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| author | Mike Snitzer <snitzer@kernel.org> | 2024-05-20 13:34:06 -0400 |
|---|---|---|
| committer | Mike Snitzer <snitzer@kernel.org> | 2024-05-20 15:51:19 -0400 |
| commit | 825d8bbd2f32cb229c3b6653bd454832c3c20acb (patch) | |
| tree | d9ab547be7777d2d39f1bc3ba6b8597e99224130 /drivers/md/dm.c | |
| parent | 69381cf88a8dfa0ab27fb801b78be813e7e8fb80 (diff) | |
| download | lwn-825d8bbd2f32cb229c3b6653bd454832c3c20acb.tar.gz lwn-825d8bbd2f32cb229c3b6653bd454832c3c20acb.zip | |
dm: always manage discard support in terms of max_hw_discard_sectors
Commit 4f563a64732d ("block: add a max_user_discard_sectors queue
limit") changed block core to set max_discard_sectors to:
min(lim->max_hw_discard_sectors, lim->max_user_discard_sectors)
Since commit 1c0e720228ad ("dm: use queue_limits_set") it was reported
dm-thinp was failing in a few fstests (generic/347 and generic/405)
with the first WARN_ON_ONCE in dm_cell_key_has_valid_range() being
reported, e.g.:
WARNING: CPU: 1 PID: 30 at drivers/md/dm-bio-prison-v1.c:128 dm_cell_key_has_valid_range+0x3d/0x50
blk_set_stacking_limits() sets max_user_discard_sectors to UINT_MAX,
so given how block core now sets max_discard_sectors (detailed above)
it follows that blk_stack_limits() stacks up the underlying device's
max_hw_discard_sectors and max_discard_sectors is set to match it. If
max_hw_discard_sectors exceeds dm's BIO_PRISON_MAX_RANGE, then
dm_cell_key_has_valid_range() will trigger the warning with:
WARN_ON_ONCE(key->block_end - key->block_begin > BIO_PRISON_MAX_RANGE)
Aside from this warning, the discard will fail. Fix this and other DM
issues by governing discard support in terms of max_hw_discard_sectors
instead of max_discard_sectors.
Reported-by: Theodore Ts'o <tytso@mit.edu>
Fixes: 1c0e720228ad ("dm: use queue_limits_set")
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Diffstat (limited to 'drivers/md/dm.c')
| -rw-r--r-- | drivers/md/dm.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 7d0746b37c8e..3adfc6b83c01 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1086,7 +1086,7 @@ void disable_discard(struct mapped_device *md) struct queue_limits *limits = dm_get_queue_limits(md); /* device doesn't really support DISCARD, disable it */ - limits->max_discard_sectors = 0; + limits->max_hw_discard_sectors = 0; } void disable_write_zeroes(struct mapped_device *md) |