S05checkroot.sh

#! /bin/sh
### BEGIN INIT INFO
# Provides:          checkroot mtab
# Required-Start:    mountdevsubfs hostname
# Required-Stop:     
# Should-Start:      keymap hwclockfirst hdparm bootlogd
# Should-stop:
# Default-Start:     S
# Default-Stop:
# X-Interactive:     true
# Short-Description: Check to root file system.
### END INIT INFO

# Include /usr/bin in path to find on_ac_power if /usr/ is on the root
# partition.
PATH=/sbin:/bin:/usr/bin
FSCK_LOGFILE=/var/log/fsck/checkroot
[ "$FSCKFIX" ] || FSCKFIX=no
[ "$SULOGIN" ] || SULOGIN=no
. /lib/init/vars.sh

. /lib/lsb/init-functions
. /lib/init/mount-functions.sh

do_start () {
	# Trap SIGINT so that we can handle user interrupt of fsck.
	trap "" INT

	#
	# Set SULOGIN in /etc/default/rcS to yes if you want a sulogin to
	# be spawned from this script *before anything else* with a timeout,
	# like sysv does.
	#
	[ "$SULOGIN" = yes ] && sulogin -t 30 $CONSOLE

	KERNEL="$(uname -s)"
	MACHINE="$(uname -m)"

	read_fstab

	#
	# Activate the swap device(s) in /etc/fstab. This needs to be done
	# before fsck, since fsck can be quite memory-hungry.
	#
	ENABLE_SWAP=no
	case "$KERNEL" in
	  Linux)
	  	if [ "$NOSWAP" = yes ]
		then
			[ "$VERBOSE" = no ] || log_warning_msg "Not activating swap as requested via bootoption noswap."
			ENABLE_SWAP=no
		else
			if [ "$swap_on_lv" = yes ]
			then
				[ "$VERBOSE" = no ] || log_warning_msg "Not activating swap on logical volume."
			elif [ "$swap_on_file" = yes ]
			then
				[ "$VERBOSE" = no ] || log_warning_msg "Not activating swap on swapfile."
			else
				ENABLE_SWAP=yes
			fi
		fi
		;;
	  *)
		ENABLE_SWAP=yes
		;;
	esac
	if [ "$ENABLE_SWAP" = yes ]
	then
		if [ "$VERBOSE" = no ]
		then
			log_action_begin_msg "Activating swap"
			swapon -a -e >/dev/null 2>&1
			log_action_end_msg $?
		else
			log_daemon_msg "Activating swap"
			swapon -a -v
			log_end_msg $?
		fi
	fi

	#
	# Does the root device in /etc/fstab match with the actual device ?
	# If not we try to use the /dev/root alias device, and if that
	# fails we create a temporary node in /run.
	#
	# Do this only on Linux. Neither kFreeBSD nor Hurd have
	# /dev/root and the device ids used here are specific to
	# Linux.
	KERNEL="$(uname)"
	if [ "$rootcheck" = yes ] && [ "$KERNEL" = Linux ]
	then
		ddev="$(mountpoint -qx $rootdev)"
		rdev="$(mountpoint -d /)"
		if [ "$ddev" != "$rdev" ] && [ "$ddev" != "4:0" ]
		then
			if [ "$(mountpoint -qx /dev/root)" = "4:0" ]
			then
				rootdev=/dev/root
			else
				if \
					rm -f /run/rootdev \
					&& mknod -m 600 /run/rootdev b ${rdev%:*} ${rdev#*:} \
					&& [ -e /run/rootdev ]
				then
					rootdev=/run/rootdev
				else
					rootfatal=yes
				fi
			fi
		fi
	fi

	#
	# Bother, said Pooh.
	#
	if [ "$rootfatal" = yes ]
	then
		log_failure_msg "The device node $rootdev for the root filesystem is missing or incorrect 
or there is no entry for the root filesystem listed in /etc/fstab. 
The system is also unable to create a temporary node in /run. 
This means you have to fix the problem manually."
		log_warning_msg "A maintenance shell will now be started. 
CONTROL-D will terminate this shell and restart the system."
		# Start a single user shell on the console
		if ! sulogin $CONSOLE
		then
			log_failure_msg "Attempt to start maintenance shell failed. 
Will restart in 5 seconds."
			sleep 5
		fi
		[ "$VERBOSE" = no ] || log_action_msg "Will now restart"
		reboot -f
	fi

	# See if we're on AC Power.  If not, we're not gonna run our
	# check.  If on_ac_power (in /usr/) is unavailable, behave as
	# before and check all file systems needing it.
# Disabled AC power check until fsck can be told to only check the
# file system if it is corrupt when running on battery. (bug #526398)
#	if which on_ac_power >/dev/null 2>&1 && [ "$rootcheck" = yes ]
#	then
#		on_ac_power >/dev/null 2>&1
#		if [ "$?" -eq 1 ]
#		then
#			log_warning_msg "On battery power, so skipping file system check."
#			rootcheck=no
#		fi
#	fi

	#
	# See if we want to check the root file system.
	#
	FSCKCODE=0
	if is_fastboot_active
	then
		[ "$rootcheck" = yes ] && log_warning_msg "Fast boot enabled, so skipping root file system check."
		rootcheck=no
	fi

	if which findmnt >/dev/null 2>&1
	then
		if [ "$(findmnt -f -n -o FSTYPE /)" = "btrfs" ]
		then
			[ "$rootcheck" = yes ] && log_warning_msg "btrfs root detected, so skipping root file system check."
			rootcheck=no
		fi
	fi

	if [ "$rootcheck" = yes ]
	then
		#
		# Ensure that root is quiescent and read-only before fsck'ing.
		#
		# mount -n -o remount,ro / would be the correct syntax but
		# mount can get confused when there is a "bind" mount defined
		# in fstab that bind-mounts "/" somewhere else.
		#
		# So we use mount -n -o remount,ro $rootdev / but that can
		# fail on older kernels on sparc64/alpha architectures due
		# to a bug in sys_mount().
		#
		# As a compromise we try both.
		#
		if \
			! mount    -n -o remount,ro              $rootdev /              \
			&& ! mount -n -o remount,ro -t dummytype $rootdev /  2>/dev/null \
			&& ! mount -n -o remount,ro                       /  2>/dev/null
		then
			log_failure_msg "Cannot check root file system because it is not mounted read-only."
			rootcheck=no
		fi
	fi

	#
	# The actual checking is done here.
	#
	if [ "$rootcheck" = yes ]
	then
		if [ -f /forcefsck ] || grep -q -s -w -i "forcefsck" /proc/cmdline
		then
			force="-f"
		else
			force=""
		fi

		if [ "$FSCKFIX" = yes ]
		then
			fix="-y"
		else
			fix="-a"
		fi

		spinner="-C"
		case "$TERM" in
		  dumb|network|unknown|"")
			spinner="" ;;
		esac
		# This Linux/s390x special case should go away.
		if [ "${KERNEL}:${MACHINE}" = Linux:s390x ]
		then
			spinner=""
		fi
		
		if [ "$VERBOSE" = no ]
		then
			log_action_begin_msg "Checking root file system"
			logsave -s $FSCK_LOGFILE fsck $spinner $force $fix -t $roottype $rootdev
			FSCKCODE=$?
			if [ "$FSCKCODE" = 0 ]
			then
				log_action_end_msg 0
			else
				log_action_end_msg 1 "code $FSCKCODE"
			fi
		else
			log_daemon_msg "Will now check root file system"
			logsave -s $FSCK_LOGFILE fsck $spinner $force $fix -V -t $roottype $rootdev
			FSCKCODE=$?
			log_end_msg $FSCKCODE
		fi
	fi

	#
	# If there was a failure, drop into single-user mode.
	#
	# NOTE: "failure" is defined as exiting with a return code of
	# 4 or larger. A return code of 1 indicates that file system
	# errors were corrected but that the boot may proceed. A return
	# code of 2 or 3 indicates that the system should immediately reboot.
	#
	if [ "$FSCKCODE" -eq 32 ]
	then
		log_warning_msg "File system check was interrupted by user"
	elif [ "$FSCKCODE" -gt 3 ]
	then
		# Surprise! Re-directing from a HERE document (as in "cat << EOF")
		# does not work because the root is currently read-only.
		log_failure_msg "An automatic file system check (fsck) of the root filesystem failed. 
A manual fsck must be performed, then the system restarted. 
The fsck should be performed in maintenance mode with the 
root filesystem mounted in read-only mode."
		log_warning_msg "The root filesystem is currently mounted in read-only mode. 
A maintenance shell will now be started. 
After performing system maintenance, press CONTROL-D 
to terminate the maintenance shell and restart the system."
		# Start a single user shell on the console
		if ! sulogin $CONSOLE
		then
			log_failure_msg "Attempt to start maintenance shell failed. 
Will restart in 5 seconds."
			sleep 5
		fi
		[ "$VERBOSE" = no ] || log_action_msg "Will now restart"
		reboot -f
	elif [ "$FSCKCODE" -gt 1 ]
	then
		log_failure_msg "The file system check corrected errors on the root partition 
but requested that the system be restarted."
		log_warning_msg "The system will be restarted in 5 seconds."
		sleep 5
		[ "$VERBOSE" = no ] || log_action_msg "Will now restart"
		reboot -f
	fi

	#
	# Remount root to final mode (rw or ro).
	#
	# See the comments above at the previous "mount -o remount"
	# for an explanation why we try this twice.
	#
	if ! mount -n -o remount,$rootopts,$rootmode $fstabroot / 2>/dev/null
	then
		mount -n -o remount,$rootopts,$rootmode /
	fi

	# If possible, migrate /etc/mtab to be a symlink to
	# /proc/mounts.  Note that not all systems e.g. Hurd currently
	# support this.
	if [ "$rootmode" != "ro" ]; then
		mtab_migrate
	fi

	if selinux_enabled && [ -x /sbin/restorecon ] && [ -r /etc/mtab ]
	then
		restorecon /etc/mtab
	fi

	#
	# Remove /run/rootdev if we created it.
	#
	rm -f /run/rootdev

	# Update mount options for mounts created in early boot
	# S01mountkernfs.sh
	/etc/init.d/mountkernfs.sh reload
	# S03mountdevsubfs.sh
	/etc/init.d/mountdevsubfs.sh reload

}

do_status () {
	# If / is read-write or swap is enabled, this script have done
	# its job.
	rootrw=false
	swapon=false
	if [ -f /etc/mtab ] ; then
	    if grep " / " /etc/mtab |grep -q rw ; then
		rootrw=true
	    fi
	fi
	if [ -f /proc/swaps ] ; then
	    if [ "$(cat /proc/swaps |grep -v ^Filename)" ] ; then
		swapon=true
	    fi
	fi
	if [ true = "$rootrw" ] || [ true = "$swapon" ] ; then
		return 0
	else
		return 4
	fi
}

case "$1" in
  start|"")
	do_start
	;;
  restart|reload|force-reload)
	echo "Error: argument '$1' not supported" >&2
	exit 3
	;;
  stop)
	# No-op
	;;
  status)
	do_status
	exit $?
	;;
  *)
	echo "Usage: checkroot.sh [start|stop]" >&2
	exit 3
	;;
esac

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