[Midnightbsd-cvs] src [9042] trunk/sys/geom/geom_vfs.c: close race between geom destruction on g_vfs_close when softc destroyed and g_vfs_orpha call that tries to access softc

[laffer1 at midnightbsd.org]

Revision: 9042
          http://svnweb.midnightbsd.org/src/?rev=9042
Author:   laffer1
Date:     2016-10-01 05:57:20 -0400 (Sat, 01 Oct 2016)
Log Message:
-----------
close race between geom destruction on g_vfs_close when softc destroyed and g_vfs_orpha call that tries to access softc

Modified Paths:
--------------
    trunk/sys/geom/geom_vfs.c

Modified: trunk/sys/geom/geom_vfs.c
===================================================================
--- trunk/sys/geom/geom_vfs.c	2016-10-01 09:56:36 UTC (rev 9041)
+++ trunk/sys/geom/geom_vfs.c	2016-10-01 09:57:20 UTC (rev 9042)
@@ -211,8 +211,10 @@
 	g_topology_assert();
 
 	gp = cp->geom;
+	g_trace(G_T_TOPOLOGY, "g_vfs_orphan(%p(%s))", cp, gp->name);
 	sc = gp->softc;
-	g_trace(G_T_TOPOLOGY, "g_vfs_orphan(%p(%s))", cp, gp->name);
+	if (sc == NULL)
+		return;
 	mtx_lock(&sc->sc_mtx);
 	sc->sc_orphaned = 1;
 	destroy = (sc->sc_active == 0);