cg2: Don't read cgroup.procs when deleting threaded cg

Reading cgroup.procs seems to return ENOTSUPP when threaded, so check the type of the cg when going to delete and read the relevant file. Signed-off-by: Danny Canter <[email protected]>
containerd · Dec 31, 2023 · 6f5001d · 6f5001d
1 parent 1e05688
commit 6f5001d
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Showing 2 changed files with 25 additions and 5 deletions.
diff --git a/cgroup2/manager.go b/cgroup2/manager.go
@@ -468,13 +468,33 @@ func (c *Manager) fallbackKill() error {
 }
 
 func (c *Manager) Delete() error {
-	// kernel prevents cgroups with running process from being removed, check the tree is empty
-	processes, err := c.Procs(true)
+	var (
+		tasks    []uint64
+		threaded bool
+	)
+	// Kernel prevents cgroups with running process from being removed,
+	// check the tree is empty.
+	//
+	// Pick the right file to read based on the cgs type.
+	cgType, err := c.GetType()
+	if err != nil {
+		if !os.IsNotExist(err) {
+			return err
+		}
+	} else {
+		threaded = cgType == Threaded
+	}
+
+	if threaded {
+		tasks, err = c.Threads(true)
+	} else {
+		tasks, err = c.Procs(true)
+	}
 	if err != nil {
 		return err
 	}
-	if len(processes) > 0 {
-		return fmt.Errorf("cgroups: unable to remove path %q: still contains running processes", c.path)
+	if len(tasks) > 0 {
+		return fmt.Errorf("cgroups: unable to remove path %q: still contains running tasks", c.path)
 	}
 	return remove(c.path)
 }

diff --git a/cgroup2/manager_test.go b/cgroup2/manager_test.go
@@ -284,7 +284,7 @@ func TestCgroupType(t *testing.T) {
 	manager, err := NewManager(defaultCgroup2Path, "/test-type", ToResources(&specs.LinuxResources{}))
 	require.NoError(t, err)
 	t.Cleanup(func() {
-		os.RemoveAll(manager.path)
+		_ = manager.Delete()
 	})
 
 	cgType, err := manager.GetType()