linux/block/partitions/ldm.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * ldm - Support for Windows Logical Disk Manager (Dynamic Disks)
   4 *
   5 * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
   6 * Copyright (c) 2001-2012 Anton Altaparmakov
   7 * Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
   8 *
   9 * Documentation is available at http://www.linux-ntfs.org/doku.php?id=downloads 
  10 */
  11
  12#include <linux/slab.h>
  13#include <linux/pagemap.h>
  14#include <linux/stringify.h>
  15#include <linux/kernel.h>
  16#include <linux/uuid.h>
  17#include <linux/msdos_partition.h>
  18
  19#include "ldm.h"
  20#include "check.h"
  21
  22/*
  23 * ldm_debug/info/error/crit - Output an error message
  24 * @f:    A printf format string containing the message
  25 * @...:  Variables to substitute into @f
  26 *
  27 * ldm_debug() writes a DEBUG level message to the syslog but only if the
  28 * driver was compiled with debug enabled. Otherwise, the call turns into a NOP.
  29 */
  30#ifndef CONFIG_LDM_DEBUG
  31#define ldm_debug(...)  do {} while (0)
  32#else
  33#define ldm_debug(f, a...) _ldm_printk (KERN_DEBUG, __func__, f, ##a)
  34#endif
  35
  36#define ldm_crit(f, a...)  _ldm_printk (KERN_CRIT,  __func__, f, ##a)
  37#define ldm_error(f, a...) _ldm_printk (KERN_ERR,   __func__, f, ##a)
  38#define ldm_info(f, a...)  _ldm_printk (KERN_INFO,  __func__, f, ##a)
  39
  40static __printf(3, 4)
  41void _ldm_printk(const char *level, const char *function, const char *fmt, ...)
  42{
  43        struct va_format vaf;
  44        va_list args;
  45
  46        va_start (args, fmt);
  47
  48        vaf.fmt = fmt;
  49        vaf.va = &args;
  50
  51        printk("%s%s(): %pV\n", level, function, &vaf);
  52
  53        va_end(args);
  54}
  55
  56/**
  57 * ldm_parse_privhead - Read the LDM Database PRIVHEAD structure
  58 * @data:  Raw database PRIVHEAD structure loaded from the device
  59 * @ph:    In-memory privhead structure in which to return parsed information
  60 *
  61 * This parses the LDM database PRIVHEAD structure supplied in @data and
  62 * sets up the in-memory privhead structure @ph with the obtained information.
  63 *
  64 * Return:  'true'   @ph contains the PRIVHEAD data
  65 *          'false'  @ph contents are undefined
  66 */
  67static bool ldm_parse_privhead(const u8 *data, struct privhead *ph)
  68{
  69        bool is_vista = false;
  70
  71        BUG_ON(!data || !ph);
  72        if (MAGIC_PRIVHEAD != get_unaligned_be64(data)) {
  73                ldm_error("Cannot find PRIVHEAD structure. LDM database is"
  74                        " corrupt. Aborting.");
  75                return false;
  76        }
  77        ph->ver_major = get_unaligned_be16(data + 0x000C);
  78        ph->ver_minor = get_unaligned_be16(data + 0x000E);
  79        ph->logical_disk_start = get_unaligned_be64(data + 0x011B);
  80        ph->logical_disk_size = get_unaligned_be64(data + 0x0123);
  81        ph->config_start = get_unaligned_be64(data + 0x012B);
  82        ph->config_size = get_unaligned_be64(data + 0x0133);
  83        /* Version 2.11 is Win2k/XP and version 2.12 is Vista. */
  84        if (ph->ver_major == 2 && ph->ver_minor == 12)
  85                is_vista = true;
  86        if (!is_vista && (ph->ver_major != 2 || ph->ver_minor != 11)) {
  87                ldm_error("Expected PRIVHEAD version 2.11 or 2.12, got %d.%d."
  88                        " Aborting.", ph->ver_major, ph->ver_minor);
  89                return false;
  90        }
  91        ldm_debug("PRIVHEAD version %d.%d (Windows %s).", ph->ver_major,
  92                        ph->ver_minor, is_vista ? "Vista" : "2000/XP");
  93        if (ph->config_size != LDM_DB_SIZE) {   /* 1 MiB in sectors. */
  94                /* Warn the user and continue, carefully. */
  95                ldm_info("Database is normally %u bytes, it claims to "
  96                        "be %llu bytes.", LDM_DB_SIZE,
  97                        (unsigned long long)ph->config_size);
  98        }
  99        if ((ph->logical_disk_size == 0) || (ph->logical_disk_start +
 100                        ph->logical_disk_size > ph->config_start)) {
 101                ldm_error("PRIVHEAD disk size doesn't match real disk size");
 102                return false;
 103        }
 104        if (uuid_parse(data + 0x0030, &ph->disk_id)) {
 105                ldm_error("PRIVHEAD contains an invalid GUID.");
 106                return false;
 107        }
 108        ldm_debug("Parsed PRIVHEAD successfully.");
 109        return true;
 110}
 111
 112/**
 113 * ldm_parse_tocblock - Read the LDM Database TOCBLOCK structure
 114 * @data:  Raw database TOCBLOCK structure loaded from the device
 115 * @toc:   In-memory toc structure in which to return parsed information
 116 *
 117 * This parses the LDM Database TOCBLOCK (table of contents) structure supplied
 118 * in @data and sets up the in-memory tocblock structure @toc with the obtained
 119 * information.
 120 *
 121 * N.B.  The *_start and *_size values returned in @toc are not range-checked.
 122 *
 123 * Return:  'true'   @toc contains the TOCBLOCK data
 124 *          'false'  @toc contents are undefined
 125 */
 126static bool ldm_parse_tocblock (const u8 *data, struct tocblock *toc)
 127{
 128        BUG_ON (!data || !toc);
 129
 130        if (MAGIC_TOCBLOCK != get_unaligned_be64(data)) {
 131                ldm_crit ("Cannot find TOCBLOCK, database may be corrupt.");
 132                return false;
 133        }
 134        strncpy (toc->bitmap1_name, data + 0x24, sizeof (toc->bitmap1_name));
 135        toc->bitmap1_name[sizeof (toc->bitmap1_name) - 1] = 0;
 136        toc->bitmap1_start = get_unaligned_be64(data + 0x2E);
 137        toc->bitmap1_size  = get_unaligned_be64(data + 0x36);
 138
 139        if (strncmp (toc->bitmap1_name, TOC_BITMAP1,
 140                        sizeof (toc->bitmap1_name)) != 0) {
 141                ldm_crit ("TOCBLOCK's first bitmap is '%s', should be '%s'.",
 142                                TOC_BITMAP1, toc->bitmap1_name);
 143                return false;
 144        }
 145        strncpy (toc->bitmap2_name, data + 0x46, sizeof (toc->bitmap2_name));
 146        toc->bitmap2_name[sizeof (toc->bitmap2_name) - 1] = 0;
 147        toc->bitmap2_start = get_unaligned_be64(data + 0x50);
 148        toc->bitmap2_size  = get_unaligned_be64(data + 0x58);
 149        if (strncmp (toc->bitmap2_name, TOC_BITMAP2,
 150                        sizeof (toc->bitmap2_name)) != 0) {
 151                ldm_crit ("TOCBLOCK's second bitmap is '%s', should be '%s'.",
 152                                TOC_BITMAP2, toc->bitmap2_name);
 153                return false;
 154        }
 155        ldm_debug ("Parsed TOCBLOCK successfully.");
 156        return true;
 157}
 158
 159/**
 160 * ldm_parse_vmdb - Read the LDM Database VMDB structure
 161 * @data:  Raw database VMDB structure loaded from the device
 162 * @vm:    In-memory vmdb structure in which to return parsed information
 163 *
 164 * This parses the LDM Database VMDB structure supplied in @data and sets up
 165 * the in-memory vmdb structure @vm with the obtained information.
 166 *
 167 * N.B.  The *_start, *_size and *_seq values will be range-checked later.
 168 *
 169 * Return:  'true'   @vm contains VMDB info
 170 *          'false'  @vm contents are undefined
 171 */
 172static bool ldm_parse_vmdb (const u8 *data, struct vmdb *vm)
 173{
 174        BUG_ON (!data || !vm);
 175
 176        if (MAGIC_VMDB != get_unaligned_be32(data)) {
 177                ldm_crit ("Cannot find the VMDB, database may be corrupt.");
 178                return false;
 179        }
 180
 181        vm->ver_major = get_unaligned_be16(data + 0x12);
 182        vm->ver_minor = get_unaligned_be16(data + 0x14);
 183        if ((vm->ver_major != 4) || (vm->ver_minor != 10)) {
 184                ldm_error ("Expected VMDB version %d.%d, got %d.%d. "
 185                        "Aborting.", 4, 10, vm->ver_major, vm->ver_minor);
 186                return false;
 187        }
 188
 189        vm->vblk_size     = get_unaligned_be32(data + 0x08);
 190        if (vm->vblk_size == 0) {
 191                ldm_error ("Illegal VBLK size");
 192                return false;
 193        }
 194
 195        vm->vblk_offset   = get_unaligned_be32(data + 0x0C);
 196        vm->last_vblk_seq = get_unaligned_be32(data + 0x04);
 197
 198        ldm_debug ("Parsed VMDB successfully.");
 199        return true;
 200}
 201
 202/**
 203 * ldm_compare_privheads - Compare two privhead objects
 204 * @ph1:  First privhead
 205 * @ph2:  Second privhead
 206 *
 207 * This compares the two privhead structures @ph1 and @ph2.
 208 *
 209 * Return:  'true'   Identical
 210 *          'false'  Different
 211 */
 212static bool ldm_compare_privheads (const struct privhead *ph1,
 213                                   const struct privhead *ph2)
 214{
 215        BUG_ON (!ph1 || !ph2);
 216
 217        return ((ph1->ver_major          == ph2->ver_major)             &&
 218                (ph1->ver_minor          == ph2->ver_minor)             &&
 219                (ph1->logical_disk_start == ph2->logical_disk_start)    &&
 220                (ph1->logical_disk_size  == ph2->logical_disk_size)     &&
 221                (ph1->config_start       == ph2->config_start)          &&
 222                (ph1->config_size        == ph2->config_size)           &&
 223                uuid_equal(&ph1->disk_id, &ph2->disk_id));
 224}
 225
 226/**
 227 * ldm_compare_tocblocks - Compare two tocblock objects
 228 * @toc1:  First toc
 229 * @toc2:  Second toc
 230 *
 231 * This compares the two tocblock structures @toc1 and @toc2.
 232 *
 233 * Return:  'true'   Identical
 234 *          'false'  Different
 235 */
 236static bool ldm_compare_tocblocks (const struct tocblock *toc1,
 237                                   const struct tocblock *toc2)
 238{
 239        BUG_ON (!toc1 || !toc2);
 240
 241        return ((toc1->bitmap1_start == toc2->bitmap1_start)    &&
 242                (toc1->bitmap1_size  == toc2->bitmap1_size)     &&
 243                (toc1->bitmap2_start == toc2->bitmap2_start)    &&
 244                (toc1->bitmap2_size  == toc2->bitmap2_size)     &&
 245                !strncmp (toc1->bitmap1_name, toc2->bitmap1_name,
 246                        sizeof (toc1->bitmap1_name))            &&
 247                !strncmp (toc1->bitmap2_name, toc2->bitmap2_name,
 248                        sizeof (toc1->bitmap2_name)));
 249}
 250
 251/**
 252 * ldm_validate_privheads - Compare the primary privhead with its backups
 253 * @state: Partition check state including device holding the LDM Database
 254 * @ph1:   Memory struct to fill with ph contents
 255 *
 256 * Read and compare all three privheads from disk.
 257 *
 258 * The privheads on disk show the size and location of the main disk area and
 259 * the configuration area (the database).  The values are range-checked against
 260 * @hd, which contains the real size of the disk.
 261 *
 262 * Return:  'true'   Success
 263 *          'false'  Error
 264 */
 265static bool ldm_validate_privheads(struct parsed_partitions *state,
 266                                   struct privhead *ph1)
 267{
 268        static const int off[3] = { OFF_PRIV1, OFF_PRIV2, OFF_PRIV3 };
 269        struct privhead *ph[3] = { ph1 };
 270        Sector sect;
 271        u8 *data;
 272        bool result = false;
 273        long num_sects;
 274        int i;
 275
 276        BUG_ON (!state || !ph1);
 277
 278        ph[1] = kmalloc (sizeof (*ph[1]), GFP_KERNEL);
 279        ph[2] = kmalloc (sizeof (*ph[2]), GFP_KERNEL);
 280        if (!ph[1] || !ph[2]) {
 281                ldm_crit ("Out of memory.");
 282                goto out;
 283        }
 284
 285        /* off[1 & 2] are relative to ph[0]->config_start */
 286        ph[0]->config_start = 0;
 287
 288        /* Read and parse privheads */
 289        for (i = 0; i < 3; i++) {
 290                data = read_part_sector(state, ph[0]->config_start + off[i],
 291                                        &sect);
 292                if (!data) {
 293                        ldm_crit ("Disk read failed.");
 294                        goto out;
 295                }
 296                result = ldm_parse_privhead (data, ph[i]);
 297                put_dev_sector (sect);
 298                if (!result) {
 299                        ldm_error ("Cannot find PRIVHEAD %d.", i+1); /* Log again */
 300                        if (i < 2)
 301                                goto out;       /* Already logged */
 302                        else
 303                                break;  /* FIXME ignore for now, 3rd PH can fail on odd-sized disks */
 304                }
 305        }
 306
 307        num_sects = state->bdev->bd_inode->i_size >> 9;
 308
 309        if ((ph[0]->config_start > num_sects) ||
 310           ((ph[0]->config_start + ph[0]->config_size) > num_sects)) {
 311                ldm_crit ("Database extends beyond the end of the disk.");
 312                goto out;
 313        }
 314
 315        if ((ph[0]->logical_disk_start > ph[0]->config_start) ||
 316           ((ph[0]->logical_disk_start + ph[0]->logical_disk_size)
 317                    > ph[0]->config_start)) {
 318                ldm_crit ("Disk and database overlap.");
 319                goto out;
 320        }
 321
 322        if (!ldm_compare_privheads (ph[0], ph[1])) {
 323                ldm_crit ("Primary and backup PRIVHEADs don't match.");
 324                goto out;
 325        }
 326        /* FIXME ignore this for now
 327        if (!ldm_compare_privheads (ph[0], ph[2])) {
 328                ldm_crit ("Primary and backup PRIVHEADs don't match.");
 329                goto out;
 330        }*/
 331        ldm_debug ("Validated PRIVHEADs successfully.");
 332        result = true;
 333out:
 334        kfree (ph[1]);
 335        kfree (ph[2]);
 336        return result;
 337}
 338
 339/**
 340 * ldm_validate_tocblocks - Validate the table of contents and its backups
 341 * @state: Partition check state including device holding the LDM Database
 342 * @base:  Offset, into @state->bdev, of the database
 343 * @ldb:   Cache of the database structures
 344 *
 345 * Find and compare the four tables of contents of the LDM Database stored on
 346 * @state->bdev and return the parsed information into @toc1.
 347 *
 348 * The offsets and sizes of the configs are range-checked against a privhead.
 349 *
 350 * Return:  'true'   @toc1 contains validated TOCBLOCK info
 351 *          'false'  @toc1 contents are undefined
 352 */
 353static bool ldm_validate_tocblocks(struct parsed_partitions *state,
 354                                   unsigned long base, struct ldmdb *ldb)
 355{
 356        static const int off[4] = { OFF_TOCB1, OFF_TOCB2, OFF_TOCB3, OFF_TOCB4};
 357        struct tocblock *tb[4];
 358        struct privhead *ph;
 359        Sector sect;
 360        u8 *data;
 361        int i, nr_tbs;
 362        bool result = false;
 363
 364        BUG_ON(!state || !ldb);
 365        ph = &ldb->ph;
 366        tb[0] = &ldb->toc;
 367        tb[1] = kmalloc_array(3, sizeof(*tb[1]), GFP_KERNEL);
 368        if (!tb[1]) {
 369                ldm_crit("Out of memory.");
 370                goto err;
 371        }
 372        tb[2] = (struct tocblock*)((u8*)tb[1] + sizeof(*tb[1]));
 373        tb[3] = (struct tocblock*)((u8*)tb[2] + sizeof(*tb[2]));
 374        /*
 375         * Try to read and parse all four TOCBLOCKs.
 376         *
 377         * Windows Vista LDM v2.12 does not always have all four TOCBLOCKs so
 378         * skip any that fail as long as we get at least one valid TOCBLOCK.
 379         */
 380        for (nr_tbs = i = 0; i < 4; i++) {
 381                data = read_part_sector(state, base + off[i], &sect);
 382                if (!data) {
 383                        ldm_error("Disk read failed for TOCBLOCK %d.", i);
 384                        continue;
 385                }
 386                if (ldm_parse_tocblock(data, tb[nr_tbs]))
 387                        nr_tbs++;
 388                put_dev_sector(sect);
 389        }
 390        if (!nr_tbs) {
 391                ldm_crit("Failed to find a valid TOCBLOCK.");
 392                goto err;
 393        }
 394        /* Range check the TOCBLOCK against a privhead. */
 395        if (((tb[0]->bitmap1_start + tb[0]->bitmap1_size) > ph->config_size) ||
 396                        ((tb[0]->bitmap2_start + tb[0]->bitmap2_size) >
 397                        ph->config_size)) {
 398                ldm_crit("The bitmaps are out of range.  Giving up.");
 399                goto err;
 400        }
 401        /* Compare all loaded TOCBLOCKs. */
 402        for (i = 1; i < nr_tbs; i++) {
 403                if (!ldm_compare_tocblocks(tb[0], tb[i])) {
 404                        ldm_crit("TOCBLOCKs 0 and %d do not match.", i);
 405                        goto err;
 406                }
 407        }
 408        ldm_debug("Validated %d TOCBLOCKs successfully.", nr_tbs);
 409        result = true;
 410err:
 411        kfree(tb[1]);
 412        return result;
 413}
 414
 415/**
 416 * ldm_validate_vmdb - Read the VMDB and validate it
 417 * @state: Partition check state including device holding the LDM Database
 418 * @base:  Offset, into @bdev, of the database
 419 * @ldb:   Cache of the database structures
 420 *
 421 * Find the vmdb of the LDM Database stored on @bdev and return the parsed
 422 * information in @ldb.
 423 *
 424 * Return:  'true'   @ldb contains validated VBDB info
 425 *          'false'  @ldb contents are undefined
 426 */
 427static bool ldm_validate_vmdb(struct parsed_partitions *state,
 428                              unsigned long base, struct ldmdb *ldb)
 429{
 430        Sector sect;
 431        u8 *data;
 432        bool result = false;
 433        struct vmdb *vm;
 434        struct tocblock *toc;
 435
 436        BUG_ON (!state || !ldb);
 437
 438        vm  = &ldb->vm;
 439        toc = &ldb->toc;
 440
 441        data = read_part_sector(state, base + OFF_VMDB, &sect);
 442        if (!data) {
 443                ldm_crit ("Disk read failed.");
 444                return false;
 445        }
 446
 447        if (!ldm_parse_vmdb (data, vm))
 448                goto out;                               /* Already logged */
 449
 450        /* Are there uncommitted transactions? */
 451        if (get_unaligned_be16(data + 0x10) != 0x01) {
 452                ldm_crit ("Database is not in a consistent state.  Aborting.");
 453                goto out;
 454        }
 455
 456        if (vm->vblk_offset != 512)
 457                ldm_info ("VBLKs start at offset 0x%04x.", vm->vblk_offset);
 458
 459        /*
 460         * The last_vblkd_seq can be before the end of the vmdb, just make sure
 461         * it is not out of bounds.
 462         */
 463        if ((vm->vblk_size * vm->last_vblk_seq) > (toc->bitmap1_size << 9)) {
 464                ldm_crit ("VMDB exceeds allowed size specified by TOCBLOCK.  "
 465                                "Database is corrupt.  Aborting.");
 466                goto out;
 467        }
 468
 469        result = true;
 470out:
 471        put_dev_sector (sect);
 472        return result;
 473}
 474
 475
 476/**
 477 * ldm_validate_partition_table - Determine whether bdev might be a dynamic disk
 478 * @state: Partition check state including device holding the LDM Database
 479 *
 480 * This function provides a weak test to decide whether the device is a dynamic
 481 * disk or not.  It looks for an MS-DOS-style partition table containing at
 482 * least one partition of type 0x42 (formerly SFS, now used by Windows for
 483 * dynamic disks).
 484 *
 485 * N.B.  The only possible error can come from the read_part_sector and that is
 486 *       only likely to happen if the underlying device is strange.  If that IS
 487 *       the case we should return zero to let someone else try.
 488 *
 489 * Return:  'true'   @state->bdev is a dynamic disk
 490 *          'false'  @state->bdev is not a dynamic disk, or an error occurred
 491 */
 492static bool ldm_validate_partition_table(struct parsed_partitions *state)
 493{
 494        Sector sect;
 495        u8 *data;
 496        struct msdos_partition *p;
 497        int i;
 498        bool result = false;
 499
 500        BUG_ON(!state);
 501
 502        data = read_part_sector(state, 0, &sect);
 503        if (!data) {
 504                ldm_info ("Disk read failed.");
 505                return false;
 506        }
 507
 508        if (*(__le16*) (data + 0x01FE) != cpu_to_le16 (MSDOS_LABEL_MAGIC))
 509                goto out;
 510
 511        p = (struct msdos_partition *)(data + 0x01BE);
 512        for (i = 0; i < 4; i++, p++)
 513                if (p->sys_ind == LDM_PARTITION) {
 514                        result = true;
 515                        break;
 516                }
 517
 518        if (result)
 519                ldm_debug ("Found W2K dynamic disk partition type.");
 520
 521out:
 522        put_dev_sector (sect);
 523        return result;
 524}
 525
 526/**
 527 * ldm_get_disk_objid - Search a linked list of vblk's for a given Disk Id
 528 * @ldb:  Cache of the database structures
 529 *
 530 * The LDM Database contains a list of all partitions on all dynamic disks.
 531 * The primary PRIVHEAD, at the beginning of the physical disk, tells us
 532 * the GUID of this disk.  This function searches for the GUID in a linked
 533 * list of vblk's.
 534 *
 535 * Return:  Pointer, A matching vblk was found
 536 *          NULL,    No match, or an error
 537 */
 538static struct vblk * ldm_get_disk_objid (const struct ldmdb *ldb)
 539{
 540        struct list_head *item;
 541
 542        BUG_ON (!ldb);
 543
 544        list_for_each (item, &ldb->v_disk) {
 545                struct vblk *v = list_entry (item, struct vblk, list);
 546                if (uuid_equal(&v->vblk.disk.disk_id, &ldb->ph.disk_id))
 547                        return v;
 548        }
 549
 550        return NULL;
 551}
 552
 553/**
 554 * ldm_create_data_partitions - Create data partitions for this device
 555 * @pp:   List of the partitions parsed so far
 556 * @ldb:  Cache of the database structures
 557 *
 558 * The database contains ALL the partitions for ALL disk groups, so we need to
 559 * filter out this specific disk. Using the disk's object id, we can find all
 560 * the partitions in the database that belong to this disk.
 561 *
 562 * Add each partition in our database, to the parsed_partitions structure.
 563 *
 564 * N.B.  This function creates the partitions in the order it finds partition
 565 *       objects in the linked list.
 566 *
 567 * Return:  'true'   Partition created
 568 *          'false'  Error, probably a range checking problem
 569 */
 570static bool ldm_create_data_partitions (struct parsed_partitions *pp,
 571                                        const struct ldmdb *ldb)
 572{
 573        struct list_head *item;
 574        struct vblk *vb;
 575        struct vblk *disk;
 576        struct vblk_part *part;
 577        int part_num = 1;
 578
 579        BUG_ON (!pp || !ldb);
 580
 581        disk = ldm_get_disk_objid (ldb);
 582        if (!disk) {
 583                ldm_crit ("Can't find the ID of this disk in the database.");
 584                return false;
 585        }
 586
 587        strlcat(pp->pp_buf, " [LDM]", PAGE_SIZE);
 588
 589        /* Create the data partitions */
 590        list_for_each (item, &ldb->v_part) {
 591                vb = list_entry (item, struct vblk, list);
 592                part = &vb->vblk.part;
 593
 594                if (part->disk_id != disk->obj_id)
 595                        continue;
 596
 597                put_partition (pp, part_num, ldb->ph.logical_disk_start +
 598                                part->start, part->size);
 599                part_num++;
 600        }
 601
 602        strlcat(pp->pp_buf, "\n", PAGE_SIZE);
 603        return true;
 604}
 605
 606
 607/**
 608 * ldm_relative - Calculate the next relative offset
 609 * @buffer:  Block of data being worked on
 610 * @buflen:  Size of the block of data
 611 * @base:    Size of the previous fixed width fields
 612 * @offset:  Cumulative size of the previous variable-width fields
 613 *
 614 * Because many of the VBLK fields are variable-width, it's necessary
 615 * to calculate each offset based on the previous one and the length
 616 * of the field it pointed to.
 617 *
 618 * Return:  -1 Error, the calculated offset exceeded the size of the buffer
 619 *           n OK, a range-checked offset into buffer
 620 */
 621static int ldm_relative(const u8 *buffer, int buflen, int base, int offset)
 622{
 623
 624        base += offset;
 625        if (!buffer || offset < 0 || base > buflen) {
 626                if (!buffer)
 627                        ldm_error("!buffer");
 628                if (offset < 0)
 629                        ldm_error("offset (%d) < 0", offset);
 630                if (base > buflen)
 631                        ldm_error("base (%d) > buflen (%d)", base, buflen);
 632                return -1;
 633        }
 634        if (base + buffer[base] >= buflen) {
 635                ldm_error("base (%d) + buffer[base] (%d) >= buflen (%d)", base,
 636                                buffer[base], buflen);
 637                return -1;
 638        }
 639        return buffer[base] + offset + 1;
 640}
 641
 642/**
 643 * ldm_get_vnum - Convert a variable-width, big endian number, into cpu order
 644 * @block:  Pointer to the variable-width number to convert
 645 *
 646 * Large numbers in the LDM Database are often stored in a packed format.  Each
 647 * number is prefixed by a one byte width marker.  All numbers in the database
 648 * are stored in big-endian byte order.  This function reads one of these
 649 * numbers and returns the result
 650 *
 651 * N.B.  This function DOES NOT perform any range checking, though the most
 652 *       it will read is eight bytes.
 653 *
 654 * Return:  n A number
 655 *          0 Zero, or an error occurred
 656 */
 657static u64 ldm_get_vnum (const u8 *block)
 658{
 659        u64 tmp = 0;
 660        u8 length;
 661
 662        BUG_ON (!block);
 663
 664        length = *block++;
 665
 666        if (length && length <= 8)
 667                while (length--)
 668                        tmp = (tmp << 8) | *block++;
 669        else
 670                ldm_error ("Illegal length %d.", length);
 671
 672        return tmp;
 673}
 674
 675/**
 676 * ldm_get_vstr - Read a length-prefixed string into a buffer
 677 * @block:   Pointer to the length marker
 678 * @buffer:  Location to copy string to
 679 * @buflen:  Size of the output buffer
 680 *
 681 * Many of the strings in the LDM Database are not NULL terminated.  Instead
 682 * they are prefixed by a one byte length marker.  This function copies one of
 683 * these strings into a buffer.
 684 *
 685 * N.B.  This function DOES NOT perform any range checking on the input.
 686 *       If the buffer is too small, the output will be truncated.
 687 *
 688 * Return:  0, Error and @buffer contents are undefined
 689 *          n, String length in characters (excluding NULL)
 690 *          buflen-1, String was truncated.
 691 */
 692static int ldm_get_vstr (const u8 *block, u8 *buffer, int buflen)
 693{
 694        int length;
 695
 696        BUG_ON (!block || !buffer);
 697
 698        length = block[0];
 699        if (length >= buflen) {
 700                ldm_error ("Truncating string %d -> %d.", length, buflen);
 701                length = buflen - 1;
 702        }
 703        memcpy (buffer, block + 1, length);
 704        buffer[length] = 0;
 705        return length;
 706}
 707
 708
 709/**
 710 * ldm_parse_cmp3 - Read a raw VBLK Component object into a vblk structure
 711 * @buffer:  Block of data being worked on
 712 * @buflen:  Size of the block of data
 713 * @vb:      In-memory vblk in which to return information
 714 *
 715 * Read a raw VBLK Component object (version 3) into a vblk structure.
 716 *
 717 * Return:  'true'   @vb contains a Component VBLK
 718 *          'false'  @vb contents are not defined
 719 */
 720static bool ldm_parse_cmp3 (const u8 *buffer, int buflen, struct vblk *vb)
 721{
 722        int r_objid, r_name, r_vstate, r_child, r_parent, r_stripe, r_cols, len;
 723        struct vblk_comp *comp;
 724
 725        BUG_ON (!buffer || !vb);
 726
 727        r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
 728        r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);
 729        r_vstate = ldm_relative (buffer, buflen, 0x18, r_name);
 730        r_child  = ldm_relative (buffer, buflen, 0x1D, r_vstate);
 731        r_parent = ldm_relative (buffer, buflen, 0x2D, r_child);
 732
 733        if (buffer[0x12] & VBLK_FLAG_COMP_STRIPE) {
 734                r_stripe = ldm_relative (buffer, buflen, 0x2E, r_parent);
 735                r_cols   = ldm_relative (buffer, buflen, 0x2E, r_stripe);
 736                len = r_cols;
 737        } else {
 738                r_stripe = 0;
 739                r_cols   = 0;
 740                len = r_parent;
 741        }
 742        if (len < 0)
 743                return false;
 744
 745        len += VBLK_SIZE_CMP3;
 746        if (len != get_unaligned_be32(buffer + 0x14))
 747                return false;
 748
 749        comp = &vb->vblk.comp;
 750        ldm_get_vstr (buffer + 0x18 + r_name, comp->state,
 751                sizeof (comp->state));
 752        comp->type      = buffer[0x18 + r_vstate];
 753        comp->children  = ldm_get_vnum (buffer + 0x1D + r_vstate);
 754        comp->parent_id = ldm_get_vnum (buffer + 0x2D + r_child);
 755        comp->chunksize = r_stripe ? ldm_get_vnum (buffer+r_parent+0x2E) : 0;
 756
 757        return true;
 758}
 759
 760/**
 761 * ldm_parse_dgr3 - Read a raw VBLK Disk Group object into a vblk structure
 762 * @buffer:  Block of data being worked on
 763 * @buflen:  Size of the block of data
 764 * @vb:      In-memory vblk in which to return information
 765 *
 766 * Read a raw VBLK Disk Group object (version 3) into a vblk structure.
 767 *
 768 * Return:  'true'   @vb contains a Disk Group VBLK
 769 *          'false'  @vb contents are not defined
 770 */
 771static int ldm_parse_dgr3 (const u8 *buffer, int buflen, struct vblk *vb)
 772{
 773        int r_objid, r_name, r_diskid, r_id1, r_id2, len;
 774        struct vblk_dgrp *dgrp;
 775
 776        BUG_ON (!buffer || !vb);
 777
 778        r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
 779        r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);
 780        r_diskid = ldm_relative (buffer, buflen, 0x18, r_name);
 781
 782        if (buffer[0x12] & VBLK_FLAG_DGR3_IDS) {
 783                r_id1 = ldm_relative (buffer, buflen, 0x24, r_diskid);
 784                r_id2 = ldm_relative (buffer, buflen, 0x24, r_id1);
 785                len = r_id2;
 786        } else {
 787                r_id1 = 0;
 788                r_id2 = 0;
 789                len = r_diskid;
 790        }
 791        if (len < 0)
 792                return false;
 793
 794        len += VBLK_SIZE_DGR3;
 795        if (len != get_unaligned_be32(buffer + 0x14))
 796                return false;
 797
 798        dgrp = &vb->vblk.dgrp;
 799        ldm_get_vstr (buffer + 0x18 + r_name, dgrp->disk_id,
 800                sizeof (dgrp->disk_id));
 801        return true;
 802}
 803
 804/**
 805 * ldm_parse_dgr4 - Read a raw VBLK Disk Group object into a vblk structure
 806 * @buffer:  Block of data being worked on
 807 * @buflen:  Size of the block of data
 808 * @vb:      In-memory vblk in which to return information
 809 *
 810 * Read a raw VBLK Disk Group object (version 4) into a vblk structure.
 811 *
 812 * Return:  'true'   @vb contains a Disk Group VBLK
 813 *          'false'  @vb contents are not defined
 814 */
 815static bool ldm_parse_dgr4 (const u8 *buffer, int buflen, struct vblk *vb)
 816{
 817        char buf[64];
 818        int r_objid, r_name, r_id1, r_id2, len;
 819
 820        BUG_ON (!buffer || !vb);
 821
 822        r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
 823        r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);
 824
 825        if (buffer[0x12] & VBLK_FLAG_DGR4_IDS) {
 826                r_id1 = ldm_relative (buffer, buflen, 0x44, r_name);
 827                r_id2 = ldm_relative (buffer, buflen, 0x44, r_id1);
 828                len = r_id2;
 829        } else {
 830                r_id1 = 0;
 831                r_id2 = 0;
 832                len = r_name;
 833        }
 834        if (len < 0)
 835                return false;
 836
 837        len += VBLK_SIZE_DGR4;
 838        if (len != get_unaligned_be32(buffer + 0x14))
 839                return false;
 840
 841        ldm_get_vstr (buffer + 0x18 + r_objid, buf, sizeof (buf));
 842        return true;
 843}
 844
 845/**
 846 * ldm_parse_dsk3 - Read a raw VBLK Disk object into a vblk structure
 847 * @buffer:  Block of data being worked on
 848 * @buflen:  Size of the block of data
 849 * @vb:      In-memory vblk in which to return information
 850 *
 851 * Read a raw VBLK Disk object (version 3) into a vblk structure.
 852 *
 853 * Return:  'true'   @vb contains a Disk VBLK
 854 *          'false'  @vb contents are not defined
 855 */
 856static bool ldm_parse_dsk3 (const u8 *buffer, int buflen, struct vblk *vb)
 857{
 858        int r_objid, r_name, r_diskid, r_altname, len;
 859        struct vblk_disk *disk;
 860
 861        BUG_ON (!buffer || !vb);
 862
 863        r_objid   = ldm_relative (buffer, buflen, 0x18, 0);
 864        r_name    = ldm_relative (buffer, buflen, 0x18, r_objid);
 865        r_diskid  = ldm_relative (buffer, buflen, 0x18, r_name);
 866        r_altname = ldm_relative (buffer, buflen, 0x18, r_diskid);
 867        len = r_altname;
 868        if (len < 0)
 869                return false;
 870
 871        len += VBLK_SIZE_DSK3;
 872        if (len != get_unaligned_be32(buffer + 0x14))
 873                return false;
 874
 875        disk = &vb->vblk.disk;
 876        ldm_get_vstr (buffer + 0x18 + r_diskid, disk->alt_name,
 877                sizeof (disk->alt_name));
 878        if (uuid_parse(buffer + 0x19 + r_name, &disk->disk_id))
 879                return false;
 880
 881        return true;
 882}
 883
 884/**
 885 * ldm_parse_dsk4 - Read a raw VBLK Disk object into a vblk structure
 886 * @buffer:  Block of data being worked on
 887 * @buflen:  Size of the block of data
 888 * @vb:      In-memory vblk in which to return information
 889 *
 890 * Read a raw VBLK Disk object (version 4) into a vblk structure.
 891 *
 892 * Return:  'true'   @vb contains a Disk VBLK
 893 *          'false'  @vb contents are not defined
 894 */
 895static bool ldm_parse_dsk4 (const u8 *buffer, int buflen, struct vblk *vb)
 896{
 897        int r_objid, r_name, len;
 898        struct vblk_disk *disk;
 899
 900        BUG_ON (!buffer || !vb);
 901
 902        r_objid = ldm_relative (buffer, buflen, 0x18, 0);
 903        r_name  = ldm_relative (buffer, buflen, 0x18, r_objid);
 904        len     = r_name;
 905        if (len < 0)
 906                return false;
 907
 908        len += VBLK_SIZE_DSK4;
 909        if (len != get_unaligned_be32(buffer + 0x14))
 910                return false;
 911
 912        disk = &vb->vblk.disk;
 913        import_uuid(&disk->disk_id, buffer + 0x18 + r_name);
 914        return true;
 915}
 916
 917/**
 918 * ldm_parse_prt3 - Read a raw VBLK Partition object into a vblk structure
 919 * @buffer:  Block of data being worked on
 920 * @buflen:  Size of the block of data
 921 * @vb:      In-memory vblk in which to return information
 922 *
 923 * Read a raw VBLK Partition object (version 3) into a vblk structure.
 924 *
 925 * Return:  'true'   @vb contains a Partition VBLK
 926 *          'false'  @vb contents are not defined
 927 */
 928static bool ldm_parse_prt3(const u8 *buffer, int buflen, struct vblk *vb)
 929{
 930        int r_objid, r_name, r_size, r_parent, r_diskid, r_index, len;
 931        struct vblk_part *part;
 932
 933        BUG_ON(!buffer || !vb);
 934        r_objid = ldm_relative(buffer, buflen, 0x18, 0);
 935        if (r_objid < 0) {
 936                ldm_error("r_objid %d < 0", r_objid);
 937                return false;
 938        }
 939        r_name = ldm_relative(buffer, buflen, 0x18, r_objid);
 940        if (r_name < 0) {
 941                ldm_error("r_name %d < 0", r_name);
 942                return false;
 943        }
 944        r_size = ldm_relative(buffer, buflen, 0x34, r_name);
 945        if (r_size < 0) {
 946                ldm_error("r_size %d < 0", r_size);
 947                return false;
 948        }
 949        r_parent = ldm_relative(buffer, buflen, 0x34, r_size);
 950        if (r_parent < 0) {
 951                ldm_error("r_parent %d < 0", r_parent);
 952                return false;
 953        }
 954        r_diskid = ldm_relative(buffer, buflen, 0x34, r_parent);
 955        if (r_diskid < 0) {
 956                ldm_error("r_diskid %d < 0", r_diskid);
 957                return false;
 958        }
 959        if (buffer[0x12] & VBLK_FLAG_PART_INDEX) {
 960                r_index = ldm_relative(buffer, buflen, 0x34, r_diskid);
 961                if (r_index < 0) {
 962                        ldm_error("r_index %d < 0", r_index);
 963                        return false;
 964                }
 965                len = r_index;
 966        } else {
 967                r_index = 0;
 968                len = r_diskid;
 969        }
 970        if (len < 0) {
 971                ldm_error("len %d < 0", len);
 972                return false;
 973        }
 974        len += VBLK_SIZE_PRT3;
 975        if (len > get_unaligned_be32(buffer + 0x14)) {
 976                ldm_error("len %d > BE32(buffer + 0x14) %d", len,
 977                                get_unaligned_be32(buffer + 0x14));
 978                return false;
 979        }
 980        part = &vb->vblk.part;
 981        part->start = get_unaligned_be64(buffer + 0x24 + r_name);
 982        part->volume_offset = get_unaligned_be64(buffer + 0x2C + r_name);
 983        part->size = ldm_get_vnum(buffer + 0x34 + r_name);
 984        part->parent_id = ldm_get_vnum(buffer + 0x34 + r_size);
 985        part->disk_id = ldm_get_vnum(buffer + 0x34 + r_parent);
 986        if (vb->flags & VBLK_FLAG_PART_INDEX)
 987                part->partnum = buffer[0x35 + r_diskid];
 988        else
 989                part->partnum = 0;
 990        return true;
 991}
 992
 993/**
 994 * ldm_parse_vol5 - Read a raw VBLK Volume object into a vblk structure
 995 * @buffer:  Block of data being worked on
 996 * @buflen:  Size of the block of data
 997 * @vb:      In-memory vblk in which to return information
 998 *
 999 * Read a raw VBLK Volume object (version 5) into a vblk structure.
1000 *
1001 * Return:  'true'   @vb contains a Volume VBLK
1002 *          'false'  @vb contents are not defined
1003 */
1004static bool ldm_parse_vol5(const u8 *buffer, int buflen, struct vblk *vb)
1005{
1006        int r_objid, r_name, r_vtype, r_disable_drive_letter, r_child, r_size;
1007        int r_id1, r_id2, r_size2, r_drive, len;
1008        struct vblk_volu *volu;
1009
1010        BUG_ON(!buffer || !vb);
1011        r_objid = ldm_relative(buffer, buflen, 0x18, 0);
1012        if (r_objid < 0) {
1013                ldm_error("r_objid %d < 0", r_objid);
1014                return false;
1015        }
1016        r_name = ldm_relative(buffer, buflen, 0x18, r_objid);
1017        if (r_name < 0) {
1018                ldm_error("r_name %d < 0", r_name);
1019                return false;
1020        }
1021        r_vtype = ldm_relative(buffer, buflen, 0x18, r_name);
1022        if (r_vtype < 0) {
1023                ldm_error("r_vtype %d < 0", r_vtype);
1024                return false;
1025        }
1026        r_disable_drive_letter = ldm_relative(buffer, buflen, 0x18, r_vtype);
1027        if (r_disable_drive_letter < 0) {
1028                ldm_error("r_disable_drive_letter %d < 0",
1029                                r_disable_drive_letter);
1030                return false;
1031        }
1032        r_child = ldm_relative(buffer, buflen, 0x2D, r_disable_drive_letter);
1033        if (r_child < 0) {
1034                ldm_error("r_child %d < 0", r_child);
1035                return false;
1036        }
1037        r_size = ldm_relative(buffer, buflen, 0x3D, r_child);
1038        if (r_size < 0) {
1039                ldm_error("r_size %d < 0", r_size);
1040                return false;
1041        }
1042        if (buffer[0x12] & VBLK_FLAG_VOLU_ID1) {
1043                r_id1 = ldm_relative(buffer, buflen, 0x52, r_size);
1044                if (r_id1 < 0) {
1045                        ldm_error("r_id1 %d < 0", r_id1);
1046                        return false;
1047                }
1048        } else
1049                r_id1 = r_size;
1050        if (buffer[0x12] & VBLK_FLAG_VOLU_ID2) {
1051                r_id2 = ldm_relative(buffer, buflen, 0x52, r_id1);
1052                if (r_id2 < 0) {
1053                        ldm_error("r_id2 %d < 0", r_id2);
1054                        return false;
1055                }
1056        } else
1057                r_id2 = r_id1;
1058        if (buffer[0x12] & VBLK_FLAG_VOLU_SIZE) {
1059                r_size2 = ldm_relative(buffer, buflen, 0x52, r_id2);
1060                if (r_size2 < 0) {
1061                        ldm_error("r_size2 %d < 0", r_size2);
1062                        return false;
1063                }
1064        } else
1065                r_size2 = r_id2;
1066        if (buffer[0x12] & VBLK_FLAG_VOLU_DRIVE) {
1067                r_drive = ldm_relative(buffer, buflen, 0x52, r_size2);
1068                if (r_drive < 0) {
1069                        ldm_error("r_drive %d < 0", r_drive);
1070                        return false;
1071                }
1072        } else
1073                r_drive = r_size2;
1074        len = r_drive;
1075        if (len < 0) {
1076                ldm_error("len %d < 0", len);
1077                return false;
1078        }
1079        len += VBLK_SIZE_VOL5;
1080        if (len > get_unaligned_be32(buffer + 0x14)) {
1081                ldm_error("len %d > BE32(buffer + 0x14) %d", len,
1082                                get_unaligned_be32(buffer + 0x14));
1083                return false;
1084        }
1085        volu = &vb->vblk.volu;
1086        ldm_get_vstr(buffer + 0x18 + r_name, volu->volume_type,
1087                        sizeof(volu->volume_type));
1088        memcpy(volu->volume_state, buffer + 0x18 + r_disable_drive_letter,
1089                        sizeof(volu->volume_state));
1090        volu->size = ldm_get_vnum(buffer + 0x3D + r_child);
1091        volu->partition_type = buffer[0x41 + r_size];
1092        memcpy(volu->guid, buffer + 0x42 + r_size, sizeof(volu->guid));
1093        if (buffer[0x12] & VBLK_FLAG_VOLU_DRIVE) {
1094                ldm_get_vstr(buffer + 0x52 + r_size, volu->drive_hint,
1095                                sizeof(volu->drive_hint));
1096        }
1097        return true;
1098}
1099
1100/**
1101 * ldm_parse_vblk - Read a raw VBLK object into a vblk structure
1102 * @buf:  Block of data being worked on
1103 * @len:  Size of the block of data
1104 * @vb:   In-memory vblk in which to return information
1105 *
1106 * Read a raw VBLK object into a vblk structure.  This function just reads the
1107 * information common to all VBLK types, then delegates the rest of the work to
1108 * helper functions: ldm_parse_*.
1109 *
1110 * Return:  'true'   @vb contains a VBLK
1111 *          'false'  @vb contents are not defined
1112 */
1113static bool ldm_parse_vblk (const u8 *buf, int len, struct vblk *vb)
1114{
1115        bool result = false;
1116        int r_objid;
1117
1118        BUG_ON (!buf || !vb);
1119
1120        r_objid = ldm_relative (buf, len, 0x18, 0);
1121        if (r_objid < 0) {
1122                ldm_error ("VBLK header is corrupt.");
1123                return false;
1124        }
1125
1126        vb->flags  = buf[0x12];
1127        vb->type   = buf[0x13];
1128        vb->obj_id = ldm_get_vnum (buf + 0x18);
1129        ldm_get_vstr (buf+0x18+r_objid, vb->name, sizeof (vb->name));
1130
1131        switch (vb->type) {
1132                case VBLK_CMP3:  result = ldm_parse_cmp3 (buf, len, vb); break;
1133                case VBLK_DSK3:  result = ldm_parse_dsk3 (buf, len, vb); break;
1134                case VBLK_DSK4:  result = ldm_parse_dsk4 (buf, len, vb); break;
1135                case VBLK_DGR3:  result = ldm_parse_dgr3 (buf, len, vb); break;
1136                case VBLK_DGR4:  result = ldm_parse_dgr4 (buf, len, vb); break;
1137                case VBLK_PRT3:  result = ldm_parse_prt3 (buf, len, vb); break;
1138                case VBLK_VOL5:  result = ldm_parse_vol5 (buf, len, vb); break;
1139        }
1140
1141        if (result)
1142                ldm_debug ("Parsed VBLK 0x%llx (type: 0x%02x) ok.",
1143                         (unsigned long long) vb->obj_id, vb->type);
1144        else
1145                ldm_error ("Failed to parse VBLK 0x%llx (type: 0x%02x).",
1146                        (unsigned long long) vb->obj_id, vb->type);
1147
1148        return result;
1149}
1150
1151
1152/**
1153 * ldm_ldmdb_add - Adds a raw VBLK entry to the ldmdb database
1154 * @data:  Raw VBLK to add to the database
1155 * @len:   Size of the raw VBLK
1156 * @ldb:   Cache of the database structures
1157 *
1158 * The VBLKs are sorted into categories.  Partitions are also sorted by offset.
1159 *
1160 * N.B.  This function does not check the validity of the VBLKs.
1161 *
1162 * Return:  'true'   The VBLK was added
1163 *          'false'  An error occurred
1164 */
1165static bool ldm_ldmdb_add (u8 *data, int len, struct ldmdb *ldb)
1166{
1167        struct vblk *vb;
1168        struct list_head *item;
1169
1170        BUG_ON (!data || !ldb);
1171
1172        vb = kmalloc (sizeof (*vb), GFP_KERNEL);
1173        if (!vb) {
1174                ldm_crit ("Out of memory.");
1175                return false;
1176        }
1177
1178        if (!ldm_parse_vblk (data, len, vb)) {
1179                kfree(vb);
1180                return false;                   /* Already logged */
1181        }
1182
1183        /* Put vblk into the correct list. */
1184        switch (vb->type) {
1185        case VBLK_DGR3:
1186        case VBLK_DGR4:
1187                list_add (&vb->list, &ldb->v_dgrp);
1188                break;
1189        case VBLK_DSK3:
1190        case VBLK_DSK4:
1191                list_add (&vb->list, &ldb->v_disk);
1192                break;
1193        case VBLK_VOL5:
1194                list_add (&vb->list, &ldb->v_volu);
1195                break;
1196        case VBLK_CMP3:
1197                list_add (&vb->list, &ldb->v_comp);
1198                break;
1199        case VBLK_PRT3:
1200                /* Sort by the partition's start sector. */
1201                list_for_each (item, &ldb->v_part) {
1202                        struct vblk *v = list_entry (item, struct vblk, list);
1203                        if ((v->vblk.part.disk_id == vb->vblk.part.disk_id) &&
1204                            (v->vblk.part.start > vb->vblk.part.start)) {
1205                                list_add_tail (&vb->list, &v->list);
1206                                return true;
1207                        }
1208                }
1209                list_add_tail (&vb->list, &ldb->v_part);
1210                break;
1211        }
1212        return true;
1213}
1214
1215/**
1216 * ldm_frag_add - Add a VBLK fragment to a list
1217 * @data:   Raw fragment to be added to the list
1218 * @size:   Size of the raw fragment
1219 * @frags:  Linked list of VBLK fragments
1220 *
1221 * Fragmented VBLKs may not be consecutive in the database, so they are placed
1222 * in a list so they can be pieced together later.
1223 *
1224 * Return:  'true'   Success, the VBLK was added to the list
1225 *          'false'  Error, a problem occurred
1226 */
1227static bool ldm_frag_add (const u8 *data, int size, struct list_head *frags)
1228{
1229        struct frag *f;
1230        struct list_head *item;
1231        int rec, num, group;
1232
1233        BUG_ON (!data || !frags);
1234
1235        if (size < 2 * VBLK_SIZE_HEAD) {
1236                ldm_error("Value of size is too small.");
1237                return false;
1238        }
1239
1240        group = get_unaligned_be32(data + 0x08);
1241        rec   = get_unaligned_be16(data + 0x0C);
1242        num   = get_unaligned_be16(data + 0x0E);
1243        if ((num < 1) || (num > 4)) {
1244                ldm_error ("A VBLK claims to have %d parts.", num);
1245                return false;
1246        }
1247        if (rec >= num) {
1248                ldm_error("REC value (%d) exceeds NUM value (%d)", rec, num);
1249                return false;
1250        }
1251
1252        list_for_each (item, frags) {
1253                f = list_entry (item, struct frag, list);
1254                if (f->group == group)
1255                        goto found;
1256        }
1257
1258        f = kmalloc (sizeof (*f) + size*num, GFP_KERNEL);
1259        if (!f) {
1260                ldm_crit ("Out of memory.");
1261                return false;
1262        }
1263
1264        f->group = group;
1265        f->num   = num;
1266        f->rec   = rec;
1267        f->map   = 0xFF << num;
1268
1269        list_add_tail (&f->list, frags);
1270found:
1271        if (rec >= f->num) {
1272                ldm_error("REC value (%d) exceeds NUM value (%d)", rec, f->num);
1273                return false;
1274        }
1275        if (f->map & (1 << rec)) {
1276                ldm_error ("Duplicate VBLK, part %d.", rec);
1277                f->map &= 0x7F;                 /* Mark the group as broken */
1278                return false;
1279        }
1280        f->map |= (1 << rec);
1281        if (!rec)
1282                memcpy(f->data, data, VBLK_SIZE_HEAD);
1283        data += VBLK_SIZE_HEAD;
1284        size -= VBLK_SIZE_HEAD;
1285        memcpy(f->data + VBLK_SIZE_HEAD + rec * size, data, size);
1286        return true;
1287}
1288
1289/**
1290 * ldm_frag_free - Free a linked list of VBLK fragments
1291 * @list:  Linked list of fragments
1292 *
1293 * Free a linked list of VBLK fragments
1294 *
1295 * Return:  none
1296 */
1297static void ldm_frag_free (struct list_head *list)
1298{
1299        struct list_head *item, *tmp;
1300
1301        BUG_ON (!list);
1302
1303        list_for_each_safe (item, tmp, list)
1304                kfree (list_entry (item, struct frag, list));
1305}
1306
1307/**
1308 * ldm_frag_commit - Validate fragmented VBLKs and add them to the database
1309 * @frags:  Linked list of VBLK fragments
1310 * @ldb:    Cache of the database structures
1311 *
1312 * Now that all the fragmented VBLKs have been collected, they must be added to
1313 * the database for later use.
1314 *
1315 * Return:  'true'   All the fragments we added successfully
1316 *          'false'  One or more of the fragments we invalid
1317 */
1318static bool ldm_frag_commit (struct list_head *frags, struct ldmdb *ldb)
1319{
1320        struct frag *f;
1321        struct list_head *item;
1322
1323        BUG_ON (!frags || !ldb);
1324
1325        list_for_each (item, frags) {
1326                f = list_entry (item, struct frag, list);
1327
1328                if (f->map != 0xFF) {
1329                        ldm_error ("VBLK group %d is incomplete (0x%02x).",
1330                                f->group, f->map);
1331                        return false;
1332                }
1333
1334                if (!ldm_ldmdb_add (f->data, f->num*ldb->vm.vblk_size, ldb))
1335                        return false;           /* Already logged */
1336        }
1337        return true;
1338}
1339
1340/**
1341 * ldm_get_vblks - Read the on-disk database of VBLKs into memory
1342 * @state: Partition check state including device holding the LDM Database
1343 * @base:  Offset, into @state->bdev, of the database
1344 * @ldb:   Cache of the database structures
1345 *
1346 * To use the information from the VBLKs, they need to be read from the disk,
1347 * unpacked and validated.  We cache them in @ldb according to their type.
1348 *
1349 * Return:  'true'   All the VBLKs were read successfully
1350 *          'false'  An error occurred
1351 */
1352static bool ldm_get_vblks(struct parsed_partitions *state, unsigned long base,
1353                          struct ldmdb *ldb)
1354{
1355        int size, perbuf, skip, finish, s, v, recs;
1356        u8 *data = NULL;
1357        Sector sect;
1358        bool result = false;
1359        LIST_HEAD (frags);
1360
1361        BUG_ON(!state || !ldb);
1362
1363        size   = ldb->vm.vblk_size;
1364        perbuf = 512 / size;
1365        skip   = ldb->vm.vblk_offset >> 9;              /* Bytes to sectors */
1366        finish = (size * ldb->vm.last_vblk_seq) >> 9;
1367
1368        for (s = skip; s < finish; s++) {               /* For each sector */
1369                data = read_part_sector(state, base + OFF_VMDB + s, &sect);
1370                if (!data) {
1371                        ldm_crit ("Disk read failed.");
1372                        goto out;
1373                }
1374
1375                for (v = 0; v < perbuf; v++, data+=size) {  /* For each vblk */
1376                        if (MAGIC_VBLK != get_unaligned_be32(data)) {
1377                                ldm_error ("Expected to find a VBLK.");
1378                                goto out;
1379                        }
1380
1381                        recs = get_unaligned_be16(data + 0x0E); /* Number of records */
1382                        if (recs == 1) {
1383                                if (!ldm_ldmdb_add (data, size, ldb))
1384                                        goto out;       /* Already logged */
1385                        } else if (recs > 1) {
1386                                if (!ldm_frag_add (data, size, &frags))
1387                                        goto out;       /* Already logged */
1388                        }
1389                        /* else Record is not in use, ignore it. */
1390                }
1391                put_dev_sector (sect);
1392                data = NULL;
1393        }
1394
1395        result = ldm_frag_commit (&frags, ldb); /* Failures, already logged */
1396out:
1397        if (data)
1398                put_dev_sector (sect);
1399        ldm_frag_free (&frags);
1400
1401        return result;
1402}
1403
1404/**
1405 * ldm_free_vblks - Free a linked list of vblk's
1406 * @lh:  Head of a linked list of struct vblk
1407 *
1408 * Free a list of vblk's and free the memory used to maintain the list.
1409 *
1410 * Return:  none
1411 */
1412static void ldm_free_vblks (struct list_head *lh)
1413{
1414        struct list_head *item, *tmp;
1415
1416        BUG_ON (!lh);
1417
1418        list_for_each_safe (item, tmp, lh)
1419                kfree (list_entry (item, struct vblk, list));
1420}
1421
1422
1423/**
1424 * ldm_partition - Find out whether a device is a dynamic disk and handle it
1425 * @state: Partition check state including device holding the LDM Database
1426 *
1427 * This determines whether the device @bdev is a dynamic disk and if so creates
1428 * the partitions necessary in the gendisk structure pointed to by @hd.
1429 *
1430 * We create a dummy device 1, which contains the LDM database, and then create
1431 * each partition described by the LDM database in sequence as devices 2+. For
1432 * example, if the device is hda, we would have: hda1: LDM database, hda2, hda3,
1433 * and so on: the actual data containing partitions.
1434 *
1435 * Return:  1 Success, @state->bdev is a dynamic disk and we handled it
1436 *          0 Success, @state->bdev is not a dynamic disk
1437 *         -1 An error occurred before enough information had been read
1438 *            Or @state->bdev is a dynamic disk, but it may be corrupted
1439 */
1440int ldm_partition(struct parsed_partitions *state)
1441{
1442        struct ldmdb  *ldb;
1443        unsigned long base;
1444        int result = -1;
1445
1446        BUG_ON(!state);
1447
1448        /* Look for signs of a Dynamic Disk */
1449        if (!ldm_validate_partition_table(state))
1450                return 0;
1451
1452        ldb = kmalloc (sizeof (*ldb), GFP_KERNEL);
1453        if (!ldb) {
1454                ldm_crit ("Out of memory.");
1455                goto out;
1456        }
1457
1458        /* Parse and check privheads. */
1459        if (!ldm_validate_privheads(state, &ldb->ph))
1460                goto out;               /* Already logged */
1461
1462        /* All further references are relative to base (database start). */
1463        base = ldb->ph.config_start;
1464
1465        /* Parse and check tocs and vmdb. */
1466        if (!ldm_validate_tocblocks(state, base, ldb) ||
1467            !ldm_validate_vmdb(state, base, ldb))
1468                goto out;               /* Already logged */
1469
1470        /* Initialize vblk lists in ldmdb struct */
1471        INIT_LIST_HEAD (&ldb->v_dgrp);
1472        INIT_LIST_HEAD (&ldb->v_disk);
1473        INIT_LIST_HEAD (&ldb->v_volu);
1474        INIT_LIST_HEAD (&ldb->v_comp);
1475        INIT_LIST_HEAD (&ldb->v_part);
1476
1477        if (!ldm_get_vblks(state, base, ldb)) {
1478                ldm_crit ("Failed to read the VBLKs from the database.");
1479                goto cleanup;
1480        }
1481
1482        /* Finally, create the data partition devices. */
1483        if (ldm_create_data_partitions(state, ldb)) {
1484                ldm_debug ("Parsed LDM database successfully.");
1485                result = 1;
1486        }
1487        /* else Already logged */
1488
1489cleanup:
1490        ldm_free_vblks (&ldb->v_dgrp);
1491        ldm_free_vblks (&ldb->v_disk);
1492        ldm_free_vblks (&ldb->v_volu);
1493        ldm_free_vblks (&ldb->v_comp);
1494        ldm_free_vblks (&ldb->v_part);
1495out:
1496        kfree (ldb);
1497        return result;
1498}
1499