Merge pull request #3024 from kolyshkin/fscommon-mv

libct/cg: mv fscommon.{Open,Read,Write}File to cgroups

libcontainer/cgroups/fscommon/open.go → libcontainer/cgroups/file.go

@@ -1,6 +1,7 @@
-package fscommon
+package cgroups
 
 import (
+	"bytes"
 	"os"
 	"strings"
 	"sync"
@@ -10,6 +11,54 @@ import (
 	"golang.org/x/sys/unix"
 )
 
+// OpenFile opens a cgroup file in a given dir with given flags.
+// It is supposed to be used for cgroup files only.
+func OpenFile(dir, file string, flags int) (*os.File, error) {
+	if dir == "" {
+		return nil, errors.Errorf("no directory specified for %s", file)
+	}
+	return openFile(dir, file, flags)
+}
+
+// ReadFile reads data from a cgroup file in dir.
+// It is supposed to be used for cgroup files only.
+func ReadFile(dir, file string) (string, error) {
+	fd, err := OpenFile(dir, file, unix.O_RDONLY)
+	if err != nil {
+		return "", err
+	}
+	defer fd.Close()
+	var buf bytes.Buffer
+
+	_, err = buf.ReadFrom(fd)
+	return buf.String(), err
+}
+
+// WriteFile writes data to a cgroup file in dir.
+// It is supposed to be used for cgroup files only.
+func WriteFile(dir, file, data string) error {
+	fd, err := OpenFile(dir, file, unix.O_WRONLY)
+	if err != nil {
+		return err
+	}
+	defer fd.Close()
+	if err := retryingWriteFile(fd, data); err != nil {
+		return errors.Wrapf(err, "failed to write %q", data)
+	}
+	return nil
+}
+
+func retryingWriteFile(fd *os.File, data string) error {
+	for {
+		_, err := fd.Write([]byte(data))
+		if errors.Is(err, unix.EINTR) {
+			logrus.Infof("interrupted while writing %s to %s", data, fd.Name())
+			continue
+		}
+		return err
+	}
+}
+
 const (
 	cgroupfsDir    = "/sys/fs/cgroup"
 	cgroupfsPrefix = cgroupfsDir + "/"
@@ -60,10 +109,7 @@ func prepareOpenat2() error {
 
 // OpenFile opens a cgroup file in a given dir with given flags.
 // It is supposed to be used for cgroup files only.
-func OpenFile(dir, file string, flags int) (*os.File, error) {
-	if dir == "" {
-		return nil, errors.Errorf("no directory specified for %s", file)
-	}
+func openFile(dir, file string, flags int) (*os.File, error) {
 	mode := os.FileMode(0)
 	if TestMode && flags&os.O_WRONLY != 0 {
 		// "emulate" cgroup fs for unit tests

libcontainer/cgroups/fscommon/fscommon_test.go → libcontainer/cgroups/file_test.go

@@ -1,6 +1,6 @@
 // +build linux
 
-package fscommon
+package cgroups
 
 import (
 	"fmt"

libcontainer/cgroups/fs/blkio.go

@@ -11,7 +11,6 @@ import (
 	"strings"
 
 	"github.com/opencontainers/runc/libcontainer/cgroups"
-	"github.com/opencontainers/runc/libcontainer/cgroups/fscommon"
 	"github.com/opencontainers/runc/libcontainer/configs"
 )
 
@@ -31,41 +30,41 @@ func (s *BlkioGroup) Apply(path string, d *cgroupData) error {
 func (s *BlkioGroup) Set(path string, r *configs.Resources) error {
 	s.detectWeightFilenames(path)
 	if r.BlkioWeight != 0 {
-		if err := fscommon.WriteFile(path, s.weightFilename, strconv.FormatUint(uint64(r.BlkioWeight), 10)); err != nil {
+		if err := cgroups.WriteFile(path, s.weightFilename, strconv.FormatUint(uint64(r.BlkioWeight), 10)); err != nil {
 			return err
 		}
 	}
 
 	if r.BlkioLeafWeight != 0 {
-		if err := fscommon.WriteFile(path, "blkio.leaf_weight", strconv.FormatUint(uint64(r.BlkioLeafWeight), 10)); err != nil {
+		if err := cgroups.WriteFile(path, "blkio.leaf_weight", strconv.FormatUint(uint64(r.BlkioLeafWeight), 10)); err != nil {
 			return err
 		}
 	}
 	for _, wd := range r.BlkioWeightDevice {
-		if err := fscommon.WriteFile(path, s.weightDeviceFilename, wd.WeightString()); err != nil {
+		if err := cgroups.WriteFile(path, s.weightDeviceFilename, wd.WeightString()); err != nil {
 			return err
 		}
-		if err := fscommon.WriteFile(path, "blkio.leaf_weight_device", wd.LeafWeightString()); err != nil {
+		if err := cgroups.WriteFile(path, "blkio.leaf_weight_device", wd.LeafWeightString()); err != nil {
 			return err
 		}
 	}
 	for _, td := range r.BlkioThrottleReadBpsDevice {
-		if err := fscommon.WriteFile(path, "blkio.throttle.read_bps_device", td.String()); err != nil {
+		if err := cgroups.WriteFile(path, "blkio.throttle.read_bps_device", td.String()); err != nil {
 			return err
 		}
 	}
 	for _, td := range r.BlkioThrottleWriteBpsDevice {
-		if err := fscommon.WriteFile(path, "blkio.throttle.write_bps_device", td.String()); err != nil {
+		if err := cgroups.WriteFile(path, "blkio.throttle.write_bps_device", td.String()); err != nil {
 			return err
 		}
 	}
 	for _, td := range r.BlkioThrottleReadIOPSDevice {
-		if err := fscommon.WriteFile(path, "blkio.throttle.read_iops_device", td.String()); err != nil {
+		if err := cgroups.WriteFile(path, "blkio.throttle.read_iops_device", td.String()); err != nil {
 			return err
 		}
 	}
 	for _, td := range r.BlkioThrottleWriteIOPSDevice {
-		if err := fscommon.WriteFile(path, "blkio.throttle.write_iops_device", td.String()); err != nil {
+		if err := cgroups.WriteFile(path, "blkio.throttle.write_iops_device", td.String()); err != nil {
 			return err
 		}
 	}
@@ -110,7 +109,7 @@ func splitBlkioStatLine(r rune) bool {
 
 func getBlkioStat(dir, file string) ([]cgroups.BlkioStatEntry, error) {
 	var blkioStats []cgroups.BlkioStatEntry
-	f, err := fscommon.OpenFile(dir, file, os.O_RDONLY)
+	f, err := cgroups.OpenFile(dir, file, os.O_RDONLY)
 	if err != nil {
 		if os.IsNotExist(err) {
 			return blkioStats, nil

libcontainer/cgroups/fs/cpu.go

@@ -41,12 +41,12 @@ func (s *CpuGroup) Apply(path string, d *cgroupData) error {
 
 func (s *CpuGroup) SetRtSched(path string, r *configs.Resources) error {
 	if r.CpuRtPeriod != 0 {
-		if err := fscommon.WriteFile(path, "cpu.rt_period_us", strconv.FormatUint(r.CpuRtPeriod, 10)); err != nil {
+		if err := cgroups.WriteFile(path, "cpu.rt_period_us", strconv.FormatUint(r.CpuRtPeriod, 10)); err != nil {
 			return err
 		}
 	}
 	if r.CpuRtRuntime != 0 {
-		if err := fscommon.WriteFile(path, "cpu.rt_runtime_us", strconv.FormatInt(r.CpuRtRuntime, 10)); err != nil {
+		if err := cgroups.WriteFile(path, "cpu.rt_runtime_us", strconv.FormatInt(r.CpuRtRuntime, 10)); err != nil {
 			return err
 		}
 	}
@@ -56,7 +56,7 @@ func (s *CpuGroup) SetRtSched(path string, r *configs.Resources) error {
 func (s *CpuGroup) Set(path string, r *configs.Resources) error {
 	if r.CpuShares != 0 {
 		shares := r.CpuShares
-		if err := fscommon.WriteFile(path, "cpu.shares", strconv.FormatUint(shares, 10)); err != nil {
+		if err := cgroups.WriteFile(path, "cpu.shares", strconv.FormatUint(shares, 10)); err != nil {
 			return err
 		}
 		// read it back
@@ -72,20 +72,20 @@ func (s *CpuGroup) Set(path string, r *configs.Resources) error {
 		}
 	}
 	if r.CpuPeriod != 0 {
-		if err := fscommon.WriteFile(path, "cpu.cfs_period_us", strconv.FormatUint(r.CpuPeriod, 10)); err != nil {
+		if err := cgroups.WriteFile(path, "cpu.cfs_period_us", strconv.FormatUint(r.CpuPeriod, 10)); err != nil {
 			return err
 		}
 	}
 	if r.CpuQuota != 0 {
-		if err := fscommon.WriteFile(path, "cpu.cfs_quota_us", strconv.FormatInt(r.CpuQuota, 10)); err != nil {
+		if err := cgroups.WriteFile(path, "cpu.cfs_quota_us", strconv.FormatInt(r.CpuQuota, 10)); err != nil {
 			return err
 		}
 	}
 	return s.SetRtSched(path, r)
 }
 
 func (s *CpuGroup) GetStats(path string, stats *cgroups.Stats) error {
-	f, err := fscommon.OpenFile(path, "cpu.stat", os.O_RDONLY)
+	f, err := cgroups.OpenFile(path, "cpu.stat", os.O_RDONLY)
 	if err != nil {
 		if os.IsNotExist(err) {
 			return nil

libcontainer/cgroups/fs/cpuacct.go

@@ -90,7 +90,7 @@ func getCpuUsageBreakdown(path string) (uint64, uint64, error) {
 	// Expected format:
 	// user <usage in ticks>
 	// system <usage in ticks>
-	data, err := fscommon.ReadFile(path, cgroupCpuacctStat)
+	data, err := cgroups.ReadFile(path, cgroupCpuacctStat)
 	if err != nil {
 		return 0, 0, err
 	}
@@ -116,7 +116,7 @@ func getCpuUsageBreakdown(path string) (uint64, uint64, error) {
 
 func getPercpuUsage(path string) ([]uint64, error) {
 	percpuUsage := []uint64{}
-	data, err := fscommon.ReadFile(path, "cpuacct.usage_percpu")
+	data, err := cgroups.ReadFile(path, "cpuacct.usage_percpu")
 	if err != nil {
 		return percpuUsage, err
 	}
@@ -134,7 +134,7 @@ func getPercpuUsageInModes(path string) ([]uint64, []uint64, error) {
 	usageKernelMode := []uint64{}
 	usageUserMode := []uint64{}
 
-	file, err := fscommon.OpenFile(path, cgroupCpuacctUsageAll, os.O_RDONLY)
+	file, err := cgroups.OpenFile(path, cgroupCpuacctUsageAll, os.O_RDONLY)
 	if os.IsNotExist(err) {
 		return usageKernelMode, usageUserMode, nil
 	} else if err != nil {

libcontainer/cgroups/fs/cpuset.go

@@ -28,12 +28,12 @@ func (s *CpusetGroup) Apply(path string, d *cgroupData) error {
 
 func (s *CpusetGroup) Set(path string, r *configs.Resources) error {
 	if r.CpusetCpus != "" {
-		if err := fscommon.WriteFile(path, "cpuset.cpus", r.CpusetCpus); err != nil {
+		if err := cgroups.WriteFile(path, "cpuset.cpus", r.CpusetCpus); err != nil {
 			return err
 		}
 	}
 	if r.CpusetMems != "" {
-		if err := fscommon.WriteFile(path, "cpuset.mems", r.CpusetMems); err != nil {
+		if err := cgroups.WriteFile(path, "cpuset.mems", r.CpusetMems); err != nil {
 			return err
 		}
 	}
@@ -175,10 +175,10 @@ func (s *CpusetGroup) ApplyDir(dir string, r *configs.Resources, pid int) error
 }
 
 func getCpusetSubsystemSettings(parent string) (cpus, mems string, err error) {
-	if cpus, err = fscommon.ReadFile(parent, "cpuset.cpus"); err != nil {
+	if cpus, err = cgroups.ReadFile(parent, "cpuset.cpus"); err != nil {
 		return
 	}
-	if mems, err = fscommon.ReadFile(parent, "cpuset.mems"); err != nil {
+	if mems, err = cgroups.ReadFile(parent, "cpuset.mems"); err != nil {
 		return
 	}
 	return cpus, mems, nil
@@ -224,12 +224,12 @@ func cpusetCopyIfNeeded(current, parent string) error {
 	}
 
 	if isEmptyCpuset(currentCpus) {
-		if err := fscommon.WriteFile(current, "cpuset.cpus", string(parentCpus)); err != nil {
+		if err := cgroups.WriteFile(current, "cpuset.cpus", string(parentCpus)); err != nil {
 			return err
 		}
 	}
 	if isEmptyCpuset(currentMems) {
-		if err := fscommon.WriteFile(current, "cpuset.mems", string(parentMems)); err != nil {
+		if err := cgroups.WriteFile(current, "cpuset.mems", string(parentMems)); err != nil {
 			return err
 		}
 	}

libcontainer/cgroups/fs/devices.go

@@ -9,7 +9,6 @@ import (
 
 	"github.com/opencontainers/runc/libcontainer/cgroups"
 	cgroupdevices "github.com/opencontainers/runc/libcontainer/cgroups/devices"
-	"github.com/opencontainers/runc/libcontainer/cgroups/fscommon"
 	"github.com/opencontainers/runc/libcontainer/configs"
 	"github.com/opencontainers/runc/libcontainer/devices"
 	"github.com/opencontainers/runc/libcontainer/userns"
@@ -36,7 +35,7 @@ func (s *DevicesGroup) Apply(path string, d *cgroupData) error {
 }
 
 func loadEmulator(path string) (*cgroupdevices.Emulator, error) {
-	list, err := fscommon.ReadFile(path, "devices.list")
+	list, err := cgroups.ReadFile(path, "devices.list")
 	if err != nil {
 		return nil, err
 	}
@@ -81,7 +80,7 @@ func (s *DevicesGroup) Set(path string, r *configs.Resources) error {
 		if rule.Allow {
 			file = "devices.allow"
 		}
-		if err := fscommon.WriteFile(path, file, rule.CgroupString()); err != nil {
+		if err := cgroups.WriteFile(path, file, rule.CgroupString()); err != nil {
 			return err
 		}
 	}

libcontainer/cgroups/fs/freezer.go

@@ -10,7 +10,6 @@ import (
 	"time"
 
 	"github.com/opencontainers/runc/libcontainer/cgroups"
-	"github.com/opencontainers/runc/libcontainer/cgroups/fscommon"
 	"github.com/opencontainers/runc/libcontainer/configs"
 	"github.com/sirupsen/logrus"
 	"golang.org/x/sys/unix"
@@ -34,7 +33,7 @@ func (s *FreezerGroup) Set(path string, r *configs.Resources) (Err error) {
 				// Freezing failed, and it is bad and dangerous
 				// to leave the cgroup in FROZEN or FREEZING
 				// state, so (try to) thaw it back.
-				_ = fscommon.WriteFile(path, "freezer.state", string(configs.Thawed))
+				_ = cgroups.WriteFile(path, "freezer.state", string(configs.Thawed))
 			}
 		}()
 
@@ -67,11 +66,11 @@ func (s *FreezerGroup) Set(path string, r *configs.Resources) (Err error) {
 				// the chances to succeed in freezing
 				// in case new processes keep appearing
 				// in the cgroup.
-				_ = fscommon.WriteFile(path, "freezer.state", string(configs.Thawed))
+				_ = cgroups.WriteFile(path, "freezer.state", string(configs.Thawed))
 				time.Sleep(10 * time.Millisecond)
 			}
 
-			if err := fscommon.WriteFile(path, "freezer.state", string(configs.Frozen)); err != nil {
+			if err := cgroups.WriteFile(path, "freezer.state", string(configs.Frozen)); err != nil {
 				return err
 			}
 
@@ -82,7 +81,7 @@ func (s *FreezerGroup) Set(path string, r *configs.Resources) (Err error) {
 				// system.
 				time.Sleep(10 * time.Microsecond)
 			}
-			state, err := fscommon.ReadFile(path, "freezer.state")
+			state, err := cgroups.ReadFile(path, "freezer.state")
 			if err != nil {
 				return err
 			}
@@ -103,7 +102,7 @@ func (s *FreezerGroup) Set(path string, r *configs.Resources) (Err error) {
 		// Despite our best efforts, it got stuck in FREEZING.
 		return errors.New("unable to freeze")
 	case configs.Thawed:
-		return fscommon.WriteFile(path, "freezer.state", string(configs.Thawed))
+		return cgroups.WriteFile(path, "freezer.state", string(configs.Thawed))
 	case configs.Undefined:
 		return nil
 	default:
@@ -117,7 +116,7 @@ func (s *FreezerGroup) GetStats(path string, stats *cgroups.Stats) error {
 
 func (s *FreezerGroup) GetState(path string) (configs.FreezerState, error) {
 	for {
-		state, err := fscommon.ReadFile(path, "freezer.state")
+		state, err := cgroups.ReadFile(path, "freezer.state")
 		if err != nil {
 			// If the kernel is too old, then we just treat the freezer as
 			// being in an "undefined" state.

libcontainer/cgroups/fs/fs_test.go

@@ -8,7 +8,6 @@ import (
 	"testing"
 
 	"github.com/opencontainers/runc/libcontainer/cgroups"
-	"github.com/opencontainers/runc/libcontainer/cgroups/fscommon"
 	"github.com/opencontainers/runc/libcontainer/configs"
 )
 
@@ -113,9 +112,9 @@ func BenchmarkGetStats(b *testing.B) {
 
 	// Unset TestMode as we work with real cgroupfs here,
 	// and we want OpenFile to perform the fstype check.
-	fscommon.TestMode = false
+	cgroups.TestMode = false
 	defer func() {
-		fscommon.TestMode = true
+		cgroups.TestMode = true
 	}()
 
 	cg := &configs.Cgroup{

libcontainer/cgroups/fs/hugetlb.go

@@ -23,7 +23,7 @@ func (s *HugetlbGroup) Apply(path string, d *cgroupData) error {
 
 func (s *HugetlbGroup) Set(path string, r *configs.Resources) error {
 	for _, hugetlb := range r.HugetlbLimit {
-		if err := fscommon.WriteFile(path, "hugetlb."+hugetlb.Pagesize+".limit_in_bytes", strconv.FormatUint(hugetlb.Limit, 10)); err != nil {
+		if err := cgroups.WriteFile(path, "hugetlb."+hugetlb.Pagesize+".limit_in_bytes", strconv.FormatUint(hugetlb.Limit, 10)); err != nil {
 			return err
 		}
 	}