linux-btrfs.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH v9 00/41] btrfs: zoned block device support
@ 2020-10-30 13:51 Naohiro Aota
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
  2020-11-03 11:54 ` [PATCH v9 00/41] btrfs: zoned block device support David Sterba
  0 siblings, 2 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

This series adds zoned block device support to btrfs.

This series is also available on github.
Kernel   https://github.com/naota/linux/tree/btrfs-zoned-v9
Userland https://github.com/naota/btrfs-progs/tree/btrfs-zoned
xfstests https://github.com/naota/fstests/tree/btrfs-zoned

Userland tool depends on patched util-linux (libblkid and wipefs) to handle
log-structured superblock. To ease the testing, pre-compiled static linked
userland tools are available here:
https://wdc.app.box.com/s/fnhqsb3otrvgkstq66o6bvdw6tk525kp

Changes from v8:
 - Direct-IO path now follow several hardware restrictions (other than
   max_zone_append_size) by using ZONE_APPEND support of iomap
 - introduces union of fs_info->zone_size and fs_info->zoned [Johannes]
   - and use btrfs_is_zoned(fs_info) in place of btrfs_fs_incompat(fs_info,
     ZONED)
 - print if zoned is enabled or not when printing module info [Johannes]
 - drop patch of disabling inode_cache on ZONED
 - moved for_teelog flag to a proper location [Johannes]
 - Code style fixes [Johannes]
 - Add comment about adding physical layer things to ordered extent
   structure
 - Pass file_offset explicitly to extract_ordered_extent() instead of
   determining it from bio
 - Bug fixes
   - write out fsync region so that the logical address of ordered extents
     and checksums are properly finalized
   - free zone_info at umount time
   - fix superblock log handling when entering zones[1] in the first time
   - fixes double free of log-tree roots [Johannes] 
   - Drop erroneous ASSERT in do_allocation_zoned()

btrfs-progs and xfstests series will follow.

This version of ZONED btrfs switched from normal write command to zone
append write command. You do not need to specify LBA (at the write pointer)
to write for zone append write command. Instead, you only select a zone to
write with its start LBA. Then the device (NVMe ZNS), or the emulation of
zone append command in the sd driver in the case of SAS or SATA HDDs,
automatically writes the data at the write pointer position and return the
written LBA as a command reply.

The benefit of using the zone append write command is that write command
issuing order does not matter. So, we can eliminate block group lock and
utilize asynchronous checksum, which can reorder the IOs.

Eliminating the lock improves performance. In particular, on a workload
with massive competing to the same zone [1], we observed 36% performance
improvement compared to normal write.

[1] Fio running 16 jobs with 4KB random writes for 5 minutes

However, there are some limitations. We cannot use the non-SINGLE profile.
Supporting non-SINGLE profile with zone append writing is not trivial. For
example, in the DUP profile, we send a zone append writing IO to two zones
on a device. The device reply with written LBAs for the IOs. If the offsets
of the returned addresses from the beginning of the zone are different,
then it results in different logical addresses.

For the same reason, we cannot issue multiple IOs for one ordered extent.
Thus, the size of an ordered extent is limited under max_zone_append_size.
This limitation will cause fragmentation and increased usage of metadata.
In the future, we can add optimization to merge ordered extents after
end_bio.

* Patch series description

A zoned block device consists of a number of zones. Zones are either
conventional and accepting random writes or sequential and requiring
that writes be issued in LBA order from each zone write pointer
position. This patch series ensures that the sequential write
constraint of sequential zones is respected while fundamentally not
changing BtrFS block and I/O management for block stored in
conventional zones.

To achieve this, the default chunk size of btrfs is changed on zoned
block devices so that chunks are always aligned to a zone. Allocation
of blocks within a chunk is changed so that the allocation is always
sequential from the beginning of the chunks. To do so, an allocation
pointer is added to block groups and used as the allocation hint.  The
allocation changes also ensure that blocks freed below the allocation
pointer are ignored, resulting in sequential block allocation
regardless of the chunk usage.

The zone of a chunk is reset to allow reuse of the zone only when the
block group is being freed, that is, when all the chunks of the block
group are unused.

For btrfs volumes composed of multiple zoned disks, a restriction is
added to ensure that all disks have the same zone size. This
restriction matches the existing constraint that all chunks in a block
group must have the same size.

* Enabling tree-log

The tree-log feature does not work on ZONED mode as is. Blocks for a
tree-log tree are allocated mixed with other metadata blocks, and btrfs
writes and syncs the tree-log blocks to devices at the time of fsync(),
which is different timing than a global transaction commit. As a result,
both writing tree-log blocks and writing other metadata blocks become
non-sequential writes which ZONED mode must avoid.

This series introduces a dedicated block group for tree-log blocks to
create two metadata writing streams, one for tree-log blocks and the
other for metadata blocks. As a result, each write stream can now be
written to devices separately and sequentially.

* Log-structured superblock

Superblock (and its copies) is the only data structure in btrfs which
has a fixed location on a device. Since we cannot overwrite in a
sequential write required zone, we cannot place superblock in the
zone.

This series implements superblock log writing. It uses two zones as a
circular buffer to write updated superblocks. Once the first zone is filled
up, start writing into the second zone. The first zone will be reset once
both zones are filled. We can determine the postion of the latest
superblock by reading the write pointer information from a device.

* Patch series organization

Patches 1 and 2 are preparing patches for block and iomap layer.

Patch 3 introduces the ZONED incompatible feature flag to indicate that the
btrfs volume was formatted for use on zoned block devices.

Patches 4 to 6 implement functions to gather information on the zones of
the device (zones type, write pointer position, and max_zone_append_size).

Patches 7 to 10 disable features which are not compatible with the
sequential write constraints of zoned block devices. These includes
space_cache, NODATACOW, fallocate, and MIXED_BG.

Patch 11 implements the log-structured superblock writing.

Patches 12 and 13 tweak the device extent allocation for ZONED mode and add
verification to check if a device extent is properly aligned to zones.

Patches 14 to 17 implements sequential block allocator for ZONED mode.

Patch 18 implement a zone reset for unused block groups.

Patches 19 to 30 implement the writing path for several types of IO
(non-compressed data, direct IO, and metadata). These include re-dirtying
once-freed metadata blocks to prevent write holes.

Patches 31 to 40 tweak some btrfs features work with ZONED mode. These
include device-replace, relocation, repairing IO error, and tree-log.

Finally, patch 41 adds the ZONED feature to the list of supported features.

* Patch testing note

** Zone-aware util-linux

Since the log-structured superblock feature changed the location of
superblock magic, the current util-linux (libblkid) cannot detect ZONED
btrfs anymore. You need to apply a to-be posted patch to util-linux to make
it "zone aware".

** Testing device

You need devices with zone append writing command support to run ZONED
btrfs.

Other than real devices, null_blk supports zone append write command. You
can use memory backed null_blk to run the test on it. Following script
creates 12800 MB /dev/nullb0.

    sysfs=/sys/kernel/config/nullb/nullb0
    size=12800 # MB
    
    # drop nullb0
    if [[ -d $sysfs ]]; then
            echo 0 > "${sysfs}"/power
            rmdir $sysfs
    fi
    lsmod | grep -q null_blk && rmmod null_blk
    modprobe null_blk nr_devices=0
    
    mkdir "${sysfs}"
    
    echo "${size}" > "${sysfs}"/size
    echo 1 > "${sysfs}"/zoned
    echo 0 > "${sysfs}"/zone_nr_conv
    echo 1 > "${sysfs}"/memory_backed
    
    echo 1 > "${sysfs}"/power
    udevadm settle

Zoned SCSI devices such as SMR HDDs or scsi_debug also support the zone
append command as an emulated command within the SCSI sd driver. This
emulation is completely transparent to the user and provides the same
semantic as a NVMe ZNS native drive support.

Also, there is a qemu patch available to enable NVMe ZNS device.

** xfstests

We ran xfstests on ZONED btrfs, and, if we omit some cases that are known
to fail currently, all test cases pass.

Cases that can be ignored:
1) failing also with the regular btrfs on regular devices,
2) trying to test fallocate feature without testing with
   "_require_xfs_io_command "falloc"",
3) trying to test incompatible features for ZONED btrfs (e.g. RAID5/6)
4) trying to use incompatible setup for ZONED btrfs (e.g. dm-linear not
   aligned to zone boundary, swap)
5) trying to create a file system with too small size, (we require at least
   9 zones to initiate a ZONED btrfs)
6) dropping original MKFS_OPTIONS ("-O zoned"), so it cannot create ZONED
   btrfs (btrfs/003)
7) having ENOSPC which incurred by larger metadata block group size

I will send a patch series for xfstests to handle these cases (2-6)
properly.

Patched xfstests is available here:

https://github.com/naota/fstests/tree/btrfs-zoned

Also, you need to apply the following patch if you run xfstests with
tcmu devices. xfstests btrfs/003 failed to "_devmgt_add" after
"_devmgt_remove" without this patch.

https://marc.info/?l=linux-scsi&m=156498625421698&w=2

v8 https://lore.kernel.org/linux-btrfs/cover.1601572459.git.naohiro.aota@wdc.com/
v7 https://lore.kernel.org/linux-btrfs/20200911123259.3782926-1-naohiro.aota@wdc.com/
v6 https://lore.kernel.org/linux-btrfs/20191213040915.3502922-1-naohiro.aota@wdc.com/
v5 https://lore.kernel.org/linux-btrfs/20191204082513.857320-1-naohiro.aota@wdc.com/
v4 https://lwn.net/Articles/797061/
v3 https://lore.kernel.org/linux-btrfs/20190808093038.4163421-1-naohiro.aota@wdc.com/
v2 https://lore.kernel.org/linux-btrfs/20190607131025.31996-1-naohiro.aota@wdc.com/
v1 https://lore.kernel.org/linux-btrfs/20180809180450.5091-1-naota@elisp.net/

Changelog
v8
 - Use bio_add_hw_page() to build up bio to honor hardware restrictions
   - add bio_add_zone_append_page() as a wrapper of the function
 - Split file extent on submitting bio
   - If bio_add_zone_append_page() fails, split the file extent and send
     out bio
   - so, we can ensure one bio == one file extent
 - Fix build bot issues
 - Rebased on misc-next
v7:
 - Use zone append write command instead of normal write command
   - Bio issuing order does not matter
   - No need to use lock anymore
   - Can use asynchronous checksum
 - Removed RAID support for now
 - Rename HMZONED to ZONED
 - Split some patches
 - Rebased on kdave/for-5.9-rc3 + iomap direct IO
v6:
 - Use bitmap helpers (Johannes)
 - Code cleanup (Johannes)
 - Rebased on kdave/for-5.5
 - Enable the tree-log feature.
 - Treat conventional zones as sequential zones, so we can now allow
   mixed allocation of conventional zone and sequential write required
   zone to construct a block group.
 - Implement log-structured superblock
   - No need for one conventional zone at the beginning of a device.
 - Fix deadlock of direct IO writing
 - Fix building with !CONFIG_BLK_DEV_ZONED (Johannes)
 - Fix leak of zone_info (Johannes)
v5:
 - Rebased on kdave/for-5.5
 - Enable the tree-log feature.
 - Treat conventional zones as sequential zones, so we can now allow
   mixed allocation of conventional zone and sequential write required
   zone to construct a block group.
 - Implement log-structured superblock
   - No need for one conventional zone at the beginning of a device.
 - Fix deadlock of direct IO writing
 - Fix building with !CONFIG_BLK_DEV_ZONED (Johannes)
 - Fix leak of zone_info (Johannes)
v4:
 - Move memory allcation of zone informattion out of
   btrfs_get_dev_zones() (Anand)
 - Add disabled features table in commit log (Anand)
 - Ensure "max_chunk_size >= devs_min * data_stripes * zone_size"
v3:
 - Serialize allocation and submit_bio instead of bio buffering in
   btrfs_map_bio().
 -- Disable async checksum/submit in HMZONED mode
 - Introduce helper functions and hmzoned.c/h (Josef, David)
 - Add support for repairing IO failure
 - Add support for NOCOW direct IO write (Josef)
 - Disable preallocation entirely
 -- Disable INODE_MAP_CACHE
 -- relocation is reworked not to rely on preallocation in HMZONED mode
 - Disable NODATACOW
 -Disable MIXED_BG
 - Device extent that cover super block position is banned (David)
v2:
 - Add support for dev-replace
 -- To support dev-replace, moved submit_buffer one layer up. It now
    handles bio instead of btrfs_bio.
 -- Mark unmirrored Block Group readonly only when there are writable
    mirrored BGs. Necessary to handle degraded RAID.
 - Expire worker use vanilla delayed_work instead of btrfs's async-thread
 - Device extent allocator now ensure that region is on the same zone type.
 - Add delayed allocation shrinking.
 - Rename btrfs_drop_dev_zonetypes() to btrfs_destroy_dev_zonetypes
 - Fix
 -- Use SECTOR_SHIFT (Nikolay)
 -- Use btrfs_err (Nikolay)

Johannes Thumshirn (1):
  block: add bio_add_zone_append_page

Naohiro Aota (40):
  iomap: support REQ_OP_ZONE_APPEND
  btrfs: introduce ZONED feature flag
  btrfs: Get zone information of zoned block devices
  btrfs: Check and enable ZONED mode
  btrfs: introduce max_zone_append_size
  btrfs: disallow space_cache in ZONED mode
  btrfs: disallow NODATACOW in ZONED mode
  btrfs: disable fallocate in ZONED mode
  btrfs: disallow mixed-bg in ZONED mode
  btrfs: implement log-structured superblock for ZONED mode
  btrfs: implement zoned chunk allocator
  btrfs: verify device extent is aligned to zone
  btrfs: load zone's alloction offset
  btrfs: emulate write pointer for conventional zones
  btrfs: track unusable bytes for zones
  btrfs: do sequential extent allocation in ZONED mode
  btrfs: reset zones of unused block groups
  btrfs: redirty released extent buffers in ZONED mode
  btrfs: extract page adding function
  btrfs: use bio_add_zone_append_page for zoned btrfs
  btrfs: handle REQ_OP_ZONE_APPEND as writing
  btrfs: split ordered extent when bio is sent
  btrfs: extend btrfs_rmap_block for specifying a device
  btrfs: use ZONE_APPEND write for ZONED btrfs
  btrfs: enable zone append writing for direct IO
  btrfs: introduce dedicated data write path for ZONED mode
  btrfs: serialize meta IOs on ZONED mode
  btrfs: wait existing extents before truncating
  btrfs: avoid async metadata checksum on ZONED mode
  btrfs: mark block groups to copy for device-replace
  btrfs: implement cloning for ZONED device-replace
  btrfs: implement copying for ZONED device-replace
  btrfs: support dev-replace in ZONED mode
  btrfs: enable relocation in ZONED mode
  btrfs: relocate block group to repair IO failure in ZONED
  btrfs: split alloc_log_tree()
  btrfs: extend zoned allocator to use dedicated tree-log block group
  btrfs: serialize log transaction on ZONED mode
  btrfs: reorder log node allocation
  btrfs: enable to mount ZONED incompat flag

 block/bio.c                 |   36 +
 fs/btrfs/Makefile           |    1 +
 fs/btrfs/block-group.c      |   90 ++-
 fs/btrfs/block-group.h      |   13 +
 fs/btrfs/ctree.h            |   18 +-
 fs/btrfs/dev-replace.c      |  187 ++++++
 fs/btrfs/dev-replace.h      |    3 +
 fs/btrfs/disk-io.c          |   92 ++-
 fs/btrfs/disk-io.h          |    2 +
 fs/btrfs/extent-tree.c      |  206 +++++-
 fs/btrfs/extent_io.c        |  136 +++-
 fs/btrfs/extent_io.h        |    2 +
 fs/btrfs/file.c             |    6 +-
 fs/btrfs/free-space-cache.c |   58 ++
 fs/btrfs/free-space-cache.h |    4 +
 fs/btrfs/inode.c            |  164 ++++-
 fs/btrfs/ioctl.c            |   16 +
 fs/btrfs/ordered-data.c     |   79 +++
 fs/btrfs/ordered-data.h     |   10 +
 fs/btrfs/relocation.c       |   35 +-
 fs/btrfs/scrub.c            |  145 ++++
 fs/btrfs/space-info.c       |   13 +-
 fs/btrfs/space-info.h       |    4 +-
 fs/btrfs/super.c            |   18 +-
 fs/btrfs/sysfs.c            |    4 +
 fs/btrfs/transaction.c      |   10 +
 fs/btrfs/transaction.h      |    3 +
 fs/btrfs/tree-log.c         |   52 +-
 fs/btrfs/volumes.c          |  311 ++++++++-
 fs/btrfs/volumes.h          |    7 +
 fs/btrfs/zoned.c            | 1264 +++++++++++++++++++++++++++++++++++
 fs/btrfs/zoned.h            |  273 ++++++++
 fs/iomap/direct-io.c        |   22 +-
 include/linux/bio.h         |    2 +
 include/linux/iomap.h       |    1 +
 include/uapi/linux/btrfs.h  |    1 +
 36 files changed, 3176 insertions(+), 112 deletions(-)
 create mode 100644 fs/btrfs/zoned.c
 create mode 100644 fs/btrfs/zoned.h

-- 
2.27.0


^ permalink raw reply	[flat|nested] 119+ messages in thread

* [PATCH v9 01/41] block: add bio_add_zone_append_page
  2020-10-30 13:51 [PATCH v9 00/41] btrfs: zoned block device support Naohiro Aota
@ 2020-10-30 13:51 ` Naohiro Aota
  2020-10-30 13:51   ` [PATCH v9 02/41] iomap: support REQ_OP_ZONE_APPEND Naohiro Aota
                     ` (40 more replies)
  2020-11-03 11:54 ` [PATCH v9 00/41] btrfs: zoned block device support David Sterba
  1 sibling, 41 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Johannes Thumshirn, Jens Axboe

From: Johannes Thumshirn <johannes.thumshirn@wdc.com>

Add bio_add_zone_append_page(), a wrapper around bio_add_hw_page() which
is intended to be used by file systems that directly add pages to a bio
instead of using bio_iov_iter_get_pages().

Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
---
 block/bio.c         | 36 ++++++++++++++++++++++++++++++++++++
 include/linux/bio.h |  2 ++
 2 files changed, 38 insertions(+)

diff --git a/block/bio.c b/block/bio.c
index 58d765400226..2dfe40be4d6b 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -853,6 +853,42 @@ int bio_add_pc_page(struct request_queue *q, struct bio *bio,
 }
 EXPORT_SYMBOL(bio_add_pc_page);
 
+/**
+ * bio_add_zone_append_page - attempt to add page to zone-append bio
+ * @bio: destination bio
+ * @page: page to add
+ * @len: vec entry length
+ * @offset: vec entry offset
+ *
+ * Attempt to add a page to the bio_vec maplist of a bio that will be submitted
+ * for a zone-append request. This can fail for a number of reasons, such as the
+ * bio being full or the target block device is not a zoned block device or
+ * other limitations of the target block device. The target block device must
+ * allow bio's up to PAGE_SIZE, so it is always possible to add a single page
+ * to an empty bio.
+ */
+int bio_add_zone_append_page(struct bio *bio, struct page *page,
+			     unsigned int len, unsigned int offset)
+{
+	struct request_queue *q;
+	bool same_page = false;
+
+	if (WARN_ON_ONCE(bio_op(bio) != REQ_OP_ZONE_APPEND))
+		return 0;
+
+	if (WARN_ON_ONCE(!bio->bi_disk))
+		return 0;
+
+	q = bio->bi_disk->queue;
+
+	if (WARN_ON_ONCE(!blk_queue_is_zoned(q)))
+		return 0;
+
+	return bio_add_hw_page(q, bio, page, len, offset,
+			       queue_max_zone_append_sectors(q), &same_page);
+}
+EXPORT_SYMBOL_GPL(bio_add_zone_append_page);
+
 /**
  * __bio_try_merge_page - try appending data to an existing bvec.
  * @bio: destination bio
diff --git a/include/linux/bio.h b/include/linux/bio.h
index c6d765382926..7ef300cb4e9a 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -442,6 +442,8 @@ void bio_chain(struct bio *, struct bio *);
 extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
 extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
 			   unsigned int, unsigned int);
+int bio_add_zone_append_page(struct bio *bio, struct page *page,
+			     unsigned int len, unsigned int offset);
 bool __bio_try_merge_page(struct bio *bio, struct page *page,
 		unsigned int len, unsigned int off, bool *same_page);
 void __bio_add_page(struct bio *bio, struct page *page,
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 02/41] iomap: support REQ_OP_ZONE_APPEND
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-02  5:34     ` Naohiro Aota
  2020-11-02 16:55     ` Darrick J. Wong
  2020-10-30 13:51   ` [PATCH v9 03/41] btrfs: introduce ZONED feature flag Naohiro Aota
                     ` (39 subsequent siblings)
  40 siblings, 2 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba
  Cc: hare, linux-fsdevel, Naohiro Aota, Christoph Hellwig,
	Darrick J. Wong, linux-xfs

A ZONE_APPEND bio must follow hardware restrictions (e.g. not exceeding
max_zone_append_sectors) not to be split. bio_iov_iter_get_pages builds
such restricted bio using __bio_iov_append_get_pages if bio_op(bio) ==
REQ_OP_ZONE_APPEND.

To utilize it, we need to set the bio_op before calling
bio_iov_iter_get_pages(). This commit introduces IOMAP_F_ZONE_APPEND, so
that iomap user can set the flag to indicate they want REQ_OP_ZONE_APPEND
and restricted bio.

Cc: Christoph Hellwig <hch@infradead.org>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: linux-xfs@vger.kernel.org
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/iomap/direct-io.c  | 22 ++++++++++++++++------
 include/linux/iomap.h |  1 +
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index c1aafb2ab990..e534703c5594 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -210,6 +210,7 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,
 	struct bio *bio;
 	bool need_zeroout = false;
 	bool use_fua = false;
+	bool zone_append = false;
 	int nr_pages, ret = 0;
 	size_t copied = 0;
 	size_t orig_count;
@@ -241,6 +242,8 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,
 			use_fua = true;
 	}
 
+	zone_append = iomap->flags & IOMAP_F_ZONE_APPEND;
+
 	/*
 	 * Save the original count and trim the iter to just the extent we
 	 * are operating on right now.  The iter will be re-expanded once
@@ -278,6 +281,19 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,
 		bio->bi_private = dio;
 		bio->bi_end_io = iomap_dio_bio_end_io;
 
+		if (dio->flags & IOMAP_DIO_WRITE) {
+			bio->bi_opf = (zone_append ? REQ_OP_ZONE_APPEND : REQ_OP_WRITE) |
+				      REQ_SYNC | REQ_IDLE;
+			if (use_fua)
+				bio->bi_opf |= REQ_FUA;
+			else
+				dio->flags &= ~IOMAP_DIO_WRITE_FUA;
+		} else {
+			WARN_ON_ONCE(zone_append);
+
+			bio->bi_opf = REQ_OP_READ;
+		}
+
 		ret = bio_iov_iter_get_pages(bio, dio->submit.iter);
 		if (unlikely(ret)) {
 			/*
@@ -292,14 +308,8 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,
 
 		n = bio->bi_iter.bi_size;
 		if (dio->flags & IOMAP_DIO_WRITE) {
-			bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_IDLE;
-			if (use_fua)
-				bio->bi_opf |= REQ_FUA;
-			else
-				dio->flags &= ~IOMAP_DIO_WRITE_FUA;
 			task_io_account_write(n);
 		} else {
-			bio->bi_opf = REQ_OP_READ;
 			if (dio->flags & IOMAP_DIO_DIRTY)
 				bio_set_pages_dirty(bio);
 		}
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 4d1d3c3469e9..1bccd1880d0d 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -54,6 +54,7 @@ struct vm_fault;
 #define IOMAP_F_SHARED		0x04
 #define IOMAP_F_MERGED		0x08
 #define IOMAP_F_BUFFER_HEAD	0x10
+#define IOMAP_F_ZONE_APPEND	0x20
 
 /*
  * Flags set by the core iomap code during operations:
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 03/41] btrfs: introduce ZONED feature flag
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
  2020-10-30 13:51   ` [PATCH v9 02/41] iomap: support REQ_OP_ZONE_APPEND Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-10-30 13:51   ` [PATCH v9 04/41] btrfs: Get zone information of zoned block devices Naohiro Aota
                     ` (38 subsequent siblings)
  40 siblings, 0 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba
  Cc: hare, linux-fsdevel, Naohiro Aota, Damien Le Moal, Anand Jain,
	Johannes Thumshirn

This patch introduces the ZONED incompat flag. The flag indicates that the
volume management will satisfy the constraints imposed by host-managed
zoned block devices.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
---
 fs/btrfs/sysfs.c           | 2 ++
 include/uapi/linux/btrfs.h | 1 +
 2 files changed, 3 insertions(+)

diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 279d9262b676..828006020bbd 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -263,6 +263,7 @@ BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
 BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
 BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
 BTRFS_FEAT_ATTR_INCOMPAT(raid1c34, RAID1C34);
+BTRFS_FEAT_ATTR_INCOMPAT(zoned, ZONED);
 
 static struct attribute *btrfs_supported_feature_attrs[] = {
 	BTRFS_FEAT_ATTR_PTR(mixed_backref),
@@ -278,6 +279,7 @@ static struct attribute *btrfs_supported_feature_attrs[] = {
 	BTRFS_FEAT_ATTR_PTR(metadata_uuid),
 	BTRFS_FEAT_ATTR_PTR(free_space_tree),
 	BTRFS_FEAT_ATTR_PTR(raid1c34),
+	BTRFS_FEAT_ATTR_PTR(zoned),
 	NULL
 };
 
diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
index 2c39d15a2beb..5df73001aad4 100644
--- a/include/uapi/linux/btrfs.h
+++ b/include/uapi/linux/btrfs.h
@@ -307,6 +307,7 @@ struct btrfs_ioctl_fs_info_args {
 #define BTRFS_FEATURE_INCOMPAT_NO_HOLES		(1ULL << 9)
 #define BTRFS_FEATURE_INCOMPAT_METADATA_UUID	(1ULL << 10)
 #define BTRFS_FEATURE_INCOMPAT_RAID1C34		(1ULL << 11)
+#define BTRFS_FEATURE_INCOMPAT_ZONED		(1ULL << 12)
 
 struct btrfs_ioctl_feature_flags {
 	__u64 compat_flags;
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 04/41] btrfs: Get zone information of zoned block devices
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
  2020-10-30 13:51   ` [PATCH v9 02/41] iomap: support REQ_OP_ZONE_APPEND Naohiro Aota
  2020-10-30 13:51   ` [PATCH v9 03/41] btrfs: introduce ZONED feature flag Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-02 16:53     ` Josef Bacik
  2020-11-03 12:02     ` David Sterba
  2020-10-30 13:51   ` [PATCH v9 05/41] btrfs: Check and enable ZONED mode Naohiro Aota
                     ` (37 subsequent siblings)
  40 siblings, 2 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba
  Cc: hare, linux-fsdevel, Naohiro Aota, Damien Le Moal, Josef Bacik

If a zoned block device is found, get its zone information (number of zones
and zone size) using the new helper function btrfs_get_dev_zone_info().  To
avoid costly run-time zone report commands to test the device zones type
during block allocation, attach the seq_zones bitmap to the device
structure to indicate if a zone is sequential or accept random writes. Also
it attaches the empty_zones bitmap to indicate if a zone is empty or not.

This patch also introduces the helper function btrfs_dev_is_sequential() to
test if the zone storing a block is a sequential write required zone and
btrfs_dev_is_empty_zone() to test if the zone is a empty zone.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/Makefile      |   1 +
 fs/btrfs/dev-replace.c |   5 ++
 fs/btrfs/super.c       |   5 ++
 fs/btrfs/volumes.c     |  19 ++++-
 fs/btrfs/volumes.h     |   4 +
 fs/btrfs/zoned.c       | 176 +++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/zoned.h       |  86 ++++++++++++++++++++
 7 files changed, 294 insertions(+), 2 deletions(-)
 create mode 100644 fs/btrfs/zoned.c
 create mode 100644 fs/btrfs/zoned.h

diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
index e738f6206ea5..0497fdc37f90 100644
--- a/fs/btrfs/Makefile
+++ b/fs/btrfs/Makefile
@@ -16,6 +16,7 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
 btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o
 btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o
 btrfs-$(CONFIG_BTRFS_FS_REF_VERIFY) += ref-verify.o
+btrfs-$(CONFIG_BLK_DEV_ZONED) += zoned.o
 
 btrfs-$(CONFIG_BTRFS_FS_RUN_SANITY_TESTS) += tests/free-space-tests.o \
 	tests/extent-buffer-tests.o tests/btrfs-tests.o \
diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index 20ce1970015f..6f6d77224c2b 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -21,6 +21,7 @@
 #include "rcu-string.h"
 #include "dev-replace.h"
 #include "sysfs.h"
+#include "zoned.h"
 
 /*
  * Device replace overview
@@ -291,6 +292,10 @@ static int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 	set_blocksize(device->bdev, BTRFS_BDEV_BLOCKSIZE);
 	device->fs_devices = fs_info->fs_devices;
 
+	ret = btrfs_get_dev_zone_info(device);
+	if (ret)
+		goto error;
+
 	mutex_lock(&fs_info->fs_devices->device_list_mutex);
 	list_add(&device->dev_list, &fs_info->fs_devices->devices);
 	fs_info->fs_devices->num_devices++;
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 8840a4fa81eb..ed55014fd1bd 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -2462,6 +2462,11 @@ static void __init btrfs_print_mod_info(void)
 #endif
 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
 			", ref-verify=on"
+#endif
+#ifdef CONFIG_BLK_DEV_ZONED
+			", zoned=yes"
+#else
+			", zoned=no"
 #endif
 			;
 	pr_info("Btrfs loaded, crc32c=%s%s\n", crc32c_impl(), options);
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 58b9c419a2b6..e787bf89f761 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -31,6 +31,7 @@
 #include "space-info.h"
 #include "block-group.h"
 #include "discard.h"
+#include "zoned.h"
 
 const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 	[BTRFS_RAID_RAID10] = {
@@ -374,6 +375,7 @@ void btrfs_free_device(struct btrfs_device *device)
 	rcu_string_free(device->name);
 	extent_io_tree_release(&device->alloc_state);
 	bio_put(device->flush_bio);
+	btrfs_destroy_dev_zone_info(device);
 	kfree(device);
 }
 
@@ -667,6 +669,11 @@ static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices,
 	clear_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
 	device->mode = flags;
 
+	/* Get zone type information of zoned block devices */
+	ret = btrfs_get_dev_zone_info(device);
+	if (ret != 0)
+		goto error_free_page;
+
 	fs_devices->open_devices++;
 	if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) &&
 	    device->devid != BTRFS_DEV_REPLACE_DEVID) {
@@ -1143,6 +1150,7 @@ static void btrfs_close_one_device(struct btrfs_device *device)
 		device->bdev = NULL;
 	}
 	clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
+	btrfs_destroy_dev_zone_info(device);
 
 	device->fs_info = NULL;
 	atomic_set(&device->dev_stats_ccnt, 0);
@@ -2543,6 +2551,14 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
 	}
 	rcu_assign_pointer(device->name, name);
 
+	device->fs_info = fs_info;
+	device->bdev = bdev;
+
+	/* Get zone type information of zoned block devices */
+	ret = btrfs_get_dev_zone_info(device);
+	if (ret)
+		goto error_free_device;
+
 	trans = btrfs_start_transaction(root, 0);
 	if (IS_ERR(trans)) {
 		ret = PTR_ERR(trans);
@@ -2559,8 +2575,6 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
 					 fs_info->sectorsize);
 	device->disk_total_bytes = device->total_bytes;
 	device->commit_total_bytes = device->total_bytes;
-	device->fs_info = fs_info;
-	device->bdev = bdev;
 	set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
 	clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
 	device->mode = FMODE_EXCL;
@@ -2707,6 +2721,7 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
 		sb->s_flags |= SB_RDONLY;
 	if (trans)
 		btrfs_end_transaction(trans);
+	btrfs_destroy_dev_zone_info(device);
 error_free_device:
 	btrfs_free_device(device);
 error:
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index bf27ac07d315..9c07b97a2260 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -51,6 +51,8 @@ struct btrfs_io_geometry {
 #define BTRFS_DEV_STATE_REPLACE_TGT	(3)
 #define BTRFS_DEV_STATE_FLUSH_SENT	(4)
 
+struct btrfs_zoned_device_info;
+
 struct btrfs_device {
 	struct list_head dev_list; /* device_list_mutex */
 	struct list_head dev_alloc_list; /* chunk mutex */
@@ -64,6 +66,8 @@ struct btrfs_device {
 
 	struct block_device *bdev;
 
+	struct btrfs_zoned_device_info *zone_info;
+
 	/* the mode sent to blkdev_get */
 	fmode_t mode;
 
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
new file mode 100644
index 000000000000..5657d654bc44
--- /dev/null
+++ b/fs/btrfs/zoned.c
@@ -0,0 +1,176 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/slab.h>
+#include <linux/blkdev.h>
+#include "ctree.h"
+#include "volumes.h"
+#include "zoned.h"
+#include "rcu-string.h"
+
+/* Maximum number of zones to report per blkdev_report_zones() call */
+#define BTRFS_REPORT_NR_ZONES   4096
+
+static int copy_zone_info_cb(struct blk_zone *zone, unsigned int idx,
+			     void *data)
+{
+	struct blk_zone *zones = data;
+
+	memcpy(&zones[idx], zone, sizeof(*zone));
+
+	return 0;
+}
+
+static int btrfs_get_dev_zones(struct btrfs_device *device, u64 pos,
+			       struct blk_zone *zones, unsigned int *nr_zones)
+{
+	int ret;
+
+	if (!*nr_zones)
+		return 0;
+
+	ret = blkdev_report_zones(device->bdev, pos >> SECTOR_SHIFT, *nr_zones,
+				  copy_zone_info_cb, zones);
+	if (ret < 0) {
+		btrfs_err_in_rcu(device->fs_info,
+				 "get zone at %llu on %s failed %d", pos,
+				 rcu_str_deref(device->name), ret);
+		return ret;
+	}
+	*nr_zones = ret;
+	if (!ret)
+		return -EIO;
+
+	return 0;
+}
+
+int btrfs_get_dev_zone_info(struct btrfs_device *device)
+{
+	struct btrfs_zoned_device_info *zone_info = NULL;
+	struct block_device *bdev = device->bdev;
+	sector_t nr_sectors = bdev->bd_part->nr_sects;
+	sector_t sector = 0;
+	struct blk_zone *zones = NULL;
+	unsigned int i, nreported = 0, nr_zones;
+	unsigned int zone_sectors;
+	int ret;
+	char devstr[sizeof(device->fs_info->sb->s_id) +
+		    sizeof(" (device )") - 1];
+
+	if (!bdev_is_zoned(bdev))
+		return 0;
+
+	if (device->zone_info)
+		return 0;
+
+	zone_info = kzalloc(sizeof(*zone_info), GFP_KERNEL);
+	if (!zone_info)
+		return -ENOMEM;
+
+	zone_sectors = bdev_zone_sectors(bdev);
+	ASSERT(is_power_of_2(zone_sectors));
+	zone_info->zone_size = (u64)zone_sectors << SECTOR_SHIFT;
+	zone_info->zone_size_shift = ilog2(zone_info->zone_size);
+	zone_info->nr_zones = nr_sectors >> ilog2(bdev_zone_sectors(bdev));
+	if (!IS_ALIGNED(nr_sectors, zone_sectors))
+		zone_info->nr_zones++;
+
+	zone_info->seq_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
+	if (!zone_info->seq_zones) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	zone_info->empty_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
+	if (!zone_info->empty_zones) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	zones = kcalloc(BTRFS_REPORT_NR_ZONES,
+			sizeof(struct blk_zone), GFP_KERNEL);
+	if (!zones) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	/* Get zones type */
+	while (sector < nr_sectors) {
+		nr_zones = BTRFS_REPORT_NR_ZONES;
+		ret = btrfs_get_dev_zones(device, sector << SECTOR_SHIFT, zones,
+					  &nr_zones);
+		if (ret)
+			goto out;
+
+		for (i = 0; i < nr_zones; i++) {
+			if (zones[i].type == BLK_ZONE_TYPE_SEQWRITE_REQ)
+				set_bit(nreported, zone_info->seq_zones);
+			if (zones[i].cond == BLK_ZONE_COND_EMPTY)
+				set_bit(nreported, zone_info->empty_zones);
+			nreported++;
+		}
+		sector = zones[nr_zones - 1].start + zones[nr_zones - 1].len;
+	}
+
+	if (nreported != zone_info->nr_zones) {
+		btrfs_err_in_rcu(device->fs_info,
+				 "inconsistent number of zones on %s (%u / %u)",
+				 rcu_str_deref(device->name), nreported,
+				 zone_info->nr_zones);
+		ret = -EIO;
+		goto out;
+	}
+
+	kfree(zones);
+
+	device->zone_info = zone_info;
+
+	devstr[0] = 0;
+	if (device->fs_info)
+		snprintf(devstr, sizeof(devstr), " (device %s)",
+			 device->fs_info->sb->s_id);
+
+	rcu_read_lock();
+	pr_info(
+"BTRFS info%s: host-%s zoned block device %s, %u zones of %llu sectors",
+		devstr,
+		bdev_zoned_model(bdev) == BLK_ZONED_HM ? "managed" : "aware",
+		rcu_str_deref(device->name), zone_info->nr_zones,
+		zone_info->zone_size >> SECTOR_SHIFT);
+	rcu_read_unlock();
+
+	return 0;
+
+out:
+	kfree(zones);
+	bitmap_free(zone_info->empty_zones);
+	bitmap_free(zone_info->seq_zones);
+	kfree(zone_info);
+
+	return ret;
+}
+
+void btrfs_destroy_dev_zone_info(struct btrfs_device *device)
+{
+	struct btrfs_zoned_device_info *zone_info = device->zone_info;
+
+	if (!zone_info)
+		return;
+
+	bitmap_free(zone_info->seq_zones);
+	bitmap_free(zone_info->empty_zones);
+	kfree(zone_info);
+	device->zone_info = NULL;
+}
+
+int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
+		       struct blk_zone *zone)
+{
+	unsigned int nr_zones = 1;
+	int ret;
+
+	ret = btrfs_get_dev_zones(device, pos, zone, &nr_zones);
+	if (ret != 0 || !nr_zones)
+		return ret ? ret : -EIO;
+
+	return 0;
+}
diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h
new file mode 100644
index 000000000000..483229e27908
--- /dev/null
+++ b/fs/btrfs/zoned.h
@@ -0,0 +1,86 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef BTRFS_ZONED_H
+#define BTRFS_ZONED_H
+
+struct btrfs_zoned_device_info {
+	/*
+	 * Number of zones, zone size and types of zones if bdev is a
+	 * zoned block device.
+	 */
+	u64 zone_size;
+	u8  zone_size_shift;
+	u32 nr_zones;
+	unsigned long *seq_zones;
+	unsigned long *empty_zones;
+};
+
+#ifdef CONFIG_BLK_DEV_ZONED
+int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
+		       struct blk_zone *zone);
+int btrfs_get_dev_zone_info(struct btrfs_device *device);
+void btrfs_destroy_dev_zone_info(struct btrfs_device *device);
+#else /* CONFIG_BLK_DEV_ZONED */
+static inline int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
+				     struct blk_zone *zone)
+{
+	return 0;
+}
+static inline int btrfs_get_dev_zone_info(struct btrfs_device *device)
+{
+	return 0;
+}
+static inline void btrfs_destroy_dev_zone_info(struct btrfs_device *device) { }
+#endif
+
+static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos)
+{
+	struct btrfs_zoned_device_info *zone_info = device->zone_info;
+
+	if (!zone_info)
+		return false;
+
+	return test_bit(pos >> zone_info->zone_size_shift,
+			zone_info->seq_zones);
+}
+
+static inline bool btrfs_dev_is_empty_zone(struct btrfs_device *device, u64 pos)
+{
+	struct btrfs_zoned_device_info *zone_info = device->zone_info;
+
+	if (!zone_info)
+		return true;
+
+	return test_bit(pos >> zone_info->zone_size_shift,
+			zone_info->empty_zones);
+}
+
+static inline void btrfs_dev_set_empty_zone_bit(struct btrfs_device *device,
+						u64 pos, bool set)
+{
+	struct btrfs_zoned_device_info *zone_info = device->zone_info;
+	unsigned int zno;
+
+	if (!zone_info)
+		return;
+
+	zno = pos >> zone_info->zone_size_shift;
+	if (set)
+		set_bit(zno, zone_info->empty_zones);
+	else
+		clear_bit(zno, zone_info->empty_zones);
+}
+
+static inline void btrfs_dev_set_zone_empty(struct btrfs_device *device,
+					    u64 pos)
+{
+	btrfs_dev_set_empty_zone_bit(device, pos, true);
+}
+
+static inline void btrfs_dev_clear_zone_empty(struct btrfs_device *device,
+					      u64 pos)
+{
+	btrfs_dev_set_empty_zone_bit(device, pos, false);
+}
+
+#endif
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 05/41] btrfs: Check and enable ZONED mode
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (2 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 04/41] btrfs: Get zone information of zoned block devices Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 12:13     ` David Sterba
  2020-10-30 13:51   ` [PATCH v9 06/41] btrfs: introduce max_zone_append_size Naohiro Aota
                     ` (36 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba
  Cc: hare, linux-fsdevel, Naohiro Aota, Johannes Thumshirn,
	Damien Le Moal, Josef Bacik

This commit introduces the function btrfs_check_zoned_mode() to check if
ZONED flag is enabled on the file system and if the file system consists of
zoned devices with equal zone size.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/ctree.h       | 10 ++++++
 fs/btrfs/dev-replace.c |  7 ++++
 fs/btrfs/disk-io.c     | 11 ++++++
 fs/btrfs/super.c       |  1 +
 fs/btrfs/volumes.c     |  5 +++
 fs/btrfs/zoned.c       | 78 ++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/zoned.h       | 26 ++++++++++++++
 7 files changed, 138 insertions(+)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index aac3d6f4e35b..25fd4e97dd2a 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -948,6 +948,12 @@ struct btrfs_fs_info {
 	/* Type of exclusive operation running */
 	unsigned long exclusive_operation;
 
+	/* Zone size when in ZONED mode */
+	union {
+		u64 zone_size;
+		u64 zoned;
+	};
+
 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
 	spinlock_t ref_verify_lock;
 	struct rb_root block_tree;
@@ -3595,4 +3601,8 @@ static inline int btrfs_is_testing(struct btrfs_fs_info *fs_info)
 }
 #endif
 
+static inline bool btrfs_is_zoned(struct btrfs_fs_info *fs_info)
+{
+	return fs_info->zoned != 0;
+}
 #endif
diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index 6f6d77224c2b..5e3554482af1 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -238,6 +238,13 @@ static int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 		return PTR_ERR(bdev);
 	}
 
+	if (!btrfs_check_device_zone_type(fs_info, bdev)) {
+		btrfs_err(fs_info,
+			  "zone type of target device mismatch with the filesystem!");
+		ret = -EINVAL;
+		goto error;
+	}
+
 	sync_blockdev(bdev);
 
 	list_for_each_entry(device, &fs_info->fs_devices->devices, dev_list) {
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 764001609a15..9bc51cff48b8 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -42,6 +42,7 @@
 #include "block-group.h"
 #include "discard.h"
 #include "space-info.h"
+#include "zoned.h"
 
 #define BTRFS_SUPER_FLAG_SUPP	(BTRFS_HEADER_FLAG_WRITTEN |\
 				 BTRFS_HEADER_FLAG_RELOC |\
@@ -2976,6 +2977,8 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
 	if (features & BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA)
 		btrfs_info(fs_info, "has skinny extents");
 
+	fs_info->zoned = features & BTRFS_FEATURE_INCOMPAT_ZONED;
+
 	/*
 	 * flag our filesystem as having big metadata blocks if
 	 * they are bigger than the page size
@@ -3130,7 +3133,15 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
 
 	btrfs_free_extra_devids(fs_devices, 1);
 
+	ret = btrfs_check_zoned_mode(fs_info);
+	if (ret) {
+		btrfs_err(fs_info, "failed to init ZONED mode: %d",
+				ret);
+		goto fail_block_groups;
+	}
+
 	ret = btrfs_sysfs_add_fsid(fs_devices);
+
 	if (ret) {
 		btrfs_err(fs_info, "failed to init sysfs fsid interface: %d",
 				ret);
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index ed55014fd1bd..3312fe08168f 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -44,6 +44,7 @@
 #include "backref.h"
 #include "space-info.h"
 #include "sysfs.h"
+#include "zoned.h"
 #include "tests/btrfs-tests.h"
 #include "block-group.h"
 #include "discard.h"
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index e787bf89f761..10827892c086 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2518,6 +2518,11 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
 	if (IS_ERR(bdev))
 		return PTR_ERR(bdev);
 
+	if (!btrfs_check_device_zone_type(fs_info, bdev)) {
+		ret = -EINVAL;
+		goto error;
+	}
+
 	if (fs_devices->seeding) {
 		seeding_dev = 1;
 		down_write(&sb->s_umount);
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index 5657d654bc44..e1cdff5af3a3 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -174,3 +174,81 @@ int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
 
 	return 0;
 }
+
+int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
+{
+	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
+	struct btrfs_device *device;
+	u64 hmzoned_devices = 0;
+	u64 nr_devices = 0;
+	u64 zone_size = 0;
+	int incompat_zoned = btrfs_is_zoned(fs_info);
+	int ret = 0;
+
+	/* Count zoned devices */
+	list_for_each_entry(device, &fs_devices->devices, dev_list) {
+		enum blk_zoned_model model;
+
+		if (!device->bdev)
+			continue;
+
+		model = bdev_zoned_model(device->bdev);
+		if (model == BLK_ZONED_HM ||
+		    (model == BLK_ZONED_HA && incompat_zoned)) {
+			hmzoned_devices++;
+			if (!zone_size) {
+				zone_size = device->zone_info->zone_size;
+			} else if (device->zone_info->zone_size != zone_size) {
+				btrfs_err(fs_info,
+					  "Zoned block devices must have equal zone sizes");
+				ret = -EINVAL;
+				goto out;
+			}
+		}
+		nr_devices++;
+	}
+
+	if (!hmzoned_devices && !incompat_zoned)
+		goto out;
+
+	if (!hmzoned_devices && incompat_zoned) {
+		/* No zoned block device found on ZONED FS */
+		btrfs_err(fs_info,
+			  "ZONED enabled file system should have zoned devices");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (hmzoned_devices && !incompat_zoned) {
+		btrfs_err(fs_info,
+			  "Enable ZONED mode to mount HMZONED device");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (hmzoned_devices != nr_devices) {
+		btrfs_err(fs_info,
+			  "zoned devices cannot be mixed with regular devices");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/*
+	 * stripe_size is always aligned to BTRFS_STRIPE_LEN in
+	 * __btrfs_alloc_chunk(). Since we want stripe_len == zone_size,
+	 * check the alignment here.
+	 */
+	if (!IS_ALIGNED(zone_size, BTRFS_STRIPE_LEN)) {
+		btrfs_err(fs_info,
+			  "zone size is not aligned to BTRFS_STRIPE_LEN");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	fs_info->zone_size = zone_size;
+
+	btrfs_info(fs_info, "ZONED mode enabled, zone size %llu B",
+		   fs_info->zone_size);
+out:
+	return ret;
+}
diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h
index 483229e27908..c4c63c4294f2 100644
--- a/fs/btrfs/zoned.h
+++ b/fs/btrfs/zoned.h
@@ -3,6 +3,8 @@
 #ifndef BTRFS_ZONED_H
 #define BTRFS_ZONED_H
 
+#include <linux/blkdev.h>
+
 struct btrfs_zoned_device_info {
 	/*
 	 * Number of zones, zone size and types of zones if bdev is a
@@ -20,6 +22,7 @@ int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
 		       struct blk_zone *zone);
 int btrfs_get_dev_zone_info(struct btrfs_device *device);
 void btrfs_destroy_dev_zone_info(struct btrfs_device *device);
+int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info);
 #else /* CONFIG_BLK_DEV_ZONED */
 static inline int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
 				     struct blk_zone *zone)
@@ -31,6 +34,14 @@ static inline int btrfs_get_dev_zone_info(struct btrfs_device *device)
 	return 0;
 }
 static inline void btrfs_destroy_dev_zone_info(struct btrfs_device *device) { }
+static inline int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
+{
+	if (!btrfs_is_zoned(fs_info))
+		return 0;
+
+	btrfs_err(fs_info, "Zoned block devices support is not enabled");
+	return -EOPNOTSUPP;
+}
 #endif
 
 static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos)
@@ -83,4 +94,19 @@ static inline void btrfs_dev_clear_zone_empty(struct btrfs_device *device,
 	btrfs_dev_set_empty_zone_bit(device, pos, false);
 }
 
+static inline bool btrfs_check_device_zone_type(struct btrfs_fs_info *fs_info,
+						struct block_device *bdev)
+{
+	u64 zone_size;
+
+	if (btrfs_is_zoned(fs_info)) {
+		zone_size = (u64)bdev_zone_sectors(bdev) << SECTOR_SHIFT;
+		/* Do not allow non-zoned device */
+		return bdev_is_zoned(bdev) && fs_info->zone_size == zone_size;
+	}
+
+	/* Do not allow Host Manged zoned device */
+	return bdev_zoned_model(bdev) != BLK_ZONED_HM;
+}
+
 #endif
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 06/41] btrfs: introduce max_zone_append_size
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (3 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 05/41] btrfs: Check and enable ZONED mode Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-02 16:57     ` Josef Bacik
  2020-11-03 12:16     ` David Sterba
  2020-10-30 13:51   ` [PATCH v9 07/41] btrfs: disallow space_cache in ZONED mode Naohiro Aota
                     ` (35 subsequent siblings)
  40 siblings, 2 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

The zone append write command has a maximum IO size restriction it
accepts. This is because a zone append write command cannot be split, as
we ask the device to place the data into a specific target zone and the
device responds with the actual written location of the data.

Introduce max_zone_append_size to zone_info and fs_info to track the
value, so we can limit all I/O to a zoned block device that we want to
write using the zone append command to the device's limits.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/ctree.h |  2 ++
 fs/btrfs/zoned.c | 19 ++++++++++++++++---
 fs/btrfs/zoned.h |  1 +
 3 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 25fd4e97dd2a..383c83a1f5b5 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -953,6 +953,8 @@ struct btrfs_fs_info {
 		u64 zone_size;
 		u64 zoned;
 	};
+	/* max size to emit ZONE_APPEND write command */
+	u64 max_zone_append_size;
 
 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
 	spinlock_t ref_verify_lock;
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index e1cdff5af3a3..1b42e13b8227 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -47,6 +47,7 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device)
 {
 	struct btrfs_zoned_device_info *zone_info = NULL;
 	struct block_device *bdev = device->bdev;
+	struct request_queue *q = bdev_get_queue(bdev);
 	sector_t nr_sectors = bdev->bd_part->nr_sects;
 	sector_t sector = 0;
 	struct blk_zone *zones = NULL;
@@ -70,6 +71,8 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device)
 	ASSERT(is_power_of_2(zone_sectors));
 	zone_info->zone_size = (u64)zone_sectors << SECTOR_SHIFT;
 	zone_info->zone_size_shift = ilog2(zone_info->zone_size);
+	zone_info->max_zone_append_size =
+		(u64)queue_max_zone_append_sectors(q) << SECTOR_SHIFT;
 	zone_info->nr_zones = nr_sectors >> ilog2(bdev_zone_sectors(bdev));
 	if (!IS_ALIGNED(nr_sectors, zone_sectors))
 		zone_info->nr_zones++;
@@ -182,7 +185,8 @@ int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
 	u64 hmzoned_devices = 0;
 	u64 nr_devices = 0;
 	u64 zone_size = 0;
-	int incompat_zoned = btrfs_is_zoned(fs_info);
+	u64 max_zone_append_size = 0;
+	bool incompat_zoned = btrfs_is_zoned(fs_info);
 	int ret = 0;
 
 	/* Count zoned devices */
@@ -195,15 +199,23 @@ int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
 		model = bdev_zoned_model(device->bdev);
 		if (model == BLK_ZONED_HM ||
 		    (model == BLK_ZONED_HA && incompat_zoned)) {
+			struct btrfs_zoned_device_info *zone_info =
+				device->zone_info;
+
 			hmzoned_devices++;
 			if (!zone_size) {
-				zone_size = device->zone_info->zone_size;
-			} else if (device->zone_info->zone_size != zone_size) {
+				zone_size = zone_info->zone_size;
+			} else if (zone_info->zone_size != zone_size) {
 				btrfs_err(fs_info,
 					  "Zoned block devices must have equal zone sizes");
 				ret = -EINVAL;
 				goto out;
 			}
+			if (!max_zone_append_size ||
+			    (zone_info->max_zone_append_size &&
+			     zone_info->max_zone_append_size < max_zone_append_size))
+				max_zone_append_size =
+					zone_info->max_zone_append_size;
 		}
 		nr_devices++;
 	}
@@ -246,6 +258,7 @@ int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
 	}
 
 	fs_info->zone_size = zone_size;
+	fs_info->max_zone_append_size = max_zone_append_size;
 
 	btrfs_info(fs_info, "ZONED mode enabled, zone size %llu B",
 		   fs_info->zone_size);
diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h
index c4c63c4294f2..a63f6177f9ee 100644
--- a/fs/btrfs/zoned.h
+++ b/fs/btrfs/zoned.h
@@ -12,6 +12,7 @@ struct btrfs_zoned_device_info {
 	 */
 	u64 zone_size;
 	u8  zone_size_shift;
+	u64 max_zone_append_size;
 	u32 nr_zones;
 	unsigned long *seq_zones;
 	unsigned long *empty_zones;
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 07/41] btrfs: disallow space_cache in ZONED mode
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (4 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 06/41] btrfs: introduce max_zone_append_size Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-02 17:02     ` Josef Bacik
  2020-11-03 12:48     ` David Sterba
  2020-10-30 13:51   ` [PATCH v9 08/41] btrfs: disallow NODATACOW " Naohiro Aota
                     ` (34 subsequent siblings)
  40 siblings, 2 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

As updates to the space cache v1 are in-place, the space cache cannot be
located over sequential zones and there is no guarantees that the device
will have enough conventional zones to store this cache. Resolve this
problem by disabling completely the space cache v1.  This does not
introduces any problems with sequential block groups: all the free space is
located after the allocation pointer and no free space before the pointer.
There is no need to have such cache.

Note: we can technically use free-space-tree (space cache v2) on ZONED
mode. But, since ZONED mode now always allocate extents in a block group
sequentially regardless of underlying device zone type, it's no use to
enable and maintain the tree.

For the same reason, NODATACOW is also disabled.

Also INODE_MAP_CACHE is also disabled to avoid preallocation in the
INODE_MAP_CACHE inode.

In summary, ZONED will disable:

| Disabled features | Reason                                              |
|-------------------+-----------------------------------------------------|
| RAID/Dup          | Cannot handle two zone append writes to different   |
|                   | zones                                               |
|-------------------+-----------------------------------------------------|
| space_cache (v1)  | In-place updating                                   |
| NODATACOW         | In-place updating                                   |
|-------------------+-----------------------------------------------------|
| fallocate         | Reserved extent will be a write hole                |
| INODE_MAP_CACHE   | Need pre-allocation. (and will be deprecated?)      |
|-------------------+-----------------------------------------------------|
| MIXED_BG          | Allocated metadata region will be write holes for   |
|                   | data writes                                         |

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/super.c | 12 ++++++++++--
 fs/btrfs/zoned.c | 18 ++++++++++++++++++
 fs/btrfs/zoned.h |  5 +++++
 3 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 3312fe08168f..9064ca62b0a0 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -525,8 +525,14 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
 	cache_gen = btrfs_super_cache_generation(info->super_copy);
 	if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE))
 		btrfs_set_opt(info->mount_opt, FREE_SPACE_TREE);
-	else if (cache_gen)
-		btrfs_set_opt(info->mount_opt, SPACE_CACHE);
+	else if (cache_gen) {
+		if (btrfs_is_zoned(info)) {
+			btrfs_info(info,
+			"clearring existing space cache in ZONED mode");
+			btrfs_set_super_cache_generation(info->super_copy, 0);
+		} else
+			btrfs_set_opt(info->mount_opt, SPACE_CACHE);
+	}
 
 	/*
 	 * Even the options are empty, we still need to do extra check
@@ -985,6 +991,8 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
 		ret = -EINVAL;
 
 	}
+	if (!ret)
+		ret = btrfs_check_mountopts_zoned(info);
 	if (!ret && btrfs_test_opt(info, SPACE_CACHE))
 		btrfs_info(info, "disk space caching is enabled");
 	if (!ret && btrfs_test_opt(info, FREE_SPACE_TREE))
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index 1b42e13b8227..3885fa327049 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -265,3 +265,21 @@ int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
 out:
 	return ret;
 }
+
+int btrfs_check_mountopts_zoned(struct btrfs_fs_info *info)
+{
+	if (!btrfs_is_zoned(info))
+		return 0;
+
+	/*
+	 * SPACE CACHE writing is not CoWed. Disable that to avoid write
+	 * errors in sequential zones.
+	 */
+	if (btrfs_test_opt(info, SPACE_CACHE)) {
+		btrfs_err(info,
+			  "space cache v1 not supportted in ZONED mode");
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h
index a63f6177f9ee..0b7756a7104d 100644
--- a/fs/btrfs/zoned.h
+++ b/fs/btrfs/zoned.h
@@ -24,6 +24,7 @@ int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
 int btrfs_get_dev_zone_info(struct btrfs_device *device);
 void btrfs_destroy_dev_zone_info(struct btrfs_device *device);
 int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info);
+int btrfs_check_mountopts_zoned(struct btrfs_fs_info *info);
 #else /* CONFIG_BLK_DEV_ZONED */
 static inline int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
 				     struct blk_zone *zone)
@@ -43,6 +44,10 @@ static inline int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
 	btrfs_err(fs_info, "Zoned block devices support is not enabled");
 	return -EOPNOTSUPP;
 }
+static inline int btrfs_check_mountopts_zoned(struct btrfs_fs_info *info)
+{
+	return 0;
+}
 #endif
 
 static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos)
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 08/41] btrfs: disallow NODATACOW in ZONED mode
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (5 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 07/41] btrfs: disallow space_cache in ZONED mode Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-02 17:05     ` Josef Bacik
  2020-11-03 12:57     ` David Sterba
  2020-10-30 13:51   ` [PATCH v9 09/41] btrfs: disable fallocate " Naohiro Aota
                     ` (33 subsequent siblings)
  40 siblings, 2 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba
  Cc: hare, linux-fsdevel, Naohiro Aota, Johannes Thumshirn

NODATACOW implies overwriting the file data on a device, which is
impossible in sequential required zones. Disable NODATACOW globally with
mount option and per-file NODATACOW attribute by masking FS_NOCOW_FL.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/ioctl.c | 16 ++++++++++++++++
 fs/btrfs/zoned.c |  6 ++++++
 2 files changed, 22 insertions(+)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index ab408a23ba32..e1036a9ce881 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -193,6 +193,18 @@ static int check_fsflags(unsigned int old_flags, unsigned int flags)
 	return 0;
 }
 
+static int check_fsflags_compatible(struct btrfs_fs_info *fs_info,
+				    unsigned int flags)
+{
+	bool zoned = btrfs_is_zoned(fs_info);
+
+	if (zoned && (flags & FS_NOCOW_FL))
+		return -EPERM;
+
+	return 0;
+}
+
+
 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 {
 	struct inode *inode = file_inode(file);
@@ -230,6 +242,10 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 	if (ret)
 		goto out_unlock;
 
+	ret = check_fsflags_compatible(fs_info, fsflags);
+	if (ret)
+		goto out_unlock;
+
 	binode_flags = binode->flags;
 	if (fsflags & FS_SYNC_FL)
 		binode_flags |= BTRFS_INODE_SYNC;
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index 3885fa327049..1939b3ee6c10 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -281,5 +281,11 @@ int btrfs_check_mountopts_zoned(struct btrfs_fs_info *info)
 		return -EOPNOTSUPP;
 	}
 
+	if (btrfs_test_opt(info, NODATACOW)) {
+		btrfs_err(info,
+		  "cannot enable nodatacow with ZONED mode");
+		return -EOPNOTSUPP;
+	}
+
 	return 0;
 }
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 09/41] btrfs: disable fallocate in ZONED mode
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (6 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 08/41] btrfs: disallow NODATACOW " Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 13:00     ` David Sterba
  2020-10-30 13:51   ` [PATCH v9 10/41] btrfs: disallow mixed-bg " Naohiro Aota
                     ` (32 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba
  Cc: hare, linux-fsdevel, Naohiro Aota, Johannes Thumshirn, Josef Bacik

fallocate() is implemented by reserving actual extent instead of
reservations. This can result in exposing the sequential write constraint
of host-managed zoned block devices to the application, which would break
the POSIX semantic for the fallocated file.  To avoid this, report
fallocate() as not supported when in ZONED mode for now.

In the future, we may be able to implement "in-memory" fallocate() in ZONED
mode by utilizing space_info->bytes_may_use or so.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/file.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 0ff659455b1e..68938a43081e 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -3341,6 +3341,10 @@ static long btrfs_fallocate(struct file *file, int mode,
 	alloc_end = round_up(offset + len, blocksize);
 	cur_offset = alloc_start;
 
+	/* Do not allow fallocate in ZONED mode */
+	if (btrfs_is_zoned(btrfs_sb(inode->i_sb)))
+		return -EOPNOTSUPP;
+
 	/* Make sure we aren't being give some crap mode */
 	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
 		     FALLOC_FL_ZERO_RANGE))
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 10/41] btrfs: disallow mixed-bg in ZONED mode
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (7 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 09/41] btrfs: disable fallocate " Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 13:01     ` David Sterba
  2020-10-30 13:51   ` [PATCH v9 11/41] btrfs: implement log-structured superblock for " Naohiro Aota
                     ` (31 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota, Josef Bacik

Placing both data and metadata in a block group is impossible in ZONED
mode. For data, we can allocate a space for it and write it immediately
after the allocation. For metadata, however, we cannot do so, because the
logical addresses are recorded in other metadata buffers to build up the
trees. As a result, a data buffer can be placed after a metadata buffer,
which is not written yet. Writing out the data buffer will break the
sequential write rule.

This commit check and disallow MIXED_BG with ZONED mode.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/zoned.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index 1939b3ee6c10..ae509699da14 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -257,6 +257,13 @@ int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
 		goto out;
 	}
 
+	if (btrfs_fs_incompat(fs_info, MIXED_GROUPS)) {
+		btrfs_err(fs_info,
+			  "ZONED mode is not allowed for mixed block groups");
+		ret = -EINVAL;
+		goto out;
+	}
+
 	fs_info->zone_size = zone_size;
 	fs_info->max_zone_append_size = max_zone_append_size;
 
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 11/41] btrfs: implement log-structured superblock for ZONED mode
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (8 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 10/41] btrfs: disallow mixed-bg " Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-02 18:22     ` Josef Bacik
                       ` (3 more replies)
  2020-10-30 13:51   ` [PATCH v9 12/41] btrfs: implement zoned chunk allocator Naohiro Aota
                     ` (30 subsequent siblings)
  40 siblings, 4 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

Superblock (and its copies) is the only data structure in btrfs which has a
fixed location on a device. Since we cannot overwrite in a sequential write
required zone, we cannot place superblock in the zone. One easy solution is
limiting superblock and copies to be placed only in conventional zones.
However, this method has two downsides: one is reduced number of superblock
copies. The location of the second copy of superblock is 256GB, which is in
a sequential write required zone on typical devices in the market today.
So, the number of superblock and copies is limited to be two.  Second
downside is that we cannot support devices which have no conventional zones
at all.

To solve these two problems, we employ superblock log writing. It uses two
zones as a circular buffer to write updated superblocks. Once the first
zone is filled up, start writing into the second buffer. Then, when the
both zones are filled up and before start writing to the first zone again,
it reset the first zone.

We can determine the position of the latest superblock by reading write
pointer information from a device. One corner case is when the both zones
are full. For this situation, we read out the last superblock of each
zone, and compare them to determine which zone is older.

The following zones are reserved as the circular buffer on ZONED btrfs.

- The primary superblock: zones 0 and 1
- The first copy: zones 16 and 17
- The second copy: zones 1024 or zone at 256GB which is minimum, and next
  to it

If these reserved zones are conventional, superblock is written fixed at
the start of the zone without logging.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/block-group.c |   9 ++
 fs/btrfs/disk-io.c     |  41 +++++-
 fs/btrfs/scrub.c       |   3 +
 fs/btrfs/volumes.c     |  21 ++-
 fs/btrfs/zoned.c       | 311 +++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/zoned.h       |  40 ++++++
 6 files changed, 413 insertions(+), 12 deletions(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index c0f1d6818df7..e989c66aa764 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -1723,6 +1723,7 @@ int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
 static int exclude_super_stripes(struct btrfs_block_group *cache)
 {
 	struct btrfs_fs_info *fs_info = cache->fs_info;
+	bool zoned = btrfs_is_zoned(fs_info);
 	u64 bytenr;
 	u64 *logical;
 	int stripe_len;
@@ -1744,6 +1745,14 @@ static int exclude_super_stripes(struct btrfs_block_group *cache)
 		if (ret)
 			return ret;
 
+		/* shouldn't have super stripes in sequential zones */
+		if (zoned && nr) {
+			btrfs_err(fs_info,
+				  "Zoned btrfs's block group %llu should not have super blocks",
+				  cache->start);
+			return -EUCLEAN;
+		}
+
 		while (nr--) {
 			u64 len = min_t(u64, stripe_len,
 				cache->start + cache->length - logical[nr]);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 9bc51cff48b8..fd8b970ee92c 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3423,10 +3423,17 @@ struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev,
 {
 	struct btrfs_super_block *super;
 	struct page *page;
-	u64 bytenr;
+	u64 bytenr, bytenr_orig;
 	struct address_space *mapping = bdev->bd_inode->i_mapping;
+	int ret;
+
+	bytenr_orig = btrfs_sb_offset(copy_num);
+	ret = btrfs_sb_log_location_bdev(bdev, copy_num, READ, &bytenr);
+	if (ret == -ENOENT)
+		return ERR_PTR(-EINVAL);
+	else if (ret)
+		return ERR_PTR(ret);
 
-	bytenr = btrfs_sb_offset(copy_num);
 	if (bytenr + BTRFS_SUPER_INFO_SIZE >= i_size_read(bdev->bd_inode))
 		return ERR_PTR(-EINVAL);
 
@@ -3440,7 +3447,7 @@ struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev,
 		return ERR_PTR(-ENODATA);
 	}
 
-	if (btrfs_super_bytenr(super) != bytenr) {
+	if (btrfs_super_bytenr(super) != bytenr_orig) {
 		btrfs_release_disk_super(super);
 		return ERR_PTR(-EINVAL);
 	}
@@ -3495,7 +3502,8 @@ static int write_dev_supers(struct btrfs_device *device,
 	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
 	int i;
 	int errors = 0;
-	u64 bytenr;
+	int ret;
+	u64 bytenr, bytenr_orig;
 
 	if (max_mirrors == 0)
 		max_mirrors = BTRFS_SUPER_MIRROR_MAX;
@@ -3507,12 +3515,21 @@ static int write_dev_supers(struct btrfs_device *device,
 		struct bio *bio;
 		struct btrfs_super_block *disk_super;
 
-		bytenr = btrfs_sb_offset(i);
+		bytenr_orig = btrfs_sb_offset(i);
+		ret = btrfs_sb_log_location(device, i, WRITE, &bytenr);
+		if (ret == -ENOENT)
+			continue;
+		else if (ret < 0) {
+			btrfs_err(device->fs_info, "couldn't get super block location for mirror %d",
+				  i);
+			errors++;
+			continue;
+		}
 		if (bytenr + BTRFS_SUPER_INFO_SIZE >=
 		    device->commit_total_bytes)
 			break;
 
-		btrfs_set_super_bytenr(sb, bytenr);
+		btrfs_set_super_bytenr(sb, bytenr_orig);
 
 		crypto_shash_digest(shash, (const char *)sb + BTRFS_CSUM_SIZE,
 				    BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE,
@@ -3557,6 +3574,7 @@ static int write_dev_supers(struct btrfs_device *device,
 			bio->bi_opf |= REQ_FUA;
 
 		btrfsic_submit_bio(bio);
+		btrfs_advance_sb_log(device, i);
 	}
 	return errors < i ? 0 : -1;
 }
@@ -3573,6 +3591,7 @@ static int wait_dev_supers(struct btrfs_device *device, int max_mirrors)
 	int i;
 	int errors = 0;
 	bool primary_failed = false;
+	int ret;
 	u64 bytenr;
 
 	if (max_mirrors == 0)
@@ -3581,7 +3600,15 @@ static int wait_dev_supers(struct btrfs_device *device, int max_mirrors)
 	for (i = 0; i < max_mirrors; i++) {
 		struct page *page;
 
-		bytenr = btrfs_sb_offset(i);
+		ret = btrfs_sb_log_location(device, i, READ, &bytenr);
+		if (ret == -ENOENT)
+			break;
+		else if (ret < 0) {
+			errors++;
+			if (i == 0)
+				primary_failed = true;
+			continue;
+		}
 		if (bytenr + BTRFS_SUPER_INFO_SIZE >=
 		    device->commit_total_bytes)
 			break;
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index cf63f1e27a27..aa1b36cf5c88 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -20,6 +20,7 @@
 #include "rcu-string.h"
 #include "raid56.h"
 #include "block-group.h"
+#include "zoned.h"
 
 /*
  * This is only the first step towards a full-features scrub. It reads all
@@ -3704,6 +3705,8 @@ static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
 		if (bytenr + BTRFS_SUPER_INFO_SIZE >
 		    scrub_dev->commit_total_bytes)
 			break;
+		if (!btrfs_check_super_location(scrub_dev, bytenr))
+			continue;
 
 		ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
 				  scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 10827892c086..db884b96a5ea 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1282,7 +1282,8 @@ void btrfs_release_disk_super(struct btrfs_super_block *super)
 }
 
 static struct btrfs_super_block *btrfs_read_disk_super(struct block_device *bdev,
-						       u64 bytenr)
+						       u64 bytenr,
+						       u64 bytenr_orig)
 {
 	struct btrfs_super_block *disk_super;
 	struct page *page;
@@ -1313,7 +1314,7 @@ static struct btrfs_super_block *btrfs_read_disk_super(struct block_device *bdev
 	/* align our pointer to the offset of the super block */
 	disk_super = p + offset_in_page(bytenr);
 
-	if (btrfs_super_bytenr(disk_super) != bytenr ||
+	if (btrfs_super_bytenr(disk_super) != bytenr_orig ||
 	    btrfs_super_magic(disk_super) != BTRFS_MAGIC) {
 		btrfs_release_disk_super(p);
 		return ERR_PTR(-EINVAL);
@@ -1348,7 +1349,8 @@ struct btrfs_device *btrfs_scan_one_device(const char *path, fmode_t flags,
 	bool new_device_added = false;
 	struct btrfs_device *device = NULL;
 	struct block_device *bdev;
-	u64 bytenr;
+	u64 bytenr, bytenr_orig;
+	int ret;
 
 	lockdep_assert_held(&uuid_mutex);
 
@@ -1358,14 +1360,18 @@ struct btrfs_device *btrfs_scan_one_device(const char *path, fmode_t flags,
 	 * So, we need to add a special mount option to scan for
 	 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
 	 */
-	bytenr = btrfs_sb_offset(0);
 	flags |= FMODE_EXCL;
 
 	bdev = blkdev_get_by_path(path, flags, holder);
 	if (IS_ERR(bdev))
 		return ERR_CAST(bdev);
 
-	disk_super = btrfs_read_disk_super(bdev, bytenr);
+	bytenr_orig = btrfs_sb_offset(0);
+	ret = btrfs_sb_log_location_bdev(bdev, 0, READ, &bytenr);
+	if (ret)
+		return ERR_PTR(ret);
+
+	disk_super = btrfs_read_disk_super(bdev, bytenr, bytenr_orig);
 	if (IS_ERR(disk_super)) {
 		device = ERR_CAST(disk_super);
 		goto error_bdev_put;
@@ -2029,6 +2035,11 @@ void btrfs_scratch_superblocks(struct btrfs_fs_info *fs_info,
 		if (IS_ERR(disk_super))
 			continue;
 
+		if (bdev_is_zoned(bdev)) {
+			btrfs_reset_sb_log_zones(bdev, copy_num);
+			continue;
+		}
+
 		memset(&disk_super->magic, 0, sizeof(disk_super->magic));
 
 		page = virt_to_page(disk_super);
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index ae509699da14..d5487cba203b 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -20,6 +20,25 @@ static int copy_zone_info_cb(struct blk_zone *zone, unsigned int idx,
 	return 0;
 }
 
+static int sb_write_pointer(struct block_device *bdev, struct blk_zone *zone,
+			    u64 *wp_ret);
+
+static inline u32 sb_zone_number(u8 shift, int mirror)
+{
+	ASSERT(mirror < BTRFS_SUPER_MIRROR_MAX);
+
+	switch (mirror) {
+	case 0:
+		return 0;
+	case 1:
+		return 16;
+	case 2:
+		return min(btrfs_sb_offset(mirror) >> shift, 1024ULL);
+	}
+
+	return 0;
+}
+
 static int btrfs_get_dev_zones(struct btrfs_device *device, u64 pos,
 			       struct blk_zone *zones, unsigned int *nr_zones)
 {
@@ -123,6 +142,49 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device)
 		goto out;
 	}
 
+	/* validate superblock log */
+	nr_zones = 2;
+	for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
+		u32 sb_zone = sb_zone_number(zone_info->zone_size_shift, i);
+		u64 sb_wp;
+
+		if (sb_zone + 1 >= zone_info->nr_zones)
+			continue;
+
+		sector = sb_zone << (zone_info->zone_size_shift - SECTOR_SHIFT);
+		ret = btrfs_get_dev_zones(device, sector << SECTOR_SHIFT,
+					  &zone_info->sb_zones[2 * i],
+					  &nr_zones);
+		if (ret)
+			goto out;
+		if (nr_zones != 2) {
+			btrfs_err_in_rcu(device->fs_info,
+			"failed to read SB log zone info at device %s zone %u",
+					 rcu_str_deref(device->name), sb_zone);
+			ret = -EIO;
+			goto out;
+		}
+
+		/*
+		 * If zones[0] is conventional, always use the beggining of
+		 * the zone to record superblock. No need to validate in
+		 * that case.
+		 */
+		if (zone_info->sb_zones[2 * i].type == BLK_ZONE_TYPE_CONVENTIONAL)
+			continue;
+
+		ret = sb_write_pointer(device->bdev,
+				       &zone_info->sb_zones[2 * i], &sb_wp);
+		if (ret != -ENOENT && ret) {
+			btrfs_err_in_rcu(device->fs_info,
+				"SB log zone corrupted: device %s zone %u",
+					 rcu_str_deref(device->name), sb_zone);
+			ret = -EUCLEAN;
+			goto out;
+		}
+	}
+
+
 	kfree(zones);
 
 	device->zone_info = zone_info;
@@ -296,3 +358,252 @@ int btrfs_check_mountopts_zoned(struct btrfs_fs_info *info)
 
 	return 0;
 }
+
+static int sb_write_pointer(struct block_device *bdev, struct blk_zone *zones,
+			    u64 *wp_ret)
+{
+	bool empty[2];
+	bool full[2];
+	sector_t sector;
+
+	ASSERT(zones[0].type != BLK_ZONE_TYPE_CONVENTIONAL &&
+	       zones[1].type != BLK_ZONE_TYPE_CONVENTIONAL);
+
+	empty[0] = zones[0].cond == BLK_ZONE_COND_EMPTY;
+	empty[1] = zones[1].cond == BLK_ZONE_COND_EMPTY;
+	full[0] = zones[0].cond == BLK_ZONE_COND_FULL;
+	full[1] = zones[1].cond == BLK_ZONE_COND_FULL;
+
+	/*
+	 * Possible state of log buffer zones
+	 *
+	 *   E I F
+	 * E * x 0
+	 * I 0 x 0
+	 * F 1 1 C
+	 *
+	 * Row: zones[0]
+	 * Col: zones[1]
+	 * State:
+	 *   E: Empty, I: In-Use, F: Full
+	 * Log position:
+	 *   *: Special case, no superblock is written
+	 *   0: Use write pointer of zones[0]
+	 *   1: Use write pointer of zones[1]
+	 *   C: Compare SBs from zones[0] and zones[1], use the newer one
+	 *   x: Invalid state
+	 */
+
+	if (empty[0] && empty[1]) {
+		/* special case to distinguish no superblock to read */
+		*wp_ret = zones[0].start << SECTOR_SHIFT;
+		return -ENOENT;
+	} else if (full[0] && full[1]) {
+		/* Compare two super blocks */
+		struct address_space *mapping = bdev->bd_inode->i_mapping;
+		struct page *page[2];
+		struct btrfs_super_block *super[2];
+		int i;
+
+		for (i = 0; i < 2; i++) {
+			u64 bytenr = ((zones[i].start + zones[i].len) << SECTOR_SHIFT) -
+				BTRFS_SUPER_INFO_SIZE;
+
+			page[i] = read_cache_page_gfp(mapping, bytenr >> PAGE_SHIFT, GFP_NOFS);
+			if (IS_ERR(page[i])) {
+				if (i == 1)
+					btrfs_release_disk_super(super[0]);
+				return PTR_ERR(page[i]);
+			}
+			super[i] = page_address(page[i]);
+		}
+
+		if (super[0]->generation > super[1]->generation)
+			sector = zones[1].start;
+		else
+			sector = zones[0].start;
+
+		for (i = 0; i < 2; i++)
+			btrfs_release_disk_super(super[i]);
+	} else if (!full[0] && (empty[1] || full[1])) {
+		sector = zones[0].wp;
+	} else if (full[0]) {
+		sector = zones[1].wp;
+	} else {
+		return -EUCLEAN;
+	}
+	*wp_ret = sector << SECTOR_SHIFT;
+	return 0;
+}
+
+static int sb_log_location(struct block_device *bdev, struct blk_zone *zones,
+			   int rw, u64 *bytenr_ret)
+{
+	u64 wp;
+	int ret;
+
+	if (zones[0].type == BLK_ZONE_TYPE_CONVENTIONAL) {
+		*bytenr_ret = zones[0].start << SECTOR_SHIFT;
+		return 0;
+	}
+
+	ret = sb_write_pointer(bdev, zones, &wp);
+	if (ret != -ENOENT && ret < 0)
+		return ret;
+
+	if (rw == WRITE) {
+		struct blk_zone *reset = NULL;
+
+		if (wp == zones[0].start << SECTOR_SHIFT)
+			reset = &zones[0];
+		else if (wp == zones[1].start << SECTOR_SHIFT)
+			reset = &zones[1];
+
+		if (reset && reset->cond != BLK_ZONE_COND_EMPTY) {
+			ASSERT(reset->cond == BLK_ZONE_COND_FULL);
+
+			ret = blkdev_zone_mgmt(bdev, REQ_OP_ZONE_RESET,
+					       reset->start, reset->len,
+					       GFP_NOFS);
+			if (ret)
+				return ret;
+
+			reset->cond = BLK_ZONE_COND_EMPTY;
+			reset->wp = reset->start;
+		}
+	} else if (ret != -ENOENT) {
+		/* For READ, we want the precious one */
+		if (wp == zones[0].start << SECTOR_SHIFT)
+			wp = (zones[1].start + zones[1].len) << SECTOR_SHIFT;
+		wp -= BTRFS_SUPER_INFO_SIZE;
+	}
+
+	*bytenr_ret = wp;
+	return 0;
+
+}
+
+int btrfs_sb_log_location_bdev(struct block_device *bdev, int mirror, int rw,
+			       u64 *bytenr_ret)
+{
+	struct blk_zone zones[2];
+	unsigned int zone_sectors;
+	u32 sb_zone;
+	int ret;
+	u64 zone_size;
+	u8 zone_sectors_shift;
+	sector_t nr_sectors = bdev->bd_part->nr_sects;
+	u32 nr_zones;
+
+	if (!bdev_is_zoned(bdev)) {
+		*bytenr_ret = btrfs_sb_offset(mirror);
+		return 0;
+	}
+
+	ASSERT(rw == READ || rw == WRITE);
+
+	zone_sectors = bdev_zone_sectors(bdev);
+	if (!is_power_of_2(zone_sectors))
+		return -EINVAL;
+	zone_size = zone_sectors << SECTOR_SHIFT;
+	zone_sectors_shift = ilog2(zone_sectors);
+	nr_zones = nr_sectors >> zone_sectors_shift;
+
+	sb_zone = sb_zone_number(zone_sectors_shift + SECTOR_SHIFT, mirror);
+	if (sb_zone + 1 >= nr_zones)
+		return -ENOENT;
+
+	ret = blkdev_report_zones(bdev, sb_zone << zone_sectors_shift, 2,
+				  copy_zone_info_cb, zones);
+	if (ret < 0)
+		return ret;
+	if (ret != 2)
+		return -EIO;
+
+	return sb_log_location(bdev, zones, rw, bytenr_ret);
+}
+
+int btrfs_sb_log_location(struct btrfs_device *device, int mirror, int rw,
+			  u64 *bytenr_ret)
+{
+	struct btrfs_zoned_device_info *zinfo = device->zone_info;
+	u32 zone_num;
+
+	if (!zinfo) {
+		*bytenr_ret = btrfs_sb_offset(mirror);
+		return 0;
+	}
+
+	zone_num = sb_zone_number(zinfo->zone_size_shift, mirror);
+	if (zone_num + 1 >= zinfo->nr_zones)
+		return -ENOENT;
+
+	return sb_log_location(device->bdev, &zinfo->sb_zones[2 * mirror], rw,
+			       bytenr_ret);
+}
+
+static inline bool is_sb_log_zone(struct btrfs_zoned_device_info *zinfo,
+				  int mirror)
+{
+	u32 zone_num;
+
+	if (!zinfo)
+		return false;
+
+	zone_num = sb_zone_number(zinfo->zone_size_shift, mirror);
+	if (zone_num + 1 >= zinfo->nr_zones)
+		return false;
+
+	if (!test_bit(zone_num, zinfo->seq_zones))
+		return false;
+
+	return true;
+}
+
+void btrfs_advance_sb_log(struct btrfs_device *device, int mirror)
+{
+	struct btrfs_zoned_device_info *zinfo = device->zone_info;
+	struct blk_zone *zone;
+
+	if (!is_sb_log_zone(zinfo, mirror))
+		return;
+
+	zone = &zinfo->sb_zones[2 * mirror];
+	if (zone->cond != BLK_ZONE_COND_FULL) {
+		if (zone->cond == BLK_ZONE_COND_EMPTY)
+			zone->cond = BLK_ZONE_COND_IMP_OPEN;
+		zone->wp += (BTRFS_SUPER_INFO_SIZE >> SECTOR_SHIFT);
+		if (zone->wp == zone->start + zone->len)
+			zone->cond = BLK_ZONE_COND_FULL;
+		return;
+	}
+
+	zone++;
+	ASSERT(zone->cond != BLK_ZONE_COND_FULL);
+	if (zone->cond == BLK_ZONE_COND_EMPTY)
+		zone->cond = BLK_ZONE_COND_IMP_OPEN;
+	zone->wp += (BTRFS_SUPER_INFO_SIZE >> SECTOR_SHIFT);
+	if (zone->wp == zone->start + zone->len)
+		zone->cond = BLK_ZONE_COND_FULL;
+}
+
+int btrfs_reset_sb_log_zones(struct block_device *bdev, int mirror)
+{
+	sector_t zone_sectors;
+	sector_t nr_sectors = bdev->bd_part->nr_sects;
+	u8 zone_sectors_shift;
+	u32 sb_zone;
+	u32 nr_zones;
+
+	zone_sectors = bdev_zone_sectors(bdev);
+	zone_sectors_shift = ilog2(zone_sectors);
+	nr_zones = nr_sectors >> zone_sectors_shift;
+
+	sb_zone = sb_zone_number(zone_sectors_shift + SECTOR_SHIFT, mirror);
+	if (sb_zone + 1 >= nr_zones)
+		return -ENOENT;
+
+	return blkdev_zone_mgmt(bdev, REQ_OP_ZONE_RESET,
+				sb_zone << zone_sectors_shift, zone_sectors * 2,
+				GFP_NOFS);
+}
diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h
index 0b7756a7104d..447c4e5ffcbb 100644
--- a/fs/btrfs/zoned.h
+++ b/fs/btrfs/zoned.h
@@ -4,6 +4,8 @@
 #define BTRFS_ZONED_H
 
 #include <linux/blkdev.h>
+#include "volumes.h"
+#include "disk-io.h"
 
 struct btrfs_zoned_device_info {
 	/*
@@ -16,6 +18,7 @@ struct btrfs_zoned_device_info {
 	u32 nr_zones;
 	unsigned long *seq_zones;
 	unsigned long *empty_zones;
+	struct blk_zone sb_zones[2 * BTRFS_SUPER_MIRROR_MAX];
 };
 
 #ifdef CONFIG_BLK_DEV_ZONED
@@ -25,6 +28,12 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device);
 void btrfs_destroy_dev_zone_info(struct btrfs_device *device);
 int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info);
 int btrfs_check_mountopts_zoned(struct btrfs_fs_info *info);
+int btrfs_sb_log_location_bdev(struct block_device *bdev, int mirror, int rw,
+			       u64 *bytenr_ret);
+int btrfs_sb_log_location(struct btrfs_device *device, int mirror, int rw,
+			  u64 *bytenr_ret);
+void btrfs_advance_sb_log(struct btrfs_device *device, int mirror);
+int btrfs_reset_sb_log_zones(struct block_device *bdev, int mirror);
 #else /* CONFIG_BLK_DEV_ZONED */
 static inline int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
 				     struct blk_zone *zone)
@@ -48,6 +57,26 @@ static inline int btrfs_check_mountopts_zoned(struct btrfs_fs_info *info)
 {
 	return 0;
 }
+static inline int btrfs_sb_log_location_bdev(struct block_device *bdev,
+					     int mirror, int rw,
+					     u64 *bytenr_ret)
+{
+	*bytenr_ret = btrfs_sb_offset(mirror);
+	return 0;
+}
+static inline int btrfs_sb_log_location(struct btrfs_device *device, int mirror,
+					int rw, u64 *bytenr_ret)
+{
+	*bytenr_ret = btrfs_sb_offset(mirror);
+	return 0;
+}
+static inline void btrfs_advance_sb_log(struct btrfs_device *device,
+					int mirror) { }
+static inline int btrfs_reset_sb_log_zones(struct block_device *bdev,
+					   int mirror)
+{
+	return 0;
+}
 #endif
 
 static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos)
@@ -115,4 +144,15 @@ static inline bool btrfs_check_device_zone_type(struct btrfs_fs_info *fs_info,
 	return bdev_zoned_model(bdev) != BLK_ZONED_HM;
 }
 
+static inline bool btrfs_check_super_location(struct btrfs_device *device,
+					      u64 pos)
+{
+	/*
+	 * On a non-zoned device, any address is OK. On a zoned device,
+	 * non-SEQUENTIAL WRITE REQUIRED zones are capable.
+	 */
+	return device->zone_info == NULL ||
+	       !btrfs_dev_is_sequential(device, pos);
+}
+
 #endif
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 12/41] btrfs: implement zoned chunk allocator
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (9 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 11/41] btrfs: implement log-structured superblock for " Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-02 20:09     ` Josef Bacik
  2020-11-03 13:23     ` David Sterba
  2020-10-30 13:51   ` [PATCH v9 13/41] btrfs: verify device extent is aligned to zone Naohiro Aota
                     ` (29 subsequent siblings)
  40 siblings, 2 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

This commit implements a zoned chunk/dev_extent allocator. The zoned
allocator aligns the device extents to zone boundaries, so that a zone
reset affects only the device extent and does not change the state of
blocks in the neighbor device extents.

Also, it checks that a region allocation is not overlapping any of the
super block zones, and ensures the region is empty.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/volumes.c | 131 +++++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/volumes.h |   1 +
 fs/btrfs/zoned.c   | 126 +++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/zoned.h   |  30 +++++++++++
 4 files changed, 288 insertions(+)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index db884b96a5ea..78c62ef02e6f 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1416,6 +1416,14 @@ static bool contains_pending_extent(struct btrfs_device *device, u64 *start,
 	return false;
 }
 
+static inline u64 dev_extent_search_start_zoned(struct btrfs_device *device,
+						u64 start)
+{
+	start = max_t(u64, start,
+		      max_t(u64, device->zone_info->zone_size, SZ_1M));
+	return btrfs_zone_align(device, start);
+}
+
 static u64 dev_extent_search_start(struct btrfs_device *device, u64 start)
 {
 	switch (device->fs_devices->chunk_alloc_policy) {
@@ -1426,11 +1434,57 @@ static u64 dev_extent_search_start(struct btrfs_device *device, u64 start)
 		 * make sure to start at an offset of at least 1MB.
 		 */
 		return max_t(u64, start, SZ_1M);
+	case BTRFS_CHUNK_ALLOC_ZONED:
+		return dev_extent_search_start_zoned(device, start);
 	default:
 		BUG();
 	}
 }
 
+static bool dev_extent_hole_check_zoned(struct btrfs_device *device,
+					u64 *hole_start, u64 *hole_size,
+					u64 num_bytes)
+{
+	u64 zone_size = device->zone_info->zone_size;
+	u64 pos;
+	int ret;
+	int changed = 0;
+
+	ASSERT(IS_ALIGNED(*hole_start, zone_size));
+
+	while (*hole_size > 0) {
+		pos = btrfs_find_allocatable_zones(device, *hole_start,
+						   *hole_start + *hole_size,
+						   num_bytes);
+		if (pos != *hole_start) {
+			*hole_size = *hole_start + *hole_size - pos;
+			*hole_start = pos;
+			changed = 1;
+			if (*hole_size < num_bytes)
+				break;
+		}
+
+		ret = btrfs_ensure_empty_zones(device, pos, num_bytes);
+
+		/* range is ensured to be empty */
+		if (!ret)
+			return changed;
+
+		/* given hole range was invalid (outside of device) */
+		if (ret == -ERANGE) {
+			*hole_start += *hole_size;
+			*hole_size = 0;
+			return 1;
+		}
+
+		*hole_start += zone_size;
+		*hole_size -= zone_size;
+		changed = 1;
+	}
+
+	return changed;
+}
+
 /**
  * dev_extent_hole_check - check if specified hole is suitable for allocation
  * @device:	the device which we have the hole
@@ -1463,6 +1517,10 @@ static bool dev_extent_hole_check(struct btrfs_device *device, u64 *hole_start,
 	case BTRFS_CHUNK_ALLOC_REGULAR:
 		/* No extra check */
 		break;
+	case BTRFS_CHUNK_ALLOC_ZONED:
+		changed |= dev_extent_hole_check_zoned(device, hole_start,
+						       hole_size, num_bytes);
+		break;
 	default:
 		BUG();
 	}
@@ -1517,6 +1575,9 @@ static int find_free_dev_extent_start(struct btrfs_device *device,
 
 	search_start = dev_extent_search_start(device, search_start);
 
+	WARN_ON(device->zone_info &&
+		!IS_ALIGNED(num_bytes, device->zone_info->zone_size));
+
 	path = btrfs_alloc_path();
 	if (!path)
 		return -ENOMEM;
@@ -4907,6 +4968,37 @@ static void init_alloc_chunk_ctl_policy_regular(
 	ctl->dev_extent_min = BTRFS_STRIPE_LEN * ctl->dev_stripes;
 }
 
+static void
+init_alloc_chunk_ctl_policy_zoned(struct btrfs_fs_devices *fs_devices,
+				  struct alloc_chunk_ctl *ctl)
+{
+	u64 zone_size = fs_devices->fs_info->zone_size;
+	u64 limit;
+	int min_num_stripes = ctl->devs_min * ctl->dev_stripes;
+	int min_data_stripes = (min_num_stripes - ctl->nparity) / ctl->ncopies;
+	u64 min_chunk_size = min_data_stripes * zone_size;
+	u64 type = ctl->type;
+
+	ctl->max_stripe_size = zone_size;
+	if (type & BTRFS_BLOCK_GROUP_DATA) {
+		ctl->max_chunk_size = round_down(BTRFS_MAX_DATA_CHUNK_SIZE,
+						 zone_size);
+	} else if (type & BTRFS_BLOCK_GROUP_METADATA) {
+		ctl->max_chunk_size = ctl->max_stripe_size;
+	} else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
+		ctl->max_chunk_size = 2 * ctl->max_stripe_size;
+		ctl->devs_max = min_t(int, ctl->devs_max,
+				      BTRFS_MAX_DEVS_SYS_CHUNK);
+	}
+
+	/* We don't want a chunk larger than 10% of writable space */
+	limit = max(round_down(div_factor(fs_devices->total_rw_bytes, 1),
+			       zone_size),
+		    min_chunk_size);
+	ctl->max_chunk_size = min(limit, ctl->max_chunk_size);
+	ctl->dev_extent_min = zone_size * ctl->dev_stripes;
+}
+
 static void init_alloc_chunk_ctl(struct btrfs_fs_devices *fs_devices,
 				 struct alloc_chunk_ctl *ctl)
 {
@@ -4927,6 +5019,9 @@ static void init_alloc_chunk_ctl(struct btrfs_fs_devices *fs_devices,
 	case BTRFS_CHUNK_ALLOC_REGULAR:
 		init_alloc_chunk_ctl_policy_regular(fs_devices, ctl);
 		break;
+	case BTRFS_CHUNK_ALLOC_ZONED:
+		init_alloc_chunk_ctl_policy_zoned(fs_devices, ctl);
+		break;
 	default:
 		BUG();
 	}
@@ -5053,6 +5148,40 @@ static int decide_stripe_size_regular(struct alloc_chunk_ctl *ctl,
 	return 0;
 }
 
+static int decide_stripe_size_zoned(struct alloc_chunk_ctl *ctl,
+				    struct btrfs_device_info *devices_info)
+{
+	u64 zone_size = devices_info[0].dev->zone_info->zone_size;
+	/* number of stripes that count for block group size */
+	int data_stripes;
+
+	/*
+	 * It should hold because:
+	 *    dev_extent_min == dev_extent_want == zone_size * dev_stripes
+	 */
+	ASSERT(devices_info[ctl->ndevs - 1].max_avail == ctl->dev_extent_min);
+
+	ctl->stripe_size = zone_size;
+	ctl->num_stripes = ctl->ndevs * ctl->dev_stripes;
+	data_stripes = (ctl->num_stripes - ctl->nparity) / ctl->ncopies;
+
+	/*
+	 * stripe_size is fixed in ZONED. Reduce ndevs instead.
+	 */
+	if (ctl->stripe_size * data_stripes > ctl->max_chunk_size) {
+		ctl->ndevs = div_u64(div_u64(ctl->max_chunk_size * ctl->ncopies,
+					     ctl->stripe_size) + ctl->nparity,
+				     ctl->dev_stripes);
+		ctl->num_stripes = ctl->ndevs * ctl->dev_stripes;
+		data_stripes = (ctl->num_stripes - ctl->nparity) / ctl->ncopies;
+		ASSERT(ctl->stripe_size * data_stripes <= ctl->max_chunk_size);
+	}
+
+	ctl->chunk_size = ctl->stripe_size * data_stripes;
+
+	return 0;
+}
+
 static int decide_stripe_size(struct btrfs_fs_devices *fs_devices,
 			      struct alloc_chunk_ctl *ctl,
 			      struct btrfs_device_info *devices_info)
@@ -5080,6 +5209,8 @@ static int decide_stripe_size(struct btrfs_fs_devices *fs_devices,
 	switch (fs_devices->chunk_alloc_policy) {
 	case BTRFS_CHUNK_ALLOC_REGULAR:
 		return decide_stripe_size_regular(ctl, devices_info);
+	case BTRFS_CHUNK_ALLOC_ZONED:
+		return decide_stripe_size_zoned(ctl, devices_info);
 	default:
 		BUG();
 	}
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 9c07b97a2260..0249aca668fb 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -213,6 +213,7 @@ BTRFS_DEVICE_GETSET_FUNCS(bytes_used);
 
 enum btrfs_chunk_allocation_policy {
 	BTRFS_CHUNK_ALLOC_REGULAR,
+	BTRFS_CHUNK_ALLOC_ZONED,
 };
 
 struct btrfs_fs_devices {
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index d5487cba203b..4411d786597a 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -1,11 +1,13 @@
 // SPDX-License-Identifier: GPL-2.0
 
+#include <linux/bitops.h>
 #include <linux/slab.h>
 #include <linux/blkdev.h>
 #include "ctree.h"
 #include "volumes.h"
 #include "zoned.h"
 #include "rcu-string.h"
+#include "disk-io.h"
 
 /* Maximum number of zones to report per blkdev_report_zones() call */
 #define BTRFS_REPORT_NR_ZONES   4096
@@ -328,6 +330,7 @@ int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
 
 	fs_info->zone_size = zone_size;
 	fs_info->max_zone_append_size = max_zone_append_size;
+	fs_info->fs_devices->chunk_alloc_policy = BTRFS_CHUNK_ALLOC_ZONED;
 
 	btrfs_info(fs_info, "ZONED mode enabled, zone size %llu B",
 		   fs_info->zone_size);
@@ -607,3 +610,126 @@ int btrfs_reset_sb_log_zones(struct block_device *bdev, int mirror)
 				sb_zone << zone_sectors_shift, zone_sectors * 2,
 				GFP_NOFS);
 }
+
+/*
+ * btrfs_check_allocatable_zones - find allocatable zones within give region
+ * @device:	the device to allocate a region
+ * @hole_start: the position of the hole to allocate the region
+ * @num_bytes:	the size of wanted region
+ * @hole_size:	the size of hole
+ *
+ * Allocatable region should not contain any superblock locations.
+ */
+u64 btrfs_find_allocatable_zones(struct btrfs_device *device, u64 hole_start,
+				 u64 hole_end, u64 num_bytes)
+{
+	struct btrfs_zoned_device_info *zinfo = device->zone_info;
+	u8 shift = zinfo->zone_size_shift;
+	u64 nzones = num_bytes >> shift;
+	u64 pos = hole_start;
+	u64 begin, end;
+	u64 sb_pos;
+	bool have_sb;
+	int i;
+
+	ASSERT(IS_ALIGNED(hole_start, zinfo->zone_size));
+	ASSERT(IS_ALIGNED(num_bytes, zinfo->zone_size));
+
+	while (pos < hole_end) {
+		begin = pos >> shift;
+		end = begin + nzones;
+
+		if (end > zinfo->nr_zones)
+			return hole_end;
+
+		/* check if zones in the region are all empty */
+		if (btrfs_dev_is_sequential(device, pos) &&
+		    find_next_zero_bit(zinfo->empty_zones, end, begin) != end) {
+			pos += zinfo->zone_size;
+			continue;
+		}
+
+		have_sb = false;
+		for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
+			sb_pos = sb_zone_number(zinfo->zone_size, i);
+			if (!(end < sb_pos || sb_pos + 1 < begin)) {
+				have_sb = true;
+				pos = (sb_pos + 2) << shift;
+				break;
+			}
+		}
+		if (!have_sb)
+			break;
+	}
+
+	return pos;
+}
+
+int btrfs_reset_device_zone(struct btrfs_device *device, u64 physical,
+			    u64 length, u64 *bytes)
+{
+	int ret;
+
+	*bytes = 0;
+	ret = blkdev_zone_mgmt(device->bdev, REQ_OP_ZONE_RESET,
+			       physical >> SECTOR_SHIFT, length >> SECTOR_SHIFT,
+			       GFP_NOFS);
+	if (ret)
+		return ret;
+
+	*bytes = length;
+	while (length) {
+		btrfs_dev_set_zone_empty(device, physical);
+		physical += device->zone_info->zone_size;
+		length -= device->zone_info->zone_size;
+	}
+
+	return 0;
+}
+
+int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size)
+{
+	struct btrfs_zoned_device_info *zinfo = device->zone_info;
+	u8 shift = zinfo->zone_size_shift;
+	unsigned long begin = start >> shift;
+	unsigned long end = (start + size) >> shift;
+	u64 pos;
+	int ret;
+
+	ASSERT(IS_ALIGNED(start, zinfo->zone_size));
+	ASSERT(IS_ALIGNED(size, zinfo->zone_size));
+
+	if (end > zinfo->nr_zones)
+		return -ERANGE;
+
+	/* all the zones are conventional */
+	if (find_next_bit(zinfo->seq_zones, begin, end) == end)
+		return 0;
+
+	/* all the zones are sequential and empty */
+	if (find_next_zero_bit(zinfo->seq_zones, begin, end) == end &&
+	    find_next_zero_bit(zinfo->empty_zones, begin, end) == end)
+		return 0;
+
+	for (pos = start; pos < start + size; pos += zinfo->zone_size) {
+		u64 reset_bytes;
+
+		if (!btrfs_dev_is_sequential(device, pos) ||
+		    btrfs_dev_is_empty_zone(device, pos))
+			continue;
+
+		/* free regions should be empty */
+		btrfs_warn_in_rcu(
+			device->fs_info,
+			"resetting device %s zone %llu for allocation",
+			rcu_str_deref(device->name), pos >> shift);
+		WARN_ON_ONCE(1);
+
+		ret = btrfs_reset_device_zone(device, pos, zinfo->zone_size,
+					      &reset_bytes);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h
index 447c4e5ffcbb..24dd0c9561f9 100644
--- a/fs/btrfs/zoned.h
+++ b/fs/btrfs/zoned.h
@@ -34,6 +34,11 @@ int btrfs_sb_log_location(struct btrfs_device *device, int mirror, int rw,
 			  u64 *bytenr_ret);
 void btrfs_advance_sb_log(struct btrfs_device *device, int mirror);
 int btrfs_reset_sb_log_zones(struct block_device *bdev, int mirror);
+u64 btrfs_find_allocatable_zones(struct btrfs_device *device, u64 hole_start,
+				 u64 hole_end, u64 num_bytes);
+int btrfs_reset_device_zone(struct btrfs_device *device, u64 physical,
+			    u64 length, u64 *bytes);
+int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size);
 #else /* CONFIG_BLK_DEV_ZONED */
 static inline int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
 				     struct blk_zone *zone)
@@ -77,6 +82,23 @@ static inline int btrfs_reset_sb_log_zones(struct block_device *bdev,
 {
 	return 0;
 }
+static inline u64 btrfs_find_allocatable_zones(struct btrfs_device *device,
+					       u64 hole_start, u64 hole_end,
+					       u64 num_bytes)
+{
+	return hole_start;
+}
+static inline int btrfs_reset_device_zone(struct btrfs_device *device,
+					  u64 physical, u64 length, u64 *bytes)
+{
+	*bytes = 0;
+	return 0;
+}
+static inline int btrfs_ensure_empty_zones(struct btrfs_device *device,
+					   u64 start, u64 size)
+{
+	return 0;
+}
 #endif
 
 static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos)
@@ -155,4 +177,12 @@ static inline bool btrfs_check_super_location(struct btrfs_device *device,
 	       !btrfs_dev_is_sequential(device, pos);
 }
 
+static inline u64 btrfs_zone_align(struct btrfs_device *device, u64 pos)
+{
+	if (!device->zone_info)
+		return pos;
+
+	return ALIGN(pos, device->zone_info->zone_size);
+}
+
 #endif
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 13/41] btrfs: verify device extent is aligned to zone
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (10 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 12/41] btrfs: implement zoned chunk allocator Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-02 20:14     ` Josef Bacik
  2020-10-30 13:51   ` [PATCH v9 14/41] btrfs: load zone's alloction offset Naohiro Aota
                     ` (28 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

Add a check in verify_one_dev_extent() to check if a device extent on a
zoned block device is aligned to the respective zone boundary.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/volumes.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 78c62ef02e6f..9e69222086ae 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -7778,6 +7778,20 @@ static int verify_one_dev_extent(struct btrfs_fs_info *fs_info,
 		ret = -EUCLEAN;
 		goto out;
 	}
+
+	if (dev->zone_info) {
+		u64 zone_size = dev->zone_info->zone_size;
+
+		if (!IS_ALIGNED(physical_offset, zone_size) ||
+		    !IS_ALIGNED(physical_len, zone_size)) {
+			btrfs_err(fs_info,
+"dev extent devid %llu physical offset %llu len %llu is not aligned to device zone",
+				  devid, physical_offset, physical_len);
+			ret = -EUCLEAN;
+			goto out;
+		}
+	}
+
 out:
 	free_extent_map(em);
 	return ret;
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 14/41] btrfs: load zone's alloction offset
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (11 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 13/41] btrfs: verify device extent is aligned to zone Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-02 20:25     ` Josef Bacik
  2020-11-03 13:28     ` David Sterba
  2020-10-30 13:51   ` [PATCH v9 15/41] btrfs: emulate write pointer for conventional zones Naohiro Aota
                     ` (27 subsequent siblings)
  40 siblings, 2 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

Zoned btrfs must allocate blocks at the zones' write pointer. The device's
write pointer position can be mapped to a logical address within a block
group. This commit adds "alloc_offset" to track the logical address.

This logical address is populated in btrfs_load_block-group_zone_info()
from write pointers of corresponding zones.

For now, zoned btrfs only support the SINGLE profile. Supporting non-SINGLE
profile with zone append writing is not trivial. For example, in the DUP
profile, we send a zone append writing IO to two zones on a device. The
device reply with written LBAs for the IOs. If the offsets of the returned
addresses from the beginning of the zone are different, then it results in
different logical addresses.

We need fine-grained logical to physical mapping to support such separated
physical address issue. Since it should require additional metadata type,
disable non-SINGLE profiles for now.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/block-group.c |  15 ++++
 fs/btrfs/block-group.h |   6 ++
 fs/btrfs/zoned.c       | 153 +++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/zoned.h       |   6 ++
 4 files changed, 180 insertions(+)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index e989c66aa764..920b2708c7f2 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -15,6 +15,7 @@
 #include "delalloc-space.h"
 #include "discard.h"
 #include "raid56.h"
+#include "zoned.h"
 
 /*
  * Return target flags in extended format or 0 if restripe for this chunk_type
@@ -1935,6 +1936,13 @@ static int read_one_block_group(struct btrfs_fs_info *info,
 			goto error;
 	}
 
+	ret = btrfs_load_block_group_zone_info(cache);
+	if (ret) {
+		btrfs_err(info, "failed to load zone info of bg %llu",
+			  cache->start);
+		goto error;
+	}
+
 	/*
 	 * We need to exclude the super stripes now so that the space info has
 	 * super bytes accounted for, otherwise we'll think we have more space
@@ -2161,6 +2169,13 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans, u64 bytes_used,
 	cache->last_byte_to_unpin = (u64)-1;
 	cache->cached = BTRFS_CACHE_FINISHED;
 	cache->needs_free_space = 1;
+
+	ret = btrfs_load_block_group_zone_info(cache);
+	if (ret) {
+		btrfs_put_block_group(cache);
+		return ret;
+	}
+
 	ret = exclude_super_stripes(cache);
 	if (ret) {
 		/* We may have excluded something, so call this just in case */
diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index adfd7583a17b..14e3043c9ce7 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -183,6 +183,12 @@ struct btrfs_block_group {
 
 	/* Record locked full stripes for RAID5/6 block group */
 	struct btrfs_full_stripe_locks_tree full_stripe_locks_root;
+
+	/*
+	 * Allocation offset for the block group to implement sequential
+	 * allocation. This is used only with ZONED mode enabled.
+	 */
+	u64 alloc_offset;
 };
 
 static inline u64 btrfs_block_group_end(struct btrfs_block_group *block_group)
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index 4411d786597a..0aa821893a51 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -3,14 +3,20 @@
 #include <linux/bitops.h>
 #include <linux/slab.h>
 #include <linux/blkdev.h>
+#include <linux/sched/mm.h>
 #include "ctree.h"
 #include "volumes.h"
 #include "zoned.h"
 #include "rcu-string.h"
 #include "disk-io.h"
+#include "block-group.h"
 
 /* Maximum number of zones to report per blkdev_report_zones() call */
 #define BTRFS_REPORT_NR_ZONES   4096
+/* Invalid allocation pointer value for missing devices */
+#define WP_MISSING_DEV ((u64)-1)
+/* Pseudo write pointer value for conventional zone */
+#define WP_CONVENTIONAL ((u64)-2)
 
 static int copy_zone_info_cb(struct blk_zone *zone, unsigned int idx,
 			     void *data)
@@ -733,3 +739,150 @@ int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size)
 
 	return 0;
 }
+
+int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache)
+{
+	struct btrfs_fs_info *fs_info = cache->fs_info;
+	struct extent_map_tree *em_tree = &fs_info->mapping_tree;
+	struct extent_map *em;
+	struct map_lookup *map;
+	struct btrfs_device *device;
+	u64 logical = cache->start;
+	u64 length = cache->length;
+	u64 physical = 0;
+	int ret;
+	int i;
+	unsigned int nofs_flag;
+	u64 *alloc_offsets = NULL;
+	u32 num_sequential = 0, num_conventional = 0;
+
+	if (!btrfs_is_zoned(fs_info))
+		return 0;
+
+	/* Sanity check */
+	if (!IS_ALIGNED(length, fs_info->zone_size)) {
+		btrfs_err(fs_info, "unaligned block group at %llu + %llu",
+			  logical, length);
+		return -EIO;
+	}
+
+	/* Get the chunk mapping */
+	read_lock(&em_tree->lock);
+	em = lookup_extent_mapping(em_tree, logical, length);
+	read_unlock(&em_tree->lock);
+
+	if (!em)
+		return -EINVAL;
+
+	map = em->map_lookup;
+
+	/*
+	 * Get the zone type: if the group is mapped to a non-sequential zone,
+	 * there is no need for the allocation offset (fit allocation is OK).
+	 */
+	alloc_offsets = kcalloc(map->num_stripes, sizeof(*alloc_offsets),
+				GFP_NOFS);
+	if (!alloc_offsets) {
+		free_extent_map(em);
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < map->num_stripes; i++) {
+		bool is_sequential;
+		struct blk_zone zone;
+
+		device = map->stripes[i].dev;
+		physical = map->stripes[i].physical;
+
+		if (device->bdev == NULL) {
+			alloc_offsets[i] = WP_MISSING_DEV;
+			continue;
+		}
+
+		is_sequential = btrfs_dev_is_sequential(device, physical);
+		if (is_sequential)
+			num_sequential++;
+		else
+			num_conventional++;
+
+		if (!is_sequential) {
+			alloc_offsets[i] = WP_CONVENTIONAL;
+			continue;
+		}
+
+		/*
+		 * This zone will be used for allocation, so mark this
+		 * zone non-empty.
+		 */
+		btrfs_dev_clear_zone_empty(device, physical);
+
+		/*
+		 * The group is mapped to a sequential zone. Get the zone write
+		 * pointer to determine the allocation offset within the zone.
+		 */
+		WARN_ON(!IS_ALIGNED(physical, fs_info->zone_size));
+		nofs_flag = memalloc_nofs_save();
+		ret = btrfs_get_dev_zone(device, physical, &zone);
+		memalloc_nofs_restore(nofs_flag);
+		if (ret == -EIO || ret == -EOPNOTSUPP) {
+			ret = 0;
+			alloc_offsets[i] = WP_MISSING_DEV;
+			continue;
+		} else if (ret) {
+			goto out;
+		}
+
+		switch (zone.cond) {
+		case BLK_ZONE_COND_OFFLINE:
+		case BLK_ZONE_COND_READONLY:
+			btrfs_err(fs_info, "Offline/readonly zone %llu",
+				  physical >> device->zone_info->zone_size_shift);
+			alloc_offsets[i] = WP_MISSING_DEV;
+			break;
+		case BLK_ZONE_COND_EMPTY:
+			alloc_offsets[i] = 0;
+			break;
+		case BLK_ZONE_COND_FULL:
+			alloc_offsets[i] = fs_info->zone_size;
+			break;
+		default:
+			/* Partially used zone */
+			alloc_offsets[i] =
+				((zone.wp - zone.start) << SECTOR_SHIFT);
+			break;
+		}
+	}
+
+	if (num_conventional > 0) {
+		/*
+		 * Since conventional zones does not have write pointer, we
+		 * cannot determine alloc_offset from the pointer
+		 */
+		ret = -EINVAL;
+		goto out;
+	}
+
+	switch (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
+	case 0: /* single */
+		cache->alloc_offset = alloc_offsets[0];
+		break;
+	case BTRFS_BLOCK_GROUP_DUP:
+	case BTRFS_BLOCK_GROUP_RAID1:
+	case BTRFS_BLOCK_GROUP_RAID0:
+	case BTRFS_BLOCK_GROUP_RAID10:
+	case BTRFS_BLOCK_GROUP_RAID5:
+	case BTRFS_BLOCK_GROUP_RAID6:
+		/* non-SINGLE profiles are not supported yet */
+	default:
+		btrfs_err(fs_info, "Unsupported profile on ZONED %s",
+			  btrfs_bg_type_to_raid_name(map->type));
+		ret = -EINVAL;
+		goto out;
+	}
+
+out:
+	kfree(alloc_offsets);
+	free_extent_map(em);
+
+	return ret;
+}
diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h
index 24dd0c9561f9..90ed43a25595 100644
--- a/fs/btrfs/zoned.h
+++ b/fs/btrfs/zoned.h
@@ -39,6 +39,7 @@ u64 btrfs_find_allocatable_zones(struct btrfs_device *device, u64 hole_start,
 int btrfs_reset_device_zone(struct btrfs_device *device, u64 physical,
 			    u64 length, u64 *bytes);
 int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size);
+int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache);
 #else /* CONFIG_BLK_DEV_ZONED */
 static inline int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
 				     struct blk_zone *zone)
@@ -99,6 +100,11 @@ static inline int btrfs_ensure_empty_zones(struct btrfs_device *device,
 {
 	return 0;
 }
+static inline int btrfs_load_block_group_zone_info(
+	struct btrfs_block_group *cache)
+{
+	return 0;
+}
 #endif
 
 static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos)
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 15/41] btrfs: emulate write pointer for conventional zones
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (12 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 14/41] btrfs: load zone's alloction offset Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-02 20:37     ` Josef Bacik
  2020-11-03 13:32     ` David Sterba
  2020-10-30 13:51   ` [PATCH v9 16/41] btrfs: track unusable bytes for zones Naohiro Aota
                     ` (26 subsequent siblings)
  40 siblings, 2 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

Conventional zones do not have a write pointer, so we cannot use it to
determine the allocation offset if a block group contains a conventional
zone.

But instead, we can consider the end of the last allocated extent in the
block group as an allocation offset.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/zoned.c | 119 ++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 113 insertions(+), 6 deletions(-)

diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index 0aa821893a51..8f58d0853cc3 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -740,6 +740,104 @@ int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size)
 	return 0;
 }
 
+static int emulate_write_pointer(struct btrfs_block_group *cache,
+				 u64 *offset_ret)
+{
+	struct btrfs_fs_info *fs_info = cache->fs_info;
+	struct btrfs_root *root = fs_info->extent_root;
+	struct btrfs_path *path;
+	struct extent_buffer *leaf;
+	struct btrfs_key search_key;
+	struct btrfs_key found_key;
+	int slot;
+	int ret;
+	u64 length;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	search_key.objectid = cache->start + cache->length;
+	search_key.type = 0;
+	search_key.offset = 0;
+
+	ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
+	if (ret < 0)
+		goto out;
+	ASSERT(ret != 0);
+	slot = path->slots[0];
+	leaf = path->nodes[0];
+	ASSERT(slot != 0);
+	slot--;
+	btrfs_item_key_to_cpu(leaf, &found_key, slot);
+
+	if (found_key.objectid < cache->start) {
+		*offset_ret = 0;
+	} else if (found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
+		struct btrfs_key extent_item_key;
+
+		if (found_key.objectid != cache->start) {
+			ret = -EUCLEAN;
+			goto out;
+		}
+
+		length = 0;
+
+		/* metadata may have METADATA_ITEM_KEY */
+		if (slot == 0) {
+			btrfs_set_path_blocking(path);
+			ret = btrfs_prev_leaf(root, path);
+			if (ret < 0)
+				goto out;
+			if (ret == 0) {
+				slot = btrfs_header_nritems(leaf) - 1;
+				btrfs_item_key_to_cpu(leaf, &extent_item_key,
+						      slot);
+			}
+		} else {
+			btrfs_item_key_to_cpu(leaf, &extent_item_key, slot - 1);
+			ret = 0;
+		}
+
+		if (ret == 0 &&
+		    extent_item_key.objectid == cache->start) {
+			if (extent_item_key.type == BTRFS_METADATA_ITEM_KEY)
+				length = fs_info->nodesize;
+			else if (extent_item_key.type == BTRFS_EXTENT_ITEM_KEY)
+				length = extent_item_key.offset;
+			else {
+				ret = -EUCLEAN;
+				goto out;
+			}
+		}
+
+		*offset_ret = length;
+	} else if (found_key.type == BTRFS_EXTENT_ITEM_KEY ||
+		   found_key.type == BTRFS_METADATA_ITEM_KEY) {
+
+		if (found_key.type == BTRFS_EXTENT_ITEM_KEY)
+			length = found_key.offset;
+		else
+			length = fs_info->nodesize;
+
+		if (!(found_key.objectid >= cache->start &&
+		       found_key.objectid + length <=
+		       cache->start + cache->length)) {
+			ret = -EUCLEAN;
+			goto out;
+		}
+		*offset_ret = found_key.objectid + length - cache->start;
+	} else {
+		ret = -EUCLEAN;
+		goto out;
+	}
+	ret = 0;
+
+out:
+	btrfs_free_path(path);
+	return ret;
+}
+
 int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache)
 {
 	struct btrfs_fs_info *fs_info = cache->fs_info;
@@ -754,6 +852,7 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache)
 	int i;
 	unsigned int nofs_flag;
 	u64 *alloc_offsets = NULL;
+	u64 emulated_offset = 0;
 	u32 num_sequential = 0, num_conventional = 0;
 
 	if (!btrfs_is_zoned(fs_info))
@@ -854,12 +953,12 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache)
 	}
 
 	if (num_conventional > 0) {
-		/*
-		 * Since conventional zones does not have write pointer, we
-		 * cannot determine alloc_offset from the pointer
-		 */
-		ret = -EINVAL;
-		goto out;
+		ret = emulate_write_pointer(cache, &emulated_offset);
+		if (ret || map->num_stripes == num_conventional) {
+			if (!ret)
+				cache->alloc_offset = emulated_offset;
+			goto out;
+		}
 	}
 
 	switch (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
@@ -881,6 +980,14 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache)
 	}
 
 out:
+	/* an extent is allocated after the write pointer */
+	if (num_conventional && emulated_offset > cache->alloc_offset) {
+		btrfs_err(fs_info,
+			  "got wrong write pointer in BG %llu: %llu > %llu",
+			  logical, emulated_offset, cache->alloc_offset);
+		ret = -EIO;
+	}
+
 	kfree(alloc_offsets);
 	free_extent_map(em);
 
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 16/41] btrfs: track unusable bytes for zones
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (13 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 15/41] btrfs: emulate write pointer for conventional zones Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 14:25     ` Josef Bacik
  2020-10-30 13:51   ` [PATCH v9 17/41] btrfs: do sequential extent allocation in ZONED mode Naohiro Aota
                     ` (25 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

In zoned btrfs a region that was once written then freed is not usable
until we reset the underlying zone. So we need to distinguish such
unusable space from usable free space.

Therefore we need to introduce the "zone_unusable" field  to the block
group structure, and "bytes_zone_unusable" to the space_info structure to
track the unusable space.

Pinned bytes are always reclaimed to the unusable space. But, when an
allocated region is returned before using e.g., the block group becomes
read-only between allocation time and reservation time, we can safely
return the region to the block group. For the situation, this commit
introduces "btrfs_add_free_space_unused". This behaves the same as
btrfs_add_free_space() on regular btrfs. On zoned btrfs, it rewinds the
allocation offset.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/block-group.c      | 19 +++++++++-----
 fs/btrfs/block-group.h      |  1 +
 fs/btrfs/extent-tree.c      | 15 ++++++++---
 fs/btrfs/free-space-cache.c | 52 +++++++++++++++++++++++++++++++++++++
 fs/btrfs/free-space-cache.h |  4 +++
 fs/btrfs/space-info.c       | 13 ++++++----
 fs/btrfs/space-info.h       |  4 ++-
 fs/btrfs/sysfs.c            |  2 ++
 fs/btrfs/zoned.c            | 22 ++++++++++++++++
 fs/btrfs/zoned.h            |  2 ++
 10 files changed, 118 insertions(+), 16 deletions(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index 920b2708c7f2..c34bd2dbdf82 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -1080,12 +1080,15 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 		WARN_ON(block_group->space_info->total_bytes
 			< block_group->length);
 		WARN_ON(block_group->space_info->bytes_readonly
-			< block_group->length);
+			< block_group->length - block_group->zone_unusable);
+		WARN_ON(block_group->space_info->bytes_zone_unusable
+			< block_group->zone_unusable);
 		WARN_ON(block_group->space_info->disk_total
 			< block_group->length * factor);
 	}
 	block_group->space_info->total_bytes -= block_group->length;
-	block_group->space_info->bytes_readonly -= block_group->length;
+	block_group->space_info->bytes_readonly -=
+		(block_group->length - block_group->zone_unusable);
 	block_group->space_info->disk_total -= block_group->length * factor;
 
 	spin_unlock(&block_group->space_info->lock);
@@ -1229,7 +1232,7 @@ static int inc_block_group_ro(struct btrfs_block_group *cache, int force)
 	}
 
 	num_bytes = cache->length - cache->reserved - cache->pinned -
-		    cache->bytes_super - cache->used;
+		    cache->bytes_super - cache->zone_unusable - cache->used;
 
 	/*
 	 * Data never overcommits, even in mixed mode, so do just the straight
@@ -1973,6 +1976,8 @@ static int read_one_block_group(struct btrfs_fs_info *info,
 		btrfs_free_excluded_extents(cache);
 	}
 
+	btrfs_calc_zone_unusable(cache);
+
 	ret = btrfs_add_block_group_cache(info, cache);
 	if (ret) {
 		btrfs_remove_free_space_cache(cache);
@@ -1980,7 +1985,8 @@ static int read_one_block_group(struct btrfs_fs_info *info,
 	}
 	trace_btrfs_add_block_group(info, cache, 0);
 	btrfs_update_space_info(info, cache->flags, cache->length,
-				cache->used, cache->bytes_super, &space_info);
+				cache->used, cache->bytes_super,
+				cache->zone_unusable, &space_info);
 
 	cache->space_info = space_info;
 
@@ -2217,7 +2223,7 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans, u64 bytes_used,
 	 */
 	trace_btrfs_add_block_group(fs_info, cache, 1);
 	btrfs_update_space_info(fs_info, cache->flags, size, bytes_used,
-				cache->bytes_super, &cache->space_info);
+				cache->bytes_super, 0, &cache->space_info);
 	btrfs_update_global_block_rsv(fs_info);
 
 	link_block_group(cache);
@@ -2325,7 +2331,8 @@ void btrfs_dec_block_group_ro(struct btrfs_block_group *cache)
 	spin_lock(&cache->lock);
 	if (!--cache->ro) {
 		num_bytes = cache->length - cache->reserved -
-			    cache->pinned - cache->bytes_super - cache->used;
+			    cache->pinned - cache->bytes_super -
+			    cache->zone_unusable - cache->used;
 		sinfo->bytes_readonly -= num_bytes;
 		list_del_init(&cache->ro_list);
 	}
diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index 14e3043c9ce7..5be47f4bfea7 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -189,6 +189,7 @@ struct btrfs_block_group {
 	 * allocation. This is used only with ZONED mode enabled.
 	 */
 	u64 alloc_offset;
+	u64 zone_unusable;
 };
 
 static inline u64 btrfs_block_group_end(struct btrfs_block_group *block_group)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 3b21fee13e77..fad53c702d8a 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -34,6 +34,7 @@
 #include "block-group.h"
 #include "discard.h"
 #include "rcu-string.h"
+#include "zoned.h"
 
 #undef SCRAMBLE_DELAYED_REFS
 
@@ -2807,9 +2808,11 @@ static int unpin_extent_range(struct btrfs_fs_info *fs_info,
 			cache = btrfs_lookup_block_group(fs_info, start);
 			BUG_ON(!cache); /* Logic error */
 
-			cluster = fetch_cluster_info(fs_info,
-						     cache->space_info,
-						     &empty_cluster);
+			if (!btrfs_is_zoned(fs_info))
+				cluster = fetch_cluster_info(fs_info,
+							     cache->space_info,
+							     &empty_cluster);
+
 			empty_cluster <<= 1;
 		}
 
@@ -2846,7 +2849,11 @@ static int unpin_extent_range(struct btrfs_fs_info *fs_info,
 		space_info->max_extent_size = 0;
 		percpu_counter_add_batch(&space_info->total_bytes_pinned,
 			    -len, BTRFS_TOTAL_BYTES_PINNED_BATCH);
-		if (cache->ro) {
+		if (btrfs_is_zoned(fs_info)) {
+			/* need reset before reusing in zoned Block Group */
+			space_info->bytes_zone_unusable += len;
+			readonly = true;
+		} else if (cache->ro) {
 			space_info->bytes_readonly += len;
 			readonly = true;
 		}
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index af0013d3df63..cfa466319166 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -2467,6 +2467,8 @@ int __btrfs_add_free_space(struct btrfs_fs_info *fs_info,
 	int ret = 0;
 	u64 filter_bytes = bytes;
 
+	ASSERT(!btrfs_is_zoned(fs_info));
+
 	info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
 	if (!info)
 		return -ENOMEM;
@@ -2524,11 +2526,44 @@ int __btrfs_add_free_space(struct btrfs_fs_info *fs_info,
 	return ret;
 }
 
+int __btrfs_add_free_space_zoned(struct btrfs_block_group *block_group,
+				 u64 bytenr, u64 size, bool used)
+{
+	struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+	u64 offset = bytenr - block_group->start;
+	u64 to_free, to_unusable;
+
+	spin_lock(&ctl->tree_lock);
+	if (!used)
+		to_free = size;
+	else if (offset >= block_group->alloc_offset)
+		to_free = size;
+	else if (offset + size <= block_group->alloc_offset)
+		to_free = 0;
+	else
+		to_free = offset + size - block_group->alloc_offset;
+	to_unusable = size - to_free;
+
+	ctl->free_space += to_free;
+	block_group->zone_unusable += to_unusable;
+	spin_unlock(&ctl->tree_lock);
+	if (!used) {
+		spin_lock(&block_group->lock);
+		block_group->alloc_offset -= size;
+		spin_unlock(&block_group->lock);
+	}
+	return 0;
+}
+
 int btrfs_add_free_space(struct btrfs_block_group *block_group,
 			 u64 bytenr, u64 size)
 {
 	enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
 
+	if (btrfs_is_zoned(block_group->fs_info))
+		return __btrfs_add_free_space_zoned(block_group, bytenr, size,
+						    true);
+
 	if (btrfs_test_opt(block_group->fs_info, DISCARD_SYNC))
 		trim_state = BTRFS_TRIM_STATE_TRIMMED;
 
@@ -2537,6 +2572,16 @@ int btrfs_add_free_space(struct btrfs_block_group *block_group,
 				      bytenr, size, trim_state);
 }
 
+int btrfs_add_free_space_unused(struct btrfs_block_group *block_group,
+				u64 bytenr, u64 size)
+{
+	if (btrfs_is_zoned(block_group->fs_info))
+		return __btrfs_add_free_space_zoned(block_group, bytenr, size,
+						    false);
+
+	return btrfs_add_free_space(block_group, bytenr, size);
+}
+
 /*
  * This is a subtle distinction because when adding free space back in general,
  * we want it to be added as untrimmed for async. But in the case where we add
@@ -2547,6 +2592,10 @@ int btrfs_add_free_space_async_trimmed(struct btrfs_block_group *block_group,
 {
 	enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
 
+	if (btrfs_is_zoned(block_group->fs_info))
+		return __btrfs_add_free_space_zoned(block_group, bytenr, size,
+						    true);
+
 	if (btrfs_test_opt(block_group->fs_info, DISCARD_SYNC) ||
 	    btrfs_test_opt(block_group->fs_info, DISCARD_ASYNC))
 		trim_state = BTRFS_TRIM_STATE_TRIMMED;
@@ -2564,6 +2613,9 @@ int btrfs_remove_free_space(struct btrfs_block_group *block_group,
 	int ret;
 	bool re_search = false;
 
+	if (btrfs_is_zoned(block_group->fs_info))
+		return 0;
+
 	spin_lock(&ctl->tree_lock);
 
 again:
diff --git a/fs/btrfs/free-space-cache.h b/fs/btrfs/free-space-cache.h
index e3d5e0ad8f8e..7081216257a8 100644
--- a/fs/btrfs/free-space-cache.h
+++ b/fs/btrfs/free-space-cache.h
@@ -114,8 +114,12 @@ int __btrfs_add_free_space(struct btrfs_fs_info *fs_info,
 			   struct btrfs_free_space_ctl *ctl,
 			   u64 bytenr, u64 size,
 			   enum btrfs_trim_state trim_state);
+int __btrfs_add_free_space_zoned(struct btrfs_block_group *block_group,
+				 u64 bytenr, u64 size, bool used);
 int btrfs_add_free_space(struct btrfs_block_group *block_group,
 			 u64 bytenr, u64 size);
+int btrfs_add_free_space_unused(struct btrfs_block_group *block_group,
+				u64 bytenr, u64 size);
 int btrfs_add_free_space_async_trimmed(struct btrfs_block_group *block_group,
 				       u64 bytenr, u64 size);
 int btrfs_remove_free_space(struct btrfs_block_group *block_group,
diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c
index 64099565ab8f..bbbf3c1412a4 100644
--- a/fs/btrfs/space-info.c
+++ b/fs/btrfs/space-info.c
@@ -163,6 +163,7 @@ u64 __pure btrfs_space_info_used(struct btrfs_space_info *s_info,
 	ASSERT(s_info);
 	return s_info->bytes_used + s_info->bytes_reserved +
 		s_info->bytes_pinned + s_info->bytes_readonly +
+		s_info->bytes_zone_unusable +
 		(may_use_included ? s_info->bytes_may_use : 0);
 }
 
@@ -257,7 +258,7 @@ int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
 
 void btrfs_update_space_info(struct btrfs_fs_info *info, u64 flags,
 			     u64 total_bytes, u64 bytes_used,
-			     u64 bytes_readonly,
+			     u64 bytes_readonly, u64 bytes_zone_unusable,
 			     struct btrfs_space_info **space_info)
 {
 	struct btrfs_space_info *found;
@@ -273,6 +274,7 @@ void btrfs_update_space_info(struct btrfs_fs_info *info, u64 flags,
 	found->bytes_used += bytes_used;
 	found->disk_used += bytes_used * factor;
 	found->bytes_readonly += bytes_readonly;
+	found->bytes_zone_unusable += bytes_zone_unusable;
 	if (total_bytes > 0)
 		found->full = 0;
 	btrfs_try_granting_tickets(info, found);
@@ -422,10 +424,10 @@ static void __btrfs_dump_space_info(struct btrfs_fs_info *fs_info,
 		   info->total_bytes - btrfs_space_info_used(info, true),
 		   info->full ? "" : "not ");
 	btrfs_info(fs_info,
-		"space_info total=%llu, used=%llu, pinned=%llu, reserved=%llu, may_use=%llu, readonly=%llu",
+		"space_info total=%llu, used=%llu, pinned=%llu, reserved=%llu, may_use=%llu, readonly=%llu zone_unusable=%llu",
 		info->total_bytes, info->bytes_used, info->bytes_pinned,
 		info->bytes_reserved, info->bytes_may_use,
-		info->bytes_readonly);
+		info->bytes_readonly, info->bytes_zone_unusable);
 
 	DUMP_BLOCK_RSV(fs_info, global_block_rsv);
 	DUMP_BLOCK_RSV(fs_info, trans_block_rsv);
@@ -454,9 +456,10 @@ void btrfs_dump_space_info(struct btrfs_fs_info *fs_info,
 	list_for_each_entry(cache, &info->block_groups[index], list) {
 		spin_lock(&cache->lock);
 		btrfs_info(fs_info,
-			"block group %llu has %llu bytes, %llu used %llu pinned %llu reserved %s",
+			"block group %llu has %llu bytes, %llu used %llu pinned %llu reserved %llu zone_unusable %s",
 			cache->start, cache->length, cache->used, cache->pinned,
-			cache->reserved, cache->ro ? "[readonly]" : "");
+			cache->reserved, cache->zone_unusable,
+			cache->ro ? "[readonly]" : "");
 		spin_unlock(&cache->lock);
 		btrfs_dump_free_space(cache, bytes);
 	}
diff --git a/fs/btrfs/space-info.h b/fs/btrfs/space-info.h
index 5646393b928c..ee003ffba956 100644
--- a/fs/btrfs/space-info.h
+++ b/fs/btrfs/space-info.h
@@ -17,6 +17,8 @@ struct btrfs_space_info {
 	u64 bytes_may_use;	/* number of bytes that may be used for
 				   delalloc/allocations */
 	u64 bytes_readonly;	/* total bytes that are read only */
+	u64 bytes_zone_unusable;	/* total bytes that are unusable until
+					   resetting the device zone */
 
 	u64 max_extent_size;	/* This will hold the maximum extent size of
 				   the space info if we had an ENOSPC in the
@@ -119,7 +121,7 @@ DECLARE_SPACE_INFO_UPDATE(bytes_pinned, "pinned");
 int btrfs_init_space_info(struct btrfs_fs_info *fs_info);
 void btrfs_update_space_info(struct btrfs_fs_info *info, u64 flags,
 			     u64 total_bytes, u64 bytes_used,
-			     u64 bytes_readonly,
+			     u64 bytes_readonly, u64 bytes_zone_unusable,
 			     struct btrfs_space_info **space_info);
 struct btrfs_space_info *btrfs_find_space_info(struct btrfs_fs_info *info,
 					       u64 flags);
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 828006020bbd..ea679803da9b 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -635,6 +635,7 @@ SPACE_INFO_ATTR(bytes_pinned);
 SPACE_INFO_ATTR(bytes_reserved);
 SPACE_INFO_ATTR(bytes_may_use);
 SPACE_INFO_ATTR(bytes_readonly);
+SPACE_INFO_ATTR(bytes_zone_unusable);
 SPACE_INFO_ATTR(disk_used);
 SPACE_INFO_ATTR(disk_total);
 BTRFS_ATTR(space_info, total_bytes_pinned,
@@ -648,6 +649,7 @@ static struct attribute *space_info_attrs[] = {
 	BTRFS_ATTR_PTR(space_info, bytes_reserved),
 	BTRFS_ATTR_PTR(space_info, bytes_may_use),
 	BTRFS_ATTR_PTR(space_info, bytes_readonly),
+	BTRFS_ATTR_PTR(space_info, bytes_zone_unusable),
 	BTRFS_ATTR_PTR(space_info, disk_used),
 	BTRFS_ATTR_PTR(space_info, disk_total),
 	BTRFS_ATTR_PTR(space_info, total_bytes_pinned),
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index 8f58d0853cc3..d94a2c363a47 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -993,3 +993,25 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache)
 
 	return ret;
 }
+
+void btrfs_calc_zone_unusable(struct btrfs_block_group *cache)
+{
+	u64 unusable, free;
+
+	if (!btrfs_is_zoned(cache->fs_info))
+		return;
+
+	WARN_ON(cache->bytes_super != 0);
+	unusable = cache->alloc_offset - cache->used;
+	free = cache->length - cache->alloc_offset;
+	/* we only need ->free_space in ALLOC_SEQ BGs */
+	cache->last_byte_to_unpin = (u64)-1;
+	cache->cached = BTRFS_CACHE_FINISHED;
+	cache->free_space_ctl->free_space = free;
+	cache->zone_unusable = unusable;
+	/*
+	 * Should not have any excluded extents. Just
+	 * in case, though.
+	 */
+	btrfs_free_excluded_extents(cache);
+}
diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h
index 90ed43a25595..42b1a4217c6b 100644
--- a/fs/btrfs/zoned.h
+++ b/fs/btrfs/zoned.h
@@ -40,6 +40,7 @@ int btrfs_reset_device_zone(struct btrfs_device *device, u64 physical,
 			    u64 length, u64 *bytes);
 int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size);
 int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache);
+void btrfs_calc_zone_unusable(struct btrfs_block_group *cache);
 #else /* CONFIG_BLK_DEV_ZONED */
 static inline int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
 				     struct blk_zone *zone)
@@ -105,6 +106,7 @@ static inline int btrfs_load_block_group_zone_info(
 {
 	return 0;
 }
+static inline void btrfs_calc_zone_unusable(struct btrfs_block_group *cache) { }
 #endif
 
 static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos)
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 17/41] btrfs: do sequential extent allocation in ZONED mode
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (14 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 16/41] btrfs: track unusable bytes for zones Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 14:28     ` Josef Bacik
  2020-10-30 13:51   ` [PATCH v9 18/41] btrfs: reset zones of unused block groups Naohiro Aota
                     ` (24 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

This commit implements a sequential extent allocator for the ZONED mode.
This allocator just needs to check if there is enough space in the block
group. Therefor the allocator never manages bitmaps or clusters. Also add
ASSERTs to the corresponding functions.

Actually, with zone append writing, it is unnecessary to track the
allocation offset. It only needs to check space availability. But, by
tracking the offset and returning the offset as an allocated region, we can
skip modification of ordered extents and checksum information when there is
no IO reordering.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/block-group.c      |  4 ++
 fs/btrfs/extent-tree.c      | 85 ++++++++++++++++++++++++++++++++++---
 fs/btrfs/free-space-cache.c |  6 +++
 3 files changed, 89 insertions(+), 6 deletions(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index c34bd2dbdf82..d67f9cabe5c1 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -683,6 +683,10 @@ int btrfs_cache_block_group(struct btrfs_block_group *cache, int load_cache_only
 	struct btrfs_caching_control *caching_ctl;
 	int ret = 0;
 
+	/* Allocator for ZONED btrfs do not use the cache at all */
+	if (btrfs_is_zoned(fs_info))
+		return 0;
+
 	caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS);
 	if (!caching_ctl)
 		return -ENOMEM;
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index fad53c702d8a..5e6b4d1712f2 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3562,6 +3562,7 @@ btrfs_release_block_group(struct btrfs_block_group *cache,
 
 enum btrfs_extent_allocation_policy {
 	BTRFS_EXTENT_ALLOC_CLUSTERED,
+	BTRFS_EXTENT_ALLOC_ZONED,
 };
 
 /*
@@ -3814,6 +3815,58 @@ static int do_allocation_clustered(struct btrfs_block_group *block_group,
 	return find_free_extent_unclustered(block_group, ffe_ctl);
 }
 
+/*
+ * Simple allocator for sequential only block group. It only allows
+ * sequential allocation. No need to play with trees. This function
+ * also reserve the bytes as in btrfs_add_reserved_bytes.
+ */
+static int do_allocation_zoned(struct btrfs_block_group *block_group,
+			       struct find_free_extent_ctl *ffe_ctl,
+			       struct btrfs_block_group **bg_ret)
+{
+	struct btrfs_space_info *space_info = block_group->space_info;
+	struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+	u64 start = block_group->start;
+	u64 num_bytes = ffe_ctl->num_bytes;
+	u64 avail;
+	int ret = 0;
+
+	ASSERT(btrfs_is_zoned(block_group->fs_info));
+
+	spin_lock(&space_info->lock);
+	spin_lock(&block_group->lock);
+
+	if (block_group->ro) {
+		ret = 1;
+		goto out;
+	}
+
+	avail = block_group->length - block_group->alloc_offset;
+	if (avail < num_bytes) {
+		ffe_ctl->max_extent_size = avail;
+		ret = 1;
+		goto out;
+	}
+
+	ffe_ctl->found_offset = start + block_group->alloc_offset;
+	block_group->alloc_offset += num_bytes;
+	spin_lock(&ctl->tree_lock);
+	ctl->free_space -= num_bytes;
+	spin_unlock(&ctl->tree_lock);
+
+	/*
+	 * We do not check if found_offset is aligned to stripesize. The
+	 * address is anyway rewritten when using zone append writing.
+	 */
+
+	ffe_ctl->search_start = ffe_ctl->found_offset;
+
+out:
+	spin_unlock(&block_group->lock);
+	spin_unlock(&space_info->lock);
+	return ret;
+}
+
 static int do_allocation(struct btrfs_block_group *block_group,
 			 struct find_free_extent_ctl *ffe_ctl,
 			 struct btrfs_block_group **bg_ret)
@@ -3821,6 +3874,8 @@ static int do_allocation(struct btrfs_block_group *block_group,
 	switch (ffe_ctl->policy) {
 	case BTRFS_EXTENT_ALLOC_CLUSTERED:
 		return do_allocation_clustered(block_group, ffe_ctl, bg_ret);
+	case BTRFS_EXTENT_ALLOC_ZONED:
+		return do_allocation_zoned(block_group, ffe_ctl, bg_ret);
 	default:
 		BUG();
 	}
@@ -3835,6 +3890,9 @@ static void release_block_group(struct btrfs_block_group *block_group,
 		ffe_ctl->retry_clustered = false;
 		ffe_ctl->retry_unclustered = false;
 		break;
+	case BTRFS_EXTENT_ALLOC_ZONED:
+		/* nothing to do */
+		break;
 	default:
 		BUG();
 	}
@@ -3863,6 +3921,9 @@ static void found_extent(struct find_free_extent_ctl *ffe_ctl,
 	case BTRFS_EXTENT_ALLOC_CLUSTERED:
 		found_extent_clustered(ffe_ctl, ins);
 		break;
+	case BTRFS_EXTENT_ALLOC_ZONED:
+		/* nothing to do */
+		break;
 	default:
 		BUG();
 	}
@@ -3878,6 +3939,9 @@ static int chunk_allocation_failed(struct find_free_extent_ctl *ffe_ctl)
 		 */
 		ffe_ctl->loop = LOOP_NO_EMPTY_SIZE;
 		return 0;
+	case BTRFS_EXTENT_ALLOC_ZONED:
+		/* give up here */
+		return -ENOSPC;
 	default:
 		BUG();
 	}
@@ -4046,6 +4110,9 @@ static int prepare_allocation(struct btrfs_fs_info *fs_info,
 	case BTRFS_EXTENT_ALLOC_CLUSTERED:
 		return prepare_allocation_clustered(fs_info, ffe_ctl,
 						    space_info, ins);
+	case BTRFS_EXTENT_ALLOC_ZONED:
+		/* nothing to do */
+		return 0;
 	default:
 		BUG();
 	}
@@ -4109,6 +4176,9 @@ static noinline int find_free_extent(struct btrfs_root *root,
 	ffe_ctl.last_ptr = NULL;
 	ffe_ctl.use_cluster = true;
 
+	if (btrfs_is_zoned(fs_info))
+		ffe_ctl.policy = BTRFS_EXTENT_ALLOC_ZONED;
+
 	ins->type = BTRFS_EXTENT_ITEM_KEY;
 	ins->objectid = 0;
 	ins->offset = 0;
@@ -4251,20 +4321,23 @@ static noinline int find_free_extent(struct btrfs_root *root,
 		/* move on to the next group */
 		if (ffe_ctl.search_start + num_bytes >
 		    block_group->start + block_group->length) {
-			btrfs_add_free_space(block_group, ffe_ctl.found_offset,
-					     num_bytes);
+			btrfs_add_free_space_unused(block_group,
+						    ffe_ctl.found_offset,
+						    num_bytes);
 			goto loop;
 		}
 
 		if (ffe_ctl.found_offset < ffe_ctl.search_start)
-			btrfs_add_free_space(block_group, ffe_ctl.found_offset,
-				ffe_ctl.search_start - ffe_ctl.found_offset);
+			btrfs_add_free_space_unused(block_group,
+						    ffe_ctl.found_offset,
+						    ffe_ctl.search_start - ffe_ctl.found_offset);
 
 		ret = btrfs_add_reserved_bytes(block_group, ram_bytes,
 				num_bytes, delalloc);
 		if (ret == -EAGAIN) {
-			btrfs_add_free_space(block_group, ffe_ctl.found_offset,
-					     num_bytes);
+			btrfs_add_free_space_unused(block_group,
+						    ffe_ctl.found_offset,
+						    num_bytes);
 			goto loop;
 		}
 		btrfs_inc_block_group_reservations(block_group);
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index cfa466319166..7ad046d33c7e 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -2903,6 +2903,8 @@ u64 btrfs_find_space_for_alloc(struct btrfs_block_group *block_group,
 	u64 align_gap_len = 0;
 	enum btrfs_trim_state align_gap_trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
 
+	ASSERT(!btrfs_is_zoned(block_group->fs_info));
+
 	spin_lock(&ctl->tree_lock);
 	entry = find_free_space(ctl, &offset, &bytes_search,
 				block_group->full_stripe_len, max_extent_size);
@@ -3034,6 +3036,8 @@ u64 btrfs_alloc_from_cluster(struct btrfs_block_group *block_group,
 	struct rb_node *node;
 	u64 ret = 0;
 
+	ASSERT(!btrfs_is_zoned(block_group->fs_info));
+
 	spin_lock(&cluster->lock);
 	if (bytes > cluster->max_size)
 		goto out;
@@ -3810,6 +3814,8 @@ int btrfs_trim_block_group(struct btrfs_block_group *block_group,
 	int ret;
 	u64 rem = 0;
 
+	ASSERT(!btrfs_is_zoned(block_group->fs_info));
+
 	*trimmed = 0;
 
 	spin_lock(&block_group->lock);
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 18/41] btrfs: reset zones of unused block groups
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (15 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 17/41] btrfs: do sequential extent allocation in ZONED mode Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 14:34     ` Josef Bacik
  2020-10-30 13:51   ` [PATCH v9 19/41] btrfs: redirty released extent buffers in ZONED mode Naohiro Aota
                     ` (23 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

For an ZONED volume, a block group maps to a zone of the device. For
deleted unused block groups, the zone of the block group can be reset to
rewind the zone write pointer at the start of the zone.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/block-group.c |  8 ++++++--
 fs/btrfs/extent-tree.c | 17 ++++++++++++-----
 fs/btrfs/zoned.h       | 16 ++++++++++++++++
 3 files changed, 34 insertions(+), 7 deletions(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index d67f9cabe5c1..82d556368c85 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -1468,8 +1468,12 @@ void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
 		if (!async_trim_enabled && btrfs_test_opt(fs_info, DISCARD_ASYNC))
 			goto flip_async;
 
-		/* DISCARD can flip during remount */
-		trimming = btrfs_test_opt(fs_info, DISCARD_SYNC);
+		/*
+		 * DISCARD can flip during remount. In ZONED mode, we need
+		 * to reset sequential required zones.
+		 */
+		trimming = btrfs_test_opt(fs_info, DISCARD_SYNC) ||
+				btrfs_is_zoned(fs_info);
 
 		/* Implicit trim during transaction commit. */
 		if (trimming)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 5e6b4d1712f2..c134746d7417 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1331,6 +1331,9 @@ int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
 
 		stripe = bbio->stripes;
 		for (i = 0; i < bbio->num_stripes; i++, stripe++) {
+			struct btrfs_device *dev = stripe->dev;
+			u64 physical = stripe->physical;
+			u64 length = stripe->length;
 			u64 bytes;
 			struct request_queue *req_q;
 
@@ -1338,14 +1341,18 @@ int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
 				ASSERT(btrfs_test_opt(fs_info, DEGRADED));
 				continue;
 			}
+
 			req_q = bdev_get_queue(stripe->dev->bdev);
-			if (!blk_queue_discard(req_q))
+			/* zone reset in ZONED mode */
+			if (btrfs_can_zone_reset(dev, physical, length))
+				ret = btrfs_reset_device_zone(dev, physical,
+							      length, &bytes);
+			else if (blk_queue_discard(req_q))
+				ret = btrfs_issue_discard(dev->bdev, physical,
+							  length, &bytes);
+			else
 				continue;
 
-			ret = btrfs_issue_discard(stripe->dev->bdev,
-						  stripe->physical,
-						  stripe->length,
-						  &bytes);
 			if (!ret) {
 				discarded_bytes += bytes;
 			} else if (ret != -EOPNOTSUPP) {
diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h
index 42b1a4217c6b..d13bc6d70ea4 100644
--- a/fs/btrfs/zoned.h
+++ b/fs/btrfs/zoned.h
@@ -193,4 +193,20 @@ static inline u64 btrfs_zone_align(struct btrfs_device *device, u64 pos)
 	return ALIGN(pos, device->zone_info->zone_size);
 }
 
+static inline bool btrfs_can_zone_reset(struct btrfs_device *device,
+					u64 physical, u64 length)
+{
+	u64 zone_size;
+
+	if (!btrfs_dev_is_sequential(device, physical))
+		return false;
+
+	zone_size = device->zone_info->zone_size;
+	if (!IS_ALIGNED(physical, zone_size) ||
+	    !IS_ALIGNED(length, zone_size))
+		return false;
+
+	return true;
+}
+
 #endif
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 19/41] btrfs: redirty released extent buffers in ZONED mode
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (16 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 18/41] btrfs: reset zones of unused block groups Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 14:41     ` Josef Bacik
  2020-10-30 13:51   ` [PATCH v9 20/41] btrfs: extract page adding function Naohiro Aota
                     ` (22 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

Tree manipulating operations like merging nodes often release
once-allocated tree nodes. Btrfs cleans such nodes so that pages in the
node are not uselessly written out. On ZONED volumes, however, such
optimization blocks the following IOs as the cancellation of the write out
of the freed blocks breaks the sequential write sequence expected by the
device.

This patch introduces a list of clean and unwritten extent buffers that
have been released in a transaction. Btrfs redirty the buffer so that
btree_write_cache_pages() can send proper bios to the devices.

Besides it clears the entire content of the extent buffer not to confuse
raw block scanners e.g. btrfsck. By clearing the content,
csum_dirty_buffer() complains about bytenr mismatch, so avoid the checking
and checksum using newly introduced buffer flag EXTENT_BUFFER_NO_CHECK.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/disk-io.c     |  8 ++++++++
 fs/btrfs/extent-tree.c | 12 +++++++++++-
 fs/btrfs/extent_io.c   |  4 ++++
 fs/btrfs/extent_io.h   |  2 ++
 fs/btrfs/transaction.c | 10 ++++++++++
 fs/btrfs/transaction.h |  3 +++
 fs/btrfs/tree-log.c    |  6 ++++++
 fs/btrfs/zoned.c       | 37 +++++++++++++++++++++++++++++++++++++
 fs/btrfs/zoned.h       |  6 ++++++
 9 files changed, 87 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index fd8b970ee92c..9750b4e6d538 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -462,6 +462,12 @@ static int csum_dirty_buffer(struct btrfs_fs_info *fs_info, struct page *page)
 		return 0;
 
 	found_start = btrfs_header_bytenr(eb);
+
+	if (test_bit(EXTENT_BUFFER_NO_CHECK, &eb->bflags)) {
+		WARN_ON(found_start != 0);
+		return 0;
+	}
+
 	/*
 	 * Please do not consolidate these warnings into a single if.
 	 * It is useful to know what went wrong.
@@ -4616,6 +4622,8 @@ void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans,
 				     EXTENT_DIRTY);
 	btrfs_destroy_pinned_extent(fs_info, &cur_trans->pinned_extents);
 
+	btrfs_free_redirty_list(cur_trans);
+
 	cur_trans->state =TRANS_STATE_COMPLETED;
 	wake_up(&cur_trans->commit_wait);
 }
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index c134746d7417..57454ef4c91e 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3421,8 +3421,10 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
 
 		if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
 			ret = check_ref_cleanup(trans, buf->start);
-			if (!ret)
+			if (!ret) {
+				btrfs_redirty_list_add(trans->transaction, buf);
 				goto out;
+			}
 		}
 
 		pin = 0;
@@ -3434,6 +3436,13 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
 			goto out;
 		}
 
+		if (btrfs_is_zoned(fs_info)) {
+			btrfs_redirty_list_add(trans->transaction, buf);
+			pin_down_extent(trans, cache, buf->start, buf->len, 1);
+			btrfs_put_block_group(cache);
+			goto out;
+		}
+
 		WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags));
 
 		btrfs_add_free_space(cache, buf->start, buf->len);
@@ -4770,6 +4779,7 @@ btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 	__btrfs_tree_lock(buf, nest);
 	btrfs_clean_tree_block(buf);
 	clear_bit(EXTENT_BUFFER_STALE, &buf->bflags);
+	clear_bit(EXTENT_BUFFER_NO_CHECK, &buf->bflags);
 
 	btrfs_set_lock_blocking_write(buf);
 	set_extent_buffer_uptodate(buf);
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 60f5f68d892d..e91c504fe973 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -24,6 +24,7 @@
 #include "rcu-string.h"
 #include "backref.h"
 #include "disk-io.h"
+#include "zoned.h"
 
 static struct kmem_cache *extent_state_cache;
 static struct kmem_cache *extent_buffer_cache;
@@ -4959,6 +4960,7 @@ __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start,
 
 	btrfs_leak_debug_add(&fs_info->eb_leak_lock, &eb->leak_list,
 			     &fs_info->allocated_ebs);
+	INIT_LIST_HEAD(&eb->release_list);
 
 	spin_lock_init(&eb->refs_lock);
 	atomic_set(&eb->refs, 1);
@@ -5744,6 +5746,8 @@ void write_extent_buffer(const struct extent_buffer *eb, const void *srcv,
 	char *src = (char *)srcv;
 	unsigned long i = start >> PAGE_SHIFT;
 
+	WARN_ON(test_bit(EXTENT_BUFFER_NO_CHECK, &eb->bflags));
+
 	if (check_eb_range(eb, start, len))
 		return;
 
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index f39d02e7f7ef..5f2ccfd0205e 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -30,6 +30,7 @@ enum {
 	EXTENT_BUFFER_IN_TREE,
 	/* write IO error */
 	EXTENT_BUFFER_WRITE_ERR,
+	EXTENT_BUFFER_NO_CHECK,
 };
 
 /* these are flags for __process_pages_contig */
@@ -107,6 +108,7 @@ struct extent_buffer {
 	 */
 	wait_queue_head_t read_lock_wq;
 	struct page *pages[INLINE_EXTENT_BUFFER_PAGES];
+	struct list_head release_list;
 #ifdef CONFIG_BTRFS_DEBUG
 	int spinning_writers;
 	atomic_t spinning_readers;
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 52ada47aff50..5c561cdcce42 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -22,6 +22,7 @@
 #include "qgroup.h"
 #include "block-group.h"
 #include "space-info.h"
+#include "zoned.h"
 
 #define BTRFS_ROOT_TRANS_TAG 0
 
@@ -336,6 +337,8 @@ static noinline int join_transaction(struct btrfs_fs_info *fs_info,
 	spin_lock_init(&cur_trans->dirty_bgs_lock);
 	INIT_LIST_HEAD(&cur_trans->deleted_bgs);
 	spin_lock_init(&cur_trans->dropped_roots_lock);
+	INIT_LIST_HEAD(&cur_trans->releasing_ebs);
+	spin_lock_init(&cur_trans->releasing_ebs_lock);
 	list_add_tail(&cur_trans->list, &fs_info->trans_list);
 	extent_io_tree_init(fs_info, &cur_trans->dirty_pages,
 			IO_TREE_TRANS_DIRTY_PAGES, fs_info->btree_inode);
@@ -2345,6 +2348,13 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
 		goto scrub_continue;
 	}
 
+	/*
+	 * At this point, we should have written the all tree blocks
+	 * allocated in this transaction. So it's now safe to free the
+	 * redirtyied extent buffers.
+	 */
+	btrfs_free_redirty_list(cur_trans);
+
 	ret = write_all_supers(fs_info, 0);
 	/*
 	 * the super is written, we can safely allow the tree-loggers
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 858d9153a1cd..380e0aaa15b3 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -92,6 +92,9 @@ struct btrfs_transaction {
 	 */
 	atomic_t pending_ordered;
 	wait_queue_head_t pending_wait;
+
+	spinlock_t releasing_ebs_lock;
+	struct list_head releasing_ebs;
 };
 
 #define __TRANS_FREEZABLE	(1U << 0)
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 56cbc1706b6f..5f585cf57383 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -20,6 +20,7 @@
 #include "inode-map.h"
 #include "block-group.h"
 #include "space-info.h"
+#include "zoned.h"
 
 /* magic values for the inode_only field in btrfs_log_inode:
  *
@@ -2742,6 +2743,8 @@ static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
 						free_extent_buffer(next);
 						return ret;
 					}
+					btrfs_redirty_list_add(
+						trans->transaction, next);
 				} else {
 					if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags))
 						clear_extent_buffer_dirty(next);
@@ -3277,6 +3280,9 @@ static void free_log_tree(struct btrfs_trans_handle *trans,
 	clear_extent_bits(&log->dirty_log_pages, 0, (u64)-1,
 			  EXTENT_DIRTY | EXTENT_NEW | EXTENT_NEED_WAIT);
 	extent_io_tree_release(&log->log_csum_range);
+
+	if (trans && log->node)
+		btrfs_redirty_list_add(trans->transaction, log->node);
 	btrfs_put_root(log);
 }
 
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index d94a2c363a47..b45ca33282d9 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -10,6 +10,7 @@
 #include "rcu-string.h"
 #include "disk-io.h"
 #include "block-group.h"
+#include "transaction.h"
 
 /* Maximum number of zones to report per blkdev_report_zones() call */
 #define BTRFS_REPORT_NR_ZONES   4096
@@ -1015,3 +1016,39 @@ void btrfs_calc_zone_unusable(struct btrfs_block_group *cache)
 	 */
 	btrfs_free_excluded_extents(cache);
 }
+
+void btrfs_redirty_list_add(struct btrfs_transaction *trans,
+			    struct extent_buffer *eb)
+{
+	struct btrfs_fs_info *fs_info = eb->fs_info;
+
+	if (!btrfs_is_zoned(fs_info) ||
+	    btrfs_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN) ||
+	    !list_empty(&eb->release_list))
+		return;
+
+	set_extent_buffer_dirty(eb);
+	set_extent_bits_nowait(&trans->dirty_pages, eb->start,
+			       eb->start + eb->len - 1, EXTENT_DIRTY);
+	memzero_extent_buffer(eb, 0, eb->len);
+	set_bit(EXTENT_BUFFER_NO_CHECK, &eb->bflags);
+
+	spin_lock(&trans->releasing_ebs_lock);
+	list_add_tail(&eb->release_list, &trans->releasing_ebs);
+	spin_unlock(&trans->releasing_ebs_lock);
+	atomic_inc(&eb->refs);
+}
+
+void btrfs_free_redirty_list(struct btrfs_transaction *trans)
+{
+	spin_lock(&trans->releasing_ebs_lock);
+	while (!list_empty(&trans->releasing_ebs)) {
+		struct extent_buffer *eb;
+
+		eb = list_first_entry(&trans->releasing_ebs,
+				      struct extent_buffer, release_list);
+		list_del_init(&eb->release_list);
+		free_extent_buffer(eb);
+	}
+	spin_unlock(&trans->releasing_ebs_lock);
+}
diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h
index d13bc6d70ea4..845623932fa5 100644
--- a/fs/btrfs/zoned.h
+++ b/fs/btrfs/zoned.h
@@ -41,6 +41,9 @@ int btrfs_reset_device_zone(struct btrfs_device *device, u64 physical,
 int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size);
 int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache);
 void btrfs_calc_zone_unusable(struct btrfs_block_group *cache);
+void btrfs_redirty_list_add(struct btrfs_transaction *trans,
+			    struct extent_buffer *eb);
+void btrfs_free_redirty_list(struct btrfs_transaction *trans);
 #else /* CONFIG_BLK_DEV_ZONED */
 static inline int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
 				     struct blk_zone *zone)
@@ -107,6 +110,9 @@ static inline int btrfs_load_block_group_zone_info(
 	return 0;
 }
 static inline void btrfs_calc_zone_unusable(struct btrfs_block_group *cache) { }
+static inline void btrfs_redirty_list_add(struct btrfs_transaction *trans,
+					  struct extent_buffer *eb) { }
+static inline void btrfs_free_redirty_list(struct btrfs_transaction *trans) { }
 #endif
 
 static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos)
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 20/41] btrfs: extract page adding function
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (17 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 19/41] btrfs: redirty released extent buffers in ZONED mode Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 14:45     ` Josef Bacik
  2020-10-30 13:51   ` [PATCH v9 21/41] btrfs: use bio_add_zone_append_page for zoned btrfs Naohiro Aota
                     ` (21 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

This commit extract page adding to bio part from submit_extent_page(). The
page is added only when bio_flags are the same, contiguous and the added
page fits in the same stripe as pages in the bio.

Condition checkings are reordered to allow early return to avoid possibly
heavy btrfs_bio_fits_in_stripe() calling.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/extent_io.c | 55 ++++++++++++++++++++++++++++++++------------
 1 file changed, 40 insertions(+), 15 deletions(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index e91c504fe973..17285048fb5a 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3012,6 +3012,43 @@ struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size)
 	return bio;
 }
 
+/**
+ * btrfs_bio_add_page	-	attempt to add a page to bio
+ * @bio:	destination bio
+ * @page:	page to add to the bio
+ * @logical:	offset of the new bio or to check whether we are adding
+ *              a contiguous page to the previous one
+ * @pg_offset:	starting offset in the page
+ * @size:	portion of page that we want to write
+ * @prev_bio_flags:  flags of previous bio to see if we can merge the current one
+ * @bio_flags:	flags of the current bio to see if we can merge them
+ *
+ * Attempt to add a page to bio considering stripe alignment etc. Return
+ * true if successfully page added. Otherwise, return false.
+ */
+bool btrfs_bio_add_page(struct bio *bio, struct page *page, u64 logical,
+			unsigned int size, unsigned int pg_offset,
+			unsigned long prev_bio_flags, unsigned long bio_flags)
+{
+	sector_t sector = logical >> SECTOR_SHIFT;
+	bool contig;
+
+	if (prev_bio_flags != bio_flags)
+		return false;
+
+	if (prev_bio_flags & EXTENT_BIO_COMPRESSED)
+		contig = bio->bi_iter.bi_sector == sector;
+	else
+		contig = bio_end_sector(bio) == sector;
+	if (!contig)
+		return false;
+
+	if (btrfs_bio_fits_in_stripe(page, size, bio, bio_flags))
+		return false;
+
+	return bio_add_page(bio, page, size, pg_offset) == size;
+}
+
 /*
  * @opf:	bio REQ_OP_* and REQ_* flags as one value
  * @wbc:	optional writeback control for io accounting
@@ -3040,27 +3077,15 @@ static int submit_extent_page(unsigned int opf,
 	int ret = 0;
 	struct bio *bio;
 	size_t page_size = min_t(size_t, size, PAGE_SIZE);
-	sector_t sector = offset >> 9;
 	struct extent_io_tree *tree = &BTRFS_I(page->mapping->host)->io_tree;
 
 	ASSERT(bio_ret);
 
 	if (*bio_ret) {
-		bool contig;
-		bool can_merge = true;
-
 		bio = *bio_ret;
-		if (prev_bio_flags & EXTENT_BIO_COMPRESSED)
-			contig = bio->bi_iter.bi_sector == sector;
-		else
-			contig = bio_end_sector(bio) == sector;
-
-		if (btrfs_bio_fits_in_stripe(page, page_size, bio, bio_flags))
-			can_merge = false;
-
-		if (prev_bio_flags != bio_flags || !contig || !can_merge ||
-		    force_bio_submit ||
-		    bio_add_page(bio, page, page_size, pg_offset) < page_size) {
+		if (force_bio_submit ||
+		    !btrfs_bio_add_page(bio, page, offset, page_size, pg_offset,
+					prev_bio_flags, bio_flags)) {
 			ret = submit_one_bio(bio, mirror_num, prev_bio_flags);
 			if (ret < 0) {
 				*bio_ret = NULL;
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 21/41] btrfs: use bio_add_zone_append_page for zoned btrfs
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (18 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 20/41] btrfs: extract page adding function Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 14:55     ` Josef Bacik
  2020-10-30 13:51   ` [PATCH v9 22/41] btrfs: handle REQ_OP_ZONE_APPEND as writing Naohiro Aota
                     ` (20 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

Zoned device has its own hardware restrictions e.g. max_zone_append_size
when using REQ_OP_ZONE_APPEND. To follow the restrictions, use
bio_add_zone_append_page() instead of bio_add_page(). We need target device
to use bio_add_zone_append_page(), so this commit reads the chunk
information to memoize the target device to btrfs_io_bio(bio)->device.

Currently, zoned btrfs only supports SINGLE profile. In the feature,
btrfs_io_bio can hold extent_map and check the restrictions for all the
devices the bio will be mapped.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/extent_io.c | 37 ++++++++++++++++++++++++++++++++++---
 1 file changed, 34 insertions(+), 3 deletions(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 17285048fb5a..764257eb658f 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3032,6 +3032,7 @@ bool btrfs_bio_add_page(struct bio *bio, struct page *page, u64 logical,
 {
 	sector_t sector = logical >> SECTOR_SHIFT;
 	bool contig;
+	int ret;
 
 	if (prev_bio_flags != bio_flags)
 		return false;
@@ -3046,7 +3047,19 @@ bool btrfs_bio_add_page(struct bio *bio, struct page *page, u64 logical,
 	if (btrfs_bio_fits_in_stripe(page, size, bio, bio_flags))
 		return false;
 
-	return bio_add_page(bio, page, size, pg_offset) == size;
+	if (bio_op(bio) == REQ_OP_ZONE_APPEND) {
+		struct bio orig_bio;
+
+		memset(&orig_bio, 0, sizeof(orig_bio));
+		bio_copy_dev(&orig_bio, bio);
+		bio_set_dev(bio, btrfs_io_bio(bio)->device->bdev);
+		ret = bio_add_zone_append_page(bio, page, size, pg_offset);
+		bio_copy_dev(bio, &orig_bio);
+	} else {
+		ret = bio_add_page(bio, page, size, pg_offset);
+	}
+
+	return ret == size;
 }
 
 /*
@@ -3077,7 +3090,9 @@ static int submit_extent_page(unsigned int opf,
 	int ret = 0;
 	struct bio *bio;
 	size_t page_size = min_t(size_t, size, PAGE_SIZE);
-	struct extent_io_tree *tree = &BTRFS_I(page->mapping->host)->io_tree;
+	struct btrfs_inode *inode = BTRFS_I(page->mapping->host);
+	struct extent_io_tree *tree = &inode->io_tree;
+	struct btrfs_fs_info *fs_info = inode->root->fs_info;
 
 	ASSERT(bio_ret);
 
@@ -3108,11 +3123,27 @@ static int submit_extent_page(unsigned int opf,
 	if (wbc) {
 		struct block_device *bdev;
 
-		bdev = BTRFS_I(page->mapping->host)->root->fs_info->fs_devices->latest_bdev;
+		bdev = fs_info->fs_devices->latest_bdev;
 		bio_set_dev(bio, bdev);
 		wbc_init_bio(wbc, bio);
 		wbc_account_cgroup_owner(wbc, page, page_size);
 	}
+	if (btrfs_is_zoned(fs_info) &&
+	    bio_op(bio) == REQ_OP_ZONE_APPEND) {
+		struct extent_map *em;
+		struct map_lookup *map;
+
+		em = btrfs_get_chunk_map(fs_info, offset, page_size);
+		if (IS_ERR(em))
+			return PTR_ERR(em);
+
+		map = em->map_lookup;
+		/* only support SINGLE profile for now */
+		ASSERT(map->num_stripes == 1);
+		btrfs_io_bio(bio)->device = map->stripes[0].dev;
+
+		free_extent_map(em);
+	}
 
 	*bio_ret = bio;
 
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 22/41] btrfs: handle REQ_OP_ZONE_APPEND as writing
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (19 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 21/41] btrfs: use bio_add_zone_append_page for zoned btrfs Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 14:57     ` Josef Bacik
  2020-10-30 13:51   ` [PATCH v9 23/41] btrfs: split ordered extent when bio is sent Naohiro Aota
                     ` (19 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

ZONED btrfs uses REQ_OP_ZONE_APPEND bios for writing to actual devices. Let
btrfs_end_bio() and btrfs_op be aware of it.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/disk-io.c |  4 ++--
 fs/btrfs/inode.c   | 10 +++++-----
 fs/btrfs/volumes.c |  8 ++++----
 fs/btrfs/volumes.h |  1 +
 4 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 9750b4e6d538..778716e223ff 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -652,7 +652,7 @@ static void end_workqueue_bio(struct bio *bio)
 	fs_info = end_io_wq->info;
 	end_io_wq->status = bio->bi_status;
 
-	if (bio_op(bio) == REQ_OP_WRITE) {
+	if (btrfs_op(bio) == BTRFS_MAP_WRITE) {
 		if (end_io_wq->metadata == BTRFS_WQ_ENDIO_METADATA)
 			wq = fs_info->endio_meta_write_workers;
 		else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_FREE_SPACE)
@@ -827,7 +827,7 @@ blk_status_t btrfs_submit_metadata_bio(struct inode *inode, struct bio *bio,
 	int async = check_async_write(fs_info, BTRFS_I(inode));
 	blk_status_t ret;
 
-	if (bio_op(bio) != REQ_OP_WRITE) {
+	if (btrfs_op(bio) != BTRFS_MAP_WRITE) {
 		/*
 		 * called for a read, do the setup so that checksum validation
 		 * can happen in the async kernel threads
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 936c3137c646..591ca539e444 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2192,7 +2192,7 @@ blk_status_t btrfs_submit_data_bio(struct inode *inode, struct bio *bio,
 	if (btrfs_is_free_space_inode(BTRFS_I(inode)))
 		metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
 
-	if (bio_op(bio) != REQ_OP_WRITE) {
+	if (btrfs_op(bio) != BTRFS_MAP_WRITE) {
 		ret = btrfs_bio_wq_end_io(fs_info, bio, metadata);
 		if (ret)
 			goto out;
@@ -7526,7 +7526,7 @@ static void btrfs_dio_private_put(struct btrfs_dio_private *dip)
 	if (!refcount_dec_and_test(&dip->refs))
 		return;
 
-	if (bio_op(dip->dio_bio) == REQ_OP_WRITE) {
+	if (btrfs_op(dip->dio_bio) == BTRFS_MAP_WRITE) {
 		__endio_write_update_ordered(BTRFS_I(dip->inode),
 					     dip->logical_offset,
 					     dip->bytes,
@@ -7695,7 +7695,7 @@ static inline blk_status_t btrfs_submit_dio_bio(struct bio *bio,
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_dio_private *dip = bio->bi_private;
-	bool write = bio_op(bio) == REQ_OP_WRITE;
+	bool write = btrfs_op(bio) == BTRFS_MAP_WRITE;
 	blk_status_t ret;
 
 	/* Check btrfs_submit_bio_hook() for rules about async submit. */
@@ -7746,7 +7746,7 @@ static struct btrfs_dio_private *btrfs_create_dio_private(struct bio *dio_bio,
 							  struct inode *inode,
 							  loff_t file_offset)
 {
-	const bool write = (bio_op(dio_bio) == REQ_OP_WRITE);
+	const bool write = (btrfs_op(dio_bio) == BTRFS_MAP_WRITE);
 	const bool csum = !(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM);
 	size_t dip_size;
 	struct btrfs_dio_private *dip;
@@ -7777,7 +7777,7 @@ static struct btrfs_dio_private *btrfs_create_dio_private(struct bio *dio_bio,
 static blk_qc_t btrfs_submit_direct(struct inode *inode, struct iomap *iomap,
 		struct bio *dio_bio, loff_t file_offset)
 {
-	const bool write = (bio_op(dio_bio) == REQ_OP_WRITE);
+	const bool write = (btrfs_op(dio_bio) == BTRFS_MAP_WRITE);
 	const bool csum = !(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM);
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	const bool raid56 = (btrfs_data_alloc_profile(fs_info) &
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 9e69222086ae..a0056b205964 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -6446,7 +6446,7 @@ static void btrfs_end_bio(struct bio *bio)
 			struct btrfs_device *dev = btrfs_io_bio(bio)->device;
 
 			ASSERT(dev->bdev);
-			if (bio_op(bio) == REQ_OP_WRITE)
+			if (btrfs_op(bio) == BTRFS_MAP_WRITE)
 				btrfs_dev_stat_inc_and_print(dev,
 						BTRFS_DEV_STAT_WRITE_ERRS);
 			else if (!(bio->bi_opf & REQ_RAHEAD))
@@ -6559,10 +6559,10 @@ blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
 	atomic_set(&bbio->stripes_pending, bbio->num_stripes);
 
 	if ((bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) &&
-	    ((bio_op(bio) == REQ_OP_WRITE) || (mirror_num > 1))) {
+	    ((btrfs_op(bio) == BTRFS_MAP_WRITE) || (mirror_num > 1))) {
 		/* In this case, map_length has been set to the length of
 		   a single stripe; not the whole write */
-		if (bio_op(bio) == REQ_OP_WRITE) {
+		if (btrfs_op(bio) == BTRFS_MAP_WRITE) {
 			ret = raid56_parity_write(fs_info, bio, bbio,
 						  map_length);
 		} else {
@@ -6585,7 +6585,7 @@ blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
 		dev = bbio->stripes[dev_nr].dev;
 		if (!dev || !dev->bdev || test_bit(BTRFS_DEV_STATE_MISSING,
 						   &dev->dev_state) ||
-		    (bio_op(first_bio) == REQ_OP_WRITE &&
+		    (btrfs_op(first_bio) == BTRFS_MAP_WRITE &&
 		    !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))) {
 			bbio_error(bbio, first_bio, logical);
 			continue;
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 0249aca668fb..cff1f7689eac 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -410,6 +410,7 @@ static inline enum btrfs_map_op btrfs_op(struct bio *bio)
 	case REQ_OP_DISCARD:
 		return BTRFS_MAP_DISCARD;
 	case REQ_OP_WRITE:
+	case REQ_OP_ZONE_APPEND:
 		return BTRFS_MAP_WRITE;
 	default:
 		WARN_ON_ONCE(1);
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 23/41] btrfs: split ordered extent when bio is sent
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (20 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 22/41] btrfs: handle REQ_OP_ZONE_APPEND as writing Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 15:29     ` Josef Bacik
  2020-10-30 13:51   ` [PATCH v9 24/41] btrfs: extend btrfs_rmap_block for specifying a device Naohiro Aota
                     ` (18 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

For a zone append write, the device decides the location the data is
written to. Therefore we cannot ensure that two bios are written
consecutively on the device. In order to ensure that a ordered extent maps
to a contiguous region on disk, we need to maintain a "one bio == one
ordered extent" rule.

This commit implements the splitting of an ordered extent and extent map
on bio submission to adhere to the rule.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/inode.c        | 89 +++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/ordered-data.c | 76 +++++++++++++++++++++++++++++++++++
 fs/btrfs/ordered-data.h |  2 +
 3 files changed, 167 insertions(+)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 591ca539e444..6b2569dfc3bd 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2158,6 +2158,86 @@ static blk_status_t btrfs_submit_bio_start(void *private_data, struct bio *bio,
 	return btrfs_csum_one_bio(BTRFS_I(inode), bio, 0, 0);
 }
 
+int extract_ordered_extent(struct inode *inode, struct bio *bio,
+			   loff_t file_offset)
+{
+	struct btrfs_ordered_extent *ordered;
+	struct extent_map *em = NULL, *em_new = NULL;
+	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+	u64 start = (u64)bio->bi_iter.bi_sector << SECTOR_SHIFT;
+	u64 len = bio->bi_iter.bi_size;
+	u64 end = start + len;
+	u64 ordered_end;
+	u64 pre, post;
+	int ret = 0;
+
+	ordered = btrfs_lookup_ordered_extent(BTRFS_I(inode), file_offset);
+	if (WARN_ON_ONCE(!ordered))
+		return -EIO;
+
+	/* no need to split */
+	if (ordered->disk_num_bytes == len)
+		goto out;
+
+	/* cannot split once end_bio'd ordered extent */
+	if (WARN_ON_ONCE(ordered->bytes_left != ordered->disk_num_bytes)) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* we cannot split compressed ordered extent */
+	if (WARN_ON_ONCE(ordered->disk_num_bytes != ordered->num_bytes)) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* cannot split waietd ordered extent */
+	if (WARN_ON_ONCE(wq_has_sleeper(&ordered->wait))) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ordered_end = ordered->disk_bytenr + ordered->disk_num_bytes;
+	/* bio must be in one ordered extent */
+	if (WARN_ON_ONCE(start < ordered->disk_bytenr || end > ordered_end)) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* checksum list should be empty */
+	if (WARN_ON_ONCE(!list_empty(&ordered->list))) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	pre = start - ordered->disk_bytenr;
+	post = ordered_end - end;
+
+	btrfs_split_ordered_extent(ordered, pre, post);
+
+	read_lock(&em_tree->lock);
+	em = lookup_extent_mapping(em_tree, ordered->file_offset, len);
+	if (!em) {
+		read_unlock(&em_tree->lock);
+		ret = -EIO;
+		goto out;
+	}
+	read_unlock(&em_tree->lock);
+
+	ASSERT(!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags));
+	em_new = create_io_em(BTRFS_I(inode), em->start + pre, len,
+			      em->start + pre, em->block_start + pre, len,
+			      len, len, BTRFS_COMPRESS_NONE,
+			      BTRFS_ORDERED_REGULAR);
+	free_extent_map(em_new);
+
+out:
+	free_extent_map(em);
+	btrfs_put_ordered_extent(ordered);
+
+	return ret;
+}
+
 /*
  * extent_io.c submission hook. This does the right thing for csum calculation
  * on write, or reading the csums from the tree before a read.
@@ -2192,6 +2272,15 @@ blk_status_t btrfs_submit_data_bio(struct inode *inode, struct bio *bio,
 	if (btrfs_is_free_space_inode(BTRFS_I(inode)))
 		metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
 
+	if (bio_op(bio) == REQ_OP_ZONE_APPEND) {
+		struct page *page = bio_first_bvec_all(bio)->bv_page;
+		loff_t file_offset = page_offset(page);
+
+		ret = extract_ordered_extent(inode, bio, file_offset);
+		if (ret)
+			goto out;
+	}
+
 	if (btrfs_op(bio) != BTRFS_MAP_WRITE) {
 		ret = btrfs_bio_wq_end_io(fs_info, bio, metadata);
 		if (ret)
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index 87bac9ecdf4c..28fb9d5f48d3 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -943,6 +943,82 @@ void btrfs_lock_and_flush_ordered_range(struct btrfs_inode *inode, u64 start,
 	}
 }
 
+static void clone_ordered_extent(struct btrfs_ordered_extent *ordered, u64 pos,
+				 u64 len)
+{
+	struct inode *inode = ordered->inode;
+	u64 file_offset = ordered->file_offset + pos;
+	u64 disk_bytenr = ordered->disk_bytenr + pos;
+	u64 num_bytes = len;
+	u64 disk_num_bytes = len;
+	int type;
+	unsigned long flags_masked =
+		ordered->flags & ~(1 << BTRFS_ORDERED_DIRECT);
+	int compress_type = ordered->compress_type;
+	unsigned long weight;
+
+	weight = hweight_long(flags_masked);
+	WARN_ON_ONCE(weight > 1);
+	if (!weight)
+		type = 0;
+	else
+		type = __ffs(flags_masked);
+
+	if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered->flags)) {
+		WARN_ON_ONCE(1);
+		btrfs_add_ordered_extent_compress(BTRFS_I(inode), file_offset,
+						  disk_bytenr, num_bytes,
+						  disk_num_bytes, type,
+						  compress_type);
+	} else if (test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) {
+		btrfs_add_ordered_extent_dio(BTRFS_I(inode), file_offset,
+					     disk_bytenr, num_bytes,
+					     disk_num_bytes, type);
+	} else {
+		btrfs_add_ordered_extent(BTRFS_I(inode), file_offset,
+					 disk_bytenr, num_bytes, disk_num_bytes,
+					 type);
+	}
+}
+
+void btrfs_split_ordered_extent(struct btrfs_ordered_extent *ordered, u64 pre,
+				u64 post)
+{
+	struct inode *inode = ordered->inode;
+	struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
+	struct rb_node *node;
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+
+	spin_lock_irq(&tree->lock);
+	/* remove from tree once */
+	node = &ordered->rb_node;
+	rb_erase(node, &tree->tree);
+	RB_CLEAR_NODE(node);
+	if (tree->last == node)
+		tree->last = NULL;
+
+	ordered->file_offset += pre;
+	ordered->disk_bytenr += pre;
+	ordered->num_bytes -= (pre + post);
+	ordered->disk_num_bytes -= (pre + post);
+	ordered->bytes_left -= (pre + post);
+
+	/* re-insert the node */
+	node = tree_insert(&tree->tree, ordered->file_offset,
+			   &ordered->rb_node);
+	if (node)
+		btrfs_panic(fs_info, -EEXIST,
+				"inconsistency in ordered tree at offset %llu",
+				ordered->file_offset);
+
+	spin_unlock_irq(&tree->lock);
+
+	if (pre)
+		clone_ordered_extent(ordered, 0, pre);
+	if (post)
+		clone_ordered_extent(ordered, pre + ordered->disk_num_bytes, post);
+}
+
 int __init ordered_data_init(void)
 {
 	btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h
index c3a2325e64a4..e346b03bd66a 100644
--- a/fs/btrfs/ordered-data.h
+++ b/fs/btrfs/ordered-data.h
@@ -193,6 +193,8 @@ void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
 void btrfs_lock_and_flush_ordered_range(struct btrfs_inode *inode, u64 start,
 					u64 end,
 					struct extent_state **cached_state);
+void btrfs_split_ordered_extent(struct btrfs_ordered_extent *ordered, u64 pre,
+				u64 post);
 int __init ordered_data_init(void);
 void __cold ordered_data_exit(void);
 
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 24/41] btrfs: extend btrfs_rmap_block for specifying a device
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (21 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 23/41] btrfs: split ordered extent when bio is sent Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 15:32     ` Josef Bacik
  2020-10-30 13:51   ` [PATCH v9 25/41] btrfs: use ZONE_APPEND write for ZONED btrfs Naohiro Aota
                     ` (17 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

btrfs_rmap_block currently reverse-maps the physical addresses on all
devices to the corresponding logical addresses.

This commit extends the function to match to a specified device. The old
functionality of querying all devices is left intact by specifying NULL as
target device.

We pass block_device instead of btrfs_device to __btrfs_rmap_block. This
function is intended to reverse-map the result of bio, which only have
block_device.

This commit also exports the function for later use.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/block-group.c | 28 ++++++++++++++++++++++------
 fs/btrfs/block-group.h |  3 +++
 2 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index 82d556368c85..21e40046dce1 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -1644,8 +1644,11 @@ static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
 }
 
 /**
- * btrfs_rmap_block - Map a physical disk address to a list of logical addresses
+ * __btrfs_rmap_block - Map a physical disk address to a list of logical
+ *                      addresses
  * @chunk_start:   logical address of block group
+ * @bdev:	   physical device to resolve. Can be NULL to indicate any
+ *                 device.
  * @physical:	   physical address to map to logical addresses
  * @logical:	   return array of logical addresses which map to @physical
  * @naddrs:	   length of @logical
@@ -1655,9 +1658,9 @@ static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
  * Used primarily to exclude those portions of a block group that contain super
  * block copies.
  */
-EXPORT_FOR_TESTS
-int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
-		     u64 physical, u64 **logical, int *naddrs, int *stripe_len)
+int __btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
+		       struct block_device *bdev, u64 physical, u64 **logical,
+		       int *naddrs, int *stripe_len)
 {
 	struct extent_map *em;
 	struct map_lookup *map;
@@ -1675,6 +1678,7 @@ int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
 	map = em->map_lookup;
 	data_stripe_length = em->orig_block_len;
 	io_stripe_size = map->stripe_len;
+	chunk_start = em->start;
 
 	/* For RAID5/6 adjust to a full IO stripe length */
 	if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
@@ -1689,14 +1693,18 @@ int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
 	for (i = 0; i < map->num_stripes; i++) {
 		bool already_inserted = false;
 		u64 stripe_nr;
+		u64 offset;
 		int j;
 
 		if (!in_range(physical, map->stripes[i].physical,
 			      data_stripe_length))
 			continue;
 
+		if (bdev && map->stripes[i].dev->bdev != bdev)
+			continue;
+
 		stripe_nr = physical - map->stripes[i].physical;
-		stripe_nr = div64_u64(stripe_nr, map->stripe_len);
+		stripe_nr = div64_u64_rem(stripe_nr, map->stripe_len, &offset);
 
 		if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
 			stripe_nr = stripe_nr * map->num_stripes + i;
@@ -1710,7 +1718,7 @@ int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
 		 * instead of map->stripe_len
 		 */
 
-		bytenr = chunk_start + stripe_nr * io_stripe_size;
+		bytenr = chunk_start + stripe_nr * io_stripe_size + offset;
 
 		/* Ensure we don't add duplicate addresses */
 		for (j = 0; j < nr; j++) {
@@ -1732,6 +1740,14 @@ int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
 	return ret;
 }
 
+EXPORT_FOR_TESTS
+int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
+		     u64 physical, u64 **logical, int *naddrs, int *stripe_len)
+{
+	return __btrfs_rmap_block(fs_info, chunk_start, NULL, physical, logical,
+				  naddrs, stripe_len);
+}
+
 static int exclude_super_stripes(struct btrfs_block_group *cache)
 {
 	struct btrfs_fs_info *fs_info = cache->fs_info;
diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index 5be47f4bfea7..401e9bcefaec 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -275,6 +275,9 @@ void check_system_chunk(struct btrfs_trans_handle *trans, const u64 type);
 u64 btrfs_get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags);
 void btrfs_put_block_group_cache(struct btrfs_fs_info *info);
 int btrfs_free_block_groups(struct btrfs_fs_info *info);
+int __btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
+		       struct block_device *bdev, u64 physical, u64 **logical,
+		       int *naddrs, int *stripe_len);
 
 static inline u64 btrfs_data_alloc_profile(struct btrfs_fs_info *fs_info)
 {
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 25/41] btrfs: use ZONE_APPEND write for ZONED btrfs
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (22 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 24/41] btrfs: extend btrfs_rmap_block for specifying a device Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 15:55     ` Josef Bacik
  2020-10-30 13:51   ` [PATCH v9 26/41] btrfs: enable zone append writing for direct IO Naohiro Aota
                     ` (16 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba
  Cc: hare, linux-fsdevel, Naohiro Aota, Johannes Thumshirn

This commit enables zone append writing for zoned btrfs. When using zone
append, a bio is issued to the start of a target zone and the device
decides to place it inside the zone. Upon completion the device reports
the actual written position back to the host.

Three parts are necessary to enable zone append in btrfs. First, modify
the bio to use REQ_OP_ZONE_APPEND in btrfs_submit_bio_hook() and adjust
the bi_sector to point the beginning of the zone.

Secondly, records the returned physical address (and disk/partno) to the
ordered extent in end_bio_extent_writepage() after the bio has been
completed. We cannot resolve the physical address to the logical address
because we can neither take locks nor allocate a buffer in this end_bio
context. So, we need to record the physical address to resolve it later in
btrfs_finish_ordered_io().

And finally, rewrites the logical addresses of the extent mapping and
checksum data according to the physical address (using __btrfs_rmap_block).
If the returned address matches the originally allocated address, we can
skip this rewriting process.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/extent_io.c    | 12 +++++++-
 fs/btrfs/file.c         |  2 +-
 fs/btrfs/inode.c        |  4 +++
 fs/btrfs/ordered-data.c |  3 ++
 fs/btrfs/ordered-data.h |  8 +++++
 fs/btrfs/volumes.c      |  9 ++++++
 fs/btrfs/zoned.c        | 68 +++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/zoned.h        |  9 ++++++
 8 files changed, 113 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 764257eb658f..3f49febafc69 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2743,6 +2743,7 @@ static void end_bio_extent_writepage(struct bio *bio)
 	u64 start;
 	u64 end;
 	struct bvec_iter_all iter_all;
+	bool first_bvec = true;
 
 	ASSERT(!bio_flagged(bio, BIO_CLONED));
 	bio_for_each_segment_all(bvec, bio, iter_all) {
@@ -2769,6 +2770,11 @@ static void end_bio_extent_writepage(struct bio *bio)
 		start = page_offset(page);
 		end = start + bvec->bv_offset + bvec->bv_len - 1;
 
+		if (first_bvec) {
+			btrfs_record_physical_zoned(inode, start, bio);
+			first_bvec = false;
+		}
+
 		end_extent_writepage(page, error, start, end);
 		end_page_writeback(page);
 	}
@@ -3531,6 +3537,7 @@ static noinline_for_stack int __extent_writepage_io(struct btrfs_inode *inode,
 	size_t blocksize;
 	int ret = 0;
 	int nr = 0;
+	int opf = REQ_OP_WRITE;
 	const unsigned int write_flags = wbc_to_write_flags(wbc);
 	bool compressed;
 
@@ -3543,6 +3550,9 @@ static noinline_for_stack int __extent_writepage_io(struct btrfs_inode *inode,
 		return 1;
 	}
 
+	if (btrfs_is_zoned(inode->root->fs_info))
+		opf = REQ_OP_ZONE_APPEND;
+
 	/*
 	 * we don't want to touch the inode after unlocking the page,
 	 * so we update the mapping writeback index now
@@ -3603,7 +3613,7 @@ static noinline_for_stack int __extent_writepage_io(struct btrfs_inode *inode,
 			       page->index, cur, end);
 		}
 
-		ret = submit_extent_page(REQ_OP_WRITE | write_flags, wbc,
+		ret = submit_extent_page(opf | write_flags, wbc,
 					 page, offset, iosize, pg_offset,
 					 &epd->bio,
 					 end_bio_extent_writepage,
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 68938a43081e..f41cdcbf44f5 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -2226,7 +2226,7 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
 	 * the current transaction commits before the ordered extents complete
 	 * and a power failure happens right after that.
 	 */
-	if (full_sync) {
+	if (full_sync || fs_info->zoned) {
 		ret = btrfs_wait_ordered_range(inode, start, len);
 	} else {
 		/*
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 6b2569dfc3bd..6d40affa833f 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -51,6 +51,7 @@
 #include "delalloc-space.h"
 #include "block-group.h"
 #include "space-info.h"
+#include "zoned.h"
 
 struct btrfs_iget_args {
 	u64 ino;
@@ -2676,6 +2677,9 @@ static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
 	bool clear_reserved_extent = true;
 	unsigned int clear_bits;
 
+	if (ordered_extent->disk)
+		btrfs_rewrite_logical_zoned(ordered_extent);
+
 	start = ordered_extent->file_offset;
 	end = start + ordered_extent->num_bytes - 1;
 
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index 28fb9d5f48d3..b2d185d4479e 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -199,6 +199,9 @@ static int __btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset
 	entry->compress_type = compress_type;
 	entry->truncated_len = (u64)-1;
 	entry->qgroup_rsv = ret;
+	entry->physical = (u64)-1;
+	entry->disk = NULL;
+	entry->partno = (u8)-1;
 	if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)
 		set_bit(type, &entry->flags);
 
diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h
index e346b03bd66a..084c609afd83 100644
--- a/fs/btrfs/ordered-data.h
+++ b/fs/btrfs/ordered-data.h
@@ -127,6 +127,14 @@ struct btrfs_ordered_extent {
 	struct completion completion;
 	struct btrfs_work flush_work;
 	struct list_head work_list;
+
+	/*
+	 * used to reverse-map physical address returned from ZONE_APPEND
+	 * write command in a workqueue context.
+	 */
+	u64 physical;
+	struct gendisk *disk;
+	u8 partno;
 };
 
 /*
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index a0056b205964..26669007d367 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -6498,6 +6498,15 @@ static void submit_stripe_bio(struct btrfs_bio *bbio, struct bio *bio,
 	btrfs_io_bio(bio)->device = dev;
 	bio->bi_end_io = btrfs_end_bio;
 	bio->bi_iter.bi_sector = physical >> 9;
+	/*
+	 * For zone append writing, bi_sector must point the beginning of the
+	 * zone
+	 */
+	if (bio_op(bio) == REQ_OP_ZONE_APPEND) {
+		u64 zone_start = round_down(physical, fs_info->zone_size);
+
+		bio->bi_iter.bi_sector = zone_start >> SECTOR_SHIFT;
+	}
 	btrfs_debug_in_rcu(fs_info,
 	"btrfs_map_bio: rw %d 0x%x, sector=%llu, dev=%lu (%s id %llu), size=%u",
 		bio_op(bio), bio->bi_opf, (u64)bio->bi_iter.bi_sector,
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index b45ca33282d9..50393d560c9a 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -1052,3 +1052,71 @@ void btrfs_free_redirty_list(struct btrfs_transaction *trans)
 	}
 	spin_unlock(&trans->releasing_ebs_lock);
 }
+
+void btrfs_record_physical_zoned(struct inode *inode, u64 file_offset,
+				 struct bio *bio)
+{
+	struct btrfs_ordered_extent *ordered;
+	u64 physical = (u64)bio->bi_iter.bi_sector << SECTOR_SHIFT;
+
+	if (bio_op(bio) != REQ_OP_ZONE_APPEND)
+		return;
+
+	ordered = btrfs_lookup_ordered_extent(BTRFS_I(inode), file_offset);
+	if (WARN_ON(!ordered))
+		return;
+
+	ordered->physical = physical;
+	ordered->disk = bio->bi_disk;
+	ordered->partno = bio->bi_partno;
+
+	btrfs_put_ordered_extent(ordered);
+}
+
+void btrfs_rewrite_logical_zoned(struct btrfs_ordered_extent *ordered)
+{
+	struct extent_map_tree *em_tree;
+	struct extent_map *em;
+	struct inode *inode = ordered->inode;
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	struct btrfs_ordered_sum *sum;
+	struct block_device *bdev;
+	u64 orig_logical = ordered->disk_bytenr;
+	u64 *logical = NULL;
+	int nr, stripe_len;
+
+	bdev = bdget_disk(ordered->disk, ordered->partno);
+	if (WARN_ON(!bdev))
+		return;
+
+	if (WARN_ON(__btrfs_rmap_block(fs_info, orig_logical, bdev,
+				       ordered->physical, &logical, &nr,
+				       &stripe_len)))
+		goto out;
+
+	WARN_ON(nr != 1);
+
+	if (orig_logical == *logical)
+		goto out;
+
+	ordered->disk_bytenr = *logical;
+
+	em_tree = &BTRFS_I(inode)->extent_tree;
+	write_lock(&em_tree->lock);
+	em = search_extent_mapping(em_tree, ordered->file_offset,
+				   ordered->num_bytes);
+	em->block_start = *logical;
+	free_extent_map(em);
+	write_unlock(&em_tree->lock);
+
+	list_for_each_entry(sum, &ordered->list, list) {
+		if (*logical < orig_logical)
+			sum->bytenr -= orig_logical - *logical;
+		else
+			sum->bytenr += *logical - orig_logical;
+	}
+
+out:
+	kfree(logical);
+	bdput(bdev);
+}
diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h
index 845623932fa5..d3ed4d7dae2b 100644
--- a/fs/btrfs/zoned.h
+++ b/fs/btrfs/zoned.h
@@ -44,6 +44,9 @@ void btrfs_calc_zone_unusable(struct btrfs_block_group *cache);
 void btrfs_redirty_list_add(struct btrfs_transaction *trans,
 			    struct extent_buffer *eb);
 void btrfs_free_redirty_list(struct btrfs_transaction *trans);
+void btrfs_record_physical_zoned(struct inode *inode, u64 file_offset,
+				 struct bio *bio);
+void btrfs_rewrite_logical_zoned(struct btrfs_ordered_extent *ordered);
 #else /* CONFIG_BLK_DEV_ZONED */
 static inline int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
 				     struct blk_zone *zone)
@@ -113,6 +116,12 @@ static inline void btrfs_calc_zone_unusable(struct btrfs_block_group *cache) { }
 static inline void btrfs_redirty_list_add(struct btrfs_transaction *trans,
 					  struct extent_buffer *eb) { }
 static inline void btrfs_free_redirty_list(struct btrfs_transaction *trans) { }
+static inline void btrfs_record_physical_zoned(struct inode *inode,
+					       u64 file_offset, struct bio *bio)
+{
+}
+static inline void
+btrfs_rewrite_logical_zoned(struct btrfs_ordered_extent *ordered) { }
 #endif
 
 static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos)
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 26/41] btrfs: enable zone append writing for direct IO
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (23 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 25/41] btrfs: use ZONE_APPEND write for ZONED btrfs Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 15:56     ` Josef Bacik
  2020-10-30 13:51   ` [PATCH v9 27/41] btrfs: introduce dedicated data write path for ZONED mode Naohiro Aota
                     ` (15 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

Likewise to buffered IO, enable zone append writing for direct IO when its
used on a zoned block device.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/inode.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 6d40affa833f..bc853a4f22cc 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7542,6 +7542,9 @@ static int btrfs_dio_iomap_begin(struct inode *inode, loff_t start,
 	iomap->bdev = fs_info->fs_devices->latest_bdev;
 	iomap->length = len;
 
+	if (write && btrfs_is_zoned(fs_info) && fs_info->max_zone_append_size)
+		iomap->flags |= IOMAP_F_ZONE_APPEND;
+
 	free_extent_map(em);
 
 	return 0;
@@ -7779,6 +7782,8 @@ static void btrfs_end_dio_bio(struct bio *bio)
 	if (err)
 		dip->dio_bio->bi_status = err;
 
+	btrfs_record_physical_zoned(dip->inode, dip->logical_offset, bio);
+
 	bio_put(bio);
 	btrfs_dio_private_put(dip);
 }
@@ -7933,6 +7938,18 @@ static blk_qc_t btrfs_submit_direct(struct inode *inode, struct iomap *iomap,
 		bio->bi_end_io = btrfs_end_dio_bio;
 		btrfs_io_bio(bio)->logical = file_offset;
 
+		WARN_ON_ONCE(write && btrfs_is_zoned(fs_info) &&
+			     fs_info->max_zone_append_size &&
+			     bio_op(bio) != REQ_OP_ZONE_APPEND);
+
+		if (bio_op(bio) == REQ_OP_ZONE_APPEND) {
+			ret = extract_ordered_extent(inode, bio, file_offset);
+			if (ret) {
+				bio_put(bio);
+				goto out_err;
+			}
+		}
+
 		ASSERT(submit_len >= clone_len);
 		submit_len -= clone_len;
 
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 27/41] btrfs: introduce dedicated data write path for ZONED mode
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (24 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 26/41] btrfs: enable zone append writing for direct IO Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 15:57     ` Josef Bacik
  2020-10-30 13:51   ` [PATCH v9 28/41] btrfs: serialize meta IOs on " Naohiro Aota
                     ` (14 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

If more than one IO is issued for one file extent, these IO can be written
to separate regions on a device. Since we cannot map one file extent to
such a separate area, we need to follow the "one IO == one ordered extent"
rule.

The Normal buffered, uncompressed, not pre-allocated write path (used by
cow_file_range()) sometimes does not follow this rule. It can write a part
of an ordered extent when specified a region to write e.g., when its
called from fdatasync().

Introduces a dedicated (uncompressed buffered) data write path for ZONED
mode. This write path will CoW the region and write it at once.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/inode.c | 34 ++++++++++++++++++++++++++++++++--
 1 file changed, 32 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index bc853a4f22cc..fdc367a39194 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1350,6 +1350,29 @@ static int cow_file_range_async(struct btrfs_inode *inode,
 	return 0;
 }
 
+static noinline int run_delalloc_zoned(struct btrfs_inode *inode,
+				       struct page *locked_page, u64 start,
+				       u64 end, int *page_started,
+				       unsigned long *nr_written)
+{
+	int ret;
+
+	ret = cow_file_range(inode, locked_page, start, end,
+			     page_started, nr_written, 0);
+	if (ret)
+		return ret;
+
+	if (*page_started)
+		return 0;
+
+	__set_page_dirty_nobuffers(locked_page);
+	account_page_redirty(locked_page);
+	extent_write_locked_range(&inode->vfs_inode, start, end, WB_SYNC_ALL);
+	*page_started = 1;
+
+	return 0;
+}
+
 static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info,
 					u64 bytenr, u64 num_bytes)
 {
@@ -1820,17 +1843,24 @@ int btrfs_run_delalloc_range(struct btrfs_inode *inode, struct page *locked_page
 {
 	int ret;
 	int force_cow = need_force_cow(inode, start, end);
+	int do_compress = inode_can_compress(inode) &&
+		inode_need_compress(inode, start, end);
+	bool zoned = btrfs_is_zoned(inode->root->fs_info);
 
 	if (inode->flags & BTRFS_INODE_NODATACOW && !force_cow) {
+		ASSERT(!zoned);
 		ret = run_delalloc_nocow(inode, locked_page, start, end,
 					 page_started, 1, nr_written);
 	} else if (inode->flags & BTRFS_INODE_PREALLOC && !force_cow) {
+		ASSERT(!zoned);
 		ret = run_delalloc_nocow(inode, locked_page, start, end,
 					 page_started, 0, nr_written);
-	} else if (!inode_can_compress(inode) ||
-		   !inode_need_compress(inode, start, end)) {
+	} else if (!do_compress && !zoned) {
 		ret = cow_file_range(inode, locked_page, start, end,
 				     page_started, nr_written, 1);
+	} else if (!do_compress && zoned) {
+		ret = run_delalloc_zoned(inode, locked_page, start, end,
+					 page_started, nr_written);
 	} else {
 		set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, &inode->runtime_flags);
 		ret = cow_file_range_async(inode, wbc, locked_page, start, end,
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 28/41] btrfs: serialize meta IOs on ZONED mode
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (25 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 27/41] btrfs: introduce dedicated data write path for ZONED mode Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 16:04     ` Josef Bacik
  2020-10-30 13:51   ` [PATCH v9 29/41] btrfs: wait existing extents before truncating Naohiro Aota
                     ` (13 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

We cannot use zone append for writing metadata, because the B-tree nodes
have references to each other using the logical address. Without knowing
the address in advance, we cannot construct the tree in the first place.
So we need to serialize write IOs for metadata.

We cannot add a mutex around allocation and submission because metadata
blocks are allocated in an earlier stage to build up B-trees.

Add a zoned_meta_io_lock and hold it during metadata IO submission in
btree_write_cache_pages() to serialize IOs. Furthermore, this add a
per-block group metadata IO submission pointer "meta_write_pointer" to
ensure sequential writing, which can be caused when writing back blocks in
an unfinished transaction.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/block-group.h |  1 +
 fs/btrfs/ctree.h       |  1 +
 fs/btrfs/disk-io.c     |  1 +
 fs/btrfs/extent_io.c   | 27 ++++++++++++++++++++++-
 fs/btrfs/zoned.c       | 50 ++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/zoned.h       | 31 ++++++++++++++++++++++++++
 6 files changed, 110 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index 401e9bcefaec..b2a8a3beceac 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -190,6 +190,7 @@ struct btrfs_block_group {
 	 */
 	u64 alloc_offset;
 	u64 zone_unusable;
+	u64 meta_write_pointer;
 };
 
 static inline u64 btrfs_block_group_end(struct btrfs_block_group *block_group)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 383c83a1f5b5..736f679f1310 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -955,6 +955,7 @@ struct btrfs_fs_info {
 	};
 	/* max size to emit ZONE_APPEND write command */
 	u64 max_zone_append_size;
+	struct mutex zoned_meta_io_lock;
 
 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
 	spinlock_t ref_verify_lock;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 778716e223ff..f02b121d8213 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2652,6 +2652,7 @@ void btrfs_init_fs_info(struct btrfs_fs_info *fs_info)
 	mutex_init(&fs_info->delete_unused_bgs_mutex);
 	mutex_init(&fs_info->reloc_mutex);
 	mutex_init(&fs_info->delalloc_root_mutex);
+	mutex_init(&fs_info->zoned_meta_io_lock);
 	seqlock_init(&fs_info->profiles_lock);
 
 	INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 3f49febafc69..3cce444d5dbb 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -25,6 +25,7 @@
 #include "backref.h"
 #include "disk-io.h"
 #include "zoned.h"
+#include "block-group.h"
 
 static struct kmem_cache *extent_state_cache;
 static struct kmem_cache *extent_buffer_cache;
@@ -4001,6 +4002,7 @@ int btree_write_cache_pages(struct address_space *mapping,
 				   struct writeback_control *wbc)
 {
 	struct extent_buffer *eb, *prev_eb = NULL;
+	struct btrfs_block_group *cache = NULL;
 	struct extent_page_data epd = {
 		.bio = NULL,
 		.extent_locked = 0,
@@ -4035,6 +4037,7 @@ int btree_write_cache_pages(struct address_space *mapping,
 		tag = PAGECACHE_TAG_TOWRITE;
 	else
 		tag = PAGECACHE_TAG_DIRTY;
+	btrfs_zoned_meta_io_lock(fs_info);
 retry:
 	if (wbc->sync_mode == WB_SYNC_ALL)
 		tag_pages_for_writeback(mapping, index, end);
@@ -4077,12 +4080,30 @@ int btree_write_cache_pages(struct address_space *mapping,
 			if (!ret)
 				continue;
 
+			if (!btrfs_check_meta_write_pointer(fs_info, eb,
+							    &cache)) {
+				/*
+				 * If for_sync, this hole will be filled with
+				 * trasnsaction commit.
+				 */
+				if (wbc->sync_mode == WB_SYNC_ALL &&
+				    !wbc->for_sync)
+					ret = -EAGAIN;
+				else
+					ret = 0;
+				done = 1;
+				free_extent_buffer(eb);
+				break;
+			}
+
 			prev_eb = eb;
 			ret = lock_extent_buffer_for_io(eb, &epd);
 			if (!ret) {
+				btrfs_revert_meta_write_pointer(cache, eb);
 				free_extent_buffer(eb);
 				continue;
 			} else if (ret < 0) {
+				btrfs_revert_meta_write_pointer(cache, eb);
 				done = 1;
 				free_extent_buffer(eb);
 				break;
@@ -4115,10 +4136,12 @@ int btree_write_cache_pages(struct address_space *mapping,
 		index = 0;
 		goto retry;
 	}
+	if (cache)
+		btrfs_put_block_group(cache);
 	ASSERT(ret <= 0);
 	if (ret < 0) {
 		end_write_bio(&epd, ret);
-		return ret;
+		goto out;
 	}
 	/*
 	 * If something went wrong, don't allow any metadata write bio to be
@@ -4153,6 +4176,8 @@ int btree_write_cache_pages(struct address_space *mapping,
 		ret = -EROFS;
 		end_write_bio(&epd, ret);
 	}
+out:
+	btrfs_zoned_meta_io_unlock(fs_info);
 	return ret;
 }
 
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index 50393d560c9a..15bc7d451348 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -989,6 +989,9 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache)
 		ret = -EIO;
 	}
 
+	if (!ret)
+		cache->meta_write_pointer = cache->alloc_offset + cache->start;
+
 	kfree(alloc_offsets);
 	free_extent_map(em);
 
@@ -1120,3 +1123,50 @@ void btrfs_rewrite_logical_zoned(struct btrfs_ordered_extent *ordered)
 	kfree(logical);
 	bdput(bdev);
 }
+
+bool btrfs_check_meta_write_pointer(struct btrfs_fs_info *fs_info,
+				    struct extent_buffer *eb,
+				    struct btrfs_block_group **cache_ret)
+{
+	struct btrfs_block_group *cache;
+
+	if (!btrfs_is_zoned(fs_info))
+		return true;
+
+	cache = *cache_ret;
+
+	if (cache && (eb->start < cache->start ||
+		      cache->start + cache->length <= eb->start)) {
+		btrfs_put_block_group(cache);
+		cache = NULL;
+		*cache_ret = NULL;
+	}
+
+	if (!cache)
+		cache = btrfs_lookup_block_group(fs_info, eb->start);
+
+	if (cache) {
+		*cache_ret = cache;
+
+		if (cache->meta_write_pointer != eb->start) {
+			btrfs_put_block_group(cache);
+			cache = NULL;
+			*cache_ret = NULL;
+			return false;
+		}
+
+		cache->meta_write_pointer = eb->start + eb->len;
+	}
+
+	return true;
+}
+
+void btrfs_revert_meta_write_pointer(struct btrfs_block_group *cache,
+				     struct extent_buffer *eb)
+{
+	if (!btrfs_is_zoned(eb->fs_info) || !cache)
+		return;
+
+	ASSERT(cache->meta_write_pointer == eb->start + eb->len);
+	cache->meta_write_pointer = eb->start;
+}
diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h
index d3ed4d7dae2b..262b248a9085 100644
--- a/fs/btrfs/zoned.h
+++ b/fs/btrfs/zoned.h
@@ -47,6 +47,11 @@ void btrfs_free_redirty_list(struct btrfs_transaction *trans);
 void btrfs_record_physical_zoned(struct inode *inode, u64 file_offset,
 				 struct bio *bio);
 void btrfs_rewrite_logical_zoned(struct btrfs_ordered_extent *ordered);
+bool btrfs_check_meta_write_pointer(struct btrfs_fs_info *fs_info,
+				    struct extent_buffer *eb,
+				    struct btrfs_block_group **cache_ret);
+void btrfs_revert_meta_write_pointer(struct btrfs_block_group *cache,
+				     struct extent_buffer *eb);
 #else /* CONFIG_BLK_DEV_ZONED */
 static inline int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
 				     struct blk_zone *zone)
@@ -122,6 +127,18 @@ static inline void btrfs_record_physical_zoned(struct inode *inode,
 }
 static inline void
 btrfs_rewrite_logical_zoned(struct btrfs_ordered_extent *ordered) { }
+static inline bool
+btrfs_check_meta_write_pointer(struct btrfs_fs_info *fs_info,
+			       struct extent_buffer *eb,
+			       struct btrfs_block_group **cache_ret)
+{
+	return true;
+}
+static inline void
+btrfs_revert_meta_write_pointer(struct btrfs_block_group *cache,
+				struct extent_buffer *eb)
+{
+}
 #endif
 
 static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos)
@@ -224,4 +241,18 @@ static inline bool btrfs_can_zone_reset(struct btrfs_device *device,
 	return true;
 }
 
+static inline void btrfs_zoned_meta_io_lock(struct btrfs_fs_info *fs_info)
+{
+	if (!btrfs_is_zoned(fs_info))
+		return;
+	mutex_lock(&fs_info->zoned_meta_io_lock);
+}
+
+static inline void btrfs_zoned_meta_io_unlock(struct btrfs_fs_info *fs_info)
+{
+	if (!btrfs_is_zoned(fs_info))
+		return;
+	mutex_unlock(&fs_info->zoned_meta_io_lock);
+}
+
 #endif
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 29/41] btrfs: wait existing extents before truncating
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (26 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 28/41] btrfs: serialize meta IOs on " Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-10-30 13:51   ` [PATCH v9 30/41] btrfs: avoid async metadata checksum on ZONED mode Naohiro Aota
                     ` (12 subsequent siblings)
  40 siblings, 0 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota, Josef Bacik

When truncating a file, file buffers which have already been allocated but
not yet written may be truncated.  Truncating these buffers could cause
breakage of a sequential write pattern in a block group if the truncated
blocks are for example followed by blocks allocated to another file. To
avoid this problem, always wait for write out of all unwritten buffers
before proceeding with the truncate execution.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/inode.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index fdc367a39194..de8b58abed1d 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4955,6 +4955,16 @@ static int btrfs_setsize(struct inode *inode, struct iattr *attr)
 		btrfs_drew_write_unlock(&root->snapshot_lock);
 		btrfs_end_transaction(trans);
 	} else {
+		struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+
+		if (btrfs_is_zoned(fs_info)) {
+			ret = btrfs_wait_ordered_range(
+				inode,
+				ALIGN(newsize, fs_info->sectorsize),
+				(u64)-1);
+			if (ret)
+				return ret;
+		}
 
 		/*
 		 * We're truncating a file that used to have good data down to
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 30/41] btrfs: avoid async metadata checksum on ZONED mode
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (27 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 29/41] btrfs: wait existing extents before truncating Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 16:05     ` Josef Bacik
  2020-10-30 13:51   ` [PATCH v9 31/41] btrfs: mark block groups to copy for device-replace Naohiro Aota
                     ` (11 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

In ZONED, btrfs uses per-FS zoned_meta_io_lock to serialize the metadata
write IOs.

Even with these serialization, write bios sent from btree_write_cache_pages
can be reordered by async checksum workers as these workers are per CPU and
not per zone.

To preserve write BIO ordering, we can disable async metadata checksum on
ZONED.  This does not result in lower performance with HDDs as a single CPU
core is fast enough to do checksum for a single zone write stream with the
maximum possible bandwidth of the device. If multiple zones are being
written simultaneously, HDD seek overhead lowers the achievable maximum
bandwidth, resulting again in a per zone checksum serialization not
affecting performance.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/disk-io.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index f02b121d8213..2b30ef8a7034 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -813,6 +813,8 @@ static blk_status_t btree_submit_bio_start(void *private_data, struct bio *bio,
 static int check_async_write(struct btrfs_fs_info *fs_info,
 			     struct btrfs_inode *bi)
 {
+	if (btrfs_is_zoned(fs_info))
+		return 0;
 	if (atomic_read(&bi->sync_writers))
 		return 0;
 	if (test_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags))
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 31/41] btrfs: mark block groups to copy for device-replace
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (28 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 30/41] btrfs: avoid async metadata checksum on ZONED mode Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 17:09     ` Josef Bacik
  2020-10-30 13:51   ` [PATCH v9 32/41] btrfs: implement cloning for ZONED device-replace Naohiro Aota
                     ` (10 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

This is the 1/4 patch to support device-replace in ZONED mode.

We have two types of I/Os during the device-replace process. One is an I/O
to "copy" (by the scrub functions) all the device extents on the source
device to the destination device.  The other one is an I/O to "clone" (by
handle_ops_on_dev_replace()) new incoming write I/Os from users to the
source device into the target device.

Cloning incoming I/Os can break the sequential write rule in the target
device. When writing is mapped in the middle of a block group, the I/O is
directed in the middle of a target device zone, which breaks the sequential
write rule.

However, the cloning function cannot be merely disabled since incoming I/Os
targeting already copied device extents must be cloned so that the I/O is
executed on the target device.

We cannot use dev_replace->cursor_{left,right} to determine whether bio is
going to not yet copied region.  Since we have a time gap between finishing
btrfs_scrub_dev() and rewriting the mapping tree in
btrfs_dev_replace_finishing(), we can have a newly allocated device extent
which is never cloned nor copied.

So the point is to copy only already existing device extents. This patch
introduces mark_block_group_to_copy() to mark existing block groups as a
target of copying. Then, handle_ops_on_dev_replace() and dev-replace can
check the flag to do their job.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/block-group.h |   1 +
 fs/btrfs/dev-replace.c | 175 +++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/dev-replace.h |   3 +
 fs/btrfs/scrub.c       |  17 ++++
 4 files changed, 196 insertions(+)

diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index b2a8a3beceac..e91123495d68 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -95,6 +95,7 @@ struct btrfs_block_group {
 	unsigned int iref:1;
 	unsigned int has_caching_ctl:1;
 	unsigned int removed:1;
+	unsigned int to_copy:1;
 
 	int disk_cache_state;
 
diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index 5e3554482af1..e86aff38aea4 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -22,6 +22,7 @@
 #include "dev-replace.h"
 #include "sysfs.h"
 #include "zoned.h"
+#include "block-group.h"
 
 /*
  * Device replace overview
@@ -437,6 +438,176 @@ static char* btrfs_dev_name(struct btrfs_device *device)
 		return rcu_str_deref(device->name);
 }
 
+static int mark_block_group_to_copy(struct btrfs_fs_info *fs_info,
+				    struct btrfs_device *src_dev)
+{
+	struct btrfs_path *path;
+	struct btrfs_key key;
+	struct btrfs_key found_key;
+	struct btrfs_root *root = fs_info->dev_root;
+	struct btrfs_dev_extent *dev_extent = NULL;
+	struct btrfs_block_group *cache;
+	struct extent_buffer *l;
+	struct btrfs_trans_handle *trans;
+	int slot;
+	int ret = 0;
+	u64 chunk_offset, length;
+
+	/* Do not use "to_copy" on non-ZONED for now */
+	if (!btrfs_fs_incompat(fs_info, ZONED))
+		return 0;
+
+	mutex_lock(&fs_info->chunk_mutex);
+
+	/* ensulre we don't have pending new block group */
+	while (fs_info->running_transaction &&
+	       !list_empty(&fs_info->running_transaction->dev_update_list)) {
+		mutex_unlock(&fs_info->chunk_mutex);
+		trans = btrfs_attach_transaction(root);
+		if (IS_ERR(trans)) {
+			ret = PTR_ERR(trans);
+			mutex_lock(&fs_info->chunk_mutex);
+			if (ret == -ENOENT)
+				continue;
+			else
+				goto out;
+		}
+
+		ret = btrfs_commit_transaction(trans);
+		mutex_lock(&fs_info->chunk_mutex);
+		if (ret)
+			goto out;
+	}
+
+	path = btrfs_alloc_path();
+	if (!path) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	path->reada = READA_FORWARD;
+	path->search_commit_root = 1;
+	path->skip_locking = 1;
+
+	key.objectid = src_dev->devid;
+	key.offset = 0ull;
+	key.type = BTRFS_DEV_EXTENT_KEY;
+
+	while (1) {
+		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+		if (ret < 0)
+			break;
+		if (ret > 0) {
+			if (path->slots[0] >=
+			    btrfs_header_nritems(path->nodes[0])) {
+				ret = btrfs_next_leaf(root, path);
+				if (ret < 0)
+					break;
+				if (ret > 0) {
+					ret = 0;
+					break;
+				}
+			} else {
+				ret = 0;
+			}
+		}
+
+		l = path->nodes[0];
+		slot = path->slots[0];
+
+		btrfs_item_key_to_cpu(l, &found_key, slot);
+
+		if (found_key.objectid != src_dev->devid)
+			break;
+
+		if (found_key.type != BTRFS_DEV_EXTENT_KEY)
+			break;
+
+		if (found_key.offset < key.offset)
+			break;
+
+		dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
+		length = btrfs_dev_extent_length(l, dev_extent);
+
+		chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
+
+		cache = btrfs_lookup_block_group(fs_info, chunk_offset);
+		if (!cache)
+			goto skip;
+
+		spin_lock(&cache->lock);
+		cache->to_copy = 1;
+		spin_unlock(&cache->lock);
+
+		btrfs_put_block_group(cache);
+
+skip:
+		key.offset = found_key.offset + length;
+		btrfs_release_path(path);
+	}
+
+	btrfs_free_path(path);
+out:
+	mutex_unlock(&fs_info->chunk_mutex);
+
+	return ret;
+}
+
+bool btrfs_finish_block_group_to_copy(struct btrfs_device *srcdev,
+				      struct btrfs_block_group *cache,
+				      u64 physical)
+{
+	struct btrfs_fs_info *fs_info = cache->fs_info;
+	struct extent_map *em;
+	struct map_lookup *map;
+	u64 chunk_offset = cache->start;
+	int num_extents, cur_extent;
+	int i;
+
+	/* Do not use "to_copy" on non-ZONED for now */
+	if (!btrfs_fs_incompat(fs_info, ZONED))
+		return true;
+
+	spin_lock(&cache->lock);
+	if (cache->removed) {
+		spin_unlock(&cache->lock);
+		return true;
+	}
+	spin_unlock(&cache->lock);
+
+	em = btrfs_get_chunk_map(fs_info, chunk_offset, 1);
+	BUG_ON(IS_ERR(em));
+	map = em->map_lookup;
+
+	num_extents = cur_extent = 0;
+	for (i = 0; i < map->num_stripes; i++) {
+		/* we have more device extent to copy */
+		if (srcdev != map->stripes[i].dev)
+			continue;
+
+		num_extents++;
+		if (physical == map->stripes[i].physical)
+			cur_extent = i;
+	}
+
+	free_extent_map(em);
+
+	if (num_extents > 1 && cur_extent < num_extents - 1) {
+		/*
+		 * Has more stripes on this device. Keep this BG
+		 * readonly until we finish all the stripes.
+		 */
+		return false;
+	}
+
+	/* last stripe on this device */
+	spin_lock(&cache->lock);
+	cache->to_copy = 0;
+	spin_unlock(&cache->lock);
+
+	return true;
+}
+
 static int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info,
 		const char *tgtdev_name, u64 srcdevid, const char *srcdev_name,
 		int read_src)
@@ -478,6 +649,10 @@ static int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info,
 	if (ret)
 		return ret;
 
+	ret = mark_block_group_to_copy(fs_info, src_device);
+	if (ret)
+		return ret;
+
 	down_write(&dev_replace->rwsem);
 	switch (dev_replace->replace_state) {
 	case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
diff --git a/fs/btrfs/dev-replace.h b/fs/btrfs/dev-replace.h
index 60b70dacc299..3911049a5f23 100644
--- a/fs/btrfs/dev-replace.h
+++ b/fs/btrfs/dev-replace.h
@@ -18,5 +18,8 @@ int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info);
 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info);
 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info);
 int __pure btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace);
+bool btrfs_finish_block_group_to_copy(struct btrfs_device *srcdev,
+				      struct btrfs_block_group *cache,
+				      u64 physical);
 
 #endif
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index aa1b36cf5c88..d0d7db3c8b0b 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -3500,6 +3500,17 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx,
 		if (!cache)
 			goto skip;
 
+
+		if (sctx->is_dev_replace && btrfs_fs_incompat(fs_info, ZONED)) {
+			spin_lock(&cache->lock);
+			if (!cache->to_copy) {
+				spin_unlock(&cache->lock);
+				ro_set = 0;
+				goto done;
+			}
+			spin_unlock(&cache->lock);
+		}
+
 		/*
 		 * Make sure that while we are scrubbing the corresponding block
 		 * group doesn't get its logical address and its device extents
@@ -3631,6 +3642,12 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx,
 
 		scrub_pause_off(fs_info);
 
+		if (sctx->is_dev_replace &&
+		    !btrfs_finish_block_group_to_copy(dev_replace->srcdev,
+						      cache, found_key.offset))
+			ro_set = 0;
+
+done:
 		down_write(&dev_replace->rwsem);
 		dev_replace->cursor_left = dev_replace->cursor_right;
 		dev_replace->item_needs_writeback = 1;
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 32/41] btrfs: implement cloning for ZONED device-replace
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (29 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 31/41] btrfs: mark block groups to copy for device-replace Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 17:15     ` Josef Bacik
  2020-10-30 13:51   ` [PATCH v9 33/41] btrfs: implement copying " Naohiro Aota
                     ` (9 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

This is 2/4 patch to implement device-replace for ZONED mode.

On zoned mode, a block group must be either copied (from the source device
to the destination device) or cloned (to the both device).

This commit implements the cloning part. If a block group targeted by an IO
is marked to copy, we should not clone the IO to the destination device,
because the block group is eventually copied by the replace process.

This commit also handles cloning of device reset.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/dev-replace.c |  4 ++--
 fs/btrfs/extent-tree.c | 20 ++++++++++++++++++--
 fs/btrfs/scrub.c       |  2 +-
 fs/btrfs/volumes.c     | 33 +++++++++++++++++++++++++++++++--
 fs/btrfs/zoned.c       | 11 +++++++++++
 5 files changed, 63 insertions(+), 7 deletions(-)

diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index e86aff38aea4..848f8063dc1c 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -454,7 +454,7 @@ static int mark_block_group_to_copy(struct btrfs_fs_info *fs_info,
 	u64 chunk_offset, length;
 
 	/* Do not use "to_copy" on non-ZONED for now */
-	if (!btrfs_fs_incompat(fs_info, ZONED))
+	if (!btrfs_is_zoned(fs_info))
 		return 0;
 
 	mutex_lock(&fs_info->chunk_mutex);
@@ -565,7 +565,7 @@ bool btrfs_finish_block_group_to_copy(struct btrfs_device *srcdev,
 	int i;
 
 	/* Do not use "to_copy" on non-ZONED for now */
-	if (!btrfs_fs_incompat(fs_info, ZONED))
+	if (!btrfs_is_zoned(fs_info))
 		return true;
 
 	spin_lock(&cache->lock);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 57454ef4c91e..1bb95d5aaed2 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -35,6 +35,7 @@
 #include "discard.h"
 #include "rcu-string.h"
 #include "zoned.h"
+#include "dev-replace.h"
 
 #undef SCRAMBLE_DELAYED_REFS
 
@@ -1336,6 +1337,8 @@ int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
 			u64 length = stripe->length;
 			u64 bytes;
 			struct request_queue *req_q;
+			struct btrfs_dev_replace *dev_replace =
+				&fs_info->dev_replace;
 
 			if (!stripe->dev->bdev) {
 				ASSERT(btrfs_test_opt(fs_info, DEGRADED));
@@ -1344,15 +1347,28 @@ int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
 
 			req_q = bdev_get_queue(stripe->dev->bdev);
 			/* zone reset in ZONED mode */
-			if (btrfs_can_zone_reset(dev, physical, length))
+			if (btrfs_can_zone_reset(dev, physical, length)) {
 				ret = btrfs_reset_device_zone(dev, physical,
 							      length, &bytes);
-			else if (blk_queue_discard(req_q))
+				if (ret)
+					goto next;
+				if (!btrfs_dev_replace_is_ongoing(
+					    dev_replace) ||
+				    dev != dev_replace->srcdev)
+					goto next;
+
+				discarded_bytes += bytes;
+				/* send to replace target as well */
+				ret = btrfs_reset_device_zone(
+					dev_replace->tgtdev,
+					physical, length, &bytes);
+			} else if (blk_queue_discard(req_q))
 				ret = btrfs_issue_discard(dev->bdev, physical,
 							  length, &bytes);
 			else
 				continue;
 
+next:
 			if (!ret) {
 				discarded_bytes += bytes;
 			} else if (ret != -EOPNOTSUPP) {
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index d0d7db3c8b0b..371bb6437cab 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -3501,7 +3501,7 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx,
 			goto skip;
 
 
-		if (sctx->is_dev_replace && btrfs_fs_incompat(fs_info, ZONED)) {
+		if (sctx->is_dev_replace && btrfs_is_zoned(fs_info)) {
 			spin_lock(&cache->lock);
 			if (!cache->to_copy) {
 				spin_unlock(&cache->lock);
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 26669007d367..920292d0fca7 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -5964,9 +5964,29 @@ static int get_extra_mirror_from_replace(struct btrfs_fs_info *fs_info,
 	return ret;
 }
 
+static bool is_block_group_to_copy(struct btrfs_fs_info *fs_info, u64 logical)
+{
+	struct btrfs_block_group *cache;
+	bool ret;
+
+	/* non-ZONED mode does not use "to_copy" flag */
+	if (!btrfs_is_zoned(fs_info))
+		return false;
+
+	cache = btrfs_lookup_block_group(fs_info, logical);
+
+	spin_lock(&cache->lock);
+	ret = cache->to_copy;
+	spin_unlock(&cache->lock);
+
+	btrfs_put_block_group(cache);
+	return ret;
+}
+
 static void handle_ops_on_dev_replace(enum btrfs_map_op op,
 				      struct btrfs_bio **bbio_ret,
 				      struct btrfs_dev_replace *dev_replace,
+				      u64 logical,
 				      int *num_stripes_ret, int *max_errors_ret)
 {
 	struct btrfs_bio *bbio = *bbio_ret;
@@ -5979,6 +5999,15 @@ static void handle_ops_on_dev_replace(enum btrfs_map_op op,
 	if (op == BTRFS_MAP_WRITE) {
 		int index_where_to_add;
 
+		/*
+		 * a block group which have "to_copy" set will
+		 * eventually copied by dev-replace process. We can
+		 * avoid cloning IO here.
+		 */
+		if (is_block_group_to_copy(dev_replace->srcdev->fs_info,
+					   logical))
+			return;
+
 		/*
 		 * duplicate the write operations while the dev replace
 		 * procedure is running. Since the copying of the old disk to
@@ -6374,8 +6403,8 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
 
 	if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL &&
 	    need_full_stripe(op)) {
-		handle_ops_on_dev_replace(op, &bbio, dev_replace, &num_stripes,
-					  &max_errors);
+		handle_ops_on_dev_replace(op, &bbio, dev_replace, logical,
+					  &num_stripes, &max_errors);
 	}
 
 	*bbio_ret = bbio;
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index 15bc7d451348..f672465d1bb1 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -11,6 +11,7 @@
 #include "disk-io.h"
 #include "block-group.h"
 #include "transaction.h"
+#include "dev-replace.h"
 
 /* Maximum number of zones to report per blkdev_report_zones() call */
 #define BTRFS_REPORT_NR_ZONES   4096
@@ -890,6 +891,8 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache)
 	for (i = 0; i < map->num_stripes; i++) {
 		bool is_sequential;
 		struct blk_zone zone;
+		struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
+		int dev_replace_is_ongoing = 0;
 
 		device = map->stripes[i].dev;
 		physical = map->stripes[i].physical;
@@ -916,6 +919,14 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache)
 		 */
 		btrfs_dev_clear_zone_empty(device, physical);
 
+		down_read(&dev_replace->rwsem);
+		dev_replace_is_ongoing =
+			btrfs_dev_replace_is_ongoing(dev_replace);
+		if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL)
+			btrfs_dev_clear_zone_empty(dev_replace->tgtdev,
+						   physical);
+		up_read(&dev_replace->rwsem);
+
 		/*
 		 * The group is mapped to a sequential zone. Get the zone write
 		 * pointer to determine the allocation offset within the zone.
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 33/41] btrfs: implement copying for ZONED device-replace
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (30 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 32/41] btrfs: implement cloning for ZONED device-replace Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 17:19     ` Josef Bacik
  2020-10-30 13:51   ` [PATCH v9 34/41] btrfs: support dev-replace in ZONED mode Naohiro Aota
                     ` (8 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

This is 3/4 patch to implement device-replace on ZONED mode.

This commit implement copying. So, it track the write pointer during device
replace process. Device-replace's copying is smart to copy only used
extents on source device, we have to fill the gap to honor the sequential
write rule in the target device.

Device-replace process in ZONED mode must copy or clone all the extents in
the source device exactly once.  So, we need to use to ensure allocations
started just before the dev-replace process to have their corresponding
extent information in the B-trees. finish_extent_writes_for_zoned()
implements that functionality, which basically is the removed code in the
commit 042528f8d840 ("Btrfs: fix block group remaining RO forever after
error during device replace").

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/scrub.c | 86 ++++++++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/zoned.c | 12 +++++++
 fs/btrfs/zoned.h |  7 ++++
 3 files changed, 105 insertions(+)

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 371bb6437cab..aaf7882dee06 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -169,6 +169,7 @@ struct scrub_ctx {
 	int			pages_per_rd_bio;
 
 	int			is_dev_replace;
+	u64			write_pointer;
 
 	struct scrub_bio        *wr_curr_bio;
 	struct mutex            wr_lock;
@@ -1623,6 +1624,25 @@ static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
 	return scrub_add_page_to_wr_bio(sblock->sctx, spage);
 }
 
+static int fill_writer_pointer_gap(struct scrub_ctx *sctx, u64 physical)
+{
+	int ret = 0;
+	u64 length;
+
+	if (!btrfs_is_zoned(sctx->fs_info))
+		return 0;
+
+	if (sctx->write_pointer < physical) {
+		length = physical - sctx->write_pointer;
+
+		ret = btrfs_zoned_issue_zeroout(sctx->wr_tgtdev,
+						sctx->write_pointer, length);
+		if (!ret)
+			sctx->write_pointer = physical;
+	}
+	return ret;
+}
+
 static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
 				    struct scrub_page *spage)
 {
@@ -1645,6 +1665,13 @@ static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
 	if (sbio->page_count == 0) {
 		struct bio *bio;
 
+		ret = fill_writer_pointer_gap(sctx,
+					      spage->physical_for_dev_replace);
+		if (ret) {
+			mutex_unlock(&sctx->wr_lock);
+			return ret;
+		}
+
 		sbio->physical = spage->physical_for_dev_replace;
 		sbio->logical = spage->logical;
 		sbio->dev = sctx->wr_tgtdev;
@@ -1706,6 +1733,10 @@ static void scrub_wr_submit(struct scrub_ctx *sctx)
 	 * doubled the write performance on spinning disks when measured
 	 * with Linux 3.5 */
 	btrfsic_submit_bio(sbio->bio);
+
+	if (btrfs_is_zoned(sctx->fs_info))
+		sctx->write_pointer = sbio->physical +
+			sbio->page_count * PAGE_SIZE;
 }
 
 static void scrub_wr_bio_end_io(struct bio *bio)
@@ -2973,6 +3004,21 @@ static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
 	return ret < 0 ? ret : 0;
 }
 
+static void sync_replace_for_zoned(struct scrub_ctx *sctx)
+{
+	if (!btrfs_is_zoned(sctx->fs_info))
+		return;
+
+	sctx->flush_all_writes = true;
+	scrub_submit(sctx);
+	mutex_lock(&sctx->wr_lock);
+	scrub_wr_submit(sctx);
+	mutex_unlock(&sctx->wr_lock);
+
+	wait_event(sctx->list_wait,
+		   atomic_read(&sctx->bios_in_flight) == 0);
+}
+
 static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 					   struct map_lookup *map,
 					   struct btrfs_device *scrub_dev,
@@ -3105,6 +3151,14 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 	 */
 	blk_start_plug(&plug);
 
+	if (sctx->is_dev_replace &&
+	    btrfs_dev_is_sequential(sctx->wr_tgtdev, physical)) {
+		mutex_lock(&sctx->wr_lock);
+		sctx->write_pointer = physical;
+		mutex_unlock(&sctx->wr_lock);
+		sctx->flush_all_writes = true;
+	}
+
 	/*
 	 * now find all extents for each stripe and scrub them
 	 */
@@ -3292,6 +3346,9 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 			if (ret)
 				goto out;
 
+			if (sctx->is_dev_replace)
+				sync_replace_for_zoned(sctx);
+
 			if (extent_logical + extent_len <
 			    key.objectid + bytes) {
 				if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
@@ -3414,6 +3471,25 @@ static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
 	return ret;
 }
 
+static int finish_extent_writes_for_zoned(struct btrfs_root *root,
+					  struct btrfs_block_group *cache)
+{
+	struct btrfs_fs_info *fs_info = cache->fs_info;
+	struct btrfs_trans_handle *trans;
+
+	if (!btrfs_is_zoned(fs_info))
+		return 0;
+
+	btrfs_wait_block_group_reservations(cache);
+	btrfs_wait_nocow_writers(cache);
+	btrfs_wait_ordered_roots(fs_info, U64_MAX, cache->start, cache->length);
+
+	trans = btrfs_join_transaction(root);
+	if (IS_ERR(trans))
+		return PTR_ERR(trans);
+	return btrfs_commit_transaction(trans);
+}
+
 static noinline_for_stack
 int scrub_enumerate_chunks(struct scrub_ctx *sctx,
 			   struct btrfs_device *scrub_dev, u64 start, u64 end)
@@ -3569,6 +3645,16 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx,
 		 * group is not RO.
 		 */
 		ret = btrfs_inc_block_group_ro(cache, sctx->is_dev_replace);
+		if (!ret && sctx->is_dev_replace) {
+			ret = finish_extent_writes_for_zoned(root, cache);
+			if (ret) {
+				btrfs_dec_block_group_ro(cache);
+				scrub_pause_off(fs_info);
+				btrfs_put_block_group(cache);
+				break;
+			}
+		}
+
 		if (ret == 0) {
 			ro_set = 1;
 		} else if (ret == -ENOSPC && !sctx->is_dev_replace) {
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index f672465d1bb1..1b080184440d 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -1181,3 +1181,15 @@ void btrfs_revert_meta_write_pointer(struct btrfs_block_group *cache,
 	ASSERT(cache->meta_write_pointer == eb->start + eb->len);
 	cache->meta_write_pointer = eb->start;
 }
+
+int btrfs_zoned_issue_zeroout(struct btrfs_device *device, u64 physical,
+			      u64 length)
+{
+	if (!btrfs_dev_is_sequential(device, physical))
+		return -EOPNOTSUPP;
+
+	return blkdev_issue_zeroout(device->bdev,
+				    physical >> SECTOR_SHIFT,
+				    length >> SECTOR_SHIFT,
+				    GFP_NOFS, 0);
+}
diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h
index 262b248a9085..fb4f1cfce1e5 100644
--- a/fs/btrfs/zoned.h
+++ b/fs/btrfs/zoned.h
@@ -52,6 +52,8 @@ bool btrfs_check_meta_write_pointer(struct btrfs_fs_info *fs_info,
 				    struct btrfs_block_group **cache_ret);
 void btrfs_revert_meta_write_pointer(struct btrfs_block_group *cache,
 				     struct extent_buffer *eb);
+int btrfs_zoned_issue_zeroout(struct btrfs_device *device, u64 physical,
+			      u64 length);
 #else /* CONFIG_BLK_DEV_ZONED */
 static inline int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
 				     struct blk_zone *zone)
@@ -139,6 +141,11 @@ btrfs_revert_meta_write_pointer(struct btrfs_block_group *cache,
 				struct extent_buffer *eb)
 {
 }
+static inline int btrfs_zoned_issue_zeroout(struct btrfs_device *device,
+					    u64 physical, u64 length)
+{
+	return -EOPNOTSUPP;
+}
 #endif
 
 static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos)
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 34/41] btrfs: support dev-replace in ZONED mode
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (31 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 33/41] btrfs: implement copying " Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 20:34     ` Josef Bacik
  2020-10-30 13:51   ` [PATCH v9 35/41] btrfs: enable relocation " Naohiro Aota
                     ` (7 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

This is 4/4 patch to implement device-replace on ZONED mode.

Even after the copying is done, the write pointers of the source device and
the destination device may not be synchronized. For example, when the last
allocated extent is freed before device-replace process, the extent is not
copied, leaving a hole there.

This patch synchronize the write pointers by writing zeros to the
destination device.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/scrub.c | 36 +++++++++++++++++++++++++
 fs/btrfs/zoned.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/zoned.h |  8 ++++++
 3 files changed, 113 insertions(+)

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index aaf7882dee06..0e2211b9c810 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -3019,6 +3019,31 @@ static void sync_replace_for_zoned(struct scrub_ctx *sctx)
 		   atomic_read(&sctx->bios_in_flight) == 0);
 }
 
+static int sync_write_pointer_for_zoned(struct scrub_ctx *sctx, u64 logical,
+					u64 physical, u64 physical_end)
+{
+	struct btrfs_fs_info *fs_info = sctx->fs_info;
+	int ret = 0;
+
+	if (!btrfs_is_zoned(fs_info))
+		return 0;
+
+	wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
+
+	mutex_lock(&sctx->wr_lock);
+	if (sctx->write_pointer < physical_end) {
+		ret = btrfs_sync_zone_write_pointer(sctx->wr_tgtdev, logical,
+						    physical,
+						    sctx->write_pointer);
+		if (ret)
+			btrfs_err(fs_info, "failed to recover write pointer");
+	}
+	mutex_unlock(&sctx->wr_lock);
+	btrfs_dev_clear_zone_empty(sctx->wr_tgtdev, physical);
+
+	return ret;
+}
+
 static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 					   struct map_lookup *map,
 					   struct btrfs_device *scrub_dev,
@@ -3416,6 +3441,17 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 	blk_finish_plug(&plug);
 	btrfs_free_path(path);
 	btrfs_free_path(ppath);
+
+	if (sctx->is_dev_replace && ret >= 0) {
+		int ret2;
+
+		ret2 = sync_write_pointer_for_zoned(sctx, base + offset,
+						    map->stripes[num].physical,
+						    physical_end);
+		if (ret2)
+			ret = ret2;
+	}
+
 	return ret < 0 ? ret : 0;
 }
 
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index 1b080184440d..f98aa0fae849 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -12,6 +12,7 @@
 #include "block-group.h"
 #include "transaction.h"
 #include "dev-replace.h"
+#include "space-info.h"
 
 /* Maximum number of zones to report per blkdev_report_zones() call */
 #define BTRFS_REPORT_NR_ZONES   4096
@@ -1193,3 +1194,71 @@ int btrfs_zoned_issue_zeroout(struct btrfs_device *device, u64 physical,
 				    length >> SECTOR_SHIFT,
 				    GFP_NOFS, 0);
 }
+
+static int read_zone_info(struct btrfs_fs_info *fs_info, u64 logical,
+			  struct blk_zone *zone)
+{
+	struct btrfs_bio *bbio = NULL;
+	u64 mapped_length = PAGE_SIZE;
+	unsigned int nofs_flag;
+	int nmirrors;
+	int i, ret;
+
+	ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS, logical,
+			       &mapped_length, &bbio);
+	if (ret || !bbio || mapped_length < PAGE_SIZE) {
+		btrfs_put_bbio(bbio);
+		return -EIO;
+	}
+
+	if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK)
+		return -EINVAL;
+
+	nofs_flag = memalloc_nofs_save();
+	nmirrors = (int)bbio->num_stripes;
+	for (i = 0; i < nmirrors; i++) {
+		u64 physical = bbio->stripes[i].physical;
+		struct btrfs_device *dev = bbio->stripes[i].dev;
+
+		/* missing device */
+		if (!dev->bdev)
+			continue;
+
+		ret = btrfs_get_dev_zone(dev, physical, zone);
+		/* failing device */
+		if (ret == -EIO || ret == -EOPNOTSUPP)
+			continue;
+		break;
+	}
+	memalloc_nofs_restore(nofs_flag);
+
+	return ret;
+}
+
+int btrfs_sync_zone_write_pointer(struct btrfs_device *tgt_dev, u64 logical,
+				    u64 physical_start, u64 physical_pos)
+{
+	struct btrfs_fs_info *fs_info = tgt_dev->fs_info;
+	struct blk_zone zone;
+	u64 length;
+	u64 wp;
+	int ret;
+
+	if (!btrfs_dev_is_sequential(tgt_dev, physical_pos))
+		return 0;
+
+	ret = read_zone_info(fs_info, logical, &zone);
+	if (ret)
+		return ret;
+
+	wp = physical_start + ((zone.wp - zone.start) << SECTOR_SHIFT);
+
+	if (physical_pos == wp)
+		return 0;
+
+	if (physical_pos > wp)
+		return -EUCLEAN;
+
+	length = wp - physical_pos;
+	return btrfs_zoned_issue_zeroout(tgt_dev, physical_pos, length);
+}
diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h
index fb4f1cfce1e5..bd73f3c48c0c 100644
--- a/fs/btrfs/zoned.h
+++ b/fs/btrfs/zoned.h
@@ -54,6 +54,8 @@ void btrfs_revert_meta_write_pointer(struct btrfs_block_group *cache,
 				     struct extent_buffer *eb);
 int btrfs_zoned_issue_zeroout(struct btrfs_device *device, u64 physical,
 			      u64 length);
+int btrfs_sync_zone_write_pointer(struct btrfs_device *tgt_dev, u64 logical,
+				  u64 physical_start, u64 physical_pos);
 #else /* CONFIG_BLK_DEV_ZONED */
 static inline int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
 				     struct blk_zone *zone)
@@ -146,6 +148,12 @@ static inline int btrfs_zoned_issue_zeroout(struct btrfs_device *device,
 {
 	return -EOPNOTSUPP;
 }
+static inline int btrfs_sync_zone_write_pointer(struct btrfs_device *tgt_dev,
+						u64 logical, u64 physical_start,
+						u64 physical_pos)
+{
+	return -EOPNOTSUPP;
+}
 #endif
 
 static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos)
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 35/41] btrfs: enable relocation in ZONED mode
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (32 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 34/41] btrfs: support dev-replace in ZONED mode Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 20:39     ` Josef Bacik
  2020-10-30 13:51   ` [PATCH v9 36/41] btrfs: relocate block group to repair IO failure in ZONED Naohiro Aota
                     ` (6 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

To serialize allocation and submit_bio, we introduced mutex around them. As
a result, preallocation must be completely disabled to avoid a deadlock.

Since current relocation process relies on preallocation to move file data
extents, it must be handled in another way. In ZONED mode, we just truncate
the inode to the size that we wanted to pre-allocate. Then, we flush dirty
pages on the file before finishing relocation process.
run_delalloc_zoned() will handle all the allocation and submit IOs to the
underlying layers.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/relocation.c | 35 +++++++++++++++++++++++++++++++++--
 1 file changed, 33 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 3602806d71bd..44b697b881b6 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -2603,6 +2603,32 @@ static noinline_for_stack int prealloc_file_extent_cluster(
 	if (ret)
 		return ret;
 
+	/*
+	 * In ZONED mode, we cannot preallocate the file region. Instead, we
+	 * dirty and fiemap_write the region.
+	 */
+
+	if (btrfs_is_zoned(inode->root->fs_info)) {
+		struct btrfs_root *root = inode->root;
+		struct btrfs_trans_handle *trans;
+
+		end = cluster->end - offset + 1;
+		trans = btrfs_start_transaction(root, 1);
+		if (IS_ERR(trans))
+			return PTR_ERR(trans);
+
+		inode->vfs_inode.i_ctime = current_time(&inode->vfs_inode);
+		i_size_write(&inode->vfs_inode, end);
+		ret = btrfs_update_inode(trans, root, &inode->vfs_inode);
+		if (ret) {
+			btrfs_abort_transaction(trans, ret);
+			btrfs_end_transaction(trans);
+			return ret;
+		}
+
+		return btrfs_end_transaction(trans);
+	}
+
 	inode_lock(&inode->vfs_inode);
 	for (nr = 0; nr < cluster->nr; nr++) {
 		start = cluster->boundary[nr] - offset;
@@ -2799,6 +2825,8 @@ static int relocate_file_extent_cluster(struct inode *inode,
 		}
 	}
 	WARN_ON(nr != cluster->nr);
+	if (btrfs_is_zoned(fs_info) && !ret)
+		ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
 out:
 	kfree(ra);
 	return ret;
@@ -3434,8 +3462,12 @@ static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
 	struct btrfs_path *path;
 	struct btrfs_inode_item *item;
 	struct extent_buffer *leaf;
+	u64 flags = BTRFS_INODE_NOCOMPRESS | BTRFS_INODE_PREALLOC;
 	int ret;
 
+	if (btrfs_is_zoned(trans->fs_info))
+		flags &= ~BTRFS_INODE_PREALLOC;
+
 	path = btrfs_alloc_path();
 	if (!path)
 		return -ENOMEM;
@@ -3450,8 +3482,7 @@ static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
 	btrfs_set_inode_generation(leaf, item, 1);
 	btrfs_set_inode_size(leaf, item, 0);
 	btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
-	btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS |
-					  BTRFS_INODE_PREALLOC);
+	btrfs_set_inode_flags(leaf, item, flags);
 	btrfs_mark_buffer_dirty(leaf);
 out:
 	btrfs_free_path(path);
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 36/41] btrfs: relocate block group to repair IO failure in ZONED
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (33 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 35/41] btrfs: enable relocation " Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-10-30 13:51   ` [PATCH v9 37/41] btrfs: split alloc_log_tree() Naohiro Aota
                     ` (5 subsequent siblings)
  40 siblings, 0 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota, Josef Bacik

When btrfs find a checksum error and if the file system has a mirror of the
damaged data, btrfs read the correct data from the mirror and write the
data to damaged blocks. This repairing, however, is against the sequential
write required rule.

We can consider three methods to repair an IO failure in ZONED mode:
(1) Reset and rewrite the damaged zone
(2) Allocate new device extent and replace the damaged device extent to the
    new extent
(3) Relocate the corresponding block group

Method (1) is most similar to a behavior done with regular devices.
However, it also wipes non-damaged data in the same device extent, and so
it unnecessary degrades non-damaged data.

Method (2) is much like device replacing but done in the same device. It is
safe because it keeps the device extent until the replacing finish.
However, extending device replacing is non-trivial. It assumes
"src_dev->physical == dst_dev->physical". Also, the extent mapping
replacing function should be extended to support replacing device extent
position in one device.

Method (3) invokes relocation of the damaged block group, so it is
straightforward to implement. It relocates all the mirrored device extents,
so it is, potentially, a more costly operation than method (1) or (2). But
it relocates only using extents which reduce the total IO size.

Let's apply method (3) for now. In the future, we can extend device-replace
and apply method (2).

For protecting a block group gets relocated multiple time with multiple IO
errors, this commit introduces "relocating_repair" bit to show it's now
relocating to repair IO failures. Also it uses a new kthread
"btrfs-relocating-repair", not to block IO path with relocating process.

This commit also supports repairing in the scrub process.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/block-group.h |  1 +
 fs/btrfs/extent_io.c   |  3 ++
 fs/btrfs/scrub.c       |  3 ++
 fs/btrfs/volumes.c     | 71 ++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/volumes.h     |  1 +
 5 files changed, 79 insertions(+)

diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index e91123495d68..50e5ddb0a19b 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -96,6 +96,7 @@ struct btrfs_block_group {
 	unsigned int has_caching_ctl:1;
 	unsigned int removed:1;
 	unsigned int to_copy:1;
+	unsigned int relocating_repair:1;
 
 	int disk_cache_state;
 
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 3cce444d5dbb..8ab5161a68b4 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2268,6 +2268,9 @@ int repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,
 	ASSERT(!(fs_info->sb->s_flags & SB_RDONLY));
 	BUG_ON(!mirror_num);
 
+	if (btrfs_is_zoned(fs_info))
+		return btrfs_repair_one_zone(fs_info, logical);
+
 	bio = btrfs_io_bio_alloc(1);
 	bio->bi_iter.bi_size = 0;
 	map_length = length;
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 0e2211b9c810..e6a8df8a8f4f 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -861,6 +861,9 @@ static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
 	have_csum = sblock_to_check->pagev[0]->have_csum;
 	dev = sblock_to_check->pagev[0]->dev;
 
+	if (btrfs_is_zoned(fs_info) && !sctx->is_dev_replace)
+		return btrfs_repair_one_zone(fs_info, logical);
+
 	/*
 	 * We must use GFP_NOFS because the scrub task might be waiting for a
 	 * worker task executing this function and in turn a transaction commit
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 920292d0fca7..10e678f88f2a 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -7973,3 +7973,74 @@ bool btrfs_pinned_by_swapfile(struct btrfs_fs_info *fs_info, void *ptr)
 	spin_unlock(&fs_info->swapfile_pins_lock);
 	return node != NULL;
 }
+
+static int relocating_repair_kthread(void *data)
+{
+	struct btrfs_block_group *cache = (struct btrfs_block_group *) data;
+	struct btrfs_fs_info *fs_info = cache->fs_info;
+	u64 target;
+	int ret = 0;
+
+	target = cache->start;
+	btrfs_put_block_group(cache);
+
+	if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE)) {
+		btrfs_info(fs_info,
+			   "skip relocating block group %llu to repair: EBUSY",
+			   target);
+		return -EBUSY;
+	}
+
+	mutex_lock(&fs_info->delete_unused_bgs_mutex);
+
+	/* ensure Block Group still exists */
+	cache = btrfs_lookup_block_group(fs_info, target);
+	if (!cache)
+		goto out;
+
+	if (!cache->relocating_repair)
+		goto out;
+
+	ret = btrfs_may_alloc_data_chunk(fs_info, target);
+	if (ret < 0)
+		goto out;
+
+	btrfs_info(fs_info, "relocating block group %llu to repair IO failure",
+		   target);
+	ret = btrfs_relocate_chunk(fs_info, target);
+
+out:
+	if (cache)
+		btrfs_put_block_group(cache);
+	mutex_unlock(&fs_info->delete_unused_bgs_mutex);
+	btrfs_exclop_finish(fs_info);
+
+	return ret;
+}
+
+int btrfs_repair_one_zone(struct btrfs_fs_info *fs_info, u64 logical)
+{
+	struct btrfs_block_group *cache;
+
+	/* do not attempt to repair in degraded state */
+	if (btrfs_test_opt(fs_info, DEGRADED))
+		return 0;
+
+	cache = btrfs_lookup_block_group(fs_info, logical);
+	if (!cache)
+		return 0;
+
+	spin_lock(&cache->lock);
+	if (cache->relocating_repair) {
+		spin_unlock(&cache->lock);
+		btrfs_put_block_group(cache);
+		return 0;
+	}
+	cache->relocating_repair = 1;
+	spin_unlock(&cache->lock);
+
+	kthread_run(relocating_repair_kthread, cache,
+		    "btrfs-relocating-repair");
+
+	return 0;
+}
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index cff1f7689eac..7c1ad6901791 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -584,5 +584,6 @@ void btrfs_scratch_superblocks(struct btrfs_fs_info *fs_info,
 int btrfs_bg_type_to_factor(u64 flags);
 const char *btrfs_bg_type_to_raid_name(u64 flags);
 int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info);
+int btrfs_repair_one_zone(struct btrfs_fs_info *fs_info, u64 logical);
 
 #endif
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 37/41] btrfs: split alloc_log_tree()
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (34 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 36/41] btrfs: relocate block group to repair IO failure in ZONED Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 20:42     ` Josef Bacik
  2020-10-30 13:51   ` [PATCH v9 38/41] btrfs: extend zoned allocator to use dedicated tree-log block group Naohiro Aota
                     ` (4 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba
  Cc: hare, linux-fsdevel, Naohiro Aota, Johannes Thumshirn

This is a preparation for the next patch. This commit split
alloc_log_tree() to allocating tree structure part (remains in
alloc_log_tree()) and allocating tree node part (moved in
btrfs_alloc_log_tree_node()). The latter part is also exported to be used
in the next patch.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/disk-io.c | 31 +++++++++++++++++++++++++------
 fs/btrfs/disk-io.h |  2 ++
 2 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 2b30ef8a7034..70885f3d3321 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1211,7 +1211,6 @@ static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
 					 struct btrfs_fs_info *fs_info)
 {
 	struct btrfs_root *root;
-	struct extent_buffer *leaf;
 
 	root = btrfs_alloc_root(fs_info, BTRFS_TREE_LOG_OBJECTID, GFP_NOFS);
 	if (!root)
@@ -1221,6 +1220,14 @@ static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
 	root->root_key.type = BTRFS_ROOT_ITEM_KEY;
 	root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
 
+	return root;
+}
+
+int btrfs_alloc_log_tree_node(struct btrfs_trans_handle *trans,
+			      struct btrfs_root *root)
+{
+	struct extent_buffer *leaf;
+
 	/*
 	 * DON'T set SHAREABLE bit for log trees.
 	 *
@@ -1233,26 +1240,31 @@ static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
 
 	leaf = btrfs_alloc_tree_block(trans, root, 0, BTRFS_TREE_LOG_OBJECTID,
 			NULL, 0, 0, 0, BTRFS_NESTING_NORMAL);
-	if (IS_ERR(leaf)) {
-		btrfs_put_root(root);
-		return ERR_CAST(leaf);
-	}
+	if (IS_ERR(leaf))
+		return PTR_ERR(leaf);
 
 	root->node = leaf;
 
 	btrfs_mark_buffer_dirty(root->node);
 	btrfs_tree_unlock(root->node);
-	return root;
+
+	return 0;
 }
 
 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
 			     struct btrfs_fs_info *fs_info)
 {
 	struct btrfs_root *log_root;
+	int ret;
 
 	log_root = alloc_log_tree(trans, fs_info);
 	if (IS_ERR(log_root))
 		return PTR_ERR(log_root);
+	ret = btrfs_alloc_log_tree_node(trans, log_root);
+	if (ret) {
+		kfree(log_root);
+		return ret;
+	}
 	WARN_ON(fs_info->log_root_tree);
 	fs_info->log_root_tree = log_root;
 	return 0;
@@ -1264,11 +1276,18 @@ int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_root *log_root;
 	struct btrfs_inode_item *inode_item;
+	int ret;
 
 	log_root = alloc_log_tree(trans, fs_info);
 	if (IS_ERR(log_root))
 		return PTR_ERR(log_root);
 
+	ret = btrfs_alloc_log_tree_node(trans, log_root);
+	if (ret) {
+		btrfs_put_root(log_root);
+		return ret;
+	}
+
 	log_root->last_trans = trans->transid;
 	log_root->root_key.offset = root->root_key.objectid;
 
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index fee69ced58b4..b82ae3711c42 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -115,6 +115,8 @@ blk_status_t btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
 			extent_submit_bio_start_t *submit_bio_start);
 blk_status_t btrfs_submit_bio_done(void *private_data, struct bio *bio,
 			  int mirror_num);
+int btrfs_alloc_log_tree_node(struct btrfs_trans_handle *trans,
+			      struct btrfs_root *root);
 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
 			     struct btrfs_fs_info *fs_info);
 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 38/41] btrfs: extend zoned allocator to use dedicated tree-log block group
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (35 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 37/41] btrfs: split alloc_log_tree() Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 20:47     ` Josef Bacik
  2020-10-30 13:51   ` [PATCH v9 39/41] btrfs: serialize log transaction on ZONED mode Naohiro Aota
                     ` (3 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba
  Cc: hare, linux-fsdevel, Naohiro Aota, Johannes Thumshirn

This is the 1/3 patch to enable tree log on ZONED mode.

The tree-log feature does not work on ZONED mode as is. Blocks for a
tree-log tree are allocated mixed with other metadata blocks, and btrfs
writes and syncs the tree-log blocks to devices at the time of fsync(),
which is different timing from a global transaction commit. As a result,
both writing tree-log blocks and writing other metadata blocks become
non-sequential writes that ZONED mode must avoid.

We can introduce a dedicated block group for tree-log blocks so that
tree-log blocks and other metadata blocks can be separated write streams.
As a result, each write stream can now be written to devices separately.
"fs_info->treelog_bg" tracks the dedicated block group and btrfs assign
"treelog_bg" on-demand on tree-log block allocation time.

This commit extends the zoned block allocator to use the block group.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/block-group.c |  7 +++++
 fs/btrfs/ctree.h       |  2 ++
 fs/btrfs/extent-tree.c | 63 +++++++++++++++++++++++++++++++++++++++---
 3 files changed, 68 insertions(+), 4 deletions(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index 21e40046dce1..ac4fb954db28 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -939,6 +939,13 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 	btrfs_return_cluster_to_free_space(block_group, cluster);
 	spin_unlock(&cluster->refill_lock);
 
+	if (btrfs_is_zoned(fs_info)) {
+		spin_lock(&fs_info->treelog_bg_lock);
+		if (fs_info->treelog_bg == block_group->start)
+			fs_info->treelog_bg = 0;
+		spin_unlock(&fs_info->treelog_bg_lock);
+	}
+
 	path = btrfs_alloc_path();
 	if (!path) {
 		ret = -ENOMEM;
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 736f679f1310..026d34c8f2ee 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -956,6 +956,8 @@ struct btrfs_fs_info {
 	/* max size to emit ZONE_APPEND write command */
 	u64 max_zone_append_size;
 	struct mutex zoned_meta_io_lock;
+	spinlock_t treelog_bg_lock;
+	u64 treelog_bg;
 
 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
 	spinlock_t ref_verify_lock;
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 1bb95d5aaed2..c570fe576fb3 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3619,6 +3619,9 @@ struct find_free_extent_ctl {
 	bool have_caching_bg;
 	bool orig_have_caching_bg;
 
+	/* Allocation is called for tree-log */
+	bool for_treelog;
+
 	/* RAID index, converted from flags */
 	int index;
 
@@ -3856,23 +3859,54 @@ static int do_allocation_zoned(struct btrfs_block_group *block_group,
 			       struct find_free_extent_ctl *ffe_ctl,
 			       struct btrfs_block_group **bg_ret)
 {
+	struct btrfs_fs_info *fs_info = block_group->fs_info;
 	struct btrfs_space_info *space_info = block_group->space_info;
 	struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
 	u64 start = block_group->start;
 	u64 num_bytes = ffe_ctl->num_bytes;
 	u64 avail;
+	u64 bytenr = block_group->start;
+	u64 log_bytenr;
 	int ret = 0;
+	bool skip;
 
 	ASSERT(btrfs_is_zoned(block_group->fs_info));
 
+	/*
+	 * Do not allow non-tree-log blocks in the dedicated tree-log block
+	 * group, and vice versa.
+	 */
+	spin_lock(&fs_info->treelog_bg_lock);
+	log_bytenr = fs_info->treelog_bg;
+	skip = log_bytenr && ((ffe_ctl->for_treelog && bytenr != log_bytenr) ||
+			      (!ffe_ctl->for_treelog && bytenr == log_bytenr));
+	spin_unlock(&fs_info->treelog_bg_lock);
+	if (skip)
+		return 1;
+
 	spin_lock(&space_info->lock);
 	spin_lock(&block_group->lock);
+	spin_lock(&fs_info->treelog_bg_lock);
+
+	ASSERT(!ffe_ctl->for_treelog ||
+	       block_group->start == fs_info->treelog_bg ||
+	       fs_info->treelog_bg == 0);
 
 	if (block_group->ro) {
 		ret = 1;
 		goto out;
 	}
 
+	/*
+	 * Do not allow currently using block group to be tree-log dedicated
+	 * block group.
+	 */
+	if (ffe_ctl->for_treelog && !fs_info->treelog_bg &&
+	    (block_group->used || block_group->reserved)) {
+		ret = 1;
+		goto out;
+	}
+
 	avail = block_group->length - block_group->alloc_offset;
 	if (avail < num_bytes) {
 		ffe_ctl->max_extent_size = avail;
@@ -3880,6 +3914,9 @@ static int do_allocation_zoned(struct btrfs_block_group *block_group,
 		goto out;
 	}
 
+	if (ffe_ctl->for_treelog && !fs_info->treelog_bg)
+		fs_info->treelog_bg = block_group->start;
+
 	ffe_ctl->found_offset = start + block_group->alloc_offset;
 	block_group->alloc_offset += num_bytes;
 	spin_lock(&ctl->tree_lock);
@@ -3894,6 +3931,9 @@ static int do_allocation_zoned(struct btrfs_block_group *block_group,
 	ffe_ctl->search_start = ffe_ctl->found_offset;
 
 out:
+	if (ret && ffe_ctl->for_treelog)
+		fs_info->treelog_bg = 0;
+	spin_unlock(&fs_info->treelog_bg_lock);
 	spin_unlock(&block_group->lock);
 	spin_unlock(&space_info->lock);
 	return ret;
@@ -4143,7 +4183,12 @@ static int prepare_allocation(struct btrfs_fs_info *fs_info,
 		return prepare_allocation_clustered(fs_info, ffe_ctl,
 						    space_info, ins);
 	case BTRFS_EXTENT_ALLOC_ZONED:
-		/* nothing to do */
+		if (ffe_ctl->for_treelog) {
+			spin_lock(&fs_info->treelog_bg_lock);
+			if (fs_info->treelog_bg)
+				ffe_ctl->hint_byte = fs_info->treelog_bg;
+			spin_unlock(&fs_info->treelog_bg_lock);
+		}
 		return 0;
 	default:
 		BUG();
@@ -4187,6 +4232,7 @@ static noinline int find_free_extent(struct btrfs_root *root,
 	struct find_free_extent_ctl ffe_ctl = {0};
 	struct btrfs_space_info *space_info;
 	bool full_search = false;
+	bool for_treelog = root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID;
 
 	WARN_ON(num_bytes < fs_info->sectorsize);
 
@@ -4200,6 +4246,7 @@ static noinline int find_free_extent(struct btrfs_root *root,
 	ffe_ctl.orig_have_caching_bg = false;
 	ffe_ctl.found_offset = 0;
 	ffe_ctl.hint_byte = hint_byte_orig;
+	ffe_ctl.for_treelog = for_treelog;
 	ffe_ctl.policy = BTRFS_EXTENT_ALLOC_CLUSTERED;
 
 	/* For clustered allocation */
@@ -4274,8 +4321,15 @@ static noinline int find_free_extent(struct btrfs_root *root,
 		struct btrfs_block_group *bg_ret;
 
 		/* If the block group is read-only, we can skip it entirely. */
-		if (unlikely(block_group->ro))
+		if (unlikely(block_group->ro)) {
+			if (btrfs_is_zoned(fs_info) && for_treelog) {
+				spin_lock(&fs_info->treelog_bg_lock);
+				if (block_group->start == fs_info->treelog_bg)
+					fs_info->treelog_bg = 0;
+				spin_unlock(&fs_info->treelog_bg_lock);
+			}
 			continue;
+		}
 
 		btrfs_grab_block_group(block_group, delalloc);
 		ffe_ctl.search_start = block_group->start;
@@ -4463,6 +4517,7 @@ int btrfs_reserve_extent(struct btrfs_root *root, u64 ram_bytes,
 	bool final_tried = num_bytes == min_alloc_size;
 	u64 flags;
 	int ret;
+	bool for_treelog = root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID;
 
 	flags = get_alloc_profile_by_root(root, is_data);
 again:
@@ -4486,8 +4541,8 @@ int btrfs_reserve_extent(struct btrfs_root *root, u64 ram_bytes,
 
 			sinfo = btrfs_find_space_info(fs_info, flags);
 			btrfs_err(fs_info,
-				  "allocation failed flags %llu, wanted %llu",
-				  flags, num_bytes);
+			"allocation failed flags %llu, wanted %llu treelog %d",
+				  flags, num_bytes, for_treelog);
 			if (sinfo)
 				btrfs_dump_space_info(fs_info, sinfo,
 						      num_bytes, 1);
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 39/41] btrfs: serialize log transaction on ZONED mode
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (36 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 38/41] btrfs: extend zoned allocator to use dedicated tree-log block group Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 20:49     ` Josef Bacik
  2020-10-30 13:51   ` [PATCH v9 40/41] btrfs: reorder log node allocation Naohiro Aota
                     ` (2 subsequent siblings)
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota

This is the 2/3 patch to enable tree-log on ZONED mode.

Since we can start more than one log transactions per subvolume
simultaneously, nodes from multiple transactions can be allocated
interleaved. Such mixed allocation results in non-sequential writes at the
time of log transaction commit. The nodes of the global log root tree
(fs_info->log_root_tree), also have the same mixed allocation problem.

This patch serializes log transactions by waiting for a committing
transaction when someone tries to start a new transaction, to avoid the
mixed allocation problem. We must also wait for running log transactions
from another subvolume, but there is no easy way to detect which subvolume
root is running a log transaction. So, this patch forbids starting a new
log transaction when other subvolumes already allocated the global log root
tree.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/tree-log.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 5f585cf57383..826af2ff4740 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -106,6 +106,7 @@ static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
 				       struct btrfs_root *log,
 				       struct btrfs_path *path,
 				       u64 dirid, int del_all);
+static void wait_log_commit(struct btrfs_root *root, int transid);
 
 /*
  * tree logging is a special write ahead log used to make sure that
@@ -140,16 +141,25 @@ static int start_log_trans(struct btrfs_trans_handle *trans,
 			   struct btrfs_log_ctx *ctx)
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
+	bool zoned = btrfs_is_zoned(fs_info);
 	int ret = 0;
 
 	mutex_lock(&root->log_mutex);
 
+again:
 	if (root->log_root) {
+		int index = (root->log_transid + 1) % 2;
+
 		if (btrfs_need_log_full_commit(trans)) {
 			ret = -EAGAIN;
 			goto out;
 		}
 
+		if (zoned && atomic_read(&root->log_commit[index])) {
+			wait_log_commit(root, root->log_transid - 1);
+			goto again;
+		}
+
 		if (!root->log_start_pid) {
 			clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
 			root->log_start_pid = current->pid;
@@ -158,7 +168,9 @@ static int start_log_trans(struct btrfs_trans_handle *trans,
 		}
 	} else {
 		mutex_lock(&fs_info->tree_log_mutex);
-		if (!fs_info->log_root_tree)
+		if (zoned && fs_info->log_root_tree)
+			ret = -EAGAIN;
+		else if (!fs_info->log_root_tree)
 			ret = btrfs_init_log_root_tree(trans, fs_info);
 		mutex_unlock(&fs_info->tree_log_mutex);
 		if (ret)
@@ -193,14 +205,22 @@ static int start_log_trans(struct btrfs_trans_handle *trans,
  */
 static int join_running_log_trans(struct btrfs_root *root)
 {
+	bool zoned = btrfs_is_zoned(root->fs_info);
 	int ret = -ENOENT;
 
 	if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state))
 		return ret;
 
 	mutex_lock(&root->log_mutex);
+again:
 	if (root->log_root) {
+		int index = (root->log_transid + 1) % 2;
+
 		ret = 0;
+		if (zoned && atomic_read(&root->log_commit[index])) {
+			wait_log_commit(root, root->log_transid - 1);
+			goto again;
+		}
 		atomic_inc(&root->log_writers);
 	}
 	mutex_unlock(&root->log_mutex);
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 40/41] btrfs: reorder log node allocation
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (37 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 39/41] btrfs: serialize log transaction on ZONED mode Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-11-03 20:49     ` Josef Bacik
  2020-10-30 13:51   ` [PATCH v9 41/41] btrfs: enable to mount ZONED incompat flag Naohiro Aota
  2020-10-31  3:40   ` [PATCH v9 01/41] block: add bio_add_zone_append_page Jens Axboe
  40 siblings, 1 reply; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba
  Cc: hare, linux-fsdevel, Naohiro Aota, Johannes Thumshirn

This is the 3/3 patch to enable tree-log on ZONED mode.

The allocation order of nodes of "fs_info->log_root_tree" and nodes of
"root->log_root" is not the same as the writing order of them. So, the
writing causes unaligned write errors.

This patch reorders the allocation of them by delaying allocation of the
root node of "fs_info->log_root_tree," so that the node buffers can go out
sequentially to devices.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/disk-io.c  |  6 ------
 fs/btrfs/tree-log.c | 24 ++++++++++++++++++------
 2 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 70885f3d3321..2c2fa5ebfef1 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1255,16 +1255,10 @@ int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
 			     struct btrfs_fs_info *fs_info)
 {
 	struct btrfs_root *log_root;
-	int ret;
 
 	log_root = alloc_log_tree(trans, fs_info);
 	if (IS_ERR(log_root))
 		return PTR_ERR(log_root);
-	ret = btrfs_alloc_log_tree_node(trans, log_root);
-	if (ret) {
-		kfree(log_root);
-		return ret;
-	}
 	WARN_ON(fs_info->log_root_tree);
 	fs_info->log_root_tree = log_root;
 	return 0;
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 826af2ff4740..46ff92a18474 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -3140,6 +3140,16 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
 	list_add_tail(&root_log_ctx.list, &log_root_tree->log_ctxs[index2]);
 	root_log_ctx.log_transid = log_root_tree->log_transid;
 
+	mutex_lock(&fs_info->tree_log_mutex);
+	if (!log_root_tree->node) {
+		ret = btrfs_alloc_log_tree_node(trans, log_root_tree);
+		if (ret) {
+			mutex_unlock(&fs_info->tree_log_mutex);
+			goto out;
+		}
+	}
+	mutex_unlock(&fs_info->tree_log_mutex);
+
 	/*
 	 * Now we are safe to update the log_root_tree because we're under the
 	 * log_mutex, and we're a current writer so we're holding the commit
@@ -3289,12 +3299,14 @@ static void free_log_tree(struct btrfs_trans_handle *trans,
 		.process_func = process_one_buffer
 	};
 
-	ret = walk_log_tree(trans, log, &wc);
-	if (ret) {
-		if (trans)
-			btrfs_abort_transaction(trans, ret);
-		else
-			btrfs_handle_fs_error(log->fs_info, ret, NULL);
+	if (log->node) {
+		ret = walk_log_tree(trans, log, &wc);
+		if (ret) {
+			if (trans)
+				btrfs_abort_transaction(trans, ret);
+			else
+				btrfs_handle_fs_error(log->fs_info, ret, NULL);
+		}
 	}
 
 	clear_extent_bits(&log->dirty_log_pages, 0, (u64)-1,
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* [PATCH v9 41/41] btrfs: enable to mount ZONED incompat flag
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (38 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 40/41] btrfs: reorder log node allocation Naohiro Aota
@ 2020-10-30 13:51   ` Naohiro Aota
  2020-10-31  3:40   ` [PATCH v9 01/41] block: add bio_add_zone_append_page Jens Axboe
  40 siblings, 0 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-10-30 13:51 UTC (permalink / raw)
  To: linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Naohiro Aota, Josef Bacik

This final patch adds the ZONED incompat flag to
BTRFS_FEATURE_INCOMPAT_SUPP and enables btrfs to mount ZONED flagged file
system.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/ctree.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 026d34c8f2ee..c15f73c21f69 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -302,7 +302,8 @@ struct btrfs_super_block {
 	 BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA |	\
 	 BTRFS_FEATURE_INCOMPAT_NO_HOLES	|	\
 	 BTRFS_FEATURE_INCOMPAT_METADATA_UUID	|	\
-	 BTRFS_FEATURE_INCOMPAT_RAID1C34)
+	 BTRFS_FEATURE_INCOMPAT_RAID1C34	|	\
+	 BTRFS_FEATURE_INCOMPAT_ZONED)
 
 #define BTRFS_FEATURE_INCOMPAT_SAFE_SET			\
 	(BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 01/41] block: add bio_add_zone_append_page
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
                     ` (39 preceding siblings ...)
  2020-10-30 13:51   ` [PATCH v9 41/41] btrfs: enable to mount ZONED incompat flag Naohiro Aota
@ 2020-10-31  3:40   ` Jens Axboe
  2020-11-02  5:15     ` Naohiro Aota
  2020-11-02  8:24     ` Johannes Thumshirn
  40 siblings, 2 replies; 119+ messages in thread
From: Jens Axboe @ 2020-10-31  3:40 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba
  Cc: hare, linux-fsdevel, Johannes Thumshirn

On 10/30/20 7:51 AM, Naohiro Aota wrote:
> From: Johannes Thumshirn <johannes.thumshirn@wdc.com>
> 
> Add bio_add_zone_append_page(), a wrapper around bio_add_hw_page() which
> is intended to be used by file systems that directly add pages to a bio
> instead of using bio_iov_iter_get_pages().

Not sure what this is for, since I'm only on one patch in the series...

> +/**
> + * bio_add_zone_append_page - attempt to add page to zone-append bio
> + * @bio: destination bio
> + * @page: page to add
> + * @len: vec entry length
> + * @offset: vec entry offset
> + *
> + * Attempt to add a page to the bio_vec maplist of a bio that will be submitted
> + * for a zone-append request. This can fail for a number of reasons, such as the
> + * bio being full or the target block device is not a zoned block device or
> + * other limitations of the target block device. The target block device must
> + * allow bio's up to PAGE_SIZE, so it is always possible to add a single page
> + * to an empty bio.
> + */

This should include a

Return value:

section, explaining how it returns number of bytes added (and why 0 is thus
a failure case).

> +int bio_add_zone_append_page(struct bio *bio, struct page *page,
> +			     unsigned int len, unsigned int offset)

Should this return unsigned int? If not, how would it work if someone
asked for INT_MAX + 4k.

-- 
Jens Axboe


^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 01/41] block: add bio_add_zone_append_page
  2020-10-31  3:40   ` [PATCH v9 01/41] block: add bio_add_zone_append_page Jens Axboe
@ 2020-11-02  5:15     ` Naohiro Aota
  2020-11-02  8:24     ` Johannes Thumshirn
  1 sibling, 0 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-11-02  5:15 UTC (permalink / raw)
  To: Jens Axboe; +Cc: linux-btrfs, dsterba, hare, linux-fsdevel, Johannes Thumshirn

On Fri, Oct 30, 2020 at 09:40:08PM -0600, Jens Axboe wrote:
>On 10/30/20 7:51 AM, Naohiro Aota wrote:
>> From: Johannes Thumshirn <johannes.thumshirn@wdc.com>
>>
>> Add bio_add_zone_append_page(), a wrapper around bio_add_hw_page() which
>> is intended to be used by file systems that directly add pages to a bio
>> instead of using bio_iov_iter_get_pages().
>
>Not sure what this is for, since I'm only on one patch in the series...

I'm sorry for the missing context. This patch is for this series.

https://lore.kernel.org/linux-btrfs/cover.1604065156.git.naohiro.aota@wdc.com/T/

This patch uses bio_add_zone_append_page in place of bio_add_page for zoned
device.

https://lore.kernel.org/linux-btrfs/cover.1604065156.git.naohiro.aota@wdc.com/T/#m88184d5dd11ac30c0878582898cd9d6f7cbc21fc

>
>> +/**
>> + * bio_add_zone_append_page - attempt to add page to zone-append bio
>> + * @bio: destination bio
>> + * @page: page to add
>> + * @len: vec entry length
>> + * @offset: vec entry offset
>> + *
>> + * Attempt to add a page to the bio_vec maplist of a bio that will be submitted
>> + * for a zone-append request. This can fail for a number of reasons, such as the
>> + * bio being full or the target block device is not a zoned block device or
>> + * other limitations of the target block device. The target block device must
>> + * allow bio's up to PAGE_SIZE, so it is always possible to add a single page
>> + * to an empty bio.
>> + */
>
>This should include a
>
>Return value:
>
>section, explaining how it returns number of bytes added (and why 0 is thus
>a failure case).
>
>> +int bio_add_zone_append_page(struct bio *bio, struct page *page,
>> +			     unsigned int len, unsigned int offset)
>
>Should this return unsigned int? If not, how would it work if someone
>asked for INT_MAX + 4k.
>
>-- 
>Jens Axboe
>

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 02/41] iomap: support REQ_OP_ZONE_APPEND
  2020-10-30 13:51   ` [PATCH v9 02/41] iomap: support REQ_OP_ZONE_APPEND Naohiro Aota
@ 2020-11-02  5:34     ` Naohiro Aota
  2020-11-02 16:55     ` Darrick J. Wong
  1 sibling, 0 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-11-02  5:34 UTC (permalink / raw)
  To: linux-btrfs, dsterba
  Cc: hare, linux-fsdevel, Christoph Hellwig, Darrick J. Wong, linux-xfs

Note: this patch is for this series.

https://lore.kernel.org/linux-btrfs/cover.1604065156.git.naohiro.aota@wdc.com/T/

The patch below uses IOMAP_F_ZONE_APPEND flag to make the iomap bio to be
REQ_OP_ZONE_APPEND.

https://lore.kernel.org/linux-btrfs/cover.1604065156.git.naohiro.aota@wdc.com/T/#m7b3f2d01ab554ea4cba244608655268211928799

On Fri, Oct 30, 2020 at 10:51:09PM +0900, Naohiro Aota wrote:
>A ZONE_APPEND bio must follow hardware restrictions (e.g. not exceeding
>max_zone_append_sectors) not to be split. bio_iov_iter_get_pages builds
>such restricted bio using __bio_iov_append_get_pages if bio_op(bio) ==
>REQ_OP_ZONE_APPEND.
>
>To utilize it, we need to set the bio_op before calling
>bio_iov_iter_get_pages(). This commit introduces IOMAP_F_ZONE_APPEND, so
>that iomap user can set the flag to indicate they want REQ_OP_ZONE_APPEND
>and restricted bio.
>
>Cc: Christoph Hellwig <hch@infradead.org>
>Cc: "Darrick J. Wong" <darrick.wong@oracle.com>
>Cc: linux-xfs@vger.kernel.org
>Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
>---
> fs/iomap/direct-io.c  | 22 ++++++++++++++++------
> include/linux/iomap.h |  1 +
> 2 files changed, 17 insertions(+), 6 deletions(-)
>
>diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
>index c1aafb2ab990..e534703c5594 100644
>--- a/fs/iomap/direct-io.c
>+++ b/fs/iomap/direct-io.c
>@@ -210,6 +210,7 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,
> 	struct bio *bio;
> 	bool need_zeroout = false;
> 	bool use_fua = false;
>+	bool zone_append = false;
> 	int nr_pages, ret = 0;
> 	size_t copied = 0;
> 	size_t orig_count;
>@@ -241,6 +242,8 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,
> 			use_fua = true;
> 	}
>
>+	zone_append = iomap->flags & IOMAP_F_ZONE_APPEND;
>+
> 	/*
> 	 * Save the original count and trim the iter to just the extent we
> 	 * are operating on right now.  The iter will be re-expanded once
>@@ -278,6 +281,19 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,
> 		bio->bi_private = dio;
> 		bio->bi_end_io = iomap_dio_bio_end_io;
>
>+		if (dio->flags & IOMAP_DIO_WRITE) {
>+			bio->bi_opf = (zone_append ? REQ_OP_ZONE_APPEND : REQ_OP_WRITE) |
>+				      REQ_SYNC | REQ_IDLE;
>+			if (use_fua)
>+				bio->bi_opf |= REQ_FUA;
>+			else
>+				dio->flags &= ~IOMAP_DIO_WRITE_FUA;
>+		} else {
>+			WARN_ON_ONCE(zone_append);
>+
>+			bio->bi_opf = REQ_OP_READ;
>+		}
>+
> 		ret = bio_iov_iter_get_pages(bio, dio->submit.iter);
> 		if (unlikely(ret)) {
> 			/*
>@@ -292,14 +308,8 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,
>
> 		n = bio->bi_iter.bi_size;
> 		if (dio->flags & IOMAP_DIO_WRITE) {
>-			bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_IDLE;
>-			if (use_fua)
>-				bio->bi_opf |= REQ_FUA;
>-			else
>-				dio->flags &= ~IOMAP_DIO_WRITE_FUA;
> 			task_io_account_write(n);
> 		} else {
>-			bio->bi_opf = REQ_OP_READ;
> 			if (dio->flags & IOMAP_DIO_DIRTY)
> 				bio_set_pages_dirty(bio);
> 		}
>diff --git a/include/linux/iomap.h b/include/linux/iomap.h
>index 4d1d3c3469e9..1bccd1880d0d 100644
>--- a/include/linux/iomap.h
>+++ b/include/linux/iomap.h
>@@ -54,6 +54,7 @@ struct vm_fault;
> #define IOMAP_F_SHARED		0x04
> #define IOMAP_F_MERGED		0x08
> #define IOMAP_F_BUFFER_HEAD	0x10
>+#define IOMAP_F_ZONE_APPEND	0x20
>
> /*
>  * Flags set by the core iomap code during operations:
>-- 
>2.27.0
>

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 01/41] block: add bio_add_zone_append_page
  2020-10-31  3:40   ` [PATCH v9 01/41] block: add bio_add_zone_append_page Jens Axboe
  2020-11-02  5:15     ` Naohiro Aota
@ 2020-11-02  8:24     ` Johannes Thumshirn
  1 sibling, 0 replies; 119+ messages in thread
From: Johannes Thumshirn @ 2020-11-02  8:24 UTC (permalink / raw)
  To: Jens Axboe, Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 31/10/2020 04:40, Jens Axboe wrote:
> On 10/30/20 7:51 AM, Naohiro Aota wrote:
>> From: Johannes Thumshirn <johannes.thumshirn@wdc.com>
>>
>> Add bio_add_zone_append_page(), a wrapper around bio_add_hw_page() which
>> is intended to be used by file systems that directly add pages to a bio
>> instead of using bio_iov_iter_get_pages().
> 
> Not sure what this is for, since I'm only on one patch in the series...

Sorry, we'll Cc you on the whole series.

> 
>> +/**
>> + * bio_add_zone_append_page - attempt to add page to zone-append bio
>> + * @bio: destination bio
>> + * @page: page to add
>> + * @len: vec entry length
>> + * @offset: vec entry offset
>> + *
>> + * Attempt to add a page to the bio_vec maplist of a bio that will be submitted
>> + * for a zone-append request. This can fail for a number of reasons, such as the
>> + * bio being full or the target block device is not a zoned block device or
>> + * other limitations of the target block device. The target block device must
>> + * allow bio's up to PAGE_SIZE, so it is always possible to add a single page
>> + * to an empty bio.
>> + */
> 
> This should include a
> 
> Return value:
> 
> section, explaining how it returns number of bytes added (and why 0 is thus
> a failure case).


I'll update the comment to include the return value. It was just a copy and paste
of bio_add_page() and it didn't have the return value documented, so this is why
I missed it here.

I'll probably should document the existing functions as well.

>> +int bio_add_zone_append_page(struct bio *bio, struct page *page,
>> +			     unsigned int len, unsigned int offset)
> 
> Should this return unsigned int? If not, how would it work if someone
> asked for INT_MAX + 4k.
> 

I don't think this is needed as we can't go over 2G anyways, can't we? bio_add_page() 
also returns an int and I wanted to have a consistent interface here.


^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 04/41] btrfs: Get zone information of zoned block devices
  2020-10-30 13:51   ` [PATCH v9 04/41] btrfs: Get zone information of zoned block devices Naohiro Aota
@ 2020-11-02 16:53     ` Josef Bacik
  2020-11-02 16:58       ` Johannes Thumshirn
  2020-11-02 21:07       ` Naohiro Aota
  2020-11-03 12:02     ` David Sterba
  1 sibling, 2 replies; 119+ messages in thread
From: Josef Bacik @ 2020-11-02 16:53 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel, Damien Le Moal

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> If a zoned block device is found, get its zone information (number of zones
> and zone size) using the new helper function btrfs_get_dev_zone_info().  To
> avoid costly run-time zone report commands to test the device zones type
> during block allocation, attach the seq_zones bitmap to the device
> structure to indicate if a zone is sequential or accept random writes. Also
> it attaches the empty_zones bitmap to indicate if a zone is empty or not.
> 
> This patch also introduces the helper function btrfs_dev_is_sequential() to
> test if the zone storing a block is a sequential write required zone and
> btrfs_dev_is_empty_zone() to test if the zone is a empty zone.
> 
> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> Reviewed-by: Josef Bacik <josef@toxicpanda.com>
> ---
>   fs/btrfs/Makefile      |   1 +
>   fs/btrfs/dev-replace.c |   5 ++
>   fs/btrfs/super.c       |   5 ++
>   fs/btrfs/volumes.c     |  19 ++++-
>   fs/btrfs/volumes.h     |   4 +
>   fs/btrfs/zoned.c       | 176 +++++++++++++++++++++++++++++++++++++++++
>   fs/btrfs/zoned.h       |  86 ++++++++++++++++++++
>   7 files changed, 294 insertions(+), 2 deletions(-)
>   create mode 100644 fs/btrfs/zoned.c
>   create mode 100644 fs/btrfs/zoned.h
> 
> diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
> index e738f6206ea5..0497fdc37f90 100644
> --- a/fs/btrfs/Makefile
> +++ b/fs/btrfs/Makefile
> @@ -16,6 +16,7 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
>   btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o
>   btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o
>   btrfs-$(CONFIG_BTRFS_FS_REF_VERIFY) += ref-verify.o
> +btrfs-$(CONFIG_BLK_DEV_ZONED) += zoned.o
>   
>   btrfs-$(CONFIG_BTRFS_FS_RUN_SANITY_TESTS) += tests/free-space-tests.o \
>   	tests/extent-buffer-tests.o tests/btrfs-tests.o \
> diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
> index 20ce1970015f..6f6d77224c2b 100644
> --- a/fs/btrfs/dev-replace.c
> +++ b/fs/btrfs/dev-replace.c
> @@ -21,6 +21,7 @@
>   #include "rcu-string.h"
>   #include "dev-replace.h"
>   #include "sysfs.h"
> +#include "zoned.h"
>   
>   /*
>    * Device replace overview
> @@ -291,6 +292,10 @@ static int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
>   	set_blocksize(device->bdev, BTRFS_BDEV_BLOCKSIZE);
>   	device->fs_devices = fs_info->fs_devices;
>   
> +	ret = btrfs_get_dev_zone_info(device);
> +	if (ret)
> +		goto error;
> +
>   	mutex_lock(&fs_info->fs_devices->device_list_mutex);
>   	list_add(&device->dev_list, &fs_info->fs_devices->devices);
>   	fs_info->fs_devices->num_devices++;
> diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
> index 8840a4fa81eb..ed55014fd1bd 100644
> --- a/fs/btrfs/super.c
> +++ b/fs/btrfs/super.c
> @@ -2462,6 +2462,11 @@ static void __init btrfs_print_mod_info(void)
>   #endif
>   #ifdef CONFIG_BTRFS_FS_REF_VERIFY
>   			", ref-verify=on"
> +#endif
> +#ifdef CONFIG_BLK_DEV_ZONED
> +			", zoned=yes"
> +#else
> +			", zoned=no"
>   #endif
>   			;
>   	pr_info("Btrfs loaded, crc32c=%s%s\n", crc32c_impl(), options);
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index 58b9c419a2b6..e787bf89f761 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -31,6 +31,7 @@
>   #include "space-info.h"
>   #include "block-group.h"
>   #include "discard.h"
> +#include "zoned.h"
>   
>   const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
>   	[BTRFS_RAID_RAID10] = {
> @@ -374,6 +375,7 @@ void btrfs_free_device(struct btrfs_device *device)
>   	rcu_string_free(device->name);
>   	extent_io_tree_release(&device->alloc_state);
>   	bio_put(device->flush_bio);
> +	btrfs_destroy_dev_zone_info(device);
>   	kfree(device);
>   }
>   
> @@ -667,6 +669,11 @@ static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices,
>   	clear_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
>   	device->mode = flags;
>   
> +	/* Get zone type information of zoned block devices */
> +	ret = btrfs_get_dev_zone_info(device);
> +	if (ret != 0)
> +		goto error_free_page;
> +
>   	fs_devices->open_devices++;
>   	if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) &&
>   	    device->devid != BTRFS_DEV_REPLACE_DEVID) {
> @@ -1143,6 +1150,7 @@ static void btrfs_close_one_device(struct btrfs_device *device)
>   		device->bdev = NULL;
>   	}
>   	clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
> +	btrfs_destroy_dev_zone_info(device);
>   
>   	device->fs_info = NULL;
>   	atomic_set(&device->dev_stats_ccnt, 0);
> @@ -2543,6 +2551,14 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
>   	}
>   	rcu_assign_pointer(device->name, name);
>   
> +	device->fs_info = fs_info;
> +	device->bdev = bdev;
> +
> +	/* Get zone type information of zoned block devices */
> +	ret = btrfs_get_dev_zone_info(device);
> +	if (ret)
> +		goto error_free_device;
> +
>   	trans = btrfs_start_transaction(root, 0);
>   	if (IS_ERR(trans)) {
>   		ret = PTR_ERR(trans);
> @@ -2559,8 +2575,6 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
>   					 fs_info->sectorsize);
>   	device->disk_total_bytes = device->total_bytes;
>   	device->commit_total_bytes = device->total_bytes;
> -	device->fs_info = fs_info;
> -	device->bdev = bdev;
>   	set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
>   	clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
>   	device->mode = FMODE_EXCL;
> @@ -2707,6 +2721,7 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
>   		sb->s_flags |= SB_RDONLY;
>   	if (trans)
>   		btrfs_end_transaction(trans);
> +	btrfs_destroy_dev_zone_info(device);
>   error_free_device:
>   	btrfs_free_device(device);
>   error:
> diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
> index bf27ac07d315..9c07b97a2260 100644
> --- a/fs/btrfs/volumes.h
> +++ b/fs/btrfs/volumes.h
> @@ -51,6 +51,8 @@ struct btrfs_io_geometry {
>   #define BTRFS_DEV_STATE_REPLACE_TGT	(3)
>   #define BTRFS_DEV_STATE_FLUSH_SENT	(4)
>   
> +struct btrfs_zoned_device_info;
> +
>   struct btrfs_device {
>   	struct list_head dev_list; /* device_list_mutex */
>   	struct list_head dev_alloc_list; /* chunk mutex */
> @@ -64,6 +66,8 @@ struct btrfs_device {
>   
>   	struct block_device *bdev;
>   
> +	struct btrfs_zoned_device_info *zone_info;
> +
>   	/* the mode sent to blkdev_get */
>   	fmode_t mode;
>   
> diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
> new file mode 100644
> index 000000000000..5657d654bc44
> --- /dev/null
> +++ b/fs/btrfs/zoned.c
> @@ -0,0 +1,176 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#include <linux/slab.h>
> +#include <linux/blkdev.h>
> +#include "ctree.h"
> +#include "volumes.h"
> +#include "zoned.h"
> +#include "rcu-string.h"
> +
> +/* Maximum number of zones to report per blkdev_report_zones() call */
> +#define BTRFS_REPORT_NR_ZONES   4096
> +
> +static int copy_zone_info_cb(struct blk_zone *zone, unsigned int idx,
> +			     void *data)
> +{
> +	struct blk_zone *zones = data;
> +
> +	memcpy(&zones[idx], zone, sizeof(*zone));
> +
> +	return 0;
> +}
> +
> +static int btrfs_get_dev_zones(struct btrfs_device *device, u64 pos,
> +			       struct blk_zone *zones, unsigned int *nr_zones)
> +{
> +	int ret;
> +
> +	if (!*nr_zones)
> +		return 0;
> +
> +	ret = blkdev_report_zones(device->bdev, pos >> SECTOR_SHIFT, *nr_zones,
> +				  copy_zone_info_cb, zones);
> +	if (ret < 0) {
> +		btrfs_err_in_rcu(device->fs_info,
> +				 "get zone at %llu on %s failed %d", pos,
> +				 rcu_str_deref(device->name), ret);
> +		return ret;
> +	}
> +	*nr_zones = ret;
> +	if (!ret)
> +		return -EIO;
> +
> +	return 0;
> +}
> +
> +int btrfs_get_dev_zone_info(struct btrfs_device *device)
> +{
> +	struct btrfs_zoned_device_info *zone_info = NULL;
> +	struct block_device *bdev = device->bdev;
> +	sector_t nr_sectors = bdev->bd_part->nr_sects;
> +	sector_t sector = 0;
> +	struct blk_zone *zones = NULL;
> +	unsigned int i, nreported = 0, nr_zones;
> +	unsigned int zone_sectors;
> +	int ret;
> +	char devstr[sizeof(device->fs_info->sb->s_id) +
> +		    sizeof(" (device )") - 1];
> +
> +	if (!bdev_is_zoned(bdev))
> +		return 0;
> +
> +	if (device->zone_info)
> +		return 0;
> +
> +	zone_info = kzalloc(sizeof(*zone_info), GFP_KERNEL);
> +	if (!zone_info)
> +		return -ENOMEM;
> +
> +	zone_sectors = bdev_zone_sectors(bdev);
> +	ASSERT(is_power_of_2(zone_sectors));
> +	zone_info->zone_size = (u64)zone_sectors << SECTOR_SHIFT;
> +	zone_info->zone_size_shift = ilog2(zone_info->zone_size);
> +	zone_info->nr_zones = nr_sectors >> ilog2(bdev_zone_sectors(bdev));
> +	if (!IS_ALIGNED(nr_sectors, zone_sectors))
> +		zone_info->nr_zones++;
> +
> +	zone_info->seq_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
> +	if (!zone_info->seq_zones) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +
> +	zone_info->empty_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
> +	if (!zone_info->empty_zones) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +
> +	zones = kcalloc(BTRFS_REPORT_NR_ZONES,
> +			sizeof(struct blk_zone), GFP_KERNEL);
> +	if (!zones) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +
> +	/* Get zones type */
> +	while (sector < nr_sectors) {
> +		nr_zones = BTRFS_REPORT_NR_ZONES;
> +		ret = btrfs_get_dev_zones(device, sector << SECTOR_SHIFT, zones,
> +					  &nr_zones);
> +		if (ret)
> +			goto out;
> +
> +		for (i = 0; i < nr_zones; i++) {
> +			if (zones[i].type == BLK_ZONE_TYPE_SEQWRITE_REQ)
> +				set_bit(nreported, zone_info->seq_zones);
> +			if (zones[i].cond == BLK_ZONE_COND_EMPTY)
> +				set_bit(nreported, zone_info->empty_zones);
> +			nreported++;
> +		}
> +		sector = zones[nr_zones - 1].start + zones[nr_zones - 1].len;
> +	}
> +
> +	if (nreported != zone_info->nr_zones) {
> +		btrfs_err_in_rcu(device->fs_info,
> +				 "inconsistent number of zones on %s (%u / %u)",
> +				 rcu_str_deref(device->name), nreported,
> +				 zone_info->nr_zones);
> +		ret = -EIO;
> +		goto out;
> +	}
> +
> +	kfree(zones);
> +
> +	device->zone_info = zone_info;
> +
> +	devstr[0] = 0;
> +	if (device->fs_info)
> +		snprintf(devstr, sizeof(devstr), " (device %s)",
> +			 device->fs_info->sb->s_id);
> +
> +	rcu_read_lock();
> +	pr_info(

Why isn't this btrfs_info() ?  Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 02/41] iomap: support REQ_OP_ZONE_APPEND
  2020-10-30 13:51   ` [PATCH v9 02/41] iomap: support REQ_OP_ZONE_APPEND Naohiro Aota
  2020-11-02  5:34     ` Naohiro Aota
@ 2020-11-02 16:55     ` Darrick J. Wong
  2020-11-02 17:39       ` Johannes Thumshirn
  1 sibling, 1 reply; 119+ messages in thread
From: Darrick J. Wong @ 2020-11-02 16:55 UTC (permalink / raw)
  To: Naohiro Aota
  Cc: linux-btrfs, dsterba, hare, linux-fsdevel, Christoph Hellwig, linux-xfs

On Fri, Oct 30, 2020 at 10:51:09PM +0900, Naohiro Aota wrote:
> A ZONE_APPEND bio must follow hardware restrictions (e.g. not exceeding
> max_zone_append_sectors) not to be split. bio_iov_iter_get_pages builds
> such restricted bio using __bio_iov_append_get_pages if bio_op(bio) ==
> REQ_OP_ZONE_APPEND.
> 
> To utilize it, we need to set the bio_op before calling
> bio_iov_iter_get_pages(). This commit introduces IOMAP_F_ZONE_APPEND, so
> that iomap user can set the flag to indicate they want REQ_OP_ZONE_APPEND
> and restricted bio.

Would you mind putting this paragraph in a comment before the
bio_iov_iter_get_pages call?  I could easily see someone (i.e. 2021 me)
forgetting there's a data dependency and breaking this.

> Cc: Christoph Hellwig <hch@infradead.org>
> Cc: "Darrick J. Wong" <darrick.wong@oracle.com>
> Cc: linux-xfs@vger.kernel.org
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> ---
>  fs/iomap/direct-io.c  | 22 ++++++++++++++++------
>  include/linux/iomap.h |  1 +
>  2 files changed, 17 insertions(+), 6 deletions(-)
> 
> diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> index c1aafb2ab990..e534703c5594 100644
> --- a/fs/iomap/direct-io.c
> +++ b/fs/iomap/direct-io.c
> @@ -210,6 +210,7 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,
>  	struct bio *bio;
>  	bool need_zeroout = false;
>  	bool use_fua = false;
> +	bool zone_append = false;
>  	int nr_pages, ret = 0;
>  	size_t copied = 0;
>  	size_t orig_count;
> @@ -241,6 +242,8 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,
>  			use_fua = true;
>  	}
>  
> +	zone_append = ;
> +
>  	/*
>  	 * Save the original count and trim the iter to just the extent we
>  	 * are operating on right now.  The iter will be re-expanded once
> @@ -278,6 +281,19 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,
>  		bio->bi_private = dio;
>  		bio->bi_end_io = iomap_dio_bio_end_io;
>  
> +		if (dio->flags & IOMAP_DIO_WRITE) {
> +			bio->bi_opf = (zone_append ? REQ_OP_ZONE_APPEND : REQ_OP_WRITE) |
> +				      REQ_SYNC | REQ_IDLE;
> +			if (use_fua)
> +				bio->bi_opf |= REQ_FUA;
> +			else
> +				dio->flags &= ~IOMAP_DIO_WRITE_FUA;
> +		} else {
> +			WARN_ON_ONCE(zone_append);
> +
> +			bio->bi_opf = REQ_OP_READ;
> +		}

Also, I think this should be hoisted into a separate helper to return
bi_opf rather than making iomap_dio_bio_actor even longer...

/*
 * Figure out the bio's operation flags from the dio request, the
 * mapping, and whether or not we want FUA.  Note that we can end up
 * clearing the WRITE_FUA flag in the dio request.
 */
static inline unsigned int
iomap_dio_bio_opflags(struct iomap_dio *dio, struct iomap *iomap, bool use_fua)
{
	unsigned int opflags = REQ_SYNC | REQ_IDLE;

	if (!(dio->flags & IOMAP_DIO_WRITE)) {
		WARN_ON_ONCE(iomap->flags & IOMAP_F_ZONE_APPEND);
		return REQ_OP_READ;
	}

	if (iomap->flags & IOMAP_F_ZONE_APPEND)
		opflags |= REQ_OP_ZONE_APPEND;
	else
		opflags |= REQ_OP_WRITE;

	if (use_fua)
		opflags |= REQ_FUA;
	else
		dio->flags &= ~IOMAP_DIO_WRITE_FUA;

	return opflags;
}

	/*
	 * Set the operation flags early so that bio_iov_iter_get_pages can
	 * set up the page vector appropriately for a ZONE_APPEND operation.
	 */
	bio->bi_opf = iomap_dio_bio_opflags(dio, iomap, use_fua);

	ret = bio_iov_iter_get_pages(bio, dio->submit.iter);
	if (unlikely(ret)) {

--D

> +
>  		ret = bio_iov_iter_get_pages(bio, dio->submit.iter);
>  		if (unlikely(ret)) {
>  			/*
> @@ -292,14 +308,8 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,
>  
>  		n = bio->bi_iter.bi_size;
>  		if (dio->flags & IOMAP_DIO_WRITE) {
> -			bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_IDLE;
> -			if (use_fua)
> -				bio->bi_opf |= REQ_FUA;
> -			else
> -				dio->flags &= ~IOMAP_DIO_WRITE_FUA;
>  			task_io_account_write(n);
>  		} else {
> -			bio->bi_opf = REQ_OP_READ;
>  			if (dio->flags & IOMAP_DIO_DIRTY)
>  				bio_set_pages_dirty(bio);
>  		}
> diff --git a/include/linux/iomap.h b/include/linux/iomap.h
> index 4d1d3c3469e9..1bccd1880d0d 100644
> --- a/include/linux/iomap.h
> +++ b/include/linux/iomap.h
> @@ -54,6 +54,7 @@ struct vm_fault;
>  #define IOMAP_F_SHARED		0x04
>  #define IOMAP_F_MERGED		0x08
>  #define IOMAP_F_BUFFER_HEAD	0x10
> +#define IOMAP_F_ZONE_APPEND	0x20
>  
>  /*
>   * Flags set by the core iomap code during operations:
> -- 
> 2.27.0
> 

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 06/41] btrfs: introduce max_zone_append_size
  2020-10-30 13:51   ` [PATCH v9 06/41] btrfs: introduce max_zone_append_size Naohiro Aota
@ 2020-11-02 16:57     ` Josef Bacik
  2020-11-03 12:16     ` David Sterba
  1 sibling, 0 replies; 119+ messages in thread
From: Josef Bacik @ 2020-11-02 16:57 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> The zone append write command has a maximum IO size restriction it
> accepts. This is because a zone append write command cannot be split, as
> we ask the device to place the data into a specific target zone and the
> device responds with the actual written location of the data.
> 
> Introduce max_zone_append_size to zone_info and fs_info to track the
> value, so we can limit all I/O to a zoned block device that we want to
> write using the zone append command to the device's limits.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 04/41] btrfs: Get zone information of zoned block devices
  2020-11-02 16:53     ` Josef Bacik
@ 2020-11-02 16:58       ` Johannes Thumshirn
  2020-11-02 21:07       ` Naohiro Aota
  1 sibling, 0 replies; 119+ messages in thread
From: Johannes Thumshirn @ 2020-11-02 16:58 UTC (permalink / raw)
  To: Josef Bacik, Naohiro Aota, linux-btrfs, dsterba
  Cc: hare, linux-fsdevel, Damien Le Moal

On 02/11/2020 17:53, Josef Bacik wrote:
> Why isn't this btrfs_info() ?

Plain oversight...

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 07/41] btrfs: disallow space_cache in ZONED mode
  2020-10-30 13:51   ` [PATCH v9 07/41] btrfs: disallow space_cache in ZONED mode Naohiro Aota
@ 2020-11-02 17:02     ` Josef Bacik
  2020-11-02 17:37       ` Johannes Thumshirn
  2020-11-03 12:48     ` David Sterba
  1 sibling, 1 reply; 119+ messages in thread
From: Josef Bacik @ 2020-11-02 17:02 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> As updates to the space cache v1 are in-place, the space cache cannot be
> located over sequential zones and there is no guarantees that the device
> will have enough conventional zones to store this cache. Resolve this
> problem by disabling completely the space cache v1.  This does not
> introduces any problems with sequential block groups: all the free space is
> located after the allocation pointer and no free space before the pointer.
> There is no need to have such cache.
> 
> Note: we can technically use free-space-tree (space cache v2) on ZONED
> mode. But, since ZONED mode now always allocate extents in a block group
> sequentially regardless of underlying device zone type, it's no use to
> enable and maintain the tree.
> 
> For the same reason, NODATACOW is also disabled.
> 
> Also INODE_MAP_CACHE is also disabled to avoid preallocation in the
> INODE_MAP_CACHE inode.
> 
> In summary, ZONED will disable:
> 
> | Disabled features | Reason                                              |
> |-------------------+-----------------------------------------------------|
> | RAID/Dup          | Cannot handle two zone append writes to different   |
> |                   | zones                                               |
> |-------------------+-----------------------------------------------------|
> | space_cache (v1)  | In-place updating                                   |
> | NODATACOW         | In-place updating                                   |
> |-------------------+-----------------------------------------------------|
> | fallocate         | Reserved extent will be a write hole                |
> | INODE_MAP_CACHE   | Need pre-allocation. (and will be deprecated?)      |
> |-------------------+-----------------------------------------------------|
> | MIXED_BG          | Allocated metadata region will be write holes for   |
> |                   | data writes                                         |
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> ---
>   fs/btrfs/super.c | 12 ++++++++++--
>   fs/btrfs/zoned.c | 18 ++++++++++++++++++
>   fs/btrfs/zoned.h |  5 +++++
>   3 files changed, 33 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
> index 3312fe08168f..9064ca62b0a0 100644
> --- a/fs/btrfs/super.c
> +++ b/fs/btrfs/super.c
> @@ -525,8 +525,14 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
>   	cache_gen = btrfs_super_cache_generation(info->super_copy);
>   	if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE))
>   		btrfs_set_opt(info->mount_opt, FREE_SPACE_TREE);
> -	else if (cache_gen)
> -		btrfs_set_opt(info->mount_opt, SPACE_CACHE);
> +	else if (cache_gen) {
> +		if (btrfs_is_zoned(info)) {
> +			btrfs_info(info,
> +			"clearring existing space cache in ZONED mode");

'clearing', and then you can add

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 08/41] btrfs: disallow NODATACOW in ZONED mode
  2020-10-30 13:51   ` [PATCH v9 08/41] btrfs: disallow NODATACOW " Naohiro Aota
@ 2020-11-02 17:05     ` Josef Bacik
  2020-11-03 12:57     ` David Sterba
  1 sibling, 0 replies; 119+ messages in thread
From: Josef Bacik @ 2020-11-02 17:05 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba
  Cc: hare, linux-fsdevel, Johannes Thumshirn

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> NODATACOW implies overwriting the file data on a device, which is
> impossible in sequential required zones. Disable NODATACOW globally with
> mount option and per-file NODATACOW attribute by masking FS_NOCOW_FL.
> 
> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 07/41] btrfs: disallow space_cache in ZONED mode
  2020-11-02 17:02     ` Josef Bacik
@ 2020-11-02 17:37       ` Johannes Thumshirn
  0 siblings, 0 replies; 119+ messages in thread
From: Johannes Thumshirn @ 2020-11-02 17:37 UTC (permalink / raw)
  To: Josef Bacik, Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 02/11/2020 18:02, Josef Bacik wrote:
> 'clearing', and then you can add

Fixed up, thanks

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 02/41] iomap: support REQ_OP_ZONE_APPEND
  2020-11-02 16:55     ` Darrick J. Wong
@ 2020-11-02 17:39       ` Johannes Thumshirn
  0 siblings, 0 replies; 119+ messages in thread
From: Johannes Thumshirn @ 2020-11-02 17:39 UTC (permalink / raw)
  To: Darrick J. Wong, Naohiro Aota
  Cc: linux-btrfs, dsterba, hare, linux-fsdevel, hch, linux-xfs

On 02/11/2020 17:55, Darrick J. Wong wrote:
> Also, I think this should be hoisted into a separate helper to return
> bi_opf rather than making iomap_dio_bio_actor even longer...


Fixed up, thanks.

(Speaking for Naohiro here)

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 11/41] btrfs: implement log-structured superblock for ZONED mode
  2020-10-30 13:51   ` [PATCH v9 11/41] btrfs: implement log-structured superblock for " Naohiro Aota
@ 2020-11-02 18:22     ` Josef Bacik
  2020-11-02 18:53       ` Johannes Thumshirn
  2020-11-03  8:21       ` Naohiro Aota
  2020-11-02 18:54     ` Josef Bacik
                       ` (2 subsequent siblings)
  3 siblings, 2 replies; 119+ messages in thread
From: Josef Bacik @ 2020-11-02 18:22 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> Superblock (and its copies) is the only data structure in btrfs which has a
> fixed location on a device. Since we cannot overwrite in a sequential write
> required zone, we cannot place superblock in the zone. One easy solution is
> limiting superblock and copies to be placed only in conventional zones.
> However, this method has two downsides: one is reduced number of superblock
> copies. The location of the second copy of superblock is 256GB, which is in
> a sequential write required zone on typical devices in the market today.
> So, the number of superblock and copies is limited to be two.  Second
> downside is that we cannot support devices which have no conventional zones
> at all.
> 
> To solve these two problems, we employ superblock log writing. It uses two
> zones as a circular buffer to write updated superblocks. Once the first
> zone is filled up, start writing into the second buffer. Then, when the
> both zones are filled up and before start writing to the first zone again,
> it reset the first zone.
> 
> We can determine the position of the latest superblock by reading write
> pointer information from a device. One corner case is when the both zones
> are full. For this situation, we read out the last superblock of each
> zone, and compare them to determine which zone is older.
> 
> The following zones are reserved as the circular buffer on ZONED btrfs.
> 
> - The primary superblock: zones 0 and 1
> - The first copy: zones 16 and 17
> - The second copy: zones 1024 or zone at 256GB which is minimum, and next
>    to it
> 
> If these reserved zones are conventional, superblock is written fixed at
> the start of the zone without logging.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> ---
>   fs/btrfs/block-group.c |   9 ++
>   fs/btrfs/disk-io.c     |  41 +++++-
>   fs/btrfs/scrub.c       |   3 +
>   fs/btrfs/volumes.c     |  21 ++-
>   fs/btrfs/zoned.c       | 311 +++++++++++++++++++++++++++++++++++++++++
>   fs/btrfs/zoned.h       |  40 ++++++
>   6 files changed, 413 insertions(+), 12 deletions(-)
> 
> diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
> index c0f1d6818df7..e989c66aa764 100644
> --- a/fs/btrfs/block-group.c
> +++ b/fs/btrfs/block-group.c
> @@ -1723,6 +1723,7 @@ int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
>   static int exclude_super_stripes(struct btrfs_block_group *cache)
>   {
>   	struct btrfs_fs_info *fs_info = cache->fs_info;
> +	bool zoned = btrfs_is_zoned(fs_info);
>   	u64 bytenr;
>   	u64 *logical;
>   	int stripe_len;
> @@ -1744,6 +1745,14 @@ static int exclude_super_stripes(struct btrfs_block_group *cache)
>   		if (ret)
>   			return ret;
>   
> +		/* shouldn't have super stripes in sequential zones */
> +		if (zoned && nr) {
> +			btrfs_err(fs_info,
> +				  "Zoned btrfs's block group %llu should not have super blocks",
> +				  cache->start);
> +			return -EUCLEAN;
> +		}
> +

I'm very confused about this check, namely how you've been able to test without 
it blowing up, which makes me feel like I'm missing something.

We _always_ call exclude_super_stripes(), and we're simply looking up the bytenr 
for that block, which appears to not do anything special for zoned.  This should 
be looking up and failing whenever it looks for super stripes far enough out. 
How are you not failing here everytime you mount the fs?  Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 11/41] btrfs: implement log-structured superblock for ZONED mode
  2020-11-02 18:22     ` Josef Bacik
@ 2020-11-02 18:53       ` Johannes Thumshirn
  2020-11-02 19:01         ` Josef Bacik
  2020-11-03  8:21       ` Naohiro Aota
  1 sibling, 1 reply; 119+ messages in thread
From: Johannes Thumshirn @ 2020-11-02 18:53 UTC (permalink / raw)
  To: Josef Bacik, Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 02/11/2020 19:23, Josef Bacik wrote:
>> +		/* shouldn't have super stripes in sequential zones */
>> +		if (zoned && nr) {
>> +			btrfs_err(fs_info,
>> +				  "Zoned btrfs's block group %llu should not have super blocks",
>> +				  cache->start);
>> +			return -EUCLEAN;
>> +		}
>> +
> I'm very confused about this check, namely how you've been able to test without 
> it blowing up, which makes me feel like I'm missing something.
> 
> We _always_ call exclude_super_stripes(), and we're simply looking up the bytenr 
> for that block, which appears to not do anything special for zoned.  This should 
> be looking up and failing whenever it looks for super stripes far enough out. 
> How are you not failing here everytime you mount the fs?  Thanks,

Naohiro (or Josef and everyone else as well of cause), please correct me if I'm 
wrong, but on zoned btrfs we're not supporting any RAID type. So the call to 
btrfs_rmap_block() above will return 'nr = 0' (as we're always having 
map->num_stripes = 1) so this won't evaluate to true.

Byte,
	Johannes

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 11/41] btrfs: implement log-structured superblock for ZONED mode
  2020-10-30 13:51   ` [PATCH v9 11/41] btrfs: implement log-structured superblock for " Naohiro Aota
  2020-11-02 18:22     ` Josef Bacik
@ 2020-11-02 18:54     ` Josef Bacik
  2020-11-03  3:31       ` Naohiro Aota
  2020-11-03 13:15     ` David Sterba
  2020-11-03 14:10     ` David Sterba
  3 siblings, 1 reply; 119+ messages in thread
From: Josef Bacik @ 2020-11-02 18:54 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> Superblock (and its copies) is the only data structure in btrfs which has a
> fixed location on a device. Since we cannot overwrite in a sequential write
> required zone, we cannot place superblock in the zone. One easy solution is
> limiting superblock and copies to be placed only in conventional zones.
> However, this method has two downsides: one is reduced number of superblock
> copies. The location of the second copy of superblock is 256GB, which is in
> a sequential write required zone on typical devices in the market today.
> So, the number of superblock and copies is limited to be two.  Second
> downside is that we cannot support devices which have no conventional zones
> at all.
> 
> To solve these two problems, we employ superblock log writing. It uses two
> zones as a circular buffer to write updated superblocks. Once the first
> zone is filled up, start writing into the second buffer. Then, when the
> both zones are filled up and before start writing to the first zone again,
> it reset the first zone.
> 
> We can determine the position of the latest superblock by reading write
> pointer information from a device. One corner case is when the both zones
> are full. For this situation, we read out the last superblock of each
> zone, and compare them to determine which zone is older.
> 
> The following zones are reserved as the circular buffer on ZONED btrfs.
> 
> - The primary superblock: zones 0 and 1
> - The first copy: zones 16 and 17
> - The second copy: zones 1024 or zone at 256GB which is minimum, and next
>    to it
> 
> If these reserved zones are conventional, superblock is written fixed at
> the start of the zone without logging.
> 

<snip>

>   
>   /*
>    * This is only the first step towards a full-features scrub. It reads all
> @@ -3704,6 +3705,8 @@ static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
>   		if (bytenr + BTRFS_SUPER_INFO_SIZE >
>   		    scrub_dev->commit_total_bytes)
>   			break;
> +		if (!btrfs_check_super_location(scrub_dev, bytenr))
> +			continue;

Any reason in particular we're skipping scrubbing supers here?  Can't we just 
lookup the bytenr and do the right thing here?

>   
>   		ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
>   				  scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index 10827892c086..db884b96a5ea 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -1282,7 +1282,8 @@ void btrfs_release_disk_super(struct btrfs_super_block *super)
>   }
>   
>   static struct btrfs_super_block *btrfs_read_disk_super(struct block_device *bdev,
> -						       u64 bytenr)
> +						       u64 bytenr,
> +						       u64 bytenr_orig)
>   {
>   	struct btrfs_super_block *disk_super;
>   	struct page *page;
> @@ -1313,7 +1314,7 @@ static struct btrfs_super_block *btrfs_read_disk_super(struct block_device *bdev
>   	/* align our pointer to the offset of the super block */
>   	disk_super = p + offset_in_page(bytenr);
>   
> -	if (btrfs_super_bytenr(disk_super) != bytenr ||
> +	if (btrfs_super_bytenr(disk_super) != bytenr_orig ||
>   	    btrfs_super_magic(disk_super) != BTRFS_MAGIC) {
>   		btrfs_release_disk_super(p);
>   		return ERR_PTR(-EINVAL);
> @@ -1348,7 +1349,8 @@ struct btrfs_device *btrfs_scan_one_device(const char *path, fmode_t flags,
>   	bool new_device_added = false;
>   	struct btrfs_device *device = NULL;
>   	struct block_device *bdev;
> -	u64 bytenr;
> +	u64 bytenr, bytenr_orig;
> +	int ret;
>   
>   	lockdep_assert_held(&uuid_mutex);
>   
> @@ -1358,14 +1360,18 @@ struct btrfs_device *btrfs_scan_one_device(const char *path, fmode_t flags,
>   	 * So, we need to add a special mount option to scan for
>   	 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
>   	 */
> -	bytenr = btrfs_sb_offset(0);
>   	flags |= FMODE_EXCL;
>   
>   	bdev = blkdev_get_by_path(path, flags, holder);
>   	if (IS_ERR(bdev))
>   		return ERR_CAST(bdev);
>   
> -	disk_super = btrfs_read_disk_super(bdev, bytenr);
> +	bytenr_orig = btrfs_sb_offset(0);
> +	ret = btrfs_sb_log_location_bdev(bdev, 0, READ, &bytenr);
> +	if (ret)
> +		return ERR_PTR(ret);
> +
> +	disk_super = btrfs_read_disk_super(bdev, bytenr, bytenr_orig);
>   	if (IS_ERR(disk_super)) {
>   		device = ERR_CAST(disk_super);
>   		goto error_bdev_put;
> @@ -2029,6 +2035,11 @@ void btrfs_scratch_superblocks(struct btrfs_fs_info *fs_info,
>   		if (IS_ERR(disk_super))
>   			continue;
>   
> +		if (bdev_is_zoned(bdev)) {
> +			btrfs_reset_sb_log_zones(bdev, copy_num);
> +			continue;
> +		}
> +
>   		memset(&disk_super->magic, 0, sizeof(disk_super->magic));
>   
>   		page = virt_to_page(disk_super);
> diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
> index ae509699da14..d5487cba203b 100644
> --- a/fs/btrfs/zoned.c
> +++ b/fs/btrfs/zoned.c
> @@ -20,6 +20,25 @@ static int copy_zone_info_cb(struct blk_zone *zone, unsigned int idx,
>   	return 0;
>   }
>   
> +static int sb_write_pointer(struct block_device *bdev, struct blk_zone *zone,
> +			    u64 *wp_ret);
> +
> +static inline u32 sb_zone_number(u8 shift, int mirror)
> +{
> +	ASSERT(mirror < BTRFS_SUPER_MIRROR_MAX);
> +
> +	switch (mirror) {
> +	case 0:
> +		return 0;
> +	case 1:
> +		return 16;
> +	case 2:
> +		return min(btrfs_sb_offset(mirror) >> shift, 1024ULL);
> +	}
> +

Can we get a comment here explaining the zone numbers?

> +	return 0;
> +}
> +
>   static int btrfs_get_dev_zones(struct btrfs_device *device, u64 pos,
>   			       struct blk_zone *zones, unsigned int *nr_zones)
>   {
> @@ -123,6 +142,49 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device)
>   		goto out;
>   	}
>   
> +	/* validate superblock log */
> +	nr_zones = 2;
> +	for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
> +		u32 sb_zone = sb_zone_number(zone_info->zone_size_shift, i);
> +		u64 sb_wp;
> +

I'd rather see

#define BTRFS_NR_ZONED_SB_ZONES 2

or something equally poorly named and use that instead of our magic 2 everywhere.

Then you can just do

int index = i * BTRFS_NR_ZONED_SB_ZONES;
&zone_info->sb_zones[index];

<snip>

> +static int sb_log_location(struct block_device *bdev, struct blk_zone *zones,
> +			   int rw, u64 *bytenr_ret)
> +{
> +	u64 wp;
> +	int ret;
> +
> +	if (zones[0].type == BLK_ZONE_TYPE_CONVENTIONAL) {
> +		*bytenr_ret = zones[0].start << SECTOR_SHIFT;
> +		return 0;
> +	}
> +
> +	ret = sb_write_pointer(bdev, zones, &wp);
> +	if (ret != -ENOENT && ret < 0)
> +		return ret;
> +
> +	if (rw == WRITE) {
> +		struct blk_zone *reset = NULL;
> +
> +		if (wp == zones[0].start << SECTOR_SHIFT)
> +			reset = &zones[0];
> +		else if (wp == zones[1].start << SECTOR_SHIFT)
> +			reset = &zones[1];
> +
> +		if (reset && reset->cond != BLK_ZONE_COND_EMPTY) {
> +			ASSERT(reset->cond == BLK_ZONE_COND_FULL);
> +
> +			ret = blkdev_zone_mgmt(bdev, REQ_OP_ZONE_RESET,
> +					       reset->start, reset->len,
> +					       GFP_NOFS);

What happens if we crash right after this?  Is the WP set to the start of the 
zone here?  Does this mean we'll simply miss the super block?  I understand 
we're resetting one zone here, but we're doing this in order, so we'll reset one 
and write one, then reset the other and write the next.  We don't wait until 
we've issued the writes for everything, so it appears to me that there's a gap 
where we could have the WP pointed at the start of the zone, which we view as an 
invalid state and thus won't be able to mount the file system.  Or am I missing 
something?  Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 11/41] btrfs: implement log-structured superblock for ZONED mode
  2020-11-02 18:53       ` Johannes Thumshirn
@ 2020-11-02 19:01         ` Josef Bacik
  2020-11-02 19:31           ` Johannes Thumshirn
  0 siblings, 1 reply; 119+ messages in thread
From: Josef Bacik @ 2020-11-02 19:01 UTC (permalink / raw)
  To: Johannes Thumshirn, Naohiro Aota, linux-btrfs, dsterba
  Cc: hare, linux-fsdevel

On 11/2/20 1:53 PM, Johannes Thumshirn wrote:
> On 02/11/2020 19:23, Josef Bacik wrote:
>>> +		/* shouldn't have super stripes in sequential zones */
>>> +		if (zoned && nr) {
>>> +			btrfs_err(fs_info,
>>> +				  "Zoned btrfs's block group %llu should not have super blocks",
>>> +				  cache->start);
>>> +			return -EUCLEAN;
>>> +		}
>>> +
>> I'm very confused about this check, namely how you've been able to test without
>> it blowing up, which makes me feel like I'm missing something.
>>
>> We _always_ call exclude_super_stripes(), and we're simply looking up the bytenr
>> for that block, which appears to not do anything special for zoned.  This should
>> be looking up and failing whenever it looks for super stripes far enough out.
>> How are you not failing here everytime you mount the fs?  Thanks,
> 
> Naohiro (or Josef and everyone else as well of cause), please correct me if I'm
> wrong, but on zoned btrfs we're not supporting any RAID type. So the call to
> btrfs_rmap_block() above will return 'nr = 0' (as we're always having
> map->num_stripes = 1) so this won't evaluate to true.
> 

No it should return nr == 1 in the single case.  This maps physical address to a 
logical address in the block group, so it could be multiple, but if that bytenr 
falls inside the block group it'll return with something set.  Hence my 
confusion.  Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 11/41] btrfs: implement log-structured superblock for ZONED mode
  2020-11-02 19:01         ` Josef Bacik
@ 2020-11-02 19:31           ` Johannes Thumshirn
  0 siblings, 0 replies; 119+ messages in thread
From: Johannes Thumshirn @ 2020-11-02 19:31 UTC (permalink / raw)
  To: Josef Bacik, Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 02/11/2020 20:02, Josef Bacik wrote:
> No it should return nr == 1 in the single case.  This maps physical address to a 
> logical address in the block group, so it could be multiple, but if that bytenr 
> falls inside the block group it'll return with something set.  Hence my 
> confusion.

OK so from my debugging [1] it looks like we're hitting the !in_range() continue
case in __btrfs_rmap_block()'s loop.

But I'll need to defer to Naohiro to answer this question.

[1]:
mount -t btrfs /dev/nullb0 /mnt/test                                                                                                                                                
[    2.189080] BTRFS error (device nullb0): exclude_super_stripes: calling btrfs_rmap_block() for bytenr: 65536                                                                       
[    2.191168] BTRFS error (device nullb0): __btrfs_rmap_block: !in_range(65536, 536870912, 268435456)
[    2.193068] BTRFS error (device nullb0): __btrfs_rmap_block: nr: 0, *naddrs: 0                                                                                                     
[    2.194603] BTRFS error (device nullb0): exclude_super_stripes: nr: 0                                                                                                              
[    2.195973] BTRFS error (device nullb0): exclude_super_stripes: calling btrfs_rmap_block() for bytenr: 67108864                                                                    
[    2.197378] BTRFS error (device nullb0): __btrfs_rmap_block: !in_range(67108864, 536870912, 268435456)
[    2.198382] BTRFS error (device nullb0): __btrfs_rmap_block: nr: 0, *naddrs: 0
[    2.199160] BTRFS error (device nullb0): exclude_super_stripes: nr: 0                                                                                                              
[    2.199871] BTRFS error (device nullb0): exclude_super_stripes: calling btrfs_rmap_block() for bytenr: 274877906944                                                                
[    2.201030] BTRFS error (device nullb0): __btrfs_rmap_block: !in_range(274877906944, 536870912, 268435456)
[    2.202088] BTRFS error (device nullb0): __btrfs_rmap_block: nr: 0, *naddrs: 0
[    2.202864] BTRFS error (device nullb0): exclude_super_stripes: nr: 0                                                                                                              
[    2.203549] BTRFS error (device nullb0): exclude_super_stripes: calling btrfs_rmap_block() for bytenr: 65536                                                                       
[    2.204621] BTRFS error (device nullb0): __btrfs_rmap_block: !in_range(65536, 805306368, 268435456)
[    2.205590] BTRFS error (device nullb0): __btrfs_rmap_block: nr: 0, *naddrs: 0
[    2.206394] BTRFS error (device nullb0): exclude_super_stripes: nr: 0
[    2.207078] BTRFS error (device nullb0): exclude_super_stripes: calling btrfs_rmap_block() for bytenr: 67108864
[    2.208131] BTRFS error (device nullb0): __btrfs_rmap_block: !in_range(67108864, 805306368, 268435456)
[    2.209111] BTRFS error (device nullb0): __btrfs_rmap_block: nr: 0, *naddrs: 0
[    2.209885] BTRFS error (device nullb0): exclude_super_stripes: nr: 0
[    2.210540] BTRFS error (device nullb0): exclude_super_stripes: calling btrfs_rmap_block() for bytenr: 274877906944
[    2.211595] BTRFS error (device nullb0): __btrfs_rmap_block: !in_range(274877906944, 805306368, 268435456)
[    2.212620] BTRFS error (device nullb0): __btrfs_rmap_block: nr: 0, *naddrs: 0
[    2.213388] BTRFS error (device nullb0): exclude_super_stripes: nr: 0
[    2.214076] BTRFS error (device nullb0): exclude_super_stripes: calling btrfs_rmap_block() for bytenr: 65536
[    2.215079] BTRFS error (device nullb0): __btrfs_rmap_block: !in_range(65536, 1073741824, 268435456)
[    2.216039] BTRFS error (device nullb0): __btrfs_rmap_block: nr: 0, *naddrs: 0
[    2.216801] BTRFS error (device nullb0): exclude_super_stripes: nr: 0
[    2.217491] BTRFS error (device nullb0): exclude_super_stripes: calling btrfs_rmap_block() for bytenr: 67108864
[    2.218548] BTRFS error (device nullb0): __btrfs_rmap_block: !in_range(67108864, 1073741824, 268435456)
[    2.219537] BTRFS error (device nullb0): __btrfs_rmap_block: nr: 0, *naddrs: 0
[    2.220322] BTRFS error (device nullb0): exclude_super_stripes: nr: 0
[    2.221020] BTRFS error (device nullb0): exclude_super_stripes: calling btrfs_rmap_block() for bytenr: 274877906944
[    2.222150] BTRFS error (device nullb0): __btrfs_rmap_block: !in_range(274877906944, 1073741824, 268435456)
[    2.223165] BTRFS error (device nullb0): __btrfs_rmap_block: nr: 0, *naddrs: 0
[    2.223945] BTRFS error (device nullb0): exclude_super_stripes: nr: 0

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 12/41] btrfs: implement zoned chunk allocator
  2020-10-30 13:51   ` [PATCH v9 12/41] btrfs: implement zoned chunk allocator Naohiro Aota
@ 2020-11-02 20:09     ` Josef Bacik
  2020-11-02 22:21       ` Naohiro Aota
  2020-11-03 13:23     ` David Sterba
  1 sibling, 1 reply; 119+ messages in thread
From: Josef Bacik @ 2020-11-02 20:09 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> This commit implements a zoned chunk/dev_extent allocator. The zoned
> allocator aligns the device extents to zone boundaries, so that a zone
> reset affects only the device extent and does not change the state of
> blocks in the neighbor device extents.
> 
> Also, it checks that a region allocation is not overlapping any of the
> super block zones, and ensures the region is empty.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> ---
>   fs/btrfs/volumes.c | 131 +++++++++++++++++++++++++++++++++++++++++++++
>   fs/btrfs/volumes.h |   1 +
>   fs/btrfs/zoned.c   | 126 +++++++++++++++++++++++++++++++++++++++++++
>   fs/btrfs/zoned.h   |  30 +++++++++++
>   4 files changed, 288 insertions(+)
> 
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index db884b96a5ea..78c62ef02e6f 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -1416,6 +1416,14 @@ static bool contains_pending_extent(struct btrfs_device *device, u64 *start,
>   	return false;
>   }
>   
> +static inline u64 dev_extent_search_start_zoned(struct btrfs_device *device,
> +						u64 start)
> +{
> +	start = max_t(u64, start,
> +		      max_t(u64, device->zone_info->zone_size, SZ_1M));
> +	return btrfs_zone_align(device, start);
> +}
> +
>   static u64 dev_extent_search_start(struct btrfs_device *device, u64 start)
>   {
>   	switch (device->fs_devices->chunk_alloc_policy) {
> @@ -1426,11 +1434,57 @@ static u64 dev_extent_search_start(struct btrfs_device *device, u64 start)
>   		 * make sure to start at an offset of at least 1MB.
>   		 */
>   		return max_t(u64, start, SZ_1M);
> +	case BTRFS_CHUNK_ALLOC_ZONED:
> +		return dev_extent_search_start_zoned(device, start);
>   	default:
>   		BUG();
>   	}
>   }
>   
> +static bool dev_extent_hole_check_zoned(struct btrfs_device *device,
> +					u64 *hole_start, u64 *hole_size,
> +					u64 num_bytes)
> +{
> +	u64 zone_size = device->zone_info->zone_size;
> +	u64 pos;
> +	int ret;
> +	int changed = 0;
> +
> +	ASSERT(IS_ALIGNED(*hole_start, zone_size));
> +
> +	while (*hole_size > 0) {
> +		pos = btrfs_find_allocatable_zones(device, *hole_start,
> +						   *hole_start + *hole_size,
> +						   num_bytes);
> +		if (pos != *hole_start) {
> +			*hole_size = *hole_start + *hole_size - pos;
> +			*hole_start = pos;
> +			changed = 1;
> +			if (*hole_size < num_bytes)
> +				break;
> +		}
> +
> +		ret = btrfs_ensure_empty_zones(device, pos, num_bytes);
> +
> +		/* range is ensured to be empty */
> +		if (!ret)
> +			return changed;
> +
> +		/* given hole range was invalid (outside of device) */
> +		if (ret == -ERANGE) {
> +			*hole_start += *hole_size;
> +			*hole_size = 0;
> +			return 1;
> +		}
> +
> +		*hole_start += zone_size;
> +		*hole_size -= zone_size;
> +		changed = 1;
> +	}
> +
> +	return changed;
> +}
> +
>   /**
>    * dev_extent_hole_check - check if specified hole is suitable for allocation
>    * @device:	the device which we have the hole
> @@ -1463,6 +1517,10 @@ static bool dev_extent_hole_check(struct btrfs_device *device, u64 *hole_start,
>   	case BTRFS_CHUNK_ALLOC_REGULAR:
>   		/* No extra check */
>   		break;
> +	case BTRFS_CHUNK_ALLOC_ZONED:
> +		changed |= dev_extent_hole_check_zoned(device, hole_start,
> +						       hole_size, num_bytes);
I'm confused here, we check to make sure the pending stuff doesn't overlap with 
non-empty zones.  However we don't ever actually mark zones as non-empty except 
on mount.  I realize that if we allocate this zone then it appears pending and 
thus we won't allocate with this zone again while the fs is mounted, but it took 
me a while to realize this.  Is there a reason to not mark a zone as non-empty 
when we allocate from it?


> +		break;
>   	default:
>   		BUG();
>   	}
> @@ -1517,6 +1575,9 @@ static int find_free_dev_extent_start(struct btrfs_device *device,
>   
>   	search_start = dev_extent_search_start(device, search_start);
>   
> +	WARN_ON(device->zone_info &&
> +		!IS_ALIGNED(num_bytes, device->zone_info->zone_size));
> +
>   	path = btrfs_alloc_path();
>   	if (!path)
>   		return -ENOMEM;
> @@ -4907,6 +4968,37 @@ static void init_alloc_chunk_ctl_policy_regular(
>   	ctl->dev_extent_min = BTRFS_STRIPE_LEN * ctl->dev_stripes;
>   }
>   
> +static void
> +init_alloc_chunk_ctl_policy_zoned(struct btrfs_fs_devices *fs_devices,
> +				  struct alloc_chunk_ctl *ctl)
> +{
> +	u64 zone_size = fs_devices->fs_info->zone_size;
> +	u64 limit;
> +	int min_num_stripes = ctl->devs_min * ctl->dev_stripes;
> +	int min_data_stripes = (min_num_stripes - ctl->nparity) / ctl->ncopies;
> +	u64 min_chunk_size = min_data_stripes * zone_size;
> +	u64 type = ctl->type;
> +
> +	ctl->max_stripe_size = zone_size;
> +	if (type & BTRFS_BLOCK_GROUP_DATA) {
> +		ctl->max_chunk_size = round_down(BTRFS_MAX_DATA_CHUNK_SIZE,
> +						 zone_size);
> +	} else if (type & BTRFS_BLOCK_GROUP_METADATA) {
> +		ctl->max_chunk_size = ctl->max_stripe_size;
> +	} else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
> +		ctl->max_chunk_size = 2 * ctl->max_stripe_size;
> +		ctl->devs_max = min_t(int, ctl->devs_max,
> +				      BTRFS_MAX_DEVS_SYS_CHUNK);
> +	}
> +
> +	/* We don't want a chunk larger than 10% of writable space */
> +	limit = max(round_down(div_factor(fs_devices->total_rw_bytes, 1),
> +			       zone_size),
> +		    min_chunk_size);
> +	ctl->max_chunk_size = min(limit, ctl->max_chunk_size);
> +	ctl->dev_extent_min = zone_size * ctl->dev_stripes;
> +}
> +
>   static void init_alloc_chunk_ctl(struct btrfs_fs_devices *fs_devices,
>   				 struct alloc_chunk_ctl *ctl)
>   {
> @@ -4927,6 +5019,9 @@ static void init_alloc_chunk_ctl(struct btrfs_fs_devices *fs_devices,
>   	case BTRFS_CHUNK_ALLOC_REGULAR:
>   		init_alloc_chunk_ctl_policy_regular(fs_devices, ctl);
>   		break;
> +	case BTRFS_CHUNK_ALLOC_ZONED:
> +		init_alloc_chunk_ctl_policy_zoned(fs_devices, ctl);
> +		break;
>   	default:
>   		BUG();
>   	}
> @@ -5053,6 +5148,40 @@ static int decide_stripe_size_regular(struct alloc_chunk_ctl *ctl,
>   	return 0;
>   }
>   
> +static int decide_stripe_size_zoned(struct alloc_chunk_ctl *ctl,
> +				    struct btrfs_device_info *devices_info)
> +{
> +	u64 zone_size = devices_info[0].dev->zone_info->zone_size;
> +	/* number of stripes that count for block group size */
> +	int data_stripes;
> +
> +	/*
> +	 * It should hold because:
> +	 *    dev_extent_min == dev_extent_want == zone_size * dev_stripes
> +	 */
> +	ASSERT(devices_info[ctl->ndevs - 1].max_avail == ctl->dev_extent_min);
> +
> +	ctl->stripe_size = zone_size;
> +	ctl->num_stripes = ctl->ndevs * ctl->dev_stripes;
> +	data_stripes = (ctl->num_stripes - ctl->nparity) / ctl->ncopies;
> +
> +	/*
> +	 * stripe_size is fixed in ZONED. Reduce ndevs instead.
> +	 */
> +	if (ctl->stripe_size * data_stripes > ctl->max_chunk_size) {
> +		ctl->ndevs = div_u64(div_u64(ctl->max_chunk_size * ctl->ncopies,
> +					     ctl->stripe_size) + ctl->nparity,
> +				     ctl->dev_stripes);
> +		ctl->num_stripes = ctl->ndevs * ctl->dev_stripes;
> +		data_stripes = (ctl->num_stripes - ctl->nparity) / ctl->ncopies;
> +		ASSERT(ctl->stripe_size * data_stripes <= ctl->max_chunk_size);
> +	}
> +
> +	ctl->chunk_size = ctl->stripe_size * data_stripes;
> +
> +	return 0;
> +}
> +
>   static int decide_stripe_size(struct btrfs_fs_devices *fs_devices,
>   			      struct alloc_chunk_ctl *ctl,
>   			      struct btrfs_device_info *devices_info)
> @@ -5080,6 +5209,8 @@ static int decide_stripe_size(struct btrfs_fs_devices *fs_devices,
>   	switch (fs_devices->chunk_alloc_policy) {
>   	case BTRFS_CHUNK_ALLOC_REGULAR:
>   		return decide_stripe_size_regular(ctl, devices_info);
> +	case BTRFS_CHUNK_ALLOC_ZONED:
> +		return decide_stripe_size_zoned(ctl, devices_info);
>   	default:
>   		BUG();
>   	}
> diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
> index 9c07b97a2260..0249aca668fb 100644
> --- a/fs/btrfs/volumes.h
> +++ b/fs/btrfs/volumes.h
> @@ -213,6 +213,7 @@ BTRFS_DEVICE_GETSET_FUNCS(bytes_used);
>   
>   enum btrfs_chunk_allocation_policy {
>   	BTRFS_CHUNK_ALLOC_REGULAR,
> +	BTRFS_CHUNK_ALLOC_ZONED,
>   };
>   
>   struct btrfs_fs_devices {
> diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
> index d5487cba203b..4411d786597a 100644
> --- a/fs/btrfs/zoned.c
> +++ b/fs/btrfs/zoned.c
> @@ -1,11 +1,13 @@
>   // SPDX-License-Identifier: GPL-2.0
>   
> +#include <linux/bitops.h>
>   #include <linux/slab.h>
>   #include <linux/blkdev.h>
>   #include "ctree.h"
>   #include "volumes.h"
>   #include "zoned.h"
>   #include "rcu-string.h"
> +#include "disk-io.h"
>   
>   /* Maximum number of zones to report per blkdev_report_zones() call */
>   #define BTRFS_REPORT_NR_ZONES   4096
> @@ -328,6 +330,7 @@ int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
>   
>   	fs_info->zone_size = zone_size;
>   	fs_info->max_zone_append_size = max_zone_append_size;
> +	fs_info->fs_devices->chunk_alloc_policy = BTRFS_CHUNK_ALLOC_ZONED;
>   
>   	btrfs_info(fs_info, "ZONED mode enabled, zone size %llu B",
>   		   fs_info->zone_size);
> @@ -607,3 +610,126 @@ int btrfs_reset_sb_log_zones(struct block_device *bdev, int mirror)
>   				sb_zone << zone_sectors_shift, zone_sectors * 2,
>   				GFP_NOFS);
>   }
> +
> +/*
> + * btrfs_check_allocatable_zones - find allocatable zones within give region
> + * @device:	the device to allocate a region
> + * @hole_start: the position of the hole to allocate the region
> + * @num_bytes:	the size of wanted region
> + * @hole_size:	the size of hole
> + *
> + * Allocatable region should not contain any superblock locations.
> + */
> +u64 btrfs_find_allocatable_zones(struct btrfs_device *device, u64 hole_start,
> +				 u64 hole_end, u64 num_bytes)
> +{
> +	struct btrfs_zoned_device_info *zinfo = device->zone_info;
> +	u8 shift = zinfo->zone_size_shift;
> +	u64 nzones = num_bytes >> shift;
> +	u64 pos = hole_start;
> +	u64 begin, end;
> +	u64 sb_pos;
> +	bool have_sb;
> +	int i;
> +
> +	ASSERT(IS_ALIGNED(hole_start, zinfo->zone_size));
> +	ASSERT(IS_ALIGNED(num_bytes, zinfo->zone_size));
> +
> +	while (pos < hole_end) {
> +		begin = pos >> shift;
> +		end = begin + nzones;
> +
> +		if (end > zinfo->nr_zones)
> +			return hole_end;
> +
> +		/* check if zones in the region are all empty */
> +		if (btrfs_dev_is_sequential(device, pos) &&
> +		    find_next_zero_bit(zinfo->empty_zones, end, begin) != end) {
> +			pos += zinfo->zone_size;
> +			continue;
> +		}
> +
> +		have_sb = false;
> +		for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
> +			sb_pos = sb_zone_number(zinfo->zone_size, i);
> +			if (!(end < sb_pos || sb_pos + 1 < begin)) {
> +				have_sb = true;
> +				pos = (sb_pos + 2) << shift;
> +				break;
> +			}
> +		}
> +		if (!have_sb)
> +			break;
> +	}
> +
> +	return pos;
> +}
> +
> +int btrfs_reset_device_zone(struct btrfs_device *device, u64 physical,
> +			    u64 length, u64 *bytes)
> +{
> +	int ret;
> +
> +	*bytes = 0;
> +	ret = blkdev_zone_mgmt(device->bdev, REQ_OP_ZONE_RESET,
> +			       physical >> SECTOR_SHIFT, length >> SECTOR_SHIFT,
> +			       GFP_NOFS);
> +	if (ret)
> +		return ret;
> +
> +	*bytes = length;
> +	while (length) {
> +		btrfs_dev_set_zone_empty(device, physical);
> +		physical += device->zone_info->zone_size;
> +		length -= device->zone_info->zone_size;
> +	}
> +
> +	return 0;
> +}
> +
> +int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size)
> +{
> +	struct btrfs_zoned_device_info *zinfo = device->zone_info;
> +	u8 shift = zinfo->zone_size_shift;
> +	unsigned long begin = start >> shift;
> +	unsigned long end = (start + size) >> shift;
> +	u64 pos;
> +	int ret;
> +
> +	ASSERT(IS_ALIGNED(start, zinfo->zone_size));
> +	ASSERT(IS_ALIGNED(size, zinfo->zone_size));
> +
> +	if (end > zinfo->nr_zones)
> +		return -ERANGE;
> +
> +	/* all the zones are conventional */
> +	if (find_next_bit(zinfo->seq_zones, begin, end) == end)
> +		return 0;
> +

This check is duplicated below.

> +	/* all the zones are sequential and empty */
> +	if (find_next_zero_bit(zinfo->seq_zones, begin, end) == end &&
> +	    find_next_zero_bit(zinfo->empty_zones, begin, end) == end)
> +		return 0;
> +
> +	for (pos = start; pos < start + size; pos += zinfo->zone_size) {
> +		u64 reset_bytes;
> +
> +		if (!btrfs_dev_is_sequential(device, pos) ||
> +		    btrfs_dev_is_empty_zone(device, pos))
> +			continue;
> +
> +		/* free regions should be empty */
> +		btrfs_warn_in_rcu(
> +			device->fs_info,
> +			"resetting device %s zone %llu for allocation",
> +			rcu_str_deref(device->name), pos >> shift);
> +		WARN_ON_ONCE(1);
> +
> +		ret = btrfs_reset_device_zone(device, pos, zinfo->zone_size,
> +					      &reset_bytes);
> +		if (ret)
> +			return ret;

This seems bad, as we could just have corruption right?  So we're resetting the 
zone which could lose us data right?  Shouldn't we just bail here?  Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 13/41] btrfs: verify device extent is aligned to zone
  2020-10-30 13:51   ` [PATCH v9 13/41] btrfs: verify device extent is aligned to zone Naohiro Aota
@ 2020-11-02 20:14     ` Josef Bacik
  0 siblings, 0 replies; 119+ messages in thread
From: Josef Bacik @ 2020-11-02 20:14 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> Add a check in verify_one_dev_extent() to check if a device extent on a
> zoned block device is aligned to the respective zone boundary.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 14/41] btrfs: load zone's alloction offset
  2020-10-30 13:51   ` [PATCH v9 14/41] btrfs: load zone's alloction offset Naohiro Aota
@ 2020-11-02 20:25     ` Josef Bacik
  2020-11-02 20:29       ` Josef Bacik
  2020-11-02 22:40       ` Naohiro Aota
  2020-11-03 13:28     ` David Sterba
  1 sibling, 2 replies; 119+ messages in thread
From: Josef Bacik @ 2020-11-02 20:25 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> Zoned btrfs must allocate blocks at the zones' write pointer. The device's
> write pointer position can be mapped to a logical address within a block
> group. This commit adds "alloc_offset" to track the logical address.
> 
> This logical address is populated in btrfs_load_block-group_zone_info()

btrfs_load_block_group_zone_info()

> from write pointers of corresponding zones.
> 
> For now, zoned btrfs only support the SINGLE profile. Supporting non-SINGLE
> profile with zone append writing is not trivial. For example, in the DUP
> profile, we send a zone append writing IO to two zones on a device. The
> device reply with written LBAs for the IOs. If the offsets of the returned
> addresses from the beginning of the zone are different, then it results in
> different logical addresses.
> 
> We need fine-grained logical to physical mapping to support such separated
> physical address issue. Since it should require additional metadata type,
> disable non-SINGLE profiles for now.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> ---
>   fs/btrfs/block-group.c |  15 ++++
>   fs/btrfs/block-group.h |   6 ++
>   fs/btrfs/zoned.c       | 153 +++++++++++++++++++++++++++++++++++++++++
>   fs/btrfs/zoned.h       |   6 ++
>   4 files changed, 180 insertions(+)
> 
> diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
> index e989c66aa764..920b2708c7f2 100644
> --- a/fs/btrfs/block-group.c
> +++ b/fs/btrfs/block-group.c
> @@ -15,6 +15,7 @@
>   #include "delalloc-space.h"
>   #include "discard.h"
>   #include "raid56.h"
> +#include "zoned.h"
>   
>   /*
>    * Return target flags in extended format or 0 if restripe for this chunk_type
> @@ -1935,6 +1936,13 @@ static int read_one_block_group(struct btrfs_fs_info *info,
>   			goto error;
>   	}
>   
> +	ret = btrfs_load_block_group_zone_info(cache);
> +	if (ret) {
> +		btrfs_err(info, "failed to load zone info of bg %llu",
> +			  cache->start);
> +		goto error;
> +	}
> +
>   	/*
>   	 * We need to exclude the super stripes now so that the space info has
>   	 * super bytes accounted for, otherwise we'll think we have more space
> @@ -2161,6 +2169,13 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans, u64 bytes_used,
>   	cache->last_byte_to_unpin = (u64)-1;
>   	cache->cached = BTRFS_CACHE_FINISHED;
>   	cache->needs_free_space = 1;
> +
> +	ret = btrfs_load_block_group_zone_info(cache);
> +	if (ret) {
> +		btrfs_put_block_group(cache);
> +		return ret;
> +	}
> +
>   	ret = exclude_super_stripes(cache);
>   	if (ret) {
>   		/* We may have excluded something, so call this just in case */
> diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
> index adfd7583a17b..14e3043c9ce7 100644
> --- a/fs/btrfs/block-group.h
> +++ b/fs/btrfs/block-group.h
> @@ -183,6 +183,12 @@ struct btrfs_block_group {
>   
>   	/* Record locked full stripes for RAID5/6 block group */
>   	struct btrfs_full_stripe_locks_tree full_stripe_locks_root;
> +
> +	/*
> +	 * Allocation offset for the block group to implement sequential
> +	 * allocation. This is used only with ZONED mode enabled.
> +	 */
> +	u64 alloc_offset;
>   };
>   
>   static inline u64 btrfs_block_group_end(struct btrfs_block_group *block_group)
> diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
> index 4411d786597a..0aa821893a51 100644
> --- a/fs/btrfs/zoned.c
> +++ b/fs/btrfs/zoned.c
> @@ -3,14 +3,20 @@
>   #include <linux/bitops.h>
>   #include <linux/slab.h>
>   #include <linux/blkdev.h>
> +#include <linux/sched/mm.h>
>   #include "ctree.h"
>   #include "volumes.h"
>   #include "zoned.h"
>   #include "rcu-string.h"
>   #include "disk-io.h"
> +#include "block-group.h"
>   
>   /* Maximum number of zones to report per blkdev_report_zones() call */
>   #define BTRFS_REPORT_NR_ZONES   4096
> +/* Invalid allocation pointer value for missing devices */
> +#define WP_MISSING_DEV ((u64)-1)
> +/* Pseudo write pointer value for conventional zone */
> +#define WP_CONVENTIONAL ((u64)-2)
>   
>   static int copy_zone_info_cb(struct blk_zone *zone, unsigned int idx,
>   			     void *data)
> @@ -733,3 +739,150 @@ int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size)
>   
>   	return 0;
>   }
> +
> +int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache)
> +{
> +	struct btrfs_fs_info *fs_info = cache->fs_info;
> +	struct extent_map_tree *em_tree = &fs_info->mapping_tree;
> +	struct extent_map *em;
> +	struct map_lookup *map;
> +	struct btrfs_device *device;
> +	u64 logical = cache->start;
> +	u64 length = cache->length;
> +	u64 physical = 0;
> +	int ret;
> +	int i;
> +	unsigned int nofs_flag;
> +	u64 *alloc_offsets = NULL;
> +	u32 num_sequential = 0, num_conventional = 0;
> +
> +	if (!btrfs_is_zoned(fs_info))
> +		return 0;
> +
> +	/* Sanity check */
> +	if (!IS_ALIGNED(length, fs_info->zone_size)) {
> +		btrfs_err(fs_info, "unaligned block group at %llu + %llu",
> +			  logical, length);
> +		return -EIO;
> +	}
> +
> +	/* Get the chunk mapping */
> +	read_lock(&em_tree->lock);
> +	em = lookup_extent_mapping(em_tree, logical, length);
> +	read_unlock(&em_tree->lock);
> +
> +	if (!em)
> +		return -EINVAL;
> +
> +	map = em->map_lookup;
> +
> +	/*
> +	 * Get the zone type: if the group is mapped to a non-sequential zone,
> +	 * there is no need for the allocation offset (fit allocation is OK).
> +	 */
> +	alloc_offsets = kcalloc(map->num_stripes, sizeof(*alloc_offsets),
> +				GFP_NOFS);
> +	if (!alloc_offsets) {
> +		free_extent_map(em);
> +		return -ENOMEM;
> +	}
> +
> +	for (i = 0; i < map->num_stripes; i++) {
> +		bool is_sequential;
> +		struct blk_zone zone;
> +
> +		device = map->stripes[i].dev;
> +		physical = map->stripes[i].physical;
> +
> +		if (device->bdev == NULL) {
> +			alloc_offsets[i] = WP_MISSING_DEV;
> +			continue;
> +		}
> +
> +		is_sequential = btrfs_dev_is_sequential(device, physical);
> +		if (is_sequential)
> +			num_sequential++;
> +		else
> +			num_conventional++;
> +
> +		if (!is_sequential) {
> +			alloc_offsets[i] = WP_CONVENTIONAL;
> +			continue;
> +		}
> +
> +		/*
> +		 * This zone will be used for allocation, so mark this
> +		 * zone non-empty.
> +		 */
> +		btrfs_dev_clear_zone_empty(device, physical);
> +
> +		/*
> +		 * The group is mapped to a sequential zone. Get the zone write
> +		 * pointer to determine the allocation offset within the zone.
> +		 */
> +		WARN_ON(!IS_ALIGNED(physical, fs_info->zone_size));
> +		nofs_flag = memalloc_nofs_save();
> +		ret = btrfs_get_dev_zone(device, physical, &zone);
> +		memalloc_nofs_restore(nofs_flag);
> +		if (ret == -EIO || ret == -EOPNOTSUPP) {
> +			ret = 0;
> +			alloc_offsets[i] = WP_MISSING_DEV;
> +			continue;
> +		} else if (ret) {
> +			goto out;
> +		}
> +
> +		switch (zone.cond) {
> +		case BLK_ZONE_COND_OFFLINE:
> +		case BLK_ZONE_COND_READONLY:
> +			btrfs_err(fs_info, "Offline/readonly zone %llu",
> +				  physical >> device->zone_info->zone_size_shift);
> +			alloc_offsets[i] = WP_MISSING_DEV;
> +			break;
> +		case BLK_ZONE_COND_EMPTY:
> +			alloc_offsets[i] = 0;
> +			break;
> +		case BLK_ZONE_COND_FULL:
> +			alloc_offsets[i] = fs_info->zone_size;
> +			break;
> +		default:
> +			/* Partially used zone */
> +			alloc_offsets[i] =
> +				((zone.wp - zone.start) << SECTOR_SHIFT);
> +			break;
> +		}
> +	}
> +
> +	if (num_conventional > 0) {
> +		/*
> +		 * Since conventional zones does not have write pointer, we
> +		 * cannot determine alloc_offset from the pointer
> +		 */
> +		ret = -EINVAL;
> +		goto out;
> +	}

Does this mean we can't have zoned with a device that has conventional and 
sequential zones?  I thought such things existed currently?  Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 14/41] btrfs: load zone's alloction offset
  2020-11-02 20:25     ` Josef Bacik
@ 2020-11-02 20:29       ` Josef Bacik
  2020-11-02 22:43         ` Naohiro Aota
  2020-11-02 22:40       ` Naohiro Aota
  1 sibling, 1 reply; 119+ messages in thread
From: Josef Bacik @ 2020-11-02 20:29 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 11/2/20 3:25 PM, Josef Bacik wrote:
> On 10/30/20 9:51 AM, Naohiro Aota wrote:
>> Zoned btrfs must allocate blocks at the zones' write pointer. The device's
>> write pointer position can be mapped to a logical address within a block
>> group. This commit adds "alloc_offset" to track the logical address.
>>
>> This logical address is populated in btrfs_load_block-group_zone_info()
> 
> btrfs_load_block_group_zone_info()
> 
>> from write pointers of corresponding zones.
>>
>> For now, zoned btrfs only support the SINGLE profile. Supporting non-SINGLE
>> profile with zone append writing is not trivial. For example, in the DUP
>> profile, we send a zone append writing IO to two zones on a device. The
>> device reply with written LBAs for the IOs. If the offsets of the returned
>> addresses from the beginning of the zone are different, then it results in
>> different logical addresses.
>>
>> We need fine-grained logical to physical mapping to support such separated
>> physical address issue. Since it should require additional metadata type,
>> disable non-SINGLE profiles for now.
>>
>> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
>> ---
>>   fs/btrfs/block-group.c |  15 ++++
>>   fs/btrfs/block-group.h |   6 ++
>>   fs/btrfs/zoned.c       | 153 +++++++++++++++++++++++++++++++++++++++++
>>   fs/btrfs/zoned.h       |   6 ++
>>   4 files changed, 180 insertions(+)
>>
>> diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
>> index e989c66aa764..920b2708c7f2 100644
>> --- a/fs/btrfs/block-group.c
>> +++ b/fs/btrfs/block-group.c
>> @@ -15,6 +15,7 @@
>>   #include "delalloc-space.h"
>>   #include "discard.h"
>>   #include "raid56.h"
>> +#include "zoned.h"
>>   /*
>>    * Return target flags in extended format or 0 if restripe for this chunk_type
>> @@ -1935,6 +1936,13 @@ static int read_one_block_group(struct btrfs_fs_info 
>> *info,
>>               goto error;
>>       }
>> +    ret = btrfs_load_block_group_zone_info(cache);
>> +    if (ret) {
>> +        btrfs_err(info, "failed to load zone info of bg %llu",
>> +              cache->start);
>> +        goto error;
>> +    }
>> +
>>       /*
>>        * We need to exclude the super stripes now so that the space info has
>>        * super bytes accounted for, otherwise we'll think we have more space
>> @@ -2161,6 +2169,13 @@ int btrfs_make_block_group(struct btrfs_trans_handle 
>> *trans, u64 bytes_used,
>>       cache->last_byte_to_unpin = (u64)-1;
>>       cache->cached = BTRFS_CACHE_FINISHED;
>>       cache->needs_free_space = 1;
>> +
>> +    ret = btrfs_load_block_group_zone_info(cache);
>> +    if (ret) {
>> +        btrfs_put_block_group(cache);
>> +        return ret;
>> +    }
>> +
>>       ret = exclude_super_stripes(cache);
>>       if (ret) {
>>           /* We may have excluded something, so call this just in case */
>> diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
>> index adfd7583a17b..14e3043c9ce7 100644
>> --- a/fs/btrfs/block-group.h
>> +++ b/fs/btrfs/block-group.h
>> @@ -183,6 +183,12 @@ struct btrfs_block_group {
>>       /* Record locked full stripes for RAID5/6 block group */
>>       struct btrfs_full_stripe_locks_tree full_stripe_locks_root;
>> +
>> +    /*
>> +     * Allocation offset for the block group to implement sequential
>> +     * allocation. This is used only with ZONED mode enabled.
>> +     */
>> +    u64 alloc_offset;
>>   };
>>   static inline u64 btrfs_block_group_end(struct btrfs_block_group *block_group)
>> diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
>> index 4411d786597a..0aa821893a51 100644
>> --- a/fs/btrfs/zoned.c
>> +++ b/fs/btrfs/zoned.c
>> @@ -3,14 +3,20 @@
>>   #include <linux/bitops.h>
>>   #include <linux/slab.h>
>>   #include <linux/blkdev.h>
>> +#include <linux/sched/mm.h>
>>   #include "ctree.h"
>>   #include "volumes.h"
>>   #include "zoned.h"
>>   #include "rcu-string.h"
>>   #include "disk-io.h"
>> +#include "block-group.h"
>>   /* Maximum number of zones to report per blkdev_report_zones() call */
>>   #define BTRFS_REPORT_NR_ZONES   4096
>> +/* Invalid allocation pointer value for missing devices */
>> +#define WP_MISSING_DEV ((u64)-1)
>> +/* Pseudo write pointer value for conventional zone */
>> +#define WP_CONVENTIONAL ((u64)-2)
>>   static int copy_zone_info_cb(struct blk_zone *zone, unsigned int idx,
>>                    void *data)
>> @@ -733,3 +739,150 @@ int btrfs_ensure_empty_zones(struct btrfs_device 
>> *device, u64 start, u64 size)
>>       return 0;
>>   }
>> +
>> +int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache)
>> +{
>> +    struct btrfs_fs_info *fs_info = cache->fs_info;
>> +    struct extent_map_tree *em_tree = &fs_info->mapping_tree;
>> +    struct extent_map *em;
>> +    struct map_lookup *map;
>> +    struct btrfs_device *device;
>> +    u64 logical = cache->start;
>> +    u64 length = cache->length;
>> +    u64 physical = 0;
>> +    int ret;
>> +    int i;
>> +    unsigned int nofs_flag;
>> +    u64 *alloc_offsets = NULL;
>> +    u32 num_sequential = 0, num_conventional = 0;
>> +
>> +    if (!btrfs_is_zoned(fs_info))
>> +        return 0;
>> +
>> +    /* Sanity check */
>> +    if (!IS_ALIGNED(length, fs_info->zone_size)) {
>> +        btrfs_err(fs_info, "unaligned block group at %llu + %llu",
>> +              logical, length);
>> +        return -EIO;
>> +    }
>> +
>> +    /* Get the chunk mapping */
>> +    read_lock(&em_tree->lock);
>> +    em = lookup_extent_mapping(em_tree, logical, length);
>> +    read_unlock(&em_tree->lock);
>> +
>> +    if (!em)
>> +        return -EINVAL;
>> +
>> +    map = em->map_lookup;
>> +
>> +    /*
>> +     * Get the zone type: if the group is mapped to a non-sequential zone,
>> +     * there is no need for the allocation offset (fit allocation is OK).
>> +     */
>> +    alloc_offsets = kcalloc(map->num_stripes, sizeof(*alloc_offsets),
>> +                GFP_NOFS);
>> +    if (!alloc_offsets) {
>> +        free_extent_map(em);
>> +        return -ENOMEM;
>> +    }
>> +
>> +    for (i = 0; i < map->num_stripes; i++) {
>> +        bool is_sequential;
>> +        struct blk_zone zone;
>> +
>> +        device = map->stripes[i].dev;
>> +        physical = map->stripes[i].physical;
>> +
>> +        if (device->bdev == NULL) {
>> +            alloc_offsets[i] = WP_MISSING_DEV;
>> +            continue;
>> +        }
>> +
>> +        is_sequential = btrfs_dev_is_sequential(device, physical);
>> +        if (is_sequential)
>> +            num_sequential++;
>> +        else
>> +            num_conventional++;
>> +
>> +        if (!is_sequential) {
>> +            alloc_offsets[i] = WP_CONVENTIONAL;
>> +            continue;
>> +        }
>> +
>> +        /*
>> +         * This zone will be used for allocation, so mark this
>> +         * zone non-empty.
>> +         */
>> +        btrfs_dev_clear_zone_empty(device, physical);
>> +
>> +        /*
>> +         * The group is mapped to a sequential zone. Get the zone write
>> +         * pointer to determine the allocation offset within the zone.
>> +         */
>> +        WARN_ON(!IS_ALIGNED(physical, fs_info->zone_size));
>> +        nofs_flag = memalloc_nofs_save();
>> +        ret = btrfs_get_dev_zone(device, physical, &zone);
>> +        memalloc_nofs_restore(nofs_flag);
>> +        if (ret == -EIO || ret == -EOPNOTSUPP) {
>> +            ret = 0;
>> +            alloc_offsets[i] = WP_MISSING_DEV;
>> +            continue;
>> +        } else if (ret) {
>> +            goto out;
>> +        }
>> +
>> +        switch (zone.cond) {
>> +        case BLK_ZONE_COND_OFFLINE:
>> +        case BLK_ZONE_COND_READONLY:
>> +            btrfs_err(fs_info, "Offline/readonly zone %llu",
>> +                  physical >> device->zone_info->zone_size_shift);
>> +            alloc_offsets[i] = WP_MISSING_DEV;
>> +            break;
>> +        case BLK_ZONE_COND_EMPTY:
>> +            alloc_offsets[i] = 0;
>> +            break;
>> +        case BLK_ZONE_COND_FULL:
>> +            alloc_offsets[i] = fs_info->zone_size;
>> +            break;
>> +        default:
>> +            /* Partially used zone */
>> +            alloc_offsets[i] =
>> +                ((zone.wp - zone.start) << SECTOR_SHIFT);
>> +            break;
>> +        }
>> +    }
>> +
>> +    if (num_conventional > 0) {
>> +        /*
>> +         * Since conventional zones does not have write pointer, we
>> +         * cannot determine alloc_offset from the pointer
>> +         */
>> +        ret = -EINVAL;
>> +        goto out;
>> +    }
> 
> Does this mean we can't have zoned with a device that has conventional and 
> sequential zones?  I thought such things existed currently?  Thanks,

I see this changes in a follow up patch, ignore me, you can add

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 15/41] btrfs: emulate write pointer for conventional zones
  2020-10-30 13:51   ` [PATCH v9 15/41] btrfs: emulate write pointer for conventional zones Naohiro Aota
@ 2020-11-02 20:37     ` Josef Bacik
  2020-11-03  1:25       ` Naohiro Aota
  2020-11-03 13:32     ` David Sterba
  1 sibling, 1 reply; 119+ messages in thread
From: Josef Bacik @ 2020-11-02 20:37 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> Conventional zones do not have a write pointer, so we cannot use it to
> determine the allocation offset if a block group contains a conventional
> zone.
> 
> But instead, we can consider the end of the last allocated extent in the
> block group as an allocation offset.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> ---
>   fs/btrfs/zoned.c | 119 ++++++++++++++++++++++++++++++++++++++++++++---
>   1 file changed, 113 insertions(+), 6 deletions(-)
> 
> diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
> index 0aa821893a51..8f58d0853cc3 100644
> --- a/fs/btrfs/zoned.c
> +++ b/fs/btrfs/zoned.c
> @@ -740,6 +740,104 @@ int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size)
>   	return 0;
>   }
>   
> +static int emulate_write_pointer(struct btrfs_block_group *cache,
> +				 u64 *offset_ret)
> +{
> +	struct btrfs_fs_info *fs_info = cache->fs_info;
> +	struct btrfs_root *root = fs_info->extent_root;
> +	struct btrfs_path *path;
> +	struct extent_buffer *leaf;
> +	struct btrfs_key search_key;
> +	struct btrfs_key found_key;
> +	int slot;
> +	int ret;
> +	u64 length;
> +
> +	path = btrfs_alloc_path();
> +	if (!path)
> +		return -ENOMEM;
> +
> +	search_key.objectid = cache->start + cache->length;
> +	search_key.type = 0;
> +	search_key.offset = 0;
> +

You can just use 'key', don't have to use 'search_key'.

Also you don't check for things like BTRFS_TREE_BLOCK_REF_KEY or whatever in the 
case that we don't have an inline extent ref, so this could error out with a fs 
with lots of snapshots and different references.  What you need is to search 
back until you hit an BTRFS_METADATA_ITEM_KEY or a BTRFS_EXTENT_ITEM_KEY, and 
then check the offset of that thing.  Otherwise this will screw up.  Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 04/41] btrfs: Get zone information of zoned block devices
  2020-11-02 16:53     ` Josef Bacik
  2020-11-02 16:58       ` Johannes Thumshirn
@ 2020-11-02 21:07       ` Naohiro Aota
  1 sibling, 0 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-11-02 21:07 UTC (permalink / raw)
  To: Josef Bacik; +Cc: linux-btrfs, dsterba, hare, linux-fsdevel, Damien Le Moal

On Mon, Nov 02, 2020 at 11:53:35AM -0500, Josef Bacik wrote:
>On 10/30/20 9:51 AM, Naohiro Aota wrote:
>>If a zoned block device is found, get its zone information (number of zones
>>and zone size) using the new helper function btrfs_get_dev_zone_info().  To
>>avoid costly run-time zone report commands to test the device zones type
>>during block allocation, attach the seq_zones bitmap to the device
>>structure to indicate if a zone is sequential or accept random writes. Also
>>it attaches the empty_zones bitmap to indicate if a zone is empty or not.
>>
>>This patch also introduces the helper function btrfs_dev_is_sequential() to
>>test if the zone storing a block is a sequential write required zone and
>>btrfs_dev_is_empty_zone() to test if the zone is a empty zone.
>>
>>Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
>>Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
>>Reviewed-by: Josef Bacik <josef@toxicpanda.com>
>>---
>>  fs/btrfs/Makefile      |   1 +
>>  fs/btrfs/dev-replace.c |   5 ++
>>  fs/btrfs/super.c       |   5 ++
>>  fs/btrfs/volumes.c     |  19 ++++-
>>  fs/btrfs/volumes.h     |   4 +
>>  fs/btrfs/zoned.c       | 176 +++++++++++++++++++++++++++++++++++++++++
>>  fs/btrfs/zoned.h       |  86 ++++++++++++++++++++
>>  7 files changed, 294 insertions(+), 2 deletions(-)
>>  create mode 100644 fs/btrfs/zoned.c
>>  create mode 100644 fs/btrfs/zoned.h
>>
>>diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
>>index e738f6206ea5..0497fdc37f90 100644
>>--- a/fs/btrfs/Makefile
>>+++ b/fs/btrfs/Makefile
>>@@ -16,6 +16,7 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
>>  btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o
>>  btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o
>>  btrfs-$(CONFIG_BTRFS_FS_REF_VERIFY) += ref-verify.o
>>+btrfs-$(CONFIG_BLK_DEV_ZONED) += zoned.o
>>  btrfs-$(CONFIG_BTRFS_FS_RUN_SANITY_TESTS) += tests/free-space-tests.o \
>>  	tests/extent-buffer-tests.o tests/btrfs-tests.o \
>>diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
>>index 20ce1970015f..6f6d77224c2b 100644
>>--- a/fs/btrfs/dev-replace.c
>>+++ b/fs/btrfs/dev-replace.c
>>@@ -21,6 +21,7 @@
>>  #include "rcu-string.h"
>>  #include "dev-replace.h"
>>  #include "sysfs.h"
>>+#include "zoned.h"
>>  /*
>>   * Device replace overview
>>@@ -291,6 +292,10 @@ static int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
>>  	set_blocksize(device->bdev, BTRFS_BDEV_BLOCKSIZE);
>>  	device->fs_devices = fs_info->fs_devices;
>>+	ret = btrfs_get_dev_zone_info(device);
>>+	if (ret)
>>+		goto error;
>>+
>>  	mutex_lock(&fs_info->fs_devices->device_list_mutex);
>>  	list_add(&device->dev_list, &fs_info->fs_devices->devices);
>>  	fs_info->fs_devices->num_devices++;
>>diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
>>index 8840a4fa81eb..ed55014fd1bd 100644
>>--- a/fs/btrfs/super.c
>>+++ b/fs/btrfs/super.c
>>@@ -2462,6 +2462,11 @@ static void __init btrfs_print_mod_info(void)
>>  #endif
>>  #ifdef CONFIG_BTRFS_FS_REF_VERIFY
>>  			", ref-verify=on"
>>+#endif
>>+#ifdef CONFIG_BLK_DEV_ZONED
>>+			", zoned=yes"
>>+#else
>>+			", zoned=no"
>>  #endif
>>  			;
>>  	pr_info("Btrfs loaded, crc32c=%s%s\n", crc32c_impl(), options);
>>diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
>>index 58b9c419a2b6..e787bf89f761 100644
>>--- a/fs/btrfs/volumes.c
>>+++ b/fs/btrfs/volumes.c
>>@@ -31,6 +31,7 @@
>>  #include "space-info.h"
>>  #include "block-group.h"
>>  #include "discard.h"
>>+#include "zoned.h"
>>  const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
>>  	[BTRFS_RAID_RAID10] = {
>>@@ -374,6 +375,7 @@ void btrfs_free_device(struct btrfs_device *device)
>>  	rcu_string_free(device->name);
>>  	extent_io_tree_release(&device->alloc_state);
>>  	bio_put(device->flush_bio);
>>+	btrfs_destroy_dev_zone_info(device);
>>  	kfree(device);
>>  }
>>@@ -667,6 +669,11 @@ static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices,
>>  	clear_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
>>  	device->mode = flags;
>>+	/* Get zone type information of zoned block devices */
>>+	ret = btrfs_get_dev_zone_info(device);
>>+	if (ret != 0)
>>+		goto error_free_page;
>>+
>>  	fs_devices->open_devices++;
>>  	if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) &&
>>  	    device->devid != BTRFS_DEV_REPLACE_DEVID) {
>>@@ -1143,6 +1150,7 @@ static void btrfs_close_one_device(struct btrfs_device *device)
>>  		device->bdev = NULL;
>>  	}
>>  	clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
>>+	btrfs_destroy_dev_zone_info(device);
>>  	device->fs_info = NULL;
>>  	atomic_set(&device->dev_stats_ccnt, 0);
>>@@ -2543,6 +2551,14 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
>>  	}
>>  	rcu_assign_pointer(device->name, name);
>>+	device->fs_info = fs_info;
>>+	device->bdev = bdev;
>>+
>>+	/* Get zone type information of zoned block devices */
>>+	ret = btrfs_get_dev_zone_info(device);
>>+	if (ret)
>>+		goto error_free_device;
>>+
>>  	trans = btrfs_start_transaction(root, 0);
>>  	if (IS_ERR(trans)) {
>>  		ret = PTR_ERR(trans);
>>@@ -2559,8 +2575,6 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
>>  					 fs_info->sectorsize);
>>  	device->disk_total_bytes = device->total_bytes;
>>  	device->commit_total_bytes = device->total_bytes;
>>-	device->fs_info = fs_info;
>>-	device->bdev = bdev;
>>  	set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
>>  	clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
>>  	device->mode = FMODE_EXCL;
>>@@ -2707,6 +2721,7 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
>>  		sb->s_flags |= SB_RDONLY;
>>  	if (trans)
>>  		btrfs_end_transaction(trans);
>>+	btrfs_destroy_dev_zone_info(device);
>>  error_free_device:
>>  	btrfs_free_device(device);
>>  error:
>>diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
>>index bf27ac07d315..9c07b97a2260 100644
>>--- a/fs/btrfs/volumes.h
>>+++ b/fs/btrfs/volumes.h
>>@@ -51,6 +51,8 @@ struct btrfs_io_geometry {
>>  #define BTRFS_DEV_STATE_REPLACE_TGT	(3)
>>  #define BTRFS_DEV_STATE_FLUSH_SENT	(4)
>>+struct btrfs_zoned_device_info;
>>+
>>  struct btrfs_device {
>>  	struct list_head dev_list; /* device_list_mutex */
>>  	struct list_head dev_alloc_list; /* chunk mutex */
>>@@ -64,6 +66,8 @@ struct btrfs_device {
>>  	struct block_device *bdev;
>>+	struct btrfs_zoned_device_info *zone_info;
>>+
>>  	/* the mode sent to blkdev_get */
>>  	fmode_t mode;
>>diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
>>new file mode 100644
>>index 000000000000..5657d654bc44
>>--- /dev/null
>>+++ b/fs/btrfs/zoned.c
>>@@ -0,0 +1,176 @@
>>+// SPDX-License-Identifier: GPL-2.0
>>+
>>+#include <linux/slab.h>
>>+#include <linux/blkdev.h>
>>+#include "ctree.h"
>>+#include "volumes.h"
>>+#include "zoned.h"
>>+#include "rcu-string.h"
>>+
>>+/* Maximum number of zones to report per blkdev_report_zones() call */
>>+#define BTRFS_REPORT_NR_ZONES   4096
>>+
>>+static int copy_zone_info_cb(struct blk_zone *zone, unsigned int idx,
>>+			     void *data)
>>+{
>>+	struct blk_zone *zones = data;
>>+
>>+	memcpy(&zones[idx], zone, sizeof(*zone));
>>+
>>+	return 0;
>>+}
>>+
>>+static int btrfs_get_dev_zones(struct btrfs_device *device, u64 pos,
>>+			       struct blk_zone *zones, unsigned int *nr_zones)
>>+{
>>+	int ret;
>>+
>>+	if (!*nr_zones)
>>+		return 0;
>>+
>>+	ret = blkdev_report_zones(device->bdev, pos >> SECTOR_SHIFT, *nr_zones,
>>+				  copy_zone_info_cb, zones);
>>+	if (ret < 0) {
>>+		btrfs_err_in_rcu(device->fs_info,
>>+				 "get zone at %llu on %s failed %d", pos,
>>+				 rcu_str_deref(device->name), ret);
>>+		return ret;
>>+	}
>>+	*nr_zones = ret;
>>+	if (!ret)
>>+		return -EIO;
>>+
>>+	return 0;
>>+}
>>+
>>+int btrfs_get_dev_zone_info(struct btrfs_device *device)
>>+{
>>+	struct btrfs_zoned_device_info *zone_info = NULL;
>>+	struct block_device *bdev = device->bdev;
>>+	sector_t nr_sectors = bdev->bd_part->nr_sects;
>>+	sector_t sector = 0;
>>+	struct blk_zone *zones = NULL;
>>+	unsigned int i, nreported = 0, nr_zones;
>>+	unsigned int zone_sectors;
>>+	int ret;
>>+	char devstr[sizeof(device->fs_info->sb->s_id) +
>>+		    sizeof(" (device )") - 1];
>>+
>>+	if (!bdev_is_zoned(bdev))
>>+		return 0;
>>+
>>+	if (device->zone_info)
>>+		return 0;
>>+
>>+	zone_info = kzalloc(sizeof(*zone_info), GFP_KERNEL);
>>+	if (!zone_info)
>>+		return -ENOMEM;
>>+
>>+	zone_sectors = bdev_zone_sectors(bdev);
>>+	ASSERT(is_power_of_2(zone_sectors));
>>+	zone_info->zone_size = (u64)zone_sectors << SECTOR_SHIFT;
>>+	zone_info->zone_size_shift = ilog2(zone_info->zone_size);
>>+	zone_info->nr_zones = nr_sectors >> ilog2(bdev_zone_sectors(bdev));
>>+	if (!IS_ALIGNED(nr_sectors, zone_sectors))
>>+		zone_info->nr_zones++;
>>+
>>+	zone_info->seq_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
>>+	if (!zone_info->seq_zones) {
>>+		ret = -ENOMEM;
>>+		goto out;
>>+	}
>>+
>>+	zone_info->empty_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
>>+	if (!zone_info->empty_zones) {
>>+		ret = -ENOMEM;
>>+		goto out;
>>+	}
>>+
>>+	zones = kcalloc(BTRFS_REPORT_NR_ZONES,
>>+			sizeof(struct blk_zone), GFP_KERNEL);
>>+	if (!zones) {
>>+		ret = -ENOMEM;
>>+		goto out;
>>+	}
>>+
>>+	/* Get zones type */
>>+	while (sector < nr_sectors) {
>>+		nr_zones = BTRFS_REPORT_NR_ZONES;
>>+		ret = btrfs_get_dev_zones(device, sector << SECTOR_SHIFT, zones,
>>+					  &nr_zones);
>>+		if (ret)
>>+			goto out;
>>+
>>+		for (i = 0; i < nr_zones; i++) {
>>+			if (zones[i].type == BLK_ZONE_TYPE_SEQWRITE_REQ)
>>+				set_bit(nreported, zone_info->seq_zones);
>>+			if (zones[i].cond == BLK_ZONE_COND_EMPTY)
>>+				set_bit(nreported, zone_info->empty_zones);
>>+			nreported++;
>>+		}
>>+		sector = zones[nr_zones - 1].start + zones[nr_zones - 1].len;
>>+	}
>>+
>>+	if (nreported != zone_info->nr_zones) {
>>+		btrfs_err_in_rcu(device->fs_info,
>>+				 "inconsistent number of zones on %s (%u / %u)",
>>+				 rcu_str_deref(device->name), nreported,
>>+				 zone_info->nr_zones);
>>+		ret = -EIO;
>>+		goto out;
>>+	}
>>+
>>+	kfree(zones);
>>+
>>+	device->zone_info = zone_info;
>>+
>>+	devstr[0] = 0;
>>+	if (device->fs_info)
>>+		snprintf(devstr, sizeof(devstr), " (device %s)",
>>+			 device->fs_info->sb->s_id);
>>+
>>+	rcu_read_lock();
>>+	pr_info(
>
>Why isn't this btrfs_info() ?  Thanks,

Because, we might not have device->fs_info set at this point. At the mount
time, this function is called under btrfs_open_devices() in
btrfs_mount_root(). OTOH, device->fs_info is set under open_ctree() which
is called later than btrfs_open_devices().

Using btrfs_info() here results in printing "BTRFS info (device <unknown>):
..." at the mount time, which is an annoying look in my opinion. So, I
followed the "scanned by ..." message style in device_list_add().

I'll add a description comment here.

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 12/41] btrfs: implement zoned chunk allocator
  2020-11-02 20:09     ` Josef Bacik
@ 2020-11-02 22:21       ` Naohiro Aota
  0 siblings, 0 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-11-02 22:21 UTC (permalink / raw)
  To: Josef Bacik; +Cc: linux-btrfs, dsterba, hare, linux-fsdevel

On Mon, Nov 02, 2020 at 03:09:58PM -0500, Josef Bacik wrote:
>On 10/30/20 9:51 AM, Naohiro Aota wrote:
>>This commit implements a zoned chunk/dev_extent allocator. The zoned
>>allocator aligns the device extents to zone boundaries, so that a zone
>>reset affects only the device extent and does not change the state of
>>blocks in the neighbor device extents.
>>
>>Also, it checks that a region allocation is not overlapping any of the
>>super block zones, and ensures the region is empty.
>>
>>Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
>>---
>>  fs/btrfs/volumes.c | 131 +++++++++++++++++++++++++++++++++++++++++++++
>>  fs/btrfs/volumes.h |   1 +
>>  fs/btrfs/zoned.c   | 126 +++++++++++++++++++++++++++++++++++++++++++
>>  fs/btrfs/zoned.h   |  30 +++++++++++
>>  4 files changed, 288 insertions(+)
>>
>>diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
>>index db884b96a5ea..78c62ef02e6f 100644
>>--- a/fs/btrfs/volumes.c
>>+++ b/fs/btrfs/volumes.c
>>@@ -1416,6 +1416,14 @@ static bool contains_pending_extent(struct btrfs_device *device, u64 *start,
>>  	return false;
>>  }
>>+static inline u64 dev_extent_search_start_zoned(struct btrfs_device *device,
>>+						u64 start)
>>+{
>>+	start = max_t(u64, start,
>>+		      max_t(u64, device->zone_info->zone_size, SZ_1M));
>>+	return btrfs_zone_align(device, start);
>>+}
>>+
>>  static u64 dev_extent_search_start(struct btrfs_device *device, u64 start)
>>  {
>>  	switch (device->fs_devices->chunk_alloc_policy) {
>>@@ -1426,11 +1434,57 @@ static u64 dev_extent_search_start(struct btrfs_device *device, u64 start)
>>  		 * make sure to start at an offset of at least 1MB.
>>  		 */
>>  		return max_t(u64, start, SZ_1M);
>>+	case BTRFS_CHUNK_ALLOC_ZONED:
>>+		return dev_extent_search_start_zoned(device, start);
>>  	default:
>>  		BUG();
>>  	}
>>  }
>>+static bool dev_extent_hole_check_zoned(struct btrfs_device *device,
>>+					u64 *hole_start, u64 *hole_size,
>>+					u64 num_bytes)
>>+{
>>+	u64 zone_size = device->zone_info->zone_size;
>>+	u64 pos;
>>+	int ret;
>>+	int changed = 0;
>>+
>>+	ASSERT(IS_ALIGNED(*hole_start, zone_size));
>>+
>>+	while (*hole_size > 0) {
>>+		pos = btrfs_find_allocatable_zones(device, *hole_start,
>>+						   *hole_start + *hole_size,
>>+						   num_bytes);
>>+		if (pos != *hole_start) {
>>+			*hole_size = *hole_start + *hole_size - pos;
>>+			*hole_start = pos;
>>+			changed = 1;
>>+			if (*hole_size < num_bytes)
>>+				break;
>>+		}
>>+
>>+		ret = btrfs_ensure_empty_zones(device, pos, num_bytes);
>>+
>>+		/* range is ensured to be empty */
>>+		if (!ret)
>>+			return changed;
>>+
>>+		/* given hole range was invalid (outside of device) */
>>+		if (ret == -ERANGE) {
>>+			*hole_start += *hole_size;
>>+			*hole_size = 0;
>>+			return 1;
>>+		}
>>+
>>+		*hole_start += zone_size;
>>+		*hole_size -= zone_size;
>>+		changed = 1;
>>+	}
>>+
>>+	return changed;
>>+}
>>+
>>  /**
>>   * dev_extent_hole_check - check if specified hole is suitable for allocation
>>   * @device:	the device which we have the hole
>>@@ -1463,6 +1517,10 @@ static bool dev_extent_hole_check(struct btrfs_device *device, u64 *hole_start,
>>  	case BTRFS_CHUNK_ALLOC_REGULAR:
>>  		/* No extra check */
>>  		break;
>>+	case BTRFS_CHUNK_ALLOC_ZONED:
>>+		changed |= dev_extent_hole_check_zoned(device, hole_start,
>>+						       hole_size, num_bytes);
>I'm confused here, we check to make sure the pending stuff doesn't 
>overlap with non-empty zones.  However we don't ever actually mark 
>zones as non-empty except on mount.  I realize that if we allocate 
>this zone then it appears pending and thus we won't allocate with this 
>zone again while the fs is mounted, but it took me a while to realize 
>this.  Is there a reason to not mark a zone as non-empty when we 
>allocate from it?

It's marking the zones as non-empty. Allocated zones eventually
construct a block group in btrfs_make_block_group(). The function calls
btrfs_load_block_group_zone_info() and that will clear the empty flag.

>
>
>>+		break;
>>  	default:
>>  		BUG();
>>  	}
>>@@ -1517,6 +1575,9 @@ static int find_free_dev_extent_start(struct btrfs_device *device,
>>  	search_start = dev_extent_search_start(device, search_start);
>>+	WARN_ON(device->zone_info &&
>>+		!IS_ALIGNED(num_bytes, device->zone_info->zone_size));
>>+
>>  	path = btrfs_alloc_path();
>>  	if (!path)
>>  		return -ENOMEM;
>>@@ -4907,6 +4968,37 @@ static void init_alloc_chunk_ctl_policy_regular(
>>  	ctl->dev_extent_min = BTRFS_STRIPE_LEN * ctl->dev_stripes;
>>  }
>>+static void
>>+init_alloc_chunk_ctl_policy_zoned(struct btrfs_fs_devices *fs_devices,
>>+				  struct alloc_chunk_ctl *ctl)
>>+{
>>+	u64 zone_size = fs_devices->fs_info->zone_size;
>>+	u64 limit;
>>+	int min_num_stripes = ctl->devs_min * ctl->dev_stripes;
>>+	int min_data_stripes = (min_num_stripes - ctl->nparity) / ctl->ncopies;
>>+	u64 min_chunk_size = min_data_stripes * zone_size;
>>+	u64 type = ctl->type;
>>+
>>+	ctl->max_stripe_size = zone_size;
>>+	if (type & BTRFS_BLOCK_GROUP_DATA) {
>>+		ctl->max_chunk_size = round_down(BTRFS_MAX_DATA_CHUNK_SIZE,
>>+						 zone_size);
>>+	} else if (type & BTRFS_BLOCK_GROUP_METADATA) {
>>+		ctl->max_chunk_size = ctl->max_stripe_size;
>>+	} else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
>>+		ctl->max_chunk_size = 2 * ctl->max_stripe_size;
>>+		ctl->devs_max = min_t(int, ctl->devs_max,
>>+				      BTRFS_MAX_DEVS_SYS_CHUNK);
>>+	}
>>+
>>+	/* We don't want a chunk larger than 10% of writable space */
>>+	limit = max(round_down(div_factor(fs_devices->total_rw_bytes, 1),
>>+			       zone_size),
>>+		    min_chunk_size);
>>+	ctl->max_chunk_size = min(limit, ctl->max_chunk_size);
>>+	ctl->dev_extent_min = zone_size * ctl->dev_stripes;
>>+}
>>+
>>  static void init_alloc_chunk_ctl(struct btrfs_fs_devices *fs_devices,
>>  				 struct alloc_chunk_ctl *ctl)
>>  {
>>@@ -4927,6 +5019,9 @@ static void init_alloc_chunk_ctl(struct btrfs_fs_devices *fs_devices,
>>  	case BTRFS_CHUNK_ALLOC_REGULAR:
>>  		init_alloc_chunk_ctl_policy_regular(fs_devices, ctl);
>>  		break;
>>+	case BTRFS_CHUNK_ALLOC_ZONED:
>>+		init_alloc_chunk_ctl_policy_zoned(fs_devices, ctl);
>>+		break;
>>  	default:
>>  		BUG();
>>  	}
>>@@ -5053,6 +5148,40 @@ static int decide_stripe_size_regular(struct alloc_chunk_ctl *ctl,
>>  	return 0;
>>  }
>>+static int decide_stripe_size_zoned(struct alloc_chunk_ctl *ctl,
>>+				    struct btrfs_device_info *devices_info)
>>+{
>>+	u64 zone_size = devices_info[0].dev->zone_info->zone_size;
>>+	/* number of stripes that count for block group size */
>>+	int data_stripes;
>>+
>>+	/*
>>+	 * It should hold because:
>>+	 *    dev_extent_min == dev_extent_want == zone_size * dev_stripes
>>+	 */
>>+	ASSERT(devices_info[ctl->ndevs - 1].max_avail == ctl->dev_extent_min);
>>+
>>+	ctl->stripe_size = zone_size;
>>+	ctl->num_stripes = ctl->ndevs * ctl->dev_stripes;
>>+	data_stripes = (ctl->num_stripes - ctl->nparity) / ctl->ncopies;
>>+
>>+	/*
>>+	 * stripe_size is fixed in ZONED. Reduce ndevs instead.
>>+	 */
>>+	if (ctl->stripe_size * data_stripes > ctl->max_chunk_size) {
>>+		ctl->ndevs = div_u64(div_u64(ctl->max_chunk_size * ctl->ncopies,
>>+					     ctl->stripe_size) + ctl->nparity,
>>+				     ctl->dev_stripes);
>>+		ctl->num_stripes = ctl->ndevs * ctl->dev_stripes;
>>+		data_stripes = (ctl->num_stripes - ctl->nparity) / ctl->ncopies;
>>+		ASSERT(ctl->stripe_size * data_stripes <= ctl->max_chunk_size);
>>+	}
>>+
>>+	ctl->chunk_size = ctl->stripe_size * data_stripes;
>>+
>>+	return 0;
>>+}
>>+
>>  static int decide_stripe_size(struct btrfs_fs_devices *fs_devices,
>>  			      struct alloc_chunk_ctl *ctl,
>>  			      struct btrfs_device_info *devices_info)
>>@@ -5080,6 +5209,8 @@ static int decide_stripe_size(struct btrfs_fs_devices *fs_devices,
>>  	switch (fs_devices->chunk_alloc_policy) {
>>  	case BTRFS_CHUNK_ALLOC_REGULAR:
>>  		return decide_stripe_size_regular(ctl, devices_info);
>>+	case BTRFS_CHUNK_ALLOC_ZONED:
>>+		return decide_stripe_size_zoned(ctl, devices_info);
>>  	default:
>>  		BUG();
>>  	}
>>diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
>>index 9c07b97a2260..0249aca668fb 100644
>>--- a/fs/btrfs/volumes.h
>>+++ b/fs/btrfs/volumes.h
>>@@ -213,6 +213,7 @@ BTRFS_DEVICE_GETSET_FUNCS(bytes_used);
>>  enum btrfs_chunk_allocation_policy {
>>  	BTRFS_CHUNK_ALLOC_REGULAR,
>>+	BTRFS_CHUNK_ALLOC_ZONED,
>>  };
>>  struct btrfs_fs_devices {
>>diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
>>index d5487cba203b..4411d786597a 100644
>>--- a/fs/btrfs/zoned.c
>>+++ b/fs/btrfs/zoned.c
>>@@ -1,11 +1,13 @@
>>  // SPDX-License-Identifier: GPL-2.0
>>+#include <linux/bitops.h>
>>  #include <linux/slab.h>
>>  #include <linux/blkdev.h>
>>  #include "ctree.h"
>>  #include "volumes.h"
>>  #include "zoned.h"
>>  #include "rcu-string.h"
>>+#include "disk-io.h"
>>  /* Maximum number of zones to report per blkdev_report_zones() call */
>>  #define BTRFS_REPORT_NR_ZONES   4096
>>@@ -328,6 +330,7 @@ int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
>>  	fs_info->zone_size = zone_size;
>>  	fs_info->max_zone_append_size = max_zone_append_size;
>>+	fs_info->fs_devices->chunk_alloc_policy = BTRFS_CHUNK_ALLOC_ZONED;
>>  	btrfs_info(fs_info, "ZONED mode enabled, zone size %llu B",
>>  		   fs_info->zone_size);
>>@@ -607,3 +610,126 @@ int btrfs_reset_sb_log_zones(struct block_device *bdev, int mirror)
>>  				sb_zone << zone_sectors_shift, zone_sectors * 2,
>>  				GFP_NOFS);
>>  }
>>+
>>+/*
>>+ * btrfs_check_allocatable_zones - find allocatable zones within give region
>>+ * @device:	the device to allocate a region
>>+ * @hole_start: the position of the hole to allocate the region
>>+ * @num_bytes:	the size of wanted region
>>+ * @hole_size:	the size of hole
>>+ *
>>+ * Allocatable region should not contain any superblock locations.
>>+ */
>>+u64 btrfs_find_allocatable_zones(struct btrfs_device *device, u64 hole_start,
>>+				 u64 hole_end, u64 num_bytes)
>>+{
>>+	struct btrfs_zoned_device_info *zinfo = device->zone_info;
>>+	u8 shift = zinfo->zone_size_shift;
>>+	u64 nzones = num_bytes >> shift;
>>+	u64 pos = hole_start;
>>+	u64 begin, end;
>>+	u64 sb_pos;
>>+	bool have_sb;
>>+	int i;
>>+
>>+	ASSERT(IS_ALIGNED(hole_start, zinfo->zone_size));
>>+	ASSERT(IS_ALIGNED(num_bytes, zinfo->zone_size));
>>+
>>+	while (pos < hole_end) {
>>+		begin = pos >> shift;
>>+		end = begin + nzones;
>>+
>>+		if (end > zinfo->nr_zones)
>>+			return hole_end;
>>+
>>+		/* check if zones in the region are all empty */
>>+		if (btrfs_dev_is_sequential(device, pos) &&
>>+		    find_next_zero_bit(zinfo->empty_zones, end, begin) != end) {
>>+			pos += zinfo->zone_size;
>>+			continue;
>>+		}
>>+
>>+		have_sb = false;
>>+		for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
>>+			sb_pos = sb_zone_number(zinfo->zone_size, i);
>>+			if (!(end < sb_pos || sb_pos + 1 < begin)) {
>>+				have_sb = true;
>>+				pos = (sb_pos + 2) << shift;
>>+				break;
>>+			}
>>+		}
>>+		if (!have_sb)
>>+			break;
>>+	}
>>+
>>+	return pos;
>>+}
>>+
>>+int btrfs_reset_device_zone(struct btrfs_device *device, u64 physical,
>>+			    u64 length, u64 *bytes)
>>+{
>>+	int ret;
>>+
>>+	*bytes = 0;
>>+	ret = blkdev_zone_mgmt(device->bdev, REQ_OP_ZONE_RESET,
>>+			       physical >> SECTOR_SHIFT, length >> SECTOR_SHIFT,
>>+			       GFP_NOFS);
>>+	if (ret)
>>+		return ret;
>>+
>>+	*bytes = length;
>>+	while (length) {
>>+		btrfs_dev_set_zone_empty(device, physical);
>>+		physical += device->zone_info->zone_size;
>>+		length -= device->zone_info->zone_size;
>>+	}
>>+
>>+	return 0;
>>+}
>>+
>>+int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size)
>>+{
>>+	struct btrfs_zoned_device_info *zinfo = device->zone_info;
>>+	u8 shift = zinfo->zone_size_shift;
>>+	unsigned long begin = start >> shift;
>>+	unsigned long end = (start + size) >> shift;
>>+	u64 pos;
>>+	int ret;
>>+
>>+	ASSERT(IS_ALIGNED(start, zinfo->zone_size));
>>+	ASSERT(IS_ALIGNED(size, zinfo->zone_size));
>>+
>>+	if (end > zinfo->nr_zones)
>>+		return -ERANGE;
>>+
>>+	/* all the zones are conventional */
>>+	if (find_next_bit(zinfo->seq_zones, begin, end) == end)
>>+		return 0;
>>+
>
>This check is duplicated below.
>

This one checks if bits from begin to end is all cleared (= all zones are
conventional). OTOH, the below checks if all the bits are set (= all zones
are sequential).

>>+	/* all the zones are sequential and empty */
>>+	if (find_next_zero_bit(zinfo->seq_zones, begin, end) == end &&
>>+	    find_next_zero_bit(zinfo->empty_zones, begin, end) == end)
>>+		return 0;
>>+
>>+	for (pos = start; pos < start + size; pos += zinfo->zone_size) {
>>+		u64 reset_bytes;
>>+
>>+		if (!btrfs_dev_is_sequential(device, pos) ||
>>+		    btrfs_dev_is_empty_zone(device, pos))
>>+			continue;
>>+
>>+		/* free regions should be empty */
>>+		btrfs_warn_in_rcu(
>>+			device->fs_info,
>>+			"resetting device %s zone %llu for allocation",
>>+			rcu_str_deref(device->name), pos >> shift);
>>+		WARN_ON_ONCE(1);
>>+
>>+		ret = btrfs_reset_device_zone(device, pos, zinfo->zone_size,
>>+					      &reset_bytes);
>>+		if (ret)
>>+			return ret;
>
>This seems bad, as we could just have corruption right?  So we're 
>resetting the zone which could lose us data right?  Shouldn't we just 
>bail here?  Thanks,
>
>Josef

Yes.. This happens 1) when we freed up the region but forget to reset the
zones, or 2) when we lost the allocation information. For the first case, it's
OK to reset the zones here. For the second case, it's still as much
dangerous as regular device since the regular btrfs will overwrite the
data in that case anyway. I admit it's much safer to bail out here, so I
can change this to error exiting.

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 14/41] btrfs: load zone's alloction offset
  2020-11-02 20:25     ` Josef Bacik
  2020-11-02 20:29       ` Josef Bacik
@ 2020-11-02 22:40       ` Naohiro Aota
  1 sibling, 0 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-11-02 22:40 UTC (permalink / raw)
  To: Josef Bacik; +Cc: linux-btrfs, dsterba, hare, linux-fsdevel

On Mon, Nov 02, 2020 at 03:25:42PM -0500, Josef Bacik wrote:
>On 10/30/20 9:51 AM, Naohiro Aota wrote:
>>Zoned btrfs must allocate blocks at the zones' write pointer. The device's
>>write pointer position can be mapped to a logical address within a block
>>group. This commit adds "alloc_offset" to track the logical address.
>>
>>This logical address is populated in btrfs_load_block-group_zone_info()
>
>btrfs_load_block_group_zone_info()
>

Fixed. Thanks.

>>from write pointers of corresponding zones.
>>
>>For now, zoned btrfs only support the SINGLE profile. Supporting non-SINGLE
>>profile with zone append writing is not trivial. For example, in the DUP
>>profile, we send a zone append writing IO to two zones on a device. The
>>device reply with written LBAs for the IOs. If the offsets of the returned
>>addresses from the beginning of the zone are different, then it results in
>>different logical addresses.
>>
>>We need fine-grained logical to physical mapping to support such separated
>>physical address issue. Since it should require additional metadata type,
>>disable non-SINGLE profiles for now.
>>
>>Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
>>---
>>  fs/btrfs/block-group.c |  15 ++++
>>  fs/btrfs/block-group.h |   6 ++
>>  fs/btrfs/zoned.c       | 153 +++++++++++++++++++++++++++++++++++++++++
>>  fs/btrfs/zoned.h       |   6 ++
>>  4 files changed, 180 insertions(+)
>>
>>diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
>>index e989c66aa764..920b2708c7f2 100644
>>--- a/fs/btrfs/block-group.c
>>+++ b/fs/btrfs/block-group.c
>>@@ -15,6 +15,7 @@
>>  #include "delalloc-space.h"
>>  #include "discard.h"
>>  #include "raid56.h"
>>+#include "zoned.h"
>>  /*
>>   * Return target flags in extended format or 0 if restripe for this chunk_type
>>@@ -1935,6 +1936,13 @@ static int read_one_block_group(struct btrfs_fs_info *info,
>>  			goto error;
>>  	}
>>+	ret = btrfs_load_block_group_zone_info(cache);
>>+	if (ret) {
>>+		btrfs_err(info, "failed to load zone info of bg %llu",
>>+			  cache->start);
>>+		goto error;
>>+	}
>>+
>>  	/*
>>  	 * We need to exclude the super stripes now so that the space info has
>>  	 * super bytes accounted for, otherwise we'll think we have more space
>>@@ -2161,6 +2169,13 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans, u64 bytes_used,
>>  	cache->last_byte_to_unpin = (u64)-1;
>>  	cache->cached = BTRFS_CACHE_FINISHED;
>>  	cache->needs_free_space = 1;
>>+
>>+	ret = btrfs_load_block_group_zone_info(cache);
>>+	if (ret) {
>>+		btrfs_put_block_group(cache);
>>+		return ret;
>>+	}
>>+
>>  	ret = exclude_super_stripes(cache);
>>  	if (ret) {
>>  		/* We may have excluded something, so call this just in case */
>>diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
>>index adfd7583a17b..14e3043c9ce7 100644
>>--- a/fs/btrfs/block-group.h
>>+++ b/fs/btrfs/block-group.h
>>@@ -183,6 +183,12 @@ struct btrfs_block_group {
>>  	/* Record locked full stripes for RAID5/6 block group */
>>  	struct btrfs_full_stripe_locks_tree full_stripe_locks_root;
>>+
>>+	/*
>>+	 * Allocation offset for the block group to implement sequential
>>+	 * allocation. This is used only with ZONED mode enabled.
>>+	 */
>>+	u64 alloc_offset;
>>  };
>>  static inline u64 btrfs_block_group_end(struct btrfs_block_group *block_group)
>>diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
>>index 4411d786597a..0aa821893a51 100644
>>--- a/fs/btrfs/zoned.c
>>+++ b/fs/btrfs/zoned.c
>>@@ -3,14 +3,20 @@
>>  #include <linux/bitops.h>
>>  #include <linux/slab.h>
>>  #include <linux/blkdev.h>
>>+#include <linux/sched/mm.h>
>>  #include "ctree.h"
>>  #include "volumes.h"
>>  #include "zoned.h"
>>  #include "rcu-string.h"
>>  #include "disk-io.h"
>>+#include "block-group.h"
>>  /* Maximum number of zones to report per blkdev_report_zones() call */
>>  #define BTRFS_REPORT_NR_ZONES   4096
>>+/* Invalid allocation pointer value for missing devices */
>>+#define WP_MISSING_DEV ((u64)-1)
>>+/* Pseudo write pointer value for conventional zone */
>>+#define WP_CONVENTIONAL ((u64)-2)
>>  static int copy_zone_info_cb(struct blk_zone *zone, unsigned int idx,
>>  			     void *data)
>>@@ -733,3 +739,150 @@ int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size)
>>  	return 0;
>>  }
>>+
>>+int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache)
>>+{
>>+	struct btrfs_fs_info *fs_info = cache->fs_info;
>>+	struct extent_map_tree *em_tree = &fs_info->mapping_tree;
>>+	struct extent_map *em;
>>+	struct map_lookup *map;
>>+	struct btrfs_device *device;
>>+	u64 logical = cache->start;
>>+	u64 length = cache->length;
>>+	u64 physical = 0;
>>+	int ret;
>>+	int i;
>>+	unsigned int nofs_flag;
>>+	u64 *alloc_offsets = NULL;
>>+	u32 num_sequential = 0, num_conventional = 0;
>>+
>>+	if (!btrfs_is_zoned(fs_info))
>>+		return 0;
>>+
>>+	/* Sanity check */
>>+	if (!IS_ALIGNED(length, fs_info->zone_size)) {
>>+		btrfs_err(fs_info, "unaligned block group at %llu + %llu",
>>+			  logical, length);
>>+		return -EIO;
>>+	}
>>+
>>+	/* Get the chunk mapping */
>>+	read_lock(&em_tree->lock);
>>+	em = lookup_extent_mapping(em_tree, logical, length);
>>+	read_unlock(&em_tree->lock);
>>+
>>+	if (!em)
>>+		return -EINVAL;
>>+
>>+	map = em->map_lookup;
>>+
>>+	/*
>>+	 * Get the zone type: if the group is mapped to a non-sequential zone,
>>+	 * there is no need for the allocation offset (fit allocation is OK).
>>+	 */
>>+	alloc_offsets = kcalloc(map->num_stripes, sizeof(*alloc_offsets),
>>+				GFP_NOFS);
>>+	if (!alloc_offsets) {
>>+		free_extent_map(em);
>>+		return -ENOMEM;
>>+	}
>>+
>>+	for (i = 0; i < map->num_stripes; i++) {
>>+		bool is_sequential;
>>+		struct blk_zone zone;
>>+
>>+		device = map->stripes[i].dev;
>>+		physical = map->stripes[i].physical;
>>+
>>+		if (device->bdev == NULL) {
>>+			alloc_offsets[i] = WP_MISSING_DEV;
>>+			continue;
>>+		}
>>+
>>+		is_sequential = btrfs_dev_is_sequential(device, physical);
>>+		if (is_sequential)
>>+			num_sequential++;
>>+		else
>>+			num_conventional++;
>>+
>>+		if (!is_sequential) {
>>+			alloc_offsets[i] = WP_CONVENTIONAL;
>>+			continue;
>>+		}
>>+
>>+		/*
>>+		 * This zone will be used for allocation, so mark this
>>+		 * zone non-empty.
>>+		 */
>>+		btrfs_dev_clear_zone_empty(device, physical);
>>+
>>+		/*
>>+		 * The group is mapped to a sequential zone. Get the zone write
>>+		 * pointer to determine the allocation offset within the zone.
>>+		 */
>>+		WARN_ON(!IS_ALIGNED(physical, fs_info->zone_size));
>>+		nofs_flag = memalloc_nofs_save();
>>+		ret = btrfs_get_dev_zone(device, physical, &zone);
>>+		memalloc_nofs_restore(nofs_flag);
>>+		if (ret == -EIO || ret == -EOPNOTSUPP) {
>>+			ret = 0;
>>+			alloc_offsets[i] = WP_MISSING_DEV;
>>+			continue;
>>+		} else if (ret) {
>>+			goto out;
>>+		}
>>+
>>+		switch (zone.cond) {
>>+		case BLK_ZONE_COND_OFFLINE:
>>+		case BLK_ZONE_COND_READONLY:
>>+			btrfs_err(fs_info, "Offline/readonly zone %llu",
>>+				  physical >> device->zone_info->zone_size_shift);
>>+			alloc_offsets[i] = WP_MISSING_DEV;
>>+			break;
>>+		case BLK_ZONE_COND_EMPTY:
>>+			alloc_offsets[i] = 0;
>>+			break;
>>+		case BLK_ZONE_COND_FULL:
>>+			alloc_offsets[i] = fs_info->zone_size;
>>+			break;
>>+		default:
>>+			/* Partially used zone */
>>+			alloc_offsets[i] =
>>+				((zone.wp - zone.start) << SECTOR_SHIFT);
>>+			break;
>>+		}
>>+	}
>>+
>>+	if (num_conventional > 0) {
>>+		/*
>>+		 * Since conventional zones does not have write pointer, we
>>+		 * cannot determine alloc_offset from the pointer
>>+		 */
>>+		ret = -EINVAL;
>>+		goto out;
>>+	}
>
>Does this mean we can't have zoned with a device that has conventional 
>and sequential zones?  I thought such things existed currently?  
>Thanks,
>
>Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 14/41] btrfs: load zone's alloction offset
  2020-11-02 20:29       ` Josef Bacik
@ 2020-11-02 22:43         ` Naohiro Aota
  0 siblings, 0 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-11-02 22:43 UTC (permalink / raw)
  To: Josef Bacik; +Cc: linux-btrfs, dsterba, hare, linux-fsdevel

On Mon, Nov 02, 2020 at 03:29:36PM -0500, Josef Bacik wrote:
>On 11/2/20 3:25 PM, Josef Bacik wrote:
>>On 10/30/20 9:51 AM, Naohiro Aota wrote:
>>>Zoned btrfs must allocate blocks at the zones' write pointer. The device's
>>>write pointer position can be mapped to a logical address within a block
>>>group. This commit adds "alloc_offset" to track the logical address.
>>>
>>>This logical address is populated in btrfs_load_block-group_zone_info()
>>
>>btrfs_load_block_group_zone_info()
>>
>>>from write pointers of corresponding zones.
>>>
>>>For now, zoned btrfs only support the SINGLE profile. Supporting non-SINGLE
>>>profile with zone append writing is not trivial. For example, in the DUP
>>>profile, we send a zone append writing IO to two zones on a device. The
>>>device reply with written LBAs for the IOs. If the offsets of the returned
>>>addresses from the beginning of the zone are different, then it results in
>>>different logical addresses.
>>>
>>>We need fine-grained logical to physical mapping to support such separated
>>>physical address issue. Since it should require additional metadata type,
>>>disable non-SINGLE profiles for now.
>>>
>>>Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
>>>---
>>>  fs/btrfs/block-group.c |  15 ++++
>>>  fs/btrfs/block-group.h |   6 ++
>>>  fs/btrfs/zoned.c       | 153 +++++++++++++++++++++++++++++++++++++++++
>>>  fs/btrfs/zoned.h       |   6 ++
>>>  4 files changed, 180 insertions(+)
>>>
>>>diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
>>>index e989c66aa764..920b2708c7f2 100644
>>>--- a/fs/btrfs/block-group.c
>>>+++ b/fs/btrfs/block-group.c
>>>@@ -15,6 +15,7 @@
>>>  #include "delalloc-space.h"
>>>  #include "discard.h"
>>>  #include "raid56.h"
>>>+#include "zoned.h"
>>>  /*
>>>   * Return target flags in extended format or 0 if restripe for this chunk_type
>>>@@ -1935,6 +1936,13 @@ static int read_one_block_group(struct 
>>>btrfs_fs_info *info,
>>>              goto error;
>>>      }
>>>+    ret = btrfs_load_block_group_zone_info(cache);
>>>+    if (ret) {
>>>+        btrfs_err(info, "failed to load zone info of bg %llu",
>>>+              cache->start);
>>>+        goto error;
>>>+    }
>>>+
>>>      /*
>>>       * We need to exclude the super stripes now so that the space info has
>>>       * super bytes accounted for, otherwise we'll think we have more space
>>>@@ -2161,6 +2169,13 @@ int btrfs_make_block_group(struct 
>>>btrfs_trans_handle *trans, u64 bytes_used,
>>>      cache->last_byte_to_unpin = (u64)-1;
>>>      cache->cached = BTRFS_CACHE_FINISHED;
>>>      cache->needs_free_space = 1;
>>>+
>>>+    ret = btrfs_load_block_group_zone_info(cache);
>>>+    if (ret) {
>>>+        btrfs_put_block_group(cache);
>>>+        return ret;
>>>+    }
>>>+
>>>      ret = exclude_super_stripes(cache);
>>>      if (ret) {
>>>          /* We may have excluded something, so call this just in case */
>>>diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
>>>index adfd7583a17b..14e3043c9ce7 100644
>>>--- a/fs/btrfs/block-group.h
>>>+++ b/fs/btrfs/block-group.h
>>>@@ -183,6 +183,12 @@ struct btrfs_block_group {
>>>      /* Record locked full stripes for RAID5/6 block group */
>>>      struct btrfs_full_stripe_locks_tree full_stripe_locks_root;
>>>+
>>>+    /*
>>>+     * Allocation offset for the block group to implement sequential
>>>+     * allocation. This is used only with ZONED mode enabled.
>>>+     */
>>>+    u64 alloc_offset;
>>>  };
>>>  static inline u64 btrfs_block_group_end(struct btrfs_block_group *block_group)
>>>diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
>>>index 4411d786597a..0aa821893a51 100644
>>>--- a/fs/btrfs/zoned.c
>>>+++ b/fs/btrfs/zoned.c
>>>@@ -3,14 +3,20 @@
>>>  #include <linux/bitops.h>
>>>  #include <linux/slab.h>
>>>  #include <linux/blkdev.h>
>>>+#include <linux/sched/mm.h>
>>>  #include "ctree.h"
>>>  #include "volumes.h"
>>>  #include "zoned.h"
>>>  #include "rcu-string.h"
>>>  #include "disk-io.h"
>>>+#include "block-group.h"
>>>  /* Maximum number of zones to report per blkdev_report_zones() call */
>>>  #define BTRFS_REPORT_NR_ZONES   4096
>>>+/* Invalid allocation pointer value for missing devices */
>>>+#define WP_MISSING_DEV ((u64)-1)
>>>+/* Pseudo write pointer value for conventional zone */
>>>+#define WP_CONVENTIONAL ((u64)-2)
>>>  static int copy_zone_info_cb(struct blk_zone *zone, unsigned int idx,
>>>                   void *data)
>>>@@ -733,3 +739,150 @@ int btrfs_ensure_empty_zones(struct 
>>>btrfs_device *device, u64 start, u64 size)
>>>      return 0;
>>>  }
>>>+
>>>+int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache)
>>>+{
>>>+    struct btrfs_fs_info *fs_info = cache->fs_info;
>>>+    struct extent_map_tree *em_tree = &fs_info->mapping_tree;
>>>+    struct extent_map *em;
>>>+    struct map_lookup *map;
>>>+    struct btrfs_device *device;
>>>+    u64 logical = cache->start;
>>>+    u64 length = cache->length;
>>>+    u64 physical = 0;
>>>+    int ret;
>>>+    int i;
>>>+    unsigned int nofs_flag;
>>>+    u64 *alloc_offsets = NULL;
>>>+    u32 num_sequential = 0, num_conventional = 0;
>>>+
>>>+    if (!btrfs_is_zoned(fs_info))
>>>+        return 0;
>>>+
>>>+    /* Sanity check */
>>>+    if (!IS_ALIGNED(length, fs_info->zone_size)) {
>>>+        btrfs_err(fs_info, "unaligned block group at %llu + %llu",
>>>+              logical, length);
>>>+        return -EIO;
>>>+    }
>>>+
>>>+    /* Get the chunk mapping */
>>>+    read_lock(&em_tree->lock);
>>>+    em = lookup_extent_mapping(em_tree, logical, length);
>>>+    read_unlock(&em_tree->lock);
>>>+
>>>+    if (!em)
>>>+        return -EINVAL;
>>>+
>>>+    map = em->map_lookup;
>>>+
>>>+    /*
>>>+     * Get the zone type: if the group is mapped to a non-sequential zone,
>>>+     * there is no need for the allocation offset (fit allocation is OK).
>>>+     */
>>>+    alloc_offsets = kcalloc(map->num_stripes, sizeof(*alloc_offsets),
>>>+                GFP_NOFS);
>>>+    if (!alloc_offsets) {
>>>+        free_extent_map(em);
>>>+        return -ENOMEM;
>>>+    }
>>>+
>>>+    for (i = 0; i < map->num_stripes; i++) {
>>>+        bool is_sequential;
>>>+        struct blk_zone zone;
>>>+
>>>+        device = map->stripes[i].dev;
>>>+        physical = map->stripes[i].physical;
>>>+
>>>+        if (device->bdev == NULL) {
>>>+            alloc_offsets[i] = WP_MISSING_DEV;
>>>+            continue;
>>>+        }
>>>+
>>>+        is_sequential = btrfs_dev_is_sequential(device, physical);
>>>+        if (is_sequential)
>>>+            num_sequential++;
>>>+        else
>>>+            num_conventional++;
>>>+
>>>+        if (!is_sequential) {
>>>+            alloc_offsets[i] = WP_CONVENTIONAL;
>>>+            continue;
>>>+        }
>>>+
>>>+        /*
>>>+         * This zone will be used for allocation, so mark this
>>>+         * zone non-empty.
>>>+         */
>>>+        btrfs_dev_clear_zone_empty(device, physical);
>>>+
>>>+        /*
>>>+         * The group is mapped to a sequential zone. Get the zone write
>>>+         * pointer to determine the allocation offset within the zone.
>>>+         */
>>>+        WARN_ON(!IS_ALIGNED(physical, fs_info->zone_size));
>>>+        nofs_flag = memalloc_nofs_save();
>>>+        ret = btrfs_get_dev_zone(device, physical, &zone);
>>>+        memalloc_nofs_restore(nofs_flag);
>>>+        if (ret == -EIO || ret == -EOPNOTSUPP) {
>>>+            ret = 0;
>>>+            alloc_offsets[i] = WP_MISSING_DEV;
>>>+            continue;
>>>+        } else if (ret) {
>>>+            goto out;
>>>+        }
>>>+
>>>+        switch (zone.cond) {
>>>+        case BLK_ZONE_COND_OFFLINE:
>>>+        case BLK_ZONE_COND_READONLY:
>>>+            btrfs_err(fs_info, "Offline/readonly zone %llu",
>>>+                  physical >> device->zone_info->zone_size_shift);
>>>+            alloc_offsets[i] = WP_MISSING_DEV;
>>>+            break;
>>>+        case BLK_ZONE_COND_EMPTY:
>>>+            alloc_offsets[i] = 0;
>>>+            break;
>>>+        case BLK_ZONE_COND_FULL:
>>>+            alloc_offsets[i] = fs_info->zone_size;
>>>+            break;
>>>+        default:
>>>+            /* Partially used zone */
>>>+            alloc_offsets[i] =
>>>+                ((zone.wp - zone.start) << SECTOR_SHIFT);
>>>+            break;
>>>+        }
>>>+    }
>>>+
>>>+    if (num_conventional > 0) {
>>>+        /*
>>>+         * Since conventional zones does not have write pointer, we
>>>+         * cannot determine alloc_offset from the pointer
>>>+         */
>>>+        ret = -EINVAL;
>>>+        goto out;
>>>+    }
>>
>>Does this mean we can't have zoned with a device that has 
>>conventional and sequential zones?  I thought such things existed 
>>currently?  Thanks,
>
>I see this changes in a follow up patch, ignore me, you can add
>
>Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks. I have added a comment mentioning that the next patch will handle
the case, just in case.

>
>Thanks,
>
>Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 15/41] btrfs: emulate write pointer for conventional zones
  2020-11-02 20:37     ` Josef Bacik
@ 2020-11-03  1:25       ` Naohiro Aota
  0 siblings, 0 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-11-03  1:25 UTC (permalink / raw)
  To: Josef Bacik; +Cc: linux-btrfs, dsterba, hare, linux-fsdevel

On Mon, Nov 02, 2020 at 03:37:35PM -0500, Josef Bacik wrote:
>On 10/30/20 9:51 AM, Naohiro Aota wrote:
>>Conventional zones do not have a write pointer, so we cannot use it to
>>determine the allocation offset if a block group contains a conventional
>>zone.
>>
>>But instead, we can consider the end of the last allocated extent in the
>>block group as an allocation offset.
>>
>>Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
>>---
>>  fs/btrfs/zoned.c | 119 ++++++++++++++++++++++++++++++++++++++++++++---
>>  1 file changed, 113 insertions(+), 6 deletions(-)
>>
>>diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
>>index 0aa821893a51..8f58d0853cc3 100644
>>--- a/fs/btrfs/zoned.c
>>+++ b/fs/btrfs/zoned.c
>>@@ -740,6 +740,104 @@ int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size)
>>  	return 0;
>>  }
>>+static int emulate_write_pointer(struct btrfs_block_group *cache,
>>+				 u64 *offset_ret)
>>+{
>>+	struct btrfs_fs_info *fs_info = cache->fs_info;
>>+	struct btrfs_root *root = fs_info->extent_root;
>>+	struct btrfs_path *path;
>>+	struct extent_buffer *leaf;
>>+	struct btrfs_key search_key;
>>+	struct btrfs_key found_key;
>>+	int slot;
>>+	int ret;
>>+	u64 length;
>>+
>>+	path = btrfs_alloc_path();
>>+	if (!path)
>>+		return -ENOMEM;
>>+
>>+	search_key.objectid = cache->start + cache->length;
>>+	search_key.type = 0;
>>+	search_key.offset = 0;
>>+
>
>You can just use 'key', don't have to use 'search_key'.

Fixed.

>
>Also you don't check for things like BTRFS_TREE_BLOCK_REF_KEY or 
>whatever in the case that we don't have an inline extent ref, so this 
>could error out with a fs with lots of snapshots and different 
>references.  What you need is to search back until you hit an 
>BTRFS_METADATA_ITEM_KEY or a BTRFS_EXTENT_ITEM_KEY, and then check the 
>offset of that thing.  Otherwise this will screw up.  Thanks,
>
>Josef

I overlooked that case. And, I just noticed we can use
btrfs_previous_extent_item() here. It looks much simpler now. Thanks.

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 11/41] btrfs: implement log-structured superblock for ZONED mode
  2020-11-02 18:54     ` Josef Bacik
@ 2020-11-03  3:31       ` Naohiro Aota
  0 siblings, 0 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-11-03  3:31 UTC (permalink / raw)
  To: Josef Bacik; +Cc: linux-btrfs, dsterba, hare, linux-fsdevel

On Mon, Nov 02, 2020 at 01:54:14PM -0500, Josef Bacik wrote:
>On 10/30/20 9:51 AM, Naohiro Aota wrote:
>>Superblock (and its copies) is the only data structure in btrfs which has a
>>fixed location on a device. Since we cannot overwrite in a sequential write
>>required zone, we cannot place superblock in the zone. One easy solution is
>>limiting superblock and copies to be placed only in conventional zones.
>>However, this method has two downsides: one is reduced number of superblock
>>copies. The location of the second copy of superblock is 256GB, which is in
>>a sequential write required zone on typical devices in the market today.
>>So, the number of superblock and copies is limited to be two.  Second
>>downside is that we cannot support devices which have no conventional zones
>>at all.
>>
>>To solve these two problems, we employ superblock log writing. It uses two
>>zones as a circular buffer to write updated superblocks. Once the first
>>zone is filled up, start writing into the second buffer. Then, when the
>>both zones are filled up and before start writing to the first zone again,
>>it reset the first zone.
>>
>>We can determine the position of the latest superblock by reading write
>>pointer information from a device. One corner case is when the both zones
>>are full. For this situation, we read out the last superblock of each
>>zone, and compare them to determine which zone is older.
>>
>>The following zones are reserved as the circular buffer on ZONED btrfs.
>>
>>- The primary superblock: zones 0 and 1
>>- The first copy: zones 16 and 17
>>- The second copy: zones 1024 or zone at 256GB which is minimum, and next
>>   to it
>>
>>If these reserved zones are conventional, superblock is written fixed at
>>the start of the zone without logging.
>>
>
><snip>
>
>>  /*
>>   * This is only the first step towards a full-features scrub. It reads all
>>@@ -3704,6 +3705,8 @@ static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
>>  		if (bytenr + BTRFS_SUPER_INFO_SIZE >
>>  		    scrub_dev->commit_total_bytes)
>>  			break;
>>+		if (!btrfs_check_super_location(scrub_dev, bytenr))
>>+			continue;
>
>Any reason in particular we're skipping scrubbing supers here?  Can't 
>we just lookup the bytenr and do the right thing here?

Hmm, technically, we can do something here, but I'm not sure it's useful to
scrub superblocks for zoned devices where superblocks are log-structured.
We can read and check if the latest superblock in the log is valid. But,
when we find it's not correct, we cannot overwrite it anyway. Instead, we
can append a new superblock to the log. But this is no different than
normal sync... Furthermore, the scrub-checked superblock might already be
out-dated at the time of reading.

We might want to read and check each entry of the log. And warn the user
when a superblock is corrupted. It's totally different from current
scrub_supers(), so we will need another helper function for it.

>
>>  		ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
>>  				  scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
>>diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
>>index 10827892c086..db884b96a5ea 100644
>>--- a/fs/btrfs/volumes.c
>>+++ b/fs/btrfs/volumes.c
>>@@ -1282,7 +1282,8 @@ void btrfs_release_disk_super(struct btrfs_super_block *super)
>>  }
>>  static struct btrfs_super_block *btrfs_read_disk_super(struct block_device *bdev,
>>-						       u64 bytenr)
>>+						       u64 bytenr,
>>+						       u64 bytenr_orig)
>>  {
>>  	struct btrfs_super_block *disk_super;
>>  	struct page *page;
>>@@ -1313,7 +1314,7 @@ static struct btrfs_super_block *btrfs_read_disk_super(struct block_device *bdev
>>  	/* align our pointer to the offset of the super block */
>>  	disk_super = p + offset_in_page(bytenr);
>>-	if (btrfs_super_bytenr(disk_super) != bytenr ||
>>+	if (btrfs_super_bytenr(disk_super) != bytenr_orig ||
>>  	    btrfs_super_magic(disk_super) != BTRFS_MAGIC) {
>>  		btrfs_release_disk_super(p);
>>  		return ERR_PTR(-EINVAL);
>>@@ -1348,7 +1349,8 @@ struct btrfs_device *btrfs_scan_one_device(const char *path, fmode_t flags,
>>  	bool new_device_added = false;
>>  	struct btrfs_device *device = NULL;
>>  	struct block_device *bdev;
>>-	u64 bytenr;
>>+	u64 bytenr, bytenr_orig;
>>+	int ret;
>>  	lockdep_assert_held(&uuid_mutex);
>>@@ -1358,14 +1360,18 @@ struct btrfs_device *btrfs_scan_one_device(const char *path, fmode_t flags,
>>  	 * So, we need to add a special mount option to scan for
>>  	 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
>>  	 */
>>-	bytenr = btrfs_sb_offset(0);
>>  	flags |= FMODE_EXCL;
>>  	bdev = blkdev_get_by_path(path, flags, holder);
>>  	if (IS_ERR(bdev))
>>  		return ERR_CAST(bdev);
>>-	disk_super = btrfs_read_disk_super(bdev, bytenr);
>>+	bytenr_orig = btrfs_sb_offset(0);
>>+	ret = btrfs_sb_log_location_bdev(bdev, 0, READ, &bytenr);
>>+	if (ret)
>>+		return ERR_PTR(ret);
>>+
>>+	disk_super = btrfs_read_disk_super(bdev, bytenr, bytenr_orig);
>>  	if (IS_ERR(disk_super)) {
>>  		device = ERR_CAST(disk_super);
>>  		goto error_bdev_put;
>>@@ -2029,6 +2035,11 @@ void btrfs_scratch_superblocks(struct btrfs_fs_info *fs_info,
>>  		if (IS_ERR(disk_super))
>>  			continue;
>>+		if (bdev_is_zoned(bdev)) {
>>+			btrfs_reset_sb_log_zones(bdev, copy_num);
>>+			continue;
>>+		}
>>+
>>  		memset(&disk_super->magic, 0, sizeof(disk_super->magic));
>>  		page = virt_to_page(disk_super);
>>diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
>>index ae509699da14..d5487cba203b 100644
>>--- a/fs/btrfs/zoned.c
>>+++ b/fs/btrfs/zoned.c
>>@@ -20,6 +20,25 @@ static int copy_zone_info_cb(struct blk_zone *zone, unsigned int idx,
>>  	return 0;
>>  }
>>+static int sb_write_pointer(struct block_device *bdev, struct blk_zone *zone,
>>+			    u64 *wp_ret);
>>+
>>+static inline u32 sb_zone_number(u8 shift, int mirror)
>>+{
>>+	ASSERT(mirror < BTRFS_SUPER_MIRROR_MAX);
>>+
>>+	switch (mirror) {
>>+	case 0:
>>+		return 0;
>>+	case 1:
>>+		return 16;
>>+	case 2:
>>+		return min(btrfs_sb_offset(mirror) >> shift, 1024ULL);
>>+	}
>>+
>
>Can we get a comment here explaining the zone numbers?

Sure. I'll add one.

>
>>+	return 0;
>>+}
>>+
>>  static int btrfs_get_dev_zones(struct btrfs_device *device, u64 pos,
>>  			       struct blk_zone *zones, unsigned int *nr_zones)
>>  {
>>@@ -123,6 +142,49 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device)
>>  		goto out;
>>  	}
>>+	/* validate superblock log */
>>+	nr_zones = 2;
>>+	for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
>>+		u32 sb_zone = sb_zone_number(zone_info->zone_size_shift, i);
>>+		u64 sb_wp;
>>+
>
>I'd rather see
>
>#define BTRFS_NR_ZONED_SB_ZONES 2
>
>or something equally poorly named and use that instead of our magic 2 everywhere.
>
>Then you can just do
>
>int index = i * BTRFS_NR_ZONED_SB_ZONES;
>&zone_info->sb_zones[index];

I'll do so. BTRFS_NR_ZONED_SB_ZONES is duplicating "ZONE", so how about
BTRFS_NR_SB_LOG_ZONES ?


>
><snip>
>
>>+static int sb_log_location(struct block_device *bdev, struct blk_zone *zones,
>>+			   int rw, u64 *bytenr_ret)
>>+{
>>+	u64 wp;
>>+	int ret;
>>+
>>+	if (zones[0].type == BLK_ZONE_TYPE_CONVENTIONAL) {
>>+		*bytenr_ret = zones[0].start << SECTOR_SHIFT;
>>+		return 0;
>>+	}
>>+
>>+	ret = sb_write_pointer(bdev, zones, &wp);
>>+	if (ret != -ENOENT && ret < 0)
>>+		return ret;
>>+
>>+	if (rw == WRITE) {
>>+		struct blk_zone *reset = NULL;
>>+
>>+		if (wp == zones[0].start << SECTOR_SHIFT)
>>+			reset = &zones[0];
>>+		else if (wp == zones[1].start << SECTOR_SHIFT)
>>+			reset = &zones[1];
>>+
>>+		if (reset && reset->cond != BLK_ZONE_COND_EMPTY) {
>>+			ASSERT(reset->cond == BLK_ZONE_COND_FULL);
>>+
>>+			ret = blkdev_zone_mgmt(bdev, REQ_OP_ZONE_RESET,
>>+					       reset->start, reset->len,
>>+					       GFP_NOFS);
>
>What happens if we crash right after this?  Is the WP set to the start 
>of the zone here?  Does this mean we'll simply miss the super block?  
>I understand we're resetting one zone here, but we're doing this in 
>order, so we'll reset one and write one, then reset the other and 
>write the next.  We don't wait until we've issued the writes for 
>everything, so it appears to me that there's a gap where we could have 
>the WP pointed at the start of the zone, which we view as an invalid 
>state and thus won't be able to mount the file system.  Or am I 
>missing something?  Thanks,

Here, we reset a zone we're going to write which contains the older
superblocks. And in this case, we should have the other zone fully written.
So, even after a reset and a crash, we still have the latest superblock in
the other zone.

>
>Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 11/41] btrfs: implement log-structured superblock for ZONED mode
  2020-11-02 18:22     ` Josef Bacik
  2020-11-02 18:53       ` Johannes Thumshirn
@ 2020-11-03  8:21       ` Naohiro Aota
  1 sibling, 0 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-11-03  8:21 UTC (permalink / raw)
  To: Josef Bacik; +Cc: linux-btrfs, dsterba, hare, linux-fsdevel

On Mon, Nov 02, 2020 at 01:22:56PM -0500, Josef Bacik wrote:
>On 10/30/20 9:51 AM, Naohiro Aota wrote:
>>Superblock (and its copies) is the only data structure in btrfs which has a
>>fixed location on a device. Since we cannot overwrite in a sequential write
>>required zone, we cannot place superblock in the zone. One easy solution is
>>limiting superblock and copies to be placed only in conventional zones.
>>However, this method has two downsides: one is reduced number of superblock
>>copies. The location of the second copy of superblock is 256GB, which is in
>>a sequential write required zone on typical devices in the market today.
>>So, the number of superblock and copies is limited to be two.  Second
>>downside is that we cannot support devices which have no conventional zones
>>at all.
>>
>>To solve these two problems, we employ superblock log writing. It uses two
>>zones as a circular buffer to write updated superblocks. Once the first
>>zone is filled up, start writing into the second buffer. Then, when the
>>both zones are filled up and before start writing to the first zone again,
>>it reset the first zone.
>>
>>We can determine the position of the latest superblock by reading write
>>pointer information from a device. One corner case is when the both zones
>>are full. For this situation, we read out the last superblock of each
>>zone, and compare them to determine which zone is older.
>>
>>The following zones are reserved as the circular buffer on ZONED btrfs.
>>
>>- The primary superblock: zones 0 and 1
>>- The first copy: zones 16 and 17
>>- The second copy: zones 1024 or zone at 256GB which is minimum, and next
>>   to it
>>
>>If these reserved zones are conventional, superblock is written fixed at
>>the start of the zone without logging.
>>
>>Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
>>---
>>  fs/btrfs/block-group.c |   9 ++
>>  fs/btrfs/disk-io.c     |  41 +++++-
>>  fs/btrfs/scrub.c       |   3 +
>>  fs/btrfs/volumes.c     |  21 ++-
>>  fs/btrfs/zoned.c       | 311 +++++++++++++++++++++++++++++++++++++++++
>>  fs/btrfs/zoned.h       |  40 ++++++
>>  6 files changed, 413 insertions(+), 12 deletions(-)
>>
>>diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
>>index c0f1d6818df7..e989c66aa764 100644
>>--- a/fs/btrfs/block-group.c
>>+++ b/fs/btrfs/block-group.c
>>@@ -1723,6 +1723,7 @@ int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
>>  static int exclude_super_stripes(struct btrfs_block_group *cache)
>>  {
>>  	struct btrfs_fs_info *fs_info = cache->fs_info;
>>+	bool zoned = btrfs_is_zoned(fs_info);
>>  	u64 bytenr;
>>  	u64 *logical;
>>  	int stripe_len;
>>@@ -1744,6 +1745,14 @@ static int exclude_super_stripes(struct btrfs_block_group *cache)
>>  		if (ret)
>>  			return ret;
>>+		/* shouldn't have super stripes in sequential zones */
>>+		if (zoned && nr) {
>>+			btrfs_err(fs_info,
>>+				  "Zoned btrfs's block group %llu should not have super blocks",
>>+				  cache->start);
>>+			return -EUCLEAN;
>>+		}
>>+
>
>I'm very confused about this check, namely how you've been able to 
>test without it blowing up, which makes me feel like I'm missing 
>something.
>
>We _always_ call exclude_super_stripes(), and we're simply looking up 
>the bytenr for that block, which appears to not do anything special 
>for zoned.  This should be looking up and failing whenever it looks 
>for super stripes far enough out. How are you not failing here 
>everytime you mount the fs?  Thanks,
>
>Josef

As previous discussion with David, we decided to exclude superblock
position of regular btrfs being allocated for zoned block groups, because
superblock is one of on-disk specification. (Sorry, I could not find a
pointer of the discussion) We also need to ensure some user data which
looks like a superblock won't corrupt the FS.

btrfs_find_allocatable_zones() is doing that exclusion ... this was my
understanding. But, to be precise, the function is just excluding
superblock log zones, not regular superblock positions.

However, it accidentally excludes superblock positions of regualr device.
We have superblocks on 16KB, 64MB and 256GB. And, we exclude zones 0, 1,
16, 17 and min(zones at 256GB, 1024). With typical 256MB zone size setup,
16KB and 64MB drop on zone 0, and 256GB on zone 1024. So, I was not hitting
this "if" on my test runs.

I'll fix btrfs_find_allocatable_zones() so that it also excludes regular
superblock positions.

Thanks,

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 00/41] btrfs: zoned block device support
  2020-10-30 13:51 [PATCH v9 00/41] btrfs: zoned block device support Naohiro Aota
  2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
@ 2020-11-03 11:54 ` David Sterba
  1 sibling, 0 replies; 119+ messages in thread
From: David Sterba @ 2020-11-03 11:54 UTC (permalink / raw)
  To: Naohiro Aota; +Cc: linux-btrfs, dsterba, hare, linux-fsdevel

On Fri, Oct 30, 2020 at 10:51:07PM +0900, Naohiro Aota wrote:
> This series adds zoned block device support to btrfs.

> Changes from v8:
>  - Direct-IO path now follow several hardware restrictions (other than
>    max_zone_append_size) by using ZONE_APPEND support of iomap
>  - introduces union of fs_info->zone_size and fs_info->zoned [Johannes]
>    - and use btrfs_is_zoned(fs_info) in place of btrfs_fs_incompat(fs_info,
>      ZONED)
>  - print if zoned is enabled or not when printing module info [Johannes]
>  - drop patch of disabling inode_cache on ZONED
>  - moved for_teelog flag to a proper location [Johannes]
>  - Code style fixes [Johannes]
>  - Add comment about adding physical layer things to ordered extent
>    structure
>  - Pass file_offset explicitly to extract_ordered_extent() instead of
>    determining it from bio
>  - Bug fixes
>    - write out fsync region so that the logical address of ordered extents
>      and checksums are properly finalized
>    - free zone_info at umount time
>    - fix superblock log handling when entering zones[1] in the first time
>    - fixes double free of log-tree roots [Johannes] 
>    - Drop erroneous ASSERT in do_allocation_zoned()

As discussed, patches 1-10 are preparatory and can be added to misc-next
but there are still issues regarding coding style and messages. I'll
reply to individual patches as well, list below. They're not the most
useful comments regarding functionality but we won't have much chance to
fix them later and we want to focus on the hard parts.

* all comments start with uppercase, unless it's an identifier
* error messages
  * don't start with uppercase (because there's a prefix already)
  * wording and style needs to be unified
* new locks that are nested in existing locks need to documented
* somewhere (treelog_bg_lock)
* missing { } in if/else if/else blocks
* newlines between function definitions

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 04/41] btrfs: Get zone information of zoned block devices
  2020-10-30 13:51   ` [PATCH v9 04/41] btrfs: Get zone information of zoned block devices Naohiro Aota
  2020-11-02 16:53     ` Josef Bacik
@ 2020-11-03 12:02     ` David Sterba
  1 sibling, 0 replies; 119+ messages in thread
From: David Sterba @ 2020-11-03 12:02 UTC (permalink / raw)
  To: Naohiro Aota
  Cc: linux-btrfs, dsterba, hare, linux-fsdevel, Damien Le Moal, Josef Bacik

On Fri, Oct 30, 2020 at 10:51:11PM +0900, Naohiro Aota wrote:
> +static int btrfs_get_dev_zones(struct btrfs_device *device, u64 pos,
> +			       struct blk_zone *zones, unsigned int *nr_zones)
> +{
> +	int ret;
> +
> +	if (!*nr_zones)
> +		return 0;
> +
> +	ret = blkdev_report_zones(device->bdev, pos >> SECTOR_SHIFT, *nr_zones,
> +				  copy_zone_info_cb, zones);
> +	if (ret < 0) {
> +		btrfs_err_in_rcu(device->fs_info,
> +				 "get zone at %llu on %s failed %d", pos,

		"zoned: failed to read zone %llu on %s (devid %llu)"

> +				 rcu_str_deref(device->name), ret);
> +		return ret;
> +	}
> +	*nr_zones = ret;
> +	if (!ret)
> +		return -EIO;
> +
> +	return 0;
> +}
> +
> +int btrfs_get_dev_zone_info(struct btrfs_device *device)
> +{
> +	struct btrfs_zoned_device_info *zone_info = NULL;
> +	struct block_device *bdev = device->bdev;
> +	sector_t nr_sectors = bdev->bd_part->nr_sects;
> +	sector_t sector = 0;
> +	struct blk_zone *zones = NULL;
> +	unsigned int i, nreported = 0, nr_zones;
> +	unsigned int zone_sectors;
> +	int ret;
> +	char devstr[sizeof(device->fs_info->sb->s_id) +
> +		    sizeof(" (device )") - 1];

Can you avoid the local variable and print the contents conditionally?

> +	kfree(zones);
> +
> +	device->zone_info = zone_info;
> +
> +	devstr[0] = 0;
> +	if (device->fs_info)
> +		snprintf(devstr, sizeof(devstr), " (device %s)",
> +			 device->fs_info->sb->s_id);
> +
> +	rcu_read_lock();
> +	pr_info(
> +"BTRFS info%s: host-%s zoned block device %s, %u zones of %llu sectors",

I think zone size in bytes is more natural, is there a reason to print
that in sectors?

> +		devstr,
> +		bdev_zoned_model(bdev) == BLK_ZONED_HM ? "managed" : "aware",
> +		rcu_str_deref(device->name), zone_info->nr_zones,
> +		zone_info->zone_size >> SECTOR_SHIFT);
> +	rcu_read_unlock();
> +
> +	return 0;
> +
> +out:
> +	kfree(zones);
> +	bitmap_free(zone_info->empty_zones);
> +	bitmap_free(zone_info->seq_zones);
> +	kfree(zone_info);
> +
> +	return ret;
> +}

> --- /dev/null
> +++ b/fs/btrfs/zoned.h
> @@ -0,0 +1,86 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +
> +#ifndef BTRFS_ZONED_H
> +#define BTRFS_ZONED_H

This should at least include types.h as it's using u64
> +
> +struct btrfs_zoned_device_info {
> +	/*
> +	 * Number of zones, zone size and types of zones if bdev is a
> +	 * zoned block device.
> +	 */
> +	u64 zone_size;
> +	u8  zone_size_shift;
> +	u32 nr_zones;
> +	unsigned long *seq_zones;
> +	unsigned long *empty_zones;
> +};
> +
> +#ifdef CONFIG_BLK_DEV_ZONED
> +int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
> +		       struct blk_zone *zone);
> +int btrfs_get_dev_zone_info(struct btrfs_device *device);
> +void btrfs_destroy_dev_zone_info(struct btrfs_device *device);
> +#else /* CONFIG_BLK_DEV_ZONED */
> +static inline int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
> +				     struct blk_zone *zone)
> +{
> +	return 0;
> +}

newline

> +static inline int btrfs_get_dev_zone_info(struct btrfs_device *device)
> +{
> +	return 0;
> +}

newline

> +static inline void btrfs_destroy_dev_zone_info(struct btrfs_device *device) { }
> +#endif

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 05/41] btrfs: Check and enable ZONED mode
  2020-10-30 13:51   ` [PATCH v9 05/41] btrfs: Check and enable ZONED mode Naohiro Aota
@ 2020-11-03 12:13     ` David Sterba
  2020-11-06  9:36       ` Naohiro Aota
  0 siblings, 1 reply; 119+ messages in thread
From: David Sterba @ 2020-11-03 12:13 UTC (permalink / raw)
  To: Naohiro Aota
  Cc: linux-btrfs, dsterba, hare, linux-fsdevel, Johannes Thumshirn,
	Damien Le Moal, Josef Bacik

Below are suggested message updates, common prefix "zoned:" in case it
happens inside the zone mode implementation. Some of them sound strange
when repeating 'zoned', but for clarity I think it should stay, unless
somebody has a better suggestion.

On Fri, Oct 30, 2020 at 10:51:12PM +0900, Naohiro Aota wrote:
> index aac3d6f4e35b..25fd4e97dd2a 100644
> --- a/fs/btrfs/ctree.h
> +++ b/fs/btrfs/ctree.h
> @@ -3595,4 +3601,8 @@ static inline int btrfs_is_testing(struct btrfs_fs_info *fs_info)
>  }
>  #endif
>  
> +static inline bool btrfs_is_zoned(struct btrfs_fs_info *fs_info)
> +{
> +	return fs_info->zoned != 0;
> +}

newline

>  #endif

> diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
> index 6f6d77224c2b..5e3554482af1 100644
> --- a/fs/btrfs/dev-replace.c
> +++ b/fs/btrfs/dev-replace.c
> @@ -238,6 +238,13 @@ static int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
>  		return PTR_ERR(bdev);
>  	}
>  
> +	if (!btrfs_check_device_zone_type(fs_info, bdev)) {
> +		btrfs_err(fs_info,
> +			  "zone type of target device mismatch with the filesystem!");

		"dev-replace: zoned type of target device mismatch with filesystem"

> +		ret = -EINVAL;
> +		goto error;
> +	}
> +
>  	sync_blockdev(bdev);
>  
>  	list_for_each_entry(device, &fs_info->fs_devices->devices, dev_list) {
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index 764001609a15..9bc51cff48b8 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -3130,7 +3133,15 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
>  
>  	btrfs_free_extra_devids(fs_devices, 1);
>  
> +	ret = btrfs_check_zoned_mode(fs_info);
> +	if (ret) {
> +		btrfs_err(fs_info, "failed to init ZONED mode: %d",

		"failed to inititialize zoned mode: %d"

> +				ret);
> +		goto fail_block_groups;
> +	}
> +
>  	ret = btrfs_sysfs_add_fsid(fs_devices);
> +
>  	if (ret) {
>  		btrfs_err(fs_info, "failed to init sysfs fsid interface: %d",
>  				ret);
> --- a/fs/btrfs/zoned.c
> +++ b/fs/btrfs/zoned.c
> +	u64 nr_devices = 0;
> +	u64 zone_size = 0;
> +	int incompat_zoned = btrfs_is_zoned(fs_info);

	const bool

> +	int ret = 0;
> +
> +	/* Count zoned devices */
> +	list_for_each_entry(device, &fs_devices->devices, dev_list) {
> +		enum blk_zoned_model model;
> +
> +		if (!device->bdev)
> +			continue;
> +
> +		model = bdev_zoned_model(device->bdev);
> +		if (model == BLK_ZONED_HM ||
> +		    (model == BLK_ZONED_HA && incompat_zoned)) {
> +			hmzoned_devices++;
> +			if (!zone_size) {
> +				zone_size = device->zone_info->zone_size;
> +			} else if (device->zone_info->zone_size != zone_size) {
> +				btrfs_err(fs_info,
> +					  "Zoned block devices must have equal zone sizes");

				"zoned: unequal block device zone sizes: have %u found %u"

> +				ret = -EINVAL;
> +				goto out;
> +			}
> +		}
> +		nr_devices++;
> +	}
> +
> +	if (!hmzoned_devices && !incompat_zoned)
> +		goto out;
> +
> +	if (!hmzoned_devices && incompat_zoned) {
> +		/* No zoned block device found on ZONED FS */
> +		btrfs_err(fs_info,
> +			  "ZONED enabled file system should have zoned devices");

		"zoned: no zoned devices found on a zoned filesystem"

> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	if (hmzoned_devices && !incompat_zoned) {
> +		btrfs_err(fs_info,
> +			  "Enable ZONED mode to mount HMZONED device");

Is HMZONED reference leftover from previous iterations?

		"zoned: mode not enabled but zoned device found"

> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	if (hmzoned_devices != nr_devices) {
> +		btrfs_err(fs_info,
> +			  "zoned devices cannot be mixed with regular devices");

		"zoned: cannot mix zoned and regular devices"

> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	/*
> +	 * stripe_size is always aligned to BTRFS_STRIPE_LEN in
> +	 * __btrfs_alloc_chunk(). Since we want stripe_len == zone_size,
> +	 * check the alignment here.
> +	 */
> +	if (!IS_ALIGNED(zone_size, BTRFS_STRIPE_LEN)) {
> +		btrfs_err(fs_info,
> +			  "zone size is not aligned to BTRFS_STRIPE_LEN");

		"zoned: zone size not aligned to stripe %u"

> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	fs_info->zone_size = zone_size;
> +
> +	btrfs_info(fs_info, "ZONED mode enabled, zone size %llu B",
> +		   fs_info->zone_size);

	"zoned mode enabled with zone %llu"

> +out:
> +	return ret;
> +}

> --- a/fs/btrfs/zoned.h
> +++ b/fs/btrfs/zoned.h
> @@ -31,6 +34,14 @@ static inline int btrfs_get_dev_zone_info(struct btrfs_device *device)
>  	return 0;
>  }
>  static inline void btrfs_destroy_dev_zone_info(struct btrfs_device *device) { }

newline

> +static inline int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
> +{
> +	if (!btrfs_is_zoned(fs_info))
> +		return 0;
> +
> +	btrfs_err(fs_info, "Zoned block devices support is not enabled");
> +	return -EOPNOTSUPP;
> +}

newline

>  #endif
>  
>  static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos)

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 06/41] btrfs: introduce max_zone_append_size
  2020-10-30 13:51   ` [PATCH v9 06/41] btrfs: introduce max_zone_append_size Naohiro Aota
  2020-11-02 16:57     ` Josef Bacik
@ 2020-11-03 12:16     ` David Sterba
  1 sibling, 0 replies; 119+ messages in thread
From: David Sterba @ 2020-11-03 12:16 UTC (permalink / raw)
  To: Naohiro Aota; +Cc: linux-btrfs, dsterba, hare, linux-fsdevel

On Fri, Oct 30, 2020 at 10:51:13PM +0900, Naohiro Aota wrote:
> --- a/fs/btrfs/ctree.h
> +++ b/fs/btrfs/ctree.h
> @@ -953,6 +953,8 @@ struct btrfs_fs_info {
>  		u64 zone_size;
>  		u64 zoned;
>  	};
> +	/* max size to emit ZONE_APPEND write command */

	/* Max size ... */

> +	u64 max_zone_append_size;
>  
>  #ifdef CONFIG_BTRFS_FS_REF_VERIFY
>  	spinlock_t ref_verify_lock;
> diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
> index e1cdff5af3a3..1b42e13b8227 100644
> --- a/fs/btrfs/zoned.c
> +++ b/fs/btrfs/zoned.c
> @@ -47,6 +47,7 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device)
>  {
>  	struct btrfs_zoned_device_info *zone_info = NULL;
>  	struct block_device *bdev = device->bdev;
> +	struct request_queue *q = bdev_get_queue(bdev);

No single letter variables (exception is 'i' for indexing)

>  	sector_t nr_sectors = bdev->bd_part->nr_sects;
>  	sector_t sector = 0;
>  	struct blk_zone *zones = NULL;
> @@ -70,6 +71,8 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device)
>  	ASSERT(is_power_of_2(zone_sectors));
>  	zone_info->zone_size = (u64)zone_sectors << SECTOR_SHIFT;
>  	zone_info->zone_size_shift = ilog2(zone_info->zone_size);
> +	zone_info->max_zone_append_size =
> +		(u64)queue_max_zone_append_sectors(q) << SECTOR_SHIFT;
>  	zone_info->nr_zones = nr_sectors >> ilog2(bdev_zone_sectors(bdev));
>  	if (!IS_ALIGNED(nr_sectors, zone_sectors))
>  		zone_info->nr_zones++;
> @@ -182,7 +185,8 @@ int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
>  	u64 hmzoned_devices = 0;
>  	u64 nr_devices = 0;
>  	u64 zone_size = 0;
> -	int incompat_zoned = btrfs_is_zoned(fs_info);
> +	u64 max_zone_append_size = 0;
> +	bool incompat_zoned = btrfs_is_zoned(fs_info);

	const bool

>  	int ret = 0;
>  
>  	/* Count zoned devices */
> @@ -195,15 +199,23 @@ int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
>  		model = bdev_zoned_model(device->bdev);
>  		if (model == BLK_ZONED_HM ||
>  		    (model == BLK_ZONED_HA && incompat_zoned)) {
> +			struct btrfs_zoned_device_info *zone_info =
> +				device->zone_info;
> +
>  			hmzoned_devices++;

I must have missed in some previous patch, 'hmzoned' should be zoned?

>  			if (!zone_size) {
> -				zone_size = device->zone_info->zone_size;
> -			} else if (device->zone_info->zone_size != zone_size) {
> +				zone_size = zone_info->zone_size;
> +			} else if (zone_info->zone_size != zone_size) {
>  				btrfs_err(fs_info,
>  					  "Zoned block devices must have equal zone sizes");

				"zoned: devices must have equal zone sizes, have %u found %u"

>  				ret = -EINVAL;
>  				goto out;
>  			}
> +			if (!max_zone_append_size ||
> +			    (zone_info->max_zone_append_size &&
> +			     zone_info->max_zone_append_size < max_zone_append_size))
> +				max_zone_append_size =
> +					zone_info->max_zone_append_size;
>  		}
>  		nr_devices++;
>  	}

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 07/41] btrfs: disallow space_cache in ZONED mode
  2020-10-30 13:51   ` [PATCH v9 07/41] btrfs: disallow space_cache in ZONED mode Naohiro Aota
  2020-11-02 17:02     ` Josef Bacik
@ 2020-11-03 12:48     ` David Sterba
  2020-11-10 10:14       ` Naohiro Aota
  1 sibling, 1 reply; 119+ messages in thread
From: David Sterba @ 2020-11-03 12:48 UTC (permalink / raw)
  To: Naohiro Aota; +Cc: linux-btrfs, dsterba, hare, linux-fsdevel

On Fri, Oct 30, 2020 at 10:51:14PM +0900, Naohiro Aota wrote:
> INODE_MAP_CACHE inode.
> 
> In summary, ZONED will disable:
> 
> | Disabled features | Reason                                              |
> |-------------------+-----------------------------------------------------|
> | RAID/Dup          | Cannot handle two zone append writes to different   |
> |                   | zones                                               |
> |-------------------+-----------------------------------------------------|
> | space_cache (v1)  | In-place updating                                   |
> | NODATACOW         | In-place updating                                   |
> |-------------------+-----------------------------------------------------|
> | fallocate         | Reserved extent will be a write hole                |
> | INODE_MAP_CACHE   | Need pre-allocation. (and will be deprecated?)      |

space_cache is deprecated and actually in current dev cycle (5.11)

> |-------------------+-----------------------------------------------------|
> | MIXED_BG          | Allocated metadata region will be write holes for   |
> |                   | data writes                                         |
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> ---
>  fs/btrfs/super.c | 12 ++++++++++--
>  fs/btrfs/zoned.c | 18 ++++++++++++++++++
>  fs/btrfs/zoned.h |  5 +++++
>  3 files changed, 33 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
> index 3312fe08168f..9064ca62b0a0 100644
> --- a/fs/btrfs/super.c
> +++ b/fs/btrfs/super.c
> @@ -525,8 +525,14 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
>  	cache_gen = btrfs_super_cache_generation(info->super_copy);
>  	if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE))
>  		btrfs_set_opt(info->mount_opt, FREE_SPACE_TREE);
> -	else if (cache_gen)
> -		btrfs_set_opt(info->mount_opt, SPACE_CACHE);
> +	else if (cache_gen) {
> +		if (btrfs_is_zoned(info)) {
> +			btrfs_info(info,
> +			"clearring existing space cache in ZONED mode");

			"zoned: clearing existing space cache"

Is it clearing or just invalidating it? We have the same problem with
enabling v2 so this could share some code once Boris' patches are
merged.

> +			btrfs_set_super_cache_generation(info->super_copy, 0);
> +		} else

		} else {

> +			btrfs_set_opt(info->mount_opt, SPACE_CACHE);

		}
> +	}
>  
>  	/*
>  	 * Even the options are empty, we still need to do extra check

> --- a/fs/btrfs/zoned.c
> +++ b/fs/btrfs/zoned.c
> @@ -265,3 +265,21 @@ int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
>  out:
>  	return ret;
>  }
> +
> +int btrfs_check_mountopts_zoned(struct btrfs_fs_info *info)
> +{
> +	if (!btrfs_is_zoned(info))
> +		return 0;
> +
> +	/*
> +	 * SPACE CACHE writing is not CoWed. Disable that to avoid write

	 * Space cache writing is nod COWed. ...

> +	 * errors in sequential zones.
> +	 */
> +	if (btrfs_test_opt(info, SPACE_CACHE)) {
> +		btrfs_err(info,
> +			  "space cache v1 not supportted in ZONED mode");

		"zoned: space cache v1 is not supported"

> +		return -EOPNOTSUPP;

This should be EINVAL, like invalid cobination. EOPNOTSUPP is for cases
where it's not supported but could be if implemented.

> +	}
> +
> +	return 0;
> +}
> diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h
> index a63f6177f9ee..0b7756a7104d 100644
> --- a/fs/btrfs/zoned.h
> +++ b/fs/btrfs/zoned.h
> @@ -24,6 +24,7 @@ int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
>  int btrfs_get_dev_zone_info(struct btrfs_device *device);
>  void btrfs_destroy_dev_zone_info(struct btrfs_device *device);
>  int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info);
> +int btrfs_check_mountopts_zoned(struct btrfs_fs_info *info);
>  #else /* CONFIG_BLK_DEV_ZONED */
>  static inline int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
>  				     struct blk_zone *zone)
> @@ -43,6 +44,10 @@ static inline int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
>  	btrfs_err(fs_info, "Zoned block devices support is not enabled");
>  	return -EOPNOTSUPP;
>  }

newline

> +static inline int btrfs_check_mountopts_zoned(struct btrfs_fs_info *info)
> +{
> +	return 0;
> +}

newline

>  #endif
>  
>  static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos)

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 08/41] btrfs: disallow NODATACOW in ZONED mode
  2020-10-30 13:51   ` [PATCH v9 08/41] btrfs: disallow NODATACOW " Naohiro Aota
  2020-11-02 17:05     ` Josef Bacik
@ 2020-11-03 12:57     ` David Sterba
  1 sibling, 0 replies; 119+ messages in thread
From: David Sterba @ 2020-11-03 12:57 UTC (permalink / raw)
  To: Naohiro Aota
  Cc: linux-btrfs, dsterba, hare, linux-fsdevel, Johannes Thumshirn

On Fri, Oct 30, 2020 at 10:51:15PM +0900, Naohiro Aota wrote:
>  
> +static int check_fsflags_compatible(struct btrfs_fs_info *fs_info,
> +				    unsigned int flags)
> +{
> +	bool zoned = btrfs_is_zoned(fs_info);

No need for variable when it's one time use.

> +
> +	if (zoned && (flags & FS_NOCOW_FL))
> +		return -EPERM;
> +
> +	return 0;
> +}
> +
> +
>  static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
>  {
>  	struct inode *inode = file_inode(file);
> @@ -230,6 +242,10 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
>  	if (ret)
>  		goto out_unlock;
>  
> +	ret = check_fsflags_compatible(fs_info, fsflags);
> +	if (ret)
> +		goto out_unlock;

This is called under inode lock although it technically does not need
to but I don't see a problem it logically fits to the sequence and
rarely fails.

> +
>  	binode_flags = binode->flags;
>  	if (fsflags & FS_SYNC_FL)
>  		binode_flags |= BTRFS_INODE_SYNC;
> diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
> index 3885fa327049..1939b3ee6c10 100644
> --- a/fs/btrfs/zoned.c
> +++ b/fs/btrfs/zoned.c
> @@ -281,5 +281,11 @@ int btrfs_check_mountopts_zoned(struct btrfs_fs_info *info)
>  		return -EOPNOTSUPP;
>  	}
>  
> +	if (btrfs_test_opt(info, NODATACOW)) {
> +		btrfs_err(info,
> +		  "cannot enable nodatacow with ZONED mode");

		"zoned: NODATACOW not supported"

Eventually all incompatible features will use same message style, there
may be more in the patchset

> +		return -EOPNOTSUPP;

Also EINVAL

> +	}
> +
>  	return 0;
>  }
> -- 
> 2.27.0

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 09/41] btrfs: disable fallocate in ZONED mode
  2020-10-30 13:51   ` [PATCH v9 09/41] btrfs: disable fallocate " Naohiro Aota
@ 2020-11-03 13:00     ` David Sterba
  0 siblings, 0 replies; 119+ messages in thread
From: David Sterba @ 2020-11-03 13:00 UTC (permalink / raw)
  To: Naohiro Aota
  Cc: linux-btrfs, dsterba, hare, linux-fsdevel, Johannes Thumshirn,
	Josef Bacik

On Fri, Oct 30, 2020 at 10:51:16PM +0900, Naohiro Aota wrote:
> In the future, we may be able to implement "in-memory" fallocate() in ZONED
> mode by utilizing space_info->bytes_may_use or so.

> +	/* Do not allow fallocate in ZONED mode */
> +	if (btrfs_is_zoned(btrfs_sb(inode->i_sb)))
> +		return -EOPNOTSUPP;

So here EOPNOTSUPP is ok.

> +
>  	/* Make sure we aren't being give some crap mode */
>  	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
>  		     FALLOC_FL_ZERO_RANGE))
> -- 
> 2.27.0

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 10/41] btrfs: disallow mixed-bg in ZONED mode
  2020-10-30 13:51   ` [PATCH v9 10/41] btrfs: disallow mixed-bg " Naohiro Aota
@ 2020-11-03 13:01     ` David Sterba
  0 siblings, 0 replies; 119+ messages in thread
From: David Sterba @ 2020-11-03 13:01 UTC (permalink / raw)
  To: Naohiro Aota; +Cc: linux-btrfs, dsterba, hare, linux-fsdevel, Josef Bacik

On Fri, Oct 30, 2020 at 10:51:17PM +0900, Naohiro Aota wrote:
> --- a/fs/btrfs/zoned.c
> +++ b/fs/btrfs/zoned.c
> @@ -257,6 +257,13 @@ int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
>  		goto out;
>  	}
>  
> +	if (btrfs_fs_incompat(fs_info, MIXED_GROUPS)) {
> +		btrfs_err(fs_info,
> +			  "ZONED mode is not allowed for mixed block groups");

		"zoned: mixed block groups not supported"

> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
>  	fs_info->zone_size = zone_size;
>  	fs_info->max_zone_append_size = max_zone_append_size;
>  
> -- 
> 2.27.0

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 11/41] btrfs: implement log-structured superblock for ZONED mode
  2020-10-30 13:51   ` [PATCH v9 11/41] btrfs: implement log-structured superblock for " Naohiro Aota
  2020-11-02 18:22     ` Josef Bacik
  2020-11-02 18:54     ` Josef Bacik
@ 2020-11-03 13:15     ` David Sterba
  2020-11-03 14:10     ` David Sterba
  3 siblings, 0 replies; 119+ messages in thread
From: David Sterba @ 2020-11-03 13:15 UTC (permalink / raw)
  To: Naohiro Aota; +Cc: linux-btrfs, dsterba, hare, linux-fsdevel

On Fri, Oct 30, 2020 at 10:51:18PM +0900, Naohiro Aota wrote:
> --- a/fs/btrfs/block-group.c
> +++ b/fs/btrfs/block-group.c
> @@ -1723,6 +1723,7 @@ int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
>  static int exclude_super_stripes(struct btrfs_block_group *cache)
>  {
>  	struct btrfs_fs_info *fs_info = cache->fs_info;
> +	bool zoned = btrfs_is_zoned(fs_info);

	const bool

>  	u64 bytenr;
>  	u64 *logical;
>  	int stripe_len;
> @@ -1744,6 +1745,14 @@ static int exclude_super_stripes(struct btrfs_block_group *cache)
>  		if (ret)
>  			return ret;
>  
> +		/* shouldn't have super stripes in sequential zones */

		/* Shouldn't ... */

> +		if (zoned && nr) {
> +			btrfs_err(fs_info,
> +				  "Zoned btrfs's block group %llu should not have super blocks",

			"zoned: block group %llu must not contain super block"

> +				  cache->start);
> +			return -EUCLEAN;
> +		}
> +
>  		while (nr--) {
>  			u64 len = min_t(u64, stripe_len,
>  				cache->start + cache->length - logical[nr]);
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index 9bc51cff48b8..fd8b970ee92c 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -3423,10 +3423,17 @@ struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev,
>  {
>  	struct btrfs_super_block *super;
>  	struct page *page;
> -	u64 bytenr;
> +	u64 bytenr, bytenr_orig;
>  	struct address_space *mapping = bdev->bd_inode->i_mapping;
> +	int ret;
> +
> +	bytenr_orig = btrfs_sb_offset(copy_num);
> +	ret = btrfs_sb_log_location_bdev(bdev, copy_num, READ, &bytenr);
> +	if (ret == -ENOENT)
> +		return ERR_PTR(-EINVAL);
> +	else if (ret)
> +		return ERR_PTR(ret);
>  
> -	bytenr = btrfs_sb_offset(copy_num);
>  	if (bytenr + BTRFS_SUPER_INFO_SIZE >= i_size_read(bdev->bd_inode))
>  		return ERR_PTR(-EINVAL);
>  
> @@ -3440,7 +3447,7 @@ struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev,
>  		return ERR_PTR(-ENODATA);
>  	}
>  
> -	if (btrfs_super_bytenr(super) != bytenr) {
> +	if (btrfs_super_bytenr(super) != bytenr_orig) {
>  		btrfs_release_disk_super(super);
>  		return ERR_PTR(-EINVAL);
>  	}
> @@ -3495,7 +3502,8 @@ static int write_dev_supers(struct btrfs_device *device,
>  	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
>  	int i;
>  	int errors = 0;
> -	u64 bytenr;
> +	int ret;
> +	u64 bytenr, bytenr_orig;
>  
>  	if (max_mirrors == 0)
>  		max_mirrors = BTRFS_SUPER_MIRROR_MAX;
> @@ -3507,12 +3515,21 @@ static int write_dev_supers(struct btrfs_device *device,
>  		struct bio *bio;
>  		struct btrfs_super_block *disk_super;
>  
> -		bytenr = btrfs_sb_offset(i);
> +		bytenr_orig = btrfs_sb_offset(i);
> +		ret = btrfs_sb_log_location(device, i, WRITE, &bytenr);
> +		if (ret == -ENOENT)
> +			continue;
> +		else if (ret < 0) {
> +			btrfs_err(device->fs_info, "couldn't get super block location for mirror %d",
> +				  i);
> +			errors++;
> +			continue;
> +		}
>  		if (bytenr + BTRFS_SUPER_INFO_SIZE >=
>  		    device->commit_total_bytes)
>  			break;
>  
> -		btrfs_set_super_bytenr(sb, bytenr);
> +		btrfs_set_super_bytenr(sb, bytenr_orig);
>  
>  		crypto_shash_digest(shash, (const char *)sb + BTRFS_CSUM_SIZE,
>  				    BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE,
> @@ -3557,6 +3574,7 @@ static int write_dev_supers(struct btrfs_device *device,
>  			bio->bi_opf |= REQ_FUA;
>  
>  		btrfsic_submit_bio(bio);
> +		btrfs_advance_sb_log(device, i);
>  	}
>  	return errors < i ? 0 : -1;
>  }
> @@ -3573,6 +3591,7 @@ static int wait_dev_supers(struct btrfs_device *device, int max_mirrors)
>  	int i;
>  	int errors = 0;
>  	bool primary_failed = false;
> +	int ret;
>  	u64 bytenr;
>  
>  	if (max_mirrors == 0)
> @@ -3581,7 +3600,15 @@ static int wait_dev_supers(struct btrfs_device *device, int max_mirrors)
>  	for (i = 0; i < max_mirrors; i++) {
>  		struct page *page;
>  
> -		bytenr = btrfs_sb_offset(i);
> +		ret = btrfs_sb_log_location(device, i, READ, &bytenr);
> +		if (ret == -ENOENT)

		if (...) {

> +			break;

		} else if (...) {

> +		else if (ret < 0) {
> +			errors++;
> +			if (i == 0)
> +				primary_failed = true;
> +			continue;
> +		}
>  		if (bytenr + BTRFS_SUPER_INFO_SIZE >=
>  		    device->commit_total_bytes)
>  			break;
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -1282,7 +1282,8 @@ void btrfs_release_disk_super(struct btrfs_super_block *super)
>  }
>  
>  static struct btrfs_super_block *btrfs_read_disk_super(struct block_device *bdev,
> -						       u64 bytenr)
> +						       u64 bytenr,
> +						       u64 bytenr_orig)
>  {
>  	struct btrfs_super_block *disk_super;
>  	struct page *page;
> @@ -1313,7 +1314,7 @@ static struct btrfs_super_block *btrfs_read_disk_super(struct block_device *bdev
>  	/* align our pointer to the offset of the super block */
>  	disk_super = p + offset_in_page(bytenr);
>  
> -	if (btrfs_super_bytenr(disk_super) != bytenr ||
> +	if (btrfs_super_bytenr(disk_super) != bytenr_orig ||
>  	    btrfs_super_magic(disk_super) != BTRFS_MAGIC) {
>  		btrfs_release_disk_super(p);
>  		return ERR_PTR(-EINVAL);
> @@ -1348,7 +1349,8 @@ struct btrfs_device *btrfs_scan_one_device(const char *path, fmode_t flags,
>  	bool new_device_added = false;
>  	struct btrfs_device *device = NULL;
>  	struct block_device *bdev;
> -	u64 bytenr;
> +	u64 bytenr, bytenr_orig;
> +	int ret;
>  
>  	lockdep_assert_held(&uuid_mutex);
>  
> @@ -1358,14 +1360,18 @@ struct btrfs_device *btrfs_scan_one_device(const char *path, fmode_t flags,
>  	 * So, we need to add a special mount option to scan for
>  	 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
>  	 */
> -	bytenr = btrfs_sb_offset(0);
>  	flags |= FMODE_EXCL;
>  
>  	bdev = blkdev_get_by_path(path, flags, holder);
>  	if (IS_ERR(bdev))
>  		return ERR_CAST(bdev);
>  
> -	disk_super = btrfs_read_disk_super(bdev, bytenr);
> +	bytenr_orig = btrfs_sb_offset(0);
> +	ret = btrfs_sb_log_location_bdev(bdev, 0, READ, &bytenr);
> +	if (ret)
> +		return ERR_PTR(ret);
> +
> +	disk_super = btrfs_read_disk_super(bdev, bytenr, bytenr_orig);
>  	if (IS_ERR(disk_super)) {
>  		device = ERR_CAST(disk_super);
>  		goto error_bdev_put;
> @@ -2029,6 +2035,11 @@ void btrfs_scratch_superblocks(struct btrfs_fs_info *fs_info,
>  		if (IS_ERR(disk_super))
>  			continue;
>  
> +		if (bdev_is_zoned(bdev)) {
> +			btrfs_reset_sb_log_zones(bdev, copy_num);
> +			continue;
> +		}
> +
>  		memset(&disk_super->magic, 0, sizeof(disk_super->magic));
>  
>  		page = virt_to_page(disk_super);
> diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
> index ae509699da14..d5487cba203b 100644
> --- a/fs/btrfs/zoned.c
> +++ b/fs/btrfs/zoned.c
> @@ -20,6 +20,25 @@ static int copy_zone_info_cb(struct blk_zone *zone, unsigned int idx,
>  	return 0;
>  }
>  
> +static int sb_write_pointer(struct block_device *bdev, struct blk_zone *zone,
> +			    u64 *wp_ret);

Please define sb_write_pointer here instead of the prototype for a
static function.

> +
> +static inline u32 sb_zone_number(u8 shift, int mirror)
> +{
> +	ASSERT(mirror < BTRFS_SUPER_MIRROR_MAX);
> +
> +	switch (mirror) {
> +	case 0:
> +		return 0;
> +	case 1:
> +		return 16;
> +	case 2:
> +		return min(btrfs_sb_offset(mirror) >> shift, 1024ULL);
> +	}
> +
> +	return 0;
> +}
> +
>  static int btrfs_get_dev_zones(struct btrfs_device *device, u64 pos,
>  			       struct blk_zone *zones, unsigned int *nr_zones)
>  {
> @@ -123,6 +142,49 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device)
>  		goto out;
>  	}
>  
> +	/* validate superblock log */

	/* Validate ... */

> +	nr_zones = 2;
> +	for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
> +		u32 sb_zone = sb_zone_number(zone_info->zone_size_shift, i);
> +		u64 sb_wp;
> +
> +		if (sb_zone + 1 >= zone_info->nr_zones)
> +			continue;
> +
> +		sector = sb_zone << (zone_info->zone_size_shift - SECTOR_SHIFT);
> +		ret = btrfs_get_dev_zones(device, sector << SECTOR_SHIFT,
> +					  &zone_info->sb_zones[2 * i],
> +					  &nr_zones);
> +		if (ret)
> +			goto out;
> +		if (nr_zones != 2) {
> +			btrfs_err_in_rcu(device->fs_info,
> +			"failed to read SB log zone info at device %s zone %u",
> +					 rcu_str_deref(device->name), sb_zone);

			"zoned: failed to read super block log zone info at devid %llu zone %u"

> +			ret = -EIO;

What are the possible reasons here? EIO would fit reading error but if
the zone is missing it's more like EUCLEAN.

> +			goto out;
> +		}
> +
> +		/*
> +		 * If zones[0] is conventional, always use the beggining of
> +		 * the zone to record superblock. No need to validate in
> +		 * that case.
> +		 */
> +		if (zone_info->sb_zones[2 * i].type == BLK_ZONE_TYPE_CONVENTIONAL)
> +			continue;
> +
> +		ret = sb_write_pointer(device->bdev,
> +				       &zone_info->sb_zones[2 * i], &sb_wp);
> +		if (ret != -ENOENT && ret) {
> +			btrfs_err_in_rcu(device->fs_info,
> +				"SB log zone corrupted: device %s zone %u",
> +					 rcu_str_deref(device->name), sb_zone);

			"zoned: super block log zone corrupted devid %llu zone %u"

The device path would be also good in all the messages, this could be
tweaked later.

> +			ret = -EUCLEAN;
> +			goto out;
> +		}
> +	}
> +
> +
>  	kfree(zones);
>  
>  	device->zone_info = zone_info;
> @@ -296,3 +358,252 @@ int btrfs_check_mountopts_zoned(struct btrfs_fs_info *info)
>  
>  	return 0;
>  }
> +
> +static int sb_write_pointer(struct block_device *bdev, struct blk_zone *zones,
> +			    u64 *wp_ret)
> +{
> +	bool empty[2];
> +	bool full[2];
> +	sector_t sector;
> +
> +	ASSERT(zones[0].type != BLK_ZONE_TYPE_CONVENTIONAL &&
> +	       zones[1].type != BLK_ZONE_TYPE_CONVENTIONAL);
> +
> +	empty[0] = zones[0].cond == BLK_ZONE_COND_EMPTY;

	empty[0] = (zones[0].cond == BLK_ZONE_COND_EMPTY);

> +	empty[1] = zones[1].cond == BLK_ZONE_COND_EMPTY;
> +	full[0] = zones[0].cond == BLK_ZONE_COND_FULL;
> +	full[1] = zones[1].cond == BLK_ZONE_COND_FULL;

Same

> +
> +	/*
> +	 * Possible state of log buffer zones
> +	 *
> +	 *   E I F
> +	 * E * x 0
> +	 * I 0 x 0
> +	 * F 1 1 C
> +	 *
> +	 * Row: zones[0]
> +	 * Col: zones[1]
> +	 * State:
> +	 *   E: Empty, I: In-Use, F: Full
> +	 * Log position:
> +	 *   *: Special case, no superblock is written
> +	 *   0: Use write pointer of zones[0]
> +	 *   1: Use write pointer of zones[1]
> +	 *   C: Compare SBs from zones[0] and zones[1], use the newer one
> +	 *   x: Invalid state
> +	 */
> +
> +	if (empty[0] && empty[1]) {
> +		/* special case to distinguish no superblock to read */

		/* Special ... */

> +		*wp_ret = zones[0].start << SECTOR_SHIFT;
> +		return -ENOENT;
> +	} else if (full[0] && full[1]) {
> +		/* Compare two super blocks */
> +		struct address_space *mapping = bdev->bd_inode->i_mapping;
> +		struct page *page[2];
> +		struct btrfs_super_block *super[2];
> +		int i;
> +
> +		for (i = 0; i < 2; i++) {
> +			u64 bytenr = ((zones[i].start + zones[i].len) << SECTOR_SHIFT) -
> +				BTRFS_SUPER_INFO_SIZE;
> +
> +			page[i] = read_cache_page_gfp(mapping, bytenr >> PAGE_SHIFT, GFP_NOFS);
> +			if (IS_ERR(page[i])) {
> +				if (i == 1)
> +					btrfs_release_disk_super(super[0]);
> +				return PTR_ERR(page[i]);
> +			}
> +			super[i] = page_address(page[i]);
> +		}
> +
> +		if (super[0]->generation > super[1]->generation)
> +			sector = zones[1].start;
> +		else
> +			sector = zones[0].start;
> +
> +		for (i = 0; i < 2; i++)
> +			btrfs_release_disk_super(super[i]);
> +	} else if (!full[0] && (empty[1] || full[1])) {
> +		sector = zones[0].wp;
> +	} else if (full[0]) {
> +		sector = zones[1].wp;
> +	} else {
> +		return -EUCLEAN;
> +	}
> +	*wp_ret = sector << SECTOR_SHIFT;
> +	return 0;
> +}
> --- a/fs/btrfs/zoned.h
> +++ b/fs/btrfs/zoned.h
> @@ -4,6 +4,8 @@
>  #define BTRFS_ZONED_H
>  
>  #include <linux/blkdev.h>
> +#include "volumes.h"
> +#include "disk-io.h"
>  
>  struct btrfs_zoned_device_info {
>  	/*
> @@ -16,6 +18,7 @@ struct btrfs_zoned_device_info {
>  	u32 nr_zones;
>  	unsigned long *seq_zones;
>  	unsigned long *empty_zones;
> +	struct blk_zone sb_zones[2 * BTRFS_SUPER_MIRROR_MAX];
>  };
>  
>  #ifdef CONFIG_BLK_DEV_ZONED
> @@ -25,6 +28,12 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device);
>  void btrfs_destroy_dev_zone_info(struct btrfs_device *device);
>  int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info);
>  int btrfs_check_mountopts_zoned(struct btrfs_fs_info *info);
> +int btrfs_sb_log_location_bdev(struct block_device *bdev, int mirror, int rw,
> +			       u64 *bytenr_ret);
> +int btrfs_sb_log_location(struct btrfs_device *device, int mirror, int rw,
> +			  u64 *bytenr_ret);
> +void btrfs_advance_sb_log(struct btrfs_device *device, int mirror);
> +int btrfs_reset_sb_log_zones(struct block_device *bdev, int mirror);
>  #else /* CONFIG_BLK_DEV_ZONED */
>  static inline int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
>  				     struct blk_zone *zone)
> @@ -48,6 +57,26 @@ static inline int btrfs_check_mountopts_zoned(struct btrfs_fs_info *info)
>  {
>  	return 0;
>  }

newline

> +static inline int btrfs_sb_log_location_bdev(struct block_device *bdev,
> +					     int mirror, int rw,
> +					     u64 *bytenr_ret)
> +{
> +	*bytenr_ret = btrfs_sb_offset(mirror);
> +	return 0;
> +}

newline

> +static inline int btrfs_sb_log_location(struct btrfs_device *device, int mirror,
> +					int rw, u64 *bytenr_ret)
> +{
> +	*bytenr_ret = btrfs_sb_offset(mirror);
> +	return 0;
> +}

newline

> +static inline void btrfs_advance_sb_log(struct btrfs_device *device,
> +					int mirror) { }

newline

> +static inline int btrfs_reset_sb_log_zones(struct block_device *bdev,
> +					   int mirror)
> +{
> +	return 0;
> +}

newline

>  #endif
>  
>  static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos)
> @@ -115,4 +144,15 @@ static inline bool btrfs_check_device_zone_type(struct btrfs_fs_info *fs_info,
>  	return bdev_zoned_model(bdev) != BLK_ZONED_HM;
>  }
>  
> +static inline bool btrfs_check_super_location(struct btrfs_device *device,
> +					      u64 pos)
> +{
> +	/*
> +	 * On a non-zoned device, any address is OK. On a zoned device,
> +	 * non-SEQUENTIAL WRITE REQUIRED zones are capable.
> +	 */
> +	return device->zone_info == NULL ||
> +	       !btrfs_dev_is_sequential(device, pos);
> +}
> +
>  #endif
> -- 
> 2.27.0

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 12/41] btrfs: implement zoned chunk allocator
  2020-10-30 13:51   ` [PATCH v9 12/41] btrfs: implement zoned chunk allocator Naohiro Aota
  2020-11-02 20:09     ` Josef Bacik
@ 2020-11-03 13:23     ` David Sterba
  1 sibling, 0 replies; 119+ messages in thread
From: David Sterba @ 2020-11-03 13:23 UTC (permalink / raw)
  To: Naohiro Aota; +Cc: linux-btrfs, dsterba, hare, linux-fsdevel

On Fri, Oct 30, 2020 at 10:51:19PM +0900, Naohiro Aota wrote:
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -1416,6 +1416,14 @@ static bool contains_pending_extent(struct btrfs_device *device, u64 *start,
>  	return false;
>  }
>  
> +static inline u64 dev_extent_search_start_zoned(struct btrfs_device *device,
> +						u64 start)
> +{
> +	start = max_t(u64, start,
> +		      max_t(u64, device->zone_info->zone_size, SZ_1M));

Can you rewrite that as ifs?

> +	return btrfs_zone_align(device, start);
> +}
> +
>  static u64 dev_extent_search_start(struct btrfs_device *device, u64 start)
>  {
>  	switch (device->fs_devices->chunk_alloc_policy) {
> @@ -1426,11 +1434,57 @@ static u64 dev_extent_search_start(struct btrfs_device *device, u64 start)
>  		 * make sure to start at an offset of at least 1MB.
>  		 */
>  		return max_t(u64, start, SZ_1M);
> +	case BTRFS_CHUNK_ALLOC_ZONED:
> +		return dev_extent_search_start_zoned(device, start);
>  	default:
>  		BUG();
>  	}
>  }
>  
> +static bool dev_extent_hole_check_zoned(struct btrfs_device *device,
> +					u64 *hole_start, u64 *hole_size,
> +					u64 num_bytes)
> +{
> +	u64 zone_size = device->zone_info->zone_size;
> +	u64 pos;
> +	int ret;
> +	int changed = 0;
> +
> +	ASSERT(IS_ALIGNED(*hole_start, zone_size));
> +
> +	while (*hole_size > 0) {
> +		pos = btrfs_find_allocatable_zones(device, *hole_start,
> +						   *hole_start + *hole_size,
> +						   num_bytes);
> +		if (pos != *hole_start) {
> +			*hole_size = *hole_start + *hole_size - pos;
> +			*hole_start = pos;
> +			changed = 1;
> +			if (*hole_size < num_bytes)
> +				break;
> +		}
> +
> +		ret = btrfs_ensure_empty_zones(device, pos, num_bytes);
> +
> +		/* range is ensured to be empty */

		/* Range ... */

> +		if (!ret)
> +			return changed;
> +
> +		/* given hole range was invalid (outside of device) */

		/* Given ... */

> +		if (ret == -ERANGE) {
> +			*hole_start += *hole_size;
> +			*hole_size = 0;
> +			return 1;
> +		}
> +
> +		*hole_start += zone_size;
> +		*hole_size -= zone_size;
> +		changed = 1;
> +	}
> +
> +	return changed;
> +}
> +
>  /**
>   * dev_extent_hole_check - check if specified hole is suitable for allocation
>   * @device:	the device which we have the hole
> @@ -1463,6 +1517,10 @@ static bool dev_extent_hole_check(struct btrfs_device *device, u64 *hole_start,
>  	case BTRFS_CHUNK_ALLOC_REGULAR:
>  		/* No extra check */
>  		break;
> +	case BTRFS_CHUNK_ALLOC_ZONED:
> +		changed |= dev_extent_hole_check_zoned(device, hole_start,
> +						       hole_size, num_bytes);
> +		break;
>  	default:
>  		BUG();
>  	}
> @@ -1517,6 +1575,9 @@ static int find_free_dev_extent_start(struct btrfs_device *device,
>  
>  	search_start = dev_extent_search_start(device, search_start);
>  
> +	WARN_ON(device->zone_info &&
> +		!IS_ALIGNED(num_bytes, device->zone_info->zone_size));
> +
>  	path = btrfs_alloc_path();
>  	if (!path)
>  		return -ENOMEM;
> @@ -4907,6 +4968,37 @@ static void init_alloc_chunk_ctl_policy_regular(
>  	ctl->dev_extent_min = BTRFS_STRIPE_LEN * ctl->dev_stripes;
>  }
>  
> +static void
> +init_alloc_chunk_ctl_policy_zoned(struct btrfs_fs_devices *fs_devices,
> +				  struct alloc_chunk_ctl *ctl)

static void init_alloc_chunk_ctl_policy_zoned(

Ie. type and name on one line

> +{
> +	u64 zone_size = fs_devices->fs_info->zone_size;
> +	u64 limit;
> +	int min_num_stripes = ctl->devs_min * ctl->dev_stripes;
> +	int min_data_stripes = (min_num_stripes - ctl->nparity) / ctl->ncopies;
> +	u64 min_chunk_size = min_data_stripes * zone_size;
> +	u64 type = ctl->type;
> +
> +	ctl->max_stripe_size = zone_size;
> +	if (type & BTRFS_BLOCK_GROUP_DATA) {
> +		ctl->max_chunk_size = round_down(BTRFS_MAX_DATA_CHUNK_SIZE,
> +						 zone_size);
> +	} else if (type & BTRFS_BLOCK_GROUP_METADATA) {
> +		ctl->max_chunk_size = ctl->max_stripe_size;
> +	} else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
> +		ctl->max_chunk_size = 2 * ctl->max_stripe_size;
> +		ctl->devs_max = min_t(int, ctl->devs_max,
> +				      BTRFS_MAX_DEVS_SYS_CHUNK);
> +	}
> +
> +	/* We don't want a chunk larger than 10% of writable space */
> +	limit = max(round_down(div_factor(fs_devices->total_rw_bytes, 1),
> +			       zone_size),
> +		    min_chunk_size);
> +	ctl->max_chunk_size = min(limit, ctl->max_chunk_size);
> +	ctl->dev_extent_min = zone_size * ctl->dev_stripes;
> +}
> +
>  static void init_alloc_chunk_ctl(struct btrfs_fs_devices *fs_devices,
>  				 struct alloc_chunk_ctl *ctl)
>  {
> @@ -4927,6 +5019,9 @@ static void init_alloc_chunk_ctl(struct btrfs_fs_devices *fs_devices,
>  	case BTRFS_CHUNK_ALLOC_REGULAR:
>  		init_alloc_chunk_ctl_policy_regular(fs_devices, ctl);
>  		break;
> +	case BTRFS_CHUNK_ALLOC_ZONED:
> +		init_alloc_chunk_ctl_policy_zoned(fs_devices, ctl);
> +		break;
>  	default:
>  		BUG();
>  	}
> @@ -5053,6 +5148,40 @@ static int decide_stripe_size_regular(struct alloc_chunk_ctl *ctl,
>  	return 0;
>  }
>  
> +static int decide_stripe_size_zoned(struct alloc_chunk_ctl *ctl,
> +				    struct btrfs_device_info *devices_info)
> +{
> +	u64 zone_size = devices_info[0].dev->zone_info->zone_size;
> +	/* number of stripes that count for block group size */

	/* Number ... */

> +	int data_stripes;
> +
> +	/*
> +	 * It should hold because:
> +	 *    dev_extent_min == dev_extent_want == zone_size * dev_stripes
> +	 */
> +	ASSERT(devices_info[ctl->ndevs - 1].max_avail == ctl->dev_extent_min);
> +
> +	ctl->stripe_size = zone_size;
> +	ctl->num_stripes = ctl->ndevs * ctl->dev_stripes;
> +	data_stripes = (ctl->num_stripes - ctl->nparity) / ctl->ncopies;
> +
> +	/*
> +	 * stripe_size is fixed in ZONED. Reduce ndevs instead.

/* One line comment if it fits to 80 cols */

> +	 */
> +	if (ctl->stripe_size * data_stripes > ctl->max_chunk_size) {
> +		ctl->ndevs = div_u64(div_u64(ctl->max_chunk_size * ctl->ncopies,
> +					     ctl->stripe_size) + ctl->nparity,
> +				     ctl->dev_stripes);
> +		ctl->num_stripes = ctl->ndevs * ctl->dev_stripes;
> +		data_stripes = (ctl->num_stripes - ctl->nparity) / ctl->ncopies;
> +		ASSERT(ctl->stripe_size * data_stripes <= ctl->max_chunk_size);
> +	}
> +
> +	ctl->chunk_size = ctl->stripe_size * data_stripes;
> +
> +	return 0;
> +}
> +
>  static int decide_stripe_size(struct btrfs_fs_devices *fs_devices,
>  			      struct alloc_chunk_ctl *ctl,
>  			      struct btrfs_device_info *devices_info)
> --- a/fs/btrfs/zoned.c
> +++ b/fs/btrfs/zoned.c
> @@ -607,3 +610,126 @@ int btrfs_reset_sb_log_zones(struct block_device *bdev, int mirror)
>  				sb_zone << zone_sectors_shift, zone_sectors * 2,
>  				GFP_NOFS);
>  }
> +
> +/*
> + * btrfs_check_allocatable_zones - find allocatable zones within give region
> + * @device:	the device to allocate a region
> + * @hole_start: the position of the hole to allocate the region
> + * @num_bytes:	the size of wanted region
> + * @hole_size:	the size of hole
> + *
> + * Allocatable region should not contain any superblock locations.
> + */
> +u64 btrfs_find_allocatable_zones(struct btrfs_device *device, u64 hole_start,
> +				 u64 hole_end, u64 num_bytes)
> +{
> +	struct btrfs_zoned_device_info *zinfo = device->zone_info;
> +	u8 shift = zinfo->zone_size_shift;
> +	u64 nzones = num_bytes >> shift;
> +	u64 pos = hole_start;
> +	u64 begin, end;
> +	u64 sb_pos;
> +	bool have_sb;
> +	int i;
> +
> +	ASSERT(IS_ALIGNED(hole_start, zinfo->zone_size));
> +	ASSERT(IS_ALIGNED(num_bytes, zinfo->zone_size));
> +
> +	while (pos < hole_end) {
> +		begin = pos >> shift;
> +		end = begin + nzones;
> +
> +		if (end > zinfo->nr_zones)
> +			return hole_end;
> +
> +		/* check if zones in the region are all empty */

		/* Check ... */

> +		if (btrfs_dev_is_sequential(device, pos) &&
> +		    find_next_zero_bit(zinfo->empty_zones, end, begin) != end) {
> +			pos += zinfo->zone_size;
> +			continue;
> +		}
> +
> +		have_sb = false;
> +		for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
> +			sb_pos = sb_zone_number(zinfo->zone_size, i);
> +			if (!(end < sb_pos || sb_pos + 1 < begin)) {
> +				have_sb = true;
> +				pos = (sb_pos + 2) << shift;
> +				break;
> +			}
> +		}
> +		if (!have_sb)
> +			break;
> +	}
> +
> +	return pos;
> +}
> +
> +int btrfs_reset_device_zone(struct btrfs_device *device, u64 physical,
> +			    u64 length, u64 *bytes)
> +{
> +	int ret;
> +
> +	*bytes = 0;
> +	ret = blkdev_zone_mgmt(device->bdev, REQ_OP_ZONE_RESET,
> +			       physical >> SECTOR_SHIFT, length >> SECTOR_SHIFT,
> +			       GFP_NOFS);
> +	if (ret)
> +		return ret;
> +
> +	*bytes = length;
> +	while (length) {
> +		btrfs_dev_set_zone_empty(device, physical);
> +		physical += device->zone_info->zone_size;
> +		length -= device->zone_info->zone_size;
> +	}
> +
> +	return 0;
> +}
> +
> +int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size)
> +{
> +	struct btrfs_zoned_device_info *zinfo = device->zone_info;
> +	u8 shift = zinfo->zone_size_shift;
> +	unsigned long begin = start >> shift;
> +	unsigned long end = (start + size) >> shift;
> +	u64 pos;
> +	int ret;
> +
> +	ASSERT(IS_ALIGNED(start, zinfo->zone_size));
> +	ASSERT(IS_ALIGNED(size, zinfo->zone_size));
> +
> +	if (end > zinfo->nr_zones)
> +		return -ERANGE;
> +
> +	/* all the zones are conventional */

	/* All ... */

> +	if (find_next_bit(zinfo->seq_zones, begin, end) == end)
> +		return 0;
> +
> +	/* all the zones are sequential and empty */

	/* All ... */

> +	if (find_next_zero_bit(zinfo->seq_zones, begin, end) == end &&
> +	    find_next_zero_bit(zinfo->empty_zones, begin, end) == end)
> +		return 0;
> +
> +	for (pos = start; pos < start + size; pos += zinfo->zone_size) {
> +		u64 reset_bytes;
> +
> +		if (!btrfs_dev_is_sequential(device, pos) ||
> +		    btrfs_dev_is_empty_zone(device, pos))
> +			continue;
> +
> +		/* free regions should be empty */

		/* Free ... */

> +		btrfs_warn_in_rcu(
> +			device->fs_info,
> +			"resetting device %s zone %llu for allocation",

		"zoned: resetting device %s (devid %llu) zone %llu for allocation

> +			rcu_str_deref(device->name), pos >> shift);
> +		WARN_ON_ONCE(1);
> +
> +		ret = btrfs_reset_device_zone(device, pos, zinfo->zone_size,
> +					      &reset_bytes);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return 0;
> +}
> diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h
> index 447c4e5ffcbb..24dd0c9561f9 100644
> --- a/fs/btrfs/zoned.h
> +++ b/fs/btrfs/zoned.h
> @@ -34,6 +34,11 @@ int btrfs_sb_log_location(struct btrfs_device *device, int mirror, int rw,
>  			  u64 *bytenr_ret);
>  void btrfs_advance_sb_log(struct btrfs_device *device, int mirror);
>  int btrfs_reset_sb_log_zones(struct block_device *bdev, int mirror);
> +u64 btrfs_find_allocatable_zones(struct btrfs_device *device, u64 hole_start,
> +				 u64 hole_end, u64 num_bytes);
> +int btrfs_reset_device_zone(struct btrfs_device *device, u64 physical,
> +			    u64 length, u64 *bytes);
> +int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size);
>  #else /* CONFIG_BLK_DEV_ZONED */
>  static inline int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
>  				     struct blk_zone *zone)
> @@ -77,6 +82,23 @@ static inline int btrfs_reset_sb_log_zones(struct block_device *bdev,
>  {
>  	return 0;
>  }

newline

> +static inline u64 btrfs_find_allocatable_zones(struct btrfs_device *device,
> +					       u64 hole_start, u64 hole_end,
> +					       u64 num_bytes)
> +{
> +	return hole_start;
> +}

newline

> +static inline int btrfs_reset_device_zone(struct btrfs_device *device,
> +					  u64 physical, u64 length, u64 *bytes)
> +{
> +	*bytes = 0;
> +	return 0;
> +}

newline

> +static inline int btrfs_ensure_empty_zones(struct btrfs_device *device,
> +					   u64 start, u64 size)
> +{
> +	return 0;
> +}

newline

>  #endif
>  
>  static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos)
> @@ -155,4 +177,12 @@ static inline bool btrfs_check_super_location(struct btrfs_device *device,
>  	       !btrfs_dev_is_sequential(device, pos);
>  }
>  
> +static inline u64 btrfs_zone_align(struct btrfs_device *device, u64 pos)

I can't tell from the name what it does, something like
btrfs_align_offset_to_zone would be more clear.

> +{
> +	if (!device->zone_info)
> +		return pos;
> +
> +	return ALIGN(pos, device->zone_info->zone_size);
> +}
> +
>  #endif
> -- 
> 2.27.0

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 14/41] btrfs: load zone's alloction offset
  2020-10-30 13:51   ` [PATCH v9 14/41] btrfs: load zone's alloction offset Naohiro Aota
  2020-11-02 20:25     ` Josef Bacik
@ 2020-11-03 13:28     ` David Sterba
  1 sibling, 0 replies; 119+ messages in thread
From: David Sterba @ 2020-11-03 13:28 UTC (permalink / raw)
  To: Naohiro Aota; +Cc: linux-btrfs, dsterba, hare, linux-fsdevel

On Fri, Oct 30, 2020 at 10:51:21PM +0900, Naohiro Aota wrote:
> @@ -733,3 +739,150 @@ int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size)
>  
>  	return 0;
>  }
> +
> +int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache)
> +{
> +	struct btrfs_fs_info *fs_info = cache->fs_info;
> +	struct extent_map_tree *em_tree = &fs_info->mapping_tree;
> +	struct extent_map *em;
> +	struct map_lookup *map;
> +	struct btrfs_device *device;
> +	u64 logical = cache->start;
> +	u64 length = cache->length;
> +	u64 physical = 0;
> +	int ret;
> +	int i;
> +	unsigned int nofs_flag;
> +	u64 *alloc_offsets = NULL;
> +	u32 num_sequential = 0, num_conventional = 0;
> +
> +	if (!btrfs_is_zoned(fs_info))
> +		return 0;
> +
> +	/* Sanity check */
> +	if (!IS_ALIGNED(length, fs_info->zone_size)) {
> +		btrfs_err(fs_info, "unaligned block group at %llu + %llu",

		"zoned: block group %llu len %llu unaligned to zone size %u"

> +			  logical, length);
> +		return -EIO;
> +	}
> +
> +	/* Get the chunk mapping */
> +	read_lock(&em_tree->lock);
> +	em = lookup_extent_mapping(em_tree, logical, length);
> +	read_unlock(&em_tree->lock);
> +
> +	if (!em)
> +		return -EINVAL;
> +
> +	map = em->map_lookup;
> +
> +	/*
> +	 * Get the zone type: if the group is mapped to a non-sequential zone,
> +	 * there is no need for the allocation offset (fit allocation is OK).
> +	 */
> +	alloc_offsets = kcalloc(map->num_stripes, sizeof(*alloc_offsets),
> +				GFP_NOFS);
> +	if (!alloc_offsets) {
> +		free_extent_map(em);
> +		return -ENOMEM;
> +	}
> +
> +	for (i = 0; i < map->num_stripes; i++) {
> +		bool is_sequential;
> +		struct blk_zone zone;
> +
> +		device = map->stripes[i].dev;
> +		physical = map->stripes[i].physical;
> +
> +		if (device->bdev == NULL) {
> +			alloc_offsets[i] = WP_MISSING_DEV;
> +			continue;
> +		}
> +
> +		is_sequential = btrfs_dev_is_sequential(device, physical);
> +		if (is_sequential)
> +			num_sequential++;
> +		else
> +			num_conventional++;
> +
> +		if (!is_sequential) {
> +			alloc_offsets[i] = WP_CONVENTIONAL;
> +			continue;
> +		}
> +
> +		/*
> +		 * This zone will be used for allocation, so mark this
> +		 * zone non-empty.
> +		 */
> +		btrfs_dev_clear_zone_empty(device, physical);
> +
> +		/*
> +		 * The group is mapped to a sequential zone. Get the zone write
> +		 * pointer to determine the allocation offset within the zone.
> +		 */
> +		WARN_ON(!IS_ALIGNED(physical, fs_info->zone_size));
> +		nofs_flag = memalloc_nofs_save();
> +		ret = btrfs_get_dev_zone(device, physical, &zone);
> +		memalloc_nofs_restore(nofs_flag);
> +		if (ret == -EIO || ret == -EOPNOTSUPP) {
> +			ret = 0;
> +			alloc_offsets[i] = WP_MISSING_DEV;
> +			continue;
> +		} else if (ret) {
> +			goto out;
> +		}
> +
> +		switch (zone.cond) {
> +		case BLK_ZONE_COND_OFFLINE:
> +		case BLK_ZONE_COND_READONLY:
> +			btrfs_err(fs_info, "Offline/readonly zone %llu",

			"zoned: offline/readonly zone %llu on device %s (devid %llu)"

> +				  physical >> device->zone_info->zone_size_shift);
> +			alloc_offsets[i] = WP_MISSING_DEV;
> +			break;
> +		case BLK_ZONE_COND_EMPTY:
> +			alloc_offsets[i] = 0;
> +			break;
> +		case BLK_ZONE_COND_FULL:
> +			alloc_offsets[i] = fs_info->zone_size;
> +			break;
> +		default:
> +			/* Partially used zone */
> +			alloc_offsets[i] =
> +				((zone.wp - zone.start) << SECTOR_SHIFT);
> +			break;
> +		}
> +	}
> +
> +	if (num_conventional > 0) {
> +		/*
> +		 * Since conventional zones does not have write pointer, we

				  ... zones do not ...

> +		 * cannot determine alloc_offset from the pointer
> +		 */
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	switch (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
> +	case 0: /* single */
> +		cache->alloc_offset = alloc_offsets[0];
> +		break;
> +	case BTRFS_BLOCK_GROUP_DUP:
> +	case BTRFS_BLOCK_GROUP_RAID1:
> +	case BTRFS_BLOCK_GROUP_RAID0:
> +	case BTRFS_BLOCK_GROUP_RAID10:
> +	case BTRFS_BLOCK_GROUP_RAID5:
> +	case BTRFS_BLOCK_GROUP_RAID6:
> +		/* non-SINGLE profiles are not supported yet */
> +	default:
> +		btrfs_err(fs_info, "Unsupported profile on ZONED %s",

		"zoned: profile %s not supported"

> +			  btrfs_bg_type_to_raid_name(map->type));
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +out:
> +	kfree(alloc_offsets);
> +	free_extent_map(em);
> +
> +	return ret;
> +}
> diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h
> index 24dd0c9561f9..90ed43a25595 100644
> --- a/fs/btrfs/zoned.h
> +++ b/fs/btrfs/zoned.h
> @@ -39,6 +39,7 @@ u64 btrfs_find_allocatable_zones(struct btrfs_device *device, u64 hole_start,
>  int btrfs_reset_device_zone(struct btrfs_device *device, u64 physical,
>  			    u64 length, u64 *bytes);
>  int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size);
> +int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache);
>  #else /* CONFIG_BLK_DEV_ZONED */
>  static inline int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
>  				     struct blk_zone *zone)
> @@ -99,6 +100,11 @@ static inline int btrfs_ensure_empty_zones(struct btrfs_device *device,
>  {
>  	return 0;
>  }

newline

> +static inline int btrfs_load_block_group_zone_info(
> +	struct btrfs_block_group *cache)
> +{
> +	return 0;
> +}

newline

>  #endif
>  
>  static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos)
> -- 
> 2.27.0

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 15/41] btrfs: emulate write pointer for conventional zones
  2020-10-30 13:51   ` [PATCH v9 15/41] btrfs: emulate write pointer for conventional zones Naohiro Aota
  2020-11-02 20:37     ` Josef Bacik
@ 2020-11-03 13:32     ` David Sterba
  1 sibling, 0 replies; 119+ messages in thread
From: David Sterba @ 2020-11-03 13:32 UTC (permalink / raw)
  To: Naohiro Aota; +Cc: linux-btrfs, dsterba, hare, linux-fsdevel

On Fri, Oct 30, 2020 at 10:51:22PM +0900, Naohiro Aota wrote:
> +	struct btrfs_key found_key;
> +	int slot;
> +	int ret;
> +	u64 length;
> +
> +	path = btrfs_alloc_path();
> +	if (!path)
> +		return -ENOMEM;
> +
> +	search_key.objectid = cache->start + cache->length;
> +	search_key.type = 0;
> +	search_key.offset = 0;
> +
> +	ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
> +	if (ret < 0)
> +		goto out;
> +	ASSERT(ret != 0);

This should be a runtime check not an assert, if this happens it's
likely a corruption

> +	slot = path->slots[0];
> +	leaf = path->nodes[0];
> +	ASSERT(slot != 0);

Same

> +	slot--;
> +	btrfs_item_key_to_cpu(leaf, &found_key, slot);
> +
> +	if (found_key.objectid < cache->start) {
> +		*offset_ret = 0;
> +	} else if (found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
> +		struct btrfs_key extent_item_key;
> +
> +		if (found_key.objectid != cache->start) {
> +			ret = -EUCLEAN;
> +			goto out;
> +		}
> +
> +		length = 0;
> +
> +		/* metadata may have METADATA_ITEM_KEY */

		/* Metadata ... */

> +		if (slot == 0) {
> +			btrfs_set_path_blocking(path);
> +			ret = btrfs_prev_leaf(root, path);
> +			if (ret < 0)
> +				goto out;
> +			if (ret == 0) {
> +				slot = btrfs_header_nritems(leaf) - 1;
> +				btrfs_item_key_to_cpu(leaf, &extent_item_key,
> +						      slot);
> +			}
> +		} else {
> +			btrfs_item_key_to_cpu(leaf, &extent_item_key, slot - 1);
> +			ret = 0;
> +		}
> +
> +		if (ret == 0 &&
> +		    extent_item_key.objectid == cache->start) {
> +			if (extent_item_key.type == BTRFS_METADATA_ITEM_KEY)

			if (...) {

> +				length = fs_info->nodesize;

			} else if (...) {

> +			else if (extent_item_key.type == BTRFS_EXTENT_ITEM_KEY)
> +				length = extent_item_key.offset;

			} else {

> +			else {
> +				ret = -EUCLEAN;
> +				goto out;
> +			}
> +		}
> +
> +		*offset_ret = length;
> +	} else if (found_key.type == BTRFS_EXTENT_ITEM_KEY ||
> +		   found_key.type == BTRFS_METADATA_ITEM_KEY) {
> +
> +		if (found_key.type == BTRFS_EXTENT_ITEM_KEY)
> +			length = found_key.offset;
> +		else
> +			length = fs_info->nodesize;
> +
> +		if (!(found_key.objectid >= cache->start &&
> +		       found_key.objectid + length <=
> +		       cache->start + cache->length)) {
> +			ret = -EUCLEAN;
> +			goto out;
> +		}
> +		*offset_ret = found_key.objectid + length - cache->start;
> +	} else {
> +		ret = -EUCLEAN;
> +		goto out;
> +	}
> +	ret = 0;
> +
> +out:
> +	btrfs_free_path(path);
> +	return ret;
> +}
> +
>  int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache)
>  {
>  	struct btrfs_fs_info *fs_info = cache->fs_info;
> @@ -754,6 +852,7 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache)
>  	int i;
>  	unsigned int nofs_flag;
>  	u64 *alloc_offsets = NULL;
> +	u64 emulated_offset = 0;
>  	u32 num_sequential = 0, num_conventional = 0;
>  
>  	if (!btrfs_is_zoned(fs_info))
> @@ -854,12 +953,12 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache)
>  	}
>  
>  	if (num_conventional > 0) {
> -		/*
> -		 * Since conventional zones does not have write pointer, we
> -		 * cannot determine alloc_offset from the pointer
> -		 */
> -		ret = -EINVAL;
> -		goto out;
> +		ret = emulate_write_pointer(cache, &emulated_offset);
> +		if (ret || map->num_stripes == num_conventional) {
> +			if (!ret)
> +				cache->alloc_offset = emulated_offset;
> +			goto out;
> +		}
>  	}
>  
>  	switch (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
> @@ -881,6 +980,14 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache)
>  	}
>  
>  out:
> +	/* an extent is allocated after the write pointer */

	/* An ... */

> +	if (num_conventional && emulated_offset > cache->alloc_offset) {
> +		btrfs_err(fs_info,
> +			  "got wrong write pointer in BG %llu: %llu > %llu",

		"zoned: got wrong write pointer in block group %llu found %llu emulated %llu"

> +			  logical, emulated_offset, cache->alloc_offset);
> +		ret = -EIO;
> +	}
> +
>  	kfree(alloc_offsets);
>  	free_extent_map(em);
>  
> -- 
> 2.27.0

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 11/41] btrfs: implement log-structured superblock for ZONED mode
  2020-10-30 13:51   ` [PATCH v9 11/41] btrfs: implement log-structured superblock for " Naohiro Aota
                       ` (2 preceding siblings ...)
  2020-11-03 13:15     ` David Sterba
@ 2020-11-03 14:10     ` David Sterba
  2020-11-06 10:37       ` Naohiro Aota
  3 siblings, 1 reply; 119+ messages in thread
From: David Sterba @ 2020-11-03 14:10 UTC (permalink / raw)
  To: Naohiro Aota; +Cc: linux-btrfs, dsterba, hare, linux-fsdevel

On Fri, Oct 30, 2020 at 10:51:18PM +0900, Naohiro Aota wrote:
> Superblock (and its copies) is the only data structure in btrfs which has a
> fixed location on a device. Since we cannot overwrite in a sequential write
> required zone, we cannot place superblock in the zone. One easy solution is
> limiting superblock and copies to be placed only in conventional zones.
> However, this method has two downsides: one is reduced number of superblock
> copies. The location of the second copy of superblock is 256GB, which is in
> a sequential write required zone on typical devices in the market today.
> So, the number of superblock and copies is limited to be two.  Second
> downside is that we cannot support devices which have no conventional zones
> at all.
> 
> To solve these two problems, we employ superblock log writing. It uses two
> zones as a circular buffer to write updated superblocks. Once the first
> zone is filled up, start writing into the second buffer. Then, when the
> both zones are filled up and before start writing to the first zone again,
> it reset the first zone.
> 
> We can determine the position of the latest superblock by reading write
> pointer information from a device. One corner case is when the both zones
> are full. For this situation, we read out the last superblock of each
> zone, and compare them to determine which zone is older.
> 
> The following zones are reserved as the circular buffer on ZONED btrfs.
> 
> - The primary superblock: zones 0 and 1
> - The first copy: zones 16 and 17
> - The second copy: zones 1024 or zone at 256GB which is minimum, and next
>   to it
> 
> If these reserved zones are conventional, superblock is written fixed at
> the start of the zone without logging.

I don't have a clear picture here.

In case there's a conventional zone covering 0 and 1st copy (64K and
64M) it'll be overwritten. What happens for 2nd copy that's at 256G?
sb-log?

For all-sequential drive, the 0 and 1st copy are in the first zone.
You say 0 and 1, but how come if the minimum zone size we ever expect is
256M?

The circular buffer comprises zones covering all superblock copies? I
mean one buffer for 2 or more sb copies? The problem is that we'll have
just one copy of the current superblock. Or I misunderstood.

My idea is that we have primary zone, unfortunatelly covering 2
superblocks but let it be. Second zone contains 2nd superblock copy
(256G), we can assume that devices will be bigger than that.

Then the circular buffers happen in each zone, so first one will go from
offset 64K up to the zone size (256M or 1G).  Second zone rotates from
offset 0 to end of the zone.

The positive outcome of that is that both zones contain the latest
superblock after succesful write and their write pointer is slightly out
of sync, so they never have to be reset at the same time.

In numbers:
- first zone 64K .. 256M, 65520 superblocks
- second zone 256G .. 245G+256M, 65536 superblocks

The difference is 16 superblock updates, which should be enough to let
the zone resets happen far apart.

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 16/41] btrfs: track unusable bytes for zones
  2020-10-30 13:51   ` [PATCH v9 16/41] btrfs: track unusable bytes for zones Naohiro Aota
@ 2020-11-03 14:25     ` Josef Bacik
  0 siblings, 0 replies; 119+ messages in thread
From: Josef Bacik @ 2020-11-03 14:25 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> In zoned btrfs a region that was once written then freed is not usable
> until we reset the underlying zone. So we need to distinguish such
> unusable space from usable free space.
> 
> Therefore we need to introduce the "zone_unusable" field  to the block
> group structure, and "bytes_zone_unusable" to the space_info structure to
> track the unusable space.
> 
> Pinned bytes are always reclaimed to the unusable space. But, when an
> allocated region is returned before using e.g., the block group becomes
> read-only between allocation time and reservation time, we can safely
> return the region to the block group. For the situation, this commit
> introduces "btrfs_add_free_space_unused". This behaves the same as
> btrfs_add_free_space() on regular btrfs. On zoned btrfs, it rewinds the
> allocation offset.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> ---
>   fs/btrfs/block-group.c      | 19 +++++++++-----
>   fs/btrfs/block-group.h      |  1 +
>   fs/btrfs/extent-tree.c      | 15 ++++++++---
>   fs/btrfs/free-space-cache.c | 52 +++++++++++++++++++++++++++++++++++++
>   fs/btrfs/free-space-cache.h |  4 +++
>   fs/btrfs/space-info.c       | 13 ++++++----
>   fs/btrfs/space-info.h       |  4 ++-
>   fs/btrfs/sysfs.c            |  2 ++
>   fs/btrfs/zoned.c            | 22 ++++++++++++++++
>   fs/btrfs/zoned.h            |  2 ++
>   10 files changed, 118 insertions(+), 16 deletions(-)
> 
> diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
> index 920b2708c7f2..c34bd2dbdf82 100644
> --- a/fs/btrfs/block-group.c
> +++ b/fs/btrfs/block-group.c
> @@ -1080,12 +1080,15 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
>   		WARN_ON(block_group->space_info->total_bytes
>   			< block_group->length);
>   		WARN_ON(block_group->space_info->bytes_readonly
> -			< block_group->length);
> +			< block_group->length - block_group->zone_unusable);
> +		WARN_ON(block_group->space_info->bytes_zone_unusable
> +			< block_group->zone_unusable);
>   		WARN_ON(block_group->space_info->disk_total
>   			< block_group->length * factor);
>   	}
>   	block_group->space_info->total_bytes -= block_group->length;
> -	block_group->space_info->bytes_readonly -= block_group->length;
> +	block_group->space_info->bytes_readonly -=
> +		(block_group->length - block_group->zone_unusable);
>   	block_group->space_info->disk_total -= block_group->length * factor;
>   
>   	spin_unlock(&block_group->space_info->lock);
> @@ -1229,7 +1232,7 @@ static int inc_block_group_ro(struct btrfs_block_group *cache, int force)
>   	}
>   
>   	num_bytes = cache->length - cache->reserved - cache->pinned -
> -		    cache->bytes_super - cache->used;
> +		    cache->bytes_super - cache->zone_unusable - cache->used;
>   
>   	/*
>   	 * Data never overcommits, even in mixed mode, so do just the straight
> @@ -1973,6 +1976,8 @@ static int read_one_block_group(struct btrfs_fs_info *info,
>   		btrfs_free_excluded_extents(cache);
>   	}
>   
> +	btrfs_calc_zone_unusable(cache);
> +
>   	ret = btrfs_add_block_group_cache(info, cache);
>   	if (ret) {
>   		btrfs_remove_free_space_cache(cache);
> @@ -1980,7 +1985,8 @@ static int read_one_block_group(struct btrfs_fs_info *info,
>   	}
>   	trace_btrfs_add_block_group(info, cache, 0);
>   	btrfs_update_space_info(info, cache->flags, cache->length,
> -				cache->used, cache->bytes_super, &space_info);
> +				cache->used, cache->bytes_super,
> +				cache->zone_unusable, &space_info);
>   
>   	cache->space_info = space_info;
>   
> @@ -2217,7 +2223,7 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans, u64 bytes_used,
>   	 */
>   	trace_btrfs_add_block_group(fs_info, cache, 1);
>   	btrfs_update_space_info(fs_info, cache->flags, size, bytes_used,
> -				cache->bytes_super, &cache->space_info);
> +				cache->bytes_super, 0, &cache->space_info);
>   	btrfs_update_global_block_rsv(fs_info);
>   
>   	link_block_group(cache);
> @@ -2325,7 +2331,8 @@ void btrfs_dec_block_group_ro(struct btrfs_block_group *cache)
>   	spin_lock(&cache->lock);
>   	if (!--cache->ro) {
>   		num_bytes = cache->length - cache->reserved -
> -			    cache->pinned - cache->bytes_super - cache->used;
> +			    cache->pinned - cache->bytes_super -
> +			    cache->zone_unusable - cache->used;
>   		sinfo->bytes_readonly -= num_bytes;
>   		list_del_init(&cache->ro_list);
>   	}
> diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
> index 14e3043c9ce7..5be47f4bfea7 100644
> --- a/fs/btrfs/block-group.h
> +++ b/fs/btrfs/block-group.h
> @@ -189,6 +189,7 @@ struct btrfs_block_group {
>   	 * allocation. This is used only with ZONED mode enabled.
>   	 */
>   	u64 alloc_offset;
> +	u64 zone_unusable;
>   };
>   
>   static inline u64 btrfs_block_group_end(struct btrfs_block_group *block_group)
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index 3b21fee13e77..fad53c702d8a 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -34,6 +34,7 @@
>   #include "block-group.h"
>   #include "discard.h"
>   #include "rcu-string.h"
> +#include "zoned.h"
>   
>   #undef SCRAMBLE_DELAYED_REFS
>   
> @@ -2807,9 +2808,11 @@ static int unpin_extent_range(struct btrfs_fs_info *fs_info,
>   			cache = btrfs_lookup_block_group(fs_info, start);
>   			BUG_ON(!cache); /* Logic error */
>   
> -			cluster = fetch_cluster_info(fs_info,
> -						     cache->space_info,
> -						     &empty_cluster);
> +			if (!btrfs_is_zoned(fs_info))
> +				cluster = fetch_cluster_info(fs_info,
> +							     cache->space_info,
> +							     &empty_cluster);

Move the !btrfs_is_zoned() check into fetch_cluster_info so we don't have to 
indent even more.

> +
>   			empty_cluster <<= 1;
>   		}
>   
> @@ -2846,7 +2849,11 @@ static int unpin_extent_range(struct btrfs_fs_info *fs_info,
>   		space_info->max_extent_size = 0;
>   		percpu_counter_add_batch(&space_info->total_bytes_pinned,
>   			    -len, BTRFS_TOTAL_BYTES_PINNED_BATCH);
> -		if (cache->ro) {
> +		if (btrfs_is_zoned(fs_info)) {
> +			/* need reset before reusing in zoned Block Group */
> +			space_info->bytes_zone_unusable += len;
> +			readonly = true;
> +		} else if (cache->ro) {
>   			space_info->bytes_readonly += len;
>   			readonly = true;
>   		}
> diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
> index af0013d3df63..cfa466319166 100644
> --- a/fs/btrfs/free-space-cache.c
> +++ b/fs/btrfs/free-space-cache.c
> @@ -2467,6 +2467,8 @@ int __btrfs_add_free_space(struct btrfs_fs_info *fs_info,
>   	int ret = 0;
>   	u64 filter_bytes = bytes;
>   
> +	ASSERT(!btrfs_is_zoned(fs_info));
> +
>   	info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
>   	if (!info)
>   		return -ENOMEM;
> @@ -2524,11 +2526,44 @@ int __btrfs_add_free_space(struct btrfs_fs_info *fs_info,
>   	return ret;
>   }
>   
> +int __btrfs_add_free_space_zoned(struct btrfs_block_group *block_group,
> +				 u64 bytenr, u64 size, bool used)
> +{

This is only used in free-space-cache.c, it can be made static.

> +	struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
> +	u64 offset = bytenr - block_group->start;
> +	u64 to_free, to_unusable;
> +
> +	spin_lock(&ctl->tree_lock);
> +	if (!used)
> +		to_free = size;
> +	else if (offset >= block_group->alloc_offset)
> +		to_free = size;
> +	else if (offset + size <= block_group->alloc_offset)
> +		to_free = 0;
> +	else
> +		to_free = offset + size - block_group->alloc_offset;
> +	to_unusable = size - to_free;
> +
> +	ctl->free_space += to_free;
> +	block_group->zone_unusable += to_unusable;
> +	spin_unlock(&ctl->tree_lock);
> +	if (!used) {
> +		spin_lock(&block_group->lock);
> +		block_group->alloc_offset -= size;
> +		spin_unlock(&block_group->lock);
> +	}
> +	return 0;
> +}
> +
>   int btrfs_add_free_space(struct btrfs_block_group *block_group,
>   			 u64 bytenr, u64 size)
>   {
>   	enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
>   
> +	if (btrfs_is_zoned(block_group->fs_info))
> +		return __btrfs_add_free_space_zoned(block_group, bytenr, size,
> +						    true);
> +
>   	if (btrfs_test_opt(block_group->fs_info, DISCARD_SYNC))
>   		trim_state = BTRFS_TRIM_STATE_TRIMMED;
>   
> @@ -2537,6 +2572,16 @@ int btrfs_add_free_space(struct btrfs_block_group *block_group,
>   				      bytenr, size, trim_state);
>   }
>   
> +int btrfs_add_free_space_unused(struct btrfs_block_group *block_group,
> +				u64 bytenr, u64 size)
> +{
> +	if (btrfs_is_zoned(block_group->fs_info))
> +		return __btrfs_add_free_space_zoned(block_group, bytenr, size,
> +						    false);
> +
> +	return btrfs_add_free_space(block_group, bytenr, size);
> +}
> +
>   /*
>    * This is a subtle distinction because when adding free space back in general,
>    * we want it to be added as untrimmed for async. But in the case where we add
> @@ -2547,6 +2592,10 @@ int btrfs_add_free_space_async_trimmed(struct btrfs_block_group *block_group,
>   {
>   	enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
>   
> +	if (btrfs_is_zoned(block_group->fs_info))
> +		return __btrfs_add_free_space_zoned(block_group, bytenr, size,
> +						    true);
> +
>   	if (btrfs_test_opt(block_group->fs_info, DISCARD_SYNC) ||
>   	    btrfs_test_opt(block_group->fs_info, DISCARD_ASYNC))
>   		trim_state = BTRFS_TRIM_STATE_TRIMMED;
> @@ -2564,6 +2613,9 @@ int btrfs_remove_free_space(struct btrfs_block_group *block_group,
>   	int ret;
>   	bool re_search = false;
>   
> +	if (btrfs_is_zoned(block_group->fs_info))
> +		return 0;
> +
>   	spin_lock(&ctl->tree_lock);
>   
>   again:
> diff --git a/fs/btrfs/free-space-cache.h b/fs/btrfs/free-space-cache.h
> index e3d5e0ad8f8e..7081216257a8 100644
> --- a/fs/btrfs/free-space-cache.h
> +++ b/fs/btrfs/free-space-cache.h
> @@ -114,8 +114,12 @@ int __btrfs_add_free_space(struct btrfs_fs_info *fs_info,
>   			   struct btrfs_free_space_ctl *ctl,
>   			   u64 bytenr, u64 size,
>   			   enum btrfs_trim_state trim_state);
> +int __btrfs_add_free_space_zoned(struct btrfs_block_group *block_group,
> +				 u64 bytenr, u64 size, bool used);
>   int btrfs_add_free_space(struct btrfs_block_group *block_group,
>   			 u64 bytenr, u64 size);
> +int btrfs_add_free_space_unused(struct btrfs_block_group *block_group,
> +				u64 bytenr, u64 size);
>   int btrfs_add_free_space_async_trimmed(struct btrfs_block_group *block_group,
>   				       u64 bytenr, u64 size);
>   int btrfs_remove_free_space(struct btrfs_block_group *block_group,
> diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c
> index 64099565ab8f..bbbf3c1412a4 100644
> --- a/fs/btrfs/space-info.c
> +++ b/fs/btrfs/space-info.c
> @@ -163,6 +163,7 @@ u64 __pure btrfs_space_info_used(struct btrfs_space_info *s_info,
>   	ASSERT(s_info);
>   	return s_info->bytes_used + s_info->bytes_reserved +
>   		s_info->bytes_pinned + s_info->bytes_readonly +
> +		s_info->bytes_zone_unusable +
>   		(may_use_included ? s_info->bytes_may_use : 0);
>   }
>   
> @@ -257,7 +258,7 @@ int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
>   
>   void btrfs_update_space_info(struct btrfs_fs_info *info, u64 flags,
>   			     u64 total_bytes, u64 bytes_used,
> -			     u64 bytes_readonly,
> +			     u64 bytes_readonly, u64 bytes_zone_unusable,
>   			     struct btrfs_space_info **space_info)
>   {
>   	struct btrfs_space_info *found;
> @@ -273,6 +274,7 @@ void btrfs_update_space_info(struct btrfs_fs_info *info, u64 flags,
>   	found->bytes_used += bytes_used;
>   	found->disk_used += bytes_used * factor;
>   	found->bytes_readonly += bytes_readonly;
> +	found->bytes_zone_unusable += bytes_zone_unusable;
>   	if (total_bytes > 0)
>   		found->full = 0;
>   	btrfs_try_granting_tickets(info, found);
> @@ -422,10 +424,10 @@ static void __btrfs_dump_space_info(struct btrfs_fs_info *fs_info,
>   		   info->total_bytes - btrfs_space_info_used(info, true),
>   		   info->full ? "" : "not ");
>   	btrfs_info(fs_info,
> -		"space_info total=%llu, used=%llu, pinned=%llu, reserved=%llu, may_use=%llu, readonly=%llu",
> +		"space_info total=%llu, used=%llu, pinned=%llu, reserved=%llu, may_use=%llu, readonly=%llu zone_unusable=%llu",
>   		info->total_bytes, info->bytes_used, info->bytes_pinned,
>   		info->bytes_reserved, info->bytes_may_use,
> -		info->bytes_readonly);
> +		info->bytes_readonly, info->bytes_zone_unusable);
>   
>   	DUMP_BLOCK_RSV(fs_info, global_block_rsv);
>   	DUMP_BLOCK_RSV(fs_info, trans_block_rsv);
> @@ -454,9 +456,10 @@ void btrfs_dump_space_info(struct btrfs_fs_info *fs_info,
>   	list_for_each_entry(cache, &info->block_groups[index], list) {
>   		spin_lock(&cache->lock);
>   		btrfs_info(fs_info,
> -			"block group %llu has %llu bytes, %llu used %llu pinned %llu reserved %s",
> +			"block group %llu has %llu bytes, %llu used %llu pinned %llu reserved %llu zone_unusable %s",
>   			cache->start, cache->length, cache->used, cache->pinned,
> -			cache->reserved, cache->ro ? "[readonly]" : "");
> +			cache->reserved, cache->zone_unusable,
> +			cache->ro ? "[readonly]" : "");
>   		spin_unlock(&cache->lock);
>   		btrfs_dump_free_space(cache, bytes);
>   	}
> diff --git a/fs/btrfs/space-info.h b/fs/btrfs/space-info.h
> index 5646393b928c..ee003ffba956 100644
> --- a/fs/btrfs/space-info.h
> +++ b/fs/btrfs/space-info.h
> @@ -17,6 +17,8 @@ struct btrfs_space_info {
>   	u64 bytes_may_use;	/* number of bytes that may be used for
>   				   delalloc/allocations */
>   	u64 bytes_readonly;	/* total bytes that are read only */
> +	u64 bytes_zone_unusable;	/* total bytes that are unusable until
> +					   resetting the device zone */
>   
>   	u64 max_extent_size;	/* This will hold the maximum extent size of
>   				   the space info if we had an ENOSPC in the
> @@ -119,7 +121,7 @@ DECLARE_SPACE_INFO_UPDATE(bytes_pinned, "pinned");
>   int btrfs_init_space_info(struct btrfs_fs_info *fs_info);
>   void btrfs_update_space_info(struct btrfs_fs_info *info, u64 flags,
>   			     u64 total_bytes, u64 bytes_used,
> -			     u64 bytes_readonly,
> +			     u64 bytes_readonly, u64 bytes_zone_unusable,
>   			     struct btrfs_space_info **space_info);
>   struct btrfs_space_info *btrfs_find_space_info(struct btrfs_fs_info *info,
>   					       u64 flags);
> diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
> index 828006020bbd..ea679803da9b 100644
> --- a/fs/btrfs/sysfs.c
> +++ b/fs/btrfs/sysfs.c
> @@ -635,6 +635,7 @@ SPACE_INFO_ATTR(bytes_pinned);
>   SPACE_INFO_ATTR(bytes_reserved);
>   SPACE_INFO_ATTR(bytes_may_use);
>   SPACE_INFO_ATTR(bytes_readonly);
> +SPACE_INFO_ATTR(bytes_zone_unusable);
>   SPACE_INFO_ATTR(disk_used);
>   SPACE_INFO_ATTR(disk_total);
>   BTRFS_ATTR(space_info, total_bytes_pinned,
> @@ -648,6 +649,7 @@ static struct attribute *space_info_attrs[] = {
>   	BTRFS_ATTR_PTR(space_info, bytes_reserved),
>   	BTRFS_ATTR_PTR(space_info, bytes_may_use),
>   	BTRFS_ATTR_PTR(space_info, bytes_readonly),
> +	BTRFS_ATTR_PTR(space_info, bytes_zone_unusable),
>   	BTRFS_ATTR_PTR(space_info, disk_used),
>   	BTRFS_ATTR_PTR(space_info, disk_total),
>   	BTRFS_ATTR_PTR(space_info, total_bytes_pinned),
> diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
> index 8f58d0853cc3..d94a2c363a47 100644
> --- a/fs/btrfs/zoned.c
> +++ b/fs/btrfs/zoned.c
> @@ -993,3 +993,25 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache)
>   
>   	return ret;
>   }
> +
> +void btrfs_calc_zone_unusable(struct btrfs_block_group *cache)
> +{
> +	u64 unusable, free;
> +
> +	if (!btrfs_is_zoned(cache->fs_info))
> +		return;
> +
> +	WARN_ON(cache->bytes_super != 0);
> +	unusable = cache->alloc_offset - cache->used;
> +	free = cache->length - cache->alloc_offset;

newline.

> +	/* we only need ->free_space in ALLOC_SEQ BGs */
> +	cache->last_byte_to_unpin = (u64)-1;
> +	cache->cached = BTRFS_CACHE_FINISHED;
> +	cache->free_space_ctl->free_space = free;
> +	cache->zone_unusable = unusable;

newline.

> +	/*
> +	 * Should not have any excluded extents. Just
> +	 * in case, though.
> +	 */
> +	btrfs_free_excluded_extents(cache);
> +}

Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 17/41] btrfs: do sequential extent allocation in ZONED mode
  2020-10-30 13:51   ` [PATCH v9 17/41] btrfs: do sequential extent allocation in ZONED mode Naohiro Aota
@ 2020-11-03 14:28     ` Josef Bacik
  0 siblings, 0 replies; 119+ messages in thread
From: Josef Bacik @ 2020-11-03 14:28 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> This commit implements a sequential extent allocator for the ZONED mode.
> This allocator just needs to check if there is enough space in the block
> group. Therefor the allocator never manages bitmaps or clusters. Also add
> ASSERTs to the corresponding functions.
> 
> Actually, with zone append writing, it is unnecessary to track the
> allocation offset. It only needs to check space availability. But, by
> tracking the offset and returning the offset as an allocated region, we can
> skip modification of ordered extents and checksum information when there is
> no IO reordering.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 18/41] btrfs: reset zones of unused block groups
  2020-10-30 13:51   ` [PATCH v9 18/41] btrfs: reset zones of unused block groups Naohiro Aota
@ 2020-11-03 14:34     ` Josef Bacik
  2020-11-10 10:40       ` Naohiro Aota
  0 siblings, 1 reply; 119+ messages in thread
From: Josef Bacik @ 2020-11-03 14:34 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> For an ZONED volume, a block group maps to a zone of the device. For
> deleted unused block groups, the zone of the block group can be reset to
> rewind the zone write pointer at the start of the zone.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> ---
>   fs/btrfs/block-group.c |  8 ++++++--
>   fs/btrfs/extent-tree.c | 17 ++++++++++++-----
>   fs/btrfs/zoned.h       | 16 ++++++++++++++++
>   3 files changed, 34 insertions(+), 7 deletions(-)
> 
> diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
> index d67f9cabe5c1..82d556368c85 100644
> --- a/fs/btrfs/block-group.c
> +++ b/fs/btrfs/block-group.c
> @@ -1468,8 +1468,12 @@ void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
>   		if (!async_trim_enabled && btrfs_test_opt(fs_info, DISCARD_ASYNC))
>   			goto flip_async;
>   
> -		/* DISCARD can flip during remount */
> -		trimming = btrfs_test_opt(fs_info, DISCARD_SYNC);
> +		/*
> +		 * DISCARD can flip during remount. In ZONED mode, we need
> +		 * to reset sequential required zones.
> +		 */
> +		trimming = btrfs_test_opt(fs_info, DISCARD_SYNC) ||
> +				btrfs_is_zoned(fs_info);
>   
>   		/* Implicit trim during transaction commit. */
>   		if (trimming)
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index 5e6b4d1712f2..c134746d7417 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -1331,6 +1331,9 @@ int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
>   
>   		stripe = bbio->stripes;
>   		for (i = 0; i < bbio->num_stripes; i++, stripe++) {
> +			struct btrfs_device *dev = stripe->dev;
> +			u64 physical = stripe->physical;
> +			u64 length = stripe->length;
>   			u64 bytes;
>   			struct request_queue *req_q;
>   
> @@ -1338,14 +1341,18 @@ int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
>   				ASSERT(btrfs_test_opt(fs_info, DEGRADED));
>   				continue;
>   			}
> +
>   			req_q = bdev_get_queue(stripe->dev->bdev);
> -			if (!blk_queue_discard(req_q))
> +			/* zone reset in ZONED mode */
> +			if (btrfs_can_zone_reset(dev, physical, length))
> +				ret = btrfs_reset_device_zone(dev, physical,
> +							      length, &bytes);
> +			else if (blk_queue_discard(req_q))
> +				ret = btrfs_issue_discard(dev->bdev, physical,
> +							  length, &bytes);
> +			else
>   				continue;
>   
> -			ret = btrfs_issue_discard(stripe->dev->bdev,
> -						  stripe->physical,
> -						  stripe->length,
> -						  &bytes);

The problem is you have

if (btrfs_test_opt(fs_info, DISCARD_SYNC))
	ret = btrfs_discard_extent(fs_info, start,
				   end + 1 - start, NULL);

in btrfs_finish_extent_commit, so even if you add support here, you aren't 
actually discarding anything because the transaction commit won't call discard 
for this range.

You're going to have to rework this logic to allow for discard to be called 
everywhere it checks DISCARD_SYNC, but then you also need to go and make sure 
you don't actually allow discards to happen at non-bg aligned ranges.  Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 19/41] btrfs: redirty released extent buffers in ZONED mode
  2020-10-30 13:51   ` [PATCH v9 19/41] btrfs: redirty released extent buffers in ZONED mode Naohiro Aota
@ 2020-11-03 14:41     ` Josef Bacik
  2020-11-06  9:11       ` Johannes Thumshirn
  0 siblings, 1 reply; 119+ messages in thread
From: Josef Bacik @ 2020-11-03 14:41 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> Tree manipulating operations like merging nodes often release
> once-allocated tree nodes. Btrfs cleans such nodes so that pages in the
> node are not uselessly written out. On ZONED volumes, however, such
> optimization blocks the following IOs as the cancellation of the write out
> of the freed blocks breaks the sequential write sequence expected by the
> device.
> 
> This patch introduces a list of clean and unwritten extent buffers that
> have been released in a transaction. Btrfs redirty the buffer so that
> btree_write_cache_pages() can send proper bios to the devices.
> 
> Besides it clears the entire content of the extent buffer not to confuse
> raw block scanners e.g. btrfsck. By clearing the content,
> csum_dirty_buffer() complains about bytenr mismatch, so avoid the checking
> and checksum using newly introduced buffer flag EXTENT_BUFFER_NO_CHECK.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>

This is a lot of work when you could just add

if (btrfs_is_zoned(fs_info))
	return;

to btrfs_clean_tree_block().  The dirty secret is we don't actually unset the 
bits in the transaction io tree because it would require memory allocation 
sometimes, so you don't even need to mess with ->dirty_pages in the first place. 
  The only thing you need is to keep from clearing the EB dirty.  In fact you 
could just do

if (btrfs_is_zoned(fs_info)) {
	memzero_extent_buffer(eb, 0, eb->len);
	set_bit(EXTENT_BUFFER_NO_CHECK, &eb->bflags);
}

to btrfs_clean_tree_block() and then in btrfs_free_tree_block() make sure we 
always pin the extent if we're zoned.  Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 20/41] btrfs: extract page adding function
  2020-10-30 13:51   ` [PATCH v9 20/41] btrfs: extract page adding function Naohiro Aota
@ 2020-11-03 14:45     ` Josef Bacik
  0 siblings, 0 replies; 119+ messages in thread
From: Josef Bacik @ 2020-11-03 14:45 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> This commit extract page adding to bio part from submit_extent_page(). The
> page is added only when bio_flags are the same, contiguous and the added
> page fits in the same stripe as pages in the bio.
> 
> Condition checkings are reordered to allow early return to avoid possibly
> heavy btrfs_bio_fits_in_stripe() calling.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> ---
>   fs/btrfs/extent_io.c | 55 ++++++++++++++++++++++++++++++++------------
>   1 file changed, 40 insertions(+), 15 deletions(-)
> 
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index e91c504fe973..17285048fb5a 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -3012,6 +3012,43 @@ struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size)
>   	return bio;
>   }
>   
> +/**
> + * btrfs_bio_add_page	-	attempt to add a page to bio
> + * @bio:	destination bio
> + * @page:	page to add to the bio
> + * @logical:	offset of the new bio or to check whether we are adding
> + *              a contiguous page to the previous one
> + * @pg_offset:	starting offset in the page
> + * @size:	portion of page that we want to write
> + * @prev_bio_flags:  flags of previous bio to see if we can merge the current one
> + * @bio_flags:	flags of the current bio to see if we can merge them
> + *
> + * Attempt to add a page to bio considering stripe alignment etc. Return
> + * true if successfully page added. Otherwise, return false.
> + */
> +bool btrfs_bio_add_page(struct bio *bio, struct page *page, u64 logical,
> +			unsigned int size, unsigned int pg_offset,
> +			unsigned long prev_bio_flags, unsigned long bio_flags)

This should be static, once you change that you can add

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 21/41] btrfs: use bio_add_zone_append_page for zoned btrfs
  2020-10-30 13:51   ` [PATCH v9 21/41] btrfs: use bio_add_zone_append_page for zoned btrfs Naohiro Aota
@ 2020-11-03 14:55     ` Josef Bacik
  2020-11-10 10:42       ` Naohiro Aota
  0 siblings, 1 reply; 119+ messages in thread
From: Josef Bacik @ 2020-11-03 14:55 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> Zoned device has its own hardware restrictions e.g. max_zone_append_size
> when using REQ_OP_ZONE_APPEND. To follow the restrictions, use
> bio_add_zone_append_page() instead of bio_add_page(). We need target device
> to use bio_add_zone_append_page(), so this commit reads the chunk
> information to memoize the target device to btrfs_io_bio(bio)->device.
> 
> Currently, zoned btrfs only supports SINGLE profile. In the feature,
> btrfs_io_bio can hold extent_map and check the restrictions for all the
> devices the bio will be mapped.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> ---
>   fs/btrfs/extent_io.c | 37 ++++++++++++++++++++++++++++++++++---
>   1 file changed, 34 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index 17285048fb5a..764257eb658f 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -3032,6 +3032,7 @@ bool btrfs_bio_add_page(struct bio *bio, struct page *page, u64 logical,
>   {
>   	sector_t sector = logical >> SECTOR_SHIFT;
>   	bool contig;
> +	int ret;
>   
>   	if (prev_bio_flags != bio_flags)
>   		return false;
> @@ -3046,7 +3047,19 @@ bool btrfs_bio_add_page(struct bio *bio, struct page *page, u64 logical,
>   	if (btrfs_bio_fits_in_stripe(page, size, bio, bio_flags))
>   		return false;
>   
> -	return bio_add_page(bio, page, size, pg_offset) == size;
> +	if (bio_op(bio) == REQ_OP_ZONE_APPEND) {
> +		struct bio orig_bio;
> +
> +		memset(&orig_bio, 0, sizeof(orig_bio));
> +		bio_copy_dev(&orig_bio, bio);
> +		bio_set_dev(bio, btrfs_io_bio(bio)->device->bdev);
> +		ret = bio_add_zone_append_page(bio, page, size, pg_offset);
> +		bio_copy_dev(bio, &orig_bio);

Why do we need this in the first place, since we're only supporting single right 
now?  latest_bdev should be the same, so this serves no purpose, right?

And if it does, we need to figure out another solution, because right now this 
leaks references to the bio->bi_blkg, each copy inc's the refcount on the blkg 
for that bio so we're going to leak blkg's like crazy here.  Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 22/41] btrfs: handle REQ_OP_ZONE_APPEND as writing
  2020-10-30 13:51   ` [PATCH v9 22/41] btrfs: handle REQ_OP_ZONE_APPEND as writing Naohiro Aota
@ 2020-11-03 14:57     ` Josef Bacik
  0 siblings, 0 replies; 119+ messages in thread
From: Josef Bacik @ 2020-11-03 14:57 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> ZONED btrfs uses REQ_OP_ZONE_APPEND bios for writing to actual devices. Let
> btrfs_end_bio() and btrfs_op be aware of it.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 23/41] btrfs: split ordered extent when bio is sent
  2020-10-30 13:51   ` [PATCH v9 23/41] btrfs: split ordered extent when bio is sent Naohiro Aota
@ 2020-11-03 15:29     ` Josef Bacik
  0 siblings, 0 replies; 119+ messages in thread
From: Josef Bacik @ 2020-11-03 15:29 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> For a zone append write, the device decides the location the data is
> written to. Therefore we cannot ensure that two bios are written
> consecutively on the device. In order to ensure that a ordered extent maps
> to a contiguous region on disk, we need to maintain a "one bio == one
> ordered extent" rule.
> 
> This commit implements the splitting of an ordered extent and extent map
> on bio submission to adhere to the rule.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> ---
>   fs/btrfs/inode.c        | 89 +++++++++++++++++++++++++++++++++++++++++
>   fs/btrfs/ordered-data.c | 76 +++++++++++++++++++++++++++++++++++
>   fs/btrfs/ordered-data.h |  2 +
>   3 files changed, 167 insertions(+)
> 
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index 591ca539e444..6b2569dfc3bd 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -2158,6 +2158,86 @@ static blk_status_t btrfs_submit_bio_start(void *private_data, struct bio *bio,
>   	return btrfs_csum_one_bio(BTRFS_I(inode), bio, 0, 0);
>   }
>   
> +int extract_ordered_extent(struct inode *inode, struct bio *bio,
> +			   loff_t file_offset)
> +{
> +	struct btrfs_ordered_extent *ordered;
> +	struct extent_map *em = NULL, *em_new = NULL;
> +	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
> +	u64 start = (u64)bio->bi_iter.bi_sector << SECTOR_SHIFT;
> +	u64 len = bio->bi_iter.bi_size;
> +	u64 end = start + len;
> +	u64 ordered_end;
> +	u64 pre, post;
> +	int ret = 0;
> +
> +	ordered = btrfs_lookup_ordered_extent(BTRFS_I(inode), file_offset);
> +	if (WARN_ON_ONCE(!ordered))
> +		return -EIO;
> +
> +	/* no need to split */
> +	if (ordered->disk_num_bytes == len)
> +		goto out;
> +
> +	/* cannot split once end_bio'd ordered extent */
> +	if (WARN_ON_ONCE(ordered->bytes_left != ordered->disk_num_bytes)) {
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	/* we cannot split compressed ordered extent */
> +	if (WARN_ON_ONCE(ordered->disk_num_bytes != ordered->num_bytes)) {
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	/* cannot split waietd ordered extent */
> +	if (WARN_ON_ONCE(wq_has_sleeper(&ordered->wait))) {
> +		ret = -EINVAL;
> +		goto out;
> +	}

This is bad, we could choose any moment to wait on an ordered extent, and then 
this will break.

In fact I'm not a fan of any of this code.  I assume we only know at 
bio_add_zone_append_page time how much we'll be able to shove into a bio?  Then 
I think the best/cleanest approach here is going to be to add something like 
what compressed does, an entire alternate way to allocate and submit extents.

It would look something like

->lock pages
->reserve space

loop until all pages are submitted
	->build bio
	->add ordered extent for the bio

->unlock pages

Then the ordered extents are their correct size and you don't have to worry 
about arbitrary waiters on ordered extents screwing things up, and you don't 
have to split ordered extents after the fact.  Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 24/41] btrfs: extend btrfs_rmap_block for specifying a device
  2020-10-30 13:51   ` [PATCH v9 24/41] btrfs: extend btrfs_rmap_block for specifying a device Naohiro Aota
@ 2020-11-03 15:32     ` Josef Bacik
  2020-11-06 10:52       ` Johannes Thumshirn
  0 siblings, 1 reply; 119+ messages in thread
From: Josef Bacik @ 2020-11-03 15:32 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> btrfs_rmap_block currently reverse-maps the physical addresses on all
> devices to the corresponding logical addresses.
> 
> This commit extends the function to match to a specified device. The old
> functionality of querying all devices is left intact by specifying NULL as
> target device.
> 
> We pass block_device instead of btrfs_device to __btrfs_rmap_block. This
> function is intended to reverse-map the result of bio, which only have
> block_device.
> 
> This commit also exports the function for later use.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>

Since there's only one caller of btrfs_rmap_block() in this file, and the rest 
are for tests, you might as well just make btrfs_rmap_block() exported with the 
device, and switch the existing callers to use NULL for the device.  Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 25/41] btrfs: use ZONE_APPEND write for ZONED btrfs
  2020-10-30 13:51   ` [PATCH v9 25/41] btrfs: use ZONE_APPEND write for ZONED btrfs Naohiro Aota
@ 2020-11-03 15:55     ` Josef Bacik
  0 siblings, 0 replies; 119+ messages in thread
From: Josef Bacik @ 2020-11-03 15:55 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba
  Cc: hare, linux-fsdevel, Johannes Thumshirn

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> This commit enables zone append writing for zoned btrfs. When using zone
> append, a bio is issued to the start of a target zone and the device
> decides to place it inside the zone. Upon completion the device reports
> the actual written position back to the host.
> 
> Three parts are necessary to enable zone append in btrfs. First, modify
> the bio to use REQ_OP_ZONE_APPEND in btrfs_submit_bio_hook() and adjust
> the bi_sector to point the beginning of the zone.
> 
> Secondly, records the returned physical address (and disk/partno) to the
> ordered extent in end_bio_extent_writepage() after the bio has been
> completed. We cannot resolve the physical address to the logical address
> because we can neither take locks nor allocate a buffer in this end_bio
> context. So, we need to record the physical address to resolve it later in
> btrfs_finish_ordered_io().
> 
> And finally, rewrites the logical addresses of the extent mapping and
> checksum data according to the physical address (using __btrfs_rmap_block).
> If the returned address matches the originally allocated address, we can
> skip this rewriting process.
> 
> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>

I hate this, but I suppose its better than forcing us to wait for ordered 
extents in order of submission, and I can't really think of anything better,

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef


^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 26/41] btrfs: enable zone append writing for direct IO
  2020-10-30 13:51   ` [PATCH v9 26/41] btrfs: enable zone append writing for direct IO Naohiro Aota
@ 2020-11-03 15:56     ` Josef Bacik
  0 siblings, 0 replies; 119+ messages in thread
From: Josef Bacik @ 2020-11-03 15:56 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> Likewise to buffered IO, enable zone append writing for direct IO when its
> used on a zoned block device.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 27/41] btrfs: introduce dedicated data write path for ZONED mode
  2020-10-30 13:51   ` [PATCH v9 27/41] btrfs: introduce dedicated data write path for ZONED mode Naohiro Aota
@ 2020-11-03 15:57     ` Josef Bacik
  0 siblings, 0 replies; 119+ messages in thread
From: Josef Bacik @ 2020-11-03 15:57 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> If more than one IO is issued for one file extent, these IO can be written
> to separate regions on a device. Since we cannot map one file extent to
> such a separate area, we need to follow the "one IO == one ordered extent"
> rule.
> 
> The Normal buffered, uncompressed, not pre-allocated write path (used by
> cow_file_range()) sometimes does not follow this rule. It can write a part
> of an ordered extent when specified a region to write e.g., when its
> called from fdatasync().
> 
> Introduces a dedicated (uncompressed buffered) data write path for ZONED
> mode. This write path will CoW the region and write it at once.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>

This can be modified to work in the way I described in the 'split ordered 
extent' patch, just flesh this out to do all the work together and that way you 
bypass all the ugly splitting stuff.  Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 28/41] btrfs: serialize meta IOs on ZONED mode
  2020-10-30 13:51   ` [PATCH v9 28/41] btrfs: serialize meta IOs on " Naohiro Aota
@ 2020-11-03 16:04     ` Josef Bacik
  0 siblings, 0 replies; 119+ messages in thread
From: Josef Bacik @ 2020-11-03 16:04 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> We cannot use zone append for writing metadata, because the B-tree nodes
> have references to each other using the logical address. Without knowing
> the address in advance, we cannot construct the tree in the first place.
> So we need to serialize write IOs for metadata.
> 
> We cannot add a mutex around allocation and submission because metadata
> blocks are allocated in an earlier stage to build up B-trees.
> 
> Add a zoned_meta_io_lock and hold it during metadata IO submission in
> btree_write_cache_pages() to serialize IOs. Furthermore, this add a
> per-block group metadata IO submission pointer "meta_write_pointer" to
> ensure sequential writing, which can be caused when writing back blocks in
> an unfinished transaction.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> ---
>   fs/btrfs/block-group.h |  1 +
>   fs/btrfs/ctree.h       |  1 +
>   fs/btrfs/disk-io.c     |  1 +
>   fs/btrfs/extent_io.c   | 27 ++++++++++++++++++++++-
>   fs/btrfs/zoned.c       | 50 ++++++++++++++++++++++++++++++++++++++++++
>   fs/btrfs/zoned.h       | 31 ++++++++++++++++++++++++++
>   6 files changed, 110 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
> index 401e9bcefaec..b2a8a3beceac 100644
> --- a/fs/btrfs/block-group.h
> +++ b/fs/btrfs/block-group.h
> @@ -190,6 +190,7 @@ struct btrfs_block_group {
>   	 */
>   	u64 alloc_offset;
>   	u64 zone_unusable;
> +	u64 meta_write_pointer;
>   };
>   
>   static inline u64 btrfs_block_group_end(struct btrfs_block_group *block_group)
> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> index 383c83a1f5b5..736f679f1310 100644
> --- a/fs/btrfs/ctree.h
> +++ b/fs/btrfs/ctree.h
> @@ -955,6 +955,7 @@ struct btrfs_fs_info {
>   	};
>   	/* max size to emit ZONE_APPEND write command */
>   	u64 max_zone_append_size;
> +	struct mutex zoned_meta_io_lock;
>   
>   #ifdef CONFIG_BTRFS_FS_REF_VERIFY
>   	spinlock_t ref_verify_lock;
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index 778716e223ff..f02b121d8213 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -2652,6 +2652,7 @@ void btrfs_init_fs_info(struct btrfs_fs_info *fs_info)
>   	mutex_init(&fs_info->delete_unused_bgs_mutex);
>   	mutex_init(&fs_info->reloc_mutex);
>   	mutex_init(&fs_info->delalloc_root_mutex);
> +	mutex_init(&fs_info->zoned_meta_io_lock);
>   	seqlock_init(&fs_info->profiles_lock);
>   
>   	INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index 3f49febafc69..3cce444d5dbb 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -25,6 +25,7 @@
>   #include "backref.h"
>   #include "disk-io.h"
>   #include "zoned.h"
> +#include "block-group.h"
>   
>   static struct kmem_cache *extent_state_cache;
>   static struct kmem_cache *extent_buffer_cache;
> @@ -4001,6 +4002,7 @@ int btree_write_cache_pages(struct address_space *mapping,
>   				   struct writeback_control *wbc)
>   {
>   	struct extent_buffer *eb, *prev_eb = NULL;
> +	struct btrfs_block_group *cache = NULL;
>   	struct extent_page_data epd = {
>   		.bio = NULL,
>   		.extent_locked = 0,
> @@ -4035,6 +4037,7 @@ int btree_write_cache_pages(struct address_space *mapping,
>   		tag = PAGECACHE_TAG_TOWRITE;
>   	else
>   		tag = PAGECACHE_TAG_DIRTY;
> +	btrfs_zoned_meta_io_lock(fs_info);
>   retry:
>   	if (wbc->sync_mode == WB_SYNC_ALL)
>   		tag_pages_for_writeback(mapping, index, end);
> @@ -4077,12 +4080,30 @@ int btree_write_cache_pages(struct address_space *mapping,
>   			if (!ret)
>   				continue;
>   
> +			if (!btrfs_check_meta_write_pointer(fs_info, eb,
> +							    &cache)) {
> +				/*
> +				 * If for_sync, this hole will be filled with
> +				 * trasnsaction commit.
> +				 */
> +				if (wbc->sync_mode == WB_SYNC_ALL &&
> +				    !wbc->for_sync)
> +					ret = -EAGAIN;
> +				else
> +					ret = 0;
> +				done = 1;
> +				free_extent_buffer(eb);
> +				break;
> +			}
> +
>   			prev_eb = eb;
>   			ret = lock_extent_buffer_for_io(eb, &epd);
>   			if (!ret) {
> +				btrfs_revert_meta_write_pointer(cache, eb);
>   				free_extent_buffer(eb);
>   				continue;
>   			} else if (ret < 0) {
> +				btrfs_revert_meta_write_pointer(cache, eb);
>   				done = 1;
>   				free_extent_buffer(eb);
>   				break;
> @@ -4115,10 +4136,12 @@ int btree_write_cache_pages(struct address_space *mapping,
>   		index = 0;
>   		goto retry;
>   	}
> +	if (cache)
> +		btrfs_put_block_group(cache);
>   	ASSERT(ret <= 0);
>   	if (ret < 0) {
>   		end_write_bio(&epd, ret);
> -		return ret;
> +		goto out;
>   	}
>   	/*
>   	 * If something went wrong, don't allow any metadata write bio to be
> @@ -4153,6 +4176,8 @@ int btree_write_cache_pages(struct address_space *mapping,
>   		ret = -EROFS;
>   		end_write_bio(&epd, ret);
>   	}
> +out:
> +	btrfs_zoned_meta_io_unlock(fs_info);
>   	return ret;
>   }
>   
> diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
> index 50393d560c9a..15bc7d451348 100644
> --- a/fs/btrfs/zoned.c
> +++ b/fs/btrfs/zoned.c
> @@ -989,6 +989,9 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache)
>   		ret = -EIO;
>   	}
>   
> +	if (!ret)
> +		cache->meta_write_pointer = cache->alloc_offset + cache->start;
> +
>   	kfree(alloc_offsets);
>   	free_extent_map(em);
>   
> @@ -1120,3 +1123,50 @@ void btrfs_rewrite_logical_zoned(struct btrfs_ordered_extent *ordered)
>   	kfree(logical);
>   	bdput(bdev);
>   }
> +
> +bool btrfs_check_meta_write_pointer(struct btrfs_fs_info *fs_info,
> +				    struct extent_buffer *eb,
> +				    struct btrfs_block_group **cache_ret)
> +{
> +	struct btrfs_block_group *cache;
> +
> +	if (!btrfs_is_zoned(fs_info))
> +		return true;
> +
> +	cache = *cache_ret;
> +
> +	if (cache && (eb->start < cache->start ||
> +		      cache->start + cache->length <= eb->start)) {
> +		btrfs_put_block_group(cache);
> +		cache = NULL;
> +		*cache_ret = NULL;
> +	}
> +
> +	if (!cache)
> +		cache = btrfs_lookup_block_group(fs_info, eb->start);
> +
> +	if (cache) {
> +		*cache_ret = cache;

Don't set this here, set it after the if statement.

> +
> +		if (cache->meta_write_pointer != eb->start) {
> +			btrfs_put_block_group(cache);
> +			cache = NULL;
> +			*cache_ret = NULL;

And delete these two lines.  Then you can add

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 30/41] btrfs: avoid async metadata checksum on ZONED mode
  2020-10-30 13:51   ` [PATCH v9 30/41] btrfs: avoid async metadata checksum on ZONED mode Naohiro Aota
@ 2020-11-03 16:05     ` Josef Bacik
  0 siblings, 0 replies; 119+ messages in thread
From: Josef Bacik @ 2020-11-03 16:05 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> In ZONED, btrfs uses per-FS zoned_meta_io_lock to serialize the metadata
> write IOs.
> 
> Even with these serialization, write bios sent from btree_write_cache_pages
> can be reordered by async checksum workers as these workers are per CPU and
> not per zone.
> 
> To preserve write BIO ordering, we can disable async metadata checksum on
> ZONED.  This does not result in lower performance with HDDs as a single CPU
> core is fast enough to do checksum for a single zone write stream with the
> maximum possible bandwidth of the device. If multiple zones are being
> written simultaneously, HDD seek overhead lowers the achievable maximum
> bandwidth, resulting again in a per zone checksum serialization not
> affecting performance.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 31/41] btrfs: mark block groups to copy for device-replace
  2020-10-30 13:51   ` [PATCH v9 31/41] btrfs: mark block groups to copy for device-replace Naohiro Aota
@ 2020-11-03 17:09     ` Josef Bacik
  0 siblings, 0 replies; 119+ messages in thread
From: Josef Bacik @ 2020-11-03 17:09 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> This is the 1/4 patch to support device-replace in ZONED mode.
> 
> We have two types of I/Os during the device-replace process. One is an I/O
> to "copy" (by the scrub functions) all the device extents on the source
> device to the destination device.  The other one is an I/O to "clone" (by
> handle_ops_on_dev_replace()) new incoming write I/Os from users to the
> source device into the target device.
> 
> Cloning incoming I/Os can break the sequential write rule in the target
> device. When writing is mapped in the middle of a block group, the I/O is
> directed in the middle of a target device zone, which breaks the sequential
> write rule.
> 
> However, the cloning function cannot be merely disabled since incoming I/Os
> targeting already copied device extents must be cloned so that the I/O is
> executed on the target device.
> 
> We cannot use dev_replace->cursor_{left,right} to determine whether bio is
> going to not yet copied region.  Since we have a time gap between finishing
> btrfs_scrub_dev() and rewriting the mapping tree in
> btrfs_dev_replace_finishing(), we can have a newly allocated device extent
> which is never cloned nor copied.
> 
> So the point is to copy only already existing device extents. This patch
> introduces mark_block_group_to_copy() to mark existing block groups as a
> target of copying. Then, handle_ops_on_dev_replace() and dev-replace can
> check the flag to do their job.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> ---
>   fs/btrfs/block-group.h |   1 +
>   fs/btrfs/dev-replace.c | 175 +++++++++++++++++++++++++++++++++++++++++
>   fs/btrfs/dev-replace.h |   3 +
>   fs/btrfs/scrub.c       |  17 ++++
>   4 files changed, 196 insertions(+)
> 
> diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
> index b2a8a3beceac..e91123495d68 100644
> --- a/fs/btrfs/block-group.h
> +++ b/fs/btrfs/block-group.h
> @@ -95,6 +95,7 @@ struct btrfs_block_group {
>   	unsigned int iref:1;
>   	unsigned int has_caching_ctl:1;
>   	unsigned int removed:1;
> +	unsigned int to_copy:1;
>   
>   	int disk_cache_state;
>   
> diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
> index 5e3554482af1..e86aff38aea4 100644
> --- a/fs/btrfs/dev-replace.c
> +++ b/fs/btrfs/dev-replace.c
> @@ -22,6 +22,7 @@
>   #include "dev-replace.h"
>   #include "sysfs.h"
>   #include "zoned.h"
> +#include "block-group.h"
>   
>   /*
>    * Device replace overview
> @@ -437,6 +438,176 @@ static char* btrfs_dev_name(struct btrfs_device *device)
>   		return rcu_str_deref(device->name);
>   }
>   
> +static int mark_block_group_to_copy(struct btrfs_fs_info *fs_info,
> +				    struct btrfs_device *src_dev)
> +{
> +	struct btrfs_path *path;
> +	struct btrfs_key key;
> +	struct btrfs_key found_key;
> +	struct btrfs_root *root = fs_info->dev_root;
> +	struct btrfs_dev_extent *dev_extent = NULL;
> +	struct btrfs_block_group *cache;
> +	struct extent_buffer *l;
> +	struct btrfs_trans_handle *trans;
> +	int slot;
> +	int ret = 0;
> +	u64 chunk_offset, length;
> +
> +	/* Do not use "to_copy" on non-ZONED for now */
> +	if (!btrfs_fs_incompat(fs_info, ZONED))
> +		return 0;

if (!btrfs_is_zoned())

> +
> +	mutex_lock(&fs_info->chunk_mutex);
> +
> +	/* ensulre we don't have pending new block group */

ensure.

> +	while (fs_info->running_transaction &&
> +	       !list_empty(&fs_info->running_transaction->dev_update_list)) {

This is not safe to check, running_transaction can change without the trans_lock 
held.

> +		mutex_unlock(&fs_info->chunk_mutex);
> +		trans = btrfs_attach_transaction(root);
> +		if (IS_ERR(trans)) {
> +			ret = PTR_ERR(trans);
> +			mutex_lock(&fs_info->chunk_mutex);
> +			if (ret == -ENOENT)
> +				continue;
> +			else
> +				goto out;
> +		}
> +
> +		ret = btrfs_commit_transaction(trans);
> +		mutex_lock(&fs_info->chunk_mutex);
> +		if (ret)
> +			goto out;
> +	}
> +
> +	path = btrfs_alloc_path();
> +	if (!path) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +
> +	path->reada = READA_FORWARD;
> +	path->search_commit_root = 1;
> +	path->skip_locking = 1;
> +
> +	key.objectid = src_dev->devid;
> +	key.offset = 0ull;

0 is fine here right?

> +	key.type = BTRFS_DEV_EXTENT_KEY;
> +
> +	while (1) {
> +		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
> +		if (ret < 0)
> +			break;
> +		if (ret > 0) {
> +			if (path->slots[0] >=
> +			    btrfs_header_nritems(path->nodes[0])) {
> +				ret = btrfs_next_leaf(root, path);
> +				if (ret < 0)
> +					break;
> +				if (ret > 0) {
> +					ret = 0;
> +					break;
> +				}
> +			} else {
> +				ret = 0;
> +			}
> +		}
> +
> +		l = path->nodes[0];
> +		slot = path->slots[0];
> +
> +		btrfs_item_key_to_cpu(l, &found_key, slot);
> +
> +		if (found_key.objectid != src_dev->devid)
> +			break;
> +
> +		if (found_key.type != BTRFS_DEV_EXTENT_KEY)
> +			break;
> +
> +		if (found_key.offset < key.offset)
> +			break;
> +
> +		dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
> +		length = btrfs_dev_extent_length(l, dev_extent);
> +
> +		chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
> +
> +		cache = btrfs_lookup_block_group(fs_info, chunk_offset);
> +		if (!cache)
> +			goto skip;
> +
> +		spin_lock(&cache->lock);
> +		cache->to_copy = 1;
> +		spin_unlock(&cache->lock);
> +
> +		btrfs_put_block_group(cache);
> +
> +skip:
> +		key.offset = found_key.offset + length;
> +		btrfs_release_path(path);

Why are you releasing the path here?

This can be re-arranged into a loop that just uses btrfs_next_item().


> +	}
> +
> +	btrfs_free_path(path);
> +out:
> +	mutex_unlock(&fs_info->chunk_mutex);
> +
> +	return ret;
> +}
> +
> +bool btrfs_finish_block_group_to_copy(struct btrfs_device *srcdev,
> +				      struct btrfs_block_group *cache,
> +				      u64 physical)
> +{
> +	struct btrfs_fs_info *fs_info = cache->fs_info;
> +	struct extent_map *em;
> +	struct map_lookup *map;
> +	u64 chunk_offset = cache->start;
> +	int num_extents, cur_extent;
> +	int i;
> +
> +	/* Do not use "to_copy" on non-ZONED for now */
> +	if (!btrfs_fs_incompat(fs_info, ZONED))
> +		return true;

btrfs_is_zoned();

> +
> +	spin_lock(&cache->lock);
> +	if (cache->removed) {
> +		spin_unlock(&cache->lock);
> +		return true;
> +	}
> +	spin_unlock(&cache->lock);
> +
> +	em = btrfs_get_chunk_map(fs_info, chunk_offset, 1);
> +	BUG_ON(IS_ERR(em));

ASSERT(!IS_ERR(em));

> +	map = em->map_lookup;
> +
> +	num_extents = cur_extent = 0;
> +	for (i = 0; i < map->num_stripes; i++) {
> +		/* we have more device extent to copy */
> +		if (srcdev != map->stripes[i].dev)
> +			continue;
> +
> +		num_extents++;
> +		if (physical == map->stripes[i].physical)
> +			cur_extent = i;
> +	}
> +
> +	free_extent_map(em);
> +
> +	if (num_extents > 1 && cur_extent < num_extents - 1) {
> +		/*
> +		 * Has more stripes on this device. Keep this BG
> +		 * readonly until we finish all the stripes.
> +		 */
> +		return false;
> +	}
> +
> +	/* last stripe on this device */
> +	spin_lock(&cache->lock);
> +	cache->to_copy = 0;
> +	spin_unlock(&cache->lock);
> +
> +	return true;
> +}
> +
>   static int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info,
>   		const char *tgtdev_name, u64 srcdevid, const char *srcdev_name,
>   		int read_src)
> @@ -478,6 +649,10 @@ static int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info,
>   	if (ret)
>   		return ret;
>   
> +	ret = mark_block_group_to_copy(fs_info, src_device);
> +	if (ret)
> +		return ret;
> +
>   	down_write(&dev_replace->rwsem);
>   	switch (dev_replace->replace_state) {
>   	case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
> diff --git a/fs/btrfs/dev-replace.h b/fs/btrfs/dev-replace.h
> index 60b70dacc299..3911049a5f23 100644
> --- a/fs/btrfs/dev-replace.h
> +++ b/fs/btrfs/dev-replace.h
> @@ -18,5 +18,8 @@ int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info);
>   void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info);
>   int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info);
>   int __pure btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace);
> +bool btrfs_finish_block_group_to_copy(struct btrfs_device *srcdev,
> +				      struct btrfs_block_group *cache,
> +				      u64 physical);
>   
>   #endif
> diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
> index aa1b36cf5c88..d0d7db3c8b0b 100644
> --- a/fs/btrfs/scrub.c
> +++ b/fs/btrfs/scrub.c
> @@ -3500,6 +3500,17 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx,
>   		if (!cache)
>   			goto skip;
>   
> +
> +		if (sctx->is_dev_replace && btrfs_fs_incompat(fs_info, ZONED)) {

btrfs_is_zoned().  Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 32/41] btrfs: implement cloning for ZONED device-replace
  2020-10-30 13:51   ` [PATCH v9 32/41] btrfs: implement cloning for ZONED device-replace Naohiro Aota
@ 2020-11-03 17:15     ` Josef Bacik
  0 siblings, 0 replies; 119+ messages in thread
From: Josef Bacik @ 2020-11-03 17:15 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> This is 2/4 patch to implement device-replace for ZONED mode.
> 
> On zoned mode, a block group must be either copied (from the source device
> to the destination device) or cloned (to the both device).
> 
> This commit implements the cloning part. If a block group targeted by an IO
> is marked to copy, we should not clone the IO to the destination device,
> because the block group is eventually copied by the replace process.
> 
> This commit also handles cloning of device reset.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> ---
>   fs/btrfs/dev-replace.c |  4 ++--
>   fs/btrfs/extent-tree.c | 20 ++++++++++++++++++--
>   fs/btrfs/scrub.c       |  2 +-
>   fs/btrfs/volumes.c     | 33 +++++++++++++++++++++++++++++++--
>   fs/btrfs/zoned.c       | 11 +++++++++++
>   5 files changed, 63 insertions(+), 7 deletions(-)
> 
> diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
> index e86aff38aea4..848f8063dc1c 100644
> --- a/fs/btrfs/dev-replace.c
> +++ b/fs/btrfs/dev-replace.c
> @@ -454,7 +454,7 @@ static int mark_block_group_to_copy(struct btrfs_fs_info *fs_info,
>   	u64 chunk_offset, length;
>   
>   	/* Do not use "to_copy" on non-ZONED for now */
> -	if (!btrfs_fs_incompat(fs_info, ZONED))
> +	if (!btrfs_is_zoned(fs_info))
>   		return 0;
>   
>   	mutex_lock(&fs_info->chunk_mutex);
> @@ -565,7 +565,7 @@ bool btrfs_finish_block_group_to_copy(struct btrfs_device *srcdev,
>   	int i;
>   
>   	/* Do not use "to_copy" on non-ZONED for now */
> -	if (!btrfs_fs_incompat(fs_info, ZONED))
> +	if (!btrfs_is_zoned(fs_info))
>   		return true;
>   

Heh these
>   	spin_lock(&cache->lock);
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index 57454ef4c91e..1bb95d5aaed2 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -35,6 +35,7 @@
>   #include "discard.h"
>   #include "rcu-string.h"
>   #include "zoned.h"
> +#include "dev-replace.h"
>   
>   #undef SCRAMBLE_DELAYED_REFS
>   
> @@ -1336,6 +1337,8 @@ int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
>   			u64 length = stripe->length;
>   			u64 bytes;
>   			struct request_queue *req_q;
> +			struct btrfs_dev_replace *dev_replace =
> +				&fs_info->dev_replace;
>   
>   			if (!stripe->dev->bdev) {
>   				ASSERT(btrfs_test_opt(fs_info, DEGRADED));
> @@ -1344,15 +1347,28 @@ int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
>   
>   			req_q = bdev_get_queue(stripe->dev->bdev);
>   			/* zone reset in ZONED mode */
> -			if (btrfs_can_zone_reset(dev, physical, length))
> +			if (btrfs_can_zone_reset(dev, physical, length)) {
>   				ret = btrfs_reset_device_zone(dev, physical,
>   							      length, &bytes);
> -			else if (blk_queue_discard(req_q))
> +				if (ret)
> +					goto next;
> +				if (!btrfs_dev_replace_is_ongoing(
> +					    dev_replace) ||
> +				    dev != dev_replace->srcdev)
> +					goto next;
> +
> +				discarded_bytes += bytes;
> +				/* send to replace target as well */
> +				ret = btrfs_reset_device_zone(
> +					dev_replace->tgtdev,
> +					physical, length, &bytes);
> +			} else if (blk_queue_discard(req_q))

And this needs to go into a helper, because lord it's not pretty.  Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 33/41] btrfs: implement copying for ZONED device-replace
  2020-10-30 13:51   ` [PATCH v9 33/41] btrfs: implement copying " Naohiro Aota
@ 2020-11-03 17:19     ` Josef Bacik
  2020-11-10 11:09       ` Naohiro Aota
  0 siblings, 1 reply; 119+ messages in thread
From: Josef Bacik @ 2020-11-03 17:19 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> This is 3/4 patch to implement device-replace on ZONED mode.
> 
> This commit implement copying. So, it track the write pointer during device
> replace process. Device-replace's copying is smart to copy only used
> extents on source device, we have to fill the gap to honor the sequential
> write rule in the target device.
> 
> Device-replace process in ZONED mode must copy or clone all the extents in
> the source device exactly once.  So, we need to use to ensure allocations
> started just before the dev-replace process to have their corresponding
> extent information in the B-trees. finish_extent_writes_for_zoned()
> implements that functionality, which basically is the removed code in the
> commit 042528f8d840 ("Btrfs: fix block group remaining RO forever after
> error during device replace").
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> ---
>   fs/btrfs/scrub.c | 86 ++++++++++++++++++++++++++++++++++++++++++++++++
>   fs/btrfs/zoned.c | 12 +++++++
>   fs/btrfs/zoned.h |  7 ++++
>   3 files changed, 105 insertions(+)
> 
> diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
> index 371bb6437cab..aaf7882dee06 100644
> --- a/fs/btrfs/scrub.c
> +++ b/fs/btrfs/scrub.c
> @@ -169,6 +169,7 @@ struct scrub_ctx {
>   	int			pages_per_rd_bio;
>   
>   	int			is_dev_replace;
> +	u64			write_pointer;
>   
>   	struct scrub_bio        *wr_curr_bio;
>   	struct mutex            wr_lock;
> @@ -1623,6 +1624,25 @@ static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
>   	return scrub_add_page_to_wr_bio(sblock->sctx, spage);
>   }
>   
> +static int fill_writer_pointer_gap(struct scrub_ctx *sctx, u64 physical)
> +{
> +	int ret = 0;
> +	u64 length;
> +
> +	if (!btrfs_is_zoned(sctx->fs_info))
> +		return 0;
> +
> +	if (sctx->write_pointer < physical) {
> +		length = physical - sctx->write_pointer;
> +
> +		ret = btrfs_zoned_issue_zeroout(sctx->wr_tgtdev,
> +						sctx->write_pointer, length);
> +		if (!ret)
> +			sctx->write_pointer = physical;
> +	}
> +	return ret;
> +}
> +
>   static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
>   				    struct scrub_page *spage)
>   {
> @@ -1645,6 +1665,13 @@ static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
>   	if (sbio->page_count == 0) {
>   		struct bio *bio;
>   
> +		ret = fill_writer_pointer_gap(sctx,
> +					      spage->physical_for_dev_replace);
> +		if (ret) {
> +			mutex_unlock(&sctx->wr_lock);
> +			return ret;
> +		}
> +
>   		sbio->physical = spage->physical_for_dev_replace;
>   		sbio->logical = spage->logical;
>   		sbio->dev = sctx->wr_tgtdev;
> @@ -1706,6 +1733,10 @@ static void scrub_wr_submit(struct scrub_ctx *sctx)
>   	 * doubled the write performance on spinning disks when measured
>   	 * with Linux 3.5 */
>   	btrfsic_submit_bio(sbio->bio);
> +
> +	if (btrfs_is_zoned(sctx->fs_info))
> +		sctx->write_pointer = sbio->physical +
> +			sbio->page_count * PAGE_SIZE;
>   }
>   
>   static void scrub_wr_bio_end_io(struct bio *bio)
> @@ -2973,6 +3004,21 @@ static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
>   	return ret < 0 ? ret : 0;
>   }
>   
> +static void sync_replace_for_zoned(struct scrub_ctx *sctx)
> +{
> +	if (!btrfs_is_zoned(sctx->fs_info))
> +		return;
> +
> +	sctx->flush_all_writes = true;
> +	scrub_submit(sctx);
> +	mutex_lock(&sctx->wr_lock);
> +	scrub_wr_submit(sctx);
> +	mutex_unlock(&sctx->wr_lock);
> +
> +	wait_event(sctx->list_wait,
> +		   atomic_read(&sctx->bios_in_flight) == 0);
> +}
> +
>   static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
>   					   struct map_lookup *map,
>   					   struct btrfs_device *scrub_dev,
> @@ -3105,6 +3151,14 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
>   	 */
>   	blk_start_plug(&plug);
>   
> +	if (sctx->is_dev_replace &&
> +	    btrfs_dev_is_sequential(sctx->wr_tgtdev, physical)) {
> +		mutex_lock(&sctx->wr_lock);
> +		sctx->write_pointer = physical;
> +		mutex_unlock(&sctx->wr_lock);
> +		sctx->flush_all_writes = true;
> +	}
> +
>   	/*
>   	 * now find all extents for each stripe and scrub them
>   	 */
> @@ -3292,6 +3346,9 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
>   			if (ret)
>   				goto out;
>   
> +			if (sctx->is_dev_replace)
> +				sync_replace_for_zoned(sctx);
> +
>   			if (extent_logical + extent_len <
>   			    key.objectid + bytes) {
>   				if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
> @@ -3414,6 +3471,25 @@ static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
>   	return ret;
>   }
>   
> +static int finish_extent_writes_for_zoned(struct btrfs_root *root,
> +					  struct btrfs_block_group *cache)
> +{
> +	struct btrfs_fs_info *fs_info = cache->fs_info;
> +	struct btrfs_trans_handle *trans;
> +
> +	if (!btrfs_is_zoned(fs_info))
> +		return 0;
> +
> +	btrfs_wait_block_group_reservations(cache);
> +	btrfs_wait_nocow_writers(cache);
> +	btrfs_wait_ordered_roots(fs_info, U64_MAX, cache->start, cache->length);
> +
> +	trans = btrfs_join_transaction(root);
> +	if (IS_ERR(trans))
> +		return PTR_ERR(trans);
> +	return btrfs_commit_transaction(trans);
> +}
> +
>   static noinline_for_stack
>   int scrub_enumerate_chunks(struct scrub_ctx *sctx,
>   			   struct btrfs_device *scrub_dev, u64 start, u64 end)
> @@ -3569,6 +3645,16 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx,
>   		 * group is not RO.
>   		 */
>   		ret = btrfs_inc_block_group_ro(cache, sctx->is_dev_replace);
> +		if (!ret && sctx->is_dev_replace) {
> +			ret = finish_extent_writes_for_zoned(root, cache);
> +			if (ret) {
> +				btrfs_dec_block_group_ro(cache);
> +				scrub_pause_off(fs_info);
> +				btrfs_put_block_group(cache);
> +				break;
> +			}
> +		}
> +
>   		if (ret == 0) {
>   			ro_set = 1;
>   		} else if (ret == -ENOSPC && !sctx->is_dev_replace) {
> diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
> index f672465d1bb1..1b080184440d 100644
> --- a/fs/btrfs/zoned.c
> +++ b/fs/btrfs/zoned.c
> @@ -1181,3 +1181,15 @@ void btrfs_revert_meta_write_pointer(struct btrfs_block_group *cache,
>   	ASSERT(cache->meta_write_pointer == eb->start + eb->len);
>   	cache->meta_write_pointer = eb->start;
>   }
> +
> +int btrfs_zoned_issue_zeroout(struct btrfs_device *device, u64 physical,
> +			      u64 length)
> +{
> +	if (!btrfs_dev_is_sequential(device, physical))
> +		return -EOPNOTSUPP;
> +

This is going to result in a bunch of scrub errors.  Is this unlikely to happen? 
  And if it isn't, should we do something different?  If it's not sequential 
then we can probably just write to whatever offset we want right?  So do we need 
an error here at all?  Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 34/41] btrfs: support dev-replace in ZONED mode
  2020-10-30 13:51   ` [PATCH v9 34/41] btrfs: support dev-replace in ZONED mode Naohiro Aota
@ 2020-11-03 20:34     ` Josef Bacik
  0 siblings, 0 replies; 119+ messages in thread
From: Josef Bacik @ 2020-11-03 20:34 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> This is 4/4 patch to implement device-replace on ZONED mode.
> 
> Even after the copying is done, the write pointers of the source device and
> the destination device may not be synchronized. For example, when the last
> allocated extent is freed before device-replace process, the extent is not
> copied, leaving a hole there.
> 
> This patch synchronize the write pointers by writing zeros to the
> destination device.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 35/41] btrfs: enable relocation in ZONED mode
  2020-10-30 13:51   ` [PATCH v9 35/41] btrfs: enable relocation " Naohiro Aota
@ 2020-11-03 20:39     ` Josef Bacik
  0 siblings, 0 replies; 119+ messages in thread
From: Josef Bacik @ 2020-11-03 20:39 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> To serialize allocation and submit_bio, we introduced mutex around them. As
> a result, preallocation must be completely disabled to avoid a deadlock.
> 
> Since current relocation process relies on preallocation to move file data
> extents, it must be handled in another way. In ZONED mode, we just truncate
> the inode to the size that we wanted to pre-allocate. Then, we flush dirty
> pages on the file before finishing relocation process.
> run_delalloc_zoned() will handle all the allocation and submit IOs to the
> underlying layers.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> ---
>   fs/btrfs/relocation.c | 35 +++++++++++++++++++++++++++++++++--
>   1 file changed, 33 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
> index 3602806d71bd..44b697b881b6 100644
> --- a/fs/btrfs/relocation.c
> +++ b/fs/btrfs/relocation.c
> @@ -2603,6 +2603,32 @@ static noinline_for_stack int prealloc_file_extent_cluster(
>   	if (ret)
>   		return ret;
>   
> +	/*
> +	 * In ZONED mode, we cannot preallocate the file region. Instead, we
> +	 * dirty and fiemap_write the region.
> +	 */
> +
> +	if (btrfs_is_zoned(inode->root->fs_info)) {
> +		struct btrfs_root *root = inode->root;
> +		struct btrfs_trans_handle *trans;
> +
> +		end = cluster->end - offset + 1;
> +		trans = btrfs_start_transaction(root, 1);
> +		if (IS_ERR(trans))
> +			return PTR_ERR(trans);
> +
> +		inode->vfs_inode.i_ctime = current_time(&inode->vfs_inode);
> +		i_size_write(&inode->vfs_inode, end);
> +		ret = btrfs_update_inode(trans, root, &inode->vfs_inode);
> +		if (ret) {
> +			btrfs_abort_transaction(trans, ret);
> +			btrfs_end_transaction(trans);
> +			return ret;
> +		}
> +
> +		return btrfs_end_transaction(trans);
> +	}

The reason we pre-allocate is because we need the extents to be exactly how long 
they are on disk.  If we have a 123mib extent, we need the extent it goes into 
to be exactly 123mib, otherwise we cannot simply relocate out its location. 
This doesn't do anything for us.  I'm not even sure we can do relocation for 
zoned since we have to maintain the original extent size, but if you can then 
it's going to be more complicated than just this.  You'll have to either forgo 
WRITE_APPEND for this case, or make sure you can actually write the whole 
ordered extent in one go.  Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 37/41] btrfs: split alloc_log_tree()
  2020-10-30 13:51   ` [PATCH v9 37/41] btrfs: split alloc_log_tree() Naohiro Aota
@ 2020-11-03 20:42     ` Josef Bacik
  2020-11-03 22:10       ` Amy Parker
  0 siblings, 1 reply; 119+ messages in thread
From: Josef Bacik @ 2020-11-03 20:42 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba
  Cc: hare, linux-fsdevel, Johannes Thumshirn

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> This is a preparation for the next patch. This commit split
> alloc_log_tree() to allocating tree structure part (remains in
> alloc_log_tree()) and allocating tree node part (moved in
> btrfs_alloc_log_tree_node()). The latter part is also exported to be used
> in the next patch.
> 
> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> ---
>   fs/btrfs/disk-io.c | 31 +++++++++++++++++++++++++------
>   fs/btrfs/disk-io.h |  2 ++
>   2 files changed, 27 insertions(+), 6 deletions(-)
> 
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index 2b30ef8a7034..70885f3d3321 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -1211,7 +1211,6 @@ static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
>   					 struct btrfs_fs_info *fs_info)
>   {
>   	struct btrfs_root *root;
> -	struct extent_buffer *leaf;
>   
>   	root = btrfs_alloc_root(fs_info, BTRFS_TREE_LOG_OBJECTID, GFP_NOFS);
>   	if (!root)
> @@ -1221,6 +1220,14 @@ static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
>   	root->root_key.type = BTRFS_ROOT_ITEM_KEY;
>   	root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
>   
> +	return root;
> +}
> +
> +int btrfs_alloc_log_tree_node(struct btrfs_trans_handle *trans,
> +			      struct btrfs_root *root)
> +{
> +	struct extent_buffer *leaf;
> +
>   	/*
>   	 * DON'T set SHAREABLE bit for log trees.
>   	 *
> @@ -1233,26 +1240,31 @@ static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
>   
>   	leaf = btrfs_alloc_tree_block(trans, root, 0, BTRFS_TREE_LOG_OBJECTID,
>   			NULL, 0, 0, 0, BTRFS_NESTING_NORMAL);
> -	if (IS_ERR(leaf)) {
> -		btrfs_put_root(root);
> -		return ERR_CAST(leaf);
> -	}
> +	if (IS_ERR(leaf))
> +		return PTR_ERR(leaf);
>   
>   	root->node = leaf;
>   
>   	btrfs_mark_buffer_dirty(root->node);
>   	btrfs_tree_unlock(root->node);
> -	return root;
> +
> +	return 0;
>   }
>   
>   int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
>   			     struct btrfs_fs_info *fs_info)
>   {
>   	struct btrfs_root *log_root;
> +	int ret;
>   
>   	log_root = alloc_log_tree(trans, fs_info);
>   	if (IS_ERR(log_root))

newline.

>   		return PTR_ERR(log_root);
> +	ret = btrfs_alloc_log_tree_node(trans, log_root);
> +	if (ret) {
> +		kfree(log_root);

btrfs_put_root(log_root);

> +		return ret;
> +	}

newline.  Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 38/41] btrfs: extend zoned allocator to use dedicated tree-log block group
  2020-10-30 13:51   ` [PATCH v9 38/41] btrfs: extend zoned allocator to use dedicated tree-log block group Naohiro Aota
@ 2020-11-03 20:47     ` Josef Bacik
  2020-11-10  6:37       ` Naohiro Aota
  0 siblings, 1 reply; 119+ messages in thread
From: Josef Bacik @ 2020-11-03 20:47 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba
  Cc: hare, linux-fsdevel, Johannes Thumshirn

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> This is the 1/3 patch to enable tree log on ZONED mode.
> 
> The tree-log feature does not work on ZONED mode as is. Blocks for a
> tree-log tree are allocated mixed with other metadata blocks, and btrfs
> writes and syncs the tree-log blocks to devices at the time of fsync(),
> which is different timing from a global transaction commit. As a result,
> both writing tree-log blocks and writing other metadata blocks become
> non-sequential writes that ZONED mode must avoid.
> 
> We can introduce a dedicated block group for tree-log blocks so that
> tree-log blocks and other metadata blocks can be separated write streams.
> As a result, each write stream can now be written to devices separately.
> "fs_info->treelog_bg" tracks the dedicated block group and btrfs assign
> "treelog_bg" on-demand on tree-log block allocation time.
> 
> This commit extends the zoned block allocator to use the block group.
> 
> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>

If you're going to remove an entire block group from being allowed to be used 
for metadata you are going to need to account for it in the space_info, 
otherwise we're going to end up with nasty ENOSPC corners here.

But this begs the question, do we want the tree log for zoned?  We could just 
commit the transaction and call it good enough.  We lose performance, but zoned 
isn't necessarily about performance.

If we do then at a minimum we're going to need to remove this block group from 
the space info counters for metadata.  Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 39/41] btrfs: serialize log transaction on ZONED mode
  2020-10-30 13:51   ` [PATCH v9 39/41] btrfs: serialize log transaction on ZONED mode Naohiro Aota
@ 2020-11-03 20:49     ` Josef Bacik
  0 siblings, 0 replies; 119+ messages in thread
From: Josef Bacik @ 2020-11-03 20:49 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> This is the 2/3 patch to enable tree-log on ZONED mode.
> 
> Since we can start more than one log transactions per subvolume
> simultaneously, nodes from multiple transactions can be allocated
> interleaved. Such mixed allocation results in non-sequential writes at the
> time of log transaction commit. The nodes of the global log root tree
> (fs_info->log_root_tree), also have the same mixed allocation problem.
> 
> This patch serializes log transactions by waiting for a committing
> transaction when someone tries to start a new transaction, to avoid the
> mixed allocation problem. We must also wait for running log transactions
> from another subvolume, but there is no easy way to detect which subvolume
> root is running a log transaction. So, this patch forbids starting a new
> log transaction when other subvolumes already allocated the global log root
> tree.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>

This restriction makes the tree log really, really seem not worth it for zoned. 
  I'd rig up a fio test that does fsyncs into multiple subvolumes and tests this 
vs just committing the transaction.  If committing the transaction is better, 
just skip the log altogether for zoned.  Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 40/41] btrfs: reorder log node allocation
  2020-10-30 13:51   ` [PATCH v9 40/41] btrfs: reorder log node allocation Naohiro Aota
@ 2020-11-03 20:49     ` Josef Bacik
  0 siblings, 0 replies; 119+ messages in thread
From: Josef Bacik @ 2020-11-03 20:49 UTC (permalink / raw)
  To: Naohiro Aota, linux-btrfs, dsterba
  Cc: hare, linux-fsdevel, Johannes Thumshirn

On 10/30/20 9:51 AM, Naohiro Aota wrote:
> This is the 3/3 patch to enable tree-log on ZONED mode.
> 
> The allocation order of nodes of "fs_info->log_root_tree" and nodes of
> "root->log_root" is not the same as the writing order of them. So, the
> writing causes unaligned write errors.
> 
> This patch reorders the allocation of them by delaying allocation of the
> root node of "fs_info->log_root_tree," so that the node buffers can go out
> sequentially to devices.
> 
> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>

If you keep the tree log stuff, you can add

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 37/41] btrfs: split alloc_log_tree()
  2020-11-03 20:42     ` Josef Bacik
@ 2020-11-03 22:10       ` Amy Parker
  2020-11-10 11:12         ` Naohiro Aota
  0 siblings, 1 reply; 119+ messages in thread
From: Amy Parker @ 2020-11-03 22:10 UTC (permalink / raw)
  To: Josef Bacik
  Cc: Naohiro Aota, linux-btrfs, David Sterba, hare, linux-fsdevel,
	Johannes Thumshirn

On Tue, Nov 3, 2020 at 2:06 PM Josef Bacik <josef@toxicpanda.com> wrote:
>
> On 10/30/20 9:51 AM, Naohiro Aota wrote:
> > This is a preparation for the next patch. This commit split
> > alloc_log_tree() to allocating tree structure part (remains in
> > alloc_log_tree()) and allocating tree node part (moved in
> > btrfs_alloc_log_tree_node()). The latter part is also exported to be used
> > in the next patch.
> >
> > Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
> > Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> > ---
> >   fs/btrfs/disk-io.c | 31 +++++++++++++++++++++++++------
> >   fs/btrfs/disk-io.h |  2 ++
> >   2 files changed, 27 insertions(+), 6 deletions(-)
> >
> > diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> > index 2b30ef8a7034..70885f3d3321 100644
> > --- a/fs/btrfs/disk-io.c
> > +++ b/fs/btrfs/disk-io.c
> > @@ -1211,7 +1211,6 @@ static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
> >                                        struct btrfs_fs_info *fs_info)
> >   {
> >       struct btrfs_root *root;
> > -     struct extent_buffer *leaf;
> >
> >       root = btrfs_alloc_root(fs_info, BTRFS_TREE_LOG_OBJECTID, GFP_NOFS);
> >       if (!root)
> > @@ -1221,6 +1220,14 @@ static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
> >       root->root_key.type = BTRFS_ROOT_ITEM_KEY;
> >       root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
> >
> > +     return root;
> > +}
> > +
> > +int btrfs_alloc_log_tree_node(struct btrfs_trans_handle *trans,
> > +                           struct btrfs_root *root)
> > +{
> > +     struct extent_buffer *leaf;
> > +
> >       /*
> >        * DON'T set SHAREABLE bit for log trees.
> >        *
> > @@ -1233,26 +1240,31 @@ static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
> >
> >       leaf = btrfs_alloc_tree_block(trans, root, 0, BTRFS_TREE_LOG_OBJECTID,
> >                       NULL, 0, 0, 0, BTRFS_NESTING_NORMAL);
> > -     if (IS_ERR(leaf)) {
> > -             btrfs_put_root(root);
> > -             return ERR_CAST(leaf);
> > -     }
> > +     if (IS_ERR(leaf))
> > +             return PTR_ERR(leaf);
> >
> >       root->node = leaf;
> >
> >       btrfs_mark_buffer_dirty(root->node);
> >       btrfs_tree_unlock(root->node);
> > -     return root;
> > +
> > +     return 0;
> >   }
> >
> >   int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
> >                            struct btrfs_fs_info *fs_info)
> >   {
> >       struct btrfs_root *log_root;
> > +     int ret;
> >
> >       log_root = alloc_log_tree(trans, fs_info);
> >       if (IS_ERR(log_root))
>
> newline.
>
> >               return PTR_ERR(log_root);
> > +     ret = btrfs_alloc_log_tree_node(trans, log_root);
> > +     if (ret) {
> > +             kfree(log_root);
>
> btrfs_put_root(log_root);
>
> > +             return ret;
> > +     }
>
> newline.  Thanks,
>
> Josef

These should've shown up on the patch formatter... was it simply not run,
or did the patch formatter not catch it?

Best regards,
Amy Parker
(they/them)

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 19/41] btrfs: redirty released extent buffers in ZONED mode
  2020-11-03 14:41     ` Josef Bacik
@ 2020-11-06  9:11       ` Johannes Thumshirn
  2020-11-06 15:01         ` Josef Bacik
  0 siblings, 1 reply; 119+ messages in thread
From: Johannes Thumshirn @ 2020-11-06  9:11 UTC (permalink / raw)
  To: Josef Bacik, Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 03/11/2020 15:43, Josef Bacik wrote:
> This is a lot of work when you could just add
> 
> if (btrfs_is_zoned(fs_info))
> 	return;
> 
> to btrfs_clean_tree_block().  The dirty secret is we don't actually unset the 
> bits in the transaction io tree because it would require memory allocation 
> sometimes, so you don't even need to mess with ->dirty_pages in the first place. 
>   The only thing you need is to keep from clearing the EB dirty.  In fact you 
> could just do
> 
> if (btrfs_is_zoned(fs_info)) {
> 	memzero_extent_buffer(eb, 0, eb->len);
> 	set_bit(EXTENT_BUFFER_NO_CHECK, &eb->bflags);
> }
> 
> to btrfs_clean_tree_block() and then in btrfs_free_tree_block() make sure we 
> always pin the extent if we're zoned.  Thanks,

As much as I'd love the simple solution you described it unfortunately didn't work
in our testing [1]. So unless I did something completely stupid [2] (which always
is an option) I don't think we can go with the easy solution here, unfortunately.

[1]
btrfs/001       [   16.212869] BTRFS error (device nullb1): unable to find ref byte nr 805388288 parent 805388288 root 5  owner 0 offset 0
[   16.214314] BTRFS: error (device nullb1) in __btrfs_free_extent:3196: errno=-2 No such entry
[   16.215270] BTRFS: error (device nullb1) in btrfs_run_delayed_refs:2215: errno=-2 No such entry                                                                                    
[   16.266987] BTRFS error (device nullb1): unable to find ref byte nr 805388288 parent 805388288 root 5  owner 0 offset 0                                
[   16.268788] BTRFS: error (device nullb1) in __btrfs_free_extent:3196: errno=-2 No such entry                                           
[   16.269973] BTRFS: error (device nullb1) in btrfs_run_delayed_refs:2215: errno=-2 No such entry
[   16.271210] BTRFS: error (device nullb1) in cleanup_transaction:1904: errno=-2 No such entry                                                  
[   16.297358] BTRFS error (device nullb1): unable to find ref byte nr 805502976 parent 805502976 root 1  owner 0 offset 0                       
[   16.299128] BTRFS: error (device nullb1) in __btrfs_free_extent:3196: errno=-2 No such entry   
[   16.300324] BTRFS: error (device nullb1) in btrfs_run_delayed_refs:2215: errno=-2 No such entry
[   16.335600] BTRFS error (device nullb1): unable to find ref byte nr 805388288 parent 805388288 root 5  owner 0 offset 0
[   16.337600] BTRFS: error (device nullb1) in __btrfs_free_extent:3196: errno=-2 No such entry
[   16.338785] BTRFS: error (device nullb1) in btrfs_run_delayed_refs:2215: errno=-2 No such entry                                                                                    
[   16.340026] BTRFS: error (device nullb1) in cleanup_transaction:1904: errno=-2 No such entry            
[   16.366461] BTRFS error (device nullb0): unable to find ref byte nr 805502976 parent 805502976 root 1  owner 0 offset 0
[   16.368304] BTRFS: error (device nullb0) in __btrfs_free_extent:3196: errno=-2 No such entry
[   16.369480] BTRFS: error (device nullb0) in btrfs_run_delayed_refs:2215: errno=-2 No such entry
[   16.370689] BTRFS: error (device nullb0) in cleanup_transaction:1904: errno=-2 No such entry
[   16.392890] BTRFS error (device nullb1): unable to find ref byte nr 805388288 parent 805388288 root 5  owner 0 offset 0
[   16.394531] BTRFS: error (device nullb1) in __btrfs_free_extent:3196: errno=-2 No such entry
[   16.395612] BTRFS: error (device nullb1) in btrfs_run_delayed_refs:2215: errno=-2 No such entry                                                        
[   16.396648] BTRFS: error (device nullb1) in cleanup_transaction:1904: errno=-2 No such entry
[   16.422315] BTRFS error (device nullb1): unable to find ref byte nr 805502976 parent 805502976 root 1  owner 0 offset 0                
[   16.424147] BTRFS: error (device nullb1) in __btrfs_free_extent:3196: errno=-2 No such entry
[   16.425320] BTRFS: error (device nullb1) in btrfs_run_delayed_refs:2215: errno=-2 No such entry
[   16.426532] BTRFS: error (device nullb1) in cleanup_transaction:1904: errno=-2 No such entry
_check_dmesg: something found in dmesg (see /home/johannes/src/xfstests-dev/results//btrfs/001.dmesg)
- output mismatch (see /home/johannes/src/xfstests-dev/results//btrfs/001.out.bad)
    --- tests/btrfs/001.out     2020-01-07 15:49:53.000000000 +0000
    +++ /home/johannes/src/xfstests-dev/results//btrfs/001.out.bad      2020-11-05 16:17:37.266632915 +0000
    @@ -3,38 +3,29 @@
     List root dir
     foo
     Creating snapshot of root dir
    +ERROR: cannot snapshot '/mnt/scratch': No such file or directory
     Create a snapshot of 'SCRATCH_MNT' in 'SCRATCH_MNT/snap'
     List root dir after snapshot
    -foo
    ...
    (Run 'diff -u /home/johannes/src/xfstests-dev/tests/btrfs/001.out /home/johannes/src/xfstests-dev/results//btrfs/001.out.bad'  to see the entire diff)

[2]
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index e896dd564434..e1bf3b561b45 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1013,7 +1013,11 @@ struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
 void btrfs_clean_tree_block(struct extent_buffer *buf)
 {
        struct btrfs_fs_info *fs_info = buf->fs_info;
-       if (btrfs_header_generation(buf) ==
+
+       if (btrfs_is_zoned(fs_info)) {
+               memzero_extent_buffer(buf, 0, buf->len);
+               set_bit(EXTENT_BUFFER_NO_CHECK, &buf->bflags);
+       } else if (btrfs_header_generation(buf) ==
            fs_info->running_transaction->transid) {
                btrfs_assert_tree_locked(buf);
 
@@ -4639,8 +4643,6 @@ void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans,
                                     EXTENT_DIRTY);
        btrfs_destroy_pinned_extent(fs_info, &cur_trans->pinned_extents);
 
-       btrfs_free_redirty_list(cur_trans);
-
        cur_trans->state =TRANS_STATE_COMPLETED;
        wake_up(&cur_trans->commit_wait);
 }
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index bfd7f3082037..f9f9c329fa69 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3432,15 +3432,23 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
                pin = old_ref_mod >= 0 && new_ref_mod < 0;
        }
 
+       if (btrfs_is_zoned(fs_info)) {
+               struct btrfs_block_group *cache;
+
+               cache = btrfs_lookup_block_group(fs_info, buf->start);
+               pin_down_extent(trans, cache, buf->start, buf->len, 1);
+               btrfs_put_block_group(cache);
+               pin = 0;
+               goto out;
+       }
+
        if (last_ref && btrfs_header_generation(buf) == trans->transid) {
                struct btrfs_block_group *cache;
 
                if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
                        ret = check_ref_cleanup(trans, buf->start);
-                       if (!ret) {
-                               btrfs_redirty_list_add(trans->transaction, buf);
+                       if (!ret)
                                goto out;
-                       }
                }
 
                pin = 0;
@@ -3452,13 +3460,6 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
                        goto out;
                }
 
-               if (btrfs_is_zoned(fs_info)) {
-                       btrfs_redirty_list_add(trans->transaction, buf);
-                       pin_down_extent(trans, cache, buf->start, buf->len, 1);
-                       btrfs_put_block_group(cache);
-                       goto out;
-               }
-
                WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags));
 
                btrfs_add_free_space(cache, buf->start, buf->len);
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index a8561536cd0d..4acc96969959 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -2348,13 +2348,6 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
                goto scrub_continue;
        }
 
-       /*
-        * At this point, we should have written all the tree blocks
-        * allocated in this transaction. So it's now safe to free the
-        * redirtyied extent buffers.
-        */
-       btrfs_free_redirty_list(cur_trans);
-
        ret = write_all_supers(fs_info, 0);
        /*
         * the super is written, we can safely allow the tree-loggers
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 15f9e8a461ee..e91bdfbb03da 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -2763,8 +2763,6 @@ static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
                                                free_extent_buffer(next);
                                                return ret;
                                        }
-                                       btrfs_redirty_list_add(
-                                               trans->transaction, next);
                                } else {
                                        if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags))
                                                clear_extent_buffer_dirty(next);
@@ -3313,8 +3311,6 @@ static void free_log_tree(struct btrfs_trans_handle *trans,
                          EXTENT_DIRTY | EXTENT_NEW | EXTENT_NEED_WAIT);
        extent_io_tree_release(&log->log_csum_range);
 
-       if (trans && log->node)
-               btrfs_redirty_list_add(trans->transaction, log->node);
        btrfs_put_root(log);
 }
 
diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h
index 5b61500a0aa9..3140c39d3728 100644
--- a/fs/btrfs/zoned.h
+++ b/fs/btrfs/zoned.h
@@ -42,9 +42,6 @@ int btrfs_reset_device_zone(struct btrfs_device *device, u64 physical,
 int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size);
 int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache);
 void btrfs_calc_zone_unusable(struct btrfs_block_group *cache);
-void btrfs_redirty_list_add(struct btrfs_transaction *trans,
-                           struct extent_buffer *eb);
-void btrfs_free_redirty_list(struct btrfs_transaction *trans);
 void btrfs_record_physical_zoned(struct inode *inode, u64 file_offset,
                                 struct bio *bio);
 void btrfs_rewrite_logical_zoned(struct btrfs_ordered_extent *ordered);
@@ -137,10 +134,6 @@ static inline int btrfs_load_block_group_zone_info(
 
 static inline void btrfs_calc_zone_unusable(struct btrfs_block_group *cache) { }
 
-static inline void btrfs_redirty_list_add(struct btrfs_transaction *trans,
-                                         struct extent_buffer *eb) { }
-static inline void btrfs_free_redirty_list(struct btrfs_transaction *trans) { }
-
 static inline void btrfs_record_physical_zoned(struct inode *inode,
                                               u64 file_offset, struct bio *bio)
 {






^ permalink raw reply related	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 05/41] btrfs: Check and enable ZONED mode
  2020-11-03 12:13     ` David Sterba
@ 2020-11-06  9:36       ` Naohiro Aota
  0 siblings, 0 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-11-06  9:36 UTC (permalink / raw)
  To: dsterba, linux-btrfs, dsterba, hare, linux-fsdevel,
	Johannes Thumshirn, Damien Le Moal, Josef Bacik

On Tue, Nov 03, 2020 at 01:13:45PM +0100, David Sterba wrote:
>Below are suggested message updates, common prefix "zoned:" in case it
>happens inside the zone mode implementation. Some of them sound strange
>when repeating 'zoned', but for clarity I think it should stay, unless
>somebody has a better suggestion.
>
>On Fri, Oct 30, 2020 at 10:51:12PM +0900, Naohiro Aota wrote:
>> index aac3d6f4e35b..25fd4e97dd2a 100644
>> --- a/fs/btrfs/ctree.h
>> +++ b/fs/btrfs/ctree.h
>> @@ -3595,4 +3601,8 @@ static inline int btrfs_is_testing(struct btrfs_fs_info *fs_info)
>>  }
>>  #endif
>>
>> +static inline bool btrfs_is_zoned(struct btrfs_fs_info *fs_info)
>> +{
>> +	return fs_info->zoned != 0;
>> +}
>
>newline
>
>>  #endif
>
>> diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
>> index 6f6d77224c2b..5e3554482af1 100644
>> --- a/fs/btrfs/dev-replace.c
>> +++ b/fs/btrfs/dev-replace.c
>> @@ -238,6 +238,13 @@ static int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
>>  		return PTR_ERR(bdev);
>>  	}
>>
>> +	if (!btrfs_check_device_zone_type(fs_info, bdev)) {
>> +		btrfs_err(fs_info,
>> +			  "zone type of target device mismatch with the filesystem!");
>
>		"dev-replace: zoned type of target device mismatch with filesystem"
>
>> +		ret = -EINVAL;
>> +		goto error;
>> +	}
>> +
>>  	sync_blockdev(bdev);
>>
>>  	list_for_each_entry(device, &fs_info->fs_devices->devices, dev_list) {
>> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
>> index 764001609a15..9bc51cff48b8 100644
>> --- a/fs/btrfs/disk-io.c
>> +++ b/fs/btrfs/disk-io.c
>> @@ -3130,7 +3133,15 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
>>
>>  	btrfs_free_extra_devids(fs_devices, 1);
>>
>> +	ret = btrfs_check_zoned_mode(fs_info);
>> +	if (ret) {
>> +		btrfs_err(fs_info, "failed to init ZONED mode: %d",
>
>		"failed to inititialize zoned mode: %d"
>
>> +				ret);
>> +		goto fail_block_groups;
>> +	}
>> +
>>  	ret = btrfs_sysfs_add_fsid(fs_devices);
>> +
>>  	if (ret) {
>>  		btrfs_err(fs_info, "failed to init sysfs fsid interface: %d",
>>  				ret);
>> --- a/fs/btrfs/zoned.c
>> +++ b/fs/btrfs/zoned.c
>> +	u64 nr_devices = 0;
>> +	u64 zone_size = 0;
>> +	int incompat_zoned = btrfs_is_zoned(fs_info);
>
>	const bool
>
>> +	int ret = 0;
>> +
>> +	/* Count zoned devices */
>> +	list_for_each_entry(device, &fs_devices->devices, dev_list) {
>> +		enum blk_zoned_model model;
>> +
>> +		if (!device->bdev)
>> +			continue;
>> +
>> +		model = bdev_zoned_model(device->bdev);
>> +		if (model == BLK_ZONED_HM ||
>> +		    (model == BLK_ZONED_HA && incompat_zoned)) {
>> +			hmzoned_devices++;
>> +			if (!zone_size) {
>> +				zone_size = device->zone_info->zone_size;
>> +			} else if (device->zone_info->zone_size != zone_size) {
>> +				btrfs_err(fs_info,
>> +					  "Zoned block devices must have equal zone sizes");
>
>				"zoned: unequal block device zone sizes: have %u found %u"
>
>> +				ret = -EINVAL;
>> +				goto out;
>> +			}
>> +		}
>> +		nr_devices++;
>> +	}
>> +
>> +	if (!hmzoned_devices && !incompat_zoned)
>> +		goto out;
>> +
>> +	if (!hmzoned_devices && incompat_zoned) {
>> +		/* No zoned block device found on ZONED FS */
>> +		btrfs_err(fs_info,
>> +			  "ZONED enabled file system should have zoned devices");
>
>		"zoned: no zoned devices found on a zoned filesystem"
>
>> +		ret = -EINVAL;
>> +		goto out;
>> +	}
>> +
>> +	if (hmzoned_devices && !incompat_zoned) {
>> +		btrfs_err(fs_info,
>> +			  "Enable ZONED mode to mount HMZONED device");
>
>Is HMZONED reference leftover from previous iterations?
>
>		"zoned: mode not enabled but zoned device found"

It was intentional here to use "hmzoned", because we can technically use
Host-Aware Zoned device as regular device, so I'd like to distinguish
hmzoned vs hazoned. But, reading the code again, I changed my mind. We can
just say "a HMZONED device" or "a HAZONED device in ZONED mode" as a zoned
device. Actually, I was not counting "hazoned_devices" anyway. So, I'll
rename hmzoned_devices to zoned_devices in the next version.

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 11/41] btrfs: implement log-structured superblock for ZONED mode
  2020-11-03 14:10     ` David Sterba
@ 2020-11-06 10:37       ` Naohiro Aota
  0 siblings, 0 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-11-06 10:37 UTC (permalink / raw)
  To: dsterba, linux-btrfs, dsterba, hare, linux-fsdevel

On Tue, Nov 03, 2020 at 03:10:35PM +0100, David Sterba wrote:
>On Fri, Oct 30, 2020 at 10:51:18PM +0900, Naohiro Aota wrote:
>> Superblock (and its copies) is the only data structure in btrfs which has a
>> fixed location on a device. Since we cannot overwrite in a sequential write
>> required zone, we cannot place superblock in the zone. One easy solution is
>> limiting superblock and copies to be placed only in conventional zones.
>> However, this method has two downsides: one is reduced number of superblock
>> copies. The location of the second copy of superblock is 256GB, which is in
>> a sequential write required zone on typical devices in the market today.
>> So, the number of superblock and copies is limited to be two.  Second
>> downside is that we cannot support devices which have no conventional zones
>> at all.
>>
>> To solve these two problems, we employ superblock log writing. It uses two
>> zones as a circular buffer to write updated superblocks. Once the first
>> zone is filled up, start writing into the second buffer. Then, when the
>> both zones are filled up and before start writing to the first zone again,
>> it reset the first zone.
>>
>> We can determine the position of the latest superblock by reading write
>> pointer information from a device. One corner case is when the both zones
>> are full. For this situation, we read out the last superblock of each
>> zone, and compare them to determine which zone is older.
>>
>> The following zones are reserved as the circular buffer on ZONED btrfs.
>>
>> - The primary superblock: zones 0 and 1
>> - The first copy: zones 16 and 17
>> - The second copy: zones 1024 or zone at 256GB which is minimum, and next
>>   to it
>>
>> If these reserved zones are conventional, superblock is written fixed at
>> the start of the zone without logging.
>
>I don't have a clear picture here.
>
>In case there's a conventional zone covering 0 and 1st copy (64K and
>64M) it'll be overwritten. What happens for 2nd copy that's at 256G?
>sb-log?
>
>For all-sequential drive, the 0 and 1st copy are in the first zone.
>You say 0 and 1, but how come if the minimum zone size we ever expect is
>256M?

On zoned device, we always reserve the above zones (0, 1, 16, 17, 1024,
1025 (or zones at 256G)) regardless of it is sequential or conventional.
And, if the reserved zones is conventional, we write a superblock always at
the beginning of the reserved zone. So, if a drive have 32
conventional zones, superblocks are placed at the beginning of zone 0 and
zone 16. And, zone 1024 and 1025 are written with sb-log.

>
>The circular buffer comprises zones covering all superblock copies? I
>mean one buffer for 2 or more sb copies? The problem is that we'll have
>just one copy of the current superblock. Or I misunderstood.

A circular buffer consists with a pair of the zones, so we'll have three
sb-logs for each on zone pairs 0 & 1, zones 16 & 17, and 1024 & 1025.

>
>My idea is that we have primary zone, unfortunatelly covering 2
>superblocks but let it be. Second zone contains 2nd superblock copy
>(256G), we can assume that devices will be bigger than that.
>
>Then the circular buffers happen in each zone, so first one will go from
>offset 64K up to the zone size (256M or 1G).  Second zone rotates from
>offset 0 to end of the zone.
>
>The positive outcome of that is that both zones contain the latest
>superblock after succesful write and their write pointer is slightly out
>of sync, so they never have to be reset at the same time.
>
>In numbers:
>- first zone 64K .. 256M, 65520 superblocks
>- second zone 256G .. 245G+256M, 65536 superblocks
>
>The difference is 16 superblock updates, which should be enough to let
>the zone resets happen far apart.

Hmm, this makes the minimal FS size requirement to 256 GB to survive a
crash after resetting the first zone... So, that's why we have two zones as
a circular buffer.

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 24/41] btrfs: extend btrfs_rmap_block for specifying a device
  2020-11-03 15:32     ` Josef Bacik
@ 2020-11-06 10:52       ` Johannes Thumshirn
  0 siblings, 0 replies; 119+ messages in thread
From: Johannes Thumshirn @ 2020-11-06 10:52 UTC (permalink / raw)
  To: Josef Bacik, Naohiro Aota, linux-btrfs, dsterba; +Cc: hare, linux-fsdevel

On 03/11/2020 16:32, Josef Bacik wrote:
[...]
> Since there's only one caller of btrfs_rmap_block() in this file, and the rest 
> are for tests, you might as well just make btrfs_rmap_block() exported with the 
> device, and switch the existing callers to use NULL for the device.  Thanks,

Fixed

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 19/41] btrfs: redirty released extent buffers in ZONED mode
  2020-11-06  9:11       ` Johannes Thumshirn
@ 2020-11-06 15:01         ` Josef Bacik
  0 siblings, 0 replies; 119+ messages in thread
From: Josef Bacik @ 2020-11-06 15:01 UTC (permalink / raw)
  To: Johannes Thumshirn, Naohiro Aota, linux-btrfs, dsterba
  Cc: hare, linux-fsdevel

On 11/6/20 4:11 AM, Johannes Thumshirn wrote:
> On 03/11/2020 15:43, Josef Bacik wrote:
>> This is a lot of work when you could just add
>>
>> if (btrfs_is_zoned(fs_info))
>> 	return;
>>
>> to btrfs_clean_tree_block().  The dirty secret is we don't actually unset the
>> bits in the transaction io tree because it would require memory allocation
>> sometimes, so you don't even need to mess with ->dirty_pages in the first place.
>>    The only thing you need is to keep from clearing the EB dirty.  In fact you
>> could just do
>>
>> if (btrfs_is_zoned(fs_info)) {
>> 	memzero_extent_buffer(eb, 0, eb->len);
>> 	set_bit(EXTENT_BUFFER_NO_CHECK, &eb->bflags);
>> }
>>
>> to btrfs_clean_tree_block() and then in btrfs_free_tree_block() make sure we
>> always pin the extent if we're zoned.  Thanks,
> 
> As much as I'd love the simple solution you described it unfortunately didn't work
> in our testing [1]. So unless I did something completely stupid [2] (which always
> is an option) I don't think we can go with the easy solution here, unfortunately.
> 

Actually it's because we're calling btrfs_clean_tree_block() in 
btrfs_init_new_buffer(), so any new block is now getting marked as 
BUFFER_NO_CHECk, hence everything blowing up.

I think first you push btrfs_clean_tree_block() into btrfs_free_tree_block() and 
kill all other callers, because we're just marking it no longer dirty.  In fact 
I'd rename it as btrfs_mark_extent_buffer_clean() or something like that.  Then 
your patch should work just fine.  Thanks,

Josef


^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 38/41] btrfs: extend zoned allocator to use dedicated tree-log block group
  2020-11-03 20:47     ` Josef Bacik
@ 2020-11-10  6:37       ` Naohiro Aota
  0 siblings, 0 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-11-10  6:37 UTC (permalink / raw)
  To: Josef Bacik; +Cc: linux-btrfs, dsterba, hare, linux-fsdevel, Johannes Thumshirn

On Tue, Nov 03, 2020 at 03:47:33PM -0500, Josef Bacik wrote:
>On 10/30/20 9:51 AM, Naohiro Aota wrote:
>>This is the 1/3 patch to enable tree log on ZONED mode.
>>
>>The tree-log feature does not work on ZONED mode as is. Blocks for a
>>tree-log tree are allocated mixed with other metadata blocks, and btrfs
>>writes and syncs the tree-log blocks to devices at the time of fsync(),
>>which is different timing from a global transaction commit. As a result,
>>both writing tree-log blocks and writing other metadata blocks become
>>non-sequential writes that ZONED mode must avoid.
>>
>>We can introduce a dedicated block group for tree-log blocks so that
>>tree-log blocks and other metadata blocks can be separated write streams.
>>As a result, each write stream can now be written to devices separately.
>>"fs_info->treelog_bg" tracks the dedicated block group and btrfs assign
>>"treelog_bg" on-demand on tree-log block allocation time.
>>
>>This commit extends the zoned block allocator to use the block group.
>>
>>Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
>>Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
>
>If you're going to remove an entire block group from being allowed to 
>be used for metadata you are going to need to account for it in the 
>space_info, otherwise we're going to end up with nasty ENOSPC corners 
>here.

Indeed. I'll add a dedicated space_info for treelog or, at least, separate
the block group from other metadata space_info. But, I'll address this
later in v11.

>
>But this begs the question, do we want the tree log for zoned?  We 
>could just commit the transaction and call it good enough.  We lose 
>performance, but zoned isn't necessarily about performance.

We have a large performance drop without tree-log (-o notreelog). Here is a
dbench (32 clients) result on SMR HDD.

With treelog:    153.509  MB/s	
Without treelog:  21.9651 MB/s

So, there is 85% drop of the throughput. I think this degradation is too large.

>
>If we do then at a minimum we're going to need to remove this block 
>group from the space info counters for metadata.  Thanks,
>
>Josef

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 07/41] btrfs: disallow space_cache in ZONED mode
  2020-11-03 12:48     ` David Sterba
@ 2020-11-10 10:14       ` Naohiro Aota
  0 siblings, 0 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-11-10 10:14 UTC (permalink / raw)
  To: dsterba, linux-btrfs, dsterba, hare, linux-fsdevel

On Tue, Nov 03, 2020 at 01:48:34PM +0100, David Sterba wrote:
>On Fri, Oct 30, 2020 at 10:51:14PM +0900, Naohiro Aota wrote:
>> INODE_MAP_CACHE inode.
>>
>> In summary, ZONED will disable:
>>
>> | Disabled features | Reason                                              |
>> |-------------------+-----------------------------------------------------|
>> | RAID/Dup          | Cannot handle two zone append writes to different   |
>> |                   | zones                                               |
>> |-------------------+-----------------------------------------------------|
>> | space_cache (v1)  | In-place updating                                   |
>> | NODATACOW         | In-place updating                                   |
>> |-------------------+-----------------------------------------------------|
>> | fallocate         | Reserved extent will be a write hole                |
>> | INODE_MAP_CACHE   | Need pre-allocation. (and will be deprecated?)      |
>
>space_cache is deprecated and actually in current dev cycle (5.11)
>
>> |-------------------+-----------------------------------------------------|
>> | MIXED_BG          | Allocated metadata region will be write holes for   |
>> |                   | data writes                                         |
>>
>> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
>> ---
>>  fs/btrfs/super.c | 12 ++++++++++--
>>  fs/btrfs/zoned.c | 18 ++++++++++++++++++
>>  fs/btrfs/zoned.h |  5 +++++
>>  3 files changed, 33 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
>> index 3312fe08168f..9064ca62b0a0 100644
>> --- a/fs/btrfs/super.c
>> +++ b/fs/btrfs/super.c
>> @@ -525,8 +525,14 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
>>  	cache_gen = btrfs_super_cache_generation(info->super_copy);
>>  	if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE))
>>  		btrfs_set_opt(info->mount_opt, FREE_SPACE_TREE);
>> -	else if (cache_gen)
>> -		btrfs_set_opt(info->mount_opt, SPACE_CACHE);
>> +	else if (cache_gen) {
>> +		if (btrfs_is_zoned(info)) {
>> +			btrfs_info(info,
>> +			"clearring existing space cache in ZONED mode");
>
>			"zoned: clearing existing space cache"
>
>Is it clearing or just invalidating it? We have the same problem with
>enabling v2 so this could share some code once Boris' patches are
>merged.


Yep, this is just invalidating it. I'll use
btrfs_set_free_space_cache_v1_active here once the patches are merged.

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 18/41] btrfs: reset zones of unused block groups
  2020-11-03 14:34     ` Josef Bacik
@ 2020-11-10 10:40       ` Naohiro Aota
  0 siblings, 0 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-11-10 10:40 UTC (permalink / raw)
  To: Josef Bacik; +Cc: linux-btrfs, dsterba, hare, linux-fsdevel

On Tue, Nov 03, 2020 at 09:34:19AM -0500, Josef Bacik wrote:
>On 10/30/20 9:51 AM, Naohiro Aota wrote:
>>For an ZONED volume, a block group maps to a zone of the device. For
>>deleted unused block groups, the zone of the block group can be reset to
>>rewind the zone write pointer at the start of the zone.
>>
>>Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
>>---
>>  fs/btrfs/block-group.c |  8 ++++++--
>>  fs/btrfs/extent-tree.c | 17 ++++++++++++-----
>>  fs/btrfs/zoned.h       | 16 ++++++++++++++++
>>  3 files changed, 34 insertions(+), 7 deletions(-)
>>
>>diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
>>index d67f9cabe5c1..82d556368c85 100644
>>--- a/fs/btrfs/block-group.c
>>+++ b/fs/btrfs/block-group.c
>>@@ -1468,8 +1468,12 @@ void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
>>  		if (!async_trim_enabled && btrfs_test_opt(fs_info, DISCARD_ASYNC))
>>  			goto flip_async;
>>-		/* DISCARD can flip during remount */
>>-		trimming = btrfs_test_opt(fs_info, DISCARD_SYNC);
>>+		/*
>>+		 * DISCARD can flip during remount. In ZONED mode, we need
>>+		 * to reset sequential required zones.
>>+		 */
>>+		trimming = btrfs_test_opt(fs_info, DISCARD_SYNC) ||
>>+				btrfs_is_zoned(fs_info);
>>  		/* Implicit trim during transaction commit. */
>>  		if (trimming)
>>diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
>>index 5e6b4d1712f2..c134746d7417 100644
>>--- a/fs/btrfs/extent-tree.c
>>+++ b/fs/btrfs/extent-tree.c
>>@@ -1331,6 +1331,9 @@ int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
>>  		stripe = bbio->stripes;
>>  		for (i = 0; i < bbio->num_stripes; i++, stripe++) {
>>+			struct btrfs_device *dev = stripe->dev;
>>+			u64 physical = stripe->physical;
>>+			u64 length = stripe->length;
>>  			u64 bytes;
>>  			struct request_queue *req_q;
>>@@ -1338,14 +1341,18 @@ int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
>>  				ASSERT(btrfs_test_opt(fs_info, DEGRADED));
>>  				continue;
>>  			}
>>+
>>  			req_q = bdev_get_queue(stripe->dev->bdev);
>>-			if (!blk_queue_discard(req_q))
>>+			/* zone reset in ZONED mode */
>>+			if (btrfs_can_zone_reset(dev, physical, length))
>>+				ret = btrfs_reset_device_zone(dev, physical,
>>+							      length, &bytes);
>>+			else if (blk_queue_discard(req_q))
>>+				ret = btrfs_issue_discard(dev->bdev, physical,
>>+							  length, &bytes);
>>+			else
>>  				continue;
>>-			ret = btrfs_issue_discard(stripe->dev->bdev,
>>-						  stripe->physical,
>>-						  stripe->length,
>>-						  &bytes);
>
>The problem is you have
>
>if (btrfs_test_opt(fs_info, DISCARD_SYNC))
>	ret = btrfs_discard_extent(fs_info, start,
>				   end + 1 - start, NULL);
>
>in btrfs_finish_extent_commit, so even if you add support here, you 
>aren't actually discarding anything because the transaction commit 
>won't call discard for this range.

btrfs_discard_extent() is called for each deleted_bg on the BG area,
regardless of the above pinned_extent's range.

>
>You're going to have to rework this logic to allow for discard to be 
>called everywhere it checks DISCARD_SYNC, but then you also need to go 
>and make sure you don't actually allow discards to happen at non-bg 
>aligned ranges.  Thanks,
>
>Josef

We already ignore btrfs_discard_extent() which is not aligned to zone. So,
I confirmed it worked fine with DISCARD_SYNC.


^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 21/41] btrfs: use bio_add_zone_append_page for zoned btrfs
  2020-11-03 14:55     ` Josef Bacik
@ 2020-11-10 10:42       ` Naohiro Aota
  0 siblings, 0 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-11-10 10:42 UTC (permalink / raw)
  To: Josef Bacik; +Cc: linux-btrfs, dsterba, hare, linux-fsdevel

On Tue, Nov 03, 2020 at 09:55:49AM -0500, Josef Bacik wrote:
>On 10/30/20 9:51 AM, Naohiro Aota wrote:
>>Zoned device has its own hardware restrictions e.g. max_zone_append_size
>>when using REQ_OP_ZONE_APPEND. To follow the restrictions, use
>>bio_add_zone_append_page() instead of bio_add_page(). We need target device
>>to use bio_add_zone_append_page(), so this commit reads the chunk
>>information to memoize the target device to btrfs_io_bio(bio)->device.
>>
>>Currently, zoned btrfs only supports SINGLE profile. In the feature,
>>btrfs_io_bio can hold extent_map and check the restrictions for all the
>>devices the bio will be mapped.
>>
>>Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
>>---
>>  fs/btrfs/extent_io.c | 37 ++++++++++++++++++++++++++++++++++---
>>  1 file changed, 34 insertions(+), 3 deletions(-)
>>
>>diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
>>index 17285048fb5a..764257eb658f 100644
>>--- a/fs/btrfs/extent_io.c
>>+++ b/fs/btrfs/extent_io.c
>>@@ -3032,6 +3032,7 @@ bool btrfs_bio_add_page(struct bio *bio, struct page *page, u64 logical,
>>  {
>>  	sector_t sector = logical >> SECTOR_SHIFT;
>>  	bool contig;
>>+	int ret;
>>  	if (prev_bio_flags != bio_flags)
>>  		return false;
>>@@ -3046,7 +3047,19 @@ bool btrfs_bio_add_page(struct bio *bio, struct page *page, u64 logical,
>>  	if (btrfs_bio_fits_in_stripe(page, size, bio, bio_flags))
>>  		return false;
>>-	return bio_add_page(bio, page, size, pg_offset) == size;
>>+	if (bio_op(bio) == REQ_OP_ZONE_APPEND) {
>>+		struct bio orig_bio;
>>+
>>+		memset(&orig_bio, 0, sizeof(orig_bio));
>>+		bio_copy_dev(&orig_bio, bio);
>>+		bio_set_dev(bio, btrfs_io_bio(bio)->device->bdev);
>>+		ret = bio_add_zone_append_page(bio, page, size, pg_offset);
>>+		bio_copy_dev(bio, &orig_bio);
>
>Why do we need this in the first place, since we're only supporting 
>single right now?  latest_bdev should be the same, so this serves no 
>purpose, right?
>
>And if it does, we need to figure out another solution, because right 
>now this leaks references to the bio->bi_blkg, each copy inc's the 
>refcount on the blkg for that bio so we're going to leak blkg's like 
>crazy here.  Thanks,
>
>Josef

True. I just tried to make it multipe device ready as much as possible.

I'll drop this part for now, and will fix this when we add multipe device
support.

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 33/41] btrfs: implement copying for ZONED device-replace
  2020-11-03 17:19     ` Josef Bacik
@ 2020-11-10 11:09       ` Naohiro Aota
  0 siblings, 0 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-11-10 11:09 UTC (permalink / raw)
  To: Josef Bacik; +Cc: linux-btrfs, dsterba, hare, linux-fsdevel

On Tue, Nov 03, 2020 at 12:19:41PM -0500, Josef Bacik wrote:
>On 10/30/20 9:51 AM, Naohiro Aota wrote:
>>This is 3/4 patch to implement device-replace on ZONED mode.
>>
>>This commit implement copying. So, it track the write pointer during device
>>replace process. Device-replace's copying is smart to copy only used
>>extents on source device, we have to fill the gap to honor the sequential
>>write rule in the target device.
>>
>>Device-replace process in ZONED mode must copy or clone all the extents in
>>the source device exactly once.  So, we need to use to ensure allocations
>>started just before the dev-replace process to have their corresponding
>>extent information in the B-trees. finish_extent_writes_for_zoned()
>>implements that functionality, which basically is the removed code in the
>>commit 042528f8d840 ("Btrfs: fix block group remaining RO forever after
>>error during device replace").
>>
>>Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
>>---
>>  fs/btrfs/scrub.c | 86 ++++++++++++++++++++++++++++++++++++++++++++++++
>>  fs/btrfs/zoned.c | 12 +++++++
>>  fs/btrfs/zoned.h |  7 ++++
>>  3 files changed, 105 insertions(+)
>>
>>diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
>>index 371bb6437cab..aaf7882dee06 100644
>>--- a/fs/btrfs/scrub.c
>>+++ b/fs/btrfs/scrub.c
>>@@ -169,6 +169,7 @@ struct scrub_ctx {
>>  	int			pages_per_rd_bio;
>>  	int			is_dev_replace;
>>+	u64			write_pointer;
>>  	struct scrub_bio        *wr_curr_bio;
>>  	struct mutex            wr_lock;
>>@@ -1623,6 +1624,25 @@ static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
>>  	return scrub_add_page_to_wr_bio(sblock->sctx, spage);
>>  }
>>+static int fill_writer_pointer_gap(struct scrub_ctx *sctx, u64 physical)
>>+{
>>+	int ret = 0;
>>+	u64 length;
>>+
>>+	if (!btrfs_is_zoned(sctx->fs_info))
>>+		return 0;
>>+
>>+	if (sctx->write_pointer < physical) {
>>+		length = physical - sctx->write_pointer;
>>+
>>+		ret = btrfs_zoned_issue_zeroout(sctx->wr_tgtdev,
>>+						sctx->write_pointer, length);
>>+		if (!ret)
>>+			sctx->write_pointer = physical;
>>+	}
>>+	return ret;
>>+}
>>+
>>  static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
>>  				    struct scrub_page *spage)
>>  {
>>@@ -1645,6 +1665,13 @@ static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
>>  	if (sbio->page_count == 0) {
>>  		struct bio *bio;
>>+		ret = fill_writer_pointer_gap(sctx,
>>+					      spage->physical_for_dev_replace);
>>+		if (ret) {
>>+			mutex_unlock(&sctx->wr_lock);
>>+			return ret;
>>+		}
>>+
>>  		sbio->physical = spage->physical_for_dev_replace;
>>  		sbio->logical = spage->logical;
>>  		sbio->dev = sctx->wr_tgtdev;
>>@@ -1706,6 +1733,10 @@ static void scrub_wr_submit(struct scrub_ctx *sctx)
>>  	 * doubled the write performance on spinning disks when measured
>>  	 * with Linux 3.5 */
>>  	btrfsic_submit_bio(sbio->bio);
>>+
>>+	if (btrfs_is_zoned(sctx->fs_info))
>>+		sctx->write_pointer = sbio->physical +
>>+			sbio->page_count * PAGE_SIZE;
>>  }
>>  static void scrub_wr_bio_end_io(struct bio *bio)
>>@@ -2973,6 +3004,21 @@ static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
>>  	return ret < 0 ? ret : 0;
>>  }
>>+static void sync_replace_for_zoned(struct scrub_ctx *sctx)
>>+{
>>+	if (!btrfs_is_zoned(sctx->fs_info))
>>+		return;
>>+
>>+	sctx->flush_all_writes = true;
>>+	scrub_submit(sctx);
>>+	mutex_lock(&sctx->wr_lock);
>>+	scrub_wr_submit(sctx);
>>+	mutex_unlock(&sctx->wr_lock);
>>+
>>+	wait_event(sctx->list_wait,
>>+		   atomic_read(&sctx->bios_in_flight) == 0);
>>+}
>>+
>>  static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
>>  					   struct map_lookup *map,
>>  					   struct btrfs_device *scrub_dev,
>>@@ -3105,6 +3151,14 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
>>  	 */
>>  	blk_start_plug(&plug);
>>+	if (sctx->is_dev_replace &&
>>+	    btrfs_dev_is_sequential(sctx->wr_tgtdev, physical)) {
>>+		mutex_lock(&sctx->wr_lock);
>>+		sctx->write_pointer = physical;
>>+		mutex_unlock(&sctx->wr_lock);
>>+		sctx->flush_all_writes = true;
>>+	}
>>+
>>  	/*
>>  	 * now find all extents for each stripe and scrub them
>>  	 */
>>@@ -3292,6 +3346,9 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
>>  			if (ret)
>>  				goto out;
>>+			if (sctx->is_dev_replace)
>>+				sync_replace_for_zoned(sctx);
>>+
>>  			if (extent_logical + extent_len <
>>  			    key.objectid + bytes) {
>>  				if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
>>@@ -3414,6 +3471,25 @@ static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
>>  	return ret;
>>  }
>>+static int finish_extent_writes_for_zoned(struct btrfs_root *root,
>>+					  struct btrfs_block_group *cache)
>>+{
>>+	struct btrfs_fs_info *fs_info = cache->fs_info;
>>+	struct btrfs_trans_handle *trans;
>>+
>>+	if (!btrfs_is_zoned(fs_info))
>>+		return 0;
>>+
>>+	btrfs_wait_block_group_reservations(cache);
>>+	btrfs_wait_nocow_writers(cache);
>>+	btrfs_wait_ordered_roots(fs_info, U64_MAX, cache->start, cache->length);
>>+
>>+	trans = btrfs_join_transaction(root);
>>+	if (IS_ERR(trans))
>>+		return PTR_ERR(trans);
>>+	return btrfs_commit_transaction(trans);
>>+}
>>+
>>  static noinline_for_stack
>>  int scrub_enumerate_chunks(struct scrub_ctx *sctx,
>>  			   struct btrfs_device *scrub_dev, u64 start, u64 end)
>>@@ -3569,6 +3645,16 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx,
>>  		 * group is not RO.
>>  		 */
>>  		ret = btrfs_inc_block_group_ro(cache, sctx->is_dev_replace);
>>+		if (!ret && sctx->is_dev_replace) {
>>+			ret = finish_extent_writes_for_zoned(root, cache);
>>+			if (ret) {
>>+				btrfs_dec_block_group_ro(cache);
>>+				scrub_pause_off(fs_info);
>>+				btrfs_put_block_group(cache);
>>+				break;
>>+			}
>>+		}
>>+
>>  		if (ret == 0) {
>>  			ro_set = 1;
>>  		} else if (ret == -ENOSPC && !sctx->is_dev_replace) {
>>diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
>>index f672465d1bb1..1b080184440d 100644
>>--- a/fs/btrfs/zoned.c
>>+++ b/fs/btrfs/zoned.c
>>@@ -1181,3 +1181,15 @@ void btrfs_revert_meta_write_pointer(struct btrfs_block_group *cache,
>>  	ASSERT(cache->meta_write_pointer == eb->start + eb->len);
>>  	cache->meta_write_pointer = eb->start;
>>  }
>>+
>>+int btrfs_zoned_issue_zeroout(struct btrfs_device *device, u64 physical,
>>+			      u64 length)
>>+{
>>+	if (!btrfs_dev_is_sequential(device, physical))
>>+		return -EOPNOTSUPP;
>>+
>
>This is going to result in a bunch of scrub errors.  Is this unlikely 
>to happen?  And if it isn't, should we do something different?  If 
>it's not sequential then we can probably just write to whatever offset 
>we want right?  So do we need an error here at all?  Thanks,
>
>Josef

I'm intended to use this to synchronize the write pointer.  For
conventional zones, we don't need to synchronize it anyway. We can just
skip the unwritten area in the source device and continue the writing at
the different location.

^ permalink raw reply	[flat|nested] 119+ messages in thread

* Re: [PATCH v9 37/41] btrfs: split alloc_log_tree()
  2020-11-03 22:10       ` Amy Parker
@ 2020-11-10 11:12         ` Naohiro Aota
  0 siblings, 0 replies; 119+ messages in thread
From: Naohiro Aota @ 2020-11-10 11:12 UTC (permalink / raw)
  To: Amy Parker
  Cc: Josef Bacik, linux-btrfs, David Sterba, hare, linux-fsdevel,
	Johannes Thumshirn

On Tue, Nov 03, 2020 at 02:10:47PM -0800, Amy Parker wrote:
>On Tue, Nov 3, 2020 at 2:06 PM Josef Bacik <josef@toxicpanda.com> wrote:
>>
>> On 10/30/20 9:51 AM, Naohiro Aota wrote:
>> > This is a preparation for the next patch. This commit split
>> > alloc_log_tree() to allocating tree structure part (remains in
>> > alloc_log_tree()) and allocating tree node part (moved in
>> > btrfs_alloc_log_tree_node()). The latter part is also exported to be used
>> > in the next patch.
>> >
>> > Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
>> > Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
>> > ---
>> >   fs/btrfs/disk-io.c | 31 +++++++++++++++++++++++++------
>> >   fs/btrfs/disk-io.h |  2 ++
>> >   2 files changed, 27 insertions(+), 6 deletions(-)
>> >
>> > diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
>> > index 2b30ef8a7034..70885f3d3321 100644
>> > --- a/fs/btrfs/disk-io.c
>> > +++ b/fs/btrfs/disk-io.c
>> > @@ -1211,7 +1211,6 @@ static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
>> >                                        struct btrfs_fs_info *fs_info)
>> >   {
>> >       struct btrfs_root *root;
>> > -     struct extent_buffer *leaf;
>> >
>> >       root = btrfs_alloc_root(fs_info, BTRFS_TREE_LOG_OBJECTID, GFP_NOFS);
>> >       if (!root)
>> > @@ -1221,6 +1220,14 @@ static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
>> >       root->root_key.type = BTRFS_ROOT_ITEM_KEY;
>> >       root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
>> >
>> > +     return root;
>> > +}
>> > +
>> > +int btrfs_alloc_log_tree_node(struct btrfs_trans_handle *trans,
>> > +                           struct btrfs_root *root)
>> > +{
>> > +     struct extent_buffer *leaf;
>> > +
>> >       /*
>> >        * DON'T set SHAREABLE bit for log trees.
>> >        *
>> > @@ -1233,26 +1240,31 @@ static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
>> >
>> >       leaf = btrfs_alloc_tree_block(trans, root, 0, BTRFS_TREE_LOG_OBJECTID,
>> >                       NULL, 0, 0, 0, BTRFS_NESTING_NORMAL);
>> > -     if (IS_ERR(leaf)) {
>> > -             btrfs_put_root(root);
>> > -             return ERR_CAST(leaf);
>> > -     }
>> > +     if (IS_ERR(leaf))
>> > +             return PTR_ERR(leaf);
>> >
>> >       root->node = leaf;
>> >
>> >       btrfs_mark_buffer_dirty(root->node);
>> >       btrfs_tree_unlock(root->node);
>> > -     return root;
>> > +
>> > +     return 0;
>> >   }
>> >
>> >   int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
>> >                            struct btrfs_fs_info *fs_info)
>> >   {
>> >       struct btrfs_root *log_root;
>> > +     int ret;
>> >
>> >       log_root = alloc_log_tree(trans, fs_info);
>> >       if (IS_ERR(log_root))
>>
>> newline.
>>
>> >               return PTR_ERR(log_root);
>> > +     ret = btrfs_alloc_log_tree_node(trans, log_root);
>> > +     if (ret) {
>> > +             kfree(log_root);
>>
>> btrfs_put_root(log_root);
>>
>> > +             return ret;
>> > +     }
>>
>> newline.  Thanks,
>>
>> Josef
>
>These should've shown up on the patch formatter... was it simply not run,
>or did the patch formatter not catch it?

Unfotunately, it was not caught by checkpatch.pl...
>
>Best regards,
>Amy Parker
>(they/them)

^ permalink raw reply	[flat|nested] 119+ messages in thread

end of thread, other threads:[~2020-11-10 11:12 UTC | newest]

Thread overview: 119+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-10-30 13:51 [PATCH v9 00/41] btrfs: zoned block device support Naohiro Aota
2020-10-30 13:51 ` [PATCH v9 01/41] block: add bio_add_zone_append_page Naohiro Aota
2020-10-30 13:51   ` [PATCH v9 02/41] iomap: support REQ_OP_ZONE_APPEND Naohiro Aota
2020-11-02  5:34     ` Naohiro Aota
2020-11-02 16:55     ` Darrick J. Wong
2020-11-02 17:39       ` Johannes Thumshirn
2020-10-30 13:51   ` [PATCH v9 03/41] btrfs: introduce ZONED feature flag Naohiro Aota
2020-10-30 13:51   ` [PATCH v9 04/41] btrfs: Get zone information of zoned block devices Naohiro Aota
2020-11-02 16:53     ` Josef Bacik
2020-11-02 16:58       ` Johannes Thumshirn
2020-11-02 21:07       ` Naohiro Aota
2020-11-03 12:02     ` David Sterba
2020-10-30 13:51   ` [PATCH v9 05/41] btrfs: Check and enable ZONED mode Naohiro Aota
2020-11-03 12:13     ` David Sterba
2020-11-06  9:36       ` Naohiro Aota
2020-10-30 13:51   ` [PATCH v9 06/41] btrfs: introduce max_zone_append_size Naohiro Aota
2020-11-02 16:57     ` Josef Bacik
2020-11-03 12:16     ` David Sterba
2020-10-30 13:51   ` [PATCH v9 07/41] btrfs: disallow space_cache in ZONED mode Naohiro Aota
2020-11-02 17:02     ` Josef Bacik
2020-11-02 17:37       ` Johannes Thumshirn
2020-11-03 12:48     ` David Sterba
2020-11-10 10:14       ` Naohiro Aota
2020-10-30 13:51   ` [PATCH v9 08/41] btrfs: disallow NODATACOW " Naohiro Aota
2020-11-02 17:05     ` Josef Bacik
2020-11-03 12:57     ` David Sterba
2020-10-30 13:51   ` [PATCH v9 09/41] btrfs: disable fallocate " Naohiro Aota
2020-11-03 13:00     ` David Sterba
2020-10-30 13:51   ` [PATCH v9 10/41] btrfs: disallow mixed-bg " Naohiro Aota
2020-11-03 13:01     ` David Sterba
2020-10-30 13:51   ` [PATCH v9 11/41] btrfs: implement log-structured superblock for " Naohiro Aota
2020-11-02 18:22     ` Josef Bacik
2020-11-02 18:53       ` Johannes Thumshirn
2020-11-02 19:01         ` Josef Bacik
2020-11-02 19:31           ` Johannes Thumshirn
2020-11-03  8:21       ` Naohiro Aota
2020-11-02 18:54     ` Josef Bacik
2020-11-03  3:31       ` Naohiro Aota
2020-11-03 13:15     ` David Sterba
2020-11-03 14:10     ` David Sterba
2020-11-06 10:37       ` Naohiro Aota
2020-10-30 13:51   ` [PATCH v9 12/41] btrfs: implement zoned chunk allocator Naohiro Aota
2020-11-02 20:09     ` Josef Bacik
2020-11-02 22:21       ` Naohiro Aota
2020-11-03 13:23     ` David Sterba
2020-10-30 13:51   ` [PATCH v9 13/41] btrfs: verify device extent is aligned to zone Naohiro Aota
2020-11-02 20:14     ` Josef Bacik
2020-10-30 13:51   ` [PATCH v9 14/41] btrfs: load zone's alloction offset Naohiro Aota
2020-11-02 20:25     ` Josef Bacik
2020-11-02 20:29       ` Josef Bacik
2020-11-02 22:43         ` Naohiro Aota
2020-11-02 22:40       ` Naohiro Aota
2020-11-03 13:28     ` David Sterba
2020-10-30 13:51   ` [PATCH v9 15/41] btrfs: emulate write pointer for conventional zones Naohiro Aota
2020-11-02 20:37     ` Josef Bacik
2020-11-03  1:25       ` Naohiro Aota
2020-11-03 13:32     ` David Sterba
2020-10-30 13:51   ` [PATCH v9 16/41] btrfs: track unusable bytes for zones Naohiro Aota
2020-11-03 14:25     ` Josef Bacik
2020-10-30 13:51   ` [PATCH v9 17/41] btrfs: do sequential extent allocation in ZONED mode Naohiro Aota
2020-11-03 14:28     ` Josef Bacik
2020-10-30 13:51   ` [PATCH v9 18/41] btrfs: reset zones of unused block groups Naohiro Aota
2020-11-03 14:34     ` Josef Bacik
2020-11-10 10:40       ` Naohiro Aota
2020-10-30 13:51   ` [PATCH v9 19/41] btrfs: redirty released extent buffers in ZONED mode Naohiro Aota
2020-11-03 14:41     ` Josef Bacik
2020-11-06  9:11       ` Johannes Thumshirn
2020-11-06 15:01         ` Josef Bacik
2020-10-30 13:51   ` [PATCH v9 20/41] btrfs: extract page adding function Naohiro Aota
2020-11-03 14:45     ` Josef Bacik
2020-10-30 13:51   ` [PATCH v9 21/41] btrfs: use bio_add_zone_append_page for zoned btrfs Naohiro Aota
2020-11-03 14:55     ` Josef Bacik
2020-11-10 10:42       ` Naohiro Aota
2020-10-30 13:51   ` [PATCH v9 22/41] btrfs: handle REQ_OP_ZONE_APPEND as writing Naohiro Aota
2020-11-03 14:57     ` Josef Bacik
2020-10-30 13:51   ` [PATCH v9 23/41] btrfs: split ordered extent when bio is sent Naohiro Aota
2020-11-03 15:29     ` Josef Bacik
2020-10-30 13:51   ` [PATCH v9 24/41] btrfs: extend btrfs_rmap_block for specifying a device Naohiro Aota
2020-11-03 15:32     ` Josef Bacik
2020-11-06 10:52       ` Johannes Thumshirn
2020-10-30 13:51   ` [PATCH v9 25/41] btrfs: use ZONE_APPEND write for ZONED btrfs Naohiro Aota
2020-11-03 15:55     ` Josef Bacik
2020-10-30 13:51   ` [PATCH v9 26/41] btrfs: enable zone append writing for direct IO Naohiro Aota
2020-11-03 15:56     ` Josef Bacik
2020-10-30 13:51   ` [PATCH v9 27/41] btrfs: introduce dedicated data write path for ZONED mode Naohiro Aota
2020-11-03 15:57     ` Josef Bacik
2020-10-30 13:51   ` [PATCH v9 28/41] btrfs: serialize meta IOs on " Naohiro Aota
2020-11-03 16:04     ` Josef Bacik
2020-10-30 13:51   ` [PATCH v9 29/41] btrfs: wait existing extents before truncating Naohiro Aota
2020-10-30 13:51   ` [PATCH v9 30/41] btrfs: avoid async metadata checksum on ZONED mode Naohiro Aota
2020-11-03 16:05     ` Josef Bacik
2020-10-30 13:51   ` [PATCH v9 31/41] btrfs: mark block groups to copy for device-replace Naohiro Aota
2020-11-03 17:09     ` Josef Bacik
2020-10-30 13:51   ` [PATCH v9 32/41] btrfs: implement cloning for ZONED device-replace Naohiro Aota
2020-11-03 17:15     ` Josef Bacik
2020-10-30 13:51   ` [PATCH v9 33/41] btrfs: implement copying " Naohiro Aota
2020-11-03 17:19     ` Josef Bacik
2020-11-10 11:09       ` Naohiro Aota
2020-10-30 13:51   ` [PATCH v9 34/41] btrfs: support dev-replace in ZONED mode Naohiro Aota
2020-11-03 20:34     ` Josef Bacik
2020-10-30 13:51   ` [PATCH v9 35/41] btrfs: enable relocation " Naohiro Aota
2020-11-03 20:39     ` Josef Bacik
2020-10-30 13:51   ` [PATCH v9 36/41] btrfs: relocate block group to repair IO failure in ZONED Naohiro Aota
2020-10-30 13:51   ` [PATCH v9 37/41] btrfs: split alloc_log_tree() Naohiro Aota
2020-11-03 20:42     ` Josef Bacik
2020-11-03 22:10       ` Amy Parker
2020-11-10 11:12         ` Naohiro Aota
2020-10-30 13:51   ` [PATCH v9 38/41] btrfs: extend zoned allocator to use dedicated tree-log block group Naohiro Aota
2020-11-03 20:47     ` Josef Bacik
2020-11-10  6:37       ` Naohiro Aota
2020-10-30 13:51   ` [PATCH v9 39/41] btrfs: serialize log transaction on ZONED mode Naohiro Aota
2020-11-03 20:49     ` Josef Bacik
2020-10-30 13:51   ` [PATCH v9 40/41] btrfs: reorder log node allocation Naohiro Aota
2020-11-03 20:49     ` Josef Bacik
2020-10-30 13:51   ` [PATCH v9 41/41] btrfs: enable to mount ZONED incompat flag Naohiro Aota
2020-10-31  3:40   ` [PATCH v9 01/41] block: add bio_add_zone_append_page Jens Axboe
2020-11-02  5:15     ` Naohiro Aota
2020-11-02  8:24     ` Johannes Thumshirn
2020-11-03 11:54 ` [PATCH v9 00/41] btrfs: zoned block device support David Sterba

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).