In arch/alpha/alpha/disksubr.c - in setdisklabel() the code around
line 178 is ...

        if (nlp->d_magic != DISKMAGIC || nlp->d_magic2 != DISKMAGIC ||
                dkcksum(nlp) != 0)
                return (EINVAL);

        while ((i = ffs((long)openmask)) != 0) {
                i--;
                openmask &= ~(1 << i);
                if (nlp->d_npartitions <= i)
                        return (EBUSY);

The query is that "(long)" cast.  Why?   openmask is u_long, ffs takes
an int arg, according to libkern.h, what is going on there?

I suspect historical baggage that should be cleaned up - but if the alpha
does have an ffs() that takes a long, rather than an int, then something
probably needs to happen to libkern.h

kre