virtio: fix scatterlist sizing in net driver.

Herbert Xu points out (within another patch) that my scatterlists are
too short: one entry for the gso header, one for the skb->data, and
MAX_SKB_FRAGS for all the fragments.

Fix both xmit and recv sides (recv currently unused, coming in later
patch).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 1fd43e461ba572d750712b00cf5a37ccc1a44998..fc7eeaa1f1b627e9eb4bbe1594116a4e172f6a32 100644 (file)
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -142,10 +142,10 @@ drop:
 static void try_fill_recv(struct virtnet_info *vi)
 {
        struct sk_buff *skb;
-       struct scatterlist sg[1+MAX_SKB_FRAGS];
+       struct scatterlist sg[2+MAX_SKB_FRAGS];
        int num, err;
 
-       sg_init_table(sg, 1+MAX_SKB_FRAGS);
+       sg_init_table(sg, 2+MAX_SKB_FRAGS);
        for (;;) {
                skb = netdev_alloc_skb(vi->dev, MAX_PACKET_LEN);
                if (unlikely(!skb))
@@ -231,11 +231,11 @@ static int start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
        struct virtnet_info *vi = netdev_priv(dev);
        int num, err;
-       struct scatterlist sg[1+MAX_SKB_FRAGS];
+       struct scatterlist sg[2+MAX_SKB_FRAGS];
        struct virtio_net_hdr *hdr;
        const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
 
-       sg_init_table(sg, 1+MAX_SKB_FRAGS);
+       sg_init_table(sg, 2+MAX_SKB_FRAGS);
 
        pr_debug("%s: xmit %p " MAC_FMT "\n", dev->name, skb,
                 dest[0], dest[1], dest[2],