[RFC PATCH 3/4] block: modify bio_integrity_map_user to accept iov_iter as argument

[Kanchan Joshi <joshi.k@samsung.com>]

From: Anuj Gupta <anuj20.g@samsung.com>

Refactor bio_integrity_map_user to accept iov_iter as
argument. This is a prep patch.

Signed-off-by: Anuj Gupta <anuj20.g@samsung.com>
Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
---
 block/bio-integrity.c     | 14 ++++++--------
 drivers/nvme/host/ioctl.c | 11 +++++++++--
 include/linux/bio.h       |  7 ++++---
 3 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index 2e3e8e04961e..e340b5a03cdf 100644
--- a/block/bio-integrity.c
+++ b/block/bio-integrity.c
@@ -308,17 +308,16 @@ static unsigned int bvec_from_pages(struct bio_vec *bvec, struct page **pages,
 	return nr_bvecs;
 }
 
-int bio_integrity_map_user(struct bio *bio, void __user *ubuf, ssize_t bytes,
-			   u32 seed)
+int bio_integrity_map_user(struct bio *bio, struct iov_iter *iter,
+			  u32 seed)
 {
 	struct request_queue *q = bdev_get_queue(bio->bi_bdev);
 	unsigned int align = q->dma_pad_mask | queue_dma_alignment(q);
 	struct page *stack_pages[UIO_FASTIOV], **pages = stack_pages;
 	struct bio_vec stack_vec[UIO_FASTIOV], *bvec = stack_vec;
+	size_t offset, bytes = iter->count;
 	unsigned int direction, nr_bvecs;
-	struct iov_iter iter;
 	int ret, nr_vecs;
-	size_t offset;
 	bool copy;
 
 	if (bio_integrity(bio))
@@ -331,8 +330,7 @@ int bio_integrity_map_user(struct bio *bio, void __user *ubuf, ssize_t bytes,
 	else
 		direction = ITER_SOURCE;
 
-	iov_iter_ubuf(&iter, direction, ubuf, bytes);
-	nr_vecs = iov_iter_npages(&iter, BIO_MAX_VECS + 1);
+	nr_vecs = iov_iter_npages(iter, BIO_MAX_VECS + 1);
 	if (nr_vecs > BIO_MAX_VECS)
 		return -E2BIG;
 	if (nr_vecs > UIO_FASTIOV) {
@@ -342,8 +340,8 @@ int bio_integrity_map_user(struct bio *bio, void __user *ubuf, ssize_t bytes,
 		pages = NULL;
 	}
 
-	copy = !iov_iter_is_aligned(&iter, align, align);
-	ret = iov_iter_extract_pages(&iter, &pages, bytes, nr_vecs, 0, &offset);
+	copy = !iov_iter_is_aligned(iter, align, align);
+	ret = iov_iter_extract_pages(iter, &pages, bytes, nr_vecs, 0, &offset);
 	if (unlikely(ret < 0))
 		goto free_bvec;
 
diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
index 3dfd5ae99ae0..deee13000f08 100644
--- a/drivers/nvme/host/ioctl.c
+++ b/drivers/nvme/host/ioctl.c
@@ -145,8 +145,15 @@ static int nvme_map_user_request(struct request *req, u64 ubuffer,
 	if (bdev) {
 		bio_set_dev(bio, bdev);
 		if (meta_buffer && meta_len) {
-			ret = bio_integrity_map_user(bio, meta_buffer, meta_len,
-						     meta_seed);
+			struct iov_iter iter;
+			unsigned int direction;
+
+			if (bio_data_dir(bio) == READ)
+				direction = ITER_DEST;
+			else
+				direction = ITER_SOURCE;
+			iov_iter_ubuf(&iter, direction, meta_buffer, meta_len);
+			ret = bio_integrity_map_user(bio, &iter, meta_seed);
 			if (ret)
 				goto out_unmap;
 			req->cmd_flags |= REQ_INTEGRITY;
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 875d792bffff..20cf47fc851f 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -723,7 +723,7 @@ static inline bool bioset_initialized(struct bio_set *bs)
 	for_each_bio(_bio)						\
 		bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
 
-int bio_integrity_map_user(struct bio *bio, void __user *ubuf, ssize_t len, u32 seed);
+int bio_integrity_map_user(struct bio *bio, struct iov_iter *iter, u32 seed);
 extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
 extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
 extern bool bio_integrity_prep(struct bio *);
@@ -795,8 +795,9 @@ static inline int bio_integrity_add_page(struct bio *bio, struct page *page,
 	return 0;
 }
 
-static inline int bio_integrity_map_user(struct bio *bio, void __user *ubuf,
-					 ssize_t len, u32 seed)
+static inline int bio_integrity_map_user(struct bio *bio, struct iov_iter *iter,
+					u32 seed)
+
 {
 	return -EINVAL;
 }
-- 
2.25.1