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_dev_t *dev)
  22 {
  23         yaffs_ext_tags 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_block_state_t state;
  34         yaffs_obj_t *hard_list = NULL;
  35         yaffs_block_info_t *bi;
  36         __u32 seq_number;
  37         yaffs_obj_header *oh;
  38         yaffs_obj_t *in;
  39         yaffs_obj_t *parent;
  40
  41         int alloc_failed = 0;
  42
  43         struct yaffs_shadow_fixer_s *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->internal_start_block, dev->internal_end_block));
  53
  54         chunkData = yaffs_get_temp_buffer(dev, __LINE__);
  55
  56         dev->seq_number = YAFFS_LOWEST_SEQUENCE_NUMBER;
  57
  58         /* Scan all the blocks to determine their state */
  59         bi = dev->block_info;
  60         for (blk = dev->internal_start_block; blk <= dev->internal_end_block; blk++) {
  61                 yaffs_clear_chunk_bits(dev, blk);
  62                 bi->pages_in_use = 0;
  63                 bi->soft_del_pages = 0;
  64
  65                 yaffs_query_init_block_state(dev, blk, &state, &seq_number);
  66
  67                 bi->block_state = state;
  68                 bi->seq_number = seq_number;
  69
  70                 if (bi->seq_number == YAFFS_SEQUENCE_BAD_BLOCK)
  71                         bi->block_state = 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, seq_number));
  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->n_erased_blocks++;
  84                         dev->n_free_chunks += dev->param.chunks_per_block;
  85                 }
  86                 bi++;
  87         }
  88
  89         startIterator = dev->internal_start_block;
  90         endIterator = dev->internal_end_block;
  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_get_block_info(dev, blk);
 103                 state = bi->block_state;
 104
 105                 deleted = 0;
 106
 107                 /* For each chunk in each block that needs scanning....*/
 108                 for (c = 0; !alloc_failed && c < dev->param.chunks_per_block &&
 109                      state == YAFFS_BLOCK_STATE_NEEDS_SCANNING; c++) {
 110                         /* Read the tags and decide what to do */
 111                         chunk = blk * dev->param.chunks_per_block + c;
 112
 113                         result = yaffs_rd_chunk_tags_nand(dev, chunk, NULL,
 114                                                         &tags);
 115
 116                         /* Let's have a good look at this chunk... */
 117
 118                         if (tags.ecc_result == YAFFS_ECC_RESULT_UNFIXED || tags.is_deleted) {
 119                                 /* YAFFS1 only...
 120                                  * A deleted chunk
 121                                  */
 122                                 deleted++;
 123                                 dev->n_free_chunks++;
 124                                 /*T((" %d %d deleted\n",blk,c)); */
 125                         } else if (!tags.chunk_used) {
 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->n_erased_blocks++;
 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->alloc_block = blk;
 143                                         dev->alloc_page = c;
 144                                         dev->alloc_block_finder = blk;
 145                                         /* Set block finder here to encourage the allocator to go forth from here. */
 146
 147                                 }
 148
 149                                 dev->n_free_chunks += (dev->param.chunks_per_block - c);
 150                         } else if (tags.chunk_id > 0) {
 151                                 /* chunk_id > 0 so it is a data chunk... */
 152                                 unsigned int endpos;
 153
 154                                 yaffs_set_chunk_bit(dev, blk, c);
 155                                 bi->pages_in_use++;
 156
 157                                 in = yaffs_find_or_create_by_number(dev,
 158                                                                       tags.
 159                                                                       obj_id,
 160                                                                       YAFFS_OBJECT_TYPE_FILE);
 161                                 /* PutChunkIntoFile checks for a clash (two data chunks with
 162                                  * the same chunk_id).
 163                                  */
 164
 165                                 if (!in)
 166                                         alloc_failed = 1;
 167
 168                                 if (in) {
 169                                         if (!yaffs_put_chunk_in_file(in, tags.chunk_id, chunk, 1))
 170                                                 alloc_failed = 1;
 171                                 }
 172
 173                                 endpos =
 174                                     (tags.chunk_id - 1) * dev->data_bytes_per_chunk +
 175                                     tags.n_bytes;
 176                                 if (in &&
 177                                     in->variant_type == YAFFS_OBJECT_TYPE_FILE
 178                                     && in->variant.file_variant.scanned_size <
 179                                     endpos) {
 180                                         in->variant.file_variant.
 181                                             scanned_size = endpos;
 182                                         if (!dev->param.use_header_file_size) {
 183                                                 in->variant.file_variant.
 184                                                     file_size =
 185                                                     in->variant.file_variant.
 186                                                     scanned_size;
 187                                         }
 188
 189                                 }
 190                                 /* T((" %d %d data %d %d\n",blk,c,tags.obj_id,tags.chunk_id));   */
 191                         } else {
 192                                 /* chunk_id == 0, so it is an ObjectHeader.
 193                                  * Thus, we read in the object header and make the object
 194                                  */
 195                                 yaffs_set_chunk_bit(dev, blk, c);
 196                                 bi->pages_in_use++;
 197
 198                                 result = yaffs_rd_chunk_tags_nand(dev, chunk,
 199                                                                 chunkData,
 200                                                                 NULL);
 201
 202                                 oh = (yaffs_obj_header *) chunkData;
 203
 204                                 in = yaffs_find_by_number(dev,
 205                                                               tags.obj_id);
 206                                 if (in && in->variant_type != oh->type) {
 207                                         /* This should not happen, but somehow
 208                                          * Wev'e ended up with an obj_id that has been reused but not yet
 209                                          * deleted, and worse still it has changed type. Delete the old object.
 210                                          */
 211
 212                                         yaffs_del_obj(in);
 213
 214                                         in = 0;
 215                                 }
 216
 217                                 in = yaffs_find_or_create_by_number(dev,
 218                                                                       tags.
 219                                                                       obj_id,
 220                                                                       oh->type);
 221
 222                                 if (!in)
 223                                         alloc_failed = 1;
 224
 225                                 if (in && oh->shadows_obj > 0) {
 226
 227                                         struct yaffs_shadow_fixer_s *fixer;
 228                                         fixer = YMALLOC(sizeof(struct yaffs_shadow_fixer_s));
 229                                         if (fixer) {
 230                                                 fixer->next = shadowFixerList;
 231                                                 shadowFixerList = fixer;
 232                                                 fixer->obj_id = tags.obj_id;
 233                                                 fixer->shadowed_id = oh->shadows_obj;
 234                                                 T(YAFFS_TRACE_SCAN,
 235                                                   (TSTR
 236                                                    (" Shadow fixer: %d shadows %d" TENDSTR),
 237                                                    fixer->obj_id, fixer->shadowed_id));
 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.serial_number;
 248
 249                                         if (((existingSerial + 1) & 3) == newSerial) {
 250                                                 /* Use new one - destroy the exisiting one */
 251                                                 yaffs_chunk_del(dev,
 252                                                                   in->hdr_chunk,
 253                                                                   1, __LINE__);
 254                                                 in->valid = 0;
 255                                         } else {
 256                                                 /* Use existing - destroy this one. */
 257                                                 yaffs_chunk_del(dev, chunk, 1,
 258                                                                   __LINE__);
 259                                         }
 260                                 }
 261
 262                                 if (in && !in->valid &&
 263                                     (tags.obj_id == YAFFS_OBJECTID_ROOT ||
 264                                      tags.obj_id == YAFFS_OBJECTID_LOSTNFOUND)) {
 265                                         /* We only load some info, don't fiddle with directory structure */
 266                                         in->valid = 1;
 267                                         in->variant_type = 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->hdr_chunk = chunk;
 286                                         in->serial = tags.serial_number;
 287
 288                                 } else if (in && !in->valid) {
 289                                         /* we need to load this info */
 290
 291                                         in->valid = 1;
 292                                         in->variant_type = 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->hdr_chunk = chunk;
 311                                         in->serial = tags.serial_number;
 312
 313                                         yaffs_set_obj_name_from_oh(in, oh);
 314                                         in->dirty = 0;
 315
 316                                         /* directory stuff...
 317                                          * hook up to parent
 318                                          */
 319
 320                                         parent =
 321                                             yaffs_find_or_create_by_number
 322                                             (dev, oh->parent_obj_id,
 323                                              YAFFS_OBJECT_TYPE_DIRECTORY);
 324                                         if (!parent)
 325                                                 alloc_failed = 1;
 326                                         if (parent && parent->variant_type ==
 327                                             YAFFS_OBJECT_TYPE_UNKNOWN) {
 328                                                 /* Set up as a directory */
 329                                                 parent->variant_type =
 330                                                         YAFFS_OBJECT_TYPE_DIRECTORY;
 331                                                 YINIT_LIST_HEAD(&parent->variant.
 332                                                                 dir_variant.
 333                                                                 children);
 334                                         } else if (!parent || parent->variant_type !=
 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->lost_n_found;
 345                                         }
 346
 347                                         yaffs_add_obj_to_dir(parent, in);
 348
 349                                         if (0 && (parent == dev->del_dir ||
 350                                                   parent == dev->unlinked_dir)) {
 351                                                 in->deleted = 1;        /* If it is unlinked at start up then it wants deleting */
 352                                                 dev->n_deleted_files++;
 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->variant_type) {
 362                                         case YAFFS_OBJECT_TYPE_UNKNOWN:
 363                                                 /* Todo got a problem */
 364                                                 break;
 365                                         case YAFFS_OBJECT_TYPE_FILE:
 366                                                 if (dev->param.use_header_file_size)
 367
 368                                                         in->variant.file_variant.
 369                                                             file_size =
 370                                                             oh->file_size;
 371
 372                                                 break;
 373                                         case YAFFS_OBJECT_TYPE_HARDLINK:
 374                                                 in->variant.hardlink_variant.
 375                                                         equiv_id =
 376                                                         oh->equiv_id;
 377                                                 in->hard_links.next =
 378                                                         (struct ylist_head *)
 379                                                         hard_list;
 380                                                 hard_list = 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.symlink_variant.alias =
 390                                                     yaffs_clone_str(oh->alias);
 391                                                 if (!in->variant.symlink_variant.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->alloc_block = -1;
 409                 }
 410
 411                 bi->block_state = state;
 412
 413                 /* Now let's see if it was dirty */
 414                 if (bi->pages_in_use == 0 &&
 415                     !bi->has_shrink_hdr &&
 416                     bi->block_state == YAFFS_BLOCK_STATE_FULL) {
 417                         yaffs_block_became_dirty(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_link_fixup(dev, hard_list);
 430
 431         /* Fix up any shadowed objects */
 432         {
 433                 struct yaffs_shadow_fixer_s *fixer;
 434                 yaffs_obj_t *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_find_by_number(dev, fixer->shadowed_id);
 443                         if (obj)
 444                                 yaffs_del_obj(obj);
 445
 446                         obj = yaffs_find_by_number(dev, fixer->obj_id);
 447
 448                         if (obj)
 449                                 yaffs_update_oh(obj, NULL, 1, 0, 0, NULL);
 450
 451                         YFREE(fixer);
 452                 }
 453         }
 454
 455         yaffs_release_temp_buffer(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