1 files changed, 59 insertions, 30 deletions

diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index 89eec6fead75..7d4c0c46a889 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -62,6 +62,8 @@ module_param_named(max_queues, xennet_max_queues, uint, 0644);
 MODULE_PARM_DESC(max_queues,
 		 "Maximum number of queues per virtual interface");
 
+#define XENNET_TIMEOUT  (5 * HZ)
+
 static const struct ethtool_ops xennet_ethtool_ops;
 
 struct netfront_cb {
@@ -283,6 +285,7 @@ static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
 {
 	RING_IDX req_prod = queue->rx.req_prod_pvt;
 	int notify;
+	int err = 0;
 
 	if (unlikely(!netif_carrier_ok(queue->info->netdev)))
 		return;
@@ -297,8 +300,10 @@ static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
 		struct xen_netif_rx_request *req;
 
 		skb = xennet_alloc_one_rx_buffer(queue);
-		if (!skb)
+		if (!skb) {
+			err = -ENOMEM;
 			break;
+		}
 
 		id = xennet_rxidx(req_prod);
 
@@ -322,8 +327,13 @@ static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
 
 	queue->rx.req_prod_pvt = req_prod;
 
-	/* Not enough requests? Try again later. */
-	if (req_prod - queue->rx.sring->req_prod < NET_RX_SLOTS_MIN) {
+	/* Try again later if there are not enough requests or skb allocation
+	 * failed.
+	 * Enough requests is quantified as the sum of newly created slots and
+	 * the unconsumed slots at the backend.
+	 */
+	if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN ||
+	    unlikely(err)) {
 		mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
 		return;
 	}
@@ -1341,12 +1351,15 @@ static struct net_device *xennet_create_dev(struct xenbus_device *dev)
 
 	netif_carrier_off(netdev);
 
-	xenbus_switch_state(dev, XenbusStateInitialising);
-	wait_event(module_wq,
-		   xenbus_read_driver_state(dev->otherend) !=
-		   XenbusStateClosed &&
-		   xenbus_read_driver_state(dev->otherend) !=
-		   XenbusStateUnknown);
+	do {
+		xenbus_switch_state(dev, XenbusStateInitialising);
+		err = wait_event_timeout(module_wq,
+				 xenbus_read_driver_state(dev->otherend) !=
+				 XenbusStateClosed &&
+				 xenbus_read_driver_state(dev->otherend) !=
+				 XenbusStateUnknown, XENNET_TIMEOUT);
+	} while (!err);
+
 	return netdev;
 
  exit:
@@ -1835,7 +1848,7 @@ static int talk_to_netback(struct xenbus_device *dev,
 	err = xen_net_read_mac(dev, info->netdev->dev_addr);
 	if (err) {
 		xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
-		goto out;
+		goto out_unlocked;
 	}
 
 	rtnl_lock();
@@ -1950,6 +1963,7 @@ abort_transaction_no_dev_fatal:
 	xennet_destroy_queues(info);
  out:
 	rtnl_unlock();
+out_unlocked:
 	device_unregister(&dev->dev);
 	return err;
 }
@@ -1981,10 +1995,6 @@ static int xennet_connect(struct net_device *dev)
 	/* talk_to_netback() sets the correct number of queues */
 	num_queues = dev->real_num_tx_queues;
 
-	rtnl_lock();
-	netdev_update_features(dev);
-	rtnl_unlock();
-
 	if (dev->reg_state == NETREG_UNINITIALIZED) {
 		err = register_netdev(dev);
 		if (err) {
@@ -1994,6 +2004,10 @@ static int xennet_connect(struct net_device *dev)
 		}
 	}
 
+	rtnl_lock();
+	netdev_update_features(dev);
+	rtnl_unlock();
+
 	/*
 	 * All public and private state should now be sane.  Get
 	 * ready to start sending and receiving packets and give the driver
@@ -2157,28 +2171,43 @@ static const struct attribute_group xennet_dev_group = {
 };
 #endif /* CONFIG_SYSFS */
 
-static int xennet_remove(struct xenbus_device *dev)
+static void xennet_bus_close(struct xenbus_device *dev)
 {
-	struct netfront_info *info = dev_get_drvdata(&dev->dev);
-
-	dev_dbg(&dev->dev, "%s\n", dev->nodename);
+	int ret;
 
-	if (xenbus_read_driver_state(dev->otherend) != XenbusStateClosed) {
+	if (xenbus_read_driver_state(dev->otherend) == XenbusStateClosed)
+		return;
+	do {
 		xenbus_switch_state(dev, XenbusStateClosing);
-		wait_event(module_wq,
-			   xenbus_read_driver_state(dev->otherend) ==
-			   XenbusStateClosing ||
-			   xenbus_read_driver_state(dev->otherend) ==
-			   XenbusStateUnknown);
+		ret = wait_event_timeout(module_wq,
+				   xenbus_read_driver_state(dev->otherend) ==
+				   XenbusStateClosing ||
+				   xenbus_read_driver_state(dev->otherend) ==
+				   XenbusStateClosed ||
+				   xenbus_read_driver_state(dev->otherend) ==
+				   XenbusStateUnknown,
+				   XENNET_TIMEOUT);
+	} while (!ret);
+
+	if (xenbus_read_driver_state(dev->otherend) == XenbusStateClosed)
+		return;
 
+	do {
 		xenbus_switch_state(dev, XenbusStateClosed);
-		wait_event(module_wq,
-			   xenbus_read_driver_state(dev->otherend) ==
-			   XenbusStateClosed ||
-			   xenbus_read_driver_state(dev->otherend) ==
-			   XenbusStateUnknown);
-	}
+		ret = wait_event_timeout(module_wq,
+				   xenbus_read_driver_state(dev->otherend) ==
+				   XenbusStateClosed ||
+				   xenbus_read_driver_state(dev->otherend) ==
+				   XenbusStateUnknown,
+				   XENNET_TIMEOUT);
+	} while (!ret);
+}
+
+static int xennet_remove(struct xenbus_device *dev)
+{
+	struct netfront_info *info = dev_get_drvdata(&dev->dev);
 
+	xennet_bus_close(dev);
 	xennet_disconnect_backend(info);
 
 	if (info->netdev->reg_state == NETREG_REGISTERED)