def get_fsi(self, path):
        """
		returns a tuple of (fsi, relpath) if path is on a mountpoint.
		otherwise, return (None, path).
		fsi is a FSI which should be used for the action.
		relpath is a path which should be used as the path for FSI actions.
		"""
        path = os.path.abspath(path)
        i = None
        for p in self.path2fs:
            if path.startswith(p):
                i, readonly = self.path2fs[p]
                relpath = path.replace(p, "", 1)
                if not relpath.startswith("/"):
                    relpath = "/" + relpath
                return (i, relpath, readonly)
        return (None, path, False)

		returns a tuple of (fsi, relpath) if path is on a mountpoint.
		otherwise, return (None, path).
		fsi is a FSI which should be used for the action.
		relpath is a path which should be used as the path for FSI actions.
		
lib/stashutils/mount_manager.py