--- linux/fs/ext/chrdev.c	2018/04/24 18:12:19	1.1.1.2
+++ linux/fs/ext/chrdev.c	2018/04/24 18:14:18	1.1.1.3
@@ -62,7 +62,7 @@ struct inode_operations ext_chrdev_inode
 	NULL,			/* rename */
 	NULL,			/* readlink */
 	NULL,			/* follow_link */
-	ext_bmap,		/* bmap */
-	ext_truncate		/* truncate */
+	NULL,			/* bmap */
+	NULL			/* truncate */
 };