Commit 1cb9dda4 authored by Kent Overstreet's avatar Kent Overstreet
Browse files

block: Convert bio_copy_data() to bvec_iter 



Our fancy new bvec iterator makes code like this much easier to write.

Signed-off-by: default avatarKent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
parent 4550dd6c

fs/bio.c

+25 −35
Original line number Diff line number Diff line
@@ -852,58 +852,48 @@ EXPORT_SYMBOL(bio_alloc_pages); 
 */

void bio_copy_data(struct bio *dst, struct bio *src)

{

	struct bio_vec *src_bv, *dst_bv;

	unsigned src_offset, dst_offset, bytes;

	struct bvec_iter src_iter, dst_iter;

	struct bio_vec src_bv, dst_bv;

	void *src_p, *dst_p;

	unsigned bytes;



	src_bv = __bio_iovec(src);

	dst_bv = __bio_iovec(dst);



	src_offset = src_bv->bv_offset;

	dst_offset = dst_bv->bv_offset;

	src_iter = src->bi_iter;

	dst_iter = dst->bi_iter;



	while (1) {

		if (src_offset == src_bv->bv_offset + src_bv->bv_len) {

			src_bv++;

			if (src_bv == bio_iovec_idx(src, src->bi_vcnt)) {

		if (!src_iter.bi_size) {

			src = src->bi_next;

			if (!src)

				break;



				src_bv = __bio_iovec(src);

			}



			src_offset = src_bv->bv_offset;

			src_iter = src->bi_iter;

		}



		if (dst_offset == dst_bv->bv_offset + dst_bv->bv_len) {

			dst_bv++;

			if (dst_bv == bio_iovec_idx(dst, dst->bi_vcnt)) {

		if (!dst_iter.bi_size) {

			dst = dst->bi_next;

			if (!dst)

				break;



				dst_bv = __bio_iovec(dst);

			dst_iter = dst->bi_iter;

		}



			dst_offset = dst_bv->bv_offset;

		}

		src_bv = bio_iter_iovec(src, src_iter);

		dst_bv = bio_iter_iovec(dst, dst_iter);



		bytes = min(dst_bv->bv_offset + dst_bv->bv_len - dst_offset,

			    src_bv->bv_offset + src_bv->bv_len - src_offset);

		bytes = min(src_bv.bv_len, dst_bv.bv_len);



		src_p = kmap_atomic(src_bv->bv_page);

		dst_p = kmap_atomic(dst_bv->bv_page);

		src_p = kmap_atomic(src_bv.bv_page);

		dst_p = kmap_atomic(dst_bv.bv_page);



		memcpy(dst_p + dst_offset,

		       src_p + src_offset,

		memcpy(dst_p + dst_bv.bv_offset,

		       src_p + src_bv.bv_offset,

		       bytes);



		kunmap_atomic(dst_p);

		kunmap_atomic(src_p);



		src_offset += bytes;

		dst_offset += bytes;

		bio_advance_iter(src, &src_iter, bytes);

		bio_advance_iter(dst, &dst_iter, bytes);

	}

}

EXPORT_SYMBOL(bio_copy_data);