[Unionfs] unionfs and sys_readahead and squashfs

[Paul Albrecht]

-----Original Message-----
From:	Erez Zadok [mailto:ezk at cs.sunysb.edu]
Sent:	Fri 11/9/2007 5:09 PM
To:	Phillip Lougher
Cc:	Erez Zadok; Paul Albrecht; unionfs at fsl.cs.sunysb.edu
Subject:	Re: [Unionfs] unionfs and sys_readahead and squashfs 

In message <bffbecbb0711091504j38aa4642icd1c85761165783e at mail.gmail.com>, "Phillip Lougher" writes:
> On Nov 9, 2007 1:55 AM, Erez Zadok <ezk at cs.sunysb.edu> wrote:
> > Paul, I'm happy to report that I wasn't able to reproduce this bug with
> > unionfs-2.1.8 and 2.6.24-rc1.
> >
> > I've offered to help the ubuntu guys move to unionfs-2.x.  I hope now that
> > their new release is done, they'd have more time to work with me on this
> > upgrade.
> 
> Hi Erez,
> 
> You should recall that I put the latest version of Unionfs (Unionfs
> 2.14 I believe) into the to-be-released  Gutsy Gibbon kernel back in
> September this year.   Subsequently I spent two weeks tracking down
> issues, putting in bug fixes, and generally getting Unionfs 2.1.x to
> work with the Ubuntu liveCD.
> 
> Since late September I have been off work due to an accident.  During
> that time another Canonical team member reverted Unionfs back to 1.4.
> I don't know why this was done, but I can only assume additional
> issues were found with the liveCD, and a reversion back to a known
> working Unionfs 1.4 was felt to be the best option.
> 
> Moving forward I believe Hardy Heron will and should support Unionfs
> 2.x.  Obviously, however, this can only be done once Unionfs 2.x works
> correctly with the liveCD.  If you're willing to help track down any
> issues we experience then that will be very helpful.

Absolutely willing (and able :-) to help.

To get [re]started, I'd like info on how I can get/download the following:

- a livecd image (w/ unionfs 1.x or 2.x, doesn't matter)
- kernels sources + .config for the livecd kernel
- any patches I may need on top of unionfs (eg. apparmor).

>

Here's a link to the download site for ubuntu:

http://www.ubuntu.com/getubuntu/download

Gutsy Gibbon, Ubuntu 7.10 is their latest release.

The kernel source is split in two git repos:

kernel.ubuntu.com/ubuntu/ubuntu-gutsy.git

for the kernel source. And, 

kernel.ubuntu.com/ubuntu/ubuntu-gutsy-lum.git

for module source.

I did this to get the source for both:

git clone git://kernel.ubuntu.com/ubuntu/ubuntu-gutsy.git ubuntu-gutsy
git clone git://kernel.ubuntu.com/ubuntu/ubuntu-gutsy-lum.git ubuntu-gutsy-lum

There are instructions for building and modifying their kernel on there wiki. Here's a link:

https://help.ubuntu.com/community/Kernel/Compile

Ubuntu is based on Debian so you the config is available in /boot directory.

I have attached a copy it to this message.

I looked through the source files and I'm not sure the code was reverted correctly because the unionfs documentation in the kernel source refers to unionfs 2.0. It might be a good idea to review the kernel and module sources to see that they're consistent.

If you develop a patch against ubuntu git source send it to me and I'll test it.

I don't know what ubuntu's plans are for gutsy gibbon now that its been released, but I hope they're planning on fixing this before hardy heron.

Paul Albrecht

-------------- next part --------------
A non-text attachment was scrubbed...
Name: config-2.6.22-14-generic
Type: application/octet-stream
Size: 75311 bytes
Desc: config-2.6.22-14-generic
Url : http://www.fsl.cs.sunysb.edu/pipermail/unionfs/attachments/20071111/304854df/config-2.6-0001.obj