--- src/sys/sys/xio.h	2007/06/29 00:18:03	1.8
+++ src/sys/sys/xio.h	2007/06/29 05:09:14	1.9
@@ -84,6 +84,7 @@ typedef struct xio *xio_t;
 
 #define XIOF_READ	0x0001
 #define XIOF_WRITE	0x0002
+#define XIOF_VMLINEAR	0x0004	/* must be VM object linear */
 
 #endif