--- kernel/bsd/sys/buf.h	2018/04/24 18:26:01	1.1.1.1
+++ kernel/bsd/sys/buf.h	2018/04/24 18:28:49	1.1.1.2
@@ -105,7 +105,8 @@ struct buf {
 	int	b_validoff;		/* Offset in buffer of valid region. */
 	int	b_validend;		/* Offset of end of valid region. */
 	void 	*b_drvdata;		/* driver specific data */
-	long    b_reserved[4];	/* Reserved for future HFS use */
+	int     b_timestamp; 	/* timestamp for queuing operation */
+	long    b_reserved[3];	/* Reserved for future HFS use */
 };
 
 /*