diff options
author | Li Lingfeng <lilingfeng3@huawei.com> | 2023-06-05 09:03:16 +0200 |
---|---|---|
committer | Mike Snitzer <snitzer@kernel.org> | 2023-06-17 00:24:13 +0200 |
commit | d48300120627a1cb98914738fff38b424625b8ad (patch) | |
tree | 7aff29771ae267e9f0d7110b55c61c6a2012c360 /drivers/md | |
parent | dm crypt: fix crypt_ctr_cipher_new return value on invalid AEAD cipher (diff) | |
download | linux-d48300120627a1cb98914738fff38b424625b8ad.tar.xz linux-d48300120627a1cb98914738fff38b424625b8ad.zip |
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 'drivers/md')
-rw-r--r-- | drivers/md/dm-bufio.c | 7 | ||||
-rw-r--r-- | drivers/md/dm-thin-metadata.c | 58 | ||||
-rw-r--r-- | drivers/md/persistent-data/dm-block-manager.c | 6 | ||||
-rw-r--r-- | drivers/md/persistent-data/dm-block-manager.h | 1 | ||||
-rw-r--r-- | drivers/md/persistent-data/dm-space-map.h | 3 | ||||
-rw-r--r-- | drivers/md/persistent-data/dm-transaction-manager.c | 3 |
6 files changed, 44 insertions, 34 deletions
diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c index eea977662e81..a7079b38756a 100644 --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -2592,6 +2592,13 @@ void dm_bufio_client_destroy(struct dm_bufio_client *c) } EXPORT_SYMBOL_GPL(dm_bufio_client_destroy); +void dm_bufio_client_reset(struct dm_bufio_client *c) +{ + drop_buffers(c); + flush_work(&c->shrink_work); +} +EXPORT_SYMBOL_GPL(dm_bufio_client_reset); + void dm_bufio_set_sector_offset(struct dm_bufio_client *c, sector_t start) { c->start = start; diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c index 9f5cb52c5763..63d92d388ee6 100644 --- a/drivers/md/dm-thin-metadata.c +++ b/drivers/md/dm-thin-metadata.c @@ -603,6 +603,8 @@ static int __format_metadata(struct dm_pool_metadata *pmd) r = dm_tm_create_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION, &pmd->tm, &pmd->metadata_sm); if (r < 0) { + pmd->tm = NULL; + pmd->metadata_sm = NULL; DMERR("tm_create_with_sm failed"); return r; } @@ -611,6 +613,7 @@ static int __format_metadata(struct dm_pool_metadata *pmd) if (IS_ERR(pmd->data_sm)) { DMERR("sm_disk_create failed"); r = PTR_ERR(pmd->data_sm); + pmd->data_sm = NULL; goto bad_cleanup_tm; } @@ -641,11 +644,15 @@ static int __format_metadata(struct dm_pool_metadata *pmd) bad_cleanup_nb_tm: dm_tm_destroy(pmd->nb_tm); + pmd->nb_tm = NULL; bad_cleanup_data_sm: dm_sm_destroy(pmd->data_sm); + pmd->data_sm = NULL; bad_cleanup_tm: dm_tm_destroy(pmd->tm); + pmd->tm = NULL; dm_sm_destroy(pmd->metadata_sm); + pmd->metadata_sm = NULL; return r; } @@ -711,6 +718,8 @@ static int __open_metadata(struct dm_pool_metadata *pmd) sizeof(disk_super->metadata_space_map_root), &pmd->tm, &pmd->metadata_sm); if (r < 0) { + pmd->tm = NULL; + pmd->metadata_sm = NULL; DMERR("tm_open_with_sm failed"); goto bad_unlock_sblock; } @@ -720,6 +729,7 @@ static int __open_metadata(struct dm_pool_metadata *pmd) if (IS_ERR(pmd->data_sm)) { DMERR("sm_disk_open failed"); r = PTR_ERR(pmd->data_sm); + pmd->data_sm = NULL; goto bad_cleanup_tm; } @@ -746,9 +756,12 @@ static int __open_metadata(struct dm_pool_metadata *pmd) bad_cleanup_data_sm: dm_sm_destroy(pmd->data_sm); + pmd->data_sm = NULL; bad_cleanup_tm: dm_tm_destroy(pmd->tm); + pmd->tm = NULL; dm_sm_destroy(pmd->metadata_sm); + pmd->metadata_sm = NULL; bad_unlock_sblock: dm_bm_unlock(sblock); @@ -795,9 +808,13 @@ static void __destroy_persistent_data_objects(struct dm_pool_metadata *pmd, bool destroy_bm) { dm_sm_destroy(pmd->data_sm); + pmd->data_sm = NULL; dm_sm_destroy(pmd->metadata_sm); + pmd->metadata_sm = NULL; dm_tm_destroy(pmd->nb_tm); + pmd->nb_tm = NULL; dm_tm_destroy(pmd->tm); + pmd->tm = NULL; if (destroy_bm) dm_block_manager_destroy(pmd->bm); } @@ -1005,8 +1022,7 @@ int dm_pool_metadata_close(struct dm_pool_metadata *pmd) __func__, r); } pmd_write_unlock(pmd); - if (!pmd->fail_io) - __destroy_persistent_data_objects(pmd, true); + __destroy_persistent_data_objects(pmd, true); kfree(pmd); return 0; @@ -1877,53 +1893,29 @@ static void __set_abort_with_changes_flags(struct dm_pool_metadata *pmd) int dm_pool_abort_metadata(struct dm_pool_metadata *pmd) { int r = -EINVAL; - struct dm_block_manager *old_bm = NULL, *new_bm = NULL; /* fail_io is double-checked with pmd->root_lock held below */ if (unlikely(pmd->fail_io)) return r; - /* - * Replacement block manager (new_bm) is created and old_bm destroyed outside of - * pmd root_lock to avoid ABBA deadlock that would result (due to life-cycle of - * shrinker associated with the block manager's bufio client vs pmd root_lock). - * - must take shrinker_mutex without holding pmd->root_lock - */ - new_bm = dm_block_manager_create(pmd->bdev, THIN_METADATA_BLOCK_SIZE << SECTOR_SHIFT, - THIN_MAX_CONCURRENT_LOCKS); - pmd_write_lock(pmd); if (pmd->fail_io) { pmd_write_unlock(pmd); - goto out; + return r; } - __set_abort_with_changes_flags(pmd); + + /* destroy data_sm/metadata_sm/nb_tm/tm */ __destroy_persistent_data_objects(pmd, false); - old_bm = pmd->bm; - if (IS_ERR(new_bm)) { - DMERR("could not create block manager during abort"); - pmd->bm = NULL; - r = PTR_ERR(new_bm); - goto out_unlock; - } - pmd->bm = new_bm; + /* reset bm */ + dm_block_manager_reset(pmd->bm); + + /* rebuild data_sm/metadata_sm/nb_tm/tm */ r = __open_or_format_metadata(pmd, false); - if (r) { - pmd->bm = NULL; - goto out_unlock; - } - new_bm = NULL; -out_unlock: if (r) pmd->fail_io = true; pmd_write_unlock(pmd); - dm_block_manager_destroy(old_bm); -out: - if (new_bm && !IS_ERR(new_bm)) - dm_block_manager_destroy(new_bm); - return r; } diff --git a/drivers/md/persistent-data/dm-block-manager.c b/drivers/md/persistent-data/dm-block-manager.c index 7bdfc23f758a..0e010e1204aa 100644 --- a/drivers/md/persistent-data/dm-block-manager.c +++ b/drivers/md/persistent-data/dm-block-manager.c @@ -421,6 +421,12 @@ void dm_block_manager_destroy(struct dm_block_manager *bm) } EXPORT_SYMBOL_GPL(dm_block_manager_destroy); +void dm_block_manager_reset(struct dm_block_manager *bm) +{ + dm_bufio_client_reset(bm->bufio); +} +EXPORT_SYMBOL_GPL(dm_block_manager_reset); + unsigned int dm_bm_block_size(struct dm_block_manager *bm) { return dm_bufio_get_block_size(bm->bufio); diff --git a/drivers/md/persistent-data/dm-block-manager.h b/drivers/md/persistent-data/dm-block-manager.h index 5746b0f82a03..f706d3de8d5a 100644 --- a/drivers/md/persistent-data/dm-block-manager.h +++ b/drivers/md/persistent-data/dm-block-manager.h @@ -36,6 +36,7 @@ struct dm_block_manager *dm_block_manager_create( struct block_device *bdev, unsigned int block_size, unsigned int max_held_per_thread); void dm_block_manager_destroy(struct dm_block_manager *bm); +void dm_block_manager_reset(struct dm_block_manager *bm); unsigned int dm_bm_block_size(struct dm_block_manager *bm); dm_block_t dm_bm_nr_blocks(struct dm_block_manager *bm); diff --git a/drivers/md/persistent-data/dm-space-map.h b/drivers/md/persistent-data/dm-space-map.h index dab490353781..6bf69922b5ad 100644 --- a/drivers/md/persistent-data/dm-space-map.h +++ b/drivers/md/persistent-data/dm-space-map.h @@ -77,7 +77,8 @@ struct dm_space_map { static inline void dm_sm_destroy(struct dm_space_map *sm) { - sm->destroy(sm); + if (sm) + sm->destroy(sm); } static inline int dm_sm_extend(struct dm_space_map *sm, dm_block_t extra_blocks) diff --git a/drivers/md/persistent-data/dm-transaction-manager.c b/drivers/md/persistent-data/dm-transaction-manager.c index 6dc016248baf..c88fa6266203 100644 --- a/drivers/md/persistent-data/dm-transaction-manager.c +++ b/drivers/md/persistent-data/dm-transaction-manager.c @@ -199,6 +199,9 @@ EXPORT_SYMBOL_GPL(dm_tm_create_non_blocking_clone); void dm_tm_destroy(struct dm_transaction_manager *tm) { + if (!tm) + return; + if (!tm->is_clone) wipe_shadow_table(tm); |