On Wed, Jun 8, 2016 at 9:35 PM, David Ahern <[email protected]> wrote:
>
>> On Jun 8, 2016, at 10:01 PM, Eric Dumazet <[email protected]> wrote:
>>
>>> On Wed, Jun 8, 2016 at 8:41 PM, David Ahern <[email protected]>
>>> wrote:
>>>> On 6/8/16 9:29 PM, Eric Dumazet wrote:
>>>>
>>>> In case a qdisc is used on a vrf device, we need to use different
>>>> lockdep classes to avoid false positives.
>>>>
>>>> Fixes: f9eb8aea2a1e ("net_sched: transform qdisc running bit into a
>>>> seqcount")
>>>> Reported-by: David Ahern <[email protected]>
>>>> Signed-off-by: Eric Dumazet <[email protected]>
>>>
>>>
>>> same result with this patch set.
>>
>> Are you stacking multiple vrf devices ?
>
> No. You can also look at ipvlan. It shows the same trace. For me it is 3
> commands that create the vrf, add eth1, run ping.
Okay, lockdep is hard ;)
I will send a v3 after some sleep, adding the following :
(I might have to add a new seqcount api instead of hard coding it)
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index c4f5749342ec..d53ecfc1d60e 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -104,7 +104,11 @@ static inline bool qdisc_run_begin(struct Qdisc *qdisc)
{
if (qdisc_is_running(qdisc))
return false;
- write_seqcount_begin(&qdisc->running);
+ /* Variant of write_seqcount_begin() telling lockdep a trylock
+ * was attempted.
+ */
+ raw_write_seqcount_begin(&qdisc->running);
+ seqcount_acquire(&qdisc->running.dep_map, 0, 1, _RET_IP_);
return true;
}
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index cebea73e70ac..cad810b45e31 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -137,10 +137,10 @@ int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
HARD_TX_UNLOCK(dev, txq);
} else {
- spin_lock_nested(root_lock, SINGLE_DEPTH_NESTING);
+ spin_lock(root_lock);
return qdisc_qlen(q);
}
- spin_lock_nested(root_lock, SINGLE_DEPTH_NESTING);
+ spin_lock(root_lock);
if (dev_xmit_complete(ret)) {
/* Driver sent out skb successfully or skb was consumed */
