Re: [PATCH net-next 6/8] virtio_net: auto release xdp shinfo

[Jason Wang <jasowang@xxxxxxxxxx>]

在 2023/3/28 20:04, Xuan Zhuo 写道:
> virtnet_build_xdp_buff_mrg() and virtnet_xdp_handler() auto


I think you meant virtnet_xdp_handler() actually?


> 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 a3f2bcb3db27..136131a7868a 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -833,14 +833,14 @@ static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp,
>   		stats->xdp_tx++;
>   		xdpf = xdp_convert_buff_to_frame(xdp);
>   		if (unlikely(!xdpf))
> -			return VIRTNET_XDP_RES_DROP;
> +			goto drop;
>   
>   		err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
>   		if (unlikely(!err)) {
>   			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;
> @@ -850,7 +850,7 @@ 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;
> @@ -862,8 +862,12 @@ 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;
> +		goto drop;


This goto is kind of meaningless.

Thanks


>   	}
> +
> +drop:
> +	put_xdp_frags(xdp);
> +	return VIRTNET_XDP_RES_DROP;
>   }
>   
>   static unsigned int virtnet_get_headroom(struct virtnet_info *vi)
> @@ -1199,7 +1203,7 @@ 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;
> @@ -1218,7 +1222,7 @@ 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++];
> @@ -1233,6 +1237,10 @@ 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,
> @@ -1361,7 +1369,7 @@ 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);
>   
> @@ -1369,7 +1377,7 @@ 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;
> @@ -1379,11 +1387,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
>   			goto xdp_xmit;
>   
>   		case VIRTNET_XDP_RES_DROP:
> -			goto err_xdp_frags;
> +			goto err_xdp;
>   		}
> -err_xdp_frags:
> -		put_xdp_frags(&xdp);
> -		goto err_xdp;
>   	}
>   	rcu_read_unlock();
>