// checks if the required cgroups subsystems are mounted.
// As of now, only 'cpu' and 'memory' are required.
// cpu quota is a soft requirement.
func validateSystemRequirements(mountUtil mount.Interface) (features, error) {
const (
cgroupMountType = "cgroup"
localErr = "system validation failed"
)
var (
cpuMountPoint string
f features
)
mountPoints, err := mountUtil.List()
if err != nil {
return f, fmt.Errorf("%s - %v", localErr, err)
}
expectedCgroups := sets.NewString("cpu", "cpuacct", "cpuset", "memory")
for _, mountPoint := range mountPoints {
if mountPoint.Type == cgroupMountType {
for _, opt := range mountPoint.Opts {
if expectedCgroups.Has(opt) {
expectedCgroups.Delete(opt)
}
if opt == "cpu" {
cpuMountPoint = mountPoint.Path
}
}
}
}
if expectedCgroups.Len() > 0 {
return f, fmt.Errorf("%s - Following Cgroup subsystem not mounted: %v", localErr, expectedCgroups.List())
}
// Check if cpu quota is available.
// CPU cgroup is required and so it expected to be mounted at this point.
periodExists, err := util.FileExists(path.Join(cpuMountPoint, "cpu.cfs_period_us"))
if err != nil {
glog.Errorf("failed to detect if CPU cgroup cpu.cfs_period_us is available - %v", err)
}
quotaExists, err := util.FileExists(path.Join(cpuMountPoint, "cpu.cfs_quota_us"))
if err != nil {
glog.Errorf("failed to detect if CPU cgroup cpu.cfs_quota_us is available - %v", err)
}
if quotaExists && periodExists {
f.cpuHardcapping = true
}
return f, nil
}
// utility to mount a disk based filesystem
func diskSetUp(manager diskManager, b fcDiskMounter, volPath string, mounter mount.Interface, fsGroup *int64) error {
globalPDPath := manager.MakeGlobalPDName(*b.fcDisk)
// TODO: handle failed mounts here.
noMnt, err := mounter.IsLikelyNotMountPoint(volPath)
if err != nil && !os.IsNotExist(err) {
glog.Errorf("cannot validate mountpoint: %s", volPath)
return err
}
if !noMnt {
return nil
}
if err := manager.AttachDisk(b); err != nil {
glog.Errorf("failed to attach disk")
return err
}
if err := os.MkdirAll(volPath, 0750); err != nil {
glog.Errorf("failed to mkdir:%s", volPath)
return err
}
// Perform a bind mount to the full path to allow duplicate mounts of the same disk.
options := []string{"bind"}
if b.readOnly {
options = append(options, "ro")
}
err = mounter.Mount(globalPDPath, volPath, "", options)
if err != nil {
glog.Errorf("failed to bind mount:%s", globalPDPath)
return err
}
if !b.readOnly {
volume.SetVolumeOwnership(&b, fsGroup)
}
return nil
}
// utility to tear down a disk based filesystem
func diskTearDown(manager diskManager, c fcDiskUnmounter, volPath string, mounter mount.Interface) error {
noMnt, err := mounter.IsLikelyNotMountPoint(volPath)
if err != nil {
glog.Errorf("cannot validate mountpoint %s", volPath)
return err
}
if noMnt {
return os.Remove(volPath)
}
refs, err := mount.GetMountRefs(mounter, volPath)
if err != nil {
glog.Errorf("failed to get reference count %s", volPath)
return err
}
if err := mounter.Unmount(volPath); err != nil {
glog.Errorf("failed to unmount %s", volPath)
return err
}
// If len(refs) is 1, then all bind mounts have been removed, and the
// remaining reference is the global mount. It is safe to detach.
if len(refs) == 1 {
mntPath := refs[0]
if err := manager.DetachDisk(c, mntPath); err != nil {
glog.Errorf("failed to detach disk from %s", mntPath)
return err
}
}
noMnt, mntErr := mounter.IsLikelyNotMountPoint(volPath)
if mntErr != nil {
glog.Errorf("isMountpoint check failed: %v", mntErr)
return err
}
if noMnt {
if err := os.Remove(volPath); err != nil {
return err
}
}
return nil
}
// Unmount the global mount path, which should be the only one, and delete it.
func unmountPDAndRemoveGlobalPath(globalMountPath string, mounter mount.Interface) error {
err := mounter.Unmount(globalMountPath)
os.Remove(globalMountPath)
return err
}