OK to expect O_SYNC?

[Guy Harris]

>I believe the O_SYNC flag is kept in the file descriptor table of the
>user structure and therefore only applies to that fd (or a dup of it) and
>not to other openings of that file descriptor (by the same process or
>by any other process.

Actually, it's kept in the file table entry, which is pointed to by
entries in the file descriptor table in the user structure.  As such, it
applies to that FD, any FDs duped from it, *and* any FDs inherited by
children of the process in which it was set (and their grandchildren,
etc.).  It doesn't apply to independent "open"s of the same file.