[$] Reconsidering O_CREAT|O_DIRECTORY

Linux provides a system call ( 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.