Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  Define/reserve new ext4 superblock fields
  When ext4_ext_insert_extent() fails to insert new blocks
  ext4: Extent overlap bugfix
  Remove unnecessary exported symbols.
  EXT4: Fix whitespace