commit 0c5794a66c7c6443759e6098841767958a031187
author stephen hemminger <shemminger@vyatta.com> Mon Sep 24 18:12:24 2012 +0000
committer David S. Miller <davem@davemloft.net> Thu Sep 27 18:12:37 2012 -0400
tree bc5206b2ce2fa58fc47f6d94fabc7c1bb9fa6f78
parent d208328765a0ab425e36b5b828285f3337a85451

gre: remove unnecessary rcu_read_lock/unlock

The gre function pointers for receive and error handling are
always called (from gre.c) with rcu_read_lock already held.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/ip_gre.c

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 0d4c383..1c012cb 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -557,37 +557,34 @@
 		break;
 	}
 
-	rcu_read_lock();
 	t = ipgre_tunnel_lookup(skb->dev, iph->daddr, iph->saddr,
 				flags, key, p[1]);
 
 	if (t == NULL)
-		goto out;
+		return;
 
 	if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
 		ipv4_update_pmtu(skb, dev_net(skb->dev), info,
 				 t->parms.link, 0, IPPROTO_GRE, 0);
-		goto out;
+		return;
 	}
 	if (type == ICMP_REDIRECT) {
 		ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0,
 			      IPPROTO_GRE, 0);
-		goto out;
+		return;
 	}
 	if (t->parms.iph.daddr == 0 ||
 	    ipv4_is_multicast(t->parms.iph.daddr))
-		goto out;
+		return;
 
 	if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
-		goto out;
+		return;
 
 	if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
 		t->err_count++;
 	else
 		t->err_count = 1;
 	t->err_time = jiffies;
-out:
-	rcu_read_unlock();
 }
 
 static inline void ipgre_ecn_decapsulate(const struct iphdr *iph, struct sk_buff *skb)
@@ -625,7 +622,7 @@
 	__be16 gre_proto;
 
 	if (!pskb_may_pull(skb, 16))
-		goto drop_nolock;
+		goto drop;
 
 	iph = ip_hdr(skb);
 	h = skb->data;
@@ -636,7 +633,7 @@
 		   - We do not support routing headers.
 		 */
 		if (flags&(GRE_VERSION|GRE_ROUTING))
-			goto drop_nolock;
+			goto drop;
 
 		if (flags&GRE_CSUM) {
 			switch (skb->ip_summed) {
@@ -664,7 +661,6 @@
 
 	gre_proto = *(__be16 *)(h + 2);
 
-	rcu_read_lock();
 	tunnel = ipgre_tunnel_lookup(skb->dev,
 				     iph->saddr, iph->daddr, flags, key,
 				     gre_proto);
@@ -740,14 +736,11 @@
 
 		netif_rx(skb);
 
-		rcu_read_unlock();
 		return 0;
 	}
 	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
 
 drop:
-	rcu_read_unlock();
-drop_nolock:
 	kfree_skb(skb);
 	return 0;
 }