The problem is, Apple's fsync doesn't even introduce any useful semantics. All it says is "write this eventually". What a lot of people really need is just a "

The problem is, Apple's fsync doesn't even introduce any useful semantics. All it says is "write this eventually". What a lot of people really need is just a "provide ordering, don't leave me with inconsistent data" operation. If you lose power "after" a write but before the fsync, for any non-networked application that's no different than losing power before the write, as long as the filesystem doesn't introduce chaos.