Re: [PATCH 02/12] md: add a new enum type sync_action

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

On Mon, 3 Jun 2024 20:58:05 +0800
Yu Kuai <yukuai3@huawei.com> wrote:

> In order to make code related to sync_thread cleaner in following
> patches, also add detail comment about each sync action. And also
> prepare to remove the related recovery_flags in the fulture.
> 
> Signed-off-by: Yu Kuai <yukuai3@huawei.com>
> ---
>  drivers/md/md.h | 57 ++++++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 56 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/md/md.h b/drivers/md/md.h
> index 170412a65b63..6b9d9246f260 100644
> --- a/drivers/md/md.h
> +++ b/drivers/md/md.h
> @@ -34,6 +34,61 @@
>   */
>  #define	MD_FAILFAST	(REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT)
>  
> +/* Status of sync thread. */
> +enum sync_action {
> +	/*
> +	 * Represent by MD_RECOVERY_SYNC, start when:
> +	 * 1) after assemble, sync data from first rdev to other copies, this
> +	 * must be done first before other sync actions and will only execute
> +	 * once;
> +	 * 2) resize the array(notice that this is not reshape), sync data
> for
> +	 * the new range;
> +	 */
> +	ACTION_RESYNC,
> +	/*
> +	 * Represent by MD_RECOVERY_RECOVER, start when:
> +	 * 1) for new replacement, sync data based on the replace rdev or
> +	 * available copies from other rdev;
> +	 * 2) for new member disk while the array is degraded, sync data from
> +	 * other rdev;
> +	 * 3) reassemble after power failure or re-add a hot removed rdev,
> sync
> +	 * data from first rdev to other copies based on bitmap;
> +	 */
> +	ACTION_RECOVER,
> +	/*
> +	 * Represent by MD_RECOVERY_SYNC | MD_RECOVERY_REQUESTED |
> +	 * MD_RECOVERY_CHECK, start when user echo "check" to sysfs api
> +	 * sync_action, used to check if data copies from differenct rdev are
> +	 * the same. The number of mismatch sectors will be exported to user
> +	 * by sysfs api mismatch_cnt;
> +	 */
> +	ACTION_CHECK,
> +	/*
> +	 * Represent by MD_RECOVERY_SYNC | MD_RECOVERY_REQUESTED, start when
> +	 * user echo "repair" to sysfs api sync_action, usually paired with
> +	 * ACTION_CHECK, used to force syncing data once user found that
> there
> +	 * are inconsistent data,
> +	 */
> +	ACTION_REPAIR,
> +	/*
> +	 * Represent by MD_RECOVERY_RESHAPE, start when new member disk is
> added
> +	 * to the conf, notice that this is different from spares or
> +	 * replacement;
> +	 */
> +	ACTION_RESHAPE,
> +	/*
> +	 * Represent by MD_RECOVERY_FROZEN, can be set by sysfs api
> sync_action
> +	 * or internal usage like setting the array read-only, will forbid
> above
> +	 * actions.
> +	 */
> +	ACTION_FROZEN,
> +	/*
> +	 * All above actions don't match.
> +	 */
> +	ACTION_IDLE,
> +	NR_SYNC_ACTIONS,
> +};

I like if counter is keep in same style as rest enum values, like ACTION_COUNT.

Anyway LGTM.

Mariusz