cgroup1 delete: proceed to the next subsystem when a cgroup is not found

cgroup1/cgroup.go

@@ -41,7 +41,7 @@ func New(path Path, resources *specs.LinuxResources, opts ...InitOpts) (Cgroup,
 			return nil, err
 		}
 	}
-	subsystems, err := config.hiearchy()
+	subsystems, err := config.hierarchy()
 	if err != nil {
 		return nil, err
 	}
@@ -79,7 +79,7 @@ func Load(path Path, opts ...InitOpts) (Cgroup, error) {
 		}
 	}
 	var activeSubsystems []Subsystem
-	subsystems, err := config.hiearchy()
+	subsystems, err := config.hierarchy()
 	if err != nil {
 		return nil, err
 	}
@@ -259,6 +259,10 @@ func (c *cgroup) Delete() error {
 		// kernel prevents cgroups with running process from being removed, check the tree is empty
 		procs, err := c.processes(s.Name(), true, cgroupProcs)
 		if err != nil {
+			// if the control group does not exist within a subsystem, then proceed to the next subsystem
+			if errors.Is(err, os.ErrNotExist) {
+				continue
+			}
 			return err
 		}
 		if len(procs) > 0 {

cgroup1/cgroup_test.go

@@ -459,6 +459,13 @@ func TestDelete(t *testing.T) {
 		t.Error(err)
 		return
 	}
+
+	err = mock.symLink()
+	if err != nil {
+		t.Error(err)
+		return
+	}
+
 	if err := control.Delete(); err != nil {
 		t.Error(err)
 	}

cgroup1/mock_test.go

@@ -73,3 +73,21 @@ func (m *mockCgroup) delete() error {
 func (m *mockCgroup) hierarchy() ([]Subsystem, error) {
 	return m.subsystems, nil
 }
+
+// symLink() creates a symlink between net_cls and net_prio for testing
+// On certain Linux systems, there's a symlink from both net_cls and net_prio to "net_cls,net_prio"
+// Since we don't have a subsystem defined for "net_cls,net_prio",
+// we mock this behavior by creating a symlink directly between net_cls and net_prio
+func (m *mockCgroup) symLink() error {
+	netCLS := filepath.Join(m.root, string(NetCLS))
+	netPrio := filepath.Join(m.root, string(NetPrio))
+	// remove netCLS before creating a symlink
+	if err := os.RemoveAll(netCLS); err != nil {
+		return err
+	}
+	// create symlink between net_cls and net_prio
+	if err := os.Symlink(netPrio, netCLS); err != nil {
+		return err
+	}
+	return nil
+}

cgroup1/opts.go

@@ -36,13 +36,13 @@ type InitOpts func(*InitConfig) error
 type InitConfig struct {
 	// InitCheck can be used to check initialization errors from the subsystem
 	InitCheck InitCheck
-	hiearchy  Hierarchy
+	hierarchy Hierarchy
 }
 
 func newInitConfig() *InitConfig {
 	return &InitConfig{
 		InitCheck: RequireDevices,
-		hiearchy:  Default,
+		hierarchy: Default,
 	}
 }
 
@@ -66,7 +66,7 @@ func RequireDevices(s Subsystem, _ Path, _ error) error {
 // The default list is coming from /proc/self/mountinfo.
 func WithHiearchy(h Hierarchy) InitOpts {
 	return func(c *InitConfig) error {
-		c.hiearchy = h
+		c.hierarchy = h
 		return nil
 	}
 }

cgroup1/v1.go

@@ -45,7 +45,7 @@ func Default() ([]Subsystem, error) {
 }
 
 // v1MountPoint returns the mount point where the cgroup
-// mountpoints are mounted in a single hiearchy
+// mountpoints are mounted in a single hierarchy
 func v1MountPoint() (string, error) {
 	f, err := os.Open("/proc/self/mountinfo")
 	if err != nil {