List all local filesystems mounted on this system.

def EnumerateFilesystemsFromClient(args):
  """List all local filesystems mounted on this system."""
  del args  # Unused.
  for fs_struct in client_utils_osx.GetFileSystems():
    yield rdf_client_fs.Filesystem(
        device=fs_struct.f_mntfromname,
        mount_point=fs_struct.f_mntonname,
        type=fs_struct.f_fstypename)

  drive_re = re.compile("r?disk[0-9].*")
  for drive in os.listdir("/dev"):
    if not drive_re.match(drive):
      continue

    path = os.path.join("/dev", drive)
    try:
      img_inf = pytsk3.Img_Info(path)
      # This is a volume or a partition - we send back a TSK device.
      yield rdf_client_fs.Filesystem(device=path)

      vol_inf = pytsk3.Volume_Info(img_inf)

      for volume in vol_inf:
        if volume.flags == pytsk3.TSK_VS_PART_FLAG_ALLOC:
          offset = volume.start * vol_inf.info.block_size
          yield rdf_client_fs.Filesystem(
              device="{path}:{offset}".format(path=path, offset=offset),
              type="partition")

    except (IOError, RuntimeError):
      continue