From 7ebb3d11d92755e65ab3854f73291726c3567c7f Mon Sep 17 00:00:00 2001
From: Thomas Backlund <tmb@mageia.org>
Date: Sat, 19 Oct 2013 19:27:20 +0100
Subject: [PATCH] mgalive: A module to mount Mageia Live media

Updated to work with overlay from 3.19
Signed-off-by: Thomas Backlund <tmb@mageia.org>

Updated to support persistence and multi-boot USB sticks.
Signed-off-by: Martin Whitaker <mageia@martin-whitaker.me.uk>

Updated to eject CD and pause on shutdown.
Signed-off-by: Martin Whitaker <mageia@martin-whitaker.me.uk>

Updated to support encrypted persistent partition and fix mga#25924.
Signed-off-by: Martin Whitaker <mageia@martin-whitaker.me.uk>

Updated to handle /dev/disk/by-label linking to base device, not first partition (mga#27638).
Signed-off-by: Martin Whitaker <mageia@martin-whitaker.me.uk>

Updated to add boot option to temporarily disable persistence (mga#27674).
Signed-off-by: Martin Whitaker <mageia@martin-whitaker.me.uk>

Updated to ensure udev has re-added the protective partition before trying to mount it (mga#27638).
Signed-off-by: Martin Whitaker <mageia@martin-whitaker.me.uk>

Updated to ensure shutdown message is displayed on current tty.
Signed-off-by: Martin Whitaker <mageia@martin-whitaker.me.uk>

diff --git a/modules.d/90mgalive/mgalive-genrules.sh b/modules.d/90mgalive/mgalive-genrules.sh
new file mode 100755
index 00000000..f450ebfa
--- /dev/null
+++ b/modules.d/90mgalive/mgalive-genrules.sh
@@ -0,0 +1,18 @@
+#!/bin/sh
+
+case "$root" in
+  mgalive:/dev/*)
+    {
+        printf 'KERNEL=="%s", RUN+="/sbin/initqueue --settled --onetime --unique /sbin/mgalive-root $env{DEVNAME}"\n' \
+            ${root#mgalive:/dev/}
+        printf 'SYMLINK=="%s", RUN+="/sbin/initqueue --settled --onetime --unique /sbin/mgalive-root $env{DEVNAME}"\n' \
+            ${root#mgalive:/dev/}
+    } >> /etc/udev/rules.d/99-mgalive.rules
+    wait_for_dev "${root#mgalive:}"
+  ;;
+  mgalive:*)
+    if [ -f "${root#mgalive:}" ]; then
+        /sbin/initqueue --settled --onetime --unique /sbin/mgalive-root "${root#mgalive:}"
+    fi
+  ;;
+esac
diff --git a/modules.d/90mgalive/mgalive-parse.sh b/modules.d/90mgalive/mgalive-parse.sh
new file mode 100755
index 00000000..c5225ba4
--- /dev/null
+++ b/modules.d/90mgalive/mgalive-parse.sh
@@ -0,0 +1,31 @@
+#!/bin/sh
+# live images are specified with
+# root=mgalive:backingdev
+
+[ -z "$root" ] && root=$(getarg root=)
+
+if [ "${root%%:*}" = "mgalive" ] ; then
+    liveroot=$root
+fi
+
+[ "${liveroot%%:*}" = "mgalive" ] || return
+
+modprobe -q loop
+
+case "$liveroot" in
+    mgalive:LABEL=*|LABEL=*) \
+        root="${root#mgalive:}"
+        root="$(echo $root | sed 's,/,\\x2f,g')"
+        root="mgalive:/dev/disk/by-label/${root#LABEL=}"
+        rootok=1 ;;
+    mgalive:UUID=*|UUID=*) \
+        root="${root#mgalive:}"
+        root="mgalive:/dev/disk/by-uuid/${root#UUID=}"
+        rootok=1 ;;
+esac
+info "root was $liveroot, is now $root"
+
+# make sure that init doesn't complain
+[ -z "$root" ] && root="mgalive"
+
+wait_for_dev /live/union
diff --git a/modules.d/90mgalive/mgalive-quit-plymouth.sh b/modules.d/90mgalive/mgalive-quit-plymouth.sh
new file mode 100755
index 00000000..50fe9532
--- /dev/null
+++ b/modules.d/90mgalive/mgalive-quit-plymouth.sh
@@ -0,0 +1,6 @@
+#!/bin/sh
+if [ -x /bin/plymouth ] ; then
+    /bin/plymouth --quit
+    /bin/plymouth --wait
+fi
+return 0
diff --git a/modules.d/90mgalive/mgalive-root.sh b/modules.d/90mgalive/mgalive-root.sh
new file mode 100755
index 00000000..5ae05e8c
--- /dev/null
+++ b/modules.d/90mgalive/mgalive-root.sh
@@ -0,0 +1,163 @@
+#!/usr/bin/sh
+
+. /lib/dracut-lib.sh
+
+can_decrypt=0
+if [ -f /lib/dracut-crypt-lib.sh ] ; then
+    . /lib/dracut-crypt-lib.sh
+    can_decrypt=1
+fi
+
+[ -f /tmp/root.info ] && . /tmp/root.info
+
+PATH=/usr/sbin:/usr/bin:/sbin:/bin
+
+[ -z "$1" ] && exit 1
+livedev="$1"
+
+# Create the live tree
+mkdir -m 0755 -p /live/distrib
+mkdir -m 0755 -p /live/media
+mkdir -m 0755 -p /live/overlay
+mkdir -m 0755 -p /live/union
+mkdir -m 0755 -p /run/mgalive/ovlsize
+
+# Get the base device name
+basedev=$(echo $livedev | sed -e 's,\(/dev/sd[a-z]\)1,\1,g' -e 's,\(/dev/mmcblk[0-9]\)p1,\1,g')
+# Make it available to draklive-install and mgalive-shutdown
+echo $basedev > /run/mgalive/basedev
+
+# Unlock any encrypted partitions on the base device
+if [ $can_decrypt -eq 1 ] ; then
+    for dev in $(blkid -t TYPE=crypto_LUKS -o device | grep $basedev) ; do
+        ask_for_password \
+            --ply-cmd "cryptsetup open -T1 $dev crypt_${dev##/dev/}" \
+            --ply-prompt "Password ($dev)" \
+            --ply-tries 3 \
+            --tty-cmd "cryptsetup open -T3 $dev crypt_${dev##/dev/}" \
+            --tty-tries 1
+    done
+fi
+
+# Get the base directory for locating the loopback file. In normal use this is
+# the root directory, but a multi-boot USB stick may want to override this.
+basedir=$(getarg mgalive.basedir)
+
+# Get the device or path used for persistent storage (if it exists). In normal
+# use this is another partition on the same base device, but a multi-boot USB
+# stick may want to override this.
+overlay=$(getarg mgalive.overlay)
+if [ -z "$overlay" ] ; then
+    overlay=$(blkid -t LABEL=mgalive-persist -o device | grep $basedev'\|'/dev/mapper)
+elif [ "$overlay" = "ram" ] ; then
+    overlay=
+else
+    overlay=$livedev$overlay
+fi
+
+# If the base device is partitioned (i.e. it's a USB stick, not a DVD), get the
+# device name and start offset of the first partition. This is the protective
+# partition covering the iso9660 filesystem.
+if [ $livedev = $basedev ] ; then
+    ps=0
+    case $basedev in
+      /dev/sd*)
+        test -b ${basedev}1  && livedev=${basedev}1  && ps=$(partx -go START $livedev)
+        ;;
+      /dev/mmblk*)
+        test -b ${basedev}p1 && livedev=${basedev}p1 && ps=$(partx -go START $livedev)
+        ;;
+    esac
+else
+    ps=$(partx -go START $livedev)
+fi
+
+info "mgalive basedev is $basedev"
+info "mgalive livedev is $livedev"
+info "mgalive basedir is $basedir/"
+info "mgalive overlay is $overlay"
+
+media=$livedev
+
+if [ $ps -ne 0 ] ; then
+    if strstr "$(blkid $basedev)" "iso9660" ; then
+        # This happens when we boot from a USB stick with a isohybrid partition
+        # scheme where the first sector is unclaimed, so the first partition starts
+        # at sector 1. The iso9660 filesystem starts at sector 0, so blkid doesn't
+        # detect a valid filesystem in the first partition. In the past, udev linked
+        # the entry in /dev/disk/by-label to the first partition, not to the raw
+        # device, and that is what we got passed in $1 (mga#3334). More recently,
+        # udev links it to the base device (mga#27629). The preceding tests ensure
+        # we handle both cases.
+        if [ -n "$overlay" ] ; then
+            # If we mount the raw device, we can't then also mount a partition
+            # on that device. So to enable persistence, we need to extend the
+            # first partition to claim the full range  of the iso9660 filesystem.
+            # The loops waiting for udev are to ensure we don't try to mount the
+            # partition in the small window when udev has removed it but not yet
+            # re-added it (mga#27638).
+            pe=$(partx -go END   $livedev)
+            if [ $ps -eq 1 ] ; then
+                info "Extending $livedev to cover sector 0"
+                delpart $basedev 1
+                while [ -e $livedev ] ; do
+                    info "Wait for udev to remove $livedev"
+                done
+                addpart $basedev 1 0 $pe
+                while [ ! -e $livedev ] ; do
+                    info "Wait for udev to re-add $livedev"
+                done
+            else
+                info "$livedev is not a valid protective partition"
+            fi
+        else
+            # If we don't have a persistent partition, take the easy option.
+            info "Using $basedev to mount the iso9660 filesystem"
+            media=$basedev
+        fi
+    else
+        info "$basedev does not contain a valid filesystem"
+    fi
+fi
+
+# Mount the live media
+mount -n -o ro $media /live/media
+
+# Mount the loopback filesystem
+LOOPDEV=$( losetup -f )
+if [ -e /live/media$basedir/loopbacks/distrib-lzma.sqfs ] ; then
+    # Retain support for the original draklive. Note that despite the file
+    # name, it uses xz compression.
+    losetup -r $LOOPDEV /live/media$basedir/loopbacks/distrib-lzma.sqfs
+else
+    losetup -r $LOOPDEV /live/media$basedir/loopbacks/distrib.sqfs
+fi
+mount -n -t squashfs -o ro $LOOPDEV /live/distrib
+mount -n -t squashfs -o ro $LOOPDEV /run/mgalive/ovlsize
+
+# Mount the overlay filesystem
+if [ -z "$overlay" ] ; then
+    mount -n -t tmpfs -o mode=755 none /live/overlay
+else
+    mount -n -o noatime $overlay /live/overlay
+    echo 1 > /run/mgalive/persistent
+fi
+# work and memory must be on same root
+mkdir -m 0755 -p /live/overlay/work
+mkdir -m 0755 -p /live/overlay/memory
+mount -n -t overlay overlay -o lowerdir=/live/distrib,upperdir=/live/overlay/memory,workdir=/live/overlay/work,noatime /live/union
+
+ln -s /live/union /dev/root
+
+printf '/bin/mount --rbind /live/union %s\n' "$NEWROOT" > $hookdir/mount/01-$$-live.sh
+printf '/bin/umount /live/union\n'                     >> $hookdir/mount/01-$$-live.sh
+
+# /live will not be visible once we pivot, so schedule its cleanup now.
+# This is needed to allow a persistent overlay to be shutdown cleanly.
+umount -l /live/distrib
+umount -l /live/overlay
+umount -l /live/media
+
+need_shutdown
+
+exit 0
diff --git a/modules.d/90mgalive/mgalive-shutdown.sh b/modules.d/90mgalive/mgalive-shutdown.sh
new file mode 100755
index 00000000..b93bb068
--- /dev/null
+++ b/modules.d/90mgalive/mgalive-shutdown.sh
@@ -0,0 +1,11 @@
+#!/usr/bin/sh
+basedev=$(cat /run/mgalive/basedev)
+if [ -e /run/mgalive/installed ] || strstr "$basedev" "/dev/sr" ; then
+    exec < /dev/tty0 > /dev/tty0
+    eject $basedev
+    clear
+    echo "It is now safe to remove the Live medium"
+    echo "Press <Enter> to continue..."
+    read -t 30 a
+fi
+return 0
diff --git a/modules.d/90mgalive/module-setup.sh b/modules.d/90mgalive/module-setup.sh
new file mode 100755
index 00000000..260f4e8b
--- /dev/null
+++ b/modules.d/90mgalive/module-setup.sh
@@ -0,0 +1,28 @@
+#!/bin/bash
+
+check() {
+    # a live host-only image doesn't really make a lot of sense
+    [[ $hostonly ]] && return 1
+    return 255
+}
+
+depends() {
+    return 0
+}
+
+installkernel() {
+    instmods squashfs loop overlay
+}
+
+install() {
+    inst_multiple blkid clear eject grep losetup umount
+    inst_multiple addpart delpart partx
+
+    inst_hook cmdline 30 "$moddir/mgalive-parse.sh"
+    inst_hook pre-udev 30 "$moddir/mgalive-genrules.sh"
+    inst_hook pre-shutdown 99 "$moddir/mgalive-quit-plymouth.sh"
+    inst_hook shutdown 99 "$moddir/mgalive-shutdown.sh"
+    inst "$moddir/mgalive-root.sh" "/sbin/mgalive-root"
+    # should probably just be generally included
+    inst_rules 60-cdrom_id.rules
+}
-- 
2.13.7