Re: [PATCH] block: refactor duplicated macros

[Dan Williams]

On Sun, Feb 23, 2020 at 9:04 AM Matteo Croce <mcroce@xxxxxxxxxx> wrote:
>
> The macros PAGE_SECTORS, PAGE_SECTORS_SHIFT and SECTOR_MASK are defined
> several times in different flavours across the whole tree.
> Define them just once in a common header.
>
> Signed-off-by: Matteo Croce <mcroce@xxxxxxxxxx>
> ---
>  block/blk-lib.c                  |  2 +-
>  drivers/block/brd.c              |  3 ---
>  drivers/block/null_blk_main.c    |  4 ----
>  drivers/block/zram/zram_drv.c    |  8 ++++----
>  drivers/block/zram/zram_drv.h    |  2 --
>  drivers/dax/super.c              |  2 +-

For the dax change:

Acked-by: Dan Williams <dan.j.williams@xxxxxxxxx>

However...

[..]
>  include/linux/blkdev.h           |  4 ++++
[..]
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index 053ea4b51988..b3c9be6906a0 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -910,6 +910,10 @@ static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
>  #define SECTOR_SIZE (1 << SECTOR_SHIFT)
>  #endif
>
> +#define PAGE_SECTORS_SHIFT     (PAGE_SHIFT - SECTOR_SHIFT)
> +#define PAGE_SECTORS           (1 << PAGE_SECTORS_SHIFT)
> +#define SECTOR_MASK            (PAGE_SECTORS - 1)
> +

...I think SECTOR_MASK is misnamed given it considers pages, and
should probably match the polarity of PAGE_MASK, i.e.

#define PAGE_SECTORS_MASK            (~(PAGE_SECTORS - 1))