From owner-cvs-src@FreeBSD.ORG  Sat Jun 14 17:27:32 2003
Return-Path: <owner-cvs-src@FreeBSD.ORG>
Delivered-To: cvs-src@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP
	id 676CF37B401; Sat, 14 Jun 2003 17:27:32 -0700 (PDT)
Received: from HAL9000.homeunix.com (ip114.bella-vista.sfo.interquest.net
	[66.199.86.114])	by mx1.FreeBSD.org (Postfix) with ESMTP
	id E2A8C43FA3; Sat, 14 Jun 2003 17:27:30 -0700 (PDT)
	(envelope-from das@freebsd.org)
Received: from HAL9000.homeunix.com (localhost [127.0.0.1])
	by HAL9000.homeunix.com (8.12.9/8.12.9) with ESMTP id h5F0RSlB000828;
	Sat, 14 Jun 2003 17:27:29 -0700 (PDT)
	(envelope-from das@freebsd.org)
Received: (from das@localhost)
	by HAL9000.homeunix.com (8.12.9/8.12.9/Submit) id h5F0RRFA000827;
	Sat, 14 Jun 2003 17:27:27 -0700 (PDT)
	(envelope-from das@freebsd.org)
Date: Sat, 14 Jun 2003 17:27:27 -0700
From: David Schultz <das@freebsd.org>
To: src-committers@freebsd.org, cvs-src@freebsd.org,
	cvs-all@freebsd.org
Message-ID: <20030615002727.GB714@HAL9000.homeunix.com>
Mail-Followup-To: src-committers@freebsd.org, cvs-src@freebsd.org,
	cvs-all@freebsd.org
References: <200306142356.h5ENuRLO044296@repoman.freebsd.org>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <200306142356.h5ENuRLO044296@repoman.freebsd.org>
Subject: Re: cvs commit: src/sys/fs/unionfs union_vnops.c
X-BeenThere: cvs-src@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: CVS commit messages for the src tree <cvs-src.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/cvs-src>,
	<mailto:cvs-src-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/cvs-src>
List-Post: <mailto:cvs-src@freebsd.org>
List-Help: <mailto:cvs-src-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/cvs-src>,
	<mailto:cvs-src-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sun, 15 Jun 2003 00:27:32 -0000

On Sat, Jun 14, 2003, David Schultz wrote:
> das         2003/06/14 16:56:27 PDT
> 
>   FreeBSD src repository
> 
>   Modified files:
>     sys/fs/unionfs       union_vnops.c 
>   Log:
>   If someone tries to mount a union filesystem with another unionfs as
>   the upper layer, fail gracefully instead of panicing.

By the way, to clarify, VOP_WHITEOUT with the LOOKUP flag is used
by unionfs itself to detect whether the top layer you're trying to
mount over supports whiteout entries.  In this case, cnp->cn_thread
is NULL, so this commit fixes a null pointer dereference in the case
where one unionfs asks another whether it supports whiteout entries.