Re: [Dazuko-devel] Dazuko's 6th birthday (Wiki)

[John Ogness]

On 2008-02-06, jim burns <address@hidden> wrote:
>> From the Roadmap:
>> 1. release a version of Dazuko as a patch for Linux 2.6.24
>
> Why a patch instead of a kernel module?

The current release of Dazuko uses LSM to intercept file access
events. As of 2.6.24, LSM modules may no longer be kernel
modules. They _must_ be statically compiled into the kernel.

I am nearly finished with the patch, which will allow someone to
easily add Dazuko to their kernel code and compile their kernel. The
only part of the existing kernel code that the patch touches are
Makefile and Kconfig files.

>> 3. post experimental nullfs code
>
> What is nullfs?

The current experimental release of DazukoFS is based on the stackable
filesystem templates from the FiST project. However, I am not
satisfied with the implementation in those templates. Instead I have
written a new stackable filesystem from scratch (with FiST and
ecryptfs for partial referencing).

The stackable filesystem is called nullfs and does nothing but stack
on top of an existing filesystem. This provides an excellent test to
make sure that the stackable filesystem is correctly implemented.

I think nullfs could be of value as part of the Linux kernel. It would
function not only for general stacking tests, but also provide an
example for others interested in writing stackable filesystems. For
the future it could evolve to be part of a stackable framework, from
which all stackable filesystems could use. But that would be a
longterm goal to reduce redundancy in the kernel.

If nullfs could become part of mainline, it would be very simple to
get dazukofs into mainline. (The difference between nullfs and
dazukofs are around 30 lines of code.)

Although nullfs is currently not completed, it already works very well
(better than the FiST-template, in my opinion). I want to get the
current work of nullfs out to the public so that people can begin
seeing what I am working on.

John Ogness

-- 
Dazuko Maintainer