From 1769192a3c50778e03352a3d95faec830d47ba55 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 11 May 2011 18:22:36 +0000
Subject: [PATCH] l2tp: fix potential rcu race

While trying to remove useless synchronize_rcu() calls, I found l2tp is
indeed incorrectly using two of such calls, but also bumps tunnel
refcount after list insertion.

tunnel refcount must be incremented before being made publically visible
by rcu readers.

This fix can be applied to 2.6.35+ and might need a backport for older
kernels, since things were shuffled in commit fd558d186df2c
(l2tp: Split pppol2tp patch into separate l2tp and ppp parts)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
CC: James Chapman <jchapman@katalix.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
Reading git-format-patch failed