On Mon, May 13, 2024 at 6:19 PM Yu Kuai <yukuai1@xxxxxxxxxxxxxxx> wrote:
>
> From: Yu Kuai <yukuai3@xxxxxxxxxx>
>
> In order to make code related to sync_thread cleaner in following
> patches, also add detail comment about each sync action.
>
> Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
> ---
> 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 2a1cb7b889e5..2edad966f90a 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
Same question with patch 01 here
Regards
Xiao
> + * 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,
> +};
> +
> /*
> * The struct embedded in rdev is used to serialize IO.
> */
> @@ -571,7 +626,7 @@ enum recovery_flags {
> /* interrupted because io-error */
> MD_RECOVERY_ERROR,
>
> - /* flags determines sync action */
> + /* flags determines sync action, see details in enum sync_action */
>
> /* if just this flag is set, action is resync. */
> MD_RECOVERY_SYNC,
> --
> 2.39.2
>
