[ 3.5.y.z extended stable ] Patch "ipv6: don't call addrconf_dst_alloc again when enable lo" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    ipv6: don't call addrconf_dst_alloc again when enable lo

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 108fd11b5810b93ab1c4c3dfcf081f481f3da243 Mon Sep 17 00:00:00 2001
From: Gao feng <gaofeng at cn.fujitsu.com>
Date: Sun, 16 Jun 2013 11:14:30 +0800
Subject: [PATCH] ipv6: don't call addrconf_dst_alloc again when enable lo

commit a881ae1f625c599b460cc8f8a7fcb1c438f699ad upstream.

If we disable all of the net interfaces, and enable
un-lo interface before lo interface, we already allocated
the addrconf dst in ipv6_add_addr. So we shouldn't allocate
it again when we enable lo interface.

Otherwise the message below will be triggered.
unregister_netdevice: waiting for sit1 to become free. Usage count = 1

This problem is introduced by commit 25fb6ca4ed9cad72f14f61629b68dc03c0d9713f
"net IPv6 : Fix broken IPv6 routing table after loopback down-up"

Signed-off-by: Gao feng <gaofeng at cn.fujitsu.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/ipv6/addrconf.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 449df3f..c126b0a 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -2432,6 +2432,9 @@ static void init_loopback(struct net_device *dev)
 			if (sp_ifa->flags & (IFA_F_DADFAILED | IFA_F_TENTATIVE))
 				continue;

+			if (sp_ifa->rt)
+				continue;
+
 			sp_rt = addrconf_dst_alloc(idev, &sp_ifa->addr, 0);

 			/* Failure cases are ignored */
--
1.8.1.2