On Tue, 25 Apr 2023 15:41:28 +0800, Jason Wang <jasowang@xxxxxxxxxx> wrote:
> On Sun, Apr 23, 2023 at 6:57 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.
>
> Thinking of this, I think releasing frags in
> virtnet_build_xdp_buff_mrg() is fine. But for virtnet_xdp_handler(),
> it's better to be done by the caller, since the frags were prepared by
> the caller anyhow.
I agree this.
Thanks.
>
> Thanks
>
> >
> > 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 5f37a1cef61e..c6bf425e8844 100644
> > --- a/drivers/net/virtio_net.c
> > +++ b/drivers/net/virtio_net.c
> > @@ -825,7 +825,7 @@ 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 XDP_DROP;
> > + goto drop;
> > }
> >
> > err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
> > @@ -833,7 +833,7 @@ 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 XDP_DROP;
> > + goto drop;
> > }
> > *xdp_xmit |= VIRTIO_XDP_TX;
> > return act;
> > @@ -842,7 +842,7 @@ 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 XDP_DROP;
> > + goto drop;
> >
> > *xdp_xmit |= VIRTIO_XDP_REDIR;
> > return act;
> > @@ -854,8 +854,12 @@ 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 XDP_DROP;
> > + break;
> > }
> > +
> > +drop:
> > + put_xdp_frags(xdp);
> > + return XDP_DROP;
> > }
> >
> > static unsigned int virtnet_get_headroom(struct virtnet_info *vi)
> > @@ -1190,7 +1194,7 @@ 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;
> > @@ -1209,7 +1213,7 @@ 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++];
> > @@ -1224,6 +1228,10 @@ 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_get_buf(struct virtnet_info *vi,
> > @@ -1353,7 +1361,7 @@ 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);
> >
> > @@ -1361,7 +1369,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
> > case XDP_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;
> > @@ -1370,11 +1378,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
> > rcu_read_unlock();
> > goto xdp_xmit;
> > default:
> > - break;
> > + goto err_xdp;
> > }
> > -err_xdp_frags:
> > - put_xdp_frags(&xdp);
> > - goto err_xdp;
> > }
> > rcu_read_unlock();
> >
> > --
> > 2.32.0.3.g01195cf9f
> >
>
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