yaffs_yaffs1.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 #include "yaffs_yaffs1.h"
  14 #include "yportenv.h"
  15 #include "yaffs_trace.h"
  16 #include "yaffs_bitmap.h"
  17 #include "yaffs_getblockinfo.h"
  18 #include "yaffs_nand.h"
  19
  20
  21 int yaffs1_Scan(yaffs_Device *dev)
  22 {
  23         yaffs_ExtendedTags tags;
  24         int blk;
  25         int blockIterator;
  26         int startIterator;
  27         int endIterator;
  28         int result;
  29
  30         int chunk;
  31         int c;
  32         int deleted;
  33         yaffs_BlockState state;
  34         yaffs_Object *hardList = NULL;
  35         yaffs_BlockInfo *bi;
  36         __u32 sequenceNumber;
  37         yaffs_ObjectHeader *oh;
  38         yaffs_Object *in;
  39         yaffs_Object *parent;
  40
  41         int alloc_failed = 0;
  42
  43         struct yaffs_ShadowFixerStruct *shadowFixerList = NULL;
  44
  45
  46         __u8 *chunkData;
  47
  48
  49
  50         T(YAFFS_TRACE_SCAN,
  51           (TSTR("yaffs1_Scan starts  intstartblk %d intendblk %d..." TENDSTR),
  52            dev->internalStartBlock, dev->internalEndBlock));
  53
  54         chunkData = yaffs_GetTempBuffer(dev, __LINE__);
  55
  56         dev->sequenceNumber = YAFFS_LOWEST_SEQUENCE_NUMBER;
  57
  58         /* Scan all the blocks to determine their state */
  59         bi = dev->blockInfo;
  60         for (blk = dev->internalStartBlock; blk <= dev->internalEndBlock; blk++) {
  61                 yaffs_ClearChunkBits(dev, blk);
  62                 bi->pagesInUse = 0;
  63                 bi->softDeletions = 0;
  64
  65                 yaffs_QueryInitialBlockState(dev, blk, &state, &sequenceNumber);
  66
  67                 bi->blockState = state;
  68                 bi->sequenceNumber = sequenceNumber;
  69
  70                 if (bi->sequenceNumber == YAFFS_SEQUENCE_BAD_BLOCK)
  71                         bi->blockState = state = YAFFS_BLOCK_STATE_DEAD;
  72
  73                 T(YAFFS_TRACE_SCAN_DEBUG,
  74                   (TSTR("Block scanning block %d state %d seq %d" TENDSTR), blk,
  75                    state, sequenceNumber));
  76
  77                 if (state == YAFFS_BLOCK_STATE_DEAD) {
  78                         T(YAFFS_TRACE_BAD_BLOCKS,
  79                           (TSTR("block %d is bad" TENDSTR), blk));
  80                 } else if (state == YAFFS_BLOCK_STATE_EMPTY) {
  81                         T(YAFFS_TRACE_SCAN_DEBUG,
  82                           (TSTR("Block empty " TENDSTR)));
  83                         dev->nErasedBlocks++;
  84                         dev->nFreeChunks += dev->param.nChunksPerBlock;
  85                 }
  86                 bi++;
  87         }
  88
  89         startIterator = dev->internalStartBlock;
  90         endIterator = dev->internalEndBlock;
  91
  92         /* For each block.... */
  93         for (blockIterator = startIterator; !alloc_failed && blockIterator <= endIterator;
  94              blockIterator++) {
  95
  96                 YYIELD();
  97
  98                 YYIELD();
  99
 100                 blk = blockIterator;
 101
 102                 bi = yaffs_GetBlockInfo(dev, blk);
 103                 state = bi->blockState;
 104
 105                 deleted = 0;
 106
 107                 /* For each chunk in each block that needs scanning....*/
 108                 for (c = 0; !alloc_failed && c < dev->param.nChunksPerBlock &&
 109                      state == YAFFS_BLOCK_STATE_NEEDS_SCANNING; c++) {
 110                         /* Read the tags and decide what to do */
 111                         chunk = blk * dev->param.nChunksPerBlock + c;
 112
 113                         result = yaffs_ReadChunkWithTagsFromNAND(dev, chunk, NULL,
 114                                                         &tags);
 115
 116                         /* Let's have a good look at this chunk... */
 117
 118                         if (tags.eccResult == YAFFS_ECC_RESULT_UNFIXED || tags.chunkDeleted) {
 119                                 /* YAFFS1 only...
 120                                  * A deleted chunk
 121                                  */
 122                                 deleted++;
 123                                 dev->nFreeChunks++;
 124                                 /*T((" %d %d deleted\n",blk,c)); */
 125                         } else if (!tags.chunkUsed) {
 126                                 /* An unassigned chunk in the block
 127                                  * This means that either the block is empty or
 128                                  * this is the one being allocated from
 129                                  */
 130
 131                                 if (c == 0) {
 132                                         /* We're looking at the first chunk in the block so the block is unused */
 133                                         state = YAFFS_BLOCK_STATE_EMPTY;
 134                                         dev->nErasedBlocks++;
 135                                 } else {
 136                                         /* this is the block being allocated from */
 137                                         T(YAFFS_TRACE_SCAN,
 138                                           (TSTR
 139                                            (" Allocating from %d %d" TENDSTR),
 140                                            blk, c));
 141                                         state = YAFFS_BLOCK_STATE_ALLOCATING;
 142                                         dev->allocationBlock = blk;
 143                                         dev->allocationPage = c;
 144                                         dev->allocationBlockFinder = blk;
 145                                         /* Set block finder here to encourage the allocator to go forth from here. */
 146
 147                                 }
 148
 149                                 dev->nFreeChunks += (dev->param.nChunksPerBlock - c);
 150                         } else if (tags.chunkId > 0) {
 151                                 /* chunkId > 0 so it is a data chunk... */
 152                                 unsigned int endpos;
 153
 154                                 yaffs_SetChunkBit(dev, blk, c);
 155                                 bi->pagesInUse++;
 156
 157                                 in = yaffs_FindOrCreateObjectByNumber(dev,
 158                                                                       tags.
 159                                                                       objectId,
 160                                                                       YAFFS_OBJECT_TYPE_FILE);
 161                                 /* PutChunkIntoFile checks for a clash (two data chunks with
 162                                  * the same chunkId).
 163                                  */
 164
 165                                 if (!in)
 166                                         alloc_failed = 1;
 167
 168                                 if (in) {
 169                                         if (!yaffs_PutChunkIntoFile(in, tags.chunkId, chunk, 1))
 170                                                 alloc_failed = 1;
 171                                 }
 172
 173                                 endpos =
 174                                     (tags.chunkId - 1) * dev->nDataBytesPerChunk +
 175                                     tags.byteCount;
 176                                 if (in &&
 177                                     in->variantType == YAFFS_OBJECT_TYPE_FILE
 178                                     && in->variant.fileVariant.scannedFileSize <
 179                                     endpos) {
 180                                         in->variant.fileVariant.
 181                                             scannedFileSize = endpos;
 182                                         if (!dev->param.useHeaderFileSize) {
 183                                                 in->variant.fileVariant.
 184                                                     fileSize =
 185                                                     in->variant.fileVariant.
 186                                                     scannedFileSize;
 187                                         }
 188
 189                                 }
 190                                 /* T((" %d %d data %d %d\n",blk,c,tags.objectId,tags.chunkId));   */
 191                         } else {
 192                                 /* chunkId == 0, so it is an ObjectHeader.
 193                                  * Thus, we read in the object header and make the object
 194                                  */
 195                                 yaffs_SetChunkBit(dev, blk, c);
 196                                 bi->pagesInUse++;
 197
 198                                 result = yaffs_ReadChunkWithTagsFromNAND(dev, chunk,
 199                                                                 chunkData,
 200                                                                 NULL);
 201
 202                                 oh = (yaffs_ObjectHeader *) chunkData;
 203
 204                                 in = yaffs_FindObjectByNumber(dev,
 205                                                               tags.objectId);
 206                                 if (in && in->variantType != oh->type) {
 207                                         /* This should not happen, but somehow
 208                                          * Wev'e ended up with an objectId that has been reused but not yet
 209                                          * deleted, and worse still it has changed type. Delete the old object.
 210                                          */
 211
 212                                         yaffs_DeleteObject(in);
 213
 214                                         in = 0;
 215                                 }
 216
 217                                 in = yaffs_FindOrCreateObjectByNumber(dev,
 218                                                                       tags.
 219                                                                       objectId,
 220                                                                       oh->type);
 221
 222                                 if (!in)
 223                                         alloc_failed = 1;
 224
 225                                 if (in && oh->shadowsObject > 0) {
 226
 227                                         struct yaffs_ShadowFixerStruct *fixer;
 228                                         fixer = YMALLOC(sizeof(struct yaffs_ShadowFixerStruct));
 229                                         if (fixer) {
 230                                                 fixer->next = shadowFixerList;
 231                                                 shadowFixerList = fixer;
 232                                                 fixer->objectId = tags.objectId;
 233                                                 fixer->shadowedId = oh->shadowsObject;
 234                                                 T(YAFFS_TRACE_SCAN,
 235                                                   (TSTR
 236                                                    (" Shadow fixer: %d shadows %d" TENDSTR),
 237                                                    fixer->objectId, fixer->shadowedId));
 238
 239                                         }
 240
 241                                 }
 242
 243                                 if (in && in->valid) {
 244                                         /* We have already filled this one. We have a duplicate and need to resolve it. */
 245
 246                                         unsigned existingSerial = in->serial;
 247                                         unsigned newSerial = tags.serialNumber;
 248
 249                                         if (((existingSerial + 1) & 3) == newSerial) {
 250                                                 /* Use new one - destroy the exisiting one */
 251                                                 yaffs_DeleteChunk(dev,
 252                                                                   in->hdrChunk,
 253                                                                   1, __LINE__);
 254                                                 in->valid = 0;
 255                                         } else {
 256                                                 /* Use existing - destroy this one. */
 257                                                 yaffs_DeleteChunk(dev, chunk, 1,
 258                                                                   __LINE__);
 259                                         }
 260                                 }
 261
 262                                 if (in && !in->valid &&
 263                                     (tags.objectId == YAFFS_OBJECTID_ROOT ||
 264                                      tags.objectId == YAFFS_OBJECTID_LOSTNFOUND)) {
 265                                         /* We only load some info, don't fiddle with directory structure */
 266                                         in->valid = 1;
 267                                         in->variantType = oh->type;
 268
 269                                         in->yst_mode = oh->yst_mode;
 270 #ifdef CONFIG_YAFFS_WINCE
 271                                         in->win_atime[0] = oh->win_atime[0];
 272                                         in->win_ctime[0] = oh->win_ctime[0];
 273                                         in->win_mtime[0] = oh->win_mtime[0];
 274                                         in->win_atime[1] = oh->win_atime[1];
 275                                         in->win_ctime[1] = oh->win_ctime[1];
 276                                         in->win_mtime[1] = oh->win_mtime[1];
 277 #else
 278                                         in->yst_uid = oh->yst_uid;
 279                                         in->yst_gid = oh->yst_gid;
 280                                         in->yst_atime = oh->yst_atime;
 281                                         in->yst_mtime = oh->yst_mtime;
 282                                         in->yst_ctime = oh->yst_ctime;
 283                                         in->yst_rdev = oh->yst_rdev;
 284 #endif
 285                                         in->hdrChunk = chunk;
 286                                         in->serial = tags.serialNumber;
 287
 288                                 } else if (in && !in->valid) {
 289                                         /* we need to load this info */
 290
 291                                         in->valid = 1;
 292                                         in->variantType = oh->type;
 293
 294                                         in->yst_mode = oh->yst_mode;
 295 #ifdef CONFIG_YAFFS_WINCE
 296                                         in->win_atime[0] = oh->win_atime[0];
 297                                         in->win_ctime[0] = oh->win_ctime[0];
 298                                         in->win_mtime[0] = oh->win_mtime[0];
 299                                         in->win_atime[1] = oh->win_atime[1];
 300                                         in->win_ctime[1] = oh->win_ctime[1];
 301                                         in->win_mtime[1] = oh->win_mtime[1];
 302 #else
 303                                         in->yst_uid = oh->yst_uid;
 304                                         in->yst_gid = oh->yst_gid;
 305                                         in->yst_atime = oh->yst_atime;
 306                                         in->yst_mtime = oh->yst_mtime;
 307                                         in->yst_ctime = oh->yst_ctime;
 308                                         in->yst_rdev = oh->yst_rdev;
 309 #endif
 310                                         in->hdrChunk = chunk;
 311                                         in->serial = tags.serialNumber;
 312
 313                                         yaffs_SetObjectNameFromOH(in, oh);
 314                                         in->dirty = 0;
 315
 316                                         /* directory stuff...
 317                                          * hook up to parent
 318                                          */
 319
 320                                         parent =
 321                                             yaffs_FindOrCreateObjectByNumber
 322                                             (dev, oh->parentObjectId,
 323                                              YAFFS_OBJECT_TYPE_DIRECTORY);
 324                                         if (!parent)
 325                                                 alloc_failed = 1;
 326                                         if (parent && parent->variantType ==
 327                                             YAFFS_OBJECT_TYPE_UNKNOWN) {
 328                                                 /* Set up as a directory */
 329                                                 parent->variantType =
 330                                                         YAFFS_OBJECT_TYPE_DIRECTORY;
 331                                                 YINIT_LIST_HEAD(&parent->variant.
 332                                                                 directoryVariant.
 333                                                                 children);
 334                                         } else if (!parent || parent->variantType !=
 335                                                    YAFFS_OBJECT_TYPE_DIRECTORY) {
 336                                                 /* Hoosterman, another problem....
 337                                                  * We're trying to use a non-directory as a directory
 338                                                  */
 339
 340                                                 T(YAFFS_TRACE_ERROR,
 341                                                   (TSTR
 342                                                    ("yaffs tragedy: attempting to use non-directory as a directory in scan. Put in lost+found."
 343                                                     TENDSTR)));
 344                                                 parent = dev->lostNFoundDir;
 345                                         }
 346
 347                                         yaffs_AddObjectToDirectory(parent, in);
 348
 349                                         if (0 && (parent == dev->deletedDir ||
 350                                                   parent == dev->unlinkedDir)) {
 351                                                 in->deleted = 1;        /* If it is unlinked at start up then it wants deleting */
 352                                                 dev->nDeletedFiles++;
 353                                         }
 354                                         /* Note re hardlinks.
 355                                          * Since we might scan a hardlink before its equivalent object is scanned
 356                                          * we put them all in a list.
 357                                          * After scanning is complete, we should have all the objects, so we run through this
 358                                          * list and fix up all the chains.
 359                                          */
 360
 361                                         switch (in->variantType) {
 362                                         case YAFFS_OBJECT_TYPE_UNKNOWN:
 363                                                 /* Todo got a problem */
 364                                                 break;
 365                                         case YAFFS_OBJECT_TYPE_FILE:
 366                                                 if (dev->param.useHeaderFileSize)
 367
 368                                                         in->variant.fileVariant.
 369                                                             fileSize =
 370                                                             oh->fileSize;
 371
 372                                                 break;
 373                                         case YAFFS_OBJECT_TYPE_HARDLINK:
 374                                                 in->variant.hardLinkVariant.
 375                                                         equivalentObjectId =
 376                                                         oh->equivalentObjectId;
 377                                                 in->hardLinks.next =
 378                                                         (struct ylist_head *)
 379                                                         hardList;
 380                                                 hardList = in;
 381                                                 break;
 382                                         case YAFFS_OBJECT_TYPE_DIRECTORY:
 383                                                 /* Do nothing */
 384                                                 break;
 385                                         case YAFFS_OBJECT_TYPE_SPECIAL:
 386                                                 /* Do nothing */
 387                                                 break;
 388                                         case YAFFS_OBJECT_TYPE_SYMLINK:
 389                                                 in->variant.symLinkVariant.alias =
 390                                                     yaffs_CloneString(oh->alias);
 391                                                 if (!in->variant.symLinkVariant.alias)
 392                                                         alloc_failed = 1;
 393                                                 break;
 394                                         }
 395
 396                                 }
 397                         }
 398                 }
 399
 400                 if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
 401                         /* If we got this far while scanning, then the block is fully allocated.*/
 402                         state = YAFFS_BLOCK_STATE_FULL;
 403                 }
 404
 405                 if (state == YAFFS_BLOCK_STATE_ALLOCATING) {
 406                         /* If the block was partially allocated then treat it as fully allocated.*/
 407                         state = YAFFS_BLOCK_STATE_FULL;
 408                         dev->allocationBlock = -1;
 409                 }
 410
 411                 bi->blockState = state;
 412
 413                 /* Now let's see if it was dirty */
 414                 if (bi->pagesInUse == 0 &&
 415                     !bi->hasShrinkHeader &&
 416                     bi->blockState == YAFFS_BLOCK_STATE_FULL) {
 417                         yaffs_BlockBecameDirty(dev, blk);
 418                 }
 419
 420         }
 421
 422
 423         /* Ok, we've done all the scanning.
 424          * Fix up the hard link chains.
 425          * We should now have scanned all the objects, now it's time to add these
 426          * hardlinks.
 427          */
 428
 429         yaffs_HardlinkFixup(dev, hardList);
 430
 431         /* Fix up any shadowed objects */
 432         {
 433                 struct yaffs_ShadowFixerStruct *fixer;
 434                 yaffs_Object *obj;
 435
 436                 while (shadowFixerList) {
 437                         fixer = shadowFixerList;
 438                         shadowFixerList = fixer->next;
 439                         /* Complete the rename transaction by deleting the shadowed object
 440                          * then setting the object header to unshadowed.
 441                          */
 442                         obj = yaffs_FindObjectByNumber(dev, fixer->shadowedId);
 443                         if (obj)
 444                                 yaffs_DeleteObject(obj);
 445
 446                         obj = yaffs_FindObjectByNumber(dev, fixer->objectId);
 447
 448                         if (obj)
 449                                 yaffs_UpdateObjectHeader(obj, NULL, 1, 0, 0, NULL);
 450
 451                         YFREE(fixer);
 452                 }
 453         }
 454
 455         yaffs_ReleaseTempBuffer(dev, chunkData, __LINE__);
 456
 457         if (alloc_failed)
 458                 return YAFFS_FAIL;
 459
 460         T(YAFFS_TRACE_SCAN, (TSTR("yaffs1_Scan ends" TENDSTR)));
 461
 462
 463         return YAFFS_OK;
 464 }
 465