Update cgroups to e6d1aa8c71c6103624b2c6e6f4be0863

This bumps the cgroups package with various fixes to logging and net_cls
changes.

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

vendor/github.com/containerd/cgroups/net_cls.go

@@ -33,7 +33,7 @@ func (n *netclsController) Create(path string, resources *specs.LinuxResources)
 	}
 	if resources.Network != nil && resources.Network.ClassID != nil && *resources.Network.ClassID > 0 {
 		return ioutil.WriteFile(
-			filepath.Join(n.Path(path), "net_cls_classid_u"),
+			filepath.Join(n.Path(path), "net_cls.classid"),
 			[]byte(strconv.FormatUint(uint64(*resources.Network.ClassID), 10)),
 			defaultFilePerm,
 		)

vendor/github.com/containerd/cgroups/paths.go

@@ -3,6 +3,8 @@ package cgroups
 import (
 	"fmt"
 	"path/filepath"
+
+	"github.com/pkg/errors"
 )
 
 type Path func(subsystem Name) (string, error)
@@ -31,9 +33,10 @@ func NestedPath(suffix string) Path {
 // PidPath will return the correct cgroup paths for an existing process running inside a cgroup
 // This is commonly used for the Load function to restore an existing container
 func PidPath(pid int) Path {
-	paths, err := parseCgroupFile(fmt.Sprintf("/proc/%d/cgroup", pid))
+	p := fmt.Sprintf("/proc/%d/cgroup", pid)
+	paths, err := parseCgroupFile(p)
 	if err != nil {
-		return errorPath(err)
+		return errorPath(errors.Wrapf(err, "parse cgroup file %s", p))
 	}
 	return existingPath(paths, "")
 }

vendor/github.com/containerd/cgroups/utils.go

@@ -81,8 +81,8 @@ func defaults(root string) ([]Subsystem, error) {
 // remove will remove a cgroup path handling EAGAIN and EBUSY errors and
 // retrying the remove after a exp timeout
 func remove(path string) error {
+	delay := 10 * time.Millisecond
 	for i := 0; i < 5; i++ {
-		delay := 10 * time.Millisecond
 		if i != 0 {
 			time.Sleep(delay)
 			delay *= 2
@@ -204,7 +204,7 @@ func parseCgroupFromReader(r io.Reader) (map[string]string, error) {
 			parts = strings.SplitN(text, ":", 3)
 		)
 		if len(parts) < 3 {
-			return nil, fmt.Errorf("invalid cgroup entry: must contain at least two colons: %v", text)
+			return nil, fmt.Errorf("invalid cgroup entry: %q", text)
 		}
 		for _, subs := range strings.Split(parts[1], ",") {
 			if subs != "" {