If you want to lock the files during a release operation set the property useEditMode to true. The default value of this property is false.
mvn release:perform -DuseEditMode=true
This relies on release.properties being present from a previous release preparation. If this is not the case, you need to give the goal the name of the URL and optional tag to perform the release from. For example:
mvn release:perform -DuseEditMode=true -DconnectionUrl=scm:svn:https://svn.apache.org/repos/asf/maven/plugins/tags/maven-release-plugin-2.0
After the release is complete, the release.properties and other release files will be removed from the checkout.