svn commit: r222274 - stable/8/sys/kern

[Konstantin Belousov]

Author: kib
Date: Wed May 25 03:25:14 2011
New Revision: 222274
URL: http://svn.freebsd.org/changeset/base/222274

Log:
  MFC r222086:
  The protection against the race with dev_rel(), introduced in r163328,
  should be extended to cover destroy_devl() calls for the children of the
  destroyed dev.

Modified:
  stable/8/sys/kern/kern_conf.c
Directory Properties:
  stable/8/sys/   (props changed)
  stable/8/sys/amd64/include/xen/   (props changed)
  stable/8/sys/cddl/contrib/opensolaris/   (props changed)
  stable/8/sys/contrib/dev/acpica/   (props changed)
  stable/8/sys/contrib/pf/   (props changed)

Modified: stable/8/sys/kern/kern_conf.c
==============================================================================
--- stable/8/sys/kern/kern_conf.c	Wed May 25 01:04:12 2011	(r222273)
+++ stable/8/sys/kern/kern_conf.c	Wed May 25 03:25:14 2011	(r222274)
@@ -885,6 +885,8 @@ destroy_devl(struct cdev *dev)
 	/* Remove name marking */
 	dev->si_flags &= ~SI_NAMED;
 
+	dev->si_refcount++;	/* Avoid race with dev_rel() */
+
 	/* If we are a child, remove us from the parents list */
 	if (dev->si_flags & SI_CHILD) {
 		LIST_REMOVE(dev, si_siblings);
@@ -901,7 +903,6 @@ destroy_devl(struct cdev *dev)
 		dev->si_flags &= ~SI_CLONELIST;
 	}
 
-	dev->si_refcount++;	/* Avoid race with dev_rel() */
 	csw = dev->si_devsw;
 	dev->si_devsw = NULL;	/* already NULL for SI_ALIAS */
 	while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) {