On Thu, Jul 17, 2003, at 11:36:01 2003 Joe Thornber
dm-devel@xxxxxxxxxxx wrote:
> On Thu, Jul 17, 2003 at 06:12:42PM +0200, Christophe Saout wrote:
>> Would it be possible to do development of these things (especially
>> the
>> dm part) to an open place? I'm very interested in the inner workings
>> of
>> device-mapper and the new 2.5/2.6 kernel block io code.
>
> Post your patches often, that way you'll get a lot more feedback. I
> tend to develop incremental patch sets.
> (eg. http://people.sistina.com/~thornber/internal-patches/raid1/) this
> allows people to see quickly what has changed. I have a little perl
> program that helps develop with such patchsets if you're interested.
to this mailing list, or the linux kernel development one ?
>> If I had more time and would be able to understand these things
>> better I
>> would have written some code by now (perhaps porting some of the
>> missing
>> dm targets from 2.4 to 2.5 or so), but if I can see progress step by
>> step I'll perhaps be able to help. Or at least test it.
>
> I'm working on the missing targets (snapshots and mirroring) already,
> also these two are *far* more complex than your crypto target will be.
yeah i can imagien
> Spend a day playing with dmsetup, and make sure you really understand
> how to write target types. The best way to learn is to try and write
> a trivial target type, eg. a 'reverse' target that divides the device
> into chunks and then reverses their order, ie. the first logical
chunk > is
> stored in the last logical chunk of the device. This should only take
> you ~150 lines of code (start with dm-linear.c and modify).
hmm, maybe the map into a file is a more trivial target ?
>> And, I was just wondering, would it be theoretically possible to
>> write a
>> dm target that stores data in a file, so that it replaces what the
>> loop device does? Or was dm not designed for this?
>
>> You could write a loop target, and people have suggested this
>> already. It's not something that I'm interested in doing however.
Would it be an easy target to write, such that i could play with a
dm-loop target before making the dm-crypt?
JonB
