@@ -55,6 +55,7 @@ import (

 	"io/ioutil"

 	"path"

 	"path/filepath"

+	"sync"

 	"unsafe"

 	"github.com/containerd/containerd/sys"

@@ -63,6 +64,33 @@ import (

 	"golang.org/x/sys/unix"

 )

+type pquotaState struct {

+	sync.Mutex

+	nextProjectID uint32

+}

+

+var pquotaStateInst *pquotaState

+var pquotaStateOnce sync.Once

+

+// getPquotaState - get global pquota state tracker instance

+func getPquotaState() *pquotaState {

+	pquotaStateOnce.Do(func() {

+		pquotaStateInst = &pquotaState{

+			nextProjectID: 1,

+		}

+	})

+	return pquotaStateInst

+}

+

+// registerBasePath - register a new base path and update nextProjectID

+func (state *pquotaState) updateMinProjID(minProjectID uint32) {

+	state.Lock()

+	defer state.Unlock()

+	if state.nextProjectID <= minProjectID {

+		state.nextProjectID = minProjectID + 1

+	}

+}

+

 // NewControl - initialize project quota support.

 // Test to make sure that quota can be set on a test dir and find

 // the first project id to be used for the next container create.

@@ -115,11 +143,11 @@ func NewControl(basePath string) (*Control, error) {

 	//

 	// Get project id of parent dir as minimal id to be used by driver

 	//

-	minProjectID, err := getProjectID(basePath)

+	baseProjectID, err := getProjectID(basePath)

 	if err != nil {

 		return nil, err

 	}

-	minProjectID++

+	minProjectID := baseProjectID + 1

 	//

 	// Test if filesystem supports project quotas by trying to set

@@ -134,19 +162,24 @@ func NewControl(basePath string) (*Control, error) {

 	q := Control{

 		backingFsBlockDev: backingFsBlockDev,

-		nextProjectID:     minProjectID + 1,

 		quotas:            make(map[string]uint32),

 	}

 	//

+	// update minimum project ID

+	//

+	state := getPquotaState()

+	state.updateMinProjID(minProjectID)

+

+	//

 	// get first project id to be used for next container

 	//

-	err = q.findNextProjectID(basePath)

+	err = q.findNextProjectID(basePath, baseProjectID)

 	if err != nil {

 		return nil, err

 	}

-	logrus.Debugf("NewControl(%s): nextProjectID = %d", basePath, q.nextProjectID)

+	logrus.Debugf("NewControl(%s): nextProjectID = %d", basePath, state.nextProjectID)

 	return &q, nil

 }

@@ -157,19 +190,24 @@ func (q *Control) SetQuota(targetPath string, quota Quota) error {

 	projectID, ok := q.quotas[targetPath]

 	q.RUnlock()

 	if !ok {

-		q.Lock()

-		projectID = q.nextProjectID

+		state := getPquotaState()

+		state.Lock()

+		projectID = state.nextProjectID

 		//

 		// assign project id to new container directory

 		//

 		err := setProjectID(targetPath, projectID)

 		if err != nil {

-			q.Unlock()

+			state.Unlock()

 			return err

 		}

+

+		state.nextProjectID++

+		state.Unlock()

+

+		q.Lock()

 		q.quotas[targetPath] = projectID

-		q.nextProjectID++

 		q.Unlock()

 	}

@@ -279,9 +317,25 @@ func setProjectID(targetPath string, projectID uint32) error {

 // findNextProjectID - find the next project id to be used for containers

 // by scanning driver home directory to find used project ids

-func (q *Control) findNextProjectID(home string) error {

-	q.Lock()

-	defer q.Unlock()

+func (q *Control) findNextProjectID(home string, baseID uint32) error {

+	state := getPquotaState()

+	state.Lock()

+	defer state.Unlock()

+

+	checkProjID := func(path string) (uint32, error) {

+		projid, err := getProjectID(path)

+		if err != nil {

+			return projid, err

+		}

+		if projid > 0 {

+			q.quotas[path] = projid

+		}

+		if state.nextProjectID <= projid {

+			state.nextProjectID = projid + 1

+		}

+		return projid, nil

+	}

+

 	files, err := ioutil.ReadDir(home)

 	if err != nil {

 		return errors.Errorf("read directory failed: %s", home)

@@ -291,15 +345,26 @@ func (q *Control) findNextProjectID(home string) error {

 			continue

 		}

 		path := filepath.Join(home, file.Name())

-		projid, err := getProjectID(path)

+		projid, err := checkProjID(path)

 		if err != nil {

 			return err

 		}

-		if projid > 0 {

-			q.quotas[path] = projid

+		if projid > 0 && projid != baseID {

+			continue

+		}

+		subfiles, err := ioutil.ReadDir(path)

+		if err != nil {

+			return errors.Errorf("read directory failed: %s", path)

 		}

-		if q.nextProjectID <= projid {

-			q.nextProjectID = projid + 1

+		for _, subfile := range subfiles {

+			if !subfile.IsDir() {

+				continue

+			}

+			subpath := filepath.Join(path, subfile.Name())

+			_, err := checkProjID(subpath)

+			if err != nil {

+				return err

+			}

 		}

 	}

@@ -14,6 +14,5 @@ type Quota struct {

 type Control struct {

 	backingFsBlockDev string

 	sync.RWMutex      // protect nextProjectID and quotas map

-	nextProjectID     uint32

 	quotas            map[string]uint32

 }