func (self *dockerContainerHandler) getFsStats(stats *info.ContainerStats) error {
	switch self.storageDriver {
	case aufsStorageDriver, overlayStorageDriver, zfsStorageDriver:
	default:
		return nil
	}

	// As of now we assume that all the storage dirs are on the same device.
	// The first storage dir will be that of the image layers.
	deviceInfo, err := self.fsInfo.GetDirFsDevice(self.storageDirs[0])
	if err != nil {
		return err
	}

	mi, err := self.machineInfoFactory.GetMachineInfo()
	if err != nil {
		return err
	}
	var limit uint64 = 0
	// Docker does not impose any filesystem limits for containers. So use capacity as limit.
	for _, fs := range mi.Filesystems {
		if fs.Device == deviceInfo.Device {
			limit = fs.Capacity
			break
		}
	}

	fsStat := info.FsStats{Device: deviceInfo.Device, Limit: limit}

	fsStat.Usage = self.fsHandler.usage()
	stats.Filesystem = append(stats.Filesystem, fsStat)

	return nil
}

func (handler *rktContainerHandler) getFsStats(stats *info.ContainerStats) error {
	if handler.ignoreMetrics.Has(container.DiskUsageMetrics) {
		return nil
	}

	deviceInfo, err := handler.fsInfo.GetDirFsDevice(handler.rootfsStorageDir)
	if err != nil {
		return err
	}

	mi, err := handler.machineInfoFactory.GetMachineInfo()
	if err != nil {
		return err
	}
	var limit uint64 = 0

	// Use capacity as limit.
	for _, fs := range mi.Filesystems {
		if fs.Device == deviceInfo.Device {
			limit = fs.Capacity
			break
		}
	}

	fsStat := info.FsStats{Device: deviceInfo.Device, Limit: limit}

	usage := handler.fsHandler.Usage()
	fsStat.BaseUsage = usage.BaseUsageBytes
	fsStat.Usage = usage.TotalUsageBytes
	fsStat.Inodes = usage.InodeUsage

	stats.Filesystem = append(stats.Filesystem, fsStat)

	return nil
}

func (self *dockerContainerHandler) getFsStats(stats *info.ContainerStats) error {
	if self.ignoreMetrics.Has(container.DiskUsageMetrics) {
		return nil
	}
	var device string
	switch self.storageDriver {
	case devicemapperStorageDriver:
		// Device has to be the pool name to correlate with the device name as
		// set in the machine info filesystems.
		device = self.poolName
	case aufsStorageDriver, overlayStorageDriver, zfsStorageDriver:
		deviceInfo, err := self.fsInfo.GetDirFsDevice(self.rootfsStorageDir)
		if err != nil {
			return fmt.Errorf("unable to determine device info for dir: %v: %v", self.rootfsStorageDir, err)
		}
		device = deviceInfo.Device
	default:
		return nil
	}

	mi, err := self.machineInfoFactory.GetMachineInfo()
	if err != nil {
		return err
	}

	var (
		limit  uint64
		fsType string
	)

	// Docker does not impose any filesystem limits for containers. So use capacity as limit.
	for _, fs := range mi.Filesystems {
		if fs.Device == device {
			limit = fs.Capacity
			fsType = fs.Type
			break
		}
	}

	fsStat := info.FsStats{Device: device, Type: fsType, Limit: limit}
	usage := self.fsHandler.Usage()
	fsStat.BaseUsage = usage.BaseUsageBytes
	fsStat.Usage = usage.TotalUsageBytes
	fsStat.Inodes = usage.InodeUsage

	stats.Filesystem = append(stats.Filesystem, fsStat)

	return nil
}

// cmeFactory generates a complete ContainerMetricElement with fuzzed data.
// CMEs created by cmeFactory contain partially fuzzed stats, aside from hardcoded values for Memory usage.
// The timestamp of the CME is rouded to the current minute and offset by a random number of hours.
func cmeFactory() *cache.ContainerMetricElement {
	f := fuzz.New().NilChance(0).NumElements(1, 1)
	containerSpec := source_api.ContainerSpec{
		ContainerSpec: cadvisor.ContainerSpec{
			CreationTime:  time.Now(),
			HasCpu:        true,
			HasMemory:     true,
			HasNetwork:    true,
			HasFilesystem: true,
			HasDiskIo:     true,
		},
	}
	containerSpec.Cpu.Limit = 1024
	containerSpec.Memory.Limit = 10000000

	// Create a fuzzed ContainerStats struct
	var containerStats source_api.ContainerStats
	f.Fuzz(&containerStats)

	// Standardize timestamp to the current minute plus a random number of hours ([1, 10])
	now_time := time.Now().Round(time.Minute)
	new_time := now_time
	for new_time == now_time {
		new_time = now_time.Add(time.Duration(rand.Intn(10)) * 5 * time.Minute)
	}
	containerStats.Timestamp = new_time
	containerSpec.CreationTime = new_time.Add(-time.Hour)

	// Standardize memory usage and limit to test aggregation
	containerStats.Memory.Usage = uint64(5000)
	containerStats.Memory.WorkingSet = uint64(602)

	// Standardize the device name, usage and limit
	new_fs := cadvisor.FsStats{}
	f.Fuzz(&new_fs)
	new_fs.Device = "/dev/device1"
	new_fs.Usage = 50000
	new_fs.Limit = 100000
	containerStats.Filesystem = []cadvisor.FsStats{new_fs}

	return &cache.ContainerMetricElement{
		Spec:  &containerSpec,
		Stats: &containerStats,
	}
}

func (self *dockerContainerHandler) getFsStats(stats *info.ContainerStats) error {
	// No support for non-aufs storage drivers.
	if !self.usesAufsDriver {
		return nil
	}

	// As of now we assume that all the storage dirs are on the same device.
	// The first storage dir will be that of the image layers.
	deviceInfo, err := self.fsInfo.GetDirFsDevice(self.storageDirs[0])
	if err != nil {
		return err
	}

	mi, err := self.machineInfoFactory.GetMachineInfo()
	if err != nil {
		return err
	}
	var limit uint64 = 0
	// Docker does not impose any filesystem limits for containers. So use capacity as limit.
	for _, fs := range mi.Filesystems {
		if fs.Device == deviceInfo.Device {
			limit = fs.Capacity
			break
		}
	}

	fsStat := info.FsStats{Device: deviceInfo.Device, Limit: limit}

	var usage uint64 = 0
	for _, dir := range self.storageDirs {
		// TODO(Vishh): Add support for external mounts.
		dirUsage, err := self.fsInfo.GetDirUsage(dir)
		if err != nil {
			return err
		}
		usage += dirUsage
	}
	fsStat.Usage = usage
	stats.Filesystem = append(stats.Filesystem, fsStat)

	return nil
}

// cmeFactory generates a complete ContainerMetricElement with fuzzed data.
func cmeFactory() *cache.ContainerMetricElement {
	f := fuzz.New().NilChance(0).NumElements(1, 1)
	containerSpec := cadvisor.ContainerSpec{
		CreationTime:  time.Now(),
		HasCpu:        true,
		HasMemory:     true,
		HasNetwork:    true,
		HasFilesystem: true,
		HasDiskIo:     true,
	}
	var containerStats cadvisor.ContainerStats
	f.Fuzz(&containerStats)
	containerStats.Timestamp = time.Now()

	new_fs := cadvisor.FsStats{}
	f.Fuzz(&new_fs)
	new_fs.Device = "/dev/device1"
	containerStats.Filesystem = []cadvisor.FsStats{new_fs}

	return &cache.ContainerMetricElement{
		Spec:  &containerSpec,
		Stats: &containerStats,
	}
}