Error in unloading directory

[root@localhost ~]# umount /usr/geoc
umount.nfs4: /usr/geoc: device is busy

Method 1: fuser -m -v /data_nas/
USER PID ACCESS COMMAND
as: root kernel mount /mnt
root 7088 ..c.. bash
admin 7145 ..c.. bash

#Method 2:
umount -l /data_nas

#Method 3:
fuser -km /data_nas

Solution:

Recommend Method 1