fix golint issues for pkg/volume/empty_dir

pkg/volume/emptydir/empty_dir_linux.go

@@ -0,0 +1,60 @@
+// +build linux
+
+/*
+Copyright 2015 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package emptydir
+
+import (
+	"fmt"
+
+	"github.com/golang/glog"
+	"golang.org/x/sys/unix"
+
+	"k8s.io/api/core/v1"
+	"k8s.io/kubernetes/pkg/util/mount"
+)
+
+// Defined by Linux - the type number for tmpfs mounts.
+const (
+	linuxTmpfsMagic     = 0x01021994
+	linuxHugetlbfsMagic = 0x958458f6
+)
+
+// realMountDetector implements mountDetector in terms of syscalls.
+type realMountDetector struct {
+	mounter mount.Interface
+}
+
+func (m *realMountDetector) GetMountMedium(path string) (v1.StorageMedium, bool, error) {
+	glog.V(5).Infof("Determining mount medium of %v", path)
+	notMnt, err := m.mounter.IsLikelyNotMountPoint(path)
+	if err != nil {
+		return v1.StorageMediumDefault, false, fmt.Errorf("IsLikelyNotMountPoint(%q): %v", path, err)
+	}
+	buf := unix.Statfs_t{}
+	if err := unix.Statfs(path, &buf); err != nil {
+		return v1.StorageMediumDefault, false, fmt.Errorf("statfs(%q): %v", path, err)
+	}
+
+	glog.V(5).Infof("Statfs_t of %v: %+v", path, buf)
+	if buf.Type == linuxTmpfsMagic {
+		return v1.StorageMediumMemory, !notMnt, nil
+	} else if int64(buf.Type) == linuxHugetlbfsMagic {
+		return v1.StorageMediumHugePages, !notMnt, nil
+	}
+	return v1.StorageMediumDefault, !notMnt, nil
+}