On Fri, Aug 14, 2015 at 2:29 AM, David Drysdale [off-list ref] wrote:

On Fri, Aug 14, 2015 at 6:33 AM, Michael Kerrisk (man-pages)
[off-list ref] wrote:

quoted

On 13 August 2015 at 19:38, Andy Lutomirski [off-list ref] wrote:

quoted

On Thu, Aug 13, 2015 at 2:32 AM, David Drysdale [off-list ref] wrote:

quoted

Signed-off-by: David Drysdale <redacted>

What's the behavior wrt fcntl(F_GETFL, etc)?

I would presume that O_BENEATH is one of the so-called "file creation
flags". See this paragraph of the DESCRIPTION:

       In addition, zero or more file creation  flags  and  file  status
       flags  can be bitwise-or'd in flags.  The file creation flags are
       O_CLOEXEC, O_CREAT, O_DIRECTORY,  O_EXCL,  O_NOCTTY,  O_NOFOLLOW,
       O_TMPFILE,  O_TRUNC,  and  O_TTY_INIT.  The file status flags are
       all of the remaining flags listed below.  The distinction between
       these  two  groups  of flags is that the file status flags can be
       retrieved and (in some cases) modified; see fcntl(2) for details.

David, presuming this is correct (I can't see how O_BENEATH could be a
"file *status* flag"), your patch should also add O_BENEATH to the
list in that paragraph.

Yeah, O_BENEATH makes sense as a file creation flag; I'll add it
to that list -- thanks for spotting.

Should there be a test that you can't clear O_BENEATH with F_SETFL?

--Andy