On Tue, Apr 18, 2023 at 2:53 PM Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> wrote:
>
> virtnet_build_xdp_buff_mrg() and virtnet_xdp_handler() auto
> release xdp shinfo then the caller no need to careful the xdp shinfo.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
> ---
> drivers/net/virtio_net.c | 29 +++++++++++++++++------------
> 1 file changed, 17 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index e2eade87d2d4..266c1670beda 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -834,7 +834,7 @@ static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp,
> xdpf = xdp_convert_buff_to_frame(xdp);
> if (unlikely(!xdpf)) {
> netdev_dbg(dev, "convert buff to frame failed for xdp\n");
> - return VIRTNET_XDP_RES_DROP;
> + goto drop;
> }
>
> err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
> @@ -842,7 +842,7 @@ static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp,
> xdp_return_frame_rx_napi(xdpf);
> } else if (unlikely(err < 0)) {
> trace_xdp_exception(dev, xdp_prog, act);
> - return VIRTNET_XDP_RES_DROP;
> + goto drop;
> }
>
> *xdp_xmit |= VIRTIO_XDP_TX;
> @@ -852,7 +852,7 @@ static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp,
> stats->xdp_redirects++;
> err = xdp_do_redirect(dev, xdp, xdp_prog);
> if (err)
> - return VIRTNET_XDP_RES_DROP;
> + goto drop;
>
> *xdp_xmit |= VIRTIO_XDP_REDIR;
> return VIRTNET_XDP_RES_CONSUMED;
> @@ -864,8 +864,12 @@ static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp,
> trace_xdp_exception(dev, xdp_prog, act);
> fallthrough;
> case XDP_DROP:
> - return VIRTNET_XDP_RES_DROP;
> + break;
> }
> +
> +drop:
> + put_xdp_frags(xdp);
> + return VIRTNET_XDP_RES_DROP;
> }
Patch looks correct but we end up some inconsistency here.
frags are automatically released.
but the page still needs to be freed by the caller?
Thanks
>
> static unsigned int virtnet_get_headroom(struct virtnet_info *vi)
> @@ -1201,7 +1205,7 @@ static int virtnet_build_xdp_buff_mrg(struct net_device *dev,
> dev->name, *num_buf,
> virtio16_to_cpu(vi->vdev, hdr->num_buffers));
> dev->stats.rx_length_errors++;
> - return -EINVAL;
> + goto err;
> }
>
> stats->bytes += len;
> @@ -1220,7 +1224,7 @@ static int virtnet_build_xdp_buff_mrg(struct net_device *dev,
> pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
> dev->name, len, (unsigned long)(truesize - room));
> dev->stats.rx_length_errors++;
> - return -EINVAL;
> + goto err;
> }
>
> frag = &shinfo->frags[shinfo->nr_frags++];
> @@ -1235,6 +1239,10 @@ static int virtnet_build_xdp_buff_mrg(struct net_device *dev,
>
> *xdp_frags_truesize = xdp_frags_truesz;
> return 0;
> +
> +err:
> + put_xdp_frags(xdp);
> + return -EINVAL;
> }
>
> static void *mergeable_xdp_prepare(struct virtnet_info *vi,
> @@ -1364,7 +1372,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
> err = virtnet_build_xdp_buff_mrg(dev, vi, rq, &xdp, data, len, frame_sz,
> &num_buf, &xdp_frags_truesz, stats);
> if (unlikely(err))
> - goto err_xdp_frags;
> + goto err_xdp;
>
> act = virtnet_xdp_handler(xdp_prog, &xdp, dev, xdp_xmit, stats);
>
> @@ -1372,7 +1380,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
> case VIRTNET_XDP_RES_PASS:
> head_skb = build_skb_from_xdp_buff(dev, vi, &xdp, xdp_frags_truesz);
> if (unlikely(!head_skb))
> - goto err_xdp_frags;
> + goto err_xdp;
>
> rcu_read_unlock();
> return head_skb;
> @@ -1382,11 +1390,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
> goto xdp_xmit;
>
> case VIRTNET_XDP_RES_DROP:
> - break;
> + goto err_xdp;
> }
> -err_xdp_frags:
> - put_xdp_frags(&xdp);
> - goto err_xdp;
> }
> rcu_read_unlock();
>
> --
> 2.32.0.3.g01195cf9f
>
