Re: Suggestion for Linux 2.3

bofh@snoopy.virtual.net.au
Tue, 07 Jan 97 22:06:15 +1000


"David S. Miller" <davem@jenolan.rutgers.edu> said:
> Date: Mon, 6 Jan 1997 17:23:01 -0600 (CST)
> From: "Daniel G. Linder" <dlinder@webcentric.net>

> Anyone want to work on this for Linux? I don't have the time to be
> a lead person, but this looks like it would integrate well with the
> MD driver (Multi Disk)... Might be a big step for ext2 -- anything
> going on with that project?

>I would like to see full logging and journaling added to ext2 before we allow
>such a scheme.

>Actually to add a disk to a "raw" partition is at a lower level then the
>filesystem itself. Generic code could handle this.

>The filesystem will (ideally) not have to know this has happened. It will
>just be the same sized filesystem, but the partition itself will have new
>logical disk blocks it just isn't using.

>Then you can add hacks the filesystem specific code to allow for
>growing a filesystem like AIX does, after the above partition
>extending has been implemented.

>These are all non-trivial hacks.

There are people working on all these things right now. I have been doing a
bit of research on this to find out whether anyone else had plans for
developing something like ADVFS for Linux. The projects to add journalling etc
to Ext2 all seem to be too much hacks for my liking. To add these features you
would have to change the FS metadata on disk which would almost certainly
require making the disk format incompatible with Ext2. I believe that if you
are going to lost compatibility anyway then you shouldn't compromise the design
for compatibility. That is why I have started a project to design a new file
system from the ground up to support these features. If possible I will use
code from Ext2 and MD if possible (the code in those projects is good and
tested so I want to use it if it'll work), but I don't want to compromise the
design.

Russell Coker