On 25/08/2025 09:33, Zhang Yi wrote:
From: Zhang Yi <yi.zhang@xxxxxxxxxx>
The parameter max_hw_wzeroes_unmap_sectors in queue_limits should be
equal to max_write_zeroes_sectors if it is set to a non-zero value.
However, the stacked md drivers call md_init_stacking_limits() to
initialize this parameter to UINT_MAX but only adjust
max_write_zeroes_sectors when setting limits. Therefore, this
discrepancy triggers a value check failure in blk_validate_limits().
Fix this failure by explicitly setting max_hw_wzeroes_unmap_sectors to
zero.
Fixes: 0c40d7cb5ef3 ("block: introduce max_{hw|user}_wzeroes_unmap_sectors to queue limits")
Reported-by: John Garry <john.g.garry@xxxxxxxxxx>
Closes: https://lore.kernel.org/linux-block/803a2183-a0bb-4b7a-92f1-afc5097630d2@xxxxxxxxxx/
Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx>
Tested-by: John Garry <john.g.garry@xxxxxxxxxx> # raid 0/1/10
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index f1d8811a542a..419139ad7663 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -382,6 +382,7 @@ static int raid0_set_limits(struct mddev *mddev)
md_init_stacking_limits(&lim);
lim.max_hw_sectors = mddev->chunk_sectors;
lim.max_write_zeroes_sectors = mddev->chunk_sectors;
+ lim.max_hw_wzeroes_unmap_sectors = mddev->chunk_sectors;
lim.io_min = mddev->chunk_sectors << 9;
lim.io_opt = lim.io_min * mddev->raid_disks;
lim.chunk_sectors = mddev->chunk_sectors;
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 408c26398321..35c6498b4917 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -3211,6 +3211,7 @@ static int raid1_set_limits(struct mddev *mddev)
md_init_stacking_limits(&lim);
lim.max_write_zeroes_sectors = 0;
+ lim.max_hw_wzeroes_unmap_sectors = 0;
It would be better if we documented why we cannot support this on
raid1/10, yet we can on raid0.
I am looking through the history of why max_write_zeroes_sectors is set
to zero. I have gone as far back as 5026d7a9b, and this tells us that
the retry mechanism for WRITE SAME causes an issue where mirrors are
offlined (and so we disabled the support); and this was simply copied
for write zeroes in 3deff1a70.
