Merge tag 'dm-3.9-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm

Merge tag 'dm-3.9-fixes-2' of git://git./linux/kernel/git/agk/linux-dm

Pull device-mapper fixes from Alasdair Kergon:
 "A pair of patches to fix the writethrough mode of the device-mapper
  cache target when the device being cached is not itself wrapped with
  device-mapper."

* tag 'dm-3.9-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm:
  dm cache: reduce bio front_pad size in writeback mode
  dm cache: fix writes to cache device in writethrough mode