Re: Does our Kernel PNFSD-Server supports recurring layout_get with open_state_id

[Benny Halevy <bhalevy@xxxxxxxxxx>]

On 2012-05-24 16:49, Boaz Harrosh wrote:
> On 05/24/2012 03:41 PM, Benny Halevy wrote:
> 
>> On 2012-05-24 03:16, Boaz Harrosh wrote:
>>>
>>> Benny hi
>>>
>>> If I remember/understand correctly, there is a mode in the RFC errata
>>> about the layout forgetful-model and a client sending a layout_get with
>>> an open_state_id after he already had previous state (layouts) on the file.
>>>
>>> As I understood this is an indication to the server that client has
>>> "forgotten" all it's layouts on a file, and Server can assume their
>>> return.
>>>
>>> Is my understanding correct?
>>
>> Yes
>>
>>>
>>> If Yes:
>>> 	Did we implement the internal return of all layouts, if above
>>> 	open_state_id is encountered?
>>> 	I thought we did but I can't find this code.
>>
>> True.  This is not implemented yet.
>>
>>>
>>> Currently, I always set ROC so there is no leak. But theoretically
>>> ROC does not have to be set. I'm doing some heavy lifting of
>>> layout_return, and I want to make sure I have not missed a spot.
>>>
>>> If I'm correct that it is needed, and it's missing:
>>> My suggestion for now is that we always set ROC, disregarding FS so not to
>>> leak layouts and therefor inode-refs, until such time that we implement it.
>>
>> According to the new errata the server will have to simulate layout returns in the ROC
>> case on last CLOSE if the (forgetful) client did not explicitly return the layout.
>> This is not implemented either :-(
>>
> 
> 
> Yes Benny it is implemented. I implemented it and you fix a bug I had. See:
> 	nfs4pnfsd.c::pnfsd_roc(...) 
> and it's call site. It is called on last call and all is working well (except some locking
> bugs I'll send a fix to later). Otherwise both exofs and DF would have crapped out for sure.

Duh, you're right of course.

> 
> With ROC set all work well. This is why I say we should set it for now to make sure we do
> not have the above bug.

Yup, see patchset in reply.

Thanks!

Benny

> 
> Thanks
> Boaz
> 
>> Benny
>>
>>>
>>> Thanks
>>> Boaz
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> 
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