Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-ie0-f177.google.com ([209.85.223.177]:57740 "EHLO mail-ie0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756228AbaIWPC2 convert rfc822-to-8bit (ORCPT ); Tue, 23 Sep 2014 11:02:28 -0400 Received: by mail-ie0-f177.google.com with SMTP id x19so9521169ier.22 for ; Tue, 23 Sep 2014 08:02:28 -0700 (PDT) Content-Type: text/plain; charset=windows-1252 Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.6\)) Subject: Re: WARNING at fs/nfs/write.c:743 nfs_inode_remove_request with -rc6 From: Weston Andros Adamson In-Reply-To: <5294BEB2-F20F-4E3E-BFB2-E41806A4F85A@primarydata.com> Date: Tue, 23 Sep 2014 11:02:26 -0400 Cc: Peng Tao , Trond Myklebust , linux-nfs list , "linux-kernel@vger.kernel.org" Message-Id: References: <20140923130352.GK26472@arm.com> <2A327753-3E60-46AC-8220-3FF0FF61F08F@primarydata.com> <20140923135938.GB28608@arm.com> <20140923145356.GD28608@arm.com> <5294BEB2-F20F-4E3E-BFB2-E41806A4F85A@primarydata.com> To: Will Deacon Sender: linux-nfs-owner@vger.kernel.org List-ID: On Sep 23, 2014, at 10:59 AM, Weston Andros Adamson wrote: > On Sep 23, 2014, at 10:53 AM, Will Deacon wrote: > >> On Tue, Sep 23, 2014 at 02:59:38PM +0100, Will Deacon wrote: >>> On Tue, Sep 23, 2014 at 02:33:06PM +0100, Weston Andros Adamson wrote: >>>> Any more info on how to reproduce this would be really great. Unfortunately I don?t >>>> have access to an arm64 system. >>> >>> I've not spotted a pattern other than using 64k pages, yet. If I manage to >>> get a reproducer, I'll let you know. >>> >>>> If it?s possible, could we get a packet trace around when this happens? This is pure >>>> speculation, but this might have something to do the resend path - a commit fails >>>> and all the requests on the commit list have to be resent. >>> >>> Sure, once I can reproduce it reliably, then I'll try to do that. >> >> Right, a bunch of DDing from /dev/zero over an ssh session triggers this >> very quickly. I've put a binary tcpdump here: >> >> http://www.willdeacon.ukfsn.org/bitbucket/oopsen/nfs/tcpdump.bin >> >> You may want to filter out the ssh packets. The only `interesting' thing to >> me is a retransmission about half way through, but I don't know what I'm >> looking for. >> >> The NFS server is 10.1.203.204 and the client is 10.1.203.24. > > Thanks! You are using NFSv2, so there are no commits - that rules out my hunch. Wait a second - the whole point of this extra reference (that the WARN_ON_ONCE is related to) is to handle the pass off to commit lists. Maybe I?m just doing the wrong thing here with NFSv2! More soon. -dros