/*
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2011, 2012, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 *
 * lustre/lov/lov_ea.c
 *
 * Author: Wang Di <wangdi@clusterfs.com>
 */

#define DEBUG_SUBSYSTEM S_LOV

#include <asm/div64.h>
#include <linux/libcfs/libcfs.h>

#include <obd_class.h>
#include <obd_lov.h>
#include <lustre/lustre_idl.h>

#include "lov_internal.h"

struct lovea_unpack_args {
	struct lov_stripe_md *lsm;
	int		   cursor;
};

static int lsm_lmm_verify_common(struct lov_mds_md *lmm, int lmm_bytes,
				 __u16 stripe_count)
{
	if (stripe_count > LOV_V1_INSANE_STRIPE_COUNT) {
		CERROR("bad stripe count %d\n", stripe_count);
		lov_dump_lmm_common(D_WARNING, lmm);
		return -EINVAL;
	}

	if (lmm_oi_id(&lmm->lmm_oi) == 0) {
		CERROR("zero object id\n");
		lov_dump_lmm_common(D_WARNING, lmm);
		return -EINVAL;
	}

	if (lov_pattern(le32_to_cpu(lmm->lmm_pattern)) != LOV_PATTERN_RAID0) {
		CERROR("bad striping pattern\n");
		lov_dump_lmm_common(D_WARNING, lmm);
		return -EINVAL;
	}

	if (lmm->lmm_stripe_size == 0 ||
	    (le32_to_cpu(lmm->lmm_stripe_size)&(LOV_MIN_STRIPE_SIZE-1)) != 0) {
		CERROR("bad stripe size %u\n",
		       le32_to_cpu(lmm->lmm_stripe_size));
		lov_dump_lmm_common(D_WARNING, lmm);
		return -EINVAL;
	}
	return 0;
}

struct lov_stripe_md *lsm_alloc_plain(__u16 stripe_count, int *size)
{
	struct lov_stripe_md *lsm;
	struct lov_oinfo     *loi;
	int		   i, oinfo_ptrs_size;

	LASSERT(stripe_count <= LOV_MAX_STRIPE_COUNT);

	oinfo_ptrs_size = sizeof(struct lov_oinfo *) * stripe_count;
	*size = sizeof(struct lov_stripe_md) + oinfo_ptrs_size;

	OBD_ALLOC_LARGE(lsm, *size);
	if (!lsm)
		return NULL;;

	for (i = 0; i < stripe_count; i++) {
		OBD_SLAB_ALLOC_PTR_GFP(loi, lov_oinfo_slab, __GFP_IO);
		if (loi == NULL)
			goto err;
		lsm->lsm_oinfo[i] = loi;
	}
	lsm->lsm_stripe_count = stripe_count;
	return lsm;

err:
	while (--i >= 0)
		OBD_SLAB_FREE(lsm->lsm_oinfo[i], lov_oinfo_slab, sizeof(*loi));
	OBD_FREE_LARGE(lsm, *size);
	return NULL;
}

void lsm_free_plain(struct lov_stripe_md *lsm)
{
	__u16 stripe_count = lsm->lsm_stripe_count;
	int i;

	for (i = 0; i < stripe_count; i++)
		OBD_SLAB_FREE(lsm->lsm_oinfo[i], lov_oinfo_slab,
			      sizeof(struct lov_oinfo));
	OBD_FREE_LARGE(lsm, sizeof(struct lov_stripe_md) +
		       stripe_count * sizeof(struct lov_oinfo *));
}

static void lsm_unpackmd_common(struct lov_stripe_md *lsm,
				struct lov_mds_md *lmm)
{
	/*
	 * This supposes lov_mds_md_v1/v3 first fields are
	 * are the same
	 */
	lmm_oi_le_to_cpu(&lsm->lsm_oi, &lmm->lmm_oi);
	lsm->lsm_stripe_size = le32_to_cpu(lmm->lmm_stripe_size);
	lsm->lsm_pattern = le32_to_cpu(lmm->lmm_pattern);
	lsm->lsm_layout_gen = le16_to_cpu(lmm->lmm_layout_gen);
	lsm->lsm_pool_name[0] = '\0';
}

static void
lsm_stripe_by_index_plain(struct lov_stripe_md *lsm, int *stripeno,
			   obd_off *lov_off, obd_off *swidth)
{
	if (swidth)
		*swidth = (obd_off)lsm->lsm_stripe_size * lsm->lsm_stripe_count;
}

static void
lsm_stripe_by_offset_plain(struct lov_stripe_md *lsm, int *stripeno,
			   obd_off *lov_off, obd_off *swidth)
{
	if (swidth)
		*swidth = (obd_off)lsm->lsm_stripe_size * lsm->lsm_stripe_count;
}

static int lsm_destroy_plain(struct lov_stripe_md *lsm, struct obdo *oa,
			     struct obd_export *md_exp)
{
	return 0;
}

/* Find minimum stripe maxbytes value.  For inactive or
 * reconnecting targets use LUSTRE_STRIPE_MAXBYTES. */
static void lov_tgt_maxbytes(struct lov_tgt_desc *tgt, __u64 *stripe_maxbytes)
{
	struct obd_import *imp = tgt->ltd_obd->u.cli.cl_import;

	if (imp == NULL || !tgt->ltd_active) {
		*stripe_maxbytes = LUSTRE_STRIPE_MAXBYTES;
		return;
	}

	spin_lock(&imp->imp_lock);
	if (imp->imp_state == LUSTRE_IMP_FULL &&
	    (imp->imp_connect_data.ocd_connect_flags & OBD_CONNECT_MAXBYTES) &&
	    imp->imp_connect_data.ocd_maxbytes > 0) {
		if (*stripe_maxbytes > imp->imp_connect_data.ocd_maxbytes)
			*stripe_maxbytes = imp->imp_connect_data.ocd_maxbytes;
	} else {
		*stripe_maxbytes = LUSTRE_STRIPE_MAXBYTES;
	}
	spin_unlock(&imp->imp_lock);
}

static int lsm_lmm_verify_v1(struct lov_mds_md_v1 *lmm, int lmm_bytes,
			     __u16 *stripe_count)
{
	if (lmm_bytes < sizeof(*lmm)) {
		CERROR("lov_mds_md_v1 too small: %d, need at least %d\n",
		       lmm_bytes, (int)sizeof(*lmm));
		return -EINVAL;
	}

	*stripe_count = le16_to_cpu(lmm->lmm_stripe_count);
	if (le32_to_cpu(lmm->lmm_pattern) & LOV_PATTERN_F_RELEASED)
		*stripe_count = 0;

	if (lmm_bytes < lov_mds_md_size(*stripe_count, LOV_MAGIC_V1)) {
		CERROR("LOV EA V1 too small: %d, need %d\n",
		       lmm_bytes, lov_mds_md_size(*stripe_count, LOV_MAGIC_V1));
		lov_dump_lmm_common(D_WARNING, lmm);
		return -EINVAL;
	}

	return lsm_lmm_verify_common(lmm, lmm_bytes, *stripe_count);
}

int lsm_unpackmd_v1(struct lov_obd *lov, struct lov_stripe_md *lsm,
		    struct lov_mds_md_v1 *lmm)
{
	struct lov_oinfo *loi;
	int i;
	int stripe_count;
	__u64 stripe_maxbytes = OBD_OBJECT_EOF;

	lsm_unpackmd_common(lsm, lmm);

	stripe_count = lsm_is_released(lsm) ? 0 : lsm->lsm_stripe_count;

	for (i = 0; i < stripe_count; i++) {
		/* XXX LOV STACKING call down to osc_unpackmd() */
		loi = lsm->lsm_oinfo[i];
		ostid_le_to_cpu(&lmm->lmm_objects[i].l_ost_oi, &loi->loi_oi);
		loi->loi_ost_idx = le32_to_cpu(lmm->lmm_objects[i].l_ost_idx);
		loi->loi_ost_gen = le32_to_cpu(lmm->lmm_objects[i].l_ost_gen);
		if (loi->loi_ost_idx >= lov->desc.ld_tgt_count) {
			CERROR("OST index %d more than OST count %d\n",
			       loi->loi_ost_idx, lov->desc.ld_tgt_count);
			lov_dump_lmm_v1(D_WARNING, lmm);
			return -EINVAL;
		}
		if (!lov->lov_tgts[loi->loi_ost_idx]) {
			CERROR("OST index %d missing\n", loi->loi_ost_idx);
			lov_dump_lmm_v1(D_WARNING, lmm);
			return -EINVAL;
		}
		/* calculate the minimum stripe max bytes */
		lov_tgt_maxbytes(lov->lov_tgts[loi->loi_ost_idx],
				 &stripe_maxbytes);
	}

	lsm->lsm_maxbytes = stripe_maxbytes * lsm->lsm_stripe_count;
	if (lsm->lsm_stripe_count == 0)
		lsm->lsm_maxbytes = stripe_maxbytes * lov->desc.ld_tgt_count;

	return 0;
}

const struct lsm_operations lsm_v1_ops = {
	.lsm_free	    = lsm_free_plain,
	.lsm_destroy	 = lsm_destroy_plain,
	.lsm_stripe_by_index    = lsm_stripe_by_index_plain,
	.lsm_stripe_by_offset   = lsm_stripe_by_offset_plain,
	.lsm_lmm_verify	 = lsm_lmm_verify_v1,
	.lsm_unpackmd	   = lsm_unpackmd_v1,
};

static int lsm_lmm_verify_v3(struct lov_mds_md *lmmv1, int lmm_bytes,
			     __u16 *stripe_count)
{
	struct lov_mds_md_v3 *lmm;

	lmm = (struct lov_mds_md_v3 *)lmmv1;

	if (lmm_bytes < sizeof(*lmm)) {
		CERROR("lov_mds_md_v3 too small: %d, need at least %d\n",
		       lmm_bytes, (int)sizeof(*lmm));
		return -EINVAL;
	}

	*stripe_count = le16_to_cpu(lmm->lmm_stripe_count);
	if (le32_to_cpu(lmm->lmm_pattern) & LOV_PATTERN_F_RELEASED)
		*stripe_count = 0;

	if (lmm_bytes < lov_mds_md_size(*stripe_count, LOV_MAGIC_V3)) {
		CERROR("LOV EA V3 too small: %d, need %d\n",
		       lmm_bytes, lov_mds_md_size(*stripe_count, LOV_MAGIC_V3));
		lov_dump_lmm_common(D_WARNING, lmm);
		return -EINVAL;
	}

	return lsm_lmm_verify_common((struct lov_mds_md_v1 *)lmm, lmm_bytes,
				     *stripe_count);
}

int lsm_unpackmd_v3(struct lov_obd *lov, struct lov_stripe_md *lsm,
		    struct lov_mds_md *lmmv1)
{
	struct lov_mds_md_v3 *lmm;
	struct lov_oinfo *loi;
	int i;
	int stripe_count;
	__u64 stripe_maxbytes = OBD_OBJECT_EOF;
	int cplen = 0;

	lmm = (struct lov_mds_md_v3 *)lmmv1;

	lsm_unpackmd_common(lsm, (struct lov_mds_md_v1 *)lmm);

	stripe_count = lsm_is_released(lsm) ? 0 : lsm->lsm_stripe_count;

	cplen = strlcpy(lsm->lsm_pool_name, lmm->lmm_pool_name,
			sizeof(lsm->lsm_pool_name));
	if (cplen >= sizeof(lsm->lsm_pool_name))
		return -E2BIG;

	for (i = 0; i < stripe_count; i++) {
		/* XXX LOV STACKING call down to osc_unpackmd() */
		loi = lsm->lsm_oinfo[i];
		ostid_le_to_cpu(&lmm->lmm_objects[i].l_ost_oi, &loi->loi_oi);
		loi->loi_ost_idx = le32_to_cpu(lmm->lmm_objects[i].l_ost_idx);
		loi->loi_ost_gen = le32_to_cpu(lmm->lmm_objects[i].l_ost_gen);
		if (loi->loi_ost_idx >= lov->desc.ld_tgt_count) {
			CERROR("OST index %d more than OST count %d\n",
			       loi->loi_ost_idx, lov->desc.ld_tgt_count);
			lov_dump_lmm_v3(D_WARNING, lmm);
			return -EINVAL;
		}
		if (!lov->lov_tgts[loi->loi_ost_idx]) {
			CERROR("OST index %d missing\n", loi->loi_ost_idx);
			lov_dump_lmm_v3(D_WARNING, lmm);
			return -EINVAL;
		}
		/* calculate the minimum stripe max bytes */
		lov_tgt_maxbytes(lov->lov_tgts[loi->loi_ost_idx],
				 &stripe_maxbytes);
	}

	lsm->lsm_maxbytes = stripe_maxbytes * lsm->lsm_stripe_count;
	if (lsm->lsm_stripe_count == 0)
		lsm->lsm_maxbytes = stripe_maxbytes * lov->desc.ld_tgt_count;

	return 0;
}

const struct lsm_operations lsm_v3_ops = {
	.lsm_free	    = lsm_free_plain,
	.lsm_destroy	 = lsm_destroy_plain,
	.lsm_stripe_by_index    = lsm_stripe_by_index_plain,
	.lsm_stripe_by_offset   = lsm_stripe_by_offset_plain,
	.lsm_lmm_verify	 = lsm_lmm_verify_v3,
	.lsm_unpackmd	   = lsm_unpackmd_v3,
};