dm btree: fix leak of bufio-backed block in btree_split_beneath error path

commit 4dcb8b57df3593dcb20481d9d6cf79d1dc1534be upstream.

btree_split_beneath()'s error path had an outstanding FIXME that speaks
directly to the potential for _not_ cleaning up a previously allocated
bufio-backed block.

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

Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <thornber@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/md/persistent-data/dm-btree.c b/drivers/md/persistent-data/dm-btree.c
index 62f297a44dd5a7ddafc183e1ab88e41f1ac78951..29e423f6bfa586e695f502face98dfbff3f8db26 100644 (file)
--- a/drivers/md/persistent-data/dm-btree.c
+++ b/drivers/md/persistent-data/dm-btree.c
@@ -503,7 +503,7 @@ static int btree_split_beneath(struct shadow_spine *s, uint64_t key)
 
        r = new_block(s->info, &right);
        if (r < 0) {
-               /* FIXME: put left */
+               unlock_block(s->info, left);
                return r;
        }