mkdir-dup test flapping

[Jeremy Allison]

On Tue, Mar 01, 2016 at 04:17:12PM +1300, Andrew Bartlett wrote:
> G'Day Jeremy,
> 
> In testing Samba on the Catalyst Cloud, we more often than not get a
> flapping test failure, rather than our real issues.  One that has come
> particularly to my attention is
> 
> [438(1936)/1885 at 1h5m1s] samba3.smb2.create(ad_dc)
> Testing SMB2 Create Directory with multiple connections
> waiting for replies
> UNEXPECTED(failure): samba3.smb2.create.mkdir-dup(ad_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)
> 
> This is your code in 969d043596c0a382325d54d16dbd5e049f884fa9 testing  
> https://bugzilla.samba.org/show_bug.cgi?id=11486
> 
> ad_dc here uses the smbd file server (no, this isn't NTVFS :-)
> 
> Can you look into this for us, and perhaps see if the code could be
> made more robust during the loop?  I'm very happy to get you access to
> a suitable machine to show the issue, but sadly it only seems to
> reproduce easily in a full autobuild (along with all the other flapping
> tests).

Hmmm. That's very strange. It's as simple
as it can be inside the loop. Just tries to create
the same directory twice using NTCREATEX_DISP_OPEN_IF
once on each connection. Expects one request to
return NTCREATEX_ACTION_CREATED, the other one
to return NTCREATEX_ACTION_EXISTED, but doesn't
care which is which.

Neither should ever return NT_STATUS_ACCESS_DENIED...