Re: Btrfs progs release 4.1.1

[Marc MERLIN <marc@merlins.org>]

On Thu, Jul 23, 2015 at 01:55:59PM +0200, David Sterba wrote:
> On Sat, Jul 11, 2015 at 06:02:29PM -0700, Marc MERLIN wrote:
> > Are you interested in crash reports for fsck?
> > 
> > If so, see my recent message:
> > 
> > On Mon, Jul 06, 2015 at 02:21:56PM -0700, Marc MERLIN wrote:
> > > 
> > > myth:~# btrfs check --repair /dev/mapper/crypt_sdd1 
> > > enabling repair mode
> > > Checking filesystem on /dev/mapper/crypt_sdd1
> > > UUID: 024ba4d0-dacb-438d-9f1b-eeb34083fe49
> > > checking extents
> > > cmds-check.c:4486: add_data_backref: Assertion `back->bytes != max_size` failed.
> 
> The bugon was added by Josef in commit 650e656a8b9c1fbe4e to
> (https://git.kernel.org/kdave/btrfs-progs/c/650e656a8b9c1fbe4ec)
> 
> but I don't thing that your filesystem is affected by the described bug,
> rather that it tripped over some other inconsistency in backrefs.
> 
> > > I can mount with -o ro without it crashing, but if I drop ro, it then
> > > tries to do something and crashes, and unfortunately the error doesn't
> > > make it to syslog
> > > 
> > > Screenshot: http://marc.merlins.org/tmp/btrfs_crash.jpg
> 
> So it's 32bit system, 3.19.8, crashing during snapshot deletion and
> backref walking. EIP is in do_walk_down+0x142. I've tried to match it to
> the sources on a local 32bit build, but it does not point to the
> expected crash site:

Thanks for looking.
Unfortunately it's a mythtv where if I put a 64bit kernel, other things
go wrong with the 32bit userland/64bit kernel split.
But I'll put a newer 64bit kernel on it to see what happens and report
back.

Thanks,
Marc
-- 
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                                      .... what McDonalds is to gourmet cooking
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