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

From: Jiri Pirko
Date: Mon May 14 2018 - 11:16:54 EST

Mon, May 14, 2018 at 04:27:05PM CEST, vladbu@xxxxxxxxxxxx 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 <vladbu@xxxxxxxxxxxx>


>@@ -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) {
>- 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".