path: root/drivers/md/dm-raid.c

/*
 * Copyright (C) 2010-2011 Neil Brown
 * Copyright (C) 2010-2011 Red Hat, Inc. All rights reserved.
 *
 * This file is released under the GPL.
 */

#include <linux/slab.h>
#include <linux/module.h>

#include "md.h"
#include "raid1.h"
#include "raid5.h"
#include "raid10.h"
#include "bitmap.h"

#include <linux/device-mapper.h>

#define DM_MSG_PREFIX "raid"

/*
 * The following flags are used by dm-raid.c to set up the array state.
 * They must be cleared before md_run is called.
 */
#define FirstUse 10             /* rdev flag */

struct raid_dev {
	/*
	 * Two DM devices, one to hold metadata and one to hold the
	 * actual data/parity.  The reason for this is to not confuse
	 * ti->len and give more flexibility in altering size and
	 * characteristics.
	 *
	 * While it is possible for this device to be associated
	 * with a different physical device than the data_dev, it
	 * is intended for it to be the same.
	 *    |--------- Physical Device ---------|
	 *    |- meta_dev -|------ data_dev ------|
	 */
	struct dm_dev *meta_dev;
	struct dm_dev *data_dev;
	struct md_rdev rdev;
};

/*
 * Flags for rs->print_flags field.
 */
#define DMPF_SYNC              0x1
#define DMPF_NOSYNC            0x2
#define DMPF_REBUILD           0x4
#define DMPF_DAEMON_SLEEP      0x8
#define DMPF_MIN_RECOVERY_RATE 0x10
#define DMPF_MAX_RECOVERY_RATE 0x20
#define DMPF_MAX_WRITE_BEHIND  0x40
#define DMPF_STRIPE_CACHE      0x80
#define DMPF_REGION_SIZE       0x100
#define DMPF_RAID10_COPIES     0x200
#define DMPF_RAID10_FORMAT     0x400

struct raid_set {
	struct dm_target *ti;

	uint32_t bitmap_loaded;
	uint32_t print_flags;

	struct mddev md;
	struct raid_type *raid_type;
	struct dm_target_callbacks callbacks;

	struct raid_dev dev[0];
};

/* Supported raid types and properties. */
static struct raid_type {
	const char *name;		/* RAID algorithm. */
	const char *descr;		/* Descriptor text for logging. */
	const unsigned parity_devs;	/* # of parity devices. */
	const unsigned