On Fri, Mar 13, 2020 at 08:59:01PM +1100, Aleksa Sarai wrote:

I have heard some folks asking for a way to create a directory and get a
handle to it atomically -- so arguably this is something that could be
inside openat2()'s feature set (O_MKDIR?). But I'm not sure how popular
of an idea this is.

This would be very useful to prevent race conditions between making
a directory and EA's on it, as are needed by Samba for
DOS attributes and Windows/NFSv4 ACLS.