Add more volume types in e2e and fix part of them.

- Add dir-link/dir-bindmounted/dir-link-bindmounted/blockfs volume types for e2e
tests.
- Return error if we cannot resolve volume path.
- Add GetFSGroup/GetMountRefs methods for mount.Interface.
- Fix fsGroup related e2e tests partially.

pkg/kubelet/cm/container_manager_linux_test.go

@@ -19,6 +19,7 @@ limitations under the License.
 package cm
 
 import (
+	"errors"
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -107,6 +108,14 @@ func (mi *fakeMountInterface) SafeMakeDir(_, _ string, _ os.FileMode) error {
 	return nil
 }
 
+func (mi *fakeMountInterface) GetMountRefs(pathname string) ([]string, error) {
+	return nil, errors.New("not implemented")
+}
+
+func (mi *fakeMountInterface) GetFSGroup(pathname string) (int64, error) {
+	return -1, errors.New("not implemented")
+}
+
 func fakeContainerMgrMountInt() mount.Interface {
 	return &fakeMountInterface{
 		[]mount.MountPoint{