Re: [PATCH 1/2] io_uring/uring_cmd: copy SQE before issue_blocking punt

On Thu, Jul 2, 2026 at 1:41 AM Yang Xiuwei <[email protected]> wrote:
>
> io_uring_cmd_issue_blocking() punts to io-wq without copying the SQE
> off the submission queue, unlike the -EAGAIN and fallback paths. Copy
> the SQE into async data before queuing the work.

Add a Fixes tag?
Fixes: ecf47d452ced ("io_uring/uring_cmd: implement ->sqe_copy() to
avoid unnecessary copies")

>
> Signed-off-by: Yang Xiuwei <[email protected]>
> ---
>  io_uring/uring_cmd.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
> index 7b25dcd9d05f..fe32311b2e51 100644
> --- a/io_uring/uring_cmd.c
> +++ b/io_uring/uring_cmd.c
> @@ -326,6 +326,10 @@ void io_uring_cmd_issue_blocking(struct io_uring_cmd *ioucmd)
>  {
>         struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
>
> +       if (!(req->flags & REQ_F_SQE_COPIED)) {
> +               io_uring_cmd_sqe_copy(req);
> +               req->flags |= REQ_F_SQE_COPIED;

Isn't this too late to copy the SQE? io_uring_cmd_issue_blocking() is
called from the blk_cmd_complete() task work, which is already
asynchronous with respect to the submission. So the kernel will
already returned the SQ slot to userspace.

Best,
Caleb

> +       }
>         io_req_queue_iowq(req);
>  }
>
> --
> 2.25.1
>
>