[dm-devel] [RFC 1/2] block: implement an unprep function corresponding directly to prep

[FUJITA Tomonori]

On Wed, 30 Jun 2010 12:01:04 -0500
James Bottomley <James.Bottomley at suse.de> wrote:

> So this is more directly what I'm thinking.  It gives us an exactly
> correct place to hang the discard allocation in SCSI.  The next patch
> shows a potential implementation in sd.

Yeah, making the prep_rq_fn API symmetrical makes sense lots.

 
> I think it should avoid all the leaks people have been seeing trying to
> move the discard allocation/free into scsi.  I also think it should
> facilitate sending discard through SCSI as a REQ_TYPE_FS.

I think so. If I can figure out why qemu scsi driver is broken, the
job is done.

I'll see how this patchset works and update my FS discard patchset on
the top of this.