I don't think the name of the flag is appropriate.  Calling it NOEXPORT is 
putting NFS-specific terminology into tmpfs; it would be better to keep 
them separate, and to say more clearly (in tmpfs) what capability is 
missing and (in nfs) what capability is needed.

The capability in question is persistent/unique filehandles.  I'm not sure 
how to make that short enough-- NOHANDLES?

Also, when I look in fstypes.h, I'd say that this limitation is more like 
those in the MNT_BASIC_FLAGS set (e.g., READONLY, NOATIME) than the IMNT_* 
set.

 	Cary Gray