Merge branch 'xen-netback'

David Vrabel says:

====================
xen-netback: fix ethtool stats and memory leak

A couple of bug fixes for netback:
- make ethool stats to report the correct values.
- don't leak 1 MiB every time a VIF is destroyed.

Changes in v2:
- Split 2nd patch into leak fix and refactor patches
====================
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/xen-netback/interface.c

@@ -340,12 +340,11 @@ static void xenvif_get_ethtool_stats(struct net_device *dev,
 	unsigned int num_queues = vif->num_queues;
 	int i;
 	unsigned int queue_index;
-	struct xenvif_stats *vif_stats;
 
 	for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++) {
 		unsigned long accum = 0;
 		for (queue_index = 0; queue_index < num_queues; ++queue_index) {
-			vif_stats = &vif->queues[queue_index].stats;
+			void *vif_stats = &vif->queues[queue_index].stats;
 			accum += *(unsigned long *)(vif_stats + xenvif_stats[i].offset);
 		}
 		data[i] = accum;

drivers/net/xen-netback/netback.c

@@ -1349,7 +1349,7 @@ static int xenvif_handle_frag_list(struct xenvif_queue *queue, struct sk_buff *s
 {
 	unsigned int offset = skb_headlen(skb);
 	skb_frag_t frags[MAX_SKB_FRAGS];
-	int i;
+	int i, f;
 	struct ubuf_info *uarg;
 	struct sk_buff *nskb = skb_shinfo(skb)->frag_list;
 
@@ -1389,23 +1389,25 @@ static int xenvif_handle_frag_list(struct xenvif_queue *queue, struct sk_buff *s
 		frags[i].page_offset = 0;
 		skb_frag_size_set(&frags[i], len);
 	}
-	/* swap out with old one */
-	memcpy(skb_shinfo(skb)->frags,
-	       frags,
-	       i * sizeof(skb_frag_t));
-	skb_shinfo(skb)->nr_frags = i;
-	skb->truesize += i * PAGE_SIZE;
 
-	/* remove traces of mapped pages and frag_list */
+	/* Copied all the bits from the frag list -- free it. */
 	skb_frag_list_init(skb);
+	xenvif_skb_zerocopy_prepare(queue, nskb);
+	kfree_skb(nskb);
+
+	/* Release all the original (foreign) frags. */
+	for (f = 0; f < skb_shinfo(skb)->nr_frags; f++)
+		skb_frag_unref(skb, f);
 	uarg = skb_shinfo(skb)->destructor_arg;
 	/* increase inflight counter to offset decrement in callback */
 	atomic_inc(&queue->inflight_packets);
 	uarg->callback(uarg, true);
 	skb_shinfo(skb)->destructor_arg = NULL;
 
-	xenvif_skb_zerocopy_prepare(queue, nskb);
-	kfree_skb(nskb);
+	/* Fill the skb with the new (local) frags. */
+	memcpy(skb_shinfo(skb)->frags, frags, i * sizeof(skb_frag_t));
+	skb_shinfo(skb)->nr_frags = i;
+	skb->truesize += i * PAGE_SIZE;
 
 	return 0;
 }