diff --git a/fs/internal.h b/fs/internal.h
index b4dac4f..6d4ef20 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -66,3 +66,8 @@
  * fs_struct.c
  */
 extern void chroot_fs_refs(struct path *, struct path *);
+
+/*
+ * file_table.c
+ */
+extern void mark_files_ro(struct super_block *);