Thanks for mentioning those options. I found a little more about the in the ext4 manpage.
Things about it a little more, I'd expect I could skip the first directory fsync I'd mentioned. Surely the rename can't make it to the directory without the creation getting there, too...
Anyway, I feel like I've could come up with a list of questions 10x as long as the one I just gave, but you'd never really get answers, even for a particular drive, os, fs combo, without expensive testing or source code digging.
But in the end you should code against what posix guarantees, not what particular filesystems happen to do, because the next filesystem might use some other leeway the spec provides.
Things about it a little more, I'd expect I could skip the first directory fsync I'd mentioned. Surely the rename can't make it to the directory without the creation getting there, too...
Anyway, I feel like I've could come up with a list of questions 10x as long as the one I just gave, but you'd never really get answers, even for a particular drive, os, fs combo, without expensive testing or source code digging.