@@ -24,6 +24,8 @@ func init() {

 	graphdriver.Register("btrfs", Init)

 }

+// Init returns a new BTRFS driver.

+// An error is returned if BTRFS is not supported.

 func Init(home string, options []string) (graphdriver.Driver, error) {

 	rootdir := path.Dir(home)

@@ -51,29 +53,37 @@ func Init(home string, options []string) (graphdriver.Driver, error) {

 	return graphdriver.NaiveDiffDriver(driver), nil

 }

+// Driver contains information about the filesystem mounted.

 type Driver struct {

+	//root of the file system

 	home string

 }

+// String prints the name of the driver (btrfs).

 func (d *Driver) String() string {

 	return "btrfs"

 }

+// Status returns current driver information in a two dimensional string array.

+// Output contains "Build Version" and "Library Version" of the btrfs libraries used.

+// Version information can be used to check compatibility with your kernel.

 func (d *Driver) Status() [][2]string {

 	status := [][2]string{}

-	if bv := BtrfsBuildVersion(); bv != "-" {

+	if bv := btrfsBuildVersion(); bv != "-" {

 		status = append(status, [2]string{"Build Version", bv})

 	}

-	if lv := BtrfsLibVersion(); lv != -1 {

+	if lv := btrfsLibVersion(); lv != -1 {

 		status = append(status, [2]string{"Library Version", fmt.Sprintf("%d", lv)})

 	}

 	return status

 }

+// GetMetadata returns empty metadata for this driver.

 func (d *Driver) GetMetadata(id string) (map[string]string, error) {

 	return nil, nil

 }

+// Cleanup unmounts the home directory.

 func (d *Driver) Cleanup() error {

 	return mount.Unmount(d.home)

 }

@@ -174,10 +184,11 @@ func (d *Driver) subvolumesDir() string {

 	return path.Join(d.home, "subvolumes")

 }

-func (d *Driver) subvolumesDirId(id string) string {

+func (d *Driver) subvolumesDirID(id string) string {

 	return path.Join(d.subvolumesDir(), id)

 }

+// Create the filesystem with given id.

 func (d *Driver) Create(id string, parent string) error {

 	subvolumes := path.Join(d.home, "subvolumes")

 	if err := os.MkdirAll(subvolumes, 0700); err != nil {

@@ -199,8 +210,9 @@ func (d *Driver) Create(id string, parent string) error {

 	return nil

 }

+// Remove the filesystem with given id.

 func (d *Driver) Remove(id string) error {

-	dir := d.subvolumesDirId(id)

+	dir := d.subvolumesDirID(id)

 	if _, err := os.Stat(dir); err != nil {

 		return err

 	}

@@ -210,8 +222,9 @@ func (d *Driver) Remove(id string) error {

 	return os.RemoveAll(dir)

 }

+// Get the requested filesystem id.

 func (d *Driver) Get(id, mountLabel string) (string, error) {

-	dir := d.subvolumesDirId(id)

+	dir := d.subvolumesDirID(id)

 	st, err := os.Stat(dir)

 	if err != nil {

 		return "", err

@@ -224,14 +237,16 @@ func (d *Driver) Get(id, mountLabel string) (string, error) {

 	return dir, nil

 }

+// Put is not implemented for BTRFS as there is no cleanup required for the id.

 func (d *Driver) Put(id string) error {

 	// Get() creates no runtime resources (like e.g. mounts)

 	// so this doesn't need to do anything.

 	return nil

 }

+// Exists checks if the id exists in the filesystem.

 func (d *Driver) Exists(id string) bool {

-	dir := d.subvolumesDirId(id)

+	dir := d.subvolumesDirID(id)

 	_, err := os.Stat(dir)

 	return err == nil

 }

@@ -17,10 +17,10 @@ package btrfs

 */

 import "C"

-func BtrfsBuildVersion() string {

+func btrfsBuildVersion() string {

 	return string(C.BTRFS_BUILD_VERSION)

 }

-func BtrfsLibVersion() int {

+func btrfsLibVersion() int {

 	return int(C.BTRFS_LIB_VERSION)

 }

@@ -5,10 +5,10 @@ package btrfs

 // TODO(vbatts) remove this work-around once supported linux distros are on

 // btrfs utililties of >= 3.16.1

-func BtrfsBuildVersion() string {

+func btrfsBuildVersion() string {

 	return "-"

 }

-func BtrfsLibVersion() int {

+func btrfsLibVersion() int {

 	return -1

 }