Merge branch 'master' of git://1984.lsi.us.es/nf-next

[~andy/linux] / drivers / net / veth.c

diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index c048f8d27bbf7e43a6ecd0148d1803cdb1515429..07a4af0aa3dcda800a9527e3ba01d9f65ea3feec 100644 (file)
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -32,7 +32,7 @@ struct pcpu_vstats {
 };
 
 struct veth_priv {
-       struct net_device       *peer;
+       struct net_device __rcu *peer;
        atomic64_t              dropped;
 };
 
@@ -89,10 +89,10 @@ static int veth_get_sset_count(struct net_device *dev, int sset)
 static void veth_get_ethtool_stats(struct net_device *dev,
                struct ethtool_stats *stats, u64 *data)
 {
-       struct veth_priv *priv;
+       struct veth_priv *priv = netdev_priv(dev);
+       struct net_device *peer = rtnl_dereference(priv->peer);
 
-       priv = netdev_priv(dev);
-       data[0] = priv->peer->ifindex;
+       data[0] = peer ? peer->ifindex : 0;
 }
 
 static const struct ethtool_ops veth_ethtool_ops = {
@@ -107,9 +107,15 @@ static const struct ethtool_ops veth_ethtool_ops = {
 static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
 {
        struct veth_priv *priv = netdev_priv(dev);
-       struct net_device *rcv = priv->peer;
+       struct net_device *rcv;
        int length = skb->len;
 
+       rcu_read_lock();
+       rcv = rcu_dereference(priv->peer);
+       if (unlikely(!rcv)) {
+               kfree_skb(skb);
+               goto drop;
+       }
        /* don't change ip_summed == CHECKSUM_PARTIAL, as that
         * will cause bad checksum on forwarded packets
         */
@@ -125,9 +131,10 @@ static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
                stats->packets++;
                u64_stats_update_end(&stats->syncp);
        } else {
+drop:
                atomic64_inc(&priv->dropped);
        }
-
+       rcu_read_unlock();
        return NETDEV_TX_OK;
 }
 
@@ -162,30 +169,36 @@ static struct rtnl_link_stats64 *veth_get_stats64(struct net_device *dev,
                                                  struct rtnl_link_stats64 *tot)
 {
        struct veth_priv *priv = netdev_priv(dev);
+       struct net_device *peer;
        struct pcpu_vstats one;
 
        tot->tx_dropped = veth_stats_one(&one, dev);
        tot->tx_bytes = one.bytes;
        tot->tx_packets = one.packets;
 
-       tot->rx_dropped = veth_stats_one(&one, priv->peer);
-       tot->rx_bytes = one.bytes;
-       tot->rx_packets = one.packets;
+       rcu_read_lock();
+       peer = rcu_dereference(priv->peer);
+       if (peer) {
+               tot->rx_dropped = veth_stats_one(&one, peer);
+               tot->rx_bytes = one.bytes;
+               tot->rx_packets = one.packets;
+       }
+       rcu_read_unlock();
 
        return tot;
 }
 
 static int veth_open(struct net_device *dev)
 {
-       struct veth_priv *priv;
+       struct veth_priv *priv = netdev_priv(dev);
+       struct net_device *peer = rtnl_dereference(priv->peer);
 
-       priv = netdev_priv(dev);
-       if (priv->peer == NULL)
+       if (!peer)
                return -ENOTCONN;
 
-       if (priv->peer->flags & IFF_UP) {
+       if (peer->flags & IFF_UP) {
                netif_carrier_on(dev);
-               netif_carrier_on(priv->peer);
+               netif_carrier_on(peer);
        }
        return 0;
 }
@@ -193,9 +206,11 @@ static int veth_open(struct net_device *dev)
 static int veth_close(struct net_device *dev)
 {
        struct veth_priv *priv = netdev_priv(dev);
+       struct net_device *peer = rtnl_dereference(priv->peer);
 
        netif_carrier_off(dev);
-       netif_carrier_off(priv->peer);
+       if (peer)
+               netif_carrier_off(peer);
 
        return 0;
 }
@@ -238,6 +253,10 @@ static const struct net_device_ops veth_netdev_ops = {
        .ndo_set_mac_address = eth_mac_addr,
 };
 
+#define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_ALL_TSO |    \
+                      NETIF_F_HW_CSUM | NETIF_F_RXCSUM | NETIF_F_HIGHDMA | \
+                      NETIF_F_HW_VLAN_TX | NETIF_F_HW_VLAN_RX)
+
 static void veth_setup(struct net_device *dev)
 {
        ether_setup(dev);
@@ -248,9 +267,10 @@ static void veth_setup(struct net_device *dev)
        dev->netdev_ops = &veth_netdev_ops;
        dev->ethtool_ops = &veth_ethtool_ops;
        dev->features |= NETIF_F_LLTX;
+       dev->features |= VETH_FEATURES;
        dev->destructor = veth_dev_free;
 
-       dev->hw_features = NETIF_F_HW_CSUM | NETIF_F_SG | NETIF_F_RXCSUM;
+       dev->hw_features = VETH_FEATURES;
 }
 
 /*
@@ -375,10 +395,10 @@ static int veth_newlink(struct net *src_net, struct net_device *dev,
         */
 
        priv = netdev_priv(dev);
-       priv->peer = peer;
+       rcu_assign_pointer(priv->peer, peer);
 
        priv = netdev_priv(peer);
-       priv->peer = dev;
+       rcu_assign_pointer(priv->peer, dev);
        return 0;
 
 err_register_dev:
@@ -399,10 +419,20 @@ static void veth_dellink(struct net_device *dev, struct list_head *head)
        struct net_device *peer;
 
        priv = netdev_priv(dev);
-       peer = priv->peer;
+       peer = rtnl_dereference(priv->peer);
 
+       /* Note : dellink() is called from default_device_exit_batch(),
+        * before a rcu_synchronize() point. The devices are guaranteed
+        * not being freed before one RCU grace period.
+        */
+       RCU_INIT_POINTER(priv->peer, NULL);
        unregister_netdevice_queue(dev, head);
-       unregister_netdevice_queue(peer, head);
+
+       if (peer) {
+               priv = netdev_priv(peer);
+               RCU_INIT_POINTER(priv->peer, NULL);
+               unregister_netdevice_queue(peer, head);
+       }
 }
 
 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {