Commit 480cb846 authored by Al Viro's avatar Al Viro
Browse files

block: convert to advancing variants of iov_iter_get_pages{,_alloc}() 



... doing revert if we end up not using some pages

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 1ef255e2

block/bio.c

+14 −11
Original line number Diff line number Diff line
@@ -1200,7 +1200,7 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) 
	struct page **pages = (struct page **)bv;

	ssize_t size, left;

	unsigned len, i = 0;

	size_t offset;

	size_t offset, trim;

	int ret = 0;



	/*
@@ -1218,16 +1218,19 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) 
	 * result to ensure the bio's total size is correct. The remainder of

	 * the iov data will be picked up in the next bio iteration.

	 */

	size = iov_iter_get_pages(iter, pages, UINT_MAX - bio->bi_iter.bi_size,

	size = iov_iter_get_pages2(iter, pages, UINT_MAX - bio->bi_iter.bi_size,

				  nr_pages, &offset);

	if (size > 0) {

	if (unlikely(size <= 0))

		return size ? size : -EFAULT;



	nr_pages = DIV_ROUND_UP(offset + size, PAGE_SIZE);

		size = ALIGN_DOWN(size, bdev_logical_block_size(bio->bi_bdev));

	} else

		nr_pages = 0;



	if (unlikely(size <= 0)) {

		ret = size ? size : -EFAULT;

	trim = size & (bdev_logical_block_size(bio->bi_bdev) - 1);

	iov_iter_revert(iter, trim);



	size -= trim;

	if (unlikely(!size)) {

		ret = -EFAULT;

		goto out;

	}
@@ -1246,7 +1249,7 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) 
		offset = 0;

	}



	iov_iter_advance(iter, size - left);

	iov_iter_revert(iter, left);

out:

	while (i < nr_pages)

		put_page(pages[i++]);

block/blk-map.c

+4 −3
Original line number Diff line number Diff line
@@ -254,7 +254,7 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter, 
		size_t offs, added = 0;

		int npages;



		bytes = iov_iter_get_pages_alloc(iter, &pages, LONG_MAX, &offs);

		bytes = iov_iter_get_pages_alloc2(iter, &pages, LONG_MAX, &offs);

		if (unlikely(bytes <= 0)) {

			ret = bytes ? bytes : -EFAULT;

			goto out_unmap;
@@ -284,7 +284,6 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter, 
				bytes -= n;

				offs = 0;

			}

			iov_iter_advance(iter, added);

		}

		/*

		 * release the pages we didn't map into the bio, if any
@@ -293,9 +292,11 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter, 
			put_page(pages[j++]);

		kvfree(pages);

		/* couldn't stuff something into bio? */

		if (bytes)

		if (bytes) {

			iov_iter_revert(iter, bytes);

			break;

		}

	}



	ret = blk_rq_append_bio(rq, bio);

	if (ret)