imsm: Prepare checkpoint update for general migration

[thirdparty/mdadm.git] / super-intel.c

/*
 * mdadm - Intel(R) Matrix Storage Manager Support
 *
 * Copyright (C) 2002-2008 Intel Corporation
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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 for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 */

#define HAVE_STDINT_H 1
#include "mdadm.h"
#include "mdmon.h"
#include "sha1.h"
#include "platform-intel.h"
#include <values.h>
#include <scsi/sg.h>
#include <ctype.h>
#include <dirent.h>

/* MPB == Metadata Parameter Block */
#define MPB_SIGNATURE "Intel Raid ISM Cfg Sig. "
#define MPB_SIG_LEN (strlen(MPB_SIGNATURE))
#define MPB_VERSION_RAID0 "1.0.00"
#define MPB_VERSION_RAID1 "1.1.00"
#define MPB_VERSION_MANY_VOLUMES_PER_ARRAY "1.2.00"
#define MPB_VERSION_3OR4_DISK_ARRAY "1.2.01"
#define MPB_VERSION_RAID5 "1.2.02"
#define MPB_VERSION_5OR6_DISK_ARRAY "1.2.04"
#define MPB_VERSION_CNG "1.2.06"
#define MPB_VERSION_ATTRIBS "1.3.00"
#define MAX_SIGNATURE_LENGTH  32
#define MAX_RAID_SERIAL_LEN   16

#define MPB_ATTRIB_CHECKSUM_VERIFY __cpu_to_le32(0x80000000)
#define MPB_ATTRIB_PM      __cpu_to_le32(0x40000000)
#define MPB_ATTRIB_2TB     __cpu_to_le32(0x20000000)
#define MPB_ATTRIB_RAID0   __cpu_to_le32(0x00000001)
#define MPB_ATTRIB_RAID1   __cpu_to_le32(0x00000002)
#define MPB_ATTRIB_RAID10  __cpu_to_le32(0x00000004)
#define MPB_ATTRIB_RAID1E  __cpu_to_le32(0x00000008)
#define MPB_ATTRIB_RAID5   __cpu_to_le32(0x00000010)
#define MPB_ATTRIB_RAIDCNG __cpu_to_le32(0x00000020)

#define MPB_SECTOR_CNT 2210
#define IMSM_RESERVED_SECTORS 4096
#define SECT_PER_MB_SHIFT 11

/* Disk configuration info. */
#define IMSM_MAX_DEVICES 255
struct imsm_disk {
        __u8 serial[MAX_RAID_SERIAL_LEN];/* 0xD8 - 0xE7 ascii serial number */
        __u32 total_blocks;              /* 0xE8 - 0xEB total blocks */
        __u32 scsi_id;                   /* 0xEC - 0xEF scsi ID */
#define SPARE_DISK      __cpu_to_le32(0x01)  /* Spare */
#define CONFIGURED_DISK __cpu_to_le32(0x02)  /* Member of some RaidDev */
#define FAILED_DISK     __cpu_to_le32(0x04)  /* Permanent failure */
        __u32 status;                    /* 0xF0 - 0xF3 */
        __u32 owner_cfg_num; /* which config 0,1,2... owns this disk */ 
#define IMSM_DISK_FILLERS       4
        __u32 filler[IMSM_DISK_FILLERS]; /* 0xF4 - 0x107 MPB_DISK_FILLERS for future expansion */
};

/* RAID map configuration infos. */
struct imsm_map {
        __u32 pba_of_lba0;      /* start address of partition */
        __u32 blocks_per_member;/* blocks per member */
        __u32 num_data_stripes; /* number of data stripes */
        __u16 blocks_per_strip;
        __u8  map_state;        /* Normal, Uninitialized, Degraded, Failed */
#define IMSM_T_STATE_NORMAL 0
#define IMSM_T_STATE_UNINITIALIZED 1
#define IMSM_T_STATE_DEGRADED 2
#define IMSM_T_STATE_FAILED 3
        __u8  raid_level;
#define IMSM_T_RAID0 0
#define IMSM_T_RAID1 1
#define IMSM_T_RAID5 5          /* since metadata version 1.2.02 ? */
        __u8  num_members;      /* number of member disks */
        __u8  num_domains;      /* number of parity domains */
        __u8  failed_disk_num;  /* valid only when state is degraded */
        __u8  ddf;
        __u32 filler[7];        /* expansion area */
#define IMSM_ORD_REBUILD (1 << 24)
        __u32 disk_ord_tbl[1];  /* disk_ord_tbl[num_members],
                                 * top byte contains some flags
                                 */
} __attribute__ ((packed));

struct imsm_vol {
        __u32 curr_migr_unit;
        __u32 checkpoint_id;    /* id to access curr_migr_unit */
        __u8  migr_state;       /* Normal or Migrating */
#define MIGR_INIT 0
#define MIGR_REBUILD 1
#define MIGR_VERIFY 2 /* analagous to echo check > sync_action */
#define MIGR_GEN_MIGR 3
#define MIGR_STATE_CHANGE 4
#define MIGR_REPAIR 5
        __u8  migr_type;        /* Initializing, Rebuilding, ... */
        __u8  dirty;
        __u8  fs_state;         /* fast-sync state for CnG (0xff == disabled) */
        __u16 verify_errors;    /* number of mismatches */
        __u16 bad_blocks;       /* number of bad blocks during verify */
        __u32 filler[4];
        struct imsm_map map[1];
        /* here comes another one if migr_state */
} __attribute__ ((packed));

struct imsm_dev {
        __u8  volume[MAX_RAID_SERIAL_LEN];
        __u32 size_low;
        __u32 size_high;
#define DEV_BOOTABLE            __cpu_to_le32(0x01)
#define DEV_BOOT_DEVICE         __cpu_to_le32(0x02)
#define DEV_READ_COALESCING     __cpu_to_le32(0x04)
#define DEV_WRITE_COALESCING    __cpu_to_le32(0x08)
#define DEV_LAST_SHUTDOWN_DIRTY __cpu_to_le32(0x10)
#define DEV_HIDDEN_AT_BOOT      __cpu_to_le32(0x20)
#define DEV_CURRENTLY_HIDDEN    __cpu_to_le32(0x40)
#define DEV_VERIFY_AND_FIX      __cpu_to_le32(0x80)
#define DEV_MAP_STATE_UNINIT    __cpu_to_le32(0x100)
#define DEV_NO_AUTO_RECOVERY    __cpu_to_le32(0x200)
#define DEV_CLONE_N_GO          __cpu_to_le32(0x400)
#define DEV_CLONE_MAN_SYNC      __cpu_to_le32(0x800)
#define DEV_CNG_MASTER_DISK_NUM __cpu_to_le32(0x1000)
        __u32 status;   /* Persistent RaidDev status */
        __u32 reserved_blocks; /* Reserved blocks at beginning of volume */
        __u8  migr_priority;
        __u8  num_sub_vols;
        __u8  tid;
        __u8  cng_master_disk;
        __u16 cache_policy;
        __u8  cng_state;
        __u8  cng_sub_state;
#define IMSM_DEV_FILLERS 10
        __u32 filler[IMSM_DEV_FILLERS];
        struct imsm_vol vol;
} __attribute__ ((packed));

struct imsm_super {
        __u8 sig[MAX_SIGNATURE_LENGTH]; /* 0x00 - 0x1F */
        __u32 check_sum;                /* 0x20 - 0x23 MPB Checksum */
        __u32 mpb_size;                 /* 0x24 - 0x27 Size of MPB */
        __u32 family_num;               /* 0x28 - 0x2B Checksum from first time this config was written */
        __u32 generation_num;           /* 0x2C - 0x2F Incremented each time this array's MPB is written */
        __u32 error_log_size;           /* 0x30 - 0x33 in bytes */
        __u32 attributes;               /* 0x34 - 0x37 */
        __u8 num_disks;                 /* 0x38 Number of configured disks */
        __u8 num_raid_devs;             /* 0x39 Number of configured volumes */
        __u8 error_log_pos;             /* 0x3A  */
        __u8 fill[1];                   /* 0x3B */
        __u32 cache_size;               /* 0x3c - 0x40 in mb */
        __u32 orig_family_num;          /* 0x40 - 0x43 original family num */
        __u32 pwr_cycle_count;          /* 0x44 - 0x47 simulated power cycle count for array */
        __u32 bbm_log_size;             /* 0x48 - 0x4B - size of bad Block Mgmt Log in bytes */
#define IMSM_FILLERS 35
        __u32 filler[IMSM_FILLERS];     /* 0x4C - 0xD7 RAID_MPB_FILLERS */
        struct imsm_disk disk[1];       /* 0xD8 diskTbl[numDisks] */
        /* here comes imsm_dev[num_raid_devs] */
        /* here comes BBM logs */
} __attribute__ ((packed));

#define BBM_LOG_MAX_ENTRIES 254

struct bbm_log_entry {
        __u64 defective_block_start;
#define UNREADABLE 0xFFFFFFFF
        __u32 spare_block_offset;
        __u16 remapped_marked_count;
        __u16 disk_ordinal;
} __attribute__ ((__packed__));

struct bbm_log {
        __u32 signature; /* 0xABADB10C */
        __u32 entry_count;
        __u32 reserved_spare_block_count; /* 0 */
        __u32 reserved; /* 0xFFFF */
        __u64 first_spare_lba;
        struct bbm_log_entry mapped_block_entries[BBM_LOG_MAX_ENTRIES];
} __attribute__ ((__packed__));


#ifndef MDASSEMBLE
static char *map_state_str[] = { "normal", "uninitialized", "degraded", "failed" };
#endif

#define RAID_DISK_RESERVED_BLOCKS_IMSM_HI 2209

#define GEN_MIGR_AREA_SIZE 2048 /* General Migration Copy Area size in blocks */

#define UNIT_SRC_NORMAL     0   /* Source data for curr_migr_unit must
                                 *  be recovered using srcMap */
#define UNIT_SRC_IN_CP_AREA 1   /* Source data for curr_migr_unit has
                                 *  already been migrated and must
                                 *  be recovered from checkpoint area */
struct migr_record {
        __u32 rec_status;           /* Status used to determine how to restart
                                     * migration in case it aborts
                                     * in some fashion */
        __u32 curr_migr_unit;       /* 0..numMigrUnits-1 */
        __u32 family_num;           /* Family number of MPB
                                     * containing the RaidDev
                                     * that is migrating */
        __u32 ascending_migr;       /* True if migrating in increasing
                                     * order of lbas */
        __u32 blocks_per_unit;      /* Num disk blocks per unit of operation */
        __u32 dest_depth_per_unit;  /* Num member blocks each destMap
                                     * member disk
                                     * advances per unit-of-operation */
        __u32 ckpt_area_pba;        /* Pba of first block of ckpt copy area */
        __u32 dest_1st_member_lba;  /* First member lba on first
                                     * stripe of destination */
        __u32 num_migr_units;       /* Total num migration units-of-op */
        __u32 post_migr_vol_cap;    /* Size of volume after
                                     * migration completes */
        __u32 post_migr_vol_cap_hi; /* Expansion space for LBA64 */
        __u32 ckpt_read_disk_num;   /* Which member disk in destSubMap[0] the
                                     * migration ckpt record was read from
                                     * (for recovered migrations) */
} __attribute__ ((__packed__));

static __u8 migr_type(struct imsm_dev *dev)
{
        if (dev->vol.migr_type == MIGR_VERIFY &&
            dev->status & DEV_VERIFY_AND_FIX)
                return MIGR_REPAIR;
        else
                return dev->vol.migr_type;
}

static void set_migr_type(struct imsm_dev *dev, __u8 migr_type)
{
        /* for compatibility with older oroms convert MIGR_REPAIR, into
         * MIGR_VERIFY w/ DEV_VERIFY_AND_FIX status
         */
        if (migr_type == MIGR_REPAIR) {
                dev->vol.migr_type = MIGR_VERIFY;
                dev->status |= DEV_VERIFY_AND_FIX;
        } else {
                dev->vol.migr_type = migr_type;
                dev->status &= ~DEV_VERIFY_AND_FIX;
        }
}

static unsigned int sector_count(__u32 bytes)
{
        return ((bytes + (512-1)) & (~(512-1))) / 512;
}

static unsigned int mpb_sectors(struct imsm_super *mpb)
{
        return sector_count(__le32_to_cpu(mpb->mpb_size));
}

struct intel_dev {
        struct imsm_dev *dev;
        struct intel_dev *next;
        unsigned index;
};

struct intel_hba {
        enum sys_dev_type type;
        char *path;
        char *pci_id;
        struct intel_hba *next;
};

enum action {
        DISK_REMOVE = 1,
        DISK_ADD
};
/* internal representation of IMSM metadata */
struct intel_super {
        union {
                void *buf; /* O_DIRECT buffer for reading/writing metadata */
                struct imsm_super *anchor; /* immovable parameters */
        };
        union {
                void *migr_rec_buf; /* buffer for I/O operations */
                struct migr_record *migr_rec; /* migration record */
        };
        size_t len; /* size of the 'buf' allocation */
        void *next_buf; /* for realloc'ing buf from the manager */
        size_t next_len;
        int updates_pending; /* count of pending updates for mdmon */
        int current_vol; /* index of raid device undergoing creation */
        __u32 create_offset; /* common start for 'current_vol' */
        __u32 random; /* random data for seeding new family numbers */
        struct intel_dev *devlist;
        struct dl {
                struct dl *next;
                int index;
                __u8 serial[MAX_RAID_SERIAL_LEN];
                int major, minor;
                char *devname;
                struct imsm_disk disk;
                int fd;
                int extent_cnt;
                struct extent *e; /* for determining freespace @ create */
                int raiddisk; /* slot to fill in autolayout */
                enum action action;
        } *disks;
        struct dl *disk_mgmt_list; /* list of disks to add/remove while mdmon
                                      active */
        struct dl *missing; /* disks removed while we weren't looking */
        struct bbm_log *bbm_log;
        struct intel_hba *hba; /* device path of the raid controller for this metadata */
        const struct imsm_orom *orom; /* platform firmware support */
        struct intel_super *next; /* (temp) list for disambiguating family_num */
};

struct intel_disk {
        struct imsm_disk disk;
        #define IMSM_UNKNOWN_OWNER (-1)
        int owner;
        struct intel_disk *next;
};

struct extent {
        unsigned long long start, size;
};

/* definitions of reshape process types */
enum imsm_reshape_type {
        CH_TAKEOVER,
        CH_MIGRATION,
};

/* definition of messages passed to imsm_process_update */
enum imsm_update_type {
        update_activate_spare,
        update_create_array,
        update_kill_array,
        update_rename_array,
        update_add_remove_disk,
        update_reshape_container_disks,
        update_reshape_migration,
        update_takeover,
        update_general_migration_checkpoint,
};

struct imsm_update_activate_spare {
        enum imsm_update_type type;
        struct dl *dl;
        int slot;
        int array;
        struct imsm_update_activate_spare *next;
};

struct geo_params {
        int dev_id;
        char *dev_name;
        long long size;
        int level;
        int layout;
        int chunksize;
        int raid_disks;
};

enum takeover_direction {
        R10_TO_R0,
        R0_TO_R10
};
struct imsm_update_takeover {
        enum imsm_update_type type;
        int subarray;
        enum takeover_direction direction;
};

struct imsm_update_reshape {
        enum imsm_update_type type;
        int old_raid_disks;
        int new_raid_disks;

        int new_disks[1]; /* new_raid_disks - old_raid_disks makedev number */
};

struct imsm_update_reshape_migration {
        enum imsm_update_type type;
        int old_raid_disks;
        int new_raid_disks;
        /* fields for array migration changes
         */
        int subdev;
        int new_level;
        int new_layout;
        int new_chunksize;

        int new_disks[1]; /* new_raid_disks - old_raid_disks makedev number */
};

struct imsm_update_general_migration_checkpoint {
        enum imsm_update_type type;
        __u32 curr_migr_unit;
};

struct disk_info {
        __u8 serial[MAX_RAID_SERIAL_LEN];
};

struct imsm_update_create_array {
        enum imsm_update_type type;
        int dev_idx;
        struct imsm_dev dev;
};

struct imsm_update_kill_array {
        enum imsm_update_type type;
        int dev_idx;
};

struct imsm_update_rename_array {
        enum imsm_update_type type;
        __u8 name[MAX_RAID_SERIAL_LEN];
        int dev_idx;
};

struct imsm_update_add_remove_disk {
        enum imsm_update_type type;
};


static const char *_sys_dev_type[] = {
        [SYS_DEV_UNKNOWN] = "Unknown",
        [SYS_DEV_SAS] = "SAS",
        [SYS_DEV_SATA] = "SATA"
};

const char *get_sys_dev_type(enum sys_dev_type type)
{
        if (type >= SYS_DEV_MAX)
                type = SYS_DEV_UNKNOWN;

        return _sys_dev_type[type];
}

static struct intel_hba * alloc_intel_hba(struct sys_dev *device)
{
        struct intel_hba *result = malloc(sizeof(*result));
        if (result) {
                result->type = device->type;
                result->path = strdup(device->path);
                result->next = NULL;
                if (result->path && (result->pci_id = strrchr(result->path, '/')) != NULL)
                        result->pci_id++;
        }
        return result;
}

static struct intel_hba * find_intel_hba(struct intel_hba *hba, struct sys_dev *device)
{
        struct intel_hba *result=NULL;
        for (result = hba; result; result = result->next) {
                if (result->type == device->type && strcmp(result->path, device->path) == 0)
                        break;
        }
        return result;
}

static int attach_hba_to_super(struct intel_super *super, struct sys_dev *device)
{
        struct intel_hba *hba;

        /* check if disk attached to Intel HBA */
        hba = find_intel_hba(super->hba, device);
        if (hba != NULL)
                return 1;
        /* Check if HBA is already attached to super */
        if (super->hba == NULL) {
                super->hba = alloc_intel_hba(device);
                return 1;
        }

        hba = super->hba;
        /* Intel metadata allows for all disks attached to the same type HBA.
         * Do not sypport odf HBA types mixing
         */
        if (device->type != hba->type)
                return 2;

        while (hba->next)
                hba = hba->next;

        hba->next = alloc_intel_hba(device);
        return 1;
}

static struct sys_dev* find_disk_attached_hba(int fd, const char *devname)
{
        struct sys_dev *list, *elem, *prev;
        char *disk_path;

        if ((list = find_intel_devices()) == NULL)
                return 0;

        if (fd < 0)
                disk_path  = (char *) devname;
        else
                disk_path = diskfd_to_devpath(fd);

        if (!disk_path) {
                free_sys_dev(&list);
                return 0;
        }

        for (prev = NULL, elem = list; elem; prev = elem, elem = elem->next) {
                if (path_attached_to_hba(disk_path, elem->path)) {
                        if (prev == NULL)
                                list = list->next;
                        else
                                prev->next = elem->next;
                        elem->next = NULL;
                        if (disk_path != devname)
                                free(disk_path);
                        free_sys_dev(&list);
                        return elem;
                }
        }
        if (disk_path != devname)
                free(disk_path);
        free_sys_dev(&list);

        return NULL;
}


static int find_intel_hba_capability(int fd, struct intel_super *super,
                                     char *devname);

static struct supertype *match_metadata_desc_imsm(char *arg)
{
        struct supertype *st;

        if (strcmp(arg, "imsm") != 0 &&
            strcmp(arg, "default") != 0
                )
                return NULL;

        st = malloc(sizeof(*st));
        if (!st)
                return NULL;
        memset(st, 0, sizeof(*st));
        st->container_dev = NoMdDev;
        st->ss = &super_imsm;
        st->max_devs = IMSM_MAX_DEVICES;
        st->minor_version = 0;
        st->sb = NULL;
        return st;
}

#ifndef MDASSEMBLE
static __u8 *get_imsm_version(struct imsm_super *mpb)
{
        return &mpb->sig[MPB_SIG_LEN];
}
#endif 

/* retrieve a disk directly from the anchor when the anchor is known to be
 * up-to-date, currently only at load time
 */
static struct imsm_disk *__get_imsm_disk(struct imsm_super *mpb, __u8 index)
{
        if (index >= mpb->num_disks)
                return NULL;
        return &mpb->disk[index];
}

/* retrieve the disk description based on a index of the disk
 * in the sub-array
 */
static struct dl *get_imsm_dl_disk(struct intel_super *super, __u8 index)
{
        struct dl *d;

        for (d = super->disks; d; d = d->next)
                if (d->index == index)
                        return d;

        return NULL;
}
/* retrieve a disk from the parsed metadata */
static struct imsm_disk *get_imsm_disk(struct intel_super *super, __u8 index)
{
        struct dl *dl;

        dl = get_imsm_dl_disk(super, index);
        if (dl)
                return &dl->disk;

        return NULL;
}

/* generate a checksum directly from the anchor when the anchor is known to be
 * up-to-date, currently only at load or write_super after coalescing
 */
static __u32 __gen_imsm_checksum(struct imsm_super *mpb)
{
        __u32 end = mpb->mpb_size / sizeof(end);
        __u32 *p = (__u32 *) mpb;
        __u32 sum = 0;

        while (end--) {
                sum += __le32_to_cpu(*p);
                p++;
        }

        return sum - __le32_to_cpu(mpb->check_sum);
}

static size_t sizeof_imsm_map(struct imsm_map *map)
{
        return sizeof(struct imsm_map) + sizeof(__u32) * (map->num_members - 1);
}

struct imsm_map *get_imsm_map(struct imsm_dev *dev, int second_map)
{
        /* A device can have 2 maps if it is in the middle of a migration.
         * If second_map is:
         *    0   - we return the first map
         *    1   - we return the second map if it exists, else NULL
         *   -1   - we return the second map if it exists, else the first
         */
        struct imsm_map *map = &dev->vol.map[0];

        if (second_map == 1 && !dev->vol.migr_state)
                return NULL;
        else if (second_map == 1 ||
                 (second_map < 0 && dev->vol.migr_state)) {
                void *ptr = map;

                return ptr + sizeof_imsm_map(map);
        } else
                return map;

}

/* return the size of the device.
 * migr_state increases the returned size if map[0] were to be duplicated
 */
static size_t sizeof_imsm_dev(struct imsm_dev *dev, int migr_state)
{
        size_t size = sizeof(*dev) - sizeof(struct imsm_map) +
                      sizeof_imsm_map(get_imsm_map(dev, 0));

        /* migrating means an additional map */
        if (dev->vol.migr_state)
                size += sizeof_imsm_map(get_imsm_map(dev, 1));
        else if (migr_state)
                size += sizeof_imsm_map(get_imsm_map(dev, 0));

        return size;
}

#ifndef MDASSEMBLE
/* retrieve disk serial number list from a metadata update */
static struct disk_info *get_disk_info(struct imsm_update_create_array *update)
{
        void *u = update;
        struct disk_info *inf;

        inf = u + sizeof(*update) - sizeof(struct imsm_dev) +
              sizeof_imsm_dev(&update->dev, 0);

        return inf;
}
#endif

static struct imsm_dev *__get_imsm_dev(struct imsm_super *mpb, __u8 index)
{
        int offset;
        int i;
        void *_mpb = mpb;

        if (index >= mpb->num_raid_devs)
                return NULL;

        /* devices start after all disks */
        offset = ((void *) &mpb->disk[mpb->num_disks]) - _mpb;

        for (i = 0; i <= index; i++)
                if (i == index)
                        return _mpb + offset;
                else
                        offset += sizeof_imsm_dev(_mpb + offset, 0);

        return NULL;
}

static struct imsm_dev *get_imsm_dev(struct intel_super *super, __u8 index)
{
        struct intel_dev *dv;

        if (index >= super->anchor->num_raid_devs)
                return NULL;
        for (dv = super->devlist; dv; dv = dv->next)
                if (dv->index == index)
                        return dv->dev;
        return NULL;
}

/*
 * for second_map:
 *  == 0 get first map
 *  == 1 get second map
 *  == -1 than get map according to the current migr_state
 */
static __u32 get_imsm_ord_tbl_ent(struct imsm_dev *dev,
                                  int slot,
                                  int second_map)
{
        struct imsm_map *map;

        map = get_imsm_map(dev, second_map);

        /* top byte identifies disk under rebuild */
        return __le32_to_cpu(map->disk_ord_tbl[slot]);
}

#define ord_to_idx(ord) (((ord) << 8) >> 8)
static __u32 get_imsm_disk_idx(struct imsm_dev *dev, int slot, int second_map)
{
        __u32 ord = get_imsm_ord_tbl_ent(dev, slot, second_map);

        return ord_to_idx(ord);
}

static void set_imsm_ord_tbl_ent(struct imsm_map *map, int slot, __u32 ord)
{
        map->disk_ord_tbl[slot] = __cpu_to_le32(ord);
}

static int get_imsm_disk_slot(struct imsm_map *map, unsigned idx)
{
        int slot;
        __u32 ord;

        for (slot = 0; slot < map->num_members; slot++) {
                ord = __le32_to_cpu(map->disk_ord_tbl[slot]);
                if (ord_to_idx(ord) == idx)
                        return slot;
        }

        return -1;
}

static int get_imsm_raid_level(struct imsm_map *map)
{
        if (map->raid_level == 1) {
                if (map->num_members == 2)
                        return 1;
                else
                        return 10;
        }

        return map->raid_level;
}

static int cmp_extent(const void *av, const void *bv)
{
        const struct extent *a = av;
        const struct extent *b = bv;
        if (a->start < b->start)
                return -1;
        if (a->start > b->start)
                return 1;
        return 0;
}

static int count_memberships(struct dl *dl, struct intel_super *super)
{
        int memberships = 0;
        int i;

        for (i = 0; i < super->anchor->num_raid_devs; i++) {
                struct imsm_dev *dev = get_imsm_dev(super, i);
                struct imsm_map *map = get_imsm_map(dev, 0);

                if (get_imsm_disk_slot(map, dl->index) >= 0)
                        memberships++;
        }

        return memberships;
}

static struct extent *get_extents(struct intel_super *super, struct dl *dl)
{
        /* find a list of used extents on the given physical device */
        struct extent *rv, *e;
        int i;
        int memberships = count_memberships(dl, super);
        __u32 reservation = MPB_SECTOR_CNT + IMSM_RESERVED_SECTORS;

        rv = malloc(sizeof(struct extent) * (memberships + 1));
        if (!rv)
                return NULL;
        e = rv;

        for (i = 0; i < super->anchor->num_raid_devs; i++) {
                struct imsm_dev *dev = get_imsm_dev(super, i);
                struct imsm_map *map = get_imsm_map(dev, 0);

                if (get_imsm_disk_slot(map, dl->index) >= 0) {
                        e->start = __le32_to_cpu(map->pba_of_lba0);
                        e->size = __le32_to_cpu(map->blocks_per_member);
                        e++;
                }
        }
        qsort(rv, memberships, sizeof(*rv), cmp_extent);

        /* determine the start of the metadata 
         * when no raid devices are defined use the default
         * ...otherwise allow the metadata to truncate the value
         * as is the case with older versions of imsm
         */
        if (memberships) {
                struct extent *last = &rv[memberships - 1];
                __u32 remainder;

                remainder = __le32_to_cpu(dl->disk.total_blocks) - 
                            (last->start + last->size);
                /* round down to 1k block to satisfy precision of the kernel
                 * 'size' interface
                 */
                remainder &= ~1UL;
                /* make sure remainder is still sane */
                if (remainder < (unsigned)ROUND_UP(super->len, 512) >> 9)
                        remainder = ROUND_UP(super->len, 512) >> 9;
                if (reservation > remainder)
                        reservation = remainder;
        }
        e->start = __le32_to_cpu(dl->disk.total_blocks) - reservation;
        e->size = 0;
        return rv;
}

/* try to determine how much space is reserved for metadata from
 * the last get_extents() entry, otherwise fallback to the
 * default
 */
static __u32 imsm_reserved_sectors(struct intel_super *super, struct dl *dl)
{
        struct extent *e;
        int i;
        __u32 rv;

        /* for spares just return a minimal reservation which will grow
         * once the spare is picked up by an array
         */
        if (dl->index == -1)
                return MPB_SECTOR_CNT;

        e = get_extents(super, dl);
        if (!e)
                return MPB_SECTOR_CNT + IMSM_RESERVED_SECTORS;

        /* scroll to last entry */
        for (i = 0; e[i].size; i++)
                continue;

        rv = __le32_to_cpu(dl->disk.total_blocks) - e[i].start;

        free(e);

        return rv;
}

static int is_spare(struct imsm_disk *disk)
{
        return (disk->status & SPARE_DISK) == SPARE_DISK;
}

static int is_configured(struct imsm_disk *disk)
{
        return (disk->status & CONFIGURED_DISK) == CONFIGURED_DISK;
}

static int is_failed(struct imsm_disk *disk)
{
        return (disk->status & FAILED_DISK) == FAILED_DISK;
}

/* Return minimum size of a spare that can be used in this array*/
static unsigned long long min_acceptable_spare_size_imsm(struct supertype *st)
{
        struct intel_super *super = st->sb;
        struct dl *dl;
        struct extent *e;
        int i;
        unsigned long long rv = 0;

        if (!super)
                return rv;
        /* find first active disk in array */
        dl = super->disks;
        while (dl && (is_failed(&dl->disk) || dl->index == -1))
                dl = dl->next;
        if (!dl)
                return rv;
        /* find last lba used by subarrays */
        e = get_extents(super, dl);
        if (!e)
                return rv;
        for (i = 0; e[i].size; i++)
                continue;
        if (i > 0)
                rv = e[i-1].start + e[i-1].size;
        free(e);
        /* add the amount of space needed for metadata */
        rv = rv + MPB_SECTOR_CNT + IMSM_RESERVED_SECTORS;
        return rv * 512;
}

#ifndef MDASSEMBLE
static __u64 blocks_per_migr_unit(struct intel_super *super,
                                  struct imsm_dev *dev);

static void print_imsm_dev(struct intel_super *super,
                           struct imsm_dev *dev,
                           char *uuid,
                           int disk_idx)
{
        __u64 sz;
        int slot, i;
        struct imsm_map *map = get_imsm_map(dev, 0);
        struct imsm_map *map2 = get_imsm_map(dev, 1);
        __u32 ord;

        printf("\n");
        printf("[%.16s]:\n", dev->volume);
        printf("           UUID : %s\n", uuid);
        printf("     RAID Level : %d", get_imsm_raid_level(map));
        if (map2)
                printf(" <-- %d", get_imsm_raid_level(map2));
        printf("\n");
        printf("        Members : %d", map->num_members);
        if (map2)
                printf(" <-- %d", map2->num_members);
        printf("\n");
        printf("          Slots : [");
        for (i = 0; i < map->num_members; i++) {
                ord = get_imsm_ord_tbl_ent(dev, i, 0);
                printf("%s", ord & IMSM_ORD_REBUILD ? "_" : "U");
        }
        printf("]");
        if (map2) {
                printf(" <-- [");
                for (i = 0; i < map2->num_members; i++) {
                        ord = get_imsm_ord_tbl_ent(dev, i, 1);
                        printf("%s", ord & IMSM_ORD_REBUILD ? "_" : "U");
                }
                printf("]");
        }
        printf("\n");
        printf("    Failed disk : ");
        if (map->failed_disk_num == 0xff)
                printf("none");
        else
                printf("%i", map->failed_disk_num);
        printf("\n");
        slot = get_imsm_disk_slot(map, disk_idx);
        if (slot >= 0) {
                ord = get_imsm_ord_tbl_ent(dev, slot, -1);
                printf("      This Slot : %d%s\n", slot,
                       ord & IMSM_ORD_REBUILD ? " (out-of-sync)" : "");
        } else
                printf("      This Slot : ?\n");
        sz = __le32_to_cpu(dev->size_high);
        sz <<= 32;
        sz += __le32_to_cpu(dev->size_low);
        printf("     Array Size : %llu%s\n", (unsigned long long)sz,
               human_size(sz * 512));
        sz = __le32_to_cpu(map->blocks_per_member);
        printf("   Per Dev Size : %llu%s\n", (unsigned long long)sz,
               human_size(sz * 512));
        printf("  Sector Offset : %u\n",
                __le32_to_cpu(map->pba_of_lba0));
        printf("    Num Stripes : %u\n",
                __le32_to_cpu(map->num_data_stripes));
        printf("     Chunk Size : %u KiB",
                __le16_to_cpu(map->blocks_per_strip) / 2);
        if (map2)
                printf(" <-- %u KiB",
                        __le16_to_cpu(map2->blocks_per_strip) / 2);
        printf("\n");
        printf("       Reserved : %d\n", __le32_to_cpu(dev->reserved_blocks));
        printf("  Migrate State : ");
        if (dev->vol.migr_state) {
                if (migr_type(dev) == MIGR_INIT)
                        printf("initialize\n");
                else if (migr_type(dev) == MIGR_REBUILD)
                        printf("rebuild\n");
                else if (migr_type(dev) == MIGR_VERIFY)
                        printf("check\n");
                else if (migr_type(dev) == MIGR_GEN_MIGR)
                        printf("general migration\n");
                else if (migr_type(dev) == MIGR_STATE_CHANGE)
                        printf("state change\n");
                else if (migr_type(dev) == MIGR_REPAIR)
                        printf("repair\n");
                else
                        printf("<unknown:%d>\n", migr_type(dev));
        } else
                printf("idle\n");
        printf("      Map State : %s", map_state_str[map->map_state]);
        if (dev->vol.migr_state) {
                struct imsm_map *map = get_imsm_map(dev, 1);

                printf(" <-- %s", map_state_str[map->map_state]);
                printf("\n     Checkpoint : %u (%llu)",
                       __le32_to_cpu(dev->vol.curr_migr_unit),
                       (unsigned long long)blocks_per_migr_unit(super, dev));
        }
        printf("\n");
        printf("    Dirty State : %s\n", dev->vol.dirty ? "dirty" : "clean");
}

static void print_imsm_disk(struct imsm_super *mpb, int index, __u32 reserved)
{
        struct imsm_disk *disk = __get_imsm_disk(mpb, index);
        char str[MAX_RAID_SERIAL_LEN + 1];
        __u64 sz;

        if (index < 0 || !disk)
                return;

        printf("\n");
        snprintf(str, MAX_RAID_SERIAL_LEN + 1, "%s", disk->serial);
        printf("  Disk%02d Serial : %s\n", index, str);
        printf("          State :%s%s%s\n", is_spare(disk) ? " spare" : "",
                                            is_configured(disk) ? " active" : "",
                                            is_failed(disk) ? " failed" : "");
        printf("             Id : %08x\n", __le32_to_cpu(disk->scsi_id));
        sz = __le32_to_cpu(disk->total_blocks) - reserved;
        printf("    Usable Size : %llu%s\n", (unsigned long long)sz,
               human_size(sz * 512));
}

static int is_gen_migration(struct imsm_dev *dev);

void examine_migr_rec_imsm(struct intel_super *super)
{
        struct migr_record *migr_rec = super->migr_rec;
        struct imsm_super *mpb = super->anchor;
        int i;

        for (i = 0; i < mpb->num_raid_devs; i++) {
                struct imsm_dev *dev = __get_imsm_dev(mpb, i);
                if (is_gen_migration(dev) == 0)
                                continue;

                printf("\nMigration Record Information:");
                if (super->disks->index > 1) {
                        printf(" Empty\n                              ");
                        printf("Examine one of first two disks in array\n");
                        break;
                }
                printf("\n                     Status : ");
                if (__le32_to_cpu(migr_rec->rec_status) == UNIT_SRC_NORMAL)
                        printf("Normal\n");
                else
                        printf("Contains Data\n");
                printf("               Current Unit : %u\n",
                       __le32_to_cpu(migr_rec->curr_migr_unit));
                printf("                     Family : %u\n",
                       __le32_to_cpu(migr_rec->family_num));
                printf("                  Ascending : %u\n",
                       __le32_to_cpu(migr_rec->ascending_migr));
                printf("            Blocks Per Unit : %u\n",
                       __le32_to_cpu(migr_rec->blocks_per_unit));
                printf("       Dest. Depth Per Unit : %u\n",
                       __le32_to_cpu(migr_rec->dest_depth_per_unit));
                printf("        Checkpoint Area pba : %u\n",
                       __le32_to_cpu(migr_rec->ckpt_area_pba));
                printf("           First member lba : %u\n",
                       __le32_to_cpu(migr_rec->dest_1st_member_lba));
                printf("      Total Number of Units : %u\n",
                       __le32_to_cpu(migr_rec->num_migr_units));
                printf("             Size of volume : %u\n",
                       __le32_to_cpu(migr_rec->post_migr_vol_cap));
                printf("  Expansion space for LBA64 : %u\n",
                       __le32_to_cpu(migr_rec->post_migr_vol_cap_hi));
                printf("       Record was read from : %u\n",
                       __le32_to_cpu(migr_rec->ckpt_read_disk_num));

                break;
        }
}

static void getinfo_super_imsm(struct supertype *st, struct mdinfo *info, char *map);

static void examine_super_imsm(struct supertype *st, char *homehost)
{
        struct intel_super *super = st->sb;
        struct imsm_super *mpb = super->anchor;
        char str[MAX_SIGNATURE_LENGTH];
        int i;
        struct mdinfo info;
        char nbuf[64];
        __u32 sum;
        __u32 reserved = imsm_reserved_sectors(super, super->disks);
        struct dl *dl;

        snprintf(str, MPB_SIG_LEN, "%s", mpb->sig);
        printf("          Magic : %s\n", str);
        snprintf(str, strlen(MPB_VERSION_RAID0), "%s", get_imsm_version(mpb));
        printf("        Version : %s\n", get_imsm_version(mpb));
        printf("    Orig Family : %08x\n", __le32_to_cpu(mpb->orig_family_num));
        printf("         Family : %08x\n", __le32_to_cpu(mpb->family_num));
        printf("     Generation : %08x\n", __le32_to_cpu(mpb->generation_num));
        getinfo_super_imsm(st, &info, NULL);
        fname_from_uuid(st, &info, nbuf, ':');
        printf("           UUID : %s\n", nbuf + 5);
        sum = __le32_to_cpu(mpb->check_sum);
        printf("       Checksum : %08x %s\n", sum,
                __gen_imsm_checksum(mpb) == sum ? "correct" : "incorrect");
        printf("    MPB Sectors : %d\n", mpb_sectors(mpb));
        printf("          Disks : %d\n", mpb->num_disks);
        printf("   RAID Devices : %d\n", mpb->num_raid_devs);
        print_imsm_disk(mpb, super->disks->index, reserved);
        if (super->bbm_log) {
                struct bbm_log *log = super->bbm_log;

                printf("\n");
                printf("Bad Block Management Log:\n");
                printf("       Log Size : %d\n", __le32_to_cpu(mpb->bbm_log_size));
                printf("      Signature : %x\n", __le32_to_cpu(log->signature));
                printf("    Entry Count : %d\n", __le32_to_cpu(log->entry_count));
                printf("   Spare Blocks : %d\n",  __le32_to_cpu(log->reserved_spare_block_count));
                printf("    First Spare : %llx\n",
                       (unsigned long long) __le64_to_cpu(log->first_spare_lba));
        }
        for (i = 0; i < mpb->num_raid_devs; i++) {
                struct mdinfo info;
                struct imsm_dev *dev = __get_imsm_dev(mpb, i);

                super->current_vol = i;
                getinfo_super_imsm(st, &info, NULL);
                fname_from_uuid(st, &info, nbuf, ':');
                print_imsm_dev(super, dev, nbuf + 5, super->disks->index);
        }
        for (i = 0; i < mpb->num_disks; i++) {
                if (i == super->disks->index)
                        continue;
                print_imsm_disk(mpb, i, reserved);
        }
        for (dl = super->disks ; dl; dl = dl->next) {
                struct imsm_disk *disk;
                char str[MAX_RAID_SERIAL_LEN + 1];
                __u64 sz;

                if (dl->index >= 0)
                        continue;

                disk = &dl->disk;
                printf("\n");
                snprintf(str, MAX_RAID_SERIAL_LEN + 1, "%s", disk->serial);
                printf("    Disk Serial : %s\n", str);
                printf("          State :%s%s%s\n", is_spare(disk) ? " spare" : "",
                       is_configured(disk) ? " active" : "",
                       is_failed(disk) ? " failed" : "");
                printf("             Id : %08x\n", __le32_to_cpu(disk->scsi_id));
                sz = __le32_to_cpu(disk->total_blocks) - reserved;
                printf("    Usable Size : %llu%s\n", (unsigned long long)sz,
                       human_size(sz * 512));
        }

        examine_migr_rec_imsm(super);
}

static void brief_examine_super_imsm(struct supertype *st, int verbose)
{
        /* We just write a generic IMSM ARRAY entry */
        struct mdinfo info;
        char nbuf[64];
        struct intel_super *super = st->sb;

        if (!super->anchor->num_raid_devs) {
                printf("ARRAY metadata=imsm\n");
                return;
        }

        getinfo_super_imsm(st, &info, NULL);
        fname_from_uuid(st, &info, nbuf, ':');
        printf("ARRAY metadata=imsm UUID=%s\n", nbuf + 5);
}

static void brief_examine_subarrays_imsm(struct supertype *st, int verbose)
{
        /* We just write a generic IMSM ARRAY entry */
        struct mdinfo info;
        char nbuf[64];
        char nbuf1[64];
        struct intel_super *super = st->sb;
        int i;

        if (!super->anchor->num_raid_devs)
                return;

        getinfo_super_imsm(st, &info, NULL);
        fname_from_uuid(st, &info, nbuf, ':');
        for (i = 0; i < super->anchor->num_raid_devs; i++) {
                struct imsm_dev *dev = get_imsm_dev(super, i);

                super->current_vol = i;
                getinfo_super_imsm(st, &info, NULL);
                fname_from_uuid(st, &info, nbuf1, ':');
                printf("ARRAY /dev/md/%.16s container=%s member=%d UUID=%s\n",
                       dev->volume, nbuf + 5, i, nbuf1 + 5);
        }
}

static void export_examine_super_imsm(struct supertype *st)
{
        struct intel_super *super = st->sb;
        struct imsm_super *mpb = super->anchor;
        struct mdinfo info;
        char nbuf[64];

        getinfo_super_imsm(st, &info, NULL);
        fname_from_uuid(st, &info, nbuf, ':');
        printf("MD_METADATA=imsm\n");
        printf("MD_LEVEL=container\n");
        printf("MD_UUID=%s\n", nbuf+5);
        printf("MD_DEVICES=%u\n", mpb->num_disks);
}

static void detail_super_imsm(struct supertype *st, char *homehost)
{
        struct mdinfo info;
        char nbuf[64];

        getinfo_super_imsm(st, &info, NULL);
        fname_from_uuid(st, &info, nbuf, ':');
        printf("\n           UUID : %s\n", nbuf + 5);
}

static void brief_detail_super_imsm(struct supertype *st)
{
        struct mdinfo info;
        char nbuf[64];
        getinfo_super_imsm(st, &info, NULL);
        fname_from_uuid(st, &info, nbuf, ':');
        printf(" UUID=%s", nbuf + 5);
}

static int imsm_read_serial(int fd, char *devname, __u8 *serial);
static void fd2devname(int fd, char *name);

static int ahci_enumerate_ports(const char *hba_path, int port_count, int host_base, int verbose)
{
        /* dump an unsorted list of devices attached to AHCI Intel storage
         * controller, as well as non-connected ports
         */
        int hba_len = strlen(hba_path) + 1;
        struct dirent *ent;
        DIR *dir;
        char *path = NULL;
        int err = 0;
        unsigned long port_mask = (1 << port_count) - 1;

        if (port_count > (int)sizeof(port_mask) * 8) {
                if (verbose)
                        fprintf(stderr, Name ": port_count %d out of range\n", port_count);
                return 2;
        }

        /* scroll through /sys/dev/block looking for devices attached to
         * this hba
         */
        dir = opendir("/sys/dev/block");
        for (ent = dir ? readdir(dir) : NULL; ent; ent = readdir(dir)) {
                int fd;
                char model[64];
                char vendor[64];
                char buf[1024];
                int major, minor;
                char *device;
                char *c;
                int port;
                int type;

                if (sscanf(ent->d_name, "%d:%d", &major, &minor) != 2)
                        continue;
                path = devt_to_devpath(makedev(major, minor));
                if (!path)
                        continue;
                if (!path_attached_to_hba(path, hba_path)) {
                        free(path);
                        path = NULL;
                        continue;
                }

                /* retrieve the scsi device type */
                if (asprintf(&device, "/sys/dev/block/%d:%d/device/xxxxxxx", major, minor) < 0) {
                        if (verbose)
                                fprintf(stderr, Name ": failed to allocate 'device'\n");
                        err = 2;
                        break;
                }
                sprintf(device, "/sys/dev/block/%d:%d/device/type", major, minor);
                if (load_sys(device, buf) != 0) {
                        if (verbose)
                                fprintf(stderr, Name ": failed to read device type for %s\n",
                                        path);
                        err = 2;
                        free(device);
                        break;
                }
                type = strtoul(buf, NULL, 10);

                /* if it's not a disk print the vendor and model */
                if (!(type == 0 || type == 7 || type == 14)) {
                        vendor[0] = '\0';
                        model[0] = '\0';
                        sprintf(device, "/sys/dev/block/%d:%d/device/vendor", major, minor);
                        if (load_sys(device, buf) == 0) {
                                strncpy(vendor, buf, sizeof(vendor));
                                vendor[sizeof(vendor) - 1] = '\0';
                                c = (char *) &vendor[sizeof(vendor) - 1];
                                while (isspace(*c) || *c == '\0')
                                        *c-- = '\0';

                        }
                        sprintf(device, "/sys/dev/block/%d:%d/device/model", major, minor);
                        if (load_sys(device, buf) == 0) {
                                strncpy(model, buf, sizeof(model));
                                model[sizeof(model) - 1] = '\0';
                                c = (char *) &model[sizeof(model) - 1];
                                while (isspace(*c) || *c == '\0')
                                        *c-- = '\0';
                        }

                        if (vendor[0] && model[0])
                                sprintf(buf, "%.64s %.64s", vendor, model);
                        else
                                switch (type) { /* numbers from hald/linux/device.c */
                                case 1: sprintf(buf, "tape"); break;
                                case 2: sprintf(buf, "printer"); break;
                                case 3: sprintf(buf, "processor"); break;
                                case 4:
                                case 5: sprintf(buf, "cdrom"); break;
                                case 6: sprintf(buf, "scanner"); break;
                                case 8: sprintf(buf, "media_changer"); break;
                                case 9: sprintf(buf, "comm"); break;
                                case 12: sprintf(buf, "raid"); break;
                                default: sprintf(buf, "unknown");
                                }
                } else
                        buf[0] = '\0';
                free(device);

                /* chop device path to 'host%d' and calculate the port number */
                c = strchr(&path[hba_len], '/');
                if (!c) {
                        if (verbose)
                                fprintf(stderr, Name ": %s - invalid path name\n", path + hba_len);
                        err = 2;
                        break;
                }
                *c = '\0';
                if (sscanf(&path[hba_len], "host%d", &port) == 1)
                        port -= host_base;
                else {
                        if (verbose) {
                                *c = '/'; /* repair the full string */
                                fprintf(stderr, Name ": failed to determine port number for %s\n",
                                        path);
                        }
                        err = 2;
                        break;
                }

                /* mark this port as used */
                port_mask &= ~(1 << port);

                /* print out the device information */
                if (buf[0]) {
                        printf("          Port%d : - non-disk device (%s) -\n", port, buf);
                        continue;
                }

                fd = dev_open(ent->d_name, O_RDONLY);
                if (fd < 0)
                        printf("          Port%d : - disk info unavailable -\n", port);
                else {
                        fd2devname(fd, buf);
                        printf("          Port%d : %s", port, buf);
                        if (imsm_read_serial(fd, NULL, (__u8 *) buf) == 0)
                                printf(" (%s)\n", buf);
                        else
                                printf("()\n");
                }
                close(fd);
                free(path);
                path = NULL;
        }
        if (path)
                free(path);
        if (dir)
                closedir(dir);
        if (err == 0) {
                int i;

                for (i = 0; i < port_count; i++)
                        if (port_mask & (1 << i))
                                printf("          Port%d : - no device attached -\n", i);
        }

        return err;
}



static void print_found_intel_controllers(struct sys_dev *elem)
{
        for (; elem; elem = elem->next) {
                fprintf(stderr, Name ": found Intel(R) ");
                if (elem->type == SYS_DEV_SATA)
                        fprintf(stderr, "SATA ");
                else if (elem->type == SYS_DEV_SAS)
                        fprintf(stderr, "SAS ");
                fprintf(stderr, "RAID controller");
                if (elem->pci_id)
                        fprintf(stderr, " at %s", elem->pci_id);
                fprintf(stderr, ".\n");
        }
        fflush(stderr);
}

static int ahci_get_port_count(const char *hba_path, int *port_count)
{
        struct dirent *ent;
        DIR *dir;
        int host_base = -1;

        *port_count = 0;
        if ((dir = opendir(hba_path)) == NULL)
                return -1;

        for (ent = readdir(dir); ent; ent = readdir(dir)) {
                int host;

                if (sscanf(ent->d_name, "host%d", &host) != 1)
                        continue;
                if (*port_count == 0)
                        host_base = host;
                else if (host < host_base)
                        host_base = host;

                if (host + 1 > *port_count + host_base)
                        *port_count = host + 1 - host_base;
        }
        closedir(dir);
        return host_base;
}

static void print_imsm_capability(const struct imsm_orom *orom)
{
        printf("       Platform : Intel(R) Matrix Storage Manager\n");
        printf("        Version : %d.%d.%d.%d\n", orom->major_ver, orom->minor_ver,
               orom->hotfix_ver, orom->build);
        printf("    RAID Levels :%s%s%s%s%s\n",
               imsm_orom_has_raid0(orom) ? " raid0" : "",
               imsm_orom_has_raid1(orom) ? " raid1" : "",
               imsm_orom_has_raid1e(orom) ? " raid1e" : "",
               imsm_orom_has_raid10(orom) ? " raid10" : "",
               imsm_orom_has_raid5(orom) ? " raid5" : "");
        printf("    Chunk Sizes :%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n",
               imsm_orom_has_chunk(orom, 2) ? " 2k" : "",
               imsm_orom_has_chunk(orom, 4) ? " 4k" : "",
               imsm_orom_has_chunk(orom, 8) ? " 8k" : "",
               imsm_orom_has_chunk(orom, 16) ? " 16k" : "",
               imsm_orom_has_chunk(orom, 32) ? " 32k" : "",
               imsm_orom_has_chunk(orom, 64) ? " 64k" : "",
               imsm_orom_has_chunk(orom, 128) ? " 128k" : "",
               imsm_orom_has_chunk(orom, 256) ? " 256k" : "",
               imsm_orom_has_chunk(orom, 512) ? " 512k" : "",
               imsm_orom_has_chunk(orom, 1024*1) ? " 1M" : "",
               imsm_orom_has_chunk(orom, 1024*2) ? " 2M" : "",
               imsm_orom_has_chunk(orom, 1024*4) ? " 4M" : "",
               imsm_orom_has_chunk(orom, 1024*8) ? " 8M" : "",
               imsm_orom_has_chunk(orom, 1024*16) ? " 16M" : "",
               imsm_orom_has_chunk(orom, 1024*32) ? " 32M" : "",
               imsm_orom_has_chunk(orom, 1024*64) ? " 64M" : "");
        printf("      Max Disks : %d\n", orom->tds);
        printf("    Max Volumes : %d\n", orom->vpa);
        return;
}

static int detail_platform_imsm(int verbose, int enumerate_only)
{
        /* There are two components to imsm platform support, the ahci SATA
         * controller and the option-rom.  To find the SATA controller we
         * simply look in /sys/bus/pci/drivers/ahci to see if an ahci
         * controller with the Intel vendor id is present.  This approach
         * allows mdadm to leverage the kernel's ahci detection logic, with the
         * caveat that if ahci.ko is not loaded mdadm will not be able to
         * detect platform raid capabilities.  The option-rom resides in a
         * platform "Adapter ROM".  We scan for its signature to retrieve the
         * platform capabilities.  If raid support is disabled in the BIOS the
         * option-rom capability structure will not be available.
         */
        const struct imsm_orom *orom;
        struct sys_dev *list, *hba;
        int host_base = 0;
        int port_count = 0;
        int result=0;

        if (enumerate_only) {
                if (check_env("IMSM_NO_PLATFORM"))
                        return 0;
                list = find_intel_devices();
                if (!list)
                        return 2;
                for (hba = list; hba; hba = hba->next) {
                        orom = find_imsm_capability(hba->type);
                        if (!orom) {
                                result = 2;
                                break;
                        }
                }
                free_sys_dev(&list);
                return result;
        }

        list = find_intel_devices();
        if (!list) {
                if (verbose)
                        fprintf(stderr, Name ": no active Intel(R) RAID "
                                "controller found.\n");
                free_sys_dev(&list);
                return 2;
        } else if (verbose)
                print_found_intel_controllers(list);

        for (hba = list; hba; hba = hba->next) {
                orom = find_imsm_capability(hba->type);
                if (!orom)
                        fprintf(stderr, Name ": imsm capabilities not found for controller: %s (type %s)\n",
                                hba->path, get_sys_dev_type(hba->type));
                else
                        print_imsm_capability(orom);
        }

        for (hba = list; hba; hba = hba->next) {
                printf(" I/O Controller : %s (%s)\n",
                        hba->path, get_sys_dev_type(hba->type));

                if (hba->type == SYS_DEV_SATA) {
                        host_base = ahci_get_port_count(hba->path, &port_count);
                        if (ahci_enumerate_ports(hba->path, port_count, host_base, verbose)) {
                                if (verbose)
                                        fprintf(stderr, Name ": failed to enumerate "
                                                "ports on SATA controller at %s.", hba->pci_id);
                                result |= 2;
                        }
                }
        }

        free_sys_dev(&list);
        return result;
}
#endif

static int match_home_imsm(struct supertype *st, char *homehost)
{
        /* the imsm metadata format does not specify any host
         * identification information.  We return -1 since we can never
         * confirm nor deny whether a given array is "meant" for this
         * host.  We rely on compare_super and the 'family_num' fields to
         * exclude member disks that do not belong, and we rely on
         * mdadm.conf to specify the arrays that should be assembled.
         * Auto-assembly may still pick up "foreign" arrays.
         */

        return -1;
}

static void uuid_from_super_imsm(struct supertype *st, int uuid[4])
{
        /* The uuid returned here is used for:
         *  uuid to put into bitmap file (Create, Grow)
         *  uuid for backup header when saving critical section (Grow)
         *  comparing uuids when re-adding a device into an array
         *    In these cases the uuid required is that of the data-array,
         *    not the device-set.
         *  uuid to recognise same set when adding a missing device back
         *    to an array.   This is a uuid for the device-set.
         *  
         * For each of these we can make do with a truncated
         * or hashed uuid rather than the original, as long as
         * everyone agrees.
         * In each case the uuid required is that of the data-array,
         * not the device-set.
         */
        /* imsm does not track uuid's so we synthesis one using sha1 on
         * - The signature (Which is constant for all imsm array, but no matter)
         * - the orig_family_num of the container
         * - the index number of the volume
         * - the 'serial' number of the volume.
         * Hopefully these are all constant.
         */
        struct intel_super *super = st->sb;

        char buf[20];
        struct sha1_ctx ctx;
        struct imsm_dev *dev = NULL;
        __u32 family_num;

        /* some mdadm versions failed to set ->orig_family_num, in which
         * case fall back to ->family_num.  orig_family_num will be
         * fixed up with the first metadata update.
         */
        family_num = super->anchor->orig_family_num;
        if (family_num == 0)
                family_num = super->anchor->family_num;
        sha1_init_ctx(&ctx);
        sha1_process_bytes(super->anchor->sig, MPB_SIG_LEN, &ctx);
        sha1_process_bytes(&family_num, sizeof(__u32), &ctx);
        if (super->current_vol >= 0)
                dev = get_imsm_dev(super, super->current_vol);
        if (dev) {
                __u32 vol = super->current_vol;
                sha1_process_bytes(&vol, sizeof(vol), &ctx);
                sha1_process_bytes(dev->volume, MAX_RAID_SERIAL_LEN, &ctx);
        }
        sha1_finish_ctx(&ctx, buf);
        memcpy(uuid, buf, 4*4);
}

#if 0
static void
get_imsm_numerical_version(struct imsm_super *mpb, int *m, int *p)
{
        __u8 *v = get_imsm_version(mpb);
        __u8 *end = mpb->sig + MAX_SIGNATURE_LENGTH;
        char major[] = { 0, 0, 0 };
        char minor[] = { 0 ,0, 0 };
        char patch[] = { 0, 0, 0 };
        char *ver_parse[] = { major, minor, patch };
        int i, j;

        i = j = 0;
        while (*v != '\0' && v < end) {
                if (*v != '.' && j < 2)
                        ver_parse[i][j++] = *v;
                else {
                        i++;
                        j = 0;
                }
                v++;
        }

        *m = strtol(minor, NULL, 0);
        *p = strtol(patch, NULL, 0);
}
#endif

static __u32 migr_strip_blocks_resync(struct imsm_dev *dev)
{
        /* migr_strip_size when repairing or initializing parity */
        struct imsm_map *map = get_imsm_map(dev, 0);
        __u32 chunk = __le32_to_cpu(map->blocks_per_strip);

        switch (get_imsm_raid_level(map)) {
        case 5:
        case 10:
                return chunk;
        default:
                return 128*1024 >> 9;
        }
}

static __u32 migr_strip_blocks_rebuild(struct imsm_dev *dev)
{
        /* migr_strip_size when rebuilding a degraded disk, no idea why
         * this is different than migr_strip_size_resync(), but it's good
         * to be compatible
         */
        struct imsm_map *map = get_imsm_map(dev, 1);
        __u32 chunk = __le32_to_cpu(map->blocks_per_strip);

        switch (get_imsm_raid_level(map)) {
        case 1:
        case 10:
                if (map->num_members % map->num_domains == 0)
                        return 128*1024 >> 9;
                else
                        return chunk;
        case 5:
                return max((__u32) 64*1024 >> 9, chunk);
        default:
                return 128*1024 >> 9;
        }
}

static __u32 num_stripes_per_unit_resync(struct imsm_dev *dev)
{
        struct imsm_map *lo = get_imsm_map(dev, 0);
        struct imsm_map *hi = get_imsm_map(dev, 1);
        __u32 lo_chunk = __le32_to_cpu(lo->blocks_per_strip);
        __u32 hi_chunk = __le32_to_cpu(hi->blocks_per_strip);

        return max((__u32) 1, hi_chunk / lo_chunk);
}

static __u32 num_stripes_per_unit_rebuild(struct imsm_dev *dev)
{
        struct imsm_map *lo = get_imsm_map(dev, 0);
        int level = get_imsm_raid_level(lo);

        if (level == 1 || level == 10) {
                struct imsm_map *hi = get_imsm_map(dev, 1);

                return hi->num_domains;
        } else
                return num_stripes_per_unit_resync(dev);
}

static __u8 imsm_num_data_members(struct imsm_dev *dev, int second_map)
{
        /* named 'imsm_' because raid0, raid1 and raid10
         * counter-intuitively have the same number of data disks
         */
        struct imsm_map *map = get_imsm_map(dev, second_map);

        switch (get_imsm_raid_level(map)) {
        case 0:
        case 1:
        case 10:
                return map->num_members;
        case 5:
                return map->num_members - 1;
        default:
                dprintf("%s: unsupported raid level\n", __func__);
                return 0;
        }
}

static __u32 parity_segment_depth(struct imsm_dev *dev)
{
        struct imsm_map *map = get_imsm_map(dev, 0);
        __u32 chunk =  __le32_to_cpu(map->blocks_per_strip);

        switch(get_imsm_raid_level(map)) {
        case 1:
        case 10:
                return chunk * map->num_domains;
        case 5:
                return chunk * map->num_members;
        default:
                return chunk;
        }
}

static __u32 map_migr_block(struct imsm_dev *dev, __u32 block)
{
        struct imsm_map *map = get_imsm_map(dev, 1);
        __u32 chunk = __le32_to_cpu(map->blocks_per_strip);
        __u32 strip = block / chunk;

        switch (get_imsm_raid_level(map)) {
        case 1:
        case 10: {
                __u32 vol_strip = (strip * map->num_domains) + 1;
                __u32 vol_stripe = vol_strip / map->num_members;

                return vol_stripe * chunk + block % chunk;
        } case 5: {
                __u32 stripe = strip / (map->num_members - 1);

                return stripe * chunk + block % chunk;
        }
        default:
                return 0;
        }
}

static __u64 blocks_per_migr_unit(struct intel_super *super,
                                  struct imsm_dev *dev)
{
        /* calculate the conversion factor between per member 'blocks'
         * (md/{resync,rebuild}_start) and imsm migration units, return
         * 0 for the 'not migrating' and 'unsupported migration' cases
         */
        if (!dev->vol.migr_state)
                return 0;

        switch (migr_type(dev)) {
        case MIGR_GEN_MIGR: {
                struct migr_record *migr_rec = super->migr_rec;
                return __le32_to_cpu(migr_rec->blocks_per_unit);
        }
        case MIGR_VERIFY:
        case MIGR_REPAIR:
        case MIGR_INIT: {
                struct imsm_map *map = get_imsm_map(dev, 0);
                __u32 stripes_per_unit;
                __u32 blocks_per_unit;
                __u32 parity_depth;
                __u32 migr_chunk;
                __u32 block_map;
                __u32 block_rel;
                __u32 segment;
                __u32 stripe;
                __u8  disks;

                /* yes, this is really the translation of migr_units to
                 * per-member blocks in the 'resync' case
                 */
                stripes_per_unit = num_stripes_per_unit_resync(dev);
                migr_chunk = migr_strip_blocks_resync(dev);
                disks = imsm_num_data_members(dev, 0);
                blocks_per_unit = stripes_per_unit * migr_chunk * disks;
                stripe = __le32_to_cpu(map->blocks_per_strip) * disks;
                segment = blocks_per_unit / stripe;
                block_rel = blocks_per_unit - segment * stripe;
                parity_depth = parity_segment_depth(dev);
                block_map = map_migr_block(dev, block_rel);
                return block_map + parity_depth * segment;
        }
        case MIGR_REBUILD: {
                __u32 stripes_per_unit;
                __u32 migr_chunk;

                stripes_per_unit = num_stripes_per_unit_rebuild(dev);
                migr_chunk = migr_strip_blocks_rebuild(dev);
                return migr_chunk * stripes_per_unit;
        }
        case MIGR_STATE_CHANGE:
        default:
                return 0;
        }
}

static int imsm_level_to_layout(int level)
{
        switch (level) {
        case 0:
        case 1:
                return 0;
        case 5:
        case 6:
                return ALGORITHM_LEFT_ASYMMETRIC;
        case 10:
                return 0x102;
        }
        return UnSet;
}

/*******************************************************************************
 * Function:    read_imsm_migr_rec
 * Description: Function reads imsm migration record from last sector of disk
 * Parameters:
 *      fd      : disk descriptor
 *      super   : metadata info
 * Returns:
 *       0 : success,
 *      -1 : fail
 ******************************************************************************/
static int read_imsm_migr_rec(int fd, struct intel_super *super)
{
        int ret_val = -1;
        unsigned long long dsize;

        get_dev_size(fd, NULL, &dsize);
        if (lseek64(fd, dsize - 512, SEEK_SET) < 0) {
                fprintf(stderr,
                        Name ": Cannot seek to anchor block: %s\n",
                        strerror(errno));
                goto out;
        }
        if (read(fd, super->migr_rec_buf, 512) != 512) {
                fprintf(stderr,
                        Name ": Cannot read migr record block: %s\n",
                        strerror(errno));
                goto out;
        }
        ret_val = 0;

out:
        return ret_val;
}

/*******************************************************************************
 * Function:    load_imsm_migr_rec
 * Description: Function reads imsm migration record (it is stored at the last
 *              sector of disk)
 * Parameters:
 *      super   : imsm internal array info
 *      info    : general array info
 * Returns:
 *       0 : success
 *      -1 : fail
 ******************************************************************************/
static int load_imsm_migr_rec(struct intel_super *super, struct mdinfo *info)
{
        struct mdinfo *sd;
        struct dl *dl = NULL;
        char nm[30];
        int retval = -1;
        int fd = -1;

        if (info) {
                for (sd = info->devs ; sd ; sd = sd->next) {
                        /* read only from one of the first two slots */
                        if ((sd->disk.raid_disk > 1) ||
                            (sd->disk.raid_disk < 0))
                                continue;
                        sprintf(nm, "%d:%d", sd->disk.major, sd->disk.minor);
                        fd = dev_open(nm, O_RDONLY);
                        if (fd >= 0)
                                break;
                }
        }
        if (fd < 0) {
                for (dl = super->disks; dl; dl = dl->next) {
                        /* read only from one of the first two slots */
                        if (dl->index > 1)
                                continue;
                        sprintf(nm, "%d:%d", dl->major, dl->minor);
                        fd = dev_open(nm, O_RDONLY);
                        if (fd >= 0)
                                break;
                }
        }
        if (fd < 0)
                goto out;
        retval = read_imsm_migr_rec(fd, super);

out:
        if (fd >= 0)
                close(fd);
        return retval;
}

/*******************************************************************************
 * function: imsm_create_metadata_checkpoint_update
 * Description: It creates update for checkpoint change.
 * Parameters:
 *      super   : imsm internal array info
 *      u       : pointer to prepared update
 * Returns:
 *      Uptate length.
 *      If length is equal to 0, input pointer u contains no update
 ******************************************************************************/
static int imsm_create_metadata_checkpoint_update(
        struct intel_super *super,
        struct imsm_update_general_migration_checkpoint **u)
{

        int update_memory_size = 0;

        dprintf("imsm_create_metadata_checkpoint_update(enter)\n");

        if (u == NULL)
                return 0;
        *u = NULL;

        /* size of all update data without anchor */
        update_memory_size =
                sizeof(struct imsm_update_general_migration_checkpoint);

        *u = calloc(1, update_memory_size);
        if (*u == NULL) {
                dprintf("error: cannot get memory for "
                        "imsm_create_metadata_checkpoint_update update\n");
                return 0;
        }
        (*u)->type = update_general_migration_checkpoint;
        (*u)->curr_migr_unit = __le32_to_cpu(super->migr_rec->curr_migr_unit);
        dprintf("imsm_create_metadata_checkpoint_update: prepared for %u\n",
                (*u)->curr_migr_unit);

        return update_memory_size;
}


static void imsm_update_metadata_locally(struct supertype *st,
                                         void *buf, int len);

/*******************************************************************************
 * Function:    write_imsm_migr_rec
 * Description: Function writes imsm migration record
 *              (at the last sector of disk)
 * Parameters:
 *      super   : imsm internal array info
 * Returns:
 *       0 : success
 *      -1 : if fail
 ******************************************************************************/
static int write_imsm_migr_rec(struct supertype *st)
{
        struct intel_super *super = st->sb;
        unsigned long long dsize;
        char nm[30];
        int fd = -1;
        int retval = -1;
        struct dl *sd;
        int len;
        struct imsm_update_general_migration_checkpoint *u;

        for (sd = super->disks ; sd ; sd = sd->next) {
                /* write to 2 first slots only */
                if ((sd->index < 0) || (sd->index > 1))
                        continue;
                sprintf(nm, "%d:%d", sd->major, sd->minor);
                fd = dev_open(nm, O_RDWR);
                if (fd < 0)
                        continue;
                get_dev_size(fd, NULL, &dsize);
                if (lseek64(fd, dsize - 512, SEEK_SET) < 0) {
                        fprintf(stderr,
                                Name ": Cannot seek to anchor block: %s\n",
                                strerror(errno));
                        goto out;
                }
                if (write(fd, super->migr_rec_buf, 512) != 512) {
                        fprintf(stderr,
                                Name ": Cannot write migr record block: %s\n",
                                strerror(errno));
                        goto out;
                }
                close(fd);
                fd = -1;
        }
        /* update checkpoint information in metadata */
        len = imsm_create_metadata_checkpoint_update(super, &u);

        if (len <= 0) {
                dprintf("imsm: Cannot prepare update\n");
                goto out;
        }
        /* update metadata locally */
        imsm_update_metadata_locally(st, u, len);
        /* and possibly remotely */
        if (st->update_tail) {
                append_metadata_update(st, u, len);
                /* during reshape we do all work inside metadata handler
                 * manage_reshape(), so metadata update has to be triggered
                 * insida it
                 */
                flush_metadata_updates(st);
                st->update_tail = &st->updates;
        } else
                free(u);

        retval = 0;
 out:
        if (fd >= 0)
                close(fd);
        return retval;
}

static void getinfo_super_imsm_volume(struct supertype *st, struct mdinfo *info, char *dmap)
{
        struct intel_super *super = st->sb;
        struct migr_record *migr_rec = super->migr_rec;
        struct imsm_dev *dev = get_imsm_dev(super, super->current_vol);
        struct imsm_map *map = get_imsm_map(dev, 0);
        struct imsm_map *prev_map = get_imsm_map(dev, 1);
        struct imsm_map *map_to_analyse = map;
        struct dl *dl;
        char *devname;
        unsigned int component_size_alligment;
        int map_disks = info->array.raid_disks;

        memset(info, 0, sizeof(*info));
        if (prev_map)
                map_to_analyse = prev_map;

        for (dl = super->disks; dl; dl = dl->next)
                if (dl->raiddisk == info->disk.raid_disk)
                        break;
        info->container_member    = super->current_vol;
        info->array.raid_disks    = map->num_members;
        info->array.level         = get_imsm_raid_level(map_to_analyse);
        info->array.layout        = imsm_level_to_layout(info->array.level);
        info->array.md_minor      = -1;
        info->array.ctime         = 0;
        info->array.utime         = 0;
        info->array.chunk_size    =
                __le16_to_cpu(map_to_analyse->blocks_per_strip) << 9;
        info->array.state         = !dev->vol.dirty;
        info->custom_array_size   = __le32_to_cpu(dev->size_high);
        info->custom_array_size   <<= 32;
        info->custom_array_size   |= __le32_to_cpu(dev->size_low);
        if (prev_map && map->map_state == prev_map->map_state) {
                info->reshape_active = 1;
                info->new_level = get_imsm_raid_level(map);
                info->new_layout = imsm_level_to_layout(info->new_level);
                info->new_chunk = __le16_to_cpu(map->blocks_per_strip) << 9;
                info->delta_disks = map->num_members - prev_map->num_members;
                if (info->delta_disks) {
                        /* this needs to be applied to every array
                         * in the container.
                         */
                        info->reshape_active = 2;
                }
                /* We shape information that we give to md might have to be
                 * modify to cope with md's requirement for reshaping arrays.
                 * For example, when reshaping a RAID0, md requires it to be
                 * presented as a degraded RAID4.
                 * Also if a RAID0 is migrating to a RAID5 we need to specify
                 * the array as already being RAID5, but the 'before' layout
                 * is a RAID4-like layout.
                 */
                switch (info->array.level) {
                case 0:
                        switch(info->new_level) {
                        case 0:
                                /* conversion is happening as RAID4 */
                                info->array.level = 4;
                                info->array.raid_disks += 1;
                                break;
                        case 5:
                                /* conversion is happening as RAID5 */
                                info->array.level = 5;
                                info->array.layout = ALGORITHM_PARITY_N;
                                info->array.raid_disks += 1;
                                info->delta_disks -= 1;
                                break;
                        default:
                                /* FIXME error message */
                                info->array.level = UnSet;
                                break;
                        }
                        break;
                }
        } else {
                info->new_level = UnSet;
                info->new_layout = UnSet;
                info->new_chunk = info->array.chunk_size;
                info->delta_disks = 0;
        }
        info->disk.major = 0;
        info->disk.minor = 0;
        if (dl) {
                info->disk.major = dl->major;
                info->disk.minor = dl->minor;
        }

        info->data_offset         = __le32_to_cpu(map_to_analyse->pba_of_lba0);
        info->component_size      =
                __le32_to_cpu(map_to_analyse->blocks_per_member);

        /* check component size aligment
         */
        component_size_alligment =
                info->component_size % (info->array.chunk_size/512);

        if (component_size_alligment &&
            (info->array.level != 1) && (info->array.level != UnSet)) {
                dprintf("imsm: reported component size alligned from %llu ",
                        info->component_size);
                info->component_size -= component_size_alligment;
                dprintf("to %llu (%i).\n",
                        info->component_size, component_size_alligment);
        }

        memset(info->uuid, 0, sizeof(info->uuid));
        info->recovery_start = MaxSector;

        info->reshape_progress = 0;
        info->resync_start = MaxSector;
        if (map_to_analyse->map_state == IMSM_T_STATE_UNINITIALIZED ||
            dev->vol.dirty) {
                info->resync_start = 0;
        }
        if (dev->vol.migr_state) {
                switch (migr_type(dev)) {
                case MIGR_REPAIR:
                case MIGR_INIT: {
                        __u64 blocks_per_unit = blocks_per_migr_unit(super,
                                                                     dev);
                        __u64 units = __le32_to_cpu(dev->vol.curr_migr_unit);

                        info->resync_start = blocks_per_unit * units;
                        break;
                }
                case MIGR_GEN_MIGR: {
                        __u64 blocks_per_unit = blocks_per_migr_unit(super,
                                                                     dev);
                        __u64 units = __le32_to_cpu(migr_rec->curr_migr_unit);
                        unsigned long long array_blocks;
                        int used_disks;

                        info->reshape_progress = blocks_per_unit * units;

                        dprintf("IMSM: General Migration checkpoint : %llu "
                               "(%llu) -> read reshape progress : %llu\n",
                                units, blocks_per_unit, info->reshape_progress);

                        used_disks = imsm_num_data_members(dev, 1);
                        if (used_disks > 0) {
                                array_blocks = map->blocks_per_member *
                                        used_disks;
                                /* round array size down to closest MB
                                 */
                                info->custom_array_size = (array_blocks
                                                >> SECT_PER_MB_SHIFT)
                                                << SECT_PER_MB_SHIFT;
                        }
                }
                case MIGR_VERIFY:
                        /* we could emulate the checkpointing of
                         * 'sync_action=check' migrations, but for now
                         * we just immediately complete them
                         */
                case MIGR_REBUILD:
                        /* this is handled by container_content_imsm() */
                case MIGR_STATE_CHANGE:
                        /* FIXME handle other migrations */
                default:
                        /* we are not dirty, so... */
                        info->resync_start = MaxSector;
                }
        }

        strncpy(info->name, (char *) dev->volume, MAX_RAID_SERIAL_LEN);
        info->name[MAX_RAID_SERIAL_LEN] = 0;

        info->array.major_version = -1;
        info->array.minor_version = -2;
        devname = devnum2devname(st->container_dev);
        *info->text_version = '\0';
        if (devname)
                sprintf(info->text_version, "/%s/%d", devname, info->container_member);
        free(devname);
        info->safe_mode_delay = 4000;  /* 4 secs like the Matrix driver */
        uuid_from_super_imsm(st, info->uuid);

        if (dmap) {
                int i, j;
                for (i=0; i<map_disks; i++) {
                        dmap[i] = 0;
                        if (i < info->array.raid_disks) {
                                struct imsm_disk *dsk;
                                j = get_imsm_disk_idx(dev, i, -1);
                                dsk = get_imsm_disk(super, j);
                                if (dsk && (dsk->status & CONFIGURED_DISK))
                                        dmap[i] = 1;
                        }
                }
        }
}

static __u8 imsm_check_degraded(struct intel_super *super, struct imsm_dev *dev, int failed);
static int imsm_count_failed(struct intel_super *super, struct imsm_dev *dev);

static struct imsm_disk *get_imsm_missing(struct intel_super *super, __u8 index)
{
        struct dl *d;

        for (d = super->missing; d; d = d->next)
                if (d->index == index)
                        return &d->disk;
        return NULL;
}

static void getinfo_super_imsm(struct supertype *st, struct mdinfo *info, char *map)
{
        struct intel_super *super = st->sb;
        struct imsm_disk *disk;
        int map_disks = info->array.raid_disks;
        int max_enough = -1;
        int i;
        struct imsm_super *mpb;

        if (super->current_vol >= 0) {
                getinfo_super_imsm_volume(st, info, map);
                return;
        }
        memset(info, 0, sizeof(*info));

        /* Set raid_disks to zero so that Assemble will always pull in valid
         * spares
         */
        info->array.raid_disks    = 0;
        info->array.level         = LEVEL_CONTAINER;
        info->array.layout        = 0;
        info->array.md_minor      = -1;
        info->array.ctime         = 0; /* N/A for imsm */ 
        info->array.utime         = 0;
        info->array.chunk_size    = 0;

        info->disk.major = 0;
        info->disk.minor = 0;
        info->disk.raid_disk = -1;
        info->reshape_active = 0;
        info->array.major_version = -1;
        info->array.minor_version = -2;
        strcpy(info->text_version, "imsm");
        info->safe_mode_delay = 0;
        info->disk.number = -1;
        info->disk.state = 0;
        info->name[0] = 0;
        info->recovery_start = MaxSector;

        /* do we have the all the insync disks that we expect? */
        mpb = super->anchor;

        for (i = 0; i < mpb->num_raid_devs; i++) {
                struct imsm_dev *dev = get_imsm_dev(super, i);
                int failed, enough, j, missing = 0;
                struct imsm_map *map;
                __u8 state;

                failed = imsm_count_failed(super, dev);
                state = imsm_check_degraded(super, dev, failed);
                map = get_imsm_map(dev, dev->vol.migr_state);

                /* any newly missing disks?
                 * (catches single-degraded vs double-degraded)
                 */
                for (j = 0; j < map->num_members; j++) {
                        __u32 ord = get_imsm_ord_tbl_ent(dev, i, -1);
                        __u32 idx = ord_to_idx(ord);

                        if (!(ord & IMSM_ORD_REBUILD) &&
                            get_imsm_missing(super, idx)) {
                                missing = 1;
                                break;
                        }
                }

                if (state == IMSM_T_STATE_FAILED)
                        enough = -1;
                else if (state == IMSM_T_STATE_DEGRADED &&
                         (state != map->map_state || missing))
                        enough = 0;
                else /* we're normal, or already degraded */
                        enough = 1;

                /* in the missing/failed disk case check to see
                 * if at least one array is runnable
                 */
                max_enough = max(max_enough, enough);
        }
        dprintf("%s: enough: %d\n", __func__, max_enough);
        info->container_enough = max_enough;

        if (super->disks) {
                __u32 reserved = imsm_reserved_sectors(super, super->disks);

                disk = &super->disks->disk;
                info->data_offset = __le32_to_cpu(disk->total_blocks) - reserved;
                info->component_size = reserved;
                info->disk.state  = is_configured(disk) ? (1 << MD_DISK_ACTIVE) : 0;
                /* we don't change info->disk.raid_disk here because
                 * this state will be finalized in mdmon after we have
                 * found the 'most fresh' version of the metadata
                 */
                info->disk.state |= is_failed(disk) ? (1 << MD_DISK_FAULTY) : 0;
                info->disk.state |= is_spare(disk) ? 0 : (1 << MD_DISK_SYNC);
        }

        /* only call uuid_from_super_imsm when this disk is part of a populated container,
         * ->compare_super may have updated the 'num_raid_devs' field for spares
         */
        if (info->disk.state & (1 << MD_DISK_SYNC) || super->anchor->num_raid_devs)
                uuid_from_super_imsm(st, info->uuid);
        else
                memcpy(info->uuid, uuid_zero, sizeof(uuid_zero));

        /* I don't know how to compute 'map' on imsm, so use safe default */
        if (map) {
                int i;
                for (i = 0; i < map_disks; i++)
                        map[i] = 1;
        }

}

/* allocates memory and fills disk in mdinfo structure
 * for each disk in array */
struct mdinfo *getinfo_super_disks_imsm(struct supertype *st)
{
        struct mdinfo *mddev = NULL;
        struct intel_super *super = st->sb;
        struct imsm_disk *disk;
        int count = 0;
        struct dl *dl;
        if (!super || !super->disks)
                return NULL;
        dl = super->disks;
        mddev = malloc(sizeof(*mddev));
        if (!mddev) {
                fprintf(stderr, Name ": Failed to allocate memory.\n");
                return NULL;
        }
        memset(mddev, 0, sizeof(*mddev));
        while (dl) {
                struct mdinfo *tmp;
                disk = &dl->disk;
                tmp = malloc(sizeof(*tmp));
                if (!tmp) {
                        fprintf(stderr, Name ": Failed to allocate memory.\n");
                        if (mddev)
                                sysfs_free(mddev);
                        return NULL;
                }
                memset(tmp, 0, sizeof(*tmp));
                if (mddev->devs)
                        tmp->next = mddev->devs;
                mddev->devs = tmp;
                tmp->disk.number = count++;
                tmp->disk.major = dl->major;
                tmp->disk.minor = dl->minor;
                tmp->disk.state = is_configured(disk) ?
                                  (1 << MD_DISK_ACTIVE) : 0;
                tmp->disk.state |= is_failed(disk) ? (1 << MD_DISK_FAULTY) : 0;
                tmp->disk.state |= is_spare(disk) ? 0 : (1 << MD_DISK_SYNC);
                tmp->disk.raid_disk = -1;
                dl = dl->next;
        }
        return mddev;
}

static int update_super_imsm(struct supertype *st, struct mdinfo *info,
                             char *update, char *devname, int verbose,
                             int uuid_set, char *homehost)
{
        /* For 'assemble' and 'force' we need to return non-zero if any
         * change was made.  For others, the return value is ignored.
         * Update options are:
         *  force-one : This device looks a bit old but needs to be included,
         *        update age info appropriately.
         *  assemble: clear any 'faulty' flag to allow this device to
         *              be assembled.
         *  force-array: Array is degraded but being forced, mark it clean
         *         if that will be needed to assemble it.
         *
         *  newdev:  not used ????
         *  grow:  Array has gained a new device - this is currently for
         *              linear only
         *  resync: mark as dirty so a resync will happen.
         *  name:  update the name - preserving the homehost
         *  uuid:  Change the uuid of the array to match watch is given
         *
         * Following are not relevant for this imsm:
         *  sparc2.2 : update from old dodgey metadata
         *  super-minor: change the preferred_minor number
         *  summaries:  update redundant counters.
         *  homehost:  update the recorded homehost
         *  _reshape_progress: record new reshape_progress position.
         */
        int rv = 1;
        struct intel_super *super = st->sb;
        struct imsm_super *mpb;

        /* we can only update container info */
        if (!super || super->current_vol >= 0 || !super->anchor)
                return 1;

        mpb = super->anchor;

        if (strcmp(update, "uuid") == 0 && uuid_set && !info->update_private)
                rv = -1;
        else if (strcmp(update, "uuid") == 0 && uuid_set && info->update_private) {
                mpb->orig_family_num = *((__u32 *) info->update_private);
                rv = 0;
        } else if (strcmp(update, "uuid") == 0) {
                __u32 *new_family = malloc(sizeof(*new_family));

                /* update orig_family_number with the incoming random
                 * data, report the new effective uuid, and store the
                 * new orig_family_num for future updates.
                 */
                if (new_family) {
                        memcpy(&mpb->orig_family_num, info->uuid, sizeof(__u32));
                        uuid_from_super_imsm(st, info->uuid);
                        *new_family = mpb->orig_family_num;
                        info->update_private = new_family;
                        rv = 0;
                }
        } else if (strcmp(update, "assemble") == 0)
                rv = 0;
        else
                rv = -1;

        /* successful update? recompute checksum */
        if (rv == 0)
                mpb->check_sum = __le32_to_cpu(__gen_imsm_checksum(mpb));

        return rv;
}

static size_t disks_to_mpb_size(int disks)
{
        size_t size;

        size = sizeof(struct imsm_super);
        size += (disks - 1) * sizeof(struct imsm_disk);
        size += 2 * sizeof(struct imsm_dev);
        /* up to 2 maps per raid device (-2 for imsm_maps in imsm_dev */
        size += (4 - 2) * sizeof(struct imsm_map);
        /* 4 possible disk_ord_tbl's */
        size += 4 * (disks - 1) * sizeof(__u32);

        return size;
}

static __u64 avail_size_imsm(struct supertype *st, __u64 devsize)
{
        if (devsize < (MPB_SECTOR_CNT + IMSM_RESERVED_SECTORS))
                return 0;

        return devsize - (MPB_SECTOR_CNT + IMSM_RESERVED_SECTORS);
}

static void free_devlist(struct intel_super *super)
{
        struct intel_dev *dv;

        while (super->devlist) {
                dv = super->devlist->next;
                free(super->devlist->dev);
                free(super->devlist);
                super->devlist = dv;
        }
}

static void imsm_copy_dev(struct imsm_dev *dest, struct imsm_dev *src)
{
        memcpy(dest, src, sizeof_imsm_dev(src, 0));
}

static int compare_super_imsm(struct supertype *st, struct supertype *tst)
{
        /*
         * return:
         *  0 same, or first was empty, and second was copied
         *  1 second had wrong number
         *  2 wrong uuid
         *  3 wrong other info
         */
        struct intel_super *first = st->sb;
        struct intel_super *sec = tst->sb;

        if (!first) {
                st->sb = tst->sb;
                tst->sb = NULL;
                return 0;
        }
        /* in platform dependent environment test if the disks
         * use the same Intel hba
         */
        if (!check_env("IMSM_NO_PLATFORM")) {
                if (!first->hba || !sec->hba ||
                    (first->hba->type != sec->hba->type))  {
                        fprintf(stderr,
                                "HBAs of devices does not match %s != %s\n",
                                first->hba ? get_sys_dev_type(first->hba->type) : NULL,
                                sec->hba ? get_sys_dev_type(sec->hba->type) : NULL);
                        return 3;
                }
        }

        /* if an anchor does not have num_raid_devs set then it is a free
         * floating spare
         */
        if (first->anchor->num_raid_devs > 0 &&
            sec->anchor->num_raid_devs > 0) {
                /* Determine if these disks might ever have been
                 * related.  Further disambiguation can only take place
                 * in load_super_imsm_all
                 */
                __u32 first_family = first->anchor->orig_family_num;
                __u32 sec_family = sec->anchor->orig_family_num;

                if (memcmp(first->anchor->sig, sec->anchor->sig,
                           MAX_SIGNATURE_LENGTH) != 0)
                        return 3;

                if (first_family == 0)
                        first_family = first->anchor->family_num;
                if (sec_family == 0)
                        sec_family = sec->anchor->family_num;

                if (first_family != sec_family)
                        return 3;

        }


        /* if 'first' is a spare promote it to a populated mpb with sec's
         * family number
         */
        if (first->anchor->num_raid_devs == 0 &&
            sec->anchor->num_raid_devs > 0) {
                int i;
                struct intel_dev *dv;
                struct imsm_dev *dev;

                /* we need to copy raid device info from sec if an allocation
                 * fails here we don't associate the spare
                 */
                for (i = 0; i < sec->anchor->num_raid_devs; i++) {
                        dv = malloc(sizeof(*dv));
                        if (!dv)
                                break;
                        dev = malloc(sizeof_imsm_dev(get_imsm_dev(sec, i), 1));
                        if (!dev) {
                                free(dv);
                                break;
                        }
                        dv->dev = dev;
                        dv->index = i;
                        dv->next = first->devlist;
                        first->devlist = dv;
                }
                if (i < sec->anchor->num_raid_devs) {
                        /* allocation failure */
                        free_devlist(first);
                        fprintf(stderr, "imsm: failed to associate spare\n"); 
                        return 3;
                }
                first->anchor->num_raid_devs = sec->anchor->num_raid_devs;
                first->anchor->orig_family_num = sec->anchor->orig_family_num;
                first->anchor->family_num = sec->anchor->family_num;
                memcpy(first->anchor->sig, sec->anchor->sig, MAX_SIGNATURE_LENGTH);
                for (i = 0; i < sec->anchor->num_raid_devs; i++)
                        imsm_copy_dev(get_imsm_dev(first, i), get_imsm_dev(sec, i));
        }

        return 0;
}

static void fd2devname(int fd, char *name)
{
        struct stat st;
        char path[256];
        char dname[PATH_MAX];
        char *nm;
        int rv;

        name[0] = '\0';
        if (fstat(fd, &st) != 0)
                return;
        sprintf(path, "/sys/dev/block/%d:%d",
                major(st.st_rdev), minor(st.st_rdev));

        rv = readlink(path, dname, sizeof(dname));
        if (rv <= 0)
                return;
        
        dname[rv] = '\0';
        nm = strrchr(dname, '/');
        nm++;
        snprintf(name, MAX_RAID_SERIAL_LEN, "/dev/%s", nm);
}

extern int scsi_get_serial(int fd, void *buf, size_t buf_len);

static int imsm_read_serial(int fd, char *devname,
                            __u8 serial[MAX_RAID_SERIAL_LEN])
{
        unsigned char scsi_serial[255];
        int rv;
        int rsp_len;
        int len;
        char *dest;
        char *src;
        char *rsp_buf;
        int i;

        memset(scsi_serial, 0, sizeof(scsi_serial));

        rv = scsi_get_serial(fd, scsi_serial, sizeof(scsi_serial));

        if (rv && check_env("IMSM_DEVNAME_AS_SERIAL")) {
                memset(serial, 0, MAX_RAID_SERIAL_LEN);
                fd2devname(fd, (char *) serial);
                return 0;
        }

        if (rv != 0) {
                if (devname)
                        fprintf(stderr,
                                Name ": Failed to retrieve serial for %s\n",
                                devname);
                return rv;
        }

        rsp_len = scsi_serial[3];
        if (!rsp_len) {
                if (devname)
                        fprintf(stderr,
                                Name ": Failed to retrieve serial for %s\n",
                                devname);
                return 2;
        }
        rsp_buf = (char *) &scsi_serial[4];

        /* trim all whitespace and non-printable characters and convert
         * ':' to ';'
         */
        for (i = 0, dest = rsp_buf; i < rsp_len; i++) {
                src = &rsp_buf[i];
                if (*src > 0x20) {
                        /* ':' is reserved for use in placeholder serial
                         * numbers for missing disks
                         */
                        if (*src == ':')
                                *dest++ = ';';
                        else
                                *dest++ = *src;
                }
        }
        len = dest - rsp_buf;
        dest = rsp_buf;

        /* truncate leading characters */
        if (len > MAX_RAID_SERIAL_LEN) {
                dest += len - MAX_RAID_SERIAL_LEN;
                len = MAX_RAID_SERIAL_LEN;
        }

        memset(serial, 0, MAX_RAID_SERIAL_LEN);
        memcpy(serial, dest, len);

        return 0;
}

static int serialcmp(__u8 *s1, __u8 *s2)
{
        return strncmp((char *) s1, (char *) s2, MAX_RAID_SERIAL_LEN);
}

static void serialcpy(__u8 *dest, __u8 *src)
{
        strncpy((char *) dest, (char *) src, MAX_RAID_SERIAL_LEN);
}

#ifndef MDASSEMBLE
static struct dl *serial_to_dl(__u8 *serial, struct intel_super *super)
{
        struct dl *dl;

        for (dl = super->disks; dl; dl = dl->next)
                if (serialcmp(dl->serial, serial) == 0)
                        break;

        return dl;
}
#endif

static struct imsm_disk *
__serial_to_disk(__u8 *serial, struct imsm_super *mpb, int *idx)
{
        int i;

        for (i = 0; i < mpb->num_disks; i++) {
                struct imsm_disk *disk = __get_imsm_disk(mpb, i);

                if (serialcmp(disk->serial, serial) == 0) {
                        if (idx)
                                *idx = i;
                        return disk;
                }
        }

        return NULL;
}

static int
load_imsm_disk(int fd, struct intel_super *super, char *devname, int keep_fd)
{
        struct imsm_disk *disk;
        struct dl *dl;
        struct stat stb;
        int rv;
        char name[40];
        __u8 serial[MAX_RAID_SERIAL_LEN];

        rv = imsm_read_serial(fd, devname, serial);

        if (rv != 0)
                return 2;

        dl = calloc(1, sizeof(*dl));
        if (!dl) {
                if (devname)
                        fprintf(stderr,
                                Name ": failed to allocate disk buffer for %s\n",
                                devname);
                return 2;
        }

        fstat(fd, &stb);
        dl->major = major(stb.st_rdev);
        dl->minor = minor(stb.st_rdev);
        dl->next = super->disks;
        dl->fd = keep_fd ? fd : -1;
        assert(super->disks == NULL);
        super->disks = dl;
        serialcpy(dl->serial, serial);
        dl->index = -2;
        dl->e = NULL;
        fd2devname(fd, name);
        if (devname)
                dl->devname = strdup(devname);
        else
                dl->devname = strdup(name);

        /* look up this disk's index in the current anchor */
        disk = __serial_to_disk(dl->serial, super->anchor, &dl->index);
        if (disk) {
                dl->disk = *disk;
                /* only set index on disks that are a member of a
                 * populated contianer, i.e. one with raid_devs
                 */
                if (is_failed(&dl->disk))
                        dl->index = -2;
                else if (is_spare(&dl->disk))
                        dl->index = -1;
        }

        return 0;
}

#ifndef MDASSEMBLE
/* When migrating map0 contains the 'destination' state while map1
 * contains the current state.  When not migrating map0 contains the
 * current state.  This routine assumes that map[0].map_state is set to
 * the current array state before being called.
 *
 * Migration is indicated by one of the following states
 * 1/ Idle (migr_state=0 map0state=normal||unitialized||degraded||failed)
 * 2/ Initialize (migr_state=1 migr_type=MIGR_INIT map0state=normal
 *    map1state=unitialized)
 * 3/ Repair (Resync) (migr_state=1 migr_type=MIGR_REPAIR  map0state=normal
 *    map1state=normal)
 * 4/ Rebuild (migr_state=1 migr_type=MIGR_REBUILD map0state=normal
 *    map1state=degraded)
 * 5/ Migration (mig_state=1 migr_type=MIGR_GEN_MIGR map0state=normal
 *    map1state=normal)
 */
static void migrate(struct imsm_dev *dev, struct intel_super *super,
                    __u8 to_state, int migr_type)
{
        struct imsm_map *dest;
        struct imsm_map *src = get_imsm_map(dev, 0);

        dev->vol.migr_state = 1;
        set_migr_type(dev, migr_type);
        dev->vol.curr_migr_unit = 0;
        dest = get_imsm_map(dev, 1);

        /* duplicate and then set the target end state in map[0] */
        memcpy(dest, src, sizeof_imsm_map(src));
        if ((migr_type == MIGR_REBUILD) ||
            (migr_type ==  MIGR_GEN_MIGR)) {
                __u32 ord;
                int i;

                for (i = 0; i < src->num_members; i++) {
                        ord = __le32_to_cpu(src->disk_ord_tbl[i]);
                        set_imsm_ord_tbl_ent(src, i, ord_to_idx(ord));
                }
        }

        if (migr_type == MIGR_GEN_MIGR)
                /* Clear migration record */
                memset(super->migr_rec, 0, sizeof(struct migr_record));

        src->map_state = to_state;
}

static void end_migration(struct imsm_dev *dev, __u8 map_state)
{
        struct imsm_map *map = get_imsm_map(dev, 0);
        struct imsm_map *prev = get_imsm_map(dev, dev->vol.migr_state);
        int i, j;

        /* merge any IMSM_ORD_REBUILD bits that were not successfully
         * completed in the last migration.
         *
         * FIXME add support for raid-level-migration
         */
        for (i = 0; i < prev->num_members; i++)
                for (j = 0; j < map->num_members; j++)
                        /* during online capacity expansion
                         * disks position can be changed if takeover is used
                         */
                        if (ord_to_idx(map->disk_ord_tbl[j]) ==
                            ord_to_idx(prev->disk_ord_tbl[i])) {
                                map->disk_ord_tbl[j] |= prev->disk_ord_tbl[i];
                                break;
                        }

        dev->vol.migr_state = 0;
        dev->vol.migr_type = 0;
        dev->vol.curr_migr_unit = 0;
        map->map_state = map_state;
}
#endif

static int parse_raid_devices(struct intel_super *super)
{
        int i;
        struct imsm_dev *dev_new;
        size_t len, len_migr;
        size_t max_len = 0;
        size_t space_needed = 0;
        struct imsm_super *mpb = super->anchor;

        for (i = 0; i < super->anchor->num_raid_devs; i++) {
                struct imsm_dev *dev_iter = __get_imsm_dev(super->anchor, i);
                struct intel_dev *dv;

                len = sizeof_imsm_dev(dev_iter, 0);
                len_migr = sizeof_imsm_dev(dev_iter, 1);
                if (len_migr > len)
                        space_needed += len_migr - len;
                
                dv = malloc(sizeof(*dv));
                if (!dv)
                        return 1;
                if (max_len < len_migr)
                        max_len = len_migr;
                if (max_len > len_migr)
                        space_needed += max_len - len_migr;
                dev_new = malloc(max_len);
                if (!dev_new) {
                        free(dv);
                        return 1;
                }
                imsm_copy_dev(dev_new, dev_iter);
                dv->dev = dev_new;
                dv->index = i;
                dv->next = super->devlist;
                super->devlist = dv;
        }

        /* ensure that super->buf is large enough when all raid devices
         * are migrating
         */
        if (__le32_to_cpu(mpb->mpb_size) + space_needed > super->len) {
                void *buf;

                len = ROUND_UP(__le32_to_cpu(mpb->mpb_size) + space_needed, 512);
                if (posix_memalign(&buf, 512, len) != 0)
                        return 1;

                memcpy(buf, super->buf, super->len);
                memset(buf + super->len, 0, len - super->len);
                free(super->buf);
                super->buf = buf;
                super->len = len;
        }
                
        return 0;
}

/* retrieve a pointer to the bbm log which starts after all raid devices */
struct bbm_log *__get_imsm_bbm_log(struct imsm_super *mpb)
{
        void *ptr = NULL;

        if (__le32_to_cpu(mpb->bbm_log_size)) {
                ptr = mpb;
                ptr += mpb->mpb_size - __le32_to_cpu(mpb->bbm_log_size);
        } 

        return ptr;
}

/*******************************************************************************
 * Function:    check_mpb_migr_compatibility
 * Description: Function checks for unsupported migration features:
 *              - migration optimization area (pba_of_lba0)
 *              - descending reshape (ascending_migr)
 * Parameters:
 *      super   : imsm metadata information
 * Returns:
 *       0 : migration is compatible
 *      -1 : migration is not compatible
 ******************************************************************************/
int check_mpb_migr_compatibility(struct intel_super *super)
{
        struct imsm_map *map0, *map1;
        struct migr_record *migr_rec = super->migr_rec;
        int i;

        for (i = 0; i < super->anchor->num_raid_devs; i++) {
                struct imsm_dev *dev_iter = __get_imsm_dev(super->anchor, i);

                if (dev_iter &&
                    dev_iter->vol.migr_state == 1 &&
                    dev_iter->vol.migr_type == MIGR_GEN_MIGR) {
                        /* This device is migrating */
                        map0 = get_imsm_map(dev_iter, 0);
                        map1 = get_imsm_map(dev_iter, 1);
                        if (map0->pba_of_lba0 != map1->pba_of_lba0)
                                /* migration optimization area was used */
                                return -1;
                        if (migr_rec->ascending_migr == 0
                                && migr_rec->dest_depth_per_unit > 0)
                                /* descending reshape not supported yet */
                                return -1;
                }
        }
        return 0;
}

static void __free_imsm(struct intel_super *super, int free_disks);

/* load_imsm_mpb - read matrix metadata
 * allocates super->mpb to be freed by free_imsm
 */
static int load_imsm_mpb(int fd, struct intel_super *super, char *devname)
{
        unsigned long long dsize;
        unsigned long long sectors;
        struct stat;
        struct imsm_super *anchor;
        __u32 check_sum;

        get_dev_size(fd, NULL, &dsize);
        if (dsize < 1024) {
                if (devname)
                        fprintf(stderr,
                                Name ": %s: device to small for imsm\n",
                                devname);
                return 1;
        }

        if (lseek64(fd, dsize - (512 * 2), SEEK_SET) < 0) {
                if (devname)
                        fprintf(stderr,
                                Name ": Cannot seek to anchor block on %s: %s\n",
                                devname, strerror(errno));
                return 1;
        }

        if (posix_memalign((void**)&anchor, 512, 512) != 0) {
                if (devname)
                        fprintf(stderr,
                                Name ": Failed to allocate imsm anchor buffer"
                                " on %s\n", devname);
                return 1;
        }
        if (read(fd, anchor, 512) != 512) {
                if (devname)
                        fprintf(stderr,
                                Name ": Cannot read anchor block on %s: %s\n",
                                devname, strerror(errno));
                free(anchor);
                return 1;
        }

        if (strncmp((char *) anchor->sig, MPB_SIGNATURE, MPB_SIG_LEN) != 0) {
                if (devname)
                        fprintf(stderr,
                                Name ": no IMSM anchor on %s\n", devname);
                free(anchor);
                return 2;
        }

        __free_imsm(super, 0);
        /*  reload capability and hba */

        /* capability and hba must be updated with new super allocation */
        find_intel_hba_capability(fd, super, devname);
        super->len = ROUND_UP(anchor->mpb_size, 512);
        if (posix_memalign(&super->buf, 512, super->len) != 0) {
                if (devname)
                        fprintf(stderr,
                                Name ": unable to allocate %zu byte mpb buffer\n",
                                super->len);
                free(anchor);
                return 2;
        }
        memcpy(super->buf, anchor, 512);

        sectors = mpb_sectors(anchor) - 1;
        free(anchor);

        if (posix_memalign(&super->migr_rec_buf, 512, 512) != 0) {
                fprintf(stderr, Name
                        ": %s could not allocate migr_rec buffer\n", __func__);
                free(super->buf);
                return 2;
        }

        if (!sectors) {
                check_sum = __gen_imsm_checksum(super->anchor);
                if (check_sum != __le32_to_cpu(super->anchor->check_sum)) {
                        if (devname)
                                fprintf(stderr,
                                        Name ": IMSM checksum %x != %x on %s\n",
                                        check_sum,
                                        __le32_to_cpu(super->anchor->check_sum),
                                        devname);
                        return 2;
                }

                return 0;
        }

        /* read the extended mpb */
        if (lseek64(fd, dsize - (512 * (2 + sectors)), SEEK_SET) < 0) {
                if (devname)
                        fprintf(stderr,
                                Name ": Cannot seek to extended mpb on %s: %s\n",
                                devname, strerror(errno));
                return 1;
        }

        if ((unsigned)read(fd, super->buf + 512, super->len - 512) != super->len - 512) {
                if (devname)
                        fprintf(stderr,
                                Name ": Cannot read extended mpb on %s: %s\n",
                                devname, strerror(errno));
                return 2;
        }

        check_sum = __gen_imsm_checksum(super->anchor);
        if (check_sum != __le32_to_cpu(super->anchor->check_sum)) {
                if (devname)
                        fprintf(stderr,
                                Name ": IMSM checksum %x != %x on %s\n",
                                check_sum, __le32_to_cpu(super->anchor->check_sum),
                                devname);
                return 3;
        }

        /* FIXME the BBM log is disk specific so we cannot use this global
         * buffer for all disks.  Ok for now since we only look at the global
         * bbm_log_size parameter to gate assembly
         */
        super->bbm_log = __get_imsm_bbm_log(super->anchor);

        return 0;
}

static int read_imsm_migr_rec(int fd, struct intel_super *super);

static int
load_and_parse_mpb(int fd, struct intel_super *super, char *devname, int keep_fd)
{
        int err;

        err = load_imsm_mpb(fd, super, devname);
        if (err)
                return err;
        err = load_imsm_disk(fd, super, devname, keep_fd);
        if (err)
                return err;
        err = parse_raid_devices(super);

        return err;
}

static void __free_imsm_disk(struct dl *d)
{
        if (d->fd >= 0)
                close(d->fd);
        if (d->devname)
                free(d->devname);
        if (d->e)
                free(d->e);
        free(d);

}

static void free_imsm_disks(struct intel_super *super)
{
        struct dl *d;

        while (super->disks) {
                d = super->disks;
                super->disks = d->next;
                __free_imsm_disk(d);
        }
        while (super->disk_mgmt_list) {
                d = super->disk_mgmt_list;
                super->disk_mgmt_list = d->next;
                __free_imsm_disk(d);
        }
        while (super->missing) {
                d = super->missing;
                super->missing = d->next;
                __free_imsm_disk(d);
        }

}

/* free all the pieces hanging off of a super pointer */
static void __free_imsm(struct intel_super *super, int free_disks)
{
        struct intel_hba *elem, *next;

        if (super->buf) {
                free(super->buf);
                super->buf = NULL;
        }
        /* unlink capability description */
        super->orom = NULL;
        if (super->migr_rec_buf) {
                free(super->migr_rec_buf);
                super->migr_rec_buf = NULL;
        }
        if (free_disks)
                free_imsm_disks(super);
        free_devlist(super);
        elem = super->hba;
        while (elem) {
                if (elem->path)
                        free((void *)elem->path);
                next = elem->next;
                free(elem);
                elem = next;
        }
        super->hba = NULL;
}

static void free_imsm(struct intel_super *super)
{
        __free_imsm(super, 1);
        free(super);
}

static void free_super_imsm(struct supertype *st)
{
        struct intel_super *super = st->sb;

        if (!super)
                return;

        free_imsm(super);
        st->sb = NULL;
}

static struct intel_super *alloc_super(void)
{
        struct intel_super *super = malloc(sizeof(*super));

        if (super) {
                memset(super, 0, sizeof(*super));
                super->current_vol = -1;
                super->create_offset = ~((__u32 ) 0);
        }
        return super;
}

/*
 * find and allocate hba and OROM/EFI based on valid fd of RAID component device
 */
static int find_intel_hba_capability(int fd, struct intel_super *super, char *devname)
{
        struct sys_dev *hba_name;
        int rv = 0;

        if ((fd < 0) || check_env("IMSM_NO_PLATFORM")) {
                super->orom = NULL;
                super->hba = NULL;
                return 0;
        }
        hba_name = find_disk_attached_hba(fd, NULL);
        if (!hba_name) {
                if (devname)
                        fprintf(stderr,
                                Name ": %s is not attached to Intel(R) RAID controller.\n",
                                devname);
                return 1;
        }
        rv = attach_hba_to_super(super, hba_name);
        if (rv == 2) {
                if (devname) {
                        struct intel_hba *hba = super->hba;

                        fprintf(stderr, Name ": %s is attached to Intel(R) %s RAID "
                                "controller (%s),\n"
                                "    but the container is assigned to Intel(R) "
                                "%s RAID controller (",
                                devname,
                                hba_name->path,
                                hba_name->pci_id ? : "Err!",
                                get_sys_dev_type(hba_name->type));

                        while (hba) {
                                fprintf(stderr, "%s", hba->pci_id ? : "Err!");
                                if (hba->next)
                                        fprintf(stderr, ", ");
                                hba = hba->next;
                        }

                        fprintf(stderr, ").\n"
                                "    Mixing devices attached to different controllers "
                                "is not allowed.\n");
                }
                free_sys_dev(&hba_name);
                return 2;
        }
        super->orom = find_imsm_capability(hba_name->type);
        free_sys_dev(&hba_name);
        if (!super->orom)
                return 3;
        return 0;
}

#ifndef MDASSEMBLE
/* find_missing - helper routine for load_super_imsm_all that identifies
 * disks that have disappeared from the system.  This routine relies on
 * the mpb being uptodate, which it is at load time.
 */
static int find_missing(struct intel_super *super)
{
        int i;
        struct imsm_super *mpb = super->anchor;
        struct dl *dl;
        struct imsm_disk *disk;

        for (i = 0; i < mpb->num_disks; i++) {
                disk = __get_imsm_disk(mpb, i);
                dl = serial_to_dl(disk->serial, super);
                if (dl)
                        continue;

                dl = malloc(sizeof(*dl));
                if (!dl)
                        return 1;
                dl->major = 0;
                dl->minor = 0;
                dl->fd = -1;
                dl->devname = strdup("missing");
                dl->index = i;
                serialcpy(dl->serial, disk->serial);
                dl->disk = *disk;
                dl->e = NULL;
                dl->next = super->missing;
                super->missing = dl;
        }

        return 0;
}

static struct intel_disk *disk_list_get(__u8 *serial, struct intel_disk *disk_list)
{
        struct intel_disk *idisk = disk_list;

        while (idisk) {
                if (serialcmp(idisk->disk.serial, serial) == 0)
                        break;
                idisk = idisk->next;
        }

        return idisk;
}

static int __prep_thunderdome(struct intel_super **table, int tbl_size,
                              struct intel_super *super,
                              struct intel_disk **disk_list)
{
        struct imsm_disk *d = &super->disks->disk;
        struct imsm_super *mpb = super->anchor;
        int i, j;

        for (i = 0; i < tbl_size; i++) {
                struct imsm_super *tbl_mpb = table[i]->anchor;
                struct imsm_disk *tbl_d = &table[i]->disks->disk;

                if (tbl_mpb->family_num == mpb->family_num) {
                        if (tbl_mpb->check_sum == mpb->check_sum) {
                                dprintf("%s: mpb from %d:%d matches %d:%d\n",
                                        __func__, super->disks->major,
                                        super->disks->minor,
                                        table[i]->disks->major,
                                        table[i]->disks->minor);
                                break;
                        }

                        if (((is_configured(d) && !is_configured(tbl_d)) ||
                             is_configured(d) == is_configured(tbl_d)) &&
                            tbl_mpb->generation_num < mpb->generation_num) {
                                /* current version of the mpb is a
                                 * better candidate than the one in
                                 * super_table, but copy over "cross
                                 * generational" status
                                 */
                                struct intel_disk *idisk;

                                dprintf("%s: mpb from %d:%d replaces %d:%d\n",
                                        __func__, super->disks->major,
                                        super->disks->minor,
                                        table[i]->disks->major,
                                        table[i]->disks->minor);

                                idisk = disk_list_get(tbl_d->serial, *disk_list);
                                if (idisk && is_failed(&idisk->disk))
                                        tbl_d->status |= FAILED_DISK;
                                break;
                        } else {
                                struct intel_disk *idisk;
                                struct imsm_disk *disk;

                                /* tbl_mpb is more up to date, but copy
                                 * over cross generational status before
                                 * returning
                                 */
                                disk = __serial_to_disk(d->serial, mpb, NULL);
                                if (disk && is_failed(disk))
                                        d->status |= FAILED_DISK;

                                idisk = disk_list_get(d->serial, *disk_list);
                                if (idisk) {
                                        idisk->owner = i;
                                        if (disk && is_configured(disk))
                                                idisk->disk.status |= CONFIGURED_DISK;
                                }

                                dprintf("%s: mpb from %d:%d prefer %d:%d\n",
                                        __func__, super->disks->major,
                                        super->disks->minor,
                                        table[i]->disks->major,
                                        table[i]->disks->minor);

                                return tbl_size;
                        }
                }
        }

        if (i >= tbl_size)
                table[tbl_size++] = super;
        else
                table[i] = super;

        /* update/extend the merged list of imsm_disk records */
        for (j = 0; j < mpb->num_disks; j++) {
                struct imsm_disk *disk = __get_imsm_disk(mpb, j);
                struct intel_disk *idisk;

                idisk = disk_list_get(disk->serial, *disk_list);
                if (idisk) {
                        idisk->disk.status |= disk->status;
                        if (is_configured(&idisk->disk) ||
                            is_failed(&idisk->disk))
                                idisk->disk.status &= ~(SPARE_DISK);
                } else {
                        idisk = calloc(1, sizeof(*idisk));
                        if (!idisk)
                                return -1;
                        idisk->owner = IMSM_UNKNOWN_OWNER;
                        idisk->disk = *disk;
                        idisk->next = *disk_list;
                        *disk_list = idisk;
                }

                if (serialcmp(idisk->disk.serial, d->serial) == 0)
                        idisk->owner = i;
        }

        return tbl_size;
}

static struct intel_super *
validate_members(struct intel_super *super, struct intel_disk *disk_list,
                 const int owner)
{
        struct imsm_super *mpb = super->anchor;
        int ok_count = 0;
        int i;

        for (i = 0; i < mpb->num_disks; i++) {
                struct imsm_disk *disk = __get_imsm_disk(mpb, i);
                struct intel_disk *idisk;

                idisk = disk_list_get(disk->serial, disk_list);
                if (idisk) {
                        if (idisk->owner == owner ||
                            idisk->owner == IMSM_UNKNOWN_OWNER)
                                ok_count++;
                        else
                                dprintf("%s: '%.16s' owner %d != %d\n",
                                        __func__, disk->serial, idisk->owner,
                                        owner);
                } else {
                        dprintf("%s: unknown disk %x [%d]: %.16s\n",
                                __func__, __le32_to_cpu(mpb->family_num), i,
                                disk->serial);
                        break;
                }
        }

        if (ok_count == mpb->num_disks)
                return super;
        return NULL;
}

static void show_conflicts(__u32 family_num, struct intel_super *super_list)
{
        struct intel_super *s;

        for (s = super_list; s; s = s->next) {
                if (family_num != s->anchor->family_num)
                        continue;
                fprintf(stderr, "Conflict, offlining family %#x on '%s'\n",
                        __le32_to_cpu(family_num), s->disks->devname);
        }
}

static struct intel_super *
imsm_thunderdome(struct intel_super **super_list, int len)
{
        struct intel_super *super_table[len];
        struct intel_disk *disk_list = NULL;
        struct intel_super *champion, *spare;
        struct intel_super *s, **del;
        int tbl_size = 0;
        int conflict;
        int i;

        memset(super_table, 0, sizeof(super_table));
        for (s = *super_list; s; s = s->next)
                tbl_size = __prep_thunderdome(super_table, tbl_size, s, &disk_list);

        for (i = 0; i < tbl_size; i++) {
                struct imsm_disk *d;
                struct intel_disk *idisk;
                struct imsm_super *mpb = super_table[i]->anchor;

                s = super_table[i];
                d = &s->disks->disk;

                /* 'd' must appear in merged disk list for its
                 * configuration to be valid
                 */
                idisk = disk_list_get(d->serial, disk_list);
                if (idisk && idisk->owner == i)
                        s = validate_members(s, disk_list, i);
                else
                        s = NULL;

                if (!s)
                        dprintf("%s: marking family: %#x from %d:%d offline\n",
                                __func__, mpb->family_num,
                                super_table[i]->disks->major,
                                super_table[i]->disks->minor);
                super_table[i] = s;
        }

        /* This is where the mdadm implementation differs from the Windows
         * driver which has no strict concept of a container.  We can only
         * assemble one family from a container, so when returning a prodigal
         * array member to this system the code will not be able to disambiguate
         * the container contents that should be assembled ("foreign" versus
         * "local").  It requires user intervention to set the orig_family_num
         * to a new value to establish a new container.  The Windows driver in
         * this situation fixes up the volume name in place and manages the
         * foreign array as an independent entity.
         */
        s = NULL;
        spare = NULL;
        conflict = 0;
        for (i = 0; i < tbl_size; i++) {
                struct intel_super *tbl_ent = super_table[i];
                int is_spare = 0;

                if (!tbl_ent)
                        continue;

                if (tbl_ent->anchor->num_raid_devs == 0) {
                        spare = tbl_ent;
                        is_spare = 1;
                }

                if (s && !is_spare) {
                        show_conflicts(tbl_ent->anchor->family_num, *super_list);
                        conflict++;
                } else if (!s && !is_spare)
                        s = tbl_ent;
        }

        if (!s)
                s = spare;
        if (!s) {
                champion = NULL;
                goto out;
        }
        champion = s;

        if (conflict)
                fprintf(stderr, "Chose family %#x on '%s', "
                        "assemble conflicts to new container with '--update=uuid'\n",
                        __le32_to_cpu(s->anchor->family_num), s->disks->devname);

        /* collect all dl's onto 'champion', and update them to
         * champion's version of the status
         */
        for (s = *super_list; s; s = s->next) {
                struct imsm_super *mpb = champion->anchor;
                struct dl *dl = s->disks;

                if (s == champion)
                        continue;

                for (i = 0; i < mpb->num_disks; i++) {
                        struct imsm_disk *disk;

                        disk = __serial_to_disk(dl->serial, mpb, &dl->index);
                        if (disk) {
                                dl->disk = *disk;
                                /* only set index on disks that are a member of
                                 * a populated contianer, i.e. one with
                                 * raid_devs
                                 */
                                if (is_failed(&dl->disk))
                                        dl->index = -2;
                                else if (is_spare(&dl->disk))
                                        dl->index = -1;
                                break;
                        }
                }

                if (i >= mpb->num_disks) {
                        struct intel_disk *idisk;

                        idisk = disk_list_get(dl->serial, disk_list);
                        if (idisk && is_spare(&idisk->disk) &&
                            !is_failed(&idisk->disk) && !is_configured(&idisk->disk))
                                dl->index = -1;
                        else {
                                dl->index = -2;
                                continue;
                        }
                }

                dl->next = champion->disks;
                champion->disks = dl;
                s->disks = NULL;
        }

        /* delete 'champion' from super_list */
        for (del = super_list; *del; ) {
                if (*del == champion) {
                        *del = (*del)->next;
                        break;
                } else
                        del = &(*del)->next;
        }
        champion->next = NULL;

 out:
        while (disk_list) {
                struct intel_disk *idisk = disk_list;

                disk_list = disk_list->next;
                free(idisk);
        }

        return champion;
}

static int load_super_imsm_all(struct supertype *st, int fd, void **sbp,
                               char *devname)
{
        struct mdinfo *sra;
        struct intel_super *super_list = NULL;
        struct intel_super *super = NULL;
        int devnum = fd2devnum(fd);
        struct mdinfo *sd;
        int retry;
        int err = 0;
        int i;

        /* check if 'fd' an opened container */
        sra = sysfs_read(fd, 0, GET_LEVEL|GET_VERSION|GET_DEVS|GET_STATE);
        if (!sra)
                return 1;

        if (sra->array.major_version != -1 ||
            sra->array.minor_version != -2 ||
            strcmp(sra->text_version, "imsm") != 0) {
                err = 1;
                goto error;
        }
        /* load all mpbs */
        for (sd = sra->devs, i = 0; sd; sd = sd->next, i++) {
                struct intel_super *s = alloc_super();
                char nm[32];
                int dfd;
                int rv;

                err = 1;
                if (!s)
                        goto error;
                s->next = super_list;
                super_list = s;

                err = 2;
                sprintf(nm, "%d:%d", sd->disk.major, sd->disk.minor);
                dfd = dev_open(nm, O_RDWR);
                if (dfd < 0)
                        goto error;

                rv = find_intel_hba_capability(dfd, s, devname);
                /* no orom/efi or non-intel hba of the disk */
                if (rv != 0)
                        goto error;

                err = load_and_parse_mpb(dfd, s, NULL, 1);

                /* retry the load if we might have raced against mdmon */
                if (err == 3 && mdmon_running(devnum))
                        for (retry = 0; retry < 3; retry++) {
                                usleep(3000);
                                err = load_and_parse_mpb(dfd, s, NULL, 1);
                                if (err != 3)
                                        break;
                        }
                if (err)
                        goto error;
        }

        /* all mpbs enter, maybe one leaves */
        super = imsm_thunderdome(&super_list, i);
        if (!super) {
                err = 1;
                goto error;
        }

        if (find_missing(super) != 0) {
                free_imsm(super);
                err = 2;
                goto error;
        }

        /* load migration record */
        err = load_imsm_migr_rec(super, NULL);
        if (err) {
                err = 4;
                goto error;
        }

        /* Check migration compatibility */
        if (check_mpb_migr_compatibility(super) != 0) {
                fprintf(stderr, Name ": Unsupported migration detected");
                if (devname)
                        fprintf(stderr, " on %s\n", devname);
                else
                        fprintf(stderr, " (IMSM).\n");

                err = 5;
                goto error;
        }

        err = 0;

 error:
        while (super_list) {
                struct intel_super *s = super_list;

                super_list = super_list->next;
                free_imsm(s);
        }
        sysfs_free(sra);

        if (err)
                return err;

        *sbp = super;
        st->container_dev = devnum;
        if (err == 0 && st->ss == NULL) {
                st->ss = &super_imsm;
                st->minor_version = 0;
                st->max_devs = IMSM_MAX_DEVICES;
        }
        return 0;
}

static int load_container_imsm(struct supertype *st, int fd, char *devname)
{
        return load_super_imsm_all(st, fd, &st->sb, devname);
}
#endif

static int load_super_imsm(struct supertype *st, int fd, char *devname)
{
        struct intel_super *super;
        int rv;

        if (test_partition(fd))
                /* IMSM not allowed on partitions */
                return 1;

        free_super_imsm(st);

        super = alloc_super();
        if (!super) {
                fprintf(stderr,
                        Name ": malloc of %zu failed.\n",
                        sizeof(*super));
                return 1;
        }
        /* Load hba and capabilities if they exist.
         * But do not preclude loading metadata in case capabilities or hba are
         * non-compliant and ignore_hw_compat is set.
         */
        rv = find_intel_hba_capability(fd, super, devname);
        /* no orom/efi or non-intel hba of the disk */
        if ((rv != 0) && (st->ignore_hw_compat == 0)) {
                if (devname)
                        fprintf(stderr,
                                Name ": No OROM/EFI properties for %s\n", devname);
                free_imsm(super);
                return 2;
        }
        rv = load_and_parse_mpb(fd, super, devname, 0);

        if (rv) {
                if (devname)
                        fprintf(stderr,
                                Name ": Failed to load all information "
                                "sections on %s\n", devname);
                free_imsm(super);
                return rv;
        }

        st->sb = super;
        if (st->ss == NULL) {
                st->ss = &super_imsm;
                st->minor_version = 0;
                st->max_devs = IMSM_MAX_DEVICES;
        }

        /* load migration record */
        load_imsm_migr_rec(super, NULL);

        /* Check for unsupported migration features */
        if (check_mpb_migr_compatibility(super) != 0) {
                fprintf(stderr, Name ": Unsupported migration detected");
                if (devname)
                        fprintf(stderr, " on %s\n", devname);
                else
                        fprintf(stderr, " (IMSM).\n");
                return 3;
        }

        return 0;
}

static __u16 info_to_blocks_per_strip(mdu_array_info_t *info)
{
        if (info->level == 1)
                return 128;
        return info->chunk_size >> 9;
}

static __u32 info_to_num_data_stripes(mdu_array_info_t *info, int num_domains)
{
        __u32 num_stripes;

        num_stripes = (info->size * 2) / info_to_blocks_per_strip(info);
        num_stripes /= num_domains;

        return num_stripes;
}

static __u32 info_to_blocks_per_member(mdu_array_info_t *info)
{
        if (info->level == 1)
                return info->size * 2;
        else
                return (info->size * 2) & ~(info_to_blocks_per_strip(info) - 1);
}

static void imsm_update_version_info(struct intel_super *super)
{
        /* update the version and attributes */
        struct imsm_super *mpb = super->anchor;
        char *version;
        struct imsm_dev *dev;
        struct imsm_map *map;
        int i;

        for (i = 0; i < mpb->num_raid_devs; i++) {
                dev = get_imsm_dev(super, i);
                map = get_imsm_map(dev, 0);
                if (__le32_to_cpu(dev->size_high) > 0)
                        mpb->attributes |= MPB_ATTRIB_2TB;

                /* FIXME detect when an array spans a port multiplier */
                #if 0
                mpb->attributes |= MPB_ATTRIB_PM;
                #endif

                if (mpb->num_raid_devs > 1 ||
                    mpb->attributes != MPB_ATTRIB_CHECKSUM_VERIFY) {
                        version = MPB_VERSION_ATTRIBS;
                        switch (get_imsm_raid_level(map)) {
                        case 0: mpb->attributes |= MPB_ATTRIB_RAID0; break;
                        case 1: mpb->attributes |= MPB_ATTRIB_RAID1; break;
                        case 10: mpb->attributes |= MPB_ATTRIB_RAID10; break;
                        case 5: mpb->attributes |= MPB_ATTRIB_RAID5; break;
                        }
                } else {
                        if (map->num_members >= 5)
                                version = MPB_VERSION_5OR6_DISK_ARRAY;
                        else if (dev->status == DEV_CLONE_N_GO)
                                version = MPB_VERSION_CNG;
                        else if (get_imsm_raid_level(map) == 5)
                                version = MPB_VERSION_RAID5;
                        else if (map->num_members >= 3)
                                version = MPB_VERSION_3OR4_DISK_ARRAY;
                        else if (get_imsm_raid_level(map) == 1)
                                version = MPB_VERSION_RAID1;
                        else
                                version = MPB_VERSION_RAID0;
                }
                strcpy(((char *) mpb->sig) + strlen(MPB_SIGNATURE), version);
        }
}

static int check_name(struct intel_super *super, char *name, int quiet)
{
        struct imsm_super *mpb = super->anchor;
        char *reason = NULL;
        int i;

        if (strlen(name) > MAX_RAID_SERIAL_LEN)
                reason = "must be 16 characters or less";

        for (i = 0; i < mpb->num_raid_devs; i++) {
                struct imsm_dev *dev = get_imsm_dev(super, i);

                if (strncmp((char *) dev->volume, name, MAX_RAID_SERIAL_LEN) == 0) {
                        reason = "already exists";
                        break;
                }
        }

        if (reason && !quiet)
                fprintf(stderr, Name ": imsm volume name %s\n", reason);

        return !reason;
}

static int init_super_imsm_volume(struct supertype *st, mdu_array_info_t *info,
                                  unsigned long long size, char *name,
                                  char *homehost, int *uuid)
{
        /* We are creating a volume inside a pre-existing container.
         * so st->sb is already set.
         */
        struct intel_super *super = st->sb;
        struct imsm_super *mpb = super->anchor;
        struct intel_dev *dv;
        struct imsm_dev *dev;
        struct imsm_vol *vol;
        struct imsm_map *map;
        int idx = mpb->num_raid_devs;
        int i;
        unsigned long long array_blocks;
        size_t size_old, size_new;
        __u32 num_data_stripes;

        if (super->orom && mpb->num_raid_devs >= super->orom->vpa) {
                fprintf(stderr, Name": This imsm-container already has the "
                        "maximum of %d volumes\n", super->orom->vpa);
                return 0;
        }

        /* ensure the mpb is large enough for the new data */
        size_old = __le32_to_cpu(mpb->mpb_size);
        size_new = disks_to_mpb_size(info->nr_disks);
        if (size_new > size_old) {
                void *mpb_new;
                size_t size_round = ROUND_UP(size_new, 512);

                if (posix_memalign(&mpb_new, 512, size_round) != 0) {
                        fprintf(stderr, Name": could not allocate new mpb\n");
                        return 0;
                }
                if (posix_memalign(&super->migr_rec_buf, 512, 512) != 0) {
                        fprintf(stderr, Name
                                ": %s could not allocate migr_rec buffer\n",
                                __func__);
                        free(super->buf);
                        free(super);
                        return 0;
                }
                memcpy(mpb_new, mpb, size_old);
                free(mpb);
                mpb = mpb_new;
                super->anchor = mpb_new;
                mpb->mpb_size = __cpu_to_le32(size_new);
                memset(mpb_new + size_old, 0, size_round - size_old);
        }
        super->current_vol = idx;
        /* when creating the first raid device in this container set num_disks
         * to zero, i.e. delete this spare and add raid member devices in
         * add_to_super_imsm_volume()
         */
        if (super->current_vol == 0)
                mpb->num_disks = 0;

        if (!check_name(super, name, 0))
                return 0;
        dv = malloc(sizeof(*dv));
        if (!dv) {
                fprintf(stderr, Name ": failed to allocate device list entry\n");
                return 0;
        }
        dev = calloc(1, sizeof(*dev) + sizeof(__u32) * (info->raid_disks - 1));
        if (!dev) {
                free(dv);
                fprintf(stderr, Name": could not allocate raid device\n");
                return 0;
        }

        strncpy((char *) dev->volume, name, MAX_RAID_SERIAL_LEN);
        if (info->level == 1)
                array_blocks = info_to_blocks_per_member(info);
        else
                array_blocks = calc_array_size(info->level, info->raid_disks,
                                               info->layout, info->chunk_size,
                                               info->size*2);
        /* round array size down to closest MB */
        array_blocks = (array_blocks >> SECT_PER_MB_SHIFT) << SECT_PER_MB_SHIFT;

        dev->size_low = __cpu_to_le32((__u32) array_blocks);
        dev->size_high = __cpu_to_le32((__u32) (array_blocks >> 32));
        dev->status = (DEV_READ_COALESCING | DEV_WRITE_COALESCING);
        vol = &dev->vol;
        vol->migr_state = 0;
        set_migr_type(dev, MIGR_INIT);
        vol->dirty = 0;
        vol->curr_migr_unit = 0;
        map = get_imsm_map(dev, 0);
        map->pba_of_lba0 = __cpu_to_le32(super->create_offset);
        map->blocks_per_member = __cpu_to_le32(info_to_blocks_per_member(info));
        map->blocks_per_strip = __cpu_to_le16(info_to_blocks_per_strip(info));
        map->failed_disk_num = ~0;
        map->map_state = info->level ? IMSM_T_STATE_UNINITIALIZED :
                                       IMSM_T_STATE_NORMAL;
        map->ddf = 1;

        if (info->level == 1 && info->raid_disks > 2) {
                free(dev);
                free(dv);
                fprintf(stderr, Name": imsm does not support more than 2 disks"
                                "in a raid1 volume\n");
                return 0;
        }

        map->raid_level = info->level;
        if (info->level == 10) {
                map->raid_level = 1;
                map->num_domains = info->raid_disks / 2;
        } else if (info->level == 1)
                map->num_domains = info->raid_disks;
        else
                map->num_domains = 1;

        num_data_stripes = info_to_num_data_stripes(info, map->num_domains);
        map->num_data_stripes = __cpu_to_le32(num_data_stripes);

        map->num_members = info->raid_disks;
        for (i = 0; i < map->num_members; i++) {
                /* initialized in add_to_super */
                set_imsm_ord_tbl_ent(map, i, IMSM_ORD_REBUILD);
        }
        mpb->num_raid_devs++;

        dv->dev = dev;
        dv->index = super->current_vol;
        dv->next = super->devlist;
        super->devlist = dv;

        imsm_update_version_info(super);

        return 1;
}

static int init_super_imsm(struct supertype *st, mdu_array_info_t *info,
                           unsigned long long size, char *name,
                           char *homehost, int *uuid)
{
        /* This is primarily called by Create when creating a new array.
         * We will then get add_to_super called for each component, and then
         * write_init_super called to write it out to each device.
         * For IMSM, Create can create on fresh devices or on a pre-existing
         * array.
         * To create on a pre-existing array a different method will be called.
         * This one is just for fresh drives.
         */
        struct intel_super *super;
        struct imsm_super *mpb;
        size_t mpb_size;
        char *version;

        if (st->sb)
                return init_super_imsm_volume(st, info, size, name, homehost, uuid);

        if (info)
                mpb_size = disks_to_mpb_size(info->nr_disks);
        else
                mpb_size = 512;

        super = alloc_super();
        if (super && posix_memalign(&super->buf, 512, mpb_size) != 0) {
                free(super);
                super = NULL;
        }
        if (!super) {
                fprintf(stderr, Name
                        ": %s could not allocate superblock\n", __func__);
                return 0;
        }
        if (posix_memalign(&super->migr_rec_buf, 512, 512) != 0) {
                fprintf(stderr, Name
                        ": %s could not allocate migr_rec buffer\n", __func__);
                free(super->buf);
                free(super);
                return 0;
        }
        memset(super->buf, 0, mpb_size);
        mpb = super->buf;
        mpb->mpb_size = __cpu_to_le32(mpb_size);
        st->sb = super;

        if (info == NULL) {
                /* zeroing superblock */
                return 0;
        }

        mpb->attributes = MPB_ATTRIB_CHECKSUM_VERIFY;

        version = (char *) mpb->sig;
        strcpy(version, MPB_SIGNATURE);
        version += strlen(MPB_SIGNATURE);
        strcpy(version, MPB_VERSION_RAID0);

        return 1;
}

#ifndef MDASSEMBLE
static int add_to_super_imsm_volume(struct supertype *st, mdu_disk_info_t *dk,
                                     int fd, char *devname)
{
        struct intel_super *super = st->sb;
        struct imsm_super *mpb = super->anchor;
        struct dl *dl;
        struct imsm_dev *dev;
        struct imsm_map *map;
        int slot;

        dev = get_imsm_dev(super, super->current_vol);
        map = get_imsm_map(dev, 0);

        if (! (dk->state & (1<<MD_DISK_SYNC))) {
                fprintf(stderr, Name ": %s: Cannot add spare devices to IMSM volume\n",
                        devname);
                return 1;
        }

        if (fd == -1) {
                /* we're doing autolayout so grab the pre-marked (in
                 * validate_geometry) raid_disk
                 */
                for (dl = super->disks; dl; dl = dl->next)
                        if (dl->raiddisk == dk->raid_disk)
                                break;
        } else {
                for (dl = super->disks; dl ; dl = dl->next)
                        if (dl->major == dk->major &&
                            dl->minor == dk->minor)
                                break;
        }

        if (!dl) {
                fprintf(stderr, Name ": %s is not a member of the same container\n", devname);
                return 1;
        }

        /* add a pristine spare to the metadata */
        if (dl->index < 0) {
                dl->index = super->anchor->num_disks;
                super->anchor->num_disks++;
        }
        /* Check the device has not already been added */
        slot = get_imsm_disk_slot(map, dl->index);
        if (slot >= 0 &&
            (get_imsm_ord_tbl_ent(dev, slot, -1) & IMSM_ORD_REBUILD) == 0) {
                fprintf(stderr, Name ": %s has been included in this array twice\n",
                        devname);
                return 1;
        }
        set_imsm_ord_tbl_ent(map, dk->number, dl->index);
        dl->disk.status = CONFIGURED_DISK;

        /* if we are creating the first raid device update the family number */
        if (super->current_vol == 0) {
                __u32 sum;
                struct imsm_dev *_dev = __get_imsm_dev(mpb, 0);
                struct imsm_disk *_disk = __get_imsm_disk(mpb, dl->index);

                if (!_dev || !_disk) {
                        fprintf(stderr, Name ": BUG mpb setup error\n");
                        return 1;
                }
                *_dev = *dev;
                *_disk = dl->disk;
                sum = random32();
                sum += __gen_imsm_checksum(mpb);
                mpb->family_num = __cpu_to_le32(sum);
                mpb->orig_family_num = mpb->family_num;
        }

        return 0;
}


static int add_to_super_imsm(struct supertype *st, mdu_disk_info_t *dk,
                             int fd, char *devname)
{
        struct intel_super *super = st->sb;
        struct dl *dd;
        unsigned long long size;
        __u32 id;
        int rv;
        struct stat stb;

        /* If we are on an RAID enabled platform check that the disk is
         * attached to the raid controller.
         * We do not need to test disks attachment for container based additions,
         * they shall be already tested when container was created/assembled.
         */
        rv = find_intel_hba_capability(fd, super, devname);
        /* no orom/efi or non-intel hba of the disk */
        if (rv != 0) {
                dprintf("capability: %p fd: %d ret: %d\n",
                        super->orom, fd, rv);
                return 1;
        }

        if (super->current_vol >= 0)
                return add_to_super_imsm_volume(st, dk, fd, devname);

        fstat(fd, &stb);
        dd = malloc(sizeof(*dd));
        if (!dd) {
                fprintf(stderr,
                        Name ": malloc failed %s:%d.\n", __func__, __LINE__);
                return 1;
        }
        memset(dd, 0, sizeof(*dd));
        dd->major = major(stb.st_rdev);
        dd->minor = minor(stb.st_rdev);
        dd->index = -1;
        dd->devname = devname ? strdup(devname) : NULL;
        dd->fd = fd;
        dd->e = NULL;
        dd->action = DISK_ADD;
        rv = imsm_read_serial(fd, devname, dd->serial);
        if (rv) {
                fprintf(stderr,
                        Name ": failed to retrieve scsi serial, aborting\n");
                free(dd);
                abort();
        }

        get_dev_size(fd, NULL, &size);
        size /= 512;
        serialcpy(dd->disk.serial, dd->serial);
        dd->disk.total_blocks = __cpu_to_le32(size);
        dd->disk.status = SPARE_DISK;
        if (sysfs_disk_to_scsi_id(fd, &id) == 0)
                dd->disk.scsi_id = __cpu_to_le32(id);
        else
                dd->disk.scsi_id = __cpu_to_le32(0);

        if (st->update_tail) {
                dd->next = super->disk_mgmt_list;
                super->disk_mgmt_list = dd;
        } else {
                dd->next = super->disks;
                super->disks = dd;
                super->updates_pending++;
        }

        return 0;
}


static int remove_from_super_imsm(struct supertype *st, mdu_disk_info_t *dk)
{
        struct intel_super *super = st->sb;
        struct dl *dd;

        /* remove from super works only in mdmon - for communication
         * manager - monitor. Check if communication memory buffer
         * is prepared.
         */
        if (!st->update_tail) {
                fprintf(stderr,
                        Name ": %s shall be used in mdmon context only"
                        "(line %d).\n", __func__, __LINE__);
                return 1;
        }
        dd = malloc(sizeof(*dd));
        if (!dd) {
                fprintf(stderr,
                        Name ": malloc failed %s:%d.\n", __func__, __LINE__);
                return 1;
        }
        memset(dd, 0, sizeof(*dd));
        dd->major = dk->major;
        dd->minor = dk->minor;
        dd->index = -1;
        dd->fd = -1;
        dd->disk.status = SPARE_DISK;
        dd->action = DISK_REMOVE;

        dd->next = super->disk_mgmt_list;
        super->disk_mgmt_list = dd;


        return 0;
}

static int store_imsm_mpb(int fd, struct imsm_super *mpb);

static union {
        char buf[512];
        struct imsm_super anchor;
} spare_record __attribute__ ((aligned(512)));

/* spare records have their own family number and do not have any defined raid
 * devices
 */
static int write_super_imsm_spares(struct intel_super *super, int doclose)
{
        struct imsm_super *mpb = super->anchor;
        struct imsm_super *spare = &spare_record.anchor;
        __u32 sum;
        struct dl *d;

        spare->mpb_size = __cpu_to_le32(sizeof(struct imsm_super)),
        spare->generation_num = __cpu_to_le32(1UL),
        spare->attributes = MPB_ATTRIB_CHECKSUM_VERIFY;
        spare->num_disks = 1,
        spare->num_raid_devs = 0,
        spare->cache_size = mpb->cache_size,
        spare->pwr_cycle_count = __cpu_to_le32(1),

        snprintf((char *) spare->sig, MAX_SIGNATURE_LENGTH,
                 MPB_SIGNATURE MPB_VERSION_RAID0);

        for (d = super->disks; d; d = d->next) {
                if (d->index != -1)
                        continue;

                spare->disk[0] = d->disk;
                sum = __gen_imsm_checksum(spare);
                spare->family_num = __cpu_to_le32(sum);
                spare->orig_family_num = 0;
                sum = __gen_imsm_checksum(spare);
                spare->check_sum = __cpu_to_le32(sum);

                if (store_imsm_mpb(d->fd, spare)) {
                        fprintf(stderr, "%s: failed for device %d:%d %s\n",
                                __func__, d->major, d->minor, strerror(errno));
                        return 1;
                }
                if (doclose) {
                        close(d->fd);
                        d->fd = -1;
                }
        }

        return 0;
}

static int is_gen_migration(struct imsm_dev *dev);

static int write_super_imsm(struct supertype *st, int doclose)
{
        struct intel_super *super = st->sb;
        struct imsm_super *mpb = super->anchor;
        struct dl *d;
        __u32 generation;
        __u32 sum;
        int spares = 0;
        int i;
        __u32 mpb_size = sizeof(struct imsm_super) - sizeof(struct imsm_disk);
        int num_disks = 0;
        int clear_migration_record = 1;

        /* 'generation' is incremented everytime the metadata is written */
        generation = __le32_to_cpu(mpb->generation_num);
        generation++;
        mpb->generation_num = __cpu_to_le32(generation);

        /* fix up cases where previous mdadm releases failed to set
         * orig_family_num
         */
        if (mpb->orig_family_num == 0)
                mpb->orig_family_num = mpb->family_num;

        for (d = super->disks; d; d = d->next) {
                if (d->index == -1)
                        spares++;
                else {
                        mpb->disk[d->index] = d->disk;
                        num_disks++;
                }
        }
        for (d = super->missing; d; d = d->next) {
                mpb->disk[d->index] = d->disk;
                num_disks++;
        }
        mpb->num_disks = num_disks;
        mpb_size += sizeof(struct imsm_disk) * mpb->num_disks;

        for (i = 0; i < mpb->num_raid_devs; i++) {
                struct imsm_dev *dev = __get_imsm_dev(mpb, i);
                struct imsm_dev *dev2 = get_imsm_dev(super, i);
                if (dev && dev2) {
                        imsm_copy_dev(dev, dev2);
                        mpb_size += sizeof_imsm_dev(dev, 0);
                }
                if (is_gen_migration(dev2))
                        clear_migration_record = 0;
        }
        mpb_size += __le32_to_cpu(mpb->bbm_log_size);
        mpb->mpb_size = __cpu_to_le32(mpb_size);

        /* recalculate checksum */
        sum = __gen_imsm_checksum(mpb);
        mpb->check_sum = __cpu_to_le32(sum);

        if (clear_migration_record)
                memset(super->migr_rec_buf, 0, 512);

        /* write the mpb for disks that compose raid devices */
        for (d = super->disks; d ; d = d->next) {
                if (d->index < 0)
                        continue;
                if (store_imsm_mpb(d->fd, mpb))
                        fprintf(stderr, "%s: failed for device %d:%d %s\n",
                                __func__, d->major, d->minor, strerror(errno));
                if (clear_migration_record) {
                        unsigned long long dsize;

                        get_dev_size(d->fd, NULL, &dsize);
                        if (lseek64(d->fd, dsize - 512, SEEK_SET) >= 0) {
                                write(d->fd, super->migr_rec_buf, 512);
                        }
                }
                if (doclose) {
                        close(d->fd);
                        d->fd = -1;
                }
        }

        if (spares)
                return write_super_imsm_spares(super, doclose);

        return 0;
}


static int create_array(struct supertype *st, int dev_idx)
{
        size_t len;
        struct imsm_update_create_array *u;
        struct intel_super *super = st->sb;
        struct imsm_dev *dev = get_imsm_dev(super, dev_idx);
        struct imsm_map *map = get_imsm_map(dev, 0);
        struct disk_info *inf;
        struct imsm_disk *disk;
        int i;

        len = sizeof(*u) - sizeof(*dev) + sizeof_imsm_dev(dev, 0) +
              sizeof(*inf) * map->num_members;
        u = malloc(len);
        if (!u) {
                fprintf(stderr, "%s: failed to allocate update buffer\n",
                        __func__);
                return 1;
        }

        u->type = update_create_array;
        u->dev_idx = dev_idx;
        imsm_copy_dev(&u->dev, dev);
        inf = get_disk_info(u);
        for (i = 0; i < map->num_members; i++) {
                int idx = get_imsm_disk_idx(dev, i, -1);

                disk = get_imsm_disk(super, idx);
                serialcpy(inf[i].serial, disk->serial);
        }
        append_metadata_update(st, u, len);

        return 0;
}

static int mgmt_disk(struct supertype *st)
{
        struct intel_super *super = st->sb;
        size_t len;
        struct imsm_update_add_remove_disk *u;

        if (!super->disk_mgmt_list)
                return 0;

        len = sizeof(*u);
        u = malloc(len);
        if (!u) {
                fprintf(stderr, "%s: failed to allocate update buffer\n",
                        __func__);
                return 1;
        }

        u->type = update_add_remove_disk;
        append_metadata_update(st, u, len);

        return 0;
}

static int write_init_super_imsm(struct supertype *st)
{
        struct intel_super *super = st->sb;
        int current_vol = super->current_vol;

        /* we are done with current_vol reset it to point st at the container */
        super->current_vol = -1;

        if (st->update_tail) {
                /* queue the recently created array / added disk
                 * as a metadata update */
                int rv;

                /* determine if we are creating a volume or adding a disk */
                if (current_vol < 0) {
                        /* in the mgmt (add/remove) disk case we are running
                         * in mdmon context, so don't close fd's
                         */
                        return mgmt_disk(st);
                } else
                        rv = create_array(st, current_vol);

                return rv;
        } else {
                struct dl *d;
                for (d = super->disks; d; d = d->next)
                        Kill(d->devname, NULL, 0, 1, 1);
                return write_super_imsm(st, 1);
        }
}
#endif

static int store_super_imsm(struct supertype *st, int fd)
{
        struct intel_super *super = st->sb;
        struct imsm_super *mpb = super ? super->anchor : NULL;

        if (!mpb)
                return 1;

#ifndef MDASSEMBLE
        return store_imsm_mpb(fd, mpb);
#else
        return 1;
#endif
}

static int imsm_bbm_log_size(struct imsm_super *mpb)
{
        return __le32_to_cpu(mpb->bbm_log_size);
}

#ifndef MDASSEMBLE
static int validate_geometry_imsm_container(struct supertype *st, int level,
                                            int layout, int raiddisks, int chunk,
                                            unsigned long long size, char *dev,
                                            unsigned long long *freesize,
                                            int verbose)
{
        int fd;
        unsigned long long ldsize;
        struct intel_super *super=NULL;
        int rv = 0;

        if (level != LEVEL_CONTAINER)
                return 0;
        if (!dev)
                return 1;

        fd = open(dev, O_RDONLY|O_EXCL, 0);
        if (fd < 0) {
                if (verbose)
                        fprintf(stderr, Name ": imsm: Cannot open %s: %s\n",
                                dev, strerror(errno));
                return 0;
        }
        if (!get_dev_size(fd, dev, &ldsize)) {
                close(fd);
                return 0;
        }

        /* capabilities retrieve could be possible
         * note that there is no fd for the disks in array.
         */
        super = alloc_super();
        if (!super) {
                fprintf(stderr,
                        Name ": malloc of %zu failed.\n",
                        sizeof(*super));
                close(fd);
                return 0;
        }

        rv = find_intel_hba_capability(fd, super, verbose ? dev : NULL);
        if (rv != 0) {
#if DEBUG
                char str[256];
                fd2devname(fd, str);
                dprintf("validate_geometry_imsm_container: fd: %d %s orom: %p rv: %d raiddisk: %d\n",
                        fd, str, super->orom, rv, raiddisks);
#endif
                /* no orom/efi or non-intel hba of the disk */
                close(fd);
                free_imsm(super);
                return 0;
        }
        close(fd);
        if (super->orom && raiddisks > super->orom->tds) {
                if (verbose)
                        fprintf(stderr, Name ": %d exceeds maximum number of"
                                " platform supported disks: %d\n",
                                raiddisks, super->orom->tds);

                free_imsm(super);
                return 0;
        }

        *freesize = avail_size_imsm(st, ldsize >> 9);
        free_imsm(super);

        return 1;
}

static unsigned long long find_size(struct extent *e, int *idx, int num_extents)
{
        const unsigned long long base_start = e[*idx].start;
        unsigned long long end = base_start + e[*idx].size;
        int i;

        if (base_start == end)
                return 0;

        *idx = *idx + 1;
        for (i = *idx; i < num_extents; i++) {
                /* extend overlapping extents */
                if (e[i].start >= base_start &&
                    e[i].start <= end) {
                        if (e[i].size == 0)
                                return 0;
                        if (e[i].start + e[i].size > end)
                                end = e[i].start + e[i].size;
                } else if (e[i].start > end) {
                        *idx = i;
                        break;
                }
        }

        return end - base_start;
}

static unsigned long long merge_extents(struct intel_super *super, int sum_extents)
{
        /* build a composite disk with all known extents and generate a new
         * 'maxsize' given the "all disks in an array must share a common start
         * offset" constraint
         */
        struct extent *e = calloc(sum_extents, sizeof(*e));
        struct dl *dl;
        int i, j;
        int start_extent;
        unsigned long long pos;
        unsigned long long start = 0;
        unsigned long long maxsize;
        unsigned long reserve;

        if (!e)
                return 0;

        /* coalesce and sort all extents. also, check to see if we need to
         * reserve space between member arrays
         */
        j = 0;
        for (dl = super->disks; dl; dl = dl->next) {
                if (!dl->e)
                        continue;
                for (i = 0; i < dl->extent_cnt; i++)
                        e[j++] = dl->e[i];
        }
        qsort(e, sum_extents, sizeof(*e), cmp_extent);

        /* merge extents */
        i = 0;
        j = 0;
        while (i < sum_extents) {
                e[j].start = e[i].start;
                e[j].size = find_size(e, &i, sum_extents);
                j++;
                if (e[j-1].size == 0)
                        break;
        }

        pos = 0;
        maxsize = 0;
        start_extent = 0;
        i = 0;
        do {
                unsigned long long esize;

                esize = e[i].start - pos;
                if (esize >= maxsize) {
                        maxsize = esize;
                        start = pos;
                        start_extent = i;
                }
                pos = e[i].start + e[i].size;
                i++;
        } while (e[i-1].size);
        free(e);

        if (maxsize == 0)
                return 0;

        /* FIXME assumes volume at offset 0 is the first volume in a
         * container
         */
        if (start_extent > 0)
                reserve = IMSM_RESERVED_SECTORS; /* gap between raid regions */
        else
                reserve = 0;

        if (maxsize < reserve)
                return 0;

        super->create_offset = ~((__u32) 0);
        if (start + reserve > super->create_offset)
                return 0; /* start overflows create_offset */
        super->create_offset = start + reserve;

        return maxsize - reserve;
}

static int is_raid_level_supported(const struct imsm_orom *orom, int level, int raiddisks)
{
        if (level < 0 || level == 6 || level == 4)
                return 0;

        /* if we have an orom prevent invalid raid levels */
        if (orom)
                switch (level) {
                case 0: return imsm_orom_has_raid0(orom);
                case 1:
                        if (raiddisks > 2)
                                return imsm_orom_has_raid1e(orom);
                        return imsm_orom_has_raid1(orom) && raiddisks == 2;
                case 10: return imsm_orom_has_raid10(orom) && raiddisks == 4;
                case 5: return imsm_orom_has_raid5(orom) && raiddisks > 2;
                }
        else
                return 1; /* not on an Intel RAID platform so anything goes */

        return 0;
}


#define pr_vrb(fmt, arg...) (void) (verbose && fprintf(stderr, Name fmt, ##arg))
/*
 * validate volume parameters with OROM/EFI capabilities
 */
static int
validate_geometry_imsm_orom(struct intel_super *super, int level, int layout,
                            int raiddisks, int *chunk, int verbose)
{
#if DEBUG
        verbose = 1;
#endif
        /* validate container capabilities */
        if (super->orom && raiddisks > super->orom->tds) {
                if (verbose)
                        fprintf(stderr, Name ": %d exceeds maximum number of"
                                " platform supported disks: %d\n",
                                raiddisks, super->orom->tds);
                return 0;
        }

        /* capabilities of OROM tested - copied from validate_geometry_imsm_volume */
        if (super->orom && (!is_raid_level_supported(super->orom, level,
                                                     raiddisks))) {
                pr_vrb(": platform does not support raid%d with %d disk%s\n",
                        level, raiddisks, raiddisks > 1 ? "s" : "");
                return 0;
        }
        if (super->orom && level != 1) {
                if (chunk && (*chunk == 0 || *chunk == UnSet))
                        *chunk = imsm_orom_default_chunk(super->orom);
                else if (chunk && !imsm_orom_has_chunk(super->orom, *chunk)) {
                        pr_vrb(": platform does not support a chunk size of: "
                               "%d\n", *chunk);
                        return 0;
                }
        }
        if (layout != imsm_level_to_layout(level)) {
                if (level == 5)
                        pr_vrb(": imsm raid 5 only supports the left-asymmetric layout\n");
                else if (level == 10)
                        pr_vrb(": imsm raid 10 only supports the n2 layout\n");
                else
                        pr_vrb(": imsm unknown layout %#x for this raid level %d\n",
                                layout, level);
                return 0;
        }
        return 1;
}

/* validate_geometry_imsm_volume - lifted from validate_geometry_ddf_bvd 
 * FIX ME add ahci details
 */
static int validate_geometry_imsm_volume(struct supertype *st, int level,
                                         int layout, int raiddisks, int *chunk,
                                         unsigned long long size, char *dev,
                                         unsigned long long *freesize,
                                         int verbose)
{
        struct stat stb;
        struct intel_super *super = st->sb;
        struct imsm_super *mpb = super->anchor;
        struct dl *dl;
        unsigned long long pos = 0;
        unsigned long long maxsize;
        struct extent *e;
        int i;

        /* We must have the container info already read in. */
        if (!super)
                return 0;

        if (!validate_geometry_imsm_orom(super, level, layout, raiddisks, chunk, verbose)) {
                fprintf(stderr, Name ": RAID gemetry validation failed. "
                        "Cannot proceed with the action(s).\n");
                return 0;
        }
        if (!dev) {
                /* General test:  make sure there is space for
                 * 'raiddisks' device extents of size 'size' at a given
                 * offset
                 */
                unsigned long long minsize = size;
                unsigned long long start_offset = MaxSector;
                int dcnt = 0;
                if (minsize == 0)
                        minsize = MPB_SECTOR_CNT + IMSM_RESERVED_SECTORS;
                for (dl = super->disks; dl ; dl = dl->next) {
                        int found = 0;

                        pos = 0;
                        i = 0;
                        e = get_extents(super, dl);
                        if (!e) continue;
                        do {
                                unsigned long long esize;
                                esize = e[i].start - pos;
                                if (esize >= minsize)
                                        found = 1;
                                if (found && start_offset == MaxSector) {
                                        start_offset = pos;
                                        break;
                                } else if (found && pos != start_offset) {
                                        found = 0;
                                        break;
                                }
                                pos = e[i].start + e[i].size;
                                i++;
                        } while (e[i-1].size);
                        if (found)
                                dcnt++;
                        free(e);
                }
                if (dcnt < raiddisks) {
                        if (verbose)
                                fprintf(stderr, Name ": imsm: Not enough "
                                        "devices with space for this array "
                                        "(%d < %d)\n",
                                        dcnt, raiddisks);
                        return 0;
                }
                return 1;
        }

        /* This device must be a member of the set */
        if (stat(dev, &stb) < 0)
                return 0;
        if ((S_IFMT & stb.st_mode) != S_IFBLK)
                return 0;
        for (dl = super->disks ; dl ; dl = dl->next) {
                if (dl->major == (int)major(stb.st_rdev) &&
                    dl->minor == (int)minor(stb.st_rdev))
                        break;
        }
        if (!dl) {
                if (verbose)
                        fprintf(stderr, Name ": %s is not in the "
                                "same imsm set\n", dev);
                return 0;
        } else if (super->orom && dl->index < 0 && mpb->num_raid_devs) {
                /* If a volume is present then the current creation attempt
                 * cannot incorporate new spares because the orom may not
                 * understand this configuration (all member disks must be
                 * members of each array in the container).
                 */
                fprintf(stderr, Name ": %s is a spare and a volume"
                        " is already defined for this container\n", dev);
                fprintf(stderr, Name ": The option-rom requires all member"
                        " disks to be a member of all volumes\n");
                return 0;
        }

        /* retrieve the largest free space block */
        e = get_extents(super, dl);
        maxsize = 0;
        i = 0;
        if (e) {
                do {
                        unsigned long long esize;

                        esize = e[i].start - pos;
                        if (esize >= maxsize)
                                maxsize = esize;
                        pos = e[i].start + e[i].size;
                        i++;
                } while (e[i-1].size);
                dl->e = e;
                dl->extent_cnt = i;
        } else {
                if (verbose)
                        fprintf(stderr, Name ": unable to determine free space for: %s\n",
                                dev);
                return 0;
        }
        if (maxsize < size) {
                if (verbose)
                        fprintf(stderr, Name ": %s not enough space (%llu < %llu)\n",
                                dev, maxsize, size);
                return 0;
        }

        /* count total number of extents for merge */
        i = 0;
        for (dl = super->disks; dl; dl = dl->next)
                if (dl->e)
                        i += dl->extent_cnt;

        maxsize = merge_extents(super, i);
        if (maxsize < size || maxsize == 0) {
                if (verbose)
                        fprintf(stderr, Name ": not enough space after merge (%llu < %llu)\n",
                                maxsize, size);
                return 0;
        }

        *freesize = maxsize;

        return 1;
}

static int reserve_space(struct supertype *st, int raiddisks,
                         unsigned long long size, int chunk,
                         unsigned long long *freesize)
{
        struct intel_super *super = st->sb;
        struct imsm_super *mpb = super->anchor;
        struct dl *dl;
        int i;
        int extent_cnt;
        struct extent *e;
        unsigned long long maxsize;
        unsigned long long minsize;
        int cnt;
        int used;

        /* find the largest common start free region of the possible disks */
        used = 0;
        extent_cnt = 0;
        cnt = 0;
        for (dl = super->disks; dl; dl = dl->next) {
                dl->raiddisk = -1;

                if (dl->index >= 0)
                        used++;

                /* don't activate new spares if we are orom constrained
                 * and there is already a volume active in the container
                 */
                if (super->orom && dl->index < 0 && mpb->num_raid_devs)
                        continue;

                e = get_extents(super, dl);
                if (!e)
                        continue;
                for (i = 1; e[i-1].size; i++)
                        ;
                dl->e = e;
                dl->extent_cnt = i;
                extent_cnt += i;
                cnt++;
        }

        maxsize = merge_extents(super, extent_cnt);
        minsize = size;
        if (size == 0)
                /* chunk is in K */
                minsize = chunk * 2;

        if (cnt < raiddisks ||
            (super->orom && used && used != raiddisks) ||
            maxsize < minsize ||
            maxsize == 0) {
                fprintf(stderr, Name ": not enough devices with space to create array.\n");
                return 0; /* No enough free spaces large enough */
        }

        if (size == 0) {
                size = maxsize;
                if (chunk) {
                        size /= 2 * chunk;
                        size *= 2 * chunk;
                }
        }

        cnt = 0;
        for (dl = super->disks; dl; dl = dl->next)
                if (dl->e)
                        dl->raiddisk = cnt++;

        *freesize = size;

        return 1;
}

static int validate_geometry_imsm(struct supertype *st, int level, int layout,
                                  int raiddisks, int *chunk, unsigned long long size,
                                  char *dev, unsigned long long *freesize,
                                  int verbose)
{
        int fd, cfd;
        struct mdinfo *sra;
        int is_member = 0;

        /* load capability
         * if given unused devices create a container
         * if given given devices in a container create a member volume
         */
        if (level == LEVEL_CONTAINER) {
                /* Must be a fresh device to add to a container */
                return validate_geometry_imsm_container(st, level, layout,
                                                        raiddisks,
                                                        chunk?*chunk:0, size,
                                                        dev, freesize,
                                                        verbose);
        }
        
        if (!dev) {
                if (st->sb && freesize) {
                        /* we are being asked to automatically layout a
                         * new volume based on the current contents of
                         * the container.  If the the parameters can be
                         * satisfied reserve_space will record the disks,
                         * start offset, and size of the volume to be
                         * created.  add_to_super and getinfo_super
                         * detect when autolayout is in progress.
                         */
                        if (!validate_geometry_imsm_orom(st->sb, level, layout,
                                                         raiddisks, chunk,
                                                         verbose))
                                return 0;
                        return reserve_space(st, raiddisks, size,
                                             chunk?*chunk:0, freesize);
                }
                return 1;
        }
        if (st->sb) {
                /* creating in a given container */
                return validate_geometry_imsm_volume(st, level, layout,
                                                     raiddisks, chunk, size,
                                                     dev, freesize, verbose);
        }

        /* This device needs to be a device in an 'imsm' container */
        fd = open(dev, O_RDONLY|O_EXCL, 0);
        if (fd >= 0) {
                if (verbose)
                        fprintf(stderr,
                                Name ": Cannot create this array on device %s\n",
                                dev);
                close(fd);
                return 0;
        }
        if (errno != EBUSY || (fd = open(dev, O_RDONLY, 0)) < 0) {
                if (verbose)
                        fprintf(stderr, Name ": Cannot open %s: %s\n",
                                dev, strerror(errno));
                return 0;
        }
        /* Well, it is in use by someone, maybe an 'imsm' container. */
        cfd = open_container(fd);
        close(fd);
        if (cfd < 0) {
                if (verbose)
                        fprintf(stderr, Name ": Cannot use %s: It is busy\n",
                                dev);
                return 0;
        }
        sra = sysfs_read(cfd, 0, GET_VERSION);
        if (sra && sra->array.major_version == -1 &&
            strcmp(sra->text_version, "imsm") == 0)
                is_member = 1;
        sysfs_free(sra);
        if (is_member) {
                /* This is a member of a imsm container.  Load the container
                 * and try to create a volume
                 */
                struct intel_super *super;

                if (load_super_imsm_all(st, cfd, (void **) &super, NULL) == 0) {
                        st->sb = super;
                        st->container_dev = fd2devnum(cfd);
                        close(cfd);
                        return validate_geometry_imsm_volume(st, level, layout,
                                                             raiddisks, chunk,
                                                             size, dev,
                                                             freesize, verbose);
                }
        }

        if (verbose)
                fprintf(stderr, Name ": failed container membership check\n");

        close(cfd);
        return 0;
}

static void default_geometry_imsm(struct supertype *st, int *level, int *layout, int *chunk)
{
        struct intel_super *super = st->sb;

        if (level && *level == UnSet)
                *level = LEVEL_CONTAINER;

        if (level && layout && *layout == UnSet)
                *layout = imsm_level_to_layout(*level);

        if (chunk && (*chunk == UnSet || *chunk == 0) && 
            super && super->orom)
                *chunk = imsm_orom_default_chunk(super->orom);
}

static void handle_missing(struct intel_super *super, struct imsm_dev *dev);

static int kill_subarray_imsm(struct supertype *st)
{
        /* remove the subarray currently referenced by ->current_vol */
        __u8 i;
        struct intel_dev **dp;
        struct intel_super *super = st->sb;
        __u8 current_vol = super->current_vol;
        struct imsm_super *mpb = super->anchor;

        if (super->current_vol < 0)
                return 2;
        super->current_vol = -1; /* invalidate subarray cursor */

        /* block deletions that would change the uuid of active subarrays
         *
         * FIXME when immutable ids are available, but note that we'll
         * also need to fixup the invalidated/active subarray indexes in
         * mdstat
         */
        for (i = 0; i < mpb->num_raid_devs; i++) {
                char subarray[4];

                if (i < current_vol)
                        continue;
                sprintf(subarray, "%u", i);
                if (is_subarray_active(subarray, st->devname)) {
                        fprintf(stderr,
                                Name ": deleting subarray-%d would change the UUID of active subarray-%d, aborting\n",
                                current_vol, i);

                        return 2;
                }
        }

        if (st->update_tail) {
                struct imsm_update_kill_array *u = malloc(sizeof(*u));

                if (!u)
                        return 2;
                u->type = update_kill_array;
                u->dev_idx = current_vol;
                append_metadata_update(st, u, sizeof(*u));

                return 0;
        }

        for (dp = &super->devlist; *dp;)
                if ((*dp)->index == current_vol) {
                        *dp = (*dp)->next;
                } else {
                        handle_missing(super, (*dp)->dev);
                        if ((*dp)->index > current_vol)
                                (*dp)->index--;
                        dp = &(*dp)->next;
                }

        /* no more raid devices, all active components are now spares,
         * but of course failed are still failed
         */
        if (--mpb->num_raid_devs == 0) {
                struct dl *d;

                for (d = super->disks; d; d = d->next)
                        if (d->index > -2) {
                                d->index = -1;
                                d->disk.status = SPARE_DISK;
                        }
        }

        super->updates_pending++;

        return 0;
}

static int update_subarray_imsm(struct supertype *st, char *subarray,
                                char *update, struct mddev_ident *ident)
{
        /* update the subarray currently referenced by ->current_vol */
        struct intel_super *super = st->sb;
        struct imsm_super *mpb = super->anchor;

        if (strcmp(update, "name") == 0) {
                char *name = ident->name;
                char *ep;
                int vol;

                if (is_subarray_active(subarray, st->devname)) {
                        fprintf(stderr,
                                Name ": Unable to update name of active subarray\n");
                        return 2;
                }

                if (!check_name(super, name, 0))
                        return 2;

                vol = strtoul(subarray, &ep, 10);
                if (*ep != '\0' || vol >= super->anchor->num_raid_devs)
                        return 2;

                if (st->update_tail) {
                        struct imsm_update_rename_array *u = malloc(sizeof(*u));

                        if (!u)
                                return 2;
                        u->type = update_rename_array;
                        u->dev_idx = vol;
                        snprintf((char *) u->name, MAX_RAID_SERIAL_LEN, "%s", name);
                        append_metadata_update(st, u, sizeof(*u));
                } else {
                        struct imsm_dev *dev;
                        int i;

                        dev = get_imsm_dev(super, vol);
                        snprintf((char *) dev->volume, MAX_RAID_SERIAL_LEN, "%s", name);
                        for (i = 0; i < mpb->num_raid_devs; i++) {
                                dev = get_imsm_dev(super, i);
                                handle_missing(super, dev);
                        }
                        super->updates_pending++;
                }
        } else
                return 2;

        return 0;
}

static int is_gen_migration(struct imsm_dev *dev)
{
        if (!dev->vol.migr_state)
                return 0;

        if (migr_type(dev) == MIGR_GEN_MIGR)
                return 1;

        return 0;
}
#endif /* MDASSEMBLE */

static int is_rebuilding(struct imsm_dev *dev)
{
        struct imsm_map *migr_map;

        if (!dev->vol.migr_state)
                return 0;

        if (migr_type(dev) != MIGR_REBUILD)
                return 0;

        migr_map = get_imsm_map(dev, 1);

        if (migr_map->map_state == IMSM_T_STATE_DEGRADED)
                return 1;
        else
                return 0;
}

static void update_recovery_start(struct intel_super *super,
                                        struct imsm_dev *dev,
                                        struct mdinfo *array)
{
        struct mdinfo *rebuild = NULL;
        struct mdinfo *d;
        __u32 units;

        if (!is_rebuilding(dev))
                return;

        /* Find the rebuild target, but punt on the dual rebuild case */
        for (d = array->devs; d; d = d->next)
                if (d->recovery_start == 0) {
                        if (rebuild)
                                return;
                        rebuild = d;
                }

        if (!rebuild) {
                /* (?) none of the disks are marked with
                 * IMSM_ORD_REBUILD, so assume they are missing and the
                 * disk_ord_tbl was not correctly updated
                 */
                dprintf("%s: failed to locate out-of-sync disk\n", __func__);
                return;
        }

        units = __le32_to_cpu(dev->vol.curr_migr_unit);
        rebuild->recovery_start = units * blocks_per_migr_unit(super, dev);
}

static int recover_backup_imsm(struct supertype *st, struct mdinfo *info);

static struct mdinfo *container_content_imsm(struct supertype *st, char *subarray)
{
        /* Given a container loaded by load_super_imsm_all,
         * extract information about all the arrays into
         * an mdinfo tree.
         * If 'subarray' is given, just extract info about that array.
         *
         * For each imsm_dev create an mdinfo, fill it in,
         *  then look for matching devices in super->disks
         *  and create appropriate device mdinfo.
         */
        struct intel_super *super = st->sb;
        struct imsm_super *mpb = super->anchor;
        struct mdinfo *rest = NULL;
        unsigned int i;
        int bbm_errors = 0;
        struct dl *d;
        int spare_disks = 0;

        /* check for bad blocks */
        if (imsm_bbm_log_size(super->anchor))
                bbm_errors = 1;

        /* count spare devices, not used in maps
         */
        for (d = super->disks; d; d = d->next)
                if (d->index == -1)
                        spare_disks++;

        for (i = 0; i < mpb->num_raid_devs; i++) {
                struct imsm_dev *dev;
                struct imsm_map *map;
                struct imsm_map *map2;
                struct mdinfo *this;
                int slot, chunk;
                char *ep;

                if (subarray &&
                    (i != strtoul(subarray, &ep, 10) || *ep != '\0'))
                        continue;

                dev = get_imsm_dev(super, i);
                map = get_imsm_map(dev, 0);
                map2 = get_imsm_map(dev, 1);

                /* do not publish arrays that are in the middle of an
                 * unsupported migration
                 */
                if (dev->vol.migr_state &&
                    (migr_type(dev) == MIGR_STATE_CHANGE)) {
                        fprintf(stderr, Name ": cannot assemble volume '%.16s':"
                                " unsupported migration in progress\n",
                                dev->volume);
                        continue;
                }
                /* do not publish arrays that are not support by controller's
                 * OROM/EFI
                 */

                chunk = __le16_to_cpu(map->blocks_per_strip) >> 1;
#ifndef MDASSEMBLE
                if (!validate_geometry_imsm_orom(super,
                                                 get_imsm_raid_level(map), /* RAID level */
                                                 imsm_level_to_layout(get_imsm_raid_level(map)),
                                                 map->num_members, /* raid disks */
                                                 &chunk,
                                                 1 /* verbose */)) {
                        fprintf(stderr, Name ": RAID gemetry validation failed. "
                                "Cannot proceed with the action(s).\n");
                        continue;
                }
#endif /* MDASSEMBLE */
                this = malloc(sizeof(*this));
                if (!this) {
                        fprintf(stderr, Name ": failed to allocate %zu bytes\n",
                                sizeof(*this));
                        break;
                }
                memset(this, 0, sizeof(*this));
                this->next = rest;

                super->current_vol = i;
                getinfo_super_imsm_volume(st, this, NULL);
                for (slot = 0 ; slot <  map->num_members; slot++) {
                        unsigned long long recovery_start;
                        struct mdinfo *info_d;
                        struct dl *d;
                        int idx;
                        int skip;
                        __u32 ord;

                        skip = 0;
                        idx = get_imsm_disk_idx(dev, slot, 0);
                        ord = get_imsm_ord_tbl_ent(dev, slot, -1);
                        for (d = super->disks; d ; d = d->next)
                                if (d->index == idx)
                                        break;

                        recovery_start = MaxSector;
                        if (d == NULL)
                                skip = 1;
                        if (d && is_failed(&d->disk))
                                skip = 1;
                        if (ord & IMSM_ORD_REBUILD)
                                recovery_start = 0;

                        /* 
                         * if we skip some disks the array will be assmebled degraded;
                         * reset resync start to avoid a dirty-degraded
                         * situation when performing the intial sync
                         *
                         * FIXME handle dirty degraded
                         */
                        if ((skip || recovery_start == 0) && !dev->vol.dirty)
                                this->resync_start = MaxSector;
                        if (skip)
                                continue;

                        info_d = calloc(1, sizeof(*info_d));
                        if (!info_d) {
                                fprintf(stderr, Name ": failed to allocate disk"
                                        " for volume %.16s\n", dev->volume);
                                info_d = this->devs;
                                while (info_d) {
                                        struct mdinfo *d = info_d->next;

                                        free(info_d);
                                        info_d = d;
                                }
                                free(this);
                                this = rest;
                                break;
                        }
                        info_d->next = this->devs;
                        this->devs = info_d;

                        info_d->disk.number = d->index;
                        info_d->disk.major = d->major;
                        info_d->disk.minor = d->minor;
                        info_d->disk.raid_disk = slot;
                        info_d->recovery_start = recovery_start;
                        if (map2) {
                                if (slot < map2->num_members)
                                        info_d->disk.state = (1 << MD_DISK_ACTIVE);
                                else
                                        this->array.spare_disks++;
                        } else {
                                if (slot < map->num_members)
                                        info_d->disk.state = (1 << MD_DISK_ACTIVE);
                                else
                                        this->array.spare_disks++;
                        }
                        if (info_d->recovery_start == MaxSector)
                                this->array.working_disks++;

                        info_d->events = __le32_to_cpu(mpb->generation_num);
                        info_d->data_offset = __le32_to_cpu(map->pba_of_lba0);
                        info_d->component_size = __le32_to_cpu(map->blocks_per_member);
                }
                /* now that the disk list is up-to-date fixup recovery_start */
                update_recovery_start(super, dev, this);
                this->array.spare_disks += spare_disks;

                /* check for reshape */
                if (this->reshape_active == 1)
                        recover_backup_imsm(st, this);

                rest = this;
        }

        /* if array has bad blocks, set suitable bit in array status */
        if (bbm_errors)
                rest->array.state |= (1<<MD_SB_BBM_ERRORS);

        return rest;
}


static __u8 imsm_check_degraded(struct intel_super *super, struct imsm_dev *dev, int failed)
{
        struct imsm_map *map = get_imsm_map(dev, 0);

        if (!failed)
                return map->map_state == IMSM_T_STATE_UNINITIALIZED ? 
                        IMSM_T_STATE_UNINITIALIZED : IMSM_T_STATE_NORMAL;

        switch (get_imsm_raid_level(map)) {
        case 0:
                return IMSM_T_STATE_FAILED;
                break;
        case 1:
                if (failed < map->num_members)
                        return IMSM_T_STATE_DEGRADED;
                else
                        return IMSM_T_STATE_FAILED;
                break;
        case 10:
        {
                /**
                 * check to see if any mirrors have failed, otherwise we
                 * are degraded.  Even numbered slots are mirrored on
                 * slot+1
                 */
                int i;
                /* gcc -Os complains that this is unused */
                int insync = insync;

                for (i = 0; i < map->num_members; i++) {
                        __u32 ord = get_imsm_ord_tbl_ent(dev, i, -1);
                        int idx = ord_to_idx(ord);
                        struct imsm_disk *disk;

                        /* reset the potential in-sync count on even-numbered
                         * slots.  num_copies is always 2 for imsm raid10 
                         */
                        if ((i & 1) == 0)
                                insync = 2;

                        disk = get_imsm_disk(super, idx);
                        if (!disk || is_failed(disk) || ord & IMSM_ORD_REBUILD)
                                insync--;

                        /* no in-sync disks left in this mirror the
                         * array has failed
                         */
                        if (insync == 0)
                                return IMSM_T_STATE_FAILED;
                }

                return IMSM_T_STATE_DEGRADED;
        }
        case 5:
                if (failed < 2)
                        return IMSM_T_STATE_DEGRADED;
                else
                        return IMSM_T_STATE_FAILED;
                break;
        default:
                break;
        }

        return map->map_state;
}

static int imsm_count_failed(struct intel_super *super, struct imsm_dev *dev)
{
        int i;
        int failed = 0;
        struct imsm_disk *disk;
        struct imsm_map *map = get_imsm_map(dev, 0);
        struct imsm_map *prev = get_imsm_map(dev, dev->vol.migr_state);
        __u32 ord;
        int idx;

        /* at the beginning of migration we set IMSM_ORD_REBUILD on
         * disks that are being rebuilt.  New failures are recorded to
         * map[0].  So we look through all the disks we started with and
         * see if any failures are still present, or if any new ones
         * have arrived
         *
         * FIXME add support for online capacity expansion and
         * raid-level-migration
         */
        for (i = 0; i < prev->num_members; i++) {
                ord = __le32_to_cpu(prev->disk_ord_tbl[i]);
                ord |= __le32_to_cpu(map->disk_ord_tbl[i]);
                idx = ord_to_idx(ord);

                disk = get_imsm_disk(super, idx);
                if (!disk || is_failed(disk) || ord & IMSM_ORD_REBUILD)
                        failed++;
        }

        return failed;
}

#ifndef MDASSEMBLE
static int imsm_open_new(struct supertype *c, struct active_array *a,
                         char *inst)
{
        struct intel_super *super = c->sb;
        struct imsm_super *mpb = super->anchor;
        
        if (atoi(inst) >= mpb->num_raid_devs) {
                fprintf(stderr, "%s: subarry index %d, out of range\n",
                        __func__, atoi(inst));
                return -ENODEV;
        }

        dprintf("imsm: open_new %s\n", inst);
        a->info.container_member = atoi(inst);
        return 0;
}

static int is_resyncing(struct imsm_dev *dev)
{
        struct imsm_map *migr_map;

        if (!dev->vol.migr_state)
                return 0;

        if (migr_type(dev) == MIGR_INIT ||
            migr_type(dev) == MIGR_REPAIR)
                return 1;

        if (migr_type(dev) == MIGR_GEN_MIGR)
                return 0;

        migr_map = get_imsm_map(dev, 1);

        if ((migr_map->map_state == IMSM_T_STATE_NORMAL) &&
            (dev->vol.migr_type != MIGR_GEN_MIGR))
                return 1;
        else
                return 0;
}

/* return true if we recorded new information */
static int mark_failure(struct imsm_dev *dev, struct imsm_disk *disk, int idx)
{
        __u32 ord;
        int slot;
        struct imsm_map *map;

        /* new failures are always set in map[0] */
        map = get_imsm_map(dev, 0);

        slot = get_imsm_disk_slot(map, idx);
        if (slot < 0)
                return 0;

        ord = __le32_to_cpu(map->disk_ord_tbl[slot]);
        if (is_failed(disk) && (ord & IMSM_ORD_REBUILD))
                return 0;

        disk->status |= FAILED_DISK;
        set_imsm_ord_tbl_ent(map, slot, idx | IMSM_ORD_REBUILD);
        if (map->failed_disk_num == 0xff)
                map->failed_disk_num = slot;
        return 1;
}

static void mark_missing(struct imsm_dev *dev, struct imsm_disk *disk, int idx)
{
        mark_failure(dev, disk, idx);

        if (disk->scsi_id == __cpu_to_le32(~(__u32)0))
                return;

        disk->scsi_id = __cpu_to_le32(~(__u32)0);
        memmove(&disk->serial[0], &disk->serial[1], MAX_RAID_SERIAL_LEN - 1);
}

static void handle_missing(struct intel_super *super, struct imsm_dev *dev)
{
        __u8 map_state;
        struct dl *dl;
        int failed;

        if (!super->missing)
                return;
        failed = imsm_count_failed(super, dev);
        map_state = imsm_check_degraded(super, dev, failed);

        dprintf("imsm: mark missing\n");
        end_migration(dev, map_state);
        for (dl = super->missing; dl; dl = dl->next)
                mark_missing(dev, &dl->disk, dl->index);
        super->updates_pending++;
}

static unsigned long long imsm_set_array_size(struct imsm_dev *dev)
{
        int used_disks = imsm_num_data_members(dev, 0);
        unsigned long long array_blocks;
        struct imsm_map *map;

        if (used_disks == 0) {
                /* when problems occures
                 * return current array_blocks value
                 */
                array_blocks = __le32_to_cpu(dev->size_high);
                array_blocks = array_blocks << 32;
                array_blocks += __le32_to_cpu(dev->size_low);

                return array_blocks;
        }

        /* set array size in metadata
         */
        map = get_imsm_map(dev, 0);
        array_blocks = map->blocks_per_member * used_disks;

        /* round array size down to closest MB
         */
        array_blocks = (array_blocks >> SECT_PER_MB_SHIFT) << SECT_PER_MB_SHIFT;
        dev->size_low = __cpu_to_le32((__u32)array_blocks);
        dev->size_high = __cpu_to_le32((__u32)(array_blocks >> 32));

        return array_blocks;
}

static void imsm_set_disk(struct active_array *a, int n, int state);

static void imsm_progress_container_reshape(struct intel_super *super)
{
        /* if no device has a migr_state, but some device has a
         * different number of members than the previous device, start
         * changing the number of devices in this device to match
         * previous.
         */
        struct imsm_super *mpb = super->anchor;
        int prev_disks = -1;
        int i;
        int copy_map_size;

        for (i = 0; i < mpb->num_raid_devs; i++) {
                struct imsm_dev *dev = get_imsm_dev(super, i);
                struct imsm_map *map = get_imsm_map(dev, 0);
                struct imsm_map *map2;
                int prev_num_members;

                if (dev->vol.migr_state)
                        return;

                if (prev_disks == -1)
                        prev_disks = map->num_members;
                if (prev_disks == map->num_members)
                        continue;

                /* OK, this array needs to enter reshape mode.
                 * i.e it needs a migr_state
                 */

                copy_map_size = sizeof_imsm_map(map);
                prev_num_members = map->num_members;
                map->num_members = prev_disks;
                dev->vol.migr_state = 1;
                dev->vol.curr_migr_unit = 0;
                dev->vol.migr_type = MIGR_GEN_MIGR;
                for (i = prev_num_members;
                     i < map->num_members; i++)
                        set_imsm_ord_tbl_ent(map, i, i);
                map2 = get_imsm_map(dev, 1);
                /* Copy the current map */
                memcpy(map2, map, copy_map_size);
                map2->num_members = prev_num_members;

                imsm_set_array_size(dev);
                super->updates_pending++;
        }
}

/* Handle dirty -> clean transititions, resync and reshape.  Degraded and rebuild
 * states are handled in imsm_set_disk() with one exception, when a
 * resync is stopped due to a new failure this routine will set the
 * 'degraded' state for the array.
 */
static int imsm_set_array_state(struct active_array *a, int consistent)
{
        int inst = a->info.container_member;
        struct intel_super *super = a->container->sb;
        struct imsm_dev *dev = get_imsm_dev(super, inst);
        struct imsm_map *map = get_imsm_map(dev, 0);
        int failed = imsm_count_failed(super, dev);
        __u8 map_state = imsm_check_degraded(super, dev, failed);
        __u32 blocks_per_unit;

        if (dev->vol.migr_state &&
            dev->vol.migr_type  == MIGR_GEN_MIGR) {
                /* array state change is blocked due to reshape action
                 * We might need to
                 * - abort the reshape (if last_checkpoint is 0 and action!= reshape)
                 * - finish the reshape (if last_checkpoint is big and action != reshape)
                 * - update curr_migr_unit
                 */
                if (a->curr_action == reshape) {
                        /* still reshaping, maybe update curr_migr_unit */
                        goto mark_checkpoint;
                } else {
                        if (a->last_checkpoint == 0 && a->prev_action == reshape) {
                                /* for some reason we aborted the reshape.
                                 * Better clean up
                                 */
                                struct imsm_map *map2 = get_imsm_map(dev, 1);
                                dev->vol.migr_state = 0;
                                dev->vol.migr_type = 0;
                                dev->vol.curr_migr_unit = 0;
                                memcpy(map, map2, sizeof_imsm_map(map2));
                                super->updates_pending++;
                        }
                        if (a->last_checkpoint >= a->info.component_size) {
                                unsigned long long array_blocks;
                                int used_disks;
                                struct mdinfo *mdi;

                                used_disks = imsm_num_data_members(dev, 0);
                                if (used_disks > 0) {
                                        array_blocks =
                                                map->blocks_per_member *
                                                used_disks;
                                        /* round array size down to closest MB
                                         */
                                        array_blocks = (array_blocks
                                                        >> SECT_PER_MB_SHIFT)
                                                << SECT_PER_MB_SHIFT;
                                        a->info.custom_array_size = array_blocks;
                                        /* encourage manager to update array
                                         * size
                                         */

                                        a->check_reshape = 1;
                                }
                                /* finalize online capacity expansion/reshape */
                                for (mdi = a->info.devs; mdi; mdi = mdi->next)
                                        imsm_set_disk(a,
                                                      mdi->disk.raid_disk,
                                                      mdi->curr_state);

                                imsm_progress_container_reshape(super);
                        }
                }
        }

        /* before we activate this array handle any missing disks */
        if (consistent == 2)
                handle_missing(super, dev);

        if (consistent == 2 &&
            (!is_resync_complete(&a->info) ||
             map_state != IMSM_T_STATE_NORMAL ||
             dev->vol.migr_state))
                consistent = 0;

        if (is_resync_complete(&a->info)) {
                /* complete intialization / resync,
                 * recovery and interrupted recovery is completed in
                 * ->set_disk
                 */
                if (is_resyncing(dev)) {
                        dprintf("imsm: mark resync done\n");
                        end_migration(dev, map_state);
                        super->updates_pending++;
                        a->last_checkpoint = 0;
                }
        } else if (!is_resyncing(dev) && !failed) {
                /* mark the start of the init process if nothing is failed */
                dprintf("imsm: mark resync start\n");
                if (map->map_state == IMSM_T_STATE_UNINITIALIZED)
                        migrate(dev, super, IMSM_T_STATE_NORMAL, MIGR_INIT);
                else
                        migrate(dev, super, IMSM_T_STATE_NORMAL, MIGR_REPAIR);
                super->updates_pending++;
        }

mark_checkpoint:
        /* skip checkpointing for general migration,
         * it is controlled in mdadm
         */
        if (is_gen_migration(dev))
                goto skip_mark_checkpoint;

        /* check if we can update curr_migr_unit from resync_start, recovery_start */
        blocks_per_unit = blocks_per_migr_unit(super, dev);
        if (blocks_per_unit) {
                __u32 units32;
                __u64 units;

                units = a->last_checkpoint / blocks_per_unit;
                units32 = units;

                /* check that we did not overflow 32-bits, and that
                 * curr_migr_unit needs updating
                 */
                if (units32 == units &&
                    units32 != 0 &&
                    __le32_to_cpu(dev->vol.curr_migr_unit) != units32) {
                        dprintf("imsm: mark checkpoint (%u)\n", units32);
                        dev->vol.curr_migr_unit = __cpu_to_le32(units32);
                        super->updates_pending++;
                }
        }

skip_mark_checkpoint:
        /* mark dirty / clean */
        if (dev->vol.dirty != !consistent) {
                dprintf("imsm: mark '%s'\n", consistent ? "clean" : "dirty");
                if (consistent)
                        dev->vol.dirty = 0;
                else
                        dev->vol.dirty = 1;
                super->updates_pending++;
        }

        return consistent;
}

static void imsm_set_disk(struct active_array *a, int n, int state)
{
        int inst = a->info.container_member;
        struct intel_super *super = a->container->sb;
        struct imsm_dev *dev = get_imsm_dev(super, inst);
        struct imsm_map *map = get_imsm_map(dev, 0);
        struct imsm_disk *disk;
        int failed;
        __u32 ord;
        __u8 map_state;

        if (n > map->num_members)
                fprintf(stderr, "imsm: set_disk %d out of range 0..%d\n",
                        n, map->num_members - 1);

        if (n < 0)
                return;

        dprintf("imsm: set_disk %d:%x\n", n, state);

        ord = get_imsm_ord_tbl_ent(dev, n, -1);
        disk = get_imsm_disk(super, ord_to_idx(ord));

        /* check for new failures */
        if (state & DS_FAULTY) {
                if (mark_failure(dev, disk, ord_to_idx(ord)))
                        super->updates_pending++;
        }

        /* check if in_sync */
        if (state & DS_INSYNC && ord & IMSM_ORD_REBUILD && is_rebuilding(dev)) {
                struct imsm_map *migr_map = get_imsm_map(dev, 1);

                set_imsm_ord_tbl_ent(migr_map, n, ord_to_idx(ord));
                super->updates_pending++;
        }

        failed = imsm_count_failed(super, dev);
        map_state = imsm_check_degraded(super, dev, failed);

        /* check if recovery complete, newly degraded, or failed */
        if (map_state == IMSM_T_STATE_NORMAL && is_rebuilding(dev)) {
                end_migration(dev, map_state);
                map = get_imsm_map(dev, 0);
                map->failed_disk_num = ~0;
                super->updates_pending++;
                a->last_checkpoint = 0;
        } else if (map_state == IMSM_T_STATE_DEGRADED &&
                   map->map_state != map_state &&
                   !dev->vol.migr_state) {
                dprintf("imsm: mark degraded\n");
                map->map_state = map_state;
                super->updates_pending++;
                a->last_checkpoint = 0;
        } else if (map_state == IMSM_T_STATE_FAILED &&
                   map->map_state != map_state) {
                dprintf("imsm: mark failed\n");
                end_migration(dev, map_state);
                super->updates_pending++;
                a->last_checkpoint = 0;
        } else if (is_gen_migration(dev)) {
                dprintf("imsm: Detected General Migration in state: ");
                if (map_state == IMSM_T_STATE_NORMAL) {
                        end_migration(dev, map_state);
                        map = get_imsm_map(dev, 0);
                        map->failed_disk_num = ~0;
                        dprintf("normal\n");
                } else {
                        if (map_state == IMSM_T_STATE_DEGRADED) {
                                printf("degraded\n");
                                end_migration(dev, map_state);
                        } else {
                                dprintf("failed\n");
                        }
                        map->map_state = map_state;
                }
                super->updates_pending++;
        }
}

static int store_imsm_mpb(int fd, struct imsm_super *mpb)
{
        void *buf = mpb;
        __u32 mpb_size = __le32_to_cpu(mpb->mpb_size);
        unsigned long long dsize;
        unsigned long long sectors;

        get_dev_size(fd, NULL, &dsize);

        if (mpb_size > 512) {
                /* -1 to account for anchor */
                sectors = mpb_sectors(mpb) - 1;

                /* write the extended mpb to the sectors preceeding the anchor */
                if (lseek64(fd, dsize - (512 * (2 + sectors)), SEEK_SET) < 0)
                        return 1;

                if ((unsigned long long)write(fd, buf + 512, 512 * sectors)
                    != 512 * sectors)
                        return 1;
        }

        /* first block is stored on second to last sector of the disk */
        if (lseek64(fd, dsize - (512 * 2), SEEK_SET) < 0)
                return 1;

        if (write(fd, buf, 512) != 512)
                return 1;

        return 0;
}

static void imsm_sync_metadata(struct supertype *container)
{
        struct intel_super *super = container->sb;

        dprintf("sync metadata: %d\n", super->updates_pending);
        if (!super->updates_pending)
                return;

        write_super_imsm(container, 0);

        super->updates_pending = 0;
}

static struct dl *imsm_readd(struct intel_super *super, int idx, struct active_array *a)
{
        struct imsm_dev *dev = get_imsm_dev(super, a->info.container_member);
        int i = get_imsm_disk_idx(dev, idx, -1);
        struct dl *dl;

        for (dl = super->disks; dl; dl = dl->next)
                if (dl->index == i)
                        break;

        if (dl && is_failed(&dl->disk))
                dl = NULL;

        if (dl)
                dprintf("%s: found %x:%x\n", __func__, dl->major, dl->minor);

        return dl;
}

static struct dl *imsm_add_spare(struct intel_super *super, int slot,
                                 struct active_array *a, int activate_new,
                                 struct mdinfo *additional_test_list)
{
        struct imsm_dev *dev = get_imsm_dev(super, a->info.container_member);
        int idx = get_imsm_disk_idx(dev, slot, -1);
        struct imsm_super *mpb = super->anchor;
        struct imsm_map *map;
        unsigned long long pos;
        struct mdinfo *d;
        struct extent *ex;
        int i, j;
        int found;
        __u32 array_start = 0;
        __u32 array_end = 0;
        struct dl *dl;
        struct mdinfo *test_list;

        for (dl = super->disks; dl; dl = dl->next) {
                /* If in this array, skip */
                for (d = a->info.devs ; d ; d = d->next)
                        if (d->state_fd >= 0 &&
                            d->disk.major == dl->major &&
                            d->disk.minor == dl->minor) {
                                dprintf("%x:%x already in array\n",
                                        dl->major, dl->minor);
                                break;
                        }
                if (d)
                        continue;
                test_list = additional_test_list;
                while (test_list) {
                        if (test_list->disk.major == dl->major &&
                            test_list->disk.minor == dl->minor) {
                                dprintf("%x:%x already in additional test list\n",
                                        dl->major, dl->minor);
                                break;
                        }
                        test_list = test_list->next;
                }
                if (test_list)
                        continue;

                /* skip in use or failed drives */
                if (is_failed(&dl->disk) || idx == dl->index ||
                    dl->index == -2) {
                        dprintf("%x:%x status (failed: %d index: %d)\n",
                                dl->major, dl->minor, is_failed(&dl->disk), idx);
                        continue;
                }

                /* skip pure spares when we are looking for partially
                 * assimilated drives
                 */
                if (dl->index == -1 && !activate_new)
                        continue;

                /* Does this unused device have the requisite free space?
                 * It needs to be able to cover all member volumes
                 */
                ex = get_extents(super, dl);
                if (!ex) {
                        dprintf("cannot get extents\n");
                        continue;
                }
                for (i = 0; i < mpb->num_raid_devs; i++) {
                        dev = get_imsm_dev(super, i);
                        map = get_imsm_map(dev, 0);

                        /* check if this disk is already a member of
                         * this array
                         */
                        if (get_imsm_disk_slot(map, dl->index) >= 0)
                                continue;

                        found = 0;
                        j = 0;
                        pos = 0;
                        array_start = __le32_to_cpu(map->pba_of_lba0);
                        array_end = array_start +
                                    __le32_to_cpu(map->blocks_per_member) - 1;

                        do {
                                /* check that we can start at pba_of_lba0 with
                                 * blocks_per_member of space
                                 */
                                if (array_start >= pos && array_end < ex[j].start) {
                                        found = 1;
                                        break;
                                }
                                pos = ex[j].start + ex[j].size;
                                j++;
                        } while (ex[j-1].size);

                        if (!found)
                                break;
                }

                free(ex);
                if (i < mpb->num_raid_devs) {
                        dprintf("%x:%x does not have %u to %u available\n",
                                dl->major, dl->minor, array_start, array_end);
                        /* No room */
                        continue;
                }
                return dl;
        }

        return dl;
}


static int imsm_rebuild_allowed(struct supertype *cont, int dev_idx, int failed)
{
        struct imsm_dev *dev2;
        struct imsm_map *map;
        struct dl *idisk;
        int slot;
        int idx;
        __u8 state;

        dev2 = get_imsm_dev(cont->sb, dev_idx);
        if (dev2) {
                state = imsm_check_degraded(cont->sb, dev2, failed);
                if (state == IMSM_T_STATE_FAILED) {
                        map = get_imsm_map(dev2, 0);
                        if (!map)
                                return 1;
                        for (slot = 0; slot < map->num_members; slot++) {
                                /*
                                 * Check if failed disks are deleted from intel
                                 * disk list or are marked to be deleted
                                 */
                                idx = get_imsm_disk_idx(dev2, slot, -1);
                                idisk = get_imsm_dl_disk(cont->sb, idx);
                                /*
                                 * Do not rebuild the array if failed disks
                                 * from failed sub-array are not removed from
                                 * container.
                                 */
                                if (idisk &&
                                    is_failed(&idisk->disk) &&
                                    (idisk->action != DISK_REMOVE))
                                        return 0;
                        }
                }
        }
        return 1;
}

static struct mdinfo *imsm_activate_spare(struct active_array *a,
                                          struct metadata_update **updates)
{
        /**
         * Find a device with unused free space and use it to replace a
         * failed/vacant region in an array.  We replace failed regions one a
         * array at a time.  The result is that a new spare disk will be added
         * to the first failed array and after the monitor has finished
         * propagating failures the remainder will be consumed.
         *
         * FIXME add a capability for mdmon to request spares from another
         * container.
         */

        struct intel_super *super = a->container->sb;
        int inst = a->info.container_member;
        struct imsm_dev *dev = get_imsm_dev(super, inst);
        struct imsm_map *map = get_imsm_map(dev, 0);
        int failed = a->info.array.raid_disks;
        struct mdinfo *rv = NULL;
        struct mdinfo *d;
        struct mdinfo *di;
        struct metadata_update *mu;
        struct dl *dl;
        struct imsm_update_activate_spare *u;
        int num_spares = 0;
        int i;
        int allowed;

        for (d = a->info.devs ; d ; d = d->next) {
                if ((d->curr_state & DS_FAULTY) &&
                        d->state_fd >= 0)
                        /* wait for Removal to happen */
                        return NULL;
                if (d->state_fd >= 0)
                        failed--;
        }

        dprintf("imsm: activate spare: inst=%d failed=%d (%d) level=%d\n",
                inst, failed, a->info.array.raid_disks, a->info.array.level);

        if (dev->vol.migr_state &&
            dev->vol.migr_type == MIGR_GEN_MIGR)
                /* No repair during migration */
                return NULL;

        if (a->info.array.level == 4)
                /* No repair for takeovered array
                 * imsm doesn't support raid4
                 */
                return NULL;

        if (imsm_check_degraded(super, dev, failed) != IMSM_T_STATE_DEGRADED)
                return NULL;

        /*
         * If there are any failed disks check state of the other volume.
         * Block rebuild if the another one is failed until failed disks
         * are removed from container.
         */
        if (failed) {
                dprintf("found failed disks in %s, check if there another"
                        "failed sub-array.\n",
                        dev->volume);
                /* check if states of the other volumes allow for rebuild */
                for (i = 0; i <  super->anchor->num_raid_devs; i++) {
                        if (i != inst) {
                                allowed = imsm_rebuild_allowed(a->container,
                                                               i, failed);
                                if (!allowed)
                                        return NULL;
                        }
                }
        }

        /* For each slot, if it is not working, find a spare */
        for (i = 0; i < a->info.array.raid_disks; i++) {
                for (d = a->info.devs ; d ; d = d->next)
                        if (d->disk.raid_disk == i)
                                break;
                dprintf("found %d: %p %x\n", i, d, d?d->curr_state:0);
                if (d && (d->state_fd >= 0))
                        continue;

                /*
                 * OK, this device needs recovery.  Try to re-add the
                 * previous occupant of this slot, if this fails see if
                 * we can continue the assimilation of a spare that was
                 * partially assimilated, finally try to activate a new
                 * spare.
                 */
                dl = imsm_readd(super, i, a);
                if (!dl)
                        dl = imsm_add_spare(super, i, a, 0, NULL);
                if (!dl)
                        dl = imsm_add_spare(super, i, a, 1, NULL);
                if (!dl)
                        continue;
 
                /* found a usable disk with enough space */
                di = malloc(sizeof(*di));
                if (!di)
                        continue;
                memset(di, 0, sizeof(*di));

                /* dl->index will be -1 in the case we are activating a
                 * pristine spare.  imsm_process_update() will create a
                 * new index in this case.  Once a disk is found to be
                 * failed in all member arrays it is kicked from the
                 * metadata
                 */
                di->disk.number = dl->index;

                /* (ab)use di->devs to store a pointer to the device
                 * we chose
                 */
                di->devs = (struct mdinfo *) dl;

                di->disk.raid_disk = i;
                di->disk.major = dl->major;
                di->disk.minor = dl->minor;
                di->disk.state = 0;
                di->recovery_start = 0;
                di->data_offset = __le32_to_cpu(map->pba_of_lba0);
                di->component_size = a->info.component_size;
                di->container_member = inst;
                super->random = random32();
                di->next = rv;
                rv = di;
                num_spares++;
                dprintf("%x:%x to be %d at %llu\n", dl->major, dl->minor,
                        i, di->data_offset);

                break;
        }

        if (!rv)
                /* No spares found */
                return rv;
        /* Now 'rv' has a list of devices to return.
         * Create a metadata_update record to update the
         * disk_ord_tbl for the array
         */
        mu = malloc(sizeof(*mu));
        if (mu) {
                mu->buf = malloc(sizeof(struct imsm_update_activate_spare) * num_spares);
                if (mu->buf == NULL) {
                        free(mu);
                        mu = NULL;
                }
        }
        if (!mu) {
                while (rv) {
                        struct mdinfo *n = rv->next;

                        free(rv);
                        rv = n;
                }
                return NULL;
        }
                        
        mu->space = NULL;
        mu->space_list = NULL;
        mu->len = sizeof(struct imsm_update_activate_spare) * num_spares;
        mu->next = *updates;
        u = (struct imsm_update_activate_spare *) mu->buf;

        for (di = rv ; di ; di = di->next) {
                u->type = update_activate_spare;
                u->dl = (struct dl *) di->devs;
                di->devs = NULL;
                u->slot = di->disk.raid_disk;
                u->array = inst;
                u->next = u + 1;
                u++;
        }
        (u-1)->next = NULL;
        *updates = mu;

        return rv;
}

static int disks_overlap(struct intel_super *super, int idx, struct imsm_update_create_array *u)
{
        struct imsm_dev *dev = get_imsm_dev(super, idx);
        struct imsm_map *map = get_imsm_map(dev, 0);
        struct imsm_map *new_map = get_imsm_map(&u->dev, 0);
        struct disk_info *inf = get_disk_info(u);
        struct imsm_disk *disk;
        int i;
        int j;

        for (i = 0; i < map->num_members; i++) {
                disk = get_imsm_disk(super, get_imsm_disk_idx(dev, i, -1));
                for (j = 0; j < new_map->num_members; j++)
                        if (serialcmp(disk->serial, inf[j].serial) == 0)
                                return 1;
        }

        return 0;
}


static struct dl *get_disk_super(struct intel_super *super, int major, int minor)
{
        struct dl *dl = NULL;
        for (dl = super->disks; dl; dl = dl->next)
                if ((dl->major == major) &&  (dl->minor == minor))
                        return dl;
        return NULL;
}

static int remove_disk_super(struct intel_super *super, int major, int minor)
{
        struct dl *prev = NULL;
        struct dl *dl;

        prev = NULL;
        for (dl = super->disks; dl; dl = dl->next) {
                if ((dl->major == major) && (dl->minor == minor)) {
                        /* remove */
                        if (prev)
                                prev->next = dl->next;
                        else
                                super->disks = dl->next;
                        dl->next = NULL;
                        __free_imsm_disk(dl);
                        dprintf("%s: removed %x:%x\n",
                                __func__, major, minor);
                        break;
                }
                prev = dl;
        }
        return 0;
}

static void imsm_delete(struct intel_super *super, struct dl **dlp, unsigned index);

static int add_remove_disk_update(struct intel_super *super)
{
        int check_degraded = 0;
        struct dl *disk = NULL;
        /* add/remove some spares to/from the metadata/contrainer */
        while (super->disk_mgmt_list) {
                struct dl *disk_cfg;

                disk_cfg = super->disk_mgmt_list;
                super->disk_mgmt_list = disk_cfg->next;
                disk_cfg->next = NULL;

                if (disk_cfg->action == DISK_ADD) {
                        disk_cfg->next = super->disks;
                        super->disks = disk_cfg;
                        check_degraded = 1;
                        dprintf("%s: added %x:%x\n",
                                __func__, disk_cfg->major,
                                disk_cfg->minor);
                } else if (disk_cfg->action == DISK_REMOVE) {
                        dprintf("Disk remove action processed: %x.%x\n",
                                disk_cfg->major, disk_cfg->minor);
                        disk = get_disk_super(super,
                                              disk_cfg->major,
                                              disk_cfg->minor);
                        if (disk) {
                                /* store action status */
                                disk->action = DISK_REMOVE;
                                /* remove spare disks only */
                                if (disk->index == -1) {
                                        remove_disk_super(super,
                                                          disk_cfg->major,
                                                          disk_cfg->minor);
                                }
                        }
                        /* release allocate disk structure */
                        __free_imsm_disk(disk_cfg);
                }
        }
        return check_degraded;
}


static int apply_reshape_migration_update(struct imsm_update_reshape_migration *u,
                                                struct intel_super *super,
                                                void ***space_list)
{
        struct intel_dev *id;
        void **tofree = NULL;
        int ret_val = 0;

        dprintf("apply_reshape_migration_update()\n");
        if ((u->subdev < 0) ||
            (u->subdev > 1)) {
                dprintf("imsm: Error: Wrong subdev: %i\n", u->subdev);
                return ret_val;
        }
        if ((space_list == NULL) || (*space_list == NULL)) {
                dprintf("imsm: Error: Memory is not allocated\n");
                return ret_val;
        }

        for (id = super->devlist ; id; id = id->next) {
                if (id->index == (unsigned)u->subdev) {
                        struct imsm_dev *dev = get_imsm_dev(super, u->subdev);
                        struct imsm_map *map;
                        struct imsm_dev *new_dev =
                                (struct imsm_dev *)*space_list;
                        struct imsm_map *migr_map = get_imsm_map(dev, 1);
                        int to_state;
                        struct dl *new_disk;

                        if (new_dev == NULL)
                                return ret_val;
                        *space_list = **space_list;
                        memcpy(new_dev, dev, sizeof_imsm_dev(dev, 0));
                        map = get_imsm_map(new_dev, 0);
                        if (migr_map) {
                                dprintf("imsm: Error: migration in progress");
                                return ret_val;
                        }

                        to_state = map->map_state;
                        if ((u->new_level == 5) && (map->raid_level == 0)) {
                                map->num_members++;
                                /* this should not happen */
                                if (u->new_disks[0] < 0) {
                                        map->failed_disk_num =
                                                map->num_members - 1;
                                        to_state = IMSM_T_STATE_DEGRADED;
                                } else
                                        to_state = IMSM_T_STATE_NORMAL;
                        }
                        migrate(new_dev, super, to_state, MIGR_GEN_MIGR);
                        if (u->new_level > -1)
                                map->raid_level = u->new_level;
                        migr_map = get_imsm_map(new_dev, 1);
                        if ((u->new_level == 5) &&
                            (migr_map->raid_level == 0)) {
                                int ord = map->num_members - 1;
                                migr_map->num_members--;
                                if (u->new_disks[0] < 0)
                                        ord |= IMSM_ORD_REBUILD;
                                set_imsm_ord_tbl_ent(map,
                                                     map->num_members - 1,
                                                     ord);
                        }
                        id->dev = new_dev;
                        tofree = (void **)dev;

                        /* update chunk size
                         */
                        if (u->new_chunksize > 0)
                                map->blocks_per_strip =
                                        __cpu_to_le16(u->new_chunksize * 2);

                        /* add disk
                         */
                        if ((u->new_level != 5) ||
                            (migr_map->raid_level != 0) ||
                            (migr_map->raid_level == map->raid_level))
                                goto skip_disk_add;

                        if (u->new_disks[0] >= 0) {
                                /* use passes spare
                                 */
                                new_disk = get_disk_super(super,
                                                        major(u->new_disks[0]),
                                                        minor(u->new_disks[0]));
                                dprintf("imsm: new disk for reshape is: %i:%i "
                                        "(%p, index = %i)\n",
                                        major(u->new_disks[0]),
                                        minor(u->new_disks[0]),
                                        new_disk, new_disk->index);
                                if (new_disk == NULL)
                                        goto error_disk_add;

                                new_disk->index = map->num_members - 1;
                                /* slot to fill in autolayout
                                 */
                                new_disk->raiddisk = new_disk->index;
                                new_disk->disk.status |= CONFIGURED_DISK;
                                new_disk->disk.status &= ~SPARE_DISK;
                        } else
                                goto error_disk_add;

skip_disk_add:
                        *tofree = *space_list;
                        /* calculate new size
                         */
                        imsm_set_array_size(new_dev);

                        ret_val = 1;
                }
        }

        if (tofree)
                *space_list = tofree;
        return ret_val;

error_disk_add:
        dprintf("Error: imsm: Cannot find disk.\n");
        return ret_val;
}


static int apply_reshape_container_disks_update(struct imsm_update_reshape *u,
                                                struct intel_super *super,
                                                void ***space_list)
{
        struct dl *new_disk;
        struct intel_dev *id;
        int i;
        int delta_disks = u->new_raid_disks - u->old_raid_disks;
        int disk_count = u->old_raid_disks;
        void **tofree = NULL;
        int devices_to_reshape = 1;
        struct imsm_super *mpb = super->anchor;
        int ret_val = 0;
        unsigned int dev_id;

        dprintf("imsm: apply_reshape_container_disks_update()\n");

        /* enable spares to use in array */
        for (i = 0; i < delta_disks; i++) {
                new_disk = get_disk_super(super,
                                          major(u->new_disks[i]),
                                          minor(u->new_disks[i]));
                dprintf("imsm: new disk for reshape is: %i:%i "
                        "(%p, index = %i)\n",
                        major(u->new_disks[i]), minor(u->new_disks[i]),
                        new_disk, new_disk->index);
                if ((new_disk == NULL) ||
                    ((new_disk->index >= 0) &&
                     (new_disk->index < u->old_raid_disks)))
                        goto update_reshape_exit;
                new_disk->index = disk_count++;
                /* slot to fill in autolayout
                 */
                new_disk->raiddisk = new_disk->index;
                new_disk->disk.status |=
                        CONFIGURED_DISK;
                new_disk->disk.status &= ~SPARE_DISK;
        }

        dprintf("imsm: volume set mpb->num_raid_devs = %i\n",
                mpb->num_raid_devs);
        /* manage changes in volume
         */
        for (dev_id = 0; dev_id < mpb->num_raid_devs; dev_id++) {
                void **sp = *space_list;
                struct imsm_dev *newdev;
                struct imsm_map *newmap, *oldmap;

                for (id = super->devlist ; id; id = id->next) {
                        if (id->index == dev_id)
                                break;
                }
                if (id == NULL)
                        break;
                if (!sp)
                        continue;
                *space_list = *sp;
                newdev = (void*)sp;
                /* Copy the dev, but not (all of) the map */
                memcpy(newdev, id->dev, sizeof(*newdev));
                oldmap = get_imsm_map(id->dev, 0);
                newmap = get_imsm_map(newdev, 0);
                /* Copy the current map */
                memcpy(newmap, oldmap, sizeof_imsm_map(oldmap));
                /* update one device only
                 */
                if (devices_to_reshape) {
                        dprintf("imsm: modifying subdev: %i\n",
                                id->index);
                        devices_to_reshape--;
                        newdev->vol.migr_state = 1;
                        newdev->vol.curr_migr_unit = 0;
                        newdev->vol.migr_type = MIGR_GEN_MIGR;
                        newmap->num_members = u->new_raid_disks;
                        for (i = 0; i < delta_disks; i++) {
                                set_imsm_ord_tbl_ent(newmap,
                                                     u->old_raid_disks + i,
                                                     u->old_raid_disks + i);
                        }
                        /* New map is correct, now need to save old map
                         */
                        newmap = get_imsm_map(newdev, 1);
                        memcpy(newmap, oldmap, sizeof_imsm_map(oldmap));

                        imsm_set_array_size(newdev);
                }

                sp = (void **)id->dev;
                id->dev = newdev;
                *sp = tofree;
                tofree = sp;

                /* Clear migration record */
                memset(super->migr_rec, 0, sizeof(struct migr_record));
        }
        if (tofree)
                *space_list = tofree;
        ret_val = 1;

update_reshape_exit:

        return ret_val;
}

static int apply_takeover_update(struct imsm_update_takeover *u,
                                 struct intel_super *super,
                                 void ***space_list)
{
        struct imsm_dev *dev = NULL;
        struct intel_dev *dv;
        struct imsm_dev *dev_new;
        struct imsm_map *map;
        struct dl *dm, *du;
        int i;

        for (dv = super->devlist; dv; dv = dv->next)
                if (dv->index == (unsigned int)u->subarray) {
                        dev = dv->dev;
                        break;
                }

        if (dev == NULL)
                return 0;

        map = get_imsm_map(dev, 0);

        if (u->direction == R10_TO_R0) {
                /* Number of failed disks must be half of initial disk number */
                if (imsm_count_failed(super, dev) != (map->num_members / 2))
                        return 0;

                /* iterate through devices to mark removed disks as spare */
                for (dm = super->disks; dm; dm = dm->next) {
                        if (dm->disk.status & FAILED_DISK) {
                                int idx = dm->index;
                                /* update indexes on the disk list */
/* FIXME this loop-with-the-loop looks wrong,  I'm not convinced
   the index values will end up being correct.... NB */
                                for (du = super->disks; du; du = du->next)
                                        if (du->index > idx)
                                                du->index--;
                                /* mark as spare disk */
                                dm->disk.status = SPARE_DISK;
                                dm->index = -1;
                        }
                }
                /* update map */
                map->num_members = map->num_members / 2;
                map->map_state = IMSM_T_STATE_NORMAL;
                map->num_domains = 1;
                map->raid_level = 0;
                map->failed_disk_num = -1;
        }

        if (u->direction == R0_TO_R10) {
                void **space;
                /* update slots in current disk list */
                for (dm = super->disks; dm; dm = dm->next) {
                        if (dm->index >= 0)
                                dm->index *= 2;
                }
                /* create new *missing* disks */
                for (i = 0; i < map->num_members; i++) {
                        space = *space_list;
                        if (!space)
                                continue;
                        *space_list = *space;
                        du = (void *)space;
                        memcpy(du, super->disks, sizeof(*du));
                        du->fd = -1;
                        du->minor = 0;
                        du->major = 0;
                        du->index = (i * 2) + 1;
                        sprintf((char *)du->disk.serial,
                                " MISSING_%d", du->index);
                        sprintf((char *)du->serial,
                                "MISSING_%d", du->index);
                        du->next = super->missing;
                        super->missing = du;
                }
                /* create new dev and map */
                space = *space_list;
                if (!space)
                        return 0;
                *space_list = *space;
                dev_new = (void *)space;
                memcpy(dev_new, dev, sizeof(*dev));
                /* update new map */
                map = get_imsm_map(dev_new, 0);
                map->num_members = map->num_members * 2;
                map->map_state = IMSM_T_STATE_DEGRADED;
                map->num_domains = 2;
                map->raid_level = 1;
                /* replace dev<->dev_new */
                dv->dev = dev_new;
        }
        /* update disk order table */
        for (du = super->disks; du; du = du->next)
                if (du->index >= 0)
                        set_imsm_ord_tbl_ent(map, du->index, du->index);
        for (du = super->missing; du; du = du->next)
                if (du->index >= 0) {
                        set_imsm_ord_tbl_ent(map, du->index, du->index);
                        mark_missing(dev_new, &du->disk, du->index);
                }

        return 1;
}

static void imsm_process_update(struct supertype *st,
                                struct metadata_update *update)
{
        /**
         * crack open the metadata_update envelope to find the update record
         * update can be one of:
         *    update_reshape_container_disks - all the arrays in the container
         *      are being reshaped to have more devices.  We need to mark
         *      the arrays for general migration and convert selected spares
         *      into active devices.
         *    update_activate_spare - a spare device has replaced a failed
         *      device in an array, update the disk_ord_tbl.  If this disk is
         *      present in all member arrays then also clear the SPARE_DISK
         *      flag
         *    update_create_array
         *    update_kill_array
         *    update_rename_array
         *    update_add_remove_disk
         */
        struct intel_super *super = st->sb;
        struct imsm_super *mpb;
        enum imsm_update_type type = *(enum imsm_update_type *) update->buf;

        /* update requires a larger buf but the allocation failed */
        if (super->next_len && !super->next_buf) {
                super->next_len = 0;
                return;
        }

        if (super->next_buf) {
                memcpy(super->next_buf, super->buf, super->len);
                free(super->buf);
                super->len = super->next_len;
                super->buf = super->next_buf;

                super->next_len = 0;
                super->next_buf = NULL;
        }

        mpb = super->anchor;

        switch (type) {
        case update_takeover: {
                struct imsm_update_takeover *u = (void *)update->buf;
                if (apply_takeover_update(u, super, &update->space_list)) {
                        imsm_update_version_info(super);
                        super->updates_pending++;
                }
                break;
        }

        case update_reshape_container_disks: {
                struct imsm_update_reshape *u = (void *)update->buf;
                if (apply_reshape_container_disks_update(
                            u, super, &update->space_list))
                        super->updates_pending++;
                break;
        }
        case update_reshape_migration: {
                struct imsm_update_reshape_migration *u = (void *)update->buf;
                if (apply_reshape_migration_update(
                            u, super, &update->space_list))
                        super->updates_pending++;
                break;
        }
        case update_activate_spare: {
                struct imsm_update_activate_spare *u = (void *) update->buf; 
                struct imsm_dev *dev = get_imsm_dev(super, u->array);
                struct imsm_map *map = get_imsm_map(dev, 0);
                struct imsm_map *migr_map;
                struct active_array *a;
                struct imsm_disk *disk;
                __u8 to_state;
                struct dl *dl;
                unsigned int found;
                int failed;
                int victim = get_imsm_disk_idx(dev, u->slot, -1);
                int i;

                for (dl = super->disks; dl; dl = dl->next)
                        if (dl == u->dl)
                                break;

                if (!dl) {
                        fprintf(stderr, "error: imsm_activate_spare passed "
                                "an unknown disk (index: %d)\n",
                                u->dl->index);
                        return;
                }

                super->updates_pending++;
                /* count failures (excluding rebuilds and the victim)
                 * to determine map[0] state
                 */
                failed = 0;
                for (i = 0; i < map->num_members; i++) {
                        if (i == u->slot)
                                continue;
                        disk = get_imsm_disk(super,
                                             get_imsm_disk_idx(dev, i, -1));
                        if (!disk || is_failed(disk))
                                failed++;
                }

                /* adding a pristine spare, assign a new index */
                if (dl->index < 0) {
                        dl->index = super->anchor->num_disks;
                        super->anchor->num_disks++;
                }
                disk = &dl->disk;
                disk->status |= CONFIGURED_DISK;
                disk->status &= ~SPARE_DISK;

                /* mark rebuild */
                to_state = imsm_check_degraded(super, dev, failed);
                map->map_state = IMSM_T_STATE_DEGRADED;
                migrate(dev, super, to_state, MIGR_REBUILD);
                migr_map = get_imsm_map(dev, 1);
                set_imsm_ord_tbl_ent(map, u->slot, dl->index);
                set_imsm_ord_tbl_ent(migr_map, u->slot, dl->index | IMSM_ORD_REBUILD);

                /* update the family_num to mark a new container
                 * generation, being careful to record the existing
                 * family_num in orig_family_num to clean up after
                 * earlier mdadm versions that neglected to set it.
                 */
                if (mpb->orig_family_num == 0)
                        mpb->orig_family_num = mpb->family_num;
                mpb->family_num += super->random;

                /* count arrays using the victim in the metadata */
                found = 0;
                for (a = st->arrays; a ; a = a->next) {
                        dev = get_imsm_dev(super, a->info.container_member);
                        map = get_imsm_map(dev, 0);

                        if (get_imsm_disk_slot(map, victim) >= 0)
                                found++;
                }

                /* delete the victim if it is no longer being
                 * utilized anywhere
                 */
                if (!found) {
                        struct dl **dlp;

                        /* We know that 'manager' isn't touching anything,
                         * so it is safe to delete
                         */
                        for (dlp = &super->disks; *dlp; dlp = &(*dlp)->next)
                                if ((*dlp)->index == victim)
                                        break;

                        /* victim may be on the missing list */
                        if (!*dlp)
                                for (dlp = &super->missing; *dlp; dlp = &(*dlp)->next)
                                        if ((*dlp)->index == victim)
                                                break;
                        imsm_delete(super, dlp, victim);
                }
                break;
        }
        case update_create_array: {
                /* someone wants to create a new array, we need to be aware of
                 * a few races/collisions:
                 * 1/ 'Create' called by two separate instances of mdadm
                 * 2/ 'Create' versus 'activate_spare': mdadm has chosen
                 *     devices that have since been assimilated via
                 *     activate_spare.
                 * In the event this update can not be carried out mdadm will
                 * (FIX ME) notice that its update did not take hold.
                 */
                struct imsm_update_create_array *u = (void *) update->buf;
                struct intel_dev *dv;
                struct imsm_dev *dev;
                struct imsm_map *map, *new_map;
                unsigned long long start, end;
                unsigned long long new_start, new_end;
                int i;
                struct disk_info *inf;
                struct dl *dl;

                /* handle racing creates: first come first serve */
                if (u->dev_idx < mpb->num_raid_devs) {
                        dprintf("%s: subarray %d already defined\n",
                                __func__, u->dev_idx);
                        goto create_error;
                }

                /* check update is next in sequence */
                if (u->dev_idx != mpb->num_raid_devs) {
                        dprintf("%s: can not create array %d expected index %d\n",
                                __func__, u->dev_idx, mpb->num_raid_devs);
                        goto create_error;
                }

                new_map = get_imsm_map(&u->dev, 0);
                new_start = __le32_to_cpu(new_map->pba_of_lba0);
                new_end = new_start + __le32_to_cpu(new_map->blocks_per_member);
                inf = get_disk_info(u);

                /* handle activate_spare versus create race:
                 * check to make sure that overlapping arrays do not include
                 * overalpping disks
                 */
                for (i = 0; i < mpb->num_raid_devs; i++) {
                        dev = get_imsm_dev(super, i);
                        map = get_imsm_map(dev, 0);
                        start = __le32_to_cpu(map->pba_of_lba0);
                        end = start + __le32_to_cpu(map->blocks_per_member);
                        if ((new_start >= start && new_start <= end) ||
                            (start >= new_start && start <= new_end))
                                /* overlap */;
                        else
                                continue;

                        if (disks_overlap(super, i, u)) {
                                dprintf("%s: arrays overlap\n", __func__);
                                goto create_error;
                        }
                }

                /* check that prepare update was successful */
                if (!update->space) {
                        dprintf("%s: prepare update failed\n", __func__);
                        goto create_error;
                }

                /* check that all disks are still active before committing
                 * changes.  FIXME: could we instead handle this by creating a
                 * degraded array?  That's probably not what the user expects,
                 * so better to drop this update on the floor.
                 */
                for (i = 0; i < new_map->num_members; i++) {
                        dl = serial_to_dl(inf[i].serial, super);
                        if (!dl) {
                                dprintf("%s: disk disappeared\n", __func__);
                                goto create_error;
                        }
                }

                super->updates_pending++;

                /* convert spares to members and fixup ord_tbl */
                for (i = 0; i < new_map->num_members; i++) {
                        dl = serial_to_dl(inf[i].serial, super);
                        if (dl->index == -1) {
                                dl->index = mpb->num_disks;
                                mpb->num_disks++;
                                dl->disk.status |= CONFIGURED_DISK;
                                dl->disk.status &= ~SPARE_DISK;
                        }
                        set_imsm_ord_tbl_ent(new_map, i, dl->index);
                }

                dv = update->space;
                dev = dv->dev;
                update->space = NULL;
                imsm_copy_dev(dev, &u->dev);
                dv->index = u->dev_idx;
                dv->next = super->devlist;
                super->devlist = dv;
                mpb->num_raid_devs++;

                imsm_update_version_info(super);
                break;
 create_error:
                /* mdmon knows how to release update->space, but not
                 * ((struct intel_dev *) update->space)->dev
                 */
                if (update->space) {
                        dv = update->space;
                        free(dv->dev);
                }
                break;
        }
        case update_kill_array: {
                struct imsm_update_kill_array *u = (void *) update->buf;
                int victim = u->dev_idx;
                struct active_array *a;
                struct intel_dev **dp;
                struct imsm_dev *dev;

                /* sanity check that we are not affecting the uuid of
                 * active arrays, or deleting an active array
                 *
                 * FIXME when immutable ids are available, but note that
                 * we'll also need to fixup the invalidated/active
                 * subarray indexes in mdstat
                 */
                for (a = st->arrays; a; a = a->next)
                        if (a->info.container_member >= victim)
                                break;
                /* by definition if mdmon is running at least one array
                 * is active in the container, so checking
                 * mpb->num_raid_devs is just extra paranoia
                 */
                dev = get_imsm_dev(super, victim);
                if (a || !dev || mpb->num_raid_devs == 1) {
                        dprintf("failed to delete subarray-%d\n", victim);
                        break;
                }

                for (dp = &super->devlist; *dp;)
                        if ((*dp)->index == (unsigned)super->current_vol) {
                                *dp = (*dp)->next;
                        } else {
                                if ((*dp)->index > (unsigned)victim)
                                        (*dp)->index--;
                                dp = &(*dp)->next;
                        }
                mpb->num_raid_devs--;
                super->updates_pending++;
                break;
        }
        case update_rename_array: {
                struct imsm_update_rename_array *u = (void *) update->buf;
                char name[MAX_RAID_SERIAL_LEN+1];
                int target = u->dev_idx;
                struct active_array *a;
                struct imsm_dev *dev;

                /* sanity check that we are not affecting the uuid of
                 * an active array
                 */
                snprintf(name, MAX_RAID_SERIAL_LEN, "%s", (char *) u->name);
                name[MAX_RAID_SERIAL_LEN] = '\0';
                for (a = st->arrays; a; a = a->next)
                        if (a->info.container_member == target)
                                break;
                dev = get_imsm_dev(super, u->dev_idx);
                if (a || !dev || !check_name(super, name, 1)) {
                        dprintf("failed to rename subarray-%d\n", target);
                        break;
                }

                snprintf((char *) dev->volume, MAX_RAID_SERIAL_LEN, "%s", name);
                super->updates_pending++;
                break;
        }
        case update_add_remove_disk: {
                /* we may be able to repair some arrays if disks are
                 * being added, check teh status of add_remove_disk
                 * if discs has been added.
                 */
                if (add_remove_disk_update(super)) {
                        struct active_array *a;

                        super->updates_pending++;
                        for (a = st->arrays; a; a = a->next)
                                a->check_degraded = 1;
                }
                break;
        }
        default:
                fprintf(stderr, "error: unsuported process update type:"
                        "(type: %d)\n", type);
        }
}

static struct mdinfo *get_spares_for_grow(struct supertype *st);

static void imsm_prepare_update(struct supertype *st,
                                struct metadata_update *update)
{
        /**
         * Allocate space to hold new disk entries, raid-device entries or a new
         * mpb if necessary.  The manager synchronously waits for updates to
         * complete in the monitor, so new mpb buffers allocated here can be
         * integrated by the monitor thread without worrying about live pointers
         * in the manager thread.
         */
        enum imsm_update_type type = *(enum imsm_update_type *) update->buf;
        struct intel_super *super = st->sb;
        struct imsm_super *mpb = super->anchor;
        size_t buf_len;
        size_t len = 0;

        switch (type) {
        case update_takeover: {
                struct imsm_update_takeover *u = (void *)update->buf;
                if (u->direction == R0_TO_R10) {
                        void **tail = (void **)&update->space_list;
                        struct imsm_dev *dev = get_imsm_dev(super, u->subarray);
                        struct imsm_map *map = get_imsm_map(dev, 0);
                        int num_members = map->num_members;
                        void *space;
                        int size, i;
                        int err = 0;
                        /* allocate memory for added disks */
                        for (i = 0; i < num_members; i++) {
                                size = sizeof(struct dl);
                                space = malloc(size);
                                if (!space) {
                                        err++;
                                        break;
                                }
                                *tail = space;
                                tail = space;
                                *tail = NULL;
                        }
                        /* allocate memory for new device */
                        size = sizeof_imsm_dev(super->devlist->dev, 0) +
                                (num_members * sizeof(__u32));
                        space = malloc(size);
                        if (!space)
                                err++;
                        else {
                                *tail = space;
                                tail = space;
                                *tail = NULL;
                        }
                        if (!err) {
                                len = disks_to_mpb_size(num_members * 2);
                        } else {
                                /* if allocation didn't success, free buffer */
                                while (update->space_list) {
                                        void **sp = update->space_list;
                                        update->space_list = *sp;
                                        free(sp);
                                }
                        }
                }

                break;
        }
        case update_reshape_container_disks: {
                /* Every raid device in the container is about to
                 * gain some more devices, and we will enter a
                 * reconfiguration.
                 * So each 'imsm_map' will be bigger, and the imsm_vol
                 * will now hold 2 of them.
                 * Thus we need new 'struct imsm_dev' allocations sized
                 * as sizeof_imsm_dev but with more devices in both maps.
                 */
                struct imsm_update_reshape *u = (void *)update->buf;
                struct intel_dev *dl;
                void **space_tail = (void**)&update->space_list;

                dprintf("imsm: imsm_prepare_update() for update_reshape\n");

                for (dl = super->devlist; dl; dl = dl->next) {
                        int size = sizeof_imsm_dev(dl->dev, 1);
                        void *s;
                        if (u->new_raid_disks > u->old_raid_disks)
                                size += sizeof(__u32)*2*
                                        (u->new_raid_disks - u->old_raid_disks);
                        s = malloc(size);
                        if (!s)
                                break;
                        *space_tail = s;
                        space_tail = s;
                        *space_tail = NULL;
                }

                len = disks_to_mpb_size(u->new_raid_disks);
                dprintf("New anchor length is %llu\n", (unsigned long long)len);
                break;
        }
        case update_reshape_migration: {
                /* for migration level 0->5 we need to add disks
                 * so the same as for container operation we will copy
                 * device to the bigger location.
                 * in memory prepared device and new disk area are prepared
                 * for usage in process update
                 */
                struct imsm_update_reshape_migration *u = (void *)update->buf;
                struct intel_dev *id;
                void **space_tail = (void **)&update->space_list;
                int size;
                void *s;
                int current_level = -1;

                dprintf("imsm: imsm_prepare_update() for update_reshape\n");

                /* add space for bigger array in update
                 */
                for (id = super->devlist; id; id = id->next) {
                        if (id->index == (unsigned)u->subdev) {
                                size = sizeof_imsm_dev(id->dev, 1);
                                if (u->new_raid_disks > u->old_raid_disks)
                                        size += sizeof(__u32)*2*
                                        (u->new_raid_disks - u->old_raid_disks);
                                s = malloc(size);
                                if (!s)
                                        break;
                                *space_tail = s;
                                space_tail = s;
                                *space_tail = NULL;
                                break;
                        }
                }
                if (update->space_list == NULL)
                        break;

                /* add space for disk in update
                 */
                size = sizeof(struct dl);
                s = malloc(size);
                if (!s) {
                        free(update->space_list);
                        update->space_list = NULL;
                        break;
                }
                *space_tail = s;
                space_tail = s;
                *space_tail = NULL;

                /* add spare device to update
                 */
                for (id = super->devlist ; id; id = id->next)
                        if (id->index == (unsigned)u->subdev) {
                                struct imsm_dev *dev;
                                struct imsm_map *map;

                                dev = get_imsm_dev(super, u->subdev);
                                map = get_imsm_map(dev, 0);
                                current_level = map->raid_level;
                                break;
                        }
                if ((u->new_level == 5) && (u->new_level != current_level)) {
                        struct mdinfo *spares;

                        spares = get_spares_for_grow(st);
                        if (spares) {
                                struct dl *dl;
                                struct mdinfo *dev;

                                dev = spares->devs;
                                if (dev) {
                                        u->new_disks[0] =
                                                makedev(dev->disk.major,
                                                        dev->disk.minor);
                                        dl = get_disk_super(super,
                                                            dev->disk.major,
                                                            dev->disk.minor);
                                        dl->index = u->old_raid_disks;
                                        dev = dev->next;
                                }
                                sysfs_free(spares);
                        }
                }
                len = disks_to_mpb_size(u->new_raid_disks);
                dprintf("New anchor length is %llu\n", (unsigned long long)len);
                break;
        }
        case update_create_array: {
                struct imsm_update_create_array *u = (void *) update->buf;
                struct intel_dev *dv;
                struct imsm_dev *dev = &u->dev;
                struct imsm_map *map = get_imsm_map(dev, 0);
                struct dl *dl;
                struct disk_info *inf;
                int i;
                int activate = 0;

                inf = get_disk_info(u);
                len = sizeof_imsm_dev(dev, 1);
                /* allocate a new super->devlist entry */
                dv = malloc(sizeof(*dv));
                if (dv) {
                        dv->dev = malloc(len);
                        if (dv->dev)
                                update->space = dv;
                        else {
                                free(dv);
                                update->space = NULL;
                        }
                }

                /* count how many spares will be converted to members */
                for (i = 0; i < map->num_members; i++) {
                        dl = serial_to_dl(inf[i].serial, super);
                        if (!dl) {
                                /* hmm maybe it failed?, nothing we can do about
                                 * it here
                                 */
                                continue;
                        }
                        if (count_memberships(dl, super) == 0)
                                activate++;
                }
                len += activate * sizeof(struct imsm_disk);
                break;
        default:
                break;
        }
        }

        /* check if we need a larger metadata buffer */
        if (super->next_buf)
                buf_len = super->next_len;
        else
                buf_len = super->len;

        if (__le32_to_cpu(mpb->mpb_size) + len > buf_len) {
                /* ok we need a larger buf than what is currently allocated
                 * if this allocation fails process_update will notice that
                 * ->next_len is set and ->next_buf is NULL
                 */
                buf_len = ROUND_UP(__le32_to_cpu(mpb->mpb_size) + len, 512);
                if (super->next_buf)
                        free(super->next_buf);

                super->next_len = buf_len;
                if (posix_memalign(&super->next_buf, 512, buf_len) == 0)
                        memset(super->next_buf, 0, buf_len);
                else
                        super->next_buf = NULL;
        }
}

/* must be called while manager is quiesced */
static void imsm_delete(struct intel_super *super, struct dl **dlp, unsigned index)
{
        struct imsm_super *mpb = super->anchor;
        struct dl *iter;
        struct imsm_dev *dev;
        struct imsm_map *map;
        int i, j, num_members;
        __u32 ord;

        dprintf("%s: deleting device[%d] from imsm_super\n",
                __func__, index);

        /* shift all indexes down one */
        for (iter = super->disks; iter; iter = iter->next)
                if (iter->index > (int)index)
                        iter->index--;
        for (iter = super->missing; iter; iter = iter->next)
                if (iter->index > (int)index)
                        iter->index--;

        for (i = 0; i < mpb->num_raid_devs; i++) {
                dev = get_imsm_dev(super, i);
                map = get_imsm_map(dev, 0);
                num_members = map->num_members;
                for (j = 0; j < num_members; j++) {
                        /* update ord entries being careful not to propagate
                         * ord-flags to the first map
                         */
                        ord = get_imsm_ord_tbl_ent(dev, j, -1);

                        if (ord_to_idx(ord) <= index)
                                continue;

                        map = get_imsm_map(dev, 0);
                        set_imsm_ord_tbl_ent(map, j, ord_to_idx(ord - 1));
                        map = get_imsm_map(dev, 1);
                        if (map)
                                set_imsm_ord_tbl_ent(map, j, ord - 1);
                }
        }

        mpb->num_disks--;
        super->updates_pending++;
        if (*dlp) {
                struct dl *dl = *dlp;

                *dlp = (*dlp)->next;
                __free_imsm_disk(dl);
        }
}

/*******************************************************************************
 * Function:    open_backup_targets
 * Description: Function opens file descriptors for all devices given in
 *              info->devs
 * Parameters:
 *      info            : general array info
 *      raid_disks      : number of disks
 *      raid_fds        : table of device's file descriptors
 * Returns:
 *       0 : success
 *      -1 : fail
 ******************************************************************************/
int open_backup_targets(struct mdinfo *info, int raid_disks, int *raid_fds)
{
        struct mdinfo *sd;

        for (sd = info->devs ; sd ; sd = sd->next) {
                char *dn;

                if (sd->disk.state & (1<<MD_DISK_FAULTY)) {
                        dprintf("disk is faulty!!\n");
                        continue;
                }

                if ((sd->disk.raid_disk >= raid_disks) ||
                    (sd->disk.raid_disk < 0))
                        continue;

                dn = map_dev(sd->disk.major,
                             sd->disk.minor, 1);
                raid_fds[sd->disk.raid_disk] = dev_open(dn, O_RDWR);
                if (raid_fds[sd->disk.raid_disk] < 0) {
                        fprintf(stderr, "cannot open component\n");
                        return -1;
                }
        }
        return 0;
}

/*******************************************************************************
 * Function:    init_migr_record_imsm
 * Description: Function inits imsm migration record
 * Parameters:
 *      super   : imsm internal array info
 *      dev     : device under migration
 *      info    : general array info to find the smallest device
 * Returns:
 *      none
 ******************************************************************************/
void init_migr_record_imsm(struct supertype *st, struct imsm_dev *dev,
                           struct mdinfo *info)
{
        struct intel_super *super = st->sb;
        struct migr_record *migr_rec = super->migr_rec;
        int new_data_disks;
        unsigned long long dsize, dev_sectors;
        long long unsigned min_dev_sectors = -1LLU;
        struct mdinfo *sd;
        char nm[30];
        int fd;
        struct imsm_map *map_dest = get_imsm_map(dev, 0);
        struct imsm_map *map_src = get_imsm_map(dev, 1);
        unsigned long long num_migr_units;

        unsigned long long array_blocks =
                (((unsigned long long)__le32_to_cpu(dev->size_high)) << 32) +
                __le32_to_cpu(dev->size_low);

        memset(migr_rec, 0, sizeof(struct migr_record));
        migr_rec->family_num = __cpu_to_le32(super->anchor->family_num);

        /* only ascending reshape supported now */
        migr_rec->ascending_migr = __cpu_to_le32(1);

        migr_rec->dest_depth_per_unit = GEN_MIGR_AREA_SIZE /
                max(map_dest->blocks_per_strip, map_src->blocks_per_strip);
        migr_rec->dest_depth_per_unit *= map_dest->blocks_per_strip;
        new_data_disks = imsm_num_data_members(dev, 0);
        migr_rec->blocks_per_unit =
                __cpu_to_le32(migr_rec->dest_depth_per_unit * new_data_disks);
        migr_rec->dest_depth_per_unit =
                __cpu_to_le32(migr_rec->dest_depth_per_unit);

        num_migr_units =
                array_blocks / __le32_to_cpu(migr_rec->blocks_per_unit);

        if (array_blocks % __le32_to_cpu(migr_rec->blocks_per_unit))
                num_migr_units++;
        migr_rec->num_migr_units = __cpu_to_le32(num_migr_units);

        migr_rec->post_migr_vol_cap =  dev->size_low;
        migr_rec->post_migr_vol_cap_hi = dev->size_high;


        /* Find the smallest dev */
        for (sd = info->devs ; sd ; sd = sd->next) {
                sprintf(nm, "%d:%d", sd->disk.major, sd->disk.minor);
                fd = dev_open(nm, O_RDONLY);
                if (fd < 0)
                        continue;
                get_dev_size(fd, NULL, &dsize);
                dev_sectors = dsize / 512;
                if (dev_sectors < min_dev_sectors)
                        min_dev_sectors = dev_sectors;
                close(fd);
        }
        migr_rec->ckpt_area_pba = __cpu_to_le32(min_dev_sectors -
                                        RAID_DISK_RESERVED_BLOCKS_IMSM_HI);

        write_imsm_migr_rec(st);

        return;
}

/*******************************************************************************
 * Function:    save_backup_imsm
 * Description: Function saves critical data stripes to Migration Copy Area
 *              and updates the current migration unit status.
 *              Use restore_stripes() to form a destination stripe,
 *              and to write it to the Copy Area.
 * Parameters:
 *      st              : supertype information
 *      info            : general array info
 *      buf             : input buffer
 *      write_offset    : address of data to backup
 *      length          : length of data to backup (blocks_per_unit)
 * Returns:
 *       0 : success
 *,     -1 : fail
 ******************************************************************************/
int save_backup_imsm(struct supertype *st,
                     struct imsm_dev *dev,
                     struct mdinfo *info,
                     void *buf,
                     int new_data,
                     int length)
{
        int rv = -1;
        struct intel_super *super = st->sb;
        unsigned long long *target_offsets = NULL;
        int *targets = NULL;
        int i;
        struct imsm_map *map_dest = get_imsm_map(dev, 0);
        int new_disks = map_dest->num_members;

        targets = malloc(new_disks * sizeof(int));
        if (!targets)
                goto abort;

        target_offsets = malloc(new_disks * sizeof(unsigned long long));
        if (!target_offsets)
                goto abort;

        for (i = 0; i < new_disks; i++) {
                targets[i] = -1;
                target_offsets[i] = (unsigned long long)
                  __le32_to_cpu(super->migr_rec->ckpt_area_pba) * 512;
        }

        if (open_backup_targets(info, new_disks, targets))
                goto abort;

        if (restore_stripes(targets, /* list of dest devices */
                            target_offsets, /* migration record offsets */
                            new_disks,
                            info->new_chunk,
                            info->new_level,
                            info->new_layout,
                            -1,         /* source backup file descriptor */
                            0,          /* input buf offset
                                         * always 0 buf is already offset */
                            0,
                            length,
                            buf) != 0) {
                fprintf(stderr, Name ": Error restoring stripes\n");
                goto abort;
        }

        rv = 0;

abort:
        if (targets) {
                for (i = 0; i < new_disks; i++)
                        if (targets[i] >= 0)
                                close(targets[i]);
                free(targets);
        }
        free(target_offsets);

        return rv;
}

/*******************************************************************************
 * Function:    save_checkpoint_imsm
 * Description: Function called for current unit status update
 *              in the migration record. It writes it to disk.
 * Parameters:
 *      super   : imsm internal array info
 *      info    : general array info
 * Returns:
 *      0: success
 *      1: failure
 ******************************************************************************/
int save_checkpoint_imsm(struct supertype *st, struct mdinfo *info, int state)
{
        struct intel_super *super = st->sb;
        load_imsm_migr_rec(super, info);
        if (__le32_to_cpu(super->migr_rec->blocks_per_unit) == 0) {
                dprintf("ERROR: blocks_per_unit = 0!!!\n");
                return 1;
        }

        super->migr_rec->curr_migr_unit =
          __cpu_to_le32(info->reshape_progress /
                        __le32_to_cpu(super->migr_rec->blocks_per_unit));
        super->migr_rec->rec_status = __cpu_to_le32(state);
        super->migr_rec->dest_1st_member_lba =
          __cpu_to_le32((__le32_to_cpu(super->migr_rec->curr_migr_unit))
                        * __le32_to_cpu(super->migr_rec->dest_depth_per_unit));
        if (write_imsm_migr_rec(st) < 0) {
                dprintf("imsm: Cannot write migration record "
                        "outside backup area\n");
                return 1;
        }

        return 0;
}

static __u64 blocks_per_migr_unit(struct intel_super *super,
                                  struct imsm_dev *dev);

/*******************************************************************************
 * Function:    recover_backup_imsm
 * Description: Function recovers critical data from the Migration Copy Area
 *              while assembling an array.
 * Parameters:
 *      super   : imsm internal array info
 *      info    : general array info
 * Returns:
 *      0 : success (or there is no data to recover)
 *      1 : fail
 ******************************************************************************/
int recover_backup_imsm(struct supertype *st, struct mdinfo *info)
{
        struct intel_super *super = st->sb;
        struct migr_record *migr_rec = super->migr_rec;
        struct imsm_map *map_dest = NULL;
        struct intel_dev *id = NULL;
        unsigned long long read_offset;
        unsigned long long write_offset;
        unsigned unit_len;
        int *targets = NULL;
        int new_disks, i, err;
        char *buf = NULL;
        int retval = 1;
        unsigned long curr_migr_unit = __le32_to_cpu(migr_rec->curr_migr_unit);
        unsigned long num_migr_units = __le32_to_cpu(migr_rec->num_migr_units);
        int ascending = __le32_to_cpu(migr_rec->ascending_migr);
        char buffer[20];

        err = sysfs_get_str(info, NULL, "array_state", (char *)buffer, 20);
        if (err < 1)
                return 1;

        /* recover data only during assemblation */
        if (strncmp(buffer, "inactive", 8) != 0)
                return 0;
        /* no data to recover */
        if (__le32_to_cpu(migr_rec->rec_status) == UNIT_SRC_NORMAL)
                return 0;
        if (curr_migr_unit >= num_migr_units)
                return 1;

        /* find device during reshape */
        for (id = super->devlist; id; id = id->next)
                if (is_gen_migration(id->dev))
                        break;
        if (id == NULL)
                return 1;

        map_dest = get_imsm_map(id->dev, 0);
        new_disks = map_dest->num_members;

        read_offset = (unsigned long long)
                        __le32_to_cpu(migr_rec->ckpt_area_pba) * 512;

        write_offset = ((unsigned long long)
                        __le32_to_cpu(migr_rec->dest_1st_member_lba) +
                        info->data_offset) * 512;

        unit_len = __le32_to_cpu(migr_rec->dest_depth_per_unit) * 512;
        if (posix_memalign((void **)&buf, 512, unit_len) != 0)
                goto abort;
        targets = malloc(new_disks * sizeof(int));
        if (!targets)
                goto abort;

        open_backup_targets(info, new_disks, targets);

        for (i = 0; i < new_disks; i++) {
                if (lseek64(targets[i], read_offset, SEEK_SET) < 0) {
                        fprintf(stderr,
                                Name ": Cannot seek to block: %s\n",
                                strerror(errno));
                        goto abort;
                }
                if (read(targets[i], buf, unit_len) != unit_len) {
                        fprintf(stderr,
                                Name ": Cannot read copy area block: %s\n",
                                strerror(errno));
                        goto abort;
                }
                if (lseek64(targets[i], write_offset, SEEK_SET) < 0) {
                        fprintf(stderr,
                                Name ": Cannot seek to block: %s\n",
                                strerror(errno));
                        goto abort;
                }
                if (write(targets[i], buf, unit_len) != unit_len) {
                        fprintf(stderr,
                                Name ": Cannot restore block: %s\n",
                                strerror(errno));
                        goto abort;
                }
        }

        if (ascending && curr_migr_unit < (num_migr_units-1))
                curr_migr_unit++;

        migr_rec->curr_migr_unit = __le32_to_cpu(curr_migr_unit);
        super->migr_rec->rec_status = __cpu_to_le32(UNIT_SRC_NORMAL);
        if (write_imsm_migr_rec(st) == 0) {
                __u64 blocks_per_unit = blocks_per_migr_unit(super, id->dev);
                info->reshape_progress = curr_migr_unit * blocks_per_unit;
                retval = 0;
        }

abort:
        if (targets) {
                for (i = 0; i < new_disks; i++)
                        if (targets[i])
                                close(targets[i]);
                free(targets);
        }
        free(buf);
        return retval;
}

static char disk_by_path[] = "/dev/disk/by-path/";

static const char *imsm_get_disk_controller_domain(const char *path)
{
        char disk_path[PATH_MAX];
        char *drv=NULL;
        struct stat st;

        strncpy(disk_path, disk_by_path, PATH_MAX - 1);
        strncat(disk_path, path, PATH_MAX - strlen(disk_path) - 1);
        if (stat(disk_path, &st) == 0) {
                struct sys_dev* hba;
                char *path=NULL;

                path = devt_to_devpath(st.st_rdev);
                if (path == NULL)
                        return "unknown";
                hba = find_disk_attached_hba(-1, path);
                if (hba && hba->type == SYS_DEV_SAS)
                        drv = "isci";
                else if (hba && hba->type == SYS_DEV_SATA)
                        drv = "ahci";
                else 
                        drv = "unknown";
                dprintf("path: %s hba: %s attached: %s\n",
                        path, (hba) ? hba->path : "NULL", drv);
                free(path);
                if (hba)
                        free_sys_dev(&hba);
        }
        return drv;
}

static int imsm_find_array_minor_by_subdev(int subdev, int container, int *minor)
{
        char subdev_name[20];
        struct mdstat_ent *mdstat;

        sprintf(subdev_name, "%d", subdev);
        mdstat = mdstat_by_subdev(subdev_name, container);
        if (!mdstat)
                return -1;

        *minor = mdstat->devnum;
        free_mdstat(mdstat);
        return 0;
}

static int imsm_reshape_is_allowed_on_container(struct supertype *st,
                                                struct geo_params *geo,
                                                int *old_raid_disks)
{
        /* currently we only support increasing the number of devices
         * for a container.  This increases the number of device for each
         * member array.  They must all be RAID0 or RAID5.
         */
        int ret_val = 0;
        struct mdinfo *info, *member;
        int devices_that_can_grow = 0;

        dprintf("imsm: imsm_reshape_is_allowed_on_container(ENTER): "
                "st->devnum = (%i)\n",
                st->devnum);

        if (geo->size != -1 ||
            geo->level != UnSet ||
            geo->layout != UnSet ||
            geo->chunksize != 0 ||
            geo->raid_disks == UnSet) {
                dprintf("imsm: Container operation is allowed for "
                        "raid disks number change only.\n");
                return ret_val;
        }

        info = container_content_imsm(st, NULL);
        for (member = info; member; member = member->next) {
                int result;
                int minor;

                dprintf("imsm: checking device_num: %i\n",
                        member->container_member);

                if (geo->raid_disks <= member->array.raid_disks) {
                        /* we work on container for Online Capacity Expansion
                         * only so raid_disks has to grow
                         */
                        dprintf("imsm: for container operation raid disks "
                                "increase is required\n");
                        break;
                }

                if ((info->array.level != 0) &&
                    (info->array.level != 5)) {
                        /* we cannot use this container with other raid level
                         */
                        dprintf("imsm: for container operation wrong"
                                " raid level (%i) detected\n",
                                info->array.level);
                        break;
                } else {
                        /* check for platform support
                         * for this raid level configuration
                         */
                        struct intel_super *super = st->sb;
                        if (!is_raid_level_supported(super->orom,
                                                     member->array.level,
                                                     geo->raid_disks)) {
                                dprintf("platform does not support raid%d with"
                                        " %d disk%s\n",
                                         info->array.level,
                                         geo->raid_disks,
                                         geo->raid_disks > 1 ? "s" : "");
                                break;
                        }
                        /* check if component size is aligned to chunk size
                         */
                        if (info->component_size %
                            (info->array.chunk_size/512)) {
                                dprintf("Component size is not aligned to "
                                        "chunk size\n");
                                break;
                        }
                }

                if (*old_raid_disks &&
                    info->array.raid_disks != *old_raid_disks)
                        break;
                *old_raid_disks = info->array.raid_disks;

                /* All raid5 and raid0 volumes in container
                 * have to be ready for Online Capacity Expansion
                 * so they need to be assembled.  We have already
                 * checked that no recovery etc is happening.
                 */
                result = imsm_find_array_minor_by_subdev(member->container_member,
                                                         st->container_dev,
                                                         &minor);
                if (result < 0) {
                        dprintf("imsm: cannot find array\n");
                        break;
                }
                devices_that_can_grow++;
        }
        sysfs_free(info);
        if (!member && devices_that_can_grow)
                ret_val = 1;

        if (ret_val)
                dprintf("\tContainer operation allowed\n");
        else
                dprintf("\tError: %i\n", ret_val);

        return ret_val;
}

/* Function: get_spares_for_grow
 * Description: Allocates memory and creates list of spare devices
 *              avaliable in container. Checks if spare drive size is acceptable.
 * Parameters: Pointer to the supertype structure
 * Returns: Pointer to the list of spare devices (mdinfo structure) on success,
 *              NULL if fail
 */
static struct mdinfo *get_spares_for_grow(struct supertype *st)
{
        unsigned long long min_size = min_acceptable_spare_size_imsm(st);
        return container_choose_spares(st, min_size, NULL, NULL, NULL, 0);
}

/******************************************************************************
 * function: imsm_create_metadata_update_for_reshape
 * Function creates update for whole IMSM container.
 *
 ******************************************************************************/
static int imsm_create_metadata_update_for_reshape(
        struct supertype *st,
        struct geo_params *geo,
        int old_raid_disks,
        struct imsm_update_reshape **updatep)
{
        struct intel_super *super = st->sb;
        struct imsm_super *mpb = super->anchor;
        int update_memory_size = 0;
        struct imsm_update_reshape *u = NULL;
        struct mdinfo *spares = NULL;
        int i;
        int delta_disks = 0;
        struct mdinfo *dev;

        dprintf("imsm_update_metadata_for_reshape(enter) raid_disks = %i\n",
                geo->raid_disks);

        delta_disks = geo->raid_disks - old_raid_disks;

        /* size of all update data without anchor */
        update_memory_size = sizeof(struct imsm_update_reshape);

        /* now add space for spare disks that we need to add. */
        update_memory_size += sizeof(u->new_disks[0]) * (delta_disks - 1);

        u = calloc(1, update_memory_size);
        if (u == NULL) {
                dprintf("error: "
                        "cannot get memory for imsm_update_reshape update\n");
                return 0;
        }
        u->type = update_reshape_container_disks;
        u->old_raid_disks = old_raid_disks;
        u->new_raid_disks = geo->raid_disks;

        /* now get spare disks list
         */
        spares = get_spares_for_grow(st);

        if (spares == NULL
            || delta_disks > spares->array.spare_disks) {
                fprintf(stderr, Name ": imsm: ERROR: Cannot get spare devices "
                        "for %s.\n", geo->dev_name);
                goto abort;
        }

        /* we have got spares
         * update disk list in imsm_disk list table in anchor
         */
        dprintf("imsm: %i spares are available.\n\n",
                spares->array.spare_disks);

        dev = spares->devs;
        for (i = 0; i < delta_disks; i++) {
                struct dl *dl;

                if (dev == NULL)
                        break;
                u->new_disks[i] = makedev(dev->disk.major,
                                          dev->disk.minor);
                dl = get_disk_super(super, dev->disk.major, dev->disk.minor);
                dl->index = mpb->num_disks;
                mpb->num_disks++;
                dev = dev->next;
        }

abort:
        /* free spares
         */
        sysfs_free(spares);

        dprintf("imsm: reshape update preparation :");
        if (i == delta_disks) {
                dprintf(" OK\n");
                *updatep = u;
                return update_memory_size;
        }
        free(u);
        dprintf(" Error\n");

        return 0;
}

/******************************************************************************
 * function: imsm_create_metadata_update_for_migration()
 *           Creates update for IMSM array.
 *
 ******************************************************************************/
static int imsm_create_metadata_update_for_migration(
                                        struct supertype *st,
                                        struct geo_params *geo,
                                        struct imsm_update_reshape_migration **updatep)
{
        struct intel_super *super = st->sb;
        int update_memory_size = 0;
        struct imsm_update_reshape_migration *u = NULL;
        struct imsm_dev *dev;
        int previous_level = -1;

        dprintf("imsm_create_metadata_update_for_migration(enter)"
                " New Level = %i\n", geo->level);

        /* size of all update data without anchor */
        update_memory_size = sizeof(struct imsm_update_reshape_migration);

        u = calloc(1, update_memory_size);
        if (u == NULL) {
                dprintf("error: cannot get memory for "
                        "imsm_create_metadata_update_for_migration\n");
                return 0;
        }
        u->type = update_reshape_migration;
        u->subdev = super->current_vol;
        u->new_level = geo->level;
        u->new_layout = geo->layout;
        u->new_raid_disks = u->old_raid_disks = geo->raid_disks;
        u->new_disks[0] = -1;
        u->new_chunksize = -1;

        dev = get_imsm_dev(super, u->subdev);
        if (dev) {
                struct imsm_map *map;

                map = get_imsm_map(dev, 0);
                if (map) {
                        int current_chunk_size =
                                __le16_to_cpu(map->blocks_per_strip) / 2;

                        if (geo->chunksize != current_chunk_size) {
                                u->new_chunksize = geo->chunksize / 1024;
                                dprintf("imsm: "
                                        "chunk size change from %i to %i\n",
                                        current_chunk_size, u->new_chunksize);
                        }
                        previous_level = map->raid_level;
                }
        }
        if ((geo->level == 5) && (previous_level == 0)) {
                struct mdinfo *spares = NULL;

                u->new_raid_disks++;
                spares = get_spares_for_grow(st);
                if ((spares == NULL) || (spares->array.spare_disks < 1)) {
                        free(u);
                        sysfs_free(spares);
                        update_memory_size = 0;
                        dprintf("error: cannot get spare device "
                                "for requested migration");
                        return 0;
                }
                sysfs_free(spares);
        }
        dprintf("imsm: reshape update preparation : OK\n");
        *updatep = u;

        return update_memory_size;
}

static void imsm_update_metadata_locally(struct supertype *st,
                                         void *buf, int len)
{
        struct metadata_update mu;

        mu.buf = buf;
        mu.len = len;
        mu.space = NULL;
        mu.space_list = NULL;
        mu.next = NULL;
        imsm_prepare_update(st, &mu);
        imsm_process_update(st, &mu);

        while (mu.space_list) {
                void **space = mu.space_list;
                mu.space_list = *space;
                free(space);
        }
}

/***************************************************************************
* Function:     imsm_analyze_change
* Description:  Function analyze change for single volume
*               and validate if transition is supported
* Parameters:   Geometry parameters, supertype structure
* Returns:      Operation type code on success, -1 if fail
****************************************************************************/
enum imsm_reshape_type imsm_analyze_change(struct supertype *st,
                                           struct geo_params *geo)
{
        struct mdinfo info;
        int change = -1;
        int check_devs = 0;
        int chunk;

        getinfo_super_imsm_volume(st, &info, NULL);

        if ((geo->level != info.array.level) &&
            (geo->level >= 0) &&
            (geo->level != UnSet)) {
                switch (info.array.level) {
                case 0:
                        if (geo->level == 5) {
                                change = CH_MIGRATION;
                                check_devs = 1;
                        }
                        if (geo->level == 10) {
                                change = CH_TAKEOVER;
                                check_devs = 1;
                        }
                        break;
                case 1:
                        if (geo->level == 0) {
                                change = CH_TAKEOVER;
                                check_devs = 1;
                        }
                        break;
                case 10:
                        if (geo->level == 0) {
                                change = CH_TAKEOVER;
                                check_devs = 1;
                        }
                        break;
                }
                if (change == -1) {
                        fprintf(stderr,
                                Name " Error. Level Migration from %d to %d "
                                "not supported!\n",
                                info.array.level, geo->level);
                        goto analyse_change_exit;
                }
        } else
                geo->level = info.array.level;

        if ((geo->layout != info.array.layout)
            && ((geo->layout != UnSet) && (geo->layout != -1))) {
                change = CH_MIGRATION;
                if ((info.array.layout == 0)
                    && (info.array.level == 5)
                    && (geo->layout == 5)) {
                        /* reshape 5 -> 4 */
                } else if ((info.array.layout == 5)
                           && (info.array.level == 5)
                           && (geo->layout == 0)) {
                        /* reshape 4 -> 5 */
                        geo->layout = 0;
                        geo->level = 5;
                } else {
                        fprintf(stderr,
                                Name " Error. Layout Migration from %d to %d "
                                "not supported!\n",
                                info.array.layout, geo->layout);
                        change = -1;
                        goto analyse_change_exit;
                }
        } else
                geo->layout = info.array.layout;

        if ((geo->chunksize > 0) && (geo->chunksize != UnSet)
            && (geo->chunksize != info.array.chunk_size))
                change = CH_MIGRATION;
        else
                geo->chunksize = info.array.chunk_size;

        chunk = geo->chunksize / 1024;
        if (!validate_geometry_imsm(st,
                                    geo->level,
                                    geo->layout,
                                    geo->raid_disks,
                                    &chunk,
                                    geo->size,
                                    0, 0, 1))
                change = -1;

        if (check_devs) {
                struct intel_super *super = st->sb;
                struct imsm_super *mpb = super->anchor;

                if (mpb->num_raid_devs > 1) {
                        fprintf(stderr,
                                Name " Error. Cannot perform operation on %s"
                                "- for this operation it MUST be single "
                                "array in container\n",
                                geo->dev_name);
                        change = -1;
                }
        }

analyse_change_exit:

        return change;
}

int imsm_takeover(struct supertype *st, struct geo_params *geo)
{
        struct intel_super *super = st->sb;
        struct imsm_update_takeover *u;

        u = malloc(sizeof(struct imsm_update_takeover));
        if (u == NULL)
                return 1;

        u->type = update_takeover;
        u->subarray = super->current_vol;

        /* 10->0 transition */
        if (geo->level == 0)
                u->direction = R10_TO_R0;

        /* 0->10 transition */
        if (geo->level == 10)
                u->direction = R0_TO_R10;

        /* update metadata locally */
        imsm_update_metadata_locally(st, u,
                                        sizeof(struct imsm_update_takeover));
        /* and possibly remotely */
        if (st->update_tail)
                append_metadata_update(st, u,
                                        sizeof(struct imsm_update_takeover));
        else
                free(u);

        return 0;
}

static int warn_user_about_risk(void)
{
        int rv = 0;

        fprintf(stderr,
                "\nThis is an experimental feature. Data on the RAID volume(s) "
                "can be lost!!!\n\n"
                "To continue command execution please make sure that\n"
                "the grow process will not be interrupted. Use safe power\n"
                "supply to avoid unexpected system reboot. Make sure that\n"
                "reshaped container is not assembled automatically during\n"
                "system boot.\n"
                "If reshape is interrupted, assemble array manually\n"
                "using e.g. '-Ac' option and up to date mdadm.conf file.\n"
                "Assembly in scan mode is not possible in such case.\n"
                "Growing container with boot array is not possible.\n"
                "If boot array reshape is interrupted, whole file system\n"
                "can be lost.\n\n");
        rv = ask("Do you want to continue? ");
        fprintf(stderr, "\n");

        return rv;
}

static int imsm_reshape_super(struct supertype *st, long long size, int level,
                              int layout, int chunksize, int raid_disks,
                              int delta_disks, char *backup, char *dev,
                              int verbose)
{
        int ret_val = 1;
        struct geo_params geo;

        dprintf("imsm: reshape_super called.\n");

        memset(&geo, 0, sizeof(struct geo_params));

        geo.dev_name = dev;
        geo.dev_id = st->devnum;
        geo.size = size;
        geo.level = level;
        geo.layout = layout;
        geo.chunksize = chunksize;
        geo.raid_disks = raid_disks;
        if (delta_disks != UnSet)
                geo.raid_disks += delta_disks;

        dprintf("\tfor level      : %i\n", geo.level);
        dprintf("\tfor raid_disks : %i\n", geo.raid_disks);

        if (experimental() == 0)
                return ret_val;

        if (st->container_dev == st->devnum) {
                /* On container level we can only increase number of devices. */
                dprintf("imsm: info: Container operation\n");
                int old_raid_disks = 0;

                /* this warning will be removed when imsm checkpointing
                 * will be implemented, and restoring from check-point
                 * operation will be transparent for reboot process
                 */
                if (warn_user_about_risk() == 0)
                        return ret_val;

                if (imsm_reshape_is_allowed_on_container(
                            st, &geo, &old_raid_disks)) {
                        struct imsm_update_reshape *u = NULL;
                        int len;

                        len = imsm_create_metadata_update_for_reshape(
                                st, &geo, old_raid_disks, &u);

                        if (len <= 0) {
                                dprintf("imsm: Cannot prepare update\n");
                                goto exit_imsm_reshape_super;
                        }

                        ret_val = 0;
                        /* update metadata locally */
                        imsm_update_metadata_locally(st, u, len);
                        /* and possibly remotely */
                        if (st->update_tail)
                                append_metadata_update(st, u, len);
                        else
                                free(u);

                } else {
                        fprintf(stderr, Name ": (imsm) Operation "
                                "is not allowed on this container\n");
                }
        } else {
                /* On volume level we support following operations
                 * - takeover: raid10 -> raid0; raid0 -> raid10
                 * - chunk size migration
                 * - migration: raid5 -> raid0; raid0 -> raid5
                 */
                struct intel_super *super = st->sb;
                struct intel_dev *dev = super->devlist;
                int change, devnum;
                dprintf("imsm: info: Volume operation\n");
                /* find requested device */
                while (dev) {
                        imsm_find_array_minor_by_subdev(dev->index, st->container_dev, &devnum);
                        if (devnum == geo.dev_id)
                                break;
                        dev = dev->next;
                }
                if (dev == NULL) {
                        fprintf(stderr, Name " Cannot find %s (%i) subarray\n",
                                geo.dev_name, geo.dev_id);
                        goto exit_imsm_reshape_super;
                }
                super->current_vol = dev->index;
                change = imsm_analyze_change(st, &geo);
                switch (change) {
                case CH_TAKEOVER:
                        ret_val = imsm_takeover(st, &geo);
                        break;
                case CH_MIGRATION: {
                        struct imsm_update_reshape_migration *u = NULL;
                        int len =
                                imsm_create_metadata_update_for_migration(
                                        st, &geo, &u);
                        if (len < 1) {
                                dprintf("imsm: "
                                        "Cannot prepare update\n");
                                break;
                        }
                        ret_val = 0;
                        /* update metadata locally */
                        imsm_update_metadata_locally(st, u, len);
                        /* and possibly remotely */
                        if (st->update_tail)
                                append_metadata_update(st, u, len);
                        else
                                free(u);
                }
                break;
                default:
                        ret_val = 1;
                }
        }

exit_imsm_reshape_super:
        dprintf("imsm: reshape_super Exit code = %i\n", ret_val);
        return ret_val;
}

/*******************************************************************************
 * Function:    wait_for_reshape_imsm
 * Description: Function writes new sync_max value and waits until
 *              reshape process reach new position
 * Parameters:
 *      sra             : general array info
 *      to_complete     : new sync_max position
 *      ndata           : number of disks in new array's layout
 * Returns:
 *       0 : success,
 *       1 : there is no reshape in progress,
 *      -1 : fail
 ******************************************************************************/
int wait_for_reshape_imsm(struct mdinfo *sra, unsigned long long to_complete,
                          int ndata)
{
        int fd = sysfs_get_fd(sra, NULL, "reshape_position");
        unsigned long long completed;

        struct timeval timeout;

        if (fd < 0)
                return 1;

        sysfs_fd_get_ll(fd, &completed);

        if (to_complete == 0) {/* reshape till the end of array */
                sysfs_set_str(sra, NULL, "sync_max", "max");
                to_complete = MaxSector;
        } else {
                if (completed > to_complete)
                        return -1;
                if (sysfs_set_num(sra, NULL, "sync_max",
                                  to_complete / ndata) != 0) {
                        close(fd);
                        return -1;
                }
        }

        /* FIXME should not need a timeout at all */
        timeout.tv_sec = 30;
        timeout.tv_usec = 0;
        do {
                char action[20];
                fd_set rfds;
                FD_ZERO(&rfds);
                FD_SET(fd, &rfds);
                select(fd+1, NULL, NULL, &rfds, &timeout);
                if (sysfs_fd_get_ll(fd, &completed) < 0) {
                        close(fd);
                        return 1;
                }
                if (sysfs_get_str(sra, NULL, "sync_action",
                                  action, 20) > 0 &&
                    strncmp(action, "reshape", 7) != 0)
                        break;
        } while (completed < to_complete);
        close(fd);
        return 0;

}

/*******************************************************************************
 * Function:    check_degradation_change
 * Description: Check that array hasn't become failed.
 * Parameters:
 *      info    : for sysfs access
 *      sources : source disks descriptors
 *      degraded: previous degradation level
 * Returns:
 *      degradation level
 ******************************************************************************/
int check_degradation_change(struct mdinfo *info,
                             int *sources,
                             int degraded)
{
        unsigned long long new_degraded;
        sysfs_get_ll(info, NULL, "degraded", &new_degraded);
        if (new_degraded != (unsigned long long)degraded) {
                /* check each device to ensure it is still working */
                struct mdinfo *sd;
                new_degraded = 0;
                for (sd = info->devs ; sd ; sd = sd->next) {
                        if (sd->disk.state & (1<<MD_DISK_FAULTY))
                                continue;
                        if (sd->disk.state & (1<<MD_DISK_SYNC)) {
                                char sbuf[20];
                                if (sysfs_get_str(info,
                                        sd, "state", sbuf, 20) < 0 ||
                                        strstr(sbuf, "faulty") ||
                                        strstr(sbuf, "in_sync") == NULL) {
                                        /* this device is dead */
                                        sd->disk.state = (1<<MD_DISK_FAULTY);
                                        if (sd->disk.raid_disk >= 0 &&
                                            sources[sd->disk.raid_disk] >= 0) {
                                                close(sources[
                                                        sd->disk.raid_disk]);
                                                sources[sd->disk.raid_disk] =
                                                        -1;
                                        }
                                        new_degraded++;
                                }
                        }
                }
        }

        return new_degraded;
}

/*******************************************************************************
 * Function:    imsm_manage_reshape
 * Description: Function finds array under reshape and it manages reshape
 *              process. It creates stripes backups (if required) and sets
 *              checheckpoits.
 * Parameters:
 *      afd             : Backup handle (nattive) - not used
 *      sra             : general array info
 *      reshape         : reshape parameters - not used
 *      st              : supertype structure
 *      blocks          : size of critical section [blocks]
 *      fds             : table of source device descriptor
 *      offsets         : start of array (offest per devices)
 *      dests           : not used
 *      destfd          : table of destination device descriptor
 *      destoffsets     : table of destination offsets (per device)
 * Returns:
 *      1 : success, reshape is done
 *      0 : fail
 ******************************************************************************/
static int imsm_manage_reshape(
        int afd, struct mdinfo *sra, struct reshape *reshape,
        struct supertype *st, unsigned long backup_blocks,
        int *fds, unsigned long long *offsets,
        int dests, int *destfd, unsigned long long *destoffsets)
{
        int ret_val = 0;
        struct intel_super *super = st->sb;
        struct intel_dev *dv = NULL;
        struct imsm_dev *dev = NULL;
        struct imsm_map *map_src, *map_dest;
        int migr_vol_qan = 0;
        int ndata, odata; /* [bytes] */
        int chunk; /* [bytes] */
        struct migr_record *migr_rec;
        char *buf = NULL;
        unsigned int buf_size; /* [bytes] */
        unsigned long long max_position; /* array size [bytes] */
        unsigned long long next_step; /* [blocks]/[bytes] */
        unsigned long long old_data_stripe_length;
        unsigned long long new_data_stripe_length;
        unsigned long long start_src; /* [bytes] */
        unsigned long long start; /* [bytes] */
        unsigned long long start_buf_shift; /* [bytes] */
        int degraded = 0;

        if (!fds || !offsets || !destfd || !destoffsets || !sra)
                goto abort;

        /* Find volume during the reshape */
        for (dv = super->devlist; dv; dv = dv->next) {
                if (dv->dev->vol.migr_type == MIGR_GEN_MIGR
                    && dv->dev->vol.migr_state == 1) {
                        dev = dv->dev;
                        migr_vol_qan++;
                }
        }
        /* Only one volume can migrate at the same time */
        if (migr_vol_qan != 1) {
                fprintf(stderr, Name " : %s", migr_vol_qan ?
                        "Number of migrating volumes greater than 1\n" :
                        "There is no volume during migrationg\n");
                goto abort;
        }

        map_src = get_imsm_map(dev, 1);
        if (map_src == NULL)
                goto abort;
        map_dest = get_imsm_map(dev, 0);

        ndata = imsm_num_data_members(dev, 0);
        odata = imsm_num_data_members(dev, 1);

        chunk = map_src->blocks_per_strip * 512;
        old_data_stripe_length = odata * chunk;

        migr_rec = super->migr_rec;

        /* [bytes] */
        sra->new_chunk = __le16_to_cpu(map_dest->blocks_per_strip) * 512;
        sra->new_level = map_dest->raid_level;
        new_data_stripe_length = sra->new_chunk * ndata;

        /* initialize migration record for start condition */
        if (sra->reshape_progress == 0)
                init_migr_record_imsm(st, dev, sra);

        /* size for data */
        buf_size = __le32_to_cpu(migr_rec->blocks_per_unit) * 512;
        /* extend  buffer size for parity disk */
        buf_size += __le32_to_cpu(migr_rec->dest_depth_per_unit) * 512;
        /* add space for stripe aligment */
        buf_size += old_data_stripe_length;
        if (posix_memalign((void **)&buf, 4096, buf_size)) {
                dprintf("imsm: Cannot allocate checpoint buffer\n");
                goto abort;
        }

        max_position =
                __le32_to_cpu(migr_rec->post_migr_vol_cap) +
                ((unsigned long long)__le32_to_cpu(
                         migr_rec->post_migr_vol_cap_hi) << 32);

        while (__le32_to_cpu(migr_rec->curr_migr_unit) <
               __le32_to_cpu(migr_rec->num_migr_units)) {
                /* current reshape position [blocks] */
                unsigned long long current_position =
                        __le32_to_cpu(migr_rec->blocks_per_unit)
                        * __le32_to_cpu(migr_rec->curr_migr_unit);
                unsigned long long border;

                /* Check that array hasn't become failed.
                 */
                degraded = check_degradation_change(sra, fds, degraded);
                if (degraded > 1) {
                        dprintf("imsm: Abort reshape due to degradation"
                                " level (%i)\n", degraded);
                        goto abort;
                }

                next_step = __le32_to_cpu(migr_rec->blocks_per_unit);

                if ((current_position + next_step) > max_position)
                        next_step = max_position - current_position;

                start = (map_src->pba_of_lba0 + dev->reserved_blocks +
                         current_position) * 512;

                /* allign reading start to old geometry */
                start_buf_shift = start % old_data_stripe_length;
                start_src = start - start_buf_shift;

                border = (start_src / odata) - (start / ndata);
                border /= 512;
                if (border <= __le32_to_cpu(migr_rec->dest_depth_per_unit)) {
                        /* save critical stripes to buf
                         * start     - start address of current unit
                         *             to backup [bytes]
                         * start_src - start address of current unit
                         *             to backup alligned to source array
                         *             [bytes]
                         */
                        unsigned long long next_step_filler = 0;
                        unsigned long long copy_length = next_step * 512;

                        /* allign copy area length to stripe in old geometry */
                        next_step_filler = ((copy_length + start_buf_shift)
                                            % old_data_stripe_length);
                        if (next_step_filler)
                                next_step_filler = (old_data_stripe_length
                                                    - next_step_filler);
                        dprintf("save_stripes() parameters: start = %llu,"
                                "\tstart_src = %llu,\tnext_step*512 = %llu,"
                                "\tstart_in_buf_shift = %llu,"
                                "\tnext_step_filler = %llu\n",
                                start, start_src, copy_length,
                                start_buf_shift, next_step_filler);

                        if (save_stripes(fds, offsets, map_src->num_members,
                                         chunk, sra->array.level,
                                         sra->array.layout, 0, NULL, start_src,
                                         copy_length +
                                         next_step_filler + start_buf_shift,
                                         buf)) {
                                dprintf("imsm: Cannot save stripes"
                                        " to buffer\n");
                                goto abort;
                        }
                        /* Convert data to destination format and store it
                         * in backup general migration area
                         */
                        if (save_backup_imsm(st, dev, sra,
                                             buf + start_buf_shift,
                                             ndata, copy_length)) {
                                dprintf("imsm: Cannot save stripes to "
                                        "target devices\n");
                                goto abort;
                        }
                        if (save_checkpoint_imsm(st, sra,
                                                 UNIT_SRC_IN_CP_AREA)) {
                                dprintf("imsm: Cannot write checkpoint to "
                                        "migration record (UNIT_SRC_IN_CP_AREA)\n");
                                goto abort;
                        }
                        /* decrease backup_blocks */
                        if (backup_blocks > (unsigned long)next_step)
                                backup_blocks -= next_step;
                        else
                                backup_blocks = 0;
                }
                /* When data backed up, checkpoint stored,
                 * kick the kernel to reshape unit of data
                 */
                next_step = next_step + sra->reshape_progress;
                sysfs_set_num(sra, NULL, "suspend_lo", sra->reshape_progress);
                sysfs_set_num(sra, NULL, "suspend_hi", next_step);

                /* wait until reshape finish */
                if (wait_for_reshape_imsm(sra, next_step, ndata) < 0) {
                        dprintf("wait_for_reshape_imsm returned error!\n");
                        goto abort;
                }

                sra->reshape_progress = next_step;

                if (save_checkpoint_imsm(st, sra, UNIT_SRC_NORMAL)) {
                        dprintf("imsm: Cannot write checkpoint to "
                                "migration record (UNIT_SRC_NORMAL)\n");
                        goto abort;
                }

        }

        /* return '1' if done */
        ret_val = 1;
abort:
        free(buf);
        abort_reshape(sra);

        return ret_val;
}
#endif /* MDASSEMBLE */

struct superswitch super_imsm = {
#ifndef MDASSEMBLE
        .examine_super  = examine_super_imsm,
        .brief_examine_super = brief_examine_super_imsm,
        .brief_examine_subarrays = brief_examine_subarrays_imsm,
        .export_examine_super = export_examine_super_imsm,
        .detail_super   = detail_super_imsm,
        .brief_detail_super = brief_detail_super_imsm,
        .write_init_super = write_init_super_imsm,
        .validate_geometry = validate_geometry_imsm,
        .add_to_super   = add_to_super_imsm,
        .remove_from_super = remove_from_super_imsm,
        .detail_platform = detail_platform_imsm,
        .kill_subarray = kill_subarray_imsm,
        .update_subarray = update_subarray_imsm,
        .load_container = load_container_imsm,
        .default_geometry = default_geometry_imsm,
        .get_disk_controller_domain = imsm_get_disk_controller_domain,
        .reshape_super  = imsm_reshape_super,
        .manage_reshape = imsm_manage_reshape,
#endif
        .match_home     = match_home_imsm,
        .uuid_from_super= uuid_from_super_imsm,
        .getinfo_super  = getinfo_super_imsm,
        .getinfo_super_disks = getinfo_super_disks_imsm,
        .update_super   = update_super_imsm,

        .avail_size     = avail_size_imsm,
        .min_acceptable_spare_size = min_acceptable_spare_size_imsm,

        .compare_super  = compare_super_imsm,

        .load_super     = load_super_imsm,
        .init_super     = init_super_imsm,
        .store_super    = store_super_imsm,
        .free_super     = free_super_imsm,
        .match_metadata_desc = match_metadata_desc_imsm,
        .container_content = container_content_imsm,

        .recover_backup = recover_backup_imsm,

        .external       = 1,
        .name = "imsm",

#ifndef MDASSEMBLE
/* for mdmon */
        .open_new       = imsm_open_new,
        .set_array_state= imsm_set_array_state,
        .set_disk       = imsm_set_disk,
        .sync_metadata  = imsm_sync_metadata,
        .activate_spare = imsm_activate_spare,
        .process_update = imsm_process_update,
        .prepare_update = imsm_prepare_update,
#endif /* MDASSEMBLE */
};