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

[Yu Kuai]

Hi,

在 2024/06/11 16:31, Mariusz Tkaczyk 写道:
> On Mon, 3 Jun 2024 20:58:05 +0800
> Yu Kuai <yukuai3@xxxxxxxxxx> 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@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 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.

Thanks for the review, however, I didn't find this style "xxx_COUNT" in
md code, AFAIK, "NR_xxx" style is used more, for example:

enum stat_group {
        STAT_READ,
        STAT_WRITE,
        STAT_DISCARD,
        STAT_FLUSH,

        NR_STAT_GROUPS
};

Just to let you know, I'll keep this style in the next version. :)

Thanks,
Kuai
> Anyway LGTM.
>
> Mariusz
> .