On Sat, Feb 27, 2021 at 07:25:00PM -0500, Drew DeVault wrote: > This introduces mkdirat2, along with the requisite flag argument, which > presently accepts the same flags as open - allowing the caller to > specify, say, O_CLOEXEC - and leaving us room to expand the next time an > unforeseeable addition to mkdir is called for. Otherwise, it behaves > identically to mkdirat, but returns an open file descriptor for the new > directory. No to the ABI part; "on error it returns -E..., on success - 0 or a non-negative number representing a file descriptor (zero also possible, but unlikely)" is bloody awful as calling conventions go, especially since the case when 0 happens to be a descriptor is not going to get a lot of testing on the userland side. Don't mix "return an error or descriptor" with "return an error or 0". It's going to end up a regular source of userland bugs.
