btrfs: stop locking the source extent range during reflink

[sfrench/cifs-2.6.git] / fs / btrfs / relocation.c

diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 21ba5f0bcc4437b20b0651ee04e6f63768f47737..5c9ef6717f8450456ec076ef1fce5215f0fd8809 100644 (file)
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -1127,16 +1127,22 @@ int replace_file_extents(struct btrfs_trans_handle *trans,
                                                    fs_info->sectorsize));
                                WARN_ON(!IS_ALIGNED(end, fs_info->sectorsize));
                                end--;
+                               /* Take mmap lock to serialize with reflinks. */
+                               if (!down_read_trylock(&BTRFS_I(inode)->i_mmap_lock))
+                                       continue;
                                ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
                                                      key.offset, end,
                                                      &cached_state);
-                               if (!ret)
+                               if (!ret) {
+                                       up_read(&BTRFS_I(inode)->i_mmap_lock);
                                        continue;
+                               }
 
                                btrfs_drop_extent_map_range(BTRFS_I(inode),
                                                            key.offset, end, true);
                                unlock_extent(&BTRFS_I(inode)->io_tree,
                                              key.offset, end, &cached_state);
+                               up_read(&BTRFS_I(inode)->i_mmap_lock);
                        }
                }