#!/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
#				 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
}

# 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 's/.*/,&,/'                 | \
	sed 's/,'"$OPT"'=[0-9]*,/,/g'   | \
	sed 's/,,*/,/g'                 | \
	sed 's/^,//'                    | \
	sed 's/,$//'                    | \
	cat -
}

# 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 's/.*/,&,/'                 | \
	sed 's/,'"$OPT"',/,/g'          | \
	sed 's/,,*/,/g'                 | \
	sed 's/^,//'                    | \
	sed 's/,$//'                    | \
	cat -
}

# 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
	shift
	OPT=$1
	shift
	DEF_OPT=$1
	shift
	L_OPTS="$*"
	PARSEDOPTS1="$(parse_nonumber_mount_opts $OPT $L_OPTS)"
	PARSEDOPTS1="$(parse_nonumber_mount_opts no$OPT $PARSEDOPTS1)"
	# Watch for a default atime in fstab
	FSTAB_OPTS="$(cat /etc/fstab | sed 's/  / /g' | grep ^\ *"$L_DEV " | awk '{ print $4 }')"
	if [ -z "$(echo "$FSTAB_OPTS" | grep "$OPT")" ] ; then
		# option not specified in fstab -- choose the default.
		echo "$PARSEDOPTS1,$DEF_OPT"
	else
		# option specified in fstab: extract the value and use it
		if [ -z "$(echo "$FSTAB_OPTS" | grep "no$OPT")" ] ; then
			# no$OPT not found -- so we must have $OPT.
			echo "$PARSEDOPTS1,$OPT"
		else
			echo "$PARSEDOPTS1,no$OPT"
		fi
	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
	shift
	OPT=$1
	shift
	L_OPTS="$*"

	PARSEDOPTS1="$(parse_mount_opts $OPT $L_OPTS)"
	# Watch for a default commit in fstab
	FSTAB_OPTS="$(cat /etc/fstab | sed 's/  / /g' | grep ^\ *"$L_DEV " | awk '{ print $4 }')"
	if [ -z "$(echo "$FSTAB_OPTS" | grep "$OPT=")" ] ; then
		# option not specified in fstab: set it to 0
		echo "$PARSEDOPTS1,$OPT=0"
	else
		# option specified in fstab: extract the value, and use it
		echo -n "$PARSEDOPTS1,$OPT="
		echo "$FSTAB_OPTS"      | \
		sed 's/.*/,&,/'         | \
		sed 's/.*,'"$OPT"'=//'  | \
		sed 's/,.*//'           | \
		cat -
	fi
}

proc_save() {
	if ! cat /proc/sys/vm/$1 >/var/lib/laptop_mode/$1; then
		eerror "Could not save /proc/sys/vm/$1. Make sure /var/lib/laptop_mode exists."
		return 1
	fi
}

proc_restore() {
	if [ -f /var/lib/laptop_mode/$1 ]; then
		cat /var/lib/laptop_mode/$1 >/proc/sys/vm/$1
		rm -f /var/lib/laptop_mode/$1
	fi
}

checkconfig() {
	KLEVEL=$(
		uname -r |
		(
			IFS="." read a b c
			echo $a.$b
		)
	)
	case "$KLEVEL" in
		"2.4"|"2.6")
			true
			;;
		*)
			echo "Unhandled kernel version: $KLEVEL ('uname -r' = '$(uname -r)')"
			exit 1
			;;
	esac
	
	if [ ! -e /proc/sys/vm/laptop_mode ]; then
		echo "Kernel is not patched with laptop_mode patch."
		exit 1
	fi
	
	if [ ! -w /proc/sys/vm/laptop_mode ]; then
		echo "You do not have enough privileges to enable laptop_mode."
		exit 1
	fi

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

	all_discs=""
	for i in `dir /dev/discs`; do
		if [ ! -n "`ls -la /dev/discs/${i} | grep scsi`" ]; then
			all_discs="${all_discs} `basename ${i}`"
		fi
	done
}

start() {
	checkconfig || return 1
	ebegin "Starting laptop_mode"

	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 "$OPTS")"
			case "$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

	for i in ${all_discs}; do
		if ! hdparm -S$HD_STANDBY /dev/discs/$i/disc &>/dev/null; then
			ewarn "Failed to set disc standby on $i"
		fi
	done
	eend 0
}

stop() {
	checkconfig || return 1
	ebegin "Stopping laptop_mode"

	U_AGE=$((100*$DEF_UPDATE))
	B_AGE=$((100*$DEF_AGE))

	echo "0" > /proc/sys/vm/laptop_mode
	if [ -f /proc/sys/fs/xfs/age_buffer ] && [ ! -f /proc/sys/fs/xfs/lm_age_buffer ] ; then
		# These need to be restored though, 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 [ $DO_REMOUNTS -eq 1 ]; then
		cat /etc/mtab | while read DEV MP FST OPTS DUMP PASS ; do
			# Reset commit and atime options to defaults.
			case "$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
	
	for i in ${all_discs}; do
		if ! hdparm -S0 /dev/discs/$i/disc &>/dev/null; then
			ewarn "Failed to set disc standby on $i"
		fi
	done
	eend 0
}