4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Mike Snitzer <snitzer@xxxxxxxxxx>
commit 10add84e276432d9dd8044679a1028dd4084117e upstream.
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.
Reported-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/dm-cache-metadata.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
--- a/drivers/md/dm-cache-metadata.c
+++ b/drivers/md/dm-cache-metadata.c
@@ -1326,17 +1326,19 @@ void dm_cache_metadata_set_stats(struct
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;
@@ -1348,7 +1350,8 @@ int dm_cache_get_free_metadata_block_cou
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;
@@ -1360,7 +1363,8 @@ int dm_cache_get_metadata_dev_size(struc
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;