Hm. Is the root directory is one of the mount points being scanned?

or, more generally, if you have a mounted directory that has further mount points within it on which further stuff has been mounted, then the latter stuff is going to get scanned (at least) twice unless you're doing something to prune it out during the scan of the parent mount (or mark it somehow as done so that you know to skip it if you encounter that same directory again later on)

(... unless File::find is way smarter than I think it is)