Pull ext4 fixes from Ted Ts'o:
 "Various bug fixes for ext4.  The most serious of them fixes a security
  bug (CVE-2012-4508) which leads to stale data exposure when we have
  fallocate racing against writes to files undergoing delayed
  allocation.  We also have two fixes for the metadata checksum feature,
  the most serious of which can cause the superblock to have a invalid
  checksum after a power failure."

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: Avoid underflow in ext4_trim_fs()
  ext4: Checksum the block bitmap properly with bigalloc enabled
  ext4: fix undefined bit shift result in ext4_fill_flex_info
  ext4: fix metadata checksum calculation for the superblock
  ext4: race-condition protection for ext4_convert_unwritten_extents_endio
  ext4: serialize fallocate with ext4_convert_unwritten_extents