This is hard only on GNU/Linux because it's inherently broken because solving this once and for all proved too hard of a problem for volunteers working on the k

This is hard only on GNU/Linux because it's inherently broken because solving this once and for all proved too hard of a problem for volunteers working on the kernel and filesystem code. That's a hard to swallow fact if one's favorite operating system is GNU/Linux. There is one group of people who did solve it and they solved it correctly: the ZFS team under Jeff Bonwick. If you care about data integrity, if you need an operating system where filesystem operations aren't leaky abstractions and where fsync(2) works as POSIX specifies, if correctness of operation is important to you, use an illumos-based operating system like SmartOS or any other based on the illumos codebase. Put some effort in and learn real UNIX and leave these long ago solved problems where they belong, back in the past century.