* resend: zeroout fixes
@ 2016-07-19 9:23 Christoph Hellwig
2016-07-19 9:23 ` [PATCH 1/2] block: introduce BLKDEV_DISCARD_ZERO to fix zeroout Christoph Hellwig
` (2 more replies)
0 siblings, 3 replies; 5+ messages in thread
From: Christoph Hellwig @ 2016-07-19 9:23 UTC (permalink / raw)
To: axboe; +Cc: shli, martin.petersen, snitzer, sitsofe, linux-block
The first one is a repost of my BLKDEV_DISCARD_ZERO with the spelling
fixes suggest from Martin, the second one just drops the -EOPNOTSUPP
special casing in blkdev_issue_write_same.
Note that the patches are against the block for-next tree, and
unfortunately we have diverged significantly from 4.7 in this area:
4.7 has the missing bio_put for the sumbmit_bio_wait callers, and
4.8 has the various req_op changes, including a new calling
convention for __blkdev_issue_zeroout. I'm not sure how to best
sort this mess out, but I really think we need the bio_put in the
for-4.8 tree as well, and we should probably bring the changed
__blkdev_issue_discard calling convention into 4.7 as well.
Suggestion for how to best handle this?
Compared to the last posting on June 24th this just adds the Reviewed-by:
tags from Martin.
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH 1/2] block: introduce BLKDEV_DISCARD_ZERO to fix zeroout
2016-07-19 9:23 resend: zeroout fixes Christoph Hellwig
@ 2016-07-19 9:23 ` Christoph Hellwig
2016-07-19 9:23 ` [PATCH 2/2] block: don't ignore -EOPNOTSUPP blkdev_issue_write_same Christoph Hellwig
2016-07-20 23:36 ` resend: zeroout fixes Jens Axboe
2 siblings, 0 replies; 5+ messages in thread
From: Christoph Hellwig @ 2016-07-19 9:23 UTC (permalink / raw)
To: axboe; +Cc: shli, martin.petersen, snitzer, sitsofe, linux-block
Currently blkdev_issue_zeroout cascades down from discards (if the driver
guarantees that discards zero data), to WRITE SAME and then to a loop
writing zeroes. Unfortunately we ignore run-time EOPNOTSUPP errors in the
block layer blkdev_issue_discard helper to work around DM volumes that
may have mixed discard support underneath.
This patch intoroduces a new BLKDEV_DISCARD_ZERO flag to
blkdev_issue_discard that indicates we are called for zeroing operation.
This allows both to ignore the EOPNOTSUPP hack and actually consolidating
the discard_zeroes_data check into the function.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
---
block/blk-lib.c | 17 +++++++++++------
include/linux/blkdev.h | 4 +++-
2 files changed, 14 insertions(+), 7 deletions(-)
diff --git a/block/blk-lib.c b/block/blk-lib.c
index 78626c2..45b35b1 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -36,12 +36,17 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
return -ENXIO;
if (flags & BLKDEV_DISCARD_SECURE) {
+ if (flags & BLKDEV_DISCARD_ZERO)
+ return -EOPNOTSUPP;
if (!blk_queue_secure_erase(q))
return -EOPNOTSUPP;
op = REQ_OP_SECURE_ERASE;
} else {
if (!blk_queue_discard(q))
return -EOPNOTSUPP;
+ if ((flags & BLKDEV_DISCARD_ZERO) &&
+ !q->limits.discard_zeroes_data)
+ return -EOPNOTSUPP;
op = REQ_OP_DISCARD;
}
@@ -116,7 +121,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
&bio);
if (!ret && bio) {
ret = submit_bio_wait(bio);
- if (ret == -EOPNOTSUPP)
+ if (ret == -EOPNOTSUPP && !(flags & BLKDEV_DISCARD_ZERO))
ret = 0;
}
blk_finish_plug(&plug);
@@ -241,11 +246,11 @@ static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
sector_t nr_sects, gfp_t gfp_mask, bool discard)
{
- struct request_queue *q = bdev_get_queue(bdev);
-
- if (discard && blk_queue_discard(q) && q->limits.discard_zeroes_data &&
- blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, 0) == 0)
- return 0;
+ if (discard) {
+ if (!blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask,
+ BLKDEV_DISCARD_ZERO))
+ return 0;
+ }
if (bdev_write_same(bdev) &&
blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask,
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 9ae49cc..03fa3d1 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1136,7 +1136,9 @@ static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
return bqt->tag_index[tag];
}
-#define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */
+
+#define BLKDEV_DISCARD_SECURE (1 << 0) /* issue a secure erase */
+#define BLKDEV_DISCARD_ZERO (1 << 1) /* must reliably zero data */
extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
--
2.1.4
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH 2/2] block: don't ignore -EOPNOTSUPP blkdev_issue_write_same
2016-07-19 9:23 resend: zeroout fixes Christoph Hellwig
2016-07-19 9:23 ` [PATCH 1/2] block: introduce BLKDEV_DISCARD_ZERO to fix zeroout Christoph Hellwig
@ 2016-07-19 9:23 ` Christoph Hellwig
2016-07-20 23:36 ` resend: zeroout fixes Jens Axboe
2 siblings, 0 replies; 5+ messages in thread
From: Christoph Hellwig @ 2016-07-19 9:23 UTC (permalink / raw)
To: axboe; +Cc: shli, martin.petersen, snitzer, sitsofe, linux-block
WRITE SAME is a data integrity operation and we can't simply ignore
errors.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
---
block/blk-lib.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/blk-lib.c b/block/blk-lib.c
index 45b35b1..e371f83 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -178,7 +178,7 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
if (bio)
ret = submit_bio_wait(bio);
- return ret != -EOPNOTSUPP ? ret : 0;
+ return ret;
}
EXPORT_SYMBOL(blkdev_issue_write_same);
--
2.1.4
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: resend: zeroout fixes
2016-07-19 9:23 resend: zeroout fixes Christoph Hellwig
2016-07-19 9:23 ` [PATCH 1/2] block: introduce BLKDEV_DISCARD_ZERO to fix zeroout Christoph Hellwig
2016-07-19 9:23 ` [PATCH 2/2] block: don't ignore -EOPNOTSUPP blkdev_issue_write_same Christoph Hellwig
@ 2016-07-20 23:36 ` Jens Axboe
2016-07-21 5:47 ` Christoph Hellwig
2 siblings, 1 reply; 5+ messages in thread
From: Jens Axboe @ 2016-07-20 23:36 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: shli, martin.petersen, snitzer, sitsofe, linux-block
On 07/19/2016 03:23 AM, Christoph Hellwig wrote:
> The first one is a repost of my BLKDEV_DISCARD_ZERO with the spelling
> fixes suggest from Martin, the second one just drops the -EOPNOTSUPP
> special casing in blkdev_issue_write_same.
>
> Note that the patches are against the block for-next tree, and
> unfortunately we have diverged significantly from 4.7 in this area:
> 4.7 has the missing bio_put for the sumbmit_bio_wait callers, and
> 4.8 has the various req_op changes, including a new calling
> convention for __blkdev_issue_zeroout. I'm not sure how to best
> sort this mess out, but I really think we need the bio_put in the
> for-4.8 tree as well, and we should probably bring the changed
> __blkdev_issue_discard calling convention into 4.7 as well.
> Suggestion for how to best handle this?
I think we should leave 4.7 as-is. The put issue being fixed is the most
important one, so just roll a separate 4.8 patch for that.
--
Jens Axboe
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: resend: zeroout fixes
2016-07-20 23:36 ` resend: zeroout fixes Jens Axboe
@ 2016-07-21 5:47 ` Christoph Hellwig
0 siblings, 0 replies; 5+ messages in thread
From: Christoph Hellwig @ 2016-07-21 5:47 UTC (permalink / raw)
To: Jens Axboe
Cc: Christoph Hellwig, shli, martin.petersen, snitzer, sitsofe, linux-block
On Wed, Jul 20, 2016 at 05:36:32PM -0600, Jens Axboe wrote:
> I think we should leave 4.7 as-is. The put issue being fixed is the most
> important one, so just roll a separate 4.8 patch for that.
Ok, in that case just merge this series as-is for now.
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2016-07-21 5:47 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2016-07-19 9:23 resend: zeroout fixes Christoph Hellwig
2016-07-19 9:23 ` [PATCH 1/2] block: introduce BLKDEV_DISCARD_ZERO to fix zeroout Christoph Hellwig
2016-07-19 9:23 ` [PATCH 2/2] block: don't ignore -EOPNOTSUPP blkdev_issue_write_same Christoph Hellwig
2016-07-20 23:36 ` resend: zeroout fixes Jens Axboe
2016-07-21 5:47 ` Christoph Hellwig
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