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         bi->has_summary=0;
2387
2388         yaffs_clear_chunk_bits(dev, block_no);
2389
2390         yaffs_trace(YAFFS_TRACE_ERASE, "Erased block %d", block_no);
2391 }
2392
2393 static inline int yaffs_gc_process_chunk(struct yaffs_dev *dev,
2394                                         struct yaffs_block_info *bi,
2395                                         int old_chunk, u8 *buffer)
2396 {
2397         int new_chunk;
2398         int mark_flash = 1;
2399         struct yaffs_ext_tags tags;
2400         struct yaffs_obj *object;
2401         int matching_chunk;
2402         int ret_val = YAFFS_OK;
2403
2404         memset(&tags, 0, sizeof(tags));
2405         yaffs_rd_chunk_tags_nand(dev, old_chunk,
2406                                  buffer, &tags);
2407         object = yaffs_find_by_number(dev, tags.obj_id);
2408
2409         yaffs_trace(YAFFS_TRACE_GC_DETAIL,
2410                 "Collecting chunk in block %d, %d %d %d ",
2411                 dev->gc_chunk, tags.obj_id,
2412                 tags.chunk_id, tags.n_bytes);
2413
2414         if (object && !yaffs_skip_verification(dev)) {
2415                 if (tags.chunk_id == 0)
2416                         matching_chunk =
2417                             object->hdr_chunk;
2418                 else if (object->soft_del)
2419                         /* Defeat the test */
2420                         matching_chunk = old_chunk;
2421                 else
2422                         matching_chunk =
2423                             yaffs_find_chunk_in_file
2424                             (object, tags.chunk_id,
2425                              NULL);
2426
2427                 if (old_chunk != matching_chunk)
2428                         yaffs_trace(YAFFS_TRACE_ERROR,
2429                                 "gc: page in gc mismatch: %d %d %d %d",
2430                                 old_chunk,
2431                                 matching_chunk,
2432                                 tags.obj_id,
2433                                 tags.chunk_id);
2434         }
2435
2436         if (!object) {
2437                 yaffs_trace(YAFFS_TRACE_ERROR,
2438                         "page %d in gc has no object: %d %d %d ",
2439                         old_chunk,
2440                         tags.obj_id, tags.chunk_id,
2441                         tags.n_bytes);
2442         }
2443
2444         if (object &&
2445             object->deleted &&
2446             object->soft_del && tags.chunk_id != 0) {
2447                 /* Data chunk in a soft deleted file,
2448                  * throw it away.
2449                  * It's a soft deleted data chunk,
2450                  * No need to copy this, just forget
2451                  * about it and fix up the object.
2452                  */
2453
2454                 /* Free chunks already includes
2455                  * softdeleted chunks, how ever this
2456                  * chunk is going to soon be really
2457                  * deleted which will increment free
2458                  * chunks. We have to decrement free
2459                  * chunks so this works out properly.
2460                  */
2461                 dev->n_free_chunks--;
2462                 bi->soft_del_pages--;
2463
2464                 object->n_data_chunks--;
2465                 if (object->n_data_chunks <= 0) {
2466                         /* remeber to clean up obj */
2467                         dev->gc_cleanup_list[dev->n_clean_ups] = tags.obj_id;
2468                         dev->n_clean_ups++;
2469                 }
2470                 mark_flash = 0;
2471         } else if (object) {
2472                 /* It's either a data chunk in a live
2473                  * file or an ObjectHeader, so we're
2474                  * interested in it.
2475                  * NB Need to keep the ObjectHeaders of
2476                  * deleted files until the whole file
2477                  * has been deleted off
2478                  */
2479                 tags.serial_number++;
2480                 dev->n_gc_copies++;
2481
2482                 if (tags.chunk_id == 0) {
2483                         /* It is an object Id,
2484                          * We need to nuke the
2485                          * shrinkheader flags since its
2486                          * work is done.
2487                          * Also need to clean up
2488                          * shadowing.
2489                          */
2490                         struct yaffs_obj_hdr *oh;
2491                         oh = (struct yaffs_obj_hdr *) buffer;
2492
2493                         oh->is_shrink = 0;
2494                         tags.extra_is_shrink = 0;
2495                         oh->shadows_obj = 0;
2496                         oh->inband_shadowed_obj_id = 0;
2497                         tags.extra_shadows = 0;
2498
2499                         /* Update file size */
2500                         if (object->variant_type == YAFFS_OBJECT_TYPE_FILE) {
2501                                 oh->file_size =
2502                                     object->variant.file_variant.file_size;
2503                                 tags.extra_length = oh->file_size;
2504                         }
2505
2506                         yaffs_verify_oh(object, oh, &tags, 1);
2507                         new_chunk =
2508                             yaffs_write_new_chunk(dev, (u8 *) oh, &tags, 1);
2509                 } else {
2510                         new_chunk =
2511                             yaffs_write_new_chunk(dev, buffer, &tags, 1);
2512                 }
2513
2514                 if (new_chunk < 0) {
2515                         ret_val = YAFFS_FAIL;
2516                 } else {
2517
2518                         /* Now fix up the Tnodes etc. */
2519
2520                         if (tags.chunk_id == 0) {
2521                                 /* It's a header */
2522                                 object->hdr_chunk = new_chunk;
2523                                 object->serial = tags.serial_number;
2524                         } else {
2525                                 /* It's a data chunk */
2526                                 yaffs_put_chunk_in_file(object, tags.chunk_id,
2527                                                         new_chunk, 0);
2528                         }
2529                 }
2530         }
2531         if (ret_val == YAFFS_OK)
2532                 yaffs_chunk_del(dev, old_chunk, mark_flash, __LINE__);
2533         return ret_val;
2534 }
2535
2536 static int yaffs_gc_block(struct yaffs_dev *dev, int block, int whole_block)
2537 {
2538         int old_chunk;
2539         int ret_val = YAFFS_OK;
2540         int i;
2541         int is_checkpt_block;
2542         int max_copies;
2543         int chunks_before = yaffs_get_erased_chunks(dev);
2544         int chunks_after;
2545         struct yaffs_block_info *bi = yaffs_get_block_info(dev, block);
2546
2547         is_checkpt_block = (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT);
2548
2549         yaffs_trace(YAFFS_TRACE_TRACING,
2550                 "Collecting block %d, in use %d, shrink %d, whole_block %d",
2551                 block, bi->pages_in_use, bi->has_shrink_hdr,
2552                 whole_block);
2553
2554         /*yaffs_verify_free_chunks(dev); */
2555
2556         if (bi->block_state == YAFFS_BLOCK_STATE_FULL)
2557                 bi->block_state = YAFFS_BLOCK_STATE_COLLECTING;
2558
2559         bi->has_shrink_hdr = 0; /* clear the flag so that the block can erase */
2560
2561         dev->gc_disable = 1;
2562
2563         yaffs_summary_gc(dev, block);
2564
2565         if (is_checkpt_block || !yaffs_still_some_chunks(dev, block)) {
2566                 yaffs_trace(YAFFS_TRACE_TRACING,
2567                         "Collecting block %d that has no chunks in use",
2568                         block);
2569                 yaffs_block_became_dirty(dev, block);
2570         } else {
2571
2572                 u8 *buffer = yaffs_get_temp_buffer(dev);
2573
2574                 yaffs_verify_blk(dev, bi, block);
2575
2576                 max_copies = (whole_block) ? dev->param.chunks_per_block : 5;
2577                 old_chunk = block * dev->param.chunks_per_block + dev->gc_chunk;
2578
2579                 for (/* init already done */ ;
2580                      ret_val == YAFFS_OK &&
2581                      dev->gc_chunk < dev->param.chunks_per_block &&
2582                      (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) &&
2583                      max_copies > 0;
2584                      dev->gc_chunk++, old_chunk++) {
2585                         if (yaffs_check_chunk_bit(dev, block, dev->gc_chunk)) {
2586                                 /* Page is in use and might need to be copied */
2587                                 max_copies--;
2588                                 ret_val = yaffs_gc_process_chunk(dev, bi,
2589                                                         old_chunk, buffer);
2590                         }
2591                 }
2592                 yaffs_release_temp_buffer(dev, buffer);
2593         }
2594
2595         yaffs_verify_collected_blk(dev, bi, block);
2596
2597         if (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
2598                 /*
2599                  * The gc did not complete. Set block state back to FULL
2600                  * because checkpointing does not restore gc.
2601                  */
2602                 bi->block_state = YAFFS_BLOCK_STATE_FULL;
2603         } else {
2604                 /* The gc completed. */
2605                 /* Do any required cleanups */
2606                 for (i = 0; i < dev->n_clean_ups; i++) {
2607                         /* Time to delete the file too */
2608                         struct yaffs_obj *object =
2609                             yaffs_find_by_number(dev, dev->gc_cleanup_list[i]);
2610                         if (object) {
2611                                 yaffs_free_tnode(dev,
2612                                           object->variant.file_variant.top);
2613                                 object->variant.file_variant.top = NULL;
2614                                 yaffs_trace(YAFFS_TRACE_GC,
2615                                         "yaffs: About to finally delete object %d",
2616                                         object->obj_id);
2617                                 yaffs_generic_obj_del(object);
2618                                 object->my_dev->n_deleted_files--;
2619                         }
2620
2621                 }
2622                 chunks_after = yaffs_get_erased_chunks(dev);
2623                 if (chunks_before >= chunks_after)
2624                         yaffs_trace(YAFFS_TRACE_GC,
2625                                 "gc did not increase free chunks before %d after %d",
2626                                 chunks_before, chunks_after);
2627                 dev->gc_block = 0;
2628                 dev->gc_chunk = 0;
2629                 dev->n_clean_ups = 0;
2630         }
2631
2632         dev->gc_disable = 0;
2633
2634         return ret_val;
2635 }
2636
2637 /*
2638  * find_gc_block() selects the dirtiest block (or close enough)
2639  * for garbage collection.
2640  */
2641
2642 static unsigned yaffs_find_gc_block(struct yaffs_dev *dev,
2643                                     int aggressive, int background)
2644 {
2645         int i;
2646         int iterations;
2647         unsigned selected = 0;
2648         int prioritised = 0;
2649         int prioritised_exist = 0;
2650         struct yaffs_block_info *bi;
2651         int threshold;
2652
2653         /* First let's see if we need to grab a prioritised block */
2654         if (dev->has_pending_prioritised_gc && !aggressive) {
2655                 dev->gc_dirtiest = 0;
2656                 bi = dev->block_info;
2657                 for (i = dev->internal_start_block;
2658                      i <= dev->internal_end_block && !selected; i++) {
2659
2660                         if (bi->gc_prioritise) {
2661                                 prioritised_exist = 1;
2662                                 if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
2663                                     yaffs_block_ok_for_gc(dev, bi)) {
2664                                         selected = i;
2665                                         prioritised = 1;
2666                                 }
2667                         }
2668                         bi++;
2669                 }
2670
2671                 /*
2672                  * If there is a prioritised block and none was selected then
2673                  * this happened because there is at least one old dirty block
2674                  * gumming up the works. Let's gc the oldest dirty block.
2675                  */
2676
2677                 if (prioritised_exist &&
2678                     !selected && dev->oldest_dirty_block > 0)
2679                         selected = dev->oldest_dirty_block;
2680
2681                 if (!prioritised_exist) /* None found, so we can clear this */
2682                         dev->has_pending_prioritised_gc = 0;
2683         }
2684
2685         /* If we're doing aggressive GC then we are happy to take a less-dirty
2686          * block, and search harder.
2687          * else (leasurely gc), then we only bother to do this if the
2688          * block has only a few pages in use.
2689          */
2690
2691         if (!selected) {
2692                 int pages_used;
2693                 int n_blocks =
2694                     dev->internal_end_block - dev->internal_start_block + 1;
2695                 if (aggressive) {
2696                         threshold = dev->param.chunks_per_block;
2697                         iterations = n_blocks;
2698                 } else {
2699                         int max_threshold;
2700
2701                         if (background)
2702                                 max_threshold = dev->param.chunks_per_block / 2;
2703                         else
2704                                 max_threshold = dev->param.chunks_per_block / 8;
2705
2706                         if (max_threshold < YAFFS_GC_PASSIVE_THRESHOLD)
2707                                 max_threshold = YAFFS_GC_PASSIVE_THRESHOLD;
2708
2709                         threshold = background ? (dev->gc_not_done + 2) * 2 : 0;
2710                         if (threshold < YAFFS_GC_PASSIVE_THRESHOLD)
2711                                 threshold = YAFFS_GC_PASSIVE_THRESHOLD;
2712                         if (threshold > max_threshold)
2713                                 threshold = max_threshold;
2714
2715                         iterations = n_blocks / 16 + 1;
2716                         if (iterations > 100)
2717                                 iterations = 100;
2718                 }
2719
2720                 for (i = 0;
2721                      i < iterations &&
2722                      (dev->gc_dirtiest < 1 ||
2723                       dev->gc_pages_in_use > YAFFS_GC_GOOD_ENOUGH);
2724                      i++) {
2725                         dev->gc_block_finder++;
2726                         if (dev->gc_block_finder < dev->internal_start_block ||
2727                             dev->gc_block_finder > dev->internal_end_block)
2728                                 dev->gc_block_finder =
2729                                     dev->internal_start_block;
2730
2731                         bi = yaffs_get_block_info(dev, dev->gc_block_finder);
2732
2733                         pages_used = bi->pages_in_use - bi->soft_del_pages;
2734
2735                         if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
2736                             pages_used < dev->param.chunks_per_block &&
2737                             (dev->gc_dirtiest < 1 ||
2738                              pages_used < dev->gc_pages_in_use) &&
2739                             yaffs_block_ok_for_gc(dev, bi)) {
2740                                 dev->gc_dirtiest = dev->gc_block_finder;
2741                                 dev->gc_pages_in_use = pages_used;
2742                         }
2743                 }
2744
2745                 if (dev->gc_dirtiest > 0 && dev->gc_pages_in_use <= threshold)
2746                         selected = dev->gc_dirtiest;
2747         }
2748
2749         /*
2750          * If nothing has been selected for a while, try the oldest dirty
2751          * because that's gumming up the works.
2752          */
2753
2754         if (!selected && dev->param.is_yaffs2 &&
2755             dev->gc_not_done >= (background ? 10 : 20)) {
2756                 yaffs2_find_oldest_dirty_seq(dev);
2757                 if (dev->oldest_dirty_block > 0) {
2758                         selected = dev->oldest_dirty_block;
2759                         dev->gc_dirtiest = selected;
2760                         dev->oldest_dirty_gc_count++;
2761                         bi = yaffs_get_block_info(dev, selected);
2762                         dev->gc_pages_in_use =
2763                             bi->pages_in_use - bi->soft_del_pages;
2764                 } else {
2765                         dev->gc_not_done = 0;
2766                 }
2767         }
2768
2769         if (selected) {
2770                 yaffs_trace(YAFFS_TRACE_GC,
2771                         "GC Selected block %d with %d free, prioritised:%d",
2772                         selected,
2773                         dev->param.chunks_per_block - dev->gc_pages_in_use,
2774                         prioritised);
2775
2776                 dev->n_gc_blocks++;
2777                 if (background)
2778                         dev->bg_gcs++;
2779
2780                 dev->gc_dirtiest = 0;
2781                 dev->gc_pages_in_use = 0;
2782                 dev->gc_not_done = 0;
2783                 if (dev->refresh_skip > 0)
2784                         dev->refresh_skip--;
2785         } else {
2786                 dev->gc_not_done++;
2787                 yaffs_trace(YAFFS_TRACE_GC,
2788                         "GC none: finder %d skip %d threshold %d dirtiest %d using %d oldest %d%s",
2789                         dev->gc_block_finder, dev->gc_not_done, threshold,
2790                         dev->gc_dirtiest, dev->gc_pages_in_use,
2791                         dev->oldest_dirty_block, background ? " bg" : "");
2792         }
2793
2794         return selected;
2795 }
2796
2797 /* New garbage collector
2798  * If we're very low on erased blocks then we do aggressive garbage collection
2799  * otherwise we do "leasurely" garbage collection.
2800  * Aggressive gc looks further (whole array) and will accept less dirty blocks.
2801  * Passive gc only inspects smaller areas and only accepts more dirty blocks.
2802  *
2803  * The idea is to help clear out space in a more spread-out manner.
2804  * Dunno if it really does anything useful.
2805  */
2806 static int yaffs_check_gc(struct yaffs_dev *dev, int background)
2807 {
2808         int aggressive = 0;
2809         int gc_ok = YAFFS_OK;
2810         int max_tries = 0;
2811         int min_erased;
2812         int erased_chunks;
2813         int checkpt_block_adjust;
2814
2815         if (dev->param.gc_control && (dev->param.gc_control(dev) & 1) == 0)
2816                 return YAFFS_OK;
2817
2818         if (dev->gc_disable)
2819                 /* Bail out so we don't get recursive gc */
2820                 return YAFFS_OK;
2821
2822         /* This loop should pass the first time.
2823          * Only loops here if the collection does not increase space.
2824          */
2825
2826         do {
2827                 max_tries++;
2828
2829                 checkpt_block_adjust = yaffs_calc_checkpt_blocks_required(dev);
2830
2831                 min_erased =
2832                     dev->param.n_reserved_blocks + checkpt_block_adjust + 1;
2833                 erased_chunks =
2834                     dev->n_erased_blocks * dev->param.chunks_per_block;
2835
2836                 /* If we need a block soon then do aggressive gc. */
2837                 if (dev->n_erased_blocks < min_erased)
2838                         aggressive = 1;
2839                 else {
2840                         if (!background
2841                             && erased_chunks > (dev->n_free_chunks / 4))
2842                                 break;
2843
2844                         if (dev->gc_skip > 20)
2845                                 dev->gc_skip = 20;
2846                         if (erased_chunks < dev->n_free_chunks / 2 ||
2847                             dev->gc_skip < 1 || background)
2848                                 aggressive = 0;
2849                         else {
2850                                 dev->gc_skip--;
2851                                 break;
2852                         }
2853                 }
2854
2855                 dev->gc_skip = 5;
2856
2857                 /* If we don't already have a block being gc'd then see if we
2858                  * should start another */
2859
2860                 if (dev->gc_block < 1 && !aggressive) {
2861                         dev->gc_block = yaffs2_find_refresh_block(dev);
2862                         dev->gc_chunk = 0;
2863                         dev->n_clean_ups = 0;
2864                 }
2865                 if (dev->gc_block < 1) {
2866                         dev->gc_block =
2867                             yaffs_find_gc_block(dev, aggressive, background);
2868                         dev->gc_chunk = 0;
2869                         dev->n_clean_ups = 0;
2870                 }
2871
2872                 if (dev->gc_block > 0) {
2873                         dev->all_gcs++;
2874                         if (!aggressive)
2875                                 dev->passive_gc_count++;
2876
2877                         yaffs_trace(YAFFS_TRACE_GC,
2878                                 "yaffs: GC n_erased_blocks %d aggressive %d",
2879                                 dev->n_erased_blocks, aggressive);
2880
2881                         gc_ok = yaffs_gc_block(dev, dev->gc_block, aggressive);
2882                 }
2883
2884                 if (dev->n_erased_blocks < (dev->param.n_reserved_blocks) &&
2885                     dev->gc_block > 0) {
2886                         yaffs_trace(YAFFS_TRACE_GC,
2887                                 "yaffs: GC !!!no reclaim!!! n_erased_blocks %d after try %d block %d",
2888                                 dev->n_erased_blocks, max_tries,
2889                                 dev->gc_block);
2890                 }
2891         } while ((dev->n_erased_blocks < dev->param.n_reserved_blocks) &&
2892                  (dev->gc_block > 0) && (max_tries < 2));
2893
2894         return aggressive ? gc_ok : YAFFS_OK;
2895 }
2896
2897 /*
2898  * yaffs_bg_gc()
2899  * Garbage collects. Intended to be called from a background thread.
2900  * Returns non-zero if at least half the free chunks are erased.
2901  */
2902 int yaffs_bg_gc(struct yaffs_dev *dev, unsigned urgency)
2903 {
2904         int erased_chunks = dev->n_erased_blocks * dev->param.chunks_per_block;
2905
2906         yaffs_trace(YAFFS_TRACE_BACKGROUND, "Background gc %u", urgency);
2907
2908         yaffs_check_gc(dev, 1);
2909         return erased_chunks > dev->n_free_chunks / 2;
2910 }
2911
2912 /*-------------------- Data file manipulation -----------------*/
2913
2914 static int yaffs_rd_data_obj(struct yaffs_obj *in, int inode_chunk, u8 * buffer)
2915 {
2916         int nand_chunk = yaffs_find_chunk_in_file(in, inode_chunk, NULL);
2917
2918         if (nand_chunk >= 0)
2919                 return yaffs_rd_chunk_tags_nand(in->my_dev, nand_chunk,
2920                                                 buffer, NULL);
2921         else {
2922                 yaffs_trace(YAFFS_TRACE_NANDACCESS,
2923                         "Chunk %d not found zero instead",
2924                         nand_chunk);
2925                 /* get sane (zero) data if you read a hole */
2926                 memset(buffer, 0, in->my_dev->data_bytes_per_chunk);
2927                 return 0;
2928         }
2929
2930 }
2931
2932 void yaffs_chunk_del(struct yaffs_dev *dev, int chunk_id, int mark_flash,
2933                      int lyn)
2934 {
2935         int block;
2936         int page;
2937         struct yaffs_ext_tags tags;
2938         struct yaffs_block_info *bi;
2939
2940         if (chunk_id <= 0)
2941                 return;
2942
2943         dev->n_deletions++;
2944         block = chunk_id / dev->param.chunks_per_block;
2945         page = chunk_id % dev->param.chunks_per_block;
2946
2947         if (!yaffs_check_chunk_bit(dev, block, page))
2948                 yaffs_trace(YAFFS_TRACE_VERIFY,
2949                         "Deleting invalid chunk %d", chunk_id);
2950
2951         bi = yaffs_get_block_info(dev, block);
2952
2953         yaffs2_update_oldest_dirty_seq(dev, block, bi);
2954
2955         yaffs_trace(YAFFS_TRACE_DELETION,
2956                 "line %d delete of chunk %d",
2957                 lyn, chunk_id);
2958
2959         if (!dev->param.is_yaffs2 && mark_flash &&
2960             bi->block_state != YAFFS_BLOCK_STATE_COLLECTING) {
2961
2962                 memset(&tags, 0, sizeof(tags));
2963                 tags.is_deleted = 1;
2964                 yaffs_wr_chunk_tags_nand(dev, chunk_id, NULL, &tags);
2965                 yaffs_handle_chunk_update(dev, chunk_id, &tags);
2966         } else {
2967                 dev->n_unmarked_deletions++;
2968         }
2969
2970         /* Pull out of the management area.
2971          * If the whole block became dirty, this will kick off an erasure.
2972          */
2973         if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING ||
2974             bi->block_state == YAFFS_BLOCK_STATE_FULL ||
2975             bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCAN ||
2976             bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
2977                 dev->n_free_chunks++;
2978                 yaffs_clear_chunk_bit(dev, block, page);
2979                 bi->pages_in_use--;
2980
2981                 if (bi->pages_in_use == 0 &&
2982                     !bi->has_shrink_hdr &&
2983                     bi->block_state != YAFFS_BLOCK_STATE_ALLOCATING &&
2984                     bi->block_state != YAFFS_BLOCK_STATE_NEEDS_SCAN) {
2985                         yaffs_block_became_dirty(dev, block);
2986                 }
2987         }
2988 }
2989
2990 static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
2991                              const u8 *buffer, int n_bytes, int use_reserve)
2992 {
2993         /* Find old chunk Need to do this to get serial number
2994          * Write new one and patch into tree.
2995          * Invalidate old tags.
2996          */
2997
2998         int prev_chunk_id;
2999         struct yaffs_ext_tags prev_tags;
3000         int new_chunk_id;
3001         struct yaffs_ext_tags new_tags;
3002         struct yaffs_dev *dev = in->my_dev;
3003
3004         yaffs_check_gc(dev, 0);
3005
3006         /* Get the previous chunk at this location in the file if it exists.
3007          * If it does not exist then put a zero into the tree. This creates
3008          * the tnode now, rather than later when it is harder to clean up.
3009          */
3010         prev_chunk_id = yaffs_find_chunk_in_file(in, inode_chunk, &prev_tags);
3011         if (prev_chunk_id < 1 &&
3012             !yaffs_put_chunk_in_file(in, inode_chunk, 0, 0))
3013                 return 0;
3014
3015         /* Set up new tags */
3016         memset(&new_tags, 0, sizeof(new_tags));
3017
3018         new_tags.chunk_id = inode_chunk;
3019         new_tags.obj_id = in->obj_id;
3020         new_tags.serial_number =
3021             (prev_chunk_id > 0) ? prev_tags.serial_number + 1 : 1;
3022         new_tags.n_bytes = n_bytes;
3023
3024         if (n_bytes < 1 || n_bytes > dev->param.total_bytes_per_chunk) {
3025                 yaffs_trace(YAFFS_TRACE_ERROR,
3026                   "Writing %d bytes to chunk!!!!!!!!!",
3027                    n_bytes);
3028                 BUG();
3029         }
3030
3031         new_chunk_id =
3032             yaffs_write_new_chunk(dev, buffer, &new_tags, use_reserve);
3033
3034         if (new_chunk_id > 0) {
3035                 yaffs_put_chunk_in_file(in, inode_chunk, new_chunk_id, 0);
3036
3037                 if (prev_chunk_id > 0)
3038                         yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
3039
3040                 yaffs_verify_file_sane(in);
3041         }
3042         return new_chunk_id;
3043
3044 }
3045
3046
3047
3048 static int yaffs_do_xattrib_mod(struct yaffs_obj *obj, int set,
3049                                 const YCHAR *name, const void *value, int size,
3050                                 int flags)
3051 {
3052         struct yaffs_xattr_mod xmod;
3053         int result;
3054
3055         xmod.set = set;
3056         xmod.name = name;
3057         xmod.data = value;
3058         xmod.size = size;
3059         xmod.flags = flags;
3060         xmod.result = -ENOSPC;
3061
3062         result = yaffs_update_oh(obj, NULL, 0, 0, 0, &xmod);
3063
3064         if (result > 0)
3065                 return xmod.result;
3066         else
3067                 return -ENOSPC;
3068 }
3069
3070 static int yaffs_apply_xattrib_mod(struct yaffs_obj *obj, char *buffer,
3071                                    struct yaffs_xattr_mod *xmod)
3072 {
3073         int retval = 0;
3074         int x_offs = sizeof(struct yaffs_obj_hdr);
3075         struct yaffs_dev *dev = obj->my_dev;
3076         int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
3077         char *x_buffer = buffer + x_offs;
3078
3079         if (xmod->set)
3080                 retval =
3081                     nval_set(x_buffer, x_size, xmod->name, xmod->data,
3082                              xmod->size, xmod->flags);
3083         else
3084                 retval = nval_del(x_buffer, x_size, xmod->name);
3085
3086         obj->has_xattr = nval_hasvalues(x_buffer, x_size);
3087         obj->xattr_known = 1;
3088         xmod->result = retval;
3089
3090         return retval;
3091 }
3092
3093 static int yaffs_do_xattrib_fetch(struct yaffs_obj *obj, const YCHAR *name,
3094                                   void *value, int size)
3095 {
3096         char *buffer = NULL;
3097         int result;
3098         struct yaffs_ext_tags tags;
3099         struct yaffs_dev *dev = obj->my_dev;
3100         int x_offs = sizeof(struct yaffs_obj_hdr);
3101         int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
3102         char *x_buffer;
3103         int retval = 0;
3104
3105         if (obj->hdr_chunk < 1)
3106                 return -ENODATA;
3107
3108         /* If we know that the object has no xattribs then don't do all the
3109          * reading and parsing.
3110          */
3111         if (obj->xattr_known && !obj->has_xattr) {
3112                 if (name)
3113                         return -ENODATA;
3114                 else
3115                         return 0;
3116         }
3117
3118         buffer = (char *)yaffs_get_temp_buffer(dev);
3119         if (!buffer)
3120                 return -ENOMEM;
3121
3122         result =
3123             yaffs_rd_chunk_tags_nand(dev, obj->hdr_chunk, (u8 *) buffer, &tags);
3124
3125         if (result != YAFFS_OK)
3126                 retval = -ENOENT;
3127         else {
3128                 x_buffer = buffer + x_offs;
3129
3130                 if (!obj->xattr_known) {
3131                         obj->has_xattr = nval_hasvalues(x_buffer, x_size);
3132                         obj->xattr_known = 1;
3133                 }
3134
3135                 if (name)
3136                         retval = nval_get(x_buffer, x_size, name, value, size);
3137                 else
3138                         retval = nval_list(x_buffer, x_size, value, size);
3139         }
3140         yaffs_release_temp_buffer(dev, (u8 *) buffer);
3141         return retval;
3142 }
3143
3144 int yaffs_set_xattrib(struct yaffs_obj *obj, const YCHAR * name,
3145                       const void *value, int size, int flags)
3146 {
3147         return yaffs_do_xattrib_mod(obj, 1, name, value, size, flags);
3148 }
3149
3150 int yaffs_remove_xattrib(struct yaffs_obj *obj, const YCHAR * name)
3151 {
3152         return yaffs_do_xattrib_mod(obj, 0, name, NULL, 0, 0);
3153 }
3154
3155 int yaffs_get_xattrib(struct yaffs_obj *obj, const YCHAR * name, void *value,
3156                       int size)
3157 {
3158         return yaffs_do_xattrib_fetch(obj, name, value, size);
3159 }
3160
3161 int yaffs_list_xattrib(struct yaffs_obj *obj, char *buffer, int size)
3162 {
3163         return yaffs_do_xattrib_fetch(obj, NULL, buffer, size);
3164 }
3165
3166 static void yaffs_check_obj_details_loaded(struct yaffs_obj *in)
3167 {
3168         u8 *buf;
3169         struct yaffs_obj_hdr *oh;
3170         struct yaffs_dev *dev;
3171         struct yaffs_ext_tags tags;
3172         int result;
3173         int alloc_failed = 0;
3174
3175         if (!in || !in->lazy_loaded || in->hdr_chunk < 1)
3176                 return;
3177
3178         dev = in->my_dev;
3179         in->lazy_loaded = 0;
3180         buf = yaffs_get_temp_buffer(dev);
3181
3182         result = yaffs_rd_chunk_tags_nand(dev, in->hdr_chunk, buf, &tags);
3183         oh = (struct yaffs_obj_hdr *)buf;
3184
3185         in->yst_mode = oh->yst_mode;
3186         yaffs_load_attribs(in, oh);
3187         yaffs_set_obj_name_from_oh(in, oh);
3188
3189         if (in->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
3190                 in->variant.symlink_variant.alias =
3191                     yaffs_clone_str(oh->alias);
3192                 if (!in->variant.symlink_variant.alias)
3193                         alloc_failed = 1;       /* Not returned */
3194         }
3195         yaffs_release_temp_buffer(dev, buf);
3196 }
3197
3198 static void yaffs_load_name_from_oh(struct yaffs_dev *dev, YCHAR *name,
3199                                     const YCHAR *oh_name, int buff_size)
3200 {
3201 #ifdef CONFIG_YAFFS_AUTO_UNICODE
3202         if (dev->param.auto_unicode) {
3203                 if (*oh_name) {
3204                         /* It is an ASCII name, do an ASCII to
3205                          * unicode conversion */
3206                         const char *ascii_oh_name = (const char *)oh_name;
3207                         int n = buff_size - 1;
3208                         while (n > 0 && *ascii_oh_name) {
3209                                 *name = *ascii_oh_name;
3210                                 name++;
3211                                 ascii_oh_name++;
3212                                 n--;
3213                         }
3214                 } else {
3215                         strncpy(name, oh_name + 1, buff_size - 1);
3216                 }
3217         } else {
3218 #else
3219         {
3220 #endif
3221                 strncpy(name, oh_name, buff_size - 1);
3222         }
3223 }
3224
3225 static void yaffs_load_oh_from_name(struct yaffs_dev *dev, YCHAR *oh_name,
3226                                     const YCHAR *name)
3227 {
3228 #ifdef CONFIG_YAFFS_AUTO_UNICODE
3229
3230         int is_ascii;
3231         YCHAR *w;
3232
3233         if (dev->param.auto_unicode) {
3234
3235                 is_ascii = 1;
3236                 w = name;
3237
3238                 /* Figure out if the name will fit in ascii character set */
3239                 while (is_ascii && *w) {
3240                         if ((*w) & 0xff00)
3241                                 is_ascii = 0;
3242                         w++;
3243                 }
3244
3245                 if (is_ascii) {
3246                         /* It is an ASCII name, so convert unicode to ascii */
3247                         char *ascii_oh_name = (char *)oh_name;
3248                         int n = YAFFS_MAX_NAME_LENGTH - 1;
3249                         while (n > 0 && *name) {
3250                                 *ascii_oh_name = *name;
3251                                 name++;
3252                                 ascii_oh_name++;
3253                                 n--;
3254                         }
3255                 } else {
3256                         /* Unicode name, so save starting at the second YCHAR */
3257                         *oh_name = 0;
3258                         strncpy(oh_name + 1, name, YAFFS_MAX_NAME_LENGTH - 2);
3259                 }
3260         } else {
3261 #else
3262         {
3263 #endif
3264                 strncpy(oh_name, name, YAFFS_MAX_NAME_LENGTH - 1);
3265         }
3266 }
3267
3268 /* UpdateObjectHeader updates the header on NAND for an object.
3269  * If name is not NULL, then that new name is used.
3270  */
3271 int yaffs_update_oh(struct yaffs_obj *in, const YCHAR *name, int force,
3272                     int is_shrink, int shadows, struct yaffs_xattr_mod *xmod)
3273 {
3274
3275         struct yaffs_block_info *bi;
3276         struct yaffs_dev *dev = in->my_dev;
3277         int prev_chunk_id;
3278         int ret_val = 0;
3279         int result = 0;
3280         int new_chunk_id;
3281         struct yaffs_ext_tags new_tags;
3282         struct yaffs_ext_tags old_tags;
3283         const YCHAR *alias = NULL;
3284         u8 *buffer = NULL;
3285         YCHAR old_name[YAFFS_MAX_NAME_LENGTH + 1];
3286         struct yaffs_obj_hdr *oh = NULL;
3287
3288         strcpy(old_name, _Y("silly old name"));
3289
3290         if (in->fake && in != dev->root_dir && !force && !xmod)
3291                 return ret_val;
3292
3293         yaffs_check_gc(dev, 0);
3294         yaffs_check_obj_details_loaded(in);
3295
3296         buffer = yaffs_get_temp_buffer(in->my_dev);
3297         oh = (struct yaffs_obj_hdr *)buffer;
3298
3299         prev_chunk_id = in->hdr_chunk;
3300
3301         if (prev_chunk_id > 0) {
3302                 result = yaffs_rd_chunk_tags_nand(dev, prev_chunk_id,
3303                                                   buffer, &old_tags);
3304
3305                 yaffs_verify_oh(in, oh, &old_tags, 0);
3306                 memcpy(old_name, oh->name, sizeof(oh->name));
3307                 memset(buffer, 0xff, sizeof(struct yaffs_obj_hdr));
3308         } else {
3309                 memset(buffer, 0xff, dev->data_bytes_per_chunk);
3310         }
3311
3312         oh->type = in->variant_type;
3313         oh->yst_mode = in->yst_mode;
3314         oh->shadows_obj = oh->inband_shadowed_obj_id = shadows;
3315
3316         yaffs_load_attribs_oh(oh, in);
3317
3318         if (in->parent)
3319                 oh->parent_obj_id = in->parent->obj_id;
3320         else
3321                 oh->parent_obj_id = 0;
3322
3323         if (name && *name) {
3324                 memset(oh->name, 0, sizeof(oh->name));
3325                 yaffs_load_oh_from_name(dev, oh->name, name);
3326         } else if (prev_chunk_id > 0) {
3327                 memcpy(oh->name, old_name, sizeof(oh->name));
3328         } else {
3329                 memset(oh->name, 0, sizeof(oh->name));
3330         }
3331
3332         oh->is_shrink = is_shrink;
3333
3334         switch (in->variant_type) {
3335         case YAFFS_OBJECT_TYPE_UNKNOWN:
3336                 /* Should not happen */
3337                 break;
3338         case YAFFS_OBJECT_TYPE_FILE:
3339                 oh->file_size =
3340                     (oh->parent_obj_id == YAFFS_OBJECTID_DELETED ||
3341                      oh->parent_obj_id == YAFFS_OBJECTID_UNLINKED) ?
3342                      0 : in->variant.file_variant.file_size;
3343                 break;
3344         case YAFFS_OBJECT_TYPE_HARDLINK:
3345                 oh->equiv_id = in->variant.hardlink_variant.equiv_id;
3346                 break;
3347         case YAFFS_OBJECT_TYPE_SPECIAL:
3348                 /* Do nothing */
3349                 break;
3350         case YAFFS_OBJECT_TYPE_DIRECTORY:
3351                 /* Do nothing */
3352                 break;
3353         case YAFFS_OBJECT_TYPE_SYMLINK:
3354                 alias = in->variant.symlink_variant.alias;
3355                 if (!alias)
3356                         alias = _Y("no alias");
3357                 strncpy(oh->alias, alias, YAFFS_MAX_ALIAS_LENGTH);
3358                 oh->alias[YAFFS_MAX_ALIAS_LENGTH] = 0;
3359                 break;
3360         }
3361
3362         /* process any xattrib modifications */
3363         if (xmod)
3364                 yaffs_apply_xattrib_mod(in, (char *)buffer, xmod);
3365
3366         /* Tags */
3367         memset(&new_tags, 0, sizeof(new_tags));
3368         in->serial++;
3369         new_tags.chunk_id = 0;
3370         new_tags.obj_id = in->obj_id;
3371         new_tags.serial_number = in->serial;
3372
3373         /* Add extra info for file header */
3374         new_tags.extra_available = 1;
3375         new_tags.extra_parent_id = oh->parent_obj_id;
3376         new_tags.extra_length = oh->file_size;
3377         new_tags.extra_is_shrink = oh->is_shrink;
3378         new_tags.extra_equiv_id = oh->equiv_id;
3379         new_tags.extra_shadows = (oh->shadows_obj > 0) ? 1 : 0;
3380         new_tags.extra_obj_type = in->variant_type;
3381         yaffs_verify_oh(in, oh, &new_tags, 1);
3382
3383         /* Create new chunk in NAND */
3384         new_chunk_id =
3385             yaffs_write_new_chunk(dev, buffer, &new_tags,
3386                                   (prev_chunk_id > 0) ? 1 : 0);
3387
3388         if (buffer)
3389                 yaffs_release_temp_buffer(dev, buffer);
3390
3391         if (new_chunk_id < 0)
3392                 return new_chunk_id;
3393
3394         in->hdr_chunk = new_chunk_id;
3395
3396         if (prev_chunk_id > 0)
3397                 yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
3398
3399         if (!yaffs_obj_cache_dirty(in))
3400                 in->dirty = 0;
3401
3402         /* If this was a shrink, then mark the block
3403          * that the chunk lives on */
3404         if (is_shrink) {
3405                 bi = yaffs_get_block_info(in->my_dev,
3406                                           new_chunk_id /
3407                                           in->my_dev->param.chunks_per_block);
3408                 bi->has_shrink_hdr = 1;
3409         }
3410
3411
3412         return new_chunk_id;
3413 }
3414
3415 /*--------------------- File read/write ------------------------
3416  * Read and write have very similar structures.
3417  * In general the read/write has three parts to it
3418  * An incomplete chunk to start with (if the read/write is not chunk-aligned)
3419  * Some complete chunks
3420  * An incomplete chunk to end off with
3421  *
3422  * Curve-balls: the first chunk might also be the last chunk.
3423  */
3424
3425 int yaffs_file_rd(struct yaffs_obj *in, u8 * buffer, loff_t offset, int n_bytes)
3426 {
3427         int chunk;
3428         u32 start;
3429         int n_copy;
3430         int n = n_bytes;
3431         int n_done = 0;
3432         struct yaffs_cache *cache;
3433         struct yaffs_dev *dev;
3434
3435         dev = in->my_dev;
3436
3437         while (n > 0) {
3438                 yaffs_addr_to_chunk(dev, offset, &chunk, &start);
3439                 chunk++;
3440
3441                 /* OK now check for the curveball where the start and end are in
3442                  * the same chunk.
3443                  */
3444                 if ((start + n) < dev->data_bytes_per_chunk)
3445                         n_copy = n;
3446                 else
3447                         n_copy = dev->data_bytes_per_chunk - start;
3448
3449                 cache = yaffs_find_chunk_cache(in, chunk);
3450
3451                 /* If the chunk is already in the cache or it is less than
3452                  * a whole chunk or we're using inband tags then use the cache
3453                  * (if there is caching) else bypass the cache.
3454                  */
3455                 if (cache || n_copy != dev->data_bytes_per_chunk ||
3456                     dev->param.inband_tags) {
3457                         if (dev->param.n_caches > 0) {
3458
3459                                 /* If we can't find the data in the cache,
3460                                  * then load it up. */
3461
3462                                 if (!cache) {
3463                                         cache =
3464                                             yaffs_grab_chunk_cache(in->my_dev);
3465                                         cache->object = in;
3466                                         cache->chunk_id = chunk;
3467                                         cache->dirty = 0;
3468                                         cache->locked = 0;
3469                                         yaffs_rd_data_obj(in, chunk,
3470                                                           cache->data);
3471                                         cache->n_bytes = 0;
3472                                 }
3473
3474                                 yaffs_use_cache(dev, cache, 0);
3475
3476                                 cache->locked = 1;
3477
3478                                 memcpy(buffer, &cache->data[start], n_copy);
3479
3480                                 cache->locked = 0;
3481                         } else {
3482                                 /* Read into the local buffer then copy.. */
3483
3484                                 u8 *local_buffer =
3485                                     yaffs_get_temp_buffer(dev);
3486                                 yaffs_rd_data_obj(in, chunk, local_buffer);
3487
3488                                 memcpy(buffer, &local_buffer[start], n_copy);
3489
3490                                 yaffs_release_temp_buffer(dev, local_buffer);
3491                         }
3492                 } else {
3493                         /* A full chunk. Read directly into the buffer. */
3494                         yaffs_rd_data_obj(in, chunk, buffer);
3495                 }
3496                 n -= n_copy;
3497                 offset += n_copy;
3498                 buffer += n_copy;
3499                 n_done += n_copy;
3500         }
3501         return n_done;
3502 }
3503
3504 int yaffs_do_file_wr(struct yaffs_obj *in, const u8 *buffer, loff_t offset,
3505                      int n_bytes, int write_trhrough)
3506 {
3507
3508         int chunk;
3509         u32 start;
3510         int n_copy;
3511         int n = n_bytes;
3512         int n_done = 0;
3513         int n_writeback;
3514         int start_write = offset;
3515         int chunk_written = 0;
3516         u32 n_bytes_read;
3517         u32 chunk_start;
3518         struct yaffs_dev *dev;
3519
3520         dev = in->my_dev;
3521
3522         while (n > 0 && chunk_written >= 0) {
3523                 yaffs_addr_to_chunk(dev, offset, &chunk, &start);
3524
3525                 if (chunk * dev->data_bytes_per_chunk + start != offset ||
3526                     start >= dev->data_bytes_per_chunk) {
3527                         yaffs_trace(YAFFS_TRACE_ERROR,
3528                                 "AddrToChunk of offset %d gives chunk %d start %d",
3529                                 (int)offset, chunk, start);
3530                 }
3531                 chunk++;        /* File pos to chunk in file offset */
3532
3533                 /* OK now check for the curveball where the start and end are in
3534                  * the same chunk.
3535                  */
3536
3537                 if ((start + n) < dev->data_bytes_per_chunk) {
3538                         n_copy = n;
3539
3540                         /* Now calculate how many bytes to write back....
3541                          * If we're overwriting and not writing to then end of
3542                          * file then we need to write back as much as was there
3543                          * before.
3544                          */
3545
3546                         chunk_start = ((chunk - 1) * dev->data_bytes_per_chunk);
3547
3548                         if (chunk_start > in->variant.file_variant.file_size)
3549                                 n_bytes_read = 0;       /* Past end of file */
3550                         else
3551                                 n_bytes_read =
3552                                     in->variant.file_variant.file_size -
3553                                     chunk_start;
3554
3555                         if (n_bytes_read > dev->data_bytes_per_chunk)
3556                                 n_bytes_read = dev->data_bytes_per_chunk;
3557
3558                         n_writeback =
3559                             (n_bytes_read >
3560                              (start + n)) ? n_bytes_read : (start + n);
3561
3562                         if (n_writeback < 0 ||
3563                             n_writeback > dev->data_bytes_per_chunk)
3564                                 BUG();
3565
3566                 } else {
3567                         n_copy = dev->data_bytes_per_chunk - start;
3568                         n_writeback = dev->data_bytes_per_chunk;
3569                 }
3570
3571                 if (n_copy != dev->data_bytes_per_chunk ||
3572                     dev->param.inband_tags) {
3573                         /* An incomplete start or end chunk (or maybe both
3574                          * start and end chunk), or we're using inband tags,
3575                          * so we want to use the cache buffers.
3576                          */
3577                         if (dev->param.n_caches > 0) {
3578                                 struct yaffs_cache *cache;
3579
3580                                 /* If we can't find the data in the cache, then
3581                                  * load the cache */
3582                                 cache = yaffs_find_chunk_cache(in, chunk);
3583
3584                                 if (!cache &&
3585                                     yaffs_check_alloc_available(dev, 1)) {
3586                                         cache = yaffs_grab_chunk_cache(dev);
3587                                         cache->object = in;
3588                                         cache->chunk_id = chunk;
3589                                         cache->dirty = 0;
3590                                         cache->locked = 0;
3591                                         yaffs_rd_data_obj(in, chunk,
3592                                                           cache->data);
3593                                 } else if (cache &&
3594                                            !cache->dirty &&
3595                                            !yaffs_check_alloc_available(dev,
3596                                                                         1)) {
3597                                         /* Drop the cache if it was a read cache
3598                                          * item and no space check has been made
3599                                          * for it.
3600                                          */
3601                                         cache = NULL;
3602                                 }
3603
3604                                 if (cache) {
3605                                         yaffs_use_cache(dev, cache, 1);
3606                                         cache->locked = 1;
3607
3608                                         memcpy(&cache->data[start], buffer,
3609                                                n_copy);
3610
3611                                         cache->locked = 0;
3612                                         cache->n_bytes = n_writeback;
3613
3614                                         if (write_trhrough) {
3615                                                 chunk_written =
3616                                                     yaffs_wr_data_obj
3617                                                     (cache->object,
3618                                                      cache->chunk_id,
3619                                                      cache->data,
3620                                                      cache->n_bytes, 1);
3621                                                 cache->dirty = 0;
3622                                         }
3623                                 } else {
3624                                         chunk_written = -1;     /* fail write */
3625                                 }
3626                         } else {
3627                                 /* An incomplete start or end chunk (or maybe
3628                                  * both start and end chunk). Read into the
3629                                  * local buffer then copy over and write back.
3630                                  */
3631
3632                                 u8 *local_buffer = yaffs_get_temp_buffer(dev);
3633
3634                                 yaffs_rd_data_obj(in, chunk, local_buffer);
3635                                 memcpy(&local_buffer[start], buffer, n_copy);
3636
3637                                 chunk_written =
3638                                     yaffs_wr_data_obj(in, chunk,
3639                                                       local_buffer,
3640                                                       n_writeback, 0);
3641
3642                                 yaffs_release_temp_buffer(dev, local_buffer);
3643                         }
3644                 } else {
3645                         /* A full chunk. Write directly from the buffer. */
3646
3647                         chunk_written =
3648                             yaffs_wr_data_obj(in, chunk, buffer,
3649                                               dev->data_bytes_per_chunk, 0);
3650
3651                         /* Since we've overwritten the cached data,
3652                          * we better invalidate it. */
3653                         yaffs_invalidate_chunk_cache(in, chunk);
3654                 }
3655
3656                 if (chunk_written >= 0) {
3657                         n -= n_copy;
3658                         offset += n_copy;
3659                         buffer += n_copy;
3660                         n_done += n_copy;
3661                 }
3662         }
3663
3664         /* Update file object */
3665
3666         if ((start_write + n_done) > in->variant.file_variant.file_size)
3667                 in->variant.file_variant.file_size = (start_write + n_done);
3668
3669         in->dirty = 1;
3670         return n_done;
3671 }
3672
3673 int yaffs_wr_file(struct yaffs_obj *in, const u8 *buffer, loff_t offset,
3674                   int n_bytes, int write_trhrough)
3675 {
3676         yaffs2_handle_hole(in, offset);
3677         return yaffs_do_file_wr(in, buffer, offset, n_bytes, write_trhrough);
3678 }
3679
3680 /* ---------------------- File resizing stuff ------------------ */
3681
3682 static void yaffs_prune_chunks(struct yaffs_obj *in, int new_size)
3683 {
3684
3685         struct yaffs_dev *dev = in->my_dev;
3686         int old_size = in->variant.file_variant.file_size;
3687         int i;
3688         int chunk_id;
3689         int last_del = 1 + (old_size - 1) / dev->data_bytes_per_chunk;
3690         int start_del = 1 + (new_size + dev->data_bytes_per_chunk - 1) /
3691             dev->data_bytes_per_chunk;
3692
3693
3694         /* Delete backwards so that we don't end up with holes if
3695          * power is lost part-way through the operation.
3696          */
3697         for (i = last_del; i >= start_del; i--) {
3698                 /* NB this could be optimised somewhat,
3699                  * eg. could retrieve the tags and write them without
3700                  * using yaffs_chunk_del
3701                  */
3702
3703                 chunk_id = yaffs_find_del_file_chunk(in, i, NULL);
3704
3705                 if (chunk_id < 1)
3706                         continue;
3707
3708                 if (chunk_id <
3709                     (dev->internal_start_block * dev->param.chunks_per_block) ||
3710                     chunk_id >=
3711                     ((dev->internal_end_block + 1) *
3712                       dev->param.chunks_per_block)) {
3713                         yaffs_trace(YAFFS_TRACE_ALWAYS,
3714                                 "Found daft chunk_id %d for %d",
3715                                 chunk_id, i);
3716                 } else {
3717                         in->n_data_chunks--;
3718                         yaffs_chunk_del(dev, chunk_id, 1, __LINE__);
3719                 }
3720         }
3721 }
3722
3723 void yaffs_resize_file_down(struct yaffs_obj *obj, loff_t new_size)
3724 {
3725         int new_full;
3726         u32 new_partial;
3727         struct yaffs_dev *dev = obj->my_dev;
3728
3729         yaffs_addr_to_chunk(dev, new_size, &new_full, &new_partial);
3730
3731         yaffs_prune_chunks(obj, new_size);
3732
3733         if (new_partial != 0) {
3734                 int last_chunk = 1 + new_full;
3735                 u8 *local_buffer = yaffs_get_temp_buffer(dev);
3736
3737                 /* Rewrite the last chunk with its new size and zero pad */
3738                 yaffs_rd_data_obj(obj, last_chunk, local_buffer);
3739                 memset(local_buffer + new_partial, 0,
3740                        dev->data_bytes_per_chunk - new_partial);
3741
3742                 yaffs_wr_data_obj(obj, last_chunk, local_buffer,
3743                                   new_partial, 1);
3744
3745                 yaffs_release_temp_buffer(dev, local_buffer);
3746         }
3747
3748         obj->variant.file_variant.file_size = new_size;
3749
3750         yaffs_prune_tree(dev, &obj->variant.file_variant);
3751 }
3752
3753 int yaffs_resize_file(struct yaffs_obj *in, loff_t new_size)
3754 {
3755         struct yaffs_dev *dev = in->my_dev;
3756         int old_size = in->variant.file_variant.file_size;
3757
3758         yaffs_flush_file_cache(in);
3759         yaffs_invalidate_whole_cache(in);
3760
3761         yaffs_check_gc(dev, 0);
3762
3763         if (in->variant_type != YAFFS_OBJECT_TYPE_FILE)
3764                 return YAFFS_FAIL;
3765
3766         if (new_size == old_size)
3767                 return YAFFS_OK;
3768
3769         if (new_size > old_size) {
3770                 yaffs2_handle_hole(in, new_size);
3771                 in->variant.file_variant.file_size = new_size;
3772         } else {
3773                 /* new_size < old_size */
3774                 yaffs_resize_file_down(in, new_size);
3775         }
3776
3777         /* Write a new object header to reflect the resize.
3778          * show we've shrunk the file, if need be
3779          * Do this only if the file is not in the deleted directories
3780          * and is not shadowed.
3781          */
3782         if (in->parent &&
3783             !in->is_shadowed &&
3784             in->parent->obj_id != YAFFS_OBJECTID_UNLINKED &&
3785             in->parent->obj_id != YAFFS_OBJECTID_DELETED)
3786                 yaffs_update_oh(in, NULL, 0, 0, 0, NULL);
3787
3788         return YAFFS_OK;
3789 }
3790
3791 int yaffs_flush_file(struct yaffs_obj *in, int update_time, int data_sync)
3792 {
3793         if (!in->dirty)
3794                 return YAFFS_OK;
3795
3796         yaffs_flush_file_cache(in);
3797
3798         if (data_sync)
3799                 return YAFFS_OK;
3800
3801         if (update_time)
3802                 yaffs_load_current_time(in, 0, 0);
3803
3804         return (yaffs_update_oh(in, NULL, 0, 0, 0, NULL) >= 0) ?
3805                                 YAFFS_OK : YAFFS_FAIL;
3806 }
3807
3808
3809 /* yaffs_del_file deletes the whole file data
3810  * and the inode associated with the file.
3811  * It does not delete the links associated with the file.
3812  */
3813 static int yaffs_unlink_file_if_needed(struct yaffs_obj *in)
3814 {
3815         int ret_val;
3816         int del_now = 0;
3817         struct yaffs_dev *dev = in->my_dev;
3818
3819         if (!in->my_inode)
3820                 del_now = 1;
3821
3822         if (del_now) {
3823                 ret_val =
3824                     yaffs_change_obj_name(in, in->my_dev->del_dir,
3825                                           _Y("deleted"), 0, 0);
3826                 yaffs_trace(YAFFS_TRACE_TRACING,
3827                         "yaffs: immediate deletion of file %d",
3828                         in->obj_id);
3829                 in->deleted = 1;
3830                 in->my_dev->n_deleted_files++;
3831                 if (dev->param.disable_soft_del || dev->param.is_yaffs2)
3832                         yaffs_resize_file(in, 0);
3833                 yaffs_soft_del_file(in);
3834         } else {
3835                 ret_val =
3836                     yaffs_change_obj_name(in, in->my_dev->unlinked_dir,
3837                                           _Y("unlinked"), 0, 0);
3838         }
3839         return ret_val;
3840 }
3841
3842 int yaffs_del_file(struct yaffs_obj *in)
3843 {
3844         int ret_val = YAFFS_OK;
3845         int deleted;    /* Need to cache value on stack if in is freed */
3846         struct yaffs_dev *dev = in->my_dev;
3847
3848         if (dev->param.disable_soft_del || dev->param.is_yaffs2)
3849                 yaffs_resize_file(in, 0);
3850
3851         if (in->n_data_chunks > 0) {
3852                 /* Use soft deletion if there is data in the file.
3853                  * That won't be the case if it has been resized to zero.
3854                  */
3855                 if (!in->unlinked)
3856                         ret_val = yaffs_unlink_file_if_needed(in);
3857
3858                 deleted = in->deleted;
3859
3860                 if (ret_val == YAFFS_OK && in->unlinked && !in->deleted) {
3861                         in->deleted = 1;
3862                         deleted = 1;
3863                         in->my_dev->n_deleted_files++;
3864                         yaffs_soft_del_file(in);
3865                 }
3866                 return deleted ? YAFFS_OK : YAFFS_FAIL;
3867         } else {
3868                 /* The file has no data chunks so we toss it immediately */
3869                 yaffs_free_tnode(in->my_dev, in->variant.file_variant.top);
3870                 in->variant.file_variant.top = NULL;
3871                 yaffs_generic_obj_del(in);
3872
3873                 return YAFFS_OK;
3874         }
3875 }
3876
3877 int yaffs_is_non_empty_dir(struct yaffs_obj *obj)
3878 {
3879         return (obj &&
3880                 obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY) &&
3881                 !(list_empty(&obj->variant.dir_variant.children));
3882 }
3883
3884 static int yaffs_del_dir(struct yaffs_obj *obj)
3885 {
3886         /* First check that the directory is empty. */
3887         if (yaffs_is_non_empty_dir(obj))
3888                 return YAFFS_FAIL;
3889
3890         return yaffs_generic_obj_del(obj);
3891 }
3892
3893 static int yaffs_del_symlink(struct yaffs_obj *in)
3894 {
3895         kfree(in->variant.symlink_variant.alias);
3896         in->variant.symlink_variant.alias = NULL;
3897
3898         return yaffs_generic_obj_del(in);
3899 }
3900
3901 static int yaffs_del_link(struct yaffs_obj *in)
3902 {
3903         /* remove this hardlink from the list associated with the equivalent
3904          * object
3905          */
3906         list_del_init(&in->hard_links);
3907         return yaffs_generic_obj_del(in);
3908 }
3909
3910 int yaffs_del_obj(struct yaffs_obj *obj)
3911 {
3912         int ret_val = -1;
3913
3914         switch (obj->variant_type) {
3915         case YAFFS_OBJECT_TYPE_FILE:
3916                 ret_val = yaffs_del_file(obj);
3917                 break;
3918         case YAFFS_OBJECT_TYPE_DIRECTORY:
3919                 if (!list_empty(&obj->variant.dir_variant.dirty)) {
3920                         yaffs_trace(YAFFS_TRACE_BACKGROUND,
3921                                 "Remove object %d from dirty directories",
3922                                 obj->obj_id);
3923                         list_del_init(&obj->variant.dir_variant.dirty);
3924                 }
3925                 return yaffs_del_dir(obj);
3926                 break;
3927         case YAFFS_OBJECT_TYPE_SYMLINK:
3928                 ret_val = yaffs_del_symlink(obj);
3929                 break;
3930         case YAFFS_OBJECT_TYPE_HARDLINK:
3931                 ret_val = yaffs_del_link(obj);
3932                 break;
3933         case YAFFS_OBJECT_TYPE_SPECIAL:
3934                 ret_val = yaffs_generic_obj_del(obj);
3935                 break;
3936         case YAFFS_OBJECT_TYPE_UNKNOWN:
3937                 ret_val = 0;
3938                 break;          /* should not happen. */
3939         }
3940         return ret_val;
3941 }
3942
3943 static int yaffs_unlink_worker(struct yaffs_obj *obj)
3944 {
3945         int del_now = 0;
3946
3947         if (!obj)
3948                 return YAFFS_FAIL;
3949
3950         if (!obj->my_inode)
3951                 del_now = 1;
3952
3953         yaffs_update_parent(obj->parent);
3954
3955         if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
3956                 return yaffs_del_link(obj);
3957         } else if (!list_empty(&obj->hard_links)) {
3958                 /* Curve ball: We're unlinking an object that has a hardlink.
3959                  *
3960                  * This problem arises because we are not strictly following
3961                  * The Linux link/inode model.
3962                  *
3963                  * We can't really delete the object.
3964                  * Instead, we do the following:
3965                  * - Select a hardlink.
3966                  * - Unhook it from the hard links
3967                  * - Move it from its parent directory so that the rename works.
3968                  * - Rename the object to the hardlink's name.
3969                  * - Delete the hardlink
3970                  */
3971
3972                 struct yaffs_obj *hl;
3973                 struct yaffs_obj *parent;
3974                 int ret_val;
3975                 YCHAR name[YAFFS_MAX_NAME_LENGTH + 1];
3976
3977                 hl = list_entry(obj->hard_links.next, struct yaffs_obj,
3978                                 hard_links);
3979
3980                 yaffs_get_obj_name(hl, name, YAFFS_MAX_NAME_LENGTH + 1);
3981                 parent = hl->parent;
3982
3983                 list_del_init(&hl->hard_links);
3984
3985                 yaffs_add_obj_to_dir(obj->my_dev->unlinked_dir, hl);
3986
3987                 ret_val = yaffs_change_obj_name(obj, parent, name, 0, 0);
3988
3989                 if (ret_val == YAFFS_OK)
3990                         ret_val = yaffs_generic_obj_del(hl);
3991
3992                 return ret_val;
3993
3994         } else if (del_now) {
3995                 switch (obj->variant_type) {
3996                 case YAFFS_OBJECT_TYPE_FILE:
3997                         return yaffs_del_file(obj);
3998                         break;
3999                 case YAFFS_OBJECT_TYPE_DIRECTORY:
4000                         list_del_init(&obj->variant.dir_variant.dirty);
4001                         return yaffs_del_dir(obj);
4002                         break;
4003                 case YAFFS_OBJECT_TYPE_SYMLINK:
4004                         return yaffs_del_symlink(obj);
4005                         break;
4006                 case YAFFS_OBJECT_TYPE_SPECIAL:
4007                         return yaffs_generic_obj_del(obj);
4008                         break;
4009                 case YAFFS_OBJECT_TYPE_HARDLINK:
4010                 case YAFFS_OBJECT_TYPE_UNKNOWN:
4011                 default:
4012                         return YAFFS_FAIL;
4013                 }
4014         } else if (yaffs_is_non_empty_dir(obj)) {
4015                 return YAFFS_FAIL;
4016         } else {
4017                 return yaffs_change_obj_name(obj, obj->my_dev->unlinked_dir,
4018                                                 _Y("unlinked"), 0, 0);
4019         }
4020 }
4021
4022 static int yaffs_unlink_obj(struct yaffs_obj *obj)
4023 {
4024         if (obj && obj->unlink_allowed)
4025                 return yaffs_unlink_worker(obj);
4026
4027         return YAFFS_FAIL;
4028 }
4029
4030 int yaffs_unlinker(struct yaffs_obj *dir, const YCHAR *name)
4031 {
4032         struct yaffs_obj *obj;
4033
4034         obj = yaffs_find_by_name(dir, name);
4035         return yaffs_unlink_obj(obj);
4036 }
4037
4038 /* Note:
4039  * If old_name is NULL then we take old_dir as the object to be renamed.
4040  */
4041 int yaffs_rename_obj(struct yaffs_obj *old_dir, const YCHAR *old_name,
4042                      struct yaffs_obj *new_dir, const YCHAR *new_name)
4043 {
4044         struct yaffs_obj *obj = NULL;
4045         struct yaffs_obj *existing_target = NULL;
4046         int force = 0;
4047         int result;
4048         struct yaffs_dev *dev;
4049
4050         if (!old_dir || old_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4051                 BUG();
4052                 return YAFFS_FAIL;
4053         }
4054         if (!new_dir || new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4055                 BUG();
4056                 return YAFFS_FAIL;
4057         }
4058
4059         dev = old_dir->my_dev;
4060
4061 #ifdef CONFIG_YAFFS_CASE_INSENSITIVE
4062         /* Special case for case insemsitive systems.
4063          * While look-up is case insensitive, the name isn't.
4064          * Therefore we might want to change x.txt to X.txt
4065          */
4066         if (old_dir == new_dir &&
4067                 old_name && new_name &&
4068                 strcmp(old_name, new_name) == 0)
4069                 force = 1;
4070 #endif
4071
4072         if (strnlen(new_name, YAFFS_MAX_NAME_LENGTH + 1) >
4073             YAFFS_MAX_NAME_LENGTH)
4074                 /* ENAMETOOLONG */
4075                 return YAFFS_FAIL;
4076
4077         if (old_name)
4078                 obj = yaffs_find_by_name(old_dir, old_name);
4079         else{
4080                 obj = old_dir;
4081                 old_dir = obj->parent;
4082         }
4083
4084         if (obj && obj->rename_allowed) {
4085                 /* Now handle an existing target, if there is one */
4086                 existing_target = yaffs_find_by_name(new_dir, new_name);
4087                 if (yaffs_is_non_empty_dir(existing_target)) {
4088                         return YAFFS_FAIL;      /* ENOTEMPTY */
4089                 } else if (existing_target && existing_target != obj) {
4090                         /* Nuke the target first, using shadowing,
4091                          * but only if it isn't the same object.
4092                          *
4093                          * Note we must disable gc here otherwise it can mess
4094                          * up the shadowing.
4095                          *
4096                          */
4097                         dev->gc_disable = 1;
4098                         yaffs_change_obj_name(obj, new_dir, new_name, force,
4099                                               existing_target->obj_id);
4100                         existing_target->is_shadowed = 1;
4101                         yaffs_unlink_obj(existing_target);
4102                         dev->gc_disable = 0;
4103                 }
4104
4105                 result = yaffs_change_obj_name(obj, new_dir, new_name, 1, 0);
4106
4107                 yaffs_update_parent(old_dir);
4108                 if (new_dir != old_dir)
4109                         yaffs_update_parent(new_dir);
4110
4111                 return result;
4112         }
4113         return YAFFS_FAIL;
4114 }
4115
4116 /*----------------------- Initialisation Scanning ---------------------- */
4117
4118 void yaffs_handle_shadowed_obj(struct yaffs_dev *dev, int obj_id,
4119                                int backward_scanning)
4120 {
4121         struct yaffs_obj *obj;
4122
4123         if (backward_scanning) {
4124                 /* Handle YAFFS2 case (backward scanning)
4125                  * If the shadowed object exists then ignore.
4126                  */
4127                 obj = yaffs_find_by_number(dev, obj_id);
4128                 if (obj)
4129                         return;
4130         }
4131
4132         /* Let's create it (if it does not exist) assuming it is a file so that
4133          * it can do shrinking etc.
4134          * We put it in unlinked dir to be cleaned up after the scanning
4135          */
4136         obj =
4137             yaffs_find_or_create_by_number(dev, obj_id, YAFFS_OBJECT_TYPE_FILE);
4138         if (!obj)
4139                 return;
4140         obj->is_shadowed = 1;
4141         yaffs_add_obj_to_dir(dev->unlinked_dir, obj);
4142         obj->variant.file_variant.shrink_size = 0;
4143         obj->valid = 1;         /* So that we don't read any other info. */
4144 }
4145
4146 void yaffs_link_fixup(struct yaffs_dev *dev, struct list_head *hard_list)
4147 {
4148         struct list_head *lh;
4149         struct list_head *save;
4150         struct yaffs_obj *hl;
4151         struct yaffs_obj *in;
4152
4153         list_for_each_safe(lh, save, hard_list) {
4154                 hl = list_entry(lh, struct yaffs_obj, hard_links);
4155                 in = yaffs_find_by_number(dev,
4156                                         hl->variant.hardlink_variant.equiv_id);
4157
4158                 if (in) {
4159                         /* Add the hardlink pointers */
4160                         hl->variant.hardlink_variant.equiv_obj = in;
4161                         list_add(&hl->hard_links, &in->hard_links);
4162                 } else {
4163                         /* Todo Need to report/handle this better.
4164                          * Got a problem... hardlink to a non-existant object
4165                          */
4166                         hl->variant.hardlink_variant.equiv_obj = NULL;
4167                         INIT_LIST_HEAD(&hl->hard_links);
4168                 }
4169         }
4170 }
4171
4172 static void yaffs_strip_deleted_objs(struct yaffs_dev *dev)
4173 {
4174         /*
4175          *  Sort out state of unlinked and deleted objects after scanning.
4176          */
4177         struct list_head *i;
4178         struct list_head *n;
4179         struct yaffs_obj *l;
4180
4181         if (dev->read_only)
4182                 return;
4183
4184         /* Soft delete all the unlinked files */
4185         list_for_each_safe(i, n,
4186                            &dev->unlinked_dir->variant.dir_variant.children) {
4187                 l = list_entry(i, struct yaffs_obj, siblings);
4188                 yaffs_del_obj(l);
4189         }
4190
4191         list_for_each_safe(i, n, &dev->del_dir->variant.dir_variant.children) {
4192                 l = list_entry(i, struct yaffs_obj, siblings);
4193                 yaffs_del_obj(l);
4194         }
4195 }
4196
4197 /*
4198  * This code iterates through all the objects making sure that they are rooted.
4199  * Any unrooted objects are re-rooted in lost+found.
4200  * An object needs to be in one of:
4201  * - Directly under deleted, unlinked
4202  * - Directly or indirectly under root.
4203  *
4204  * Note:
4205  *  This code assumes that we don't ever change the current relationships
4206  *  between directories:
4207  *   root_dir->parent == unlinked_dir->parent == del_dir->parent == NULL
4208  *   lost-n-found->parent == root_dir
4209  *
4210  * This fixes the problem where directories might have inadvertently been
4211  * deleted leaving the object "hanging" without being rooted in the
4212  * directory tree.
4213  */
4214
4215 static int yaffs_has_null_parent(struct yaffs_dev *dev, struct yaffs_obj *obj)
4216 {
4217         return (obj == dev->del_dir ||
4218                 obj == dev->unlinked_dir || obj == dev->root_dir);
4219 }
4220
4221 static void yaffs_fix_hanging_objs(struct yaffs_dev *dev)
4222 {
4223         struct yaffs_obj *obj;
4224         struct yaffs_obj *parent;
4225         int i;
4226         struct list_head *lh;
4227         struct list_head *n;
4228         int depth_limit;
4229         int hanging;
4230
4231         if (dev->read_only)
4232                 return;
4233
4234         /* Iterate through the objects in each hash entry,
4235          * looking at each object.
4236          * Make sure it is rooted.
4237          */
4238
4239         for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
4240                 list_for_each_safe(lh, n, &dev->obj_bucket[i].list) {
4241                         obj = list_entry(lh, struct yaffs_obj, hash_link);
4242                         parent = obj->parent;
4243
4244                         if (yaffs_has_null_parent(dev, obj)) {
4245                                 /* These directories are not hanging */
4246                                 hanging = 0;
4247                         } else if (!parent ||
4248                                    parent->variant_type !=
4249                                    YAFFS_OBJECT_TYPE_DIRECTORY) {
4250                                 hanging = 1;
4251                         } else if (yaffs_has_null_parent(dev, parent)) {
4252                                 hanging = 0;
4253                         } else {
4254                                 /*
4255                                  * Need to follow the parent chain to
4256                                  * see if it is hanging.
4257                                  */
4258                                 hanging = 0;
4259                                 depth_limit = 100;
4260
4261                                 while (parent != dev->root_dir &&
4262                                        parent->parent &&
4263                                        parent->parent->variant_type ==
4264                                        YAFFS_OBJECT_TYPE_DIRECTORY &&
4265                                        depth_limit > 0) {
4266                                         parent = parent->parent;
4267                                         depth_limit--;
4268                                 }
4269                                 if (parent != dev->root_dir)
4270                                         hanging = 1;
4271                         }
4272                         if (hanging) {
4273                                 yaffs_trace(YAFFS_TRACE_SCAN,
4274                                         "Hanging object %d moved to lost and found",
4275                                         obj->obj_id);
4276                                 yaffs_add_obj_to_dir(dev->lost_n_found, obj);
4277                         }
4278                 }
4279         }
4280 }
4281
4282 /*
4283  * Delete directory contents for cleaning up lost and found.
4284  */
4285 static void yaffs_del_dir_contents(struct yaffs_obj *dir)
4286 {
4287         struct yaffs_obj *obj;
4288         struct list_head *lh;
4289         struct list_head *n;
4290
4291         if (dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
4292                 BUG();
4293
4294         list_for_each_safe(lh, n, &dir->variant.dir_variant.children) {
4295                 obj = list_entry(lh, struct yaffs_obj, siblings);
4296                 if (obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY)
4297                         yaffs_del_dir_contents(obj);
4298                 yaffs_trace(YAFFS_TRACE_SCAN,
4299                         "Deleting lost_found object %d",
4300                         obj->obj_id);
4301                 yaffs_unlink_obj(obj);
4302         }
4303 }
4304
4305 static void yaffs_empty_l_n_f(struct yaffs_dev *dev)
4306 {
4307         yaffs_del_dir_contents(dev->lost_n_found);
4308 }
4309
4310
4311 struct yaffs_obj *yaffs_find_by_name(struct yaffs_obj *directory,
4312                                      const YCHAR *name)
4313 {
4314         int sum;
4315         struct list_head *i;
4316         YCHAR buffer[YAFFS_MAX_NAME_LENGTH + 1];
4317         struct yaffs_obj *l;
4318
4319         if (!name)
4320                 return NULL;
4321
4322         if (!directory) {
4323                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4324                         "tragedy: yaffs_find_by_name: null pointer directory"
4325                         );
4326                 BUG();
4327                 return NULL;
4328         }
4329         if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4330                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4331                         "tragedy: yaffs_find_by_name: non-directory"
4332                         );
4333                 BUG();
4334         }
4335
4336         sum = yaffs_calc_name_sum(name);
4337
4338         list_for_each(i, &directory->variant.dir_variant.children) {
4339                 l = list_entry(i, struct yaffs_obj, siblings);
4340
4341                 if (l->parent != directory)
4342                         BUG();
4343
4344                 yaffs_check_obj_details_loaded(l);
4345
4346                 /* Special case for lost-n-found */
4347                 if (l->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
4348                         if (!strcmp(name, YAFFS_LOSTNFOUND_NAME))
4349                                 return l;
4350                 } else if (l->sum == sum || l->hdr_chunk <= 0) {
4351                         /* LostnFound chunk called Objxxx
4352                          * Do a real check
4353                          */
4354                         yaffs_get_obj_name(l, buffer,
4355                                 YAFFS_MAX_NAME_LENGTH + 1);
4356                         if (strncmp(name, buffer, YAFFS_MAX_NAME_LENGTH) == 0)
4357                                 return l;
4358                 }
4359         }
4360         return NULL;
4361 }
4362
4363 /* GetEquivalentObject dereferences any hard links to get to the
4364  * actual object.
4365  */
4366
4367 struct yaffs_obj *yaffs_get_equivalent_obj(struct yaffs_obj *obj)
4368 {
4369         if (obj && obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
4370                 obj = obj->variant.hardlink_variant.equiv_obj;
4371                 yaffs_check_obj_details_loaded(obj);
4372         }
4373         return obj;
4374 }
4375
4376 /*
4377  *  A note or two on object names.
4378  *  * If the object name is missing, we then make one up in the form objnnn
4379  *
4380  *  * ASCII names are stored in the object header's name field from byte zero
4381  *  * Unicode names are historically stored starting from byte zero.
4382  *
4383  * Then there are automatic Unicode names...
4384  * The purpose of these is to save names in a way that can be read as
4385  * ASCII or Unicode names as appropriate, thus allowing a Unicode and ASCII
4386  * system to share files.
4387  *
4388  * These automatic unicode are stored slightly differently...
4389  *  - If the name can fit in the ASCII character space then they are saved as
4390  *    ascii names as per above.
4391  *  - If the name needs Unicode then the name is saved in Unicode
4392  *    starting at oh->name[1].
4393
4394  */
4395 static void yaffs_fix_null_name(struct yaffs_obj *obj, YCHAR *name,
4396                                 int buffer_size)
4397 {
4398         /* Create an object name if we could not find one. */
4399         if (strnlen(name, YAFFS_MAX_NAME_LENGTH) == 0) {
4400                 YCHAR local_name[20];
4401                 YCHAR num_string[20];
4402                 YCHAR *x = &num_string[19];
4403                 unsigned v = obj->obj_id;
4404                 num_string[19] = 0;
4405                 while (v > 0) {
4406                         x--;
4407                         *x = '0' + (v % 10);
4408                         v /= 10;
4409                 }
4410                 /* make up a name */
4411                 strcpy(local_name, YAFFS_LOSTNFOUND_PREFIX);
4412                 strcat(local_name, x);
4413                 strncpy(name, local_name, buffer_size - 1);
4414         }
4415 }
4416
4417 int yaffs_get_obj_name(struct yaffs_obj *obj, YCHAR *name, int buffer_size)
4418 {
4419         memset(name, 0, buffer_size * sizeof(YCHAR));
4420         yaffs_check_obj_details_loaded(obj);
4421         if (obj->obj_id == YAFFS_OBJECTID_LOSTNFOUND)
4422                 strncpy(name, YAFFS_LOSTNFOUND_NAME, buffer_size - 1);
4423 #ifndef CONFIG_YAFFS_NO_SHORT_NAMES
4424         else if (obj->short_name[0])
4425                 strcpy(name, obj->short_name);
4426 #endif
4427         else if (obj->hdr_chunk > 0) {
4428                 int result;
4429                 u8 *buffer = yaffs_get_temp_buffer(obj->my_dev);
4430
4431                 struct yaffs_obj_hdr *oh = (struct yaffs_obj_hdr *)buffer;
4432
4433                 memset(buffer, 0, obj->my_dev->data_bytes_per_chunk);
4434
4435                 if (obj->hdr_chunk > 0) {
4436                         result = yaffs_rd_chunk_tags_nand(obj->my_dev,
4437                                                           obj->hdr_chunk,
4438                                                           buffer, NULL);
4439                 }
4440                 yaffs_load_name_from_oh(obj->my_dev, name, oh->name,
4441                                         buffer_size);
4442
4443                 yaffs_release_temp_buffer(obj->my_dev, buffer);
4444         }
4445
4446         yaffs_fix_null_name(obj, name, buffer_size);
4447
4448         return strnlen(name, YAFFS_MAX_NAME_LENGTH);
4449 }
4450
4451 int yaffs_get_obj_length(struct yaffs_obj *obj)
4452 {
4453         /* Dereference any hard linking */
4454         obj = yaffs_get_equivalent_obj(obj);
4455
4456         if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
4457                 return obj->variant.file_variant.file_size;
4458         if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
4459                 if (!obj->variant.symlink_variant.alias)
4460                         return 0;
4461                 return strnlen(obj->variant.symlink_variant.alias,
4462                                      YAFFS_MAX_ALIAS_LENGTH);
4463         } else {
4464                 /* Only a directory should drop through to here */
4465                 return obj->my_dev->data_bytes_per_chunk;
4466         }
4467 }
4468
4469 int yaffs_get_obj_link_count(struct yaffs_obj *obj)
4470 {
4471         int count = 0;
4472         struct list_head *i;
4473
4474         if (!obj->unlinked)
4475                 count++;        /* the object itself */
4476
4477         list_for_each(i, &obj->hard_links)
4478             count++;            /* add the hard links; */
4479
4480         return count;
4481 }
4482
4483 int yaffs_get_obj_inode(struct yaffs_obj *obj)
4484 {
4485         obj = yaffs_get_equivalent_obj(obj);
4486
4487         return obj->obj_id;
4488 }
4489
4490 unsigned yaffs_get_obj_type(struct yaffs_obj *obj)
4491 {
4492         obj = yaffs_get_equivalent_obj(obj);
4493
4494         switch (obj->variant_type) {
4495         case YAFFS_OBJECT_TYPE_FILE:
4496                 return DT_REG;
4497                 break;
4498         case YAFFS_OBJECT_TYPE_DIRECTORY:
4499                 return DT_DIR;
4500                 break;
4501         case YAFFS_OBJECT_TYPE_SYMLINK:
4502                 return DT_LNK;
4503                 break;
4504         case YAFFS_OBJECT_TYPE_HARDLINK:
4505                 return DT_REG;
4506                 break;
4507         case YAFFS_OBJECT_TYPE_SPECIAL:
4508                 if (S_ISFIFO(obj->yst_mode))
4509                         return DT_FIFO;
4510                 if (S_ISCHR(obj->yst_mode))
4511                         return DT_CHR;
4512                 if (S_ISBLK(obj->yst_mode))
4513                         return DT_BLK;
4514                 if (S_ISSOCK(obj->yst_mode))
4515                         return DT_SOCK;
4516                 return DT_REG;
4517                 break;
4518         default:
4519                 return DT_REG;
4520                 break;
4521         }
4522 }
4523
4524 YCHAR *yaffs_get_symlink_alias(struct yaffs_obj *obj)
4525 {
4526         obj = yaffs_get_equivalent_obj(obj);
4527         if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK)
4528                 return yaffs_clone_str(obj->variant.symlink_variant.alias);
4529         else
4530                 return yaffs_clone_str(_Y(""));
4531 }
4532
4533 /*--------------------------- Initialisation code -------------------------- */
4534
4535 static int yaffs_check_dev_fns(const struct yaffs_dev *dev)
4536 {
4537         /* Common functions, gotta have */
4538         if (!dev->param.erase_fn || !dev->param.initialise_flash_fn)
4539                 return 0;
4540
4541 #ifdef CONFIG_YAFFS_YAFFS2
4542
4543         /* Can use the "with tags" style interface for yaffs1 or yaffs2 */
4544         if (dev->param.write_chunk_tags_fn &&
4545             dev->param.read_chunk_tags_fn &&
4546             !dev->param.write_chunk_fn &&
4547             !dev->param.read_chunk_fn &&
4548             dev->param.bad_block_fn && dev->param.query_block_fn)
4549                 return 1;
4550 #endif
4551
4552         /* Can use the "spare" style interface for yaffs1 */
4553         if (!dev->param.is_yaffs2 &&
4554             !dev->param.write_chunk_tags_fn &&
4555             !dev->param.read_chunk_tags_fn &&
4556             dev->param.write_chunk_fn &&
4557             dev->param.read_chunk_fn &&
4558             !dev->param.bad_block_fn && !dev->param.query_block_fn)
4559                 return 1;
4560
4561         return 0;               /* bad */
4562 }
4563
4564 static int yaffs_create_initial_dir(struct yaffs_dev *dev)
4565 {
4566         /* Initialise the unlinked, deleted, root and lost+found directories */
4567         dev->lost_n_found = dev->root_dir = NULL;
4568         dev->unlinked_dir = dev->del_dir = NULL;
4569         dev->unlinked_dir =
4570             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_UNLINKED, S_IFDIR);
4571         dev->del_dir =
4572             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_DELETED, S_IFDIR);
4573         dev->root_dir =
4574             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_ROOT,
4575                                   YAFFS_ROOT_MODE | S_IFDIR);
4576         dev->lost_n_found =
4577             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_LOSTNFOUND,
4578                                   YAFFS_LOSTNFOUND_MODE | S_IFDIR);
4579
4580         if (dev->lost_n_found && dev->root_dir && dev->unlinked_dir
4581             && dev->del_dir) {
4582                 yaffs_add_obj_to_dir(dev->root_dir, dev->lost_n_found);
4583                 return YAFFS_OK;
4584         }
4585         return YAFFS_FAIL;
4586 }
4587
4588 int yaffs_guts_initialise(struct yaffs_dev *dev)
4589 {
4590         int init_failed = 0;
4591         unsigned x;
4592         int bits;
4593
4594         yaffs_trace(YAFFS_TRACE_TRACING, "yaffs: yaffs_guts_initialise()");
4595
4596         /* Check stuff that must be set */
4597
4598         if (!dev) {
4599                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4600                         "yaffs: Need a device"
4601                         );
4602                 return YAFFS_FAIL;
4603         }
4604
4605         if (dev->is_mounted) {
4606                 yaffs_trace(YAFFS_TRACE_ALWAYS, "device already mounted");
4607                 return YAFFS_FAIL;
4608         }
4609
4610         dev->internal_start_block = dev->param.start_block;
4611         dev->internal_end_block = dev->param.end_block;
4612         dev->block_offset = 0;
4613         dev->chunk_offset = 0;
4614         dev->n_free_chunks = 0;
4615
4616         dev->gc_block = 0;
4617
4618         if (dev->param.start_block == 0) {
4619                 dev->internal_start_block = dev->param.start_block + 1;
4620                 dev->internal_end_block = dev->param.end_block + 1;
4621                 dev->block_offset = 1;
4622                 dev->chunk_offset = dev->param.chunks_per_block;
4623         }
4624
4625         /* Check geometry parameters. */
4626
4627         if ((!dev->param.inband_tags && dev->param.is_yaffs2 &&
4628                 dev->param.total_bytes_per_chunk < 1024) ||
4629                 (!dev->param.is_yaffs2 &&
4630                         dev->param.total_bytes_per_chunk < 512) ||
4631                 (dev->param.inband_tags && !dev->param.is_yaffs2) ||
4632                  dev->param.chunks_per_block < 2 ||
4633                  dev->param.n_reserved_blocks < 2 ||
4634                 dev->internal_start_block <= 0 ||
4635                 dev->internal_end_block <= 0 ||
4636                 dev->internal_end_block <=
4637                 (dev->internal_start_block + dev->param.n_reserved_blocks + 2)
4638                 ) {
4639                 /* otherwise it is too small */
4640                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4641                         "NAND geometry problems: chunk size %d, type is yaffs%s, inband_tags %d ",
4642                         dev->param.total_bytes_per_chunk,
4643                         dev->param.is_yaffs2 ? "2" : "",
4644                         dev->param.inband_tags);
4645                 return YAFFS_FAIL;
4646         }
4647
4648         if (yaffs_init_nand(dev) != YAFFS_OK) {
4649                 yaffs_trace(YAFFS_TRACE_ALWAYS, "InitialiseNAND failed");
4650                 return YAFFS_FAIL;
4651         }
4652
4653         /* Sort out space for inband tags, if required */
4654         if (dev->param.inband_tags)
4655                 dev->data_bytes_per_chunk =
4656                     dev->param.total_bytes_per_chunk -
4657                     sizeof(struct yaffs_packed_tags2_tags_only);
4658         else
4659                 dev->data_bytes_per_chunk = dev->param.total_bytes_per_chunk;
4660
4661         /* Got the right mix of functions? */
4662         if (!yaffs_check_dev_fns(dev)) {
4663                 /* Function missing */
4664                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4665                         "device function(s) missing or wrong");
4666
4667                 return YAFFS_FAIL;
4668         }
4669
4670         /* Finished with most checks. Further checks happen later on too. */
4671
4672         dev->is_mounted = 1;
4673
4674         /* OK now calculate a few things for the device */
4675
4676         /*
4677          *  Calculate all the chunk size manipulation numbers:
4678          */
4679         x = dev->data_bytes_per_chunk;
4680         /* We always use dev->chunk_shift and dev->chunk_div */
4681         dev->chunk_shift = calc_shifts(x);
4682         x >>= dev->chunk_shift;
4683         dev->chunk_div = x;
4684         /* We only use chunk mask if chunk_div is 1 */
4685         dev->chunk_mask = (1 << dev->chunk_shift) - 1;
4686
4687         /*
4688          * Calculate chunk_grp_bits.
4689          * We need to find the next power of 2 > than internal_end_block
4690          */
4691
4692         x = dev->param.chunks_per_block * (dev->internal_end_block + 1);
4693
4694         bits = calc_shifts_ceiling(x);
4695
4696         /* Set up tnode width if wide tnodes are enabled. */
4697         if (!dev->param.wide_tnodes_disabled) {
4698                 /* bits must be even so that we end up with 32-bit words */
4699                 if (bits & 1)
4700                         bits++;
4701                 if (bits < 16)
4702                         dev->tnode_width = 16;
4703                 else
4704                         dev->tnode_width = bits;
4705         } else {
4706                 dev->tnode_width = 16;
4707         }
4708
4709         dev->tnode_mask = (1 << dev->tnode_width) - 1;
4710
4711         /* Level0 Tnodes are 16 bits or wider (if wide tnodes are enabled),
4712          * so if the bitwidth of the
4713          * chunk range we're using is greater than 16 we need
4714          * to figure out chunk shift and chunk_grp_size
4715          */
4716
4717         if (bits <= dev->tnode_width)
4718                 dev->chunk_grp_bits = 0;
4719         else
4720                 dev->chunk_grp_bits = bits - dev->tnode_width;
4721
4722         dev->tnode_size = (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8;
4723         if (dev->tnode_size < sizeof(struct yaffs_tnode))
4724                 dev->tnode_size = sizeof(struct yaffs_tnode);
4725
4726         dev->chunk_grp_size = 1 << dev->chunk_grp_bits;
4727
4728         if (dev->param.chunks_per_block < dev->chunk_grp_size) {
4729                 /* We have a problem because the soft delete won't work if
4730                  * the chunk group size > chunks per block.
4731                  * This can be remedied by using larger "virtual blocks".
4732                  */
4733                 yaffs_trace(YAFFS_TRACE_ALWAYS, "chunk group too large");
4734
4735                 return YAFFS_FAIL;
4736         }
4737
4738         /* Finished verifying the device, continue with initialisation */
4739
4740         /* More device initialisation */
4741         dev->all_gcs = 0;
4742         dev->passive_gc_count = 0;
4743         dev->oldest_dirty_gc_count = 0;
4744         dev->bg_gcs = 0;
4745         dev->gc_block_finder = 0;
4746         dev->buffered_block = -1;
4747         dev->doing_buffered_block_rewrite = 0;
4748         dev->n_deleted_files = 0;
4749         dev->n_bg_deletions = 0;
4750         dev->n_unlinked_files = 0;
4751         dev->n_ecc_fixed = 0;
4752         dev->n_ecc_unfixed = 0;
4753         dev->n_tags_ecc_fixed = 0;
4754         dev->n_tags_ecc_unfixed = 0;
4755         dev->n_erase_failures = 0;
4756         dev->n_erased_blocks = 0;
4757         dev->gc_disable = 0;
4758         dev->has_pending_prioritised_gc = 1;
4759                 /* Assume the worst for now, will get fixed on first GC */
4760         INIT_LIST_HEAD(&dev->dirty_dirs);
4761         dev->oldest_dirty_seq = 0;
4762         dev->oldest_dirty_block = 0;
4763
4764         /* Initialise temporary buffers and caches. */
4765         if (!yaffs_init_tmp_buffers(dev))
4766                 init_failed = 1;
4767
4768         dev->cache = NULL;
4769         dev->gc_cleanup_list = NULL;
4770
4771         if (!init_failed && dev->param.n_caches > 0) {
4772                 int i;
4773                 void *buf;
4774                 int cache_bytes =
4775                     dev->param.n_caches * sizeof(struct yaffs_cache);
4776
4777                 if (dev->param.n_caches > YAFFS_MAX_SHORT_OP_CACHES)
4778                         dev->param.n_caches = YAFFS_MAX_SHORT_OP_CACHES;
4779
4780                 dev->cache = kmalloc(cache_bytes, GFP_NOFS);
4781
4782                 buf = (u8 *) dev->cache;
4783
4784                 if (dev->cache)
4785                         memset(dev->cache, 0, cache_bytes);
4786
4787                 for (i = 0; i < dev->param.n_caches && buf; i++) {
4788                         dev->cache[i].object = NULL;
4789                         dev->cache[i].last_use = 0;
4790                         dev->cache[i].dirty = 0;
4791                         dev->cache[i].data = buf =
4792                             kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
4793                 }
4794                 if (!buf)
4795                         init_failed = 1;
4796
4797                 dev->cache_last_use = 0;
4798         }
4799
4800         dev->cache_hits = 0;
4801
4802         if (!init_failed) {
4803                 dev->gc_cleanup_list =
4804                     kmalloc(dev->param.chunks_per_block * sizeof(u32),
4805                                         GFP_NOFS);
4806                 if (!dev->gc_cleanup_list)
4807                         init_failed = 1;
4808         }
4809
4810         if (dev->param.is_yaffs2)
4811                 dev->param.use_header_file_size = 1;
4812
4813         if (!init_failed && !yaffs_init_blocks(dev))
4814                 init_failed = 1;
4815
4816         yaffs_init_tnodes_and_objs(dev);
4817
4818         if (!init_failed && !yaffs_create_initial_dir(dev))
4819                 init_failed = 1;
4820
4821         if(!init_failed && dev->param.is_yaffs2 &&
4822                 !dev->param.disable_summary &&
4823                 !yaffs_summary_init(dev))
4824                 init_failed = 1;
4825
4826         if (!init_failed) {
4827                 /* Now scan the flash. */
4828                 if (dev->param.is_yaffs2) {
4829                         if (yaffs2_checkpt_restore(dev)) {
4830                                 yaffs_check_obj_details_loaded(dev->root_dir);
4831                                 yaffs_trace(YAFFS_TRACE_CHECKPOINT |
4832                                         YAFFS_TRACE_MOUNT,
4833                                         "yaffs: restored from checkpoint"
4834                                         );
4835                         } else {
4836
4837                                 /* Clean up the mess caused by an aborted
4838                                  * checkpoint load then scan backwards.
4839                                  */
4840                                 yaffs_deinit_blocks(dev);
4841
4842                                 yaffs_deinit_tnodes_and_objs(dev);
4843
4844                                 dev->n_erased_blocks = 0;
4845                                 dev->n_free_chunks = 0;
4846                                 dev->alloc_block = -1;
4847                                 dev->alloc_page = -1;
4848                                 dev->n_deleted_files = 0;
4849                                 dev->n_unlinked_files = 0;
4850                                 dev->n_bg_deletions = 0;
4851
4852                                 if (!init_failed && !yaffs_init_blocks(dev))
4853                                         init_failed = 1;
4854
4855                                 yaffs_init_tnodes_and_objs(dev);
4856
4857                                 if (!init_failed
4858                                     && !yaffs_create_initial_dir(dev))
4859                                         init_failed = 1;
4860
4861                                 if (!init_failed && !yaffs2_scan_backwards(dev))
4862                                         init_failed = 1;
4863                         }
4864                 } else if (!yaffs1_scan(dev)) {
4865                         init_failed = 1;
4866                 }
4867
4868                 yaffs_strip_deleted_objs(dev);
4869                 yaffs_fix_hanging_objs(dev);
4870                 if (dev->param.empty_lost_n_found)
4871                         yaffs_empty_l_n_f(dev);
4872         }
4873
4874         if (init_failed) {
4875                 /* Clean up the mess */
4876                 yaffs_trace(YAFFS_TRACE_TRACING,
4877                   "yaffs: yaffs_guts_initialise() aborted.");
4878
4879                 yaffs_deinitialise(dev);
4880                 return YAFFS_FAIL;
4881         }
4882
4883         /* Zero out stats */
4884         dev->n_page_reads = 0;
4885         dev->n_page_writes = 0;
4886         dev->n_erasures = 0;
4887         dev->n_gc_copies = 0;
4888         dev->n_retired_writes = 0;
4889
4890         dev->n_retired_blocks = 0;
4891
4892         yaffs_verify_free_chunks(dev);
4893         yaffs_verify_blocks(dev);
4894
4895         /* Clean up any aborted checkpoint data */
4896         if (!dev->is_checkpointed && dev->blocks_in_checkpt > 0)
4897                 yaffs2_checkpt_invalidate(dev);
4898
4899         yaffs_trace(YAFFS_TRACE_TRACING,
4900           "yaffs: yaffs_guts_initialise() done.");
4901         return YAFFS_OK;
4902 }
4903
4904 void yaffs_deinitialise(struct yaffs_dev *dev)
4905 {
4906         if (dev->is_mounted) {
4907                 int i;
4908
4909                 yaffs_deinit_blocks(dev);
4910                 yaffs_deinit_tnodes_and_objs(dev);
4911                 yaffs_summary_deinit(dev);
4912
4913                 if (dev->param.n_caches > 0 && dev->cache) {
4914
4915                         for (i = 0; i < dev->param.n_caches; i++) {
4916                                 kfree(dev->cache[i].data);
4917                                 dev->cache[i].data = NULL;
4918                         }
4919
4920                         kfree(dev->cache);
4921                         dev->cache = NULL;
4922                 }
4923
4924                 kfree(dev->gc_cleanup_list);
4925
4926                 for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++)
4927                         kfree(dev->temp_buffer[i].buffer);
4928
4929                 dev->is_mounted = 0;
4930
4931                 if (dev->param.deinitialise_flash_fn)
4932                         dev->param.deinitialise_flash_fn(dev);
4933         }
4934 }
4935
4936 int yaffs_count_free_chunks(struct yaffs_dev *dev)
4937 {
4938         int n_free = 0;
4939         int b;
4940         struct yaffs_block_info *blk;
4941
4942         blk = dev->block_info;
4943         for (b = dev->internal_start_block; b <= dev->internal_end_block; b++) {
4944                 switch (blk->block_state) {
4945                 case YAFFS_BLOCK_STATE_EMPTY:
4946                 case YAFFS_BLOCK_STATE_ALLOCATING:
4947                 case YAFFS_BLOCK_STATE_COLLECTING:
4948                 case YAFFS_BLOCK_STATE_FULL:
4949                         n_free +=
4950                             (dev->param.chunks_per_block - blk->pages_in_use +
4951                              blk->soft_del_pages);
4952                         break;
4953                 default:
4954                         break;
4955                 }
4956                 blk++;
4957         }
4958         return n_free;
4959 }
4960
4961 int yaffs_get_n_free_chunks(struct yaffs_dev *dev)
4962 {
4963         /* This is what we report to the outside world */
4964         int n_free;
4965         int n_dirty_caches;
4966         int blocks_for_checkpt;
4967         int i;
4968
4969         n_free = dev->n_free_chunks;
4970         n_free += dev->n_deleted_files;
4971
4972         /* Now count and subtract the number of dirty chunks in the cache. */
4973
4974         for (n_dirty_caches = 0, i = 0; i < dev->param.n_caches; i++) {
4975                 if (dev->cache[i].dirty)
4976                         n_dirty_caches++;
4977         }
4978
4979         n_free -= n_dirty_caches;
4980
4981         n_free -=
4982             ((dev->param.n_reserved_blocks + 1) * dev->param.chunks_per_block);
4983
4984         /* Now figure checkpoint space and report that... */
4985         blocks_for_checkpt = yaffs_calc_checkpt_blocks_required(dev);
4986
4987         n_free -= (blocks_for_checkpt * dev->param.chunks_per_block);
4988
4989         if (n_free < 0)
4990                 n_free = 0;
4991
4992         return n_free;
4993 }