Commit c58c0074 authored by Keith Busch's avatar Keith Busch Committed by Jens Axboe
Browse files

block/bio: remove duplicate append pages code 



The getting pages setup for zone append and normal IO are identical. Use
common code for each.

Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220610195830.3574005-3-kbusch@fb.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent b82d9fa2

block/bio.c

+42 −60
Original line number Diff line number Diff line
@@ -1159,6 +1159,37 @@ static void bio_put_pages(struct page **pages, size_t size, size_t off) 
		put_page(pages[i]);

}



static int bio_iov_add_page(struct bio *bio, struct page *page,

		unsigned int len, unsigned int offset)

{

	bool same_page = false;



	if (!__bio_try_merge_page(bio, page, len, offset, &same_page)) {

		if (WARN_ON_ONCE(bio_full(bio, len)))

			return -EINVAL;

		__bio_add_page(bio, page, len, offset);

		return 0;

	}



	if (same_page)

		put_page(page);

	return 0;

}



static int bio_iov_add_zone_append_page(struct bio *bio, struct page *page,

		unsigned int len, unsigned int offset)

{

	struct request_queue *q = bdev_get_queue(bio->bi_bdev);

	bool same_page = false;



	if (bio_add_hw_page(q, bio, page, len, offset,

			queue_max_zone_append_sectors(q), &same_page) != len)

		return -EINVAL;

	if (same_page)

		put_page(page);

	return 0;

}



#define PAGE_PTRS_PER_BVEC     (sizeof(struct bio_vec) / sizeof(struct page *))



/**
@@ -1177,7 +1208,6 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) 
	unsigned short entries_left = bio->bi_max_vecs - bio->bi_vcnt;

	struct bio_vec *bv = bio->bi_io_vec + bio->bi_vcnt;

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

	bool same_page = false;

	ssize_t size, left;

	unsigned len, i;

	size_t offset;
@@ -1196,18 +1226,18 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) 


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

		struct page *page = pages[i];

		int ret;



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

		if (bio_op(bio) == REQ_OP_ZONE_APPEND)

			ret = bio_iov_add_zone_append_page(bio, page, len,

					offset);

		else

			ret = bio_iov_add_page(bio, page, len, offset);



		if (__bio_try_merge_page(bio, page, len, offset, &same_page)) {

			if (same_page)

				put_page(page);

		} else {

			if (WARN_ON_ONCE(bio_full(bio, len))) {

		if (ret) {

			bio_put_pages(pages + i, left, offset);

				return -EINVAL;

			}

			__bio_add_page(bio, page, len, offset);

			return ret;

		}

		offset = 0;

	}
@@ -1216,51 +1246,6 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) 
	return 0;

}



static int __bio_iov_append_get_pages(struct bio *bio, struct iov_iter *iter)

{

	unsigned short nr_pages = bio->bi_max_vecs - bio->bi_vcnt;

	unsigned short entries_left = bio->bi_max_vecs - bio->bi_vcnt;

	struct request_queue *q = bdev_get_queue(bio->bi_bdev);

	unsigned int max_append_sectors = queue_max_zone_append_sectors(q);

	struct bio_vec *bv = bio->bi_io_vec + bio->bi_vcnt;

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

	ssize_t size, left;

	unsigned len, i;

	size_t offset;

	int ret = 0;



	/*

	 * Move page array up in the allocated memory for the bio vecs as far as

	 * possible so that we can start filling biovecs from the beginning

	 * without overwriting the temporary page array.

	 */

	BUILD_BUG_ON(PAGE_PTRS_PER_BVEC < 2);

	pages += entries_left * (PAGE_PTRS_PER_BVEC - 1);



	size = iov_iter_get_pages(iter, pages, LONG_MAX, nr_pages, &offset);

	if (unlikely(size <= 0))

		return size ? size : -EFAULT;



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

		struct page *page = pages[i];

		bool same_page = false;



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

		if (bio_add_hw_page(q, bio, page, len, offset,

				max_append_sectors, &same_page) != len) {

			bio_put_pages(pages + i, left, offset);

			ret = -EINVAL;

			break;

		}

		if (same_page)

			put_page(page);

		offset = 0;

	}



	iov_iter_advance(iter, size - left);

	return ret;

}



/**

 * bio_iov_iter_get_pages - add user or kernel pages to a bio

 * @bio: bio to add pages to
@@ -1295,9 +1280,6 @@ int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) 
	}



	do {

		if (bio_op(bio) == REQ_OP_ZONE_APPEND)

			ret = __bio_iov_append_get_pages(bio, iter);

		else

		ret = __bio_iov_iter_get_pages(bio, iter);

	} while (!ret && iov_iter_count(iter) && !bio_full(bio, 0));