On Fri, Apr 18, 2025 at 9:17 AM Yu Kuai <yukuai1@huaweicloud.com> wrote:
>
> From: Yu Kuai <yukuai3@huawei.com>
>
> Following patch will use gendisk to check if there are normal IO
> completed or inflight, to fix a problem in mdraid that foreground IO
> can be starved by background sync IO in later patches.
>
> Signed-off-by: Yu Kuai <yukuai3@huawei.com>
> ---
> drivers/md/dm-raid.c | 3 +++
> drivers/md/md.h | 3 ++-
> 2 files changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
> index 6adc55fd90d3..127138c61be5 100644
> --- a/drivers/md/dm-raid.c
> +++ b/drivers/md/dm-raid.c
> @@ -14,6 +14,7 @@
> #include "raid5.h"
> #include "raid10.h"
> #include "md-bitmap.h"
> +#include "dm-core.h"
>
> #include <linux/device-mapper.h>
>
> @@ -3308,6 +3309,7 @@ static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv)
>
> /* Disable/enable discard support on raid set. */
> configure_discard_support(rs);
> + rs->md.dm_gendisk = ti->table->md->disk;
>
> mddev_unlock(&rs->md);
> return 0;
> @@ -3327,6 +3329,7 @@ static void raid_dtr(struct dm_target *ti)
>
> mddev_lock_nointr(&rs->md);
> md_stop(&rs->md);
> + rs->md.dm_gendisk = NULL;
> mddev_unlock(&rs->md);
>
> if (work_pending(&rs->md.event_work))
> diff --git a/drivers/md/md.h b/drivers/md/md.h
> index 1cf00a04bcdd..9d55b4630077 100644
> --- a/drivers/md/md.h
> +++ b/drivers/md/md.h
> @@ -404,7 +404,8 @@ struct mddev {
> * are happening, so run/
> * takeover/stop are not safe
> */
> - struct gendisk *gendisk;
> + struct gendisk *gendisk; /* mdraid gendisk */
> + struct gendisk *dm_gendisk; /* dm-raid gendisk */
>
> struct kobject kobj;
> int hold_active;
> --
> 2.39.2
>
Looks good to me, reviewed-by: Xiao Ni <xni@redhat.com>