test_description="e2undo with the offset option (-o offset)"
OUT="$test_name.log"
TMPFILE2="${TMPFILE}_2"
TDB_FILE="$TMPFILE.e2undo"

E2UNDO_FEATURE_COMPAT_OFFSET=1

trap "rm -f $TMPFILE2 $TDB_FILE" EXIT INT QUIT

read_header_entry() {
	# $2 is just used as a dummy - it is never used by e2undo
	# when dumping the header
	$E2UNDO -h "$1" "$2" | grep "^$3:"
}

read_header_offset() {
	read_header_entry "$TDB_FILE" "$TMPFILE" "fs offset" | cut -f2
}

read_header_compat() {
	read_header_entry "$TDB_FILE" "$TMPFILE" "compat" | cut -f3
}

e2undo_offset_assert() {
	if [ "$crc_exp" != "$crc_act" -o \
		 "$offset_exp" != "$offset_act" -o \
		 $(($compat_act & $E2UNDO_FEATURE_COMPAT_OFFSET)) -ne $compat_exp ]
		then
		echo "$1" >> "$test_name.failed"
		echo "crc_exp: $crc_exp" >> "$test_name.failed"
		echo "crc_act: $crc_act" >> "$test_name.failed"
		echo "offset_exp: $offset_exp" >> "$test_name.failed"
		echo "offset_act: $offset_act" >> "$test_name.failed"
		echo "compat_exp: $compat_exp" >> "$test_name.failed"
		echo "compat_act: $compat_act" >> "$test_name.failed"
	fi
}

init_fs() {
	echo "#" >> "$OUT"
	echo "# init fs for $1" >> "$OUT"
	echo "#" >> "$OUT"
	rm -f "$TDB_FILE"
	dd if=/dev/zero of="$TMPFILE" bs=1k count=1024 > /dev/null 2>&1
	$MKE2FS -F -z "$TDB_FILE" -b 1024 -E offset=524288 "$TMPFILE" 512 \
		>> "$OUT" 2>&1
}

#
# test absence of the "-o N" option
#
test_e2undo_offset_no_option() {
	init_fs "test_e2undo_offset_no_option"

	$E2UNDO "$TDB_FILE" "$TMPFILE" >> "$OUT" 2>&1

	crc_exp=`dd if=/dev/zero bs=1k count=1024 2>/dev/null | $CRCSUM`
	crc_act=`$CRCSUM "$TMPFILE"`
	offset_exp=524288
	offset_act=`read_header_offset`
	compat_exp=$E2UNDO_FEATURE_COMPAT_OFFSET
	compat_act=`read_header_compat`
	e2undo_offset_assert "test_e2undo_offset_no_option"
}

#
# test removal of the offset feature in the undo header
#
test_e2undo_offset_no_option_remove_offset_header() {
	init_fs "test_e2undo_offset_no_option_remove_offset_header"
	dd if="$TMPFILE" of="$TMPFILE2" bs=1k count=512 skip=512 \
		> /dev/null 2>&1
	# offset feature will be removed from the undo header
	$TUNE2FS -z "$TDB_FILE" -C 42 "$TMPFILE2" >> "$OUT" 2>&1

	$E2UNDO "$TDB_FILE" "$TMPFILE2" >> "$OUT" 2>&1

	crc_exp=`dd if=/dev/zero bs=1k count=512 2>/dev/null | $CRCSUM`
	crc_act=`$CRCSUM "$TMPFILE2"`
	offset_exp=
	offset_act=`read_header_offset`
	compat_exp=0
	compat_act=`read_header_compat`
	e2undo_offset_assert "test_e2undo_offset_no_option_remove_offset_header"
}

#
# test "-o 4096"
#
test_e2undo_offset_4096() {
	init_fs "test_e2undo_offset_4096"
	dd if=/dev/zero of="$TMPFILE2" bs=1k count=4 > /dev/null 2>&1
	dd if="$TMPFILE" of="$TMPFILE2" bs=1k count=512 skip=512 seek=4 \
		> /dev/null 2>&1

	$E2UNDO -o 4096 "$TDB_FILE" "$TMPFILE2" >> "$OUT" 2>&1

	crc_exp=`dd if=/dev/zero bs=1k count=516 2>/dev/null | $CRCSUM`
	crc_act=`$CRCSUM "$TMPFILE2"`
	# the same as in test_e2undo_offset_no_option
	offset_exp=524288
	offset_act=`read_header_offset`
	compat_exp=$E2UNDO_FEATURE_COMPAT_OFFSET
	compat_act=`read_header_compat`
	e2undo_offset_assert "test_e2undo_offset_4096"
}

#
# test "-o 0"
#
test_e2undo_offset_0() {
	init_fs "test_e2undo_offset_0"
	dd if="$TMPFILE" of="$TMPFILE2" bs=1k count=512 skip=512 \
		> /dev/null 2>&1

	$E2UNDO -o 0 "$TDB_FILE" "$TMPFILE2" >> "$OUT" 2>&1

	crc_exp=`dd if=/dev/zero bs=1k count=512 2>/dev/null | $CRCSUM`
	crc_act=`$CRCSUM "$TMPFILE2"`
	# the same as in test_e2undo_offset_no_option
	offset_exp=524288
	offset_act=`read_header_offset`
	compat_exp=$E2UNDO_FEATURE_COMPAT_OFFSET
	compat_act=`read_header_compat`
	e2undo_offset_assert "test_e2undo_offset_0"
}

test_e2undo_offset_no_option
test_e2undo_offset_no_option_remove_offset_header
test_e2undo_offset_4096
test_e2undo_offset_0

if [ -e "$test_name.failed" ]; then
	echo "$test_name: $test_description: failed"
else
	echo "$test_name: $test_description: ok"
	touch "$test_name.ok"
fi