[PATCH 3.16.y-ckt 018/128] dm btree: fix leak of bufio-backed block in btree_split_sibling error path

From: Luis Henriques
Date: Sun Jan 24 2016 - 17:27:03 EST


3.16.7-ckt23 -stable review patch. If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Mike Snitzer <snitzer@xxxxxxxxxx>

commit 30ce6e1cc5a0f781d60227e9096c86e188d2c2bd upstream.

The block allocated at the start of btree_split_sibling() is never
released if later insert_at() fails.

Fix this by releasing the previously allocated bufio block using
unlock_block().

Reported-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
drivers/md/persistent-data/dm-btree.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/md/persistent-data/dm-btree.c b/drivers/md/persistent-data/dm-btree.c
index d6e47033b5e0..7ba85e2b146b 100644
--- a/drivers/md/persistent-data/dm-btree.c
+++ b/drivers/md/persistent-data/dm-btree.c
@@ -471,8 +471,10 @@ static int btree_split_sibling(struct shadow_spine *s, dm_block_t root,

r = insert_at(sizeof(__le64), pn, parent_index + 1,
le64_to_cpu(rn->keys[0]), &location);
- if (r)
+ if (r) {
+ unlock_block(s->info, right);
return r;
+ }

if (key < le64_to_cpu(rn->keys[0])) {
unlock_block(s->info, right);