linux-imx

/*

 * Copyright (C) 2010-2011 Neil Brown

 * Copyright (C) 2010-2018 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 "md-bitmap.h"

​

#include <linux/device-mapper.h>

​

#define DM_MSG_PREFIX "raid"

#define MAX_RAID_DEVICES    253 /* md-raid kernel limit */

​

/*

 * Minimum sectors of free reshape space per raid device

 */

#define MIN_FREE_RESHAPE_SPACE to_sector(4*4096)

​

/*

 * Minimum journal space 4 MiB in sectors.

 */

#define MIN_RAID456_JOURNAL_SPACE (4*2048)

​

static bool devices_handle_discard_safely = false;

​

/*

 * 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;

};

​

/*

 * Bits for establishing rs->ctr_flags

 *

 * 1 = no flag value

 * 2 = flag with value

 */

#define __CTR_FLAG_SYNC         0  /* 1 */ /* Not with raid0! */

#define __CTR_FLAG_NOSYNC       1  /* 1 */ /* Not with raid0! */

#define __CTR_FLAG_REBUILD      2  /* 2 */ /* Not with raid0! */

#define __CTR_FLAG_DAEMON_SLEEP     3  /* 2 */ /* Not with raid0! */

#define __CTR_FLAG_MIN_RECOVERY_RATE    4  /* 2 */ /* Not with raid0! */

#define __CTR_FLAG_MAX_RECOVERY_RATE    5  /* 2 */ /* Not with raid0! */

#define __CTR_FLAG_MAX_WRITE_BEHIND 6  /* 2 */ /* Only with raid1! */

#define __CTR_FLAG_WRITE_MOSTLY     7  /* 2 */ /* Only with raid1! */

#define __CTR_FLAG_STRIPE_CACHE     8  /* 2 */ /* Only with raid4/5/6! */

#define __CTR_FLAG_REGION_SIZE      9  /* 2 */ /* Not with raid0! */

#define __CTR_FLAG_RAID10_COPIES    10 /* 2 */ /* Only with raid10 */

#define __CTR_FLAG_RAID10_FORMAT    11 /* 2 */ /* Only with raid10 */

/* New for v1.9.0 */

#define __CTR_FLAG_DELTA_DISKS      12 /* 2 */ /* Only with reshapable raid1/4/5/6/10! */

#define __CTR_FLAG_DATA_OFFSET      13 /* 2 */ /* Only with reshapable raid4/5/6/10! */

#define __CTR_FLAG_RAID10_USE_NEAR_SETS 14 /* 2 */ /* Only with raid10! */

​

/* New for v1.10.0 */

#define __CTR_FLAG_JOURNAL_DEV      15 /* 2 */ /* Only with raid4/5/6 (journal device)! */

​

/* New for v1.11.1 */

#define __CTR_FLAG_JOURNAL_MODE     16 /* 2 */ /* Only with raid4/5/6 (journal mode)! */

​

/*

 * Flags for rs->ctr_flags field.

 */

#define CTR_FLAG_SYNC           (1 << __CTR_FLAG_SYNC)

#define CTR_FLAG_NOSYNC         (1 << __CTR_FLAG_NOSYNC)

#define CTR_FLAG_REBUILD        (1 << __CTR_FLAG_REBUILD)