Commit e51b9624 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net: remove dev_base_lock from register_netdevice() and friends. 



RTNL already protects writes to dev->reg_state, we no longer need to hold
dev_base_lock to protect the readers.

unlist_netdevice() second argument can be removed.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2dd4d828

net/core/dev.c

+7 −13
Original line number Diff line number Diff line
@@ -414,7 +414,7 @@ static void list_netdevice(struct net_device *dev) 
/* Device list removal

 * caller must respect a RCU grace period before freeing/reusing dev

 */

static void unlist_netdevice(struct net_device *dev, bool lock)

static void unlist_netdevice(struct net_device *dev)

{

	struct netdev_name_node *name_node;

	struct net *net = dev_net(dev);
@@ -427,12 +427,10 @@ static void unlist_netdevice(struct net_device *dev, bool lock) 
		netdev_name_node_del(name_node);



	/* Unlink dev from the device chain */

	if (lock)

	write_lock(&dev_base_lock);

	list_del_rcu(&dev->dev_list);

	netdev_name_node_del(dev->name_node);

	hlist_del_rcu(&dev->index_hlist);

	if (lock)

	write_unlock(&dev_base_lock);



	dev_base_seq_inc(dev_net(dev));
@@ -10338,9 +10336,9 @@ int register_netdevice(struct net_device *dev) 
		goto err_ifindex_release;



	ret = netdev_register_kobject(dev);

	write_lock(&dev_base_lock);



	WRITE_ONCE(dev->reg_state, ret ? NETREG_UNREGISTERED : NETREG_REGISTERED);

	write_unlock(&dev_base_lock);



	if (ret)

		goto err_uninit_notify;
@@ -10629,9 +10627,7 @@ void netdev_run_todo(void) 
			continue;

		}



		write_lock(&dev_base_lock);

		WRITE_ONCE(dev->reg_state, NETREG_UNREGISTERED);

		write_unlock(&dev_base_lock);

		linkwatch_sync_dev(dev);

	}
@@ -11138,10 +11134,8 @@ void unregister_netdevice_many_notify(struct list_head *head, 


	list_for_each_entry(dev, head, unreg_list) {

		/* And unlink it from device chain. */

		write_lock(&dev_base_lock);

		unlist_netdevice(dev, false);

		unlist_netdevice(dev);

		WRITE_ONCE(dev->reg_state, NETREG_UNREGISTERING);

		write_unlock(&dev_base_lock);

	}

	flush_all_backlogs();
@@ -11323,7 +11317,7 @@ int __dev_change_net_namespace(struct net_device *dev, struct net *net, 
	dev_close(dev);



	/* And unlink it from device chain */

	unlist_netdevice(dev, true);

	unlist_netdevice(dev);



	synchronize_net();