RFC: Pass TRIM through GELI

[Matthew D. Fuller]

On Mon, Jul 13, 2015 at 05:31:46PM +0200 I heard the voice of
Pawel Jakub Dawidek, and lo! it spake thus:
> 
> So what do you guys think about implementing trim support this way:
> 
> 	geli -d <trim|overwrite|ignore>
> 
> 'overwrite' may be implemented later and 'trim' would be the default?

Well, if you ask me, we can work out the UI for a 3-way choice when a
third way is implemented.  Doing shredding would presumably be noted
by adding another flag[0] for it anyway, so doing it on top of this
patch oughtn't take it out of its way.  Nobody's implemented it in the
last 10 years that there's been a comment suggesting it.

So, from my selfish perspective, I'd as soon land this as a solid step
forward, and worry about a shredding implementation when one gets
written...


[0] I mean, I _guess_ we could add another element into the
    metadata/softc structs just to hold a 3-way 'delete handling'
    option, but that sounds way heavier-weight than necessary.  Also
    would need new geli version and blah.


-- 
Matthew Fuller     (MF4839)   |  fullermd at over-yonder.net
Systems/Network Administrator |  http://www.over-yonder.net/~fullermd/
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