Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm

Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm

* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm:
  dm kcopyd: fix callback race
  dm kcopyd: prepare for callback race fix
  dm: implement basic barrier support
  dm: remove dm_request loop
  dm: rework queueing and suspension
  dm: simplify dm_request loop
  dm: split DMF_BLOCK_IO flag into two
  dm: rearrange dm_wq_work
  dm: remove limited barrier support
  dm: add integrity support