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? I'll send a v3 tomorrow -- allow more time for other comments.