/* Find the max stripecount we should use */
__u16 lov_get_stripe_count(struct lov_obd *lov, __u32 magic, __u16 stripe_count)
{
	__u32 max_stripes = LOV_MAX_STRIPE_COUNT_OLD;

	if (!stripe_count)
		stripe_count = lov->desc.ld_default_stripe_count;
	if (stripe_count > lov->desc.ld_active_tgt_count)
		stripe_count = lov->desc.ld_active_tgt_count;
	if (!stripe_count)
		stripe_count = 1;

	/* stripe count is based on whether ldiskfs can handle
	 * larger EA sizes */
	if (lov->lov_ocd.ocd_connect_flags & OBD_CONNECT_MAX_EASIZE &&
	    lov->lov_ocd.ocd_max_easize)
		max_stripes = lov_mds_md_max_stripe_count(
			lov->lov_ocd.ocd_max_easize, magic);

	if (stripe_count > max_stripes)
		stripe_count = max_stripes;

	return stripe_count;
}
/* Pack LOV object metadata for disk storage.  It is packed in LE byte
 * order and is opaque to the networking layer.
 *
 * XXX In the future, this will be enhanced to get the EA size from the
 *     underlying OSC device(s) to get their EA sizes so we can stack
 *     LOVs properly.  For now lov_mds_md_size() just assumes one obd_id
 *     per stripe.
 */
int lov_packmd(struct obd_export *exp, struct lov_mds_md **lmmp,
	       struct lov_stripe_md *lsm)
{
	struct obd_device *obd = class_exp2obd(exp);
	struct lov_obd *lov = &obd->u.lov;
	struct lov_mds_md_v1 *lmmv1;
	struct lov_mds_md_v3 *lmmv3;
	__u16 stripe_count;
	struct lov_ost_data_v1 *lmm_objects;
	int lmm_size, lmm_magic;
	int i;
	int cplen = 0;

	if (lsm) {
		lmm_magic = lsm->lsm_magic;
	} else {
		if (lmmp && *lmmp)
			lmm_magic = le32_to_cpu((*lmmp)->lmm_magic);
		else
			/* lsm == NULL and lmmp == NULL */
			lmm_magic = LOV_MAGIC;
	}

	if ((lmm_magic != LOV_MAGIC_V1) &&
	    (lmm_magic != LOV_MAGIC_V3)) {
		CERROR("bad mem LOV MAGIC: 0x%08X != 0x%08X nor 0x%08X\n",
			lmm_magic, LOV_MAGIC_V1, LOV_MAGIC_V3);
		return -EINVAL;

	}

	if (lsm) {
		/* If we are just sizing the EA, limit the stripe count
		 * to the actual number of OSTs in this filesystem. */
		if (!lmmp) {
			stripe_count = lov_get_stripecnt(lov, lmm_magic,
							lsm->lsm_stripe_count);
			lsm->lsm_stripe_count = stripe_count;
		} else if (!lsm_is_released(lsm)) {
			stripe_count = lsm->lsm_stripe_count;
		} else {
			stripe_count = 0;
		}
	} else {
		/* No need to allocate more than maximum supported stripes.
		 * Anyway, this is pretty inaccurate since ld_tgt_count now
		 * represents max index and we should rely on the actual number
		 * of OSTs instead */
		stripe_count = lov_mds_md_max_stripe_count(
			lov->lov_ocd.ocd_max_easize, lmm_magic);

		if (stripe_count > lov->desc.ld_tgt_count)
			stripe_count = lov->desc.ld_tgt_count;
	}

	/* XXX LOV STACKING call into osc for sizes */
	lmm_size = lov_mds_md_size(stripe_count, lmm_magic);

	if (!lmmp)
		return lmm_size;

	if (*lmmp && !lsm) {
		stripe_count = le16_to_cpu((*lmmp)->lmm_stripe_count);
		lmm_size = lov_mds_md_size(stripe_count, lmm_magic);
		OBD_FREE_LARGE(*lmmp, lmm_size);
		*lmmp = NULL;
		return 0;
	}

	if (!*lmmp) {
		OBD_ALLOC_LARGE(*lmmp, lmm_size);
		if (!*lmmp)
			return -ENOMEM;
	}

	CDEBUG(D_INFO, "lov_packmd: LOV_MAGIC 0x%08X, lmm_size = %d \n",
	       lmm_magic, lmm_size);

	lmmv1 = *lmmp;
	lmmv3 = (struct lov_mds_md_v3 *)*lmmp;
	if (lmm_magic == LOV_MAGIC_V3)
		lmmv3->lmm_magic = cpu_to_le32(LOV_MAGIC_V3);
	else
		lmmv1->lmm_magic = cpu_to_le32(LOV_MAGIC_V1);

	if (!lsm)
		return lmm_size;

	/* lmmv1 and lmmv3 point to the same struct and have the
	 * same first fields
	 */
	lmm_oi_cpu_to_le(&lmmv1->lmm_oi, &lsm->lsm_oi);
	lmmv1->lmm_stripe_size = cpu_to_le32(lsm->lsm_stripe_size);
	lmmv1->lmm_stripe_count = cpu_to_le16(stripe_count);
	lmmv1->lmm_pattern = cpu_to_le32(lsm->lsm_pattern);
	lmmv1->lmm_layout_gen = cpu_to_le16(lsm->lsm_layout_gen);
	if (lsm->lsm_magic == LOV_MAGIC_V3) {
		cplen = strlcpy(lmmv3->lmm_pool_name, lsm->lsm_pool_name,
				sizeof(lmmv3->lmm_pool_name));
		if (cplen >= sizeof(lmmv3->lmm_pool_name))
			return -E2BIG;
		lmm_objects = lmmv3->lmm_objects;
	} else {
		lmm_objects = lmmv1->lmm_objects;
	}

	for (i = 0; i < stripe_count; i++) {
		struct lov_oinfo *loi = lsm->lsm_oinfo[i];
		/* XXX LOV STACKING call down to osc_packmd() to do packing */
		LASSERTF(ostid_id(&loi->loi_oi) != 0, "lmm_oi "DOSTID
			 " stripe %u/%u idx %u\n", POSTID(&lmmv1->lmm_oi),
			 i, stripe_count, loi->loi_ost_idx);
		ostid_cpu_to_le(&loi->loi_oi, &lmm_objects[i].l_ost_oi);
		lmm_objects[i].l_ost_gen = cpu_to_le32(loi->loi_ost_gen);
		lmm_objects[i].l_ost_idx = cpu_to_le32(loi->loi_ost_idx);
	}

	return lmm_size;
}