zfs_statfs(vfs_t *vfsp, struct statfs *statp)
{
...
        /*
         * statvfs() should really be called statufs(), because it assumes
         * static metadata.  ZFS doesn't preallocate files, so the best
         * we can do is report the max that could possibly fit in f_files,
         * and that minus the number actually used in f_ffree.
         * For f_ffree, report the smaller of the number of object available
         * and the number of blocks (each object will take at least a block).
         */
        statp->f_ffree = MIN(availobjs, statp->f_bfree);
        statp->f_files = statp->f_ffree + usedobjs;