[PATCH 19/40] Staging: hv: netvsc: Get rid of release_outbound_net_device() by inlining the code

@@ -100,27 +100,6 @@ static void put_net_device(struct hv_device *device)
 	spin_unlock_irqrestore(&device->ext_lock, flags);
 }
 
-static struct netvsc_device *release_outbound_net_device(
-		struct hv_device *device)
-{
-	struct netvsc_device *net_device;
-	unsigned long flags;
-
-	spin_lock_irqsave(&device->ext_lock, flags);
-	net_device = device->ext;
-	if (net_device == NULL) {
-		spin_unlock_irqrestore(&device->ext_lock, flags);
-		return NULL;
-	}
-
-	/* Busy wait until the ref drop to 2, then set it to 1 */
-	while (atomic_cmpxchg(&net_device->refcnt, 2, 1) != 2)
-		udelay(100);
-
-	spin_unlock_irqrestore(&device->ext_lock, flags);
-	return net_device;
-}
-
 static struct netvsc_device *release_inbound_net_device(
 		struct hv_device *device)
 {

@@ -423,14 +402,15 @@ int netvsc_device_remove(struct hv_device *device)
 {
 	struct netvsc_device *net_device;
 	struct hv_netvsc_packet *netvsc_packet, *pos;
-	struct net_device *ndev = dev_get_drvdata(&device->device);
 
 	/* Stop outbound traffic ie sends and receives completions */
-	net_device = release_outbound_net_device(device);
-	if (!net_device) {
-		netdev_err(ndev, "No net device present!!\n");
-		return -ENODEV;
-	}
+
+	/*
+	 * Since we currently hold a reference on the net_device,
+	 * it is safe to dereference the ext pointer.
+	 */
+	net_device = (struct netvsc_device *)device->ext;
+	atomic_dec(&net_device->refcnt);
 	net_device->destroy = true;
 
 	/* Wait for all send completions */

@@ -1006,7 +986,6 @@ cleanup:
 			kfree(packet);
 		}
 
-		release_outbound_net_device(device);
 		release_inbound_net_device(device);
 
 		kfree(net_device);