netdev - [PATCH net-next] net/ipv6: prefer rcu_access_pointer() over rcu

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Message-Id: <52d4aee68b816ce36c0d4f4398ae143a2ebbdba4.1550249827.git.pabeni@redhat.com>
Date:   Fri, 15 Feb 2019 18:15:37 +0100
From:   Paolo Abeni <pabeni@...hat.com>
To:     netdev@...r.kernel.org
Cc:     "David S. Miller" <davem@...emloft.net>,
        David Ahern <dsahern@...il.com>
Subject: [PATCH net-next] net/ipv6: prefer rcu_access_pointer() over rcu_dereference()

rt6_cache_allowed_for_pmtu() checks for rt->from presence, but
it does not access the RCU protected pointer. We can use
rcu_access_pointer() and clean-up the code a bit. No functional
changes intended.

Signed-off-by: Paolo Abeni <pabeni@...hat.com>
---
 net/ipv6/route.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index dc066fdf7e46..87a0561136dd 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2277,14 +2277,8 @@ static void rt6_do_update_pmtu(struct rt6_info *rt, u32 mtu)
 
 static bool rt6_cache_allowed_for_pmtu(const struct rt6_info *rt)
 {
-	bool from_set;
-
-	rcu_read_lock();
-	from_set = !!rcu_dereference(rt->from);
-	rcu_read_unlock();
-
 	return !(rt->rt6i_flags & RTF_CACHE) &&
-		(rt->rt6i_flags & RTF_PCPU || from_set);
+		(rt->rt6i_flags & RTF_PCPU || rcu_access_pointer(rt->from));
 }
 
 static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,
-- 
2.20.1