Re: XFS kernel BUG at fs/buffer.c:470! with 2.6.28.4

From: Jan Kara
Date: Thu Feb 26 2009 - 11:59:31 EST


Argh, forgot the patch...

> > On Tue, 2009-02-10 at 21:43 +1100, Dave Chinner wrote:
> > > On Mon, Feb 09, 2009 at 02:53:08AM -0500, Christoph Hellwig wrote:
> > > > On Sun, Feb 08, 2009 at 11:45:20PM +0100, Alessandro Bono wrote:
> > > > > sure, attached
> > > >
> > > > That would be a missing PagePrivate bit in page_buffers() called from
> > > > end_buffer_async_write. PG_private can only be cleared via drop_buffers
> > > > which requires the page not having PG_writeback set which must be
> > > > set until end_buffer_async_write is done. Very strange, and all this
> > > > is generic code without xfs involvement. Did this happen once
> > > > or can you reproduce it?
> > >
> > > Hmmmm - i wonder if this has anything to do with the writeback fixes
> > > that went into 2.6.28.2? Alessandro, can you revert to 2.6.28.1 (not
> > > plain 2.6.28) and see if you can reproduce the problem?
> >
> > another test another bug
> > kernel 2.6.29-rc4-git4 with DEBUG_PAGEALLOC and CONFIG_DEBUG_LIST
> > enabled (idea taken from a totally unrelated mail from Ingo Molnar to
> > catch a memory corruption), usual bug attached
> > 2.6.27 from ubuntu not survived to rsync
> >
> > btw my first report of a similar problem was with a kernel 2.6.26.6 but
> > at time I was using binary driver for my radeon card and Christoph
> > suggest me that I have to recreate problem without any binary driver
> > maybe it's not a recent regression, it's simply easier to hit with a
> > newer kernel
> >
> > I don't have abandoned idea of a hardware problem but I don't know how
> > to be sure
> >
> > any suggestion?
> Hmm, are you still able to reproduce the problem? As I'm looking into
> registers in your dump, no register really seems to contain sensible page
> flags so it could be some corruption of page pointer. If you are still
> able to reproduce, could you please do so with the attached patch
> applied? It will dump us much more information... Thanks.
>
> Honza
>
> --
> Jan Kara <jack@xxxxxxx>
> SuSE CR Labs
--
Jan Kara <jack@xxxxxxx>
SuSE CR Labs