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

Jiri Pirko
2018-05-16T09:49:12Z

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. …