Re: [PATCH 2/3] NFSv4.1 mark layout when already returned

[Boaz Harrosh <bharrosh@panasas.com>]

On 06/11/2012 06:52 PM, Adamson, Andy wrote:
<>

>>
>> Yeah, right now pnfs_return_layout always returns the whole layout
>> so this patch works.  Boaz's point (I think) was that marking the whole layout
>> as returned in the generic layer will prevent returning of layout segments
>> by the objects layout.
> 
> Yep. I agree that _pnfs_return_layout needs to operate on an input range, and 
> should wait for all lseg references - the "normal" behavior. 
> 


You mean the normal "error handling behavior" right?

> Then, after that is done,
> I will write a patch to allow the file layout driver to call _pnfs_return_layout in
> "fence mode" e.g returning the whole layout, and not waiting for the last lseg reference.
> 


This one I do not understand. And am really trying. please be slow with me?
1. What does it means "whole layout" Is that just a short hand for
   "all segments" ?
2. What is "fence mode" LAYOUTRETURN. where did you take this one from?
3. How does "fence mode" permits a client to use a layout segment after
   the send of LAYOUTRETURN. Since that is what we do (to date) because
   of race.

Thanks
Boaz

> -->Andy