How do I forcefully close files from FSD?

Hi,
Hi,

I have a file system that manages licenses and license timeouts. I start
a timer when the user first opens a file. I reset timer for every
activity on the volume for the particular user. I want to close the
opened file from my FSD, when there is no activity for the specified
time (when the timer expires). Any suggestions how to do this or hints
will be helpful.

Thank you,

Regards,
Bala