Re: [PATCH net-next 7/9] devlink: allow registering parameters after the instance

[Jiri Pirko <jiri@resnulli.us>]

Fri, Jan 06, 2023 at 07:34:00AM CET, kuba@kernel.org wrote:
>It's most natural to register the instance first and then its
>subobjects. Now that we can use the instance lock to protect
>the atomicity of all init - it should also be safe.
>
>Signed-off-by: Jakub Kicinski <kuba@kernel.org>
>---
> net/devlink/leftover.c | 22 +++++++++++-----------
> 1 file changed, 11 insertions(+), 11 deletions(-)
>
>diff --git a/net/devlink/leftover.c b/net/devlink/leftover.c
>index 491f821c8b77..1e23b2da78cc 100644
>--- a/net/devlink/leftover.c
>+++ b/net/devlink/leftover.c
>@@ -5263,7 +5263,13 @@ static void devlink_param_notify(struct devlink *devlink,
> 	WARN_ON(cmd != DEVLINK_CMD_PARAM_NEW && cmd != DEVLINK_CMD_PARAM_DEL &&
> 		cmd != DEVLINK_CMD_PORT_PARAM_NEW &&
> 		cmd != DEVLINK_CMD_PORT_PARAM_DEL);
>-	ASSERT_DEVLINK_REGISTERED(devlink);
>+
>+	/* devlink_notify_register() / devlink_notify_unregister()
>+	 * will replay the notifications if the params are added/removed
>+	 * outside of the lifetime of the instance.
>+	 */
>+	if (!devl_is_registered(devlink))
>+		return;
> 
> 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
> 	if (!msg)
>@@ -10915,8 +10921,6 @@ int devlink_params_register(struct devlink *devlink,
> 	const struct devlink_param *param = params;
> 	int i, err;
> 
>-	ASSERT_DEVLINK_NOT_REGISTERED(devlink);

Hmm, params list is not protected by any lock. The protection it used
was that it is static after registration. You changed it but didn't add
the lock. All param register/unregister functions need to be renamed to
devl_* and assert instance lock. I will fix this.

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