> Aren't the edge cases features? What features do you have in mind? > It puts the choice of guaranteed writes vs performance to the developer. Yes, and it's

> Aren't the edge cases features? What features do you have in mind? > It puts the choice of guaranteed writes vs performance to the developer. Yes, and it's a completely false choice. This entire point of this thread is that fsync is an incredibly difficult API to use in a way that gets you the guarantees you need ("don't lose the writes to this file"). And that the consistency guarantees of specific filesystems, VFS, POSIX, and their interactions are not easy to understand even for the experienced -- and it can be catastrophic to get wrong. It isn't actually a choice between "Speed vs correctness". That's a nice fairy tale where people get to pretend they know what they're up against and everyone has full information. Most programmers aren't going to have the attention to get this right, even good ones. So then it's just "99.9% chance you fucked it up and it's wrong" and then your users are recovering data from backups.