1 files changed, 33 insertions, 29 deletions

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 7d50711476fe..3f44b522b831 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -810,23 +810,17 @@ static inline struct sk_buff *xenvif_alloc_skb(unsigned int size)
 static struct gnttab_map_grant_ref *xenvif_get_requests(struct xenvif_queue *queue,
 							struct sk_buff *skb,
 							struct xen_netif_tx_request *txp,
-							struct gnttab_map_grant_ref *gop)
+							struct gnttab_map_grant_ref *gop,
+							unsigned int frag_overflow,
+							struct sk_buff *nskb)
 {
 	struct skb_shared_info *shinfo = skb_shinfo(skb);
 	skb_frag_t *frags = shinfo->frags;
 	u16 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
 	int start;
 	pending_ring_idx_t index;
-	unsigned int nr_slots, frag_overflow = 0;
+	unsigned int nr_slots;
 
-	/* At this point shinfo->nr_frags is in fact the number of
-	 * slots, which can be as large as XEN_NETBK_LEGACY_SLOTS_MAX.
-	 */
-	if (shinfo->nr_frags > MAX_SKB_FRAGS) {
-		frag_overflow = shinfo->nr_frags - MAX_SKB_FRAGS;
-		BUG_ON(frag_overflow > MAX_SKB_FRAGS);
-		shinfo->nr_frags = MAX_SKB_FRAGS;
-	}
 	nr_slots = shinfo->nr_frags;
 
 	/* Skip first skb fragment if it is on same page as header fragment. */
@@ -841,13 +835,6 @@ static struct gnttab_map_grant_ref *xenvif_get_requests(struct xenvif_queue *que
 	}
 
 	if (frag_overflow) {
-		struct sk_buff *nskb = xenvif_alloc_skb(0);
-		if (unlikely(nskb == NULL)) {
-			if (net_ratelimit())
-				netdev_err(queue->vif->dev,
-					   "Can't allocate the frag_list skb.\n");
-			return NULL;
-		}
 
 		shinfo = skb_shinfo(nskb);
 		frags = shinfo->frags;
@@ -1175,9 +1162,10 @@ static void xenvif_tx_build_gops(struct xenvif_queue *queue,
 				     unsigned *copy_ops,
 				     unsigned *map_ops)
 {
-	struct gnttab_map_grant_ref *gop = queue->tx_map_ops, *request_gop;
-	struct sk_buff *skb;
+	struct gnttab_map_grant_ref *gop = queue->tx_map_ops;
+	struct sk_buff *skb, *nskb;
 	int ret;
+	unsigned int frag_overflow;
 
 	while (skb_queue_len(&queue->tx_queue) < budget) {
 		struct xen_netif_tx_request txreq;
@@ -1265,6 +1253,29 @@ static void xenvif_tx_build_gops(struct xenvif_queue *queue,
 			break;
 		}
 
+		skb_shinfo(skb)->nr_frags = ret;
+		if (data_len < txreq.size)
+			skb_shinfo(skb)->nr_frags++;
+		/* At this point shinfo->nr_frags is in fact the number of
+		 * slots, which can be as large as XEN_NETBK_LEGACY_SLOTS_MAX.
+		 */
+		frag_overflow = 0;
+		nskb = NULL;
+		if (skb_shinfo(skb)->nr_frags > MAX_SKB_FRAGS) {
+			frag_overflow = skb_shinfo(skb)->nr_frags - MAX_SKB_FRAGS;
+			BUG_ON(frag_overflow > MAX_SKB_FRAGS);
+			skb_shinfo(skb)->nr_frags = MAX_SKB_FRAGS;
+			nskb = xenvif_alloc_skb(0);
+			if (unlikely(nskb == NULL)) {
+				kfree_skb(skb);
+				xenvif_tx_err(queue, &txreq, idx);
+				if (net_ratelimit())
+					netdev_err(queue->vif->dev,
+						   "Can't allocate the frag_list skb.\n");
+				break;
+			}
+		}
+
 		if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
 			struct xen_netif_extra_info *gso;
 			gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
@@ -1272,6 +1283,7 @@ static void xenvif_tx_build_gops(struct xenvif_queue *queue,
 			if (xenvif_set_skb_gso(queue->vif, skb, gso)) {
 				/* Failure in xenvif_set_skb_gso is fatal. */
 				kfree_skb(skb);
+				kfree_skb(nskb);
 				break;
 			}
 		}
@@ -1294,9 +1306,7 @@ static void xenvif_tx_build_gops(struct xenvif_queue *queue,
 
 		(*copy_ops)++;
 
-		skb_shinfo(skb)->nr_frags = ret;
 		if (data_len < txreq.size) {
-			skb_shinfo(skb)->nr_frags++;
 			frag_set_pending_idx(&skb_shinfo(skb)->frags[0],
 					     pending_idx);
 			xenvif_tx_create_map_op(queue, pending_idx, &txreq, gop);
@@ -1310,13 +1320,8 @@ static void xenvif_tx_build_gops(struct xenvif_queue *queue,
 
 		queue->pending_cons++;
 
-		request_gop = xenvif_get_requests(queue, skb, txfrags, gop);
-		if (request_gop == NULL) {
-			kfree_skb(skb);
-			xenvif_tx_err(queue, &txreq, idx);
-			break;
-		}
-		gop = request_gop;
+		gop = xenvif_get_requests(queue, skb, txfrags, gop,
+				          frag_overflow, nskb);
 
 		__skb_queue_tail(&queue->tx_queue, skb);
 
@@ -1536,7 +1541,6 @@ void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success)
 		smp_wmb();
 		queue->dealloc_prod++;
 	} while (ubuf);
-	wake_up(&queue->dealloc_wq);
 	spin_unlock_irqrestore(&queue->callback_lock, flags);
 
 	if (likely(zerocopy_success))