On Wed 12 Jun 2019 at 19:33, Daniel Borkmann <dan...@iogearbox.net> wrote:
> On 06/12/2019 09:14 AM, Vlad Buslov wrote:
>> To remove rtnl lock dependency in tc filter update API when using ingress
>> Qdisc, set QDISC_CLASS_OPS_DOIT_UNLOCKED flag in ingress Qdisc_class_ops.
>>
>> Ingress Qdisc ops don't require any modifications to be used without rtnl
>> lock on tc filter update path. Ingress implementation never changes its
>> q->block and only releases it when Qdisc is being destroyed. This means it
>> is enough for RTM_{NEWTFILTER|DELTFILTER|GETTFILTER} message handlers to
>> hold ingress Qdisc reference while using it without relying on rtnl lock
>> protection. Unlocked Qdisc ops support is already implemented in filter
>> update path by unlocked cls API patch set.
>>
>> Signed-off-by: Vlad Buslov <vla...@mellanox.com>
>> ---
>> net/sched/sch_ingress.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/net/sched/sch_ingress.c b/net/sched/sch_ingress.c
>> index 0f65f617756b..d5382554e281 100644
>> --- a/net/sched/sch_ingress.c
>> +++ b/net/sched/sch_ingress.c
>> @@ -114,6 +114,7 @@ static int ingress_dump(struct Qdisc *sch, struct
>> sk_buff *skb)
>> }
>>
>> static const struct Qdisc_class_ops ingress_class_ops = {
>> + .flags = QDISC_CLASS_OPS_DOIT_UNLOCKED,
>> .leaf = ingress_leaf,
>> .find = ingress_find,
>> .walk = ingress_walk,
>>
>
> Vlad, why is clsact_class_ops not updated here? Please elaborate!
Daniel, no particular reason to not enable unlocked execution for
clsact. I set the unlocked flag for ingress because that was the Qdisc
that I tested all my parallel tc changes on. However, ingress and clsact
implementations are quite similar, so I can send a followup patch that
updates clsact_class_ops, if you want.
