@@ -12,6 +12,8 @@ import (

 	"reflect"

 	"sync"

+	"github.com/pkg/errors"

+

 	"github.com/Sirupsen/logrus"

 	"github.com/docker/docker/pkg/idtools"

 	"github.com/docker/docker/pkg/mount"

@@ -93,7 +95,7 @@ func New(scope string, rootUID, rootGID int) (*Root, error) {

 		if b, err := ioutil.ReadFile(optsFilePath); err == nil {

 			opts := optsConfig{}

 			if err := json.Unmarshal(b, &opts); err != nil {

-				return nil, err

+				return nil, errors.Wrapf(err, "error while unmarshaling volume options for volume: %s", name)

 			}

 			// Make sure this isn't an empty optsConfig.

 			// This could be empty due to buggy behavior in older versions of Docker.

@@ -168,7 +170,7 @@ func (r *Root) Create(name string, opts map[string]string) (volume.Volume, error

 		if os.IsExist(err) {

 			return nil, fmt.Errorf("volume already exists under %s", filepath.Dir(path))

 		}

-		return nil, err

+		return nil, errors.Wrapf(err, "error while creating volume path '%s'", path)

 	}

 	var err error

@@ -194,7 +196,7 @@ func (r *Root) Create(name string, opts map[string]string) (volume.Volume, error

 			return nil, err

 		}

 		if err = ioutil.WriteFile(filepath.Join(filepath.Dir(path), "opts.json"), b, 600); err != nil {

-			return nil, err

+			return nil, errors.Wrap(err, "error while persisting volume options")

 		}

 	}

@@ -240,7 +242,7 @@ func removePath(path string) error {

 		if os.IsNotExist(err) {

 			return nil

 		}

-		return err

+		return errors.Wrapf(err, "error removing volume path '%s'", path)

 	}

 	return nil

 }

@@ -327,7 +329,7 @@ func (v *localVolume) Unmount(id string) error {

 		if v.active.count == 0 {

 			if err := mount.Unmount(v.path); err != nil {

 				v.active.count++

-				return err

+				return errors.Wrapf(err, "error while unmounting volume path '%s'", v.path)

 			}

 			v.active.mounted = false

 		}

@@ -10,6 +10,8 @@ import (

 	"path/filepath"

 	"strings"

+	"src/github.com/pkg/errors"

+

 	"github.com/docker/docker/pkg/mount"

 )

@@ -29,6 +31,10 @@ type optsConfig struct {

 	MountDevice string

 }

+func (o *optsConfig) String() string {

+	return fmt.Sprintf("type='%s' device='%s' o='%s'", o.MountType, o.MountDevice, o.MountOpts)

+}

+

 // scopedPath verifies that the path where the volume is located

 // is under Docker's root and the valid local paths.

 func (r *Root) scopedPath(realPath string) bool {

@@ -65,5 +71,6 @@ func (v *localVolume) mount() error {

 	if v.opts.MountDevice == "" {

 		return fmt.Errorf("missing device in volume options")

 	}

-	return mount.Mount(v.opts.MountDevice, v.path, v.opts.MountType, v.opts.MountOpts)

+	err := mount.Mount(v.opts.MountDevice, v.path, v.opts.MountType, v.opts.MountOpts)

+	return errors.Wrapf(err, "error while mounting volume with options: %s", v.opts)

 }

@@ -8,6 +8,8 @@ import (

 	"sync"

 	"time"

+	"github.com/pkg/errors"

+

 	"github.com/Sirupsen/logrus"

 	"github.com/boltdb/bolt"

 	"github.com/docker/docker/pkg/locker"

@@ -70,13 +72,13 @@ func New(rootPath string) (*VolumeStore, error) {

 		var err error

 		vs.db, err = bolt.Open(dbPath, 0600, &bolt.Options{Timeout: 1 * time.Second})

 		if err != nil {

-			return nil, err

+			return nil, errors.Wrap(err, "error while opening volume store metadata database")

 		}

 		// initialize volumes bucket

 		if err := vs.db.Update(func(tx *bolt.Tx) error {

 			if _, err := tx.CreateBucketIfNotExists([]byte(volumeBucketName)); err != nil {

-				return err

+				return errors.Wrap(err, "error while setting up volume store metadata database")

 			}

 			return nil

@@ -299,7 +301,7 @@ func (s *VolumeStore) create(name, driverName string, opts, labels map[string]st

 			err := b.Put([]byte(name), volData)

 			return err

 		}); err != nil {

-			return nil, err

+			return nil, errors.Wrap(err, "error while persisting volume metadata")

 		}

 	}

@@ -11,6 +11,7 @@ import (

 	"github.com/docker/docker/pkg/idtools"

 	"github.com/docker/docker/pkg/stringid"

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

+	"github.com/pkg/errors"

 )

 // DefaultDriverName is the driver name used for the driver

@@ -114,7 +115,8 @@ func (m *MountPoint) Setup(mountLabel string, rootUID, rootGID int) (string, err

 		if m.ID == "" {

 			m.ID = stringid.GenerateNonCryptoID()

 		}

-		return m.Volume.Mount(m.ID)

+		path, err := m.Volume.Mount(m.ID)

+		return path, errors.Wrapf(err, "error while mounting volume '%s'", m.Source)

 	}

 	if len(m.Source) == 0 {

 		return "", fmt.Errorf("Unable to setup mount point, neither source nor volume defined")

@@ -126,14 +128,14 @@ func (m *MountPoint) Setup(mountLabel string, rootUID, rootGID int) (string, err

 		if err := idtools.MkdirAllNewAs(m.Source, 0755, rootUID, rootGID); err != nil {

 			if perr, ok := err.(*os.PathError); ok {

 				if perr.Err != syscall.ENOTDIR {

-					return "", err

+					return "", errors.Wrapf(err, "error while creating mount source path '%s'", m.Source)

 				}

 			}

 		}

 	}

 	if label.RelabelNeeded(m.Mode) {

 		if err := label.Relabel(m.Source, mountLabel, label.IsShared(m.Mode)); err != nil {

-			return "", err

+			return "", errors.Wrapf(err, "error setting label on mount source '%s'", m.Source)

 		}

 	}

 	return m.Source, nil