Commit 6ff54f45 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: simplify bio_map_kern 



Rewrite bio_map_kern using the new bio_add_* helpers and drop the
kerneldoc comment that is superfluous for an internal helper.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDamien Le Moal <dlemoal@kernel.org>
Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20250507120451.4000627-8-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent fddbc51d

block/blk-map.c

+9 −47
Original line number Diff line number Diff line
@@ -317,64 +317,26 @@ static void bio_map_kern_endio(struct bio *bio) 
	kfree(bio);

}



/**

 *	bio_map_kern	-	map kernel address into bio

 *	@data: pointer to buffer to map

 *	@len: length in bytes

 *	@op: bio/request operation

 *	@gfp_mask: allocation flags for bio allocation

 *

 *	Map the kernel address into a bio suitable for io to a block

 *	device. Returns an error pointer in case of error.

 */

static struct bio *bio_map_kern(void *data, unsigned int len,

		enum req_op op, gfp_t gfp_mask)

static struct bio *bio_map_kern(void *data, unsigned int len, enum req_op op,

		gfp_t gfp_mask)

{

	unsigned long kaddr = (unsigned long)data;

	unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;

	unsigned long start = kaddr >> PAGE_SHIFT;

	const int nr_pages = end - start;

	bool is_vmalloc = is_vmalloc_addr(data);

	struct page *page;

	int offset, i;

	unsigned int nr_vecs = bio_add_max_vecs(data, len);

	struct bio *bio;



	bio = bio_kmalloc(nr_pages, gfp_mask);

	bio = bio_kmalloc(nr_vecs, gfp_mask);

	if (!bio)

		return ERR_PTR(-ENOMEM);

	bio_init(bio, NULL, bio->bi_inline_vecs, nr_pages, op);



	if (is_vmalloc) {

		flush_kernel_vmap_range(data, len);

	bio_init(bio, NULL, bio->bi_inline_vecs, nr_vecs, op);

	if (is_vmalloc_addr(data)) {

		bio->bi_private = data;

	}



	offset = offset_in_page(kaddr);

	for (i = 0; i < nr_pages; i++) {

		unsigned int bytes = PAGE_SIZE - offset;



		if (len <= 0)

			break;



		if (bytes > len)

			bytes = len;



		if (!is_vmalloc)

			page = virt_to_page(data);

		else

			page = vmalloc_to_page(data);

		if (bio_add_page(bio, page, bytes, offset) < bytes) {

			/* we don't support partial mappings */

		if (!bio_add_vmalloc(bio, data, len)) {

			bio_uninit(bio);

			kfree(bio);

			return ERR_PTR(-EINVAL);

		}



		data += bytes;

		len -= bytes;

		offset = 0;

	} else {

		bio_add_virt_nofail(bio, data, len);

	}



	bio->bi_end_io = bio_map_kern_endio;

	return bio;

}