How to set quotas per folder for different users in Debian?

Question

Debian

Good afternoon! Please advise how can I set quotas in Debian 7 per folder.
The folder is owned by (for example) username, half of the data in it belongs to him, and the other half is www-data. How to make sure that all folders and files in the parent directory, even those belonging to other users, are considered in the quota not for www-data, but for the owner?

Answer 1

only the creation of one group comes to mind, in which to push the necessary users, and assign rights to the group, no?