net: reinstate rtnl in call_netdevice_notifiers()

[deliverable/linux.git] / net / core / dev.c

diff --git a/net/core/dev.c b/net/core/dev.c
index 83988362805ef1453efb37bfcb3692f59f4edd21..bc857fead8c82831b2caa202baf0cff735bd83d2 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1109,11 +1109,23 @@ void netdev_state_change(struct net_device *dev)
 }
 EXPORT_SYMBOL(netdev_state_change);
 
-int netdev_bonding_change(struct net_device *dev, unsigned long event)
+/**
+ *     netdev_notify_peers - notify network peers about existence of @dev
+ *     @dev: network device
+ *
+ * Generate traffic such that interested network peers are aware of
+ * @dev, such as by generating a gratuitous ARP. This may be used when
+ * a device wants to inform the rest of the network about some sort of
+ * reconfiguration such as a failover event or virtual machine
+ * migration.
+ */
+void netdev_notify_peers(struct net_device *dev)
 {
-       return call_netdevice_notifiers(event, dev);
+       rtnl_lock();
+       call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
+       rtnl_unlock();
 }
-EXPORT_SYMBOL(netdev_bonding_change);
+EXPORT_SYMBOL(netdev_notify_peers);
 
 /**
  *     dev_load        - load a network module
@@ -1394,7 +1406,6 @@ rollback:
                                nb->notifier_call(nb, NETDEV_DOWN, dev);
                        }
                        nb->notifier_call(nb, NETDEV_UNREGISTER, dev);
-                       nb->notifier_call(nb, NETDEV_UNREGISTER_BATCH, dev);
                }
        }
 
@@ -1436,7 +1447,6 @@ int unregister_netdevice_notifier(struct notifier_block *nb)
                                nb->notifier_call(nb, NETDEV_DOWN, dev);
                        }
                        nb->notifier_call(nb, NETDEV_UNREGISTER, dev);
-                       nb->notifier_call(nb, NETDEV_UNREGISTER_BATCH, dev);
                }
        }
 unlock:
@@ -5236,12 +5246,12 @@ int dev_ioctl(struct net *net, unsigned int cmd, void __user *arg)
  */
 static int dev_new_index(struct net *net)
 {
-       static int ifindex;
+       int ifindex = net->ifindex;
        for (;;) {
                if (++ifindex <= 0)
                        ifindex = 1;
                if (!__dev_get_by_index(net, ifindex))
-                       return ifindex;
+                       return net->ifindex = ifindex;
        }
 }
 
@@ -5319,10 +5329,6 @@ static void rollback_registered_many(struct list_head *head)
                netdev_unregister_kobject(dev);
        }
 
-       /* Process any work delayed until the end of the batch */
-       dev = list_first_entry(head, struct net_device, unreg_list);
-       call_netdevice_notifiers(NETDEV_UNREGISTER_BATCH, dev);
-
        synchronize_net();
 
        list_for_each_entry(dev, head, unreg_list)
@@ -5594,7 +5600,12 @@ int register_netdevice(struct net_device *dev)
                }
        }
 
-       dev->ifindex = dev_new_index(net);
+       ret = -EBUSY;
+       if (!dev->ifindex)
+               dev->ifindex = dev_new_index(net);
+       else if (__dev_get_by_index(net, dev->ifindex))
+               goto err_uninit;
+
        if (dev->iflink == -1)
                dev->iflink = dev->ifindex;
 
@@ -5770,9 +5781,12 @@ static void netdev_wait_allrefs(struct net_device *dev)
 
                        /* Rebroadcast unregister notification */
                        call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
-                       /* don't resend NETDEV_UNREGISTER_BATCH, _BATCH users
-                        * should have already handle it the first time */
 
+                       __rtnl_unlock();
+                       rcu_barrier();
+                       rtnl_lock();
+
+                       call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
                        if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
                                     &dev->state)) {
                                /* We must not have linkwatch events
@@ -5834,9 +5848,8 @@ void netdev_run_todo(void)
 
        __rtnl_unlock();
 
-       /* Wait for rcu callbacks to finish before attempting to drain
-        * the device list.  This usually avoids a 250ms wait.
-        */
+
+       /* Wait for rcu callbacks to finish before next phase */
        if (!list_empty(&list))
                rcu_barrier();
 
@@ -5845,6 +5858,10 @@ void netdev_run_todo(void)
                        = list_first_entry(&list, struct net_device, todo_list);
                list_del(&dev->todo_list);
 
+               rtnl_lock();
+               call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
+               __rtnl_unlock();
+
                if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
                        pr_err("network todo '%s' but state %d\n",
                               dev->name, dev->reg_state);
@@ -6239,7 +6256,6 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
           the device is just moving and can keep their slaves up.
        */
        call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
-       call_netdevice_notifiers(NETDEV_UNREGISTER_BATCH, dev);
        rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
 
        /*