svn commit: r323183 - head/sys/kern

[Edward Tomasz Napierala]

Author: trasz
Date: Tue Sep  5 14:32:56 2017
New Revision: 323183
URL: https://svnweb.freebsd.org/changeset/base/323183

Log:
  Make root_mount_rel(9) ignore NULL arguments, like it used to before r313351.
  It would be better to fix API consumers to not pass NULL there - most of them,
  such as gmirror, already contain the neccessary checks - but this is easier
  and much less error-prone.
  
  One known user-visible result is that it fixes panic on a failed "graid label".
  
  PR:		221846
  MFC after:	2 weeks
  Sponsored by:	DARPA, AFRL

Modified:
  head/sys/kern/vfs_mountroot.c

Modified: head/sys/kern/vfs_mountroot.c
==============================================================================
--- head/sys/kern/vfs_mountroot.c	Tue Sep  5 13:55:14 2017	(r323182)
+++ head/sys/kern/vfs_mountroot.c	Tue Sep  5 14:32:56 2017	(r323183)
@@ -183,7 +183,8 @@ void
 root_mount_rel(struct root_hold_token *h)
 {
 
-	KASSERT(h != NULL, ("%s: NULL token", __func__));
+	if (h == NULL)
+		return;
 
 	mtx_lock(&root_holds_mtx);
 	LIST_REMOVE(h, list);