--- b/sys/cam/scsi/scsi_sg.c	
+++ b/sys/cam/scsi/scsi_sg.c	
@@ -553,6 +553,8 @@ sgioctl(struct cdev *dev, u_long cmd, caddr_t arg, int flag, struct thread *td)
 		}
 
 		if (req->dxfer_len > MAXPHYS) {
+			printf("%s: dxfer_len (%u) > MAXPHYS (%u)\n",
+			    __func__, req->dxfer_len, MAXPHYS);
 			error = EINVAL;
 			break;
 		}
@@ -578,7 +580,7 @@ sgioctl(struct cdev *dev, u_long cmd, caddr_t arg, int flag, struct thread *td)
 			dir = CAM_DIR_IN;
 			break;
 		case SG_DXFER_TO_FROM_DEV:
-			dir = CAM_DIR_BOTH;
+			dir = CAM_DIR_IN | CAM_DIR_OUT;
 			break;
 		case SG_DXFER_NONE:
 		default:
@@ -586,7 +588,7 @@ sgioctl(struct cdev *dev, u_long cmd, caddr_t arg, int flag, struct thread *td)
 			break;
 		}
 
-		if (dir == CAM_DIR_IN || dir == CAM_DIR_BOTH) {
+		if (dir & CAM_DIR_IN) {
 			error = copyin(req->dxferp, data_ptr, req->dxfer_len);
 			if (error) {
 				free(data_ptr, M_DEVBUF);
@@ -629,7 +631,7 @@ sgioctl(struct cdev *dev, u_long cmd, caddr_t arg, int flag, struct thread *td)
 					req->sb_len_wr);
 		}
 
-		if ((dir == CAM_DIR_OUT || dir == CAM_DIR_BOTH) && error == 0)
+		if ((dir & CAM_DIR_OUT) && error == 0)
 			error = copyout(data_ptr, req->dxferp, req->dxfer_len);
 
 		free(data_ptr, M_DEVBUF);