diff options
author | Mike Snitzer <snitzer@kernel.org> | 2022-11-30 13:26:32 -0500 |
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committer | Mike Snitzer <snitzer@kernel.org> | 2022-12-01 11:42:45 -0500 |
commit | 352b837a5541690d4f843819028cf2b8be83d424 (patch) | |
tree | fcf79a3b8337c1ca65426f9dcdf3656c500184bb /drivers/md | |
parent | 8111964f1b8524c4bb56b02cd9c7a37725ea21fd (diff) | |
download | linux-stable-352b837a5541690d4f843819028cf2b8be83d424.tar.gz linux-stable-352b837a5541690d4f843819028cf2b8be83d424.tar.bz2 linux-stable-352b837a5541690d4f843819028cf2b8be83d424.zip |
dm cache: Fix ABBA deadlock between shrink_slab and dm_cache_metadata_abort
Same ABBA deadlock pattern fixed in commit 4b60f452ec51 ("dm thin: Fix
ABBA deadlock between shrink_slab and dm_pool_abort_metadata") to
DM-cache's metadata.
Reported-by: Zhihao Cheng <chengzhihao1@huawei.com>
Cc: stable@vger.kernel.org
Fixes: 028ae9f76f29 ("dm cache: add fail io mode and needs_check flag")
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Diffstat (limited to 'drivers/md')
-rw-r--r-- | drivers/md/dm-cache-metadata.c | 54 |
1 files changed, 47 insertions, 7 deletions
diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c index ab13b7380265..83a5975bcc72 100644 --- a/drivers/md/dm-cache-metadata.c +++ b/drivers/md/dm-cache-metadata.c @@ -551,11 +551,13 @@ static int __create_persistent_data_objects(struct dm_cache_metadata *cmd, return r; } -static void __destroy_persistent_data_objects(struct dm_cache_metadata *cmd) +static void __destroy_persistent_data_objects(struct dm_cache_metadata *cmd, + bool destroy_bm) { dm_sm_destroy(cmd->metadata_sm); dm_tm_destroy(cmd->tm); - dm_block_manager_destroy(cmd->bm); + if (destroy_bm) + dm_block_manager_destroy(cmd->bm); } typedef unsigned long (*flags_mutator)(unsigned long); @@ -826,7 +828,7 @@ static struct dm_cache_metadata *lookup_or_open(struct block_device *bdev, cmd2 = lookup(bdev); if (cmd2) { mutex_unlock(&table_lock); - __destroy_persistent_data_objects(cmd); + __destroy_persistent_data_objects(cmd, true); kfree(cmd); return cmd2; } @@ -874,7 +876,7 @@ void dm_cache_metadata_close(struct dm_cache_metadata *cmd) mutex_unlock(&table_lock); if (!cmd->fail_io) - __destroy_persistent_data_objects(cmd); + __destroy_persistent_data_objects(cmd, true); kfree(cmd); } } @@ -1807,14 +1809,52 @@ int dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd, bool *result) int dm_cache_metadata_abort(struct dm_cache_metadata *cmd) { - int r; + int r = -EINVAL; + struct dm_block_manager *old_bm = NULL, *new_bm = NULL; + + /* fail_io is double-checked with cmd->root_lock held below */ + if (unlikely(cmd->fail_io)) + return r; + + /* + * Replacement block manager (new_bm) is created and old_bm destroyed outside of + * cmd root_lock to avoid ABBA deadlock that would result (due to life-cycle of + * shrinker associated with the block manager's bufio client vs cmd root_lock). + * - must take shrinker_rwsem without holding cmd->root_lock + */ + new_bm = dm_block_manager_create(cmd->bdev, DM_CACHE_METADATA_BLOCK_SIZE << SECTOR_SHIFT, + CACHE_MAX_CONCURRENT_LOCKS); WRITE_LOCK(cmd); - __destroy_persistent_data_objects(cmd); - r = __create_persistent_data_objects(cmd, false); + if (cmd->fail_io) { + WRITE_UNLOCK(cmd); + goto out; + } + + __destroy_persistent_data_objects(cmd, false); + old_bm = cmd->bm; + if (IS_ERR(new_bm)) { + DMERR("could not create block manager during abort"); + cmd->bm = NULL; + r = PTR_ERR(new_bm); + goto out_unlock; + } + + cmd->bm = new_bm; + r = __open_or_format_metadata(cmd, false); + if (r) { + cmd->bm = NULL; + goto out_unlock; + } + new_bm = NULL; +out_unlock: if (r) cmd->fail_io = true; WRITE_UNLOCK(cmd); + dm_block_manager_destroy(old_bm); +out: + if (new_bm && !IS_ERR(new_bm)) + dm_block_manager_destroy(new_bm); return r; } |