kernel/linux.git/drivers/md/dm-snap.c, branch v6.18.21

dm-snapshot: fix 'scheduling while atomic' on real-time kernels

2026-01-17T15:35:16+00:00

[ Upstream commit 8581b19eb2c5ccf06c195d3b5468c3c9d17a5020 ] There is reported 'scheduling while atomic' bug when using dm-snapshot on real-time kernels. The reason for the bug is that the hlist_bl code does preempt_disable() when taking the lock and the kernel attempts to take other spinlocks while holding the hlist_bl lock. Fix this by converting a hlist_bl spinlock into a regular spinlock. Signed-off-by: Mikulas Patocka Reported-by: Jiping Ma Signed-off-by: Sasha Levin

dm: always manage discard support in terms of max_hw_discard_sectors

2024-05-20T19:51:19+00:00

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 Fixes: 1c0e720228ad ("dm: use queue_limits_set") Signed-off-by: Mike Snitzer

dm snapshot: fix lockup in dm_exception_table_exit

2024-03-20T18:31:24+00:00

There was reported lockup when we exit a snapshot with many exceptions. Fix this by adding "cond_resched" to the loop that frees the exceptions. Reported-by: John Pittman Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer

block: replace fmode_t with a block-specific type for block open flags

2023-06-12T14:04:05+00:00

The only overlap between the block open flags mapped into the fmode_t and other uses of fmode_t are FMODE_READ and FMODE_WRITE. Define a new blk_mode_t instead for use in blkdev_get_by_{dev,path}, ->open and ->ioctl and stop abusing fmode_t. Signed-off-by: Christoph Hellwig Acked-by: Jack Wang [rnbd] Reviewed-by: Hannes Reinecke Reviewed-by: Christian Brauner Link: https://lore.kernel.org/r/20230608110258.189493-28-hch@lst.de Signed-off-by: Jens Axboe

dm-snap: simplify the origin_dev == cow_dev check in snapshot_ctr

2023-06-05T16:57:40+00:00

Use the block_device acquired in dm_get_device for the check instead of doing an extra lookup. Signed-off-by: Christoph Hellwig Reviewed-by: Mike Snitzer Link: https://lore.kernel.org/r/20230531125535.676098-18-hch@lst.de Signed-off-by: Jens Axboe

dm: push error reporting down to dm_register_target()

2023-04-11T16:01:01+00:00

Simplifies each DM target's init method by making dm_register_target() responsible for its error reporting (on behalf of targets). Signed-off-by: Yangtao Li Signed-off-by: Mike Snitzer

dm: avoid split of quoted strings where possible

2023-02-14T19:23:07+00:00

Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer

dm: add missing empty lines

2023-02-14T19:23:06+00:00

Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer

dm: avoid spaces before function arguments or in favour of tabs

2023-02-14T19:23:06+00:00

Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer

dm: fix trailing statements

2023-02-14T19:23:06+00:00

Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer