Make a filesystem using the appropriate module

    .. versionadded:: Beryllium

def _mkfs(root, fs_format, fs_opts=None):
    '''
    Make a filesystem using the appropriate module

    .. versionadded:: Beryllium
    '''
    if fs_opts is None:
        fs_opts = {}

    if fs_format in ('ext2', 'ext3', 'ext4'):
        __salt__['extfs.mkfs'](root, fs_format, **fs_opts)
    elif fs_format in ('btrfs',):
        __salt__['btrfs.mkfs'](root, **fs_opts)
    elif fs_format in ('xfs',):
        __salt__['xfs.mkfs'](root, **fs_opts)