commit fdd6681d92a70b3db73cdb61c6b4053f2f8003b3
author Amerigo Wang <amwang@redhat.com> Mon Sep 10 02:48:44 2012 +0000
committer David S. Miller <davem@davemloft.net> Mon Sep 10 16:31:18 2012 -0400
tree 15a050d4fd0ffd4082fefcd9d2ad454b0c06218f
parent 6d57e9078e880a3dd232d579f42ac437a8f1ef7b

ipv6: remove some useless RCU read lock

After this commit:
	commit 97cac0821af4474ec4ba3a9e7a36b98ed9b6db88
	Author: David S. Miller <davem@davemloft.net>
	Date:   Mon Jul 2 22:43:47 2012 -0700

	    ipv6: Store route neighbour in rt6_info struct.

we no longer use RCU to protect route neighbour.

Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/route.c

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index a81c679..399613b 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -451,10 +451,9 @@
 	 * Router Reachability Probe MUST be rate-limited
 	 * to no more than one per minute.
 	 */
-	rcu_read_lock();
 	neigh = rt ? rt->n : NULL;
 	if (!neigh || (neigh->nud_state & NUD_VALID))
-		goto out;
+		return;
 	read_lock_bh(&neigh->lock);
 	if (!(neigh->nud_state & NUD_VALID) &&
 	    time_after(jiffies, neigh->updated + rt->rt6i_idev->cnf.rtr_probe_interval)) {
@@ -470,8 +469,6 @@
 	} else {
 		read_unlock_bh(&neigh->lock);
 	}
-out:
-	rcu_read_unlock();
 }
 #else
 static inline void rt6_probe(struct rt6_info *rt)
@@ -498,7 +495,6 @@
 	struct neighbour *neigh;
 	int m;
 
-	rcu_read_lock();
 	neigh = rt->n;
 	if (rt->rt6i_flags & RTF_NONEXTHOP ||
 	    !(rt->rt6i_flags & RTF_GATEWAY))
@@ -516,7 +512,6 @@
 		read_unlock_bh(&neigh->lock);
 	} else
 		m = 0;
-	rcu_read_unlock();
 	return m;
 }
 
@@ -2496,15 +2491,11 @@
 	if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
 		goto nla_put_failure;
 
-	rcu_read_lock();
 	n = rt->n;
 	if (n) {
-		if (nla_put(skb, RTA_GATEWAY, 16, &n->primary_key) < 0) {
-			rcu_read_unlock();
+		if (nla_put(skb, RTA_GATEWAY, 16, &n->primary_key) < 0)
 			goto nla_put_failure;
-		}
 	}
-	rcu_read_unlock();
 
 	if (rt->dst.dev &&
 	    nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
@@ -2706,14 +2697,12 @@
 #else
 	seq_puts(m, "00000000000000000000000000000000 00 ");
 #endif
-	rcu_read_lock();
 	n = rt->n;
 	if (n) {
 		seq_printf(m, "%pi6", n->primary_key);
 	} else {
 		seq_puts(m, "00000000000000000000000000000000");
 	}
-	rcu_read_unlock();
 	seq_printf(m, " %08x %08x %08x %08x %8s\n",
 		   rt->rt6i_metric, atomic_read(&rt->dst.__refcnt),
 		   rt->dst.__use, rt->rt6i_flags,