Function ds::visit_dirs

pub fn visit_dirs(
    dir: PathBuf, 
    mds: &mut Mutex<BTreeMap<String, u64>>, 
    ve: &mut VerboseErrors, 
    fd: &mut FilesystemDevice
) -> Result<(), DSError>

Visit_Dirs

Recursively searches a directory and returns Result<>. Ignores directories with errors and symlinks.