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TOMOYO Linux Cross Reference
Linux/block/partitions/ldm.c

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  1 /**
  2  * ldm - Support for Windows Logical Disk Manager (Dynamic Disks)
  3  *
  4  * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
  5  * Copyright (c) 2001-2012 Anton Altaparmakov
  6  * Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
  7  *
  8  * Documentation is available at http://www.linux-ntfs.org/doku.php?id=downloads 
  9  *
 10  * This program is free software; you can redistribute it and/or modify it under
 11  * the terms of the GNU General Public License as published by the Free Software
 12  * Foundation; either version 2 of the License, or (at your option) any later
 13  * version.
 14  *
 15  * This program is distributed in the hope that it will be useful, but WITHOUT
 16  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 17  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
 18  * details.
 19  *
 20  * You should have received a copy of the GNU General Public License along with
 21  * this program (in the main directory of the source in the file COPYING); if
 22  * not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 23  * Boston, MA  02111-1307  USA
 24  */
 25 
 26 #include <linux/slab.h>
 27 #include <linux/pagemap.h>
 28 #include <linux/stringify.h>
 29 #include <linux/kernel.h>
 30 #include <linux/uuid.h>
 31 
 32 #include "ldm.h"
 33 #include "check.h"
 34 #include "msdos.h"
 35 
 36 /**
 37  * ldm_debug/info/error/crit - Output an error message
 38  * @f:    A printf format string containing the message
 39  * @...:  Variables to substitute into @f
 40  *
 41  * ldm_debug() writes a DEBUG level message to the syslog but only if the
 42  * driver was compiled with debug enabled. Otherwise, the call turns into a NOP.
 43  */
 44 #ifndef CONFIG_LDM_DEBUG
 45 #define ldm_debug(...)  do {} while (0)
 46 #else
 47 #define ldm_debug(f, a...) _ldm_printk (KERN_DEBUG, __func__, f, ##a)
 48 #endif
 49 
 50 #define ldm_crit(f, a...)  _ldm_printk (KERN_CRIT,  __func__, f, ##a)
 51 #define ldm_error(f, a...) _ldm_printk (KERN_ERR,   __func__, f, ##a)
 52 #define ldm_info(f, a...)  _ldm_printk (KERN_INFO,  __func__, f, ##a)
 53 
 54 static __printf(3, 4)
 55 void _ldm_printk(const char *level, const char *function, const char *fmt, ...)
 56 {
 57         struct va_format vaf;
 58         va_list args;
 59 
 60         va_start (args, fmt);
 61 
 62         vaf.fmt = fmt;
 63         vaf.va = &args;
 64 
 65         printk("%s%s(): %pV\n", level, function, &vaf);
 66 
 67         va_end(args);
 68 }
 69 
 70 /**
 71  * ldm_parse_privhead - Read the LDM Database PRIVHEAD structure
 72  * @data:  Raw database PRIVHEAD structure loaded from the device
 73  * @ph:    In-memory privhead structure in which to return parsed information
 74  *
 75  * This parses the LDM database PRIVHEAD structure supplied in @data and
 76  * sets up the in-memory privhead structure @ph with the obtained information.
 77  *
 78  * Return:  'true'   @ph contains the PRIVHEAD data
 79  *          'false'  @ph contents are undefined
 80  */
 81 static bool ldm_parse_privhead(const u8 *data, struct privhead *ph)
 82 {
 83         bool is_vista = false;
 84 
 85         BUG_ON(!data || !ph);
 86         if (MAGIC_PRIVHEAD != get_unaligned_be64(data)) {
 87                 ldm_error("Cannot find PRIVHEAD structure. LDM database is"
 88                         " corrupt. Aborting.");
 89                 return false;
 90         }
 91         ph->ver_major = get_unaligned_be16(data + 0x000C);
 92         ph->ver_minor = get_unaligned_be16(data + 0x000E);
 93         ph->logical_disk_start = get_unaligned_be64(data + 0x011B);
 94         ph->logical_disk_size = get_unaligned_be64(data + 0x0123);
 95         ph->config_start = get_unaligned_be64(data + 0x012B);
 96         ph->config_size = get_unaligned_be64(data + 0x0133);
 97         /* Version 2.11 is Win2k/XP and version 2.12 is Vista. */
 98         if (ph->ver_major == 2 && ph->ver_minor == 12)
 99                 is_vista = true;
100         if (!is_vista && (ph->ver_major != 2 || ph->ver_minor != 11)) {
101                 ldm_error("Expected PRIVHEAD version 2.11 or 2.12, got %d.%d."
102                         " Aborting.", ph->ver_major, ph->ver_minor);
103                 return false;
104         }
105         ldm_debug("PRIVHEAD version %d.%d (Windows %s).", ph->ver_major,
106                         ph->ver_minor, is_vista ? "Vista" : "2000/XP");
107         if (ph->config_size != LDM_DB_SIZE) {   /* 1 MiB in sectors. */
108                 /* Warn the user and continue, carefully. */
109                 ldm_info("Database is normally %u bytes, it claims to "
110                         "be %llu bytes.", LDM_DB_SIZE,
111                         (unsigned long long)ph->config_size);
112         }
113         if ((ph->logical_disk_size == 0) || (ph->logical_disk_start +
114                         ph->logical_disk_size > ph->config_start)) {
115                 ldm_error("PRIVHEAD disk size doesn't match real disk size");
116                 return false;
117         }
118         if (uuid_be_to_bin(data + 0x0030, (uuid_be *)ph->disk_id)) {
119                 ldm_error("PRIVHEAD contains an invalid GUID.");
120                 return false;
121         }
122         ldm_debug("Parsed PRIVHEAD successfully.");
123         return true;
124 }
125 
126 /**
127  * ldm_parse_tocblock - Read the LDM Database TOCBLOCK structure
128  * @data:  Raw database TOCBLOCK structure loaded from the device
129  * @toc:   In-memory toc structure in which to return parsed information
130  *
131  * This parses the LDM Database TOCBLOCK (table of contents) structure supplied
132  * in @data and sets up the in-memory tocblock structure @toc with the obtained
133  * information.
134  *
135  * N.B.  The *_start and *_size values returned in @toc are not range-checked.
136  *
137  * Return:  'true'   @toc contains the TOCBLOCK data
138  *          'false'  @toc contents are undefined
139  */
140 static bool ldm_parse_tocblock (const u8 *data, struct tocblock *toc)
141 {
142         BUG_ON (!data || !toc);
143 
144         if (MAGIC_TOCBLOCK != get_unaligned_be64(data)) {
145                 ldm_crit ("Cannot find TOCBLOCK, database may be corrupt.");
146                 return false;
147         }
148         strncpy (toc->bitmap1_name, data + 0x24, sizeof (toc->bitmap1_name));
149         toc->bitmap1_name[sizeof (toc->bitmap1_name) - 1] = 0;
150         toc->bitmap1_start = get_unaligned_be64(data + 0x2E);
151         toc->bitmap1_size  = get_unaligned_be64(data + 0x36);
152 
153         if (strncmp (toc->bitmap1_name, TOC_BITMAP1,
154                         sizeof (toc->bitmap1_name)) != 0) {
155                 ldm_crit ("TOCBLOCK's first bitmap is '%s', should be '%s'.",
156                                 TOC_BITMAP1, toc->bitmap1_name);
157                 return false;
158         }
159         strncpy (toc->bitmap2_name, data + 0x46, sizeof (toc->bitmap2_name));
160         toc->bitmap2_name[sizeof (toc->bitmap2_name) - 1] = 0;
161         toc->bitmap2_start = get_unaligned_be64(data + 0x50);
162         toc->bitmap2_size  = get_unaligned_be64(data + 0x58);
163         if (strncmp (toc->bitmap2_name, TOC_BITMAP2,
164                         sizeof (toc->bitmap2_name)) != 0) {
165                 ldm_crit ("TOCBLOCK's second bitmap is '%s', should be '%s'.",
166                                 TOC_BITMAP2, toc->bitmap2_name);
167                 return false;
168         }
169         ldm_debug ("Parsed TOCBLOCK successfully.");
170         return true;
171 }
172 
173 /**
174  * ldm_parse_vmdb - Read the LDM Database VMDB structure
175  * @data:  Raw database VMDB structure loaded from the device
176  * @vm:    In-memory vmdb structure in which to return parsed information
177  *
178  * This parses the LDM Database VMDB structure supplied in @data and sets up
179  * the in-memory vmdb structure @vm with the obtained information.
180  *
181  * N.B.  The *_start, *_size and *_seq values will be range-checked later.
182  *
183  * Return:  'true'   @vm contains VMDB info
184  *          'false'  @vm contents are undefined
185  */
186 static bool ldm_parse_vmdb (const u8 *data, struct vmdb *vm)
187 {
188         BUG_ON (!data || !vm);
189 
190         if (MAGIC_VMDB != get_unaligned_be32(data)) {
191                 ldm_crit ("Cannot find the VMDB, database may be corrupt.");
192                 return false;
193         }
194 
195         vm->ver_major = get_unaligned_be16(data + 0x12);
196         vm->ver_minor = get_unaligned_be16(data + 0x14);
197         if ((vm->ver_major != 4) || (vm->ver_minor != 10)) {
198                 ldm_error ("Expected VMDB version %d.%d, got %d.%d. "
199                         "Aborting.", 4, 10, vm->ver_major, vm->ver_minor);
200                 return false;
201         }
202 
203         vm->vblk_size     = get_unaligned_be32(data + 0x08);
204         if (vm->vblk_size == 0) {
205                 ldm_error ("Illegal VBLK size");
206                 return false;
207         }
208 
209         vm->vblk_offset   = get_unaligned_be32(data + 0x0C);
210         vm->last_vblk_seq = get_unaligned_be32(data + 0x04);
211 
212         ldm_debug ("Parsed VMDB successfully.");
213         return true;
214 }
215 
216 /**
217  * ldm_compare_privheads - Compare two privhead objects
218  * @ph1:  First privhead
219  * @ph2:  Second privhead
220  *
221  * This compares the two privhead structures @ph1 and @ph2.
222  *
223  * Return:  'true'   Identical
224  *          'false'  Different
225  */
226 static bool ldm_compare_privheads (const struct privhead *ph1,
227                                    const struct privhead *ph2)
228 {
229         BUG_ON (!ph1 || !ph2);
230 
231         return ((ph1->ver_major          == ph2->ver_major)             &&
232                 (ph1->ver_minor          == ph2->ver_minor)             &&
233                 (ph1->logical_disk_start == ph2->logical_disk_start)    &&
234                 (ph1->logical_disk_size  == ph2->logical_disk_size)     &&
235                 (ph1->config_start       == ph2->config_start)          &&
236                 (ph1->config_size        == ph2->config_size)           &&
237                 !memcmp (ph1->disk_id, ph2->disk_id, GUID_SIZE));
238 }
239 
240 /**
241  * ldm_compare_tocblocks - Compare two tocblock objects
242  * @toc1:  First toc
243  * @toc2:  Second toc
244  *
245  * This compares the two tocblock structures @toc1 and @toc2.
246  *
247  * Return:  'true'   Identical
248  *          'false'  Different
249  */
250 static bool ldm_compare_tocblocks (const struct tocblock *toc1,
251                                    const struct tocblock *toc2)
252 {
253         BUG_ON (!toc1 || !toc2);
254 
255         return ((toc1->bitmap1_start == toc2->bitmap1_start)    &&
256                 (toc1->bitmap1_size  == toc2->bitmap1_size)     &&
257                 (toc1->bitmap2_start == toc2->bitmap2_start)    &&
258                 (toc1->bitmap2_size  == toc2->bitmap2_size)     &&
259                 !strncmp (toc1->bitmap1_name, toc2->bitmap1_name,
260                         sizeof (toc1->bitmap1_name))            &&
261                 !strncmp (toc1->bitmap2_name, toc2->bitmap2_name,
262                         sizeof (toc1->bitmap2_name)));
263 }
264 
265 /**
266  * ldm_validate_privheads - Compare the primary privhead with its backups
267  * @state: Partition check state including device holding the LDM Database
268  * @ph1:   Memory struct to fill with ph contents
269  *
270  * Read and compare all three privheads from disk.
271  *
272  * The privheads on disk show the size and location of the main disk area and
273  * the configuration area (the database).  The values are range-checked against
274  * @hd, which contains the real size of the disk.
275  *
276  * Return:  'true'   Success
277  *          'false'  Error
278  */
279 static bool ldm_validate_privheads(struct parsed_partitions *state,
280                                    struct privhead *ph1)
281 {
282         static const int off[3] = { OFF_PRIV1, OFF_PRIV2, OFF_PRIV3 };
283         struct privhead *ph[3] = { ph1 };
284         Sector sect;
285         u8 *data;
286         bool result = false;
287         long num_sects;
288         int i;
289 
290         BUG_ON (!state || !ph1);
291 
292         ph[1] = kmalloc (sizeof (*ph[1]), GFP_KERNEL);
293         ph[2] = kmalloc (sizeof (*ph[2]), GFP_KERNEL);
294         if (!ph[1] || !ph[2]) {
295                 ldm_crit ("Out of memory.");
296                 goto out;
297         }
298 
299         /* off[1 & 2] are relative to ph[0]->config_start */
300         ph[0]->config_start = 0;
301 
302         /* Read and parse privheads */
303         for (i = 0; i < 3; i++) {
304                 data = read_part_sector(state, ph[0]->config_start + off[i],
305                                         &sect);
306                 if (!data) {
307                         ldm_crit ("Disk read failed.");
308                         goto out;
309                 }
310                 result = ldm_parse_privhead (data, ph[i]);
311                 put_dev_sector (sect);
312                 if (!result) {
313                         ldm_error ("Cannot find PRIVHEAD %d.", i+1); /* Log again */
314                         if (i < 2)
315                                 goto out;       /* Already logged */
316                         else
317                                 break;  /* FIXME ignore for now, 3rd PH can fail on odd-sized disks */
318                 }
319         }
320 
321         num_sects = state->bdev->bd_inode->i_size >> 9;
322 
323         if ((ph[0]->config_start > num_sects) ||
324            ((ph[0]->config_start + ph[0]->config_size) > num_sects)) {
325                 ldm_crit ("Database extends beyond the end of the disk.");
326                 goto out;
327         }
328 
329         if ((ph[0]->logical_disk_start > ph[0]->config_start) ||
330            ((ph[0]->logical_disk_start + ph[0]->logical_disk_size)
331                     > ph[0]->config_start)) {
332                 ldm_crit ("Disk and database overlap.");
333                 goto out;
334         }
335 
336         if (!ldm_compare_privheads (ph[0], ph[1])) {
337                 ldm_crit ("Primary and backup PRIVHEADs don't match.");
338                 goto out;
339         }
340         /* FIXME ignore this for now
341         if (!ldm_compare_privheads (ph[0], ph[2])) {
342                 ldm_crit ("Primary and backup PRIVHEADs don't match.");
343                 goto out;
344         }*/
345         ldm_debug ("Validated PRIVHEADs successfully.");
346         result = true;
347 out:
348         kfree (ph[1]);
349         kfree (ph[2]);
350         return result;
351 }
352 
353 /**
354  * ldm_validate_tocblocks - Validate the table of contents and its backups
355  * @state: Partition check state including device holding the LDM Database
356  * @base:  Offset, into @state->bdev, of the database
357  * @ldb:   Cache of the database structures
358  *
359  * Find and compare the four tables of contents of the LDM Database stored on
360  * @state->bdev and return the parsed information into @toc1.
361  *
362  * The offsets and sizes of the configs are range-checked against a privhead.
363  *
364  * Return:  'true'   @toc1 contains validated TOCBLOCK info
365  *          'false'  @toc1 contents are undefined
366  */
367 static bool ldm_validate_tocblocks(struct parsed_partitions *state,
368                                    unsigned long base, struct ldmdb *ldb)
369 {
370         static const int off[4] = { OFF_TOCB1, OFF_TOCB2, OFF_TOCB3, OFF_TOCB4};
371         struct tocblock *tb[4];
372         struct privhead *ph;
373         Sector sect;
374         u8 *data;
375         int i, nr_tbs;
376         bool result = false;
377 
378         BUG_ON(!state || !ldb);
379         ph = &ldb->ph;
380         tb[0] = &ldb->toc;
381         tb[1] = kmalloc(sizeof(*tb[1]) * 3, GFP_KERNEL);
382         if (!tb[1]) {
383                 ldm_crit("Out of memory.");
384                 goto err;
385         }
386         tb[2] = (struct tocblock*)((u8*)tb[1] + sizeof(*tb[1]));
387         tb[3] = (struct tocblock*)((u8*)tb[2] + sizeof(*tb[2]));
388         /*
389          * Try to read and parse all four TOCBLOCKs.
390          *
391          * Windows Vista LDM v2.12 does not always have all four TOCBLOCKs so
392          * skip any that fail as long as we get at least one valid TOCBLOCK.
393          */
394         for (nr_tbs = i = 0; i < 4; i++) {
395                 data = read_part_sector(state, base + off[i], &sect);
396                 if (!data) {
397                         ldm_error("Disk read failed for TOCBLOCK %d.", i);
398                         continue;
399                 }
400                 if (ldm_parse_tocblock(data, tb[nr_tbs]))
401                         nr_tbs++;
402                 put_dev_sector(sect);
403         }
404         if (!nr_tbs) {
405                 ldm_crit("Failed to find a valid TOCBLOCK.");
406                 goto err;
407         }
408         /* Range check the TOCBLOCK against a privhead. */
409         if (((tb[0]->bitmap1_start + tb[0]->bitmap1_size) > ph->config_size) ||
410                         ((tb[0]->bitmap2_start + tb[0]->bitmap2_size) >
411                         ph->config_size)) {
412                 ldm_crit("The bitmaps are out of range.  Giving up.");
413                 goto err;
414         }
415         /* Compare all loaded TOCBLOCKs. */
416         for (i = 1; i < nr_tbs; i++) {
417                 if (!ldm_compare_tocblocks(tb[0], tb[i])) {
418                         ldm_crit("TOCBLOCKs 0 and %d do not match.", i);
419                         goto err;
420                 }
421         }
422         ldm_debug("Validated %d TOCBLOCKs successfully.", nr_tbs);
423         result = true;
424 err:
425         kfree(tb[1]);
426         return result;
427 }
428 
429 /**
430  * ldm_validate_vmdb - Read the VMDB and validate it
431  * @state: Partition check state including device holding the LDM Database
432  * @base:  Offset, into @bdev, of the database
433  * @ldb:   Cache of the database structures
434  *
435  * Find the vmdb of the LDM Database stored on @bdev and return the parsed
436  * information in @ldb.
437  *
438  * Return:  'true'   @ldb contains validated VBDB info
439  *          'false'  @ldb contents are undefined
440  */
441 static bool ldm_validate_vmdb(struct parsed_partitions *state,
442                               unsigned long base, struct ldmdb *ldb)
443 {
444         Sector sect;
445         u8 *data;
446         bool result = false;
447         struct vmdb *vm;
448         struct tocblock *toc;
449 
450         BUG_ON (!state || !ldb);
451 
452         vm  = &ldb->vm;
453         toc = &ldb->toc;
454 
455         data = read_part_sector(state, base + OFF_VMDB, &sect);
456         if (!data) {
457                 ldm_crit ("Disk read failed.");
458                 return false;
459         }
460 
461         if (!ldm_parse_vmdb (data, vm))
462                 goto out;                               /* Already logged */
463 
464         /* Are there uncommitted transactions? */
465         if (get_unaligned_be16(data + 0x10) != 0x01) {
466                 ldm_crit ("Database is not in a consistent state.  Aborting.");
467                 goto out;
468         }
469 
470         if (vm->vblk_offset != 512)
471                 ldm_info ("VBLKs start at offset 0x%04x.", vm->vblk_offset);
472 
473         /*
474          * The last_vblkd_seq can be before the end of the vmdb, just make sure
475          * it is not out of bounds.
476          */
477         if ((vm->vblk_size * vm->last_vblk_seq) > (toc->bitmap1_size << 9)) {
478                 ldm_crit ("VMDB exceeds allowed size specified by TOCBLOCK.  "
479                                 "Database is corrupt.  Aborting.");
480                 goto out;
481         }
482 
483         result = true;
484 out:
485         put_dev_sector (sect);
486         return result;
487 }
488 
489 
490 /**
491  * ldm_validate_partition_table - Determine whether bdev might be a dynamic disk
492  * @state: Partition check state including device holding the LDM Database
493  *
494  * This function provides a weak test to decide whether the device is a dynamic
495  * disk or not.  It looks for an MS-DOS-style partition table containing at
496  * least one partition of type 0x42 (formerly SFS, now used by Windows for
497  * dynamic disks).
498  *
499  * N.B.  The only possible error can come from the read_part_sector and that is
500  *       only likely to happen if the underlying device is strange.  If that IS
501  *       the case we should return zero to let someone else try.
502  *
503  * Return:  'true'   @state->bdev is a dynamic disk
504  *          'false'  @state->bdev is not a dynamic disk, or an error occurred
505  */
506 static bool ldm_validate_partition_table(struct parsed_partitions *state)
507 {
508         Sector sect;
509         u8 *data;
510         struct partition *p;
511         int i;
512         bool result = false;
513 
514         BUG_ON(!state);
515 
516         data = read_part_sector(state, 0, &sect);
517         if (!data) {
518                 ldm_info ("Disk read failed.");
519                 return false;
520         }
521 
522         if (*(__le16*) (data + 0x01FE) != cpu_to_le16 (MSDOS_LABEL_MAGIC))
523                 goto out;
524 
525         p = (struct partition*)(data + 0x01BE);
526         for (i = 0; i < 4; i++, p++)
527                 if (SYS_IND (p) == LDM_PARTITION) {
528                         result = true;
529                         break;
530                 }
531 
532         if (result)
533                 ldm_debug ("Found W2K dynamic disk partition type.");
534 
535 out:
536         put_dev_sector (sect);
537         return result;
538 }
539 
540 /**
541  * ldm_get_disk_objid - Search a linked list of vblk's for a given Disk Id
542  * @ldb:  Cache of the database structures
543  *
544  * The LDM Database contains a list of all partitions on all dynamic disks.
545  * The primary PRIVHEAD, at the beginning of the physical disk, tells us
546  * the GUID of this disk.  This function searches for the GUID in a linked
547  * list of vblk's.
548  *
549  * Return:  Pointer, A matching vblk was found
550  *          NULL,    No match, or an error
551  */
552 static struct vblk * ldm_get_disk_objid (const struct ldmdb *ldb)
553 {
554         struct list_head *item;
555 
556         BUG_ON (!ldb);
557 
558         list_for_each (item, &ldb->v_disk) {
559                 struct vblk *v = list_entry (item, struct vblk, list);
560                 if (!memcmp (v->vblk.disk.disk_id, ldb->ph.disk_id, GUID_SIZE))
561                         return v;
562         }
563 
564         return NULL;
565 }
566 
567 /**
568  * ldm_create_data_partitions - Create data partitions for this device
569  * @pp:   List of the partitions parsed so far
570  * @ldb:  Cache of the database structures
571  *
572  * The database contains ALL the partitions for ALL disk groups, so we need to
573  * filter out this specific disk. Using the disk's object id, we can find all
574  * the partitions in the database that belong to this disk.
575  *
576  * Add each partition in our database, to the parsed_partitions structure.
577  *
578  * N.B.  This function creates the partitions in the order it finds partition
579  *       objects in the linked list.
580  *
581  * Return:  'true'   Partition created
582  *          'false'  Error, probably a range checking problem
583  */
584 static bool ldm_create_data_partitions (struct parsed_partitions *pp,
585                                         const struct ldmdb *ldb)
586 {
587         struct list_head *item;
588         struct vblk *vb;
589         struct vblk *disk;
590         struct vblk_part *part;
591         int part_num = 1;
592 
593         BUG_ON (!pp || !ldb);
594 
595         disk = ldm_get_disk_objid (ldb);
596         if (!disk) {
597                 ldm_crit ("Can't find the ID of this disk in the database.");
598                 return false;
599         }
600 
601         strlcat(pp->pp_buf, " [LDM]", PAGE_SIZE);
602 
603         /* Create the data partitions */
604         list_for_each (item, &ldb->v_part) {
605                 vb = list_entry (item, struct vblk, list);
606                 part = &vb->vblk.part;
607 
608                 if (part->disk_id != disk->obj_id)
609                         continue;
610 
611                 put_partition (pp, part_num, ldb->ph.logical_disk_start +
612                                 part->start, part->size);
613                 part_num++;
614         }
615 
616         strlcat(pp->pp_buf, "\n", PAGE_SIZE);
617         return true;
618 }
619 
620 
621 /**
622  * ldm_relative - Calculate the next relative offset
623  * @buffer:  Block of data being worked on
624  * @buflen:  Size of the block of data
625  * @base:    Size of the previous fixed width fields
626  * @offset:  Cumulative size of the previous variable-width fields
627  *
628  * Because many of the VBLK fields are variable-width, it's necessary
629  * to calculate each offset based on the previous one and the length
630  * of the field it pointed to.
631  *
632  * Return:  -1 Error, the calculated offset exceeded the size of the buffer
633  *           n OK, a range-checked offset into buffer
634  */
635 static int ldm_relative(const u8 *buffer, int buflen, int base, int offset)
636 {
637 
638         base += offset;
639         if (!buffer || offset < 0 || base > buflen) {
640                 if (!buffer)
641                         ldm_error("!buffer");
642                 if (offset < 0)
643                         ldm_error("offset (%d) < 0", offset);
644                 if (base > buflen)
645                         ldm_error("base (%d) > buflen (%d)", base, buflen);
646                 return -1;
647         }
648         if (base + buffer[base] >= buflen) {
649                 ldm_error("base (%d) + buffer[base] (%d) >= buflen (%d)", base,
650                                 buffer[base], buflen);
651                 return -1;
652         }
653         return buffer[base] + offset + 1;
654 }
655 
656 /**
657  * ldm_get_vnum - Convert a variable-width, big endian number, into cpu order
658  * @block:  Pointer to the variable-width number to convert
659  *
660  * Large numbers in the LDM Database are often stored in a packed format.  Each
661  * number is prefixed by a one byte width marker.  All numbers in the database
662  * are stored in big-endian byte order.  This function reads one of these
663  * numbers and returns the result
664  *
665  * N.B.  This function DOES NOT perform any range checking, though the most
666  *       it will read is eight bytes.
667  *
668  * Return:  n A number
669  *          0 Zero, or an error occurred
670  */
671 static u64 ldm_get_vnum (const u8 *block)
672 {
673         u64 tmp = 0;
674         u8 length;
675 
676         BUG_ON (!block);
677 
678         length = *block++;
679 
680         if (length && length <= 8)
681                 while (length--)
682                         tmp = (tmp << 8) | *block++;
683         else
684                 ldm_error ("Illegal length %d.", length);
685 
686         return tmp;
687 }
688 
689 /**
690  * ldm_get_vstr - Read a length-prefixed string into a buffer
691  * @block:   Pointer to the length marker
692  * @buffer:  Location to copy string to
693  * @buflen:  Size of the output buffer
694  *
695  * Many of the strings in the LDM Database are not NULL terminated.  Instead
696  * they are prefixed by a one byte length marker.  This function copies one of
697  * these strings into a buffer.
698  *
699  * N.B.  This function DOES NOT perform any range checking on the input.
700  *       If the buffer is too small, the output will be truncated.
701  *
702  * Return:  0, Error and @buffer contents are undefined
703  *          n, String length in characters (excluding NULL)
704  *          buflen-1, String was truncated.
705  */
706 static int ldm_get_vstr (const u8 *block, u8 *buffer, int buflen)
707 {
708         int length;
709 
710         BUG_ON (!block || !buffer);
711 
712         length = block[0];
713         if (length >= buflen) {
714                 ldm_error ("Truncating string %d -> %d.", length, buflen);
715                 length = buflen - 1;
716         }
717         memcpy (buffer, block + 1, length);
718         buffer[length] = 0;
719         return length;
720 }
721 
722 
723 /**
724  * ldm_parse_cmp3 - Read a raw VBLK Component object into a vblk structure
725  * @buffer:  Block of data being worked on
726  * @buflen:  Size of the block of data
727  * @vb:      In-memory vblk in which to return information
728  *
729  * Read a raw VBLK Component object (version 3) into a vblk structure.
730  *
731  * Return:  'true'   @vb contains a Component VBLK
732  *          'false'  @vb contents are not defined
733  */
734 static bool ldm_parse_cmp3 (const u8 *buffer, int buflen, struct vblk *vb)
735 {
736         int r_objid, r_name, r_vstate, r_child, r_parent, r_stripe, r_cols, len;
737         struct vblk_comp *comp;
738 
739         BUG_ON (!buffer || !vb);
740 
741         r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
742         r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);
743         r_vstate = ldm_relative (buffer, buflen, 0x18, r_name);
744         r_child  = ldm_relative (buffer, buflen, 0x1D, r_vstate);
745         r_parent = ldm_relative (buffer, buflen, 0x2D, r_child);
746 
747         if (buffer[0x12] & VBLK_FLAG_COMP_STRIPE) {
748                 r_stripe = ldm_relative (buffer, buflen, 0x2E, r_parent);
749                 r_cols   = ldm_relative (buffer, buflen, 0x2E, r_stripe);
750                 len = r_cols;
751         } else {
752                 r_stripe = 0;
753                 r_cols   = 0;
754                 len = r_parent;
755         }
756         if (len < 0)
757                 return false;
758 
759         len += VBLK_SIZE_CMP3;
760         if (len != get_unaligned_be32(buffer + 0x14))
761                 return false;
762 
763         comp = &vb->vblk.comp;
764         ldm_get_vstr (buffer + 0x18 + r_name, comp->state,
765                 sizeof (comp->state));
766         comp->type      = buffer[0x18 + r_vstate];
767         comp->children  = ldm_get_vnum (buffer + 0x1D + r_vstate);
768         comp->parent_id = ldm_get_vnum (buffer + 0x2D + r_child);
769         comp->chunksize = r_stripe ? ldm_get_vnum (buffer+r_parent+0x2E) : 0;
770 
771         return true;
772 }
773 
774 /**
775  * ldm_parse_dgr3 - Read a raw VBLK Disk Group object into a vblk structure
776  * @buffer:  Block of data being worked on
777  * @buflen:  Size of the block of data
778  * @vb:      In-memory vblk in which to return information
779  *
780  * Read a raw VBLK Disk Group object (version 3) into a vblk structure.
781  *
782  * Return:  'true'   @vb contains a Disk Group VBLK
783  *          'false'  @vb contents are not defined
784  */
785 static int ldm_parse_dgr3 (const u8 *buffer, int buflen, struct vblk *vb)
786 {
787         int r_objid, r_name, r_diskid, r_id1, r_id2, len;
788         struct vblk_dgrp *dgrp;
789 
790         BUG_ON (!buffer || !vb);
791 
792         r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
793         r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);
794         r_diskid = ldm_relative (buffer, buflen, 0x18, r_name);
795 
796         if (buffer[0x12] & VBLK_FLAG_DGR3_IDS) {
797                 r_id1 = ldm_relative (buffer, buflen, 0x24, r_diskid);
798                 r_id2 = ldm_relative (buffer, buflen, 0x24, r_id1);
799                 len = r_id2;
800         } else {
801                 r_id1 = 0;
802                 r_id2 = 0;
803                 len = r_diskid;
804         }
805         if (len < 0)
806                 return false;
807 
808         len += VBLK_SIZE_DGR3;
809         if (len != get_unaligned_be32(buffer + 0x14))
810                 return false;
811 
812         dgrp = &vb->vblk.dgrp;
813         ldm_get_vstr (buffer + 0x18 + r_name, dgrp->disk_id,
814                 sizeof (dgrp->disk_id));
815         return true;
816 }
817 
818 /**
819  * ldm_parse_dgr4 - Read a raw VBLK Disk Group object into a vblk structure
820  * @buffer:  Block of data being worked on
821  * @buflen:  Size of the block of data
822  * @vb:      In-memory vblk in which to return information
823  *
824  * Read a raw VBLK Disk Group object (version 4) into a vblk structure.
825  *
826  * Return:  'true'   @vb contains a Disk Group VBLK
827  *          'false'  @vb contents are not defined
828  */
829 static bool ldm_parse_dgr4 (const u8 *buffer, int buflen, struct vblk *vb)
830 {
831         char buf[64];
832         int r_objid, r_name, r_id1, r_id2, len;
833         struct vblk_dgrp *dgrp;
834 
835         BUG_ON (!buffer || !vb);
836 
837         r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
838         r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);
839 
840         if (buffer[0x12] & VBLK_FLAG_DGR4_IDS) {
841                 r_id1 = ldm_relative (buffer, buflen, 0x44, r_name);
842                 r_id2 = ldm_relative (buffer, buflen, 0x44, r_id1);
843                 len = r_id2;
844         } else {
845                 r_id1 = 0;
846                 r_id2 = 0;
847                 len = r_name;
848         }
849         if (len < 0)
850                 return false;
851 
852         len += VBLK_SIZE_DGR4;
853         if (len != get_unaligned_be32(buffer + 0x14))
854                 return false;
855 
856         dgrp = &vb->vblk.dgrp;
857 
858         ldm_get_vstr (buffer + 0x18 + r_objid, buf, sizeof (buf));
859         return true;
860 }
861 
862 /**
863  * ldm_parse_dsk3 - Read a raw VBLK Disk object into a vblk structure
864  * @buffer:  Block of data being worked on
865  * @buflen:  Size of the block of data
866  * @vb:      In-memory vblk in which to return information
867  *
868  * Read a raw VBLK Disk object (version 3) into a vblk structure.
869  *
870  * Return:  'true'   @vb contains a Disk VBLK
871  *          'false'  @vb contents are not defined
872  */
873 static bool ldm_parse_dsk3 (const u8 *buffer, int buflen, struct vblk *vb)
874 {
875         int r_objid, r_name, r_diskid, r_altname, len;
876         struct vblk_disk *disk;
877 
878         BUG_ON (!buffer || !vb);
879 
880         r_objid   = ldm_relative (buffer, buflen, 0x18, 0);
881         r_name    = ldm_relative (buffer, buflen, 0x18, r_objid);
882         r_diskid  = ldm_relative (buffer, buflen, 0x18, r_name);
883         r_altname = ldm_relative (buffer, buflen, 0x18, r_diskid);
884         len = r_altname;
885         if (len < 0)
886                 return false;
887 
888         len += VBLK_SIZE_DSK3;
889         if (len != get_unaligned_be32(buffer + 0x14))
890                 return false;
891 
892         disk = &vb->vblk.disk;
893         ldm_get_vstr (buffer + 0x18 + r_diskid, disk->alt_name,
894                 sizeof (disk->alt_name));
895         if (uuid_be_to_bin(buffer + 0x19 + r_name, (uuid_be *)disk->disk_id))
896                 return false;
897 
898         return true;
899 }
900 
901 /**
902  * ldm_parse_dsk4 - Read a raw VBLK Disk object into a vblk structure
903  * @buffer:  Block of data being worked on
904  * @buflen:  Size of the block of data
905  * @vb:      In-memory vblk in which to return information
906  *
907  * Read a raw VBLK Disk object (version 4) into a vblk structure.
908  *
909  * Return:  'true'   @vb contains a Disk VBLK
910  *          'false'  @vb contents are not defined
911  */
912 static bool ldm_parse_dsk4 (const u8 *buffer, int buflen, struct vblk *vb)
913 {
914         int r_objid, r_name, len;
915         struct vblk_disk *disk;
916 
917         BUG_ON (!buffer || !vb);
918 
919         r_objid = ldm_relative (buffer, buflen, 0x18, 0);
920         r_name  = ldm_relative (buffer, buflen, 0x18, r_objid);
921         len     = r_name;
922         if (len < 0)
923                 return false;
924 
925         len += VBLK_SIZE_DSK4;
926         if (len != get_unaligned_be32(buffer + 0x14))
927                 return false;
928 
929         disk = &vb->vblk.disk;
930         memcpy (disk->disk_id, buffer + 0x18 + r_name, GUID_SIZE);
931         return true;
932 }
933 
934 /**
935  * ldm_parse_prt3 - Read a raw VBLK Partition object into a vblk structure
936  * @buffer:  Block of data being worked on
937  * @buflen:  Size of the block of data
938  * @vb:      In-memory vblk in which to return information
939  *
940  * Read a raw VBLK Partition object (version 3) into a vblk structure.
941  *
942  * Return:  'true'   @vb contains a Partition VBLK
943  *          'false'  @vb contents are not defined
944  */
945 static bool ldm_parse_prt3(const u8 *buffer, int buflen, struct vblk *vb)
946 {
947         int r_objid, r_name, r_size, r_parent, r_diskid, r_index, len;
948         struct vblk_part *part;
949 
950         BUG_ON(!buffer || !vb);
951         r_objid = ldm_relative(buffer, buflen, 0x18, 0);
952         if (r_objid < 0) {
953                 ldm_error("r_objid %d < 0", r_objid);
954                 return false;
955         }
956         r_name = ldm_relative(buffer, buflen, 0x18, r_objid);
957         if (r_name < 0) {
958                 ldm_error("r_name %d < 0", r_name);
959                 return false;
960         }
961         r_size = ldm_relative(buffer, buflen, 0x34, r_name);
962         if (r_size < 0) {
963                 ldm_error("r_size %d < 0", r_size);
964                 return false;
965         }
966         r_parent = ldm_relative(buffer, buflen, 0x34, r_size);
967         if (r_parent < 0) {
968                 ldm_error("r_parent %d < 0", r_parent);
969                 return false;
970         }
971         r_diskid = ldm_relative(buffer, buflen, 0x34, r_parent);
972         if (r_diskid < 0) {
973                 ldm_error("r_diskid %d < 0", r_diskid);
974                 return false;
975         }
976         if (buffer[0x12] & VBLK_FLAG_PART_INDEX) {
977                 r_index = ldm_relative(buffer, buflen, 0x34, r_diskid);
978                 if (r_index < 0) {
979                         ldm_error("r_index %d < 0", r_index);
980                         return false;
981                 }
982                 len = r_index;
983         } else {
984                 r_index = 0;
985                 len = r_diskid;
986         }
987         if (len < 0) {
988                 ldm_error("len %d < 0", len);
989                 return false;
990         }
991         len += VBLK_SIZE_PRT3;
992         if (len > get_unaligned_be32(buffer + 0x14)) {
993                 ldm_error("len %d > BE32(buffer + 0x14) %d", len,
994                                 get_unaligned_be32(buffer + 0x14));
995                 return false;
996         }
997         part = &vb->vblk.part;
998         part->start = get_unaligned_be64(buffer + 0x24 + r_name);
999         part->volume_offset = get_unaligned_be64(buffer + 0x2C + r_name);
1000         part->size = ldm_get_vnum(buffer + 0x34 + r_name);
1001         part->parent_id = ldm_get_vnum(buffer + 0x34 + r_size);
1002         part->disk_id = ldm_get_vnum(buffer + 0x34 + r_parent);
1003         if (vb->flags & VBLK_FLAG_PART_INDEX)
1004                 part->partnum = buffer[0x35 + r_diskid];
1005         else
1006                 part->partnum = 0;
1007         return true;
1008 }
1009 
1010 /**
1011  * ldm_parse_vol5 - Read a raw VBLK Volume object into a vblk structure
1012  * @buffer:  Block of data being worked on
1013  * @buflen:  Size of the block of data
1014  * @vb:      In-memory vblk in which to return information
1015  *
1016  * Read a raw VBLK Volume object (version 5) into a vblk structure.
1017  *
1018  * Return:  'true'   @vb contains a Volume VBLK
1019  *          'false'  @vb contents are not defined
1020  */
1021 static bool ldm_parse_vol5(const u8 *buffer, int buflen, struct vblk *vb)
1022 {
1023         int r_objid, r_name, r_vtype, r_disable_drive_letter, r_child, r_size;
1024         int r_id1, r_id2, r_size2, r_drive, len;
1025         struct vblk_volu *volu;
1026 
1027         BUG_ON(!buffer || !vb);
1028         r_objid = ldm_relative(buffer, buflen, 0x18, 0);
1029         if (r_objid < 0) {
1030                 ldm_error("r_objid %d < 0", r_objid);
1031                 return false;
1032         }
1033         r_name = ldm_relative(buffer, buflen, 0x18, r_objid);
1034         if (r_name < 0) {
1035                 ldm_error("r_name %d < 0", r_name);
1036                 return false;
1037         }
1038         r_vtype = ldm_relative(buffer, buflen, 0x18, r_name);
1039         if (r_vtype < 0) {
1040                 ldm_error("r_vtype %d < 0", r_vtype);
1041                 return false;
1042         }
1043         r_disable_drive_letter = ldm_relative(buffer, buflen, 0x18, r_vtype);
1044         if (r_disable_drive_letter < 0) {
1045                 ldm_error("r_disable_drive_letter %d < 0",
1046                                 r_disable_drive_letter);
1047                 return false;
1048         }
1049         r_child = ldm_relative(buffer, buflen, 0x2D, r_disable_drive_letter);
1050         if (r_child < 0) {
1051                 ldm_error("r_child %d < 0", r_child);
1052                 return false;
1053         }
1054         r_size = ldm_relative(buffer, buflen, 0x3D, r_child);
1055         if (r_size < 0) {
1056                 ldm_error("r_size %d < 0", r_size);
1057                 return false;
1058         }
1059         if (buffer[0x12] & VBLK_FLAG_VOLU_ID1) {
1060                 r_id1 = ldm_relative(buffer, buflen, 0x52, r_size);
1061                 if (r_id1 < 0) {
1062                         ldm_error("r_id1 %d < 0", r_id1);
1063                         return false;
1064                 }
1065         } else
1066                 r_id1 = r_size;
1067         if (buffer[0x12] & VBLK_FLAG_VOLU_ID2) {
1068                 r_id2 = ldm_relative(buffer, buflen, 0x52, r_id1);
1069                 if (r_id2 < 0) {
1070                         ldm_error("r_id2 %d < 0", r_id2);
1071                         return false;
1072                 }
1073         } else
1074                 r_id2 = r_id1;
1075         if (buffer[0x12] & VBLK_FLAG_VOLU_SIZE) {
1076                 r_size2 = ldm_relative(buffer, buflen, 0x52, r_id2);
1077                 if (r_size2 < 0) {
1078                         ldm_error("r_size2 %d < 0", r_size2);
1079                         return false;
1080                 }
1081         } else
1082                 r_size2 = r_id2;
1083         if (buffer[0x12] & VBLK_FLAG_VOLU_DRIVE) {
1084                 r_drive = ldm_relative(buffer, buflen, 0x52, r_size2);
1085                 if (r_drive < 0) {
1086                         ldm_error("r_drive %d < 0", r_drive);
1087                         return false;
1088                 }
1089         } else
1090                 r_drive = r_size2;
1091         len = r_drive;
1092         if (len < 0) {
1093                 ldm_error("len %d < 0", len);
1094                 return false;
1095         }
1096         len += VBLK_SIZE_VOL5;
1097         if (len > get_unaligned_be32(buffer + 0x14)) {
1098                 ldm_error("len %d > BE32(buffer + 0x14) %d", len,
1099                                 get_unaligned_be32(buffer + 0x14));
1100                 return false;
1101         }
1102         volu = &vb->vblk.volu;
1103         ldm_get_vstr(buffer + 0x18 + r_name, volu->volume_type,
1104                         sizeof(volu->volume_type));
1105         memcpy(volu->volume_state, buffer + 0x18 + r_disable_drive_letter,
1106                         sizeof(volu->volume_state));
1107         volu->size = ldm_get_vnum(buffer + 0x3D + r_child);
1108         volu->partition_type = buffer[0x41 + r_size];
1109         memcpy(volu->guid, buffer + 0x42 + r_size, sizeof(volu->guid));
1110         if (buffer[0x12] & VBLK_FLAG_VOLU_DRIVE) {
1111                 ldm_get_vstr(buffer + 0x52 + r_size, volu->drive_hint,
1112                                 sizeof(volu->drive_hint));
1113         }
1114         return true;
1115 }
1116 
1117 /**
1118  * ldm_parse_vblk - Read a raw VBLK object into a vblk structure
1119  * @buf:  Block of data being worked on
1120  * @len:  Size of the block of data
1121  * @vb:   In-memory vblk in which to return information
1122  *
1123  * Read a raw VBLK object into a vblk structure.  This function just reads the
1124  * information common to all VBLK types, then delegates the rest of the work to
1125  * helper functions: ldm_parse_*.
1126  *
1127  * Return:  'true'   @vb contains a VBLK
1128  *          'false'  @vb contents are not defined
1129  */
1130 static bool ldm_parse_vblk (const u8 *buf, int len, struct vblk *vb)
1131 {
1132         bool result = false;
1133         int r_objid;
1134 
1135         BUG_ON (!buf || !vb);
1136 
1137         r_objid = ldm_relative (buf, len, 0x18, 0);
1138         if (r_objid < 0) {
1139                 ldm_error ("VBLK header is corrupt.");
1140                 return false;
1141         }
1142 
1143         vb->flags  = buf[0x12];
1144         vb->type   = buf[0x13];
1145         vb->obj_id = ldm_get_vnum (buf + 0x18);
1146         ldm_get_vstr (buf+0x18+r_objid, vb->name, sizeof (vb->name));
1147 
1148         switch (vb->type) {
1149                 case VBLK_CMP3:  result = ldm_parse_cmp3 (buf, len, vb); break;
1150                 case VBLK_DSK3:  result = ldm_parse_dsk3 (buf, len, vb); break;
1151                 case VBLK_DSK4:  result = ldm_parse_dsk4 (buf, len, vb); break;
1152                 case VBLK_DGR3:  result = ldm_parse_dgr3 (buf, len, vb); break;
1153                 case VBLK_DGR4:  result = ldm_parse_dgr4 (buf, len, vb); break;
1154                 case VBLK_PRT3:  result = ldm_parse_prt3 (buf, len, vb); break;
1155                 case VBLK_VOL5:  result = ldm_parse_vol5 (buf, len, vb); break;
1156         }
1157 
1158         if (result)
1159                 ldm_debug ("Parsed VBLK 0x%llx (type: 0x%02x) ok.",
1160                          (unsigned long long) vb->obj_id, vb->type);
1161         else
1162                 ldm_error ("Failed to parse VBLK 0x%llx (type: 0x%02x).",
1163                         (unsigned long long) vb->obj_id, vb->type);
1164 
1165         return result;
1166 }
1167 
1168 
1169 /**
1170  * ldm_ldmdb_add - Adds a raw VBLK entry to the ldmdb database
1171  * @data:  Raw VBLK to add to the database
1172  * @len:   Size of the raw VBLK
1173  * @ldb:   Cache of the database structures
1174  *
1175  * The VBLKs are sorted into categories.  Partitions are also sorted by offset.
1176  *
1177  * N.B.  This function does not check the validity of the VBLKs.
1178  *
1179  * Return:  'true'   The VBLK was added
1180  *          'false'  An error occurred
1181  */
1182 static bool ldm_ldmdb_add (u8 *data, int len, struct ldmdb *ldb)
1183 {
1184         struct vblk *vb;
1185         struct list_head *item;
1186 
1187         BUG_ON (!data || !ldb);
1188 
1189         vb = kmalloc (sizeof (*vb), GFP_KERNEL);
1190         if (!vb) {
1191                 ldm_crit ("Out of memory.");
1192                 return false;
1193         }
1194 
1195         if (!ldm_parse_vblk (data, len, vb)) {
1196                 kfree(vb);
1197                 return false;                   /* Already logged */
1198         }
1199 
1200         /* Put vblk into the correct list. */
1201         switch (vb->type) {
1202         case VBLK_DGR3:
1203         case VBLK_DGR4:
1204                 list_add (&vb->list, &ldb->v_dgrp);
1205                 break;
1206         case VBLK_DSK3:
1207         case VBLK_DSK4:
1208                 list_add (&vb->list, &ldb->v_disk);
1209                 break;
1210         case VBLK_VOL5:
1211                 list_add (&vb->list, &ldb->v_volu);
1212                 break;
1213         case VBLK_CMP3:
1214                 list_add (&vb->list, &ldb->v_comp);
1215                 break;
1216         case VBLK_PRT3:
1217                 /* Sort by the partition's start sector. */
1218                 list_for_each (item, &ldb->v_part) {
1219                         struct vblk *v = list_entry (item, struct vblk, list);
1220                         if ((v->vblk.part.disk_id == vb->vblk.part.disk_id) &&
1221                             (v->vblk.part.start > vb->vblk.part.start)) {
1222                                 list_add_tail (&vb->list, &v->list);
1223                                 return true;
1224                         }
1225                 }
1226                 list_add_tail (&vb->list, &ldb->v_part);
1227                 break;
1228         }
1229         return true;
1230 }
1231 
1232 /**
1233  * ldm_frag_add - Add a VBLK fragment to a list
1234  * @data:   Raw fragment to be added to the list
1235  * @size:   Size of the raw fragment
1236  * @frags:  Linked list of VBLK fragments
1237  *
1238  * Fragmented VBLKs may not be consecutive in the database, so they are placed
1239  * in a list so they can be pieced together later.
1240  *
1241  * Return:  'true'   Success, the VBLK was added to the list
1242  *          'false'  Error, a problem occurred
1243  */
1244 static bool ldm_frag_add (const u8 *data, int size, struct list_head *frags)
1245 {
1246         struct frag *f;
1247         struct list_head *item;
1248         int rec, num, group;
1249 
1250         BUG_ON (!data || !frags);
1251 
1252         if (size < 2 * VBLK_SIZE_HEAD) {
1253                 ldm_error("Value of size is to small.");
1254                 return false;
1255         }
1256 
1257         group = get_unaligned_be32(data + 0x08);
1258         rec   = get_unaligned_be16(data + 0x0C);
1259         num   = get_unaligned_be16(data + 0x0E);
1260         if ((num < 1) || (num > 4)) {
1261                 ldm_error ("A VBLK claims to have %d parts.", num);
1262                 return false;
1263         }
1264         if (rec >= num) {
1265                 ldm_error("REC value (%d) exceeds NUM value (%d)", rec, num);
1266                 return false;
1267         }
1268 
1269         list_for_each (item, frags) {
1270                 f = list_entry (item, struct frag, list);
1271                 if (f->group == group)
1272                         goto found;
1273         }
1274 
1275         f = kmalloc (sizeof (*f) + size*num, GFP_KERNEL);
1276         if (!f) {
1277                 ldm_crit ("Out of memory.");
1278                 return false;
1279         }
1280 
1281         f->group = group;
1282         f->num   = num;
1283         f->rec   = rec;
1284         f->map   = 0xFF << num;
1285 
1286         list_add_tail (&f->list, frags);
1287 found:
1288         if (rec >= f->num) {
1289                 ldm_error("REC value (%d) exceeds NUM value (%d)", rec, f->num);
1290                 return false;
1291         }
1292         if (f->map & (1 << rec)) {
1293                 ldm_error ("Duplicate VBLK, part %d.", rec);
1294                 f->map &= 0x7F;                 /* Mark the group as broken */
1295                 return false;
1296         }
1297         f->map |= (1 << rec);
1298         if (!rec)
1299                 memcpy(f->data, data, VBLK_SIZE_HEAD);
1300         data += VBLK_SIZE_HEAD;
1301         size -= VBLK_SIZE_HEAD;
1302         memcpy(f->data + VBLK_SIZE_HEAD + rec * size, data, size);
1303         return true;
1304 }
1305 
1306 /**
1307  * ldm_frag_free - Free a linked list of VBLK fragments
1308  * @list:  Linked list of fragments
1309  *
1310  * Free a linked list of VBLK fragments
1311  *
1312  * Return:  none
1313  */
1314 static void ldm_frag_free (struct list_head *list)
1315 {
1316         struct list_head *item, *tmp;
1317 
1318         BUG_ON (!list);
1319 
1320         list_for_each_safe (item, tmp, list)
1321                 kfree (list_entry (item, struct frag, list));
1322 }
1323 
1324 /**
1325  * ldm_frag_commit - Validate fragmented VBLKs and add them to the database
1326  * @frags:  Linked list of VBLK fragments
1327  * @ldb:    Cache of the database structures
1328  *
1329  * Now that all the fragmented VBLKs have been collected, they must be added to
1330  * the database for later use.
1331  *
1332  * Return:  'true'   All the fragments we added successfully
1333  *          'false'  One or more of the fragments we invalid
1334  */
1335 static bool ldm_frag_commit (struct list_head *frags, struct ldmdb *ldb)
1336 {
1337         struct frag *f;
1338         struct list_head *item;
1339 
1340         BUG_ON (!frags || !ldb);
1341 
1342         list_for_each (item, frags) {
1343                 f = list_entry (item, struct frag, list);
1344 
1345                 if (f->map != 0xFF) {
1346                         ldm_error ("VBLK group %d is incomplete (0x%02x).",
1347                                 f->group, f->map);
1348                         return false;
1349                 }
1350 
1351                 if (!ldm_ldmdb_add (f->data, f->num*ldb->vm.vblk_size, ldb))
1352                         return false;           /* Already logged */
1353         }
1354         return true;
1355 }
1356 
1357 /**
1358  * ldm_get_vblks - Read the on-disk database of VBLKs into memory
1359  * @state: Partition check state including device holding the LDM Database
1360  * @base:  Offset, into @state->bdev, of the database
1361  * @ldb:   Cache of the database structures
1362  *
1363  * To use the information from the VBLKs, they need to be read from the disk,
1364  * unpacked and validated.  We cache them in @ldb according to their type.
1365  *
1366  * Return:  'true'   All the VBLKs were read successfully
1367  *          'false'  An error occurred
1368  */
1369 static bool ldm_get_vblks(struct parsed_partitions *state, unsigned long base,
1370                           struct ldmdb *ldb)
1371 {
1372         int size, perbuf, skip, finish, s, v, recs;
1373         u8 *data = NULL;
1374         Sector sect;
1375         bool result = false;
1376         LIST_HEAD (frags);
1377 
1378         BUG_ON(!state || !ldb);
1379 
1380         size   = ldb->vm.vblk_size;
1381         perbuf = 512 / size;
1382         skip   = ldb->vm.vblk_offset >> 9;              /* Bytes to sectors */
1383         finish = (size * ldb->vm.last_vblk_seq) >> 9;
1384 
1385         for (s = skip; s < finish; s++) {               /* For each sector */
1386                 data = read_part_sector(state, base + OFF_VMDB + s, &sect);
1387                 if (!data) {
1388                         ldm_crit ("Disk read failed.");
1389                         goto out;
1390                 }
1391 
1392                 for (v = 0; v < perbuf; v++, data+=size) {  /* For each vblk */
1393                         if (MAGIC_VBLK != get_unaligned_be32(data)) {
1394                                 ldm_error ("Expected to find a VBLK.");
1395                                 goto out;
1396                         }
1397 
1398                         recs = get_unaligned_be16(data + 0x0E); /* Number of records */
1399                         if (recs == 1) {
1400                                 if (!ldm_ldmdb_add (data, size, ldb))
1401                                         goto out;       /* Already logged */
1402                         } else if (recs > 1) {
1403                                 if (!ldm_frag_add (data, size, &frags))
1404                                         goto out;       /* Already logged */
1405                         }
1406                         /* else Record is not in use, ignore it. */
1407                 }
1408                 put_dev_sector (sect);
1409                 data = NULL;
1410         }
1411 
1412         result = ldm_frag_commit (&frags, ldb); /* Failures, already logged */
1413 out:
1414         if (data)
1415                 put_dev_sector (sect);
1416         ldm_frag_free (&frags);
1417 
1418         return result;
1419 }
1420 
1421 /**
1422  * ldm_free_vblks - Free a linked list of vblk's
1423  * @lh:  Head of a linked list of struct vblk
1424  *
1425  * Free a list of vblk's and free the memory used to maintain the list.
1426  *
1427  * Return:  none
1428  */
1429 static void ldm_free_vblks (struct list_head *lh)
1430 {
1431         struct list_head *item, *tmp;
1432 
1433         BUG_ON (!lh);
1434 
1435         list_for_each_safe (item, tmp, lh)
1436                 kfree (list_entry (item, struct vblk, list));
1437 }
1438 
1439 
1440 /**
1441  * ldm_partition - Find out whether a device is a dynamic disk and handle it
1442  * @state: Partition check state including device holding the LDM Database
1443  *
1444  * This determines whether the device @bdev is a dynamic disk and if so creates
1445  * the partitions necessary in the gendisk structure pointed to by @hd.
1446  *
1447  * We create a dummy device 1, which contains the LDM database, and then create
1448  * each partition described by the LDM database in sequence as devices 2+. For
1449  * example, if the device is hda, we would have: hda1: LDM database, hda2, hda3,
1450  * and so on: the actual data containing partitions.
1451  *
1452  * Return:  1 Success, @state->bdev is a dynamic disk and we handled it
1453  *          0 Success, @state->bdev is not a dynamic disk
1454  *         -1 An error occurred before enough information had been read
1455  *            Or @state->bdev is a dynamic disk, but it may be corrupted
1456  */
1457 int ldm_partition(struct parsed_partitions *state)
1458 {
1459         struct ldmdb  *ldb;
1460         unsigned long base;
1461         int result = -1;
1462 
1463         BUG_ON(!state);
1464 
1465         /* Look for signs of a Dynamic Disk */
1466         if (!ldm_validate_partition_table(state))
1467                 return 0;
1468 
1469         ldb = kmalloc (sizeof (*ldb), GFP_KERNEL);
1470         if (!ldb) {
1471                 ldm_crit ("Out of memory.");
1472                 goto out;
1473         }
1474 
1475         /* Parse and check privheads. */
1476         if (!ldm_validate_privheads(state, &ldb->ph))
1477                 goto out;               /* Already logged */
1478 
1479         /* All further references are relative to base (database start). */
1480         base = ldb->ph.config_start;
1481 
1482         /* Parse and check tocs and vmdb. */
1483         if (!ldm_validate_tocblocks(state, base, ldb) ||
1484             !ldm_validate_vmdb(state, base, ldb))
1485                 goto out;               /* Already logged */
1486 
1487         /* Initialize vblk lists in ldmdb struct */
1488         INIT_LIST_HEAD (&ldb->v_dgrp);
1489         INIT_LIST_HEAD (&ldb->v_disk);
1490         INIT_LIST_HEAD (&ldb->v_volu);
1491         INIT_LIST_HEAD (&ldb->v_comp);
1492         INIT_LIST_HEAD (&ldb->v_part);
1493 
1494         if (!ldm_get_vblks(state, base, ldb)) {
1495                 ldm_crit ("Failed to read the VBLKs from the database.");
1496                 goto cleanup;
1497         }
1498 
1499         /* Finally, create the data partition devices. */
1500         if (ldm_create_data_partitions(state, ldb)) {
1501                 ldm_debug ("Parsed LDM database successfully.");
1502                 result = 1;
1503         }
1504         /* else Already logged */
1505 
1506 cleanup:
1507         ldm_free_vblks (&ldb->v_dgrp);
1508         ldm_free_vblks (&ldb->v_disk);
1509         ldm_free_vblks (&ldb->v_volu);
1510         ldm_free_vblks (&ldb->v_comp);
1511         ldm_free_vblks (&ldb->v_part);
1512 out:
1513         kfree (ldb);
1514         return result;
1515 }
1516 

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