Properly synchronize dp_dev destruction.

Before, we didn't really synchronize this at all.  Now, when we want
to destroy the ofX device, we stop the transmit path and wait for
in-progress transmissions to finish.

diff --git a/datapath/dp_dev.c b/datapath/dp_dev.c
index e618d71..02468eb 100644 (file)
--- a/datapath/dp_dev.c
+++ b/datapath/dp_dev.c
@@ -55,19 +55,16 @@ static int dp_dev_mac_addr(struct net_device *dev, void *p)
 static int dp_dev_xmit(struct sk_buff *skb, struct net_device *netdev)
 {
        struct dp_dev *dp_dev = dp_dev_priv(netdev);
-       struct datapath *dp;
+       struct datapath *dp = dp_dev->dp;
+
+       dp_dev->stats.tx_packets++;
+       dp_dev->stats.tx_bytes += skb->len;
+
+       skb_reset_mac_header(skb);
        rcu_read_lock();
-       dp = dp_dev->dp;
-       if (likely(dp != NULL)) {
-               dp_dev->stats.tx_packets++;
-               dp_dev->stats.tx_bytes += skb->len;
-               skb_reset_mac_header(skb);
-               fwd_port_input(dp->chain, skb, OFPP_LOCAL);
-       } else {
-               dp_dev->stats.tx_dropped++;
-               kfree_skb(skb);
-       }
+       fwd_port_input(dp->chain, skb, OFPP_LOCAL);
        rcu_read_unlock();
+
        return 0;
 }
 
@@ -127,8 +124,7 @@ int dp_dev_setup(struct datapath *dp)
 
 void dp_dev_destroy(struct datapath *dp)
 {
-       struct dp_dev *dp_dev = dp_dev_priv(dp->netdev);
-       dp_dev->dp = NULL;
+       netif_tx_disable(dp->netdev);
        synchronize_net();
        unregister_netdev(dp->netdev);
        free_netdev(dp->netdev);