From: Stephen Hemminger <stephen@networkplumber•org>
To: Cong Wang <xiyou.wangcong@gmail•com>
Cc: netdev@vger•kernel.org, "David S. Miller" <davem@davemloft•net>,
"Eric W. Biederman" <ebiederm@xmission•com>,
Eric Dumazet <eric.dumazet@gmail•com>,
Hannes Frederic Sowa <hannes@stressinduktion•org>,
Cong Wang <cwang@twopensource•com>
Subject: Re: [PATCH] net: clear iflink when moving to a new netns
Date: Wed, 12 Feb 2014 08:33:22 -0800 [thread overview]
Message-ID: <20140212083322.1559f441@nehalam.linuxnetplumber.net> (raw)
In-Reply-To: <1392162690-6647-1-git-send-email-xiyou.wangcong@gmail.com>
On Tue, 11 Feb 2014 15:51:28 -0800
Cong Wang <xiyou.wangcong@gmail•com> wrote:
> From: Cong Wang <cwang@twopensource•com>
>
> BZ: https://bugzilla.kernel.org/show_bug.cgi?id=66691
>
> macvlan and vlan both use iflink to identify its lower device,
> however, after such device is moved to the new netns, its iflink
> would become meaningless as ifindex is per netns. So, instead of
> forbid them moving to another netns, just clear this field so that
> it will not be dumped at least.
>
> Cc: David S. Miller <davem@davemloft•net>
> Cc: Eric W. Biederman <ebiederm@xmission•com>
> Cc: Eric Dumazet <eric.dumazet@gmail•com>
> Cc: Hannes Frederic Sowa <hannes@stressinduktion•org>,
> Signed-off-by: Cong Wang <xiyou.wangcong@gmail•com>
> Signed-off-by: Cong Wang <cwang@twopensource•com>
> ---
> net/core/dev.c | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/net/core/dev.c b/net/core/dev.c
> index 4ad1b78..5e88b0c2 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -6608,12 +6608,11 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
> dev_net_set(dev, net);
>
> /* If there is an ifindex conflict assign a new one */
> - if (__dev_get_by_index(net, dev->ifindex)) {
> - int iflink = (dev->iflink == dev->ifindex);
> + if (__dev_get_by_index(net, dev->ifindex))
> dev->ifindex = dev_new_index(net);
> - if (iflink)
> - dev->iflink = dev->ifindex;
> - }
> +
> + /* Old iflink is meaningless in the new namespace */
> + dev->iflink = dev->ifindex;
>
> /* Send a netdev-add uevent to the new namespace */
> kobject_uevent(&dev->dev.kobj, KOBJ_ADD);
This also breaks propogation of state changes from lower device
to upper device. Things like carrier and up/down.
next prev parent reply other threads:[~2014-02-12 16:33 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-11 23:51 [PATCH] net: clear iflink when moving to a new netns Cong Wang
2014-02-11 23:51 ` [PATCH] macvlan: unregister net device when netdev_upper_dev_link() fails Cong Wang
2014-02-13 22:13 ` David Miller
2014-02-11 23:51 ` [PATCH] net: correct error path in rtnl_newlink() Cong Wang
2014-02-13 22:13 ` David Miller
2014-02-12 15:43 ` [PATCH] net: clear iflink when moving to a new netns Nicolas Dichtel
2014-02-13 1:18 ` Cong Wang
2014-02-13 2:00 ` Eric W. Biederman
2014-02-13 22:44 ` Cong Wang
2014-02-12 16:33 ` Stephen Hemminger [this message]
2014-02-13 1:20 ` Cong Wang
2014-02-13 2:01 ` Eric W. Biederman
2014-02-12 23:18 ` Ben Hutchings
2014-02-13 1:34 ` Cong Wang
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