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

/*
 * mdadm - manage Linux "md" devices aka RAID arrays.
 *
 * Copyright (C) 2006-2007 Neil Brown <neilb@suse.de>
 *
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *    Author: Neil Brown
 *    Email: <neil@brown.name>
 *
 * Specifications for DDF takes from Common RAID DDF Specification Revision 1.2
 * (July 28 2006).  Reused by permission of SNIA.
 */

#define HAVE_STDINT_H 1
#include "mdadm.h"
#include "mdmon.h"
#include "sha1.h"
#include <values.h>

/* a non-official T10 name for creation GUIDs */
static char T10[] = "Linux-MD";

/* DDF timestamps are 1980 based, so we need to add
 * second-in-decade-of-seventies to convert to linux timestamps.
 * 10 years with 2 leap years.
 */
#define DECADE (3600*24*(365*10+2))
unsigned long crc32(
        unsigned long crc,
        const unsigned char *buf,
        unsigned len);

/* The DDF metadata handling.
 * DDF metadata lives at the end of the device.
 * The last 512 byte block provides an 'anchor' which is used to locate
 * the rest of the metadata which usually lives immediately behind the anchor.
 *
 * Note:
 *  - all multibyte numeric fields are bigendian.
 *  - all strings are space padded.
 *
 */

/* Primary Raid Level (PRL) */
#define DDF_RAID0       0x00
#define DDF_RAID1       0x01
#define DDF_RAID3       0x03
#define DDF_RAID4       0x04
#define DDF_RAID5       0x05
#define DDF_RAID1E      0x11
#define DDF_JBOD        0x0f
#define DDF_CONCAT      0x1f
#define DDF_RAID5E      0x15
#define DDF_RAID5EE     0x25
#define DDF_RAID6       0x06

/* Raid Level Qualifier (RLQ) */
#define DDF_RAID0_SIMPLE        0x00
#define DDF_RAID1_SIMPLE        0x00 /* just 2 devices in this plex */
#define DDF_RAID1_MULTI         0x01 /* exactly 3 devices in this plex */
#define DDF_RAID3_0             0x00 /* parity in first extent */
#define DDF_RAID3_N             0x01 /* parity in last extent */
#define DDF_RAID4_0             0x00 /* parity in first extent */
#define DDF_RAID4_N             0x01 /* parity in last extent */
/* these apply to raid5e and raid5ee as well */
#define DDF_RAID5_0_RESTART     0x00 /* same as 'right asymmetric' - layout 1 */
#define DDF_RAID6_0_RESTART     0x01 /* raid6 different from raid5 here!!! */
#define DDF_RAID5_N_RESTART     0x02 /* same as 'left asymmetric' - layout 0 */
#define DDF_RAID5_N_CONTINUE    0x03 /* same as 'left symmetric' - layout 2 */

#define DDF_RAID1E_ADJACENT     0x00 /* raid10 nearcopies==2 */
#define DDF_RAID1E_OFFSET       0x01 /* raid10 offsetcopies==2 */

/* Secondary RAID Level (SRL) */
#define DDF_2STRIPED    0x00    /* This is weirder than RAID0 !! */
#define DDF_2MIRRORED   0x01
#define DDF_2CONCAT     0x02
#define DDF_2SPANNED    0x03    /* This is also weird - be careful */

/* Magic numbers */
#define DDF_HEADER_MAGIC        __cpu_to_be32(0xDE11DE11)
#define DDF_CONTROLLER_MAGIC    __cpu_to_be32(0xAD111111)
#define DDF_PHYS_RECORDS_MAGIC  __cpu_to_be32(0x22222222)
#define DDF_PHYS_DATA_MAGIC     __cpu_to_be32(0x33333333)
#define DDF_VIRT_RECORDS_MAGIC  __cpu_to_be32(0xDDDDDDDD)
#define DDF_VD_CONF_MAGIC       __cpu_to_be32(0xEEEEEEEE)
#define DDF_SPARE_ASSIGN_MAGIC  __cpu_to_be32(0x55555555)
#define DDF_VU_CONF_MAGIC       __cpu_to_be32(0x88888888)
#define DDF_VENDOR_LOG_MAGIC    __cpu_to_be32(0x01dBEEF0)
#define DDF_BBM_LOG_MAGIC       __cpu_to_be32(0xABADB10C)

#define DDF_GUID_LEN    24
#define DDF_REVISION_0  "01.00.00"
#define DDF_REVISION_2  "01.02.00"

struct ddf_header {
        __u32   magic;          /* DDF_HEADER_MAGIC */
        __u32   crc;
        char    guid[DDF_GUID_LEN];
        char    revision[8];    /* 01.02.00 */
        __u32   seq;            /* starts at '1' */
        __u32   timestamp;
        __u8    openflag;
        __u8    foreignflag;
        __u8    enforcegroups;
        __u8    pad0;           /* 0xff */
        __u8    pad1[12];       /* 12 * 0xff */
        /* 64 bytes so far */
        __u8    header_ext[32]; /* reserved: fill with 0xff */
        __u64   primary_lba;
        __u64   secondary_lba;
        __u8    type;
        __u8    pad2[3];        /* 0xff */
        __u32   workspace_len;  /* sectors for vendor space -
                                 * at least 32768(sectors) */
        __u64   workspace_lba;
        __u16   max_pd_entries; /* one of 15, 63, 255, 1023, 4095 */
        __u16   max_vd_entries; /* 2^(4,6,8,10,12)-1 : i.e. as above */
        __u16   max_partitions; /* i.e. max num of configuration
                                   record entries per disk */
        __u16   config_record_len; /* 1 +ROUNDUP(max_primary_element_entries
                                                 *12/512) */
        __u16   max_primary_element_entries; /* 16, 64, 256, 1024, or 4096 */
        __u8    pad3[54];       /* 0xff */
        /* 192 bytes so far */
        __u32   controller_section_offset;
        __u32   controller_section_length;
        __u32   phys_section_offset;
        __u32   phys_section_length;
        __u32   virt_section_offset;
        __u32   virt_section_length;
        __u32   config_section_offset;
        __u32   config_section_length;
        __u32   data_section_offset;
        __u32   data_section_length;
        __u32   bbm_section_offset;
        __u32   bbm_section_length;
        __u32   diag_space_offset;
        __u32   diag_space_length;
        __u32   vendor_offset;
        __u32   vendor_length;
        /* 256 bytes so far */
        __u8    pad4[256];      /* 0xff */
};

/* type field */
#define DDF_HEADER_ANCHOR       0x00
#define DDF_HEADER_PRIMARY      0x01
#define DDF_HEADER_SECONDARY    0x02

/* The content of the 'controller section' - global scope */
struct ddf_controller_data {
        __u32   magic;                  /* DDF_CONTROLLER_MAGIC */
        __u32   crc;
        char    guid[DDF_GUID_LEN];
        struct controller_type {
                __u16 vendor_id;
                __u16 device_id;
                __u16 sub_vendor_id;
                __u16 sub_device_id;
        } type;
        char    product_id[16];
        __u8    pad[8]; /* 0xff */
        __u8    vendor_data[448];
};

/* The content of phys_section - global scope */
struct phys_disk {
        __u32   magic;          /* DDF_PHYS_RECORDS_MAGIC */
        __u32   crc;
        __u16   used_pdes;
        __u16   max_pdes;
        __u8    pad[52];
        struct phys_disk_entry {
                char    guid[DDF_GUID_LEN];
                __u32   refnum;
                __u16   type;
                __u16   state;
                __u64   config_size; /* DDF structures must be after here */
                char    path[18];       /* another horrible structure really */
                __u8    pad[6];
        } entries[0];
};

/* phys_disk_entry.type is a bitmap - bigendian remember */
#define DDF_Forced_PD_GUID              1
#define DDF_Active_in_VD                2
#define DDF_Global_Spare                4 /* VD_CONF records are ignored */
#define DDF_Spare                       8 /* overrides Global_spare */
#define DDF_Foreign                     16
#define DDF_Legacy                      32 /* no DDF on this device */

#define DDF_Interface_mask              0xf00
#define DDF_Interface_SCSI              0x100
#define DDF_Interface_SAS               0x200
#define DDF_Interface_SATA              0x300
#define DDF_Interface_FC                0x400

/* phys_disk_entry.state is a bigendian bitmap */
#define DDF_Online                      1
#define DDF_Failed                      2 /* overrides  1,4,8 */
#define DDF_Rebuilding                  4
#define DDF_Transition                  8
#define DDF_SMART                       16
#define DDF_ReadErrors                  32
#define DDF_Missing                     64

/* The content of the virt_section global scope */
struct virtual_disk {
        __u32   magic;          /* DDF_VIRT_RECORDS_MAGIC */
        __u32   crc;
        __u16   populated_vdes;
        __u16   max_vdes;
        __u8    pad[52];
        struct virtual_entry {
                char    guid[DDF_GUID_LEN];
                __u16   unit;
                __u16   pad0;   /* 0xffff */
                __u16   guid_crc;
                __u16   type;
                __u8    state;
                __u8    init_state;
                __u8    pad1[14];
                char    name[16];
        } entries[0];
};

/* virtual_entry.type is a bitmap - bigendian */
#define DDF_Shared              1
#define DDF_Enforce_Groups      2
#define DDF_Unicode             4
#define DDF_Owner_Valid         8

/* virtual_entry.state is a bigendian bitmap */
#define DDF_state_mask          0x7
#define DDF_state_optimal       0x0
#define DDF_state_degraded      0x1
#define DDF_state_deleted       0x2
#define DDF_state_missing       0x3
#define DDF_state_failed        0x4
#define DDF_state_part_optimal  0x5

#define DDF_state_morphing      0x8
#define DDF_state_inconsistent  0x10

/* virtual_entry.init_state is a bigendian bitmap */
#define DDF_initstate_mask      0x03
#define DDF_init_not            0x00
#define DDF_init_quick          0x01 /* initialisation is progress.
                                      * i.e. 'state_inconsistent' */
#define DDF_init_full           0x02

#define DDF_access_mask         0xc0
#define DDF_access_rw           0x00
#define DDF_access_ro           0x80
#define DDF_access_blocked      0xc0

/* The content of the config_section - local scope
 * It has multiple records each config_record_len sectors
 * They can be vd_config or spare_assign
 */

struct vd_config {
        __u32   magic;          /* DDF_VD_CONF_MAGIC */
        __u32   crc;
        char    guid[DDF_GUID_LEN];
        __u32   timestamp;
        __u32   seqnum;
        __u8    pad0[24];
        __u16   prim_elmnt_count;
        __u8    chunk_shift;    /* 0 == 512, 1==1024 etc */
        __u8    prl;
        __u8    rlq;
        __u8    sec_elmnt_count;
        __u8    sec_elmnt_seq;
        __u8    srl;
        __u64   blocks;         /* blocks per component could be different
                                 * on different component devices...(only
                                 * for concat I hope) */
        __u64   array_blocks;   /* blocks in array */
        __u8    pad1[8];
        __u32   spare_refs[8];
        __u8    cache_pol[8];
        __u8    bg_rate;
        __u8    pad2[3];
        __u8    pad3[52];
        __u8    pad4[192];
        __u8    v0[32]; /* reserved- 0xff */
        __u8    v1[32]; /* reserved- 0xff */
        __u8    v2[16]; /* reserved- 0xff */
        __u8    v3[16]; /* reserved- 0xff */
        __u8    vendor[32];
        __u32   phys_refnum[0]; /* refnum of each disk in sequence */
      /*__u64   lba_offset[0];  LBA offset in each phys.  Note extents in a
                                bvd are always the same size */
};

/* vd_config.cache_pol[7] is a bitmap */
#define DDF_cache_writeback     1       /* else writethrough */
#define DDF_cache_wadaptive     2       /* only applies if writeback */
#define DDF_cache_readahead     4
#define DDF_cache_radaptive     8       /* only if doing read-ahead */
#define DDF_cache_ifnobatt      16      /* even to write cache if battery is poor */
#define DDF_cache_wallowed      32      /* enable write caching */
#define DDF_cache_rallowed      64      /* enable read caching */

struct spare_assign {
        __u32   magic;          /* DDF_SPARE_ASSIGN_MAGIC */
        __u32   crc;
        __u32   timestamp;
        __u8    reserved[7];
        __u8    type;
        __u16   populated;      /* SAEs used */
        __u16   max;            /* max SAEs */
        __u8    pad[8];
        struct spare_assign_entry {
                char    guid[DDF_GUID_LEN];
                __u16   secondary_element;
                __u8    pad[6];
        } spare_ents[0];
};
/* spare_assign.type is a bitmap */
#define DDF_spare_dedicated     0x1     /* else global */
#define DDF_spare_revertible    0x2     /* else committable */
#define DDF_spare_active        0x4     /* else not active */
#define DDF_spare_affinity      0x8     /* enclosure affinity */

/* The data_section contents - local scope */
struct disk_data {
        __u32   magic;          /* DDF_PHYS_DATA_MAGIC */
        __u32   crc;
        char    guid[DDF_GUID_LEN];
        __u32   refnum;         /* crc of some magic drive data ... */
        __u8    forced_ref;     /* set when above was not result of magic */
        __u8    forced_guid;    /* set if guid was forced rather than magic */
        __u8    vendor[32];
        __u8    pad[442];
};

/* bbm_section content */
struct bad_block_log {
        __u32   magic;
        __u32   crc;
        __u16   entry_count;
        __u32   spare_count;
        __u8    pad[10];
        __u64   first_spare;
        struct mapped_block {
                __u64   defective_start;
                __u32   replacement_start;
                __u16   remap_count;
                __u8    pad[2];
        } entries[0];
};

/* Struct for internally holding ddf structures */
/* The DDF structure stored on each device is potentially
 * quite different, as some data is global and some is local.
 * The global data is:
 *   - ddf header
 *   - controller_data
 *   - Physical disk records
 *   - Virtual disk records
 * The local data is:
 *   - Configuration records
 *   - Physical Disk data section
 *  (  and Bad block and vendor which I don't care about yet).
 *
 * The local data is parsed into separate lists as it is read
 * and reconstructed for writing.  This means that we only need
 * to make config changes once and they are automatically
 * propagated to all devices.
 * Note that the ddf_super has space of the conf and disk data
 * for this disk and also for a list of all such data.
 * The list is only used for the superblock that is being
 * built in Create or Assemble to describe the whole array.
 */
struct ddf_super {
        struct ddf_header anchor, primary, secondary;
        struct ddf_controller_data controller;
        struct ddf_header *active;
        struct phys_disk        *phys;
        struct virtual_disk     *virt;
        int pdsize, vdsize;
        int max_part, mppe, conf_rec_len;
        int currentdev;
        int updates_pending;
        struct vcl {
                union {
                        char space[512];
                        struct {
                                struct vcl      *next;
                                __u64           *lba_offset; /* location in 'conf' of
                                                              * the lba table */
                                int     vcnum; /* index into ->virt */
                                __u64           *block_sizes; /* NULL if all the same */
                        };
                };
                struct vd_config conf;
        } *conflist, *currentconf;
        struct dl {
                union {
                        char space[512];
                        struct {
                                struct dl       *next;
                                int major, minor;
                                char *devname;
                                int fd;
                                unsigned long long size; /* sectors */
                                int pdnum;      /* index in ->phys */
                                struct spare_assign *spare;
                        };
                };
                struct disk_data disk;
                void *mdupdate; /* hold metadata update */
                struct vcl *vlist[0]; /* max_part in size */
        } *dlist, *add_list;
};

#ifndef offsetof
#define offsetof(t,f) ((size_t)&(((t*)0)->f))
#endif


static int calc_crc(void *buf, int len)
{
        /* crcs are always at the same place as in the ddf_header */
        struct ddf_header *ddf = buf;
        __u32 oldcrc = ddf->crc;
        __u32 newcrc;
        ddf->crc = 0xffffffff;

        newcrc = crc32(0, buf, len);
        ddf->crc = oldcrc;
        return newcrc;
}

static int load_ddf_header(int fd, unsigned long long lba,
                           unsigned long long size,
                           int type,
                           struct ddf_header *hdr, struct ddf_header *anchor)
{
        /* read a ddf header (primary or secondary) from fd/lba
         * and check that it is consistent with anchor
         * Need to check:
         *   magic, crc, guid, rev, and LBA's header_type, and
         *  everything after header_type must be the same
         */
        if (lba >= size-1)
                return 0;

        if (lseek64(fd, lba<<9, 0) < 0)
                return 0;

        if (read(fd, hdr, 512) != 512)
                return 0;

        if (hdr->magic != DDF_HEADER_MAGIC)
                return 0;
        if (calc_crc(hdr, 512) != hdr->crc)
                return 0;
        if (memcmp(anchor->guid, hdr->guid, DDF_GUID_LEN) != 0 ||
            memcmp(anchor->revision, hdr->revision, 8) != 0 ||
            anchor->primary_lba != hdr->primary_lba ||
            anchor->secondary_lba != hdr->secondary_lba ||
            hdr->type != type ||
            memcmp(anchor->pad2, hdr->pad2, 512 -
                   offsetof(struct ddf_header, pad2)) != 0)
                return 0;

        /* Looks good enough to me... */
        return 1;
}

static void *load_section(int fd, struct ddf_super *super, void *buf,
                          __u32 offset_be, __u32 len_be, int check)
{
        unsigned long long offset = __be32_to_cpu(offset_be);
        unsigned long long len = __be32_to_cpu(len_be);
        int dofree = (buf == NULL);

        if (check)
                if (len != 2 && len != 8 && len != 32
                    && len != 128 && len != 512)
                        return NULL;

        if (len > 1024)
                return NULL;
        if (buf) {
                /* All pre-allocated sections are a single block */
                if (len != 1)
                        return NULL;
        } else {
                posix_memalign(&buf, 512, len<<9);
        }

        if (!buf)
                return NULL;

        if (super->active->type == 1)
                offset += __be64_to_cpu(super->active->primary_lba);
        else
                offset += __be64_to_cpu(super->active->secondary_lba);

        if (lseek64(fd, offset<<9, 0) != (offset<<9)) {
                if (dofree)
                        free(buf);
                return NULL;
        }
        if (read(fd, buf, len<<9) != (len<<9)) {
                if (dofree)
                        free(buf);
                return NULL;
        }
        return buf;
}

static int load_ddf_headers(int fd, struct ddf_super *super, char *devname)
{
        unsigned long long dsize;

        get_dev_size(fd, NULL, &dsize);

        if (lseek64(fd, dsize-512, 0) < 0) {
                if (devname)
                        fprintf(stderr,
                                Name": Cannot seek to anchor block on %s: %s\n",
                                devname, strerror(errno));
                return 1;
        }
        if (read(fd, &super->anchor, 512) != 512) {
                if (devname)
                        fprintf(stderr,
                                Name ": Cannot read anchor block on %s: %s\n",
                                devname, strerror(errno));
                return 1;
        }
        if (super->anchor.magic != DDF_HEADER_MAGIC) {
                if (devname)
                        fprintf(stderr, Name ": no DDF anchor found on %s\n",
                                devname);
                return 2;
        }
        if (calc_crc(&super->anchor, 512) != super->anchor.crc) {
                if (devname)
                        fprintf(stderr, Name ": bad CRC on anchor on %s\n",
                                devname);
                return 2;
        }
        if (memcmp(super->anchor.revision, DDF_REVISION_0, 8) != 0 &&
            memcmp(super->anchor.revision, DDF_REVISION_2, 8) != 0) {
                if (devname)
                        fprintf(stderr, Name ": can only support super revision"
                                " %.8s and earlier, not %.8s on %s\n",
                                DDF_REVISION_2, super->anchor.revision,devname);
                return 2;
        }
        if (load_ddf_header(fd, __be64_to_cpu(super->anchor.primary_lba),
                            dsize >> 9,  1,
                            &super->primary, &super->anchor) == 0) {
                if (devname)
                        fprintf(stderr,
                                Name ": Failed to load primary DDF header "
                                "on %s\n", devname);
                return 2;
        }
        super->active = &super->primary;
        if (load_ddf_header(fd, __be64_to_cpu(super->anchor.secondary_lba),
                            dsize >> 9,  2,
                            &super->secondary, &super->anchor)) {
                if ((__be32_to_cpu(super->primary.seq)
                     < __be32_to_cpu(super->secondary.seq) &&
                     !super->secondary.openflag)
                    || (__be32_to_cpu(super->primary.seq)
                        == __be32_to_cpu(super->secondary.seq) &&
                        super->primary.openflag && !super->secondary.openflag)
                        )
                        super->active = &super->secondary;
        }
        return 0;
}

static int load_ddf_global(int fd, struct ddf_super *super, char *devname)
{
        void *ok;
        ok = load_section(fd, super, &super->controller,
                          super->active->controller_section_offset,
                          super->active->controller_section_length,
                          0);
        super->phys = load_section(fd, super, NULL,
                                   super->active->phys_section_offset,
                                   super->active->phys_section_length,
                                   1);
        super->pdsize = __be32_to_cpu(super->active->phys_section_length) * 512;

        super->virt = load_section(fd, super, NULL,
                                   super->active->virt_section_offset,
                                   super->active->virt_section_length,
                                   1);
        super->vdsize = __be32_to_cpu(super->active->virt_section_length) * 512;
        if (!ok ||
            !super->phys ||
            !super->virt) {
                free(super->phys);
                free(super->virt);
                super->phys = NULL;
                super->virt = NULL;
                return 2;
        }
        super->conflist = NULL;
        super->dlist = NULL;

        super->max_part = __be16_to_cpu(super->active->max_partitions);
        super->mppe = __be16_to_cpu(super->active->max_primary_element_entries);
        super->conf_rec_len = __be16_to_cpu(super->active->config_record_len);
        return 0;
}

static int load_ddf_local(int fd, struct ddf_super *super,
                          char *devname, int keep)
{
        struct dl *dl;
        struct stat stb;
        char *conf;
        int i;
        int vnum;
        int max_virt_disks = __be16_to_cpu(super->active->max_vd_entries);
        unsigned long long dsize;

        /* First the local disk info */
        posix_memalign((void**)&dl, 512,
                       sizeof(*dl) +
                       (super->max_part) * sizeof(dl->vlist[0]));

        load_section(fd, super, &dl->disk,
                     super->active->data_section_offset,
                     super->active->data_section_length,
                     0);
        dl->devname = devname ? strdup(devname) : NULL;

        fstat(fd, &stb);
        dl->major = major(stb.st_rdev);
        dl->minor = minor(stb.st_rdev);
        dl->next = super->dlist;
        dl->fd = keep ? fd : -1;

        dl->size = 0;
        if (get_dev_size(fd, devname, &dsize))
                dl->size = dsize >> 9;
        dl->spare = NULL;
        for (i=0 ; i < super->max_part ; i++)
                dl->vlist[i] = NULL;
        super->dlist = dl;
        dl->pdnum = -1;
        for (i=0; i < __be16_to_cpu(super->active->max_pd_entries); i++)
                if (memcmp(super->phys->entries[i].guid,
                           dl->disk.guid, DDF_GUID_LEN) == 0)
                        dl->pdnum = i;

        /* Now the config list. */
        /* 'conf' is an array of config entries, some of which are
         * probably invalid.  Those which are good need to be copied into
         * the conflist
         */

        conf = load_section(fd, super, NULL,
                            super->active->config_section_offset,
                            super->active->config_section_length,
                            0);

        vnum = 0;
        for (i = 0;
             i < __be32_to_cpu(super->active->config_section_length);
             i += super->conf_rec_len) {
                struct vd_config *vd =
                        (struct vd_config *)((char*)conf + i*512);
                struct vcl *vcl;

                if (vd->magic == DDF_SPARE_ASSIGN_MAGIC) {
                        if (dl->spare)
                                continue;
                        posix_memalign((void**)&dl->spare, 512,
                                       super->conf_rec_len*512);
                        memcpy(dl->spare, vd, super->conf_rec_len*512);
                        continue;
                }
                if (vd->magic != DDF_VD_CONF_MAGIC)
                        continue;
                for (vcl = super->conflist; vcl; vcl = vcl->next) {
                        if (memcmp(vcl->conf.guid,
                                   vd->guid, DDF_GUID_LEN) == 0)
                                break;
                }

                if (vcl) {
                        dl->vlist[vnum++] = vcl;
                        if (__be32_to_cpu(vd->seqnum) <=
                            __be32_to_cpu(vcl->conf.seqnum))
                                continue;
                } else {
                        posix_memalign((void**)&vcl, 512,
                                       (super->conf_rec_len*512 +
                                        offsetof(struct vcl, conf)));
                        vcl->next = super->conflist;
                        vcl->block_sizes = NULL; /* FIXME not for CONCAT */
                        super->conflist = vcl;
                        dl->vlist[vnum++] = vcl;
                }
                memcpy(&vcl->conf, vd, super->conf_rec_len*512);
                vcl->lba_offset = (__u64*)
                        &vcl->conf.phys_refnum[super->mppe];

                for (i=0; i < max_virt_disks ; i++)
                        if (memcmp(super->virt->entries[i].guid,
                                   vcl->conf.guid, DDF_GUID_LEN)==0)
                                break;
                if (i < max_virt_disks)
                        vcl->vcnum = i;
        }
        free(conf);

        return 0;
}

#ifndef MDASSEMBLE
static int load_super_ddf_all(struct supertype *st, int fd,
                              void **sbp, char *devname, int keep_fd);
#endif
static int load_super_ddf(struct supertype *st, int fd,
                          char *devname)
{
        unsigned long long dsize;
        struct ddf_super *super;
        int rv;

#ifndef MDASSEMBLE
        /* if 'fd' is a container, load metadata from all the devices */
        if (load_super_ddf_all(st, fd, &st->sb, devname, 1) == 0)
                return 0;
#endif
        if (st->subarray[0])
                return 1; /* FIXME Is this correct */

        if (get_dev_size(fd, devname, &dsize) == 0)
                return 1;

        /* 32M is a lower bound */
        if (dsize <= 32*1024*1024) {
                if (devname) {
                        fprintf(stderr,
                                Name ": %s is too small for ddf: "
                                "size is %llu sectors.\n",
                                devname, dsize>>9);
                        return 1;
                }
        }
        if (dsize & 511) {
                if (devname) {
                        fprintf(stderr,
                                Name ": %s is an odd size for ddf: "
                                "size is %llu bytes.\n",
                                devname, dsize);
                        return 1;
                }
        }

        if (posix_memalign((void**)&super, 512, sizeof(*super))!= 0) {
                fprintf(stderr, Name ": malloc of %zu failed.\n",
                        sizeof(*super));
                return 1;
        }
        memset(super, 0, sizeof(*super));

        rv = load_ddf_headers(fd, super, devname);
        if (rv) {
                free(super);
                return rv;
        }

        /* Have valid headers and have chosen the best. Let's read in the rest*/

        rv = load_ddf_global(fd, super, devname);

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

        load_ddf_local(fd, super, devname, 0);

        /* Should possibly check the sections .... */

        st->sb = super;
        if (st->ss == NULL) {
                st->ss = &super_ddf;
                st->minor_version = 0;
                st->max_devs = 512;
        }
        return 0;

}

static void free_super_ddf(struct supertype *st)
{
        struct ddf_super *ddf = st->sb;
        if (ddf == NULL)
                return;
        free(ddf->phys);
        free(ddf->virt);
        while (ddf->conflist) {
                struct vcl *v = ddf->conflist;
                ddf->conflist = v->next;
                if (v->block_sizes)
                        free(v->block_sizes);
                free(v);
        }
        while (ddf->dlist) {
                struct dl *d = ddf->dlist;
                ddf->dlist = d->next;
                if (d->fd >= 0)
                        close(d->fd);
                if (d->spare)
                        free(d->spare);
                free(d);
        }
        free(ddf);
        st->sb = NULL;
}

static struct supertype *match_metadata_desc_ddf(char *arg)
{
        /* 'ddf' only support containers */
        struct supertype *st;
        if (strcmp(arg, "ddf") != 0 &&
            strcmp(arg, "default") != 0
                )
                return NULL;

        st = malloc(sizeof(*st));
        memset(st, 0, sizeof(*st));
        st->ss = &super_ddf;
        st->max_devs = 512;
        st->minor_version = 0;
        st->sb = NULL;
        return st;
}


#ifndef MDASSEMBLE

static mapping_t ddf_state[] = {
        { "Optimal", 0},
        { "Degraded", 1},
        { "Deleted", 2},
        { "Missing", 3},
        { "Failed", 4},
        { "Partially Optimal", 5},
        { "-reserved-", 6},
        { "-reserved-", 7},
        { NULL, 0}
};

static mapping_t ddf_init_state[] = {
        { "Not Initialised", 0},
        { "QuickInit in Progress", 1},
        { "Fully Initialised", 2},
        { "*UNKNOWN*", 3},
        { NULL, 0}
};
static mapping_t ddf_access[] = {
        { "Read/Write", 0},
        { "Reserved", 1},
        { "Read Only", 2},
        { "Blocked (no access)", 3},
        { NULL ,0}
};

static mapping_t ddf_level[] = {
        { "RAID0", DDF_RAID0},
        { "RAID1", DDF_RAID1},
        { "RAID3", DDF_RAID3},
        { "RAID4", DDF_RAID4},
        { "RAID5", DDF_RAID5},
        { "RAID1E",DDF_RAID1E},
        { "JBOD",  DDF_JBOD},
        { "CONCAT",DDF_CONCAT},
        { "RAID5E",DDF_RAID5E},
        { "RAID5EE",DDF_RAID5EE},
        { "RAID6", DDF_RAID6},
        { NULL, 0}
};
static mapping_t ddf_sec_level[] = {
        { "Striped", DDF_2STRIPED},
        { "Mirrored", DDF_2MIRRORED},
        { "Concat", DDF_2CONCAT},
        { "Spanned", DDF_2SPANNED},
        { NULL, 0}
};
#endif

struct num_mapping {
        int num1, num2;
};
static struct num_mapping ddf_level_num[] = {
        { DDF_RAID0, 0 },
        { DDF_RAID1, 1 },
        { DDF_RAID3, LEVEL_UNSUPPORTED },
        { DDF_RAID4, 4 },
        { DDF_RAID5, 5 },
        { DDF_RAID1E, LEVEL_UNSUPPORTED },
        { DDF_JBOD, LEVEL_UNSUPPORTED },
        { DDF_CONCAT, LEVEL_LINEAR },
        { DDF_RAID5E, LEVEL_UNSUPPORTED },
        { DDF_RAID5EE, LEVEL_UNSUPPORTED },
        { DDF_RAID6, 6},
        { MAXINT, MAXINT }
};

static int map_num1(struct num_mapping *map, int num)
{
        int i;
        for (i=0 ; map[i].num1 != MAXINT; i++)
                if (map[i].num1 == num)
                        break;
        return map[i].num2;
}

#ifndef MDASSEMBLE
static void print_guid(char *guid, int tstamp)
{
        /* A GUIDs are part (or all) ASCII and part binary.
         * They tend to be space padded.
         * We print the GUID in HEX, then in parentheses add
         * any initial ASCII sequence, and a possible
         * time stamp from bytes 16-19
         */
        int l = DDF_GUID_LEN;
        int i;

        for (i=0 ; i<DDF_GUID_LEN ; i++) {
                if ((i&3)==0 && i != 0) printf(":");
                printf("%02X", guid[i]&255);
        }

        printf(" (");
        while (l && guid[l-1] == ' ')
                l--;
        for (i=0 ; i<l ; i++) {
                if (guid[i] >= 0x20 && guid[i] < 0x7f)
                        fputc(guid[i], stdout);
                else
                        break;
        }
        if (tstamp) {
                time_t then = __be32_to_cpu(*(__u32*)(guid+16)) + DECADE;
                char tbuf[100];
                struct tm *tm;
                tm = localtime(&then);
                strftime(tbuf, 100, " %D %T",tm);
                fputs(tbuf, stdout);
        }
        printf(")");
}

static void examine_vd(int n, struct ddf_super *sb, char *guid)
{
        int crl = sb->conf_rec_len;
        struct vcl *vcl;

        for (vcl = sb->conflist ; vcl ; vcl = vcl->next) {
                struct vd_config *vc = &vcl->conf;

                if (calc_crc(vc, crl*512) != vc->crc)
                        continue;
                if (memcmp(vc->guid, guid, DDF_GUID_LEN) != 0)
                        continue;

                /* Ok, we know about this VD, let's give more details */
                printf(" Raid Devices[%d] : %d\n", n,
                       __be16_to_cpu(vc->prim_elmnt_count));
                printf("   Chunk Size[%d] : %d sectors\n", n,
                       1 << vc->chunk_shift);
                printf("   Raid Level[%d] : %s\n", n,
                       map_num(ddf_level, vc->prl)?:"-unknown-");
                if (vc->sec_elmnt_count != 1) {
                        printf("  Secondary Position[%d] : %d of %d\n", n,
                               vc->sec_elmnt_seq, vc->sec_elmnt_count);
                        printf("  Secondary Level[%d] : %s\n", n,
                               map_num(ddf_sec_level, vc->srl) ?: "-unknown-");
                }
                printf("  Device Size[%d] : %llu\n", n,
                       __be64_to_cpu(vc->blocks)/2);
                printf("   Array Size[%d] : %llu\n", n,
                       __be64_to_cpu(vc->array_blocks)/2);
        }
}

static void examine_vds(struct ddf_super *sb)
{
        int cnt = __be16_to_cpu(sb->virt->populated_vdes);
        int i;
        printf("  Virtual Disks : %d\n", cnt);

        for (i=0; i<cnt; i++) {
                struct virtual_entry *ve = &sb->virt->entries[i];
                printf("      VD GUID[%d] : ", i); print_guid(ve->guid, 1);
                printf("\n");
                printf("         unit[%d] : %d\n", i, __be16_to_cpu(ve->unit));
                printf("        state[%d] : %s, %s%s\n", i,
                       map_num(ddf_state, ve->state & 7),
                       (ve->state & 8) ? "Morphing, ": "",
                       (ve->state & 16)? "Not Consistent" : "Consistent");
                printf("   init state[%d] : %s\n", i,
                       map_num(ddf_init_state, ve->init_state&3));
                printf("       access[%d] : %s\n", i,
                       map_num(ddf_access, (ve->init_state>>6) & 3));
                printf("         Name[%d] : %.16s\n", i, ve->name);
                examine_vd(i, sb, ve->guid);
        }
        if (cnt) printf("\n");
}

static void examine_pds(struct ddf_super *sb)
{
        int cnt = __be16_to_cpu(sb->phys->used_pdes);
        int i;
        struct dl *dl;
        printf(" Physical Disks : %d\n", cnt);

        for (i=0 ; i<cnt ; i++) {
                struct phys_disk_entry *pd = &sb->phys->entries[i];
                int type = __be16_to_cpu(pd->type);
                int state = __be16_to_cpu(pd->state);

                printf("      PD GUID[%d] : ", i); print_guid(pd->guid, 0);
                printf("\n");
                printf("          ref[%d] : %08x\n", i,
                       __be32_to_cpu(pd->refnum));
                printf("         mode[%d] : %s%s%s%s%s\n", i,
                       (type&2) ? "active":"",
                       (type&4) ? "Global Spare":"",
                       (type&8) ? "spare" : "",
                       (type&16)? ", foreign" : "",
                       (type&32)? "pass-through" : "");
                printf("        state[%d] : %s%s%s%s%s%s%s\n", i,
                       (state&1)? "Online": "Offline",
                       (state&2)? ", Failed": "",
                       (state&4)? ", Rebuilding": "",
                       (state&8)? ", in-transition": "",
                       (state&16)? ", SMART errors": "",
                       (state&32)? ", Unrecovered Read Errors": "",
                       (state&64)? ", Missing" : "");
                printf("   Avail Size[%d] : %llu K\n", i,
                       __be64_to_cpu(pd->config_size)>>1);
                for (dl = sb->dlist; dl ; dl = dl->next) {
                        if (dl->disk.refnum == pd->refnum) {
                                char *dv = map_dev(dl->major, dl->minor, 0);
                                if (dv)
                                        printf("       Device[%d] : %s\n",
                                               i, dv);
                        }
                }
                printf("\n");
        }
}

static void examine_super_ddf(struct supertype *st, char *homehost)
{
        struct ddf_super *sb = st->sb;

        printf("          Magic : %08x\n", __be32_to_cpu(sb->anchor.magic));
        printf("        Version : %.8s\n", sb->anchor.revision);
        printf("Controller GUID : "); print_guid(sb->controller.guid, 0);
        printf("\n");
        printf(" Container GUID : "); print_guid(sb->anchor.guid, 1);
        printf("\n");
        printf("            Seq : %08x\n", __be32_to_cpu(sb->active->seq));
        printf("  Redundant hdr : %s\n", sb->secondary.magic == DDF_HEADER_MAGIC
               ?"yes" : "no");
        examine_vds(sb);
        examine_pds(sb);
}

static void brief_examine_super_ddf(struct supertype *st)
{
        /* We just write a generic DDF ARRAY entry
         * The uuid is all hex, 6 groups of 4 bytes
         */
        struct ddf_super *ddf = st->sb;
        int i;
        printf("ARRAY /dev/ddf metadata=ddf UUID=");
        for (i = 0; i < DDF_GUID_LEN; i++) {
                if ((i&3) == 0 && i != 0)
                        printf(":");
                printf("%02X", 255&ddf->anchor.guid[i]);
        }
        printf("\n");
}

static void detail_super_ddf(struct supertype *st, char *homehost)
{
        /* FIXME later
         * Could print DDF GUID
         * Need to find which array
         *  If whole, briefly list all arrays
         *  If one, give name
         */
}

static void brief_detail_super_ddf(struct supertype *st)
{
        /* FIXME I really need to know which array we are detailing.
         * Can that be stored in ddf_super??
         */
//      struct ddf_super *ddf = st->sb;
}
#endif

static int match_home_ddf(struct supertype *st, char *homehost)
{
        /* It matches 'this' host if the controller is a
         * Linux-MD controller with vendor_data matching
         * the hostname
         */
        struct ddf_super *ddf = st->sb;
        int len = strlen(homehost);

        return (memcmp(ddf->controller.guid, T10, 8) == 0 &&
                len < sizeof(ddf->controller.vendor_data) &&
                memcmp(ddf->controller.vendor_data, homehost,len) == 0 &&
                ddf->controller.vendor_data[len] == 0);
}

#ifndef MDASSEMBLE
static struct vd_config *find_vdcr(struct ddf_super *ddf, int inst)
{
        struct vcl *v;

        for (v = ddf->conflist; v; v = v->next)
                if (inst == v->vcnum)
                        return &v->conf;
        return NULL;
}
#endif

static int find_phys(struct ddf_super *ddf, __u32 phys_refnum)
{
        /* Find the entry in phys_disk which has the given refnum
         * and return it's index
         */
        int i;
        for (i=0; i < __be16_to_cpu(ddf->phys->max_pdes); i++)
                if (ddf->phys->entries[i].refnum == phys_refnum)
                        return i;
        return -1;
}

static void uuid_from_super_ddf(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
         * 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.
         * In the case of SVD we assume the BVD is of interest,
         * though that might be the case if a bitmap were made for
         * a mirrored SVD - worry about that later.
         * So we need to find the VD configuration record for the
         * relevant BVD and extract the GUID and Secondary_Element_Seq.
         * The first 16 bytes of the sha1 of these is used.
         */
        struct ddf_super *ddf = st->sb;
        struct vcl *vcl = ddf->currentconf;

        if (!vcl)
                memset(uuid, 0, sizeof (uuid));
        else {
                char buf[20];
                struct sha1_ctx ctx;
                sha1_init_ctx(&ctx);
                sha1_process_bytes(&vcl->conf.guid, DDF_GUID_LEN, &ctx);
                if (vcl->conf.sec_elmnt_count > 1)
                        sha1_process_bytes(&vcl->conf.sec_elmnt_seq, 1, &ctx);
                sha1_finish_ctx(&ctx, buf);
                memcpy(uuid, buf, sizeof(uuid));
        }
}

static void getinfo_super_ddf_bvd(struct supertype *st, struct mdinfo *info);

static void getinfo_super_ddf(struct supertype *st, struct mdinfo *info)
{
        struct ddf_super *ddf = st->sb;

        if (ddf->currentconf) {
                getinfo_super_ddf_bvd(st, info);
                return;
        }

        info->array.raid_disks    = __be16_to_cpu(ddf->phys->used_pdes);
        info->array.level         = LEVEL_CONTAINER;
        info->array.layout        = 0;
        info->array.md_minor      = -1;
        info->array.ctime         = DECADE + __be32_to_cpu(*(__u32*)
                                                         (ddf->anchor.guid+16));
        info->array.utime         = 0;
        info->array.chunk_size    = 0;


        info->disk.major = 0;
        info->disk.minor = 0;
        if (ddf->dlist) {
                info->disk.number = __be32_to_cpu(ddf->dlist->disk.refnum);
                info->disk.raid_disk = find_phys(ddf, ddf->dlist->disk.refnum);

                info->data_offset = __be64_to_cpu(ddf->phys->
                                          entries[info->disk.raid_disk].
                                          config_size);
                info->component_size = ddf->dlist->size - info->data_offset;
        } else {
                info->disk.number = -1;
//              info->disk.raid_disk = find refnum in the table and use index;
        }
        info->disk.state = (1 << MD_DISK_SYNC);


        info->reshape_active = 0;

        info->array.major_version = -1;
        info->array.minor_version = -2;
        strcpy(info->text_version, "ddf");
        info->safe_mode_delay = 0;

//      uuid_from_super_ddf(info->uuid, sbv);

//      info->name[] ?? ;
}

static int rlq_to_layout(int rlq, int prl, int raiddisks);

static void getinfo_super_ddf_bvd(struct supertype *st, struct mdinfo *info)
{
        struct ddf_super *ddf = st->sb;
        struct vcl *vc = ddf->currentconf;
        int cd = ddf->currentdev;

        /* FIXME this returns BVD info - what if we want SVD ?? */

        info->array.raid_disks    = __be16_to_cpu(vc->conf.prim_elmnt_count);
        info->array.level         = map_num1(ddf_level_num, vc->conf.prl);
        info->array.layout        = rlq_to_layout(vc->conf.rlq, vc->conf.prl,
                                                  info->array.raid_disks);
        info->array.md_minor      = -1;
        info->array.ctime         = DECADE +
                __be32_to_cpu(*(__u32*)(vc->conf.guid+16));
        info->array.utime         = DECADE + __be32_to_cpu(vc->conf.timestamp);
        info->array.chunk_size    = 512 << vc->conf.chunk_shift;

        if (cd >= 0 && cd < ddf->mppe) {
                info->data_offset         = __be64_to_cpu(vc->lba_offset[cd]);
                if (vc->block_sizes)
                        info->component_size = vc->block_sizes[cd];
                else
                        info->component_size = __be64_to_cpu(vc->conf.blocks);
        }

        info->disk.major = 0;
        info->disk.minor = 0;
//      info->disk.number = __be32_to_cpu(ddf->disk.refnum);
//      info->disk.raid_disk = find refnum in the table and use index;
//      info->disk.state = ???;

        info->container_member = ddf->currentconf->vcnum;

        info->resync_start = 0;
        if (!(ddf->virt->entries[info->container_member].state
              & DDF_state_inconsistent)  &&
            (ddf->virt->entries[info->container_member].init_state
             & DDF_initstate_mask)
            == DDF_init_full)
                info->resync_start = ~0ULL;

        uuid_from_super_ddf(st, info->uuid);

        info->container_member = atoi(st->subarray);
        info->array.major_version = -1;
        info->array.minor_version = -2;
        sprintf(info->text_version, "/%s/%s",
                devnum2devname(st->container_dev),
                st->subarray);
        info->safe_mode_delay = 200;

//      info->name[] ?? ;
}


static int update_super_ddf(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.
         *  uuid:  Change the uuid of the array to match what is given
         *  homehost:  update the recorded homehost
         *  name:  update the name - preserving the homehost
         *  _reshape_progress: record new reshape_progress position.
         *
         * Following are not relevant for this version:
         *  sparc2.2 : update from old dodgey metadata
         *  super-minor: change the preferred_minor number
         *  summaries:  update redundant counters.
         */
        int rv = 0;
//      struct ddf_super *ddf = st->sb;
//      struct vd_config *vd = find_vdcr(ddf, info->container_member);
//      struct virtual_entry *ve = find_ve(ddf);

        /* we don't need to handle "force-*" or "assemble" as
         * there is no need to 'trick' the kernel.  We the metadata is
         * first updated to activate the array, all the implied modifications
         * will just happen.
         */

        if (strcmp(update, "grow") == 0) {
                /* FIXME */
        }
        if (strcmp(update, "resync") == 0) {
//              info->resync_checkpoint = 0;
        }
        /* We ignore UUID updates as they make even less sense
         * with DDF
         */
        if (strcmp(update, "homehost") == 0) {
                /* homehost is stored in controller->vendor_data,
                 * or it is when we are the vendor
                 */
//              if (info->vendor_is_local)
//                      strcpy(ddf->controller.vendor_data, homehost);
        }
        if (strcmp(update, "name") == 0) {
                /* name is stored in virtual_entry->name */
//              memset(ve->name, ' ', 16);
//              strncpy(ve->name, info->name, 16);
        }
        if (strcmp(update, "_reshape_progress") == 0) {
                /* We don't support reshape yet */
        }

//      update_all_csum(ddf);

        return rv;
}

static void make_header_guid(char *guid)
{
        __u32 stamp;
        int rfd;
        /* Create a DDF Header of Virtual Disk GUID */

        /* 24 bytes of fiction required.
         * first 8 are a 'vendor-id'  - "Linux-MD"
         * next 8 are controller type.. how about 0X DEAD BEEF 0000 0000
         * Remaining 8 random number plus timestamp
         */
        memcpy(guid, T10, sizeof(T10));
        stamp = __cpu_to_be32(0xdeadbeef);
        memcpy(guid+8, &stamp, 4);
        stamp = __cpu_to_be32(0);
        memcpy(guid+12, &stamp, 4);
        stamp = __cpu_to_be32(time(0) - DECADE);
        memcpy(guid+16, &stamp, 4);
        rfd = open("/dev/urandom", O_RDONLY);
        if (rfd < 0 || read(rfd, &stamp, 4) != 4)
                stamp = random();
        memcpy(guid+20, &stamp, 4);
        if (rfd >= 0) close(rfd);
}

static int init_super_ddf_bvd(struct supertype *st,
                              mdu_array_info_t *info,
                              unsigned long long size,
                              char *name, char *homehost,
                              int *uuid);

static int init_super_ddf(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 DDF, 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.
         *
         * We need to create the entire 'ddf' structure which includes:
         *  DDF headers - these are easy.
         *  Controller data - a Sector describing this controller .. not that
         *                  this is a controller exactly.
         *  Physical Disk Record - one entry per device, so
         *                      leave plenty of space.
         *  Virtual Disk Records - again, just leave plenty of space.
         *                   This just lists VDs, doesn't give details
         *  Config records - describes the VDs that use this disk
         *  DiskData  - describes 'this' device.
         *  BadBlockManagement - empty
         *  Diag Space - empty
         *  Vendor Logs - Could we put bitmaps here?
         *
         */
        struct ddf_super *ddf;
        char hostname[17];
        int hostlen;
        int max_phys_disks, max_virt_disks;
        unsigned long long sector;
        int clen;
        int i;
        int pdsize, vdsize;
        struct phys_disk *pd;
        struct virtual_disk *vd;

        if (!info) {
                st->sb = NULL;
                return 0;
        }
        if (st->sb)
                return init_super_ddf_bvd(st, info, size, name, homehost,
                                          uuid);

        posix_memalign((void**)&ddf, 512, sizeof(*ddf));
        memset(ddf, 0, sizeof(*ddf));
        ddf->dlist = NULL; /* no physical disks yet */
        ddf->conflist = NULL; /* No virtual disks yet */

        /* At least 32MB *must* be reserved for the ddf.  So let's just
         * start 32MB from the end, and put the primary header there.
         * Don't do secondary for now.
         * We don't know exactly where that will be yet as it could be
         * different on each device.  To just set up the lengths.
         *
         */

        ddf->anchor.magic = DDF_HEADER_MAGIC;
        make_header_guid(ddf->anchor.guid);

        memcpy(ddf->anchor.revision, DDF_REVISION_2, 8);
        ddf->anchor.seq = __cpu_to_be32(1);
        ddf->anchor.timestamp = __cpu_to_be32(time(0) - DECADE);
        ddf->anchor.openflag = 0xFF;
        ddf->anchor.foreignflag = 0;
        ddf->anchor.enforcegroups = 0; /* Is this best?? */
        ddf->anchor.pad0 = 0xff;
        memset(ddf->anchor.pad1, 0xff, 12);
        memset(ddf->anchor.header_ext, 0xff, 32);
        ddf->anchor.primary_lba = ~(__u64)0;
        ddf->anchor.secondary_lba = ~(__u64)0;
        ddf->anchor.type = DDF_HEADER_ANCHOR;
        memset(ddf->anchor.pad2, 0xff, 3);
        ddf->anchor.workspace_len = __cpu_to_be32(32768); /* Must be reserved */
        ddf->anchor.workspace_lba = ~(__u64)0; /* Put this at bottom
                                                  of 32M reserved.. */
        max_phys_disks = 1023;   /* Should be enough */
        ddf->anchor.max_pd_entries = __cpu_to_be16(max_phys_disks);
        max_virt_disks = 255;
        ddf->anchor.max_vd_entries = __cpu_to_be16(max_virt_disks); /* ?? */
        ddf->anchor.max_partitions = __cpu_to_be16(64); /* ?? */
        ddf->max_part = 64;
        ddf->mppe = 256;
        ddf->conf_rec_len = 1 + ROUND_UP(ddf->mppe * (4+8), 512)/512;
        ddf->anchor.config_record_len = __cpu_to_be16(ddf->conf_rec_len);
        ddf->anchor.max_primary_element_entries = __cpu_to_be16(ddf->mppe);
        memset(ddf->anchor.pad3, 0xff, 54);
        /* controller sections is one sector long immediately
         * after the ddf header */
        sector = 1;
        ddf->anchor.controller_section_offset = __cpu_to_be32(sector);
        ddf->anchor.controller_section_length = __cpu_to_be32(1);
        sector += 1;

        /* phys is 8 sectors after that */
        pdsize = ROUND_UP(sizeof(struct phys_disk) +
                          sizeof(struct phys_disk_entry)*max_phys_disks,
                          512);
        switch(pdsize/512) {
        case 2: case 8: case 32: case 128: case 512: break;
        default: abort();
        }
        ddf->anchor.phys_section_offset = __cpu_to_be32(sector);
        ddf->anchor.phys_section_length =
                __cpu_to_be32(pdsize/512); /* max_primary_element_entries/8 */
        sector += pdsize/512;

        /* virt is another 32 sectors */
        vdsize = ROUND_UP(sizeof(struct virtual_disk) +
                          sizeof(struct virtual_entry) * max_virt_disks,
                          512);
        switch(vdsize/512) {
        case 2: case 8: case 32: case 128: case 512: break;
        default: abort();
        }
        ddf->anchor.virt_section_offset = __cpu_to_be32(sector);
        ddf->anchor.virt_section_length =
                __cpu_to_be32(vdsize/512); /* max_vd_entries/8 */
        sector += vdsize/512;

        clen = ddf->conf_rec_len * (ddf->max_part+1);
        ddf->anchor.config_section_offset = __cpu_to_be32(sector);
        ddf->anchor.config_section_length = __cpu_to_be32(clen);
        sector += clen;

        ddf->anchor.data_section_offset = __cpu_to_be32(sector);
        ddf->anchor.data_section_length = __cpu_to_be32(1);
        sector += 1;

        ddf->anchor.bbm_section_length = __cpu_to_be32(0);
        ddf->anchor.bbm_section_offset = __cpu_to_be32(0xFFFFFFFF);
        ddf->anchor.diag_space_length = __cpu_to_be32(0);
        ddf->anchor.diag_space_offset = __cpu_to_be32(0xFFFFFFFF);
        ddf->anchor.vendor_length = __cpu_to_be32(0);
        ddf->anchor.vendor_offset = __cpu_to_be32(0xFFFFFFFF);

        memset(ddf->anchor.pad4, 0xff, 256);

        memcpy(&ddf->primary, &ddf->anchor, 512);
        memcpy(&ddf->secondary, &ddf->anchor, 512);

        ddf->primary.openflag = 1; /* I guess.. */
        ddf->primary.type = DDF_HEADER_PRIMARY;

        ddf->secondary.openflag = 1; /* I guess.. */
        ddf->secondary.type = DDF_HEADER_SECONDARY;

        ddf->active = &ddf->primary;

        ddf->controller.magic = DDF_CONTROLLER_MAGIC;

        /* 24 more bytes of fiction required.
         * first 8 are a 'vendor-id'  - "Linux-MD"
         * Remaining 16 are serial number.... maybe a hostname would do?
         */
        memcpy(ddf->controller.guid, T10, sizeof(T10));
        gethostname(hostname, sizeof(hostname));
        hostname[sizeof(hostname) - 1] = 0;
        hostlen = strlen(hostname);
        memcpy(ddf->controller.guid + 24 - hostlen, hostname, hostlen);
        for (i = strlen(T10) ; i+hostlen < 24; i++)
                ddf->controller.guid[i] = ' ';

        ddf->controller.type.vendor_id = __cpu_to_be16(0xDEAD);
        ddf->controller.type.device_id = __cpu_to_be16(0xBEEF);
        ddf->controller.type.sub_vendor_id = 0;
        ddf->controller.type.sub_device_id = 0;
        memcpy(ddf->controller.product_id, "What Is My PID??", 16);
        memset(ddf->controller.pad, 0xff, 8);
        memset(ddf->controller.vendor_data, 0xff, 448);

        posix_memalign((void**)&pd, 512, pdsize);
        ddf->phys = pd;
        ddf->pdsize = pdsize;

        memset(pd, 0xff, pdsize);
        memset(pd, 0, sizeof(*pd));
        pd->magic = DDF_PHYS_DATA_MAGIC;
        pd->used_pdes = __cpu_to_be16(0);
        pd->max_pdes = __cpu_to_be16(max_phys_disks);
        memset(pd->pad, 0xff, 52);

        posix_memalign((void**)&vd, 512, vdsize);
        ddf->virt = vd;
        ddf->vdsize = vdsize;
        memset(vd, 0, vdsize);
        vd->magic = DDF_VIRT_RECORDS_MAGIC;
        vd->populated_vdes = __cpu_to_be16(0);
        vd->max_vdes = __cpu_to_be16(max_virt_disks);
        memset(vd->pad, 0xff, 52);

        for (i=0; i<max_virt_disks; i++)
                memset(&vd->entries[i], 0xff, sizeof(struct virtual_entry));

        st->sb = ddf;
        ddf->updates_pending = 1;
        return 1;
}

static int all_ff(char *guid)
{
        int i;
        for (i = 0; i < DDF_GUID_LEN; i++)
                if (guid[i] != (char)0xff)
                        return 0;
        return 1;
}
static int chunk_to_shift(int chunksize)
{
        return ffs(chunksize/512)-1;
}

static int level_to_prl(int level)
{
        switch (level) {
        case LEVEL_LINEAR: return DDF_CONCAT;
        case 0: return DDF_RAID0;
        case 1: return DDF_RAID1;
        case 4: return DDF_RAID4;
        case 5: return DDF_RAID5;
        case 6: return DDF_RAID6;
        default: return -1;
        }
}
static int layout_to_rlq(int level, int layout, int raiddisks)
{
        switch(level) {
        case 0:
                return DDF_RAID0_SIMPLE;
        case 1:
                switch(raiddisks) {
                case 2: return DDF_RAID1_SIMPLE;
                case 3: return DDF_RAID1_MULTI;
                default: return -1;
                }
        case 4:
                switch(layout) {
                case 0: return DDF_RAID4_N;
                }
                break;
        case 5:
        case 6:
                switch(layout) {
                case ALGORITHM_LEFT_ASYMMETRIC:
                        return DDF_RAID5_N_RESTART;
                case ALGORITHM_RIGHT_ASYMMETRIC:
                        if (level == 5)
                                return DDF_RAID5_0_RESTART;
                        else
                                return DDF_RAID6_0_RESTART;
                case ALGORITHM_LEFT_SYMMETRIC:
                        return DDF_RAID5_N_CONTINUE;
                case ALGORITHM_RIGHT_SYMMETRIC:
                        return -1; /* not mentioned in standard */
                }
        }
        return -1;
}

static int rlq_to_layout(int rlq, int prl, int raiddisks)
{
        switch(prl) {
        case DDF_RAID0:
                return 0; /* hopefully rlq == DDF_RAID0_SIMPLE */
        case DDF_RAID1:
                return 0; /* hopefully rlq == SIMPLE or MULTI depending
                             on raiddisks*/
        case DDF_RAID4:
                switch(rlq) {
                case DDF_RAID4_N:
                        return 0;
                default:
                        /* not supported */
                        return -1; /* FIXME this isn't checked */
                }
        case DDF_RAID5:
                switch(rlq) {
                case DDF_RAID5_N_RESTART:
                        return ALGORITHM_LEFT_ASYMMETRIC;
                case DDF_RAID5_0_RESTART:
                        return ALGORITHM_RIGHT_ASYMMETRIC;
                case DDF_RAID5_N_CONTINUE:
                        return ALGORITHM_LEFT_SYMMETRIC;
                default:
                        return -1;
                }
        case DDF_RAID6:
                switch(rlq) {
                case DDF_RAID5_N_RESTART:
                        return ALGORITHM_LEFT_ASYMMETRIC;
                case DDF_RAID6_0_RESTART:
                        return ALGORITHM_RIGHT_ASYMMETRIC;
                case DDF_RAID5_N_CONTINUE:
                        return ALGORITHM_LEFT_SYMMETRIC;
                default:
                        return -1;
                }
        }
        return -1;
}

#ifndef MDASSEMBLE
struct extent {
        unsigned long long start, size;
};
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 struct extent *get_extents(struct ddf_super *ddf, struct dl *dl)
{
        /* find a list of used extents on the give physical device
         * (dnum) of the given ddf.
         * Return a malloced array of 'struct extent'

FIXME ignore DDF_Legacy devices?

         */
        struct extent *rv;
        int n = 0;
        int i, j;

        rv = malloc(sizeof(struct extent) * (ddf->max_part + 2));
        if (!rv)
                return NULL;

        for (i = 0; i < ddf->max_part; i++) {
                struct vcl *v = dl->vlist[i];
                if (v == NULL)
                        continue;
                for (j=0; j < v->conf.prim_elmnt_count; j++)
                        if (v->conf.phys_refnum[j] == dl->disk.refnum) {
                                /* This device plays role 'j' in  'v'. */
                                rv[n].start = __be64_to_cpu(v->lba_offset[j]);
                                rv[n].size = __be64_to_cpu(v->conf.blocks);
                                n++;
                                break;
                        }
        }
        qsort(rv, n, sizeof(*rv), cmp_extent);

        rv[n].start = __be64_to_cpu(ddf->phys->entries[dl->pdnum].config_size);
        rv[n].size = 0;
        return rv;
}
#endif

static int init_super_ddf_bvd(struct supertype *st,
                              mdu_array_info_t *info,
                              unsigned long long size,
                              char *name, char *homehost,
                              int *uuid)
{
        /* We are creating a BVD inside a pre-existing container.
         * so st->sb is already set.
         * We need to create a new vd_config and a new virtual_entry
         */
        struct ddf_super *ddf = st->sb;
        int venum;
        struct virtual_entry *ve;
        struct vcl *vcl;
        struct vd_config *vc;

        if (__be16_to_cpu(ddf->virt->populated_vdes)
            >= __be16_to_cpu(ddf->virt->max_vdes)) {
                fprintf(stderr, Name": This ddf already has the "
                        "maximum of %d virtual devices\n",
                        __be16_to_cpu(ddf->virt->max_vdes));
                return 0;
        }

        for (venum = 0; venum < __be16_to_cpu(ddf->virt->max_vdes); venum++)
                if (all_ff(ddf->virt->entries[venum].guid))
                        break;
        if (venum == __be16_to_cpu(ddf->virt->max_vdes)) {
                fprintf(stderr, Name ": Cannot find spare slot for "
                        "virtual disk - DDF is corrupt\n");
                return 0;
        }
        ve = &ddf->virt->entries[venum];

        /* A Virtual Disk GUID contains the T10 Vendor ID, controller type,
         * timestamp, random number
         */
        make_header_guid(ve->guid);
        ve->unit = __cpu_to_be16(info->md_minor);
        ve->pad0 = 0xFFFF;
        ve->guid_crc = crc32(0, (unsigned char*)ddf->anchor.guid, DDF_GUID_LEN);
        ve->type = 0;
        ve->state = DDF_state_degraded; /* Will be modified as devices are added */
        if (info->state & 1) /* clean */
                ve->init_state = DDF_init_full;
        else
                ve->init_state = DDF_init_not;

        memset(ve->pad1, 0xff, 14);
        memset(ve->name, ' ', 16);
        if (name)
                strncpy(ve->name, name, 16);
        ddf->virt->populated_vdes =
                __cpu_to_be16(__be16_to_cpu(ddf->virt->populated_vdes)+1);

        /* Now create a new vd_config */
        posix_memalign((void**)&vcl, 512,
                       (offsetof(struct vcl, conf) + ddf->conf_rec_len * 512));
        vcl->lba_offset = (__u64*) &vcl->conf.phys_refnum[ddf->mppe];
        vcl->vcnum = venum;
        sprintf(st->subarray, "%d", venum);
        vcl->block_sizes = NULL; /* FIXME not for CONCAT */

        vc = &vcl->conf;

        vc->magic = DDF_VD_CONF_MAGIC;
        memcpy(vc->guid, ve->guid, DDF_GUID_LEN);
        vc->timestamp = __cpu_to_be32(time(0)-DECADE);
        vc->seqnum = __cpu_to_be32(1);
        memset(vc->pad0, 0xff, 24);
        vc->prim_elmnt_count = __cpu_to_be16(info->raid_disks);
        vc->chunk_shift = chunk_to_shift(info->chunk_size);
        vc->prl = level_to_prl(info->level);
        vc->rlq = layout_to_rlq(info->level, info->layout, info->raid_disks);
        vc->sec_elmnt_count = 1;
        vc->sec_elmnt_seq = 0;
        vc->srl = 0;
        vc->blocks = __cpu_to_be64(info->size * 2);
        vc->array_blocks = __cpu_to_be64(
                calc_array_size(info->level, info->raid_disks, info->layout,
                                info->chunk_size, info->size*2));
        memset(vc->pad1, 0xff, 8);
        vc->spare_refs[0] = 0xffffffff;
        vc->spare_refs[1] = 0xffffffff;
        vc->spare_refs[2] = 0xffffffff;
        vc->spare_refs[3] = 0xffffffff;
        vc->spare_refs[4] = 0xffffffff;
        vc->spare_refs[5] = 0xffffffff;
        vc->spare_refs[6] = 0xffffffff;
        vc->spare_refs[7] = 0xffffffff;
        memset(vc->cache_pol, 0, 8);
        vc->bg_rate = 0x80;
        memset(vc->pad2, 0xff, 3);
        memset(vc->pad3, 0xff, 52);
        memset(vc->pad4, 0xff, 192);
        memset(vc->v0, 0xff, 32);
        memset(vc->v1, 0xff, 32);
        memset(vc->v2, 0xff, 16);
        memset(vc->v3, 0xff, 16);
        memset(vc->vendor, 0xff, 32);

        memset(vc->phys_refnum, 0xff, 4*ddf->mppe);
        memset(vc->phys_refnum+(ddf->mppe * 4), 0x00, 8*ddf->mppe);

        vcl->next = ddf->conflist;
        ddf->conflist = vcl;
        ddf->currentconf = vcl;
        ddf->updates_pending = 1;
        return 1;
}

#ifndef MDASSEMBLE
static void add_to_super_ddf_bvd(struct supertype *st,
                                 mdu_disk_info_t *dk, int fd, char *devname)
{
        /* fd and devname identify a device with-in the ddf container (st).
         * dk identifies a location in the new BVD.
         * We need to find suitable free space in that device and update
         * the phys_refnum and lba_offset for the newly created vd_config.
         * We might also want to update the type in the phys_disk
         * section.
         */
        struct dl *dl;
        struct ddf_super *ddf = st->sb;
        struct vd_config *vc;
        __u64 *lba_offset;
        int working;
        int i;
        unsigned long long blocks, pos, esize;
        struct extent *ex;

        for (dl = ddf->dlist; dl ; dl = dl->next)
                if (dl->major == dk->major &&
                    dl->minor == dk->minor)
                        break;
        if (!dl || ! (dk->state & (1<<MD_DISK_SYNC)))
                return;

        vc = &ddf->currentconf->conf;
        lba_offset = ddf->currentconf->lba_offset;

        ex = get_extents(ddf, dl);
        if (!ex)
                return;

        i = 0; pos = 0;
        blocks = __be64_to_cpu(vc->blocks);
        if (ddf->currentconf->block_sizes)
                blocks = ddf->currentconf->block_sizes[dk->raid_disk];

        do {
                esize = ex[i].start - pos;
                if (esize >= blocks)
                        break;
                pos = ex[i].start + ex[i].size;
                i++;
        } while (ex[i-1].size);

        free(ex);
        if (esize < blocks)
                return;

        ddf->currentdev = dk->raid_disk;
        vc->phys_refnum[dk->raid_disk] = dl->disk.refnum;
        lba_offset[dk->raid_disk] = __cpu_to_be64(pos);

        for (i=0; i < ddf->max_part ; i++)
                if (dl->vlist[i] == NULL)
                        break;
        if (i == ddf->max_part)
                return;
        dl->vlist[i] = ddf->currentconf;

        dl->fd = fd;
        dl->devname = devname;

        /* Check how many working raid_disks, and if we can mark
         * array as optimal yet
         */
        working = 0;

        for (i=0; i < __be16_to_cpu(vc->prim_elmnt_count); i++)
                if (vc->phys_refnum[i] != 0xffffffff)
                        working++;

        /* Find which virtual_entry */
        i = ddf->currentconf->vcnum;
        if (working == __be16_to_cpu(vc->prim_elmnt_count))
                ddf->virt->entries[i].state =
                        (ddf->virt->entries[i].state & ~DDF_state_mask)
                        | DDF_state_optimal;

        if (vc->prl == DDF_RAID6 &&
            working+1 == __be16_to_cpu(vc->prim_elmnt_count))
                ddf->virt->entries[i].state =
                        (ddf->virt->entries[i].state & ~DDF_state_mask)
                        | DDF_state_part_optimal;

        ddf->phys->entries[dl->pdnum].type &= ~__cpu_to_be16(DDF_Global_Spare);
        ddf->phys->entries[dl->pdnum].type |= __cpu_to_be16(DDF_Active_in_VD);
        ddf->updates_pending = 1;
}

/* add a device to a container, either while creating it or while
 * expanding a pre-existing container
 */
static void add_to_super_ddf(struct supertype *st,
                             mdu_disk_info_t *dk, int fd, char *devname)
{
        struct ddf_super *ddf = st->sb;
        struct dl *dd;
        time_t now;
        struct tm *tm;
        unsigned long long size;
        struct phys_disk_entry *pde;
        int n, i;
        struct stat stb;

        if (ddf->currentconf) {
                add_to_super_ddf_bvd(st, dk, fd, devname);
                return;
        }

        /* This is device numbered dk->number.  We need to create
         * a phys_disk entry and a more detailed disk_data entry.
         */
        fstat(fd, &stb);
        posix_memalign((void**)&dd, 512,
                       sizeof(*dd) + sizeof(dd->vlist[0]) * ddf->max_part);
        dd->major = major(stb.st_rdev);
        dd->minor = minor(stb.st_rdev);
        dd->devname = devname;
        dd->fd = fd;
        dd->spare = NULL;

        dd->disk.magic = DDF_PHYS_DATA_MAGIC;
        now = time(0);
        tm = localtime(&now);
        sprintf(dd->disk.guid, "%8s%04d%02d%02d",
                T10, tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday);
        *(__u32*)(dd->disk.guid + 16) = random();
        *(__u32*)(dd->disk.guid + 20) = random();

        do {
                /* Cannot be bothered finding a CRC of some irrelevant details*/
                dd->disk.refnum = random();
                for (i = __be16_to_cpu(ddf->active->max_pd_entries) - 1;
                     i >= 0; i--)
                        if (ddf->phys->entries[i].refnum == dd->disk.refnum)
                                break;
        } while (i >= 0);

        dd->disk.forced_ref = 1;
        dd->disk.forced_guid = 1;
        memset(dd->disk.vendor, ' ', 32);
        memcpy(dd->disk.vendor, "Linux", 5);
        memset(dd->disk.pad, 0xff, 442);
        for (i = 0; i < ddf->max_part ; i++)
                dd->vlist[i] = NULL;

        n = __be16_to_cpu(ddf->phys->used_pdes);
        pde = &ddf->phys->entries[n];
        dd->pdnum = n;

        if (st->update_tail) {
                int len = (sizeof(struct phys_disk) +
                           sizeof(struct phys_disk_entry));
                struct phys_disk *pd;

                pd = malloc(len);
                pd->magic = DDF_PHYS_RECORDS_MAGIC;
                pd->used_pdes = __cpu_to_be16(n);
                pde = &pd->entries[0];
                dd->mdupdate = pd;
        } else {
                n++;
                ddf->phys->used_pdes = __cpu_to_be16(n);
        }

        memcpy(pde->guid, dd->disk.guid, DDF_GUID_LEN);
        pde->refnum = dd->disk.refnum;
        pde->type = __cpu_to_be16(DDF_Forced_PD_GUID | DDF_Global_Spare);
        pde->state = __cpu_to_be16(DDF_Online);
        get_dev_size(fd, NULL, &size);
        /* We are required to reserve 32Meg, and record the size in sectors */
        pde->config_size = __cpu_to_be64( (size - 32*1024*1024) / 512);
        sprintf(pde->path, "%17.17s","Information: nil") ;
        memset(pde->pad, 0xff, 6);

        dd->size = size >> 9;
        if (st->update_tail) {
                dd->next = ddf->add_list;
                ddf->add_list = dd;
        } else {
                dd->next = ddf->dlist;
                ddf->dlist = dd;
                ddf->updates_pending = 1;
        }
}

/*
 * This is the write_init_super method for a ddf container.  It is
 * called when creating a container or adding another device to a
 * container.
 */

static unsigned char null_conf[4096+512];

static int __write_init_super_ddf(struct supertype *st, int do_close)
{

        struct ddf_super *ddf = st->sb;
        int i;
        struct dl *d;
        int n_config;
        int conf_size;

        unsigned long long size, sector;

        for (d = ddf->dlist; d; d=d->next) {
                int fd = d->fd;

                if (fd < 0)
                        continue;

                /* We need to fill in the primary, (secondary) and workspace
                 * lba's in the headers, set their checksums,
                 * Also checksum phys, virt....
                 *
                 * Then write everything out, finally the anchor is written.
                 */
                get_dev_size(fd, NULL, &size);
                size /= 512;
                ddf->anchor.workspace_lba = __cpu_to_be64(size - 32*1024*2);
                ddf->anchor.primary_lba = __cpu_to_be64(size - 16*1024*2);
                ddf->anchor.seq = __cpu_to_be32(1);
                memcpy(&ddf->primary, &ddf->anchor, 512);
                memcpy(&ddf->secondary, &ddf->anchor, 512);

                ddf->anchor.openflag = 0xFF; /* 'open' means nothing */
                ddf->anchor.seq = 0xFFFFFFFF; /* no sequencing in anchor */
                ddf->anchor.crc = calc_crc(&ddf->anchor, 512);

                ddf->primary.openflag = 0;
                ddf->primary.type = DDF_HEADER_PRIMARY;

                ddf->secondary.openflag = 0;
                ddf->secondary.type = DDF_HEADER_SECONDARY;

                ddf->primary.crc = calc_crc(&ddf->primary, 512);
                ddf->secondary.crc = calc_crc(&ddf->secondary, 512);

                sector = size - 16*1024*2;
                lseek64(fd, sector<<9, 0);
                write(fd, &ddf->primary, 512);

                ddf->controller.crc = calc_crc(&ddf->controller, 512);
                write(fd, &ddf->controller, 512);

                ddf->phys->crc = calc_crc(ddf->phys, ddf->pdsize);

                write(fd, ddf->phys, ddf->pdsize);

                ddf->virt->crc = calc_crc(ddf->virt, ddf->vdsize);
                write(fd, ddf->virt, ddf->vdsize);

                /* Now write lots of config records. */
                n_config = ddf->max_part;
                conf_size = ddf->conf_rec_len * 512;
                for (i = 0 ; i <= n_config ; i++) {
                        struct vcl *c = d->vlist[i];
                        if (i == n_config)
                                c = (struct vcl*)d->spare;

                        if (c) {
                                c->conf.crc = calc_crc(&c->conf, conf_size);
                                write(fd, &c->conf, conf_size);
                        } else {
                                char *null_aligned = (char*)((((unsigned long)null_conf)+511)&~511UL);
                                if (null_conf[0] != 0xff)
                                        memset(null_conf, 0xff, sizeof(null_conf));
                                int togo = conf_size;
                                while (togo > sizeof(null_conf)-512) {
                                        write(fd, null_aligned, sizeof(null_conf)-512);
                                        togo -= sizeof(null_conf)-512;
                                }
                                write(fd, null_aligned, togo);
                        }
                }
                d->disk.crc = calc_crc(&d->disk, 512);
                write(fd, &d->disk, 512);

                /* Maybe do the same for secondary */

                lseek64(fd, (size-1)*512, SEEK_SET);
                write(fd, &ddf->anchor, 512);
                if (do_close) {
                        close(fd);
                        d->fd = -1;
                }
        }
        return 1;
}

static int write_init_super_ddf(struct supertype *st)
{

        if (st->update_tail) {
                /* queue the virtual_disk and vd_config as metadata updates */
                struct virtual_disk *vd;
                struct vd_config *vc;
                struct ddf_super *ddf = st->sb;
                int len;

                if (!ddf->currentconf) {
                        int len = (sizeof(struct phys_disk) +
                                   sizeof(struct phys_disk_entry));

                        /* adding a disk to the container. */
                        if (!ddf->add_list)
                                return 0;

                        append_metadata_update(st, ddf->add_list->mdupdate, len);
                        ddf->add_list->mdupdate = NULL;
                        return 0;
                }

                /* Newly created VD */

                /* First the virtual disk.  We have a slightly fake header */
                len = sizeof(struct virtual_disk) + sizeof(struct virtual_entry);
                vd = malloc(len);
                *vd = *ddf->virt;
                vd->entries[0] = ddf->virt->entries[ddf->currentconf->vcnum];
                vd->populated_vdes = __cpu_to_be16(ddf->currentconf->vcnum);
                append_metadata_update(st, vd, len);

                /* Then the vd_config */
                len = ddf->conf_rec_len * 512;
                vc = malloc(len);
                memcpy(vc, &ddf->currentconf->conf, len);
                append_metadata_update(st, vc, len);

                /* FIXME I need to close the fds! */
                return 0;
        } else 
                return __write_init_super_ddf(st, 1);
}

#endif

static __u64 avail_size_ddf(struct supertype *st, __u64 devsize)
{
        /* We must reserve the last 32Meg */
        if (devsize <= 32*1024*2)
                return 0;
        return devsize - 32*1024*2;
}

#ifndef MDASSEMBLE
static int
validate_geometry_ddf_container(struct supertype *st,
                                int level, int layout, int raiddisks,
                                int chunk, unsigned long long size,
                                char *dev, unsigned long long *freesize,
                                int verbose);

static int validate_geometry_ddf_bvd(struct supertype *st,
                                     int level, int layout, int raiddisks,
                                     int chunk, unsigned long long size,
                                     char *dev, unsigned long long *freesize,
                                     int verbose);

static int validate_geometry_ddf(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;
        struct mdinfo *sra;
        int cfd;

        /* ddf potentially supports lots of things, but it depends on
         * what devices are offered (and maybe kernel version?)
         * If given unused devices, we will make a container.
         * If given devices in a container, we will make a BVD.
         * If given BVDs, we make an SVD, changing all the GUIDs in the process.
         */

        if (level == LEVEL_CONTAINER) {
                /* Must be a fresh device to add to a container */
                return validate_geometry_ddf_container(st, level, layout,
                                                       raiddisks, chunk,
                                                       size, dev, freesize,
                                                       verbose);
        }

        if (st->sb) {
                /* A container has already been opened, so we are
                 * creating in there.  Maybe a BVD, maybe an SVD.
                 * Should make a distinction one day.
                 */
                return validate_geometry_ddf_bvd(st, level, layout, raiddisks,
                                                 chunk, size, dev, freesize,
                                                 verbose);
        }
        if (!dev) {
                /* Initial sanity check.  Exclude illegal levels. */
                int i;
                for (i=0; ddf_level_num[i].num1 != MAXINT; i++)
                        if (ddf_level_num[i].num2 == level)
                                break;
                if (ddf_level_num[i].num1 == MAXINT)
                        return 0;
                /* Should check layout? etc */
                return 1;
        }

        /* This is the first device for the array.
         * If it is a container, we read it in and do automagic allocations,
         * no other devices should be given.
         * Otherwise it must be a member device of a container, and we
         * do manual allocation.
         * Later we should check for a BVD and make an SVD.
         */
        fd = open(dev, O_RDONLY|O_EXCL, 0);
        if (fd >= 0) {
                sra = sysfs_read(fd, 0, GET_VERSION);
                close(fd);
                if (sra && sra->array.major_version == -1 &&
                    strcmp(sra->text_version, "ddf") == 0) {

                        /* load super */
                        /* find space for 'n' devices. */
                        /* remember the devices */
                        /* Somehow return the fact that we have enough */
                }

                if (verbose)
                        fprintf(stderr,
                                Name ": ddf: Cannot create this array "
                                "on device %s\n",
                                dev);
                return 0;
        }
        if (errno != EBUSY || (fd = open(dev, O_RDONLY, 0)) < 0) {
                if (verbose)
                        fprintf(stderr, Name ": ddf: Cannot open %s: %s\n",
                                dev, strerror(errno));
                return 0;
        }
        /* Well, it is in use by someone, maybe a 'ddf' container. */
        cfd = open_container(fd);
        if (cfd < 0) {
                close(fd);
                if (verbose)
                        fprintf(stderr, Name ": ddf: Cannot use %s: %s\n",
                                dev, strerror(EBUSY));
                return 0;
        }
        sra = sysfs_read(cfd, 0, GET_VERSION);
        close(fd);
        if (sra && sra->array.major_version == -1 &&
            strcmp(sra->text_version, "ddf") == 0) {
                /* This is a member of a ddf container.  Load the container
                 * and try to create a bvd
                 */
                struct ddf_super *ddf;
                if (load_super_ddf_all(st, cfd, (void **)&ddf, NULL, 1) == 0) {
                        st->sb = ddf;
                        st->container_dev = fd2devnum(cfd);
                        close(cfd);
                        return validate_geometry_ddf_bvd(st, level, layout,
                                                         raiddisks, chunk, size,
                                                         dev, freesize,
                                                         verbose);
                }
                close(cfd);
        } else /* device may belong to a different container */
                return 0;

        return 1;
}

static int
validate_geometry_ddf_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;

        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 ": ddf: Cannot open %s: %s\n",
                                dev, strerror(errno));
                return 0;
        }
        if (!get_dev_size(fd, dev, &ldsize)) {
                close(fd);
                return 0;
        }
        close(fd);

        *freesize = avail_size_ddf(st, ldsize >> 9);

        return 1;
}

static int validate_geometry_ddf_bvd(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 ddf_super *ddf = st->sb;
        struct dl *dl;
        unsigned long long pos = 0;
        unsigned long long maxsize;
        struct extent *e;
        int i;
        /* ddf/bvd supports lots of things, but not containers */
        if (level == LEVEL_CONTAINER)
                return 0;
        /* We must have the container info already read in. */
        if (!ddf)
                return 0;

        if (!dev) {
                /* General test:  make sure there is space for
                 * 'raiddisks' device extents of size 'size'.
                 */
                unsigned long long minsize = size;
                int dcnt = 0;
                if (minsize == 0)
                        minsize = 8;
                for (dl = ddf->dlist; dl ; dl = dl->next)
                {
                        int found = 0;
                        pos = 0;

                        i = 0;
                        e = get_extents(ddf, dl);
                        if (!e) continue;
                        do {
                                unsigned long long esize;
                                esize = e[i].start - pos;
                                if (esize >= minsize)
                                        found = 1;
                                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 ": ddf: 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 = ddf->dlist ; dl ; dl = dl->next) {
                if (dl->major == major(stb.st_rdev) &&
                    dl->minor == minor(stb.st_rdev))
                        break;
        }
        if (!dl) {
                if (verbose)
                        fprintf(stderr, Name ": ddf: %s is not in the "
                                "same DDF set\n",
                                dev);
                return 0;
        }
        e = get_extents(ddf, 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);
        *freesize = maxsize;
        // FIXME here I am

        return 1;
}

static int load_super_ddf_all(struct supertype *st, int fd,
                              void **sbp, char *devname, int keep_fd)
{
        struct mdinfo *sra;
        struct ddf_super *super;
        struct mdinfo *sd, *best = NULL;
        int bestseq = 0;
        int seq;
        char nm[20];
        int dfd;

        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, "ddf") != 0)
                return 1;

        if (posix_memalign((void**)&super, 512, sizeof(*super)) != 0)
                return 1;
        memset(super, 0, sizeof(*super));

        /* first, try each device, and choose the best ddf */
        for (sd = sra->devs ; sd ; sd = sd->next) {
                int rv;
                sprintf(nm, "%d:%d", sd->disk.major, sd->disk.minor);
                dfd = dev_open(nm, O_RDONLY);
                if (dfd < 0)
                        return 2;
                rv = load_ddf_headers(dfd, super, NULL);
                close(dfd);
                if (rv == 0) {
                        seq = __be32_to_cpu(super->active->seq);
                        if (super->active->openflag)
                                seq--;
                        if (!best || seq > bestseq) {
                                bestseq = seq;
                                best = sd;
                        }
                }
        }
        if (!best)
                return 1;
        /* OK, load this ddf */
        sprintf(nm, "%d:%d", best->disk.major, best->disk.minor);
        dfd = dev_open(nm, O_RDONLY);
        if (dfd < 0)
                return 1;
        load_ddf_headers(dfd, super, NULL);
        load_ddf_global(dfd, super, NULL);
        close(dfd);
        /* Now we need the device-local bits */
        for (sd = sra->devs ; sd ; sd = sd->next) {
                sprintf(nm, "%d:%d", sd->disk.major, sd->disk.minor);
                dfd = dev_open(nm, keep_fd? O_RDWR : O_RDONLY);
                if (dfd < 0)
                        return 2;
                load_ddf_headers(dfd, super, NULL);
                seq = load_ddf_local(dfd, super, NULL, keep_fd);
                if (!keep_fd) close(dfd);
        }
        if (st->subarray[0]) {
                struct vcl *v;

                for (v = super->conflist; v; v = v->next)
                        if (v->vcnum == atoi(st->subarray))
                                super->currentconf = v;
                if (!super->currentconf)
                        return 1;
        }
        *sbp = super;
        if (st->ss == NULL) {
                st->ss = &super_ddf;
                st->minor_version = 0;
                st->max_devs = 512;
                st->container_dev = fd2devnum(fd);
        }
        return 0;
}
#endif /* MDASSEMBLE */

static struct mdinfo *container_content_ddf(struct supertype *st)
{
        /* Given a container loaded by load_super_ddf_all,
         * extract information about all the arrays into
         * an mdinfo tree.
         *
         * For each vcl in conflist: create an mdinfo, fill it in,
         *  then look for matching devices (phys_refnum) in dlist
         *  and create appropriate device mdinfo.
         */
        struct ddf_super *ddf = st->sb;
        struct mdinfo *rest = NULL;
        struct vcl *vc;

        for (vc = ddf->conflist ; vc ; vc=vc->next)
        {
                int i;
                struct mdinfo *this;
                this = malloc(sizeof(*this));
                memset(this, 0, sizeof(*this));
                this->next = rest;
                rest = this;

                this->array.level = map_num1(ddf_level_num, vc->conf.prl);
                this->array.raid_disks =
                        __be16_to_cpu(vc->conf.prim_elmnt_count);
                this->array.layout = rlq_to_layout(vc->conf.rlq, vc->conf.prl,
                                                   this->array.raid_disks);
                this->array.md_minor      = -1;
                this->array.major_version = -1;
                this->array.minor_version = -2;
                this->array.ctime         = DECADE +
                        __be32_to_cpu(*(__u32*)(vc->conf.guid+16));
                this->array.utime         = DECADE +
                        __be32_to_cpu(vc->conf.timestamp);
                this->array.chunk_size    = 512 << vc->conf.chunk_shift;

                i = vc->vcnum;
                if ((ddf->virt->entries[i].state & DDF_state_inconsistent) ||
                    (ddf->virt->entries[i].init_state & DDF_initstate_mask) !=
                    DDF_init_full) {
                        this->array.state = 0;
                        this->resync_start = 0;
                } else {
                        this->array.state = 1;
                        this->resync_start = ~0ULL;
                }
                memcpy(this->name, ddf->virt->entries[i].name, 32);
                this->name[32]=0;

                memset(this->uuid, 0, sizeof(this->uuid));
                this->component_size = __be64_to_cpu(vc->conf.blocks);
                this->array.size = this->component_size / 2;
                this->container_member = i;

                sprintf(this->text_version, "/%s/%d",
                        devnum2devname(st->container_dev),
                        this->container_member);

                for (i=0 ; i < ddf->mppe ; i++) {
                        struct mdinfo *dev;
                        struct dl *d;

                        if (vc->conf.phys_refnum[i] == 0xFFFFFFFF)
                                continue;

                        this->array.working_disks++;

                        for (d = ddf->dlist; d ; d=d->next)
                                if (d->disk.refnum == vc->conf.phys_refnum[i])
                                        break;
                        if (d == NULL)
                                break;

                        dev = malloc(sizeof(*dev));
                        memset(dev, 0, sizeof(*dev));
                        dev->next = this->devs;
                        this->devs = dev;

                        dev->disk.number = __be32_to_cpu(d->disk.refnum);
                        dev->disk.major = d->major;
                        dev->disk.minor = d->minor;
                        dev->disk.raid_disk = i;
                        dev->disk.state = (1<<MD_DISK_SYNC)|(1<<MD_DISK_ACTIVE);

                        dev->events = __be32_to_cpu(ddf->primary.seq);
                        dev->data_offset = __be64_to_cpu(vc->lba_offset[i]);
                        dev->component_size = __be64_to_cpu(vc->conf.blocks);
                        if (d->devname)
                                strcpy(dev->name, d->devname);
                }
        }
        return rest;
}

static int store_zero_ddf(struct supertype *st, int fd)
{
        unsigned long long dsize;
        void *buf;

        if (!get_dev_size(fd, NULL, &dsize))
                return 1;

        posix_memalign(&buf, 512, 512);
        memset(buf, 0, 512);

        lseek64(fd, dsize-512, 0);
        write(fd, buf, 512);
        free(buf);
        return 0;
}

static int compare_super_ddf(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 ddf_super *first = st->sb;
        struct ddf_super *second = tst->sb;

        if (!first) {
                st->sb = tst->sb;
                tst->sb = NULL;
                return 0;
        }

        if (memcmp(first->anchor.guid, second->anchor.guid, DDF_GUID_LEN) != 0)
                return 2;

        /* FIXME should I look at anything else? */
        return 0;
}

#ifndef MDASSEMBLE
/*
 * A new array 'a' has been started which claims to be instance 'inst'
 * within container 'c'.
 * We need to confirm that the array matches the metadata in 'c' so
 * that we don't corrupt any metadata.
 */
static int ddf_open_new(struct supertype *c, struct active_array *a, char *inst)
{
        dprintf("ddf: open_new %s\n", inst);
        a->info.container_member = atoi(inst);
        return 0;
}

/*
 * The array 'a' is to be marked clean in the metadata.
 * If '->resync_start' is not ~(unsigned long long)0, then the array is only
 * clean up to the point (in sectors).  If that cannot be recorded in the
 * metadata, then leave it as dirty.
 *
 * For DDF, we need to clear the DDF_state_inconsistent bit in the
 * !global! virtual_disk.virtual_entry structure.
 */
static int ddf_set_array_state(struct active_array *a, int consistent)
{
        struct ddf_super *ddf = a->container->sb;
        int inst = a->info.container_member;
        int old = ddf->virt->entries[inst].state;
        if (consistent == 2) {
                /* Should check if a recovery should be started FIXME */
                consistent = 1;
                if (a->resync_start != ~0ULL)
                        consistent = 0;
        }
        if (consistent)
                ddf->virt->entries[inst].state &= ~DDF_state_inconsistent;
        else
                ddf->virt->entries[inst].state |= DDF_state_inconsistent;
        if (old != ddf->virt->entries[inst].state)
                ddf->updates_pending = 1;

        old = ddf->virt->entries[inst].init_state;
        ddf->virt->entries[inst].init_state &= ~DDF_initstate_mask;
        if (a->resync_start == ~0ULL)
                ddf->virt->entries[inst].init_state |= DDF_init_full;
        else if (a->resync_start == 0)
                ddf->virt->entries[inst].init_state |= DDF_init_not;
        else
                ddf->virt->entries[inst].init_state |= DDF_init_quick;
        if (old != ddf->virt->entries[inst].init_state)
                ddf->updates_pending = 1;

        dprintf("ddf mark %d %s %llu\n", inst, consistent?"clean":"dirty",
                a->resync_start);
        return consistent;
}

/*
 * The state of each disk is stored in the global phys_disk structure
 * in phys_disk.entries[n].state.
 * This makes various combinations awkward.
 * - When a device fails in any array, it must be failed in all arrays
 *   that include a part of this device.
 * - When a component is rebuilding, we cannot include it officially in the
 *   array unless this is the only array that uses the device.
 *
 * So: when transitioning:
 *   Online -> failed,  just set failed flag.  monitor will propagate
 *   spare -> online,   the device might need to be added to the array.
 *   spare -> failed,   just set failed.  Don't worry if in array or not.
 */
static void ddf_set_disk(struct active_array *a, int n, int state)
{
        struct ddf_super *ddf = a->container->sb;
        int inst = a->info.container_member;
        struct vd_config *vc = find_vdcr(ddf, inst);
        int pd = find_phys(ddf, vc->phys_refnum[n]);
        int i, st, working;

        if (vc == NULL) {
                dprintf("ddf: cannot find instance %d!!\n", inst);
                return;
        }
        if (pd < 0) {
                /* disk doesn't currently exist. If it is now in_sync,
                 * insert it. */
                if ((state & DS_INSYNC) && ! (state & DS_FAULTY)) {
                        /* Find dev 'n' in a->info->devs, determine the
                         * ddf refnum, and set vc->phys_refnum and update
                         * phys->entries[]
                         */
                        /* FIXME */
                }
        } else {
                int old = ddf->phys->entries[pd].state;
                if (state & DS_FAULTY)
                        ddf->phys->entries[pd].state  |= __cpu_to_be16(DDF_Failed);
                if (state & DS_INSYNC) {
                        ddf->phys->entries[pd].state  |= __cpu_to_be16(DDF_Online);
                        ddf->phys->entries[pd].state  &= __cpu_to_be16(~DDF_Rebuilding);
                }
                if (old != ddf->phys->entries[pd].state)
                        ddf->updates_pending = 1;
        }

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

        /* Now we need to check the state of the array and update
         * virtual_disk.entries[n].state.
         * It needs to be one of "optimal", "degraded", "failed".
         * I don't understand 'deleted' or 'missing'.
         */
        working = 0;
        for (i=0; i < a->info.array.raid_disks; i++) {
                pd = find_phys(ddf, vc->phys_refnum[i]);
                if (pd < 0)
                        continue;
                st = __be16_to_cpu(ddf->phys->entries[pd].state);
                if ((st & (DDF_Online|DDF_Failed|DDF_Rebuilding))
                    == DDF_Online)
                        working++;
        }
        state = DDF_state_degraded;
        if (working == a->info.array.raid_disks)
                state = DDF_state_optimal;
        else switch(vc->prl) {
        case DDF_RAID0:
        case DDF_CONCAT:
        case DDF_JBOD:
                state = DDF_state_failed;
                break;
        case DDF_RAID1:
                if (working == 0)
                        state = DDF_state_failed;
                break;
        case DDF_RAID4:
        case DDF_RAID5:
                if (working < a->info.array.raid_disks-1)
                        state = DDF_state_failed;
                break;
        case DDF_RAID6:
                if (working < a->info.array.raid_disks-2)
                        state = DDF_state_failed;
                else if (working == a->info.array.raid_disks-1)
                        state = DDF_state_part_optimal;
                break;
        }

        if (ddf->virt->entries[inst].state !=
            ((ddf->virt->entries[inst].state & ~DDF_state_mask)
             | state)) {

                ddf->virt->entries[inst].state =
                        (ddf->virt->entries[inst].state & ~DDF_state_mask)
                        | state;
                ddf->updates_pending = 1;
        }

}

static void ddf_sync_metadata(struct supertype *st)
{

        /*
         * Write all data to all devices.
         * Later, we might be able to track whether only local changes
         * have been made, or whether any global data has been changed,
         * but ddf is sufficiently weird that it probably always
         * changes global data ....
         */
        struct ddf_super *ddf = st->sb;
        if (!ddf->updates_pending)
                return;
        ddf->updates_pending = 0;
        __write_init_super_ddf(st, 0);
        dprintf("ddf: sync_metadata\n");
}

static void ddf_process_update(struct supertype *st,
                               struct metadata_update *update)
{
        /* Apply this update to the metadata.
         * The first 4 bytes are a DDF_*_MAGIC which guides
         * our actions.
         * Possible update are:
         *  DDF_PHYS_RECORDS_MAGIC
         *    Add a new physical device.  Changes to this record
         *    only happen implicitly.
         *    used_pdes is the device number.
         *  DDF_VIRT_RECORDS_MAGIC
         *    Add a new VD.  Possibly also change the 'access' bits.
         *    populated_vdes is the entry number.
         *  DDF_VD_CONF_MAGIC
         *    New or updated VD.  the VIRT_RECORD must already
         *    exist.  For an update, phys_refnum and lba_offset
         *    (at least) are updated, and the VD_CONF must
         *    be written to precisely those devices listed with
         *    a phys_refnum.
         *  DDF_SPARE_ASSIGN_MAGIC
         *    replacement Spare Assignment Record... but for which device?
         *
         * So, e.g.:
         *  - to create a new array, we send a VIRT_RECORD and
         *    a VD_CONF.  Then assemble and start the array.
         *  - to activate a spare we send a VD_CONF to add the phys_refnum
         *    and offset.  This will also mark the spare as active with
         *    a spare-assignment record.
         */
        struct ddf_super *ddf = st->sb;
        __u32 *magic = (__u32*)update->buf;
        struct phys_disk *pd;
        struct virtual_disk *vd;
        struct vd_config *vc;
        struct vcl *vcl;
        struct dl *dl;
        int mppe;
        int ent;

        dprintf("Process update %x\n", *magic);

        switch (*magic) {
        case DDF_PHYS_RECORDS_MAGIC:

                if (update->len != (sizeof(struct phys_disk) +
                                    sizeof(struct phys_disk_entry)))
                        return;
                pd = (struct phys_disk*)update->buf;

                ent = __be16_to_cpu(pd->used_pdes);
                if (ent >= __be16_to_cpu(ddf->phys->max_pdes))
                        return;
                if (!all_ff(ddf->phys->entries[ent].guid))
                        return;
                ddf->phys->entries[ent] = pd->entries[0];
                ddf->phys->used_pdes = __cpu_to_be16(1 +
                                           __be16_to_cpu(ddf->phys->used_pdes));
                ddf->updates_pending = 1;
                if (ddf->add_list) {
                        struct active_array *a;
                        struct dl *al = ddf->add_list;
                        ddf->add_list = al->next;

                        al->next = ddf->dlist;
                        ddf->dlist = al;

                        /* As a device has been added, we should check
                         * for any degraded devices that might make
                         * use of this spare */
                        for (a = st->arrays ; a; a=a->next)
                                a->check_degraded = 1;
                }
                break;

        case DDF_VIRT_RECORDS_MAGIC:

                if (update->len != (sizeof(struct virtual_disk) +
                                    sizeof(struct virtual_entry)))
                        return;
                vd = (struct virtual_disk*)update->buf;

                ent = __be16_to_cpu(vd->populated_vdes);
                if (ent >= __be16_to_cpu(ddf->virt->max_vdes))
                        return;
                if (!all_ff(ddf->virt->entries[ent].guid))
                        return;
                ddf->virt->entries[ent] = vd->entries[0];
                ddf->virt->populated_vdes = __cpu_to_be16(1 +
                              __be16_to_cpu(ddf->virt->populated_vdes));
                ddf->updates_pending = 1;
                break;

        case DDF_VD_CONF_MAGIC:
                dprintf("len %d %d\n", update->len, ddf->conf_rec_len);

                mppe = __be16_to_cpu(ddf->anchor.max_primary_element_entries);
                if (update->len != ddf->conf_rec_len * 512)
                        return;
                vc = (struct vd_config*)update->buf;
                for (vcl = ddf->conflist; vcl ; vcl = vcl->next)
                        if (memcmp(vcl->conf.guid, vc->guid, DDF_GUID_LEN) == 0)
                                break;
                dprintf("vcl = %p\n", vcl);
                if (vcl) {
                        /* An update, just copy the phys_refnum and lba_offset
                         * fields
                         */
                        memcpy(vcl->conf.phys_refnum, vc->phys_refnum,
                               mppe * (sizeof(__u32) + sizeof(__u64)));
                } else {
                        /* A new VD_CONF */
                        vcl = update->space;
                        update->space = NULL;
                        vcl->next = ddf->conflist;
                        memcpy(&vcl->conf, vc, update->len);
                        vcl->lba_offset = (__u64*)
                                &vcl->conf.phys_refnum[mppe];
                        ddf->conflist = vcl;
                }
                /* Now make sure vlist is correct for each dl. */
                for (dl = ddf->dlist; dl; dl = dl->next) {
                        int dn;
                        int vn = 0;
                        for (vcl = ddf->conflist; vcl ; vcl = vcl->next)
                                for (dn=0; dn < ddf->mppe ; dn++)
                                        if (vcl->conf.phys_refnum[dn] ==
                                            dl->disk.refnum) {
                                                dprintf("dev %d has %p at %d\n",
                                                        dl->pdnum, vcl, vn);
                                                dl->vlist[vn++] = vcl;
                                                break;
                                        }
                        while (vn < ddf->max_part)
                                dl->vlist[vn++] = NULL;
                        if (dl->vlist[0]) {
                                ddf->phys->entries[dl->pdnum].type &=
                                        ~__cpu_to_be16(DDF_Global_Spare);
                                ddf->phys->entries[dl->pdnum].type |=
                                        __cpu_to_be16(DDF_Active_in_VD);
                        }
                        if (dl->spare) {
                                ddf->phys->entries[dl->pdnum].type &=
                                        ~__cpu_to_be16(DDF_Global_Spare);
                                ddf->phys->entries[dl->pdnum].type |=
                                        __cpu_to_be16(DDF_Spare);
                        }
                        if (!dl->vlist[0] && !dl->spare) {
                                ddf->phys->entries[dl->pdnum].type |=
                                        __cpu_to_be16(DDF_Global_Spare);
                                ddf->phys->entries[dl->pdnum].type &=
                                        ~__cpu_to_be16(DDF_Spare |
                                                       DDF_Active_in_VD);
                        }
                }
                ddf->updates_pending = 1;
                break;
        case DDF_SPARE_ASSIGN_MAGIC:
        default: break;
        }
}

static void ddf_prepare_update(struct supertype *st,
                               struct metadata_update *update)
{
        /* This update arrived at managemon.
         * We are about to pass it to monitor.
         * If a malloc is needed, do it here.
         */
        struct ddf_super *ddf = st->sb;
        __u32 *magic = (__u32*)update->buf;
        if (*magic == DDF_VD_CONF_MAGIC)
                posix_memalign(&update->space, 512,
                               offsetof(struct vcl, conf)
                               + ddf->conf_rec_len * 512);
}

/*
 * Check if the array 'a' is degraded but not failed.
 * If it is, find as many spares as are available and needed and
 * arrange for their inclusion.
 * We only choose devices which are not already in the array,
 * and prefer those with a spare-assignment to this array.
 * otherwise we choose global spares - assuming always that
 * there is enough room.
 * For each spare that we assign, we return an 'mdinfo' which
 * describes the position for the device in the array.
 * We also add to 'updates' a DDF_VD_CONF_MAGIC update with
 * the new phys_refnum and lba_offset values.
 *
 * Only worry about BVDs at the moment.
 */
static struct mdinfo *ddf_activate_spare(struct active_array *a,
                                         struct metadata_update **updates)
{
        int working = 0;
        struct mdinfo *d;
        struct ddf_super *ddf = a->container->sb;
        int global_ok = 0;
        struct mdinfo *rv = NULL;
        struct mdinfo *di;
        struct metadata_update *mu;
        struct dl *dl;
        int i;
        struct vd_config *vc;
        __u64 *lba;

        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)
                        working ++;
        }

        dprintf("ddf_activate: working=%d (%d) level=%d\n", working, a->info.array.raid_disks,
                a->info.array.level);
        if (working == a->info.array.raid_disks)
                return NULL; /* array not degraded */
        switch (a->info.array.level) {
        case 1:
                if (working == 0)
                        return NULL; /* failed */
                break;
        case 4:
        case 5:
                if (working < a->info.array.raid_disks - 1)
                        return NULL; /* failed */
                break;
        case 6:
                if (working < a->info.array.raid_disks - 2)
                        return NULL; /* failed */
                break;
        default: /* concat or stripe */
                return NULL; /* failed */
        }

        /* For each slot, if it is not working, find a spare */
        dl = ddf->dlist;
        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.  Find a spare */
        again:
                for ( ; dl ; dl = dl->next) {
                        unsigned long long esize;
                        unsigned long long pos;
                        struct mdinfo *d2;
                        int is_global = 0;
                        int is_dedicated = 0;
                        struct extent *ex;
                        int j;
                        /* If in this array, skip */
                        for (d2 = a->info.devs ; d2 ; d2 = d2->next)
                                if (d2->disk.major == dl->major &&
                                    d2->disk.minor == dl->minor) {
                                        dprintf("%x:%x already in array\n", dl->major, dl->minor);
                                        break;
                                }
                        if (d2)
                                continue;
                        if (ddf->phys->entries[dl->pdnum].type &
                            __cpu_to_be16(DDF_Spare)) {
                                /* Check spare assign record */
                                if (dl->spare) {
                                        if (dl->spare->type & DDF_spare_dedicated) {
                                                /* check spare_ents for guid */
                                                for (j = 0 ;
                                                     j < __be16_to_cpu(dl->spare->populated);
                                                     j++) {
                                                        if (memcmp(dl->spare->spare_ents[j].guid,
                                                                   ddf->virt->entries[a->info.container_member].guid,
                                                                   DDF_GUID_LEN) == 0)
                                                                is_dedicated = 1;
                                                }
                                        } else
                                                is_global = 1;
                                }
                        } else if (ddf->phys->entries[dl->pdnum].type &
                                   __cpu_to_be16(DDF_Global_Spare)) {
                                is_global = 1;
                        }
                        if ( ! (is_dedicated ||
                                (is_global && global_ok))) {
                                dprintf("%x:%x not suitable: %d %d\n", dl->major, dl->minor,
                                       is_dedicated, is_global);
                                continue;
                        }

                        /* We are allowed to use this device - is there space?
                         * We need a->info.component_size sectors */
                        ex = get_extents(ddf, dl);
                        if (!ex) {
                                dprintf("cannot get extents\n");
                                continue;
                        }
                        j = 0; pos = 0;
                        esize = 0;

                        do {
                                esize = ex[j].start - pos;
                                if (esize >= a->info.component_size)
                                        break;
                                pos = ex[i].start + ex[i].size;
                                i++;
                        } while (ex[i-1].size);

                        free(ex);
                        if (esize < a->info.component_size) {
                                dprintf("%x:%x has no room: %llu %llu\n", dl->major, dl->minor,
                                        esize, a->info.component_size);
                                /* No room */
                                continue;
                        }

                        /* Cool, we have a device with some space at pos */
                        di = malloc(sizeof(*di));
                        memset(di, 0, sizeof(*di));
                        di->disk.number = i;
                        di->disk.raid_disk = i;
                        di->disk.major = dl->major;
                        di->disk.minor = dl->minor;
                        di->disk.state = 0;
                        di->data_offset = pos;
                        di->component_size = a->info.component_size;
                        di->container_member = dl->pdnum;
                        di->next = rv;
                        rv = di;
                        dprintf("%x:%x to be %d at %llu\n", dl->major, dl->minor,
                                i, pos);

                        break;
                }
                if (!dl && ! global_ok) {
                        /* not enough dedicated spares, try global */
                        global_ok = 1;
                        dl = ddf->dlist;
                        goto again;
                }
        }

        if (!rv)
                /* No spares found */
                return rv;
        /* Now 'rv' has a list of devices to return.
         * Create a metadata_update record to update the
         * phys_refnum and lba_offset values
         */
        mu = malloc(sizeof(*mu));
        mu->buf = malloc(ddf->conf_rec_len * 512);
        posix_memalign(&mu->space, 512, sizeof(struct vcl));
        mu->len = ddf->conf_rec_len;
        mu->next = *updates;
        vc = find_vdcr(ddf, a->info.container_member);
        memcpy(mu->buf, vc, ddf->conf_rec_len * 512);

        vc = (struct vd_config*)mu->buf;
        lba = (__u64*)&vc->phys_refnum[ddf->mppe];
        for (di = rv ; di ; di = di->next) {
                vc->phys_refnum[di->disk.raid_disk] =
                        ddf->phys->entries[dl->pdnum].refnum;
                lba[di->disk.raid_disk] = di->data_offset;
        }
        *updates = mu;
        return rv;
}
#endif /* MDASSEMBLE */

struct superswitch super_ddf = {
#ifndef MDASSEMBLE
        .examine_super  = examine_super_ddf,
        .brief_examine_super = brief_examine_super_ddf,
        .detail_super   = detail_super_ddf,
        .brief_detail_super = brief_detail_super_ddf,
        .validate_geometry = validate_geometry_ddf,
        .write_init_super = write_init_super_ddf,
        .add_to_super   = add_to_super_ddf,
#endif
        .match_home     = match_home_ddf,
        .uuid_from_super= uuid_from_super_ddf,
        .getinfo_super  = getinfo_super_ddf,
        .update_super   = update_super_ddf,

        .avail_size     = avail_size_ddf,

        .compare_super  = compare_super_ddf,

        .load_super     = load_super_ddf,
        .init_super     = init_super_ddf,
        .store_super    = store_zero_ddf,
        .free_super     = free_super_ddf,
        .match_metadata_desc = match_metadata_desc_ddf,
        .container_content = container_content_ddf,

        .external       = 1,

#ifndef MDASSEMBLE
/* for mdmon */
        .open_new       = ddf_open_new,
        .set_array_state= ddf_set_array_state,
        .set_disk       = ddf_set_disk,
        .sync_metadata  = ddf_sync_metadata,
        .process_update = ddf_process_update,
        .prepare_update = ddf_prepare_update,
        .activate_spare = ddf_activate_spare,
#endif
};