bonding: Manage /proc/net/bonding/ entries from the netdev events

commit a64d49c upstream.

It was recently reported that moving a bonding device between network
namespaces causes warnings from /proc.  It turns out after the move we
were trying to add and to remove the /proc/net/bonding entries from the
wrong network namespace.

Move the bonding /proc registration code into the NETDEV_REGISTER and
NETDEV_UNREGISTER events where the proc registration and unregistration
will always happen at the right time.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/net/bonding/bond_main.c

@@ -3184,6 +3184,12 @@ static int bond_master_netdev_event(unsigned long event,
 	switch (event) {
 	case NETDEV_CHANGENAME:
 		return bond_event_changename(event_bond);
+	case NETDEV_UNREGISTER:
+		bond_remove_proc_entry(event_bond);
+		break;
+	case NETDEV_REGISTER:
+		bond_create_proc_entry(event_bond);
+		break;
 	default:
 		break;
 	}
@@ -4391,8 +4397,6 @@ static void bond_uninit(struct net_device *bond_dev)
 
 	bond_work_cancel_all(bond);
 
-	bond_remove_proc_entry(bond);
-
 	bond_debug_unregister(bond);
 
 	__hw_addr_flush(&bond->mc_list);
@@ -4794,7 +4798,6 @@ static int bond_init(struct net_device *bond_dev)
 
 	bond_set_lockdep_class(bond_dev);
 
-	bond_create_proc_entry(bond);
 	list_add_tail(&bond->bond_list, &bn->dev_list);
 
 	bond_prepare_sysfs_group(bond);