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: (33 commits)
  dm mpath: support discard
  dm stripe: support discards
  dm: split discard requests on target boundaries
  dm stripe: optimize sector division
  dm stripe: move sector translation to a function
  dm: error return error for discards
  dm delay: support discard
  dm: zero silently drop discards
  dm: use dm_target_offset macro
  dm: factor out max_io_len_target_boundary
  dm: use common __issue_target_request for flush and discard support
  dm: linear support discard
  dm crypt: simplify crypt_ctr
  dm crypt: simplify crypt_config destruction logic
  dm: allow autoloading of dm mod
  dm: rename map_info flush_request to target_request_nr
  dm ioctl: refactor dm_table_complete
  dm snapshot: implement merge
  dm: do not initialise full request queue when bio based
  dm ioctl: make bio or request based device type immutable
  ...

Documentation/devices.txt

@@ -445,6 +445,7 @@ Your cooperation is appreciated.
 		233 = /dev/kmview	View-OS A process with a view
 		234 = /dev/btrfs-control	Btrfs control device
 		235 = /dev/autofs	Autofs control device
+		236 = /dev/mapper/control	Device-Mapper control device
 		240-254			Reserved for local use
 		255			Reserved for MISC_DYNAMIC_MINOR