yaffs_yaffs2.c

   1 /*
   2  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
   3  *
   4  * Copyright (C) 2002-2010 Aleph One Ltd.
   5  *   for Toby Churchill Ltd and Brightstar Engineering
   6  *
   7  * Created by Charles Manning <charles@aleph1.co.uk>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14
  15 #include "yaffs_guts.h"
  16 #include "yaffs_trace.h"
  17 #include "yaffs_yaffs2.h"
  18 #include "yaffs_checkptrw.h"
  19 #include "yaffs_bitmap.h"
  20 #include "yaffs_qsort.h"
  21 #include "yaffs_nand.h"
  22 #include "yaffs_getblockinfo.h"
  23 #include "yaffs_verify.h"
  24
  25 /*
  26  * Checkpoints are really no benefit on very small partitions.
  27  *
  28  * To save space on small partitions don't bother with checkpoints unless
  29  * the partition is at least this big.
  30  */
  31 #define YAFFS_CHECKPOINT_MIN_BLOCKS 60
  32
  33 #define YAFFS_SMALL_HOLE_THRESHOLD 4
  34
  35
  36 /*
  37  * Oldest Dirty Sequence Number handling.
  38  */
  39
  40 /* yaffs2_CalcOldestDirtySequence()
  41  * yaffs2_FindOldestDirtySequence()
  42  * Calculate the oldest dirty sequence number if we don't know it.
  43  */
  44 void yaffs2_CalcOldestDirtySequence(yaffs_Device *dev)
  45 {
  46         int i;
  47         unsigned seq;
  48         unsigned blockNo = 0;
  49         yaffs_BlockInfo *b;
  50
  51         if(!dev->param.isYaffs2)
  52                 return;
  53
  54         /* Find the oldest dirty sequence number. */
  55         seq = dev->sequenceNumber + 1;
  56         b = dev->blockInfo;
  57         for (i = dev->internalStartBlock; i <= dev->internalEndBlock; i++) {
  58                 if (b->blockState == YAFFS_BLOCK_STATE_FULL &&
  59                         (b->pagesInUse - b->softDeletions) < dev->param.nChunksPerBlock &&
  60                         b->sequenceNumber < seq) {
  61                         seq = b->sequenceNumber;
  62                         blockNo = i;
  63                 }
  64                 b++;
  65         }
  66
  67         if(blockNo){
  68                 dev->oldestDirtySequence = seq;
  69                 dev->oldestDirtyBlock = blockNo;
  70         }
  71
  72 }
  73
  74
  75 void yaffs2_FindOldestDirtySequence(yaffs_Device *dev)
  76 {
  77         if(!dev->param.isYaffs2)
  78                 return;
  79
  80         if(!dev->oldestDirtySequence)
  81                 yaffs2_CalcOldestDirtySequence(dev);
  82 }
  83
  84 /*
  85  * yaffs_ClearOldestDirtySequence()
  86  * Called when a block is erased or marked bad. (ie. when its sequenceNumber
  87  * becomes invalid). If the value matches the oldest then we clear
  88  * dev->oldestDirtySequence to force its recomputation.
  89  */
  90 void yaffs2_ClearOldestDirtySequence(yaffs_Device *dev, yaffs_BlockInfo *bi)
  91 {
  92
  93         if(!dev->param.isYaffs2)
  94                 return;
  95
  96         if(!bi || bi->sequenceNumber == dev->oldestDirtySequence){
  97                 dev->oldestDirtySequence = 0;
  98                 dev->oldestDirtyBlock = 0;
  99         }
 100 }
 101
 102 /*
 103  * yaffs2_UpdateOldestDirtySequence()
 104  * Update the oldest dirty sequence number whenever we dirty a block.
 105  * Only do this if the oldestDirtySequence is actually being tracked.
 106  */
 107 void yaffs2_UpdateOldestDirtySequence(yaffs_Device *dev, unsigned blockNo, yaffs_BlockInfo *bi)
 108 {
 109         if(!dev->param.isYaffs2)
 110                 return;
 111
 112         if(dev->oldestDirtySequence){
 113                 if(dev->oldestDirtySequence > bi->sequenceNumber){
 114                         dev->oldestDirtySequence = bi->sequenceNumber;
 115                         dev->oldestDirtyBlock = blockNo;
 116                 }
 117         }
 118 }
 119
 120 int yaffs2_BlockNotDisqualifiedFromGC(yaffs_Device *dev,
 121                                         yaffs_BlockInfo *bi)
 122 {
 123
 124         if (!dev->param.isYaffs2)
 125                 return 1;       /* disqualification only applies to yaffs2. */
 126
 127         if (!bi->hasShrinkHeader)
 128                 return 1;       /* can gc */
 129
 130         yaffs2_FindOldestDirtySequence(dev);
 131
 132         /* Can't do gc of this block if there are any blocks older than this one that have
 133          * discarded pages.
 134          */
 135         return (bi->sequenceNumber <= dev->oldestDirtySequence);
 136 }
 137
 138 /*
 139  * yaffs2_FindRefreshBlock()
 140  * periodically finds the oldest full block by sequence number for refreshing.
 141  * Only for yaffs2.
 142  */
 143 __u32 yaffs2_FindRefreshBlock(yaffs_Device *dev)
 144 {
 145         __u32 b ;
 146
 147         __u32 oldest = 0;
 148         __u32 oldestSequence = 0;
 149
 150         yaffs_BlockInfo *bi;
 151
 152         if(!dev->param.isYaffs2)
 153                 return oldest;
 154
 155         /*
 156          * If refresh period < 10 then refreshing is disabled.
 157          */
 158         if(dev->param.refreshPeriod < 10)
 159                 return oldest;
 160
 161         /*
 162          * Fix broken values.
 163          */
 164         if(dev->refreshSkip > dev->param.refreshPeriod)
 165                 dev->refreshSkip = dev->param.refreshPeriod;
 166
 167         if(dev->refreshSkip > 0)
 168                 return oldest;
 169
 170         /*
 171          * Refresh skip is now zero.
 172          * We'll do a refresh this time around....
 173          * Update the refresh skip and find the oldest block.
 174          */
 175         dev->refreshSkip = dev->param.refreshPeriod;
 176         dev->refreshCount++;
 177         bi = dev->blockInfo;
 178         for (b = dev->internalStartBlock; b <=dev->internalEndBlock; b++){
 179
 180                 if (bi->blockState == YAFFS_BLOCK_STATE_FULL){
 181
 182                         if(oldest < 1 ||
 183                                 bi->sequenceNumber < oldestSequence){
 184                                 oldest = b;
 185                                 oldestSequence = bi->sequenceNumber;
 186                         }
 187                 }
 188                 bi++;
 189         }
 190
 191         if (oldest > 0) {
 192                 T(YAFFS_TRACE_GC,
 193                   (TSTR("GC refresh count %d selected block %d with sequenceNumber %d" TENDSTR),
 194                    dev->refreshCount, oldest, oldestSequence));
 195         }
 196
 197         return oldest;
 198 }
 199
 200 int yaffs2_CheckpointRequired(yaffs_Device *dev)
 201 {
 202         int nblocks;
 203
 204         if(!dev->param.isYaffs2)
 205                 return 0;
 206
 207         nblocks = dev->internalEndBlock - dev->internalStartBlock + 1 ;
 208
 209         return  !dev->param.skipCheckpointWrite &&
 210                 !dev->readOnly &&
 211                 (nblocks >= YAFFS_CHECKPOINT_MIN_BLOCKS);
 212 }
 213
 214 int yaffs2_CalcCheckpointBlocksRequired(yaffs_Device *dev)
 215 {
 216         int retval;
 217
 218         if(!dev->param.isYaffs2)
 219                 return 0;
 220
 221         if (!dev->nCheckpointBlocksRequired &&
 222                 yaffs2_CheckpointRequired(dev)){
 223                 /* Not a valid value so recalculate */
 224                 int nBytes = 0;
 225                 int nBlocks;
 226                 int devBlocks = (dev->param.endBlock - dev->param.startBlock + 1);
 227
 228                 nBytes += sizeof(yaffs_CheckpointValidity);
 229                 nBytes += sizeof(yaffs_CheckpointDevice);
 230                 nBytes += devBlocks * sizeof(yaffs_BlockInfo);
 231                 nBytes += devBlocks * dev->chunkBitmapStride;
 232                 nBytes += (sizeof(yaffs_CheckpointObject) + sizeof(__u32)) * (dev->nObjects);
 233                 nBytes += (dev->tnodeSize + sizeof(__u32)) * (dev->nTnodes);
 234                 nBytes += sizeof(yaffs_CheckpointValidity);
 235                 nBytes += sizeof(__u32); /* checksum*/
 236
 237                 /* Round up and add 2 blocks to allow for some bad blocks, so add 3 */
 238
 239                 nBlocks = (nBytes/(dev->nDataBytesPerChunk * dev->param.nChunksPerBlock)) + 3;
 240
 241                 dev->nCheckpointBlocksRequired = nBlocks;
 242         }
 243
 244         retval = dev->nCheckpointBlocksRequired - dev->blocksInCheckpoint;
 245         if(retval < 0)
 246                 retval = 0;
 247         return retval;
 248 }
 249
 250 /*--------------------- Checkpointing --------------------*/
 251
 252
 253 static int yaffs2_WriteCheckpointValidityMarker(yaffs_Device *dev, int head)
 254 {
 255         yaffs_CheckpointValidity cp;
 256
 257         memset(&cp, 0, sizeof(cp));
 258
 259         cp.structType = sizeof(cp);
 260         cp.magic = YAFFS_MAGIC;
 261         cp.version = YAFFS_CHECKPOINT_VERSION;
 262         cp.head = (head) ? 1 : 0;
 263
 264         return (yaffs2_CheckpointWrite(dev, &cp, sizeof(cp)) == sizeof(cp)) ?
 265                 1 : 0;
 266 }
 267
 268 static int yaffs2_ReadCheckpointValidityMarker(yaffs_Device *dev, int head)
 269 {
 270         yaffs_CheckpointValidity cp;
 271         int ok;
 272
 273         ok = (yaffs2_CheckpointRead(dev, &cp, sizeof(cp)) == sizeof(cp));
 274
 275         if (ok)
 276                 ok = (cp.structType == sizeof(cp)) &&
 277                      (cp.magic == YAFFS_MAGIC) &&
 278                      (cp.version == YAFFS_CHECKPOINT_VERSION) &&
 279                      (cp.head == ((head) ? 1 : 0));
 280         return ok ? 1 : 0;
 281 }
 282
 283 static void yaffs2_DeviceToCheckpointDevice(yaffs_CheckpointDevice *cp,
 284                                            yaffs_Device *dev)
 285 {
 286         cp->nErasedBlocks = dev->nErasedBlocks;
 287         cp->allocationBlock = dev->allocationBlock;
 288         cp->allocationPage = dev->allocationPage;
 289         cp->nFreeChunks = dev->nFreeChunks;
 290
 291         cp->nDeletedFiles = dev->nDeletedFiles;
 292         cp->nUnlinkedFiles = dev->nUnlinkedFiles;
 293         cp->nBackgroundDeletions = dev->nBackgroundDeletions;
 294         cp->sequenceNumber = dev->sequenceNumber;
 295
 296 }
 297
 298 static void yaffs2_CheckpointDeviceToDevice(yaffs_Device *dev,
 299                                            yaffs_CheckpointDevice *cp)
 300 {
 301         dev->nErasedBlocks = cp->nErasedBlocks;
 302         dev->allocationBlock = cp->allocationBlock;
 303         dev->allocationPage = cp->allocationPage;
 304         dev->nFreeChunks = cp->nFreeChunks;
 305
 306         dev->nDeletedFiles = cp->nDeletedFiles;
 307         dev->nUnlinkedFiles = cp->nUnlinkedFiles;
 308         dev->nBackgroundDeletions = cp->nBackgroundDeletions;
 309         dev->sequenceNumber = cp->sequenceNumber;
 310 }
 311
 312
 313 static int yaffs2_WriteCheckpointDevice(yaffs_Device *dev)
 314 {
 315         yaffs_CheckpointDevice cp;
 316         __u32 nBytes;
 317         __u32 nBlocks = (dev->internalEndBlock - dev->internalStartBlock + 1);
 318
 319         int ok;
 320
 321         /* Write device runtime values*/
 322         yaffs2_DeviceToCheckpointDevice(&cp, dev);
 323         cp.structType = sizeof(cp);
 324
 325         ok = (yaffs2_CheckpointWrite(dev, &cp, sizeof(cp)) == sizeof(cp));
 326
 327         /* Write block info */
 328         if (ok) {
 329                 nBytes = nBlocks * sizeof(yaffs_BlockInfo);
 330                 ok = (yaffs2_CheckpointWrite(dev, dev->blockInfo, nBytes) == nBytes);
 331         }
 332
 333         /* Write chunk bits */
 334         if (ok) {
 335                 nBytes = nBlocks * dev->chunkBitmapStride;
 336                 ok = (yaffs2_CheckpointWrite(dev, dev->chunkBits, nBytes) == nBytes);
 337         }
 338         return   ok ? 1 : 0;
 339
 340 }
 341
 342 static int yaffs2_ReadCheckpointDevice(yaffs_Device *dev)
 343 {
 344         yaffs_CheckpointDevice cp;
 345         __u32 nBytes;
 346         __u32 nBlocks = (dev->internalEndBlock - dev->internalStartBlock + 1);
 347
 348         int ok;
 349
 350         ok = (yaffs2_CheckpointRead(dev, &cp, sizeof(cp)) == sizeof(cp));
 351         if (!ok)
 352                 return 0;
 353
 354         if (cp.structType != sizeof(cp))
 355                 return 0;
 356
 357
 358         yaffs2_CheckpointDeviceToDevice(dev, &cp);
 359
 360         nBytes = nBlocks * sizeof(yaffs_BlockInfo);
 361
 362         ok = (yaffs2_CheckpointRead(dev, dev->blockInfo, nBytes) == nBytes);
 363
 364         if (!ok)
 365                 return 0;
 366         nBytes = nBlocks * dev->chunkBitmapStride;
 367
 368         ok = (yaffs2_CheckpointRead(dev, dev->chunkBits, nBytes) == nBytes);
 369
 370         return ok ? 1 : 0;
 371 }
 372
 373 static void yaffs2_ObjectToCheckpointObject(yaffs_CheckpointObject *cp,
 374                                            yaffs_Object *obj)
 375 {
 376
 377         cp->objectId = obj->objectId;
 378         cp->parentId = (obj->parent) ? obj->parent->objectId : 0;
 379         cp->hdrChunk = obj->hdrChunk;
 380         cp->variantType = obj->variantType;
 381         cp->deleted = obj->deleted;
 382         cp->softDeleted = obj->softDeleted;
 383         cp->unlinked = obj->unlinked;
 384         cp->fake = obj->fake;
 385         cp->renameAllowed = obj->renameAllowed;
 386         cp->unlinkAllowed = obj->unlinkAllowed;
 387         cp->serial = obj->serial;
 388         cp->nDataChunks = obj->nDataChunks;
 389
 390         if (obj->variantType == YAFFS_OBJECT_TYPE_FILE)
 391                 cp->fileSizeOrEquivalentObjectId = obj->variant.fileVariant.fileSize;
 392         else if (obj->variantType == YAFFS_OBJECT_TYPE_HARDLINK)
 393                 cp->fileSizeOrEquivalentObjectId = obj->variant.hardLinkVariant.equivalentObjectId;
 394 }
 395
 396 static int yaffs2_CheckpointObjectToObject(yaffs_Object *obj, yaffs_CheckpointObject *cp)
 397 {
 398
 399         yaffs_Object *parent;
 400
 401         if (obj->variantType != cp->variantType) {
 402                 T(YAFFS_TRACE_ERROR, (TSTR("Checkpoint read object %d type %d "
 403                         TCONT("chunk %d does not match existing object type %d")
 404                         TENDSTR), cp->objectId, cp->variantType, cp->hdrChunk,
 405                         obj->variantType));
 406                 return 0;
 407         }
 408
 409         obj->objectId = cp->objectId;
 410
 411         if (cp->parentId)
 412                 parent = yaffs_FindOrCreateObjectByNumber(
 413                                         obj->myDev,
 414                                         cp->parentId,
 415                                         YAFFS_OBJECT_TYPE_DIRECTORY);
 416         else
 417                 parent = NULL;
 418
 419         if (parent) {
 420                 if (parent->variantType != YAFFS_OBJECT_TYPE_DIRECTORY) {
 421                         T(YAFFS_TRACE_ALWAYS, (TSTR("Checkpoint read object %d parent %d type %d"
 422                                 TCONT(" chunk %d Parent type, %d, not directory")
 423                                 TENDSTR),
 424                                 cp->objectId, cp->parentId, cp->variantType,
 425                                 cp->hdrChunk, parent->variantType));
 426                         return 0;
 427                 }
 428                 yaffs_AddObjectToDirectory(parent, obj);
 429         }
 430
 431         obj->hdrChunk = cp->hdrChunk;
 432         obj->variantType = cp->variantType;
 433         obj->deleted = cp->deleted;
 434         obj->softDeleted = cp->softDeleted;
 435         obj->unlinked = cp->unlinked;
 436         obj->fake = cp->fake;
 437         obj->renameAllowed = cp->renameAllowed;
 438         obj->unlinkAllowed = cp->unlinkAllowed;
 439         obj->serial = cp->serial;
 440         obj->nDataChunks = cp->nDataChunks;
 441
 442         if (obj->variantType == YAFFS_OBJECT_TYPE_FILE)
 443                 obj->variant.fileVariant.fileSize = cp->fileSizeOrEquivalentObjectId;
 444         else if (obj->variantType == YAFFS_OBJECT_TYPE_HARDLINK)
 445                 obj->variant.hardLinkVariant.equivalentObjectId = cp->fileSizeOrEquivalentObjectId;
 446
 447         if (obj->hdrChunk > 0)
 448                 obj->lazyLoaded = 1;
 449         return 1;
 450 }
 451
 452
 453
 454 static int yaffs2_CheckpointTnodeWorker(yaffs_Object *in, yaffs_Tnode *tn,
 455                                         __u32 level, int chunkOffset)
 456 {
 457         int i;
 458         yaffs_Device *dev = in->myDev;
 459         int ok = 1;
 460
 461         if (tn) {
 462                 if (level > 0) {
 463
 464                         for (i = 0; i < YAFFS_NTNODES_INTERNAL && ok; i++) {
 465                                 if (tn->internal[i]) {
 466                                         ok = yaffs2_CheckpointTnodeWorker(in,
 467                                                         tn->internal[i],
 468                                                         level - 1,
 469                                                         (chunkOffset<<YAFFS_TNODES_INTERNAL_BITS) + i);
 470                                 }
 471                         }
 472                 } else if (level == 0) {
 473                         __u32 baseOffset = chunkOffset <<  YAFFS_TNODES_LEVEL0_BITS;
 474                         ok = (yaffs2_CheckpointWrite(dev, &baseOffset, sizeof(baseOffset)) == sizeof(baseOffset));
 475                         if (ok)
 476                                 ok = (yaffs2_CheckpointWrite(dev, tn, dev->tnodeSize) == dev->tnodeSize);
 477                 }
 478         }
 479
 480         return ok;
 481
 482 }
 483
 484 static int yaffs2_WriteCheckpointTnodes(yaffs_Object *obj)
 485 {
 486         __u32 endMarker = ~0;
 487         int ok = 1;
 488
 489         if (obj->variantType == YAFFS_OBJECT_TYPE_FILE) {
 490                 ok = yaffs2_CheckpointTnodeWorker(obj,
 491                                             obj->variant.fileVariant.top,
 492                                             obj->variant.fileVariant.topLevel,
 493                                             0);
 494                 if (ok)
 495                         ok = (yaffs2_CheckpointWrite(obj->myDev, &endMarker, sizeof(endMarker)) ==
 496                                 sizeof(endMarker));
 497         }
 498
 499         return ok ? 1 : 0;
 500 }
 501
 502 static int yaffs2_ReadCheckpointTnodes(yaffs_Object *obj)
 503 {
 504         __u32 baseChunk;
 505         int ok = 1;
 506         yaffs_Device *dev = obj->myDev;
 507         yaffs_FileStructure *fileStructPtr = &obj->variant.fileVariant;
 508         yaffs_Tnode *tn;
 509         int nread = 0;
 510
 511         ok = (yaffs2_CheckpointRead(dev, &baseChunk, sizeof(baseChunk)) == sizeof(baseChunk));
 512
 513         while (ok && (~baseChunk)) {
 514                 nread++;
 515                 /* Read level 0 tnode */
 516
 517
 518                 tn = yaffs_GetTnode(dev);
 519                 if (tn){
 520                         ok = (yaffs2_CheckpointRead(dev, tn, dev->tnodeSize) == dev->tnodeSize);
 521                 } else
 522                         ok = 0;
 523
 524                 if (tn && ok)
 525                         ok = yaffs_AddOrFindLevel0Tnode(dev,
 526                                                         fileStructPtr,
 527                                                         baseChunk,
 528                                                         tn) ? 1 : 0;
 529
 530                 if (ok)
 531                         ok = (yaffs2_CheckpointRead(dev, &baseChunk, sizeof(baseChunk)) == sizeof(baseChunk));
 532
 533         }
 534
 535         T(YAFFS_TRACE_CHECKPOINT, (
 536                 TSTR("Checkpoint read tnodes %d records, last %d. ok %d" TENDSTR),
 537                 nread, baseChunk, ok));
 538
 539         return ok ? 1 : 0;
 540 }
 541
 542
 543 static int yaffs2_WriteCheckpointObjects(yaffs_Device *dev)
 544 {
 545         yaffs_Object *obj;
 546         yaffs_CheckpointObject cp;
 547         int i;
 548         int ok = 1;
 549         struct ylist_head *lh;
 550
 551
 552         /* Iterate through the objects in each hash entry,
 553          * dumping them to the checkpointing stream.
 554          */
 555
 556         for (i = 0; ok &&  i <  YAFFS_NOBJECT_BUCKETS; i++) {
 557                 ylist_for_each(lh, &dev->objectBucket[i].list) {
 558                         if (lh) {
 559                                 obj = ylist_entry(lh, yaffs_Object, hashLink);
 560                                 if (!obj->deferedFree) {
 561                                         yaffs2_ObjectToCheckpointObject(&cp, obj);
 562                                         cp.structType = sizeof(cp);
 563
 564                                         T(YAFFS_TRACE_CHECKPOINT, (
 565                                                 TSTR("Checkpoint write object %d parent %d type %d chunk %d obj addr %p" TENDSTR),
 566                                                 cp.objectId, cp.parentId, cp.variantType, cp.hdrChunk, obj));
 567
 568                                         ok = (yaffs2_CheckpointWrite(dev, &cp, sizeof(cp)) == sizeof(cp));
 569
 570                                         if (ok && obj->variantType == YAFFS_OBJECT_TYPE_FILE)
 571                                                 ok = yaffs2_WriteCheckpointTnodes(obj);
 572                                 }
 573                         }
 574                 }
 575         }
 576
 577         /* Dump end of list */
 578         memset(&cp, 0xFF, sizeof(yaffs_CheckpointObject));
 579         cp.structType = sizeof(cp);
 580
 581         if (ok)
 582                 ok = (yaffs2_CheckpointWrite(dev, &cp, sizeof(cp)) == sizeof(cp));
 583
 584         return ok ? 1 : 0;
 585 }
 586
 587 static int yaffs2_ReadCheckpointObjects(yaffs_Device *dev)
 588 {
 589         yaffs_Object *obj;
 590         yaffs_CheckpointObject cp;
 591         int ok = 1;
 592         int done = 0;
 593         yaffs_Object *hardList = NULL;
 594
 595         while (ok && !done) {
 596                 ok = (yaffs2_CheckpointRead(dev, &cp, sizeof(cp)) == sizeof(cp));
 597                 if (cp.structType != sizeof(cp)) {
 598                         T(YAFFS_TRACE_CHECKPOINT, (TSTR("struct size %d instead of %d ok %d"TENDSTR),
 599                                 cp.structType, (int)sizeof(cp), ok));
 600                         ok = 0;
 601                 }
 602
 603                 T(YAFFS_TRACE_CHECKPOINT, (TSTR("Checkpoint read object %d parent %d type %d chunk %d " TENDSTR),
 604                         cp.objectId, cp.parentId, cp.variantType, cp.hdrChunk));
 605
 606                 if (ok && cp.objectId == ~0)
 607                         done = 1;
 608                 else if (ok) {
 609                         obj = yaffs_FindOrCreateObjectByNumber(dev, cp.objectId, cp.variantType);
 610                         if (obj) {
 611                                 ok = yaffs2_CheckpointObjectToObject(obj, &cp);
 612                                 if (!ok)
 613                                         break;
 614                                 if (obj->variantType == YAFFS_OBJECT_TYPE_FILE) {
 615                                         ok = yaffs2_ReadCheckpointTnodes(obj);
 616                                 } else if (obj->variantType == YAFFS_OBJECT_TYPE_HARDLINK) {
 617                                         obj->hardLinks.next =
 618                                                 (struct ylist_head *) hardList;
 619                                         hardList = obj;
 620                                 }
 621                         } else
 622                                 ok = 0;
 623                 }
 624         }
 625
 626         if (ok)
 627                 yaffs_HardlinkFixup(dev, hardList);
 628
 629         return ok ? 1 : 0;
 630 }
 631
 632 static int yaffs2_WriteCheckpointSum(yaffs_Device *dev)
 633 {
 634         __u32 checkpointSum;
 635         int ok;
 636
 637         yaffs2_GetCheckpointSum(dev, &checkpointSum);
 638
 639         ok = (yaffs2_CheckpointWrite(dev, &checkpointSum, sizeof(checkpointSum)) == sizeof(checkpointSum));
 640
 641         if (!ok)
 642                 return 0;
 643
 644         return 1;
 645 }
 646
 647 static int yaffs2_ReadCheckpointSum(yaffs_Device *dev)
 648 {
 649         __u32 checkpointSum0;
 650         __u32 checkpointSum1;
 651         int ok;
 652
 653         yaffs2_GetCheckpointSum(dev, &checkpointSum0);
 654
 655         ok = (yaffs2_CheckpointRead(dev, &checkpointSum1, sizeof(checkpointSum1)) == sizeof(checkpointSum1));
 656
 657         if (!ok)
 658                 return 0;
 659
 660         if (checkpointSum0 != checkpointSum1)
 661                 return 0;
 662
 663         return 1;
 664 }
 665
 666
 667 static int yaffs2_WriteCheckpointData(yaffs_Device *dev)
 668 {
 669         int ok = 1;
 670
 671         if (!yaffs2_CheckpointRequired(dev)) {
 672                 T(YAFFS_TRACE_CHECKPOINT, (TSTR("skipping checkpoint write" TENDSTR)));
 673                 ok = 0;
 674         }
 675
 676         if (ok)
 677                 ok = yaffs2_CheckpointOpen(dev, 1);
 678
 679         if (ok) {
 680                 T(YAFFS_TRACE_CHECKPOINT, (TSTR("write checkpoint validity" TENDSTR)));
 681                 ok = yaffs2_WriteCheckpointValidityMarker(dev, 1);
 682         }
 683         if (ok) {
 684                 T(YAFFS_TRACE_CHECKPOINT, (TSTR("write checkpoint device" TENDSTR)));
 685                 ok = yaffs2_WriteCheckpointDevice(dev);
 686         }
 687         if (ok) {
 688                 T(YAFFS_TRACE_CHECKPOINT, (TSTR("write checkpoint objects" TENDSTR)));
 689                 ok = yaffs2_WriteCheckpointObjects(dev);
 690         }
 691         if (ok) {
 692                 T(YAFFS_TRACE_CHECKPOINT, (TSTR("write checkpoint validity" TENDSTR)));
 693                 ok = yaffs2_WriteCheckpointValidityMarker(dev, 0);
 694         }
 695
 696         if (ok)
 697                 ok = yaffs2_WriteCheckpointSum(dev);
 698
 699         if (!yaffs2_CheckpointClose(dev))
 700                 ok = 0;
 701
 702         if (ok)
 703                 dev->isCheckpointed = 1;
 704         else
 705                 dev->isCheckpointed = 0;
 706
 707         return dev->isCheckpointed;
 708 }
 709
 710 static int yaffs2_ReadCheckpointData(yaffs_Device *dev)
 711 {
 712         int ok = 1;
 713
 714         if(!dev->param.isYaffs2)
 715                 ok = 0;
 716
 717         if (ok && dev->param.skipCheckpointRead) {
 718                 T(YAFFS_TRACE_CHECKPOINT, (TSTR("skipping checkpoint read" TENDSTR)));
 719                 ok = 0;
 720         }
 721
 722         if (ok)
 723                 ok = yaffs2_CheckpointOpen(dev, 0); /* open for read */
 724
 725         if (ok) {
 726                 T(YAFFS_TRACE_CHECKPOINT, (TSTR("read checkpoint validity" TENDSTR)));
 727                 ok = yaffs2_ReadCheckpointValidityMarker(dev, 1);
 728         }
 729         if (ok) {
 730                 T(YAFFS_TRACE_CHECKPOINT, (TSTR("read checkpoint device" TENDSTR)));
 731                 ok = yaffs2_ReadCheckpointDevice(dev);
 732         }
 733         if (ok) {
 734                 T(YAFFS_TRACE_CHECKPOINT, (TSTR("read checkpoint objects" TENDSTR)));
 735                 ok = yaffs2_ReadCheckpointObjects(dev);
 736         }
 737         if (ok) {
 738                 T(YAFFS_TRACE_CHECKPOINT, (TSTR("read checkpoint validity" TENDSTR)));
 739                 ok = yaffs2_ReadCheckpointValidityMarker(dev, 0);
 740         }
 741
 742         if (ok) {
 743                 ok = yaffs2_ReadCheckpointSum(dev);
 744                 T(YAFFS_TRACE_CHECKPOINT, (TSTR("read checkpoint checksum %d" TENDSTR), ok));
 745         }
 746
 747         if (!yaffs2_CheckpointClose(dev))
 748                 ok = 0;
 749
 750         if (ok)
 751                 dev->isCheckpointed = 1;
 752         else
 753                 dev->isCheckpointed = 0;
 754
 755         return ok ? 1 : 0;
 756
 757 }
 758
 759 void yaffs2_InvalidateCheckpoint(yaffs_Device *dev)
 760 {
 761         if (dev->isCheckpointed ||
 762                         dev->blocksInCheckpoint > 0) {
 763                 dev->isCheckpointed = 0;
 764                 yaffs2_CheckpointInvalidateStream(dev);
 765         }
 766         if (dev->param.markSuperBlockDirty)
 767                 dev->param.markSuperBlockDirty(dev);
 768 }
 769
 770
 771 int yaffs_CheckpointSave(yaffs_Device *dev)
 772 {
 773
 774         T(YAFFS_TRACE_CHECKPOINT, (TSTR("save entry: isCheckpointed %d"TENDSTR), dev->isCheckpointed));
 775
 776         yaffs_VerifyObjects(dev);
 777         yaffs_VerifyBlocks(dev);
 778         yaffs_VerifyFreeChunks(dev);
 779
 780         if (!dev->isCheckpointed) {
 781                 yaffs2_InvalidateCheckpoint(dev);
 782                 yaffs2_WriteCheckpointData(dev);
 783         }
 784
 785         T(YAFFS_TRACE_ALWAYS, (TSTR("save exit: isCheckpointed %d"TENDSTR), dev->isCheckpointed));
 786
 787         return dev->isCheckpointed;
 788 }
 789
 790 int yaffs2_CheckpointRestore(yaffs_Device *dev)
 791 {
 792         int retval;
 793         T(YAFFS_TRACE_CHECKPOINT, (TSTR("restore entry: isCheckpointed %d"TENDSTR), dev->isCheckpointed));
 794
 795         retval = yaffs2_ReadCheckpointData(dev);
 796
 797         if (dev->isCheckpointed) {
 798                 yaffs_VerifyObjects(dev);
 799                 yaffs_VerifyBlocks(dev);
 800                 yaffs_VerifyFreeChunks(dev);
 801         }
 802
 803         T(YAFFS_TRACE_CHECKPOINT, (TSTR("restore exit: isCheckpointed %d"TENDSTR), dev->isCheckpointed));
 804
 805         return retval;
 806 }
 807
 808 int yaffs2_HandleHole(yaffs_Object *obj, loff_t newSize)
 809 {
 810         /* if newsSize > oldFileSize.
 811          * We're going to be writing a hole.
 812          * If the hole is small then write zeros otherwise write a start of hole marker.
 813          */
 814
 815
 816         loff_t oldFileSize;
 817         int increase;
 818         int smallHole   ;
 819         int result = YAFFS_OK;
 820         yaffs_Device *dev = NULL;
 821
 822         __u8 *localBuffer = NULL;
 823
 824         int smallIncreaseOk = 0;
 825
 826         if(!obj)
 827                 return YAFFS_FAIL;
 828
 829         if(obj->variantType != YAFFS_OBJECT_TYPE_FILE)
 830                 return YAFFS_FAIL;
 831
 832         dev = obj->myDev;
 833
 834         /* Bail out if not yaffs2 mode */
 835         if(!dev->param.isYaffs2)
 836                 return YAFFS_OK;
 837
 838         oldFileSize = obj->variant.fileVariant.fileSize;
 839
 840         if (newSize <= oldFileSize)
 841                 return YAFFS_OK;
 842
 843         increase = newSize - oldFileSize;
 844
 845         if(increase < YAFFS_SMALL_HOLE_THRESHOLD * dev->nDataBytesPerChunk &&
 846                 yaffs_CheckSpaceForAllocation(dev, YAFFS_SMALL_HOLE_THRESHOLD + 1))
 847                 smallHole = 1;
 848         else
 849                 smallHole = 0;
 850
 851         if(smallHole)
 852                 localBuffer= yaffs_GetTempBuffer(dev, __LINE__);
 853
 854         if(localBuffer){
 855                 /* fill hole with zero bytes */
 856                 int pos = oldFileSize;
 857                 int thisWrite;
 858                 int written;
 859                 memset(localBuffer,0,dev->nDataBytesPerChunk);
 860                 smallIncreaseOk = 1;
 861
 862                 while(increase > 0 && smallIncreaseOk){
 863                         thisWrite = increase;
 864                         if(thisWrite > dev->nDataBytesPerChunk)
 865                                 thisWrite = dev->nDataBytesPerChunk;
 866                         written = yaffs_DoWriteDataToFile(obj,localBuffer,pos,thisWrite,0);
 867                         if(written == thisWrite){
 868                                 pos += thisWrite;
 869                                 increase -= thisWrite;
 870                         } else
 871                                 smallIncreaseOk = 0;
 872                 }
 873
 874                 yaffs_ReleaseTempBuffer(dev,localBuffer,__LINE__);
 875
 876                 /* If we were out of space then reverse any chunks we've added */
 877                 if(!smallIncreaseOk)
 878                         yaffs_ResizeDown(obj, oldFileSize);
 879         }
 880
 881         if (!smallIncreaseOk &&
 882                 obj->parent &&
 883                 obj->parent->objectId != YAFFS_OBJECTID_UNLINKED &&
 884                 obj->parent->objectId != YAFFS_OBJECTID_DELETED){
 885                 /* Write a hole start header with the old file size */
 886                 yaffs_UpdateObjectHeader(obj, NULL, 0, 1, 0, NULL);
 887         }
 888
 889         return result;
 890
 891 }
 892
 893
 894 typedef struct {
 895         int seq;
 896         int block;
 897 } yaffs_BlockIndex;
 898
 899
 900 static int yaffs2_ybicmp(const void *a, const void *b)
 901 {
 902         register int aseq = ((yaffs_BlockIndex *)a)->seq;
 903         register int bseq = ((yaffs_BlockIndex *)b)->seq;
 904         register int ablock = ((yaffs_BlockIndex *)a)->block;
 905         register int bblock = ((yaffs_BlockIndex *)b)->block;
 906         if (aseq == bseq)
 907                 return ablock - bblock;
 908         else
 909                 return aseq - bseq;
 910 }
 911
 912 int yaffs2_ScanBackwards(yaffs_Device *dev)
 913 {
 914         yaffs_ExtendedTags tags;
 915         int blk;
 916         int blockIterator;
 917         int startIterator;
 918         int endIterator;
 919         int nBlocksToScan = 0;
 920
 921         int chunk;
 922         int result;
 923         int c;
 924         int deleted;
 925         yaffs_BlockState state;
 926         yaffs_Object *hardList = NULL;
 927         yaffs_BlockInfo *bi;
 928         __u32 sequenceNumber;
 929         yaffs_ObjectHeader *oh;
 930         yaffs_Object *in;
 931         yaffs_Object *parent;
 932         int nBlocks = dev->internalEndBlock - dev->internalStartBlock + 1;
 933         int itsUnlinked;
 934         __u8 *chunkData;
 935
 936         int fileSize;
 937         int isShrink;
 938         int foundChunksInBlock;
 939         int equivalentObjectId;
 940         int alloc_failed = 0;
 941
 942
 943         yaffs_BlockIndex *blockIndex = NULL;
 944         int altBlockIndex = 0;
 945
 946         T(YAFFS_TRACE_SCAN,
 947           (TSTR
 948            ("yaffs2_ScanBackwards starts  intstartblk %d intendblk %d..."
 949             TENDSTR), dev->internalStartBlock, dev->internalEndBlock));
 950
 951
 952         dev->sequenceNumber = YAFFS_LOWEST_SEQUENCE_NUMBER;
 953
 954         blockIndex = YMALLOC(nBlocks * sizeof(yaffs_BlockIndex));
 955
 956         if (!blockIndex) {
 957                 blockIndex = YMALLOC_ALT(nBlocks * sizeof(yaffs_BlockIndex));
 958                 altBlockIndex = 1;
 959         }
 960
 961         if (!blockIndex) {
 962                 T(YAFFS_TRACE_SCAN,
 963                   (TSTR("yaffs2_ScanBackwards() could not allocate block index!" TENDSTR)));
 964                 return YAFFS_FAIL;
 965         }
 966
 967         dev->blocksInCheckpoint = 0;
 968
 969         chunkData = yaffs_GetTempBuffer(dev, __LINE__);
 970
 971         /* Scan all the blocks to determine their state */
 972         bi = dev->blockInfo;
 973         for (blk = dev->internalStartBlock; blk <= dev->internalEndBlock; blk++) {
 974                 yaffs_ClearChunkBits(dev, blk);
 975                 bi->pagesInUse = 0;
 976                 bi->softDeletions = 0;
 977
 978                 yaffs_QueryInitialBlockState(dev, blk, &state, &sequenceNumber);
 979
 980                 bi->blockState = state;
 981                 bi->sequenceNumber = sequenceNumber;
 982
 983                 if (bi->sequenceNumber == YAFFS_SEQUENCE_CHECKPOINT_DATA)
 984                         bi->blockState = state = YAFFS_BLOCK_STATE_CHECKPOINT;
 985                 if (bi->sequenceNumber == YAFFS_SEQUENCE_BAD_BLOCK)
 986                         bi->blockState = state = YAFFS_BLOCK_STATE_DEAD;
 987
 988                 T(YAFFS_TRACE_SCAN_DEBUG,
 989                   (TSTR("Block scanning block %d state %d seq %d" TENDSTR), blk,
 990                    state, sequenceNumber));
 991
 992
 993                 if (state == YAFFS_BLOCK_STATE_CHECKPOINT) {
 994                         dev->blocksInCheckpoint++;
 995
 996                 } else if (state == YAFFS_BLOCK_STATE_DEAD) {
 997                         T(YAFFS_TRACE_BAD_BLOCKS,
 998                           (TSTR("block %d is bad" TENDSTR), blk));
 999                 } else if (state == YAFFS_BLOCK_STATE_EMPTY) {
1000                         T(YAFFS_TRACE_SCAN_DEBUG,
1001                           (TSTR("Block empty " TENDSTR)));
1002                         dev->nErasedBlocks++;
1003                         dev->nFreeChunks += dev->param.nChunksPerBlock;
1004                 } else if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
1005
1006                         /* Determine the highest sequence number */
1007                         if (sequenceNumber >= YAFFS_LOWEST_SEQUENCE_NUMBER &&
1008                             sequenceNumber < YAFFS_HIGHEST_SEQUENCE_NUMBER) {
1009
1010                                 blockIndex[nBlocksToScan].seq = sequenceNumber;
1011                                 blockIndex[nBlocksToScan].block = blk;
1012
1013                                 nBlocksToScan++;
1014
1015                                 if (sequenceNumber >= dev->sequenceNumber)
1016                                         dev->sequenceNumber = sequenceNumber;
1017                         } else {
1018                                 /* TODO: Nasty sequence number! */
1019                                 T(YAFFS_TRACE_SCAN,
1020                                   (TSTR
1021                                    ("Block scanning block %d has bad sequence number %d"
1022                                     TENDSTR), blk, sequenceNumber));
1023
1024                         }
1025                 }
1026                 bi++;
1027         }
1028
1029         T(YAFFS_TRACE_SCAN,
1030         (TSTR("%d blocks to be sorted..." TENDSTR), nBlocksToScan));
1031
1032
1033
1034         YYIELD();
1035
1036         /* Sort the blocks by sequence number*/
1037         yaffs_qsort(blockIndex, nBlocksToScan, sizeof(yaffs_BlockIndex), yaffs2_ybicmp);
1038
1039         YYIELD();
1040
1041         T(YAFFS_TRACE_SCAN, (TSTR("...done" TENDSTR)));
1042
1043         /* Now scan the blocks looking at the data. */
1044         startIterator = 0;
1045         endIterator = nBlocksToScan - 1;
1046         T(YAFFS_TRACE_SCAN_DEBUG,
1047           (TSTR("%d blocks to be scanned" TENDSTR), nBlocksToScan));
1048
1049         /* For each block.... backwards */
1050         for (blockIterator = endIterator; !alloc_failed && blockIterator >= startIterator;
1051                         blockIterator--) {
1052                 /* Cooperative multitasking! This loop can run for so
1053                    long that watchdog timers expire. */
1054                 YYIELD();
1055
1056                 /* get the block to scan in the correct order */
1057                 blk = blockIndex[blockIterator].block;
1058
1059                 bi = yaffs_GetBlockInfo(dev, blk);
1060
1061
1062                 state = bi->blockState;
1063
1064                 deleted = 0;
1065
1066                 /* For each chunk in each block that needs scanning.... */
1067                 foundChunksInBlock = 0;
1068                 for (c = dev->param.nChunksPerBlock - 1;
1069                      !alloc_failed && c >= 0 &&
1070                      (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING ||
1071                       state == YAFFS_BLOCK_STATE_ALLOCATING); c--) {
1072                         /* Scan backwards...
1073                          * Read the tags and decide what to do
1074                          */
1075
1076                         chunk = blk * dev->param.nChunksPerBlock + c;
1077
1078                         result = yaffs_ReadChunkWithTagsFromNAND(dev, chunk, NULL,
1079                                                         &tags);
1080
1081                         /* Let's have a good look at this chunk... */
1082
1083                         if (!tags.chunkUsed) {
1084                                 /* An unassigned chunk in the block.
1085                                  * If there are used chunks after this one, then
1086                                  * it is a chunk that was skipped due to failing the erased
1087                                  * check. Just skip it so that it can be deleted.
1088                                  * But, more typically, We get here when this is an unallocated
1089                                  * chunk and his means that either the block is empty or
1090                                  * this is the one being allocated from
1091                                  */
1092
1093                                 if (foundChunksInBlock) {
1094                                         /* This is a chunk that was skipped due to failing the erased check */
1095                                 } else if (c == 0) {
1096                                         /* We're looking at the first chunk in the block so the block is unused */
1097                                         state = YAFFS_BLOCK_STATE_EMPTY;
1098                                         dev->nErasedBlocks++;
1099                                 } else {
1100                                         if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING ||
1101                                             state == YAFFS_BLOCK_STATE_ALLOCATING) {
1102                                                 if (dev->sequenceNumber == bi->sequenceNumber) {
1103                                                         /* this is the block being allocated from */
1104
1105                                                         T(YAFFS_TRACE_SCAN,
1106                                                           (TSTR
1107                                                            (" Allocating from %d %d"
1108                                                             TENDSTR), blk, c));
1109
1110                                                         state = YAFFS_BLOCK_STATE_ALLOCATING;
1111                                                         dev->allocationBlock = blk;
1112                                                         dev->allocationPage = c;
1113                                                         dev->allocationBlockFinder = blk;
1114                                                 } else {
1115                                                         /* This is a partially written block that is not
1116                                                          * the current allocation block.
1117                                                          */
1118
1119                                                          T(YAFFS_TRACE_SCAN,
1120                                                          (TSTR("Partially written block %d detected" TENDSTR),
1121                                                          blk));
1122                                                 }
1123                                         }
1124                                 }
1125
1126                                 dev->nFreeChunks++;
1127
1128                         } else if (tags.eccResult == YAFFS_ECC_RESULT_UNFIXED) {
1129                                 T(YAFFS_TRACE_SCAN,
1130                                   (TSTR(" Unfixed ECC in chunk(%d:%d), chunk ignored"TENDSTR),
1131                                   blk, c));
1132
1133                                   dev->nFreeChunks++;
1134
1135                         } else if (tags.objectId > YAFFS_MAX_OBJECT_ID ||
1136                                 tags.chunkId > YAFFS_MAX_CHUNK_ID ||
1137                                 (tags.chunkId > 0 && tags.byteCount > dev->nDataBytesPerChunk) ||
1138                                 tags.sequenceNumber != bi->sequenceNumber ) {
1139                                 T(YAFFS_TRACE_SCAN,
1140                                   (TSTR("Chunk (%d:%d) with bad tags:obj = %d, chunkId = %d, byteCount = %d, ignored"TENDSTR),
1141                                   blk, c,tags.objectId, tags.chunkId, tags.byteCount));
1142
1143                                   dev->nFreeChunks++;
1144
1145                         } else if (tags.chunkId > 0) {
1146                                 /* chunkId > 0 so it is a data chunk... */
1147                                 unsigned int endpos;
1148                                 __u32 chunkBase =
1149                                     (tags.chunkId - 1) * dev->nDataBytesPerChunk;
1150
1151                                 foundChunksInBlock = 1;
1152
1153
1154                                 yaffs_SetChunkBit(dev, blk, c);
1155                                 bi->pagesInUse++;
1156
1157                                 in = yaffs_FindOrCreateObjectByNumber(dev,
1158                                                                       tags.
1159                                                                       objectId,
1160                                                                       YAFFS_OBJECT_TYPE_FILE);
1161                                 if (!in) {
1162                                         /* Out of memory */
1163                                         alloc_failed = 1;
1164                                 }
1165
1166                                 if (in &&
1167                                     in->variantType == YAFFS_OBJECT_TYPE_FILE
1168                                     && chunkBase < in->variant.fileVariant.shrinkSize) {
1169                                         /* This has not been invalidated by a resize */
1170                                         if (!yaffs_PutChunkIntoFile(in, tags.chunkId, chunk, -1)) {
1171                                                 alloc_failed = 1;
1172                                         }
1173
1174                                         /* File size is calculated by looking at the data chunks if we have not
1175                                          * seen an object header yet. Stop this practice once we find an object header.
1176                                          */
1177                                         endpos = chunkBase + tags.byteCount;
1178
1179                                         if (!in->valid &&       /* have not got an object header yet */
1180                                             in->variant.fileVariant.scannedFileSize < endpos) {
1181                                                 in->variant.fileVariant.scannedFileSize = endpos;
1182                                                 in->variant.fileVariant.fileSize = endpos;
1183                                         }
1184
1185                                 } else if (in) {
1186                                         /* This chunk has been invalidated by a resize, or a past file deletion
1187                                          * so delete the chunk*/
1188                                         yaffs_DeleteChunk(dev, chunk, 1, __LINE__);
1189
1190                                 }
1191                         } else {
1192                                 /* chunkId == 0, so it is an ObjectHeader.
1193                                  * Thus, we read in the object header and make the object
1194                                  */
1195                                 foundChunksInBlock = 1;
1196
1197                                 yaffs_SetChunkBit(dev, blk, c);
1198                                 bi->pagesInUse++;
1199
1200                                 oh = NULL;
1201                                 in = NULL;
1202
1203                                 if (tags.extraHeaderInfoAvailable) {
1204                                         in = yaffs_FindOrCreateObjectByNumber(dev,
1205                                                 tags.objectId,
1206                                                 tags.extraObjectType);
1207                                         if (!in)
1208                                                 alloc_failed = 1;
1209                                 }
1210
1211                                 if (!in ||
1212                                     (!in->valid && dev->param.disableLazyLoad) ||
1213                                     tags.extraShadows ||
1214                                     (!in->valid &&
1215                                     (tags.objectId == YAFFS_OBJECTID_ROOT ||
1216                                      tags.objectId == YAFFS_OBJECTID_LOSTNFOUND))) {
1217
1218                                         /* If we don't have  valid info then we need to read the chunk
1219                                          * TODO In future we can probably defer reading the chunk and
1220                                          * living with invalid data until needed.
1221                                          */
1222
1223                                         result = yaffs_ReadChunkWithTagsFromNAND(dev,
1224                                                                         chunk,
1225                                                                         chunkData,
1226                                                                         NULL);
1227
1228                                         oh = (yaffs_ObjectHeader *) chunkData;
1229
1230                                         if (dev->param.inbandTags) {
1231                                                 /* Fix up the header if they got corrupted by inband tags */
1232                                                 oh->shadowsObject = oh->inbandShadowsObject;
1233                                                 oh->isShrink = oh->inbandIsShrink;
1234                                         }
1235
1236                                         if (!in) {
1237                                                 in = yaffs_FindOrCreateObjectByNumber(dev, tags.objectId, oh->type);
1238                                                 if (!in)
1239                                                         alloc_failed = 1;
1240                                         }
1241
1242                                 }
1243
1244                                 if (!in) {
1245                                         /* TODO Hoosterman we have a problem! */
1246                                         T(YAFFS_TRACE_ERROR,
1247                                           (TSTR
1248                                            ("yaffs tragedy: Could not make object for object  %d at chunk %d during scan"
1249                                             TENDSTR), tags.objectId, chunk));
1250                                         continue;
1251                                 }
1252
1253                                 if (in->valid) {
1254                                         /* We have already filled this one.
1255                                          * We have a duplicate that will be discarded, but
1256                                          * we first have to suck out resize info if it is a file.
1257                                          */
1258
1259                                         if ((in->variantType == YAFFS_OBJECT_TYPE_FILE) &&
1260                                              ((oh &&
1261                                                oh->type == YAFFS_OBJECT_TYPE_FILE) ||
1262                                               (tags.extraHeaderInfoAvailable  &&
1263                                                tags.extraObjectType == YAFFS_OBJECT_TYPE_FILE))) {
1264                                                 __u32 thisSize =
1265                                                     (oh) ? oh->fileSize : tags.
1266                                                     extraFileLength;
1267                                                 __u32 parentObjectId =
1268                                                     (oh) ? oh->
1269                                                     parentObjectId : tags.
1270                                                     extraParentObjectId;
1271
1272
1273                                                 isShrink =
1274                                                     (oh) ? oh->isShrink : tags.
1275                                                     extraIsShrinkHeader;
1276
1277                                                 /* If it is deleted (unlinked at start also means deleted)
1278                                                  * we treat the file size as being zeroed at this point.
1279                                                  */
1280                                                 if (parentObjectId ==
1281                                                     YAFFS_OBJECTID_DELETED
1282                                                     || parentObjectId ==
1283                                                     YAFFS_OBJECTID_UNLINKED) {
1284                                                         thisSize = 0;
1285                                                         isShrink = 1;
1286                                                 }
1287
1288                                                 if (isShrink && in->variant.fileVariant.shrinkSize > thisSize)
1289                                                         in->variant.fileVariant.shrinkSize = thisSize;
1290
1291                                                 if (isShrink)
1292                                                         bi->hasShrinkHeader = 1;
1293
1294                                         }
1295                                         /* Use existing - destroy this one. */
1296                                         yaffs_DeleteChunk(dev, chunk, 1, __LINE__);
1297
1298                                 }
1299
1300                                 if (!in->valid && in->variantType !=
1301                                     (oh ? oh->type : tags.extraObjectType))
1302                                         T(YAFFS_TRACE_ERROR, (
1303                                                 TSTR("yaffs tragedy: Bad object type, "
1304                                             TCONT("%d != %d, for object %d at chunk ")
1305                                             TCONT("%d during scan")
1306                                                 TENDSTR), oh ?
1307                                             oh->type : tags.extraObjectType,
1308                                             in->variantType, tags.objectId,
1309                                             chunk));
1310
1311                                 if (!in->valid &&
1312                                     (tags.objectId == YAFFS_OBJECTID_ROOT ||
1313                                      tags.objectId ==
1314                                      YAFFS_OBJECTID_LOSTNFOUND)) {
1315                                         /* We only load some info, don't fiddle with directory structure */
1316                                         in->valid = 1;
1317
1318                                         if (oh) {
1319
1320                                                 in->yst_mode = oh->yst_mode;
1321 #ifdef CONFIG_YAFFS_WINCE
1322                                                 in->win_atime[0] = oh->win_atime[0];
1323                                                 in->win_ctime[0] = oh->win_ctime[0];
1324                                                 in->win_mtime[0] = oh->win_mtime[0];
1325                                                 in->win_atime[1] = oh->win_atime[1];
1326                                                 in->win_ctime[1] = oh->win_ctime[1];
1327                                                 in->win_mtime[1] = oh->win_mtime[1];
1328 #else
1329                                                 in->yst_uid = oh->yst_uid;
1330                                                 in->yst_gid = oh->yst_gid;
1331                                                 in->yst_atime = oh->yst_atime;
1332                                                 in->yst_mtime = oh->yst_mtime;
1333                                                 in->yst_ctime = oh->yst_ctime;
1334                                                 in->yst_rdev = oh->yst_rdev;
1335
1336                                                 in->lazyLoaded = 0;
1337
1338 #endif
1339                                         } else
1340                                                 in->lazyLoaded = 1;
1341
1342                                         in->hdrChunk = chunk;
1343
1344                                 } else if (!in->valid) {
1345                                         /* we need to load this info */
1346
1347                                         in->valid = 1;
1348                                         in->hdrChunk = chunk;
1349
1350                                         if (oh) {
1351                                                 in->variantType = oh->type;
1352
1353                                                 in->yst_mode = oh->yst_mode;
1354 #ifdef CONFIG_YAFFS_WINCE
1355                                                 in->win_atime[0] = oh->win_atime[0];
1356                                                 in->win_ctime[0] = oh->win_ctime[0];
1357                                                 in->win_mtime[0] = oh->win_mtime[0];
1358                                                 in->win_atime[1] = oh->win_atime[1];
1359                                                 in->win_ctime[1] = oh->win_ctime[1];
1360                                                 in->win_mtime[1] = oh->win_mtime[1];
1361 #else
1362                                                 in->yst_uid = oh->yst_uid;
1363                                                 in->yst_gid = oh->yst_gid;
1364                                                 in->yst_atime = oh->yst_atime;
1365                                                 in->yst_mtime = oh->yst_mtime;
1366                                                 in->yst_ctime = oh->yst_ctime;
1367                                                 in->yst_rdev = oh->yst_rdev;
1368 #endif
1369
1370                                                 if (oh->shadowsObject > 0)
1371                                                         yaffs_HandleShadowedObject(dev,
1372                                                                            oh->
1373                                                                            shadowsObject,
1374                                                                            1);
1375
1376
1377
1378                                                 yaffs_SetObjectNameFromOH(in, oh);
1379                                                 parent =
1380                                                     yaffs_FindOrCreateObjectByNumber
1381                                                         (dev, oh->parentObjectId,
1382                                                          YAFFS_OBJECT_TYPE_DIRECTORY);
1383
1384                                                  fileSize = oh->fileSize;
1385                                                  isShrink = oh->isShrink;
1386                                                  equivalentObjectId = oh->equivalentObjectId;
1387
1388                                         } else {
1389                                                 in->variantType = tags.extraObjectType;
1390                                                 parent =
1391                                                     yaffs_FindOrCreateObjectByNumber
1392                                                         (dev, tags.extraParentObjectId,
1393                                                          YAFFS_OBJECT_TYPE_DIRECTORY);
1394                                                  fileSize = tags.extraFileLength;
1395                                                  isShrink = tags.extraIsShrinkHeader;
1396                                                  equivalentObjectId = tags.extraEquivalentObjectId;
1397                                                 in->lazyLoaded = 1;
1398
1399                                         }
1400                                         in->dirty = 0;
1401
1402                                         if (!parent)
1403                                                 alloc_failed = 1;
1404
1405                                         /* directory stuff...
1406                                          * hook up to parent
1407                                          */
1408
1409                                         if (parent && parent->variantType ==
1410                                             YAFFS_OBJECT_TYPE_UNKNOWN) {
1411                                                 /* Set up as a directory */
1412                                                 parent->variantType =
1413                                                         YAFFS_OBJECT_TYPE_DIRECTORY;
1414                                                 YINIT_LIST_HEAD(&parent->variant.
1415                                                         directoryVariant.
1416                                                         children);
1417                                         } else if (!parent || parent->variantType !=
1418                                                    YAFFS_OBJECT_TYPE_DIRECTORY) {
1419                                                 /* Hoosterman, another problem....
1420                                                  * We're trying to use a non-directory as a directory
1421                                                  */
1422
1423                                                 T(YAFFS_TRACE_ERROR,
1424                                                   (TSTR
1425                                                    ("yaffs tragedy: attempting to use non-directory as a directory in scan. Put in lost+found."
1426                                                     TENDSTR)));
1427                                                 parent = dev->lostNFoundDir;
1428                                         }
1429
1430                                         yaffs_AddObjectToDirectory(parent, in);
1431
1432                                         itsUnlinked = (parent == dev->deletedDir) ||
1433                                                       (parent == dev->unlinkedDir);
1434
1435                                         if (isShrink) {
1436                                                 /* Mark the block as having a shrinkHeader */
1437                                                 bi->hasShrinkHeader = 1;
1438                                         }
1439
1440                                         /* Note re hardlinks.
1441                                          * Since we might scan a hardlink before its equivalent object is scanned
1442                                          * we put them all in a list.
1443                                          * After scanning is complete, we should have all the objects, so we run
1444                                          * through this list and fix up all the chains.
1445                                          */
1446
1447                                         switch (in->variantType) {
1448                                         case YAFFS_OBJECT_TYPE_UNKNOWN:
1449                                                 /* Todo got a problem */
1450                                                 break;
1451                                         case YAFFS_OBJECT_TYPE_FILE:
1452
1453                                                 if (in->variant.fileVariant.
1454                                                     scannedFileSize < fileSize) {
1455                                                         /* This covers the case where the file size is greater
1456                                                          * than where the data is
1457                                                          * This will happen if the file is resized to be larger
1458                                                          * than its current data extents.
1459                                                          */
1460                                                         in->variant.fileVariant.fileSize = fileSize;
1461                                                         in->variant.fileVariant.scannedFileSize = fileSize;
1462                                                 }
1463
1464                                                 if (in->variant.fileVariant.shrinkSize > fileSize)
1465                                                         in->variant.fileVariant.shrinkSize = fileSize;
1466
1467
1468                                                 break;
1469                                         case YAFFS_OBJECT_TYPE_HARDLINK:
1470                                                 if (!itsUnlinked) {
1471                                                         in->variant.hardLinkVariant.equivalentObjectId =
1472                                                                 equivalentObjectId;
1473                                                         in->hardLinks.next =
1474                                                                 (struct ylist_head *) hardList;
1475                                                         hardList = in;
1476                                                 }
1477                                                 break;
1478                                         case YAFFS_OBJECT_TYPE_DIRECTORY:
1479                                                 /* Do nothing */
1480                                                 break;
1481                                         case YAFFS_OBJECT_TYPE_SPECIAL:
1482                                                 /* Do nothing */
1483                                                 break;
1484                                         case YAFFS_OBJECT_TYPE_SYMLINK:
1485                                                 if (oh) {
1486                                                         in->variant.symLinkVariant.alias =
1487                                                                 yaffs_CloneString(oh->alias);
1488                                                         if (!in->variant.symLinkVariant.alias)
1489                                                                 alloc_failed = 1;
1490                                                 }
1491                                                 break;
1492                                         }
1493
1494                                 }
1495
1496                         }
1497
1498                 } /* End of scanning for each chunk */
1499
1500                 if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
1501                         /* If we got this far while scanning, then the block is fully allocated. */
1502                         state = YAFFS_BLOCK_STATE_FULL;
1503                 }
1504
1505
1506                 bi->blockState = state;
1507
1508                 /* Now let's see if it was dirty */
1509                 if (bi->pagesInUse == 0 &&
1510                     !bi->hasShrinkHeader &&
1511                     bi->blockState == YAFFS_BLOCK_STATE_FULL) {
1512                         yaffs_BlockBecameDirty(dev, blk);
1513                 }
1514
1515         }
1516
1517         yaffs_SkipRestOfBlock(dev);
1518
1519         if (altBlockIndex)
1520                 YFREE_ALT(blockIndex);
1521         else
1522                 YFREE(blockIndex);
1523
1524         /* Ok, we've done all the scanning.
1525          * Fix up the hard link chains.
1526          * We should now have scanned all the objects, now it's time to add these
1527          * hardlinks.
1528          */
1529         yaffs_HardlinkFixup(dev, hardList);
1530
1531
1532         yaffs_ReleaseTempBuffer(dev, chunkData, __LINE__);
1533
1534         if (alloc_failed)
1535                 return YAFFS_FAIL;
1536
1537         T(YAFFS_TRACE_SCAN, (TSTR("yaffs2_ScanBackwards ends" TENDSTR)));
1538
1539         return YAFFS_OK;
1540 }