Re: [PATCH v3 4/4] io_uring: add support for zone-append

[Kanchan Joshi]

On Wed, Jul 08, 2020 at 10:38:44AM -0600, Jens Axboe wrote:
> On 7/8/20 10:33 AM, Matthew Wilcox wrote:
> > On Wed, Jul 08, 2020 at 06:08:12PM +0200, Javier GonzÃlez wrote:
> > > > I just wanted to get clarification there, because to me it sounded like
> > > > you expected Kanchan to do it, and Kanchan assuming it "was sorted". I'd
> > > > consider that a prerequisite for the append series as far as io_uring is
> > > > concerned, hence _someone_ needs to actually do it ;-)
> >
> > I don't know that it's a prerequisite in terms of the patches actually
> > depend on it.  I appreciate you want it first to ensure that we don't bloat
> > the kiocb.
>
> Maybe not for the series, but for the io_uring addition it is.
>
> > > I believe Kanchan meant that now the trade-off we were asking to
> > > clear out is sorted.
> > >
> > > We will send a new version shortly for the current functionality - we
> > > can see what we are missing on when the uring interface is clear.
> >
> > I've started work on a patch series for this.  Mostly just waiting for
> > compilation now ... should be done in the next few hours.
>
> Great!

Jens, Matthew - I'm sorry for creating the confusion. By "looks sorted"
I meant the performance-implications and the room-for-pointer. For the
latter I was thinking to go by your suggestion not to bloat the kiocb, and
use io_kiocb instead.
If we keep, there will be two paths to update that pointer, one using
ki_complete(....,ret2) and another directly - which does not seem good.

On a different note: trimming kiocb by decoupling ki_complete work looks
too good to be done by me :-)