ACK / APPLIED[artful]: [SRU][Xenial][Yakkety][Zesty][Artful][PATCH 1/1] bonding: avoid NETDEV_CHANGEMTU event when unregistering slave

[Seth Forshee]

On Fri, Jul 14, 2017 at 04:58:52PM -0400, Joseph Salisbury wrote:
> From: WANG Cong <xiyou.wangcong at gmail.com>
> 
> BugLink: http://bugs.launchpad.net/bugs/1704102
> 
> As Hongjun/Nicolas summarized in their original patch:
> 
> "
> When a device changes from one netns to another, it's first unregistered,
> then the netns reference is updated and the dev is registered in the new
> netns. Thus, when a slave moves to another netns, it is first
> unregistered. This triggers a NETDEV_UNREGISTER event which is caught by
> the bonding driver. The driver calls bond_release(), which calls
> dev_set_mtu() and thus triggers NETDEV_CHANGEMTU (the device is still in
> the old netns).
> "
> 
> This is a very special case, because the device is being unregistered
> no one should still care about the NETDEV_CHANGEMTU event triggered
> at this point, we can avoid broadcasting this event on this path,
> and avoid touching inetdev_event()/addrconf_notify() path.
> 
> It requires to export __dev_set_mtu() to bonding driver.
> 
> Reported-by: Hongjun Li <hongjun.li at 6wind.com>
> Reported-by: Nicolas Dichtel <nicolas.dichtel at 6wind.com>
> Cc: Jay Vosburgh <j.vosburgh at gmail.com>
> Cc: Veaceslav Falico <vfalico at gmail.com>
> Cc: Andy Gospodarek <andy at greyhouse.net>
> Signed-off-by: Cong Wang <xiyou.wangcong at gmail.com>
> Signed-off-by: David S. Miller <davem at davemloft.net>
> (cherry picked from commit f51048c3e07b68c90b21a77541fc4b208f9244d7)
> Signed-off-by: Joseph Salisbury <joseph.salisbury at canonical.com>

Acked-by: Seth Forshee <seth.forshee at canonical.com>

Applied to artful/master-next and unstable/master, thanks.