[PATCH] Fix bug #13121 - Non-smbd processes using kernel oplocks can hang smbd

Andrew Bartlett abartlet at samba.org
Mon Nov 27 06:14:05 UTC 2017


On Mon, 2017-11-27 at 09:17 +1300, Gary Lockyer via samba-technical
wrote:
> 
> On 25/11/17 14:54, Jeremy Allison via samba-technical wrote:
> > On Fri, Nov 24, 2017 at 09:42:51AM +1300, Gary Lockyer via samba-technical wrote:
> > > Have been able to get this to fail by running
> > > make TESTS="kernel-oplock" test
> > > in a loop on my dev box.
> > 
> > If it's failing with "Bad child exit code 10"
> > it means the parent open isn't causing a lease
> > break realtime signal in 5 seconds. That seems
> > unlikely
> 
> It is failing with "Bad child exit code 10"
> > 
> > It's *possible* it's a timing related thing,
> > can you check by upping the alarm(5) to alarm(10)
> > using the following patch ?
> > 
> > diff --git a/source4/torture/smb2/oplock.c b/source4/torture/smb2/oplock.c
> > index b6d9f842336..baeac35a791 100644
> > --- a/source4/torture/smb2/oplock.c
> > +++ b/source4/torture/smb2/oplock.c
> > @@ -4876,7 +4876,7 @@ static int do_child_process(int pipefd, const char *name)
> >         }
> >  
> >         /* Ensure the pause doesn't hang forever. */
> > -       alarm(5);
> > +       alarm(10);
> >  
> >         /* Wait for RT_SIGNAL_LEASE. */
> >         ret = pause();
> > 
> 
> I've applied the patch and have kicked off some auto builds.
> 
> > I haven't heard complaints this is flapping on sn-devel
> > which is using:
> > 
> > Linux sn-devel-144 3.13.0-135-generic #184-Ubuntu SMP Wed Oct 18 11:55:51 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
> > 
> > How often have you been able to get this to
> > fail when running in a loop ?
> > 
> 
> Once so far I'll do some more runs and gather some more data.

Jermey,

>From the build output I've seen It isn't looking good so far.  We have
this test fail at least as often as it succeeds on cloud VMs.  Would it
help if we gave you access to such a VM to work on?

Thanks,

Andrew Bartlett

-- 
Andrew Bartlett                       http://samba.org/~abartlet/
Authentication Developer, Samba Team  http://samba.org
Samba Developer, Catalyst IT          http://catalyst.net.nz/services/samba




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