Opening Pod volume dir could fail if for instance the directory has stale handle or directory is busy.

In such case, don't exit if the directory cannot be opened.

Signed-off-by: Huamin Chen <hchen@redhat.com>

pkg/kubelet/volumes.go

@@ -145,7 +145,7 @@ func (kl *Kubelet) getPodVolumes(podUID types.UID) ([]*volumeTuple, error) {
 	for _, volumeKindDir := range volumeKindDirs {
 		volumeKind := volumeKindDir.Name()
 		volumeKindPath := path.Join(podVolDir, volumeKind)
-		volumeNameDirs, err := ioutil.ReadDir(volumeKindPath)
+		volumeNameDirs, err := util.ReadDirNoExit(volumeKindPath)
 		if err != nil {
 			return []*volumeTuple{}, fmt.Errorf("could not read directory %s: %v", volumeKindPath, err)
 		}

pkg/util/util.go

@@ -599,3 +599,34 @@ func RemoveAllSkipMountPoints(path string) error {
 	}
 	return err
 }
+
+// borrowed from ioutil.ReadDir
+// ReadDir reads the directory named by dirname and returns
+// a list of directory entries, ignoring lstat returns
+func ReadDirNoExit(dirname string) ([]os.FileInfo, error) {
+	if dirname == "" {
+		dirname = "."
+	}
+
+	f, err := os.Open(dirname)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	names, err := f.Readdirnames(-1)
+	list := make([]os.FileInfo, 0, len(names))
+	for _, filename := range names {
+		fip, lerr := os.Lstat(dirname + "/" + filename)
+		if os.IsNotExist(lerr) {
+			// File disappeared between readdir + stat.
+			// Just treat it as if it didn't exist.
+			continue
+		}
+		if fip != nil {
+			list = append(list, fip)
+		}
+	}
+
+	return list, nil
+}