Hello,

Currently, libext2fs does not implement adding entry into htree directory. It
just bluntly clears EXT2_INDEX_FL and then treats the directory as non-indexed.
This breaks when metadata checksums are enabled and although ext2fs_link()
tries to fixup the directory, it doesn't always fixup all the checksums and
I have some doubts about practicality of just discarding htree information for
really large directories. This patch series implements full support for adding
entry into htree directory and some tests to test the functionality. The
first patch in the series is somewhat unrelated, it just clarifies handling
of overflown directory i_nlink handling in e2fsck which confused me initially
when analyzing the issue.

								Honza