vzreboot

#! /bin/bash
#  Copyright (c) 2012-2017, Parallels International GmbH. All rights reserved.
# Copyright (c) 2017-2019 Virtuozzo International GmbH. All rights reserved.
#
#  This file is part of OpenVZ. OpenVZ is free software; you can redistribute
#  it and/or modify it under the terms of the GNU General Public License as
#  published by the Free Software Foundation; either version 2 of the License,
#  or (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful, but
#  WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
#  General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software
#  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
#  02110-1301, USA.
#
#  Our contact details: Virtuozzo International GmbH, Vordergasse 59, 8200
#  Schaffhausen, Switzerland.

KERNEL=
LOCKFILE=/dev/shm/vzreboot.lck
FILE_LIST=/tmp/ct_file.lst
PRECACHE_LOOKUP=/usr/libexec/vzprecache_lookup
USE_PREALLOC=yes
USE_PRECACHE=yes
USE_REBOOT=yes

usage()
{
	echo "Usage: $(basename "${0}") [kernel]"
	exit 0
}

parse_args()
{
while [ "${#}" -gt 0 ]; do
	case "${1}" in
		"-h" | "--help")
		usage
		shift
		;;
		"--noprealloc")
		USE_PREALLOC=no
		shift
		;;
		"--noprecache")
		USE_PRECACHE=no
		shift
		;;
		"--noreboot")
		USE_REBOOT=no
		shift
		;;
		*)
		[ -n "$KERNEL" ] && usage
		KERNEL=$1
		KERNEL_PATH="/boot/vmlinuz-${KERNEL}"
		if [ ! -f "${KERNEL_PATH}" ]; then
			echo "Incorrect kernel version: $1"
			exit 1
		fi
		shift
		;;
	esac
done
}

get_open_files()
{
	ls -l /proc/$1/fd 2>/dev/null; cat /proc/$1/maps 2>/dev/null
}

get_mount_by_dev()
{
	awk '( "'$1'" == $1 ) { print $2; exit 0}' /proc/mounts
}

do_prealloc()
{
	local banned_mem=`cat /sys/kernel/pram_banned`
	local total_mem=`grep -m1 MemTotal /proc/meminfo | awk '{print $2/4}'`
	local prealloc_mem=$[banned_mem+total_mem/200]
	echo -n "Preallocating $prealloc_mem pages for PRAM... "
	echo $prealloc_mem > /sys/kernel/pram_prealloc 2>/dev/null && \
		echo "DONE" || echo -e "FAILED\nProceeding without prealloc (may be slower)"
}

do_precache()
{
	local veid dev mnt pid

	echo -n "Precache CTs: "
	for veid in $(vzlist -Ho veid 2>/dev/null); do
		echo -n "$veid "

		dev=$(vzlist -Ho device $veid)
		[ -z "$dev" ] && continue
		mnt=$(get_mount_by_dev $dev)
		[ -z "$mnt" ] && continue

		rm -f $FILE_LIST 2>/dev/null
		for pid in `vzps axh -opid -E $veid 2>/dev/null`; do
			get_open_files $pid | \
				awk -F ' /' '{print substr($2, length("'$mnt'"));}' >> $FILE_LIST
		done
		cat "$FILE_LIST" | sort -u | $PRECACHE_LOOKUP $dev 2>/dev/null
	done
	echo
}

set_pramcache_features()
{
	local config=/boot/config-${KERNEL}

	if [ ! -r "${config}" ]; then
		echo "Cannot read $config"
		return
	fi

	awk -F= '/CONFIG_PRAMCACHE_FEATURE_/ {
        	feature=$1
	        gsub("CONFIG_PRAMCACHE_FEATURE_", "", feature)
        	fname="/proc/sys/fs/pramcache/" tolower(feature)
	        if (system("test -w " fname) == 0)
        	        print $2 > fname
	}' ${config} 
}

run_kexec()
{
	local initrd low_mem append root args addr

	if [ -z "${KERNEL}" ]; then
		KERNEL_PATH=`grubby --default-kernel`
		KERNEL=`echo "$KERNEL_PATH" | sed -e "s/[^-]*-\(.*\)/\1/g"`
	fi

	if ! lockfile -r 0 $LOCKFILE > /dev/null 2>&1 ; then
		echo "vzreboot in progress..."
		exit 1
	fi

	set_pramcache_features

	initrd="/boot/initramfs-${KERNEL}.img"
	test -f $initrd || initrd="/boot/initrd-${KERNEL}.img"

	low_mem=`cat /sys/kernel/pram_low`

	# read configured kernel boot args
	append=`grubby --info=${KERNEL_PATH}`
	if [ $? -eq 0 ]; then
		root=`echo "$append" | grep '^root='`
		args=`echo "$append" | \
			sed -n -e 's/^args=\"\(.*\)\( pram=[^ ]*\)\?\(.*\)\"/\1\3/p'`
		append="$args $root"
	else
		# fail to get configured kernel args, will use running ones
		append=`cat /proc/cmdline | sed -e 's/ pram=[^ ]*//g'`
	fi
	append="${append} pram=$(cat /sys/kernel/pram)"
	if [ -f /sys/firmware/efi/systab ]; then
		if grep -q '^ACPI20=' /sys/firmware/efi/systab;	then
			addr=$(awk -F'=' '/^ACPI20=/ {print $2}' /sys/firmware/efi/systab)
		else
			addr=$(awk -F'=' '/^ACPI=/ {print $2}' /sys/firmware/efi/systab)
		fi
		append="$append noefi acpi_rsdp=$addr"
	fi

	[ "$USE_PREALLOC" = "yes" ] && do_prealloc
	[ "$USE_PRECACHE" = "yes" ] && do_precache

	# Check for pram_low is enough (128Mb)
	PRAM_LOW=`cat /sys/kernel/pram_low`
	if [ $PRAM_LOW -lt 134217728 ]; then
		echo "The new kernel might fail to load due to too low memory that is reserved for"
		echo "it by the 'pram_low' parameter specified in the kernel command line. Make"
		echo "sure that the 'pram_low' parameter is set correctly in the kernel command"
		echo "line (recommended: pram_low=128M)."
	fi

	echo "Booting to the $KERNEL"
	# The '--unload --load' is trick to skip sync()
	kexec --unload --load "/boot/vmlinuz-${KERNEL}" --initrd="${initrd}" --append="$append" --mem-max="$low_mem" >/dev/null
	if [ $? -ne 0 ]; then
		echo 0 > /sys/kernel/pram_prealloc 2>/dev/null
		rm -f $LOCKFILE
		echo "kexec failed" >&2
		exit 1
	fi

	if [ "$USE_REBOOT" = "no" ]; then
		rm -f $LOCKFILE
		return
	fi
	/sbin/reboot
	if [ $? -ne 0 ]; then
		echo 0 > /sys/kernel/pram_prealloc 2>/dev/null
		rm -f $LOCKFILE
		echo "reboot failed" >&2
		exit 1
	fi
}

parse_args "${@}"

if [ $(id -u) -ne 0 ]; then
    echo "Insufficient privileges"
    exit 1
fi

mes=`vzlicview`
if [ $? -ne 0 ]; then
	echo "Unable to get license info."
	exit 1
fi

if ! echo "$mes" | grep -q 'rku_allowed=1'; then
    echo "Your license does not support using the vzreboot utility."
    exit 1
fi

run_kexec