Be there caches of not, I've found that I want to be able to say "I'm done with this file, let me know if everything is done and ok".
Of course, if you use 9p with no cache, you know you're done if all writes worked. If you have a cache, things may change. But either way, if you can check at close time you can be happy. if there's no cache, it'll always be ok; if there is, you might learn that you couldn't put the file in the server and do as you please. My argument is that I'd like the operation to be able to fail in general, and to be synchronous, so I could get an error status (despite caches being placed in the middle). After all, if you don't want to block in clunk you can either defer your closes or pass them to another process.
