lkml.org 
[lkml]   [2018]   [Apr]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: WARNING in up_write
On Wed, Apr 04, 2018 at 12:35:04PM -0700, Matthew Wilcox wrote:
> On Wed, Apr 04, 2018 at 09:24:05PM +0200, Dmitry Vyukov wrote:
> > On Tue, Apr 3, 2018 at 4:01 AM, syzbot
> > <syzbot+dc5ab2babdf22ca091af@syzkaller.appspotmail.com> wrote:
> > > DEBUG_LOCKS_WARN_ON(sem->owner != get_current())
> > > WARNING: CPU: 1 PID: 4441 at kernel/locking/rwsem.c:133 up_write+0x1cc/0x210
> > > kernel/locking/rwsem.c:133
> > > Kernel panic - not syncing: panic_on_warn set ...
>
> Message-Id: <1522852646-2196-1-git-send-email-longman@redhat.com>
>

We were way ahead of syzbot in this case. :-)

I reported the problem Tuesday morning:

https://lkml.org/lkml/2018/4/4/814

And within a few hours Waiman had proposed a fix:

https://patchwork.kernel.org/patch/10322639/

Note also that it's not ext4 specific. It can be trivially reproduced using any one of:

kvm-xfstests -c ext4 generic/068
kvm-xfstests -c btrfs generic/068
kvm-xfstests -c xfs generic/068

(Basically, any file system that supports freeze/thaw.)

Cheers,

- Ted

\
 
 \ /
  Last update: 2018-04-05 05:22    [W:0.084 / U:8.532 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site