> Okay ... we can fall back to O_FSYNC if we don't see either of the
> others. No problem. Any other weird cases out there? I think Andreas
> might've muttered something about AIX but I'm not sure now.
You can safely use O_DSYNC on AIX, the only special on AIX is,
that it does not make a speed difference to O_SYNC. This is imho
because the jfs only needs one sync write to the jfs journal for meta info
in eighter case (so that nobody misunderstands: both perform excellent).
Andreas