From 906fd7529e3f7ea3cc1ff753b3d36115be061394 Mon Sep 17 00:00:00 2001
From: Jan Safranek <jsafrane@redhat.com>
Date: Wed, 9 May 2018 09:52:37 +0200
Subject: [PATCH] Fix iSCSI and RBD UnmountDevice with mount containers.

Google's configure-helper.sh script bind-mounts /var/lib/kubelet somewhere
into /home/kubernetes and thus every mount that Kubernetes does is visible
twice in /proc/mounts.

iSCSI and RBD should not rely on counting on entries in /proc/mounts and
unmount device when Kubernetes thinks it's unusued. Kubernetes tracks
the mounts by itself and most of other volume plugins rely on it safely.
---
 pkg/volume/iscsi/iscsi_util.go | 11 +----------
 pkg/volume/rbd/attacher.go     | 18 +++++++-----------
 2 files changed, 8 insertions(+), 21 deletions(-)

diff --git a/pkg/volume/iscsi/iscsi_util.go b/pkg/volume/iscsi/iscsi_util.go
index ad6382f308f..d649e351729 100644
--- a/pkg/volume/iscsi/iscsi_util.go
+++ b/pkg/volume/iscsi/iscsi_util.go
@@ -396,25 +396,16 @@ func globalPDPathOperation(b iscsiDiskMounter) func(iscsiDiskMounter, string, *I
 
 // DetachDisk unmounts and detaches a volume from node
 func (util *ISCSIUtil) DetachDisk(c iscsiDiskUnmounter, mntPath string) error {
-	_, cnt, err := mount.GetDeviceNameFromMount(c.mounter, mntPath)
-	if err != nil {
-		glog.Errorf("iscsi detach disk: failed to get device from mnt: %s\nError: %v", mntPath, err)
-		return err
-	}
 	if pathExists, pathErr := volumeutil.PathExists(mntPath); pathErr != nil {
 		return fmt.Errorf("Error checking if path exists: %v", pathErr)
 	} else if !pathExists {
 		glog.Warningf("Warning: Unmount skipped because path does not exist: %v", mntPath)
 		return nil
 	}
-	if err = c.mounter.Unmount(mntPath); err != nil {
+	if err := c.mounter.Unmount(mntPath); err != nil {
 		glog.Errorf("iscsi detach disk: failed to unmount: %s\nError: %v", mntPath, err)
 		return err
 	}
-	cnt--
-	if cnt != 0 {
-		return nil
-	}
 	// if device is no longer used, see if need to logout the target
 	device, prefix, err := extractDeviceAndPrefix(mntPath)
 	if err != nil {
diff --git a/pkg/volume/rbd/attacher.go b/pkg/volume/rbd/attacher.go
index 2e5960092e1..9a74a608c33 100644
--- a/pkg/volume/rbd/attacher.go
+++ b/pkg/volume/rbd/attacher.go
@@ -189,21 +189,17 @@ func (detacher *rbdDetacher) UnmountDevice(deviceMountPath string) error {
 		glog.Warningf("Warning: Unmount skipped because path does not exist: %v", deviceMountPath)
 		return nil
 	}
-	devicePath, cnt, err := mount.GetDeviceNameFromMount(detacher.mounter, deviceMountPath)
+	devicePath, _, err := mount.GetDeviceNameFromMount(detacher.mounter, deviceMountPath)
 	if err != nil {
 		return err
 	}
-	if cnt > 1 {
-		return fmt.Errorf("rbd: more than 1 reference counts at %s", deviceMountPath)
-	}
-	if cnt == 1 {
-		// Unmount the device from the device mount point.
-		glog.V(4).Infof("rbd: unmouting device mountpoint %s", deviceMountPath)
-		if err = detacher.mounter.Unmount(deviceMountPath); err != nil {
-			return err
-		}
-		glog.V(3).Infof("rbd: successfully umount device mountpath %s", deviceMountPath)
+	// Unmount the device from the device mount point.
+	glog.V(4).Infof("rbd: unmouting device mountpoint %s", deviceMountPath)
+	if err = detacher.mounter.Unmount(deviceMountPath); err != nil {
+		return err
 	}
+	glog.V(3).Infof("rbd: successfully umount device mountpath %s", deviceMountPath)
+
 	glog.V(4).Infof("rbd: detaching device %s", devicePath)
 	err = detacher.manager.DetachDisk(detacher.plugin, deviceMountPath, devicePath)
 	if err != nil {