/*
 * 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.gnu.org/licenses/gpl-2.0.html
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2011, 2015, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 *
 * lustre/lov/lov_pack.c
 *
 * (Un)packing of OST/MDS requests
 *
 * Author: Andreas Dilger <adilger@clusterfs.com>
 */

#define DEBUG_SUBSYSTEM S_LOV

#include "../include/lustre/lustre_idl.h"
#include "../include/lustre/lustre_user.h"

#include "../include/lustre_net.h"
#include "../include/lustre_swab.h"
#include "../include/obd.h"
#include "../include/obd_class.h"
#include "../include/obd_support.h"

#include "lov_cl_internal.h"
#include "lov_internal.h"

void lov_dump_lmm_common(int level, void *lmmp)
{
	struct lov_mds_md *lmm = lmmp;
	struct ost_id	oi;

	lmm_oi_le_to_cpu(&oi, &lmm->lmm_oi);
	CDEBUG(level, "objid " DOSTID ", magic 0x%08x, pattern %#x\n",
	       POSTID(&oi), le32_to_cpu(lmm->lmm_magic),
	       le32_to_cpu(lmm->lmm_pattern));
	CDEBUG(level, "stripe_size %u, stripe_count %u, layout_gen %u\n",
	       le32_to_cpu(lmm->lmm_stripe_size),
	       le16_to_cpu(lmm->lmm_stripe_count),
	       le16_to_cpu(lmm->lmm_layout_gen));
}

static void lov_dump_lmm_objects(int level, struct lov_ost_data *lod,
				 int stripe_count)
{
	int i;

	if (stripe_count > LOV_V1_INSANE_STRIPE_COUNT) {
		CDEBUG(level, "bad stripe_count %u > max_stripe_count %u\n",
		       stripe_count, LOV_V1_INSANE_STRIPE_COUNT);
		return;
	}

	for (i = 0; i < stripe_count; ++i, ++lod) {
		struct ost_id	oi;

		ostid_le_to_cpu(&lod->l_ost_oi, &oi);
		CDEBUG(level, "stripe %u idx %u subobj " DOSTID "\n", i,
		       le32_to_cpu(lod->l_ost_idx), POSTID(&oi));
	}
}

void lov_dump_lmm_v1(int level, struct lov_mds_md_v1 *lmm)
{
	lov_dump_lmm_common(level, lmm);
	lov_dump_lmm_objects(level, lmm->lmm_objects,
			     le16_to_cpu(lmm->lmm_stripe_count));
}

void lov_dump_lmm_v3(int level, struct lov_mds_md_v3 *lmm)
{
	lov_dump_lmm_common(level, lmm);
	CDEBUG(level, "pool_name " LOV_POOLNAMEF "\n", lmm->lmm_pool_name);
	lov_dump_lmm_objects(level, lmm->lmm_objects,
			     le16_to_cpu(lmm->lmm_stripe_count));
}

/**
 * Pack LOV striping metadata for disk storage format (in little
 * endian byte order).
 *
 * This follows the getxattr() conventions. If \a buf_size is zero
 * then return the size needed. If \a buf_size is too small then
 * return -ERANGE. Otherwise return the size of the result.
 */
ssize_t lov_lsm_pack(const struct lov_stripe_md *lsm, void *buf,
		     size_t buf_size)
{
	struct lov_ost_data_v1 *lmm_objects;
	struct lov_mds_md_v1 *lmmv1 = buf;
	struct lov_mds_md_v3 *lmmv3 = buf;
	size_t lmm_size;
	unsigned int i;

	lmm_size = lov_mds_md_size(lsm->lsm_stripe_count, lsm->lsm_magic);
	if (!buf_size)
		return lmm_size;

	if (buf_size < lmm_size)
		return -ERANGE;

	/*
	 * lmmv1 and lmmv3 point to the same struct and have the
	 * same first fields
	 */
	lmmv1->lmm_magic = cpu_to_le32(lsm->lsm_magic);
	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(lsm->lsm_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) {
		BUILD_BUG_ON(sizeof(lsm->lsm_pool_name) !=
			 sizeof(lmmv3->lmm_pool_name));
		strlcpy(lmmv3->lmm_pool_name, lsm->lsm_pool_name,
			sizeof(lmmv3->lmm_pool_name));
		lmm_objects = lmmv3->lmm_objects;
	} else {
		lmm_objects = lmmv1->lmm_objects;
	}

	for (i = 0; i < lsm->lsm_stripe_count; i++) {
		struct lov_oinfo *loi = lsm->lsm_oinfo[i];

		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;
}

/* Find the max stripecount we should use */
__u16 lov_get_stripecnt(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;
}

static int lov_verify_lmm(void *lmm, int lmm_bytes, __u16 *stripe_count)
{
	int rc;

	if (!lsm_op_find(le32_to_cpu(*(__u32 *)lmm))) {
		CERROR("bad disk LOV MAGIC: 0x%08X; dumping LMM (size=%d):\n",
		       le32_to_cpu(*(__u32 *)lmm), lmm_bytes);
		CERROR("%*phN\n", lmm_bytes, lmm);
		return -EINVAL;
	}
	rc = lsm_op_find(le32_to_cpu(*(__u32 *)lmm))->lsm_lmm_verify(lmm,
								     lmm_bytes,
								  stripe_count);
	return rc;
}

static struct lov_stripe_md *lov_lsm_alloc(u16 stripe_count, u32 pattern,
					   u32 magic)
{
	struct lov_stripe_md *lsm;
	unsigned int i;

	CDEBUG(D_INFO, "alloc lsm, stripe_count %u\n", stripe_count);

	lsm = lsm_alloc_plain(stripe_count);
	if (!lsm) {
		CERROR("cannot allocate LSM stripe_count %u\n", stripe_count);
		return ERR_PTR(-ENOMEM);
	}

	atomic_set(&lsm->lsm_refc, 1);
	spin_lock_init(&lsm->lsm_lock);
	lsm->lsm_magic = magic;
	lsm->lsm_stripe_count = stripe_count;
	lsm->lsm_maxbytes = LUSTRE_EXT3_STRIPE_MAXBYTES * stripe_count;
	lsm->lsm_pattern = pattern;
	lsm->lsm_pool_name[0] = '\0';
	lsm->lsm_layout_gen = 0;
	if (stripe_count > 0)
		lsm->lsm_oinfo[0]->loi_ost_idx = ~0;

	for (i = 0; i < stripe_count; i++)
		loi_init(lsm->lsm_oinfo[i]);

	return lsm;
}

int lov_free_memmd(struct lov_stripe_md **lsmp)
{
	struct lov_stripe_md *lsm = *lsmp;
	int refc;

	*lsmp = NULL;
	LASSERT(atomic_read(&lsm->lsm_refc) > 0);
	refc = atomic_dec_return(&lsm->lsm_refc);
	if (refc == 0)
		lsm_op_find(lsm->lsm_magic)->lsm_free(lsm);

	return refc;
}

/* Unpack LOV object metadata from disk storage.  It is packed in LE byte
 * order and is opaque to the networking layer.
 */
struct lov_stripe_md *lov_unpackmd(struct lov_obd *lov, struct lov_mds_md *lmm,
				   size_t lmm_size)
{
	struct lov_stripe_md *lsm;
	u16 stripe_count;
	u32 pattern;
	u32 magic;
	int rc;

	rc = lov_verify_lmm(lmm, lmm_size, &stripe_count);
	if (rc)
		return ERR_PTR(rc);

	magic = le32_to_cpu(lmm->lmm_magic);
	pattern = le32_to_cpu(lmm->lmm_pattern);

	lsm = lov_lsm_alloc(stripe_count, pattern, magic);
	if (IS_ERR(lsm))
		return lsm;

	LASSERT(lsm_op_find(magic));
	rc = lsm_op_find(magic)->lsm_unpackmd(lov, lsm, lmm);
	if (rc) {
		lov_free_memmd(&lsm);
		return ERR_PTR(rc);
	}

	return lsm;
}

/* Retrieve object striping information.
 *
 * @lump is a pointer to an in-core struct with lmm_ost_count indicating
 * the maximum number of OST indices which will fit in the user buffer.
 * lmm_magic must be LOV_USER_MAGIC.
 */
int lov_getstripe(struct lov_object *obj, struct lov_stripe_md *lsm,
		  struct lov_user_md __user *lump)
{
	/* we use lov_user_md_v3 because it is larger than lov_user_md_v1 */
	struct lov_user_md_v3 lum;
	struct lov_mds_md *lmmk;
	u32 stripe_count;
	ssize_t lmm_size;
	size_t lmmk_size;
	size_t lum_size;
	int rc;

	if (!lsm)
		return -ENODATA;

	if (lsm->lsm_magic != LOV_MAGIC_V1 && lsm->lsm_magic != LOV_MAGIC_V3) {
		CERROR("bad LSM MAGIC: 0x%08X != 0x%08X nor 0x%08X\n",
		       lsm->lsm_magic, LOV_MAGIC_V1, LOV_MAGIC_V3);
		rc = -EIO;
		goto out;
	}

	if (!lsm_is_released(lsm))
		stripe_count = lsm->lsm_stripe_count;
	else
		stripe_count = 0;

	/* we only need the header part from user space to get lmm_magic and
	 * lmm_stripe_count, (the header part is common to v1 and v3)
	 */
	lum_size = sizeof(struct lov_user_md_v1);
	if (copy_from_user(&lum, lump, lum_size)) {
		rc = -EFAULT;
		goto out;
	}
	if (lum.lmm_magic != LOV_USER_MAGIC_V1 &&
	    lum.lmm_magic != LOV_USER_MAGIC_V3 &&
	    lum.lmm_magic != LOV_USER_MAGIC_SPECIFIC) {
		rc = -EINVAL;
		goto out;
	}

	if (lum.lmm_stripe_count &&
	    (lum.lmm_stripe_count < lsm->lsm_stripe_count)) {
		/* Return right size of stripe to user */
		lum.lmm_stripe_count = stripe_count;
		rc = copy_to_user(lump, &lum, lum_size);
		rc = -EOVERFLOW;
		goto out;
	}
	lmmk_size = lov_mds_md_size(stripe_count, lsm->lsm_magic);


	lmmk = libcfs_kvzalloc(lmmk_size, GFP_NOFS);
	if (!lmmk) {
		rc = -ENOMEM;
		goto out;
	}

	lmm_size = lov_lsm_pack(lsm, lmmk, lmmk_size);
	if (lmm_size < 0) {
		rc = lmm_size;
		goto out_free;
	}

	/* FIXME: Bug 1185 - copy fields properly when structs change */
	/* struct lov_user_md_v3 and struct lov_mds_md_v3 must be the same */
	BUILD_BUG_ON(sizeof(lum) != sizeof(struct lov_mds_md_v3));
	BUILD_BUG_ON(sizeof(lum.lmm_objects[0]) != sizeof(lmmk->lmm_objects[0]));

	if (cpu_to_le32(LOV_MAGIC) != LOV_MAGIC &&
	    (lmmk->lmm_magic == cpu_to_le32(LOV_MAGIC_V1) ||
	     lmmk->lmm_magic == cpu_to_le32(LOV_MAGIC_V3))) {
		lustre_swab_lov_mds_md(lmmk);
		lustre_swab_lov_user_md_objects(
				(struct lov_user_ost_data *)lmmk->lmm_objects,
				lmmk->lmm_stripe_count);
	}

	if (lum.lmm_magic == LOV_USER_MAGIC) {
		/* User request for v1, we need skip lmm_pool_name */
		if (lmmk->lmm_magic == LOV_MAGIC_V3) {
			memmove(((struct lov_mds_md_v1 *)lmmk)->lmm_objects,
				((struct lov_mds_md_v3 *)lmmk)->lmm_objects,
				lmmk->lmm_stripe_count *
				sizeof(struct lov_ost_data_v1));
			lmm_size -= LOV_MAXPOOLNAME;
		}
	} else {
		/* if v3 we just have to update the lum_size */
		lum_size = sizeof(struct lov_user_md_v3);
	}

	/* User wasn't expecting this many OST entries */
	if (lum.lmm_stripe_count == 0) {
		lmm_size = lum_size;
	} else if (lum.lmm_stripe_count < lmmk->lmm_stripe_count) {
		rc = -EOVERFLOW;
		goto out_free;
	}
	/*
	 * Have a difference between lov_mds_md & lov_user_md.
	 * So we have to re-order the data before copy to user.
	 */
	lum.lmm_stripe_count = lmmk->lmm_stripe_count;
	lum.lmm_layout_gen = lmmk->lmm_layout_gen;
	((struct lov_user_md *)lmmk)->lmm_layout_gen = lum.lmm_layout_gen;
	((struct lov_user_md *)lmmk)->lmm_stripe_count = lum.lmm_stripe_count;
	if (copy_to_user(lump, lmmk, lmm_size))
		rc = -EFAULT;
	else
		rc = 0;

out_free:
	kvfree(lmmk);
out:
	return rc;
}