From 49c9d8174ff7c25158861872bc0ea04a8cf2d242 Mon Sep 17 00:00:00 2001
From: Frederick Grose <fgrose@sugarlabs.org>
Date: Mon, 9 Nov 2015 10:46:27 -0800
Subject: [PATCH] dmsquash-live-root: Use non-persistent metadata snapshots.

Transient snapshots can take advantage of smaller,
   non-persistent metadata structures.
Make the --readonly option explicit rather than inferred
   for the readonly_overlay target.
Assure that the live-base target is on the BASE_LOOPDEV.
---
 modules.d/90dmsquash-live/dmsquash-live-root.sh | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/modules.d/90dmsquash-live/dmsquash-live-root.sh b/modules.d/90dmsquash-live/dmsquash-live-root.sh
index 531617e..caf473b 100755
--- a/modules.d/90dmsquash-live/dmsquash-live-root.sh
+++ b/modules.d/90dmsquash-live/dmsquash-live-root.sh
@@ -141,7 +141,7 @@ do_live_overlay() {
     # set up the snapshot
     sz=$(blockdev --getsz $BASE_LOOPDEV)
     if [ -n "$readonly_overlay" ]; then
-        echo 0 $sz snapshot $BASE_LOOPDEV $OVERLAY_LOOPDEV p 8 | dmsetup create $readonly_overlay live-ro
+        echo 0 $sz snapshot $BASE_LOOPDEV $OVERLAY_LOOPDEV N 8 | dmsetup create --readonly live-ro
         base="/dev/mapper/live-ro"
         over=$RO_OVERLAY_LOOPDEV
     else
@@ -175,7 +175,7 @@ do_live_overlay() {
     fi
 
     # Create a device that always points to a ro base image
-    echo 0 $sz linear $base 0 | dmsetup create --readonly live-base
+    echo 0 $sz linear $BASE_LOOPDEV 0 | dmsetup create --readonly live-base
 }
 
 # live cd helper function
@@ -259,7 +259,7 @@ fi
 if [ -b "$OSMIN_LOOPDEV" ]; then
     # set up the devicemapper snapshot device, which will merge
     # the normal live fs image, and the delta, into a minimzied fs image
-    echo "0 $( blockdev --getsz $BASE_LOOPDEV ) snapshot $BASE_LOOPDEV $OSMIN_LOOPDEV p 8" | dmsetup create --readonly live-osimg-min
+    echo "0 $( blockdev --getsz $BASE_LOOPDEV ) snapshot $BASE_LOOPDEV $OSMIN_LOOPDEV N 8" | dmsetup create --readonly live-osimg-min
 fi
 
 ROOTFLAGS="$(getarg rootflags)"