Index: sys/sys/systm.h
===================================================================
--- sys/sys/systm.h
+++ sys/sys/systm.h
@@ -111,12 +111,21 @@
 		kassert_panic msg;					\
 	}								\
 } while (0)
+#define	VNPASS(exp, vp)	do {						\
+	if (__predict_false(!(exp))) {					\
+		vn_printf(vp, "VNASSERT failed\n");			\
+		kassert_panic ("condition %s not met at %s:%d (%s)",	\
+		    #exp, __FILE__, __LINE__, __func__);		\
+	}								\
+} while (0)
 #else
 #define	KASSERT(exp,msg) do { \
 } while (0)
 
 #define	VNASSERT(exp, vp, msg) do { \
 } while (0)
+#define	VNPASS(exp, vp) do { \
+} while (0)
 #endif
 
 #ifndef CTASSERT	/* Allow lint to override */