zfs_probe_dev
if (zfs_probe_dev(devname, &guid, false) == 0)
zfs_probe_dev(devname, NULL, true);
zfs_probe_dev(devname, &pool_guid, true);
zfs_probe_dev(devname, NULL, true);
zfs_probe_dev(fn, &pool_uuid, false);
int zfs_probe_dev(const char *devname, uint64_t *pool_guid, bool part_too);
zfs_probe_dev(devname, &pool_guid, true);