Re: [PATCH v2 3/4] md/raid10: fix wrong setting of max_corr_read_errors

[Song Liu]

On Fri, May 5, 2023 at 7:02 PM Yu Kuai <yukuai1@xxxxxxxxxxxxxxx> wrote:
>
> Hi,
>
> 在 2023/05/06 9:23, linan666@xxxxxxxxxxxxxxx 写道:
> > From: Li Nan <linan122@xxxxxxxxxx>
> >
> > max_corr_read_errors should not be negative number. Change it to
> > unsigned int where use it.
> >
>
> Looks good, feel free to add:
>
> Reviewed-by: Yu Kuai <yukuai3@xxxxxxxxxx>
>
> > Fixes: 1e50915fe0bb ("raid: improve MD/raid10 handling of correctable read errors.")
> > Signed-off-by: Li Nan <linan122@xxxxxxxxxx>

Hmm.. Does the current code break in any cases?

Thanks,
Song

> > ---
> >   drivers/md/md.c     | 2 +-
> >   drivers/md/raid10.c | 5 +++--
> >   2 files changed, 4 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/md/md.c b/drivers/md/md.c
> > index fd5c3babcd6d..4a1e566d6bdc 100644
> > --- a/drivers/md/md.c
> > +++ b/drivers/md/md.c
> > @@ -4486,7 +4486,7 @@ __ATTR_PREALLOC(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_stor
> >
> >   static ssize_t
> >   max_corrected_read_errors_show(struct mddev *mddev, char *page) {
> > -     return sprintf(page, "%d\n",
> > +     return sprintf(page, "%u\n",
> >                      atomic_read(&mddev->max_corr_read_errors));
> >   }
> >
> > diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
> > index 4fcfcb350d2b..4d615fcc6a50 100644
> > --- a/drivers/md/raid10.c
> > +++ b/drivers/md/raid10.c
> > @@ -2727,7 +2727,8 @@ static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10
> >       int sect = 0; /* Offset from r10_bio->sector */
> >       int sectors = r10_bio->sectors;
> >       struct md_rdev *rdev;
> > -     int max_read_errors = atomic_read(&mddev->max_corr_read_errors);
> > +     unsigned int max_read_errors =
> > +                     atomic_read(&mddev->max_corr_read_errors);
> >       int d = r10_bio->devs[r10_bio->read_slot].devnum;
> >
> >       /* still own a reference to this rdev, so it cannot
> > @@ -2743,7 +2744,7 @@ static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10
> >       check_decay_read_errors(mddev, rdev);
> >       atomic_inc(&rdev->read_errors);
> >       if (atomic_read(&rdev->read_errors) > max_read_errors) {
> > -             pr_notice("md/raid10:%s: %pg: Raid device exceeded read_error threshold [cur %d:max %d]\n",
> > +             pr_notice("md/raid10:%s: %pg: Raid device exceeded read_error threshold [cur %u:max %u]\n",
> >                         mdname(mddev), rdev->bdev,
> >                         atomic_read(&rdev->read_errors), max_read_errors);
> >               pr_notice("md/raid10:%s: %pg: Failing raid device\n",
> >
>