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References: <20230619204826.755559-1-yukuai1@huaweicloud.com> <20230619204826.755559-4-yukuai1@huaweicloud.com>
In-Reply-To: <20230619204826.755559-4-yukuai1@huaweicloud.com>
From:   Xiao Ni <xni@redhat.com>
Date:   Tue, 20 Jun 2023 16:52:35 +0800
Message-ID: <CALTww2_jEw+vOn+jp_p=b9mUO-7ovmdn=0-gzCmYD1O0HHqQUw@mail.gmail.com>
Subject: Re: [PATCH -next 3/8] raid5: fix missing io accounting in raid5_align_endio()
To:     Yu Kuai <yukuai1@huaweicloud.com>
Cc:     song@kernel.org, linux-raid@vger.kernel.org,
        linux-kernel@vger.kernel.org, yukuai3@huawei.com,
        yi.zhang@huawei.com, yangerkun@huawei.com
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On Mon, Jun 19, 2023 at 8:50=E2=80=AFPM Yu Kuai <yukuai1@huaweicloud.com> w=
rote:
>
> From: Yu Kuai <yukuai3@huawei.com>
>
> Io will only be accounted as done from raid5_align_endio() if the io
> succeed, and io inflight counter will be leaked if such io failed.
>
> Fix this problem by switching to use md_account_bio() for io accounting.
>
> Signed-off-by: Yu Kuai <yukuai3@huawei.com>
> ---
>  drivers/md/raid5.c | 29 ++++++++---------------------
>  1 file changed, 8 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
> index cef0b400b2ee..4cdb35e54251 100644
> --- a/drivers/md/raid5.c
> +++ b/drivers/md/raid5.c
> @@ -5468,26 +5468,17 @@ static struct bio *remove_bio_from_retry(struct r=
5conf *conf,
>   */
>  static void raid5_align_endio(struct bio *bi)
>  {
> -       struct md_io_clone *md_io_clone =3D bi->bi_private;
> -       struct bio *raid_bi =3D md_io_clone->orig_bio;
> -       struct mddev *mddev;
> -       struct r5conf *conf;
> -       struct md_rdev *rdev;
> +       struct bio *raid_bi =3D bi->bi_private;
> +       struct md_rdev *rdev =3D (void *)raid_bi->bi_next;
> +       struct mddev *mddev =3D rdev->mddev;
> +       struct r5conf *conf =3D mddev->private;
>         blk_status_t error =3D bi->bi_status;
> -       unsigned long start_time =3D md_io_clone->start_time;
>
>         bio_put(bi);
> -
> -       rdev =3D (void*)raid_bi->bi_next;
>         raid_bi->bi_next =3D NULL;
> -       mddev =3D rdev->mddev;
> -       conf =3D mddev->private;
> -
>         rdev_dec_pending(rdev, conf->mddev);
>
>         if (!error) {
> -               if (blk_queue_io_stat(raid_bi->bi_bdev->bd_disk->queue))
> -                       bio_end_io_acct(raid_bi, start_time);
>                 bio_endio(raid_bi);
>                 if (atomic_dec_and_test(&conf->active_aligned_reads))
>                         wake_up(&conf->wait_for_quiescent);
> @@ -5506,7 +5497,6 @@ static int raid5_read_one_chunk(struct mddev *mddev=
, struct bio *raid_bio)
>         struct md_rdev *rdev;
>         sector_t sector, end_sector, first_bad;
>         int bad_sectors, dd_idx;
> -       struct md_io_clone *md_io_clone;
>         bool did_inc;
>
>         if (!in_chunk_boundary(mddev, raid_bio)) {
> @@ -5543,16 +5533,13 @@ static int raid5_read_one_chunk(struct mddev *mdd=
ev, struct bio *raid_bio)
>                 return 0;
>         }
>
> -       align_bio =3D bio_alloc_clone(rdev->bdev, raid_bio, GFP_NOIO,
> -                                   &mddev->io_clone_set);
> -       md_io_clone =3D container_of(align_bio, struct md_io_clone, bio_c=
lone);
> +       md_account_bio(mddev, &raid_bio);
>         raid_bio->bi_next =3D (void *)rdev;
> -       if (blk_queue_io_stat(raid_bio->bi_bdev->bd_disk->queue))
> -               md_io_clone->start_time =3D bio_start_io_acct(raid_bio);
> -       md_io_clone->orig_bio =3D raid_bio;
>
> +       align_bio =3D bio_alloc_clone(rdev->bdev, raid_bio, GFP_NOIO,
> +                                   &mddev->bio_set);
>         align_bio->bi_end_io =3D raid5_align_endio;
> -       align_bio->bi_private =3D md_io_clone;
> +       align_bio->bi_private =3D raid_bio;
>         align_bio->bi_iter.bi_sector =3D sector;
>
>         /* No reshape active, so we can trust rdev->data_offset */
> --
> 2.39.2
>

Reviewed-by: Xiao Ni <xni@redhat.com>