Index: sys/fs/nullfs/null_vnops.c
===================================================================
--- sys/fs/nullfs/null_vnops.c
+++ sys/fs/nullfs/null_vnops.c
@@ -696,7 +696,7 @@
 		vdrop(lvp);
 	} else {
 		VI_UNLOCK(vp);
-		error = vop_stdlock(ap);
+		error = vop_stdlock_vnlock(ap);
 	}
 
 	return (error);
@@ -721,7 +721,7 @@
 		error = VOP_UNLOCK(lvp, 0);
 		vdrop(lvp);
 	} else {
-		error = vop_stdunlock(ap);
+		error = vop_stdunlock_vnlock(ap);
 	}
 
 	return (error);
@@ -927,7 +927,7 @@
 	.vop_getwritemount =	null_getwritemount,
 	.vop_inactive =		null_inactive,
 	.vop_need_inactive =	null_need_inactive,
-	.vop_islocked =		vop_stdislocked,
+	.vop_islocked =		vop_stdislocked_vnlock,
 	.vop_lock1 =		null_lock,
 	.vop_lookup =		null_lookup,
 	.vop_open =		null_open,
Index: sys/fs/unionfs/union_vnops.c
===================================================================
--- sys/fs/unionfs/union_vnops.c
+++ sys/fs/unionfs/union_vnops.c
@@ -1771,13 +1771,13 @@
 
 	unp = VTOUNIONFS(ap->a_vp);
 	if (unp == NULL)
-		return (vop_stdislocked(ap));
+		return (vop_stdislocked_vnlock(ap));
 
 	if (unp->un_uppervp != NULLVP)
 		return (VOP_ISLOCKED(unp->un_uppervp));
 	if (unp->un_lowervp != NULLVP)
 		return (VOP_ISLOCKED(unp->un_lowervp));
-	return (vop_stdislocked(ap));
+	return (vop_stdislocked_vnlock(ap));
 }
 
 static int
@@ -1946,7 +1946,7 @@
 				VOP_UNLOCK(lvp, LK_RELEASE);
 				vdrop(lvp);
 			}
-			return (vop_stdlock(ap));
+			return (vop_stdlock_vnlock(ap));
 		}
 		if (error != 0 && lvp != NULLVP) {
 			/* rollback */
@@ -1967,7 +1967,7 @@
 
 unionfs_lock_null_vnode:
 	ap->a_flags |= LK_INTERLOCK;
-	return (vop_stdlock(ap));
+	return (vop_stdlock_vnlock(ap));
 }
 
 static int
@@ -2013,7 +2013,7 @@
 	return error;
 
 unionfs_unlock_null_vnode:
-	return (vop_stdunlock(ap));
+	return (vop_stdunlock_vnlock(ap));
 }
 
 static int
Index: sys/kern/vfs_default.c
===================================================================
--- sys/kern/vfs_default.c
+++ sys/kern/vfs_default.c
@@ -512,8 +512,9 @@
 	struct vnode *vp = ap->a_vp;
 	struct mtx *ilk;
 
+	MPASS(vp->v_vnlock == &vp->v_lock);
 	ilk = VI_MTX(vp);
-	return (lockmgr_lock_fast_path(vp->v_vnlock, ap->a_flags,
+	return (lockmgr_lock_fast_path(&vp->v_lock, ap->a_flags,
 	    &ilk->lock_object, ap->a_file, ap->a_line));
 }
 
@@ -528,8 +529,9 @@
 	struct vnode *vp = ap->a_vp;
 	struct mtx *ilk;
 
+	MPASS(vp->v_vnlock == &vp->v_lock);
 	ilk = VI_MTX(vp);
-	return (lockmgr_unlock_fast_path(vp->v_vnlock, ap->a_flags,
+	return (lockmgr_unlock_fast_path(&vp->v_lock, ap->a_flags,
 	    &ilk->lock_object));
 }
 
@@ -541,6 +543,54 @@
 	} */ *ap;
 {
 
+	MPASS(ap->a_vp->v_vnlock == &ap->a_vp->v_lock);
+	return (lockstatus(&ap->a_vp->v_lock));
+}
+
+/*
+ * Variants of the aboe which read the v_vnlock pointer.
+ */
+int
+vop_stdlock_vnlock(ap)
+	struct vop_lock1_args /* {
+		struct vnode *a_vp;
+		int a_flags;
+		char *file;
+		int line;
+	} */ *ap;
+{
+	struct vnode *vp = ap->a_vp;
+	struct mtx *ilk;
+
+	ilk = VI_MTX(vp);
+	return (lockmgr_lock_fast_path(vp->v_vnlock, ap->a_flags,
+	    &ilk->lock_object, ap->a_file, ap->a_line));
+}
+
+/* See above. */
+int
+vop_stdunlock_vnlock(ap)
+	struct vop_unlock_args /* {
+		struct vnode *a_vp;
+		int a_flags;
+	} */ *ap;
+{
+	struct vnode *vp = ap->a_vp;
+	struct mtx *ilk;
+
+	ilk = VI_MTX(vp);
+	return (lockmgr_unlock_fast_path(vp->v_vnlock, ap->a_flags,
+	    &ilk->lock_object));
+}
+
+/* See above. */
+int
+vop_stdislocked_vnlock(ap)
+	struct vop_islocked_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+
 	return (lockstatus(ap->a_vp->v_vnlock));
 }
 
Index: sys/sys/vnode.h
===================================================================
--- sys/sys/vnode.h
+++ sys/sys/vnode.h
@@ -760,11 +760,14 @@
 int	vop_stdgetpages(struct vop_getpages_args *);
 int	vop_stdinactive(struct vop_inactive_args *);
 int	vop_stdneed_inactive(struct vop_need_inactive_args *);
-int	vop_stdislocked(struct vop_islocked_args *);
 int	vop_stdkqfilter(struct vop_kqfilter_args *);
+int	vop_stdislocked(struct vop_islocked_args *);
 int	vop_stdlock(struct vop_lock1_args *);
-int	vop_stdputpages(struct vop_putpages_args *);
 int	vop_stdunlock(struct vop_unlock_args *);
+int	vop_stdislocked_vnlock(struct vop_islocked_args *);
+int	vop_stdlock_vnlock(struct vop_lock1_args *);
+int	vop_stdunlock_vnlock(struct vop_unlock_args *);
+int	vop_stdputpages(struct vop_putpages_args *);
 int	vop_nopoll(struct vop_poll_args *);
 int	vop_stdaccess(struct vop_access_args *ap);
 int	vop_stdaccessx(struct vop_accessx_args *ap);
Index: sys/ufs/ffs/ffs_vnops.c
===================================================================
--- sys/ufs/ffs/ffs_vnops.c
+++ sys/ufs/ffs/ffs_vnops.c
@@ -134,7 +134,9 @@
 	.vop_fdatasync =	ffs_fdatasync,
 	.vop_getpages =		ffs_getpages,
 	.vop_getpages_async =	ffs_getpages_async,
+	.vop_islocked =		vop_stdislocked_vnlock,
 	.vop_lock1 =		ffs_lock,
+	.vop_unlock =		vop_stdunlock_vnlock,
 	.vop_read =		ffs_read,
 	.vop_reallocblks =	ffs_reallocblks,
 	.vop_write =		ffs_write,
@@ -145,7 +147,9 @@
 	.vop_default =		&ufs_fifoops,
 	.vop_fsync =		ffs_fsync,
 	.vop_fdatasync =	ffs_fdatasync,
+	.vop_islocked =		vop_stdislocked_vnlock,
 	.vop_lock1 =		ffs_lock,
+	.vop_unlock =		vop_stdunlock_vnlock,
 	.vop_vptofh =		ffs_vptofh,
 };
 
@@ -156,7 +160,9 @@
 	.vop_fdatasync =	ffs_fdatasync,
 	.vop_getpages =		ffs_getpages,
 	.vop_getpages_async =	ffs_getpages_async,
+	.vop_islocked =		vop_stdislocked_vnlock,
 	.vop_lock1 =		ffs_lock,
+	.vop_unlock =		vop_stdunlock_vnlock,
 	.vop_read =		ffs_read,
 	.vop_reallocblks =	ffs_reallocblks,
 	.vop_write =		ffs_write,
@@ -173,7 +179,9 @@
 	.vop_default =		&ufs_fifoops,
 	.vop_fsync =		ffs_fsync,
 	.vop_fdatasync =	ffs_fdatasync,
+	.vop_islocked =		vop_stdislocked_vnlock,
 	.vop_lock1 =		ffs_lock,
+	.vop_unlock =		vop_stdunlock_vnlock,
 	.vop_reallocblks =	ffs_reallocblks,
 	.vop_strategy =		ffsext_strategy,
 	.vop_closeextattr =	ffs_closeextattr,
Index: sys/ufs/ufs/ufs_vnops.c
===================================================================
--- sys/ufs/ufs/ufs_vnops.c
+++ sys/ufs/ufs/ufs_vnops.c
@@ -2738,6 +2738,9 @@
 	.vop_inactive =		ufs_inactive,
 	.vop_ioctl =		ufs_ioctl,
 	.vop_link =		ufs_link,
+	.vop_islocked =		vop_stdislocked_vnlock,
+	.vop_lock1 =		vop_stdlock_vnlock,
+	.vop_unlock =		vop_stdunlock_vnlock,
 	.vop_lookup =		vfs_cache_lookup,
 	.vop_markatime =	ufs_markatime,
 	.vop_mkdir =		ufs_mkdir,
@@ -2785,6 +2788,9 @@
 	.vop_read =		VOP_PANIC,
 	.vop_reclaim =		ufs_reclaim,
 	.vop_setattr =		ufs_setattr,
+	.vop_islocked =		vop_stdislocked_vnlock,
+	.vop_lock1 =		vop_stdlock_vnlock,
+	.vop_unlock =		vop_stdunlock_vnlock,
 #ifdef MAC
 	.vop_setlabel =		vop_stdsetlabel_ea,
 #endif