From 338d182fa542b3ca05456ad1ce9cebe6580083b1 Mon Sep 17 00:00:00 2001 From: Francesco Ruggeri Date: Wed, 8 Nov 2017 11:23:46 -0800 Subject: [PATCH] ipv6: try not to take rtnl_lock in ip6mr_sk_done Avoid traversing the list of mr6_tables (which requires the rtnl_lock) in ip6mr_sk_done(), when we know in advance that a match will not be found. This can happen when rawv6_close()/ip6mr_sk_done() is invoked on non-mroute6 sockets. This patch helps reduce rtnl_lock contention when destroying a large number of net namespaces, each having a non-mroute6 raw socket. v2: same patch, only fixed subject line and expanded comment. Signed-off-by: Francesco Ruggeri Signed-off-by: David S. Miller --- net/ipv6/ip6mr.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c index 59fad81..9c24b85 100644 --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -1617,6 +1617,10 @@ int ip6mr_sk_done(struct sock *sk) struct net *net = sock_net(sk); struct mr6_table *mrt; + if (sk->sk_type != SOCK_RAW || + inet_sk(sk)->inet_num != IPPROTO_ICMPV6) + return err; + rtnl_lock(); ip6mr_for_each_table(mrt, net) { if (sk == mrt->mroute6_sk) { -- 2.7.4