The patch just got rebased, here's the one that was actually applied in master for v2.6.30: https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.g...

And yes, the code you highlighted is exactly this special-case in its current form. The mount option "noauto_da_alloc" can be used to disable these software-not-calling-fsync safety features.