORDSEQ_PREFLUSH;
-
- if (!(q->ordered & QUEUE_ORDERED_DO_BAR))
- skip |= QUEUE_ORDSEQ_BAR;
-
- if (!(q->ordered & QUEUE_ORDERED_DO_POSTFLUSH))
- skip |= QUEUE_ORDSEQ_POSTFLUSH;
-
- /* complete skipped sequences and return the first sequence */
- return blk_ordered_complete_seq(q, skip, 0);
-}
-
-static void bio_end_empty_barrier(struct bio *bio, int err)
-{
- if (err) {
- if (err == -EOPNOTSUPP)
- set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
- clear_bit(BIO_UPTODATE, &bio->bi_flags);
- }
- if (bio->bi_private)
- complete(bio->bi_private);
- bio_put(bio);
-}
-
-/**
- * blkdev_issue_flush - queue a flush
- * @bdev: blockdev to issue flush for
- * @gfp_mask: memory allocation flags (for bio_alloc)
- * @error_sector: error sector
- * @flags: BLKDEV_IFL_* flags to control behaviour
- *
- * Description:
- * Issue a flush for the block device in question. Caller can supply
- * room for storing the error offset in case of a flush error, if they
- * wish to. If WAIT flag is not passed then caller may check only what
- * request was pushed in some internal queue for later handling.
- */
-int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
- sector_t *error_sector, unsigned long flags)
-{
- DECLARE_COMPLETION_ONSTACK(wait);
- struct request_queue *q;
- struct bio *bio;
- int ret = 0;
-
- if (bdev->bd_disk == NULL)
- return -ENXIO;
-
- q = bdev_get_queue(bdev);
- if (!q)
- return -ENXIO;
-
- /*
- * some block devices may not have their queue correctly set up here
- * (e.g. loop device without a backing file) and so issuing a flush
- * here will panic. Ensure there is a request function before issuing
- * the barrier.
- */
- if (!q->make_request_fn)
- return -ENXIO;
-
- bio = bio_alloc(gfp_mask, 0);
- bio->bi_end_io = bio_end_empty_barrier;
- bio->bi_bdev = bdev;
- if (test_bit(BLKDEV_WAIT, &flags))
- bio->bi_private = &wait;
-
- bio_get(bio);
- submit_bio(WRITE_BARRIER, bio);
- if (test_bit(BLKDEV_WAIT, &flags)) {
- wait_for_completion(&wait);
- /*
- * The driver must store the error location in ->bi_sector, if
- * it supports it. For non-stacked drivers, this should be
- * copied from blk_rq_pos(rq).
- */
- if (error_sector)
- *error_sector = bio->bi_sector;
- }
-
- if (bio_flagged(bio, BIO_EOPNOTSUPP))
- ret = -EOPNOTSUPP;
- else if (!bio_flagged(bio, BIO_UPTODATE))
- ret = -EIO;
-
- bio_put(bio);
- return ret;
-}
-EXPORT_SYMBOL(blkdev_issue_flush);
diff --git a/block/blk-flush.c b/block/blk-flush.c
new file mode 100644
index 0000000..e8b2e5c
--- /dev/null
+++ b/block/blk-flush.c
@@ -0,0 +1,248 @@
+/*
+ * Functions related to barrier IO handling
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/gfp.h>
+
+#include "blk.h"
+
+static struct request *queue_next_ordseq(struct request_queue *q);
+
+/*
+ * Cache flushing for ordered writes handling
+ */
+unsigned blk_ordered_cur_seq(struct request_queue *q)
+{
+ if (!q->ordseq)
+ return 0;
+ return 1 << ffz(q->ordseq);
+}
+
+static struct request *blk_ordered_complete_seq(struct request_queue *q,
+ unsigned seq, int error)
+{
+ struct request *next_rq = NULL;
+
+ if (error && !q->orderr)
+ q->orderr = error;
+
+ BUG_ON(q->ordseq & seq);
+ q->ordseq |= seq;
+
+ if (blk_ordered_cur_seq(q) != QUEUE_ORDSEQ_DONE) {
+ /* not complete yet, queue the next ordered sequence */
+ next_rq = queue_next_ordseq(q);
+ } else {
+ /* complete this barrier request */
+ __blk_end_request_all(q->orig_bar_rq, q->orderr);
+ q->orig_bar_rq = NULL;
+ q->ordseq = 0;
+
+ /* dispatch the next barrier if there's one */
+ if (!list_empty(&q->pending_barriers)) {
+ next_rq = list_entry_rq(q->pending_barriers.next);
+ list_move(&next_rq->queuelist, &q->queue_head);
+ }
+ }
+ return next_rq;
+}
+
+static void pre_flush_end_io(struct request *rq, int error)
+{
+ elv_completed_request(rq->q, rq);
+ blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_PREFLUSH, error);
+}
+
+static void bar_end_io(struct request *rq, int error)
+{
+ elv_completed_request(rq->q, rq);
+ blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_BAR, error);
+}
+
+static void post_flush_end_io(struct request *rq, int error)
+{
+ elv_completed_request(rq->q, rq);
+ blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_POSTFLUSH, error);
+}
+
+static void queue_flush(struct request_queue *q, struct request *rq,
+ rq_end_io_fn *end_io)
+{
+ blk_rq_init(q, rq);
+ rq->cmd_type = REQ_TYPE_FS;
+ rq->cmd_flags = REQ_FLUSH;
+ rq->rq_disk = q->orig_bar_rq->rq_disk;
+ rq->end_io = end_io;
+
+ elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
+}
+
+static struct request *queue_next_ordseq(struct request_queue *q)
+{
+ struct request *rq = &q->bar_rq;
+
+ switch (blk_ordered_cur_seq(q)) {
+ case QUEUE_ORDSEQ_PREFLUSH:
+ queue_flush(q, rq, pre_flush_end_io);
+ break;
+
+ case QUEUE_ORDSEQ_BAR:
+ /* initialize proxy request and queue it */
+ blk_rq_init(q, rq);
+ init_request_from_bio(rq, q->orig_bar_rq->bio);
+ rq->cmd_flags &= ~REQ_HARDBARRIER;
+ if (q->ordered & QUEUE_ORDERED_DO_FUA)
+ rq->cmd_flags |= REQ_FUA;
+ rq->end_io = bar_end_io;
+
+ elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
+ break;
+
+ case QUEUE_ORDSEQ_POSTFLUSH:
+ queue_flush(q, rq, post_flush_end_io);
+ break;
+
+ default:
+ BUG();
+ }
+ return rq;
+}
+
+struct request *blk_do_ordered(struct request_queue *q, struct request *rq)
+{
+ unsigned skip = 0;
+
+ if (!(rq->cmd_flags & REQ_HARDBARRIER))
+ return rq;
+
+ if (q->ordseq) {
+ /*
+ * Barrier is already in progress and they can't be
+ * processed in parallel. Queue for later processing.
+ */
+ list_move_tail(&rq->queuelist, &q->pending_barriers);
+ return NULL;
+ }
+
+ if (unlikely(q->next_ordered == QUEUE_ORDERED_NONE)) {
+ /*
+ * Queue ordering not supported. Terminate
+ * with prejudice.
+ */
+ blk_dequeue_request(rq);
+ __blk_end_request_all(rq, -EOPNOTSUPP);
+ return NULL;
+ }
+
+ /*
+ * Start a new ordered sequence
+ */
+ q->orderr = 0;
+ q->ordered = q->next_ordered;
+ q->ordseq |= QUEUE_ORDSEQ_STARTED;
+
+ /*
+ * For an empty barrier, there's no actual BAR request, which
+ * in turn makes POSTFLUSH unnecessary. Mask them off.
+ */
+ if (!blk_rq_sectors(rq))
+ q->ordered &= ~(QUEUE_ORDERED_DO_BAR |
+ QUEUE_ORDERED_DO_POSTFLUSH);
+
+ /* stash away the original request */
+ blk_dequeue_request(rq);
+ q->orig_bar_rq = rq;
+
+ if (!(q->ordered & QUEUE_ORDERED_DO_PREFLUSH))
+ skip |= QUEUE_ORDSEQ_PREFLUSH;
+
+ if (!(q->ordered & QUEUE_ORDERED_DO_BAR))
+ skip |= QUEUE_ORDSEQ_BAR;
+
+ if (!(q->ordered & QUEUE_ORDERED_DO_POSTFLUSH))
+ skip |= QUEUE_ORDSEQ_POSTFLUSH;
+
+ /* complete skipped sequences and return the first sequence */
+ return blk_ordered_complete_seq(q, skip, 0);
+}
+
+static void bio_end_empty_barrier(struct bio *bio, int err)
+{
+ if (err) {
+ if (err == -EOPNOTSUPP)
+ set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
+ clear_bit(BIO_UPTODATE, &bio->bi_flags);
+ }
+ if (bio->bi_private)
+ complete(bio->bi_private);
+ bio_put(bio);
+}
+
+/**
+ * blkdev_issue_flush - queue a flush
+ * @bdev: blockdev to issue flush for
+ * @gfp_mask: memory allocation flags (for bio_alloc)
+ * @error_sector: error sector
+ * @flags: BLKDEV_IFL_* flags to control behaviour
+ *
+ * Description:
+ * Issue a flush for the block device in question. Caller can supply
+ * room for storing the error offset in case of a flush error, if they
+ * wish to. If WAIT flag is not passed then caller may check only what
+ * request was pushed in some internal queue for later handling.
+ */
+int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
+ sector_t *error_sector, unsigned long flags)
+{
+ DECLARE_COMPLETION_ONSTACK(wait);
+ struct request_queue *q;
+ struct bio *bio;
+ int ret = 0;
+
+ if (bdev->bd_disk == NULL)
+ return -ENXIO;
+
+ q = bdev_get_queue(bdev);
+ if (!q)
+ return -ENXIO;
+
+ /*
+ * some block devices may not have their queue correctly set up here
+ * (e.g. loop device without a backing file) and so issuing a flush
+ * here will panic. Ensure there is a request function before issuing
+ * the barrier.
+ */
+ if (!q->make_request_fn)
+ return -ENXIO;
+
+ bio = bio_alloc(gfp_mask, 0);
+ bio->bi_end_io = bio_end_empty_barrier;
+ bio->bi_bdev = bdev;
+ if (test_bit(BLKDEV_WAIT, &flags))
+ bio->bi_private = &wait;
+
+ bio_get(bio);
+ submit_bio(WRITE_BARRIER, bio);
+ if (test_bit(BLKDEV_WAIT, &flags)) {
+ wait_for_completion(&wait);
+ /*
+ * The driver must store the error location in ->bi_sector, if
+ * it supports it. For non-stacked drivers, this should be
+ * copied from blk_rq_pos(rq).
+ */
+ if (error_sector)
+ *error_sector = bio->bi_sector;
+ }
+
+ if (bio_flagged(bio, BIO_EOPNOTSUPP))
+ ret = -EOPNOTSUPP;
+ else if (!bio_flagged(bio, BIO_UPTODATE))
+ ret = -EIO;
+
+ bio_put(bio);
+ return ret;
+}
+EXPORT_SYMBOL(blkdev_issue_flush);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 08/41] block: rename blk-barrier.c to blk-flush.c
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo, Christoph Hellwig
Without ordering requirements, barrier and ordering are minomers.
Rename block/blk-barrier.c to block/blk-flush.c. Rename of symbols
will follow.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
---
block/Makefile | 2 +-
block/blk-barrier.c | 248 ---------------------------------------------------
block/blk-flush.c | 248 +++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 249 insertions(+), 249 deletions(-)
delete mode 100644 block/blk-barrier.c
create mode 100644 block/blk-flush.c
diff --git a/block/Makefile b/block/Makefile
index 0bb499a..f627e4b 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -3,7 +3,7 @@
#
obj-$(CONFIG_BLOCK) := elevator.o blk-core.o blk-tag.o blk-sysfs.o \
- blk-barrier.o blk-settings.o blk-ioc.o blk-map.o \
+ blk-flush.o blk-settings.o blk-ioc.o blk-map.o \
blk-exec.o blk-merge.o blk-softirq.o blk-timeout.o \
blk-iopoll.o blk-lib.o ioctl.o genhd.o scsi_ioctl.o
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
deleted file mode 100644
index e8b2e5c..0000000
--- a/block/blk-barrier.c
+++ /dev/null
@@ -1,248 +0,0 @@
-/*
- * Functions related to barrier IO handling
- */
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/bio.h>
-#include <linux/blkdev.h>
-#include <linux/gfp.h>
-
-#include "blk.h"
-
-static struct request *queue_next_ordseq(struct request_queue *q);
-
-/*
- * Cache flushing for ordered writes handling
- */
-unsigned blk_ordered_cur_seq(struct request_queue *q)
-{
- if (!q->ordseq)
- return 0;
- return 1 << ffz(q->ordseq);
-}
-
-static struct request *blk_ordered_complete_seq(struct request_queue *q,
- unsigned seq, int error)
-{
- struct request *next_rq = NULL;
-
- if (error && !q->orderr)
- q->orderr = error;
-
- BUG_ON(q->ordseq & seq);
- q->ordseq |= seq;
-
- if (blk_ordered_cur_seq(q) != QUEUE_ORDSEQ_DONE) {
- /* not complete yet, queue the next ordered sequence */
- next_rq = queue_next_ordseq(q);
- } else {
- /* complete this barrier request */
- __blk_end_request_all(q->orig_bar_rq, q->orderr);
- q->orig_bar_rq = NULL;
- q->ordseq = 0;
-
- /* dispatch the next barrier if there's one */
- if (!list_empty(&q->pending_barriers)) {
- next_rq = list_entry_rq(q->pending_barriers.next);
- list_move(&next_rq->queuelist, &q->queue_head);
- }
- }
- return next_rq;
-}
-
-static void pre_flush_end_io(struct request *rq, int error)
-{
- elv_completed_request(rq->q, rq);
- blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_PREFLUSH, error);
-}
-
-static void bar_end_io(struct request *rq, int error)
-{
- elv_completed_request(rq->q, rq);
- blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_BAR, error);
-}
-
-static void post_flush_end_io(struct request *rq, int error)
-{
- elv_completed_request(rq->q, rq);
- blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_POSTFLUSH, error);
-}
-
-static void queue_flush(struct request_queue *q, struct request *rq,
- rq_end_io_fn *end_io)
-{
- blk_rq_init(q, rq);
- rq->cmd_type = REQ_TYPE_FS;
- rq->cmd_flags = REQ_FLUSH;
- rq->rq_disk = q->orig_bar_rq->rq_disk;
- rq->end_io = end_io;
-
- elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
-}
-
-static struct request *queue_next_ordseq(struct request_queue *q)
-{
- struct request *rq = &q->bar_rq;
-
- switch (blk_ordered_cur_seq(q)) {
- case QUEUE_ORDSEQ_PREFLUSH:
- queue_flush(q, rq, pre_flush_end_io);
- break;
-
- case QUEUE_ORDSEQ_BAR:
- /* initialize proxy request and queue it */
- blk_rq_init(q, rq);
- init_request_from_bio(rq, q->orig_bar_rq->bio);
- rq->cmd_flags &= ~REQ_HARDBARRIER;
- if (q->ordered & QUEUE_ORDERED_DO_FUA)
- rq->cmd_flags |= REQ_FUA;
- rq->end_io = bar_end_io;
-
- elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
- break;
-
- case QUEUE_ORDSEQ_POSTFLUSH:
- queue_flush(q, rq, post_flush_end_io);
- break;
-
- default:
- BUG();
- }
- return rq;
-}
-
-struct request *blk_do_ordered(struct request_queue *q, struct request *rq)
-{
- unsigned skip = 0;
-
- if (!(rq->cmd_flags & REQ_HARDBARRIER))
- return rq;
-
- if (q->ordseq) {
- /*
- * Barrier is already in progress and they can't be
- * processed in parallel. Queue for later processing.
- */
- list_move_tail(&rq->queuelist, &q->pending_barriers);
- return NULL;
- }
-
- if (unlikely(q->next_ordered == QUEUE_ORDERED_NONE)) {
- /*
- * Queue ordering not supported. Terminate
- * with prejudice.
- */
- blk_dequeue_request(rq);
- __blk_end_request_all(rq, -EOPNOTSUPP);
- return NULL;
- }
-
- /*
- * Start a new ordered sequence
- */
- q->orderr = 0;
- q->ordered = q->next_ordered;
- q->ordseq |= QUEUE_ORDSEQ_STARTED;
-
- /*
- * For an empty barrier, there's no actual BAR request, which
- * in turn makes POSTFLUSH unnecessary. Mask them off.
- */
- if (!blk_rq_sectors(rq))
- q->ordered &= ~(QUEUE_ORDERED_DO_BAR |
- QUEUE_ORDERED_DO_POSTFLUSH);
-
- /* stash away the original request */
- blk_dequeue_request(rq);
- q->orig_bar_rq = rq;
-
- if (!(q->ordered & QUEUE_ORDERED_DO_PREFLUSH))
- skip |= QUEUE_ORDSEQ_PREFLUSH;
-
- if (!(q->ordered & QUEUE_ORDERED_DO_BAR))
- skip |= QUEUE_ORDSEQ_BAR;
-
- if (!(q->ordered & QUEUE_ORDERED_DO_POSTFLUSH))
- skip |= QUEUE_ORDSEQ_POSTFLUSH;
-
- /* complete skipped sequences and return the first sequence */
- return blk_ordered_complete_seq(q, skip, 0);
-}
-
-static void bio_end_empty_barrier(struct bio *bio, int err)
-{
- if (err) {
- if (err == -EOPNOTSUPP)
- set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
- clear_bit(BIO_UPTODATE, &bio->bi_flags);
- }
- if (bio->bi_private)
- complete(bio->bi_private);
- bio_put(bio);
-}
-
-/**
- * blkdev_issue_flush - queue a flush
- * @bdev: blockdev to issue flush for
- * @gfp_mask: memory allocation flags (for bio_alloc)
- * @error_sector: error sector
- * @flags: BLKDEV_IFL_* flags to control behaviour
- *
- * Description:
- * Issue a flush for the block device in question. Caller can supply
- * room for storing the error offset in case of a flush error, if they
- * wish to. If WAIT flag is not passed then caller may check only what
- * request was pushed in some internal queue for later handling.
- */
-int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
- sector_t *error_sector, unsigned long flags)
-{
- DECLARE_COMPLETION_ONSTACK(wait);
- struct request_queue *q;
- struct bio *bio;
- int ret = 0;
-
- if (bdev->bd_disk == NULL)
- return -ENXIO;
-
- q = bdev_get_queue(bdev);
- if (!q)
- return -ENXIO;
-
- /*
- * some block devices may not have their queue correctly set up here
- * (e.g. loop device without a backing file) and so issuing a flush
- * here will panic. Ensure there is a request function before issuing
- * the barrier.
- */
- if (!q->make_request_fn)
- return -ENXIO;
-
- bio = bio_alloc(gfp_mask, 0);
- bio->bi_end_io = bio_end_empty_barrier;
- bio->bi_bdev = bdev;
- if (test_bit(BLKDEV_WAIT, &flags))
- bio->bi_private = &wait;
-
- bio_get(bio);
- submit_bio(WRITE_BARRIER, bio);
- if (test_bit(BLKDEV_WAIT, &flags)) {
- wait_for_completion(&wait);
- /*
- * The driver must store the error location in ->bi_sector, if
- * it supports it. For non-stacked drivers, this should be
- * copied from blk_rq_pos(rq).
- */
- if (error_sector)
- *error_sector = bio->bi_sector;
- }
-
- if (bio_flagged(bio, BIO_EOPNOTSUPP))
- ret = -EOPNOTSUPP;
- else if (!bio_flagged(bio, BIO_UPTODATE))
- ret = -EIO;
-
- bio_put(bio);
- return ret;
-}
-EXPORT_SYMBOL(blkdev_issue_flush);
diff --git a/block/blk-flush.c b/block/blk-flush.c
new file mode 100644
index 0000000..e8b2e5c
--- /dev/null
+++ b/block/blk-flush.c
@@ -0,0 +1,248 @@
+/*
+ * Functions related to barrier IO handling
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/gfp.h>
+
+#include "blk.h"
+
+static struct request *queue_next_ordseq(struct request_queue *q);
+
+/*
+ * Cache flushing for ordered writes handling
+ */
+unsigned blk_ordered_cur_seq(struct request_queue *q)
+{
+ if (!q->ordseq)
+ return 0;
+ return 1 << ffz(q->ordseq);
+}
+
+static struct request *blk_ordered_complete_seq(struct request_queue *q,
+ unsigned seq, int error)
+{
+ struct request *next_rq = NULL;
+
+ if (error && !q->orderr)
+ q->orderr = error;
+
+ BUG_ON(q->ordseq & seq);
+ q->ordseq |= seq;
+
+ if (blk_ordered_cur_seq(q) != QUEUE_ORDSEQ_DONE) {
+ /* not complete yet, queue the next ordered sequence */
+ next_rq = queue_next_ordseq(q);
+ } else {
+ /* complete this barrier request */
+ __blk_end_request_all(q->orig_bar_rq, q->orderr);
+ q->orig_bar_rq = NULL;
+ q->ordseq = 0;
+
+ /* dispatch the next barrier if there's one */
+ if (!list_empty(&q->pending_barriers)) {
+ next_rq = list_entry_rq(q->pending_barriers.next);
+ list_move(&next_rq->queuelist, &q->queue_head);
+ }
+ }
+ return next_rq;
+}
+
+static void pre_flush_end_io(struct request *rq, int error)
+{
+ elv_completed_request(rq->q, rq);
+ blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_PREFLUSH, error);
+}
+
+static void bar_end_io(struct request *rq, int error)
+{
+ elv_completed_request(rq->q, rq);
+ blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_BAR, error);
+}
+
+static void post_flush_end_io(struct request *rq, int error)
+{
+ elv_completed_request(rq->q, rq);
+ blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_POSTFLUSH, error);
+}
+
+static void queue_flush(struct request_queue *q, struct request *rq,
+ rq_end_io_fn *end_io)
+{
+ blk_rq_init(q, rq);
+ rq->cmd_type = REQ_TYPE_FS;
+ rq->cmd_flags = REQ_FLUSH;
+ rq->rq_disk = q->orig_bar_rq->rq_disk;
+ rq->end_io = end_io;
+
+ elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
+}
+
+static struct request *queue_next_ordseq(struct request_queue *q)
+{
+ struct request *rq = &q->bar_rq;
+
+ switch (blk_ordered_cur_seq(q)) {
+ case QUEUE_ORDSEQ_PREFLUSH:
+ queue_flush(q, rq, pre_flush_end_io);
+ break;
+
+ case QUEUE_ORDSEQ_BAR:
+ /* initialize proxy request and queue it */
+ blk_rq_init(q, rq);
+ init_request_from_bio(rq, q->orig_bar_rq->bio);
+ rq->cmd_flags &= ~REQ_HARDBARRIER;
+ if (q->ordered & QUEUE_ORDERED_DO_FUA)
+ rq->cmd_flags |= REQ_FUA;
+ rq->end_io = bar_end_io;
+
+ elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
+ break;
+
+ case QUEUE_ORDSEQ_POSTFLUSH:
+ queue_flush(q, rq, post_flush_end_io);
+ break;
+
+ default:
+ BUG();
+ }
+ return rq;
+}
+
+struct request *blk_do_ordered(struct request_queue *q, struct request *rq)
+{
+ unsigned skip = 0;
+
+ if (!(rq->cmd_flags & REQ_HARDBARRIER))
+ return rq;
+
+ if (q->ordseq) {
+ /*
+ * Barrier is already in progress and they can't be
+ * processed in parallel. Queue for later processing.
+ */
+ list_move_tail(&rq->queuelist, &q->pending_barriers);
+ return NULL;
+ }
+
+ if (unlikely(q->next_ordered == QUEUE_ORDERED_NONE)) {
+ /*
+ * Queue ordering not supported. Terminate
+ * with prejudice.
+ */
+ blk_dequeue_request(rq);
+ __blk_end_request_all(rq, -EOPNOTSUPP);
+ return NULL;
+ }
+
+ /*
+ * Start a new ordered sequence
+ */
+ q->orderr = 0;
+ q->ordered = q->next_ordered;
+ q->ordseq |= QUEUE_ORDSEQ_STARTED;
+
+ /*
+ * For an empty barrier, there's no actual BAR request, which
+ * in turn makes POSTFLUSH unnecessary. Mask them off.
+ */
+ if (!blk_rq_sectors(rq))
+ q->ordered &= ~(QUEUE_ORDERED_DO_BAR |
+ QUEUE_ORDERED_DO_POSTFLUSH);
+
+ /* stash away the original request */
+ blk_dequeue_request(rq);
+ q->orig_bar_rq = rq;
+
+ if (!(q->ordered & QUEUE_ORDERED_DO_PREFLUSH))
+ skip |= QUEUE_ORDSEQ_PREFLUSH;
+
+ if (!(q->ordered & QUEUE_ORDERED_DO_BAR))
+ skip |= QUEUE_ORDSEQ_BAR;
+
+ if (!(q->ordered & QUEUE_ORDERED_DO_POSTFLUSH))
+ skip |= QUEUE_ORDSEQ_POSTFLUSH;
+
+ /* complete skipped sequences and return the first sequence */
+ return blk_ordered_complete_seq(q, skip, 0);
+}
+
+static void bio_end_empty_barrier(struct bio *bio, int err)
+{
+ if (err) {
+ if (err == -EOPNOTSUPP)
+ set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
+ clear_bit(BIO_UPTODATE, &bio->bi_flags);
+ }
+ if (bio->bi_private)
+ complete(bio->bi_private);
+ bio_put(bio);
+}
+
+/**
+ * blkdev_issue_flush - queue a flush
+ * @bdev: blockdev to issue flush for
+ * @gfp_mask: memory allocation flags (for bio_alloc)
+ * @error_sector: error sector
+ * @flags: BLKDEV_IFL_* flags to control behaviour
+ *
+ * Description:
+ * Issue a flush for the block device in question. Caller can supply
+ * room for storing the error offset in case of a flush error, if they
+ * wish to. If WAIT flag is not passed then caller may check only what
+ * request was pushed in some internal queue for later handling.
+ */
+int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
+ sector_t *error_sector, unsigned long flags)
+{
+ DECLARE_COMPLETION_ONSTACK(wait);
+ struct request_queue *q;
+ struct bio *bio;
+ int ret = 0;
+
+ if (bdev->bd_disk == NULL)
+ return -ENXIO;
+
+ q = bdev_get_queue(bdev);
+ if (!q)
+ return -ENXIO;
+
+ /*
+ * some block devices may not have their queue correctly set up here
+ * (e.g. loop device without a backing file) and so issuing a flush
+ * here will panic. Ensure there is a request function before issuing
+ * the barrier.
+ */
+ if (!q->make_request_fn)
+ return -ENXIO;
+
+ bio = bio_alloc(gfp_mask, 0);
+ bio->bi_end_io = bio_end_empty_barrier;
+ bio->bi_bdev = bdev;
+ if (test_bit(BLKDEV_WAIT, &flags))
+ bio->bi_private = &wait;
+
+ bio_get(bio);
+ submit_bio(WRITE_BARRIER, bio);
+ if (test_bit(BLKDEV_WAIT, &flags)) {
+ wait_for_completion(&wait);
+ /*
+ * The driver must store the error location in ->bi_sector, if
+ * it supports it. For non-stacked drivers, this should be
+ * copied from blk_rq_pos(rq).
+ */
+ if (error_sector)
+ *error_sector = bio->bi_sector;
+ }
+
+ if (bio_flagged(bio, BIO_EOPNOTSUPP))
+ ret = -EOPNOTSUPP;
+ else if (!bio_flagged(bio, BIO_UPTODATE))
+ ret = -EIO;
+
+ bio_put(bio);
+ return ret;
+}
+EXPORT_SYMBOL(blkdev_issue_flush);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 08/41] block: rename blk-barrier.c to blk-flush.c
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo, Christoph Hellwig
Without ordering requirements, barrier and ordering are minomers.
Rename block/blk-barrier.c to block/blk-flush.c. Rename of symbols
will follow.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
---
block/Makefile | 2 +-
block/blk-barrier.c | 248 ---------------------------------------------------
block/blk-flush.c | 248 +++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 249 insertions(+), 249 deletions(-)
delete mode 100644 block/blk-barrier.c
create mode 100644 block/blk-flush.c
diff --git a/block/Makefile b/block/Makefile
index 0bb499a..f627e4b 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -3,7 +3,7 @@
#
obj-$(CONFIG_BLOCK) := elevator.o blk-core.o blk-tag.o blk-sysfs.o \
- blk-barrier.o blk-settings.o blk-ioc.o blk-map.o \
+ blk-flush.o blk-settings.o blk-ioc.o blk-map.o \
blk-exec.o blk-merge.o blk-softirq.o blk-timeout.o \
blk-iopoll.o blk-lib.o ioctl.o genhd.o scsi_ioctl.o
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
deleted file mode 100644
index e8b2e5c..0000000
--- a/block/blk-barrier.c
+++ /dev/null
@@ -1,248 +0,0 @@
-/*
- * Functions related to barrier IO handling
- */
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/bio.h>
-#include <linux/blkdev.h>
-#include <linux/gfp.h>
-
-#include "blk.h"
-
-static struct request *queue_next_ordseq(struct request_queue *q);
-
-/*
- * Cache flushing for ordered writes handling
- */
-unsigned blk_ordered_cur_seq(struct request_queue *q)
-{
- if (!q->ordseq)
- return 0;
- return 1 << ffz(q->ordseq);
-}
-
-static struct request *blk_ordered_complete_seq(struct request_queue *q,
- unsigned seq, int error)
-{
- struct request *next_rq = NULL;
-
- if (error && !q->orderr)
- q->orderr = error;
-
- BUG_ON(q->ordseq & seq);
- q->ordseq |= seq;
-
- if (blk_ordered_cur_seq(q) != QUEUE_ORDSEQ_DONE) {
- /* not complete yet, queue the next ordered sequence */
- next_rq = queue_next_ordseq(q);
- } else {
- /* complete this barrier request */
- __blk_end_request_all(q->orig_bar_rq, q->orderr);
- q->orig_bar_rq = NULL;
- q->ordseq = 0;
-
- /* dispatch the next barrier if there's one */
- if (!list_empty(&q->pending_barriers)) {
- next_rq = list_entry_rq(q->pending_barriers.next);
- list_move(&next_rq->queuelist, &q->queue_head);
- }
- }
- return next_rq;
-}
-
-static void pre_flush_end_io(struct request *rq, int error)
-{
- elv_completed_request(rq->q, rq);
- blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_PREFLUSH, error);
-}
-
-static void bar_end_io(struct request *rq, int error)
-{
- elv_completed_request(rq->q, rq);
- blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_BAR, error);
-}
-
-static void post_flush_end_io(struct request *rq, int error)
-{
- elv_completed_request(rq->q, rq);
- blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_POSTFLUSH, error);
-}
-
-static void queue_flush(struct request_queue *q, struct request *rq,
- rq_end_io_fn *end_io)
-{
- blk_rq_init(q, rq);
- rq->cmd_type = REQ_TYPE_FS;
- rq->cmd_flags = REQ_FLUSH;
- rq->rq_disk = q->orig_bar_rq->rq_disk;
- rq->end_io = end_io;
-
- elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
-}
-
-static struct request *queue_next_ordseq(struct request_queue *q)
-{
- struct request *rq = &q->bar_rq;
-
- switch (blk_ordered_cur_seq(q)) {
- case QUEUE_ORDSEQ_PREFLUSH:
- queue_flush(q, rq, pre_flush_end_io);
- break;
-
- case QUEUE_ORDSEQ_BAR:
- /* initialize proxy request and queue it */
- blk_rq_init(q, rq);
- init_request_from_bio(rq, q->orig_bar_rq->bio);
- rq->cmd_flags &= ~REQ_HARDBARRIER;
- if (q->ordered & QUEUE_ORDERED_DO_FUA)
- rq->cmd_flags |= REQ_FUA;
- rq->end_io = bar_end_io;
-
- elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
- break;
-
- case QUEUE_ORDSEQ_POSTFLUSH:
- queue_flush(q, rq, post_flush_end_io);
- break;
-
- default:
- BUG();
- }
- return rq;
-}
-
-struct request *blk_do_ordered(struct request_queue *q, struct request *rq)
-{
- unsigned skip = 0;
-
- if (!(rq->cmd_flags & REQ_HARDBARRIER))
- return rq;
-
- if (q->ordseq) {
- /*
- * Barrier is already in progress and they can't be
- * processed in parallel. Queue for later processing.
- */
- list_move_tail(&rq->queuelist, &q->pending_barriers);
- return NULL;
- }
-
- if (unlikely(q->next_ordered == QUEUE_ORDERED_NONE)) {
- /*
- * Queue ordering not supported. Terminate
- * with prejudice.
- */
- blk_dequeue_request(rq);
- __blk_end_request_all(rq, -EOPNOTSUPP);
- return NULL;
- }
-
- /*
- * Start a new ordered sequence
- */
- q->orderr = 0;
- q->ordered = q->next_ordered;
- q->ordseq |= QUEUE_ORDSEQ_STARTED;
-
- /*
- * For an empty barrier, there's no actual BAR request, which
- * in turn makes POSTFLUSH unnecessary. Mask them off.
- */
- if (!blk_rq_sectors(rq))
- q->ordered &= ~(QUEUE_ORDERED_DO_BAR |
- QUEUE_ORDERED_DO_POSTFLUSH);
-
- /* stash away the original request */
- blk_dequeue_request(rq);
- q->orig_bar_rq = rq;
-
- if (!(q->ordered & QUEUE_ORDERED_DO_PREFLUSH))
- skip |= QUEUE_ORDSEQ_PREFLUSH;
-
- if (!(q->ordered & QUEUE_ORDERED_DO_BAR))
- skip |= QUEUE_ORDSEQ_BAR;
-
- if (!(q->ordered & QUEUE_ORDERED_DO_POSTFLUSH))
- skip |= QUEUE_ORDSEQ_POSTFLUSH;
-
- /* complete skipped sequences and return the first sequence */
- return blk_ordered_complete_seq(q, skip, 0);
-}
-
-static void bio_end_empty_barrier(struct bio *bio, int err)
-{
- if (err) {
- if (err == -EOPNOTSUPP)
- set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
- clear_bit(BIO_UPTODATE, &bio->bi_flags);
- }
- if (bio->bi_private)
- complete(bio->bi_private);
- bio_put(bio);
-}
-
-/**
- * blkdev_issue_flush - queue a flush
- * @bdev: blockdev to issue flush for
- * @gfp_mask: memory allocation flags (for bio_alloc)
- * @error_sector: error sector
- * @flags: BLKDEV_IFL_* flags to control behaviour
- *
- * Description:
- * Issue a flush for the block device in question. Caller can supply
- * room for storing the error offset in case of a flush error, if they
- * wish to. If WAIT flag is not passed then caller may check only what
- * request was pushed in some internal queue for later handling.
- */
-int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
- sector_t *error_sector, unsigned long flags)
-{
- DECLARE_COMPLETION_ONSTACK(wait);
- struct request_queue *q;
- struct bio *bio;
- int ret = 0;
-
- if (bdev->bd_disk == NULL)
- return -ENXIO;
-
- q = bdev_get_queue(bdev);
- if (!q)
- return -ENXIO;
-
- /*
- * some block devices may not have their queue correctly set up here
- * (e.g. loop device without a backing file) and so issuing a flush
- * here will panic. Ensure there is a request function before issuing
- * the barrier.
- */
- if (!q->make_request_fn)
- return -ENXIO;
-
- bio = bio_alloc(gfp_mask, 0);
- bio->bi_end_io = bio_end_empty_barrier;
- bio->bi_bdev = bdev;
- if (test_bit(BLKDEV_WAIT, &flags))
- bio->bi_private = &wait;
-
- bio_get(bio);
- submit_bio(WRITE_BARRIER, bio);
- if (test_bit(BLKDEV_WAIT, &flags)) {
- wait_for_completion(&wait);
- /*
- * The driver must store the error location in ->bi_sector, if
- * it supports it. For non-stacked drivers, this should be
- * copied from blk_rq_pos(rq).
- */
- if (error_sector)
- *error_sector = bio->bi_sector;
- }
-
- if (bio_flagged(bio, BIO_EOPNOTSUPP))
- ret = -EOPNOTSUPP;
- else if (!bio_flagged(bio, BIO_UPTODATE))
- ret = -EIO;
-
- bio_put(bio);
- return ret;
-}
-EXPORT_SYMBOL(blkdev_issue_flush);
diff --git a/block/blk-flush.c b/block/blk-flush.c
new file mode 100644
index 0000000..e8b2e5c
--- /dev/null
+++ b/block/blk-flush.c
@@ -0,0 +1,248 @@
+/*
+ * Functions related to barrier IO handling
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/gfp.h>
+
+#include "blk.h"
+
+static struct request *queue_next_ordseq(struct request_queue *q);
+
+/*
+ * Cache flushing for ordered writes handling
+ */
+unsigned blk_ordered_cur_seq(struct request_queue *q)
+{
+ if (!q->ordseq)
+ return 0;
+ return 1 << ffz(q->ordseq);
+}
+
+static struct request *blk_ordered_complete_seq(struct request_queue *q,
+ unsigned seq, int error)
+{
+ struct request *next_rq = NULL;
+
+ if (error && !q->orderr)
+ q->orderr = error;
+
+ BUG_ON(q->ordseq & seq);
+ q->ordseq |= seq;
+
+ if (blk_ordered_cur_seq(q) != QUEUE_ORDSEQ_DONE) {
+ /* not complete yet, queue the next ordered sequence */
+ next_rq = queue_next_ordseq(q);
+ } else {
+ /* complete this barrier request */
+ __blk_end_request_all(q->orig_bar_rq, q->orderr);
+ q->orig_bar_rq = NULL;
+ q->ordseq = 0;
+
+ /* dispatch the next barrier if there's one */
+ if (!list_empty(&q->pending_barriers)) {
+ next_rq = list_entry_rq(q->pending_barriers.next);
+ list_move(&next_rq->queuelist, &q->queue_head);
+ }
+ }
+ return next_rq;
+}
+
+static void pre_flush_end_io(struct request *rq, int error)
+{
+ elv_completed_request(rq->q, rq);
+ blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_PREFLUSH, error);
+}
+
+static void bar_end_io(struct request *rq, int error)
+{
+ elv_completed_request(rq->q, rq);
+ blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_BAR, error);
+}
+
+static void post_flush_end_io(struct request *rq, int error)
+{
+ elv_completed_request(rq->q, rq);
+ blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_POSTFLUSH, error);
+}
+
+static void queue_flush(struct request_queue *q, struct request *rq,
+ rq_end_io_fn *end_io)
+{
+ blk_rq_init(q, rq);
+ rq->cmd_type = REQ_TYPE_FS;
+ rq->cmd_flags = REQ_FLUSH;
+ rq->rq_disk = q->orig_bar_rq->rq_disk;
+ rq->end_io = end_io;
+
+ elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
+}
+
+static struct request *queue_next_ordseq(struct request_queue *q)
+{
+ struct request *rq = &q->bar_rq;
+
+ switch (blk_ordered_cur_seq(q)) {
+ case QUEUE_ORDSEQ_PREFLUSH:
+ queue_flush(q, rq, pre_flush_end_io);
+ break;
+
+ case QUEUE_ORDSEQ_BAR:
+ /* initialize proxy request and queue it */
+ blk_rq_init(q, rq);
+ init_request_from_bio(rq, q->orig_bar_rq->bio);
+ rq->cmd_flags &= ~REQ_HARDBARRIER;
+ if (q->ordered & QUEUE_ORDERED_DO_FUA)
+ rq->cmd_flags |= REQ_FUA;
+ rq->end_io = bar_end_io;
+
+ elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
+ break;
+
+ case QUEUE_ORDSEQ_POSTFLUSH:
+ queue_flush(q, rq, post_flush_end_io);
+ break;
+
+ default:
+ BUG();
+ }
+ return rq;
+}
+
+struct request *blk_do_ordered(struct request_queue *q, struct request *rq)
+{
+ unsigned skip = 0;
+
+ if (!(rq->cmd_flags & REQ_HARDBARRIER))
+ return rq;
+
+ if (q->ordseq) {
+ /*
+ * Barrier is already in progress and they can't be
+ * processed in parallel. Queue for later processing.
+ */
+ list_move_tail(&rq->queuelist, &q->pending_barriers);
+ return NULL;
+ }
+
+ if (unlikely(q->next_ordered == QUEUE_ORDERED_NONE)) {
+ /*
+ * Queue ordering not supported. Terminate
+ * with prejudice.
+ */
+ blk_dequeue_request(rq);
+ __blk_end_request_all(rq, -EOPNOTSUPP);
+ return NULL;
+ }
+
+ /*
+ * Start a new ordered sequence
+ */
+ q->orderr = 0;
+ q->ordered = q->next_ordered;
+ q->ordseq |= QUEUE_ORDSEQ_STARTED;
+
+ /*
+ * For an empty barrier, there's no actual BAR request, which
+ * in turn makes POSTFLUSH unnecessary. Mask them off.
+ */
+ if (!blk_rq_sectors(rq))
+ q->ordered &= ~(QUEUE_ORDERED_DO_BAR |
+ QUEUE_ORDERED_DO_POSTFLUSH);
+
+ /* stash away the original request */
+ blk_dequeue_request(rq);
+ q->orig_bar_rq = rq;
+
+ if (!(q->ordered & QUEUE_ORDERED_DO_PREFLUSH))
+ skip |= QUEUE_ORDSEQ_PREFLUSH;
+
+ if (!(q->ordered & QUEUE_ORDERED_DO_BAR))
+ skip |= QUEUE_ORDSEQ_BAR;
+
+ if (!(q->ordered & QUEUE_ORDERED_DO_POSTFLUSH))
+ skip |= QUEUE_ORDSEQ_POSTFLUSH;
+
+ /* complete skipped sequences and return the first sequence */
+ return blk_ordered_complete_seq(q, skip, 0);
+}
+
+static void bio_end_empty_barrier(struct bio *bio, int err)
+{
+ if (err) {
+ if (err == -EOPNOTSUPP)
+ set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
+ clear_bit(BIO_UPTODATE, &bio->bi_flags);
+ }
+ if (bio->bi_private)
+ complete(bio->bi_private);
+ bio_put(bio);
+}
+
+/**
+ * blkdev_issue_flush - queue a flush
+ * @bdev: blockdev to issue flush for
+ * @gfp_mask: memory allocation flags (for bio_alloc)
+ * @error_sector: error sector
+ * @flags: BLKDEV_IFL_* flags to control behaviour
+ *
+ * Description:
+ * Issue a flush for the block device in question. Caller can supply
+ * room for storing the error offset in case of a flush error, if they
+ * wish to. If WAIT flag is not passed then caller may check only what
+ * request was pushed in some internal queue for later handling.
+ */
+int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
+ sector_t *error_sector, unsigned long flags)
+{
+ DECLARE_COMPLETION_ONSTACK(wait);
+ struct request_queue *q;
+ struct bio *bio;
+ int ret = 0;
+
+ if (bdev->bd_disk == NULL)
+ return -ENXIO;
+
+ q = bdev_get_queue(bdev);
+ if (!q)
+ return -ENXIO;
+
+ /*
+ * some block devices may not have their queue correctly set up here
+ * (e.g. loop device without a backing file) and so issuing a flush
+ * here will panic. Ensure there is a request function before issuing
+ * the barrier.
+ */
+ if (!q->make_request_fn)
+ return -ENXIO;
+
+ bio = bio_alloc(gfp_mask, 0);
+ bio->bi_end_io = bio_end_empty_barrier;
+ bio->bi_bdev = bdev;
+ if (test_bit(BLKDEV_WAIT, &flags))
+ bio->bi_private = &wait;
+
+ bio_get(bio);
+ submit_bio(WRITE_BARRIER, bio);
+ if (test_bit(BLKDEV_WAIT, &flags)) {
+ wait_for_completion(&wait);
+ /*
+ * The driver must store the error location in ->bi_sector, if
+ * it supports it. For non-stacked drivers, this should be
+ * copied from blk_rq_pos(rq).
+ */
+ if (error_sector)
+ *error_sector = bio->bi_sector;
+ }
+
+ if (bio_flagged(bio, BIO_EOPNOTSUPP))
+ ret = -EOPNOTSUPP;
+ else if (!bio_flagged(bio, BIO_UPTODATE))
+ ret = -EIO;
+
+ bio_put(bio);
+ return ret;
+}
+EXPORT_SYMBOL(blkdev_issue_flush);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 09/41] block: rename barrier/ordered to flush
2010-09-03 10:29 ` Tejun Heo
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel
Cc: Tejun Heo, Christoph Hellwig
With ordering requirements dropped, barrier and ordered are misnomers.
Now all block layer does is sequencing FLUSH and FUA. Rename them to
flush.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
---
block/blk-core.c | 21 +++++-----
block/blk-flush.c | 98 +++++++++++++++++++++++------------------------
block/blk.h | 4 +-
include/linux/blkdev.h | 24 ++++++------
4 files changed, 72 insertions(+), 75 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index d316662..8870ae4 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -136,7 +136,7 @@ static void req_bio_endio(struct request *rq, struct bio *bio,
{
struct request_queue *q = rq->q;
- if (&q->bar_rq != rq) {
+ if (&q->flush_rq != rq) {
if (error)
clear_bit(BIO_UPTODATE, &bio->bi_flags);
else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
@@ -160,13 +160,12 @@ static void req_bio_endio(struct request *rq, struct bio *bio,
if (bio->bi_size == 0)
bio_endio(bio, error);
} else {
-
/*
- * Okay, this is the barrier request in progress, just
- * record the error;
+ * Okay, this is the sequenced flush request in
+ * progress, just record the error;
*/
- if (error && !q->orderr)
- q->orderr = error;
+ if (error && !q->flush_err)
+ q->flush_err = error;
}
}
@@ -520,7 +519,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
init_timer(&q->unplug_timer);
setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q);
INIT_LIST_HEAD(&q->timeout_list);
- INIT_LIST_HEAD(&q->pending_barriers);
+ INIT_LIST_HEAD(&q->pending_flushes);
INIT_WORK(&q->unplug_work, blk_unplug_work);
kobject_init(&q->kobj, &blk_queue_ktype);
@@ -1764,11 +1763,11 @@ static void blk_account_io_completion(struct request *req, unsigned int bytes)
static void blk_account_io_done(struct request *req)
{
/*
- * Account IO completion. bar_rq isn't accounted as a normal
- * IO on queueing nor completion. Accounting the containing
- * request is enough.
+ * Account IO completion. flush_rq isn't accounted as a
+ * normal IO on queueing nor completion. Accounting the
+ * containing request is enough.
*/
- if (blk_do_io_stat(req) && req != &req->q->bar_rq) {
+ if (blk_do_io_stat(req) && req != &req->q->flush_rq) {
unsigned long duration = jiffies - req->start_time;
const int rw = rq_data_dir(req);
struct hd_struct *part;
diff --git a/block/blk-flush.c b/block/blk-flush.c
index e8b2e5c..dd87322 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -9,41 +9,38 @@
#include "blk.h"
-static struct request *queue_next_ordseq(struct request_queue *q);
+static struct request *queue_next_fseq(struct request_queue *q);
-/*
- * Cache flushing for ordered writes handling
- */
-unsigned blk_ordered_cur_seq(struct request_queue *q)
+unsigned blk_flush_cur_seq(struct request_queue *q)
{
- if (!q->ordseq)
+ if (!q->flush_seq)
return 0;
- return 1 << ffz(q->ordseq);
+ return 1 << ffz(q->flush_seq);
}
-static struct request *blk_ordered_complete_seq(struct request_queue *q,
- unsigned seq, int error)
+static struct request *blk_flush_complete_seq(struct request_queue *q,
+ unsigned seq, int error)
{
struct request *next_rq = NULL;
- if (error && !q->orderr)
- q->orderr = error;
+ if (error && !q->flush_err)
+ q->flush_err = error;
- BUG_ON(q->ordseq & seq);
- q->ordseq |= seq;
+ BUG_ON(q->flush_seq & seq);
+ q->flush_seq |= seq;
- if (blk_ordered_cur_seq(q) != QUEUE_ORDSEQ_DONE) {
- /* not complete yet, queue the next ordered sequence */
- next_rq = queue_next_ordseq(q);
+ if (blk_flush_cur_seq(q) != QUEUE_FSEQ_DONE) {
+ /* not complete yet, queue the next flush sequence */
+ next_rq = queue_next_fseq(q);
} else {
- /* complete this barrier request */
- __blk_end_request_all(q->orig_bar_rq, q->orderr);
- q->orig_bar_rq = NULL;
- q->ordseq = 0;
-
- /* dispatch the next barrier if there's one */
- if (!list_empty(&q->pending_barriers)) {
- next_rq = list_entry_rq(q->pending_barriers.next);
+ /* complete this flush request */
+ __blk_end_request_all(q->orig_flush_rq, q->flush_err);
+ q->orig_flush_rq = NULL;
+ q->flush_seq = 0;
+
+ /* dispatch the next flush if there's one */
+ if (!list_empty(&q->pending_flushes)) {
+ next_rq = list_entry_rq(q->pending_flushes.next);
list_move(&next_rq->queuelist, &q->queue_head);
}
}
@@ -53,19 +50,19 @@ static struct request *blk_ordered_complete_seq(struct request_queue *q,
static void pre_flush_end_io(struct request *rq, int error)
{
elv_completed_request(rq->q, rq);
- blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_PREFLUSH, error);
+ blk_flush_complete_seq(rq->q, QUEUE_FSEQ_PREFLUSH, error);
}
-static void bar_end_io(struct request *rq, int error)
+static void flush_data_end_io(struct request *rq, int error)
{
elv_completed_request(rq->q, rq);
- blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_BAR, error);
+ blk_flush_complete_seq(rq->q, QUEUE_FSEQ_DATA, error);
}
static void post_flush_end_io(struct request *rq, int error)
{
elv_completed_request(rq->q, rq);
- blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_POSTFLUSH, error);
+ blk_flush_complete_seq(rq->q, QUEUE_FSEQ_POSTFLUSH, error);
}
static void queue_flush(struct request_queue *q, struct request *rq,
@@ -74,34 +71,34 @@ static void queue_flush(struct request_queue *q, struct request *rq,
blk_rq_init(q, rq);
rq->cmd_type = REQ_TYPE_FS;
rq->cmd_flags = REQ_FLUSH;
- rq->rq_disk = q->orig_bar_rq->rq_disk;
+ rq->rq_disk = q->orig_flush_rq->rq_disk;
rq->end_io = end_io;
elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
}
-static struct request *queue_next_ordseq(struct request_queue *q)
+static struct request *queue_next_fseq(struct request_queue *q)
{
- struct request *rq = &q->bar_rq;
+ struct request *rq = &q->flush_rq;
- switch (blk_ordered_cur_seq(q)) {
- case QUEUE_ORDSEQ_PREFLUSH:
+ switch (blk_flush_cur_seq(q)) {
+ case QUEUE_FSEQ_PREFLUSH:
queue_flush(q, rq, pre_flush_end_io);
break;
- case QUEUE_ORDSEQ_BAR:
+ case QUEUE_FSEQ_DATA:
/* initialize proxy request and queue it */
blk_rq_init(q, rq);
- init_request_from_bio(rq, q->orig_bar_rq->bio);
+ init_request_from_bio(rq, q->orig_flush_rq->bio);
rq->cmd_flags &= ~REQ_HARDBARRIER;
if (q->ordered & QUEUE_ORDERED_DO_FUA)
rq->cmd_flags |= REQ_FUA;
- rq->end_io = bar_end_io;
+ rq->end_io = flush_data_end_io;
elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
break;
- case QUEUE_ORDSEQ_POSTFLUSH:
+ case QUEUE_FSEQ_POSTFLUSH:
queue_flush(q, rq, post_flush_end_io);
break;
@@ -111,19 +108,20 @@ static struct request *queue_next_ordseq(struct request_queue *q)
return rq;
}
-struct request *blk_do_ordered(struct request_queue *q, struct request *rq)
+struct request *blk_do_flush(struct request_queue *q, struct request *rq)
{
unsigned skip = 0;
if (!(rq->cmd_flags & REQ_HARDBARRIER))
return rq;
- if (q->ordseq) {
+ if (q->flush_seq) {
/*
- * Barrier is already in progress and they can't be
- * processed in parallel. Queue for later processing.
+ * Sequenced flush is already in progress and they
+ * can't be processed in parallel. Queue for later
+ * processing.
*/
- list_move_tail(&rq->queuelist, &q->pending_barriers);
+ list_move_tail(&rq->queuelist, &q->pending_flushes);
return NULL;
}
@@ -138,11 +136,11 @@ struct request *blk_do_ordered(struct request_queue *q, struct request *rq)
}
/*
- * Start a new ordered sequence
+ * Start a new flush sequence
*/
- q->orderr = 0;
+ q->flush_err = 0;
q->ordered = q->next_ordered;
- q->ordseq |= QUEUE_ORDSEQ_STARTED;
+ q->flush_seq |= QUEUE_FSEQ_STARTED;
/*
* For an empty barrier, there's no actual BAR request, which
@@ -154,19 +152,19 @@ struct request *blk_do_ordered(struct request_queue *q, struct request *rq)
/* stash away the original request */
blk_dequeue_request(rq);
- q->orig_bar_rq = rq;
+ q->orig_flush_rq = rq;
if (!(q->ordered & QUEUE_ORDERED_DO_PREFLUSH))
- skip |= QUEUE_ORDSEQ_PREFLUSH;
+ skip |= QUEUE_FSEQ_PREFLUSH;
if (!(q->ordered & QUEUE_ORDERED_DO_BAR))
- skip |= QUEUE_ORDSEQ_BAR;
+ skip |= QUEUE_FSEQ_DATA;
if (!(q->ordered & QUEUE_ORDERED_DO_POSTFLUSH))
- skip |= QUEUE_ORDSEQ_POSTFLUSH;
+ skip |= QUEUE_FSEQ_POSTFLUSH;
/* complete skipped sequences and return the first sequence */
- return blk_ordered_complete_seq(q, skip, 0);
+ return blk_flush_complete_seq(q, skip, 0);
}
static void bio_end_empty_barrier(struct bio *bio, int err)
diff --git a/block/blk.h b/block/blk.h
index 08081e4..24b92bd 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -51,7 +51,7 @@ static inline void blk_clear_rq_complete(struct request *rq)
*/
#define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash))
-struct request *blk_do_ordered(struct request_queue *q, struct request *rq);
+struct request *blk_do_flush(struct request_queue *q, struct request *rq);
static inline struct request *__elv_next_request(struct request_queue *q)
{
@@ -60,7 +60,7 @@ static inline struct request *__elv_next_request(struct request_queue *q)
while (1) {
while (!list_empty(&q->queue_head)) {
rq = list_entry_rq(q->queue_head.next);
- rq = blk_do_ordered(q, rq);
+ rq = blk_do_flush(q, rq);
if (rq)
return rq;
}
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 20a3710..1cd83ec 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -357,13 +357,13 @@ struct request_queue
/*
* for flush operations
*/
+ unsigned int ordered, next_ordered;
unsigned int flush_flags;
-
- unsigned int ordered, next_ordered, ordseq;
- int orderr;
- struct request bar_rq;
- struct request *orig_bar_rq;
- struct list_head pending_barriers;
+ unsigned int flush_seq;
+ int flush_err;
+ struct request flush_rq;
+ struct request *orig_flush_rq;
+ struct list_head pending_flushes;
struct mutex sysfs_lock;
@@ -490,13 +490,13 @@ enum {
QUEUE_ORDERED_DO_FUA,
/*
- * Ordered operation sequence
+ * FLUSH/FUA sequences.
*/
- QUEUE_ORDSEQ_STARTED = (1 << 0), /* flushing in progress */
- QUEUE_ORDSEQ_PREFLUSH = (1 << 1), /* pre-flushing in progress */
- QUEUE_ORDSEQ_BAR = (1 << 2), /* barrier write in progress */
- QUEUE_ORDSEQ_POSTFLUSH = (1 << 3), /* post-flushing in progress */
- QUEUE_ORDSEQ_DONE = (1 << 4),
+ QUEUE_FSEQ_STARTED = (1 << 0), /* flushing in progress */
+ QUEUE_FSEQ_PREFLUSH = (1 << 1), /* pre-flushing in progress */
+ QUEUE_FSEQ_DATA = (1 << 2), /* data write in progress */
+ QUEUE_FSEQ_POSTFLUSH = (1 << 3), /* post-flushing in progress */
+ QUEUE_FSEQ_DONE = (1 << 4),
};
#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 09/41] block: rename barrier/ordered to flush
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo, Christoph Hellwig
With ordering requirements dropped, barrier and ordered are misnomers.
Now all block layer does is sequencing FLUSH and FUA. Rename them to
flush.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
---
block/blk-core.c | 21 +++++-----
block/blk-flush.c | 98 +++++++++++++++++++++++------------------------
block/blk.h | 4 +-
include/linux/blkdev.h | 24 ++++++------
4 files changed, 72 insertions(+), 75 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index d316662..8870ae4 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -136,7 +136,7 @@ static void req_bio_endio(struct request *rq, struct bio *bio,
{
struct request_queue *q = rq->q;
- if (&q->bar_rq != rq) {
+ if (&q->flush_rq != rq) {
if (error)
clear_bit(BIO_UPTODATE, &bio->bi_flags);
else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
@@ -160,13 +160,12 @@ static void req_bio_endio(struct request *rq, struct bio *bio,
if (bio->bi_size == 0)
bio_endio(bio, error);
} else {
-
/*
- * Okay, this is the barrier request in progress, just
- * record the error;
+ * Okay, this is the sequenced flush request in
+ * progress, just record the error;
*/
- if (error && !q->orderr)
- q->orderr = error;
+ if (error && !q->flush_err)
+ q->flush_err = error;
}
}
@@ -520,7 +519,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
init_timer(&q->unplug_timer);
setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q);
INIT_LIST_HEAD(&q->timeout_list);
- INIT_LIST_HEAD(&q->pending_barriers);
+ INIT_LIST_HEAD(&q->pending_flushes);
INIT_WORK(&q->unplug_work, blk_unplug_work);
kobject_init(&q->kobj, &blk_queue_ktype);
@@ -1764,11 +1763,11 @@ static void blk_account_io_completion(struct request *req, unsigned int bytes)
static void blk_account_io_done(struct request *req)
{
/*
- * Account IO completion. bar_rq isn't accounted as a normal
- * IO on queueing nor completion. Accounting the containing
- * request is enough.
+ * Account IO completion. flush_rq isn't accounted as a
+ * normal IO on queueing nor completion. Accounting the
+ * containing request is enough.
*/
- if (blk_do_io_stat(req) && req != &req->q->bar_rq) {
+ if (blk_do_io_stat(req) && req != &req->q->flush_rq) {
unsigned long duration = jiffies - req->start_time;
const int rw = rq_data_dir(req);
struct hd_struct *part;
diff --git a/block/blk-flush.c b/block/blk-flush.c
index e8b2e5c..dd87322 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -9,41 +9,38 @@
#include "blk.h"
-static struct request *queue_next_ordseq(struct request_queue *q);
+static struct request *queue_next_fseq(struct request_queue *q);
-/*
- * Cache flushing for ordered writes handling
- */
-unsigned blk_ordered_cur_seq(struct request_queue *q)
+unsigned blk_flush_cur_seq(struct request_queue *q)
{
- if (!q->ordseq)
+ if (!q->flush_seq)
return 0;
- return 1 << ffz(q->ordseq);
+ return 1 << ffz(q->flush_seq);
}
-static struct request *blk_ordered_complete_seq(struct request_queue *q,
- unsigned seq, int error)
+static struct request *blk_flush_complete_seq(struct request_queue *q,
+ unsigned seq, int error)
{
struct request *next_rq = NULL;
- if (error && !q->orderr)
- q->orderr = error;
+ if (error && !q->flush_err)
+ q->flush_err = error;
- BUG_ON(q->ordseq & seq);
- q->ordseq |= seq;
+ BUG_ON(q->flush_seq & seq);
+ q->flush_seq |= seq;
- if (blk_ordered_cur_seq(q) != QUEUE_ORDSEQ_DONE) {
- /* not complete yet, queue the next ordered sequence */
- next_rq = queue_next_ordseq(q);
+ if (blk_flush_cur_seq(q) != QUEUE_FSEQ_DONE) {
+ /* not complete yet, queue the next flush sequence */
+ next_rq = queue_next_fseq(q);
} else {
- /* complete this barrier request */
- __blk_end_request_all(q->orig_bar_rq, q->orderr);
- q->orig_bar_rq = NULL;
- q->ordseq = 0;
-
- /* dispatch the next barrier if there's one */
- if (!list_empty(&q->pending_barriers)) {
- next_rq = list_entry_rq(q->pending_barriers.next);
+ /* complete this flush request */
+ __blk_end_request_all(q->orig_flush_rq, q->flush_err);
+ q->orig_flush_rq = NULL;
+ q->flush_seq = 0;
+
+ /* dispatch the next flush if there's one */
+ if (!list_empty(&q->pending_flushes)) {
+ next_rq = list_entry_rq(q->pending_flushes.next);
list_move(&next_rq->queuelist, &q->queue_head);
}
}
@@ -53,19 +50,19 @@ static struct request *blk_ordered_complete_seq(struct request_queue *q,
static void pre_flush_end_io(struct request *rq, int error)
{
elv_completed_request(rq->q, rq);
- blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_PREFLUSH, error);
+ blk_flush_complete_seq(rq->q, QUEUE_FSEQ_PREFLUSH, error);
}
-static void bar_end_io(struct request *rq, int error)
+static void flush_data_end_io(struct request *rq, int error)
{
elv_completed_request(rq->q, rq);
- blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_BAR, error);
+ blk_flush_complete_seq(rq->q, QUEUE_FSEQ_DATA, error);
}
static void post_flush_end_io(struct request *rq, int error)
{
elv_completed_request(rq->q, rq);
- blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_POSTFLUSH, error);
+ blk_flush_complete_seq(rq->q, QUEUE_FSEQ_POSTFLUSH, error);
}
static void queue_flush(struct request_queue *q, struct request *rq,
@@ -74,34 +71,34 @@ static void queue_flush(struct request_queue *q, struct request *rq,
blk_rq_init(q, rq);
rq->cmd_type = REQ_TYPE_FS;
rq->cmd_flags = REQ_FLUSH;
- rq->rq_disk = q->orig_bar_rq->rq_disk;
+ rq->rq_disk = q->orig_flush_rq->rq_disk;
rq->end_io = end_io;
elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
}
-static struct request *queue_next_ordseq(struct request_queue *q)
+static struct request *queue_next_fseq(struct request_queue *q)
{
- struct request *rq = &q->bar_rq;
+ struct request *rq = &q->flush_rq;
- switch (blk_ordered_cur_seq(q)) {
- case QUEUE_ORDSEQ_PREFLUSH:
+ switch (blk_flush_cur_seq(q)) {
+ case QUEUE_FSEQ_PREFLUSH:
queue_flush(q, rq, pre_flush_end_io);
break;
- case QUEUE_ORDSEQ_BAR:
+ case QUEUE_FSEQ_DATA:
/* initialize proxy request and queue it */
blk_rq_init(q, rq);
- init_request_from_bio(rq, q->orig_bar_rq->bio);
+ init_request_from_bio(rq, q->orig_flush_rq->bio);
rq->cmd_flags &= ~REQ_HARDBARRIER;
if (q->ordered & QUEUE_ORDERED_DO_FUA)
rq->cmd_flags |= REQ_FUA;
- rq->end_io = bar_end_io;
+ rq->end_io = flush_data_end_io;
elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
break;
- case QUEUE_ORDSEQ_POSTFLUSH:
+ case QUEUE_FSEQ_POSTFLUSH:
queue_flush(q, rq, post_flush_end_io);
break;
@@ -111,19 +108,20 @@ static struct request *queue_next_ordseq(struct request_queue *q)
return rq;
}
-struct request *blk_do_ordered(struct request_queue *q, struct request *rq)
+struct request *blk_do_flush(struct request_queue *q, struct request *rq)
{
unsigned skip = 0;
if (!(rq->cmd_flags & REQ_HARDBARRIER))
return rq;
- if (q->ordseq) {
+ if (q->flush_seq) {
/*
- * Barrier is already in progress and they can't be
- * processed in parallel. Queue for later processing.
+ * Sequenced flush is already in progress and they
+ * can't be processed in parallel. Queue for later
+ * processing.
*/
- list_move_tail(&rq->queuelist, &q->pending_barriers);
+ list_move_tail(&rq->queuelist, &q->pending_flushes);
return NULL;
}
@@ -138,11 +136,11 @@ struct request *blk_do_ordered(struct request_queue *q, struct request *rq)
}
/*
- * Start a new ordered sequence
+ * Start a new flush sequence
*/
- q->orderr = 0;
+ q->flush_err = 0;
q->ordered = q->next_ordered;
- q->ordseq |= QUEUE_ORDSEQ_STARTED;
+ q->flush_seq |= QUEUE_FSEQ_STARTED;
/*
* For an empty barrier, there's no actual BAR request, which
@@ -154,19 +152,19 @@ struct request *blk_do_ordered(struct request_queue *q, struct request *rq)
/* stash away the original request */
blk_dequeue_request(rq);
- q->orig_bar_rq = rq;
+ q->orig_flush_rq = rq;
if (!(q->ordered & QUEUE_ORDERED_DO_PREFLUSH))
- skip |= QUEUE_ORDSEQ_PREFLUSH;
+ skip |= QUEUE_FSEQ_PREFLUSH;
if (!(q->ordered & QUEUE_ORDERED_DO_BAR))
- skip |= QUEUE_ORDSEQ_BAR;
+ skip |= QUEUE_FSEQ_DATA;
if (!(q->ordered & QUEUE_ORDERED_DO_POSTFLUSH))
- skip |= QUEUE_ORDSEQ_POSTFLUSH;
+ skip |= QUEUE_FSEQ_POSTFLUSH;
/* complete skipped sequences and return the first sequence */
- return blk_ordered_complete_seq(q, skip, 0);
+ return blk_flush_complete_seq(q, skip, 0);
}
static void bio_end_empty_barrier(struct bio *bio, int err)
diff --git a/block/blk.h b/block/blk.h
index 08081e4..24b92bd 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -51,7 +51,7 @@ static inline void blk_clear_rq_complete(struct request *rq)
*/
#define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash))
-struct request *blk_do_ordered(struct request_queue *q, struct request *rq);
+struct request *blk_do_flush(struct request_queue *q, struct request *rq);
static inline struct request *__elv_next_request(struct request_queue *q)
{
@@ -60,7 +60,7 @@ static inline struct request *__elv_next_request(struct request_queue *q)
while (1) {
while (!list_empty(&q->queue_head)) {
rq = list_entry_rq(q->queue_head.next);
- rq = blk_do_ordered(q, rq);
+ rq = blk_do_flush(q, rq);
if (rq)
return rq;
}
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 20a3710..1cd83ec 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -357,13 +357,13 @@ struct request_queue
/*
* for flush operations
*/
+ unsigned int ordered, next_ordered;
unsigned int flush_flags;
-
- unsigned int ordered, next_ordered, ordseq;
- int orderr;
- struct request bar_rq;
- struct request *orig_bar_rq;
- struct list_head pending_barriers;
+ unsigned int flush_seq;
+ int flush_err;
+ struct request flush_rq;
+ struct request *orig_flush_rq;
+ struct list_head pending_flushes;
struct mutex sysfs_lock;
@@ -490,13 +490,13 @@ enum {
QUEUE_ORDERED_DO_FUA,
/*
- * Ordered operation sequence
+ * FLUSH/FUA sequences.
*/
- QUEUE_ORDSEQ_STARTED = (1 << 0), /* flushing in progress */
- QUEUE_ORDSEQ_PREFLUSH = (1 << 1), /* pre-flushing in progress */
- QUEUE_ORDSEQ_BAR = (1 << 2), /* barrier write in progress */
- QUEUE_ORDSEQ_POSTFLUSH = (1 << 3), /* post-flushing in progress */
- QUEUE_ORDSEQ_DONE = (1 << 4),
+ QUEUE_FSEQ_STARTED = (1 << 0), /* flushing in progress */
+ QUEUE_FSEQ_PREFLUSH = (1 << 1), /* pre-flushing in progress */
+ QUEUE_FSEQ_DATA = (1 << 2), /* data write in progress */
+ QUEUE_FSEQ_POSTFLUSH = (1 << 3), /* post-flushing in progress */
+ QUEUE_FSEQ_DONE = (1 << 4),
};
#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 09/41] block: rename barrier/ordered to flush
2010-09-03 10:29 ` Tejun Heo
` (15 preceding siblings ...)
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo, Christoph Hellwig
With ordering requirements dropped, barrier and ordered are misnomers.
Now all block layer does is sequencing FLUSH and FUA. Rename them to
flush.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
---
block/blk-core.c | 21 +++++-----
block/blk-flush.c | 98 +++++++++++++++++++++++------------------------
block/blk.h | 4 +-
include/linux/blkdev.h | 24 ++++++------
4 files changed, 72 insertions(+), 75 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index d316662..8870ae4 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -136,7 +136,7 @@ static void req_bio_endio(struct request *rq, struct bio *bio,
{
struct request_queue *q = rq->q;
- if (&q->bar_rq != rq) {
+ if (&q->flush_rq != rq) {
if (error)
clear_bit(BIO_UPTODATE, &bio->bi_flags);
else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
@@ -160,13 +160,12 @@ static void req_bio_endio(struct request *rq, struct bio *bio,
if (bio->bi_size == 0)
bio_endio(bio, error);
} else {
-
/*
- * Okay, this is the barrier request in progress, just
- * record the error;
+ * Okay, this is the sequenced flush request in
+ * progress, just record the error;
*/
- if (error && !q->orderr)
- q->orderr = error;
+ if (error && !q->flush_err)
+ q->flush_err = error;
}
}
@@ -520,7 +519,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
init_timer(&q->unplug_timer);
setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q);
INIT_LIST_HEAD(&q->timeout_list);
- INIT_LIST_HEAD(&q->pending_barriers);
+ INIT_LIST_HEAD(&q->pending_flushes);
INIT_WORK(&q->unplug_work, blk_unplug_work);
kobject_init(&q->kobj, &blk_queue_ktype);
@@ -1764,11 +1763,11 @@ static void blk_account_io_completion(struct request *req, unsigned int bytes)
static void blk_account_io_done(struct request *req)
{
/*
- * Account IO completion. bar_rq isn't accounted as a normal
- * IO on queueing nor completion. Accounting the containing
- * request is enough.
+ * Account IO completion. flush_rq isn't accounted as a
+ * normal IO on queueing nor completion. Accounting the
+ * containing request is enough.
*/
- if (blk_do_io_stat(req) && req != &req->q->bar_rq) {
+ if (blk_do_io_stat(req) && req != &req->q->flush_rq) {
unsigned long duration = jiffies - req->start_time;
const int rw = rq_data_dir(req);
struct hd_struct *part;
diff --git a/block/blk-flush.c b/block/blk-flush.c
index e8b2e5c..dd87322 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -9,41 +9,38 @@
#include "blk.h"
-static struct request *queue_next_ordseq(struct request_queue *q);
+static struct request *queue_next_fseq(struct request_queue *q);
-/*
- * Cache flushing for ordered writes handling
- */
-unsigned blk_ordered_cur_seq(struct request_queue *q)
+unsigned blk_flush_cur_seq(struct request_queue *q)
{
- if (!q->ordseq)
+ if (!q->flush_seq)
return 0;
- return 1 << ffz(q->ordseq);
+ return 1 << ffz(q->flush_seq);
}
-static struct request *blk_ordered_complete_seq(struct request_queue *q,
- unsigned seq, int error)
+static struct request *blk_flush_complete_seq(struct request_queue *q,
+ unsigned seq, int error)
{
struct request *next_rq = NULL;
- if (error && !q->orderr)
- q->orderr = error;
+ if (error && !q->flush_err)
+ q->flush_err = error;
- BUG_ON(q->ordseq & seq);
- q->ordseq |= seq;
+ BUG_ON(q->flush_seq & seq);
+ q->flush_seq |= seq;
- if (blk_ordered_cur_seq(q) != QUEUE_ORDSEQ_DONE) {
- /* not complete yet, queue the next ordered sequence */
- next_rq = queue_next_ordseq(q);
+ if (blk_flush_cur_seq(q) != QUEUE_FSEQ_DONE) {
+ /* not complete yet, queue the next flush sequence */
+ next_rq = queue_next_fseq(q);
} else {
- /* complete this barrier request */
- __blk_end_request_all(q->orig_bar_rq, q->orderr);
- q->orig_bar_rq = NULL;
- q->ordseq = 0;
-
- /* dispatch the next barrier if there's one */
- if (!list_empty(&q->pending_barriers)) {
- next_rq = list_entry_rq(q->pending_barriers.next);
+ /* complete this flush request */
+ __blk_end_request_all(q->orig_flush_rq, q->flush_err);
+ q->orig_flush_rq = NULL;
+ q->flush_seq = 0;
+
+ /* dispatch the next flush if there's one */
+ if (!list_empty(&q->pending_flushes)) {
+ next_rq = list_entry_rq(q->pending_flushes.next);
list_move(&next_rq->queuelist, &q->queue_head);
}
}
@@ -53,19 +50,19 @@ static struct request *blk_ordered_complete_seq(struct request_queue *q,
static void pre_flush_end_io(struct request *rq, int error)
{
elv_completed_request(rq->q, rq);
- blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_PREFLUSH, error);
+ blk_flush_complete_seq(rq->q, QUEUE_FSEQ_PREFLUSH, error);
}
-static void bar_end_io(struct request *rq, int error)
+static void flush_data_end_io(struct request *rq, int error)
{
elv_completed_request(rq->q, rq);
- blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_BAR, error);
+ blk_flush_complete_seq(rq->q, QUEUE_FSEQ_DATA, error);
}
static void post_flush_end_io(struct request *rq, int error)
{
elv_completed_request(rq->q, rq);
- blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_POSTFLUSH, error);
+ blk_flush_complete_seq(rq->q, QUEUE_FSEQ_POSTFLUSH, error);
}
static void queue_flush(struct request_queue *q, struct request *rq,
@@ -74,34 +71,34 @@ static void queue_flush(struct request_queue *q, struct request *rq,
blk_rq_init(q, rq);
rq->cmd_type = REQ_TYPE_FS;
rq->cmd_flags = REQ_FLUSH;
- rq->rq_disk = q->orig_bar_rq->rq_disk;
+ rq->rq_disk = q->orig_flush_rq->rq_disk;
rq->end_io = end_io;
elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
}
-static struct request *queue_next_ordseq(struct request_queue *q)
+static struct request *queue_next_fseq(struct request_queue *q)
{
- struct request *rq = &q->bar_rq;
+ struct request *rq = &q->flush_rq;
- switch (blk_ordered_cur_seq(q)) {
- case QUEUE_ORDSEQ_PREFLUSH:
+ switch (blk_flush_cur_seq(q)) {
+ case QUEUE_FSEQ_PREFLUSH:
queue_flush(q, rq, pre_flush_end_io);
break;
- case QUEUE_ORDSEQ_BAR:
+ case QUEUE_FSEQ_DATA:
/* initialize proxy request and queue it */
blk_rq_init(q, rq);
- init_request_from_bio(rq, q->orig_bar_rq->bio);
+ init_request_from_bio(rq, q->orig_flush_rq->bio);
rq->cmd_flags &= ~REQ_HARDBARRIER;
if (q->ordered & QUEUE_ORDERED_DO_FUA)
rq->cmd_flags |= REQ_FUA;
- rq->end_io = bar_end_io;
+ rq->end_io = flush_data_end_io;
elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
break;
- case QUEUE_ORDSEQ_POSTFLUSH:
+ case QUEUE_FSEQ_POSTFLUSH:
queue_flush(q, rq, post_flush_end_io);
break;
@@ -111,19 +108,20 @@ static struct request *queue_next_ordseq(struct request_queue *q)
return rq;
}
-struct request *blk_do_ordered(struct request_queue *q, struct request *rq)
+struct request *blk_do_flush(struct request_queue *q, struct request *rq)
{
unsigned skip = 0;
if (!(rq->cmd_flags & REQ_HARDBARRIER))
return rq;
- if (q->ordseq) {
+ if (q->flush_seq) {
/*
- * Barrier is already in progress and they can't be
- * processed in parallel. Queue for later processing.
+ * Sequenced flush is already in progress and they
+ * can't be processed in parallel. Queue for later
+ * processing.
*/
- list_move_tail(&rq->queuelist, &q->pending_barriers);
+ list_move_tail(&rq->queuelist, &q->pending_flushes);
return NULL;
}
@@ -138,11 +136,11 @@ struct request *blk_do_ordered(struct request_queue *q, struct request *rq)
}
/*
- * Start a new ordered sequence
+ * Start a new flush sequence
*/
- q->orderr = 0;
+ q->flush_err = 0;
q->ordered = q->next_ordered;
- q->ordseq |= QUEUE_ORDSEQ_STARTED;
+ q->flush_seq |= QUEUE_FSEQ_STARTED;
/*
* For an empty barrier, there's no actual BAR request, which
@@ -154,19 +152,19 @@ struct request *blk_do_ordered(struct request_queue *q, struct request *rq)
/* stash away the original request */
blk_dequeue_request(rq);
- q->orig_bar_rq = rq;
+ q->orig_flush_rq = rq;
if (!(q->ordered & QUEUE_ORDERED_DO_PREFLUSH))
- skip |= QUEUE_ORDSEQ_PREFLUSH;
+ skip |= QUEUE_FSEQ_PREFLUSH;
if (!(q->ordered & QUEUE_ORDERED_DO_BAR))
- skip |= QUEUE_ORDSEQ_BAR;
+ skip |= QUEUE_FSEQ_DATA;
if (!(q->ordered & QUEUE_ORDERED_DO_POSTFLUSH))
- skip |= QUEUE_ORDSEQ_POSTFLUSH;
+ skip |= QUEUE_FSEQ_POSTFLUSH;
/* complete skipped sequences and return the first sequence */
- return blk_ordered_complete_seq(q, skip, 0);
+ return blk_flush_complete_seq(q, skip, 0);
}
static void bio_end_empty_barrier(struct bio *bio, int err)
diff --git a/block/blk.h b/block/blk.h
index 08081e4..24b92bd 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -51,7 +51,7 @@ static inline void blk_clear_rq_complete(struct request *rq)
*/
#define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash))
-struct request *blk_do_ordered(struct request_queue *q, struct request *rq);
+struct request *blk_do_flush(struct request_queue *q, struct request *rq);
static inline struct request *__elv_next_request(struct request_queue *q)
{
@@ -60,7 +60,7 @@ static inline struct request *__elv_next_request(struct request_queue *q)
while (1) {
while (!list_empty(&q->queue_head)) {
rq = list_entry_rq(q->queue_head.next);
- rq = blk_do_ordered(q, rq);
+ rq = blk_do_flush(q, rq);
if (rq)
return rq;
}
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 20a3710..1cd83ec 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -357,13 +357,13 @@ struct request_queue
/*
* for flush operations
*/
+ unsigned int ordered, next_ordered;
unsigned int flush_flags;
-
- unsigned int ordered, next_ordered, ordseq;
- int orderr;
- struct request bar_rq;
- struct request *orig_bar_rq;
- struct list_head pending_barriers;
+ unsigned int flush_seq;
+ int flush_err;
+ struct request flush_rq;
+ struct request *orig_flush_rq;
+ struct list_head pending_flushes;
struct mutex sysfs_lock;
@@ -490,13 +490,13 @@ enum {
QUEUE_ORDERED_DO_FUA,
/*
- * Ordered operation sequence
+ * FLUSH/FUA sequences.
*/
- QUEUE_ORDSEQ_STARTED = (1 << 0), /* flushing in progress */
- QUEUE_ORDSEQ_PREFLUSH = (1 << 1), /* pre-flushing in progress */
- QUEUE_ORDSEQ_BAR = (1 << 2), /* barrier write in progress */
- QUEUE_ORDSEQ_POSTFLUSH = (1 << 3), /* post-flushing in progress */
- QUEUE_ORDSEQ_DONE = (1 << 4),
+ QUEUE_FSEQ_STARTED = (1 << 0), /* flushing in progress */
+ QUEUE_FSEQ_PREFLUSH = (1 << 1), /* pre-flushing in progress */
+ QUEUE_FSEQ_DATA = (1 << 2), /* data write in progress */
+ QUEUE_FSEQ_POSTFLUSH = (1 << 3), /* post-flushing in progress */
+ QUEUE_FSEQ_DONE = (1 << 4),
};
#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 10/41] block: implement REQ_FLUSH/FUA based interface for FLUSH/FUA requests
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo, Christoph Hellwig
Now that the backend conversion is complete, export sequenced
FLUSH/FUA capability through REQ_FLUSH/FUA flags. REQ_FLUSH means the
device cache should be flushed before executing the request. REQ_FUA
means that the data in the request should be on non-volatile media on
completion.
Block layer will choose the correct way of implementing the semantics
and execute it. The request may be passed to the device directly if
the device can handle it; otherwise, it will be sequenced using one or
more proxy requests. Devices will never see REQ_FLUSH and/or FUA
which it doesn't support.
Also, unlike the original REQ_HARDBARRIER, REQ_FLUSH/FUA requests are
never failed with -EOPNOTSUPP. If the underlying device doesn't
support FLUSH/FUA, the block layer simply make those noop. IOW, it no
longer distinguishes between writeback cache which doesn't support
cache flush and writethrough/no cache. Devices which have WB cache
w/o flush are very difficult to come by these days and there's nothing
much we can do anyway, so it doesn't make sense to require everyone to
implement -EOPNOTSUPP handling. This will simplify filesystems and
block drivers as they can drop -EOPNOTSUPP retry logic for barriers.
* QUEUE_ORDERED_* are removed and QUEUE_FSEQ_* are moved into
blk-flush.c.
* REQ_FLUSH w/o data can also be directly passed to drivers without
sequencing but some drivers assume that zero length requests don't
have rq->bio which isn't true for these requests requiring the use
of proxy requests.
* REQ_COMMON_MASK now includes REQ_FLUSH | REQ_FUA so that they are
copied from bio to request.
* WRITE_BARRIER is marked deprecated and WRITE_FLUSH, WRITE_FUA and
WRITE_FLUSH_FUA are added.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
---
block/blk-core.c | 2 +-
block/blk-flush.c | 85 +++++++++++++++++++++++--------------------
block/blk.h | 3 ++
include/linux/blk_types.h | 2 +-
include/linux/blkdev.h | 38 +------------------
include/linux/buffer_head.h | 2 +-
include/linux/fs.h | 19 +++++++---
7 files changed, 67 insertions(+), 84 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 8870ae4..18455c4 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1204,7 +1204,7 @@ static int __make_request(struct request_queue *q, struct bio *bio)
spin_lock_irq(q->queue_lock);
- if (bio->bi_rw & REQ_HARDBARRIER) {
+ if (bio->bi_rw & (REQ_FLUSH | REQ_FUA)) {
where = ELEVATOR_INSERT_FRONT;
goto get_rq;
}
diff --git a/block/blk-flush.c b/block/blk-flush.c
index dd87322..452c552 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -1,5 +1,5 @@
/*
- * Functions related to barrier IO handling
+ * Functions to sequence FLUSH and FUA writes.
*/
#include <linux/kernel.h>
#include <linux/module.h>
@@ -9,6 +9,15 @@
#include "blk.h"
+/* FLUSH/FUA sequences */
+enum {
+ QUEUE_FSEQ_STARTED = (1 << 0), /* flushing in progress */
+ QUEUE_FSEQ_PREFLUSH = (1 << 1), /* pre-flushing in progress */
+ QUEUE_FSEQ_DATA = (1 << 2), /* data write in progress */
+ QUEUE_FSEQ_POSTFLUSH = (1 << 3), /* post-flushing in progress */
+ QUEUE_FSEQ_DONE = (1 << 4),
+};
+
static struct request *queue_next_fseq(struct request_queue *q);
unsigned blk_flush_cur_seq(struct request_queue *q)
@@ -79,6 +88,7 @@ static void queue_flush(struct request_queue *q, struct request *rq,
static struct request *queue_next_fseq(struct request_queue *q)
{
+ struct request *orig_rq = q->orig_flush_rq;
struct request *rq = &q->flush_rq;
switch (blk_flush_cur_seq(q)) {
@@ -87,12 +97,11 @@ static struct request *queue_next_fseq(struct request_queue *q)
break;
case QUEUE_FSEQ_DATA:
- /* initialize proxy request and queue it */
+ /* initialize proxy request, inherit FLUSH/FUA and queue it */
blk_rq_init(q, rq);
- init_request_from_bio(rq, q->orig_flush_rq->bio);
- rq->cmd_flags &= ~REQ_HARDBARRIER;
- if (q->ordered & QUEUE_ORDERED_DO_FUA)
- rq->cmd_flags |= REQ_FUA;
+ init_request_from_bio(rq, orig_rq->bio);
+ rq->cmd_flags &= ~(REQ_FLUSH | REQ_FUA);
+ rq->cmd_flags |= orig_rq->cmd_flags & (REQ_FLUSH | REQ_FUA);
rq->end_io = flush_data_end_io;
elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
@@ -110,60 +119,58 @@ static struct request *queue_next_fseq(struct request_queue *q)
struct request *blk_do_flush(struct request_queue *q, struct request *rq)
{
+ unsigned int fflags = q->flush_flags; /* may change, cache it */
+ bool has_flush = fflags & REQ_FLUSH, has_fua = fflags & REQ_FUA;
+ bool do_preflush = has_flush && (rq->cmd_flags & REQ_FLUSH);
+ bool do_postflush = has_flush && !has_fua && (rq->cmd_flags & REQ_FUA);
unsigned skip = 0;
- if (!(rq->cmd_flags & REQ_HARDBARRIER))
+ /*
+ * Special case. If there's data but flush is not necessary,
+ * the request can be issued directly.
+ *
+ * Flush w/o data should be able to be issued directly too but
+ * currently some drivers assume that rq->bio contains
+ * non-zero data if it isn't NULL and empty FLUSH requests
+ * getting here usually have bio's without data.
+ */
+ if (blk_rq_sectors(rq) && !do_preflush && !do_postflush) {
+ rq->cmd_flags &= ~REQ_FLUSH;
+ if (!has_fua)
+ rq->cmd_flags &= ~REQ_FUA;
return rq;
+ }
+ /*
+ * Sequenced flushes can't be processed in parallel. If
+ * another one is already in progress, queue for later
+ * processing.
+ */
if (q->flush_seq) {
- /*
- * Sequenced flush is already in progress and they
- * can't be processed in parallel. Queue for later
- * processing.
- */
list_move_tail(&rq->queuelist, &q->pending_flushes);
return NULL;
}
- if (unlikely(q->next_ordered == QUEUE_ORDERED_NONE)) {
- /*
- * Queue ordering not supported. Terminate
- * with prejudice.
- */
- blk_dequeue_request(rq);
- __blk_end_request_all(rq, -EOPNOTSUPP);
- return NULL;
- }
-
/*
* Start a new flush sequence
*/
q->flush_err = 0;
- q->ordered = q->next_ordered;
q->flush_seq |= QUEUE_FSEQ_STARTED;
- /*
- * For an empty barrier, there's no actual BAR request, which
- * in turn makes POSTFLUSH unnecessary. Mask them off.
- */
- if (!blk_rq_sectors(rq))
- q->ordered &= ~(QUEUE_ORDERED_DO_BAR |
- QUEUE_ORDERED_DO_POSTFLUSH);
-
- /* stash away the original request */
+ /* adjust FLUSH/FUA of the original request and stash it away */
+ rq->cmd_flags &= ~REQ_FLUSH;
+ if (!has_fua)
+ rq->cmd_flags &= ~REQ_FUA;
blk_dequeue_request(rq);
q->orig_flush_rq = rq;
- if (!(q->ordered & QUEUE_ORDERED_DO_PREFLUSH))
+ /* skip unneded sequences and return the first one */
+ if (!do_preflush)
skip |= QUEUE_FSEQ_PREFLUSH;
-
- if (!(q->ordered & QUEUE_ORDERED_DO_BAR))
+ if (!blk_rq_sectors(rq))
skip |= QUEUE_FSEQ_DATA;
-
- if (!(q->ordered & QUEUE_ORDERED_DO_POSTFLUSH))
+ if (!do_postflush)
skip |= QUEUE_FSEQ_POSTFLUSH;
-
- /* complete skipped sequences and return the first sequence */
return blk_flush_complete_seq(q, skip, 0);
}
diff --git a/block/blk.h b/block/blk.h
index 24b92bd..a09c18b 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -60,6 +60,9 @@ static inline struct request *__elv_next_request(struct request_queue *q)
while (1) {
while (!list_empty(&q->queue_head)) {
rq = list_entry_rq(q->queue_head.next);
+ if (!(rq->cmd_flags & (REQ_FLUSH | REQ_FUA)) ||
+ rq == &q->flush_rq)
+ return rq;
rq = blk_do_flush(q, rq);
if (rq)
return rq;
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 9192282..1797994 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -167,7 +167,7 @@ enum rq_flag_bits {
(REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
#define REQ_COMMON_MASK \
(REQ_WRITE | REQ_FAILFAST_MASK | REQ_HARDBARRIER | REQ_SYNC | \
- REQ_META| REQ_DISCARD | REQ_NOIDLE)
+ REQ_META | REQ_DISCARD | REQ_NOIDLE | REQ_FLUSH | REQ_FUA)
#define REQ_UNPLUG (1 << __REQ_UNPLUG)
#define REQ_RAHEAD (1 << __REQ_RAHEAD)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 1cd83ec..8ef705f 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -357,7 +357,6 @@ struct request_queue
/*
* for flush operations
*/
- unsigned int ordered, next_ordered;
unsigned int flush_flags;
unsigned int flush_seq;
int flush_err;
@@ -465,40 +464,6 @@ static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
__clear_bit(flag, &q->queue_flags);
}
-enum {
- /*
- * Hardbarrier is supported with one of the following methods.
- *
- * NONE : hardbarrier unsupported
- * DRAIN : ordering by draining is enough
- * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
- * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
- */
- QUEUE_ORDERED_DO_PREFLUSH = 0x10,
- QUEUE_ORDERED_DO_BAR = 0x20,
- QUEUE_ORDERED_DO_POSTFLUSH = 0x40,
- QUEUE_ORDERED_DO_FUA = 0x80,
-
- QUEUE_ORDERED_NONE = 0x00,
-
- QUEUE_ORDERED_DRAIN = QUEUE_ORDERED_DO_BAR,
- QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
- QUEUE_ORDERED_DO_PREFLUSH |
- QUEUE_ORDERED_DO_POSTFLUSH,
- QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN |
- QUEUE_ORDERED_DO_PREFLUSH |
- QUEUE_ORDERED_DO_FUA,
-
- /*
- * FLUSH/FUA sequences.
- */
- QUEUE_FSEQ_STARTED = (1 << 0), /* flushing in progress */
- QUEUE_FSEQ_PREFLUSH = (1 << 1), /* pre-flushing in progress */
- QUEUE_FSEQ_DATA = (1 << 2), /* data write in progress */
- QUEUE_FSEQ_POSTFLUSH = (1 << 3), /* post-flushing in progress */
- QUEUE_FSEQ_DONE = (1 << 4),
-};
-
#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
#define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
@@ -578,7 +543,8 @@ static inline void blk_clear_queue_full(struct request_queue *q, int sync)
* it already be started by driver.
*/
#define RQ_NOMERGE_FLAGS \
- (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
+ (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER | \
+ REQ_FLUSH | REQ_FUA)
#define rq_mergeable(rq) \
(!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
(((rq)->cmd_flags & REQ_DISCARD) || \
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index ec94c12..fc999f5 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -32,7 +32,7 @@ enum bh_state_bits {
BH_Delay, /* Buffer is not yet allocated on disk */
BH_Boundary, /* Block is followed by a discontiguity */
BH_Write_EIO, /* I/O error on write */
- BH_Eopnotsupp, /* operation not supported (barrier) */
+ BH_Eopnotsupp, /* DEPRECATED: operation not supported (barrier) */
BH_Unwritten, /* Buffer is allocated on disk but not written */
BH_Quiet, /* Buffer Error Prinks to be quiet */
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 76041b6..352c486 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -135,12 +135,13 @@ struct inodes_stat_t {
* immediately after submission. The write equivalent
* of READ_SYNC.
* WRITE_ODIRECT_PLUG Special case write for O_DIRECT only.
- * WRITE_BARRIER Like WRITE_SYNC, but tells the block layer that all
- * previously submitted writes must be safely on storage
- * before this one is started. Also guarantees that when
- * this write is complete, it itself is also safely on
- * storage. Prevents reordering of writes on both sides
- * of this IO.
+ * WRITE_BARRIER DEPRECATED. Always fails. Use FLUSH/FUA instead.
+ * WRITE_FLUSH Like WRITE_SYNC but with preceding cache flush.
+ * WRITE_FUA Like WRITE_SYNC but data is guaranteed to be on
+ * non-volatile media on completion.
+ * WRITE_FLUSH_FUA Combination of WRITE_FLUSH and FUA. The IO is preceded
+ * by a cache flush and data is guaranteed to be on
+ * non-volatile media on completion.
*
*/
#define RW_MASK REQ_WRITE
@@ -158,6 +159,12 @@ struct inodes_stat_t {
#define WRITE_META (WRITE | REQ_META)
#define WRITE_BARRIER (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
REQ_HARDBARRIER)
+#define WRITE_FLUSH (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
+ REQ_FLUSH)
+#define WRITE_FUA (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
+ REQ_FUA)
+#define WRITE_FLUSH_FUA (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
+ REQ_FLUSH | REQ_FUA)
/*
* These aren't really reads or writes, they pass down information about
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 10/41] block: implement REQ_FLUSH/FUA based interface for FLUSH/FUA requests
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo, Christoph Hellwig
Now that the backend conversion is complete, export sequenced
FLUSH/FUA capability through REQ_FLUSH/FUA flags. REQ_FLUSH means the
device cache should be flushed before executing the request. REQ_FUA
means that the data in the request should be on non-volatile media on
completion.
Block layer will choose the correct way of implementing the semantics
and execute it. The request may be passed to the device directly if
the device can handle it; otherwise, it will be sequenced using one or
more proxy requests. Devices will never see REQ_FLUSH and/or FUA
which it doesn't support.
Also, unlike the original REQ_HARDBARRIER, REQ_FLUSH/FUA requests are
never failed with -EOPNOTSUPP. If the underlying device doesn't
support FLUSH/FUA, the block layer simply make those noop. IOW, it no
longer distinguishes between writeback cache which doesn't support
cache flush and writethrough/no cache. Devices which have WB cache
w/o flush are very difficult to come by these days and there's nothing
much we can do anyway, so it doesn't make sense to require everyone to
implement -EOPNOTSUPP handling. This will simplify filesystems and
block drivers as they can drop -EOPNOTSUPP retry logic for barriers.
* QUEUE_ORDERED_* are removed and QUEUE_FSEQ_* are moved into
blk-flush.c.
* REQ_FLUSH w/o data can also be directly passed to drivers without
sequencing but some drivers assume that zero length requests don't
have rq->bio which isn't true for these requests requiring the use
of proxy requests.
* REQ_COMMON_MASK now includes REQ_FLUSH | REQ_FUA so that they are
copied from bio to request.
* WRITE_BARRIER is marked deprecated and WRITE_FLUSH, WRITE_FUA and
WRITE_FLUSH_FUA are added.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
---
block/blk-core.c | 2 +-
block/blk-flush.c | 85 +++++++++++++++++++++++--------------------
block/blk.h | 3 ++
include/linux/blk_types.h | 2 +-
include/linux/blkdev.h | 38 +------------------
include/linux/buffer_head.h | 2 +-
include/linux/fs.h | 19 +++++++---
7 files changed, 67 insertions(+), 84 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 8870ae4..18455c4 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1204,7 +1204,7 @@ static int __make_request(struct request_queue *q, struct bio *bio)
spin_lock_irq(q->queue_lock);
- if (bio->bi_rw & REQ_HARDBARRIER) {
+ if (bio->bi_rw & (REQ_FLUSH | REQ_FUA)) {
where = ELEVATOR_INSERT_FRONT;
goto get_rq;
}
diff --git a/block/blk-flush.c b/block/blk-flush.c
index dd87322..452c552 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -1,5 +1,5 @@
/*
- * Functions related to barrier IO handling
+ * Functions to sequence FLUSH and FUA writes.
*/
#include <linux/kernel.h>
#include <linux/module.h>
@@ -9,6 +9,15 @@
#include "blk.h"
+/* FLUSH/FUA sequences */
+enum {
+ QUEUE_FSEQ_STARTED = (1 << 0), /* flushing in progress */
+ QUEUE_FSEQ_PREFLUSH = (1 << 1), /* pre-flushing in progress */
+ QUEUE_FSEQ_DATA = (1 << 2), /* data write in progress */
+ QUEUE_FSEQ_POSTFLUSH = (1 << 3), /* post-flushing in progress */
+ QUEUE_FSEQ_DONE = (1 << 4),
+};
+
static struct request *queue_next_fseq(struct request_queue *q);
unsigned blk_flush_cur_seq(struct request_queue *q)
@@ -79,6 +88,7 @@ static void queue_flush(struct request_queue *q, struct request *rq,
static struct request *queue_next_fseq(struct request_queue *q)
{
+ struct request *orig_rq = q->orig_flush_rq;
struct request *rq = &q->flush_rq;
switch (blk_flush_cur_seq(q)) {
@@ -87,12 +97,11 @@ static struct request *queue_next_fseq(struct request_queue *q)
break;
case QUEUE_FSEQ_DATA:
- /* initialize proxy request and queue it */
+ /* initialize proxy request, inherit FLUSH/FUA and queue it */
blk_rq_init(q, rq);
- init_request_from_bio(rq, q->orig_flush_rq->bio);
- rq->cmd_flags &= ~REQ_HARDBARRIER;
- if (q->ordered & QUEUE_ORDERED_DO_FUA)
- rq->cmd_flags |= REQ_FUA;
+ init_request_from_bio(rq, orig_rq->bio);
+ rq->cmd_flags &= ~(REQ_FLUSH | REQ_FUA);
+ rq->cmd_flags |= orig_rq->cmd_flags & (REQ_FLUSH | REQ_FUA);
rq->end_io = flush_data_end_io;
elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
@@ -110,60 +119,58 @@ static struct request *queue_next_fseq(struct request_queue *q)
struct request *blk_do_flush(struct request_queue *q, struct request *rq)
{
+ unsigned int fflags = q->flush_flags; /* may change, cache it */
+ bool has_flush = fflags & REQ_FLUSH, has_fua = fflags & REQ_FUA;
+ bool do_preflush = has_flush && (rq->cmd_flags & REQ_FLUSH);
+ bool do_postflush = has_flush && !has_fua && (rq->cmd_flags & REQ_FUA);
unsigned skip = 0;
- if (!(rq->cmd_flags & REQ_HARDBARRIER))
+ /*
+ * Special case. If there's data but flush is not necessary,
+ * the request can be issued directly.
+ *
+ * Flush w/o data should be able to be issued directly too but
+ * currently some drivers assume that rq->bio contains
+ * non-zero data if it isn't NULL and empty FLUSH requests
+ * getting here usually have bio's without data.
+ */
+ if (blk_rq_sectors(rq) && !do_preflush && !do_postflush) {
+ rq->cmd_flags &= ~REQ_FLUSH;
+ if (!has_fua)
+ rq->cmd_flags &= ~REQ_FUA;
return rq;
+ }
+ /*
+ * Sequenced flushes can't be processed in parallel. If
+ * another one is already in progress, queue for later
+ * processing.
+ */
if (q->flush_seq) {
- /*
- * Sequenced flush is already in progress and they
- * can't be processed in parallel. Queue for later
- * processing.
- */
list_move_tail(&rq->queuelist, &q->pending_flushes);
return NULL;
}
- if (unlikely(q->next_ordered == QUEUE_ORDERED_NONE)) {
- /*
- * Queue ordering not supported. Terminate
- * with prejudice.
- */
- blk_dequeue_request(rq);
- __blk_end_request_all(rq, -EOPNOTSUPP);
- return NULL;
- }
-
/*
* Start a new flush sequence
*/
q->flush_err = 0;
- q->ordered = q->next_ordered;
q->flush_seq |= QUEUE_FSEQ_STARTED;
- /*
- * For an empty barrier, there's no actual BAR request, which
- * in turn makes POSTFLUSH unnecessary. Mask them off.
- */
- if (!blk_rq_sectors(rq))
- q->ordered &= ~(QUEUE_ORDERED_DO_BAR |
- QUEUE_ORDERED_DO_POSTFLUSH);
-
- /* stash away the original request */
+ /* adjust FLUSH/FUA of the original request and stash it away */
+ rq->cmd_flags &= ~REQ_FLUSH;
+ if (!has_fua)
+ rq->cmd_flags &= ~REQ_FUA;
blk_dequeue_request(rq);
q->orig_flush_rq = rq;
- if (!(q->ordered & QUEUE_ORDERED_DO_PREFLUSH))
+ /* skip unneded sequences and return the first one */
+ if (!do_preflush)
skip |= QUEUE_FSEQ_PREFLUSH;
-
- if (!(q->ordered & QUEUE_ORDERED_DO_BAR))
+ if (!blk_rq_sectors(rq))
skip |= QUEUE_FSEQ_DATA;
-
- if (!(q->ordered & QUEUE_ORDERED_DO_POSTFLUSH))
+ if (!do_postflush)
skip |= QUEUE_FSEQ_POSTFLUSH;
-
- /* complete skipped sequences and return the first sequence */
return blk_flush_complete_seq(q, skip, 0);
}
diff --git a/block/blk.h b/block/blk.h
index 24b92bd..a09c18b 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -60,6 +60,9 @@ static inline struct request *__elv_next_request(struct request_queue *q)
while (1) {
while (!list_empty(&q->queue_head)) {
rq = list_entry_rq(q->queue_head.next);
+ if (!(rq->cmd_flags & (REQ_FLUSH | REQ_FUA)) ||
+ rq == &q->flush_rq)
+ return rq;
rq = blk_do_flush(q, rq);
if (rq)
return rq;
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 9192282..1797994 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -167,7 +167,7 @@ enum rq_flag_bits {
(REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
#define REQ_COMMON_MASK \
(REQ_WRITE | REQ_FAILFAST_MASK | REQ_HARDBARRIER | REQ_SYNC | \
- REQ_META| REQ_DISCARD | REQ_NOIDLE)
+ REQ_META | REQ_DISCARD | REQ_NOIDLE | REQ_FLUSH | REQ_FUA)
#define REQ_UNPLUG (1 << __REQ_UNPLUG)
#define REQ_RAHEAD (1 << __REQ_RAHEAD)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 1cd83ec..8ef705f 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -357,7 +357,6 @@ struct request_queue
/*
* for flush operations
*/
- unsigned int ordered, next_ordered;
unsigned int flush_flags;
unsigned int flush_seq;
int flush_err;
@@ -465,40 +464,6 @@ static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
__clear_bit(flag, &q->queue_flags);
}
-enum {
- /*
- * Hardbarrier is supported with one of the following methods.
- *
- * NONE : hardbarrier unsupported
- * DRAIN : ordering by draining is enough
- * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
- * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
- */
- QUEUE_ORDERED_DO_PREFLUSH = 0x10,
- QUEUE_ORDERED_DO_BAR = 0x20,
- QUEUE_ORDERED_DO_POSTFLUSH = 0x40,
- QUEUE_ORDERED_DO_FUA = 0x80,
-
- QUEUE_ORDERED_NONE = 0x00,
-
- QUEUE_ORDERED_DRAIN = QUEUE_ORDERED_DO_BAR,
- QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
- QUEUE_ORDERED_DO_PREFLUSH |
- QUEUE_ORDERED_DO_POSTFLUSH,
- QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN |
- QUEUE_ORDERED_DO_PREFLUSH |
- QUEUE_ORDERED_DO_FUA,
-
- /*
- * FLUSH/FUA sequences.
- */
- QUEUE_FSEQ_STARTED = (1 << 0), /* flushing in progress */
- QUEUE_FSEQ_PREFLUSH = (1 << 1), /* pre-flushing in progress */
- QUEUE_FSEQ_DATA = (1 << 2), /* data write in progress */
- QUEUE_FSEQ_POSTFLUSH = (1 << 3), /* post-flushing in progress */
- QUEUE_FSEQ_DONE = (1 << 4),
-};
-
#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
#define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
@@ -578,7 +543,8 @@ static inline void blk_clear_queue_full(struct request_queue *q, int sync)
* it already be started by driver.
*/
#define RQ_NOMERGE_FLAGS \
- (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
+ (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER | \
+ REQ_FLUSH | REQ_FUA)
#define rq_mergeable(rq) \
(!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
(((rq)->cmd_flags & REQ_DISCARD) || \
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index ec94c12..fc999f5 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -32,7 +32,7 @@ enum bh_state_bits {
BH_Delay, /* Buffer is not yet allocated on disk */
BH_Boundary, /* Block is followed by a discontiguity */
BH_Write_EIO, /* I/O error on write */
- BH_Eopnotsupp, /* operation not supported (barrier) */
+ BH_Eopnotsupp, /* DEPRECATED: operation not supported (barrier) */
BH_Unwritten, /* Buffer is allocated on disk but not written */
BH_Quiet, /* Buffer Error Prinks to be quiet */
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 76041b6..352c486 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -135,12 +135,13 @@ struct inodes_stat_t {
* immediately after submission. The write equivalent
* of READ_SYNC.
* WRITE_ODIRECT_PLUG Special case write for O_DIRECT only.
- * WRITE_BARRIER Like WRITE_SYNC, but tells the block layer that all
- * previously submitted writes must be safely on storage
- * before this one is started. Also guarantees that when
- * this write is complete, it itself is also safely on
- * storage. Prevents reordering of writes on both sides
- * of this IO.
+ * WRITE_BARRIER DEPRECATED. Always fails. Use FLUSH/FUA instead.
+ * WRITE_FLUSH Like WRITE_SYNC but with preceding cache flush.
+ * WRITE_FUA Like WRITE_SYNC but data is guaranteed to be on
+ * non-volatile media on completion.
+ * WRITE_FLUSH_FUA Combination of WRITE_FLUSH and FUA. The IO is preceded
+ * by a cache flush and data is guaranteed to be on
+ * non-volatile media on completion.
*
*/
#define RW_MASK REQ_WRITE
@@ -158,6 +159,12 @@ struct inodes_stat_t {
#define WRITE_META (WRITE | REQ_META)
#define WRITE_BARRIER (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
REQ_HARDBARRIER)
+#define WRITE_FLUSH (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
+ REQ_FLUSH)
+#define WRITE_FUA (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
+ REQ_FUA)
+#define WRITE_FLUSH_FUA (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
+ REQ_FLUSH | REQ_FUA)
/*
* These aren't really reads or writes, they pass down information about
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 10/41] block: implement REQ_FLUSH/FUA based interface for FLUSH/FUA requests
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo, Christoph Hellwig
Now that the backend conversion is complete, export sequenced
FLUSH/FUA capability through REQ_FLUSH/FUA flags. REQ_FLUSH means the
device cache should be flushed before executing the request. REQ_FUA
means that the data in the request should be on non-volatile media on
completion.
Block layer will choose the correct way of implementing the semantics
and execute it. The request may be passed to the device directly if
the device can handle it; otherwise, it will be sequenced using one or
more proxy requests. Devices will never see REQ_FLUSH and/or FUA
which it doesn't support.
Also, unlike the original REQ_HARDBARRIER, REQ_FLUSH/FUA requests are
never failed with -EOPNOTSUPP. If the underlying device doesn't
support FLUSH/FUA, the block layer simply make those noop. IOW, it no
longer distinguishes between writeback cache which doesn't support
cache flush and writethrough/no cache. Devices which have WB cache
w/o flush are very difficult to come by these days and there's nothing
much we can do anyway, so it doesn't make sense to require everyone to
implement -EOPNOTSUPP handling. This will simplify filesystems and
block drivers as they can drop -EOPNOTSUPP retry logic for barriers.
* QUEUE_ORDERED_* are removed and QUEUE_FSEQ_* are moved into
blk-flush.c.
* REQ_FLUSH w/o data can also be directly passed to drivers without
sequencing but some drivers assume that zero length requests don't
have rq->bio which isn't true for these requests requiring the use
of proxy requests.
* REQ_COMMON_MASK now includes REQ_FLUSH | REQ_FUA so that they are
copied from bio to request.
* WRITE_BARRIER is marked deprecated and WRITE_FLUSH, WRITE_FUA and
WRITE_FLUSH_FUA are added.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
---
block/blk-core.c | 2 +-
block/blk-flush.c | 85 +++++++++++++++++++++++--------------------
block/blk.h | 3 ++
include/linux/blk_types.h | 2 +-
include/linux/blkdev.h | 38 +------------------
include/linux/buffer_head.h | 2 +-
include/linux/fs.h | 19 +++++++---
7 files changed, 67 insertions(+), 84 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 8870ae4..18455c4 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1204,7 +1204,7 @@ static int __make_request(struct request_queue *q, struct bio *bio)
spin_lock_irq(q->queue_lock);
- if (bio->bi_rw & REQ_HARDBARRIER) {
+ if (bio->bi_rw & (REQ_FLUSH | REQ_FUA)) {
where = ELEVATOR_INSERT_FRONT;
goto get_rq;
}
diff --git a/block/blk-flush.c b/block/blk-flush.c
index dd87322..452c552 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -1,5 +1,5 @@
/*
- * Functions related to barrier IO handling
+ * Functions to sequence FLUSH and FUA writes.
*/
#include <linux/kernel.h>
#include <linux/module.h>
@@ -9,6 +9,15 @@
#include "blk.h"
+/* FLUSH/FUA sequences */
+enum {
+ QUEUE_FSEQ_STARTED = (1 << 0), /* flushing in progress */
+ QUEUE_FSEQ_PREFLUSH = (1 << 1), /* pre-flushing in progress */
+ QUEUE_FSEQ_DATA = (1 << 2), /* data write in progress */
+ QUEUE_FSEQ_POSTFLUSH = (1 << 3), /* post-flushing in progress */
+ QUEUE_FSEQ_DONE = (1 << 4),
+};
+
static struct request *queue_next_fseq(struct request_queue *q);
unsigned blk_flush_cur_seq(struct request_queue *q)
@@ -79,6 +88,7 @@ static void queue_flush(struct request_queue *q, struct request *rq,
static struct request *queue_next_fseq(struct request_queue *q)
{
+ struct request *orig_rq = q->orig_flush_rq;
struct request *rq = &q->flush_rq;
switch (blk_flush_cur_seq(q)) {
@@ -87,12 +97,11 @@ static struct request *queue_next_fseq(struct request_queue *q)
break;
case QUEUE_FSEQ_DATA:
- /* initialize proxy request and queue it */
+ /* initialize proxy request, inherit FLUSH/FUA and queue it */
blk_rq_init(q, rq);
- init_request_from_bio(rq, q->orig_flush_rq->bio);
- rq->cmd_flags &= ~REQ_HARDBARRIER;
- if (q->ordered & QUEUE_ORDERED_DO_FUA)
- rq->cmd_flags |= REQ_FUA;
+ init_request_from_bio(rq, orig_rq->bio);
+ rq->cmd_flags &= ~(REQ_FLUSH | REQ_FUA);
+ rq->cmd_flags |= orig_rq->cmd_flags & (REQ_FLUSH | REQ_FUA);
rq->end_io = flush_data_end_io;
elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
@@ -110,60 +119,58 @@ static struct request *queue_next_fseq(struct request_queue *q)
struct request *blk_do_flush(struct request_queue *q, struct request *rq)
{
+ unsigned int fflags = q->flush_flags; /* may change, cache it */
+ bool has_flush = fflags & REQ_FLUSH, has_fua = fflags & REQ_FUA;
+ bool do_preflush = has_flush && (rq->cmd_flags & REQ_FLUSH);
+ bool do_postflush = has_flush && !has_fua && (rq->cmd_flags & REQ_FUA);
unsigned skip = 0;
- if (!(rq->cmd_flags & REQ_HARDBARRIER))
+ /*
+ * Special case. If there's data but flush is not necessary,
+ * the request can be issued directly.
+ *
+ * Flush w/o data should be able to be issued directly too but
+ * currently some drivers assume that rq->bio contains
+ * non-zero data if it isn't NULL and empty FLUSH requests
+ * getting here usually have bio's without data.
+ */
+ if (blk_rq_sectors(rq) && !do_preflush && !do_postflush) {
+ rq->cmd_flags &= ~REQ_FLUSH;
+ if (!has_fua)
+ rq->cmd_flags &= ~REQ_FUA;
return rq;
+ }
+ /*
+ * Sequenced flushes can't be processed in parallel. If
+ * another one is already in progress, queue for later
+ * processing.
+ */
if (q->flush_seq) {
- /*
- * Sequenced flush is already in progress and they
- * can't be processed in parallel. Queue for later
- * processing.
- */
list_move_tail(&rq->queuelist, &q->pending_flushes);
return NULL;
}
- if (unlikely(q->next_ordered == QUEUE_ORDERED_NONE)) {
- /*
- * Queue ordering not supported. Terminate
- * with prejudice.
- */
- blk_dequeue_request(rq);
- __blk_end_request_all(rq, -EOPNOTSUPP);
- return NULL;
- }
-
/*
* Start a new flush sequence
*/
q->flush_err = 0;
- q->ordered = q->next_ordered;
q->flush_seq |= QUEUE_FSEQ_STARTED;
- /*
- * For an empty barrier, there's no actual BAR request, which
- * in turn makes POSTFLUSH unnecessary. Mask them off.
- */
- if (!blk_rq_sectors(rq))
- q->ordered &= ~(QUEUE_ORDERED_DO_BAR |
- QUEUE_ORDERED_DO_POSTFLUSH);
-
- /* stash away the original request */
+ /* adjust FLUSH/FUA of the original request and stash it away */
+ rq->cmd_flags &= ~REQ_FLUSH;
+ if (!has_fua)
+ rq->cmd_flags &= ~REQ_FUA;
blk_dequeue_request(rq);
q->orig_flush_rq = rq;
- if (!(q->ordered & QUEUE_ORDERED_DO_PREFLUSH))
+ /* skip unneded sequences and return the first one */
+ if (!do_preflush)
skip |= QUEUE_FSEQ_PREFLUSH;
-
- if (!(q->ordered & QUEUE_ORDERED_DO_BAR))
+ if (!blk_rq_sectors(rq))
skip |= QUEUE_FSEQ_DATA;
-
- if (!(q->ordered & QUEUE_ORDERED_DO_POSTFLUSH))
+ if (!do_postflush)
skip |= QUEUE_FSEQ_POSTFLUSH;
-
- /* complete skipped sequences and return the first sequence */
return blk_flush_complete_seq(q, skip, 0);
}
diff --git a/block/blk.h b/block/blk.h
index 24b92bd..a09c18b 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -60,6 +60,9 @@ static inline struct request *__elv_next_request(struct request_queue *q)
while (1) {
while (!list_empty(&q->queue_head)) {
rq = list_entry_rq(q->queue_head.next);
+ if (!(rq->cmd_flags & (REQ_FLUSH | REQ_FUA)) ||
+ rq == &q->flush_rq)
+ return rq;
rq = blk_do_flush(q, rq);
if (rq)
return rq;
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 9192282..1797994 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -167,7 +167,7 @@ enum rq_flag_bits {
(REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
#define REQ_COMMON_MASK \
(REQ_WRITE | REQ_FAILFAST_MASK | REQ_HARDBARRIER | REQ_SYNC | \
- REQ_META| REQ_DISCARD | REQ_NOIDLE)
+ REQ_META | REQ_DISCARD | REQ_NOIDLE | REQ_FLUSH | REQ_FUA)
#define REQ_UNPLUG (1 << __REQ_UNPLUG)
#define REQ_RAHEAD (1 << __REQ_RAHEAD)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 1cd83ec..8ef705f 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -357,7 +357,6 @@ struct request_queue
/*
* for flush operations
*/
- unsigned int ordered, next_ordered;
unsigned int flush_flags;
unsigned int flush_seq;
int flush_err;
@@ -465,40 +464,6 @@ static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
__clear_bit(flag, &q->queue_flags);
}
-enum {
- /*
- * Hardbarrier is supported with one of the following methods.
- *
- * NONE : hardbarrier unsupported
- * DRAIN : ordering by draining is enough
- * DRAIN_FLUSH : ordering by draining w/ pre and post flushes
- * DRAIN_FUA : ordering by draining w/ pre flush and FUA write
- */
- QUEUE_ORDERED_DO_PREFLUSH = 0x10,
- QUEUE_ORDERED_DO_BAR = 0x20,
- QUEUE_ORDERED_DO_POSTFLUSH = 0x40,
- QUEUE_ORDERED_DO_FUA = 0x80,
-
- QUEUE_ORDERED_NONE = 0x00,
-
- QUEUE_ORDERED_DRAIN = QUEUE_ORDERED_DO_BAR,
- QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
- QUEUE_ORDERED_DO_PREFLUSH |
- QUEUE_ORDERED_DO_POSTFLUSH,
- QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN |
- QUEUE_ORDERED_DO_PREFLUSH |
- QUEUE_ORDERED_DO_FUA,
-
- /*
- * FLUSH/FUA sequences.
- */
- QUEUE_FSEQ_STARTED = (1 << 0), /* flushing in progress */
- QUEUE_FSEQ_PREFLUSH = (1 << 1), /* pre-flushing in progress */
- QUEUE_FSEQ_DATA = (1 << 2), /* data write in progress */
- QUEUE_FSEQ_POSTFLUSH = (1 << 3), /* post-flushing in progress */
- QUEUE_FSEQ_DONE = (1 << 4),
-};
-
#define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
#define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
@@ -578,7 +543,8 @@ static inline void blk_clear_queue_full(struct request_queue *q, int sync)
* it already be started by driver.
*/
#define RQ_NOMERGE_FLAGS \
- (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
+ (REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER | \
+ REQ_FLUSH | REQ_FUA)
#define rq_mergeable(rq) \
(!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
(((rq)->cmd_flags & REQ_DISCARD) || \
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index ec94c12..fc999f5 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -32,7 +32,7 @@ enum bh_state_bits {
BH_Delay, /* Buffer is not yet allocated on disk */
BH_Boundary, /* Block is followed by a discontiguity */
BH_Write_EIO, /* I/O error on write */
- BH_Eopnotsupp, /* operation not supported (barrier) */
+ BH_Eopnotsupp, /* DEPRECATED: operation not supported (barrier) */
BH_Unwritten, /* Buffer is allocated on disk but not written */
BH_Quiet, /* Buffer Error Prinks to be quiet */
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 76041b6..352c486 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -135,12 +135,13 @@ struct inodes_stat_t {
* immediately after submission. The write equivalent
* of READ_SYNC.
* WRITE_ODIRECT_PLUG Special case write for O_DIRECT only.
- * WRITE_BARRIER Like WRITE_SYNC, but tells the block layer that all
- * previously submitted writes must be safely on storage
- * before this one is started. Also guarantees that when
- * this write is complete, it itself is also safely on
- * storage. Prevents reordering of writes on both sides
- * of this IO.
+ * WRITE_BARRIER DEPRECATED. Always fails. Use FLUSH/FUA instead.
+ * WRITE_FLUSH Like WRITE_SYNC but with preceding cache flush.
+ * WRITE_FUA Like WRITE_SYNC but data is guaranteed to be on
+ * non-volatile media on completion.
+ * WRITE_FLUSH_FUA Combination of WRITE_FLUSH and FUA. The IO is preceded
+ * by a cache flush and data is guaranteed to be on
+ * non-volatile media on completion.
*
*/
#define RW_MASK REQ_WRITE
@@ -158,6 +159,12 @@ struct inodes_stat_t {
#define WRITE_META (WRITE | REQ_META)
#define WRITE_BARRIER (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
REQ_HARDBARRIER)
+#define WRITE_FLUSH (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
+ REQ_FLUSH)
+#define WRITE_FUA (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
+ REQ_FUA)
+#define WRITE_FLUSH_FUA (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
+ REQ_FLUSH | REQ_FUA)
/*
* These aren't really reads or writes, they pass down information about
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 11/41] block: filter flush bio's in __generic_make_request()
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
There are a number of make_request based drivers which don't support
cache flushes. Filter out flush bio's in __generic_make_request() so
that they don't have to worry about them. All FLUSH/FUA requests with
data are converted to regular IO requests and empty ones are completed
immediately.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
block/blk-core.c | 13 +++++++++++++
1 files changed, 13 insertions(+), 0 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 18455c4..495bdc4 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1509,6 +1509,19 @@ static inline void __generic_make_request(struct bio *bio)
if (bio_check_eod(bio, nr_sectors))
goto end_io;
+ /*
+ * Filter flush bio's early so that make_request based
+ * drivers without flush support don't have to worry
+ * about them.
+ */
+ if ((bio->bi_rw & (REQ_FLUSH | REQ_FUA)) && !q->flush_flags) {
+ bio->bi_rw &= ~(REQ_FLUSH | REQ_FUA);
+ if (!nr_sectors) {
+ err = 0;
+ goto end_io;
+ }
+ }
+
if ((bio->bi_rw & REQ_DISCARD) &&
(!blk_queue_discard(q) ||
((bio->bi_rw & REQ_SECURE) &&
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 11/41] block: filter flush bio's in __generic_make_request()
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
There are a number of make_request based drivers which don't support
cache flushes. Filter out flush bio's in __generic_make_request() so
that they don't have to worry about them. All FLUSH/FUA requests with
data are converted to regular IO requests and empty ones are completed
immediately.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
block/blk-core.c | 13 +++++++++++++
1 files changed, 13 insertions(+), 0 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 18455c4..495bdc4 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1509,6 +1509,19 @@ static inline void __generic_make_request(struct bio *bio)
if (bio_check_eod(bio, nr_sectors))
goto end_io;
+ /*
+ * Filter flush bio's early so that make_request based
+ * drivers without flush support don't have to worry
+ * about them.
+ */
+ if ((bio->bi_rw & (REQ_FLUSH | REQ_FUA)) && !q->flush_flags) {
+ bio->bi_rw &= ~(REQ_FLUSH | REQ_FUA);
+ if (!nr_sectors) {
+ err = 0;
+ goto end_io;
+ }
+ }
+
if ((bio->bi_rw & REQ_DISCARD) &&
(!blk_queue_discard(q) ||
((bio->bi_rw & REQ_SECURE) &&
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 11/41] block: filter flush bio's in __generic_make_request()
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo
There are a number of make_request based drivers which don't support
cache flushes. Filter out flush bio's in __generic_make_request() so
that they don't have to worry about them. All FLUSH/FUA requests with
data are converted to regular IO requests and empty ones are completed
immediately.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
block/blk-core.c | 13 +++++++++++++
1 files changed, 13 insertions(+), 0 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 18455c4..495bdc4 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1509,6 +1509,19 @@ static inline void __generic_make_request(struct bio *bio)
if (bio_check_eod(bio, nr_sectors))
goto end_io;
+ /*
+ * Filter flush bio's early so that make_request based
+ * drivers without flush support don't have to worry
+ * about them.
+ */
+ if ((bio->bi_rw & (REQ_FLUSH | REQ_FUA)) && !q->flush_flags) {
+ bio->bi_rw &= ~(REQ_FLUSH | REQ_FUA);
+ if (!nr_sectors) {
+ err = 0;
+ goto end_io;
+ }
+ }
+
if ((bio->bi_rw & REQ_DISCARD) &&
(!blk_queue_discard(q) ||
((bio->bi_rw & REQ_SECURE) &&
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 12/41] block: simplify queue_next_fseq
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
From: Christoph Hellwig <hch@lst.de>
We need to call blk_rq_init and elv_insert for all cases in queue_next_fseq,
so take these calls into common code. Also move the end_io initialization
from queue_flush into queue_next_fseq and rename queue_flush to
init_flush_request now that it's old name doesn't apply anymore.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
block/blk-flush.c | 26 ++++++++++----------------
1 files changed, 10 insertions(+), 16 deletions(-)
diff --git a/block/blk-flush.c b/block/blk-flush.c
index 452c552..72905f8 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -74,16 +74,11 @@ static void post_flush_end_io(struct request *rq, int error)
blk_flush_complete_seq(rq->q, QUEUE_FSEQ_POSTFLUSH, error);
}
-static void queue_flush(struct request_queue *q, struct request *rq,
- rq_end_io_fn *end_io)
+static void init_flush_request(struct request *rq, struct gendisk *disk)
{
- blk_rq_init(q, rq);
rq->cmd_type = REQ_TYPE_FS;
rq->cmd_flags = REQ_FLUSH;
- rq->rq_disk = q->orig_flush_rq->rq_disk;
- rq->end_io = end_io;
-
- elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
+ rq->rq_disk = disk;
}
static struct request *queue_next_fseq(struct request_queue *q)
@@ -91,29 +86,28 @@ static struct request *queue_next_fseq(struct request_queue *q)
struct request *orig_rq = q->orig_flush_rq;
struct request *rq = &q->flush_rq;
+ blk_rq_init(q, rq);
+
switch (blk_flush_cur_seq(q)) {
case QUEUE_FSEQ_PREFLUSH:
- queue_flush(q, rq, pre_flush_end_io);
+ init_flush_request(rq, orig_rq->rq_disk);
+ rq->end_io = pre_flush_end_io;
break;
-
case QUEUE_FSEQ_DATA:
- /* initialize proxy request, inherit FLUSH/FUA and queue it */
- blk_rq_init(q, rq);
init_request_from_bio(rq, orig_rq->bio);
rq->cmd_flags &= ~(REQ_FLUSH | REQ_FUA);
rq->cmd_flags |= orig_rq->cmd_flags & (REQ_FLUSH | REQ_FUA);
rq->end_io = flush_data_end_io;
-
- elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
break;
-
case QUEUE_FSEQ_POSTFLUSH:
- queue_flush(q, rq, post_flush_end_io);
+ init_flush_request(rq, orig_rq->rq_disk);
+ rq->end_io = post_flush_end_io;
break;
-
default:
BUG();
}
+
+ elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
return rq;
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 12/41] block: simplify queue_next_fseq
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
From: Christoph Hellwig <hch@lst.de>
We need to call blk_rq_init and elv_insert for all cases in queue_next_fseq,
so take these calls into common code. Also move the end_io initialization
from queue_flush into queue_next_fseq and rename queue_flush to
init_flush_request now that it's old name doesn't apply anymore.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
block/blk-flush.c | 26 ++++++++++----------------
1 files changed, 10 insertions(+), 16 deletions(-)
diff --git a/block/blk-flush.c b/block/blk-flush.c
index 452c552..72905f8 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -74,16 +74,11 @@ static void post_flush_end_io(struct request *rq, int error)
blk_flush_complete_seq(rq->q, QUEUE_FSEQ_POSTFLUSH, error);
}
-static void queue_flush(struct request_queue *q, struct request *rq,
- rq_end_io_fn *end_io)
+static void init_flush_request(struct request *rq, struct gendisk *disk)
{
- blk_rq_init(q, rq);
rq->cmd_type = REQ_TYPE_FS;
rq->cmd_flags = REQ_FLUSH;
- rq->rq_disk = q->orig_flush_rq->rq_disk;
- rq->end_io = end_io;
-
- elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
+ rq->rq_disk = disk;
}
static struct request *queue_next_fseq(struct request_queue *q)
@@ -91,29 +86,28 @@ static struct request *queue_next_fseq(struct request_queue *q)
struct request *orig_rq = q->orig_flush_rq;
struct request *rq = &q->flush_rq;
+ blk_rq_init(q, rq);
+
switch (blk_flush_cur_seq(q)) {
case QUEUE_FSEQ_PREFLUSH:
- queue_flush(q, rq, pre_flush_end_io);
+ init_flush_request(rq, orig_rq->rq_disk);
+ rq->end_io = pre_flush_end_io;
break;
-
case QUEUE_FSEQ_DATA:
- /* initialize proxy request, inherit FLUSH/FUA and queue it */
- blk_rq_init(q, rq);
init_request_from_bio(rq, orig_rq->bio);
rq->cmd_flags &= ~(REQ_FLUSH | REQ_FUA);
rq->cmd_flags |= orig_rq->cmd_flags & (REQ_FLUSH | REQ_FUA);
rq->end_io = flush_data_end_io;
-
- elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
break;
-
case QUEUE_FSEQ_POSTFLUSH:
- queue_flush(q, rq, post_flush_end_io);
+ init_flush_request(rq, orig_rq->rq_disk);
+ rq->end_io = post_flush_end_io;
break;
-
default:
BUG();
}
+
+ elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
return rq;
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 12/41] block: simplify queue_next_fseq
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo
From: Christoph Hellwig <hch@lst.de>
We need to call blk_rq_init and elv_insert for all cases in queue_next_fseq,
so take these calls into common code. Also move the end_io initialization
from queue_flush into queue_next_fseq and rename queue_flush to
init_flush_request now that it's old name doesn't apply anymore.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
block/blk-flush.c | 26 ++++++++++----------------
1 files changed, 10 insertions(+), 16 deletions(-)
diff --git a/block/blk-flush.c b/block/blk-flush.c
index 452c552..72905f8 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -74,16 +74,11 @@ static void post_flush_end_io(struct request *rq, int error)
blk_flush_complete_seq(rq->q, QUEUE_FSEQ_POSTFLUSH, error);
}
-static void queue_flush(struct request_queue *q, struct request *rq,
- rq_end_io_fn *end_io)
+static void init_flush_request(struct request *rq, struct gendisk *disk)
{
- blk_rq_init(q, rq);
rq->cmd_type = REQ_TYPE_FS;
rq->cmd_flags = REQ_FLUSH;
- rq->rq_disk = q->orig_flush_rq->rq_disk;
- rq->end_io = end_io;
-
- elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
+ rq->rq_disk = disk;
}
static struct request *queue_next_fseq(struct request_queue *q)
@@ -91,29 +86,28 @@ static struct request *queue_next_fseq(struct request_queue *q)
struct request *orig_rq = q->orig_flush_rq;
struct request *rq = &q->flush_rq;
+ blk_rq_init(q, rq);
+
switch (blk_flush_cur_seq(q)) {
case QUEUE_FSEQ_PREFLUSH:
- queue_flush(q, rq, pre_flush_end_io);
+ init_flush_request(rq, orig_rq->rq_disk);
+ rq->end_io = pre_flush_end_io;
break;
-
case QUEUE_FSEQ_DATA:
- /* initialize proxy request, inherit FLUSH/FUA and queue it */
- blk_rq_init(q, rq);
init_request_from_bio(rq, orig_rq->bio);
rq->cmd_flags &= ~(REQ_FLUSH | REQ_FUA);
rq->cmd_flags |= orig_rq->cmd_flags & (REQ_FLUSH | REQ_FUA);
rq->end_io = flush_data_end_io;
-
- elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
break;
-
case QUEUE_FSEQ_POSTFLUSH:
- queue_flush(q, rq, post_flush_end_io);
+ init_flush_request(rq, orig_rq->rq_disk);
+ rq->end_io = post_flush_end_io;
break;
-
default:
BUG();
}
+
+ elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
return rq;
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 13/41] block: initialize flush request with WRITE_FLUSH instead of REQ_FLUSH
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
init_flush_request() only set REQ_FLUSH when initializing flush
requests making them READ requests. Use WRITE_FLUSH instead.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Mike Snitzer <snitzer@redhat.com>
---
block/blk-flush.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/block/blk-flush.c b/block/blk-flush.c
index 72905f8..f357f1f 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -77,7 +77,7 @@ static void post_flush_end_io(struct request *rq, int error)
static void init_flush_request(struct request *rq, struct gendisk *disk)
{
rq->cmd_type = REQ_TYPE_FS;
- rq->cmd_flags = REQ_FLUSH;
+ rq->cmd_flags = WRITE_FLUSH;
rq->rq_disk = disk;
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 13/41] block: initialize flush request with WRITE_FLUSH instead of REQ_FLUSH
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
init_flush_request() only set REQ_FLUSH when initializing flush
requests making them READ requests. Use WRITE_FLUSH instead.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Mike Snitzer <snitzer@redhat.com>
---
block/blk-flush.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/block/blk-flush.c b/block/blk-flush.c
index 72905f8..f357f1f 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -77,7 +77,7 @@ static void post_flush_end_io(struct request *rq, int error)
static void init_flush_request(struct request *rq, struct gendisk *disk)
{
rq->cmd_type = REQ_TYPE_FS;
- rq->cmd_flags = REQ_FLUSH;
+ rq->cmd_flags = WRITE_FLUSH;
rq->rq_disk = disk;
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 13/41] block: initialize flush request with WRITE_FLUSH instead of REQ_FLUSH
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo
init_flush_request() only set REQ_FLUSH when initializing flush
requests making them READ requests. Use WRITE_FLUSH instead.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Mike Snitzer <snitzer@redhat.com>
---
block/blk-flush.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/block/blk-flush.c b/block/blk-flush.c
index 72905f8..f357f1f 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -77,7 +77,7 @@ static void post_flush_end_io(struct request *rq, int error)
static void init_flush_request(struct request *rq, struct gendisk *disk)
{
rq->cmd_type = REQ_TYPE_FS;
- rq->cmd_flags = REQ_FLUSH;
+ rq->cmd_flags = WRITE_FLUSH;
rq->rq_disk = disk;
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 14/41] block: kick queue after sequencing REQ_FLUSH/FUA
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
While completing a request from a REQ_FLUSH/FUA sequence, another
request can be pushed to the request queue. If a driver tests
elv_queue_empty() before completing a request and runs the queue again
only if the queue wasn't empty, this may lead to hang. Please note
that most drivers either kick the queue unconditionally or test queue
emptiness after completing the current request and don't have this
problem.
This patch removes this possibility by making REQ_FLUSH/FUA sequence
code kick the queue if the queue was empty before completing a request
from REQ_FLUSH/FUA sequence.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
block/blk-flush.c | 22 +++++++++++++++++++---
1 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/block/blk-flush.c b/block/blk-flush.c
index f357f1f..cb4c844 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -56,22 +56,38 @@ static struct request *blk_flush_complete_seq(struct request_queue *q,
return next_rq;
}
+static void blk_flush_complete_seq_end_io(struct request_queue *q,
+ unsigned seq, int error)
+{
+ bool was_empty = elv_queue_empty(q);
+ struct request *next_rq;
+
+ next_rq = blk_flush_complete_seq(q, seq, error);
+
+ /*
+ * Moving a request silently to empty queue_head may stall the
+ * queue. Kick the queue in those cases.
+ */
+ if (was_empty && next_rq)
+ __blk_run_queue(q);
+}
+
static void pre_flush_end_io(struct request *rq, int error)
{
elv_completed_request(rq->q, rq);
- blk_flush_complete_seq(rq->q, QUEUE_FSEQ_PREFLUSH, error);
+ blk_flush_complete_seq_end_io(rq->q, QUEUE_FSEQ_PREFLUSH, error);
}
static void flush_data_end_io(struct request *rq, int error)
{
elv_completed_request(rq->q, rq);
- blk_flush_complete_seq(rq->q, QUEUE_FSEQ_DATA, error);
+ blk_flush_complete_seq_end_io(rq->q, QUEUE_FSEQ_DATA, error);
}
static void post_flush_end_io(struct request *rq, int error)
{
elv_completed_request(rq->q, rq);
- blk_flush_complete_seq(rq->q, QUEUE_FSEQ_POSTFLUSH, error);
+ blk_flush_complete_seq_end_io(rq->q, QUEUE_FSEQ_POSTFLUSH, error);
}
static void init_flush_request(struct request *rq, struct gendisk *disk)
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 14/41] block: kick queue after sequencing REQ_FLUSH/FUA
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
While completing a request from a REQ_FLUSH/FUA sequence, another
request can be pushed to the request queue. If a driver tests
elv_queue_empty() before completing a request and runs the queue again
only if the queue wasn't empty, this may lead to hang. Please note
that most drivers either kick the queue unconditionally or test queue
emptiness after completing the current request and don't have this
problem.
This patch removes this possibility by making REQ_FLUSH/FUA sequence
code kick the queue if the queue was empty before completing a request
from REQ_FLUSH/FUA sequence.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
block/blk-flush.c | 22 +++++++++++++++++++---
1 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/block/blk-flush.c b/block/blk-flush.c
index f357f1f..cb4c844 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -56,22 +56,38 @@ static struct request *blk_flush_complete_seq(struct request_queue *q,
return next_rq;
}
+static void blk_flush_complete_seq_end_io(struct request_queue *q,
+ unsigned seq, int error)
+{
+ bool was_empty = elv_queue_empty(q);
+ struct request *next_rq;
+
+ next_rq = blk_flush_complete_seq(q, seq, error);
+
+ /*
+ * Moving a request silently to empty queue_head may stall the
+ * queue. Kick the queue in those cases.
+ */
+ if (was_empty && next_rq)
+ __blk_run_queue(q);
+}
+
static void pre_flush_end_io(struct request *rq, int error)
{
elv_completed_request(rq->q, rq);
- blk_flush_complete_seq(rq->q, QUEUE_FSEQ_PREFLUSH, error);
+ blk_flush_complete_seq_end_io(rq->q, QUEUE_FSEQ_PREFLUSH, error);
}
static void flush_data_end_io(struct request *rq, int error)
{
elv_completed_request(rq->q, rq);
- blk_flush_complete_seq(rq->q, QUEUE_FSEQ_DATA, error);
+ blk_flush_complete_seq_end_io(rq->q, QUEUE_FSEQ_DATA, error);
}
static void post_flush_end_io(struct request *rq, int error)
{
elv_completed_request(rq->q, rq);
- blk_flush_complete_seq(rq->q, QUEUE_FSEQ_POSTFLUSH, error);
+ blk_flush_complete_seq_end_io(rq->q, QUEUE_FSEQ_POSTFLUSH, error);
}
static void init_flush_request(struct request *rq, struct gendisk *disk)
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 14/41] block: kick queue after sequencing REQ_FLUSH/FUA
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo
While completing a request from a REQ_FLUSH/FUA sequence, another
request can be pushed to the request queue. If a driver tests
elv_queue_empty() before completing a request and runs the queue again
only if the queue wasn't empty, this may lead to hang. Please note
that most drivers either kick the queue unconditionally or test queue
emptiness after completing the current request and don't have this
problem.
This patch removes this possibility by making REQ_FLUSH/FUA sequence
code kick the queue if the queue was empty before completing a request
from REQ_FLUSH/FUA sequence.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
block/blk-flush.c | 22 +++++++++++++++++++---
1 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/block/blk-flush.c b/block/blk-flush.c
index f357f1f..cb4c844 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -56,22 +56,38 @@ static struct request *blk_flush_complete_seq(struct request_queue *q,
return next_rq;
}
+static void blk_flush_complete_seq_end_io(struct request_queue *q,
+ unsigned seq, int error)
+{
+ bool was_empty = elv_queue_empty(q);
+ struct request *next_rq;
+
+ next_rq = blk_flush_complete_seq(q, seq, error);
+
+ /*
+ * Moving a request silently to empty queue_head may stall the
+ * queue. Kick the queue in those cases.
+ */
+ if (was_empty && next_rq)
+ __blk_run_queue(q);
+}
+
static void pre_flush_end_io(struct request *rq, int error)
{
elv_completed_request(rq->q, rq);
- blk_flush_complete_seq(rq->q, QUEUE_FSEQ_PREFLUSH, error);
+ blk_flush_complete_seq_end_io(rq->q, QUEUE_FSEQ_PREFLUSH, error);
}
static void flush_data_end_io(struct request *rq, int error)
{
elv_completed_request(rq->q, rq);
- blk_flush_complete_seq(rq->q, QUEUE_FSEQ_DATA, error);
+ blk_flush_complete_seq_end_io(rq->q, QUEUE_FSEQ_DATA, error);
}
static void post_flush_end_io(struct request *rq, int error)
{
elv_completed_request(rq->q, rq);
- blk_flush_complete_seq(rq->q, QUEUE_FSEQ_POSTFLUSH, error);
+ blk_flush_complete_seq_end_io(rq->q, QUEUE_FSEQ_POSTFLUSH, error);
}
static void init_flush_request(struct request *rq, struct gendisk *disk)
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 15/41] block: make sure FSEQ_DATA request has the same rq_disk as the original
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
rq->rq_disk and bio->bi_bdev->bd_disk may differ if a request has
passed through remapping drivers. FSEQ_DATA request incorrectly
followed bio->bi_bdev->bd_disk ending up being issued w/ mismatching
rq_disk. Make it follow orig_rq->rq_disk.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Tested-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
---
block/blk-flush.c | 7 +++++++
1 files changed, 7 insertions(+), 0 deletions(-)
diff --git a/block/blk-flush.c b/block/blk-flush.c
index cb4c844..7d1fc98 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -111,6 +111,13 @@ static struct request *queue_next_fseq(struct request_queue *q)
break;
case QUEUE_FSEQ_DATA:
init_request_from_bio(rq, orig_rq->bio);
+ /*
+ * orig_rq->rq_disk may be different from
+ * bio->bi_bdev->bd_disk if orig_rq got here through
+ * remapping drivers. Make sure rq->rq_disk points
+ * to the same one as orig_rq.
+ */
+ rq->rq_disk = orig_rq->rq_disk;
rq->cmd_flags &= ~(REQ_FLUSH | REQ_FUA);
rq->cmd_flags |= orig_rq->cmd_flags & (REQ_FLUSH | REQ_FUA);
rq->end_io = flush_data_end_io;
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 15/41] block: make sure FSEQ_DATA request has the same rq_disk as the original
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
rq->rq_disk and bio->bi_bdev->bd_disk may differ if a request has
passed through remapping drivers. FSEQ_DATA request incorrectly
followed bio->bi_bdev->bd_disk ending up being issued w/ mismatching
rq_disk. Make it follow orig_rq->rq_disk.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Tested-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
---
block/blk-flush.c | 7 +++++++
1 files changed, 7 insertions(+), 0 deletions(-)
diff --git a/block/blk-flush.c b/block/blk-flush.c
index cb4c844..7d1fc98 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -111,6 +111,13 @@ static struct request *queue_next_fseq(struct request_queue *q)
break;
case QUEUE_FSEQ_DATA:
init_request_from_bio(rq, orig_rq->bio);
+ /*
+ * orig_rq->rq_disk may be different from
+ * bio->bi_bdev->bd_disk if orig_rq got here through
+ * remapping drivers. Make sure rq->rq_disk points
+ * to the same one as orig_rq.
+ */
+ rq->rq_disk = orig_rq->rq_disk;
rq->cmd_flags &= ~(REQ_FLUSH | REQ_FUA);
rq->cmd_flags |= orig_rq->cmd_flags & (REQ_FLUSH | REQ_FUA);
rq->end_io = flush_data_end_io;
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 15/41] block: make sure FSEQ_DATA request has the same rq_disk as the original
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo
rq->rq_disk and bio->bi_bdev->bd_disk may differ if a request has
passed through remapping drivers. FSEQ_DATA request incorrectly
followed bio->bi_bdev->bd_disk ending up being issued w/ mismatching
rq_disk. Make it follow orig_rq->rq_disk.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Tested-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
---
block/blk-flush.c | 7 +++++++
1 files changed, 7 insertions(+), 0 deletions(-)
diff --git a/block/blk-flush.c b/block/blk-flush.c
index cb4c844..7d1fc98 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -111,6 +111,13 @@ static struct request *queue_next_fseq(struct request_queue *q)
break;
case QUEUE_FSEQ_DATA:
init_request_from_bio(rq, orig_rq->bio);
+ /*
+ * orig_rq->rq_disk may be different from
+ * bio->bi_bdev->bd_disk if orig_rq got here through
+ * remapping drivers. Make sure rq->rq_disk points
+ * to the same one as orig_rq.
+ */
+ rq->rq_disk = orig_rq->rq_disk;
rq->cmd_flags &= ~(REQ_FLUSH | REQ_FUA);
rq->cmd_flags |= orig_rq->cmd_flags & (REQ_FLUSH | REQ_FUA);
rq->end_io = flush_data_end_io;
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 16/41] block: update documentation for REQ_FLUSH / REQ_FUA
2010-09-03 10:29 ` Tejun Heo
` (22 preceding siblings ...)
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
From: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
Documentation/block/00-INDEX | 4 +-
Documentation/block/barrier.txt | 261 -----------------------
Documentation/block/writeback_cache_control.txt | 86 ++++++++
3 files changed, 88 insertions(+), 263 deletions(-)
delete mode 100644 Documentation/block/barrier.txt
create mode 100644 Documentation/block/writeback_cache_control.txt
diff --git a/Documentation/block/00-INDEX b/Documentation/block/00-INDEX
index a406286..d111e3b 100644
--- a/Documentation/block/00-INDEX
+++ b/Documentation/block/00-INDEX
@@ -1,7 +1,5 @@
00-INDEX
- This file
-barrier.txt
- - I/O Barriers
biodoc.txt
- Notes on the Generic Block Layer Rewrite in Linux 2.5
capability.txt
@@ -16,3 +14,5 @@ stat.txt
- Block layer statistics in /sys/block/<dev>/stat
switching-sched.txt
- Switching I/O schedulers at runtime
+writeback_cache_control.txt
+ - Control of volatile write back caches
diff --git a/Documentation/block/barrier.txt b/Documentation/block/barrier.txt
deleted file mode 100644
index 2c2f24f..0000000
--- a/Documentation/block/barrier.txt
+++ /dev/null
@@ -1,261 +0,0 @@
-I/O Barriers
-============
-Tejun Heo <htejun@gmail.com>, July 22 2005
-
-I/O barrier requests are used to guarantee ordering around the barrier
-requests. Unless you're crazy enough to use disk drives for
-implementing synchronization constructs (wow, sounds interesting...),
-the ordering is meaningful only for write requests for things like
-journal checkpoints. All requests queued before a barrier request
-must be finished (made it to the physical medium) before the barrier
-request is started, and all requests queued after the barrier request
-must be started only after the barrier request is finished (again,
-made it to the physical medium).
-
-In other words, I/O barrier requests have the following two properties.
-
-1. Request ordering
-
-Requests cannot pass the barrier request. Preceding requests are
-processed before the barrier and following requests after.
-
-Depending on what features a drive supports, this can be done in one
-of the following three ways.
-
-i. For devices which have queue depth greater than 1 (TCQ devices) and
-support ordered tags, block layer can just issue the barrier as an
-ordered request and the lower level driver, controller and drive
-itself are responsible for making sure that the ordering constraint is
-met. Most modern SCSI controllers/drives should support this.
-
-NOTE: SCSI ordered tag isn't currently used due to limitation in the
- SCSI midlayer, see the following random notes section.
-
-ii. For devices which have queue depth greater than 1 but don't
-support ordered tags, block layer ensures that the requests preceding
-a barrier request finishes before issuing the barrier request. Also,
-it defers requests following the barrier until the barrier request is
-finished. Older SCSI controllers/drives and SATA drives fall in this
-category.
-
-iii. Devices which have queue depth of 1. This is a degenerate case
-of ii. Just keeping issue order suffices. Ancient SCSI
-controllers/drives and IDE drives are in this category.
-
-2. Forced flushing to physical medium
-
-Again, if you're not gonna do synchronization with disk drives (dang,
-it sounds even more appealing now!), the reason you use I/O barriers
-is mainly to protect filesystem integrity when power failure or some
-other events abruptly stop the drive from operating and possibly make
-the drive lose data in its cache. So, I/O barriers need to guarantee
-that requests actually get written to non-volatile medium in order.
-
-There are four cases,
-
-i. No write-back cache. Keeping requests ordered is enough.
-
-ii. Write-back cache but no flush operation. There's no way to
-guarantee physical-medium commit order. This kind of devices can't to
-I/O barriers.
-
-iii. Write-back cache and flush operation but no FUA (forced unit
-access). We need two cache flushes - before and after the barrier
-request.
-
-iv. Write-back cache, flush operation and FUA. We still need one
-flush to make sure requests preceding a barrier are written to medium,
-but post-barrier flush can be avoided by using FUA write on the
-barrier itself.
-
-
-How to support barrier requests in drivers
-------------------------------------------
-
-All barrier handling is done inside block layer proper. All low level
-drivers have to are implementing its prepare_flush_fn and using one
-the following two functions to indicate what barrier type it supports
-and how to prepare flush requests. Note that the term 'ordered' is
-used to indicate the whole sequence of performing barrier requests
-including draining and flushing.
-
-typedef void (prepare_flush_fn)(struct request_queue *q, struct request *rq);
-
-int blk_queue_ordered(struct request_queue *q, unsigned ordered,
- prepare_flush_fn *prepare_flush_fn);
-
-@q : the queue in question
-@ordered : the ordered mode the driver/device supports
-@prepare_flush_fn : this function should prepare @rq such that it
- flushes cache to physical medium when executed
-
-For example, SCSI disk driver's prepare_flush_fn looks like the
-following.
-
-static void sd_prepare_flush(struct request_queue *q, struct request *rq)
-{
- memset(rq->cmd, 0, sizeof(rq->cmd));
- rq->cmd_type = REQ_TYPE_BLOCK_PC;
- rq->timeout = SD_TIMEOUT;
- rq->cmd[0] = SYNCHRONIZE_CACHE;
- rq->cmd_len = 10;
-}
-
-The following seven ordered modes are supported. The following table
-shows which mode should be used depending on what features a
-device/driver supports. In the leftmost column of table,
-QUEUE_ORDERED_ prefix is omitted from the mode names to save space.
-
-The table is followed by description of each mode. Note that in the
-descriptions of QUEUE_ORDERED_DRAIN*, '=>' is used whereas '->' is
-used for QUEUE_ORDERED_TAG* descriptions. '=>' indicates that the
-preceding step must be complete before proceeding to the next step.
-'->' indicates that the next step can start as soon as the previous
-step is issued.
-
- write-back cache ordered tag flush FUA
------------------------------------------------------------------------
-NONE yes/no N/A no N/A
-DRAIN no no N/A N/A
-DRAIN_FLUSH yes no yes no
-DRAIN_FUA yes no yes yes
-TAG no yes N/A N/A
-TAG_FLUSH yes yes yes no
-TAG_FUA yes yes yes yes
-
-
-QUEUE_ORDERED_NONE
- I/O barriers are not needed and/or supported.
-
- Sequence: N/A
-
-QUEUE_ORDERED_DRAIN
- Requests are ordered by draining the request queue and cache
- flushing isn't needed.
-
- Sequence: drain => barrier
-
-QUEUE_ORDERED_DRAIN_FLUSH
- Requests are ordered by draining the request queue and both
- pre-barrier and post-barrier cache flushings are needed.
-
- Sequence: drain => preflush => barrier => postflush
-
-QUEUE_ORDERED_DRAIN_FUA
- Requests are ordered by draining the request queue and
- pre-barrier cache flushing is needed. By using FUA on barrier
- request, post-barrier flushing can be skipped.
-
- Sequence: drain => preflush => barrier
-
-QUEUE_ORDERED_TAG
- Requests are ordered by ordered tag and cache flushing isn't
- needed.
-
- Sequence: barrier
-
-QUEUE_ORDERED_TAG_FLUSH
- Requests are ordered by ordered tag and both pre-barrier and
- post-barrier cache flushings are needed.
-
- Sequence: preflush -> barrier -> postflush
-
-QUEUE_ORDERED_TAG_FUA
- Requests are ordered by ordered tag and pre-barrier cache
- flushing is needed. By using FUA on barrier request,
- post-barrier flushing can be skipped.
-
- Sequence: preflush -> barrier
-
-
-Random notes/caveats
---------------------
-
-* SCSI layer currently can't use TAG ordering even if the drive,
-controller and driver support it. The problem is that SCSI midlayer
-request dispatch function is not atomic. It releases queue lock and
-switch to SCSI host lock during issue and it's possible and likely to
-happen in time that requests change their relative positions. Once
-this problem is solved, TAG ordering can be enabled.
-
-* Currently, no matter which ordered mode is used, there can be only
-one barrier request in progress. All I/O barriers are held off by
-block layer until the previous I/O barrier is complete. This doesn't
-make any difference for DRAIN ordered devices, but, for TAG ordered
-devices with very high command latency, passing multiple I/O barriers
-to low level *might* be helpful if they are very frequent. Well, this
-certainly is a non-issue. I'm writing this just to make clear that no
-two I/O barrier is ever passed to low-level driver.
-
-* Completion order. Requests in ordered sequence are issued in order
-but not required to finish in order. Barrier implementation can
-handle out-of-order completion of ordered sequence. IOW, the requests
-MUST be processed in order but the hardware/software completion paths
-are allowed to reorder completion notifications - eg. current SCSI
-midlayer doesn't preserve completion order during error handling.
-
-* Requeueing order. Low-level drivers are free to requeue any request
-after they removed it from the request queue with
-blkdev_dequeue_request(). As barrier sequence should be kept in order
-when requeued, generic elevator code takes care of putting requests in
-order around barrier. See blk_ordered_req_seq() and
-ELEVATOR_INSERT_REQUEUE handling in __elv_add_request() for details.
-
-Note that block drivers must not requeue preceding requests while
-completing latter requests in an ordered sequence. Currently, no
-error checking is done against this.
-
-* Error handling. Currently, block layer will report error to upper
-layer if any of requests in an ordered sequence fails. Unfortunately,
-this doesn't seem to be enough. Look at the following request flow.
-QUEUE_ORDERED_TAG_FLUSH is in use.
-
- [0] [1] [2] [3] [pre] [barrier] [post] < [4] [5] [6] ... >
- still in elevator
-
-Let's say request [2], [3] are write requests to update file system
-metadata (journal or whatever) and [barrier] is used to mark that
-those updates are valid. Consider the following sequence.
-
- i. Requests [0] ~ [post] leaves the request queue and enters
- low-level driver.
- ii. After a while, unfortunately, something goes wrong and the
- drive fails [2]. Note that any of [0], [1] and [3] could have
- completed by this time, but [pre] couldn't have been finished
- as the drive must process it in order and it failed before
- processing that command.
- iii. Error handling kicks in and determines that the error is
- unrecoverable and fails [2], and resumes operation.
- iv. [pre] [barrier] [post] gets processed.
- v. *BOOM* power fails
-
-The problem here is that the barrier request is *supposed* to indicate
-that filesystem update requests [2] and [3] made it safely to the
-physical medium and, if the machine crashes after the barrier is
-written, filesystem recovery code can depend on that. Sadly, that
-isn't true in this case anymore. IOW, the success of a I/O barrier
-should also be dependent on success of some of the preceding requests,
-where only upper layer (filesystem) knows what 'some' is.
-
-This can be solved by implementing a way to tell the block layer which
-requests affect the success of the following barrier request and
-making lower lever drivers to resume operation on error only after
-block layer tells it to do so.
-
-As the probability of this happening is very low and the drive should
-be faulty, implementing the fix is probably an overkill. But, still,
-it's there.
-
-* In previous drafts of barrier implementation, there was fallback
-mechanism such that, if FUA or ordered TAG fails, less fancy ordered
-mode can be selected and the failed barrier request is retried
-automatically. The rationale for this feature was that as FUA is
-pretty new in ATA world and ordered tag was never used widely, there
-could be devices which report to support those features but choke when
-actually given such requests.
-
- This was removed for two reasons 1. it's an overkill 2. it's
-impossible to implement properly when TAG ordering is used as low
-level drivers resume after an error automatically. If it's ever
-needed adding it back and modifying low level drivers accordingly
-shouldn't be difficult.
diff --git a/Documentation/block/writeback_cache_control.txt b/Documentation/block/writeback_cache_control.txt
new file mode 100644
index 0000000..83407d3
--- /dev/null
+++ b/Documentation/block/writeback_cache_control.txt
@@ -0,0 +1,86 @@
+
+Explicit volatile write back cache control
+=====================================
+
+Introduction
+------------
+
+Many storage devices, especially in the consumer market, come with volatile
+write back caches. That means the devices signal I/O completion to the
+operating system before data actually has hit the non-volatile storage. This
+behavior obviously speeds up various workloads, but it means the operating
+system needs to force data out to the non-volatile storage when it performs
+a data integrity operation like fsync, sync or an unmount.
+
+The Linux block layer provides two simple mechanisms that let filesystems
+control the caching behavior of the storage device. These mechanisms are
+a forced cache flush, and the Force Unit Access (FUA) flag for requests.
+
+
+Explicit cache flushes
+----------------------
+
+The REQ_FLUSH flag can be OR ed into the r/w flags of a bio submitted from
+the filesystem and will make sure the volatile cache of the storage device
+has been flushed before the actual I/O operation is started. This explicitly
+guarantees that previously completed write requests are on non-volatile
+storage before the flagged bio starts. In addition the REQ_FLUSH flag can be
+set on an otherwise empty bio structure, which causes only an explicit cache
+flush without any dependent I/O. It is recommend to use
+the blkdev_issue_flush() helper for a pure cache flush.
+
+
+Forced Unit Access
+-----------------
+
+The REQ_FUA flag can be OR ed into the r/w flags of a bio submitted from the
+filesystem and will make sure that I/O completion for this request is only
+signaled after the data has been committed to non-volatile storage.
+
+
+Implementation details for filesystems
+--------------------------------------
+
+Filesystems can simply set the REQ_FLUSH and REQ_FUA bits and do not have to
+worry if the underlying devices need any explicit cache flushing and how
+the Forced Unit Access is implemented. The REQ_FLUSH and REQ_FUA flags
+may both be set on a single bio.
+
+
+Implementation details for make_request_fn based block drivers
+--------------------------------------------------------------
+
+These drivers will always see the REQ_FLUSH and REQ_FUA bits as they sit
+directly below the submit_bio interface. For remapping drivers the REQ_FUA
+bits need to be propagated to underlying devices, and a global flush needs
+to be implemented for bios with the REQ_FLUSH bit set. For real device
+drivers that do not have a volatile cache the REQ_FLUSH and REQ_FUA bits
+on non-empty bios can simply be ignored, and REQ_FLUSH requests without
+data can be completed successfully without doing any work. Drivers for
+devices with volatile caches need to implement the support for these
+flags themselves without any help from the block layer.
+
+
+Implementation details for request_fn based block drivers
+--------------------------------------------------------------
+
+For devices that do not support volatile write caches there is no driver
+support required, the block layer completes empty REQ_FLUSH requests before
+entering the driver and strips off the REQ_FLUSH and REQ_FUA bits from
+requests that have a payload. For devices with volatile write caches the
+driver needs to tell the block layer that it supports flushing caches by
+doing:
+
+ blk_queue_flush(sdkp->disk->queue, REQ_FLUSH);
+
+and handle empty REQ_FLUSH requests in its prep_fn/request_fn. Note that
+REQ_FLUSH requests with a payload are automatically turned into a sequence
+of an empty REQ_FLUSH request followed by the actual write by the block
+layer. For devices that also support the FUA bit the block layer needs
+to be told to pass through the REQ_FUA bit using:
+
+ blk_queue_flush(sdkp->disk->queue, REQ_FLUSH | REQ_FUA);
+
+and the driver must handle write requests that have the REQ_FUA bit set
+in prep_fn/request_fn. If the FUA bit is not natively supported the block
+layer turns it into an empty REQ_FLUSH request after the actual write.
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 16/41] block: update documentation for REQ_FLUSH / REQ_FUA
2010-09-03 10:29 ` Tejun Heo
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel
Cc: Tejun Heo
From: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
Documentation/block/00-INDEX | 4 +-
Documentation/block/barrier.txt | 261 -----------------------
Documentation/block/writeback_cache_control.txt | 86 ++++++++
3 files changed, 88 insertions(+), 263 deletions(-)
delete mode 100644 Documentation/block/barrier.txt
create mode 100644 Documentation/block/writeback_cache_control.txt
diff --git a/Documentation/block/00-INDEX b/Documentation/block/00-INDEX
index a406286..d111e3b 100644
--- a/Documentation/block/00-INDEX
+++ b/Documentation/block/00-INDEX
@@ -1,7 +1,5 @@
00-INDEX
- This file
-barrier.txt
- - I/O Barriers
biodoc.txt
- Notes on the Generic Block Layer Rewrite in Linux 2.5
capability.txt
@@ -16,3 +14,5 @@ stat.txt
- Block layer statistics in /sys/block/<dev>/stat
switching-sched.txt
- Switching I/O schedulers at runtime
+writeback_cache_control.txt
+ - Control of volatile write back caches
diff --git a/Documentation/block/barrier.txt b/Documentation/block/barrier.txt
deleted file mode 100644
index 2c2f24f..0000000
--- a/Documentation/block/barrier.txt
+++ /dev/null
@@ -1,261 +0,0 @@
-I/O Barriers
-============
-Tejun Heo <htejun@gmail.com>, July 22 2005
-
-I/O barrier requests are used to guarantee ordering around the barrier
-requests. Unless you're crazy enough to use disk drives for
-implementing synchronization constructs (wow, sounds interesting...),
-the ordering is meaningful only for write requests for things like
-journal checkpoints. All requests queued before a barrier request
-must be finished (made it to the physical medium) before the barrier
-request is started, and all requests queued after the barrier request
-must be started only after the barrier request is finished (again,
-made it to the physical medium).
-
-In other words, I/O barrier requests have the following two properties.
-
-1. Request ordering
-
-Requests cannot pass the barrier request. Preceding requests are
-processed before the barrier and following requests after.
-
-Depending on what features a drive supports, this can be done in one
-of the following three ways.
-
-i. For devices which have queue depth greater than 1 (TCQ devices) and
-support ordered tags, block layer can just issue the barrier as an
-ordered request and the lower level driver, controller and drive
-itself are responsible for making sure that the ordering constraint is
-met. Most modern SCSI controllers/drives should support this.
-
-NOTE: SCSI ordered tag isn't currently used due to limitation in the
- SCSI midlayer, see the following random notes section.
-
-ii. For devices which have queue depth greater than 1 but don't
-support ordered tags, block layer ensures that the requests preceding
-a barrier request finishes before issuing the barrier request. Also,
-it defers requests following the barrier until the barrier request is
-finished. Older SCSI controllers/drives and SATA drives fall in this
-category.
-
-iii. Devices which have queue depth of 1. This is a degenerate case
-of ii. Just keeping issue order suffices. Ancient SCSI
-controllers/drives and IDE drives are in this category.
-
-2. Forced flushing to physical medium
-
-Again, if you're not gonna do synchronization with disk drives (dang,
-it sounds even more appealing now!), the reason you use I/O barriers
-is mainly to protect filesystem integrity when power failure or some
-other events abruptly stop the drive from operating and possibly make
-the drive lose data in its cache. So, I/O barriers need to guarantee
-that requests actually get written to non-volatile medium in order.
-
-There are four cases,
-
-i. No write-back cache. Keeping requests ordered is enough.
-
-ii. Write-back cache but no flush operation. There's no way to
-guarantee physical-medium commit order. This kind of devices can't to
-I/O barriers.
-
-iii. Write-back cache and flush operation but no FUA (forced unit
-access). We need two cache flushes - before and after the barrier
-request.
-
-iv. Write-back cache, flush operation and FUA. We still need one
-flush to make sure requests preceding a barrier are written to medium,
-but post-barrier flush can be avoided by using FUA write on the
-barrier itself.
-
-
-How to support barrier requests in drivers
-------------------------------------------
-
-All barrier handling is done inside block layer proper. All low level
-drivers have to are implementing its prepare_flush_fn and using one
-the following two functions to indicate what barrier type it supports
-and how to prepare flush requests. Note that the term 'ordered' is
-used to indicate the whole sequence of performing barrier requests
-including draining and flushing.
-
-typedef void (prepare_flush_fn)(struct request_queue *q, struct request *rq);
-
-int blk_queue_ordered(struct request_queue *q, unsigned ordered,
- prepare_flush_fn *prepare_flush_fn);
-
-@q : the queue in question
-@ordered : the ordered mode the driver/device supports
-@prepare_flush_fn : this function should prepare @rq such that it
- flushes cache to physical medium when executed
-
-For example, SCSI disk driver's prepare_flush_fn looks like the
-following.
-
-static void sd_prepare_flush(struct request_queue *q, struct request *rq)
-{
- memset(rq->cmd, 0, sizeof(rq->cmd));
- rq->cmd_type = REQ_TYPE_BLOCK_PC;
- rq->timeout = SD_TIMEOUT;
- rq->cmd[0] = SYNCHRONIZE_CACHE;
- rq->cmd_len = 10;
-}
-
-The following seven ordered modes are supported. The following table
-shows which mode should be used depending on what features a
-device/driver supports. In the leftmost column of table,
-QUEUE_ORDERED_ prefix is omitted from the mode names to save space.
-
-The table is followed by description of each mode. Note that in the
-descriptions of QUEUE_ORDERED_DRAIN*, '=>' is used whereas '->' is
-used for QUEUE_ORDERED_TAG* descriptions. '=>' indicates that the
-preceding step must be complete before proceeding to the next step.
-'->' indicates that the next step can start as soon as the previous
-step is issued.
-
- write-back cache ordered tag flush FUA
------------------------------------------------------------------------
-NONE yes/no N/A no N/A
-DRAIN no no N/A N/A
-DRAIN_FLUSH yes no yes no
-DRAIN_FUA yes no yes yes
-TAG no yes N/A N/A
-TAG_FLUSH yes yes yes no
-TAG_FUA yes yes yes yes
-
-
-QUEUE_ORDERED_NONE
- I/O barriers are not needed and/or supported.
-
- Sequence: N/A
-
-QUEUE_ORDERED_DRAIN
- Requests are ordered by draining the request queue and cache
- flushing isn't needed.
-
- Sequence: drain => barrier
-
-QUEUE_ORDERED_DRAIN_FLUSH
- Requests are ordered by draining the request queue and both
- pre-barrier and post-barrier cache flushings are needed.
-
- Sequence: drain => preflush => barrier => postflush
-
-QUEUE_ORDERED_DRAIN_FUA
- Requests are ordered by draining the request queue and
- pre-barrier cache flushing is needed. By using FUA on barrier
- request, post-barrier flushing can be skipped.
-
- Sequence: drain => preflush => barrier
-
-QUEUE_ORDERED_TAG
- Requests are ordered by ordered tag and cache flushing isn't
- needed.
-
- Sequence: barrier
-
-QUEUE_ORDERED_TAG_FLUSH
- Requests are ordered by ordered tag and both pre-barrier and
- post-barrier cache flushings are needed.
-
- Sequence: preflush -> barrier -> postflush
-
-QUEUE_ORDERED_TAG_FUA
- Requests are ordered by ordered tag and pre-barrier cache
- flushing is needed. By using FUA on barrier request,
- post-barrier flushing can be skipped.
-
- Sequence: preflush -> barrier
-
-
-Random notes/caveats
---------------------
-
-* SCSI layer currently can't use TAG ordering even if the drive,
-controller and driver support it. The problem is that SCSI midlayer
-request dispatch function is not atomic. It releases queue lock and
-switch to SCSI host lock during issue and it's possible and likely to
-happen in time that requests change their relative positions. Once
-this problem is solved, TAG ordering can be enabled.
-
-* Currently, no matter which ordered mode is used, there can be only
-one barrier request in progress. All I/O barriers are held off by
-block layer until the previous I/O barrier is complete. This doesn't
-make any difference for DRAIN ordered devices, but, for TAG ordered
-devices with very high command latency, passing multiple I/O barriers
-to low level *might* be helpful if they are very frequent. Well, this
-certainly is a non-issue. I'm writing this just to make clear that no
-two I/O barrier is ever passed to low-level driver.
-
-* Completion order. Requests in ordered sequence are issued in order
-but not required to finish in order. Barrier implementation can
-handle out-of-order completion of ordered sequence. IOW, the requests
-MUST be processed in order but the hardware/software completion paths
-are allowed to reorder completion notifications - eg. current SCSI
-midlayer doesn't preserve completion order during error handling.
-
-* Requeueing order. Low-level drivers are free to requeue any request
-after they removed it from the request queue with
-blkdev_dequeue_request(). As barrier sequence should be kept in order
-when requeued, generic elevator code takes care of putting requests in
-order around barrier. See blk_ordered_req_seq() and
-ELEVATOR_INSERT_REQUEUE handling in __elv_add_request() for details.
-
-Note that block drivers must not requeue preceding requests while
-completing latter requests in an ordered sequence. Currently, no
-error checking is done against this.
-
-* Error handling. Currently, block layer will report error to upper
-layer if any of requests in an ordered sequence fails. Unfortunately,
-this doesn't seem to be enough. Look at the following request flow.
-QUEUE_ORDERED_TAG_FLUSH is in use.
-
- [0] [1] [2] [3] [pre] [barrier] [post] < [4] [5] [6] ... >
- still in elevator
-
-Let's say request [2], [3] are write requests to update file system
-metadata (journal or whatever) and [barrier] is used to mark that
-those updates are valid. Consider the following sequence.
-
- i. Requests [0] ~ [post] leaves the request queue and enters
- low-level driver.
- ii. After a while, unfortunately, something goes wrong and the
- drive fails [2]. Note that any of [0], [1] and [3] could have
- completed by this time, but [pre] couldn't have been finished
- as the drive must process it in order and it failed before
- processing that command.
- iii. Error handling kicks in and determines that the error is
- unrecoverable and fails [2], and resumes operation.
- iv. [pre] [barrier] [post] gets processed.
- v. *BOOM* power fails
-
-The problem here is that the barrier request is *supposed* to indicate
-that filesystem update requests [2] and [3] made it safely to the
-physical medium and, if the machine crashes after the barrier is
-written, filesystem recovery code can depend on that. Sadly, that
-isn't true in this case anymore. IOW, the success of a I/O barrier
-should also be dependent on success of some of the preceding requests,
-where only upper layer (filesystem) knows what 'some' is.
-
-This can be solved by implementing a way to tell the block layer which
-requests affect the success of the following barrier request and
-making lower lever drivers to resume operation on error only after
-block layer tells it to do so.
-
-As the probability of this happening is very low and the drive should
-be faulty, implementing the fix is probably an overkill. But, still,
-it's there.
-
-* In previous drafts of barrier implementation, there was fallback
-mechanism such that, if FUA or ordered TAG fails, less fancy ordered
-mode can be selected and the failed barrier request is retried
-automatically. The rationale for this feature was that as FUA is
-pretty new in ATA world and ordered tag was never used widely, there
-could be devices which report to support those features but choke when
-actually given such requests.
-
- This was removed for two reasons 1. it's an overkill 2. it's
-impossible to implement properly when TAG ordering is used as low
-level drivers resume after an error automatically. If it's ever
-needed adding it back and modifying low level drivers accordingly
-shouldn't be difficult.
diff --git a/Documentation/block/writeback_cache_control.txt b/Documentation/block/writeback_cache_control.txt
new file mode 100644
index 0000000..83407d3
--- /dev/null
+++ b/Documentation/block/writeback_cache_control.txt
@@ -0,0 +1,86 @@
+
+Explicit volatile write back cache control
+=====================================
+
+Introduction
+------------
+
+Many storage devices, especially in the consumer market, come with volatile
+write back caches. That means the devices signal I/O completion to the
+operating system before data actually has hit the non-volatile storage. This
+behavior obviously speeds up various workloads, but it means the operating
+system needs to force data out to the non-volatile storage when it performs
+a data integrity operation like fsync, sync or an unmount.
+
+The Linux block layer provides two simple mechanisms that let filesystems
+control the caching behavior of the storage device. These mechanisms are
+a forced cache flush, and the Force Unit Access (FUA) flag for requests.
+
+
+Explicit cache flushes
+----------------------
+
+The REQ_FLUSH flag can be OR ed into the r/w flags of a bio submitted from
+the filesystem and will make sure the volatile cache of the storage device
+has been flushed before the actual I/O operation is started. This explicitly
+guarantees that previously completed write requests are on non-volatile
+storage before the flagged bio starts. In addition the REQ_FLUSH flag can be
+set on an otherwise empty bio structure, which causes only an explicit cache
+flush without any dependent I/O. It is recommend to use
+the blkdev_issue_flush() helper for a pure cache flush.
+
+
+Forced Unit Access
+-----------------
+
+The REQ_FUA flag can be OR ed into the r/w flags of a bio submitted from the
+filesystem and will make sure that I/O completion for this request is only
+signaled after the data has been committed to non-volatile storage.
+
+
+Implementation details for filesystems
+--------------------------------------
+
+Filesystems can simply set the REQ_FLUSH and REQ_FUA bits and do not have to
+worry if the underlying devices need any explicit cache flushing and how
+the Forced Unit Access is implemented. The REQ_FLUSH and REQ_FUA flags
+may both be set on a single bio.
+
+
+Implementation details for make_request_fn based block drivers
+--------------------------------------------------------------
+
+These drivers will always see the REQ_FLUSH and REQ_FUA bits as they sit
+directly below the submit_bio interface. For remapping drivers the REQ_FUA
+bits need to be propagated to underlying devices, and a global flush needs
+to be implemented for bios with the REQ_FLUSH bit set. For real device
+drivers that do not have a volatile cache the REQ_FLUSH and REQ_FUA bits
+on non-empty bios can simply be ignored, and REQ_FLUSH requests without
+data can be completed successfully without doing any work. Drivers for
+devices with volatile caches need to implement the support for these
+flags themselves without any help from the block layer.
+
+
+Implementation details for request_fn based block drivers
+--------------------------------------------------------------
+
+For devices that do not support volatile write caches there is no driver
+support required, the block layer completes empty REQ_FLUSH requests before
+entering the driver and strips off the REQ_FLUSH and REQ_FUA bits from
+requests that have a payload. For devices with volatile write caches the
+driver needs to tell the block layer that it supports flushing caches by
+doing:
+
+ blk_queue_flush(sdkp->disk->queue, REQ_FLUSH);
+
+and handle empty REQ_FLUSH requests in its prep_fn/request_fn. Note that
+REQ_FLUSH requests with a payload are automatically turned into a sequence
+of an empty REQ_FLUSH request followed by the actual write by the block
+layer. For devices that also support the FUA bit the block layer needs
+to be told to pass through the REQ_FUA bit using:
+
+ blk_queue_flush(sdkp->disk->queue, REQ_FLUSH | REQ_FUA);
+
+and the driver must handle write requests that have the REQ_FUA bit set
+in prep_fn/request_fn. If the FUA bit is not natively supported the block
+layer turns it into an empty REQ_FLUSH request after the actual write.
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 16/41] block: update documentation for REQ_FLUSH / REQ_FUA
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo
From: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
Documentation/block/00-INDEX | 4 +-
Documentation/block/barrier.txt | 261 -----------------------
Documentation/block/writeback_cache_control.txt | 86 ++++++++
3 files changed, 88 insertions(+), 263 deletions(-)
delete mode 100644 Documentation/block/barrier.txt
create mode 100644 Documentation/block/writeback_cache_control.txt
diff --git a/Documentation/block/00-INDEX b/Documentation/block/00-INDEX
index a406286..d111e3b 100644
--- a/Documentation/block/00-INDEX
+++ b/Documentation/block/00-INDEX
@@ -1,7 +1,5 @@
00-INDEX
- This file
-barrier.txt
- - I/O Barriers
biodoc.txt
- Notes on the Generic Block Layer Rewrite in Linux 2.5
capability.txt
@@ -16,3 +14,5 @@ stat.txt
- Block layer statistics in /sys/block/<dev>/stat
switching-sched.txt
- Switching I/O schedulers at runtime
+writeback_cache_control.txt
+ - Control of volatile write back caches
diff --git a/Documentation/block/barrier.txt b/Documentation/block/barrier.txt
deleted file mode 100644
index 2c2f24f..0000000
--- a/Documentation/block/barrier.txt
+++ /dev/null
@@ -1,261 +0,0 @@
-I/O Barriers
-============
-Tejun Heo <htejun@gmail.com>, July 22 2005
-
-I/O barrier requests are used to guarantee ordering around the barrier
-requests. Unless you're crazy enough to use disk drives for
-implementing synchronization constructs (wow, sounds interesting...),
-the ordering is meaningful only for write requests for things like
-journal checkpoints. All requests queued before a barrier request
-must be finished (made it to the physical medium) before the barrier
-request is started, and all requests queued after the barrier request
-must be started only after the barrier request is finished (again,
-made it to the physical medium).
-
-In other words, I/O barrier requests have the following two properties.
-
-1. Request ordering
-
-Requests cannot pass the barrier request. Preceding requests are
-processed before the barrier and following requests after.
-
-Depending on what features a drive supports, this can be done in one
-of the following three ways.
-
-i. For devices which have queue depth greater than 1 (TCQ devices) and
-support ordered tags, block layer can just issue the barrier as an
-ordered request and the lower level driver, controller and drive
-itself are responsible for making sure that the ordering constraint is
-met. Most modern SCSI controllers/drives should support this.
-
-NOTE: SCSI ordered tag isn't currently used due to limitation in the
- SCSI midlayer, see the following random notes section.
-
-ii. For devices which have queue depth greater than 1 but don't
-support ordered tags, block layer ensures that the requests preceding
-a barrier request finishes before issuing the barrier request. Also,
-it defers requests following the barrier until the barrier request is
-finished. Older SCSI controllers/drives and SATA drives fall in this
-category.
-
-iii. Devices which have queue depth of 1. This is a degenerate case
-of ii. Just keeping issue order suffices. Ancient SCSI
-controllers/drives and IDE drives are in this category.
-
-2. Forced flushing to physical medium
-
-Again, if you're not gonna do synchronization with disk drives (dang,
-it sounds even more appealing now!), the reason you use I/O barriers
-is mainly to protect filesystem integrity when power failure or some
-other events abruptly stop the drive from operating and possibly make
-the drive lose data in its cache. So, I/O barriers need to guarantee
-that requests actually get written to non-volatile medium in order.
-
-There are four cases,
-
-i. No write-back cache. Keeping requests ordered is enough.
-
-ii. Write-back cache but no flush operation. There's no way to
-guarantee physical-medium commit order. This kind of devices can't to
-I/O barriers.
-
-iii. Write-back cache and flush operation but no FUA (forced unit
-access). We need two cache flushes - before and after the barrier
-request.
-
-iv. Write-back cache, flush operation and FUA. We still need one
-flush to make sure requests preceding a barrier are written to medium,
-but post-barrier flush can be avoided by using FUA write on the
-barrier itself.
-
-
-How to support barrier requests in drivers
-------------------------------------------
-
-All barrier handling is done inside block layer proper. All low level
-drivers have to are implementing its prepare_flush_fn and using one
-the following two functions to indicate what barrier type it supports
-and how to prepare flush requests. Note that the term 'ordered' is
-used to indicate the whole sequence of performing barrier requests
-including draining and flushing.
-
-typedef void (prepare_flush_fn)(struct request_queue *q, struct request *rq);
-
-int blk_queue_ordered(struct request_queue *q, unsigned ordered,
- prepare_flush_fn *prepare_flush_fn);
-
-@q : the queue in question
-@ordered : the ordered mode the driver/device supports
-@prepare_flush_fn : this function should prepare @rq such that it
- flushes cache to physical medium when executed
-
-For example, SCSI disk driver's prepare_flush_fn looks like the
-following.
-
-static void sd_prepare_flush(struct request_queue *q, struct request *rq)
-{
- memset(rq->cmd, 0, sizeof(rq->cmd));
- rq->cmd_type = REQ_TYPE_BLOCK_PC;
- rq->timeout = SD_TIMEOUT;
- rq->cmd[0] = SYNCHRONIZE_CACHE;
- rq->cmd_len = 10;
-}
-
-The following seven ordered modes are supported. The following table
-shows which mode should be used depending on what features a
-device/driver supports. In the leftmost column of table,
-QUEUE_ORDERED_ prefix is omitted from the mode names to save space.
-
-The table is followed by description of each mode. Note that in the
-descriptions of QUEUE_ORDERED_DRAIN*, '=>' is used whereas '->' is
-used for QUEUE_ORDERED_TAG* descriptions. '=>' indicates that the
-preceding step must be complete before proceeding to the next step.
-'->' indicates that the next step can start as soon as the previous
-step is issued.
-
- write-back cache ordered tag flush FUA
------------------------------------------------------------------------
-NONE yes/no N/A no N/A
-DRAIN no no N/A N/A
-DRAIN_FLUSH yes no yes no
-DRAIN_FUA yes no yes yes
-TAG no yes N/A N/A
-TAG_FLUSH yes yes yes no
-TAG_FUA yes yes yes yes
-
-
-QUEUE_ORDERED_NONE
- I/O barriers are not needed and/or supported.
-
- Sequence: N/A
-
-QUEUE_ORDERED_DRAIN
- Requests are ordered by draining the request queue and cache
- flushing isn't needed.
-
- Sequence: drain => barrier
-
-QUEUE_ORDERED_DRAIN_FLUSH
- Requests are ordered by draining the request queue and both
- pre-barrier and post-barrier cache flushings are needed.
-
- Sequence: drain => preflush => barrier => postflush
-
-QUEUE_ORDERED_DRAIN_FUA
- Requests are ordered by draining the request queue and
- pre-barrier cache flushing is needed. By using FUA on barrier
- request, post-barrier flushing can be skipped.
-
- Sequence: drain => preflush => barrier
-
-QUEUE_ORDERED_TAG
- Requests are ordered by ordered tag and cache flushing isn't
- needed.
-
- Sequence: barrier
-
-QUEUE_ORDERED_TAG_FLUSH
- Requests are ordered by ordered tag and both pre-barrier and
- post-barrier cache flushings are needed.
-
- Sequence: preflush -> barrier -> postflush
-
-QUEUE_ORDERED_TAG_FUA
- Requests are ordered by ordered tag and pre-barrier cache
- flushing is needed. By using FUA on barrier request,
- post-barrier flushing can be skipped.
-
- Sequence: preflush -> barrier
-
-
-Random notes/caveats
---------------------
-
-* SCSI layer currently can't use TAG ordering even if the drive,
-controller and driver support it. The problem is that SCSI midlayer
-request dispatch function is not atomic. It releases queue lock and
-switch to SCSI host lock during issue and it's possible and likely to
-happen in time that requests change their relative positions. Once
-this problem is solved, TAG ordering can be enabled.
-
-* Currently, no matter which ordered mode is used, there can be only
-one barrier request in progress. All I/O barriers are held off by
-block layer until the previous I/O barrier is complete. This doesn't
-make any difference for DRAIN ordered devices, but, for TAG ordered
-devices with very high command latency, passing multiple I/O barriers
-to low level *might* be helpful if they are very frequent. Well, this
-certainly is a non-issue. I'm writing this just to make clear that no
-two I/O barrier is ever passed to low-level driver.
-
-* Completion order. Requests in ordered sequence are issued in order
-but not required to finish in order. Barrier implementation can
-handle out-of-order completion of ordered sequence. IOW, the requests
-MUST be processed in order but the hardware/software completion paths
-are allowed to reorder completion notifications - eg. current SCSI
-midlayer doesn't preserve completion order during error handling.
-
-* Requeueing order. Low-level drivers are free to requeue any request
-after they removed it from the request queue with
-blkdev_dequeue_request(). As barrier sequence should be kept in order
-when requeued, generic elevator code takes care of putting requests in
-order around barrier. See blk_ordered_req_seq() and
-ELEVATOR_INSERT_REQUEUE handling in __elv_add_request() for details.
-
-Note that block drivers must not requeue preceding requests while
-completing latter requests in an ordered sequence. Currently, no
-error checking is done against this.
-
-* Error handling. Currently, block layer will report error to upper
-layer if any of requests in an ordered sequence fails. Unfortunately,
-this doesn't seem to be enough. Look at the following request flow.
-QUEUE_ORDERED_TAG_FLUSH is in use.
-
- [0] [1] [2] [3] [pre] [barrier] [post] < [4] [5] [6] ... >
- still in elevator
-
-Let's say request [2], [3] are write requests to update file system
-metadata (journal or whatever) and [barrier] is used to mark that
-those updates are valid. Consider the following sequence.
-
- i. Requests [0] ~ [post] leaves the request queue and enters
- low-level driver.
- ii. After a while, unfortunately, something goes wrong and the
- drive fails [2]. Note that any of [0], [1] and [3] could have
- completed by this time, but [pre] couldn't have been finished
- as the drive must process it in order and it failed before
- processing that command.
- iii. Error handling kicks in and determines that the error is
- unrecoverable and fails [2], and resumes operation.
- iv. [pre] [barrier] [post] gets processed.
- v. *BOOM* power fails
-
-The problem here is that the barrier request is *supposed* to indicate
-that filesystem update requests [2] and [3] made it safely to the
-physical medium and, if the machine crashes after the barrier is
-written, filesystem recovery code can depend on that. Sadly, that
-isn't true in this case anymore. IOW, the success of a I/O barrier
-should also be dependent on success of some of the preceding requests,
-where only upper layer (filesystem) knows what 'some' is.
-
-This can be solved by implementing a way to tell the block layer which
-requests affect the success of the following barrier request and
-making lower lever drivers to resume operation on error only after
-block layer tells it to do so.
-
-As the probability of this happening is very low and the drive should
-be faulty, implementing the fix is probably an overkill. But, still,
-it's there.
-
-* In previous drafts of barrier implementation, there was fallback
-mechanism such that, if FUA or ordered TAG fails, less fancy ordered
-mode can be selected and the failed barrier request is retried
-automatically. The rationale for this feature was that as FUA is
-pretty new in ATA world and ordered tag was never used widely, there
-could be devices which report to support those features but choke when
-actually given such requests.
-
- This was removed for two reasons 1. it's an overkill 2. it's
-impossible to implement properly when TAG ordering is used as low
-level drivers resume after an error automatically. If it's ever
-needed adding it back and modifying low level drivers accordingly
-shouldn't be difficult.
diff --git a/Documentation/block/writeback_cache_control.txt b/Documentation/block/writeback_cache_control.txt
new file mode 100644
index 0000000..83407d3
--- /dev/null
+++ b/Documentation/block/writeback_cache_control.txt
@@ -0,0 +1,86 @@
+
+Explicit volatile write back cache control
+=====================================
+
+Introduction
+------------
+
+Many storage devices, especially in the consumer market, come with volatile
+write back caches. That means the devices signal I/O completion to the
+operating system before data actually has hit the non-volatile storage. This
+behavior obviously speeds up various workloads, but it means the operating
+system needs to force data out to the non-volatile storage when it performs
+a data integrity operation like fsync, sync or an unmount.
+
+The Linux block layer provides two simple mechanisms that let filesystems
+control the caching behavior of the storage device. These mechanisms are
+a forced cache flush, and the Force Unit Access (FUA) flag for requests.
+
+
+Explicit cache flushes
+----------------------
+
+The REQ_FLUSH flag can be OR ed into the r/w flags of a bio submitted from
+the filesystem and will make sure the volatile cache of the storage device
+has been flushed before the actual I/O operation is started. This explicitly
+guarantees that previously completed write requests are on non-volatile
+storage before the flagged bio starts. In addition the REQ_FLUSH flag can be
+set on an otherwise empty bio structure, which causes only an explicit cache
+flush without any dependent I/O. It is recommend to use
+the blkdev_issue_flush() helper for a pure cache flush.
+
+
+Forced Unit Access
+-----------------
+
+The REQ_FUA flag can be OR ed into the r/w flags of a bio submitted from the
+filesystem and will make sure that I/O completion for this request is only
+signaled after the data has been committed to non-volatile storage.
+
+
+Implementation details for filesystems
+--------------------------------------
+
+Filesystems can simply set the REQ_FLUSH and REQ_FUA bits and do not have to
+worry if the underlying devices need any explicit cache flushing and how
+the Forced Unit Access is implemented. The REQ_FLUSH and REQ_FUA flags
+may both be set on a single bio.
+
+
+Implementation details for make_request_fn based block drivers
+--------------------------------------------------------------
+
+These drivers will always see the REQ_FLUSH and REQ_FUA bits as they sit
+directly below the submit_bio interface. For remapping drivers the REQ_FUA
+bits need to be propagated to underlying devices, and a global flush needs
+to be implemented for bios with the REQ_FLUSH bit set. For real device
+drivers that do not have a volatile cache the REQ_FLUSH and REQ_FUA bits
+on non-empty bios can simply be ignored, and REQ_FLUSH requests without
+data can be completed successfully without doing any work. Drivers for
+devices with volatile caches need to implement the support for these
+flags themselves without any help from the block layer.
+
+
+Implementation details for request_fn based block drivers
+--------------------------------------------------------------
+
+For devices that do not support volatile write caches there is no driver
+support required, the block layer completes empty REQ_FLUSH requests before
+entering the driver and strips off the REQ_FLUSH and REQ_FUA bits from
+requests that have a payload. For devices with volatile write caches the
+driver needs to tell the block layer that it supports flushing caches by
+doing:
+
+ blk_queue_flush(sdkp->disk->queue, REQ_FLUSH);
+
+and handle empty REQ_FLUSH requests in its prep_fn/request_fn. Note that
+REQ_FLUSH requests with a payload are automatically turned into a sequence
+of an empty REQ_FLUSH request followed by the actual write by the block
+layer. For devices that also support the FUA bit the block layer needs
+to be told to pass through the REQ_FUA bit using:
+
+ blk_queue_flush(sdkp->disk->queue, REQ_FLUSH | REQ_FUA);
+
+and the driver must handle write requests that have the REQ_FUA bit set
+in prep_fn/request_fn. If the FUA bit is not natively supported the block
+layer turns it into an empty REQ_FLUSH request after the actual write.
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 17/41] block: use REQ_FLUSH in blkdev_issue_flush()
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo, Christoph Hellwig
Update blkdev_issue_flush() to use new REQ_FLUSH interface.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
---
block/blk-flush.c | 17 ++++++-----------
1 files changed, 6 insertions(+), 11 deletions(-)
diff --git a/block/blk-flush.c b/block/blk-flush.c
index 7d1fc98..62b7df9 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -191,13 +191,10 @@ struct request *blk_do_flush(struct request_queue *q, struct request *rq)
return blk_flush_complete_seq(q, skip, 0);
}
-static void bio_end_empty_barrier(struct bio *bio, int err)
+static void bio_end_flush(struct bio *bio, int err)
{
- if (err) {
- if (err == -EOPNOTSUPP)
- set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
+ if (err)
clear_bit(BIO_UPTODATE, &bio->bi_flags);
- }
if (bio->bi_private)
complete(bio->bi_private);
bio_put(bio);
@@ -235,19 +232,19 @@ int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
* some block devices may not have their queue correctly set up here
* (e.g. loop device without a backing file) and so issuing a flush
* here will panic. Ensure there is a request function before issuing
- * the barrier.
+ * the flush.
*/
if (!q->make_request_fn)
return -ENXIO;
bio = bio_alloc(gfp_mask, 0);
- bio->bi_end_io = bio_end_empty_barrier;
+ bio->bi_end_io = bio_end_flush;
bio->bi_bdev = bdev;
if (test_bit(BLKDEV_WAIT, &flags))
bio->bi_private = &wait;
bio_get(bio);
- submit_bio(WRITE_BARRIER, bio);
+ submit_bio(WRITE_FLUSH, bio);
if (test_bit(BLKDEV_WAIT, &flags)) {
wait_for_completion(&wait);
/*
@@ -259,9 +256,7 @@ int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
*error_sector = bio->bi_sector;
}
- if (bio_flagged(bio, BIO_EOPNOTSUPP))
- ret = -EOPNOTSUPP;
- else if (!bio_flagged(bio, BIO_UPTODATE))
+ if (!bio_flagged(bio, BIO_UPTODATE))
ret = -EIO;
bio_put(bio);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 17/41] block: use REQ_FLUSH in blkdev_issue_flush()
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo, Christoph Hellwig
Update blkdev_issue_flush() to use new REQ_FLUSH interface.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
---
block/blk-flush.c | 17 ++++++-----------
1 files changed, 6 insertions(+), 11 deletions(-)
diff --git a/block/blk-flush.c b/block/blk-flush.c
index 7d1fc98..62b7df9 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -191,13 +191,10 @@ struct request *blk_do_flush(struct request_queue *q, struct request *rq)
return blk_flush_complete_seq(q, skip, 0);
}
-static void bio_end_empty_barrier(struct bio *bio, int err)
+static void bio_end_flush(struct bio *bio, int err)
{
- if (err) {
- if (err == -EOPNOTSUPP)
- set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
+ if (err)
clear_bit(BIO_UPTODATE, &bio->bi_flags);
- }
if (bio->bi_private)
complete(bio->bi_private);
bio_put(bio);
@@ -235,19 +232,19 @@ int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
* some block devices may not have their queue correctly set up here
* (e.g. loop device without a backing file) and so issuing a flush
* here will panic. Ensure there is a request function before issuing
- * the barrier.
+ * the flush.
*/
if (!q->make_request_fn)
return -ENXIO;
bio = bio_alloc(gfp_mask, 0);
- bio->bi_end_io = bio_end_empty_barrier;
+ bio->bi_end_io = bio_end_flush;
bio->bi_bdev = bdev;
if (test_bit(BLKDEV_WAIT, &flags))
bio->bi_private = &wait;
bio_get(bio);
- submit_bio(WRITE_BARRIER, bio);
+ submit_bio(WRITE_FLUSH, bio);
if (test_bit(BLKDEV_WAIT, &flags)) {
wait_for_completion(&wait);
/*
@@ -259,9 +256,7 @@ int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
*error_sector = bio->bi_sector;
}
- if (bio_flagged(bio, BIO_EOPNOTSUPP))
- ret = -EOPNOTSUPP;
- else if (!bio_flagged(bio, BIO_UPTODATE))
+ if (!bio_flagged(bio, BIO_UPTODATE))
ret = -EIO;
bio_put(bio);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 17/41] block: use REQ_FLUSH in blkdev_issue_flush()
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo, Christoph Hellwig
Update blkdev_issue_flush() to use new REQ_FLUSH interface.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
---
block/blk-flush.c | 17 ++++++-----------
1 files changed, 6 insertions(+), 11 deletions(-)
diff --git a/block/blk-flush.c b/block/blk-flush.c
index 7d1fc98..62b7df9 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -191,13 +191,10 @@ struct request *blk_do_flush(struct request_queue *q, struct request *rq)
return blk_flush_complete_seq(q, skip, 0);
}
-static void bio_end_empty_barrier(struct bio *bio, int err)
+static void bio_end_flush(struct bio *bio, int err)
{
- if (err) {
- if (err == -EOPNOTSUPP)
- set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
+ if (err)
clear_bit(BIO_UPTODATE, &bio->bi_flags);
- }
if (bio->bi_private)
complete(bio->bi_private);
bio_put(bio);
@@ -235,19 +232,19 @@ int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
* some block devices may not have their queue correctly set up here
* (e.g. loop device without a backing file) and so issuing a flush
* here will panic. Ensure there is a request function before issuing
- * the barrier.
+ * the flush.
*/
if (!q->make_request_fn)
return -ENXIO;
bio = bio_alloc(gfp_mask, 0);
- bio->bi_end_io = bio_end_empty_barrier;
+ bio->bi_end_io = bio_end_flush;
bio->bi_bdev = bdev;
if (test_bit(BLKDEV_WAIT, &flags))
bio->bi_private = &wait;
bio_get(bio);
- submit_bio(WRITE_BARRIER, bio);
+ submit_bio(WRITE_FLUSH, bio);
if (test_bit(BLKDEV_WAIT, &flags)) {
wait_for_completion(&wait);
/*
@@ -259,9 +256,7 @@ int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
*error_sector = bio->bi_sector;
}
- if (bio_flagged(bio, BIO_EOPNOTSUPP))
- ret = -EOPNOTSUPP;
- else if (!bio_flagged(bio, BIO_UPTODATE))
+ if (!bio_flagged(bio, BIO_UPTODATE))
ret = -EIO;
bio_put(bio);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 18/41] block/loop: implement REQ_FLUSH/FUA support
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
Deprecate REQ_HARDBARRIER and implement REQ_FLUSH/FUA instead. Also,
instead of checking file->f_op->fsync() directly, look at the value of
vfs_fsync() and ignore -EINVAL return.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
drivers/block/loop.c | 18 +++++++++---------
1 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 953d1e1..5d27bc6 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -477,17 +477,17 @@ static int do_bio_filebacked(struct loop_device *lo, struct bio *bio)
pos = ((loff_t) bio->bi_sector << 9) + lo->lo_offset;
if (bio_rw(bio) == WRITE) {
- bool barrier = (bio->bi_rw & REQ_HARDBARRIER);
struct file *file = lo->lo_backing_file;
- if (barrier) {
- if (unlikely(!file->f_op->fsync)) {
- ret = -EOPNOTSUPP;
- goto out;
- }
+ /* REQ_HARDBARRIER is deprecated */
+ if (bio->bi_rw & REQ_HARDBARRIER) {
+ ret = -EOPNOTSUPP;
+ goto out;
+ }
+ if (bio->bi_rw & REQ_FLUSH) {
ret = vfs_fsync(file, 0);
- if (unlikely(ret)) {
+ if (unlikely(ret && ret != -EINVAL)) {
ret = -EIO;
goto out;
}
@@ -495,9 +495,9 @@ static int do_bio_filebacked(struct loop_device *lo, struct bio *bio)
ret = lo_send(lo, bio, pos);
- if (barrier && !ret) {
+ if ((bio->bi_rw & REQ_FUA) && !ret) {
ret = vfs_fsync(file, 0);
- if (unlikely(ret))
+ if (unlikely(ret && ret != -EINVAL))
ret = -EIO;
}
} else
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 18/41] block/loop: implement REQ_FLUSH/FUA support
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
Deprecate REQ_HARDBARRIER and implement REQ_FLUSH/FUA instead. Also,
instead of checking file->f_op->fsync() directly, look at the value of
vfs_fsync() and ignore -EINVAL return.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
drivers/block/loop.c | 18 +++++++++---------
1 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 953d1e1..5d27bc6 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -477,17 +477,17 @@ static int do_bio_filebacked(struct loop_device *lo, struct bio *bio)
pos = ((loff_t) bio->bi_sector << 9) + lo->lo_offset;
if (bio_rw(bio) == WRITE) {
- bool barrier = (bio->bi_rw & REQ_HARDBARRIER);
struct file *file = lo->lo_backing_file;
- if (barrier) {
- if (unlikely(!file->f_op->fsync)) {
- ret = -EOPNOTSUPP;
- goto out;
- }
+ /* REQ_HARDBARRIER is deprecated */
+ if (bio->bi_rw & REQ_HARDBARRIER) {
+ ret = -EOPNOTSUPP;
+ goto out;
+ }
+ if (bio->bi_rw & REQ_FLUSH) {
ret = vfs_fsync(file, 0);
- if (unlikely(ret)) {
+ if (unlikely(ret && ret != -EINVAL)) {
ret = -EIO;
goto out;
}
@@ -495,9 +495,9 @@ static int do_bio_filebacked(struct loop_device *lo, struct bio *bio)
ret = lo_send(lo, bio, pos);
- if (barrier && !ret) {
+ if ((bio->bi_rw & REQ_FUA) && !ret) {
ret = vfs_fsync(file, 0);
- if (unlikely(ret))
+ if (unlikely(ret && ret != -EINVAL))
ret = -EIO;
}
} else
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 18/41] block/loop: implement REQ_FLUSH/FUA support
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo
Deprecate REQ_HARDBARRIER and implement REQ_FLUSH/FUA instead. Also,
instead of checking file->f_op->fsync() directly, look at the value of
vfs_fsync() and ignore -EINVAL return.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
drivers/block/loop.c | 18 +++++++++---------
1 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 953d1e1..5d27bc6 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -477,17 +477,17 @@ static int do_bio_filebacked(struct loop_device *lo, struct bio *bio)
pos = ((loff_t) bio->bi_sector << 9) + lo->lo_offset;
if (bio_rw(bio) == WRITE) {
- bool barrier = (bio->bi_rw & REQ_HARDBARRIER);
struct file *file = lo->lo_backing_file;
- if (barrier) {
- if (unlikely(!file->f_op->fsync)) {
- ret = -EOPNOTSUPP;
- goto out;
- }
+ /* REQ_HARDBARRIER is deprecated */
+ if (bio->bi_rw & REQ_HARDBARRIER) {
+ ret = -EOPNOTSUPP;
+ goto out;
+ }
+ if (bio->bi_rw & REQ_FLUSH) {
ret = vfs_fsync(file, 0);
- if (unlikely(ret)) {
+ if (unlikely(ret && ret != -EINVAL)) {
ret = -EIO;
goto out;
}
@@ -495,9 +495,9 @@ static int do_bio_filebacked(struct loop_device *lo, struct bio *bio)
ret = lo_send(lo, bio, pos);
- if (barrier && !ret) {
+ if ((bio->bi_rw & REQ_FUA) && !ret) {
ret = vfs_fsync(file, 0);
- if (unlikely(ret))
+ if (unlikely(ret && ret != -EINVAL))
ret = -EIO;
}
} else
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 19/41] virtio_blk: drop REQ_HARDBARRIER support
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
Remove now unused REQ_HARDBARRIER support. virtio_blk already
supports REQ_FLUSH and the usefulness of REQ_FUA for virtio_blk is
questionable at this point, so there's nothing else to do to support
new REQ_FLUSH/FUA interface.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
---
drivers/block/virtio_blk.c | 17 ++++-------------
1 files changed, 4 insertions(+), 13 deletions(-)
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index d10b635..1260628 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -128,9 +128,6 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
}
}
- if (vbr->req->cmd_flags & REQ_HARDBARRIER)
- vbr->out_hdr.type |= VIRTIO_BLK_T_BARRIER;
-
sg_set_buf(&vblk->sg[out++], &vbr->out_hdr, sizeof(vbr->out_hdr));
/*
@@ -388,13 +385,7 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
vblk->disk->driverfs_dev = &vdev->dev;
index++;
- /*
- * If the FLUSH feature is supported we do have support for
- * flushing a volatile write cache on the host. Use that to
- * implement write barrier support; otherwise, we must assume
- * that the host does not perform any kind of volatile write
- * caching.
- */
+ /* configure queue flush support */
if (virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH))
blk_queue_flush(q, REQ_FLUSH);
@@ -515,9 +506,9 @@ static const struct virtio_device_id id_table[] = {
};
static unsigned int features[] = {
- VIRTIO_BLK_F_BARRIER, VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX,
- VIRTIO_BLK_F_GEOMETRY, VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
- VIRTIO_BLK_F_SCSI, VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY
+ VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
+ VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, VIRTIO_BLK_F_SCSI,
+ VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY
};
/*
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 19/41] virtio_blk: drop REQ_HARDBARRIER support
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
Remove now unused REQ_HARDBARRIER support. virtio_blk already
supports REQ_FLUSH and the usefulness of REQ_FUA for virtio_blk is
questionable at this point, so there's nothing else to do to support
new REQ_FLUSH/FUA interface.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
---
drivers/block/virtio_blk.c | 17 ++++-------------
1 files changed, 4 insertions(+), 13 deletions(-)
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index d10b635..1260628 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -128,9 +128,6 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
}
}
- if (vbr->req->cmd_flags & REQ_HARDBARRIER)
- vbr->out_hdr.type |= VIRTIO_BLK_T_BARRIER;
-
sg_set_buf(&vblk->sg[out++], &vbr->out_hdr, sizeof(vbr->out_hdr));
/*
@@ -388,13 +385,7 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
vblk->disk->driverfs_dev = &vdev->dev;
index++;
- /*
- * If the FLUSH feature is supported we do have support for
- * flushing a volatile write cache on the host. Use that to
- * implement write barrier support; otherwise, we must assume
- * that the host does not perform any kind of volatile write
- * caching.
- */
+ /* configure queue flush support */
if (virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH))
blk_queue_flush(q, REQ_FLUSH);
@@ -515,9 +506,9 @@ static const struct virtio_device_id id_table[] = {
};
static unsigned int features[] = {
- VIRTIO_BLK_F_BARRIER, VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX,
- VIRTIO_BLK_F_GEOMETRY, VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
- VIRTIO_BLK_F_SCSI, VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY
+ VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
+ VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, VIRTIO_BLK_F_SCSI,
+ VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY
};
/*
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 19/41] virtio_blk: drop REQ_HARDBARRIER support
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo
Remove now unused REQ_HARDBARRIER support. virtio_blk already
supports REQ_FLUSH and the usefulness of REQ_FUA for virtio_blk is
questionable at this point, so there's nothing else to do to support
new REQ_FLUSH/FUA interface.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
---
drivers/block/virtio_blk.c | 17 ++++-------------
1 files changed, 4 insertions(+), 13 deletions(-)
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index d10b635..1260628 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -128,9 +128,6 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
}
}
- if (vbr->req->cmd_flags & REQ_HARDBARRIER)
- vbr->out_hdr.type |= VIRTIO_BLK_T_BARRIER;
-
sg_set_buf(&vblk->sg[out++], &vbr->out_hdr, sizeof(vbr->out_hdr));
/*
@@ -388,13 +385,7 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
vblk->disk->driverfs_dev = &vdev->dev;
index++;
- /*
- * If the FLUSH feature is supported we do have support for
- * flushing a volatile write cache on the host. Use that to
- * implement write barrier support; otherwise, we must assume
- * that the host does not perform any kind of volatile write
- * caching.
- */
+ /* configure queue flush support */
if (virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH))
blk_queue_flush(q, REQ_FLUSH);
@@ -515,9 +506,9 @@ static const struct virtio_device_id id_table[] = {
};
static unsigned int features[] = {
- VIRTIO_BLK_F_BARRIER, VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX,
- VIRTIO_BLK_F_GEOMETRY, VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
- VIRTIO_BLK_F_SCSI, VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY
+ VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
+ VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, VIRTIO_BLK_F_SCSI,
+ VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY
};
/*
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 20/41] lguest: replace VIRTIO_F_BARRIER support with VIRTIO_F_FLUSH support
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
VIRTIO_F_BARRIER is deprecated. Replace it with VIRTIO_F_FLUSH
support.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Christoph Hellwig <hch@lst.de>
---
Documentation/lguest/lguest.c | 29 +++++++++--------------------
1 files changed, 9 insertions(+), 20 deletions(-)
diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c
index 8a6a8c6..dc73bc5 100644
--- a/Documentation/lguest/lguest.c
+++ b/Documentation/lguest/lguest.c
@@ -1640,15 +1640,6 @@ static void blk_request(struct virtqueue *vq)
off = out->sector * 512;
/*
- * The block device implements "barriers", where the Guest indicates
- * that it wants all previous writes to occur before this write. We
- * don't have a way of asking our kernel to do a barrier, so we just
- * synchronize all the data in the file. Pretty poor, no?
- */
- if (out->type & VIRTIO_BLK_T_BARRIER)
- fdatasync(vblk->fd);
-
- /*
* In general the virtio block driver is allowed to try SCSI commands.
* It'd be nice if we supported eject, for example, but we don't.
*/
@@ -1680,6 +1671,13 @@ static void blk_request(struct virtqueue *vq)
/* Die, bad Guest, die. */
errx(1, "Write past end %llu+%u", off, ret);
}
+
+ wlen = sizeof(*in);
+ *in = (ret >= 0 ? VIRTIO_BLK_S_OK : VIRTIO_BLK_S_IOERR);
+ } else if (out->type & VIRTIO_BLK_T_FLUSH) {
+ /* Flush */
+ ret = fdatasync(vblk->fd);
+ verbose("FLUSH fdatasync: %i\n", ret);
wlen = sizeof(*in);
*in = (ret >= 0 ? VIRTIO_BLK_S_OK : VIRTIO_BLK_S_IOERR);
} else {
@@ -1703,15 +1701,6 @@ static void blk_request(struct virtqueue *vq)
}
}
- /*
- * OK, so we noted that it was pretty poor to use an fdatasync as a
- * barrier. But Christoph Hellwig points out that we need a sync
- * *afterwards* as well: "Barriers specify no reordering to the front
- * or the back." And Jens Axboe confirmed it, so here we are:
- */
- if (out->type & VIRTIO_BLK_T_BARRIER)
- fdatasync(vblk->fd);
-
/* Finished that request. */
add_used(vq, head, wlen);
}
@@ -1736,8 +1725,8 @@ static void setup_block_file(const char *filename)
vblk->fd = open_or_die(filename, O_RDWR|O_LARGEFILE);
vblk->len = lseek64(vblk->fd, 0, SEEK_END);
- /* We support barriers. */
- add_feature(dev, VIRTIO_BLK_F_BARRIER);
+ /* We support FLUSH. */
+ add_feature(dev, VIRTIO_BLK_F_FLUSH);
/* Tell Guest how many sectors this device has. */
conf.capacity = cpu_to_le64(vblk->len / 512);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 20/41] lguest: replace VIRTIO_F_BARRIER support with VIRTIO_F_FLUSH support
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
VIRTIO_F_BARRIER is deprecated. Replace it with VIRTIO_F_FLUSH
support.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Christoph Hellwig <hch@lst.de>
---
Documentation/lguest/lguest.c | 29 +++++++++--------------------
1 files changed, 9 insertions(+), 20 deletions(-)
diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c
index 8a6a8c6..dc73bc5 100644
--- a/Documentation/lguest/lguest.c
+++ b/Documentation/lguest/lguest.c
@@ -1640,15 +1640,6 @@ static void blk_request(struct virtqueue *vq)
off = out->sector * 512;
/*
- * The block device implements "barriers", where the Guest indicates
- * that it wants all previous writes to occur before this write. We
- * don't have a way of asking our kernel to do a barrier, so we just
- * synchronize all the data in the file. Pretty poor, no?
- */
- if (out->type & VIRTIO_BLK_T_BARRIER)
- fdatasync(vblk->fd);
-
- /*
* In general the virtio block driver is allowed to try SCSI commands.
* It'd be nice if we supported eject, for example, but we don't.
*/
@@ -1680,6 +1671,13 @@ static void blk_request(struct virtqueue *vq)
/* Die, bad Guest, die. */
errx(1, "Write past end %llu+%u", off, ret);
}
+
+ wlen = sizeof(*in);
+ *in = (ret >= 0 ? VIRTIO_BLK_S_OK : VIRTIO_BLK_S_IOERR);
+ } else if (out->type & VIRTIO_BLK_T_FLUSH) {
+ /* Flush */
+ ret = fdatasync(vblk->fd);
+ verbose("FLUSH fdatasync: %i\n", ret);
wlen = sizeof(*in);
*in = (ret >= 0 ? VIRTIO_BLK_S_OK : VIRTIO_BLK_S_IOERR);
} else {
@@ -1703,15 +1701,6 @@ static void blk_request(struct virtqueue *vq)
}
}
- /*
- * OK, so we noted that it was pretty poor to use an fdatasync as a
- * barrier. But Christoph Hellwig points out that we need a sync
- * *afterwards* as well: "Barriers specify no reordering to the front
- * or the back." And Jens Axboe confirmed it, so here we are:
- */
- if (out->type & VIRTIO_BLK_T_BARRIER)
- fdatasync(vblk->fd);
-
/* Finished that request. */
add_used(vq, head, wlen);
}
@@ -1736,8 +1725,8 @@ static void setup_block_file(const char *filename)
vblk->fd = open_or_die(filename, O_RDWR|O_LARGEFILE);
vblk->len = lseek64(vblk->fd, 0, SEEK_END);
- /* We support barriers. */
- add_feature(dev, VIRTIO_BLK_F_BARRIER);
+ /* We support FLUSH. */
+ add_feature(dev, VIRTIO_BLK_F_FLUSH);
/* Tell Guest how many sectors this device has. */
conf.capacity = cpu_to_le64(vblk->len / 512);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 20/41] lguest: replace VIRTIO_F_BARRIER support with VIRTIO_F_FLUSH support
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo
VIRTIO_F_BARRIER is deprecated. Replace it with VIRTIO_F_FLUSH
support.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Christoph Hellwig <hch@lst.de>
---
Documentation/lguest/lguest.c | 29 +++++++++--------------------
1 files changed, 9 insertions(+), 20 deletions(-)
diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c
index 8a6a8c6..dc73bc5 100644
--- a/Documentation/lguest/lguest.c
+++ b/Documentation/lguest/lguest.c
@@ -1640,15 +1640,6 @@ static void blk_request(struct virtqueue *vq)
off = out->sector * 512;
/*
- * The block device implements "barriers", where the Guest indicates
- * that it wants all previous writes to occur before this write. We
- * don't have a way of asking our kernel to do a barrier, so we just
- * synchronize all the data in the file. Pretty poor, no?
- */
- if (out->type & VIRTIO_BLK_T_BARRIER)
- fdatasync(vblk->fd);
-
- /*
* In general the virtio block driver is allowed to try SCSI commands.
* It'd be nice if we supported eject, for example, but we don't.
*/
@@ -1680,6 +1671,13 @@ static void blk_request(struct virtqueue *vq)
/* Die, bad Guest, die. */
errx(1, "Write past end %llu+%u", off, ret);
}
+
+ wlen = sizeof(*in);
+ *in = (ret >= 0 ? VIRTIO_BLK_S_OK : VIRTIO_BLK_S_IOERR);
+ } else if (out->type & VIRTIO_BLK_T_FLUSH) {
+ /* Flush */
+ ret = fdatasync(vblk->fd);
+ verbose("FLUSH fdatasync: %i\n", ret);
wlen = sizeof(*in);
*in = (ret >= 0 ? VIRTIO_BLK_S_OK : VIRTIO_BLK_S_IOERR);
} else {
@@ -1703,15 +1701,6 @@ static void blk_request(struct virtqueue *vq)
}
}
- /*
- * OK, so we noted that it was pretty poor to use an fdatasync as a
- * barrier. But Christoph Hellwig points out that we need a sync
- * *afterwards* as well: "Barriers specify no reordering to the front
- * or the back." And Jens Axboe confirmed it, so here we are:
- */
- if (out->type & VIRTIO_BLK_T_BARRIER)
- fdatasync(vblk->fd);
-
/* Finished that request. */
add_used(vq, head, wlen);
}
@@ -1736,8 +1725,8 @@ static void setup_block_file(const char *filename)
vblk->fd = open_or_die(filename, O_RDWR|O_LARGEFILE);
vblk->len = lseek64(vblk->fd, 0, SEEK_END);
- /* We support barriers. */
- add_feature(dev, VIRTIO_BLK_F_BARRIER);
+ /* We support FLUSH. */
+ add_feature(dev, VIRTIO_BLK_F_FLUSH);
/* Tell Guest how many sectors this device has. */
conf.capacity = cpu_to_le64(vblk->len / 512);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 21/41] md: implment REQ_FLUSH/FUA support
2010-09-03 10:29 ` Tejun Heo
` (28 preceding siblings ...)
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
This patch converts md to support REQ_FLUSH/FUA instead of now
deprecated REQ_HARDBARRIER. In the core part (md.c), the following
changes are notable.
* Unlike REQ_HARDBARRIER, REQ_FLUSH/FUA don't interfere with
processing of other requests and thus there is no reason to mark the
queue congested while FLUSH/FUA is in progress.
* REQ_FLUSH/FUA failures are final and its users don't need retry
logic. Retry logic is removed.
* Preflush needs to be issued to all member devices but FUA writes can
be handled the same way as other writes - their processing can be
deferred to request_queue of member devices. md_barrier_request()
is renamed to md_flush_request() and simplified accordingly.
For linear, raid0 and multipath, the core changes are enough. raid1,
5 and 10 need the following conversions.
* raid1: Handling of FLUSH/FUA bio's can simply be deferred to
request_queues of member devices. Barrier related logic removed.
* raid5: Queue draining logic dropped. FUA bit is propagated through
biodrain and stripe resconstruction such that all the updated parts
of the stripe are written out with FUA writes if any of the dirtying
writes was FUA. preread_active_stripes handling in make_request()
is updated as suggested by Neil Brown.
* raid10: FUA bit needs to be propagated to write clones.
linear, raid0, 1, 5 and 10 tested.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Neil Brown <neilb@suse.de>
---
drivers/md/linear.c | 4 +-
drivers/md/md.c | 117 +++++++-------------------------
drivers/md/md.h | 23 ++-----
drivers/md/multipath.c | 4 +-
drivers/md/raid0.c | 4 +-
drivers/md/raid1.c | 176 ++++++++++++++++--------------------------------
drivers/md/raid1.h | 2 -
drivers/md/raid10.c | 7 +-
drivers/md/raid5.c | 43 ++++++------
drivers/md/raid5.h | 1 +
10 files changed, 122 insertions(+), 259 deletions(-)
diff --git a/drivers/md/linear.c b/drivers/md/linear.c
index ba19060..8a2f767 100644
--- a/drivers/md/linear.c
+++ b/drivers/md/linear.c
@@ -294,8 +294,8 @@ static int linear_make_request (mddev_t *mddev, struct bio *bio)
dev_info_t *tmp_dev;
sector_t start_sector;
- if (unlikely(bio->bi_rw & REQ_HARDBARRIER)) {
- md_barrier_request(mddev, bio);
+ if (unlikely(bio->bi_rw & REQ_FLUSH)) {
+ md_flush_request(mddev, bio);
return 0;
}
diff --git a/drivers/md/md.c b/drivers/md/md.c
index c148b63..3640f02 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -226,12 +226,12 @@ static int md_make_request(struct request_queue *q, struct bio *bio)
return 0;
}
rcu_read_lock();
- if (mddev->suspended || mddev->barrier) {
+ if (mddev->suspended) {
DEFINE_WAIT(__wait);
for (;;) {
prepare_to_wait(&mddev->sb_wait, &__wait,
TASK_UNINTERRUPTIBLE);
- if (!mddev->suspended && !mddev->barrier)
+ if (!mddev->suspended)
break;
rcu_read_unlock();
schedule();
@@ -282,40 +282,29 @@ EXPORT_SYMBOL_GPL(mddev_resume);
int mddev_congested(mddev_t *mddev, int bits)
{
- if (mddev->barrier)
- return 1;
return mddev->suspended;
}
EXPORT_SYMBOL(mddev_congested);
/*
- * Generic barrier handling for md
+ * Generic flush handling for md
*/
-#define POST_REQUEST_BARRIER ((void*)1)
-
-static void md_end_barrier(struct bio *bio, int err)
+static void md_end_flush(struct bio *bio, int err)
{
mdk_rdev_t *rdev = bio->bi_private;
mddev_t *mddev = rdev->mddev;
- if (err == -EOPNOTSUPP && mddev->barrier != POST_REQUEST_BARRIER)
- set_bit(BIO_EOPNOTSUPP, &mddev->barrier->bi_flags);
rdev_dec_pending(rdev, mddev);
if (atomic_dec_and_test(&mddev->flush_pending)) {
- if (mddev->barrier == POST_REQUEST_BARRIER) {
- /* This was a post-request barrier */
- mddev->barrier = NULL;
- wake_up(&mddev->sb_wait);
- } else
- /* The pre-request barrier has finished */
- schedule_work(&mddev->barrier_work);
+ /* The pre-request flush has finished */
+ schedule_work(&mddev->flush_work);
}
bio_put(bio);
}
-static void submit_barriers(mddev_t *mddev)
+static void submit_flushes(mddev_t *mddev)
{
mdk_rdev_t *rdev;
@@ -332,60 +321,56 @@ static void submit_barriers(mddev_t *mddev)
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
bi = bio_alloc(GFP_KERNEL, 0);
- bi->bi_end_io = md_end_barrier;
+ bi->bi_end_io = md_end_flush;
bi->bi_private = rdev;
bi->bi_bdev = rdev->bdev;
atomic_inc(&mddev->flush_pending);
- submit_bio(WRITE_BARRIER, bi);
+ submit_bio(WRITE_FLUSH, bi);
rcu_read_lock();
rdev_dec_pending(rdev, mddev);
}
rcu_read_unlock();
}
-static void md_submit_barrier(struct work_struct *ws)
+static void md_submit_flush_data(struct work_struct *ws)
{
- mddev_t *mddev = container_of(ws, mddev_t, barrier_work);
- struct bio *bio = mddev->barrier;
+ mddev_t *mddev = container_of(ws, mddev_t, flush_work);
+ struct bio *bio = mddev->flush_bio;
atomic_set(&mddev->flush_pending, 1);
- if (test_bit(BIO_EOPNOTSUPP, &bio->bi_flags))
- bio_endio(bio, -EOPNOTSUPP);
- else if (bio->bi_size == 0)
+ if (bio->bi_size == 0)
/* an empty barrier - all done */
bio_endio(bio, 0);
else {
- bio->bi_rw &= ~REQ_HARDBARRIER;
+ bio->bi_rw &= ~REQ_FLUSH;
if (mddev->pers->make_request(mddev, bio))
generic_make_request(bio);
- mddev->barrier = POST_REQUEST_BARRIER;
- submit_barriers(mddev);
}
if (atomic_dec_and_test(&mddev->flush_pending)) {
- mddev->barrier = NULL;
+ mddev->flush_bio = NULL;
wake_up(&mddev->sb_wait);
}
}
-void md_barrier_request(mddev_t *mddev, struct bio *bio)
+void md_flush_request(mddev_t *mddev, struct bio *bio)
{
spin_lock_irq(&mddev->write_lock);
wait_event_lock_irq(mddev->sb_wait,
- !mddev->barrier,
+ !mddev->flush_bio,
mddev->write_lock, /*nothing*/);
- mddev->barrier = bio;
+ mddev->flush_bio = bio;
spin_unlock_irq(&mddev->write_lock);
atomic_set(&mddev->flush_pending, 1);
- INIT_WORK(&mddev->barrier_work, md_submit_barrier);
+ INIT_WORK(&mddev->flush_work, md_submit_flush_data);
- submit_barriers(mddev);
+ submit_flushes(mddev);
if (atomic_dec_and_test(&mddev->flush_pending))
- schedule_work(&mddev->barrier_work);
+ schedule_work(&mddev->flush_work);
}
-EXPORT_SYMBOL(md_barrier_request);
+EXPORT_SYMBOL(md_flush_request);
/* Support for plugging.
* This mirrors the plugging support in request_queue, but does not
@@ -696,31 +681,6 @@ static void super_written(struct bio *bio, int error)
bio_put(bio);
}
-static void super_written_barrier(struct bio *bio, int error)
-{
- struct bio *bio2 = bio->bi_private;
- mdk_rdev_t *rdev = bio2->bi_private;
- mddev_t *mddev = rdev->mddev;
-
- if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
- error == -EOPNOTSUPP) {
- unsigned long flags;
- /* barriers don't appear to be supported :-( */
- set_bit(BarriersNotsupp, &rdev->flags);
- mddev->barriers_work = 0;
- spin_lock_irqsave(&mddev->write_lock, flags);
- bio2->bi_next = mddev->biolist;
- mddev->biolist = bio2;
- spin_unlock_irqrestore(&mddev->write_lock, flags);
- wake_up(&mddev->sb_wait);
- bio_put(bio);
- } else {
- bio_put(bio2);
- bio->bi_private = rdev;
- super_written(bio, error);
- }
-}
-
void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
sector_t sector, int size, struct page *page)
{
@@ -729,51 +689,28 @@ void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
* and decrement it on completion, waking up sb_wait
* if zero is reached.
* If an error occurred, call md_error
- *
- * As we might need to resubmit the request if REQ_HARDBARRIER
- * causes ENOTSUPP, we allocate a spare bio...
*/
struct bio *bio = bio_alloc(GFP_NOIO, 1);
- int rw = REQ_WRITE | REQ_SYNC | REQ_UNPLUG;
bio->bi_bdev = rdev->bdev;
bio->bi_sector = sector;
bio_add_page(bio, page, size, 0);
bio->bi_private = rdev;
bio->bi_end_io = super_written;
- bio->bi_rw = rw;
atomic_inc(&mddev->pending_writes);
- if (!test_bit(BarriersNotsupp, &rdev->flags)) {
- struct bio *rbio;
- rw |= REQ_HARDBARRIER;
- rbio = bio_clone(bio, GFP_NOIO);
- rbio->bi_private = bio;
- rbio->bi_end_io = super_written_barrier;
- submit_bio(rw, rbio);
- } else
- submit_bio(rw, bio);
+ submit_bio(REQ_WRITE | REQ_SYNC | REQ_UNPLUG | REQ_FLUSH | REQ_FUA,
+ bio);
}
void md_super_wait(mddev_t *mddev)
{
- /* wait for all superblock writes that were scheduled to complete.
- * if any had to be retried (due to BARRIER problems), retry them
- */
+ /* wait for all superblock writes that were scheduled to complete */
DEFINE_WAIT(wq);
for(;;) {
prepare_to_wait(&mddev->sb_wait, &wq, TASK_UNINTERRUPTIBLE);
if (atomic_read(&mddev->pending_writes)==0)
break;
- while (mddev->biolist) {
- struct bio *bio;
- spin_lock_irq(&mddev->write_lock);
- bio = mddev->biolist;
- mddev->biolist = bio->bi_next ;
- bio->bi_next = NULL;
- spin_unlock_irq(&mddev->write_lock);
- submit_bio(bio->bi_rw, bio);
- }
schedule();
}
finish_wait(&mddev->sb_wait, &wq);
@@ -1070,7 +1007,6 @@ static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
clear_bit(Faulty, &rdev->flags);
clear_bit(In_sync, &rdev->flags);
clear_bit(WriteMostly, &rdev->flags);
- clear_bit(BarriersNotsupp, &rdev->flags);
if (mddev->raid_disks == 0) {
mddev->major_version = 0;
@@ -1485,7 +1421,6 @@ static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
clear_bit(Faulty, &rdev->flags);
clear_bit(In_sync, &rdev->flags);
clear_bit(WriteMostly, &rdev->flags);
- clear_bit(BarriersNotsupp, &rdev->flags);
if (mddev->raid_disks == 0) {
mddev->major_version = 1;
@@ -4506,7 +4441,6 @@ int md_run(mddev_t *mddev)
/* may be over-ridden by personality */
mddev->resync_max_sectors = mddev->dev_sectors;
- mddev->barriers_work = 1;
mddev->ok_start_degraded = start_dirty_degraded;
if (start_readonly && mddev->ro == 0)
@@ -4685,7 +4619,6 @@ static void md_clean(mddev_t *mddev)
mddev->recovery = 0;
mddev->in_sync = 0;
mddev->degraded = 0;
- mddev->barriers_work = 0;
mddev->safemode = 0;
mddev->bitmap_info.offset = 0;
mddev->bitmap_info.default_offset = 0;
diff --git a/drivers/md/md.h b/drivers/md/md.h
index a953fe2..d8e2ab2 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -87,7 +87,6 @@ struct mdk_rdev_s
#define Faulty 1 /* device is known to have a fault */
#define In_sync 2 /* device is in_sync with rest of array */
#define WriteMostly 4 /* Avoid reading if at all possible */
-#define BarriersNotsupp 5 /* REQ_HARDBARRIER is not supported */
#define AllReserved 6 /* If whole device is reserved for
* one array */
#define AutoDetected 7 /* added by auto-detect */
@@ -273,13 +272,6 @@ struct mddev_s
int degraded; /* whether md should consider
* adding a spare
*/
- int barriers_work; /* initialised to true, cleared as soon
- * as a barrier request to slave
- * fails. Only supported
- */
- struct bio *biolist; /* bios that need to be retried
- * because REQ_HARDBARRIER is not supported
- */
atomic_t recovery_active; /* blocks scheduled, but not written */
wait_queue_head_t recovery_wait;
@@ -339,16 +331,13 @@ struct mddev_s
struct attribute_group *to_remove;
struct plug_handle *plug; /* if used by personality */
- /* Generic barrier handling.
- * If there is a pending barrier request, all other
- * writes are blocked while the devices are flushed.
- * The last to finish a flush schedules a worker to
- * submit the barrier request (without the barrier flag),
- * then submit more flush requests.
+ /* Generic flush handling.
+ * The last to finish preflush schedules a worker to submit
+ * the rest of the request (without the REQ_FLUSH flag).
*/
- struct bio *barrier;
+ struct bio *flush_bio;
atomic_t flush_pending;
- struct work_struct barrier_work;
+ struct work_struct flush_work;
struct work_struct event_work; /* used by dm to report failure event */
};
@@ -502,7 +491,7 @@ extern void md_done_sync(mddev_t *mddev, int blocks, int ok);
extern void md_error(mddev_t *mddev, mdk_rdev_t *rdev);
extern int mddev_congested(mddev_t *mddev, int bits);
-extern void md_barrier_request(mddev_t *mddev, struct bio *bio);
+extern void md_flush_request(mddev_t *mddev, struct bio *bio);
extern void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
sector_t sector, int size, struct page *page);
extern void md_super_wait(mddev_t *mddev);
diff --git a/drivers/md/multipath.c b/drivers/md/multipath.c
index 0307d21..6d7ddf3 100644
--- a/drivers/md/multipath.c
+++ b/drivers/md/multipath.c
@@ -142,8 +142,8 @@ static int multipath_make_request(mddev_t *mddev, struct bio * bio)
struct multipath_bh * mp_bh;
struct multipath_info *multipath;
- if (unlikely(bio->bi_rw & REQ_HARDBARRIER)) {
- md_barrier_request(mddev, bio);
+ if (unlikely(bio->bi_rw & REQ_FLUSH)) {
+ md_flush_request(mddev, bio);
return 0;
}
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 6f7af46..a39f4c3 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -483,8 +483,8 @@ static int raid0_make_request(mddev_t *mddev, struct bio *bio)
struct strip_zone *zone;
mdk_rdev_t *tmp_dev;
- if (unlikely(bio->bi_rw & REQ_HARDBARRIER)) {
- md_barrier_request(mddev, bio);
+ if (unlikely(bio->bi_rw & REQ_FLUSH)) {
+ md_flush_request(mddev, bio);
return 0;
}
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index ad83a4d..886a9d8 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -319,83 +319,74 @@ static void raid1_end_write_request(struct bio *bio, int error)
if (r1_bio->bios[mirror] == bio)
break;
- if (error == -EOPNOTSUPP && test_bit(R1BIO_Barrier, &r1_bio->state)) {
- set_bit(BarriersNotsupp, &conf->mirrors[mirror].rdev->flags);
- set_bit(R1BIO_BarrierRetry, &r1_bio->state);
- r1_bio->mddev->barriers_work = 0;
- /* Don't rdev_dec_pending in this branch - keep it for the retry */
- } else {
+ /*
+ * 'one mirror IO has finished' event handler:
+ */
+ r1_bio->bios[mirror] = NULL;
+ to_put = bio;
+ if (!uptodate) {
+ md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
+ /* an I/O failed, we can't clear the bitmap */
+ set_bit(R1BIO_Degraded, &r1_bio->state);
+ } else
/*
- * this branch is our 'one mirror IO has finished' event handler:
+ * Set R1BIO_Uptodate in our master bio, so that we
+ * will return a good error code for to the higher
+ * levels even if IO on some other mirrored buffer
+ * fails.
+ *
+ * The 'master' represents the composite IO operation
+ * to user-side. So if something waits for IO, then it
+ * will wait for the 'master' bio.
*/
- r1_bio->bios[mirror] = NULL;
- to_put = bio;
- if (!uptodate) {
- md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
- /* an I/O failed, we can't clear the bitmap */
- set_bit(R1BIO_Degraded, &r1_bio->state);
- } else
- /*
- * Set R1BIO_Uptodate in our master bio, so that
- * we will return a good error code for to the higher
- * levels even if IO on some other mirrored buffer fails.
- *
- * The 'master' represents the composite IO operation to
- * user-side. So if something waits for IO, then it will
- * wait for the 'master' bio.
- */
- set_bit(R1BIO_Uptodate, &r1_bio->state);
-
- update_head_pos(mirror, r1_bio);
-
- if (behind) {
- if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
- atomic_dec(&r1_bio->behind_remaining);
-
- /* In behind mode, we ACK the master bio once the I/O has safely
- * reached all non-writemostly disks. Setting the Returned bit
- * ensures that this gets done only once -- we don't ever want to
- * return -EIO here, instead we'll wait */
-
- if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
- test_bit(R1BIO_Uptodate, &r1_bio->state)) {
- /* Maybe we can return now */
- if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
- struct bio *mbio = r1_bio->master_bio;
- PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n",
- (unsigned long long) mbio->bi_sector,
- (unsigned long long) mbio->bi_sector +
- (mbio->bi_size >> 9) - 1);
- bio_endio(mbio, 0);
- }
+ set_bit(R1BIO_Uptodate, &r1_bio->state);
+
+ update_head_pos(mirror, r1_bio);
+
+ if (behind) {
+ if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
+ atomic_dec(&r1_bio->behind_remaining);
+
+ /*
+ * In behind mode, we ACK the master bio once the I/O
+ * has safely reached all non-writemostly
+ * disks. Setting the Returned bit ensures that this
+ * gets done only once -- we don't ever want to return
+ * -EIO here, instead we'll wait
+ */
+ if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
+ test_bit(R1BIO_Uptodate, &r1_bio->state)) {
+ /* Maybe we can return now */
+ if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
+ struct bio *mbio = r1_bio->master_bio;
+ PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n",
+ (unsigned long long) mbio->bi_sector,
+ (unsigned long long) mbio->bi_sector +
+ (mbio->bi_size >> 9) - 1);
+ bio_endio(mbio, 0);
}
}
- rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
}
+ rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
+
/*
- *
* Let's see if all mirrored write operations have finished
* already.
*/
if (atomic_dec_and_test(&r1_bio->remaining)) {
- if (test_bit(R1BIO_BarrierRetry, &r1_bio->state))
- reschedule_retry(r1_bio);
- else {
- /* it really is the end of this request */
- if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
- /* free extra copy of the data pages */
- int i = bio->bi_vcnt;
- while (i--)
- safe_put_page(bio->bi_io_vec[i].bv_page);
- }
- /* clear the bitmap if all writes complete successfully */
- bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
- r1_bio->sectors,
- !test_bit(R1BIO_Degraded, &r1_bio->state),
- behind);
- md_write_end(r1_bio->mddev);
- raid_end_bio_io(r1_bio);
+ if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
+ /* free extra copy of the data pages */
+ int i = bio->bi_vcnt;
+ while (i--)
+ safe_put_page(bio->bi_io_vec[i].bv_page);
}
+ /* clear the bitmap if all writes complete successfully */
+ bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
+ r1_bio->sectors,
+ !test_bit(R1BIO_Degraded, &r1_bio->state),
+ behind);
+ md_write_end(r1_bio->mddev);
+ raid_end_bio_io(r1_bio);
}
if (to_put)
@@ -788,16 +779,13 @@ static int make_request(mddev_t *mddev, struct bio * bio)
struct page **behind_pages = NULL;
const int rw = bio_data_dir(bio);
const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
- unsigned long do_barriers;
+ const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
mdk_rdev_t *blocked_rdev;
/*
* Register the new request and wait if the reconstruction
* thread has put up a bar for new requests.
* Continue immediately if no resync is active currently.
- * We test barriers_work *after* md_write_start as md_write_start
- * may cause the first superblock write, and that will check out
- * if barriers work.
*/
md_write_start(mddev, bio); /* wait on superblock update early */
@@ -821,13 +809,6 @@ static int make_request(mddev_t *mddev, struct bio * bio)
}
finish_wait(&conf->wait_barrier, &w);
}
- if (unlikely(!mddev->barriers_work &&
- (bio->bi_rw & REQ_HARDBARRIER))) {
- if (rw == WRITE)
- md_write_end(mddev);
- bio_endio(bio, -EOPNOTSUPP);
- return 0;
- }
wait_barrier(conf);
@@ -959,10 +940,6 @@ static int make_request(mddev_t *mddev, struct bio * bio)
atomic_set(&r1_bio->remaining, 0);
atomic_set(&r1_bio->behind_remaining, 0);
- do_barriers = bio->bi_rw & REQ_HARDBARRIER;
- if (do_barriers)
- set_bit(R1BIO_Barrier, &r1_bio->state);
-
bio_list_init(&bl);
for (i = 0; i < disks; i++) {
struct bio *mbio;
@@ -975,7 +952,7 @@ static int make_request(mddev_t *mddev, struct bio * bio)
mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset;
mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
mbio->bi_end_io = raid1_end_write_request;
- mbio->bi_rw = WRITE | do_barriers | do_sync;
+ mbio->bi_rw = WRITE | do_flush_fua | do_sync;
mbio->bi_private = r1_bio;
if (behind_pages) {
@@ -1634,41 +1611,6 @@ static void raid1d(mddev_t *mddev)
if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
sync_request_write(mddev, r1_bio);
unplug = 1;
- } else if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) {
- /* some requests in the r1bio were REQ_HARDBARRIER
- * requests which failed with -EOPNOTSUPP. Hohumm..
- * Better resubmit without the barrier.
- * We know which devices to resubmit for, because
- * all others have had their bios[] entry cleared.
- * We already have a nr_pending reference on these rdevs.
- */
- int i;
- const unsigned long do_sync = (r1_bio->master_bio->bi_rw & REQ_SYNC);
- clear_bit(R1BIO_BarrierRetry, &r1_bio->state);
- clear_bit(R1BIO_Barrier, &r1_bio->state);
- for (i=0; i < conf->raid_disks; i++)
- if (r1_bio->bios[i])
- atomic_inc(&r1_bio->remaining);
- for (i=0; i < conf->raid_disks; i++)
- if (r1_bio->bios[i]) {
- struct bio_vec *bvec;
- int j;
-
- bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
- /* copy pages from the failed bio, as
- * this might be a write-behind device */
- __bio_for_each_segment(bvec, bio, j, 0)
- bvec->bv_page = bio_iovec_idx(r1_bio->bios[i], j)->bv_page;
- bio_put(r1_bio->bios[i]);
- bio->bi_sector = r1_bio->sector +
- conf->mirrors[i].rdev->data_offset;
- bio->bi_bdev = conf->mirrors[i].rdev->bdev;
- bio->bi_end_io = raid1_end_write_request;
- bio->bi_rw = WRITE | do_sync;
- bio->bi_private = r1_bio;
- r1_bio->bios[i] = bio;
- generic_make_request(bio);
- }
} else {
int disk;
diff --git a/drivers/md/raid1.h b/drivers/md/raid1.h
index 5f2d443..adf8cfd 100644
--- a/drivers/md/raid1.h
+++ b/drivers/md/raid1.h
@@ -117,8 +117,6 @@ struct r1bio_s {
#define R1BIO_IsSync 1
#define R1BIO_Degraded 2
#define R1BIO_BehindIO 3
-#define R1BIO_Barrier 4
-#define R1BIO_BarrierRetry 5
/* For write-behind requests, we call bi_end_io when
* the last non-write-behind device completes, providing
* any write was successful. Otherwise we call when
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 8471838..f0d082f 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -800,12 +800,13 @@ static int make_request(mddev_t *mddev, struct bio * bio)
int chunk_sects = conf->chunk_mask + 1;
const int rw = bio_data_dir(bio);
const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
+ const unsigned long do_fua = (bio->bi_rw & REQ_FUA);
struct bio_list bl;
unsigned long flags;
mdk_rdev_t *blocked_rdev;
- if (unlikely(bio->bi_rw & REQ_HARDBARRIER)) {
- md_barrier_request(mddev, bio);
+ if (unlikely(bio->bi_rw & REQ_FLUSH)) {
+ md_flush_request(mddev, bio);
return 0;
}
@@ -965,7 +966,7 @@ static int make_request(mddev_t *mddev, struct bio * bio)
conf->mirrors[d].rdev->data_offset;
mbio->bi_bdev = conf->mirrors[d].rdev->bdev;
mbio->bi_end_io = raid10_end_write_request;
- mbio->bi_rw = WRITE | do_sync;
+ mbio->bi_rw = WRITE | do_sync | do_fua;
mbio->bi_private = r10_bio;
atomic_inc(&r10_bio->remaining);
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 69b0a16..31140d1 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -506,9 +506,12 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
int rw;
struct bio *bi;
mdk_rdev_t *rdev;
- if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags))
- rw = WRITE;
- else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
+ if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) {
+ if (test_and_clear_bit(R5_WantFUA, &sh->dev[i].flags))
+ rw = WRITE_FUA;
+ else
+ rw = WRITE;
+ } else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
rw = READ;
else
continue;
@@ -1031,6 +1034,8 @@ ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
while (wbi && wbi->bi_sector <
dev->sector + STRIPE_SECTORS) {
+ if (wbi->bi_rw & REQ_FUA)
+ set_bit(R5_WantFUA, &dev->flags);
tx = async_copy_data(1, wbi, dev->page,
dev->sector, tx);
wbi = r5_next_bio(wbi, dev->sector);
@@ -1048,15 +1053,22 @@ static void ops_complete_reconstruct(void *stripe_head_ref)
int pd_idx = sh->pd_idx;
int qd_idx = sh->qd_idx;
int i;
+ bool fua = false;
pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
+ for (i = disks; i--; )
+ fua |= test_bit(R5_WantFUA, &sh->dev[i].flags);
+
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
- if (dev->written || i == pd_idx || i == qd_idx)
+ if (dev->written || i == pd_idx || i == qd_idx) {
set_bit(R5_UPTODATE, &dev->flags);
+ if (fua)
+ set_bit(R5_WantFUA, &dev->flags);
+ }
}
if (sh->reconstruct_state == reconstruct_state_drain_run)
@@ -3281,7 +3293,7 @@ static void handle_stripe5(struct stripe_head *sh)
if (dec_preread_active) {
/* We delay this until after ops_run_io so that if make_request
- * is waiting on a barrier, it won't continue until the writes
+ * is waiting on a flush, it won't continue until the writes
* have actually been submitted.
*/
atomic_dec(&conf->preread_active_stripes);
@@ -3583,7 +3595,7 @@ static void handle_stripe6(struct stripe_head *sh)
if (dec_preread_active) {
/* We delay this until after ops_run_io so that if make_request
- * is waiting on a barrier, it won't continue until the writes
+ * is waiting on a flush, it won't continue until the writes
* have actually been submitted.
*/
atomic_dec(&conf->preread_active_stripes);
@@ -3978,14 +3990,8 @@ static int make_request(mddev_t *mddev, struct bio * bi)
const int rw = bio_data_dir(bi);
int remaining;
- if (unlikely(bi->bi_rw & REQ_HARDBARRIER)) {
- /* Drain all pending writes. We only really need
- * to ensure they have been submitted, but this is
- * easier.
- */
- mddev->pers->quiesce(mddev, 1);
- mddev->pers->quiesce(mddev, 0);
- md_barrier_request(mddev, bi);
+ if (unlikely(bi->bi_rw & REQ_FLUSH)) {
+ md_flush_request(mddev, bi);
return 0;
}
@@ -4103,7 +4109,7 @@ static int make_request(mddev_t *mddev, struct bio * bi)
finish_wait(&conf->wait_for_overlap, &w);
set_bit(STRIPE_HANDLE, &sh->state);
clear_bit(STRIPE_DELAYED, &sh->state);
- if (mddev->barrier &&
+ if ((bi->bi_rw & REQ_SYNC) &&
!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
atomic_inc(&conf->preread_active_stripes);
release_stripe(sh);
@@ -4126,13 +4132,6 @@ static int make_request(mddev_t *mddev, struct bio * bi)
bio_endio(bi, 0);
}
- if (mddev->barrier) {
- /* We need to wait for the stripes to all be handled.
- * So: wait for preread_active_stripes to drop to 0.
- */
- wait_event(mddev->thread->wqueue,
- atomic_read(&conf->preread_active_stripes) == 0);
- }
return 0;
}
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index 36eaed5..2ace058 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -275,6 +275,7 @@ struct r6_state {
* filling
*/
#define R5_Wantdrain 13 /* dev->towrite needs to be drained */
+#define R5_WantFUA 14 /* Write should be FUA */
/*
* Write method
*/
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 21/41] md: implment REQ_FLUSH/FUA support
2010-09-03 10:29 ` Tejun Heo
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel
Cc: Tejun Heo
This patch converts md to support REQ_FLUSH/FUA instead of now
deprecated REQ_HARDBARRIER. In the core part (md.c), the following
changes are notable.
* Unlike REQ_HARDBARRIER, REQ_FLUSH/FUA don't interfere with
processing of other requests and thus there is no reason to mark the
queue congested while FLUSH/FUA is in progress.
* REQ_FLUSH/FUA failures are final and its users don't need retry
logic. Retry logic is removed.
* Preflush needs to be issued to all member devices but FUA writes can
be handled the same way as other writes - their processing can be
deferred to request_queue of member devices. md_barrier_request()
is renamed to md_flush_request() and simplified accordingly.
For linear, raid0 and multipath, the core changes are enough. raid1,
5 and 10 need the following conversions.
* raid1: Handling of FLUSH/FUA bio's can simply be deferred to
request_queues of member devices. Barrier related logic removed.
* raid5: Queue draining logic dropped. FUA bit is propagated through
biodrain and stripe resconstruction such that all the updated parts
of the stripe are written out with FUA writes if any of the dirtying
writes was FUA. preread_active_stripes handling in make_request()
is updated as suggested by Neil Brown.
* raid10: FUA bit needs to be propagated to write clones.
linear, raid0, 1, 5 and 10 tested.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Neil Brown <neilb@suse.de>
---
drivers/md/linear.c | 4 +-
drivers/md/md.c | 117 +++++++-------------------------
drivers/md/md.h | 23 ++-----
drivers/md/multipath.c | 4 +-
drivers/md/raid0.c | 4 +-
drivers/md/raid1.c | 176 ++++++++++++++++--------------------------------
drivers/md/raid1.h | 2 -
drivers/md/raid10.c | 7 +-
drivers/md/raid5.c | 43 ++++++------
drivers/md/raid5.h | 1 +
10 files changed, 122 insertions(+), 259 deletions(-)
diff --git a/drivers/md/linear.c b/drivers/md/linear.c
index ba19060..8a2f767 100644
--- a/drivers/md/linear.c
+++ b/drivers/md/linear.c
@@ -294,8 +294,8 @@ static int linear_make_request (mddev_t *mddev, struct bio *bio)
dev_info_t *tmp_dev;
sector_t start_sector;
- if (unlikely(bio->bi_rw & REQ_HARDBARRIER)) {
- md_barrier_request(mddev, bio);
+ if (unlikely(bio->bi_rw & REQ_FLUSH)) {
+ md_flush_request(mddev, bio);
return 0;
}
diff --git a/drivers/md/md.c b/drivers/md/md.c
index c148b63..3640f02 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -226,12 +226,12 @@ static int md_make_request(struct request_queue *q, struct bio *bio)
return 0;
}
rcu_read_lock();
- if (mddev->suspended || mddev->barrier) {
+ if (mddev->suspended) {
DEFINE_WAIT(__wait);
for (;;) {
prepare_to_wait(&mddev->sb_wait, &__wait,
TASK_UNINTERRUPTIBLE);
- if (!mddev->suspended && !mddev->barrier)
+ if (!mddev->suspended)
break;
rcu_read_unlock();
schedule();
@@ -282,40 +282,29 @@ EXPORT_SYMBOL_GPL(mddev_resume);
int mddev_congested(mddev_t *mddev, int bits)
{
- if (mddev->barrier)
- return 1;
return mddev->suspended;
}
EXPORT_SYMBOL(mddev_congested);
/*
- * Generic barrier handling for md
+ * Generic flush handling for md
*/
-#define POST_REQUEST_BARRIER ((void*)1)
-
-static void md_end_barrier(struct bio *bio, int err)
+static void md_end_flush(struct bio *bio, int err)
{
mdk_rdev_t *rdev = bio->bi_private;
mddev_t *mddev = rdev->mddev;
- if (err == -EOPNOTSUPP && mddev->barrier != POST_REQUEST_BARRIER)
- set_bit(BIO_EOPNOTSUPP, &mddev->barrier->bi_flags);
rdev_dec_pending(rdev, mddev);
if (atomic_dec_and_test(&mddev->flush_pending)) {
- if (mddev->barrier == POST_REQUEST_BARRIER) {
- /* This was a post-request barrier */
- mddev->barrier = NULL;
- wake_up(&mddev->sb_wait);
- } else
- /* The pre-request barrier has finished */
- schedule_work(&mddev->barrier_work);
+ /* The pre-request flush has finished */
+ schedule_work(&mddev->flush_work);
}
bio_put(bio);
}
-static void submit_barriers(mddev_t *mddev)
+static void submit_flushes(mddev_t *mddev)
{
mdk_rdev_t *rdev;
@@ -332,60 +321,56 @@ static void submit_barriers(mddev_t *mddev)
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
bi = bio_alloc(GFP_KERNEL, 0);
- bi->bi_end_io = md_end_barrier;
+ bi->bi_end_io = md_end_flush;
bi->bi_private = rdev;
bi->bi_bdev = rdev->bdev;
atomic_inc(&mddev->flush_pending);
- submit_bio(WRITE_BARRIER, bi);
+ submit_bio(WRITE_FLUSH, bi);
rcu_read_lock();
rdev_dec_pending(rdev, mddev);
}
rcu_read_unlock();
}
-static void md_submit_barrier(struct work_struct *ws)
+static void md_submit_flush_data(struct work_struct *ws)
{
- mddev_t *mddev = container_of(ws, mddev_t, barrier_work);
- struct bio *bio = mddev->barrier;
+ mddev_t *mddev = container_of(ws, mddev_t, flush_work);
+ struct bio *bio = mddev->flush_bio;
atomic_set(&mddev->flush_pending, 1);
- if (test_bit(BIO_EOPNOTSUPP, &bio->bi_flags))
- bio_endio(bio, -EOPNOTSUPP);
- else if (bio->bi_size == 0)
+ if (bio->bi_size == 0)
/* an empty barrier - all done */
bio_endio(bio, 0);
else {
- bio->bi_rw &= ~REQ_HARDBARRIER;
+ bio->bi_rw &= ~REQ_FLUSH;
if (mddev->pers->make_request(mddev, bio))
generic_make_request(bio);
- mddev->barrier = POST_REQUEST_BARRIER;
- submit_barriers(mddev);
}
if (atomic_dec_and_test(&mddev->flush_pending)) {
- mddev->barrier = NULL;
+ mddev->flush_bio = NULL;
wake_up(&mddev->sb_wait);
}
}
-void md_barrier_request(mddev_t *mddev, struct bio *bio)
+void md_flush_request(mddev_t *mddev, struct bio *bio)
{
spin_lock_irq(&mddev->write_lock);
wait_event_lock_irq(mddev->sb_wait,
- !mddev->barrier,
+ !mddev->flush_bio,
mddev->write_lock, /*nothing*/);
- mddev->barrier = bio;
+ mddev->flush_bio = bio;
spin_unlock_irq(&mddev->write_lock);
atomic_set(&mddev->flush_pending, 1);
- INIT_WORK(&mddev->barrier_work, md_submit_barrier);
+ INIT_WORK(&mddev->flush_work, md_submit_flush_data);
- submit_barriers(mddev);
+ submit_flushes(mddev);
if (atomic_dec_and_test(&mddev->flush_pending))
- schedule_work(&mddev->barrier_work);
+ schedule_work(&mddev->flush_work);
}
-EXPORT_SYMBOL(md_barrier_request);
+EXPORT_SYMBOL(md_flush_request);
/* Support for plugging.
* This mirrors the plugging support in request_queue, but does not
@@ -696,31 +681,6 @@ static void super_written(struct bio *bio, int error)
bio_put(bio);
}
-static void super_written_barrier(struct bio *bio, int error)
-{
- struct bio *bio2 = bio->bi_private;
- mdk_rdev_t *rdev = bio2->bi_private;
- mddev_t *mddev = rdev->mddev;
-
- if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
- error == -EOPNOTSUPP) {
- unsigned long flags;
- /* barriers don't appear to be supported :-( */
- set_bit(BarriersNotsupp, &rdev->flags);
- mddev->barriers_work = 0;
- spin_lock_irqsave(&mddev->write_lock, flags);
- bio2->bi_next = mddev->biolist;
- mddev->biolist = bio2;
- spin_unlock_irqrestore(&mddev->write_lock, flags);
- wake_up(&mddev->sb_wait);
- bio_put(bio);
- } else {
- bio_put(bio2);
- bio->bi_private = rdev;
- super_written(bio, error);
- }
-}
-
void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
sector_t sector, int size, struct page *page)
{
@@ -729,51 +689,28 @@ void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
* and decrement it on completion, waking up sb_wait
* if zero is reached.
* If an error occurred, call md_error
- *
- * As we might need to resubmit the request if REQ_HARDBARRIER
- * causes ENOTSUPP, we allocate a spare bio...
*/
struct bio *bio = bio_alloc(GFP_NOIO, 1);
- int rw = REQ_WRITE | REQ_SYNC | REQ_UNPLUG;
bio->bi_bdev = rdev->bdev;
bio->bi_sector = sector;
bio_add_page(bio, page, size, 0);
bio->bi_private = rdev;
bio->bi_end_io = super_written;
- bio->bi_rw = rw;
atomic_inc(&mddev->pending_writes);
- if (!test_bit(BarriersNotsupp, &rdev->flags)) {
- struct bio *rbio;
- rw |= REQ_HARDBARRIER;
- rbio = bio_clone(bio, GFP_NOIO);
- rbio->bi_private = bio;
- rbio->bi_end_io = super_written_barrier;
- submit_bio(rw, rbio);
- } else
- submit_bio(rw, bio);
+ submit_bio(REQ_WRITE | REQ_SYNC | REQ_UNPLUG | REQ_FLUSH | REQ_FUA,
+ bio);
}
void md_super_wait(mddev_t *mddev)
{
- /* wait for all superblock writes that were scheduled to complete.
- * if any had to be retried (due to BARRIER problems), retry them
- */
+ /* wait for all superblock writes that were scheduled to complete */
DEFINE_WAIT(wq);
for(;;) {
prepare_to_wait(&mddev->sb_wait, &wq, TASK_UNINTERRUPTIBLE);
if (atomic_read(&mddev->pending_writes)==0)
break;
- while (mddev->biolist) {
- struct bio *bio;
- spin_lock_irq(&mddev->write_lock);
- bio = mddev->biolist;
- mddev->biolist = bio->bi_next ;
- bio->bi_next = NULL;
- spin_unlock_irq(&mddev->write_lock);
- submit_bio(bio->bi_rw, bio);
- }
schedule();
}
finish_wait(&mddev->sb_wait, &wq);
@@ -1070,7 +1007,6 @@ static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
clear_bit(Faulty, &rdev->flags);
clear_bit(In_sync, &rdev->flags);
clear_bit(WriteMostly, &rdev->flags);
- clear_bit(BarriersNotsupp, &rdev->flags);
if (mddev->raid_disks == 0) {
mddev->major_version = 0;
@@ -1485,7 +1421,6 @@ static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
clear_bit(Faulty, &rdev->flags);
clear_bit(In_sync, &rdev->flags);
clear_bit(WriteMostly, &rdev->flags);
- clear_bit(BarriersNotsupp, &rdev->flags);
if (mddev->raid_disks == 0) {
mddev->major_version = 1;
@@ -4506,7 +4441,6 @@ int md_run(mddev_t *mddev)
/* may be over-ridden by personality */
mddev->resync_max_sectors = mddev->dev_sectors;
- mddev->barriers_work = 1;
mddev->ok_start_degraded = start_dirty_degraded;
if (start_readonly && mddev->ro == 0)
@@ -4685,7 +4619,6 @@ static void md_clean(mddev_t *mddev)
mddev->recovery = 0;
mddev->in_sync = 0;
mddev->degraded = 0;
- mddev->barriers_work = 0;
mddev->safemode = 0;
mddev->bitmap_info.offset = 0;
mddev->bitmap_info.default_offset = 0;
diff --git a/drivers/md/md.h b/drivers/md/md.h
index a953fe2..d8e2ab2 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -87,7 +87,6 @@ struct mdk_rdev_s
#define Faulty 1 /* device is known to have a fault */
#define In_sync 2 /* device is in_sync with rest of array */
#define WriteMostly 4 /* Avoid reading if at all possible */
-#define BarriersNotsupp 5 /* REQ_HARDBARRIER is not supported */
#define AllReserved 6 /* If whole device is reserved for
* one array */
#define AutoDetected 7 /* added by auto-detect */
@@ -273,13 +272,6 @@ struct mddev_s
int degraded; /* whether md should consider
* adding a spare
*/
- int barriers_work; /* initialised to true, cleared as soon
- * as a barrier request to slave
- * fails. Only supported
- */
- struct bio *biolist; /* bios that need to be retried
- * because REQ_HARDBARRIER is not supported
- */
atomic_t recovery_active; /* blocks scheduled, but not written */
wait_queue_head_t recovery_wait;
@@ -339,16 +331,13 @@ struct mddev_s
struct attribute_group *to_remove;
struct plug_handle *plug; /* if used by personality */
- /* Generic barrier handling.
- * If there is a pending barrier request, all other
- * writes are blocked while the devices are flushed.
- * The last to finish a flush schedules a worker to
- * submit the barrier request (without the barrier flag),
- * then submit more flush requests.
+ /* Generic flush handling.
+ * The last to finish preflush schedules a worker to submit
+ * the rest of the request (without the REQ_FLUSH flag).
*/
- struct bio *barrier;
+ struct bio *flush_bio;
atomic_t flush_pending;
- struct work_struct barrier_work;
+ struct work_struct flush_work;
struct work_struct event_work; /* used by dm to report failure event */
};
@@ -502,7 +491,7 @@ extern void md_done_sync(mddev_t *mddev, int blocks, int ok);
extern void md_error(mddev_t *mddev, mdk_rdev_t *rdev);
extern int mddev_congested(mddev_t *mddev, int bits);
-extern void md_barrier_request(mddev_t *mddev, struct bio *bio);
+extern void md_flush_request(mddev_t *mddev, struct bio *bio);
extern void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
sector_t sector, int size, struct page *page);
extern void md_super_wait(mddev_t *mddev);
diff --git a/drivers/md/multipath.c b/drivers/md/multipath.c
index 0307d21..6d7ddf3 100644
--- a/drivers/md/multipath.c
+++ b/drivers/md/multipath.c
@@ -142,8 +142,8 @@ static int multipath_make_request(mddev_t *mddev, struct bio * bio)
struct multipath_bh * mp_bh;
struct multipath_info *multipath;
- if (unlikely(bio->bi_rw & REQ_HARDBARRIER)) {
- md_barrier_request(mddev, bio);
+ if (unlikely(bio->bi_rw & REQ_FLUSH)) {
+ md_flush_request(mddev, bio);
return 0;
}
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 6f7af46..a39f4c3 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -483,8 +483,8 @@ static int raid0_make_request(mddev_t *mddev, struct bio *bio)
struct strip_zone *zone;
mdk_rdev_t *tmp_dev;
- if (unlikely(bio->bi_rw & REQ_HARDBARRIER)) {
- md_barrier_request(mddev, bio);
+ if (unlikely(bio->bi_rw & REQ_FLUSH)) {
+ md_flush_request(mddev, bio);
return 0;
}
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index ad83a4d..886a9d8 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -319,83 +319,74 @@ static void raid1_end_write_request(struct bio *bio, int error)
if (r1_bio->bios[mirror] == bio)
break;
- if (error == -EOPNOTSUPP && test_bit(R1BIO_Barrier, &r1_bio->state)) {
- set_bit(BarriersNotsupp, &conf->mirrors[mirror].rdev->flags);
- set_bit(R1BIO_BarrierRetry, &r1_bio->state);
- r1_bio->mddev->barriers_work = 0;
- /* Don't rdev_dec_pending in this branch - keep it for the retry */
- } else {
+ /*
+ * 'one mirror IO has finished' event handler:
+ */
+ r1_bio->bios[mirror] = NULL;
+ to_put = bio;
+ if (!uptodate) {
+ md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
+ /* an I/O failed, we can't clear the bitmap */
+ set_bit(R1BIO_Degraded, &r1_bio->state);
+ } else
/*
- * this branch is our 'one mirror IO has finished' event handler:
+ * Set R1BIO_Uptodate in our master bio, so that we
+ * will return a good error code for to the higher
+ * levels even if IO on some other mirrored buffer
+ * fails.
+ *
+ * The 'master' represents the composite IO operation
+ * to user-side. So if something waits for IO, then it
+ * will wait for the 'master' bio.
*/
- r1_bio->bios[mirror] = NULL;
- to_put = bio;
- if (!uptodate) {
- md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
- /* an I/O failed, we can't clear the bitmap */
- set_bit(R1BIO_Degraded, &r1_bio->state);
- } else
- /*
- * Set R1BIO_Uptodate in our master bio, so that
- * we will return a good error code for to the higher
- * levels even if IO on some other mirrored buffer fails.
- *
- * The 'master' represents the composite IO operation to
- * user-side. So if something waits for IO, then it will
- * wait for the 'master' bio.
- */
- set_bit(R1BIO_Uptodate, &r1_bio->state);
-
- update_head_pos(mirror, r1_bio);
-
- if (behind) {
- if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
- atomic_dec(&r1_bio->behind_remaining);
-
- /* In behind mode, we ACK the master bio once the I/O has safely
- * reached all non-writemostly disks. Setting the Returned bit
- * ensures that this gets done only once -- we don't ever want to
- * return -EIO here, instead we'll wait */
-
- if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
- test_bit(R1BIO_Uptodate, &r1_bio->state)) {
- /* Maybe we can return now */
- if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
- struct bio *mbio = r1_bio->master_bio;
- PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n",
- (unsigned long long) mbio->bi_sector,
- (unsigned long long) mbio->bi_sector +
- (mbio->bi_size >> 9) - 1);
- bio_endio(mbio, 0);
- }
+ set_bit(R1BIO_Uptodate, &r1_bio->state);
+
+ update_head_pos(mirror, r1_bio);
+
+ if (behind) {
+ if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
+ atomic_dec(&r1_bio->behind_remaining);
+
+ /*
+ * In behind mode, we ACK the master bio once the I/O
+ * has safely reached all non-writemostly
+ * disks. Setting the Returned bit ensures that this
+ * gets done only once -- we don't ever want to return
+ * -EIO here, instead we'll wait
+ */
+ if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
+ test_bit(R1BIO_Uptodate, &r1_bio->state)) {
+ /* Maybe we can return now */
+ if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
+ struct bio *mbio = r1_bio->master_bio;
+ PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n",
+ (unsigned long long) mbio->bi_sector,
+ (unsigned long long) mbio->bi_sector +
+ (mbio->bi_size >> 9) - 1);
+ bio_endio(mbio, 0);
}
}
- rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
}
+ rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
+
/*
- *
* Let's see if all mirrored write operations have finished
* already.
*/
if (atomic_dec_and_test(&r1_bio->remaining)) {
- if (test_bit(R1BIO_BarrierRetry, &r1_bio->state))
- reschedule_retry(r1_bio);
- else {
- /* it really is the end of this request */
- if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
- /* free extra copy of the data pages */
- int i = bio->bi_vcnt;
- while (i--)
- safe_put_page(bio->bi_io_vec[i].bv_page);
- }
- /* clear the bitmap if all writes complete successfully */
- bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
- r1_bio->sectors,
- !test_bit(R1BIO_Degraded, &r1_bio->state),
- behind);
- md_write_end(r1_bio->mddev);
- raid_end_bio_io(r1_bio);
+ if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
+ /* free extra copy of the data pages */
+ int i = bio->bi_vcnt;
+ while (i--)
+ safe_put_page(bio->bi_io_vec[i].bv_page);
}
+ /* clear the bitmap if all writes complete successfully */
+ bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
+ r1_bio->sectors,
+ !test_bit(R1BIO_Degraded, &r1_bio->state),
+ behind);
+ md_write_end(r1_bio->mddev);
+ raid_end_bio_io(r1_bio);
}
if (to_put)
@@ -788,16 +779,13 @@ static int make_request(mddev_t *mddev, struct bio * bio)
struct page **behind_pages = NULL;
const int rw = bio_data_dir(bio);
const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
- unsigned long do_barriers;
+ const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
mdk_rdev_t *blocked_rdev;
/*
* Register the new request and wait if the reconstruction
* thread has put up a bar for new requests.
* Continue immediately if no resync is active currently.
- * We test barriers_work *after* md_write_start as md_write_start
- * may cause the first superblock write, and that will check out
- * if barriers work.
*/
md_write_start(mddev, bio); /* wait on superblock update early */
@@ -821,13 +809,6 @@ static int make_request(mddev_t *mddev, struct bio * bio)
}
finish_wait(&conf->wait_barrier, &w);
}
- if (unlikely(!mddev->barriers_work &&
- (bio->bi_rw & REQ_HARDBARRIER))) {
- if (rw == WRITE)
- md_write_end(mddev);
- bio_endio(bio, -EOPNOTSUPP);
- return 0;
- }
wait_barrier(conf);
@@ -959,10 +940,6 @@ static int make_request(mddev_t *mddev, struct bio * bio)
atomic_set(&r1_bio->remaining, 0);
atomic_set(&r1_bio->behind_remaining, 0);
- do_barriers = bio->bi_rw & REQ_HARDBARRIER;
- if (do_barriers)
- set_bit(R1BIO_Barrier, &r1_bio->state);
-
bio_list_init(&bl);
for (i = 0; i < disks; i++) {
struct bio *mbio;
@@ -975,7 +952,7 @@ static int make_request(mddev_t *mddev, struct bio * bio)
mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset;
mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
mbio->bi_end_io = raid1_end_write_request;
- mbio->bi_rw = WRITE | do_barriers | do_sync;
+ mbio->bi_rw = WRITE | do_flush_fua | do_sync;
mbio->bi_private = r1_bio;
if (behind_pages) {
@@ -1634,41 +1611,6 @@ static void raid1d(mddev_t *mddev)
if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
sync_request_write(mddev, r1_bio);
unplug = 1;
- } else if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) {
- /* some requests in the r1bio were REQ_HARDBARRIER
- * requests which failed with -EOPNOTSUPP. Hohumm..
- * Better resubmit without the barrier.
- * We know which devices to resubmit for, because
- * all others have had their bios[] entry cleared.
- * We already have a nr_pending reference on these rdevs.
- */
- int i;
- const unsigned long do_sync = (r1_bio->master_bio->bi_rw & REQ_SYNC);
- clear_bit(R1BIO_BarrierRetry, &r1_bio->state);
- clear_bit(R1BIO_Barrier, &r1_bio->state);
- for (i=0; i < conf->raid_disks; i++)
- if (r1_bio->bios[i])
- atomic_inc(&r1_bio->remaining);
- for (i=0; i < conf->raid_disks; i++)
- if (r1_bio->bios[i]) {
- struct bio_vec *bvec;
- int j;
-
- bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
- /* copy pages from the failed bio, as
- * this might be a write-behind device */
- __bio_for_each_segment(bvec, bio, j, 0)
- bvec->bv_page = bio_iovec_idx(r1_bio->bios[i], j)->bv_page;
- bio_put(r1_bio->bios[i]);
- bio->bi_sector = r1_bio->sector +
- conf->mirrors[i].rdev->data_offset;
- bio->bi_bdev = conf->mirrors[i].rdev->bdev;
- bio->bi_end_io = raid1_end_write_request;
- bio->bi_rw = WRITE | do_sync;
- bio->bi_private = r1_bio;
- r1_bio->bios[i] = bio;
- generic_make_request(bio);
- }
} else {
int disk;
diff --git a/drivers/md/raid1.h b/drivers/md/raid1.h
index 5f2d443..adf8cfd 100644
--- a/drivers/md/raid1.h
+++ b/drivers/md/raid1.h
@@ -117,8 +117,6 @@ struct r1bio_s {
#define R1BIO_IsSync 1
#define R1BIO_Degraded 2
#define R1BIO_BehindIO 3
-#define R1BIO_Barrier 4
-#define R1BIO_BarrierRetry 5
/* For write-behind requests, we call bi_end_io when
* the last non-write-behind device completes, providing
* any write was successful. Otherwise we call when
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 8471838..f0d082f 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -800,12 +800,13 @@ static int make_request(mddev_t *mddev, struct bio * bio)
int chunk_sects = conf->chunk_mask + 1;
const int rw = bio_data_dir(bio);
const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
+ const unsigned long do_fua = (bio->bi_rw & REQ_FUA);
struct bio_list bl;
unsigned long flags;
mdk_rdev_t *blocked_rdev;
- if (unlikely(bio->bi_rw & REQ_HARDBARRIER)) {
- md_barrier_request(mddev, bio);
+ if (unlikely(bio->bi_rw & REQ_FLUSH)) {
+ md_flush_request(mddev, bio);
return 0;
}
@@ -965,7 +966,7 @@ static int make_request(mddev_t *mddev, struct bio * bio)
conf->mirrors[d].rdev->data_offset;
mbio->bi_bdev = conf->mirrors[d].rdev->bdev;
mbio->bi_end_io = raid10_end_write_request;
- mbio->bi_rw = WRITE | do_sync;
+ mbio->bi_rw = WRITE | do_sync | do_fua;
mbio->bi_private = r10_bio;
atomic_inc(&r10_bio->remaining);
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 69b0a16..31140d1 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -506,9 +506,12 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
int rw;
struct bio *bi;
mdk_rdev_t *rdev;
- if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags))
- rw = WRITE;
- else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
+ if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) {
+ if (test_and_clear_bit(R5_WantFUA, &sh->dev[i].flags))
+ rw = WRITE_FUA;
+ else
+ rw = WRITE;
+ } else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
rw = READ;
else
continue;
@@ -1031,6 +1034,8 @@ ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
while (wbi && wbi->bi_sector <
dev->sector + STRIPE_SECTORS) {
+ if (wbi->bi_rw & REQ_FUA)
+ set_bit(R5_WantFUA, &dev->flags);
tx = async_copy_data(1, wbi, dev->page,
dev->sector, tx);
wbi = r5_next_bio(wbi, dev->sector);
@@ -1048,15 +1053,22 @@ static void ops_complete_reconstruct(void *stripe_head_ref)
int pd_idx = sh->pd_idx;
int qd_idx = sh->qd_idx;
int i;
+ bool fua = false;
pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
+ for (i = disks; i--; )
+ fua |= test_bit(R5_WantFUA, &sh->dev[i].flags);
+
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
- if (dev->written || i == pd_idx || i == qd_idx)
+ if (dev->written || i == pd_idx || i == qd_idx) {
set_bit(R5_UPTODATE, &dev->flags);
+ if (fua)
+ set_bit(R5_WantFUA, &dev->flags);
+ }
}
if (sh->reconstruct_state == reconstruct_state_drain_run)
@@ -3281,7 +3293,7 @@ static void handle_stripe5(struct stripe_head *sh)
if (dec_preread_active) {
/* We delay this until after ops_run_io so that if make_request
- * is waiting on a barrier, it won't continue until the writes
+ * is waiting on a flush, it won't continue until the writes
* have actually been submitted.
*/
atomic_dec(&conf->preread_active_stripes);
@@ -3583,7 +3595,7 @@ static void handle_stripe6(struct stripe_head *sh)
if (dec_preread_active) {
/* We delay this until after ops_run_io so that if make_request
- * is waiting on a barrier, it won't continue until the writes
+ * is waiting on a flush, it won't continue until the writes
* have actually been submitted.
*/
atomic_dec(&conf->preread_active_stripes);
@@ -3978,14 +3990,8 @@ static int make_request(mddev_t *mddev, struct bio * bi)
const int rw = bio_data_dir(bi);
int remaining;
- if (unlikely(bi->bi_rw & REQ_HARDBARRIER)) {
- /* Drain all pending writes. We only really need
- * to ensure they have been submitted, but this is
- * easier.
- */
- mddev->pers->quiesce(mddev, 1);
- mddev->pers->quiesce(mddev, 0);
- md_barrier_request(mddev, bi);
+ if (unlikely(bi->bi_rw & REQ_FLUSH)) {
+ md_flush_request(mddev, bi);
return 0;
}
@@ -4103,7 +4109,7 @@ static int make_request(mddev_t *mddev, struct bio * bi)
finish_wait(&conf->wait_for_overlap, &w);
set_bit(STRIPE_HANDLE, &sh->state);
clear_bit(STRIPE_DELAYED, &sh->state);
- if (mddev->barrier &&
+ if ((bi->bi_rw & REQ_SYNC) &&
!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
atomic_inc(&conf->preread_active_stripes);
release_stripe(sh);
@@ -4126,13 +4132,6 @@ static int make_request(mddev_t *mddev, struct bio * bi)
bio_endio(bi, 0);
}
- if (mddev->barrier) {
- /* We need to wait for the stripes to all be handled.
- * So: wait for preread_active_stripes to drop to 0.
- */
- wait_event(mddev->thread->wqueue,
- atomic_read(&conf->preread_active_stripes) == 0);
- }
return 0;
}
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index 36eaed5..2ace058 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -275,6 +275,7 @@ struct r6_state {
* filling
*/
#define R5_Wantdrain 13 /* dev->towrite needs to be drained */
+#define R5_WantFUA 14 /* Write should be FUA */
/*
* Write method
*/
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 21/41] md: implment REQ_FLUSH/FUA support
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo
This patch converts md to support REQ_FLUSH/FUA instead of now
deprecated REQ_HARDBARRIER. In the core part (md.c), the following
changes are notable.
* Unlike REQ_HARDBARRIER, REQ_FLUSH/FUA don't interfere with
processing of other requests and thus there is no reason to mark the
queue congested while FLUSH/FUA is in progress.
* REQ_FLUSH/FUA failures are final and its users don't need retry
logic. Retry logic is removed.
* Preflush needs to be issued to all member devices but FUA writes can
be handled the same way as other writes - their processing can be
deferred to request_queue of member devices. md_barrier_request()
is renamed to md_flush_request() and simplified accordingly.
For linear, raid0 and multipath, the core changes are enough. raid1,
5 and 10 need the following conversions.
* raid1: Handling of FLUSH/FUA bio's can simply be deferred to
request_queues of member devices. Barrier related logic removed.
* raid5: Queue draining logic dropped. FUA bit is propagated through
biodrain and stripe resconstruction such that all the updated parts
of the stripe are written out with FUA writes if any of the dirtying
writes was FUA. preread_active_stripes handling in make_request()
is updated as suggested by Neil Brown.
* raid10: FUA bit needs to be propagated to write clones.
linear, raid0, 1, 5 and 10 tested.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Neil Brown <neilb@suse.de>
---
drivers/md/linear.c | 4 +-
drivers/md/md.c | 117 +++++++-------------------------
drivers/md/md.h | 23 ++-----
drivers/md/multipath.c | 4 +-
drivers/md/raid0.c | 4 +-
drivers/md/raid1.c | 176 ++++++++++++++++--------------------------------
drivers/md/raid1.h | 2 -
drivers/md/raid10.c | 7 +-
drivers/md/raid5.c | 43 ++++++------
drivers/md/raid5.h | 1 +
10 files changed, 122 insertions(+), 259 deletions(-)
diff --git a/drivers/md/linear.c b/drivers/md/linear.c
index ba19060..8a2f767 100644
--- a/drivers/md/linear.c
+++ b/drivers/md/linear.c
@@ -294,8 +294,8 @@ static int linear_make_request (mddev_t *mddev, struct bio *bio)
dev_info_t *tmp_dev;
sector_t start_sector;
- if (unlikely(bio->bi_rw & REQ_HARDBARRIER)) {
- md_barrier_request(mddev, bio);
+ if (unlikely(bio->bi_rw & REQ_FLUSH)) {
+ md_flush_request(mddev, bio);
return 0;
}
diff --git a/drivers/md/md.c b/drivers/md/md.c
index c148b63..3640f02 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -226,12 +226,12 @@ static int md_make_request(struct request_queue *q, struct bio *bio)
return 0;
}
rcu_read_lock();
- if (mddev->suspended || mddev->barrier) {
+ if (mddev->suspended) {
DEFINE_WAIT(__wait);
for (;;) {
prepare_to_wait(&mddev->sb_wait, &__wait,
TASK_UNINTERRUPTIBLE);
- if (!mddev->suspended && !mddev->barrier)
+ if (!mddev->suspended)
break;
rcu_read_unlock();
schedule();
@@ -282,40 +282,29 @@ EXPORT_SYMBOL_GPL(mddev_resume);
int mddev_congested(mddev_t *mddev, int bits)
{
- if (mddev->barrier)
- return 1;
return mddev->suspended;
}
EXPORT_SYMBOL(mddev_congested);
/*
- * Generic barrier handling for md
+ * Generic flush handling for md
*/
-#define POST_REQUEST_BARRIER ((void*)1)
-
-static void md_end_barrier(struct bio *bio, int err)
+static void md_end_flush(struct bio *bio, int err)
{
mdk_rdev_t *rdev = bio->bi_private;
mddev_t *mddev = rdev->mddev;
- if (err == -EOPNOTSUPP && mddev->barrier != POST_REQUEST_BARRIER)
- set_bit(BIO_EOPNOTSUPP, &mddev->barrier->bi_flags);
rdev_dec_pending(rdev, mddev);
if (atomic_dec_and_test(&mddev->flush_pending)) {
- if (mddev->barrier == POST_REQUEST_BARRIER) {
- /* This was a post-request barrier */
- mddev->barrier = NULL;
- wake_up(&mddev->sb_wait);
- } else
- /* The pre-request barrier has finished */
- schedule_work(&mddev->barrier_work);
+ /* The pre-request flush has finished */
+ schedule_work(&mddev->flush_work);
}
bio_put(bio);
}
-static void submit_barriers(mddev_t *mddev)
+static void submit_flushes(mddev_t *mddev)
{
mdk_rdev_t *rdev;
@@ -332,60 +321,56 @@ static void submit_barriers(mddev_t *mddev)
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
bi = bio_alloc(GFP_KERNEL, 0);
- bi->bi_end_io = md_end_barrier;
+ bi->bi_end_io = md_end_flush;
bi->bi_private = rdev;
bi->bi_bdev = rdev->bdev;
atomic_inc(&mddev->flush_pending);
- submit_bio(WRITE_BARRIER, bi);
+ submit_bio(WRITE_FLUSH, bi);
rcu_read_lock();
rdev_dec_pending(rdev, mddev);
}
rcu_read_unlock();
}
-static void md_submit_barrier(struct work_struct *ws)
+static void md_submit_flush_data(struct work_struct *ws)
{
- mddev_t *mddev = container_of(ws, mddev_t, barrier_work);
- struct bio *bio = mddev->barrier;
+ mddev_t *mddev = container_of(ws, mddev_t, flush_work);
+ struct bio *bio = mddev->flush_bio;
atomic_set(&mddev->flush_pending, 1);
- if (test_bit(BIO_EOPNOTSUPP, &bio->bi_flags))
- bio_endio(bio, -EOPNOTSUPP);
- else if (bio->bi_size == 0)
+ if (bio->bi_size == 0)
/* an empty barrier - all done */
bio_endio(bio, 0);
else {
- bio->bi_rw &= ~REQ_HARDBARRIER;
+ bio->bi_rw &= ~REQ_FLUSH;
if (mddev->pers->make_request(mddev, bio))
generic_make_request(bio);
- mddev->barrier = POST_REQUEST_BARRIER;
- submit_barriers(mddev);
}
if (atomic_dec_and_test(&mddev->flush_pending)) {
- mddev->barrier = NULL;
+ mddev->flush_bio = NULL;
wake_up(&mddev->sb_wait);
}
}
-void md_barrier_request(mddev_t *mddev, struct bio *bio)
+void md_flush_request(mddev_t *mddev, struct bio *bio)
{
spin_lock_irq(&mddev->write_lock);
wait_event_lock_irq(mddev->sb_wait,
- !mddev->barrier,
+ !mddev->flush_bio,
mddev->write_lock, /*nothing*/);
- mddev->barrier = bio;
+ mddev->flush_bio = bio;
spin_unlock_irq(&mddev->write_lock);
atomic_set(&mddev->flush_pending, 1);
- INIT_WORK(&mddev->barrier_work, md_submit_barrier);
+ INIT_WORK(&mddev->flush_work, md_submit_flush_data);
- submit_barriers(mddev);
+ submit_flushes(mddev);
if (atomic_dec_and_test(&mddev->flush_pending))
- schedule_work(&mddev->barrier_work);
+ schedule_work(&mddev->flush_work);
}
-EXPORT_SYMBOL(md_barrier_request);
+EXPORT_SYMBOL(md_flush_request);
/* Support for plugging.
* This mirrors the plugging support in request_queue, but does not
@@ -696,31 +681,6 @@ static void super_written(struct bio *bio, int error)
bio_put(bio);
}
-static void super_written_barrier(struct bio *bio, int error)
-{
- struct bio *bio2 = bio->bi_private;
- mdk_rdev_t *rdev = bio2->bi_private;
- mddev_t *mddev = rdev->mddev;
-
- if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
- error == -EOPNOTSUPP) {
- unsigned long flags;
- /* barriers don't appear to be supported :-( */
- set_bit(BarriersNotsupp, &rdev->flags);
- mddev->barriers_work = 0;
- spin_lock_irqsave(&mddev->write_lock, flags);
- bio2->bi_next = mddev->biolist;
- mddev->biolist = bio2;
- spin_unlock_irqrestore(&mddev->write_lock, flags);
- wake_up(&mddev->sb_wait);
- bio_put(bio);
- } else {
- bio_put(bio2);
- bio->bi_private = rdev;
- super_written(bio, error);
- }
-}
-
void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
sector_t sector, int size, struct page *page)
{
@@ -729,51 +689,28 @@ void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
* and decrement it on completion, waking up sb_wait
* if zero is reached.
* If an error occurred, call md_error
- *
- * As we might need to resubmit the request if REQ_HARDBARRIER
- * causes ENOTSUPP, we allocate a spare bio...
*/
struct bio *bio = bio_alloc(GFP_NOIO, 1);
- int rw = REQ_WRITE | REQ_SYNC | REQ_UNPLUG;
bio->bi_bdev = rdev->bdev;
bio->bi_sector = sector;
bio_add_page(bio, page, size, 0);
bio->bi_private = rdev;
bio->bi_end_io = super_written;
- bio->bi_rw = rw;
atomic_inc(&mddev->pending_writes);
- if (!test_bit(BarriersNotsupp, &rdev->flags)) {
- struct bio *rbio;
- rw |= REQ_HARDBARRIER;
- rbio = bio_clone(bio, GFP_NOIO);
- rbio->bi_private = bio;
- rbio->bi_end_io = super_written_barrier;
- submit_bio(rw, rbio);
- } else
- submit_bio(rw, bio);
+ submit_bio(REQ_WRITE | REQ_SYNC | REQ_UNPLUG | REQ_FLUSH | REQ_FUA,
+ bio);
}
void md_super_wait(mddev_t *mddev)
{
- /* wait for all superblock writes that were scheduled to complete.
- * if any had to be retried (due to BARRIER problems), retry them
- */
+ /* wait for all superblock writes that were scheduled to complete */
DEFINE_WAIT(wq);
for(;;) {
prepare_to_wait(&mddev->sb_wait, &wq, TASK_UNINTERRUPTIBLE);
if (atomic_read(&mddev->pending_writes)==0)
break;
- while (mddev->biolist) {
- struct bio *bio;
- spin_lock_irq(&mddev->write_lock);
- bio = mddev->biolist;
- mddev->biolist = bio->bi_next ;
- bio->bi_next = NULL;
- spin_unlock_irq(&mddev->write_lock);
- submit_bio(bio->bi_rw, bio);
- }
schedule();
}
finish_wait(&mddev->sb_wait, &wq);
@@ -1070,7 +1007,6 @@ static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
clear_bit(Faulty, &rdev->flags);
clear_bit(In_sync, &rdev->flags);
clear_bit(WriteMostly, &rdev->flags);
- clear_bit(BarriersNotsupp, &rdev->flags);
if (mddev->raid_disks == 0) {
mddev->major_version = 0;
@@ -1485,7 +1421,6 @@ static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
clear_bit(Faulty, &rdev->flags);
clear_bit(In_sync, &rdev->flags);
clear_bit(WriteMostly, &rdev->flags);
- clear_bit(BarriersNotsupp, &rdev->flags);
if (mddev->raid_disks == 0) {
mddev->major_version = 1;
@@ -4506,7 +4441,6 @@ int md_run(mddev_t *mddev)
/* may be over-ridden by personality */
mddev->resync_max_sectors = mddev->dev_sectors;
- mddev->barriers_work = 1;
mddev->ok_start_degraded = start_dirty_degraded;
if (start_readonly && mddev->ro == 0)
@@ -4685,7 +4619,6 @@ static void md_clean(mddev_t *mddev)
mddev->recovery = 0;
mddev->in_sync = 0;
mddev->degraded = 0;
- mddev->barriers_work = 0;
mddev->safemode = 0;
mddev->bitmap_info.offset = 0;
mddev->bitmap_info.default_offset = 0;
diff --git a/drivers/md/md.h b/drivers/md/md.h
index a953fe2..d8e2ab2 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -87,7 +87,6 @@ struct mdk_rdev_s
#define Faulty 1 /* device is known to have a fault */
#define In_sync 2 /* device is in_sync with rest of array */
#define WriteMostly 4 /* Avoid reading if at all possible */
-#define BarriersNotsupp 5 /* REQ_HARDBARRIER is not supported */
#define AllReserved 6 /* If whole device is reserved for
* one array */
#define AutoDetected 7 /* added by auto-detect */
@@ -273,13 +272,6 @@ struct mddev_s
int degraded; /* whether md should consider
* adding a spare
*/
- int barriers_work; /* initialised to true, cleared as soon
- * as a barrier request to slave
- * fails. Only supported
- */
- struct bio *biolist; /* bios that need to be retried
- * because REQ_HARDBARRIER is not supported
- */
atomic_t recovery_active; /* blocks scheduled, but not written */
wait_queue_head_t recovery_wait;
@@ -339,16 +331,13 @@ struct mddev_s
struct attribute_group *to_remove;
struct plug_handle *plug; /* if used by personality */
- /* Generic barrier handling.
- * If there is a pending barrier request, all other
- * writes are blocked while the devices are flushed.
- * The last to finish a flush schedules a worker to
- * submit the barrier request (without the barrier flag),
- * then submit more flush requests.
+ /* Generic flush handling.
+ * The last to finish preflush schedules a worker to submit
+ * the rest of the request (without the REQ_FLUSH flag).
*/
- struct bio *barrier;
+ struct bio *flush_bio;
atomic_t flush_pending;
- struct work_struct barrier_work;
+ struct work_struct flush_work;
struct work_struct event_work; /* used by dm to report failure event */
};
@@ -502,7 +491,7 @@ extern void md_done_sync(mddev_t *mddev, int blocks, int ok);
extern void md_error(mddev_t *mddev, mdk_rdev_t *rdev);
extern int mddev_congested(mddev_t *mddev, int bits);
-extern void md_barrier_request(mddev_t *mddev, struct bio *bio);
+extern void md_flush_request(mddev_t *mddev, struct bio *bio);
extern void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
sector_t sector, int size, struct page *page);
extern void md_super_wait(mddev_t *mddev);
diff --git a/drivers/md/multipath.c b/drivers/md/multipath.c
index 0307d21..6d7ddf3 100644
--- a/drivers/md/multipath.c
+++ b/drivers/md/multipath.c
@@ -142,8 +142,8 @@ static int multipath_make_request(mddev_t *mddev, struct bio * bio)
struct multipath_bh * mp_bh;
struct multipath_info *multipath;
- if (unlikely(bio->bi_rw & REQ_HARDBARRIER)) {
- md_barrier_request(mddev, bio);
+ if (unlikely(bio->bi_rw & REQ_FLUSH)) {
+ md_flush_request(mddev, bio);
return 0;
}
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 6f7af46..a39f4c3 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -483,8 +483,8 @@ static int raid0_make_request(mddev_t *mddev, struct bio *bio)
struct strip_zone *zone;
mdk_rdev_t *tmp_dev;
- if (unlikely(bio->bi_rw & REQ_HARDBARRIER)) {
- md_barrier_request(mddev, bio);
+ if (unlikely(bio->bi_rw & REQ_FLUSH)) {
+ md_flush_request(mddev, bio);
return 0;
}
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index ad83a4d..886a9d8 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -319,83 +319,74 @@ static void raid1_end_write_request(struct bio *bio, int error)
if (r1_bio->bios[mirror] == bio)
break;
- if (error == -EOPNOTSUPP && test_bit(R1BIO_Barrier, &r1_bio->state)) {
- set_bit(BarriersNotsupp, &conf->mirrors[mirror].rdev->flags);
- set_bit(R1BIO_BarrierRetry, &r1_bio->state);
- r1_bio->mddev->barriers_work = 0;
- /* Don't rdev_dec_pending in this branch - keep it for the retry */
- } else {
+ /*
+ * 'one mirror IO has finished' event handler:
+ */
+ r1_bio->bios[mirror] = NULL;
+ to_put = bio;
+ if (!uptodate) {
+ md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
+ /* an I/O failed, we can't clear the bitmap */
+ set_bit(R1BIO_Degraded, &r1_bio->state);
+ } else
/*
- * this branch is our 'one mirror IO has finished' event handler:
+ * Set R1BIO_Uptodate in our master bio, so that we
+ * will return a good error code for to the higher
+ * levels even if IO on some other mirrored buffer
+ * fails.
+ *
+ * The 'master' represents the composite IO operation
+ * to user-side. So if something waits for IO, then it
+ * will wait for the 'master' bio.
*/
- r1_bio->bios[mirror] = NULL;
- to_put = bio;
- if (!uptodate) {
- md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
- /* an I/O failed, we can't clear the bitmap */
- set_bit(R1BIO_Degraded, &r1_bio->state);
- } else
- /*
- * Set R1BIO_Uptodate in our master bio, so that
- * we will return a good error code for to the higher
- * levels even if IO on some other mirrored buffer fails.
- *
- * The 'master' represents the composite IO operation to
- * user-side. So if something waits for IO, then it will
- * wait for the 'master' bio.
- */
- set_bit(R1BIO_Uptodate, &r1_bio->state);
-
- update_head_pos(mirror, r1_bio);
-
- if (behind) {
- if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
- atomic_dec(&r1_bio->behind_remaining);
-
- /* In behind mode, we ACK the master bio once the I/O has safely
- * reached all non-writemostly disks. Setting the Returned bit
- * ensures that this gets done only once -- we don't ever want to
- * return -EIO here, instead we'll wait */
-
- if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
- test_bit(R1BIO_Uptodate, &r1_bio->state)) {
- /* Maybe we can return now */
- if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
- struct bio *mbio = r1_bio->master_bio;
- PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n",
- (unsigned long long) mbio->bi_sector,
- (unsigned long long) mbio->bi_sector +
- (mbio->bi_size >> 9) - 1);
- bio_endio(mbio, 0);
- }
+ set_bit(R1BIO_Uptodate, &r1_bio->state);
+
+ update_head_pos(mirror, r1_bio);
+
+ if (behind) {
+ if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
+ atomic_dec(&r1_bio->behind_remaining);
+
+ /*
+ * In behind mode, we ACK the master bio once the I/O
+ * has safely reached all non-writemostly
+ * disks. Setting the Returned bit ensures that this
+ * gets done only once -- we don't ever want to return
+ * -EIO here, instead we'll wait
+ */
+ if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
+ test_bit(R1BIO_Uptodate, &r1_bio->state)) {
+ /* Maybe we can return now */
+ if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
+ struct bio *mbio = r1_bio->master_bio;
+ PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n",
+ (unsigned long long) mbio->bi_sector,
+ (unsigned long long) mbio->bi_sector +
+ (mbio->bi_size >> 9) - 1);
+ bio_endio(mbio, 0);
}
}
- rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
}
+ rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
+
/*
- *
* Let's see if all mirrored write operations have finished
* already.
*/
if (atomic_dec_and_test(&r1_bio->remaining)) {
- if (test_bit(R1BIO_BarrierRetry, &r1_bio->state))
- reschedule_retry(r1_bio);
- else {
- /* it really is the end of this request */
- if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
- /* free extra copy of the data pages */
- int i = bio->bi_vcnt;
- while (i--)
- safe_put_page(bio->bi_io_vec[i].bv_page);
- }
- /* clear the bitmap if all writes complete successfully */
- bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
- r1_bio->sectors,
- !test_bit(R1BIO_Degraded, &r1_bio->state),
- behind);
- md_write_end(r1_bio->mddev);
- raid_end_bio_io(r1_bio);
+ if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
+ /* free extra copy of the data pages */
+ int i = bio->bi_vcnt;
+ while (i--)
+ safe_put_page(bio->bi_io_vec[i].bv_page);
}
+ /* clear the bitmap if all writes complete successfully */
+ bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
+ r1_bio->sectors,
+ !test_bit(R1BIO_Degraded, &r1_bio->state),
+ behind);
+ md_write_end(r1_bio->mddev);
+ raid_end_bio_io(r1_bio);
}
if (to_put)
@@ -788,16 +779,13 @@ static int make_request(mddev_t *mddev, struct bio * bio)
struct page **behind_pages = NULL;
const int rw = bio_data_dir(bio);
const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
- unsigned long do_barriers;
+ const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
mdk_rdev_t *blocked_rdev;
/*
* Register the new request and wait if the reconstruction
* thread has put up a bar for new requests.
* Continue immediately if no resync is active currently.
- * We test barriers_work *after* md_write_start as md_write_start
- * may cause the first superblock write, and that will check out
- * if barriers work.
*/
md_write_start(mddev, bio); /* wait on superblock update early */
@@ -821,13 +809,6 @@ static int make_request(mddev_t *mddev, struct bio * bio)
}
finish_wait(&conf->wait_barrier, &w);
}
- if (unlikely(!mddev->barriers_work &&
- (bio->bi_rw & REQ_HARDBARRIER))) {
- if (rw == WRITE)
- md_write_end(mddev);
- bio_endio(bio, -EOPNOTSUPP);
- return 0;
- }
wait_barrier(conf);
@@ -959,10 +940,6 @@ static int make_request(mddev_t *mddev, struct bio * bio)
atomic_set(&r1_bio->remaining, 0);
atomic_set(&r1_bio->behind_remaining, 0);
- do_barriers = bio->bi_rw & REQ_HARDBARRIER;
- if (do_barriers)
- set_bit(R1BIO_Barrier, &r1_bio->state);
-
bio_list_init(&bl);
for (i = 0; i < disks; i++) {
struct bio *mbio;
@@ -975,7 +952,7 @@ static int make_request(mddev_t *mddev, struct bio * bio)
mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset;
mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
mbio->bi_end_io = raid1_end_write_request;
- mbio->bi_rw = WRITE | do_barriers | do_sync;
+ mbio->bi_rw = WRITE | do_flush_fua | do_sync;
mbio->bi_private = r1_bio;
if (behind_pages) {
@@ -1634,41 +1611,6 @@ static void raid1d(mddev_t *mddev)
if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
sync_request_write(mddev, r1_bio);
unplug = 1;
- } else if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) {
- /* some requests in the r1bio were REQ_HARDBARRIER
- * requests which failed with -EOPNOTSUPP. Hohumm..
- * Better resubmit without the barrier.
- * We know which devices to resubmit for, because
- * all others have had their bios[] entry cleared.
- * We already have a nr_pending reference on these rdevs.
- */
- int i;
- const unsigned long do_sync = (r1_bio->master_bio->bi_rw & REQ_SYNC);
- clear_bit(R1BIO_BarrierRetry, &r1_bio->state);
- clear_bit(R1BIO_Barrier, &r1_bio->state);
- for (i=0; i < conf->raid_disks; i++)
- if (r1_bio->bios[i])
- atomic_inc(&r1_bio->remaining);
- for (i=0; i < conf->raid_disks; i++)
- if (r1_bio->bios[i]) {
- struct bio_vec *bvec;
- int j;
-
- bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
- /* copy pages from the failed bio, as
- * this might be a write-behind device */
- __bio_for_each_segment(bvec, bio, j, 0)
- bvec->bv_page = bio_iovec_idx(r1_bio->bios[i], j)->bv_page;
- bio_put(r1_bio->bios[i]);
- bio->bi_sector = r1_bio->sector +
- conf->mirrors[i].rdev->data_offset;
- bio->bi_bdev = conf->mirrors[i].rdev->bdev;
- bio->bi_end_io = raid1_end_write_request;
- bio->bi_rw = WRITE | do_sync;
- bio->bi_private = r1_bio;
- r1_bio->bios[i] = bio;
- generic_make_request(bio);
- }
} else {
int disk;
diff --git a/drivers/md/raid1.h b/drivers/md/raid1.h
index 5f2d443..adf8cfd 100644
--- a/drivers/md/raid1.h
+++ b/drivers/md/raid1.h
@@ -117,8 +117,6 @@ struct r1bio_s {
#define R1BIO_IsSync 1
#define R1BIO_Degraded 2
#define R1BIO_BehindIO 3
-#define R1BIO_Barrier 4
-#define R1BIO_BarrierRetry 5
/* For write-behind requests, we call bi_end_io when
* the last non-write-behind device completes, providing
* any write was successful. Otherwise we call when
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 8471838..f0d082f 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -800,12 +800,13 @@ static int make_request(mddev_t *mddev, struct bio * bio)
int chunk_sects = conf->chunk_mask + 1;
const int rw = bio_data_dir(bio);
const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
+ const unsigned long do_fua = (bio->bi_rw & REQ_FUA);
struct bio_list bl;
unsigned long flags;
mdk_rdev_t *blocked_rdev;
- if (unlikely(bio->bi_rw & REQ_HARDBARRIER)) {
- md_barrier_request(mddev, bio);
+ if (unlikely(bio->bi_rw & REQ_FLUSH)) {
+ md_flush_request(mddev, bio);
return 0;
}
@@ -965,7 +966,7 @@ static int make_request(mddev_t *mddev, struct bio * bio)
conf->mirrors[d].rdev->data_offset;
mbio->bi_bdev = conf->mirrors[d].rdev->bdev;
mbio->bi_end_io = raid10_end_write_request;
- mbio->bi_rw = WRITE | do_sync;
+ mbio->bi_rw = WRITE | do_sync | do_fua;
mbio->bi_private = r10_bio;
atomic_inc(&r10_bio->remaining);
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 69b0a16..31140d1 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -506,9 +506,12 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
int rw;
struct bio *bi;
mdk_rdev_t *rdev;
- if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags))
- rw = WRITE;
- else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
+ if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) {
+ if (test_and_clear_bit(R5_WantFUA, &sh->dev[i].flags))
+ rw = WRITE_FUA;
+ else
+ rw = WRITE;
+ } else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
rw = READ;
else
continue;
@@ -1031,6 +1034,8 @@ ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
while (wbi && wbi->bi_sector <
dev->sector + STRIPE_SECTORS) {
+ if (wbi->bi_rw & REQ_FUA)
+ set_bit(R5_WantFUA, &dev->flags);
tx = async_copy_data(1, wbi, dev->page,
dev->sector, tx);
wbi = r5_next_bio(wbi, dev->sector);
@@ -1048,15 +1053,22 @@ static void ops_complete_reconstruct(void *stripe_head_ref)
int pd_idx = sh->pd_idx;
int qd_idx = sh->qd_idx;
int i;
+ bool fua = false;
pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
+ for (i = disks; i--; )
+ fua |= test_bit(R5_WantFUA, &sh->dev[i].flags);
+
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
- if (dev->written || i == pd_idx || i == qd_idx)
+ if (dev->written || i == pd_idx || i == qd_idx) {
set_bit(R5_UPTODATE, &dev->flags);
+ if (fua)
+ set_bit(R5_WantFUA, &dev->flags);
+ }
}
if (sh->reconstruct_state == reconstruct_state_drain_run)
@@ -3281,7 +3293,7 @@ static void handle_stripe5(struct stripe_head *sh)
if (dec_preread_active) {
/* We delay this until after ops_run_io so that if make_request
- * is waiting on a barrier, it won't continue until the writes
+ * is waiting on a flush, it won't continue until the writes
* have actually been submitted.
*/
atomic_dec(&conf->preread_active_stripes);
@@ -3583,7 +3595,7 @@ static void handle_stripe6(struct stripe_head *sh)
if (dec_preread_active) {
/* We delay this until after ops_run_io so that if make_request
- * is waiting on a barrier, it won't continue until the writes
+ * is waiting on a flush, it won't continue until the writes
* have actually been submitted.
*/
atomic_dec(&conf->preread_active_stripes);
@@ -3978,14 +3990,8 @@ static int make_request(mddev_t *mddev, struct bio * bi)
const int rw = bio_data_dir(bi);
int remaining;
- if (unlikely(bi->bi_rw & REQ_HARDBARRIER)) {
- /* Drain all pending writes. We only really need
- * to ensure they have been submitted, but this is
- * easier.
- */
- mddev->pers->quiesce(mddev, 1);
- mddev->pers->quiesce(mddev, 0);
- md_barrier_request(mddev, bi);
+ if (unlikely(bi->bi_rw & REQ_FLUSH)) {
+ md_flush_request(mddev, bi);
return 0;
}
@@ -4103,7 +4109,7 @@ static int make_request(mddev_t *mddev, struct bio * bi)
finish_wait(&conf->wait_for_overlap, &w);
set_bit(STRIPE_HANDLE, &sh->state);
clear_bit(STRIPE_DELAYED, &sh->state);
- if (mddev->barrier &&
+ if ((bi->bi_rw & REQ_SYNC) &&
!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
atomic_inc(&conf->preread_active_stripes);
release_stripe(sh);
@@ -4126,13 +4132,6 @@ static int make_request(mddev_t *mddev, struct bio * bi)
bio_endio(bi, 0);
}
- if (mddev->barrier) {
- /* We need to wait for the stripes to all be handled.
- * So: wait for preread_active_stripes to drop to 0.
- */
- wait_event(mddev->thread->wqueue,
- atomic_read(&conf->preread_active_stripes) == 0);
- }
return 0;
}
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index 36eaed5..2ace058 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -275,6 +275,7 @@ struct r6_state {
* filling
*/
#define R5_Wantdrain 13 /* dev->towrite needs to be drained */
+#define R5_WantFUA 14 /* Write should be FUA */
/*
* Write method
*/
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 22/41] block: make __blk_rq_prep_clone() copy most command flags
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
Currently __blk_rq_prep_clone() copies only REQ_WRITE and REQ_DISCARD.
There's no reason to omit other command flags and REQ_FUA needs to be
copied to implement FUA support in request-based dm.
REQ_COMMON_MASK which specifies flags to be copied from bio to request
already identifies all the command flags. Define REQ_CLONE_MASK to be
the same as REQ_COMMON_MASK for clarity and make __blk_rq_prep_clone()
copy all flags in the mask.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
block/blk-core.c | 4 +---
include/linux/blk_types.h | 1 +
2 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 495bdc4..2a5b192 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -2505,9 +2505,7 @@ EXPORT_SYMBOL_GPL(blk_rq_unprep_clone);
static void __blk_rq_prep_clone(struct request *dst, struct request *src)
{
dst->cpu = src->cpu;
- dst->cmd_flags = (rq_data_dir(src) | REQ_NOMERGE);
- if (src->cmd_flags & REQ_DISCARD)
- dst->cmd_flags |= REQ_DISCARD;
+ dst->cmd_flags = (src->cmd_flags & REQ_CLONE_MASK) | REQ_NOMERGE;
dst->cmd_type = src->cmd_type;
dst->__sector = blk_rq_pos(src);
dst->__data_len = blk_rq_bytes(src);
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 1797994..36edadf 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -168,6 +168,7 @@ enum rq_flag_bits {
#define REQ_COMMON_MASK \
(REQ_WRITE | REQ_FAILFAST_MASK | REQ_HARDBARRIER | REQ_SYNC | \
REQ_META | REQ_DISCARD | REQ_NOIDLE | REQ_FLUSH | REQ_FUA)
+#define REQ_CLONE_MASK REQ_COMMON_MASK
#define REQ_UNPLUG (1 << __REQ_UNPLUG)
#define REQ_RAHEAD (1 << __REQ_RAHEAD)
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 22/41] block: make __blk_rq_prep_clone() copy most command flags
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
Currently __blk_rq_prep_clone() copies only REQ_WRITE and REQ_DISCARD.
There's no reason to omit other command flags and REQ_FUA needs to be
copied to implement FUA support in request-based dm.
REQ_COMMON_MASK which specifies flags to be copied from bio to request
already identifies all the command flags. Define REQ_CLONE_MASK to be
the same as REQ_COMMON_MASK for clarity and make __blk_rq_prep_clone()
copy all flags in the mask.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
block/blk-core.c | 4 +---
include/linux/blk_types.h | 1 +
2 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 495bdc4..2a5b192 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -2505,9 +2505,7 @@ EXPORT_SYMBOL_GPL(blk_rq_unprep_clone);
static void __blk_rq_prep_clone(struct request *dst, struct request *src)
{
dst->cpu = src->cpu;
- dst->cmd_flags = (rq_data_dir(src) | REQ_NOMERGE);
- if (src->cmd_flags & REQ_DISCARD)
- dst->cmd_flags |= REQ_DISCARD;
+ dst->cmd_flags = (src->cmd_flags & REQ_CLONE_MASK) | REQ_NOMERGE;
dst->cmd_type = src->cmd_type;
dst->__sector = blk_rq_pos(src);
dst->__data_len = blk_rq_bytes(src);
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 1797994..36edadf 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -168,6 +168,7 @@ enum rq_flag_bits {
#define REQ_COMMON_MASK \
(REQ_WRITE | REQ_FAILFAST_MASK | REQ_HARDBARRIER | REQ_SYNC | \
REQ_META | REQ_DISCARD | REQ_NOIDLE | REQ_FLUSH | REQ_FUA)
+#define REQ_CLONE_MASK REQ_COMMON_MASK
#define REQ_UNPLUG (1 << __REQ_UNPLUG)
#define REQ_RAHEAD (1 << __REQ_RAHEAD)
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 22/41] block: make __blk_rq_prep_clone() copy most command flags
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo
Currently __blk_rq_prep_clone() copies only REQ_WRITE and REQ_DISCARD.
There's no reason to omit other command flags and REQ_FUA needs to be
copied to implement FUA support in request-based dm.
REQ_COMMON_MASK which specifies flags to be copied from bio to request
already identifies all the command flags. Define REQ_CLONE_MASK to be
the same as REQ_COMMON_MASK for clarity and make __blk_rq_prep_clone()
copy all flags in the mask.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
block/blk-core.c | 4 +---
include/linux/blk_types.h | 1 +
2 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 495bdc4..2a5b192 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -2505,9 +2505,7 @@ EXPORT_SYMBOL_GPL(blk_rq_unprep_clone);
static void __blk_rq_prep_clone(struct request *dst, struct request *src)
{
dst->cpu = src->cpu;
- dst->cmd_flags = (rq_data_dir(src) | REQ_NOMERGE);
- if (src->cmd_flags & REQ_DISCARD)
- dst->cmd_flags |= REQ_DISCARD;
+ dst->cmd_flags = (src->cmd_flags & REQ_CLONE_MASK) | REQ_NOMERGE;
dst->cmd_type = src->cmd_type;
dst->__sector = blk_rq_pos(src);
dst->__data_len = blk_rq_bytes(src);
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 1797994..36edadf 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -168,6 +168,7 @@ enum rq_flag_bits {
#define REQ_COMMON_MASK \
(REQ_WRITE | REQ_FAILFAST_MASK | REQ_HARDBARRIER | REQ_SYNC | \
REQ_META | REQ_DISCARD | REQ_NOIDLE | REQ_FLUSH | REQ_FUA)
+#define REQ_CLONE_MASK REQ_COMMON_MASK
#define REQ_UNPLUG (1 << __REQ_UNPLUG)
#define REQ_RAHEAD (1 << __REQ_RAHEAD)
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 23/41] dm: implement REQ_FLUSH/FUA support for bio-based dm
2010-09-03 10:29 ` Tejun Heo
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel
Cc: Tejun Heo
This patch converts bio-based dm to support REQ_FLUSH/FUA instead of
now deprecated REQ_HARDBARRIER.
* -EOPNOTSUPP handling logic dropped.
* Preflush is handled as before but postflush is dropped and replaced
with passing down REQ_FUA to member request_queues. This replaces
one array wide cache flush w/ member specific FUA writes.
* __split_and_process_bio() now calls __clone_and_map_flush() directly
for flushes and guarantees all FLUSH bio's going to targets are zero
` length.
* It's now guaranteed that all FLUSH bio's which are passed onto dm
targets are zero length. bio_empty_barrier() tests are replaced
with REQ_FLUSH tests.
* Empty WRITE_BARRIERs are replaced with WRITE_FLUSHes.
* Dropped unlikely() around REQ_FLUSH tests. Flushes are not unlikely
enough to be marked with unlikely().
* Block layer now filters out REQ_FLUSH/FUA bio's if the request_queue
doesn't support cache flushing. Advertise REQ_FLUSH | REQ_FUA
capability.
* Request based dm isn't converted yet. dm_init_request_based_queue()
resets flush support to 0 for now. To avoid disturbing request
based dm code, dm->flush_error is added for bio based dm while
requested based dm continues to use dm->barrier_error.
Lightly tested linear, stripe, raid1, snap and crypt targets. Please
proceed with caution as I'm not familiar with the code base.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: dm-devel@redhat.com
Cc: Christoph Hellwig <hch@lst.de>
---
drivers/md/dm-crypt.c | 2 +-
drivers/md/dm-io.c | 20 +-----
drivers/md/dm-log.c | 2 +-
drivers/md/dm-raid1.c | 8 +-
drivers/md/dm-region-hash.c | 16 +++---
drivers/md/dm-snap-persistent.c | 2 +-
drivers/md/dm-snap.c | 6 +-
drivers/md/dm-stripe.c | 2 +-
drivers/md/dm.c | 119 +++++++++++++++++++--------------------
9 files changed, 80 insertions(+), 97 deletions(-)
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 368e8e9..d5b0e4c 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1278,7 +1278,7 @@ static int crypt_map(struct dm_target *ti, struct bio *bio,
struct dm_crypt_io *io;
struct crypt_config *cc;
- if (unlikely(bio_empty_barrier(bio))) {
+ if (bio->bi_rw & REQ_FLUSH) {
cc = ti->private;
bio->bi_bdev = cc->dev->bdev;
return DM_MAPIO_REMAPPED;
diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index 0590c75..136d4f7 100644
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -31,7 +31,6 @@ struct dm_io_client {
*/
struct io {
unsigned long error_bits;
- unsigned long eopnotsupp_bits;
atomic_t count;
struct task_struct *sleeper;
struct dm_io_client *client;
@@ -130,11 +129,8 @@ static void retrieve_io_and_region_from_bio(struct bio *bio, struct io **io,
*---------------------------------------------------------------*/
static void dec_count(struct io *io, unsigned int region, int error)
{
- if (error) {
+ if (error)
set_bit(region, &io->error_bits);
- if (error == -EOPNOTSUPP)
- set_bit(region, &io->eopnotsupp_bits);
- }
if (atomic_dec_and_test(&io->count)) {
if (io->sleeper)
@@ -310,8 +306,8 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where,
sector_t remaining = where->count;
/*
- * where->count may be zero if rw holds a write barrier and we
- * need to send a zero-sized barrier.
+ * where->count may be zero if rw holds a flush and we need to
+ * send a zero-sized flush.
*/
do {
/*
@@ -364,7 +360,7 @@ static void dispatch_io(int rw, unsigned int num_regions,
*/
for (i = 0; i < num_regions; i++) {
*dp = old_pages;
- if (where[i].count || (rw & REQ_HARDBARRIER))
+ if (where[i].count || (rw & REQ_FLUSH))
do_region(rw, i, where + i, dp, io);
}
@@ -393,9 +389,7 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions,
return -EIO;
}
-retry:
io->error_bits = 0;
- io->eopnotsupp_bits = 0;
atomic_set(&io->count, 1); /* see dispatch_io() */
io->sleeper = current;
io->client = client;
@@ -412,11 +406,6 @@ retry:
}
set_current_state(TASK_RUNNING);
- if (io->eopnotsupp_bits && (rw & REQ_HARDBARRIER)) {
- rw &= ~REQ_HARDBARRIER;
- goto retry;
- }
-
if (error_bits)
*error_bits = io->error_bits;
@@ -437,7 +426,6 @@ static int async_io(struct dm_io_client *client, unsigned int num_regions,
io = mempool_alloc(client->pool, GFP_NOIO);
io->error_bits = 0;
- io->eopnotsupp_bits = 0;
atomic_set(&io->count, 1); /* see dispatch_io() */
io->sleeper = NULL;
io->client = client;
diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c
index 5a08be0..33420e6 100644
--- a/drivers/md/dm-log.c
+++ b/drivers/md/dm-log.c
@@ -300,7 +300,7 @@ static int flush_header(struct log_c *lc)
.count = 0,
};
- lc->io_req.bi_rw = WRITE_BARRIER;
+ lc->io_req.bi_rw = WRITE_FLUSH;
return dm_io(&lc->io_req, 1, &null_location, NULL);
}
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index 7c081bc..19a59b0 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -259,7 +259,7 @@ static int mirror_flush(struct dm_target *ti)
struct dm_io_region io[ms->nr_mirrors];
struct mirror *m;
struct dm_io_request io_req = {
- .bi_rw = WRITE_BARRIER,
+ .bi_rw = WRITE_FLUSH,
.mem.type = DM_IO_KMEM,
.mem.ptr.bvec = NULL,
.client = ms->io_client,
@@ -629,7 +629,7 @@ static void do_write(struct mirror_set *ms, struct bio *bio)
struct dm_io_region io[ms->nr_mirrors], *dest = io;
struct mirror *m;
struct dm_io_request io_req = {
- .bi_rw = WRITE | (bio->bi_rw & WRITE_BARRIER),
+ .bi_rw = WRITE | (bio->bi_rw & WRITE_FLUSH_FUA),
.mem.type = DM_IO_BVEC,
.mem.ptr.bvec = bio->bi_io_vec + bio->bi_idx,
.notify.fn = write_callback,
@@ -670,7 +670,7 @@ static void do_writes(struct mirror_set *ms, struct bio_list *writes)
bio_list_init(&requeue);
while ((bio = bio_list_pop(writes))) {
- if (unlikely(bio_empty_barrier(bio))) {
+ if (bio->bi_rw & REQ_FLUSH) {
bio_list_add(&sync, bio);
continue;
}
@@ -1203,7 +1203,7 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio,
* We need to dec pending if this was a write.
*/
if (rw == WRITE) {
- if (likely(!bio_empty_barrier(bio)))
+ if (!(bio->bi_rw & REQ_FLUSH))
dm_rh_dec(ms->rh, map_context->ll);
return error;
}
diff --git a/drivers/md/dm-region-hash.c b/drivers/md/dm-region-hash.c
index bd5c58b..dad011a 100644
--- a/drivers/md/dm-region-hash.c
+++ b/drivers/md/dm-region-hash.c
@@ -81,9 +81,9 @@ struct dm_region_hash {
struct list_head failed_recovered_regions;
/*
- * If there was a barrier failure no regions can be marked clean.
+ * If there was a flush failure no regions can be marked clean.
*/
- int barrier_failure;
+ int flush_failure;
void *context;
sector_t target_begin;
@@ -217,7 +217,7 @@ struct dm_region_hash *dm_region_hash_create(
INIT_LIST_HEAD(&rh->quiesced_regions);
INIT_LIST_HEAD(&rh->recovered_regions);
INIT_LIST_HEAD(&rh->failed_recovered_regions);
- rh->barrier_failure = 0;
+ rh->flush_failure = 0;
rh->region_pool = mempool_create_kmalloc_pool(MIN_REGIONS,
sizeof(struct dm_region));
@@ -399,8 +399,8 @@ void dm_rh_mark_nosync(struct dm_region_hash *rh, struct bio *bio)
region_t region = dm_rh_bio_to_region(rh, bio);
int recovering = 0;
- if (bio_empty_barrier(bio)) {
- rh->barrier_failure = 1;
+ if (bio->bi_rw & REQ_FLUSH) {
+ rh->flush_failure = 1;
return;
}
@@ -524,7 +524,7 @@ void dm_rh_inc_pending(struct dm_region_hash *rh, struct bio_list *bios)
struct bio *bio;
for (bio = bios->head; bio; bio = bio->bi_next) {
- if (bio_empty_barrier(bio))
+ if (bio->bi_rw & REQ_FLUSH)
continue;
rh_inc(rh, dm_rh_bio_to_region(rh, bio));
}
@@ -555,9 +555,9 @@ void dm_rh_dec(struct dm_region_hash *rh, region_t region)
*/
/* do nothing for DM_RH_NOSYNC */
- if (unlikely(rh->barrier_failure)) {
+ if (unlikely(rh->flush_failure)) {
/*
- * If a write barrier failed some time ago, we
+ * If a write flush failed some time ago, we
* don't know whether or not this write made it
* to the disk, so we must resync the device.
*/
diff --git a/drivers/md/dm-snap-persistent.c b/drivers/md/dm-snap-persistent.c
index cc2bdb8..0b61792 100644
--- a/drivers/md/dm-snap-persistent.c
+++ b/drivers/md/dm-snap-persistent.c
@@ -687,7 +687,7 @@ static void persistent_commit_exception(struct dm_exception_store *store,
/*
* Commit exceptions to disk.
*/
- if (ps->valid && area_io(ps, WRITE_BARRIER))
+ if (ps->valid && area_io(ps, WRITE_FLUSH_FUA))
ps->valid = 0;
/*
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 5974d30..eed2101 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -1587,7 +1587,7 @@ static int snapshot_map(struct dm_target *ti, struct bio *bio,
chunk_t chunk;
struct dm_snap_pending_exception *pe = NULL;
- if (unlikely(bio_empty_barrier(bio))) {
+ if (bio->bi_rw & REQ_FLUSH) {
bio->bi_bdev = s->cow->bdev;
return DM_MAPIO_REMAPPED;
}
@@ -1691,7 +1691,7 @@ static int snapshot_merge_map(struct dm_target *ti, struct bio *bio,
int r = DM_MAPIO_REMAPPED;
chunk_t chunk;
- if (unlikely(bio_empty_barrier(bio))) {
+ if (bio->bi_rw & REQ_FLUSH) {
if (!map_context->target_request_nr)
bio->bi_bdev = s->origin->bdev;
else
@@ -2135,7 +2135,7 @@ static int origin_map(struct dm_target *ti, struct bio *bio,
struct dm_dev *dev = ti->private;
bio->bi_bdev = dev->bdev;
- if (unlikely(bio_empty_barrier(bio)))
+ if (bio->bi_rw & REQ_FLUSH)
return DM_MAPIO_REMAPPED;
/* Only tell snapshots if this is a write */
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index c297f6d..f0371b4 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -271,7 +271,7 @@ static int stripe_map(struct dm_target *ti, struct bio *bio,
uint32_t stripe;
unsigned target_request_nr;
- if (unlikely(bio_empty_barrier(bio))) {
+ if (bio->bi_rw & REQ_FLUSH) {
target_request_nr = map_context->target_request_nr;
BUG_ON(target_request_nr >= sc->stripes);
bio->bi_bdev = sc->stripe[target_request_nr].dev->bdev;
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index b1d92be..32e6622 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -144,15 +144,16 @@ struct mapped_device {
spinlock_t deferred_lock;
/*
- * An error from the barrier request currently being processed.
+ * An error from the flush request currently being processed.
*/
- int barrier_error;
+ int flush_error;
/*
* Protect barrier_error from concurrent endio processing
* in request-based dm.
*/
spinlock_t barrier_error_lock;
+ int barrier_error;
/*
* Processing queue (flush/barriers)
@@ -200,8 +201,8 @@ struct mapped_device {
/* sysfs handle */
struct kobject kobj;
- /* zero-length barrier that will be cloned and submitted to targets */
- struct bio barrier_bio;
+ /* zero-length flush that will be cloned and submitted to targets */
+ struct bio flush_bio;
};
/*
@@ -512,7 +513,7 @@ static void end_io_acct(struct dm_io *io)
/*
* After this is decremented the bio must not be touched if it is
- * a barrier.
+ * a flush.
*/
dm_disk(md)->part0.in_flight[rw] = pending =
atomic_dec_return(&md->pending[rw]);
@@ -626,7 +627,7 @@ static void dec_pending(struct dm_io *io, int error)
*/
spin_lock_irqsave(&md->deferred_lock, flags);
if (__noflush_suspending(md)) {
- if (!(io->bio->bi_rw & REQ_HARDBARRIER))
+ if (!(io->bio->bi_rw & REQ_FLUSH))
bio_list_add_head(&md->deferred,
io->bio);
} else
@@ -638,20 +639,14 @@ static void dec_pending(struct dm_io *io, int error)
io_error = io->error;
bio = io->bio;
- if (bio->bi_rw & REQ_HARDBARRIER) {
+ if (bio->bi_rw & REQ_FLUSH) {
/*
- * There can be just one barrier request so we use
+ * There can be just one flush request so we use
* a per-device variable for error reporting.
* Note that you can't touch the bio after end_io_acct
- *
- * We ignore -EOPNOTSUPP for empty flush reported by
- * underlying devices. We assume that if the device
- * doesn't support empty barriers, it doesn't need
- * cache flushing commands.
*/
- if (!md->barrier_error &&
- !(bio_empty_barrier(bio) && io_error == -EOPNOTSUPP))
- md->barrier_error = io_error;
+ if (!md->flush_error)
+ md->flush_error = io_error;
end_io_acct(io);
free_io(md, io);
} else {
@@ -1119,7 +1114,7 @@ static void dm_bio_destructor(struct bio *bio)
}
/*
- * Creates a little bio that is just does part of a bvec.
+ * Creates a little bio that just does part of a bvec.
*/
static struct bio *split_bvec(struct bio *bio, sector_t sector,
unsigned short idx, unsigned int offset,
@@ -1134,7 +1129,7 @@ static struct bio *split_bvec(struct bio *bio, sector_t sector,
clone->bi_sector = sector;
clone->bi_bdev = bio->bi_bdev;
- clone->bi_rw = bio->bi_rw & ~REQ_HARDBARRIER;
+ clone->bi_rw = bio->bi_rw;
clone->bi_vcnt = 1;
clone->bi_size = to_bytes(len);
clone->bi_io_vec->bv_offset = offset;
@@ -1161,7 +1156,6 @@ static struct bio *clone_bio(struct bio *bio, sector_t sector,
clone = bio_alloc_bioset(GFP_NOIO, bio->bi_max_vecs, bs);
__bio_clone(clone, bio);
- clone->bi_rw &= ~REQ_HARDBARRIER;
clone->bi_destructor = dm_bio_destructor;
clone->bi_sector = sector;
clone->bi_idx = idx;
@@ -1225,7 +1219,7 @@ static void __issue_target_requests(struct clone_info *ci, struct dm_target *ti,
__issue_target_request(ci, ti, request_nr, len);
}
-static int __clone_and_map_empty_barrier(struct clone_info *ci)
+static int __clone_and_map_flush(struct clone_info *ci)
{
unsigned target_nr = 0;
struct dm_target *ti;
@@ -1289,9 +1283,6 @@ static int __clone_and_map(struct clone_info *ci)
sector_t len = 0, max;
struct dm_target_io *tio;
- if (unlikely(bio_empty_barrier(bio)))
- return __clone_and_map_empty_barrier(ci);
-
if (unlikely(bio->bi_rw & REQ_DISCARD))
return __clone_and_map_discard(ci);
@@ -1383,11 +1374,11 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
ci.map = dm_get_live_table(md);
if (unlikely(!ci.map)) {
- if (!(bio->bi_rw & REQ_HARDBARRIER))
+ if (!(bio->bi_rw & REQ_FLUSH))
bio_io_error(bio);
else
- if (!md->barrier_error)
- md->barrier_error = -EIO;
+ if (!md->flush_error)
+ md->flush_error = -EIO;
return;
}
@@ -1400,14 +1391,22 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
ci.io->md = md;
spin_lock_init(&ci.io->endio_lock);
ci.sector = bio->bi_sector;
- ci.sector_count = bio_sectors(bio);
- if (unlikely(bio_empty_barrier(bio)))
+ if (!(bio->bi_rw & REQ_FLUSH))
+ ci.sector_count = bio_sectors(bio);
+ else {
+ /* all FLUSH bio's reaching here should be empty */
+ WARN_ON_ONCE(bio_has_data(bio));
ci.sector_count = 1;
+ }
ci.idx = bio->bi_idx;
start_io_acct(ci.io);
- while (ci.sector_count && !error)
- error = __clone_and_map(&ci);
+ while (ci.sector_count && !error) {
+ if (!(bio->bi_rw & REQ_FLUSH))
+ error = __clone_and_map(&ci);
+ else
+ error = __clone_and_map_flush(&ci);
+ }
/* drop the extra reference count */
dec_pending(ci.io, error);
@@ -1492,11 +1491,11 @@ static int _dm_request(struct request_queue *q, struct bio *bio)
part_stat_unlock();
/*
- * If we're suspended or the thread is processing barriers
+ * If we're suspended or the thread is processing flushes
* we have to queue this io for later.
*/
if (unlikely(test_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags)) ||
- unlikely(bio->bi_rw & REQ_HARDBARRIER)) {
+ (bio->bi_rw & REQ_FLUSH)) {
up_read(&md->io_lock);
if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) &&
@@ -1940,6 +1939,7 @@ static void dm_init_md_queue(struct mapped_device *md)
blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY);
md->queue->unplug_fn = dm_unplug_all;
blk_queue_merge_bvec(md->queue, dm_merge_bvec);
+ blk_queue_flush(md->queue, REQ_FLUSH | REQ_FUA);
}
/*
@@ -2245,7 +2245,8 @@ static int dm_init_request_based_queue(struct mapped_device *md)
blk_queue_softirq_done(md->queue, dm_softirq_done);
blk_queue_prep_rq(md->queue, dm_prep_fn);
blk_queue_lld_busy(md->queue, dm_lld_busy);
- blk_queue_flush(md->queue, REQ_FLUSH);
+ /* no flush support for request based dm yet */
+ blk_queue_flush(md->queue, 0);
elv_register_queue(md->queue);
@@ -2406,41 +2407,35 @@ static int dm_wait_for_completion(struct mapped_device *md, int interruptible)
return r;
}
-static void dm_flush(struct mapped_device *md)
+static void process_flush(struct mapped_device *md, struct bio *bio)
{
- dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
-
- bio_init(&md->barrier_bio);
- md->barrier_bio.bi_bdev = md->bdev;
- md->barrier_bio.bi_rw = WRITE_BARRIER;
- __split_and_process_bio(md, &md->barrier_bio);
+ md->flush_error = 0;
+ /* handle REQ_FLUSH */
dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
-}
-static void process_barrier(struct mapped_device *md, struct bio *bio)
-{
- md->barrier_error = 0;
+ bio_init(&md->flush_bio);
+ md->flush_bio.bi_bdev = md->bdev;
+ md->flush_bio.bi_rw = WRITE_FLUSH;
+ __split_and_process_bio(md, &md->flush_bio);
- dm_flush(md);
+ dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
- if (!bio_empty_barrier(bio)) {
- __split_and_process_bio(md, bio);
- /*
- * If the request isn't supported, don't waste time with
- * the second flush.
- */
- if (md->barrier_error != -EOPNOTSUPP)
- dm_flush(md);
+ /* if it's an empty flush or the preflush failed, we're done */
+ if (!bio_has_data(bio) || md->flush_error) {
+ if (md->flush_error != DM_ENDIO_REQUEUE)
+ bio_endio(bio, md->flush_error);
+ else {
+ spin_lock_irq(&md->deferred_lock);
+ bio_list_add_head(&md->deferred, bio);
+ spin_unlock_irq(&md->deferred_lock);
+ }
+ return;
}
- if (md->barrier_error != DM_ENDIO_REQUEUE)
- bio_endio(bio, md->barrier_error);
- else {
- spin_lock_irq(&md->deferred_lock);
- bio_list_add_head(&md->deferred, bio);
- spin_unlock_irq(&md->deferred_lock);
- }
+ /* issue data + REQ_FUA */
+ bio->bi_rw &= ~REQ_FLUSH;
+ __split_and_process_bio(md, bio);
}
/*
@@ -2469,8 +2464,8 @@ static void dm_wq_work(struct work_struct *work)
if (dm_request_based(md))
generic_make_request(c);
else {
- if (c->bi_rw & REQ_HARDBARRIER)
- process_barrier(md, c);
+ if (c->bi_rw & REQ_FLUSH)
+ process_flush(md, c);
else
__split_and_process_bio(md, c);
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 23/41] dm: implement REQ_FLUSH/FUA support for bio-based dm
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo
This patch converts bio-based dm to support REQ_FLUSH/FUA instead of
now deprecated REQ_HARDBARRIER.
* -EOPNOTSUPP handling logic dropped.
* Preflush is handled as before but postflush is dropped and replaced
with passing down REQ_FUA to member request_queues. This replaces
one array wide cache flush w/ member specific FUA writes.
* __split_and_process_bio() now calls __clone_and_map_flush() directly
for flushes and guarantees all FLUSH bio's going to targets are zero
` length.
* It's now guaranteed that all FLUSH bio's which are passed onto dm
targets are zero length. bio_empty_barrier() tests are replaced
with REQ_FLUSH tests.
* Empty WRITE_BARRIERs are replaced with WRITE_FLUSHes.
* Dropped unlikely() around REQ_FLUSH tests. Flushes are not unlikely
enough to be marked with unlikely().
* Block layer now filters out REQ_FLUSH/FUA bio's if the request_queue
doesn't support cache flushing. Advertise REQ_FLUSH | REQ_FUA
capability.
* Request based dm isn't converted yet. dm_init_request_based_queue()
resets flush support to 0 for now. To avoid disturbing request
based dm code, dm->flush_error is added for bio based dm while
requested based dm continues to use dm->barrier_error.
Lightly tested linear, stripe, raid1, snap and crypt targets. Please
proceed with caution as I'm not familiar with the code base.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: dm-devel@redhat.com
Cc: Christoph Hellwig <hch@lst.de>
---
drivers/md/dm-crypt.c | 2 +-
drivers/md/dm-io.c | 20 +-----
drivers/md/dm-log.c | 2 +-
drivers/md/dm-raid1.c | 8 +-
drivers/md/dm-region-hash.c | 16 +++---
drivers/md/dm-snap-persistent.c | 2 +-
drivers/md/dm-snap.c | 6 +-
drivers/md/dm-stripe.c | 2 +-
drivers/md/dm.c | 119 +++++++++++++++++++--------------------
9 files changed, 80 insertions(+), 97 deletions(-)
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 368e8e9..d5b0e4c 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1278,7 +1278,7 @@ static int crypt_map(struct dm_target *ti, struct bio *bio,
struct dm_crypt_io *io;
struct crypt_config *cc;
- if (unlikely(bio_empty_barrier(bio))) {
+ if (bio->bi_rw & REQ_FLUSH) {
cc = ti->private;
bio->bi_bdev = cc->dev->bdev;
return DM_MAPIO_REMAPPED;
diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index 0590c75..136d4f7 100644
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -31,7 +31,6 @@ struct dm_io_client {
*/
struct io {
unsigned long error_bits;
- unsigned long eopnotsupp_bits;
atomic_t count;
struct task_struct *sleeper;
struct dm_io_client *client;
@@ -130,11 +129,8 @@ static void retrieve_io_and_region_from_bio(struct bio *bio, struct io **io,
*---------------------------------------------------------------*/
static void dec_count(struct io *io, unsigned int region, int error)
{
- if (error) {
+ if (error)
set_bit(region, &io->error_bits);
- if (error == -EOPNOTSUPP)
- set_bit(region, &io->eopnotsupp_bits);
- }
if (atomic_dec_and_test(&io->count)) {
if (io->sleeper)
@@ -310,8 +306,8 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where,
sector_t remaining = where->count;
/*
- * where->count may be zero if rw holds a write barrier and we
- * need to send a zero-sized barrier.
+ * where->count may be zero if rw holds a flush and we need to
+ * send a zero-sized flush.
*/
do {
/*
@@ -364,7 +360,7 @@ static void dispatch_io(int rw, unsigned int num_regions,
*/
for (i = 0; i < num_regions; i++) {
*dp = old_pages;
- if (where[i].count || (rw & REQ_HARDBARRIER))
+ if (where[i].count || (rw & REQ_FLUSH))
do_region(rw, i, where + i, dp, io);
}
@@ -393,9 +389,7 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions,
return -EIO;
}
-retry:
io->error_bits = 0;
- io->eopnotsupp_bits = 0;
atomic_set(&io->count, 1); /* see dispatch_io() */
io->sleeper = current;
io->client = client;
@@ -412,11 +406,6 @@ retry:
}
set_current_state(TASK_RUNNING);
- if (io->eopnotsupp_bits && (rw & REQ_HARDBARRIER)) {
- rw &= ~REQ_HARDBARRIER;
- goto retry;
- }
-
if (error_bits)
*error_bits = io->error_bits;
@@ -437,7 +426,6 @@ static int async_io(struct dm_io_client *client, unsigned int num_regions,
io = mempool_alloc(client->pool, GFP_NOIO);
io->error_bits = 0;
- io->eopnotsupp_bits = 0;
atomic_set(&io->count, 1); /* see dispatch_io() */
io->sleeper = NULL;
io->client = client;
diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c
index 5a08be0..33420e6 100644
--- a/drivers/md/dm-log.c
+++ b/drivers/md/dm-log.c
@@ -300,7 +300,7 @@ static int flush_header(struct log_c *lc)
.count = 0,
};
- lc->io_req.bi_rw = WRITE_BARRIER;
+ lc->io_req.bi_rw = WRITE_FLUSH;
return dm_io(&lc->io_req, 1, &null_location, NULL);
}
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index 7c081bc..19a59b0 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -259,7 +259,7 @@ static int mirror_flush(struct dm_target *ti)
struct dm_io_region io[ms->nr_mirrors];
struct mirror *m;
struct dm_io_request io_req = {
- .bi_rw = WRITE_BARRIER,
+ .bi_rw = WRITE_FLUSH,
.mem.type = DM_IO_KMEM,
.mem.ptr.bvec = NULL,
.client = ms->io_client,
@@ -629,7 +629,7 @@ static void do_write(struct mirror_set *ms, struct bio *bio)
struct dm_io_region io[ms->nr_mirrors], *dest = io;
struct mirror *m;
struct dm_io_request io_req = {
- .bi_rw = WRITE | (bio->bi_rw & WRITE_BARRIER),
+ .bi_rw = WRITE | (bio->bi_rw & WRITE_FLUSH_FUA),
.mem.type = DM_IO_BVEC,
.mem.ptr.bvec = bio->bi_io_vec + bio->bi_idx,
.notify.fn = write_callback,
@@ -670,7 +670,7 @@ static void do_writes(struct mirror_set *ms, struct bio_list *writes)
bio_list_init(&requeue);
while ((bio = bio_list_pop(writes))) {
- if (unlikely(bio_empty_barrier(bio))) {
+ if (bio->bi_rw & REQ_FLUSH) {
bio_list_add(&sync, bio);
continue;
}
@@ -1203,7 +1203,7 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio,
* We need to dec pending if this was a write.
*/
if (rw == WRITE) {
- if (likely(!bio_empty_barrier(bio)))
+ if (!(bio->bi_rw & REQ_FLUSH))
dm_rh_dec(ms->rh, map_context->ll);
return error;
}
diff --git a/drivers/md/dm-region-hash.c b/drivers/md/dm-region-hash.c
index bd5c58b..dad011a 100644
--- a/drivers/md/dm-region-hash.c
+++ b/drivers/md/dm-region-hash.c
@@ -81,9 +81,9 @@ struct dm_region_hash {
struct list_head failed_recovered_regions;
/*
- * If there was a barrier failure no regions can be marked clean.
+ * If there was a flush failure no regions can be marked clean.
*/
- int barrier_failure;
+ int flush_failure;
void *context;
sector_t target_begin;
@@ -217,7 +217,7 @@ struct dm_region_hash *dm_region_hash_create(
INIT_LIST_HEAD(&rh->quiesced_regions);
INIT_LIST_HEAD(&rh->recovered_regions);
INIT_LIST_HEAD(&rh->failed_recovered_regions);
- rh->barrier_failure = 0;
+ rh->flush_failure = 0;
rh->region_pool = mempool_create_kmalloc_pool(MIN_REGIONS,
sizeof(struct dm_region));
@@ -399,8 +399,8 @@ void dm_rh_mark_nosync(struct dm_region_hash *rh, struct bio *bio)
region_t region = dm_rh_bio_to_region(rh, bio);
int recovering = 0;
- if (bio_empty_barrier(bio)) {
- rh->barrier_failure = 1;
+ if (bio->bi_rw & REQ_FLUSH) {
+ rh->flush_failure = 1;
return;
}
@@ -524,7 +524,7 @@ void dm_rh_inc_pending(struct dm_region_hash *rh, struct bio_list *bios)
struct bio *bio;
for (bio = bios->head; bio; bio = bio->bi_next) {
- if (bio_empty_barrier(bio))
+ if (bio->bi_rw & REQ_FLUSH)
continue;
rh_inc(rh, dm_rh_bio_to_region(rh, bio));
}
@@ -555,9 +555,9 @@ void dm_rh_dec(struct dm_region_hash *rh, region_t region)
*/
/* do nothing for DM_RH_NOSYNC */
- if (unlikely(rh->barrier_failure)) {
+ if (unlikely(rh->flush_failure)) {
/*
- * If a write barrier failed some time ago, we
+ * If a write flush failed some time ago, we
* don't know whether or not this write made it
* to the disk, so we must resync the device.
*/
diff --git a/drivers/md/dm-snap-persistent.c b/drivers/md/dm-snap-persistent.c
index cc2bdb8..0b61792 100644
--- a/drivers/md/dm-snap-persistent.c
+++ b/drivers/md/dm-snap-persistent.c
@@ -687,7 +687,7 @@ static void persistent_commit_exception(struct dm_exception_store *store,
/*
* Commit exceptions to disk.
*/
- if (ps->valid && area_io(ps, WRITE_BARRIER))
+ if (ps->valid && area_io(ps, WRITE_FLUSH_FUA))
ps->valid = 0;
/*
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 5974d30..eed2101 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -1587,7 +1587,7 @@ static int snapshot_map(struct dm_target *ti, struct bio *bio,
chunk_t chunk;
struct dm_snap_pending_exception *pe = NULL;
- if (unlikely(bio_empty_barrier(bio))) {
+ if (bio->bi_rw & REQ_FLUSH) {
bio->bi_bdev = s->cow->bdev;
return DM_MAPIO_REMAPPED;
}
@@ -1691,7 +1691,7 @@ static int snapshot_merge_map(struct dm_target *ti, struct bio *bio,
int r = DM_MAPIO_REMAPPED;
chunk_t chunk;
- if (unlikely(bio_empty_barrier(bio))) {
+ if (bio->bi_rw & REQ_FLUSH) {
if (!map_context->target_request_nr)
bio->bi_bdev = s->origin->bdev;
else
@@ -2135,7 +2135,7 @@ static int origin_map(struct dm_target *ti, struct bio *bio,
struct dm_dev *dev = ti->private;
bio->bi_bdev = dev->bdev;
- if (unlikely(bio_empty_barrier(bio)))
+ if (bio->bi_rw & REQ_FLUSH)
return DM_MAPIO_REMAPPED;
/* Only tell snapshots if this is a write */
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index c297f6d..f0371b4 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -271,7 +271,7 @@ static int stripe_map(struct dm_target *ti, struct bio *bio,
uint32_t stripe;
unsigned target_request_nr;
- if (unlikely(bio_empty_barrier(bio))) {
+ if (bio->bi_rw & REQ_FLUSH) {
target_request_nr = map_context->target_request_nr;
BUG_ON(target_request_nr >= sc->stripes);
bio->bi_bdev = sc->stripe[target_request_nr].dev->bdev;
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index b1d92be..32e6622 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -144,15 +144,16 @@ struct mapped_device {
spinlock_t deferred_lock;
/*
- * An error from the barrier request currently being processed.
+ * An error from the flush request currently being processed.
*/
- int barrier_error;
+ int flush_error;
/*
* Protect barrier_error from concurrent endio processing
* in request-based dm.
*/
spinlock_t barrier_error_lock;
+ int barrier_error;
/*
* Processing queue (flush/barriers)
@@ -200,8 +201,8 @@ struct mapped_device {
/* sysfs handle */
struct kobject kobj;
- /* zero-length barrier that will be cloned and submitted to targets */
- struct bio barrier_bio;
+ /* zero-length flush that will be cloned and submitted to targets */
+ struct bio flush_bio;
};
/*
@@ -512,7 +513,7 @@ static void end_io_acct(struct dm_io *io)
/*
* After this is decremented the bio must not be touched if it is
- * a barrier.
+ * a flush.
*/
dm_disk(md)->part0.in_flight[rw] = pending =
atomic_dec_return(&md->pending[rw]);
@@ -626,7 +627,7 @@ static void dec_pending(struct dm_io *io, int error)
*/
spin_lock_irqsave(&md->deferred_lock, flags);
if (__noflush_suspending(md)) {
- if (!(io->bio->bi_rw & REQ_HARDBARRIER))
+ if (!(io->bio->bi_rw & REQ_FLUSH))
bio_list_add_head(&md->deferred,
io->bio);
} else
@@ -638,20 +639,14 @@ static void dec_pending(struct dm_io *io, int error)
io_error = io->error;
bio = io->bio;
- if (bio->bi_rw & REQ_HARDBARRIER) {
+ if (bio->bi_rw & REQ_FLUSH) {
/*
- * There can be just one barrier request so we use
+ * There can be just one flush request so we use
* a per-device variable for error reporting.
* Note that you can't touch the bio after end_io_acct
- *
- * We ignore -EOPNOTSUPP for empty flush reported by
- * underlying devices. We assume that if the device
- * doesn't support empty barriers, it doesn't need
- * cache flushing commands.
*/
- if (!md->barrier_error &&
- !(bio_empty_barrier(bio) && io_error == -EOPNOTSUPP))
- md->barrier_error = io_error;
+ if (!md->flush_error)
+ md->flush_error = io_error;
end_io_acct(io);
free_io(md, io);
} else {
@@ -1119,7 +1114,7 @@ static void dm_bio_destructor(struct bio *bio)
}
/*
- * Creates a little bio that is just does part of a bvec.
+ * Creates a little bio that just does part of a bvec.
*/
static struct bio *split_bvec(struct bio *bio, sector_t sector,
unsigned short idx, unsigned int offset,
@@ -1134,7 +1129,7 @@ static struct bio *split_bvec(struct bio *bio, sector_t sector,
clone->bi_sector = sector;
clone->bi_bdev = bio->bi_bdev;
- clone->bi_rw = bio->bi_rw & ~REQ_HARDBARRIER;
+ clone->bi_rw = bio->bi_rw;
clone->bi_vcnt = 1;
clone->bi_size = to_bytes(len);
clone->bi_io_vec->bv_offset = offset;
@@ -1161,7 +1156,6 @@ static struct bio *clone_bio(struct bio *bio, sector_t sector,
clone = bio_alloc_bioset(GFP_NOIO, bio->bi_max_vecs, bs);
__bio_clone(clone, bio);
- clone->bi_rw &= ~REQ_HARDBARRIER;
clone->bi_destructor = dm_bio_destructor;
clone->bi_sector = sector;
clone->bi_idx = idx;
@@ -1225,7 +1219,7 @@ static void __issue_target_requests(struct clone_info *ci, struct dm_target *ti,
__issue_target_request(ci, ti, request_nr, len);
}
-static int __clone_and_map_empty_barrier(struct clone_info *ci)
+static int __clone_and_map_flush(struct clone_info *ci)
{
unsigned target_nr = 0;
struct dm_target *ti;
@@ -1289,9 +1283,6 @@ static int __clone_and_map(struct clone_info *ci)
sector_t len = 0, max;
struct dm_target_io *tio;
- if (unlikely(bio_empty_barrier(bio)))
- return __clone_and_map_empty_barrier(ci);
-
if (unlikely(bio->bi_rw & REQ_DISCARD))
return __clone_and_map_discard(ci);
@@ -1383,11 +1374,11 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
ci.map = dm_get_live_table(md);
if (unlikely(!ci.map)) {
- if (!(bio->bi_rw & REQ_HARDBARRIER))
+ if (!(bio->bi_rw & REQ_FLUSH))
bio_io_error(bio);
else
- if (!md->barrier_error)
- md->barrier_error = -EIO;
+ if (!md->flush_error)
+ md->flush_error = -EIO;
return;
}
@@ -1400,14 +1391,22 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
ci.io->md = md;
spin_lock_init(&ci.io->endio_lock);
ci.sector = bio->bi_sector;
- ci.sector_count = bio_sectors(bio);
- if (unlikely(bio_empty_barrier(bio)))
+ if (!(bio->bi_rw & REQ_FLUSH))
+ ci.sector_count = bio_sectors(bio);
+ else {
+ /* all FLUSH bio's reaching here should be empty */
+ WARN_ON_ONCE(bio_has_data(bio));
ci.sector_count = 1;
+ }
ci.idx = bio->bi_idx;
start_io_acct(ci.io);
- while (ci.sector_count && !error)
- error = __clone_and_map(&ci);
+ while (ci.sector_count && !error) {
+ if (!(bio->bi_rw & REQ_FLUSH))
+ error = __clone_and_map(&ci);
+ else
+ error = __clone_and_map_flush(&ci);
+ }
/* drop the extra reference count */
dec_pending(ci.io, error);
@@ -1492,11 +1491,11 @@ static int _dm_request(struct request_queue *q, struct bio *bio)
part_stat_unlock();
/*
- * If we're suspended or the thread is processing barriers
+ * If we're suspended or the thread is processing flushes
* we have to queue this io for later.
*/
if (unlikely(test_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags)) ||
- unlikely(bio->bi_rw & REQ_HARDBARRIER)) {
+ (bio->bi_rw & REQ_FLUSH)) {
up_read(&md->io_lock);
if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) &&
@@ -1940,6 +1939,7 @@ static void dm_init_md_queue(struct mapped_device *md)
blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY);
md->queue->unplug_fn = dm_unplug_all;
blk_queue_merge_bvec(md->queue, dm_merge_bvec);
+ blk_queue_flush(md->queue, REQ_FLUSH | REQ_FUA);
}
/*
@@ -2245,7 +2245,8 @@ static int dm_init_request_based_queue(struct mapped_device *md)
blk_queue_softirq_done(md->queue, dm_softirq_done);
blk_queue_prep_rq(md->queue, dm_prep_fn);
blk_queue_lld_busy(md->queue, dm_lld_busy);
- blk_queue_flush(md->queue, REQ_FLUSH);
+ /* no flush support for request based dm yet */
+ blk_queue_flush(md->queue, 0);
elv_register_queue(md->queue);
@@ -2406,41 +2407,35 @@ static int dm_wait_for_completion(struct mapped_device *md, int interruptible)
return r;
}
-static void dm_flush(struct mapped_device *md)
+static void process_flush(struct mapped_device *md, struct bio *bio)
{
- dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
-
- bio_init(&md->barrier_bio);
- md->barrier_bio.bi_bdev = md->bdev;
- md->barrier_bio.bi_rw = WRITE_BARRIER;
- __split_and_process_bio(md, &md->barrier_bio);
+ md->flush_error = 0;
+ /* handle REQ_FLUSH */
dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
-}
-static void process_barrier(struct mapped_device *md, struct bio *bio)
-{
- md->barrier_error = 0;
+ bio_init(&md->flush_bio);
+ md->flush_bio.bi_bdev = md->bdev;
+ md->flush_bio.bi_rw = WRITE_FLUSH;
+ __split_and_process_bio(md, &md->flush_bio);
- dm_flush(md);
+ dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
- if (!bio_empty_barrier(bio)) {
- __split_and_process_bio(md, bio);
- /*
- * If the request isn't supported, don't waste time with
- * the second flush.
- */
- if (md->barrier_error != -EOPNOTSUPP)
- dm_flush(md);
+ /* if it's an empty flush or the preflush failed, we're done */
+ if (!bio_has_data(bio) || md->flush_error) {
+ if (md->flush_error != DM_ENDIO_REQUEUE)
+ bio_endio(bio, md->flush_error);
+ else {
+ spin_lock_irq(&md->deferred_lock);
+ bio_list_add_head(&md->deferred, bio);
+ spin_unlock_irq(&md->deferred_lock);
+ }
+ return;
}
- if (md->barrier_error != DM_ENDIO_REQUEUE)
- bio_endio(bio, md->barrier_error);
- else {
- spin_lock_irq(&md->deferred_lock);
- bio_list_add_head(&md->deferred, bio);
- spin_unlock_irq(&md->deferred_lock);
- }
+ /* issue data + REQ_FUA */
+ bio->bi_rw &= ~REQ_FLUSH;
+ __split_and_process_bio(md, bio);
}
/*
@@ -2469,8 +2464,8 @@ static void dm_wq_work(struct work_struct *work)
if (dm_request_based(md))
generic_make_request(c);
else {
- if (c->bi_rw & REQ_HARDBARRIER)
- process_barrier(md, c);
+ if (c->bi_rw & REQ_FLUSH)
+ process_flush(md, c);
else
__split_and_process_bio(md, c);
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* Re: [PATCH 23/41] dm: implement REQ_FLUSH/FUA support for bio-based dm
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 12:36 ` Mike Snitzer
-1 siblings, 0 replies; 159+ messages in thread
From: Mike Snitzer @ 2010-09-03 12:36 UTC (permalink / raw)
To: Tejun Heo
Cc: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, k-ueda, mpatocka
On Fri, Sep 03 2010 at 6:29am -0400,
Tejun Heo <tj@kernel.org> wrote:
> This patch converts bio-based dm to support REQ_FLUSH/FUA instead of
> now deprecated REQ_HARDBARRIER.
>
> * -EOPNOTSUPP handling logic dropped.
>
> * Preflush is handled as before but postflush is dropped and replaced
> with passing down REQ_FUA to member request_queues. This replaces
> one array wide cache flush w/ member specific FUA writes.
>
> * __split_and_process_bio() now calls __clone_and_map_flush() directly
> for flushes and guarantees all FLUSH bio's going to targets are zero
> ` length.
>
> * It's now guaranteed that all FLUSH bio's which are passed onto dm
> targets are zero length. bio_empty_barrier() tests are replaced
> with REQ_FLUSH tests.
>
> * Empty WRITE_BARRIERs are replaced with WRITE_FLUSHes.
>
> * Dropped unlikely() around REQ_FLUSH tests. Flushes are not unlikely
> enough to be marked with unlikely().
>
> * Block layer now filters out REQ_FLUSH/FUA bio's if the request_queue
> doesn't support cache flushing. Advertise REQ_FLUSH | REQ_FUA
> capability.
>
> * Request based dm isn't converted yet. dm_init_request_based_queue()
> resets flush support to 0 for now. To avoid disturbing request
> based dm code, dm->flush_error is added for bio based dm while
> requested based dm continues to use dm->barrier_error.
>
> Lightly tested linear, stripe, raid1, snap and crypt targets. Please
> proceed with caution as I'm not familiar with the code base.
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Mikulas and/or Alasdair won't be able to review this until next week.
^ permalink raw reply [flat|nested] 159+ messages in thread
* Re: [dm-devel] [PATCH 23/41] dm: implement REQ_FLUSH/FUA support for bio-based dm
2010-09-03 10:29 ` Tejun Heo
(?)
(?)
@ 2010-09-06 11:14 ` Milan Broz
2010-09-07 21:17 ` Mike Snitzer
-1 siblings, 1 reply; 159+ messages in thread
From: Milan Broz @ 2010-09-06 11:14 UTC (permalink / raw)
To: device-mapper development
Cc: Tejun Heo, jaxboe, linux-kernel, linux-fsdevel, linux-scsi,
linux-ide, linux-raid, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
On 09/03/2010 12:29 PM, Tejun Heo wrote:
> +++ b/drivers/md/dm-crypt.c
> @@ -1278,7 +1278,7 @@ static int crypt_map(struct dm_target *ti, struct bio *bio,
> struct dm_crypt_io *io;
> struct crypt_config *cc;
>
> - if (unlikely(bio_empty_barrier(bio))) {
> + if (bio->bi_rw & REQ_FLUSH) {
> cc = ti->private;
> bio->bi_bdev = cc->dev->bdev;
> return DM_MAPIO_REMAPPED;
...
> +++ b/drivers/md/dm.c
> @@ -1400,14 +1391,22 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
> ci.io->md = md;
> spin_lock_init(&ci.io->endio_lock);
> ci.sector = bio->bi_sector;
> - ci.sector_count = bio_sectors(bio);
> - if (unlikely(bio_empty_barrier(bio)))
> + if (!(bio->bi_rw & REQ_FLUSH))
> + ci.sector_count = bio_sectors(bio);
> + else {
> + /* all FLUSH bio's reaching here should be empty */
> + WARN_ON_ONCE(bio_has_data(bio));
> ci.sector_count = 1;
> + }
I would add BUG_ON(bio_has_data(bio)) either to dm-crypt target or directly to DM core
in this path.
Note that empty barrier request bypass encryption layer now in dm-crypt, so if some bio
with data payload reach it after the change, it causes data corruption
(moreover plain data reach the disk directly).
Milan
^ permalink raw reply [flat|nested] 159+ messages in thread* Re: [PATCH 23/41] dm: implement REQ_FLUSH/FUA support for bio-based dm
2010-09-06 11:14 ` [dm-devel] " Milan Broz
@ 2010-09-07 21:17 ` Mike Snitzer
2010-09-07 22:15 ` Mike Snitzer
0 siblings, 1 reply; 159+ messages in thread
From: Mike Snitzer @ 2010-09-07 21:17 UTC (permalink / raw)
To: Milan Broz
Cc: device-mapper development, Tejun Heo, jaxboe, linux-kernel,
linux-fsdevel, linux-scsi, linux-ide, linux-raid, hch,
konishi.ryusuke, James.Bottomley, tytso, chris.mason, swhiteho,
vst, jack, rwheeler, hare, neilb, rusty, mst, k-ueda, mpatocka
On Mon, Sep 06 2010 at 7:14am -0400,
Milan Broz <mbroz@redhat.com> wrote:
> On 09/03/2010 12:29 PM, Tejun Heo wrote:
>
> > +++ b/drivers/md/dm-crypt.c
> > @@ -1278,7 +1278,7 @@ static int crypt_map(struct dm_target *ti, struct bio *bio,
> > struct dm_crypt_io *io;
> > struct crypt_config *cc;
> >
> > - if (unlikely(bio_empty_barrier(bio))) {
> > + if (bio->bi_rw & REQ_FLUSH) {
> > cc = ti->private;
> > bio->bi_bdev = cc->dev->bdev;
> > return DM_MAPIO_REMAPPED;
>
> ...
>
> > +++ b/drivers/md/dm.c
> > @@ -1400,14 +1391,22 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
> > ci.io->md = md;
> > spin_lock_init(&ci.io->endio_lock);
> > ci.sector = bio->bi_sector;
> > - ci.sector_count = bio_sectors(bio);
> > - if (unlikely(bio_empty_barrier(bio)))
> > + if (!(bio->bi_rw & REQ_FLUSH))
> > + ci.sector_count = bio_sectors(bio);
> > + else {
> > + /* all FLUSH bio's reaching here should be empty */
> > + WARN_ON_ONCE(bio_has_data(bio));
> > ci.sector_count = 1;
> > + }
>
>
> I would add BUG_ON(bio_has_data(bio)) either to dm-crypt target or directly to DM core
> in this path.
I agree, that WARN_ON_ONCE should be changed to BUG_ON. This is a
guarantee that the block layer now provides so it seems correct to have
the DM core bug if that guarantee isn't actually provided.
> Note that empty barrier request bypass encryption layer now in dm-crypt, so if some bio
> with data payload reach it after the change, it causes data corruption
> (moreover plain data reach the disk directly).
Given the consequences, it wouldn't hurt to BUG_ON() in dm-crypt too.
It's redundant if the DM core will also BUG_ON() but it serves as a
dm-crypt safety-net/documentation.
Mike
^ permalink raw reply [flat|nested] 159+ messages in thread* Re: [PATCH 23/41] dm: implement REQ_FLUSH/FUA support for bio-based dm
2010-09-07 21:17 ` Mike Snitzer
@ 2010-09-07 22:15 ` Mike Snitzer
2010-09-07 23:49 ` [PATCH 42/41] dm: convey that all flushes are processed as empty Mike Snitzer
0 siblings, 1 reply; 159+ messages in thread
From: Mike Snitzer @ 2010-09-07 22:15 UTC (permalink / raw)
To: Milan Broz
Cc: jack, mst, linux-ide, device-mapper development, James.Bottomley,
konishi.ryusuke, hch, k-ueda, vst, linux-scsi, rusty, linux-raid,
Tejun Heo, mpatocka, swhiteho, chris.mason, tytso, jaxboe,
linux-kernel, linux-fsdevel, rwheeler
On Tue, Sep 07 2010 at 5:17pm -0400,
Mike Snitzer <snitzer@redhat.com> wrote:
> On Mon, Sep 06 2010 at 7:14am -0400,
> Milan Broz <mbroz@redhat.com> wrote:
>
> > On 09/03/2010 12:29 PM, Tejun Heo wrote:
> >
> > > +++ b/drivers/md/dm-crypt.c
> > > @@ -1278,7 +1278,7 @@ static int crypt_map(struct dm_target *ti, struct bio *bio,
> > > struct dm_crypt_io *io;
> > > struct crypt_config *cc;
> > >
> > > - if (unlikely(bio_empty_barrier(bio))) {
> > > + if (bio->bi_rw & REQ_FLUSH) {
> > > cc = ti->private;
> > > bio->bi_bdev = cc->dev->bdev;
> > > return DM_MAPIO_REMAPPED;
> >
> > ...
> >
> > > +++ b/drivers/md/dm.c
> > > @@ -1400,14 +1391,22 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
> > > ci.io->md = md;
> > > spin_lock_init(&ci.io->endio_lock);
> > > ci.sector = bio->bi_sector;
> > > - ci.sector_count = bio_sectors(bio);
> > > - if (unlikely(bio_empty_barrier(bio)))
> > > + if (!(bio->bi_rw & REQ_FLUSH))
> > > + ci.sector_count = bio_sectors(bio);
> > > + else {
> > > + /* all FLUSH bio's reaching here should be empty */
> > > + WARN_ON_ONCE(bio_has_data(bio));
> > > ci.sector_count = 1;
> > > + }
> >
> >
> > I would add BUG_ON(bio_has_data(bio)) either to dm-crypt target or directly to DM core
> > in this path.
>
> I agree, that WARN_ON_ONCE should be changed to BUG_ON. This is a
> guarantee that the block layer now provides so it seems correct to have
> the DM core bug if that guarantee isn't actually provided.
I was mistaken, DM enforces that guarantee... ;)
(but block layer will also enforce empty flush for request-based)
But it wasn't clear until Christoph and I looked closer. The point
stands though; we should BUG_ON rather than WARN_ON_ONCE.
I'll send a follow-on patch to help clean this code up a bit more (based
on Christoph's suggestions). Mainly just making the flush paths a bit
more distinct and adding some comments.
Mike
^ permalink raw reply [flat|nested] 159+ messages in thread* [PATCH 42/41] dm: convey that all flushes are processed as empty
2010-09-07 22:15 ` Mike Snitzer
@ 2010-09-07 23:49 ` Mike Snitzer
2010-09-08 0:00 ` Christoph Hellwig
0 siblings, 1 reply; 159+ messages in thread
From: Mike Snitzer @ 2010-09-07 23:49 UTC (permalink / raw)
To: Tejun Heo
Cc: jack, mst, linux-ide, device-mapper development, James.Bottomley,
konishi.ryusuke, hch, k-ueda, vst, linux-scsi, rusty, linux-raid,
mpatocka, swhiteho, chris.mason, tytso, jaxboe, linux-kernel,
linux-fsdevel, rwheeler, Milan Broz
Rename __clone_and_map_flush to __clone_and_map_empty_flush for added
clarity.
Reintroduce a BUG_ON() and add a few more helpful comments to the code
so that it is clear that all flushes are empty.
Cleanup __split_and_process_bio() so that an empty flush isn't processed
by a 'sector_count' focused while loop.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
---
drivers/md/dm.c | 21 +++++++++------------
1 files changed, 9 insertions(+), 12 deletions(-)
Tejun, please feel free to fold this patch into (or insert after)
0025-dm-relax-ordering-of-bio-based-flush-implementation.patch
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index cd2f7e7..9a852ee 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -622,6 +622,7 @@ static void dec_pending(struct dm_io *io, int error)
return;
if (!(bio->bi_rw & REQ_FLUSH) || !bio->bi_size) {
+ /* done with normal IO or empty flush */
trace_block_bio_complete(md->queue, bio);
bio_endio(bio, io_error);
} else {
@@ -1132,16 +1133,15 @@ static void __issue_target_requests(struct clone_info *ci, struct dm_target *ti,
__issue_target_request(ci, ti, request_nr, len);
}
-static int __clone_and_map_flush(struct clone_info *ci)
+static int __clone_and_map_empty_flush(struct clone_info *ci)
{
unsigned target_nr = 0;
struct dm_target *ti;
+ BUG_ON(bio_has_data(ci->bio));
while ((ti = dm_table_get_target(ci->map, target_nr++)))
__issue_target_requests(ci, ti, ti->num_flush_requests, 0);
- ci->sector_count = 0;
-
return 0;
}
@@ -1302,20 +1302,17 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
ci.sector = bio->bi_sector;
ci.idx = bio->bi_idx;
+ start_io_acct(ci.io);
if (!is_flush) {
ci.bio = bio;
ci.sector_count = bio_sectors(bio);
+ while (ci.sector_count && !error)
+ error = __clone_and_map(&ci);
} else {
ci.bio = &ci.md->flush_bio;
- ci.sector_count = 1;
- }
-
- start_io_acct(ci.io);
- while (ci.sector_count && !error) {
- if (!is_flush)
- error = __clone_and_map(&ci);
- else
- error = __clone_and_map_flush(&ci);
+ ci.sector_count = 0;
+ error = __clone_and_map_empty_flush(&ci);
+ /* dec_pending submits any data associated with flush */
}
/* drop the extra reference count */
^ permalink raw reply related [flat|nested] 159+ messages in thread* Re: [PATCH 42/41] dm: convey that all flushes are processed as empty
2010-09-07 23:49 ` [PATCH 42/41] dm: convey that all flushes are processed as empty Mike Snitzer
@ 2010-09-08 0:00 ` Christoph Hellwig
2010-09-08 2:04 ` [PATCH 42/41 v2] " Mike Snitzer
0 siblings, 1 reply; 159+ messages in thread
From: Christoph Hellwig @ 2010-09-08 0:00 UTC (permalink / raw)
To: Mike Snitzer
Cc: Tejun Heo, jack, mst, linux-ide, device-mapper development,
James.Bottomley, konishi.ryusuke, hch, k-ueda, vst, linux-scsi,
rusty, linux-raid, mpatocka, swhiteho, chris.mason, tytso,
jaxboe, linux-kernel, linux-fsdevel, rwheeler, Milan Broz
On Tue, Sep 07, 2010 at 07:49:18PM -0400, Mike Snitzer wrote:
> if (!(bio->bi_rw & REQ_FLUSH) || !bio->bi_size) {
> + /* done with normal IO or empty flush */
> trace_block_bio_complete(md->queue, bio);
> bio_endio(bio, io_error);
> } else {
To clarify this further I'd reorder the checks:
if ((bio->bi_rw & REQ_FLUSH) && bio->bi_size) {
/*
* Preflush done, ...
*/
} else {
}
> @@ -1302,20 +1302,17 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
> ci.sector = bio->bi_sector;
> ci.idx = bio->bi_idx;
>
> + start_io_acct(ci.io);
> if (!is_flush) {
no need for the is_flush anymore now that it's only used once. Again,
I think avoiding negatives without a reason in if statement usually
makes the code a bit more clear.
^ permalink raw reply [flat|nested] 159+ messages in thread* [PATCH 42/41 v2] dm: convey that all flushes are processed as empty
2010-09-08 0:00 ` Christoph Hellwig
@ 2010-09-08 2:04 ` Mike Snitzer
2010-09-08 16:09 ` Tejun Heo
2010-09-08 16:09 ` Tejun Heo
0 siblings, 2 replies; 159+ messages in thread
From: Mike Snitzer @ 2010-09-08 2:04 UTC (permalink / raw)
To: Christoph Hellwig
Cc: Tejun Heo, jack, mst, linux-ide, device-mapper development,
James.Bottomley, konishi.ryusuke, k-ueda, vst, linux-scsi, rusty,
linux-raid, mpatocka, swhiteho, chris.mason, tytso, jaxboe,
linux-kernel, linux-fsdevel, rwheeler, Milan Broz
Rename __clone_and_map_flush to __clone_and_map_empty_flush for added
clarity.
Simplify logic associated with REQ_FLUSH conditionals.
Introduce a BUG_ON() and add a few more helpful comments to the code
so that it is clear that all flushes are empty.
Cleanup __split_and_process_bio() so that an empty flush isn't processed
by a 'sector_count' focused while loop.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
---
drivers/md/dm.c | 34 +++++++++++++++-------------------
1 files changed, 15 insertions(+), 19 deletions(-)
Tejun, please feel free to fold this patch into (or insert after)
0025-dm-relax-ordering-of-bio-based-flush-implementation.patch
v2: Simplify logic associated with REQ_FLUSH conditionals
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index cd2f7e7..f934e98 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -621,16 +621,17 @@ static void dec_pending(struct dm_io *io, int error)
if (io_error == DM_ENDIO_REQUEUE)
return;
- if (!(bio->bi_rw & REQ_FLUSH) || !bio->bi_size) {
- trace_block_bio_complete(md->queue, bio);
- bio_endio(bio, io_error);
- } else {
+ if ((bio->bi_rw & REQ_FLUSH) && bio->bi_size) {
/*
* Preflush done for flush with data, reissue
* without REQ_FLUSH.
*/
bio->bi_rw &= ~REQ_FLUSH;
queue_io(md, bio);
+ } else {
+ /* done with normal IO or empty flush */
+ trace_block_bio_complete(md->queue, bio);
+ bio_endio(bio, io_error);
}
}
}
@@ -1132,16 +1133,15 @@ static void __issue_target_requests(struct clone_info *ci, struct dm_target *ti,
__issue_target_request(ci, ti, request_nr, len);
}
-static int __clone_and_map_flush(struct clone_info *ci)
+static int __clone_and_map_empty_flush(struct clone_info *ci)
{
unsigned target_nr = 0;
struct dm_target *ti;
+ BUG_ON(bio_has_data(ci->bio));
while ((ti = dm_table_get_target(ci->map, target_nr++)))
__issue_target_requests(ci, ti, ti->num_flush_requests, 0);
- ci->sector_count = 0;
-
return 0;
}
@@ -1282,7 +1282,6 @@ static int __clone_and_map(struct clone_info *ci)
*/
static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
{
- bool is_flush = bio->bi_rw & REQ_FLUSH;
struct clone_info ci;
int error = 0;
@@ -1302,20 +1301,17 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
ci.sector = bio->bi_sector;
ci.idx = bio->bi_idx;
- if (!is_flush) {
+ start_io_acct(ci.io);
+ if (bio->bi_rw & REQ_FLUSH) {
+ ci.bio = &ci.md->flush_bio;
+ ci.sector_count = 0;
+ error = __clone_and_map_empty_flush(&ci);
+ /* dec_pending submits any data associated with flush */
+ } else {
ci.bio = bio;
ci.sector_count = bio_sectors(bio);
- } else {
- ci.bio = &ci.md->flush_bio;
- ci.sector_count = 1;
- }
-
- start_io_acct(ci.io);
- while (ci.sector_count && !error) {
- if (!is_flush)
+ while (ci.sector_count && !error)
error = __clone_and_map(&ci);
- else
- error = __clone_and_map_flush(&ci);
}
/* drop the extra reference count */
^ permalink raw reply related [flat|nested] 159+ messages in thread* Re: [PATCH 42/41 v2] dm: convey that all flushes are processed as empty
2010-09-08 2:04 ` [PATCH 42/41 v2] " Mike Snitzer
@ 2010-09-08 16:09 ` Tejun Heo
2010-09-08 16:09 ` Tejun Heo
1 sibling, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-08 16:09 UTC (permalink / raw)
To: Mike Snitzer
Cc: Christoph Hellwig, jack, mst, linux-ide,
device-mapper development, James.Bottomley, konishi.ryusuke,
k-ueda, vst, linux-scsi, rusty, linux-raid, mpatocka, swhiteho,
chris.mason, tytso, jaxboe, linux-kernel, linux-fsdevel,
rwheeler, Milan Broz
On 09/08/2010 04:04 AM, Mike Snitzer wrote:
> Rename __clone_and_map_flush to __clone_and_map_empty_flush for added
> clarity.
>
> Simplify logic associated with REQ_FLUSH conditionals.
>
> Introduce a BUG_ON() and add a few more helpful comments to the code
> so that it is clear that all flushes are empty.
>
> Cleanup __split_and_process_bio() so that an empty flush isn't processed
> by a 'sector_count' focused while loop.
>
> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
> ---
> drivers/md/dm.c | 34 +++++++++++++++-------------------
> 1 files changed, 15 insertions(+), 19 deletions(-)
>
> Tejun, please feel free to fold this patch into (or insert after)
> 0025-dm-relax-ordering-of-bio-based-flush-implementation.patch
>
> v2: Simplify logic associated with REQ_FLUSH conditionals
>
> diff --git a/drivers/md/dm.c b/drivers/md/dm.c
> index cd2f7e7..f934e98 100644
> --- a/drivers/md/dm.c
> +++ b/drivers/md/dm.c
> @@ -621,16 +621,17 @@ static void dec_pending(struct dm_io *io, int error)
> if (io_error == DM_ENDIO_REQUEUE)
> return;
>
> - if (!(bio->bi_rw & REQ_FLUSH) || !bio->bi_size) {
> - trace_block_bio_complete(md->queue, bio);
> - bio_endio(bio, io_error);
> - } else {
> + if ((bio->bi_rw & REQ_FLUSH) && bio->bi_size) {
> /*
> * Preflush done for flush with data, reissue
> * without REQ_FLUSH.
> */
> bio->bi_rw &= ~REQ_FLUSH;
> queue_io(md, bio);
> + } else {
> + /* done with normal IO or empty flush */
> + trace_block_bio_complete(md->queue, bio);
> + bio_endio(bio, io_error);
> }
> }
> }
> @@ -1132,16 +1133,15 @@ static void __issue_target_requests(struct clone_info *ci, struct dm_target *ti,
> __issue_target_request(ci, ti, request_nr, len);
> }
>
> -static int __clone_and_map_flush(struct clone_info *ci)
> +static int __clone_and_map_empty_flush(struct clone_info *ci)
> {
> unsigned target_nr = 0;
> struct dm_target *ti;
>
> + BUG_ON(bio_has_data(ci->bio));
> while ((ti = dm_table_get_target(ci->map, target_nr++)))
> __issue_target_requests(ci, ti, ti->num_flush_requests, 0);
>
> - ci->sector_count = 0;
> -
> return 0;
> }
>
> @@ -1282,7 +1282,6 @@ static int __clone_and_map(struct clone_info *ci)
> */
> static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
> {
> - bool is_flush = bio->bi_rw & REQ_FLUSH;
> struct clone_info ci;
> int error = 0;
>
> @@ -1302,20 +1301,17 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
> ci.sector = bio->bi_sector;
> ci.idx = bio->bi_idx;
>
> - if (!is_flush) {
> + start_io_acct(ci.io);
> + if (bio->bi_rw & REQ_FLUSH) {
> + ci.bio = &ci.md->flush_bio;
> + ci.sector_count = 0;
> + error = __clone_and_map_empty_flush(&ci);
> + /* dec_pending submits any data associated with flush */
> + } else {
> ci.bio = bio;
> ci.sector_count = bio_sectors(bio);
> - } else {
> - ci.bio = &ci.md->flush_bio;
> - ci.sector_count = 1;
> - }
> -
> - start_io_acct(ci.io);
> - while (ci.sector_count && !error) {
> - if (!is_flush)
> + while (ci.sector_count && !error)
> error = __clone_and_map(&ci);
> - else
> - error = __clone_and_map_flush(&ci);
> }
>
> /* drop the extra reference count */
--
tejun
^ permalink raw reply [flat|nested] 159+ messages in thread* Re: [PATCH 42/41 v2] dm: convey that all flushes are processed as empty
2010-09-08 2:04 ` [PATCH 42/41 v2] " Mike Snitzer
2010-09-08 16:09 ` Tejun Heo
@ 2010-09-08 16:09 ` Tejun Heo
1 sibling, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-08 16:09 UTC (permalink / raw)
To: Mike Snitzer
Cc: Christoph Hellwig, jack, mst, linux-ide,
device-mapper development, James.Bottomley, konishi.ryusuke,
k-ueda, vst, linux-scsi, rusty, linux-raid, mpatocka, swhiteho,
chris.mason, tytso, jaxboe, linux-kernel, linux-fsdevel,
rwheeler, Milan Broz
On 09/08/2010 04:04 AM, Mike Snitzer wrote:
> Rename __clone_and_map_flush to __clone_and_map_empty_flush for added
> clarity.
>
> Simplify logic associated with REQ_FLUSH conditionals.
>
> Introduce a BUG_ON() and add a few more helpful comments to the code
> so that it is clear that all flushes are empty.
>
> Cleanup __split_and_process_bio() so that an empty flush isn't processed
> by a 'sector_count' focused while loop.
>
> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
> ---
> drivers/md/dm.c | 34 +++++++++++++++-------------------
> 1 files changed, 15 insertions(+), 19 deletions(-)
>
> Tejun, please feel free to fold this patch into (or insert after)
> 0025-dm-relax-ordering-of-bio-based-flush-implementation.patch
I added it after 26 and updated flush-fua branch accordingly.
Thank you.
--
tejun
^ permalink raw reply [flat|nested] 159+ messages in thread
* Re: [PATCH 23/41] dm: implement REQ_FLUSH/FUA support for bio-based dm
2010-09-03 10:29 ` Tejun Heo
` (2 preceding siblings ...)
(?)
@ 2010-09-10 18:25 ` Mikulas Patocka
2010-09-10 18:46 ` Mike Snitzer
-1 siblings, 1 reply; 159+ messages in thread
From: Mikulas Patocka @ 2010-09-10 18:25 UTC (permalink / raw)
To: Tejun Heo
Cc: agk, jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda
I quite disagree with the patch. It changes too many things.
What I said and what I want to see:
Take dm code as is. Treat FLUSH requests as empty barriers.
So I want to see a patch that only changes:
bio_empty_barrier(bio) -> bio->bi_rw & REQ_FLUSH
WRITE_BARRIER -> WRITE_FLUSH
etc.
so that the code compiles and works.
DON'T CHANGE ANYTHING ELSE.
Requirements of flushes are subset of requirements of barriers, so if you
send flush and it is treated as a barrier inside DM, there's no problem.
DM code that I wrote only sends out zero-data barriers and already treats
them as flushes (it doesn't rely on ordering), so there's no problem with
sent requests too.
Once fluges get into kernel, I'll clean it up to allow parallel flushes
and requests, etc. But not before. I don't want to work on an interface
that is under development and may be changed.
Mikulas
On Fri, 3 Sep 2010, Tejun Heo wrote:
> This patch converts bio-based dm to support REQ_FLUSH/FUA instead of
> now deprecated REQ_HARDBARRIER.
>
> * -EOPNOTSUPP handling logic dropped.
>
> * Preflush is handled as before but postflush is dropped and replaced
> with passing down REQ_FUA to member request_queues. This replaces
> one array wide cache flush w/ member specific FUA writes.
>
> * __split_and_process_bio() now calls __clone_and_map_flush() directly
> for flushes and guarantees all FLUSH bio's going to targets are zero
> ` length.
>
> * It's now guaranteed that all FLUSH bio's which are passed onto dm
> targets are zero length. bio_empty_barrier() tests are replaced
> with REQ_FLUSH tests.
>
> * Empty WRITE_BARRIERs are replaced with WRITE_FLUSHes.
>
> * Dropped unlikely() around REQ_FLUSH tests. Flushes are not unlikely
> enough to be marked with unlikely().
>
> * Block layer now filters out REQ_FLUSH/FUA bio's if the request_queue
> doesn't support cache flushing. Advertise REQ_FLUSH | REQ_FUA
> capability.
>
> * Request based dm isn't converted yet. dm_init_request_based_queue()
> resets flush support to 0 for now. To avoid disturbing request
> based dm code, dm->flush_error is added for bio based dm while
> requested based dm continues to use dm->barrier_error.
>
> Lightly tested linear, stripe, raid1, snap and crypt targets. Please
> proceed with caution as I'm not familiar with the code base.
>
> Signed-off-by: Tejun Heo <tj@kernel.org>
> Cc: dm-devel@redhat.com
> Cc: Christoph Hellwig <hch@lst.de>
> ---
> drivers/md/dm-crypt.c | 2 +-
> drivers/md/dm-io.c | 20 +-----
> drivers/md/dm-log.c | 2 +-
> drivers/md/dm-raid1.c | 8 +-
> drivers/md/dm-region-hash.c | 16 +++---
> drivers/md/dm-snap-persistent.c | 2 +-
> drivers/md/dm-snap.c | 6 +-
> drivers/md/dm-stripe.c | 2 +-
> drivers/md/dm.c | 119 +++++++++++++++++++--------------------
> 9 files changed, 80 insertions(+), 97 deletions(-)
>
> diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
> index 368e8e9..d5b0e4c 100644
> --- a/drivers/md/dm-crypt.c
> +++ b/drivers/md/dm-crypt.c
> @@ -1278,7 +1278,7 @@ static int crypt_map(struct dm_target *ti, struct bio *bio,
> struct dm_crypt_io *io;
> struct crypt_config *cc;
>
> - if (unlikely(bio_empty_barrier(bio))) {
> + if (bio->bi_rw & REQ_FLUSH) {
> cc = ti->private;
> bio->bi_bdev = cc->dev->bdev;
> return DM_MAPIO_REMAPPED;
> diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
> index 0590c75..136d4f7 100644
> --- a/drivers/md/dm-io.c
> +++ b/drivers/md/dm-io.c
> @@ -31,7 +31,6 @@ struct dm_io_client {
> */
> struct io {
> unsigned long error_bits;
> - unsigned long eopnotsupp_bits;
> atomic_t count;
> struct task_struct *sleeper;
> struct dm_io_client *client;
> @@ -130,11 +129,8 @@ static void retrieve_io_and_region_from_bio(struct bio *bio, struct io **io,
> *---------------------------------------------------------------*/
> static void dec_count(struct io *io, unsigned int region, int error)
> {
> - if (error) {
> + if (error)
> set_bit(region, &io->error_bits);
> - if (error == -EOPNOTSUPP)
> - set_bit(region, &io->eopnotsupp_bits);
> - }
>
> if (atomic_dec_and_test(&io->count)) {
> if (io->sleeper)
> @@ -310,8 +306,8 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where,
> sector_t remaining = where->count;
>
> /*
> - * where->count may be zero if rw holds a write barrier and we
> - * need to send a zero-sized barrier.
> + * where->count may be zero if rw holds a flush and we need to
> + * send a zero-sized flush.
> */
> do {
> /*
> @@ -364,7 +360,7 @@ static void dispatch_io(int rw, unsigned int num_regions,
> */
> for (i = 0; i < num_regions; i++) {
> *dp = old_pages;
> - if (where[i].count || (rw & REQ_HARDBARRIER))
> + if (where[i].count || (rw & REQ_FLUSH))
> do_region(rw, i, where + i, dp, io);
> }
>
> @@ -393,9 +389,7 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions,
> return -EIO;
> }
>
> -retry:
> io->error_bits = 0;
> - io->eopnotsupp_bits = 0;
> atomic_set(&io->count, 1); /* see dispatch_io() */
> io->sleeper = current;
> io->client = client;
> @@ -412,11 +406,6 @@ retry:
> }
> set_current_state(TASK_RUNNING);
>
> - if (io->eopnotsupp_bits && (rw & REQ_HARDBARRIER)) {
> - rw &= ~REQ_HARDBARRIER;
> - goto retry;
> - }
> -
> if (error_bits)
> *error_bits = io->error_bits;
>
> @@ -437,7 +426,6 @@ static int async_io(struct dm_io_client *client, unsigned int num_regions,
>
> io = mempool_alloc(client->pool, GFP_NOIO);
> io->error_bits = 0;
> - io->eopnotsupp_bits = 0;
> atomic_set(&io->count, 1); /* see dispatch_io() */
> io->sleeper = NULL;
> io->client = client;
> diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c
> index 5a08be0..33420e6 100644
> --- a/drivers/md/dm-log.c
> +++ b/drivers/md/dm-log.c
> @@ -300,7 +300,7 @@ static int flush_header(struct log_c *lc)
> .count = 0,
> };
>
> - lc->io_req.bi_rw = WRITE_BARRIER;
> + lc->io_req.bi_rw = WRITE_FLUSH;
>
> return dm_io(&lc->io_req, 1, &null_location, NULL);
> }
> diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
> index 7c081bc..19a59b0 100644
> --- a/drivers/md/dm-raid1.c
> +++ b/drivers/md/dm-raid1.c
> @@ -259,7 +259,7 @@ static int mirror_flush(struct dm_target *ti)
> struct dm_io_region io[ms->nr_mirrors];
> struct mirror *m;
> struct dm_io_request io_req = {
> - .bi_rw = WRITE_BARRIER,
> + .bi_rw = WRITE_FLUSH,
> .mem.type = DM_IO_KMEM,
> .mem.ptr.bvec = NULL,
> .client = ms->io_client,
> @@ -629,7 +629,7 @@ static void do_write(struct mirror_set *ms, struct bio *bio)
> struct dm_io_region io[ms->nr_mirrors], *dest = io;
> struct mirror *m;
> struct dm_io_request io_req = {
> - .bi_rw = WRITE | (bio->bi_rw & WRITE_BARRIER),
> + .bi_rw = WRITE | (bio->bi_rw & WRITE_FLUSH_FUA),
> .mem.type = DM_IO_BVEC,
> .mem.ptr.bvec = bio->bi_io_vec + bio->bi_idx,
> .notify.fn = write_callback,
> @@ -670,7 +670,7 @@ static void do_writes(struct mirror_set *ms, struct bio_list *writes)
> bio_list_init(&requeue);
>
> while ((bio = bio_list_pop(writes))) {
> - if (unlikely(bio_empty_barrier(bio))) {
> + if (bio->bi_rw & REQ_FLUSH) {
> bio_list_add(&sync, bio);
> continue;
> }
> @@ -1203,7 +1203,7 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio,
> * We need to dec pending if this was a write.
> */
> if (rw == WRITE) {
> - if (likely(!bio_empty_barrier(bio)))
> + if (!(bio->bi_rw & REQ_FLUSH))
> dm_rh_dec(ms->rh, map_context->ll);
> return error;
> }
> diff --git a/drivers/md/dm-region-hash.c b/drivers/md/dm-region-hash.c
> index bd5c58b..dad011a 100644
> --- a/drivers/md/dm-region-hash.c
> +++ b/drivers/md/dm-region-hash.c
> @@ -81,9 +81,9 @@ struct dm_region_hash {
> struct list_head failed_recovered_regions;
>
> /*
> - * If there was a barrier failure no regions can be marked clean.
> + * If there was a flush failure no regions can be marked clean.
> */
> - int barrier_failure;
> + int flush_failure;
>
> void *context;
> sector_t target_begin;
> @@ -217,7 +217,7 @@ struct dm_region_hash *dm_region_hash_create(
> INIT_LIST_HEAD(&rh->quiesced_regions);
> INIT_LIST_HEAD(&rh->recovered_regions);
> INIT_LIST_HEAD(&rh->failed_recovered_regions);
> - rh->barrier_failure = 0;
> + rh->flush_failure = 0;
>
> rh->region_pool = mempool_create_kmalloc_pool(MIN_REGIONS,
> sizeof(struct dm_region));
> @@ -399,8 +399,8 @@ void dm_rh_mark_nosync(struct dm_region_hash *rh, struct bio *bio)
> region_t region = dm_rh_bio_to_region(rh, bio);
> int recovering = 0;
>
> - if (bio_empty_barrier(bio)) {
> - rh->barrier_failure = 1;
> + if (bio->bi_rw & REQ_FLUSH) {
> + rh->flush_failure = 1;
> return;
> }
>
> @@ -524,7 +524,7 @@ void dm_rh_inc_pending(struct dm_region_hash *rh, struct bio_list *bios)
> struct bio *bio;
>
> for (bio = bios->head; bio; bio = bio->bi_next) {
> - if (bio_empty_barrier(bio))
> + if (bio->bi_rw & REQ_FLUSH)
> continue;
> rh_inc(rh, dm_rh_bio_to_region(rh, bio));
> }
> @@ -555,9 +555,9 @@ void dm_rh_dec(struct dm_region_hash *rh, region_t region)
> */
>
> /* do nothing for DM_RH_NOSYNC */
> - if (unlikely(rh->barrier_failure)) {
> + if (unlikely(rh->flush_failure)) {
> /*
> - * If a write barrier failed some time ago, we
> + * If a write flush failed some time ago, we
> * don't know whether or not this write made it
> * to the disk, so we must resync the device.
> */
> diff --git a/drivers/md/dm-snap-persistent.c b/drivers/md/dm-snap-persistent.c
> index cc2bdb8..0b61792 100644
> --- a/drivers/md/dm-snap-persistent.c
> +++ b/drivers/md/dm-snap-persistent.c
> @@ -687,7 +687,7 @@ static void persistent_commit_exception(struct dm_exception_store *store,
> /*
> * Commit exceptions to disk.
> */
> - if (ps->valid && area_io(ps, WRITE_BARRIER))
> + if (ps->valid && area_io(ps, WRITE_FLUSH_FUA))
> ps->valid = 0;
>
> /*
> diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
> index 5974d30..eed2101 100644
> --- a/drivers/md/dm-snap.c
> +++ b/drivers/md/dm-snap.c
> @@ -1587,7 +1587,7 @@ static int snapshot_map(struct dm_target *ti, struct bio *bio,
> chunk_t chunk;
> struct dm_snap_pending_exception *pe = NULL;
>
> - if (unlikely(bio_empty_barrier(bio))) {
> + if (bio->bi_rw & REQ_FLUSH) {
> bio->bi_bdev = s->cow->bdev;
> return DM_MAPIO_REMAPPED;
> }
> @@ -1691,7 +1691,7 @@ static int snapshot_merge_map(struct dm_target *ti, struct bio *bio,
> int r = DM_MAPIO_REMAPPED;
> chunk_t chunk;
>
> - if (unlikely(bio_empty_barrier(bio))) {
> + if (bio->bi_rw & REQ_FLUSH) {
> if (!map_context->target_request_nr)
> bio->bi_bdev = s->origin->bdev;
> else
> @@ -2135,7 +2135,7 @@ static int origin_map(struct dm_target *ti, struct bio *bio,
> struct dm_dev *dev = ti->private;
> bio->bi_bdev = dev->bdev;
>
> - if (unlikely(bio_empty_barrier(bio)))
> + if (bio->bi_rw & REQ_FLUSH)
> return DM_MAPIO_REMAPPED;
>
> /* Only tell snapshots if this is a write */
> diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
> index c297f6d..f0371b4 100644
> --- a/drivers/md/dm-stripe.c
> +++ b/drivers/md/dm-stripe.c
> @@ -271,7 +271,7 @@ static int stripe_map(struct dm_target *ti, struct bio *bio,
> uint32_t stripe;
> unsigned target_request_nr;
>
> - if (unlikely(bio_empty_barrier(bio))) {
> + if (bio->bi_rw & REQ_FLUSH) {
> target_request_nr = map_context->target_request_nr;
> BUG_ON(target_request_nr >= sc->stripes);
> bio->bi_bdev = sc->stripe[target_request_nr].dev->bdev;
> diff --git a/drivers/md/dm.c b/drivers/md/dm.c
> index b1d92be..32e6622 100644
> --- a/drivers/md/dm.c
> +++ b/drivers/md/dm.c
> @@ -144,15 +144,16 @@ struct mapped_device {
> spinlock_t deferred_lock;
>
> /*
> - * An error from the barrier request currently being processed.
> + * An error from the flush request currently being processed.
> */
> - int barrier_error;
> + int flush_error;
>
> /*
> * Protect barrier_error from concurrent endio processing
> * in request-based dm.
> */
> spinlock_t barrier_error_lock;
> + int barrier_error;
>
> /*
> * Processing queue (flush/barriers)
> @@ -200,8 +201,8 @@ struct mapped_device {
> /* sysfs handle */
> struct kobject kobj;
>
> - /* zero-length barrier that will be cloned and submitted to targets */
> - struct bio barrier_bio;
> + /* zero-length flush that will be cloned and submitted to targets */
> + struct bio flush_bio;
> };
>
> /*
> @@ -512,7 +513,7 @@ static void end_io_acct(struct dm_io *io)
>
> /*
> * After this is decremented the bio must not be touched if it is
> - * a barrier.
> + * a flush.
> */
> dm_disk(md)->part0.in_flight[rw] = pending =
> atomic_dec_return(&md->pending[rw]);
> @@ -626,7 +627,7 @@ static void dec_pending(struct dm_io *io, int error)
> */
> spin_lock_irqsave(&md->deferred_lock, flags);
> if (__noflush_suspending(md)) {
> - if (!(io->bio->bi_rw & REQ_HARDBARRIER))
> + if (!(io->bio->bi_rw & REQ_FLUSH))
> bio_list_add_head(&md->deferred,
> io->bio);
> } else
> @@ -638,20 +639,14 @@ static void dec_pending(struct dm_io *io, int error)
> io_error = io->error;
> bio = io->bio;
>
> - if (bio->bi_rw & REQ_HARDBARRIER) {
> + if (bio->bi_rw & REQ_FLUSH) {
> /*
> - * There can be just one barrier request so we use
> + * There can be just one flush request so we use
> * a per-device variable for error reporting.
> * Note that you can't touch the bio after end_io_acct
> - *
> - * We ignore -EOPNOTSUPP for empty flush reported by
> - * underlying devices. We assume that if the device
> - * doesn't support empty barriers, it doesn't need
> - * cache flushing commands.
> */
> - if (!md->barrier_error &&
> - !(bio_empty_barrier(bio) && io_error == -EOPNOTSUPP))
> - md->barrier_error = io_error;
> + if (!md->flush_error)
> + md->flush_error = io_error;
> end_io_acct(io);
> free_io(md, io);
> } else {
> @@ -1119,7 +1114,7 @@ static void dm_bio_destructor(struct bio *bio)
> }
>
> /*
> - * Creates a little bio that is just does part of a bvec.
> + * Creates a little bio that just does part of a bvec.
> */
> static struct bio *split_bvec(struct bio *bio, sector_t sector,
> unsigned short idx, unsigned int offset,
> @@ -1134,7 +1129,7 @@ static struct bio *split_bvec(struct bio *bio, sector_t sector,
>
> clone->bi_sector = sector;
> clone->bi_bdev = bio->bi_bdev;
> - clone->bi_rw = bio->bi_rw & ~REQ_HARDBARRIER;
> + clone->bi_rw = bio->bi_rw;
> clone->bi_vcnt = 1;
> clone->bi_size = to_bytes(len);
> clone->bi_io_vec->bv_offset = offset;
> @@ -1161,7 +1156,6 @@ static struct bio *clone_bio(struct bio *bio, sector_t sector,
>
> clone = bio_alloc_bioset(GFP_NOIO, bio->bi_max_vecs, bs);
> __bio_clone(clone, bio);
> - clone->bi_rw &= ~REQ_HARDBARRIER;
> clone->bi_destructor = dm_bio_destructor;
> clone->bi_sector = sector;
> clone->bi_idx = idx;
> @@ -1225,7 +1219,7 @@ static void __issue_target_requests(struct clone_info *ci, struct dm_target *ti,
> __issue_target_request(ci, ti, request_nr, len);
> }
>
> -static int __clone_and_map_empty_barrier(struct clone_info *ci)
> +static int __clone_and_map_flush(struct clone_info *ci)
> {
> unsigned target_nr = 0;
> struct dm_target *ti;
> @@ -1289,9 +1283,6 @@ static int __clone_and_map(struct clone_info *ci)
> sector_t len = 0, max;
> struct dm_target_io *tio;
>
> - if (unlikely(bio_empty_barrier(bio)))
> - return __clone_and_map_empty_barrier(ci);
> -
> if (unlikely(bio->bi_rw & REQ_DISCARD))
> return __clone_and_map_discard(ci);
>
> @@ -1383,11 +1374,11 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
>
> ci.map = dm_get_live_table(md);
> if (unlikely(!ci.map)) {
> - if (!(bio->bi_rw & REQ_HARDBARRIER))
> + if (!(bio->bi_rw & REQ_FLUSH))
> bio_io_error(bio);
> else
> - if (!md->barrier_error)
> - md->barrier_error = -EIO;
> + if (!md->flush_error)
> + md->flush_error = -EIO;
> return;
> }
>
> @@ -1400,14 +1391,22 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
> ci.io->md = md;
> spin_lock_init(&ci.io->endio_lock);
> ci.sector = bio->bi_sector;
> - ci.sector_count = bio_sectors(bio);
> - if (unlikely(bio_empty_barrier(bio)))
> + if (!(bio->bi_rw & REQ_FLUSH))
> + ci.sector_count = bio_sectors(bio);
> + else {
> + /* all FLUSH bio's reaching here should be empty */
> + WARN_ON_ONCE(bio_has_data(bio));
> ci.sector_count = 1;
> + }
> ci.idx = bio->bi_idx;
>
> start_io_acct(ci.io);
> - while (ci.sector_count && !error)
> - error = __clone_and_map(&ci);
> + while (ci.sector_count && !error) {
> + if (!(bio->bi_rw & REQ_FLUSH))
> + error = __clone_and_map(&ci);
> + else
> + error = __clone_and_map_flush(&ci);
> + }
>
> /* drop the extra reference count */
> dec_pending(ci.io, error);
> @@ -1492,11 +1491,11 @@ static int _dm_request(struct request_queue *q, struct bio *bio)
> part_stat_unlock();
>
> /*
> - * If we're suspended or the thread is processing barriers
> + * If we're suspended or the thread is processing flushes
> * we have to queue this io for later.
> */
> if (unlikely(test_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags)) ||
> - unlikely(bio->bi_rw & REQ_HARDBARRIER)) {
> + (bio->bi_rw & REQ_FLUSH)) {
> up_read(&md->io_lock);
>
> if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) &&
> @@ -1940,6 +1939,7 @@ static void dm_init_md_queue(struct mapped_device *md)
> blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY);
> md->queue->unplug_fn = dm_unplug_all;
> blk_queue_merge_bvec(md->queue, dm_merge_bvec);
> + blk_queue_flush(md->queue, REQ_FLUSH | REQ_FUA);
> }
>
> /*
> @@ -2245,7 +2245,8 @@ static int dm_init_request_based_queue(struct mapped_device *md)
> blk_queue_softirq_done(md->queue, dm_softirq_done);
> blk_queue_prep_rq(md->queue, dm_prep_fn);
> blk_queue_lld_busy(md->queue, dm_lld_busy);
> - blk_queue_flush(md->queue, REQ_FLUSH);
> + /* no flush support for request based dm yet */
> + blk_queue_flush(md->queue, 0);
>
> elv_register_queue(md->queue);
>
> @@ -2406,41 +2407,35 @@ static int dm_wait_for_completion(struct mapped_device *md, int interruptible)
> return r;
> }
>
> -static void dm_flush(struct mapped_device *md)
> +static void process_flush(struct mapped_device *md, struct bio *bio)
> {
> - dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
> -
> - bio_init(&md->barrier_bio);
> - md->barrier_bio.bi_bdev = md->bdev;
> - md->barrier_bio.bi_rw = WRITE_BARRIER;
> - __split_and_process_bio(md, &md->barrier_bio);
> + md->flush_error = 0;
>
> + /* handle REQ_FLUSH */
> dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
> -}
>
> -static void process_barrier(struct mapped_device *md, struct bio *bio)
> -{
> - md->barrier_error = 0;
> + bio_init(&md->flush_bio);
> + md->flush_bio.bi_bdev = md->bdev;
> + md->flush_bio.bi_rw = WRITE_FLUSH;
> + __split_and_process_bio(md, &md->flush_bio);
>
> - dm_flush(md);
> + dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
>
> - if (!bio_empty_barrier(bio)) {
> - __split_and_process_bio(md, bio);
> - /*
> - * If the request isn't supported, don't waste time with
> - * the second flush.
> - */
> - if (md->barrier_error != -EOPNOTSUPP)
> - dm_flush(md);
> + /* if it's an empty flush or the preflush failed, we're done */
> + if (!bio_has_data(bio) || md->flush_error) {
> + if (md->flush_error != DM_ENDIO_REQUEUE)
> + bio_endio(bio, md->flush_error);
> + else {
> + spin_lock_irq(&md->deferred_lock);
> + bio_list_add_head(&md->deferred, bio);
> + spin_unlock_irq(&md->deferred_lock);
> + }
> + return;
> }
>
> - if (md->barrier_error != DM_ENDIO_REQUEUE)
> - bio_endio(bio, md->barrier_error);
> - else {
> - spin_lock_irq(&md->deferred_lock);
> - bio_list_add_head(&md->deferred, bio);
> - spin_unlock_irq(&md->deferred_lock);
> - }
> + /* issue data + REQ_FUA */
> + bio->bi_rw &= ~REQ_FLUSH;
> + __split_and_process_bio(md, bio);
> }
>
> /*
> @@ -2469,8 +2464,8 @@ static void dm_wq_work(struct work_struct *work)
> if (dm_request_based(md))
> generic_make_request(c);
> else {
> - if (c->bi_rw & REQ_HARDBARRIER)
> - process_barrier(md, c);
> + if (c->bi_rw & REQ_FLUSH)
> + process_flush(md, c);
> else
> __split_and_process_bio(md, c);
> }
> --
> 1.7.1
>
^ permalink raw reply [flat|nested] 159+ messages in thread* Re: [PATCH 23/41] dm: implement REQ_FLUSH/FUA support for bio-based dm
2010-09-10 18:25 ` [PATCH 23/41] dm: implement REQ_FLUSH/FUA support for bio-based dm Mikulas Patocka
@ 2010-09-10 18:46 ` Mike Snitzer
2010-09-10 19:05 ` Mikulas Patocka
0 siblings, 1 reply; 159+ messages in thread
From: Mike Snitzer @ 2010-09-10 18:46 UTC (permalink / raw)
To: Mikulas Patocka
Cc: Tejun Heo, agk, jaxboe, linux-kernel, linux-fsdevel, linux-scsi,
linux-ide, linux-raid, dm-devel, hch, konishi.ryusuke,
James.Bottomley, tytso, chris.mason, swhiteho, vst, jack,
rwheeler, hare, neilb, rusty, mst, k-ueda
On Fri, Sep 10 2010 at 2:25pm -0400,
Mikulas Patocka <mpatocka@redhat.com> wrote:
> I quite disagree with the patch. It changes too many things.
>
> What I said and what I want to see:
>
> Take dm code as is. Treat FLUSH requests as empty barriers.
>
>
> So I want to see a patch that only changes:
>
> bio_empty_barrier(bio) -> bio->bi_rw & REQ_FLUSH
> WRITE_BARRIER -> WRITE_FLUSH
> etc.
>
> so that the code compiles and works.
>
> DON'T CHANGE ANYTHING ELSE.
>
> Requirements of flushes are subset of requirements of barriers, so if you
> send flush and it is treated as a barrier inside DM, there's no problem.
> DM code that I wrote only sends out zero-data barriers and already treats
> them as flushes (it doesn't rely on ordering), so there's no problem with
> sent requests too.
>
> Once fluges get into kernel, I'll clean it up to allow parallel flushes
> and requests, etc. But not before. I don't want to work on an interface
> that is under development and may be changed.
Mikulas,
I agree that it is unfortunate that we're having to explore this level
of change to DM's flush support. Especially given how recently your
barrier code was added.
But the work has already been done. Rather than putting up artificial
barriers (no pun intended) it'd be great if you took the time to just
review the changes.
The patch header enumerates and describes the various changes quite
clearly.
And in fact, this first patch basically is as minimal as it gets
relative to bio-based DM's conversion to FLUSH+FUA.
Please direct your energy and talent in a positive way rather than
starting a potential flame.
Thanks,
Mike
^ permalink raw reply [flat|nested] 159+ messages in thread
* Re: [PATCH 23/41] dm: implement REQ_FLUSH/FUA support for bio-based dm
2010-09-10 18:46 ` Mike Snitzer
@ 2010-09-10 19:05 ` Mikulas Patocka
2010-09-10 19:24 ` Mike Snitzer
0 siblings, 1 reply; 159+ messages in thread
From: Mikulas Patocka @ 2010-09-10 19:05 UTC (permalink / raw)
To: Mike Snitzer
Cc: Tejun Heo, agk, jaxboe, linux-kernel, linux-fsdevel, linux-scsi,
linux-ide, linux-raid, dm-devel, hch, konishi.ryusuke,
James.Bottomley, tytso, chris.mason, swhiteho, vst, jack,
rwheeler, hare, neilb, rusty, mst, k-ueda
On Fri, 10 Sep 2010, Mike Snitzer wrote:
> On Fri, Sep 10 2010 at 2:25pm -0400,
> Mikulas Patocka <mpatocka@redhat.com> wrote:
>
> > I quite disagree with the patch. It changes too many things.
> >
> > What I said and what I want to see:
> >
> > Take dm code as is. Treat FLUSH requests as empty barriers.
> >
> >
> > So I want to see a patch that only changes:
> >
> > bio_empty_barrier(bio) -> bio->bi_rw & REQ_FLUSH
> > WRITE_BARRIER -> WRITE_FLUSH
> > etc.
> >
> > so that the code compiles and works.
> >
> > DON'T CHANGE ANYTHING ELSE.
> >
> > Requirements of flushes are subset of requirements of barriers, so if you
> > send flush and it is treated as a barrier inside DM, there's no problem.
> > DM code that I wrote only sends out zero-data barriers and already treats
> > them as flushes (it doesn't rely on ordering), so there's no problem with
> > sent requests too.
> >
> > Once fluges get into kernel, I'll clean it up to allow parallel flushes
> > and requests, etc. But not before. I don't want to work on an interface
> > that is under development and may be changed.
>
> Mikulas,
>
> I agree that it is unfortunate that we're having to explore this level
> of change to DM's flush support. Especially given how recently your
> barrier code was added.
>
> But the work has already been done. Rather than putting up artificial
> barriers (no pun intended) it'd be great if you took the time to just
> review the changes.
>
> The patch header enumerates and describes the various changes quite
> clearly.
>
> And in fact, this first patch basically is as minimal as it gets
> relative to bio-based DM's conversion to FLUSH+FUA.
>
> Please direct your energy and talent in a positive way rather than
> starting a potential flame.
>
> Thanks,
> Mike
I don't want to flame. I mean this:
* person X writes a patch P.
* person Y reads P, sees that the condition C is true and writes patch Q
that dependes on condition C.
* person X changes a patch P, so that the patch is correct but condition C
is no longer true.
Now, there is a bug in the patch Q and NEITHER X NOR Y can find out about
that bug.
That's why parallel development doesn't work.
If you develop on things in the kernel, it is different.
* person X writes a patch P and puts it in the kernel.
* person Y reads the kernel code, sees that the condition C is true and
writes a patch Q that assumes that the condition C is true. He puts this
patch to the kernel too.
* person X wants to change his code so that the condition C isn't true,
but it is now his responsibility to search the rest of the kernel to see
if it depends on the condition C. He searches the code and finds Q.
This is not a flamewar, just a technical explanation, why I don't want to
develop on interfaces that are not in the kernel.
Mikulas
^ permalink raw reply [flat|nested] 159+ messages in thread
* Re: [PATCH 23/41] dm: implement REQ_FLUSH/FUA support for bio-based dm
2010-09-10 19:05 ` Mikulas Patocka
@ 2010-09-10 19:24 ` Mike Snitzer
2010-09-10 20:06 ` Mikulas Patocka
0 siblings, 1 reply; 159+ messages in thread
From: Mike Snitzer @ 2010-09-10 19:24 UTC (permalink / raw)
To: Mikulas Patocka
Cc: Tejun Heo, agk, jaxboe, linux-kernel, linux-fsdevel, linux-scsi,
linux-ide, linux-raid, dm-devel, hch, konishi.ryusuke,
James.Bottomley, tytso, chris.mason, swhiteho, vst, jack,
rwheeler, hare, neilb, rusty, mst, k-ueda
On Fri, Sep 10 2010 at 3:05pm -0400,
Mikulas Patocka <mpatocka@redhat.com> wrote:
>
>
> On Fri, 10 Sep 2010, Mike Snitzer wrote:
> > And in fact, this first patch basically is as minimal as it gets
> > relative to bio-based DM's conversion to FLUSH+FUA.
> >
> > Please direct your energy and talent in a positive way rather than
> > starting a potential flame.
> >
> > Thanks,
> > Mike
>
> I don't want to flame. I mean this:
>
> * person X writes a patch P.
> * person Y reads P, sees that the condition C is true and writes patch Q
> that dependes on condition C.
> * person X changes a patch P, so that the patch is correct but condition C
> is no longer true.
>
> Now, there is a bug in the patch Q and NEITHER X NOR Y can find out about
> that bug.
>
> That's why parallel development doesn't work.
>
> If you develop on things in the kernel, it is different.
> * person X writes a patch P and puts it in the kernel.
> * person Y reads the kernel code, sees that the condition C is true and
> writes a patch Q that assumes that the condition C is true. He puts this
> patch to the kernel too.
> * person X wants to change his code so that the condition C isn't true,
> but it is now his responsibility to search the rest of the kernel to see
> if it depends on the condition C. He searches the code and finds Q.
>
> This is not a flamewar, just a technical explanation, why I don't want to
> develop on interfaces that are not in the kernel.
We're reasonable people and can certainly prevent a flamewar but what
you're doing is an elaborate distraction. The energy it took you to
write and reason through your logic above could've been used to just
review the DM FLUSH+FUA patches.
The various interfaces are hardened now and staged for inclussion in
2.6.37. Jens has already pulled the entire 40+ patchset into his
for-next branch for wider linux-next testing.
Tejun, Christoph and others have done an amazing job with this
conversion. The fact that Tejun tackled the heavy lifting of DM's
conversion was unexpected but 100% appreciated (by me and I assume
others). Please don't dismiss, or misrepresent the status of, this
FLUSH+FUA work.
Mike
^ permalink raw reply [flat|nested] 159+ messages in thread
* Re: [PATCH 23/41] dm: implement REQ_FLUSH/FUA support for bio-based dm
2010-09-10 19:24 ` Mike Snitzer
@ 2010-09-10 20:06 ` Mikulas Patocka
2010-09-10 23:36 ` Tejun Heo
0 siblings, 1 reply; 159+ messages in thread
From: Mikulas Patocka @ 2010-09-10 20:06 UTC (permalink / raw)
To: Mike Snitzer
Cc: Tejun Heo, agk, jaxboe, linux-kernel, linux-fsdevel, linux-scsi,
linux-ide, linux-raid, dm-devel, hch, konishi.ryusuke,
James.Bottomley, tytso, chris.mason, swhiteho, vst, jack,
rwheeler, hare, neilb, rusty, mst, k-ueda
On Fri, 10 Sep 2010, Mike Snitzer wrote:
> On Fri, Sep 10 2010 at 3:05pm -0400,
> Mikulas Patocka <mpatocka@redhat.com> wrote:
>
> >
> >
> > On Fri, 10 Sep 2010, Mike Snitzer wrote:
> > > And in fact, this first patch basically is as minimal as it gets
> > > relative to bio-based DM's conversion to FLUSH+FUA.
> > >
> > > Please direct your energy and talent in a positive way rather than
> > > starting a potential flame.
> > >
> > > Thanks,
> > > Mike
> >
> > I don't want to flame. I mean this:
> >
> > * person X writes a patch P.
> > * person Y reads P, sees that the condition C is true and writes patch Q
> > that dependes on condition C.
> > * person X changes a patch P, so that the patch is correct but condition C
> > is no longer true.
> >
> > Now, there is a bug in the patch Q and NEITHER X NOR Y can find out about
> > that bug.
> >
> > That's why parallel development doesn't work.
> >
> > If you develop on things in the kernel, it is different.
> > * person X writes a patch P and puts it in the kernel.
> > * person Y reads the kernel code, sees that the condition C is true and
> > writes a patch Q that assumes that the condition C is true. He puts this
> > patch to the kernel too.
> > * person X wants to change his code so that the condition C isn't true,
> > but it is now his responsibility to search the rest of the kernel to see
> > if it depends on the condition C. He searches the code and finds Q.
> >
> > This is not a flamewar, just a technical explanation, why I don't want to
> > develop on interfaces that are not in the kernel.
>
> We're reasonable people and can certainly prevent a flamewar but what
> you're doing is an elaborate distraction. The energy it took you to
> write and reason through your logic above could've been used to just
> review the DM FLUSH+FUA patches.
No. If I reviewed 40 patches perfectly, I would take long long time (the
previous 2-line patch that I reviewed took me a week to review --- but I
found a flaw that the other people who reviewed it quickly didn't find).
So I reviewed only "dm" patch and found out that it is too big.
Make a smaller patch with barrier -> FLUSH logic only. And then you can
make additional patches with function/variable renames or logic changes.
> The various interfaces are hardened now and staged for inclussion in
> 2.6.37. Jens has already pulled the entire 40+ patchset into his
> for-next branch for wider linux-next testing.
>
> Tejun, Christoph and others have done an amazing job with this
> conversion. The fact that Tejun tackled the heavy lifting of DM's
> conversion was unexpected but 100% appreciated (by me and I assume
> others). Please don't dismiss, or misrepresent the status of, this
> FLUSH+FUA work.
I am not dismissing anything. I agree with barrier -> flush change. It
simplifies things a lot.
But I have my work rules that I learned: I use no git kernels and no
external patches (except Alasdair's patchset that I want to test). I only
use -rc or final kernels. I need a stable computer --- I don't want to
solve problems like "does it crash because I pulled something or does it
crash because I made a bug in my code?" So, put that into 2.6.37-rc1 and
I'll optimize flushes in dm for -rc2 or -rc3.
Mikulas
^ permalink raw reply [flat|nested] 159+ messages in thread
* Re: [PATCH 23/41] dm: implement REQ_FLUSH/FUA support for bio-based dm
2010-09-10 20:06 ` Mikulas Patocka
@ 2010-09-10 23:36 ` Tejun Heo
2010-09-11 1:46 ` Mike Snitzer
` (2 more replies)
0 siblings, 3 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-10 23:36 UTC (permalink / raw)
To: Mikulas Patocka
Cc: Mike Snitzer, agk, jaxboe, linux-kernel, linux-fsdevel,
linux-scsi, linux-ide, linux-raid, dm-devel, hch,
konishi.ryusuke, James.Bottomley, tytso, chris.mason, swhiteho,
vst, jack, rwheeler, hare, neilb, rusty, mst, k-ueda
On 09/10/2010 10:06 PM, Mikulas Patocka wrote:
> But I have my work rules that I learned: I use no git kernels and no
> external patches (except Alasdair's patchset that I want to test). I only
> use -rc or final kernels. I need a stable computer --- I don't want to
> solve problems like "does it crash because I pulled something or does it
> crash because I made a bug in my code?" So, put that into 2.6.37-rc1 and
> I'll optimize flushes in dm for -rc2 or -rc3.
Alright, I'm sorry but this is as far as I would go for dm conversion
patches. If you wanna split it further or do it your way, please feel
free to. I think it would be beneficial to do things now but, hey,
you guys are maintaining dm part of the kernel, so it's up to you
guys. But, I think it would be silly for everyone else to wait for
the rather special requirement for dm, so if we have to go forward
without dm updates, I suppose we will have to. Jens, please feel free
to drop dm conversion patches.
Thanks.
--
tejun
^ permalink raw reply [flat|nested] 159+ messages in thread* Re: [PATCH 23/41] dm: implement REQ_FLUSH/FUA support for bio-based dm
2010-09-10 23:36 ` Tejun Heo
@ 2010-09-11 1:46 ` Mike Snitzer
[not found] ` <Pine.LNX.4.64.1009110500070.27949@hs20-bc2-1.build.redhat.com>
2010-09-18 17:58 ` Bill Davidsen
2010-09-11 12:19 ` Ric Wheeler
2010-09-13 19:01 ` Mikulas Patocka
2 siblings, 2 replies; 159+ messages in thread
From: Mike Snitzer @ 2010-09-11 1:46 UTC (permalink / raw)
To: Tejun Heo
Cc: Mikulas Patocka, agk, jaxboe, linux-kernel, linux-fsdevel,
linux-scsi, linux-ide, linux-raid, dm-devel, hch,
konishi.ryusuke, James.Bottomley, tytso, chris.mason, swhiteho,
vst, jack, rwheeler, hare, neilb, rusty, mst, k-ueda
On Fri, Sep 10 2010 at 7:36pm -0400,
Tejun Heo <tj@kernel.org> wrote:
> On 09/10/2010 10:06 PM, Mikulas Patocka wrote:
> > But I have my work rules that I learned: I use no git kernels and no
> > external patches (except Alasdair's patchset that I want to test). I only
> > use -rc or final kernels. I need a stable computer --- I don't want to
> > solve problems like "does it crash because I pulled something or does it
> > crash because I made a bug in my code?" So, put that into 2.6.37-rc1 and
> > I'll optimize flushes in dm for -rc2 or -rc3.
>
> Alright, I'm sorry but this is as far as I would go for dm conversion
> patches. If you wanna split it further or do it your way, please feel
> free to. I think it would be beneficial to do things now but, hey,
> you guys are maintaining dm part of the kernel, so it's up to you
> guys. But, I think it would be silly for everyone else to wait for
> the rather special requirement for dm, so if we have to go forward
> without dm updates, I suppose we will have to. Jens, please feel free
> to drop dm conversion patches.
Tejun,
Mikulas doesn't speak for Alasdair or the rest of the DM developers. He
speaks for himself. He, like me, is a member of the team that helps
maintain DM. But Alasdair is the upstream DM maintainer.
Please don't latch on to Mikulas' disruptive stone-walling. As I shared
in my previous reply: your FLUSH+FUA contributions to DM are very much
appreciated! Kiyoshi, Jun'ichi and myself have all worked with you
effectively and so far the end result DM conversion has proven quite
stable and correct. Wider testing via linux-next is an important next
step.
Jens, please don't drop the DM FLUSH+FUA conversion patches from your
'for-next' branch. Mikulas has yet to offer a single substantive
criticism of the code in question.
Alasdair, please advise ASAP.
Thanks,
Mike
^ permalink raw reply [flat|nested] 159+ messages in thread[parent not found: <Pine.LNX.4.64.1009110500070.27949@hs20-bc2-1.build.redhat.com>]
* Re: [PATCH 23/41] dm: implement REQ_FLUSH/FUA support for bio-based dm
2010-09-11 1:46 ` Mike Snitzer
[not found] ` <Pine.LNX.4.64.1009110500070.27949@hs20-bc2-1.build.redhat.com>
@ 2010-09-18 17:58 ` Bill Davidsen
2010-09-18 20:42 ` [dm-devel] " Mike Snitzer
1 sibling, 1 reply; 159+ messages in thread
From: Bill Davidsen @ 2010-09-18 17:58 UTC (permalink / raw)
To: Mike Snitzer
Cc: jack, mst, linux-ide, dm-devel, James.Bottomley, konishi.ryusuke,
hch, agk, k-ueda, vst, linux-scsi, rusty, linux-raid, Tejun Heo,
Mikulas Patocka, swhiteho, chris.mason, tytso, jaxboe,
linux-kernel, linux-fsdevel, rwheeler
[-- Attachment #1.1: Type: text/plain, Size: 2725 bytes --]
Mike Snitzer wrote:
> On Fri, Sep 10 2010 at 7:36pm -0400,
> Tejun Heo<tj@kernel.org> wrote:
>
>
>> On 09/10/2010 10:06 PM, Mikulas Patocka wrote:
>>
>>> But I have my work rules that I learned: I use no git kernels and no
>>> external patches (except Alasdair's patchset that I want to test). I only
>>> use -rc or final kernels. I need a stable computer --- I don't want to
>>> solve problems like "does it crash because I pulled something or does it
>>> crash because I made a bug in my code?" So, put that into 2.6.37-rc1 and
>>> I'll optimize flushes in dm for -rc2 or -rc3.
>>>
>> Alright, I'm sorry but this is as far as I would go for dm conversion
>> patches. If you wanna split it further or do it your way, please feel
>> free to. I think it would be beneficial to do things now but, hey,
>> you guys are maintaining dm part of the kernel, so it's up to you
>> guys. But, I think it would be silly for everyone else to wait for
>> the rather special requirement for dm, so if we have to go forward
>> without dm updates, I suppose we will have to. Jens, please feel free
>> to drop dm conversion patches.
>>
> Tejun,
>
> Mikulas doesn't speak for Alasdair or the rest of the DM developers. He
> speaks for himself. He, like me, is a member of the team that helps
> maintain DM. But Alasdair is the upstream DM maintainer.
>
> Please don't latch on to Mikulas' disruptive stone-walling. As I shared
> in my previous reply: your FLUSH+FUA contributions to DM are very much
> appreciated! Kiyoshi, Jun'ichi and myself have all worked with you
> effectively and so far the end result DM conversion has proven quite
> stable and correct. Wider testing via linux-next is an important next
> step.
>
> Jens, please don't drop the DM FLUSH+FUA conversion patches from your
> 'for-next' branch. Mikulas has yet to offer a single substantive
> criticism of the code in question.
>
He is commenting on the process rather than the code, since he tells you
that he lacks time to review your complex changes to his work, so your
saying that he hasn't found errors in it is muddy thinking as best.
He provided a patch and would like it tested properly before you drop a
bunch of stuff on top of it, to be sure it gets proper exposure and
wider testing. That sounds like sound software development to me. It
sounds as though you feel that the inclusion of your additional work is
critical and can't possibly wait until the next -rc or release, and I
have missed the reason why your stuff can't wait until it can drop on
mainline code..
--
Bill Davidsen<davidsen@tmr.com>
"We can't solve today's problems by using the same thinking we
used in creating them." - Einstein
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^ permalink raw reply [flat|nested] 159+ messages in thread* Re: [dm-devel] [PATCH 23/41] dm: implement REQ_FLUSH/FUA support for bio-based dm
2010-09-18 17:58 ` Bill Davidsen
@ 2010-09-18 20:42 ` Mike Snitzer
0 siblings, 0 replies; 159+ messages in thread
From: Mike Snitzer @ 2010-09-18 20:42 UTC (permalink / raw)
To: Bill Davidsen
Cc: jack, mst, linux-ide, James.Bottomley, konishi.ryusuke, hch, agk,
k-ueda, vst, linux-scsi, rusty, linux-raid, Tejun Heo,
Mikulas Patocka, swhiteho, chris.mason, tytso, jaxboe,
linux-kernel, linux-fsdevel, rwheeler, dm-devel
On Sat, Sep 18, 2010 at 1:58 PM, Bill Davidsen <davidsen@tmr.com> wrote:
>
> He is commenting on the process rather than the code, since he tells you
> that he lacks time to review your complex changes to his work, so your
> saying that he hasn't found errors in it is muddy thinking as best.
>
> He provided a patch and would like it tested properly before you drop a
> bunch of stuff on top of it, to be sure it gets proper exposure and wider
> testing. That sounds like sound software development to me. It sounds as
> though you feel that the inclusion of your additional work is critical and
> can't possibly wait until the next -rc or release, and I have missed the
> reason why your stuff can't wait until it can drop on mainline code..
Well that was just completely incoherent yet clearly antagonistic drivel.
Seems you're joining multiple peoples' response to this issue and
attributing that completely misinformed combination to "he".
Thanks but we have this completely under control.
Mike
^ permalink raw reply [flat|nested] 159+ messages in thread
* Re: [PATCH 23/41] dm: implement REQ_FLUSH/FUA support for bio-based dm
2010-09-10 23:36 ` Tejun Heo
2010-09-11 1:46 ` Mike Snitzer
@ 2010-09-11 12:19 ` Ric Wheeler
2010-09-13 19:01 ` Mikulas Patocka
2 siblings, 0 replies; 159+ messages in thread
From: Ric Wheeler @ 2010-09-11 12:19 UTC (permalink / raw)
To: Tejun Heo
Cc: Mikulas Patocka, Mike Snitzer, agk, jaxboe, linux-kernel,
linux-fsdevel, linux-scsi, linux-ide, linux-raid, dm-devel, hch,
konishi.ryusuke, James.Bottomley, tytso, chris.mason, swhiteho,
vst, jack, hare, neilb, rusty, mst, k-ueda
On 09/10/2010 07:36 PM, Tejun Heo wrote:
> On 09/10/2010 10:06 PM, Mikulas Patocka wrote:
>> But I have my work rules that I learned: I use no git kernels and no
>> external patches (except Alasdair's patchset that I want to test). I only
>> use -rc or final kernels. I need a stable computer --- I don't want to
>> solve problems like "does it crash because I pulled something or does it
>> crash because I made a bug in my code?" So, put that into 2.6.37-rc1 and
>> I'll optimize flushes in dm for -rc2 or -rc3.
> Alright, I'm sorry but this is as far as I would go for dm conversion
> patches. If you wanna split it further or do it your way, please feel
> free to. I think it would be beneficial to do things now but, hey,
> you guys are maintaining dm part of the kernel, so it's up to you
> guys. But, I think it would be silly for everyone else to wait for
> the rather special requirement for dm, so if we have to go forward
> without dm updates, I suppose we will have to. Jens, please feel free
> to drop dm conversion patches.
>
> Thanks.
>
I think that we certainly want to continue to fix the whole path - including dm
- so we do not end up with the fragmented set of works here/doesn't work there
situation we had for several years. If Mikulas has better patches, he should
post them for review.
Thanks!
Ric
^ permalink raw reply [flat|nested] 159+ messages in thread
* Re: [PATCH 23/41] dm: implement REQ_FLUSH/FUA support for bio-based dm
2010-09-10 23:36 ` Tejun Heo
2010-09-11 1:46 ` Mike Snitzer
2010-09-11 12:19 ` Ric Wheeler
@ 2010-09-13 19:01 ` Mikulas Patocka
2 siblings, 0 replies; 159+ messages in thread
From: Mikulas Patocka @ 2010-09-13 19:01 UTC (permalink / raw)
To: Tejun Heo
Cc: Mike Snitzer, agk, jaxboe, linux-kernel, linux-fsdevel,
linux-scsi, linux-ide, linux-raid, dm-devel, hch,
konishi.ryusuke, James.Bottomley, tytso, chris.mason, swhiteho,
vst, jack, rwheeler, hare, neilb, rusty, mst, k-ueda
On Sat, 11 Sep 2010, Tejun Heo wrote:
> On 09/10/2010 10:06 PM, Mikulas Patocka wrote:
> > But I have my work rules that I learned: I use no git kernels and no
> > external patches (except Alasdair's patchset that I want to test). I only
> > use -rc or final kernels. I need a stable computer --- I don't want to
> > solve problems like "does it crash because I pulled something or does it
> > crash because I made a bug in my code?" So, put that into 2.6.37-rc1 and
> > I'll optimize flushes in dm for -rc2 or -rc3.
>
> Alright, I'm sorry but this is as far as I would go for dm conversion
> patches. If you wanna split it further or do it your way, please feel
> free to. I think it would be beneficial to do things now but, hey,
> you guys are maintaining dm part of the kernel, so it's up to you
> guys. But, I think it would be silly for everyone else to wait for
> the rather special requirement for dm, so if we have to go forward
> without dm updates, I suppose we will have to. Jens, please feel free
> to drop dm conversion patches.
>
> Thanks.
> --
> tejun
I think: take the first patch and submit it on your own, and send the rest
of patches to Alasdair to his tree. If I get such big patches I am unable
to immediatelly say if they are correct or not.
Mikulas
^ permalink raw reply [flat|nested] 159+ messages in thread
* [PATCH 23/41] dm: implement REQ_FLUSH/FUA support for bio-based dm
2010-09-03 10:29 ` Tejun Heo
` (32 preceding siblings ...)
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
This patch converts bio-based dm to support REQ_FLUSH/FUA instead of
now deprecated REQ_HARDBARRIER.
* -EOPNOTSUPP handling logic dropped.
* Preflush is handled as before but postflush is dropped and replaced
with passing down REQ_FUA to member request_queues. This replaces
one array wide cache flush w/ member specific FUA writes.
* __split_and_process_bio() now calls __clone_and_map_flush() directly
for flushes and guarantees all FLUSH bio's going to targets are zero
` length.
* It's now guaranteed that all FLUSH bio's which are passed onto dm
targets are zero length. bio_empty_barrier() tests are replaced
with REQ_FLUSH tests.
* Empty WRITE_BARRIERs are replaced with WRITE_FLUSHes.
* Dropped unlikely() around REQ_FLUSH tests. Flushes are not unlikely
enough to be marked with unlikely().
* Block layer now filters out REQ_FLUSH/FUA bio's if the request_queue
doesn't support cache flushing. Advertise REQ_FLUSH | REQ_FUA
capability.
* Request based dm isn't converted yet. dm_init_request_based_queue()
resets flush support to 0 for now. To avoid disturbing request
based dm code, dm->flush_error is added for bio based dm while
requested based dm continues to use dm->barrier_error.
Lightly tested linear, stripe, raid1, snap and crypt targets. Please
proceed with caution as I'm not familiar with the code base.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: dm-devel@redhat.com
Cc: Christoph Hellwig <hch@lst.de>
---
drivers/md/dm-crypt.c | 2 +-
drivers/md/dm-io.c | 20 +-----
drivers/md/dm-log.c | 2 +-
drivers/md/dm-raid1.c | 8 +-
drivers/md/dm-region-hash.c | 16 +++---
drivers/md/dm-snap-persistent.c | 2 +-
drivers/md/dm-snap.c | 6 +-
drivers/md/dm-stripe.c | 2 +-
drivers/md/dm.c | 119 +++++++++++++++++++--------------------
9 files changed, 80 insertions(+), 97 deletions(-)
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 368e8e9..d5b0e4c 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1278,7 +1278,7 @@ static int crypt_map(struct dm_target *ti, struct bio *bio,
struct dm_crypt_io *io;
struct crypt_config *cc;
- if (unlikely(bio_empty_barrier(bio))) {
+ if (bio->bi_rw & REQ_FLUSH) {
cc = ti->private;
bio->bi_bdev = cc->dev->bdev;
return DM_MAPIO_REMAPPED;
diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index 0590c75..136d4f7 100644
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -31,7 +31,6 @@ struct dm_io_client {
*/
struct io {
unsigned long error_bits;
- unsigned long eopnotsupp_bits;
atomic_t count;
struct task_struct *sleeper;
struct dm_io_client *client;
@@ -130,11 +129,8 @@ static void retrieve_io_and_region_from_bio(struct bio *bio, struct io **io,
*---------------------------------------------------------------*/
static void dec_count(struct io *io, unsigned int region, int error)
{
- if (error) {
+ if (error)
set_bit(region, &io->error_bits);
- if (error == -EOPNOTSUPP)
- set_bit(region, &io->eopnotsupp_bits);
- }
if (atomic_dec_and_test(&io->count)) {
if (io->sleeper)
@@ -310,8 +306,8 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where,
sector_t remaining = where->count;
/*
- * where->count may be zero if rw holds a write barrier and we
- * need to send a zero-sized barrier.
+ * where->count may be zero if rw holds a flush and we need to
+ * send a zero-sized flush.
*/
do {
/*
@@ -364,7 +360,7 @@ static void dispatch_io(int rw, unsigned int num_regions,
*/
for (i = 0; i < num_regions; i++) {
*dp = old_pages;
- if (where[i].count || (rw & REQ_HARDBARRIER))
+ if (where[i].count || (rw & REQ_FLUSH))
do_region(rw, i, where + i, dp, io);
}
@@ -393,9 +389,7 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions,
return -EIO;
}
-retry:
io->error_bits = 0;
- io->eopnotsupp_bits = 0;
atomic_set(&io->count, 1); /* see dispatch_io() */
io->sleeper = current;
io->client = client;
@@ -412,11 +406,6 @@ retry:
}
set_current_state(TASK_RUNNING);
- if (io->eopnotsupp_bits && (rw & REQ_HARDBARRIER)) {
- rw &= ~REQ_HARDBARRIER;
- goto retry;
- }
-
if (error_bits)
*error_bits = io->error_bits;
@@ -437,7 +426,6 @@ static int async_io(struct dm_io_client *client, unsigned int num_regions,
io = mempool_alloc(client->pool, GFP_NOIO);
io->error_bits = 0;
- io->eopnotsupp_bits = 0;
atomic_set(&io->count, 1); /* see dispatch_io() */
io->sleeper = NULL;
io->client = client;
diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c
index 5a08be0..33420e6 100644
--- a/drivers/md/dm-log.c
+++ b/drivers/md/dm-log.c
@@ -300,7 +300,7 @@ static int flush_header(struct log_c *lc)
.count = 0,
};
- lc->io_req.bi_rw = WRITE_BARRIER;
+ lc->io_req.bi_rw = WRITE_FLUSH;
return dm_io(&lc->io_req, 1, &null_location, NULL);
}
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index 7c081bc..19a59b0 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -259,7 +259,7 @@ static int mirror_flush(struct dm_target *ti)
struct dm_io_region io[ms->nr_mirrors];
struct mirror *m;
struct dm_io_request io_req = {
- .bi_rw = WRITE_BARRIER,
+ .bi_rw = WRITE_FLUSH,
.mem.type = DM_IO_KMEM,
.mem.ptr.bvec = NULL,
.client = ms->io_client,
@@ -629,7 +629,7 @@ static void do_write(struct mirror_set *ms, struct bio *bio)
struct dm_io_region io[ms->nr_mirrors], *dest = io;
struct mirror *m;
struct dm_io_request io_req = {
- .bi_rw = WRITE | (bio->bi_rw & WRITE_BARRIER),
+ .bi_rw = WRITE | (bio->bi_rw & WRITE_FLUSH_FUA),
.mem.type = DM_IO_BVEC,
.mem.ptr.bvec = bio->bi_io_vec + bio->bi_idx,
.notify.fn = write_callback,
@@ -670,7 +670,7 @@ static void do_writes(struct mirror_set *ms, struct bio_list *writes)
bio_list_init(&requeue);
while ((bio = bio_list_pop(writes))) {
- if (unlikely(bio_empty_barrier(bio))) {
+ if (bio->bi_rw & REQ_FLUSH) {
bio_list_add(&sync, bio);
continue;
}
@@ -1203,7 +1203,7 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio,
* We need to dec pending if this was a write.
*/
if (rw == WRITE) {
- if (likely(!bio_empty_barrier(bio)))
+ if (!(bio->bi_rw & REQ_FLUSH))
dm_rh_dec(ms->rh, map_context->ll);
return error;
}
diff --git a/drivers/md/dm-region-hash.c b/drivers/md/dm-region-hash.c
index bd5c58b..dad011a 100644
--- a/drivers/md/dm-region-hash.c
+++ b/drivers/md/dm-region-hash.c
@@ -81,9 +81,9 @@ struct dm_region_hash {
struct list_head failed_recovered_regions;
/*
- * If there was a barrier failure no regions can be marked clean.
+ * If there was a flush failure no regions can be marked clean.
*/
- int barrier_failure;
+ int flush_failure;
void *context;
sector_t target_begin;
@@ -217,7 +217,7 @@ struct dm_region_hash *dm_region_hash_create(
INIT_LIST_HEAD(&rh->quiesced_regions);
INIT_LIST_HEAD(&rh->recovered_regions);
INIT_LIST_HEAD(&rh->failed_recovered_regions);
- rh->barrier_failure = 0;
+ rh->flush_failure = 0;
rh->region_pool = mempool_create_kmalloc_pool(MIN_REGIONS,
sizeof(struct dm_region));
@@ -399,8 +399,8 @@ void dm_rh_mark_nosync(struct dm_region_hash *rh, struct bio *bio)
region_t region = dm_rh_bio_to_region(rh, bio);
int recovering = 0;
- if (bio_empty_barrier(bio)) {
- rh->barrier_failure = 1;
+ if (bio->bi_rw & REQ_FLUSH) {
+ rh->flush_failure = 1;
return;
}
@@ -524,7 +524,7 @@ void dm_rh_inc_pending(struct dm_region_hash *rh, struct bio_list *bios)
struct bio *bio;
for (bio = bios->head; bio; bio = bio->bi_next) {
- if (bio_empty_barrier(bio))
+ if (bio->bi_rw & REQ_FLUSH)
continue;
rh_inc(rh, dm_rh_bio_to_region(rh, bio));
}
@@ -555,9 +555,9 @@ void dm_rh_dec(struct dm_region_hash *rh, region_t region)
*/
/* do nothing for DM_RH_NOSYNC */
- if (unlikely(rh->barrier_failure)) {
+ if (unlikely(rh->flush_failure)) {
/*
- * If a write barrier failed some time ago, we
+ * If a write flush failed some time ago, we
* don't know whether or not this write made it
* to the disk, so we must resync the device.
*/
diff --git a/drivers/md/dm-snap-persistent.c b/drivers/md/dm-snap-persistent.c
index cc2bdb8..0b61792 100644
--- a/drivers/md/dm-snap-persistent.c
+++ b/drivers/md/dm-snap-persistent.c
@@ -687,7 +687,7 @@ static void persistent_commit_exception(struct dm_exception_store *store,
/*
* Commit exceptions to disk.
*/
- if (ps->valid && area_io(ps, WRITE_BARRIER))
+ if (ps->valid && area_io(ps, WRITE_FLUSH_FUA))
ps->valid = 0;
/*
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 5974d30..eed2101 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -1587,7 +1587,7 @@ static int snapshot_map(struct dm_target *ti, struct bio *bio,
chunk_t chunk;
struct dm_snap_pending_exception *pe = NULL;
- if (unlikely(bio_empty_barrier(bio))) {
+ if (bio->bi_rw & REQ_FLUSH) {
bio->bi_bdev = s->cow->bdev;
return DM_MAPIO_REMAPPED;
}
@@ -1691,7 +1691,7 @@ static int snapshot_merge_map(struct dm_target *ti, struct bio *bio,
int r = DM_MAPIO_REMAPPED;
chunk_t chunk;
- if (unlikely(bio_empty_barrier(bio))) {
+ if (bio->bi_rw & REQ_FLUSH) {
if (!map_context->target_request_nr)
bio->bi_bdev = s->origin->bdev;
else
@@ -2135,7 +2135,7 @@ static int origin_map(struct dm_target *ti, struct bio *bio,
struct dm_dev *dev = ti->private;
bio->bi_bdev = dev->bdev;
- if (unlikely(bio_empty_barrier(bio)))
+ if (bio->bi_rw & REQ_FLUSH)
return DM_MAPIO_REMAPPED;
/* Only tell snapshots if this is a write */
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index c297f6d..f0371b4 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -271,7 +271,7 @@ static int stripe_map(struct dm_target *ti, struct bio *bio,
uint32_t stripe;
unsigned target_request_nr;
- if (unlikely(bio_empty_barrier(bio))) {
+ if (bio->bi_rw & REQ_FLUSH) {
target_request_nr = map_context->target_request_nr;
BUG_ON(target_request_nr >= sc->stripes);
bio->bi_bdev = sc->stripe[target_request_nr].dev->bdev;
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index b1d92be..32e6622 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -144,15 +144,16 @@ struct mapped_device {
spinlock_t deferred_lock;
/*
- * An error from the barrier request currently being processed.
+ * An error from the flush request currently being processed.
*/
- int barrier_error;
+ int flush_error;
/*
* Protect barrier_error from concurrent endio processing
* in request-based dm.
*/
spinlock_t barrier_error_lock;
+ int barrier_error;
/*
* Processing queue (flush/barriers)
@@ -200,8 +201,8 @@ struct mapped_device {
/* sysfs handle */
struct kobject kobj;
- /* zero-length barrier that will be cloned and submitted to targets */
- struct bio barrier_bio;
+ /* zero-length flush that will be cloned and submitted to targets */
+ struct bio flush_bio;
};
/*
@@ -512,7 +513,7 @@ static void end_io_acct(struct dm_io *io)
/*
* After this is decremented the bio must not be touched if it is
- * a barrier.
+ * a flush.
*/
dm_disk(md)->part0.in_flight[rw] = pending =
atomic_dec_return(&md->pending[rw]);
@@ -626,7 +627,7 @@ static void dec_pending(struct dm_io *io, int error)
*/
spin_lock_irqsave(&md->deferred_lock, flags);
if (__noflush_suspending(md)) {
- if (!(io->bio->bi_rw & REQ_HARDBARRIER))
+ if (!(io->bio->bi_rw & REQ_FLUSH))
bio_list_add_head(&md->deferred,
io->bio);
} else
@@ -638,20 +639,14 @@ static void dec_pending(struct dm_io *io, int error)
io_error = io->error;
bio = io->bio;
- if (bio->bi_rw & REQ_HARDBARRIER) {
+ if (bio->bi_rw & REQ_FLUSH) {
/*
- * There can be just one barrier request so we use
+ * There can be just one flush request so we use
* a per-device variable for error reporting.
* Note that you can't touch the bio after end_io_acct
- *
- * We ignore -EOPNOTSUPP for empty flush reported by
- * underlying devices. We assume that if the device
- * doesn't support empty barriers, it doesn't need
- * cache flushing commands.
*/
- if (!md->barrier_error &&
- !(bio_empty_barrier(bio) && io_error == -EOPNOTSUPP))
- md->barrier_error = io_error;
+ if (!md->flush_error)
+ md->flush_error = io_error;
end_io_acct(io);
free_io(md, io);
} else {
@@ -1119,7 +1114,7 @@ static void dm_bio_destructor(struct bio *bio)
}
/*
- * Creates a little bio that is just does part of a bvec.
+ * Creates a little bio that just does part of a bvec.
*/
static struct bio *split_bvec(struct bio *bio, sector_t sector,
unsigned short idx, unsigned int offset,
@@ -1134,7 +1129,7 @@ static struct bio *split_bvec(struct bio *bio, sector_t sector,
clone->bi_sector = sector;
clone->bi_bdev = bio->bi_bdev;
- clone->bi_rw = bio->bi_rw & ~REQ_HARDBARRIER;
+ clone->bi_rw = bio->bi_rw;
clone->bi_vcnt = 1;
clone->bi_size = to_bytes(len);
clone->bi_io_vec->bv_offset = offset;
@@ -1161,7 +1156,6 @@ static struct bio *clone_bio(struct bio *bio, sector_t sector,
clone = bio_alloc_bioset(GFP_NOIO, bio->bi_max_vecs, bs);
__bio_clone(clone, bio);
- clone->bi_rw &= ~REQ_HARDBARRIER;
clone->bi_destructor = dm_bio_destructor;
clone->bi_sector = sector;
clone->bi_idx = idx;
@@ -1225,7 +1219,7 @@ static void __issue_target_requests(struct clone_info *ci, struct dm_target *ti,
__issue_target_request(ci, ti, request_nr, len);
}
-static int __clone_and_map_empty_barrier(struct clone_info *ci)
+static int __clone_and_map_flush(struct clone_info *ci)
{
unsigned target_nr = 0;
struct dm_target *ti;
@@ -1289,9 +1283,6 @@ static int __clone_and_map(struct clone_info *ci)
sector_t len = 0, max;
struct dm_target_io *tio;
- if (unlikely(bio_empty_barrier(bio)))
- return __clone_and_map_empty_barrier(ci);
-
if (unlikely(bio->bi_rw & REQ_DISCARD))
return __clone_and_map_discard(ci);
@@ -1383,11 +1374,11 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
ci.map = dm_get_live_table(md);
if (unlikely(!ci.map)) {
- if (!(bio->bi_rw & REQ_HARDBARRIER))
+ if (!(bio->bi_rw & REQ_FLUSH))
bio_io_error(bio);
else
- if (!md->barrier_error)
- md->barrier_error = -EIO;
+ if (!md->flush_error)
+ md->flush_error = -EIO;
return;
}
@@ -1400,14 +1391,22 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
ci.io->md = md;
spin_lock_init(&ci.io->endio_lock);
ci.sector = bio->bi_sector;
- ci.sector_count = bio_sectors(bio);
- if (unlikely(bio_empty_barrier(bio)))
+ if (!(bio->bi_rw & REQ_FLUSH))
+ ci.sector_count = bio_sectors(bio);
+ else {
+ /* all FLUSH bio's reaching here should be empty */
+ WARN_ON_ONCE(bio_has_data(bio));
ci.sector_count = 1;
+ }
ci.idx = bio->bi_idx;
start_io_acct(ci.io);
- while (ci.sector_count && !error)
- error = __clone_and_map(&ci);
+ while (ci.sector_count && !error) {
+ if (!(bio->bi_rw & REQ_FLUSH))
+ error = __clone_and_map(&ci);
+ else
+ error = __clone_and_map_flush(&ci);
+ }
/* drop the extra reference count */
dec_pending(ci.io, error);
@@ -1492,11 +1491,11 @@ static int _dm_request(struct request_queue *q, struct bio *bio)
part_stat_unlock();
/*
- * If we're suspended or the thread is processing barriers
+ * If we're suspended or the thread is processing flushes
* we have to queue this io for later.
*/
if (unlikely(test_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags)) ||
- unlikely(bio->bi_rw & REQ_HARDBARRIER)) {
+ (bio->bi_rw & REQ_FLUSH)) {
up_read(&md->io_lock);
if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) &&
@@ -1940,6 +1939,7 @@ static void dm_init_md_queue(struct mapped_device *md)
blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY);
md->queue->unplug_fn = dm_unplug_all;
blk_queue_merge_bvec(md->queue, dm_merge_bvec);
+ blk_queue_flush(md->queue, REQ_FLUSH | REQ_FUA);
}
/*
@@ -2245,7 +2245,8 @@ static int dm_init_request_based_queue(struct mapped_device *md)
blk_queue_softirq_done(md->queue, dm_softirq_done);
blk_queue_prep_rq(md->queue, dm_prep_fn);
blk_queue_lld_busy(md->queue, dm_lld_busy);
- blk_queue_flush(md->queue, REQ_FLUSH);
+ /* no flush support for request based dm yet */
+ blk_queue_flush(md->queue, 0);
elv_register_queue(md->queue);
@@ -2406,41 +2407,35 @@ static int dm_wait_for_completion(struct mapped_device *md, int interruptible)
return r;
}
-static void dm_flush(struct mapped_device *md)
+static void process_flush(struct mapped_device *md, struct bio *bio)
{
- dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
-
- bio_init(&md->barrier_bio);
- md->barrier_bio.bi_bdev = md->bdev;
- md->barrier_bio.bi_rw = WRITE_BARRIER;
- __split_and_process_bio(md, &md->barrier_bio);
+ md->flush_error = 0;
+ /* handle REQ_FLUSH */
dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
-}
-static void process_barrier(struct mapped_device *md, struct bio *bio)
-{
- md->barrier_error = 0;
+ bio_init(&md->flush_bio);
+ md->flush_bio.bi_bdev = md->bdev;
+ md->flush_bio.bi_rw = WRITE_FLUSH;
+ __split_and_process_bio(md, &md->flush_bio);
- dm_flush(md);
+ dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
- if (!bio_empty_barrier(bio)) {
- __split_and_process_bio(md, bio);
- /*
- * If the request isn't supported, don't waste time with
- * the second flush.
- */
- if (md->barrier_error != -EOPNOTSUPP)
- dm_flush(md);
+ /* if it's an empty flush or the preflush failed, we're done */
+ if (!bio_has_data(bio) || md->flush_error) {
+ if (md->flush_error != DM_ENDIO_REQUEUE)
+ bio_endio(bio, md->flush_error);
+ else {
+ spin_lock_irq(&md->deferred_lock);
+ bio_list_add_head(&md->deferred, bio);
+ spin_unlock_irq(&md->deferred_lock);
+ }
+ return;
}
- if (md->barrier_error != DM_ENDIO_REQUEUE)
- bio_endio(bio, md->barrier_error);
- else {
- spin_lock_irq(&md->deferred_lock);
- bio_list_add_head(&md->deferred, bio);
- spin_unlock_irq(&md->deferred_lock);
- }
+ /* issue data + REQ_FUA */
+ bio->bi_rw &= ~REQ_FLUSH;
+ __split_and_process_bio(md, bio);
}
/*
@@ -2469,8 +2464,8 @@ static void dm_wq_work(struct work_struct *work)
if (dm_request_based(md))
generic_make_request(c);
else {
- if (c->bi_rw & REQ_HARDBARRIER)
- process_barrier(md, c);
+ if (c->bi_rw & REQ_FLUSH)
+ process_flush(md, c);
else
__split_and_process_bio(md, c);
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 24/41] dm: implement REQ_FLUSH/FUA support for request-based dm
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
This patch converts request-based dm to support the new REQ_FLUSH/FUA.
The original request-based flush implementation depended on
request_queue blocking other requests while a barrier sequence is in
progress, which is no longer true for the new REQ_FLUSH/FUA.
In general, request-based dm doesn't have infrastructure for cloning
one source request to multiple targets, but the original flush
implementation had a special mostly independent path which can issue
flushes to multiple targets and sequence them. However, the
capability isn't currently in use and adds a lot of complexity.
Moreoever, it's unlikely to be useful in its current form as it
doesn't make sense to be able to send out flushes to multiple targets
when write requests can't be.
This patch rips out special flush code path and deals handles
REQ_FLUSH/FUA requests the same way as other requests. The only
special treatment is that REQ_FLUSH requests use the block address 0
when finding target, which is enough for now.
* added BUG_ON(!dm_target_is_valid(ti)) in dm_request_fn() as
suggested by Mike Snitzer
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Mike Snitzer <snitzer@redhat.com>
---
drivers/md/dm.c | 206 ++++++-------------------------------------------------
1 files changed, 22 insertions(+), 184 deletions(-)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 32e6622..65114e4 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -149,20 +149,9 @@ struct mapped_device {
int flush_error;
/*
- * Protect barrier_error from concurrent endio processing
- * in request-based dm.
- */
- spinlock_t barrier_error_lock;
- int barrier_error;
-
- /*
- * Processing queue (flush/barriers)
+ * Processing queue (flush)
*/
struct workqueue_struct *wq;
- struct work_struct barrier_work;
-
- /* A pointer to the currently processing pre/post flush request */
- struct request *flush_request;
/*
* The current mapping.
@@ -750,23 +739,6 @@ static void end_clone_bio(struct bio *clone, int error)
blk_update_request(tio->orig, 0, nr_bytes);
}
-static void store_barrier_error(struct mapped_device *md, int error)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&md->barrier_error_lock, flags);
- /*
- * Basically, the first error is taken, but:
- * -EOPNOTSUPP supersedes any I/O error.
- * Requeue request supersedes any I/O error but -EOPNOTSUPP.
- */
- if (!md->barrier_error || error == -EOPNOTSUPP ||
- (md->barrier_error != -EOPNOTSUPP &&
- error == DM_ENDIO_REQUEUE))
- md->barrier_error = error;
- spin_unlock_irqrestore(&md->barrier_error_lock, flags);
-}
-
/*
* Don't touch any member of the md after calling this function because
* the md may be freed in dm_put() at the end of this function.
@@ -804,13 +776,11 @@ static void free_rq_clone(struct request *clone)
static void dm_end_request(struct request *clone, int error)
{
int rw = rq_data_dir(clone);
- int run_queue = 1;
- bool is_barrier = clone->cmd_flags & REQ_HARDBARRIER;
struct dm_rq_target_io *tio = clone->end_io_data;
struct mapped_device *md = tio->md;
struct request *rq = tio->orig;
- if (rq->cmd_type == REQ_TYPE_BLOCK_PC && !is_barrier) {
+ if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
rq->errors = clone->errors;
rq->resid_len = clone->resid_len;
@@ -824,15 +794,8 @@ static void dm_end_request(struct request *clone, int error)
}
free_rq_clone(clone);
-
- if (unlikely(is_barrier)) {
- if (unlikely(error))
- store_barrier_error(md, error);
- run_queue = 0;
- } else
- blk_end_request_all(rq, error);
-
- rq_completed(md, rw, run_queue);
+ blk_end_request_all(rq, error);
+ rq_completed(md, rw, true);
}
static void dm_unprep_request(struct request *rq)
@@ -857,16 +820,6 @@ void dm_requeue_unmapped_request(struct request *clone)
struct request_queue *q = rq->q;
unsigned long flags;
- if (unlikely(clone->cmd_flags & REQ_HARDBARRIER)) {
- /*
- * Barrier clones share an original request.
- * Leave it to dm_end_request(), which handles this special
- * case.
- */
- dm_end_request(clone, DM_ENDIO_REQUEUE);
- return;
- }
-
dm_unprep_request(rq);
spin_lock_irqsave(q->queue_lock, flags);
@@ -956,19 +909,6 @@ static void dm_complete_request(struct request *clone, int error)
struct dm_rq_target_io *tio = clone->end_io_data;
struct request *rq = tio->orig;
- if (unlikely(clone->cmd_flags & REQ_HARDBARRIER)) {
- /*
- * Barrier clones share an original request. So can't use
- * softirq_done with the original.
- * Pass the clone to dm_done() directly in this special case.
- * It is safe (even if clone->q->queue_lock is held here)
- * because there is no I/O dispatching during the completion
- * of barrier clone.
- */
- dm_done(clone, error, true);
- return;
- }
-
tio->error = error;
rq->completion_data = clone;
blk_complete_request(rq);
@@ -985,17 +925,6 @@ void dm_kill_unmapped_request(struct request *clone, int error)
struct dm_rq_target_io *tio = clone->end_io_data;
struct request *rq = tio->orig;
- if (unlikely(clone->cmd_flags & REQ_HARDBARRIER)) {
- /*
- * Barrier clones share an original request.
- * Leave it to dm_end_request(), which handles this special
- * case.
- */
- BUG_ON(error > 0);
- dm_end_request(clone, error);
- return;
- }
-
rq->cmd_flags |= REQ_FAILED;
dm_complete_request(clone, error);
}
@@ -1536,14 +1465,6 @@ static int dm_request(struct request_queue *q, struct bio *bio)
return _dm_request(q, bio);
}
-static bool dm_rq_is_flush_request(struct request *rq)
-{
- if (rq->cmd_flags & REQ_FLUSH)
- return true;
- else
- return false;
-}
-
void dm_dispatch_request(struct request *rq)
{
int r;
@@ -1591,22 +1512,15 @@ static int setup_clone(struct request *clone, struct request *rq,
{
int r;
- if (dm_rq_is_flush_request(rq)) {
- blk_rq_init(NULL, clone);
- clone->cmd_type = REQ_TYPE_FS;
- clone->cmd_flags |= (REQ_HARDBARRIER | WRITE);
- } else {
- r = blk_rq_prep_clone(clone, rq, tio->md->bs, GFP_ATOMIC,
- dm_rq_bio_constructor, tio);
- if (r)
- return r;
-
- clone->cmd = rq->cmd;
- clone->cmd_len = rq->cmd_len;
- clone->sense = rq->sense;
- clone->buffer = rq->buffer;
- }
+ r = blk_rq_prep_clone(clone, rq, tio->md->bs, GFP_ATOMIC,
+ dm_rq_bio_constructor, tio);
+ if (r)
+ return r;
+ clone->cmd = rq->cmd;
+ clone->cmd_len = rq->cmd_len;
+ clone->sense = rq->sense;
+ clone->buffer = rq->buffer;
clone->end_io = end_clone_request;
clone->end_io_data = tio;
@@ -1647,9 +1561,6 @@ static int dm_prep_fn(struct request_queue *q, struct request *rq)
struct mapped_device *md = q->queuedata;
struct request *clone;
- if (unlikely(dm_rq_is_flush_request(rq)))
- return BLKPREP_OK;
-
if (unlikely(rq->special)) {
DMWARN("Already has something in rq->special.");
return BLKPREP_KILL;
@@ -1726,6 +1637,7 @@ static void dm_request_fn(struct request_queue *q)
struct dm_table *map = dm_get_live_table(md);
struct dm_target *ti;
struct request *rq, *clone;
+ sector_t pos;
/*
* For suspend, check blk_queue_stopped() and increment
@@ -1738,15 +1650,14 @@ static void dm_request_fn(struct request_queue *q)
if (!rq)
goto plug_and_out;
- if (unlikely(dm_rq_is_flush_request(rq))) {
- BUG_ON(md->flush_request);
- md->flush_request = rq;
- blk_start_request(rq);
- queue_work(md->wq, &md->barrier_work);
- goto out;
- }
+ /* always use block 0 to find the target for flushes for now */
+ pos = 0;
+ if (!(rq->cmd_flags & REQ_FLUSH))
+ pos = blk_rq_pos(rq);
+
+ ti = dm_table_find_target(map, pos);
+ BUG_ON(!dm_target_is_valid(ti));
- ti = dm_table_find_target(map, blk_rq_pos(rq));
if (ti->type->busy && ti->type->busy(ti))
goto plug_and_out;
@@ -1917,7 +1828,6 @@ out:
static const struct block_device_operations dm_blk_dops;
static void dm_wq_work(struct work_struct *work);
-static void dm_rq_barrier_work(struct work_struct *work);
static void dm_init_md_queue(struct mapped_device *md)
{
@@ -1972,7 +1882,6 @@ static struct mapped_device *alloc_dev(int minor)
mutex_init(&md->suspend_lock);
mutex_init(&md->type_lock);
spin_lock_init(&md->deferred_lock);
- spin_lock_init(&md->barrier_error_lock);
rwlock_init(&md->map_lock);
atomic_set(&md->holders, 1);
atomic_set(&md->open_count, 0);
@@ -1995,7 +1904,6 @@ static struct mapped_device *alloc_dev(int minor)
atomic_set(&md->pending[1], 0);
init_waitqueue_head(&md->wait);
INIT_WORK(&md->work, dm_wq_work);
- INIT_WORK(&md->barrier_work, dm_rq_barrier_work);
init_waitqueue_head(&md->eventq);
md->disk->major = _major;
@@ -2245,8 +2153,6 @@ static int dm_init_request_based_queue(struct mapped_device *md)
blk_queue_softirq_done(md->queue, dm_softirq_done);
blk_queue_prep_rq(md->queue, dm_prep_fn);
blk_queue_lld_busy(md->queue, dm_lld_busy);
- /* no flush support for request based dm yet */
- blk_queue_flush(md->queue, 0);
elv_register_queue(md->queue);
@@ -2483,73 +2389,6 @@ static void dm_queue_flush(struct mapped_device *md)
queue_work(md->wq, &md->work);
}
-static void dm_rq_set_target_request_nr(struct request *clone, unsigned request_nr)
-{
- struct dm_rq_target_io *tio = clone->end_io_data;
-
- tio->info.target_request_nr = request_nr;
-}
-
-/* Issue barrier requests to targets and wait for their completion. */
-static int dm_rq_barrier(struct mapped_device *md)
-{
- int i, j;
- struct dm_table *map = dm_get_live_table(md);
- unsigned num_targets = dm_table_get_num_targets(map);
- struct dm_target *ti;
- struct request *clone;
-
- md->barrier_error = 0;
-
- for (i = 0; i < num_targets; i++) {
- ti = dm_table_get_target(map, i);
- for (j = 0; j < ti->num_flush_requests; j++) {
- clone = clone_rq(md->flush_request, md, GFP_NOIO);
- dm_rq_set_target_request_nr(clone, j);
- atomic_inc(&md->pending[rq_data_dir(clone)]);
- map_request(ti, clone, md);
- }
- }
-
- dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
- dm_table_put(map);
-
- return md->barrier_error;
-}
-
-static void dm_rq_barrier_work(struct work_struct *work)
-{
- int error;
- struct mapped_device *md = container_of(work, struct mapped_device,
- barrier_work);
- struct request_queue *q = md->queue;
- struct request *rq;
- unsigned long flags;
-
- /*
- * Hold the md reference here and leave it at the last part so that
- * the md can't be deleted by device opener when the barrier request
- * completes.
- */
- dm_get(md);
-
- error = dm_rq_barrier(md);
-
- rq = md->flush_request;
- md->flush_request = NULL;
-
- if (error == DM_ENDIO_REQUEUE) {
- spin_lock_irqsave(q->queue_lock, flags);
- blk_requeue_request(q, rq);
- spin_unlock_irqrestore(q->queue_lock, flags);
- } else
- blk_end_request_all(rq, error);
-
- blk_run_queue(q);
-
- dm_put(md);
-}
-
/*
* Swap in a new table, returning the old one for the caller to destroy.
*/
@@ -2686,9 +2525,8 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
up_write(&md->io_lock);
/*
- * Request-based dm uses md->wq for barrier (dm_rq_barrier_work) which
- * can be kicked until md->queue is stopped. So stop md->queue before
- * flushing md->wq.
+ * Stop md->queue before flushing md->wq in case request-based
+ * dm defers requests to md->wq from md->queue.
*/
if (dm_request_based(md))
stop_queue(md->queue);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 24/41] dm: implement REQ_FLUSH/FUA support for request-based dm
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
This patch converts request-based dm to support the new REQ_FLUSH/FUA.
The original request-based flush implementation depended on
request_queue blocking other requests while a barrier sequence is in
progress, which is no longer true for the new REQ_FLUSH/FUA.
In general, request-based dm doesn't have infrastructure for cloning
one source request to multiple targets, but the original flush
implementation had a special mostly independent path which can issue
flushes to multiple targets and sequence them. However, the
capability isn't currently in use and adds a lot of complexity.
Moreoever, it's unlikely to be useful in its current form as it
doesn't make sense to be able to send out flushes to multiple targets
when write requests can't be.
This patch rips out special flush code path and deals handles
REQ_FLUSH/FUA requests the same way as other requests. The only
special treatment is that REQ_FLUSH requests use the block address 0
when finding target, which is enough for now.
* added BUG_ON(!dm_target_is_valid(ti)) in dm_request_fn() as
suggested by Mike Snitzer
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Mike Snitzer <snitzer@redhat.com>
---
drivers/md/dm.c | 206 ++++++-------------------------------------------------
1 files changed, 22 insertions(+), 184 deletions(-)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 32e6622..65114e4 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -149,20 +149,9 @@ struct mapped_device {
int flush_error;
/*
- * Protect barrier_error from concurrent endio processing
- * in request-based dm.
- */
- spinlock_t barrier_error_lock;
- int barrier_error;
-
- /*
- * Processing queue (flush/barriers)
+ * Processing queue (flush)
*/
struct workqueue_struct *wq;
- struct work_struct barrier_work;
-
- /* A pointer to the currently processing pre/post flush request */
- struct request *flush_request;
/*
* The current mapping.
@@ -750,23 +739,6 @@ static void end_clone_bio(struct bio *clone, int error)
blk_update_request(tio->orig, 0, nr_bytes);
}
-static void store_barrier_error(struct mapped_device *md, int error)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&md->barrier_error_lock, flags);
- /*
- * Basically, the first error is taken, but:
- * -EOPNOTSUPP supersedes any I/O error.
- * Requeue request supersedes any I/O error but -EOPNOTSUPP.
- */
- if (!md->barrier_error || error == -EOPNOTSUPP ||
- (md->barrier_error != -EOPNOTSUPP &&
- error == DM_ENDIO_REQUEUE))
- md->barrier_error = error;
- spin_unlock_irqrestore(&md->barrier_error_lock, flags);
-}
-
/*
* Don't touch any member of the md after calling this function because
* the md may be freed in dm_put() at the end of this function.
@@ -804,13 +776,11 @@ static void free_rq_clone(struct request *clone)
static void dm_end_request(struct request *clone, int error)
{
int rw = rq_data_dir(clone);
- int run_queue = 1;
- bool is_barrier = clone->cmd_flags & REQ_HARDBARRIER;
struct dm_rq_target_io *tio = clone->end_io_data;
struct mapped_device *md = tio->md;
struct request *rq = tio->orig;
- if (rq->cmd_type == REQ_TYPE_BLOCK_PC && !is_barrier) {
+ if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
rq->errors = clone->errors;
rq->resid_len = clone->resid_len;
@@ -824,15 +794,8 @@ static void dm_end_request(struct request *clone, int error)
}
free_rq_clone(clone);
-
- if (unlikely(is_barrier)) {
- if (unlikely(error))
- store_barrier_error(md, error);
- run_queue = 0;
- } else
- blk_end_request_all(rq, error);
-
- rq_completed(md, rw, run_queue);
+ blk_end_request_all(rq, error);
+ rq_completed(md, rw, true);
}
static void dm_unprep_request(struct request *rq)
@@ -857,16 +820,6 @@ void dm_requeue_unmapped_request(struct request *clone)
struct request_queue *q = rq->q;
unsigned long flags;
- if (unlikely(clone->cmd_flags & REQ_HARDBARRIER)) {
- /*
- * Barrier clones share an original request.
- * Leave it to dm_end_request(), which handles this special
- * case.
- */
- dm_end_request(clone, DM_ENDIO_REQUEUE);
- return;
- }
-
dm_unprep_request(rq);
spin_lock_irqsave(q->queue_lock, flags);
@@ -956,19 +909,6 @@ static void dm_complete_request(struct request *clone, int error)
struct dm_rq_target_io *tio = clone->end_io_data;
struct request *rq = tio->orig;
- if (unlikely(clone->cmd_flags & REQ_HARDBARRIER)) {
- /*
- * Barrier clones share an original request. So can't use
- * softirq_done with the original.
- * Pass the clone to dm_done() directly in this special case.
- * It is safe (even if clone->q->queue_lock is held here)
- * because there is no I/O dispatching during the completion
- * of barrier clone.
- */
- dm_done(clone, error, true);
- return;
- }
-
tio->error = error;
rq->completion_data = clone;
blk_complete_request(rq);
@@ -985,17 +925,6 @@ void dm_kill_unmapped_request(struct request *clone, int error)
struct dm_rq_target_io *tio = clone->end_io_data;
struct request *rq = tio->orig;
- if (unlikely(clone->cmd_flags & REQ_HARDBARRIER)) {
- /*
- * Barrier clones share an original request.
- * Leave it to dm_end_request(), which handles this special
- * case.
- */
- BUG_ON(error > 0);
- dm_end_request(clone, error);
- return;
- }
-
rq->cmd_flags |= REQ_FAILED;
dm_complete_request(clone, error);
}
@@ -1536,14 +1465,6 @@ static int dm_request(struct request_queue *q, struct bio *bio)
return _dm_request(q, bio);
}
-static bool dm_rq_is_flush_request(struct request *rq)
-{
- if (rq->cmd_flags & REQ_FLUSH)
- return true;
- else
- return false;
-}
-
void dm_dispatch_request(struct request *rq)
{
int r;
@@ -1591,22 +1512,15 @@ static int setup_clone(struct request *clone, struct request *rq,
{
int r;
- if (dm_rq_is_flush_request(rq)) {
- blk_rq_init(NULL, clone);
- clone->cmd_type = REQ_TYPE_FS;
- clone->cmd_flags |= (REQ_HARDBARRIER | WRITE);
- } else {
- r = blk_rq_prep_clone(clone, rq, tio->md->bs, GFP_ATOMIC,
- dm_rq_bio_constructor, tio);
- if (r)
- return r;
-
- clone->cmd = rq->cmd;
- clone->cmd_len = rq->cmd_len;
- clone->sense = rq->sense;
- clone->buffer = rq->buffer;
- }
+ r = blk_rq_prep_clone(clone, rq, tio->md->bs, GFP_ATOMIC,
+ dm_rq_bio_constructor, tio);
+ if (r)
+ return r;
+ clone->cmd = rq->cmd;
+ clone->cmd_len = rq->cmd_len;
+ clone->sense = rq->sense;
+ clone->buffer = rq->buffer;
clone->end_io = end_clone_request;
clone->end_io_data = tio;
@@ -1647,9 +1561,6 @@ static int dm_prep_fn(struct request_queue *q, struct request *rq)
struct mapped_device *md = q->queuedata;
struct request *clone;
- if (unlikely(dm_rq_is_flush_request(rq)))
- return BLKPREP_OK;
-
if (unlikely(rq->special)) {
DMWARN("Already has something in rq->special.");
return BLKPREP_KILL;
@@ -1726,6 +1637,7 @@ static void dm_request_fn(struct request_queue *q)
struct dm_table *map = dm_get_live_table(md);
struct dm_target *ti;
struct request *rq, *clone;
+ sector_t pos;
/*
* For suspend, check blk_queue_stopped() and increment
@@ -1738,15 +1650,14 @@ static void dm_request_fn(struct request_queue *q)
if (!rq)
goto plug_and_out;
- if (unlikely(dm_rq_is_flush_request(rq))) {
- BUG_ON(md->flush_request);
- md->flush_request = rq;
- blk_start_request(rq);
- queue_work(md->wq, &md->barrier_work);
- goto out;
- }
+ /* always use block 0 to find the target for flushes for now */
+ pos = 0;
+ if (!(rq->cmd_flags & REQ_FLUSH))
+ pos = blk_rq_pos(rq);
+
+ ti = dm_table_find_target(map, pos);
+ BUG_ON(!dm_target_is_valid(ti));
- ti = dm_table_find_target(map, blk_rq_pos(rq));
if (ti->type->busy && ti->type->busy(ti))
goto plug_and_out;
@@ -1917,7 +1828,6 @@ out:
static const struct block_device_operations dm_blk_dops;
static void dm_wq_work(struct work_struct *work);
-static void dm_rq_barrier_work(struct work_struct *work);
static void dm_init_md_queue(struct mapped_device *md)
{
@@ -1972,7 +1882,6 @@ static struct mapped_device *alloc_dev(int minor)
mutex_init(&md->suspend_lock);
mutex_init(&md->type_lock);
spin_lock_init(&md->deferred_lock);
- spin_lock_init(&md->barrier_error_lock);
rwlock_init(&md->map_lock);
atomic_set(&md->holders, 1);
atomic_set(&md->open_count, 0);
@@ -1995,7 +1904,6 @@ static struct mapped_device *alloc_dev(int minor)
atomic_set(&md->pending[1], 0);
init_waitqueue_head(&md->wait);
INIT_WORK(&md->work, dm_wq_work);
- INIT_WORK(&md->barrier_work, dm_rq_barrier_work);
init_waitqueue_head(&md->eventq);
md->disk->major = _major;
@@ -2245,8 +2153,6 @@ static int dm_init_request_based_queue(struct mapped_device *md)
blk_queue_softirq_done(md->queue, dm_softirq_done);
blk_queue_prep_rq(md->queue, dm_prep_fn);
blk_queue_lld_busy(md->queue, dm_lld_busy);
- /* no flush support for request based dm yet */
- blk_queue_flush(md->queue, 0);
elv_register_queue(md->queue);
@@ -2483,73 +2389,6 @@ static void dm_queue_flush(struct mapped_device *md)
queue_work(md->wq, &md->work);
}
-static void dm_rq_set_target_request_nr(struct request *clone, unsigned request_nr)
-{
- struct dm_rq_target_io *tio = clone->end_io_data;
-
- tio->info.target_request_nr = request_nr;
-}
-
-/* Issue barrier requests to targets and wait for their completion. */
-static int dm_rq_barrier(struct mapped_device *md)
-{
- int i, j;
- struct dm_table *map = dm_get_live_table(md);
- unsigned num_targets = dm_table_get_num_targets(map);
- struct dm_target *ti;
- struct request *clone;
-
- md->barrier_error = 0;
-
- for (i = 0; i < num_targets; i++) {
- ti = dm_table_get_target(map, i);
- for (j = 0; j < ti->num_flush_requests; j++) {
- clone = clone_rq(md->flush_request, md, GFP_NOIO);
- dm_rq_set_target_request_nr(clone, j);
- atomic_inc(&md->pending[rq_data_dir(clone)]);
- map_request(ti, clone, md);
- }
- }
-
- dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
- dm_table_put(map);
-
- return md->barrier_error;
-}
-
-static void dm_rq_barrier_work(struct work_struct *work)
-{
- int error;
- struct mapped_device *md = container_of(work, struct mapped_device,
- barrier_work);
- struct request_queue *q = md->queue;
- struct request *rq;
- unsigned long flags;
-
- /*
- * Hold the md reference here and leave it at the last part so that
- * the md can't be deleted by device opener when the barrier request
- * completes.
- */
- dm_get(md);
-
- error = dm_rq_barrier(md);
-
- rq = md->flush_request;
- md->flush_request = NULL;
-
- if (error == DM_ENDIO_REQUEUE) {
- spin_lock_irqsave(q->queue_lock, flags);
- blk_requeue_request(q, rq);
- spin_unlock_irqrestore(q->queue_lock, flags);
- } else
- blk_end_request_all(rq, error);
-
- blk_run_queue(q);
-
- dm_put(md);
-}
-
/*
* Swap in a new table, returning the old one for the caller to destroy.
*/
@@ -2686,9 +2525,8 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
up_write(&md->io_lock);
/*
- * Request-based dm uses md->wq for barrier (dm_rq_barrier_work) which
- * can be kicked until md->queue is stopped. So stop md->queue before
- * flushing md->wq.
+ * Stop md->queue before flushing md->wq in case request-based
+ * dm defers requests to md->wq from md->queue.
*/
if (dm_request_based(md))
stop_queue(md->queue);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 24/41] dm: implement REQ_FLUSH/FUA support for request-based dm
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo
This patch converts request-based dm to support the new REQ_FLUSH/FUA.
The original request-based flush implementation depended on
request_queue blocking other requests while a barrier sequence is in
progress, which is no longer true for the new REQ_FLUSH/FUA.
In general, request-based dm doesn't have infrastructure for cloning
one source request to multiple targets, but the original flush
implementation had a special mostly independent path which can issue
flushes to multiple targets and sequence them. However, the
capability isn't currently in use and adds a lot of complexity.
Moreoever, it's unlikely to be useful in its current form as it
doesn't make sense to be able to send out flushes to multiple targets
when write requests can't be.
This patch rips out special flush code path and deals handles
REQ_FLUSH/FUA requests the same way as other requests. The only
special treatment is that REQ_FLUSH requests use the block address 0
when finding target, which is enough for now.
* added BUG_ON(!dm_target_is_valid(ti)) in dm_request_fn() as
suggested by Mike Snitzer
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Mike Snitzer <snitzer@redhat.com>
---
drivers/md/dm.c | 206 ++++++-------------------------------------------------
1 files changed, 22 insertions(+), 184 deletions(-)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 32e6622..65114e4 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -149,20 +149,9 @@ struct mapped_device {
int flush_error;
/*
- * Protect barrier_error from concurrent endio processing
- * in request-based dm.
- */
- spinlock_t barrier_error_lock;
- int barrier_error;
-
- /*
- * Processing queue (flush/barriers)
+ * Processing queue (flush)
*/
struct workqueue_struct *wq;
- struct work_struct barrier_work;
-
- /* A pointer to the currently processing pre/post flush request */
- struct request *flush_request;
/*
* The current mapping.
@@ -750,23 +739,6 @@ static void end_clone_bio(struct bio *clone, int error)
blk_update_request(tio->orig, 0, nr_bytes);
}
-static void store_barrier_error(struct mapped_device *md, int error)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&md->barrier_error_lock, flags);
- /*
- * Basically, the first error is taken, but:
- * -EOPNOTSUPP supersedes any I/O error.
- * Requeue request supersedes any I/O error but -EOPNOTSUPP.
- */
- if (!md->barrier_error || error == -EOPNOTSUPP ||
- (md->barrier_error != -EOPNOTSUPP &&
- error == DM_ENDIO_REQUEUE))
- md->barrier_error = error;
- spin_unlock_irqrestore(&md->barrier_error_lock, flags);
-}
-
/*
* Don't touch any member of the md after calling this function because
* the md may be freed in dm_put() at the end of this function.
@@ -804,13 +776,11 @@ static void free_rq_clone(struct request *clone)
static void dm_end_request(struct request *clone, int error)
{
int rw = rq_data_dir(clone);
- int run_queue = 1;
- bool is_barrier = clone->cmd_flags & REQ_HARDBARRIER;
struct dm_rq_target_io *tio = clone->end_io_data;
struct mapped_device *md = tio->md;
struct request *rq = tio->orig;
- if (rq->cmd_type == REQ_TYPE_BLOCK_PC && !is_barrier) {
+ if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
rq->errors = clone->errors;
rq->resid_len = clone->resid_len;
@@ -824,15 +794,8 @@ static void dm_end_request(struct request *clone, int error)
}
free_rq_clone(clone);
-
- if (unlikely(is_barrier)) {
- if (unlikely(error))
- store_barrier_error(md, error);
- run_queue = 0;
- } else
- blk_end_request_all(rq, error);
-
- rq_completed(md, rw, run_queue);
+ blk_end_request_all(rq, error);
+ rq_completed(md, rw, true);
}
static void dm_unprep_request(struct request *rq)
@@ -857,16 +820,6 @@ void dm_requeue_unmapped_request(struct request *clone)
struct request_queue *q = rq->q;
unsigned long flags;
- if (unlikely(clone->cmd_flags & REQ_HARDBARRIER)) {
- /*
- * Barrier clones share an original request.
- * Leave it to dm_end_request(), which handles this special
- * case.
- */
- dm_end_request(clone, DM_ENDIO_REQUEUE);
- return;
- }
-
dm_unprep_request(rq);
spin_lock_irqsave(q->queue_lock, flags);
@@ -956,19 +909,6 @@ static void dm_complete_request(struct request *clone, int error)
struct dm_rq_target_io *tio = clone->end_io_data;
struct request *rq = tio->orig;
- if (unlikely(clone->cmd_flags & REQ_HARDBARRIER)) {
- /*
- * Barrier clones share an original request. So can't use
- * softirq_done with the original.
- * Pass the clone to dm_done() directly in this special case.
- * It is safe (even if clone->q->queue_lock is held here)
- * because there is no I/O dispatching during the completion
- * of barrier clone.
- */
- dm_done(clone, error, true);
- return;
- }
-
tio->error = error;
rq->completion_data = clone;
blk_complete_request(rq);
@@ -985,17 +925,6 @@ void dm_kill_unmapped_request(struct request *clone, int error)
struct dm_rq_target_io *tio = clone->end_io_data;
struct request *rq = tio->orig;
- if (unlikely(clone->cmd_flags & REQ_HARDBARRIER)) {
- /*
- * Barrier clones share an original request.
- * Leave it to dm_end_request(), which handles this special
- * case.
- */
- BUG_ON(error > 0);
- dm_end_request(clone, error);
- return;
- }
-
rq->cmd_flags |= REQ_FAILED;
dm_complete_request(clone, error);
}
@@ -1536,14 +1465,6 @@ static int dm_request(struct request_queue *q, struct bio *bio)
return _dm_request(q, bio);
}
-static bool dm_rq_is_flush_request(struct request *rq)
-{
- if (rq->cmd_flags & REQ_FLUSH)
- return true;
- else
- return false;
-}
-
void dm_dispatch_request(struct request *rq)
{
int r;
@@ -1591,22 +1512,15 @@ static int setup_clone(struct request *clone, struct request *rq,
{
int r;
- if (dm_rq_is_flush_request(rq)) {
- blk_rq_init(NULL, clone);
- clone->cmd_type = REQ_TYPE_FS;
- clone->cmd_flags |= (REQ_HARDBARRIER | WRITE);
- } else {
- r = blk_rq_prep_clone(clone, rq, tio->md->bs, GFP_ATOMIC,
- dm_rq_bio_constructor, tio);
- if (r)
- return r;
-
- clone->cmd = rq->cmd;
- clone->cmd_len = rq->cmd_len;
- clone->sense = rq->sense;
- clone->buffer = rq->buffer;
- }
+ r = blk_rq_prep_clone(clone, rq, tio->md->bs, GFP_ATOMIC,
+ dm_rq_bio_constructor, tio);
+ if (r)
+ return r;
+ clone->cmd = rq->cmd;
+ clone->cmd_len = rq->cmd_len;
+ clone->sense = rq->sense;
+ clone->buffer = rq->buffer;
clone->end_io = end_clone_request;
clone->end_io_data = tio;
@@ -1647,9 +1561,6 @@ static int dm_prep_fn(struct request_queue *q, struct request *rq)
struct mapped_device *md = q->queuedata;
struct request *clone;
- if (unlikely(dm_rq_is_flush_request(rq)))
- return BLKPREP_OK;
-
if (unlikely(rq->special)) {
DMWARN("Already has something in rq->special.");
return BLKPREP_KILL;
@@ -1726,6 +1637,7 @@ static void dm_request_fn(struct request_queue *q)
struct dm_table *map = dm_get_live_table(md);
struct dm_target *ti;
struct request *rq, *clone;
+ sector_t pos;
/*
* For suspend, check blk_queue_stopped() and increment
@@ -1738,15 +1650,14 @@ static void dm_request_fn(struct request_queue *q)
if (!rq)
goto plug_and_out;
- if (unlikely(dm_rq_is_flush_request(rq))) {
- BUG_ON(md->flush_request);
- md->flush_request = rq;
- blk_start_request(rq);
- queue_work(md->wq, &md->barrier_work);
- goto out;
- }
+ /* always use block 0 to find the target for flushes for now */
+ pos = 0;
+ if (!(rq->cmd_flags & REQ_FLUSH))
+ pos = blk_rq_pos(rq);
+
+ ti = dm_table_find_target(map, pos);
+ BUG_ON(!dm_target_is_valid(ti));
- ti = dm_table_find_target(map, blk_rq_pos(rq));
if (ti->type->busy && ti->type->busy(ti))
goto plug_and_out;
@@ -1917,7 +1828,6 @@ out:
static const struct block_device_operations dm_blk_dops;
static void dm_wq_work(struct work_struct *work);
-static void dm_rq_barrier_work(struct work_struct *work);
static void dm_init_md_queue(struct mapped_device *md)
{
@@ -1972,7 +1882,6 @@ static struct mapped_device *alloc_dev(int minor)
mutex_init(&md->suspend_lock);
mutex_init(&md->type_lock);
spin_lock_init(&md->deferred_lock);
- spin_lock_init(&md->barrier_error_lock);
rwlock_init(&md->map_lock);
atomic_set(&md->holders, 1);
atomic_set(&md->open_count, 0);
@@ -1995,7 +1904,6 @@ static struct mapped_device *alloc_dev(int minor)
atomic_set(&md->pending[1], 0);
init_waitqueue_head(&md->wait);
INIT_WORK(&md->work, dm_wq_work);
- INIT_WORK(&md->barrier_work, dm_rq_barrier_work);
init_waitqueue_head(&md->eventq);
md->disk->major = _major;
@@ -2245,8 +2153,6 @@ static int dm_init_request_based_queue(struct mapped_device *md)
blk_queue_softirq_done(md->queue, dm_softirq_done);
blk_queue_prep_rq(md->queue, dm_prep_fn);
blk_queue_lld_busy(md->queue, dm_lld_busy);
- /* no flush support for request based dm yet */
- blk_queue_flush(md->queue, 0);
elv_register_queue(md->queue);
@@ -2483,73 +2389,6 @@ static void dm_queue_flush(struct mapped_device *md)
queue_work(md->wq, &md->work);
}
-static void dm_rq_set_target_request_nr(struct request *clone, unsigned request_nr)
-{
- struct dm_rq_target_io *tio = clone->end_io_data;
-
- tio->info.target_request_nr = request_nr;
-}
-
-/* Issue barrier requests to targets and wait for their completion. */
-static int dm_rq_barrier(struct mapped_device *md)
-{
- int i, j;
- struct dm_table *map = dm_get_live_table(md);
- unsigned num_targets = dm_table_get_num_targets(map);
- struct dm_target *ti;
- struct request *clone;
-
- md->barrier_error = 0;
-
- for (i = 0; i < num_targets; i++) {
- ti = dm_table_get_target(map, i);
- for (j = 0; j < ti->num_flush_requests; j++) {
- clone = clone_rq(md->flush_request, md, GFP_NOIO);
- dm_rq_set_target_request_nr(clone, j);
- atomic_inc(&md->pending[rq_data_dir(clone)]);
- map_request(ti, clone, md);
- }
- }
-
- dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
- dm_table_put(map);
-
- return md->barrier_error;
-}
-
-static void dm_rq_barrier_work(struct work_struct *work)
-{
- int error;
- struct mapped_device *md = container_of(work, struct mapped_device,
- barrier_work);
- struct request_queue *q = md->queue;
- struct request *rq;
- unsigned long flags;
-
- /*
- * Hold the md reference here and leave it at the last part so that
- * the md can't be deleted by device opener when the barrier request
- * completes.
- */
- dm_get(md);
-
- error = dm_rq_barrier(md);
-
- rq = md->flush_request;
- md->flush_request = NULL;
-
- if (error == DM_ENDIO_REQUEUE) {
- spin_lock_irqsave(q->queue_lock, flags);
- blk_requeue_request(q, rq);
- spin_unlock_irqrestore(q->queue_lock, flags);
- } else
- blk_end_request_all(rq, error);
-
- blk_run_queue(q);
-
- dm_put(md);
-}
-
/*
* Swap in a new table, returning the old one for the caller to destroy.
*/
@@ -2686,9 +2525,8 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
up_write(&md->io_lock);
/*
- * Request-based dm uses md->wq for barrier (dm_rq_barrier_work) which
- * can be kicked until md->queue is stopped. So stop md->queue before
- * flushing md->wq.
+ * Stop md->queue before flushing md->wq in case request-based
+ * dm defers requests to md->wq from md->queue.
*/
if (dm_request_based(md))
stop_queue(md->queue);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* Re: [PATCH 24/41] dm: implement REQ_FLUSH/FUA support for request-based dm
2010-09-03 10:29 ` Tejun Heo
(?)
(?)
@ 2010-09-08 1:46 ` Kiyoshi Ueda
-1 siblings, 0 replies; 159+ messages in thread
From: Kiyoshi Ueda @ 2010-09-08 1:46 UTC (permalink / raw)
To: Tejun Heo
Cc: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, mpatocka
Hi Tejun,
On 09/03/2010 07:29 PM +0900, Tejun Heo wrote:
> This patch converts request-based dm to support the new REQ_FLUSH/FUA.
I reviewed this patch and found no obvious problem.
Also, I tested this patch series using request-based dm-multipath +
ext3/ext4 and found no problem.
Tested-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Thanks,
Kiyoshi Ueda
^ permalink raw reply [flat|nested] 159+ messages in thread
* [PATCH 25/41] dm: relax ordering of bio-based flush implementation
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
Unlike REQ_HARDBARRIER, REQ_FLUSH/FUA doesn't mandate any ordering
against other bio's. This patch relaxes ordering around flushes.
* A flush bio is no longer deferred to workqueue directly. It's
processed like other bio's but __split_and_process_bio() uses
md->flush_bio as the clone source. md->flush_bio is initialized to
empty flush during md initialization and shared for all flushes.
* As a flush bio now travels through the same execution path as other
bio's, there's no need for dedicated error handling path either. It
can use the same error handling path in dec_pending(). Dedicated
error handling removed along with md->flush_error.
* When dec_pending() detects that a flush has completed, it checks
whether the original bio has data. If so, the bio is queued to the
deferred list w/ REQ_FLUSH cleared; otherwise, it's completed.
* As flush sequencing is handled in the usual issue/completion path,
dm_wq_work() no longer needs to handle flushes differently. Now its
only responsibility is re-issuing deferred bio's the same way as
_dm_request() would. REQ_FLUSH handling logic including
process_flush() is dropped.
* There's no reason for queue_io() and dm_wq_work() write lock
dm->io_lock. queue_io() now only uses md->deferred_lock and
dm_wq_work() read locks dm->io_lock.
* bio's no longer need to be queued on the deferred list while a flush
is in progress making DMF_QUEUE_IO_TO_THREAD unncessary. Drop it.
This avoids stalling the device during flushes and simplifies the
implementation.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
drivers/md/dm.c | 157 ++++++++++++++++---------------------------------------
1 files changed, 45 insertions(+), 112 deletions(-)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 65114e4..2011704 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -110,7 +110,6 @@ EXPORT_SYMBOL_GPL(dm_get_rq_mapinfo);
#define DMF_FREEING 3
#define DMF_DELETING 4
#define DMF_NOFLUSH_SUSPENDING 5
-#define DMF_QUEUE_IO_TO_THREAD 6
/*
* Work processed by per-device workqueue.
@@ -144,11 +143,6 @@ struct mapped_device {
spinlock_t deferred_lock;
/*
- * An error from the flush request currently being processed.
- */
- int flush_error;
-
- /*
* Processing queue (flush)
*/
struct workqueue_struct *wq;
@@ -518,16 +512,10 @@ static void end_io_acct(struct dm_io *io)
*/
static void queue_io(struct mapped_device *md, struct bio *bio)
{
- down_write(&md->io_lock);
-
spin_lock_irq(&md->deferred_lock);
bio_list_add(&md->deferred, bio);
spin_unlock_irq(&md->deferred_lock);
-
- if (!test_and_set_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags))
- queue_work(md->wq, &md->work);
-
- up_write(&md->io_lock);
+ queue_work(md->wq, &md->work);
}
/*
@@ -615,11 +603,9 @@ static void dec_pending(struct dm_io *io, int error)
* Target requested pushing back the I/O.
*/
spin_lock_irqsave(&md->deferred_lock, flags);
- if (__noflush_suspending(md)) {
- if (!(io->bio->bi_rw & REQ_FLUSH))
- bio_list_add_head(&md->deferred,
- io->bio);
- } else
+ if (__noflush_suspending(md))
+ bio_list_add_head(&md->deferred, io->bio);
+ else
/* noflush suspend was interrupted. */
io->error = -EIO;
spin_unlock_irqrestore(&md->deferred_lock, flags);
@@ -627,26 +613,22 @@ static void dec_pending(struct dm_io *io, int error)
io_error = io->error;
bio = io->bio;
+ end_io_acct(io);
+ free_io(md, io);
+
+ if (io_error == DM_ENDIO_REQUEUE)
+ return;
- if (bio->bi_rw & REQ_FLUSH) {
+ if (!(bio->bi_rw & REQ_FLUSH) || !bio->bi_size) {
+ trace_block_bio_complete(md->queue, bio);
+ bio_endio(bio, io_error);
+ } else {
/*
- * There can be just one flush request so we use
- * a per-device variable for error reporting.
- * Note that you can't touch the bio after end_io_acct
+ * Preflush done for flush with data, reissue
+ * without REQ_FLUSH.
*/
- if (!md->flush_error)
- md->flush_error = io_error;
- end_io_acct(io);
- free_io(md, io);
- } else {
- end_io_acct(io);
- free_io(md, io);
-
- if (io_error != DM_ENDIO_REQUEUE) {
- trace_block_bio_complete(md->queue, bio);
-
- bio_endio(bio, io_error);
- }
+ bio->bi_rw &= ~REQ_FLUSH;
+ queue_io(md, bio);
}
}
}
@@ -1298,21 +1280,17 @@ static int __clone_and_map(struct clone_info *ci)
*/
static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
{
+ bool is_flush = bio->bi_rw & REQ_FLUSH;
struct clone_info ci;
int error = 0;
ci.map = dm_get_live_table(md);
if (unlikely(!ci.map)) {
- if (!(bio->bi_rw & REQ_FLUSH))
- bio_io_error(bio);
- else
- if (!md->flush_error)
- md->flush_error = -EIO;
+ bio_io_error(bio);
return;
}
ci.md = md;
- ci.bio = bio;
ci.io = alloc_io(md);
ci.io->error = 0;
atomic_set(&ci.io->io_count, 1);
@@ -1320,18 +1298,19 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
ci.io->md = md;
spin_lock_init(&ci.io->endio_lock);
ci.sector = bio->bi_sector;
- if (!(bio->bi_rw & REQ_FLUSH))
+ ci.idx = bio->bi_idx;
+
+ if (!is_flush) {
+ ci.bio = bio;
ci.sector_count = bio_sectors(bio);
- else {
- /* all FLUSH bio's reaching here should be empty */
- WARN_ON_ONCE(bio_has_data(bio));
+ } else {
+ ci.bio = &ci.md->flush_bio;
ci.sector_count = 1;
}
- ci.idx = bio->bi_idx;
start_io_acct(ci.io);
while (ci.sector_count && !error) {
- if (!(bio->bi_rw & REQ_FLUSH))
+ if (!is_flush)
error = __clone_and_map(&ci);
else
error = __clone_and_map_flush(&ci);
@@ -1419,22 +1398,14 @@ static int _dm_request(struct request_queue *q, struct bio *bio)
part_stat_add(cpu, &dm_disk(md)->part0, sectors[rw], bio_sectors(bio));
part_stat_unlock();
- /*
- * If we're suspended or the thread is processing flushes
- * we have to queue this io for later.
- */
- if (unlikely(test_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags)) ||
- (bio->bi_rw & REQ_FLUSH)) {
+ /* if we're suspended, we have to queue this io for later */
+ if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) {
up_read(&md->io_lock);
- if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) &&
- bio_rw(bio) == READA) {
+ if (bio_rw(bio) != READA)
+ queue_io(md, bio);
+ else
bio_io_error(bio);
- return 0;
- }
-
- queue_io(md, bio);
-
return 0;
}
@@ -1923,6 +1894,10 @@ static struct mapped_device *alloc_dev(int minor)
if (!md->bdev)
goto bad_bdev;
+ bio_init(&md->flush_bio);
+ md->flush_bio.bi_bdev = md->bdev;
+ md->flush_bio.bi_rw = WRITE_FLUSH;
+
/* Populate the mapping, nobody knows we exist yet */
spin_lock(&_minor_lock);
old_md = idr_replace(&_minor_idr, md, minor);
@@ -2313,37 +2288,6 @@ static int dm_wait_for_completion(struct mapped_device *md, int interruptible)
return r;
}
-static void process_flush(struct mapped_device *md, struct bio *bio)
-{
- md->flush_error = 0;
-
- /* handle REQ_FLUSH */
- dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
-
- bio_init(&md->flush_bio);
- md->flush_bio.bi_bdev = md->bdev;
- md->flush_bio.bi_rw = WRITE_FLUSH;
- __split_and_process_bio(md, &md->flush_bio);
-
- dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
-
- /* if it's an empty flush or the preflush failed, we're done */
- if (!bio_has_data(bio) || md->flush_error) {
- if (md->flush_error != DM_ENDIO_REQUEUE)
- bio_endio(bio, md->flush_error);
- else {
- spin_lock_irq(&md->deferred_lock);
- bio_list_add_head(&md->deferred, bio);
- spin_unlock_irq(&md->deferred_lock);
- }
- return;
- }
-
- /* issue data + REQ_FUA */
- bio->bi_rw &= ~REQ_FLUSH;
- __split_and_process_bio(md, bio);
-}
-
/*
* Process the deferred bios
*/
@@ -2353,33 +2297,27 @@ static void dm_wq_work(struct work_struct *work)
work);
struct bio *c;
- down_write(&md->io_lock);
+ down_read(&md->io_lock);
while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
spin_lock_irq(&md->deferred_lock);
c = bio_list_pop(&md->deferred);
spin_unlock_irq(&md->deferred_lock);
- if (!c) {
- clear_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags);
+ if (!c)
break;
- }
- up_write(&md->io_lock);
+ up_read(&md->io_lock);
if (dm_request_based(md))
generic_make_request(c);
- else {
- if (c->bi_rw & REQ_FLUSH)
- process_flush(md, c);
- else
- __split_and_process_bio(md, c);
- }
+ else
+ __split_and_process_bio(md, c);
- down_write(&md->io_lock);
+ down_read(&md->io_lock);
}
- up_write(&md->io_lock);
+ up_read(&md->io_lock);
}
static void dm_queue_flush(struct mapped_device *md)
@@ -2511,17 +2449,12 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
*
* To get all processes out of __split_and_process_bio in dm_request,
* we take the write lock. To prevent any process from reentering
- * __split_and_process_bio from dm_request, we set
- * DMF_QUEUE_IO_TO_THREAD.
- *
- * To quiesce the thread (dm_wq_work), we set DMF_BLOCK_IO_FOR_SUSPEND
- * and call flush_workqueue(md->wq). flush_workqueue will wait until
- * dm_wq_work exits and DMF_BLOCK_IO_FOR_SUSPEND will prevent any
- * further calls to __split_and_process_bio from dm_wq_work.
+ * __split_and_process_bio from dm_request and quiesce the thread
+ * (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call
+ * flush_workqueue(md->wq).
*/
down_write(&md->io_lock);
set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
- set_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags);
up_write(&md->io_lock);
/*
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 25/41] dm: relax ordering of bio-based flush implementation
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
Unlike REQ_HARDBARRIER, REQ_FLUSH/FUA doesn't mandate any ordering
against other bio's. This patch relaxes ordering around flushes.
* A flush bio is no longer deferred to workqueue directly. It's
processed like other bio's but __split_and_process_bio() uses
md->flush_bio as the clone source. md->flush_bio is initialized to
empty flush during md initialization and shared for all flushes.
* As a flush bio now travels through the same execution path as other
bio's, there's no need for dedicated error handling path either. It
can use the same error handling path in dec_pending(). Dedicated
error handling removed along with md->flush_error.
* When dec_pending() detects that a flush has completed, it checks
whether the original bio has data. If so, the bio is queued to the
deferred list w/ REQ_FLUSH cleared; otherwise, it's completed.
* As flush sequencing is handled in the usual issue/completion path,
dm_wq_work() no longer needs to handle flushes differently. Now its
only responsibility is re-issuing deferred bio's the same way as
_dm_request() would. REQ_FLUSH handling logic including
process_flush() is dropped.
* There's no reason for queue_io() and dm_wq_work() write lock
dm->io_lock. queue_io() now only uses md->deferred_lock and
dm_wq_work() read locks dm->io_lock.
* bio's no longer need to be queued on the deferred list while a flush
is in progress making DMF_QUEUE_IO_TO_THREAD unncessary. Drop it.
This avoids stalling the device during flushes and simplifies the
implementation.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
drivers/md/dm.c | 157 ++++++++++++++++---------------------------------------
1 files changed, 45 insertions(+), 112 deletions(-)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 65114e4..2011704 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -110,7 +110,6 @@ EXPORT_SYMBOL_GPL(dm_get_rq_mapinfo);
#define DMF_FREEING 3
#define DMF_DELETING 4
#define DMF_NOFLUSH_SUSPENDING 5
-#define DMF_QUEUE_IO_TO_THREAD 6
/*
* Work processed by per-device workqueue.
@@ -144,11 +143,6 @@ struct mapped_device {
spinlock_t deferred_lock;
/*
- * An error from the flush request currently being processed.
- */
- int flush_error;
-
- /*
* Processing queue (flush)
*/
struct workqueue_struct *wq;
@@ -518,16 +512,10 @@ static void end_io_acct(struct dm_io *io)
*/
static void queue_io(struct mapped_device *md, struct bio *bio)
{
- down_write(&md->io_lock);
-
spin_lock_irq(&md->deferred_lock);
bio_list_add(&md->deferred, bio);
spin_unlock_irq(&md->deferred_lock);
-
- if (!test_and_set_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags))
- queue_work(md->wq, &md->work);
-
- up_write(&md->io_lock);
+ queue_work(md->wq, &md->work);
}
/*
@@ -615,11 +603,9 @@ static void dec_pending(struct dm_io *io, int error)
* Target requested pushing back the I/O.
*/
spin_lock_irqsave(&md->deferred_lock, flags);
- if (__noflush_suspending(md)) {
- if (!(io->bio->bi_rw & REQ_FLUSH))
- bio_list_add_head(&md->deferred,
- io->bio);
- } else
+ if (__noflush_suspending(md))
+ bio_list_add_head(&md->deferred, io->bio);
+ else
/* noflush suspend was interrupted. */
io->error = -EIO;
spin_unlock_irqrestore(&md->deferred_lock, flags);
@@ -627,26 +613,22 @@ static void dec_pending(struct dm_io *io, int error)
io_error = io->error;
bio = io->bio;
+ end_io_acct(io);
+ free_io(md, io);
+
+ if (io_error == DM_ENDIO_REQUEUE)
+ return;
- if (bio->bi_rw & REQ_FLUSH) {
+ if (!(bio->bi_rw & REQ_FLUSH) || !bio->bi_size) {
+ trace_block_bio_complete(md->queue, bio);
+ bio_endio(bio, io_error);
+ } else {
/*
- * There can be just one flush request so we use
- * a per-device variable for error reporting.
- * Note that you can't touch the bio after end_io_acct
+ * Preflush done for flush with data, reissue
+ * without REQ_FLUSH.
*/
- if (!md->flush_error)
- md->flush_error = io_error;
- end_io_acct(io);
- free_io(md, io);
- } else {
- end_io_acct(io);
- free_io(md, io);
-
- if (io_error != DM_ENDIO_REQUEUE) {
- trace_block_bio_complete(md->queue, bio);
-
- bio_endio(bio, io_error);
- }
+ bio->bi_rw &= ~REQ_FLUSH;
+ queue_io(md, bio);
}
}
}
@@ -1298,21 +1280,17 @@ static int __clone_and_map(struct clone_info *ci)
*/
static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
{
+ bool is_flush = bio->bi_rw & REQ_FLUSH;
struct clone_info ci;
int error = 0;
ci.map = dm_get_live_table(md);
if (unlikely(!ci.map)) {
- if (!(bio->bi_rw & REQ_FLUSH))
- bio_io_error(bio);
- else
- if (!md->flush_error)
- md->flush_error = -EIO;
+ bio_io_error(bio);
return;
}
ci.md = md;
- ci.bio = bio;
ci.io = alloc_io(md);
ci.io->error = 0;
atomic_set(&ci.io->io_count, 1);
@@ -1320,18 +1298,19 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
ci.io->md = md;
spin_lock_init(&ci.io->endio_lock);
ci.sector = bio->bi_sector;
- if (!(bio->bi_rw & REQ_FLUSH))
+ ci.idx = bio->bi_idx;
+
+ if (!is_flush) {
+ ci.bio = bio;
ci.sector_count = bio_sectors(bio);
- else {
- /* all FLUSH bio's reaching here should be empty */
- WARN_ON_ONCE(bio_has_data(bio));
+ } else {
+ ci.bio = &ci.md->flush_bio;
ci.sector_count = 1;
}
- ci.idx = bio->bi_idx;
start_io_acct(ci.io);
while (ci.sector_count && !error) {
- if (!(bio->bi_rw & REQ_FLUSH))
+ if (!is_flush)
error = __clone_and_map(&ci);
else
error = __clone_and_map_flush(&ci);
@@ -1419,22 +1398,14 @@ static int _dm_request(struct request_queue *q, struct bio *bio)
part_stat_add(cpu, &dm_disk(md)->part0, sectors[rw], bio_sectors(bio));
part_stat_unlock();
- /*
- * If we're suspended or the thread is processing flushes
- * we have to queue this io for later.
- */
- if (unlikely(test_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags)) ||
- (bio->bi_rw & REQ_FLUSH)) {
+ /* if we're suspended, we have to queue this io for later */
+ if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) {
up_read(&md->io_lock);
- if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) &&
- bio_rw(bio) == READA) {
+ if (bio_rw(bio) != READA)
+ queue_io(md, bio);
+ else
bio_io_error(bio);
- return 0;
- }
-
- queue_io(md, bio);
-
return 0;
}
@@ -1923,6 +1894,10 @@ static struct mapped_device *alloc_dev(int minor)
if (!md->bdev)
goto bad_bdev;
+ bio_init(&md->flush_bio);
+ md->flush_bio.bi_bdev = md->bdev;
+ md->flush_bio.bi_rw = WRITE_FLUSH;
+
/* Populate the mapping, nobody knows we exist yet */
spin_lock(&_minor_lock);
old_md = idr_replace(&_minor_idr, md, minor);
@@ -2313,37 +2288,6 @@ static int dm_wait_for_completion(struct mapped_device *md, int interruptible)
return r;
}
-static void process_flush(struct mapped_device *md, struct bio *bio)
-{
- md->flush_error = 0;
-
- /* handle REQ_FLUSH */
- dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
-
- bio_init(&md->flush_bio);
- md->flush_bio.bi_bdev = md->bdev;
- md->flush_bio.bi_rw = WRITE_FLUSH;
- __split_and_process_bio(md, &md->flush_bio);
-
- dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
-
- /* if it's an empty flush or the preflush failed, we're done */
- if (!bio_has_data(bio) || md->flush_error) {
- if (md->flush_error != DM_ENDIO_REQUEUE)
- bio_endio(bio, md->flush_error);
- else {
- spin_lock_irq(&md->deferred_lock);
- bio_list_add_head(&md->deferred, bio);
- spin_unlock_irq(&md->deferred_lock);
- }
- return;
- }
-
- /* issue data + REQ_FUA */
- bio->bi_rw &= ~REQ_FLUSH;
- __split_and_process_bio(md, bio);
-}
-
/*
* Process the deferred bios
*/
@@ -2353,33 +2297,27 @@ static void dm_wq_work(struct work_struct *work)
work);
struct bio *c;
- down_write(&md->io_lock);
+ down_read(&md->io_lock);
while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
spin_lock_irq(&md->deferred_lock);
c = bio_list_pop(&md->deferred);
spin_unlock_irq(&md->deferred_lock);
- if (!c) {
- clear_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags);
+ if (!c)
break;
- }
- up_write(&md->io_lock);
+ up_read(&md->io_lock);
if (dm_request_based(md))
generic_make_request(c);
- else {
- if (c->bi_rw & REQ_FLUSH)
- process_flush(md, c);
- else
- __split_and_process_bio(md, c);
- }
+ else
+ __split_and_process_bio(md, c);
- down_write(&md->io_lock);
+ down_read(&md->io_lock);
}
- up_write(&md->io_lock);
+ up_read(&md->io_lock);
}
static void dm_queue_flush(struct mapped_device *md)
@@ -2511,17 +2449,12 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
*
* To get all processes out of __split_and_process_bio in dm_request,
* we take the write lock. To prevent any process from reentering
- * __split_and_process_bio from dm_request, we set
- * DMF_QUEUE_IO_TO_THREAD.
- *
- * To quiesce the thread (dm_wq_work), we set DMF_BLOCK_IO_FOR_SUSPEND
- * and call flush_workqueue(md->wq). flush_workqueue will wait until
- * dm_wq_work exits and DMF_BLOCK_IO_FOR_SUSPEND will prevent any
- * further calls to __split_and_process_bio from dm_wq_work.
+ * __split_and_process_bio from dm_request and quiesce the thread
+ * (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call
+ * flush_workqueue(md->wq).
*/
down_write(&md->io_lock);
set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
- set_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags);
up_write(&md->io_lock);
/*
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 25/41] dm: relax ordering of bio-based flush implementation
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo
Unlike REQ_HARDBARRIER, REQ_FLUSH/FUA doesn't mandate any ordering
against other bio's. This patch relaxes ordering around flushes.
* A flush bio is no longer deferred to workqueue directly. It's
processed like other bio's but __split_and_process_bio() uses
md->flush_bio as the clone source. md->flush_bio is initialized to
empty flush during md initialization and shared for all flushes.
* As a flush bio now travels through the same execution path as other
bio's, there's no need for dedicated error handling path either. It
can use the same error handling path in dec_pending(). Dedicated
error handling removed along with md->flush_error.
* When dec_pending() detects that a flush has completed, it checks
whether the original bio has data. If so, the bio is queued to the
deferred list w/ REQ_FLUSH cleared; otherwise, it's completed.
* As flush sequencing is handled in the usual issue/completion path,
dm_wq_work() no longer needs to handle flushes differently. Now its
only responsibility is re-issuing deferred bio's the same way as
_dm_request() would. REQ_FLUSH handling logic including
process_flush() is dropped.
* There's no reason for queue_io() and dm_wq_work() write lock
dm->io_lock. queue_io() now only uses md->deferred_lock and
dm_wq_work() read locks dm->io_lock.
* bio's no longer need to be queued on the deferred list while a flush
is in progress making DMF_QUEUE_IO_TO_THREAD unncessary. Drop it.
This avoids stalling the device during flushes and simplifies the
implementation.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
drivers/md/dm.c | 157 ++++++++++++++++---------------------------------------
1 files changed, 45 insertions(+), 112 deletions(-)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 65114e4..2011704 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -110,7 +110,6 @@ EXPORT_SYMBOL_GPL(dm_get_rq_mapinfo);
#define DMF_FREEING 3
#define DMF_DELETING 4
#define DMF_NOFLUSH_SUSPENDING 5
-#define DMF_QUEUE_IO_TO_THREAD 6
/*
* Work processed by per-device workqueue.
@@ -144,11 +143,6 @@ struct mapped_device {
spinlock_t deferred_lock;
/*
- * An error from the flush request currently being processed.
- */
- int flush_error;
-
- /*
* Processing queue (flush)
*/
struct workqueue_struct *wq;
@@ -518,16 +512,10 @@ static void end_io_acct(struct dm_io *io)
*/
static void queue_io(struct mapped_device *md, struct bio *bio)
{
- down_write(&md->io_lock);
-
spin_lock_irq(&md->deferred_lock);
bio_list_add(&md->deferred, bio);
spin_unlock_irq(&md->deferred_lock);
-
- if (!test_and_set_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags))
- queue_work(md->wq, &md->work);
-
- up_write(&md->io_lock);
+ queue_work(md->wq, &md->work);
}
/*
@@ -615,11 +603,9 @@ static void dec_pending(struct dm_io *io, int error)
* Target requested pushing back the I/O.
*/
spin_lock_irqsave(&md->deferred_lock, flags);
- if (__noflush_suspending(md)) {
- if (!(io->bio->bi_rw & REQ_FLUSH))
- bio_list_add_head(&md->deferred,
- io->bio);
- } else
+ if (__noflush_suspending(md))
+ bio_list_add_head(&md->deferred, io->bio);
+ else
/* noflush suspend was interrupted. */
io->error = -EIO;
spin_unlock_irqrestore(&md->deferred_lock, flags);
@@ -627,26 +613,22 @@ static void dec_pending(struct dm_io *io, int error)
io_error = io->error;
bio = io->bio;
+ end_io_acct(io);
+ free_io(md, io);
+
+ if (io_error == DM_ENDIO_REQUEUE)
+ return;
- if (bio->bi_rw & REQ_FLUSH) {
+ if (!(bio->bi_rw & REQ_FLUSH) || !bio->bi_size) {
+ trace_block_bio_complete(md->queue, bio);
+ bio_endio(bio, io_error);
+ } else {
/*
- * There can be just one flush request so we use
- * a per-device variable for error reporting.
- * Note that you can't touch the bio after end_io_acct
+ * Preflush done for flush with data, reissue
+ * without REQ_FLUSH.
*/
- if (!md->flush_error)
- md->flush_error = io_error;
- end_io_acct(io);
- free_io(md, io);
- } else {
- end_io_acct(io);
- free_io(md, io);
-
- if (io_error != DM_ENDIO_REQUEUE) {
- trace_block_bio_complete(md->queue, bio);
-
- bio_endio(bio, io_error);
- }
+ bio->bi_rw &= ~REQ_FLUSH;
+ queue_io(md, bio);
}
}
}
@@ -1298,21 +1280,17 @@ static int __clone_and_map(struct clone_info *ci)
*/
static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
{
+ bool is_flush = bio->bi_rw & REQ_FLUSH;
struct clone_info ci;
int error = 0;
ci.map = dm_get_live_table(md);
if (unlikely(!ci.map)) {
- if (!(bio->bi_rw & REQ_FLUSH))
- bio_io_error(bio);
- else
- if (!md->flush_error)
- md->flush_error = -EIO;
+ bio_io_error(bio);
return;
}
ci.md = md;
- ci.bio = bio;
ci.io = alloc_io(md);
ci.io->error = 0;
atomic_set(&ci.io->io_count, 1);
@@ -1320,18 +1298,19 @@ static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
ci.io->md = md;
spin_lock_init(&ci.io->endio_lock);
ci.sector = bio->bi_sector;
- if (!(bio->bi_rw & REQ_FLUSH))
+ ci.idx = bio->bi_idx;
+
+ if (!is_flush) {
+ ci.bio = bio;
ci.sector_count = bio_sectors(bio);
- else {
- /* all FLUSH bio's reaching here should be empty */
- WARN_ON_ONCE(bio_has_data(bio));
+ } else {
+ ci.bio = &ci.md->flush_bio;
ci.sector_count = 1;
}
- ci.idx = bio->bi_idx;
start_io_acct(ci.io);
while (ci.sector_count && !error) {
- if (!(bio->bi_rw & REQ_FLUSH))
+ if (!is_flush)
error = __clone_and_map(&ci);
else
error = __clone_and_map_flush(&ci);
@@ -1419,22 +1398,14 @@ static int _dm_request(struct request_queue *q, struct bio *bio)
part_stat_add(cpu, &dm_disk(md)->part0, sectors[rw], bio_sectors(bio));
part_stat_unlock();
- /*
- * If we're suspended or the thread is processing flushes
- * we have to queue this io for later.
- */
- if (unlikely(test_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags)) ||
- (bio->bi_rw & REQ_FLUSH)) {
+ /* if we're suspended, we have to queue this io for later */
+ if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) {
up_read(&md->io_lock);
- if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) &&
- bio_rw(bio) == READA) {
+ if (bio_rw(bio) != READA)
+ queue_io(md, bio);
+ else
bio_io_error(bio);
- return 0;
- }
-
- queue_io(md, bio);
-
return 0;
}
@@ -1923,6 +1894,10 @@ static struct mapped_device *alloc_dev(int minor)
if (!md->bdev)
goto bad_bdev;
+ bio_init(&md->flush_bio);
+ md->flush_bio.bi_bdev = md->bdev;
+ md->flush_bio.bi_rw = WRITE_FLUSH;
+
/* Populate the mapping, nobody knows we exist yet */
spin_lock(&_minor_lock);
old_md = idr_replace(&_minor_idr, md, minor);
@@ -2313,37 +2288,6 @@ static int dm_wait_for_completion(struct mapped_device *md, int interruptible)
return r;
}
-static void process_flush(struct mapped_device *md, struct bio *bio)
-{
- md->flush_error = 0;
-
- /* handle REQ_FLUSH */
- dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
-
- bio_init(&md->flush_bio);
- md->flush_bio.bi_bdev = md->bdev;
- md->flush_bio.bi_rw = WRITE_FLUSH;
- __split_and_process_bio(md, &md->flush_bio);
-
- dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
-
- /* if it's an empty flush or the preflush failed, we're done */
- if (!bio_has_data(bio) || md->flush_error) {
- if (md->flush_error != DM_ENDIO_REQUEUE)
- bio_endio(bio, md->flush_error);
- else {
- spin_lock_irq(&md->deferred_lock);
- bio_list_add_head(&md->deferred, bio);
- spin_unlock_irq(&md->deferred_lock);
- }
- return;
- }
-
- /* issue data + REQ_FUA */
- bio->bi_rw &= ~REQ_FLUSH;
- __split_and_process_bio(md, bio);
-}
-
/*
* Process the deferred bios
*/
@@ -2353,33 +2297,27 @@ static void dm_wq_work(struct work_struct *work)
work);
struct bio *c;
- down_write(&md->io_lock);
+ down_read(&md->io_lock);
while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
spin_lock_irq(&md->deferred_lock);
c = bio_list_pop(&md->deferred);
spin_unlock_irq(&md->deferred_lock);
- if (!c) {
- clear_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags);
+ if (!c)
break;
- }
- up_write(&md->io_lock);
+ up_read(&md->io_lock);
if (dm_request_based(md))
generic_make_request(c);
- else {
- if (c->bi_rw & REQ_FLUSH)
- process_flush(md, c);
- else
- __split_and_process_bio(md, c);
- }
+ else
+ __split_and_process_bio(md, c);
- down_write(&md->io_lock);
+ down_read(&md->io_lock);
}
- up_write(&md->io_lock);
+ up_read(&md->io_lock);
}
static void dm_queue_flush(struct mapped_device *md)
@@ -2511,17 +2449,12 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
*
* To get all processes out of __split_and_process_bio in dm_request,
* we take the write lock. To prevent any process from reentering
- * __split_and_process_bio from dm_request, we set
- * DMF_QUEUE_IO_TO_THREAD.
- *
- * To quiesce the thread (dm_wq_work), we set DMF_BLOCK_IO_FOR_SUSPEND
- * and call flush_workqueue(md->wq). flush_workqueue will wait until
- * dm_wq_work exits and DMF_BLOCK_IO_FOR_SUSPEND will prevent any
- * further calls to __split_and_process_bio from dm_wq_work.
+ * __split_and_process_bio from dm_request and quiesce the thread
+ * (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call
+ * flush_workqueue(md->wq).
*/
down_write(&md->io_lock);
set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
- set_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags);
up_write(&md->io_lock);
/*
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 26/41] dm: fix locking context in queue_io()
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Jun'ichi Nomura, Tejun Heo
From: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Now queue_io() is called from dec_pending(), which may be called with
interrupts disabled, so queue_io() must not enable interrupts
unconditionally and must save/restore the current interrupts status.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
drivers/md/dm.c | 6 ++++--
1 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 2011704..cd2f7e7 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -512,9 +512,11 @@ static void end_io_acct(struct dm_io *io)
*/
static void queue_io(struct mapped_device *md, struct bio *bio)
{
- spin_lock_irq(&md->deferred_lock);
+ unsigned long flags;
+
+ spin_lock_irqsave(&md->deferred_lock, flags);
bio_list_add(&md->deferred, bio);
- spin_unlock_irq(&md->deferred_lock);
+ spin_unlock_irqrestore(&md->deferred_lock, flags);
queue_work(md->wq, &md->work);
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 26/41] dm: fix locking context in queue_io()
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Jun'ichi Nomura, Tejun Heo
From: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Now queue_io() is called from dec_pending(), which may be called with
interrupts disabled, so queue_io() must not enable interrupts
unconditionally and must save/restore the current interrupts status.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
drivers/md/dm.c | 6 ++++--
1 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 2011704..cd2f7e7 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -512,9 +512,11 @@ static void end_io_acct(struct dm_io *io)
*/
static void queue_io(struct mapped_device *md, struct bio *bio)
{
- spin_lock_irq(&md->deferred_lock);
+ unsigned long flags;
+
+ spin_lock_irqsave(&md->deferred_lock, flags);
bio_list_add(&md->deferred, bio);
- spin_unlock_irq(&md->deferred_lock);
+ spin_unlock_irqrestore(&md->deferred_lock, flags);
queue_work(md->wq, &md->work);
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 26/41] dm: fix locking context in queue_io()
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Jun'ichi Nomura, Tejun Heo
From: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Now queue_io() is called from dec_pending(), which may be called with
interrupts disabled, so queue_io() must not enable interrupts
unconditionally and must save/restore the current interrupts status.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
drivers/md/dm.c | 6 ++++--
1 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 2011704..cd2f7e7 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -512,9 +512,11 @@ static void end_io_acct(struct dm_io *io)
*/
static void queue_io(struct mapped_device *md, struct bio *bio)
{
- spin_lock_irq(&md->deferred_lock);
+ unsigned long flags;
+
+ spin_lock_irqsave(&md->deferred_lock, flags);
bio_list_add(&md->deferred, bio);
- spin_unlock_irq(&md->deferred_lock);
+ spin_unlock_irqrestore(&md->deferred_lock, flags);
queue_work(md->wq, &md->work);
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 27/41] block: pass gfp_mask and flags to sb_issue_discard
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
We'll need to get rid of the BLKDEV_IFL_BARRIER flag, and to facilitate
that and to make the interface less confusing pass all flags explicitly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/ext4/mballoc.c | 3 ++-
fs/fat/fatent.c | 4 +++-
include/linux/blkdev.h | 11 +++++------
3 files changed, 10 insertions(+), 8 deletions(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 4b4ad4b..df44b34 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2566,7 +2566,8 @@ static inline void ext4_issue_discard(struct super_block *sb,
discard_block = block + ext4_group_first_block_no(sb, block_group);
trace_ext4_discard_blocks(sb,
(unsigned long long) discard_block, count);
- ret = sb_issue_discard(sb, discard_block, count);
+ ret = sb_issue_discard(sb, discard_block, count, GFP_NOFS,
+ BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
if (ret == EOPNOTSUPP) {
ext4_warning(sb, "discard not supported, disabling");
clear_opt(EXT4_SB(sb)->s_mount_opt, DISCARD);
diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c
index 81184d3..3a56a82 100644
--- a/fs/fat/fatent.c
+++ b/fs/fat/fatent.c
@@ -577,7 +577,9 @@ int fat_free_clusters(struct inode *inode, int cluster)
sb_issue_discard(sb,
fat_clus_to_blknr(sbi, first_cl),
- nr_clus * sbi->sec_per_clus);
+ nr_clus * sbi->sec_per_clus,
+ GFP_NOFS,
+ BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
first_cl = cluster;
}
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 8ef705f..6b305eb 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -881,13 +881,12 @@ extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
-static inline int sb_issue_discard(struct super_block *sb,
- sector_t block, sector_t nr_blocks)
+static inline int sb_issue_discard(struct super_block *sb, sector_t block,
+ sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
{
- block <<= (sb->s_blocksize_bits - 9);
- nr_blocks <<= (sb->s_blocksize_bits - 9);
- return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_NOFS,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
+ nr_blocks << (sb->s_blocksize_bits - 9),
+ gfp_mask, flags);
}
extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 27/41] block: pass gfp_mask and flags to sb_issue_discard
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
We'll need to get rid of the BLKDEV_IFL_BARRIER flag, and to facilitate
that and to make the interface less confusing pass all flags explicitly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/ext4/mballoc.c | 3 ++-
fs/fat/fatent.c | 4 +++-
include/linux/blkdev.h | 11 +++++------
3 files changed, 10 insertions(+), 8 deletions(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 4b4ad4b..df44b34 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2566,7 +2566,8 @@ static inline void ext4_issue_discard(struct super_block *sb,
discard_block = block + ext4_group_first_block_no(sb, block_group);
trace_ext4_discard_blocks(sb,
(unsigned long long) discard_block, count);
- ret = sb_issue_discard(sb, discard_block, count);
+ ret = sb_issue_discard(sb, discard_block, count, GFP_NOFS,
+ BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
if (ret == EOPNOTSUPP) {
ext4_warning(sb, "discard not supported, disabling");
clear_opt(EXT4_SB(sb)->s_mount_opt, DISCARD);
diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c
index 81184d3..3a56a82 100644
--- a/fs/fat/fatent.c
+++ b/fs/fat/fatent.c
@@ -577,7 +577,9 @@ int fat_free_clusters(struct inode *inode, int cluster)
sb_issue_discard(sb,
fat_clus_to_blknr(sbi, first_cl),
- nr_clus * sbi->sec_per_clus);
+ nr_clus * sbi->sec_per_clus,
+ GFP_NOFS,
+ BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
first_cl = cluster;
}
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 8ef705f..6b305eb 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -881,13 +881,12 @@ extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
-static inline int sb_issue_discard(struct super_block *sb,
- sector_t block, sector_t nr_blocks)
+static inline int sb_issue_discard(struct super_block *sb, sector_t block,
+ sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
{
- block <<= (sb->s_blocksize_bits - 9);
- nr_blocks <<= (sb->s_blocksize_bits - 9);
- return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_NOFS,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
+ nr_blocks << (sb->s_blocksize_bits - 9),
+ gfp_mask, flags);
}
extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 27/41] block: pass gfp_mask and flags to sb_issue_discard
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
We'll need to get rid of the BLKDEV_IFL_BARRIER flag, and to facilitate
that and to make the interface less confusing pass all flags explicitly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/ext4/mballoc.c | 3 ++-
fs/fat/fatent.c | 4 +++-
include/linux/blkdev.h | 11 +++++------
3 files changed, 10 insertions(+), 8 deletions(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 4b4ad4b..df44b34 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2566,7 +2566,8 @@ static inline void ext4_issue_discard(struct super_block *sb,
discard_block = block + ext4_group_first_block_no(sb, block_group);
trace_ext4_discard_blocks(sb,
(unsigned long long) discard_block, count);
- ret = sb_issue_discard(sb, discard_block, count);
+ ret = sb_issue_discard(sb, discard_block, count, GFP_NOFS,
+ BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
if (ret == EOPNOTSUPP) {
ext4_warning(sb, "discard not supported, disabling");
clear_opt(EXT4_SB(sb)->s_mount_opt, DISCARD);
diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c
index 81184d3..3a56a82 100644
--- a/fs/fat/fatent.c
+++ b/fs/fat/fatent.c
@@ -577,7 +577,9 @@ int fat_free_clusters(struct inode *inode, int cluster)
sb_issue_discard(sb,
fat_clus_to_blknr(sbi, first_cl),
- nr_clus * sbi->sec_per_clus);
+ nr_clus * sbi->sec_per_clus,
+ GFP_NOFS,
+ BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
first_cl = cluster;
}
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 8ef705f..6b305eb 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -881,13 +881,12 @@ extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
-static inline int sb_issue_discard(struct super_block *sb,
- sector_t block, sector_t nr_blocks)
+static inline int sb_issue_discard(struct super_block *sb, sector_t block,
+ sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
{
- block <<= (sb->s_blocksize_bits - 9);
- nr_blocks <<= (sb->s_blocksize_bits - 9);
- return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_NOFS,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
+ nr_blocks << (sb->s_blocksize_bits - 9),
+ gfp_mask, flags);
}
extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 28/41] xfs: replace barriers with explicit flush / FUA usage
2010-09-03 10:29 ` Tejun Heo
` (37 preceding siblings ...)
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
Switch to the WRITE_FLUSH_FUA flag for log writes and remove the EOPNOTSUPP
detection for barriers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/xfs/linux-2.6/xfs_buf.c | 16 ++--------------
fs/xfs/linux-2.6/xfs_buf.h | 11 +----------
fs/xfs/linux-2.6/xfs_trace.h | 1 -
fs/xfs/xfs_log.c | 13 -------------
4 files changed, 3 insertions(+), 38 deletions(-)
diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index ea79072..b93ea33 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -929,19 +929,7 @@ xfs_buf_iodone_work(
xfs_buf_t *bp =
container_of(work, xfs_buf_t, b_iodone_work);
- /*
- * We can get an EOPNOTSUPP to ordered writes. Here we clear the
- * ordered flag and reissue them. Because we can't tell the higher
- * layers directly that they should not issue ordered I/O anymore, they
- * need to check if the _XFS_BARRIER_FAILED flag was set during I/O completion.
- */
- if ((bp->b_error == EOPNOTSUPP) &&
- (bp->b_flags & (XBF_ORDERED|XBF_ASYNC)) == (XBF_ORDERED|XBF_ASYNC)) {
- trace_xfs_buf_ordered_retry(bp, _RET_IP_);
- bp->b_flags &= ~XBF_ORDERED;
- bp->b_flags |= _XFS_BARRIER_FAILED;
- xfs_buf_iorequest(bp);
- } else if (bp->b_iodone)
+ if (bp->b_iodone)
(*(bp->b_iodone))(bp);
else if (bp->b_flags & XBF_ASYNC)
xfs_buf_relse(bp);
@@ -1200,7 +1188,7 @@ _xfs_buf_ioapply(
if (bp->b_flags & XBF_ORDERED) {
ASSERT(!(bp->b_flags & XBF_READ));
- rw = WRITE_BARRIER;
+ rw = WRITE_FLUSH_FUA;
} else if (bp->b_flags & XBF_LOG_BUFFER) {
ASSERT(!(bp->b_flags & XBF_READ_AHEAD));
bp->b_flags &= ~_XBF_RUN_QUEUES;
diff --git a/fs/xfs/linux-2.6/xfs_buf.h b/fs/xfs/linux-2.6/xfs_buf.h
index d072e5f..d533d64 100644
--- a/fs/xfs/linux-2.6/xfs_buf.h
+++ b/fs/xfs/linux-2.6/xfs_buf.h
@@ -86,14 +86,6 @@ typedef enum {
*/
#define _XBF_PAGE_LOCKED (1 << 22)
-/*
- * If we try a barrier write, but it fails we have to communicate
- * this to the upper layers. Unfortunately b_error gets overwritten
- * when the buffer is re-issued so we have to add another flag to
- * keep this information.
- */
-#define _XFS_BARRIER_FAILED (1 << 23)
-
typedef unsigned int xfs_buf_flags_t;
#define XFS_BUF_FLAGS \
@@ -114,8 +106,7 @@ typedef unsigned int xfs_buf_flags_t;
{ _XBF_PAGES, "PAGES" }, \
{ _XBF_RUN_QUEUES, "RUN_QUEUES" }, \
{ _XBF_DELWRI_Q, "DELWRI_Q" }, \
- { _XBF_PAGE_LOCKED, "PAGE_LOCKED" }, \
- { _XFS_BARRIER_FAILED, "BARRIER_FAILED" }
+ { _XBF_PAGE_LOCKED, "PAGE_LOCKED" }
typedef enum {
diff --git a/fs/xfs/linux-2.6/xfs_trace.h b/fs/xfs/linux-2.6/xfs_trace.h
index be5dffd..8fe311a 100644
--- a/fs/xfs/linux-2.6/xfs_trace.h
+++ b/fs/xfs/linux-2.6/xfs_trace.h
@@ -325,7 +325,6 @@ DEFINE_BUF_EVENT(xfs_buf_lock);
DEFINE_BUF_EVENT(xfs_buf_lock_done);
DEFINE_BUF_EVENT(xfs_buf_cond_lock);
DEFINE_BUF_EVENT(xfs_buf_unlock);
-DEFINE_BUF_EVENT(xfs_buf_ordered_retry);
DEFINE_BUF_EVENT(xfs_buf_iowait);
DEFINE_BUF_EVENT(xfs_buf_iowait_done);
DEFINE_BUF_EVENT(xfs_buf_delwri_queue);
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 33f718f..ba8e36e 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -917,19 +917,6 @@ xlog_iodone(xfs_buf_t *bp)
l = iclog->ic_log;
/*
- * If the _XFS_BARRIER_FAILED flag was set by a lower
- * layer, it means the underlying device no longer supports
- * barrier I/O. Warn loudly and turn off barriers.
- */
- if (bp->b_flags & _XFS_BARRIER_FAILED) {
- bp->b_flags &= ~_XFS_BARRIER_FAILED;
- l->l_mp->m_flags &= ~XFS_MOUNT_BARRIER;
- xfs_fs_cmn_err(CE_WARN, l->l_mp,
- "xlog_iodone: Barriers are no longer supported"
- " by device. Disabling barriers\n");
- }
-
- /*
* Race to shutdown the filesystem if we see an error.
*/
if (XFS_TEST_ERROR((XFS_BUF_GETERROR(bp)), l->l_mp,
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 28/41] xfs: replace barriers with explicit flush / FUA usage
2010-09-03 10:29 ` Tejun Heo
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
Switch to the WRITE_FLUSH_FUA flag for log writes and remove the EOPNOTSUPP
detection for barriers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/xfs/linux-2.6/xfs_buf.c | 16 ++--------------
fs/xfs/linux-2.6/xfs_buf.h | 11 +----------
fs/xfs/linux-2.6/xfs_trace.h | 1 -
fs/xfs/xfs_log.c | 13 -------------
4 files changed, 3 insertions(+), 38 deletions(-)
diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index ea79072..b93ea33 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -929,19 +929,7 @@ xfs_buf_iodone_work(
xfs_buf_t *bp =
container_of(work, xfs_buf_t, b_iodone_work);
- /*
- * We can get an EOPNOTSUPP to ordered writes. Here we clear the
- * ordered flag and reissue them. Because we can't tell the higher
- * layers directly that they should not issue ordered I/O anymore, they
- * need to check if the _XFS_BARRIER_FAILED flag was set during I/O completion.
- */
- if ((bp->b_error == EOPNOTSUPP) &&
- (bp->b_flags & (XBF_ORDERED|XBF_ASYNC)) == (XBF_ORDERED|XBF_ASYNC)) {
- trace_xfs_buf_ordered_retry(bp, _RET_IP_);
- bp->b_flags &= ~XBF_ORDERED;
- bp->b_flags |= _XFS_BARRIER_FAILED;
- xfs_buf_iorequest(bp);
- } else if (bp->b_iodone)
+ if (bp->b_iodone)
(*(bp->b_iodone))(bp);
else if (bp->b_flags & XBF_ASYNC)
xfs_buf_relse(bp);
@@ -1200,7 +1188,7 @@ _xfs_buf_ioapply(
if (bp->b_flags & XBF_ORDERED) {
ASSERT(!(bp->b_flags & XBF_READ));
- rw = WRITE_BARRIER;
+ rw = WRITE_FLUSH_FUA;
} else if (bp->b_flags & XBF_LOG_BUFFER) {
ASSERT(!(bp->b_flags & XBF_READ_AHEAD));
bp->b_flags &= ~_XBF_RUN_QUEUES;
diff --git a/fs/xfs/linux-2.6/xfs_buf.h b/fs/xfs/linux-2.6/xfs_buf.h
index d072e5f..d533d64 100644
--- a/fs/xfs/linux-2.6/xfs_buf.h
+++ b/fs/xfs/linux-2.6/xfs_buf.h
@@ -86,14 +86,6 @@ typedef enum {
*/
#define _XBF_PAGE_LOCKED (1 << 22)
-/*
- * If we try a barrier write, but it fails we have to communicate
- * this to the upper layers. Unfortunately b_error gets overwritten
- * when the buffer is re-issued so we have to add another flag to
- * keep this information.
- */
-#define _XFS_BARRIER_FAILED (1 << 23)
-
typedef unsigned int xfs_buf_flags_t;
#define XFS_BUF_FLAGS \
@@ -114,8 +106,7 @@ typedef unsigned int xfs_buf_flags_t;
{ _XBF_PAGES, "PAGES" }, \
{ _XBF_RUN_QUEUES, "RUN_QUEUES" }, \
{ _XBF_DELWRI_Q, "DELWRI_Q" }, \
- { _XBF_PAGE_LOCKED, "PAGE_LOCKED" }, \
- { _XFS_BARRIER_FAILED, "BARRIER_FAILED" }
+ { _XBF_PAGE_LOCKED, "PAGE_LOCKED" }
typedef enum {
diff --git a/fs/xfs/linux-2.6/xfs_trace.h b/fs/xfs/linux-2.6/xfs_trace.h
index be5dffd..8fe311a 100644
--- a/fs/xfs/linux-2.6/xfs_trace.h
+++ b/fs/xfs/linux-2.6/xfs_trace.h
@@ -325,7 +325,6 @@ DEFINE_BUF_EVENT(xfs_buf_lock);
DEFINE_BUF_EVENT(xfs_buf_lock_done);
DEFINE_BUF_EVENT(xfs_buf_cond_lock);
DEFINE_BUF_EVENT(xfs_buf_unlock);
-DEFINE_BUF_EVENT(xfs_buf_ordered_retry);
DEFINE_BUF_EVENT(xfs_buf_iowait);
DEFINE_BUF_EVENT(xfs_buf_iowait_done);
DEFINE_BUF_EVENT(xfs_buf_delwri_queue);
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 33f718f..ba8e36e 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -917,19 +917,6 @@ xlog_iodone(xfs_buf_t *bp)
l = iclog->ic_log;
/*
- * If the _XFS_BARRIER_FAILED flag was set by a lower
- * layer, it means the underlying device no longer supports
- * barrier I/O. Warn loudly and turn off barriers.
- */
- if (bp->b_flags & _XFS_BARRIER_FAILED) {
- bp->b_flags &= ~_XFS_BARRIER_FAILED;
- l->l_mp->m_flags &= ~XFS_MOUNT_BARRIER;
- xfs_fs_cmn_err(CE_WARN, l->l_mp,
- "xlog_iodone: Barriers are no longer supported"
- " by device. Disabling barriers\n");
- }
-
- /*
* Race to shutdown the filesystem if we see an error.
*/
if (XFS_TEST_ERROR((XFS_BUF_GETERROR(bp)), l->l_mp,
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 28/41] xfs: replace barriers with explicit flush / FUA usage
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
Switch to the WRITE_FLUSH_FUA flag for log writes and remove the EOPNOTSUPP
detection for barriers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/xfs/linux-2.6/xfs_buf.c | 16 ++--------------
fs/xfs/linux-2.6/xfs_buf.h | 11 +----------
fs/xfs/linux-2.6/xfs_trace.h | 1 -
fs/xfs/xfs_log.c | 13 -------------
4 files changed, 3 insertions(+), 38 deletions(-)
diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index ea79072..b93ea33 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -929,19 +929,7 @@ xfs_buf_iodone_work(
xfs_buf_t *bp =
container_of(work, xfs_buf_t, b_iodone_work);
- /*
- * We can get an EOPNOTSUPP to ordered writes. Here we clear the
- * ordered flag and reissue them. Because we can't tell the higher
- * layers directly that they should not issue ordered I/O anymore, they
- * need to check if the _XFS_BARRIER_FAILED flag was set during I/O completion.
- */
- if ((bp->b_error == EOPNOTSUPP) &&
- (bp->b_flags & (XBF_ORDERED|XBF_ASYNC)) == (XBF_ORDERED|XBF_ASYNC)) {
- trace_xfs_buf_ordered_retry(bp, _RET_IP_);
- bp->b_flags &= ~XBF_ORDERED;
- bp->b_flags |= _XFS_BARRIER_FAILED;
- xfs_buf_iorequest(bp);
- } else if (bp->b_iodone)
+ if (bp->b_iodone)
(*(bp->b_iodone))(bp);
else if (bp->b_flags & XBF_ASYNC)
xfs_buf_relse(bp);
@@ -1200,7 +1188,7 @@ _xfs_buf_ioapply(
if (bp->b_flags & XBF_ORDERED) {
ASSERT(!(bp->b_flags & XBF_READ));
- rw = WRITE_BARRIER;
+ rw = WRITE_FLUSH_FUA;
} else if (bp->b_flags & XBF_LOG_BUFFER) {
ASSERT(!(bp->b_flags & XBF_READ_AHEAD));
bp->b_flags &= ~_XBF_RUN_QUEUES;
diff --git a/fs/xfs/linux-2.6/xfs_buf.h b/fs/xfs/linux-2.6/xfs_buf.h
index d072e5f..d533d64 100644
--- a/fs/xfs/linux-2.6/xfs_buf.h
+++ b/fs/xfs/linux-2.6/xfs_buf.h
@@ -86,14 +86,6 @@ typedef enum {
*/
#define _XBF_PAGE_LOCKED (1 << 22)
-/*
- * If we try a barrier write, but it fails we have to communicate
- * this to the upper layers. Unfortunately b_error gets overwritten
- * when the buffer is re-issued so we have to add another flag to
- * keep this information.
- */
-#define _XFS_BARRIER_FAILED (1 << 23)
-
typedef unsigned int xfs_buf_flags_t;
#define XFS_BUF_FLAGS \
@@ -114,8 +106,7 @@ typedef unsigned int xfs_buf_flags_t;
{ _XBF_PAGES, "PAGES" }, \
{ _XBF_RUN_QUEUES, "RUN_QUEUES" }, \
{ _XBF_DELWRI_Q, "DELWRI_Q" }, \
- { _XBF_PAGE_LOCKED, "PAGE_LOCKED" }, \
- { _XFS_BARRIER_FAILED, "BARRIER_FAILED" }
+ { _XBF_PAGE_LOCKED, "PAGE_LOCKED" }
typedef enum {
diff --git a/fs/xfs/linux-2.6/xfs_trace.h b/fs/xfs/linux-2.6/xfs_trace.h
index be5dffd..8fe311a 100644
--- a/fs/xfs/linux-2.6/xfs_trace.h
+++ b/fs/xfs/linux-2.6/xfs_trace.h
@@ -325,7 +325,6 @@ DEFINE_BUF_EVENT(xfs_buf_lock);
DEFINE_BUF_EVENT(xfs_buf_lock_done);
DEFINE_BUF_EVENT(xfs_buf_cond_lock);
DEFINE_BUF_EVENT(xfs_buf_unlock);
-DEFINE_BUF_EVENT(xfs_buf_ordered_retry);
DEFINE_BUF_EVENT(xfs_buf_iowait);
DEFINE_BUF_EVENT(xfs_buf_iowait_done);
DEFINE_BUF_EVENT(xfs_buf_delwri_queue);
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 33f718f..ba8e36e 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -917,19 +917,6 @@ xlog_iodone(xfs_buf_t *bp)
l = iclog->ic_log;
/*
- * If the _XFS_BARRIER_FAILED flag was set by a lower
- * layer, it means the underlying device no longer supports
- * barrier I/O. Warn loudly and turn off barriers.
- */
- if (bp->b_flags & _XFS_BARRIER_FAILED) {
- bp->b_flags &= ~_XFS_BARRIER_FAILED;
- l->l_mp->m_flags &= ~XFS_MOUNT_BARRIER;
- xfs_fs_cmn_err(CE_WARN, l->l_mp,
- "xlog_iodone: Barriers are no longer supported"
- " by device. Disabling barriers\n");
- }
-
- /*
* Race to shutdown the filesystem if we see an error.
*/
if (XFS_TEST_ERROR((XFS_BUF_GETERROR(bp)), l->l_mp,
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 29/41] btrfs: replace barriers with explicit flush / FUA usage
2010-09-03 10:29 ` Tejun Heo
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
Switch to the WRITE_FLUSH_FUA flag for log writes, remove the EOPNOTSUPP
detection for barriers and stop setting the barrier flag for discards.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/btrfs/disk-io.c | 19 ++++---------------
fs/btrfs/extent-tree.c | 2 +-
fs/btrfs/volumes.c | 4 ----
fs/btrfs/volumes.h | 1 -
4 files changed, 5 insertions(+), 21 deletions(-)
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 64f1008..5e789f4 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2063,7 +2063,7 @@ static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
if (uptodate) {
set_buffer_uptodate(bh);
} else {
- if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
+ if (printk_ratelimit()) {
printk(KERN_WARNING "lost page write due to "
"I/O error on %s\n",
bdevname(bh->b_bdev, b));
@@ -2200,21 +2200,10 @@ static int write_dev_supers(struct btrfs_device *device,
bh->b_end_io = btrfs_end_buffer_write_sync;
}
- if (i == last_barrier && do_barriers && device->barriers) {
- ret = submit_bh(WRITE_BARRIER, bh);
- if (ret == -EOPNOTSUPP) {
- printk("btrfs: disabling barriers on dev %s\n",
- device->name);
- set_buffer_uptodate(bh);
- device->barriers = 0;
- /* one reference for submit_bh */
- get_bh(bh);
- lock_buffer(bh);
- ret = submit_bh(WRITE_SYNC, bh);
- }
- } else {
+ if (i == last_barrier && do_barriers)
+ ret = submit_bh(WRITE_FLUSH_FUA, bh);
+ else
ret = submit_bh(WRITE_SYNC, bh);
- }
if (ret)
errors++;
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 32d0940..43dc9ea 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1696,7 +1696,7 @@ static void btrfs_issue_discard(struct block_device *bdev,
u64 start, u64 len)
{
blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ BLKDEV_IFL_WAIT);
}
static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index dd318ff..e25e46a 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -398,7 +398,6 @@ static noinline int device_list_add(const char *path,
device->work.func = pending_bios_fn;
memcpy(device->uuid, disk_super->dev_item.uuid,
BTRFS_UUID_SIZE);
- device->barriers = 1;
spin_lock_init(&device->io_lock);
device->name = kstrdup(path, GFP_NOFS);
if (!device->name) {
@@ -462,7 +461,6 @@ static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
device->devid = orig_dev->devid;
device->work.func = pending_bios_fn;
memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
- device->barriers = 1;
spin_lock_init(&device->io_lock);
INIT_LIST_HEAD(&device->dev_list);
INIT_LIST_HEAD(&device->dev_alloc_list);
@@ -1489,7 +1487,6 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
trans = btrfs_start_transaction(root, 0);
lock_chunks(root);
- device->barriers = 1;
device->writeable = 1;
device->work.func = pending_bios_fn;
generate_random_uuid(device->uuid);
@@ -3084,7 +3081,6 @@ static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
return NULL;
list_add(&device->dev_list,
&fs_devices->devices);
- device->barriers = 1;
device->dev_root = root->fs_info->dev_root;
device->devid = devid;
device->work.func = pending_bios_fn;
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 31b0fab..2b638b6 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -42,7 +42,6 @@ struct btrfs_device {
int running_pending;
u64 generation;
- int barriers;
int writeable;
int in_fs_metadata;
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 29/41] btrfs: replace barriers with explicit flush / FUA usage
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
Switch to the WRITE_FLUSH_FUA flag for log writes, remove the EOPNOTSUPP
detection for barriers and stop setting the barrier flag for discards.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/btrfs/disk-io.c | 19 ++++---------------
fs/btrfs/extent-tree.c | 2 +-
fs/btrfs/volumes.c | 4 ----
fs/btrfs/volumes.h | 1 -
4 files changed, 5 insertions(+), 21 deletions(-)
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 64f1008..5e789f4 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2063,7 +2063,7 @@ static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
if (uptodate) {
set_buffer_uptodate(bh);
} else {
- if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
+ if (printk_ratelimit()) {
printk(KERN_WARNING "lost page write due to "
"I/O error on %s\n",
bdevname(bh->b_bdev, b));
@@ -2200,21 +2200,10 @@ static int write_dev_supers(struct btrfs_device *device,
bh->b_end_io = btrfs_end_buffer_write_sync;
}
- if (i == last_barrier && do_barriers && device->barriers) {
- ret = submit_bh(WRITE_BARRIER, bh);
- if (ret == -EOPNOTSUPP) {
- printk("btrfs: disabling barriers on dev %s\n",
- device->name);
- set_buffer_uptodate(bh);
- device->barriers = 0;
- /* one reference for submit_bh */
- get_bh(bh);
- lock_buffer(bh);
- ret = submit_bh(WRITE_SYNC, bh);
- }
- } else {
+ if (i == last_barrier && do_barriers)
+ ret = submit_bh(WRITE_FLUSH_FUA, bh);
+ else
ret = submit_bh(WRITE_SYNC, bh);
- }
if (ret)
errors++;
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 32d0940..43dc9ea 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1696,7 +1696,7 @@ static void btrfs_issue_discard(struct block_device *bdev,
u64 start, u64 len)
{
blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ BLKDEV_IFL_WAIT);
}
static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index dd318ff..e25e46a 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -398,7 +398,6 @@ static noinline int device_list_add(const char *path,
device->work.func = pending_bios_fn;
memcpy(device->uuid, disk_super->dev_item.uuid,
BTRFS_UUID_SIZE);
- device->barriers = 1;
spin_lock_init(&device->io_lock);
device->name = kstrdup(path, GFP_NOFS);
if (!device->name) {
@@ -462,7 +461,6 @@ static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
device->devid = orig_dev->devid;
device->work.func = pending_bios_fn;
memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
- device->barriers = 1;
spin_lock_init(&device->io_lock);
INIT_LIST_HEAD(&device->dev_list);
INIT_LIST_HEAD(&device->dev_alloc_list);
@@ -1489,7 +1487,6 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
trans = btrfs_start_transaction(root, 0);
lock_chunks(root);
- device->barriers = 1;
device->writeable = 1;
device->work.func = pending_bios_fn;
generate_random_uuid(device->uuid);
@@ -3084,7 +3081,6 @@ static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
return NULL;
list_add(&device->dev_list,
&fs_devices->devices);
- device->barriers = 1;
device->dev_root = root->fs_info->dev_root;
device->devid = devid;
device->work.func = pending_bios_fn;
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 31b0fab..2b638b6 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -42,7 +42,6 @@ struct btrfs_device {
int running_pending;
u64 generation;
- int barriers;
int writeable;
int in_fs_metadata;
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 29/41] btrfs: replace barriers with explicit flush / FUA usage
2010-09-03 10:29 ` Tejun Heo
` (40 preceding siblings ...)
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
Switch to the WRITE_FLUSH_FUA flag for log writes, remove the EOPNOTSUPP
detection for barriers and stop setting the barrier flag for discards.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/btrfs/disk-io.c | 19 ++++---------------
fs/btrfs/extent-tree.c | 2 +-
fs/btrfs/volumes.c | 4 ----
fs/btrfs/volumes.h | 1 -
4 files changed, 5 insertions(+), 21 deletions(-)
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 64f1008..5e789f4 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2063,7 +2063,7 @@ static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
if (uptodate) {
set_buffer_uptodate(bh);
} else {
- if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
+ if (printk_ratelimit()) {
printk(KERN_WARNING "lost page write due to "
"I/O error on %s\n",
bdevname(bh->b_bdev, b));
@@ -2200,21 +2200,10 @@ static int write_dev_supers(struct btrfs_device *device,
bh->b_end_io = btrfs_end_buffer_write_sync;
}
- if (i == last_barrier && do_barriers && device->barriers) {
- ret = submit_bh(WRITE_BARRIER, bh);
- if (ret == -EOPNOTSUPP) {
- printk("btrfs: disabling barriers on dev %s\n",
- device->name);
- set_buffer_uptodate(bh);
- device->barriers = 0;
- /* one reference for submit_bh */
- get_bh(bh);
- lock_buffer(bh);
- ret = submit_bh(WRITE_SYNC, bh);
- }
- } else {
+ if (i == last_barrier && do_barriers)
+ ret = submit_bh(WRITE_FLUSH_FUA, bh);
+ else
ret = submit_bh(WRITE_SYNC, bh);
- }
if (ret)
errors++;
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 32d0940..43dc9ea 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1696,7 +1696,7 @@ static void btrfs_issue_discard(struct block_device *bdev,
u64 start, u64 len)
{
blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ BLKDEV_IFL_WAIT);
}
static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index dd318ff..e25e46a 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -398,7 +398,6 @@ static noinline int device_list_add(const char *path,
device->work.func = pending_bios_fn;
memcpy(device->uuid, disk_super->dev_item.uuid,
BTRFS_UUID_SIZE);
- device->barriers = 1;
spin_lock_init(&device->io_lock);
device->name = kstrdup(path, GFP_NOFS);
if (!device->name) {
@@ -462,7 +461,6 @@ static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
device->devid = orig_dev->devid;
device->work.func = pending_bios_fn;
memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
- device->barriers = 1;
spin_lock_init(&device->io_lock);
INIT_LIST_HEAD(&device->dev_list);
INIT_LIST_HEAD(&device->dev_alloc_list);
@@ -1489,7 +1487,6 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
trans = btrfs_start_transaction(root, 0);
lock_chunks(root);
- device->barriers = 1;
device->writeable = 1;
device->work.func = pending_bios_fn;
generate_random_uuid(device->uuid);
@@ -3084,7 +3081,6 @@ static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
return NULL;
list_add(&device->dev_list,
&fs_devices->devices);
- device->barriers = 1;
device->dev_root = root->fs_info->dev_root;
device->devid = devid;
device->work.func = pending_bios_fn;
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 31b0fab..2b638b6 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -42,7 +42,6 @@ struct btrfs_device {
int running_pending;
u64 generation;
- int barriers;
int writeable;
int in_fs_metadata;
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 30/41] gfs2: replace barriers with explicit flush / FUA usage
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
Switch to the WRITE_FLUSH_FUA flag for log writes, remove the EOPNOTSUPP
detection for barriers and stop setting the barrier flag for discards.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/gfs2/log.c | 19 +++++--------------
fs/gfs2/rgrp.c | 5 ++---
2 files changed, 7 insertions(+), 17 deletions(-)
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index cde1248..9c65170 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -592,22 +592,13 @@ static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull)
lh->lh_hash = cpu_to_be32(hash);
bh->b_end_io = end_buffer_write_sync;
- if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
- goto skip_barrier;
get_bh(bh);
- submit_bh(WRITE_BARRIER | REQ_META, bh);
- wait_on_buffer(bh);
- if (buffer_eopnotsupp(bh)) {
- clear_buffer_eopnotsupp(bh);
- set_buffer_uptodate(bh);
- fs_info(sdp, "barrier sync failed - disabling barriers\n");
- set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
- lock_buffer(bh);
-skip_barrier:
- get_bh(bh);
+ if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
submit_bh(WRITE_SYNC | REQ_META, bh);
- wait_on_buffer(bh);
- }
+ else
+ submit_bh(WRITE_FLUSH_FUA | REQ_META, bh);
+ wait_on_buffer(bh);
+
if (!buffer_uptodate(bh))
gfs2_io_error_bh(sdp, bh);
brelse(bh);
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 171a744..3793164 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -854,8 +854,7 @@ static void gfs2_rgrp_send_discards(struct gfs2_sbd *sdp, u64 offset,
if ((start + nr_sects) != blk) {
rv = blkdev_issue_discard(bdev, start,
nr_sects, GFP_NOFS,
- BLKDEV_IFL_WAIT |
- BLKDEV_IFL_BARRIER);
+ BLKDEV_IFL_WAIT);
if (rv)
goto fail;
nr_sects = 0;
@@ -870,7 +869,7 @@ start_new_extent:
}
if (nr_sects) {
rv = blkdev_issue_discard(bdev, start, nr_sects, GFP_NOFS,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ BLKDEV_IFL_WAIT);
if (rv)
goto fail;
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 30/41] gfs2: replace barriers with explicit flush / FUA usage
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
Switch to the WRITE_FLUSH_FUA flag for log writes, remove the EOPNOTSUPP
detection for barriers and stop setting the barrier flag for discards.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/gfs2/log.c | 19 +++++--------------
fs/gfs2/rgrp.c | 5 ++---
2 files changed, 7 insertions(+), 17 deletions(-)
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index cde1248..9c65170 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -592,22 +592,13 @@ static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull)
lh->lh_hash = cpu_to_be32(hash);
bh->b_end_io = end_buffer_write_sync;
- if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
- goto skip_barrier;
get_bh(bh);
- submit_bh(WRITE_BARRIER | REQ_META, bh);
- wait_on_buffer(bh);
- if (buffer_eopnotsupp(bh)) {
- clear_buffer_eopnotsupp(bh);
- set_buffer_uptodate(bh);
- fs_info(sdp, "barrier sync failed - disabling barriers\n");
- set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
- lock_buffer(bh);
-skip_barrier:
- get_bh(bh);
+ if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
submit_bh(WRITE_SYNC | REQ_META, bh);
- wait_on_buffer(bh);
- }
+ else
+ submit_bh(WRITE_FLUSH_FUA | REQ_META, bh);
+ wait_on_buffer(bh);
+
if (!buffer_uptodate(bh))
gfs2_io_error_bh(sdp, bh);
brelse(bh);
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 171a744..3793164 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -854,8 +854,7 @@ static void gfs2_rgrp_send_discards(struct gfs2_sbd *sdp, u64 offset,
if ((start + nr_sects) != blk) {
rv = blkdev_issue_discard(bdev, start,
nr_sects, GFP_NOFS,
- BLKDEV_IFL_WAIT |
- BLKDEV_IFL_BARRIER);
+ BLKDEV_IFL_WAIT);
if (rv)
goto fail;
nr_sects = 0;
@@ -870,7 +869,7 @@ start_new_extent:
}
if (nr_sects) {
rv = blkdev_issue_discard(bdev, start, nr_sects, GFP_NOFS,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ BLKDEV_IFL_WAIT);
if (rv)
goto fail;
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 30/41] gfs2: replace barriers with explicit flush / FUA usage
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
Switch to the WRITE_FLUSH_FUA flag for log writes, remove the EOPNOTSUPP
detection for barriers and stop setting the barrier flag for discards.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/gfs2/log.c | 19 +++++--------------
fs/gfs2/rgrp.c | 5 ++---
2 files changed, 7 insertions(+), 17 deletions(-)
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index cde1248..9c65170 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -592,22 +592,13 @@ static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull)
lh->lh_hash = cpu_to_be32(hash);
bh->b_end_io = end_buffer_write_sync;
- if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
- goto skip_barrier;
get_bh(bh);
- submit_bh(WRITE_BARRIER | REQ_META, bh);
- wait_on_buffer(bh);
- if (buffer_eopnotsupp(bh)) {
- clear_buffer_eopnotsupp(bh);
- set_buffer_uptodate(bh);
- fs_info(sdp, "barrier sync failed - disabling barriers\n");
- set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
- lock_buffer(bh);
-skip_barrier:
- get_bh(bh);
+ if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
submit_bh(WRITE_SYNC | REQ_META, bh);
- wait_on_buffer(bh);
- }
+ else
+ submit_bh(WRITE_FLUSH_FUA | REQ_META, bh);
+ wait_on_buffer(bh);
+
if (!buffer_uptodate(bh))
gfs2_io_error_bh(sdp, bh);
brelse(bh);
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 171a744..3793164 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -854,8 +854,7 @@ static void gfs2_rgrp_send_discards(struct gfs2_sbd *sdp, u64 offset,
if ((start + nr_sects) != blk) {
rv = blkdev_issue_discard(bdev, start,
nr_sects, GFP_NOFS,
- BLKDEV_IFL_WAIT |
- BLKDEV_IFL_BARRIER);
+ BLKDEV_IFL_WAIT);
if (rv)
goto fail;
nr_sects = 0;
@@ -870,7 +869,7 @@ start_new_extent:
}
if (nr_sects) {
rv = blkdev_issue_discard(bdev, start, nr_sects, GFP_NOFS,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ BLKDEV_IFL_WAIT);
if (rv)
goto fail;
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 31/41] reiserfs: replace barriers with explicit flush / FUA usage
2010-09-03 10:29 ` Tejun Heo
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
Switch to the WRITE_FLUSH_FUA flag for log writes and remove the EOPNOTSUPP
detection for barriers. Note that reiserfs had a fairly different code
path for barriers before as it wa the only filesystem actually making use
of them. The new code always uses the old non-barrier codepath and just
sets the WRITE_FLUSH_FUA explicitly for the journal commits.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jan Kara <jack@suse.cz>
Acked-by: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/reiserfs/journal.c | 106 +++++++++---------------------------------------
1 files changed, 20 insertions(+), 86 deletions(-)
diff --git a/fs/reiserfs/journal.c b/fs/reiserfs/journal.c
index 812e2c0..076c8b1 100644
--- a/fs/reiserfs/journal.c
+++ b/fs/reiserfs/journal.c
@@ -138,13 +138,6 @@ static int reiserfs_clean_and_file_buffer(struct buffer_head *bh)
return 0;
}
-static void disable_barrier(struct super_block *s)
-{
- REISERFS_SB(s)->s_mount_opt &= ~(1 << REISERFS_BARRIER_FLUSH);
- printk("reiserfs: disabling flush barriers on %s\n",
- reiserfs_bdevname(s));
-}
-
static struct reiserfs_bitmap_node *allocate_bitmap_node(struct super_block
*sb)
{
@@ -677,30 +670,6 @@ static void submit_ordered_buffer(struct buffer_head *bh)
submit_bh(WRITE, bh);
}
-static int submit_barrier_buffer(struct buffer_head *bh)
-{
- get_bh(bh);
- bh->b_end_io = reiserfs_end_ordered_io;
- clear_buffer_dirty(bh);
- if (!buffer_uptodate(bh))
- BUG();
- return submit_bh(WRITE_BARRIER, bh);
-}
-
-static void check_barrier_completion(struct super_block *s,
- struct buffer_head *bh)
-{
- if (buffer_eopnotsupp(bh)) {
- clear_buffer_eopnotsupp(bh);
- disable_barrier(s);
- set_buffer_uptodate(bh);
- set_buffer_dirty(bh);
- reiserfs_write_unlock(s);
- sync_dirty_buffer(bh);
- reiserfs_write_lock(s);
- }
-}
-
#define CHUNK_SIZE 32
struct buffer_chunk {
struct buffer_head *bh[CHUNK_SIZE];
@@ -1009,7 +978,6 @@ static int flush_commit_list(struct super_block *s,
struct buffer_head *tbh = NULL;
unsigned int trans_id = jl->j_trans_id;
struct reiserfs_journal *journal = SB_JOURNAL(s);
- int barrier = 0;
int retval = 0;
int write_len;
@@ -1094,24 +1062,6 @@ static int flush_commit_list(struct super_block *s,
}
atomic_dec(&journal->j_async_throttle);
- /* We're skipping the commit if there's an error */
- if (retval || reiserfs_is_journal_aborted(journal))
- barrier = 0;
-
- /* wait on everything written so far before writing the commit
- * if we are in barrier mode, send the commit down now
- */
- barrier = reiserfs_barrier_flush(s);
- if (barrier) {
- int ret;
- lock_buffer(jl->j_commit_bh);
- ret = submit_barrier_buffer(jl->j_commit_bh);
- if (ret == -EOPNOTSUPP) {
- set_buffer_uptodate(jl->j_commit_bh);
- disable_barrier(s);
- barrier = 0;
- }
- }
for (i = 0; i < (jl->j_len + 1); i++) {
bn = SB_ONDISK_JOURNAL_1st_BLOCK(s) +
(jl->j_start + i) % SB_ONDISK_JOURNAL_SIZE(s);
@@ -1143,27 +1093,22 @@ static int flush_commit_list(struct super_block *s,
BUG_ON(atomic_read(&(jl->j_commit_left)) != 1);
- if (!barrier) {
- /* If there was a write error in the journal - we can't commit
- * this transaction - it will be invalid and, if successful,
- * will just end up propagating the write error out to
- * the file system. */
- if (likely(!retval && !reiserfs_is_journal_aborted (journal))) {
- if (buffer_dirty(jl->j_commit_bh))
- BUG();
- mark_buffer_dirty(jl->j_commit_bh) ;
- reiserfs_write_unlock(s);
- sync_dirty_buffer(jl->j_commit_bh) ;
- reiserfs_write_lock(s);
- }
- } else {
+ /* If there was a write error in the journal - we can't commit
+ * this transaction - it will be invalid and, if successful,
+ * will just end up propagating the write error out to
+ * the file system. */
+ if (likely(!retval && !reiserfs_is_journal_aborted (journal))) {
+ if (buffer_dirty(jl->j_commit_bh))
+ BUG();
+ mark_buffer_dirty(jl->j_commit_bh) ;
reiserfs_write_unlock(s);
- wait_on_buffer(jl->j_commit_bh);
+ if (reiserfs_barrier_flush(s))
+ __sync_dirty_buffer(jl->j_commit_bh, WRITE_FLUSH_FUA);
+ else
+ sync_dirty_buffer(jl->j_commit_bh);
reiserfs_write_lock(s);
}
- check_barrier_completion(s, jl->j_commit_bh);
-
/* If there was a write error in the journal - we can't commit this
* transaction - it will be invalid and, if successful, will just end
* up propagating the write error out to the filesystem. */
@@ -1319,26 +1264,15 @@ static int _update_journal_header_block(struct super_block *sb,
jh->j_first_unflushed_offset = cpu_to_le32(offset);
jh->j_mount_id = cpu_to_le32(journal->j_mount_id);
- if (reiserfs_barrier_flush(sb)) {
- int ret;
- lock_buffer(journal->j_header_bh);
- ret = submit_barrier_buffer(journal->j_header_bh);
- if (ret == -EOPNOTSUPP) {
- set_buffer_uptodate(journal->j_header_bh);
- disable_barrier(sb);
- goto sync;
- }
- reiserfs_write_unlock(sb);
- wait_on_buffer(journal->j_header_bh);
- reiserfs_write_lock(sb);
- check_barrier_completion(sb, journal->j_header_bh);
- } else {
- sync:
- set_buffer_dirty(journal->j_header_bh);
- reiserfs_write_unlock(sb);
+ set_buffer_dirty(journal->j_header_bh);
+ reiserfs_write_unlock(sb);
+
+ if (reiserfs_barrier_flush(sb))
+ __sync_dirty_buffer(journal->j_header_bh, WRITE_FLUSH_FUA);
+ else
sync_dirty_buffer(journal->j_header_bh);
- reiserfs_write_lock(sb);
- }
+
+ reiserfs_write_lock(sb);
if (!buffer_uptodate(journal->j_header_bh)) {
reiserfs_warning(sb, "journal-837",
"IO error during journal replay");
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 31/41] reiserfs: replace barriers with explicit flush / FUA usage
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
Switch to the WRITE_FLUSH_FUA flag for log writes and remove the EOPNOTSUPP
detection for barriers. Note that reiserfs had a fairly different code
path for barriers before as it wa the only filesystem actually making use
of them. The new code always uses the old non-barrier codepath and just
sets the WRITE_FLUSH_FUA explicitly for the journal commits.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jan Kara <jack@suse.cz>
Acked-by: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/reiserfs/journal.c | 106 +++++++++---------------------------------------
1 files changed, 20 insertions(+), 86 deletions(-)
diff --git a/fs/reiserfs/journal.c b/fs/reiserfs/journal.c
index 812e2c0..076c8b1 100644
--- a/fs/reiserfs/journal.c
+++ b/fs/reiserfs/journal.c
@@ -138,13 +138,6 @@ static int reiserfs_clean_and_file_buffer(struct buffer_head *bh)
return 0;
}
-static void disable_barrier(struct super_block *s)
-{
- REISERFS_SB(s)->s_mount_opt &= ~(1 << REISERFS_BARRIER_FLUSH);
- printk("reiserfs: disabling flush barriers on %s\n",
- reiserfs_bdevname(s));
-}
-
static struct reiserfs_bitmap_node *allocate_bitmap_node(struct super_block
*sb)
{
@@ -677,30 +670,6 @@ static void submit_ordered_buffer(struct buffer_head *bh)
submit_bh(WRITE, bh);
}
-static int submit_barrier_buffer(struct buffer_head *bh)
-{
- get_bh(bh);
- bh->b_end_io = reiserfs_end_ordered_io;
- clear_buffer_dirty(bh);
- if (!buffer_uptodate(bh))
- BUG();
- return submit_bh(WRITE_BARRIER, bh);
-}
-
-static void check_barrier_completion(struct super_block *s,
- struct buffer_head *bh)
-{
- if (buffer_eopnotsupp(bh)) {
- clear_buffer_eopnotsupp(bh);
- disable_barrier(s);
- set_buffer_uptodate(bh);
- set_buffer_dirty(bh);
- reiserfs_write_unlock(s);
- sync_dirty_buffer(bh);
- reiserfs_write_lock(s);
- }
-}
-
#define CHUNK_SIZE 32
struct buffer_chunk {
struct buffer_head *bh[CHUNK_SIZE];
@@ -1009,7 +978,6 @@ static int flush_commit_list(struct super_block *s,
struct buffer_head *tbh = NULL;
unsigned int trans_id = jl->j_trans_id;
struct reiserfs_journal *journal = SB_JOURNAL(s);
- int barrier = 0;
int retval = 0;
int write_len;
@@ -1094,24 +1062,6 @@ static int flush_commit_list(struct super_block *s,
}
atomic_dec(&journal->j_async_throttle);
- /* We're skipping the commit if there's an error */
- if (retval || reiserfs_is_journal_aborted(journal))
- barrier = 0;
-
- /* wait on everything written so far before writing the commit
- * if we are in barrier mode, send the commit down now
- */
- barrier = reiserfs_barrier_flush(s);
- if (barrier) {
- int ret;
- lock_buffer(jl->j_commit_bh);
- ret = submit_barrier_buffer(jl->j_commit_bh);
- if (ret == -EOPNOTSUPP) {
- set_buffer_uptodate(jl->j_commit_bh);
- disable_barrier(s);
- barrier = 0;
- }
- }
for (i = 0; i < (jl->j_len + 1); i++) {
bn = SB_ONDISK_JOURNAL_1st_BLOCK(s) +
(jl->j_start + i) % SB_ONDISK_JOURNAL_SIZE(s);
@@ -1143,27 +1093,22 @@ static int flush_commit_list(struct super_block *s,
BUG_ON(atomic_read(&(jl->j_commit_left)) != 1);
- if (!barrier) {
- /* If there was a write error in the journal - we can't commit
- * this transaction - it will be invalid and, if successful,
- * will just end up propagating the write error out to
- * the file system. */
- if (likely(!retval && !reiserfs_is_journal_aborted (journal))) {
- if (buffer_dirty(jl->j_commit_bh))
- BUG();
- mark_buffer_dirty(jl->j_commit_bh) ;
- reiserfs_write_unlock(s);
- sync_dirty_buffer(jl->j_commit_bh) ;
- reiserfs_write_lock(s);
- }
- } else {
+ /* If there was a write error in the journal - we can't commit
+ * this transaction - it will be invalid and, if successful,
+ * will just end up propagating the write error out to
+ * the file system. */
+ if (likely(!retval && !reiserfs_is_journal_aborted (journal))) {
+ if (buffer_dirty(jl->j_commit_bh))
+ BUG();
+ mark_buffer_dirty(jl->j_commit_bh) ;
reiserfs_write_unlock(s);
- wait_on_buffer(jl->j_commit_bh);
+ if (reiserfs_barrier_flush(s))
+ __sync_dirty_buffer(jl->j_commit_bh, WRITE_FLUSH_FUA);
+ else
+ sync_dirty_buffer(jl->j_commit_bh);
reiserfs_write_lock(s);
}
- check_barrier_completion(s, jl->j_commit_bh);
-
/* If there was a write error in the journal - we can't commit this
* transaction - it will be invalid and, if successful, will just end
* up propagating the write error out to the filesystem. */
@@ -1319,26 +1264,15 @@ static int _update_journal_header_block(struct super_block *sb,
jh->j_first_unflushed_offset = cpu_to_le32(offset);
jh->j_mount_id = cpu_to_le32(journal->j_mount_id);
- if (reiserfs_barrier_flush(sb)) {
- int ret;
- lock_buffer(journal->j_header_bh);
- ret = submit_barrier_buffer(journal->j_header_bh);
- if (ret == -EOPNOTSUPP) {
- set_buffer_uptodate(journal->j_header_bh);
- disable_barrier(sb);
- goto sync;
- }
- reiserfs_write_unlock(sb);
- wait_on_buffer(journal->j_header_bh);
- reiserfs_write_lock(sb);
- check_barrier_completion(sb, journal->j_header_bh);
- } else {
- sync:
- set_buffer_dirty(journal->j_header_bh);
- reiserfs_write_unlock(sb);
+ set_buffer_dirty(journal->j_header_bh);
+ reiserfs_write_unlock(sb);
+
+ if (reiserfs_barrier_flush(sb))
+ __sync_dirty_buffer(journal->j_header_bh, WRITE_FLUSH_FUA);
+ else
sync_dirty_buffer(journal->j_header_bh);
- reiserfs_write_lock(sb);
- }
+
+ reiserfs_write_lock(sb);
if (!buffer_uptodate(journal->j_header_bh)) {
reiserfs_warning(sb, "journal-837",
"IO error during journal replay");
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 31/41] reiserfs: replace barriers with explicit flush / FUA usage
2010-09-03 10:29 ` Tejun Heo
` (43 preceding siblings ...)
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
Switch to the WRITE_FLUSH_FUA flag for log writes and remove the EOPNOTSUPP
detection for barriers. Note that reiserfs had a fairly different code
path for barriers before as it wa the only filesystem actually making use
of them. The new code always uses the old non-barrier codepath and just
sets the WRITE_FLUSH_FUA explicitly for the journal commits.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jan Kara <jack@suse.cz>
Acked-by: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/reiserfs/journal.c | 106 +++++++++---------------------------------------
1 files changed, 20 insertions(+), 86 deletions(-)
diff --git a/fs/reiserfs/journal.c b/fs/reiserfs/journal.c
index 812e2c0..076c8b1 100644
--- a/fs/reiserfs/journal.c
+++ b/fs/reiserfs/journal.c
@@ -138,13 +138,6 @@ static int reiserfs_clean_and_file_buffer(struct buffer_head *bh)
return 0;
}
-static void disable_barrier(struct super_block *s)
-{
- REISERFS_SB(s)->s_mount_opt &= ~(1 << REISERFS_BARRIER_FLUSH);
- printk("reiserfs: disabling flush barriers on %s\n",
- reiserfs_bdevname(s));
-}
-
static struct reiserfs_bitmap_node *allocate_bitmap_node(struct super_block
*sb)
{
@@ -677,30 +670,6 @@ static void submit_ordered_buffer(struct buffer_head *bh)
submit_bh(WRITE, bh);
}
-static int submit_barrier_buffer(struct buffer_head *bh)
-{
- get_bh(bh);
- bh->b_end_io = reiserfs_end_ordered_io;
- clear_buffer_dirty(bh);
- if (!buffer_uptodate(bh))
- BUG();
- return submit_bh(WRITE_BARRIER, bh);
-}
-
-static void check_barrier_completion(struct super_block *s,
- struct buffer_head *bh)
-{
- if (buffer_eopnotsupp(bh)) {
- clear_buffer_eopnotsupp(bh);
- disable_barrier(s);
- set_buffer_uptodate(bh);
- set_buffer_dirty(bh);
- reiserfs_write_unlock(s);
- sync_dirty_buffer(bh);
- reiserfs_write_lock(s);
- }
-}
-
#define CHUNK_SIZE 32
struct buffer_chunk {
struct buffer_head *bh[CHUNK_SIZE];
@@ -1009,7 +978,6 @@ static int flush_commit_list(struct super_block *s,
struct buffer_head *tbh = NULL;
unsigned int trans_id = jl->j_trans_id;
struct reiserfs_journal *journal = SB_JOURNAL(s);
- int barrier = 0;
int retval = 0;
int write_len;
@@ -1094,24 +1062,6 @@ static int flush_commit_list(struct super_block *s,
}
atomic_dec(&journal->j_async_throttle);
- /* We're skipping the commit if there's an error */
- if (retval || reiserfs_is_journal_aborted(journal))
- barrier = 0;
-
- /* wait on everything written so far before writing the commit
- * if we are in barrier mode, send the commit down now
- */
- barrier = reiserfs_barrier_flush(s);
- if (barrier) {
- int ret;
- lock_buffer(jl->j_commit_bh);
- ret = submit_barrier_buffer(jl->j_commit_bh);
- if (ret == -EOPNOTSUPP) {
- set_buffer_uptodate(jl->j_commit_bh);
- disable_barrier(s);
- barrier = 0;
- }
- }
for (i = 0; i < (jl->j_len + 1); i++) {
bn = SB_ONDISK_JOURNAL_1st_BLOCK(s) +
(jl->j_start + i) % SB_ONDISK_JOURNAL_SIZE(s);
@@ -1143,27 +1093,22 @@ static int flush_commit_list(struct super_block *s,
BUG_ON(atomic_read(&(jl->j_commit_left)) != 1);
- if (!barrier) {
- /* If there was a write error in the journal - we can't commit
- * this transaction - it will be invalid and, if successful,
- * will just end up propagating the write error out to
- * the file system. */
- if (likely(!retval && !reiserfs_is_journal_aborted (journal))) {
- if (buffer_dirty(jl->j_commit_bh))
- BUG();
- mark_buffer_dirty(jl->j_commit_bh) ;
- reiserfs_write_unlock(s);
- sync_dirty_buffer(jl->j_commit_bh) ;
- reiserfs_write_lock(s);
- }
- } else {
+ /* If there was a write error in the journal - we can't commit
+ * this transaction - it will be invalid and, if successful,
+ * will just end up propagating the write error out to
+ * the file system. */
+ if (likely(!retval && !reiserfs_is_journal_aborted (journal))) {
+ if (buffer_dirty(jl->j_commit_bh))
+ BUG();
+ mark_buffer_dirty(jl->j_commit_bh) ;
reiserfs_write_unlock(s);
- wait_on_buffer(jl->j_commit_bh);
+ if (reiserfs_barrier_flush(s))
+ __sync_dirty_buffer(jl->j_commit_bh, WRITE_FLUSH_FUA);
+ else
+ sync_dirty_buffer(jl->j_commit_bh);
reiserfs_write_lock(s);
}
- check_barrier_completion(s, jl->j_commit_bh);
-
/* If there was a write error in the journal - we can't commit this
* transaction - it will be invalid and, if successful, will just end
* up propagating the write error out to the filesystem. */
@@ -1319,26 +1264,15 @@ static int _update_journal_header_block(struct super_block *sb,
jh->j_first_unflushed_offset = cpu_to_le32(offset);
jh->j_mount_id = cpu_to_le32(journal->j_mount_id);
- if (reiserfs_barrier_flush(sb)) {
- int ret;
- lock_buffer(journal->j_header_bh);
- ret = submit_barrier_buffer(journal->j_header_bh);
- if (ret == -EOPNOTSUPP) {
- set_buffer_uptodate(journal->j_header_bh);
- disable_barrier(sb);
- goto sync;
- }
- reiserfs_write_unlock(sb);
- wait_on_buffer(journal->j_header_bh);
- reiserfs_write_lock(sb);
- check_barrier_completion(sb, journal->j_header_bh);
- } else {
- sync:
- set_buffer_dirty(journal->j_header_bh);
- reiserfs_write_unlock(sb);
+ set_buffer_dirty(journal->j_header_bh);
+ reiserfs_write_unlock(sb);
+
+ if (reiserfs_barrier_flush(sb))
+ __sync_dirty_buffer(journal->j_header_bh, WRITE_FLUSH_FUA);
+ else
sync_dirty_buffer(journal->j_header_bh);
- reiserfs_write_lock(sb);
- }
+
+ reiserfs_write_lock(sb);
if (!buffer_uptodate(journal->j_header_bh)) {
reiserfs_warning(sb, "journal-837",
"IO error during journal replay");
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 32/41] nilfs2: replace barriers with explicit flush / FUA usage
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
Switch to the WRITE_FLUSH_FUA flag for log writes, remove the EOPNOTSUPP
detection for barriers and stop setting the barrier flag for discards.
tj: nilfs is now fixed to wait for discard completion. Updated this
patch accordingly and dropped warning about it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/nilfs2/super.c | 10 +---------
fs/nilfs2/the_nilfs.c | 7 ++-----
2 files changed, 3 insertions(+), 14 deletions(-)
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 9222633..faa5078 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -178,17 +178,9 @@ static int nilfs_sync_super(struct nilfs_sb_info *sbi, int flag)
retry:
set_buffer_dirty(nilfs->ns_sbh[0]);
-
if (nilfs_test_opt(sbi, BARRIER)) {
err = __sync_dirty_buffer(nilfs->ns_sbh[0],
- WRITE_SYNC | WRITE_BARRIER);
- if (err == -EOPNOTSUPP) {
- nilfs_warning(sbi->s_super, __func__,
- "barrier-based sync failed. "
- "disabling barriers\n");
- nilfs_clear_opt(sbi, BARRIER);
- goto retry;
- }
+ WRITE_SYNC | WRITE_FLUSH_FUA);
} else {
err = sync_dirty_buffer(nilfs->ns_sbh[0]);
}
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index 4317f17..400b2ca 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -774,9 +774,7 @@ int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump,
ret = blkdev_issue_discard(nilfs->ns_bdev,
start * sects_per_block,
nblocks * sects_per_block,
- GFP_NOFS,
- BLKDEV_IFL_WAIT |
- BLKDEV_IFL_BARRIER);
+ GFP_NOFS, BLKDEV_IFL_WAIT);
if (ret < 0)
return ret;
nblocks = 0;
@@ -786,8 +784,7 @@ int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump,
ret = blkdev_issue_discard(nilfs->ns_bdev,
start * sects_per_block,
nblocks * sects_per_block,
- GFP_NOFS,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ GFP_NOFS, BLKDEV_IFL_WAIT);
return ret;
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 32/41] nilfs2: replace barriers with explicit flush / FUA usage
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
Switch to the WRITE_FLUSH_FUA flag for log writes, remove the EOPNOTSUPP
detection for barriers and stop setting the barrier flag for discards.
tj: nilfs is now fixed to wait for discard completion. Updated this
patch accordingly and dropped warning about it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/nilfs2/super.c | 10 +---------
fs/nilfs2/the_nilfs.c | 7 ++-----
2 files changed, 3 insertions(+), 14 deletions(-)
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 9222633..faa5078 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -178,17 +178,9 @@ static int nilfs_sync_super(struct nilfs_sb_info *sbi, int flag)
retry:
set_buffer_dirty(nilfs->ns_sbh[0]);
-
if (nilfs_test_opt(sbi, BARRIER)) {
err = __sync_dirty_buffer(nilfs->ns_sbh[0],
- WRITE_SYNC | WRITE_BARRIER);
- if (err == -EOPNOTSUPP) {
- nilfs_warning(sbi->s_super, __func__,
- "barrier-based sync failed. "
- "disabling barriers\n");
- nilfs_clear_opt(sbi, BARRIER);
- goto retry;
- }
+ WRITE_SYNC | WRITE_FLUSH_FUA);
} else {
err = sync_dirty_buffer(nilfs->ns_sbh[0]);
}
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index 4317f17..400b2ca 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -774,9 +774,7 @@ int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump,
ret = blkdev_issue_discard(nilfs->ns_bdev,
start * sects_per_block,
nblocks * sects_per_block,
- GFP_NOFS,
- BLKDEV_IFL_WAIT |
- BLKDEV_IFL_BARRIER);
+ GFP_NOFS, BLKDEV_IFL_WAIT);
if (ret < 0)
return ret;
nblocks = 0;
@@ -786,8 +784,7 @@ int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump,
ret = blkdev_issue_discard(nilfs->ns_bdev,
start * sects_per_block,
nblocks * sects_per_block,
- GFP_NOFS,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ GFP_NOFS, BLKDEV_IFL_WAIT);
return ret;
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 32/41] nilfs2: replace barriers with explicit flush / FUA usage
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
Switch to the WRITE_FLUSH_FUA flag for log writes, remove the EOPNOTSUPP
detection for barriers and stop setting the barrier flag for discards.
tj: nilfs is now fixed to wait for discard completion. Updated this
patch accordingly and dropped warning about it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/nilfs2/super.c | 10 +---------
fs/nilfs2/the_nilfs.c | 7 ++-----
2 files changed, 3 insertions(+), 14 deletions(-)
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 9222633..faa5078 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -178,17 +178,9 @@ static int nilfs_sync_super(struct nilfs_sb_info *sbi, int flag)
retry:
set_buffer_dirty(nilfs->ns_sbh[0]);
-
if (nilfs_test_opt(sbi, BARRIER)) {
err = __sync_dirty_buffer(nilfs->ns_sbh[0],
- WRITE_SYNC | WRITE_BARRIER);
- if (err == -EOPNOTSUPP) {
- nilfs_warning(sbi->s_super, __func__,
- "barrier-based sync failed. "
- "disabling barriers\n");
- nilfs_clear_opt(sbi, BARRIER);
- goto retry;
- }
+ WRITE_SYNC | WRITE_FLUSH_FUA);
} else {
err = sync_dirty_buffer(nilfs->ns_sbh[0]);
}
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index 4317f17..400b2ca 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -774,9 +774,7 @@ int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump,
ret = blkdev_issue_discard(nilfs->ns_bdev,
start * sects_per_block,
nblocks * sects_per_block,
- GFP_NOFS,
- BLKDEV_IFL_WAIT |
- BLKDEV_IFL_BARRIER);
+ GFP_NOFS, BLKDEV_IFL_WAIT);
if (ret < 0)
return ret;
nblocks = 0;
@@ -786,8 +784,7 @@ int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump,
ret = blkdev_issue_discard(nilfs->ns_bdev,
start * sects_per_block,
nblocks * sects_per_block,
- GFP_NOFS,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ GFP_NOFS, BLKDEV_IFL_WAIT);
return ret;
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 33/41] jbd: replace barriers with explicit flush / FUA usage
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
Switch to the WRITE_FLUSH_FUA flag for journal commits and remove the
EOPNOTSUPP detection for barriers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/jbd/commit.c | 30 +++---------------------------
1 files changed, 3 insertions(+), 27 deletions(-)
diff --git a/fs/jbd/commit.c b/fs/jbd/commit.c
index 95d8c11..484c5e5 100644
--- a/fs/jbd/commit.c
+++ b/fs/jbd/commit.c
@@ -137,34 +137,10 @@ static int journal_write_commit_record(journal_t *journal,
JBUFFER_TRACE(descriptor, "write commit block");
set_buffer_dirty(bh);
- if (journal->j_flags & JFS_BARRIER) {
- ret = __sync_dirty_buffer(bh, WRITE_SYNC | WRITE_BARRIER);
-
- /*
- * Is it possible for another commit to fail at roughly
- * the same time as this one? If so, we don't want to
- * trust the barrier flag in the super, but instead want
- * to remember if we sent a barrier request
- */
- if (ret == -EOPNOTSUPP) {
- char b[BDEVNAME_SIZE];
-
- printk(KERN_WARNING
- "JBD: barrier-based sync failed on %s - "
- "disabling barriers\n",
- bdevname(journal->j_dev, b));
- spin_lock(&journal->j_state_lock);
- journal->j_flags &= ~JFS_BARRIER;
- spin_unlock(&journal->j_state_lock);
-
- /* And try again, without the barrier */
- set_buffer_uptodate(bh);
- set_buffer_dirty(bh);
- ret = sync_dirty_buffer(bh);
- }
- } else {
+ if (journal->j_flags & JFS_BARRIER)
+ ret = __sync_dirty_buffer(bh, WRITE_SYNC | WRITE_FLUSH_FUA);
+ else
ret = sync_dirty_buffer(bh);
- }
put_bh(bh); /* One for getblk() */
journal_put_journal_head(descriptor);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 33/41] jbd: replace barriers with explicit flush / FUA usage
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
Switch to the WRITE_FLUSH_FUA flag for journal commits and remove the
EOPNOTSUPP detection for barriers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/jbd/commit.c | 30 +++---------------------------
1 files changed, 3 insertions(+), 27 deletions(-)
diff --git a/fs/jbd/commit.c b/fs/jbd/commit.c
index 95d8c11..484c5e5 100644
--- a/fs/jbd/commit.c
+++ b/fs/jbd/commit.c
@@ -137,34 +137,10 @@ static int journal_write_commit_record(journal_t *journal,
JBUFFER_TRACE(descriptor, "write commit block");
set_buffer_dirty(bh);
- if (journal->j_flags & JFS_BARRIER) {
- ret = __sync_dirty_buffer(bh, WRITE_SYNC | WRITE_BARRIER);
-
- /*
- * Is it possible for another commit to fail at roughly
- * the same time as this one? If so, we don't want to
- * trust the barrier flag in the super, but instead want
- * to remember if we sent a barrier request
- */
- if (ret == -EOPNOTSUPP) {
- char b[BDEVNAME_SIZE];
-
- printk(KERN_WARNING
- "JBD: barrier-based sync failed on %s - "
- "disabling barriers\n",
- bdevname(journal->j_dev, b));
- spin_lock(&journal->j_state_lock);
- journal->j_flags &= ~JFS_BARRIER;
- spin_unlock(&journal->j_state_lock);
-
- /* And try again, without the barrier */
- set_buffer_uptodate(bh);
- set_buffer_dirty(bh);
- ret = sync_dirty_buffer(bh);
- }
- } else {
+ if (journal->j_flags & JFS_BARRIER)
+ ret = __sync_dirty_buffer(bh, WRITE_SYNC | WRITE_FLUSH_FUA);
+ else
ret = sync_dirty_buffer(bh);
- }
put_bh(bh); /* One for getblk() */
journal_put_journal_head(descriptor);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 33/41] jbd: replace barriers with explicit flush / FUA usage
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
Switch to the WRITE_FLUSH_FUA flag for journal commits and remove the
EOPNOTSUPP detection for barriers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/jbd/commit.c | 30 +++---------------------------
1 files changed, 3 insertions(+), 27 deletions(-)
diff --git a/fs/jbd/commit.c b/fs/jbd/commit.c
index 95d8c11..484c5e5 100644
--- a/fs/jbd/commit.c
+++ b/fs/jbd/commit.c
@@ -137,34 +137,10 @@ static int journal_write_commit_record(journal_t *journal,
JBUFFER_TRACE(descriptor, "write commit block");
set_buffer_dirty(bh);
- if (journal->j_flags & JFS_BARRIER) {
- ret = __sync_dirty_buffer(bh, WRITE_SYNC | WRITE_BARRIER);
-
- /*
- * Is it possible for another commit to fail at roughly
- * the same time as this one? If so, we don't want to
- * trust the barrier flag in the super, but instead want
- * to remember if we sent a barrier request
- */
- if (ret == -EOPNOTSUPP) {
- char b[BDEVNAME_SIZE];
-
- printk(KERN_WARNING
- "JBD: barrier-based sync failed on %s - "
- "disabling barriers\n",
- bdevname(journal->j_dev, b));
- spin_lock(&journal->j_state_lock);
- journal->j_flags &= ~JFS_BARRIER;
- spin_unlock(&journal->j_state_lock);
-
- /* And try again, without the barrier */
- set_buffer_uptodate(bh);
- set_buffer_dirty(bh);
- ret = sync_dirty_buffer(bh);
- }
- } else {
+ if (journal->j_flags & JFS_BARRIER)
+ ret = __sync_dirty_buffer(bh, WRITE_SYNC | WRITE_FLUSH_FUA);
+ else
ret = sync_dirty_buffer(bh);
- }
put_bh(bh); /* One for getblk() */
journal_put_journal_head(descriptor);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 34/41] jbd2: Modify ASYNC_COMMIT code to not rely on queue draining on barrier
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
From: Jan Kara <jack@suse.cz>
Currently JBD2 relies blkdev_issue_flush() draining the queue when ASYNC_COMMIT
feature is set. This property is going away so make JBD2 wait for buffers it
needs on its own before submitting the cache flush.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/jbd2/commit.c | 29 ++++++++++++++++-------------
1 files changed, 16 insertions(+), 13 deletions(-)
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 7c068c1..d6aeb1f 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -701,6 +701,16 @@ start_journal_io:
}
}
+ err = journal_finish_inode_data_buffers(journal, commit_transaction);
+ if (err) {
+ printk(KERN_WARNING
+ "JBD2: Detected IO errors while flushing file data "
+ "on %s\n", journal->j_devname);
+ if (journal->j_flags & JBD2_ABORT_ON_SYNCDATA_ERR)
+ jbd2_journal_abort(journal, err);
+ err = 0;
+ }
+
/*
* If the journal is not located on the file system device,
* then we must flush the file system device before we issue
@@ -719,19 +729,6 @@ start_journal_io:
&cbh, crc32_sum);
if (err)
__jbd2_journal_abort_hard(journal);
- if (journal->j_flags & JBD2_BARRIER)
- blkdev_issue_flush(journal->j_dev, GFP_KERNEL, NULL,
- BLKDEV_IFL_WAIT);
- }
-
- err = journal_finish_inode_data_buffers(journal, commit_transaction);
- if (err) {
- printk(KERN_WARNING
- "JBD2: Detected IO errors while flushing file data "
- "on %s\n", journal->j_devname);
- if (journal->j_flags & JBD2_ABORT_ON_SYNCDATA_ERR)
- jbd2_journal_abort(journal, err);
- err = 0;
}
/* Lo and behold: we have just managed to send a transaction to
@@ -845,6 +842,12 @@ wait_for_iobuf:
}
if (!err && !is_journal_aborted(journal))
err = journal_wait_on_commit_record(journal, cbh);
+ if (JBD2_HAS_INCOMPAT_FEATURE(journal,
+ JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT) &&
+ journal->j_flags & JBD2_BARRIER) {
+ blkdev_issue_flush(journal->j_dev, GFP_KERNEL, NULL,
+ BLKDEV_IFL_WAIT);
+ }
if (err)
jbd2_journal_abort(journal, err);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 34/41] jbd2: Modify ASYNC_COMMIT code to not rely on queue draining on barrier
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Tejun Heo
From: Jan Kara <jack@suse.cz>
Currently JBD2 relies blkdev_issue_flush() draining the queue when ASYNC_COMMIT
feature is set. This property is going away so make JBD2 wait for buffers it
needs on its own before submitting the cache flush.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/jbd2/commit.c | 29 ++++++++++++++++-------------
1 files changed, 16 insertions(+), 13 deletions(-)
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 7c068c1..d6aeb1f 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -701,6 +701,16 @@ start_journal_io:
}
}
+ err = journal_finish_inode_data_buffers(journal, commit_transaction);
+ if (err) {
+ printk(KERN_WARNING
+ "JBD2: Detected IO errors while flushing file data "
+ "on %s\n", journal->j_devname);
+ if (journal->j_flags & JBD2_ABORT_ON_SYNCDATA_ERR)
+ jbd2_journal_abort(journal, err);
+ err = 0;
+ }
+
/*
* If the journal is not located on the file system device,
* then we must flush the file system device before we issue
@@ -719,19 +729,6 @@ start_journal_io:
&cbh, crc32_sum);
if (err)
__jbd2_journal_abort_hard(journal);
- if (journal->j_flags & JBD2_BARRIER)
- blkdev_issue_flush(journal->j_dev, GFP_KERNEL, NULL,
- BLKDEV_IFL_WAIT);
- }
-
- err = journal_finish_inode_data_buffers(journal, commit_transaction);
- if (err) {
- printk(KERN_WARNING
- "JBD2: Detected IO errors while flushing file data "
- "on %s\n", journal->j_devname);
- if (journal->j_flags & JBD2_ABORT_ON_SYNCDATA_ERR)
- jbd2_journal_abort(journal, err);
- err = 0;
}
/* Lo and behold: we have just managed to send a transaction to
@@ -845,6 +842,12 @@ wait_for_iobuf:
}
if (!err && !is_journal_aborted(journal))
err = journal_wait_on_commit_record(journal, cbh);
+ if (JBD2_HAS_INCOMPAT_FEATURE(journal,
+ JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT) &&
+ journal->j_flags & JBD2_BARRIER) {
+ blkdev_issue_flush(journal->j_dev, GFP_KERNEL, NULL,
+ BLKDEV_IFL_WAIT);
+ }
if (err)
jbd2_journal_abort(journal, err);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 34/41] jbd2: Modify ASYNC_COMMIT code to not rely on queue draining on barrier
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Tejun Heo
From: Jan Kara <jack@suse.cz>
Currently JBD2 relies blkdev_issue_flush() draining the queue when ASYNC_COMMIT
feature is set. This property is going away so make JBD2 wait for buffers it
needs on its own before submitting the cache flush.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/jbd2/commit.c | 29 ++++++++++++++++-------------
1 files changed, 16 insertions(+), 13 deletions(-)
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 7c068c1..d6aeb1f 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -701,6 +701,16 @@ start_journal_io:
}
}
+ err = journal_finish_inode_data_buffers(journal, commit_transaction);
+ if (err) {
+ printk(KERN_WARNING
+ "JBD2: Detected IO errors while flushing file data "
+ "on %s\n", journal->j_devname);
+ if (journal->j_flags & JBD2_ABORT_ON_SYNCDATA_ERR)
+ jbd2_journal_abort(journal, err);
+ err = 0;
+ }
+
/*
* If the journal is not located on the file system device,
* then we must flush the file system device before we issue
@@ -719,19 +729,6 @@ start_journal_io:
&cbh, crc32_sum);
if (err)
__jbd2_journal_abort_hard(journal);
- if (journal->j_flags & JBD2_BARRIER)
- blkdev_issue_flush(journal->j_dev, GFP_KERNEL, NULL,
- BLKDEV_IFL_WAIT);
- }
-
- err = journal_finish_inode_data_buffers(journal, commit_transaction);
- if (err) {
- printk(KERN_WARNING
- "JBD2: Detected IO errors while flushing file data "
- "on %s\n", journal->j_devname);
- if (journal->j_flags & JBD2_ABORT_ON_SYNCDATA_ERR)
- jbd2_journal_abort(journal, err);
- err = 0;
}
/* Lo and behold: we have just managed to send a transaction to
@@ -845,6 +842,12 @@ wait_for_iobuf:
}
if (!err && !is_journal_aborted(journal))
err = journal_wait_on_commit_record(journal, cbh);
+ if (JBD2_HAS_INCOMPAT_FEATURE(journal,
+ JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT) &&
+ journal->j_flags & JBD2_BARRIER) {
+ blkdev_issue_flush(journal->j_dev, GFP_KERNEL, NULL,
+ BLKDEV_IFL_WAIT);
+ }
if (err)
jbd2_journal_abort(journal, err);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 35/41] jbd2: replace barriers with explicit flush / FUA usage
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
Switch to the WRITE_FLUSH_FUA flag for journal commits and remove the
EOPNOTSUPP detection for barriers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/jbd2/commit.c | 43 ++++---------------------------------------
1 files changed, 4 insertions(+), 39 deletions(-)
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index d6aeb1f..f204e27 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -134,25 +134,11 @@ static int journal_submit_commit_record(journal_t *journal,
if (journal->j_flags & JBD2_BARRIER &&
!JBD2_HAS_INCOMPAT_FEATURE(journal,
- JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
- ret = submit_bh(WRITE_SYNC_PLUG | WRITE_BARRIER, bh);
- if (ret == -EOPNOTSUPP) {
- printk(KERN_WARNING
- "JBD2: Disabling barriers on %s, "
- "not supported by device\n", journal->j_devname);
- write_lock(&journal->j_state_lock);
- journal->j_flags &= ~JBD2_BARRIER;
- write_unlock(&journal->j_state_lock);
-
- /* And try again, without the barrier */
- lock_buffer(bh);
- set_buffer_uptodate(bh);
- clear_buffer_dirty(bh);
- ret = submit_bh(WRITE_SYNC_PLUG, bh);
- }
- } else {
+ JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT))
+ ret = submit_bh(WRITE_SYNC_PLUG | WRITE_FLUSH_FUA, bh);
+ else
ret = submit_bh(WRITE_SYNC_PLUG, bh);
- }
+
*cbh = bh;
return ret;
}
@@ -166,29 +152,8 @@ static int journal_wait_on_commit_record(journal_t *journal,
{
int ret = 0;
-retry:
clear_buffer_dirty(bh);
wait_on_buffer(bh);
- if (buffer_eopnotsupp(bh) && (journal->j_flags & JBD2_BARRIER)) {
- printk(KERN_WARNING
- "JBD2: %s: disabling barries on %s - not supported "
- "by device\n", __func__, journal->j_devname);
- write_lock(&journal->j_state_lock);
- journal->j_flags &= ~JBD2_BARRIER;
- write_unlock(&journal->j_state_lock);
-
- lock_buffer(bh);
- clear_buffer_dirty(bh);
- set_buffer_uptodate(bh);
- bh->b_end_io = journal_end_buffer_io_sync;
-
- ret = submit_bh(WRITE_SYNC_PLUG, bh);
- if (ret) {
- unlock_buffer(bh);
- return ret;
- }
- goto retry;
- }
if (unlikely(!buffer_uptodate(bh)))
ret = -EIO;
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 35/41] jbd2: replace barriers with explicit flush / FUA usage
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
Switch to the WRITE_FLUSH_FUA flag for journal commits and remove the
EOPNOTSUPP detection for barriers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/jbd2/commit.c | 43 ++++---------------------------------------
1 files changed, 4 insertions(+), 39 deletions(-)
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index d6aeb1f..f204e27 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -134,25 +134,11 @@ static int journal_submit_commit_record(journal_t *journal,
if (journal->j_flags & JBD2_BARRIER &&
!JBD2_HAS_INCOMPAT_FEATURE(journal,
- JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
- ret = submit_bh(WRITE_SYNC_PLUG | WRITE_BARRIER, bh);
- if (ret == -EOPNOTSUPP) {
- printk(KERN_WARNING
- "JBD2: Disabling barriers on %s, "
- "not supported by device\n", journal->j_devname);
- write_lock(&journal->j_state_lock);
- journal->j_flags &= ~JBD2_BARRIER;
- write_unlock(&journal->j_state_lock);
-
- /* And try again, without the barrier */
- lock_buffer(bh);
- set_buffer_uptodate(bh);
- clear_buffer_dirty(bh);
- ret = submit_bh(WRITE_SYNC_PLUG, bh);
- }
- } else {
+ JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT))
+ ret = submit_bh(WRITE_SYNC_PLUG | WRITE_FLUSH_FUA, bh);
+ else
ret = submit_bh(WRITE_SYNC_PLUG, bh);
- }
+
*cbh = bh;
return ret;
}
@@ -166,29 +152,8 @@ static int journal_wait_on_commit_record(journal_t *journal,
{
int ret = 0;
-retry:
clear_buffer_dirty(bh);
wait_on_buffer(bh);
- if (buffer_eopnotsupp(bh) && (journal->j_flags & JBD2_BARRIER)) {
- printk(KERN_WARNING
- "JBD2: %s: disabling barries on %s - not supported "
- "by device\n", __func__, journal->j_devname);
- write_lock(&journal->j_state_lock);
- journal->j_flags &= ~JBD2_BARRIER;
- write_unlock(&journal->j_state_lock);
-
- lock_buffer(bh);
- clear_buffer_dirty(bh);
- set_buffer_uptodate(bh);
- bh->b_end_io = journal_end_buffer_io_sync;
-
- ret = submit_bh(WRITE_SYNC_PLUG, bh);
- if (ret) {
- unlock_buffer(bh);
- return ret;
- }
- goto retry;
- }
if (unlikely(!buffer_uptodate(bh)))
ret = -EIO;
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 35/41] jbd2: replace barriers with explicit flush / FUA usage
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
Switch to the WRITE_FLUSH_FUA flag for journal commits and remove the
EOPNOTSUPP detection for barriers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/jbd2/commit.c | 43 ++++---------------------------------------
1 files changed, 4 insertions(+), 39 deletions(-)
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index d6aeb1f..f204e27 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -134,25 +134,11 @@ static int journal_submit_commit_record(journal_t *journal,
if (journal->j_flags & JBD2_BARRIER &&
!JBD2_HAS_INCOMPAT_FEATURE(journal,
- JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
- ret = submit_bh(WRITE_SYNC_PLUG | WRITE_BARRIER, bh);
- if (ret == -EOPNOTSUPP) {
- printk(KERN_WARNING
- "JBD2: Disabling barriers on %s, "
- "not supported by device\n", journal->j_devname);
- write_lock(&journal->j_state_lock);
- journal->j_flags &= ~JBD2_BARRIER;
- write_unlock(&journal->j_state_lock);
-
- /* And try again, without the barrier */
- lock_buffer(bh);
- set_buffer_uptodate(bh);
- clear_buffer_dirty(bh);
- ret = submit_bh(WRITE_SYNC_PLUG, bh);
- }
- } else {
+ JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT))
+ ret = submit_bh(WRITE_SYNC_PLUG | WRITE_FLUSH_FUA, bh);
+ else
ret = submit_bh(WRITE_SYNC_PLUG, bh);
- }
+
*cbh = bh;
return ret;
}
@@ -166,29 +152,8 @@ static int journal_wait_on_commit_record(journal_t *journal,
{
int ret = 0;
-retry:
clear_buffer_dirty(bh);
wait_on_buffer(bh);
- if (buffer_eopnotsupp(bh) && (journal->j_flags & JBD2_BARRIER)) {
- printk(KERN_WARNING
- "JBD2: %s: disabling barries on %s - not supported "
- "by device\n", __func__, journal->j_devname);
- write_lock(&journal->j_state_lock);
- journal->j_flags &= ~JBD2_BARRIER;
- write_unlock(&journal->j_state_lock);
-
- lock_buffer(bh);
- clear_buffer_dirty(bh);
- set_buffer_uptodate(bh);
- bh->b_end_io = journal_end_buffer_io_sync;
-
- ret = submit_bh(WRITE_SYNC_PLUG, bh);
- if (ret) {
- unlock_buffer(bh);
- return ret;
- }
- goto retry;
- }
if (unlikely(!buffer_uptodate(bh)))
ret = -EIO;
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 36/41] ext4: do not send discards as barriers
2010-09-03 10:29 ` Tejun Heo
` (48 preceding siblings ...)
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
ext4 already uses synchronous discards, no need to add I/O barriers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/ext4/mballoc.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index df44b34..a22bfef 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2567,7 +2567,7 @@ static inline void ext4_issue_discard(struct super_block *sb,
trace_ext4_discard_blocks(sb,
(unsigned long long) discard_block, count);
ret = sb_issue_discard(sb, discard_block, count, GFP_NOFS,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ BLKDEV_IFL_WAIT);
if (ret == EOPNOTSUPP) {
ext4_warning(sb, "discard not supported, disabling");
clear_opt(EXT4_SB(sb)->s_mount_opt, DISCARD);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 36/41] ext4: do not send discards as barriers
2010-09-03 10:29 ` Tejun Heo
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
ext4 already uses synchronous discards, no need to add I/O barriers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/ext4/mballoc.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index df44b34..a22bfef 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2567,7 +2567,7 @@ static inline void ext4_issue_discard(struct super_block *sb,
trace_ext4_discard_blocks(sb,
(unsigned long long) discard_block, count);
ret = sb_issue_discard(sb, discard_block, count, GFP_NOFS,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ BLKDEV_IFL_WAIT);
if (ret == EOPNOTSUPP) {
ext4_warning(sb, "discard not supported, disabling");
clear_opt(EXT4_SB(sb)->s_mount_opt, DISCARD);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 36/41] ext4: do not send discards as barriers
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
ext4 already uses synchronous discards, no need to add I/O barriers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/ext4/mballoc.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index df44b34..a22bfef 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2567,7 +2567,7 @@ static inline void ext4_issue_discard(struct super_block *sb,
trace_ext4_discard_blocks(sb,
(unsigned long long) discard_block, count);
ret = sb_issue_discard(sb, discard_block, count, GFP_NOFS,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ BLKDEV_IFL_WAIT);
if (ret == EOPNOTSUPP) {
ext4_warning(sb, "discard not supported, disabling");
clear_opt(EXT4_SB(sb)->s_mount_opt, DISCARD);
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 37/41] fat: do not send discards as barriers
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
fat already uses synchronous discards, no need to add I/O barriers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/fat/fatent.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c
index 3a56a82..f9a0b7a 100644
--- a/fs/fat/fatent.c
+++ b/fs/fat/fatent.c
@@ -579,7 +579,7 @@ int fat_free_clusters(struct inode *inode, int cluster)
fat_clus_to_blknr(sbi, first_cl),
nr_clus * sbi->sec_per_clus,
GFP_NOFS,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ BLKDEV_IFL_WAIT);
first_cl = cluster;
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 37/41] fat: do not send discards as barriers
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
fat already uses synchronous discards, no need to add I/O barriers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/fat/fatent.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c
index 3a56a82..f9a0b7a 100644
--- a/fs/fat/fatent.c
+++ b/fs/fat/fatent.c
@@ -579,7 +579,7 @@ int fat_free_clusters(struct inode *inode, int cluster)
fat_clus_to_blknr(sbi, first_cl),
nr_clus * sbi->sec_per_clus,
GFP_NOFS,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ BLKDEV_IFL_WAIT);
first_cl = cluster;
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 37/41] fat: do not send discards as barriers
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
fat already uses synchronous discards, no need to add I/O barriers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/fat/fatent.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c
index 3a56a82..f9a0b7a 100644
--- a/fs/fat/fatent.c
+++ b/fs/fat/fatent.c
@@ -579,7 +579,7 @@ int fat_free_clusters(struct inode *inode, int cluster)
fat_clus_to_blknr(sbi, first_cl),
nr_clus * sbi->sec_per_clus,
GFP_NOFS,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ BLKDEV_IFL_WAIT);
first_cl = cluster;
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 38/41] swap: do not send discards as barriers
2010-09-03 10:29 ` Tejun Heo
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
The swap code already uses synchronous discards, no need to add I/O barriers.
tj: superflous newlines removed.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Hugh Dickins <hughd@google.com>
Tested-by: Nigel Cunningham <nigel@tuxonice.net>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
mm/swapfile.c | 9 +++------
1 files changed, 3 insertions(+), 6 deletions(-)
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 1f3f9c5..68cda16 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -141,8 +141,7 @@ static int discard_swap(struct swap_info_struct *si)
nr_blocks = ((sector_t)se->nr_pages - 1) << (PAGE_SHIFT - 9);
if (nr_blocks) {
err = blkdev_issue_discard(si->bdev, start_block,
- nr_blocks, GFP_KERNEL,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ nr_blocks, GFP_KERNEL, BLKDEV_IFL_WAIT);
if (err)
return err;
cond_resched();
@@ -153,8 +152,7 @@ static int discard_swap(struct swap_info_struct *si)
nr_blocks = (sector_t)se->nr_pages << (PAGE_SHIFT - 9);
err = blkdev_issue_discard(si->bdev, start_block,
- nr_blocks, GFP_KERNEL,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ nr_blocks, GFP_KERNEL, BLKDEV_IFL_WAIT);
if (err)
break;
@@ -193,8 +191,7 @@ static void discard_swap_cluster(struct swap_info_struct *si,
start_block <<= PAGE_SHIFT - 9;
nr_blocks <<= PAGE_SHIFT - 9;
if (blkdev_issue_discard(si->bdev, start_block,
- nr_blocks, GFP_NOIO, BLKDEV_IFL_WAIT |
- BLKDEV_IFL_BARRIER))
+ nr_blocks, GFP_NOIO, BLKDEV_IFL_WAIT))
break;
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 38/41] swap: do not send discards as barriers
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
The swap code already uses synchronous discards, no need to add I/O barriers.
tj: superflous newlines removed.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Hugh Dickins <hughd@google.com>
Tested-by: Nigel Cunningham <nigel@tuxonice.net>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
mm/swapfile.c | 9 +++------
1 files changed, 3 insertions(+), 6 deletions(-)
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 1f3f9c5..68cda16 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -141,8 +141,7 @@ static int discard_swap(struct swap_info_struct *si)
nr_blocks = ((sector_t)se->nr_pages - 1) << (PAGE_SHIFT - 9);
if (nr_blocks) {
err = blkdev_issue_discard(si->bdev, start_block,
- nr_blocks, GFP_KERNEL,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ nr_blocks, GFP_KERNEL, BLKDEV_IFL_WAIT);
if (err)
return err;
cond_resched();
@@ -153,8 +152,7 @@ static int discard_swap(struct swap_info_struct *si)
nr_blocks = (sector_t)se->nr_pages << (PAGE_SHIFT - 9);
err = blkdev_issue_discard(si->bdev, start_block,
- nr_blocks, GFP_KERNEL,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ nr_blocks, GFP_KERNEL, BLKDEV_IFL_WAIT);
if (err)
break;
@@ -193,8 +191,7 @@ static void discard_swap_cluster(struct swap_info_struct *si,
start_block <<= PAGE_SHIFT - 9;
nr_blocks <<= PAGE_SHIFT - 9;
if (blkdev_issue_discard(si->bdev, start_block,
- nr_blocks, GFP_NOIO, BLKDEV_IFL_WAIT |
- BLKDEV_IFL_BARRIER))
+ nr_blocks, GFP_NOIO, BLKDEV_IFL_WAIT))
break;
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 38/41] swap: do not send discards as barriers
2010-09-03 10:29 ` Tejun Heo
` (52 preceding siblings ...)
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
The swap code already uses synchronous discards, no need to add I/O barriers.
tj: superflous newlines removed.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Hugh Dickins <hughd@google.com>
Tested-by: Nigel Cunningham <nigel@tuxonice.net>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
mm/swapfile.c | 9 +++------
1 files changed, 3 insertions(+), 6 deletions(-)
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 1f3f9c5..68cda16 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -141,8 +141,7 @@ static int discard_swap(struct swap_info_struct *si)
nr_blocks = ((sector_t)se->nr_pages - 1) << (PAGE_SHIFT - 9);
if (nr_blocks) {
err = blkdev_issue_discard(si->bdev, start_block,
- nr_blocks, GFP_KERNEL,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ nr_blocks, GFP_KERNEL, BLKDEV_IFL_WAIT);
if (err)
return err;
cond_resched();
@@ -153,8 +152,7 @@ static int discard_swap(struct swap_info_struct *si)
nr_blocks = (sector_t)se->nr_pages << (PAGE_SHIFT - 9);
err = blkdev_issue_discard(si->bdev, start_block,
- nr_blocks, GFP_KERNEL,
- BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+ nr_blocks, GFP_KERNEL, BLKDEV_IFL_WAIT);
if (err)
break;
@@ -193,8 +191,7 @@ static void discard_swap_cluster(struct swap_info_struct *si,
start_block <<= PAGE_SHIFT - 9;
nr_blocks <<= PAGE_SHIFT - 9;
if (blkdev_issue_discard(si->bdev, start_block,
- nr_blocks, GFP_NOIO, BLKDEV_IFL_WAIT |
- BLKDEV_IFL_BARRIER))
+ nr_blocks, GFP_NOIO, BLKDEV_IFL_WAIT))
break;
}
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 39/41] block: remove the WRITE_BARRIER flag
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
It's unused now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
include/linux/fs.h | 3 ---
1 files changed, 0 insertions(+), 3 deletions(-)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 352c486..d6add69 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -135,7 +135,6 @@ struct inodes_stat_t {
* immediately after submission. The write equivalent
* of READ_SYNC.
* WRITE_ODIRECT_PLUG Special case write for O_DIRECT only.
- * WRITE_BARRIER DEPRECATED. Always fails. Use FLUSH/FUA instead.
* WRITE_FLUSH Like WRITE_SYNC but with preceding cache flush.
* WRITE_FUA Like WRITE_SYNC but data is guaranteed to be on
* non-volatile media on completion.
@@ -157,8 +156,6 @@ struct inodes_stat_t {
#define WRITE_SYNC (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG)
#define WRITE_ODIRECT_PLUG (WRITE | REQ_SYNC)
#define WRITE_META (WRITE | REQ_META)
-#define WRITE_BARRIER (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
- REQ_HARDBARRIER)
#define WRITE_FLUSH (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
REQ_FLUSH)
#define WRITE_FUA (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 39/41] block: remove the WRITE_BARRIER flag
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
It's unused now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
include/linux/fs.h | 3 ---
1 files changed, 0 insertions(+), 3 deletions(-)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 352c486..d6add69 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -135,7 +135,6 @@ struct inodes_stat_t {
* immediately after submission. The write equivalent
* of READ_SYNC.
* WRITE_ODIRECT_PLUG Special case write for O_DIRECT only.
- * WRITE_BARRIER DEPRECATED. Always fails. Use FLUSH/FUA instead.
* WRITE_FLUSH Like WRITE_SYNC but with preceding cache flush.
* WRITE_FUA Like WRITE_SYNC but data is guaranteed to be on
* non-volatile media on completion.
@@ -157,8 +156,6 @@ struct inodes_stat_t {
#define WRITE_SYNC (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG)
#define WRITE_ODIRECT_PLUG (WRITE | REQ_SYNC)
#define WRITE_META (WRITE | REQ_META)
-#define WRITE_BARRIER (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
- REQ_HARDBARRIER)
#define WRITE_FLUSH (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
REQ_FLUSH)
#define WRITE_FUA (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 39/41] block: remove the WRITE_BARRIER flag
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
It's unused now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
include/linux/fs.h | 3 ---
1 files changed, 0 insertions(+), 3 deletions(-)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 352c486..d6add69 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -135,7 +135,6 @@ struct inodes_stat_t {
* immediately after submission. The write equivalent
* of READ_SYNC.
* WRITE_ODIRECT_PLUG Special case write for O_DIRECT only.
- * WRITE_BARRIER DEPRECATED. Always fails. Use FLUSH/FUA instead.
* WRITE_FLUSH Like WRITE_SYNC but with preceding cache flush.
* WRITE_FUA Like WRITE_SYNC but data is guaranteed to be on
* non-volatile media on completion.
@@ -157,8 +156,6 @@ struct inodes_stat_t {
#define WRITE_SYNC (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG)
#define WRITE_ODIRECT_PLUG (WRITE | REQ_SYNC)
#define WRITE_META (WRITE | REQ_META)
-#define WRITE_BARRIER (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
- REQ_HARDBARRIER)
#define WRITE_FLUSH (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
REQ_FLUSH)
#define WRITE_FUA (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 40/41] block: remove the BLKDEV_IFL_BARRIER flag
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
Remove support for barriers on discards, which is unused now. Also
remove the DISCARD_NOBARRIER I/O type in favour of just setting the
rw flags up locally in blkdev_issue_discard.
tj: Also remove DISCARD_SECURE and use REQ_SECURE directly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
block/blk-lib.c | 18 ++----------------
include/linux/blkdev.h | 2 --
include/linux/fs.h | 8 --------
3 files changed, 2 insertions(+), 26 deletions(-)
diff --git a/block/blk-lib.c b/block/blk-lib.c
index c392029..fe2e6ed 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -39,8 +39,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
{
DECLARE_COMPLETION_ONSTACK(wait);
struct request_queue *q = bdev_get_queue(bdev);
- int type = flags & BLKDEV_IFL_BARRIER ?
- DISCARD_BARRIER : DISCARD_NOBARRIER;
+ int type = REQ_WRITE | REQ_DISCARD;
unsigned int max_discard_sectors;
struct bio *bio;
int ret = 0;
@@ -65,7 +64,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
if (flags & BLKDEV_IFL_SECURE) {
if (!blk_queue_secdiscard(q))
return -EOPNOTSUPP;
- type |= DISCARD_SECURE;
+ type |= REQ_SECURE;
}
while (nr_sects && !ret) {
@@ -162,12 +161,6 @@ int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
bb.wait = &wait;
bb.end_io = NULL;
- if (flags & BLKDEV_IFL_BARRIER) {
- /* issue async barrier before the data */
- ret = blkdev_issue_flush(bdev, gfp_mask, NULL, 0);
- if (ret)
- return ret;
- }
submit:
ret = 0;
while (nr_sects != 0) {
@@ -199,13 +192,6 @@ submit:
issued++;
submit_bio(WRITE, bio);
}
- /*
- * When all data bios are in flight. Send final barrier if requeted.
- */
- if (nr_sects == 0 && flags & BLKDEV_IFL_BARRIER)
- ret = blkdev_issue_flush(bdev, gfp_mask, NULL,
- flags & BLKDEV_IFL_WAIT);
-
if (flags & BLKDEV_IFL_WAIT)
/* Wait for bios in-flight */
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 6b305eb..cfcb3a6 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -869,11 +869,9 @@ static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
}
enum{
BLKDEV_WAIT, /* wait for completion */
- BLKDEV_BARRIER, /* issue request with barrier */
BLKDEV_SECURE, /* secure discard */
};
#define BLKDEV_IFL_WAIT (1 << BLKDEV_WAIT)
-#define BLKDEV_IFL_BARRIER (1 << BLKDEV_BARRIER)
#define BLKDEV_IFL_SECURE (1 << BLKDEV_SECURE)
extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *,
unsigned long);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index d6add69..6b0f6e9 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -163,14 +163,6 @@ struct inodes_stat_t {
#define WRITE_FLUSH_FUA (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
REQ_FLUSH | REQ_FUA)
-/*
- * These aren't really reads or writes, they pass down information about
- * parts of device that are now unused by the file system.
- */
-#define DISCARD_NOBARRIER (WRITE | REQ_DISCARD)
-#define DISCARD_BARRIER (WRITE | REQ_DISCARD | REQ_HARDBARRIER)
-#define DISCARD_SECURE (DISCARD_NOBARRIER | REQ_SECURE)
-
#define SEL_IN 1
#define SEL_OUT 2
#define SEL_EX 4
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 40/41] block: remove the BLKDEV_IFL_BARRIER flag
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
Remove support for barriers on discards, which is unused now. Also
remove the DISCARD_NOBARRIER I/O type in favour of just setting the
rw flags up locally in blkdev_issue_discard.
tj: Also remove DISCARD_SECURE and use REQ_SECURE directly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
block/blk-lib.c | 18 ++----------------
include/linux/blkdev.h | 2 --
include/linux/fs.h | 8 --------
3 files changed, 2 insertions(+), 26 deletions(-)
diff --git a/block/blk-lib.c b/block/blk-lib.c
index c392029..fe2e6ed 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -39,8 +39,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
{
DECLARE_COMPLETION_ONSTACK(wait);
struct request_queue *q = bdev_get_queue(bdev);
- int type = flags & BLKDEV_IFL_BARRIER ?
- DISCARD_BARRIER : DISCARD_NOBARRIER;
+ int type = REQ_WRITE | REQ_DISCARD;
unsigned int max_discard_sectors;
struct bio *bio;
int ret = 0;
@@ -65,7 +64,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
if (flags & BLKDEV_IFL_SECURE) {
if (!blk_queue_secdiscard(q))
return -EOPNOTSUPP;
- type |= DISCARD_SECURE;
+ type |= REQ_SECURE;
}
while (nr_sects && !ret) {
@@ -162,12 +161,6 @@ int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
bb.wait = &wait;
bb.end_io = NULL;
- if (flags & BLKDEV_IFL_BARRIER) {
- /* issue async barrier before the data */
- ret = blkdev_issue_flush(bdev, gfp_mask, NULL, 0);
- if (ret)
- return ret;
- }
submit:
ret = 0;
while (nr_sects != 0) {
@@ -199,13 +192,6 @@ submit:
issued++;
submit_bio(WRITE, bio);
}
- /*
- * When all data bios are in flight. Send final barrier if requeted.
- */
- if (nr_sects == 0 && flags & BLKDEV_IFL_BARRIER)
- ret = blkdev_issue_flush(bdev, gfp_mask, NULL,
- flags & BLKDEV_IFL_WAIT);
-
if (flags & BLKDEV_IFL_WAIT)
/* Wait for bios in-flight */
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 6b305eb..cfcb3a6 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -869,11 +869,9 @@ static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
}
enum{
BLKDEV_WAIT, /* wait for completion */
- BLKDEV_BARRIER, /* issue request with barrier */
BLKDEV_SECURE, /* secure discard */
};
#define BLKDEV_IFL_WAIT (1 << BLKDEV_WAIT)
-#define BLKDEV_IFL_BARRIER (1 << BLKDEV_BARRIER)
#define BLKDEV_IFL_SECURE (1 << BLKDEV_SECURE)
extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *,
unsigned long);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index d6add69..6b0f6e9 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -163,14 +163,6 @@ struct inodes_stat_t {
#define WRITE_FLUSH_FUA (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
REQ_FLUSH | REQ_FUA)
-/*
- * These aren't really reads or writes, they pass down information about
- * parts of device that are now unused by the file system.
- */
-#define DISCARD_NOBARRIER (WRITE | REQ_DISCARD)
-#define DISCARD_BARRIER (WRITE | REQ_DISCARD | REQ_HARDBARRIER)
-#define DISCARD_SECURE (DISCARD_NOBARRIER | REQ_SECURE)
-
#define SEL_IN 1
#define SEL_OUT 2
#define SEL_EX 4
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 40/41] block: remove the BLKDEV_IFL_BARRIER flag
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
Remove support for barriers on discards, which is unused now. Also
remove the DISCARD_NOBARRIER I/O type in favour of just setting the
rw flags up locally in blkdev_issue_discard.
tj: Also remove DISCARD_SECURE and use REQ_SECURE directly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
block/blk-lib.c | 18 ++----------------
include/linux/blkdev.h | 2 --
include/linux/fs.h | 8 --------
3 files changed, 2 insertions(+), 26 deletions(-)
diff --git a/block/blk-lib.c b/block/blk-lib.c
index c392029..fe2e6ed 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -39,8 +39,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
{
DECLARE_COMPLETION_ONSTACK(wait);
struct request_queue *q = bdev_get_queue(bdev);
- int type = flags & BLKDEV_IFL_BARRIER ?
- DISCARD_BARRIER : DISCARD_NOBARRIER;
+ int type = REQ_WRITE | REQ_DISCARD;
unsigned int max_discard_sectors;
struct bio *bio;
int ret = 0;
@@ -65,7 +64,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
if (flags & BLKDEV_IFL_SECURE) {
if (!blk_queue_secdiscard(q))
return -EOPNOTSUPP;
- type |= DISCARD_SECURE;
+ type |= REQ_SECURE;
}
while (nr_sects && !ret) {
@@ -162,12 +161,6 @@ int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
bb.wait = &wait;
bb.end_io = NULL;
- if (flags & BLKDEV_IFL_BARRIER) {
- /* issue async barrier before the data */
- ret = blkdev_issue_flush(bdev, gfp_mask, NULL, 0);
- if (ret)
- return ret;
- }
submit:
ret = 0;
while (nr_sects != 0) {
@@ -199,13 +192,6 @@ submit:
issued++;
submit_bio(WRITE, bio);
}
- /*
- * When all data bios are in flight. Send final barrier if requeted.
- */
- if (nr_sects == 0 && flags & BLKDEV_IFL_BARRIER)
- ret = blkdev_issue_flush(bdev, gfp_mask, NULL,
- flags & BLKDEV_IFL_WAIT);
-
if (flags & BLKDEV_IFL_WAIT)
/* Wait for bios in-flight */
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 6b305eb..cfcb3a6 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -869,11 +869,9 @@ static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
}
enum{
BLKDEV_WAIT, /* wait for completion */
- BLKDEV_BARRIER, /* issue request with barrier */
BLKDEV_SECURE, /* secure discard */
};
#define BLKDEV_IFL_WAIT (1 << BLKDEV_WAIT)
-#define BLKDEV_IFL_BARRIER (1 << BLKDEV_BARRIER)
#define BLKDEV_IFL_SECURE (1 << BLKDEV_SECURE)
extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *,
unsigned long);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index d6add69..6b0f6e9 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -163,14 +163,6 @@ struct inodes_stat_t {
#define WRITE_FLUSH_FUA (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
REQ_FLUSH | REQ_FUA)
-/*
- * These aren't really reads or writes, they pass down information about
- * parts of device that are now unused by the file system.
- */
-#define DISCARD_NOBARRIER (WRITE | REQ_DISCARD)
-#define DISCARD_BARRIER (WRITE | REQ_DISCARD | REQ_HARDBARRIER)
-#define DISCARD_SECURE (DISCARD_NOBARRIER | REQ_SECURE)
-
#define SEL_IN 1
#define SEL_OUT 2
#define SEL_EX 4
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* [PATCH 41/41] block: remove the BH_Eopnotsupp flag
2010-09-03 10:29 ` Tejun Heo
(?)
@ 2010-09-03 10:29 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
This flag was only set for barrier buffers, which we don't submit
anymore.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/buffer.c | 7 +------
fs/fat/misc.c | 5 +----
include/linux/buffer_head.h | 2 --
3 files changed, 2 insertions(+), 12 deletions(-)
diff --git a/fs/buffer.c b/fs/buffer.c
index 3e7dca2..7f0b9b0 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -156,7 +156,7 @@ void end_buffer_write_sync(struct buffer_head *bh, int uptodate)
if (uptodate) {
set_buffer_uptodate(bh);
} else {
- if (!buffer_eopnotsupp(bh) && !quiet_error(bh)) {
+ if (!quiet_error(bh)) {
buffer_io_error(bh);
printk(KERN_WARNING "lost page write due to "
"I/O error on %s\n",
@@ -2891,7 +2891,6 @@ static void end_bio_bh_io_sync(struct bio *bio, int err)
if (err == -EOPNOTSUPP) {
set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
- set_bit(BH_Eopnotsupp, &bh->b_state);
}
if (unlikely (test_bit(BIO_QUIET,&bio->bi_flags)))
@@ -3031,10 +3030,6 @@ int __sync_dirty_buffer(struct buffer_head *bh, int rw)
bh->b_end_io = end_buffer_write_sync;
ret = submit_bh(rw, bh);
wait_on_buffer(bh);
- if (buffer_eopnotsupp(bh)) {
- clear_buffer_eopnotsupp(bh);
- ret = -EOPNOTSUPP;
- }
if (!ret && !buffer_uptodate(bh))
ret = -EIO;
} else {
diff --git a/fs/fat/misc.c b/fs/fat/misc.c
index 1736f23..970e682 100644
--- a/fs/fat/misc.c
+++ b/fs/fat/misc.c
@@ -255,10 +255,7 @@ int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs)
for (i = 0; i < nr_bhs; i++) {
wait_on_buffer(bhs[i]);
- if (buffer_eopnotsupp(bhs[i])) {
- clear_buffer_eopnotsupp(bhs[i]);
- err = -EOPNOTSUPP;
- } else if (!err && !buffer_uptodate(bhs[i]))
+ if (!err && !buffer_uptodate(bhs[i]))
err = -EIO;
}
return err;
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index fc999f5..dd1b25b 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -32,7 +32,6 @@ enum bh_state_bits {
BH_Delay, /* Buffer is not yet allocated on disk */
BH_Boundary, /* Block is followed by a discontiguity */
BH_Write_EIO, /* I/O error on write */
- BH_Eopnotsupp, /* DEPRECATED: operation not supported (barrier) */
BH_Unwritten, /* Buffer is allocated on disk but not written */
BH_Quiet, /* Buffer Error Prinks to be quiet */
@@ -124,7 +123,6 @@ BUFFER_FNS(Async_Write, async_write)
BUFFER_FNS(Delay, delay)
BUFFER_FNS(Boundary, boundary)
BUFFER_FNS(Write_EIO, write_io_error)
-BUFFER_FNS(Eopnotsupp, eopnotsupp)
BUFFER_FNS(Unwritten, unwritten)
#define bh_offset(bh) ((unsigned long)(bh)->b_data & ~PAGE_MASK)
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 41/41] block: remove the BH_Eopnotsupp flag
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
This flag was only set for barrier buffers, which we don't submit
anymore.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/buffer.c | 7 +------
fs/fat/misc.c | 5 +----
include/linux/buffer_head.h | 2 --
3 files changed, 2 insertions(+), 12 deletions(-)
diff --git a/fs/buffer.c b/fs/buffer.c
index 3e7dca2..7f0b9b0 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -156,7 +156,7 @@ void end_buffer_write_sync(struct buffer_head *bh, int uptodate)
if (uptodate) {
set_buffer_uptodate(bh);
} else {
- if (!buffer_eopnotsupp(bh) && !quiet_error(bh)) {
+ if (!quiet_error(bh)) {
buffer_io_error(bh);
printk(KERN_WARNING "lost page write due to "
"I/O error on %s\n",
@@ -2891,7 +2891,6 @@ static void end_bio_bh_io_sync(struct bio *bio, int err)
if (err == -EOPNOTSUPP) {
set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
- set_bit(BH_Eopnotsupp, &bh->b_state);
}
if (unlikely (test_bit(BIO_QUIET,&bio->bi_flags)))
@@ -3031,10 +3030,6 @@ int __sync_dirty_buffer(struct buffer_head *bh, int rw)
bh->b_end_io = end_buffer_write_sync;
ret = submit_bh(rw, bh);
wait_on_buffer(bh);
- if (buffer_eopnotsupp(bh)) {
- clear_buffer_eopnotsupp(bh);
- ret = -EOPNOTSUPP;
- }
if (!ret && !buffer_uptodate(bh))
ret = -EIO;
} else {
diff --git a/fs/fat/misc.c b/fs/fat/misc.c
index 1736f23..970e682 100644
--- a/fs/fat/misc.c
+++ b/fs/fat/misc.c
@@ -255,10 +255,7 @@ int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs)
for (i = 0; i < nr_bhs; i++) {
wait_on_buffer(bhs[i]);
- if (buffer_eopnotsupp(bhs[i])) {
- clear_buffer_eopnotsupp(bhs[i]);
- err = -EOPNOTSUPP;
- } else if (!err && !buffer_uptodate(bhs[i]))
+ if (!err && !buffer_uptodate(bhs[i]))
err = -EIO;
}
return err;
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index fc999f5..dd1b25b 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -32,7 +32,6 @@ enum bh_state_bits {
BH_Delay, /* Buffer is not yet allocated on disk */
BH_Boundary, /* Block is followed by a discontiguity */
BH_Write_EIO, /* I/O error on write */
- BH_Eopnotsupp, /* DEPRECATED: operation not supported (barrier) */
BH_Unwritten, /* Buffer is allocated on disk but not written */
BH_Quiet, /* Buffer Error Prinks to be quiet */
@@ -124,7 +123,6 @@ BUFFER_FNS(Async_Write, async_write)
BUFFER_FNS(Delay, delay)
BUFFER_FNS(Boundary, boundary)
BUFFER_FNS(Write_EIO, write_io_error)
-BUFFER_FNS(Eopnotsupp, eopnotsupp)
BUFFER_FNS(Unwritten, unwritten)
#define bh_offset(bh) ((unsigned long)(bh)->b_data & ~PAGE_MASK)
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread* [PATCH 41/41] block: remove the BH_Eopnotsupp flag
@ 2010-09-03 10:29 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-03 10:29 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Cc: Christoph Hellwig, Tejun Heo
From: Christoph Hellwig <hch@infradead.org>
This flag was only set for barrier buffers, which we don't submit
anymore.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/buffer.c | 7 +------
fs/fat/misc.c | 5 +----
include/linux/buffer_head.h | 2 --
3 files changed, 2 insertions(+), 12 deletions(-)
diff --git a/fs/buffer.c b/fs/buffer.c
index 3e7dca2..7f0b9b0 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -156,7 +156,7 @@ void end_buffer_write_sync(struct buffer_head *bh, int uptodate)
if (uptodate) {
set_buffer_uptodate(bh);
} else {
- if (!buffer_eopnotsupp(bh) && !quiet_error(bh)) {
+ if (!quiet_error(bh)) {
buffer_io_error(bh);
printk(KERN_WARNING "lost page write due to "
"I/O error on %s\n",
@@ -2891,7 +2891,6 @@ static void end_bio_bh_io_sync(struct bio *bio, int err)
if (err == -EOPNOTSUPP) {
set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
- set_bit(BH_Eopnotsupp, &bh->b_state);
}
if (unlikely (test_bit(BIO_QUIET,&bio->bi_flags)))
@@ -3031,10 +3030,6 @@ int __sync_dirty_buffer(struct buffer_head *bh, int rw)
bh->b_end_io = end_buffer_write_sync;
ret = submit_bh(rw, bh);
wait_on_buffer(bh);
- if (buffer_eopnotsupp(bh)) {
- clear_buffer_eopnotsupp(bh);
- ret = -EOPNOTSUPP;
- }
if (!ret && !buffer_uptodate(bh))
ret = -EIO;
} else {
diff --git a/fs/fat/misc.c b/fs/fat/misc.c
index 1736f23..970e682 100644
--- a/fs/fat/misc.c
+++ b/fs/fat/misc.c
@@ -255,10 +255,7 @@ int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs)
for (i = 0; i < nr_bhs; i++) {
wait_on_buffer(bhs[i]);
- if (buffer_eopnotsupp(bhs[i])) {
- clear_buffer_eopnotsupp(bhs[i]);
- err = -EOPNOTSUPP;
- } else if (!err && !buffer_uptodate(bhs[i]))
+ if (!err && !buffer_uptodate(bhs[i]))
err = -EIO;
}
return err;
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index fc999f5..dd1b25b 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -32,7 +32,6 @@ enum bh_state_bits {
BH_Delay, /* Buffer is not yet allocated on disk */
BH_Boundary, /* Block is followed by a discontiguity */
BH_Write_EIO, /* I/O error on write */
- BH_Eopnotsupp, /* DEPRECATED: operation not supported (barrier) */
BH_Unwritten, /* Buffer is allocated on disk but not written */
BH_Quiet, /* Buffer Error Prinks to be quiet */
@@ -124,7 +123,6 @@ BUFFER_FNS(Async_Write, async_write)
BUFFER_FNS(Delay, delay)
BUFFER_FNS(Boundary, boundary)
BUFFER_FNS(Write_EIO, write_io_error)
-BUFFER_FNS(Eopnotsupp, eopnotsupp)
BUFFER_FNS(Unwritten, unwritten)
#define bh_offset(bh) ((unsigned long)(bh)->b_data & ~PAGE_MASK)
--
1.7.1
^ permalink raw reply related [flat|nested] 159+ messages in thread
* Re: [PATCHSET #upstream] block, fs: replace HARDBARRIER with FLUSH/FUA, take#2
2010-09-03 10:29 ` Tejun Heo
@ 2010-09-03 18:53 ` Jens Axboe
-1 siblings, 0 replies; 159+ messages in thread
From: Jens Axboe @ 2010-09-03 18:53 UTC (permalink / raw)
To: Tejun Heo
Cc: jack, snitzer, mst, linux-ide, dm-devel, James.Bottomley,
konishi.ryusuke, hch, k-ueda, vst, linux-scsi, rusty, linux-raid,
mpatocka, swhiteho, chris.mason, tytso
On 09/03/2010 12:29 PM, Tejun Heo wrote:
> Hello,
>
> This patchset is combination of the following two patchsets.
>
> [1] block, fs: replace HARDBARRIER with FLUSH/FUA
> [2] block, dm: finish REQ_FLUSH/FUA conversion, take#2
>
> Changes from the previous postings are
>
> * Rebased on top of v2.6.36-rc3.
>
> * 0010-block-implement-REQ_FLUSH-FUA-based-interface-for-FL.patch
> description updated to include why special -EOPNOTSUPP handling is
> no longer necessary as suggested by Mike Snitzer.
>
> * 0025-dm-relax-ordering-of-bio-based-flush-implementation.patch
> description updated to include why flush_error and special error
> handling logic are no longer necessary as suggested by Mike
> Snitzer.
>
> * 0013-block-initialize-flush-request-with-WRITE_FLUSH-inst.patch and
> 0014-block-kick-queue-after-sequencing-REQ_FLUSH-FUA.patch added.
> These fixes aren't strictly required by the current users but remove
> fishy corner cases.
>
> * 0015-block-make-sure-FSEQ_DATA-request-has-the-same-rq_di.patch
> added. This is needed to make requested based dm work.
>
> * 0026-dm-fix-locking-context-in-queue_io.patch added. This fixes
> locking context problem introduced by
> 0025-dm-relax-ordering-of-bio-based-flush-implementation.patch.
>
> * Tested/Reviewed-by's added and patches reordered such that block
> layer conversion comes first followed by block driver conversions,
> filesystem conversions and then finally removal of deprecate stuff.
>
> I think the patchset is mostly ready now although I would love to have
> acked/reviewd-by's on bio-based dm conversion patches. Jens,
> Christoph, how do you guys wanna steer these patches? I think it
> would be best to go through the block tree but splitting parts and
> doing cross tree pull/merges should be doable too.
Since the core changes are block churn, it would probably be
sanest to pull everything in there. Core into for-2.6.37/core,
then have for-2.6.37/fs and 2.6.37/drivers on top of that.
--
Jens Axboe
^ permalink raw reply [flat|nested] 159+ messages in thread
* Re: [PATCHSET #upstream] block, fs: replace HARDBARRIER with FLUSH/FUA, take#2
@ 2010-09-03 18:53 ` Jens Axboe
0 siblings, 0 replies; 159+ messages in thread
From: Jens Axboe @ 2010-09-03 18:53 UTC (permalink / raw)
To: Tejun Heo
Cc: jack, snitzer, mst, linux-ide, dm-devel, James.Bottomley,
konishi.ryusuke, hch, k-ueda, vst, linux-scsi, rusty, linux-raid,
mpatocka, swhiteho, chris.mason, tytso
On 09/03/2010 12:29 PM, Tejun Heo wrote:
> Hello,
>
> This patchset is combination of the following two patchsets.
>
> [1] block, fs: replace HARDBARRIER with FLUSH/FUA
> [2] block, dm: finish REQ_FLUSH/FUA conversion, take#2
>
> Changes from the previous postings are
>
> * Rebased on top of v2.6.36-rc3.
>
> * 0010-block-implement-REQ_FLUSH-FUA-based-interface-for-FL.patch
> description updated to include why special -EOPNOTSUPP handling is
> no longer necessary as suggested by Mike Snitzer.
>
> * 0025-dm-relax-ordering-of-bio-based-flush-implementation.patch
> description updated to include why flush_error and special error
> handling logic are no longer necessary as suggested by Mike
> Snitzer.
>
> * 0013-block-initialize-flush-request-with-WRITE_FLUSH-inst.patch and
> 0014-block-kick-queue-after-sequencing-REQ_FLUSH-FUA.patch added.
> These fixes aren't strictly required by the current users but remove
> fishy corner cases.
>
> * 0015-block-make-sure-FSEQ_DATA-request-has-the-same-rq_di.patch
> added. This is needed to make requested based dm work.
>
> * 0026-dm-fix-locking-context-in-queue_io.patch added. This fixes
> locking context problem introduced by
> 0025-dm-relax-ordering-of-bio-based-flush-implementation.patch.
>
> * Tested/Reviewed-by's added and patches reordered such that block
> layer conversion comes first followed by block driver conversions,
> filesystem conversions and then finally removal of deprecate stuff.
>
> I think the patchset is mostly ready now although I would love to have
> acked/reviewd-by's on bio-based dm conversion patches. Jens,
> Christoph, how do you guys wanna steer these patches? I think it
> would be best to go through the block tree but splitting parts and
> doing cross tree pull/merges should be doable too.
Since the core changes are block churn, it would probably be
sanest to pull everything in there. Core into for-2.6.37/core,
then have for-2.6.37/fs and 2.6.37/drivers on top of that.
--
Jens Axboe
^ permalink raw reply [flat|nested] 159+ messages in thread
* Re: [PATCHSET #upstream] block, fs: replace HARDBARRIER with FLUSH/FUA, take#2
2010-09-03 10:29 ` Tejun Heo
@ 2010-09-08 16:12 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-08 16:12 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel
Hello, Jens.
I added Mike's cleanup patch and Kiyoshi's Tested-by and updated
flush-fua branch accordingly.
git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc.git flush-fua
I guess it's about ready. Please consider pulling it into the block
tree so that it can get linux-next exposure. If you want the whole
patch series resent, please let me know.
Thanks.
--
tejun
^ permalink raw reply [flat|nested] 159+ messages in thread
* Re: [PATCHSET #upstream] block, fs: replace HARDBARRIER with FLUSH/FUA, take#2
@ 2010-09-08 16:12 ` Tejun Heo
0 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-08 16:12 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide,
linux-raid, dm-devel, hch, konishi.ryusuke, James.Bottomley,
tytso, chris.mason, swhiteho, vst, jack, rwheeler, hare, neilb,
rusty, mst, snitzer, k-ueda, mpatocka
Hello, Jens.
I added Mike's cleanup patch and Kiyoshi's Tested-by and updated
flush-fua branch accordingly.
git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc.git flush-fua
I guess it's about ready. Please consider pulling it into the block
tree so that it can get linux-next exposure. If you want the whole
patch series resent, please let me know.
Thanks.
--
tejun
^ permalink raw reply [flat|nested] 159+ messages in thread
* Re: [PATCHSET #upstream] block, fs: replace HARDBARRIER with FLUSH/FUA, take#2
2010-09-08 16:12 ` Tejun Heo
@ 2010-09-10 10:19 ` Jens Axboe
-1 siblings, 0 replies; 159+ messages in thread
From: Jens Axboe @ 2010-09-10 10:19 UTC (permalink / raw)
To: Tejun Heo
Cc: jack, snitzer, mst, linux-ide, dm-devel, James.Bottomley,
konishi.ryusuke, hch, k-ueda, vst, linux-scsi, rusty, linux-raid,
mpatocka, swhiteho, chris.mason, tytso
On 2010-09-08 18:12, Tejun Heo wrote:
> Hello, Jens.
>
> I added Mike's cleanup patch and Kiyoshi's Tested-by and updated
> flush-fua branch accordingly.
>
> git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc.git flush-fua
>
> I guess it's about ready. Please consider pulling it into the block
> tree so that it can get linux-next exposure. If you want the whole
> patch series resent, please let me know.
Thanks Tejun, I'm pulling it in now.
--
Jens Axboe
^ permalink raw reply [flat|nested] 159+ messages in thread
* Re: [PATCHSET #upstream] block, fs: replace HARDBARRIER with FLUSH/FUA, take#2
@ 2010-09-10 10:19 ` Jens Axboe
0 siblings, 0 replies; 159+ messages in thread
From: Jens Axboe @ 2010-09-10 10:19 UTC (permalink / raw)
To: Tejun Heo
Cc: jack, snitzer, mst, linux-ide, dm-devel, James.Bottomley,
konishi.ryusuke, hch, k-ueda, vst, linux-scsi, rusty, linux-raid,
mpatocka, swhiteho, chris.mason, tytso
On 2010-09-08 18:12, Tejun Heo wrote:
> Hello, Jens.
>
> I added Mike's cleanup patch and Kiyoshi's Tested-by and updated
> flush-fua branch accordingly.
>
> git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc.git flush-fua
>
> I guess it's about ready. Please consider pulling it into the block
> tree so that it can get linux-next exposure. If you want the whole
> patch series resent, please let me know.
Thanks Tejun, I'm pulling it in now.
--
Jens Axboe
^ permalink raw reply [flat|nested] 159+ messages in thread
* Re: [PATCHSET #upstream] block, fs: replace HARDBARRIER with FLUSH/FUA, take#2
2010-09-03 10:29 ` Tejun Heo
` (58 preceding siblings ...)
(?)
@ 2010-09-08 16:12 ` Tejun Heo
-1 siblings, 0 replies; 159+ messages in thread
From: Tejun Heo @ 2010-09-08 16:12 UTC (permalink / raw)
To: jaxboe, linux-kernel, linux-fsdevel, linux-scsi, linux-ide, linux-raid
Hello, Jens.
I added Mike's cleanup patch and Kiyoshi's Tested-by and updated
flush-fua branch accordingly.
git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc.git flush-fua
I guess it's about ready. Please consider pulling it into the block
tree so that it can get linux-next exposure. If you want the whole
patch series resent, please let me know.
Thanks.
--
tejun
^ permalink raw reply [flat|nested] 159+ messages in thread