Since a filesystem resource manager may potentially receive long pathnames, it must be able to parse and handle each component of the path properly.
Let's say that a resource manager registers the mountpoint /mount/, and a user types:
ls -l /mount/home
where /mount/home is a directory on the device. The ls utility does the following:
d = opendir("/mount/home"); while (...) { dirent = readdir(d); ... }