[GEDI] gfapi: possible approaches to get lk_owner support

[Niels de Vos]

On Wed, Oct 04, 2017 at 05:03:35PM +0530, Soumya Koduri wrote:
> Thank you all for your comments. Bases on your inputs, I did some POC on
> approach(3) i.e, to store lkowner in glfd itself. API syntax and sample test
> case are updated in [1]. Will refine the patch a bit more before calling for
> formal review. Please let me know if there are any objections.
> 
> 
> > Jiffin's patch does a glfs_dup, if that creates a separate glfd that we
> > can then set lock owner differently on, then it would work.
> > 
> 
> This seems to be a bit tricky. Each gfapi's glfd correspond to a unique fd
> on gluster server side. However if used glfs_dup, same server fd will be
> used for both those glfd objects but with extra reference taken.
> 
> As far as the locks are concerned, looks like when we close a fd, server
> expects us to pass on lkowner as well and it cleans up locks with only that
> lkowner. That way we are right now safe to use glfs_dup and set another
> lkowner on the duplicate glfd returned.
> 
> But if in case in future there comes any requirement to close all the locks
> tied to an fd, then the locks taken on both the glfd's shall be lost.

Sounds good to me. I've left some initial review comments on your patch
already.

Thanks!
Niels


> 
> Thanks,
> Soumya
> 
> [1] https://review.gluster.org/18429
>