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Commit 74a3e5a7 authored by Eric W. Biederman's avatar Eric W. Biederman Committed by David S. Miller
Browse files

tun: Remove unnecessary tun_get_by_name 



Currently the tun driver keeps a private list of tun devices for what
appears to be a small gain in performance when reconnecting a file
descriptor to an existing tun or tap device.  So simplify the code by
removing it.

Signed-off-by: default avatarEric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f5882c30

drivers/net/tun.c

+19 −55
Original line number Original line Diff line number Diff line
@@ -88,7 +88,6 @@ struct tap_filter { 
};

};





struct tun_struct {

struct tun_struct {

	struct list_head        list;

	unsigned int 		flags;

	unsigned int 		flags;

	int			attached;

	int			attached;

	uid_t			owner;

	uid_t			owner;
@@ -213,11 +212,6 @@ static int check_filter(struct tap_filter *filter, const struct sk_buff *skb) 




/* Network device part of the driver */

/* Network device part of the driver */





static int tun_net_id;

struct tun_net {

	struct list_head dev_list;

};



static const struct ethtool_ops tun_ethtool_ops;

static const struct ethtool_ops tun_ethtool_ops;





/* Net device open. */

/* Net device open. */
@@ -697,30 +691,22 @@ static void tun_setup(struct net_device *dev) 
	dev->features |= NETIF_F_NETNS_LOCAL;

	dev->features |= NETIF_F_NETNS_LOCAL;

}

}





static struct tun_struct *tun_get_by_name(struct tun_net *tn, const char *name)

{

	struct tun_struct *tun;



	ASSERT_RTNL();

	list_for_each_entry(tun, &tn->dev_list, list) {

		if (!strncmp(tun->dev->name, name, IFNAMSIZ))

		    return tun;

	}



	return NULL;

}



static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)

static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)

{

{

	struct tun_net *tn;

	struct tun_struct *tun;

	struct tun_struct *tun;

	struct net_device *dev;

	struct net_device *dev;

	const struct cred *cred = current_cred();

	const struct cred *cred = current_cred();

	int err;

	int err;





	tn = net_generic(net, tun_net_id);

	dev = __dev_get_by_name(net, ifr->ifr_name);

	tun = tun_get_by_name(tn, ifr->ifr_name);

	if (dev) {

	if (tun) {

		if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)

			tun = netdev_priv(dev);

		else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)

			tun = netdev_priv(dev);

		else

			return -EINVAL;



		if (tun->attached)

		if (tun->attached)

			return -EBUSY;

			return -EBUSY;
@@ -733,8 +719,6 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) 
			return -EPERM;

			return -EPERM;

		}

		}

	}

	}

	else if (__dev_get_by_name(net, ifr->ifr_name))

		return -EINVAL;

	else {

	else {

		char *name;

		char *name;

		unsigned long flags = 0;

		unsigned long flags = 0;
@@ -782,8 +766,6 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) 
		err = register_netdevice(tun->dev);

		err = register_netdevice(tun->dev);

		if (err < 0)

		if (err < 0)

			goto err_free_dev;

			goto err_free_dev;



		list_add(&tun->list, &tn->dev_list);

	}

	}





	DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);

	DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
@@ -1095,10 +1077,8 @@ static int tun_chr_close(struct inode *inode, struct file *file) 
	/* Drop read queue */

	/* Drop read queue */

	skb_queue_purge(&tun->readq);

	skb_queue_purge(&tun->readq);





	if (!(tun->flags & TUN_PERSIST)) {

	if (!(tun->flags & TUN_PERSIST))

		list_del(&tun->list);

		unregister_netdevice(tun->dev);

		unregister_netdevice(tun->dev);

	}





	rtnl_unlock();

	rtnl_unlock();
@@ -1212,37 +1192,21 @@ static const struct ethtool_ops tun_ethtool_ops = { 




static int tun_init_net(struct net *net)

static int tun_init_net(struct net *net)

{

{

	struct tun_net *tn;



	tn = kmalloc(sizeof(*tn), GFP_KERNEL);

	if (tn == NULL)

		return -ENOMEM;



	INIT_LIST_HEAD(&tn->dev_list);



	if (net_assign_generic(net, tun_net_id, tn)) {

		kfree(tn);

		return -ENOMEM;

	}



	return 0;

	return 0;

}

}





static void tun_exit_net(struct net *net)

static void tun_exit_net(struct net *net)

{

{

	struct tun_net *tn;

	struct net_device *dev, *next;

	struct tun_struct *tun, *nxt;



	tn = net_generic(net, tun_net_id);





	rtnl_lock();

	rtnl_lock();

	list_for_each_entry_safe(tun, nxt, &tn->dev_list, list) {

	for_each_netdev_safe(net, dev, next) {

		DBG(KERN_INFO "%s cleaned up\n", tun->dev->name);

		if (dev->ethtool_ops != &tun_ethtool_ops)

		unregister_netdevice(tun->dev);

			continue;

		DBG(KERN_INFO "%s cleaned up\n", dev->name);

		unregister_netdevice(dev);

	}

	}

	rtnl_unlock();

	rtnl_unlock();



	kfree(tn);

}

}





static struct pernet_operations tun_net_ops = {

static struct pernet_operations tun_net_ops = {
@@ -1257,7 +1221,7 @@ static int __init tun_init(void) 
	printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);

	printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);

	printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);

	printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);





	ret = register_pernet_gen_device(&tun_net_id, &tun_net_ops);

	ret = register_pernet_device(&tun_net_ops);

	if (ret) {

	if (ret) {

		printk(KERN_ERR "tun: Can't register pernet ops\n");

		printk(KERN_ERR "tun: Can't register pernet ops\n");

		goto err_pernet;

		goto err_pernet;
@@ -1271,7 +1235,7 @@ static int __init tun_init(void) 
	return 0;

	return 0;





err_misc:

err_misc:

	unregister_pernet_gen_device(tun_net_id, &tun_net_ops);

	unregister_pernet_device(&tun_net_ops);

err_pernet:

err_pernet:

	return ret;

	return ret;

}

}
@@ -1279,7 +1243,7 @@ static int __init tun_init(void) 
static void tun_cleanup(void)

static void tun_cleanup(void)

{

{

	misc_deregister(&tun_miscdev);

	misc_deregister(&tun_miscdev);

	unregister_pernet_gen_device(tun_net_id, &tun_net_ops);

	unregister_pernet_device(&tun_net_ops);

}

}





module_init(tun_init);

module_init(tun_init);