net: Move main gso loop out of dev_hard_start_xmit() into helper.

There is a slight policy change happening here as well.

The previous code would drop the entire rest of the GSO skb if any of
them got, for example, a congestion notification.

That makes no sense, anything NET_XMIT_MASK and below is something
like congestion or policing.  And in the congestion case it doesn't
even mean the packet was actually dropped.

Just continue until dev_xmit_complete() evaluates to false.

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/dev.c b/net/core/dev.c
index 0fde7d2..ab7bb80 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2616,6 +2616,34 @@ static int xmit_one(struct sk_buff *skb, struct net_device *dev,
        return rc;
 }
 
+static struct sk_buff *xmit_list(struct sk_buff *first, struct net_device *dev,
+                                struct netdev_queue *txq, int *ret)
+{
+       struct sk_buff *skb = first;
+       int rc = NETDEV_TX_OK;
+
+       while (skb) {
+               struct sk_buff *next = skb->next;
+
+               skb->next = NULL;
+               rc = xmit_one(skb, dev, txq);
+               if (unlikely(!dev_xmit_complete(rc))) {
+                       skb->next = next;
+                       goto out;
+               }
+
+               skb = next;
+               if (netif_xmit_stopped(txq) && skb) {
+                       rc = NETDEV_TX_BUSY;
+                       break;
+               }
+       }
+
+out:
+       *ret = rc;
+       return skb;
+}
+
 int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
                        struct netdev_queue *txq)
 {
@@ -2681,25 +2709,7 @@ int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
        }
 
 gso:
-       do {
-               struct sk_buff *nskb = skb->next;
-
-               skb->next = nskb->next;
-               nskb->next = NULL;
-
-               rc = xmit_one(nskb, dev, txq);
-               if (unlikely(rc != NETDEV_TX_OK)) {
-                       if (rc & ~NETDEV_TX_MASK)
-                               goto out_kfree_gso_skb;
-                       nskb->next = skb->next;
-                       skb->next = nskb;
-                       return rc;
-               }
-               if (unlikely(netif_xmit_stopped(txq) && skb->next))
-                       return NETDEV_TX_BUSY;
-       } while (skb->next);
-
-out_kfree_gso_skb:
+       skb->next = xmit_list(skb->next, dev, txq, &rc);
        if (likely(skb->next == NULL)) {
                skb->destructor = DEV_GSO_CB(skb)->destructor;
                consume_skb(skb);