Re: [PATCH v2 05/12] io_uring: add CQE32 completion processing

[Kanchan Joshi <joshiiitr@gmail.com>]

On Thu, Apr 21, 2022 at 10:44 AM Stefan Roesch <shr@fb.com> wrote:
>
> This adds the completion processing for the large CQE's and makes sure
> that the extra1 and extra2 fields are passed through.
>
> Co-developed-by: Jens Axboe <axboe@kernel.dk>
> Signed-off-by: Stefan Roesch <shr@fb.com>
> Signed-off-by: Jens Axboe <axboe@kernel.dk>
> ---
>  fs/io_uring.c | 55 +++++++++++++++++++++++++++++++++++++++++++--------
>  1 file changed, 47 insertions(+), 8 deletions(-)
>
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index abbd2efbe255..c93a9353c88d 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -2247,18 +2247,15 @@ static noinline bool io_fill_cqe_aux(struct io_ring_ctx *ctx, u64 user_data,
>         return __io_fill_cqe(ctx, user_data, res, cflags);
>  }
>
> -static void __io_req_complete_post(struct io_kiocb *req, s32 res,
> -                                  u32 cflags)
> +static void __io_req_complete_put(struct io_kiocb *req)
>  {
> -       struct io_ring_ctx *ctx = req->ctx;
> -
> -       if (!(req->flags & REQ_F_CQE_SKIP))
> -               __io_fill_cqe_req(req, res, cflags);
>         /*
>          * If we're the last reference to this request, add to our locked
>          * free_list cache.
>          */
>         if (req_ref_put_and_test(req)) {
> +               struct io_ring_ctx *ctx = req->ctx;
> +
>                 if (req->flags & IO_REQ_LINK_FLAGS) {
>                         if (req->flags & IO_DISARM_MASK)
>                                 io_disarm_next(req);
> @@ -2281,8 +2278,23 @@ static void __io_req_complete_post(struct io_kiocb *req, s32 res,
>         }
>  }
>
> -static void io_req_complete_post(struct io_kiocb *req, s32 res,
> -                                u32 cflags)
> +static void __io_req_complete_post(struct io_kiocb *req, s32 res,
> +                                  u32 cflags)
> +{
> +       if (!(req->flags & REQ_F_CQE_SKIP))
> +               __io_fill_cqe_req(req, res, cflags);
> +       __io_req_complete_put(req);
> +}
> +
> +static void __io_req_complete_post32(struct io_kiocb *req, s32 res,
> +                                  u32 cflags, u64 extra1, u64 extra2)
> +{
> +       if (!(req->flags & REQ_F_CQE_SKIP))
> +               __io_fill_cqe32_req(req, res, cflags, extra1, extra2);
> +       __io_req_complete_put(req);
> +}
> +
> +static void io_req_complete_post(struct io_kiocb *req, s32 res, u32 cflags)
>  {
>         struct io_ring_ctx *ctx = req->ctx;
>
> @@ -2293,6 +2305,18 @@ static void io_req_complete_post(struct io_kiocb *req, s32 res,
>         io_cqring_ev_posted(ctx);
>  }
>
> +static void io_req_complete_post32(struct io_kiocb *req, s32 res,
> +                                  u32 cflags, u64 extra1, u64 extra2)
> +{
> +       struct io_ring_ctx *ctx = req->ctx;
> +
> +       spin_lock(&ctx->completion_lock);
> +       __io_req_complete_post32(req, res, cflags, extra1, extra2);
> +       io_commit_cqring(ctx);
> +       spin_unlock(&ctx->completion_lock);
> +       io_cqring_ev_posted(ctx);
> +}
> +
>  static inline void io_req_complete_state(struct io_kiocb *req, s32 res,
>                                          u32 cflags)
>  {
> @@ -2310,6 +2334,21 @@ static inline void __io_req_complete(struct io_kiocb *req, unsigned issue_flags,
>                 io_req_complete_post(req, res, cflags);
>  }
>
> +static inline void __io_req_complete32(struct io_kiocb *req,
> +                                      unsigned int issue_flags, s32 res,
> +                                      u32 cflags, u64 extra1, u64 extra2)
> +{
> +       if (issue_flags & IO_URING_F_COMPLETE_DEFER) {
> +               req->cqe.res = res;
> +               req->cqe.flags = cflags;
> +               req->extra1 = extra1;
> +               req->extra2 = extra2;
> +               req->flags |= REQ_F_COMPLETE_INLINE;

nit: we can use the existing helper (io_req_complete_state) to
populate these fields rather than open-coding.