From eb18a1fe29a3ffcd646fe6d25ae2d7d998b63e71 Mon Sep 17 00:00:00 2001
From: Frederick Grose <fgrose@sugarlabs.org>
Date: Mon, 20 Aug 2018 19:52:53 -0400
Subject: [PATCH] dmsquash-live, livenet: Simplify OverlayFS read-only overlay
setup.
Use multiple lower layer directories in a single OverlayFS mount with
a transient overlay directory.
Tolerate a command line with rd.live.overlay.readonly and NO persistent
overlay by reconfiguring the OverlayFS mount options.
Use more compatible shell syntax for testing symlinks, and use printf
instead of echo -e.
---
modules.d/90dmsquash-live/dmsquash-generator.sh | 9 ++++++-
modules.d/90dmsquash-live/dmsquash-live-root.sh | 34 ++++++++++++++-----------
modules.d/90livenet/livenet-generator.sh | 9 ++++++-
3 files changed, 35 insertions(+), 17 deletions(-)
diff --git a/modules.d/90dmsquash-live/dmsquash-generator.sh b/modules.d/90dmsquash-live/dmsquash-generator.sh
index fe190012..1129ddff 100755
--- a/modules.d/90dmsquash-live/dmsquash-generator.sh
+++ b/modules.d/90dmsquash-live/dmsquash-generator.sh
@@ -54,8 +54,10 @@ GENERATOR_DIR="$2"
[ -z "$GENERATOR_DIR" ] && exit 1
[ -d "$GENERATOR_DIR" ] || mkdir "$GENERATOR_DIR"
+getargbool 0 rd.live.overlay.readonly -d -y readonly_overlay && readonly_overlay="--readonly" || readonly_overlay=""
getargbool 0 rd.live.overlay.overlayfs && overlayfs="yes"
[ -e /xor_overlayfs ] && xor_overlayfs="yes"
+[ -e /xor_readonly ] && xor_readonly="--readonly"
ROOTFLAGS="$(getarg rootflags)"
{
echo "[Unit]"
@@ -64,7 +66,12 @@ ROOTFLAGS="$(getarg rootflags)"
echo "Where=/sysroot"
if [ "$overlayfs$xor_overlayfs" = "yes" ]; then
echo "What=LiveOS_rootfs"
- echo "Options=${ROOTFLAGS},lowerdir=/run/rootfsbase,upperdir=/run/overlayfs,workdir=/run/ovlwork"
+ if [ "$readonly_overlay$xor_readonly" = "--readonly" ]; then
+ ovlfs=lowerdir=/run/overlayfs-r:/run/rootfsbase
+ else
+ ovlfs=lowerdir=/run/rootfsbase
+ fi
+ echo "Options=${ROOTFLAGS},${ovlfs},upperdir=/run/overlayfs,workdir=/run/ovlwork"
echo "Type=overlay"
_dev=LiveOS_rootfs
else
diff --git a/modules.d/90dmsquash-live/dmsquash-live-root.sh b/modules.d/90dmsquash-live/dmsquash-live-root.sh
index 0c5e010e..0f3d8f89 100755
--- a/modules.d/90dmsquash-live/dmsquash-live-root.sh
+++ b/modules.d/90dmsquash-live/dmsquash-live-root.sh
@@ -137,7 +137,7 @@ do_live_overlay() {
fi
if [ -n "$overlayfs" ]; then
unset -v overlayfs
- [ -n "$DRACUT_SYSTEMD" ] && reloadsysrootmountunit="yes"
+ [ -n "$DRACUT_SYSTEMD" ] && reloadsysrootmountunit=":>/xor_overlayfs;"
fi
setup="yes"
else
@@ -148,7 +148,7 @@ do_live_overlay() {
ln -s /run/initramfs/overlayfs/ovlwork /run/ovlwork$opt
if [ -z "$overlayfs" ]; then
overlayfs="yes"
- [ -n "$DRACUT_SYSTEMD" ] && reloadsysrootmountunit="yes"
+ [ -n "$DRACUT_SYSTEMD" ] && reloadsysrootmountunit=":>/xor_overlayfs;"
fi
setup="yes"
fi
@@ -159,7 +159,7 @@ do_live_overlay() {
ln -s /run/initramfs/overlayfs$pathspec/../ovlwork /run/ovlwork$opt
if [ -z "$overlayfs" ]; then
overlayfs="yes"
- [ -n "$DRACUT_SYSTEMD" ] && reloadsysrootmountunit="yes"
+ [ -n "$DRACUT_SYSTEMD" ] && reloadsysrootmountunit=":>/xor_overlayfs;"
fi
setup="yes"
fi
@@ -168,8 +168,7 @@ do_live_overlay() {
modprobe overlay
if [ $? != 0 ]; then
m='OverlayFS is not available; using temporary Device-mapper overlay.'
- unset -v overlayfs setup
- [ -n "$reloadsysrootmountunit" ] && unset -v reloadsysrootmountunit
+ unset -v overlayfs setup reloadsysrootmountunit
fi
fi
@@ -181,7 +180,7 @@ do_live_overlay() {
m=' Unable to find a persistent overlay; using a temporary one.'
m="$m"$'\n All root filesystem changes will be lost on shutdown.'
m="$m"$'\n Press [Enter] to continue.'
- echo -e "\n\n\n\n${m}\n\n\n" > /dev/kmsg
+ printf "\n\n\n\n${m}\n\n\n" > /dev/kmsg
if [ -n "$DRACUT_SYSTEMD" ]; then
if type plymouth >/dev/null 2>&1 && plymouth --ping ; then
if getargbool 0 rhgb || getargbool 0 splash ; then
@@ -203,6 +202,11 @@ do_live_overlay() {
if [ -n "$overlayfs" ]; then
mkdir -m 0755 /run/overlayfs
mkdir -m 0755 /run/ovlwork
+ if [ -n "$readonly_overlay" ] && ! [ -h /run/overlayfs-r ]; then
+ info "No persistent overlay found."
+ unset -v readonly_overlay
+ [ -n "$DRACUT_SYSTEMD" ] && reloadsysrootmountunit="${reloadsysrootmountunit}:>/xor_readonly;"
+ fi
else
dd if=/dev/null of=/overlay bs=1024 count=1 seek=$((overlay_size*1024)) 2> /dev/null
if [ -n "$setup" -a -n "$readonly_overlay" ]; then
@@ -256,6 +260,7 @@ do_live_overlay() {
fi
ln -s $BASE_LOOPDEV /dev/live-base
}
+# end do_live_overlay()
# we might have a genMinInstDelta delta file for anaconda to take advantage of
if [ -e /run/initramfs/live/${live_dir}/osmin.img ]; then
@@ -299,7 +304,7 @@ if [ -e "$SQUASHED" ]; then
FSIMG=$SQUASHED
if [ -z "$overlayfs" ]; then
overlayfs="yes"
- [ -n "$DRACUT_SYSTEMD" ] && reloadsysrootmountunit="yes"
+ [ -n "$DRACUT_SYSTEMD" ] && reloadsysrootmountunit=":>/xor_overlayfs;"
fi
else
die "Failed to find a root filesystem in $SQUASHED."
@@ -366,7 +371,7 @@ if [ -b "$OSMIN_LOOPDEV" ]; then
fi
if [ -n "$reloadsysrootmountunit" ]; then
- > /xor_overlayfs
+ eval "$reloadsysrootmountunit"
systemctl daemon-reload
fi
@@ -374,21 +379,20 @@ ROOTFLAGS="$(getarg rootflags)"
if [ -n "$overlayfs" ]; then
mkdir -m 0755 /run/rootfsbase
- if [ -n "$reset_overlay" ] && [ -L /run/overlayfs ]; then
+ if [ -n "$reset_overlay" ] && [ -h /run/overlayfs ]; then
ovlfs=$(readlink /run/overlayfs)
info "Resetting the OverlayFS overlay directory."
rm -r -- ${ovlfs}/* ${ovlfs}/.* >/dev/null 2>&1
fi
- if [ -n "$readonly_overlay" ]; then
- mkdir -m 0755 /run/rootfsbase-r
- mount -r $FSIMG /run/rootfsbase-r
- mount -t overlay LiveOS_rootfs-r -oro,lowerdir=/run/overlayfs-r:/run/rootfsbase-r /run/rootfsbase
+ if [ -n "$readonly_overlay" ] && [ -h /run/overlayfs-r ]; then
+ ovlfs=lowerdir=/run/overlayfs-r:/run/rootfsbase
else
- mount -r $FSIMG /run/rootfsbase
+ ovlfs=lowerdir=/run/rootfsbase
fi
+ mount -r $FSIMG /run/rootfsbase
if [ -z "$DRACUT_SYSTEMD" ]; then
printf 'mount -t overlay LiveOS_rootfs -o%s,%s %s\n' "$ROOTFLAGS" \
- 'lowerdir=/run/rootfsbase,upperdir=/run/overlayfs,workdir=/run/ovlwork' \
+ "$ovlfs",upperdir=/run/overlayfs,workdir=/run/ovlwork \
"$NEWROOT" > $hookdir/mount/01-$$-live.sh
fi
else
diff --git a/modules.d/90livenet/livenet-generator.sh b/modules.d/90livenet/livenet-generator.sh
index e2b5b6eb..f0d12851 100755
--- a/modules.d/90livenet/livenet-generator.sh
+++ b/modules.d/90livenet/livenet-generator.sh
@@ -43,8 +43,10 @@ GENERATOR_DIR="$2"
[ -d "$GENERATOR_DIR" ] || mkdir "$GENERATOR_DIR"
+getargbool 0 rd.live.overlay.readonly -d -y readonly_overlay && readonly_overlay="--readonly" || readonly_overlay=""
getargbool 0 rd.live.overlay.overlayfs && overlayfs="yes"
[ -e /xor_overlayfs ] && xor_overlayfs="yes"
+[ -e /xor_readonly ] && xor_readonly="--readonly"
ROOTFLAGS="$(getarg rootflags)"
{
echo "[Unit]"
@@ -53,7 +55,12 @@ ROOTFLAGS="$(getarg rootflags)"
echo "Where=/sysroot"
if [ "$overlayfs$xor_overlayfs" = "yes" ]; then
echo "What=LiveOS_rootfs"
- echo "Options=${ROOTFLAGS},lowerdir=/run/rootfsbase,upperdir=/run/overlayfs,workdir=/run/ovlwork"
+ if [ "$readonly_overlay$xor_readonly" = "--readonly" ]; then
+ ovlfs=lowerdir=/run/overlayfs-r:/run/rootfsbase
+ else
+ ovlfs=lowerdir=/run/rootfsbase
+ fi
+ echo "Options=${ROOTFLAGS},${ovlfs},upperdir=/run/overlayfs,workdir=/run/ovlwork"
echo "Type=overlay"
_dev=LiveOS_rootfs
else