Commit d29aee60 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'net-inline-rollback_registered-functions' 

After recent changes to the error path of register_netdevice()
we no longer need a version of unregister_netdevice_many() which
does not set net_todo. We can inline the rollback_registered()
functions into respective unregister_netdevice() calls.

Link: https://lore.kernel.org/r/20210119202521.3108236-1-kuba@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents 5ff96aec 0cbe1e57

net/core/dev.c

+98 −112
Original line number Diff line number Diff line
@@ -5709,7 +5709,7 @@ static void flush_all_backlogs(void) 
	}



	/* we can have in flight packet[s] on the cpus we are not flushing,

	 * synchronize_net() in rollback_registered_many() will take care of

	 * synchronize_net() in unregister_netdevice_many() will take care of

	 * them

	 */

	for_each_cpu(cpu, &flush_cpus)
@@ -9459,106 +9459,6 @@ static void net_set_todo(struct net_device *dev) 
	dev_net(dev)->dev_unreg_count++;

}



static void rollback_registered_many(struct list_head *head)

{

	struct net_device *dev, *tmp;

	LIST_HEAD(close_head);



	BUG_ON(dev_boot_phase);

	ASSERT_RTNL();



	list_for_each_entry_safe(dev, tmp, head, unreg_list) {

		/* Some devices call without registering

		 * for initialization unwind. Remove those

		 * devices and proceed with the remaining.

		 */

		if (dev->reg_state == NETREG_UNINITIALIZED) {

			pr_debug("unregister_netdevice: device %s/%p never was registered\n",

				 dev->name, dev);



			WARN_ON(1);

			list_del(&dev->unreg_list);

			continue;

		}

		dev->dismantle = true;

		BUG_ON(dev->reg_state != NETREG_REGISTERED);

	}



	/* If device is running, close it first. */

	list_for_each_entry(dev, head, unreg_list)

		list_add_tail(&dev->close_list, &close_head);

	dev_close_many(&close_head, true);



	list_for_each_entry(dev, head, unreg_list) {

		/* And unlink it from device chain. */

		unlist_netdevice(dev);



		dev->reg_state = NETREG_UNREGISTERING;

	}

	flush_all_backlogs();



	synchronize_net();



	list_for_each_entry(dev, head, unreg_list) {

		struct sk_buff *skb = NULL;



		/* Shutdown queueing discipline. */

		dev_shutdown(dev);



		dev_xdp_uninstall(dev);



		/* Notify protocols, that we are about to destroy

		 * this device. They should clean all the things.

		 */

		call_netdevice_notifiers(NETDEV_UNREGISTER, dev);



		if (!dev->rtnl_link_ops ||

		    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)

			skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U, 0,

						     GFP_KERNEL, NULL, 0);



		/*

		 *	Flush the unicast and multicast chains

		 */

		dev_uc_flush(dev);

		dev_mc_flush(dev);



		netdev_name_node_alt_flush(dev);

		netdev_name_node_free(dev->name_node);



		if (dev->netdev_ops->ndo_uninit)

			dev->netdev_ops->ndo_uninit(dev);



		if (skb)

			rtmsg_ifinfo_send(skb, dev, GFP_KERNEL);



		/* Notifier chain MUST detach us all upper devices. */

		WARN_ON(netdev_has_any_upper_dev(dev));

		WARN_ON(netdev_has_any_lower_dev(dev));



		/* Remove entries from kobject tree */

		netdev_unregister_kobject(dev);

#ifdef CONFIG_XPS

		/* Remove XPS queueing entries */

		netif_reset_xps_queues_gt(dev, 0);

#endif

	}



	synchronize_net();



	list_for_each_entry(dev, head, unreg_list)

		dev_put(dev);

}



static void rollback_registered(struct net_device *dev)

{

	LIST_HEAD(single);



	list_add(&dev->unreg_list, &single);

	rollback_registered_many(&single);

	list_del(&single);

}



static netdev_features_t netdev_sync_upper_features(struct net_device *lower,

	struct net_device *upper, netdev_features_t features)

{
@@ -10108,8 +10008,7 @@ int register_netdevice(struct net_device *dev) 
	if (ret) {

		/* Expect explicit free_netdev() on failure */

		dev->needs_free_netdev = false;

		rollback_registered(dev);

		net_set_todo(dev);

		unregister_netdevice_queue(dev, NULL);

		goto out;

	}

	/*
@@ -10731,9 +10630,10 @@ void unregister_netdevice_queue(struct net_device *dev, struct list_head *head) 
	if (head) {

		list_move_tail(&dev->unreg_list, head);

	} else {

		rollback_registered(dev);

		/* Finish processing unregister after unlock */

		net_set_todo(dev);

		LIST_HEAD(single);



		list_add(&dev->unreg_list, &single);

		unregister_netdevice_many(&single);

	}

}

EXPORT_SYMBOL(unregister_netdevice_queue);
@@ -10747,14 +10647,100 @@ EXPORT_SYMBOL(unregister_netdevice_queue); 
 */

void unregister_netdevice_many(struct list_head *head)

{

	struct net_device *dev;

	struct net_device *dev, *tmp;

	LIST_HEAD(close_head);



	BUG_ON(dev_boot_phase);

	ASSERT_RTNL();



	if (!list_empty(head)) {

		rollback_registered_many(head);

	if (list_empty(head))

		return;



	list_for_each_entry_safe(dev, tmp, head, unreg_list) {

		/* Some devices call without registering

		 * for initialization unwind. Remove those

		 * devices and proceed with the remaining.

		 */

		if (dev->reg_state == NETREG_UNINITIALIZED) {

			pr_debug("unregister_netdevice: device %s/%p never was registered\n",

				 dev->name, dev);



			WARN_ON(1);

			list_del(&dev->unreg_list);

			continue;

		}

		dev->dismantle = true;

		BUG_ON(dev->reg_state != NETREG_REGISTERED);

	}



	/* If device is running, close it first. */

	list_for_each_entry(dev, head, unreg_list)

		list_add_tail(&dev->close_list, &close_head);

	dev_close_many(&close_head, true);



	list_for_each_entry(dev, head, unreg_list) {

		/* And unlink it from device chain. */

		unlist_netdevice(dev);



		dev->reg_state = NETREG_UNREGISTERING;

	}

	flush_all_backlogs();



	synchronize_net();



	list_for_each_entry(dev, head, unreg_list) {

		struct sk_buff *skb = NULL;



		/* Shutdown queueing discipline. */

		dev_shutdown(dev);



		dev_xdp_uninstall(dev);



		/* Notify protocols, that we are about to destroy

		 * this device. They should clean all the things.

		 */

		call_netdevice_notifiers(NETDEV_UNREGISTER, dev);



		if (!dev->rtnl_link_ops ||

		    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)

			skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U, 0,

						     GFP_KERNEL, NULL, 0);



		/*

		 *	Flush the unicast and multicast chains

		 */

		dev_uc_flush(dev);

		dev_mc_flush(dev);



		netdev_name_node_alt_flush(dev);

		netdev_name_node_free(dev->name_node);



		if (dev->netdev_ops->ndo_uninit)

			dev->netdev_ops->ndo_uninit(dev);



		if (skb)

			rtmsg_ifinfo_send(skb, dev, GFP_KERNEL);



		/* Notifier chain MUST detach us all upper devices. */

		WARN_ON(netdev_has_any_upper_dev(dev));

		WARN_ON(netdev_has_any_lower_dev(dev));



		/* Remove entries from kobject tree */

		netdev_unregister_kobject(dev);

#ifdef CONFIG_XPS

		/* Remove XPS queueing entries */

		netif_reset_xps_queues_gt(dev, 0);

#endif

	}



	synchronize_net();



	list_for_each_entry(dev, head, unreg_list) {

		dev_put(dev);

		net_set_todo(dev);

		list_del(head);

	}



	list_del(head);

}

EXPORT_SYMBOL(unregister_netdevice_many);