How to check what service is using a particular configuration file?

I'm new to Linux, and I need to know if there is a way to check which service or program is using a particular configuration file. A different deployment on the server is failing, and the error message is:

file /opt/deployment/dev/deploy.cfg busy

This means that the file deploy.cfg is busy. 1. How may I tell who or what keeps the file busy. 2. How would I make the file "not busy".