On Mon, Apr 24, 2017 at 01:37:00PM -0600, David Ahern wrote:
> On 4/24/17 10:39 AM, Eric Dumazet wrote:
> >
> > Very nice changelog !
>
>
> Thanks. Given my aggressive brain cell recycling program, I needed to
> write down the analysis.
>
>
>
> >> diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
> >> index 80ce478c4851..93f81d9cd85f 100644
> >> --- a/net/ipv6/addrconf.c
> >> +++ b/net/ipv6/addrconf.c
> >> @@ -3271,14 +3271,25 @@ static void addrconf_gre_config(struct net_device
> >> *dev)
> >> static int fixup_permanent_addr(struct inet6_dev *idev,
> >> struct inet6_ifaddr *ifp)
> >> {
> >> - if (!ifp->rt) {
> >> - struct rt6_info *rt;
> >> + /* rt6i_ref == 0 means the host route was removed from the
> >> + * FIB, for example, if 'lo' device is taken down. In that
> >> + * case regenerate the host route.
> >> + */
> >> + if (!ifp->rt || !atomic_read(&ifp->rt->rt6i_ref)) {
> >> + struct rt6_info *rt, *prev;
> >>
> >> rt = addrconf_dst_alloc(idev, &ifp->addr, false);
> >> if (unlikely(IS_ERR(rt)))
> >> return PTR_ERR(rt);
> >>
> >> + prev = ifp->rt;
> >
> > I would feel more comfortable if this was moved after the spin_lock() ?
>
> That's what I had in v2; it reads better to me even if it is not
> technically required (all changes to ifp->rt happen under rtnl).
>
> Martin you agree?
Agree.
My question was mainly on the added spin_lock.
>
> I'll send a v3 tomorrow -- allow more time for other comments.
