can't unmount if cwd is in copy
diff --git a/tools/build_kvm.sh b/tools/build_kvm.sh
index 59ed649..23ce493 100755
--- a/tools/build_kvm.sh
+++ b/tools/build_kvm.sh
@@ -148,12 +148,12 @@
 git_clone $KEYSTONE_REPO $COPY_DIR/$DEST/keystone $KEYSTONE_BRANCH
 git_clone $NOVNC_REPO $COPY_DIR/$DEST/noVNC $NOVNC_BRANCH
 
-# Unmount the filesystems
-unmount_images
-
 # Back to devstack
 cd $TOP_DIR
 
+# Unmount the filesystems
+unmount_images
+
 # Network configuration variables
 BRIDGE=${BRIDGE:-br0}
 GUEST_IP=${GUEST_IP:-192.168.1.50}