Staging: hv: handle skb allocation failure

Some fixes to receive handling:
  * Dieing with assertion failure when running out of memory is not ok
  * Use newer alloc function to get aligned skb
  * Dropped statistic is supposed to be incremented only by
    driver it was responsible for the drop.

Compile tested only.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Cc: Hank Janssen <hjanssen@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 12 insertions, 20 deletions

diff --git a/drivers/staging/hv/netvsc_drv.c b/drivers/staging/hv/netvsc_drv.c
index e87a7c205d8..51a56e2b43c 100644
--- a/drivers/staging/hv/netvsc_drv.c
+++ b/drivers/staging/hv/netvsc_drv.c
@@ -294,7 +294,6 @@ static int netvsc_recv_callback(struct hv_device *device_obj,
         struct net_device_context *net_device_ctx;
         struct sk_buff *skb;
         void *data;
-        int ret;
         int i;
         unsigned long flags;
 
@@ -308,12 +307,12 @@ static int netvsc_recv_callback(struct hv_device *device_obj,
 
         net_device_ctx = netdev_priv(net);
 
-        /* Allocate a skb - TODO preallocate this */
-        /* Pad 2-bytes to align IP header to 16 bytes */
-        skb = dev_alloc_skb(packet->TotalDataBufferLength + 2);
-        ASSERT(skb);
-        skb_reserve(skb, 2);
-        skb->dev = net;
+        /* Allocate a skb - TODO direct I/O to pages? */
+        skb = netdev_alloc_skb_ip_align(net, packet->TotalDataBufferLength);
+        if (unlikely(!skb)) {
+                ++net->stats.rx_dropped;
+                return 0;
+        }
 
         /* for kmap_atomic */
         local_irq_save(flags);
@@ -338,25 +337,18 @@ static int netvsc_recv_callback(struct hv_device *device_obj,
         local_irq_restore(flags);
 
         skb->protocol = eth_type_trans(skb, net);
-
         skb->ip_summed = CHECKSUM_NONE;
 
+        net->stats.rx_packets++;
+        net->stats.rx_bytes += skb->len;
+
         /*
          * Pass the skb back up. Network stack will deallocate the skb when it
-         * is done
+         * is done.
+         * TODO - use NAPI?
          */
-        ret = netif_rx(skb);
-
-        switch (ret) {
-        case NET_RX_DROP:
-                net->stats.rx_dropped++;
-                break;
-        default:
-                net->stats.rx_packets++;
-                net->stats.rx_bytes += skb->len;
-                break;
+        netif_rx(skb);
 
-        }
         DPRINT_DBG(NETVSC_DRV, "# of recvs %lu total size %lu",
                    net->stats.rx_packets, net->stats.rx_bytes);