Re: 2.6.18 ext3 panic.

Jan Kara
2006-10-10T13:16:25Z

> On Mon, 2006-10-09 14:46:30 -0500, Eric Sandeen <sandeen@sandeen.net> wrote:
> > Andrew Morton wrote:
> > > On Tue, 03 Oct 2006 00:43:01 -0500
> > > Eric Sandeen <sandeen@sandeen.net> wrote:
> > > > Dave Jones wrote:
> > > > > So I managed to reproduce it with an 'fsx foo' and a
> > > > > 'fsstress -d . -r -n 100000 -p 20 -r'. This time I grabbed it from
> > > > > a vanilla 2.6.18 with none of the Fedora patches..
> > > > >
> > > > > I'll give 2.6.18-git a try next.
> > > > >
> > > > > ----------- [cut here ] --------- [please bite here ] ---------
> > > > > Kernel BUG at fs/buffer.c:2791
> > > > I had thought/hoped that this was fixed by Jan's patch at
> > > > http://lkml.org/lkml/2006/9/7/236 from the thread started at
> > > > http://lkml.org/lkml/2006/9/1/149, but it seems maybe not. Dave hit this bug
> > > > first by going through that new codepath....
> > >
> > > Yes, Jan's patch is supposed to fix that !buffer_mapped() assertion. iirc,
> > > Badari was hitting that BUG and was able to confirm that Jan's patch
> > > (3998b9301d3d55be8373add22b6bc5e11c1d9b71 in post-2.6.18 mainline) fixed
> > > it.
> >
> > Looking at some BH traces*, it appears that what Dave hit is a truncate
> > racing with a sync...
> >
> > truncate ...
> > ext3_invalidate_page
> > journal_invalidatepage
> > journal_unmap buffer
> >
> > going off at the same time as
> >
> > sync ...
> > journal_dirty_data
> > sync_dirty_buffer
> > submit_bh <-- finds unmapped buffer, boom.
>
> Is this possibly related to the issues that are discussed in another
> thread? We're seeing problems while unlinking large files (usually get
> it within some hours with 200MB files, but couldn't yet reproduce it
> with 20MB.)
I don't think this is related (BTW: I've run your test for 5 hours
without any luck ;( Maybe I'll try again for some longer time...).

Honza
--
Jan Kara <jack@suse.cz>
SuSE CR Labs