path: root/drivers/md/dm-verity-target.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2012 Red Hat, Inc.
 *
 * Author: Mikulas Patocka <mpatocka@redhat.com>
 *
 * Based on Chromium dm-verity driver (C) 2011 The Chromium OS Authors
 *
 * In the file "/sys/module/dm_verity/parameters/prefetch_cluster" you can set
 * default prefetch value. Data are read in "prefetch_cluster" chunks from the
 * hash device. Setting this greatly improves performance when data and hash
 * are on the same disk on different partitions on devices with poor random
 * access behavior.
 */

#include "dm-verity.h"
#include "dm-verity-fec.h"
#include "dm-verity-verify-sig.h"
#include "dm-audit.h"
#include <linux/module.h>
#include <linux/reboot.h>
#include <linux/scatterlist.h>
#include <linux/string.h>
#include <linux/jump_label.h>

#define DM_MSG_PREFIX			"verity"

#define DM_VERITY_ENV_LENGTH		42
#define DM_VERITY_ENV_VAR_NAME		"DM_VERITY_ERR_BLOCK_NR"

#define DM_VERITY_DEFAULT_PREFETCH_SIZE	262144

#define DM_VERITY_MAX_CORRUPTED_ERRS	100

#define DM_VERITY_OPT_LOGGING		"ignore_corruption"
#define DM_VERITY_OPT_RESTART		"restart_on_corruption"
#define DM_VERITY_OPT_PANIC		"panic_on_corruption"
#define DM_VERITY_OPT_IGN_ZEROES	"ignore_zero_blocks"
#define DM_VERITY_OPT_AT_MOST_ONCE	"check_at_most_once"
#define DM_VERITY_OPT_TASKLET_VERIFY	"try_verify_in_tasklet"

#define DM_VERITY_OPTS_MAX		(4 + DM_VERITY_OPTS_FEC + \
					 DM_VERITY_ROOT_HASH_VERIFICATION_OPTS)

static unsigned int dm_verity_prefetch_cluster =