// Detaches the block disk from the kubelet's host machine.
	DetachBlockFCDisk(disk fcDiskUnmapper, mntPath, devicePath string) error
}

// utility to mount a disk based filesystem
func diskSetUp(manager diskManager, b fcDiskMounter, volPath string, mounter mount.Interface, fsGroup *int64, fsGroupChangePolicy *v1.PodFSGroupChangePolicy) error {
	globalPDPath := manager.MakeGlobalPDName(*b.fcDisk)

// volPath: pod volume dir path like, /var/lib/kubelet/pods/{podUID}/volumes/kubernetes.io~iscsi/{volumeName}
func diskSetUp(manager diskManager, b iscsiDiskMounter, volPath string, mounter mount.Interface, fsGroup *int64, fsGroupChangePolicy *v1.PodFSGroupChangePolicy) error {
	notMnt, err := mounter.IsLikelyNotMountPoint(volPath)

	return b.SetUpAt(b.GetPath(), mounterArgs)
}

func (b *fcDiskMounter) SetUpAt(dir string, mounterArgs volume.MounterArgs) error {
	// diskSetUp checks mountpoints and prevent repeated calls
	err := diskSetUp(b.manager, *b, dir, b.mounter, mounterArgs.FsGroup, mounterArgs.FSGroupChangePolicy)
	if err != nil {
		klog.Errorf("fc: failed to setup")
	}

	return b.SetUpAt(b.GetPath(), mounterArgs)
}

func (b *iscsiDiskMounter) SetUpAt(dir string, mounterArgs volume.MounterArgs) error {
	// diskSetUp checks mountpoints and prevent repeated calls
	err := diskSetUp(b.manager, *b, dir, b.mounter, mounterArgs.FsGroup, mounterArgs.FSGroupChangePolicy)
	if err != nil {
		klog.Errorf("iscsi: failed to setup")
	}