Reduce XFS fylesystem
XFS fylesystem can not be reduced, only extended. In order to reduce it, you need to delete the filesystem and then recreate it with the new capacity.
Before to delete it, we will backup it, and once the filesystem has been recreated, we will restore it.
xfsdump -l 0 -f /ome-image /dev/mapper/centos-home
umount /home lvremove /dev/centos/home
lvcreate -L 20G -n home centos
mount /home xfsrestore -f /home-image /home
lvextend -L +20G /dev/centos/root