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)"