Update vendor or containers/common moving pkg/cgroups there

[NO NEW TESTS NEEDED] This is just moving pkg/cgroups out so
existing tests should be fine.

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

vendor/github.com/containers/common/pkg/cgroups/cpuset.go

@@ -0,0 +1,85 @@
+package cgroups
+
+import (
+	"fmt"
+	"io/ioutil"
+	"path/filepath"
+	"strings"
+
+	spec "github.com/opencontainers/runtime-spec/specs-go"
+	"github.com/pkg/errors"
+)
+
+type cpusetHandler struct {
+}
+
+func cpusetCopyFileFromParent(dir, file string, cgroupv2 bool) ([]byte, error) {
+	if dir == cgroupRoot {
+		return nil, fmt.Errorf("could not find parent to initialize cpuset %s", file)
+	}
+	path := filepath.Join(dir, file)
+	parentPath := path
+	if cgroupv2 {
+		parentPath = fmt.Sprintf("%s.effective", parentPath)
+	}
+	data, err := ioutil.ReadFile(parentPath)
+	if err != nil {
+		return nil, errors.Wrapf(err, "open %s", path)
+	}
+	if strings.Trim(string(data), "\n") != "" {
+		return data, nil
+	}
+	data, err = cpusetCopyFileFromParent(filepath.Dir(dir), file, cgroupv2)
+	if err != nil {
+		return nil, err
+	}
+	if err := ioutil.WriteFile(path, data, 0644); err != nil {
+		return nil, errors.Wrapf(err, "write %s", path)
+	}
+	return data, nil
+}
+
+func cpusetCopyFromParent(path string, cgroupv2 bool) error {
+	for _, file := range []string{"cpuset.cpus", "cpuset.mems"} {
+		if _, err := cpusetCopyFileFromParent(path, file, cgroupv2); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func getCpusetHandler() *cpusetHandler {
+	return &cpusetHandler{}
+}
+
+// Apply set the specified constraints
+func (c *cpusetHandler) Apply(ctr *CgroupControl, res *spec.LinuxResources) error {
+	if res.CPU == nil {
+		return nil
+	}
+	return fmt.Errorf("cpuset apply not implemented yet")
+}
+
+// Create the cgroup
+func (c *cpusetHandler) Create(ctr *CgroupControl) (bool, error) {
+	if ctr.cgroup2 {
+		path := filepath.Join(cgroupRoot, ctr.path)
+		return true, cpusetCopyFromParent(path, true)
+	}
+
+	created, err := ctr.createCgroupDirectory(CPUset)
+	if !created || err != nil {
+		return created, err
+	}
+	return true, cpusetCopyFromParent(ctr.getCgroupv1Path(CPUset), false)
+}
+
+// Destroy the cgroup
+func (c *cpusetHandler) Destroy(ctr *CgroupControl) error {
+	return rmDirRecursively(ctr.getCgroupv1Path(CPUset))
+}
+
+// Stat fills a metrics structure with usage stats for the controller
+func (c *cpusetHandler) Stat(ctr *CgroupControl, m *Metrics) error {
+	return nil
+}