The changes as described in the commit message make good sense to me except for one thing:
In the 1.7 branch there is still a defined(__WINDOWS__) case for which opal_path_nfs() is currently a no-op . So, I fear that if CMR'ed blindly both the configure-time and build-time checks to ensure that at least one of statfs() or statvs() will abort the build on Windows. Maybe Marco can say more on the subject, but I think Cygwin will detect one or both of the stat calls, but opal_path_nfs() will still be a no-op due to the __WINDOWS__ guard.
I'll be building tonight's trunk tarball on all of my Solaris and *BSD systems. So, I can at least confirm that the code builds (finds at least one of statfs() or statvfs()) on each platform.
However, only my Solaris (10/SPARC and 11/x86-64) systems have NFS-mounted filesystems. So, I don't have any means to ensure that the "newly active" code performs correctly on the BSD systems. In other words, opal_path_nfs() might continue to always return false on BSD systems and I'd not know the difference.
P.S. the commit message says "modern flavors of *BSD OSs no longer define __BSD", but the FreeBSD-6.3 (circa 2008) system I also test doesn't define __BSD either. So, I wonder if this code ever did worked as intended on the BSD systems.