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>
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 981ff1e..f1395a6 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -325,14 +325,12 @@
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();
}
/*
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index 47975e3..a52d864 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -52,11 +52,9 @@
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);