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Message-ID: <CAGVrzcYvmr+5Tv5ioU16pWFeV-MT2CqOCytfDeYqgsOMWOdftg@mail.gmail.com> Date: Sat, 21 Feb 2015 12:26:24 -0800 From: Florian Fainelli <f.fainelli@...il.com> To: Scott Feldman <sfeldma@...il.com> Cc: Jiri Pirko <jiri@...nulli.us>, netdev <netdev@...r.kernel.org>, Stephen Hemminger <stephen@...workplumber.org> Subject: Re: Port STP state after removing port from bridge 2015-02-21 11:43 GMT-08:00 Scott Feldman <sfeldma@...il.com>: > On Fri, Feb 20, 2015 at 9:04 AM, Florian Fainelli <f.fainelli@...il.com> wrote: >> On 20/02/15 07:03, Scott Feldman wrote: >>> On Fri, Feb 20, 2015 at 2:00 AM, Jiri Pirko <jiri@...nulli.us> wrote: >>>> Fri, Feb 20, 2015 at 05:45:01AM CET, sfeldma@...il.com wrote: >>>>> On Wed, Feb 18, 2015 at 11:39 PM, Florian Fainelli <f.fainelli@...il.com> >>>>> wrote: >>>>> >>>>>> Hi, >>>>>> >>>>>> It just occured to me that the following sequence: >>>>>> >>>>>> brctl addbr br0 >>>>>> brctl addif br0 port0 >>>>>> ... STP happens >>>>>> brctl delif br0 port0 >>>>>> >>>>>> will leave port0 in STP disabled state, because the bridge code will >>>>>> set the STP state to DISABLED, and only a down/up sequence can bring >>>>>> it back to FORWARDING. >>>>>> >>>>>> Is this something that we should somehow fix? As an user it seems a >>>>>> little convoluted having to do a down/up sequence to restore things. I >>>>>> believe however that it is valid for the bridge layer to mark a port >>>>>> as DISABLED when removing it. This is typically not noticed or even >>>>>> remotely a problem with software bridges because we cannot enforce an >>>>>> actual STP state at the HW level. >>>>>> >>>>>> Let me know your thoughts. >>>>>> >>>>>> >>>>> The fix in rocker would be: >>>>> >>>>> diff --git a/drivers/net/ethernet/rocker/rocker.c >>>>> b/drivers/net/ethernet/rocker/rocker.c >>>>> index 34389b6a..e2004fb 100644 >>>>> --- a/drivers/net/ethernet/rocker/rocker.c >>>>> +++ b/drivers/net/ethernet/rocker/rocker.c >>>>> @@ -4456,8 +4456,10 @@ static int rocker_port_bridge_leave(struct >>>>> rocker_port *rocker_port) >>>>> rocker_port_internal_vlan_id_get(rocker_port, >>>>> rocker_port->dev->ifindex); >>>>> err = rocker_port_vlan(rocker_port, 0, 0); >>>>> + if (err) >>>>> + return err; >>>>> >>>>> - return err; >>>>> + return rocker_port_stp_update(rocker_port, BR_STATE_FORWARDING); >>>>> } >>>>> >>>>> >>>>> This will return the port back to it's initial state of >>>>> BR_STATE_FORWARDING, after it's removed from the bridge. >>>>> >>>>> I'll include this patch in the rocker pile to be pushed later. >>>>> >>>>> -scott >>>> >>>> >>>> I'm not sure, but wouldn't it be nicer it the bridge code would set >>>> state to disabled before the port is removed from the bridge? >>> >>> When the port is removed from a bridge, for example with brctl delif, >>> the bridge driver puts port in BR_STATE_DISABLED and then sends >>> netdevice event NETDEV_CHANGEUPPER. In response to >>> NETDEV_CHANGEUPPER, the rocker driver is returning port back to >>> BR_STATE_FORWARDING (the initial state for an un-bridged port). So >>> this preserves bridge behavior for non-switchdev uses. Does this >>> answer the question, or did I miss understand your question? >> >> I think what we want is a solution at the bridge level, we have rocker >> now updating the STP state to BR_STATE_FORWARDING when a given >> rocker_port leaves a bridge, and I also had a similar change in DSA. >> >> Something like this maybe (untested): >> >> diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c >> index b087d278c679..d693a2a10b3c 100644 >> --- a/net/bridge/br_if.c >> +++ b/net/bridge/br_if.c >> @@ -242,6 +242,8 @@ static void del_nbp(struct net_bridge_port *p) >> >> spin_lock_bh(&br->lock); >> br_stp_disable_port(p); >> + if (dev->features & NETIF_F_HW_SWITCH_OFFLOAD) >> + br_set_state(p, BR_STATE_FORWARDING); >> spin_unlock_bh(&br->lock); >> >> br_ifinfo_notify(RTM_DELLINK, p); > > Acked-by: Scott Feldman <sfeldma@...il.com> > > I like it. I tested your version with rocker and it works great. (I > removed my version). Would you push this one when things open up? Ok, thanks for testing! -- Florian -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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