yaffs_yaffs1.c

   1 /*
   2  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
   3  *
   4  * Copyright (C) 2002-2018 Aleph One Ltd.
   5  *
   6  * Created by Charles Manning <charles@aleph1.co.uk>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  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 #include "yaffs_attribs.h"
  20
  21 int yaffs1_scan(struct yaffs_dev *dev)
  22 {
  23 #ifdef CONFIG_YAFFS_NO_YAFFS1
  24         return YAFFS_FAIL;
  25 #else
  26         struct yaffs_ext_tags tags;
  27         u32 blk;
  28         int result;
  29         int chunk;
  30         u32 c;
  31         int deleted;
  32         enum yaffs_block_state state;
  33         LIST_HEAD(hard_list);
  34         struct yaffs_block_info *bi;
  35         u32 seq_number;
  36         struct yaffs_obj_hdr *oh;
  37         struct yaffs_obj *in;
  38         struct yaffs_obj *parent;
  39         int alloc_failed = 0;
  40         struct yaffs_shadow_fixer *shadow_fixers = NULL;
  41         u8 *chunk_data;
  42
  43         yaffs_trace(YAFFS_TRACE_SCAN,
  44                 "yaffs1_scan starts  intstartblk %d intendblk %d...",
  45                 dev->internal_start_block, dev->internal_end_block);
  46
  47         chunk_data = yaffs_get_temp_buffer(dev);
  48
  49         dev->seq_number = YAFFS_LOWEST_SEQUENCE_NUMBER;
  50
  51         /* Scan all the blocks to determine their state */
  52         bi = dev->block_info;
  53         for (blk = dev->internal_start_block; blk <= dev->internal_end_block;
  54              blk++) {
  55                 yaffs_clear_chunk_bits(dev, blk);
  56                 bi->pages_in_use = 0;
  57                 bi->soft_del_pages = 0;
  58
  59                 yaffs_query_init_block_state(dev, blk, &state, &seq_number);
  60
  61                 bi->block_state = state;
  62                 bi->seq_number = seq_number;
  63
  64                 if (bi->seq_number == YAFFS_SEQUENCE_BAD_BLOCK)
  65                         bi->block_state = state = YAFFS_BLOCK_STATE_DEAD;
  66
  67                 yaffs_trace(YAFFS_TRACE_SCAN_DEBUG,
  68                         "Block scanning block %d state %d seq %d",
  69                         blk, state, seq_number);
  70
  71                 if (state == YAFFS_BLOCK_STATE_DEAD) {
  72                         yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
  73                                 "block %d is bad", blk);
  74                 } else if (state == YAFFS_BLOCK_STATE_EMPTY) {
  75                         yaffs_trace(YAFFS_TRACE_SCAN_DEBUG, "Block empty ");
  76                         dev->n_erased_blocks++;
  77                         dev->n_free_chunks += dev->param.chunks_per_block;
  78                 }
  79                 bi++;
  80         }
  81
  82         /* For each block.... */
  83         for (blk = dev->internal_start_block;
  84              !alloc_failed && blk <= dev->internal_end_block; blk++) {
  85
  86                 cond_resched();
  87
  88                 bi = yaffs_get_block_info(dev, blk);
  89                 state = bi->block_state;
  90
  91                 deleted = 0;
  92
  93                 /* For each chunk in each block that needs scanning.... */
  94                 for (c = 0;
  95                         !alloc_failed && c < dev->param.chunks_per_block &&
  96                         state == YAFFS_BLOCK_STATE_NEEDS_SCAN; c++) {
  97                         /* Read the tags and decide what to do */
  98                         chunk = blk * dev->param.chunks_per_block + c;
  99
 100                         result = yaffs_rd_chunk_tags_nand(dev, chunk, NULL,
 101                                                           &tags);
 102
 103                         if (result != YAFFS_OK)
 104                                 continue;
 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                         } else if (!tags.chunk_used) {
 115                                 /* An unassigned chunk in the block
 116                                  * This means that either the block is empty or
 117                                  * this is the one being allocated from
 118                                  */
 119
 120                                 if (c == 0) {
 121                                         /* We're looking at the first chunk in
 122                                          *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 */
 127                                         yaffs_trace(YAFFS_TRACE_SCAN,
 128                                                 " Allocating from %d %d",
 129                                                 blk, c);
 130                                         state = YAFFS_BLOCK_STATE_ALLOCATING;
 131                                         dev->alloc_block = blk;
 132                                         dev->alloc_page = c;
 133                                         dev->alloc_block_finder = blk;
 134
 135                                 }
 136
 137                                 dev->n_free_chunks +=
 138                                     (dev->param.chunks_per_block - c);
 139                         } else if (tags.chunk_id > 0) {
 140                                 /* chunk_id > 0 so it is a data chunk... */
 141                                 unsigned int endpos;
 142
 143                                 yaffs_set_chunk_bit(dev, blk, c);
 144                                 bi->pages_in_use++;
 145
 146                                 in = yaffs_find_or_create_by_number(dev,
 147                                                         tags.obj_id,
 148                                                         YAFFS_OBJECT_TYPE_FILE);
 149                                 /* PutChunkIntoFile checks for a clash
 150                                  * (two data chunks with the same chunk_id).
 151                                  */
 152
 153                                 if (!in)
 154                                         alloc_failed = 1;
 155
 156                                 if (in) {
 157                                         if (!yaffs_put_chunk_in_file
 158                                             (in, tags.chunk_id, chunk, 1))
 159                                                 alloc_failed = 1;
 160                                 }
 161
 162                                 endpos =
 163                                     (tags.chunk_id - 1) *
 164                                     dev->data_bytes_per_chunk +
 165                                     tags.n_bytes;
 166                                 if (in &&
 167                                     in->variant_type ==
 168                                      YAFFS_OBJECT_TYPE_FILE &&
 169                                     in->variant.file_variant.stored_size <
 170                                       endpos) {
 171                                         in->variant.file_variant.stored_size =
 172                                             endpos;
 173                                         if (!dev->param.use_header_file_size) {
 174                                                 in->variant.
 175                                                     file_variant.file_size =
 176                                                     in->variant.
 177                                                     file_variant.stored_size;
 178                                         }
 179
 180                                 }
 181                         } else {
 182                                 /* chunk_id == 0, so it is an ObjectHeader.
 183                                  * Make the object
 184                                  */
 185                                 yaffs_set_chunk_bit(dev, blk, c);
 186                                 bi->pages_in_use++;
 187
 188                                 result = yaffs_rd_chunk_tags_nand(dev, chunk,
 189                                                                   chunk_data,
 190                                                                   NULL);
 191
 192                                 oh = (struct yaffs_obj_hdr *)chunk_data;
 193
 194                                 in = yaffs_find_by_number(dev, tags.obj_id);
 195                                 if (in && in->variant_type != oh->type) {
 196                                         /* This should not happen, but somehow
 197                                          * Wev'e ended up with an obj_id that
 198                                          * has been reused but not yet deleted,
 199                                          * and worse still it has changed type.
 200                                          * Delete the old object.
 201                                          */
 202
 203                                         yaffs_del_obj(in);
 204                                         in = NULL;
 205                                 }
 206
 207                                 in = yaffs_find_or_create_by_number(dev,
 208                                                                 tags.obj_id,
 209                                                                 oh->type);
 210
 211                                 if (!in)
 212                                         alloc_failed = 1;
 213
 214                                 if (in && oh->shadows_obj > 0) {
 215
 216                                         struct yaffs_shadow_fixer *fixer;
 217                                         fixer =
 218                                                 kmalloc(sizeof
 219                                                 (struct yaffs_shadow_fixer),
 220                                                 GFP_NOFS);
 221                                         if (fixer) {
 222                                                 fixer->next = shadow_fixers;
 223                                                 shadow_fixers = fixer;
 224                                                 fixer->obj_id = tags.obj_id;
 225                                                 fixer->shadowed_id =
 226                                                     oh->shadows_obj;
 227                                                 yaffs_trace(YAFFS_TRACE_SCAN,
 228                                                         " Shadow fixer: %d shadows %d",
 229                                                         fixer->obj_id,
 230                                                         fixer->shadowed_id);
 231
 232                                         }
 233
 234                                 }
 235
 236                                 if (in && in->valid) {
 237                                         /* We have already filled this one.
 238                                          * We have a duplicate and need to
 239                                          * resolve it. */
 240
 241                                         unsigned existing_serial = in->serial;
 242                                         unsigned new_serial =
 243                                             tags.serial_number;
 244
 245                                         if (((existing_serial + 1) & 3) ==
 246                                             new_serial) {
 247                                                 /* Use new one - destroy the
 248                                                  * exisiting one */
 249                                                 yaffs_chunk_del(dev,
 250                                                                 in->hdr_chunk,
 251                                                                 1, __LINE__);
 252                                                 in->valid = 0;
 253                                         } else {
 254                                                 /* Use existing - destroy
 255                                                  * this one. */
 256                                                 yaffs_chunk_del(dev, chunk, 1,
 257                                                                 __LINE__);
 258                                         }
 259                                 }
 260
 261                                 if (in && !in->valid &&
 262                                     (tags.obj_id == YAFFS_OBJECTID_ROOT ||
 263                                      tags.obj_id ==
 264                                      YAFFS_OBJECTID_LOSTNFOUND)) {
 265                                         /* We only load some info, don't fiddle
 266                                          * with directory structure */
 267                                         in->valid = 1;
 268                                         in->variant_type = oh->type;
 269
 270                                         in->yst_mode = oh->yst_mode;
 271                                         yaffs_load_attribs(in, oh);
 272                                         in->hdr_chunk = chunk;
 273                                         in->serial = tags.serial_number;
 274
 275                                 } else if (in && !in->valid) {
 276                                         /* we need to load this info */
 277
 278                                         in->valid = 1;
 279                                         in->variant_type = oh->type;
 280
 281                                         in->yst_mode = oh->yst_mode;
 282                                         yaffs_load_attribs(in, oh);
 283                                         in->hdr_chunk = chunk;
 284                                         in->serial = tags.serial_number;
 285
 286                                         yaffs_set_obj_name_from_oh(in, oh);
 287                                         in->dirty = 0;
 288
 289                                         /* directory stuff...
 290                                          * hook up to parent
 291                                          */
 292
 293                                         parent =
 294                                             yaffs_find_or_create_by_number
 295                                             (dev, oh->parent_obj_id,
 296                                              YAFFS_OBJECT_TYPE_DIRECTORY);
 297                                         if (!parent)
 298                                                 alloc_failed = 1;
 299                                         if (parent && parent->variant_type ==
 300                                             YAFFS_OBJECT_TYPE_UNKNOWN) {
 301                                                 /* Set up as a directory */
 302                                                 parent->variant_type =
 303                                                     YAFFS_OBJECT_TYPE_DIRECTORY;
 304                                                 INIT_LIST_HEAD(&parent->
 305                                                         variant.dir_variant.
 306                                                         children);
 307                                         } else if (!parent ||
 308                                                 parent->variant_type !=
 309                                                 YAFFS_OBJECT_TYPE_DIRECTORY) {
 310                                                 /* Hoosterman, a problem....
 311                                                  * We're trying to use a
 312                                                  * non-directory as a directory
 313                                                  */
 314
 315                                                 yaffs_trace(YAFFS_TRACE_ERROR,
 316                                                         "yaffs tragedy: attempting to use non-directory as a directory in scan. Put in lost+found."
 317                                                         );
 318                                                 parent = dev->lost_n_found;
 319                                         }
 320
 321                                         yaffs_add_obj_to_dir(parent, in);
 322
 323                                         switch (in->variant_type) {
 324                                         case YAFFS_OBJECT_TYPE_UNKNOWN:
 325                                                 /* Todo got a problem */
 326                                                 break;
 327                                         case YAFFS_OBJECT_TYPE_FILE:
 328                                                 if (dev->param.
 329                                                     use_header_file_size)
 330                                                         in->variant.
 331                                                         file_variant.file_size
 332                                                         = yaffs_oh_to_size(dev, oh, 0);
 333                                                 break;
 334                                         case YAFFS_OBJECT_TYPE_HARDLINK:
 335                                                 in->variant.
 336                                                     hardlink_variant.equiv_id =
 337                                                     oh->equiv_id;
 338                                                 list_add(&in->hard_links,
 339                                                                 &hard_list);
 340                                                 break;
 341                                         case YAFFS_OBJECT_TYPE_DIRECTORY:
 342                                                 /* Do nothing */
 343                                                 break;
 344                                         case YAFFS_OBJECT_TYPE_SPECIAL:
 345                                                 /* Do nothing */
 346                                                 break;
 347                                         case YAFFS_OBJECT_TYPE_SYMLINK:
 348                                                 in->variant.symlink_variant.
 349                                                     alias =
 350                                                     yaffs_clone_str(oh->alias);
 351                                                 if (!in->variant.
 352                                                     symlink_variant.alias)
 353                                                         alloc_failed = 1;
 354                                                 break;
 355                                         }
 356                                 }
 357                         }
 358                 }
 359
 360                 if (state == YAFFS_BLOCK_STATE_NEEDS_SCAN) {
 361                         /* If we got this far while scanning,
 362                          * then the block is fully allocated. */
 363                         state = YAFFS_BLOCK_STATE_FULL;
 364                 }
 365
 366                 if (state == YAFFS_BLOCK_STATE_ALLOCATING) {
 367                         /* If the block was partially allocated then
 368                          * treat it as fully allocated. */
 369                         state = YAFFS_BLOCK_STATE_FULL;
 370                         dev->alloc_block = -1;
 371                 }
 372
 373                 bi->block_state = state;
 374
 375                 /* Now let's see if it was dirty */
 376                 if (bi->pages_in_use == 0 &&
 377                     !bi->has_shrink_hdr &&
 378                     bi->block_state == YAFFS_BLOCK_STATE_FULL)
 379                         yaffs_block_became_dirty(dev, blk);
 380         }
 381
 382         /* Ok, we've done all the scanning.
 383          * Fix up the hard link chains.
 384          * We should now have scanned all the objects, now it's time to add
 385          * these hardlinks.
 386          */
 387
 388         yaffs_link_fixup(dev, &hard_list);
 389
 390         /*
 391          * Fix up any shadowed objects.
 392          * There should not be more than one of these.
 393          */
 394         {
 395                 struct yaffs_shadow_fixer *fixer;
 396                 struct yaffs_obj *obj;
 397
 398                 while (shadow_fixers) {
 399                         fixer = shadow_fixers;
 400                         shadow_fixers = fixer->next;
 401                         /* Complete the rename transaction by deleting the
 402                          * shadowed object then setting the object header
 403                          to unshadowed.
 404                          */
 405                         obj = yaffs_find_by_number(dev, fixer->shadowed_id);
 406                         if (obj)
 407                                 yaffs_del_obj(obj);
 408
 409                         obj = yaffs_find_by_number(dev, fixer->obj_id);
 410
 411                         if (obj)
 412                                 yaffs_update_oh(obj, NULL, 1, 0, 0, NULL);
 413
 414                         kfree(fixer);
 415                 }
 416         }
 417
 418         yaffs_release_temp_buffer(dev, chunk_data);
 419
 420         if (alloc_failed)
 421                 return YAFFS_FAIL;
 422
 423         yaffs_trace(YAFFS_TRACE_SCAN, "yaffs1_scan ends");
 424
 425         return YAFFS_OK;
 426 #endif
 427 }