@@ -12,7 +12,7 @@ func (daemon *Daemon) setupLinkedContainers(container *container.Container) ([]s

 }

 // getSize returns real size & virtual size

-func (daemon *Daemon) getSize(container *container.Container) (int64, int64) {

+func (daemon *Daemon) getSize(containerID string) (int64, int64) {

 	// TODO Windows

 	return 0, 0

 }

@@ -4,32 +4,32 @@ package daemon

 import (

 	"github.com/Sirupsen/logrus"

-	"github.com/docker/docker/container"

 )

 // getSize returns the real size & virtual size of the container.

-func (daemon *Daemon) getSize(container *container.Container) (int64, int64) {

+func (daemon *Daemon) getSize(containerID string) (int64, int64) {

 	var (

 		sizeRw, sizeRootfs int64

 		err                error

 	)

-	if err := daemon.Mount(container); err != nil {

-		logrus.Errorf("Failed to compute size of container rootfs %s: %s", container.ID, err)

+	rwlayer, err := daemon.layerStore.GetRWLayer(containerID)

+	if err != nil {

+		logrus.Errorf("Failed to compute size of container rootfs %v: %v", containerID, err)

 		return sizeRw, sizeRootfs

 	}

-	defer daemon.Unmount(container)

+	defer daemon.layerStore.ReleaseRWLayer(rwlayer)

-	sizeRw, err = container.RWLayer.Size()

+	sizeRw, err = rwlayer.Size()

 	if err != nil {

 		logrus.Errorf("Driver %s couldn't return diff size of container %s: %s",

-			daemon.GraphDriverName(), container.ID, err)

+			daemon.GraphDriverName(), containerID, err)

 		// FIXME: GetSize should return an error. Not changing it now in case

 		// there is a side-effect.

 		sizeRw = -1

 	}

-	if parent := container.RWLayer.Parent(); parent != nil {

+	if parent := rwlayer.Parent(); parent != nil {

 		sizeRootfs, err = parent.Size()

 		if err != nil {

 			sizeRootfs = -1

@@ -36,10 +36,10 @@ func (daemon *Daemon) ContainerInspectCurrent(name string, size bool) (*types.Co

 	}

 	container.Lock()

-	defer container.Unlock()

-	base, err := daemon.getInspectData(container, size)

+	base, err := daemon.getInspectData(container)

 	if err != nil {

+		container.Unlock()

 		return nil, err

 	}

@@ -73,6 +73,14 @@ func (daemon *Daemon) ContainerInspectCurrent(name string, size bool) (*types.Co

 	}

 	networkSettings.NetworkSettingsBase.Ports = ports

+	container.Unlock()

+

+	if size {

+		sizeRw, sizeRootFs := daemon.getSize(base.ID)

+		base.SizeRw = &sizeRw

+		base.SizeRootFs = &sizeRootFs

+	}

+

 	return &types.ContainerJSON{

 		ContainerJSONBase: base,

 		Mounts:            mountPoints,

@@ -91,7 +99,7 @@ func (daemon *Daemon) containerInspect120(name string) (*v1p20.ContainerJSON, er

 	container.Lock()

 	defer container.Unlock()

-	base, err := daemon.getInspectData(container, false)

+	base, err := daemon.getInspectData(container)

 	if err != nil {

 		return nil, err

 	}

@@ -114,7 +122,7 @@ func (daemon *Daemon) containerInspect120(name string) (*v1p20.ContainerJSON, er

 	}, nil

 }

-func (daemon *Daemon) getInspectData(container *container.Container, size bool) (*types.ContainerJSONBase, error) {

+func (daemon *Daemon) getInspectData(container *container.Container) (*types.ContainerJSONBase, error) {

 	// make a copy to play with

 	hostConfig := *container.HostConfig

@@ -168,16 +176,6 @@ func (daemon *Daemon) getInspectData(container *container.Container, size bool)

 		HostConfig:   &hostConfig,

 	}

-	var (

-		sizeRw     int64

-		sizeRootFs int64

-	)

-	if size {

-		sizeRw, sizeRootFs = daemon.getSize(container)

-		contJSONBase.SizeRw = &sizeRw

-		contJSONBase.SizeRootFs = &sizeRootFs

-	}

-

 	// Now set any platform-specific fields

 	contJSONBase = setPlatformSpecificContainerFields(container, contJSONBase)

@@ -30,7 +30,7 @@ func (daemon *Daemon) containerInspectPre120(name string) (*v1p19.ContainerJSON,

 	container.Lock()

 	defer container.Unlock()

-	base, err := daemon.getInspectData(container, false)

+	base, err := daemon.getInspectData(container)

 	if err != nil {

 		return nil, err

 	}

@@ -208,19 +208,32 @@ func (daemon *Daemon) reduceContainers(config *types.ContainerListOptions, reduc

 // reducePsContainer is the basic representation for a container as expected by the ps command.

 func (daemon *Daemon) reducePsContainer(container *container.Container, ctx *listContext, reducer containerReducer) (*types.Container, error) {

 	container.Lock()

-	defer container.Unlock()

 	// filter containers to return

 	action := includeContainerInList(container, ctx)

 	switch action {

 	case excludeContainer:

+		container.Unlock()

 		return nil, nil

 	case stopIteration:

+		container.Unlock()

 		return nil, errStopIteration

 	}

 	// transform internal container struct into api structs

-	return reducer(container, ctx)

+	newC, err := reducer(container, ctx)

+	container.Unlock()

+	if err != nil {

+		return nil, err

+	}

+

+	// release lock because size calculation is slow

+	if ctx.Size {

+		sizeRw, sizeRootFs := daemon.getSize(newC.ID)

+		newC.SizeRw = sizeRw

+		newC.SizeRootFs = sizeRootFs

+	}

+	return newC, nil

 }

 // foldFilter generates the container filter based on the user's filtering options.

@@ -642,11 +655,6 @@ func (daemon *Daemon) transformContainer(container *container.Container, ctx *li

 		}

 	}

-	if ctx.Size {

-		sizeRw, sizeRootFs := daemon.getSize(container)

-		newC.SizeRw = sizeRw

-		newC.SizeRootFs = sizeRootFs

-	}

 	newC.Labels = container.Config.Labels

 	newC.Mounts = addMountPoints(container)

@@ -16,7 +16,7 @@ import (

 	"github.com/docker/docker/runconfig"

 	"github.com/docker/docker/volume"

 	"github.com/docker/libnetwork"

-	"github.com/opencontainers/go-digest"

+	digest "github.com/opencontainers/go-digest"

 )

 // ContainersPrune removes unused containers

@@ -34,7 +34,7 @@ func (daemon *Daemon) ContainersPrune(pruneFilters filters.Args) (*types.Contain

 			if !until.IsZero() && c.Created.After(until) {

 				continue

 			}

-			cSize, _ := daemon.getSize(c)

+			cSize, _ := daemon.getSize(c.ID)

 			// TODO: sets RmLink to true?

 			err := daemon.ContainerRm(c.ID, &types.ContainerRmConfig{})

 			if err != nil {