Revision 1:
  Documentation for the linear target.  The last 2 scripts still need
  testing.

Revision 2:
  dm-ioctl.c: Fix an OB1 error when calculating an output buffer size,
  that could cause a missing null termininator in the 'list devices'
  ioctl results.  [Steffan Paletta]

Revision 3:
  In __map_bio(), if the target returns an error while mapping the I/O, the
  cloned bio needs to be freed.

Revision 4:
  Replace dm_[add|remove]_wait_queue() with dm_wait_event().
  
  Some testing of DM multipath has turned up a problem with the DEVICE_WAIT
  command. In the tests, while performing a DEVICE_WAIT on a multipath device,
  the command sometimes returns immediately, even though the event-number is
  correct and no path-failure has occurred to trigger an event. The problem
  was tracked down to the call to schedule() in dev_wait(), which would return
  even though it was not woken up by a DM table event.
  
  This patch moves the responsibility for waiting from the ioctl interface into
  the core driver, and uses wait_event_interruptible() instead of relying on
  wait-queues and schedule().

Revision 5:
  Multipath target

Revision 6:
  dm-io

Revision 7:
  kcopyd

Revision 8:
  Force kcopyd to be single-threaded. For now, snapshotting cannot handle
  multiple kcopyd threads. When we determine the correct way to make snapshot
  safe for a multithreaded kcopyd, this patch can be removed.

Revision 9:
  snapshot target.

Revision 10:
  Snapshot: Make calc_max_buckets return a constant 2M for now (need a
  proper fix for this).  [Chris Mason]

Revision 11:
  dm-exception-store: remove dead code. [Dave Olien]

Revision 12:
  mirror target.

Revision 13:
  Mirror: Exchange slow bit-by-bit count to use hweight32 to count bits per
  uint32_t. [AJ Lewis]

Revision 14:
  Mirror: flush the log as soon as a region is updated.  (Needs
  testing).

Revision 15:
  Flakey target

Revision 16:
  dm-zero