Cleanup of net_device list use in net_dev core and IP.
The cleanup consists of
- converting the to list_head, to make the list double-linked (thus making
remove operation O(1)), and list walks more readable;
- introducing of for_each_netdev wrapper over list_for_each.
Signed-off-by: Andrey Savochkin <[EMAIL PROTECTED]>
Signed-off-by: Kirill Korotaev <[EMAIL PROTECTED]>
---
include/linux/netdevice.h | 29 ++++++++++++++++++++++++++-
net/core/dev.c | 48 +++++++++++++++++++++++++---------------------
net/ipv4/devinet.c | 6 ++---
net/ipv6/addrconf.c | 8 +++----
net/ipv6/anycast.c | 10 +++++----
5 files changed, 68 insertions(+), 33 deletions(-)
--- ./include/linux/netdevice.h.vedevbase-core Mon Jul 3 15:14:15 2006
+++ ./include/linux/netdevice.h Mon Jul 3 16:09:11 2006
@@ -290,7 +290,8 @@ struct net_device
unsigned long state;
struct net_device *next;
-
+ struct list_head dev_list;
+
/* The device initialization function. Called only once. */
int (*init)(struct net_device *dev);
@@ -558,8 +559,34 @@ struct packet_type {
extern struct net_device loopback_dev; /* The loopback
*/
extern struct net_device *dev_base; /* All devices
*/
+extern struct list_head dev_base_head; /* All
devices */
extern rwlock_t dev_base_lock; /*
Device list lock */
+#define for_each_netdev(p) list_for_each_entry(p, &dev_base_head, dev_list)
+
+/*
+ * When possible, it is preferrable to use for_each_netdev() loop
+ * defined above, rather than first_netdev()/next_netdev() macros.
+ * for_each_netdev() loop makes the intentions clearer, and gives more
+ * flexibility in device list implementation.
+ * While next_netdev() is unavoidable in seq_proc functions,
+ * first_netdev() should be needed quite rarely.
+ */
+#define first_netdev() ({ \
+ list_empty(&dev_base_head) ? NULL : \
+ list_entry(dev_base_head.next, \
+ struct net_device, \
+ dev_list); \
+ })
+#define next_netdev(dev) ({ \
+ struct list_head *__next; \
+ __next = (dev)->dev_list.next; \
+ __next == &dev_base_head ? NULL : \
+ list_entry(__next, \
+ struct net_device, \
+ dev_list); \
+ })
+
extern int netdev_boot_setup_check(struct net_device *dev);
extern unsigned long netdev_boot_base(const char *prefix, int unit);
extern struct net_device *dev_getbyhwaddr(unsigned short type, char
*hwaddr);
--- ./net/core/dev.c.vedevbase-core Mon Jul 3 15:14:19 2006
+++ ./net/core/dev.c Mon Jul 3 16:09:11 2006
@@ -181,6 +181,9 @@ DEFINE_RWLOCK(dev_base_lock);
EXPORT_SYMBOL(dev_base);
EXPORT_SYMBOL(dev_base_lock);
+LIST_HEAD(dev_base_head);
+EXPORT_SYMBOL(dev_base_head);
+
#define NETDEV_HASHBITS 8
static struct hlist_head dev_name_head[1<<NETDEV_HASHBITS];
static struct hlist_head dev_index_head[1<<NETDEV_HASHBITS];
@@ -575,11 +578,11 @@ struct net_device *dev_getbyhwaddr(unsig
ASSERT_RTNL();
- for (dev = dev_base; dev; dev = dev->next)
+ for_each_netdev(dev)
if (dev->type == type &&
!memcmp(dev->dev_addr, ha, dev->addr_len))
- break;
- return dev;
+ return dev;
+ return NULL;
}
EXPORT_SYMBOL(dev_getbyhwaddr);
@@ -589,14 +592,15 @@ struct net_device *dev_getfirstbyhwtype(
struct net_device *dev;
rtnl_lock();
- for (dev = dev_base; dev; dev = dev->next) {
+ for_each_netdev(dev) {
if (dev->type == type) {
dev_hold(dev);
- break;
+ rtnl_unlock();
+ return dev;
}
}
rtnl_unlock();
- return dev;
+ return NULL;
}
EXPORT_SYMBOL(dev_getfirstbyhwtype);
@@ -617,14 +621,15 @@ struct net_device * dev_get_by_flags(uns
struct net_device *dev;
read_lock(&dev_base_lock);
- for (dev = dev_base; dev != NULL; dev = dev->next) {
+ for_each_netdev(dev) {
if (((dev->flags ^ if_flags) & mask) == 0) {
dev_hold(dev);
- break;
+ read_unlock(&dev_base_lock);
+ return dev;
}
}
read_unlock(&dev_base_lock);
- return dev;
+ return NULL;
}
/**
@@ -680,7 +685,7 @@ int dev_alloc_name(struct net_device *de
if (!inuse)
return -ENOMEM;
- for (d = dev_base; d; d = d->next) {
+ for_each_netdev(d) {
if (!sscanf(d->name, name, &i))
continue;
if (i < 0 || i >= max_netdevices)
@@ -966,7 +971,7 @@ int register_netdevice_notifier(struct n
rtnl_lock();
err = raw_notifier_chain_register(&netdev_chain, nb);
if (!err) {
- for (dev = dev_base; dev; dev = dev->next) {
+ for_each_netdev(dev) {
nb->notifier_call(nb, NETDEV_REGISTER, dev);
if (dev->flags & IFF_UP)
@@ -2035,7 +2040,7 @@ static int dev_ifconf(char __user *arg)
*/
total = 0;
- for (dev = dev_base; dev; dev = dev->next) {
+ for_each_netdev(dev) {
for (i = 0; i < NPROTO; i++) {
if (gifconf_list[i]) {
int done;
@@ -2974,6 +2979,7 @@ int register_netdevice(struct net_device
write_lock_bh(&dev_base_lock);
*dev_tail = dev;
dev_tail = &dev->next;
+ list_add_tail(&dev->dev_list, &dev_base_head);
hlist_add_head(&dev->name_hlist, head);
hlist_add_head(&dev->index_hlist, dev_index_hash(dev->ifindex));
dev_hold(dev);
@@ -3271,22 +3277,22 @@ int unregister_netdevice(struct net_devi
/* And unlink it from device chain. */
for (dp = &dev_base; (d = *dp) != NULL; dp = &d->next) {
- if (d == dev) {
- write_lock_bh(&dev_base_lock);
- hlist_del(&dev->name_hlist);
- hlist_del(&dev->index_hlist);
- if (dev_tail == &dev->next)
- dev_tail = dp;
- *dp = d->next;
- write_unlock_bh(&dev_base_lock);
+ if (d == dev)
break;
- }
}
if (!d) {
printk(KERN_ERR "unregister net_device: '%s' not found\n",
dev->name);
return -ENODEV;
}
+ write_lock_bh(&dev_base_lock);
+ list_del(&dev->dev_list);
+ hlist_del(&dev->name_hlist);
+ hlist_del(&dev->index_hlist);
+ if (dev_tail == &dev->next)
+ dev_tail = dp;
+ *dp = d->next;
+ write_unlock_bh(&dev_base_lock);
dev->reg_state = NETREG_UNREGISTERING;
--- ./net/ipv4/devinet.c.vedevbase-core Mon Jul 3 15:14:20 2006
+++ ./net/ipv4/devinet.c Mon Jul 3 16:09:11 2006
@@ -841,7 +841,7 @@ no_in_dev:
*/
read_lock(&dev_base_lock);
rcu_read_lock();
- for (dev = dev_base; dev; dev = dev->next) {
+ for_each_netdev(dev) {
if ((in_dev = __in_dev_get_rcu(dev)) == NULL)
continue;
@@ -920,7 +920,7 @@ u32 inet_confirm_addr(const struct net_d
read_lock(&dev_base_lock);
rcu_read_lock();
- for (dev = dev_base; dev; dev = dev->next) {
+ for_each_netdev(dev) {
if ((in_dev = __in_dev_get_rcu(dev))) {
addr = confirm_addr_indev(in_dev, dst, local, scope);
if (addr)
@@ -1170,7 +1170,7 @@ void inet_forward_change(void)
ipv4_devconf_dflt.forwarding = on;
read_lock(&dev_base_lock);
- for (dev = dev_base; dev; dev = dev->next) {
+ for_each_netdev(dev) {
struct in_device *in_dev;
rcu_read_lock();
in_dev = __in_dev_get_rcu(dev);
--- ./net/ipv6/addrconf.c.vedevbase-core Mon Jul 3 15:14:22 2006
+++ ./net/ipv6/addrconf.c Mon Jul 3 16:09:11 2006
@@ -469,7 +469,7 @@ static void addrconf_forward_change(void
struct inet6_dev *idev;
read_lock(&dev_base_lock);
- for (dev=dev_base; dev; dev=dev->next) {
+ for_each_netdev(dev) {
read_lock(&addrconf_lock);
idev = __in6_dev_get(dev);
if (idev) {
@@ -894,7 +894,7 @@ int ipv6_dev_get_saddr(struct net_device
read_lock(&dev_base_lock);
read_lock(&addrconf_lock);
- for (dev = dev_base; dev; dev=dev->next) {
+ for_each_netdev(dev) {
struct inet6_dev *idev;
struct inet6_ifaddr *ifa;
@@ -1979,7 +1979,7 @@ static void sit_add_v4_addrs(struct inet
return;
}
- for (dev = dev_base; dev != NULL; dev = dev->next) {
+ for_each_netdev(dev) {
struct in_device * in_dev = __in_dev_get_rtnl(dev);
if (in_dev && (dev->flags & IFF_UP)) {
struct in_ifaddr * ifa;
@@ -2128,7 +2128,7 @@ static void ip6_tnl_add_linklocal(struct
return;
}
/* then try to inherit it from any device */
- for (link_dev = dev_base; link_dev; link_dev = link_dev->next) {
+ for_each_netdev(link_dev) {
if (!ipv6_inherit_linklocal(idev, link_dev))
return;
}
--- ./net/ipv6/anycast.c.vedevbase-core Mon Jul 3 15:14:22 2006
+++ ./net/ipv6/anycast.c Mon Jul 3 16:09:11 2006
@@ -427,11 +427,13 @@ int ipv6_chk_acast_addr(struct net_devic
if (dev)
return ipv6_chk_acast_dev(dev, addr);
read_lock(&dev_base_lock);
- for (dev=dev_base; dev; dev=dev->next)
- if (ipv6_chk_acast_dev(dev, addr))
- break;
+ for_each_netdev(dev)
+ if (ipv6_chk_acast_dev(dev, addr)) {
+ read_unlock(&dev_base_lock);
+ return 1;
+ }
read_unlock(&dev_base_lock);
- return dev != 0;
+ return 0;
}
-
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