2018-03-09, 16:06:19 -0500, David Miller wrote:
> From: Sabrina Dubroca <s...@queasysnail.net>
> Date: Fri, 9 Mar 2018 17:43:21 +0100
>
> > diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
> > index f80524396c06..77d0a78cf7d2 100644
> > --- a/include/net/ip_fib.h
> > +++ b/include/net/ip_fib.h
> > @@ -59,6 +59,7 @@ struct fib_nh_exception {
> > int fnhe_genid;
> > __be32 fnhe_daddr;
> > u32 fnhe_pmtu;
> > + bool fnhe_mtu_locked;
> > __be32 fnhe_gw;
> > unsigned long fnhe_expires;
> > struct rtable __rcu *fnhe_rth_input;
> > diff --git a/include/net/route.h b/include/net/route.h
> > index 1eb9ce470e25..729bb5e61e9a 100644
> > --- a/include/net/route.h
> > +++ b/include/net/route.h
> > @@ -64,6 +64,7 @@ struct rtable {
> >
> > /* Miscellaneous cached information */
> > u32 rt_pmtu;
> > + bool rt_mtu_locked;
> >
> > u32 rt_table_id;
> >
>
> Please use a flag bit for this, we've worked hard to shrink these
> datastructures as much as possible.
Oops, sorry.
> I think if you just choose an unused RTCF_* bit (f.e. 0x02000000) for
> the state, you can use that because values propagate into the
> rtable->rt_flags, and do not propagate out. So you should be able to
> use it in this way privately inside the kernel.
What about a bitfield?
- u32 rt_pmtu;
+ u32 rt_mtu_locked:1,
+ rt_pmtu:31;
Since it's going to be private to the kernel, I'd rather not use a
value that's in uapi, especially considering that they're almost all
used (unless we start recycling).
--
Sabrina
