Re: [PATCH -next v2 3/7] md: delay choosing sync direction to md_start_sync()

[Song Liu]

On Tue, Aug 15, 2023 at 2:00 PM Yu Kuai <yukuai1@xxxxxxxxxxxxxxx> wrote:
[...]
> > +
> > +not_running:
> > +     clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
> > +     clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
> > +     clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
> > +     clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
> > +     clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
> > +     mddev_unlock(mddev);
> > +
> > +     wake_up(&resync_wait);
> > +     if (test_and_clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery) &&
> > +         mddev->sysfs_action)
> > +             sysfs_notify_dirent_safe(mddev->sysfs_action);
> >   }
> >
> >   /*
> > @@ -9379,7 +9402,6 @@ void md_check_recovery(struct mddev *mddev)
> >               return;
> >
> >       if (mddev_trylock(mddev)) {
> > -             int spares = 0;
> >               bool try_set_sync = mddev->safemode != 0;
> >
> >               if (!mddev->external && mddev->safemode == 1)
> > @@ -9467,29 +9489,11 @@ void md_check_recovery(struct mddev *mddev)
> >               clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
> >
> >               if (!test_and_clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
> > -                 test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
> > -                     goto not_running;
> > -             if (!md_choose_sync_direction(mddev, &spares))
> > -                     goto not_running;
> > -             if (mddev->pers->sync_request) {
> > -                     if (spares) {
> > -                             /* We are adding a device or devices to an array
> > -                              * which has the bitmap stored on all devices.
> > -                              * So make sure all bitmap pages get written
> > -                              */
> > -                             md_bitmap_write_all(mddev->bitmap);
> > -                     }
> > +                 test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) {
>
> Sorry that I made a mistake here while rebasing v2, here should be
>
> !test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)
>
> With this fixed, there are no new regression for mdadm tests using loop
> devicein my VM.

                if (!test_and_clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
                    !test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) {
                        queue_work(md_misc_wq, &mddev->sync_work);
                } else {

This doesn't look right. Should we do

                if (test_and_clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery) &&
                    !test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) {
                        queue_work(md_misc_wq, &mddev->sync_work);
                } else {

instead?

Thanks,
Song