Btrfs: Fix delayed allocation to avoid missing delalloc extents

find_lock_delalloc_range could exit out too early

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 1e725a48467c..55b2e1426024 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -798,6 +798,7 @@ static int btrfs_cow_one_page(struct inode *inode, struct page *page,
         u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
         u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
 
+        WARN_ON(!PageLocked(page));
         set_page_extent_mapped(page);
 
         lock_extent(em_tree, page_start, page_end, GFP_NOFS);