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Commit c68f24cc authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

ipv6: RCU changes in ipv6_get_mtu() and ip6_dst_hoplimit() 



Use RCU to avoid atomic ops on idev refcnt in ipv6_get_mtu()
and ip6_dst_hoplimit()

Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Acked-by: default avatarYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f6bc7d9e

net/ipv6/route.c

+11 −8
Original line number Diff line number Diff line
@@ -1084,11 +1084,11 @@ static int ipv6_get_mtu(struct net_device *dev) 
	int mtu = IPV6_MIN_MTU;

	struct inet6_dev *idev;



	idev = in6_dev_get(dev);

	if (idev) {

	rcu_read_lock();

	idev = __in6_dev_get(dev);

	if (idev)

		mtu = idev->cnf.mtu6;

		in6_dev_put(idev);

	}

	rcu_read_unlock();

	return mtu;

}
@@ -1097,12 +1097,15 @@ int ip6_dst_hoplimit(struct dst_entry *dst) 
	int hoplimit = dst_metric(dst, RTAX_HOPLIMIT);

	if (hoplimit < 0) {

		struct net_device *dev = dst->dev;

		struct inet6_dev *idev = in6_dev_get(dev);

		if (idev) {

		struct inet6_dev *idev;



		rcu_read_lock();

		idev = __in6_dev_get(dev);

		if (idev)

			hoplimit = idev->cnf.hop_limit;

			in6_dev_put(idev);

		} else

		else

			hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit;

		rcu_read_unlock();

	}

	return hoplimit;

}