diff --git a/libcontainer/cgroups/fs/freezer.go b/libcontainer/cgroups/fs/freezer.go index 519bd5136..4baa2798a 100644 --- a/libcontainer/cgroups/fs/freezer.go +++ b/libcontainer/cgroups/fs/freezer.go @@ -129,7 +129,25 @@ func (s *FreezerGroup) GetState(path string) (configs.FreezerState, error) { case "THAWED": return configs.Thawed, nil case "FROZEN": - return configs.Frozen, nil + // Find out whether the cgroup is frozen directly, + // or indirectly via an ancestor. + self, err := cgroups.ReadFile(path, "freezer.self_freezing") + if err != nil { + // If the kernel is too old, then we just treat + // it as being frozen. + if errors.Is(err, os.ErrNotExist) || errors.Is(err, unix.ENODEV) { + err = nil + } + return configs.Frozen, err + } + switch self { + case "0\n": + return configs.Thawed, nil + case "1\n": + return configs.Frozen, nil + default: + return configs.Undefined, fmt.Errorf(`unknown "freezer.self_freezing" state: %q`, self) + } case "FREEZING": // Make sure we get a stable freezer state, so retry if the cgroup // is still undergoing freezing. This should be a temporary delay.