From 7562f876cd93800f2f8c89445f2a563590b24e09 Mon Sep 17 00:00:00 2001 From: Pavel Emelianov Date: Thu, 3 May 2007 15:13:45 -0700 Subject: [NET]: Rework dev_base via list_head (v3) Cleanup of dev_base list use, with the aim to simplify making device list per-namespace. In almost every occasion, use of dev_base variable and dev->next pointer could be easily replaced by for_each_netdev loop. A few most complicated places were converted to using first_netdev()/next_netdev(). Signed-off-by: Pavel Emelianov Acked-by: Kirill Korotaev Signed-off-by: David S. Miller --- net/core/dev.c | 84 ++++++++++++++++++++++++++-------------------------------- 1 file changed, 38 insertions(+), 46 deletions(-) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index c305819b7266..f27d4ab181e6 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -156,13 +156,13 @@ static spinlock_t net_dma_event_lock; #endif /* - * The @dev_base list is protected by @dev_base_lock and the rtnl + * The @dev_base_head list is protected by @dev_base_lock and the rtnl * semaphore. * * Pure readers hold dev_base_lock for reading. * * Writers must hold the rtnl semaphore while they loop through the - * dev_base list, and hold dev_base_lock for writing when they do the + * dev_base_head list, and hold dev_base_lock for writing when they do the * actual updates. This allows pure readers to access the list even * while a writer is preparing to update it. * @@ -174,11 +174,10 @@ static spinlock_t net_dma_event_lock; * unregister_netdevice(), which must be called with the rtnl * semaphore held. */ -struct net_device *dev_base; -static struct net_device **dev_tail = &dev_base; +LIST_HEAD(dev_base_head); DEFINE_RWLOCK(dev_base_lock); -EXPORT_SYMBOL(dev_base); +EXPORT_SYMBOL(dev_base_head); EXPORT_SYMBOL(dev_base_lock); #define NETDEV_HASHBITS 8 @@ -567,11 +566,12 @@ struct net_device *dev_getbyhwaddr(unsigned short type, char *ha) 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); @@ -581,11 +581,11 @@ struct net_device *__dev_getfirstbyhwtype(unsigned short type) struct net_device *dev; ASSERT_RTNL(); - for (dev = dev_base; dev; dev = dev->next) { + for_each_netdev(dev) if (dev->type == type) - break; - } - return dev; + return dev; + + return NULL; } EXPORT_SYMBOL(__dev_getfirstbyhwtype); @@ -617,17 +617,19 @@ EXPORT_SYMBOL(dev_getfirstbyhwtype); struct net_device * dev_get_by_flags(unsigned short if_flags, unsigned short mask) { - struct net_device *dev; + struct net_device *dev, *ret; + ret = NULL; 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); + ret = dev; break; } } read_unlock(&dev_base_lock); - return dev; + return ret; } /** @@ -693,7 +695,7 @@ int dev_alloc_name(struct net_device *dev, const char *name) 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) @@ -975,7 +977,7 @@ int register_netdevice_notifier(struct notifier_block *nb) 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) @@ -2049,7 +2051,7 @@ 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; @@ -2081,26 +2083,28 @@ static int dev_ifconf(char __user *arg) * This is invoked by the /proc filesystem handler to display a device * in detail. */ -static struct net_device *dev_get_idx(loff_t pos) +void *dev_seq_start(struct seq_file *seq, loff_t *pos) { + loff_t off; struct net_device *dev; - loff_t i; - for (i = 0, dev = dev_base; dev && i < pos; ++i, dev = dev->next); + read_lock(&dev_base_lock); + if (!*pos) + return SEQ_START_TOKEN; - return i == pos ? dev : NULL; -} + off = 1; + for_each_netdev(dev) + if (off++ == *pos) + return dev; -void *dev_seq_start(struct seq_file *seq, loff_t *pos) -{ - read_lock(&dev_base_lock); - return *pos ? dev_get_idx(*pos - 1) : SEQ_START_TOKEN; + return NULL; } void *dev_seq_next(struct seq_file *seq, void *v, loff_t *pos) { ++*pos; - return v == SEQ_START_TOKEN ? dev_base : ((struct net_device *)v)->next; + return v == SEQ_START_TOKEN ? + first_net_device() : next_net_device((struct net_device *)v); } void dev_seq_stop(struct seq_file *seq, void *v) @@ -3082,11 +3086,9 @@ int register_netdevice(struct net_device *dev) set_bit(__LINK_STATE_PRESENT, &dev->state); - dev->next = NULL; dev_init_scheduler(dev); 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); @@ -3360,8 +3362,6 @@ void synchronize_net(void) void unregister_netdevice(struct net_device *dev) { - struct net_device *d, **dp; - BUG_ON(dev_boot_phase); ASSERT_RTNL(); @@ -3381,19 +3381,11 @@ void unregister_netdevice(struct net_device *dev) dev_close(dev); /* 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); - break; - } - } - BUG_ON(!d); + write_lock_bh(&dev_base_lock); + list_del(&dev->dev_list); + hlist_del(&dev->name_hlist); + hlist_del(&dev->index_hlist); + write_unlock_bh(&dev_base_lock); dev->reg_state = NETREG_UNREGISTERING; -- cgit v1.2.3-59-g8ed1b