The 2.x kernel source is available from
http://sunsite.unc.edu/pub/Linux/kernel/v2.0
Depending on the Linux distribution you have, you may, or may not have the quota softwares installed on your system. If you don't, then download the quota software source from
ftp://ftp.funet.fi/pub/Linux/PEOPLE/Linus/subsystems/quota/all.tar.gz.