Assemble: allow --update=revert-reshape

[thirdparty/mdadm.git] / super1.c

/*
 * mdadm - manage Linux "md" devices aka RAID arrays.
 *
 * Copyright (C) 2001-2009 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: <neilb@suse.de>
 */

#include "mdadm.h"
/*
 * The version-1 superblock :
 * All numeric fields are little-endian.
 *
 * total size: 256 bytes plus 2 per device.
 *  1K allows 384 devices.
 */
struct mdp_superblock_1 {
        /* constant array information - 128 bytes */
        __u32   magic;          /* MD_SB_MAGIC: 0xa92b4efc - little endian */
        __u32   major_version;  /* 1 */
        __u32   feature_map;    /* 0 for now */
        __u32   pad0;           /* always set to 0 when writing */

        __u8    set_uuid[16];   /* user-space generated. */
        char    set_name[32];   /* set and interpreted by user-space */

        __u64   ctime;          /* lo 40 bits are seconds, top 24 are microseconds or 0*/
        __u32   level;          /* -4 (multipath), -1 (linear), 0,1,4,5 */
        __u32   layout;         /* only for raid5 currently */
        __u64   size;           /* used size of component devices, in 512byte sectors */

        __u32   chunksize;      /* in 512byte sectors */
        __u32   raid_disks;
        __u32   bitmap_offset;  /* sectors after start of superblock that bitmap starts
                                 * NOTE: signed, so bitmap can be before superblock
                                 * only meaningful of feature_map[0] is set.
                                 */

        /* These are only valid with feature bit '4' */
        __u32   new_level;      /* new level we are reshaping to                */
        __u64   reshape_position;       /* next address in array-space for reshape */
        __u32   delta_disks;    /* change in number of raid_disks               */
        __u32   new_layout;     /* new layout                                   */
        __u32   new_chunk;      /* new chunk size (bytes)                       */
        __u32   new_offset;     /* signed number to add to data_offset in new
                                 * layout.  0 == no-change.  This can be
                                 * different on each device in the array.
                                 */

        /* constant this-device information - 64 bytes */
        __u64   data_offset;    /* sector start of data, often 0 */
        __u64   data_size;      /* sectors in this device that can be used for data */
        __u64   super_offset;   /* sector start of this superblock */
        __u64   recovery_offset;/* sectors before this offset (from data_offset) have been recovered */
        __u32   dev_number;     /* permanent identifier of this  device - not role in raid */
        __u32   cnt_corrected_read; /* number of read errors that were corrected by re-writing */
        __u8    device_uuid[16]; /* user-space setable, ignored by kernel */
        __u8    devflags;        /* per-device flags.  Only one defined...*/
#define WriteMostly1    1        /* mask for writemostly flag in above */
        /* bad block log.  If there are any bad blocks the feature flag is set.
         * if offset and size are non-zero, that space is reserved and available.
         */
        __u8    bblog_shift;    /* shift from sectors to block size for badblocklist */
        __u16   bblog_size;     /* number of sectors reserved for badblocklist */
        __u32   bblog_offset;   /* sector offset from superblock to bblog, signed */

        /* array state information - 64 bytes */
        __u64   utime;          /* 40 bits second, 24 btes microseconds */
        __u64   events;         /* incremented when superblock updated */
        __u64   resync_offset;  /* data before this offset (from data_offset) known to be in sync */
        __u32   sb_csum;        /* checksum upto dev_roles[max_dev] */
        __u32   max_dev;        /* size of dev_roles[] array to consider */
        __u8    pad3[64-32];    /* set to 0 when writing */

        /* device state information. Indexed by dev_number.
         * 2 bytes per device
         * Note there are no per-device state flags. State information is rolled
         * into the 'roles' value.  If a device is spare or faulty, then it doesn't
         * have a meaningful role.
         */
        __u16   dev_roles[0];   /* role in array, or 0xffff for a spare, or 0xfffe for faulty */
};

#define MAX_SB_SIZE 4096
/* bitmap super size is 256, but we round up to a sector for alignment */
#define BM_SUPER_SIZE 512
#define MAX_DEVS ((int)(MAX_SB_SIZE - sizeof(struct mdp_superblock_1)) / 2)
#define SUPER1_SIZE     (MAX_SB_SIZE + BM_SUPER_SIZE \
                         + sizeof(struct misc_dev_info))

struct misc_dev_info {
        __u64 device_size;
};

/* feature_map bits */
#define MD_FEATURE_BITMAP_OFFSET        1
#define MD_FEATURE_RECOVERY_OFFSET      2 /* recovery_offset is present and
                                           * must be honoured
                                           */
#define MD_FEATURE_RESHAPE_ACTIVE       4
#define MD_FEATURE_BAD_BLOCKS           8 /* badblock list is not empty */
#define MD_FEATURE_REPLACEMENT          16 /* This device is replacing an
                                            * active device with same 'role'.
                                            * 'recovery_offset' is also set.
                                            */
#define MD_FEATURE_RESHAPE_BACKWARDS    32 /* Reshape doesn't change number
                                            * of devices, but is going
                                            * backwards anyway.
                                            */
#define MD_FEATURE_NEW_OFFSET           64 /* new_offset must be honoured */
#define MD_FEATURE_ALL                  (MD_FEATURE_BITMAP_OFFSET       \
                                        |MD_FEATURE_RECOVERY_OFFSET     \
                                        |MD_FEATURE_RESHAPE_ACTIVE      \
                                        |MD_FEATURE_BAD_BLOCKS          \
                                        |MD_FEATURE_REPLACEMENT         \
                                        |MD_FEATURE_RESHAPE_BACKWARDS   \
                                        |MD_FEATURE_NEW_OFFSET          \
                                        )

#ifndef offsetof
#define offsetof(t,f) ((size_t)&(((t*)0)->f))
#endif
static unsigned int calc_sb_1_csum(struct mdp_superblock_1 * sb)
{
        unsigned int disk_csum, csum;
        unsigned long long newcsum;
        int size = sizeof(*sb) + __le32_to_cpu(sb->max_dev)*2;
        unsigned int *isuper = (unsigned int*)sb;

/* make sure I can count... */
        if (offsetof(struct mdp_superblock_1,data_offset) != 128 ||
            offsetof(struct mdp_superblock_1, utime) != 192 ||
            sizeof(struct mdp_superblock_1) != 256) {
                fprintf(stderr, "WARNING - superblock isn't sized correctly\n");
        }

        disk_csum = sb->sb_csum;
        sb->sb_csum = 0;
        newcsum = 0;
        for (; size>=4; size -= 4 ) {
                newcsum += __le32_to_cpu(*isuper);
                isuper++;
        }

        if (size == 2)
                newcsum += __le16_to_cpu(*(unsigned short*) isuper);

        csum = (newcsum & 0xffffffff) + (newcsum >> 32);
        sb->sb_csum = disk_csum;
        return __cpu_to_le32(csum);
}

/*
 * Information related to file descriptor used for aligned reads/writes.
 * Cache the block size.
 */
struct align_fd {
        int fd;
        int blk_sz;
};

static void init_afd(struct align_fd *afd, int fd)
{
        afd->fd = fd;

        if (ioctl(afd->fd, BLKSSZGET, &afd->blk_sz) != 0)
                afd->blk_sz = 512;
}

static char abuf[4096+4096];
static int aread(struct align_fd *afd, void *buf, int len)
{
        /* aligned read.
         * On devices with a 4K sector size, we need to read
         * the full sector and copy relevant bits into
         * the buffer
         */
        int bsize, iosize;
        char *b;
        int n;

        bsize = afd->blk_sz;

        if (!bsize || bsize > 4096 || len > 4096) {
                if (!bsize)
                        fprintf(stderr, "WARNING - aread() called with "
                                "invalid block size\n");
                return -1;
        }
        b = ROUND_UP_PTR((char *)abuf, 4096);

        for (iosize = 0; iosize < len; iosize += bsize)
                ;
        n = read(afd->fd, b, iosize);
        if (n <= 0)
                return n;
        lseek(afd->fd, len - n, 1);
        if (n > len)
                n = len;
        memcpy(buf, b, n);
        return n;
}

static int awrite(struct align_fd *afd, void *buf, int len)
{
        /* aligned write.
         * On devices with a 4K sector size, we need to write
         * the full sector.  We pre-read if the sector is larger
         * than the write.
         * The address must be sector-aligned.
         */
        int bsize, iosize;
        char *b;
        int n;

        bsize = afd->blk_sz;
        if (!bsize || bsize > 4096 || len > 4096) {
                if (!bsize)
                        fprintf(stderr, "WARNING - awrite() called with "
                                "invalid block size\n");
                return -1;
        }
        b = ROUND_UP_PTR((char *)abuf, 4096);

        for (iosize = 0; iosize < len ; iosize += bsize)
                ;

        if (len != iosize) {
                n = read(afd->fd, b, iosize);
                if (n <= 0)
                        return n;
                lseek(afd->fd, -n, 1);
        }

        memcpy(b, buf, len);
        n = write(afd->fd, b, iosize);
        if (n <= 0)
                return n;
        lseek(afd->fd, len - n, 1);
        return len;
}

#ifndef MDASSEMBLE
static void examine_super1(struct supertype *st, char *homehost)
{
        struct mdp_superblock_1 *sb = st->sb;
        time_t atime;
        unsigned int d;
        int role;
        int delta_extra = 0;
        int i;
        char *c;
        int l = homehost ? strlen(homehost) : 0;
        int layout;
        unsigned long long sb_offset;
        struct mdinfo info;

        printf("          Magic : %08x\n", __le32_to_cpu(sb->magic));
        printf("        Version : 1");
        sb_offset = __le64_to_cpu(sb->super_offset);
        if (sb_offset <= 4)
                printf(".1\n");
        else if (sb_offset <= 8)
                printf(".2\n");
        else
                printf(".0\n");
        printf("    Feature Map : 0x%x\n", __le32_to_cpu(sb->feature_map));
        printf("     Array UUID : ");
        for (i=0; i<16; i++) {
                if ((i&3)==0 && i != 0) printf(":");
                printf("%02x", sb->set_uuid[i]);
        }
        printf("\n");
        printf("           Name : %.32s", sb->set_name);
        if (l > 0 && l < 32 &&
            sb->set_name[l] == ':' &&
            strncmp(sb->set_name, homehost, l) == 0)
                printf("  (local to host %s)", homehost);
        printf("\n");
        atime = __le64_to_cpu(sb->ctime) & 0xFFFFFFFFFFULL;
        printf("  Creation Time : %.24s\n", ctime(&atime));
        c=map_num(pers, __le32_to_cpu(sb->level));
        printf("     Raid Level : %s\n", c?c:"-unknown-");
        printf("   Raid Devices : %d\n", __le32_to_cpu(sb->raid_disks));
        printf("\n");
        printf(" Avail Dev Size : %llu%s\n",
               (unsigned long long)__le64_to_cpu(sb->data_size),
               human_size(__le64_to_cpu(sb->data_size)<<9));
        if (__le32_to_cpu(sb->level) > 0) {
                int ddsks = 0, ddsks_denom = 1;
                switch(__le32_to_cpu(sb->level)) {
                case 1: ddsks=1;break;
                case 4:
                case 5: ddsks = __le32_to_cpu(sb->raid_disks)-1; break;
                case 6: ddsks = __le32_to_cpu(sb->raid_disks)-2; break;
                case 10:
                        layout = __le32_to_cpu(sb->layout);
                        ddsks = __le32_to_cpu(sb->raid_disks);
                        ddsks_denom = (layout&255) * ((layout>>8)&255);
                }
                if (ddsks) {
                        long long asize = __le64_to_cpu(sb->size);
                        asize = (asize << 9) * ddsks / ddsks_denom;
                        printf("     Array Size : %llu%s\n",
                               asize >> 10,  human_size(asize));
                }
                if (sb->size != sb->data_size)
                        printf("  Used Dev Size : %llu%s\n",
                               (unsigned long long)__le64_to_cpu(sb->size),
                               human_size(__le64_to_cpu(sb->size)<<9));
        }
        if (sb->data_offset)
                printf("    Data Offset : %llu sectors\n",
                       (unsigned long long)__le64_to_cpu(sb->data_offset));
        if (sb->new_offset &&
            (__le32_to_cpu(sb->feature_map) & MD_FEATURE_NEW_OFFSET)) {
                unsigned long long offset = __le64_to_cpu(sb->data_offset);
                offset += (signed)(int32_t)__le32_to_cpu(sb->new_offset);
                printf("     New Offset : %llu sectors\n", offset);
        }
        printf("   Super Offset : %llu sectors\n",
               (unsigned long long)__le64_to_cpu(sb->super_offset));
        if (__le32_to_cpu(sb->feature_map) & MD_FEATURE_RECOVERY_OFFSET)
                printf("Recovery Offset : %llu sectors\n", (unsigned long long)__le64_to_cpu(sb->recovery_offset));

        st->ss->getinfo_super(st, &info, NULL);
        if (info.space_after != 1 &&
            !(__le32_to_cpu(sb->feature_map) & MD_FEATURE_NEW_OFFSET))
                printf("   Unused Space : before=%llu sectors, after=%llu sectors\n",
                       info.space_before, info.space_after);

        printf("          State : %s\n", (__le64_to_cpu(sb->resync_offset)+1)? "active":"clean");
        printf("    Device UUID : ");
        for (i=0; i<16; i++) {
                if ((i&3)==0 && i != 0) printf(":");
                printf("%02x", sb->device_uuid[i]);
        }
        printf("\n");
        printf("\n");
        if (sb->feature_map & __cpu_to_le32(MD_FEATURE_BITMAP_OFFSET)) {
                printf("Internal Bitmap : %ld sectors from superblock\n",
                       (long)(int32_t)__le32_to_cpu(sb->bitmap_offset));
        }
        if (sb->feature_map & __cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE)) {
                printf("  Reshape pos'n : %llu%s\n", (unsigned long long)__le64_to_cpu(sb->reshape_position)/2,
                       human_size(__le64_to_cpu(sb->reshape_position)<<9));
                if (__le32_to_cpu(sb->delta_disks)) {
                        printf("  Delta Devices : %d", __le32_to_cpu(sb->delta_disks));
                        printf(" (%d->%d)\n",
                               __le32_to_cpu(sb->raid_disks)-__le32_to_cpu(sb->delta_disks),
                               __le32_to_cpu(sb->raid_disks));
                        if ((int)__le32_to_cpu(sb->delta_disks) < 0)
                                delta_extra = -__le32_to_cpu(sb->delta_disks);
                }
                if (__le32_to_cpu(sb->new_level) != __le32_to_cpu(sb->level)) {
                        c = map_num(pers, __le32_to_cpu(sb->new_level));
                        printf("      New Level : %s\n", c?c:"-unknown-");
                }
                if (__le32_to_cpu(sb->new_layout) != __le32_to_cpu(sb->layout)) {
                        if (__le32_to_cpu(sb->level) == 5) {
                                c = map_num(r5layout, __le32_to_cpu(sb->new_layout));
                                printf("     New Layout : %s\n", c?c:"-unknown-");
                        }
                        if (__le32_to_cpu(sb->level) == 6) {
                                c = map_num(r6layout, __le32_to_cpu(sb->new_layout));
                                printf("     New Layout : %s\n", c?c:"-unknown-");
                        }
                        if (__le32_to_cpu(sb->level) == 10) {
                                printf("     New Layout :");
                                print_r10_layout(__le32_to_cpu(sb->new_layout));
                                printf("\n");
                        }
                }
                if (__le32_to_cpu(sb->new_chunk) != __le32_to_cpu(sb->chunksize))
                        printf("  New Chunksize : %dK\n", __le32_to_cpu(sb->new_chunk)/2);
                printf("\n");
        }
        if (sb->devflags) {
                printf("          Flags :");
                if (sb->devflags & WriteMostly1)
                        printf(" write-mostly");
                printf("\n");
        }

        atime = __le64_to_cpu(sb->utime) & 0xFFFFFFFFFFULL;
        printf("    Update Time : %.24s\n", ctime(&atime));

        if (sb->bblog_size && sb->bblog_offset) {
                printf("  Bad Block Log : %d entries available at offset %ld sectors",
                       __le16_to_cpu(sb->bblog_size)*512/8,
                       (long)(int32_t)__le32_to_cpu(sb->bblog_offset));
                if (sb->feature_map &
                    __cpu_to_le32(MD_FEATURE_BAD_BLOCKS))
                        printf(" - bad blocks present.");
                printf("\n");
        }


        if (calc_sb_1_csum(sb) == sb->sb_csum)
                printf("       Checksum : %x - correct\n", __le32_to_cpu(sb->sb_csum));
        else
                printf("       Checksum : %x - expected %x\n", __le32_to_cpu(sb->sb_csum),
                       __le32_to_cpu(calc_sb_1_csum(sb)));
        printf("         Events : %llu\n", (unsigned long long)__le64_to_cpu(sb->events));
        printf("\n");
        if (__le32_to_cpu(sb->level) == 5) {
                c = map_num(r5layout, __le32_to_cpu(sb->layout));
                printf("         Layout : %s\n", c?c:"-unknown-");
        }
        if (__le32_to_cpu(sb->level) == 6) {
                c = map_num(r6layout, __le32_to_cpu(sb->layout));
                printf("         Layout : %s\n", c?c:"-unknown-");
        }
        if (__le32_to_cpu(sb->level) == 10) {
                int lo = __le32_to_cpu(sb->layout);
                printf("         Layout :");
                print_r10_layout(lo);
                printf("\n");
        }
        switch(__le32_to_cpu(sb->level)) {
        case 0:
        case 4:
        case 5:
        case 6:
        case 10:
                printf("     Chunk Size : %dK\n", __le32_to_cpu(sb->chunksize)/2);
                break;
        case -1:
                printf("       Rounding : %dK\n", __le32_to_cpu(sb->chunksize)/2);
                break;
        default: break;
        }
        printf("\n");
#if 0
        /* This turns out to just be confusing */
        printf("    Array Slot : %d (", __le32_to_cpu(sb->dev_number));
        for (i= __le32_to_cpu(sb->max_dev); i> 0 ; i--)
                if (__le16_to_cpu(sb->dev_roles[i-1]) != 0xffff)
                        break;
        for (d=0; d < i; d++) {
                int role = __le16_to_cpu(sb->dev_roles[d]);
                if (d) printf(", ");
                if (role == 0xffff) printf("empty");
                else if(role == 0xfffe) printf("failed");
                else printf("%d", role);
        }
        printf(")\n");
#endif
        printf("   Device Role : ");
        d = __le32_to_cpu(sb->dev_number);
        if (d < __le32_to_cpu(sb->max_dev))
                role = __le16_to_cpu(sb->dev_roles[d]);
        else
                role = 0xFFFF;
        if (role >= 0xFFFE)
                printf("spare\n");
        else if (sb->feature_map & __cpu_to_le32(MD_FEATURE_REPLACEMENT))
                printf("Replacement device %d\n", role);
        else
                printf("Active device %d\n", role);

        printf("   Array State : ");
        for (d=0; d<__le32_to_cpu(sb->raid_disks) + delta_extra; d++) {
                int cnt = 0;
                unsigned int i;
                for (i=0; i< __le32_to_cpu(sb->max_dev); i++) {
                        unsigned int role = __le16_to_cpu(sb->dev_roles[i]);
                        if (role == d)
                                cnt++;
                }
                if (cnt == 2)
                        printf("R");
                else if (cnt == 1)
                        printf("A");
                else if (cnt == 0)
                        printf(".");
                else
                        printf("?");
        }
#if 0
        /* This is confusing too */
        faulty = 0;
        for (i=0; i< __le32_to_cpu(sb->max_dev); i++) {
                int role = __le16_to_cpu(sb->dev_roles[i]);
                if (role == 0xFFFE)
                        faulty++;
        }
        if (faulty) printf(" %d failed", faulty);
#endif
        printf(" ('A' == active, '.' == missing, 'R' == replacing)");
        printf("\n");
}


static void brief_examine_super1(struct supertype *st, int verbose)
{
        struct mdp_superblock_1 *sb = st->sb;
        int i;
        unsigned long long sb_offset;
        char *nm;
        char *c=map_num(pers, __le32_to_cpu(sb->level));

        nm = strchr(sb->set_name, ':');
        if (nm)
                nm++;
        else if (sb->set_name[0])
                nm = sb->set_name;
        else
                nm = NULL;

        printf("ARRAY ");
        if (nm) {
                printf("/dev/md/");
                print_escape(nm);
                putchar(' ');
        }
        if (verbose && c)
                printf(" level=%s", c);
        sb_offset = __le64_to_cpu(sb->super_offset);
        if (sb_offset <= 4)
                printf(" metadata=1.1 ");
        else if (sb_offset <= 8)
                printf(" metadata=1.2 ");
        else
                printf(" metadata=1.0 ");
        if (verbose)
                printf("num-devices=%d ", __le32_to_cpu(sb->raid_disks));
        printf("UUID=");
        for (i=0; i<16; i++) {
                if ((i&3)==0 && i != 0) printf(":");
                printf("%02x", sb->set_uuid[i]);
        }
        if (sb->set_name[0]) {
                printf(" name=");
                print_quoted(sb->set_name);
        }
        printf("\n");
}

static void export_examine_super1(struct supertype *st)
{
        struct mdp_superblock_1 *sb = st->sb;
        int i;
        int len = 32;
        int layout;

        printf("MD_LEVEL=%s\n", map_num(pers, __le32_to_cpu(sb->level)));
        printf("MD_DEVICES=%d\n", __le32_to_cpu(sb->raid_disks));
        for (i=0; i<32; i++)
                if (sb->set_name[i] == '\n' ||
                    sb->set_name[i] == '\0') {
                        len = i;
                        break;
                }
        if (len)
                printf("MD_NAME=%.*s\n", len, sb->set_name);
        if (__le32_to_cpu(sb->level) > 0) {
                int ddsks = 0, ddsks_denom = 1;
                switch(__le32_to_cpu(sb->level)) {
                        case 1: ddsks=1;break;
                        case 4:
                        case 5: ddsks = __le32_to_cpu(sb->raid_disks)-1; break;
                        case 6: ddsks = __le32_to_cpu(sb->raid_disks)-2; break;
                        case 10:
                                layout = __le32_to_cpu(sb->layout);
                                ddsks = __le32_to_cpu(sb->raid_disks);
                                ddsks_denom = (layout&255) * ((layout>>8)&255);
                        }
                if (ddsks) {
                        long long asize = __le64_to_cpu(sb->size);
                        asize = (asize << 9) * ddsks / ddsks_denom;
                        printf("MD_ARRAY_SIZE=%s\n",human_size_brief(asize,JEDEC));
                }
        }
        printf("MD_UUID=");
        for (i=0; i<16; i++) {
                if ((i&3)==0 && i != 0) printf(":");
                printf("%02x", sb->set_uuid[i]);
        }
        printf("\n");
        printf("MD_UPDATE_TIME=%llu\n",
               __le64_to_cpu(sb->utime) & 0xFFFFFFFFFFULL);
        printf("MD_DEV_UUID=");
        for (i=0; i<16; i++) {
                if ((i&3)==0 && i != 0) printf(":");
                printf("%02x", sb->device_uuid[i]);
        }
        printf("\n");
        printf("MD_EVENTS=%llu\n",
               (unsigned long long)__le64_to_cpu(sb->events));
}

static int copy_metadata1(struct supertype *st, int from, int to)
{
        /* Read superblock.  If it looks good, write it out.
         * Then if a bitmap is present, copy that.
         * And if a bad-block-list is present, copy that too.
         */
        void *buf;
        unsigned long long dsize, sb_offset;
        const int bufsize = 4*1024;
        struct mdp_superblock_1 super, *sb;

        if (posix_memalign(&buf, 4096, bufsize) != 0)
                return 1;

        if (!get_dev_size(from, NULL, &dsize))
                goto err;

        dsize >>= 9;
        if (dsize < 24)
                goto err;
        switch(st->minor_version) {
        case 0:
                sb_offset = dsize;
                sb_offset -= 8*2;
                sb_offset &= ~(4*2-1);
                break;
        case 1:
                sb_offset = 0;
                break;
        case 2:
                sb_offset = 4*2;
                break;
        default:
                goto err;
        }

        if (lseek64(from, sb_offset << 9, 0) < 0LL)
                goto err;
        if (read(from, buf, bufsize) != bufsize)
                goto err;

        sb = buf;
        super = *sb; // save most of sb for when we reuse buf

        if (__le32_to_cpu(super.magic) != MD_SB_MAGIC ||
            __le32_to_cpu(super.major_version) != 1 ||
            __le64_to_cpu(super.super_offset) != sb_offset ||
            calc_sb_1_csum(sb) != super.sb_csum)
                goto err;

        if (lseek64(to, sb_offset << 9, 0) < 0LL)
                goto err;
        if (write(to, buf, bufsize) != bufsize)
                goto err;

        if (super.feature_map & __le32_to_cpu(MD_FEATURE_BITMAP_OFFSET)) {
                unsigned long long bitmap_offset = sb_offset;
                int bytes = 4096; // just an estimate.
                int written = 0;
                struct align_fd afrom, ato;

                init_afd(&afrom, from);
                init_afd(&ato, to);

                bitmap_offset += (int32_t)__le32_to_cpu(super.bitmap_offset);

                if (lseek64(from, bitmap_offset<<9, 0) < 0)
                        goto err;
                if (lseek64(to, bitmap_offset<<9, 0) < 0)
                        goto err;

                for (written = 0; written < bytes ; ) {
                        int n = bytes - written;
                        if (n > 4096)
                                n = 4096;
                        if (aread(&afrom, buf, n) != n)
                                goto err;
                        if (written == 0) {
                                /* have the header, can calculate
                                 * correct bitmap bytes */
                                bitmap_super_t *bms;
                                int bits;
                                bms = (void*)buf;
                                bits = __le64_to_cpu(bms->sync_size) / (__le32_to_cpu(bms->chunksize)>>9);
                                bytes = (bits+7) >> 3;
                                bytes += sizeof(bitmap_super_t);
                                bytes = ROUND_UP(bytes, 512);
                                if (n > bytes)
                                        n =  bytes;
                        }
                        if (awrite(&ato, buf, n) != n)
                                goto err;
                        written += n;
                }
        }

        if (super.bblog_size != 0 &&
            __le32_to_cpu(super.bblog_size) <= 100 &&
            super.bblog_offset != 0 &&
            (super.feature_map & __le32_to_cpu(MD_FEATURE_BAD_BLOCKS))) {
                /* There is a bad block log */
                unsigned long long bb_offset = sb_offset;
                int bytes = __le32_to_cpu(super.bblog_size) * 512;
                int written = 0;
                struct align_fd afrom, ato;

                init_afd(&afrom, from);
                init_afd(&ato, to);

                bb_offset += (int32_t)__le32_to_cpu(super.bblog_offset);

                if (lseek64(from, bb_offset<<9, 0) < 0)
                        goto err;
                if (lseek64(to, bb_offset<<9, 0) < 0)
                        goto err;

                for (written = 0; written < bytes ; ) {
                        int n = bytes - written;
                        if (n > 4096)
                                n = 4096;
                        if (aread(&afrom, buf, n) != n)
                                goto err;

                        if (awrite(&ato, buf, n) != n)
                                goto err;
                        written += n;
                }
        }

        free(buf);
        return 0;

err:
        free(buf);
        return 1;
}

static void detail_super1(struct supertype *st, char *homehost)
{
        struct mdp_superblock_1 *sb = st->sb;
        int i;
        int l = homehost ? strlen(homehost) : 0;

        printf("           Name : %.32s", sb->set_name);
        if (l > 0 && l < 32 &&
            sb->set_name[l] == ':' &&
            strncmp(sb->set_name, homehost, l) == 0)
                printf("  (local to host %s)", homehost);
        printf("\n           UUID : ");
        for (i=0; i<16; i++) {
                if ((i&3)==0 && i != 0) printf(":");
                printf("%02x", sb->set_uuid[i]);
        }
        printf("\n         Events : %llu\n\n", (unsigned long long)__le64_to_cpu(sb->events));
}

static void brief_detail_super1(struct supertype *st)
{
        struct mdp_superblock_1 *sb = st->sb;
        int i;

        if (sb->set_name[0]) {
                printf(" name=");
                print_quoted(sb->set_name);
        }
        printf(" UUID=");
        for (i=0; i<16; i++) {
                if ((i&3)==0 && i != 0) printf(":");
                printf("%02x", sb->set_uuid[i]);
        }
}

static void export_detail_super1(struct supertype *st)
{
        struct mdp_superblock_1 *sb = st->sb;
        int i;
        int len = 32;

        for (i=0; i<32; i++)
                if (sb->set_name[i] == '\n' ||
                    sb->set_name[i] == '\0') {
                        len = i;
                        break;
                }
        if (len)
                printf("MD_NAME=%.*s\n", len, sb->set_name);
}

static int examine_badblocks_super1(struct supertype *st, int fd, char *devname)
{
        struct mdp_superblock_1 *sb = st->sb;
        unsigned long long offset;
        int size;
        __u64 *bbl, *bbp;
        int i;

        if  (!sb->bblog_size || __le32_to_cpu(sb->bblog_size) > 100
             || !sb->bblog_offset){
                printf("No bad-blocks list configured on %s\n", devname);
                return 0;
        }
        if ((sb->feature_map & __cpu_to_le32(MD_FEATURE_BAD_BLOCKS))
            == 0) {
                printf("Bad-blocks list is empty in %s\n", devname);
                return 0;
        }

        size = __le32_to_cpu(sb->bblog_size)* 512;
        if (posix_memalign((void**)&bbl, 4096, size) != 0) {
                pr_err("%s could not allocate badblocks list\n", __func__);
                return 0;
        }
        offset = __le64_to_cpu(sb->super_offset) +
                (int)__le32_to_cpu(sb->bblog_offset);
        offset <<= 9;
        if (lseek64(fd, offset, 0) < 0) {
                pr_err("Cannot seek to bad-blocks list\n");
                return 1;
        }
        if (read(fd, bbl, size) != size) {
                pr_err("Cannot read bad-blocks list\n");
                return 1;
        }
        /* 64bits per entry. 10 bits is block-count, 54 bits is block
         * offset.  Blocks are sectors unless bblog->shift makes them bigger
         */
        bbp = (__u64*)bbl;
        printf("Bad-blocks on %s:\n", devname);
        for (i = 0; i < size/8; i++, bbp++) {
                __u64 bb = __le64_to_cpu(*bbp);
                int count = bb & 0x3ff;
                unsigned long long sector = bb >> 10;

                if (bb + 1 == 0)
                        break;

                sector <<= sb->bblog_shift;
                count <<= sb->bblog_shift;

                printf("%20llu for %d sectors\n", sector, count);
        }
        return 0;
}

#endif

static int match_home1(struct supertype *st, char *homehost)
{
        struct mdp_superblock_1 *sb = st->sb;
        int l = homehost ? strlen(homehost) : 0;

        return (l > 0 && l < 32 &&
                sb->set_name[l] == ':' &&
                strncmp(sb->set_name, homehost, l) == 0);
}

static void uuid_from_super1(struct supertype *st, int uuid[4])
{
        struct mdp_superblock_1 *super = st->sb;
        char *cuuid = (char*)uuid;
        int i;
        for (i=0; i<16; i++)
                cuuid[i] = super->set_uuid[i];
}

static void getinfo_super1(struct supertype *st, struct mdinfo *info, char *map)
{
        struct mdp_superblock_1 *sb = st->sb;
        struct bitmap_super_s *bsb = (void*)(((char*)sb)+MAX_SB_SIZE);
        struct misc_dev_info *misc = (void*)(((char*)sb)+MAX_SB_SIZE+BM_SUPER_SIZE);
        int working = 0;
        unsigned int i;
        unsigned int role;
        unsigned int map_disks = info->array.raid_disks;
        unsigned long long super_offset;
        unsigned long long data_size;

        memset(info, 0, sizeof(*info));
        info->array.major_version = 1;
        info->array.minor_version = st->minor_version;
        info->array.patch_version = 0;
        info->array.raid_disks = __le32_to_cpu(sb->raid_disks);
        info->array.level = __le32_to_cpu(sb->level);
        info->array.layout = __le32_to_cpu(sb->layout);
        info->array.md_minor = -1;
        info->array.ctime = __le64_to_cpu(sb->ctime);
        info->array.utime = __le64_to_cpu(sb->utime);
        info->array.chunk_size = __le32_to_cpu(sb->chunksize)*512;
        info->array.state =
                (__le64_to_cpu(sb->resync_offset) == MaxSector)
                ? 1 : 0;

        info->data_offset = __le64_to_cpu(sb->data_offset);
        info->component_size = __le64_to_cpu(sb->size);
        if (sb->feature_map & __le32_to_cpu(MD_FEATURE_BITMAP_OFFSET))
                info->bitmap_offset = (int32_t)__le32_to_cpu(sb->bitmap_offset);

        info->disk.major = 0;
        info->disk.minor = 0;
        info->disk.number = __le32_to_cpu(sb->dev_number);
        if (__le32_to_cpu(sb->dev_number) >= __le32_to_cpu(sb->max_dev) ||
            __le32_to_cpu(sb->dev_number) >= MAX_DEVS)
                role = 0xfffe;
        else
                role = __le16_to_cpu(sb->dev_roles[__le32_to_cpu(sb->dev_number)]);

        super_offset = __le64_to_cpu(sb->super_offset);
        data_size = __le64_to_cpu(sb->size);
        if (info->data_offset < super_offset) {
                unsigned long long end;
                info->space_before = info->data_offset;
                end = super_offset;

                if (sb->bblog_offset && sb->bblog_size) {
                        unsigned long long bboffset = super_offset;
                        bboffset += (int32_t)__le32_to_cpu(sb->bblog_offset);
                        if (bboffset < end)
                                end = bboffset;
                }

                if (super_offset + info->bitmap_offset < end)
                        end = super_offset + info->bitmap_offset;

                if (info->data_offset + data_size < end)
                        info->space_after = end - data_size - info->data_offset;
                else
                        info->space_after = 0;
        } else {
                unsigned long long earliest;
                earliest = super_offset + (32+4)*2; /* match kernel */
                if (info->bitmap_offset > 0) {
                        unsigned long long bmend = info->bitmap_offset;
                        unsigned long long size = __le64_to_cpu(bsb->sync_size);
                        size /= __le32_to_cpu(bsb->chunksize) >> 9;
                        size = (size + 7) >> 3;
                        size += sizeof(bitmap_super_t);
                        size = ROUND_UP(size, 4096);
                        size /= 512;
                        bmend += size;
                        if (bmend > earliest)
                                bmend = earliest;
                }
                if (sb->bblog_offset && sb->bblog_size) {
                        unsigned long long bbend = super_offset;
                        bbend += (int32_t)__le32_to_cpu(sb->bblog_offset);
                        bbend += __le32_to_cpu(sb->bblog_size);
                        if (bbend > earliest)
                                earliest = bbend;
                }
                if (earliest < info->data_offset)
                        info->space_before = info->data_offset - earliest;
                else
                        info->space_before = 0;
                info->space_after = misc->device_size - data_size - info->data_offset;
        }
        if (info->space_before == 0 && info->space_after == 0) {
                /* It will look like we don't support data_offset changes,
                 * be we do - it's just that there is no room.
                 * A change that reduced the number of devices should
                 * still be allowed, so set the otherwise useless value of '1'
                 */
                info->space_after = 1;
        }

        info->disk.raid_disk = -1;
        switch(role) {
        case 0xFFFF:
                info->disk.state = 0; /* spare: not active, not sync, not faulty */
                break;
        case 0xFFFE:
                info->disk.state = 1; /* faulty */
                break;
        default:
                info->disk.state = 6; /* active and in sync */
                info->disk.raid_disk = role;
        }
        if (sb->devflags & WriteMostly1)
                info->disk.state |= (1 << MD_DISK_WRITEMOSTLY);
        info->events = __le64_to_cpu(sb->events);
        sprintf(info->text_version, "1.%d", st->minor_version);
        info->safe_mode_delay = 200;

        memcpy(info->uuid, sb->set_uuid, 16);

        strncpy(info->name, sb->set_name, 32);
        info->name[32] = 0;

        if ((__le32_to_cpu(sb->feature_map)&MD_FEATURE_REPLACEMENT)) {
                info->disk.state &= ~(1 << MD_DISK_SYNC);
                info->disk.state |=  1 << MD_DISK_REPLACEMENT;
        }


        if (sb->feature_map & __le32_to_cpu(MD_FEATURE_RECOVERY_OFFSET))
                info->recovery_start = __le32_to_cpu(sb->recovery_offset);
        else
                info->recovery_start = MaxSector;

        if (sb->feature_map & __le32_to_cpu(MD_FEATURE_RESHAPE_ACTIVE)) {
                info->reshape_active = 1;
                if (info->array.level == 10)
                        info->reshape_active |= RESHAPE_NO_BACKUP;
                info->reshape_progress = __le64_to_cpu(sb->reshape_position);
                info->new_level = __le32_to_cpu(sb->new_level);
                info->delta_disks = __le32_to_cpu(sb->delta_disks);
                info->new_layout = __le32_to_cpu(sb->new_layout);
                info->new_chunk = __le32_to_cpu(sb->new_chunk)<<9;
                if (info->delta_disks < 0)
                        info->array.raid_disks -= info->delta_disks;
        } else
                info->reshape_active = 0;

        info->recovery_blocked = info->reshape_active;

        if (map)
                for (i=0; i<map_disks; i++)
                        map[i] = 0;
        for (i = 0; i < __le32_to_cpu(sb->max_dev); i++) {
                role = __le16_to_cpu(sb->dev_roles[i]);
                if (/*role == 0xFFFF || */role < (unsigned) info->array.raid_disks) {
                        working++;
                        if (map && role < map_disks)
                                map[role] = 1;
                }
        }

        info->array.working_disks = working;
}

static struct mdinfo *container_content1(struct supertype *st, char *subarray)
{
        struct mdinfo *info;

        if (subarray)
                return NULL;

        info = xmalloc(sizeof(*info));
        getinfo_super1(st, info, NULL);
        return info;
}

static int update_super1(struct supertype *st, struct mdinfo *info,
                         char *update,
                         char *devname, int verbose,
                         int uuid_set, char *homehost)
{
        /* NOTE: for 'assemble' and 'force' we need to return non-zero
         * if any change was made.  For others, the return value is
         * ignored.
         */
        int rv = 0;
        struct mdp_superblock_1 *sb = st->sb;

        if (strcmp(update, "homehost") == 0 &&
            homehost) {
                /* Note that 'homehost' is special as it is really
                 * a "name" update.
                 */
                char *c;
                update = "name";
                c = strchr(sb->set_name, ':');
                if (c)
                        strncpy(info->name, c+1, 31 - (c-sb->set_name));
                else
                        strncpy(info->name, sb->set_name, 32);
                info->name[32] = 0;
        }

        if (strcmp(update, "force-one")==0) {
                /* Not enough devices for a working array,
                 * so bring this one up-to-date
                 */
                if (sb->events != __cpu_to_le64(info->events))
                        rv = 1;
                sb->events = __cpu_to_le64(info->events);
        } else if (strcmp(update, "force-array")==0) {
                /* Degraded array and 'force' requests to
                 * maybe need to mark it 'clean'.
                 */
                switch(__le32_to_cpu(sb->level)) {
                case 5: case 4: case 6:
                        /* need to force clean */
                        if (sb->resync_offset != MaxSector)
                                rv = 1;
                        sb->resync_offset = MaxSector;
                }
        } else if (strcmp(update, "assemble")==0) {
                int d = info->disk.number;
                int want;
                if (info->disk.state & (1<<MD_DISK_ACTIVE))
                        want = info->disk.raid_disk;
                else
                        want = 0xFFFF;
                if (sb->dev_roles[d] != __cpu_to_le16(want)) {
                        sb->dev_roles[d] = __cpu_to_le16(want);
                        rv = 1;
                }
                if (info->reshape_active &&
                    sb->feature_map & __le32_to_cpu(MD_FEATURE_RESHAPE_ACTIVE) &&
                    info->delta_disks >= 0 &&
                    info->reshape_progress < __le64_to_cpu(sb->reshape_position)) {
                        sb->reshape_position = __cpu_to_le64(info->reshape_progress);
                        rv = 1;
                }
                if (info->reshape_active &&
                    sb->feature_map & __le32_to_cpu(MD_FEATURE_RESHAPE_ACTIVE) &&
                    info->delta_disks < 0 &&
                    info->reshape_progress > __le64_to_cpu(sb->reshape_position)) {
                        sb->reshape_position = __cpu_to_le64(info->reshape_progress);
                        rv = 1;
                }
        } else if (strcmp(update, "linear-grow-new") == 0) {
                unsigned int i;
                int rfd, fd;
                unsigned int max = __le32_to_cpu(sb->max_dev);

                for (i=0 ; i < max ; i++)
                        if (__le16_to_cpu(sb->dev_roles[i]) >= 0xfffe)
                                break;
                sb->dev_number = __cpu_to_le32(i);
                info->disk.number = i;
                if (max >= __le32_to_cpu(sb->max_dev))
                        sb->max_dev = __cpu_to_le32(max+1);

                if ((rfd = open("/dev/urandom", O_RDONLY)) < 0 ||
                    read(rfd, sb->device_uuid, 16) != 16) {
                        __u32 r[4] = {random(), random(), random(), random()};
                        memcpy(sb->device_uuid, r, 16);
                }
                if (rfd >= 0)
                        close(rfd);

                sb->dev_roles[i] =
                        __cpu_to_le16(info->disk.raid_disk);

                fd = open(devname, O_RDONLY);
                if (fd >= 0) {
                        unsigned long long ds;
                        get_dev_size(fd, devname, &ds);
                        close(fd);
                        ds >>= 9;
                        if (__le64_to_cpu(sb->super_offset) <
                            __le64_to_cpu(sb->data_offset)) {
                                sb->data_size = __cpu_to_le64(
                                        ds - __le64_to_cpu(sb->data_offset));
                        } else {
                                ds -= 8*2;
                                ds &= ~(unsigned long long)(4*2-1);
                                sb->super_offset = __cpu_to_le64(ds);
                                sb->data_size = __cpu_to_le64(
                                        ds - __le64_to_cpu(sb->data_offset));
                        }
                }
        } else if (strcmp(update, "linear-grow-update") == 0) {
                sb->raid_disks = __cpu_to_le32(info->array.raid_disks);
                sb->dev_roles[info->disk.number] =
                        __cpu_to_le16(info->disk.raid_disk);
        } else if (strcmp(update, "resync") == 0) {
                /* make sure resync happens */
                sb->resync_offset = 0ULL;
        } else if (strcmp(update, "uuid") == 0) {
                copy_uuid(sb->set_uuid, info->uuid, super1.swapuuid);

                if (__le32_to_cpu(sb->feature_map)&MD_FEATURE_BITMAP_OFFSET) {
                        struct bitmap_super_s *bm;
                        bm = (struct bitmap_super_s*)(st->sb+MAX_SB_SIZE);
                        memcpy(bm->uuid, sb->set_uuid, 16);
                }
        } else if (strcmp(update, "no-bitmap") == 0) {
                sb->feature_map &= ~__cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
        } else if (strcmp(update, "bbl") == 0) {
                /* only possible if there is room after the bitmap, or if
                 * there is no bitmap
                 */
                unsigned long long sb_offset = __le64_to_cpu(sb->super_offset);
                unsigned long long data_offset = __le64_to_cpu(sb->data_offset);
                long bitmap_offset = (long)(int32_t)__le32_to_cpu(sb->bitmap_offset);
                long bm_sectors = 0;
                long space;

#ifndef MDASSEMBLE
                if (sb->feature_map & __cpu_to_le32(MD_FEATURE_BITMAP_OFFSET)) {
                        struct bitmap_super_s *bsb;
                        bsb = (struct bitmap_super_s *)(((char*)sb)+MAX_SB_SIZE);
                        bm_sectors = bitmap_sectors(bsb);
                }
#endif
                if (sb_offset < data_offset) {
                        /* 1.1 or 1.2.  Put bbl after bitmap leaving at least 32K
                         */
                        long bb_offset;
                        bb_offset = sb_offset + 8;
                        if (bm_sectors && bitmap_offset > 0)
                                bb_offset = bitmap_offset + bm_sectors;
                        while (bb_offset < (long)sb_offset + 8 + 32*2
                               && bb_offset + 8+8 <= (long)data_offset)
                                /* too close to bitmap, and room to grow */
                                bb_offset += 8;
                        if (bb_offset + 8 <= (long)data_offset) {
                                sb->bblog_size = __cpu_to_le16(8);
                                sb->bblog_offset = __cpu_to_le32(bb_offset);
                        }
                } else {
                        /* 1.0 - Put bbl just before super block */
                        if (bm_sectors && bitmap_offset < 0)
                                space = -bitmap_offset - bm_sectors;
                        else
                                space = sb_offset - data_offset -
                                        __le64_to_cpu(sb->data_size);
                        if (space >= 8) {
                                sb->bblog_size = __cpu_to_le16(8);
                                sb->bblog_offset = __cpu_to_le32((unsigned)-8);
                        }
                }
        } else if (strcmp(update, "no-bbl") == 0) {
                if (sb->feature_map & __cpu_to_le32(MD_FEATURE_BAD_BLOCKS))
                        pr_err("Cannot remove active bbl from %s\n",devname);
                else {
                        sb->bblog_size = 0;
                        sb->bblog_shift = 0;
                        sb->bblog_offset = 0;
                }
        } else if (strcmp(update, "name") == 0) {
                if (info->name[0] == 0)
                        sprintf(info->name, "%d", info->array.md_minor);
                memset(sb->set_name, 0, sizeof(sb->set_name));
                if (homehost &&
                    strchr(info->name, ':') == NULL &&
                    strlen(homehost)+1+strlen(info->name) < 32) {
                        strcpy(sb->set_name, homehost);
                        strcat(sb->set_name, ":");
                        strcat(sb->set_name, info->name);
                } else
                        strcpy(sb->set_name, info->name);
        } else if (strcmp(update, "devicesize") == 0 &&
            __le64_to_cpu(sb->super_offset) <
            __le64_to_cpu(sb->data_offset)) {
                /* set data_size to device size less data_offset */
                struct misc_dev_info *misc = (struct misc_dev_info*)
                        (st->sb + MAX_SB_SIZE + BM_SUPER_SIZE);
                printf("Size was %llu\n", (unsigned long long)
                       __le64_to_cpu(sb->data_size));
                sb->data_size = __cpu_to_le64(
                        misc->device_size - __le64_to_cpu(sb->data_offset));
                printf("Size is %llu\n", (unsigned long long)
                       __le64_to_cpu(sb->data_size));
        } else if (strcmp(update, "revert-reshape") == 0) {
                rv = -2;
                if (!(sb->feature_map & __cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE)))
                        pr_err("No active reshape to revert on %s\n",
                               devname);
                else {
                        rv = 0;
                        __u32 temp;
                        sb->raid_disks = __cpu_to_le32(__le32_to_cpu(sb->raid_disks) +
                                                       __le32_to_cpu(sb->delta_disks));
                        if (sb->delta_disks == 0)
                                sb->feature_map ^= __cpu_to_le32(MD_FEATURE_RESHAPE_BACKWARDS);
                        else
                                sb->delta_disks = __cpu_to_le32(-__le32_to_cpu(sb->delta_disks));

                        temp = sb->new_layout;
                        sb->new_layout = sb->layout;
                        sb->layout = temp;

                        temp = sb->new_chunk;
                        sb->new_chunk = sb->chunksize;
                        sb->chunksize = temp;

                        if (sb->feature_map & __cpu_to_le32(MD_FEATURE_NEW_OFFSET)) {
                                sb->data_offset = __cpu_to_le64(__le64_to_cpu(sb->data_offset) +
                                                                (long)(int32_t)__le32_to_cpu(sb->new_offset));
                                sb->new_offset = __cpu_to_le32(-(int32_t)__le32_to_cpu(sb->new_offset));
                        }
                }
        } else if (strcmp(update, "_reshape_progress")==0)
                sb->reshape_position = __cpu_to_le64(info->reshape_progress);
        else if (strcmp(update, "writemostly")==0)
                sb->devflags |= WriteMostly1;
        else if (strcmp(update, "readwrite")==0)
                sb->devflags &= ~WriteMostly1;
        else
                rv = -1;

        sb->sb_csum = calc_sb_1_csum(sb);
        return rv;
}

static int init_super1(struct supertype *st, mdu_array_info_t *info,
                       unsigned long long size, char *name, char *homehost,
                       int *uuid, unsigned long long data_offset)
{
        struct mdp_superblock_1 *sb;
        int spares;
        int rfd;
        char defname[10];
        int sbsize;

        if (posix_memalign((void**)&sb, 4096, SUPER1_SIZE) != 0) {
                pr_err("%s could not allocate superblock\n", __func__);
                return 0;
        }
        memset(sb, 0, SUPER1_SIZE);

        st->sb = sb;
        if (info == NULL) {
                /* zeroing superblock */
                return 0;
        }

        spares = info->working_disks - info->active_disks;
        if (info->raid_disks + spares  > MAX_DEVS) {
                pr_err("too many devices requested: %d+%d > %d\n",
                        info->raid_disks , spares, MAX_DEVS);
                return 0;
        }

        sb->magic = __cpu_to_le32(MD_SB_MAGIC);
        sb->major_version = __cpu_to_le32(1);
        sb->feature_map = 0;
        sb->pad0 = 0;

        if (uuid)
                copy_uuid(sb->set_uuid, uuid, super1.swapuuid);
        else {
                if ((rfd = open("/dev/urandom", O_RDONLY)) < 0 ||
                    read(rfd, sb->set_uuid, 16) != 16) {
                        __u32 r[4] = {random(), random(), random(), random()};
                        memcpy(sb->set_uuid, r, 16);
                }
                if (rfd >= 0) close(rfd);
        }

        if (name == NULL || *name == 0) {
                sprintf(defname, "%d", info->md_minor);
                name = defname;
        }
        if (homehost &&
            strchr(name, ':')== NULL &&
            strlen(homehost)+1+strlen(name) < 32) {
                strcpy(sb->set_name, homehost);
                strcat(sb->set_name, ":");
                strcat(sb->set_name, name);
        } else
                strcpy(sb->set_name, name);

        sb->ctime = __cpu_to_le64((unsigned long long)time(0));
        sb->level = __cpu_to_le32(info->level);
        sb->layout = __cpu_to_le32(info->layout);
        sb->size = __cpu_to_le64(size*2ULL);
        sb->chunksize = __cpu_to_le32(info->chunk_size>>9);
        sb->raid_disks = __cpu_to_le32(info->raid_disks);

        sb->data_offset = __cpu_to_le64(data_offset);
        sb->data_size = __cpu_to_le64(0);
        sb->super_offset = __cpu_to_le64(0);
        sb->recovery_offset = __cpu_to_le64(0);

        sb->utime = sb->ctime;
        sb->events = __cpu_to_le64(1);
        if (info->state & (1<<MD_SB_CLEAN))
                sb->resync_offset = MaxSector;
        else
                sb->resync_offset = 0;
        sbsize = sizeof(struct mdp_superblock_1) + 2 * (info->raid_disks + spares);
        sbsize = ROUND_UP(sbsize, 512);
        sb->max_dev = __cpu_to_le32((sbsize - sizeof(struct mdp_superblock_1)) / 2);

        memset(sb->dev_roles, 0xff, MAX_SB_SIZE - sizeof(struct mdp_superblock_1));

        return 1;
}

struct devinfo {
        int fd;
        char *devname;
        long long data_offset;
        mdu_disk_info_t disk;
        struct devinfo *next;
};
#ifndef MDASSEMBLE
/* Add a device to the superblock being created */
static int add_to_super1(struct supertype *st, mdu_disk_info_t *dk,
                         int fd, char *devname, unsigned long long data_offset)
{
        struct mdp_superblock_1 *sb = st->sb;
        __u16 *rp = sb->dev_roles + dk->number;
        struct devinfo *di, **dip;

        if ((dk->state & 6) == 6) /* active, sync */
                *rp = __cpu_to_le16(dk->raid_disk);
        else if ((dk->state & ~2) == 0) /* active or idle -> spare */
                *rp = 0xffff;
        else
                *rp = 0xfffe;

        if (dk->number >= (int)__le32_to_cpu(sb->max_dev) &&
            __le32_to_cpu(sb->max_dev) < MAX_DEVS)
                sb->max_dev = __cpu_to_le32(dk->number+1);

        sb->dev_number = __cpu_to_le32(dk->number);
        sb->devflags = 0; /* don't copy another disks flags */
        sb->sb_csum = calc_sb_1_csum(sb);

        dip = (struct devinfo **)&st->info;
        while (*dip)
                dip = &(*dip)->next;
        di = xmalloc(sizeof(struct devinfo));
        di->fd = fd;
        di->devname = devname;
        di->disk = *dk;
        di->data_offset = data_offset;
        di->next = NULL;
        *dip = di;

        return 0;
}
#endif

static void locate_bitmap1(struct supertype *st, int fd);

static int store_super1(struct supertype *st, int fd)
{
        struct mdp_superblock_1 *sb = st->sb;
        unsigned long long sb_offset;
        struct align_fd afd;
        int sbsize;
        unsigned long long dsize;

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

        dsize >>= 9;

        if (dsize < 24)
                return 2;

        init_afd(&afd, fd);

        /*
         * Calculate the position of the superblock.
         * It is always aligned to a 4K boundary and
         * depending on minor_version, it can be:
         * 0: At least 8K, but less than 12K, from end of device
         * 1: At start of device
         * 2: 4K from start of device.
         */
        switch(st->minor_version) {
        case 0:
                sb_offset = dsize;
                sb_offset -= 8*2;
                sb_offset &= ~(4*2-1);
                break;
        case 1:
                sb_offset = 0;
                break;
        case 2:
                sb_offset = 4*2;
                break;
        default:
                return -EINVAL;
        }



        if (sb_offset != __le64_to_cpu(sb->super_offset) &&
            0 != __le64_to_cpu(sb->super_offset)
                ) {
                pr_err("internal error - sb_offset is wrong\n");
                abort();
        }

        if (lseek64(fd, sb_offset << 9, 0)< 0LL)
                return 3;

        sbsize = ROUND_UP(sizeof(*sb) + 2 * __le32_to_cpu(sb->max_dev), 512);

        if (awrite(&afd, sb, sbsize) != sbsize)
                return 4;

        if (sb->feature_map & __cpu_to_le32(MD_FEATURE_BITMAP_OFFSET)) {
                struct bitmap_super_s *bm = (struct bitmap_super_s*)
                        (((char*)sb)+MAX_SB_SIZE);
                if (__le32_to_cpu(bm->magic) == BITMAP_MAGIC) {
                        locate_bitmap1(st, fd);
                        if (awrite(&afd, bm, sizeof(*bm)) != sizeof(*bm))
                                return 5;
                }
        }
        fsync(fd);
        return 0;
}

static int load_super1(struct supertype *st, int fd, char *devname);

static unsigned long choose_bm_space(unsigned long devsize)
{
        /* if the device is bigger than 8Gig, save 64k for bitmap usage,
         * if bigger than 200Gig, save 128k
         * NOTE: result must be multiple of 4K else bad things happen
         * on 4K-sector devices.
         */
        if (devsize < 64*2) return 0;
        if (devsize - 64*2 >= 200*1024*1024*2)
                return 128*2;
        if (devsize - 4*2 > 8*1024*1024*2)
                return 64*2;
        return 4*2;
}

static void free_super1(struct supertype *st);

#ifndef MDASSEMBLE
static int write_init_super1(struct supertype *st)
{
        struct mdp_superblock_1 *sb = st->sb;
        struct supertype *refst;
        int rfd;
        int rv = 0;
        unsigned long long bm_space;
        unsigned long long reserved;
        struct devinfo *di;
        unsigned long long dsize, array_size;
        unsigned long long sb_offset, headroom;
        unsigned long long data_offset;

        for (di = st->info; di; di = di->next) {
                if (di->disk.state == 1)
                        continue;
                if (di->fd < 0)
                        continue;

                while (Kill(di->devname, NULL, 0, -1, 1) == 0)
                        ;

                sb->dev_number = __cpu_to_le32(di->disk.number);
                if (di->disk.state & (1<<MD_DISK_WRITEMOSTLY))
                        sb->devflags |= WriteMostly1;
                else
                        sb->devflags &= ~WriteMostly1;

                if ((rfd = open("/dev/urandom", O_RDONLY)) < 0 ||
                    read(rfd, sb->device_uuid, 16) != 16) {
                        __u32 r[4] = {random(), random(), random(), random()};
                        memcpy(sb->device_uuid, r, 16);
                }
                if (rfd >= 0)
                        close(rfd);

                sb->events = 0;

                refst = dup_super(st);
                if (load_super1(refst, di->fd, NULL)==0) {
                        struct mdp_superblock_1 *refsb = refst->sb;

                        memcpy(sb->device_uuid, refsb->device_uuid, 16);
                        if (memcmp(sb->set_uuid, refsb->set_uuid, 16)==0) {
                                /* same array, so preserve events and
                                 * dev_number */
                                sb->events = refsb->events;
                                /* bugs in 2.6.17 and earlier mean the
                                 * dev_number chosen in Manage must be preserved
                                 */
                                if (get_linux_version() >= 2006018)
                                        sb->dev_number = refsb->dev_number;
                        }
                        free_super1(refst);
                }
                free(refst);

                if (!get_dev_size(di->fd, NULL, &dsize)) {
                        rv = 1;
                        goto error_out;
                }
                dsize >>= 9;

                if (dsize < 24) {
                        close(di->fd);
                        rv = 2;
                        goto error_out;
                }


                /*
                 * Calculate the position of the superblock.
                 * It is always aligned to a 4K boundary and
                 * depending on minor_version, it can be:
                 * 0: At least 8K, but less than 12K, from end of device
                 * 1: At start of device
                 * 2: 4K from start of device.
                 * Depending on the array size, we might leave extra space
                 * for a bitmap.
                 * Also leave 4K for bad-block log.
                 */
                array_size = __le64_to_cpu(sb->size);
                /* work out how much space we left for a bitmap,
                 * Add 8 sectors for bad block log */
                bm_space = choose_bm_space(array_size) + 8;

                /* We try to leave 0.1% at the start for reshape
                 * operations, but limit this to 128Meg (0.1% of 10Gig)
                 * which is plenty for efficient reshapes
                 * However we make it at least 2 chunks as one chunk
                 * is minimum needed for reshape.
                 */
                headroom = 128 * 1024 * 2;
                while  (headroom << 10 > array_size &&
                        headroom/2 >= __le32_to_cpu(sb->chunksize) * 2)
                        headroom >>= 1;

                data_offset = di->data_offset;
                switch(st->minor_version) {
                case 0:
                        sb_offset = dsize;
                        sb_offset -= 8*2;
                        sb_offset &= ~(4*2-1);
                        sb->super_offset = __cpu_to_le64(sb_offset);
                        if (data_offset == INVALID_SECTORS)
                                sb->data_offset = 0;
                        if (sb_offset < array_size + bm_space)
                                bm_space = sb_offset - array_size;
                        sb->data_size = __cpu_to_le64(sb_offset - bm_space);
                        if (bm_space >= 8) {
                                sb->bblog_size = __cpu_to_le16(8);
                                sb->bblog_offset = __cpu_to_le32((unsigned)-8);
                        }
                        break;
                case 1:
                        sb->super_offset = __cpu_to_le64(0);
                        if (data_offset == INVALID_SECTORS) {
                                reserved = bm_space + 4*2;
                                if (reserved < headroom)
                                        reserved = headroom;
                                if (reserved + array_size > dsize)
                                        reserved = dsize - array_size;
                                /* Try for multiple of 1Meg so it is nicely aligned */
                                #define ONE_MEG (2*1024)
                                if (reserved > ONE_MEG)
                                        reserved = (reserved/ONE_MEG) * ONE_MEG;

                                /* force 4K alignment */
                                reserved &= ~7ULL;

                        } else
                                reserved = data_offset;

                        sb->data_offset = __cpu_to_le64(reserved);
                        sb->data_size = __cpu_to_le64(dsize - reserved);
                        if (reserved >= 8 + 32*2 + 8) {
                                sb->bblog_size = __cpu_to_le16(8);
                                sb->bblog_offset = __cpu_to_le32(8 + 32*2);
                        } else if (reserved >= 16) {
                                sb->bblog_size = __cpu_to_le16(8);
                                sb->bblog_offset = __cpu_to_le32(reserved-8);
                        }
                        break;
                case 2:
                        sb_offset = 4*2;
                        sb->super_offset = __cpu_to_le64(4*2);
                        if (data_offset == INVALID_SECTORS) {
                                if (4*2 + 4*2 + bm_space + array_size
                                    > dsize)
                                        bm_space = dsize - array_size
                                                - 4*2 - 4*2;

                                reserved = bm_space + 4*2 + 4*2;
                                if (reserved < headroom)
                                        reserved = headroom;
                                if (reserved + array_size > dsize)
                                        reserved = dsize - array_size;
                                /* Try for multiple of 1Meg so it is nicely aligned */
                                #define ONE_MEG (2*1024)
                                if (reserved > ONE_MEG)
                                        reserved = (reserved/ONE_MEG) * ONE_MEG;

                                /* force 4K alignment */
                                reserved &= ~7ULL;

                        } else
                                reserved = data_offset;

                        sb->data_offset = __cpu_to_le64(reserved);
                        sb->data_size = __cpu_to_le64(dsize - reserved);
                        if (reserved >= 16 + 32*2 + 8) {
                                sb->bblog_size = __cpu_to_le16(8);
                                sb->bblog_offset = __cpu_to_le32(8 + 32*2);
                        } else if (reserved >= 16+16) {
                                sb->bblog_size = __cpu_to_le16(8);
                                /* '8' sectors for the bblog, and another '8'
                                 * because we want offset from superblock, not
                                 * start of device.
                                 */
                                sb->bblog_offset = __cpu_to_le32(reserved-8-8);
                        }
                        break;
                default:
                        pr_err("Failed to write invalid "
                               "metadata format 1.%i to %s\n",
                               st->minor_version, di->devname);
                        rv = -EINVAL;
                        goto out;
                }

                sb->sb_csum = calc_sb_1_csum(sb);
                rv = store_super1(st, di->fd);
                if (rv == 0 && (__le32_to_cpu(sb->feature_map) & 1))
                        rv = st->ss->write_bitmap(st, di->fd);
                close(di->fd);
                di->fd = -1;
                if (rv)
                        goto error_out;
        }
error_out:
        if (rv)
                pr_err("Failed to write metadata to %s\n",
                       di->devname);
out:
        return rv;
}
#endif

static int compare_super1(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 mdp_superblock_1 *first = st->sb;
        struct mdp_superblock_1 *second = tst->sb;

        if (second->magic != __cpu_to_le32(MD_SB_MAGIC))
                return 1;
        if (second->major_version != __cpu_to_le32(1))
                return 1;

        if (!first) {
                if (posix_memalign((void**)&first, 4096, SUPER1_SIZE) != 0) {
                        pr_err("%s could not allocate superblock\n", __func__);
                        return 1;
                }
                memcpy(first, second, SUPER1_SIZE);
                st->sb = first;
                return 0;
        }
        if (memcmp(first->set_uuid, second->set_uuid, 16)!= 0)
                return 2;

        if (first->ctime      != second->ctime     ||
            first->level      != second->level     ||
            first->layout     != second->layout    ||
            first->size       != second->size      ||
            first->chunksize  != second->chunksize ||
            first->raid_disks != second->raid_disks)
                return 3;
        return 0;
}

static int load_super1(struct supertype *st, int fd, char *devname)
{
        unsigned long long dsize;
        unsigned long long sb_offset;
        struct mdp_superblock_1 *super;
        int uuid[4];
        struct bitmap_super_s *bsb;
        struct misc_dev_info *misc;
        struct align_fd afd;

        free_super1(st);

        init_afd(&afd, fd);

        if (st->ss == NULL || st->minor_version == -1) {
                int bestvers = -1;
                struct supertype tst;
                __u64 bestctime = 0;
                /* guess... choose latest ctime */
                memset(&tst, 0, sizeof(tst));
                tst.ss = &super1;
                for (tst.minor_version = 0; tst.minor_version <= 2 ; tst.minor_version++) {
                        switch(load_super1(&tst, fd, devname)) {
                        case 0: super = tst.sb;
                                if (bestvers == -1 ||
                                    bestctime < __le64_to_cpu(super->ctime)) {
                                        bestvers = tst.minor_version;
                                        bestctime = __le64_to_cpu(super->ctime);
                                }
                                free(super);
                                tst.sb = NULL;
                                break;
                        case 1: return 1; /*bad device */
                        case 2: break; /* bad, try next */
                        }
                }
                if (bestvers != -1) {
                        int rv;
                        tst.minor_version = bestvers;
                        tst.ss = &super1;
                        tst.max_devs = MAX_DEVS;
                        rv = load_super1(&tst, fd, devname);
                        if (rv == 0)
                                *st = tst;
                        return rv;
                }
                return 2;
        }
        if (!get_dev_size(fd, devname, &dsize))
                return 1;
        dsize >>= 9;

        if (dsize < 24) {
                if (devname)
                        pr_err("%s is too small for md: size is %llu sectors.\n",
                                devname, dsize);
                return 1;
        }

        /*
         * Calculate the position of the superblock.
         * It is always aligned to a 4K boundary and
         * depending on minor_version, it can be:
         * 0: At least 8K, but less than 12K, from end of device
         * 1: At start of device
         * 2: 4K from start of device.
         */
        switch(st->minor_version) {
        case 0:
                sb_offset = dsize;
                sb_offset -= 8*2;
                sb_offset &= ~(4*2-1);
                break;
        case 1:
                sb_offset = 0;
                break;
        case 2:
                sb_offset = 4*2;
                break;
        default:
                return -EINVAL;
        }

        if (lseek64(fd, sb_offset << 9, 0)< 0LL) {
                if (devname)
                        pr_err("Cannot seek to superblock on %s: %s\n",
                                devname, strerror(errno));
                return 1;
        }

        if (posix_memalign((void**)&super, 4096, SUPER1_SIZE) != 0) {
                pr_err("%s could not allocate superblock\n",
                        __func__);
                return 1;
        }

        if (aread(&afd, super, MAX_SB_SIZE) != MAX_SB_SIZE) {
                if (devname)
                        pr_err("Cannot read superblock on %s\n",
                                devname);
                free(super);
                return 1;
        }

        if (__le32_to_cpu(super->magic) != MD_SB_MAGIC) {
                if (devname)
                        pr_err("No super block found on %s (Expected magic %08x, got %08x)\n",
                                devname, MD_SB_MAGIC, __le32_to_cpu(super->magic));
                free(super);
                return 2;
        }

        if (__le32_to_cpu(super->major_version) != 1) {
                if (devname)
                        pr_err("Cannot interpret superblock on %s - version is %d\n",
                                devname, __le32_to_cpu(super->major_version));
                free(super);
                return 2;
        }
        if (__le64_to_cpu(super->super_offset) != sb_offset) {
                if (devname)
                        pr_err("No superblock found on %s (super_offset is wrong)\n",
                                devname);
                free(super);
                return 2;
        }
        st->sb = super;

        bsb = (struct bitmap_super_s *)(((char*)super)+MAX_SB_SIZE);

        misc = (struct misc_dev_info*) (((char*)super)+MAX_SB_SIZE+BM_SUPER_SIZE);
        misc->device_size = dsize;

        /* Now check on the bitmap superblock */
        if ((__le32_to_cpu(super->feature_map)&MD_FEATURE_BITMAP_OFFSET) == 0)
                return 0;
        /* Read the bitmap superblock and make sure it looks
         * valid.  If it doesn't clear the bit.  An --assemble --force
         * should get that written out.
         */
        locate_bitmap1(st, fd);
        if (aread(&afd, bsb, 512) != 512)
                goto no_bitmap;

        uuid_from_super1(st, uuid);
        if (__le32_to_cpu(bsb->magic) != BITMAP_MAGIC ||
            memcmp(bsb->uuid, uuid, 16) != 0)
                goto no_bitmap;
        return 0;

 no_bitmap:
        super->feature_map = __cpu_to_le32(__le32_to_cpu(super->feature_map)
                                           & ~MD_FEATURE_BITMAP_OFFSET);
        return 0;
}


static struct supertype *match_metadata_desc1(char *arg)
{
        struct supertype *st = xcalloc(1, sizeof(*st));

        st->container_devnm[0] = 0;
        st->ss = &super1;
        st->max_devs = MAX_DEVS;
        st->sb = NULL;
        /* leading zeros can be safely ignored.  --detail generates them. */
        while (*arg == '0')
                arg++;
        if (strcmp(arg, "1.0") == 0 ||
            strcmp(arg, "1.00") == 0) {
                st->minor_version = 0;
                return st;
        }
        if (strcmp(arg, "1.1") == 0 ||
            strcmp(arg, "1.01") == 0
                ) {
                st->minor_version = 1;
                return st;
        }
        if (strcmp(arg, "1.2") == 0 ||
#ifndef DEFAULT_OLD_METADATA /* ifdef in super0.c */
            strcmp(arg, "default") == 0 ||
#endif /* DEFAULT_OLD_METADATA */
            strcmp(arg, "1.02") == 0) {
                st->minor_version = 2;
                return st;
        }
        if (strcmp(arg, "1") == 0 ||
            strcmp(arg, "default") == 0) {
                st->minor_version = -1;
                return st;
        }

        free(st);
        return NULL;
}

/* find available size on device with this devsize, using
 * superblock type st, and reserving 'reserve' sectors for
 * a possible bitmap
 */
static __u64 _avail_size1(struct supertype *st, __u64 devsize,
                          unsigned long long data_offset, int chunksize)
{
        struct mdp_superblock_1 *super = st->sb;
        int bmspace = 0;
        if (devsize < 24)
                return 0;

        if (super == NULL)
                /* creating:  allow suitable space for bitmap */
                bmspace = choose_bm_space(devsize);
#ifndef MDASSEMBLE
        else if (__le32_to_cpu(super->feature_map)&MD_FEATURE_BITMAP_OFFSET) {
                /* hot-add. allow for actual size of bitmap */
                struct bitmap_super_s *bsb;
                bsb = (struct bitmap_super_s *)(((char*)super)+MAX_SB_SIZE);
                bmspace = bitmap_sectors(bsb);
        }
#endif
        /* Allow space for bad block log */
        if (super && super->bblog_size)
                devsize -= __le16_to_cpu(super->bblog_size);
        else
                devsize -= 8;


        if (st->minor_version < 0)
                /* not specified, so time to set default */
                st->minor_version = 2;

        if (data_offset != INVALID_SECTORS)
                switch(st->minor_version) {
                case 0:
                        return devsize - data_offset - 8*2;
                case 1:
                case 2:
                        return devsize - data_offset;
                default:
                        return 0;
                }

        devsize -= bmspace;

        if (super == NULL && st->minor_version > 0) {
                /* haven't committed to a size yet, so allow some
                 * slack for space for reshape.
                 * Limit slack to 128M, but aim for about 0.1%
                 */
                unsigned long long headroom = 128*1024*2;
                while ((headroom << 10) > devsize &&
                       (chunksize == 0 ||
                        headroom / 2 >= ((unsigned)chunksize*2)*2))
                        headroom >>= 1;
                devsize -= headroom;
        }
        switch(st->minor_version) {
        case 0:
                /* at end */
                return ((devsize - 8*2 ) & ~(4*2-1));
        case 1:
                /* at start, 4K for superblock and possible bitmap */
                return devsize - 4*2;
        case 2:
                /* 4k from start, 4K for superblock and possible bitmap */
                return devsize - (4+4)*2;
        }
        return 0;
}
static __u64 avail_size1(struct supertype *st, __u64 devsize,
                         unsigned long long data_offset)
{
        return _avail_size1(st, devsize, data_offset, 0);
}

static int
add_internal_bitmap1(struct supertype *st,
                     int *chunkp, int delay, int write_behind,
                     unsigned long long size,
                     int may_change, int major)
{
        /*
         * If not may_change, then this is a 'Grow' without sysfs support for
         * bitmaps, and the bitmap must fit after the superblock at 1K offset.
         * If may_change, then this is create or a Grow with sysfs syupport,
         * and we can put the bitmap wherever we like.
         *
         * size is in sectors,  chunk is in bytes !!!
         */

        unsigned long long bits;
        unsigned long long max_bits;
        unsigned long long min_chunk;
        long offset;
        long bbl_offset, bbl_size;
        unsigned long long chunk = *chunkp;
        int room = 0;
        int creating = 0;
        struct mdp_superblock_1 *sb = st->sb;
        bitmap_super_t *bms = (bitmap_super_t*)(((char*)sb) + MAX_SB_SIZE);
        int uuid[4];


        if (__le64_to_cpu(sb->data_size) == 0)
                /* Must be creating the array, else data_size would be non-zero */
                creating = 1;
        switch(st->minor_version) {
        case 0:
                /* either 3K after the superblock (when hot-add),
                 * or some amount of space before.
                 */
                if (creating) {
                        /* We are creating array, so we *know* how much room has
                         * been left.
                         */
                        offset = 0;
                        room = choose_bm_space(__le64_to_cpu(sb->size));
                        bbl_size = 8;
                } else {
                        room = __le64_to_cpu(sb->super_offset)
                                - __le64_to_cpu(sb->data_offset)
                                - __le64_to_cpu(sb->data_size);
                        bbl_size = __le16_to_cpu(sb->bblog_size);
                        if (bbl_size < 8)
                                bbl_size = 8;
                        bbl_offset = (__s32)__le32_to_cpu(sb->bblog_offset);
                        if (bbl_size < -bbl_offset)
                                bbl_size = -bbl_offset;

                        if (!may_change || (room < 3*2 &&
                                  __le32_to_cpu(sb->max_dev) <= 384)) {
                                room = 3*2;
                                offset = 1*2;
                                bbl_size = 0;
                        } else {
                                offset = 0; /* means movable offset */
                        }
                }
                break;
        case 1:
        case 2: /* between superblock and data */
                if (creating) {
                        offset = 4*2;
                        room = choose_bm_space(__le64_to_cpu(sb->size));
                        bbl_size = 8;
                } else {
                        room = __le64_to_cpu(sb->data_offset)
                                - __le64_to_cpu(sb->super_offset);
                        bbl_size = __le16_to_cpu(sb->bblog_size);
                        if (bbl_size)
                                room = __le32_to_cpu(sb->bblog_offset) + bbl_size;
                        else
                                bbl_size = 8;

                        if (!may_change) {
                                room -= 2; /* Leave 1K for superblock */
                                offset = 2;
                                bbl_size = 0;
                        } else {
                                room -= 4*2; /* leave 4K for superblock */
                                offset = 4*2;
                        }
                }
                break;
        default:
                return 0;
        }

        room -= bbl_size;
        if (chunk == UnSet && room > 128*2)
                /* Limit to 128K of bitmap when chunk size not requested */
                room = 128*2;

        max_bits = (room * 512 - sizeof(bitmap_super_t)) * 8;

        min_chunk = 4096; /* sub-page chunks don't work yet.. */
        bits = (size*512)/min_chunk +1;
        while (bits > max_bits) {
                min_chunk *= 2;
                bits = (bits+1)/2;
        }
        if (chunk == UnSet) {
                /* For practical purpose, 64Meg is a good
                 * default chunk size for internal bitmaps.
                 */
                chunk = min_chunk;
                if (chunk < 64*1024*1024)
                        chunk = 64*1024*1024;
        } else if (chunk < min_chunk)
                return 0; /* chunk size too small */
        if (chunk == 0) /* rounding problem */
                return 0;

        if (offset == 0) {
                /* start bitmap on a 4K boundary with enough space for
                 * the bitmap
                 */
                bits = (size*512) / chunk + 1;
                room = ((bits+7)/8 + sizeof(bitmap_super_t) +4095)/4096;
                room *= 8; /* convert 4K blocks to sectors */
                offset = -room - bbl_size;
        }

        sb->bitmap_offset = (int32_t)__cpu_to_le32(offset);

        sb->feature_map = __cpu_to_le32(__le32_to_cpu(sb->feature_map)
                                        | MD_FEATURE_BITMAP_OFFSET);
        memset(bms, 0, sizeof(*bms));
        bms->magic = __cpu_to_le32(BITMAP_MAGIC);
        bms->version = __cpu_to_le32(major);
        uuid_from_super1(st, uuid);
        memcpy(bms->uuid, uuid, 16);
        bms->chunksize = __cpu_to_le32(chunk);
        bms->daemon_sleep = __cpu_to_le32(delay);
        bms->sync_size = __cpu_to_le64(size);
        bms->write_behind = __cpu_to_le32(write_behind);

        *chunkp = chunk;
        return 1;
}

static void locate_bitmap1(struct supertype *st, int fd)
{
        unsigned long long offset;
        struct mdp_superblock_1 *sb;
        int mustfree = 0;

        if (!st->sb) {
                if (st->ss->load_super(st, fd, NULL))
                        return; /* no error I hope... */
                mustfree = 1;
        }
        sb = st->sb;

        offset = __le64_to_cpu(sb->super_offset);
        offset += (int32_t) __le32_to_cpu(sb->bitmap_offset);
        if (mustfree)
                free(sb);
        lseek64(fd, offset<<9, 0);
}

static int write_bitmap1(struct supertype *st, int fd)
{
        struct mdp_superblock_1 *sb = st->sb;
        bitmap_super_t *bms = (bitmap_super_t*)(((char*)sb)+MAX_SB_SIZE);
        int rv = 0;
        void *buf;
        int towrite, n;
        struct align_fd afd;

        init_afd(&afd, fd);

        locate_bitmap1(st, fd);

        if (posix_memalign(&buf, 4096, 4096))
                return -ENOMEM;

        memset(buf, 0xff, 4096);
        memcpy(buf, (char *)bms, sizeof(bitmap_super_t));

        towrite = __le64_to_cpu(bms->sync_size) / (__le32_to_cpu(bms->chunksize)>>9);
        towrite = (towrite+7) >> 3; /* bits to bytes */
        towrite += sizeof(bitmap_super_t);
        towrite = ROUND_UP(towrite, 512);
        while (towrite > 0) {
                n = towrite;
                if (n > 4096)
                        n = 4096;
                n = awrite(&afd, buf, n);
                if (n > 0)
                        towrite -= n;
                else
                        break;
                memset(buf, 0xff, 4096);
        }
        fsync(fd);
        if (towrite)
                rv = -2;

        free(buf);
        return rv;
}

static void free_super1(struct supertype *st)
{
        if (st->sb)
                free(st->sb);
        while (st->info) {
                struct devinfo *di = st->info;
                st->info = di->next;
                if (di->fd >= 0)
                        close(di->fd);
                free(di);
        }
        st->sb = NULL;
}

#ifndef MDASSEMBLE
static int validate_geometry1(struct supertype *st, int level,
                              int layout, int raiddisks,
                              int *chunk, unsigned long long size,
                              unsigned long long data_offset,
                              char *subdev, unsigned long long *freesize,
                              int verbose)
{
        unsigned long long ldsize;
        int fd;

        if (level == LEVEL_CONTAINER) {
                if (verbose)
                        pr_err("1.x metadata does not support containers\n");
                return 0;
        }
        if (chunk && *chunk == UnSet)
                *chunk = DEFAULT_CHUNK;

        if (!subdev)
                return 1;

        fd = open(subdev, O_RDONLY|O_EXCL, 0);
        if (fd < 0) {
                if (verbose)
                        pr_err("super1.x cannot open %s: %s\n",
                                subdev, strerror(errno));
                return 0;
        }

        if (!get_dev_size(fd, subdev, &ldsize)) {
                close(fd);
                return 0;
        }
        close(fd);

        *freesize = _avail_size1(st, ldsize >> 9, data_offset, *chunk);
        return 1;
}
#endif /* MDASSEMBLE */

void *super1_make_v0(struct supertype *st, struct mdinfo *info, mdp_super_t *sb0)
{
        /* Create a v1.0 superblock based on 'info'*/
        void *ret;
        struct mdp_superblock_1 *sb;
        int i;
        int rfd;
        unsigned long long offset;

        if (posix_memalign(&ret, 4096, 1024) != 0)
                return NULL;
        sb = ret;
        memset(ret, 0, 1024);
        sb->magic = __cpu_to_le32(MD_SB_MAGIC);
        sb->major_version = __cpu_to_le32(1);

        copy_uuid(sb->set_uuid, info->uuid, super1.swapuuid);
        sprintf(sb->set_name, "%d", sb0->md_minor);
        sb->ctime = __cpu_to_le32(info->array.ctime+1);
        sb->level = __cpu_to_le32(info->array.level);
        sb->layout = __cpu_to_le32(info->array.layout);
        sb->size = __cpu_to_le64(info->component_size);
        sb->chunksize = __cpu_to_le32(info->array.chunk_size/512);
        sb->raid_disks = __cpu_to_le32(info->array.raid_disks);
        sb->data_size = sb->size;
        sb->resync_offset = MaxSector;
        sb->max_dev = __cpu_to_le32(MD_SB_DISKS);
        sb->dev_number = __cpu_to_le32(info->disk.number);
        sb->utime = __cpu_to_le64(info->array.utime);

        offset = st->devsize/512 - 8*2;
        offset &= ~(4*2-1);
        sb->super_offset = __cpu_to_le64(offset);
        //*(__u64*)(st->other + 128 + 8 + 8) = __cpu_to_le64(offset);

        if ((rfd = open("/dev/urandom", O_RDONLY)) < 0 ||
            read(rfd, sb->device_uuid, 16) != 16) {
                __u32 r[4] = {random(), random(), random(), random()};
                memcpy(sb->device_uuid, r, 16);
        }
        if (rfd >= 0)
                close(rfd);

        for (i = 0; i < MD_SB_DISKS; i++) {
                int state = sb0->disks[i].state;
                sb->dev_roles[i] = 0xFFFF;
                if ((state & (1<<MD_DISK_SYNC)) &&
                    !(state & (1<<MD_DISK_FAULTY)))
                        sb->dev_roles[i] = __cpu_to_le16(sb0->disks[i].raid_disk);
        }
        sb->sb_csum = calc_sb_1_csum(sb);
        return ret;
}

struct superswitch super1 = {
#ifndef MDASSEMBLE
        .examine_super = examine_super1,
        .brief_examine_super = brief_examine_super1,
        .export_examine_super = export_examine_super1,
        .detail_super = detail_super1,
        .brief_detail_super = brief_detail_super1,
        .export_detail_super = export_detail_super1,
        .write_init_super = write_init_super1,
        .validate_geometry = validate_geometry1,
        .add_to_super = add_to_super1,
        .examine_badblocks = examine_badblocks_super1,
        .copy_metadata = copy_metadata1,
#endif
        .match_home = match_home1,
        .uuid_from_super = uuid_from_super1,
        .getinfo_super = getinfo_super1,
        .container_content = container_content1,
        .update_super = update_super1,
        .init_super = init_super1,
        .store_super = store_super1,
        .compare_super = compare_super1,
        .load_super = load_super1,
        .match_metadata_desc = match_metadata_desc1,
        .avail_size = avail_size1,
        .add_internal_bitmap = add_internal_bitmap1,
        .locate_bitmap = locate_bitmap1,
        .write_bitmap = write_bitmap1,
        .free_super = free_super1,
#if __BYTE_ORDER == BIG_ENDIAN
        .swapuuid = 0,
#else
        .swapuuid = 1,
#endif
        .name = "1.x",
};