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authorJoe Thornber <ejt@redhat.com>2015-10-09 14:03:38 +0100
committerMike Snitzer <snitzer@redhat.com>2015-10-09 09:16:29 -0400
commit2bffa1503c5c06192eb1459180fac4416575a966 (patch)
tree6d14a28ef23e4633451ca5fb39ee54f0e7d4776b
parent50887bd139b83ce4489ed865a04bf1be5559c4ad (diff)
dm cache: fix NULL pointer when switching from cleaner policy
The cleaner policy doesn't make use of the per cache block hint space in the metadata (unlike the other policies). When switching from the cleaner policy to mq or smq a NULL pointer crash (in dm_tm_new_block) was observed. The crash was caused by bugs in dm-cache-metadata.c when trying to skip creation of the hint btree. The minimal fix is to change hint size for the cleaner policy to 4 bytes (only hint size supported). Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
-rw-r--r--drivers/md/dm-cache-policy-cleaner.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/md/dm-cache-policy-cleaner.c b/drivers/md/dm-cache-policy-cleaner.c
index 240c9f0e85e7..8a096456579b 100644
--- a/drivers/md/dm-cache-policy-cleaner.c
+++ b/drivers/md/dm-cache-policy-cleaner.c
@@ -436,7 +436,7 @@ static struct dm_cache_policy *wb_create(dm_cblock_t cache_size,
static struct dm_cache_policy_type wb_policy_type = {
.name = "cleaner",
.version = {1, 0, 0},
- .hint_size = 0,
+ .hint_size = 4,
.owner = THIS_MODULE,
.create = wb_create
};