Re: uevent when moving nic between network namespaces?

[Serge Hallyn <serge.hallyn-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>]

Quoting Eric W. Biederman (ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org):
> I am not currently working on a patch for this, but I will be happy to
> review one. At a quick glance it looks like this could just be as
> simple as calling kobject_uevent at the proper time, but testing and
> reading through the relevant code paths is probably a good idea as there
> always seems to be gotchas in that code.
> 
> Eric

This (the simple fix) works for me, actually.

I do notice the ifdef shouldn't be needed, all the better.

From b436802aa8ae80f699b3d7bcf584d3e86af7355a Mon Sep 17 00:00:00 2001
From: Serge Hallyn <serge.hallyn-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>
Date: Fri, 12 Oct 2012 21:42:05 +0100
Subject: [PATCH 1/1] dev_change_net_namespace: send a KOBJ_REMOVED to
 original netns

Signed-off-by: Serge Hallyn <serge.hallyn-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>
---
 net/core/dev.c |    4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/core/dev.c b/net/core/dev.c
index e2215ee..8062a5a 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6172,6 +6172,10 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
 	dev_uc_flush(dev);
 	dev_mc_flush(dev);
 
+	/* Send a netdev-removed uevent to the old namespace */
+#ifdef CONFIG_HOTPLUG
+	kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);
+#endif
 	/* Actually switch the network namespace */
 	dev_net_set(dev, net);
 
-- 
1.7.9.5