Re: [PATCH 01/13] tty: simplify tty_dev_name_to_number() using guard(mutex)

From: Ilpo Järvinen
Date: Mon Aug 05 2024 - 10:25:21 EST


On Mon, 5 Aug 2024, Jiri Slaby (SUSE) wrote:

> In tty_dev_name_to_number(), a guard can help to make the code easier to
> follow. Especially how 0 is returned in the successful case. So use a
> guard there.
>
> Signed-off-by: Jiri Slaby (SUSE) <jirislaby@xxxxxxxxxx>
> ---
> drivers/tty/tty_io.c | 11 ++++-------
> 1 file changed, 4 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
> index bc9aebcb873f..267682bcfea0 100644
> --- a/drivers/tty/tty_io.c
> +++ b/drivers/tty/tty_io.c
> @@ -350,22 +350,19 @@ int tty_dev_name_to_number(const char *name, dev_t *number)
> return ret;
>
> prefix_length = str - name;
> - mutex_lock(&tty_mutex);
> +
> + guard(mutex)(&tty_mutex);
>
> list_for_each_entry(p, &tty_drivers, tty_drivers)
> if (prefix_length == strlen(p->name) && strncmp(name,
> p->name, prefix_length) == 0) {
> if (index < p->num) {
> *number = MKDEV(p->major, p->minor_start + index);
> - goto out;
> + return 0;
> }
> }
>
> - /* if here then driver wasn't found */
> - ret = -ENODEV;
> -out:
> - mutex_unlock(&tty_mutex);
> - return ret;
> + return -ENODEV;
> }
> EXPORT_SYMBOL_GPL(tty_dev_name_to_number);

Should add also #include <linux/cleanup.h>. With that fixed:

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>

--
i.