Merge branch 'net-devlink-move-netdev-notifier-block-to-dest-namespace-during-reload'

Jiri Pirko says:

====================
net: devlink: move netdev notifier block to dest namespace during reload

Patch #1 is just a dependency of patch #2, which is the actual fix.
====================

Link: https://lore.kernel.org/r/20221108132208.938676-1-jiri@resnulli.usSigned-off-by: Jakub Kicinski <kuba@kernel.org>

include/linux/netdevice.h

@@ -2826,6 +2826,8 @@ int unregister_netdevice_notifier(struct notifier_block *nb);
 int register_netdevice_notifier_net(struct net *net, struct notifier_block *nb);
 int unregister_netdevice_notifier_net(struct net *net,
 				      struct notifier_block *nb);
+void move_netdevice_notifier_net(struct net *src_net, struct net *dst_net,
+				 struct notifier_block *nb);
 int register_netdevice_notifier_dev_net(struct net_device *dev,
 					struct notifier_block *nb,
 					struct netdev_net_notifier *nn);

net/core/dev.c

@@ -1861,6 +1861,22 @@ int unregister_netdevice_notifier_net(struct net *net,
 }
 EXPORT_SYMBOL(unregister_netdevice_notifier_net);
 
+static void __move_netdevice_notifier_net(struct net *src_net,
+					  struct net *dst_net,
+					  struct notifier_block *nb)
+{
+	__unregister_netdevice_notifier_net(src_net, nb);
+	__register_netdevice_notifier_net(dst_net, nb, true);
+}
+
+void move_netdevice_notifier_net(struct net *src_net, struct net *dst_net,
+				 struct notifier_block *nb)
+{
+	rtnl_lock();
+	__move_netdevice_notifier_net(src_net, dst_net, nb);
+	rtnl_unlock();
+}
+
 int register_netdevice_notifier_dev_net(struct net_device *dev,
 					struct notifier_block *nb,
 					struct netdev_net_notifier *nn)
@@ -1897,10 +1913,8 @@ static void move_netdevice_notifiers_dev_net(struct net_device *dev,
 {
 	struct netdev_net_notifier *nn;
 
-	list_for_each_entry(nn, &dev->net_notifier_list, list) {
-		__unregister_netdevice_notifier_net(dev_net(dev), nn->nb);
-		__register_netdevice_notifier_net(net, nn->nb, true);
-	}
+	list_for_each_entry(nn, &dev->net_notifier_list, list)
+		__move_netdevice_notifier_net(dev_net(dev), net, nn->nb);
 }
 
 /**

net/core/devlink.c

@@ -4502,8 +4502,11 @@ static int devlink_reload(struct devlink *devlink, struct net *dest_net,
 	if (err)
 		return err;
 
-	if (dest_net && !net_eq(dest_net, curr_net))
+	if (dest_net && !net_eq(dest_net, curr_net)) {
+		move_netdevice_notifier_net(curr_net, dest_net,
+					    &devlink->netdevice_nb);
 		write_pnet(&devlink->_net, dest_net);
+	}
 
 	err = devlink->ops->reload_up(devlink, action, limit, actions_performed, extack);
 	devlink_reload_failed_set(devlink, !!err);