From 579f3853848634ac5ecad1c8b2449f92446e2b84 Mon Sep 17 00:00:00 2001

From: Frederick Grose <fgrose@sugarlabs.org>

Date: Sun, 27 Jan 2013 14:47:17 -0500

Subject: [PATCH] Provide devices to enable booting with

 rd.live.overlay.readonly=1

---

 modules.d/90dmsquash-live/dmsquash-live-root.sh | 24 ++++++++++++++++++++----

 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/modules.d/90dmsquash-live/dmsquash-live-root.sh b/modules.d/90dmsquash-live/dmsquash-live-root.sh

index f302d44..0b1ed20 100755

--- a/modules.d/90dmsquash-live/dmsquash-live-root.sh

+++ b/modules.d/90dmsquash-live/dmsquash-live-root.sh

@@ -110,18 +110,34 @@ do_live_overlay() {

         umount -l /run/initramfs/overlayfs || :

     fi

-    if [ -z "$setup" ]; then

-        if [ -n "$devspec" -a -n "$pathspec" ]; then

+    if [ -z "$setup" -o -n "$readonly_overlay" ]; then

+        if [ -n "$setup" ]; then

+            warn "Using temporary overlay."

+        elif [ -n "$devspec" -a -n "$pathspec" ]; then

             warn "Unable to find persistent overlay; using temporary"

             sleep 5

         fi

         dd if=/dev/null of=/overlay bs=1024 count=1 seek=$((512*1024)) 2> /dev/null

-        losetup $OVERLAY_LOOPDEV /overlay

+        if [ -n "$setup" -a -n "$readonly_overlay" ]; then

+            RO_OVERLAY_LOOPDEV=$( losetup -f )

+            losetup $RO_OVERLAY_LOOPDEV /overlay

+        else

+            losetup $OVERLAY_LOOPDEV /overlay

+        fi

     fi

     # set up the snapshot

-    echo 0 `blockdev --getsz $BASE_LOOPDEV` snapshot $BASE_LOOPDEV $OVERLAY_LOOPDEV p 8 | dmsetup create $readonly_overlay live-rw

+    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

+        base="/dev/mapper/live-ro"

+        over=$RO_OVERLAY_LOOPDEV

+    else

+        base=$BASE_LOOPDEV

+        over=$OVERLAY_LOOPDEV

+    fi

+    echo 0 $sz snapshot $base $over p 8 | dmsetup create live-rw

 }

 # live cd helper function