cgroup2: split fs2 from fs

libcontainer/cgroups/fs/apply_raw.go

@@ -5,7 +5,6 @@ package fs
 import (
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"sync"
@@ -33,15 +32,6 @@ var (
 		&FreezerGroup{},
 		&NameGroup{GroupName: "name=systemd", Join: true},
 	}
-	subsystemsUnified = subsystemSet{
-		&CpusetGroupV2{},
-		&FreezerGroupV2{},
-		&CpuGroupV2{},
-		&MemoryGroupV2{},
-		&IOGroupV2{},
-		&PidsGroupV2{},
-		&DevicesGroupV2{},
-	}
 	HugePageSizes, _ = cgroups.GetHugePageSize()
 )
 
@@ -139,9 +129,6 @@ func isIgnorableError(rootless bool, err error) bool {
 }
 
 func (m *Manager) getSubsystems() subsystemSet {
-	if cgroups.IsCgroup2UnifiedMode() {
-		return subsystemsUnified
-	}
 	return subsystemsLegacy
 }
 
@@ -226,25 +213,7 @@ func (m *Manager) GetPaths() map[string]string {
 }
 
 func (m *Manager) GetUnifiedPath() (string, error) {
-	if !cgroups.IsCgroup2UnifiedMode() {
-		return "", errors.New("unified path is only supported when running in unified mode")
-	}
-	unifiedPath := ""
-	m.mu.Lock()
-	defer m.mu.Unlock()
-	for k, v := range m.Paths {
-		if unifiedPath == "" {
-			unifiedPath = v
-		} else if v != unifiedPath {
-			return unifiedPath,
-				errors.Errorf("expected %q path to be unified path %q, got %q", k, unifiedPath, v)
-		}
-	}
-	if unifiedPath == "" {
-		// FIXME: unified path could be detected even when no controller is available
-		return unifiedPath, errors.New("cannot detect unified path")
-	}
-	return unifiedPath, nil
+	return "", errors.New("unified path is only supported when running in unified mode")
 }
 
 func (m *Manager) GetStats() (*cgroups.Stats, error) {
@@ -325,25 +294,11 @@ func (m *Manager) Freeze(state configs.FreezerState) error {
 }
 
 func (m *Manager) GetPids() ([]int, error) {
-	if cgroups.IsCgroup2UnifiedMode() {
-		path, err := m.GetUnifiedPath()
-		if err != nil {
-			return nil, err
-		}
-		return cgroups.GetPids(path)
-	}
 	paths := m.GetPaths()
 	return cgroups.GetPids(paths["devices"])
 }
 
 func (m *Manager) GetAllPids() ([]int, error) {
-	if cgroups.IsCgroup2UnifiedMode() {
-		path, err := m.GetUnifiedPath()
-		if err != nil {
-			return nil, err
-		}
-		return cgroups.GetAllPids(path)
-	}
 	paths := m.GetPaths()
 	return cgroups.GetAllPids(paths["devices"])
 }
@@ -414,23 +369,6 @@ func (raw *cgroupData) join(subsystem string) (string, error) {
 	return path, nil
 }
 
-func writeFile(dir, file, data string) error {
-	// Normally dir should not be empty, one case is that cgroup subsystem
-	// is not mounted, we will get empty dir, and we want it fail here.
-	if dir == "" {
-		return fmt.Errorf("no such directory for %s", file)
-	}
-	if err := ioutil.WriteFile(filepath.Join(dir, file), []byte(data), 0700); err != nil {
-		return fmt.Errorf("failed to write %v to %v: %v", data, file, err)
-	}
-	return nil
-}
-
-func readFile(dir, file string) (string, error) {
-	data, err := ioutil.ReadFile(filepath.Join(dir, file))
-	return string(data), err
-}
-
 func removePath(p string, err error) error {
 	if err != nil {
 		return err

libcontainer/cgroups/fs/blkio.go

@@ -11,6 +11,7 @@ import (
 	"strings"
 
 	"github.com/opencontainers/runc/libcontainer/cgroups"
+	"github.com/opencontainers/runc/libcontainer/cgroups/fscommon"
 	"github.com/opencontainers/runc/libcontainer/configs"
 )
 
@@ -31,41 +32,41 @@ func (s *BlkioGroup) Apply(d *cgroupData) error {
 
 func (s *BlkioGroup) Set(path string, cgroup *configs.Cgroup) error {
 	if cgroup.Resources.BlkioWeight != 0 {
-		if err := writeFile(path, "blkio.weight", strconv.FormatUint(uint64(cgroup.Resources.BlkioWeight), 10)); err != nil {
+		if err := fscommon.WriteFile(path, "blkio.weight", strconv.FormatUint(uint64(cgroup.Resources.BlkioWeight), 10)); err != nil {
 			return err
 		}
 	}
 
 	if cgroup.Resources.BlkioLeafWeight != 0 {
-		if err := writeFile(path, "blkio.leaf_weight", strconv.FormatUint(uint64(cgroup.Resources.BlkioLeafWeight), 10)); err != nil {
+		if err := fscommon.WriteFile(path, "blkio.leaf_weight", strconv.FormatUint(uint64(cgroup.Resources.BlkioLeafWeight), 10)); err != nil {
 			return err
 		}
 	}
 	for _, wd := range cgroup.Resources.BlkioWeightDevice {
-		if err := writeFile(path, "blkio.weight_device", wd.WeightString()); err != nil {
+		if err := fscommon.WriteFile(path, "blkio.weight_device", wd.WeightString()); err != nil {
 			return err
 		}
-		if err := writeFile(path, "blkio.leaf_weight_device", wd.LeafWeightString()); err != nil {
+		if err := fscommon.WriteFile(path, "blkio.leaf_weight_device", wd.LeafWeightString()); err != nil {
 			return err
 		}
 	}
 	for _, td := range cgroup.Resources.BlkioThrottleReadBpsDevice {
-		if err := writeFile(path, "blkio.throttle.read_bps_device", td.String()); err != nil {
+		if err := fscommon.WriteFile(path, "blkio.throttle.read_bps_device", td.String()); err != nil {
 			return err
 		}
 	}
 	for _, td := range cgroup.Resources.BlkioThrottleWriteBpsDevice {
-		if err := writeFile(path, "blkio.throttle.write_bps_device", td.String()); err != nil {
+		if err := fscommon.WriteFile(path, "blkio.throttle.write_bps_device", td.String()); err != nil {
 			return err
 		}
 	}
 	for _, td := range cgroup.Resources.BlkioThrottleReadIOPSDevice {
-		if err := writeFile(path, "blkio.throttle.read_iops_device", td.String()); err != nil {
+		if err := fscommon.WriteFile(path, "blkio.throttle.read_iops_device", td.String()); err != nil {
 			return err
 		}
 	}
 	for _, td := range cgroup.Resources.BlkioThrottleWriteIOPSDevice {
-		if err := writeFile(path, "blkio.throttle.write_iops_device", td.String()); err != nil {
+		if err := fscommon.WriteFile(path, "blkio.throttle.write_iops_device", td.String()); err != nil {
 			return err
 		}
 	}

libcontainer/cgroups/fs/blkio_test.go

@@ -7,6 +7,7 @@ import (
 	"testing"
 
 	"github.com/opencontainers/runc/libcontainer/cgroups"
+	"github.com/opencontainers/runc/libcontainer/cgroups/fscommon"
 	"github.com/opencontainers/runc/libcontainer/configs"
 )
 
@@ -95,7 +96,7 @@ func TestBlkioSetWeight(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	value, err := getCgroupParamUint(helper.CgroupPath, "blkio.weight")
+	value, err := fscommon.GetCgroupParamUint(helper.CgroupPath, "blkio.weight")
 	if err != nil {
 		t.Fatalf("Failed to parse blkio.weight - %s", err)
 	}
@@ -126,7 +127,7 @@ func TestBlkioSetWeightDevice(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	value, err := getCgroupParamString(helper.CgroupPath, "blkio.weight_device")
+	value, err := fscommon.GetCgroupParamString(helper.CgroupPath, "blkio.weight_device")
 	if err != nil {
 		t.Fatalf("Failed to parse blkio.weight_device - %s", err)
 	}
@@ -163,7 +164,7 @@ func TestBlkioSetMultipleWeightDevice(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	value, err := getCgroupParamString(helper.CgroupPath, "blkio.weight_device")
+	value, err := fscommon.GetCgroupParamString(helper.CgroupPath, "blkio.weight_device")
 	if err != nil {
 		t.Fatalf("Failed to parse blkio.weight_device - %s", err)
 	}
@@ -535,7 +536,7 @@ func TestBlkioSetThrottleReadBpsDevice(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	value, err := getCgroupParamString(helper.CgroupPath, "blkio.throttle.read_bps_device")
+	value, err := fscommon.GetCgroupParamString(helper.CgroupPath, "blkio.throttle.read_bps_device")
 	if err != nil {
 		t.Fatalf("Failed to parse blkio.throttle.read_bps_device - %s", err)
 	}
@@ -565,7 +566,7 @@ func TestBlkioSetThrottleWriteBpsDevice(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	value, err := getCgroupParamString(helper.CgroupPath, "blkio.throttle.write_bps_device")
+	value, err := fscommon.GetCgroupParamString(helper.CgroupPath, "blkio.throttle.write_bps_device")
 	if err != nil {
 		t.Fatalf("Failed to parse blkio.throttle.write_bps_device - %s", err)
 	}
@@ -595,7 +596,7 @@ func TestBlkioSetThrottleReadIOpsDevice(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	value, err := getCgroupParamString(helper.CgroupPath, "blkio.throttle.read_iops_device")
+	value, err := fscommon.GetCgroupParamString(helper.CgroupPath, "blkio.throttle.read_iops_device")
 	if err != nil {
 		t.Fatalf("Failed to parse blkio.throttle.read_iops_device - %s", err)
 	}
@@ -625,7 +626,7 @@ func TestBlkioSetThrottleWriteIOpsDevice(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	value, err := getCgroupParamString(helper.CgroupPath, "blkio.throttle.write_iops_device")
+	value, err := fscommon.GetCgroupParamString(helper.CgroupPath, "blkio.throttle.write_iops_device")
 	if err != nil {
 		t.Fatalf("Failed to parse blkio.throttle.write_iops_device - %s", err)
 	}

libcontainer/cgroups/fs/cpu.go

@@ -9,6 +9,7 @@ import (
 	"strconv"
 
 	"github.com/opencontainers/runc/libcontainer/cgroups"
+	"github.com/opencontainers/runc/libcontainer/cgroups/fscommon"
 	"github.com/opencontainers/runc/libcontainer/configs"
 )
 
@@ -51,12 +52,12 @@ func (s *CpuGroup) ApplyDir(path string, cgroup *configs.Cgroup, pid int) error
 
 func (s *CpuGroup) SetRtSched(path string, cgroup *configs.Cgroup) error {
 	if cgroup.Resources.CpuRtPeriod != 0 {
-		if err := writeFile(path, "cpu.rt_period_us", strconv.FormatUint(cgroup.Resources.CpuRtPeriod, 10)); err != nil {
+		if err := fscommon.WriteFile(path, "cpu.rt_period_us", strconv.FormatUint(cgroup.Resources.CpuRtPeriod, 10)); err != nil {
 			return err
 		}
 	}
 	if cgroup.Resources.CpuRtRuntime != 0 {
-		if err := writeFile(path, "cpu.rt_runtime_us", strconv.FormatInt(cgroup.Resources.CpuRtRuntime, 10)); err != nil {
+		if err := fscommon.WriteFile(path, "cpu.rt_runtime_us", strconv.FormatInt(cgroup.Resources.CpuRtRuntime, 10)); err != nil {
 			return err
 		}
 	}
@@ -65,17 +66,17 @@ func (s *CpuGroup) SetRtSched(path string, cgroup *configs.Cgroup) error {
 
 func (s *CpuGroup) Set(path string, cgroup *configs.Cgroup) error {
 	if cgroup.Resources.CpuShares != 0 {
-		if err := writeFile(path, "cpu.shares", strconv.FormatUint(cgroup.Resources.CpuShares, 10)); err != nil {
+		if err := fscommon.WriteFile(path, "cpu.shares", strconv.FormatUint(cgroup.Resources.CpuShares, 10)); err != nil {
 			return err
 		}
 	}
 	if cgroup.Resources.CpuPeriod != 0 {
-		if err := writeFile(path, "cpu.cfs_period_us", strconv.FormatUint(cgroup.Resources.CpuPeriod, 10)); err != nil {
+		if err := fscommon.WriteFile(path, "cpu.cfs_period_us", strconv.FormatUint(cgroup.Resources.CpuPeriod, 10)); err != nil {
 			return err
 		}
 	}
 	if cgroup.Resources.CpuQuota != 0 {
-		if err := writeFile(path, "cpu.cfs_quota_us", strconv.FormatInt(cgroup.Resources.CpuQuota, 10)); err != nil {
+		if err := fscommon.WriteFile(path, "cpu.cfs_quota_us", strconv.FormatInt(cgroup.Resources.CpuQuota, 10)); err != nil {
 			return err
 		}
 	}
@@ -98,7 +99,7 @@ func (s *CpuGroup) GetStats(path string, stats *cgroups.Stats) error {
 
 	sc := bufio.NewScanner(f)
 	for sc.Scan() {
-		t, v, err := getCgroupParamKeyValue(sc.Text())
+		t, v, err := fscommon.GetCgroupParamKeyValue(sc.Text())
 		if err != nil {
 			return err
 		}

libcontainer/cgroups/fs/cpu_test.go

@@ -8,6 +8,7 @@ import (
 	"testing"
 
 	"github.com/opencontainers/runc/libcontainer/cgroups"
+	"github.com/opencontainers/runc/libcontainer/cgroups/fscommon"
 )
 
 func TestCpuSetShares(t *testing.T) {
@@ -29,7 +30,7 @@ func TestCpuSetShares(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	value, err := getCgroupParamUint(helper.CgroupPath, "cpu.shares")
+	value, err := fscommon.GetCgroupParamUint(helper.CgroupPath, "cpu.shares")
 	if err != nil {
 		t.Fatalf("Failed to parse cpu.shares - %s", err)
 	}
@@ -70,29 +71,29 @@ func TestCpuSetBandWidth(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	quota, err := getCgroupParamUint(helper.CgroupPath, "cpu.cfs_quota_us")
+	quota, err := fscommon.GetCgroupParamUint(helper.CgroupPath, "cpu.cfs_quota_us")
 	if err != nil {
 		t.Fatalf("Failed to parse cpu.cfs_quota_us - %s", err)
 	}
 	if quota != quotaAfter {
 		t.Fatal("Got the wrong value, set cpu.cfs_quota_us failed.")
 	}
 
-	period, err := getCgroupParamUint(helper.CgroupPath, "cpu.cfs_period_us")
+	period, err := fscommon.GetCgroupParamUint(helper.CgroupPath, "cpu.cfs_period_us")
 	if err != nil {
 		t.Fatalf("Failed to parse cpu.cfs_period_us - %s", err)
 	}
 	if period != periodAfter {
 		t.Fatal("Got the wrong value, set cpu.cfs_period_us failed.")
 	}
-	rtRuntime, err := getCgroupParamUint(helper.CgroupPath, "cpu.rt_runtime_us")
+	rtRuntime, err := fscommon.GetCgroupParamUint(helper.CgroupPath, "cpu.rt_runtime_us")
 	if err != nil {
 		t.Fatalf("Failed to parse cpu.rt_runtime_us - %s", err)
 	}
 	if rtRuntime != rtRuntimeAfter {
 		t.Fatal("Got the wrong value, set cpu.rt_runtime_us failed.")
 	}
-	rtPeriod, err := getCgroupParamUint(helper.CgroupPath, "cpu.rt_period_us")
+	rtPeriod, err := fscommon.GetCgroupParamUint(helper.CgroupPath, "cpu.rt_period_us")
 	if err != nil {
 		t.Fatalf("Failed to parse cpu.rt_period_us - %s", err)
 	}
@@ -185,21 +186,21 @@ func TestCpuSetRtSchedAtApply(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	rtRuntime, err := getCgroupParamUint(helper.CgroupPath, "cpu.rt_runtime_us")
+	rtRuntime, err := fscommon.GetCgroupParamUint(helper.CgroupPath, "cpu.rt_runtime_us")
 	if err != nil {
 		t.Fatalf("Failed to parse cpu.rt_runtime_us - %s", err)
 	}
 	if rtRuntime != rtRuntimeAfter {
 		t.Fatal("Got the wrong value, set cpu.rt_runtime_us failed.")
 	}
-	rtPeriod, err := getCgroupParamUint(helper.CgroupPath, "cpu.rt_period_us")
+	rtPeriod, err := fscommon.GetCgroupParamUint(helper.CgroupPath, "cpu.rt_period_us")
 	if err != nil {
 		t.Fatalf("Failed to parse cpu.rt_period_us - %s", err)
 	}
 	if rtPeriod != rtPeriodAfter {
 		t.Fatal("Got the wrong value, set cpu.rt_period_us failed.")
 	}
-	pid, err := getCgroupParamUint(helper.CgroupPath, "cgroup.procs")
+	pid, err := fscommon.GetCgroupParamUint(helper.CgroupPath, "cgroup.procs")
 	if err != nil {
 		t.Fatalf("Failed to parse cgroup.procs - %s", err)
 	}