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

[Yu Kuai]

Hi,

在 2023/08/23 19:25, Song Liu 写道:
> On Wed, Aug 23, 2023 at 1:37 AM Yu Kuai <yukuai1@xxxxxxxxxxxxxxx> wrote:
> >
> [...]
> > > diff --git i/drivers/md/md.c w/drivers/md/md.c
> > > index 78be7811a89f..8cb855d03e0a 100644
> > > --- i/drivers/md/md.c
> > > +++ w/drivers/md/md.c
> > > @@ -9117,6 +9117,20 @@ void md_do_sync(struct md_thread *thread)
> > >    }
> > >    EXPORT_SYMBOL_GPL(md_do_sync);
> > >
> > > +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;
> > > +       return true;
> > > +}
> > > +
> > > +static bool rdev_is_readd(struct md_rdev *rdev)
> > > +{
> > > +       return rdev->saved_raid_disk >= 0 ||
> > > +               !test_bit(Bitmap_sync, &rdev->flags);
> > This should use '&&' instead of '||' ?
> >
> > > +}
> > > +
> > >    static int remove_and_add_spares(struct mddev *mddev,
> > >                                    struct md_rdev *this)
> > >    {
> > > @@ -9176,25 +9190,24 @@ static int remove_and_add_spares(struct mddev *mddev,
> > >           rdev_for_each(rdev, mddev) {
> > >                   if (this && this != rdev)
> > >                           continue;
> > > -               if (test_bit(Candidate, &rdev->flags))
> > > -                       continue;
> > >                   if (rdev->raid_disk >= 0 &&
> > >                       !test_bit(In_sync, &rdev->flags) &&
> > >                       !test_bit(Journal, &rdev->flags) &&
> > >                       !test_bit(Faulty, &rdev->flags))
> > >                           spares++;
> > > -               if (rdev->raid_disk >= 0)
> > > +
> > > +               if (!rdev_addable(rdev))
> > >                           continue;
> > > -               if (test_bit(Faulty, &rdev->flags))
> > > +
> > > +               if (test_bit(Journal, &rdev->flags))
> > > +                       goto hot_add_disk;
> > > +
> >
> > I understand what you mean now, but I must use the exact same judgement
> > in the new helper md_spares_need_change() in patch 7, there will be
> > redundant code this way.
> >
> > How about this, rework rdev_addable():
>
> Yeah, this was another option that I was thinking about. Let's go with
> this version.
Ok, and I'll do this for rdev_removeable() in patch 4 as well.

Thanks,
Kuai

> Thanks,
> Song
>
> >     static bool rdev_addable(struct md_rdev *rdev)
> >     {
> > +         /* rdev is already used, don't add it again. */
> >             if (test_bit(Candidate, &rdev->flags) || rdev->raid_disk >= 0 ||
> >                 test_bit(Faulty, &rdev->flags))
> >                     return false;
> >
> > ~         /* Allow to add journal disk. */
> > ~         if (test_bit(Journal, &rdev->flags))
> > ~_                return true;
> >
> > ~         /* Allow to add if array is read-write. */
> > +         if (md_is_rdwr(rdev->mddev))
> > +                 return true;
> > +
> > +         /*
> > +          * For read-only array, only allow to readd a rdev. And if
> > bitmap is
> > +          * used, don't allow to readd a rdev that is too old.
> > +          */
> > +         if (rdev->saved_raid_disk >=0 && !test_bit(Bitmap_sync,
> > &rdev->flags))
> > +                 return true;
> > +
> > +         return false;
> >     }
> .