1 files changed, 9 insertions, 1 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 941f1b71cd22..81ba6654c332 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -726,6 +726,15 @@ static noinline int cow_file_range(struct inode *inode,
         BUG_ON(disk_num_bytes >
                btrfs_super_total_bytes(&root->fs_info->super_copy));
 
+
+        read_lock(&BTRFS_I(inode)->extent_tree.lock);
+        em = search_extent_mapping(&BTRFS_I(inode)->extent_tree,
+                                   start, num_bytes);
+        if (em) {
+                alloc_hint = em->block_start;
+                free_extent_map(em);
+        }
+        read_unlock(&BTRFS_I(inode)->extent_tree.lock);
         btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
 
         while (disk_num_bytes > 0) {
@@ -738,7 +747,6 @@ static noinline int cow_file_range(struct inode *inode,
                 em = alloc_extent_map(GFP_NOFS);
                 em->start = start;
                 em->orig_start = em->start;
-
                 ram_size = ins.offset;
                 em->len = ins.offset;