diff --git a/libcontainer/cgroups/fs/freezer.go b/libcontainer/cgroups/fs/freezer.go index 1193ec27110..5aefdf511fe 100644 --- a/libcontainer/cgroups/fs/freezer.go +++ b/libcontainer/cgroups/fs/freezer.go @@ -27,9 +27,18 @@ func (s *FreezerGroup) Apply(path string, d *cgroupData) error { return join(path, d.pid) } -func (s *FreezerGroup) Set(path string, cgroup *configs.Cgroup) error { +func (s *FreezerGroup) Set(path string, cgroup *configs.Cgroup) (Err error) { switch cgroup.Resources.Freezer { case configs.Frozen: + defer func() { + if Err != nil { + // Freezing failed, and it is bad and dangerous + // to leave the cgroup in FROZEN or FREEZING + // state, so (try to) thaw it back. + _ = fscommon.WriteFile(path, "freezer.state", string(configs.Thawed)) + } + }() + // As per older kernel docs (freezer-subsystem.txt before // kernel commit ef9fe980c6fcc1821), if FREEZING is seen, // userspace should either retry or thaw. While current @@ -75,9 +84,6 @@ func (s *FreezerGroup) Set(path string, cgroup *configs.Cgroup) error { } } // Despite our best efforts, it got stuck in FREEZING. - // Leaving it in this state is bad and dangerous, so - // let's (try to) thaw it back and error out. - _ = fscommon.WriteFile(path, "freezer.state", string(configs.Thawed)) return errors.New("unable to freeze") case configs.Thawed: return fscommon.WriteFile(path, "freezer.state", string(configs.Thawed))