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Re: JFFS compression and hard links.



On Tue, 9 Jan 2001, David Woodhouse wrote:
> Hmmm... yeah, that could possibly work. It'll make the node lists more 
> complex, so as we've already got to break compatibility I'm tempted just to 
> add the extra field.

Ok.

> > This gets much simplier if we make the decision to only support
> > compress-once systems, where mkfs.jffs will do the compression and do
> > it so each jffs_node corresponds to one page, a la cramfs.
> 
> S'cheating. :)
> 
> We might as well bite the bullet and do dynamic compression right from the
> start - people want it.

Some people want it - I definitely don't want it and the iPAQ guys did not
want it either :) 

A mount option would be in order to disable/enable it I guess.

The problem with dynamic compression is that we cannot make a failsafe GC
run, because when joining nodes the resulting node can have a larger
size and thus we cannot guarantee that the GC run will stop. This can be
counteracted by allowing the GC to avoid the join in that case, but then
it's not really a GC and we run into other problems.

You remember that discussion we had some months ago where we discussed how
to make a failsafe GC run. You mentioned this problem yourself :) Can we
solve it some way ?

-BW



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