From 18c22a03a2187bcbda7d3a7fa1061584a6348e7b Mon Sep 17 00:00:00 2001
From: Jiri Pirko <jiri@resnulli.us>
Date: Wed, 17 Oct 2012 01:37:36 +0000
Subject: [PATCH] vlan: allow to change type when no vlan device is hooked on
 netdev

vlan_info might be present but still no vlan devices might be there.
That is in case of vlan0 automatically added.

So in that case, allow to change netdev type.

Reported-by: Jon Stanley <jstanley@rmrf.net>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/8021q/vlan.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
index 9096bcb081326..ee070722a3a36 100644
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -463,7 +463,9 @@ static int vlan_device_event(struct notifier_block *unused, unsigned long event,
 
 	case NETDEV_PRE_TYPE_CHANGE:
 		/* Forbid underlaying device to change its type. */
-		return NOTIFY_BAD;
+		if (vlan_uses_dev(dev))
+			return NOTIFY_BAD;
+		break;
 
 	case NETDEV_NOTIFY_PEERS:
 	case NETDEV_BONDING_FAILOVER:
-- 
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