Re: [PATCH md-6.12 1/1] md: add new_level sysfs interface

[Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>]

On Wed, 28 Aug 2024 10:18:28 +0800
Xiao Ni <xni@redhat.com> wrote:

> This interface is used to updating new level during reshape progress.
> Now it doesn't update new level during reshape. So it can't know the
> new level when systemd service mdadm-grow-continue runs. And it can't
> finally change to new level.
> 
> Signed-off-by: Xiao Ni <xni@redhat.com>
> ---
>  drivers/md/md.c | 29 +++++++++++++++++++++++++++++
>  1 file changed, 29 insertions(+)
> 
> diff --git a/drivers/md/md.c b/drivers/md/md.c
> index d3a837506a36..c639eca03df9 100644
> --- a/drivers/md/md.c
> +++ b/drivers/md/md.c
> @@ -4141,6 +4141,34 @@ level_store(struct mddev *mddev, const char *buf,
> size_t len) static struct md_sysfs_entry md_level =
>  __ATTR(level, S_IRUGO|S_IWUSR, level_show, level_store);
>  
> +static ssize_t
> +new_level_show(struct mddev *mddev, char *page)
> +{
> +	return sprintf(page, "%d\n", mddev->new_level);
> +}
> +
> +static ssize_t
> +new_level_store(struct mddev *mddev, const char *buf, size_t len)
> +{
> +	unsigned int n;
> +	int err;
> +
> +	err = kstrtouint(buf, 10, &n);
> +	if (err < 0)
> +		return err;
> +	err = mddev_lock(mddev);
> +	if (err)
> +		return err;
> +
> +	mddev->new_level = n;
> +	md_update_sb(mddev, 1);

I don't see any code behind mddev->new_level handling so I suspect that
md_update_sb() does nothing in this case. Is there something I'm missing?

Thanks,
Mariusz

> +
> +	mddev_unlock(mddev);
> +	return err ?: len;
> +}
> +static struct md_sysfs_entry md_new_level =
> +__ATTR(new_level, 0664, new_level_show, new_level_store);
> +
>  static ssize_t
>  layout_show(struct mddev *mddev, char *page)
>  {
> @@ -5666,6 +5694,7 @@ __ATTR(serialize_policy, S_IRUGO | S_IWUSR,
> serialize_policy_show, 
>  static struct attribute *md_default_attrs[] = {
>  	&md_level.attr,
> +	&md_new_level.attr,
>  	&md_layout.attr,
>  	&md_raid_disks.attr,
>  	&md_uuid.attr,