1 files changed, 4 insertions, 1 deletions

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index f89396082544..b0352b5958a5 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -357,10 +357,13 @@ int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end)
 {
         struct extent_map *em;
         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+        u64 len = end - start + 1;
 
+        if (end == (u64)-1)
+                len = (u64)-1;
         while(1) {
                 spin_lock(&em_tree->lock);
-                em = lookup_extent_mapping(em_tree, start, end);
+                em = lookup_extent_mapping(em_tree, start, len);
                 if (!em) {
                         spin_unlock(&em_tree->lock);
                         break;