The curious case of O_DIRECTORY|O_CREAT

Uhm, it was not secret at any point. Moreover, MS was pushing it pretty hard around the Vista time. The API was actually pretty cool, you could even do distributed transactions (using the Microsoft Distributed Transaction Coordinator) that involved the filesystem and SQL server. We used it to do transactional file operations in our CRM running under the IIS.

There were some problems with it:
1. It was slow as hell. NTFS is not a speed daemon in the best of times, and additional journaling slowed it down even more.
2. Pretty much nobody used it, even Microsoft's own Windows Update. So it got dropped from the ReFS.