mkdir-dup test flapping

[Jeremy Allison]

On Thu, Mar 10, 2016 at 02:34:36PM +1300, Andrew Bartlett wrote:
> > Let me know what you think !
> 
> We are puzzled.  While it ran successfully 1000 times locally (in the
> same testenv environment), when run in make test on the Catalyst Cloud,
> with your patch it failed in 2/10 of the runs I started this morning:
> 
> Testing SMB2 Create Directory with multiple connections
> waiting for replies
> UNEXPECTED(failure): samba3.smb2.create.mkdir-dup(nt4_dc)
> REASON: Exception: Exception: ../source4/torture/smb2/create.c:1628:
> File 1 returned status NT_STATUS_ACCESS_DENIED
> 
> FAILED (1 failures, 0 errors and 0 unexpected successes in 0
> testsuites)
> 
> A summary with detailed information can be found in:
>   ./bin/ab/summary
> 
> commit 68708672142f00dd59f91589d57fb3b3a593ab80
> Author: Jeremy Allison <jra at samba.org>
> Date:   Wed Mar 9 09:43:09 2016 -0800
> 
>     s3: smbd: Fix error in mkdir race condition detection.
>     
>     BUG: https://bugzilla.samba.org/show_bug.cgi?id=11780
>     
>     The smb2.create.mkdir-dup test creates a race, and against an AD DC
>     this can cause a flapping test if the lstat() and stat() calls are
>     made either side of the chown() due to creation of a file by
>     administrator.
>     
>     We know when we've hit the race, so relax the check_same_stat()
>     check in that specific case.
>     
>     Fix based on an original patch by Andrew Bartlett <abartlet at samba.o
> rg>
>     and Douglas Bagnall <douglas.bagnall at catalyst.net.nz>.
> 
> 
> Sorry to drop this on you at the end of the work day.  
> 
> I've started a number of runs with our patch, but I don't expect a
> different result.  We have this one on the line, but it's still
> fighting as we reel it in...

Can you get me a debug level 10 log showing which
of the ACCESS_DENIED is triggering ?

Then I can try and concoct a scenario that might
allow that to happen :-).