From: =?UTF-8?B?VG9yYWxmIEbDtnJzdGVy?= Subject: Re: [uml-devel] Issues with a rather unusual configured NFS server Date: Fri, 30 Aug 2013 16:10:42 +0200 Message-ID: <5220A7E2.1070704@gmx.de> References: <52075E01.7030506@gmx.de> <20130812143640.GF4596@quack.suse.cz> <20130813215313.GH17781@fieldses.org> <20130827180655.GE14809@fieldses.org> <521E318C.7040401@gmx.de> <20130829133010.GA14773@fieldses.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: richard -rw- weinberger , Linux NFS mailing list , "J. Bruce Fields" , "user-mode-linux-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org" , Linux Kernel , Jan Kara , linux-ext4-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "J. Bruce Fields" Return-path: In-Reply-To: <20130829133010.GA14773-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org> Sender: linux-nfs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-ext4.vger.kernel.org On 08/29/2013 03:30 PM, J. Bruce Fields wrote: > On Thu, Aug 29, 2013 at 11:57:45AM +0200, richard -rw- weinberger wro= te: >> On Wed, Aug 28, 2013 at 7:21 PM, Toralf F=C3=B6rster wrote: >>> On 08/27/2013 08:06 PM, J. Bruce Fields wrote: >>>> On Tue, Aug 13, 2013 at 05:53:14PM -0400, bfields wrote: >>>>> On Mon, Aug 12, 2013 at 04:36:40PM +0200, Jan Kara wrote: >>>>>> On Sun 11-08-13 11:48:49, Toralf F=C3=B6rster wrote: >>>>>>> so that the server either crashes (if it is a user mode linux i= mage) or at least its reboot functionality got broken >>>>>>> - if the NFS server is hammered with scary NFS calls using a fu= zzy tool running at a remote NFS client under a non-privileged user id. >>>>>>> >>>>>>> It can re reproduced, if >>>>>>> - the NFS share is an EXT3 or EXT4 directory >>>>>>> - and it is created at file located at tempfs and mounted vi= a loop device >>>>>>> - and the NFS server is forced to umount the NFS share >>>>>>> - and the server forced to restart the NSF service afterward= s >>>>>>> - and trinity is used >>>>>>> >>>>>>> I could find a scenario for an automated bisect. 2 times it bro= ught this commit >>>>>>> commit 68a3396178e6688ad7367202cdf0af8ed03c8727 >>>>>>> Author: J. Bruce Fields >>>>>>> Date: Thu Mar 21 11:21:50 2013 -0400 >>>>>>> >>>>>>> nfsd4: shut down more of delegation earlier >>>>> >>>>> Thanks for the report. I think I see the problem--after this com= mit >>>>> nfs4_set_delegation() failures result in nfs4_put_delegation bein= g >>>>> called, but nfs4_put_delegation doesn't free the nfs4_file that h= as >>>>> already been set by alloc_init_deleg(). >>>>> >>>>> Let me think about how to fix that.... >>>> >>>> Sorry for the slow response--can you check whether this fixes the >>>> problem? >>>> >>> Yes. >>> >>> With the attached patch the problem can't be reproduced any longer = with >>> the prepared test case and current git kernels. >> >> BTW: Is nobody else fuzz testing NFS? >=20 > I don't know. Toralf's reports are the only ones I recall off the to= p > of my head, but I may have forgotten others. >=20 well, 7255e71 and 3c50ba8 I'd say. >> Or are these bugs just more likely to hit on UML? This definitely not. I observed at a real system EXT4 corruptions/ issues but reported them to the EXT4 mailing list. It just took me a longer time to figure out a reliable configuration with 2 UML machiens to automatic bisect it. > That's also possible. >=20 >> This is not the first NFS issue found by Toralf using UML and Trinit= y. >=20 > Yep. The testing is definitely appreciated. Thx - in the mean while although my UML bisect scripts are working fine and trinity is stable enough even in UML environments to be trust worth= =2E >=20 > --b. >=20 --=20 MfG/Sincerely Toralf F=C3=B6rster pgp finger print: 7B1A 07F4 EC82 0F90 D4C2 8936 872A E508 7DB6 9DA3 -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html