Revision 1:
  Fix minor number allocation check: (1 << MINORBITS) is invalid.
  
  [Accepted upstream.]

Revision 2:
  Rename EMIT macro to DMEMIT.
  
  [Accepted upstream.]

Revision 3:
  Make mirror log synchronization optional.  [HM]
  
  [Accepted upstream.]

Revision 4:
  Multipath target - original version.

Revision 5:
  DM_TARGET_MSG ioctl

Revision 6:
  Flakey target

Revision 7:
  dm-multipath: ps-refcount.patch
  Fixes the refcounting on the path-selectors. And, exports the
  register/unregister functions.
  
  From: Mike Christie <mikenc@us.ibm.com>

Revision 8:
  Some variable renaming.
  pg.ps no longer pointer.

Revision 9:
  More variable renaming.

Revision 10:
  Missing sz update in status
  Missing dm_put_path_selector
  Missing statics

Revision 11:
  Revert info->map_context

Revision 12:
  Path selector select fn returns how many times to re-use the path.

Revision 13:
  Add reinstate_path function (unused).

Revision 14:
  Separate out round-robin path selector.

Revision 15:
  Remove duplicate kfree in dm_register_target.

Revision 16:
  Make round-robin repeat count per-path.

Revision 17:
  Clear rr context pointer after object is freed.

Revision 18:
  If path selector name unrecognised, attempt to load module with that name.

Revision 19:
  Update multipath version.

Revision 20:
  Change message ioctl to use argc/argv;
  Remove test implementation from dm-zero;
  Add reinstate message to dm-mpath.

Revision 21:
  dm_get_by_dev()

Revision 22:
  Pass bdev to path selector so it can take account of device characteristics
  if it wishes.

Revision 23:
  Ioctl interface accepts refs by device number, not just name or uuid.

Revision 24:
  tidy

Revision 25:
  Interface version 4.3.0 (for reference by device number).

Revision 26:
  kgdb