Samba oplock level II problem

[Pavel Shilovsky]

2011/2/5 Pavel Shilovsky <piastryyy at gmail.com>:
> 2011/2/5 Jeremy Allison <jra at samba.org>:
>> On Fri, Feb 04, 2011 at 02:37:06PM -0800, Jeremy Allison wrote:
>>> On Fri, Feb 04, 2011 at 11:11:54PM +0300, Pavel Shilovsky wrote:
>>>
>>> > I think you missed new byte-range locking part.
>>>
>>> Yes you are correct.
>>>
>>> > Now we may have the
>>> > following situation:
>>> > 1) f1 = open(file) # exclusive oplock is granted to f1
>>> > 2) lock(f1) # set byte-range lock via f1
>>> > 3) f2 = open(file) # f1 gets oplock break with level2 but no oplock is
>>> > granted to f2 (because lock count more 0) - we have 'no oplock' for f2
>>> > and 'level2' oplock for f1 in share mode entries
>>>
>>> Ah, that's a bug in your original patch then - it's
>>> refusing the oplock in the wrong place (or at least
>>> not forcing an overall downgrade). We need to
>>> make sure we can't have that situation where the no_oplock
>>> and level2 oplock co-exist in the share mode entries without
>>> it being in a transitional stage to "no oplock" over all
>>> entries.
>>>
>>> I'll take a closer look at the underlying issue.
>>
>> Ok, the following patch (to 3.6 and master) fixes
>> the problem. It moves your original patch into smbd/open.c
>> from smbd/oplock.c as we need to decide before we set
>> share mode entries.
>>
>> I'll need to work on the 3.5.x patch you posted, that
>> will have to be moved also but that's a harder change
>> as I already refactored the 3.6.x code to make this
>> clearer.
>>
>> Jeremy.
>>
>
> If I understand you right and we should set FAKE_LEVEL_II_OPLOCK to f2
> on the line 3 of my example, I agree with your changes. So, as the
> result for my example, we have two entries:
> 1) f1 - level2 oplock;
> 2) f2 - fake leve2 oplock.
>
> So, in this case the check for level2_oplock_type in
> contend_level2_oplocks_begin_default is correct.
>
> I can respin my patch (move brlocks check into delay_for_oploks in
> open.c) to make it according to the note above.
>
> --
> Best regards,
> Pavel Shilovsky.
>

I recreated the patch for 3.5.x:
http://git.etersoft.ru/people/piastry/packages/?p=samba4.git;a=commitdiff;h=0ce27557e831490fe31493c339e546078f504c51

-- 
Best regards,
Pavel Shilovsky.