Re: [PATCH net v2] net: consume xmit errors of GSO frames

--- a/net/core/dev.c
+++ b/net/core/dev.c

@@ -4822,6 +4822,8 @@ int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
 		 * to -1 or to their cpu id, but not to our id.
 		 */
 		if (READ_ONCE(txq->xmit_lock_owner) != cpu) {
+			bool is_list = false;
+
 			if (dev_xmit_recursion())
 				goto recursion_alert;
 

@@ -4832,17 +4834,28 @@ int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
 			HARD_TX_LOCK(dev, txq, cpu);
 
 			if (!netif_xmit_stopped(txq)) {
+				is_list = !!skb->next;
+
 				dev_xmit_recursion_inc();
 				skb = dev_hard_start_xmit(skb, dev, txq, &rc);
 				dev_xmit_recursion_dec();
-				if (dev_xmit_complete(rc)) {
-					HARD_TX_UNLOCK(dev, txq);
-					goto out;
-				}
+
+				/* GSO segments a single SKB into
+				 * a list of frames. TCP expects error
+				 * to mean none of the data was sent.
+				 */
+				if (is_list)
+					rc = NETDEV_TX_OK;
 			}
 			HARD_TX_UNLOCK(dev, txq);
+			if (!skb) /* xmit completed */
+				goto out;
+
 			net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
 					     dev->name);
+			/* NETDEV_TX_BUSY or queue was stopped */
+			if (!is_list)
+				rc = -ENETDOWN;
 		} else {
 			/* Recursion is detected! It is possible,
 			 * unfortunately

@@ -4850,10 +4863,10 @@ int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
 recursion_alert:
 			net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
 					     dev->name);
+			rc = -ENETDOWN;
 		}
 	}
 
-	rc = -ENETDOWN;