@@ -21,7 +21,7 @@ import (

 	"github.com/opencontainers/runc/libcontainer/label"

 )

-type ZfsOptions struct {

+type zfsOptions struct {

 	fsName    string

 	mountPath string

 }

@@ -30,12 +30,17 @@ func init() {

 	graphdriver.Register("zfs", Init)

 }

+// Logger returns a zfs logger implmentation.

 type Logger struct{}

+// Log wraps log message from ZFS driver with a prefix '[zfs]'.

 func (*Logger) Log(cmd []string) {

 	logrus.Debugf("[zfs] %s", strings.Join(cmd, " "))

 }

+// Init returns a new ZFS driver.

+// It takes base mount path and a array of options which are represented as key value pairs.

+// Each option is in the for key=value. 'zfs.fsname' is expected to be a valid key in the options.

 func Init(base string, opt []string) (graphdriver.Driver, error) {

 	var err error

@@ -101,8 +106,8 @@ func Init(base string, opt []string) (graphdriver.Driver, error) {

 	return graphdriver.NaiveDiffDriver(d), nil

 }

-func parseOptions(opt []string) (ZfsOptions, error) {

-	var options ZfsOptions

+func parseOptions(opt []string) (zfsOptions, error) {

+	var options zfsOptions

 	options.fsName = ""

 	for _, option := range opt {

 		key, val, err := parsers.ParseKeyValueOpt(option)

@@ -145,9 +150,10 @@ func lookupZfsDataset(rootdir string) (string, error) {

 	return "", fmt.Errorf("Failed to find zfs dataset mounted on '%s' in /proc/mounts", rootdir)

 }

+// Driver holds information about the driver, such as zfs dataset, options and cache.

 type Driver struct {

 	dataset          *zfs.Dataset

-	options          ZfsOptions

+	options          zfsOptions

 	sync.Mutex       // protects filesystem cache against concurrent access

 	filesystemsCache map[string]bool

 }

@@ -156,10 +162,15 @@ func (d *Driver) String() string {

 	return "zfs"

 }

+// Cleanup is used to implement graphdriver.ProtoDriver. There is no cleanup required for this driver.

 func (d *Driver) Cleanup() error {

 	return nil

 }

+// Status returns information about the ZFS filesystem. It returns a two dimensional array of information

+// such as pool name, dataset name, disk usage, parent quota and compression used.

+// Currently it return 'Zpool', 'Zpool Health', 'Parent Dataset', 'Space Used By Parent',

+// 'Space Available', 'Parent Quota' and 'Compression'.

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

 	parts := strings.Split(d.dataset.Name, "/")

 	pool, err := zfs.GetZpool(parts[0])

@@ -189,6 +200,7 @@ func (d *Driver) Status() [][2]string {

 	}

 }

+// GetMetadata is used for implementing the graphdriver.ProtoDriver interface. ZFS does not currently have any meta data.

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

 	return nil, nil

 }

@@ -215,14 +227,17 @@ func (d *Driver) cloneFilesystem(name, parentName string) error {

 	return snapshot.Destroy(zfs.DestroyDeferDeletion)

 }

+// ZfsPath returns the filesystem path for the id provided.

 func (d *Driver) ZfsPath(id string) string {

 	return d.options.fsName + "/" + id

 }

+// MountPath returns the mounted filesystem path for the id provided.

 func (d *Driver) MountPath(id string) string {

 	return path.Join(d.options.mountPath, "graph", getMountpoint(id))

 }

+// Create prepares the dataset and filesystem for the ZFS driver for the given id under the parent.

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

 	err := d.create(id, parent)

 	if err == nil {

@@ -261,6 +276,7 @@ func (d *Driver) create(id, parent string) error {

 	return d.cloneFilesystem(name, d.ZfsPath(parent))

 }

+// Remove deletes the dataset, filesystem and the cache for the given id.

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

 	name := d.ZfsPath(id)

 	dataset := zfs.Dataset{Name: name}

@@ -273,6 +289,7 @@ func (d *Driver) Remove(id string) error {

 	return err

 }

+// Get returns the mountpoint for the given id after creating the target directories if necessary.

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

 	mountpoint := d.MountPath(id)

 	filesystem := d.ZfsPath(id)

@@ -292,6 +309,7 @@ func (d *Driver) Get(id, mountLabel string) (string, error) {

 	return mountpoint, nil

 }

+// Put removes the existing mountpoint for the given id if it exists.

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

 	mountpoint := d.MountPath(id)

 	logrus.Debugf(`[zfs] unmount("%s")`, mountpoint)

@@ -302,6 +320,7 @@ func (d *Driver) Put(id string) error {

 	return nil

 }

+// Exists checks to see if the cache entry exists for the given id.

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

 	return d.filesystemsCache[d.ZfsPath(id)] == true

 }

@@ -26,6 +26,7 @@ packages=(

 	daemon/execdriver/windows

 	daemon/graphdriver/aufs

 	daemon/graphdriver/devmapper

+	daemon/graphdriver/zfs

 	daemon/logger

 	daemon/logger/fluentd

 	daemon/logger/gelf