Revert "Merge pull request 101888 from kolyshkin/update-runc-rc94"

This reverts commit b1b06fe0a4, reversing
changes made to 382a33986b.

vendor/github.com/opencontainers/runc/libcontainer/notify_linux_v2.go

@@ -3,28 +3,48 @@
 package libcontainer
 
 import (
+	"io/ioutil"
 	"path/filepath"
+	"strconv"
+	"strings"
 	"unsafe"
 
-	"github.com/opencontainers/runc/libcontainer/cgroups/fscommon"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 	"golang.org/x/sys/unix"
 )
 
+func getValueFromCgroup(path, key string) (int, error) {
+	content, err := ioutil.ReadFile(path)
+	if err != nil {
+		return 0, err
+	}
+
+	lines := strings.Split(string(content), "\n")
+	for _, line := range lines {
+		arr := strings.Split(line, " ")
+		if len(arr) == 2 && arr[0] == key {
+			return strconv.Atoi(arr[1])
+		}
+	}
+	return 0, nil
+}
+
 func registerMemoryEventV2(cgDir, evName, cgEvName string) (<-chan struct{}, error) {
+	eventControlPath := filepath.Join(cgDir, evName)
+	cgEvPath := filepath.Join(cgDir, cgEvName)
 	fd, err := unix.InotifyInit()
 	if err != nil {
 		return nil, errors.Wrap(err, "unable to init inotify")
 	}
 	// watching oom kill
-	evFd, err := unix.InotifyAddWatch(fd, filepath.Join(cgDir, evName), unix.IN_MODIFY)
+	evFd, err := unix.InotifyAddWatch(fd, eventControlPath, unix.IN_MODIFY)
 	if err != nil {
 		unix.Close(fd)
 		return nil, errors.Wrap(err, "unable to add inotify watch")
 	}
 	// Because no `unix.IN_DELETE|unix.IN_DELETE_SELF` event for cgroup file system, so watching all process exited
-	cgFd, err := unix.InotifyAddWatch(fd, filepath.Join(cgDir, cgEvName), unix.IN_MODIFY)
+	cgFd, err := unix.InotifyAddWatch(fd, cgEvPath, unix.IN_MODIFY)
 	if err != nil {
 		unix.Close(fd)
 		return nil, errors.Wrap(err, "unable to add inotify watch")
@@ -59,12 +79,12 @@ func registerMemoryEventV2(cgDir, evName, cgEvName string) (<-chan struct{}, err
 				}
 				switch int(rawEvent.Wd) {
 				case evFd:
-					oom, err := fscommon.GetValueByKey(cgDir, evName, "oom_kill")
+					oom, err := getValueFromCgroup(eventControlPath, "oom_kill")
 					if err != nil || oom > 0 {
 						ch <- struct{}{}
 					}
 				case cgFd:
-					pids, err := fscommon.GetValueByKey(cgDir, cgEvName, "populated")
+					pids, err := getValueFromCgroup(cgEvPath, "populated")
 					if err != nil || pids == 0 {
 						return
 					}