Merge branch 'netdev_iflink_remove'

Nicolas Dichtel says:

====================
Remove iflink field from the net_device structure

The first goal of this series was to advertise the veth peer via the IFLA_LINK
attribute, but iflink was not ready for network namespaces.

The iflink of an interface should be set to its ifindex for a physical interface
and to another value (0 if not relevant) for a virtual interface.
This was not the case for some interfaces, like vxlan, bond, or bridge for
example.
There is also a risk, if the targeted interface moves to another netns, that the
ifindex changes without updating corresponding iflink fields (eg. vlan).

Moving the management of this property into virtual interface drivers allows to
better handle this last case because most of virtual interface drivers have a
pointer to the link netdevice.
Anyway, dev->iflink value was always a copy of some internal data of the virtual
interface driver, thus let's use these internal data directly.

So, this series removes the iflink field and let the drivers manage it.
Only the last patch was present in the v1, but I fully rework it.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

6 files changed, 40 insertions, 4 deletions

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index 58b5aa3b6f2d..657b89b1d291 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -842,6 +842,13 @@ static void ipoib_set_mcast_list(struct net_device *dev)
 	queue_work(ipoib_workqueue, &priv->restart_task);
 }
 
+static int ipoib_get_iflink(const struct net_device *dev)
+{
+	struct ipoib_dev_priv *priv = netdev_priv(dev);
+
+	return priv->parent->ifindex;
+}
+
 static u32 ipoib_addr_hash(struct ipoib_neigh_hash *htbl, u8 *daddr)
 {
 	/*
@@ -1341,6 +1348,7 @@ static const struct net_device_ops ipoib_netdev_ops = {
 	.ndo_start_xmit	 	 = ipoib_start_xmit,
 	.ndo_tx_timeout		 = ipoib_timeout,
 	.ndo_set_rx_mode	 = ipoib_set_mcast_list,
+	.ndo_get_iflink		 = ipoib_get_iflink,
 };
 
 void ipoib_setup(struct net_device *dev)
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_vlan.c b/drivers/infiniband/ulp/ipoib/ipoib_vlan.c
index 9fad7b5ac8b9..4dd1313056a4 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_vlan.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_vlan.c
@@ -102,7 +102,6 @@ int __ipoib_vlan_add(struct ipoib_dev_priv *ppriv, struct ipoib_dev_priv *priv,
 	}
 
 	priv->child_type  = type;
-	priv->dev->iflink = ppriv->dev->ifindex;
 	list_add_tail(&priv->list, &ppriv->child_intfs);
 
 	return 0;
diff --git a/drivers/net/ipvlan/ipvlan_core.c b/drivers/net/ipvlan/ipvlan_core.c
index 2a175006028b..131bde98188d 100644
--- a/drivers/net/ipvlan/ipvlan_core.c
+++ b/drivers/net/ipvlan/ipvlan_core.c
@@ -330,7 +330,7 @@ static int ipvlan_process_v4_outbound(struct sk_buff *skb)
 	struct rtable *rt;
 	int err, ret = NET_XMIT_DROP;
 	struct flowi4 fl4 = {
-		.flowi4_oif = dev->iflink,
+		.flowi4_oif = dev_get_iflink(dev),
 		.flowi4_tos = RT_TOS(ip4h->tos),
 		.flowi4_flags = FLOWI_FLAG_ANYSRC,
 		.daddr = ip4h->daddr,
diff --git a/drivers/net/ipvlan/ipvlan_main.c b/drivers/net/ipvlan/ipvlan_main.c
index 2950c3780230..1701ede2df89 100644
--- a/drivers/net/ipvlan/ipvlan_main.c
+++ b/drivers/net/ipvlan/ipvlan_main.c
@@ -114,7 +114,6 @@ static int ipvlan_init(struct net_device *dev)
 	dev->features = phy_dev->features & IPVLAN_FEATURES;
 	dev->features |= NETIF_F_LLTX;
 	dev->gso_max_size = phy_dev->gso_max_size;
-	dev->iflink = phy_dev->ifindex;
 	dev->hard_header_len = phy_dev->hard_header_len;
 
 	ipvlan_set_lockdep_class(dev);
@@ -305,6 +304,13 @@ static int ipvlan_vlan_rx_kill_vid(struct net_device *dev, __be16 proto,
 	return 0;
 }
 
+static int ipvlan_get_iflink(const struct net_device *dev)
+{
+	struct ipvl_dev *ipvlan = netdev_priv(dev);
+
+	return ipvlan->phy_dev->ifindex;
+}
+
 static const struct net_device_ops ipvlan_netdev_ops = {
 	.ndo_init		= ipvlan_init,
 	.ndo_uninit		= ipvlan_uninit,
@@ -317,6 +323,7 @@ static const struct net_device_ops ipvlan_netdev_ops = {
 	.ndo_get_stats64	= ipvlan_get_stats64,
 	.ndo_vlan_rx_add_vid	= ipvlan_vlan_rx_add_vid,
 	.ndo_vlan_rx_kill_vid	= ipvlan_vlan_rx_kill_vid,
+	.ndo_get_iflink		= ipvlan_get_iflink,
 };
 
 static int ipvlan_hard_header(struct sk_buff *skb, struct net_device *dev,
diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index b5e3320ca506..b227a13f6473 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -786,7 +786,6 @@ static int macvlan_init(struct net_device *dev)
 	dev->hw_features	|= NETIF_F_LRO;
 	dev->vlan_features	= lowerdev->vlan_features & MACVLAN_FEATURES;
 	dev->gso_max_size	= lowerdev->gso_max_size;
-	dev->iflink		= lowerdev->ifindex;
 	dev->hard_header_len	= lowerdev->hard_header_len;
 
 	macvlan_set_lockdep_class(dev);
@@ -995,6 +994,13 @@ static void macvlan_dev_netpoll_cleanup(struct net_device *dev)
 }
 #endif	/* CONFIG_NET_POLL_CONTROLLER */
 
+static int macvlan_dev_get_iflink(const struct net_device *dev)
+{
+	struct macvlan_dev *vlan = netdev_priv(dev);
+
+	return vlan->lowerdev->ifindex;
+}
+
 static const struct ethtool_ops macvlan_ethtool_ops = {
 	.get_link		= ethtool_op_get_link,
 	.get_settings		= macvlan_ethtool_get_settings,
@@ -1025,6 +1031,7 @@ static const struct net_device_ops macvlan_netdev_ops = {
 	.ndo_netpoll_setup	= macvlan_dev_netpoll_setup,
 	.ndo_netpoll_cleanup	= macvlan_dev_netpoll_cleanup,
 #endif
+	.ndo_get_iflink		= macvlan_dev_get_iflink,
 };
 
 void macvlan_common_setup(struct net_device *dev)
diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index 4cca36ebc4fb..c8186ffda1a3 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -263,6 +263,20 @@ static void veth_poll_controller(struct net_device *dev)
 }
 #endif	/* CONFIG_NET_POLL_CONTROLLER */
 
+static int veth_get_iflink(const struct net_device *dev)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	struct net_device *peer;
+	int iflink;
+
+	rcu_read_lock();
+	peer = rcu_dereference(priv->peer);
+	iflink = peer ? peer->ifindex : 0;
+	rcu_read_unlock();
+
+	return iflink;
+}
+
 static const struct net_device_ops veth_netdev_ops = {
 	.ndo_init            = veth_dev_init,
 	.ndo_open            = veth_open,
@@ -275,6 +289,7 @@ static const struct net_device_ops veth_netdev_ops = {
 #ifdef CONFIG_NET_POLL_CONTROLLER
 	.ndo_poll_controller	= veth_poll_controller,
 #endif
+	.ndo_get_iflink		= veth_get_iflink,
 };
 
 #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_ALL_TSO |    \