JFFS2 compression

[David Woodhouse]

On Tue, 2004-10-19 at 12:09 +0200, Ferenc Havasi wrote:
> Hi Artem,
> 
> > Just wonder, why the compression mode is the global variable 
> > (jffs2_get_compression_mode, defined in compr.c). Theoretically, it 
> > should be the attribute of superblock (in this case it would be possible 
> > to have several JFFS2 filesystems with different compression modes).
> 
> Now the compression mode is a global thing. It can be configured by 
> kernelconfig and is the same for every filesystem. There is no reserved 
> space to store it in the different JFFS2 filesystems (it should need a 
> new type of node or something like that).
> 
> There is plans for the future. One of them: there will be "compression 
> configurations". This is much more general thing than compression mode. 

Increasingly, I think I'd like to see the compression code taken out of
JFFS2 and moved somewhere where other things in the kernel can use it.
While we had only a few local hacks it made a certain amount of sense
for it to be kept private, but now it's getting a lot more useful, I
don't think it should be limited to JFFS2.

We should probably plug it in using the crypto API or something similar.
There's not a _huge_ amount of difference between compression routines
and crypto routines. 

-- 
dwmw2