[SCSI] remove scsi_req_map_sg

No one uses scsi_execute_async with data transfer now. We can remove
scsi_req_map_sg.

Only scsi_eh_lock_door uses scsi_execute_async. scsi_eh_lock_door
doesn't handle sense and the callback. So we can remove
scsi_io_context too.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index ad6a137..0c2c73b 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -1441,6 +1441,11 @@
 	}
 }
 
+static void eh_lock_door_done(struct request *req, int uptodate)
+{
+	__blk_put_request(req->q, req);
+}
+
 /**
  * scsi_eh_lock_door - Prevent medium removal for the specified device
  * @sdev:	SCSI device to prevent medium removal
@@ -1463,20 +1468,29 @@
  */
 static void scsi_eh_lock_door(struct scsi_device *sdev)
 {
-	unsigned char cmnd[MAX_COMMAND_SIZE];
+	struct request *req;
 
-	cmnd[0] = ALLOW_MEDIUM_REMOVAL;
-	cmnd[1] = 0;
-	cmnd[2] = 0;
-	cmnd[3] = 0;
-	cmnd[4] = SCSI_REMOVAL_PREVENT;
-	cmnd[5] = 0;
+	req = blk_get_request(sdev->request_queue, READ, GFP_KERNEL);
+	if (!req)
+		return;
 
-	scsi_execute_async(sdev, cmnd, 6, DMA_NONE, NULL, 0, 0, 10 * HZ,
-			   5, NULL, NULL, GFP_KERNEL);
+	req->cmd[0] = ALLOW_MEDIUM_REMOVAL;
+	req->cmd[1] = 0;
+	req->cmd[2] = 0;
+	req->cmd[3] = 0;
+	req->cmd[4] = SCSI_REMOVAL_PREVENT;
+	req->cmd[5] = 0;
+
+	req->cmd_len = COMMAND_SIZE(req->cmd[0]);
+
+	req->cmd_type = REQ_TYPE_BLOCK_PC;
+	req->cmd_flags |= REQ_QUIET;
+	req->timeout = 10 * HZ;
+	req->retries = 5;
+
+	blk_execute_rq_nowait(req->q, NULL, req, 1, eh_lock_door_done);
 }
 
-
 /**
  * scsi_restart_operations - restart io operations to the specified host.
  * @shost:	Host we are restarting.