From 28fcfcc23840a6b97d1c3d6c419118dea3db2d86 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?=
 <marmarek@invisiblethingslab.com>
Date: Tue, 4 Aug 2015 05:31:40 +0200
Subject: [PATCH] liveusb: overlayfs doesn't support sparse files, use tmpfs
 directly

This comes with some overhead, at least at the beginning, because all
private images are copied there at system startup (instead of first
use). This uses about 450MB of RAM.
Still better than non-sparse private.img (2GB...).
---
 live/livesys | 38 ++++++++++++++++++++++++++++++--------
 1 file changed, 30 insertions(+), 8 deletions(-)

diff --git a/live/livesys b/live/livesys
index 3e69cdf..be1463f 100755
--- a/live/livesys
+++ b/live/livesys
@@ -104,16 +104,38 @@ if ! strstr "`cat /proc/cmdline`" nopersistenthome && [ -n "$homedev" ] ; then
 else
   mkdir -p /home/qubes
   mount -t tmpfs none /home/qubes
+  chown root:qubes /home/qubes
+  chmod 2775 /home/qubes
 fi
 
-mkdir -p /home/qubes/qubes
-mkdir -p /home/qubes/workdir
-ln -nsf /var/lib/qubes-base/vm-templates /home/qubes/qubes/vm-templates
-mount -t overlay overlay \
-          -o lowerdir=/var/lib/qubes-base \
-          -o upperdir=/home/qubes/qubes \
-          -o workdir=/home/qubes/workdir \
-          /var/lib/qubes
+# overlay fs doesn't handle sparse files:
+#   fs/overlayfs/copy_up.c:94     /* FIXME: copy up sparse files efficiently */
+# So for now it is useless here. But some day...
+# 
+#mkdir -p /home/qubes/qubes
+#mkdir -p /home/qubes/workdir
+#ln -nsf /var/lib/qubes-base/vm-templates /home/qubes/qubes/vm-templates
+#mount -t overlay overlay \
+#          -o lowerdir=/var/lib/qubes-base \
+#          -o upperdir=/home/qubes/qubes \
+#          -o workdir=/home/qubes/workdir \
+#          /var/lib/qubes
+
+ln -nsf /var/lib/qubes-base/vm-templates /home/qubes/vm-templates
+ln -nsf /var/lib/qubes-base/vm-kernels /home/qubes/vm-kernels
+for dir in /var/lib/qubes-base/*; do
+    dir=`basename $dir`
+    case $dir in
+        vm-templates) ;;
+        vm-kernels) ;;
+        *)
+            if [ ! -e /home/qubes/$dir ]; then
+                cp -a /var/lib/qubes-base/$dir /home/qubes/
+            fi
+            ;;
+    esac
+done
+mount --bind /home/qubes /var/lib/qubes
 
 /usr/bin/qvm-prefs --offline-mode -s sys-net pcidevs '[]'
 for dev in $(/sbin/lspci -mm -n | sed -ne 's/^\([0-9][0-9]:[0-9][0-9].[0-9]\) "02.*/\1/p'); do