init/chromeos_shutdown - third_party/platform2 - Git at Google

 #!/bin/sh
 # Copyright 2013 The ChromiumOS Authors
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.

 # Some startup functions are split into a separate library which may be
 # different for different targets (e.g., regular Chrome OS vs. embedded).
 # shellcheck source=encrypted_stateful/startup_utils.sh
 . /usr/share/cros/startup_utils.sh

 # Shutdown is best-effort. We don't want to die on errors.
 set +e

 bootstat shutdown-start

 # Let's send output of this script through the kernel. This means that
 # we can see any relevant output after bootup in console-ramoops.
 # We'll also explicitly set `printk_devkmsg` to on which will prevent
 # rate-limiting.
 #
 # NOTE: this trick generally works more reliably with stderr than stdout.
 # Specifically writes to stdout may fail because programs may detect the
 # "/dev/kmsg" is a file and try to buffer output to stdout. If any individual
 # write is over the 1024 byte limit in the kernel then it will fail. We
 # expect most things we care about to be on stderr, but if an individual
 # program is getting a failure it could likely be handled by piping its
 # stdout to `sed -u -e ''`.
 sysctl -w kernel.printk_devkmsg=on
 exec 1> /dev/kmsg 2> /dev/kmsg

 # Set nologin so services (like usb_bouncer) can check that a shutdown is
 # happening.
 touch /run/nologin

 # Remount root in case a developer has remounted it rw for some reason.
 mount -n -o remount,ro /

 # TODO: swapoff as necessary.

 PROCESS_KILLER_LOG=/run/process_killer.log

 # Instruct upstart to not respawn jobs beyond this point in the shutdown process.
 initctl disable-respawn

 # Kill any that may prevent us from unmounting the stateful partition
 # or the crypto-home and then unmount. These should be all that we need
 # to unmount for a clean shutdown.
 #
 # We send the output of this script in two places: stdout (which is
 # redirected to /dev/kmsg) and "${PROCESS_KILLER_LOG}".
 #
 # Having ouptut in kmsg is useful because it captures the kills that
 # process_killer does even in the case that we don't have a catastrophic
 # unmount failure. We still care about these non-catastrophic cases because
 # processes _should_ have been killed before this script was even called (this
 # script is a last resort). Thus, having these logs show up in console-ramoops
 # is a good way to call attention to these kills.
 #
 # Another benefit of having process_killer logs in /dev/kmsg is that the
 # system is more likely than normal to crash at reboot/shutdown time as it
 # executes code that isn't exercised as much. Writing to /dev/kmsg shows up in
 # console-ramoops even if the kernel crashes partway through.
 #
 # Having process_killer logs in "${PROCESS_KILLER_LOG}" is also useful because,
 # if we do have an unmount failure, the output of process_killer is very
 # relevant and unmount failure crash reports don't include the kernel messages.
 process_killer --shutdown --log_to_stderr --file_holders \
   --mount_holders 2>&1 | tee "${PROCESS_KILLER_LOG}" | sed -u -e ""

 # CROS_DEBUG equals one if we've booted in developer mode or we've booted a
 # developer image.
 crossystem "cros_debug?1"
 CROS_DEBUG="$((! $?))"

 dev_unmount_packages() { true; }
 dev_push_paths_to_preserve() { true; }

 collect_shutdown_umount_failure_logs() {
   (
     # Get mount table as seen by this process. This list may not be
     # comprehensive: private mounts inside mount namespaces may not
     # appear in this list.
     echo "Active mounts:"
     cat "/proc/self/mountinfo"
     # Log information about the dm-crypt device.
     echo "Device-mapper target state:"
     dmsetup info -c -o name,open,attr
     # Log information about loop devices.
     # Helpful in debugging "bad" loopback devices that shouldn't exist. (e.g.
     # legacy DLC image associated loopback devices)
     echo "Loop devices:"
     losetup -a
     # Log upstart jobs that are either still running or tracking active
     # processes: jobs here can stop the stateful partition from getting
     # unmounted.
     echo "Active Upstart jobs:"
     initctl list | grep -e process -e running
     # Log dbus services still connected to the bus, with a 1 second timeout.
     echo "Active D-Bus services:"
     dbus-send --system --dest=org.freedesktop.DBus --type=method_call \
       --print-reply --reply-timeout=1000 /org/freedesktop/DBus \
       org.freedesktop.DBus.ListNames

     # Print process tree.
     echo "Process tree:"
     ps --deselect --ppid 2 --forest -f -o pid,ppid,state,comm
     # Parse pids of processes with active mount namespaces. PID is the fourth
     # field and the first line refers to the root mount namespace.
     for pid in $(lsns --raw -n -t mnt | cut -f4 -d' ' | tail -n+2); do
       echo "====== PID: ${pid} Comm: $(cat "/proc/${pid}/comm") ======"
       # Use findmnt to look inside the mount namespace for any mounts that
       # refer to the (enc)stateful partition. These mounts may keep the
       # stateful partition from unmounting cleanly.
       echo "Open mounts into (enc)stateful:"
       findmnt --raw -N "${pid}" | grep -e stateful -e mmcblk0p1 -e nvme0n1p1 \
         -e sda1
     done

     # Get a list of processes with files open. lsof is verbose: keep it at the
     # end of the log.
     echo "Processes with files open:"
     lsof -n /mnt/stateful_partition /var /home/chronos
     cat "${PROCESS_KILLER_LOG}"
   ) >/run/shutdown_umount_failure.log 2>&1
 }

 # Attempt multiple retries for each mount point. This prevents transient
 # failures from stopping the unmount process.
 umount_mountpoint() {
   local mnt="$1"
   # Check if the mount point exists.
   if ! mountpoint -q "${mnt}"; then
     return 0
   fi

   local rc=0
   for _ in 1 2 3 4 5 6 7 8 9 10; do
     umount -n "${mnt}"
     rc="$?"
     if [ "${rc}" -eq "0" ]; then
       break
     fi
     sleep 0.1
   done
   return "${rc}"
 }

 if [ "${CROS_DEBUG}" -eq 1 ]; then
   . /usr/share/cros/dev_utils.sh
 fi

 STATEFUL_PARTITION="/mnt/stateful_partition"
 STATEFUL_UPDATE="${STATEFUL_PARTITION}/.update_available"

 # target_version should only be created for test lab DUTs.
 TARGET_VERSION="/run/update_target_version"
 UPDATE_TARGET=""
 STATE_DEV=""

 if [ "${CROS_DEBUG}" = "1" ] && [ -f "${STATEFUL_UPDATE}" ]; then
   STATEFUL_UPDATE_ARGS="$(cat "${STATEFUL_UPDATE}")"

   if [ -r "${TARGET_VERSION}" ] && [ ! -L "${TARGET_VERSION}" ]; then
     # Used later to clear Quota parameters from stateful.
     UPDATE_TARGET="$(cut -d '.' -f 1 "${TARGET_VERSION}")"
     STATE_DEV="$(findmnt -n -o SOURCE -M "${STATEFUL_PARTITION}")"
     rm -f "${TARGET_VERSION}"
   fi

   if [ "${STATEFUL_UPDATE_ARGS}" = "clobber" ]; then
     PRESERVE_DIR="${STATEFUL_PARTITION}/unencrypted/preserve"

     # Measure shutdown time up to this point.
     bootstat before_preserve

     # We preserve a few files. Make sure preservation directory starts empty.
     rm -rf "${PRESERVE_DIR}/log"
     # shellcheck disable=SC2174
     mkdir -p -m 0755 "${PRESERVE_DIR}"
     cp -a "/var/log" "${PRESERVE_DIR}"
     dev_push_paths_to_preserve

     # We are about to put this into a directory that will shortly be wiped
     # out. Keep a timestamp where it will be preserved as well.
     PRESERVE_METRICS="${PRESERVE_DIR}/log/metrics"
     bootstat_archive \
       "${PRESERVE_METRICS}/shutdown.$(date --utc '+%Y%m%d%H%M%S')"
   fi
 fi

 # Signal that the clean shutdown point was reached (or at least as
 # close to that point as we can be before stateful is unmounted).
 # Log to stderr since syslog may not be available at this stage.
 crash_reporter --log_to_stderr --clean_shutdown

 # Flush buffers to disk to reflect this part of shutdown in the metrics.
 sync

 if [ -d /var/log ]; then
   # Remove old metrics since we only care about the last one.
   rm -rf /var/log/metrics/shutdown.*
   # Measure shutdown time up to this point.
   bootstat_archive "/var/log/metrics/shutdown.$(date --utc '+%Y%m%d%H%M%S')"
 fi

 # Preserves the rollback-prefixed content of pstore across one warm reboot.
 preserve_rollback_key() {
   local pmsg="/dev/pmsg0"
   local key f
   for f in /sys/fs/pstore/pmsg-ramoops-*; do
     # The glob may not match any file.
     [ -e "${f}" ] || continue

     # Ignore failures.
     key="$(grep "^rollback " "${f}")" || continue
     echo "${key}" >>"${pmsg}" || true

     # We've found a key. We're done.
     break
   done
 }

 # Preserve rollback key across firmware update reboot.
 # shellcheck disable=SC2154
 if [ "${SHUTDOWN_REASON}" = "firmware-update" ]; then
   preserve_rollback_key
 fi

 # To be safe, flush buffers to disk again before unmounting. (From
 # https://crbug.com/760007 it seems that a failed umount can get the filesystem
 # into a state that renders a subsequent sync ineffective.)
 sync

 # Log all the unmount logic to a temp file and move it over to stateful if any
 # of the steps failed.
 (
 set -x

 # Unmount stateful partition for dev packages. Will be a NOP unless we're in
 # dev mode.
 dev_unmount_packages

 # Unmount /var/run and /var/lock, which were bind mounted to /run and /run/lock
 # respectively to enable backwards compatibility for accessing /run (tmpfs for
 # runtime data) through /var.
 umount_mountpoint "/var/run"
 umount_mountpoint "/var/lock"

 # Unmount /var, /home and encrypted mountpoints, then try to
 # unmount /mnt/stateful_partition.  Log to /mnt/stateful_partition if any of
 # them failed to unmount.
 # Note that the other mounts are submounts of /mnt/stateful_partition on
 # regular images, but not always true on factory images.  To handle both, we
 # should unmount /mnt/stateful_partition only if the others successfully
 # unmounted, otherwise system may fail to log.  See crbug.com/835557.
 umount_var_and_home_chronos
 rc="$?"

 # Check if /home is mounted before attempting to umount().
 umount_mountpoint "/home"
 : "$(( rc |= $? ))"

 # Unmount /mnt/stateful_partition only if the previous unmounts succeeded.
 if [ "${rc}" -eq 0 ]; then
   umount_mountpoint "${STATEFUL_PARTITION}"
 fi
 exit "$(( rc | $? ))"
 ) >/run/mount_encrypted/umount-encrypted.log 2>&1

 # shellcheck disable=SC2181
 if [ "$?" -ne 0 ]; then
   # Collect information about active mount namespaces and if there are bind
   # mounts open inside these namespaces into the (enc)stateful partition.
   collect_shutdown_umount_failure_logs
   crash_reporter --early --log_to_stderr --umount_failure \
     --mount_device="stateful"
   crash_reporter --early --log_to_stderr --preserve_across_clobber \
     --ephemeral_collect
   mv /run/mount_encrypted/umount-encrypted.log "${STATEFUL_PARTITION}/"
   mv /run/shutdown_umount_failure.log "${STATEFUL_PARTITION}/"
 else
   if [ -n "${UPDATE_TARGET}" ] && [ -n "${STATE_DEV}" ]; then
     # 10756.0.0 is the first build to turn on ext4 quota.
     # See https://crrev.com/c/1016226
     # Older builds will fail to mount stateful if quota is enabled.
     # This code can be removed when we stop testing pre-R69 FSI updates.
     if [ "${UPDATE_TARGET}" -lt 10756 ]; then
       if dumpe2fs -h "${STATE_DEV}" 2>/dev/null | \
                 grep -qe "^Filesystem features:.* quota.*"; then
         tune2fs -O^quota -Q^usrquota,^grpquota,^prjquota "${STATE_DEV}"
       fi
     fi
   fi
   rm -f /run/mount_encrypted/umount-encrypted.log
 fi

 # Just in case something didn't unmount properly above.
 sync

 # Display low battery icon if shutting down due to low battery.
 # SHUTDOWN_REASON is passed in with the runlevel event from power manager.
 # shellcheck disable=SC2154
 if [ "${SHUTDOWN_REASON}" = "low-battery" ]; then
   display_low_battery_alert
 fi

 # Ensure that we always claim success.
 exit 0
	#!/bin/sh
	# Copyright 2013 The ChromiumOS Authors
	# Use of this source code is governed by a BSD-style license that can be
	# found in the LICENSE file.

	# Some startup functions are split into a separate library which may be
	# different for different targets (e.g., regular Chrome OS vs. embedded).
	# shellcheck source=encrypted_stateful/startup_utils.sh
	. /usr/share/cros/startup_utils.sh

	# Shutdown is best-effort. We don't want to die on errors.
	set +e

	bootstat shutdown-start

	# Let's send output of this script through the kernel. This means that
	# we can see any relevant output after bootup in console-ramoops.
	# We'll also explicitly set `printk_devkmsg` to on which will prevent
	# rate-limiting.
	#
	# NOTE: this trick generally works more reliably with stderr than stdout.
	# Specifically writes to stdout may fail because programs may detect the
	# "/dev/kmsg" is a file and try to buffer output to stdout. If any individual
	# write is over the 1024 byte limit in the kernel then it will fail. We
	# expect most things we care about to be on stderr, but if an individual
	# program is getting a failure it could likely be handled by piping its
	# stdout to `sed -u -e ''`.
	sysctl -w kernel.printk_devkmsg=on
	exec 1> /dev/kmsg 2> /dev/kmsg

	# Set nologin so services (like usb_bouncer) can check that a shutdown is
	# happening.
	touch /run/nologin

	# Remount root in case a developer has remounted it rw for some reason.
	mount -n -o remount,ro /

	# TODO: swapoff as necessary.

	PROCESS_KILLER_LOG=/run/process_killer.log

	# Instruct upstart to not respawn jobs beyond this point in the shutdown process.
	initctl disable-respawn

	# Kill any that may prevent us from unmounting the stateful partition
	# or the crypto-home and then unmount. These should be all that we need
	# to unmount for a clean shutdown.
	#
	# We send the output of this script in two places: stdout (which is
	# redirected to /dev/kmsg) and "${PROCESS_KILLER_LOG}".
	#
	# Having ouptut in kmsg is useful because it captures the kills that
	# process_killer does even in the case that we don't have a catastrophic
	# unmount failure. We still care about these non-catastrophic cases because
	# processes _should_ have been killed before this script was even called (this
	# script is a last resort). Thus, having these logs show up in console-ramoops
	# is a good way to call attention to these kills.
	#
	# Another benefit of having process_killer logs in /dev/kmsg is that the
	# system is more likely than normal to crash at reboot/shutdown time as it
	# executes code that isn't exercised as much. Writing to /dev/kmsg shows up in
	# console-ramoops even if the kernel crashes partway through.
	#
	# Having process_killer logs in "${PROCESS_KILLER_LOG}" is also useful because,
	# if we do have an unmount failure, the output of process_killer is very
	# relevant and unmount failure crash reports don't include the kernel messages.
	process_killer --shutdown --log_to_stderr --file_holders \
	--mount_holders 2>&1 \| tee "${PROCESS_KILLER_LOG}" \| sed -u -e ""

	# CROS_DEBUG equals one if we've booted in developer mode or we've booted a
	# developer image.
	crossystem "cros_debug?1"
	CROS_DEBUG="$((! $?))"

	dev_unmount_packages() { true; }
	dev_push_paths_to_preserve() { true; }

	collect_shutdown_umount_failure_logs() {
	(
	# Get mount table as seen by this process. This list may not be
	# comprehensive: private mounts inside mount namespaces may not
	# appear in this list.
	echo "Active mounts:"
	cat "/proc/self/mountinfo"
	# Log information about the dm-crypt device.
	echo "Device-mapper target state:"
	dmsetup info -c -o name,open,attr
	# Log information about loop devices.
	# Helpful in debugging "bad" loopback devices that shouldn't exist. (e.g.
	# legacy DLC image associated loopback devices)
	echo "Loop devices:"
	losetup -a
	# Log upstart jobs that are either still running or tracking active
	# processes: jobs here can stop the stateful partition from getting
	# unmounted.
	echo "Active Upstart jobs:"
	initctl list \| grep -e process -e running
	# Log dbus services still connected to the bus, with a 1 second timeout.
	echo "Active D-Bus services:"
	dbus-send --system --dest=org.freedesktop.DBus --type=method_call \
	--print-reply --reply-timeout=1000 /org/freedesktop/DBus \
	org.freedesktop.DBus.ListNames

	# Print process tree.
	echo "Process tree:"
	ps --deselect --ppid 2 --forest -f -o pid,ppid,state,comm
	# Parse pids of processes with active mount namespaces. PID is the fourth
	# field and the first line refers to the root mount namespace.
	for pid in $(lsns --raw -n -t mnt \| cut -f4 -d' ' \| tail -n+2); do
	echo "====== PID: ${pid} Comm: $(cat "/proc/${pid}/comm") ======"
	# Use findmnt to look inside the mount namespace for any mounts that
	# refer to the (enc)stateful partition. These mounts may keep the
	# stateful partition from unmounting cleanly.
	echo "Open mounts into (enc)stateful:"
	findmnt --raw -N "${pid}" \| grep -e stateful -e mmcblk0p1 -e nvme0n1p1 \
	-e sda1
	done

	# Get a list of processes with files open. lsof is verbose: keep it at the
	# end of the log.
	echo "Processes with files open:"
	lsof -n /mnt/stateful_partition /var /home/chronos
	cat "${PROCESS_KILLER_LOG}"
	) >/run/shutdown_umount_failure.log 2>&1
	}

	# Attempt multiple retries for each mount point. This prevents transient
	# failures from stopping the unmount process.
	umount_mountpoint() {
	local mnt="$1"
	# Check if the mount point exists.
	if ! mountpoint -q "${mnt}"; then
	return 0
	fi

	local rc=0
	for _ in 1 2 3 4 5 6 7 8 9 10; do
	umount -n "${mnt}"
	rc="$?"
	if [ "${rc}" -eq "0" ]; then
	break
	fi
	sleep 0.1
	done
	return "${rc}"
	}

	if [ "${CROS_DEBUG}" -eq 1 ]; then
	. /usr/share/cros/dev_utils.sh
	fi

	STATEFUL_PARTITION="/mnt/stateful_partition"
	STATEFUL_UPDATE="${STATEFUL_PARTITION}/.update_available"

	# target_version should only be created for test lab DUTs.
	TARGET_VERSION="/run/update_target_version"
	UPDATE_TARGET=""
	STATE_DEV=""

	if [ "${CROS_DEBUG}" = "1" ] && [ -f "${STATEFUL_UPDATE}" ]; then
	STATEFUL_UPDATE_ARGS="$(cat "${STATEFUL_UPDATE}")"

	if [ -r "${TARGET_VERSION}" ] && [ ! -L "${TARGET_VERSION}" ]; then
	# Used later to clear Quota parameters from stateful.
	UPDATE_TARGET="$(cut -d '.' -f 1 "${TARGET_VERSION}")"
	STATE_DEV="$(findmnt -n -o SOURCE -M "${STATEFUL_PARTITION}")"
	rm -f "${TARGET_VERSION}"
	fi

	if [ "${STATEFUL_UPDATE_ARGS}" = "clobber" ]; then
	PRESERVE_DIR="${STATEFUL_PARTITION}/unencrypted/preserve"

	# Measure shutdown time up to this point.
	bootstat before_preserve

	# We preserve a few files. Make sure preservation directory starts empty.
	rm -rf "${PRESERVE_DIR}/log"
	# shellcheck disable=SC2174
	mkdir -p -m 0755 "${PRESERVE_DIR}"
	cp -a "/var/log" "${PRESERVE_DIR}"
	dev_push_paths_to_preserve

	# We are about to put this into a directory that will shortly be wiped
	# out. Keep a timestamp where it will be preserved as well.
	PRESERVE_METRICS="${PRESERVE_DIR}/log/metrics"
	bootstat_archive \
	"${PRESERVE_METRICS}/shutdown.$(date --utc '+%Y%m%d%H%M%S')"
	fi
	fi

	# Signal that the clean shutdown point was reached (or at least as
	# close to that point as we can be before stateful is unmounted).
	# Log to stderr since syslog may not be available at this stage.
	crash_reporter --log_to_stderr --clean_shutdown

	# Flush buffers to disk to reflect this part of shutdown in the metrics.
	sync

	if [ -d /var/log ]; then
	# Remove old metrics since we only care about the last one.
	rm -rf /var/log/metrics/shutdown.*
	# Measure shutdown time up to this point.
	bootstat_archive "/var/log/metrics/shutdown.$(date --utc '+%Y%m%d%H%M%S')"
	fi

	# Preserves the rollback-prefixed content of pstore across one warm reboot.
	preserve_rollback_key() {
	local pmsg="/dev/pmsg0"
	local key f
	for f in /sys/fs/pstore/pmsg-ramoops-*; do
	# The glob may not match any file.
	[ -e "${f}" ] \|\| continue

	# Ignore failures.
	key="$(grep "^rollback " "${f}")" \|\| continue
	echo "${key}" >>"${pmsg}" \|\| true

	# We've found a key. We're done.
	break
	done
	}

	# Preserve rollback key across firmware update reboot.
	# shellcheck disable=SC2154
	if [ "${SHUTDOWN_REASON}" = "firmware-update" ]; then
	preserve_rollback_key
	fi

	# To be safe, flush buffers to disk again before unmounting. (From
	# https://crbug.com/760007 it seems that a failed umount can get the filesystem
	# into a state that renders a subsequent sync ineffective.)
	sync

	# Log all the unmount logic to a temp file and move it over to stateful if any
	# of the steps failed.
	(
	set -x

	# Unmount stateful partition for dev packages. Will be a NOP unless we're in
	# dev mode.
	dev_unmount_packages

	# Unmount /var/run and /var/lock, which were bind mounted to /run and /run/lock
	# respectively to enable backwards compatibility for accessing /run (tmpfs for
	# runtime data) through /var.
	umount_mountpoint "/var/run"
	umount_mountpoint "/var/lock"

	# Unmount /var, /home and encrypted mountpoints, then try to
	# unmount /mnt/stateful_partition. Log to /mnt/stateful_partition if any of
	# them failed to unmount.
	# Note that the other mounts are submounts of /mnt/stateful_partition on
	# regular images, but not always true on factory images. To handle both, we
	# should unmount /mnt/stateful_partition only if the others successfully
	# unmounted, otherwise system may fail to log. See crbug.com/835557.
	umount_var_and_home_chronos
	rc="$?"

	# Check if /home is mounted before attempting to umount().
	umount_mountpoint "/home"
	: "$(( rc \|= $? ))"

	# Unmount /mnt/stateful_partition only if the previous unmounts succeeded.
	if [ "${rc}" -eq 0 ]; then
	umount_mountpoint "${STATEFUL_PARTITION}"
	fi
	exit "$(( rc \| $? ))"
	) >/run/mount_encrypted/umount-encrypted.log 2>&1

	# shellcheck disable=SC2181
	if [ "$?" -ne 0 ]; then
	# Collect information about active mount namespaces and if there are bind
	# mounts open inside these namespaces into the (enc)stateful partition.
	collect_shutdown_umount_failure_logs
	crash_reporter --early --log_to_stderr --umount_failure \
	--mount_device="stateful"
	crash_reporter --early --log_to_stderr --preserve_across_clobber \
	--ephemeral_collect
	mv /run/mount_encrypted/umount-encrypted.log "${STATEFUL_PARTITION}/"
	mv /run/shutdown_umount_failure.log "${STATEFUL_PARTITION}/"
	else
	if [ -n "${UPDATE_TARGET}" ] && [ -n "${STATE_DEV}" ]; then
	# 10756.0.0 is the first build to turn on ext4 quota.
	# See https://crrev.com/c/1016226
	# Older builds will fail to mount stateful if quota is enabled.
	# This code can be removed when we stop testing pre-R69 FSI updates.
	if [ "${UPDATE_TARGET}" -lt 10756 ]; then
	if dumpe2fs -h "${STATE_DEV}" 2>/dev/null \| \
	grep -qe "^Filesystem features:.* quota.*"; then
	tune2fs -O^quota -Q^usrquota,^grpquota,^prjquota "${STATE_DEV}"
	fi
	fi
	fi
	rm -f /run/mount_encrypted/umount-encrypted.log
	fi

	# Just in case something didn't unmount properly above.
	sync

	# Display low battery icon if shutting down due to low battery.
	# SHUTDOWN_REASON is passed in with the runlevel event from power manager.
	# shellcheck disable=SC2154
	if [ "${SHUTDOWN_REASON}" = "low-battery" ]; then
	display_low_battery_alert
	fi

	# Ensure that we always claim success.
	exit 0