#!/bin/bash
#
# zdev-root-update
#   Ensure that the persistent root device configuration is put into effect.
#   On typical distributions this requires a rebuild of the initial ram disk
#   and the re-installation of the IPL record referencing the ram disk.
#
#   Parameters:
#     zdev-root-update <devtype> <devid> [<devtype2> <devid2>...]
#
#     Where <devtype> is the device type as used by chzdev and <devid> is the
#     ID of the root device.
#

TOOLNAME=$(basename $0)
ZIPLCONF=/etc/zipl.conf

# die MESSAGE
# Print MESSAGE on standard error and exit with exit code 1
die()
{
	echo "$TOOLNAME: Error: $*" >&2
	exit 1
}

# add LIST NEW DELIM
# Add NEW to DELIM-separated LIST.
add()
{
	local LIST="$1"
	local NEW="$2"
	local DELIM="$3"

	if [ -z "$LIST" ] ; then
		echo "$NEW"
	else
		echo "$LIST$DELIM$NEW"
	fi
}

# add LIST NEW DELIM
# Add NEW to DELIM-separated LIST unless it is already in list.
add_unique()
{
	local LIST="$1"
	local NEW="$2"
	local DELIM="$3"
	local ENTRY
	local FOUND
	local IFS="$DELIM"

	FOUND=0
	for ENTRY in $LIST ; do
		if [ "$ENTRY" == "$NEW" ] ; then
			FOUND=1
			break
		fi
	done
	if [ "$FOUND" -eq 0 ] ; then
		LIST=$(add "$LIST" "$NEW" "$DELIM")
	fi

	echo "$LIST"
}

# process CMDLINE
# Apply root device settings from globals DASD ZFCP and CIOIGNORE to CMDLINE
process_cmdline()
{
	local CMDLINE="$1"
	local ENTRY
	local NEW
	local FOUND_DASD=0
	local FOUND_ZFCP=0
	local V
	local X

	for ENTRY in $CMDLINE ; do
		K=${ENTRY%%=*}
		case "$K" in
		dasd)
			if [ ! -z "$DASD" ] ; then
				NEW=$(add "$NEW" "dasd=$DASD" " ")
				FOUND_DASD=1
			fi
			;;
		zfcp.device)
			if [ ! -z "$ZFCP" ] ; then
				NEW=$(add "$NEW" "zfcp.device=$ZFCP" " ")
				FOUND_ZFCP=1
			fi
			;;
		cio_ignore)
			V=${ENTRY#*=}
			for X in $CIOIGNORE ; do
				V=$(add_unique "$V" "$X" ",")
			done
			NEW=$(add "$NEW" "cio_ignore=$V" " ")
			;;
		*)
			NEW=$(add "$NEW" "$ENTRY" " ")
			;;
		esac
	done

	if [ "$FOUND_DASD" -eq 0 -a ! -z "$DASD" ] ; then
		NEW=$(add "$NEW" "dasd=$DASD" " ")
	fi
	if [ "$FOUND_ZFCP" -eq 0 -a ! -z "$ZFCP" ] ; then
		NEW=$(add "$NEW" "zfcp.device=$ZFCP" " ")
	fi

	echo "$NEW"
}

# process_file FILENAME
# Apply root device settings from globals DASD ZFCP and CIOIGNORE to kernel
# command line found in file FILENAME
process_file()
{
	local FILENAME=$1
	local CMDLINE

	CMDLINE=$(cat $FILENAME)
	CMDLINE=$(process_cmdline "$CMDLINE")
	if ! echo $CMDLINE > "$FILENAME" ; then
		die "Could not write to $FILENAME"
	fi
}

# Build dasd= zfcp.device= and cio_ignore= parameter values
DASD=
ZFCP=
CIOIGNORE=
while [ $# -gt 0 ] ; do
	TYPE=$1
	ID=$2
	if [ -z "$TYPE" -o -z "$ID" ] ; then
		die "Incomplete parameters: $*"
	fi
	case $TYPE in
	dasd-*)
		DASD=$(add "$DASD" "$ID" ",")
		CIOIGNORE=$(add "$CIOIGNORE" "!$ID" " ")
		;;
	zfcp-lun)
		if [ ! -z "$ZFCP" ] ; then
			die "Too many zFCP SCSI devices used for root device"
		fi
		ZFCP=$(echo $ID | sed -e 's/:/,/g')
		FCPDEV=$(echo $ID | cut -d: -f1)
		CIOIGNORE=$(add "$CIOIGNORE" "!$FCPDEV" " ")
		;;
	*)
		die "Unsupported root device type: $TYPE"
		;;
	esac
	shift 2
done

if [ -z "$DASD" -a -z "$ZFCP" ] ; then
	die "No root device specified"
fi

if [ ! -r "$ZIPLCONF" ] ; then
	die "Could not read $ZIPLCONF"
fi

# Create new zipl.conf file
echo "Updating $ZIPLCONF"
TMPFILE=$(mktemp zdev-zipl.conf.XXX)
[ $? -ne 0 ] && die "Could not create temporary file"
while read LINE ; do
	OKEY=${LINE%%=*}
	KEY=$(echo $OKEY)
	case "$KEY" in
	parameters)
		V=$(echo ${LINE#*=} | sed -e 's/^"//' -e 's/"$//')
		V=$(process_cmdline "$V")
		echo "$OKEY=\"$V\""
		;;
	parmfile)
		V=$(echo ${LINE#*=} | sed -e 's/^"//' -e 's/"$//')
		process_file "$V"
		echo "$LINE"
	;;
	*)
		echo "$LINE"
		;;
	esac
done < "$ZIPLCONF" >"$TMPFILE"


# Swap new and old zipl.conf file
if ! mv "$ZIPLCONF" "${ZIPLCONF}.old" ; then
	die "Could not rename $ZIPLCONF to ${ZIPLCONF}.old"
fi
if ! mv $TMPFILE $ZIPLCONF ; then
	die "Could not rename $TMPFILE to $ZIPCONF"
fi
rm -f "${ZIPLCONF}.old"

# Install IPL loader
echo "Installing IPL record"
if ! zipl --noninteractive ; then
	die "Could not install IPL record"
fi