Index: sys/kern/vfs_vnops.c
===================================================================
--- sys/kern/vfs_vnops.c
+++ sys/kern/vfs_vnops.c
@@ -2447,6 +2447,8 @@
 	off_t noff;
 	int error;
 
+	KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA,
+	    ("%s: Wrong command %lu", __func__, cmd));
 	ASSERT_VOP_LOCKED(vp, "vn_bmap_seekhole_locked");
 
 	if (vp->v_type != VREG) {
@@ -2494,7 +2496,7 @@
 	int error;
 
 	KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA,
-	    ("Wrong command %lu", cmd));
+	    ("%s: Wrong command %lu", __func__, cmd));
 
 	if (vn_lock(vp, LK_SHARED) != 0)
 		return (EBADF);