[PATCH net-next] net/sched: remove return value of unregister_tcf_proto_ops

[PATCH net-next] net/sched: remove return value of unregister_tcf_proto_ops

[Zhengchao Shao]

Return value of unregister_tcf_proto_ops is useless, remove it.

Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
---
 include/net/pkt_cls.h | 2 +-
 net/sched/cls_api.c   | 6 ++----
 2 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index 8cf001aed858..d9d90e6925e1 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -23,7 +23,7 @@ struct tcf_walker {
 };
 
 int register_tcf_proto_ops(struct tcf_proto_ops *ops);
-int unregister_tcf_proto_ops(struct tcf_proto_ops *ops);
+void unregister_tcf_proto_ops(struct tcf_proto_ops *ops);
 
 struct tcf_block_ext_info {
 	enum flow_block_binder_type binder_type;
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 9bb4d3dcc994..fdc9acbd56df 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -194,10 +194,9 @@ EXPORT_SYMBOL(register_tcf_proto_ops);
 
 static struct workqueue_struct *tc_filter_wq;
 
-int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
+void unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
 {
 	struct tcf_proto_ops *t;
-	int rc = -ENOENT;
 
 	/* Wait for outstanding call_rcu()s, if any, from a
 	 * tcf_proto_ops's destroy() handler.
@@ -209,12 +208,11 @@ int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
 	list_for_each_entry(t, &tcf_proto_base, head) {
 		if (t == ops) {
 			list_del(&t->head);
-			rc = 0;
 			break;
 		}
 	}
 	write_unlock(&cls_mod_lock);
-	return rc;
+	return;
 }
 EXPORT_SYMBOL(unregister_tcf_proto_ops);
 
-- 
2.17.1

Re: [PATCH net-next] net/sched: remove return value of unregister_tcf_proto_ops

[Jakub Kicinski]

On Mon, 4 Jul 2022 20:43:22 +0800 Zhengchao Shao wrote:
> Return value of unregister_tcf_proto_ops is useless, remove it.

s/useless/unused/ ?

Should we add a WARN if the ops getting removed can't be found or there
are callers which depend on handling unregistered ops without a warning?

答复: [PATCH net-next] net/sched: remove return value of unregister_tcf_proto_ops

[shaozhengchao]

-----邮件原件-----
发件人: Jakub Kicinski [mailto:kuba@kernel.org] 
发送时间: 2022年7月6日 9:43
收件人: shaozhengchao <shaozhengchao@huawei.com>
抄送: linux-kernel@vger.kernel.org; netdev@vger.kernel.org; jhs@mojatatu.com; xiyou.wangcong@gmail.com; jiri@resnulli.us; davem@davemloft.net; edumazet@google.com; pabeni@redhat.com; weiyongjun (A) <weiyongjun1@huawei.com>; yuehaibing <yuehaibing@huawei.com>
主题: Re: [PATCH net-next] net/sched: remove return value of unregister_tcf_proto_ops

On Mon, 4 Jul 2022 20:43:22 +0800 Zhengchao Shao wrote:
> Return value of unregister_tcf_proto_ops is useless, remove it.

s/useless/unused/ ?

Should we add a WARN if the ops getting removed can't be found or there are callers which depend on handling unregistered ops without a warning?

Hi Jakub Kicinski:
	Thank you for your apply. This patch does just remove the return value and change the function type from int to void. It doesn't remove the function.

Zhengchao Shao

Re: [PATCH net-next] net/sched: remove return value of unregister_tcf_proto_ops

[Jakub Kicinski]

On Wed, 6 Jul 2022 01:52:38 +0000 shaozhengchao wrote:
> 	Thank you for your apply. This patch does just remove the
> return value and change the function type from int to void. It
> doesn't remove the function.

I understand. I'm asking you to replace the word "useless" with
"unused". Additionally I'm asking to consider if instead of returning
an error code the function should print a warning if error has occured.