Btrfs: fix double free in find_lock_delalloc_range

We need to NULL the cached_state after freeing it, otherwise
we might free it again if find_delalloc_range doesn't find anything.

Signed-off-by: Chris Mason <clm@fb.com>
cc: stable@vger.kernel.org

1 files changed, 1 insertions, 0 deletions

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 8285ed0464fa..0f425dea4523 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1693,6 +1693,7 @@ again:
                  * shortening the size of the delalloc range we're searching
                  */
                 free_extent_state(cached_state);
+                cached_state = NULL;
                 if (!loops) {
                         max_bytes = PAGE_CACHE_SIZE;
                         loops = 1;