virtio_net: small: avoid code duplication in xdp scenarios

Avoid the problem that some variables(headroom and so on) will repeat
the calculation when process xdp.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index abf4ddc..b26d907 100644 (file)
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1031,11 +1031,10 @@ static struct sk_buff *receive_small(struct net_device *dev,
        struct sk_buff *skb;
        struct bpf_prog *xdp_prog;
        unsigned int xdp_headroom = (unsigned long)ctx;
-       unsigned int header_offset = VIRTNET_RX_PAD + xdp_headroom;
-       unsigned int headroom = vi->hdr_len + header_offset;
-       unsigned int buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
-                             SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
        struct page *page = virt_to_head_page(buf);
+       unsigned int header_offset;
+       unsigned int headroom;
+       unsigned int buflen;
 
        len -= vi->hdr_len;
        stats->bytes += len;
@@ -1063,6 +1062,11 @@ static struct sk_buff *receive_small(struct net_device *dev,
        rcu_read_unlock();
 
 skip_xdp:
+       header_offset = VIRTNET_RX_PAD + xdp_headroom;
+       headroom = vi->hdr_len + header_offset;
+       buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
+               SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+
        skb = build_skb(buf, buflen);
        if (!skb)
                goto err;