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Commit 9b5e383c authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net: Introduce unregister_netdevice_many() 



Introduce rollback_registered_many() and unregister_netdevice_many()

rollback_registered_many() is able to perform necessary steps at device dismantle
time, factorizing two expensive synchronize_net() calls.

Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 44a0873d

include/linux/netdevice.h

+1 −0
Original line number Diff line number Diff line
@@ -1119,6 +1119,7 @@ extern int dev_queue_xmit(struct sk_buff *skb); 
extern int		register_netdevice(struct net_device *dev);

extern void		unregister_netdevice_queue(struct net_device *dev,

						   struct list_head *head);

extern void		unregister_netdevice_many(struct list_head *head);

static inline void unregister_netdevice(struct net_device *dev)

{

	unregister_netdevice_queue(dev, NULL);

net/core/dev.c

+65 −32
Original line number Diff line number Diff line
@@ -4637,14 +4637,19 @@ static void net_set_todo(struct net_device *dev) 
	list_add_tail(&dev->todo_list, &net_todo_list);

}



static void rollback_registered(struct net_device *dev)

static void rollback_registered_many(struct list_head *head)

{

	struct net_device *dev;



	BUG_ON(dev_boot_phase);

	ASSERT_RTNL();



	/* Some devices call without registering for initialization unwind. */

	list_for_each_entry(dev, head, unreg_list) {

		/* Some devices call without registering

		 * for initialization unwind.

		 */

		if (dev->reg_state == NETREG_UNINITIALIZED) {

		printk(KERN_DEBUG "unregister_netdevice: device %s/%p never "

			pr_debug("unregister_netdevice: device %s/%p never "

				 "was registered\n", dev->name, dev);



			WARN_ON(1);
@@ -4660,9 +4665,11 @@ static void rollback_registered(struct net_device *dev) 
		unlist_netdevice(dev);



		dev->reg_state = NETREG_UNREGISTERING;

	}



	synchronize_net();



	list_for_each_entry(dev, head, unreg_list) {

		/* Shutdown queueing discipline. */

		dev_shutdown(dev);
@@ -4686,12 +4693,22 @@ static void rollback_registered(struct net_device *dev) 


		/* Remove entries from kobject tree */

		netdev_unregister_kobject(dev);

	}



	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);

}



static void __netdev_init_queue_locks_one(struct net_device *dev,

					  struct netdev_queue *dev_queue,

					  void *_unused)
@@ -5271,6 +5288,22 @@ void unregister_netdevice_queue(struct net_device *dev, struct list_head *head) 
}

EXPORT_SYMBOL(unregister_netdevice_queue);



/**

 *	unregister_netdevice_many - unregister many devices

 *	@head: list of devices

 *

 */

void unregister_netdevice_many(struct list_head *head)

{

	struct net_device *dev;



	if (!list_empty(head)) {

		rollback_registered_many(head);

		list_for_each_entry(dev, head, unreg_list)

			net_set_todo(dev);

	}

}



/**

 *	unregister_netdev - remove device from the kernel

 *	@dev: device