From 10add84e276432d9dd8044679a1028dd4084117e Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Fri, 5 May 2017 14:40:13 -0400 Subject: dm cache metadata: fail operations if fail_io mode has been established Otherwise it is possible to trigger crashes due to the metadata being inaccessible yet these methods don't safely account for that possibility without these checks. Cc: stable@vger.kernel.org Reported-by: Mikulas Patocka Signed-off-by: Mike Snitzer --- drivers/md/dm-cache-metadata.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c index 8568dbd50ba4..4a4e9c75fc4c 100644 --- a/drivers/md/dm-cache-metadata.c +++ b/drivers/md/dm-cache-metadata.c @@ -1624,17 +1624,19 @@ void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd, int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown) { - int r; + int r = -EINVAL; flags_mutator mutator = (clean_shutdown ? set_clean_shutdown : clear_clean_shutdown); WRITE_LOCK(cmd); + if (cmd->fail_io) + goto out; + r = __commit_transaction(cmd, mutator); if (r) goto out; r = __begin_transaction(cmd); - out: WRITE_UNLOCK(cmd); return r; @@ -1646,7 +1648,8 @@ int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata *cmd, int r = -EINVAL; READ_LOCK(cmd); - r = dm_sm_get_nr_free(cmd->metadata_sm, result); + if (!cmd->fail_io) + r = dm_sm_get_nr_free(cmd->metadata_sm, result); READ_UNLOCK(cmd); return r; @@ -1658,7 +1661,8 @@ int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd, int r = -EINVAL; READ_LOCK(cmd); - r = dm_sm_get_nr_blocks(cmd->metadata_sm, result); + if (!cmd->fail_io) + r = dm_sm_get_nr_blocks(cmd->metadata_sm, result); READ_UNLOCK(cmd); return r; -- cgit v1.2.3