Restore File Owner from Backup, but not Content

By mistake we did a

chown www-data:www-data / -R

on a production server.

We do have a backup, but as only the permissions are wrong we want to restore only the permissions from the backup, not the file content.

Is there a simple command for this, for example with rsync?

It is possible with

getfacl -R /path/to/backup/on/backupserver > backup-acls.txt

and transfering the file on your production server, then

setfacl --test --restore=backup-acls.txt

After successfull test remove the --test option.

There might be errors for files such as PHP sessions which are no longer on the system, so these folders have to be checked manually.