Re: [RFC PATCH v2] md: remove legacy 1s delay in md_notify_reboot

["Yu Kuai" <yukuai@fnnas.com>]

在 2025/11/22 3:14, Tarun Sahu 写道:

> During system shutdown, the md driver registered notifier function
> (md_notify_reboot) currently imposes a hardcoded one-second delay.
>
> This delay was introduced approximately 23 years ago and was likely
> necessary for the hardware generation of that time. Proposing this
> patch to make sure there are no known devices that need this delay.
>
> Signed-off-by: Tarun Sahu <tarunsahu@google.com>
> ---
> v2:
> 	Added linux-scsi mailing list
>
>   drivers/md/md.c | 11 -----------
>   1 file changed, 11 deletions(-)
>
> diff --git a/drivers/md/md.c b/drivers/md/md.c
> index b086cbf24086..66c4d66b4b86 100644
> --- a/drivers/md/md.c
> +++ b/drivers/md/md.c
> @@ -9704,7 +9704,6 @@ static int md_notify_reboot(struct notifier_block *this,
>   			    unsigned long code, void *x)
>   {
>   	struct mddev *mddev;
> -	int need_delay = 0;
>   
>   	spin_lock(&all_mddevs_lock);
>   	list_for_each_entry(mddev, &all_mddevs, all_mddevs) {
> @@ -9718,21 +9717,11 @@ static int md_notify_reboot(struct notifier_block *this,
>   				mddev->safemode = 2;
>   			mddev_unlock(mddev);
>   		}
> -		need_delay = 1;
>   		spin_lock(&all_mddevs_lock);
>   		mddev_put_locked(mddev);
>   	}
>   	spin_unlock(&all_mddevs_lock);
>   
> -	/*
> -	 * certain more exotic SCSI devices are known to be
> -	 * volatile wrt too early system reboots. While the
> -	 * right place to handle this issue is the given
> -	 * driver, we do want to have a safe RAID driver ...
> -	 */
> -	if (need_delay)
> -		msleep(1000);
> -
>   	return NOTIFY_DONE;
>   }
>   

Applied to md-6.19
-- 
Thanks,
Kuai