From c68f24cc354050415c5ea543cd19ea5424463a2f Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 14 Jun 2010 04:46:20 +0000 Subject: [PATCH] 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: Eric Dumazet Acked-by: YOSHIFUJI Hideaki Signed-off-by: David S. Miller --- net/ipv6/route.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index f7702850d45c..8f2d0400cf8a 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -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; } -- 2.20.1