yaffs_guts.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 "yportenv.h"
  15 #include "yaffs_trace.h"
  16
  17 #include "yaffs_guts.h"
  18 #include "yaffs_getblockinfo.h"
  19 #include "yaffs_tagscompat.h"
  20 #include "yaffs_nand.h"
  21 #include "yaffs_yaffs1.h"
  22 #include "yaffs_yaffs2.h"
  23 #include "yaffs_bitmap.h"
  24 #include "yaffs_verify.h"
  25 #include "yaffs_nand.h"
  26 #include "yaffs_packedtags2.h"
  27 #include "yaffs_nameval.h"
  28 #include "yaffs_allocator.h"
  29 #include "yaffs_attribs.h"
  30 #include "yaffs_summary.h"
  31
  32 /* Note YAFFS_GC_GOOD_ENOUGH must be <= YAFFS_GC_PASSIVE_THRESHOLD */
  33 #define YAFFS_GC_GOOD_ENOUGH 2
  34 #define YAFFS_GC_PASSIVE_THRESHOLD 4
  35
  36 #include "yaffs_ecc.h"
  37
  38 /* Forward declarations */
  39
  40 static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
  41                              const u8 *buffer, int n_bytes, int use_reserve);
  42
  43
  44
  45 /* Function to calculate chunk and offset */
  46
  47 static inline void yaffs_addr_to_chunk(struct yaffs_dev *dev, loff_t addr,
  48                                         int *chunk_out, u32 *offset_out)
  49 {
  50         int chunk;
  51         u32 offset;
  52
  53         chunk = (u32) (addr >> dev->chunk_shift);
  54
  55         if (dev->chunk_div == 1) {
  56                 /* easy power of 2 case */
  57                 offset = (u32) (addr & dev->chunk_mask);
  58         } else {
  59                 /* Non power-of-2 case */
  60
  61                 loff_t chunk_base;
  62
  63                 chunk /= dev->chunk_div;
  64
  65                 chunk_base = ((loff_t) chunk) * dev->data_bytes_per_chunk;
  66                 offset = (u32) (addr - chunk_base);
  67         }
  68
  69         *chunk_out = chunk;
  70         *offset_out = offset;
  71 }
  72
  73 /* Function to return the number of shifts for a power of 2 greater than or
  74  * equal to the given number
  75  * Note we don't try to cater for all possible numbers and this does not have to
  76  * be hellishly efficient.
  77  */
  78
  79 static inline u32 calc_shifts_ceiling(u32 x)
  80 {
  81         int extra_bits;
  82         int shifts;
  83
  84         shifts = extra_bits = 0;
  85
  86         while (x > 1) {
  87                 if (x & 1)
  88                         extra_bits++;
  89                 x >>= 1;
  90                 shifts++;
  91         }
  92
  93         if (extra_bits)
  94                 shifts++;
  95
  96         return shifts;
  97 }
  98
  99 /* Function to return the number of shifts to get a 1 in bit 0
 100  */
 101
 102 static inline u32 calc_shifts(u32 x)
 103 {
 104         u32 shifts;
 105
 106         shifts = 0;
 107
 108         if (!x)
 109                 return 0;
 110
 111         while (!(x & 1)) {
 112                 x >>= 1;
 113                 shifts++;
 114         }
 115
 116         return shifts;
 117 }
 118
 119 /*
 120  * Temporary buffer manipulations.
 121  */
 122
 123 static int yaffs_init_tmp_buffers(struct yaffs_dev *dev)
 124 {
 125         int i;
 126         u8 *buf = (u8 *) 1;
 127
 128         memset(dev->temp_buffer, 0, sizeof(dev->temp_buffer));
 129
 130         for (i = 0; buf && i < YAFFS_N_TEMP_BUFFERS; i++) {
 131                 dev->temp_buffer[i].in_use = 0;
 132                 buf = kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
 133                 dev->temp_buffer[i].buffer = buf;
 134         }
 135
 136         return buf ? YAFFS_OK : YAFFS_FAIL;
 137 }
 138
 139 u8 *yaffs_get_temp_buffer(struct yaffs_dev * dev)
 140 {
 141         int i;
 142
 143         dev->temp_in_use++;
 144         if (dev->temp_in_use > dev->max_temp)
 145                 dev->max_temp = dev->temp_in_use;
 146
 147         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
 148                 if (dev->temp_buffer[i].in_use == 0) {
 149                         dev->temp_buffer[i].in_use = 1;
 150                         return dev->temp_buffer[i].buffer;
 151                 }
 152         }
 153
 154         yaffs_trace(YAFFS_TRACE_BUFFERS, "Out of temp buffers");
 155         /*
 156          * If we got here then we have to allocate an unmanaged one
 157          * This is not good.
 158          */
 159
 160         dev->unmanaged_buffer_allocs++;
 161         return kmalloc(dev->data_bytes_per_chunk, GFP_NOFS);
 162
 163 }
 164
 165 void yaffs_release_temp_buffer(struct yaffs_dev *dev, u8 *buffer)
 166 {
 167         int i;
 168
 169         dev->temp_in_use--;
 170
 171         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
 172                 if (dev->temp_buffer[i].buffer == buffer) {
 173                         dev->temp_buffer[i].in_use = 0;
 174                         return;
 175                 }
 176         }
 177
 178         if (buffer) {
 179                 /* assume it is an unmanaged one. */
 180                 yaffs_trace(YAFFS_TRACE_BUFFERS, "Releasing unmanaged temp buffer");
 181                 kfree(buffer);
 182                 dev->unmanaged_buffer_deallocs++;
 183         }
 184
 185 }
 186
 187 /*
 188  * Determine if we have a managed buffer.
 189  */
 190 int yaffs_is_managed_tmp_buffer(struct yaffs_dev *dev, const u8 *buffer)
 191 {
 192         int i;
 193
 194         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
 195                 if (dev->temp_buffer[i].buffer == buffer)
 196                         return 1;
 197         }
 198
 199         for (i = 0; i < dev->param.n_caches; i++) {
 200                 if (dev->cache[i].data == buffer)
 201                         return 1;
 202         }
 203
 204         if (buffer == dev->checkpt_buffer)
 205                 return 1;
 206
 207         yaffs_trace(YAFFS_TRACE_ALWAYS,
 208           "yaffs: unmaged buffer detected.");
 209         return 0;
 210 }
 211
 212 /*
 213  * Functions for robustisizing TODO
 214  *
 215  */
 216
 217 static void yaffs_handle_chunk_wr_ok(struct yaffs_dev *dev, int nand_chunk,
 218                                      const u8 *data,
 219                                      const struct yaffs_ext_tags *tags)
 220 {
 221         dev = dev;
 222         nand_chunk = nand_chunk;
 223         data = data;
 224         tags = tags;
 225 }
 226
 227 static void yaffs_handle_chunk_update(struct yaffs_dev *dev, int nand_chunk,
 228                                       const struct yaffs_ext_tags *tags)
 229 {
 230         dev = dev;
 231         nand_chunk = nand_chunk;
 232         tags = tags;
 233 }
 234
 235 void yaffs_handle_chunk_error(struct yaffs_dev *dev,
 236                               struct yaffs_block_info *bi)
 237 {
 238         if (!bi->gc_prioritise) {
 239                 bi->gc_prioritise = 1;
 240                 dev->has_pending_prioritised_gc = 1;
 241                 bi->chunk_error_strikes++;
 242
 243                 if (bi->chunk_error_strikes > 3) {
 244                         bi->needs_retiring = 1; /* Too many stikes, so retire */
 245                         yaffs_trace(YAFFS_TRACE_ALWAYS,
 246                                 "yaffs: Block struck out");
 247
 248                 }
 249         }
 250 }
 251
 252 static void yaffs_handle_chunk_wr_error(struct yaffs_dev *dev, int nand_chunk,
 253                                         int erased_ok)
 254 {
 255         int flash_block = nand_chunk / dev->param.chunks_per_block;
 256         struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
 257
 258         yaffs_handle_chunk_error(dev, bi);
 259
 260         if (erased_ok) {
 261                 /* Was an actual write failure,
 262                  * so mark the block for retirement.*/
 263                 bi->needs_retiring = 1;
 264                 yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
 265                   "**>> Block %d needs retiring", flash_block);
 266         }
 267
 268         /* Delete the chunk */
 269         yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
 270         yaffs_skip_rest_of_block(dev);
 271 }
 272
 273 /*
 274  * Verification code
 275  */
 276
 277 /*
 278  *  Simple hash function. Needs to have a reasonable spread
 279  */
 280
 281 static inline int yaffs_hash_fn(int n)
 282 {
 283         n = abs(n);
 284         return n % YAFFS_NOBJECT_BUCKETS;
 285 }
 286
 287 /*
 288  * Access functions to useful fake objects.
 289  * Note that root might have a presence in NAND if permissions are set.
 290  */
 291
 292 struct yaffs_obj *yaffs_root(struct yaffs_dev *dev)
 293 {
 294         return dev->root_dir;
 295 }
 296
 297 struct yaffs_obj *yaffs_lost_n_found(struct yaffs_dev *dev)
 298 {
 299         return dev->lost_n_found;
 300 }
 301
 302 /*
 303  *  Erased NAND checking functions
 304  */
 305
 306 int yaffs_check_ff(u8 *buffer, int n_bytes)
 307 {
 308         /* Horrible, slow implementation */
 309         while (n_bytes--) {
 310                 if (*buffer != 0xff)
 311                         return 0;
 312                 buffer++;
 313         }
 314         return 1;
 315 }
 316
 317 static int yaffs_check_chunk_erased(struct yaffs_dev *dev, int nand_chunk)
 318 {
 319         int retval = YAFFS_OK;
 320         u8 *data = yaffs_get_temp_buffer(dev);
 321         struct yaffs_ext_tags tags;
 322         int result;
 323
 324         result = yaffs_rd_chunk_tags_nand(dev, nand_chunk, data, &tags);
 325
 326         if (tags.ecc_result > YAFFS_ECC_RESULT_NO_ERROR)
 327                 retval = YAFFS_FAIL;
 328
 329         if (!yaffs_check_ff(data, dev->data_bytes_per_chunk) ||
 330                 tags.chunk_used) {
 331                 yaffs_trace(YAFFS_TRACE_NANDACCESS,
 332                         "Chunk %d not erased", nand_chunk);
 333                 retval = YAFFS_FAIL;
 334         }
 335
 336         yaffs_release_temp_buffer(dev, data);
 337
 338         return retval;
 339
 340 }
 341
 342 static int yaffs_verify_chunk_written(struct yaffs_dev *dev,
 343                                       int nand_chunk,
 344                                       const u8 *data,
 345                                       struct yaffs_ext_tags *tags)
 346 {
 347         int retval = YAFFS_OK;
 348         struct yaffs_ext_tags temp_tags;
 349         u8 *buffer = yaffs_get_temp_buffer(dev);
 350         int result;
 351
 352         result = yaffs_rd_chunk_tags_nand(dev, nand_chunk, buffer, &temp_tags);
 353         if (memcmp(buffer, data, dev->data_bytes_per_chunk) ||
 354             temp_tags.obj_id != tags->obj_id ||
 355             temp_tags.chunk_id != tags->chunk_id ||
 356             temp_tags.n_bytes != tags->n_bytes)
 357                 retval = YAFFS_FAIL;
 358
 359         yaffs_release_temp_buffer(dev, buffer);
 360
 361         return retval;
 362 }
 363
 364
 365 int yaffs_check_alloc_available(struct yaffs_dev *dev, int n_chunks)
 366 {
 367         int reserved_chunks;
 368         int reserved_blocks = dev->param.n_reserved_blocks;
 369         int checkpt_blocks;
 370
 371         checkpt_blocks = yaffs_calc_checkpt_blocks_required(dev);
 372
 373         reserved_chunks =
 374             (reserved_blocks + checkpt_blocks) * dev->param.chunks_per_block;
 375
 376         return (dev->n_free_chunks > (reserved_chunks + n_chunks));
 377 }
 378
 379 static int yaffs_find_alloc_block(struct yaffs_dev *dev)
 380 {
 381         int i;
 382         struct yaffs_block_info *bi;
 383
 384         if (dev->n_erased_blocks < 1) {
 385                 /* Hoosterman we've got a problem.
 386                  * Can't get space to gc
 387                  */
 388                 yaffs_trace(YAFFS_TRACE_ERROR,
 389                   "yaffs tragedy: no more erased blocks");
 390
 391                 return -1;
 392         }
 393
 394         /* Find an empty block. */
 395
 396         for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
 397                 dev->alloc_block_finder++;
 398                 if (dev->alloc_block_finder < dev->internal_start_block
 399                     || dev->alloc_block_finder > dev->internal_end_block) {
 400                         dev->alloc_block_finder = dev->internal_start_block;
 401                 }
 402
 403                 bi = yaffs_get_block_info(dev, dev->alloc_block_finder);
 404
 405                 if (bi->block_state == YAFFS_BLOCK_STATE_EMPTY) {
 406                         bi->block_state = YAFFS_BLOCK_STATE_ALLOCATING;
 407                         dev->seq_number++;
 408                         bi->seq_number = dev->seq_number;
 409                         dev->n_erased_blocks--;
 410                         yaffs_trace(YAFFS_TRACE_ALLOCATE,
 411                           "Allocated block %d, seq  %d, %d left" ,
 412                            dev->alloc_block_finder, dev->seq_number,
 413                            dev->n_erased_blocks);
 414                         return dev->alloc_block_finder;
 415                 }
 416         }
 417
 418         yaffs_trace(YAFFS_TRACE_ALWAYS,
 419                 "yaffs tragedy: no more erased blocks, but there should have been %d",
 420                 dev->n_erased_blocks);
 421
 422         return -1;
 423 }
 424
 425 static int yaffs_alloc_chunk(struct yaffs_dev *dev, int use_reserver,
 426                              struct yaffs_block_info **block_ptr)
 427 {
 428         int ret_val;
 429         struct yaffs_block_info *bi;
 430
 431         if (dev->alloc_block < 0) {
 432                 /* Get next block to allocate off */
 433                 dev->alloc_block = yaffs_find_alloc_block(dev);
 434                 dev->alloc_page = 0;
 435         }
 436
 437         if (!use_reserver && !yaffs_check_alloc_available(dev, 1)) {
 438                 /* No space unless we're allowed to use the reserve. */
 439                 return -1;
 440         }
 441
 442         if (dev->n_erased_blocks < dev->param.n_reserved_blocks
 443             && dev->alloc_page == 0)
 444                 yaffs_trace(YAFFS_TRACE_ALLOCATE, "Allocating reserve");
 445
 446         /* Next page please.... */
 447         if (dev->alloc_block >= 0) {
 448                 bi = yaffs_get_block_info(dev, dev->alloc_block);
 449
 450                 ret_val = (dev->alloc_block * dev->param.chunks_per_block) +
 451                     dev->alloc_page;
 452                 bi->pages_in_use++;
 453                 yaffs_set_chunk_bit(dev, dev->alloc_block, dev->alloc_page);
 454
 455                 dev->alloc_page++;
 456
 457                 dev->n_free_chunks--;
 458
 459                 /* If the block is full set the state to full */
 460                 if (dev->alloc_page >= dev->param.chunks_per_block) {
 461                         bi->block_state = YAFFS_BLOCK_STATE_FULL;
 462                         dev->alloc_block = -1;
 463                 }
 464
 465                 if (block_ptr)
 466                         *block_ptr = bi;
 467
 468                 return ret_val;
 469         }
 470
 471         yaffs_trace(YAFFS_TRACE_ERROR,
 472                 "!!!!!!!!! Allocator out !!!!!!!!!!!!!!!!!");
 473
 474         return -1;
 475 }
 476
 477 static int yaffs_get_erased_chunks(struct yaffs_dev *dev)
 478 {
 479         int n;
 480
 481         n = dev->n_erased_blocks * dev->param.chunks_per_block;
 482
 483         if (dev->alloc_block > 0)
 484                 n += (dev->param.chunks_per_block - dev->alloc_page);
 485
 486         return n;
 487
 488 }
 489
 490 /*
 491  * yaffs_skip_rest_of_block() skips over the rest of the allocation block
 492  * if we don't want to write to it.
 493  */
 494 void yaffs_skip_rest_of_block(struct yaffs_dev *dev)
 495 {
 496         struct yaffs_block_info *bi;
 497
 498         if (dev->alloc_block > 0) {
 499                 bi = yaffs_get_block_info(dev, dev->alloc_block);
 500                 if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING) {
 501                         bi->block_state = YAFFS_BLOCK_STATE_FULL;
 502                         dev->alloc_block = -1;
 503                 }
 504         }
 505 }
 506
 507 static int yaffs_write_new_chunk(struct yaffs_dev *dev,
 508                                  const u8 *data,
 509                                  struct yaffs_ext_tags *tags, int use_reserver)
 510 {
 511         int attempts = 0;
 512         int write_ok = 0;
 513         int chunk;
 514
 515         yaffs2_checkpt_invalidate(dev);
 516
 517         do {
 518                 struct yaffs_block_info *bi = 0;
 519                 int erased_ok = 0;
 520
 521                 chunk = yaffs_alloc_chunk(dev, use_reserver, &bi);
 522                 if (chunk < 0) {
 523                         /* no space */
 524                         break;
 525                 }
 526
 527                 /* First check this chunk is erased, if it needs
 528                  * checking.  The checking policy (unless forced
 529                  * always on) is as follows:
 530                  *
 531                  * Check the first page we try to write in a block.
 532                  * If the check passes then we don't need to check any
 533                  * more.        If the check fails, we check again...
 534                  * If the block has been erased, we don't need to check.
 535                  *
 536                  * However, if the block has been prioritised for gc,
 537                  * then we think there might be something odd about
 538                  * this block and stop using it.
 539                  *
 540                  * Rationale: We should only ever see chunks that have
 541                  * not been erased if there was a partially written
 542                  * chunk due to power loss.  This checking policy should
 543                  * catch that case with very few checks and thus save a
 544                  * lot of checks that are most likely not needed.
 545                  *
 546                  * Mods to the above
 547                  * If an erase check fails or the write fails we skip the
 548                  * rest of the block.
 549                  */
 550
 551                 /* let's give it a try */
 552                 attempts++;
 553
 554                 if (dev->param.always_check_erased)
 555                         bi->skip_erased_check = 0;
 556
 557                 if (!bi->skip_erased_check) {
 558                         erased_ok = yaffs_check_chunk_erased(dev, chunk);
 559                         if (erased_ok != YAFFS_OK) {
 560                                 yaffs_trace(YAFFS_TRACE_ERROR,
 561                                   "**>> yaffs chunk %d was not erased",
 562                                   chunk);
 563
 564                                 /* If not erased, delete this one,
 565                                  * skip rest of block and
 566                                  * try another chunk */
 567                                 yaffs_chunk_del(dev, chunk, 1, __LINE__);
 568                                 yaffs_skip_rest_of_block(dev);
 569                                 continue;
 570                         }
 571                 }
 572
 573                 write_ok = yaffs_wr_chunk_tags_nand(dev, chunk, data, tags);
 574
 575                 if (!bi->skip_erased_check)
 576                         write_ok =
 577                             yaffs_verify_chunk_written(dev, chunk, data, tags);
 578
 579                 if (write_ok != YAFFS_OK) {
 580                         /* Clean up aborted write, skip to next block and
 581                          * try another chunk */
 582                         yaffs_handle_chunk_wr_error(dev, chunk, erased_ok);
 583                         continue;
 584                 }
 585
 586                 bi->skip_erased_check = 1;
 587
 588                 /* Copy the data into the robustification buffer */
 589                 yaffs_handle_chunk_wr_ok(dev, chunk, data, tags);
 590
 591         } while (write_ok != YAFFS_OK &&
 592                  (yaffs_wr_attempts <= 0 || attempts <= yaffs_wr_attempts));
 593
 594         if (!write_ok)
 595                 chunk = -1;
 596
 597         if (attempts > 1) {
 598                 yaffs_trace(YAFFS_TRACE_ERROR,
 599                         "**>> yaffs write required %d attempts",
 600                         attempts);
 601                 dev->n_retired_writes += (attempts - 1);
 602         }
 603
 604         return chunk;
 605 }
 606
 607 /*
 608  * Block retiring for handling a broken block.
 609  */
 610
 611 static void yaffs_retire_block(struct yaffs_dev *dev, int flash_block)
 612 {
 613         struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
 614
 615         yaffs2_checkpt_invalidate(dev);
 616
 617         yaffs2_clear_oldest_dirty_seq(dev, bi);
 618
 619         if (yaffs_mark_bad(dev, flash_block) != YAFFS_OK) {
 620                 if (yaffs_erase_block(dev, flash_block) != YAFFS_OK) {
 621                         yaffs_trace(YAFFS_TRACE_ALWAYS,
 622                                 "yaffs: Failed to mark bad and erase block %d",
 623                                 flash_block);
 624                 } else {
 625                         struct yaffs_ext_tags tags;
 626                         int chunk_id =
 627                             flash_block * dev->param.chunks_per_block;
 628
 629                         u8 *buffer = yaffs_get_temp_buffer(dev);
 630
 631                         memset(buffer, 0xff, dev->data_bytes_per_chunk);
 632                         memset(&tags, 0, sizeof(tags));
 633                         tags.seq_number = YAFFS_SEQUENCE_BAD_BLOCK;
 634                         if (dev->param.write_chunk_tags_fn(dev, chunk_id -
 635                                                            dev->chunk_offset,
 636                                                            buffer,
 637                                                            &tags) != YAFFS_OK)
 638                                 yaffs_trace(YAFFS_TRACE_ALWAYS,
 639                                         "yaffs: Failed to write bad block marker to block %d",
 640                                         flash_block);
 641
 642                         yaffs_release_temp_buffer(dev, buffer);
 643                 }
 644         }
 645
 646         bi->block_state = YAFFS_BLOCK_STATE_DEAD;
 647         bi->gc_prioritise = 0;
 648         bi->needs_retiring = 0;
 649
 650         dev->n_retired_blocks++;
 651 }
 652
 653 /*---------------- Name handling functions ------------*/
 654
 655 static u16 yaffs_calc_name_sum(const YCHAR *name)
 656 {
 657         u16 sum = 0;
 658         u16 i = 1;
 659
 660         if (!name)
 661                 return 0;
 662
 663         while ((*name) && i < (YAFFS_MAX_NAME_LENGTH / 2)) {
 664
 665                 /* 0x1f mask is case insensitive */
 666                 sum += ((*name) & 0x1f) * i;
 667                 i++;
 668                 name++;
 669         }
 670         return sum;
 671 }
 672
 673 void yaffs_set_obj_name(struct yaffs_obj *obj, const YCHAR * name)
 674 {
 675 #ifndef CONFIG_YAFFS_NO_SHORT_NAMES
 676         memset(obj->short_name, 0, sizeof(obj->short_name));
 677         if (name &&
 678                 strnlen(name, YAFFS_SHORT_NAME_LENGTH + 1) <=
 679                 YAFFS_SHORT_NAME_LENGTH)
 680                 strcpy(obj->short_name, name);
 681         else
 682                 obj->short_name[0] = _Y('\0');
 683 #endif
 684         obj->sum = yaffs_calc_name_sum(name);
 685 }
 686
 687 void yaffs_set_obj_name_from_oh(struct yaffs_obj *obj,
 688                                 const struct yaffs_obj_hdr *oh)
 689 {
 690 #ifdef CONFIG_YAFFS_AUTO_UNICODE
 691         YCHAR tmp_name[YAFFS_MAX_NAME_LENGTH + 1];
 692         memset(tmp_name, 0, sizeof(tmp_name));
 693         yaffs_load_name_from_oh(obj->my_dev, tmp_name, oh->name,
 694                                 YAFFS_MAX_NAME_LENGTH + 1);
 695         yaffs_set_obj_name(obj, tmp_name);
 696 #else
 697         yaffs_set_obj_name(obj, oh->name);
 698 #endif
 699 }
 700
 701 /*-------------------- TNODES -------------------
 702
 703  * List of spare tnodes
 704  * The list is hooked together using the first pointer
 705  * in the tnode.
 706  */
 707
 708 struct yaffs_tnode *yaffs_get_tnode(struct yaffs_dev *dev)
 709 {
 710         struct yaffs_tnode *tn = yaffs_alloc_raw_tnode(dev);
 711
 712         if (tn) {
 713                 memset(tn, 0, dev->tnode_size);
 714                 dev->n_tnodes++;
 715         }
 716
 717         dev->checkpoint_blocks_required = 0;    /* force recalculation */
 718
 719         return tn;
 720 }
 721
 722 /* FreeTnode frees up a tnode and puts it back on the free list */
 723 static void yaffs_free_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
 724 {
 725         yaffs_free_raw_tnode(dev, tn);
 726         dev->n_tnodes--;
 727         dev->checkpoint_blocks_required = 0;    /* force recalculation */
 728 }
 729
 730 static void yaffs_deinit_tnodes_and_objs(struct yaffs_dev *dev)
 731 {
 732         yaffs_deinit_raw_tnodes_and_objs(dev);
 733         dev->n_obj = 0;
 734         dev->n_tnodes = 0;
 735 }
 736
 737 void yaffs_load_tnode_0(struct yaffs_dev *dev, struct yaffs_tnode *tn,
 738                         unsigned pos, unsigned val)
 739 {
 740         u32 *map = (u32 *) tn;
 741         u32 bit_in_map;
 742         u32 bit_in_word;
 743         u32 word_in_map;
 744         u32 mask;
 745
 746         pos &= YAFFS_TNODES_LEVEL0_MASK;
 747         val >>= dev->chunk_grp_bits;
 748
 749         bit_in_map = pos * dev->tnode_width;
 750         word_in_map = bit_in_map / 32;
 751         bit_in_word = bit_in_map & (32 - 1);
 752
 753         mask = dev->tnode_mask << bit_in_word;
 754
 755         map[word_in_map] &= ~mask;
 756         map[word_in_map] |= (mask & (val << bit_in_word));
 757
 758         if (dev->tnode_width > (32 - bit_in_word)) {
 759                 bit_in_word = (32 - bit_in_word);
 760                 word_in_map++;
 761                 mask =
 762                     dev->tnode_mask >> bit_in_word;
 763                 map[word_in_map] &= ~mask;
 764                 map[word_in_map] |= (mask & (val >> bit_in_word));
 765         }
 766 }
 767
 768 u32 yaffs_get_group_base(struct yaffs_dev *dev, struct yaffs_tnode *tn,
 769                          unsigned pos)
 770 {
 771         u32 *map = (u32 *) tn;
 772         u32 bit_in_map;
 773         u32 bit_in_word;
 774         u32 word_in_map;
 775         u32 val;
 776
 777         pos &= YAFFS_TNODES_LEVEL0_MASK;
 778
 779         bit_in_map = pos * dev->tnode_width;
 780         word_in_map = bit_in_map / 32;
 781         bit_in_word = bit_in_map & (32 - 1);
 782
 783         val = map[word_in_map] >> bit_in_word;
 784
 785         if (dev->tnode_width > (32 - bit_in_word)) {
 786                 bit_in_word = (32 - bit_in_word);
 787                 word_in_map++;
 788                 val |= (map[word_in_map] << bit_in_word);
 789         }
 790
 791         val &= dev->tnode_mask;
 792         val <<= dev->chunk_grp_bits;
 793
 794         return val;
 795 }
 796
 797 /* ------------------- End of individual tnode manipulation -----------------*/
 798
 799 /* ---------Functions to manipulate the look-up tree (made up of tnodes) ------
 800  * The look up tree is represented by the top tnode and the number of top_level
 801  * in the tree. 0 means only the level 0 tnode is in the tree.
 802  */
 803
 804 /* FindLevel0Tnode finds the level 0 tnode, if one exists. */
 805 struct yaffs_tnode *yaffs_find_tnode_0(struct yaffs_dev *dev,
 806                                        struct yaffs_file_var *file_struct,
 807                                        u32 chunk_id)
 808 {
 809         struct yaffs_tnode *tn = file_struct->top;
 810         u32 i;
 811         int required_depth;
 812         int level = file_struct->top_level;
 813
 814         dev = dev;
 815
 816         /* Check sane level and chunk Id */
 817         if (level < 0 || level > YAFFS_TNODES_MAX_LEVEL)
 818                 return NULL;
 819
 820         if (chunk_id > YAFFS_MAX_CHUNK_ID)
 821                 return NULL;
 822
 823         /* First check we're tall enough (ie enough top_level) */
 824
 825         i = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
 826         required_depth = 0;
 827         while (i) {
 828                 i >>= YAFFS_TNODES_INTERNAL_BITS;
 829                 required_depth++;
 830         }
 831
 832         if (required_depth > file_struct->top_level)
 833                 return NULL;    /* Not tall enough, so we can't find it */
 834
 835         /* Traverse down to level 0 */
 836         while (level > 0 && tn) {
 837                 tn = tn->internal[(chunk_id >>
 838                                    (YAFFS_TNODES_LEVEL0_BITS +
 839                                     (level - 1) *
 840                                     YAFFS_TNODES_INTERNAL_BITS)) &
 841                                   YAFFS_TNODES_INTERNAL_MASK];
 842                 level--;
 843         }
 844
 845         return tn;
 846 }
 847
 848 /* add_find_tnode_0 finds the level 0 tnode if it exists,
 849  * otherwise first expands the tree.
 850  * This happens in two steps:
 851  *  1. If the tree isn't tall enough, then make it taller.
 852  *  2. Scan down the tree towards the level 0 tnode adding tnodes if required.
 853  *
 854  * Used when modifying the tree.
 855  *
 856  *  If the tn argument is NULL, then a fresh tnode will be added otherwise the
 857  *  specified tn will be plugged into the ttree.
 858  */
 859
 860 struct yaffs_tnode *yaffs_add_find_tnode_0(struct yaffs_dev *dev,
 861                                            struct yaffs_file_var *file_struct,
 862                                            u32 chunk_id,
 863                                            struct yaffs_tnode *passed_tn)
 864 {
 865         int required_depth;
 866         int i;
 867         int l;
 868         struct yaffs_tnode *tn;
 869         u32 x;
 870
 871         /* Check sane level and page Id */
 872         if (file_struct->top_level < 0 ||
 873             file_struct->top_level > YAFFS_TNODES_MAX_LEVEL)
 874                 return NULL;
 875
 876         if (chunk_id > YAFFS_MAX_CHUNK_ID)
 877                 return NULL;
 878
 879         /* First check we're tall enough (ie enough top_level) */
 880
 881         x = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
 882         required_depth = 0;
 883         while (x) {
 884                 x >>= YAFFS_TNODES_INTERNAL_BITS;
 885                 required_depth++;
 886         }
 887
 888         if (required_depth > file_struct->top_level) {
 889                 /* Not tall enough, gotta make the tree taller */
 890                 for (i = file_struct->top_level; i < required_depth; i++) {
 891
 892                         tn = yaffs_get_tnode(dev);
 893
 894                         if (tn) {
 895                                 tn->internal[0] = file_struct->top;
 896                                 file_struct->top = tn;
 897                                 file_struct->top_level++;
 898                         } else {
 899                                 yaffs_trace(YAFFS_TRACE_ERROR,
 900                                         "yaffs: no more tnodes");
 901                                 return NULL;
 902                         }
 903                 }
 904         }
 905
 906         /* Traverse down to level 0, adding anything we need */
 907
 908         l = file_struct->top_level;
 909         tn = file_struct->top;
 910
 911         if (l > 0) {
 912                 while (l > 0 && tn) {
 913                         x = (chunk_id >>
 914                              (YAFFS_TNODES_LEVEL0_BITS +
 915                               (l - 1) * YAFFS_TNODES_INTERNAL_BITS)) &
 916                             YAFFS_TNODES_INTERNAL_MASK;
 917
 918                         if ((l > 1) && !tn->internal[x]) {
 919                                 /* Add missing non-level-zero tnode */
 920                                 tn->internal[x] = yaffs_get_tnode(dev);
 921                                 if (!tn->internal[x])
 922                                         return NULL;
 923                         } else if (l == 1) {
 924                                 /* Looking from level 1 at level 0 */
 925                                 if (passed_tn) {
 926                                         /* If we already have one, release it */
 927                                         if (tn->internal[x])
 928                                                 yaffs_free_tnode(dev,
 929                                                         tn->internal[x]);
 930                                         tn->internal[x] = passed_tn;
 931
 932                                 } else if (!tn->internal[x]) {
 933                                         /* Don't have one, none passed in */
 934                                         tn->internal[x] = yaffs_get_tnode(dev);
 935                                         if (!tn->internal[x])
 936                                                 return NULL;
 937                                 }
 938                         }
 939
 940                         tn = tn->internal[x];
 941                         l--;
 942                 }
 943         } else {
 944                 /* top is level 0 */
 945                 if (passed_tn) {
 946                         memcpy(tn, passed_tn,
 947                                (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8);
 948                         yaffs_free_tnode(dev, passed_tn);
 949                 }
 950         }
 951
 952         return tn;
 953 }
 954
 955 static int yaffs_tags_match(const struct yaffs_ext_tags *tags, int obj_id,
 956                             int chunk_obj)
 957 {
 958         return (tags->chunk_id == chunk_obj &&
 959                 tags->obj_id == obj_id &&
 960                 !tags->is_deleted) ? 1 : 0;
 961
 962 }
 963
 964 static int yaffs_find_chunk_in_group(struct yaffs_dev *dev, int the_chunk,
 965                                         struct yaffs_ext_tags *tags, int obj_id,
 966                                         int inode_chunk)
 967 {
 968         int j;
 969
 970         for (j = 0; the_chunk && j < dev->chunk_grp_size; j++) {
 971                 if (yaffs_check_chunk_bit
 972                     (dev, the_chunk / dev->param.chunks_per_block,
 973                      the_chunk % dev->param.chunks_per_block)) {
 974
 975                         if (dev->chunk_grp_size == 1)
 976                                 return the_chunk;
 977                         else {
 978                                 yaffs_rd_chunk_tags_nand(dev, the_chunk, NULL,
 979                                                          tags);
 980                                 if (yaffs_tags_match(tags,
 981                                                         obj_id, inode_chunk)) {
 982                                         /* found it; */
 983                                         return the_chunk;
 984                                 }
 985                         }
 986                 }
 987                 the_chunk++;
 988         }
 989         return -1;
 990 }
 991
 992 static int yaffs_find_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
 993                                     struct yaffs_ext_tags *tags)
 994 {
 995         /*Get the Tnode, then get the level 0 offset chunk offset */
 996         struct yaffs_tnode *tn;
 997         int the_chunk = -1;
 998         struct yaffs_ext_tags local_tags;
 999         int ret_val = -1;
1000         struct yaffs_dev *dev = in->my_dev;
1001
1002         if (!tags) {
1003                 /* Passed a NULL, so use our own tags space */
1004                 tags = &local_tags;
1005         }
1006
1007         tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
1008
1009         if (!tn)
1010                 return ret_val;
1011
1012         the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
1013
1014         ret_val = yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
1015                                               inode_chunk);
1016         return ret_val;
1017 }
1018
1019 static int yaffs_find_del_file_chunk(struct yaffs_obj *in, int inode_chunk,
1020                                      struct yaffs_ext_tags *tags)
1021 {
1022         /* Get the Tnode, then get the level 0 offset chunk offset */
1023         struct yaffs_tnode *tn;
1024         int the_chunk = -1;
1025         struct yaffs_ext_tags local_tags;
1026         struct yaffs_dev *dev = in->my_dev;
1027         int ret_val = -1;
1028
1029         if (!tags) {
1030                 /* Passed a NULL, so use our own tags space */
1031                 tags = &local_tags;
1032         }
1033
1034         tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
1035
1036         if (!tn)
1037                 return ret_val;
1038
1039         the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
1040
1041         ret_val = yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
1042                                               inode_chunk);
1043
1044         /* Delete the entry in the filestructure (if found) */
1045         if (ret_val != -1)
1046                 yaffs_load_tnode_0(dev, tn, inode_chunk, 0);
1047
1048         return ret_val;
1049 }
1050
1051 int yaffs_put_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
1052                             int nand_chunk, int in_scan)
1053 {
1054         /* NB in_scan is zero unless scanning.
1055          * For forward scanning, in_scan is > 0;
1056          * for backward scanning in_scan is < 0
1057          *
1058          * nand_chunk = 0 is a dummy insert to make sure the tnodes are there.
1059          */
1060
1061         struct yaffs_tnode *tn;
1062         struct yaffs_dev *dev = in->my_dev;
1063         int existing_cunk;
1064         struct yaffs_ext_tags existing_tags;
1065         struct yaffs_ext_tags new_tags;
1066         unsigned existing_serial, new_serial;
1067
1068         if (in->variant_type != YAFFS_OBJECT_TYPE_FILE) {
1069                 /* Just ignore an attempt at putting a chunk into a non-file
1070                  * during scanning.
1071                  * If it is not during Scanning then something went wrong!
1072                  */
1073                 if (!in_scan) {
1074                         yaffs_trace(YAFFS_TRACE_ERROR,
1075                                 "yaffs tragedy:attempt to put data chunk into a non-file"
1076                                 );
1077                         BUG();
1078                 }
1079
1080                 yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
1081                 return YAFFS_OK;
1082         }
1083
1084         tn = yaffs_add_find_tnode_0(dev,
1085                                     &in->variant.file_variant,
1086                                     inode_chunk, NULL);
1087         if (!tn)
1088                 return YAFFS_FAIL;
1089
1090         if (!nand_chunk)
1091                 /* Dummy insert, bail now */
1092                 return YAFFS_OK;
1093
1094         existing_cunk = yaffs_get_group_base(dev, tn, inode_chunk);
1095
1096         if (in_scan != 0) {
1097                 /* If we're scanning then we need to test for duplicates
1098                  * NB This does not need to be efficient since it should only
1099                  * happen when the power fails during a write, then only one
1100                  * chunk should ever be affected.
1101                  *
1102                  * Correction for YAFFS2: This could happen quite a lot and we
1103                  * need to think about efficiency! TODO
1104                  * Update: For backward scanning we don't need to re-read tags
1105                  * so this is quite cheap.
1106                  */
1107
1108                 if (existing_cunk > 0) {
1109                         /* NB Right now existing chunk will not be real
1110                          * chunk_id if the chunk group size > 1
1111                          * thus we have to do a FindChunkInFile to get the
1112                          * real chunk id.
1113                          *
1114                          * We have a duplicate now we need to decide which
1115                          * one to use:
1116                          *
1117                          * Backwards scanning YAFFS2: The old one is what
1118                          * we use, dump the new one.
1119                          * YAFFS1: Get both sets of tags and compare serial
1120                          * numbers.
1121                          */
1122
1123                         if (in_scan > 0) {
1124                                 /* Only do this for forward scanning */
1125                                 yaffs_rd_chunk_tags_nand(dev,
1126                                                          nand_chunk,
1127                                                          NULL, &new_tags);
1128
1129                                 /* Do a proper find */
1130                                 existing_cunk =
1131                                     yaffs_find_chunk_in_file(in, inode_chunk,
1132                                                              &existing_tags);
1133                         }
1134
1135                         if (existing_cunk <= 0) {
1136                                 /*Hoosterman - how did this happen? */
1137
1138                                 yaffs_trace(YAFFS_TRACE_ERROR,
1139                                         "yaffs tragedy: existing chunk < 0 in scan"
1140                                         );
1141
1142                         }
1143
1144                         /* NB The deleted flags should be false, otherwise
1145                          * the chunks will not be loaded during a scan
1146                          */
1147
1148                         if (in_scan > 0) {
1149                                 new_serial = new_tags.serial_number;
1150                                 existing_serial = existing_tags.serial_number;
1151                         }
1152
1153                         if ((in_scan > 0) &&
1154                             (existing_cunk <= 0 ||
1155                              ((existing_serial + 1) & 3) == new_serial)) {
1156                                 /* Forward scanning.
1157                                  * Use new
1158                                  * Delete the old one and drop through to
1159                                  * update the tnode
1160                                  */
1161                                 yaffs_chunk_del(dev, existing_cunk, 1,
1162                                                 __LINE__);
1163                         } else {
1164                                 /* Backward scanning or we want to use the
1165                                  * existing one
1166                                  * Delete the new one and return early so that
1167                                  * the tnode isn't changed
1168                                  */
1169                                 yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
1170                                 return YAFFS_OK;
1171                         }
1172                 }
1173
1174         }
1175
1176         if (existing_cunk == 0)
1177                 in->n_data_chunks++;
1178
1179         yaffs_load_tnode_0(dev, tn, inode_chunk, nand_chunk);
1180
1181         return YAFFS_OK;
1182 }
1183
1184 static void yaffs_soft_del_chunk(struct yaffs_dev *dev, int chunk)
1185 {
1186         struct yaffs_block_info *the_block;
1187         unsigned block_no;
1188
1189         yaffs_trace(YAFFS_TRACE_DELETION, "soft delete chunk %d", chunk);
1190
1191         block_no = chunk / dev->param.chunks_per_block;
1192         the_block = yaffs_get_block_info(dev, block_no);
1193         if (the_block) {
1194                 the_block->soft_del_pages++;
1195                 dev->n_free_chunks++;
1196                 yaffs2_update_oldest_dirty_seq(dev, block_no, the_block);
1197         }
1198 }
1199
1200 /* SoftDeleteWorker scans backwards through the tnode tree and soft deletes all
1201  * the chunks in the file.
1202  * All soft deleting does is increment the block's softdelete count and pulls
1203  * the chunk out of the tnode.
1204  * Thus, essentially this is the same as DeleteWorker except that the chunks
1205  * are soft deleted.
1206  */
1207
1208 static int yaffs_soft_del_worker(struct yaffs_obj *in, struct yaffs_tnode *tn,
1209                                  u32 level, int chunk_offset)
1210 {
1211         int i;
1212         int the_chunk;
1213         int all_done = 1;
1214         struct yaffs_dev *dev = in->my_dev;
1215
1216         if (!tn)
1217                 return 1;
1218
1219         if (level > 0) {
1220                 for (i = YAFFS_NTNODES_INTERNAL - 1;
1221                         all_done && i >= 0;
1222                         i--) {
1223                         if (tn->internal[i]) {
1224                                 all_done =
1225                                     yaffs_soft_del_worker(in,
1226                                         tn->internal[i],
1227                                         level - 1,
1228                                         (chunk_offset <<
1229                                         YAFFS_TNODES_INTERNAL_BITS)
1230                                         + i);
1231                                 if (all_done) {
1232                                         yaffs_free_tnode(dev,
1233                                                 tn->internal[i]);
1234                                         tn->internal[i] = NULL;
1235                                 } else {
1236                                         /* Can this happen? */
1237                                 }
1238                         }
1239                 }
1240                 return (all_done) ? 1 : 0;
1241         }
1242
1243         /* level 0 */
1244          for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0; i--) {
1245                 the_chunk = yaffs_get_group_base(dev, tn, i);
1246                 if (the_chunk) {
1247                         yaffs_soft_del_chunk(dev, the_chunk);
1248                         yaffs_load_tnode_0(dev, tn, i, 0);
1249                 }
1250         }
1251         return 1;
1252 }
1253
1254 static void yaffs_remove_obj_from_dir(struct yaffs_obj *obj)
1255 {
1256         struct yaffs_dev *dev = obj->my_dev;
1257         struct yaffs_obj *parent;
1258
1259         yaffs_verify_obj_in_dir(obj);
1260         parent = obj->parent;
1261
1262         yaffs_verify_dir(parent);
1263
1264         if (dev && dev->param.remove_obj_fn)
1265                 dev->param.remove_obj_fn(obj);
1266
1267         list_del_init(&obj->siblings);
1268         obj->parent = NULL;
1269
1270         yaffs_verify_dir(parent);
1271 }
1272
1273 void yaffs_add_obj_to_dir(struct yaffs_obj *directory, struct yaffs_obj *obj)
1274 {
1275         if (!directory) {
1276                 yaffs_trace(YAFFS_TRACE_ALWAYS,
1277                         "tragedy: Trying to add an object to a null pointer directory"
1278                         );
1279                 BUG();
1280                 return;
1281         }
1282         if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
1283                 yaffs_trace(YAFFS_TRACE_ALWAYS,
1284                         "tragedy: Trying to add an object to a non-directory"
1285                         );
1286                 BUG();
1287         }
1288
1289         if (obj->siblings.prev == NULL) {
1290                 /* Not initialised */
1291                 BUG();
1292         }
1293
1294         yaffs_verify_dir(directory);
1295
1296         yaffs_remove_obj_from_dir(obj);
1297
1298         /* Now add it */
1299         list_add(&obj->siblings, &directory->variant.dir_variant.children);
1300         obj->parent = directory;
1301
1302         if (directory == obj->my_dev->unlinked_dir
1303             || directory == obj->my_dev->del_dir) {
1304                 obj->unlinked = 1;
1305                 obj->my_dev->n_unlinked_files++;
1306                 obj->rename_allowed = 0;
1307         }
1308
1309         yaffs_verify_dir(directory);
1310         yaffs_verify_obj_in_dir(obj);
1311 }
1312
1313 static int yaffs_change_obj_name(struct yaffs_obj *obj,
1314                                  struct yaffs_obj *new_dir,
1315                                  const YCHAR *new_name, int force, int shadows)
1316 {
1317         int unlink_op;
1318         int del_op;
1319         struct yaffs_obj *existing_target;
1320
1321         if (new_dir == NULL)
1322                 new_dir = obj->parent;  /* use the old directory */
1323
1324         if (new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
1325                 yaffs_trace(YAFFS_TRACE_ALWAYS,
1326                         "tragedy: yaffs_change_obj_name: new_dir is not a directory"
1327                         );
1328                 BUG();
1329         }
1330
1331         unlink_op = (new_dir == obj->my_dev->unlinked_dir);
1332         del_op = (new_dir == obj->my_dev->del_dir);
1333
1334         existing_target = yaffs_find_by_name(new_dir, new_name);
1335
1336         /* If the object is a file going into the unlinked directory,
1337          *   then it is OK to just stuff it in since duplicate names are OK.
1338          *   else only proceed if the new name does not exist and we're putting
1339          *   it into a directory.
1340          */
1341         if (!(unlink_op || del_op || force ||
1342               shadows > 0 || !existing_target) ||
1343               new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
1344                 return YAFFS_FAIL;
1345
1346         yaffs_set_obj_name(obj, new_name);
1347         obj->dirty = 1;
1348         yaffs_add_obj_to_dir(new_dir, obj);
1349
1350         if (unlink_op)
1351                 obj->unlinked = 1;
1352
1353         /* If it is a deletion then we mark it as a shrink for gc  */
1354         if (yaffs_update_oh(obj, new_name, 0, del_op, shadows, NULL) >= 0)
1355                 return YAFFS_OK;
1356
1357         return YAFFS_FAIL;
1358 }
1359
1360 /*------------------------ Short Operations Cache ------------------------------
1361  *   In many situations where there is no high level buffering  a lot of
1362  *   reads might be short sequential reads, and a lot of writes may be short
1363  *   sequential writes. eg. scanning/writing a jpeg file.
1364  *   In these cases, a short read/write cache can provide a huge perfomance
1365  *   benefit with dumb-as-a-rock code.
1366  *   In Linux, the page cache provides read buffering and the short op cache
1367  *   provides write buffering.
1368  *
1369  *   There are a small number (~10) of cache chunks per device so that we don't
1370  *   need a very intelligent search.
1371  */
1372
1373 static int yaffs_obj_cache_dirty(struct yaffs_obj *obj)
1374 {
1375         struct yaffs_dev *dev = obj->my_dev;
1376         int i;
1377         struct yaffs_cache *cache;
1378         int n_caches = obj->my_dev->param.n_caches;
1379
1380         for (i = 0; i < n_caches; i++) {
1381                 cache = &dev->cache[i];
1382                 if (cache->object == obj && cache->dirty)
1383                         return 1;
1384         }
1385
1386         return 0;
1387 }
1388
1389 static void yaffs_flush_file_cache(struct yaffs_obj *obj)
1390 {
1391         struct yaffs_dev *dev = obj->my_dev;
1392         int lowest = -99;       /* Stop compiler whining. */
1393         int i;
1394         struct yaffs_cache *cache;
1395         int chunk_written = 0;
1396         int n_caches = obj->my_dev->param.n_caches;
1397
1398         if (n_caches < 1)
1399                 return;
1400         do {
1401                 cache = NULL;
1402
1403                 /* Find the lowest dirty chunk for this object */
1404                 for (i = 0; i < n_caches; i++) {
1405                         if (dev->cache[i].object == obj &&
1406                             dev->cache[i].dirty) {
1407                                 if (!cache ||
1408                                     dev->cache[i].chunk_id < lowest) {
1409                                         cache = &dev->cache[i];
1410                                         lowest = cache->chunk_id;
1411                                 }
1412                         }
1413                 }
1414
1415                 if (cache && !cache->locked) {
1416                         /* Write it out and free it up */
1417                         chunk_written =
1418                             yaffs_wr_data_obj(cache->object,
1419                                               cache->chunk_id,
1420                                               cache->data,
1421                                               cache->n_bytes, 1);
1422                         cache->dirty = 0;
1423                         cache->object = NULL;
1424                 }
1425         } while (cache && chunk_written > 0);
1426
1427         if (cache)
1428                 /* Hoosterman, disk full while writing cache out. */
1429                 yaffs_trace(YAFFS_TRACE_ERROR,
1430                         "yaffs tragedy: no space during cache write");
1431 }
1432
1433 /*yaffs_flush_whole_cache(dev)
1434  *
1435  *
1436  */
1437
1438 void yaffs_flush_whole_cache(struct yaffs_dev *dev)
1439 {
1440         struct yaffs_obj *obj;
1441         int n_caches = dev->param.n_caches;
1442         int i;
1443
1444         /* Find a dirty object in the cache and flush it...
1445          * until there are no further dirty objects.
1446          */
1447         do {
1448                 obj = NULL;
1449                 for (i = 0; i < n_caches && !obj; i++) {
1450                         if (dev->cache[i].object && dev->cache[i].dirty)
1451                                 obj = dev->cache[i].object;
1452                 }
1453                 if (obj)
1454                         yaffs_flush_file_cache(obj);
1455         } while (obj);
1456
1457 }
1458
1459 /* Grab us a cache chunk for use.
1460  * First look for an empty one.
1461  * Then look for the least recently used non-dirty one.
1462  * Then look for the least recently used dirty one...., flush and look again.
1463  */
1464 static struct yaffs_cache *yaffs_grab_chunk_worker(struct yaffs_dev *dev)
1465 {
1466         int i;
1467
1468         if (dev->param.n_caches > 0) {
1469                 for (i = 0; i < dev->param.n_caches; i++) {
1470                         if (!dev->cache[i].object)
1471                                 return &dev->cache[i];
1472                 }
1473         }
1474         return NULL;
1475 }
1476
1477 static struct yaffs_cache *yaffs_grab_chunk_cache(struct yaffs_dev *dev)
1478 {
1479         struct yaffs_cache *cache;
1480         struct yaffs_obj *the_obj;
1481         int usage;
1482         int i;
1483         int pushout;
1484
1485         if (dev->param.n_caches < 1)
1486                 return NULL;
1487
1488         /* Try find a non-dirty one... */
1489
1490         cache = yaffs_grab_chunk_worker(dev);
1491
1492         if (!cache) {
1493                 /* They were all dirty, find the LRU object and flush
1494                  * its cache, then  find again.
1495                  * NB what's here is not very accurate,
1496                  * we actually flush the object with the LRU chunk.
1497                  */
1498
1499                 /* With locking we can't assume we can use entry zero,
1500                  * Set the_obj to a valid pointer for Coverity. */
1501                 the_obj = dev->cache[0].object;
1502                 usage = -1;
1503                 cache = NULL;
1504                 pushout = -1;
1505
1506                 for (i = 0; i < dev->param.n_caches; i++) {
1507                         if (dev->cache[i].object &&
1508                             !dev->cache[i].locked &&
1509                             (dev->cache[i].last_use < usage ||
1510                             !cache)) {
1511                                 usage = dev->cache[i].last_use;
1512                                 the_obj = dev->cache[i].object;
1513                                 cache = &dev->cache[i];
1514                                 pushout = i;
1515                         }
1516                 }
1517
1518                 if (!cache || cache->dirty) {
1519                         /* Flush and try again */
1520                         yaffs_flush_file_cache(the_obj);
1521                         cache = yaffs_grab_chunk_worker(dev);
1522                 }
1523         }
1524         return cache;
1525 }
1526
1527 /* Find a cached chunk */
1528 static struct yaffs_cache *yaffs_find_chunk_cache(const struct yaffs_obj *obj,
1529                                                   int chunk_id)
1530 {
1531         struct yaffs_dev *dev = obj->my_dev;
1532         int i;
1533
1534         if (dev->param.n_caches < 1)
1535                 return NULL;
1536
1537         for (i = 0; i < dev->param.n_caches; i++) {
1538                 if (dev->cache[i].object == obj &&
1539                     dev->cache[i].chunk_id == chunk_id) {
1540                         dev->cache_hits++;
1541
1542                         return &dev->cache[i];
1543                 }
1544         }
1545         return NULL;
1546 }
1547
1548 /* Mark the chunk for the least recently used algorithym */
1549 static void yaffs_use_cache(struct yaffs_dev *dev, struct yaffs_cache *cache,
1550                             int is_write)
1551 {
1552         int i;
1553
1554         if (dev->param.n_caches < 1)
1555                 return;
1556
1557         if (dev->cache_last_use < 0 ||
1558                 dev->cache_last_use > 100000000) {
1559                 /* Reset the cache usages */
1560                 for (i = 1; i < dev->param.n_caches; i++)
1561                         dev->cache[i].last_use = 0;
1562
1563                 dev->cache_last_use = 0;
1564         }
1565         dev->cache_last_use++;
1566         cache->last_use = dev->cache_last_use;
1567
1568         if (is_write)
1569                 cache->dirty = 1;
1570 }
1571
1572 /* Invalidate a single cache page.
1573  * Do this when a whole page gets written,
1574  * ie the short cache for this page is no longer valid.
1575  */
1576 static void yaffs_invalidate_chunk_cache(struct yaffs_obj *object, int chunk_id)
1577 {
1578         struct yaffs_cache *cache;
1579
1580         if (object->my_dev->param.n_caches > 0) {
1581                 cache = yaffs_find_chunk_cache(object, chunk_id);
1582
1583                 if (cache)
1584                         cache->object = NULL;
1585         }
1586 }
1587
1588 /* Invalidate all the cache pages associated with this object
1589  * Do this whenever ther file is deleted or resized.
1590  */
1591 static void yaffs_invalidate_whole_cache(struct yaffs_obj *in)
1592 {
1593         int i;
1594         struct yaffs_dev *dev = in->my_dev;
1595
1596         if (dev->param.n_caches > 0) {
1597                 /* Invalidate it. */
1598                 for (i = 0; i < dev->param.n_caches; i++) {
1599                         if (dev->cache[i].object == in)
1600                                 dev->cache[i].object = NULL;
1601                 }
1602         }
1603 }
1604
1605 static void yaffs_unhash_obj(struct yaffs_obj *obj)
1606 {
1607         int bucket;
1608         struct yaffs_dev *dev = obj->my_dev;
1609
1610         /* If it is still linked into the bucket list, free from the list */
1611         if (!list_empty(&obj->hash_link)) {
1612                 list_del_init(&obj->hash_link);
1613                 bucket = yaffs_hash_fn(obj->obj_id);
1614                 dev->obj_bucket[bucket].count--;
1615         }
1616 }
1617
1618 /*  FreeObject frees up a Object and puts it back on the free list */
1619 static void yaffs_free_obj(struct yaffs_obj *obj)
1620 {
1621         struct yaffs_dev *dev;
1622
1623         if (!obj) {
1624                 BUG();
1625                 return;
1626         }
1627         dev = obj->my_dev;
1628         yaffs_trace(YAFFS_TRACE_OS, "FreeObject %p inode %p",
1629                 obj, obj->my_inode);
1630         if (obj->parent)
1631                 BUG();
1632         if (!list_empty(&obj->siblings))
1633                 BUG();
1634
1635         if (obj->my_inode) {
1636                 /* We're still hooked up to a cached inode.
1637                  * Don't delete now, but mark for later deletion
1638                  */
1639                 obj->defered_free = 1;
1640                 return;
1641         }
1642
1643         yaffs_unhash_obj(obj);
1644
1645         yaffs_free_raw_obj(dev, obj);
1646         dev->n_obj--;
1647         dev->checkpoint_blocks_required = 0;    /* force recalculation */
1648 }
1649
1650 void yaffs_handle_defered_free(struct yaffs_obj *obj)
1651 {
1652         if (obj->defered_free)
1653                 yaffs_free_obj(obj);
1654 }
1655
1656 static int yaffs_generic_obj_del(struct yaffs_obj *in)
1657 {
1658         /* Iinvalidate the file's data in the cache, without flushing. */
1659         yaffs_invalidate_whole_cache(in);
1660
1661         if (in->my_dev->param.is_yaffs2 && in->parent != in->my_dev->del_dir) {
1662                 /* Move to unlinked directory so we have a deletion record */
1663                 yaffs_change_obj_name(in, in->my_dev->del_dir, _Y("deleted"), 0,
1664                                       0);
1665         }
1666
1667         yaffs_remove_obj_from_dir(in);
1668         yaffs_chunk_del(in->my_dev, in->hdr_chunk, 1, __LINE__);
1669         in->hdr_chunk = 0;
1670
1671         yaffs_free_obj(in);
1672         return YAFFS_OK;
1673
1674 }
1675
1676 static void yaffs_soft_del_file(struct yaffs_obj *obj)
1677 {
1678         if (!obj->deleted ||
1679             obj->variant_type != YAFFS_OBJECT_TYPE_FILE ||
1680             obj->soft_del)
1681                 return;
1682
1683         if (obj->n_data_chunks <= 0) {
1684                 /* Empty file with no duplicate object headers,
1685                  * just delete it immediately */
1686                 yaffs_free_tnode(obj->my_dev, obj->variant.file_variant.top);
1687                 obj->variant.file_variant.top = NULL;
1688                 yaffs_trace(YAFFS_TRACE_TRACING,
1689                         "yaffs: Deleting empty file %d",
1690                         obj->obj_id);
1691                 yaffs_generic_obj_del(obj);
1692         } else {
1693                 yaffs_soft_del_worker(obj,
1694                                       obj->variant.file_variant.top,
1695                                       obj->variant.
1696                                       file_variant.top_level, 0);
1697                 obj->soft_del = 1;
1698         }
1699 }
1700
1701 /* Pruning removes any part of the file structure tree that is beyond the
1702  * bounds of the file (ie that does not point to chunks).
1703  *
1704  * A file should only get pruned when its size is reduced.
1705  *
1706  * Before pruning, the chunks must be pulled from the tree and the
1707  * level 0 tnode entries must be zeroed out.
1708  * Could also use this for file deletion, but that's probably better handled
1709  * by a special case.
1710  *
1711  * This function is recursive. For levels > 0 the function is called again on
1712  * any sub-tree. For level == 0 we just check if the sub-tree has data.
1713  * If there is no data in a subtree then it is pruned.
1714  */
1715
1716 static struct yaffs_tnode *yaffs_prune_worker(struct yaffs_dev *dev,
1717                                               struct yaffs_tnode *tn, u32 level,
1718                                               int del0)
1719 {
1720         int i;
1721         int has_data;
1722
1723         if (!tn)
1724                 return tn;
1725
1726         has_data = 0;
1727
1728         if (level > 0) {
1729                 for (i = 0; i < YAFFS_NTNODES_INTERNAL; i++) {
1730                         if (tn->internal[i]) {
1731                                 tn->internal[i] =
1732                                     yaffs_prune_worker(dev,
1733                                                 tn->internal[i],
1734                                                 level - 1,
1735                                                 (i == 0) ? del0 : 1);
1736                         }
1737
1738                         if (tn->internal[i])
1739                                 has_data++;
1740                 }
1741         } else {
1742                 int tnode_size_u32 = dev->tnode_size / sizeof(u32);
1743                 u32 *map = (u32 *) tn;
1744
1745                 for (i = 0; !has_data && i < tnode_size_u32; i++) {
1746                         if (map[i])
1747                                 has_data++;
1748                 }
1749         }
1750
1751         if (has_data == 0 && del0) {
1752                 /* Free and return NULL */
1753                 yaffs_free_tnode(dev, tn);
1754                 tn = NULL;
1755         }
1756         return tn;
1757 }
1758
1759 static int yaffs_prune_tree(struct yaffs_dev *dev,
1760                             struct yaffs_file_var *file_struct)
1761 {
1762         int i;
1763         int has_data;
1764         int done = 0;
1765         struct yaffs_tnode *tn;
1766
1767         if (file_struct->top_level < 1)
1768                 return YAFFS_OK;
1769
1770         file_struct->top =
1771            yaffs_prune_worker(dev, file_struct->top, file_struct->top_level, 0);
1772
1773         /* Now we have a tree with all the non-zero branches NULL but
1774          * the height is the same as it was.
1775          * Let's see if we can trim internal tnodes to shorten the tree.
1776          * We can do this if only the 0th element in the tnode is in use
1777          * (ie all the non-zero are NULL)
1778          */
1779
1780         while (file_struct->top_level && !done) {
1781                 tn = file_struct->top;
1782
1783                 has_data = 0;
1784                 for (i = 1; i < YAFFS_NTNODES_INTERNAL; i++) {
1785                         if (tn->internal[i])
1786                                 has_data++;
1787                 }
1788
1789                 if (!has_data) {
1790                         file_struct->top = tn->internal[0];
1791                         file_struct->top_level--;
1792                         yaffs_free_tnode(dev, tn);
1793                 } else {
1794                         done = 1;
1795                 }
1796         }
1797
1798         return YAFFS_OK;
1799 }
1800
1801 /*-------------------- End of File Structure functions.-------------------*/
1802
1803 /* alloc_empty_obj gets us a clean Object.*/
1804 static struct yaffs_obj *yaffs_alloc_empty_obj(struct yaffs_dev *dev)
1805 {
1806         struct yaffs_obj *obj = yaffs_alloc_raw_obj(dev);
1807
1808         if (!obj)
1809                 return obj;
1810
1811         dev->n_obj++;
1812
1813         /* Now sweeten it up... */
1814
1815         memset(obj, 0, sizeof(struct yaffs_obj));
1816         obj->being_created = 1;
1817
1818         obj->my_dev = dev;
1819         obj->hdr_chunk = 0;
1820         obj->variant_type = YAFFS_OBJECT_TYPE_UNKNOWN;
1821         INIT_LIST_HEAD(&(obj->hard_links));
1822         INIT_LIST_HEAD(&(obj->hash_link));
1823         INIT_LIST_HEAD(&obj->siblings);
1824
1825         /* Now make the directory sane */
1826         if (dev->root_dir) {
1827                 obj->parent = dev->root_dir;
1828                 list_add(&(obj->siblings),
1829                          &dev->root_dir->variant.dir_variant.children);
1830         }
1831
1832         /* Add it to the lost and found directory.
1833          * NB Can't put root or lost-n-found in lost-n-found so
1834          * check if lost-n-found exists first
1835          */
1836         if (dev->lost_n_found)
1837                 yaffs_add_obj_to_dir(dev->lost_n_found, obj);
1838
1839         obj->being_created = 0;
1840
1841         dev->checkpoint_blocks_required = 0;    /* force recalculation */
1842
1843         return obj;
1844 }
1845
1846 static int yaffs_find_nice_bucket(struct yaffs_dev *dev)
1847 {
1848         int i;
1849         int l = 999;
1850         int lowest = 999999;
1851
1852         /* Search for the shortest list or one that
1853          * isn't too long.
1854          */
1855
1856         for (i = 0; i < 10 && lowest > 4; i++) {
1857                 dev->bucket_finder++;
1858                 dev->bucket_finder %= YAFFS_NOBJECT_BUCKETS;
1859                 if (dev->obj_bucket[dev->bucket_finder].count < lowest) {
1860                         lowest = dev->obj_bucket[dev->bucket_finder].count;
1861                         l = dev->bucket_finder;
1862                 }
1863         }
1864
1865         return l;
1866 }
1867
1868 static int yaffs_new_obj_id(struct yaffs_dev *dev)
1869 {
1870         int bucket = yaffs_find_nice_bucket(dev);
1871         int found = 0;
1872         struct list_head *i;
1873         u32 n = (u32) bucket;
1874
1875         /* Now find an object value that has not already been taken
1876          * by scanning the list.
1877          */
1878
1879         while (!found) {
1880                 found = 1;
1881                 n += YAFFS_NOBJECT_BUCKETS;
1882                 if (1 || dev->obj_bucket[bucket].count > 0) {
1883                         list_for_each(i, &dev->obj_bucket[bucket].list) {
1884                                 /* If there is already one in the list */
1885                                 if (i && list_entry(i, struct yaffs_obj,
1886                                                     hash_link)->obj_id == n) {
1887                                         found = 0;
1888                                 }
1889                         }
1890                 }
1891         }
1892         return n;
1893 }
1894
1895 static void yaffs_hash_obj(struct yaffs_obj *in)
1896 {
1897         int bucket = yaffs_hash_fn(in->obj_id);
1898         struct yaffs_dev *dev = in->my_dev;
1899
1900         list_add(&in->hash_link, &dev->obj_bucket[bucket].list);
1901         dev->obj_bucket[bucket].count++;
1902 }
1903
1904 struct yaffs_obj *yaffs_find_by_number(struct yaffs_dev *dev, u32 number)
1905 {
1906         int bucket = yaffs_hash_fn(number);
1907         struct list_head *i;
1908         struct yaffs_obj *in;
1909
1910         list_for_each(i, &dev->obj_bucket[bucket].list) {
1911                 /* Look if it is in the list */
1912                 in = list_entry(i, struct yaffs_obj, hash_link);
1913                 if (in->obj_id == number) {
1914                         /* Don't show if it is defered free */
1915                         if (in->defered_free)
1916                                 return NULL;
1917                         return in;
1918                 }
1919         }
1920
1921         return NULL;
1922 }
1923
1924 struct yaffs_obj *yaffs_new_obj(struct yaffs_dev *dev, int number,
1925                                 enum yaffs_obj_type type)
1926 {
1927         struct yaffs_obj *the_obj = NULL;
1928         struct yaffs_tnode *tn = NULL;
1929
1930         if (number < 0)
1931                 number = yaffs_new_obj_id(dev);
1932
1933         if (type == YAFFS_OBJECT_TYPE_FILE) {
1934                 tn = yaffs_get_tnode(dev);
1935                 if (!tn)
1936                         return NULL;
1937         }
1938
1939         the_obj = yaffs_alloc_empty_obj(dev);
1940         if (!the_obj) {
1941                 if (tn)
1942                         yaffs_free_tnode(dev, tn);
1943                 return NULL;
1944         }
1945
1946         the_obj->fake = 0;
1947         the_obj->rename_allowed = 1;
1948         the_obj->unlink_allowed = 1;
1949         the_obj->obj_id = number;
1950         yaffs_hash_obj(the_obj);
1951         the_obj->variant_type = type;
1952         yaffs_load_current_time(the_obj, 1, 1);
1953
1954         switch (type) {
1955         case YAFFS_OBJECT_TYPE_FILE:
1956                 the_obj->variant.file_variant.file_size = 0;
1957                 the_obj->variant.file_variant.scanned_size = 0;
1958                 the_obj->variant.file_variant.shrink_size = ~0; /* max */
1959                 the_obj->variant.file_variant.top_level = 0;
1960                 the_obj->variant.file_variant.top = tn;
1961                 break;
1962         case YAFFS_OBJECT_TYPE_DIRECTORY:
1963                 INIT_LIST_HEAD(&the_obj->variant.dir_variant.children);
1964                 INIT_LIST_HEAD(&the_obj->variant.dir_variant.dirty);
1965                 break;
1966         case YAFFS_OBJECT_TYPE_SYMLINK:
1967         case YAFFS_OBJECT_TYPE_HARDLINK:
1968         case YAFFS_OBJECT_TYPE_SPECIAL:
1969                 /* No action required */
1970                 break;
1971         case YAFFS_OBJECT_TYPE_UNKNOWN:
1972                 /* todo this should not happen */
1973                 break;
1974         }
1975         return the_obj;
1976 }
1977
1978 static struct yaffs_obj *yaffs_create_fake_dir(struct yaffs_dev *dev,
1979                                                int number, u32 mode)
1980 {
1981
1982         struct yaffs_obj *obj =
1983             yaffs_new_obj(dev, number, YAFFS_OBJECT_TYPE_DIRECTORY);
1984
1985         if (!obj)
1986                 return NULL;
1987
1988         obj->fake = 1;  /* it is fake so it might not use NAND */
1989         obj->rename_allowed = 0;
1990         obj->unlink_allowed = 0;
1991         obj->deleted = 0;
1992         obj->unlinked = 0;
1993         obj->yst_mode = mode;
1994         obj->my_dev = dev;
1995         obj->hdr_chunk = 0;     /* Not a valid chunk. */
1996         return obj;
1997
1998 }
1999
2000
2001 static void yaffs_init_tnodes_and_objs(struct yaffs_dev *dev)
2002 {
2003         int i;
2004
2005         dev->n_obj = 0;
2006         dev->n_tnodes = 0;
2007         yaffs_init_raw_tnodes_and_objs(dev);
2008
2009         for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
2010                 INIT_LIST_HEAD(&dev->obj_bucket[i].list);
2011                 dev->obj_bucket[i].count = 0;
2012         }
2013 }
2014
2015 struct yaffs_obj *yaffs_find_or_create_by_number(struct yaffs_dev *dev,
2016                                                  int number,
2017                                                  enum yaffs_obj_type type)
2018 {
2019         struct yaffs_obj *the_obj = NULL;
2020
2021         if (number > 0)
2022                 the_obj = yaffs_find_by_number(dev, number);
2023
2024         if (!the_obj)
2025                 the_obj = yaffs_new_obj(dev, number, type);
2026
2027         return the_obj;
2028
2029 }
2030
2031 YCHAR *yaffs_clone_str(const YCHAR *str)
2032 {
2033         YCHAR *new_str = NULL;
2034         int len;
2035
2036         if (!str)
2037                 str = _Y("");
2038
2039         len = strnlen(str, YAFFS_MAX_ALIAS_LENGTH);
2040         new_str = kmalloc((len + 1) * sizeof(YCHAR), GFP_NOFS);
2041         if (new_str) {
2042                 strncpy(new_str, str, len);
2043                 new_str[len] = 0;
2044         }
2045         return new_str;
2046
2047 }
2048 /*
2049  *yaffs_update_parent() handles fixing a directories mtime and ctime when a new
2050  * link (ie. name) is created or deleted in the directory.
2051  *
2052  * ie.
2053  *   create dir/a : update dir's mtime/ctime
2054  *   rm dir/a:   update dir's mtime/ctime
2055  *   modify dir/a: don't update dir's mtimme/ctime
2056  *
2057  * This can be handled immediately or defered. Defering helps reduce the number
2058  * of updates when many files in a directory are changed within a brief period.
2059  *
2060  * If the directory updating is defered then yaffs_update_dirty_dirs must be
2061  * called periodically.
2062  */
2063
2064 static void yaffs_update_parent(struct yaffs_obj *obj)
2065 {
2066         struct yaffs_dev *dev;
2067
2068         if (!obj)
2069                 return;
2070         dev = obj->my_dev;
2071         obj->dirty = 1;
2072         yaffs_load_current_time(obj, 0, 1);
2073         if (dev->param.defered_dir_update) {
2074                 struct list_head *link = &obj->variant.dir_variant.dirty;
2075
2076                 if (list_empty(link)) {
2077                         list_add(link, &dev->dirty_dirs);
2078                         yaffs_trace(YAFFS_TRACE_BACKGROUND,
2079                           "Added object %d to dirty directories",
2080                            obj->obj_id);
2081                 }
2082
2083         } else {
2084                 yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
2085         }
2086 }
2087
2088 void yaffs_update_dirty_dirs(struct yaffs_dev *dev)
2089 {
2090         struct list_head *link;
2091         struct yaffs_obj *obj;
2092         struct yaffs_dir_var *d_s;
2093         union yaffs_obj_var *o_v;
2094
2095         yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update dirty directories");
2096
2097         while (!list_empty(&dev->dirty_dirs)) {
2098                 link = dev->dirty_dirs.next;
2099                 list_del_init(link);
2100
2101                 d_s = list_entry(link, struct yaffs_dir_var, dirty);
2102                 o_v = list_entry(d_s, union yaffs_obj_var, dir_variant);
2103                 obj = list_entry(o_v, struct yaffs_obj, variant);
2104
2105                 yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update directory %d",
2106                         obj->obj_id);
2107
2108                 if (obj->dirty)
2109                         yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
2110         }
2111 }
2112
2113 /*
2114  * Mknod (create) a new object.
2115  * equiv_obj only has meaning for a hard link;
2116  * alias_str only has meaning for a symlink.
2117  * rdev only has meaning for devices (a subset of special objects)
2118  */
2119
2120 static struct yaffs_obj *yaffs_create_obj(enum yaffs_obj_type type,
2121                                           struct yaffs_obj *parent,
2122                                           const YCHAR *name,
2123                                           u32 mode,
2124                                           u32 uid,
2125                                           u32 gid,
2126                                           struct yaffs_obj *equiv_obj,
2127                                           const YCHAR *alias_str, u32 rdev)
2128 {
2129         struct yaffs_obj *in;
2130         YCHAR *str = NULL;
2131         struct yaffs_dev *dev = parent->my_dev;
2132
2133         /* Check if the entry exists.
2134          * If it does then fail the call since we don't want a dup. */
2135         if (yaffs_find_by_name(parent, name))
2136                 return NULL;
2137
2138         if (type == YAFFS_OBJECT_TYPE_SYMLINK) {
2139                 str = yaffs_clone_str(alias_str);
2140                 if (!str)
2141                         return NULL;
2142         }
2143
2144         in = yaffs_new_obj(dev, -1, type);
2145
2146         if (!in) {
2147                 kfree(str);
2148                 return NULL;
2149         }
2150
2151         in->hdr_chunk = 0;
2152         in->valid = 1;
2153         in->variant_type = type;
2154
2155         in->yst_mode = mode;
2156
2157         yaffs_attribs_init(in, gid, uid, rdev);
2158
2159         in->n_data_chunks = 0;
2160
2161         yaffs_set_obj_name(in, name);
2162         in->dirty = 1;
2163
2164         yaffs_add_obj_to_dir(parent, in);
2165
2166         in->my_dev = parent->my_dev;
2167
2168         switch (type) {
2169         case YAFFS_OBJECT_TYPE_SYMLINK:
2170                 in->variant.symlink_variant.alias = str;
2171                 break;
2172         case YAFFS_OBJECT_TYPE_HARDLINK:
2173                 in->variant.hardlink_variant.equiv_obj = equiv_obj;
2174                 in->variant.hardlink_variant.equiv_id = equiv_obj->obj_id;
2175                 list_add(&in->hard_links, &equiv_obj->hard_links);
2176                 break;
2177         case YAFFS_OBJECT_TYPE_FILE:
2178         case YAFFS_OBJECT_TYPE_DIRECTORY:
2179         case YAFFS_OBJECT_TYPE_SPECIAL:
2180         case YAFFS_OBJECT_TYPE_UNKNOWN:
2181                 /* do nothing */
2182                 break;
2183         }
2184
2185         if (yaffs_update_oh(in, name, 0, 0, 0, NULL) < 0) {
2186                 /* Could not create the object header, fail */
2187                 yaffs_del_obj(in);
2188                 in = NULL;
2189         }
2190
2191         if (in)
2192                 yaffs_update_parent(parent);
2193
2194         return in;
2195 }
2196
2197 struct yaffs_obj *yaffs_create_file(struct yaffs_obj *parent,
2198                                     const YCHAR *name, u32 mode, u32 uid,
2199                                     u32 gid)
2200 {
2201         return yaffs_create_obj(YAFFS_OBJECT_TYPE_FILE, parent, name, mode,
2202                                 uid, gid, NULL, NULL, 0);
2203 }
2204
2205 struct yaffs_obj *yaffs_create_dir(struct yaffs_obj *parent, const YCHAR *name,
2206                                    u32 mode, u32 uid, u32 gid)
2207 {
2208         return yaffs_create_obj(YAFFS_OBJECT_TYPE_DIRECTORY, parent, name,
2209                                 mode, uid, gid, NULL, NULL, 0);
2210 }
2211
2212 struct yaffs_obj *yaffs_create_special(struct yaffs_obj *parent,
2213                                        const YCHAR *name, u32 mode, u32 uid,
2214                                        u32 gid, u32 rdev)
2215 {
2216         return yaffs_create_obj(YAFFS_OBJECT_TYPE_SPECIAL, parent, name, mode,
2217                                 uid, gid, NULL, NULL, rdev);
2218 }
2219
2220 struct yaffs_obj *yaffs_create_symlink(struct yaffs_obj *parent,
2221                                        const YCHAR *name, u32 mode, u32 uid,
2222                                        u32 gid, const YCHAR *alias)
2223 {
2224         return yaffs_create_obj(YAFFS_OBJECT_TYPE_SYMLINK, parent, name, mode,
2225                                 uid, gid, NULL, alias, 0);
2226 }
2227
2228 /* yaffs_link_obj returns the object id of the equivalent object.*/
2229 struct yaffs_obj *yaffs_link_obj(struct yaffs_obj *parent, const YCHAR * name,
2230                                  struct yaffs_obj *equiv_obj)
2231 {
2232         /* Get the real object in case we were fed a hard link obj */
2233         equiv_obj = yaffs_get_equivalent_obj(equiv_obj);
2234
2235         if (yaffs_create_obj(YAFFS_OBJECT_TYPE_HARDLINK,
2236                         parent, name, 0, 0, 0,
2237                         equiv_obj, NULL, 0))
2238                 return equiv_obj;
2239
2240         return NULL;
2241
2242 }
2243
2244
2245
2246 /*---------------------- Block Management and Page Allocation -------------*/
2247
2248 static void yaffs_deinit_blocks(struct yaffs_dev *dev)
2249 {
2250         if (dev->block_info_alt && dev->block_info)
2251                 vfree(dev->block_info);
2252         else
2253                 kfree(dev->block_info);
2254
2255         dev->block_info_alt = 0;
2256
2257         dev->block_info = NULL;
2258
2259         if (dev->chunk_bits_alt && dev->chunk_bits)
2260                 vfree(dev->chunk_bits);
2261         else
2262                 kfree(dev->chunk_bits);
2263         dev->chunk_bits_alt = 0;
2264         dev->chunk_bits = NULL;
2265 }
2266
2267 static int yaffs_init_blocks(struct yaffs_dev *dev)
2268 {
2269         int n_blocks = dev->internal_end_block - dev->internal_start_block + 1;
2270
2271         dev->block_info = NULL;
2272         dev->chunk_bits = NULL;
2273         dev->alloc_block = -1;  /* force it to get a new one */
2274
2275         /* If the first allocation strategy fails, thry the alternate one */
2276         dev->block_info =
2277                 kmalloc(n_blocks * sizeof(struct yaffs_block_info), GFP_NOFS);
2278         if (!dev->block_info) {
2279                 dev->block_info =
2280                     vmalloc(n_blocks * sizeof(struct yaffs_block_info));
2281                 dev->block_info_alt = 1;
2282         } else {
2283                 dev->block_info_alt = 0;
2284         }
2285
2286         if (!dev->block_info)
2287                 goto alloc_error;
2288
2289         /* Set up dynamic blockinfo stuff. Round up bytes. */
2290         dev->chunk_bit_stride = (dev->param.chunks_per_block + 7) / 8;
2291         dev->chunk_bits =
2292                 kmalloc(dev->chunk_bit_stride * n_blocks, GFP_NOFS);
2293         if (!dev->chunk_bits) {
2294                 dev->chunk_bits =
2295                     vmalloc(dev->chunk_bit_stride * n_blocks);
2296                 dev->chunk_bits_alt = 1;
2297         } else {
2298                 dev->chunk_bits_alt = 0;
2299         }
2300         if (!dev->chunk_bits)
2301                 goto alloc_error;
2302
2303
2304         memset(dev->block_info, 0, n_blocks * sizeof(struct yaffs_block_info));
2305         memset(dev->chunk_bits, 0, dev->chunk_bit_stride * n_blocks);
2306         return YAFFS_OK;
2307
2308 alloc_error:
2309         yaffs_deinit_blocks(dev);
2310         return YAFFS_FAIL;
2311 }
2312
2313
2314 void yaffs_block_became_dirty(struct yaffs_dev *dev, int block_no)
2315 {
2316         struct yaffs_block_info *bi = yaffs_get_block_info(dev, block_no);
2317         int erased_ok = 0;
2318         int i;
2319
2320         /* If the block is still healthy erase it and mark as clean.
2321          * If the block has had a data failure, then retire it.
2322          */
2323
2324         yaffs_trace(YAFFS_TRACE_GC | YAFFS_TRACE_ERASE,
2325                 "yaffs_block_became_dirty block %d state %d %s",
2326                 block_no, bi->block_state,
2327                 (bi->needs_retiring) ? "needs retiring" : "");
2328
2329         yaffs2_clear_oldest_dirty_seq(dev, bi);
2330
2331         bi->block_state = YAFFS_BLOCK_STATE_DIRTY;
2332
2333         /* If this is the block being garbage collected then stop gc'ing */
2334         if (block_no == dev->gc_block)
2335                 dev->gc_block = 0;
2336
2337         /* If this block is currently the best candidate for gc
2338          * then drop as a candidate */
2339         if (block_no == dev->gc_dirtiest) {
2340                 dev->gc_dirtiest = 0;
2341                 dev->gc_pages_in_use = 0;
2342         }
2343
2344         if (!bi->needs_retiring) {
2345                 yaffs2_checkpt_invalidate(dev);
2346                 erased_ok = yaffs_erase_block(dev, block_no);
2347                 if (!erased_ok) {
2348                         dev->n_erase_failures++;
2349                         yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2350                           "**>> Erasure failed %d", block_no);
2351                 }
2352         }
2353
2354         /* Verify erasure if needed */
2355         if (erased_ok &&
2356             ((yaffs_trace_mask & YAFFS_TRACE_ERASE) ||
2357              !yaffs_skip_verification(dev))) {
2358                 for (i = 0; i < dev->param.chunks_per_block; i++) {
2359                         if (!yaffs_check_chunk_erased(dev,
2360                                 block_no * dev->param.chunks_per_block + i)) {
2361                                 yaffs_trace(YAFFS_TRACE_ERROR,
2362                                         ">>Block %d erasure supposedly OK, but chunk %d not erased",
2363                                         block_no, i);
2364                         }
2365                 }
2366         }
2367
2368         if (!erased_ok) {
2369                 /* We lost a block of free space */
2370                 dev->n_free_chunks -= dev->param.chunks_per_block;
2371                 yaffs_retire_block(dev, block_no);
2372                 yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2373                         "**>> Block %d retired", block_no);
2374                 return;
2375         }
2376
2377         /* Clean it up... */
2378         bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
2379         bi->seq_number = 0;
2380         dev->n_erased_blocks++;
2381         bi->pages_in_use = 0;
2382         bi->soft_del_pages = 0;
2383         bi->has_shrink_hdr = 0;
2384         bi->skip_erased_check = 1;      /* Clean, so no need to check */
2385         bi->gc_prioritise = 0;
2386         yaffs_clear_chunk_bits(dev, block_no);
2387
2388         yaffs_trace(YAFFS_TRACE_ERASE, "Erased block %d", block_no);
2389 }
2390
2391 static inline int yaffs_gc_process_chunk(struct yaffs_dev *dev,
2392                                         struct yaffs_block_info *bi,
2393                                         int old_chunk, u8 *buffer)
2394 {
2395         int new_chunk;
2396         int mark_flash = 1;
2397         struct yaffs_ext_tags tags;
2398         struct yaffs_obj *object;
2399         int matching_chunk;
2400         int ret_val = YAFFS_OK;
2401
2402         memset(&tags, 0, sizeof(tags));
2403         yaffs_rd_chunk_tags_nand(dev, old_chunk,
2404                                  buffer, &tags);
2405         object = yaffs_find_by_number(dev, tags.obj_id);
2406
2407         yaffs_trace(YAFFS_TRACE_GC_DETAIL,
2408                 "Collecting chunk in block %d, %d %d %d ",
2409                 dev->gc_chunk, tags.obj_id,
2410                 tags.chunk_id, tags.n_bytes);
2411
2412         if (object && !yaffs_skip_verification(dev)) {
2413                 if (tags.chunk_id == 0)
2414                         matching_chunk =
2415                             object->hdr_chunk;
2416                 else if (object->soft_del)
2417                         /* Defeat the test */
2418                         matching_chunk = old_chunk;
2419                 else
2420                         matching_chunk =
2421                             yaffs_find_chunk_in_file
2422                             (object, tags.chunk_id,
2423                              NULL);
2424
2425                 if (old_chunk != matching_chunk)
2426                         yaffs_trace(YAFFS_TRACE_ERROR,
2427                                 "gc: page in gc mismatch: %d %d %d %d",
2428                                 old_chunk,
2429                                 matching_chunk,
2430                                 tags.obj_id,
2431                                 tags.chunk_id);
2432         }
2433
2434         if (!object) {
2435                 yaffs_trace(YAFFS_TRACE_ERROR,
2436                         "page %d in gc has no object: %d %d %d ",
2437                         old_chunk,
2438                         tags.obj_id, tags.chunk_id,
2439                         tags.n_bytes);
2440         }
2441
2442         if (object &&
2443             object->deleted &&
2444             object->soft_del && tags.chunk_id != 0) {
2445                 /* Data chunk in a soft deleted file,
2446                  * throw it away.
2447                  * It's a soft deleted data chunk,
2448                  * No need to copy this, just forget
2449                  * about it and fix up the object.
2450                  */
2451
2452                 /* Free chunks already includes
2453                  * softdeleted chunks, how ever this
2454                  * chunk is going to soon be really
2455                  * deleted which will increment free
2456                  * chunks. We have to decrement free
2457                  * chunks so this works out properly.
2458                  */
2459                 dev->n_free_chunks--;
2460                 bi->soft_del_pages--;
2461
2462                 object->n_data_chunks--;
2463                 if (object->n_data_chunks <= 0) {
2464                         /* remeber to clean up obj */
2465                         dev->gc_cleanup_list[dev->n_clean_ups] = tags.obj_id;
2466                         dev->n_clean_ups++;
2467                 }
2468                 mark_flash = 0;
2469         } else if (object) {
2470                 /* It's either a data chunk in a live
2471                  * file or an ObjectHeader, so we're
2472                  * interested in it.
2473                  * NB Need to keep the ObjectHeaders of
2474                  * deleted files until the whole file
2475                  * has been deleted off
2476                  */
2477                 tags.serial_number++;
2478                 dev->n_gc_copies++;
2479
2480                 if (tags.chunk_id == 0) {
2481                         /* It is an object Id,
2482                          * We need to nuke the
2483                          * shrinkheader flags since its
2484                          * work is done.
2485                          * Also need to clean up
2486                          * shadowing.
2487                          */
2488                         struct yaffs_obj_hdr *oh;
2489                         oh = (struct yaffs_obj_hdr *) buffer;
2490
2491                         oh->is_shrink = 0;
2492                         tags.extra_is_shrink = 0;
2493                         oh->shadows_obj = 0;
2494                         oh->inband_shadowed_obj_id = 0;
2495                         tags.extra_shadows = 0;
2496
2497                         /* Update file size */
2498                         if (object->variant_type == YAFFS_OBJECT_TYPE_FILE) {
2499                                 oh->file_size =
2500                                     object->variant.file_variant.file_size;
2501                                 tags.extra_length = oh->file_size;
2502                         }
2503
2504                         yaffs_verify_oh(object, oh, &tags, 1);
2505                         new_chunk =
2506                             yaffs_write_new_chunk(dev, (u8 *) oh, &tags, 1);
2507                 } else {
2508                         new_chunk =
2509                             yaffs_write_new_chunk(dev, buffer, &tags, 1);
2510                 }
2511
2512                 if (new_chunk < 0) {
2513                         ret_val = YAFFS_FAIL;
2514                 } else {
2515
2516                         /* Now fix up the Tnodes etc. */
2517
2518                         if (tags.chunk_id == 0) {
2519                                 /* It's a header */
2520                                 object->hdr_chunk = new_chunk;
2521                                 object->serial = tags.serial_number;
2522                         } else {
2523                                 /* It's a data chunk */
2524                                 yaffs_put_chunk_in_file(object, tags.chunk_id,
2525                                                         new_chunk, 0);
2526                         }
2527                 }
2528         }
2529         if (ret_val == YAFFS_OK)
2530                 yaffs_chunk_del(dev, old_chunk, mark_flash, __LINE__);
2531         return ret_val;
2532 }
2533
2534 static int yaffs_gc_block(struct yaffs_dev *dev, int block, int whole_block)
2535 {
2536         int old_chunk;
2537         int ret_val = YAFFS_OK;
2538         int i;
2539         int is_checkpt_block;
2540         int max_copies;
2541         int chunks_before = yaffs_get_erased_chunks(dev);
2542         int chunks_after;
2543         struct yaffs_block_info *bi = yaffs_get_block_info(dev, block);
2544
2545         is_checkpt_block = (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT);
2546
2547         yaffs_trace(YAFFS_TRACE_TRACING,
2548                 "Collecting block %d, in use %d, shrink %d, whole_block %d",
2549                 block, bi->pages_in_use, bi->has_shrink_hdr,
2550                 whole_block);
2551
2552         /*yaffs_verify_free_chunks(dev); */
2553
2554         if (bi->block_state == YAFFS_BLOCK_STATE_FULL)
2555                 bi->block_state = YAFFS_BLOCK_STATE_COLLECTING;
2556
2557         bi->has_shrink_hdr = 0; /* clear the flag so that the block can erase */
2558
2559         dev->gc_disable = 1;
2560
2561         if (is_checkpt_block || !yaffs_still_some_chunks(dev, block)) {
2562                 yaffs_trace(YAFFS_TRACE_TRACING,
2563                         "Collecting block %d that has no chunks in use",
2564                         block);
2565                 yaffs_block_became_dirty(dev, block);
2566         } else {
2567
2568                 u8 *buffer = yaffs_get_temp_buffer(dev);
2569
2570                 yaffs_verify_blk(dev, bi, block);
2571
2572                 max_copies = (whole_block) ? dev->param.chunks_per_block : 5;
2573                 old_chunk = block * dev->param.chunks_per_block + dev->gc_chunk;
2574
2575                 for (/* init already done */ ;
2576                      ret_val == YAFFS_OK &&
2577                      dev->gc_chunk < dev->param.chunks_per_block &&
2578                      (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) &&
2579                      max_copies > 0;
2580                      dev->gc_chunk++, old_chunk++) {
2581                         if (yaffs_check_chunk_bit(dev, block, dev->gc_chunk)) {
2582                                 /* Page is in use and might need to be copied */
2583                                 max_copies--;
2584                                 ret_val = yaffs_gc_process_chunk(dev, bi,
2585                                                         old_chunk, buffer);
2586                         }
2587                 }
2588                 yaffs_release_temp_buffer(dev, buffer);
2589         }
2590
2591         yaffs_verify_collected_blk(dev, bi, block);
2592
2593         if (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
2594                 /*
2595                  * The gc did not complete. Set block state back to FULL
2596                  * because checkpointing does not restore gc.
2597                  */
2598                 bi->block_state = YAFFS_BLOCK_STATE_FULL;
2599         } else {
2600                 /* The gc completed. */
2601                 /* Do any required cleanups */
2602                 for (i = 0; i < dev->n_clean_ups; i++) {
2603                         /* Time to delete the file too */
2604                         struct yaffs_obj *object =
2605                             yaffs_find_by_number(dev, dev->gc_cleanup_list[i]);
2606                         if (object) {
2607                                 yaffs_free_tnode(dev,
2608                                           object->variant.file_variant.top);
2609                                 object->variant.file_variant.top = NULL;
2610                                 yaffs_trace(YAFFS_TRACE_GC,
2611                                         "yaffs: About to finally delete object %d",
2612                                         object->obj_id);
2613                                 yaffs_generic_obj_del(object);
2614                                 object->my_dev->n_deleted_files--;
2615                         }
2616
2617                 }
2618                 chunks_after = yaffs_get_erased_chunks(dev);
2619                 if (chunks_before >= chunks_after)
2620                         yaffs_trace(YAFFS_TRACE_GC,
2621                                 "gc did not increase free chunks before %d after %d",
2622                                 chunks_before, chunks_after);
2623                 dev->gc_block = 0;
2624                 dev->gc_chunk = 0;
2625                 dev->n_clean_ups = 0;
2626         }
2627
2628         dev->gc_disable = 0;
2629
2630         return ret_val;
2631 }
2632
2633 /*
2634  * find_gc_block() selects the dirtiest block (or close enough)
2635  * for garbage collection.
2636  */
2637
2638 static unsigned yaffs_find_gc_block(struct yaffs_dev *dev,
2639                                     int aggressive, int background)
2640 {
2641         int i;
2642         int iterations;
2643         unsigned selected = 0;
2644         int prioritised = 0;
2645         int prioritised_exist = 0;
2646         struct yaffs_block_info *bi;
2647         int threshold;
2648
2649         /* First let's see if we need to grab a prioritised block */
2650         if (dev->has_pending_prioritised_gc && !aggressive) {
2651                 dev->gc_dirtiest = 0;
2652                 bi = dev->block_info;
2653                 for (i = dev->internal_start_block;
2654                      i <= dev->internal_end_block && !selected; i++) {
2655
2656                         if (bi->gc_prioritise) {
2657                                 prioritised_exist = 1;
2658                                 if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
2659                                     yaffs_block_ok_for_gc(dev, bi)) {
2660                                         selected = i;
2661                                         prioritised = 1;
2662                                 }
2663                         }
2664                         bi++;
2665                 }
2666
2667                 /*
2668                  * If there is a prioritised block and none was selected then
2669                  * this happened because there is at least one old dirty block
2670                  * gumming up the works. Let's gc the oldest dirty block.
2671                  */
2672
2673                 if (prioritised_exist &&
2674                     !selected && dev->oldest_dirty_block > 0)
2675                         selected = dev->oldest_dirty_block;
2676
2677                 if (!prioritised_exist) /* None found, so we can clear this */
2678                         dev->has_pending_prioritised_gc = 0;
2679         }
2680
2681         /* If we're doing aggressive GC then we are happy to take a less-dirty
2682          * block, and search harder.
2683          * else (leasurely gc), then we only bother to do this if the
2684          * block has only a few pages in use.
2685          */
2686
2687         if (!selected) {
2688                 int pages_used;
2689                 int n_blocks =
2690                     dev->internal_end_block - dev->internal_start_block + 1;
2691                 if (aggressive) {
2692                         threshold = dev->param.chunks_per_block;
2693                         iterations = n_blocks;
2694                 } else {
2695                         int max_threshold;
2696
2697                         if (background)
2698                                 max_threshold = dev->param.chunks_per_block / 2;
2699                         else
2700                                 max_threshold = dev->param.chunks_per_block / 8;
2701
2702                         if (max_threshold < YAFFS_GC_PASSIVE_THRESHOLD)
2703                                 max_threshold = YAFFS_GC_PASSIVE_THRESHOLD;
2704
2705                         threshold = background ? (dev->gc_not_done + 2) * 2 : 0;
2706                         if (threshold < YAFFS_GC_PASSIVE_THRESHOLD)
2707                                 threshold = YAFFS_GC_PASSIVE_THRESHOLD;
2708                         if (threshold > max_threshold)
2709                                 threshold = max_threshold;
2710
2711                         iterations = n_blocks / 16 + 1;
2712                         if (iterations > 100)
2713                                 iterations = 100;
2714                 }
2715
2716                 for (i = 0;
2717                      i < iterations &&
2718                      (dev->gc_dirtiest < 1 ||
2719                       dev->gc_pages_in_use > YAFFS_GC_GOOD_ENOUGH);
2720                      i++) {
2721                         dev->gc_block_finder++;
2722                         if (dev->gc_block_finder < dev->internal_start_block ||
2723                             dev->gc_block_finder > dev->internal_end_block)
2724                                 dev->gc_block_finder =
2725                                     dev->internal_start_block;
2726
2727                         bi = yaffs_get_block_info(dev, dev->gc_block_finder);
2728
2729                         pages_used = bi->pages_in_use - bi->soft_del_pages;
2730
2731                         if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
2732                             pages_used < dev->param.chunks_per_block &&
2733                             (dev->gc_dirtiest < 1 ||
2734                              pages_used < dev->gc_pages_in_use) &&
2735                             yaffs_block_ok_for_gc(dev, bi)) {
2736                                 dev->gc_dirtiest = dev->gc_block_finder;
2737                                 dev->gc_pages_in_use = pages_used;
2738                         }
2739                 }
2740
2741                 if (dev->gc_dirtiest > 0 && dev->gc_pages_in_use <= threshold)
2742                         selected = dev->gc_dirtiest;
2743         }
2744
2745         /*
2746          * If nothing has been selected for a while, try the oldest dirty
2747          * because that's gumming up the works.
2748          */
2749
2750         if (!selected && dev->param.is_yaffs2 &&
2751             dev->gc_not_done >= (background ? 10 : 20)) {
2752                 yaffs2_find_oldest_dirty_seq(dev);
2753                 if (dev->oldest_dirty_block > 0) {
2754                         selected = dev->oldest_dirty_block;
2755                         dev->gc_dirtiest = selected;
2756                         dev->oldest_dirty_gc_count++;
2757                         bi = yaffs_get_block_info(dev, selected);
2758                         dev->gc_pages_in_use =
2759                             bi->pages_in_use - bi->soft_del_pages;
2760                 } else {
2761                         dev->gc_not_done = 0;
2762                 }
2763         }
2764
2765         if (selected) {
2766                 yaffs_trace(YAFFS_TRACE_GC,
2767                         "GC Selected block %d with %d free, prioritised:%d",
2768                         selected,
2769                         dev->param.chunks_per_block - dev->gc_pages_in_use,
2770                         prioritised);
2771
2772                 dev->n_gc_blocks++;
2773                 if (background)
2774                         dev->bg_gcs++;
2775
2776                 dev->gc_dirtiest = 0;
2777                 dev->gc_pages_in_use = 0;
2778                 dev->gc_not_done = 0;
2779                 if (dev->refresh_skip > 0)
2780                         dev->refresh_skip--;
2781         } else {
2782                 dev->gc_not_done++;
2783                 yaffs_trace(YAFFS_TRACE_GC,
2784                         "GC none: finder %d skip %d threshold %d dirtiest %d using %d oldest %d%s",
2785                         dev->gc_block_finder, dev->gc_not_done, threshold,
2786                         dev->gc_dirtiest, dev->gc_pages_in_use,
2787                         dev->oldest_dirty_block, background ? " bg" : "");
2788         }
2789
2790         return selected;
2791 }
2792
2793 /* New garbage collector
2794  * If we're very low on erased blocks then we do aggressive garbage collection
2795  * otherwise we do "leasurely" garbage collection.
2796  * Aggressive gc looks further (whole array) and will accept less dirty blocks.
2797  * Passive gc only inspects smaller areas and only accepts more dirty blocks.
2798  *
2799  * The idea is to help clear out space in a more spread-out manner.
2800  * Dunno if it really does anything useful.
2801  */
2802 static int yaffs_check_gc(struct yaffs_dev *dev, int background)
2803 {
2804         int aggressive = 0;
2805         int gc_ok = YAFFS_OK;
2806         int max_tries = 0;
2807         int min_erased;
2808         int erased_chunks;
2809         int checkpt_block_adjust;
2810
2811         if (dev->param.gc_control && (dev->param.gc_control(dev) & 1) == 0)
2812                 return YAFFS_OK;
2813
2814         if (dev->gc_disable)
2815                 /* Bail out so we don't get recursive gc */
2816                 return YAFFS_OK;
2817
2818         /* This loop should pass the first time.
2819          * Only loops here if the collection does not increase space.
2820          */
2821
2822         do {
2823                 max_tries++;
2824
2825                 checkpt_block_adjust = yaffs_calc_checkpt_blocks_required(dev);
2826
2827                 min_erased =
2828                     dev->param.n_reserved_blocks + checkpt_block_adjust + 1;
2829                 erased_chunks =
2830                     dev->n_erased_blocks * dev->param.chunks_per_block;
2831
2832                 /* If we need a block soon then do aggressive gc. */
2833                 if (dev->n_erased_blocks < min_erased)
2834                         aggressive = 1;
2835                 else {
2836                         if (!background
2837                             && erased_chunks > (dev->n_free_chunks / 4))
2838                                 break;
2839
2840                         if (dev->gc_skip > 20)
2841                                 dev->gc_skip = 20;
2842                         if (erased_chunks < dev->n_free_chunks / 2 ||
2843                             dev->gc_skip < 1 || background)
2844                                 aggressive = 0;
2845                         else {
2846                                 dev->gc_skip--;
2847                                 break;
2848                         }
2849                 }
2850
2851                 dev->gc_skip = 5;
2852
2853                 /* If we don't already have a block being gc'd then see if we
2854                  * should start another */
2855
2856                 if (dev->gc_block < 1 && !aggressive) {
2857                         dev->gc_block = yaffs2_find_refresh_block(dev);
2858                         dev->gc_chunk = 0;
2859                         dev->n_clean_ups = 0;
2860                 }
2861                 if (dev->gc_block < 1) {
2862                         dev->gc_block =
2863                             yaffs_find_gc_block(dev, aggressive, background);
2864                         dev->gc_chunk = 0;
2865                         dev->n_clean_ups = 0;
2866                 }
2867
2868                 if (dev->gc_block > 0) {
2869                         dev->all_gcs++;
2870                         if (!aggressive)
2871                                 dev->passive_gc_count++;
2872
2873                         yaffs_trace(YAFFS_TRACE_GC,
2874                                 "yaffs: GC n_erased_blocks %d aggressive %d",
2875                                 dev->n_erased_blocks, aggressive);
2876
2877                         gc_ok = yaffs_gc_block(dev, dev->gc_block, aggressive);
2878                 }
2879
2880                 if (dev->n_erased_blocks < (dev->param.n_reserved_blocks) &&
2881                     dev->gc_block > 0) {
2882                         yaffs_trace(YAFFS_TRACE_GC,
2883                                 "yaffs: GC !!!no reclaim!!! n_erased_blocks %d after try %d block %d",
2884                                 dev->n_erased_blocks, max_tries,
2885                                 dev->gc_block);
2886                 }
2887         } while ((dev->n_erased_blocks < dev->param.n_reserved_blocks) &&
2888                  (dev->gc_block > 0) && (max_tries < 2));
2889
2890         return aggressive ? gc_ok : YAFFS_OK;
2891 }
2892
2893 /*
2894  * yaffs_bg_gc()
2895  * Garbage collects. Intended to be called from a background thread.
2896  * Returns non-zero if at least half the free chunks are erased.
2897  */
2898 int yaffs_bg_gc(struct yaffs_dev *dev, unsigned urgency)
2899 {
2900         int erased_chunks = dev->n_erased_blocks * dev->param.chunks_per_block;
2901
2902         yaffs_trace(YAFFS_TRACE_BACKGROUND, "Background gc %u", urgency);
2903
2904         yaffs_check_gc(dev, 1);
2905         return erased_chunks > dev->n_free_chunks / 2;
2906 }
2907
2908 /*-------------------- Data file manipulation -----------------*/
2909
2910 static int yaffs_rd_data_obj(struct yaffs_obj *in, int inode_chunk, u8 * buffer)
2911 {
2912         int nand_chunk = yaffs_find_chunk_in_file(in, inode_chunk, NULL);
2913
2914         if (nand_chunk >= 0)
2915                 return yaffs_rd_chunk_tags_nand(in->my_dev, nand_chunk,
2916                                                 buffer, NULL);
2917         else {
2918                 yaffs_trace(YAFFS_TRACE_NANDACCESS,
2919                         "Chunk %d not found zero instead",
2920                         nand_chunk);
2921                 /* get sane (zero) data if you read a hole */
2922                 memset(buffer, 0, in->my_dev->data_bytes_per_chunk);
2923                 return 0;
2924         }
2925
2926 }
2927
2928 void yaffs_chunk_del(struct yaffs_dev *dev, int chunk_id, int mark_flash,
2929                      int lyn)
2930 {
2931         int block;
2932         int page;
2933         struct yaffs_ext_tags tags;
2934         struct yaffs_block_info *bi;
2935
2936         if (chunk_id <= 0)
2937                 return;
2938
2939         dev->n_deletions++;
2940         block = chunk_id / dev->param.chunks_per_block;
2941         page = chunk_id % dev->param.chunks_per_block;
2942
2943         if (!yaffs_check_chunk_bit(dev, block, page))
2944                 yaffs_trace(YAFFS_TRACE_VERIFY,
2945                         "Deleting invalid chunk %d", chunk_id);
2946
2947         bi = yaffs_get_block_info(dev, block);
2948
2949         yaffs2_update_oldest_dirty_seq(dev, block, bi);
2950
2951         yaffs_trace(YAFFS_TRACE_DELETION,
2952                 "line %d delete of chunk %d",
2953                 lyn, chunk_id);
2954
2955         if (!dev->param.is_yaffs2 && mark_flash &&
2956             bi->block_state != YAFFS_BLOCK_STATE_COLLECTING) {
2957
2958                 memset(&tags, 0, sizeof(tags));
2959                 tags.is_deleted = 1;
2960                 yaffs_wr_chunk_tags_nand(dev, chunk_id, NULL, &tags);
2961                 yaffs_handle_chunk_update(dev, chunk_id, &tags);
2962         } else {
2963                 dev->n_unmarked_deletions++;
2964         }
2965
2966         /* Pull out of the management area.
2967          * If the whole block became dirty, this will kick off an erasure.
2968          */
2969         if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING ||
2970             bi->block_state == YAFFS_BLOCK_STATE_FULL ||
2971             bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCAN ||
2972             bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
2973                 dev->n_free_chunks++;
2974                 yaffs_clear_chunk_bit(dev, block, page);
2975                 bi->pages_in_use--;
2976
2977                 if (bi->pages_in_use == 0 &&
2978                     !bi->has_shrink_hdr &&
2979                     bi->block_state != YAFFS_BLOCK_STATE_ALLOCATING &&
2980                     bi->block_state != YAFFS_BLOCK_STATE_NEEDS_SCAN) {
2981                         yaffs_block_became_dirty(dev, block);
2982                 }
2983         }
2984 }
2985
2986 static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
2987                              const u8 *buffer, int n_bytes, int use_reserve)
2988 {
2989         /* Find old chunk Need to do this to get serial number
2990          * Write new one and patch into tree.
2991          * Invalidate old tags.
2992          */
2993
2994         int prev_chunk_id;
2995         struct yaffs_ext_tags prev_tags;
2996         int new_chunk_id;
2997         struct yaffs_ext_tags new_tags;
2998         struct yaffs_dev *dev = in->my_dev;
2999
3000         yaffs_check_gc(dev, 0);
3001
3002         /* Get the previous chunk at this location in the file if it exists.
3003          * If it does not exist then put a zero into the tree. This creates
3004          * the tnode now, rather than later when it is harder to clean up.
3005          */
3006         prev_chunk_id = yaffs_find_chunk_in_file(in, inode_chunk, &prev_tags);
3007         if (prev_chunk_id < 1 &&
3008             !yaffs_put_chunk_in_file(in, inode_chunk, 0, 0))
3009                 return 0;
3010
3011         /* Set up new tags */
3012         memset(&new_tags, 0, sizeof(new_tags));
3013
3014         new_tags.chunk_id = inode_chunk;
3015         new_tags.obj_id = in->obj_id;
3016         new_tags.serial_number =
3017             (prev_chunk_id > 0) ? prev_tags.serial_number + 1 : 1;
3018         new_tags.n_bytes = n_bytes;
3019
3020         if (n_bytes < 1 || n_bytes > dev->param.total_bytes_per_chunk) {
3021                 yaffs_trace(YAFFS_TRACE_ERROR,
3022                   "Writing %d bytes to chunk!!!!!!!!!",
3023                    n_bytes);
3024                 BUG();
3025         }
3026
3027         new_chunk_id =
3028             yaffs_write_new_chunk(dev, buffer, &new_tags, use_reserve);
3029
3030         if (new_chunk_id > 0) {
3031                 yaffs_put_chunk_in_file(in, inode_chunk, new_chunk_id, 0);
3032
3033                 if (prev_chunk_id > 0)
3034                         yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
3035
3036                 yaffs_verify_file_sane(in);
3037         }
3038         return new_chunk_id;
3039
3040 }
3041
3042
3043
3044 static int yaffs_do_xattrib_mod(struct yaffs_obj *obj, int set,
3045                                 const YCHAR *name, const void *value, int size,
3046                                 int flags)
3047 {
3048         struct yaffs_xattr_mod xmod;
3049         int result;
3050
3051         xmod.set = set;
3052         xmod.name = name;
3053         xmod.data = value;
3054         xmod.size = size;
3055         xmod.flags = flags;
3056         xmod.result = -ENOSPC;
3057
3058         result = yaffs_update_oh(obj, NULL, 0, 0, 0, &xmod);
3059
3060         if (result > 0)
3061                 return xmod.result;
3062         else
3063                 return -ENOSPC;
3064 }
3065
3066 static int yaffs_apply_xattrib_mod(struct yaffs_obj *obj, char *buffer,
3067                                    struct yaffs_xattr_mod *xmod)
3068 {
3069         int retval = 0;
3070         int x_offs = sizeof(struct yaffs_obj_hdr);
3071         struct yaffs_dev *dev = obj->my_dev;
3072         int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
3073         char *x_buffer = buffer + x_offs;
3074
3075         if (xmod->set)
3076                 retval =
3077                     nval_set(x_buffer, x_size, xmod->name, xmod->data,
3078                              xmod->size, xmod->flags);
3079         else
3080                 retval = nval_del(x_buffer, x_size, xmod->name);
3081
3082         obj->has_xattr = nval_hasvalues(x_buffer, x_size);
3083         obj->xattr_known = 1;
3084         xmod->result = retval;
3085
3086         return retval;
3087 }
3088
3089 static int yaffs_do_xattrib_fetch(struct yaffs_obj *obj, const YCHAR *name,
3090                                   void *value, int size)
3091 {
3092         char *buffer = NULL;
3093         int result;
3094         struct yaffs_ext_tags tags;
3095         struct yaffs_dev *dev = obj->my_dev;
3096         int x_offs = sizeof(struct yaffs_obj_hdr);
3097         int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
3098         char *x_buffer;
3099         int retval = 0;
3100
3101         if (obj->hdr_chunk < 1)
3102                 return -ENODATA;
3103
3104         /* If we know that the object has no xattribs then don't do all the
3105          * reading and parsing.
3106          */
3107         if (obj->xattr_known && !obj->has_xattr) {
3108                 if (name)
3109                         return -ENODATA;
3110                 else
3111                         return 0;
3112         }
3113
3114         buffer = (char *)yaffs_get_temp_buffer(dev);
3115         if (!buffer)
3116                 return -ENOMEM;
3117
3118         result =
3119             yaffs_rd_chunk_tags_nand(dev, obj->hdr_chunk, (u8 *) buffer, &tags);
3120
3121         if (result != YAFFS_OK)
3122                 retval = -ENOENT;
3123         else {
3124                 x_buffer = buffer + x_offs;
3125
3126                 if (!obj->xattr_known) {
3127                         obj->has_xattr = nval_hasvalues(x_buffer, x_size);
3128                         obj->xattr_known = 1;
3129                 }
3130
3131                 if (name)
3132                         retval = nval_get(x_buffer, x_size, name, value, size);
3133                 else
3134                         retval = nval_list(x_buffer, x_size, value, size);
3135         }
3136         yaffs_release_temp_buffer(dev, (u8 *) buffer);
3137         return retval;
3138 }
3139
3140 int yaffs_set_xattrib(struct yaffs_obj *obj, const YCHAR * name,
3141                       const void *value, int size, int flags)
3142 {
3143         return yaffs_do_xattrib_mod(obj, 1, name, value, size, flags);
3144 }
3145
3146 int yaffs_remove_xattrib(struct yaffs_obj *obj, const YCHAR * name)
3147 {
3148         return yaffs_do_xattrib_mod(obj, 0, name, NULL, 0, 0);
3149 }
3150
3151 int yaffs_get_xattrib(struct yaffs_obj *obj, const YCHAR * name, void *value,
3152                       int size)
3153 {
3154         return yaffs_do_xattrib_fetch(obj, name, value, size);
3155 }
3156
3157 int yaffs_list_xattrib(struct yaffs_obj *obj, char *buffer, int size)
3158 {
3159         return yaffs_do_xattrib_fetch(obj, NULL, buffer, size);
3160 }
3161
3162 static void yaffs_check_obj_details_loaded(struct yaffs_obj *in)
3163 {
3164         u8 *buf;
3165         struct yaffs_obj_hdr *oh;
3166         struct yaffs_dev *dev;
3167         struct yaffs_ext_tags tags;
3168         int result;
3169         int alloc_failed = 0;
3170
3171         if (!in || !in->lazy_loaded || in->hdr_chunk < 1)
3172                 return;
3173
3174         dev = in->my_dev;
3175         in->lazy_loaded = 0;
3176         buf = yaffs_get_temp_buffer(dev);
3177
3178         result = yaffs_rd_chunk_tags_nand(dev, in->hdr_chunk, buf, &tags);
3179         oh = (struct yaffs_obj_hdr *)buf;
3180
3181         in->yst_mode = oh->yst_mode;
3182         yaffs_load_attribs(in, oh);
3183         yaffs_set_obj_name_from_oh(in, oh);
3184
3185         if (in->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
3186                 in->variant.symlink_variant.alias =
3187                     yaffs_clone_str(oh->alias);
3188                 if (!in->variant.symlink_variant.alias)
3189                         alloc_failed = 1;       /* Not returned */
3190         }
3191         yaffs_release_temp_buffer(dev, buf);
3192 }
3193
3194 static void yaffs_load_name_from_oh(struct yaffs_dev *dev, YCHAR *name,
3195                                     const YCHAR *oh_name, int buff_size)
3196 {
3197 #ifdef CONFIG_YAFFS_AUTO_UNICODE
3198         if (dev->param.auto_unicode) {
3199                 if (*oh_name) {
3200                         /* It is an ASCII name, do an ASCII to
3201                          * unicode conversion */
3202                         const char *ascii_oh_name = (const char *)oh_name;
3203                         int n = buff_size - 1;
3204                         while (n > 0 && *ascii_oh_name) {
3205                                 *name = *ascii_oh_name;
3206                                 name++;
3207                                 ascii_oh_name++;
3208                                 n--;
3209                         }
3210                 } else {
3211                         strncpy(name, oh_name + 1, buff_size - 1);
3212                 }
3213         } else {
3214 #else
3215         {
3216 #endif
3217                 strncpy(name, oh_name, buff_size - 1);
3218         }
3219 }
3220
3221 static void yaffs_load_oh_from_name(struct yaffs_dev *dev, YCHAR *oh_name,
3222                                     const YCHAR *name)
3223 {
3224 #ifdef CONFIG_YAFFS_AUTO_UNICODE
3225
3226         int is_ascii;
3227         YCHAR *w;
3228
3229         if (dev->param.auto_unicode) {
3230
3231                 is_ascii = 1;
3232                 w = name;
3233
3234                 /* Figure out if the name will fit in ascii character set */
3235                 while (is_ascii && *w) {
3236                         if ((*w) & 0xff00)
3237                                 is_ascii = 0;
3238                         w++;
3239                 }
3240
3241                 if (is_ascii) {
3242                         /* It is an ASCII name, so convert unicode to ascii */
3243                         char *ascii_oh_name = (char *)oh_name;
3244                         int n = YAFFS_MAX_NAME_LENGTH - 1;
3245                         while (n > 0 && *name) {
3246                                 *ascii_oh_name = *name;
3247                                 name++;
3248                                 ascii_oh_name++;
3249                                 n--;
3250                         }
3251                 } else {
3252                         /* Unicode name, so save starting at the second YCHAR */
3253                         *oh_name = 0;
3254                         strncpy(oh_name + 1, name, YAFFS_MAX_NAME_LENGTH - 2);
3255                 }
3256         } else {
3257 #else
3258         {
3259 #endif
3260                 strncpy(oh_name, name, YAFFS_MAX_NAME_LENGTH - 1);
3261         }
3262 }
3263
3264 /* UpdateObjectHeader updates the header on NAND for an object.
3265  * If name is not NULL, then that new name is used.
3266  */
3267 int yaffs_update_oh(struct yaffs_obj *in, const YCHAR *name, int force,
3268                     int is_shrink, int shadows, struct yaffs_xattr_mod *xmod)
3269 {
3270
3271         struct yaffs_block_info *bi;
3272         struct yaffs_dev *dev = in->my_dev;
3273         int prev_chunk_id;
3274         int ret_val = 0;
3275         int result = 0;
3276         int new_chunk_id;
3277         struct yaffs_ext_tags new_tags;
3278         struct yaffs_ext_tags old_tags;
3279         const YCHAR *alias = NULL;
3280         u8 *buffer = NULL;
3281         YCHAR old_name[YAFFS_MAX_NAME_LENGTH + 1];
3282         struct yaffs_obj_hdr *oh = NULL;
3283
3284         strcpy(old_name, _Y("silly old name"));
3285
3286         if (in->fake && in != dev->root_dir && !force && !xmod)
3287                 return ret_val;
3288
3289         yaffs_check_gc(dev, 0);
3290         yaffs_check_obj_details_loaded(in);
3291
3292         buffer = yaffs_get_temp_buffer(in->my_dev);
3293         oh = (struct yaffs_obj_hdr *)buffer;
3294
3295         prev_chunk_id = in->hdr_chunk;
3296
3297         if (prev_chunk_id > 0) {
3298                 result = yaffs_rd_chunk_tags_nand(dev, prev_chunk_id,
3299                                                   buffer, &old_tags);
3300
3301                 yaffs_verify_oh(in, oh, &old_tags, 0);
3302                 memcpy(old_name, oh->name, sizeof(oh->name));
3303                 memset(buffer, 0xff, sizeof(struct yaffs_obj_hdr));
3304         } else {
3305                 memset(buffer, 0xff, dev->data_bytes_per_chunk);
3306         }
3307
3308         oh->type = in->variant_type;
3309         oh->yst_mode = in->yst_mode;
3310         oh->shadows_obj = oh->inband_shadowed_obj_id = shadows;
3311
3312         yaffs_load_attribs_oh(oh, in);
3313
3314         if (in->parent)
3315                 oh->parent_obj_id = in->parent->obj_id;
3316         else
3317                 oh->parent_obj_id = 0;
3318
3319         if (name && *name) {
3320                 memset(oh->name, 0, sizeof(oh->name));
3321                 yaffs_load_oh_from_name(dev, oh->name, name);
3322         } else if (prev_chunk_id > 0) {
3323                 memcpy(oh->name, old_name, sizeof(oh->name));
3324         } else {
3325                 memset(oh->name, 0, sizeof(oh->name));
3326         }
3327
3328         oh->is_shrink = is_shrink;
3329
3330         switch (in->variant_type) {
3331         case YAFFS_OBJECT_TYPE_UNKNOWN:
3332                 /* Should not happen */
3333                 break;
3334         case YAFFS_OBJECT_TYPE_FILE:
3335                 oh->file_size =
3336                     (oh->parent_obj_id == YAFFS_OBJECTID_DELETED ||
3337                      oh->parent_obj_id == YAFFS_OBJECTID_UNLINKED) ?
3338                      0 : in->variant.file_variant.file_size;
3339                 break;
3340         case YAFFS_OBJECT_TYPE_HARDLINK:
3341                 oh->equiv_id = in->variant.hardlink_variant.equiv_id;
3342                 break;
3343         case YAFFS_OBJECT_TYPE_SPECIAL:
3344                 /* Do nothing */
3345                 break;
3346         case YAFFS_OBJECT_TYPE_DIRECTORY:
3347                 /* Do nothing */
3348                 break;
3349         case YAFFS_OBJECT_TYPE_SYMLINK:
3350                 alias = in->variant.symlink_variant.alias;
3351                 if (!alias)
3352                         alias = _Y("no alias");
3353                 strncpy(oh->alias, alias, YAFFS_MAX_ALIAS_LENGTH);
3354                 oh->alias[YAFFS_MAX_ALIAS_LENGTH] = 0;
3355                 break;
3356         }
3357
3358         /* process any xattrib modifications */
3359         if (xmod)
3360                 yaffs_apply_xattrib_mod(in, (char *)buffer, xmod);
3361
3362         /* Tags */
3363         memset(&new_tags, 0, sizeof(new_tags));
3364         in->serial++;
3365         new_tags.chunk_id = 0;
3366         new_tags.obj_id = in->obj_id;
3367         new_tags.serial_number = in->serial;
3368
3369         /* Add extra info for file header */
3370         new_tags.extra_available = 1;
3371         new_tags.extra_parent_id = oh->parent_obj_id;
3372         new_tags.extra_length = oh->file_size;
3373         new_tags.extra_is_shrink = oh->is_shrink;
3374         new_tags.extra_equiv_id = oh->equiv_id;
3375         new_tags.extra_shadows = (oh->shadows_obj > 0) ? 1 : 0;
3376         new_tags.extra_obj_type = in->variant_type;
3377         yaffs_verify_oh(in, oh, &new_tags, 1);
3378
3379         /* Create new chunk in NAND */
3380         new_chunk_id =
3381             yaffs_write_new_chunk(dev, buffer, &new_tags,
3382                                   (prev_chunk_id > 0) ? 1 : 0);
3383
3384         if (buffer)
3385                 yaffs_release_temp_buffer(dev, buffer);
3386
3387         if (new_chunk_id < 0)
3388                 return new_chunk_id;
3389
3390         in->hdr_chunk = new_chunk_id;
3391
3392         if (prev_chunk_id > 0)
3393                 yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
3394
3395         if (!yaffs_obj_cache_dirty(in))
3396                 in->dirty = 0;
3397
3398         /* If this was a shrink, then mark the block
3399          * that the chunk lives on */
3400         if (is_shrink) {
3401                 bi = yaffs_get_block_info(in->my_dev,
3402                                           new_chunk_id /
3403                                           in->my_dev->param.chunks_per_block);
3404                 bi->has_shrink_hdr = 1;
3405         }
3406
3407
3408         return new_chunk_id;
3409 }
3410
3411 /*--------------------- File read/write ------------------------
3412  * Read and write have very similar structures.
3413  * In general the read/write has three parts to it
3414  * An incomplete chunk to start with (if the read/write is not chunk-aligned)
3415  * Some complete chunks
3416  * An incomplete chunk to end off with
3417  *
3418  * Curve-balls: the first chunk might also be the last chunk.
3419  */
3420
3421 int yaffs_file_rd(struct yaffs_obj *in, u8 * buffer, loff_t offset, int n_bytes)
3422 {
3423         int chunk;
3424         u32 start;
3425         int n_copy;
3426         int n = n_bytes;
3427         int n_done = 0;
3428         struct yaffs_cache *cache;
3429         struct yaffs_dev *dev;
3430
3431         dev = in->my_dev;
3432
3433         while (n > 0) {
3434                 yaffs_addr_to_chunk(dev, offset, &chunk, &start);
3435                 chunk++;
3436
3437                 /* OK now check for the curveball where the start and end are in
3438                  * the same chunk.
3439                  */
3440                 if ((start + n) < dev->data_bytes_per_chunk)
3441                         n_copy = n;
3442                 else
3443                         n_copy = dev->data_bytes_per_chunk - start;
3444
3445                 cache = yaffs_find_chunk_cache(in, chunk);
3446
3447                 /* If the chunk is already in the cache or it is less than
3448                  * a whole chunk or we're using inband tags then use the cache
3449                  * (if there is caching) else bypass the cache.
3450                  */
3451                 if (cache || n_copy != dev->data_bytes_per_chunk ||
3452                     dev->param.inband_tags) {
3453                         if (dev->param.n_caches > 0) {
3454
3455                                 /* If we can't find the data in the cache,
3456                                  * then load it up. */
3457
3458                                 if (!cache) {
3459                                         cache =
3460                                             yaffs_grab_chunk_cache(in->my_dev);
3461                                         cache->object = in;
3462                                         cache->chunk_id = chunk;
3463                                         cache->dirty = 0;
3464                                         cache->locked = 0;
3465                                         yaffs_rd_data_obj(in, chunk,
3466                                                           cache->data);
3467                                         cache->n_bytes = 0;
3468                                 }
3469
3470                                 yaffs_use_cache(dev, cache, 0);
3471
3472                                 cache->locked = 1;
3473
3474                                 memcpy(buffer, &cache->data[start], n_copy);
3475
3476                                 cache->locked = 0;
3477                         } else {
3478                                 /* Read into the local buffer then copy.. */
3479
3480                                 u8 *local_buffer =
3481                                     yaffs_get_temp_buffer(dev);
3482                                 yaffs_rd_data_obj(in, chunk, local_buffer);
3483
3484                                 memcpy(buffer, &local_buffer[start], n_copy);
3485
3486                                 yaffs_release_temp_buffer(dev, local_buffer);
3487                         }
3488                 } else {
3489                         /* A full chunk. Read directly into the buffer. */
3490                         yaffs_rd_data_obj(in, chunk, buffer);
3491                 }
3492                 n -= n_copy;
3493                 offset += n_copy;
3494                 buffer += n_copy;
3495                 n_done += n_copy;
3496         }
3497         return n_done;
3498 }
3499
3500 int yaffs_do_file_wr(struct yaffs_obj *in, const u8 *buffer, loff_t offset,
3501                      int n_bytes, int write_trhrough)
3502 {
3503
3504         int chunk;
3505         u32 start;
3506         int n_copy;
3507         int n = n_bytes;
3508         int n_done = 0;
3509         int n_writeback;
3510         int start_write = offset;
3511         int chunk_written = 0;
3512         u32 n_bytes_read;
3513         u32 chunk_start;
3514         struct yaffs_dev *dev;
3515
3516         dev = in->my_dev;
3517
3518         while (n > 0 && chunk_written >= 0) {
3519                 yaffs_addr_to_chunk(dev, offset, &chunk, &start);
3520
3521                 if (chunk * dev->data_bytes_per_chunk + start != offset ||
3522                     start >= dev->data_bytes_per_chunk) {
3523                         yaffs_trace(YAFFS_TRACE_ERROR,
3524                                 "AddrToChunk of offset %d gives chunk %d start %d",
3525                                 (int)offset, chunk, start);
3526                 }
3527                 chunk++;        /* File pos to chunk in file offset */
3528
3529                 /* OK now check for the curveball where the start and end are in
3530                  * the same chunk.
3531                  */
3532
3533                 if ((start + n) < dev->data_bytes_per_chunk) {
3534                         n_copy = n;
3535
3536                         /* Now calculate how many bytes to write back....
3537                          * If we're overwriting and not writing to then end of
3538                          * file then we need to write back as much as was there
3539                          * before.
3540                          */
3541
3542                         chunk_start = ((chunk - 1) * dev->data_bytes_per_chunk);
3543
3544                         if (chunk_start > in->variant.file_variant.file_size)
3545                                 n_bytes_read = 0;       /* Past end of file */
3546                         else
3547                                 n_bytes_read =
3548                                     in->variant.file_variant.file_size -
3549                                     chunk_start;
3550
3551                         if (n_bytes_read > dev->data_bytes_per_chunk)
3552                                 n_bytes_read = dev->data_bytes_per_chunk;
3553
3554                         n_writeback =
3555                             (n_bytes_read >
3556                              (start + n)) ? n_bytes_read : (start + n);
3557
3558                         if (n_writeback < 0 ||
3559                             n_writeback > dev->data_bytes_per_chunk)
3560                                 BUG();
3561
3562                 } else {
3563                         n_copy = dev->data_bytes_per_chunk - start;
3564                         n_writeback = dev->data_bytes_per_chunk;
3565                 }
3566
3567                 if (n_copy != dev->data_bytes_per_chunk ||
3568                     dev->param.inband_tags) {
3569                         /* An incomplete start or end chunk (or maybe both
3570                          * start and end chunk), or we're using inband tags,
3571                          * so we want to use the cache buffers.
3572                          */
3573                         if (dev->param.n_caches > 0) {
3574                                 struct yaffs_cache *cache;
3575
3576                                 /* If we can't find the data in the cache, then
3577                                  * load the cache */
3578                                 cache = yaffs_find_chunk_cache(in, chunk);
3579
3580                                 if (!cache &&
3581                                     yaffs_check_alloc_available(dev, 1)) {
3582                                         cache = yaffs_grab_chunk_cache(dev);
3583                                         cache->object = in;
3584                                         cache->chunk_id = chunk;
3585                                         cache->dirty = 0;
3586                                         cache->locked = 0;
3587                                         yaffs_rd_data_obj(in, chunk,
3588                                                           cache->data);
3589                                 } else if (cache &&
3590                                            !cache->dirty &&
3591                                            !yaffs_check_alloc_available(dev,
3592                                                                         1)) {
3593                                         /* Drop the cache if it was a read cache
3594                                          * item and no space check has been made
3595                                          * for it.
3596                                          */
3597                                         cache = NULL;
3598                                 }
3599
3600                                 if (cache) {
3601                                         yaffs_use_cache(dev, cache, 1);
3602                                         cache->locked = 1;
3603
3604                                         memcpy(&cache->data[start], buffer,
3605                                                n_copy);
3606
3607                                         cache->locked = 0;
3608                                         cache->n_bytes = n_writeback;
3609
3610                                         if (write_trhrough) {
3611                                                 chunk_written =
3612                                                     yaffs_wr_data_obj
3613                                                     (cache->object,
3614                                                      cache->chunk_id,
3615                                                      cache->data,
3616                                                      cache->n_bytes, 1);
3617                                                 cache->dirty = 0;
3618                                         }
3619                                 } else {
3620                                         chunk_written = -1;     /* fail write */
3621                                 }
3622                         } else {
3623                                 /* An incomplete start or end chunk (or maybe
3624                                  * both start and end chunk). Read into the
3625                                  * local buffer then copy over and write back.
3626                                  */
3627
3628                                 u8 *local_buffer = yaffs_get_temp_buffer(dev);
3629
3630                                 yaffs_rd_data_obj(in, chunk, local_buffer);
3631                                 memcpy(&local_buffer[start], buffer, n_copy);
3632
3633                                 chunk_written =
3634                                     yaffs_wr_data_obj(in, chunk,
3635                                                       local_buffer,
3636                                                       n_writeback, 0);
3637
3638                                 yaffs_release_temp_buffer(dev, local_buffer);
3639                         }
3640                 } else {
3641                         /* A full chunk. Write directly from the buffer. */
3642
3643                         chunk_written =
3644                             yaffs_wr_data_obj(in, chunk, buffer,
3645                                               dev->data_bytes_per_chunk, 0);
3646
3647                         /* Since we've overwritten the cached data,
3648                          * we better invalidate it. */
3649                         yaffs_invalidate_chunk_cache(in, chunk);
3650                 }
3651
3652                 if (chunk_written >= 0) {
3653                         n -= n_copy;
3654                         offset += n_copy;
3655                         buffer += n_copy;
3656                         n_done += n_copy;
3657                 }
3658         }
3659
3660         /* Update file object */
3661
3662         if ((start_write + n_done) > in->variant.file_variant.file_size)
3663                 in->variant.file_variant.file_size = (start_write + n_done);
3664
3665         in->dirty = 1;
3666         return n_done;
3667 }
3668
3669 int yaffs_wr_file(struct yaffs_obj *in, const u8 *buffer, loff_t offset,
3670                   int n_bytes, int write_trhrough)
3671 {
3672         yaffs2_handle_hole(in, offset);
3673         return yaffs_do_file_wr(in, buffer, offset, n_bytes, write_trhrough);
3674 }
3675
3676 /* ---------------------- File resizing stuff ------------------ */
3677
3678 static void yaffs_prune_chunks(struct yaffs_obj *in, int new_size)
3679 {
3680
3681         struct yaffs_dev *dev = in->my_dev;
3682         int old_size = in->variant.file_variant.file_size;
3683         int i;
3684         int chunk_id;
3685         int last_del = 1 + (old_size - 1) / dev->data_bytes_per_chunk;
3686         int start_del = 1 + (new_size + dev->data_bytes_per_chunk - 1) /
3687             dev->data_bytes_per_chunk;
3688
3689
3690         /* Delete backwards so that we don't end up with holes if
3691          * power is lost part-way through the operation.
3692          */
3693         for (i = last_del; i >= start_del; i--) {
3694                 /* NB this could be optimised somewhat,
3695                  * eg. could retrieve the tags and write them without
3696                  * using yaffs_chunk_del
3697                  */
3698
3699                 chunk_id = yaffs_find_del_file_chunk(in, i, NULL);
3700
3701                 if (chunk_id < 1)
3702                         continue;
3703
3704                 if (chunk_id <
3705                     (dev->internal_start_block * dev->param.chunks_per_block) ||
3706                     chunk_id >=
3707                     ((dev->internal_end_block + 1) *
3708                       dev->param.chunks_per_block)) {
3709                         yaffs_trace(YAFFS_TRACE_ALWAYS,
3710                                 "Found daft chunk_id %d for %d",
3711                                 chunk_id, i);
3712                 } else {
3713                         in->n_data_chunks--;
3714                         yaffs_chunk_del(dev, chunk_id, 1, __LINE__);
3715                 }
3716         }
3717 }
3718
3719 void yaffs_resize_file_down(struct yaffs_obj *obj, loff_t new_size)
3720 {
3721         int new_full;
3722         u32 new_partial;
3723         struct yaffs_dev *dev = obj->my_dev;
3724
3725         yaffs_addr_to_chunk(dev, new_size, &new_full, &new_partial);
3726
3727         yaffs_prune_chunks(obj, new_size);
3728
3729         if (new_partial != 0) {
3730                 int last_chunk = 1 + new_full;
3731                 u8 *local_buffer = yaffs_get_temp_buffer(dev);
3732
3733                 /* Rewrite the last chunk with its new size and zero pad */
3734                 yaffs_rd_data_obj(obj, last_chunk, local_buffer);
3735                 memset(local_buffer + new_partial, 0,
3736                        dev->data_bytes_per_chunk - new_partial);
3737
3738                 yaffs_wr_data_obj(obj, last_chunk, local_buffer,
3739                                   new_partial, 1);
3740
3741                 yaffs_release_temp_buffer(dev, local_buffer);
3742         }
3743
3744         obj->variant.file_variant.file_size = new_size;
3745
3746         yaffs_prune_tree(dev, &obj->variant.file_variant);
3747 }
3748
3749 int yaffs_resize_file(struct yaffs_obj *in, loff_t new_size)
3750 {
3751         struct yaffs_dev *dev = in->my_dev;
3752         int old_size = in->variant.file_variant.file_size;
3753
3754         yaffs_flush_file_cache(in);
3755         yaffs_invalidate_whole_cache(in);
3756
3757         yaffs_check_gc(dev, 0);
3758
3759         if (in->variant_type != YAFFS_OBJECT_TYPE_FILE)
3760                 return YAFFS_FAIL;
3761
3762         if (new_size == old_size)
3763                 return YAFFS_OK;
3764
3765         if (new_size > old_size) {
3766                 yaffs2_handle_hole(in, new_size);
3767                 in->variant.file_variant.file_size = new_size;
3768         } else {
3769                 /* new_size < old_size */
3770                 yaffs_resize_file_down(in, new_size);
3771         }
3772
3773         /* Write a new object header to reflect the resize.
3774          * show we've shrunk the file, if need be
3775          * Do this only if the file is not in the deleted directories
3776          * and is not shadowed.
3777          */
3778         if (in->parent &&
3779             !in->is_shadowed &&
3780             in->parent->obj_id != YAFFS_OBJECTID_UNLINKED &&
3781             in->parent->obj_id != YAFFS_OBJECTID_DELETED)
3782                 yaffs_update_oh(in, NULL, 0, 0, 0, NULL);
3783
3784         return YAFFS_OK;
3785 }
3786
3787 int yaffs_flush_file(struct yaffs_obj *in, int update_time, int data_sync)
3788 {
3789         if (!in->dirty)
3790                 return YAFFS_OK;
3791
3792         yaffs_flush_file_cache(in);
3793
3794         if (data_sync)
3795                 return YAFFS_OK;
3796
3797         if (update_time)
3798                 yaffs_load_current_time(in, 0, 0);
3799
3800         return (yaffs_update_oh(in, NULL, 0, 0, 0, NULL) >= 0) ?
3801                                 YAFFS_OK : YAFFS_FAIL;
3802 }
3803
3804
3805 /* yaffs_del_file deletes the whole file data
3806  * and the inode associated with the file.
3807  * It does not delete the links associated with the file.
3808  */
3809 static int yaffs_unlink_file_if_needed(struct yaffs_obj *in)
3810 {
3811         int ret_val;
3812         int del_now = 0;
3813         struct yaffs_dev *dev = in->my_dev;
3814
3815         if (!in->my_inode)
3816                 del_now = 1;
3817
3818         if (del_now) {
3819                 ret_val =
3820                     yaffs_change_obj_name(in, in->my_dev->del_dir,
3821                                           _Y("deleted"), 0, 0);
3822                 yaffs_trace(YAFFS_TRACE_TRACING,
3823                         "yaffs: immediate deletion of file %d",
3824                         in->obj_id);
3825                 in->deleted = 1;
3826                 in->my_dev->n_deleted_files++;
3827                 if (dev->param.disable_soft_del || dev->param.is_yaffs2)
3828                         yaffs_resize_file(in, 0);
3829                 yaffs_soft_del_file(in);
3830         } else {
3831                 ret_val =
3832                     yaffs_change_obj_name(in, in->my_dev->unlinked_dir,
3833                                           _Y("unlinked"), 0, 0);
3834         }
3835         return ret_val;
3836 }
3837
3838 int yaffs_del_file(struct yaffs_obj *in)
3839 {
3840         int ret_val = YAFFS_OK;
3841         int deleted;    /* Need to cache value on stack if in is freed */
3842         struct yaffs_dev *dev = in->my_dev;
3843
3844         if (dev->param.disable_soft_del || dev->param.is_yaffs2)
3845                 yaffs_resize_file(in, 0);
3846
3847         if (in->n_data_chunks > 0) {
3848                 /* Use soft deletion if there is data in the file.
3849                  * That won't be the case if it has been resized to zero.
3850                  */
3851                 if (!in->unlinked)
3852                         ret_val = yaffs_unlink_file_if_needed(in);
3853
3854                 deleted = in->deleted;
3855
3856                 if (ret_val == YAFFS_OK && in->unlinked && !in->deleted) {
3857                         in->deleted = 1;
3858                         deleted = 1;
3859                         in->my_dev->n_deleted_files++;
3860                         yaffs_soft_del_file(in);
3861                 }
3862                 return deleted ? YAFFS_OK : YAFFS_FAIL;
3863         } else {
3864                 /* The file has no data chunks so we toss it immediately */
3865                 yaffs_free_tnode(in->my_dev, in->variant.file_variant.top);
3866                 in->variant.file_variant.top = NULL;
3867                 yaffs_generic_obj_del(in);
3868
3869                 return YAFFS_OK;
3870         }
3871 }
3872
3873 int yaffs_is_non_empty_dir(struct yaffs_obj *obj)
3874 {
3875         return (obj &&
3876                 obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY) &&
3877                 !(list_empty(&obj->variant.dir_variant.children));
3878 }
3879
3880 static int yaffs_del_dir(struct yaffs_obj *obj)
3881 {
3882         /* First check that the directory is empty. */
3883         if (yaffs_is_non_empty_dir(obj))
3884                 return YAFFS_FAIL;
3885
3886         return yaffs_generic_obj_del(obj);
3887 }
3888
3889 static int yaffs_del_symlink(struct yaffs_obj *in)
3890 {
3891         kfree(in->variant.symlink_variant.alias);
3892         in->variant.symlink_variant.alias = NULL;
3893
3894         return yaffs_generic_obj_del(in);
3895 }
3896
3897 static int yaffs_del_link(struct yaffs_obj *in)
3898 {
3899         /* remove this hardlink from the list associated with the equivalent
3900          * object
3901          */
3902         list_del_init(&in->hard_links);
3903         return yaffs_generic_obj_del(in);
3904 }
3905
3906 int yaffs_del_obj(struct yaffs_obj *obj)
3907 {
3908         int ret_val = -1;
3909
3910         switch (obj->variant_type) {
3911         case YAFFS_OBJECT_TYPE_FILE:
3912                 ret_val = yaffs_del_file(obj);
3913                 break;
3914         case YAFFS_OBJECT_TYPE_DIRECTORY:
3915                 if (!list_empty(&obj->variant.dir_variant.dirty)) {
3916                         yaffs_trace(YAFFS_TRACE_BACKGROUND,
3917                                 "Remove object %d from dirty directories",
3918                                 obj->obj_id);
3919                         list_del_init(&obj->variant.dir_variant.dirty);
3920                 }
3921                 return yaffs_del_dir(obj);
3922                 break;
3923         case YAFFS_OBJECT_TYPE_SYMLINK:
3924                 ret_val = yaffs_del_symlink(obj);
3925                 break;
3926         case YAFFS_OBJECT_TYPE_HARDLINK:
3927                 ret_val = yaffs_del_link(obj);
3928                 break;
3929         case YAFFS_OBJECT_TYPE_SPECIAL:
3930                 ret_val = yaffs_generic_obj_del(obj);
3931                 break;
3932         case YAFFS_OBJECT_TYPE_UNKNOWN:
3933                 ret_val = 0;
3934                 break;          /* should not happen. */
3935         }
3936         return ret_val;
3937 }
3938
3939 static int yaffs_unlink_worker(struct yaffs_obj *obj)
3940 {
3941         int del_now = 0;
3942
3943         if (!obj)
3944                 return YAFFS_FAIL;
3945
3946         if (!obj->my_inode)
3947                 del_now = 1;
3948
3949         yaffs_update_parent(obj->parent);
3950
3951         if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
3952                 return yaffs_del_link(obj);
3953         } else if (!list_empty(&obj->hard_links)) {
3954                 /* Curve ball: We're unlinking an object that has a hardlink.
3955                  *
3956                  * This problem arises because we are not strictly following
3957                  * The Linux link/inode model.
3958                  *
3959                  * We can't really delete the object.
3960                  * Instead, we do the following:
3961                  * - Select a hardlink.
3962                  * - Unhook it from the hard links
3963                  * - Move it from its parent directory so that the rename works.
3964                  * - Rename the object to the hardlink's name.
3965                  * - Delete the hardlink
3966                  */
3967
3968                 struct yaffs_obj *hl;
3969                 struct yaffs_obj *parent;
3970                 int ret_val;
3971                 YCHAR name[YAFFS_MAX_NAME_LENGTH + 1];
3972
3973                 hl = list_entry(obj->hard_links.next, struct yaffs_obj,
3974                                 hard_links);
3975
3976                 yaffs_get_obj_name(hl, name, YAFFS_MAX_NAME_LENGTH + 1);
3977                 parent = hl->parent;
3978
3979                 list_del_init(&hl->hard_links);
3980
3981                 yaffs_add_obj_to_dir(obj->my_dev->unlinked_dir, hl);
3982
3983                 ret_val = yaffs_change_obj_name(obj, parent, name, 0, 0);
3984
3985                 if (ret_val == YAFFS_OK)
3986                         ret_val = yaffs_generic_obj_del(hl);
3987
3988                 return ret_val;
3989
3990         } else if (del_now) {
3991                 switch (obj->variant_type) {
3992                 case YAFFS_OBJECT_TYPE_FILE:
3993                         return yaffs_del_file(obj);
3994                         break;
3995                 case YAFFS_OBJECT_TYPE_DIRECTORY:
3996                         list_del_init(&obj->variant.dir_variant.dirty);
3997                         return yaffs_del_dir(obj);
3998                         break;
3999                 case YAFFS_OBJECT_TYPE_SYMLINK:
4000                         return yaffs_del_symlink(obj);
4001                         break;
4002                 case YAFFS_OBJECT_TYPE_SPECIAL:
4003                         return yaffs_generic_obj_del(obj);
4004                         break;
4005                 case YAFFS_OBJECT_TYPE_HARDLINK:
4006                 case YAFFS_OBJECT_TYPE_UNKNOWN:
4007                 default:
4008                         return YAFFS_FAIL;
4009                 }
4010         } else if (yaffs_is_non_empty_dir(obj)) {
4011                 return YAFFS_FAIL;
4012         } else {
4013                 return yaffs_change_obj_name(obj, obj->my_dev->unlinked_dir,
4014                                                 _Y("unlinked"), 0, 0);
4015         }
4016 }
4017
4018 static int yaffs_unlink_obj(struct yaffs_obj *obj)
4019 {
4020         if (obj && obj->unlink_allowed)
4021                 return yaffs_unlink_worker(obj);
4022
4023         return YAFFS_FAIL;
4024 }
4025
4026 int yaffs_unlinker(struct yaffs_obj *dir, const YCHAR *name)
4027 {
4028         struct yaffs_obj *obj;
4029
4030         obj = yaffs_find_by_name(dir, name);
4031         return yaffs_unlink_obj(obj);
4032 }
4033
4034 /* Note:
4035  * If old_name is NULL then we take old_dir as the object to be renamed.
4036  */
4037 int yaffs_rename_obj(struct yaffs_obj *old_dir, const YCHAR *old_name,
4038                      struct yaffs_obj *new_dir, const YCHAR *new_name)
4039 {
4040         struct yaffs_obj *obj = NULL;
4041         struct yaffs_obj *existing_target = NULL;
4042         int force = 0;
4043         int result;
4044         struct yaffs_dev *dev;
4045
4046         if (!old_dir || old_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4047                 BUG();
4048                 return YAFFS_FAIL;
4049         }
4050         if (!new_dir || new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4051                 BUG();
4052                 return YAFFS_FAIL;
4053         }
4054
4055         dev = old_dir->my_dev;
4056
4057 #ifdef CONFIG_YAFFS_CASE_INSENSITIVE
4058         /* Special case for case insemsitive systems.
4059          * While look-up is case insensitive, the name isn't.
4060          * Therefore we might want to change x.txt to X.txt
4061          */
4062         if (old_dir == new_dir &&
4063                 old_name && new_name &&
4064                 strcmp(old_name, new_name) == 0)
4065                 force = 1;
4066 #endif
4067
4068         if (strnlen(new_name, YAFFS_MAX_NAME_LENGTH + 1) >
4069             YAFFS_MAX_NAME_LENGTH)
4070                 /* ENAMETOOLONG */
4071                 return YAFFS_FAIL;
4072
4073         if (old_name)
4074                 obj = yaffs_find_by_name(old_dir, old_name);
4075         else{
4076                 obj = old_dir;
4077                 old_dir = obj->parent;
4078         }
4079
4080         if (obj && obj->rename_allowed) {
4081                 /* Now handle an existing target, if there is one */
4082                 existing_target = yaffs_find_by_name(new_dir, new_name);
4083                 if (yaffs_is_non_empty_dir(existing_target)) {
4084                         return YAFFS_FAIL;      /* ENOTEMPTY */
4085                 } else if (existing_target && existing_target != obj) {
4086                         /* Nuke the target first, using shadowing,
4087                          * but only if it isn't the same object.
4088                          *
4089                          * Note we must disable gc here otherwise it can mess
4090                          * up the shadowing.
4091                          *
4092                          */
4093                         dev->gc_disable = 1;
4094                         yaffs_change_obj_name(obj, new_dir, new_name, force,
4095                                               existing_target->obj_id);
4096                         existing_target->is_shadowed = 1;
4097                         yaffs_unlink_obj(existing_target);
4098                         dev->gc_disable = 0;
4099                 }
4100
4101                 result = yaffs_change_obj_name(obj, new_dir, new_name, 1, 0);
4102
4103                 yaffs_update_parent(old_dir);
4104                 if (new_dir != old_dir)
4105                         yaffs_update_parent(new_dir);
4106
4107                 return result;
4108         }
4109         return YAFFS_FAIL;
4110 }
4111
4112 /*----------------------- Initialisation Scanning ---------------------- */
4113
4114 void yaffs_handle_shadowed_obj(struct yaffs_dev *dev, int obj_id,
4115                                int backward_scanning)
4116 {
4117         struct yaffs_obj *obj;
4118
4119         if (backward_scanning) {
4120                 /* Handle YAFFS2 case (backward scanning)
4121                  * If the shadowed object exists then ignore.
4122                  */
4123                 obj = yaffs_find_by_number(dev, obj_id);
4124                 if (obj)
4125                         return;
4126         }
4127
4128         /* Let's create it (if it does not exist) assuming it is a file so that
4129          * it can do shrinking etc.
4130          * We put it in unlinked dir to be cleaned up after the scanning
4131          */
4132         obj =
4133             yaffs_find_or_create_by_number(dev, obj_id, YAFFS_OBJECT_TYPE_FILE);
4134         if (!obj)
4135                 return;
4136         obj->is_shadowed = 1;
4137         yaffs_add_obj_to_dir(dev->unlinked_dir, obj);
4138         obj->variant.file_variant.shrink_size = 0;
4139         obj->valid = 1;         /* So that we don't read any other info. */
4140 }
4141
4142 void yaffs_link_fixup(struct yaffs_dev *dev, struct list_head *hard_list)
4143 {
4144         struct list_head *lh;
4145         struct list_head *save;
4146         struct yaffs_obj *hl;
4147         struct yaffs_obj *in;
4148
4149         list_for_each_safe(lh, save, hard_list) {
4150                 hl = list_entry(lh, struct yaffs_obj, hard_links);
4151                 in = yaffs_find_by_number(dev,
4152                                         hl->variant.hardlink_variant.equiv_id);
4153
4154                 if (in) {
4155                         /* Add the hardlink pointers */
4156                         hl->variant.hardlink_variant.equiv_obj = in;
4157                         list_add(&hl->hard_links, &in->hard_links);
4158                 } else {
4159                         /* Todo Need to report/handle this better.
4160                          * Got a problem... hardlink to a non-existant object
4161                          */
4162                         hl->variant.hardlink_variant.equiv_obj = NULL;
4163                         INIT_LIST_HEAD(&hl->hard_links);
4164                 }
4165         }
4166 }
4167
4168 static void yaffs_strip_deleted_objs(struct yaffs_dev *dev)
4169 {
4170         /*
4171          *  Sort out state of unlinked and deleted objects after scanning.
4172          */
4173         struct list_head *i;
4174         struct list_head *n;
4175         struct yaffs_obj *l;
4176
4177         if (dev->read_only)
4178                 return;
4179
4180         /* Soft delete all the unlinked files */
4181         list_for_each_safe(i, n,
4182                            &dev->unlinked_dir->variant.dir_variant.children) {
4183                 l = list_entry(i, struct yaffs_obj, siblings);
4184                 yaffs_del_obj(l);
4185         }
4186
4187         list_for_each_safe(i, n, &dev->del_dir->variant.dir_variant.children) {
4188                 l = list_entry(i, struct yaffs_obj, siblings);
4189                 yaffs_del_obj(l);
4190         }
4191 }
4192
4193 /*
4194  * This code iterates through all the objects making sure that they are rooted.
4195  * Any unrooted objects are re-rooted in lost+found.
4196  * An object needs to be in one of:
4197  * - Directly under deleted, unlinked
4198  * - Directly or indirectly under root.
4199  *
4200  * Note:
4201  *  This code assumes that we don't ever change the current relationships
4202  *  between directories:
4203  *   root_dir->parent == unlinked_dir->parent == del_dir->parent == NULL
4204  *   lost-n-found->parent == root_dir
4205  *
4206  * This fixes the problem where directories might have inadvertently been
4207  * deleted leaving the object "hanging" without being rooted in the
4208  * directory tree.
4209  */
4210
4211 static int yaffs_has_null_parent(struct yaffs_dev *dev, struct yaffs_obj *obj)
4212 {
4213         return (obj == dev->del_dir ||
4214                 obj == dev->unlinked_dir || obj == dev->root_dir);
4215 }
4216
4217 static void yaffs_fix_hanging_objs(struct yaffs_dev *dev)
4218 {
4219         struct yaffs_obj *obj;
4220         struct yaffs_obj *parent;
4221         int i;
4222         struct list_head *lh;
4223         struct list_head *n;
4224         int depth_limit;
4225         int hanging;
4226
4227         if (dev->read_only)
4228                 return;
4229
4230         /* Iterate through the objects in each hash entry,
4231          * looking at each object.
4232          * Make sure it is rooted.
4233          */
4234
4235         for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
4236                 list_for_each_safe(lh, n, &dev->obj_bucket[i].list) {
4237                         obj = list_entry(lh, struct yaffs_obj, hash_link);
4238                         parent = obj->parent;
4239
4240                         if (yaffs_has_null_parent(dev, obj)) {
4241                                 /* These directories are not hanging */
4242                                 hanging = 0;
4243                         } else if (!parent ||
4244                                    parent->variant_type !=
4245                                    YAFFS_OBJECT_TYPE_DIRECTORY) {
4246                                 hanging = 1;
4247                         } else if (yaffs_has_null_parent(dev, parent)) {
4248                                 hanging = 0;
4249                         } else {
4250                                 /*
4251                                  * Need to follow the parent chain to
4252                                  * see if it is hanging.
4253                                  */
4254                                 hanging = 0;
4255                                 depth_limit = 100;
4256
4257                                 while (parent != dev->root_dir &&
4258                                        parent->parent &&
4259                                        parent->parent->variant_type ==
4260                                        YAFFS_OBJECT_TYPE_DIRECTORY &&
4261                                        depth_limit > 0) {
4262                                         parent = parent->parent;
4263                                         depth_limit--;
4264                                 }
4265                                 if (parent != dev->root_dir)
4266                                         hanging = 1;
4267                         }
4268                         if (hanging) {
4269                                 yaffs_trace(YAFFS_TRACE_SCAN,
4270                                         "Hanging object %d moved to lost and found",
4271                                         obj->obj_id);
4272                                 yaffs_add_obj_to_dir(dev->lost_n_found, obj);
4273                         }
4274                 }
4275         }
4276 }
4277
4278 /*
4279  * Delete directory contents for cleaning up lost and found.
4280  */
4281 static void yaffs_del_dir_contents(struct yaffs_obj *dir)
4282 {
4283         struct yaffs_obj *obj;
4284         struct list_head *lh;
4285         struct list_head *n;
4286
4287         if (dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
4288                 BUG();
4289
4290         list_for_each_safe(lh, n, &dir->variant.dir_variant.children) {
4291                 obj = list_entry(lh, struct yaffs_obj, siblings);
4292                 if (obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY)
4293                         yaffs_del_dir_contents(obj);
4294                 yaffs_trace(YAFFS_TRACE_SCAN,
4295                         "Deleting lost_found object %d",
4296                         obj->obj_id);
4297                 yaffs_unlink_obj(obj);
4298         }
4299 }
4300
4301 static void yaffs_empty_l_n_f(struct yaffs_dev *dev)
4302 {
4303         yaffs_del_dir_contents(dev->lost_n_found);
4304 }
4305
4306
4307 struct yaffs_obj *yaffs_find_by_name(struct yaffs_obj *directory,
4308                                      const YCHAR *name)
4309 {
4310         int sum;
4311         struct list_head *i;
4312         YCHAR buffer[YAFFS_MAX_NAME_LENGTH + 1];
4313         struct yaffs_obj *l;
4314
4315         if (!name)
4316                 return NULL;
4317
4318         if (!directory) {
4319                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4320                         "tragedy: yaffs_find_by_name: null pointer directory"
4321                         );
4322                 BUG();
4323                 return NULL;
4324         }
4325         if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4326                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4327                         "tragedy: yaffs_find_by_name: non-directory"
4328                         );
4329                 BUG();
4330         }
4331
4332         sum = yaffs_calc_name_sum(name);
4333
4334         list_for_each(i, &directory->variant.dir_variant.children) {
4335                 l = list_entry(i, struct yaffs_obj, siblings);
4336
4337                 if (l->parent != directory)
4338                         BUG();
4339
4340                 yaffs_check_obj_details_loaded(l);
4341
4342                 /* Special case for lost-n-found */
4343                 if (l->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
4344                         if (!strcmp(name, YAFFS_LOSTNFOUND_NAME))
4345                                 return l;
4346                 } else if (l->sum == sum || l->hdr_chunk <= 0) {
4347                         /* LostnFound chunk called Objxxx
4348                          * Do a real check
4349                          */
4350                         yaffs_get_obj_name(l, buffer,
4351                                 YAFFS_MAX_NAME_LENGTH + 1);
4352                         if (strncmp(name, buffer, YAFFS_MAX_NAME_LENGTH) == 0)
4353                                 return l;
4354                 }
4355         }
4356         return NULL;
4357 }
4358
4359 /* GetEquivalentObject dereferences any hard links to get to the
4360  * actual object.
4361  */
4362
4363 struct yaffs_obj *yaffs_get_equivalent_obj(struct yaffs_obj *obj)
4364 {
4365         if (obj && obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
4366                 obj = obj->variant.hardlink_variant.equiv_obj;
4367                 yaffs_check_obj_details_loaded(obj);
4368         }
4369         return obj;
4370 }
4371
4372 /*
4373  *  A note or two on object names.
4374  *  * If the object name is missing, we then make one up in the form objnnn
4375  *
4376  *  * ASCII names are stored in the object header's name field from byte zero
4377  *  * Unicode names are historically stored starting from byte zero.
4378  *
4379  * Then there are automatic Unicode names...
4380  * The purpose of these is to save names in a way that can be read as
4381  * ASCII or Unicode names as appropriate, thus allowing a Unicode and ASCII
4382  * system to share files.
4383  *
4384  * These automatic unicode are stored slightly differently...
4385  *  - If the name can fit in the ASCII character space then they are saved as
4386  *    ascii names as per above.
4387  *  - If the name needs Unicode then the name is saved in Unicode
4388  *    starting at oh->name[1].
4389
4390  */
4391 static void yaffs_fix_null_name(struct yaffs_obj *obj, YCHAR *name,
4392                                 int buffer_size)
4393 {
4394         /* Create an object name if we could not find one. */
4395         if (strnlen(name, YAFFS_MAX_NAME_LENGTH) == 0) {
4396                 YCHAR local_name[20];
4397                 YCHAR num_string[20];
4398                 YCHAR *x = &num_string[19];
4399                 unsigned v = obj->obj_id;
4400                 num_string[19] = 0;
4401                 while (v > 0) {
4402                         x--;
4403                         *x = '0' + (v % 10);
4404                         v /= 10;
4405                 }
4406                 /* make up a name */
4407                 strcpy(local_name, YAFFS_LOSTNFOUND_PREFIX);
4408                 strcat(local_name, x);
4409                 strncpy(name, local_name, buffer_size - 1);
4410         }
4411 }
4412
4413 int yaffs_get_obj_name(struct yaffs_obj *obj, YCHAR *name, int buffer_size)
4414 {
4415         memset(name, 0, buffer_size * sizeof(YCHAR));
4416         yaffs_check_obj_details_loaded(obj);
4417         if (obj->obj_id == YAFFS_OBJECTID_LOSTNFOUND)
4418                 strncpy(name, YAFFS_LOSTNFOUND_NAME, buffer_size - 1);
4419 #ifndef CONFIG_YAFFS_NO_SHORT_NAMES
4420         else if (obj->short_name[0])
4421                 strcpy(name, obj->short_name);
4422 #endif
4423         else if (obj->hdr_chunk > 0) {
4424                 int result;
4425                 u8 *buffer = yaffs_get_temp_buffer(obj->my_dev);
4426
4427                 struct yaffs_obj_hdr *oh = (struct yaffs_obj_hdr *)buffer;
4428
4429                 memset(buffer, 0, obj->my_dev->data_bytes_per_chunk);
4430
4431                 if (obj->hdr_chunk > 0) {
4432                         result = yaffs_rd_chunk_tags_nand(obj->my_dev,
4433                                                           obj->hdr_chunk,
4434                                                           buffer, NULL);
4435                 }
4436                 yaffs_load_name_from_oh(obj->my_dev, name, oh->name,
4437                                         buffer_size);
4438
4439                 yaffs_release_temp_buffer(obj->my_dev, buffer);
4440         }
4441
4442         yaffs_fix_null_name(obj, name, buffer_size);
4443
4444         return strnlen(name, YAFFS_MAX_NAME_LENGTH);
4445 }
4446
4447 int yaffs_get_obj_length(struct yaffs_obj *obj)
4448 {
4449         /* Dereference any hard linking */
4450         obj = yaffs_get_equivalent_obj(obj);
4451
4452         if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
4453                 return obj->variant.file_variant.file_size;
4454         if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
4455                 if (!obj->variant.symlink_variant.alias)
4456                         return 0;
4457                 return strnlen(obj->variant.symlink_variant.alias,
4458                                      YAFFS_MAX_ALIAS_LENGTH);
4459         } else {
4460                 /* Only a directory should drop through to here */
4461                 return obj->my_dev->data_bytes_per_chunk;
4462         }
4463 }
4464
4465 int yaffs_get_obj_link_count(struct yaffs_obj *obj)
4466 {
4467         int count = 0;
4468         struct list_head *i;
4469
4470         if (!obj->unlinked)
4471                 count++;        /* the object itself */
4472
4473         list_for_each(i, &obj->hard_links)
4474             count++;            /* add the hard links; */
4475
4476         return count;
4477 }
4478
4479 int yaffs_get_obj_inode(struct yaffs_obj *obj)
4480 {
4481         obj = yaffs_get_equivalent_obj(obj);
4482
4483         return obj->obj_id;
4484 }
4485
4486 unsigned yaffs_get_obj_type(struct yaffs_obj *obj)
4487 {
4488         obj = yaffs_get_equivalent_obj(obj);
4489
4490         switch (obj->variant_type) {
4491         case YAFFS_OBJECT_TYPE_FILE:
4492                 return DT_REG;
4493                 break;
4494         case YAFFS_OBJECT_TYPE_DIRECTORY:
4495                 return DT_DIR;
4496                 break;
4497         case YAFFS_OBJECT_TYPE_SYMLINK:
4498                 return DT_LNK;
4499                 break;
4500         case YAFFS_OBJECT_TYPE_HARDLINK:
4501                 return DT_REG;
4502                 break;
4503         case YAFFS_OBJECT_TYPE_SPECIAL:
4504                 if (S_ISFIFO(obj->yst_mode))
4505                         return DT_FIFO;
4506                 if (S_ISCHR(obj->yst_mode))
4507                         return DT_CHR;
4508                 if (S_ISBLK(obj->yst_mode))
4509                         return DT_BLK;
4510                 if (S_ISSOCK(obj->yst_mode))
4511                         return DT_SOCK;
4512                 return DT_REG;
4513                 break;
4514         default:
4515                 return DT_REG;
4516                 break;
4517         }
4518 }
4519
4520 YCHAR *yaffs_get_symlink_alias(struct yaffs_obj *obj)
4521 {
4522         obj = yaffs_get_equivalent_obj(obj);
4523         if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK)
4524                 return yaffs_clone_str(obj->variant.symlink_variant.alias);
4525         else
4526                 return yaffs_clone_str(_Y(""));
4527 }
4528
4529 /*--------------------------- Initialisation code -------------------------- */
4530
4531 static int yaffs_check_dev_fns(const struct yaffs_dev *dev)
4532 {
4533         /* Common functions, gotta have */
4534         if (!dev->param.erase_fn || !dev->param.initialise_flash_fn)
4535                 return 0;
4536
4537 #ifdef CONFIG_YAFFS_YAFFS2
4538
4539         /* Can use the "with tags" style interface for yaffs1 or yaffs2 */
4540         if (dev->param.write_chunk_tags_fn &&
4541             dev->param.read_chunk_tags_fn &&
4542             !dev->param.write_chunk_fn &&
4543             !dev->param.read_chunk_fn &&
4544             dev->param.bad_block_fn && dev->param.query_block_fn)
4545                 return 1;
4546 #endif
4547
4548         /* Can use the "spare" style interface for yaffs1 */
4549         if (!dev->param.is_yaffs2 &&
4550             !dev->param.write_chunk_tags_fn &&
4551             !dev->param.read_chunk_tags_fn &&
4552             dev->param.write_chunk_fn &&
4553             dev->param.read_chunk_fn &&
4554             !dev->param.bad_block_fn && !dev->param.query_block_fn)
4555                 return 1;
4556
4557         return 0;               /* bad */
4558 }
4559
4560 static int yaffs_create_initial_dir(struct yaffs_dev *dev)
4561 {
4562         /* Initialise the unlinked, deleted, root and lost+found directories */
4563         dev->lost_n_found = dev->root_dir = NULL;
4564         dev->unlinked_dir = dev->del_dir = NULL;
4565         dev->unlinked_dir =
4566             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_UNLINKED, S_IFDIR);
4567         dev->del_dir =
4568             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_DELETED, S_IFDIR);
4569         dev->root_dir =
4570             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_ROOT,
4571                                   YAFFS_ROOT_MODE | S_IFDIR);
4572         dev->lost_n_found =
4573             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_LOSTNFOUND,
4574                                   YAFFS_LOSTNFOUND_MODE | S_IFDIR);
4575
4576         if (dev->lost_n_found && dev->root_dir && dev->unlinked_dir
4577             && dev->del_dir) {
4578                 yaffs_add_obj_to_dir(dev->root_dir, dev->lost_n_found);
4579                 return YAFFS_OK;
4580         }
4581         return YAFFS_FAIL;
4582 }
4583
4584 int yaffs_guts_initialise(struct yaffs_dev *dev)
4585 {
4586         int init_failed = 0;
4587         unsigned x;
4588         int bits;
4589
4590         yaffs_trace(YAFFS_TRACE_TRACING, "yaffs: yaffs_guts_initialise()");
4591
4592         /* Check stuff that must be set */
4593
4594         if (!dev) {
4595                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4596                         "yaffs: Need a device"
4597                         );
4598                 return YAFFS_FAIL;
4599         }
4600
4601         if (dev->is_mounted) {
4602                 yaffs_trace(YAFFS_TRACE_ALWAYS, "device already mounted");
4603                 return YAFFS_FAIL;
4604         }
4605
4606         dev->internal_start_block = dev->param.start_block;
4607         dev->internal_end_block = dev->param.end_block;
4608         dev->block_offset = 0;
4609         dev->chunk_offset = 0;
4610         dev->n_free_chunks = 0;
4611
4612         dev->gc_block = 0;
4613
4614         if (dev->param.start_block == 0) {
4615                 dev->internal_start_block = dev->param.start_block + 1;
4616                 dev->internal_end_block = dev->param.end_block + 1;
4617                 dev->block_offset = 1;
4618                 dev->chunk_offset = dev->param.chunks_per_block;
4619         }
4620
4621         /* Check geometry parameters. */
4622
4623         if ((!dev->param.inband_tags && dev->param.is_yaffs2 &&
4624                 dev->param.total_bytes_per_chunk < 1024) ||
4625                 (!dev->param.is_yaffs2 &&
4626                         dev->param.total_bytes_per_chunk < 512) ||
4627                 (dev->param.inband_tags && !dev->param.is_yaffs2) ||
4628                  dev->param.chunks_per_block < 2 ||
4629                  dev->param.n_reserved_blocks < 2 ||
4630                 dev->internal_start_block <= 0 ||
4631                 dev->internal_end_block <= 0 ||
4632                 dev->internal_end_block <=
4633                 (dev->internal_start_block + dev->param.n_reserved_blocks + 2)
4634                 ) {
4635                 /* otherwise it is too small */
4636                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4637                         "NAND geometry problems: chunk size %d, type is yaffs%s, inband_tags %d ",
4638                         dev->param.total_bytes_per_chunk,
4639                         dev->param.is_yaffs2 ? "2" : "",
4640                         dev->param.inband_tags);
4641                 return YAFFS_FAIL;
4642         }
4643
4644         if (yaffs_init_nand(dev) != YAFFS_OK) {
4645                 yaffs_trace(YAFFS_TRACE_ALWAYS, "InitialiseNAND failed");
4646                 return YAFFS_FAIL;
4647         }
4648
4649         /* Sort out space for inband tags, if required */
4650         if (dev->param.inband_tags)
4651                 dev->data_bytes_per_chunk =
4652                     dev->param.total_bytes_per_chunk -
4653                     sizeof(struct yaffs_packed_tags2_tags_only);
4654         else
4655                 dev->data_bytes_per_chunk = dev->param.total_bytes_per_chunk;
4656
4657         /* Got the right mix of functions? */
4658         if (!yaffs_check_dev_fns(dev)) {
4659                 /* Function missing */
4660                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4661                         "device function(s) missing or wrong");
4662
4663                 return YAFFS_FAIL;
4664         }
4665
4666         /* Finished with most checks. Further checks happen later on too. */
4667
4668         dev->is_mounted = 1;
4669
4670         /* OK now calculate a few things for the device */
4671
4672         /*
4673          *  Calculate all the chunk size manipulation numbers:
4674          */
4675         x = dev->data_bytes_per_chunk;
4676         /* We always use dev->chunk_shift and dev->chunk_div */
4677         dev->chunk_shift = calc_shifts(x);
4678         x >>= dev->chunk_shift;
4679         dev->chunk_div = x;
4680         /* We only use chunk mask if chunk_div is 1 */
4681         dev->chunk_mask = (1 << dev->chunk_shift) - 1;
4682
4683         /*
4684          * Calculate chunk_grp_bits.
4685          * We need to find the next power of 2 > than internal_end_block
4686          */
4687
4688         x = dev->param.chunks_per_block * (dev->internal_end_block + 1);
4689
4690         bits = calc_shifts_ceiling(x);
4691
4692         /* Set up tnode width if wide tnodes are enabled. */
4693         if (!dev->param.wide_tnodes_disabled) {
4694                 /* bits must be even so that we end up with 32-bit words */
4695                 if (bits & 1)
4696                         bits++;
4697                 if (bits < 16)
4698                         dev->tnode_width = 16;
4699                 else
4700                         dev->tnode_width = bits;
4701         } else {
4702                 dev->tnode_width = 16;
4703         }
4704
4705         dev->tnode_mask = (1 << dev->tnode_width) - 1;
4706
4707         /* Level0 Tnodes are 16 bits or wider (if wide tnodes are enabled),
4708          * so if the bitwidth of the
4709          * chunk range we're using is greater than 16 we need
4710          * to figure out chunk shift and chunk_grp_size
4711          */
4712
4713         if (bits <= dev->tnode_width)
4714                 dev->chunk_grp_bits = 0;
4715         else
4716                 dev->chunk_grp_bits = bits - dev->tnode_width;
4717
4718         dev->tnode_size = (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8;
4719         if (dev->tnode_size < sizeof(struct yaffs_tnode))
4720                 dev->tnode_size = sizeof(struct yaffs_tnode);
4721
4722         dev->chunk_grp_size = 1 << dev->chunk_grp_bits;
4723
4724         if (dev->param.chunks_per_block < dev->chunk_grp_size) {
4725                 /* We have a problem because the soft delete won't work if
4726                  * the chunk group size > chunks per block.
4727                  * This can be remedied by using larger "virtual blocks".
4728                  */
4729                 yaffs_trace(YAFFS_TRACE_ALWAYS, "chunk group too large");
4730
4731                 return YAFFS_FAIL;
4732         }
4733
4734         /* Finished verifying the device, continue with initialisation */
4735
4736         /* More device initialisation */
4737         dev->all_gcs = 0;
4738         dev->passive_gc_count = 0;
4739         dev->oldest_dirty_gc_count = 0;
4740         dev->bg_gcs = 0;
4741         dev->gc_block_finder = 0;
4742         dev->buffered_block = -1;
4743         dev->doing_buffered_block_rewrite = 0;
4744         dev->n_deleted_files = 0;
4745         dev->n_bg_deletions = 0;
4746         dev->n_unlinked_files = 0;
4747         dev->n_ecc_fixed = 0;
4748         dev->n_ecc_unfixed = 0;
4749         dev->n_tags_ecc_fixed = 0;
4750         dev->n_tags_ecc_unfixed = 0;
4751         dev->n_erase_failures = 0;
4752         dev->n_erased_blocks = 0;
4753         dev->gc_disable = 0;
4754         dev->has_pending_prioritised_gc = 1;
4755                 /* Assume the worst for now, will get fixed on first GC */
4756         INIT_LIST_HEAD(&dev->dirty_dirs);
4757         dev->oldest_dirty_seq = 0;
4758         dev->oldest_dirty_block = 0;
4759
4760         /* Initialise temporary buffers and caches. */
4761         if (!yaffs_init_tmp_buffers(dev))
4762                 init_failed = 1;
4763
4764         dev->cache = NULL;
4765         dev->gc_cleanup_list = NULL;
4766
4767         if (!init_failed && dev->param.n_caches > 0) {
4768                 int i;
4769                 void *buf;
4770                 int cache_bytes =
4771                     dev->param.n_caches * sizeof(struct yaffs_cache);
4772
4773                 if (dev->param.n_caches > YAFFS_MAX_SHORT_OP_CACHES)
4774                         dev->param.n_caches = YAFFS_MAX_SHORT_OP_CACHES;
4775
4776                 dev->cache = kmalloc(cache_bytes, GFP_NOFS);
4777
4778                 buf = (u8 *) dev->cache;
4779
4780                 if (dev->cache)
4781                         memset(dev->cache, 0, cache_bytes);
4782
4783                 for (i = 0; i < dev->param.n_caches && buf; i++) {
4784                         dev->cache[i].object = NULL;
4785                         dev->cache[i].last_use = 0;
4786                         dev->cache[i].dirty = 0;
4787                         dev->cache[i].data = buf =
4788                             kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
4789                 }
4790                 if (!buf)
4791                         init_failed = 1;
4792
4793                 dev->cache_last_use = 0;
4794         }
4795
4796         dev->cache_hits = 0;
4797
4798         if (!init_failed) {
4799                 dev->gc_cleanup_list =
4800                     kmalloc(dev->param.chunks_per_block * sizeof(u32),
4801                                         GFP_NOFS);
4802                 if (!dev->gc_cleanup_list)
4803                         init_failed = 1;
4804         }
4805
4806         if (dev->param.is_yaffs2)
4807                 dev->param.use_header_file_size = 1;
4808
4809         if (!init_failed && !yaffs_init_blocks(dev))
4810                 init_failed = 1;
4811
4812         yaffs_init_tnodes_and_objs(dev);
4813
4814         if (!init_failed && !yaffs_create_initial_dir(dev))
4815                 init_failed = 1;
4816
4817         if(!init_failed && dev->param.is_yaffs2 && !yaffs_summary_init(dev))
4818                 init_failed = 1;
4819
4820         if (!init_failed) {
4821                 /* Now scan the flash. */
4822                 if (dev->param.is_yaffs2) {
4823                         if (yaffs2_checkpt_restore(dev)) {
4824                                 yaffs_check_obj_details_loaded(dev->root_dir);
4825                                 yaffs_trace(YAFFS_TRACE_CHECKPOINT |
4826                                         YAFFS_TRACE_MOUNT,
4827                                         "yaffs: restored from checkpoint"
4828                                         );
4829                         } else {
4830
4831                                 /* Clean up the mess caused by an aborted
4832                                  * checkpoint load then scan backwards.
4833                                  */
4834                                 yaffs_deinit_blocks(dev);
4835
4836                                 yaffs_deinit_tnodes_and_objs(dev);
4837
4838                                 dev->n_erased_blocks = 0;
4839                                 dev->n_free_chunks = 0;
4840                                 dev->alloc_block = -1;
4841                                 dev->alloc_page = -1;
4842                                 dev->n_deleted_files = 0;
4843                                 dev->n_unlinked_files = 0;
4844                                 dev->n_bg_deletions = 0;
4845
4846                                 if (!init_failed && !yaffs_init_blocks(dev))
4847                                         init_failed = 1;
4848
4849                                 yaffs_init_tnodes_and_objs(dev);
4850
4851                                 if (!init_failed
4852                                     && !yaffs_create_initial_dir(dev))
4853                                         init_failed = 1;
4854
4855                                 if (!init_failed && !yaffs2_scan_backwards(dev))
4856                                         init_failed = 1;
4857                         }
4858                 } else if (!yaffs1_scan(dev)) {
4859                         init_failed = 1;
4860                 }
4861
4862                 yaffs_strip_deleted_objs(dev);
4863                 yaffs_fix_hanging_objs(dev);
4864                 if (dev->param.empty_lost_n_found)
4865                         yaffs_empty_l_n_f(dev);
4866         }
4867
4868         if (init_failed) {
4869                 /* Clean up the mess */
4870                 yaffs_trace(YAFFS_TRACE_TRACING,
4871                   "yaffs: yaffs_guts_initialise() aborted.");
4872
4873                 yaffs_deinitialise(dev);
4874                 return YAFFS_FAIL;
4875         }
4876
4877         /* Zero out stats */
4878         dev->n_page_reads = 0;
4879         dev->n_page_writes = 0;
4880         dev->n_erasures = 0;
4881         dev->n_gc_copies = 0;
4882         dev->n_retired_writes = 0;
4883
4884         dev->n_retired_blocks = 0;
4885
4886         yaffs_verify_free_chunks(dev);
4887         yaffs_verify_blocks(dev);
4888
4889         /* Clean up any aborted checkpoint data */
4890         if (!dev->is_checkpointed && dev->blocks_in_checkpt > 0)
4891                 yaffs2_checkpt_invalidate(dev);
4892
4893         yaffs_trace(YAFFS_TRACE_TRACING,
4894           "yaffs: yaffs_guts_initialise() done.");
4895         return YAFFS_OK;
4896 }
4897
4898 void yaffs_deinitialise(struct yaffs_dev *dev)
4899 {
4900         if (dev->is_mounted) {
4901                 int i;
4902
4903                 yaffs_deinit_blocks(dev);
4904                 yaffs_deinit_tnodes_and_objs(dev);
4905                 yaffs_summary_deinit(dev);
4906
4907                 if (dev->param.n_caches > 0 && dev->cache) {
4908
4909                         for (i = 0; i < dev->param.n_caches; i++) {
4910                                 kfree(dev->cache[i].data);
4911                                 dev->cache[i].data = NULL;
4912                         }
4913
4914                         kfree(dev->cache);
4915                         dev->cache = NULL;
4916                 }
4917
4918                 kfree(dev->gc_cleanup_list);
4919
4920                 for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++)
4921                         kfree(dev->temp_buffer[i].buffer);
4922
4923                 dev->is_mounted = 0;
4924
4925                 if (dev->param.deinitialise_flash_fn)
4926                         dev->param.deinitialise_flash_fn(dev);
4927         }
4928 }
4929
4930 int yaffs_count_free_chunks(struct yaffs_dev *dev)
4931 {
4932         int n_free = 0;
4933         int b;
4934         struct yaffs_block_info *blk;
4935
4936         blk = dev->block_info;
4937         for (b = dev->internal_start_block; b <= dev->internal_end_block; b++) {
4938                 switch (blk->block_state) {
4939                 case YAFFS_BLOCK_STATE_EMPTY:
4940                 case YAFFS_BLOCK_STATE_ALLOCATING:
4941                 case YAFFS_BLOCK_STATE_COLLECTING:
4942                 case YAFFS_BLOCK_STATE_FULL:
4943                         n_free +=
4944                             (dev->param.chunks_per_block - blk->pages_in_use +
4945                              blk->soft_del_pages);
4946                         break;
4947                 default:
4948                         break;
4949                 }
4950                 blk++;
4951         }
4952         return n_free;
4953 }
4954
4955 int yaffs_get_n_free_chunks(struct yaffs_dev *dev)
4956 {
4957         /* This is what we report to the outside world */
4958         int n_free;
4959         int n_dirty_caches;
4960         int blocks_for_checkpt;
4961         int i;
4962
4963         n_free = dev->n_free_chunks;
4964         n_free += dev->n_deleted_files;
4965
4966         /* Now count and subtract the number of dirty chunks in the cache. */
4967
4968         for (n_dirty_caches = 0, i = 0; i < dev->param.n_caches; i++) {
4969                 if (dev->cache[i].dirty)
4970                         n_dirty_caches++;
4971         }
4972
4973         n_free -= n_dirty_caches;
4974
4975         n_free -=
4976             ((dev->param.n_reserved_blocks + 1) * dev->param.chunks_per_block);
4977
4978         /* Now figure checkpoint space and report that... */
4979         blocks_for_checkpt = yaffs_calc_checkpt_blocks_required(dev);
4980
4981         n_free -= (blocks_for_checkpt * dev->param.chunks_per_block);
4982
4983         if (n_free < 0)
4984                 n_free = 0;
4985
4986         return n_free;
4987 }