fs/yaffs2/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 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,
 181                         "Releasing unmanaged temp buffer");
 182                 kfree(buffer);
 183                 dev->unmanaged_buffer_deallocs++;
 184         }
 185
 186 }
 187
 188 /*
 189  * Determine if we have a managed buffer.
 190  */
 191 int yaffs_is_managed_tmp_buffer(struct yaffs_dev *dev, const u8 *buffer)
 192 {
 193         int i;
 194
 195         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
 196                 if (dev->temp_buffer[i].buffer == buffer)
 197                         return 1;
 198         }
 199
 200         for (i = 0; i < dev->param.n_caches; i++) {
 201                 if (dev->cache[i].data == buffer)
 202                         return 1;
 203         }
 204
 205         if (buffer == dev->checkpt_buffer)
 206                 return 1;
 207
 208         yaffs_trace(YAFFS_TRACE_ALWAYS,
 209           "yaffs: unmaged buffer detected.");
 210         return 0;
 211 }
 212
 213 /*
 214  * Functions for robustisizing TODO
 215  *
 216  */
 217
 218 static void yaffs_handle_chunk_wr_ok(struct yaffs_dev *dev, int nand_chunk,
 219                                      const u8 *data,
 220                                      const struct yaffs_ext_tags *tags)
 221 {
 222         dev = dev;
 223         nand_chunk = nand_chunk;
 224         data = data;
 225         tags = tags;
 226 }
 227
 228 static void yaffs_handle_chunk_update(struct yaffs_dev *dev, int nand_chunk,
 229                                       const struct yaffs_ext_tags *tags)
 230 {
 231         dev = dev;
 232         nand_chunk = nand_chunk;
 233         tags = tags;
 234 }
 235
 236 void yaffs_handle_chunk_error(struct yaffs_dev *dev,
 237                               struct yaffs_block_info *bi)
 238 {
 239         if (!bi->gc_prioritise) {
 240                 bi->gc_prioritise = 1;
 241                 dev->has_pending_prioritised_gc = 1;
 242                 bi->chunk_error_strikes++;
 243
 244                 if (bi->chunk_error_strikes > 3) {
 245                         bi->needs_retiring = 1; /* Too many stikes, so retire */
 246                         yaffs_trace(YAFFS_TRACE_ALWAYS,
 247                                 "yaffs: Block struck out");
 248
 249                 }
 250         }
 251 }
 252
 253 static void yaffs_handle_chunk_wr_error(struct yaffs_dev *dev, int nand_chunk,
 254                                         int erased_ok)
 255 {
 256         int flash_block = nand_chunk / dev->param.chunks_per_block;
 257         struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
 258
 259         yaffs_handle_chunk_error(dev, bi);
 260
 261         if (erased_ok) {
 262                 /* Was an actual write failure,
 263                  * so mark the block for retirement.*/
 264                 bi->needs_retiring = 1;
 265                 yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
 266                   "**>> Block %d needs retiring", flash_block);
 267         }
 268
 269         /* Delete the chunk */
 270         yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
 271         yaffs_skip_rest_of_block(dev);
 272 }
 273
 274 /*
 275  * Verification code
 276  */
 277
 278 /*
 279  *  Simple hash function. Needs to have a reasonable spread
 280  */
 281
 282 static inline int yaffs_hash_fn(int n)
 283 {
 284         if (n < 0)
 285                 n = -n;
 286         return n % YAFFS_NOBJECT_BUCKETS;
 287 }
 288
 289 /*
 290  * Access functions to useful fake objects.
 291  * Note that root might have a presence in NAND if permissions are set.
 292  */
 293
 294 struct yaffs_obj *yaffs_root(struct yaffs_dev *dev)
 295 {
 296         return dev->root_dir;
 297 }
 298
 299 struct yaffs_obj *yaffs_lost_n_found(struct yaffs_dev *dev)
 300 {
 301         return dev->lost_n_found;
 302 }
 303
 304 /*
 305  *  Erased NAND checking functions
 306  */
 307
 308 int yaffs_check_ff(u8 *buffer, int n_bytes)
 309 {
 310         /* Horrible, slow implementation */
 311         while (n_bytes--) {
 312                 if (*buffer != 0xff)
 313                         return 0;
 314                 buffer++;
 315         }
 316         return 1;
 317 }
 318
 319 static int yaffs_check_chunk_erased(struct yaffs_dev *dev, int nand_chunk)
 320 {
 321         int retval = YAFFS_OK;
 322         u8 *data = yaffs_get_temp_buffer(dev);
 323         struct yaffs_ext_tags tags;
 324
 325         yaffs_rd_chunk_tags_nand(dev, nand_chunk, data, &tags);
 326
 327         if (tags.ecc_result > YAFFS_ECC_RESULT_NO_ERROR)
 328                 retval = YAFFS_FAIL;
 329
 330         if (!yaffs_check_ff(data, dev->data_bytes_per_chunk) ||
 331                 tags.chunk_used) {
 332                 yaffs_trace(YAFFS_TRACE_NANDACCESS,
 333                         "Chunk %d not erased", nand_chunk);
 334                 retval = YAFFS_FAIL;
 335         }
 336
 337         yaffs_release_temp_buffer(dev, data);
 338
 339         return retval;
 340
 341 }
 342
 343 static int yaffs_verify_chunk_written(struct yaffs_dev *dev,
 344                                       int nand_chunk,
 345                                       const u8 *data,
 346                                       struct yaffs_ext_tags *tags)
 347 {
 348         int retval = YAFFS_OK;
 349         struct yaffs_ext_tags temp_tags;
 350         u8 *buffer = yaffs_get_temp_buffer(dev);
 351
 352         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_retried_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         memset(obj->short_name, 0, sizeof(obj->short_name));
 676         if (name &&
 677                 yaffs_strnlen(name, YAFFS_SHORT_NAME_LENGTH + 1) <=
 678                 YAFFS_SHORT_NAME_LENGTH)
 679                 yaffs_strcpy(obj->short_name, name);
 680         else
 681                 obj->short_name[0] = _Y('\0');
 682         obj->sum = yaffs_calc_name_sum(name);
 683 }
 684
 685 void yaffs_set_obj_name_from_oh(struct yaffs_obj *obj,
 686                                 const struct yaffs_obj_hdr *oh)
 687 {
 688 #ifdef CONFIG_YAFFS_AUTO_UNICODE
 689         YCHAR tmp_name[YAFFS_MAX_NAME_LENGTH + 1];
 690         memset(tmp_name, 0, sizeof(tmp_name));
 691         yaffs_load_name_from_oh(obj->my_dev, tmp_name, oh->name,
 692                                 YAFFS_MAX_NAME_LENGTH + 1);
 693         yaffs_set_obj_name(obj, tmp_name);
 694 #else
 695         yaffs_set_obj_name(obj, oh->name);
 696 #endif
 697 }
 698
 699 loff_t yaffs_max_file_size(struct yaffs_dev *dev)
 700 {
 701         return ((loff_t) YAFFS_MAX_CHUNK_ID) * dev->data_bytes_per_chunk;
 702 }
 703
 704 /*-------------------- TNODES -------------------
 705
 706  * List of spare tnodes
 707  * The list is hooked together using the first pointer
 708  * in the tnode.
 709  */
 710
 711 struct yaffs_tnode *yaffs_get_tnode(struct yaffs_dev *dev)
 712 {
 713         struct yaffs_tnode *tn = yaffs_alloc_raw_tnode(dev);
 714
 715         if (tn) {
 716                 memset(tn, 0, dev->tnode_size);
 717                 dev->n_tnodes++;
 718         }
 719
 720         dev->checkpoint_blocks_required = 0;    /* force recalculation */
 721
 722         return tn;
 723 }
 724
 725 /* FreeTnode frees up a tnode and puts it back on the free list */
 726 static void yaffs_free_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
 727 {
 728         yaffs_free_raw_tnode(dev, tn);
 729         dev->n_tnodes--;
 730         dev->checkpoint_blocks_required = 0;    /* force recalculation */
 731 }
 732
 733 static void yaffs_deinit_tnodes_and_objs(struct yaffs_dev *dev)
 734 {
 735         yaffs_deinit_raw_tnodes_and_objs(dev);
 736         dev->n_obj = 0;
 737         dev->n_tnodes = 0;
 738 }
 739
 740 void yaffs_load_tnode_0(struct yaffs_dev *dev, struct yaffs_tnode *tn,
 741                         unsigned pos, unsigned val)
 742 {
 743         u32 *map = (u32 *) tn;
 744         u32 bit_in_map;
 745         u32 bit_in_word;
 746         u32 word_in_map;
 747         u32 mask;
 748
 749         pos &= YAFFS_TNODES_LEVEL0_MASK;
 750         val >>= dev->chunk_grp_bits;
 751
 752         bit_in_map = pos * dev->tnode_width;
 753         word_in_map = bit_in_map / 32;
 754         bit_in_word = bit_in_map & (32 - 1);
 755
 756         mask = dev->tnode_mask << bit_in_word;
 757
 758         map[word_in_map] &= ~mask;
 759         map[word_in_map] |= (mask & (val << bit_in_word));
 760
 761         if (dev->tnode_width > (32 - bit_in_word)) {
 762                 bit_in_word = (32 - bit_in_word);
 763                 word_in_map++;
 764                 mask =
 765                     dev->tnode_mask >> bit_in_word;
 766                 map[word_in_map] &= ~mask;
 767                 map[word_in_map] |= (mask & (val >> bit_in_word));
 768         }
 769 }
 770
 771 u32 yaffs_get_group_base(struct yaffs_dev *dev, struct yaffs_tnode *tn,
 772                          unsigned pos)
 773 {
 774         u32 *map = (u32 *) tn;
 775         u32 bit_in_map;
 776         u32 bit_in_word;
 777         u32 word_in_map;
 778         u32 val;
 779
 780         pos &= YAFFS_TNODES_LEVEL0_MASK;
 781
 782         bit_in_map = pos * dev->tnode_width;
 783         word_in_map = bit_in_map / 32;
 784         bit_in_word = bit_in_map & (32 - 1);
 785
 786         val = map[word_in_map] >> bit_in_word;
 787
 788         if (dev->tnode_width > (32 - bit_in_word)) {
 789                 bit_in_word = (32 - bit_in_word);
 790                 word_in_map++;
 791                 val |= (map[word_in_map] << bit_in_word);
 792         }
 793
 794         val &= dev->tnode_mask;
 795         val <<= dev->chunk_grp_bits;
 796
 797         return val;
 798 }
 799
 800 /* ------------------- End of individual tnode manipulation -----------------*/
 801
 802 /* ---------Functions to manipulate the look-up tree (made up of tnodes) ------
 803  * The look up tree is represented by the top tnode and the number of top_level
 804  * in the tree. 0 means only the level 0 tnode is in the tree.
 805  */
 806
 807 /* FindLevel0Tnode finds the level 0 tnode, if one exists. */
 808 struct yaffs_tnode *yaffs_find_tnode_0(struct yaffs_dev *dev,
 809                                        struct yaffs_file_var *file_struct,
 810                                        u32 chunk_id)
 811 {
 812         struct yaffs_tnode *tn = file_struct->top;
 813         u32 i;
 814         int required_depth;
 815         int level = file_struct->top_level;
 816
 817         dev = dev;
 818
 819         /* Check sane level and chunk Id */
 820         if (level < 0 || level > YAFFS_TNODES_MAX_LEVEL)
 821                 return NULL;
 822
 823         if (chunk_id > YAFFS_MAX_CHUNK_ID)
 824                 return NULL;
 825
 826         /* First check we're tall enough (ie enough top_level) */
 827
 828         i = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
 829         required_depth = 0;
 830         while (i) {
 831                 i >>= YAFFS_TNODES_INTERNAL_BITS;
 832                 required_depth++;
 833         }
 834
 835         if (required_depth > file_struct->top_level)
 836                 return NULL;    /* Not tall enough, so we can't find it */
 837
 838         /* Traverse down to level 0 */
 839         while (level > 0 && tn) {
 840                 tn = tn->internal[(chunk_id >>
 841                                    (YAFFS_TNODES_LEVEL0_BITS +
 842                                     (level - 1) *
 843                                     YAFFS_TNODES_INTERNAL_BITS)) &
 844                                   YAFFS_TNODES_INTERNAL_MASK];
 845                 level--;
 846         }
 847
 848         return tn;
 849 }
 850
 851 /* add_find_tnode_0 finds the level 0 tnode if it exists,
 852  * otherwise first expands the tree.
 853  * This happens in two steps:
 854  *  1. If the tree isn't tall enough, then make it taller.
 855  *  2. Scan down the tree towards the level 0 tnode adding tnodes if required.
 856  *
 857  * Used when modifying the tree.
 858  *
 859  *  If the tn argument is NULL, then a fresh tnode will be added otherwise the
 860  *  specified tn will be plugged into the ttree.
 861  */
 862
 863 struct yaffs_tnode *yaffs_add_find_tnode_0(struct yaffs_dev *dev,
 864                                            struct yaffs_file_var *file_struct,
 865                                            u32 chunk_id,
 866                                            struct yaffs_tnode *passed_tn)
 867 {
 868         int required_depth;
 869         int i;
 870         int l;
 871         struct yaffs_tnode *tn;
 872         u32 x;
 873
 874         /* Check sane level and page Id */
 875         if (file_struct->top_level < 0 ||
 876             file_struct->top_level > YAFFS_TNODES_MAX_LEVEL)
 877                 return NULL;
 878
 879         if (chunk_id > YAFFS_MAX_CHUNK_ID)
 880                 return NULL;
 881
 882         /* First check we're tall enough (ie enough top_level) */
 883
 884         x = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
 885         required_depth = 0;
 886         while (x) {
 887                 x >>= YAFFS_TNODES_INTERNAL_BITS;
 888                 required_depth++;
 889         }
 890
 891         if (required_depth > file_struct->top_level) {
 892                 /* Not tall enough, gotta make the tree taller */
 893                 for (i = file_struct->top_level; i < required_depth; i++) {
 894
 895                         tn = yaffs_get_tnode(dev);
 896
 897                         if (tn) {
 898                                 tn->internal[0] = file_struct->top;
 899                                 file_struct->top = tn;
 900                                 file_struct->top_level++;
 901                         } else {
 902                                 yaffs_trace(YAFFS_TRACE_ERROR,
 903                                         "yaffs: no more tnodes");
 904                                 return NULL;
 905                         }
 906                 }
 907         }
 908
 909         /* Traverse down to level 0, adding anything we need */
 910
 911         l = file_struct->top_level;
 912         tn = file_struct->top;
 913
 914         if (l > 0) {
 915                 while (l > 0 && tn) {
 916                         x = (chunk_id >>
 917                              (YAFFS_TNODES_LEVEL0_BITS +
 918                               (l - 1) * YAFFS_TNODES_INTERNAL_BITS)) &
 919                             YAFFS_TNODES_INTERNAL_MASK;
 920
 921                         if ((l > 1) && !tn->internal[x]) {
 922                                 /* Add missing non-level-zero tnode */
 923                                 tn->internal[x] = yaffs_get_tnode(dev);
 924                                 if (!tn->internal[x])
 925                                         return NULL;
 926                         } else if (l == 1) {
 927                                 /* Looking from level 1 at level 0 */
 928                                 if (passed_tn) {
 929                                         /* If we already have one, release it */
 930                                         if (tn->internal[x])
 931                                                 yaffs_free_tnode(dev,
 932                                                         tn->internal[x]);
 933                                         tn->internal[x] = passed_tn;
 934
 935                                 } else if (!tn->internal[x]) {
 936                                         /* Don't have one, none passed in */
 937                                         tn->internal[x] = yaffs_get_tnode(dev);
 938                                         if (!tn->internal[x])
 939                                                 return NULL;
 940                                 }
 941                         }
 942
 943                         tn = tn->internal[x];
 944                         l--;
 945                 }
 946         } else {
 947                 /* top is level 0 */
 948                 if (passed_tn) {
 949                         memcpy(tn, passed_tn,
 950                                (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8);
 951                         yaffs_free_tnode(dev, passed_tn);
 952                 }
 953         }
 954
 955         return tn;
 956 }
 957
 958 static int yaffs_tags_match(const struct yaffs_ext_tags *tags, int obj_id,
 959                             int chunk_obj)
 960 {
 961         return (tags->chunk_id == chunk_obj &&
 962                 tags->obj_id == obj_id &&
 963                 !tags->is_deleted) ? 1 : 0;
 964
 965 }
 966
 967 static int yaffs_find_chunk_in_group(struct yaffs_dev *dev, int the_chunk,
 968                                         struct yaffs_ext_tags *tags, int obj_id,
 969                                         int inode_chunk)
 970 {
 971         int j;
 972
 973         for (j = 0; the_chunk && j < dev->chunk_grp_size; j++) {
 974                 if (yaffs_check_chunk_bit
 975                     (dev, the_chunk / dev->param.chunks_per_block,
 976                      the_chunk % dev->param.chunks_per_block)) {
 977
 978                         if (dev->chunk_grp_size == 1)
 979                                 return the_chunk;
 980                         else {
 981                                 yaffs_rd_chunk_tags_nand(dev, the_chunk, NULL,
 982                                                          tags);
 983                                 if (yaffs_tags_match(tags,
 984                                                         obj_id, inode_chunk)) {
 985                                         /* found it; */
 986                                         return the_chunk;
 987                                 }
 988                         }
 989                 }
 990                 the_chunk++;
 991         }
 992         return -1;
 993 }
 994
 995 static int yaffs_find_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
 996                                     struct yaffs_ext_tags *tags)
 997 {
 998         /*Get the Tnode, then get the level 0 offset chunk offset */
 999         struct yaffs_tnode *tn;
1000         int the_chunk = -1;
1001         struct yaffs_ext_tags local_tags;
1002         int ret_val = -1;
1003         struct yaffs_dev *dev = in->my_dev;
1004
1005         if (!tags) {
1006                 /* Passed a NULL, so use our own tags space */
1007                 tags = &local_tags;
1008         }
1009
1010         tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
1011
1012         if (!tn)
1013                 return ret_val;
1014
1015         the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
1016
1017         ret_val = yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
1018                                               inode_chunk);
1019         return ret_val;
1020 }
1021
1022 static int yaffs_find_del_file_chunk(struct yaffs_obj *in, int inode_chunk,
1023                                      struct yaffs_ext_tags *tags)
1024 {
1025         /* Get the Tnode, then get the level 0 offset chunk offset */
1026         struct yaffs_tnode *tn;
1027         int the_chunk = -1;
1028         struct yaffs_ext_tags local_tags;
1029         struct yaffs_dev *dev = in->my_dev;
1030         int ret_val = -1;
1031
1032         if (!tags) {
1033                 /* Passed a NULL, so use our own tags space */
1034                 tags = &local_tags;
1035         }
1036
1037         tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
1038
1039         if (!tn)
1040                 return ret_val;
1041
1042         the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
1043
1044         ret_val = yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
1045                                               inode_chunk);
1046
1047         /* Delete the entry in the filestructure (if found) */
1048         if (ret_val != -1)
1049                 yaffs_load_tnode_0(dev, tn, inode_chunk, 0);
1050
1051         return ret_val;
1052 }
1053
1054 int yaffs_put_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
1055                             int nand_chunk, int in_scan)
1056 {
1057         /* NB in_scan is zero unless scanning.
1058          * For forward scanning, in_scan is > 0;
1059          * for backward scanning in_scan is < 0
1060          *
1061          * nand_chunk = 0 is a dummy insert to make sure the tnodes are there.
1062          */
1063
1064         struct yaffs_tnode *tn;
1065         struct yaffs_dev *dev = in->my_dev;
1066         int existing_cunk;
1067         struct yaffs_ext_tags existing_tags;
1068         struct yaffs_ext_tags new_tags;
1069         unsigned existing_serial, new_serial;
1070
1071         if (in->variant_type != YAFFS_OBJECT_TYPE_FILE) {
1072                 /* Just ignore an attempt at putting a chunk into a non-file
1073                  * during scanning.
1074                  * If it is not during Scanning then something went wrong!
1075                  */
1076                 if (!in_scan) {
1077                         yaffs_trace(YAFFS_TRACE_ERROR,
1078                                 "yaffs tragedy:attempt to put data chunk into a non-file"
1079                                 );
1080                         BUG();
1081                 }
1082
1083                 yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
1084                 return YAFFS_OK;
1085         }
1086
1087         tn = yaffs_add_find_tnode_0(dev,
1088                                     &in->variant.file_variant,
1089                                     inode_chunk, NULL);
1090         if (!tn)
1091                 return YAFFS_FAIL;
1092
1093         if (!nand_chunk)
1094                 /* Dummy insert, bail now */
1095                 return YAFFS_OK;
1096
1097         existing_cunk = yaffs_get_group_base(dev, tn, inode_chunk);
1098
1099         if (in_scan != 0) {
1100                 /* If we're scanning then we need to test for duplicates
1101                  * NB This does not need to be efficient since it should only
1102                  * happen when the power fails during a write, then only one
1103                  * chunk should ever be affected.
1104                  *
1105                  * Correction for YAFFS2: This could happen quite a lot and we
1106                  * need to think about efficiency! TODO
1107                  * Update: For backward scanning we don't need to re-read tags
1108                  * so this is quite cheap.
1109                  */
1110
1111                 if (existing_cunk > 0) {
1112                         /* NB Right now existing chunk will not be real
1113                          * chunk_id if the chunk group size > 1
1114                          * thus we have to do a FindChunkInFile to get the
1115                          * real chunk id.
1116                          *
1117                          * We have a duplicate now we need to decide which
1118                          * one to use:
1119                          *
1120                          * Backwards scanning YAFFS2: The old one is what
1121                          * we use, dump the new one.
1122                          * YAFFS1: Get both sets of tags and compare serial
1123                          * numbers.
1124                          */
1125
1126                         if (in_scan > 0) {
1127                                 /* Only do this for forward scanning */
1128                                 yaffs_rd_chunk_tags_nand(dev,
1129                                                          nand_chunk,
1130                                                          NULL, &new_tags);
1131
1132                                 /* Do a proper find */
1133                                 existing_cunk =
1134                                     yaffs_find_chunk_in_file(in, inode_chunk,
1135                                                              &existing_tags);
1136                         }
1137
1138                         if (existing_cunk <= 0) {
1139                                 /*Hoosterman - how did this happen? */
1140
1141                                 yaffs_trace(YAFFS_TRACE_ERROR,
1142                                         "yaffs tragedy: existing chunk < 0 in scan"
1143                                         );
1144
1145                         }
1146
1147                         /* NB The deleted flags should be false, otherwise
1148                          * the chunks will not be loaded during a scan
1149                          */
1150
1151                         if (in_scan > 0) {
1152                                 new_serial = new_tags.serial_number;
1153                                 existing_serial = existing_tags.serial_number;
1154                         }
1155
1156                         if ((in_scan > 0) &&
1157                             (existing_cunk <= 0 ||
1158                              ((existing_serial + 1) & 3) == new_serial)) {
1159                                 /* Forward scanning.
1160                                  * Use new
1161                                  * Delete the old one and drop through to
1162                                  * update the tnode
1163                                  */
1164                                 yaffs_chunk_del(dev, existing_cunk, 1,
1165                                                 __LINE__);
1166                         } else {
1167                                 /* Backward scanning or we want to use the
1168                                  * existing one
1169                                  * Delete the new one and return early so that
1170                                  * the tnode isn't changed
1171                                  */
1172                                 yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
1173                                 return YAFFS_OK;
1174                         }
1175                 }
1176
1177         }
1178
1179         if (existing_cunk == 0)
1180                 in->n_data_chunks++;
1181
1182         yaffs_load_tnode_0(dev, tn, inode_chunk, nand_chunk);
1183
1184         return YAFFS_OK;
1185 }
1186
1187 static void yaffs_soft_del_chunk(struct yaffs_dev *dev, int chunk)
1188 {
1189         struct yaffs_block_info *the_block;
1190         unsigned block_no;
1191
1192         yaffs_trace(YAFFS_TRACE_DELETION, "soft delete chunk %d", chunk);
1193
1194         block_no = chunk / dev->param.chunks_per_block;
1195         the_block = yaffs_get_block_info(dev, block_no);
1196         if (the_block) {
1197                 the_block->soft_del_pages++;
1198                 dev->n_free_chunks++;
1199                 yaffs2_update_oldest_dirty_seq(dev, block_no, the_block);
1200         }
1201 }
1202
1203 /* SoftDeleteWorker scans backwards through the tnode tree and soft deletes all
1204  * the chunks in the file.
1205  * All soft deleting does is increment the block's softdelete count and pulls
1206  * the chunk out of the tnode.
1207  * Thus, essentially this is the same as DeleteWorker except that the chunks
1208  * are soft deleted.
1209  */
1210
1211 static int yaffs_soft_del_worker(struct yaffs_obj *in, struct yaffs_tnode *tn,
1212                                  u32 level, int chunk_offset)
1213 {
1214         int i;
1215         int the_chunk;
1216         int all_done = 1;
1217         struct yaffs_dev *dev = in->my_dev;
1218
1219         if (!tn)
1220                 return 1;
1221
1222         if (level > 0) {
1223                 for (i = YAFFS_NTNODES_INTERNAL - 1;
1224                         all_done && i >= 0;
1225                         i--) {
1226                         if (tn->internal[i]) {
1227                                 all_done =
1228                                     yaffs_soft_del_worker(in,
1229                                         tn->internal[i],
1230                                         level - 1,
1231                                         (chunk_offset <<
1232                                         YAFFS_TNODES_INTERNAL_BITS)
1233                                         + i);
1234                                 if (all_done) {
1235                                         yaffs_free_tnode(dev,
1236                                                 tn->internal[i]);
1237                                         tn->internal[i] = NULL;
1238                                 } else {
1239                                         /* Can this happen? */
1240                                 }
1241                         }
1242                 }
1243                 return (all_done) ? 1 : 0;
1244         }
1245
1246         /* level 0 */
1247          for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0; i--) {
1248                 the_chunk = yaffs_get_group_base(dev, tn, i);
1249                 if (the_chunk) {
1250                         yaffs_soft_del_chunk(dev, the_chunk);
1251                         yaffs_load_tnode_0(dev, tn, i, 0);
1252                 }
1253         }
1254         return 1;
1255 }
1256
1257 static void yaffs_remove_obj_from_dir(struct yaffs_obj *obj)
1258 {
1259         struct yaffs_dev *dev = obj->my_dev;
1260         struct yaffs_obj *parent;
1261
1262         yaffs_verify_obj_in_dir(obj);
1263         parent = obj->parent;
1264
1265         yaffs_verify_dir(parent);
1266
1267         if (dev && dev->param.remove_obj_fn)
1268                 dev->param.remove_obj_fn(obj);
1269
1270         list_del_init(&obj->siblings);
1271         obj->parent = NULL;
1272
1273         yaffs_verify_dir(parent);
1274 }
1275
1276 void yaffs_add_obj_to_dir(struct yaffs_obj *directory, struct yaffs_obj *obj)
1277 {
1278         if (!directory) {
1279                 yaffs_trace(YAFFS_TRACE_ALWAYS,
1280                         "tragedy: Trying to add an object to a null pointer directory"
1281                         );
1282                 BUG();
1283                 return;
1284         }
1285         if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
1286                 yaffs_trace(YAFFS_TRACE_ALWAYS,
1287                         "tragedy: Trying to add an object to a non-directory"
1288                         );
1289                 BUG();
1290         }
1291
1292         if (obj->siblings.prev == NULL) {
1293                 /* Not initialised */
1294                 BUG();
1295         }
1296
1297         yaffs_verify_dir(directory);
1298
1299         yaffs_remove_obj_from_dir(obj);
1300
1301         /* Now add it */
1302         list_add(&obj->siblings, &directory->variant.dir_variant.children);
1303         obj->parent = directory;
1304
1305         if (directory == obj->my_dev->unlinked_dir
1306             || directory == obj->my_dev->del_dir) {
1307                 obj->unlinked = 1;
1308                 obj->my_dev->n_unlinked_files++;
1309                 obj->rename_allowed = 0;
1310         }
1311
1312         yaffs_verify_dir(directory);
1313         yaffs_verify_obj_in_dir(obj);
1314 }
1315
1316 static int yaffs_change_obj_name(struct yaffs_obj *obj,
1317                                  struct yaffs_obj *new_dir,
1318                                  const YCHAR *new_name, int force, int shadows)
1319 {
1320         int unlink_op;
1321         int del_op;
1322         struct yaffs_obj *existing_target;
1323
1324         if (new_dir == NULL)
1325                 new_dir = obj->parent;  /* use the old directory */
1326
1327         if (new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
1328                 yaffs_trace(YAFFS_TRACE_ALWAYS,
1329                         "tragedy: yaffs_change_obj_name: new_dir is not a directory"
1330                         );
1331                 BUG();
1332         }
1333
1334         unlink_op = (new_dir == obj->my_dev->unlinked_dir);
1335         del_op = (new_dir == obj->my_dev->del_dir);
1336
1337         existing_target = yaffs_find_by_name(new_dir, new_name);
1338
1339         /* If the object is a file going into the unlinked directory,
1340          *   then it is OK to just stuff it in since duplicate names are OK.
1341          *   else only proceed if the new name does not exist and we're putting
1342          *   it into a directory.
1343          */
1344         if (!(unlink_op || del_op || force ||
1345               shadows > 0 || !existing_target) ||
1346               new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
1347                 return YAFFS_FAIL;
1348
1349         yaffs_set_obj_name(obj, new_name);
1350         obj->dirty = 1;
1351         yaffs_add_obj_to_dir(new_dir, obj);
1352
1353         if (unlink_op)
1354                 obj->unlinked = 1;
1355
1356         /* If it is a deletion then we mark it as a shrink for gc  */
1357         if (yaffs_update_oh(obj, new_name, 0, del_op, shadows, NULL) >= 0)
1358                 return YAFFS_OK;
1359
1360         return YAFFS_FAIL;
1361 }
1362
1363 /*------------------------ Short Operations Cache ------------------------------
1364  *   In many situations where there is no high level buffering  a lot of
1365  *   reads might be short sequential reads, and a lot of writes may be short
1366  *   sequential writes. eg. scanning/writing a jpeg file.
1367  *   In these cases, a short read/write cache can provide a huge perfomance
1368  *   benefit with dumb-as-a-rock code.
1369  *   In Linux, the page cache provides read buffering and the short op cache
1370  *   provides write buffering.
1371  *
1372  *   There are a small number (~10) of cache chunks per device so that we don't
1373  *   need a very intelligent search.
1374  */
1375
1376 static int yaffs_obj_cache_dirty(struct yaffs_obj *obj)
1377 {
1378         struct yaffs_dev *dev = obj->my_dev;
1379         int i;
1380         struct yaffs_cache *cache;
1381         int n_caches = obj->my_dev->param.n_caches;
1382
1383         for (i = 0; i < n_caches; i++) {
1384                 cache = &dev->cache[i];
1385                 if (cache->object == obj && cache->dirty)
1386                         return 1;
1387         }
1388
1389         return 0;
1390 }
1391
1392 static void yaffs_flush_file_cache(struct yaffs_obj *obj)
1393 {
1394         struct yaffs_dev *dev = obj->my_dev;
1395         int lowest = -99;       /* Stop compiler whining. */
1396         int i;
1397         struct yaffs_cache *cache;
1398         int chunk_written = 0;
1399         int n_caches = obj->my_dev->param.n_caches;
1400
1401         if (n_caches < 1)
1402                 return;
1403         do {
1404                 cache = NULL;
1405
1406                 /* Find the lowest dirty chunk for this object */
1407                 for (i = 0; i < n_caches; i++) {
1408                         if (dev->cache[i].object == obj &&
1409                             dev->cache[i].dirty) {
1410                                 if (!cache ||
1411                                     dev->cache[i].chunk_id < lowest) {
1412                                         cache = &dev->cache[i];
1413                                         lowest = cache->chunk_id;
1414                                 }
1415                         }
1416                 }
1417
1418                 if (cache && !cache->locked) {
1419                         /* Write it out and free it up */
1420                         chunk_written =
1421                             yaffs_wr_data_obj(cache->object,
1422                                               cache->chunk_id,
1423                                               cache->data,
1424                                               cache->n_bytes, 1);
1425                         cache->dirty = 0;
1426                         cache->object = NULL;
1427                 }
1428         } while (cache && chunk_written > 0);
1429
1430         if (cache)
1431                 /* Hoosterman, disk full while writing cache out. */
1432                 yaffs_trace(YAFFS_TRACE_ERROR,
1433                         "yaffs tragedy: no space during cache write");
1434 }
1435
1436 /*yaffs_flush_whole_cache(dev)
1437  *
1438  *
1439  */
1440
1441 void yaffs_flush_whole_cache(struct yaffs_dev *dev)
1442 {
1443         struct yaffs_obj *obj;
1444         int n_caches = dev->param.n_caches;
1445         int i;
1446
1447         /* Find a dirty object in the cache and flush it...
1448          * until there are no further dirty objects.
1449          */
1450         do {
1451                 obj = NULL;
1452                 for (i = 0; i < n_caches && !obj; i++) {
1453                         if (dev->cache[i].object && dev->cache[i].dirty)
1454                                 obj = dev->cache[i].object;
1455                 }
1456                 if (obj)
1457                         yaffs_flush_file_cache(obj);
1458         } while (obj);
1459
1460 }
1461
1462 /* Grab us a cache chunk for use.
1463  * First look for an empty one.
1464  * Then look for the least recently used non-dirty one.
1465  * Then look for the least recently used dirty one...., flush and look again.
1466  */
1467 static struct yaffs_cache *yaffs_grab_chunk_worker(struct yaffs_dev *dev)
1468 {
1469         int i;
1470
1471         if (dev->param.n_caches > 0) {
1472                 for (i = 0; i < dev->param.n_caches; i++) {
1473                         if (!dev->cache[i].object)
1474                                 return &dev->cache[i];
1475                 }
1476         }
1477         return NULL;
1478 }
1479
1480 static struct yaffs_cache *yaffs_grab_chunk_cache(struct yaffs_dev *dev)
1481 {
1482         struct yaffs_cache *cache;
1483         struct yaffs_obj *the_obj;
1484         int usage;
1485         int i;
1486
1487         if (dev->param.n_caches < 1)
1488                 return NULL;
1489
1490         /* Try find a non-dirty one... */
1491
1492         cache = yaffs_grab_chunk_worker(dev);
1493
1494         if (!cache) {
1495                 /* They were all dirty, find the LRU object and flush
1496                  * its cache, then  find again.
1497                  * NB what's here is not very accurate,
1498                  * we actually flush the object with the LRU chunk.
1499                  */
1500
1501                 /* With locking we can't assume we can use entry zero,
1502                  * Set the_obj to a valid pointer for Coverity. */
1503                 the_obj = dev->cache[0].object;
1504                 usage = -1;
1505                 cache = NULL;
1506
1507                 for (i = 0; i < dev->param.n_caches; i++) {
1508                         if (dev->cache[i].object &&
1509                             !dev->cache[i].locked &&
1510                             (dev->cache[i].last_use < usage ||
1511                             !cache)) {
1512                                 usage = dev->cache[i].last_use;
1513                                 the_obj = dev->cache[i].object;
1514                                 cache = &dev->cache[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 =
1959                                                 yaffs_max_file_size(dev);
1960                 the_obj->variant.file_variant.top_level = 0;
1961                 the_obj->variant.file_variant.top = tn;
1962                 break;
1963         case YAFFS_OBJECT_TYPE_DIRECTORY:
1964                 INIT_LIST_HEAD(&the_obj->variant.dir_variant.children);
1965                 INIT_LIST_HEAD(&the_obj->variant.dir_variant.dirty);
1966                 break;
1967         case YAFFS_OBJECT_TYPE_SYMLINK:
1968         case YAFFS_OBJECT_TYPE_HARDLINK:
1969         case YAFFS_OBJECT_TYPE_SPECIAL:
1970                 /* No action required */
1971                 break;
1972         case YAFFS_OBJECT_TYPE_UNKNOWN:
1973                 /* todo this should not happen */
1974                 break;
1975         }
1976         return the_obj;
1977 }
1978
1979 static struct yaffs_obj *yaffs_create_fake_dir(struct yaffs_dev *dev,
1980                                                int number, u32 mode)
1981 {
1982
1983         struct yaffs_obj *obj =
1984             yaffs_new_obj(dev, number, YAFFS_OBJECT_TYPE_DIRECTORY);
1985
1986         if (!obj)
1987                 return NULL;
1988
1989         obj->fake = 1;  /* it is fake so it might not use NAND */
1990         obj->rename_allowed = 0;
1991         obj->unlink_allowed = 0;
1992         obj->deleted = 0;
1993         obj->unlinked = 0;
1994         obj->yst_mode = mode;
1995         obj->my_dev = dev;
1996         obj->hdr_chunk = 0;     /* Not a valid chunk. */
1997         return obj;
1998
1999 }
2000
2001
2002 static void yaffs_init_tnodes_and_objs(struct yaffs_dev *dev)
2003 {
2004         int i;
2005
2006         dev->n_obj = 0;
2007         dev->n_tnodes = 0;
2008         yaffs_init_raw_tnodes_and_objs(dev);
2009
2010         for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
2011                 INIT_LIST_HEAD(&dev->obj_bucket[i].list);
2012                 dev->obj_bucket[i].count = 0;
2013         }
2014 }
2015
2016 struct yaffs_obj *yaffs_find_or_create_by_number(struct yaffs_dev *dev,
2017                                                  int number,
2018                                                  enum yaffs_obj_type type)
2019 {
2020         struct yaffs_obj *the_obj = NULL;
2021
2022         if (number > 0)
2023                 the_obj = yaffs_find_by_number(dev, number);
2024
2025         if (!the_obj)
2026                 the_obj = yaffs_new_obj(dev, number, type);
2027
2028         return the_obj;
2029
2030 }
2031
2032 YCHAR *yaffs_clone_str(const YCHAR *str)
2033 {
2034         YCHAR *new_str = NULL;
2035         int len;
2036
2037         if (!str)
2038                 str = _Y("");
2039
2040         len = yaffs_strnlen(str, YAFFS_MAX_ALIAS_LENGTH);
2041         new_str = kmalloc((len + 1) * sizeof(YCHAR), GFP_NOFS);
2042         if (new_str) {
2043                 yaffs_strncpy(new_str, str, len);
2044                 new_str[len] = 0;
2045         }
2046         return new_str;
2047
2048 }
2049 /*
2050  *yaffs_update_parent() handles fixing a directories mtime and ctime when a new
2051  * link (ie. name) is created or deleted in the directory.
2052  *
2053  * ie.
2054  *   create dir/a : update dir's mtime/ctime
2055  *   rm dir/a:   update dir's mtime/ctime
2056  *   modify dir/a: don't update dir's mtimme/ctime
2057  *
2058  * This can be handled immediately or defered. Defering helps reduce the number
2059  * of updates when many files in a directory are changed within a brief period.
2060  *
2061  * If the directory updating is defered then yaffs_update_dirty_dirs must be
2062  * called periodically.
2063  */
2064
2065 static void yaffs_update_parent(struct yaffs_obj *obj)
2066 {
2067         struct yaffs_dev *dev;
2068
2069         if (!obj)
2070                 return;
2071         dev = obj->my_dev;
2072         obj->dirty = 1;
2073         yaffs_load_current_time(obj, 0, 1);
2074         if (dev->param.defered_dir_update) {
2075                 struct list_head *link = &obj->variant.dir_variant.dirty;
2076
2077                 if (list_empty(link)) {
2078                         list_add(link, &dev->dirty_dirs);
2079                         yaffs_trace(YAFFS_TRACE_BACKGROUND,
2080                           "Added object %d to dirty directories",
2081                            obj->obj_id);
2082                 }
2083
2084         } else {
2085                 yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
2086         }
2087 }
2088
2089 void yaffs_update_dirty_dirs(struct yaffs_dev *dev)
2090 {
2091         struct list_head *link;
2092         struct yaffs_obj *obj;
2093         struct yaffs_dir_var *d_s;
2094         union yaffs_obj_var *o_v;
2095
2096         yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update dirty directories");
2097
2098         while (!list_empty(&dev->dirty_dirs)) {
2099                 link = dev->dirty_dirs.next;
2100                 list_del_init(link);
2101
2102                 d_s = list_entry(link, struct yaffs_dir_var, dirty);
2103                 o_v = list_entry(d_s, union yaffs_obj_var, dir_variant);
2104                 obj = list_entry(o_v, struct yaffs_obj, variant);
2105
2106                 yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update directory %d",
2107                         obj->obj_id);
2108
2109                 if (obj->dirty)
2110                         yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
2111         }
2112 }
2113
2114 /*
2115  * Mknod (create) a new object.
2116  * equiv_obj only has meaning for a hard link;
2117  * alias_str only has meaning for a symlink.
2118  * rdev only has meaning for devices (a subset of special objects)
2119  */
2120
2121 static struct yaffs_obj *yaffs_create_obj(enum yaffs_obj_type type,
2122                                           struct yaffs_obj *parent,
2123                                           const YCHAR *name,
2124                                           u32 mode,
2125                                           u32 uid,
2126                                           u32 gid,
2127                                           struct yaffs_obj *equiv_obj,
2128                                           const YCHAR *alias_str, u32 rdev)
2129 {
2130         struct yaffs_obj *in;
2131         YCHAR *str = NULL;
2132         struct yaffs_dev *dev = parent->my_dev;
2133
2134         /* Check if the entry exists.
2135          * If it does then fail the call since we don't want a dup. */
2136         if (yaffs_find_by_name(parent, name))
2137                 return NULL;
2138
2139         if (type == YAFFS_OBJECT_TYPE_SYMLINK) {
2140                 str = yaffs_clone_str(alias_str);
2141                 if (!str)
2142                         return NULL;
2143         }
2144
2145         in = yaffs_new_obj(dev, -1, type);
2146
2147         if (!in) {
2148                 kfree(str);
2149                 return NULL;
2150         }
2151
2152         in->hdr_chunk = 0;
2153         in->valid = 1;
2154         in->variant_type = type;
2155
2156         in->yst_mode = mode;
2157
2158         yaffs_attribs_init(in, gid, uid, rdev);
2159
2160         in->n_data_chunks = 0;
2161
2162         yaffs_set_obj_name(in, name);
2163         in->dirty = 1;
2164
2165         yaffs_add_obj_to_dir(parent, in);
2166
2167         in->my_dev = parent->my_dev;
2168
2169         switch (type) {
2170         case YAFFS_OBJECT_TYPE_SYMLINK:
2171                 in->variant.symlink_variant.alias = str;
2172                 break;
2173         case YAFFS_OBJECT_TYPE_HARDLINK:
2174                 in->variant.hardlink_variant.equiv_obj = equiv_obj;
2175                 in->variant.hardlink_variant.equiv_id = equiv_obj->obj_id;
2176                 list_add(&in->hard_links, &equiv_obj->hard_links);
2177                 break;
2178         case YAFFS_OBJECT_TYPE_FILE:
2179         case YAFFS_OBJECT_TYPE_DIRECTORY:
2180         case YAFFS_OBJECT_TYPE_SPECIAL:
2181         case YAFFS_OBJECT_TYPE_UNKNOWN:
2182                 /* do nothing */
2183                 break;
2184         }
2185
2186         if (yaffs_update_oh(in, name, 0, 0, 0, NULL) < 0) {
2187                 /* Could not create the object header, fail */
2188                 yaffs_del_obj(in);
2189                 in = NULL;
2190         }
2191
2192         if (in)
2193                 yaffs_update_parent(parent);
2194
2195         return in;
2196 }
2197
2198 struct yaffs_obj *yaffs_create_file(struct yaffs_obj *parent,
2199                                     const YCHAR *name, u32 mode, u32 uid,
2200                                     u32 gid)
2201 {
2202         return yaffs_create_obj(YAFFS_OBJECT_TYPE_FILE, parent, name, mode,
2203                                 uid, gid, NULL, NULL, 0);
2204 }
2205
2206 struct yaffs_obj *yaffs_create_dir(struct yaffs_obj *parent, const YCHAR *name,
2207                                    u32 mode, u32 uid, u32 gid)
2208 {
2209         return yaffs_create_obj(YAFFS_OBJECT_TYPE_DIRECTORY, parent, name,
2210                                 mode, uid, gid, NULL, NULL, 0);
2211 }
2212
2213 struct yaffs_obj *yaffs_create_special(struct yaffs_obj *parent,
2214                                        const YCHAR *name, u32 mode, u32 uid,
2215                                        u32 gid, u32 rdev)
2216 {
2217         return yaffs_create_obj(YAFFS_OBJECT_TYPE_SPECIAL, parent, name, mode,
2218                                 uid, gid, NULL, NULL, rdev);
2219 }
2220
2221 struct yaffs_obj *yaffs_create_symlink(struct yaffs_obj *parent,
2222                                        const YCHAR *name, u32 mode, u32 uid,
2223                                        u32 gid, const YCHAR *alias)
2224 {
2225         return yaffs_create_obj(YAFFS_OBJECT_TYPE_SYMLINK, parent, name, mode,
2226                                 uid, gid, NULL, alias, 0);
2227 }
2228
2229 /* yaffs_link_obj returns the object id of the equivalent object.*/
2230 struct yaffs_obj *yaffs_link_obj(struct yaffs_obj *parent, const YCHAR * name,
2231                                  struct yaffs_obj *equiv_obj)
2232 {
2233         /* Get the real object in case we were fed a hard link obj */
2234         equiv_obj = yaffs_get_equivalent_obj(equiv_obj);
2235
2236         if (yaffs_create_obj(YAFFS_OBJECT_TYPE_HARDLINK,
2237                         parent, name, 0, 0, 0,
2238                         equiv_obj, NULL, 0))
2239                 return equiv_obj;
2240
2241         return NULL;
2242
2243 }
2244
2245
2246
2247 /*---------------------- Block Management and Page Allocation -------------*/
2248
2249 static void yaffs_deinit_blocks(struct yaffs_dev *dev)
2250 {
2251         if (dev->block_info_alt && dev->block_info)
2252                 vfree(dev->block_info);
2253         else
2254                 kfree(dev->block_info);
2255
2256         dev->block_info_alt = 0;
2257
2258         dev->block_info = NULL;
2259
2260         if (dev->chunk_bits_alt && dev->chunk_bits)
2261                 vfree(dev->chunk_bits);
2262         else
2263                 kfree(dev->chunk_bits);
2264         dev->chunk_bits_alt = 0;
2265         dev->chunk_bits = NULL;
2266 }
2267
2268 static int yaffs_init_blocks(struct yaffs_dev *dev)
2269 {
2270         int n_blocks = dev->internal_end_block - dev->internal_start_block + 1;
2271
2272         dev->block_info = NULL;
2273         dev->chunk_bits = NULL;
2274         dev->alloc_block = -1;  /* force it to get a new one */
2275
2276         /* If the first allocation strategy fails, thry the alternate one */
2277         dev->block_info =
2278                 kmalloc(n_blocks * sizeof(struct yaffs_block_info), GFP_NOFS);
2279         if (!dev->block_info) {
2280                 dev->block_info =
2281                     vmalloc(n_blocks * sizeof(struct yaffs_block_info));
2282                 dev->block_info_alt = 1;
2283         } else {
2284                 dev->block_info_alt = 0;
2285         }
2286
2287         if (!dev->block_info)
2288                 goto alloc_error;
2289
2290         /* Set up dynamic blockinfo stuff. Round up bytes. */
2291         dev->chunk_bit_stride = (dev->param.chunks_per_block + 7) / 8;
2292         dev->chunk_bits =
2293                 kmalloc(dev->chunk_bit_stride * n_blocks, GFP_NOFS);
2294         if (!dev->chunk_bits) {
2295                 dev->chunk_bits =
2296                     vmalloc(dev->chunk_bit_stride * n_blocks);
2297                 dev->chunk_bits_alt = 1;
2298         } else {
2299                 dev->chunk_bits_alt = 0;
2300         }
2301         if (!dev->chunk_bits)
2302                 goto alloc_error;
2303
2304
2305         memset(dev->block_info, 0, n_blocks * sizeof(struct yaffs_block_info));
2306         memset(dev->chunk_bits, 0, dev->chunk_bit_stride * n_blocks);
2307         return YAFFS_OK;
2308
2309 alloc_error:
2310         yaffs_deinit_blocks(dev);
2311         return YAFFS_FAIL;
2312 }
2313
2314
2315 void yaffs_block_became_dirty(struct yaffs_dev *dev, int block_no)
2316 {
2317         struct yaffs_block_info *bi = yaffs_get_block_info(dev, block_no);
2318         int erased_ok = 0;
2319         int i;
2320
2321         /* If the block is still healthy erase it and mark as clean.
2322          * If the block has had a data failure, then retire it.
2323          */
2324
2325         yaffs_trace(YAFFS_TRACE_GC | YAFFS_TRACE_ERASE,
2326                 "yaffs_block_became_dirty block %d state %d %s",
2327                 block_no, bi->block_state,
2328                 (bi->needs_retiring) ? "needs retiring" : "");
2329
2330         yaffs2_clear_oldest_dirty_seq(dev, bi);
2331
2332         bi->block_state = YAFFS_BLOCK_STATE_DIRTY;
2333
2334         /* If this is the block being garbage collected then stop gc'ing */
2335         if (block_no == dev->gc_block)
2336                 dev->gc_block = 0;
2337
2338         /* If this block is currently the best candidate for gc
2339          * then drop as a candidate */
2340         if (block_no == dev->gc_dirtiest) {
2341                 dev->gc_dirtiest = 0;
2342                 dev->gc_pages_in_use = 0;
2343         }
2344
2345         if (!bi->needs_retiring) {
2346                 yaffs2_checkpt_invalidate(dev);
2347                 erased_ok = yaffs_erase_block(dev, block_no);
2348                 if (!erased_ok) {
2349                         dev->n_erase_failures++;
2350                         yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2351                           "**>> Erasure failed %d", block_no);
2352                 }
2353         }
2354
2355         /* Verify erasure if needed */
2356         if (erased_ok &&
2357             ((yaffs_trace_mask & YAFFS_TRACE_ERASE) ||
2358              !yaffs_skip_verification(dev))) {
2359                 for (i = 0; i < dev->param.chunks_per_block; i++) {
2360                         if (!yaffs_check_chunk_erased(dev,
2361                                 block_no * dev->param.chunks_per_block + i)) {
2362                                 yaffs_trace(YAFFS_TRACE_ERROR,
2363                                         ">>Block %d erasure supposedly OK, but chunk %d not erased",
2364                                         block_no, i);
2365                         }
2366                 }
2367         }
2368
2369         if (!erased_ok) {
2370                 /* We lost a block of free space */
2371                 dev->n_free_chunks -= dev->param.chunks_per_block;
2372                 yaffs_retire_block(dev, block_no);
2373                 yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2374                         "**>> Block %d retired", block_no);
2375                 return;
2376         }
2377
2378         /* Clean it up... */
2379         bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
2380         bi->seq_number = 0;
2381         dev->n_erased_blocks++;
2382         bi->pages_in_use = 0;
2383         bi->soft_del_pages = 0;
2384         bi->has_shrink_hdr = 0;
2385         bi->skip_erased_check = 1;      /* Clean, so no need to check */
2386         bi->gc_prioritise = 0;
2387         bi->has_summary = 0;
2388
2389         yaffs_clear_chunk_bits(dev, block_no);
2390
2391         yaffs_trace(YAFFS_TRACE_ERASE, "Erased block %d", block_no);
2392 }
2393
2394 static inline int yaffs_gc_process_chunk(struct yaffs_dev *dev,
2395                                         struct yaffs_block_info *bi,
2396                                         int old_chunk, u8 *buffer)
2397 {
2398         int new_chunk;
2399         int mark_flash = 1;
2400         struct yaffs_ext_tags tags;
2401         struct yaffs_obj *object;
2402         int matching_chunk;
2403         int ret_val = YAFFS_OK;
2404
2405         memset(&tags, 0, sizeof(tags));
2406         yaffs_rd_chunk_tags_nand(dev, old_chunk,
2407                                  buffer, &tags);
2408         object = yaffs_find_by_number(dev, tags.obj_id);
2409
2410         yaffs_trace(YAFFS_TRACE_GC_DETAIL,
2411                 "Collecting chunk in block %d, %d %d %d ",
2412                 dev->gc_chunk, tags.obj_id,
2413                 tags.chunk_id, tags.n_bytes);
2414
2415         if (object && !yaffs_skip_verification(dev)) {
2416                 if (tags.chunk_id == 0)
2417                         matching_chunk =
2418                             object->hdr_chunk;
2419                 else if (object->soft_del)
2420                         /* Defeat the test */
2421                         matching_chunk = old_chunk;
2422                 else
2423                         matching_chunk =
2424                             yaffs_find_chunk_in_file
2425                             (object, tags.chunk_id,
2426                              NULL);
2427
2428                 if (old_chunk != matching_chunk)
2429                         yaffs_trace(YAFFS_TRACE_ERROR,
2430                                 "gc: page in gc mismatch: %d %d %d %d",
2431                                 old_chunk,
2432                                 matching_chunk,
2433                                 tags.obj_id,
2434                                 tags.chunk_id);
2435         }
2436
2437         if (!object) {
2438                 yaffs_trace(YAFFS_TRACE_ERROR,
2439                         "page %d in gc has no object: %d %d %d ",
2440                         old_chunk,
2441                         tags.obj_id, tags.chunk_id,
2442                         tags.n_bytes);
2443         }
2444
2445         if (object &&
2446             object->deleted &&
2447             object->soft_del && tags.chunk_id != 0) {
2448                 /* Data chunk in a soft deleted file,
2449                  * throw it away.
2450                  * It's a soft deleted data chunk,
2451                  * No need to copy this, just forget
2452                  * about it and fix up the object.
2453                  */
2454
2455                 /* Free chunks already includes
2456                  * softdeleted chunks, how ever this
2457                  * chunk is going to soon be really
2458                  * deleted which will increment free
2459                  * chunks. We have to decrement free
2460                  * chunks so this works out properly.
2461                  */
2462                 dev->n_free_chunks--;
2463                 bi->soft_del_pages--;
2464
2465                 object->n_data_chunks--;
2466                 if (object->n_data_chunks <= 0) {
2467                         /* remeber to clean up obj */
2468                         dev->gc_cleanup_list[dev->n_clean_ups] = tags.obj_id;
2469                         dev->n_clean_ups++;
2470                 }
2471                 mark_flash = 0;
2472         } else if (object) {
2473                 /* It's either a data chunk in a live
2474                  * file or an ObjectHeader, so we're
2475                  * interested in it.
2476                  * NB Need to keep the ObjectHeaders of
2477                  * deleted files until the whole file
2478                  * has been deleted off
2479                  */
2480                 tags.serial_number++;
2481                 dev->n_gc_copies++;
2482
2483                 if (tags.chunk_id == 0) {
2484                         /* It is an object Id,
2485                          * We need to nuke the
2486                          * shrinkheader flags since its
2487                          * work is done.
2488                          * Also need to clean up
2489                          * shadowing.
2490                          */
2491                         struct yaffs_obj_hdr *oh;
2492                         oh = (struct yaffs_obj_hdr *) buffer;
2493
2494                         oh->is_shrink = 0;
2495                         tags.extra_is_shrink = 0;
2496                         oh->shadows_obj = 0;
2497                         oh->inband_shadowed_obj_id = 0;
2498                         tags.extra_shadows = 0;
2499
2500                         /* Update file size */
2501                         if (object->variant_type == YAFFS_OBJECT_TYPE_FILE) {
2502                                 yaffs_oh_size_load(oh,
2503                                     object->variant.file_variant.file_size);
2504                                 tags.extra_file_size =
2505                                     object->variant.file_variant.file_size;
2506                         }
2507
2508                         yaffs_verify_oh(object, oh, &tags, 1);
2509                         new_chunk =
2510                             yaffs_write_new_chunk(dev, (u8 *) oh, &tags, 1);
2511                 } else {
2512                         new_chunk =
2513                             yaffs_write_new_chunk(dev, buffer, &tags, 1);
2514                 }
2515
2516                 if (new_chunk < 0) {
2517                         ret_val = YAFFS_FAIL;
2518                 } else {
2519
2520                         /* Now fix up the Tnodes etc. */
2521
2522                         if (tags.chunk_id == 0) {
2523                                 /* It's a header */
2524                                 object->hdr_chunk = new_chunk;
2525                                 object->serial = tags.serial_number;
2526                         } else {
2527                                 /* It's a data chunk */
2528                                 yaffs_put_chunk_in_file(object, tags.chunk_id,
2529                                                         new_chunk, 0);
2530                         }
2531                 }
2532         }
2533         if (ret_val == YAFFS_OK)
2534                 yaffs_chunk_del(dev, old_chunk, mark_flash, __LINE__);
2535         return ret_val;
2536 }
2537
2538 static int yaffs_gc_block(struct yaffs_dev *dev, int block, int whole_block)
2539 {
2540         int old_chunk;
2541         int ret_val = YAFFS_OK;
2542         int i;
2543         int is_checkpt_block;
2544         int max_copies;
2545         int chunks_before = yaffs_get_erased_chunks(dev);
2546         int chunks_after;
2547         struct yaffs_block_info *bi = yaffs_get_block_info(dev, block);
2548
2549         is_checkpt_block = (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT);
2550
2551         yaffs_trace(YAFFS_TRACE_TRACING,
2552                 "Collecting block %d, in use %d, shrink %d, whole_block %d",
2553                 block, bi->pages_in_use, bi->has_shrink_hdr,
2554                 whole_block);
2555
2556         /*yaffs_verify_free_chunks(dev); */
2557
2558         if (bi->block_state == YAFFS_BLOCK_STATE_FULL)
2559                 bi->block_state = YAFFS_BLOCK_STATE_COLLECTING;
2560
2561         bi->has_shrink_hdr = 0; /* clear the flag so that the block can erase */
2562
2563         dev->gc_disable = 1;
2564
2565         yaffs_summary_gc(dev, block);
2566
2567         if (is_checkpt_block || !yaffs_still_some_chunks(dev, block)) {
2568                 yaffs_trace(YAFFS_TRACE_TRACING,
2569                         "Collecting block %d that has no chunks in use",
2570                         block);
2571                 yaffs_block_became_dirty(dev, block);
2572         } else {
2573
2574                 u8 *buffer = yaffs_get_temp_buffer(dev);
2575
2576                 yaffs_verify_blk(dev, bi, block);
2577
2578                 max_copies = (whole_block) ? dev->param.chunks_per_block : 5;
2579                 old_chunk = block * dev->param.chunks_per_block + dev->gc_chunk;
2580
2581                 for (/* init already done */ ;
2582                      ret_val == YAFFS_OK &&
2583                      dev->gc_chunk < dev->param.chunks_per_block &&
2584                      (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) &&
2585                      max_copies > 0;
2586                      dev->gc_chunk++, old_chunk++) {
2587                         if (yaffs_check_chunk_bit(dev, block, dev->gc_chunk)) {
2588                                 /* Page is in use and might need to be copied */
2589                                 max_copies--;
2590                                 ret_val = yaffs_gc_process_chunk(dev, bi,
2591                                                         old_chunk, buffer);
2592                         }
2593                 }
2594                 yaffs_release_temp_buffer(dev, buffer);
2595         }
2596
2597         yaffs_verify_collected_blk(dev, bi, block);
2598
2599         if (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
2600                 /*
2601                  * The gc did not complete. Set block state back to FULL
2602                  * because checkpointing does not restore gc.
2603                  */
2604                 bi->block_state = YAFFS_BLOCK_STATE_FULL;
2605         } else {
2606                 /* The gc completed. */
2607                 /* Do any required cleanups */
2608                 for (i = 0; i < dev->n_clean_ups; i++) {
2609                         /* Time to delete the file too */
2610                         struct yaffs_obj *object =
2611                             yaffs_find_by_number(dev, dev->gc_cleanup_list[i]);
2612                         if (object) {
2613                                 yaffs_free_tnode(dev,
2614                                           object->variant.file_variant.top);
2615                                 object->variant.file_variant.top = NULL;
2616                                 yaffs_trace(YAFFS_TRACE_GC,
2617                                         "yaffs: About to finally delete object %d",
2618                                         object->obj_id);
2619                                 yaffs_generic_obj_del(object);
2620                                 object->my_dev->n_deleted_files--;
2621                         }
2622
2623                 }
2624                 chunks_after = yaffs_get_erased_chunks(dev);
2625                 if (chunks_before >= chunks_after)
2626                         yaffs_trace(YAFFS_TRACE_GC,
2627                                 "gc did not increase free chunks before %d after %d",
2628                                 chunks_before, chunks_after);
2629                 dev->gc_block = 0;
2630                 dev->gc_chunk = 0;
2631                 dev->n_clean_ups = 0;
2632         }
2633
2634         dev->gc_disable = 0;
2635
2636         return ret_val;
2637 }
2638
2639 /*
2640  * find_gc_block() selects the dirtiest block (or close enough)
2641  * for garbage collection.
2642  */
2643
2644 static unsigned yaffs_find_gc_block(struct yaffs_dev *dev,
2645                                     int aggressive, int background)
2646 {
2647         int i;
2648         int iterations;
2649         unsigned selected = 0;
2650         int prioritised = 0;
2651         int prioritised_exist = 0;
2652         struct yaffs_block_info *bi;
2653         int threshold;
2654
2655         /* First let's see if we need to grab a prioritised block */
2656         if (dev->has_pending_prioritised_gc && !aggressive) {
2657                 dev->gc_dirtiest = 0;
2658                 bi = dev->block_info;
2659                 for (i = dev->internal_start_block;
2660                      i <= dev->internal_end_block && !selected; i++) {
2661
2662                         if (bi->gc_prioritise) {
2663                                 prioritised_exist = 1;
2664                                 if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
2665                                     yaffs_block_ok_for_gc(dev, bi)) {
2666                                         selected = i;
2667                                         prioritised = 1;
2668                                 }
2669                         }
2670                         bi++;
2671                 }
2672
2673                 /*
2674                  * If there is a prioritised block and none was selected then
2675                  * this happened because there is at least one old dirty block
2676                  * gumming up the works. Let's gc the oldest dirty block.
2677                  */
2678
2679                 if (prioritised_exist &&
2680                     !selected && dev->oldest_dirty_block > 0)
2681                         selected = dev->oldest_dirty_block;
2682
2683                 if (!prioritised_exist) /* None found, so we can clear this */
2684                         dev->has_pending_prioritised_gc = 0;
2685         }
2686
2687         /* If we're doing aggressive GC then we are happy to take a less-dirty
2688          * block, and search harder.
2689          * else (leasurely gc), then we only bother to do this if the
2690          * block has only a few pages in use.
2691          */
2692
2693         if (!selected) {
2694                 int pages_used;
2695                 int n_blocks =
2696                     dev->internal_end_block - dev->internal_start_block + 1;
2697                 if (aggressive) {
2698                         threshold = dev->param.chunks_per_block;
2699                         iterations = n_blocks;
2700                 } else {
2701                         int max_threshold;
2702
2703                         if (background)
2704                                 max_threshold = dev->param.chunks_per_block / 2;
2705                         else
2706                                 max_threshold = dev->param.chunks_per_block / 8;
2707
2708                         if (max_threshold < YAFFS_GC_PASSIVE_THRESHOLD)
2709                                 max_threshold = YAFFS_GC_PASSIVE_THRESHOLD;
2710
2711                         threshold = background ? (dev->gc_not_done + 2) * 2 : 0;
2712                         if (threshold < YAFFS_GC_PASSIVE_THRESHOLD)
2713                                 threshold = YAFFS_GC_PASSIVE_THRESHOLD;
2714                         if (threshold > max_threshold)
2715                                 threshold = max_threshold;
2716
2717                         iterations = n_blocks / 16 + 1;
2718                         if (iterations > 100)
2719                                 iterations = 100;
2720                 }
2721
2722                 for (i = 0;
2723                      i < iterations &&
2724                      (dev->gc_dirtiest < 1 ||
2725                       dev->gc_pages_in_use > YAFFS_GC_GOOD_ENOUGH);
2726                      i++) {
2727                         dev->gc_block_finder++;
2728                         if (dev->gc_block_finder < dev->internal_start_block ||
2729                             dev->gc_block_finder > dev->internal_end_block)
2730                                 dev->gc_block_finder =
2731                                     dev->internal_start_block;
2732
2733                         bi = yaffs_get_block_info(dev, dev->gc_block_finder);
2734
2735                         pages_used = bi->pages_in_use - bi->soft_del_pages;
2736
2737                         if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
2738                             pages_used < dev->param.chunks_per_block &&
2739                             (dev->gc_dirtiest < 1 ||
2740                              pages_used < dev->gc_pages_in_use) &&
2741                             yaffs_block_ok_for_gc(dev, bi)) {
2742                                 dev->gc_dirtiest = dev->gc_block_finder;
2743                                 dev->gc_pages_in_use = pages_used;
2744                         }
2745                 }
2746
2747                 if (dev->gc_dirtiest > 0 && dev->gc_pages_in_use <= threshold)
2748                         selected = dev->gc_dirtiest;
2749         }
2750
2751         /*
2752          * If nothing has been selected for a while, try the oldest dirty
2753          * because that's gumming up the works.
2754          */
2755
2756         if (!selected && dev->param.is_yaffs2 &&
2757             dev->gc_not_done >= (background ? 10 : 20)) {
2758                 yaffs2_find_oldest_dirty_seq(dev);
2759                 if (dev->oldest_dirty_block > 0) {
2760                         selected = dev->oldest_dirty_block;
2761                         dev->gc_dirtiest = selected;
2762                         dev->oldest_dirty_gc_count++;
2763                         bi = yaffs_get_block_info(dev, selected);
2764                         dev->gc_pages_in_use =
2765                             bi->pages_in_use - bi->soft_del_pages;
2766                 } else {
2767                         dev->gc_not_done = 0;
2768                 }
2769         }
2770
2771         if (selected) {
2772                 yaffs_trace(YAFFS_TRACE_GC,
2773                         "GC Selected block %d with %d free, prioritised:%d",
2774                         selected,
2775                         dev->param.chunks_per_block - dev->gc_pages_in_use,
2776                         prioritised);
2777
2778                 dev->n_gc_blocks++;
2779                 if (background)
2780                         dev->bg_gcs++;
2781
2782                 dev->gc_dirtiest = 0;
2783                 dev->gc_pages_in_use = 0;
2784                 dev->gc_not_done = 0;
2785                 if (dev->refresh_skip > 0)
2786                         dev->refresh_skip--;
2787         } else {
2788                 dev->gc_not_done++;
2789                 yaffs_trace(YAFFS_TRACE_GC,
2790                         "GC none: finder %d skip %d threshold %d dirtiest %d using %d oldest %d%s",
2791                         dev->gc_block_finder, dev->gc_not_done, threshold,
2792                         dev->gc_dirtiest, dev->gc_pages_in_use,
2793                         dev->oldest_dirty_block, background ? " bg" : "");
2794         }
2795
2796         return selected;
2797 }
2798
2799 /* New garbage collector
2800  * If we're very low on erased blocks then we do aggressive garbage collection
2801  * otherwise we do "leasurely" garbage collection.
2802  * Aggressive gc looks further (whole array) and will accept less dirty blocks.
2803  * Passive gc only inspects smaller areas and only accepts more dirty blocks.
2804  *
2805  * The idea is to help clear out space in a more spread-out manner.
2806  * Dunno if it really does anything useful.
2807  */
2808 static int yaffs_check_gc(struct yaffs_dev *dev, int background)
2809 {
2810         int aggressive = 0;
2811         int gc_ok = YAFFS_OK;
2812         int max_tries = 0;
2813         int min_erased;
2814         int erased_chunks;
2815         int checkpt_block_adjust;
2816
2817         if (dev->param.gc_control && (dev->param.gc_control(dev) & 1) == 0)
2818                 return YAFFS_OK;
2819
2820         if (dev->gc_disable)
2821                 /* Bail out so we don't get recursive gc */
2822                 return YAFFS_OK;
2823
2824         /* This loop should pass the first time.
2825          * Only loops here if the collection does not increase space.
2826          */
2827
2828         do {
2829                 max_tries++;
2830
2831                 checkpt_block_adjust = yaffs_calc_checkpt_blocks_required(dev);
2832
2833                 min_erased =
2834                     dev->param.n_reserved_blocks + checkpt_block_adjust + 1;
2835                 erased_chunks =
2836                     dev->n_erased_blocks * dev->param.chunks_per_block;
2837
2838                 /* If we need a block soon then do aggressive gc. */
2839                 if (dev->n_erased_blocks < min_erased)
2840                         aggressive = 1;
2841                 else {
2842                         if (!background
2843                             && erased_chunks > (dev->n_free_chunks / 4))
2844                                 break;
2845
2846                         if (dev->gc_skip > 20)
2847                                 dev->gc_skip = 20;
2848                         if (erased_chunks < dev->n_free_chunks / 2 ||
2849                             dev->gc_skip < 1 || background)
2850                                 aggressive = 0;
2851                         else {
2852                                 dev->gc_skip--;
2853                                 break;
2854                         }
2855                 }
2856
2857                 dev->gc_skip = 5;
2858
2859                 /* If we don't already have a block being gc'd then see if we
2860                  * should start another */
2861
2862                 if (dev->gc_block < 1 && !aggressive) {
2863                         dev->gc_block = yaffs2_find_refresh_block(dev);
2864                         dev->gc_chunk = 0;
2865                         dev->n_clean_ups = 0;
2866                 }
2867                 if (dev->gc_block < 1) {
2868                         dev->gc_block =
2869                             yaffs_find_gc_block(dev, aggressive, background);
2870                         dev->gc_chunk = 0;
2871                         dev->n_clean_ups = 0;
2872                 }
2873
2874                 if (dev->gc_block > 0) {
2875                         dev->all_gcs++;
2876                         if (!aggressive)
2877                                 dev->passive_gc_count++;
2878
2879                         yaffs_trace(YAFFS_TRACE_GC,
2880                                 "yaffs: GC n_erased_blocks %d aggressive %d",
2881                                 dev->n_erased_blocks, aggressive);
2882
2883                         gc_ok = yaffs_gc_block(dev, dev->gc_block, aggressive);
2884                 }
2885
2886                 if (dev->n_erased_blocks < (dev->param.n_reserved_blocks) &&
2887                     dev->gc_block > 0) {
2888                         yaffs_trace(YAFFS_TRACE_GC,
2889                                 "yaffs: GC !!!no reclaim!!! n_erased_blocks %d after try %d block %d",
2890                                 dev->n_erased_blocks, max_tries,
2891                                 dev->gc_block);
2892                 }
2893         } while ((dev->n_erased_blocks < dev->param.n_reserved_blocks) &&
2894                  (dev->gc_block > 0) && (max_tries < 2));
2895
2896         return aggressive ? gc_ok : YAFFS_OK;
2897 }
2898
2899 /*
2900  * yaffs_bg_gc()
2901  * Garbage collects. Intended to be called from a background thread.
2902  * Returns non-zero if at least half the free chunks are erased.
2903  */
2904 int yaffs_bg_gc(struct yaffs_dev *dev, unsigned urgency)
2905 {
2906         int erased_chunks = dev->n_erased_blocks * dev->param.chunks_per_block;
2907
2908         yaffs_trace(YAFFS_TRACE_BACKGROUND, "Background gc %u", urgency);
2909
2910         yaffs_check_gc(dev, 1);
2911         return erased_chunks > dev->n_free_chunks / 2;
2912 }
2913
2914 /*-------------------- Data file manipulation -----------------*/
2915
2916 static int yaffs_rd_data_obj(struct yaffs_obj *in, int inode_chunk, u8 * buffer)
2917 {
2918         int nand_chunk = yaffs_find_chunk_in_file(in, inode_chunk, NULL);
2919
2920         if (nand_chunk >= 0)
2921                 return yaffs_rd_chunk_tags_nand(in->my_dev, nand_chunk,
2922                                                 buffer, NULL);
2923         else {
2924                 yaffs_trace(YAFFS_TRACE_NANDACCESS,
2925                         "Chunk %d not found zero instead",
2926                         nand_chunk);
2927                 /* get sane (zero) data if you read a hole */
2928                 memset(buffer, 0, in->my_dev->data_bytes_per_chunk);
2929                 return 0;
2930         }
2931
2932 }
2933
2934 void yaffs_chunk_del(struct yaffs_dev *dev, int chunk_id, int mark_flash,
2935                      int lyn)
2936 {
2937         int block;
2938         int page;
2939         struct yaffs_ext_tags tags;
2940         struct yaffs_block_info *bi;
2941
2942         if (chunk_id <= 0)
2943                 return;
2944
2945         dev->n_deletions++;
2946         block = chunk_id / dev->param.chunks_per_block;
2947         page = chunk_id % dev->param.chunks_per_block;
2948
2949         if (!yaffs_check_chunk_bit(dev, block, page))
2950                 yaffs_trace(YAFFS_TRACE_VERIFY,
2951                         "Deleting invalid chunk %d", chunk_id);
2952
2953         bi = yaffs_get_block_info(dev, block);
2954
2955         yaffs2_update_oldest_dirty_seq(dev, block, bi);
2956
2957         yaffs_trace(YAFFS_TRACE_DELETION,
2958                 "line %d delete of chunk %d",
2959                 lyn, chunk_id);
2960
2961         if (!dev->param.is_yaffs2 && mark_flash &&
2962             bi->block_state != YAFFS_BLOCK_STATE_COLLECTING) {
2963
2964                 memset(&tags, 0, sizeof(tags));
2965                 tags.is_deleted = 1;
2966                 yaffs_wr_chunk_tags_nand(dev, chunk_id, NULL, &tags);
2967                 yaffs_handle_chunk_update(dev, chunk_id, &tags);
2968         } else {
2969                 dev->n_unmarked_deletions++;
2970         }
2971
2972         /* Pull out of the management area.
2973          * If the whole block became dirty, this will kick off an erasure.
2974          */
2975         if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING ||
2976             bi->block_state == YAFFS_BLOCK_STATE_FULL ||
2977             bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCAN ||
2978             bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
2979                 dev->n_free_chunks++;
2980                 yaffs_clear_chunk_bit(dev, block, page);
2981                 bi->pages_in_use--;
2982
2983                 if (bi->pages_in_use == 0 &&
2984                     !bi->has_shrink_hdr &&
2985                     bi->block_state != YAFFS_BLOCK_STATE_ALLOCATING &&
2986                     bi->block_state != YAFFS_BLOCK_STATE_NEEDS_SCAN) {
2987                         yaffs_block_became_dirty(dev, block);
2988                 }
2989         }
2990 }
2991
2992 static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
2993                              const u8 *buffer, int n_bytes, int use_reserve)
2994 {
2995         /* Find old chunk Need to do this to get serial number
2996          * Write new one and patch into tree.
2997          * Invalidate old tags.
2998          */
2999
3000         int prev_chunk_id;
3001         struct yaffs_ext_tags prev_tags;
3002         int new_chunk_id;
3003         struct yaffs_ext_tags new_tags;
3004         struct yaffs_dev *dev = in->my_dev;
3005
3006         yaffs_check_gc(dev, 0);
3007
3008         /* Get the previous chunk at this location in the file if it exists.
3009          * If it does not exist then put a zero into the tree. This creates
3010          * the tnode now, rather than later when it is harder to clean up.
3011          */
3012         prev_chunk_id = yaffs_find_chunk_in_file(in, inode_chunk, &prev_tags);
3013         if (prev_chunk_id < 1 &&
3014             !yaffs_put_chunk_in_file(in, inode_chunk, 0, 0))
3015                 return 0;
3016
3017         /* Set up new tags */
3018         memset(&new_tags, 0, sizeof(new_tags));
3019
3020         new_tags.chunk_id = inode_chunk;
3021         new_tags.obj_id = in->obj_id;
3022         new_tags.serial_number =
3023             (prev_chunk_id > 0) ? prev_tags.serial_number + 1 : 1;
3024         new_tags.n_bytes = n_bytes;
3025
3026         if (n_bytes < 1 || n_bytes > dev->param.total_bytes_per_chunk) {
3027                 yaffs_trace(YAFFS_TRACE_ERROR,
3028                   "Writing %d bytes to chunk!!!!!!!!!",
3029                    n_bytes);
3030                 BUG();
3031         }
3032
3033         new_chunk_id =
3034             yaffs_write_new_chunk(dev, buffer, &new_tags, use_reserve);
3035
3036         if (new_chunk_id > 0) {
3037                 yaffs_put_chunk_in_file(in, inode_chunk, new_chunk_id, 0);
3038
3039                 if (prev_chunk_id > 0)
3040                         yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
3041
3042                 yaffs_verify_file_sane(in);
3043         }
3044         return new_chunk_id;
3045
3046 }
3047
3048
3049
3050 static int yaffs_do_xattrib_mod(struct yaffs_obj *obj, int set,
3051                                 const YCHAR *name, const void *value, int size,
3052                                 int flags)
3053 {
3054         struct yaffs_xattr_mod xmod;
3055         int result;
3056
3057         xmod.set = set;
3058         xmod.name = name;
3059         xmod.data = value;
3060         xmod.size = size;
3061         xmod.flags = flags;
3062         xmod.result = -ENOSPC;
3063
3064         result = yaffs_update_oh(obj, NULL, 0, 0, 0, &xmod);
3065
3066         if (result > 0)
3067                 return xmod.result;
3068         else
3069                 return -ENOSPC;
3070 }
3071
3072 static int yaffs_apply_xattrib_mod(struct yaffs_obj *obj, char *buffer,
3073                                    struct yaffs_xattr_mod *xmod)
3074 {
3075         int retval = 0;
3076         int x_offs = sizeof(struct yaffs_obj_hdr);
3077         struct yaffs_dev *dev = obj->my_dev;
3078         int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
3079         char *x_buffer = buffer + x_offs;
3080
3081         if (xmod->set)
3082                 retval =
3083                     nval_set(x_buffer, x_size, xmod->name, xmod->data,
3084                              xmod->size, xmod->flags);
3085         else
3086                 retval = nval_del(x_buffer, x_size, xmod->name);
3087
3088         obj->has_xattr = nval_hasvalues(x_buffer, x_size);
3089         obj->xattr_known = 1;
3090         xmod->result = retval;
3091
3092         return retval;
3093 }
3094
3095 static int yaffs_do_xattrib_fetch(struct yaffs_obj *obj, const YCHAR *name,
3096                                   void *value, int size)
3097 {
3098         char *buffer = NULL;
3099         int result;
3100         struct yaffs_ext_tags tags;
3101         struct yaffs_dev *dev = obj->my_dev;
3102         int x_offs = sizeof(struct yaffs_obj_hdr);
3103         int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
3104         char *x_buffer;
3105         int retval = 0;
3106
3107         if (obj->hdr_chunk < 1)
3108                 return -ENODATA;
3109
3110         /* If we know that the object has no xattribs then don't do all the
3111          * reading and parsing.
3112          */
3113         if (obj->xattr_known && !obj->has_xattr) {
3114                 if (name)
3115                         return -ENODATA;
3116                 else
3117                         return 0;
3118         }
3119
3120         buffer = (char *)yaffs_get_temp_buffer(dev);
3121         if (!buffer)
3122                 return -ENOMEM;
3123
3124         result =
3125             yaffs_rd_chunk_tags_nand(dev, obj->hdr_chunk, (u8 *) buffer, &tags);
3126
3127         if (result != YAFFS_OK)
3128                 retval = -ENOENT;
3129         else {
3130                 x_buffer = buffer + x_offs;
3131
3132                 if (!obj->xattr_known) {
3133                         obj->has_xattr = nval_hasvalues(x_buffer, x_size);
3134                         obj->xattr_known = 1;
3135                 }
3136
3137                 if (name)
3138                         retval = nval_get(x_buffer, x_size, name, value, size);
3139                 else
3140                         retval = nval_list(x_buffer, x_size, value, size);
3141         }
3142         yaffs_release_temp_buffer(dev, (u8 *) buffer);
3143         return retval;
3144 }
3145
3146 int yaffs_set_xattrib(struct yaffs_obj *obj, const YCHAR * name,
3147                       const void *value, int size, int flags)
3148 {
3149         return yaffs_do_xattrib_mod(obj, 1, name, value, size, flags);
3150 }
3151
3152 int yaffs_remove_xattrib(struct yaffs_obj *obj, const YCHAR * name)
3153 {
3154         return yaffs_do_xattrib_mod(obj, 0, name, NULL, 0, 0);
3155 }
3156
3157 int yaffs_get_xattrib(struct yaffs_obj *obj, const YCHAR * name, void *value,
3158                       int size)
3159 {
3160         return yaffs_do_xattrib_fetch(obj, name, value, size);
3161 }
3162
3163 int yaffs_list_xattrib(struct yaffs_obj *obj, char *buffer, int size)
3164 {
3165         return yaffs_do_xattrib_fetch(obj, NULL, buffer, size);
3166 }
3167
3168 static void yaffs_check_obj_details_loaded(struct yaffs_obj *in)
3169 {
3170         u8 *buf;
3171         struct yaffs_obj_hdr *oh;
3172         struct yaffs_dev *dev;
3173         struct yaffs_ext_tags tags;
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         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         }
3193         yaffs_release_temp_buffer(dev, buf);
3194 }
3195
3196 static void yaffs_load_name_from_oh(struct yaffs_dev *dev, YCHAR *name,
3197                                     const YCHAR *oh_name, int buff_size)
3198 {
3199 #ifdef CONFIG_YAFFS_AUTO_UNICODE
3200         if (dev->param.auto_unicode) {
3201                 if (*oh_name) {
3202                         /* It is an ASCII name, do an ASCII to
3203                          * unicode conversion */
3204                         const char *ascii_oh_name = (const char *)oh_name;
3205                         int n = buff_size - 1;
3206                         while (n > 0 && *ascii_oh_name) {
3207                                 *name = *ascii_oh_name;
3208                                 name++;
3209                                 ascii_oh_name++;
3210                                 n--;
3211                         }
3212                 } else {
3213                         yaffs_strncpy(name, oh_name + 1, buff_size - 1);
3214                 }
3215         } else {
3216 #else
3217         dev = dev;
3218         {
3219 #endif
3220                 yaffs_strncpy(name, oh_name, buff_size - 1);
3221         }
3222 }
3223
3224 static void yaffs_load_oh_from_name(struct yaffs_dev *dev, YCHAR *oh_name,
3225                                     const YCHAR *name)
3226 {
3227 #ifdef CONFIG_YAFFS_AUTO_UNICODE
3228
3229         int is_ascii;
3230         YCHAR *w;
3231
3232         if (dev->param.auto_unicode) {
3233
3234                 is_ascii = 1;
3235                 w = name;
3236
3237                 /* Figure out if the name will fit in ascii character set */
3238                 while (is_ascii && *w) {
3239                         if ((*w) & 0xff00)
3240                                 is_ascii = 0;
3241                         w++;
3242                 }
3243
3244                 if (is_ascii) {
3245                         /* It is an ASCII name, so convert unicode to ascii */
3246                         char *ascii_oh_name = (char *)oh_name;
3247                         int n = YAFFS_MAX_NAME_LENGTH - 1;
3248                         while (n > 0 && *name) {
3249                                 *ascii_oh_name = *name;
3250                                 name++;
3251                                 ascii_oh_name++;
3252                                 n--;
3253                         }
3254                 } else {
3255                         /* Unicode name, so save starting at the second YCHAR */
3256                         *oh_name = 0;
3257                         yaffs_strncpy(oh_name + 1, name, YAFFS_MAX_NAME_LENGTH - 2);
3258                 }
3259         } else {
3260 #else
3261         dev = dev;
3262         {
3263 #endif
3264                 yaffs_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 new_chunk_id;
3280         struct yaffs_ext_tags new_tags;
3281         struct yaffs_ext_tags old_tags;
3282         const YCHAR *alias = NULL;
3283         u8 *buffer = NULL;
3284         YCHAR old_name[YAFFS_MAX_NAME_LENGTH + 1];
3285         struct yaffs_obj_hdr *oh = NULL;
3286         loff_t file_size = 0;
3287
3288         yaffs_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                 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                 if (oh->parent_obj_id != YAFFS_OBJECTID_DELETED &&
3340                     oh->parent_obj_id != YAFFS_OBJECTID_UNLINKED)
3341                         file_size = in->variant.file_variant.file_size;
3342                 yaffs_oh_size_load(oh, 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                 yaffs_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_file_size = 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_through)
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         loff_t start_write = offset;
3515         int chunk_written = 0;
3516         u32 n_bytes_read;
3517         loff_t 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 (((loff_t)chunk) *
3526                     dev->data_bytes_per_chunk + start != offset ||
3527                     start >= dev->data_bytes_per_chunk) {
3528                         yaffs_trace(YAFFS_TRACE_ERROR,
3529                                 "AddrToChunk of offset %lld gives chunk %d start %d",
3530                                 offset, chunk, start);
3531                 }
3532                 chunk++;        /* File pos to chunk in file offset */
3533
3534                 /* OK now check for the curveball where the start and end are in
3535                  * the same chunk.
3536                  */
3537
3538                 if ((start + n) < dev->data_bytes_per_chunk) {
3539                         n_copy = n;
3540
3541                         /* Now calculate how many bytes to write back....
3542                          * If we're overwriting and not writing to then end of
3543                          * file then we need to write back as much as was there
3544                          * before.
3545                          */
3546
3547                         chunk_start = (((loff_t)(chunk - 1)) *
3548                                         dev->data_bytes_per_chunk);
3549
3550                         if (chunk_start > in->variant.file_variant.file_size)
3551                                 n_bytes_read = 0;       /* Past end of file */
3552                         else
3553                                 n_bytes_read =
3554                                     in->variant.file_variant.file_size -
3555                                     chunk_start;
3556
3557                         if (n_bytes_read > dev->data_bytes_per_chunk)
3558                                 n_bytes_read = dev->data_bytes_per_chunk;
3559
3560                         n_writeback =
3561                             (n_bytes_read >
3562                              (start + n)) ? n_bytes_read : (start + n);
3563
3564                         if (n_writeback < 0 ||
3565                             n_writeback > dev->data_bytes_per_chunk)
3566                                 BUG();
3567
3568                 } else {
3569                         n_copy = dev->data_bytes_per_chunk - start;
3570                         n_writeback = dev->data_bytes_per_chunk;
3571                 }
3572
3573                 if (n_copy != dev->data_bytes_per_chunk ||
3574                     dev->param.inband_tags) {
3575                         /* An incomplete start or end chunk (or maybe both
3576                          * start and end chunk), or we're using inband tags,
3577                          * so we want to use the cache buffers.
3578                          */
3579                         if (dev->param.n_caches > 0) {
3580                                 struct yaffs_cache *cache;
3581
3582                                 /* If we can't find the data in the cache, then
3583                                  * load the cache */
3584                                 cache = yaffs_find_chunk_cache(in, chunk);
3585
3586                                 if (!cache &&
3587                                     yaffs_check_alloc_available(dev, 1)) {
3588                                         cache = yaffs_grab_chunk_cache(dev);
3589                                         cache->object = in;
3590                                         cache->chunk_id = chunk;
3591                                         cache->dirty = 0;
3592                                         cache->locked = 0;
3593                                         yaffs_rd_data_obj(in, chunk,
3594                                                           cache->data);
3595                                 } else if (cache &&
3596                                            !cache->dirty &&
3597                                            !yaffs_check_alloc_available(dev,
3598                                                                         1)) {
3599                                         /* Drop the cache if it was a read cache
3600                                          * item and no space check has been made
3601                                          * for it.
3602                                          */
3603                                         cache = NULL;
3604                                 }
3605
3606                                 if (cache) {
3607                                         yaffs_use_cache(dev, cache, 1);
3608                                         cache->locked = 1;
3609
3610                                         memcpy(&cache->data[start], buffer,
3611                                                n_copy);
3612
3613                                         cache->locked = 0;
3614                                         cache->n_bytes = n_writeback;
3615
3616                                         if (write_through) {
3617                                                 chunk_written =
3618                                                     yaffs_wr_data_obj
3619                                                     (cache->object,
3620                                                      cache->chunk_id,
3621                                                      cache->data,
3622                                                      cache->n_bytes, 1);
3623                                                 cache->dirty = 0;
3624                                         }
3625                                 } else {
3626                                         chunk_written = -1;     /* fail write */
3627                                 }
3628                         } else {
3629                                 /* An incomplete start or end chunk (or maybe
3630                                  * both start and end chunk). Read into the
3631                                  * local buffer then copy over and write back.
3632                                  */
3633
3634                                 u8 *local_buffer = yaffs_get_temp_buffer(dev);
3635
3636                                 yaffs_rd_data_obj(in, chunk, local_buffer);
3637                                 memcpy(&local_buffer[start], buffer, n_copy);
3638
3639                                 chunk_written =
3640                                     yaffs_wr_data_obj(in, chunk,
3641                                                       local_buffer,
3642                                                       n_writeback, 0);
3643
3644                                 yaffs_release_temp_buffer(dev, local_buffer);
3645                         }
3646                 } else {
3647                         /* A full chunk. Write directly from the buffer. */
3648
3649                         chunk_written =
3650                             yaffs_wr_data_obj(in, chunk, buffer,
3651                                               dev->data_bytes_per_chunk, 0);
3652
3653                         /* Since we've overwritten the cached data,
3654                          * we better invalidate it. */
3655                         yaffs_invalidate_chunk_cache(in, chunk);
3656                 }
3657
3658                 if (chunk_written >= 0) {
3659                         n -= n_copy;
3660                         offset += n_copy;
3661                         buffer += n_copy;
3662                         n_done += n_copy;
3663                 }
3664         }
3665
3666         /* Update file object */
3667
3668         if ((start_write + n_done) > in->variant.file_variant.file_size)
3669                 in->variant.file_variant.file_size = (start_write + n_done);
3670
3671         in->dirty = 1;
3672         return n_done;
3673 }
3674
3675 int yaffs_wr_file(struct yaffs_obj *in, const u8 *buffer, loff_t offset,
3676                   int n_bytes, int write_through)
3677 {
3678         yaffs2_handle_hole(in, offset);
3679         return yaffs_do_file_wr(in, buffer, offset, n_bytes, write_through);
3680 }
3681
3682 /* ---------------------- File resizing stuff ------------------ */
3683
3684 static void yaffs_prune_chunks(struct yaffs_obj *in, loff_t new_size)
3685 {
3686
3687         struct yaffs_dev *dev = in->my_dev;
3688         loff_t old_size = in->variant.file_variant.file_size;
3689         int i;
3690         int chunk_id;
3691         u32 dummy;
3692         int last_del;
3693         int start_del;
3694
3695         if (old_size > 0)
3696                 yaffs_addr_to_chunk(dev, old_size - 1, &last_del, &dummy);
3697         else
3698                 last_del = 0;
3699
3700         yaffs_addr_to_chunk(dev, new_size + dev->data_bytes_per_chunk - 1,
3701                                 &start_del, &dummy);
3702         last_del++;
3703         start_del++;
3704
3705         /* Delete backwards so that we don't end up with holes if
3706          * power is lost part-way through the operation.
3707          */
3708         for (i = last_del; i >= start_del; i--) {
3709                 /* NB this could be optimised somewhat,
3710                  * eg. could retrieve the tags and write them without
3711                  * using yaffs_chunk_del
3712                  */
3713
3714                 chunk_id = yaffs_find_del_file_chunk(in, i, NULL);
3715
3716                 if (chunk_id < 1)
3717                         continue;
3718
3719                 if (chunk_id <
3720                     (dev->internal_start_block * dev->param.chunks_per_block) ||
3721                     chunk_id >=
3722                     ((dev->internal_end_block + 1) *
3723                       dev->param.chunks_per_block)) {
3724                         yaffs_trace(YAFFS_TRACE_ALWAYS,
3725                                 "Found daft chunk_id %d for %d",
3726                                 chunk_id, i);
3727                 } else {
3728                         in->n_data_chunks--;
3729                         yaffs_chunk_del(dev, chunk_id, 1, __LINE__);
3730                 }
3731         }
3732 }
3733
3734 void yaffs_resize_file_down(struct yaffs_obj *obj, loff_t new_size)
3735 {
3736         int new_full;
3737         u32 new_partial;
3738         struct yaffs_dev *dev = obj->my_dev;
3739
3740         yaffs_addr_to_chunk(dev, new_size, &new_full, &new_partial);
3741
3742         yaffs_prune_chunks(obj, new_size);
3743
3744         if (new_partial != 0) {
3745                 int last_chunk = 1 + new_full;
3746                 u8 *local_buffer = yaffs_get_temp_buffer(dev);
3747
3748                 /* Rewrite the last chunk with its new size and zero pad */
3749                 yaffs_rd_data_obj(obj, last_chunk, local_buffer);
3750                 memset(local_buffer + new_partial, 0,
3751                        dev->data_bytes_per_chunk - new_partial);
3752
3753                 yaffs_wr_data_obj(obj, last_chunk, local_buffer,
3754                                   new_partial, 1);
3755
3756                 yaffs_release_temp_buffer(dev, local_buffer);
3757         }
3758
3759         obj->variant.file_variant.file_size = new_size;
3760
3761         yaffs_prune_tree(dev, &obj->variant.file_variant);
3762 }
3763
3764 int yaffs_resize_file(struct yaffs_obj *in, loff_t new_size)
3765 {
3766         struct yaffs_dev *dev = in->my_dev;
3767         loff_t old_size = in->variant.file_variant.file_size;
3768
3769         yaffs_flush_file_cache(in);
3770         yaffs_invalidate_whole_cache(in);
3771
3772         yaffs_check_gc(dev, 0);
3773
3774         if (in->variant_type != YAFFS_OBJECT_TYPE_FILE)
3775                 return YAFFS_FAIL;
3776
3777         if (new_size == old_size)
3778                 return YAFFS_OK;
3779
3780         if (new_size > old_size) {
3781                 yaffs2_handle_hole(in, new_size);
3782                 in->variant.file_variant.file_size = new_size;
3783         } else {
3784                 /* new_size < old_size */
3785                 yaffs_resize_file_down(in, new_size);
3786         }
3787
3788         /* Write a new object header to reflect the resize.
3789          * show we've shrunk the file, if need be
3790          * Do this only if the file is not in the deleted directories
3791          * and is not shadowed.
3792          */
3793         if (in->parent &&
3794             !in->is_shadowed &&
3795             in->parent->obj_id != YAFFS_OBJECTID_UNLINKED &&
3796             in->parent->obj_id != YAFFS_OBJECTID_DELETED)
3797                 yaffs_update_oh(in, NULL, 0, 0, 0, NULL);
3798
3799         return YAFFS_OK;
3800 }
3801
3802 int yaffs_flush_file(struct yaffs_obj *in, int update_time, int data_sync)
3803 {
3804         if (!in->dirty)
3805                 return YAFFS_OK;
3806
3807         yaffs_flush_file_cache(in);
3808
3809         if (data_sync)
3810                 return YAFFS_OK;
3811
3812         if (update_time)
3813                 yaffs_load_current_time(in, 0, 0);
3814
3815         return (yaffs_update_oh(in, NULL, 0, 0, 0, NULL) >= 0) ?
3816                                 YAFFS_OK : YAFFS_FAIL;
3817 }
3818
3819
3820 /* yaffs_del_file deletes the whole file data
3821  * and the inode associated with the file.
3822  * It does not delete the links associated with the file.
3823  */
3824 static int yaffs_unlink_file_if_needed(struct yaffs_obj *in)
3825 {
3826         int ret_val;
3827         int del_now = 0;
3828         struct yaffs_dev *dev = in->my_dev;
3829
3830         if (!in->my_inode)
3831                 del_now = 1;
3832
3833         if (del_now) {
3834                 ret_val =
3835                     yaffs_change_obj_name(in, in->my_dev->del_dir,
3836                                           _Y("deleted"), 0, 0);
3837                 yaffs_trace(YAFFS_TRACE_TRACING,
3838                         "yaffs: immediate deletion of file %d",
3839                         in->obj_id);
3840                 in->deleted = 1;
3841                 in->my_dev->n_deleted_files++;
3842                 if (dev->param.disable_soft_del || dev->param.is_yaffs2)
3843                         yaffs_resize_file(in, 0);
3844                 yaffs_soft_del_file(in);
3845         } else {
3846                 ret_val =
3847                     yaffs_change_obj_name(in, in->my_dev->unlinked_dir,
3848                                           _Y("unlinked"), 0, 0);
3849         }
3850         return ret_val;
3851 }
3852
3853 int yaffs_del_file(struct yaffs_obj *in)
3854 {
3855         int ret_val = YAFFS_OK;
3856         int deleted;    /* Need to cache value on stack if in is freed */
3857         struct yaffs_dev *dev = in->my_dev;
3858
3859         if (dev->param.disable_soft_del || dev->param.is_yaffs2)
3860                 yaffs_resize_file(in, 0);
3861
3862         if (in->n_data_chunks > 0) {
3863                 /* Use soft deletion if there is data in the file.
3864                  * That won't be the case if it has been resized to zero.
3865                  */
3866                 if (!in->unlinked)
3867                         ret_val = yaffs_unlink_file_if_needed(in);
3868
3869                 deleted = in->deleted;
3870
3871                 if (ret_val == YAFFS_OK && in->unlinked && !in->deleted) {
3872                         in->deleted = 1;
3873                         deleted = 1;
3874                         in->my_dev->n_deleted_files++;
3875                         yaffs_soft_del_file(in);
3876                 }
3877                 return deleted ? YAFFS_OK : YAFFS_FAIL;
3878         } else {
3879                 /* The file has no data chunks so we toss it immediately */
3880                 yaffs_free_tnode(in->my_dev, in->variant.file_variant.top);
3881                 in->variant.file_variant.top = NULL;
3882                 yaffs_generic_obj_del(in);
3883
3884                 return YAFFS_OK;
3885         }
3886 }
3887
3888 int yaffs_is_non_empty_dir(struct yaffs_obj *obj)
3889 {
3890         return (obj &&
3891                 obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY) &&
3892                 !(list_empty(&obj->variant.dir_variant.children));
3893 }
3894
3895 static int yaffs_del_dir(struct yaffs_obj *obj)
3896 {
3897         /* First check that the directory is empty. */
3898         if (yaffs_is_non_empty_dir(obj))
3899                 return YAFFS_FAIL;
3900
3901         return yaffs_generic_obj_del(obj);
3902 }
3903
3904 static int yaffs_del_symlink(struct yaffs_obj *in)
3905 {
3906         kfree(in->variant.symlink_variant.alias);
3907         in->variant.symlink_variant.alias = NULL;
3908
3909         return yaffs_generic_obj_del(in);
3910 }
3911
3912 static int yaffs_del_link(struct yaffs_obj *in)
3913 {
3914         /* remove this hardlink from the list associated with the equivalent
3915          * object
3916          */
3917         list_del_init(&in->hard_links);
3918         return yaffs_generic_obj_del(in);
3919 }
3920
3921 int yaffs_del_obj(struct yaffs_obj *obj)
3922 {
3923         int ret_val = -1;
3924
3925         switch (obj->variant_type) {
3926         case YAFFS_OBJECT_TYPE_FILE:
3927                 ret_val = yaffs_del_file(obj);
3928                 break;
3929         case YAFFS_OBJECT_TYPE_DIRECTORY:
3930                 if (!list_empty(&obj->variant.dir_variant.dirty)) {
3931                         yaffs_trace(YAFFS_TRACE_BACKGROUND,
3932                                 "Remove object %d from dirty directories",
3933                                 obj->obj_id);
3934                         list_del_init(&obj->variant.dir_variant.dirty);
3935                 }
3936                 return yaffs_del_dir(obj);
3937                 break;
3938         case YAFFS_OBJECT_TYPE_SYMLINK:
3939                 ret_val = yaffs_del_symlink(obj);
3940                 break;
3941         case YAFFS_OBJECT_TYPE_HARDLINK:
3942                 ret_val = yaffs_del_link(obj);
3943                 break;
3944         case YAFFS_OBJECT_TYPE_SPECIAL:
3945                 ret_val = yaffs_generic_obj_del(obj);
3946                 break;
3947         case YAFFS_OBJECT_TYPE_UNKNOWN:
3948                 ret_val = 0;
3949                 break;          /* should not happen. */
3950         }
3951         return ret_val;
3952 }
3953
3954 static int yaffs_unlink_worker(struct yaffs_obj *obj)
3955 {
3956         int del_now = 0;
3957
3958         if (!obj)
3959                 return YAFFS_FAIL;
3960
3961         if (!obj->my_inode)
3962                 del_now = 1;
3963
3964         yaffs_update_parent(obj->parent);
3965
3966         if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
3967                 return yaffs_del_link(obj);
3968         } else if (!list_empty(&obj->hard_links)) {
3969                 /* Curve ball: We're unlinking an object that has a hardlink.
3970                  *
3971                  * This problem arises because we are not strictly following
3972                  * The Linux link/inode model.
3973                  *
3974                  * We can't really delete the object.
3975                  * Instead, we do the following:
3976                  * - Select a hardlink.
3977                  * - Unhook it from the hard links
3978                  * - Move it from its parent directory so that the rename works.
3979                  * - Rename the object to the hardlink's name.
3980                  * - Delete the hardlink
3981                  */
3982
3983                 struct yaffs_obj *hl;
3984                 struct yaffs_obj *parent;
3985                 int ret_val;
3986                 YCHAR name[YAFFS_MAX_NAME_LENGTH + 1];
3987
3988                 hl = list_entry(obj->hard_links.next, struct yaffs_obj,
3989                                 hard_links);
3990
3991                 yaffs_get_obj_name(hl, name, YAFFS_MAX_NAME_LENGTH + 1);
3992                 parent = hl->parent;
3993
3994                 list_del_init(&hl->hard_links);
3995
3996                 yaffs_add_obj_to_dir(obj->my_dev->unlinked_dir, hl);
3997
3998                 ret_val = yaffs_change_obj_name(obj, parent, name, 0, 0);
3999
4000                 if (ret_val == YAFFS_OK)
4001                         ret_val = yaffs_generic_obj_del(hl);
4002
4003                 return ret_val;
4004
4005         } else if (del_now) {
4006                 switch (obj->variant_type) {
4007                 case YAFFS_OBJECT_TYPE_FILE:
4008                         return yaffs_del_file(obj);
4009                         break;
4010                 case YAFFS_OBJECT_TYPE_DIRECTORY:
4011                         list_del_init(&obj->variant.dir_variant.dirty);
4012                         return yaffs_del_dir(obj);
4013                         break;
4014                 case YAFFS_OBJECT_TYPE_SYMLINK:
4015                         return yaffs_del_symlink(obj);
4016                         break;
4017                 case YAFFS_OBJECT_TYPE_SPECIAL:
4018                         return yaffs_generic_obj_del(obj);
4019                         break;
4020                 case YAFFS_OBJECT_TYPE_HARDLINK:
4021                 case YAFFS_OBJECT_TYPE_UNKNOWN:
4022                 default:
4023                         return YAFFS_FAIL;
4024                 }
4025         } else if (yaffs_is_non_empty_dir(obj)) {
4026                 return YAFFS_FAIL;
4027         } else {
4028                 return yaffs_change_obj_name(obj, obj->my_dev->unlinked_dir,
4029                                                 _Y("unlinked"), 0, 0);
4030         }
4031 }
4032
4033 static int yaffs_unlink_obj(struct yaffs_obj *obj)
4034 {
4035         if (obj && obj->unlink_allowed)
4036                 return yaffs_unlink_worker(obj);
4037
4038         return YAFFS_FAIL;
4039 }
4040
4041 int yaffs_unlinker(struct yaffs_obj *dir, const YCHAR *name)
4042 {
4043         struct yaffs_obj *obj;
4044
4045         obj = yaffs_find_by_name(dir, name);
4046         return yaffs_unlink_obj(obj);
4047 }
4048
4049 /* Note:
4050  * If old_name is NULL then we take old_dir as the object to be renamed.
4051  */
4052 int yaffs_rename_obj(struct yaffs_obj *old_dir, const YCHAR *old_name,
4053                      struct yaffs_obj *new_dir, const YCHAR *new_name)
4054 {
4055         struct yaffs_obj *obj = NULL;
4056         struct yaffs_obj *existing_target = NULL;
4057         int force = 0;
4058         int result;
4059         struct yaffs_dev *dev;
4060
4061         if (!old_dir || old_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4062                 BUG();
4063                 return YAFFS_FAIL;
4064         }
4065         if (!new_dir || new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4066                 BUG();
4067                 return YAFFS_FAIL;
4068         }
4069
4070         dev = old_dir->my_dev;
4071
4072 #ifdef CONFIG_YAFFS_CASE_INSENSITIVE
4073         /* Special case for case insemsitive systems.
4074          * While look-up is case insensitive, the name isn't.
4075          * Therefore we might want to change x.txt to X.txt
4076          */
4077         if (old_dir == new_dir &&
4078                 old_name && new_name &&
4079                 yaffs_strcmp(old_name, new_name) == 0)
4080                 force = 1;
4081 #endif
4082
4083         if (yaffs_strnlen(new_name, YAFFS_MAX_NAME_LENGTH + 1) >
4084             YAFFS_MAX_NAME_LENGTH)
4085                 /* ENAMETOOLONG */
4086                 return YAFFS_FAIL;
4087
4088         if (old_name)
4089                 obj = yaffs_find_by_name(old_dir, old_name);
4090         else{
4091                 obj = old_dir;
4092                 old_dir = obj->parent;
4093         }
4094
4095         if (obj && obj->rename_allowed) {
4096                 /* Now handle an existing target, if there is one */
4097                 existing_target = yaffs_find_by_name(new_dir, new_name);
4098                 if (yaffs_is_non_empty_dir(existing_target)) {
4099                         return YAFFS_FAIL;      /* ENOTEMPTY */
4100                 } else if (existing_target && existing_target != obj) {
4101                         /* Nuke the target first, using shadowing,
4102                          * but only if it isn't the same object.
4103                          *
4104                          * Note we must disable gc here otherwise it can mess
4105                          * up the shadowing.
4106                          *
4107                          */
4108                         dev->gc_disable = 1;
4109                         yaffs_change_obj_name(obj, new_dir, new_name, force,
4110                                               existing_target->obj_id);
4111                         existing_target->is_shadowed = 1;
4112                         yaffs_unlink_obj(existing_target);
4113                         dev->gc_disable = 0;
4114                 }
4115
4116                 result = yaffs_change_obj_name(obj, new_dir, new_name, 1, 0);
4117
4118                 yaffs_update_parent(old_dir);
4119                 if (new_dir != old_dir)
4120                         yaffs_update_parent(new_dir);
4121
4122                 return result;
4123         }
4124         return YAFFS_FAIL;
4125 }
4126
4127 /*----------------------- Initialisation Scanning ---------------------- */
4128
4129 void yaffs_handle_shadowed_obj(struct yaffs_dev *dev, int obj_id,
4130                                int backward_scanning)
4131 {
4132         struct yaffs_obj *obj;
4133
4134         if (backward_scanning) {
4135                 /* Handle YAFFS2 case (backward scanning)
4136                  * If the shadowed object exists then ignore.
4137                  */
4138                 obj = yaffs_find_by_number(dev, obj_id);
4139                 if (obj)
4140                         return;
4141         }
4142
4143         /* Let's create it (if it does not exist) assuming it is a file so that
4144          * it can do shrinking etc.
4145          * We put it in unlinked dir to be cleaned up after the scanning
4146          */
4147         obj =
4148             yaffs_find_or_create_by_number(dev, obj_id, YAFFS_OBJECT_TYPE_FILE);
4149         if (!obj)
4150                 return;
4151         obj->is_shadowed = 1;
4152         yaffs_add_obj_to_dir(dev->unlinked_dir, obj);
4153         obj->variant.file_variant.shrink_size = 0;
4154         obj->valid = 1;         /* So that we don't read any other info. */
4155 }
4156
4157 void yaffs_link_fixup(struct yaffs_dev *dev, struct list_head *hard_list)
4158 {
4159         struct list_head *lh;
4160         struct list_head *save;
4161         struct yaffs_obj *hl;
4162         struct yaffs_obj *in;
4163
4164         list_for_each_safe(lh, save, hard_list) {
4165                 hl = list_entry(lh, struct yaffs_obj, hard_links);
4166                 in = yaffs_find_by_number(dev,
4167                                         hl->variant.hardlink_variant.equiv_id);
4168
4169                 if (in) {
4170                         /* Add the hardlink pointers */
4171                         hl->variant.hardlink_variant.equiv_obj = in;
4172                         list_add(&hl->hard_links, &in->hard_links);
4173                 } else {
4174                         /* Todo Need to report/handle this better.
4175                          * Got a problem... hardlink to a non-existant object
4176                          */
4177                         hl->variant.hardlink_variant.equiv_obj = NULL;
4178                         INIT_LIST_HEAD(&hl->hard_links);
4179                 }
4180         }
4181 }
4182
4183 static void yaffs_strip_deleted_objs(struct yaffs_dev *dev)
4184 {
4185         /*
4186          *  Sort out state of unlinked and deleted objects after scanning.
4187          */
4188         struct list_head *i;
4189         struct list_head *n;
4190         struct yaffs_obj *l;
4191
4192         if (dev->read_only)
4193                 return;
4194
4195         /* Soft delete all the unlinked files */
4196         list_for_each_safe(i, n,
4197                            &dev->unlinked_dir->variant.dir_variant.children) {
4198                 l = list_entry(i, struct yaffs_obj, siblings);
4199                 yaffs_del_obj(l);
4200         }
4201
4202         list_for_each_safe(i, n, &dev->del_dir->variant.dir_variant.children) {
4203                 l = list_entry(i, struct yaffs_obj, siblings);
4204                 yaffs_del_obj(l);
4205         }
4206 }
4207
4208 /*
4209  * This code iterates through all the objects making sure that they are rooted.
4210  * Any unrooted objects are re-rooted in lost+found.
4211  * An object needs to be in one of:
4212  * - Directly under deleted, unlinked
4213  * - Directly or indirectly under root.
4214  *
4215  * Note:
4216  *  This code assumes that we don't ever change the current relationships
4217  *  between directories:
4218  *   root_dir->parent == unlinked_dir->parent == del_dir->parent == NULL
4219  *   lost-n-found->parent == root_dir
4220  *
4221  * This fixes the problem where directories might have inadvertently been
4222  * deleted leaving the object "hanging" without being rooted in the
4223  * directory tree.
4224  */
4225
4226 static int yaffs_has_null_parent(struct yaffs_dev *dev, struct yaffs_obj *obj)
4227 {
4228         return (obj == dev->del_dir ||
4229                 obj == dev->unlinked_dir || obj == dev->root_dir);
4230 }
4231
4232 static void yaffs_fix_hanging_objs(struct yaffs_dev *dev)
4233 {
4234         struct yaffs_obj *obj;
4235         struct yaffs_obj *parent;
4236         int i;
4237         struct list_head *lh;
4238         struct list_head *n;
4239         int depth_limit;
4240         int hanging;
4241
4242         if (dev->read_only)
4243                 return;
4244
4245         /* Iterate through the objects in each hash entry,
4246          * looking at each object.
4247          * Make sure it is rooted.
4248          */
4249
4250         for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
4251                 list_for_each_safe(lh, n, &dev->obj_bucket[i].list) {
4252                         obj = list_entry(lh, struct yaffs_obj, hash_link);
4253                         parent = obj->parent;
4254
4255                         if (yaffs_has_null_parent(dev, obj)) {
4256                                 /* These directories are not hanging */
4257                                 hanging = 0;
4258                         } else if (!parent ||
4259                                    parent->variant_type !=
4260                                    YAFFS_OBJECT_TYPE_DIRECTORY) {
4261                                 hanging = 1;
4262                         } else if (yaffs_has_null_parent(dev, parent)) {
4263                                 hanging = 0;
4264                         } else {
4265                                 /*
4266                                  * Need to follow the parent chain to
4267                                  * see if it is hanging.
4268                                  */
4269                                 hanging = 0;
4270                                 depth_limit = 100;
4271
4272                                 while (parent != dev->root_dir &&
4273                                        parent->parent &&
4274                                        parent->parent->variant_type ==
4275                                        YAFFS_OBJECT_TYPE_DIRECTORY &&
4276                                        depth_limit > 0) {
4277                                         parent = parent->parent;
4278                                         depth_limit--;
4279                                 }
4280                                 if (parent != dev->root_dir)
4281                                         hanging = 1;
4282                         }
4283                         if (hanging) {
4284                                 yaffs_trace(YAFFS_TRACE_SCAN,
4285                                         "Hanging object %d moved to lost and found",
4286                                         obj->obj_id);
4287                                 yaffs_add_obj_to_dir(dev->lost_n_found, obj);
4288                         }
4289                 }
4290         }
4291 }
4292
4293 /*
4294  * Delete directory contents for cleaning up lost and found.
4295  */
4296 static void yaffs_del_dir_contents(struct yaffs_obj *dir)
4297 {
4298         struct yaffs_obj *obj;
4299         struct list_head *lh;
4300         struct list_head *n;
4301
4302         if (dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
4303                 BUG();
4304
4305         list_for_each_safe(lh, n, &dir->variant.dir_variant.children) {
4306                 obj = list_entry(lh, struct yaffs_obj, siblings);
4307                 if (obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY)
4308                         yaffs_del_dir_contents(obj);
4309                 yaffs_trace(YAFFS_TRACE_SCAN,
4310                         "Deleting lost_found object %d",
4311                         obj->obj_id);
4312                 yaffs_unlink_obj(obj);
4313         }
4314 }
4315
4316 static void yaffs_empty_l_n_f(struct yaffs_dev *dev)
4317 {
4318         yaffs_del_dir_contents(dev->lost_n_found);
4319 }
4320
4321
4322 struct yaffs_obj *yaffs_find_by_name(struct yaffs_obj *directory,
4323                                      const YCHAR *name)
4324 {
4325         int sum;
4326         struct list_head *i;
4327         YCHAR buffer[YAFFS_MAX_NAME_LENGTH + 1];
4328         struct yaffs_obj *l;
4329
4330         if (!name)
4331                 return NULL;
4332
4333         if (!directory) {
4334                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4335                         "tragedy: yaffs_find_by_name: null pointer directory"
4336                         );
4337                 BUG();
4338                 return NULL;
4339         }
4340         if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4341                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4342                         "tragedy: yaffs_find_by_name: non-directory"
4343                         );
4344                 BUG();
4345         }
4346
4347         sum = yaffs_calc_name_sum(name);
4348
4349         list_for_each(i, &directory->variant.dir_variant.children) {
4350                 l = list_entry(i, struct yaffs_obj, siblings);
4351
4352                 if (l->parent != directory)
4353                         BUG();
4354
4355                 yaffs_check_obj_details_loaded(l);
4356
4357                 /* Special case for lost-n-found */
4358                 if (l->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
4359                         if (!yaffs_strcmp(name, YAFFS_LOSTNFOUND_NAME))
4360                                 return l;
4361                 } else if (l->sum == sum || l->hdr_chunk <= 0) {
4362                         /* LostnFound chunk called Objxxx
4363                          * Do a real check
4364                          */
4365                         yaffs_get_obj_name(l, buffer,
4366                                 YAFFS_MAX_NAME_LENGTH + 1);
4367                         if (!yaffs_strncmp(name, buffer, YAFFS_MAX_NAME_LENGTH))
4368                                 return l;
4369                 }
4370         }
4371         return NULL;
4372 }
4373
4374 /* GetEquivalentObject dereferences any hard links to get to the
4375  * actual object.
4376  */
4377
4378 struct yaffs_obj *yaffs_get_equivalent_obj(struct yaffs_obj *obj)
4379 {
4380         if (obj && obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
4381                 obj = obj->variant.hardlink_variant.equiv_obj;
4382                 yaffs_check_obj_details_loaded(obj);
4383         }
4384         return obj;
4385 }
4386
4387 /*
4388  *  A note or two on object names.
4389  *  * If the object name is missing, we then make one up in the form objnnn
4390  *
4391  *  * ASCII names are stored in the object header's name field from byte zero
4392  *  * Unicode names are historically stored starting from byte zero.
4393  *
4394  * Then there are automatic Unicode names...
4395  * The purpose of these is to save names in a way that can be read as
4396  * ASCII or Unicode names as appropriate, thus allowing a Unicode and ASCII
4397  * system to share files.
4398  *
4399  * These automatic unicode are stored slightly differently...
4400  *  - If the name can fit in the ASCII character space then they are saved as
4401  *    ascii names as per above.
4402  *  - If the name needs Unicode then the name is saved in Unicode
4403  *    starting at oh->name[1].
4404
4405  */
4406 static void yaffs_fix_null_name(struct yaffs_obj *obj, YCHAR *name,
4407                                 int buffer_size)
4408 {
4409         /* Create an object name if we could not find one. */
4410         if (yaffs_strnlen(name, YAFFS_MAX_NAME_LENGTH) == 0) {
4411                 YCHAR local_name[20];
4412                 YCHAR num_string[20];
4413                 YCHAR *x = &num_string[19];
4414                 unsigned v = obj->obj_id;
4415                 num_string[19] = 0;
4416                 while (v > 0) {
4417                         x--;
4418                         *x = '0' + (v % 10);
4419                         v /= 10;
4420                 }
4421                 /* make up a name */
4422                 yaffs_strcpy(local_name, YAFFS_LOSTNFOUND_PREFIX);
4423                 yaffs_strcat(local_name, x);
4424                 yaffs_strncpy(name, local_name, buffer_size - 1);
4425         }
4426 }
4427
4428 int yaffs_get_obj_name(struct yaffs_obj *obj, YCHAR *name, int buffer_size)
4429 {
4430         memset(name, 0, buffer_size * sizeof(YCHAR));
4431         yaffs_check_obj_details_loaded(obj);
4432         if (obj->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
4433                 yaffs_strncpy(name, YAFFS_LOSTNFOUND_NAME, buffer_size - 1);
4434         } else if (obj->short_name[0]) {
4435                 yaffs_strcpy(name, obj->short_name);
4436         } else if (obj->hdr_chunk > 0) {
4437                 u8 *buffer = yaffs_get_temp_buffer(obj->my_dev);
4438
4439                 struct yaffs_obj_hdr *oh = (struct yaffs_obj_hdr *)buffer;
4440
4441                 memset(buffer, 0, obj->my_dev->data_bytes_per_chunk);
4442
4443                 if (obj->hdr_chunk > 0) {
4444                         yaffs_rd_chunk_tags_nand(obj->my_dev,
4445                                                  obj->hdr_chunk,
4446                                                  buffer, NULL);
4447                 }
4448                 yaffs_load_name_from_oh(obj->my_dev, name, oh->name,
4449                                         buffer_size);
4450
4451                 yaffs_release_temp_buffer(obj->my_dev, buffer);
4452         }
4453
4454         yaffs_fix_null_name(obj, name, buffer_size);
4455
4456         return yaffs_strnlen(name, YAFFS_MAX_NAME_LENGTH);
4457 }
4458
4459 loff_t yaffs_get_obj_length(struct yaffs_obj *obj)
4460 {
4461         /* Dereference any hard linking */
4462         obj = yaffs_get_equivalent_obj(obj);
4463
4464         if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
4465                 return obj->variant.file_variant.file_size;
4466         if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
4467                 if (!obj->variant.symlink_variant.alias)
4468                         return 0;
4469                 return yaffs_strnlen(obj->variant.symlink_variant.alias,
4470                                      YAFFS_MAX_ALIAS_LENGTH);
4471         } else {
4472                 /* Only a directory should drop through to here */
4473                 return obj->my_dev->data_bytes_per_chunk;
4474         }
4475 }
4476
4477 int yaffs_get_obj_link_count(struct yaffs_obj *obj)
4478 {
4479         int count = 0;
4480         struct list_head *i;
4481
4482         if (!obj->unlinked)
4483                 count++;        /* the object itself */
4484
4485         list_for_each(i, &obj->hard_links)
4486             count++;            /* add the hard links; */
4487
4488         return count;
4489 }
4490
4491 int yaffs_get_obj_inode(struct yaffs_obj *obj)
4492 {
4493         obj = yaffs_get_equivalent_obj(obj);
4494
4495         return obj->obj_id;
4496 }
4497
4498 unsigned yaffs_get_obj_type(struct yaffs_obj *obj)
4499 {
4500         obj = yaffs_get_equivalent_obj(obj);
4501
4502         switch (obj->variant_type) {
4503         case YAFFS_OBJECT_TYPE_FILE:
4504                 return DT_REG;
4505                 break;
4506         case YAFFS_OBJECT_TYPE_DIRECTORY:
4507                 return DT_DIR;
4508                 break;
4509         case YAFFS_OBJECT_TYPE_SYMLINK:
4510                 return DT_LNK;
4511                 break;
4512         case YAFFS_OBJECT_TYPE_HARDLINK:
4513                 return DT_REG;
4514                 break;
4515         case YAFFS_OBJECT_TYPE_SPECIAL:
4516                 if (S_ISFIFO(obj->yst_mode))
4517                         return DT_FIFO;
4518                 if (S_ISCHR(obj->yst_mode))
4519                         return DT_CHR;
4520                 if (S_ISBLK(obj->yst_mode))
4521                         return DT_BLK;
4522                 if (S_ISSOCK(obj->yst_mode))
4523                         return DT_SOCK;
4524                 return DT_REG;
4525                 break;
4526         default:
4527                 return DT_REG;
4528                 break;
4529         }
4530 }
4531
4532 YCHAR *yaffs_get_symlink_alias(struct yaffs_obj *obj)
4533 {
4534         obj = yaffs_get_equivalent_obj(obj);
4535         if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK)
4536                 return yaffs_clone_str(obj->variant.symlink_variant.alias);
4537         else
4538                 return yaffs_clone_str(_Y(""));
4539 }
4540
4541 /*--------------------------- Initialisation code -------------------------- */
4542
4543 static int yaffs_check_dev_fns(const struct yaffs_dev *dev)
4544 {
4545         /* Common functions, gotta have */
4546         if (!dev->param.erase_fn || !dev->param.initialise_flash_fn)
4547                 return 0;
4548
4549         /* Can use the "with tags" style interface for yaffs1 or yaffs2 */
4550         if (dev->param.write_chunk_tags_fn &&
4551             dev->param.read_chunk_tags_fn &&
4552             !dev->param.write_chunk_fn &&
4553             !dev->param.read_chunk_fn &&
4554             dev->param.bad_block_fn && dev->param.query_block_fn)
4555                 return 1;
4556
4557         /* Can use the "spare" style interface for yaffs1 */
4558         if (!dev->param.is_yaffs2 &&
4559             !dev->param.write_chunk_tags_fn &&
4560             !dev->param.read_chunk_tags_fn &&
4561             dev->param.write_chunk_fn &&
4562             dev->param.read_chunk_fn &&
4563             !dev->param.bad_block_fn && !dev->param.query_block_fn)
4564                 return 1;
4565
4566         return 0;               /* bad */
4567 }
4568
4569 static int yaffs_create_initial_dir(struct yaffs_dev *dev)
4570 {
4571         /* Initialise the unlinked, deleted, root and lost+found directories */
4572         dev->lost_n_found = dev->root_dir = NULL;
4573         dev->unlinked_dir = dev->del_dir = NULL;
4574         dev->unlinked_dir =
4575             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_UNLINKED, S_IFDIR);
4576         dev->del_dir =
4577             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_DELETED, S_IFDIR);
4578         dev->root_dir =
4579             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_ROOT,
4580                                   YAFFS_ROOT_MODE | S_IFDIR);
4581         dev->lost_n_found =
4582             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_LOSTNFOUND,
4583                                   YAFFS_LOSTNFOUND_MODE | S_IFDIR);
4584
4585         if (dev->lost_n_found && dev->root_dir && dev->unlinked_dir
4586             && dev->del_dir) {
4587                 yaffs_add_obj_to_dir(dev->root_dir, dev->lost_n_found);
4588                 return YAFFS_OK;
4589         }
4590         return YAFFS_FAIL;
4591 }
4592
4593 int yaffs_guts_initialise(struct yaffs_dev *dev)
4594 {
4595         int init_failed = 0;
4596         unsigned x;
4597         int bits;
4598
4599         yaffs_trace(YAFFS_TRACE_TRACING, "yaffs: yaffs_guts_initialise()");
4600
4601         /* Check stuff that must be set */
4602
4603         if (!dev) {
4604                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4605                         "yaffs: Need a device"
4606                         );
4607                 return YAFFS_FAIL;
4608         }
4609
4610         if (dev->is_mounted) {
4611                 yaffs_trace(YAFFS_TRACE_ALWAYS, "device already mounted");
4612                 return YAFFS_FAIL;
4613         }
4614
4615         dev->internal_start_block = dev->param.start_block;
4616         dev->internal_end_block = dev->param.end_block;
4617         dev->block_offset = 0;
4618         dev->chunk_offset = 0;
4619         dev->n_free_chunks = 0;
4620
4621         dev->gc_block = 0;
4622
4623         if (dev->param.start_block == 0) {
4624                 dev->internal_start_block = dev->param.start_block + 1;
4625                 dev->internal_end_block = dev->param.end_block + 1;
4626                 dev->block_offset = 1;
4627                 dev->chunk_offset = dev->param.chunks_per_block;
4628         }
4629
4630         /* Check geometry parameters. */
4631
4632         if ((!dev->param.inband_tags && dev->param.is_yaffs2 &&
4633                 dev->param.total_bytes_per_chunk < 1024) ||
4634                 (!dev->param.is_yaffs2 &&
4635                         dev->param.total_bytes_per_chunk < 512) ||
4636                 (dev->param.inband_tags && !dev->param.is_yaffs2) ||
4637                  dev->param.chunks_per_block < 2 ||
4638                  dev->param.n_reserved_blocks < 2 ||
4639                 dev->internal_start_block <= 0 ||
4640                 dev->internal_end_block <= 0 ||
4641                 dev->internal_end_block <=
4642                 (dev->internal_start_block + dev->param.n_reserved_blocks + 2)
4643                 ) {
4644                 /* otherwise it is too small */
4645                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4646                         "NAND geometry problems: chunk size %d, type is yaffs%s, inband_tags %d ",
4647                         dev->param.total_bytes_per_chunk,
4648                         dev->param.is_yaffs2 ? "2" : "",
4649                         dev->param.inband_tags);
4650                 return YAFFS_FAIL;
4651         }
4652
4653         if (yaffs_init_nand(dev) != YAFFS_OK) {
4654                 yaffs_trace(YAFFS_TRACE_ALWAYS, "InitialiseNAND failed");
4655                 return YAFFS_FAIL;
4656         }
4657
4658         /* Sort out space for inband tags, if required */
4659         if (dev->param.inband_tags)
4660                 dev->data_bytes_per_chunk =
4661                     dev->param.total_bytes_per_chunk -
4662                     sizeof(struct yaffs_packed_tags2_tags_only);
4663         else
4664                 dev->data_bytes_per_chunk = dev->param.total_bytes_per_chunk;
4665
4666         /* Got the right mix of functions? */
4667         if (!yaffs_check_dev_fns(dev)) {
4668                 /* Function missing */
4669                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4670                         "device function(s) missing or wrong");
4671
4672                 return YAFFS_FAIL;
4673         }
4674
4675         /* Finished with most checks. Further checks happen later on too. */
4676
4677         dev->is_mounted = 1;
4678
4679         /* OK now calculate a few things for the device */
4680
4681         /*
4682          *  Calculate all the chunk size manipulation numbers:
4683          */
4684         x = dev->data_bytes_per_chunk;
4685         /* We always use dev->chunk_shift and dev->chunk_div */
4686         dev->chunk_shift = calc_shifts(x);
4687         x >>= dev->chunk_shift;
4688         dev->chunk_div = x;
4689         /* We only use chunk mask if chunk_div is 1 */
4690         dev->chunk_mask = (1 << dev->chunk_shift) - 1;
4691
4692         /*
4693          * Calculate chunk_grp_bits.
4694          * We need to find the next power of 2 > than internal_end_block
4695          */
4696
4697         x = dev->param.chunks_per_block * (dev->internal_end_block + 1);
4698
4699         bits = calc_shifts_ceiling(x);
4700
4701         /* Set up tnode width if wide tnodes are enabled. */
4702         if (!dev->param.wide_tnodes_disabled) {
4703                 /* bits must be even so that we end up with 32-bit words */
4704                 if (bits & 1)
4705                         bits++;
4706                 if (bits < 16)
4707                         dev->tnode_width = 16;
4708                 else
4709                         dev->tnode_width = bits;
4710         } else {
4711                 dev->tnode_width = 16;
4712         }
4713
4714         dev->tnode_mask = (1 << dev->tnode_width) - 1;
4715
4716         /* Level0 Tnodes are 16 bits or wider (if wide tnodes are enabled),
4717          * so if the bitwidth of the
4718          * chunk range we're using is greater than 16 we need
4719          * to figure out chunk shift and chunk_grp_size
4720          */
4721
4722         if (bits <= dev->tnode_width)
4723                 dev->chunk_grp_bits = 0;
4724         else
4725                 dev->chunk_grp_bits = bits - dev->tnode_width;
4726
4727         dev->tnode_size = (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8;
4728         if (dev->tnode_size < sizeof(struct yaffs_tnode))
4729                 dev->tnode_size = sizeof(struct yaffs_tnode);
4730
4731         dev->chunk_grp_size = 1 << dev->chunk_grp_bits;
4732
4733         if (dev->param.chunks_per_block < dev->chunk_grp_size) {
4734                 /* We have a problem because the soft delete won't work if
4735                  * the chunk group size > chunks per block.
4736                  * This can be remedied by using larger "virtual blocks".
4737                  */
4738                 yaffs_trace(YAFFS_TRACE_ALWAYS, "chunk group too large");
4739
4740                 return YAFFS_FAIL;
4741         }
4742
4743         /* Finished verifying the device, continue with initialisation */
4744
4745         /* More device initialisation */
4746         dev->all_gcs = 0;
4747         dev->passive_gc_count = 0;
4748         dev->oldest_dirty_gc_count = 0;
4749         dev->bg_gcs = 0;
4750         dev->gc_block_finder = 0;
4751         dev->buffered_block = -1;
4752         dev->doing_buffered_block_rewrite = 0;
4753         dev->n_deleted_files = 0;
4754         dev->n_bg_deletions = 0;
4755         dev->n_unlinked_files = 0;
4756         dev->n_ecc_fixed = 0;
4757         dev->n_ecc_unfixed = 0;
4758         dev->n_tags_ecc_fixed = 0;
4759         dev->n_tags_ecc_unfixed = 0;
4760         dev->n_erase_failures = 0;
4761         dev->n_erased_blocks = 0;
4762         dev->gc_disable = 0;
4763         dev->has_pending_prioritised_gc = 1;
4764                 /* Assume the worst for now, will get fixed on first GC */
4765         INIT_LIST_HEAD(&dev->dirty_dirs);
4766         dev->oldest_dirty_seq = 0;
4767         dev->oldest_dirty_block = 0;
4768
4769         /* Initialise temporary buffers and caches. */
4770         if (!yaffs_init_tmp_buffers(dev))
4771                 init_failed = 1;
4772
4773         dev->cache = NULL;
4774         dev->gc_cleanup_list = NULL;
4775
4776         if (!init_failed && dev->param.n_caches > 0) {
4777                 int i;
4778                 void *buf;
4779                 int cache_bytes =
4780                     dev->param.n_caches * sizeof(struct yaffs_cache);
4781
4782                 if (dev->param.n_caches > YAFFS_MAX_SHORT_OP_CACHES)
4783                         dev->param.n_caches = YAFFS_MAX_SHORT_OP_CACHES;
4784
4785                 dev->cache = kmalloc(cache_bytes, GFP_NOFS);
4786
4787                 buf = (u8 *) dev->cache;
4788
4789                 if (dev->cache)
4790                         memset(dev->cache, 0, cache_bytes);
4791
4792                 for (i = 0; i < dev->param.n_caches && buf; i++) {
4793                         dev->cache[i].object = NULL;
4794                         dev->cache[i].last_use = 0;
4795                         dev->cache[i].dirty = 0;
4796                         dev->cache[i].data = buf =
4797                             kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
4798                 }
4799                 if (!buf)
4800                         init_failed = 1;
4801
4802                 dev->cache_last_use = 0;
4803         }
4804
4805         dev->cache_hits = 0;
4806
4807         if (!init_failed) {
4808                 dev->gc_cleanup_list =
4809                     kmalloc(dev->param.chunks_per_block * sizeof(u32),
4810                                         GFP_NOFS);
4811                 if (!dev->gc_cleanup_list)
4812                         init_failed = 1;
4813         }
4814
4815         if (dev->param.is_yaffs2)
4816                 dev->param.use_header_file_size = 1;
4817
4818         if (!init_failed && !yaffs_init_blocks(dev))
4819                 init_failed = 1;
4820
4821         yaffs_init_tnodes_and_objs(dev);
4822
4823         if (!init_failed && !yaffs_create_initial_dir(dev))
4824                 init_failed = 1;
4825
4826         if (!init_failed && dev->param.is_yaffs2 &&
4827                 !dev->param.disable_summary &&
4828                 !yaffs_summary_init(dev))
4829                 init_failed = 1;
4830
4831         if (!init_failed) {
4832                 /* Now scan the flash. */
4833                 if (dev->param.is_yaffs2) {
4834                         if (yaffs2_checkpt_restore(dev)) {
4835                                 yaffs_check_obj_details_loaded(dev->root_dir);
4836                                 yaffs_trace(YAFFS_TRACE_CHECKPOINT |
4837                                         YAFFS_TRACE_MOUNT,
4838                                         "yaffs: restored from checkpoint"
4839                                         );
4840                         } else {
4841
4842                                 /* Clean up the mess caused by an aborted
4843                                  * checkpoint load then scan backwards.
4844                                  */
4845                                 yaffs_deinit_blocks(dev);
4846
4847                                 yaffs_deinit_tnodes_and_objs(dev);
4848
4849                                 dev->n_erased_blocks = 0;
4850                                 dev->n_free_chunks = 0;
4851                                 dev->alloc_block = -1;
4852                                 dev->alloc_page = -1;
4853                                 dev->n_deleted_files = 0;
4854                                 dev->n_unlinked_files = 0;
4855                                 dev->n_bg_deletions = 0;
4856
4857                                 if (!init_failed && !yaffs_init_blocks(dev))
4858                                         init_failed = 1;
4859
4860                                 yaffs_init_tnodes_and_objs(dev);
4861
4862                                 if (!init_failed
4863                                     && !yaffs_create_initial_dir(dev))
4864                                         init_failed = 1;
4865
4866                                 if (!init_failed && !yaffs2_scan_backwards(dev))
4867                                         init_failed = 1;
4868                         }
4869                 } else if (!yaffs1_scan(dev)) {
4870                         init_failed = 1;
4871                 }
4872
4873                 yaffs_strip_deleted_objs(dev);
4874                 yaffs_fix_hanging_objs(dev);
4875                 if (dev->param.empty_lost_n_found)
4876                         yaffs_empty_l_n_f(dev);
4877         }
4878
4879         if (init_failed) {
4880                 /* Clean up the mess */
4881                 yaffs_trace(YAFFS_TRACE_TRACING,
4882                   "yaffs: yaffs_guts_initialise() aborted.");
4883
4884                 yaffs_deinitialise(dev);
4885                 return YAFFS_FAIL;
4886         }
4887
4888         /* Zero out stats */
4889         dev->n_page_reads = 0;
4890         dev->n_page_writes = 0;
4891         dev->n_erasures = 0;
4892         dev->n_gc_copies = 0;
4893         dev->n_retried_writes = 0;
4894
4895         dev->n_retired_blocks = 0;
4896
4897         yaffs_verify_free_chunks(dev);
4898         yaffs_verify_blocks(dev);
4899
4900         /* Clean up any aborted checkpoint data */
4901         if (!dev->is_checkpointed && dev->blocks_in_checkpt > 0)
4902                 yaffs2_checkpt_invalidate(dev);
4903
4904         yaffs_trace(YAFFS_TRACE_TRACING,
4905           "yaffs: yaffs_guts_initialise() done.");
4906         return YAFFS_OK;
4907 }
4908
4909 void yaffs_deinitialise(struct yaffs_dev *dev)
4910 {
4911         if (dev->is_mounted) {
4912                 int i;
4913
4914                 yaffs_deinit_blocks(dev);
4915                 yaffs_deinit_tnodes_and_objs(dev);
4916                 yaffs_summary_deinit(dev);
4917
4918                 if (dev->param.n_caches > 0 && dev->cache) {
4919
4920                         for (i = 0; i < dev->param.n_caches; i++) {
4921                                 kfree(dev->cache[i].data);
4922                                 dev->cache[i].data = NULL;
4923                         }
4924
4925                         kfree(dev->cache);
4926                         dev->cache = NULL;
4927                 }
4928
4929                 kfree(dev->gc_cleanup_list);
4930
4931                 for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++)
4932                         kfree(dev->temp_buffer[i].buffer);
4933
4934                 dev->is_mounted = 0;
4935
4936                 if (dev->param.deinitialise_flash_fn)
4937                         dev->param.deinitialise_flash_fn(dev);
4938         }
4939 }
4940
4941 int yaffs_count_free_chunks(struct yaffs_dev *dev)
4942 {
4943         int n_free = 0;
4944         int b;
4945         struct yaffs_block_info *blk;
4946
4947         blk = dev->block_info;
4948         for (b = dev->internal_start_block; b <= dev->internal_end_block; b++) {
4949                 switch (blk->block_state) {
4950                 case YAFFS_BLOCK_STATE_EMPTY:
4951                 case YAFFS_BLOCK_STATE_ALLOCATING:
4952                 case YAFFS_BLOCK_STATE_COLLECTING:
4953                 case YAFFS_BLOCK_STATE_FULL:
4954                         n_free +=
4955                             (dev->param.chunks_per_block - blk->pages_in_use +
4956                              blk->soft_del_pages);
4957                         break;
4958                 default:
4959                         break;
4960                 }
4961                 blk++;
4962         }
4963         return n_free;
4964 }
4965
4966 int yaffs_get_n_free_chunks(struct yaffs_dev *dev)
4967 {
4968         /* This is what we report to the outside world */
4969         int n_free;
4970         int n_dirty_caches;
4971         int blocks_for_checkpt;
4972         int i;
4973
4974         n_free = dev->n_free_chunks;
4975         n_free += dev->n_deleted_files;
4976
4977         /* Now count and subtract the number of dirty chunks in the cache. */
4978
4979         for (n_dirty_caches = 0, i = 0; i < dev->param.n_caches; i++) {
4980                 if (dev->cache[i].dirty)
4981                         n_dirty_caches++;
4982         }
4983
4984         n_free -= n_dirty_caches;
4985
4986         n_free -=
4987             ((dev->param.n_reserved_blocks + 1) * dev->param.chunks_per_block);
4988
4989         /* Now figure checkpoint space and report that... */
4990         blocks_for_checkpt = yaffs_calc_checkpt_blocks_required(dev);
4991
4992         n_free -= (blocks_for_checkpt * dev->param.chunks_per_block);
4993
4994         if (n_free < 0)
4995                 n_free = 0;
4996
4997         return n_free;
4998 }
4999
5000 /*\
5001  * Marshalling functions to get loff_t file sizes into aand out of
5002  * object headers.
5003  */
5004 void yaffs_oh_size_load(struct yaffs_obj_hdr *oh, loff_t fsize)
5005 {
5006         oh->file_size_low = (fsize & 0xFFFFFFFF);
5007         oh->file_size_high = ((fsize >> 32) & 0xFFFFFFFF);
5008 }
5009
5010 loff_t yaffs_oh_to_size(struct yaffs_obj_hdr *oh)
5011 {
5012         loff_t retval;
5013
5014         if (~(oh->file_size_high))
5015                 retval = (((loff_t) oh->file_size_high) << 32) |
5016                         (((loff_t) oh->file_size_low) & 0xFFFFFFFF);
5017         else
5018                 retval = (loff_t) oh->file_size_low;
5019
5020         return retval;
5021 }