Re: [PATCH -next v3 6/7] md: factor out a helper rdev_addable() from remove_and_add_spares()

[Yu Kuai]

Hi,

在 2023/08/22 7:22, Song Liu 写道:
> On Sun, Aug 20, 2023 at 2:13 AM Yu Kuai <yukuai1@xxxxxxxxxxxxxxx> wrote:
> > From: Yu Kuai <yukuai3@xxxxxxxxxx>
> >
> > There are no functional changes, just to make the code simpler and
> > prepare to delay remove_and_add_spares() to md_start_sync().
> >
> > Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
> > ---
> >   drivers/md/md.c | 28 ++++++++++++++++------------
> >   1 file changed, 16 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/md/md.c b/drivers/md/md.c
> > index 11d27c934fdd..cdc361c521d4 100644
> > --- a/drivers/md/md.c
> > +++ b/drivers/md/md.c
> > @@ -9177,6 +9177,20 @@ static bool rdev_is_spare(struct md_rdev *rdev)
> >                 !test_bit(Faulty, &rdev->flags);
> >   }
> >
> > +static bool rdev_addable(struct md_rdev *rdev)
> > +{
> > +       if (test_bit(Candidate, &rdev->flags) || rdev->raid_disk >= 0 ||
> > +           test_bit(Faulty, &rdev->flags))
> > +               return false;
> > +
> > +       if (!test_bit(Journal, &rdev->flags) && !md_is_rdwr(rdev->mddev) &&
>
> Instead of straightforward refactoring, I hope we can make these rdev_*
> helpers more meaningful, and hopefullly reusable. For example, let's define
> the meaning of "addable", and write the function to match that meaning. In
> this case, I think we shouldn't check md_is_rdwr() inside rdev_addable().
>
> Does this make sense?

Yes, this make sense, rdev can be added to read-only array.

There are total three callers of pers->hot_add_sisk, I'll try to find if
they have common conditions.

Thanks,
Kuai

> Thanks,
> Song
>
>
> > +           !(rdev->saved_raid_disk >= 0 &&
> > +             !test_bit(Bitmap_sync, &rdev->flags)))
> > +               return false;
> > +
> > +       return true;
> > +}
> > +
> >   static int remove_and_add_spares(struct mddev *mddev,
> >                                   struct md_rdev *this)
> >   {
> > @@ -9227,20 +9241,10 @@ static int remove_and_add_spares(struct mddev *mddev,
> >                          continue;
> >                  if (rdev_is_spare(rdev))
> >                          spares++;
> > -               if (test_bit(Candidate, &rdev->flags))
> > +               if (!rdev_addable(rdev))
> >                          continue;
> > -               if (rdev->raid_disk >= 0)
> > -                       continue;
> > -               if (test_bit(Faulty, &rdev->flags))
> > -                       continue;
> > -               if (!test_bit(Journal, &rdev->flags)) {
> > -                       if (!md_is_rdwr(mddev) &&
> > -                           !(rdev->saved_raid_disk >= 0 &&
> > -                             !test_bit(Bitmap_sync, &rdev->flags)))
> > -                               continue;
> > -
> > +               if (!test_bit(Journal, &rdev->flags))
> >                          rdev->recovery_offset = 0;
> > -               }
> >                  if (mddev->pers->hot_add_disk(mddev, rdev) == 0) {
> >                          /* failure here is OK */
> >                          sysfs_link_rdev(mddev, rdev);
> > --
> > 2.39.2
> .