#!/sbin/runscript
# Copyright 1999-2004 Gentoo Technologies, Inc.
# Distributed under the terms of the GNU General Public License v2
# $Header:

# start or stop laptop_mode, best run by a power management daemon when
# ac gets connected/disconnected from a laptop
#
# Contributors to this script: 
# Kiko Piris
# Bart Samwel
# Micha Feigin
# Andrew Morton
# Herve Eychenne
# Dax Kelson
#
# Original Linux 2.4 version by: Jens Axboe
#
# Adapted to Gentoo Linux by Johannes Ballé
# Updated by Dennis Nienhüser

depend() {
	need localmount
	# make sure standby settings by hdparm init script are overridden
	use hdparm
}


setDefaults() {
	# Don't raise an error if the config file is incomplete
	# set defaults instead:

	# Maximum time, in seconds, of hard drive spindown time that you are
	# confortable with. Worst case, it's possible that you could lose this
	# amount of work if your battery fails you while in laptop mode.
	MAX_AGE=${MAX_AGE:-'600'}

	# Read-ahead, in kilobytes
	READAHEAD=${READAHEAD:-'4096'}

	# Shall we remount journaled fs. with appropiate commit interval? (1=yes)
	DO_REMOUNTS=${DO_REMOUNTS:-'1'}

	# And shall we add the "noatime" option to that as well? (1=yes)
	DO_REMOUNT_NOATIME=${DO_REMOUNT_NOATIME:-'1'}

	# Shall we adjust the idle timeout on a hard drive?
	DO_HD=${DO_HD:-'1'}

	# Adjust idle timeout on which hard drive?
	HD="${HD:-'/dev/hda'}"

	# spindown time for HD (hdparm -S values)
	AC_HD=${AC_HD:-'244'}
	BATT_HD=${BATT_HD:-'4'}

	# Dirty synchronous ratio.  At this percentage of dirty pages the process which
	# calls write() does its own writeback
	DIRTY_RATIO=${DIRTY_RATIO:-'40'}

	# cpu frequency scaling
	# See Documentation/cpu-freq/user-guide.txt for more info
	DO_CPU=${CPU_MANAGE:-'0'}
	CPU_MAXFREQ=${CPU_MAXFREQ:-'slowest'}

	#
	# Allowed dirty background ratio, in percent. Once DIRTY_RATIO has been
	# exceeded, the kernel will wake pdflush which will then reduce the amount
	# of dirty memory to dirty_background_ratio. Set this nice and low, so once
	# some writeout has commenced, we do a lot of it.
	#
	DIRTY_BACKGROUND_RATIO=${DIRTY_BACKGROUND_RATIO:-'5'}

	# kernel default dirty buffer age
	DEF_AGE=${DEF_AGE:-'30'}
	DEF_UPDATE=${DEF_UPDATE:-'5'}
	DEF_DIRTY_BACKGROUND_RATIO=${DEF_DIRTY_BACKGROUND_RATIO:-'10'}
	DEF_DIRTY_RATIO=${DEF_DIRTY_RATIO:-'40'}
	DEF_XFS_AGE_BUFFER=${DEF_XFS_AGE_BUFFER:-'15'}
	DEF_XFS_SYNC_INTERVAL=${DEF_XFS_SYNC_INTERVAL:-'30'}
	DEF_XFS_BUFD_INTERVAL=${DEF_XFS_BUFD_INTERVAL:-'1'}

	# This must be adjusted manually to the value of HZ in the running kernel
	# on 2.4, until the XFS people change their 2.4 external interfaces to work in
	# centisecs. This can be automated, but it's a work in progress that still needs
	# some fixes. On 2.6 kernels, XFS uses USER_HZ instead of HZ for external
	# interfaces, and that is currently always set to 100. So you don't need to
	# change this on 2.6.
	XFS_HZ=${XFS_HZ:-'100'}

	if [ $DO_REMOUNT_NOATIME -eq 1 ] ; then
		NOATIME_OPT=",noatime"
	fi
}


checkconfig() {
	KLEVEL="$(uname -r |
							{
					IFS='.' read a b c
					echo $a.$b
				}
	)"
	case "$KLEVEL" in
		"2.4"|"2.6")
			;;
		*)
			echo "Unhandled kernel version: $KLEVEL ('uname -r' = '$(uname -r)')" >&2
			exit 1
			;;
	esac

	if [ ! -e /proc/sys/vm/laptop_mode ] ; then
		echo "Kernel is not patched with laptop_mode patch." >&2
		exit 1
	fi

	if [ ! -w /proc/sys/vm/laptop_mode ] ; then
		echo "You do not have enough privileges to enable laptop_mode." >&2
		exit 1
	fi
}

# Remove an option (the first parameter) of the form option=<number> from
# a mount options string (the rest of the parameters).
parse_mount_opts () {
	OPT="$1"
	shift
	echo ",$*," | sed \
	-e 's/,'"$OPT"'=[0-9]*,/,/g' \
	-e 's/,,*/,/g' \
	-e 's/^,//' \
	-e 's/,$//'
}

# Remove an option (the first parameter) without any arguments from
# a mount option string (the rest of the parameters).
parse_nonumber_mount_opts () {
	OPT="$1"
	shift
	echo ",$*," | sed \
	-e 's/,'"$OPT"',/,/g' \
	-e 's/,,*/,/g' \
	-e 's/^,//' \
	-e 's/,$//'
}

# Find out the state of a yes/no option (e.g. "atime"/"noatime") in
# fstab for a given filesystem, and use this state to replace the
# value of the option in another mount options string. The device
# is the first argument, the option name the second, and the default
# value the third. The remainder is the mount options string.
#
# Example:
# parse_yesno_opts_wfstab /dev/hda1 atime atime defaults,noatime
#
# If fstab contains, say, "rw" for this filesystem, then the result
# will be "defaults,atime".
parse_yesno_opts_wfstab () {
	L_DEV="$1"
	OPT="$2"
	DEF_OPT="$3"
	shift 3
	L_OPTS="$*"
	PARSEDOPTS1="$(parse_nonumber_mount_opts $OPT $L_OPTS)"
	PARSEDOPTS1="$(parse_nonumber_mount_opts no$OPT $PARSEDOPTS1)"
	# Watch for a default atime in fstab
	FSTAB_OPTS="$(awk '$1 == "'$L_DEV'" { print $4 }' /etc/fstab)"
	if echo "$FSTAB_OPTS" | grep "$OPT" > /dev/null ; then
		# option specified in fstab: extract the value and use it
		if echo "$FSTAB_OPTS" | grep "no$OPT" > /dev/null ; then
			echo "$PARSEDOPTS1,no$OPT"
		else
			# no$OPT not found -- so we must have $OPT.
			echo "$PARSEDOPTS1,$OPT"
		fi
	else
		# option not specified in fstab -- choose the default.
		echo "$PARSEDOPTS1,$DEF_OPT"
	fi
}

# Find out the state of a numbered option (e.g. "commit=NNN") in
# fstab for a given filesystem, and use this state to replace the
# value of the option in another mount options string. The device
# is the first argument, and the option name the second. The
# remainder is the mount options string in which the replacement
# must be done.
#
# Example:
# parse_mount_opts_wfstab /dev/hda1 commit defaults,commit=7
#
# If fstab contains, say, "commit=3,rw" for this filesystem, then the
# result will be "rw,commit=3".
parse_mount_opts_wfstab () {
	L_DEV="$1"
	OPT="$2"
	shift 2
	L_OPTS="$*"
	PARSEDOPTS1="$(parse_mount_opts $OPT $L_OPTS)"
	# Watch for a default commit in fstab
	FSTAB_OPTS="$(awk '$1 == "'$L_DEV'" { print $4 }' /etc/fstab)"
	if echo "$FSTAB_OPTS" | grep "$OPT=" > /dev/null ; then
		# option specified in fstab: extract the value, and use it
		echo -n "$PARSEDOPTS1,$OPT="
		echo ",$FSTAB_OPTS," | sed \
		-e 's/.*,'"$OPT"'=//' \
		-e 's/,.*//'
	else
		# option not specified in fstab: set it to 0
		echo "$PARSEDOPTS1,$OPT=0"
	fi
}

deduce_fstype () {
	MP="$1"
	# My root filesystem unfortunately has
	# type "unknown" in /etc/mtab. If we encounter
	# "unknown", we try to get the type from fstab.
	cat /etc/fstab |
	grep -v '^#' |
	while read FSTAB_DEV FSTAB_MP FSTAB_FST FSTAB_OPTS FSTAB_DUMP FSTAB_DUMP ; do
		if [ "$FSTAB_MP" = "$MP" ]; then
			echo $FSTAB_FST
			exit 0
		fi
	done
}


start() {
	ebegin "Starting laptop_mode"

	setDefaults
	checkconfig || return 1

	AGE=$((100*$MAX_AGE))
	XFS_AGE=$(($XFS_HZ*$MAX_AGE))
	echo -n "Starting laptop_mode"

	if [ -d /proc/sys/vm/pagebuf ] ; then
		# (For 2.4 and early 2.6.)
		# This only needs to be set, not reset -- it is only used when
		# laptop mode is enabled.
		echo $XFS_AGE > /proc/sys/vm/pagebuf/lm_flush_age
		echo $XFS_AGE > /proc/sys/fs/xfs/lm_sync_interval
	elif [ -f /proc/sys/fs/xfs/lm_age_buffer ] ; then
		# (A couple of early 2.6 laptop mode patches had these.)
		# The same goes for these.
		echo $XFS_AGE > /proc/sys/fs/xfs/lm_age_buffer
		echo $XFS_AGE > /proc/sys/fs/xfs/lm_sync_interval
	elif [ -f /proc/sys/fs/xfs/age_buffer ] ; then
		# (2.6.6)
		# But not for these -- they are also used in normal
		# operation.
		echo $XFS_AGE > /proc/sys/fs/xfs/age_buffer
		echo $XFS_AGE > /proc/sys/fs/xfs/sync_interval
	elif [ -f /proc/sys/fs/xfs/age_buffer_centisecs ] ; then
		# (2.6.7 upwards)
		# And not for these either. These are in centisecs,
		# not USER_HZ, so we have to use $AGE, not $XFS_AGE.
		echo $AGE > /proc/sys/fs/xfs/age_buffer_centisecs
		echo $AGE > /proc/sys/fs/xfs/xfssyncd_centisecs
		echo 3000 > /proc/sys/fs/xfs/xfsbufd_centisecs
	fi

	case "$KLEVEL" in
		"2.4")
			echo 1 > /proc/sys/vm/laptop_mode
			echo "30 500 0 0 $AGE $AGE 60 20 0" > /proc/sys/vm/bdflush
			;;
		"2.6")
			echo 5 > /proc/sys/vm/laptop_mode
			echo "$AGE" > /proc/sys/vm/dirty_writeback_centisecs
			echo "$AGE" > /proc/sys/vm/dirty_expire_centisecs
			echo "$DIRTY_RATIO" > /proc/sys/vm/dirty_ratio
			echo "$DIRTY_BACKGROUND_RATIO" > /proc/sys/vm/dirty_background_ratio
			;;
	esac
	if [ $DO_REMOUNTS -eq 1 ]; then
		cat /etc/mtab | while read DEV MP FST OPTS DUMP PASS ; do
			PARSEDOPTS="$(parse_mount_opts "$OPTS")"
			if [ "$FST" = 'unknown' ]; then
				FST=$(deduce_fstype $MP)
			fi
			case "$FST" in
				"ext3"|"reiserfs")
					PARSEDOPTS="$(parse_mount_opts commit "$OPTS")"
					mount $DEV -t $FST $MP -o remount,$PARSEDOPTS,commit=$MAX_AGE$NOATIME_OPT
					;;
				"xfs")
					mount $DEV -t $FST $MP -o remount,$OPTS$NOATIME_OPT
					;;
			esac
			if [ -b $DEV ] ; then
				blockdev --setra $(($READAHEAD * 2)) $DEV
			fi
		done
	fi
	if [ $DO_HD -eq 1 ] ; then
		for THISHD in $HD ; do
			/sbin/hdparm -S $BATT_HD $THISHD > /dev/null 2>&1
			/sbin/hdparm -B 1 $THISHD > /dev/null 2>&1
		done
	fi
	if [ $DO_CPU -eq 1 -a -e /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq ]; then
		if [ $CPU_MAXFREQ = 'slowest' ]; then
			CPU_MAXFREQ=`cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq`
		fi
		echo $CPU_MAXFREQ > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
	fi

	eend 0
}

stop() {
	ebegin "Stopping laptop mode"
	setDefaults

	U_AGE=$((100*$DEF_UPDATE))
	B_AGE=$((100*$DEF_AGE))
	echo -n "Stopping laptop_mode"
	echo 0 > /proc/sys/vm/laptop_mode
	if [ -f /proc/sys/fs/xfs/age_buffer -a ! -f /proc/sys/fs/xfs/lm_age_buffer ] ; then
		# These need to be restored, if there are no lm_*.
		echo $(($XFS_HZ*$DEF_XFS_AGE_BUFFER)) > /proc/sys/fs/xfs/age_buffer
		echo $(($XFS_HZ*$DEF_XFS_SYNC_INTERVAL)) > /proc/sys/fs/xfs/sync_interval
	elif [ -f /proc/sys/fs/xfs/age_buffer_centisecs ] ; then
		# These need to be restored as well.
		echo $((100*$DEF_XFS_AGE_BUFFER)) > /proc/sys/fs/xfs/age_buffer_centisecs
		echo $((100*$DEF_XFS_SYNC_INTERVAL)) > /proc/sys/fs/xfs/xfssyncd_centisecs
		echo $((100*$DEF_XFS_BUFD_INTERVAL)) > /proc/sys/fs/xfs/xfsbufd_centisecs
	fi
	case "$KLEVEL" in
		"2.4")
			echo "30 500 0 0 $U_AGE $B_AGE 60 20 0" > /proc/sys/vm/bdflush
			;;
		"2.6")
			echo "$U_AGE" > /proc/sys/vm/dirty_writeback_centisecs
			echo "$B_AGE" > /proc/sys/vm/dirty_expire_centisecs
			echo "$DEF_DIRTY_RATIO" > /proc/sys/vm/dirty_ratio
			echo "$DEF_DIRTY_BACKGROUND_RATIO" > /proc/sys/vm/dirty_background_ratio
			;;
	esac
	if [ $DO_REMOUNTS -eq 1 ] ; then
		cat /etc/mtab | while read DEV MP FST OPTS DUMP PASS ; do
			# Reset commit and atime options to defaults.
			if [ "$FST" = 'unknown' ]; then
				FST=$(deduce_fstype $MP)
			fi
			case "$FST" in
				"ext3"|"reiserfs")
					PARSEDOPTS="$(parse_mount_opts_wfstab $DEV commit $OPTS)"
					PARSEDOPTS="$(parse_yesno_opts_wfstab $DEV atime atime $PARSEDOPTS)"
					mount $DEV -t $FST $MP -o remount,$PARSEDOPTS
					;;
				"xfs")
					PARSEDOPTS="$(parse_yesno_opts_wfstab $DEV atime atime $OPTS)"
					mount $DEV -t $FST $MP -o remount,$PARSEDOPTS
					;;
			esac
			if [ -b $DEV ] ; then
				blockdev --setra 256 $DEV
			fi
		done
	fi
	if [ $DO_HD -eq 1 ] ; then
		for THISHD in $HD ; do
			/sbin/hdparm -S $AC_HD $THISHD > /dev/null 2>&1
			/sbin/hdparm -B 255 $THISHD > /dev/null 2>&1
		done
	fi
	if [ $DO_CPU -eq 1 -a -e /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq ]; then
		echo `cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq` > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
	fi

	eend 0
}