This patch adds a new option '-D' to mkfs to allow creating ext4 filesystem.

  lib/ext2fs/ext2_fs.h    |    7 +++++++
  lib/ext2fs/initialize.c |    1 +
  misc/mke2fs.c           |   18 ++++++++++++++++--
  3 files changed, 24 insertions(+), 2 deletions(-)