635 	if (STps->drv_block >= 0) {  in write_behind_check()
637 			STps->drv_block++;  in write_behind_check()
639 			STps->drv_block += STbuffer->writing / STp->block_size;  in write_behind_check()
655 			STps->drv_block = -1;  in write_behind_check()
750 				if (STps->drv_block >= 0)  in st_flush_write_buffer()
751 					STps->drv_block += blks;  in st_flush_write_buffer()
755 				STps->drv_block = (-1);  in st_flush_write_buffer()
759 			if (STps->drv_block >= 0)  in st_flush_write_buffer()
760 				STps->drv_block += blks;  in st_flush_write_buffer()
812 				STps->drv_block = 0;  in flush_buffer()
820 		STps->drv_block = 0;  in flush_buffer()
891 		STps->drv_block = -1;  in reset_state()
1027 			STps->drv_block = 0;  in check_tape()
1044 			STp->ps[0].drv_file = STp->ps[0].drv_block = (-1);  in check_tape()
1350 			STps->drv_block = 0;  in st_flush()
1375 					STps->drv_block = 0;  in st_flush()
1385 			STps->drv_block = 0;  in st_flush()
1611 		   STps->drv_file == 0 && STps->drv_block == 0) {  in st_write()
1776 						if (STps->drv_block >= 0) {  in st_write()
1777 							STps->drv_block += (transfer - undone) /  in st_write()
1793 						STps->drv_block = (-1); /* Too cautious? */  in st_write()
1801 				STps->drv_block = (-1);		/* Too cautious? */  in st_write()
1807 		if (STps->drv_block >= 0) {  in st_write()
1809 				STps->drv_block += (do_count > 0);  in st_write()
1811 				STps->drv_block += blks;  in st_write()
1936 						if (STps->drv_block >= 0)  in read_tape()
1937 							STps->drv_block += 1;  in read_tape()
1949 							if (STps->drv_block >= 0)  in read_tape()
1950 								STps->drv_block += blks - transfer + 1;  in read_tape()
1962 						if (STps->drv_block >= 0)  in read_tape()
1963 							STps->drv_block += 1;  in read_tape()
1999 				STps->drv_block = (-1);  in read_tape()
2026 	if (STps->drv_block >= 0) {  in read_tape()
2028 			STps->drv_block++;  in read_tape()
2030 			STps->drv_block += STbp->buffer_bytes / STp->block_size;  in read_tape()
2155 			STps->drv_block = 0;  in st_read()
2160 			STps->drv_block = 0;  in st_read()
2609 		STps->drv_file = STps->drv_block = (-1);  in do_load_unload()
2662 	blkno = STps->drv_block;  in st_int_ioctl()
2911 		STps->drv_block = blkno;  in st_int_ioctl()
2951 			STps->drv_block = 0;  in st_int_ioctl()
2978 			STps->drv_block = -1;  in st_int_ioctl()
2985 			STps->drv_block = 0;  in st_int_ioctl()
2991 				STps->drv_block = 0;  in st_int_ioctl()
2995 					STps->drv_block = blkno - undone;  in st_int_ioctl()
2997 					STps->drv_block = (-1);  in st_int_ioctl()
3003 				STps->drv_block = (-1);  in st_int_ioctl()
3007 				if (STps->drv_block >= 0)  in st_int_ioctl()
3008 					STps->drv_block = blkno + undone;  in st_int_ioctl()
3013 			STps->drv_block = (-1);  in st_int_ioctl()
3091 				STp->ps[0].drv_block = STp->ps[0].drv_file = 0;  in get_location()
3174 	STps->drv_block = STps->drv_file = (-1);  in set_location()
3194 			STps->drv_block = STps->drv_file = 0;  in set_location()
3531 			STps->drv_block = STps->drv_file = 0;  in st_ioctl()
3598 		mt_status.mt_blkno = STps->drv_block;  in st_ioctl()
4203 		STps->drv_block = (-1);  in st_probe()