Re: [PATCH v2 07/10] block: use sectors_to_npage() and PAGE_SECTORS to clean up code

From: Matthew Wilcox
Date: Fri May 15 2020 - 00:19:29 EST


On Thu, May 07, 2020 at 03:50:57PM +0800, Zhen Lei wrote:
> +++ b/block/blk-settings.c
> @@ -150,7 +150,7 @@ void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_secto
> unsigned int max_sectors;
>
> if ((max_hw_sectors << 9) < PAGE_SIZE) {
> - max_hw_sectors = 1 << (PAGE_SHIFT - 9);
> + max_hw_sectors = PAGE_SECTORS;

Surely this should be:

if (max_hw_sectors < PAGE_SECTORS) {
max_hw_sectors = PAGE_SECTORS;

... no?

> - page = read_mapping_page(mapping,
> - (pgoff_t)(n >> (PAGE_SHIFT - 9)), NULL);
> + page = read_mapping_page(mapping, (pgoff_t)sectors_to_npage(n), NULL);

... again, get the type right, and you won't need the cast.