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
  14 #include "yaffs_yaffs1.h"
  15 #include "yportenv.h"
  16 #include "yaffs_trace.h"
  17 #include "yaffs_bitmap.h"
  18 #include "yaffs_getblockinfo.h"
  19 #include "yaffs_nand.h"
  20
  21
  22 int yaffs1_scan(yaffs_dev_t *dev)
  23 {
  24         yaffs_ext_tags tags;
  25         int blk;
  26         int blockIterator;
  27         int startIterator;
  28         int endIterator;
  29         int result;
  30
  31         int chunk;
  32         int c;
  33         int deleted;
  34         yaffs_block_state_t state;
  35         yaffs_obj_t *hard_list = NULL;
  36         yaffs_block_info_t *bi;
  37         __u32 seq_number;
  38         yaffs_obj_header *oh;
  39         yaffs_obj_t *in;
  40         yaffs_obj_t *parent;
  41
  42         int alloc_failed = 0;
  43
  44         struct yaffs_shadow_fixer_s *shadowFixerList = NULL;
  45
  46
  47         __u8 *chunkData;
  48
  49
  50
  51         T(YAFFS_TRACE_SCAN,
  52           (TSTR("yaffs1_scan starts  intstartblk %d intendblk %d..." TENDSTR),
  53            dev->internal_start_block, dev->internal_end_block));
  54
  55         chunkData = yaffs_get_temp_buffer(dev, __LINE__);
  56
  57         dev->seq_number = YAFFS_LOWEST_SEQUENCE_NUMBER;
  58
  59         /* Scan all the blocks to determine their state */
  60         bi = dev->block_info;
  61         for (blk = dev->internal_start_block; blk <= dev->internal_end_block; blk++) {
  62                 yaffs_clear_chunk_bits(dev, blk);
  63                 bi->pages_in_use = 0;
  64                 bi->soft_del_pages = 0;
  65
  66                 yaffs_query_init_block_state(dev, blk, &state, &seq_number);
  67
  68                 bi->block_state = state;
  69                 bi->seq_number = seq_number;
  70
  71                 if (bi->seq_number == YAFFS_SEQUENCE_BAD_BLOCK)
  72                         bi->block_state = state = YAFFS_BLOCK_STATE_DEAD;
  73
  74                 T(YAFFS_TRACE_SCAN_DEBUG,
  75                   (TSTR("Block scanning block %d state %d seq %d" TENDSTR), blk,
  76                    state, seq_number));
  77
  78                 if (state == YAFFS_BLOCK_STATE_DEAD) {
  79                         T(YAFFS_TRACE_BAD_BLOCKS,
  80                           (TSTR("block %d is bad" TENDSTR), blk));
  81                 } else if (state == YAFFS_BLOCK_STATE_EMPTY) {
  82                         T(YAFFS_TRACE_SCAN_DEBUG,
  83                           (TSTR("Block empty " TENDSTR)));
  84                         dev->n_erased_blocks++;
  85                         dev->n_free_chunks += dev->param.chunks_per_block;
  86                 }
  87                 bi++;
  88         }
  89
  90         startIterator = dev->internal_start_block;
  91         endIterator = dev->internal_end_block;
  92
  93         /* For each block.... */
  94         for (blockIterator = startIterator; !alloc_failed && blockIterator <= endIterator;
  95              blockIterator++) {
  96
  97                 YYIELD();
  98
  99                 YYIELD();
 100
 101                 blk = blockIterator;
 102
 103                 bi = yaffs_get_block_info(dev, blk);
 104                 state = bi->block_state;
 105
 106                 deleted = 0;
 107
 108                 /* For each chunk in each block that needs scanning....*/
 109                 for (c = 0; !alloc_failed && c < dev->param.chunks_per_block &&
 110                      state == YAFFS_BLOCK_STATE_NEEDS_SCANNING; c++) {
 111                         /* Read the tags and decide what to do */
 112                         chunk = blk * dev->param.chunks_per_block + c;
 113
 114                         result = yaffs_rd_chunk_tags_nand(dev, chunk, NULL,
 115                                                         &tags);
 116
 117                         /* Let's have a good look at this chunk... */
 118
 119                         if (tags.ecc_result == YAFFS_ECC_RESULT_UNFIXED || tags.is_deleted) {
 120                                 /* YAFFS1 only...
 121                                  * A deleted chunk
 122                                  */
 123                                 deleted++;
 124                                 dev->n_free_chunks++;
 125                                 /*T((" %d %d deleted\n",blk,c)); */
 126                         } else if (!tags.chunk_used) {
 127                                 /* An unassigned chunk in the block
 128                                  * This means that either the block is empty or
 129                                  * this is the one being allocated from
 130                                  */
 131
 132                                 if (c == 0) {
 133                                         /* We're looking at the first chunk in the block so the block is unused */
 134                                         state = YAFFS_BLOCK_STATE_EMPTY;
 135                                         dev->n_erased_blocks++;
 136                                 } else {
 137                                         /* this is the block being allocated from */
 138                                         T(YAFFS_TRACE_SCAN,
 139                                           (TSTR
 140                                            (" Allocating from %d %d" TENDSTR),
 141                                            blk, c));
 142                                         state = YAFFS_BLOCK_STATE_ALLOCATING;
 143                                         dev->alloc_block = blk;
 144                                         dev->alloc_page = c;
 145                                         dev->alloc_block_finder = blk;
 146                                         /* Set block finder here to encourage the allocator to go forth from here. */
 147
 148                                 }
 149
 150                                 dev->n_free_chunks += (dev->param.chunks_per_block - c);
 151                         } else if (tags.chunk_id > 0) {
 152                                 /* chunk_id > 0 so it is a data chunk... */
 153                                 unsigned int endpos;
 154
 155                                 yaffs_set_chunk_bit(dev, blk, c);
 156                                 bi->pages_in_use++;
 157
 158                                 in = yaffs_find_or_create_by_number(dev,
 159                                                                       tags.
 160                                                                       obj_id,
 161                                                                       YAFFS_OBJECT_TYPE_FILE);
 162                                 /* PutChunkIntoFile checks for a clash (two data chunks with
 163                                  * the same chunk_id).
 164                                  */
 165
 166                                 if (!in)
 167                                         alloc_failed = 1;
 168
 169                                 if (in) {
 170                                         if (!yaffs_put_chunk_in_file(in, tags.chunk_id, chunk, 1))
 171                                                 alloc_failed = 1;
 172                                 }
 173
 174                                 endpos =
 175                                     (tags.chunk_id - 1) * dev->data_bytes_per_chunk +
 176                                     tags.n_bytes;
 177                                 if (in &&
 178                                     in->variant_type == YAFFS_OBJECT_TYPE_FILE
 179                                     && in->variant.file_variant.scanned_size <
 180                                     endpos) {
 181                                         in->variant.file_variant.
 182                                             scanned_size = endpos;
 183                                         if (!dev->param.use_header_file_size) {
 184                                                 in->variant.file_variant.
 185                                                     file_size =
 186                                                     in->variant.file_variant.
 187                                                     scanned_size;
 188                                         }
 189
 190                                 }
 191                                 /* T((" %d %d data %d %d\n",blk,c,tags.obj_id,tags.chunk_id));   */
 192                         } else {
 193                                 /* chunk_id == 0, so it is an ObjectHeader.
 194                                  * Thus, we read in the object header and make the object
 195                                  */
 196                                 yaffs_set_chunk_bit(dev, blk, c);
 197                                 bi->pages_in_use++;
 198
 199                                 result = yaffs_rd_chunk_tags_nand(dev, chunk,
 200                                                                 chunkData,
 201                                                                 NULL);
 202
 203                                 oh = (yaffs_obj_header *) chunkData;
 204
 205                                 in = yaffs_find_by_number(dev,
 206                                                               tags.obj_id);
 207                                 if (in && in->variant_type != oh->type) {
 208                                         /* This should not happen, but somehow
 209                                          * Wev'e ended up with an obj_id that has been reused but not yet
 210                                          * deleted, and worse still it has changed type. Delete the old object.
 211                                          */
 212
 213                                         yaffs_del_obj(in);
 214
 215                                         in = 0;
 216                                 }
 217
 218                                 in = yaffs_find_or_create_by_number(dev,
 219                                                                       tags.
 220                                                                       obj_id,
 221                                                                       oh->type);
 222
 223                                 if (!in)
 224                                         alloc_failed = 1;
 225
 226                                 if (in && oh->shadows_obj > 0) {
 227
 228                                         struct yaffs_shadow_fixer_s *fixer;
 229                                         fixer = YMALLOC(sizeof(struct yaffs_shadow_fixer_s));
 230                                         if (fixer) {
 231                                                 fixer->next = shadowFixerList;
 232                                                 shadowFixerList = fixer;
 233                                                 fixer->obj_id = tags.obj_id;
 234                                                 fixer->shadowed_id = oh->shadows_obj;
 235                                                 T(YAFFS_TRACE_SCAN,
 236                                                   (TSTR
 237                                                    (" Shadow fixer: %d shadows %d" TENDSTR),
 238                                                    fixer->obj_id, fixer->shadowed_id));
 239
 240                                         }
 241
 242                                 }
 243
 244                                 if (in && in->valid) {
 245                                         /* We have already filled this one. We have a duplicate and need to resolve it. */
 246
 247                                         unsigned existingSerial = in->serial;
 248                                         unsigned newSerial = tags.serial_number;
 249
 250                                         if (((existingSerial + 1) & 3) == newSerial) {
 251                                                 /* Use new one - destroy the exisiting one */
 252                                                 yaffs_chunk_del(dev,
 253                                                                   in->hdr_chunk,
 254                                                                   1, __LINE__);
 255                                                 in->valid = 0;
 256                                         } else {
 257                                                 /* Use existing - destroy this one. */
 258                                                 yaffs_chunk_del(dev, chunk, 1,
 259                                                                   __LINE__);
 260                                         }
 261                                 }
 262
 263                                 if (in && !in->valid &&
 264                                     (tags.obj_id == YAFFS_OBJECTID_ROOT ||
 265                                      tags.obj_id == YAFFS_OBJECTID_LOSTNFOUND)) {
 266                                         /* We only load some info, don't fiddle with directory structure */
 267                                         in->valid = 1;
 268                                         in->variant_type = oh->type;
 269
 270                                         in->yst_mode = oh->yst_mode;
 271 #ifdef CONFIG_YAFFS_WINCE
 272                                         in->win_atime[0] = oh->win_atime[0];
 273                                         in->win_ctime[0] = oh->win_ctime[0];
 274                                         in->win_mtime[0] = oh->win_mtime[0];
 275                                         in->win_atime[1] = oh->win_atime[1];
 276                                         in->win_ctime[1] = oh->win_ctime[1];
 277                                         in->win_mtime[1] = oh->win_mtime[1];
 278 #else
 279                                         in->yst_uid = oh->yst_uid;
 280                                         in->yst_gid = oh->yst_gid;
 281                                         in->yst_atime = oh->yst_atime;
 282                                         in->yst_mtime = oh->yst_mtime;
 283                                         in->yst_ctime = oh->yst_ctime;
 284                                         in->yst_rdev = oh->yst_rdev;
 285 #endif
 286                                         in->hdr_chunk = chunk;
 287                                         in->serial = tags.serial_number;
 288
 289                                 } else if (in && !in->valid) {
 290                                         /* we need to load this info */
 291
 292                                         in->valid = 1;
 293                                         in->variant_type = oh->type;
 294
 295                                         in->yst_mode = oh->yst_mode;
 296 #ifdef CONFIG_YAFFS_WINCE
 297                                         in->win_atime[0] = oh->win_atime[0];
 298                                         in->win_ctime[0] = oh->win_ctime[0];
 299                                         in->win_mtime[0] = oh->win_mtime[0];
 300                                         in->win_atime[1] = oh->win_atime[1];
 301                                         in->win_ctime[1] = oh->win_ctime[1];
 302                                         in->win_mtime[1] = oh->win_mtime[1];
 303 #else
 304                                         in->yst_uid = oh->yst_uid;
 305                                         in->yst_gid = oh->yst_gid;
 306                                         in->yst_atime = oh->yst_atime;
 307                                         in->yst_mtime = oh->yst_mtime;
 308                                         in->yst_ctime = oh->yst_ctime;
 309                                         in->yst_rdev = oh->yst_rdev;
 310 #endif
 311                                         in->hdr_chunk = chunk;
 312                                         in->serial = tags.serial_number;
 313
 314                                         yaffs_set_obj_name_from_oh(in, oh);
 315                                         in->dirty = 0;
 316
 317                                         /* directory stuff...
 318                                          * hook up to parent
 319                                          */
 320
 321                                         parent =
 322                                             yaffs_find_or_create_by_number
 323                                             (dev, oh->parent_obj_id,
 324                                              YAFFS_OBJECT_TYPE_DIRECTORY);
 325                                         if (!parent)
 326                                                 alloc_failed = 1;
 327                                         if (parent && parent->variant_type ==
 328                                             YAFFS_OBJECT_TYPE_UNKNOWN) {
 329                                                 /* Set up as a directory */
 330                                                 parent->variant_type =
 331                                                         YAFFS_OBJECT_TYPE_DIRECTORY;
 332                                                 YINIT_LIST_HEAD(&parent->variant.
 333                                                                 dir_variant.
 334                                                                 children);
 335                                         } else if (!parent || parent->variant_type !=
 336                                                    YAFFS_OBJECT_TYPE_DIRECTORY) {
 337                                                 /* Hoosterman, another problem....
 338                                                  * We're trying to use a non-directory as a directory
 339                                                  */
 340
 341                                                 T(YAFFS_TRACE_ERROR,
 342                                                   (TSTR
 343                                                    ("yaffs tragedy: attempting to use non-directory as a directory in scan. Put in lost+found."
 344                                                     TENDSTR)));
 345                                                 parent = dev->lost_n_found;
 346                                         }
 347
 348                                         yaffs_add_obj_to_dir(parent, in);
 349
 350                                         if (0 && (parent == dev->del_dir ||
 351                                                   parent == dev->unlinked_dir)) {
 352                                                 in->deleted = 1;        /* If it is unlinked at start up then it wants deleting */
 353                                                 dev->n_deleted_files++;
 354                                         }
 355                                         /* Note re hardlinks.
 356                                          * Since we might scan a hardlink before its equivalent object is scanned
 357                                          * we put them all in a list.
 358                                          * After scanning is complete, we should have all the objects, so we run through this
 359                                          * list and fix up all the chains.
 360                                          */
 361
 362                                         switch (in->variant_type) {
 363                                         case YAFFS_OBJECT_TYPE_UNKNOWN:
 364                                                 /* Todo got a problem */
 365                                                 break;
 366                                         case YAFFS_OBJECT_TYPE_FILE:
 367                                                 if (dev->param.use_header_file_size)
 368
 369                                                         in->variant.file_variant.
 370                                                             file_size =
 371                                                             oh->file_size;
 372
 373                                                 break;
 374                                         case YAFFS_OBJECT_TYPE_HARDLINK:
 375                                                 in->variant.hardlink_variant.
 376                                                         equiv_id =
 377                                                         oh->equiv_id;
 378                                                 in->hard_links.next =
 379                                                         (struct ylist_head *)
 380                                                         hard_list;
 381                                                 hard_list = in;
 382                                                 break;
 383                                         case YAFFS_OBJECT_TYPE_DIRECTORY:
 384                                                 /* Do nothing */
 385                                                 break;
 386                                         case YAFFS_OBJECT_TYPE_SPECIAL:
 387                                                 /* Do nothing */
 388                                                 break;
 389                                         case YAFFS_OBJECT_TYPE_SYMLINK:
 390                                                 in->variant.symlink_variant.alias =
 391                                                     yaffs_clone_str(oh->alias);
 392                                                 if (!in->variant.symlink_variant.alias)
 393                                                         alloc_failed = 1;
 394                                                 break;
 395                                         }
 396
 397                                 }
 398                         }
 399                 }
 400
 401                 if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
 402                         /* If we got this far while scanning, then the block is fully allocated.*/
 403                         state = YAFFS_BLOCK_STATE_FULL;
 404                 }
 405
 406                 if (state == YAFFS_BLOCK_STATE_ALLOCATING) {
 407                         /* If the block was partially allocated then treat it as fully allocated.*/
 408                         state = YAFFS_BLOCK_STATE_FULL;
 409                         dev->alloc_block = -1;
 410                 }
 411
 412                 bi->block_state = state;
 413
 414                 /* Now let's see if it was dirty */
 415                 if (bi->pages_in_use == 0 &&
 416                     !bi->has_shrink_hdr &&
 417                     bi->block_state == YAFFS_BLOCK_STATE_FULL) {
 418                         yaffs_block_became_dirty(dev, blk);
 419                 }
 420
 421         }
 422
 423
 424         /* Ok, we've done all the scanning.
 425          * Fix up the hard link chains.
 426          * We should now have scanned all the objects, now it's time to add these
 427          * hardlinks.
 428          */
 429
 430         yaffs_link_fixup(dev, hard_list);
 431
 432         /* Fix up any shadowed objects */
 433         {
 434                 struct yaffs_shadow_fixer_s *fixer;
 435                 yaffs_obj_t *obj;
 436
 437                 while (shadowFixerList) {
 438                         fixer = shadowFixerList;
 439                         shadowFixerList = fixer->next;
 440                         /* Complete the rename transaction by deleting the shadowed object
 441                          * then setting the object header to unshadowed.
 442                          */
 443                         obj = yaffs_find_by_number(dev, fixer->shadowed_id);
 444                         if (obj)
 445                                 yaffs_del_obj(obj);
 446
 447                         obj = yaffs_find_by_number(dev, fixer->obj_id);
 448
 449                         if (obj)
 450                                 yaffs_update_oh(obj, NULL, 1, 0, 0, NULL);
 451
 452                         YFREE(fixer);
 453                 }
 454         }
 455
 456         yaffs_release_temp_buffer(dev, chunkData, __LINE__);
 457
 458         if (alloc_failed)
 459                 return YAFFS_FAIL;
 460
 461         T(YAFFS_TRACE_SCAN, (TSTR("yaffs1_scan ends" TENDSTR)));
 462
 463
 464         return YAFFS_OK;
 465 }
 466