block/partitions/ldm.c

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
__printf
ldm_parse_privhead
ldm_parse_tocblock
ldm_parse_vmdb
ldm_compare_privheads
ldm_compare_tocblocks
ldm_validate_privheads
ldm_validate_tocblocks
ldm_validate_vmdb
ldm_validate_partition_table
ldm_get_disk_objid
ldm_create_data_partitions
ldm_relative
ldm_get_vnum
ldm_get_vstr
ldm_parse_cmp3
ldm_parse_dgr3
ldm_parse_dgr4
ldm_parse_dsk3
ldm_parse_dsk4
ldm_parse_prt3
ldm_parse_vol5
ldm_parse_vblk
ldm_ldmdb_add
ldm_frag_add
ldm_frag_free
ldm_frag_commit
ldm_get_vblks
ldm_free_vblks
ldm_partition
   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 
  18 #include "ldm.h"
  19 #include "check.h"
  20 #include "msdos.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 
  40 static __printf(3, 4)
  41 void _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  */
  67 static 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  */
 126 static 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  */
 172 static 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  */
 212 static 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  */
 236 static 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  */
 265 static 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;
 333 out:
 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  */
 353 static 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;
 410 err:
 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  */
 427 static 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;
 470 out:
 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  */
 492 static bool ldm_validate_partition_table(struct parsed_partitions *state)
 493 {
 494         Sector sect;
 495         u8 *data;
 496         struct 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 partition*)(data + 0x01BE);
 512         for (i = 0; i < 4; i++, p++)
 513                 if (SYS_IND (p) == LDM_PARTITION) {
 514                         result = true;
 515                         break;
 516                 }
 517 
 518         if (result)
 519                 ldm_debug ("Found W2K dynamic disk partition type.");
 520 
 521 out:
 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  */
 538 static 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  */
 570 static 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  */
 621 static 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  */
 657 static 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  */
 692 static 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  */
 720 static 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  */
 771 static 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  */
 815 static 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  */
 856 static 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  */
 895 static 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         uuid_copy(&disk->disk_id, (uuid_t *)(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  */
 928 static 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  */
1004 static 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  */
1113 static 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  */
1165 static 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  */
1227 static 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 to 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);
1270 found:
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  */
1297 static 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  */
1318 static 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  */
1352 static 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 */
1396 out:
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  */
1412 static 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  */
1440 int 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 
1489 cleanup:
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);
1495 out:
1496         kfree (ldb);
1497         return result;
1498 }
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root/block/partitions/ldm.c

DEFINITIONS
