From owner-freebsd-stable@FreeBSD.ORG Fri Jul 6 22:02:18 2012 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 5FB64106566B for ; Fri, 6 Jul 2012 22:02:18 +0000 (UTC) (envelope-from vince@unsane.co.uk) Received: from unsane.co.uk (unsane-pt.tunnel.tserv5.lon1.ipv6.he.net [IPv6:2001:470:1f08:110::2]) by mx1.freebsd.org (Postfix) with ESMTP id C41858FC0A for ; Fri, 6 Jul 2012 22:02:17 +0000 (UTC) Received: from vincemacbook.unsane.co.uk (vincemacbook.unsane.co.uk [10.10.10.20]) (authenticated bits=0) by unsane.co.uk (8.14.5/8.14.5) with ESMTP id q66M2EI3068721 (version=TLSv1/SSLv3 cipher=DHE-RSA-CAMELLIA256-SHA bits=256 verify=NO) for ; Fri, 6 Jul 2012 23:02:16 +0100 (BST) (envelope-from vince@unsane.co.uk) Message-ID: <4FF76066.1000401@unsane.co.uk> Date: Fri, 06 Jul 2012 23:02:14 +0100 From: Vincent Hoffman User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: freebsd-stable@freebsd.org References: <4FF7055D.9000507@unsane.co.uk> In-Reply-To: X-Enigmail-Version: 1.4.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: nfs-bug when server for 9-Stable becomes client as well ? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 06 Jul 2012 22:02:18 -0000 On 06/07/2012 18:51, Arno J. Klaassen wrote: > Vincent Hoffman writes: > >> On 06/07/2012 14:19, Arno J. Klaassen wrote: >>> Hello, >>> >>> looks like I discouvered a probable bug in the nfs-code, very >>> easy to reproduce in my setup : >>> >>> >>> Machine-1 : Today's 9-stable, exporting /files (ufs) and /z2 (zfs) >>> >>> Machine-2 : 8-stable as of April the 10th exporting /raid1 >>> >>> On Machine-1 I mount /raid1 (rw,nfsv3,intr,tcp,rsize=32768,wsize=32768) >>> and start a script on this mount looping something like : >>> >>> dd if=/dev/random of=BIG bs=1048576 count=${SIZE} >>> cp -fp BIG BIG2 >>> cmp -x BIG BIG2 >>> >>> I let this run for 24 hours (from time to time stressing Machine-1 with >>> other scripts, including provoking heavy swapping), no problem at all. >>> >>> However, then I mount /z2 (rw,nfsv3,intr,tcp,rsize=32768,wsize=32768) >>> on Machine-2, and *immediately* the above loop on Machine-1 fails : >>> >>> Copying file ...cp: BIG: Permission denied >>> >>> No console messages this time, last time I got >>> >>> kernel: nfs_getpages: error 13 >>> kernel: vm_fault: pager read error, pid 87803 (cmp) >>> >>> on Machine-1. >>> >>> I repeated this scenario by replacing Machine-2 with a good old >>> 6-4-stable one, same outcome. >>> >>> Please tell me what I could do to nail this down a bit more. >> Its possible (although not definite) that you have hit the a mountd bug >> as documented in PRs >> >> kern/131342 >> kern/136865 > especially kern/131342 looks similar and quite old; funny I never hit > this before, I basically do the same tests since 'ages' on each new box. > Could be that faster network/cpu unreveals some race condition; I notice > as well that this server is the first (IIRC) who uses 3 different IRQs > for network interrupts (em(4) Intel(R) PRO/1000). Certainly possible and seems reasonable enough. > >> I've recently asked on -CURRENT about this and had a patch to try from >> Rick, I'm testing it now but it doesnt seem to fix it for me, just >> improve it alothough I'm trying to get enough runs to be a valid sample. >> (see >> http://docs.freebsd.org/cgi/getmsg.cgi?fetch=377627+0+archive/2012/freebsd-current/20120701.freebsd-current >> ) >> >> What I did for my production nas was edit mount.c so it didnt send a >> SIGHUP to mountd as suggested by rick, as it was easy to do and non >> intrusive. > hmm, this means I should patch each fbsd-client, no? May be easier to > patch mountd to ignore SIHGUP and use some non-standard signal to force > re-init? No just patch /sbin/mount on the nfs server so it doesnt send the SIGHUP to mountd. you can manually HUP mountd if needed. > > Arno > > >> Vince >> >>> Thanx in advance, >>> >>> Best, Arno