@@ -100,7 +100,7 @@ type DeviceSet struct {

 	dataLoopbackSize      int64

 	metaDataLoopbackSize  int64

 	baseFsSize            uint64

-	userFilesystem        string // FS specified by user using dm.fs

+	filesystem            string

 	mountOptions          string

 	mkfsArgs              []string

 	dataDevice            string // block or loop dev

@@ -149,6 +149,8 @@ type Status struct {

 	Metadata DiskUsage

 	// BaseDeviceSize is base size of container and image

 	BaseDeviceSize uint64

+	// BaseDeviceFS is backing filesystem.

+	BaseDeviceFS string

 	// SectorSize size of the vector.

 	SectorSize uint64

 	// UdevSyncSupported is true if sync is supported.

@@ -584,12 +586,11 @@ func (devices *DeviceSet) createFilesystem(info *devInfo) error {

 	var err error

-	fs := devices.userFilesystem

-	if fs == "" {

-		fs = determineDefaultFS()

+	if devices.filesystem == "" {

+		devices.filesystem = determineDefaultFS()

 	}

-	switch fs {

+	switch devices.filesystem {

 	case "xfs":

 		err = exec.Command("mkfs.xfs", args...).Run()

 	case "ext4":

@@ -602,7 +603,7 @@ func (devices *DeviceSet) createFilesystem(info *devInfo) error {

 		}

 		err = exec.Command("tune2fs", append([]string{"-c", "-1", "-i", "0"}, devname)...).Run()

 	default:

-		err = fmt.Errorf("Unsupported filesystem type %s", fs)

+		err = fmt.Errorf("Unsupported filesystem type %s", devices.filesystem)

 	}

 	if err != nil {

 		return err

@@ -889,6 +890,10 @@ func (devices *DeviceSet) getBaseDeviceSize() uint64 {

 	return info.Size

 }

+func (devices *DeviceSet) getBaseDeviceFS() string {

+	return devices.filesystem

+}

+

 func (devices *DeviceSet) verifyBaseDeviceUUIDFS(baseInfo *devInfo) error {

 	devices.Lock()

 	defer devices.Unlock()

@@ -911,14 +916,15 @@ func (devices *DeviceSet) verifyBaseDeviceUUIDFS(baseInfo *devInfo) error {

 	// If user specified a filesystem using dm.fs option and current

 	// file system of base image is not same, warn user that dm.fs

 	// will be ignored.

-	if devices.userFilesystem != "" {

+	if devices.filesystem != "" {

 		fs, err := ProbeFsType(baseInfo.DevName())

 		if err != nil {

 			return err

 		}

-		if fs != devices.userFilesystem {

-			logrus.Warnf("Base device already exists and has filesystem %s on it. User specified filesystem %s will be ignored.", fs, devices.userFilesystem)

+		if fs != devices.filesystem {

+			logrus.Warnf("Base device already exists and has filesystem %s on it. User specified filesystem %s will be ignored.", fs, devices.filesystem)

+			devices.filesystem = fs

 		}

 	}

 	return nil

@@ -2268,6 +2274,7 @@ func (devices *DeviceSet) Status() *Status {

 	status.DeferredDeleteEnabled = devices.deferredDelete

 	status.DeferredDeletedDeviceCount = devices.nrDeletedDevices

 	status.BaseDeviceSize = devices.getBaseDeviceSize()

+	status.BaseDeviceFS = devices.getBaseDeviceFS()

 	totalSizeInSectors, _, dataUsed, dataTotal, metadataUsed, metadataTotal, err := devices.poolStatus()

 	if err == nil {

@@ -2366,7 +2373,7 @@ func NewDeviceSet(root string, doInit bool, options []string, uidMaps, gidMaps [

 			if val != "ext4" && val != "xfs" {

 				return nil, fmt.Errorf("Unsupported filesystem %s\n", val)

 			}

-			devices.userFilesystem = val

+			devices.filesystem = val

 		case "dm.mkfsarg":

 			devices.mkfsArgs = append(devices.mkfsArgs, val)

 		case "dm.mountopt":

@@ -80,7 +80,7 @@ func (d *Driver) Status() [][2]string {

 		{"Pool Name", s.PoolName},

 		{"Pool Blocksize", fmt.Sprintf("%s", units.HumanSize(float64(s.SectorSize)))},

 		{"Base Device Size", fmt.Sprintf("%s", units.HumanSize(float64(s.BaseDeviceSize)))},

-		{"Backing Filesystem", backingFs},

+		{"Backing Filesystem", s.BaseDeviceFS},

 		{"Data file", s.DataFile},

 		{"Metadata file", s.MetadataFile},

 		{"Data Space Used", fmt.Sprintf("%s", units.HumanSize(float64(s.Data.Used)))},