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()
866 				STps->drv_block = 0;  in flush_buffer()
874 		STps->drv_block = 0;  in flush_buffer()
945 		STps->drv_block = -1;  in reset_state()
1081 			STps->drv_block = 0;  in check_tape()
1098 			STp->ps[0].drv_file = STp->ps[0].drv_block = (-1);  in check_tape()
1404 			STps->drv_block = 0;  in st_flush()
1429 					STps->drv_block = 0;  in st_flush()
1439 			STps->drv_block = 0;  in st_flush()
1665 		   STps->drv_file == 0 && STps->drv_block == 0) {  in st_write()
1830 						if (STps->drv_block >= 0) {  in st_write()
1831 							STps->drv_block += (transfer - undone) /  in st_write()
1847 						STps->drv_block = (-1); /* Too cautious? */  in st_write()
1855 				STps->drv_block = (-1);		/* Too cautious? */  in st_write()
1861 		if (STps->drv_block >= 0) {  in st_write()
1863 				STps->drv_block += (do_count > 0);  in st_write()
1865 				STps->drv_block += blks;  in st_write()
1990 						if (STps->drv_block >= 0)  in read_tape()
1991 							STps->drv_block += 1;  in read_tape()
2003 							if (STps->drv_block >= 0)  in read_tape()
2004 								STps->drv_block += blks - transfer + 1;  in read_tape()
2016 						if (STps->drv_block >= 0)  in read_tape()
2017 							STps->drv_block += 1;  in read_tape()
2053 				STps->drv_block = (-1);  in read_tape()
2080 	if (STps->drv_block >= 0) {  in read_tape()
2082 			STps->drv_block++;  in read_tape()
2084 			STps->drv_block += STbp->buffer_bytes / STp->block_size;  in read_tape()
2209 			STps->drv_block = 0;  in st_read()
2214 			STps->drv_block = 0;  in st_read()
2663 		STps->drv_file = STps->drv_block = (-1);  in do_load_unload()
2716 	blkno = STps->drv_block;  in st_int_ioctl()
2965 		STps->drv_block = blkno;  in st_int_ioctl()
3005 			STps->drv_block = 0;  in st_int_ioctl()
3032 			STps->drv_block = -1;  in st_int_ioctl()
3039 			STps->drv_block = 0;  in st_int_ioctl()
3045 				STps->drv_block = 0;  in st_int_ioctl()
3049 					STps->drv_block = blkno - undone;  in st_int_ioctl()
3051 					STps->drv_block = (-1);  in st_int_ioctl()
3057 				STps->drv_block = (-1);  in st_int_ioctl()
3061 				if (STps->drv_block >= 0)  in st_int_ioctl()
3062 					STps->drv_block = blkno + undone;  in st_int_ioctl()
3067 			STps->drv_block = (-1);  in st_int_ioctl()
3145 				STp->ps[0].drv_block = STp->ps[0].drv_file = 0;  in get_location()
3228 	STps->drv_block = STps->drv_file = (-1);  in set_location()
3248 			STps->drv_block = STps->drv_file = 0;  in set_location()
3585 			STps->drv_block = STps->drv_file = 0;  in st_ioctl()
3652 		mt_status.mt_blkno = STps->drv_block;  in st_ioctl()
4258 		STps->drv_block = (-1);  in st_probe()