Re: [PATCH 1/3] block: make sure discard bio is aligned with logical block size

[Christoph Hellwig]

>               if (req_sects > UINT_MAX >> 9)
> -                     req_sects = UINT_MAX >> 9;
> +                     req_sects = (UINT_MAX >> 9) & ~bs_mask;

Given that we have this same thing duplicated in write zeroes
what about a documented helper?