xfs
[Top] [All Lists]

Re: [xfs-masters] 2.6.29-rc: kernel BUG at fs/xfs/support/debug.c:108

To: Alexander Beregalov <a.beregalov@xxxxxxxxx>
Subject: Re: [xfs-masters] 2.6.29-rc: kernel BUG at fs/xfs/support/debug.c:108
From: Dave Chinner <david@xxxxxxxxxxxxx>
Date: Tue, 13 Jan 2009 08:18:48 +1100
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>, xfs-masters@xxxxxxxxxxx, xfs@xxxxxxxxxxx, kernel-testers@xxxxxxxxxxxxxxx
In-reply-to: <a4423d670901120008j728af9cdrbed8bbb938117ea3@xxxxxxxxxxxxxx>
Mail-followup-to: Alexander Beregalov <a.beregalov@xxxxxxxxx>, Christoph Hellwig <hch@xxxxxxxxxxxxx>, xfs-masters@xxxxxxxxxxx, xfs@xxxxxxxxxxx, kernel-testers@xxxxxxxxxxxxxxx
References: <a4423d670901091511y68a53808rfaab8148526224c6@xxxxxxxxxxxxxx> <a4423d670901100419s2ae106bexac1a538caf654153@xxxxxxxxxxxxxx> <20090110143924.GA25900@xxxxxxxxxxxxx> <a4423d670901100709v1e7ce0bfs167547c5001787ac@xxxxxxxxxxxxxx> <20090110152803.GA7469@xxxxxxxxxxxxx> <20090110221459.GA8873@orion> <20090111104659.GB8071@disturbed> <a4423d670901111648w26e86baajcf7b6d98ff37d043@xxxxxxxxxxxxxx> <20090112034550.GI8071@disturbed> <a4423d670901120008j728af9cdrbed8bbb938117ea3@xxxxxxxxxxxxxx>
User-agent: Mutt/1.5.18 (2008-05-17)
On Mon, Jan 12, 2009 at 11:08:55AM +0300, Alexander Beregalov wrote:
> 2009/1/12 Dave Chinner <david@xxxxxxxxxxxxx>:
> > On Mon, Jan 12, 2009 at 03:48:13AM +0300, Alexander Beregalov wrote:
> >> > Hmmmm - this might be getting closer to the source of the bug.
> >> > It's being detecting when reading in the buffer to do a left shift
> >> > now, not during the delete of a record.
> >> >
> >> > I'd suggest that you treat this as the same failure and continue
> >> > the bisect to try to find when no problems show up at all.
> >>
> >> 687b890a184fef263ebb773926e1f4aa69240d01 is the first bad commit.
> >
> >    [XFS] implement generic xfs_btree_lshift
> >
> >    Make the btree left shift code generic. Based on a patch from David
> >    Chinner with lots of changes to follow the original btree implementations
> >    more closely. While this loses some of the generic helper routines for
> >    inserting/moving/removing records it also solves some of the one off bugs
> >    in the original code and makes it easier to verify.
> >
> >> Does it make sense?
> >
> > Yes, a bug in that patch could corrupt the btree in memory which we then 
> > trip
> > over later in delrec before it has been written to disk.
> >
> > Thank you for isolating the problem to that commit - it greatly narrows down
> > the amount of code we need to search to find the bug. I'll have a look 
> > tonight
> > to see if I can spot the problem.
> 
> It seems 9eaead5 (implement generic xfs_btree_rshift) is really guilty, unless
> the bug "XFS internal error xfs_btree_check_lblock at line 200 of file
> fs/xfs/xfs_btree.c:"
> which I posted 5 hours ago is completely different from the original
> bug message.
> I can not reproduce the bug on 278d0ca14.

Ok, Thanks for clarifying. ;)

I'll have a look through the rshift patch and try to find what
we broke by inspection.

Cheers,

Dave.
-- 
Dave Chinner
david@xxxxxxxxxxxxx

<Prev in Thread] Current Thread [Next in Thread>