Re: [PATCH 0/5] add initial io_uring_cmd support for sockets

Keith Busch
2023-04-06T16:41:52Z

On Thu, Apr 06, 2023 at 07:43:26AM -0700, Breno Leitao wrote:
> This patchset creates the initial plumbing for a io_uring command for
> sockets.
>
> For now, create two uring commands for sockets, SOCKET_URING_OP_SIOCOUTQ
> and SOCKET_URING_OP_SIOCINQ. They are similar to ioctl operations
> SIOCOUTQ and SIOCINQ. In fact, the code on the protocol side itself is
> heavily based on the ioctl operations.

Do you have asynchronous operations in mind for a future patch? The io_uring
command infrastructure makes more sense for operations that return EIOCBQUEUED,
otherwise it doesn't have much benefit over ioctl.

> In order to test this code, I created a liburing test, which is
> currently located at [1], and I will create a pull request once we are
> good with this patch.
>
> I've also run test/io_uring_passthrough to make sure the first patch
> didn't regressed the NVME passthrough path.
>
> This patchset is a RFC for two different reasons:
> * It changes slighlty on how IO uring command operates. I.e, we are
> now passing the whole SQE to the io_uring_cmd callback (instead of
> an opaque buffer). This seems to be more palatable instead of
> creating some custom structure just to fit small parameters, as in
> SOCKET_URING_OP_SIOC{IN,OUT}Q. Is this OK?

I think I'm missing something from this series. Where is the io_uring_cmd
change to point to the sqe?