Re: [PATCH 2/2] io_uring: better to use REQ_F_IO_DRAIN for req->flags

[Pavel Begunkov <asml.silence@gmail.com>]

On 11/25/21 09:21, Hao Xu wrote:
> It's better to use REQ_F_IO_DRAIN for req->flags rather than
> IOSQE_IO_DRAIN though they have same value.
> 
> Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
> ---
>   fs/io_uring.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index ae9534382b26..08b1b3de9b3f 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -7095,10 +7095,10 @@ static void io_init_req_drain(struct io_kiocb *req)
>   		 * If we need to drain a request in the middle of a link, drain
>   		 * the head request and the next request/link after the current
>   		 * link. Considering sequential execution of links,
> -		 * IOSQE_IO_DRAIN will be maintained for every request of our
> +		 * REQ_F_IO_DRAIN will be maintained for every request of our

Don't care much, but it's more about the userspace visible behaviour, and so
talks about IOSQE_IO_DRAIN.

Looks good,

>   		 * link.
>   		 */
> -		head->flags |= IOSQE_IO_DRAIN | REQ_F_FORCE_ASYNC;
> +		head->flags |= REQ_F_IO_DRAIN | REQ_F_FORCE_ASYNC;
>   		ctx->drain_next = true;
>   	}
>   }
> @@ -7149,7 +7149,7 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
>   		if (unlikely(ctx->drain_next) && !ctx->submit_state.link.head) {
>   			ctx->drain_next = false;
>   			ctx->drain_active = true;
> -			req->flags |= IOSQE_IO_DRAIN | REQ_F_FORCE_ASYNC;
> +			req->flags |= REQ_F_IO_DRAIN | REQ_F_FORCE_ASYNC;
>   		}
>   	}
>   
> 

-- 
Pavel Begunkov