On Sat, Oct 29, 2022 at 08:33:22PM -0700, Bart Van Assche wrote:
> On 10/29/22 20:25, Dawei Li wrote:
> > On Sat, Oct 29, 2022 at 08:00:58PM -0700, Bart Van Assche wrote:
> > > On 10/29/22 19:17, Dawei Li wrote:
> > > > diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> > > > index 57ed49f20d2e..7b537afe8b38 100644
> > > > --- a/include/linux/blkdev.h
> > > > +++ b/include/linux/blkdev.h
> > > > @@ -1349,12 +1349,7 @@ static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
> > > > /* assumes size > 256 */
> > > > static inline unsigned int blksize_bits(unsigned int size)
> > > > {
> > > > - unsigned int bits = 8;
> > > > - do {
> > > > - bits++;
> > > > - size >>= 1;
> > > > - } while (size > 256);
> > > > - return bits;
> > > > + return order_base_2((size + SECTOR_SIZE - 1) >> SECTOR_SHIFT) + SECTOR_SHIFT;
> > > > }
> > >
> > > Why the rounding ("+ SECTOR_SIZE - 1")? The blksize_bits() argument should
> > > be an argument of two.
> >
> > Yeah, that's what's supposed to be.
> > But I thought maybe a "just in case" is more robust?
> > Should we consider these corner cases(!is_power_of_2())?
>
> I don't think that the Linux kernel supports block sizes that are not a
> power of two. Hence my request to leave out the rounding code. Keeping that
> code would be misleading because it would suggest that the blksize_bits()
> argument can be something else than a power of two.
Thanks for the review, bart.
Will resend the updated patch.
>
> Thanks,
>
> Bart.
>
