Linux provides a system call (mkdir()) to create a directory, and a few variants of open() that can open a directory. There is, however, no system call in Linux that can create and open a directory in a single, race-free call. Jori Koolstra has been working on remedying that situation, most recently by repurposing a set of open() flags that currently return an error. There are, however, concerns that show just how hard it can be to create user-space interfaces that do not present traps for application developers.