diff options
| author | Li Lingfeng <lilingfeng3@huawei.com> | 2023-06-05 10:03:16 +0300 |
|---|---|---|
| committer | Mike Snitzer <snitzer@kernel.org> | 2023-06-17 01:24:13 +0300 |
| commit | d48300120627a1cb98914738fff38b424625b8ad (patch) | |
| tree | 7aff29771ae267e9f0d7110b55c61c6a2012c360 /include/linux/dm-bufio.h | |
| parent | 2a32897c840be1c0a0525f4279b365781acfba24 (diff) | |
| download | linux-d48300120627a1cb98914738fff38b424625b8ad.tar.xz | |
dm thin metadata: Fix ABBA deadlock by resetting dm_bufio_client
As described in commit 8111964f1b85 ("dm thin: Fix ABBA deadlock between
shrink_slab and dm_pool_abort_metadata"), ABBA deadlocks will be
triggered because shrinker_rwsem currently needs to held by
dm_pool_abort_metadata() as a side-effect of thin-pool metadata
operation failure.
The following three problem scenarios have been noticed:
1) Described by commit 8111964f1b85 ("dm thin: Fix ABBA deadlock between
shrink_slab and dm_pool_abort_metadata")
2) shrinker_rwsem and throttle->lock
P1(drop cache) P2(kworker)
drop_caches_sysctl_handler
drop_slab
shrink_slab
down_read(&shrinker_rwsem) - LOCK A
do_shrink_slab
super_cache_scan
prune_icache_sb
dispose_list
evict
ext4_evict_inode
ext4_clear_inode
ext4_discard_preallocations
ext4_mb_load_buddy_gfp
ext4_mb_init_cache
ext4_wait_block_bitmap
__ext4_error
ext4_handle_error
ext4_commit_super
...
dm_submit_bio
do_worker
throttle_work_update
down_write(&t->lock) -- LOCK B
process_deferred_bios
commit
metadata_operation_failed
dm_pool_abort_metadata
dm_block_manager_create
dm_bufio_client_create
register_shrinker
down_write(&shrinker_rwsem)
-- LOCK A
thin_map
thin_bio_map
thin_defer_bio_with_throttle
throttle_lock
down_read(&t->lock) - LOCK B
3) shrinker_rwsem and wait_on_buffer
P1(drop cache) P2(kworker)
drop_caches_sysctl_handler
drop_slab
shrink_slab
down_read(&shrinker_rwsem) - LOCK A
do_shrink_slab
...
ext4_wait_block_bitmap
__ext4_error
ext4_handle_error
jbd2_journal_abort
jbd2_journal_update_sb_errno
jbd2_write_superblock
submit_bh
// LOCK B
// RELEASE B
do_worker
throttle_work_update
down_write(&t->lock) - LOCK B
process_deferred_bios
process_bio
commit
metadata_operation_failed
dm_pool_abort_metadata
dm_block_manager_create
dm_bufio_client_create
register_shrinker
register_shrinker_prepared
down_write(&shrinker_rwsem) - LOCK A
bio_endio
wait_on_buffer
__wait_on_buffer
Fix these by resetting dm_bufio_client without holding shrinker_rwsem.
Fixes: 8111964f1b85 ("dm thin: Fix ABBA deadlock between shrink_slab and dm_pool_abort_metadata")
Cc: stable@vger.kernel.org
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Diffstat (limited to 'include/linux/dm-bufio.h')
| -rw-r--r-- | include/linux/dm-bufio.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/dm-bufio.h b/include/linux/dm-bufio.h index 681656a1c03d..75e7d8cbb532 100644 --- a/include/linux/dm-bufio.h +++ b/include/linux/dm-bufio.h @@ -38,6 +38,8 @@ dm_bufio_client_create(struct block_device *bdev, unsigned int block_size, */ void dm_bufio_client_destroy(struct dm_bufio_client *c); +void dm_bufio_client_reset(struct dm_bufio_client *c); + /* * Set the sector range. * When this function is called, there must be no I/O in progress on the bufio |