diff options
Diffstat (limited to 'vendor/github.com/opencontainers/runc/libcontainer/cgroups/utils.go')
| -rw-r--r-- | vendor/github.com/opencontainers/runc/libcontainer/cgroups/utils.go | 357 |
1 files changed, 74 insertions, 283 deletions
diff --git a/vendor/github.com/opencontainers/runc/libcontainer/cgroups/utils.go b/vendor/github.com/opencontainers/runc/libcontainer/cgroups/utils.go index dbcc58f5b..6e88b5dff 100644 --- a/vendor/github.com/opencontainers/runc/libcontainer/cgroups/utils.go +++ b/vendor/github.com/opencontainers/runc/libcontainer/cgroups/utils.go @@ -4,6 +4,7 @@ package cgroups import ( "bufio" + "errors" "fmt" "io" "io/ioutil" @@ -12,7 +13,6 @@ import ( "strconv" "strings" "sync" - "syscall" "time" units "github.com/docker/go-units" @@ -20,7 +20,6 @@ import ( ) const ( - CgroupNamePrefix = "name=" CgroupProcesses = "cgroup.procs" unifiedMountpoint = "/sys/fs/cgroup" ) @@ -40,8 +39,8 @@ var HugePageSizeUnitList = []string{"B", "KB", "MB", "GB", "TB", "PB"} // IsCgroup2UnifiedMode returns whether we are running in cgroup v2 unified mode. func IsCgroup2UnifiedMode() bool { isUnifiedOnce.Do(func() { - var st syscall.Statfs_t - if err := syscall.Statfs(unifiedMountpoint, &st); err != nil { + var st unix.Statfs_t + if err := unix.Statfs(unifiedMountpoint, &st); err != nil { panic("cannot statfs cgroup root") } isUnified = st.Type == unix.CGROUP2_SUPER_MAGIC @@ -49,191 +48,19 @@ func IsCgroup2UnifiedMode() bool { return isUnified } -// https://www.kernel.org/doc/Documentation/cgroup-v1/cgroups.txt -func FindCgroupMountpoint(cgroupPath, subsystem string) (string, error) { - if IsCgroup2UnifiedMode() { - return unifiedMountpoint, nil - } - mnt, _, err := FindCgroupMountpointAndRoot(cgroupPath, subsystem) - return mnt, err -} - -func FindCgroupMountpointAndRoot(cgroupPath, subsystem string) (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() - - if IsCgroup2UnifiedMode() { - subsystem = "" - } - - return findCgroupMountpointAndRootFromReader(f, cgroupPath, subsystem) -} - -func findCgroupMountpointAndRootFromReader(reader io.Reader, cgroupPath, subsystem string) (string, string, error) { - scanner := bufio.NewScanner(reader) - for scanner.Scan() { - txt := scanner.Text() - fields := strings.Fields(txt) - if len(fields) < 9 { - continue - } - if strings.HasPrefix(fields[4], cgroupPath) { - for _, opt := range strings.Split(fields[len(fields)-1], ",") { - if (subsystem == "" && fields[9] == "cgroup2") || opt == subsystem { - return fields[4], fields[3], nil - } - } - } - } - if err := scanner.Err(); err != nil { - return "", "", err - } - - return "", "", NewNotFoundError(subsystem) -} - -func isSubsystemAvailable(subsystem string) bool { - if IsCgroup2UnifiedMode() { - controllers, err := GetAllSubsystems() - if err != nil { - return false - } - for _, c := range controllers { - if c == subsystem { - return true - } - } - return false - } - - cgroups, err := ParseCgroupFile("/proc/self/cgroup") - if err != nil { - return false - } - _, avail := cgroups[subsystem] - return avail -} - -func GetClosestMountpointAncestor(dir, mountinfo string) string { - deepestMountPoint := "" - for _, mountInfoEntry := range strings.Split(mountinfo, "\n") { - mountInfoParts := strings.Fields(mountInfoEntry) - if len(mountInfoParts) < 5 { - continue - } - mountPoint := mountInfoParts[4] - if strings.HasPrefix(mountPoint, deepestMountPoint) && strings.HasPrefix(dir, mountPoint) { - deepestMountPoint = mountPoint - } - } - return deepestMountPoint -} - -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" || postSeparatorFields[0] == "cgroup2" { - // Check that the mount is properly formatted. - 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) GetOwnCgroup(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, all bool) ([]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+10] == "cgroup2" || 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], ",") { - seen, known := ss[opt] - if !known || (!all && seen) { - continue - } - ss[opt] = true - if strings.HasPrefix(opt, CgroupNamePrefix) { - opt = opt[len(CgroupNamePrefix):] - } - m.Subsystems = append(m.Subsystems, opt) - numFound++ - } - if len(m.Subsystems) > 0 || all { - res = append(res, m) - } - } - if err := scanner.Err(); err != nil { - return nil, err - } - return res, nil -} - // GetCgroupMounts returns the mounts for the cgroup subsystems. // all indicates whether to return just the first instance or all the mounts. +// This function should not be used from cgroupv2 code, as in this case +// all the controllers are available under the constant unifiedMountpoint. func GetCgroupMounts(all bool) ([]Mount, error) { if IsCgroup2UnifiedMode() { + // TODO: remove cgroupv2 case once all external users are converted availableControllers, err := GetAllSubsystems() if err != nil { return nil, err @@ -246,22 +73,7 @@ func GetCgroupMounts(all bool) ([]Mount, error) { return []Mount{m}, nil } - f, err := os.Open("/proc/self/mountinfo") - if err != nil { - return nil, err - } - defer f.Close() - - allSubsystems, err := ParseCgroupFile("/proc/self/cgroup") - if err != nil { - return nil, err - } - - allMap := make(map[string]bool) - for s := range allSubsystems { - allMap[s] = false - } - return getCgroupMountsHelper(allMap, f, all) + return getCgroupMountsV1(all) } // GetAllSubsystems returns all the cgroup subsystems supported by the kernel @@ -305,61 +117,8 @@ func GetAllSubsystems() ([]string, error) { return subsystems, nil } -// GetOwnCgroup returns the relative path to the cgroup docker is running in. -func GetOwnCgroup(subsystem string) (string, error) { - cgroups, err := ParseCgroupFile("/proc/self/cgroup") - if err != nil { - return "", err - } - - return getControllerPath(subsystem, cgroups) -} - -func GetOwnCgroupPath(subsystem string) (string, error) { - cgroup, err := GetOwnCgroup(subsystem) - if err != nil { - return "", err - } - - return getCgroupPathHelper(subsystem, cgroup) -} - -func GetInitCgroup(subsystem string) (string, error) { - cgroups, err := ParseCgroupFile("/proc/1/cgroup") - if err != nil { - return "", err - } - - return getControllerPath(subsystem, cgroups) -} - -func GetInitCgroupPath(subsystem string) (string, error) { - cgroup, err := GetInitCgroup(subsystem) - if err != nil { - return "", err - } - - return getCgroupPathHelper(subsystem, cgroup) -} - -func getCgroupPathHelper(subsystem, cgroup string) (string, error) { - mnt, root, err := FindCgroupMountpointAndRoot("", subsystem) - if err != nil { - return "", err - } - - // This is needed for nested containers, because in /proc/self/cgroup we - // see paths from host, which don't exist in container. - relCgroup, err := filepath.Rel(root, cgroup) - if err != nil { - return "", err - } - - return filepath.Join(mnt, relCgroup), nil -} - -func readProcsFile(dir string) ([]int, error) { - f, err := os.Open(filepath.Join(dir, CgroupProcesses)) +func readProcsFile(file string) ([]int, error) { + f, err := os.Open(file) if err != nil { return nil, err } @@ -379,11 +138,18 @@ func readProcsFile(dir string) ([]int, error) { out = append(out, pid) } } - return out, nil + return out, s.Err() } -// ParseCgroupFile parses the given cgroup file, typically from -// /proc/<pid>/cgroup, into a map of subgroups to cgroup names. +// ParseCgroupFile parses the given cgroup file, typically /proc/self/cgroup +// or /proc/<pid>/cgroup, into a map of subsystems to cgroup paths, e.g. +// "cpu": "/user.slice/user-1000.slice" +// "pids": "/user.slice/user-1000.slice" +// etc. +// +// Note that for cgroup v2 unified hierarchy, there are no per-controller +// cgroup paths, so the resulting map will have a single element where the key +// is empty string ("") and the value is the cgroup path the <pid> is in. func ParseCgroupFile(path string) (map[string]string, error) { f, err := os.Open(path) if err != nil { @@ -423,22 +189,6 @@ func parseCgroupFromReader(r io.Reader) (map[string]string, error) { return cgroups, nil } -func getControllerPath(subsystem string, cgroups map[string]string) (string, error) { - if IsCgroup2UnifiedMode() { - return "/", nil - } - - 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 @@ -514,8 +264,8 @@ func getHugePageSizeFromFilenames(fileNames []string) ([]string, error) { } // GetPids returns all pids, that were added to cgroup at path. -func GetPids(path string) ([]int, error) { - return readProcsFile(path) +func GetPids(dir string) ([]int, error) { + return readProcsFile(filepath.Join(dir, CgroupProcesses)) } // GetAllPids returns all pids, that were added to cgroup at path and to all its @@ -524,14 +274,13 @@ 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 != CgroupProcesses { - return nil - } if iErr != nil { return iErr } - cPids, err := readProcsFile(dir) + if info.IsDir() || info.Name() != CgroupProcesses { + return nil + } + cPids, err := readProcsFile(p) if err != nil { return err } @@ -568,7 +317,7 @@ func WriteCgroupProc(dir string, pid int) error { // EINVAL might mean that the task being added to cgroup.procs is in state // TASK_NEW. We should attempt to do so again. - if isEINVAL(err) { + if errors.Is(err, unix.EINVAL) { time.Sleep(30 * time.Millisecond) continue } @@ -578,11 +327,53 @@ func WriteCgroupProc(dir string, pid int) error { return err } -func isEINVAL(err error) bool { - switch err := err.(type) { - case *os.PathError: - return err.Err == unix.EINVAL - default: - return false +// Since the OCI spec is designed for cgroup v1, in some cases +// there is need to convert from the cgroup v1 configuration to cgroup v2 +// the formula for BlkIOWeight is y = (1 + (x - 10) * 9999 / 990) +// convert linearly from [10-1000] to [1-10000] +func ConvertBlkIOToCgroupV2Value(blkIoWeight uint16) uint64 { + if blkIoWeight == 0 { + return 0 + } + return uint64(1 + (uint64(blkIoWeight)-10)*9999/990) +} + +// Since the OCI spec is designed for cgroup v1, in some cases +// there is need to convert from the cgroup v1 configuration to cgroup v2 +// the formula for cpuShares is y = (1 + ((x - 2) * 9999) / 262142) +// convert from [2-262144] to [1-10000] +// 262144 comes from Linux kernel definition "#define MAX_SHARES (1UL << 18)" +func ConvertCPUSharesToCgroupV2Value(cpuShares uint64) uint64 { + if cpuShares == 0 { + return 0 } + return (1 + ((cpuShares-2)*9999)/262142) +} + +// ConvertMemorySwapToCgroupV2Value converts MemorySwap value from OCI spec +// for use by cgroup v2 drivers. A conversion is needed since Resources.MemorySwap +// is defined as memory+swap combined, while in cgroup v2 swap is a separate value. +func ConvertMemorySwapToCgroupV2Value(memorySwap, memory int64) (int64, error) { + // for compatibility with cgroup1 controller, set swap to unlimited in + // case the memory is set to unlimited, and swap is not explicitly set, + // treating the request as "set both memory and swap to unlimited". + if memory == -1 && memorySwap == 0 { + return -1, nil + } + if memorySwap == -1 || memorySwap == 0 { + // -1 is "max", 0 is "unset", so treat as is + return memorySwap, nil + } + // sanity checks + if memory == 0 || memory == -1 { + return 0, errors.New("unable to set swap limit without memory limit") + } + if memory < 0 { + return 0, fmt.Errorf("invalid memory value: %d", memory) + } + if memorySwap < memory { + return 0, errors.New("memory+swap limit should be >= memory limit") + } + + return memorySwap - memory, nil } |