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

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@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/md/persistent-data/dm-btree.c b/drivers/md/persistent-data/dm-btree.c
index 0e09aef43998ac250cc296122247875eed23ceb2..88c287db3bde6d56e0bb7ac9dbc2467dd2377987 100644 (file)
--- 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, unsigned parent_index,
 
        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);