Index: head/sys/geom/geom_dev.c
===================================================================
--- head/sys/geom/geom_dev.c	(revision 221202)
+++ head/sys/geom/geom_dev.c	(working copy)
@@ -80,6 +80,11 @@ static struct g_class g_dev_class	= {
 	.orphan = g_dev_orphan,
 };
 
+struct new_alias_args {
+	struct g_provider *pp;
+	char name[SPECNAMELEN];
+};
+
 void
 g_dev_print(void)
 {
@@ -107,7 +112,67 @@ g_dev_getprovider(struct cdev *dev)
 	return (cp->provider);
 }
 
+static void
+g_dev_new_alias(void *arg, int flag)
+{
+	struct new_alias_args *args;
+	struct g_consumer *cp;
+	struct g_geom *gp;
+	struct cdev *dev, *adev;
+	int error;
 
+	g_topology_assert();
+	args = (struct new_alias_args *)arg;
+	g_trace(G_T_TOPOLOGY, "g_dev_new_alias(%s, %s)", args->pp->name,
+	    args->name);
+
+	LIST_FOREACH(gp, &g_dev_class.geom, geom) {
+		cp = LIST_FIRST(&gp->consumer);
+		if (cp->provider == pp)
+			break;
+	}
+	if (gp == NULL) {
+		printf("%s: geom not found for provider %p\n",
+		    __func__, pp);
+		goto done;
+	}
+	dev = gp->softc;
+	error = make_dev_alias_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK, &adev,
+	    dev, args->name);
+	if (error != 0) {
+		printf("%s: make_dev_alias_p failed (name=%s, error=%d)\n",
+		    __func__, args->name, error);
+		goto done;
+	}
+	adev->si_iosize_max = MAXPHYS;
+	adev->si_drv1 = gp;
+	adev->si_drv2 = cp;
+	if (cp->provider->flags & G_PF_CANDELETE)
+		adev->si_flags |= SI_CANDELETE;
+done:
+	g_free(args);
+}
+
+void
+g_dev_make_alias(struct g_provider *pp, const char *fmt, ...)
+{
+	struct new_alias_args *args;
+	struct sbuf *sb;
+	va_list ap;
+
+	g_topology_assert();
+	sb = sbuf_new_auto();
+	va_start(ap, fmt);
+	sbuf_vprintf(sb, fmt, ap);
+	va_end(ap);
+	sbuf_finish(sb);
+
+	args = g_malloc(sizeof(*args), M_WAITOK | M_ZERO);
+	strlcpy(args->name, sbuf_data(sb), SPECNAMELEN);
+	args->pp = pp;
+	g_post_event(g_dev_new_alias, args, M_WAITOK, NULL);
+}
+
 static struct g_geom *
 g_dev_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
 {
Index: head/sys/geom/geom.h
===================================================================
--- head/sys/geom/geom.h	(revision 221202)
+++ head/sys/geom/geom.h	(working copy)
@@ -218,6 +218,7 @@ struct g_classifier_hook {
 struct cdev;
 void g_dev_print(void);
 struct g_provider *g_dev_getprovider(struct cdev *dev);
+void g_dev_make_alias(struct g_provider *pp, const char *fmt, ...);
 
 /* geom_dump.c */
 void g_trace(int level, const char *, ...);