/usr/sbin/xfs_ncheck is in xfsprogs 4.9.0+nmu1.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 | #!/bin/sh -f
#
# Copyright (c) 2000-2001 Silicon Graphics, Inc.  All Rights Reserved.
#
OPTS=" "
DBOPTS=" "
USAGE="usage: xfs_ncheck [-sfV] [-l logdev] [-i ino]... special"
while getopts "b:fi:l:svV" c
do
	case $c in
	s)	OPTS=$OPTS"-s ";;
	i)	OPTS=$OPTS"-i "$OPTARG" ";;
	v)	OPTS=$OPTS"-v ";;
	f)	DBOPTS=$DBOPTS" -f";;
	l)	DBOPTS=$DBOPTS" -l "$OPTARG" ";;
	V)	xfs_db -p xfs_ncheck -V
		status=$?
		exit $status
		;;
	\?)	echo $USAGE 1>&2
		exit 2
		;;
	esac
done
set -- extra $@
shift $OPTIND
case $# in
	1)	xfs_db$DBOPTS -r -p xfs_ncheck -c "blockget -ns" -c "ncheck$OPTS" $1
		status=$?
		;;
	*)	echo $USAGE 1>&2
		exit 2
		;;
esac
exit $status
 |