From: Stephen Hemminger <shemminger@vyatta•com>
To: Jiri Pirko <jiri@resnulli•us>
Cc: Flavio Leitner <fbl@redhat•com>,
John Fastabend <john.fastabend@gmail•com>,
netdev@vger•kernel.org, davem@davemloft•net, edumazet@google•com,
bhutchings@solarflare•com, mirqus@gmail•com,
greearb@candelatech•com
Subject: Re: [patch net-next 0/4] net: allow to change carrier from userspace
Date: Fri, 14 Dec 2012 09:23:43 -0800 [thread overview]
Message-ID: <20121214092343.76356a2c@nehalam.linuxnetplumber.net> (raw)
In-Reply-To: <20121214171345.GC1652@minipsycho.brq.redhat.com>
On Fri, 14 Dec 2012 18:13:45 +0100
Jiri Pirko <jiri@resnulli•us> wrote:
> Fri, Dec 14, 2012 at 05:59:18PM CET, shemminger@vyatta•com wrote:
> >On Fri, 14 Dec 2012 17:35:32 +0100
> >Jiri Pirko <jiri@resnulli•us> wrote:
> >
> >> Fri, Dec 14, 2012 at 05:12:01PM CET, shemminger@vyatta•com wrote:
> >> >On Fri, 14 Dec 2012 15:41:34 +0100
> >> >Jiri Pirko <jiri@resnulli•us> wrote:
> >> >
> >> >> Thu, Dec 13, 2012 at 07:20:51PM CET, shemminger@vyatta•com wrote:
> >> >> >On Thu, 13 Dec 2012 16:17:33 -0200
> >> >> >Flavio Leitner <fbl@redhat•com> wrote:
> >> >> >
> >> >> >> On Thu, 13 Dec 2012 10:09:33 -0800
> >> >> >> Stephen Hemminger <shemminger@vyatta•com> wrote:
> >> >> >>
> >> >> >> > On Thu, 13 Dec 2012 15:54:23 -0200
> >> >> >> > Flavio Leitner <fbl@redhat•com> wrote:
> >> >> >> >
> >> >> >> > > I am saying this because people are used to and there are scripts out
> >> >> >> > > there using something like:
> >> >> >> > > # ethtool <iface> | grep 'Link'
> >> >> >> > > to react an interface failure.
> >> >> >> >
> >> >> >> > Then the script is broken. It is asking about hardware state.
> >> >> >>
> >> >> >> I was talking about the team master interface, so it makes sense
> >> >> >> to check its 'hardware' state. Just think on 'bond0' interface
> >> >> >> with no slaves. It should report Link detected: no.
> >> >> >>
> >> >> >> See bond_release(), what happens if bond->slave_cnt == 0, for instance.
> >> >> >>
> >> >> >
> >> >> >I was thinking more that ethtool operation for reporting link on
> >> >> >the team device should use the proper check rather than just using netif_carrier_ok(),
> >> >> >the team ethtool operation for get_link should be check IFF_RUNNING flag
> >> >> >in dev->flags which is controlled by operstate transistions.
> >> >>
> >> >> I admit I'm bit confused now.
> >> >>
> >> >> For example in bridge code:
> >> >> in br_add_if() - netif_carrier_ok() is checked and by the value it is
> >> >> decided if br_stp_enable_port() is called or not. Wouldn't it make more
> >> >> sense to check IFF_RUNNING (or netif_oper_up()) here?
> >> >>
> >> >> The reason I'm asing is that if team device is in bridge, carrier is
> >> >> always ON and I'm fiddling with IF_OPER_UP and IF_OPER_DORMANT from
> >> >> userspace, in current code, bridge wouldn't know the difference...
> >> >>
> >> >> There are more exmaples of similar usage of netif_carrier_ok() in
> >> >> bridge (called on ports), bonding (called on slaves), team code (called on ports).
> >> >
> >> >Yes the bridge should be fixed to work with user controlled devices.
> >>
> >> Okay. I'll try to figure out some patchset over the weekend.
> >>
> >> Thanks.
> >>
> >
> >Something like this seems needed.
> >
> >--- a/net/bridge/br_if.c 2012-10-25 09:11:15.627272524 -0700
> >+++ b/net/bridge/br_if.c 2012-12-14 08:58:14.329847361 -0800
> >@@ -66,14 +66,14 @@ void br_port_carrier_check(struct net_br
> > struct net_device *dev = p->dev;
> > struct net_bridge *br = p->br;
> >
> >- if (netif_running(dev) && netif_carrier_ok(dev))
> >+ if (netif_running(dev) && netif_oper_up(dev))
> > p->path_cost = port_cost(dev);
> >
> > if (!netif_running(br->dev))
> > return;
> >
> > spin_lock_bh(&br->lock);
> >- if (netif_running(dev) && netif_carrier_ok(dev)) {
> >+ if (netif_running(dev) && netif_oper_up(dev))
> > if (p->state == BR_STATE_DISABLED)
> > br_stp_enable_port(p);
> > } else {
> >--- a/net/bridge/br_notify.c 2012-10-25 09:11:15.631272484 -0700
> >+++ b/net/bridge/br_notify.c 2012-12-14 08:57:36.954222724 -0800
> >@@ -82,7 +82,7 @@ static int br_device_event(struct notifi
> > break;
> >
> > case NETDEV_UP:
> >- if (netif_carrier_ok(dev) && (br->dev->flags & IFF_UP)) {
> >+ if (netif_running(br->dev) && netif_oper_up(dev)) {
> > spin_lock_bh(&br->lock);
> > br_stp_enable_port(p);
> > spin_unlock_bh(&br->lock);
>
>
> Yes. I have this already in my queue. I just spotted a problem though.
>
> Lets say teamd sets operstate of the team device by values IF_OPER_UP
> and IF_OPER_DORMANT depending on teamd states of ports.
> What if one would like to use 802.1X supplicant on the same device?
> That would not be possible.
>
> This proves that the layering would not be correct. It look like the
> carrier userspace set would be the correct thing to do after all...
>
> What do you think?
That is tough, you have two applications conflicting over control of
the same state on the same device.
next prev parent reply other threads:[~2012-12-14 17:24 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-12 10:58 [patch net-next 0/4] net: allow to change carrier from userspace Jiri Pirko
2012-12-12 10:58 ` [patch net-next 1/4] net: add change_carrier netdev op Jiri Pirko
2012-12-12 10:58 ` [patch net-next 2/4] net: allow to change carrier via sysfs Jiri Pirko
2012-12-12 10:58 ` [patch net-next 3/4] rtnl: expose carrier value with possibility to set it Jiri Pirko
2012-12-12 10:58 ` [patch net-next 4/4] dummy: implement carrier change Jiri Pirko
2012-12-12 16:15 ` [patch net-next 0/4] net: allow to change carrier from userspace Stephen Hemminger
2012-12-12 17:05 ` Jiri Pirko
2012-12-12 17:27 ` Stephen Hemminger
2012-12-12 18:10 ` Jiri Pirko
2012-12-12 18:12 ` Stephen Hemminger
2012-12-12 18:25 ` Jiri Pirko
2012-12-12 18:36 ` Stephen Hemminger
2012-12-12 18:49 ` Jiri Pirko
2012-12-12 18:54 ` Stephen Hemminger
2012-12-12 19:06 ` Jiri Pirko
2012-12-12 19:34 ` Stephen Hemminger
2012-12-13 16:17 ` Jiri Pirko
2012-12-13 17:15 ` John Fastabend
2012-12-13 17:54 ` Flavio Leitner
2012-12-13 18:09 ` Stephen Hemminger
2012-12-13 18:17 ` Flavio Leitner
2012-12-13 18:20 ` Stephen Hemminger
2012-12-13 18:33 ` Dan Williams
2012-12-13 19:09 ` John Fastabend
2012-12-13 21:32 ` Jiri Pirko
2012-12-14 14:41 ` Jiri Pirko
2012-12-14 16:12 ` Stephen Hemminger
2012-12-14 16:35 ` Jiri Pirko
2012-12-14 16:59 ` Stephen Hemminger
2012-12-14 17:13 ` Jiri Pirko
2012-12-14 17:23 ` Stephen Hemminger [this message]
2012-12-14 17:35 ` Jiri Pirko
2012-12-16 10:54 ` Jiri Pirko
2012-12-18 6:49 ` Stephen Hemminger
2012-12-18 9:31 ` Jiri Pirko
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