diff --git a/pkg/s3/controllerserver.go b/pkg/s3/controllerserver.go
index e7cf296..f19709b 100644
--- a/pkg/s3/controllerserver.go
+++ b/pkg/s3/controllerserver.go
@@ -70,36 +70,40 @@ func (cs *controllerServer) CreateVolume(ctx context.Context, req *csi.CreateVol
 	if err != nil {
 		return nil, fmt.Errorf("failed to check if bucket %s exists: %v", volumeID, err)
 	}
+	var b *bucket
 	if exists {
-		var b *bucket
 		b, err = s3.getBucket(volumeID)
-		// TODO 如果 bucket 已经存在了，为什么要去检查它是否有 metadata 和 capacity 呢？
-		// 或者说 metadata 的作用是什么？
+
 		if err != nil {
-			glog.Warningf("failed to get bucket metadata of bucket %s: %v", volumeID, err)
-			// return nil, fmt.Errorf("failed to get bucket metadata of bucket %s: %v", volumeID, err)
-			if err = s3.createPrefix(volumeID, fsPrefix); err != nil {
-				return nil, fmt.Errorf("failed to create prefix %s: %v", fsPrefix, err)
+			glog.Warningf("Bucket %s exists, but failed to get its metadata: %v", volumeID, err)
+			b = &bucket{
+				Name:          volumeID,
+				Mounter:       mounter,
+				CapacityBytes: capacityBytes,
+				FSPath:        "",
+				CreatedByCsi:  false,
 			}
 		} else {
 			// Check if volume capacity requested is bigger than the already existing capacity
 			if capacityBytes > b.CapacityBytes {
 				return nil, status.Error(codes.AlreadyExists, fmt.Sprintf("Volume with the same name: %s but with smaller size already exist", volumeID))
 			}
+			b.Mounter = mounter
 		}
 	} else {
 		if err = s3.createBucket(volumeID); err != nil {
 			return nil, fmt.Errorf("failed to create volume %s: %v", volumeID, err)
 		}
-		if err = s3.createPrefix(volumeID, fsPrefix); err != nil {
-			return nil, fmt.Errorf("failed to create prefix %s: %v", fsPrefix, err)
+		if err = s3.createPrefix(volumeID, defaultFsPrefix); err != nil {
+			return nil, fmt.Errorf("failed to create prefix %s: %v", defaultFsPrefix, err)
+		}
+		b = &bucket{
+			Name:          volumeID,
+			Mounter:       mounter,
+			CapacityBytes: capacityBytes,
+			FSPath:        defaultFsPrefix,
+			CreatedByCsi:  !exists,
 		}
-	}
-	b := &bucket{
-		Name:          volumeID,
-		Mounter:       mounter,
-		CapacityBytes: capacityBytes,
-		FSPath:        fsPrefix,
 	}
 	if err := s3.setBucket(b); err != nil {
 		return nil, fmt.Errorf("Error setting bucket metadata: %v", err)
diff --git a/pkg/s3/s3-client.go b/pkg/s3/s3-client.go
index 646d142..7d25895 100644
--- a/pkg/s3/s3-client.go
+++ b/pkg/s3/s3-client.go
@@ -14,8 +14,8 @@ import (
 )
 
 const (
-	metadataName = ".metadata.json"
-	fsPrefix     = "csi-fs"
+	metadataName    = ".metadata.json"
+	defaultFsPrefix = "csi-fs"
 )
 
 type s3Client struct {
@@ -29,6 +29,7 @@ type bucket struct {
 	Mounter       string
 	FSPath        string
 	CapacityBytes int64
+	CreatedByCsi  bool
 }
 
 func newS3Client(cfg *Config) (*s3Client, error) {
@@ -133,7 +134,7 @@ func (client *s3Client) emptyBucket(bucketName string) error {
 	}
 
 	// ensure our prefix is also removed
-	return client.minio.RemoveObject(client.ctx, bucketName, fsPrefix, minio.RemoveObjectOptions{})
+	return client.minio.RemoveObject(client.ctx, bucketName, defaultFsPrefix, minio.RemoveObjectOptions{})
 }
 
 func (client *s3Client) setBucket(bucket *bucket) error {