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

Lorenzo Stoakes <[email protected]> Thu, 28 Aug 2025 19:00:27 +0100
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Message-ID <[email protected]> 
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 <[email protected]>
> Cc: "James E.J. Bottomley" <[email protected]>
> Cc: "Martin K. Petersen" <[email protected]>
> Signed-off-by: David Hildenbrand <[email protected]>

LGTM, so:

Reviewed-by: Lorenzo Stoakes <[email protected]>

> ---
>  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
>