diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index 6b6fdc6..f84f505 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -80,4 +80,5 @@
 			     struct btrfs_fs_info *fs_info);
 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
 			     struct btrfs_fs_info *fs_info);
+int btree_lock_page_hook(struct page *page);
 #endif