[PATCH stable 2/2] virtio-net: make all RX paths handle erors consistently
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2013-12-25 14:52:37
Also in:
lkml, netdev
Subsystem:
networking drivers, the rest, virtio net driver · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, "Michael S. Tsirkin", Jason Wang, Eugenio Pérez
receive mergeable now handles errors internally. Do same for big and small packet paths, otherwise the logic is too hard to follow. Cc: Jason Wang <redacted> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> (cherry picked from commit f121159d72091f25afb22007c833e60a6845e912) --- drivers/net/virtio_net.c | 56 +++++++++++++++++++++++++++++++----------------- 1 file changed, 36 insertions(+), 20 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 435076f..c0ed6d5 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c@@ -297,6 +297,34 @@ 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) +{ + struct page *page = buf; + struct sk_buff *skb = page_to_skb(rq, page, 0); + + 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,
@@ -360,7 +388,6 @@ 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)) {
@@ -372,26 +399,15 @@ static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len) dev_kfree_skb(buf); return; } + if (vi->mergeable_rx_bufs) + skb = receive_mergeable(dev, rq, buf, len); + else if (vi->big_packets) + skb = receive_big(dev, rq, buf); + else + skb = receive_small(buf, len); - if (!vi->mergeable_rx_bufs && !vi->big_packets) { - skb = buf; - len -= sizeof(struct virtio_net_hdr); - skb_trim(skb, len); - } else { - page = buf; - if (vi->mergeable_rx_bufs) { - skb = receive_mergeable(dev, rq, page, len); - if (unlikely(!skb)) - return; - } else { - skb = page_to_skb(rq, page, len); - if (unlikely(!skb)) { - dev->stats.rx_dropped++; - give_pages(rq, page); - return; - } - } - } + if (unlikely(!skb)) + return; hdr = skb_vnet_hdr(skb);
--
MST