Re: [PATCH RFC v2 1/3] io_uring: use an enumeration for io_uring_register(2) opcodes

Pavel Begunkov
2020-07-16T20:18:33Z

On 16/07/2020 15:48, Stefano Garzarella wrote:
> The enumeration allows us to keep track of the last
> io_uring_register(2) opcode available.
>
> Behaviour and opcodes names don't change.
>
> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> ---
> include/uapi/linux/io_uring.h | 27 ++++++++++++++++-----------
> 1 file changed, 16 insertions(+), 11 deletions(-)
>
> diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
> index 7843742b8b74..efc50bd0af34 100644
> --- a/include/uapi/linux/io_uring.h
> +++ b/include/uapi/linux/io_uring.h
> @@ -253,17 +253,22 @@ struct io_uring_params {
> /*
> * io_uring_register(2) opcodes and arguments
> */
> -#define IORING_REGISTER_BUFFERS 0
> -#define IORING_UNREGISTER_BUFFERS 1
> -#define IORING_REGISTER_FILES 2
> -#define IORING_UNREGISTER_FILES 3
> -#define IORING_REGISTER_EVENTFD 4
> -#define IORING_UNREGISTER_EVENTFD 5
> -#define IORING_REGISTER_FILES_UPDATE 6
> -#define IORING_REGISTER_EVENTFD_ASYNC 7
> -#define IORING_REGISTER_PROBE 8
> -#define IORING_REGISTER_PERSONALITY 9
> -#define IORING_UNREGISTER_PERSONALITY 10
> +enum {
> + IORING_REGISTER_BUFFERS,
> + IORING_UNREGISTER_BUFFERS,
> + IORING_REGISTER_FILES,
> + IORING_UNREGISTER_FILES,
> + IORING_REGISTER_EVENTFD,
> + IORING_UNREGISTER_EVENTFD,
> + IORING_REGISTER_FILES_UPDATE,
> + IORING_REGISTER_EVENTFD_ASYNC,
> + IORING_REGISTER_PROBE,
> + IORING_REGISTER_PERSONALITY,
> + IORING_UNREGISTER_PERSONALITY,
> +
> + /* this goes last */
> + IORING_REGISTER_LAST
> +};

It breaks userspace API. E.g.

#ifdef IORING_REGISTER_BUFFERS

>
> struct io_uring_files_update {
> __u32 offset;
>

--
Pavel Begunkov