[PATCH net-next] soreuseport: Resolve merge conflict for v4/v6 ordering fix

[Craig Gallek]

From: Craig Gallek <kr...@google.com>

d894ba18d4e4 ("soreuseport: fix ordering for mixed v4/v6 sockets")
was merged as a bug fix to the net tree.  Two conflicting changes
were committed to net-next before the above fix was merged back to
net-next:
ca065d0cf80f ("udp: no longer use SLAB_DESTROY_BY_RCU")
3b24d854cb35 ("tcp/dccp: do not touch listener sk_refcnt under synflood")

These changes switched the datastructure used for TCP and UDP sockets
from hlist_nulls to hlist.  This patch applies the necessary parts
of the net tree fix to net-next which were not automatic as part of the
merge.

Fixes: 1602f49b58ab ("Merge 
git://git.kernel.org/pub/scm/linux/kernel/git/davem/net")
Signed-off-by: Craig Gallek <kr...@google.com>
---
 include/net/sock.h         | 6 +++++-
 net/ipv4/inet_hashtables.c | 6 +++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/include/net/sock.h b/include/net/sock.h
index 52448baf19d7..d6f26b3119aa 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -630,7 +630,11 @@ static inline void sk_add_node(struct sock *sk, struct 
hlist_head *list)
 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
 {
        sock_hold(sk);
-       hlist_add_head_rcu(&sk->sk_node, list);
+       if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
+           sk->sk_family == AF_INET6)
+               hlist_add_tail_rcu(&sk->sk_node, list);
+       else
+               hlist_add_head_rcu(&sk->sk_node, list);
 }
 
 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct 
hlist_nulls_head *list)
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index fcadb670f50b..b76b0d7e59c1 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -479,7 +479,11 @@ int __inet_hash(struct sock *sk, struct sock *osk,
                if (err)
                        goto unlock;
        }
-       hlist_add_head_rcu(&sk->sk_node, &ilb->head);
+       if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
+               sk->sk_family == AF_INET6)
+               hlist_add_tail_rcu(&sk->sk_node, &ilb->head);
+       else
+               hlist_add_head_rcu(&sk->sk_node, &ilb->head);
        sock_set_flag(sk, SOCK_RCU_FREE);
        sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 unlock:
-- 
2.8.0.rc3.226.g39d4020