block: ublk_drv: add two helpers to clean up map/unmap request

Add two helpers for checking if map/unmap is needed, since we may have
passthrough request which needs map or unmap in future, such as for
supporting report zones.

Meantime don't mark ublk_copy_user_pages as inline since this function
is a bit fat now.
Reviewed-by: Ziyang Zhang <ZiyangZhang@linux.alibaba.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/ublk_drv.c

@@ -488,8 +488,7 @@ static inline unsigned ublk_copy_io_pages(struct ublk_io_iter *data,
 	return done;
 }
 
-static inline int ublk_copy_user_pages(struct ublk_map_data *data,
-		bool to_vm)
+static int ublk_copy_user_pages(struct ublk_map_data *data, bool to_vm)
 {
 	const unsigned int gup_flags = to_vm ? FOLL_WRITE : 0;
 	const unsigned long start_vm = data->io->addr;
@@ -525,6 +524,16 @@ static inline int ublk_copy_user_pages(struct ublk_map_data *data,
 	return done;
 }
 
+static inline bool ublk_need_map_req(const struct request *req)
+{
+	return ublk_rq_has_data(req) && req_op(req) == REQ_OP_WRITE;
+}
+
+static inline bool ublk_need_unmap_req(const struct request *req)
+{
+	return ublk_rq_has_data(req) && req_op(req) == REQ_OP_READ;
+}
+
 static int ublk_map_io(const struct ublk_queue *ubq, const struct request *req,
 		struct ublk_io *io)
 {
@@ -535,7 +544,7 @@ static int ublk_map_io(const struct ublk_queue *ubq, const struct request *req,
 	 * context and the big benefit is that pinning pages in current
 	 * context is pretty fast, see ublk_pin_user_pages
 	 */
-	if (ublk_rq_has_data(req) && req_op(req) == REQ_OP_WRITE) {
+	if (ublk_need_map_req(req)) {
 		struct ublk_map_data data = {
 			.ubq	=	ubq,
 			.rq	=	req,
@@ -556,7 +565,7 @@ static int ublk_unmap_io(const struct ublk_queue *ubq,
 {
 	const unsigned int rq_bytes = blk_rq_bytes(req);
 
-	if (req_op(req) == REQ_OP_READ && ublk_rq_has_data(req)) {
+	if (ublk_need_unmap_req(req)) {
 		struct ublk_map_data data = {
 			.ubq	=	ubq,
 			.rq	=	req,
@@ -770,7 +779,7 @@ static inline void __ublk_rq_task_work(struct request *req)
 		return;
 	}
 
-	if (ublk_need_get_data(ubq) && (req_op(req) == REQ_OP_WRITE)) {
+	if (ublk_need_get_data(ubq) && ublk_need_map_req(req)) {
 		/*
 		 * We have not handled UBLK_IO_NEED_GET_DATA command yet,
 		 * so immepdately pass UBLK_IO_RES_NEED_GET_DATA to ublksrv