147 lines
3 KiB
Go
147 lines
3 KiB
Go
package fs
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import (
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"fmt"
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"io/ioutil"
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"os"
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"path/filepath"
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"strconv"
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"github.com/dotcloud/docker/pkg/cgroups"
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)
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var (
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subsystems = map[string]subsystem{
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"devices": &devicesGroup{},
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"memory": &memoryGroup{},
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"cpu": &cpuGroup{},
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"cpuset": &cpusetGroup{},
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"cpuacct": &cpuacctGroup{},
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"blkio": &blkioGroup{},
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"perf_event": &perfEventGroup{},
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"freezer": &freezerGroup{},
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}
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)
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type subsystem interface {
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Set(*data) error
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Remove(*data) error
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Stats(*data) (map[string]float64, error)
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}
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type data struct {
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root string
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cgroup string
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c *cgroups.Cgroup
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pid int
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}
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func Apply(c *cgroups.Cgroup, pid int) (cgroups.ActiveCgroup, error) {
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// We have two implementation of cgroups support, one is based on
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// systemd and the dbus api, and one is based on raw cgroup fs operations
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// following the pre-single-writer model docs at:
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// http://www.freedesktop.org/wiki/Software/systemd/PaxControlGroups/
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//
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// we can pick any subsystem to find the root
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cgroupRoot, err := cgroups.FindCgroupMountpoint("cpu")
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if err != nil {
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return nil, err
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}
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cgroupRoot = filepath.Dir(cgroupRoot)
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if _, err := os.Stat(cgroupRoot); err != nil {
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return nil, fmt.Errorf("cgroups fs not found")
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}
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cgroup := c.Name
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if c.Parent != "" {
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cgroup = filepath.Join(c.Parent, cgroup)
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}
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d := &data{
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root: cgroupRoot,
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cgroup: cgroup,
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c: c,
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pid: pid,
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}
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for _, sys := range subsystems {
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if err := sys.Set(d); err != nil {
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d.Cleanup()
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return nil, err
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}
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}
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return d, nil
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}
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func GetStats(c *cgroups.Cgroup, subsystem string, pid int) (map[string]float64, error) {
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cgroupRoot, err := cgroups.FindCgroupMountpoint("cpu")
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if err != nil {
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return nil, err
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}
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cgroupRoot = filepath.Dir(cgroupRoot)
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if _, err := os.Stat(cgroupRoot); err != nil {
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return nil, fmt.Errorf("cgroups fs not found")
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}
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cgroup := c.Name
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if c.Parent != "" {
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cgroup = filepath.Join(c.Parent, cgroup)
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}
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d := &data{
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root: cgroupRoot,
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cgroup: cgroup,
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c: c,
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pid: pid,
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}
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sys, exists := subsystems[subsystem]
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if !exists {
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return nil, fmt.Errorf("subsystem %s does not exist", subsystem)
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}
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return sys.Stats(d)
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}
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func (raw *data) path(subsystem string) (string, error) {
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initPath, err := cgroups.GetInitCgroupDir(subsystem)
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if err != nil {
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return "", err
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}
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return filepath.Join(raw.root, subsystem, initPath, raw.cgroup), nil
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}
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func (raw *data) join(subsystem string) (string, error) {
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path, err := raw.path(subsystem)
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if err != nil {
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return "", err
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}
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if err := os.MkdirAll(path, 0755); err != nil && !os.IsExist(err) {
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return "", err
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}
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if err := writeFile(path, "cgroup.procs", strconv.Itoa(raw.pid)); err != nil {
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return "", err
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}
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return path, nil
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}
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func (raw *data) Cleanup() error {
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for _, sys := range subsystems {
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sys.Remove(raw)
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}
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return nil
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}
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func writeFile(dir, file, data string) error {
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return ioutil.WriteFile(filepath.Join(dir, file), []byte(data), 0700)
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}
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func removePath(p string, err error) error {
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if err != nil {
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return err
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}
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if p != "" {
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return os.RemoveAll(p)
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}
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return nil
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}
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