Am 01.09.2013 18:09, schrieb Toralf Förster: > On 08/30/2013 04:36 PM, Richard Weinberger wrote: >> Am 30.08.2013 16:10, schrieb Toralf Förster: >>> On 08/29/2013 03:30 PM, J. Bruce Fields wrote: >>>> On Thu, Aug 29, 2013 at 11:57:45AM +0200, richard -rw- weinberger wrote: >>>>> On Wed, Aug 28, 2013 at 7:21 PM, Toralf Förster 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 Förster wrote: >>>>>>>>>> so that the server either crashes (if it is a user mode linux image) or at least its reboot functionality got broken >>>>>>>>>> - if the NFS server is hammered with scary NFS calls using a fuzzy 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 via loop device >>>>>>>>>> - and the NFS server is forced to umount the NFS share >>>>>>>>>> - and the server forced to restart the NSF service afterwards >>>>>>>>>> - and trinity is used >>>>>>>>>> >>>>>>>>>> I could find a scenario for an automated bisect. 2 times it brought 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 commit >>>>>>>> nfs4_set_delegation() failures result in nfs4_put_delegation being >>>>>>>> called, but nfs4_put_delegation doesn't free the nfs4_file that has >>>>>>>> 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? >>>> >>>> I don't know. Toralf's reports are the only ones I recall off the top >>>> of my head, but I may have forgotten others. >>>> >>> >>> 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. >>>> >>>>> This is not the first NFS issue found by Toralf using UML and Trinity. >>>> >>>> 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. >> >> That's good to know. >> Thanks you and trinity we got rid of some nasty UML bugs. > > yeah, but there's (among others) one of them still in the wild: > If I start an UML and resize the terminal (KDE Konsole) during the boot > phase then it just crashes sometimes. Does the attached patch fix the problem? Thanks, //richard