image_to_live verifies root_dev changed

image_to_live.sh

 #!/bin/bash
 
 # Copyright (c) 2009-2010 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Script to update an image onto a live running ChromiumOS instance.
 
 # Load common constants.  This should be the first executable line.
 # The path to common.sh should be relative to your script's location.
@@ skipping 311 matching lines @@
 
   if [ "${lsb_release}" = "${REMOTE_OUT}" ]; then
     info "Update was successful and image verified as ${lsb_release}."
     return 0
   else
     warn "Image verification failed."
     return 1
   fi
 }
 
+function find_root_dev {
+  remote_sh "rootdev -s"
+  echo ${REMOTE_OUT}
+}
+
 function main() {
   assert_outside_chroot
 
   cd $(dirname "$0")
 
   FLAGS "$@" || exit 1
   eval set -- "${FLAGS_ARGV}"
 
   set -e
 
   if [ ${FLAGS_verify} -eq ${FLAGS_TRUE} ] && \
       [ -n "${FLAGS_update_url}" ]; then
     warn "Verify is not compatible with setting an update url."
     FLAGS_verify=${FLAGS_FALSE}
   fi
 
   trap cleanup EXIT
 
   TMP=$(mktemp -d /tmp/image_to_live.XXXX)
 
   remote_access_init
 
   if [ "$(get_update_var CURRENT_OP)" != "${UPDATER_IDLE}" ]; then
     warn "Machine is in a bad state.  Rebooting it now."
     remote_reboot
   fi
 
+  local initial_root_dev=$(find_root_dev)
+
   if [ -z "${FLAGS_update_url}" ]; then
     # Start local devserver if no update url specified.
     start_dev_server
   fi
 
   if [ ${FLAGS_update} -eq ${FLAGS_TRUE} ] && ! run_auto_update; then
     warn "Dumping update_engine.log for debugging and/or bug reporting."
     tail -n 200 "${FLAGS_update_log}" >&2
     die "Update was not successful."
   fi
@@ skipping 10 matching lines @@
     cp "${known_hosts}" "${known_hosts}~"
     grep -v "^${FLAGS_remote} " "${known_hosts}" > "${TMP}/new_known_hosts"
     cat "${TMP}/new_known_hosts" "${TMP_KNOWN_HOSTS}" > "${known_hosts}"
     chmod 0640 "${known_hosts}"
     info "New updated in ${known_hosts}, backup made."
   fi
 
   remote_sh "grep ^CHROMEOS_RELEASE_DESCRIPTION= /etc/lsb-release"
   if [ ${FLAGS_verify} -eq ${FLAGS_TRUE} ]; then
     verify_image
+
+    if [ "${initial_root_dev}" == "$(find_root_dev)" ]; then
+      # At this point, the software version didn't change, but we didn't
+      # switch partitions either. Means it was an update to the same version
+      # that failed.
+      die "The root partition did NOT change. The update failed."
+    fi
   else
     local release_description=$(echo ${REMOTE_OUT} | cut -d '=' -f 2)
     info "Update was successful and rebooted to $release_description"
   fi
 
   print_time_elapsed
 
   exit 0
 }
 
 main $@