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/decnet/dn_route.c b/net/decnet/dn_route.c
index 57662ca..860286a 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -908,8 +908,8 @@
dev_put(dev_out);
goto out;
}
- read_lock(&dev_base_lock);
- for_each_netdev(&init_net, dev) {
+ rcu_read_lock();
+ for_each_netdev_rcu(&init_net, dev) {
if (!dev->dn_ptr)
continue;
if (!dn_dev_islocal(dev, oldflp->fld_src))
@@ -922,7 +922,7 @@
dev_out = dev;
break;
}
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
if (dev_out == NULL)
goto out;
dev_hold(dev_out);