Re: [PATCH net-next] devlink: Make devlink_register to be void

From: Jakub Kicinski
Date: Tue Sep 21 2021 - 08:40:10 EST


On Tue, 21 Sep 2021 05:19:06 +0300 Leon Romanovsky wrote:
> On Mon, Sep 20, 2021 at 02:04:07PM -0700, Jakub Kicinski wrote:
> > On Mon, 20 Sep 2021 13:39:15 -0700 Jakub Kicinski wrote:
> > > On Mon, 20 Sep 2021 17:41:44 +0300 Leon Romanovsky wrote:
> [...]
> > >
> > > Unlike unused functions bringing back error handling may be
> > > non-trivial. I'd rather you deferred such cleanups until you're
> > > ready to post your full rework and therefore give us some confidence
> > > the revert will not be needed.
> >
> > If you disagree you gotta repost, new devlink_register call got added
> > in the meantime.
>
> This is exactly what I afraid, new devlink API users are added faster
> than I can cleanup them.
>
> For example, let's take a look on newly added ipc_devlink_init(), it is
> called conditionally "if (stage == IPC_MEM_EXEC_STAGE_BOOT) {". How can
> it be different stage if we are in driver .probe() routine?
>
> They also introduced devlink_sio.devlink_read_pend and
> devlink_sio.read_sem to protect from something that right position of
> devlink_register() will fix. I also have serious doubts that their
> current protection is correct, once they called to devlink_params_publish()
> the user can crash the system, because he can access the parameters before
> they initialized their protection.
>
> So yes, I disagree. We will need to make sure that devlink_register()
> can't fail and it will make life easier for everyone (no need to unwind)
> while we put that command being last in probe sequence.

Remains to be seen if return type makes people follow correct ordering.

> If I repost, will you take it? I don't want to waste anyone time if it
> is not.

Yeah, go for it.