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 #include "yaffs_attribs.h"
  21
  22 int yaffs1_scan(struct yaffs_dev *dev)
  23 {
  24         struct yaffs_ext_tags tags;
  25         int blk;
  26         int result;
  27
  28         int chunk;
  29         int c;
  30         int deleted;
  31         enum yaffs_block_state state;
  32         struct yaffs_obj *hard_list = NULL;
  33         struct yaffs_block_info *bi;
  34         u32 seq_number;
  35         struct yaffs_obj_hdr *oh;
  36         struct yaffs_obj *in;
  37         struct yaffs_obj *parent;
  38
  39         int alloc_failed = 0;
  40
  41         struct yaffs_shadow_fixer *shadow_fixers = NULL;
  42
  43         u8 *chunk_data;
  44
  45         T(YAFFS_TRACE_SCAN,
  46           (TSTR("yaffs1_scan starts  intstartblk %d intendblk %d..." TENDSTR),
  47            dev->internal_start_block, dev->internal_end_block));
  48
  49         chunk_data = yaffs_get_temp_buffer(dev, __LINE__);
  50
  51         dev->seq_number = YAFFS_LOWEST_SEQUENCE_NUMBER;
  52
  53         /* Scan all the blocks to determine their state */
  54         bi = dev->block_info;
  55         for (blk = dev->internal_start_block; blk <= dev->internal_end_block;
  56              blk++) {
  57                 yaffs_clear_chunk_bits(dev, blk);
  58                 bi->pages_in_use = 0;
  59                 bi->soft_del_pages = 0;
  60
  61                 yaffs_query_init_block_state(dev, blk, &state, &seq_number);
  62
  63                 bi->block_state = state;
  64                 bi->seq_number = seq_number;
  65
  66                 if (bi->seq_number == YAFFS_SEQUENCE_BAD_BLOCK)
  67                         bi->block_state = state = YAFFS_BLOCK_STATE_DEAD;
  68
  69                 T(YAFFS_TRACE_SCAN_DEBUG,
  70                   (TSTR("Block scanning block %d state %d seq %d" TENDSTR), blk,
  71                    state, seq_number));
  72
  73                 if (state == YAFFS_BLOCK_STATE_DEAD) {
  74                         T(YAFFS_TRACE_BAD_BLOCKS,
  75                           (TSTR("block %d is bad" TENDSTR), blk));
  76                 } else if (state == YAFFS_BLOCK_STATE_EMPTY) {
  77                         T(YAFFS_TRACE_SCAN_DEBUG,
  78                           (TSTR("Block empty " TENDSTR)));
  79                         dev->n_erased_blocks++;
  80                         dev->n_free_chunks += dev->param.chunks_per_block;
  81                 }
  82                 bi++;
  83         }
  84
  85         /* For each block.... */
  86         for (blk = dev->internal_start_block;
  87              !alloc_failed && blk <= dev->internal_end_block; blk++) {
  88
  89                 YYIELD();
  90
  91                 bi = yaffs_get_block_info(dev, blk);
  92                 state = bi->block_state;
  93
  94                 deleted = 0;
  95
  96                 /* For each chunk in each block that needs scanning.... */
  97                 for (c = 0; !alloc_failed && c < dev->param.chunks_per_block &&
  98                      state == YAFFS_BLOCK_STATE_NEEDS_SCANNING; c++) {
  99                         /* Read the tags and decide what to do */
 100                         chunk = blk * dev->param.chunks_per_block + c;
 101
 102                         result = yaffs_rd_chunk_tags_nand(dev, chunk, NULL,
 103                                                           &tags);
 104
 105                         /* Let's have a good look at this chunk... */
 106
 107                         if (tags.ecc_result == YAFFS_ECC_RESULT_UNFIXED
 108                             || tags.is_deleted) {
 109                                 /* YAFFS1 only...
 110                                  * A deleted chunk
 111                                  */
 112                                 deleted++;
 113                                 dev->n_free_chunks++;
 114                                 /*T((" %d %d deleted\n",blk,c)); */
 115                         } else if (!tags.chunk_used) {
 116                                 /* An unassigned chunk in the block
 117                                  * This means that either the block is empty or
 118                                  * this is the one being allocated from
 119                                  */
 120
 121                                 if (c == 0) {
 122                                         /* We're looking at the first chunk in the block so the block is unused */
 123                                         state = YAFFS_BLOCK_STATE_EMPTY;
 124                                         dev->n_erased_blocks++;
 125                                 } else {
 126                                         /* this is the block being allocated from */
 127                                         T(YAFFS_TRACE_SCAN,
 128                                           (TSTR
 129                                            (" Allocating from %d %d" TENDSTR),
 130                                            blk, c));
 131                                         state = YAFFS_BLOCK_STATE_ALLOCATING;
 132                                         dev->alloc_block = blk;
 133                                         dev->alloc_page = c;
 134                                         dev->alloc_block_finder = blk;
 135                                         /* Set block finder here to encourage the allocator to go forth from here. */
 136
 137                                 }
 138
 139                                 dev->n_free_chunks +=
 140                                     (dev->param.chunks_per_block - c);
 141                         } else if (tags.chunk_id > 0) {
 142                                 /* chunk_id > 0 so it is a data chunk... */
 143                                 unsigned int endpos;
 144
 145                                 yaffs_set_chunk_bit(dev, blk, c);
 146                                 bi->pages_in_use++;
 147
 148                                 in = yaffs_find_or_create_by_number(dev,
 149                                                                     tags.obj_id,
 150                                                                     YAFFS_OBJECT_TYPE_FILE);
 151                                 /* PutChunkIntoFile checks for a clash (two data chunks with
 152                                  * the same chunk_id).
 153                                  */
 154
 155                                 if (!in)
 156                                         alloc_failed = 1;
 157
 158                                 if (in) {
 159                                         if (!yaffs_put_chunk_in_file
 160                                             (in, tags.chunk_id, chunk, 1))
 161                                                 alloc_failed = 1;
 162                                 }
 163
 164                                 endpos =
 165                                     (tags.chunk_id -
 166                                      1) * dev->data_bytes_per_chunk +
 167                                     tags.n_bytes;
 168                                 if (in
 169                                     && in->variant_type ==
 170                                     YAFFS_OBJECT_TYPE_FILE
 171                                     && in->variant.file_variant.scanned_size <
 172                                     endpos) {
 173                                         in->variant.file_variant.scanned_size =
 174                                             endpos;
 175                                         if (!dev->param.use_header_file_size) {
 176                                                 in->variant.
 177                                                     file_variant.file_size =
 178                                                     in->variant.
 179                                                     file_variant.scanned_size;
 180                                         }
 181
 182                                 }
 183                                 /* T((" %d %d data %d %d\n",blk,c,tags.obj_id,tags.chunk_id));   */
 184                         } else {
 185                                 /* chunk_id == 0, so it is an ObjectHeader.
 186                                  * Thus, we read in the object header and make the object
 187                                  */
 188                                 yaffs_set_chunk_bit(dev, blk, c);
 189                                 bi->pages_in_use++;
 190
 191                                 result = yaffs_rd_chunk_tags_nand(dev, chunk,
 192                                                                   chunk_data,
 193                                                                   NULL);
 194
 195                                 oh = (struct yaffs_obj_hdr *)chunk_data;
 196
 197                                 in = yaffs_find_by_number(dev, tags.obj_id);
 198                                 if (in && in->variant_type != oh->type) {
 199                                         /* This should not happen, but somehow
 200                                          * Wev'e ended up with an obj_id that has been reused but not yet
 201                                          * deleted, and worse still it has changed type. Delete the old object.
 202                                          */
 203
 204                                         yaffs_del_obj(in);
 205
 206                                         in = 0;
 207                                 }
 208
 209                                 in = yaffs_find_or_create_by_number(dev,
 210                                                                     tags.obj_id,
 211                                                                     oh->type);
 212
 213                                 if (!in)
 214                                         alloc_failed = 1;
 215
 216                                 if (in && oh->shadows_obj > 0) {
 217
 218                                         struct yaffs_shadow_fixer *fixer;
 219                                         fixer =
 220                                             YMALLOC(sizeof
 221                                                     (struct
 222                                                      yaffs_shadow_fixer));
 223                                         if (fixer) {
 224                                                 fixer->next = shadow_fixers;
 225                                                 shadow_fixers = fixer;
 226                                                 fixer->obj_id = tags.obj_id;
 227                                                 fixer->shadowed_id =
 228                                                     oh->shadows_obj;
 229                                                 T(YAFFS_TRACE_SCAN,
 230                                                   (TSTR
 231                                                    (" Shadow fixer: %d shadows %d"
 232                                                     TENDSTR), fixer->obj_id,
 233                                                    fixer->shadowed_id));
 234
 235                                         }
 236
 237                                 }
 238
 239                                 if (in && in->valid) {
 240                                         /* We have already filled this one. We have a duplicate and need to resolve it. */
 241
 242                                         unsigned existing_serial = in->serial;
 243                                         unsigned new_serial =
 244                                             tags.serial_number;
 245
 246                                         if (((existing_serial + 1) & 3) ==
 247                                             new_serial) {
 248                                                 /* Use new one - destroy the exisiting one */
 249                                                 yaffs_chunk_del(dev,
 250                                                                 in->hdr_chunk,
 251                                                                 1, __LINE__);
 252                                                 in->valid = 0;
 253                                         } else {
 254                                                 /* Use existing - destroy this one. */
 255                                                 yaffs_chunk_del(dev, chunk, 1,
 256                                                                 __LINE__);
 257                                         }
 258                                 }
 259
 260                                 if (in && !in->valid &&
 261                                     (tags.obj_id == YAFFS_OBJECTID_ROOT ||
 262                                      tags.obj_id ==
 263                                      YAFFS_OBJECTID_LOSTNFOUND)) {
 264                                         /* We only load some info, don't fiddle with directory structure */
 265                                         in->valid = 1;
 266                                         in->variant_type = oh->type;
 267
 268                                         in->yst_mode = oh->yst_mode;
 269                                         yaffs_load_attribs(in, oh);
 270                                         in->hdr_chunk = chunk;
 271                                         in->serial = tags.serial_number;
 272
 273                                 } else if (in && !in->valid) {
 274                                         /* we need to load this info */
 275
 276                                         in->valid = 1;
 277                                         in->variant_type = oh->type;
 278
 279                                         in->yst_mode = oh->yst_mode;
 280                                         yaffs_load_attribs(in, oh);
 281                                         in->hdr_chunk = chunk;
 282                                         in->serial = tags.serial_number;
 283
 284                                         yaffs_set_obj_name_from_oh(in, oh);
 285                                         in->dirty = 0;
 286
 287                                         /* directory stuff...
 288                                          * hook up to parent
 289                                          */
 290
 291                                         parent =
 292                                             yaffs_find_or_create_by_number
 293                                             (dev, oh->parent_obj_id,
 294                                              YAFFS_OBJECT_TYPE_DIRECTORY);
 295                                         if (!parent)
 296                                                 alloc_failed = 1;
 297                                         if (parent && parent->variant_type ==
 298                                             YAFFS_OBJECT_TYPE_UNKNOWN) {
 299                                                 /* Set up as a directory */
 300                                                 parent->variant_type =
 301                                                     YAFFS_OBJECT_TYPE_DIRECTORY;
 302                                                 INIT_LIST_HEAD(&parent->
 303                                                                variant.dir_variant.children);
 304                                         } else if (!parent
 305                                                    || parent->variant_type !=
 306                                                    YAFFS_OBJECT_TYPE_DIRECTORY) {
 307                                                 /* Hoosterman, another problem....
 308                                                  * We're trying to use a non-directory as a directory
 309                                                  */
 310
 311                                                 T(YAFFS_TRACE_ERROR,
 312                                                   (TSTR
 313                                                    ("yaffs tragedy: attempting to use non-directory as a directory in scan. Put in lost+found."
 314                                                     TENDSTR)));
 315                                                 parent = dev->lost_n_found;
 316                                         }
 317
 318                                         yaffs_add_obj_to_dir(parent, in);
 319
 320                                         if (0 && (parent == dev->del_dir ||
 321                                                   parent ==
 322                                                   dev->unlinked_dir)) {
 323                                                 in->deleted = 1;        /* If it is unlinked at start up then it wants deleting */
 324                                                 dev->n_deleted_files++;
 325                                         }
 326                                         /* Note re hardlinks.
 327                                          * Since we might scan a hardlink before its equivalent object is scanned
 328                                          * we put them all in a list.
 329                                          * After scanning is complete, we should have all the objects, so we run through this
 330                                          * list and fix up all the chains.
 331                                          */
 332
 333                                         switch (in->variant_type) {
 334                                         case YAFFS_OBJECT_TYPE_UNKNOWN:
 335                                                 /* Todo got a problem */
 336                                                 break;
 337                                         case YAFFS_OBJECT_TYPE_FILE:
 338                                                 if (dev->param.
 339                                                     use_header_file_size)
 340
 341                                                         in->variant.
 342                                                             file_variant.file_size
 343                                                             = oh->file_size;
 344
 345                                                 break;
 346                                         case YAFFS_OBJECT_TYPE_HARDLINK:
 347                                                 in->variant.
 348                                                     hardlink_variant.equiv_id =
 349                                                     oh->equiv_id;
 350                                                 in->hard_links.next =
 351                                                     (struct list_head *)
 352                                                     hard_list;
 353                                                 hard_list = in;
 354                                                 break;
 355                                         case YAFFS_OBJECT_TYPE_DIRECTORY:
 356                                                 /* Do nothing */
 357                                                 break;
 358                                         case YAFFS_OBJECT_TYPE_SPECIAL:
 359                                                 /* Do nothing */
 360                                                 break;
 361                                         case YAFFS_OBJECT_TYPE_SYMLINK:
 362                                                 in->variant.symlink_variant.
 363                                                     alias =
 364                                                     yaffs_clone_str(oh->alias);
 365                                                 if (!in->variant.
 366                                                     symlink_variant.alias)
 367                                                         alloc_failed = 1;
 368                                                 break;
 369                                         }
 370
 371                                 }
 372                         }
 373                 }
 374
 375                 if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
 376                         /* If we got this far while scanning, then the block is fully allocated. */
 377                         state = YAFFS_BLOCK_STATE_FULL;
 378                 }
 379
 380                 if (state == YAFFS_BLOCK_STATE_ALLOCATING) {
 381                         /* If the block was partially allocated then treat it as fully allocated. */
 382                         state = YAFFS_BLOCK_STATE_FULL;
 383                         dev->alloc_block = -1;
 384                 }
 385
 386                 bi->block_state = state;
 387
 388                 /* Now let's see if it was dirty */
 389                 if (bi->pages_in_use == 0 &&
 390                     !bi->has_shrink_hdr &&
 391                     bi->block_state == YAFFS_BLOCK_STATE_FULL) {
 392                         yaffs_block_became_dirty(dev, blk);
 393                 }
 394
 395         }
 396
 397         /* Ok, we've done all the scanning.
 398          * Fix up the hard link chains.
 399          * We should now have scanned all the objects, now it's time to add these
 400          * hardlinks.
 401          */
 402
 403         yaffs_link_fixup(dev, hard_list);
 404
 405         /* Fix up any shadowed objects */
 406         {
 407                 struct yaffs_shadow_fixer *fixer;
 408                 struct yaffs_obj *obj;
 409
 410                 while (shadow_fixers) {
 411                         fixer = shadow_fixers;
 412                         shadow_fixers = fixer->next;
 413                         /* Complete the rename transaction by deleting the shadowed object
 414                          * then setting the object header to unshadowed.
 415                          */
 416                         obj = yaffs_find_by_number(dev, fixer->shadowed_id);
 417                         if (obj)
 418                                 yaffs_del_obj(obj);
 419
 420                         obj = yaffs_find_by_number(dev, fixer->obj_id);
 421
 422                         if (obj)
 423                                 yaffs_update_oh(obj, NULL, 1, 0, 0, NULL);
 424
 425                         YFREE(fixer);
 426                 }
 427         }
 428
 429         yaffs_release_temp_buffer(dev, chunk_data, __LINE__);
 430
 431         if (alloc_failed)
 432                 return YAFFS_FAIL;
 433
 434         T(YAFFS_TRACE_SCAN, (TSTR("yaffs1_scan ends" TENDSTR)));
 435
 436         return YAFFS_OK;
 437 }