Re: [PATCH] virtio_blk: corrent types for status handling

[Jason Wang]

On Mon, Oct 25, 2021 at 3:59 PM Michael S. Tsirkin <mst@xxxxxxxxxx> wrote:
>
> virtblk_setup_cmd returns blk_status_t in an int, callers then assign it
> back to a blk_status_t variable. blk_status_t is either u32 or (more
> typically) u8 so it works, but is inelegant and causes sparse warnings.
>
> Pass the status in blk_status_t in a consistent way.
>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Fixes: b2c5221fd074 ("virtio-blk: avoid preallocating big SGL for data")
> Cc: Max Gurtovoy <mgurtovoy@xxxxxxxxxx>
> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>

Acked-by: Jason Wang <jasowang@xxxxxxxxxx>

> ---
>  drivers/block/virtio_blk.c | 14 ++++++++------
>  1 file changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> index c336d9bb9105..c7d05ff24084 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -208,8 +208,9 @@ static void virtblk_cleanup_cmd(struct request *req)
>                 kfree(bvec_virt(&req->special_vec));
>  }
>
> -static int virtblk_setup_cmd(struct virtio_device *vdev, struct request *req,
> -               struct virtblk_req *vbr)
> +static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev,
> +                                     struct request *req,
> +                                     struct virtblk_req *vbr)
>  {
>         bool unmap = false;
>         u32 type;
> @@ -317,14 +318,15 @@ static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx,
>         unsigned long flags;
>         unsigned int num;
>         int qid = hctx->queue_num;
> -       int err;
>         bool notify = false;
> +       blk_status_t status;
> +       int err;
>
>         BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems);
>
> -       err = virtblk_setup_cmd(vblk->vdev, req, vbr);
> -       if (unlikely(err))
> -               return err;
> +       status = virtblk_setup_cmd(vblk->vdev, req, vbr);
> +       if (unlikely(status))
> +               return status;
>
>         blk_mq_start_request(req);
>
> --
> MST
>