path: root/drivers/md/persistent-data/dm-space-map-common.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2011 Red Hat, Inc.
 *
 * This file is released under the GPL.
 */

#include "dm-space-map-common.h"
#include "dm-transaction-manager.h"
#include "dm-btree-internal.h"
#include "dm-persistent-data-internal.h"

#include <linux/bitops.h>
#include <linux/device-mapper.h>

#define DM_MSG_PREFIX "space map common"

/*----------------------------------------------------------------*/

/*
 * Index validator.
 */
#define INDEX_CSUM_XOR 160478

static void index_prepare_for_write(const struct dm_block_validator *v,
				    struct dm_block *b,
				    size_t block_size)
{
	struct disk_metadata_index *mi_le = dm_block_data(b);

	mi_le->blocknr = cpu_to_le64(dm_block_location(b));
	mi_le->csum = cpu_to_le32(dm_bm_checksum(&mi_le->padding,
						 block_size - sizeof(__le32),
						 INDEX_CSUM_XOR));
}

static int index_check(const struct dm_block_validator *v,
		       struct dm_block *b,
		       size_t block_size)
{
	struct disk_metadata_index *mi_le = dm_block_data(b);
	__le32 csum_disk;

	if (dm_block_location(b) != le64_to_cpu(mi_le->blocknr)) {
		DMERR_LIMIT("%s failed: blocknr %llu != wanted %llu", __func__,
			    le64_to_cpu(mi_le->blocknr), dm_block_location(b));
		return -ENOTBLK;
	}

	csum_disk = cpu_to_le32(dm_bm_checksum(&mi_le->padding,
					       block_size - sizeof(__le32),
					       INDEX_CSUM_XOR));
	if (csum_disk != mi_le->csum) {
		DMERR_LIMIT("i%s failed: csum %u != wanted %u", __func__,
			    le32_to_cpu(csum_disk), le32_to_cpu(mi_le->csum));
		return -EILSEQ;
	}

	return 0;
}

static const struct dm_block_validator index_validator = {
	.name = "index",
	.prepare_for_write = index_prepare_for_write,
	.check = index_check
};

/*----------------------------------------------------------------*/

/*
 * Bitmap validator
 */
#define BITMAP_CSUM_XOR 240779

static void dm_bitmap_prepare_for_write(const struct dm_block_validator *v,
					struct dm_block *b,
					size_t block_size)
{
	struct disk_bitmap_header *disk_header = dm_block_data(b);

	disk_header->blocknr = cpu_to_le64(dm_block_location(b));
	disk_header->csum = cpu_to_le32(dm_bm_checksum(&disk_header->not_used,
						       block_size - sizeof(__le32),
						       BITMAP_CSUM_XOR));
}

static int dm_bitmap_check(const struct dm_block_validator *v,
			   struct dm_block *b,
			   size_t block_size)
{
	struct disk_bitmap_header *disk_header = dm_block_data(b);
	__le32 csum_disk;

	if (dm_block_location(b) != le64_to_cpu(disk_header->blocknr)) {
		DMERR_LIMIT("bitmap check failed: blocknr %llu != wanted %llu",
			    le64_to_cpu(disk_header->blocknr), dm_block_location(b));
		return -ENOTBLK;
	}

	csum_disk = cpu_to_le32(dm_bm_checksum(&disk_header->not_used,
					       block_size - sizeof(__le32),
					       BITMAP_CSUM_XOR));
	if (csum_disk != disk_header->csum) {
		DMERR_LIMIT("bitmap check failed: csum %u != wanted %u",
			    le32_to_cpu(csum_disk), le32_to_cpu(disk_header->csum));
		return -EILSEQ;
	}

	return 0;
}

static const struct dm_block_validator dm_sm_bitmap_validator = {
	.name = "sm_bitmap",