diff --git a/sys/fs/tmpfs/tmpfs.h b/sys/fs/tmpfs/tmpfs.h
--- a/sys/fs/tmpfs/tmpfs.h
+++ b/sys/fs/tmpfs/tmpfs.h
@@ -516,7 +516,6 @@
  * Convenience macros to simplify some logical expressions.
  */
 #define IMPLIES(a, b) (!(a) || (b))
-#define IFF(a, b) (IMPLIES(a, b) && IMPLIES(b, a))
 
 /*
  * Checks that the directory entry pointed by 'de' matches the name 'name'
diff --git a/sys/fs/tmpfs/tmpfs_subr.c b/sys/fs/tmpfs/tmpfs_subr.c
--- a/sys/fs/tmpfs/tmpfs_subr.c
+++ b/sys/fs/tmpfs/tmpfs_subr.c
@@ -547,8 +547,8 @@
 	 * allocated, this must be the request to do it. */
 	MPASS(IMPLIES(tmp->tm_root == NULL, parent == NULL && type == VDIR));
 
-	MPASS(IFF(type == VLNK, target != NULL));
-	MPASS(IFF(type == VBLK || type == VCHR, rdev != VNOVAL));
+	MPASS((type == VLNK) ^ (target == NULL));
+	MPASS((type == VBLK || type == VCHR) ^ (rdev == VNOVAL));
 
 	if (tmp->tm_nodes_inuse >= tmp->tm_nodes_max)
 		return (ENOSPC);
@@ -1110,7 +1110,8 @@
 		*vpp = vp;
 
 #ifdef INVARIANTS
-		MPASS(*vpp != NULL && VOP_ISLOCKED(*vpp));
+		MPASS(*vpp != NULL);
+		ASSERT_VOP_LOCKED(*vpp, __func__);
 		TMPFS_NODE_LOCK(node);
 		MPASS(*vpp == node->tn_vnode);
 		TMPFS_NODE_UNLOCK(node);
diff --git a/sys/fs/tmpfs/tmpfs_vnops.c b/sys/fs/tmpfs/tmpfs_vnops.c
--- a/sys/fs/tmpfs/tmpfs_vnops.c
+++ b/sys/fs/tmpfs/tmpfs_vnops.c
@@ -222,7 +222,10 @@
 	 * If there were no errors, *vpp cannot be null and it must be
 	 * locked.
 	 */
-	MPASS(IFF(error == 0, *vpp != NULLVP && VOP_ISLOCKED(*vpp)));
+	if (error == 0) {
+		MPASS(*vpp != NULLVP);
+		ASSERT_VOP_LOCKED(*vpp, __func__);
+	}
 
 	return (error);
 }
@@ -545,7 +548,6 @@
 
 	int error;
 
-	MPASS(VOP_ISLOCKED(vp));
 	ASSERT_VOP_IN_SEQC(vp);
 
 	error = 0;
@@ -588,8 +590,6 @@
 	 */
 	tmpfs_update(vp);
 
-	MPASS(VOP_ISLOCKED(vp));
-
 	return (error);
 }
 
@@ -725,8 +725,6 @@
 {
 	struct vnode *vp = v->a_vp;
 
-	MPASS(VOP_ISLOCKED(vp));
-
 	tmpfs_check_mtime(vp);
 	tmpfs_update(vp);
 
@@ -745,9 +743,6 @@
 	struct tmpfs_node *dnode;
 	struct tmpfs_node *node;
 
-	MPASS(VOP_ISLOCKED(dvp));
-	MPASS(VOP_ISLOCKED(vp));
-
 	if (vp->v_type == VDIR) {
 		error = EISDIR;
 		goto out;
@@ -796,7 +791,6 @@
 	struct tmpfs_dirent *de;
 	struct tmpfs_node *node;
 
-	MPASS(VOP_ISLOCKED(dvp));
 	MPASS(dvp != vp); /* XXX When can this be false? */
 	node = VP_TO_TMPFS_NODE(vp);
 
@@ -987,9 +981,6 @@
 	int error;
 	bool want_seqc_end;
 
-	MPASS(VOP_ISLOCKED(tdvp));
-	MPASS(IMPLIES(tvp != NULL, VOP_ISLOCKED(tvp)));
-
 	want_seqc_end = false;
 
 	/*
@@ -1323,9 +1314,6 @@
 	struct tmpfs_node *dnode;
 	struct tmpfs_node *node;
 
-	MPASS(VOP_ISLOCKED(dvp));
-	MPASS(VOP_ISLOCKED(vp));
-
 	tmp = VFS_TO_TMPFS(dvp->v_mount);
 	dnode = VP_TO_TMPFS_DIR(dvp);
 	node = VP_TO_TMPFS_DIR(vp);