Commit e7689879 authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

ethtool: do not use rtnl in ethnl_default_dumpit() 



for_each_netdev_dump() can be used with RCU protection,
no need for rtnl if we are going to use dev_hold()/dev_put().

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240207153514.3640952-1-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent fd0bb2c7

net/ethtool/netlink.c

+5 −9
Original line number Diff line number Diff line
@@ -477,11 +477,7 @@ static int ethnl_default_dump_one(struct sk_buff *skb, struct net_device *dev, 
	return ret;

}



/* Default ->dumpit() handler for GET requests. Device iteration copied from

 * rtnl_dump_ifinfo(); we have to be more careful about device hashtable

 * persistence as we cannot guarantee to hold RTNL lock through the whole

 * function as rtnetnlink does.

 */

/* Default ->dumpit() handler for GET requests. */

static int ethnl_default_dumpit(struct sk_buff *skb,

				struct netlink_callback *cb)

{
@@ -490,14 +486,14 @@ static int ethnl_default_dumpit(struct sk_buff *skb, 
	struct net_device *dev;

	int ret = 0;



	rtnl_lock();

	rcu_read_lock();

	for_each_netdev_dump(net, dev, ctx->pos_ifindex) {

		dev_hold(dev);

		rtnl_unlock();

		rcu_read_unlock();



		ret = ethnl_default_dump_one(skb, dev, ctx, genl_info_dump(cb));



		rtnl_lock();

		rcu_read_lock();

		dev_put(dev);



		if (ret < 0 && ret != -EOPNOTSUPP) {
@@ -507,7 +503,7 @@ static int ethnl_default_dumpit(struct sk_buff *skb, 
		}

		ret = 0;

	}

	rtnl_unlock();

	rcu_read_unlock();



	return ret;

}