Return-Path: Received: from mail-yw0-f46.google.com ([209.85.213.46]:34478 "EHLO mail-yw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757921Ab1FVWke convert rfc822-to-8bit (ORCPT ); Wed, 22 Jun 2011 18:40:34 -0400 In-Reply-To: <1308779507.25875.7.camel@lade.trondhjem.org> References: <1308767449.14997.10.camel@lade.trondhjem.org> <1308769054.14997.18.camel@lade.trondhjem.org> <1308779507.25875.7.camel@lade.trondhjem.org> Date: Wed, 22 Jun 2011 15:40:32 -0700 Message-ID: Subject: Re: Issue with Race Condition on NFS4 with KRB From: Joshua Scoggins To: Trond Myklebust Cc: linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 The patch isn't applying to the 2.6.39 kernel sources. -Josh On Wed, Jun 22, 2011 at 2:51 PM, Trond Myklebust wrote: > On Wed, 2011-06-22 at 12:18 -0700, Joshua Scoggins wrote: >> According to the it guys they are running solaris 10 as the server platform. > > Ok. That should not be subject to the race I was thinking of... > >> On Wed, Jun 22, 2011 at 11:57 AM, Trond Myklebust >> wrote: >> > On Wed, 2011-06-22 at 11:37 -0700, Joshua Scoggins wrote: >> >> Here are our mount options from auto.master >> >> >> >> /user -fstype=nfs4,sec=krb5p,noresvport,noatime >> >> /group -fstype=nfs4,sec=krb5p,noresvport,noatime >> >> >> >> As for the server, we don't control it. It's actually run by the >> >> campus wide it department we are just lab support for CS. I can >> >> potentially get the server information but I need to know what you want >> >> specifically as they're pretty paranoid about giving out information about >> >> their servers. >> > >> > I would just want to know _what_ server platform you are running >> > against. I know of at least one server bug that might explain what you >> > are seeing, and I'd like to eliminate that as a possibility. >> > >> > Trond >> > >> >> Joshua Scoggins >> >> >> >> On Wed, Jun 22, 2011 at 11:30 AM, Trond Myklebust >> >> wrote: >> >> > On Wed, 2011-06-22 at 11:21 -0700, Joshua Scoggins wrote: >> >> >> Hello, >> >> >> >> >> >> We are trying to update our linux images in our CS lab and have it a >> >> >> bit of an issue. We are >> >> >> using nfs to load user home folder. While testing the new image we >> >> >> found that the nfs4 module will >> >> >> ?crash when using firefox 3.6.17 for an extended period of time. Some >> >> >> research via google yielded that >> >> >> it's a potential race condition specific to nfs with krb auth with >> >> >> newer kernels. Our old image doesn't have >> >> >> this issue and it seems that its due to it running a far older kernel version. >> >> >> >> >> >> We have two images and both are having this problem. One is running >> >> >> 2.6.39 and the other is 2.6.38. >> >> >> Here is what dmesg spit out from the machine running 2.6.39 on one occasion: >> >> >> >> >> >> [ ?678.632061] ------------[ cut here ]------------ >> >> >> [ ?678.632068] WARNING: at net/sunrpc/clnt.c:1567 call_decode+0xb2/0x69c() >> >> >> [ ?678.632070] Hardware name: OptiPlex 755 >> >> >> [ ?678.632072] Modules linked in: nvidia(P) scsi_wait_scan >> >> >> [ ?678.632078] Pid: 3882, comm: kworker/0:2 Tainted: P >> >> >> 2.6.39-gentoo-r1 #1 >> >> >> [ ?678.632080] Call Trace: >> >> >> [ ?678.632086] ?[] warn_slowpath_common+0x80/0x98 >> >> >> [ ?678.632091] ?[] ? nfs4_xdr_dec_readdir+0xba/0xba >> >> >> [ ?678.632094] ?[] warn_slowpath_null+0x15/0x17 >> >> >> [ ?678.632097] ?[] call_decode+0xb2/0x69c >> >> >> [ ?678.632101] ?[] __rpc_execute+0x78/0x24b >> >> >> [ ?678.632104] ?[] ? rpc_execute+0x41/0x41 >> >> >> [ ?678.632107] ?[] rpc_async_schedule+0x10/0x12 >> >> >> [ ?678.632111] ?[] process_one_work+0x1d9/0x2e7 >> >> >> [ ?678.632114] ?[] worker_thread+0x133/0x24f >> >> >> [ ?678.632118] ?[] ? manage_workers+0x18d/0x18d >> >> >> [ ?678.632121] ?[] kthread+0x7d/0x85 >> >> >> [ ?678.632125] ?[] kernel_thread_helper+0x4/0x10 >> >> >> [ ?678.632128] ?[] ? kthread_worker_fn+0x13a/0x13a >> >> >> [ ?678.632131] ?[] ? gs_change+0xb/0xb >> >> >> [ ?678.632133] ---[ end trace 6bfae002a63e020e ]--- > > Looking at the code, there is only one way I can see for that warning to > occur, and that is if we put the request back on the 'xprt->recv' list > after it has already received a reply from the server. > > Can you reproduce the problem with the attached patch? > > Trond > > -- > Trond Myklebust > Linux NFS client maintainer > > NetApp > Trond.Myklebust@netapp.com > www.netapp.com > >