bonding: make bonding support netpoll

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

Similar to the patch for bridge, this patch does:

1) implement the 2 methods to support netpoll for bonding;

2) modify netpoll during forwarding packets via bonding;

3) disable netpoll support of bonding 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: Jeff Moyer <jmoyer@redhat.com>
Cc: Matt Mackall <mpm@selenic.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>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 98 insertions, 1 deletions

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 85e813c7762..5e12462a9d5 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/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 +431,18 @@ int bond_dev_queue_xmit(struct bonding *bond, struct sk_buff *skb,
         }
 
         skb->priority = 1;
-        dev_queue_xmit(skb);
+#ifdef CONFIG_NET_POLL_CONTROLLER
+        if (unlikely(bond->dev->priv_flags & IFF_IN_NETPOLL)) {
+                struct netpoll *np = bond->dev->npinfo->netpoll;
+                slave_dev->npinfo = bond->dev->npinfo;
+                np->real_dev = np->dev = skb->dev;
+                slave_dev->priv_flags |= IFF_IN_NETPOLL;
+                netpoll_send_skb(np, skb);
+                slave_dev->priv_flags &= ~IFF_IN_NETPOLL;
+                np->dev = bond->dev;
+        } else
+#endif
+                dev_queue_xmit(skb);
 
         return 0;
 }
@@ -1256,6 +1268,61 @@ static void bond_detach_slave(struct bonding *bond, struct slave *slave)
         bond->slave_cnt--;
 }
 
+#ifdef CONFIG_NET_POLL_CONTROLLER
+/*
+ * You must hold read lock on bond->lock before calling this.
+ */
+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;
+
+        bond_for_each_slave(bond, slave, i) {
+                if ((slave->dev->priv_flags & IFF_DISABLE_NETPOLL) ||
+                    !slave->dev->netdev_ops->ndo_poll_controller)
+                        ret = false;
+        }
+        return i != 0 && ret;
+}
+
+static void bond_poll_controller(struct net_device *bond_dev)
+{
+        struct net_device *dev = bond_dev->npinfo->netpoll->real_dev;
+        if (dev != bond_dev)
+                netpoll_poll_dev(dev);
+}
+
+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;
+
+        read_lock(&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;
+                }
+        }
+        read_unlock(&bond->lock);
+}
+
+#else
+
+static void bond_netpoll_cleanup(struct net_device *bond_dev)
+{
+}
+
+#endif
+
 /*---------------------------------- IOCTL ----------------------------------*/
 
 static int bond_sethwaddr(struct net_device *bond_dev,
@@ -1674,6 +1741,18 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
 
         bond_set_carrier(bond);
 
+#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
         read_unlock(&bond->lock);
 
         res = bond_create_slave_symlinks(bond_dev, slave_dev);
@@ -1740,6 +1819,7 @@ int bond_release(struct net_device *bond_dev, struct net_device *slave_dev)
                 return -EINVAL;
         }
 
+        netdev_bonding_change(bond_dev, NETDEV_BONDING_DESLAVE);
         write_lock_bh(&bond->lock);
 
         slave = bond_get_slave_by_dev(bond, slave_dev);
@@ -1868,6 +1948,17 @@ int bond_release(struct net_device *bond_dev, struct net_device *slave_dev)
 
         netdev_set_master(slave_dev, NULL);
 
+#ifdef CONFIG_NET_POLL_CONTROLLER
+        read_lock_bh(&bond->lock);
+        if (slaves_support_netpoll(bond_dev))
+                bond_dev->priv_flags &= ~IFF_DISABLE_NETPOLL;
+        read_unlock_bh(&bond->lock);
+        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);
 
@@ -4406,6 +4497,10 @@ static const struct net_device_ops bond_netdev_ops = {
         .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_cleanup    = bond_netpoll_cleanup,
+        .ndo_poll_controller    = bond_poll_controller,
+#endif
 };
 
 static void bond_destructor(struct net_device *bond_dev)
@@ -4499,6 +4594,8 @@ static void bond_uninit(struct net_device *bond_dev)
 {
         struct bonding *bond = netdev_priv(bond_dev);
 
+        bond_netpoll_cleanup(bond_dev);
+
         /* Release the bonded slaves */
         bond_release_all(bond_dev);