message: nydus-test: some works to adapt to rafs v6
diff: @@ -196,8 +196,8 @@ def test_prefetch_with_cache(
  nc = NydusAPIClient(rafs.get_apisock())
  workload_gen = WorkloadGen(nydus_anchor.mount_point, nydus_scratch_image.rootfs())
  - m = nc.get_blobcache_metrics()
  time.sleep(0.3)
  + m = nc.get_blobcache_metrics()
  assert m["prefetch_data_amount"] != 0
  workload_gen.setup_workload_generator()
  @@ -549,7 +549,7 @@ def test_pseudo_fs(nydus_anchor, nydus_image, rafs_conf: RafsConf):
  nc.umount_rafs("/pseudo3")
  -def test_shared_blobcache(nydus_anchor, nydus_image, rafs_conf: RafsConf):
  +def test_shared_blobcache(nydus_anchor: NydusAnchor, nydus_image, rafs_conf: RafsConf):
  """
  description:
  Start more than one nydusd, let them share the same blobcache.
  @@ -588,7 +588,10 @@ def test_shared_blobcache(nydus_anchor, nydus_image, rafs_conf: RafsConf):
  for case in cases:
  case[1].finish_torture_read()
  # Ensure that blob & bitmap files are included in blobcache dir.
  + if int(nydus_anchor.fs_version) == 5:
  assert len(os.listdir(nydus_anchor.blobcache_dir)) == 2
  + elif int(nydus_anchor.fs_version) == 6:
  + assert len(os.listdir(nydus_anchor.blobcache_dir)) == 3
  for case in cases:
  case[0].umount()
  