Hi Richard,

On Fri, 2012-05-11 at 14:14 +0200, Richard Weinberger wrote:
>  struct ubi_map_req {
>         __s32 lnum;
> -       __s8  dtype;
> -       __s8  padding[3];
> +       __s8  padding[4];
>  } __packed;


The "dtype" field is part of ABI, and merging it with padding is bad
because padding holds "free" fields, which can be used in future. But
"dtype" is not really free. I think it should stay here. You should put
a comment explaining that it was used in the past for this and that, but
now unused and ignored by UBI. Probably a date when we stopped using it
would also be good.

May be it even deserves to be in a separate patches for this one and
ubi_leb_change_req ?

Thanks !

-- 
Best Regards,
Artem Bityutskiy