From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: [PATCH 15/16] ipv4: Calling ->cow_metrics() now is a bug. Date: Tue, 10 Jul 2012 08:07:55 -0700 (PDT) Message-ID: <20120710.080755.834084229701598192.davem@davemloft.net> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit To: netdev@vger.kernel.org Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:38429 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754962Ab2GJPHz (ORCPT ); Tue, 10 Jul 2012 11:07:55 -0400 Received: from localhost (74-93-104-98-Washington.hfc.comcastbusiness.net [74.93.104.98]) by shards.monkeyblade.net (Postfix) with ESMTPSA id 63E45586620 for ; Tue, 10 Jul 2012 08:07:57 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: Nothing every writes to ipv4 metrics any longer. PMTU is stored in rt->rt_pmtu. Dynamic TCP metrics are stored in a special TCP metrics cache, completely outside of the routes. Therefore ->cow_metrics() can simply nothing more than a WARN_ON trigger so we can catch anyone who tries to add new writes to ipv4 route metrics. Signed-off-by: David S. Miller --- net/ipv4/route.c | 30 ++---------------------------- 1 file changed, 2 insertions(+), 28 deletions(-) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index a967df5..9cc00f8 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -158,34 +158,8 @@ static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev, static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) { - struct rtable *rt = (struct rtable *) dst; - struct inet_peer *peer; - u32 *p = NULL; - - peer = rt_get_peer_create(rt, rt->rt_dst); - if (peer) { - u32 *old_p = __DST_METRICS_PTR(old); - unsigned long prev, new; - - p = peer->metrics; - if (inet_metrics_new(peer)) - memcpy(p, old_p, sizeof(u32) * RTAX_MAX); - - new = (unsigned long) p; - prev = cmpxchg(&dst->_metrics, old, new); - - if (prev != old) { - p = __DST_METRICS_PTR(prev); - if (prev & DST_METRICS_READ_ONLY) - p = NULL; - } else { - if (rt->fi) { - fib_info_put(rt->fi); - rt->fi = NULL; - } - } - } - return p; + WARN_ON(1); + return NULL; } static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, -- 1.7.10.4