[Dazuko-help] Getting DazukoFS to work on 2.6.26

[Bas Verhoeven]

Hi,

While browsing the web for a system that would allow me to somehow
restrict access to files by asking a userland program, I found Dazuko.
It appeared that Dazuko could basically do anything I want. It could
also give me all the information I need, pid, uid, etc.

Unfortunately, I soon found out that Dazuko was never going to work for
me. I'm on a Debian stock kernel with openvz patches applied. This
kernel doesn't like the "capabilities" thing (you can only turn it
on/off, can't make it modular), and I wouldn't be comfortable running
syscall hooks on a openvz system.

I tried to get it working for several hours, even tried several custom
kernels, but every time I tried to get a bit more information, I found
posts from people saying it simply won't work on newer kernels, and that
opening the "capabilities" thing would be a security risk. Not to
mention that it might break the openvz stuff.

Then yesterday I found a post on the Dazuko website that basically said
that Dazuko will no longer be supported. At that point, I just gave up
on Dazuko, and went to bed.

Then the next day, after reading the post a bit more, I noticed the
talks about DazukoFS.

Apparently this is some "stackable" filesystem that can basically do all
the stuff that Dazuko can do (notifications on open/close/unlink/etc.),
but does not require these kernel options that I mentioned above.

Obviously, if that is true, I'm very interested in such a development. I
tried to get it to work on my custom compiled kernel image: 2.6.26 (from
kernel.org) with openvz patches. The kernel compiled fine, and I'm
running it right now. Unfortunately, DazukoFS does not feel like installing:

debian:/tmp/dazukofs-3.0.0-rc5# patch -p1 < patch-linux-2.6.26
patching file file.c
patching file event.c
patching file ctrl_dev.c
patching file group_dev.c
patching file ign_dev.c
patching file inode.c
patching file super.c
debian:/tmp/dazukofs-3.0.0-rc5# make
make -C /lib/modules/`uname -r`/build SUBDIRS="`pwd`" modules
make[1]: Entering directory `/usr/src/linux-2.6.26'
 CC [M]  /tmp/dazukofs-3.0.0-rc5/super.o
 CC [M]  /tmp/dazukofs-3.0.0-rc5/inode.o
/tmp/dazukofs-3.0.0-rc5/inode.c: In function 'dazukofs_permission':
/tmp/dazukofs-3.0.0-rc5/inode.c:468: error: implicit declaration of
function 'GET_LOWER_MNT'
/tmp/dazukofs-3.0.0-rc5/inode.c:468: warning: assignment makes pointer
from integer without a cast
/tmp/dazukofs-3.0.0-rc5/inode.c:469: error: implicit declaration of
function 'GET_LOWER_DENTRY'
/tmp/dazukofs-3.0.0-rc5/inode.c:469: warning: assignment makes pointer
from integer without a cast
/tmp/dazukofs-3.0.0-rc5/inode.c:477: error: implicit declaration of
function 'GET_LOWER_INODE'
/tmp/dazukofs-3.0.0-rc5/inode.c:477: warning: passing argument 1 of
'permission' makes pointer from integer without a cast
make[2]: *** [/tmp/dazukofs-3.0.0-rc5/inode.o] Error 1
make[1]: *** [_module_/tmp/dazukofs-3.0.0-rc5] Error 2
make[1]: Leaving directory `/usr/src/linux-2.6.26'
make: *** [dazukofs_modules] Error 2

I'm not sure wether this is an error in DazukoFS (it appears to be, as
it's using functions that appear to belong to DazukoFS), or if my openvz
kernel broke something.

I'd appreciate it if you could help me out on this one.

Thanks,
Bas Verhoeven