svn commit: r253856 - stable/8/sys/cddl/contrib/opensolaris/uts/common/fs/zfs

[Alexander Motin]

Author: mav
Date: Thu Aug  1 09:48:12 2013
New Revision: 253856
URL: http://svnweb.freebsd.org/changeset/base/253856

Log:
  MFC r253754:
  Partially close race between calls of orphan() method from GEOM and close()
  method from ZFS core, that reliably causes use-after-free panic if SSD vdev
  detached during inititial erase.

Modified:
  stable/8/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c
Directory Properties:
  stable/8/sys/   (props changed)
  stable/8/sys/cddl/   (props changed)
  stable/8/sys/cddl/contrib/opensolaris/   (props changed)

Modified: stable/8/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c
==============================================================================
--- stable/8/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c	Thu Aug  1 09:42:17 2013	(r253855)
+++ stable/8/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c	Thu Aug  1 09:48:12 2013	(r253856)
@@ -69,6 +69,8 @@ vdev_geom_orphan(struct g_consumer *cp)
 	g_topology_assert();
 
 	vd = cp->private;
+	if (vd == NULL)
+		return;
 
 	/*
 	 * Orphan callbacks occur from the GEOM event thread.
@@ -689,6 +691,7 @@ vdev_geom_close(vdev_t *vd)
 		return;
 	vd->vdev_tsd = NULL;
 	vd->vdev_delayed_close = B_FALSE;
+	cp->private = NULL;	/* XXX locking */
 	g_post_event(vdev_geom_detach, cp, M_WAITOK, NULL);
 }