commit c6d14c84566d6b70ad9dc1618db0dec87cca9300
author Eric Dumazet <eric.dumazet@gmail.com> Wed Nov 04 05:43:23 2009 -0800
committer David S. Miller <davem@davemloft.net> Wed Nov 04 05:43:23 2009 -0800
tree 5ec75245cfda4d61e6b4506b6217f047ff4af01a
parent d0075634cf9d288988f57392a1f132d2053af961

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>

net/decnet/af_decnet.c

diff --git a/net/decnet/af_decnet.c b/net/decnet/af_decnet.c
index 664965c..2e35584 100644
--- a/net/decnet/af_decnet.c
+++ b/net/decnet/af_decnet.c
@@ -749,9 +749,9 @@
 
 	if (!(saddr->sdn_flags & SDF_WILD)) {
 		if (le16_to_cpu(saddr->sdn_nodeaddrl)) {
-			read_lock(&dev_base_lock);
+			rcu_read_lock();
 			ldev = NULL;
-			for_each_netdev(&init_net, dev) {
+			for_each_netdev_rcu(&init_net, dev) {
 				if (!dev->dn_ptr)
 					continue;
 				if (dn_dev_islocal(dev, dn_saddr2dn(saddr))) {
@@ -759,7 +759,7 @@
 					break;
 				}
 			}
-			read_unlock(&dev_base_lock);
+			rcu_read_unlock();
 			if (ldev == NULL)
 				return -EADDRNOTAVAIL;
 		}

net/decnet/dn_fib.c

diff --git a/net/decnet/dn_fib.c b/net/decnet/dn_fib.c
index 27ea2e9..fd641f6 100644
--- a/net/decnet/dn_fib.c
+++ b/net/decnet/dn_fib.c
@@ -607,8 +607,8 @@
 	ASSERT_RTNL();
 
 	/* Scan device list */
-	read_lock(&dev_base_lock);
-	for_each_netdev(&init_net, dev) {
+	rcu_read_lock();
+	for_each_netdev_rcu(&init_net, dev) {
 		dn_db = dev->dn_ptr;
 		if (dn_db == NULL)
 			continue;
@@ -619,7 +619,7 @@
 			}
 		}
 	}
-	read_unlock(&dev_base_lock);
+	rcu_read_unlock();
 
 	if (found_it == 0) {
 		fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 16, ifa);

net/decnet/dn_route.c

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);