ffs_alloccg
bno = ffs_hashalloc(ip, cg, bpref, size, ffs_alloccg);
bno = ffs_hashalloc(ip, cg, bpref, request, ffs_alloccg);
daddr_t ffs_alloccg(struct inode *, u_int, daddr_t, int);
bno = ffs_hashalloc(ip, cg, bpref, size, ffs_alloccg);
static daddr_t ffs_alloccg(struct inode *, int, daddr_t, int);