689 	if (STps->drv_block >= 0) {  in write_behind_check()
691 			STps->drv_block++;  in write_behind_check()
693 			STps->drv_block += STbuffer->writing / STp->block_size;  in write_behind_check()
709 			STps->drv_block = -1;  in write_behind_check()
804 				if (STps->drv_block >= 0)  in st_flush_write_buffer()
805 					STps->drv_block += blks;  in st_flush_write_buffer()
809 				STps->drv_block = (-1);  in st_flush_write_buffer()
813 			if (STps->drv_block >= 0)  in st_flush_write_buffer()
814 				STps->drv_block += blks;  in st_flush_write_buffer()
863 				STps->drv_block = 0;  in flush_buffer()
871 		STps->drv_block = 0;  in flush_buffer()
942 		STps->drv_block = -1;  in reset_state()
1078 			STps->drv_block = 0;  in check_tape()
1095 			STp->ps[0].drv_file = STp->ps[0].drv_block = (-1);  in check_tape()
1401 			STps->drv_block = 0;  in st_flush()
1426 					STps->drv_block = 0;  in st_flush()
1436 			STps->drv_block = 0;  in st_flush()
1661 		   STps->drv_file == 0 && STps->drv_block == 0) {  in st_write()
1826 						if (STps->drv_block >= 0) {  in st_write()
1827 							STps->drv_block += (transfer - undone) /  in st_write()
1843 						STps->drv_block = (-1); /* Too cautious? */  in st_write()
1851 				STps->drv_block = (-1);		/* Too cautious? */  in st_write()
1857 		if (STps->drv_block >= 0) {  in st_write()
1859 				STps->drv_block += (do_count > 0);  in st_write()
1861 				STps->drv_block += blks;  in st_write()
1989 						if (STps->drv_block >= 0)  in read_tape()
1990 							STps->drv_block += 1;  in read_tape()
2002 							if (STps->drv_block >= 0)  in read_tape()
2003 								STps->drv_block += blks - transfer + 1;  in read_tape()
2015 						if (STps->drv_block >= 0)  in read_tape()
2016 							STps->drv_block += 1;  in read_tape()
2052 				STps->drv_block = (-1);  in read_tape()
2079 	if (STps->drv_block >= 0) {  in read_tape()
2081 			STps->drv_block++;  in read_tape()
2083 			STps->drv_block += STbp->buffer_bytes / STp->block_size;  in read_tape()
2208 			STps->drv_block = 0;  in st_read()
2213 			STps->drv_block = 0;  in st_read()
2662 		STps->drv_file = STps->drv_block = (-1);  in do_load_unload()
2714 	blkno = STps->drv_block;  in st_int_ioctl()
2964 		STps->drv_block = blkno;  in st_int_ioctl()
3004 			STps->drv_block = 0;  in st_int_ioctl()
3031 			STps->drv_block = -1;  in st_int_ioctl()
3038 			STps->drv_block = 0;  in st_int_ioctl()
3044 				STps->drv_block = 0;  in st_int_ioctl()
3048 					STps->drv_block = blkno - undone;  in st_int_ioctl()
3050 					STps->drv_block = (-1);  in st_int_ioctl()
3056 				STps->drv_block = (-1);  in st_int_ioctl()
3060 				if (STps->drv_block >= 0)  in st_int_ioctl()
3061 					STps->drv_block = blkno + undone;  in st_int_ioctl()
3066 			STps->drv_block = (-1);  in st_int_ioctl()
3144 				STp->ps[0].drv_block = STp->ps[0].drv_file = 0;  in get_location()
3227 	STps->drv_block = STps->drv_file = (-1);  in set_location()
3247 			STps->drv_block = STps->drv_file = 0;  in set_location()
3684 			STps->drv_block = STps->drv_file = 0;  in st_ioctl()
3751 		mt_status.mt_blkno = STps->drv_block;  in st_ioctl()
4332 		STps->drv_block = (-1);  in st_probe()