Re: [RFC PATCH 1/6] rnbd-clt: open code send_msg_open in rnbd_clt_map_device

[Jinpu Wang <jinpu.wang@ionos.com>]

On Mon, Jun 20, 2022 at 5:49 AM Guoqing Jiang <guoqing.jiang@linux.dev> wrote:
>
> Let's open code it in rnbd_clt_map_device, then we can use information
> from rsp to setup gendisk and request_queue in next commits. After that,
> we can remove some members (wc, fua and max_hw_sectors etc) from struct
> rnbd_clt_dev.
>
> Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
> ---
>  drivers/block/rnbd/rnbd-clt.c | 44 +++++++++++++++++++++++++++++++++--
>  1 file changed, 42 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/block/rnbd/rnbd-clt.c b/drivers/block/rnbd/rnbd-clt.c
> index 409c76b81aed..0396532da742 100644
> --- a/drivers/block/rnbd/rnbd-clt.c
> +++ b/drivers/block/rnbd/rnbd-clt.c
> @@ -1562,7 +1562,14 @@ struct rnbd_clt_dev *rnbd_clt_map_device(const char *sessname,
>  {
>         struct rnbd_clt_session *sess;
>         struct rnbd_clt_dev *dev;
> -       int ret;
> +       int ret, errno;
> +       struct rnbd_msg_open_rsp *rsp;
> +       struct rnbd_msg_open msg;
> +       struct rnbd_iu *iu;
> +       struct kvec vec = {
> +               .iov_base = &msg,
> +               .iov_len  = sizeof(msg)
> +       };
>
>         if (exists_devpath(pathname, sessname))
>                 return ERR_PTR(-EEXIST);
> @@ -1582,13 +1589,46 @@ struct rnbd_clt_dev *rnbd_clt_map_device(const char *sessname,
>                 ret = -EEXIST;
>                 goto put_dev;
>         }
> -       ret = send_msg_open(dev, RTRS_PERMIT_WAIT);
> +
> +       rsp = kzalloc(sizeof(*rsp), GFP_KERNEL);
> +       if (!rsp) {
> +               ret = -ENOMEM;
> +               goto del_dev;
> +       }
> +
> +       iu = rnbd_get_iu(sess, RTRS_ADMIN_CON, RTRS_PERMIT_WAIT);
> +       if (!iu) {
> +               ret = -ENOMEM;
> +               kfree(rsp);
> +               goto del_dev;
> +       }
> +       iu->buf = rsp;
> +       iu->dev = dev;
> +       sg_init_one(iu->sgt.sgl, rsp, sizeof(*rsp));
> +
> +       msg.hdr.type    = cpu_to_le16(RNBD_MSG_OPEN);
> +       msg.access_mode = dev->access_mode;
> +       strscpy(msg.dev_name, dev->pathname, sizeof(msg.dev_name));
> +
> +       WARN_ON(!rnbd_clt_get_dev(dev));
> +       ret = send_usr_msg(sess->rtrs, READ, iu,
> +                          &vec, sizeof(*rsp), iu->sgt.sgl, 1,
> +                          msg_open_conf, &errno, RTRS_PERMIT_WAIT);
> +       if (ret) {
> +               rnbd_clt_put_dev(dev);
> +               rnbd_put_iu(sess, iu);
> +               kfree(rsp);
> +       } else {
> +               ret = errno;
> +       }
> +       rnbd_put_iu(sess, iu);
>         if (ret) {
>                 rnbd_clt_err(dev,
>                               "map_device: failed, can't open remote device, err: %d\n",
>                               ret);
>                 goto del_dev;
>         }
> +
looks ok, except this new line seems not needed.

Thx!
>         mutex_lock(&dev->lock);
>         pr_debug("Opened remote device: session=%s, path='%s'\n",
>                  sess->sessname, pathname);
> --
> 2.34.1
>