Pull ext4 updates from Ted Ts'o:
 "Added new ext4 debugging ioctls to allow userspace to get information
  about the state of the extent status cache.

  Dropped workaround for pre-1970 dates which were encoded incorrectly
  in pre-4.4 kernels. Since both the kernel correctly generates, and
  e2fsck detects and fixes this issue for the past four years, it'e time
  to drop the workaround. (Also, it's not like files with dates in the
  distant past were all that common in the first place.)

  A lot of miscellaneous bug fixes and cleanups, including some ext4
  Documentation fixes. Also included are two minor bug fixes in
  fs/unicode"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (21 commits)
  unicode: make array 'token' static const, makes object smaller
  unicode: Move static keyword to the front of declarations
  ext4: add missing bigalloc documentation.
  ext4: fix kernel oops caused by spurious casefold flag
  ext4: fix integer overflow when calculating commit interval
  ext4: use percpu_counters for extent_status cache hits/misses
  ext4: fix potential use after free after remounting with noblock_validity
  jbd2: add missing tracepoint for reserved handle
  ext4: fix punch hole for inline_data file systems
  ext4: rework reserved cluster accounting when invalidating pages
  ext4: documentation fixes
  ext4: treat buffers with write errors as containing valid data
  ext4: fix warning inside ext4_convert_unwritten_extents_endio
  ext4: set error return correctly when ext4_htree_store_dirent fails
  ext4: drop legacy pre-1970 encoding workaround
  ext4: add new ioctl EXT4_IOC_GET_ES_CACHE
  ext4: add a new ioctl EXT4_IOC_GETSTATE
  ext4: add a new ioctl EXT4_IOC_CLEAR_ES_CACHE
  jbd2: flush_descriptor(): Do not decrease buffer head's ref count
  ext4: remove unnecessary error check
  ...