From: John Garry <john.g.garry@oracle.com>
To: axboe@kernel.dk
Cc: linux-block@vger.kernel.org, hch@lst.de,
	martin.petersen@oracle.com, John Garry <john.g.garry@oracle.com>
Subject: [PATCH 2/2] block: Change blk_stack_atomic_writes_limits() unit_min check
Date: Thu,  9 Jan 2025 11:40:00 +0000	[thread overview]
Message-ID: <20250109114000.2299896-3-john.g.garry@oracle.com> (raw)
In-Reply-To: <20250109114000.2299896-1-john.g.garry@oracle.com>

The current check in blk_stack_atomic_writes_limits() for a bottom device
supporting atomic writes is to verify that limit atomic_write_unit_min is
non-zero.

This would cause a problem for device mapper queue limits calculation. This
is because it uses a temporary queue_limits structure to stack the limits,
before finally commiting the limits update.
The value of atomic_write_unit_min for the temporary queue_limits
structure is never evaluated and so cannot be used, so use limit
atomic_write_hw_unit_min.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: John Garry <john.g.garry@oracle.com>
---
 block/blk-settings.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/blk-settings.c b/block/blk-settings.c
index a8dd5c097b8a..d4fccd09e237 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -589,7 +589,7 @@ static void blk_stack_atomic_writes_limits(struct queue_limits *t,
 	if (!(t->features & BLK_FEAT_ATOMIC_WRITES_STACKED))
 		goto unsupported;
 
-	if (!b->atomic_write_unit_min)
+	if (!b->atomic_write_hw_unit_min)
 		goto unsupported;
 
 	if (!blk_atomic_write_start_sect_aligned(start, b))
-- 
2.31.1

next prev parent reply	other threads:[~2025-01-09 11:40 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-01-09 11:39 [PATCH 0/2] block: Stacked device atomic writes fixes John Garry
2025-01-09 11:39 ` [PATCH 1/2] block: Ensure start sector is aligned for stacking atomic writes John Garry
2025-01-09 11:40 ` John Garry [this message]
2025-01-10 21:51 ` [PATCH 0/2] block: Stacked device atomic writes fixes Martin K. Petersen
2025-01-15 16:42 ` John Garry
2025-01-16 14:13 ` Jens Axboe

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20250109114000.2299896-3-john.g.garry@oracle.com \
    --to=john.g.garry@oracle.com \
    --cc=axboe@kernel.dk \
    --cc=hch@lst.de \
    --cc=linux-block@vger.kernel.org \
    --cc=martin.petersen@oracle.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.