Messages in this thread | | | Date | Sat, 19 Jun 2010 00:25:34 -0400 | From | Mike Snitzer <> | Subject | Re: [PATCH, RFC] block: don't allocate a payload for discard request |
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On Fri, Jun 18 2010 at 10:59am -0400, Christoph Hellwig <hch@lst.de> wrote:
> > Allocating a fixed payload for discard requests always was a horrible hack, > and it's not coming to byte us when adding support for discard in DM/MD. > > So change the code to leave the allocation of a payload to the lowlevel > driver. Unfortunately that means we'll need another hack, which allows > us to update the various block layer length fields indicating that we > have a payload. Instead of hiding this in sd.c, which we already partially > do for UNMAP support add a documented helper in the core block layer for it. > > Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
I've built on your patch to successfully implement discard support for DM (this includes splitting discards that span targets; only the linear and striped DM targets are supported so far).
The patchset is still a work in progress but is available here (against 2.6.34 at the moment): http://people.redhat.com/msnitzer/patches/dm-discard/latest/
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