Recreating an XFS file system with `ftype=1` Centos 7 (docker overlay2 storage dirver requirement)

Recreating an XFS file system with `ftype=1` CentOS 7

The CentOS 7 system where the root file system is XFS (created with ftype=0, the default CentOS)
setting at the time the system was installed). Unfortunately, the Docker overlay2 storage driver 
requires that file system to have been created with ftype=1:

https://docs.docker.com/storage/storagedriver/overlayfs-driver/#prerequisites

proposed method seemed to work fine. Here's the procedure:

1. Boot into CentOS-7-x86_64-LiveGNOME-1804.iso.
2. Open a terminal and sudo -s.
3. Scan for LVM volumes: vgscan
4. Change into the appropriate volume group (centos in my case): vgchange -ay centos
5. Scan for the logical volumes in that group: lvscan
6. Create a mount point for the root FS: mkdir /mnt/root
7. Mount the logical volume corresponding to the root FS: mount /dev/centos/root /mnt/root
8. Dump to remote host: xfsdump -J - /mnt/root | 'cat >/data/rootfs.dump'
9. Unmount the root FS: umount /mnt/root
10. Recreate the root FS: mkfs.xfs -f -n ftype=1 /dev/centos/root
11. Mount the recreated root FS: mount /dev/centos/root /mnt/root
12. Restore from remote host: 'cat /data/rootfs.dump' | xfsrestore -J - /mnt/root
13. Reboot. Everything should be as it was before, except xfs_info / should now show ftype=1