net: Introduce for_each_netdev_rcu() iterator
Adds RCU management to the list of netdevices.
Convert some for_each_netdev() users to RCU version, if
it can avoid read_lock-ing dev_base_lock
Ie:
read_lock(&dev_base_loack);
for_each_netdev(net, dev)
some_action();
read_unlock(&dev_base_lock);
becomes :
rcu_read_lock();
for_each_netdev_rcu(net, dev)
some_action();
rcu_read_unlock();
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/rose/rose_route.c b/net/rose/rose_route.c
index 9478d9b..d936226 100644
--- a/net/rose/rose_route.c
+++ b/net/rose/rose_route.c
@@ -600,13 +600,13 @@
{
struct net_device *dev, *first = NULL;
- read_lock(&dev_base_lock);
- for_each_netdev(&init_net, dev) {
+ rcu_read_lock();
+ for_each_netdev_rcu(&init_net, dev) {
if ((dev->flags & IFF_UP) && dev->type == ARPHRD_ROSE)
if (first == NULL || strncmp(dev->name, first->name, 3) < 0)
first = dev;
}
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
return first;
}
@@ -618,8 +618,8 @@
{
struct net_device *dev;
- read_lock(&dev_base_lock);
- for_each_netdev(&init_net, dev) {
+ rcu_read_lock();
+ for_each_netdev_rcu(&init_net, dev) {
if ((dev->flags & IFF_UP) && dev->type == ARPHRD_ROSE && rosecmp(addr, (rose_address *)dev->dev_addr) == 0) {
dev_hold(dev);
goto out;
@@ -627,7 +627,7 @@
}
dev = NULL;
out:
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
return dev;
}
@@ -635,14 +635,14 @@
{
struct net_device *dev;
- read_lock(&dev_base_lock);
- for_each_netdev(&init_net, dev) {
+ rcu_read_lock();
+ for_each_netdev_rcu(&init_net, dev) {
if ((dev->flags & IFF_UP) && dev->type == ARPHRD_ROSE && rosecmp(addr, (rose_address *)dev->dev_addr) == 0)
goto out;
}
dev = NULL;
out:
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
return dev != NULL;
}