From: Dimitris Michailidis <dm@chelsio.com>
Date: Thu, 7 Oct 2010 14:48:38 +0000 (+0000)
Subject: ipv4: Remove leftover rcu_read_unlock calls from __mkroute_output()
X-Git-Tag: v2.6.37-rc1~147^2~192
X-Git-Url: https://bbs.cooldavid.org/git/?a=commitdiff_plain;h=8391d07b80e8da957cd888870e23f8e218438622;p=net-next-2.6.git

ipv4: Remove leftover rcu_read_unlock calls from __mkroute_output()

Commit "fib: RCU conversion of fib_lookup()" removed rcu_read_lock() from
__mkroute_output but left a couple of calls to rcu_read_unlock() in there.
This causes lockdep to complain that the rcu_read_unlock() call in
__ip_route_output_key causes a lock inbalance and quickly crashes the
kernel. The below fixes this for me.

Signed-off-by: Dimitris Michailidis <dm@chelsio.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 7864d0c4896..3888f6ba0a5 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2396,12 +2396,10 @@ static int __mkroute_output(struct rtable **result,
 
 
 	rth = dst_alloc(&ipv4_dst_ops);
-	if (!rth) {
-		rcu_read_unlock();
+	if (!rth)
 		return -ENOBUFS;
-	}
+
 	in_dev_hold(in_dev);
-	rcu_read_unlock();
 	rth->idev = in_dev;
 
 	atomic_set(&rth->dst.__refcnt, 1);