Re: [PATCH] net: ipv6: Remove addresses for failures with strict DAD

[Hannes Frederic Sowa <hannes@stressinduktion.org>]

On Wed, Aug 17, 2016, at 18:08, Mike Manning wrote:
> On 08/17/2016 04:40 PM, Hannes Frederic Sowa wrote:
> > On 17.08.2016 12:28, Mike Manning wrote:
> >> +static void dev_disable_change(struct inet6_dev *idev);
> >>  
> >>  /*
> >>   *	Configured unicast address hash table
> >> @@ -1945,6 +1946,12 @@ lock_errdad:
> >>  
> >>  			pr_info("%s: IPv6 being disabled!\n",
> >>  				ifp->idev->dev->name);
> >> +			spin_unlock_bh(&ifp->lock);
> >> +			addrconf_dad_stop(ifp, 1);
> >> +			rtnl_lock();
> >> +			dev_disable_change(idev);
> >> +			rtnl_unlock();
> >> +			return;
> >>  		}
> >>  	}
> > 
> > You can't take rtnl_lock at that point but must postpone the actions and
> > do that in addrconf_dad_work.
> > 
> > Probably the whole ... else if (idev->cnf.accept_dad > 1 && ...) needs
> > to move there.
> > 
> > Bye,
> > Hannes
> > 
> > 
> 
> Thanks for the prompt review, I will look into making these changes.
> 
> Also these changes caused a build error due to conditional compilation
> without CONFIG_SYSCTL, which is resolved by replacing the call to
> dev_disable_change(idev) by directly calling addrconf_ifdown(idev->dev,
> 0) instead.
> 
> I would appreciate any further comments if the suggested change in
> behavior is not acceptable.

What you describe in the changelog what is happening right now looks
like a bug to me thus your patch made sense to me.

Bye,
Hannes