Commit 4d77007d authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: refactor get_contig_folio_len 



Move all of the logic to find the contigous length inside a folio into
get_contig_folio_len instead of keeping some of it in the caller.

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>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Tested-by: default avatarAnuj Gupta <anuj20.g@samsung.com>
Reviewed-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: default avatarAnuj Gupta <anuj20.g@samsung.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent fa0bdd45

block/bio.c

+27 −35
Original line number Diff line number Diff line
@@ -1172,33 +1172,35 @@ void bio_iov_bvec_set(struct bio *bio, const struct iov_iter *iter) 
	bio_set_flag(bio, BIO_CLONED);

}



static unsigned int get_contig_folio_len(unsigned int *num_pages,

					 struct page **pages, unsigned int i,

					 struct folio *folio, size_t left,

static unsigned int get_contig_folio_len(struct page **pages,

					 unsigned int *num_pages, size_t left,

					 size_t offset)

{

	size_t bytes = left;

	size_t contig_sz = min_t(size_t, PAGE_SIZE - offset, bytes);

	unsigned int j;

	struct folio *folio = page_folio(pages[0]);

	size_t contig_sz = min_t(size_t, PAGE_SIZE - offset, left);

	unsigned int max_pages, i;

	size_t folio_offset, len;



	folio_offset = PAGE_SIZE * folio_page_idx(folio, pages[0]) + offset;

	len = min(folio_size(folio) - folio_offset, left);



	/*

	 * We might COW a single page in the middle of

	 * a large folio, so we have to check that all

	 * pages belong to the same folio.

	 * We might COW a single page in the middle of a large folio, so we have

	 * to check that all pages belong to the same folio.

	 */

	bytes -= contig_sz;

	for (j = i + 1; j < i + *num_pages; j++) {

		size_t next = min_t(size_t, PAGE_SIZE, bytes);

	left -= contig_sz;

	max_pages = DIV_ROUND_UP(offset + len, PAGE_SIZE);

	for (i = 1; i < max_pages; i++) {

		size_t next = min_t(size_t, PAGE_SIZE, left);



		if (page_folio(pages[j]) != folio ||

		    pages[j] != pages[j - 1] + 1) {

		if (page_folio(pages[i]) != folio ||

		    pages[i] != pages[i - 1] + 1)

			break;

		}

		contig_sz += next;

		bytes -= next;

		left -= next;

	}

	*num_pages = j - i;



	*num_pages = i;

	return contig_sz;

}
@@ -1222,8 +1224,8 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) 
	struct bio_vec *bv = bio->bi_io_vec + bio->bi_vcnt;

	struct page **pages = (struct page **)bv;

	ssize_t size;

	unsigned int num_pages, i = 0;

	size_t offset, folio_offset, left, len;

	unsigned int i = 0;

	size_t offset, left, len;

	int ret = 0;



	/*
@@ -1244,23 +1246,12 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) 
		return size ? size : -EFAULT;



	nr_pages = DIV_ROUND_UP(offset + size, PAGE_SIZE);

	for (left = size, i = 0; left > 0; left -= len, i += num_pages) {

		struct page *page = pages[i];

		struct folio *folio = page_folio(page);

	for (left = size; left > 0; left -= len) {

		unsigned int old_vcnt = bio->bi_vcnt;

		unsigned int nr_to_add;



		folio_offset = ((size_t)folio_page_idx(folio, page) <<

			       PAGE_SHIFT) + offset;



		len = min(folio_size(folio) - folio_offset, left);



		num_pages = DIV_ROUND_UP(offset + len, PAGE_SIZE);



		if (num_pages > 1)

			len = get_contig_folio_len(&num_pages, pages, i,

						   folio, left, offset);



		if (!bio_add_folio(bio, folio, len, folio_offset)) {

		len = get_contig_folio_len(&pages[i], &nr_to_add, left, offset);

		if (!bio_add_page(bio, pages[i], len, offset)) {

			WARN_ON_ONCE(1);

			ret = -EINVAL;

			goto out;
@@ -1275,8 +1266,9 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) 
			 * single pin per page.

			 */

			if (offset && bio->bi_vcnt == old_vcnt)

				unpin_user_folio(folio, 1);

				unpin_user_folio(page_folio(pages[i]), 1);

		}

		i += nr_to_add;

		offset = 0;

	}