[PATCH v1 29/36] scsi: scsi_lib: drop nth_page() usage within SG entry

[Lorenzo Stoakes]

On Thu, Aug 28, 2025 at 12:01:33AM +0200, David Hildenbrand wrote:
> It's no longer required to use nth_page() when iterating pages within a
> single SG entry, so let's drop the nth_page() usage.
>
> Reviewed-by: Bart Van Assche <bvanassche at acm.org>
> Cc: "James E.J. Bottomley" <James.Bottomley at HansenPartnership.com>
> Cc: "Martin K. Petersen" <martin.petersen at oracle.com>
> Signed-off-by: David Hildenbrand <david at redhat.com>

LGTM, so:

Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes at oracle.com>

> ---
>  drivers/scsi/scsi_lib.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
> index 0c65ecfedfbd6..d7e42293b8645 100644
> --- a/drivers/scsi/scsi_lib.c
> +++ b/drivers/scsi/scsi_lib.c
> @@ -3148,8 +3148,7 @@ void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count,
>  	/* Offset starting from the beginning of first page in this sg-entry */
>  	*offset = *offset - len_complete + sg->offset;
>
> -	/* Assumption: contiguous pages can be accessed as "page + i" */

Nice to drop this :)

> -	page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT));
> +	page = sg_page(sg) + (*offset >> PAGE_SHIFT);
>  	*offset &= ~PAGE_MASK;
>
>  	/* Bytes in this sg-entry from *offset to the end of the page */
> --
> 2.50.1
>