From 721b6073c53f007ac5bff1b5f79826472d71bf3c Mon Sep 17 00:00:00 2001
From: cshore <cshore@3c298f89-4303-0410-b956-a3cf2f4a3e73>
Date: Fri, 3 Dec 2010 21:20:57 +0000
Subject: [PATCH] [package] block-extroot: Merged 24230 from trunk: Added an
 md5sum to extroot and underlying root, which is used to ensure that extroot
 is not mounted after sysupgrade (until user deals with the necessary changes
 to the extroot)

git-svn-id: svn://svn.openwrt.org/openwrt/branches/backfire@24231 3c298f89-4303-0410-b956-a3cf2f4a3e73
---
 package/block-extroot/Makefile                |  1 +
 .../block-extroot/files/50_determine_usb_root |  1 +
 .../files/55_determine_extroot_sysupgrade     | 55 +++++++++++++++++++
 3 files changed, 57 insertions(+)
 create mode 100644 package/block-extroot/files/55_determine_extroot_sysupgrade

diff --git a/package/block-extroot/Makefile b/package/block-extroot/Makefile
index f1e093bcc..05d5e18a1 100644
--- a/package/block-extroot/Makefile
+++ b/package/block-extroot/Makefile
@@ -53,6 +53,7 @@ define Package/block-extroot/install
 	$(INSTALL_DATA) ./files/extmount.sh $(1)/lib/functions/
 	$(INSTALL_DIR) $(1)/lib/preinit
 	$(INSTALL_DATA) ./files/50_determine_usb_root $(1)/lib/preinit/
+	$(INSTALL_DATA) ./files/55_determine_extroot_sysupgrade $(1)/lib/preinit/
 	$(INSTALL_DATA) ./files/60_pivot_usb_root $(1)/lib/preinit/
 	$(INSTALL_DIR) $(1)/lib/preinit
 	echo "extroot_settle_time=\"$(CONFIG_EXTROOT_SETTLETIME)\"" >$(1)/lib/preinit/00_extroot.conf
diff --git a/package/block-extroot/files/50_determine_usb_root b/package/block-extroot/files/50_determine_usb_root
index b899203e5..e87855c2a 100644
--- a/package/block-extroot/files/50_determine_usb_root
+++ b/package/block-extroot/files/50_determine_usb_root
@@ -18,6 +18,7 @@ determine_external_root() {
 	if [ "$jffs" = "/tmp/overlay" ] && [ -r "/tmp/overlay/etc/config/fstab" ]; then
 		UCI_CONFIG_DIR="/tmp/overlay/etc/config"
 		ER_IS_SQUASHFS=true
+		ER_OVERLAY_PREFIX="/tmp/overlay"
 	fi
 
 	# For squashfs on firstboot root_device will be tmpfs for the ramoverlay,
diff --git a/package/block-extroot/files/55_determine_extroot_sysupgrade b/package/block-extroot/files/55_determine_extroot_sysupgrade
new file mode 100644
index 000000000..21af8b018
--- /dev/null
+++ b/package/block-extroot/files/55_determine_extroot_sysupgrade
@@ -0,0 +1,55 @@
+#!/bin/sh
+# Copyright (C) 2010 Daniel Dickinson
+# This is free software, licensed under the GNU General Public License v2.
+# See /LICENSE for more information.
+
+
+check_set_md5sum() {
+	local er_md5sum_file
+	er_md5sum_file="${ER_OVERLAY_PREFIX}/.extroot.md5sum"
+
+	local er_extroot_md5sum
+	if [ -f $md5sum_file ]; then
+		er_extroot_md5sum="$(cat $er_md5sum_file)"
+	fi
+
+	local er_extroot_overlay_md5sum
+	if [ -f "/overlay/etc/extroot.md5sum" ]; then
+		er_extroot_overlay_md5sum="$(cat /overlay/.extroot.md5sum)"
+	fi
+
+	if [ -z "$er_extroot_overlay_md5sum" ]; then
+		cat $er_md5sum_file >/overlay/.extroot.md5sum
+	elif [ "$er_extroot_overlay_md5sum" != "$er_extroot_md5sum" ]; then
+		pi_extroot_mount_success="false"
+		mkdir -p /tmp/overlay-disabled
+		mount --move /overlay /tmp/overlay-disabled
+	fi
+}
+
+set_jffs_md5sum() {
+	# We do this anytime block-extroot exists, even on the first boot with
+	# no extroot defined.
+
+	local er_md5sum_file
+	er_md5sum_file="${ER_OVERLAY_PREFIX}/.extroot.md5sum"
+
+	local er_extroot_md5sum
+	if [ -f $er_md5sum_file ]; then
+		er_extroot_md5sum="$(cat $er_md5sum_file)"
+	fi
+	if [ -z "$er_extroot_md5sum" ]; then
+		dd if=/dev/urandom count=32 bs=1k 2>/dev/null | md5sum | cut -f1 -d\  >$er_md5sum_file
+	fi
+}
+
+determine_extroot_sysupgrade() {
+	check_skip || set_jffs_md5sum
+
+	check_skip || [ "$pi_extroot_mount_success" != "true" ] || {
+		check_set_md5sum
+	}
+}
+
+boot_hook_add preinit_mount_root determine_extroot_sysupgrade
+