From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 14 Apr 2010 23:13:29 +0000 (-0700)
Subject: fib: suppress lockdep-RCU false positive in FIB trie.
X-Git-Tag: v2.6.34-rc5~5^2~6
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=4eaa0e3c;p=karo-tx-linux.git

fib: suppress lockdep-RCU false positive in FIB trie.

Followup of commit 634a4b20

Allow tnode_get_child_rcu() to be called either under rcu_read_lock()
protection or with RTNL held.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 59a838795e3e..c98f115fb0fd 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -209,7 +209,9 @@ static inline struct node *tnode_get_child_rcu(struct tnode *tn, unsigned int i)
 {
 	struct node *ret = tnode_get_child(tn, i);
 
-	return rcu_dereference(ret);
+	return rcu_dereference_check(ret,
+				     rcu_read_lock_held() ||
+				     lockdep_rtnl_is_held());
 }
 
 static inline int tnode_child_length(const struct tnode *tn)