svn commit: r240822 - head/sys/geom

[Pawel Jakub Dawidek]

Author: pjd
Date: Sat Sep 22 12:41:49 2012
New Revision: 240822
URL: http://svn.freebsd.org/changeset/base/240822

Log:
  Use the topology lock to protect list of providers while withering them.
  It is possible that provider is destroyed while we are iterating over the
  list.
  
  Reported by:	Brian Parkison <parkison at panzura.com>
  Discussed with:	phk
  MFC after:	1 week

Modified:
  head/sys/geom/geom_disk.c

Modified: head/sys/geom/geom_disk.c
==============================================================================
--- head/sys/geom/geom_disk.c	Sat Sep 22 12:40:52 2012	(r240821)
+++ head/sys/geom/geom_disk.c	Sat Sep 22 12:41:49 2012	(r240822)
@@ -635,10 +635,13 @@ disk_gone(struct disk *dp)
 	struct g_geom *gp;
 	struct g_provider *pp;
 
+	g_topology_lock();
 	gp = dp->d_geom;
-	if (gp != NULL)
+	if (gp != NULL) {
 		LIST_FOREACH(pp, &gp->provider, provider)
 			g_wither_provider(pp, ENXIO);
+	}
+	g_topology_unlock();
 }
 
 void