On-disk format definition for huge files

- EXT4_FEATURE_RO_COMPAT_HUGE_FILE (0x0008) - change i_blocks to be
  in units of s_blocksize units instead of 512-byte sectors, use
  l_i_frag and l_i_fsize as i_blocks_hi (could also be part of 64BIT).

E2fsck and debugfs changed to support i_blocks_hi instead of l_i_frag and
l_i_fsize.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
13 files changed