[PATCH 1/2] block: introduce and export blk_rq_map_user_vec

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

Similiar to blk_rq_map_user except that it operates on iovec.
This is a prep patch.

Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
Signed-off-by: Anuj Gupta <anuj20.g@samsung.com>
---
 block/blk-map.c        | 19 +++++++++++++++++++
 include/linux/blk-mq.h |  2 ++
 2 files changed, 21 insertions(+)

diff --git a/block/blk-map.c b/block/blk-map.c
index 4526adde0156..7fe45df3e580 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -577,6 +577,25 @@ int blk_rq_map_user(struct request_queue *q, struct request *rq,
 }
 EXPORT_SYMBOL(blk_rq_map_user);
 
+int blk_rq_map_user_vec(struct request_queue *q, struct request *rq,
+		    struct rq_map_data *map_data, void __user *uvec,
+		    unsigned long nr_vecs, gfp_t gfp_mask)
+{
+	struct iovec fast_iov[UIO_FASTIOV];
+	struct iovec *iov = fast_iov;
+	struct iov_iter iter;
+	int ret;
+
+	ret = import_iovec(rq_data_dir(rq), uvec, nr_vecs, UIO_FASTIOV, &iov, &iter);
+	if (unlikely(ret < 0))
+		return ret;
+	ret = blk_rq_map_user_iov(q, rq, NULL, &iter, gfp_mask);
+	kfree(iov);
+
+	return ret;
+}
+EXPORT_SYMBOL(blk_rq_map_user_vec);
+
 /**
  * blk_rq_unmap_user - unmap a request with user data
  * @bio:	       start of bio list
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index d319ffa59354..0fda666d2230 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -966,6 +966,8 @@ struct rq_map_data {
 
 int blk_rq_map_user(struct request_queue *, struct request *,
 		struct rq_map_data *, void __user *, unsigned long, gfp_t);
+int blk_rq_map_user_vec(struct request_queue *, struct request *,
+		struct rq_map_data *, void __user *, unsigned long, gfp_t);
 int blk_rq_map_user_iov(struct request_queue *, struct request *,
 		struct rq_map_data *, const struct iov_iter *, gfp_t);
 int blk_rq_unmap_user(struct bio *);
-- 
2.25.1