| #!/bin/sh |
| # Copyright 2015 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. |
| |
| if ! mountpoint -q /etc; then |
| ETC=/tmp/etc_overlay |
| mkdir ${ETC} |
| if mount -t tmpfs tmpfs ${ETC} -o mode=755,nosuid,noexec,nodev ; then |
| mkdir -p ${ETC}/etc ${ETC}/.work |
| # Because /etc is read-only at the time systemd boots, |
| # systemd saves machine-id in /run and then bind-mounts it |
| # into /etc. A few services depend on /etc/machine-id, so we want |
| # to make sure that there is no downtime on /etc/machine-id. Let's |
| # keep the /etc/machine-id bind mount to make sure there is no downtime. |
| # We also need to copy /etc/machine-id into the overlayfs upperdir before |
| # mounting it to ensure no downtime after mounting the overlayfs. |
| cp /run/machine-id "${ETC}/etc/machine-id" |
| mount -o lowerdir=/etc,upperdir=${ETC}/etc,workdir=${ETC}/.work \ |
| -t overlay overlayfs /etc || |
| logger -t "$UPSTART_JOB" \ |
| "Cannot mount /etc overlay" |
| umount ${ETC} |
| rmdir ${ETC} |
| else |
| logger -t "$UPSTART_JOB" "Cannot mount tmpfs at ${ETC}" |
| fi |
| fi |
