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

[Eryu Guan <eguan@redhat.com>]

On Wed, Jul 26, 2017 at 06:35:03AM -0400, Brian Foster wrote:
> On Wed, Jul 26, 2017 at 01:09:52PM +0800, Eryu Guan wrote:
> > Hi Brian,
> > 
> > [sorry for bringing up an old thread, but this seems relavent]
> > 
[snip]
> > 
> > Is xfs/305 supposed to pass with 4.13-rc2 kernel now? I know there're
> > some quota patches went in XFS recently, but I'm not sure if there's any
> > known leftover bug.
> > 
> > Anyway, I hit a test hang with 4.13-rc2 kernel with xfs/305 again, test
> > configuration is rmapbt XFS with 4k block size on ppc64le host. But I
> > haven't tried to reproduce it yet. Just want to confirm with you first.
> > 
> 
> I believe it is still possible for quotaoff to deadlock the log. It is
> not shown below, but I assume you have a blocked xfs_quota process
> attempting to run a quotaoff..? How big is your fs/log?

I'm not sure if there's a quotaoff blocked too, that's all I have for
now, this was an automated test job and it didn't print any sysrq-w
output as expected. The fs is 15G but I don't know much about the log,
the host host was returned to the test pool..

> 
> I sent a patch a while ago, but it wasn't safe because it could
> potentially lead to nested transactions in the quotaoff context. We
> don't have a proper fix for this as of yet.

Ok, thanks! At least this isn't something totally surprising people,
I'll see if I can hit it again in future test runs.

Thanks,
Eryu