From 1fb33aa2dafaba7cdbd4e7f00f59c51acea392a6 Mon Sep 17 00:00:00 2001
From: chengyli <chengyli@ebay.com>
Date: Sun, 24 Apr 2016 03:00:59 +0800
Subject: [PATCH] fix cinder volume dir umount issue #24717

fix https://github.com/kubernetes/kubernetes/issues/24717
If kubelet root-dir is a symlink, the pod's cinder volume dir can't be
umounted even after pod is deleted.
This patch reads target path of symlink before comparing with entries in
proc mounts.
---
 pkg/util/mount/mount.go | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/pkg/util/mount/mount.go b/pkg/util/mount/mount.go
index 8f0489a3c3e..9c1d8d4f265 100644
--- a/pkg/util/mount/mount.go
+++ b/pkg/util/mount/mount.go
@@ -21,6 +21,7 @@ package mount
 import (
 	"github.com/golang/glog"
 	"k8s.io/kubernetes/pkg/util/exec"
+	"path/filepath"
 )
 
 type Interface interface {
@@ -86,8 +87,13 @@ func GetMountRefs(mounter Interface, mountPath string) ([]string, error) {
 
 	// Find the device name.
 	deviceName := ""
+	// If mountPath is symlink, need get its target path.
+	slTarget, err := filepath.EvalSymlinks(mountPath)
+	if err != nil {
+		slTarget = mountPath
+	}
 	for i := range mps {
-		if mps[i].Path == mountPath {
+		if mps[i].Path == slTarget {
 			deviceName = mps[i].Device
 			break
 		}
@@ -99,7 +105,7 @@ func GetMountRefs(mounter Interface, mountPath string) ([]string, error) {
 		glog.Warningf("could not determine device for path: %q", mountPath)
 	} else {
 		for i := range mps {
-			if mps[i].Device == deviceName && mps[i].Path != mountPath {
+			if mps[i].Device == deviceName && mps[i].Path != slTarget {
 				refs = append(refs, mps[i].Path)
 			}
 		}
@@ -118,8 +124,13 @@ func GetDeviceNameFromMount(mounter Interface, mountPath string) (string, int, e
 	// Find the device name.
 	// FIXME if multiple devices mounted on the same mount path, only the first one is returned
 	device := ""
+	// If mountPath is symlink, need get its target path.
+	slTarget, err := filepath.EvalSymlinks(mountPath)
+	if err != nil {
+		slTarget = mountPath
+	}
 	for i := range mps {
-		if mps[i].Path == mountPath {
+		if mps[i].Path == slTarget {
 			device = mps[i].Device
 			break
 		}