fs/yaffs2/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 chunk;
  27         int c;
  28         int deleted;
  29         enum yaffs_block_state state;
  30         LIST_HEAD(hard_list);
  31         struct yaffs_block_info *bi;
  32         u32 seq_number;
  33         struct yaffs_obj_hdr *oh;
  34         struct yaffs_obj *in;
  35         struct yaffs_obj *parent;
  36         int alloc_failed = 0;
  37         struct yaffs_shadow_fixer *shadow_fixers = NULL;
  38         u8 *chunk_data;
  39
  40         yaffs_trace(YAFFS_TRACE_SCAN,
  41                 "yaffs1_scan starts  intstartblk %d intendblk %d...",
  42                 dev->internal_start_block, dev->internal_end_block);
  43
  44         chunk_data = yaffs_get_temp_buffer(dev);
  45
  46         dev->seq_number = YAFFS_LOWEST_SEQUENCE_NUMBER;
  47
  48         /* Scan all the blocks to determine their state */
  49         bi = dev->block_info;
  50         for (blk = dev->internal_start_block; blk <= dev->internal_end_block;
  51              blk++) {
  52                 yaffs_clear_chunk_bits(dev, blk);
  53                 bi->pages_in_use = 0;
  54                 bi->soft_del_pages = 0;
  55
  56                 yaffs_query_init_block_state(dev, blk, &state, &seq_number);
  57
  58                 bi->block_state = state;
  59                 bi->seq_number = seq_number;
  60
  61                 if (bi->seq_number == YAFFS_SEQUENCE_BAD_BLOCK)
  62                         bi->block_state = state = YAFFS_BLOCK_STATE_DEAD;
  63
  64                 yaffs_trace(YAFFS_TRACE_SCAN_DEBUG,
  65                         "Block scanning block %d state %d seq %d",
  66                         blk, state, seq_number);
  67
  68                 if (state == YAFFS_BLOCK_STATE_DEAD) {
  69                         yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
  70                                 "block %d is bad", blk);
  71                 } else if (state == YAFFS_BLOCK_STATE_EMPTY) {
  72                         yaffs_trace(YAFFS_TRACE_SCAN_DEBUG, "Block empty ");
  73                         dev->n_erased_blocks++;
  74                         dev->n_free_chunks += dev->param.chunks_per_block;
  75                 }
  76                 bi++;
  77         }
  78
  79         /* For each block.... */
  80         for (blk = dev->internal_start_block;
  81              !alloc_failed && blk <= dev->internal_end_block; blk++) {
  82
  83                 cond_resched();
  84
  85                 bi = yaffs_get_block_info(dev, blk);
  86                 state = bi->block_state;
  87
  88                 deleted = 0;
  89
  90                 /* For each chunk in each block that needs scanning.... */
  91                 for (c = 0;
  92                         !alloc_failed && c < dev->param.chunks_per_block &&
  93                         state == YAFFS_BLOCK_STATE_NEEDS_SCAN; c++) {
  94                         /* Read the tags and decide what to do */
  95                         chunk = blk * dev->param.chunks_per_block + c;
  96
  97                         yaffs_rd_chunk_tags_nand(dev, chunk, NULL, &tags);
  98
  99                         /* Let's have a good look at this chunk... */
 100
 101                         if (tags.ecc_result == YAFFS_ECC_RESULT_UNFIXED ||
 102                             tags.is_deleted) {
 103                                 /* YAFFS1 only...
 104                                  * A deleted chunk
 105                                  */
 106                                 deleted++;
 107                                 dev->n_free_chunks++;
 108                         } else if (!tags.chunk_used) {
 109                                 /* An unassigned chunk in the block
 110                                  * This means that either the block is empty or
 111                                  * this is the one being allocated from
 112                                  */
 113
 114                                 if (c == 0) {
 115                                         /* We're looking at the first chunk in
 116                                          *the block so the block is unused */
 117                                         state = YAFFS_BLOCK_STATE_EMPTY;
 118                                         dev->n_erased_blocks++;
 119                                 } else {
 120                                         /* this is the block being allocated */
 121                                         yaffs_trace(YAFFS_TRACE_SCAN,
 122                                                 " Allocating from %d %d",
 123                                                 blk, c);
 124                                         state = YAFFS_BLOCK_STATE_ALLOCATING;
 125                                         dev->alloc_block = blk;
 126                                         dev->alloc_page = c;
 127                                         dev->alloc_block_finder = blk;
 128
 129                                 }
 130
 131                                 dev->n_free_chunks +=
 132                                     (dev->param.chunks_per_block - c);
 133                         } else if (tags.chunk_id > 0) {
 134                                 /* chunk_id > 0 so it is a data chunk... */
 135                                 unsigned int endpos;
 136
 137                                 yaffs_set_chunk_bit(dev, blk, c);
 138                                 bi->pages_in_use++;
 139
 140                                 in = yaffs_find_or_create_by_number(dev,
 141                                                         tags.obj_id,
 142                                                         YAFFS_OBJECT_TYPE_FILE);
 143                                 /* PutChunkIntoFile checks for a clash
 144                                  * (two data chunks with the same chunk_id).
 145                                  */
 146
 147                                 if (!in)
 148                                         alloc_failed = 1;
 149
 150                                 if (in) {
 151                                         if (!yaffs_put_chunk_in_file
 152                                             (in, tags.chunk_id, chunk, 1))
 153                                                 alloc_failed = 1;
 154                                 }
 155
 156                                 endpos =
 157                                     (tags.chunk_id - 1) *
 158                                     dev->data_bytes_per_chunk +
 159                                     tags.n_bytes;
 160                                 if (in &&
 161                                     in->variant_type ==
 162                                      YAFFS_OBJECT_TYPE_FILE &&
 163                                     in->variant.file_variant.scanned_size <
 164                                       endpos) {
 165                                         in->variant.file_variant.scanned_size =
 166                                             endpos;
 167                                         if (!dev->param.use_header_file_size) {
 168                                                 in->variant.
 169                                                     file_variant.file_size =
 170                                                     in->variant.
 171                                                     file_variant.scanned_size;
 172                                         }
 173
 174                                 }
 175                         } else {
 176                                 /* chunk_id == 0, so it is an ObjectHeader.
 177                                  * Make the object
 178                                  */
 179                                 yaffs_set_chunk_bit(dev, blk, c);
 180                                 bi->pages_in_use++;
 181
 182                                 yaffs_rd_chunk_tags_nand(dev, chunk,
 183                                                          chunk_data, NULL);
 184
 185                                 oh = (struct yaffs_obj_hdr *)chunk_data;
 186
 187                                 in = yaffs_find_by_number(dev, tags.obj_id);
 188                                 if (in && in->variant_type != oh->type) {
 189                                         /* This should not happen, but somehow
 190                                          * Wev'e ended up with an obj_id that
 191                                          * has been reused but not yet deleted,
 192                                          * and worse still it has changed type.
 193                                          * Delete the old object.
 194                                          */
 195
 196                                         yaffs_del_obj(in);
 197                                         in = NULL;
 198                                 }
 199
 200                                 in = yaffs_find_or_create_by_number(dev,
 201                                                                 tags.obj_id,
 202                                                                 oh->type);
 203
 204                                 if (!in)
 205                                         alloc_failed = 1;
 206
 207                                 if (in && oh->shadows_obj > 0) {
 208
 209                                         struct yaffs_shadow_fixer *fixer;
 210                                         fixer =
 211                                                 kmalloc(sizeof
 212                                                 (struct yaffs_shadow_fixer),
 213                                                 GFP_NOFS);
 214                                         if (fixer) {
 215                                                 fixer->next = shadow_fixers;
 216                                                 shadow_fixers = fixer;
 217                                                 fixer->obj_id = tags.obj_id;
 218                                                 fixer->shadowed_id =
 219                                                     oh->shadows_obj;
 220                                                 yaffs_trace(YAFFS_TRACE_SCAN,
 221                                                         " Shadow fixer: %d shadows %d",
 222                                                         fixer->obj_id,
 223                                                         fixer->shadowed_id);
 224
 225                                         }
 226
 227                                 }
 228
 229                                 if (in && in->valid) {
 230                                         /* We have already filled this one.
 231                                          * We have a duplicate and need to
 232                                          * resolve it. */
 233
 234                                         unsigned existing_serial = in->serial;
 235                                         unsigned new_serial =
 236                                             tags.serial_number;
 237
 238                                         if (((existing_serial + 1) & 3) ==
 239                                             new_serial) {
 240                                                 /* Use new one - destroy the
 241                                                  * exisiting one */
 242                                                 yaffs_chunk_del(dev,
 243                                                                 in->hdr_chunk,
 244                                                                 1, __LINE__);
 245                                                 in->valid = 0;
 246                                         } else {
 247                                                 /* Use existing - destroy
 248                                                  * this one. */
 249                                                 yaffs_chunk_del(dev, chunk, 1,
 250                                                                 __LINE__);
 251                                         }
 252                                 }
 253
 254                                 if (in && !in->valid &&
 255                                     (tags.obj_id == YAFFS_OBJECTID_ROOT ||
 256                                      tags.obj_id ==
 257                                      YAFFS_OBJECTID_LOSTNFOUND)) {
 258                                         /* We only load some info, don't fiddle
 259                                          * with directory structure */
 260                                         in->valid = 1;
 261                                         in->variant_type = oh->type;
 262
 263                                         in->yst_mode = oh->yst_mode;
 264                                         yaffs_load_attribs(in, oh);
 265                                         in->hdr_chunk = chunk;
 266                                         in->serial = tags.serial_number;
 267
 268                                 } else if (in && !in->valid) {
 269                                         /* we need to load this info */
 270
 271                                         in->valid = 1;
 272                                         in->variant_type = oh->type;
 273
 274                                         in->yst_mode = oh->yst_mode;
 275                                         yaffs_load_attribs(in, oh);
 276                                         in->hdr_chunk = chunk;
 277                                         in->serial = tags.serial_number;
 278
 279                                         yaffs_set_obj_name_from_oh(in, oh);
 280                                         in->dirty = 0;
 281
 282                                         /* directory stuff...
 283                                          * hook up to parent
 284                                          */
 285
 286                                         parent =
 287                                             yaffs_find_or_create_by_number
 288                                             (dev, oh->parent_obj_id,
 289                                              YAFFS_OBJECT_TYPE_DIRECTORY);
 290                                         if (!parent)
 291                                                 alloc_failed = 1;
 292                                         if (parent && parent->variant_type ==
 293                                             YAFFS_OBJECT_TYPE_UNKNOWN) {
 294                                                 /* Set up as a directory */
 295                                                 parent->variant_type =
 296                                                     YAFFS_OBJECT_TYPE_DIRECTORY;
 297                                                 INIT_LIST_HEAD(&parent->
 298                                                         variant.dir_variant.
 299                                                         children);
 300                                         } else if (!parent ||
 301                                                 parent->variant_type !=
 302                                                 YAFFS_OBJECT_TYPE_DIRECTORY) {
 303                                                 /* Hoosterman, a problem....
 304                                                  * We're trying to use a
 305                                                  * non-directory as a directory
 306                                                  */
 307
 308                                                 yaffs_trace(YAFFS_TRACE_ERROR,
 309                                                         "yaffs tragedy: attempting to use non-directory as a directory in scan. Put in lost+found."
 310                                                         );
 311                                                 parent = dev->lost_n_found;
 312                                         }
 313
 314                                         yaffs_add_obj_to_dir(parent, in);
 315
 316                                         switch (in->variant_type) {
 317                                         case YAFFS_OBJECT_TYPE_UNKNOWN:
 318                                                 /* Todo got a problem */
 319                                                 break;
 320                                         case YAFFS_OBJECT_TYPE_FILE:
 321                                                 if (dev->param.
 322                                                     use_header_file_size)
 323                                                         in->variant.
 324                                                         file_variant.file_size
 325                                                         = yaffs_oh_to_size(oh);
 326                                                 break;
 327                                         case YAFFS_OBJECT_TYPE_HARDLINK:
 328                                                 in->variant.
 329                                                     hardlink_variant.equiv_id =
 330                                                     oh->equiv_id;
 331                                                 list_add(&in->hard_links,
 332                                                                 &hard_list);
 333                                                 break;
 334                                         case YAFFS_OBJECT_TYPE_DIRECTORY:
 335                                                 /* Do nothing */
 336                                                 break;
 337                                         case YAFFS_OBJECT_TYPE_SPECIAL:
 338                                                 /* Do nothing */
 339                                                 break;
 340                                         case YAFFS_OBJECT_TYPE_SYMLINK:
 341                                                 in->variant.symlink_variant.
 342                                                     alias =
 343                                                     yaffs_clone_str(oh->alias);
 344                                                 if (!in->variant.
 345                                                     symlink_variant.alias)
 346                                                         alloc_failed = 1;
 347                                                 break;
 348                                         }
 349                                 }
 350                         }
 351                 }
 352
 353                 if (state == YAFFS_BLOCK_STATE_NEEDS_SCAN) {
 354                         /* If we got this far while scanning,
 355                          * then the block is fully allocated. */
 356                         state = YAFFS_BLOCK_STATE_FULL;
 357                 }
 358
 359                 if (state == YAFFS_BLOCK_STATE_ALLOCATING) {
 360                         /* If the block was partially allocated then
 361                          * treat it as fully allocated. */
 362                         state = YAFFS_BLOCK_STATE_FULL;
 363                         dev->alloc_block = -1;
 364                 }
 365
 366                 bi->block_state = state;
 367
 368                 /* Now let's see if it was dirty */
 369                 if (bi->pages_in_use == 0 &&
 370                     !bi->has_shrink_hdr &&
 371                     bi->block_state == YAFFS_BLOCK_STATE_FULL)
 372                         yaffs_block_became_dirty(dev, blk);
 373         }
 374
 375         /* Ok, we've done all the scanning.
 376          * Fix up the hard link chains.
 377          * We should now have scanned all the objects, now it's time to add
 378          * these hardlinks.
 379          */
 380
 381         yaffs_link_fixup(dev, &hard_list);
 382
 383         /*
 384          * Fix up any shadowed objects.
 385          * There should not be more than one of these.
 386          */
 387         {
 388                 struct yaffs_shadow_fixer *fixer;
 389                 struct yaffs_obj *obj;
 390
 391                 while (shadow_fixers) {
 392                         fixer = shadow_fixers;
 393                         shadow_fixers = fixer->next;
 394                         /* Complete the rename transaction by deleting the
 395                          * shadowed object then setting the object header
 396                          to unshadowed.
 397                          */
 398                         obj = yaffs_find_by_number(dev, fixer->shadowed_id);
 399                         if (obj)
 400                                 yaffs_del_obj(obj);
 401
 402                         obj = yaffs_find_by_number(dev, fixer->obj_id);
 403
 404                         if (obj)
 405                                 yaffs_update_oh(obj, NULL, 1, 0, 0, NULL);
 406
 407                         kfree(fixer);
 408                 }
 409         }
 410
 411         yaffs_release_temp_buffer(dev, chunk_data);
 412
 413         if (alloc_failed)
 414                 return YAFFS_FAIL;
 415
 416         yaffs_trace(YAFFS_TRACE_SCAN, "yaffs1_scan ends");
 417
 418         return YAFFS_OK;
 419 }