Re: [PATCH 1/3] net: Remove support for AIO on sockets

[Christoph Hellwig]

On Thu, May 28, 2026 at 10:56:06AM -0600, Jens Axboe wrote:
> > Where?  And how do make that available to in-kernel users like
> > storage protocols and network file system, which really suffer from
> > the current MSG_SPLICE_PAGES semantics.
> 
> For zero copy, on both the receive and send side. Since we have a proper
> notification channel, that's what we use rather than the hack that is
> the error queue.

Can you point me to that notification channel? 

> >> , and without needing msg_kiocb or the
> > 
> > What do you think is the downside of using a kiocb here like for
> > everything else with async notifications?
> 
> Where would the notifications go?

For userspace: io_uring or the error queue for the synchronous calls.
For in-kernel APIs whatever the callers wants to do by doing it from
ki_complete.

> You'd end up inventing something new
> to propagate them to userspace then.

The main aim here is to have a way to get these completions from
kernelspace to get rid of the current horrors around MSG_SPLICE_PAGES.

> The io_uring side does not rely on
> using msg_kiocb, and iirc that part was only ever used for the crypto
> stuff and largely broken. Which is why I do agree with just yanking it
> out.

I'm not arguing for how msg_kiocb as that is a mess.  But having an
explicit kiocb API like all the other async file operations would
make things a lot simpler.