dm btree: fix bufio buffer leaks in dm_btree_del() error path

commit ed8b45a3679eb49069b094c0711b30833f27c734 upstream.

If dm_btree_del()'s call to push_frame() fails, e.g. due to
btree_node_validator finding invalid metadata, the dm_btree_del() error
path must unlock all frames (which have active dm-bufio buffers) that
were pushed onto the del_stack.

Otherwise, dm_bufio_client_destroy() will BUG_ON() because dm-bufio
buffers have leaked, e.g.:
  device-mapper: bufio: leaked buffer 3, hold count 1, list 0

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
This commit is contained in:
Joe Thornber 2015-12-10 14:37:53 +00:00 committed by Zefan Li
parent 322d37f032
commit d8e33a2789

View file

@ -230,6 +230,16 @@ static void pop_frame(struct del_stack *s)
dm_tm_unlock(s->tm, f->b);
}
static void unlock_all_frames(struct del_stack *s)
{
struct frame *f;
while (unprocessed_frames(s)) {
f = s->spine + s->top--;
dm_tm_unlock(s->tm, f->b);
}
}
int dm_btree_del(struct dm_btree_info *info, dm_block_t root)
{
int r;
@ -285,9 +295,13 @@ int dm_btree_del(struct dm_btree_info *info, dm_block_t root)
f->current_child = f->nr_children;
}
}
out:
if (r) {
/* cleanup all frames of del_stack */
unlock_all_frames(s);
}
kfree(s);
return r;
}
EXPORT_SYMBOL_GPL(dm_btree_del);