1 files changed, 413 insertions, 0 deletions
diff --git a/src/kube2msb/vendor/github.com/opencontainers/runc/libcontainer/cgroups/utils.go b/src/kube2msb/vendor/github.com/opencontainers/runc/libcontainer/cgroups/utils.go
new file mode 100644
index 0000000..1a7c4e1
--- /dev/null
+++ b/src/kube2msb/vendor/github.com/opencontainers/runc/libcontainer/cgroups/utils.go
@@ -0,0 +1,413 @@
+// +build linux
+
+package cgroups
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/docker/go-units"
+)
+
+const cgroupNamePrefix = "name="
+
+// https://www.kernel.org/doc/Documentation/cgroup-v1/cgroups.txt
+func FindCgroupMountpoint(subsystem string) (string, error) {
+	// We are not using mount.GetMounts() because it's super-inefficient,
+	// parsing it directly sped up x10 times because of not using Sscanf.
+	// It was one of two major performance drawbacks in container start.
+	if !isSubsystemAvailable(subsystem) {
+		return "", NewNotFoundError(subsystem)
+	}
+	f, err := os.Open("/proc/self/mountinfo")
+	if err != nil {
+		return "", err
+	}
+	defer f.Close()
+
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		txt := scanner.Text()
+		fields := strings.Split(txt, " ")
+		for _, opt := range strings.Split(fields[len(fields)-1], ",") {
+			if opt == subsystem {
+				return fields[4], nil
+			}
+		}
+	}
+	if err := scanner.Err(); err != nil {
+		return "", err
+	}
+
+	return "", NewNotFoundError(subsystem)
+}
+
+func FindCgroupMountpointAndRoot(subsystem string) (string, string, error) {
+	if !isSubsystemAvailable(subsystem) {
+		return "", "", NewNotFoundError(subsystem)
+	}
+	f, err := os.Open("/proc/self/mountinfo")
+	if err != nil {
+		return "", "", err
+	}
+	defer f.Close()
+
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		txt := scanner.Text()
+		fields := strings.Split(txt, " ")
+		for _, opt := range strings.Split(fields[len(fields)-1], ",") {
+			if opt == subsystem {
+				return fields[4], fields[3], nil
+			}
+		}
+	}
+	if err := scanner.Err(); err != nil {
+		return "", "", err
+	}
+
+	return "", "", NewNotFoundError(subsystem)
+}
+
+func isSubsystemAvailable(subsystem string) bool {
+	cgroups, err := ParseCgroupFile("/proc/self/cgroup")
+	if err != nil {
+		return false
+	}
+	_, avail := cgroups[subsystem]
+	return avail
+}
+
+func FindCgroupMountpointDir() (string, error) {
+	f, err := os.Open("/proc/self/mountinfo")
+	if err != nil {
+		return "", err
+	}
+	defer f.Close()
+
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		text := scanner.Text()
+		fields := strings.Split(text, " ")
+		// Safe as mountinfo encodes mountpoints with spaces as \040.
+		index := strings.Index(text, " - ")
+		postSeparatorFields := strings.Fields(text[index+3:])
+		numPostFields := len(postSeparatorFields)
+
+		// This is an error as we can't detect if the mount is for "cgroup"
+		if numPostFields == 0 {
+			return "", fmt.Errorf("Found no fields post '-' in %q", text)
+		}
+
+		if postSeparatorFields[0] == "cgroup" {
+			// Check that the mount is properly formated.
+			if numPostFields < 3 {
+				return "", fmt.Errorf("Error found less than 3 fields post '-' in %q", text)
+			}
+
+			return filepath.Dir(fields[4]), nil
+		}
+	}
+	if err := scanner.Err(); err != nil {
+		return "", err
+	}
+
+	return "", NewNotFoundError("cgroup")
+}
+
+type Mount struct {
+	Mountpoint string
+	Root       string
+	Subsystems []string
+}
+
+func (m Mount) GetThisCgroupDir(cgroups map[string]string) (string, error) {
+	if len(m.Subsystems) == 0 {
+		return "", fmt.Errorf("no subsystem for mount")
+	}
+
+	return getControllerPath(m.Subsystems[0], cgroups)
+}
+
+func getCgroupMountsHelper(ss map[string]bool, mi io.Reader) ([]Mount, error) {
+	res := make([]Mount, 0, len(ss))
+	scanner := bufio.NewScanner(mi)
+	numFound := 0
+	for scanner.Scan() && numFound < len(ss) {
+		txt := scanner.Text()
+		sepIdx := strings.Index(txt, " - ")
+		if sepIdx == -1 {
+			return nil, fmt.Errorf("invalid mountinfo format")
+		}
+		if txt[sepIdx+3:sepIdx+9] != "cgroup" {
+			continue
+		}
+		fields := strings.Split(txt, " ")
+		m := Mount{
+			Mountpoint: fields[4],
+			Root:       fields[3],
+		}
+		for _, opt := range strings.Split(fields[len(fields)-1], ",") {
+			if !ss[opt] {
+				continue
+			}
+			if strings.HasPrefix(opt, cgroupNamePrefix) {
+				m.Subsystems = append(m.Subsystems, opt[len(cgroupNamePrefix):])
+			} else {
+				m.Subsystems = append(m.Subsystems, opt)
+			}
+			numFound++
+		}
+		res = append(res, m)
+	}
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+	return res, nil
+}
+
+func GetCgroupMounts() ([]Mount, error) {
+	f, err := os.Open("/proc/self/mountinfo")
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	all, err := ParseCgroupFile("/proc/self/cgroup")
+	if err != nil {
+		return nil, err
+	}
+
+	allMap := make(map[string]bool)
+	for s := range all {
+		allMap[s] = true
+	}
+	return getCgroupMountsHelper(allMap, f)
+}
+
+// GetAllSubsystems returns all the cgroup subsystems supported by the kernel
+func GetAllSubsystems() ([]string, error) {
+	f, err := os.Open("/proc/cgroups")
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	subsystems := []string{}
+
+	s := bufio.NewScanner(f)
+	for s.Scan() {
+		if err := s.Err(); err != nil {
+			return nil, err
+		}
+		text := s.Text()
+		if text[0] != '#' {
+			parts := strings.Fields(text)
+			if len(parts) >= 4 && parts[3] != "0" {
+				subsystems = append(subsystems, parts[0])
+			}
+		}
+	}
+	return subsystems, nil
+}
+
+// GetThisCgroupDir returns the relative path to the cgroup docker is running in.
+func GetThisCgroupDir(subsystem string) (string, error) {
+	cgroups, err := ParseCgroupFile("/proc/self/cgroup")
+	if err != nil {
+		return "", err
+	}
+
+	return getControllerPath(subsystem, cgroups)
+}
+
+func GetInitCgroupDir(subsystem string) (string, error) {
+
+	cgroups, err := ParseCgroupFile("/proc/1/cgroup")
+	if err != nil {
+		return "", err
+	}
+
+	return getControllerPath(subsystem, cgroups)
+}
+
+func readProcsFile(dir string) ([]int, error) {
+	f, err := os.Open(filepath.Join(dir, "cgroup.procs"))
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	var (
+		s   = bufio.NewScanner(f)
+		out = []int{}
+	)
+
+	for s.Scan() {
+		if t := s.Text(); t != "" {
+			pid, err := strconv.Atoi(t)
+			if err != nil {
+				return nil, err
+			}
+			out = append(out, pid)
+		}
+	}
+	return out, nil
+}
+
+// ParseCgroupFile parses the given cgroup file, typically from
+// /proc/<pid>/cgroup, into a map of subgroups to cgroup names.
+func ParseCgroupFile(path string) (map[string]string, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	return parseCgroupFromReader(f)
+}
+
+// helper function for ParseCgroupFile to make testing easier
+func parseCgroupFromReader(r io.Reader) (map[string]string, error) {
+	s := bufio.NewScanner(r)
+	cgroups := make(map[string]string)
+
+	for s.Scan() {
+		if err := s.Err(); err != nil {
+			return nil, err
+		}
+
+		text := s.Text()
+		// from cgroups(7):
+		// /proc/[pid]/cgroup
+		// ...
+		// For each cgroup hierarchy ... there is one entry
+		// containing three colon-separated fields of the form:
+		//     hierarchy-ID:subsystem-list:cgroup-path
+		parts := strings.SplitN(text, ":", 3)
+		if len(parts) < 3 {
+			return nil, fmt.Errorf("invalid cgroup entry: must contain at least two colons: %v", text)
+		}
+
+		for _, subs := range strings.Split(parts[1], ",") {
+			cgroups[subs] = parts[2]
+		}
+	}
+	return cgroups, nil
+}
+
+func getControllerPath(subsystem string, cgroups map[string]string) (string, error) {
+
+	if p, ok := cgroups[subsystem]; ok {
+		return p, nil
+	}
+
+	if p, ok := cgroups[cgroupNamePrefix+subsystem]; ok {
+		return p, nil
+	}
+
+	return "", NewNotFoundError(subsystem)
+}
+
+func PathExists(path string) bool {
+	if _, err := os.Stat(path); err != nil {
+		return false
+	}
+	return true
+}
+
+func EnterPid(cgroupPaths map[string]string, pid int) error {
+	for _, path := range cgroupPaths {
+		if PathExists(path) {
+			if err := ioutil.WriteFile(filepath.Join(path, "cgroup.procs"),
+				[]byte(strconv.Itoa(pid)), 0700); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+// RemovePaths iterates over the provided paths removing them.
+// We trying to remove all paths five times with increasing delay between tries.
+// If after all there are not removed cgroups - appropriate error will be
+// returned.
+func RemovePaths(paths map[string]string) (err error) {
+	delay := 10 * time.Millisecond
+	for i := 0; i < 5; i++ {
+		if i != 0 {
+			time.Sleep(delay)
+			delay *= 2
+		}
+		for s, p := range paths {
+			os.RemoveAll(p)
+			// TODO: here probably should be logging
+			_, err := os.Stat(p)
+			// We need this strange way of checking cgroups existence because
+			// RemoveAll almost always returns error, even on already removed
+			// cgroups
+			if os.IsNotExist(err) {
+				delete(paths, s)
+			}
+		}
+		if len(paths) == 0 {
+			return nil
+		}
+	}
+	return fmt.Errorf("Failed to remove paths: %v", paths)
+}
+
+func GetHugePageSize() ([]string, error) {
+	var pageSizes []string
+	sizeList := []string{"B", "kB", "MB", "GB", "TB", "PB"}
+	files, err := ioutil.ReadDir("/sys/kernel/mm/hugepages")
+	if err != nil {
+		return pageSizes, err
+	}
+	for _, st := range files {
+		nameArray := strings.Split(st.Name(), "-")
+		pageSize, err := units.RAMInBytes(nameArray[1])
+		if err != nil {
+			return []string{}, err
+		}
+		sizeString := units.CustomSize("%g%s", float64(pageSize), 1024.0, sizeList)
+		pageSizes = append(pageSizes, sizeString)
+	}
+
+	return pageSizes, nil
+}
+
+// GetPids returns all pids, that were added to cgroup at path.
+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 {
+		dir, file := filepath.Split(p)
+		if file != "cgroup.procs" {
+			return nil
+		}
+		if iErr != nil {
+			return iErr
+		}
+		cPids, err := readProcsFile(dir)
+		if err != nil {
+			return err
+		}
+		pids = append(pids, cPids...)
+		return nil
+	})
+	return pids, err
+}