On 01/06/17 17:16, Nikolay Aleksandrov wrote:
> On 01/06/17 17:00, Nikolay Aleksandrov wrote:
>> On 01/06/17 15:34, Sebastian Ott wrote:
>>> On Thu, 1 Jun 2017, Xin Long wrote:
>>>> On Thu, Jun 1, 2017 at 12:32 AM, Sebastian Ott
>>>> <seb...@linux.vnet.ibm.com> wrote:
>>>>> [...]
>>>> I couldn't see any bridge-related thing here, and it couldn't be reproduced
>>>> with virbr0 (stp=1) on my box (on both s390x and x86_64), I guess there
>>>> is something else in you machine.
>>>>
>>>> With the latest upstream kernel, can you remove libvirt (virbr0) and boot
>>>> your
>>>> machine normally, then:
>>>> # brctl addbr br0
>>>> # ip link set br0 up
>>>> # brctl stp br0 on
>>>>
>>>> to check if it will still hang.
>>>
>>> Nope. That doesn't hang.
>>>
>>>
>>>> If it can't be reproduced in this way, pls add this on your kernel:
>>>>
>>>> --- a/net/bridge/br_stp_if.c
>>>> +++ b/net/bridge/br_stp_if.c
>>>> @@ -178,9 +178,11 @@ static void br_stp_start(struct net_bridge *br)
>>>> br->stp_enabled = BR_KERNEL_STP;
>>>> br_debug(br, "using kernel STP\n");
>>>>
>>>> + WARN_ON(1);
>>>> /* To start timers on any ports left in blocking */
>>>> mod_timer(&br->hello_timer, jiffies + br->hello_time);
>>>> br_port_state_selection(br);
>>>> + pr_warn("hello timer start done\n");
>>>> }
>>>>
>>>> spin_unlock_bh(&br->lock);
>>>> diff --git a/net/bridge/br_stp_timer.c b/net/bridge/br_stp_timer.c
>>>> index 60b6fe2..c98b3e5 100644
>>>> --- a/net/bridge/br_stp_timer.c
>>>> +++ b/net/bridge/br_stp_timer.c
>>>> @@ -40,7 +40,7 @@ static void br_hello_timer_expired(unsigned long arg)
>>>> if (br->dev->flags & IFF_UP) {
>>>> br_config_bpdu_generation(br);
>>>>
>>>> - if (br->stp_enabled == BR_KERNEL_STP)
>>>> + if (br->stp_enabled != BR_USER_STP)
>>>> mod_timer(&br->hello_timer,
>>>> round_jiffies(jiffies + br->hello_time));
>>>>
>>>>
>>>> let's see if it hangs when starting the timer. Thanks.
>>>
>>> No hang either:
>>>
>> [snip]
>> Could you please try the patch below ?
>>
>> ---
>>
>> diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c
>> index 4efd5d54498a..89110319ef0f 100644
>> --- a/net/bridge/br_stp_if.c
>> +++ b/net/bridge/br_stp_if.c
>> @@ -173,7 +173,8 @@ static void br_stp_start(struct net_bridge *br)
>> br_debug(br, "using kernel STP\n");
>>
>> /* To start timers on any ports left in blocking */
>> - mod_timer(&br->hello_timer, jiffies + br->hello_time);
>> + if (br->dev->flags & IFF_UP)
>> + mod_timer(&br->hello_timer, jiffies + br->hello_time);
>> br_port_state_selection(br);
>> }
>>
>>
>
> Ah nevermind, this patch reverts it back to the previous state.
>
Okay, I saw the problem and can reliably reproduce it. I will send a fix for
testing
in a few minutes. I think the issue is that the timer can be started before the
bridge
even goes up, i.e. create bridge -> brctl stp br0 on -> ip l del br0
so the del_timer_sync() doesn't get executed and thus it's still armed.
$ while :; do ip l add br0 type bridge hello_time 100; brctl stp br0 on; ip l
del br0; done;
