svn commit: r229428 - head/sys/fs/nullfs

[Konstantin Belousov]

Author: kib
Date: Tue Jan  3 21:03:20 2012
New Revision: 229428
URL: http://svn.freebsd.org/changeset/base/229428

Log:
  Document the state of the lowervp vnode for null_nodeget().
  
  Tested by:	pho
  MFC after:	1 week

Modified:
  head/sys/fs/nullfs/null_subr.c

Modified: head/sys/fs/nullfs/null_subr.c
==============================================================================
--- head/sys/fs/nullfs/null_subr.c	Tue Jan  3 20:53:58 2012	(r229427)
+++ head/sys/fs/nullfs/null_subr.c	Tue Jan  3 21:03:20 2012	(r229428)
@@ -198,6 +198,9 @@ null_nodeget(mp, lowervp, vpp)
 	struct vnode *vp;
 	int error;
 
+	ASSERT_VOP_LOCKED(lowervp, "lowervp");
+	KASSERT(lowervp->v_usecount >= 1, ("Unreferenced vnode %p\n", vp));
+
 	/* Lookup the hash firstly */
 	*vpp = null_hashget(mp, lowervp);
 	if (*vpp != NULL) {