Return-Path: Received: from mx4.wp.pl ([212.77.101.11]:4661 "EHLO mx4.wp.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S943729AbcJaP0A (ORCPT ); Mon, 31 Oct 2016 11:26:00 -0400 Date: Mon, 31 Oct 2016 15:25:50 +0000 From: Jakub Kicinski To: Anna Schumaker Cc: Yotam Gigi , Andy Adamson , "linux-nfs@vger.kernel.org" , "netdev@vger.kernel.org" , Trond Myklebust , "Yotam Gigi" , mlxsw Subject: Re: nfs NULL-dereferencing in net-next Message-ID: <20161031152550.10acb7e0@jkicinski-Precision-T1700> In-Reply-To: References: <20161017201943.64529739@jkicinski-Precision-T1700> <817e43c5-d88d-e616-7074-5715de29d319@Netapp.com> <20161026190840.3d46dad8@jkicinski-Precision-T1700> <0ab5021c-84eb-cb9f-c7f5-4d856fdb0f4b@Netapp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-nfs-owner@vger.kernel.org List-ID: On Thu, 27 Oct 2016 06:50:22 +0000, Yotam Gigi wrote: > >-----Original Message----- > >From: Anna Schumaker [mailto:Anna.Schumaker@Netapp.com] > >Sent: Wednesday, October 26, 2016 9:17 PM > >To: Jakub Kicinski > >Cc: Yotam Gigi ; Andy Adamson ; > >linux-nfs@vger.kernel.org; netdev@vger.kernel.org; Trond Myklebust > >; Yotam Gigi ; mlxsw > > > >Subject: Re: nfs NULL-dereferencing in net-next > > > >On 10/26/2016 02:08 PM, Jakub Kicinski wrote: > >> On Wed, 26 Oct 2016 16:15:24 +0000, Yotam Gigi wrote: > >>>> -----Original Message----- > >>>> From: Anna Schumaker [mailto:Anna.Schumaker@Netapp.com] > >>>> Sent: Wednesday, October 26, 2016 5:40 PM > >>>> To: Yotam Gigi ; Jakub Kicinski ; > >Andy > >>>> Adamson ; Anna Schumaker > >>>> ; linux-nfs@vger.kernel.org > >>>> Cc: netdev@vger.kernel.org; Trond Myklebust > >; > >>>> Yotam Gigi ; mlxsw > >>>> Subject: Re: nfs NULL-dereferencing in net-next > >>>> > >>>> On 10/25/2016 01:19 PM, Yotam Gigi wrote: > >>>>> > >>>>>> -----Original Message----- > >>>>>> From: netdev-owner@vger.kernel.org [mailto:netdev- > >owner@vger.kernel.org] > >>>> On > >>>>>> Behalf Of Jakub Kicinski > >>>>>> Sent: Monday, October 17, 2016 10:20 PM > >>>>>> To: Andy Adamson ; Anna Schumaker > >>>>>> ; linux-nfs@vger.kernel.org > >>>>>> Cc: netdev@vger.kernel.org; Trond Myklebust > >>>> > >>>>>> Subject: nfs NULL-dereferencing in net-next > >>>>>> > >>>>>> Hi! > >>>>>> > >>>>>> I'm hitting this reliably on net-next, HEAD at 3f3177bb680f > >>>>>> ("fsl/fman: fix error return code in mac_probe()"). > >>>>> > >>>>> > >>>>> I see the same thing. It happens constantly on some of my machines, making > >>>> them > >>>>> completely unusable. > >>>>> > >>>>> I bisected it and got to the commit: > >>>>> > >>>>> commit 04ea1b3e6d8ed4978bb608c1748530af3de8c274 > >>>>> Author: Andy Adamson > >>>>> Date: Fri Sep 9 09:22:27 2016 -0400 > >>>>> > >>>>> NFS add xprt switch addrs test to match client > >>>>> > >>>>> Signed-off-by: Andy Adamson > >>>>> Signed-off-by: Anna Schumaker > >>>> > >>>> Thanks for reporting on this everyone! Does this patch help? > >>> > >>> Actually, I still see the same bug with the same trace. > > > >Well, it was worth a shot. I'll keep poking at it. > > > >> > >> I rebuild the latest net-next and I'm not seeing the trace any more... > >> I'm only seeing this (with or without your patch): > >> > >> [ 23.465877] NFS: set_pnfs_layoutdriver: cl_exchange_flags 0x0 > >> [ 23.473784] NFS: set_pnfs_layoutdriver: cl_exchange_flags 0x0 > >> [ 23.588890] NFS: set_pnfs_layoutdriver: cl_exchange_flags 0x0 > >> [ 23.596746] NFS: set_pnfs_layoutdriver: cl_exchange_flags 0x0 > >> [ 23.781574] NFS: set_pnfs_layoutdriver: cl_exchange_flags 0x0 > >> [ 23.789599] NFS: set_pnfs_layoutdriver: cl_exchange_flags 0x0 > > > >Interesting, I get that too when I try to use NFS v4.1. It's weird that the crash would > >stop happening like that, so maybe something is racy in this area. > > > >Thanks for testing, Yotam and Jakub! > >Anna > > I just found out that it happens on any of my machines, once I put two nfs entries in > my fstab. If I put only one, I don't see the problem. > > I hope it might be helpful :) Hi Anna, any updates on this one? The crash came back half an hour after I reported that it was gone... Over the weekend David Miller rebased net-next on top of 4.9.0-rc3 and the bug is still there :( FWIW I also have multiple nfs mounts on my setup, 2 in fstab and one in a startup script. Following Yotam I dropped one of the fstab entries and things seem to be working (even though I still have multiple mounts, the other one just comes a bit later).