On 3/20/25 11:56 PM, Christoph Hellwig wrote:

quoted

I don't know the entire historical context, but I presume sendmsg
did that because there was no other mechanism at the time.

At least aio had been around for about 15 years at the point, but
networking folks tend to be pretty insular and reinvent things.

Yep...

quoted

It seems like Jens suggested that plumbing this through for splice
was a possibility, but sounds like you disagree.

Yes, very strongly.

And that is very much not what I suggested, fwiw.

quoted

As mentioned above and in other messages, it seems like it is
possible to improve the networking parts of splice (and therefore
sendfile) to make them safer to use without introducing a new system
call.

Are you saying that you are against doing that, even if the code is
network specific (but lives in fs/)?

Yes.

Please take the work and integrate it with the kiocb-based system
we use for all other in-kernel I/O that needs completion notifications
and which makes it trivial to integate with io_uring instead of
spreading an imcompatible and inferior event system.

Exactly, this is how we do async IO elsewhere, not sure why networking
needs to be special here, and definitely not special in a good way.

-- 
Jens Axboe