for security purpose i want to create an linux user with simple password and this user will have permission only into /home/backup , how can i achieve this in linux?

Wery good can be if i can anyhow assign disk space quota to this folder so if account is compromised, abuser cant fill up whole disk partition..?


I found:

useradd usernamehere -d /fullpath/to/user/dir
passwd usernamehere
userdel usernamehere -r
-r will delete user directory