Re: [PATCH] io_uring: store back buffer in case of failure

On 6/16/21 2:42 PM, Olivier Langlois wrote:

On Tue, 2021-06-15 at 15:51 -0600, Jens Axboe wrote:

quoted

Ditto for this one, don't see it in my email nor on the list.

I can resend you a private copy of this one but as Pavel pointed out,
it contains fatal flaws.

So unless someone can tell me that the idea is interesting and has
potential and can give me some a hint or 2 about how to address the
challenges to fix the current flaws, it is pretty much a show stopper
to me and I think that I am going to let it go...

It'd need to go through some other context, e.g. task context.
task_work_add() + custom handler would work, either buf-select
synchronisation can be reworked, but both would rather be
bulky and not great.

I'm more curious if we ever hit REQ_F_BUFFER_SELECTED branch in
io_clean_op(), because it would just drop the id on the floor...
It might use a WARN_ONCE.

-- 
Pavel Begunkov