[libvirt] LXC: autostart feature does set all interfaces to state up.

[Gao feng]

On 07/10/2013 02:00 PM, Richard Weinberger wrote:

>>
>> Yes,actually libvirt did up the veth devices, that's why only veth2& veth5 are down.
> 
> Where does libvirt up the devices? The debug log does not contain any "ip link set dev XXX up" commands.
> Also in src/util/virnetdevveth.c I'm unable to find such a ip command.
> 

virLXCProcessSetupInterfaceBridged calls virNetDevSetOnline.

>> I need to know why these two devices are down, I believe they were up, your bridge and default-net
>> looks good. So please show me your kernel message (dmesg), maybe it can give us some useful information.
> 
> This time veth4 and 5 are down.
> 
> ---cut---

> [   44.158209] IPv6: ADDRCONF(NETDEV_UP): veth4: link is not ready
> [   44.473317] IPv6: ADDRCONF(NETDEV_CHANGE): veth4: link becomes ready
> [   44.473400] virbr0: topology change detected, propagating
> [   44.473407] virbr0: port 5(veth4) entered forwarding state
> [   44.473423] virbr0: port 5(veth4) entered forwarding state

veth4 were up here

> [   44.566186] device veth5 entered promiscuous mode
> [   44.571234] IPv6: ADDRCONF(NETDEV_UP): veth5: link is not ready
> [   44.571243] virbr0: topology change detected, propagating
> [   44.571250] virbr0: port 6(veth5) entered forwarding state
> [   44.571261] virbr0: port 6(veth5) entered forwarding state
> [   44.902308] IPv6: ADDRCONF(NETDEV_CHANGE): veth5: link becomes ready
> [   45.000580] virbr0: port 5(veth4) entered disabled state

and then it became down.

> [   45.348548] virbr0: port 6(veth5) entered disabled state

So, Some places disable the veth4 and veth5.
I don't know in which case these two devices will be disabled.

I still can't reproduce this problem in my test bed :(
I need more information to analyse why these two device being disabled.

So, can you run kernel with the below debug patch?

diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c
index d45e760..aed319b 100644
--- a/net/bridge/br_stp_if.c
+++ b/net/bridge/br_stp_if.c
@@ -103,7 +103,7 @@ void br_stp_disable_port(struct net_bridge_port *p)
        p->state = BR_STATE_DISABLED;
        p->topology_change_ack = 0;
        p->config_pending = 0;
-
+       dump_stack();
        br_log_state(p);
        br_ifinfo_notify(RTM_NEWLINK, p);

diff --git a/net/core/dev.c b/net/core/dev.c
index faebb39..9b1617b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1368,6 +1368,7 @@ static int dev_close_many(struct list_head *head)

        list_for_each_entry(dev, head, unreg_list) {
                rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
+               dump_stack();
                call_netdevice_notifiers(NETDEV_DOWN, dev);
        }

@@ -4729,8 +4730,10 @@ void __dev_notify_flags(struct net_device *dev, unsigned int old_flags)
        if (changes & IFF_UP) {
                if (dev->flags & IFF_UP)
                        call_netdevice_notifiers(NETDEV_UP, dev);
-               else
+               else {
+                       dump_stack();
                        call_netdevice_notifiers(NETDEV_DOWN, dev);
+               }
        }

        if (dev->flags & IFF_UP &&


Thanks!