Re: [BUG] xfs/305 hangs 4.10-rc4 kernel

[Brian Foster <bfoster@redhat.com>]

On Sat, Feb 04, 2017 at 07:47:00PM +0800, Eryu Guan wrote:
> On Mon, Jan 30, 2017 at 04:59:52PM -0500, Brian Foster wrote:
> > 
> > I reproduced an xfs_wait_buftarg() unmount hang once that looks like a
> > separate issue (occurs after the test, long after quotaoff has
> > completed). I haven't reproduced that one again nor the original hang in
> > 100+ iterations so far. Care to give the following a whirl in your
> > environment? Thanks.
> 
> I applied your test patch on top of 4.10-rc4 stock kernel and hit
> xfs/305 hang at 82nd iteration. I attached the dmesg and sysrq-w log.
> You can login the same RH internal test host if that's helpful, I left
> the host running in the hang state.
> 

Ok, that's not too surprising. It does look like we are in some kind of
live lock situation. xfs_quota is spinning on the dqpurge and two or
three fsstress workers are spinning on xfs_iget() retries via bulkstat.

I'm going to hard reboot this box and try to restart this test with some
customized tracepoints to try and get more data..

Brian

> Thanks,
> Eryu