When copying to regular file, the length of the resulting file is equal to the size of the source filesystem.
I added an option which store only the amount of space actually used in the source filesystem by the filesystem and the XFS log.
Copy xfs filesystem on /dev/sdd1 to regular file as the amount used in filesystem.
$ xfs_copy -s /dev/sdd1 regular_file
Copy xfs filesystem to /dev/sdd1 from the regular file which was copied using "xfs_copy -s"
$ xfs_copy -f regular_file /dev/sdd1