Merge pull request #642 from crosbymichael/parent-cgroup

Ensure all parent dirs are properly setup

cgroups/fs/cpuset.go

@@ -21,7 +21,6 @@ func (s *CpusetGroup) Apply(d *data) error {
 	if err != nil && !cgroups.IsNotFound(err) {
 		return err
 	}
-
 	return s.ApplyDir(dir, d.c, d.pid)
 }
 
@@ -31,13 +30,11 @@ func (s *CpusetGroup) Set(path string, cgroup *configs.Cgroup) error {
 			return err
 		}
 	}
-
 	if cgroup.CpusetMems != "" {
 		if err := writeFile(path, "cpuset.mems", cgroup.CpusetMems); err != nil {
 			return err
 		}
 	}
-
 	return nil
 }
 
@@ -55,10 +52,13 @@ func (s *CpusetGroup) ApplyDir(dir string, cgroup *configs.Cgroup, pid int) erro
 	if dir == "" {
 		return nil
 	}
-	if err := s.ensureParent(dir); err != nil {
+	root, err := getCgroupRoot()
+	if err != nil {
+		return err
+	}
+	if err := s.ensureParent(dir, root); err != nil {
 		return err
 	}
-
 	// because we are not using d.join we need to place the pid into the procs file
 	// unlike the other subsystems
 	if err := writeFile(dir, "cgroup.procs", strconv.Itoa(pid)); err != nil {
@@ -84,22 +84,17 @@ func (s *CpusetGroup) getSubsystemSettings(parent string) (cpus []byte, mems []b
 	return cpus, mems, nil
 }
 
-// ensureParent ensures that the parent directory of current is created
-// with the proper cpus and mems files copied from it's parent if the values
-// are a file with a new line char
-func (s *CpusetGroup) ensureParent(current string) error {
+// ensureParent makes sure that the parent directory of current is created
+// and populated with the proper cpus and mems files copied from
+// it's parent.
+func (s *CpusetGroup) ensureParent(current, root string) error {
 	parent := filepath.Dir(current)
-
-	if _, err := os.Stat(parent); err != nil {
-		if !os.IsNotExist(err) {
-			return err
-		}
-
-		if err := s.ensureParent(parent); err != nil {
-			return err
-		}
+	if filepath.Clean(parent) == root {
+		return nil
+	}
+	if err := s.ensureParent(parent, root); err != nil {
+		return err
 	}
-
 	if err := os.MkdirAll(current, 0755); err != nil && !os.IsExist(err) {
 		return err
 	}