1 files changed, 19 insertions, 29 deletions

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 68d64f0313ea..a6fcf15adc4f 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -130,7 +130,6 @@ struct skb_vnet_hdr {
                 struct virtio_net_hdr hdr;
                 struct virtio_net_hdr_mrg_rxbuf mhdr;
         };
-        unsigned int num_sg;
 };
 
 struct padded_vnet_hdr {
@@ -530,10 +529,10 @@ static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp)
                         err = add_recvbuf_small(rq, gfp);
 
                 oom = err == -ENOMEM;
-                if (err < 0)
+                if (err)
                         break;
                 ++rq->num;
-        } while (err > 0);
+        } while (rq->vq->num_free);
         if (unlikely(rq->num > rq->max))
                 rq->max = rq->num;
         virtqueue_kick(rq->vq);
@@ -640,10 +639,10 @@ static int virtnet_open(struct net_device *dev)
         return 0;
 }
 
-static unsigned int free_old_xmit_skbs(struct send_queue *sq)
+static void free_old_xmit_skbs(struct send_queue *sq)
 {
         struct sk_buff *skb;
-        unsigned int len, tot_sgs = 0;
+        unsigned int len;
         struct virtnet_info *vi = sq->vq->vdev->priv;
         struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
 
@@ -655,10 +654,8 @@ static unsigned int free_old_xmit_skbs(struct send_queue *sq)
                 stats->tx_packets++;
                 u64_stats_update_end(&stats->tx_syncp);
 
-                tot_sgs += skb_vnet_hdr(skb)->num_sg;
                 dev_kfree_skb_any(skb);
         }
-        return tot_sgs;
 }
 
 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
@@ -666,6 +663,7 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
         struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
         const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
         struct virtnet_info *vi = sq->vq->vdev->priv;
+        unsigned num_sg;
 
         pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
 
@@ -704,8 +702,8 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
         else
                 sg_set_buf(sq->sg, &hdr->hdr, sizeof hdr->hdr);
 
-        hdr->num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
-        return virtqueue_add_buf(sq->vq, sq->sg, hdr->num_sg,
+        num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
+        return virtqueue_add_buf(sq->vq, sq->sg, num_sg,
                                  0, skb, GFP_ATOMIC);
 }
 
@@ -714,28 +712,20 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
         struct virtnet_info *vi = netdev_priv(dev);
         int qnum = skb_get_queue_mapping(skb);
         struct send_queue *sq = &vi->sq[qnum];
-        int capacity;
+        int err;
 
         /* Free up any pending old buffers before queueing new ones. */
         free_old_xmit_skbs(sq);
 
         /* Try to transmit */
-        capacity = xmit_skb(sq, skb);
-
-        /* This can happen with OOM and indirect buffers. */
-        if (unlikely(capacity < 0)) {
-                if (likely(capacity == -ENOMEM)) {
-                        if (net_ratelimit())
-                                dev_warn(&dev->dev,
-                                         "TXQ (%d) failure: out of memory\n",
-                                         qnum);
-                } else {
-                        dev->stats.tx_fifo_errors++;
-                        if (net_ratelimit())
-                                dev_warn(&dev->dev,
-                                         "Unexpected TXQ (%d) failure: %d\n",
-                                         qnum, capacity);
-                }
+        err = xmit_skb(sq, skb);
+
+        /* This should not happen! */
+        if (unlikely(err)) {
+                dev->stats.tx_fifo_errors++;
+                if (net_ratelimit())
+                        dev_warn(&dev->dev,
+                                 "Unexpected TXQ (%d) queue failure: %d\n", qnum, err);
                 dev->stats.tx_dropped++;
                 kfree_skb(skb);
                 return NETDEV_TX_OK;
@@ -748,12 +738,12 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
 
         /* Apparently nice girls don't return TX_BUSY; stop the queue
          * before it gets out of hand.  Naturally, this wastes entries. */
-        if (capacity < 2+MAX_SKB_FRAGS) {
+        if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
                 netif_stop_subqueue(dev, qnum);
                 if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
                         /* More just got used, free them then recheck. */
-                        capacity += free_old_xmit_skbs(sq);
-                        if (capacity >= 2+MAX_SKB_FRAGS) {
+                        free_old_xmit_skbs(sq);
+                        if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
                                 netif_start_subqueue(dev, qnum);
                                 virtqueue_disable_cb(sq->vq);
                         }