Re: [PATCH 3/3] io_uring: move struct io_kiocb from task_struct to io_uring_task

[Pavel Begunkov <asml.silence@xxxxxxxxx>]

On 11/3/24 17:49, Jens Axboe wrote:
...
> diff --git a/include/linux/io_uring/cmd.h b/include/linux/io_uring/cmd.h
...
>   	nd->head = prev_nd->head;
> @@ -115,7 +115,7 @@ struct io_kiocb *io_alloc_notif(struct io_ring_ctx *ctx)
>   	notif->opcode = IORING_OP_NOP;
>   	notif->flags = 0;
>   	notif->file = NULL;
> -	notif->task = current;
> +	notif->tctx = current->io_uring;
>   	io_get_task_refs(1);
>   	notif->file_node = NULL;
>   	notif->buf_node = NULL;
> diff --git a/io_uring/poll.c b/io_uring/poll.c
> index 7db3010b5733..56332893a4b0 100644
> --- a/io_uring/poll.c
> +++ b/io_uring/poll.c
> @@ -224,8 +224,7 @@ static int io_poll_check_events(struct io_kiocb *req, struct io_tw_state *ts)
>   {
>   	int v;
>   
> -	/* req->task == current here, checking PF_EXITING is safe */
> -	if (unlikely(req->task->flags & PF_EXITING))
> +	if (unlikely(current->flags & PF_EXITING))
>   		return -ECANCELED

Unlike what the comment says, req->task doesn't have to match current,
in which case the new check does nothing and it'll break in many very
interesting ways.

--
Pavel Begunkov