Making vsftpd with chrooted users work again on Ubuntu 12.04

http://blog.thefrontiergroup.com.au/2012/10/making-vsftpd-with-chrooted-users-work-again/

At The Frontier Group, we use vsftpd with chrooted users for clients that require FTP access. It has been working well for four years, however after a recent upgrade to Ubuntu 12.04 we started receiving this error message:

500
OOPS: vsftpd: refusing to run with writable root inside chroot ()

Ben Scobie has a good overview of the problem. One solution is adding the following to your vsftpd config file:

allow_writeable_chroot=YES

Unfortunately vsftpd 2.3.5, which is packaged in Ubuntu 12.04, doesn’t support this feature. It is only available in vsftpd 3 onwards.

As an alternative solution, we have backported it from vsftpd 3 into Ubuntu’s 2.3.5 package and made it available as a vsftpd PPA on Launchpad. To use it, run the
following:

sudo
add-apt-repository ppa:thefrontiergroup/vsftpd

sudo apt-get update

sudo apt-get install vsftpd

Update (31 Jan 2013): @JeyeNooks has backported the feature to Ubuntu 12.10, and has uploaded his package here.