Re: [PATCH 14/14] net: sched: implement delete for all actions

Vlad Buslov
2018-05-16T09:58:59Z

On Wed 16 May 2018 at 09:48, Jiri Pirko <jiri@resnulli.us> wrote:
> Mon, May 14, 2018 at 04:27:15PM CEST, vladbu@mellanox.com wrote:
>>Implement delete function that is required to delete actions without
>>holding rtnl lock. Use action API function that atomically deletes action
>>only if it is still in action idr. This implementation prevents concurrent
>>threads from deleting same action twice.
>>
>>Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
>>---
>> net/sched/act_bpf.c | 8 ++++++++
>> net/sched/act_connmark.c | 8 ++++++++
>> net/sched/act_csum.c | 8 ++++++++
>> net/sched/act_gact.c | 8 ++++++++
>> net/sched/act_ife.c | 8 ++++++++
>> net/sched/act_ipt.c | 16 ++++++++++++++++
>> net/sched/act_mirred.c | 8 ++++++++
>> net/sched/act_nat.c | 8 ++++++++
>> net/sched/act_pedit.c | 8 ++++++++
>> net/sched/act_police.c | 8 ++++++++
>> net/sched/act_sample.c | 8 ++++++++
>> net/sched/act_simple.c | 8 ++++++++
>> net/sched/act_skbedit.c | 8 ++++++++
>> net/sched/act_skbmod.c | 8 ++++++++
>> net/sched/act_tunnel_key.c | 8 ++++++++
>> net/sched/act_vlan.c | 8 ++++++++
>> 16 files changed, 136 insertions(+)
>>
>>diff --git a/net/sched/act_bpf.c b/net/sched/act_bpf.c
>>index 0bf4ecf..36f7f66 100644
>>--- a/net/sched/act_bpf.c
>>+++ b/net/sched/act_bpf.c
>>@@ -394,6 +394,13 @@ static int tcf_bpf_search(struct net *net, struct tc_action **a, u32 index,
>> return tcf_idr_search(tn, a, index);
>> }
>>
>>+static int tcf_bpf_delete(struct net *net, u32 index)
>>+{
>>+ struct tc_action_net *tn = net_generic(net, bpf_net_id);
>>+
>>+ return tcf_idr_find_delete(tn, index);
>>+}
>>+
>> static struct tc_action_ops act_bpf_ops __read_mostly = {
>> .kind = "bpf",
>> .type = TCA_ACT_BPF,
>>@@ -404,6 +411,7 @@ static struct tc_action_ops act_bpf_ops __read_mostly = {
>> .init = tcf_bpf_init,
>> .walk = tcf_bpf_walker,
>> .lookup = tcf_bpf_search,
>>+ .delete = tcf_bpf_delete,
>
> I wonder, right before this patch, how the idr index got removed?
> delete op is NULL and I didn't find anyone else to do it.
>
> Also, after this patch, does it make sense to have following check in
> tcf_action_del_1()?
>
> if (ops->delete)
> err = ops->delete(net, index);
>
> Looks like ops->delete is non-null for all.
>
> Seems to me that you need to introduce this patch filling up the delete
> op in all acts and only after that introduce a code that actually calls
> it.

Already moved this for V2 patchset to:
- Add delete callback to ops and implement it for all actions in single
patch.
- Move this patch before delete first use.

Will now remove the conditional as well.

>
> …