Re: [PATCH] md/raid1: prioritize adding disk to 'removed' mirror

[Yu Kuai]

Hi,

在 2023/06/24 1:25, linan666@xxxxxxxxxxxxxxx 写道:
> From: Li Nan <linan122@xxxxxxxxxx>
>
> New disk should be added to "removed" position first instead of to be a
> replacement. Commit 6090368abcb4 ("md/raid10: prioritize adding disk to
> 'removed' mirror") has fixed this issue for raid10. This patch fixes raid1.

This commit message "This patch ..." shound use imperative mood, other
than that, this patch LGTM.

Reviewed-by: Yu Kuai <yukuai3@xxxxxxxxxx>
> Signed-off-by: Li Nan <linan122@xxxxxxxxxx>
> ---
>   drivers/md/raid1.c | 26 +++++++++++++++-----------
>   1 file changed, 15 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
> index 68a9e2d9985b..320bede4bfab 100644
> --- a/drivers/md/raid1.c
> +++ b/drivers/md/raid1.c
> @@ -1782,7 +1782,7 @@ static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
>   {
>   	struct r1conf *conf = mddev->private;
>   	int err = -EEXIST;
> -	int mirror = 0;
> +	int mirror = 0, repl_slot = -1;
>   	struct raid1_info *p;
>   	int first = 0;
>   	int last = conf->raid_disks - 1;
> @@ -1825,17 +1825,21 @@ static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
>   			break;
>   		}
>   		if (test_bit(WantReplacement, &p->rdev->flags) &&
> -		    p[conf->raid_disks].rdev == NULL) {
> -			/* Add this device as a replacement */
> -			clear_bit(In_sync, &rdev->flags);
> -			set_bit(Replacement, &rdev->flags);
> -			rdev->raid_disk = mirror;
> -			err = 0;
> -			conf->fullsync = 1;
> -			rcu_assign_pointer(p[conf->raid_disks].rdev, rdev);
> -			break;
> -		}
> +		    p[conf->raid_disks].rdev == NULL && repl_slot < 0)
> +			repl_slot = mirror;
>   	}
> +
> +	if (err && repl_slot >= 0) {
> +		/* Add this device as a replacement */
> +		p = conf->mirrors + repl_slot;
> +		clear_bit(In_sync, &rdev->flags);
> +		set_bit(Replacement, &rdev->flags);
> +		rdev->raid_disk = repl_slot;
> +		err = 0;
> +		conf->fullsync = 1;
> +		rcu_assign_pointer(p[conf->raid_disks].rdev, rdev);
> +	}
> +
>   	print_conf(conf);
>   	return err;
>   }