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/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 981ff1eef28c..f1395a6fb35f 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -325,14 +325,12 @@ static int ip_rcv_finish(struct sk_buff *skb)
                 const struct net_protocol *ipprot;
                 int protocol = iph->protocol;
 
-                rcu_read_lock();
                 ipprot = rcu_dereference(inet_protos[protocol]);
                 if (ipprot && ipprot->early_demux) {
                         ipprot->early_demux(skb);
                         /* must reload iph, skb->head might have changed */
                         iph = ip_hdr(skb);
                 }
-                rcu_read_unlock();
         }
 
         /*