Index: sys/geom/geom_disk.c
===================================================================
--- sys/geom/geom_disk.c	(wersja 240879)
+++ sys/geom/geom_disk.c	(kopia robocza)
@@ -635,13 +635,15 @@
 	struct g_geom *gp;
 	struct g_provider *pp;
 
-	g_topology_lock();
 	gp = dp->d_geom;
 	if (gp != NULL) {
-		LIST_FOREACH(pp, &gp->provider, provider)
+		pp = LIST_FIRST(&gp->provider);
+		if (pp != NULL) {
+			KASSERT(LIST_NEXT(pp, provider) == NULL,
+			    ("geom %p has more than one provider", gp));
 			g_wither_provider(pp, ENXIO);
+		}
 	}
-	g_topology_unlock();
 }
 
 void