Bug#964494: File system corruption with ext3 + kernel-4.19.0-9-amd64

[Sarah Newman <srn@prgmr.com>]

On 7/20/20 11:24 AM, Hans van Kranenburg wrote:
> Hi,
>
> On Wed, 15 Jul 2020 20:52:40 -0700 Sarah Newman <srn@prgmr.com> wrote:
> > On 7/7/20 8:13 PM, Ben Hutchings wrote:
> > > Control: reassign -1 src:linux
> > > Control: tag -1 moreinfo
> > >
> > > On Tue, 2020-07-07 at 17:30 -0700, Sarah Newman wrote:
> > > > Package: linux-signed-amd64
> > > > Version: 4.19.0-9-amd64
> > > >
> > > > We've had two separate reports now of debian buster users running
> > > > 4.19.0-9-amd64 who experienced serious file system corruption.
> > >
> > > Which version?  (I.e. what does "uname -v" or
> > > "dpkg -s linux-image-4.19.0-9-amd64" say?)
> > >
> > > > - Both were using ext3
> > > > - Both are running Xen HVM, but I do not have reason to believe this to be related
> >
> > [...]
>
> I have servers which run 4.19.118-2 as dom0 kernel and a Xen 4.11.4-1
> rebuild for Buster.
>
> One example is a smallish 6-server cluster that got a reboot cycle 48
> days ago.
>
> It contains a few heavily loaded domUs with 4.19.118 or 4.19.131 based
> kernels.
>
> No problems or disk corruption or anything is seen yet. dom0 filesystem
> is ext4, domUs use a mix of ext4 and btrfs (over iscsi). So, no ext3
> anywhere.
>
> We haven't got bug reports against Debian Xen packages in the BTS about
> this.
>
> I have not yet tried to make an ext3 fs on a block device in a test domU
> and then have it do things with the fs and reboot it now and then. If
> wanted, I can do that and see if there's any problem after a week or
> two. Just to add chaos to help correlating.
>
> FWIW,
> Hans

We've had 9 reports of users running 4.19.0-9-amd64 total, only 2 with ext3, no uptimes longer than maybe 5 weeks for the ext3 + 4.19.0-9-amd64 users. 
No more reported failures.

Our attempts to reproduce so far have not been successful, but that might be because we were running a debug kernel build and I think there may have 
been a deadlock in between depot_lock and console_owner which killed the tests.

I'm not sure what the next steps are here, but it sounds like ext4 has not shown any problems.

--Sarah