ipv6: reorder ip6_route_dev_notifier after ipv6_dev_notf

BugLink: http://bugs.launchpad.net/bugs/1691418
[ Upstream commit 242d3a49a2a1a71d8eb9f953db1bcaa9d698ce00 ]

For each netns (except init_net), we initialize its null entry
in 3 places:

1) The template itself, as we use kmemdup()
2) Code around dst_init_metrics() in ip6_route_net_init()
3) ip6_route_dev_notify(), which is supposed to initialize it after
   loopback registers

Unfortunately the last one still happens in a wrong order because
we expect to initialize net->ipv6.ip6_null_entry->rt6i_idev to
net->loopback_dev's idev, thus we have to do that after we add
idev to loopback. However, this notifier has priority == 0 same as
ipv6_dev_notf, and ipv6_dev_notf is registered after
ip6_route_dev_notifier so it is called actually after
ip6_route_dev_notifier. This is similar to commit 2f460933f58e
("ipv6: initialize route null entry in addrconf_init()") which
fixes init_net.

Fix it by picking a smaller priority for ip6_route_dev_notifier.
Also, we have to release the refcnt accordingly when unregistering
loopback_dev because device exit functions are called before subsys
exit functions.

Acked-by: David Ahern <dsahern@gmail.com>
Tested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

diff --git a/include/net/addrconf.h b/include/net/addrconf.h
index 78003dfb8539bd42f75f8c2d04cbb7dce872e1bf..18dd7a3caf2ffd4b296e67a9255ce91ddb82b631 100644 (file)
--- a/include/net/addrconf.h
+++ b/include/net/addrconf.h
@@ -19,6 +19,8 @@
 #define ADDRCONF_TIMER_FUZZ            (HZ / 4)
 #define ADDRCONF_TIMER_FUZZ_MAX                (HZ)
 
+#define ADDRCONF_NOTIFY_PRIORITY       0
+
 #include <linux/in.h>
 #include <linux/in6.h>
 

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index bb747b6cb24193913bd04994e2ca303945273d11..7090fef372cca1c261652fd4bc1104f03e37831e 100644 (file)
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -3306,6 +3306,7 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event,
  */
 static struct notifier_block ipv6_dev_notf = {
        .notifier_call = addrconf_notify,
+       .priority = ADDRCONF_NOTIFY_PRIORITY,
 };
 
 static void addrconf_type_change(struct net_device *dev, unsigned long event)

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 9029b38954e13e0cbf022eaa3bf2d8f6aa13edc9..8f4177a1d4f53280f0ff8177d5d8f61f238bb00e 100644 (file)
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -3363,7 +3363,10 @@ static int ip6_route_dev_notify(struct notifier_block *this,
        struct net_device *dev = netdev_notifier_info_to_dev(ptr);
        struct net *net = dev_net(dev);
 
-       if (event == NETDEV_REGISTER && (dev->flags & IFF_LOOPBACK)) {
+       if (!(dev->flags & IFF_LOOPBACK))
+               return NOTIFY_OK;
+
+       if (event == NETDEV_REGISTER) {
                net->ipv6.ip6_null_entry->dst.dev = dev;
                net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev);
 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
@@ -3371,6 +3374,12 @@ static int ip6_route_dev_notify(struct notifier_block *this,
                net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev);
                net->ipv6.ip6_blk_hole_entry->dst.dev = dev;
                net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev);
+#endif
+        } else if (event == NETDEV_UNREGISTER) {
+               in6_dev_put(net->ipv6.ip6_null_entry->rt6i_idev);
+#ifdef CONFIG_IPV6_MULTIPLE_TABLES
+               in6_dev_put(net->ipv6.ip6_prohibit_entry->rt6i_idev);
+               in6_dev_put(net->ipv6.ip6_blk_hole_entry->rt6i_idev);
 #endif
        }
 
@@ -3678,7 +3687,7 @@ static struct pernet_operations ip6_route_net_late_ops = {
 
 static struct notifier_block ip6_route_dev_notifier = {
        .notifier_call = ip6_route_dev_notify,
-       .priority = 0,
+       .priority = ADDRCONF_NOTIFY_PRIORITY - 10,
 };
 
 void __init ip6_route_init_special_entries(void)