opensource/podman
1
0
Fork 0
mirror of https://github.com/containers/podman.git synced 2025-05-21 00:56:36 +08:00
Code Issues Packages Projects Releases Wiki Activity

podman, exec: move conmon to the correct cgroup

Browse Source 
move the conmon process to the conmon cgroup also on exec.

The previous implementation would fail to move the conmon process as
the systemd unit already exists so its creation would fail.

When the unit cannot be created, attempt to directly join the cgroup
instead.

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
This commit is contained in:
Giuseppe Scrivano
2020-12-02 22:07:55 +01:00
parent 9c5fe954cc
commit 9a33e064a1
1 changed files with 36 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

43
utils/utils_supported.go
View File

@ -43,6 +43,15 @@ func RunUnderSystemdScope(pid int, slice string, unitName string) error {
ch := make(chan string)
_, err = conn.StartTransientUnit(unitName, "replace", properties, ch)
if err != nil {
// On errors check if the cgroup already exists, if it does move the process there
if props, err := conn.GetUnitTypeProperties(unitName, "Scope"); err == nil {
if cgroup, ok := props["ControlGroup"].(string); ok && cgroup != "" {
if err := moveUnderCgroup(cgroup, "", []uint32{uint32(pid)}); err != nil {
return err
}
return nil
}
}
return err
}
defer conn.Close()
@ -101,6 +110,13 @@ func GetCgroupProcess(pid int) (string, error) {
// MoveUnderCgroupSubtree moves the PID under a cgroup subtree.
func MoveUnderCgroupSubtree(subtree string) error {
return moveUnderCgroup("", subtree, nil)
}
// moveUnderCgroup moves a group of processes to a new cgroup.
// If cgroup is the empty string, then the current calling process cgroup is used.
// If processes is empty, then the processes from the current cgroup are moved.
func moveUnderCgroup(cgroup, subtree string, processes []uint32) error {
procFile := "/proc/self/cgroup"
f, err := os.Open(procFile)
if err != nil {
@ -140,13 +156,12 @@ func MoveUnderCgroupSubtree(subtree string) error {
cgroupRoot = filepath.Join(cgroupRoot, controller)
}
processes, err := ioutil.ReadFile(filepath.Join(cgroupRoot, parts[2], "cgroup.procs"))
if err != nil {
return err
parentCgroup := cgroup
if parentCgroup == "" {
parentCgroup = parts[2]
}
newCgroup := filepath.Join(cgroupRoot, parts[2], subtree)
if err := os.Mkdir(newCgroup, 0755); err != nil {
newCgroup := filepath.Join(cgroupRoot, parentCgroup, subtree)
if err := os.Mkdir(newCgroup, 0755); err != nil && !os.IsExist(err) {
return err
}
@ -156,9 +171,21 @@ func MoveUnderCgroupSubtree(subtree string) error {
}
defer f.Close()
for _, pid := range bytes.Split(processes, []byte("\n")) {
if len(processes) > 0 {
for _, pid := range processes {
if _, err := f.Write([]byte(fmt.Sprintf("%d\n", pid))); err != nil {
logrus.Warnf("Cannot move process %d to cgroup %q", pid, newCgroup)
}
}
} else {
processesData, err := ioutil.ReadFile(filepath.Join(cgroupRoot, parts[2], "cgroup.procs"))
if err != nil {
return err
}
for _, pid := range bytes.Split(processesData, []byte("\n")) {
if _, err := f.Write(pid); err != nil {
logrus.Warnf("Cannot move process %s to cgroup %q", pid, newCgroup)
logrus.Warnf("Cannot move process %d to cgroup %q", pid, newCgroup)
}
}
}
}