svn commit: r228204 - head/sys/geom

[Alexander Motin]

Author: mav
Date: Fri Dec  2 17:09:48 2011
New Revision: 228204
URL: http://svn.freebsd.org/changeset/base/228204

Log:
  Close race between geom destruction on g_vfs_close() when softc destroyed
  and g_vfs_orphan() call that tries to access softc, intruced at r227015.
  
  PR:		kern/162997

Modified:
  head/sys/geom/geom_vfs.c

Modified: head/sys/geom/geom_vfs.c
==============================================================================
--- head/sys/geom/geom_vfs.c	Fri Dec  2 15:47:05 2011	(r228203)
+++ head/sys/geom/geom_vfs.c	Fri Dec  2 17:09:48 2011	(r228204)
@@ -169,8 +169,10 @@ g_vfs_orphan(struct g_consumer *cp)
 	g_topology_assert();
 
 	gp = cp->geom;
-	sc = gp->softc;
 	g_trace(G_T_TOPOLOGY, "g_vfs_orphan(%p(%s))", cp, gp->name);
+	sc = gp->softc;
+	if (sc == NULL)
+		return;
 	mtx_lock(&sc->sc_mtx);
 	sc->sc_orphaned = 1;
 	destroy = (sc->sc_active == 0);