virtio_net: make all RX paths handle erors consistently

receive mergeable now handles errors internally.
Do same for big and small packet paths, otherwise
the logic is too hard to follow.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 71a2eac7b0396dcdcab5882afb8868dbc35aa478..916241d16c6764c117f80fa7109bdbff7dfdb714 100644 (file)
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -299,6 +299,35 @@ static struct sk_buff *page_to_skb(struct receive_queue *rq,
        return skb;
 }
 
+static struct sk_buff *receive_small(void *buf, unsigned int len)
+{
+       struct sk_buff * skb = buf;
+
+       len -= sizeof(struct virtio_net_hdr);
+       skb_trim(skb, len);
+
+       return skb;
+}
+
+static struct sk_buff *receive_big(struct net_device *dev,
+                                  struct receive_queue *rq,
+                                  void *buf,
+                                  unsigned int len)
+{
+       struct page *page = buf;
+       struct sk_buff *skb = page_to_skb(rq, page, 0, len, PAGE_SIZE);
+
+       if (unlikely(!skb))
+               goto err;
+
+       return skb;
+
+err:
+       dev->stats.rx_dropped++;
+       give_pages(rq, page);
+       return NULL;
+}
+
 static struct sk_buff *receive_mergeable(struct net_device *dev,
                                         struct receive_queue *rq,
                                         void *buf,
@@ -392,7 +421,6 @@ static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
        struct net_device *dev = vi->dev;
        struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
        struct sk_buff *skb;
-       struct page *page;
        struct skb_vnet_hdr *hdr;
 
        if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
@@ -407,23 +435,15 @@ static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
                return;
        }
 
-       if (!vi->mergeable_rx_bufs && !vi->big_packets) {
-               skb = buf;
-               len -= sizeof(struct virtio_net_hdr);
-               skb_trim(skb, len);
-       } else if (vi->mergeable_rx_bufs) {
+       if (vi->mergeable_rx_bufs)
                skb = receive_mergeable(dev, rq, buf, len);
-               if (unlikely(!skb))
-                       return;
-       } else {
-               page = buf;
-               skb = page_to_skb(rq, page, 0, len, PAGE_SIZE);
-               if (unlikely(!skb)) {
-                       dev->stats.rx_dropped++;
-                       give_pages(rq, page);
-                       return;
-               }
-       }
+       else if (vi->big_packets)
+               skb = receive_big(dev, rq, buf, len);
+       else
+               skb = receive_small(buf, len);
+
+       if (unlikely(!skb))
+               return;
 
        hdr = skb_vnet_hdr(skb);