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

Christoph Hellwig
2018-10-28T15:49:47Z

On Sun, Oct 28, 2018 at 08:51:31AM +0800, Ming Lei wrote:
> On Fri, Oct 26, 2018 at 09:44:15AM +0200, Christoph Hellwig wrote:
> > > 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?
>
> IMO, using UINT_MAX & bs_mask is better because it is self-explanatory
> in the context.

I don't think it is in any way. I understand it because I know the
code, but there is nothing that documents why we do that.