runc/libcontainer/cgroups/fs2/fs2.go

251 lines
6.3 KiB
Go

// +build linux
package fs2
import (
"io/ioutil"
"os"
"path/filepath"
"strings"
"github.com/opencontainers/runc/libcontainer/cgroups"
"github.com/opencontainers/runc/libcontainer/configs"
"github.com/pkg/errors"
)
type manager struct {
config *configs.Cgroup
// dirPath is like "/sys/fs/cgroup/user.slice/user-1001.slice/session-1.scope"
dirPath string
// controllers is content of "cgroup.controllers" file.
// excludes pseudo-controllers ("devices" and "freezer").
controllers map[string]struct{}
rootless bool
}
// NewManager creates a manager for cgroup v2 unified hierarchy.
// dirPath is like "/sys/fs/cgroup/user.slice/user-1001.slice/session-1.scope".
// If dirPath is empty, it is automatically set using config.
func NewManager(config *configs.Cgroup, dirPath string, rootless bool) (cgroups.Manager, error) {
if config == nil {
config = &configs.Cgroup{}
}
if dirPath == "" {
var err error
dirPath, err = defaultDirPath(config)
if err != nil {
return nil, err
}
}
m := &manager{
config: config,
dirPath: dirPath,
rootless: rootless,
}
return m, nil
}
func (m *manager) getControllers() error {
if m.controllers != nil {
return nil
}
file := filepath.Join(m.dirPath, "cgroup.controllers")
data, err := ioutil.ReadFile(file)
if err != nil {
if m.rootless && m.config.Path == "" {
return nil
}
return err
}
fields := strings.Fields(string(data))
m.controllers = make(map[string]struct{}, len(fields))
for _, c := range fields {
m.controllers[c] = struct{}{}
}
return nil
}
func (m *manager) Apply(pid int) error {
if err := CreateCgroupPath(m.dirPath, m.config); err != nil {
// Related tests:
// - "runc create (no limits + no cgrouppath + no permission) succeeds"
// - "runc create (rootless + no limits + cgrouppath + no permission) fails with permission error"
// - "runc create (rootless + limits + no cgrouppath + no permission) fails with informative error"
if m.rootless {
if m.config.Path == "" {
cl, clErr := neededControllers(m.config)
if clErr == nil && len(cl) == 0 {
return nil
}
return errors.Wrap(err, "rootless needs no limits + no cgrouppath when no permission is granted for cgroups")
}
}
return err
}
if err := cgroups.WriteCgroupProc(m.dirPath, pid); err != nil {
return err
}
return nil
}
func (m *manager) GetPids() ([]int, error) {
return cgroups.GetPids(m.dirPath)
}
func (m *manager) GetAllPids() ([]int, error) {
return cgroups.GetAllPids(m.dirPath)
}
func (m *manager) GetStats() (*cgroups.Stats, error) {
var (
errs []error
)
st := cgroups.NewStats()
if err := m.getControllers(); err != nil {
return st, err
}
// pids (since kernel 4.5)
if _, ok := m.controllers["pids"]; ok {
if err := statPids(m.dirPath, st); err != nil {
errs = append(errs, err)
}
} else {
if err := statPidsWithoutController(m.dirPath, st); err != nil {
errs = append(errs, err)
}
}
// memory (since kernel 4.5)
if _, ok := m.controllers["memory"]; ok {
if err := statMemory(m.dirPath, st); err != nil {
errs = append(errs, err)
}
}
// io (since kernel 4.5)
if _, ok := m.controllers["io"]; ok {
if err := statIo(m.dirPath, st); err != nil {
errs = append(errs, err)
}
}
// cpu (since kernel 4.15)
if _, ok := m.controllers["cpu"]; ok {
if err := statCpu(m.dirPath, st); err != nil {
errs = append(errs, err)
}
}
// hugetlb (since kernel 5.6)
if _, ok := m.controllers["hugetlb"]; ok {
if err := statHugeTlb(m.dirPath, st); err != nil {
errs = append(errs, err)
}
}
if len(errs) > 0 && !m.rootless {
return st, errors.Errorf("error while statting cgroup v2: %+v", errs)
}
return st, nil
}
func (m *manager) Freeze(state configs.FreezerState) error {
if err := setFreezer(m.dirPath, state); err != nil {
return err
}
m.config.Resources.Freezer = state
return nil
}
func (m *manager) Destroy() error {
if err := os.Remove(m.dirPath); err != nil && !os.IsNotExist(err) {
return err
}
return nil
}
// GetPaths is for compatibility purpose and should be removed in future
func (m *manager) GetPaths() map[string]string {
_ = m.getControllers()
paths := map[string]string{
// pseudo-controller for compatibility
"devices": m.dirPath,
"freezer": m.dirPath,
}
for c := range m.controllers {
paths[c] = m.dirPath
}
return paths
}
func (m *manager) GetUnifiedPath() (string, error) {
return m.dirPath, nil
}
func (m *manager) Set(container *configs.Config) error {
if container == nil || container.Cgroups == nil {
return nil
}
if err := m.getControllers(); err != nil {
return err
}
var errs []error
// pids (since kernel 4.5)
if _, ok := m.controllers["pids"]; ok {
if err := setPids(m.dirPath, container.Cgroups); err != nil {
errs = append(errs, err)
}
}
// memory (since kernel 4.5)
if _, ok := m.controllers["memory"]; ok {
if err := setMemory(m.dirPath, container.Cgroups); err != nil {
errs = append(errs, err)
}
}
// io (since kernel 4.5)
if _, ok := m.controllers["io"]; ok {
if err := setIo(m.dirPath, container.Cgroups); err != nil {
errs = append(errs, err)
}
}
// cpu (since kernel 4.15)
if _, ok := m.controllers["cpu"]; ok {
if err := setCpu(m.dirPath, container.Cgroups); err != nil {
errs = append(errs, err)
}
}
// devices (since kernel 4.15, pseudo-controller)
//
// When m.Rootless is true, errors from the device subsystem are ignored because it is really not expected to work.
// However, errors from other subsystems are not ignored.
// see @test "runc create (rootless + limits + no cgrouppath + no permission) fails with informative error"
if err := setDevices(m.dirPath, container.Cgroups); err != nil && !m.rootless {
errs = append(errs, err)
}
// cpuset (since kernel 5.0)
if _, ok := m.controllers["cpuset"]; ok {
if err := setCpuset(m.dirPath, container.Cgroups); err != nil {
errs = append(errs, err)
}
}
// hugetlb (since kernel 5.6)
if _, ok := m.controllers["hugetlb"]; ok {
if err := setHugeTlb(m.dirPath, container.Cgroups); err != nil {
errs = append(errs, err)
}
}
// freezer (since kernel 5.2, pseudo-controller)
if err := setFreezer(m.dirPath, container.Cgroups.Freezer); err != nil {
errs = append(errs, err)
}
if len(errs) > 0 {
return errors.Errorf("error while setting cgroup v2: %+v", errs)
}
m.config = container.Cgroups
return nil
}
func (m *manager) GetCgroups() (*configs.Cgroup, error) {
return m.config, nil
}