Re: [PATCH v2 03/46] mtd: Don't unconditionally unregister reboot notifier

From: Boris Brezillon
Date: Wed Sep 21 2016 - 10:31:29 EST


On Wed, 21 Sep 2016 11:45:12 +0200
Daniel Walter <dwalter@xxxxxxxxxxxxx> wrote:

> From: Richard Weinberger <richard@xxxxxx>
>
> del_mtd_device() is allowed to fail.
> i.e. when the MTD is busy.
> Unregister the reboot notifier only when we're really
> about to delete the MTD.
>
> Signed-off-by: Richard Weinberger <richard@xxxxxx>
> ---
> drivers/mtd/mtdcore.c | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
> index e3936b8..36e5fb0 100644
> --- a/drivers/mtd/mtdcore.c
> +++ b/drivers/mtd/mtdcore.c
> @@ -654,17 +654,22 @@ int mtd_device_unregister(struct mtd_info *master)
> {
> int err;
>
> - if (master->_reboot)
> - unregister_reboot_notifier(&master->reboot_notifier);
> -
> err = del_mtd_partitions(master);
> if (err)
> return err;
>
> if (!device_is_registered(&master->dev))
> - return 0;
> + goto unregister;
>
> - return del_mtd_device(master);
> + err = del_mtd_device(master);
> + if (err)
> + return err;
> +
> +unregister:
> + if (master->_reboot)
> + unregister_reboot_notifier(&master->reboot_notifier);
> +
> + return 0;

How about:

if (device_is_registered(&master->dev)) {
err = del_mtd_device(master);
if (err)
return err;
}

if (master->_reboot)
unregister_reboot_notifier(&master->reboot_notifier);

return 0;

This way you get rid of the unregister label, which IMHO improves
readability.

> }
> EXPORT_SYMBOL_GPL(mtd_device_unregister);
>