vlan: multiqueue vlan device

vlan devices are currently not multi-queue capable.

We can do that with a new rtnl_link_ops method,
get_tx_queues(), called from rtnl_create_link()

This new method gets num_tx_queues/real_num_tx_queues
from real device.

register_vlan_device() is also handled.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/8021q/vlan.c

@@ -330,12 +330,13 @@ static int register_vlan_device(struct net_device *real_dev, u16 vlan_id)
 		snprintf(name, IFNAMSIZ, "vlan%.4i", vlan_id);
 	}
 
-	new_dev = alloc_netdev(sizeof(struct vlan_dev_info), name,
-			       vlan_setup);
+	new_dev = alloc_netdev_mq(sizeof(struct vlan_dev_info), name,
+				  vlan_setup, real_dev->num_tx_queues);
 
 	if (new_dev == NULL)
 		return -ENOBUFS;
 
+	new_dev->real_num_tx_queues = real_dev->real_num_tx_queues;
 	dev_net_set(new_dev, net);
 	/* need 4 bytes for extra VLAN header info,
 	 * hope the underlying device can handle it.