From 480cb846c27bda4e14d98a45a9f50c250f38f266 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 9 Jun 2022 10:37:57 -0400 Subject: block: convert to advancing variants of iov_iter_get_pages{,_alloc}() ... doing revert if we end up not using some pages Signed-off-by: Al Viro --- block/bio.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) (limited to 'block/bio.c') diff --git a/block/bio.c b/block/bio.c index d6eb90d9b20b..3d3a2678fea2 100644 --- a/block/bio.c +++ b/block/bio.c @@ -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) { - 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; + if (unlikely(size <= 0)) + return size ? size : -EFAULT; + + nr_pages = DIV_ROUND_UP(offset + size, PAGE_SIZE); + + 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++]); -- cgit