On Fri, Jun 18 2010 at 10:59am -0400, Christoph Hellwig <hch@xxxxxx> 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@xxxxxx> Acked-by: Mike Snitzer <snitzer@xxxxxxxxxx> 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/ -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
