net: TCP early demux cleanup

early_demux() handlers should be called in RCU context, and as we
use skb_dst_set_noref(skb, dst), caller must not exit from RCU context
before dst use (skb_dst(skb)) or release (skb_drop(dst))

Therefore, rcu_read_lock()/rcu_read_unlock() pairs around
->early_demux() are confusing and not needed :

Protocol handlers are already in an RCU read lock section.
(__netif_receive_skb() does the rcu_read_lock() )

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 2 deletions

diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index 47975e363fcd..a52d864d562b 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -52,11 +52,9 @@ int ip6_rcv_finish(struct sk_buff *skb)
         if (sysctl_ip_early_demux && !skb_dst(skb)) {
                 const struct inet6_protocol *ipprot;
 
-                rcu_read_lock();
                 ipprot = rcu_dereference(inet6_protos[ipv6_hdr(skb)->nexthdr]);
                 if (ipprot && ipprot->early_demux)
                         ipprot->early_demux(skb);
-                rcu_read_unlock();
         }
         if (!skb_dst(skb))
                 ip6_route_input(skb);