Re: [PATCH RESEND v2 net-next 13/14] ipv6: Protect nh->f6i_list with spinlock and flag.

[Kuniyuki Iwashima <kuniyu@amazon.com>]

From: Paolo Abeni <pabeni@redhat.com>
Date: Wed, 16 Apr 2025 17:17:13 +0200
> On 4/14/25 8:15 PM, Kuniyuki Iwashima wrote:
> > @@ -1498,7 +1504,23 @@ int fib6_add(struct fib6_node *root, struct fib6_info *rt,
> >  	}
> >  #endif
> >  
> > -	err = fib6_add_rt2node(fn, rt, info, extack, &purge_list);
> > +	if (rt->nh) {
> > +		spin_lock(&rt->nh->lock);
> > +
> > +		if (rt->nh->dead) {
> > +			NL_SET_ERR_MSG(extack, "Nexthop has been deleted");
> > +			err = -EINVAL;
> > +		} else {
> > +			err = fib6_add_rt2node(fn, rt, info, extack, &purge_list);
> > +			if (!err)
> > +				list_add(&rt->nh_list, &rt->nh->f6i_list);
> > +		}
> 
> Maybe move the new check and list_add inside fib6_add_rt2node() or
> bundle all the above in a new helper?

fib6_add_rt2node() has return in many places, so a new hepler makes
more sense to me.

Will add fib6_add_rt2node_nh() and move spin_lock() section there.