yaffs_yaffs1.c

   1 /*
   2  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
   3  *
   4  * Copyright (C) 2002-2011 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         int chunk;
  28         int c;
  29         int deleted;
  30         enum yaffs_block_state state;
  31         LIST_HEAD(hard_list);
  32         struct yaffs_block_info *bi;
  33         u32 seq_number;
  34         struct yaffs_obj_hdr *oh;
  35         struct yaffs_obj *in;
  36         struct yaffs_obj *parent;
  37         int alloc_failed = 0;
  38         struct yaffs_shadow_fixer *shadow_fixers = NULL;
  39         u8 *chunk_data;
  40
  41         yaffs_trace(YAFFS_TRACE_SCAN,
  42                 "yaffs1_scan starts  intstartblk %d intendblk %d...",
  43                 dev->internal_start_block, dev->internal_end_block);
  44
  45         chunk_data = yaffs_get_temp_buffer(dev);
  46
  47         dev->seq_number = YAFFS_LOWEST_SEQUENCE_NUMBER;
  48
  49         /* Scan all the blocks to determine their state */
  50         bi = dev->block_info;
  51         for (blk = dev->internal_start_block; blk <= dev->internal_end_block;
  52              blk++) {
  53                 yaffs_clear_chunk_bits(dev, blk);
  54                 bi->pages_in_use = 0;
  55                 bi->soft_del_pages = 0;
  56
  57                 yaffs_query_init_block_state(dev, blk, &state, &seq_number);
  58
  59                 bi->block_state = state;
  60                 bi->seq_number = seq_number;
  61
  62                 if (bi->seq_number == YAFFS_SEQUENCE_BAD_BLOCK)
  63                         bi->block_state = state = YAFFS_BLOCK_STATE_DEAD;
  64
  65                 yaffs_trace(YAFFS_TRACE_SCAN_DEBUG,
  66                         "Block scanning block %d state %d seq %d",
  67                         blk, state, seq_number);
  68
  69                 if (state == YAFFS_BLOCK_STATE_DEAD) {
  70                         yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
  71                                 "block %d is bad", blk);
  72                 } else if (state == YAFFS_BLOCK_STATE_EMPTY) {
  73                         yaffs_trace(YAFFS_TRACE_SCAN_DEBUG, "Block empty ");
  74                         dev->n_erased_blocks++;
  75                         dev->n_free_chunks += dev->param.chunks_per_block;
  76                 }
  77                 bi++;
  78         }
  79
  80         /* For each block.... */
  81         for (blk = dev->internal_start_block;
  82              !alloc_failed && blk <= dev->internal_end_block; blk++) {
  83
  84                 cond_resched();
  85
  86                 bi = yaffs_get_block_info(dev, blk);
  87                 state = bi->block_state;
  88
  89                 deleted = 0;
  90
  91                 /* For each chunk in each block that needs scanning.... */
  92                 for (c = 0;
  93                         !alloc_failed && c < dev->param.chunks_per_block &&
  94                         state == YAFFS_BLOCK_STATE_NEEDS_SCAN; c++) {
  95                         /* Read the tags and decide what to do */
  96                         chunk = blk * dev->param.chunks_per_block + c;
  97
  98                         result = yaffs_rd_chunk_tags_nand(dev, chunk, NULL,
  99                                                           &tags);
 100
 101                         /* Let's have a good look at this chunk... */
 102
 103                         if (tags.ecc_result == YAFFS_ECC_RESULT_UNFIXED ||
 104                             tags.is_deleted) {
 105                                 /* YAFFS1 only...
 106                                  * A deleted chunk
 107                                  */
 108                                 deleted++;
 109                                 dev->n_free_chunks++;
 110                         } else if (!tags.chunk_used) {
 111                                 /* An unassigned chunk in the block
 112                                  * This means that either the block is empty or
 113                                  * this is the one being allocated from
 114                                  */
 115
 116                                 if (c == 0) {
 117                                         /* We're looking at the first chunk in
 118                                          *the block so the block is unused */
 119                                         state = YAFFS_BLOCK_STATE_EMPTY;
 120                                         dev->n_erased_blocks++;
 121                                 } else {
 122                                         /* this is the block being allocated */
 123                                         yaffs_trace(YAFFS_TRACE_SCAN,
 124                                                 " Allocating from %d %d",
 125                                                 blk, c);
 126                                         state = YAFFS_BLOCK_STATE_ALLOCATING;
 127                                         dev->alloc_block = blk;
 128                                         dev->alloc_page = c;
 129                                         dev->alloc_block_finder = blk;
 130
 131                                 }
 132
 133                                 dev->n_free_chunks +=
 134                                     (dev->param.chunks_per_block - c);
 135                         } else if (tags.chunk_id > 0) {
 136                                 /* chunk_id > 0 so it is a data chunk... */
 137                                 unsigned int endpos;
 138
 139                                 yaffs_set_chunk_bit(dev, blk, c);
 140                                 bi->pages_in_use++;
 141
 142                                 in = yaffs_find_or_create_by_number(dev,
 143                                                         tags.obj_id,
 144                                                         YAFFS_OBJECT_TYPE_FILE);
 145                                 /* PutChunkIntoFile checks for a clash
 146                                  * (two data chunks with the same chunk_id).
 147                                  */
 148
 149                                 if (!in)
 150                                         alloc_failed = 1;
 151
 152                                 if (in) {
 153                                         if (!yaffs_put_chunk_in_file
 154                                             (in, tags.chunk_id, chunk, 1))
 155                                                 alloc_failed = 1;
 156                                 }
 157
 158                                 endpos =
 159                                     (tags.chunk_id - 1) *
 160                                     dev->data_bytes_per_chunk +
 161                                     tags.n_bytes;
 162                                 if (in &&
 163                                     in->variant_type ==
 164                                      YAFFS_OBJECT_TYPE_FILE &&
 165                                     in->variant.file_variant.scanned_size <
 166                                       endpos) {
 167                                         in->variant.file_variant.scanned_size =
 168                                             endpos;
 169                                         if (!dev->param.use_header_file_size) {
 170                                                 in->variant.
 171                                                     file_variant.file_size =
 172                                                     in->variant.
 173                                                     file_variant.scanned_size;
 174                                         }
 175
 176                                 }
 177                         } else {
 178                                 /* chunk_id == 0, so it is an ObjectHeader.
 179                                  * Make the object
 180                                  */
 181                                 yaffs_set_chunk_bit(dev, blk, c);
 182                                 bi->pages_in_use++;
 183
 184                                 result = yaffs_rd_chunk_tags_nand(dev, chunk,
 185                                                                   chunk_data,
 186                                                                   NULL);
 187
 188                                 oh = (struct yaffs_obj_hdr *)chunk_data;
 189
 190                                 in = yaffs_find_by_number(dev, tags.obj_id);
 191                                 if (in && in->variant_type != oh->type) {
 192                                         /* This should not happen, but somehow
 193                                          * Wev'e ended up with an obj_id that
 194                                          * has been reused but not yet deleted,
 195                                          * and worse still it has changed type.
 196                                          * Delete the old object.
 197                                          */
 198
 199                                         yaffs_del_obj(in);
 200                                         in = NULL;
 201                                 }
 202
 203                                 in = yaffs_find_or_create_by_number(dev,
 204                                                                 tags.obj_id,
 205                                                                 oh->type);
 206
 207                                 if (!in)
 208                                         alloc_failed = 1;
 209
 210                                 if (in && oh->shadows_obj > 0) {
 211
 212                                         struct yaffs_shadow_fixer *fixer;
 213                                         fixer =
 214                                                 kmalloc(sizeof
 215                                                 (struct yaffs_shadow_fixer),
 216                                                 GFP_NOFS);
 217                                         if (fixer) {
 218                                                 fixer->next = shadow_fixers;
 219                                                 shadow_fixers = fixer;
 220                                                 fixer->obj_id = tags.obj_id;
 221                                                 fixer->shadowed_id =
 222                                                     oh->shadows_obj;
 223                                                 yaffs_trace(YAFFS_TRACE_SCAN,
 224                                                         " Shadow fixer: %d shadows %d",
 225                                                         fixer->obj_id,
 226                                                         fixer->shadowed_id);
 227
 228                                         }
 229
 230                                 }
 231
 232                                 if (in && in->valid) {
 233                                         /* We have already filled this one.
 234                                          * We have a duplicate and need to
 235                                          * resolve it. */
 236
 237                                         unsigned existing_serial = in->serial;
 238                                         unsigned new_serial =
 239                                             tags.serial_number;
 240
 241                                         if (((existing_serial + 1) & 3) ==
 242                                             new_serial) {
 243                                                 /* Use new one - destroy the
 244                                                  * exisiting one */
 245                                                 yaffs_chunk_del(dev,
 246                                                                 in->hdr_chunk,
 247                                                                 1, __LINE__);
 248                                                 in->valid = 0;
 249                                         } else {
 250                                                 /* Use existing - destroy
 251                                                  * this one. */
 252                                                 yaffs_chunk_del(dev, chunk, 1,
 253                                                                 __LINE__);
 254                                         }
 255                                 }
 256
 257                                 if (in && !in->valid &&
 258                                     (tags.obj_id == YAFFS_OBJECTID_ROOT ||
 259                                      tags.obj_id ==
 260                                      YAFFS_OBJECTID_LOSTNFOUND)) {
 261                                         /* We only load some info, don't fiddle
 262                                          * with directory structure */
 263                                         in->valid = 1;
 264                                         in->variant_type = oh->type;
 265
 266                                         in->yst_mode = oh->yst_mode;
 267                                         yaffs_load_attribs(in, oh);
 268                                         in->hdr_chunk = chunk;
 269                                         in->serial = tags.serial_number;
 270
 271                                 } else if (in && !in->valid) {
 272                                         /* we need to load this info */
 273
 274                                         in->valid = 1;
 275                                         in->variant_type = oh->type;
 276
 277                                         in->yst_mode = oh->yst_mode;
 278                                         yaffs_load_attribs(in, oh);
 279                                         in->hdr_chunk = chunk;
 280                                         in->serial = tags.serial_number;
 281
 282                                         yaffs_set_obj_name_from_oh(in, oh);
 283                                         in->dirty = 0;
 284
 285                                         /* directory stuff...
 286                                          * hook up to parent
 287                                          */
 288
 289                                         parent =
 290                                             yaffs_find_or_create_by_number
 291                                             (dev, oh->parent_obj_id,
 292                                              YAFFS_OBJECT_TYPE_DIRECTORY);
 293                                         if (!parent)
 294                                                 alloc_failed = 1;
 295                                         if (parent && parent->variant_type ==
 296                                             YAFFS_OBJECT_TYPE_UNKNOWN) {
 297                                                 /* Set up as a directory */
 298                                                 parent->variant_type =
 299                                                     YAFFS_OBJECT_TYPE_DIRECTORY;
 300                                                 INIT_LIST_HEAD(&parent->
 301                                                         variant.dir_variant.
 302                                                         children);
 303                                         } else if (!parent ||
 304                                                 parent->variant_type !=
 305                                                 YAFFS_OBJECT_TYPE_DIRECTORY) {
 306                                                 /* Hoosterman, a problem....
 307                                                  * We're trying to use a
 308                                                  * non-directory as a directory
 309                                                  */
 310
 311                                                 yaffs_trace(YAFFS_TRACE_ERROR,
 312                                                         "yaffs tragedy: attempting to use non-directory as a directory in scan. Put in lost+found."
 313                                                         );
 314                                                 parent = dev->lost_n_found;
 315                                         }
 316
 317                                         yaffs_add_obj_to_dir(parent, in);
 318
 319                                         switch (in->variant_type) {
 320                                         case YAFFS_OBJECT_TYPE_UNKNOWN:
 321                                                 /* Todo got a problem */
 322                                                 break;
 323                                         case YAFFS_OBJECT_TYPE_FILE:
 324                                                 if (dev->param.
 325                                                     use_header_file_size)
 326                                                         in->variant.
 327                                                         file_variant.file_size
 328                                                         = yaffs_oh_to_size(oh);
 329                                                 break;
 330                                         case YAFFS_OBJECT_TYPE_HARDLINK:
 331                                                 in->variant.
 332                                                     hardlink_variant.equiv_id =
 333                                                     oh->equiv_id;
 334                                                 list_add(&in->hard_links,
 335                                                                 &hard_list);
 336                                                 break;
 337                                         case YAFFS_OBJECT_TYPE_DIRECTORY:
 338                                                 /* Do nothing */
 339                                                 break;
 340                                         case YAFFS_OBJECT_TYPE_SPECIAL:
 341                                                 /* Do nothing */
 342                                                 break;
 343                                         case YAFFS_OBJECT_TYPE_SYMLINK:
 344                                                 in->variant.symlink_variant.
 345                                                     alias =
 346                                                     yaffs_clone_str(oh->alias);
 347                                                 if (!in->variant.
 348                                                     symlink_variant.alias)
 349                                                         alloc_failed = 1;
 350                                                 break;
 351                                         }
 352                                 }
 353                         }
 354                 }
 355
 356                 if (state == YAFFS_BLOCK_STATE_NEEDS_SCAN) {
 357                         /* If we got this far while scanning,
 358                          * then the block is fully allocated. */
 359                         state = YAFFS_BLOCK_STATE_FULL;
 360                 }
 361
 362                 if (state == YAFFS_BLOCK_STATE_ALLOCATING) {
 363                         /* If the block was partially allocated then
 364                          * treat it as fully allocated. */
 365                         state = YAFFS_BLOCK_STATE_FULL;
 366                         dev->alloc_block = -1;
 367                 }
 368
 369                 bi->block_state = state;
 370
 371                 /* Now let's see if it was dirty */
 372                 if (bi->pages_in_use == 0 &&
 373                     !bi->has_shrink_hdr &&
 374                     bi->block_state == YAFFS_BLOCK_STATE_FULL)
 375                         yaffs_block_became_dirty(dev, blk);
 376         }
 377
 378         /* Ok, we've done all the scanning.
 379          * Fix up the hard link chains.
 380          * We should now have scanned all the objects, now it's time to add
 381          * these hardlinks.
 382          */
 383
 384         yaffs_link_fixup(dev, &hard_list);
 385
 386         /*
 387          * Fix up any shadowed objects.
 388          * There should not be more than one of these.
 389          */
 390         {
 391                 struct yaffs_shadow_fixer *fixer;
 392                 struct yaffs_obj *obj;
 393
 394                 while (shadow_fixers) {
 395                         fixer = shadow_fixers;
 396                         shadow_fixers = fixer->next;
 397                         /* Complete the rename transaction by deleting the
 398                          * shadowed object then setting the object header
 399                          to unshadowed.
 400                          */
 401                         obj = yaffs_find_by_number(dev, fixer->shadowed_id);
 402                         if (obj)
 403                                 yaffs_del_obj(obj);
 404
 405                         obj = yaffs_find_by_number(dev, fixer->obj_id);
 406
 407                         if (obj)
 408                                 yaffs_update_oh(obj, NULL, 1, 0, 0, NULL);
 409
 410                         kfree(fixer);
 411                 }
 412         }
 413
 414         yaffs_release_temp_buffer(dev, chunk_data);
 415
 416         if (alloc_failed)
 417                 return YAFFS_FAIL;
 418
 419         yaffs_trace(YAFFS_TRACE_SCAN, "yaffs1_scan ends");
 420
 421         return YAFFS_OK;
 422 }