1 files changed, 20 insertions, 4 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 0808f483dafa..38cda78de5e4 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5992,11 +5992,27 @@ unlock:
          * in the case of read we need to unlock only the end area that we
          * aren't using if there is any left over space.
          */
-        if (lockstart < lockend)
-                clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
-                                 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
-        else
+        if (lockstart < lockend) {
+                if (create && len < lockend - lockstart) {
+                        clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
+                                         lockstart + len - 1, unlock_bits, 1, 0,
+                                         &cached_state, GFP_NOFS);
+                        /*
+                         * Beside unlock, we also need to cleanup reserved space
+                         * for the left range by attaching EXTENT_DO_ACCOUNTING.
+                         */
+                        clear_extent_bit(&BTRFS_I(inode)->io_tree,
+                                         lockstart + len, lockend,
+                                         unlock_bits | EXTENT_DO_ACCOUNTING,
+                                         1, 0, NULL, GFP_NOFS);
+                } else {
+                        clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
+                                         lockend, unlock_bits, 1, 0,
+                                         &cached_state, GFP_NOFS);
+                }
+        } else {
                 free_extent_state(cached_state);
+        }
 
         free_extent_map(em);