[Bridge] [RFC Patch 3/3] bonding: make bonding support netpoll

[Amerigo Wang <amwang@redhat.com>]

Based on Andy's work, but I modify a lot.

Similar to the patch for bridge, this patch does:

1) implement the 4 methods to support netpoll for bonding;

2) modify netpoll during forwarding packets in bonding;

3) disable netpoll support of bridge when a netpoll-unabled device
   is added to bonding;

4) enable netpoll support when all underlying devices support netpoll.

Cc: Andy Gospodarek <gospo@redhat.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Jay Vosburgh <fubar@us.ibm.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: WANG Cong <amwang@redhat.com>


---
Index: linux-2.6/drivers/net/bonding/bond_main.c
===================================================================
--- linux-2.6.orig/drivers/net/bonding/bond_main.c
+++ linux-2.6/drivers/net/bonding/bond_main.c
@@ -59,6 +59,7 @@
 #include <linux/uaccess.h>
 #include <linux/errno.h>
 #include <linux/netdevice.h>
+#include <linux/netpoll.h>
 #include <linux/inetdevice.h>
 #include <linux/igmp.h>
 #include <linux/etherdevice.h>
@@ -430,7 +431,17 @@ int bond_dev_queue_xmit(struct bonding *
 	}
 
 	skb->priority = 1;
-	dev_queue_xmit(skb);
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	if (bond->dev->priv_flags & IFF_IN_NETPOLL) {
+		bond->dev->npinfo->netpoll->dev = skb->dev;
+		if (!slave_dev->npinfo)
+			slave_dev->npinfo = bond->dev->npinfo;
+		slave_dev->priv_flags |= IFF_IN_NETPOLL;
+		netpoll_send_skb(bond->dev->npinfo->netpoll, skb);
+		slave_dev->priv_flags &= ~IFF_IN_NETPOLL;
+	} else
+#endif
+		dev_queue_xmit(skb);
 
 	return 0;
 }
@@ -1324,6 +1335,87 @@ static void bond_detach_slave(struct bon
 	bond->slave_cnt--;
 }
 
+#ifdef CONFIG_NET_POLL_CONTROLLER
+static bool slaves_support_netpoll(struct net_device *bond_dev)
+{
+	struct bonding *bond = netdev_priv(bond_dev);
+	struct slave *slave;
+	int i = 0;
+	bool ret = true;
+
+	read_lock_bh(&bond->lock);
+	bond_for_each_slave(bond, slave, i) {
+		if ((slave->dev->priv_flags & IFF_DISABLE_NETPOLL)
+				|| !slave->dev->netdev_ops->ndo_poll_controller)
+			ret = false;
+	}
+	read_unlock_bh(&bond->lock);
+	return i != 0 && ret;
+}
+
+static void bond_poll_controller(struct net_device *bond_dev)
+{
+	struct bonding *bond = netdev_priv(bond_dev);
+	struct slave *slave;
+	int i;
+
+	read_lock(&bond->lock);
+	bond_for_each_slave(bond, slave, i) {
+		if (slave->dev->netdev_ops->ndo_poll_controller)
+			netpoll_poll_dev(slave->dev);
+	}
+	read_unlock(&bond->lock);
+}
+
+static void bond_netpoll_setup(struct net_device *bond_dev,
+			      struct netpoll_info *npinfo)
+{
+	struct bonding *bond = netdev_priv(bond_dev);
+	struct slave *slave;
+	int i;
+
+	write_lock_bh(&bond->lock);
+	bond_for_each_slave(bond, slave, i) {
+		if (slave->dev)
+			slave->dev->npinfo = npinfo;
+	}
+	write_unlock_bh(&bond->lock);
+}
+
+static void bond_netpoll_cleanup(struct net_device *bond_dev)
+{
+	struct bonding *bond = netdev_priv(bond_dev);
+	struct slave *slave;
+	const struct net_device_ops *ops;
+	int i;
+
+	write_lock_bh(&bond->lock);
+	bond_dev->npinfo = NULL;
+	bond_for_each_slave(bond, slave, i) {
+		if (slave->dev) {
+			ops = slave->dev->netdev_ops;
+			if (ops->ndo_netpoll_cleanup)
+				ops->ndo_netpoll_cleanup(slave->dev);
+			else
+				slave->dev->npinfo = NULL;
+		}
+	}
+	write_unlock_bh(&bond->lock);
+}
+
+static int bond_netpoll_xmit(struct netpoll *np, struct sk_buff *skb,
+			     struct net_device *dev)
+{
+	int ret;
+
+	dev->priv_flags |= IFF_IN_NETPOLL;
+	ret = dev->netdev_ops->ndo_start_xmit(skb, dev);
+	np->dev = dev;
+	dev->priv_flags &= ~IFF_IN_NETPOLL;
+	return ret;
+}
+#endif
+
 /*---------------------------------- IOCTL ----------------------------------*/
 
 static int bond_sethwaddr(struct net_device *bond_dev,
@@ -1741,6 +1833,18 @@ int bond_enslave(struct net_device *bond
 		new_slave->state == BOND_STATE_ACTIVE ? "n active" : " backup",
 		new_slave->link != BOND_LINK_DOWN ? "n up" : " down");
 
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	if (slaves_support_netpoll(bond_dev)) {
+		bond_dev->priv_flags &= ~IFF_DISABLE_NETPOLL;
+		if (bond_dev->npinfo)
+			slave_dev->npinfo = bond_dev->npinfo;
+	} else if (!(bond_dev->priv_flags & IFF_DISABLE_NETPOLL)) {
+		bond_dev->priv_flags |= IFF_DISABLE_NETPOLL;
+		pr_info("New slave device %s does not support netpoll\n",
+			slave_dev->name);
+		pr_info("Disabling netpoll support for %s\n", bond_dev->name);
+	}
+#endif
 	/* enslave is successful */
 	return 0;
 
@@ -1924,6 +2028,15 @@ int bond_release(struct net_device *bond
 
 	netdev_set_master(slave_dev, NULL);
 
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	if (slaves_support_netpoll(bond_dev))
+		bond_dev->priv_flags &= ~IFF_DISABLE_NETPOLL;
+	if (slave_dev->netdev_ops->ndo_netpoll_cleanup)
+		slave_dev->netdev_ops->ndo_netpoll_cleanup(slave_dev);
+	else
+		slave_dev->npinfo = NULL;
+#endif
+
 	/* close slave before restoring its mac address */
 	dev_close(slave_dev);
 
@@ -2032,6 +2145,9 @@ static int bond_release_all(struct net_d
 
 		netdev_set_master(slave_dev, NULL);
 
+#ifdef CONFIG_NET_POLL_CONTROLLER
+		slave_dev->npinfo = NULL;
+#endif
 		/* close slave before restoring its mac address */
 		dev_close(slave_dev);
 
@@ -4424,6 +4540,12 @@ static const struct net_device_ops bond_
 	.ndo_vlan_rx_register	= bond_vlan_rx_register,
 	.ndo_vlan_rx_add_vid 	= bond_vlan_rx_add_vid,
 	.ndo_vlan_rx_kill_vid	= bond_vlan_rx_kill_vid,
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	.ndo_netpoll_setup	= bond_netpoll_setup,
+	.ndo_netpoll_xmit	= bond_netpoll_xmit,
+	.ndo_netpoll_cleanup	= bond_netpoll_cleanup,
+	.ndo_poll_controller	= bond_poll_controller,
+#endif
 };
 
 static void bond_setup(struct net_device *bond_dev)