690 	if (STps->drv_block >= 0) {  in write_behind_check()
692 			STps->drv_block++;  in write_behind_check()
694 			STps->drv_block += STbuffer->writing / STp->block_size;  in write_behind_check()
710 			STps->drv_block = -1;  in write_behind_check()
805 				if (STps->drv_block >= 0)  in st_flush_write_buffer()
806 					STps->drv_block += blks;  in st_flush_write_buffer()
810 				STps->drv_block = (-1);  in st_flush_write_buffer()
814 			if (STps->drv_block >= 0)  in st_flush_write_buffer()
815 				STps->drv_block += blks;  in st_flush_write_buffer()
864 				STps->drv_block = 0;  in flush_buffer()
872 		STps->drv_block = 0;  in flush_buffer()
943 		STps->drv_block = -1;  in reset_state()
1079 			STps->drv_block = 0;  in check_tape()
1096 			STp->ps[0].drv_file = STp->ps[0].drv_block = (-1);  in check_tape()
1402 			STps->drv_block = 0;  in st_flush()
1427 					STps->drv_block = 0;  in st_flush()
1437 			STps->drv_block = 0;  in st_flush()
1663 		   STps->drv_file == 0 && STps->drv_block == 0) {  in st_write()
1828 						if (STps->drv_block >= 0) {  in st_write()
1829 							STps->drv_block += (transfer - undone) /  in st_write()
1845 						STps->drv_block = (-1); /* Too cautious? */  in st_write()
1853 				STps->drv_block = (-1);		/* Too cautious? */  in st_write()
1859 		if (STps->drv_block >= 0) {  in st_write()
1861 				STps->drv_block += (do_count > 0);  in st_write()
1863 				STps->drv_block += blks;  in st_write()
1991 						if (STps->drv_block >= 0)  in read_tape()
1992 							STps->drv_block += 1;  in read_tape()
2004 							if (STps->drv_block >= 0)  in read_tape()
2005 								STps->drv_block += blks - transfer + 1;  in read_tape()
2017 						if (STps->drv_block >= 0)  in read_tape()
2018 							STps->drv_block += 1;  in read_tape()
2054 				STps->drv_block = (-1);  in read_tape()
2081 	if (STps->drv_block >= 0) {  in read_tape()
2083 			STps->drv_block++;  in read_tape()
2085 			STps->drv_block += STbp->buffer_bytes / STp->block_size;  in read_tape()
2210 			STps->drv_block = 0;  in st_read()
2215 			STps->drv_block = 0;  in st_read()
2664 		STps->drv_file = STps->drv_block = (-1);  in do_load_unload()
2717 	blkno = STps->drv_block;  in st_int_ioctl()
2966 		STps->drv_block = blkno;  in st_int_ioctl()
3006 			STps->drv_block = 0;  in st_int_ioctl()
3033 			STps->drv_block = -1;  in st_int_ioctl()
3040 			STps->drv_block = 0;  in st_int_ioctl()
3046 				STps->drv_block = 0;  in st_int_ioctl()
3050 					STps->drv_block = blkno - undone;  in st_int_ioctl()
3052 					STps->drv_block = (-1);  in st_int_ioctl()
3058 				STps->drv_block = (-1);  in st_int_ioctl()
3062 				if (STps->drv_block >= 0)  in st_int_ioctl()
3063 					STps->drv_block = blkno + undone;  in st_int_ioctl()
3068 			STps->drv_block = (-1);  in st_int_ioctl()
3146 				STp->ps[0].drv_block = STp->ps[0].drv_file = 0;  in get_location()
3229 	STps->drv_block = STps->drv_file = (-1);  in set_location()
3249 			STps->drv_block = STps->drv_file = 0;  in set_location()
3686 			STps->drv_block = STps->drv_file = 0;  in st_ioctl()
3753 		mt_status.mt_blkno = STps->drv_block;  in st_ioctl()
4359 		STps->drv_block = (-1);  in st_probe()