A different groups descriptor structure was introduced for ext4 filesystems.
This patch handles that.

  debugfs/debugfs.c    |    9 +++++++++
  debugfs/set_fields.c |    4 ++++
  e2fsck/super.c       |    4 ++++
  lib/ext2fs/closefs.c |    5 +++++
  lib/ext2fs/ext2fs.h  |    8 ++++++++
  lib/ext2fs/openfs.c  |    7 ++++++-
  lib/ext2fs/swapfs.c  |    4 ++++
  misc/mke2fs.c        |    4 ++++
  resize/resize2fs.c   |    2 +-
  9 files changed, 45 insertions(+), 2 deletions(-)