[Cluster-devel] [PATCH 03/27] iomap: mark the iomap argument to iomap_sector const

[Darrick J. Wong]

On Mon, Jul 19, 2021 at 12:34:56PM +0200, Christoph Hellwig wrote:
> Signed-off-by: Christoph Hellwig <hch at lst.de>

/me wonders, does this have any significant effect on the generated
code?

It's probably a good idea to feed the optimizer as much usage info as we
can, though I would imagine that for such a simple function it can
probably tell that we don't change *iomap.

IMHO, constifiying functions is a good way to signal to /programmers/
that they're not intended to touch the arguments, so

Reviewed-by: Darrick J. Wong <djwong at kernel.org>

--D

> ---
>  include/linux/iomap.h | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/include/linux/iomap.h b/include/linux/iomap.h
> index 093519d91cc9cc..f9c36df6a3061b 100644
> --- a/include/linux/iomap.h
> +++ b/include/linux/iomap.h
> @@ -91,8 +91,7 @@ struct iomap {
>  	const struct iomap_page_ops *page_ops;
>  };
>  
> -static inline sector_t
> -iomap_sector(struct iomap *iomap, loff_t pos)
> +static inline sector_t iomap_sector(const struct iomap *iomap, loff_t pos)
>  {
>  	return (iomap->addr + pos - iomap->offset) >> SECTOR_SHIFT;
>  }
> -- 
> 2.30.2
>