Re: [RFC PATCH 5/5] md/raid1: introduce rectify action to repair badblocks

[Zheng Qixing]

在 2026/1/14 11:11, Li Nan 写道:
> 在 2025/12/31 15:09, Zheng Qixing 写道:
> > From: Zheng Qixing <zhengqixing@xxxxxxxxxx>
> >
> > Add support for repairing known badblocks in RAID1. When disks
> > have known badblocks (shown in sysfs bad_blocks), data can be
> > read from other healthy disks in the array and written to repair
> > the badblock areas and clear it in bad_blocks.
> >
> > echo rectify > sync_action can trigger this action.
> >
> > Signed-off-by: Zheng Qixing <zhengqixing@xxxxxxxxxx>
>
> > +static void end_rectify_read(struct bio *bio)
> > +{
> > +    struct r1bio *r1_bio = get_resync_r1bio(bio);
> > +    struct r1conf *conf = r1_bio->mddev->private;
> > +    struct md_rdev *rdev;
> > +    struct bio *next_bio;
> > +    bool all_fail = true;
> > +    int i;
> > +
> > +    update_head_pos(r1_bio->read_disk, r1_bio);
> > +
> > +    if (!bio->bi_status) {
> > +        set_bit(R1BIO_Uptodate, &r1_bio->state);
> > +        goto out;
> > +    }
> > +
> > +    for (i = r1_bio->read_disk + 1; i < conf->raid_disks; i++) {
> > +        rdev = conf->mirrors[i].rdev;
> > +        if (!rdev || test_bit(Faulty, &rdev->flags))
> > +            continue;
> > +
> > +        next_bio = r1_bio->bios[i];
> > +        if (next_bio->bi_end_io == end_rectify_read) {
> > +            next_bio->bi_opf &= ~MD_FAILFAST;
>
> Why set MD_FAILFAST and clear it soon?
> And submit_rectify_read() will clear it again.


Indeed.

> > +static void rectify_request_write(struct mddev *mddev, struct r1bio *r1_bio)
> > +{
> > +    struct r1conf *conf = mddev->private;
> > +    struct bio *wbio = NULL;
> > +    int wcnt = 0;
> > +    int i;
> > +
> > +    if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
> > +        submit_rectify_read(r1_bio);
> > +        return;
> > +    }
> > +
> > +    atomic_set(&r1_bio->remaining, 0);
> > +    for (i = 0; i < conf->raid_disks; i++) {
> > +        wbio = r1_bio->bios[i];
> > +        if (wbio->bi_end_io == end_rectify_write) {
> > +            atomic_inc(&r1_bio->remaining);
> > +            wcnt++;
> > +            submit_bio_noacct(wbio);
> > +        }
> > +    }
> > +
> > +    if (unlikely(!wcnt)) {
> > +        md_done_sync(r1_bio->mddev, r1_bio->sectors);
> > +        put_buf(r1_bio);
> > +    }
>
> How can 'wcnt' be 0?


Oh, I forgot to check the faulty state of rdev.😳

> > +}
> > +
> > +static void handle_rectify_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
> > +{
> > +    struct md_rdev *rdev;
> > +    struct bio *bio;
> > +    int i;
> > +
> > +    for (i = 0; i < conf->raid_disks; i++) {
> > +        rdev = conf->mirrors[i].rdev;
> > +        bio = r1_bio->bios[i];
> > +        if (bio->bi_end_io == NULL)
> > +            continue;
> > +
> > +        if (!bio->bi_status && bio->bi_end_io == end_rectify_write &&
> > +            test_bit(R1BIO_MadeGood, &r1_bio->state)) {
> > +            rdev_clear_badblocks(rdev, r1_bio->sector,
> > +                         r1_bio->sectors, 0);
> > +        }
>
> Reuse handle_sync_write_finished() seems better.

Good point.


Thanks,

Qixing