From 0ed762f2d2ff613052b81d06509dac06b13fc0c9 Mon Sep 17 00:00:00 2001
From: Alexander Larsson <alexl@redhat.com>
Date: Tue, 19 Nov 2013 14:40:15 +0100
Subject: [PATCH] devicemapper: Unmount when removing device

Without this the remove will fail due to a busy device.
---
 graphdriver/devmapper/driver.go | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/graphdriver/devmapper/driver.go b/graphdriver/devmapper/driver.go
index 315b7b091e..84d53e666e 100644
--- a/graphdriver/devmapper/driver.go
+++ b/graphdriver/devmapper/driver.go
@@ -61,6 +61,10 @@ func (d *Driver) Create(id string, parent string) error {
 }
 
 func (d *Driver) Remove(id string) error {
+	mp := path.Join(d.home, "mnt", id)
+	if err := d.unmount(id, mp); err != nil {
+		return err
+	}
 	return d.DeviceSet.RemoveDevice(id)
 }
 
@@ -90,3 +94,14 @@ func (d *Driver) mount(id, mountPoint string) error {
 	// Mount the device
 	return d.DeviceSet.MountDevice(id, mountPoint, false)
 }
+
+func (d *Driver) unmount(id, mountPoint string) error {
+	// If mountpoint is not mounted, do nothing
+	if mounted, err := Mounted(mountPoint); err != nil {
+		return fmt.Errorf("Error checking mountpoint: %s", err)
+	} else if !mounted {
+		return nil
+	}
+	// Unmount the device
+	return d.DeviceSet.UnmountDevice(id, mountPoint, true)
+}