Pull ext4 bug fixes from Ted Ts'o:
 "The following are all bug fixes and regressions.  The most notable are
  the ones which cause problems for ext4 on RAID --- a performance
  problem when mounting very large filesystems, and a kernel OOPS when
  doing an rm -rf on large directory hierarchies on fast devices."

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix kernel BUG on large-scale rm -rf commands
  ext4: fix long mount times on very big file systems
  ext4: don't call ext4_error while block group is locked
  ext4: avoid kmemcheck complaint from reading uninitialized memory
  ext4: make sure the journal sb is written in ext4_clear_journal_err()