xfs: test xfs_getbmapx behavior with shared extents

Make sure that xfs_getbmapx behaves properly w.r.t. shared extents
and CoW fork reporting.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

common/rc

@@ -3075,6 +3075,25 @@ _require_xfs_scratch_rmapbt()
 	_scratch_unmount
 }
 
+_xfs_bmapx_find() {
+	case "$1" in
+	"attr")
+		param="a"
+		;;
+	"cow")
+		param="c"
+		;;
+	*)
+		param="e"
+		;;
+	esac
+	shift
+	file="$1"
+	shift
+
+	"$XFS_IO_PROG" -c "bmap -${param}lpv" "$file" | grep -c "$@"
+}
+
 _get_total_inode()
 {
 	if [ -z "$1" ]; then