Re: [PATCH printk v2 09/38] netconsole: use console_is_enabled()

Petr Mladek
2022-10-21T13:16:29Z

On Wed 2022-10-19 17:01:31, John Ogness wrote:
> Replace (console->flags & CON_ENABLED) usage with console_is_enabled().
>
> Signed-off-by: John Ogness <john.ogness@linutronix.de>

The change is straightforward:

Reviewed-by: Petr Mladek <pmladek@suse.com>

The comment below is just a lamentation about the netconsole code.

> ---
> drivers/net/netconsole.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
> index bdff9ac5056d..073e59a06f21 100644
> --- a/drivers/net/netconsole.c
> +++ b/drivers/net/netconsole.c
> @@ -332,7 +332,7 @@ static ssize_t enabled_store(struct config_item *item,
> }
>
> if (enabled) { /* true */
> - if (nt->extended && !(netconsole_ext.flags & CON_ENABLED)) {
> + if (nt->extended && !console_is_enabled(&netconsole_ext)) {
> netconsole_ext.flags |= CON_ENABLED;
> register_console(&netconsole_ext);
> }
> @@ -915,7 +915,7 @@ static int __init init_netconsole(void)
> if (err)
> goto undonotifier;
>
> - if (netconsole_ext.flags & CON_ENABLED)
> + if (console_is_enabled(&netconsole_ext))
> register_console(&netconsole_ext);
> register_console(&netconsole);
> pr_info("network logging started\n");

Just for record:

This looks like a (mis)use of CON_ENABLED flag. It took me some time
to understand why pre-enabled consoles are handled special way in
register_console(). I partly documented it in
try_enable_preferred_console():

/*
* Some consoles, such as pstore and netconsole, can be enabled even
* without matching. Accept the pre-enabled consoles only when match()
* and setup() had a chance to be called.
*/
if (console_is_enabled(newcon) && (c->user_specified == user_specified))
return 0;

In my bottom driver, I have a patch cleaning this. It is part of a bigger
clean up that is not ready for upstream :-/

Best Regards,
Petr