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Date: Tue, 20 Jan 2009 12:56:20 -0800
From: ebiederm@...ssion.com (Eric W. Biederman)
To: David Miller <davem@...emloft.net>
Cc: <netdev@...r.kernel.org>, Max Krasnyansky <maxk@...lcomm.com>,
Pavel Emelyanov <xemul@...nvz.org>
Subject: [PATCH 01/10] 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: Eric W. Biederman <ebiederm@...stanetworks.com>
---
drivers/net/tun.c | 74 +++++++++++++---------------------------------------
1 files changed, 19 insertions(+), 55 deletions(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index d7b81e4..17923a5 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -88,7 +88,6 @@ struct tap_filter {
};
struct tun_struct {
- struct list_head list;
unsigned int flags;
int attached;
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 */
-static int tun_net_id;
-struct tun_net {
- struct list_head dev_list;
-};
-
static const struct ethtool_ops tun_ethtool_ops;
/* Net device open. */
@@ -697,30 +691,22 @@ static void tun_setup(struct net_device *dev)
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)
{
- struct tun_net *tn;
struct tun_struct *tun;
struct net_device *dev;
const struct cred *cred = current_cred();
int err;
- tn = net_generic(net, tun_net_id);
- tun = tun_get_by_name(tn, ifr->ifr_name);
- if (tun) {
+ dev = __dev_get_by_name(net, ifr->ifr_name);
+ if (dev) {
+ 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)
return -EBUSY;
@@ -733,8 +719,6 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
return -EPERM;
}
}
- else if (__dev_get_by_name(net, ifr->ifr_name))
- return -EINVAL;
else {
char *name;
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);
if (err < 0)
goto err_free_dev;
-
- list_add(&tun->list, &tn->dev_list);
}
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 */
skb_queue_purge(&tun->readq);
- if (!(tun->flags & TUN_PERSIST)) {
- list_del(&tun->list);
+ if (!(tun->flags & TUN_PERSIST))
unregister_netdevice(tun->dev);
- }
rtnl_unlock();
@@ -1212,37 +1192,21 @@ static const struct ethtool_ops tun_ethtool_ops = {
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;
}
static void tun_exit_net(struct net *net)
{
- struct tun_net *tn;
- struct tun_struct *tun, *nxt;
-
- tn = net_generic(net, tun_net_id);
+ struct net_device *dev, *next;
rtnl_lock();
- list_for_each_entry_safe(tun, nxt, &tn->dev_list, list) {
- DBG(KERN_INFO "%s cleaned up\n", tun->dev->name);
- unregister_netdevice(tun->dev);
+ for_each_netdev_safe(net, dev, next) {
+ if (dev->ethtool_ops != &tun_ethtool_ops)
+ continue;
+ DBG(KERN_INFO "%s cleaned up\n", dev->name);
+ unregister_netdevice(dev);
}
rtnl_unlock();
-
- kfree(tn);
}
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\n", DRV_COPYRIGHT);
- ret = register_pernet_gen_device(&tun_net_id, &tun_net_ops);
+ ret = register_pernet_device(&tun_net_ops);
if (ret) {
printk(KERN_ERR "tun: Can't register pernet ops\n");
goto err_pernet;
@@ -1271,7 +1235,7 @@ static int __init tun_init(void)
return 0;
err_misc:
- unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
+ unregister_pernet_device(&tun_net_ops);
err_pernet:
return ret;
}
@@ -1279,7 +1243,7 @@ err_pernet:
static void tun_cleanup(void)
{
misc_deregister(&tun_miscdev);
- unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
+ unregister_pernet_device(&tun_net_ops);
}
module_init(tun_init);
--
1.5.6.3
--
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