From owner-freebsd-current@FreeBSD.ORG Sun Apr 5 11:15:09 2009 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 12F07106564A for ; Sun, 5 Apr 2009 11:15:09 +0000 (UTC) (envelope-from M.S.Powell@salford.ac.uk) Received: from relay0.salford.ac.uk (relay0.salford.ac.uk [146.87.0.10]) by mx1.freebsd.org (Postfix) with SMTP id 7BD998FC0A for ; Sun, 5 Apr 2009 11:15:08 +0000 (UTC) (envelope-from M.S.Powell@salford.ac.uk) Received: (qmail 51944 invoked by uid 98); 5 Apr 2009 11:15:07 -0000 Received: from 146.87.255.121 by relay0.salford.ac.uk (envelope-from , uid 401) with qmail-scanner-2.01 (clamdscan: 0.94.2/9205. spamassassin: 3.2.4. Clear:RC:1(146.87.255.121):. Processed in 0.036635 secs); 05 Apr 2009 11:15:07 -0000 Received: from rust.salford.ac.uk (HELO rust.salford.ac.uk) (146.87.255.121) by relay0.salford.ac.uk (qpsmtpd/0.3x.614) with SMTP; Sun, 05 Apr 2009 12:15:06 +0100 Received: (qmail 30370 invoked by uid 1002); 5 Apr 2009 11:15:04 -0000 Received: from localhost (sendmail-bs@127.0.0.1) by localhost with SMTP; 5 Apr 2009 11:15:04 -0000 Date: Sun, 5 Apr 2009 12:15:04 +0100 (BST) From: "Mark Powell" To: Stefan Bethke In-Reply-To: <190B8595-BAF8-41F5-B63F-64604672BFD3@lassitu.de> Message-ID: <20090405120658.A24261@rust.salford.ac.uk> References: <20090404124909.C24261@rust.salford.ac.uk> <190B8595-BAF8-41F5-B63F-64604672BFD3@lassitu.de> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: freebsd-current@freebsd.org Subject: Re: panic: vput: negative ref cnt X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 05 Apr 2009 11:15:09 -0000 On Sun, 5 Apr 2009, Stefan Bethke wrote: Stefan, Thanks for the input. > Am 04.04.2009 um 13:55 schrieb Mark Powell: >> My script takes a zfs snapshot, mounts the snapshot, backs it up using >> star, then umounts the snapshot. The panic seems to occur on the umount. > > This is a different panic from the one I was getting, but appears to occur > under the same circumstances. > > I managed to avoid the panic by keeping the snapshot until the next run of my > backup script, and not unmounting anything. Yeah, I got around it by avoiding the unmount. My script dates from 7-STABLE days, where a zfs bug caused the automounted snapdir e.g. .zfs/snapshot/star_L0_2009-04-04-16:57, to be missing a '..' entry. That prevented star from detecting that I was performing a true full backup. Thus my script directly mounted the snapshot to get a proper fs with a '..' entry and unmounted it when finished. Now the included version of zfs in 8-CURRENT doesn't have that bug any longer. So I've reverted to backing up the automounted snapdir. Consequently as I don't perform a mount I don't have to unmount either, effectively working around the bug. > See > Do you know if a PR has been submitted for this one? Cheers. -- Mark Powell - UNIX System Administrator - The University of Salford Information & Learning Services, Clifford Whitworth Building, Salford University, Manchester, M5 4WT, UK. Tel: +44 161 295 6843 Fax: +44 161 295 5888 www.pgp.com for PGP key