Pull ext4 updates from Ted Ts'o:
 "Various cleanups and bug fixes in ext4's extent status tree,
  journalling, and block allocator subsystems.

  Also improve performance for parallel DIO overwrites"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (55 commits)
  ext4: avoid updating the superblock on a r/o mount if not needed
  jbd2: skip reading super block if it has been verified
  ext4: fix to check return value of freeze_bdev() in ext4_shutdown()
  ext4: refactoring to use the unified helper ext4_quotas_off()
  ext4: turn quotas off if mount failed after enabling quotas
  ext4: update doc about journal superblock description
  ext4: add journal cycled recording support
  jbd2: continue to record log between each mount
  jbd2: remove j_format_version
  jbd2: factor out journal initialization from journal_get_superblock()
  jbd2: switch to check format version in superblock directly
  jbd2: remove unused feature macros
  ext4: ext4_put_super: Remove redundant checking for 'sbi->s_journal_bdev'
  ext4: Fix reusing stale buffer heads from last failed mounting
  ext4: allow concurrent unaligned dio overwrites
  ext4: clean up mballoc criteria comments
  ext4: make ext4_zeroout_es() return void
  ext4: make ext4_es_insert_extent() return void
  ext4: make ext4_es_insert_delayed_block() return void
  ext4: make ext4_es_remove_extent() return void
  ...