From owner-freebsd-fs@FreeBSD.ORG Sun Sep 15 21:09:47 2013 Return-Path: Delivered-To: freebsd-fs@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTP id 472C4714 for ; Sun, 15 Sep 2013 21:09:47 +0000 (UTC) (envelope-from avg@FreeBSD.org) Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id 96A6925E5 for ; Sun, 15 Sep 2013 21:09:46 +0000 (UTC) Received: from porto.starpoint.kiev.ua (porto-e.starpoint.kiev.ua [212.40.38.100]) by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id AAA10378; Mon, 16 Sep 2013 00:09:41 +0300 (EEST) (envelope-from avg@FreeBSD.org) Received: from localhost ([127.0.0.1]) by porto.starpoint.kiev.ua with esmtp (Exim 4.34 (FreeBSD)) id 1VLJZd-0009wV-LO; Mon, 16 Sep 2013 00:09:41 +0300 Message-ID: <523621DD.7050600@FreeBSD.org> Date: Mon, 16 Sep 2013 00:08:45 +0300 From: Andriy Gapon User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:17.0) Gecko/20130810 Thunderbird/17.0.8 MIME-Version: 1.0 To: Andreas Longwitz Subject: Re: zfs panic during find(1) on zfs snapshot directory References: <522DF5A9.4070103@incore.de> <522E0118.5020106@FreeBSD.org> <522F25AE.1080309@incore.de> In-Reply-To: <522F25AE.1080309@incore.de> X-Enigmail-Version: 1.5.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: freebsd-fs@FreeBSD.org X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 15 Sep 2013 21:09:47 -0000 on 10/09/2013 16:59 Andreas Longwitz said the following: > Thanks for quick answer ! > >> My personal recommendation is to keep .zfs directory hidden and/or perform only >> basic operations on entries under it while ensuring that there is only one >> process at a time that peeks there. >> >> The gfs stuff that handles .zfs operations is really very broken on FreeBSD[*]. >> If you are interested, I have a patch that should some of the mess, but not all. >> >> [*] To see what I mean run several of the following shell loops in parallel: >> while true; do ls -l /pool/fs/.zfs/ >/dev/null; done > > Ok, I was not aware of the problematic caused by visible snapdir > property. I think your recommendation to use the default snapdir > property hidden is fine for me and the panic I have described will not > happen again. > > On the other side a panic should not happen when a user configures > something else than the default. Therefore I am interested in helping to > test the broken gfs stuff on some of my test servers, so your offered > patch is welcome. Please try this patch: http://people.freebsd.org/~avg/zfs-gfs-8.diff Thank you! > I run zfs on production for a half year now, and I like to note that > this panic was the first problem on all of my (eight) production servers > running zfs. The only open zfs problem I have is described in kern/180060. > I will try to look into this issue. -- Andriy Gapon