Re: [Qemu-devel] [PATCH 1/3] virtio_blk: Factor virtio_blk_handle_request out

[Anthony Liguori]

On 01/27/2010 06:12 AM, Kevin Wolf wrote:
> We need a function that handles a single request. Create one by splitting out
> code from virtio_blk_handle_output.
>
> Signed-off-by: Kevin Wolf<address@hidden>
>    

Applied all.  Thanks.

Regards,

Anthony Liguori

> ---
>   hw/virtio-blk.c |   78 ++++++++++++++++++++++++++++++++----------------------
>   1 files changed, 46 insertions(+), 32 deletions(-)
>
> diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c
> index 865352a..82f96e5 100644
> --- a/hw/virtio-blk.c
> +++ b/hw/virtio-blk.c
> @@ -317,46 +317,60 @@ static void virtio_blk_handle_read(VirtIOBlockReq *req)
>       }
>   }
>
> +typedef struct MultiReqBuffer {
> +    BlockRequest        blkreq[32];
> +    int                 num_writes;
> +    BlockDriverState    *old_bs;
> +} MultiReqBuffer;
> +
> +static void virtio_blk_handle_request(VirtIOBlockReq *req,
> +    MultiReqBuffer *mrb)
> +{
> +    if (req->elem.out_num<  1 || req->elem.in_num<  1) {
> +        fprintf(stderr, "virtio-blk missing headers\n");
> +        exit(1);
> +    }
> +
> +    if (req->elem.out_sg[0].iov_len<  sizeof(*req->out) ||
> +        req->elem.in_sg[req->elem.in_num - 1].iov_len<  sizeof(*req->in)) {
> +        fprintf(stderr, "virtio-blk header not in correct element\n");
> +        exit(1);
> +    }
> +
> +    req->out = (void *)req->elem.out_sg[0].iov_base;
> +    req->in = (void *)req->elem.in_sg[req->elem.in_num - 1].iov_base;
> +
> +    if (req->out->type&  VIRTIO_BLK_T_FLUSH) {
> +        virtio_blk_handle_flush(req);
> +    } else if (req->out->type&  VIRTIO_BLK_T_SCSI_CMD) {
> +        virtio_blk_handle_scsi(req);
> +    } else if (req->out->type&  VIRTIO_BLK_T_OUT) {
> +        qemu_iovec_init_external(&req->qiov,&req->elem.out_sg[1],
> +                                 req->elem.out_num - 1);
> +        virtio_blk_handle_write(mrb->blkreq,&mrb->num_writes,
> +            req,&mrb->old_bs);
> +    } else {
> +        qemu_iovec_init_external(&req->qiov,&req->elem.in_sg[0],
> +                                 req->elem.in_num - 1);
> +        virtio_blk_handle_read(req);
> +    }
> +}
> +
>   static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
>   {
>       VirtIOBlock *s = to_virtio_blk(vdev);
>       VirtIOBlockReq *req;
> -    BlockRequest blkreq[32];
> -    int num_writes = 0;
> -    BlockDriverState *old_bs = NULL;
> +    MultiReqBuffer mrb = {
> +        .num_writes = 0,
> +        .old_bs = NULL,
> +    };
>
>       while ((req = virtio_blk_get_request(s))) {
> -        if (req->elem.out_num<  1 || req->elem.in_num<  1) {
> -            fprintf(stderr, "virtio-blk missing headers\n");
> -            exit(1);
> -        }
> -
> -        if (req->elem.out_sg[0].iov_len<  sizeof(*req->out) ||
> -            req->elem.in_sg[req->elem.in_num - 1].iov_len<  sizeof(*req->in)) {
> -            fprintf(stderr, "virtio-blk header not in correct element\n");
> -            exit(1);
> -        }
> -
> -        req->out = (void *)req->elem.out_sg[0].iov_base;
> -        req->in = (void *)req->elem.in_sg[req->elem.in_num - 1].iov_base;
> -
> -        if (req->out->type&  VIRTIO_BLK_T_FLUSH) {
> -            virtio_blk_handle_flush(req);
> -        } else if (req->out->type&  VIRTIO_BLK_T_SCSI_CMD) {
> -            virtio_blk_handle_scsi(req);
> -        } else if (req->out->type&  VIRTIO_BLK_T_OUT) {
> -            qemu_iovec_init_external(&req->qiov,&req->elem.out_sg[1],
> -                                     req->elem.out_num - 1);
> -            virtio_blk_handle_write(blkreq,&num_writes, req,&old_bs);
> -        } else {
> -            qemu_iovec_init_external(&req->qiov,&req->elem.in_sg[0],
> -                                     req->elem.in_num - 1);
> -            virtio_blk_handle_read(req);
> -        }
> +        virtio_blk_handle_request(req,&mrb);
>       }
>
> -    if (num_writes>  0) {
> -        do_multiwrite(old_bs, blkreq, num_writes);
> +    if (mrb.num_writes>  0) {
> +        do_multiwrite(mrb.old_bs, mrb.blkreq, mrb.num_writes);
>       }
>
>       /*
>