Merge branch 'chromeos-verity-3.4' into chromeos-3.4

Merge branch 'chromeos-verity-3.4' into chromeos-3.4

By Mandeep Singh Baines (21) and others
* chromeos-verity-3.4: (48 commits)
  CHROMIUM: verity: Add stats on block sizes
  CHROMIUM: verity: Add a debugfs interface with basic stats access
  CHROMIUM: verity: Add a few comments about the statistics variables
  CHROMIUM: verity: Add a name for each verity instance
  CHROMIUM: verity: make total_requeues a uint64
  CHROMIUM: verity: honor optional salt argument.
  CHROMIUM: dm-bht: add salt support.
  CHROMIUM: init: don't dm_substitute_devices().
  CHROMIUM: verity: embed hash_desc instead of allocating it
  CHROMIUM: verity: use one shared queue per processer
  CHROMIUM: dm-verity: optionally support key-val args
  CHROMIUM: verity: use alloc_page instead of mempool_alloc
  CHROMIUM: verity: convert depth to an int
  CHROMIUM: verity: statically allocate root_digest
  CHROMIUM: verity: use block instead of block_index everywhere
  CHROMIUM: verity: short-circuit dm_bht_populate
  CHROMIUM: verity: cleanup commenting of io_bht_populate
  CHROMIUM: verity: change type (u64) for io block and count
  CHROMIUM: verity: root hash should not rely on uninitialized memory
  CHROMIUM: verity: use high priority workqueues
  ...