Re: [PATCH md-6.8 v2 2/9] md: export helpers to stop sync_thread

[Paul Menzel <pmenzel@molgen.mpg.de>]

Dear Kuai,


Thank you for your patch.

Am 05.03.24 um 08:22 schrieb Yu Kuai:
> From: Yu Kuai <yukuai3@huawei.com>
> 
> The new heleprs will be used in dm-raid in later patches to fix

hel*pe*rs

> regressions and prevent calling md_reap_sync_thread() directly.

Please list the new functions.

1.  md_idle_sync_thread(struct mddev *mddev);
2.  md_frozen_sync_thread(struct mddev *mddev);
3.  md_unfrozen_sync_thread(struct mddev *mddev);

I do not like the naming so much. `md_reap_sync_thread()` has the verb 
in imperative mood. At least myself, I would not know what the functions 
do exactly without looking at the implementation.


Kind regards,

Paul


> Signed-off-by: Yu Kuai <yukuai3@huawei.com>
> Signed-off-by: Xiao Ni <xni@redhat.com>
> Acked-by: Mike Snitzer <snitzer@kernel.org>
> ---
>   drivers/md/md.c | 29 +++++++++++++++++++++++++++++
>   drivers/md/md.h |  3 +++
>   2 files changed, 32 insertions(+)
> 
> diff --git a/drivers/md/md.c b/drivers/md/md.c
> index 23f31fd1d024..22e7512a5b1e 100644
> --- a/drivers/md/md.c
> +++ b/drivers/md/md.c
> @@ -4919,6 +4919,35 @@ static void stop_sync_thread(struct mddev *mddev, bool locked, bool check_seq)
>   		mddev_lock_nointr(mddev);
>   }
>   
> +void md_idle_sync_thread(struct mddev *mddev)
> +{
> +	lockdep_assert_held(&mddev->reconfig_mutex);
> +
> +	clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
> +	stop_sync_thread(mddev, true, true);
> +}
> +EXPORT_SYMBOL_GPL(md_idle_sync_thread);
> +
> +void md_frozen_sync_thread(struct mddev *mddev)
> +{
> +	lockdep_assert_held(&mddev->reconfig_mutex);
> +
> +	set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
> +	stop_sync_thread(mddev, true, false);
> +}
> +EXPORT_SYMBOL_GPL(md_frozen_sync_thread);
> +
> +void md_unfrozen_sync_thread(struct mddev *mddev)
> +{
> +	lockdep_assert_held(&mddev->reconfig_mutex);
> +
> +	clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
> +	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
> +	md_wakeup_thread(mddev->thread);
> +	sysfs_notify_dirent_safe(mddev->sysfs_action);
> +}
> +EXPORT_SYMBOL_GPL(md_unfrozen_sync_thread);
> +
>   static void idle_sync_thread(struct mddev *mddev)
>   {
>   	mutex_lock(&mddev->sync_mutex);
> diff --git a/drivers/md/md.h b/drivers/md/md.h
> index 8d881cc59799..437ab70ce79b 100644
> --- a/drivers/md/md.h
> +++ b/drivers/md/md.h
> @@ -781,6 +781,9 @@ extern void md_rdev_clear(struct md_rdev *rdev);
>   extern void md_handle_request(struct mddev *mddev, struct bio *bio);
>   extern int mddev_suspend(struct mddev *mddev, bool interruptible);
>   extern void mddev_resume(struct mddev *mddev);
> +extern void md_idle_sync_thread(struct mddev *mddev);
> +extern void md_frozen_sync_thread(struct mddev *mddev);
> +extern void md_unfrozen_sync_thread(struct mddev *mddev);
>   
>   extern void md_reload_sb(struct mddev *mddev, int raid_disk);
>   extern void md_update_sb(struct mddev *mddev, int force);