[Linux PATCH] fcntl: add new F_OFD_*32 constants and handle them appropriately

[Jeff Layton]

On Thu, 2016-08-18 at 19:05 +0200, Christoph Hellwig wrote:
> NAK.  People should stop using 32-bit off_t and friends yesterday.
> It's a shame that glibc hasn't cought up with last century yet and
> stopped providing the non-LFS APIs for newly compiled code, but 
> we certainly should not bloat the kernel for the idiotic behavior.
> 
> In addition anyone is going to use a new Linux-only feature like the
> OFS locks should be using LFS support anyway.

That was my original thinking, but several people seemed to think that
we should just go ahead and support it. TBH, I don't much care either
way, but we either need to support it properly, or ensure that trying
to use OFD locks in a non-LFS program fails to compile.

The only real concern I have here is whether limiting this to LFS
enabled programs might make it tougher to get this into POSIX. Would
the POSIX standards folks object to having an interface like this that
doesn't support non-LFS cases? I guess if that ever happens though,
then we can just widen the support at that point.

If this is the consensus, then we can go with something like the glibc
patch I sent yesterday, which disables the command definitions when LFS
is not in effect.

Thoughts?
-- 
Jeff Layton <jlayton@redhat.com>