Bug#837964: 95a05b3 broke mdadm --add on my superblock 1.0 array

[Anthony DeRobertis]

On Wed, Sep 21, 2016 at 10:40:22PM -0400, Guoqing Jiang wrote:
> 
> Does the below change work? Thanks.

Yes, this patch (after un-email-mangling it) fixes it.

> 
> diff --git a/super1.c b/super1.c
> index 9f62d23..6a0b075 100644
> --- a/super1.c
> +++ b/super1.c
> @@ -2433,7 +2433,10 @@ static int write_bitmap1(struct supertype *st, int
> fd, enum bitmap_update update
>                         memset(buf, 0xff, 4096);
>                 memcpy(buf, (char *)bms, sizeof(bitmap_super_t));
> 
> -               towrite = calc_bitmap_size(bms, 4096);
> +               if (__le32_to_cpu(bms->nodes) == 0)
> +                       towrite = calc_bitmap_size(bms, 512);
> +               else
> +                       towrite = calc_bitmap_size(bms, 4096);
>                 while (towrite > 0) {
> 
> Regards,
> Guoqing