From: Ido Schimmel <idosch@mellanox.com>
Date: Sun, 7 Jan 2018 10:45:01 +0000 (+0200)
Subject: ipv6: Remove redundant route flushing during namespace dismantle
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=9fcb0714dc38250d3b56d28c0b5a0bde0d2a59f2;p=linux.git

ipv6: Remove redundant route flushing during namespace dismantle

By the time fib6_net_exit() is executed all the netdevs in the namespace
have been either unregistered or pushed back to the default namespace.
That is because pernet subsys operations are always ordered before
pernet device operations and therefore invoked after them during
namespace dismantle.

Thus, all the routing tables in the namespace are empty by the time
fib6_net_exit() is invoked and the call to rt6_ifdown() can be removed.

This allows us to simplify the condition in fib6_ifdown() as it's only
ever called with an actual netdev.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index a64d559fa5137..3bbb89d8187d2 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -2103,7 +2103,6 @@ static void fib6_net_exit(struct net *net)
 {
 	unsigned int i;
 
-	rt6_ifdown(net, NULL);
 	del_timer_sync(&net->ipv6.ip6_fib_timer);
 
 	for (i = 0; i < FIB6_TABLE_HASHSZ; i++) {
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 2490280b33942..c557362daa23e 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -3470,10 +3470,9 @@ static int fib6_ifdown(struct rt6_info *rt, void *arg)
 	const struct arg_dev_net *adn = arg;
 	const struct net_device *dev = adn->dev;
 
-	if ((rt->dst.dev == dev || !dev) &&
+	if (rt->dst.dev == dev &&
 	    rt != adn->net->ipv6.ip6_null_entry &&
-	    (rt->rt6i_nsiblings == 0 ||
-	     (dev && netdev_unregistering(dev)) ||
+	    (rt->rt6i_nsiblings == 0 || netdev_unregistering(dev) ||
 	     !rt->rt6i_idev->cnf.ignore_routes_with_linkdown))
 		return -1;
 
@@ -3488,8 +3487,7 @@ void rt6_ifdown(struct net *net, struct net_device *dev)
 	};
 
 	fib6_clean_all(net, fib6_ifdown, &adn);
-	if (dev)
-		rt6_uncached_list_flush_dev(net, dev);
+	rt6_uncached_list_flush_dev(net, dev);
 }
 
 struct rt6_mtu_change_arg {