Revert to non-recursive GetPids, add recursive GetAllPids

Signed-off-by: Jimmi Dyson <jimmidyson@gmail.com>

libcontainer/cgroups/cgroups.go

@@ -15,6 +15,9 @@ type Manager interface {
 	// Returns the PIDs inside the cgroup set
 	GetPids() ([]int, error)
 
+	// Returns the PIDs inside the cgroup set & all sub-cgroups
+	GetAllPids() ([]int, error)
+
 	// Returns statistics for the cgroup set
 	GetStats() (*Stats, error)
 

libcontainer/cgroups/fs/apply_raw.go

@@ -217,19 +217,30 @@ func (m *Manager) Freeze(state configs.FreezerState) error {
 }
 
 func (m *Manager) GetPids() ([]int, error) {
-	d, err := getCgroupData(m.Cgroups, 0)
+	dir, err := getCgroupPath(m.Cgroups)
 	if err != nil {
 		return nil, err
 	}
-
-	dir, err := d.path("devices")
-	if err != nil {
-		return nil, err
-	}
-
 	return cgroups.GetPids(dir)
 }
 
+func (m *Manager) GetAllPids() ([]int, error) {
+	dir, err := getCgroupPath(m.Cgroups)
+	if err != nil {
+		return nil, err
+	}
+	return cgroups.GetAllPids(dir)
+}
+
+func getCgroupPath(c *configs.Cgroup) (string, error) {
+	d, err := getCgroupData(c, 0)
+	if err != nil {
+		return "", err
+	}
+
+	return d.path("devices")
+}
+
 func getCgroupData(c *configs.Cgroup, pid int) (*cgroupData, error) {
 	root, err := getCgroupRoot()
 	if err != nil {

libcontainer/cgroups/systemd/apply_nosystemd.go

@@ -26,6 +26,10 @@ func (m *Manager) GetPids() ([]int, error) {
 	return nil, fmt.Errorf("Systemd not supported")
 }
 
+func (m *Manager) GetAllPids() ([]int, error) {
+	return nil, fmt.Errorf("Systemd not supported")
+}
+
 func (m *Manager) Destroy() error {
 	return fmt.Errorf("Systemd not supported")
 }

libcontainer/cgroups/systemd/apply_systemd.go

@@ -440,6 +440,14 @@ func (m *Manager) GetPids() ([]int, error) {
 	return cgroups.GetPids(path)
 }
 
+func (m *Manager) GetAllPids() ([]int, error) {
+	path, err := getSubsystemPath(m.Cgroups, "devices")
+	if err != nil {
+		return nil, err
+	}
+	return cgroups.GetAllPids(path)
+}
+
 func (m *Manager) GetStats() (*cgroups.Stats, error) {
 	m.mu.Lock()
 	defer m.mu.Unlock()

libcontainer/cgroups/utils.go

@@ -323,9 +323,14 @@ func GetHugePageSize() ([]string, error) {
 	return pageSizes, nil
 }
 
-// GetPids returns all pids, that were added to cgroup at path and to all its
+// GetPids returns all pids, that were added to cgroup at path.
-// subcgroups.
 func GetPids(path string) ([]int, error) {
+	return readProcsFile(path)
+}
+
+// GetAllPids returns all pids, that were added to cgroup at path and to all its
+// subcgroups.
+func GetAllPids(path string) ([]int, error) {
 	var pids []int
 	// collect pids from all sub-cgroups
 	err := filepath.Walk(path, func(p string, info os.FileInfo, iErr error) error {

libcontainer/container_linux.go

@@ -129,7 +129,7 @@ func (c *linuxContainer) State() (*State, error) {
 }
 
 func (c *linuxContainer) Processes() ([]int, error) {
-	pids, err := c.cgroupManager.GetPids()
+	pids, err := c.cgroupManager.GetAllPids()
 	if err != nil {
 		return nil, newSystemError(err)
 	}

libcontainer/container_linux_test.go

@@ -12,15 +12,20 @@ import (
 )
 
 type mockCgroupManager struct {
-	pids  []int
+	pids    []int
-	stats *cgroups.Stats
+	allPids []int
-	paths map[string]string
+	stats   *cgroups.Stats
+	paths   map[string]string
 }
 
 func (m *mockCgroupManager) GetPids() ([]int, error) {
 	return m.pids, nil
 }
 
+func (m *mockCgroupManager) GetAllPids() ([]int, error) {
+	return m.allPids, nil
+}
+
 func (m *mockCgroupManager) GetStats() (*cgroups.Stats, error) {
 	return m.stats, nil
 }
@@ -85,7 +90,7 @@ func TestGetContainerPids(t *testing.T) {
 	container := &linuxContainer{
 		id:            "myid",
 		config:        &configs.Config{},
-		cgroupManager: &mockCgroupManager{pids: []int{1, 2, 3}},
+		cgroupManager: &mockCgroupManager{allPids: []int{1, 2, 3}},
 	}
 	pids, err := container.Processes()
 	if err != nil {

libcontainer/init_linux.go

@@ -309,7 +309,7 @@ func killCgroupProcesses(m cgroups.Manager) error {
 	if err := m.Freeze(configs.Frozen); err != nil {
 		logrus.Warn(err)
 	}
-	pids, err := m.GetPids()
+	pids, err := m.GetAllPids()
 	if err != nil {
 		m.Freeze(configs.Thawed)
 		return err