Subject: Re: [PATCH 04/14] net: sched: implement unlocked action init API

From: Jiri Pirko <[email-masked]>
Date: Mon, 14 May 2018 17:16:41 +0200

Mon, May 14, 2018 at 04:27:05PM CEST, [email-masked] wrote:
>Add additional 'unlocked' argument to act API init functions.
>Argument is true when rtnl lock is not taken and false otherwise.
>It is required to implement actions that need to release rtnl lock before
>loading kernel module and reacquire if afterwards.
>
>Signed-off-by: Vlad Buslov <[email-masked]>

[...]

>@@ -721,9 +722,11 @@ struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
> 	a_o = tc_lookup_action_n(act_name);
> 	if (a_o == NULL) {
> #ifdef CONFIG_MODULES
>-		rtnl_unlock();
>+		if (!unlocked)
>+			rtnl_unlock();
> 		request_module("act_%s", act_name);
>-		rtnl_lock();
>+		if (!unlocked)
>+			rtnl_lock();

Although I don't like this conditional locking scheme, I see no other
way to solve this :/ But I think would be better perhaps to rename
"unlocked" to something like "rtnl_held".

[...]