From owner-freebsd-fs@FreeBSD.ORG  Mon Sep  9 17:11:34 2013
Return-Path: <owner-freebsd-fs@FreeBSD.ORG>
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 BEBFC91F
 for <freebsd-fs@FreeBSD.org>; Mon,  9 Sep 2013 17:11:34 +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 163512609
 for <freebsd-fs@FreeBSD.org>; Mon,  9 Sep 2013 17:11:33 +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 UAA09541;
 Mon, 09 Sep 2013 20:11:24 +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 1VJ4zk-0005xM-I1; Mon, 09 Sep 2013 20:11:24 +0300
Message-ID: <522E0118.5020106@FreeBSD.org>
Date: Mon, 09 Sep 2013 20:10:48 +0300
From: Andriy Gapon <avg@FreeBSD.org>
User-Agent: Mozilla/5.0 (X11; FreeBSD amd64;
 rv:17.0) Gecko/20130810 Thunderbird/17.0.8
MIME-Version: 1.0
To: Andreas Longwitz <longwitz@incore.de>
Subject: Re: zfs panic during find(1) on zfs snapshot directory
References: <522DF5A9.4070103@incore.de>
In-Reply-To: <522DF5A9.4070103@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 <freebsd-fs.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-fs>,
 <mailto:freebsd-fs-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-fs>
List-Post: <mailto:freebsd-fs@freebsd.org>
List-Help: <mailto:freebsd-fs-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-fs>,
 <mailto:freebsd-fs-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 09 Sep 2013 17:11:34 -0000

on 09/09/2013 19:22 Andreas Longwitz said the following:
> I would like to know if this panic is a known issue and can give more
> information from the kerneldump.

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
-- 
Andriy Gapon