From owner-freebsd-fs@FreeBSD.ORG Wed Mar 23 02:26:17 2011 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 92BEE1065672 for ; Wed, 23 Mar 2011 02:26:17 +0000 (UTC) (envelope-from lstewart@freebsd.org) Received: from lauren.room52.net (lauren.room52.net [210.50.193.198]) by mx1.freebsd.org (Postfix) with ESMTP id 59AD58FC1E for ; Wed, 23 Mar 2011 02:26:17 +0000 (UTC) Received: from lawrence1.loshell.room52.net (ppp59-167-184-191.static.internode.on.net [59.167.184.191]) by lauren.room52.net (Postfix) with ESMTPSA id 39ABB7E8D6 for ; Wed, 23 Mar 2011 13:26:15 +1100 (EST) Message-ID: <4D895A46.8030409@freebsd.org> Date: Wed, 23 Mar 2011 13:26:14 +1100 From: Lawrence Stewart User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-AU; rv:1.9.2.15) Gecko/20110308 Lightning/1.0b2 Thunderbird/3.1.9 MIME-Version: 1.0 To: freebsd-fs@freebsd.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=0.0 required=5.0 tests=UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on lauren.room52.net Subject: Deterministic unionfs panic triggered by kern_renameat() on 8.2-STABLE X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 23 Mar 2011 02:26:17 -0000 Hi all, I'm playing around with the changes to the ISO building infrastructure which Nathan Whitehorn has most recently been tweaking. I've built an ISO which runs as its first rc.d script the set of commands to create a unionfs over the top of the read only /etc. This is obviously desirable as it allows anything which attempts to write to /etc (e.g. hostid, sshd, dhclinet) to work transparently. Everything works great - system rc.d startup works, I can create files in /etc, edit existing files using ee, run dhclient without any command line switches etc. However, when I use vim to edit a file, it obviously uses a different syscall (kern_renameat) to any of the other programs I've tested, which triggers a deterministic panic. A screenshot of the panic from virtualbox and a basic reproduction recipe are available at [1]. Any thoughts on how to fix the locking? Cheers, Lawrence [1] http://people.freebsd.org/~lstewart/misc/unionfs_debug/