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_tagsmarshall.h"
  21 #include "yaffs_nand.h"
  22 #include "yaffs_yaffs1.h"
  23 #include "yaffs_yaffs2.h"
  24 #include "yaffs_bitmap.h"
  25 #include "yaffs_verify.h"
  26 #include "yaffs_nand.h"
  27 #include "yaffs_packedtags2.h"
  28 #include "yaffs_nameval.h"
  29 #include "yaffs_allocator.h"
  30 #include "yaffs_attribs.h"
  31 #include "yaffs_summary.h"
  32
  33 /* Note YAFFS_GC_GOOD_ENOUGH must be <= YAFFS_GC_PASSIVE_THRESHOLD */
  34 #define YAFFS_GC_GOOD_ENOUGH 2
  35 #define YAFFS_GC_PASSIVE_THRESHOLD 4
  36
  37 #include "yaffs_ecc.h"
  38
  39 /* Forward declarations */
  40
  41 static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
  42                              const u8 *buffer, int n_bytes, int use_reserve);
  43
  44 static void yaffs_fix_null_name(struct yaffs_obj *obj, YCHAR *name,
  45                                 int buffer_size);
  46
  47 /* Function to calculate chunk and offset */
  48
  49 void yaffs_addr_to_chunk(struct yaffs_dev *dev, loff_t addr,
  50                                 int *chunk_out, u32 *offset_out)
  51 {
  52         int chunk;
  53         u32 offset;
  54
  55         chunk = (u32) (addr >> dev->chunk_shift);
  56
  57         if (dev->chunk_div == 1) {
  58                 /* easy power of 2 case */
  59                 offset = (u32) (addr & dev->chunk_mask);
  60         } else {
  61                 /* Non power-of-2 case */
  62
  63                 loff_t chunk_base;
  64
  65                 chunk /= dev->chunk_div;
  66
  67                 chunk_base = ((loff_t) chunk) * dev->data_bytes_per_chunk;
  68                 offset = (u32) (addr - chunk_base);
  69         }
  70
  71         *chunk_out = chunk;
  72         *offset_out = offset;
  73 }
  74
  75 /* Function to return the number of shifts for a power of 2 greater than or
  76  * equal to the given number
  77  * Note we don't try to cater for all possible numbers and this does not have to
  78  * be hellishly efficient.
  79  */
  80
  81 static inline u32 calc_shifts_ceiling(u32 x)
  82 {
  83         int extra_bits;
  84         int shifts;
  85
  86         shifts = extra_bits = 0;
  87
  88         while (x > 1) {
  89                 if (x & 1)
  90                         extra_bits++;
  91                 x >>= 1;
  92                 shifts++;
  93         }
  94
  95         if (extra_bits)
  96                 shifts++;
  97
  98         return shifts;
  99 }
 100
 101 /* Function to return the number of shifts to get a 1 in bit 0
 102  */
 103
 104 static inline u32 calc_shifts(u32 x)
 105 {
 106         u32 shifts;
 107
 108         shifts = 0;
 109
 110         if (!x)
 111                 return 0;
 112
 113         while (!(x & 1)) {
 114                 x >>= 1;
 115                 shifts++;
 116         }
 117
 118         return shifts;
 119 }
 120
 121 /*
 122  * Temporary buffer manipulations.
 123  */
 124
 125 static int yaffs_init_tmp_buffers(struct yaffs_dev *dev)
 126 {
 127         int i;
 128         u8 *buf = (u8 *) 1;
 129
 130         memset(dev->temp_buffer, 0, sizeof(dev->temp_buffer));
 131
 132         for (i = 0; buf && i < YAFFS_N_TEMP_BUFFERS; i++) {
 133                 dev->temp_buffer[i].in_use = 0;
 134                 buf = kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
 135                 dev->temp_buffer[i].buffer = buf;
 136         }
 137
 138         return buf ? YAFFS_OK : YAFFS_FAIL;
 139 }
 140
 141 u8 *yaffs_get_temp_buffer(struct yaffs_dev * dev)
 142 {
 143         int i;
 144
 145         dev->temp_in_use++;
 146         if (dev->temp_in_use > dev->max_temp)
 147                 dev->max_temp = dev->temp_in_use;
 148
 149         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
 150                 if (dev->temp_buffer[i].in_use == 0) {
 151                         dev->temp_buffer[i].in_use = 1;
 152                         return dev->temp_buffer[i].buffer;
 153                 }
 154         }
 155
 156         yaffs_trace(YAFFS_TRACE_BUFFERS, "Out of temp buffers");
 157         /*
 158          * If we got here then we have to allocate an unmanaged one
 159          * This is not good.
 160          */
 161
 162         dev->unmanaged_buffer_allocs++;
 163         return kmalloc(dev->data_bytes_per_chunk, GFP_NOFS);
 164
 165 }
 166
 167 void yaffs_release_temp_buffer(struct yaffs_dev *dev, u8 *buffer)
 168 {
 169         int i;
 170
 171         dev->temp_in_use--;
 172
 173         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
 174                 if (dev->temp_buffer[i].buffer == buffer) {
 175                         dev->temp_buffer[i].in_use = 0;
 176                         return;
 177                 }
 178         }
 179
 180         if (buffer) {
 181                 /* assume it is an unmanaged one. */
 182                 yaffs_trace(YAFFS_TRACE_BUFFERS,
 183                         "Releasing unmanaged temp buffer");
 184                 kfree(buffer);
 185                 dev->unmanaged_buffer_deallocs++;
 186         }
 187
 188 }
 189
 190 /*
 191  * Functions for robustisizing TODO
 192  *
 193  */
 194
 195 static void yaffs_handle_chunk_wr_ok(struct yaffs_dev *dev, int nand_chunk,
 196                                      const u8 *data,
 197                                      const struct yaffs_ext_tags *tags)
 198 {
 199         (void) dev;
 200         (void) nand_chunk;
 201         (void) data;
 202         (void) tags;
 203 }
 204
 205 static void yaffs_handle_chunk_update(struct yaffs_dev *dev, int nand_chunk,
 206                                       const struct yaffs_ext_tags *tags)
 207 {
 208         (void) dev;
 209         (void) nand_chunk;
 210         (void) tags;
 211 }
 212
 213 void yaffs_handle_chunk_error(struct yaffs_dev *dev,
 214                               struct yaffs_block_info *bi)
 215 {
 216         if (!bi->gc_prioritise) {
 217                 bi->gc_prioritise = 1;
 218                 dev->has_pending_prioritised_gc = 1;
 219                 bi->chunk_error_strikes++;
 220
 221                 if (bi->chunk_error_strikes > 3) {
 222                         bi->needs_retiring = 1; /* Too many stikes, so retire */
 223                         yaffs_trace(YAFFS_TRACE_ALWAYS,
 224                                 "yaffs: Block struck out");
 225
 226                 }
 227         }
 228 }
 229
 230 static void yaffs_handle_chunk_wr_error(struct yaffs_dev *dev, int nand_chunk,
 231                                         int erased_ok)
 232 {
 233         int flash_block = nand_chunk / dev->param.chunks_per_block;
 234         struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
 235
 236         yaffs_handle_chunk_error(dev, bi);
 237
 238         if (erased_ok) {
 239                 /* Was an actual write failure,
 240                  * so mark the block for retirement.*/
 241                 bi->needs_retiring = 1;
 242                 yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
 243                   "**>> Block %d needs retiring", flash_block);
 244         }
 245
 246         /* Delete the chunk */
 247         yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
 248         yaffs_skip_rest_of_block(dev);
 249 }
 250
 251 /*
 252  * Verification code
 253  */
 254
 255 /*
 256  *  Simple hash function. Needs to have a reasonable spread
 257  */
 258
 259 static inline int yaffs_hash_fn(int n)
 260 {
 261         if (n < 0)
 262                 n = -n;
 263         return n % YAFFS_NOBJECT_BUCKETS;
 264 }
 265
 266 /*
 267  * Access functions to useful fake objects.
 268  * Note that root might have a presence in NAND if permissions are set.
 269  */
 270
 271 struct yaffs_obj *yaffs_root(struct yaffs_dev *dev)
 272 {
 273         return dev->root_dir;
 274 }
 275
 276 struct yaffs_obj *yaffs_lost_n_found(struct yaffs_dev *dev)
 277 {
 278         return dev->lost_n_found;
 279 }
 280
 281 /*
 282  *  Erased NAND checking functions
 283  */
 284
 285 int yaffs_check_ff(u8 *buffer, int n_bytes)
 286 {
 287         /* Horrible, slow implementation */
 288         while (n_bytes--) {
 289                 if (*buffer != 0xff)
 290                         return 0;
 291                 buffer++;
 292         }
 293         return 1;
 294 }
 295
 296 static int yaffs_check_chunk_erased(struct yaffs_dev *dev, int nand_chunk)
 297 {
 298         int retval = YAFFS_OK;
 299         u8 *data = yaffs_get_temp_buffer(dev);
 300         struct yaffs_ext_tags tags;
 301         int result;
 302
 303         result = yaffs_rd_chunk_tags_nand(dev, nand_chunk, data, &tags);
 304
 305         if (tags.ecc_result > YAFFS_ECC_RESULT_NO_ERROR)
 306                 retval = YAFFS_FAIL;
 307
 308         if (!yaffs_check_ff(data, dev->data_bytes_per_chunk) ||
 309                 tags.chunk_used) {
 310                 yaffs_trace(YAFFS_TRACE_NANDACCESS,
 311                         "Chunk %d not erased", nand_chunk);
 312                 retval = YAFFS_FAIL;
 313         }
 314
 315         yaffs_release_temp_buffer(dev, data);
 316
 317         return retval;
 318
 319 }
 320
 321 static int yaffs_verify_chunk_written(struct yaffs_dev *dev,
 322                                       int nand_chunk,
 323                                       const u8 *data,
 324                                       struct yaffs_ext_tags *tags)
 325 {
 326         int retval = YAFFS_OK;
 327         struct yaffs_ext_tags temp_tags;
 328         u8 *buffer = yaffs_get_temp_buffer(dev);
 329         int result;
 330
 331         result = yaffs_rd_chunk_tags_nand(dev, nand_chunk, buffer, &temp_tags);
 332         if (memcmp(buffer, data, dev->data_bytes_per_chunk) ||
 333             temp_tags.obj_id != tags->obj_id ||
 334             temp_tags.chunk_id != tags->chunk_id ||
 335             temp_tags.n_bytes != tags->n_bytes)
 336                 retval = YAFFS_FAIL;
 337
 338         yaffs_release_temp_buffer(dev, buffer);
 339
 340         return retval;
 341 }
 342
 343
 344 int yaffs_check_alloc_available(struct yaffs_dev *dev, int n_chunks)
 345 {
 346         int reserved_chunks;
 347         int reserved_blocks = dev->param.n_reserved_blocks;
 348         int checkpt_blocks;
 349
 350         checkpt_blocks = yaffs_calc_checkpt_blocks_required(dev);
 351
 352         reserved_chunks =
 353             (reserved_blocks + checkpt_blocks) * dev->param.chunks_per_block;
 354
 355         return (dev->n_free_chunks > (reserved_chunks + n_chunks));
 356 }
 357
 358 static int yaffs_find_alloc_block(struct yaffs_dev *dev)
 359 {
 360         int i;
 361         struct yaffs_block_info *bi;
 362
 363         if (dev->n_erased_blocks < 1) {
 364                 /* Hoosterman we've got a problem.
 365                  * Can't get space to gc
 366                  */
 367                 yaffs_trace(YAFFS_TRACE_ERROR,
 368                   "yaffs tragedy: no more erased blocks");
 369
 370                 return -1;
 371         }
 372
 373         /* Find an empty block. */
 374
 375         for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
 376                 dev->alloc_block_finder++;
 377                 if (dev->alloc_block_finder < dev->internal_start_block
 378                     || dev->alloc_block_finder > dev->internal_end_block) {
 379                         dev->alloc_block_finder = dev->internal_start_block;
 380                 }
 381
 382                 bi = yaffs_get_block_info(dev, dev->alloc_block_finder);
 383
 384                 if (bi->block_state == YAFFS_BLOCK_STATE_EMPTY) {
 385                         bi->block_state = YAFFS_BLOCK_STATE_ALLOCATING;
 386                         dev->seq_number++;
 387                         bi->seq_number = dev->seq_number;
 388                         dev->n_erased_blocks--;
 389                         yaffs_trace(YAFFS_TRACE_ALLOCATE,
 390                           "Allocated block %d, seq  %d, %d left" ,
 391                            dev->alloc_block_finder, dev->seq_number,
 392                            dev->n_erased_blocks);
 393                         return dev->alloc_block_finder;
 394                 }
 395         }
 396
 397         yaffs_trace(YAFFS_TRACE_ALWAYS,
 398                 "yaffs tragedy: no more erased blocks, but there should have been %d",
 399                 dev->n_erased_blocks);
 400
 401         return -1;
 402 }
 403
 404 static int yaffs_alloc_chunk(struct yaffs_dev *dev, int use_reserver,
 405                              struct yaffs_block_info **block_ptr)
 406 {
 407         int ret_val;
 408         struct yaffs_block_info *bi;
 409
 410         if (dev->alloc_block < 0) {
 411                 /* Get next block to allocate off */
 412                 dev->alloc_block = yaffs_find_alloc_block(dev);
 413                 dev->alloc_page = 0;
 414         }
 415
 416         if (!use_reserver && !yaffs_check_alloc_available(dev, 1)) {
 417                 /* No space unless we're allowed to use the reserve. */
 418                 return -1;
 419         }
 420
 421         if (dev->n_erased_blocks < dev->param.n_reserved_blocks
 422             && dev->alloc_page == 0)
 423                 yaffs_trace(YAFFS_TRACE_ALLOCATE, "Allocating reserve");
 424
 425         /* Next page please.... */
 426         if (dev->alloc_block >= 0) {
 427                 bi = yaffs_get_block_info(dev, dev->alloc_block);
 428
 429                 ret_val = (dev->alloc_block * dev->param.chunks_per_block) +
 430                     dev->alloc_page;
 431                 bi->pages_in_use++;
 432                 yaffs_set_chunk_bit(dev, dev->alloc_block, dev->alloc_page);
 433
 434                 dev->alloc_page++;
 435
 436                 dev->n_free_chunks--;
 437
 438                 /* If the block is full set the state to full */
 439                 if (dev->alloc_page >= dev->param.chunks_per_block) {
 440                         bi->block_state = YAFFS_BLOCK_STATE_FULL;
 441                         dev->alloc_block = -1;
 442                 }
 443
 444                 if (block_ptr)
 445                         *block_ptr = bi;
 446
 447                 return ret_val;
 448         }
 449
 450         yaffs_trace(YAFFS_TRACE_ERROR,
 451                 "!!!!!!!!! Allocator out !!!!!!!!!!!!!!!!!");
 452
 453         return -1;
 454 }
 455
 456 static int yaffs_get_erased_chunks(struct yaffs_dev *dev)
 457 {
 458         int n;
 459
 460         n = dev->n_erased_blocks * dev->param.chunks_per_block;
 461
 462         if (dev->alloc_block > 0)
 463                 n += (dev->param.chunks_per_block - dev->alloc_page);
 464
 465         return n;
 466
 467 }
 468
 469 /*
 470  * yaffs_skip_rest_of_block() skips over the rest of the allocation block
 471  * if we don't want to write to it.
 472  */
 473 void yaffs_skip_rest_of_block(struct yaffs_dev *dev)
 474 {
 475         struct yaffs_block_info *bi;
 476
 477         if (dev->alloc_block > 0) {
 478                 bi = yaffs_get_block_info(dev, dev->alloc_block);
 479                 if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING) {
 480                         bi->block_state = YAFFS_BLOCK_STATE_FULL;
 481                         dev->alloc_block = -1;
 482                 }
 483         }
 484 }
 485
 486 static int yaffs_write_new_chunk(struct yaffs_dev *dev,
 487                                  const u8 *data,
 488                                  struct yaffs_ext_tags *tags, int use_reserver)
 489 {
 490         int attempts = 0;
 491         int write_ok = 0;
 492         int chunk;
 493
 494         yaffs2_checkpt_invalidate(dev);
 495
 496         do {
 497                 struct yaffs_block_info *bi = 0;
 498                 int erased_ok = 0;
 499
 500                 chunk = yaffs_alloc_chunk(dev, use_reserver, &bi);
 501                 if (chunk < 0) {
 502                         /* no space */
 503                         break;
 504                 }
 505
 506                 /* First check this chunk is erased, if it needs
 507                  * checking.  The checking policy (unless forced
 508                  * always on) is as follows:
 509                  *
 510                  * Check the first page we try to write in a block.
 511                  * If the check passes then we don't need to check any
 512                  * more.        If the check fails, we check again...
 513                  * If the block has been erased, we don't need to check.
 514                  *
 515                  * However, if the block has been prioritised for gc,
 516                  * then we think there might be something odd about
 517                  * this block and stop using it.
 518                  *
 519                  * Rationale: We should only ever see chunks that have
 520                  * not been erased if there was a partially written
 521                  * chunk due to power loss.  This checking policy should
 522                  * catch that case with very few checks and thus save a
 523                  * lot of checks that are most likely not needed.
 524                  *
 525                  * Mods to the above
 526                  * If an erase check fails or the write fails we skip the
 527                  * rest of the block.
 528                  */
 529
 530                 /* let's give it a try */
 531                 attempts++;
 532
 533                 if (dev->param.always_check_erased)
 534                         bi->skip_erased_check = 0;
 535
 536                 if (!bi->skip_erased_check) {
 537                         erased_ok = yaffs_check_chunk_erased(dev, chunk);
 538                         if (erased_ok != YAFFS_OK) {
 539                                 yaffs_trace(YAFFS_TRACE_ERROR,
 540                                   "**>> yaffs chunk %d was not erased",
 541                                   chunk);
 542
 543                                 /* If not erased, delete this one,
 544                                  * skip rest of block and
 545                                  * try another chunk */
 546                                 yaffs_chunk_del(dev, chunk, 1, __LINE__);
 547                                 yaffs_skip_rest_of_block(dev);
 548                                 continue;
 549                         }
 550                 }
 551
 552                 write_ok = yaffs_wr_chunk_tags_nand(dev, chunk, data, tags);
 553
 554                 if (!bi->skip_erased_check)
 555                         write_ok =
 556                             yaffs_verify_chunk_written(dev, chunk, data, tags);
 557
 558                 if (write_ok != YAFFS_OK) {
 559                         /* Clean up aborted write, skip to next block and
 560                          * try another chunk */
 561                         yaffs_handle_chunk_wr_error(dev, chunk, erased_ok);
 562                         continue;
 563                 }
 564
 565                 bi->skip_erased_check = 1;
 566
 567                 /* Copy the data into the robustification buffer */
 568                 yaffs_handle_chunk_wr_ok(dev, chunk, data, tags);
 569
 570         } while (write_ok != YAFFS_OK &&
 571                  (yaffs_wr_attempts <= 0 || attempts <= yaffs_wr_attempts));
 572
 573         if (!write_ok)
 574                 chunk = -1;
 575
 576         if (attempts > 1) {
 577                 yaffs_trace(YAFFS_TRACE_ERROR,
 578                         "**>> yaffs write required %d attempts",
 579                         attempts);
 580                 dev->n_retried_writes += (attempts - 1);
 581         }
 582
 583         return chunk;
 584 }
 585
 586 /*
 587  * Block retiring for handling a broken block.
 588  */
 589
 590 static void yaffs_retire_block(struct yaffs_dev *dev, int flash_block)
 591 {
 592         struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
 593
 594         yaffs2_checkpt_invalidate(dev);
 595
 596         yaffs2_clear_oldest_dirty_seq(dev, bi);
 597
 598         if (yaffs_mark_bad(dev, flash_block) != YAFFS_OK) {
 599                 if (yaffs_erase_block(dev, flash_block) != YAFFS_OK) {
 600                         yaffs_trace(YAFFS_TRACE_ALWAYS,
 601                                 "yaffs: Failed to mark bad and erase block %d",
 602                                 flash_block);
 603                 } else {
 604                         struct yaffs_ext_tags tags;
 605                         int chunk_id =
 606                             flash_block * dev->param.chunks_per_block;
 607
 608                         u8 *buffer = yaffs_get_temp_buffer(dev);
 609
 610                         memset(buffer, 0xff, dev->data_bytes_per_chunk);
 611                         memset(&tags, 0, sizeof(tags));
 612                         tags.seq_number = YAFFS_SEQUENCE_BAD_BLOCK;
 613                         if (dev->tagger.write_chunk_tags_fn(dev, chunk_id -
 614                                                         dev->chunk_offset,
 615                                                         buffer,
 616                                                         &tags) != YAFFS_OK)
 617                                 yaffs_trace(YAFFS_TRACE_ALWAYS,
 618                                         "yaffs: Failed to write bad block marker to block %d",
 619                                         flash_block);
 620
 621                         yaffs_release_temp_buffer(dev, buffer);
 622                 }
 623         }
 624
 625         bi->block_state = YAFFS_BLOCK_STATE_DEAD;
 626         bi->gc_prioritise = 0;
 627         bi->needs_retiring = 0;
 628
 629         dev->n_retired_blocks++;
 630 }
 631
 632 /*---------------- Name handling functions ------------*/
 633
 634 static u16 yaffs_calc_name_sum(const YCHAR *name)
 635 {
 636         u16 sum = 0;
 637         u16 i = 1;
 638
 639         if (!name)
 640                 return 0;
 641
 642         while ((*name) && i < (YAFFS_MAX_NAME_LENGTH / 2)) {
 643
 644                 /* 0x1f mask is case insensitive */
 645                 sum += ((*name) & 0x1f) * i;
 646                 i++;
 647                 name++;
 648         }
 649         return sum;
 650 }
 651
 652
 653 void yaffs_set_obj_name(struct yaffs_obj *obj, const YCHAR * name)
 654 {
 655         memset(obj->short_name, 0, sizeof(obj->short_name));
 656
 657         if (name && !name[0]) {
 658                 yaffs_fix_null_name(obj, obj->short_name,
 659                                 YAFFS_SHORT_NAME_LENGTH);
 660                 name = obj->short_name;
 661         } else if (name &&
 662                 strnlen(name, YAFFS_SHORT_NAME_LENGTH + 1) <=
 663                 YAFFS_SHORT_NAME_LENGTH)  {
 664                 strcpy(obj->short_name, name);
 665         }
 666
 667         obj->sum = yaffs_calc_name_sum(name);
 668 }
 669
 670 void yaffs_set_obj_name_from_oh(struct yaffs_obj *obj,
 671                                 const struct yaffs_obj_hdr *oh)
 672 {
 673 #ifdef CONFIG_YAFFS_AUTO_UNICODE
 674         YCHAR tmp_name[YAFFS_MAX_NAME_LENGTH + 1];
 675         memset(tmp_name, 0, sizeof(tmp_name));
 676         yaffs_load_name_from_oh(obj->my_dev, tmp_name, oh->name,
 677                                 YAFFS_MAX_NAME_LENGTH + 1);
 678         yaffs_set_obj_name(obj, tmp_name);
 679 #else
 680         yaffs_set_obj_name(obj, oh->name);
 681 #endif
 682 }
 683
 684 loff_t yaffs_max_file_size(struct yaffs_dev *dev)
 685 {
 686         if(sizeof(loff_t) < 8)
 687                 return YAFFS_MAX_FILE_SIZE_32;
 688         else
 689                 return ((loff_t) YAFFS_MAX_CHUNK_ID) * dev->data_bytes_per_chunk;
 690 }
 691
 692 /*-------------------- TNODES -------------------
 693
 694  * List of spare tnodes
 695  * The list is hooked together using the first pointer
 696  * in the tnode.
 697  */
 698
 699 struct yaffs_tnode *yaffs_get_tnode(struct yaffs_dev *dev)
 700 {
 701         struct yaffs_tnode *tn = yaffs_alloc_raw_tnode(dev);
 702
 703         if (tn) {
 704                 memset(tn, 0, dev->tnode_size);
 705                 dev->n_tnodes++;
 706         }
 707
 708         dev->checkpoint_blocks_required = 0;    /* force recalculation */
 709
 710         return tn;
 711 }
 712
 713 /* FreeTnode frees up a tnode and puts it back on the free list */
 714 static void yaffs_free_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
 715 {
 716         yaffs_free_raw_tnode(dev, tn);
 717         dev->n_tnodes--;
 718         dev->checkpoint_blocks_required = 0;    /* force recalculation */
 719 }
 720
 721 static void yaffs_deinit_tnodes_and_objs(struct yaffs_dev *dev)
 722 {
 723         yaffs_deinit_raw_tnodes_and_objs(dev);
 724         dev->n_obj = 0;
 725         dev->n_tnodes = 0;
 726 }
 727
 728 static void yaffs_load_tnode_0(struct yaffs_dev *dev, struct yaffs_tnode *tn,
 729                         unsigned pos, unsigned val)
 730 {
 731         u32 *map = (u32 *) tn;
 732         u32 bit_in_map;
 733         u32 bit_in_word;
 734         u32 word_in_map;
 735         u32 mask;
 736
 737         pos &= YAFFS_TNODES_LEVEL0_MASK;
 738         val >>= dev->chunk_grp_bits;
 739
 740         bit_in_map = pos * dev->tnode_width;
 741         word_in_map = bit_in_map / 32;
 742         bit_in_word = bit_in_map & (32 - 1);
 743
 744         mask = dev->tnode_mask << bit_in_word;
 745
 746         map[word_in_map] &= ~mask;
 747         map[word_in_map] |= (mask & (val << bit_in_word));
 748
 749         if (dev->tnode_width > (32 - bit_in_word)) {
 750                 bit_in_word = (32 - bit_in_word);
 751                 word_in_map++;
 752                 mask =
 753                     dev->tnode_mask >> bit_in_word;
 754                 map[word_in_map] &= ~mask;
 755                 map[word_in_map] |= (mask & (val >> bit_in_word));
 756         }
 757 }
 758
 759 u32 yaffs_get_group_base(struct yaffs_dev *dev, struct yaffs_tnode *tn,
 760                          unsigned pos)
 761 {
 762         u32 *map = (u32 *) tn;
 763         u32 bit_in_map;
 764         u32 bit_in_word;
 765         u32 word_in_map;
 766         u32 val;
 767
 768         pos &= YAFFS_TNODES_LEVEL0_MASK;
 769
 770         bit_in_map = pos * dev->tnode_width;
 771         word_in_map = bit_in_map / 32;
 772         bit_in_word = bit_in_map & (32 - 1);
 773
 774         val = map[word_in_map] >> bit_in_word;
 775
 776         if (dev->tnode_width > (32 - bit_in_word)) {
 777                 bit_in_word = (32 - bit_in_word);
 778                 word_in_map++;
 779                 val |= (map[word_in_map] << bit_in_word);
 780         }
 781
 782         val &= dev->tnode_mask;
 783         val <<= dev->chunk_grp_bits;
 784
 785         return val;
 786 }
 787
 788 /* ------------------- End of individual tnode manipulation -----------------*/
 789
 790 /* ---------Functions to manipulate the look-up tree (made up of tnodes) ------
 791  * The look up tree is represented by the top tnode and the number of top_level
 792  * in the tree. 0 means only the level 0 tnode is in the tree.
 793  */
 794
 795 /* FindLevel0Tnode finds the level 0 tnode, if one exists. */
 796 struct yaffs_tnode *yaffs_find_tnode_0(struct yaffs_dev *dev,
 797                                        struct yaffs_file_var *file_struct,
 798                                        u32 chunk_id)
 799 {
 800         struct yaffs_tnode *tn = file_struct->top;
 801         u32 i;
 802         int required_depth;
 803         int level = file_struct->top_level;
 804
 805         (void) dev;
 806
 807         /* Check sane level and chunk Id */
 808         if (level < 0 || level > YAFFS_TNODES_MAX_LEVEL)
 809                 return NULL;
 810
 811         if (chunk_id > YAFFS_MAX_CHUNK_ID)
 812                 return NULL;
 813
 814         /* First check we're tall enough (ie enough top_level) */
 815
 816         i = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
 817         required_depth = 0;
 818         while (i) {
 819                 i >>= YAFFS_TNODES_INTERNAL_BITS;
 820                 required_depth++;
 821         }
 822
 823         if (required_depth > file_struct->top_level)
 824                 return NULL;    /* Not tall enough, so we can't find it */
 825
 826         /* Traverse down to level 0 */
 827         while (level > 0 && tn) {
 828                 tn = tn->internal[(chunk_id >>
 829                                    (YAFFS_TNODES_LEVEL0_BITS +
 830                                     (level - 1) *
 831                                     YAFFS_TNODES_INTERNAL_BITS)) &
 832                                   YAFFS_TNODES_INTERNAL_MASK];
 833                 level--;
 834         }
 835
 836         return tn;
 837 }
 838
 839 /* add_find_tnode_0 finds the level 0 tnode if it exists,
 840  * otherwise first expands the tree.
 841  * This happens in two steps:
 842  *  1. If the tree isn't tall enough, then make it taller.
 843  *  2. Scan down the tree towards the level 0 tnode adding tnodes if required.
 844  *
 845  * Used when modifying the tree.
 846  *
 847  *  If the tn argument is NULL, then a fresh tnode will be added otherwise the
 848  *  specified tn will be plugged into the ttree.
 849  */
 850
 851 struct yaffs_tnode *yaffs_add_find_tnode_0(struct yaffs_dev *dev,
 852                                            struct yaffs_file_var *file_struct,
 853                                            u32 chunk_id,
 854                                            struct yaffs_tnode *passed_tn)
 855 {
 856         int required_depth;
 857         int i;
 858         int l;
 859         struct yaffs_tnode *tn;
 860         u32 x;
 861
 862         /* Check sane level and page Id */
 863         if (file_struct->top_level < 0 ||
 864             file_struct->top_level > YAFFS_TNODES_MAX_LEVEL)
 865                 return NULL;
 866
 867         if (chunk_id > YAFFS_MAX_CHUNK_ID)
 868                 return NULL;
 869
 870         /* First check we're tall enough (ie enough top_level) */
 871
 872         x = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
 873         required_depth = 0;
 874         while (x) {
 875                 x >>= YAFFS_TNODES_INTERNAL_BITS;
 876                 required_depth++;
 877         }
 878
 879         if (required_depth > file_struct->top_level) {
 880                 /* Not tall enough, gotta make the tree taller */
 881                 for (i = file_struct->top_level; i < required_depth; i++) {
 882
 883                         tn = yaffs_get_tnode(dev);
 884
 885                         if (tn) {
 886                                 tn->internal[0] = file_struct->top;
 887                                 file_struct->top = tn;
 888                                 file_struct->top_level++;
 889                         } else {
 890                                 yaffs_trace(YAFFS_TRACE_ERROR,
 891                                         "yaffs: no more tnodes");
 892                                 return NULL;
 893                         }
 894                 }
 895         }
 896
 897         /* Traverse down to level 0, adding anything we need */
 898
 899         l = file_struct->top_level;
 900         tn = file_struct->top;
 901
 902         if (l > 0) {
 903                 while (l > 0 && tn) {
 904                         x = (chunk_id >>
 905                              (YAFFS_TNODES_LEVEL0_BITS +
 906                               (l - 1) * YAFFS_TNODES_INTERNAL_BITS)) &
 907                             YAFFS_TNODES_INTERNAL_MASK;
 908
 909                         if ((l > 1) && !tn->internal[x]) {
 910                                 /* Add missing non-level-zero tnode */
 911                                 tn->internal[x] = yaffs_get_tnode(dev);
 912                                 if (!tn->internal[x])
 913                                         return NULL;
 914                         } else if (l == 1) {
 915                                 /* Looking from level 1 at level 0 */
 916                                 if (passed_tn) {
 917                                         /* If we already have one, release it */
 918                                         if (tn->internal[x])
 919                                                 yaffs_free_tnode(dev,
 920                                                         tn->internal[x]);
 921                                         tn->internal[x] = passed_tn;
 922
 923                                 } else if (!tn->internal[x]) {
 924                                         /* Don't have one, none passed in */
 925                                         tn->internal[x] = yaffs_get_tnode(dev);
 926                                         if (!tn->internal[x])
 927                                                 return NULL;
 928                                 }
 929                         }
 930
 931                         tn = tn->internal[x];
 932                         l--;
 933                 }
 934         } else {
 935                 /* top is level 0 */
 936                 if (passed_tn) {
 937                         memcpy(tn, passed_tn,
 938                                (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8);
 939                         yaffs_free_tnode(dev, passed_tn);
 940                 }
 941         }
 942
 943         return tn;
 944 }
 945
 946 static int yaffs_tags_match(const struct yaffs_ext_tags *tags, int obj_id,
 947                             int chunk_obj)
 948 {
 949         return (tags->chunk_id == chunk_obj &&
 950                 tags->obj_id == obj_id &&
 951                 !tags->is_deleted) ? 1 : 0;
 952
 953 }
 954
 955 static int yaffs_find_chunk_in_group(struct yaffs_dev *dev, int the_chunk,
 956                                         struct yaffs_ext_tags *tags, int obj_id,
 957                                         int inode_chunk)
 958 {
 959         int j;
 960
 961         for (j = 0; the_chunk && j < dev->chunk_grp_size; j++) {
 962                 if (yaffs_check_chunk_bit
 963                     (dev, the_chunk / dev->param.chunks_per_block,
 964                      the_chunk % dev->param.chunks_per_block)) {
 965
 966                         if (dev->chunk_grp_size == 1)
 967                                 return the_chunk;
 968                         else {
 969                                 yaffs_rd_chunk_tags_nand(dev, the_chunk, NULL,
 970                                                          tags);
 971                                 if (yaffs_tags_match(tags,
 972                                                         obj_id, inode_chunk)) {
 973                                         /* found it; */
 974                                         return the_chunk;
 975                                 }
 976                         }
 977                 }
 978                 the_chunk++;
 979         }
 980         return -1;
 981 }
 982
 983 int yaffs_find_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
 984                                     struct yaffs_ext_tags *tags)
 985 {
 986         /*Get the Tnode, then get the level 0 offset chunk offset */
 987         struct yaffs_tnode *tn;
 988         int the_chunk = -1;
 989         struct yaffs_ext_tags local_tags;
 990         int ret_val = -1;
 991         struct yaffs_dev *dev = in->my_dev;
 992
 993         if (!tags) {
 994                 /* Passed a NULL, so use our own tags space */
 995                 tags = &local_tags;
 996         }
 997
 998         tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
 999
1000         if (!tn)
1001                 return ret_val;
1002
1003         the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
1004
1005         ret_val = yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
1006                                               inode_chunk);
1007         return ret_val;
1008 }
1009
1010 static int yaffs_find_del_file_chunk(struct yaffs_obj *in, int inode_chunk,
1011                                      struct yaffs_ext_tags *tags)
1012 {
1013         /* Get the Tnode, then get the level 0 offset chunk offset */
1014         struct yaffs_tnode *tn;
1015         int the_chunk = -1;
1016         struct yaffs_ext_tags local_tags;
1017         struct yaffs_dev *dev = in->my_dev;
1018         int ret_val = -1;
1019
1020         if (!tags) {
1021                 /* Passed a NULL, so use our own tags space */
1022                 tags = &local_tags;
1023         }
1024
1025         tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
1026
1027         if (!tn)
1028                 return ret_val;
1029
1030         the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
1031
1032         ret_val = yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
1033                                               inode_chunk);
1034
1035         /* Delete the entry in the filestructure (if found) */
1036         if (ret_val != -1)
1037                 yaffs_load_tnode_0(dev, tn, inode_chunk, 0);
1038
1039         return ret_val;
1040 }
1041
1042 int yaffs_put_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
1043                             int nand_chunk, int in_scan)
1044 {
1045         /* NB in_scan is zero unless scanning.
1046          * For forward scanning, in_scan is > 0;
1047          * for backward scanning in_scan is < 0
1048          *
1049          * nand_chunk = 0 is a dummy insert to make sure the tnodes are there.
1050          */
1051
1052         struct yaffs_tnode *tn;
1053         struct yaffs_dev *dev = in->my_dev;
1054         int existing_cunk;
1055         struct yaffs_ext_tags existing_tags;
1056         struct yaffs_ext_tags new_tags;
1057         unsigned existing_serial, new_serial;
1058
1059         if (in->variant_type != YAFFS_OBJECT_TYPE_FILE) {
1060                 /* Just ignore an attempt at putting a chunk into a non-file
1061                  * during scanning.
1062                  * If it is not during Scanning then something went wrong!
1063                  */
1064                 if (!in_scan) {
1065                         yaffs_trace(YAFFS_TRACE_ERROR,
1066                                 "yaffs tragedy:attempt to put data chunk into a non-file"
1067                                 );
1068                         BUG();
1069                 }
1070
1071                 yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
1072                 return YAFFS_OK;
1073         }
1074
1075         tn = yaffs_add_find_tnode_0(dev,
1076                                     &in->variant.file_variant,
1077                                     inode_chunk, NULL);
1078         if (!tn)
1079                 return YAFFS_FAIL;
1080
1081         if (!nand_chunk)
1082                 /* Dummy insert, bail now */
1083                 return YAFFS_OK;
1084
1085         existing_cunk = yaffs_get_group_base(dev, tn, inode_chunk);
1086
1087         if (in_scan != 0) {
1088                 /* If we're scanning then we need to test for duplicates
1089                  * NB This does not need to be efficient since it should only
1090                  * happen when the power fails during a write, then only one
1091                  * chunk should ever be affected.
1092                  *
1093                  * Correction for YAFFS2: This could happen quite a lot and we
1094                  * need to think about efficiency! TODO
1095                  * Update: For backward scanning we don't need to re-read tags
1096                  * so this is quite cheap.
1097                  */
1098
1099                 if (existing_cunk > 0) {
1100                         /* NB Right now existing chunk will not be real
1101                          * chunk_id if the chunk group size > 1
1102                          * thus we have to do a FindChunkInFile to get the
1103                          * real chunk id.
1104                          *
1105                          * We have a duplicate now we need to decide which
1106                          * one to use:
1107                          *
1108                          * Backwards scanning YAFFS2: The old one is what
1109                          * we use, dump the new one.
1110                          * YAFFS1: Get both sets of tags and compare serial
1111                          * numbers.
1112                          */
1113
1114                         if (in_scan > 0) {
1115                                 /* Only do this for forward scanning */
1116                                 yaffs_rd_chunk_tags_nand(dev,
1117                                                          nand_chunk,
1118                                                          NULL, &new_tags);
1119
1120                                 /* Do a proper find */
1121                                 existing_cunk =
1122                                     yaffs_find_chunk_in_file(in, inode_chunk,
1123                                                              &existing_tags);
1124                         }
1125
1126                         if (existing_cunk <= 0) {
1127                                 /*Hoosterman - how did this happen? */
1128
1129                                 yaffs_trace(YAFFS_TRACE_ERROR,
1130                                         "yaffs tragedy: existing chunk < 0 in scan"
1131                                         );
1132
1133                         }
1134
1135                         /* NB The deleted flags should be false, otherwise
1136                          * the chunks will not be loaded during a scan
1137                          */
1138
1139                         if (in_scan > 0) {
1140                                 new_serial = new_tags.serial_number;
1141                                 existing_serial = existing_tags.serial_number;
1142                         }
1143
1144                         if ((in_scan > 0) &&
1145                             (existing_cunk <= 0 ||
1146                              ((existing_serial + 1) & 3) == new_serial)) {
1147                                 /* Forward scanning.
1148                                  * Use new
1149                                  * Delete the old one and drop through to
1150                                  * update the tnode
1151                                  */
1152                                 yaffs_chunk_del(dev, existing_cunk, 1,
1153                                                 __LINE__);
1154                         } else {
1155                                 /* Backward scanning or we want to use the
1156                                  * existing one
1157                                  * Delete the new one and return early so that
1158                                  * the tnode isn't changed
1159                                  */
1160                                 yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
1161                                 return YAFFS_OK;
1162                         }
1163                 }
1164
1165         }
1166
1167         if (existing_cunk == 0)
1168                 in->n_data_chunks++;
1169
1170         yaffs_load_tnode_0(dev, tn, inode_chunk, nand_chunk);
1171
1172         return YAFFS_OK;
1173 }
1174
1175 static void yaffs_soft_del_chunk(struct yaffs_dev *dev, int chunk)
1176 {
1177         struct yaffs_block_info *the_block;
1178         unsigned block_no;
1179
1180         yaffs_trace(YAFFS_TRACE_DELETION, "soft delete chunk %d", chunk);
1181
1182         block_no = chunk / dev->param.chunks_per_block;
1183         the_block = yaffs_get_block_info(dev, block_no);
1184         if (the_block) {
1185                 the_block->soft_del_pages++;
1186                 dev->n_free_chunks++;
1187                 yaffs2_update_oldest_dirty_seq(dev, block_no, the_block);
1188         }
1189 }
1190
1191 /* SoftDeleteWorker scans backwards through the tnode tree and soft deletes all
1192  * the chunks in the file.
1193  * All soft deleting does is increment the block's softdelete count and pulls
1194  * the chunk out of the tnode.
1195  * Thus, essentially this is the same as DeleteWorker except that the chunks
1196  * are soft deleted.
1197  */
1198
1199 static int yaffs_soft_del_worker(struct yaffs_obj *in, struct yaffs_tnode *tn,
1200                                  u32 level, int chunk_offset)
1201 {
1202         int i;
1203         int the_chunk;
1204         int all_done = 1;
1205         struct yaffs_dev *dev = in->my_dev;
1206
1207         if (!tn)
1208                 return 1;
1209
1210         if (level > 0) {
1211                 for (i = YAFFS_NTNODES_INTERNAL - 1;
1212                         all_done && i >= 0;
1213                         i--) {
1214                         if (tn->internal[i]) {
1215                                 all_done =
1216                                     yaffs_soft_del_worker(in,
1217                                         tn->internal[i],
1218                                         level - 1,
1219                                         (chunk_offset <<
1220                                         YAFFS_TNODES_INTERNAL_BITS)
1221                                         + i);
1222                                 if (all_done) {
1223                                         yaffs_free_tnode(dev,
1224                                                 tn->internal[i]);
1225                                         tn->internal[i] = NULL;
1226                                 } else {
1227                                         /* Can this happen? */
1228                                 }
1229                         }
1230                 }
1231                 return (all_done) ? 1 : 0;
1232         }
1233
1234         /* level 0 */
1235          for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0; i--) {
1236                 the_chunk = yaffs_get_group_base(dev, tn, i);
1237                 if (the_chunk) {
1238                         yaffs_soft_del_chunk(dev, the_chunk);
1239                         yaffs_load_tnode_0(dev, tn, i, 0);
1240                 }
1241         }
1242         return 1;
1243 }
1244
1245 static void yaffs_remove_obj_from_dir(struct yaffs_obj *obj)
1246 {
1247         struct yaffs_dev *dev = obj->my_dev;
1248         struct yaffs_obj *parent;
1249
1250         yaffs_verify_obj_in_dir(obj);
1251         parent = obj->parent;
1252
1253         yaffs_verify_dir(parent);
1254
1255         if (dev && dev->param.remove_obj_fn)
1256                 dev->param.remove_obj_fn(obj);
1257
1258         list_del_init(&obj->siblings);
1259         obj->parent = NULL;
1260
1261         yaffs_verify_dir(parent);
1262 }
1263
1264 void yaffs_add_obj_to_dir(struct yaffs_obj *directory, struct yaffs_obj *obj)
1265 {
1266         if (!directory) {
1267                 yaffs_trace(YAFFS_TRACE_ALWAYS,
1268                         "tragedy: Trying to add an object to a null pointer directory"
1269                         );
1270                 BUG();
1271                 return;
1272         }
1273         if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
1274                 yaffs_trace(YAFFS_TRACE_ALWAYS,
1275                         "tragedy: Trying to add an object to a non-directory"
1276                         );
1277                 BUG();
1278         }
1279
1280         if (obj->siblings.prev == NULL) {
1281                 /* Not initialised */
1282                 BUG();
1283         }
1284
1285         yaffs_verify_dir(directory);
1286
1287         yaffs_remove_obj_from_dir(obj);
1288
1289         /* Now add it */
1290         list_add(&obj->siblings, &directory->variant.dir_variant.children);
1291         obj->parent = directory;
1292
1293         if (directory == obj->my_dev->unlinked_dir
1294             || directory == obj->my_dev->del_dir) {
1295                 obj->unlinked = 1;
1296                 obj->my_dev->n_unlinked_files++;
1297                 obj->rename_allowed = 0;
1298         }
1299
1300         yaffs_verify_dir(directory);
1301         yaffs_verify_obj_in_dir(obj);
1302 }
1303
1304 static int yaffs_change_obj_name(struct yaffs_obj *obj,
1305                                  struct yaffs_obj *new_dir,
1306                                  const YCHAR *new_name, int force, int shadows)
1307 {
1308         int unlink_op;
1309         int del_op;
1310         struct yaffs_obj *existing_target;
1311
1312         if (new_dir == NULL)
1313                 new_dir = obj->parent;  /* use the old directory */
1314
1315         if (new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
1316                 yaffs_trace(YAFFS_TRACE_ALWAYS,
1317                         "tragedy: yaffs_change_obj_name: new_dir is not a directory"
1318                         );
1319                 BUG();
1320         }
1321
1322         unlink_op = (new_dir == obj->my_dev->unlinked_dir);
1323         del_op = (new_dir == obj->my_dev->del_dir);
1324
1325         existing_target = yaffs_find_by_name(new_dir, new_name);
1326
1327         /* If the object is a file going into the unlinked directory,
1328          *   then it is OK to just stuff it in since duplicate names are OK.
1329          *   else only proceed if the new name does not exist and we're putting
1330          *   it into a directory.
1331          */
1332         if (!(unlink_op || del_op || force ||
1333               shadows > 0 || !existing_target) ||
1334               new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
1335                 return YAFFS_FAIL;
1336
1337         yaffs_set_obj_name(obj, new_name);
1338         obj->dirty = 1;
1339         yaffs_add_obj_to_dir(new_dir, obj);
1340
1341         if (unlink_op)
1342                 obj->unlinked = 1;
1343
1344         /* If it is a deletion then we mark it as a shrink for gc  */
1345         if (yaffs_update_oh(obj, new_name, 0, del_op, shadows, NULL) >= 0)
1346                 return YAFFS_OK;
1347
1348         return YAFFS_FAIL;
1349 }
1350
1351 /*------------------------ Short Operations Cache ------------------------------
1352  *   In many situations where there is no high level buffering  a lot of
1353  *   reads might be short sequential reads, and a lot of writes may be short
1354  *   sequential writes. eg. scanning/writing a jpeg file.
1355  *   In these cases, a short read/write cache can provide a huge perfomance
1356  *   benefit with dumb-as-a-rock code.
1357  *   In Linux, the page cache provides read buffering and the short op cache
1358  *   provides write buffering.
1359  *
1360  *   There are a small number (~10) of cache chunks per device so that we don't
1361  *   need a very intelligent search.
1362  */
1363
1364 static int yaffs_obj_cache_dirty(struct yaffs_obj *obj)
1365 {
1366         struct yaffs_dev *dev = obj->my_dev;
1367         int i;
1368         struct yaffs_cache *cache;
1369         int n_caches = obj->my_dev->param.n_caches;
1370
1371         for (i = 0; i < n_caches; i++) {
1372                 cache = &dev->cache[i];
1373                 if (cache->object == obj && cache->dirty)
1374                         return 1;
1375         }
1376
1377         return 0;
1378 }
1379
1380 static void yaffs_flush_single_cache(struct yaffs_cache *cache, int discard)
1381 {
1382
1383         if (!cache || cache->locked)
1384                 return;
1385
1386         /* Write it out and free it up  if need be.*/
1387         if (cache->dirty) {
1388                 yaffs_wr_data_obj(cache->object,
1389                                   cache->chunk_id,
1390                                   cache->data,
1391                                   cache->n_bytes,
1392                                   1);
1393
1394                 cache->dirty = 0;
1395         }
1396
1397         if (discard)
1398                 cache->object = NULL;
1399 }
1400
1401 static void yaffs_flush_file_cache(struct yaffs_obj *obj, int discard)
1402 {
1403         struct yaffs_dev *dev = obj->my_dev;
1404         int i;
1405         struct yaffs_cache *cache;
1406         int n_caches = obj->my_dev->param.n_caches;
1407
1408         if (n_caches < 1)
1409                 return;
1410
1411
1412         /* Find the chunks for this object and flush them. */
1413         for (i = 0; i < n_caches; i++) {
1414                 cache = &dev->cache[i];
1415                 if (cache->object == obj)
1416                         yaffs_flush_single_cache(cache, discard);
1417         }
1418
1419 }
1420
1421
1422 void yaffs_flush_whole_cache(struct yaffs_dev *dev, int discard)
1423 {
1424         struct yaffs_obj *obj;
1425         int n_caches = dev->param.n_caches;
1426         int i;
1427
1428         /* Find a dirty object in the cache and flush it...
1429          * until there are no further dirty objects.
1430          */
1431         do {
1432                 obj = NULL;
1433                 for (i = 0; i < n_caches && !obj; i++) {
1434                         if (dev->cache[i].object && dev->cache[i].dirty)
1435                                 obj = dev->cache[i].object;
1436                 }
1437                 if (obj)
1438                         yaffs_flush_file_cache(obj, discard);
1439         } while (obj);
1440
1441 }
1442
1443 /* Grab us an unused cache chunk for use.
1444  * First look for an empty one.
1445  * Then look for the least recently used non-dirty one.
1446  * Then look for the least recently used dirty one...., flush and look again.
1447  */
1448 static struct yaffs_cache *yaffs_grab_chunk_worker(struct yaffs_dev *dev)
1449 {
1450         int i;
1451
1452         if (dev->param.n_caches > 0) {
1453                 for (i = 0; i < dev->param.n_caches; i++) {
1454                         if (!dev->cache[i].object)
1455                                 return &dev->cache[i];
1456                 }
1457         }
1458
1459         return NULL;
1460 }
1461
1462 static struct yaffs_cache *yaffs_grab_chunk_cache(struct yaffs_dev *dev)
1463 {
1464         struct yaffs_cache *cache;
1465         int usage;
1466         int i;
1467
1468         if (dev->param.n_caches < 1)
1469                 return NULL;
1470
1471         /* First look for an unused cache */
1472
1473         cache = yaffs_grab_chunk_worker(dev);
1474
1475         if (cache)
1476                 return cache;
1477
1478         /*
1479          * Thery were all in use.
1480          * Find the LRU cache and flush it if it is dirty.
1481          */
1482
1483         usage = -1;
1484         cache = NULL;
1485
1486         for (i = 0; i < dev->param.n_caches; i++) {
1487                 if (dev->cache[i].object &&
1488                     !dev->cache[i].locked &&
1489                     (dev->cache[i].last_use < usage || !cache)) {
1490                                 usage = dev->cache[i].last_use;
1491                                 cache = &dev->cache[i];
1492                 }
1493         }
1494
1495 #if 1
1496         yaffs_flush_single_cache(cache, 1);
1497 #else
1498         yaffs_flush_file_cache(cache->object, 1);
1499         cache = yaffs_grab_chunk_worker(dev);
1500 #endif
1501
1502         return cache;
1503 }
1504
1505 /* Find a cached chunk */
1506 static struct yaffs_cache *yaffs_find_chunk_cache(const struct yaffs_obj *obj,
1507                                                   int chunk_id)
1508 {
1509         struct yaffs_dev *dev = obj->my_dev;
1510         int i;
1511
1512         if (dev->param.n_caches < 1)
1513                 return NULL;
1514
1515         for (i = 0; i < dev->param.n_caches; i++) {
1516                 if (dev->cache[i].object == obj &&
1517                     dev->cache[i].chunk_id == chunk_id) {
1518                         dev->cache_hits++;
1519
1520                         return &dev->cache[i];
1521                 }
1522         }
1523         return NULL;
1524 }
1525
1526 /* Mark the chunk for the least recently used algorithym */
1527 static void yaffs_use_cache(struct yaffs_dev *dev, struct yaffs_cache *cache,
1528                             int is_write)
1529 {
1530         int i;
1531
1532         if (dev->param.n_caches < 1)
1533                 return;
1534
1535         if (dev->cache_last_use < 0 ||
1536                 dev->cache_last_use > 100000000) {
1537                 /* Reset the cache usages */
1538                 for (i = 1; i < dev->param.n_caches; i++)
1539                         dev->cache[i].last_use = 0;
1540
1541                 dev->cache_last_use = 0;
1542         }
1543         dev->cache_last_use++;
1544         cache->last_use = dev->cache_last_use;
1545
1546         if (is_write)
1547                 cache->dirty = 1;
1548 }
1549
1550 /* Invalidate a single cache page.
1551  * Do this when a whole page gets written,
1552  * ie the short cache for this page is no longer valid.
1553  */
1554 static void yaffs_invalidate_chunk_cache(struct yaffs_obj *object, int chunk_id)
1555 {
1556         struct yaffs_cache *cache;
1557
1558         if (object->my_dev->param.n_caches > 0) {
1559                 cache = yaffs_find_chunk_cache(object, chunk_id);
1560
1561                 if (cache)
1562                         cache->object = NULL;
1563         }
1564 }
1565
1566 /* Invalidate all the cache pages associated with this object
1567  * Do this whenever ther file is deleted or resized.
1568  */
1569 static void yaffs_invalidate_whole_cache(struct yaffs_obj *in)
1570 {
1571         int i;
1572         struct yaffs_dev *dev = in->my_dev;
1573
1574         if (dev->param.n_caches > 0) {
1575                 /* Invalidate it. */
1576                 for (i = 0; i < dev->param.n_caches; i++) {
1577                         if (dev->cache[i].object == in)
1578                                 dev->cache[i].object = NULL;
1579                 }
1580         }
1581 }
1582
1583 static void yaffs_unhash_obj(struct yaffs_obj *obj)
1584 {
1585         int bucket;
1586         struct yaffs_dev *dev = obj->my_dev;
1587
1588         /* If it is still linked into the bucket list, free from the list */
1589         if (!list_empty(&obj->hash_link)) {
1590                 list_del_init(&obj->hash_link);
1591                 bucket = yaffs_hash_fn(obj->obj_id);
1592                 dev->obj_bucket[bucket].count--;
1593         }
1594 }
1595
1596 /*  FreeObject frees up a Object and puts it back on the free list */
1597 static void yaffs_free_obj(struct yaffs_obj *obj)
1598 {
1599         struct yaffs_dev *dev;
1600
1601         if (!obj) {
1602                 BUG();
1603                 return;
1604         }
1605         dev = obj->my_dev;
1606         yaffs_trace(YAFFS_TRACE_OS, "FreeObject %p inode %p",
1607                 obj, obj->my_inode);
1608         if (obj->parent)
1609                 BUG();
1610         if (!list_empty(&obj->siblings))
1611                 BUG();
1612
1613         if (obj->my_inode) {
1614                 /* We're still hooked up to a cached inode.
1615                  * Don't delete now, but mark for later deletion
1616                  */
1617                 obj->defered_free = 1;
1618                 return;
1619         }
1620
1621         yaffs_unhash_obj(obj);
1622
1623         yaffs_free_raw_obj(dev, obj);
1624         dev->n_obj--;
1625         dev->checkpoint_blocks_required = 0;    /* force recalculation */
1626 }
1627
1628 void yaffs_handle_defered_free(struct yaffs_obj *obj)
1629 {
1630         if (obj->defered_free)
1631                 yaffs_free_obj(obj);
1632 }
1633
1634 static int yaffs_generic_obj_del(struct yaffs_obj *in)
1635 {
1636         /* Iinvalidate the file's data in the cache, without flushing. */
1637         yaffs_invalidate_whole_cache(in);
1638
1639         if (in->my_dev->param.is_yaffs2 && in->parent != in->my_dev->del_dir) {
1640                 /* Move to unlinked directory so we have a deletion record */
1641                 yaffs_change_obj_name(in, in->my_dev->del_dir, _Y("deleted"), 0,
1642                                       0);
1643         }
1644
1645         yaffs_remove_obj_from_dir(in);
1646         yaffs_chunk_del(in->my_dev, in->hdr_chunk, 1, __LINE__);
1647         in->hdr_chunk = 0;
1648
1649         yaffs_free_obj(in);
1650         return YAFFS_OK;
1651
1652 }
1653
1654 static void yaffs_soft_del_file(struct yaffs_obj *obj)
1655 {
1656         if (!obj->deleted ||
1657             obj->variant_type != YAFFS_OBJECT_TYPE_FILE ||
1658             obj->soft_del)
1659                 return;
1660
1661         if (obj->n_data_chunks <= 0) {
1662                 /* Empty file with no duplicate object headers,
1663                  * just delete it immediately */
1664                 yaffs_free_tnode(obj->my_dev, obj->variant.file_variant.top);
1665                 obj->variant.file_variant.top = NULL;
1666                 yaffs_trace(YAFFS_TRACE_TRACING,
1667                         "yaffs: Deleting empty file %d",
1668                         obj->obj_id);
1669                 yaffs_generic_obj_del(obj);
1670         } else {
1671                 yaffs_soft_del_worker(obj,
1672                                       obj->variant.file_variant.top,
1673                                       obj->variant.
1674                                       file_variant.top_level, 0);
1675                 obj->soft_del = 1;
1676         }
1677 }
1678
1679 /* Pruning removes any part of the file structure tree that is beyond the
1680  * bounds of the file (ie that does not point to chunks).
1681  *
1682  * A file should only get pruned when its size is reduced.
1683  *
1684  * Before pruning, the chunks must be pulled from the tree and the
1685  * level 0 tnode entries must be zeroed out.
1686  * Could also use this for file deletion, but that's probably better handled
1687  * by a special case.
1688  *
1689  * This function is recursive. For levels > 0 the function is called again on
1690  * any sub-tree. For level == 0 we just check if the sub-tree has data.
1691  * If there is no data in a subtree then it is pruned.
1692  */
1693
1694 static struct yaffs_tnode *yaffs_prune_worker(struct yaffs_dev *dev,
1695                                               struct yaffs_tnode *tn, u32 level,
1696                                               int del0)
1697 {
1698         int i;
1699         int has_data;
1700
1701         if (!tn)
1702                 return tn;
1703
1704         has_data = 0;
1705
1706         if (level > 0) {
1707                 for (i = 0; i < YAFFS_NTNODES_INTERNAL; i++) {
1708                         if (tn->internal[i]) {
1709                                 tn->internal[i] =
1710                                     yaffs_prune_worker(dev,
1711                                                 tn->internal[i],
1712                                                 level - 1,
1713                                                 (i == 0) ? del0 : 1);
1714                         }
1715
1716                         if (tn->internal[i])
1717                                 has_data++;
1718                 }
1719         } else {
1720                 int tnode_size_u32 = dev->tnode_size / sizeof(u32);
1721                 u32 *map = (u32 *) tn;
1722
1723                 for (i = 0; !has_data && i < tnode_size_u32; i++) {
1724                         if (map[i])
1725                                 has_data++;
1726                 }
1727         }
1728
1729         if (has_data == 0 && del0) {
1730                 /* Free and return NULL */
1731                 yaffs_free_tnode(dev, tn);
1732                 tn = NULL;
1733         }
1734         return tn;
1735 }
1736
1737 static int yaffs_prune_tree(struct yaffs_dev *dev,
1738                             struct yaffs_file_var *file_struct)
1739 {
1740         int i;
1741         int has_data;
1742         int done = 0;
1743         struct yaffs_tnode *tn;
1744
1745         if (file_struct->top_level < 1)
1746                 return YAFFS_OK;
1747
1748         file_struct->top =
1749            yaffs_prune_worker(dev, file_struct->top, file_struct->top_level, 0);
1750
1751         /* Now we have a tree with all the non-zero branches NULL but
1752          * the height is the same as it was.
1753          * Let's see if we can trim internal tnodes to shorten the tree.
1754          * We can do this if only the 0th element in the tnode is in use
1755          * (ie all the non-zero are NULL)
1756          */
1757
1758         while (file_struct->top_level && !done) {
1759                 tn = file_struct->top;
1760
1761                 has_data = 0;
1762                 for (i = 1; i < YAFFS_NTNODES_INTERNAL; i++) {
1763                         if (tn->internal[i])
1764                                 has_data++;
1765                 }
1766
1767                 if (!has_data) {
1768                         file_struct->top = tn->internal[0];
1769                         file_struct->top_level--;
1770                         yaffs_free_tnode(dev, tn);
1771                 } else {
1772                         done = 1;
1773                 }
1774         }
1775
1776         return YAFFS_OK;
1777 }
1778
1779 /*-------------------- End of File Structure functions.-------------------*/
1780
1781 /* alloc_empty_obj gets us a clean Object.*/
1782 static struct yaffs_obj *yaffs_alloc_empty_obj(struct yaffs_dev *dev)
1783 {
1784         struct yaffs_obj *obj = yaffs_alloc_raw_obj(dev);
1785
1786         if (!obj)
1787                 return obj;
1788
1789         dev->n_obj++;
1790
1791         /* Now sweeten it up... */
1792
1793         memset(obj, 0, sizeof(struct yaffs_obj));
1794         obj->being_created = 1;
1795
1796         obj->my_dev = dev;
1797         obj->hdr_chunk = 0;
1798         obj->variant_type = YAFFS_OBJECT_TYPE_UNKNOWN;
1799         INIT_LIST_HEAD(&(obj->hard_links));
1800         INIT_LIST_HEAD(&(obj->hash_link));
1801         INIT_LIST_HEAD(&obj->siblings);
1802
1803         /* Now make the directory sane */
1804         if (dev->root_dir) {
1805                 obj->parent = dev->root_dir;
1806                 list_add(&(obj->siblings),
1807                          &dev->root_dir->variant.dir_variant.children);
1808         }
1809
1810         /* Add it to the lost and found directory.
1811          * NB Can't put root or lost-n-found in lost-n-found so
1812          * check if lost-n-found exists first
1813          */
1814         if (dev->lost_n_found)
1815                 yaffs_add_obj_to_dir(dev->lost_n_found, obj);
1816
1817         obj->being_created = 0;
1818
1819         dev->checkpoint_blocks_required = 0;    /* force recalculation */
1820
1821         return obj;
1822 }
1823
1824 static int yaffs_find_nice_bucket(struct yaffs_dev *dev)
1825 {
1826         int i;
1827         int l = 999;
1828         int lowest = 999999;
1829
1830         /* Search for the shortest list or one that
1831          * isn't too long.
1832          */
1833
1834         for (i = 0; i < 10 && lowest > 4; i++) {
1835                 dev->bucket_finder++;
1836                 dev->bucket_finder %= YAFFS_NOBJECT_BUCKETS;
1837                 if (dev->obj_bucket[dev->bucket_finder].count < lowest) {
1838                         lowest = dev->obj_bucket[dev->bucket_finder].count;
1839                         l = dev->bucket_finder;
1840                 }
1841         }
1842
1843         return l;
1844 }
1845
1846 static int yaffs_new_obj_id(struct yaffs_dev *dev)
1847 {
1848         int bucket = yaffs_find_nice_bucket(dev);
1849         int found = 0;
1850         struct list_head *i;
1851         u32 n = (u32) bucket;
1852
1853         /* Now find an object value that has not already been taken
1854          * by scanning the list.
1855          */
1856
1857         while (!found) {
1858                 found = 1;
1859                 n += YAFFS_NOBJECT_BUCKETS;
1860                 if (1 || dev->obj_bucket[bucket].count > 0) {
1861                         list_for_each(i, &dev->obj_bucket[bucket].list) {
1862                                 /* If there is already one in the list */
1863                                 if (i && list_entry(i, struct yaffs_obj,
1864                                                     hash_link)->obj_id == n) {
1865                                         found = 0;
1866                                 }
1867                         }
1868                 }
1869         }
1870         return n;
1871 }
1872
1873 static void yaffs_hash_obj(struct yaffs_obj *in)
1874 {
1875         int bucket = yaffs_hash_fn(in->obj_id);
1876         struct yaffs_dev *dev = in->my_dev;
1877
1878         list_add(&in->hash_link, &dev->obj_bucket[bucket].list);
1879         dev->obj_bucket[bucket].count++;
1880 }
1881
1882 struct yaffs_obj *yaffs_find_by_number(struct yaffs_dev *dev, u32 number)
1883 {
1884         int bucket = yaffs_hash_fn(number);
1885         struct list_head *i;
1886         struct yaffs_obj *in;
1887
1888         list_for_each(i, &dev->obj_bucket[bucket].list) {
1889                 /* Look if it is in the list */
1890                 in = list_entry(i, struct yaffs_obj, hash_link);
1891                 if (in->obj_id == number) {
1892                         /* Don't show if it is defered free */
1893                         if (in->defered_free)
1894                                 return NULL;
1895                         return in;
1896                 }
1897         }
1898
1899         return NULL;
1900 }
1901
1902 static struct yaffs_obj *yaffs_new_obj(struct yaffs_dev *dev, int number,
1903                                 enum yaffs_obj_type type)
1904 {
1905         struct yaffs_obj *the_obj = NULL;
1906         struct yaffs_tnode *tn = NULL;
1907
1908         if (number < 0)
1909                 number = yaffs_new_obj_id(dev);
1910
1911         if (type == YAFFS_OBJECT_TYPE_FILE) {
1912                 tn = yaffs_get_tnode(dev);
1913                 if (!tn)
1914                         return NULL;
1915         }
1916
1917         the_obj = yaffs_alloc_empty_obj(dev);
1918         if (!the_obj) {
1919                 if (tn)
1920                         yaffs_free_tnode(dev, tn);
1921                 return NULL;
1922         }
1923
1924         the_obj->fake = 0;
1925         the_obj->rename_allowed = 1;
1926         the_obj->unlink_allowed = 1;
1927         the_obj->obj_id = number;
1928         yaffs_hash_obj(the_obj);
1929         the_obj->variant_type = type;
1930         yaffs_load_current_time(the_obj, 1, 1);
1931
1932         switch (type) {
1933         case YAFFS_OBJECT_TYPE_FILE:
1934                 the_obj->variant.file_variant.file_size = 0;
1935                 the_obj->variant.file_variant.scanned_size = 0;
1936                 the_obj->variant.file_variant.shrink_size =
1937                                                 yaffs_max_file_size(dev);
1938                 the_obj->variant.file_variant.top_level = 0;
1939                 the_obj->variant.file_variant.top = tn;
1940                 break;
1941         case YAFFS_OBJECT_TYPE_DIRECTORY:
1942                 INIT_LIST_HEAD(&the_obj->variant.dir_variant.children);
1943                 INIT_LIST_HEAD(&the_obj->variant.dir_variant.dirty);
1944                 break;
1945         case YAFFS_OBJECT_TYPE_SYMLINK:
1946         case YAFFS_OBJECT_TYPE_HARDLINK:
1947         case YAFFS_OBJECT_TYPE_SPECIAL:
1948                 /* No action required */
1949                 break;
1950         case YAFFS_OBJECT_TYPE_UNKNOWN:
1951                 /* todo this should not happen */
1952                 break;
1953         }
1954         return the_obj;
1955 }
1956
1957 static struct yaffs_obj *yaffs_create_fake_dir(struct yaffs_dev *dev,
1958                                                int number, u32 mode)
1959 {
1960
1961         struct yaffs_obj *obj =
1962             yaffs_new_obj(dev, number, YAFFS_OBJECT_TYPE_DIRECTORY);
1963
1964         if (!obj)
1965                 return NULL;
1966
1967         obj->fake = 1;  /* it is fake so it might not use NAND */
1968         obj->rename_allowed = 0;
1969         obj->unlink_allowed = 0;
1970         obj->deleted = 0;
1971         obj->unlinked = 0;
1972         obj->yst_mode = mode;
1973         obj->my_dev = dev;
1974         obj->hdr_chunk = 0;     /* Not a valid chunk. */
1975         return obj;
1976
1977 }
1978
1979
1980 static void yaffs_init_tnodes_and_objs(struct yaffs_dev *dev)
1981 {
1982         int i;
1983
1984         dev->n_obj = 0;
1985         dev->n_tnodes = 0;
1986         yaffs_init_raw_tnodes_and_objs(dev);
1987
1988         for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
1989                 INIT_LIST_HEAD(&dev->obj_bucket[i].list);
1990                 dev->obj_bucket[i].count = 0;
1991         }
1992 }
1993
1994 struct yaffs_obj *yaffs_find_or_create_by_number(struct yaffs_dev *dev,
1995                                                  int number,
1996                                                  enum yaffs_obj_type type)
1997 {
1998         struct yaffs_obj *the_obj = NULL;
1999
2000         if (number > 0)
2001                 the_obj = yaffs_find_by_number(dev, number);
2002
2003         if (!the_obj)
2004                 the_obj = yaffs_new_obj(dev, number, type);
2005
2006         return the_obj;
2007
2008 }
2009
2010 YCHAR *yaffs_clone_str(const YCHAR *str)
2011 {
2012         YCHAR *new_str = NULL;
2013         int len;
2014
2015         if (!str)
2016                 str = _Y("");
2017
2018         len = strnlen(str, YAFFS_MAX_ALIAS_LENGTH);
2019         new_str = kmalloc((len + 1) * sizeof(YCHAR), GFP_NOFS);
2020         if (new_str) {
2021                 strncpy(new_str, str, len);
2022                 new_str[len] = 0;
2023         }
2024         return new_str;
2025
2026 }
2027 /*
2028  *yaffs_update_parent() handles fixing a directories mtime and ctime when a new
2029  * link (ie. name) is created or deleted in the directory.
2030  *
2031  * ie.
2032  *   create dir/a : update dir's mtime/ctime
2033  *   rm dir/a:   update dir's mtime/ctime
2034  *   modify dir/a: don't update dir's mtimme/ctime
2035  *
2036  * This can be handled immediately or defered. Defering helps reduce the number
2037  * of updates when many files in a directory are changed within a brief period.
2038  *
2039  * If the directory updating is defered then yaffs_update_dirty_dirs must be
2040  * called periodically.
2041  */
2042
2043 static void yaffs_update_parent(struct yaffs_obj *obj)
2044 {
2045         struct yaffs_dev *dev;
2046
2047         if (!obj)
2048                 return;
2049         dev = obj->my_dev;
2050         obj->dirty = 1;
2051         yaffs_load_current_time(obj, 0, 1);
2052         if (dev->param.defered_dir_update) {
2053                 struct list_head *link = &obj->variant.dir_variant.dirty;
2054
2055                 if (list_empty(link)) {
2056                         list_add(link, &dev->dirty_dirs);
2057                         yaffs_trace(YAFFS_TRACE_BACKGROUND,
2058                           "Added object %d to dirty directories",
2059                            obj->obj_id);
2060                 }
2061
2062         } else {
2063                 yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
2064         }
2065 }
2066
2067 void yaffs_update_dirty_dirs(struct yaffs_dev *dev)
2068 {
2069         struct list_head *link;
2070         struct yaffs_obj *obj;
2071         struct yaffs_dir_var *d_s;
2072         union yaffs_obj_var *o_v;
2073
2074         yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update dirty directories");
2075
2076         while (!list_empty(&dev->dirty_dirs)) {
2077                 link = dev->dirty_dirs.next;
2078                 list_del_init(link);
2079
2080                 d_s = list_entry(link, struct yaffs_dir_var, dirty);
2081                 o_v = list_entry(d_s, union yaffs_obj_var, dir_variant);
2082                 obj = list_entry(o_v, struct yaffs_obj, variant);
2083
2084                 yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update directory %d",
2085                         obj->obj_id);
2086
2087                 if (obj->dirty)
2088                         yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
2089         }
2090 }
2091
2092 /*
2093  * Mknod (create) a new object.
2094  * equiv_obj only has meaning for a hard link;
2095  * alias_str only has meaning for a symlink.
2096  * rdev only has meaning for devices (a subset of special objects)
2097  */
2098
2099 static struct yaffs_obj *yaffs_create_obj(enum yaffs_obj_type type,
2100                                           struct yaffs_obj *parent,
2101                                           const YCHAR *name,
2102                                           u32 mode,
2103                                           u32 uid,
2104                                           u32 gid,
2105                                           struct yaffs_obj *equiv_obj,
2106                                           const YCHAR *alias_str, u32 rdev)
2107 {
2108         struct yaffs_obj *in;
2109         YCHAR *str = NULL;
2110         struct yaffs_dev *dev = parent->my_dev;
2111
2112         /* Check if the entry exists.
2113          * If it does then fail the call since we don't want a dup. */
2114         if (yaffs_find_by_name(parent, name))
2115                 return NULL;
2116
2117         if (type == YAFFS_OBJECT_TYPE_SYMLINK) {
2118                 str = yaffs_clone_str(alias_str);
2119                 if (!str)
2120                         return NULL;
2121         }
2122
2123         in = yaffs_new_obj(dev, -1, type);
2124
2125         if (!in) {
2126                 kfree(str);
2127                 return NULL;
2128         }
2129
2130         in->hdr_chunk = 0;
2131         in->valid = 1;
2132         in->variant_type = type;
2133
2134         in->yst_mode = mode;
2135
2136         yaffs_attribs_init(in, gid, uid, rdev);
2137
2138         in->n_data_chunks = 0;
2139
2140         yaffs_set_obj_name(in, name);
2141         in->dirty = 1;
2142
2143         yaffs_add_obj_to_dir(parent, in);
2144
2145         in->my_dev = parent->my_dev;
2146
2147         switch (type) {
2148         case YAFFS_OBJECT_TYPE_SYMLINK:
2149                 in->variant.symlink_variant.alias = str;
2150                 break;
2151         case YAFFS_OBJECT_TYPE_HARDLINK:
2152                 in->variant.hardlink_variant.equiv_obj = equiv_obj;
2153                 in->variant.hardlink_variant.equiv_id = equiv_obj->obj_id;
2154                 list_add(&in->hard_links, &equiv_obj->hard_links);
2155                 break;
2156         case YAFFS_OBJECT_TYPE_FILE:
2157         case YAFFS_OBJECT_TYPE_DIRECTORY:
2158         case YAFFS_OBJECT_TYPE_SPECIAL:
2159         case YAFFS_OBJECT_TYPE_UNKNOWN:
2160                 /* do nothing */
2161                 break;
2162         }
2163
2164         if (yaffs_update_oh(in, name, 0, 0, 0, NULL) < 0) {
2165                 /* Could not create the object header, fail */
2166                 yaffs_del_obj(in);
2167                 in = NULL;
2168         }
2169
2170         if (in)
2171                 yaffs_update_parent(parent);
2172
2173         return in;
2174 }
2175
2176 struct yaffs_obj *yaffs_create_file(struct yaffs_obj *parent,
2177                                     const YCHAR *name, u32 mode, u32 uid,
2178                                     u32 gid)
2179 {
2180         return yaffs_create_obj(YAFFS_OBJECT_TYPE_FILE, parent, name, mode,
2181                                 uid, gid, NULL, NULL, 0);
2182 }
2183
2184 struct yaffs_obj *yaffs_create_dir(struct yaffs_obj *parent, const YCHAR *name,
2185                                    u32 mode, u32 uid, u32 gid)
2186 {
2187         return yaffs_create_obj(YAFFS_OBJECT_TYPE_DIRECTORY, parent, name,
2188                                 mode, uid, gid, NULL, NULL, 0);
2189 }
2190
2191 struct yaffs_obj *yaffs_create_special(struct yaffs_obj *parent,
2192                                        const YCHAR *name, u32 mode, u32 uid,
2193                                        u32 gid, u32 rdev)
2194 {
2195         return yaffs_create_obj(YAFFS_OBJECT_TYPE_SPECIAL, parent, name, mode,
2196                                 uid, gid, NULL, NULL, rdev);
2197 }
2198
2199 struct yaffs_obj *yaffs_create_symlink(struct yaffs_obj *parent,
2200                                        const YCHAR *name, u32 mode, u32 uid,
2201                                        u32 gid, const YCHAR *alias)
2202 {
2203         return yaffs_create_obj(YAFFS_OBJECT_TYPE_SYMLINK, parent, name, mode,
2204                                 uid, gid, NULL, alias, 0);
2205 }
2206
2207 /* yaffs_link_obj returns the object id of the equivalent object.*/
2208 struct yaffs_obj *yaffs_link_obj(struct yaffs_obj *parent, const YCHAR * name,
2209                                  struct yaffs_obj *equiv_obj)
2210 {
2211         /* Get the real object in case we were fed a hard link obj */
2212         equiv_obj = yaffs_get_equivalent_obj(equiv_obj);
2213
2214         if (yaffs_create_obj(YAFFS_OBJECT_TYPE_HARDLINK,
2215                         parent, name, 0, 0, 0,
2216                         equiv_obj, NULL, 0))
2217                 return equiv_obj;
2218
2219         return NULL;
2220
2221 }
2222
2223
2224
2225 /*---------------------- Block Management and Page Allocation -------------*/
2226
2227 static void yaffs_deinit_blocks(struct yaffs_dev *dev)
2228 {
2229         if (dev->block_info_alt && dev->block_info)
2230                 vfree(dev->block_info);
2231         else
2232                 kfree(dev->block_info);
2233
2234         dev->block_info_alt = 0;
2235
2236         dev->block_info = NULL;
2237
2238         if (dev->chunk_bits_alt && dev->chunk_bits)
2239                 vfree(dev->chunk_bits);
2240         else
2241                 kfree(dev->chunk_bits);
2242         dev->chunk_bits_alt = 0;
2243         dev->chunk_bits = NULL;
2244 }
2245
2246 static int yaffs_init_blocks(struct yaffs_dev *dev)
2247 {
2248         int n_blocks = dev->internal_end_block - dev->internal_start_block + 1;
2249
2250         dev->block_info = NULL;
2251         dev->chunk_bits = NULL;
2252         dev->alloc_block = -1;  /* force it to get a new one */
2253
2254         /* If the first allocation strategy fails, thry the alternate one */
2255         dev->block_info =
2256                 kmalloc(n_blocks * sizeof(struct yaffs_block_info), GFP_NOFS);
2257         if (!dev->block_info) {
2258                 dev->block_info =
2259                     vmalloc(n_blocks * sizeof(struct yaffs_block_info));
2260                 dev->block_info_alt = 1;
2261         } else {
2262                 dev->block_info_alt = 0;
2263         }
2264
2265         if (!dev->block_info)
2266                 goto alloc_error;
2267
2268         /* Set up dynamic blockinfo stuff. Round up bytes. */
2269         dev->chunk_bit_stride = (dev->param.chunks_per_block + 7) / 8;
2270         dev->chunk_bits =
2271                 kmalloc(dev->chunk_bit_stride * n_blocks, GFP_NOFS);
2272         if (!dev->chunk_bits) {
2273                 dev->chunk_bits =
2274                     vmalloc(dev->chunk_bit_stride * n_blocks);
2275                 dev->chunk_bits_alt = 1;
2276         } else {
2277                 dev->chunk_bits_alt = 0;
2278         }
2279         if (!dev->chunk_bits)
2280                 goto alloc_error;
2281
2282
2283         memset(dev->block_info, 0, n_blocks * sizeof(struct yaffs_block_info));
2284         memset(dev->chunk_bits, 0, dev->chunk_bit_stride * n_blocks);
2285         return YAFFS_OK;
2286
2287 alloc_error:
2288         yaffs_deinit_blocks(dev);
2289         return YAFFS_FAIL;
2290 }
2291
2292
2293 void yaffs_block_became_dirty(struct yaffs_dev *dev, int block_no)
2294 {
2295         struct yaffs_block_info *bi = yaffs_get_block_info(dev, block_no);
2296         int erased_ok = 0;
2297         int i;
2298
2299         /* If the block is still healthy erase it and mark as clean.
2300          * If the block has had a data failure, then retire it.
2301          */
2302
2303         yaffs_trace(YAFFS_TRACE_GC | YAFFS_TRACE_ERASE,
2304                 "yaffs_block_became_dirty block %d state %d %s",
2305                 block_no, bi->block_state,
2306                 (bi->needs_retiring) ? "needs retiring" : "");
2307
2308         yaffs2_clear_oldest_dirty_seq(dev, bi);
2309
2310         bi->block_state = YAFFS_BLOCK_STATE_DIRTY;
2311
2312         /* If this is the block being garbage collected then stop gc'ing */
2313         if (block_no == dev->gc_block)
2314                 dev->gc_block = 0;
2315
2316         /* If this block is currently the best candidate for gc
2317          * then drop as a candidate */
2318         if (block_no == dev->gc_dirtiest) {
2319                 dev->gc_dirtiest = 0;
2320                 dev->gc_pages_in_use = 0;
2321         }
2322
2323         if (!bi->needs_retiring) {
2324                 yaffs2_checkpt_invalidate(dev);
2325                 erased_ok = yaffs_erase_block(dev, block_no);
2326                 if (!erased_ok) {
2327                         dev->n_erase_failures++;
2328                         yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2329                           "**>> Erasure failed %d", block_no);
2330                 }
2331         }
2332
2333         /* Verify erasure if needed */
2334         if (erased_ok &&
2335             ((yaffs_trace_mask & YAFFS_TRACE_ERASE) ||
2336              !yaffs_skip_verification(dev))) {
2337                 for (i = 0; i < dev->param.chunks_per_block; i++) {
2338                         if (!yaffs_check_chunk_erased(dev,
2339                                 block_no * dev->param.chunks_per_block + i)) {
2340                                 yaffs_trace(YAFFS_TRACE_ERROR,
2341                                         ">>Block %d erasure supposedly OK, but chunk %d not erased",
2342                                         block_no, i);
2343                         }
2344                 }
2345         }
2346
2347         if (!erased_ok) {
2348                 /* We lost a block of free space */
2349                 dev->n_free_chunks -= dev->param.chunks_per_block;
2350                 yaffs_retire_block(dev, block_no);
2351                 yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2352                         "**>> Block %d retired", block_no);
2353                 return;
2354         }
2355
2356         /* Clean it up... */
2357         bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
2358         bi->seq_number = 0;
2359         dev->n_erased_blocks++;
2360         bi->pages_in_use = 0;
2361         bi->soft_del_pages = 0;
2362         bi->has_shrink_hdr = 0;
2363         bi->skip_erased_check = 1;      /* Clean, so no need to check */
2364         bi->gc_prioritise = 0;
2365         bi->has_summary = 0;
2366
2367         yaffs_clear_chunk_bits(dev, block_no);
2368
2369         yaffs_trace(YAFFS_TRACE_ERASE, "Erased block %d", block_no);
2370 }
2371
2372 static inline int yaffs_gc_process_chunk(struct yaffs_dev *dev,
2373                                         struct yaffs_block_info *bi,
2374                                         int old_chunk, u8 *buffer)
2375 {
2376         int new_chunk;
2377         int mark_flash = 1;
2378         struct yaffs_ext_tags tags;
2379         struct yaffs_obj *object;
2380         int matching_chunk;
2381         int ret_val = YAFFS_OK;
2382
2383         memset(&tags, 0, sizeof(tags));
2384         yaffs_rd_chunk_tags_nand(dev, old_chunk,
2385                                  buffer, &tags);
2386         object = yaffs_find_by_number(dev, tags.obj_id);
2387
2388         yaffs_trace(YAFFS_TRACE_GC_DETAIL,
2389                 "Collecting chunk in block %d, %d %d %d ",
2390                 dev->gc_chunk, tags.obj_id,
2391                 tags.chunk_id, tags.n_bytes);
2392
2393         if (object && !yaffs_skip_verification(dev)) {
2394                 if (tags.chunk_id == 0)
2395                         matching_chunk =
2396                             object->hdr_chunk;
2397                 else if (object->soft_del)
2398                         /* Defeat the test */
2399                         matching_chunk = old_chunk;
2400                 else
2401                         matching_chunk =
2402                             yaffs_find_chunk_in_file
2403                             (object, tags.chunk_id,
2404                              NULL);
2405
2406                 if (old_chunk != matching_chunk)
2407                         yaffs_trace(YAFFS_TRACE_ERROR,
2408                                 "gc: page in gc mismatch: %d %d %d %d",
2409                                 old_chunk,
2410                                 matching_chunk,
2411                                 tags.obj_id,
2412                                 tags.chunk_id);
2413         }
2414
2415         if (!object) {
2416                 yaffs_trace(YAFFS_TRACE_ERROR,
2417                         "page %d in gc has no object: %d %d %d ",
2418                         old_chunk,
2419                         tags.obj_id, tags.chunk_id,
2420                         tags.n_bytes);
2421         }
2422
2423         if (object &&
2424             object->deleted &&
2425             object->soft_del && tags.chunk_id != 0) {
2426                 /* Data chunk in a soft deleted file,
2427                  * throw it away.
2428                  * It's a soft deleted data chunk,
2429                  * No need to copy this, just forget
2430                  * about it and fix up the object.
2431                  */
2432
2433                 /* Free chunks already includes
2434                  * softdeleted chunks, how ever this
2435                  * chunk is going to soon be really
2436                  * deleted which will increment free
2437                  * chunks. We have to decrement free
2438                  * chunks so this works out properly.
2439                  */
2440                 dev->n_free_chunks--;
2441                 bi->soft_del_pages--;
2442
2443                 object->n_data_chunks--;
2444                 if (object->n_data_chunks <= 0) {
2445                         /* remeber to clean up obj */
2446                         dev->gc_cleanup_list[dev->n_clean_ups] = tags.obj_id;
2447                         dev->n_clean_ups++;
2448                 }
2449                 mark_flash = 0;
2450         } else if (object) {
2451                 /* It's either a data chunk in a live
2452                  * file or an ObjectHeader, so we're
2453                  * interested in it.
2454                  * NB Need to keep the ObjectHeaders of
2455                  * deleted files until the whole file
2456                  * has been deleted off
2457                  */
2458                 tags.serial_number++;
2459                 dev->n_gc_copies++;
2460
2461                 if (tags.chunk_id == 0) {
2462                         /* It is an object Id,
2463                          * We need to nuke the
2464                          * shrinkheader flags since its
2465                          * work is done.
2466                          * Also need to clean up
2467                          * shadowing.
2468                          */
2469                         struct yaffs_obj_hdr *oh;
2470                         oh = (struct yaffs_obj_hdr *) buffer;
2471
2472                         oh->is_shrink = 0;
2473                         tags.extra_is_shrink = 0;
2474                         oh->shadows_obj = 0;
2475                         oh->inband_shadowed_obj_id = 0;
2476                         tags.extra_shadows = 0;
2477
2478                         /* Update file size */
2479                         if (object->variant_type == YAFFS_OBJECT_TYPE_FILE) {
2480                                 yaffs_oh_size_load(oh,
2481                                     object->variant.file_variant.file_size);
2482                                 tags.extra_file_size =
2483                                     object->variant.file_variant.file_size;
2484                         }
2485
2486                         yaffs_verify_oh(object, oh, &tags, 1);
2487                         new_chunk =
2488                             yaffs_write_new_chunk(dev, (u8 *) oh, &tags, 1);
2489                 } else {
2490                         new_chunk =
2491                             yaffs_write_new_chunk(dev, buffer, &tags, 1);
2492                 }
2493
2494                 if (new_chunk < 0) {
2495                         ret_val = YAFFS_FAIL;
2496                 } else {
2497
2498                         /* Now fix up the Tnodes etc. */
2499
2500                         if (tags.chunk_id == 0) {
2501                                 /* It's a header */
2502                                 object->hdr_chunk = new_chunk;
2503                                 object->serial = tags.serial_number;
2504                         } else {
2505                                 /* It's a data chunk */
2506                                 yaffs_put_chunk_in_file(object, tags.chunk_id,
2507                                                         new_chunk, 0);
2508                         }
2509                 }
2510         }
2511         if (ret_val == YAFFS_OK)
2512                 yaffs_chunk_del(dev, old_chunk, mark_flash, __LINE__);
2513         return ret_val;
2514 }
2515
2516 static int yaffs_gc_block(struct yaffs_dev *dev, int block, int whole_block)
2517 {
2518         int old_chunk;
2519         int ret_val = YAFFS_OK;
2520         int i;
2521         int is_checkpt_block;
2522         int max_copies;
2523         int chunks_before = yaffs_get_erased_chunks(dev);
2524         int chunks_after;
2525         struct yaffs_block_info *bi = yaffs_get_block_info(dev, block);
2526
2527         is_checkpt_block = (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT);
2528
2529         yaffs_trace(YAFFS_TRACE_TRACING,
2530                 "Collecting block %d, in use %d, shrink %d, whole_block %d",
2531                 block, bi->pages_in_use, bi->has_shrink_hdr,
2532                 whole_block);
2533
2534         /*yaffs_verify_free_chunks(dev); */
2535
2536         if (bi->block_state == YAFFS_BLOCK_STATE_FULL)
2537                 bi->block_state = YAFFS_BLOCK_STATE_COLLECTING;
2538
2539         bi->has_shrink_hdr = 0; /* clear the flag so that the block can erase */
2540
2541         dev->gc_disable = 1;
2542
2543         yaffs_summary_gc(dev, block);
2544
2545         if (is_checkpt_block || !yaffs_still_some_chunks(dev, block)) {
2546                 yaffs_trace(YAFFS_TRACE_TRACING,
2547                         "Collecting block %d that has no chunks in use",
2548                         block);
2549                 yaffs_block_became_dirty(dev, block);
2550         } else {
2551
2552                 u8 *buffer = yaffs_get_temp_buffer(dev);
2553
2554                 yaffs_verify_blk(dev, bi, block);
2555
2556                 max_copies = (whole_block) ? dev->param.chunks_per_block : 5;
2557                 old_chunk = block * dev->param.chunks_per_block + dev->gc_chunk;
2558
2559                 for (/* init already done */ ;
2560                      ret_val == YAFFS_OK &&
2561                      dev->gc_chunk < dev->param.chunks_per_block &&
2562                      (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) &&
2563                      max_copies > 0;
2564                      dev->gc_chunk++, old_chunk++) {
2565                         if (yaffs_check_chunk_bit(dev, block, dev->gc_chunk)) {
2566                                 /* Page is in use and might need to be copied */
2567                                 max_copies--;
2568                                 ret_val = yaffs_gc_process_chunk(dev, bi,
2569                                                         old_chunk, buffer);
2570                         }
2571                 }
2572                 yaffs_release_temp_buffer(dev, buffer);
2573         }
2574
2575         yaffs_verify_collected_blk(dev, bi, block);
2576
2577         if (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
2578                 /*
2579                  * The gc did not complete. Set block state back to FULL
2580                  * because checkpointing does not restore gc.
2581                  */
2582                 bi->block_state = YAFFS_BLOCK_STATE_FULL;
2583         } else {
2584                 /* The gc completed. */
2585                 /* Do any required cleanups */
2586                 for (i = 0; i < dev->n_clean_ups; i++) {
2587                         /* Time to delete the file too */
2588                         struct yaffs_obj *object =
2589                             yaffs_find_by_number(dev, dev->gc_cleanup_list[i]);
2590                         if (object) {
2591                                 yaffs_free_tnode(dev,
2592                                           object->variant.file_variant.top);
2593                                 object->variant.file_variant.top = NULL;
2594                                 yaffs_trace(YAFFS_TRACE_GC,
2595                                         "yaffs: About to finally delete object %d",
2596                                         object->obj_id);
2597                                 yaffs_generic_obj_del(object);
2598                                 object->my_dev->n_deleted_files--;
2599                         }
2600
2601                 }
2602                 chunks_after = yaffs_get_erased_chunks(dev);
2603                 if (chunks_before >= chunks_after)
2604                         yaffs_trace(YAFFS_TRACE_GC,
2605                                 "gc did not increase free chunks before %d after %d",
2606                                 chunks_before, chunks_after);
2607                 dev->gc_block = 0;
2608                 dev->gc_chunk = 0;
2609                 dev->n_clean_ups = 0;
2610         }
2611
2612         dev->gc_disable = 0;
2613
2614         return ret_val;
2615 }
2616
2617 /*
2618  * find_gc_block() selects the dirtiest block (or close enough)
2619  * for garbage collection.
2620  */
2621
2622 static unsigned yaffs_find_gc_block(struct yaffs_dev *dev,
2623                                     int aggressive, int background)
2624 {
2625         int i;
2626         int iterations;
2627         unsigned selected = 0;
2628         int prioritised = 0;
2629         int prioritised_exist = 0;
2630         struct yaffs_block_info *bi;
2631         int threshold;
2632
2633         /* First let's see if we need to grab a prioritised block */
2634         if (dev->has_pending_prioritised_gc && !aggressive) {
2635                 dev->gc_dirtiest = 0;
2636                 bi = dev->block_info;
2637                 for (i = dev->internal_start_block;
2638                      i <= dev->internal_end_block && !selected; i++) {
2639
2640                         if (bi->gc_prioritise) {
2641                                 prioritised_exist = 1;
2642                                 if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
2643                                     yaffs_block_ok_for_gc(dev, bi)) {
2644                                         selected = i;
2645                                         prioritised = 1;
2646                                 }
2647                         }
2648                         bi++;
2649                 }
2650
2651                 /*
2652                  * If there is a prioritised block and none was selected then
2653                  * this happened because there is at least one old dirty block
2654                  * gumming up the works. Let's gc the oldest dirty block.
2655                  */
2656
2657                 if (prioritised_exist &&
2658                     !selected && dev->oldest_dirty_block > 0)
2659                         selected = dev->oldest_dirty_block;
2660
2661                 if (!prioritised_exist) /* None found, so we can clear this */
2662                         dev->has_pending_prioritised_gc = 0;
2663         }
2664
2665         /* If we're doing aggressive GC then we are happy to take a less-dirty
2666          * block, and search harder.
2667          * else (leasurely gc), then we only bother to do this if the
2668          * block has only a few pages in use.
2669          */
2670
2671         if (!selected) {
2672                 int pages_used;
2673                 int n_blocks =
2674                     dev->internal_end_block - dev->internal_start_block + 1;
2675                 if (aggressive) {
2676                         threshold = dev->param.chunks_per_block;
2677                         iterations = n_blocks;
2678                 } else {
2679                         int max_threshold;
2680
2681                         if (background)
2682                                 max_threshold = dev->param.chunks_per_block / 2;
2683                         else
2684                                 max_threshold = dev->param.chunks_per_block / 8;
2685
2686                         if (max_threshold < YAFFS_GC_PASSIVE_THRESHOLD)
2687                                 max_threshold = YAFFS_GC_PASSIVE_THRESHOLD;
2688
2689                         threshold = background ? (dev->gc_not_done + 2) * 2 : 0;
2690                         if (threshold < YAFFS_GC_PASSIVE_THRESHOLD)
2691                                 threshold = YAFFS_GC_PASSIVE_THRESHOLD;
2692                         if (threshold > max_threshold)
2693                                 threshold = max_threshold;
2694
2695                         iterations = n_blocks / 16 + 1;
2696                         if (iterations > 100)
2697                                 iterations = 100;
2698                 }
2699
2700                 for (i = 0;
2701                      i < iterations &&
2702                      (dev->gc_dirtiest < 1 ||
2703                       dev->gc_pages_in_use > YAFFS_GC_GOOD_ENOUGH);
2704                      i++) {
2705                         dev->gc_block_finder++;
2706                         if (dev->gc_block_finder < dev->internal_start_block ||
2707                             dev->gc_block_finder > dev->internal_end_block)
2708                                 dev->gc_block_finder =
2709                                     dev->internal_start_block;
2710
2711                         bi = yaffs_get_block_info(dev, dev->gc_block_finder);
2712
2713                         pages_used = bi->pages_in_use - bi->soft_del_pages;
2714
2715                         if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
2716                             pages_used < dev->param.chunks_per_block &&
2717                             (dev->gc_dirtiest < 1 ||
2718                              pages_used < dev->gc_pages_in_use) &&
2719                             yaffs_block_ok_for_gc(dev, bi)) {
2720                                 dev->gc_dirtiest = dev->gc_block_finder;
2721                                 dev->gc_pages_in_use = pages_used;
2722                         }
2723                 }
2724
2725                 if (dev->gc_dirtiest > 0 && dev->gc_pages_in_use <= threshold)
2726                         selected = dev->gc_dirtiest;
2727         }
2728
2729         /*
2730          * If nothing has been selected for a while, try the oldest dirty
2731          * because that's gumming up the works.
2732          */
2733
2734         if (!selected && dev->param.is_yaffs2 &&
2735             dev->gc_not_done >= (background ? 10 : 20)) {
2736                 yaffs2_find_oldest_dirty_seq(dev);
2737                 if (dev->oldest_dirty_block > 0) {
2738                         selected = dev->oldest_dirty_block;
2739                         dev->gc_dirtiest = selected;
2740                         dev->oldest_dirty_gc_count++;
2741                         bi = yaffs_get_block_info(dev, selected);
2742                         dev->gc_pages_in_use =
2743                             bi->pages_in_use - bi->soft_del_pages;
2744                 } else {
2745                         dev->gc_not_done = 0;
2746                 }
2747         }
2748
2749         if (selected) {
2750                 yaffs_trace(YAFFS_TRACE_GC,
2751                         "GC Selected block %d with %d free, prioritised:%d",
2752                         selected,
2753                         dev->param.chunks_per_block - dev->gc_pages_in_use,
2754                         prioritised);
2755
2756                 dev->n_gc_blocks++;
2757                 if (background)
2758                         dev->bg_gcs++;
2759
2760                 dev->gc_dirtiest = 0;
2761                 dev->gc_pages_in_use = 0;
2762                 dev->gc_not_done = 0;
2763                 if (dev->refresh_skip > 0)
2764                         dev->refresh_skip--;
2765         } else {
2766                 dev->gc_not_done++;
2767                 yaffs_trace(YAFFS_TRACE_GC,
2768                         "GC none: finder %d skip %d threshold %d dirtiest %d using %d oldest %d%s",
2769                         dev->gc_block_finder, dev->gc_not_done, threshold,
2770                         dev->gc_dirtiest, dev->gc_pages_in_use,
2771                         dev->oldest_dirty_block, background ? " bg" : "");
2772         }
2773
2774         return selected;
2775 }
2776
2777 /* New garbage collector
2778  * If we're very low on erased blocks then we do aggressive garbage collection
2779  * otherwise we do "leasurely" garbage collection.
2780  * Aggressive gc looks further (whole array) and will accept less dirty blocks.
2781  * Passive gc only inspects smaller areas and only accepts more dirty blocks.
2782  *
2783  * The idea is to help clear out space in a more spread-out manner.
2784  * Dunno if it really does anything useful.
2785  */
2786 static int yaffs_check_gc(struct yaffs_dev *dev, int background)
2787 {
2788         int aggressive = 0;
2789         int gc_ok = YAFFS_OK;
2790         int max_tries = 0;
2791         int min_erased;
2792         int erased_chunks;
2793         int checkpt_block_adjust;
2794
2795         if (dev->param.gc_control_fn &&
2796                 (dev->param.gc_control_fn(dev) & 1) == 0)
2797                 return YAFFS_OK;
2798
2799         if (dev->gc_disable)
2800                 /* Bail out so we don't get recursive gc */
2801                 return YAFFS_OK;
2802
2803         /* This loop should pass the first time.
2804          * Only loops here if the collection does not increase space.
2805          */
2806
2807         do {
2808                 max_tries++;
2809
2810                 checkpt_block_adjust = yaffs_calc_checkpt_blocks_required(dev);
2811
2812                 min_erased =
2813                     dev->param.n_reserved_blocks + checkpt_block_adjust + 1;
2814                 erased_chunks =
2815                     dev->n_erased_blocks * dev->param.chunks_per_block;
2816
2817                 /* If we need a block soon then do aggressive gc. */
2818                 if (dev->n_erased_blocks < min_erased)
2819                         aggressive = 1;
2820                 else {
2821                         if (!background
2822                             && erased_chunks > (dev->n_free_chunks / 4))
2823                                 break;
2824
2825                         if (dev->gc_skip > 20)
2826                                 dev->gc_skip = 20;
2827                         if (erased_chunks < dev->n_free_chunks / 2 ||
2828                             dev->gc_skip < 1 || background)
2829                                 aggressive = 0;
2830                         else {
2831                                 dev->gc_skip--;
2832                                 break;
2833                         }
2834                 }
2835
2836                 dev->gc_skip = 5;
2837
2838                 /* If we don't already have a block being gc'd then see if we
2839                  * should start another */
2840
2841                 if (dev->gc_block < 1 && !aggressive) {
2842                         dev->gc_block = yaffs2_find_refresh_block(dev);
2843                         dev->gc_chunk = 0;
2844                         dev->n_clean_ups = 0;
2845                 }
2846                 if (dev->gc_block < 1) {
2847                         dev->gc_block =
2848                             yaffs_find_gc_block(dev, aggressive, background);
2849                         dev->gc_chunk = 0;
2850                         dev->n_clean_ups = 0;
2851                 }
2852
2853                 if (dev->gc_block > 0) {
2854                         dev->all_gcs++;
2855                         if (!aggressive)
2856                                 dev->passive_gc_count++;
2857
2858                         yaffs_trace(YAFFS_TRACE_GC,
2859                                 "yaffs: GC n_erased_blocks %d aggressive %d",
2860                                 dev->n_erased_blocks, aggressive);
2861
2862                         gc_ok = yaffs_gc_block(dev, dev->gc_block, aggressive);
2863                 }
2864
2865                 if (dev->n_erased_blocks < (dev->param.n_reserved_blocks) &&
2866                     dev->gc_block > 0) {
2867                         yaffs_trace(YAFFS_TRACE_GC,
2868                                 "yaffs: GC !!!no reclaim!!! n_erased_blocks %d after try %d block %d",
2869                                 dev->n_erased_blocks, max_tries,
2870                                 dev->gc_block);
2871                 }
2872         } while ((dev->n_erased_blocks < dev->param.n_reserved_blocks) &&
2873                  (dev->gc_block > 0) && (max_tries < 2));
2874
2875         return aggressive ? gc_ok : YAFFS_OK;
2876 }
2877
2878 /*
2879  * yaffs_bg_gc()
2880  * Garbage collects. Intended to be called from a background thread.
2881  * Returns non-zero if at least half the free chunks are erased.
2882  */
2883 int yaffs_bg_gc(struct yaffs_dev *dev, unsigned urgency)
2884 {
2885         int erased_chunks = dev->n_erased_blocks * dev->param.chunks_per_block;
2886
2887         yaffs_trace(YAFFS_TRACE_BACKGROUND, "Background gc %u", urgency);
2888
2889         yaffs_check_gc(dev, 1);
2890         return erased_chunks > dev->n_free_chunks / 2;
2891 }
2892
2893 /*-------------------- Data file manipulation -----------------*/
2894
2895 static int yaffs_rd_data_obj(struct yaffs_obj *in, int inode_chunk, u8 * buffer)
2896 {
2897         int nand_chunk = yaffs_find_chunk_in_file(in, inode_chunk, NULL);
2898
2899         if (nand_chunk >= 0)
2900                 return yaffs_rd_chunk_tags_nand(in->my_dev, nand_chunk,
2901                                                 buffer, NULL);
2902         else {
2903                 yaffs_trace(YAFFS_TRACE_NANDACCESS,
2904                         "Chunk %d not found zero instead",
2905                         nand_chunk);
2906                 /* get sane (zero) data if you read a hole */
2907                 memset(buffer, 0, in->my_dev->data_bytes_per_chunk);
2908                 return 0;
2909         }
2910
2911 }
2912
2913 void yaffs_chunk_del(struct yaffs_dev *dev, int chunk_id, int mark_flash,
2914                      int lyn)
2915 {
2916         int block;
2917         int page;
2918         struct yaffs_ext_tags tags;
2919         struct yaffs_block_info *bi;
2920
2921         if (chunk_id <= 0)
2922                 return;
2923
2924         dev->n_deletions++;
2925         block = chunk_id / dev->param.chunks_per_block;
2926         page = chunk_id % dev->param.chunks_per_block;
2927
2928         if (!yaffs_check_chunk_bit(dev, block, page))
2929                 yaffs_trace(YAFFS_TRACE_VERIFY,
2930                         "Deleting invalid chunk %d", chunk_id);
2931
2932         bi = yaffs_get_block_info(dev, block);
2933
2934         yaffs2_update_oldest_dirty_seq(dev, block, bi);
2935
2936         yaffs_trace(YAFFS_TRACE_DELETION,
2937                 "line %d delete of chunk %d",
2938                 lyn, chunk_id);
2939
2940         if (!dev->param.is_yaffs2 && mark_flash &&
2941             bi->block_state != YAFFS_BLOCK_STATE_COLLECTING) {
2942
2943                 memset(&tags, 0, sizeof(tags));
2944                 tags.is_deleted = 1;
2945                 yaffs_wr_chunk_tags_nand(dev, chunk_id, NULL, &tags);
2946                 yaffs_handle_chunk_update(dev, chunk_id, &tags);
2947         } else {
2948                 dev->n_unmarked_deletions++;
2949         }
2950
2951         /* Pull out of the management area.
2952          * If the whole block became dirty, this will kick off an erasure.
2953          */
2954         if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING ||
2955             bi->block_state == YAFFS_BLOCK_STATE_FULL ||
2956             bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCAN ||
2957             bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
2958                 dev->n_free_chunks++;
2959                 yaffs_clear_chunk_bit(dev, block, page);
2960                 bi->pages_in_use--;
2961
2962                 if (bi->pages_in_use == 0 &&
2963                     !bi->has_shrink_hdr &&
2964                     bi->block_state != YAFFS_BLOCK_STATE_ALLOCATING &&
2965                     bi->block_state != YAFFS_BLOCK_STATE_NEEDS_SCAN) {
2966                         yaffs_block_became_dirty(dev, block);
2967                 }
2968         }
2969 }
2970
2971 static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
2972                              const u8 *buffer, int n_bytes, int use_reserve)
2973 {
2974         /* Find old chunk Need to do this to get serial number
2975          * Write new one and patch into tree.
2976          * Invalidate old tags.
2977          */
2978
2979         int prev_chunk_id;
2980         struct yaffs_ext_tags prev_tags;
2981         int new_chunk_id;
2982         struct yaffs_ext_tags new_tags;
2983         struct yaffs_dev *dev = in->my_dev;
2984
2985         yaffs_check_gc(dev, 0);
2986
2987         /* Get the previous chunk at this location in the file if it exists.
2988          * If it does not exist then put a zero into the tree. This creates
2989          * the tnode now, rather than later when it is harder to clean up.
2990          */
2991         prev_chunk_id = yaffs_find_chunk_in_file(in, inode_chunk, &prev_tags);
2992         if (prev_chunk_id < 1 &&
2993             !yaffs_put_chunk_in_file(in, inode_chunk, 0, 0))
2994                 return 0;
2995
2996         /* Set up new tags */
2997         memset(&new_tags, 0, sizeof(new_tags));
2998
2999         new_tags.chunk_id = inode_chunk;
3000         new_tags.obj_id = in->obj_id;
3001         new_tags.serial_number =
3002             (prev_chunk_id > 0) ? prev_tags.serial_number + 1 : 1;
3003         new_tags.n_bytes = n_bytes;
3004
3005         if (n_bytes < 1 || n_bytes > dev->param.total_bytes_per_chunk) {
3006                 yaffs_trace(YAFFS_TRACE_ERROR,
3007                   "Writing %d bytes to chunk!!!!!!!!!",
3008                    n_bytes);
3009                 BUG();
3010         }
3011
3012         new_chunk_id =
3013             yaffs_write_new_chunk(dev, buffer, &new_tags, use_reserve);
3014
3015         if (new_chunk_id > 0) {
3016                 yaffs_put_chunk_in_file(in, inode_chunk, new_chunk_id, 0);
3017
3018                 if (prev_chunk_id > 0)
3019                         yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
3020
3021                 yaffs_verify_file_sane(in);
3022         }
3023         return new_chunk_id;
3024
3025 }
3026
3027
3028
3029 static int yaffs_do_xattrib_mod(struct yaffs_obj *obj, int set,
3030                                 const YCHAR *name, const void *value, int size,
3031                                 int flags)
3032 {
3033         struct yaffs_xattr_mod xmod;
3034         int result;
3035
3036         xmod.set = set;
3037         xmod.name = name;
3038         xmod.data = value;
3039         xmod.size = size;
3040         xmod.flags = flags;
3041         xmod.result = -ENOSPC;
3042
3043         result = yaffs_update_oh(obj, NULL, 0, 0, 0, &xmod);
3044
3045         if (result > 0)
3046                 return xmod.result;
3047         else
3048                 return -ENOSPC;
3049 }
3050
3051 static int yaffs_apply_xattrib_mod(struct yaffs_obj *obj, char *buffer,
3052                                    struct yaffs_xattr_mod *xmod)
3053 {
3054         int retval = 0;
3055         int x_offs = sizeof(struct yaffs_obj_hdr);
3056         struct yaffs_dev *dev = obj->my_dev;
3057         int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
3058         char *x_buffer = buffer + x_offs;
3059
3060         if (xmod->set)
3061                 retval =
3062                     nval_set(x_buffer, x_size, xmod->name, xmod->data,
3063                              xmod->size, xmod->flags);
3064         else
3065                 retval = nval_del(x_buffer, x_size, xmod->name);
3066
3067         obj->has_xattr = nval_hasvalues(x_buffer, x_size);
3068         obj->xattr_known = 1;
3069         xmod->result = retval;
3070
3071         return retval;
3072 }
3073
3074 static int yaffs_do_xattrib_fetch(struct yaffs_obj *obj, const YCHAR *name,
3075                                   void *value, int size)
3076 {
3077         char *buffer = NULL;
3078         int result;
3079         struct yaffs_ext_tags tags;
3080         struct yaffs_dev *dev = obj->my_dev;
3081         int x_offs = sizeof(struct yaffs_obj_hdr);
3082         int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
3083         char *x_buffer;
3084         int retval = 0;
3085
3086         if (obj->hdr_chunk < 1)
3087                 return -ENODATA;
3088
3089         /* If we know that the object has no xattribs then don't do all the
3090          * reading and parsing.
3091          */
3092         if (obj->xattr_known && !obj->has_xattr) {
3093                 if (name)
3094                         return -ENODATA;
3095                 else
3096                         return 0;
3097         }
3098
3099         buffer = (char *)yaffs_get_temp_buffer(dev);
3100         if (!buffer)
3101                 return -ENOMEM;
3102
3103         result =
3104             yaffs_rd_chunk_tags_nand(dev, obj->hdr_chunk, (u8 *) buffer, &tags);
3105
3106         if (result != YAFFS_OK)
3107                 retval = -ENOENT;
3108         else {
3109                 x_buffer = buffer + x_offs;
3110
3111                 if (!obj->xattr_known) {
3112                         obj->has_xattr = nval_hasvalues(x_buffer, x_size);
3113                         obj->xattr_known = 1;
3114                 }
3115
3116                 if (name)
3117                         retval = nval_get(x_buffer, x_size, name, value, size);
3118                 else
3119                         retval = nval_list(x_buffer, x_size, value, size);
3120         }
3121         yaffs_release_temp_buffer(dev, (u8 *) buffer);
3122         return retval;
3123 }
3124
3125 int yaffs_set_xattrib(struct yaffs_obj *obj, const YCHAR * name,
3126                       const void *value, int size, int flags)
3127 {
3128         return yaffs_do_xattrib_mod(obj, 1, name, value, size, flags);
3129 }
3130
3131 int yaffs_remove_xattrib(struct yaffs_obj *obj, const YCHAR * name)
3132 {
3133         return yaffs_do_xattrib_mod(obj, 0, name, NULL, 0, 0);
3134 }
3135
3136 int yaffs_get_xattrib(struct yaffs_obj *obj, const YCHAR * name, void *value,
3137                       int size)
3138 {
3139         return yaffs_do_xattrib_fetch(obj, name, value, size);
3140 }
3141
3142 int yaffs_list_xattrib(struct yaffs_obj *obj, char *buffer, int size)
3143 {
3144         return yaffs_do_xattrib_fetch(obj, NULL, buffer, size);
3145 }
3146
3147 static void yaffs_check_obj_details_loaded(struct yaffs_obj *in)
3148 {
3149         u8 *buf;
3150         struct yaffs_obj_hdr *oh;
3151         struct yaffs_dev *dev;
3152         struct yaffs_ext_tags tags;
3153         int result;
3154         int alloc_failed = 0;
3155
3156         if (!in || !in->lazy_loaded || in->hdr_chunk < 1)
3157                 return;
3158
3159         dev = in->my_dev;
3160         in->lazy_loaded = 0;
3161         buf = yaffs_get_temp_buffer(dev);
3162
3163         result = yaffs_rd_chunk_tags_nand(dev, in->hdr_chunk, buf, &tags);
3164         oh = (struct yaffs_obj_hdr *)buf;
3165
3166         in->yst_mode = oh->yst_mode;
3167         yaffs_load_attribs(in, oh);
3168         yaffs_set_obj_name_from_oh(in, oh);
3169
3170         if (in->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
3171                 in->variant.symlink_variant.alias =
3172                     yaffs_clone_str(oh->alias);
3173                 if (!in->variant.symlink_variant.alias)
3174                         alloc_failed = 1;       /* Not returned */
3175         }
3176         yaffs_release_temp_buffer(dev, buf);
3177 }
3178
3179 static void yaffs_load_name_from_oh(struct yaffs_dev *dev, YCHAR *name,
3180                                     const YCHAR *oh_name, int buff_size)
3181 {
3182 #ifdef CONFIG_YAFFS_AUTO_UNICODE
3183         if (dev->param.auto_unicode) {
3184                 if (*oh_name) {
3185                         /* It is an ASCII name, do an ASCII to
3186                          * unicode conversion */
3187                         const char *ascii_oh_name = (const char *)oh_name;
3188                         int n = buff_size - 1;
3189                         while (n > 0 && *ascii_oh_name) {
3190                                 *name = *ascii_oh_name;
3191                                 name++;
3192                                 ascii_oh_name++;
3193                                 n--;
3194                         }
3195                 } else {
3196                         strncpy(name, oh_name + 1, buff_size - 1);
3197                 }
3198         } else {
3199 #else
3200         (void) dev;
3201         {
3202 #endif
3203                 strncpy(name, oh_name, buff_size - 1);
3204         }
3205 }
3206
3207 static void yaffs_load_oh_from_name(struct yaffs_dev *dev, YCHAR *oh_name,
3208                                     const YCHAR *name)
3209 {
3210 #ifdef CONFIG_YAFFS_AUTO_UNICODE
3211
3212         int is_ascii;
3213         YCHAR *w;
3214
3215         if (dev->param.auto_unicode) {
3216
3217                 is_ascii = 1;
3218                 w = name;
3219
3220                 /* Figure out if the name will fit in ascii character set */
3221                 while (is_ascii && *w) {
3222                         if ((*w) & 0xff00)
3223                                 is_ascii = 0;
3224                         w++;
3225                 }
3226
3227                 if (is_ascii) {
3228                         /* It is an ASCII name, so convert unicode to ascii */
3229                         char *ascii_oh_name = (char *)oh_name;
3230                         int n = YAFFS_MAX_NAME_LENGTH - 1;
3231                         while (n > 0 && *name) {
3232                                 *ascii_oh_name = *name;
3233                                 name++;
3234                                 ascii_oh_name++;
3235                                 n--;
3236                         }
3237                 } else {
3238                         /* Unicode name, so save starting at the second YCHAR */
3239                         *oh_name = 0;
3240                         strncpy(oh_name + 1, name, YAFFS_MAX_NAME_LENGTH - 2);
3241                 }
3242         } else {
3243 #else
3244         dev = dev;
3245         {
3246 #endif
3247                 strncpy(oh_name, name, YAFFS_MAX_NAME_LENGTH - 1);
3248         }
3249 }
3250
3251 /* UpdateObjectHeader updates the header on NAND for an object.
3252  * If name is not NULL, then that new name is used.
3253  */
3254 int yaffs_update_oh(struct yaffs_obj *in, const YCHAR *name, int force,
3255                     int is_shrink, int shadows, struct yaffs_xattr_mod *xmod)
3256 {
3257
3258         struct yaffs_block_info *bi;
3259         struct yaffs_dev *dev = in->my_dev;
3260         int prev_chunk_id;
3261         int ret_val = 0;
3262         int result = 0;
3263         int new_chunk_id;
3264         struct yaffs_ext_tags new_tags;
3265         struct yaffs_ext_tags old_tags;
3266         const YCHAR *alias = NULL;
3267         u8 *buffer = NULL;
3268         YCHAR old_name[YAFFS_MAX_NAME_LENGTH + 1];
3269         struct yaffs_obj_hdr *oh = NULL;
3270         loff_t file_size = 0;
3271
3272         strcpy(old_name, _Y("silly old name"));
3273
3274         if (in->fake && in != dev->root_dir && !force && !xmod)
3275                 return ret_val;
3276
3277         yaffs_check_gc(dev, 0);
3278         yaffs_check_obj_details_loaded(in);
3279
3280         buffer = yaffs_get_temp_buffer(in->my_dev);
3281         oh = (struct yaffs_obj_hdr *)buffer;
3282
3283         prev_chunk_id = in->hdr_chunk;
3284
3285         if (prev_chunk_id > 0) {
3286                 result = yaffs_rd_chunk_tags_nand(dev, prev_chunk_id,
3287                                                   buffer, &old_tags);
3288
3289                 yaffs_verify_oh(in, oh, &old_tags, 0);
3290                 memcpy(old_name, oh->name, sizeof(oh->name));
3291                 memset(buffer, 0xff, sizeof(struct yaffs_obj_hdr));
3292         } else {
3293                 memset(buffer, 0xff, dev->data_bytes_per_chunk);
3294         }
3295
3296         oh->type = in->variant_type;
3297         oh->yst_mode = in->yst_mode;
3298         oh->shadows_obj = oh->inband_shadowed_obj_id = shadows;
3299
3300         yaffs_load_attribs_oh(oh, in);
3301
3302         if (in->parent)
3303                 oh->parent_obj_id = in->parent->obj_id;
3304         else
3305                 oh->parent_obj_id = 0;
3306
3307         if (name && *name) {
3308                 memset(oh->name, 0, sizeof(oh->name));
3309                 yaffs_load_oh_from_name(dev, oh->name, name);
3310         } else if (prev_chunk_id > 0) {
3311                 memcpy(oh->name, old_name, sizeof(oh->name));
3312         } else {
3313                 memset(oh->name, 0, sizeof(oh->name));
3314         }
3315
3316         oh->is_shrink = is_shrink;
3317
3318         switch (in->variant_type) {
3319         case YAFFS_OBJECT_TYPE_UNKNOWN:
3320                 /* Should not happen */
3321                 break;
3322         case YAFFS_OBJECT_TYPE_FILE:
3323                 if (oh->parent_obj_id != YAFFS_OBJECTID_DELETED &&
3324                     oh->parent_obj_id != YAFFS_OBJECTID_UNLINKED)
3325                         file_size = in->variant.file_variant.file_size;
3326                 yaffs_oh_size_load(oh, file_size);
3327                 break;
3328         case YAFFS_OBJECT_TYPE_HARDLINK:
3329                 oh->equiv_id = in->variant.hardlink_variant.equiv_id;
3330                 break;
3331         case YAFFS_OBJECT_TYPE_SPECIAL:
3332                 /* Do nothing */
3333                 break;
3334         case YAFFS_OBJECT_TYPE_DIRECTORY:
3335                 /* Do nothing */
3336                 break;
3337         case YAFFS_OBJECT_TYPE_SYMLINK:
3338                 alias = in->variant.symlink_variant.alias;
3339                 if (!alias)
3340                         alias = _Y("no alias");
3341                 strncpy(oh->alias, alias, YAFFS_MAX_ALIAS_LENGTH);
3342                 oh->alias[YAFFS_MAX_ALIAS_LENGTH] = 0;
3343                 break;
3344         }
3345
3346         /* process any xattrib modifications */
3347         if (xmod)
3348                 yaffs_apply_xattrib_mod(in, (char *)buffer, xmod);
3349
3350         /* Tags */
3351         memset(&new_tags, 0, sizeof(new_tags));
3352         in->serial++;
3353         new_tags.chunk_id = 0;
3354         new_tags.obj_id = in->obj_id;
3355         new_tags.serial_number = in->serial;
3356
3357         /* Add extra info for file header */
3358         new_tags.extra_available = 1;
3359         new_tags.extra_parent_id = oh->parent_obj_id;
3360         new_tags.extra_file_size = file_size;
3361         new_tags.extra_is_shrink = oh->is_shrink;
3362         new_tags.extra_equiv_id = oh->equiv_id;
3363         new_tags.extra_shadows = (oh->shadows_obj > 0) ? 1 : 0;
3364         new_tags.extra_obj_type = in->variant_type;
3365         yaffs_verify_oh(in, oh, &new_tags, 1);
3366
3367         /* Create new chunk in NAND */
3368         new_chunk_id =
3369             yaffs_write_new_chunk(dev, buffer, &new_tags,
3370                                   (prev_chunk_id > 0) ? 1 : 0);
3371
3372         if (buffer)
3373                 yaffs_release_temp_buffer(dev, buffer);
3374
3375         if (new_chunk_id < 0)
3376                 return new_chunk_id;
3377
3378         in->hdr_chunk = new_chunk_id;
3379
3380         if (prev_chunk_id > 0)
3381                 yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
3382
3383         if (!yaffs_obj_cache_dirty(in))
3384                 in->dirty = 0;
3385
3386         /* If this was a shrink, then mark the block
3387          * that the chunk lives on */
3388         if (is_shrink) {
3389                 bi = yaffs_get_block_info(in->my_dev,
3390                                           new_chunk_id /
3391                                           in->my_dev->param.chunks_per_block);
3392                 bi->has_shrink_hdr = 1;
3393         }
3394
3395
3396         return new_chunk_id;
3397 }
3398
3399 /*--------------------- File read/write ------------------------
3400  * Read and write have very similar structures.
3401  * In general the read/write has three parts to it
3402  * An incomplete chunk to start with (if the read/write is not chunk-aligned)
3403  * Some complete chunks
3404  * An incomplete chunk to end off with
3405  *
3406  * Curve-balls: the first chunk might also be the last chunk.
3407  */
3408
3409 int yaffs_file_rd(struct yaffs_obj *in, u8 * buffer, loff_t offset, int n_bytes)
3410 {
3411         int chunk;
3412         u32 start;
3413         int n_copy;
3414         int n = n_bytes;
3415         int n_done = 0;
3416         struct yaffs_cache *cache;
3417         struct yaffs_dev *dev;
3418
3419         dev = in->my_dev;
3420
3421         while (n > 0) {
3422                 yaffs_addr_to_chunk(dev, offset, &chunk, &start);
3423                 chunk++;
3424
3425                 /* OK now check for the curveball where the start and end are in
3426                  * the same chunk.
3427                  */
3428                 if ((start + n) < dev->data_bytes_per_chunk)
3429                         n_copy = n;
3430                 else
3431                         n_copy = dev->data_bytes_per_chunk - start;
3432
3433                 cache = yaffs_find_chunk_cache(in, chunk);
3434
3435                 /* If the chunk is already in the cache or it is less than
3436                  * a whole chunk or we're using inband tags then use the cache
3437                  * (if there is caching) else bypass the cache.
3438                  */
3439                 if (cache || n_copy != dev->data_bytes_per_chunk ||
3440                     dev->param.inband_tags) {
3441                         if (dev->param.n_caches > 0) {
3442
3443                                 /* If we can't find the data in the cache,
3444                                  * then load it up. */
3445
3446                                 if (!cache) {
3447                                         cache =
3448                                             yaffs_grab_chunk_cache(in->my_dev);
3449                                         cache->object = in;
3450                                         cache->chunk_id = chunk;
3451                                         cache->dirty = 0;
3452                                         cache->locked = 0;
3453                                         yaffs_rd_data_obj(in, chunk,
3454                                                           cache->data);
3455                                         cache->n_bytes = 0;
3456                                 }
3457
3458                                 yaffs_use_cache(dev, cache, 0);
3459
3460                                 cache->locked = 1;
3461
3462                                 memcpy(buffer, &cache->data[start], n_copy);
3463
3464                                 cache->locked = 0;
3465                         } else {
3466                                 /* Read into the local buffer then copy.. */
3467
3468                                 u8 *local_buffer =
3469                                     yaffs_get_temp_buffer(dev);
3470                                 yaffs_rd_data_obj(in, chunk, local_buffer);
3471
3472                                 memcpy(buffer, &local_buffer[start], n_copy);
3473
3474                                 yaffs_release_temp_buffer(dev, local_buffer);
3475                         }
3476                 } else {
3477                         /* A full chunk. Read directly into the buffer. */
3478                         yaffs_rd_data_obj(in, chunk, buffer);
3479                 }
3480                 n -= n_copy;
3481                 offset += n_copy;
3482                 buffer += n_copy;
3483                 n_done += n_copy;
3484         }
3485         return n_done;
3486 }
3487
3488 int yaffs_do_file_wr(struct yaffs_obj *in, const u8 *buffer, loff_t offset,
3489                      int n_bytes, int write_through)
3490 {
3491
3492         int chunk;
3493         u32 start;
3494         int n_copy;
3495         int n = n_bytes;
3496         int n_done = 0;
3497         int n_writeback;
3498         loff_t start_write = offset;
3499         int chunk_written = 0;
3500         u32 n_bytes_read;
3501         loff_t chunk_start;
3502         struct yaffs_dev *dev;
3503
3504         dev = in->my_dev;
3505
3506         while (n > 0 && chunk_written >= 0) {
3507                 yaffs_addr_to_chunk(dev, offset, &chunk, &start);
3508
3509                 if (((loff_t)chunk) *
3510                     dev->data_bytes_per_chunk + start != offset ||
3511                     start >= dev->data_bytes_per_chunk) {
3512                         yaffs_trace(YAFFS_TRACE_ERROR,
3513                                 "AddrToChunk of offset %lld gives chunk %d start %d",
3514                                 offset, chunk, start);
3515                 }
3516                 chunk++;        /* File pos to chunk in file offset */
3517
3518                 /* OK now check for the curveball where the start and end are in
3519                  * the same chunk.
3520                  */
3521
3522                 if ((start + n) < dev->data_bytes_per_chunk) {
3523                         n_copy = n;
3524
3525                         /* Now calculate how many bytes to write back....
3526                          * If we're overwriting and not writing to then end of
3527                          * file then we need to write back as much as was there
3528                          * before.
3529                          */
3530
3531                         chunk_start = (((loff_t)(chunk - 1)) *
3532                                         dev->data_bytes_per_chunk);
3533
3534                         if (chunk_start > in->variant.file_variant.file_size)
3535                                 n_bytes_read = 0;       /* Past end of file */
3536                         else
3537                                 n_bytes_read =
3538                                     in->variant.file_variant.file_size -
3539                                     chunk_start;
3540
3541                         if (n_bytes_read > dev->data_bytes_per_chunk)
3542                                 n_bytes_read = dev->data_bytes_per_chunk;
3543
3544                         n_writeback =
3545                             (n_bytes_read >
3546                              (start + n)) ? n_bytes_read : (start + n);
3547
3548                         if (n_writeback < 0 ||
3549                             n_writeback > dev->data_bytes_per_chunk)
3550                                 BUG();
3551
3552                 } else {
3553                         n_copy = dev->data_bytes_per_chunk - start;
3554                         n_writeback = dev->data_bytes_per_chunk;
3555                 }
3556
3557                 if (n_copy != dev->data_bytes_per_chunk ||
3558                     !dev->param.cache_bypass_aligned ||
3559                     dev->param.inband_tags) {
3560                         /* An incomplete start or end chunk (or maybe both
3561                          * start and end chunk), or we're using inband tags,
3562                          * or we're forcing writes through the cache,
3563                          * so we want to use the cache buffers.
3564                          */
3565                         if (dev->param.n_caches > 0) {
3566                                 struct yaffs_cache *cache;
3567
3568                                 /* If we can't find the data in the cache, then
3569                                  * load the cache */
3570                                 cache = yaffs_find_chunk_cache(in, chunk);
3571
3572                                 if (!cache &&
3573                                     yaffs_check_alloc_available(dev, 1)) {
3574                                         cache = yaffs_grab_chunk_cache(dev);
3575                                         cache->object = in;
3576                                         cache->chunk_id = chunk;
3577                                         cache->dirty = 0;
3578                                         cache->locked = 0;
3579                                         yaffs_rd_data_obj(in, chunk,
3580                                                           cache->data);
3581                                 } else if (cache &&
3582                                            !cache->dirty &&
3583                                            !yaffs_check_alloc_available(dev,
3584                                                                         1)) {
3585                                         /* Drop the cache if it was a read cache
3586                                          * item and no space check has been made
3587                                          * for it.
3588                                          */
3589                                         cache = NULL;
3590                                 }
3591
3592                                 if (cache) {
3593                                         yaffs_use_cache(dev, cache, 1);
3594                                         cache->locked = 1;
3595
3596                                         memcpy(&cache->data[start], buffer,
3597                                                n_copy);
3598
3599                                         cache->locked = 0;
3600                                         cache->n_bytes = n_writeback;
3601
3602                                         if (write_through) {
3603                                                 chunk_written =
3604                                                     yaffs_wr_data_obj
3605                                                     (cache->object,
3606                                                      cache->chunk_id,
3607                                                      cache->data,
3608                                                      cache->n_bytes, 1);
3609                                                 cache->dirty = 0;
3610                                         }
3611                                 } else {
3612                                         chunk_written = -1;     /* fail write */
3613                                 }
3614                         } else {
3615                                 /* An incomplete start or end chunk (or maybe
3616                                  * both start and end chunk). Read into the
3617                                  * local buffer then copy over and write back.
3618                                  */
3619
3620                                 u8 *local_buffer = yaffs_get_temp_buffer(dev);
3621
3622                                 yaffs_rd_data_obj(in, chunk, local_buffer);
3623                                 memcpy(&local_buffer[start], buffer, n_copy);
3624
3625                                 chunk_written =
3626                                     yaffs_wr_data_obj(in, chunk,
3627                                                       local_buffer,
3628                                                       n_writeback, 0);
3629
3630                                 yaffs_release_temp_buffer(dev, local_buffer);
3631                         }
3632                 } else {
3633                         /* A full chunk. Write directly from the buffer. */
3634
3635                         chunk_written =
3636                             yaffs_wr_data_obj(in, chunk, buffer,
3637                                               dev->data_bytes_per_chunk, 0);
3638
3639                         /* Since we've overwritten the cached data,
3640                          * we better invalidate it. */
3641                         yaffs_invalidate_chunk_cache(in, chunk);
3642                 }
3643
3644                 if (chunk_written >= 0) {
3645                         n -= n_copy;
3646                         offset += n_copy;
3647                         buffer += n_copy;
3648                         n_done += n_copy;
3649                 }
3650         }
3651
3652         /* Update file object */
3653
3654         if ((start_write + n_done) > in->variant.file_variant.file_size)
3655                 in->variant.file_variant.file_size = (start_write + n_done);
3656
3657         in->dirty = 1;
3658         return n_done;
3659 }
3660
3661 int yaffs_wr_file(struct yaffs_obj *in, const u8 *buffer, loff_t offset,
3662                   int n_bytes, int write_through)
3663 {
3664         yaffs2_handle_hole(in, offset);
3665         return yaffs_do_file_wr(in, buffer, offset, n_bytes, write_through);
3666 }
3667
3668 /* ---------------------- File resizing stuff ------------------ */
3669
3670 static void yaffs_prune_chunks(struct yaffs_obj *in, loff_t new_size)
3671 {
3672
3673         struct yaffs_dev *dev = in->my_dev;
3674         loff_t old_size = in->variant.file_variant.file_size;
3675         int i;
3676         int chunk_id;
3677         u32 dummy;
3678         int last_del;
3679         int start_del;
3680
3681         if (old_size > 0)
3682                 yaffs_addr_to_chunk(dev, old_size - 1, &last_del, &dummy);
3683         else
3684                 last_del = 0;
3685
3686         yaffs_addr_to_chunk(dev, new_size + dev->data_bytes_per_chunk - 1,
3687                                 &start_del, &dummy);
3688         last_del++;
3689         start_del++;
3690
3691         /* Delete backwards so that we don't end up with holes if
3692          * power is lost part-way through the operation.
3693          */
3694         for (i = last_del; i >= start_del; i--) {
3695                 /* NB this could be optimised somewhat,
3696                  * eg. could retrieve the tags and write them without
3697                  * using yaffs_chunk_del
3698                  */
3699
3700                 chunk_id = yaffs_find_del_file_chunk(in, i, NULL);
3701
3702                 if (chunk_id < 1)
3703                         continue;
3704
3705                 if (chunk_id <
3706                     (dev->internal_start_block * dev->param.chunks_per_block) ||
3707                     chunk_id >=
3708                     ((dev->internal_end_block + 1) *
3709                       dev->param.chunks_per_block)) {
3710                         yaffs_trace(YAFFS_TRACE_ALWAYS,
3711                                 "Found daft chunk_id %d for %d",
3712                                 chunk_id, i);
3713                 } else {
3714                         in->n_data_chunks--;
3715                         yaffs_chunk_del(dev, chunk_id, 1, __LINE__);
3716                 }
3717         }
3718 }
3719
3720 void yaffs_resize_file_down(struct yaffs_obj *obj, loff_t new_size)
3721 {
3722         int new_full;
3723         u32 new_partial;
3724         struct yaffs_dev *dev = obj->my_dev;
3725
3726         yaffs_addr_to_chunk(dev, new_size, &new_full, &new_partial);
3727
3728         yaffs_prune_chunks(obj, new_size);
3729
3730         if (new_partial != 0) {
3731                 int last_chunk = 1 + new_full;
3732                 u8 *local_buffer = yaffs_get_temp_buffer(dev);
3733
3734                 /* Rewrite the last chunk with its new size and zero pad */
3735                 yaffs_rd_data_obj(obj, last_chunk, local_buffer);
3736                 memset(local_buffer + new_partial, 0,
3737                        dev->data_bytes_per_chunk - new_partial);
3738
3739                 yaffs_wr_data_obj(obj, last_chunk, local_buffer,
3740                                   new_partial, 1);
3741
3742                 yaffs_release_temp_buffer(dev, local_buffer);
3743         }
3744
3745         obj->variant.file_variant.file_size = new_size;
3746
3747         yaffs_prune_tree(dev, &obj->variant.file_variant);
3748 }
3749
3750 int yaffs_resize_file(struct yaffs_obj *in, loff_t new_size)
3751 {
3752         struct yaffs_dev *dev = in->my_dev;
3753         loff_t old_size = in->variant.file_variant.file_size;
3754
3755         yaffs_flush_file_cache(in, 1);
3756         yaffs_invalidate_whole_cache(in);
3757
3758         yaffs_check_gc(dev, 0);
3759
3760         if (in->variant_type != YAFFS_OBJECT_TYPE_FILE)
3761                 return YAFFS_FAIL;
3762
3763         if (new_size == old_size)
3764                 return YAFFS_OK;
3765
3766         if (new_size > old_size) {
3767                 yaffs2_handle_hole(in, new_size);
3768                 in->variant.file_variant.file_size = new_size;
3769         } else {
3770                 /* new_size < old_size */
3771                 yaffs_resize_file_down(in, new_size);
3772         }
3773
3774         /* Write a new object header to reflect the resize.
3775          * show we've shrunk the file, if need be
3776          * Do this only if the file is not in the deleted directories
3777          * and is not shadowed.
3778          */
3779         if (in->parent &&
3780             !in->is_shadowed &&
3781             in->parent->obj_id != YAFFS_OBJECTID_UNLINKED &&
3782             in->parent->obj_id != YAFFS_OBJECTID_DELETED)
3783                 yaffs_update_oh(in, NULL, 0, 0, 0, NULL);
3784
3785         return YAFFS_OK;
3786 }
3787
3788 int yaffs_flush_file(struct yaffs_obj *in,
3789                      int update_time,
3790                      int data_sync,
3791                      int discard_cache)
3792 {
3793         if (!in->dirty)
3794                 return YAFFS_OK;
3795
3796         yaffs_flush_file_cache(in, discard_cache);
3797
3798         if (data_sync)
3799                 return YAFFS_OK;
3800
3801         if (update_time)
3802                 yaffs_load_current_time(in, 0, 0);
3803
3804         return (yaffs_update_oh(in, NULL, 0, 0, 0, NULL) >= 0) ?
3805                                 YAFFS_OK : YAFFS_FAIL;
3806 }
3807
3808
3809 /* yaffs_del_file deletes the whole file data
3810  * and the inode associated with the file.
3811  * It does not delete the links associated with the file.
3812  */
3813 static int yaffs_unlink_file_if_needed(struct yaffs_obj *in)
3814 {
3815         int ret_val;
3816         int del_now = 0;
3817         struct yaffs_dev *dev = in->my_dev;
3818
3819         if (!in->my_inode)
3820                 del_now = 1;
3821
3822         if (del_now) {
3823                 ret_val =
3824                     yaffs_change_obj_name(in, in->my_dev->del_dir,
3825                                           _Y("deleted"), 0, 0);
3826                 yaffs_trace(YAFFS_TRACE_TRACING,
3827                         "yaffs: immediate deletion of file %d",
3828                         in->obj_id);
3829                 in->deleted = 1;
3830                 in->my_dev->n_deleted_files++;
3831                 if (dev->param.disable_soft_del || dev->param.is_yaffs2)
3832                         yaffs_resize_file(in, 0);
3833                 yaffs_soft_del_file(in);
3834         } else {
3835                 ret_val =
3836                     yaffs_change_obj_name(in, in->my_dev->unlinked_dir,
3837                                           _Y("unlinked"), 0, 0);
3838         }
3839         return ret_val;
3840 }
3841
3842 static int yaffs_del_file(struct yaffs_obj *in)
3843 {
3844         int ret_val = YAFFS_OK;
3845         int deleted;    /* Need to cache value on stack if in is freed */
3846         struct yaffs_dev *dev = in->my_dev;
3847
3848         if (dev->param.disable_soft_del || dev->param.is_yaffs2)
3849                 yaffs_resize_file(in, 0);
3850
3851         if (in->n_data_chunks > 0) {
3852                 /* Use soft deletion if there is data in the file.
3853                  * That won't be the case if it has been resized to zero.
3854                  */
3855                 if (!in->unlinked)
3856                         ret_val = yaffs_unlink_file_if_needed(in);
3857
3858                 deleted = in->deleted;
3859
3860                 if (ret_val == YAFFS_OK && in->unlinked && !in->deleted) {
3861                         in->deleted = 1;
3862                         deleted = 1;
3863                         in->my_dev->n_deleted_files++;
3864                         yaffs_soft_del_file(in);
3865                 }
3866                 return deleted ? YAFFS_OK : YAFFS_FAIL;
3867         } else {
3868                 /* The file has no data chunks so we toss it immediately */
3869                 yaffs_free_tnode(in->my_dev, in->variant.file_variant.top);
3870                 in->variant.file_variant.top = NULL;
3871                 yaffs_generic_obj_del(in);
3872
3873                 return YAFFS_OK;
3874         }
3875 }
3876
3877 int yaffs_is_non_empty_dir(struct yaffs_obj *obj)
3878 {
3879         return (obj &&
3880                 obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY) &&
3881                 !(list_empty(&obj->variant.dir_variant.children));
3882 }
3883
3884 static int yaffs_del_dir(struct yaffs_obj *obj)
3885 {
3886         /* First check that the directory is empty. */
3887         if (yaffs_is_non_empty_dir(obj))
3888                 return YAFFS_FAIL;
3889
3890         return yaffs_generic_obj_del(obj);
3891 }
3892
3893 static int yaffs_del_symlink(struct yaffs_obj *in)
3894 {
3895         kfree(in->variant.symlink_variant.alias);
3896         in->variant.symlink_variant.alias = NULL;
3897
3898         return yaffs_generic_obj_del(in);
3899 }
3900
3901 static int yaffs_del_link(struct yaffs_obj *in)
3902 {
3903         /* remove this hardlink from the list associated with the equivalent
3904          * object
3905          */
3906         list_del_init(&in->hard_links);
3907         return yaffs_generic_obj_del(in);
3908 }
3909
3910 int yaffs_del_obj(struct yaffs_obj *obj)
3911 {
3912         int ret_val = -1;
3913
3914         switch (obj->variant_type) {
3915         case YAFFS_OBJECT_TYPE_FILE:
3916                 ret_val = yaffs_del_file(obj);
3917                 break;
3918         case YAFFS_OBJECT_TYPE_DIRECTORY:
3919                 if (!list_empty(&obj->variant.dir_variant.dirty)) {
3920                         yaffs_trace(YAFFS_TRACE_BACKGROUND,
3921                                 "Remove object %d from dirty directories",
3922                                 obj->obj_id);
3923                         list_del_init(&obj->variant.dir_variant.dirty);
3924                 }
3925                 return yaffs_del_dir(obj);
3926                 break;
3927         case YAFFS_OBJECT_TYPE_SYMLINK:
3928                 ret_val = yaffs_del_symlink(obj);
3929                 break;
3930         case YAFFS_OBJECT_TYPE_HARDLINK:
3931                 ret_val = yaffs_del_link(obj);
3932                 break;
3933         case YAFFS_OBJECT_TYPE_SPECIAL:
3934                 ret_val = yaffs_generic_obj_del(obj);
3935                 break;
3936         case YAFFS_OBJECT_TYPE_UNKNOWN:
3937                 ret_val = 0;
3938                 break;          /* should not happen. */
3939         }
3940         return ret_val;
3941 }
3942
3943
3944 static void yaffs_empty_dir_to_dir(struct yaffs_obj *from_dir,
3945                                    struct yaffs_obj *to_dir)
3946 {
3947         struct yaffs_obj *obj;
3948         struct list_head *lh;
3949         struct list_head *n;
3950
3951         list_for_each_safe(lh, n, &from_dir->variant.dir_variant.children) {
3952                 obj = list_entry(lh, struct yaffs_obj, siblings);
3953                 yaffs_add_obj_to_dir(to_dir, obj);
3954         }
3955 }
3956
3957 struct yaffs_obj *yaffs_retype_obj(struct yaffs_obj *obj,
3958                                    enum yaffs_obj_type type)
3959 {
3960         /* Tear down the old variant */
3961         switch (obj->variant_type) {
3962         case YAFFS_OBJECT_TYPE_FILE:
3963                 /* Nuke file data */
3964                 yaffs_resize_file(obj, 0);
3965                 yaffs_free_tnode(obj->my_dev, obj->variant.file_variant.top);
3966                 obj->variant.file_variant.top = NULL;
3967                 break;
3968         case YAFFS_OBJECT_TYPE_DIRECTORY:
3969                 /* Put the children in lost and found. */
3970                 yaffs_empty_dir_to_dir(obj, obj->my_dev->lost_n_found);
3971                 if (!list_empty(&obj->variant.dir_variant.dirty))
3972                         list_del_init(&obj->variant.dir_variant.dirty);
3973                 break;
3974         case YAFFS_OBJECT_TYPE_SYMLINK:
3975                 /* Nuke symplink data */
3976                 kfree(obj->variant.symlink_variant.alias);
3977                 obj->variant.symlink_variant.alias = NULL;
3978                 break;
3979         case YAFFS_OBJECT_TYPE_HARDLINK:
3980                 list_del_init(&obj->hard_links);
3981                 break;
3982         default:
3983                 break;
3984         }
3985
3986         memset(&obj->variant, 0, sizeof(obj->variant));
3987
3988         /*Set up new variant if the memset is not enough. */
3989         switch (type) {
3990         case YAFFS_OBJECT_TYPE_DIRECTORY:
3991                 INIT_LIST_HEAD(&obj->variant.dir_variant.children);
3992                 INIT_LIST_HEAD(&obj->variant.dir_variant.dirty);
3993                 break;
3994         case YAFFS_OBJECT_TYPE_FILE:
3995         case YAFFS_OBJECT_TYPE_SYMLINK:
3996         case YAFFS_OBJECT_TYPE_HARDLINK:
3997         default:
3998                 break;
3999         }
4000
4001         obj->variant_type = type;
4002
4003         return obj;
4004
4005 }
4006
4007 static int yaffs_unlink_worker(struct yaffs_obj *obj)
4008 {
4009         int del_now = 0;
4010
4011         if (!obj)
4012                 return YAFFS_FAIL;
4013
4014         if (!obj->my_inode)
4015                 del_now = 1;
4016
4017         yaffs_update_parent(obj->parent);
4018
4019         if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
4020                 return yaffs_del_link(obj);
4021         } else if (!list_empty(&obj->hard_links)) {
4022                 /* Curve ball: We're unlinking an object that has a hardlink.
4023                  *
4024                  * This problem arises because we are not strictly following
4025                  * The Linux link/inode model.
4026                  *
4027                  * We can't really delete the object.
4028                  * Instead, we do the following:
4029                  * - Select a hardlink.
4030                  * - Unhook it from the hard links
4031                  * - Move it from its parent directory so that the rename works.
4032                  * - Rename the object to the hardlink's name.
4033                  * - Delete the hardlink
4034                  */
4035
4036                 struct yaffs_obj *hl;
4037                 struct yaffs_obj *parent;
4038                 int ret_val;
4039                 YCHAR name[YAFFS_MAX_NAME_LENGTH + 1];
4040
4041                 hl = list_entry(obj->hard_links.next, struct yaffs_obj,
4042                                 hard_links);
4043
4044                 yaffs_get_obj_name(hl, name, YAFFS_MAX_NAME_LENGTH + 1);
4045                 parent = hl->parent;
4046
4047                 list_del_init(&hl->hard_links);
4048
4049                 yaffs_add_obj_to_dir(obj->my_dev->unlinked_dir, hl);
4050
4051                 ret_val = yaffs_change_obj_name(obj, parent, name, 0, 0);
4052
4053                 if (ret_val == YAFFS_OK)
4054                         ret_val = yaffs_generic_obj_del(hl);
4055
4056                 return ret_val;
4057
4058         } else if (del_now) {
4059                 switch (obj->variant_type) {
4060                 case YAFFS_OBJECT_TYPE_FILE:
4061                         return yaffs_del_file(obj);
4062                         break;
4063                 case YAFFS_OBJECT_TYPE_DIRECTORY:
4064                         list_del_init(&obj->variant.dir_variant.dirty);
4065                         return yaffs_del_dir(obj);
4066                         break;
4067                 case YAFFS_OBJECT_TYPE_SYMLINK:
4068                         return yaffs_del_symlink(obj);
4069                         break;
4070                 case YAFFS_OBJECT_TYPE_SPECIAL:
4071                         return yaffs_generic_obj_del(obj);
4072                         break;
4073                 case YAFFS_OBJECT_TYPE_HARDLINK:
4074                 case YAFFS_OBJECT_TYPE_UNKNOWN:
4075                 default:
4076                         return YAFFS_FAIL;
4077                 }
4078         } else if (yaffs_is_non_empty_dir(obj)) {
4079                 return YAFFS_FAIL;
4080         } else {
4081                 return yaffs_change_obj_name(obj, obj->my_dev->unlinked_dir,
4082                                                 _Y("unlinked"), 0, 0);
4083         }
4084 }
4085
4086 static int yaffs_unlink_obj(struct yaffs_obj *obj)
4087 {
4088         if (obj && obj->unlink_allowed)
4089                 return yaffs_unlink_worker(obj);
4090
4091         return YAFFS_FAIL;
4092 }
4093
4094 int yaffs_unlinker(struct yaffs_obj *dir, const YCHAR *name)
4095 {
4096         struct yaffs_obj *obj;
4097
4098         obj = yaffs_find_by_name(dir, name);
4099         return yaffs_unlink_obj(obj);
4100 }
4101
4102 /* Note:
4103  * If old_name is NULL then we take old_dir as the object to be renamed.
4104  */
4105 int yaffs_rename_obj(struct yaffs_obj *old_dir, const YCHAR *old_name,
4106                      struct yaffs_obj *new_dir, const YCHAR *new_name)
4107 {
4108         struct yaffs_obj *obj = NULL;
4109         struct yaffs_obj *existing_target = NULL;
4110         int force = 0;
4111         int result;
4112         struct yaffs_dev *dev;
4113
4114         if (!old_dir || old_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4115                 BUG();
4116                 return YAFFS_FAIL;
4117         }
4118         if (!new_dir || new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4119                 BUG();
4120                 return YAFFS_FAIL;
4121         }
4122
4123         dev = old_dir->my_dev;
4124
4125 #ifdef CONFIG_YAFFS_CASE_INSENSITIVE
4126         /* Special case for case insemsitive systems.
4127          * While look-up is case insensitive, the name isn't.
4128          * Therefore we might want to change x.txt to X.txt
4129          */
4130         if (old_dir == new_dir &&
4131                 old_name && new_name &&
4132                 strcmp(old_name, new_name) == 0)
4133                 force = 1;
4134 #endif
4135
4136         if (strnlen(new_name, YAFFS_MAX_NAME_LENGTH + 1) >
4137             YAFFS_MAX_NAME_LENGTH)
4138                 /* ENAMETOOLONG */
4139                 return YAFFS_FAIL;
4140
4141         if (old_name)
4142                 obj = yaffs_find_by_name(old_dir, old_name);
4143         else{
4144                 obj = old_dir;
4145                 old_dir = obj->parent;
4146         }
4147
4148         if (obj && obj->rename_allowed) {
4149                 /* Now handle an existing target, if there is one */
4150                 existing_target = yaffs_find_by_name(new_dir, new_name);
4151                 if (yaffs_is_non_empty_dir(existing_target)) {
4152                         return YAFFS_FAIL;      /* ENOTEMPTY */
4153                 } else if (existing_target && existing_target != obj) {
4154                         /* Nuke the target first, using shadowing,
4155                          * but only if it isn't the same object.
4156                          *
4157                          * Note we must disable gc here otherwise it can mess
4158                          * up the shadowing.
4159                          *
4160                          */
4161                         dev->gc_disable = 1;
4162                         yaffs_change_obj_name(obj, new_dir, new_name, force,
4163                                               existing_target->obj_id);
4164                         existing_target->is_shadowed = 1;
4165                         yaffs_unlink_obj(existing_target);
4166                         dev->gc_disable = 0;
4167                 }
4168
4169                 result = yaffs_change_obj_name(obj, new_dir, new_name, 1, 0);
4170
4171                 yaffs_update_parent(old_dir);
4172                 if (new_dir != old_dir)
4173                         yaffs_update_parent(new_dir);
4174
4175                 return result;
4176         }
4177         return YAFFS_FAIL;
4178 }
4179
4180 /*----------------------- Initialisation Scanning ---------------------- */
4181
4182 void yaffs_handle_shadowed_obj(struct yaffs_dev *dev, int obj_id,
4183                                int backward_scanning)
4184 {
4185         struct yaffs_obj *obj;
4186
4187         if (backward_scanning) {
4188                 /* Handle YAFFS2 case (backward scanning)
4189                  * If the shadowed object exists then ignore.
4190                  */
4191                 obj = yaffs_find_by_number(dev, obj_id);
4192                 if (obj)
4193                         return;
4194         }
4195
4196         /* Let's create it (if it does not exist) assuming it is a file so that
4197          * it can do shrinking etc.
4198          * We put it in unlinked dir to be cleaned up after the scanning
4199          */
4200         obj =
4201             yaffs_find_or_create_by_number(dev, obj_id, YAFFS_OBJECT_TYPE_FILE);
4202         if (!obj)
4203                 return;
4204         obj->is_shadowed = 1;
4205         yaffs_add_obj_to_dir(dev->unlinked_dir, obj);
4206         obj->variant.file_variant.shrink_size = 0;
4207         obj->valid = 1;         /* So that we don't read any other info. */
4208 }
4209
4210 void yaffs_link_fixup(struct yaffs_dev *dev, struct list_head *hard_list)
4211 {
4212         struct list_head *lh;
4213         struct list_head *save;
4214         struct yaffs_obj *hl;
4215         struct yaffs_obj *in;
4216
4217         list_for_each_safe(lh, save, hard_list) {
4218                 hl = list_entry(lh, struct yaffs_obj, hard_links);
4219                 in = yaffs_find_by_number(dev,
4220                                         hl->variant.hardlink_variant.equiv_id);
4221
4222                 if (in) {
4223                         /* Add the hardlink pointers */
4224                         hl->variant.hardlink_variant.equiv_obj = in;
4225                         list_add(&hl->hard_links, &in->hard_links);
4226                 } else {
4227                         /* Todo Need to report/handle this better.
4228                          * Got a problem... hardlink to a non-existant object
4229                          */
4230                         hl->variant.hardlink_variant.equiv_obj = NULL;
4231                         INIT_LIST_HEAD(&hl->hard_links);
4232                 }
4233         }
4234 }
4235
4236 static void yaffs_strip_deleted_objs(struct yaffs_dev *dev)
4237 {
4238         /*
4239          *  Sort out state of unlinked and deleted objects after scanning.
4240          */
4241         struct list_head *i;
4242         struct list_head *n;
4243         struct yaffs_obj *l;
4244
4245         if (dev->read_only)
4246                 return;
4247
4248         /* Soft delete all the unlinked files */
4249         list_for_each_safe(i, n,
4250                            &dev->unlinked_dir->variant.dir_variant.children) {
4251                 l = list_entry(i, struct yaffs_obj, siblings);
4252                 yaffs_del_obj(l);
4253         }
4254
4255         list_for_each_safe(i, n, &dev->del_dir->variant.dir_variant.children) {
4256                 l = list_entry(i, struct yaffs_obj, siblings);
4257                 yaffs_del_obj(l);
4258         }
4259 }
4260
4261 /*
4262  * This code iterates through all the objects making sure that they are rooted.
4263  * Any unrooted objects are re-rooted in lost+found.
4264  * An object needs to be in one of:
4265  * - Directly under deleted, unlinked
4266  * - Directly or indirectly under root.
4267  *
4268  * Note:
4269  *  This code assumes that we don't ever change the current relationships
4270  *  between directories:
4271  *   root_dir->parent == unlinked_dir->parent == del_dir->parent == NULL
4272  *   lost-n-found->parent == root_dir
4273  *
4274  * This fixes the problem where directories might have inadvertently been
4275  * deleted leaving the object "hanging" without being rooted in the
4276  * directory tree.
4277  */
4278
4279 static int yaffs_has_null_parent(struct yaffs_dev *dev, struct yaffs_obj *obj)
4280 {
4281         return (obj == dev->del_dir ||
4282                 obj == dev->unlinked_dir || obj == dev->root_dir);
4283 }
4284
4285 static void yaffs_fix_hanging_objs(struct yaffs_dev *dev)
4286 {
4287         struct yaffs_obj *obj;
4288         struct yaffs_obj *parent;
4289         int i;
4290         struct list_head *lh;
4291         struct list_head *n;
4292         int depth_limit;
4293         int hanging;
4294
4295         if (dev->read_only)
4296                 return;
4297
4298         /* Iterate through the objects in each hash entry,
4299          * looking at each object.
4300          * Make sure it is rooted.
4301          */
4302
4303         for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
4304                 list_for_each_safe(lh, n, &dev->obj_bucket[i].list) {
4305                         obj = list_entry(lh, struct yaffs_obj, hash_link);
4306                         parent = obj->parent;
4307
4308                         if (yaffs_has_null_parent(dev, obj)) {
4309                                 /* These directories are not hanging */
4310                                 hanging = 0;
4311                         } else if (!parent ||
4312                                    parent->variant_type !=
4313                                    YAFFS_OBJECT_TYPE_DIRECTORY) {
4314                                 hanging = 1;
4315                         } else if (yaffs_has_null_parent(dev, parent)) {
4316                                 hanging = 0;
4317                         } else {
4318                                 /*
4319                                  * Need to follow the parent chain to
4320                                  * see if it is hanging.
4321                                  */
4322                                 hanging = 0;
4323                                 depth_limit = 100;
4324
4325                                 while (parent != dev->root_dir &&
4326                                        parent->parent &&
4327                                        parent->parent->variant_type ==
4328                                        YAFFS_OBJECT_TYPE_DIRECTORY &&
4329                                        depth_limit > 0) {
4330                                         parent = parent->parent;
4331                                         depth_limit--;
4332                                 }
4333                                 if (parent != dev->root_dir)
4334                                         hanging = 1;
4335                         }
4336                         if (hanging) {
4337                                 yaffs_trace(YAFFS_TRACE_SCAN,
4338                                         "Hanging object %d moved to lost and found",
4339                                         obj->obj_id);
4340                                 yaffs_add_obj_to_dir(dev->lost_n_found, obj);
4341                         }
4342                 }
4343         }
4344 }
4345
4346 /*
4347  * Delete directory contents for cleaning up lost and found.
4348  */
4349 static void yaffs_del_dir_contents(struct yaffs_obj *dir)
4350 {
4351         struct yaffs_obj *obj;
4352         struct list_head *lh;
4353         struct list_head *n;
4354
4355         if (dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
4356                 BUG();
4357
4358         list_for_each_safe(lh, n, &dir->variant.dir_variant.children) {
4359                 obj = list_entry(lh, struct yaffs_obj, siblings);
4360                 if (obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY)
4361                         yaffs_del_dir_contents(obj);
4362                 yaffs_trace(YAFFS_TRACE_SCAN,
4363                         "Deleting lost_found object %d",
4364                         obj->obj_id);
4365                 yaffs_unlink_obj(obj);
4366         }
4367 }
4368
4369 static void yaffs_empty_l_n_f(struct yaffs_dev *dev)
4370 {
4371         yaffs_del_dir_contents(dev->lost_n_found);
4372 }
4373
4374
4375 struct yaffs_obj *yaffs_find_by_name(struct yaffs_obj *directory,
4376                                      const YCHAR *name)
4377 {
4378         int sum;
4379         struct list_head *i;
4380         YCHAR buffer[YAFFS_MAX_NAME_LENGTH + 1];
4381         struct yaffs_obj *l;
4382
4383         if (!name)
4384                 return NULL;
4385
4386         if (!directory) {
4387                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4388                         "tragedy: yaffs_find_by_name: null pointer directory"
4389                         );
4390                 BUG();
4391                 return NULL;
4392         }
4393         if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4394                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4395                         "tragedy: yaffs_find_by_name: non-directory"
4396                         );
4397                 BUG();
4398         }
4399
4400         sum = yaffs_calc_name_sum(name);
4401
4402         list_for_each(i, &directory->variant.dir_variant.children) {
4403                 l = list_entry(i, struct yaffs_obj, siblings);
4404
4405                 if (l->parent != directory)
4406                         BUG();
4407
4408                 yaffs_check_obj_details_loaded(l);
4409
4410                 /* Special case for lost-n-found */
4411                 if (l->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
4412                         if (!strcmp(name, YAFFS_LOSTNFOUND_NAME))
4413                                 return l;
4414                 } else if (l->sum == sum || l->hdr_chunk <= 0) {
4415                         /* LostnFound chunk called Objxxx
4416                          * Do a real check
4417                          */
4418                         yaffs_get_obj_name(l, buffer,
4419                                 YAFFS_MAX_NAME_LENGTH + 1);
4420                         if (!strncmp(name, buffer, YAFFS_MAX_NAME_LENGTH))
4421                                 return l;
4422                 }
4423         }
4424         return NULL;
4425 }
4426
4427 /* GetEquivalentObject dereferences any hard links to get to the
4428  * actual object.
4429  */
4430
4431 struct yaffs_obj *yaffs_get_equivalent_obj(struct yaffs_obj *obj)
4432 {
4433         if (obj && obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
4434                 obj = obj->variant.hardlink_variant.equiv_obj;
4435                 yaffs_check_obj_details_loaded(obj);
4436         }
4437         return obj;
4438 }
4439
4440 /*
4441  *  A note or two on object names.
4442  *  * If the object name is missing, we then make one up in the form objnnn
4443  *
4444  *  * ASCII names are stored in the object header's name field from byte zero
4445  *  * Unicode names are historically stored starting from byte zero.
4446  *
4447  * Then there are automatic Unicode names...
4448  * The purpose of these is to save names in a way that can be read as
4449  * ASCII or Unicode names as appropriate, thus allowing a Unicode and ASCII
4450  * system to share files.
4451  *
4452  * These automatic unicode are stored slightly differently...
4453  *  - If the name can fit in the ASCII character space then they are saved as
4454  *    ascii names as per above.
4455  *  - If the name needs Unicode then the name is saved in Unicode
4456  *    starting at oh->name[1].
4457
4458  */
4459 static void yaffs_fix_null_name(struct yaffs_obj *obj, YCHAR *name,
4460                                 int buffer_size)
4461 {
4462         /* Create an object name if we could not find one. */
4463         if (strnlen(name, YAFFS_MAX_NAME_LENGTH) == 0) {
4464                 YCHAR local_name[20];
4465                 YCHAR num_string[20];
4466                 YCHAR *x = &num_string[19];
4467                 unsigned v = obj->obj_id;
4468                 num_string[19] = 0;
4469                 while (v > 0) {
4470                         x--;
4471                         *x = '0' + (v % 10);
4472                         v /= 10;
4473                 }
4474                 /* make up a name */
4475                 strcpy(local_name, YAFFS_LOSTNFOUND_PREFIX);
4476                 strcat(local_name, x);
4477                 strncpy(name, local_name, buffer_size - 1);
4478         }
4479 }
4480
4481 int yaffs_get_obj_name(struct yaffs_obj *obj, YCHAR *name, int buffer_size)
4482 {
4483         memset(name, 0, buffer_size * sizeof(YCHAR));
4484         yaffs_check_obj_details_loaded(obj);
4485         if (obj->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
4486                 strncpy(name, YAFFS_LOSTNFOUND_NAME, buffer_size - 1);
4487         } else if (obj->short_name[0]) {
4488                 strcpy(name, obj->short_name);
4489         } else if (obj->hdr_chunk > 0) {
4490                 int result;
4491                 u8 *buffer = yaffs_get_temp_buffer(obj->my_dev);
4492
4493                 struct yaffs_obj_hdr *oh = (struct yaffs_obj_hdr *)buffer;
4494
4495                 memset(buffer, 0, obj->my_dev->data_bytes_per_chunk);
4496
4497                 if (obj->hdr_chunk > 0) {
4498                         result = yaffs_rd_chunk_tags_nand(obj->my_dev,
4499                                                           obj->hdr_chunk,
4500                                                           buffer, NULL);
4501                 }
4502                 yaffs_load_name_from_oh(obj->my_dev, name, oh->name,
4503                                         buffer_size);
4504
4505                 yaffs_release_temp_buffer(obj->my_dev, buffer);
4506         }
4507
4508         yaffs_fix_null_name(obj, name, buffer_size);
4509
4510         return strnlen(name, YAFFS_MAX_NAME_LENGTH);
4511 }
4512
4513 loff_t yaffs_get_obj_length(struct yaffs_obj *obj)
4514 {
4515         /* Dereference any hard linking */
4516         obj = yaffs_get_equivalent_obj(obj);
4517
4518         if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
4519                 return obj->variant.file_variant.file_size;
4520         if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
4521                 if (!obj->variant.symlink_variant.alias)
4522                         return 0;
4523                 return strnlen(obj->variant.symlink_variant.alias,
4524                                      YAFFS_MAX_ALIAS_LENGTH);
4525         } else {
4526                 /* Only a directory should drop through to here */
4527                 return obj->my_dev->data_bytes_per_chunk;
4528         }
4529 }
4530
4531 int yaffs_get_obj_link_count(struct yaffs_obj *obj)
4532 {
4533         int count = 0;
4534         struct list_head *i;
4535
4536         if (!obj->unlinked)
4537                 count++;        /* the object itself */
4538
4539         list_for_each(i, &obj->hard_links)
4540             count++;            /* add the hard links; */
4541
4542         return count;
4543 }
4544
4545 int yaffs_get_obj_inode(struct yaffs_obj *obj)
4546 {
4547         obj = yaffs_get_equivalent_obj(obj);
4548
4549         return obj->obj_id;
4550 }
4551
4552 unsigned yaffs_get_obj_type(struct yaffs_obj *obj)
4553 {
4554         obj = yaffs_get_equivalent_obj(obj);
4555
4556         switch (obj->variant_type) {
4557         case YAFFS_OBJECT_TYPE_FILE:
4558                 return DT_REG;
4559                 break;
4560         case YAFFS_OBJECT_TYPE_DIRECTORY:
4561                 return DT_DIR;
4562                 break;
4563         case YAFFS_OBJECT_TYPE_SYMLINK:
4564                 return DT_LNK;
4565                 break;
4566         case YAFFS_OBJECT_TYPE_HARDLINK:
4567                 return DT_REG;
4568                 break;
4569         case YAFFS_OBJECT_TYPE_SPECIAL:
4570                 if (S_ISFIFO(obj->yst_mode))
4571                         return DT_FIFO;
4572                 if (S_ISCHR(obj->yst_mode))
4573                         return DT_CHR;
4574                 if (S_ISBLK(obj->yst_mode))
4575                         return DT_BLK;
4576                 if (S_ISSOCK(obj->yst_mode))
4577                         return DT_SOCK;
4578                 return DT_REG;
4579                 break;
4580         default:
4581                 return DT_REG;
4582                 break;
4583         }
4584 }
4585
4586 YCHAR *yaffs_get_symlink_alias(struct yaffs_obj *obj)
4587 {
4588         obj = yaffs_get_equivalent_obj(obj);
4589         if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK)
4590                 return yaffs_clone_str(obj->variant.symlink_variant.alias);
4591         else
4592                 return yaffs_clone_str(_Y(""));
4593 }
4594
4595 /*--------------------------- Initialisation code -------------------------- */
4596
4597 static int yaffs_check_dev_fns(struct yaffs_dev *dev)
4598 {
4599         struct yaffs_driver *drv = &dev->drv;
4600         struct yaffs_tags_handler *tagger = &dev->tagger;
4601
4602         /* Common functions, gotta have */
4603         if (!drv->drv_read_chunk_fn ||
4604             !drv->drv_write_chunk_fn ||
4605             !drv->drv_erase_fn)
4606                 return 0;
4607
4608         if (dev->param.is_yaffs2 &&
4609              (!drv->drv_mark_bad_fn  || !drv->drv_check_bad_fn))
4610                 return 0;
4611
4612         /* Install the default tags marshalling functions if needed. */
4613         yaffs_tags_compat_install(dev);
4614         yaffs_tags_marshall_install(dev);
4615
4616         /* Check we now have the marshalling functions required. */
4617         if (!tagger->write_chunk_tags_fn ||
4618             !tagger->read_chunk_tags_fn ||
4619             !tagger->query_block_fn ||
4620             !tagger->mark_bad_fn)
4621                 return 0;
4622
4623         return 1;
4624 }
4625
4626 static int yaffs_create_initial_dir(struct yaffs_dev *dev)
4627 {
4628         /* Initialise the unlinked, deleted, root and lost+found directories */
4629         dev->lost_n_found = dev->root_dir = NULL;
4630         dev->unlinked_dir = dev->del_dir = NULL;
4631         dev->unlinked_dir =
4632             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_UNLINKED, S_IFDIR);
4633         dev->del_dir =
4634             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_DELETED, S_IFDIR);
4635         dev->root_dir =
4636             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_ROOT,
4637                                   YAFFS_ROOT_MODE | S_IFDIR);
4638         dev->lost_n_found =
4639             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_LOSTNFOUND,
4640                                   YAFFS_LOSTNFOUND_MODE | S_IFDIR);
4641
4642         if (dev->lost_n_found && dev->root_dir && dev->unlinked_dir
4643             && dev->del_dir) {
4644                 yaffs_add_obj_to_dir(dev->root_dir, dev->lost_n_found);
4645                 return YAFFS_OK;
4646         }
4647         return YAFFS_FAIL;
4648 }
4649
4650 /* Low level init.
4651  * Typically only used by yaffs_guts_initialise, but also used by the
4652  * Low level yaffs driver tests.
4653  */
4654
4655 int yaffs_guts_ll_init(struct yaffs_dev *dev)
4656 {
4657
4658
4659         yaffs_trace(YAFFS_TRACE_TRACING, "yaffs: yaffs_ll_init()");
4660
4661         if (!dev) {
4662                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4663                         "yaffs: Need a device"
4664                         );
4665                 return YAFFS_FAIL;
4666         }
4667
4668         if (dev->ll_init)
4669                 return YAFFS_OK;
4670
4671         dev->internal_start_block = dev->param.start_block;
4672         dev->internal_end_block = dev->param.end_block;
4673         dev->block_offset = 0;
4674         dev->chunk_offset = 0;
4675         dev->n_free_chunks = 0;
4676
4677         dev->gc_block = 0;
4678
4679         if (dev->param.start_block == 0) {
4680                 dev->internal_start_block = dev->param.start_block + 1;
4681                 dev->internal_end_block = dev->param.end_block + 1;
4682                 dev->block_offset = 1;
4683                 dev->chunk_offset = dev->param.chunks_per_block;
4684         }
4685
4686         /* Check geometry parameters. */
4687
4688         if ((!dev->param.inband_tags && dev->param.is_yaffs2 &&
4689                 dev->param.total_bytes_per_chunk < 1024) ||
4690                 (!dev->param.is_yaffs2 &&
4691                         dev->param.total_bytes_per_chunk < 512) ||
4692                 (dev->param.inband_tags && !dev->param.is_yaffs2) ||
4693                  dev->param.chunks_per_block < 2 ||
4694                  dev->param.n_reserved_blocks < 2 ||
4695                 dev->internal_start_block <= 0 ||
4696                 dev->internal_end_block <= 0 ||
4697                 dev->internal_end_block <=
4698                 (dev->internal_start_block + dev->param.n_reserved_blocks + 2)
4699                 ) {
4700                 /* otherwise it is too small */
4701                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4702                         "NAND geometry problems: chunk size %d, type is yaffs%s, inband_tags %d ",
4703                         dev->param.total_bytes_per_chunk,
4704                         dev->param.is_yaffs2 ? "2" : "",
4705                         dev->param.inband_tags);
4706                 return YAFFS_FAIL;
4707         }
4708
4709         /* Sort out space for inband tags, if required */
4710         if (dev->param.inband_tags)
4711                 dev->data_bytes_per_chunk =
4712                     dev->param.total_bytes_per_chunk -
4713                     sizeof(struct yaffs_packed_tags2_tags_only);
4714         else
4715                 dev->data_bytes_per_chunk = dev->param.total_bytes_per_chunk;
4716
4717         /* Got the right mix of functions? */
4718         if (!yaffs_check_dev_fns(dev)) {
4719                 /* Function missing */
4720                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4721                         "device function(s) missing or wrong");
4722
4723                 return YAFFS_FAIL;
4724         }
4725
4726         if (yaffs_init_nand(dev) != YAFFS_OK) {
4727                 yaffs_trace(YAFFS_TRACE_ALWAYS, "InitialiseNAND failed");
4728                 return YAFFS_FAIL;
4729         }
4730
4731         return YAFFS_OK;
4732 }
4733
4734
4735 int yaffs_guts_format_dev(struct yaffs_dev *dev)
4736 {
4737         int i;
4738         enum yaffs_block_state state;
4739         u32 dummy;
4740
4741         if(yaffs_guts_ll_init(dev) != YAFFS_OK)
4742                 return YAFFS_FAIL;
4743
4744         if(dev->is_mounted)
4745                 return YAFFS_FAIL;
4746
4747         for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
4748                 yaffs_query_init_block_state(dev, i, &state, &dummy);
4749                 if (state != YAFFS_BLOCK_STATE_DEAD)
4750                         yaffs_erase_block(dev, i);
4751         }
4752
4753         return YAFFS_OK;
4754 }
4755
4756
4757 int yaffs_guts_initialise(struct yaffs_dev *dev)
4758 {
4759         int init_failed = 0;
4760         unsigned x;
4761         int bits;
4762
4763         if(yaffs_guts_ll_init(dev) != YAFFS_OK)
4764                 return YAFFS_FAIL;
4765
4766         if (dev->is_mounted) {
4767                 yaffs_trace(YAFFS_TRACE_ALWAYS, "device already mounted");
4768                 return YAFFS_FAIL;
4769         }
4770
4771         dev->is_mounted = 1;
4772
4773         /* OK now calculate a few things for the device */
4774
4775         /*
4776          *  Calculate all the chunk size manipulation numbers:
4777          */
4778         x = dev->data_bytes_per_chunk;
4779         /* We always use dev->chunk_shift and dev->chunk_div */
4780         dev->chunk_shift = calc_shifts(x);
4781         x >>= dev->chunk_shift;
4782         dev->chunk_div = x;
4783         /* We only use chunk mask if chunk_div is 1 */
4784         dev->chunk_mask = (1 << dev->chunk_shift) - 1;
4785
4786         /*
4787          * Calculate chunk_grp_bits.
4788          * We need to find the next power of 2 > than internal_end_block
4789          */
4790
4791         x = dev->param.chunks_per_block * (dev->internal_end_block + 1);
4792
4793         bits = calc_shifts_ceiling(x);
4794
4795         /* Set up tnode width if wide tnodes are enabled. */
4796         if (!dev->param.wide_tnodes_disabled) {
4797                 /* bits must be even so that we end up with 32-bit words */
4798                 if (bits & 1)
4799                         bits++;
4800                 if (bits < 16)
4801                         dev->tnode_width = 16;
4802                 else
4803                         dev->tnode_width = bits;
4804         } else {
4805                 dev->tnode_width = 16;
4806         }
4807
4808         dev->tnode_mask = (1 << dev->tnode_width) - 1;
4809
4810         /* Level0 Tnodes are 16 bits or wider (if wide tnodes are enabled),
4811          * so if the bitwidth of the
4812          * chunk range we're using is greater than 16 we need
4813          * to figure out chunk shift and chunk_grp_size
4814          */
4815
4816         if (bits <= dev->tnode_width)
4817                 dev->chunk_grp_bits = 0;
4818         else
4819                 dev->chunk_grp_bits = bits - dev->tnode_width;
4820
4821         dev->tnode_size = (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8;
4822         if (dev->tnode_size < sizeof(struct yaffs_tnode))
4823                 dev->tnode_size = sizeof(struct yaffs_tnode);
4824
4825         dev->chunk_grp_size = 1 << dev->chunk_grp_bits;
4826
4827         if (dev->param.chunks_per_block < dev->chunk_grp_size) {
4828                 /* We have a problem because the soft delete won't work if
4829                  * the chunk group size > chunks per block.
4830                  * This can be remedied by using larger "virtual blocks".
4831                  */
4832                 yaffs_trace(YAFFS_TRACE_ALWAYS, "chunk group too large");
4833
4834                 return YAFFS_FAIL;
4835         }
4836
4837         /* Finished verifying the device, continue with initialisation */
4838
4839         /* More device initialisation */
4840         dev->all_gcs = 0;
4841         dev->passive_gc_count = 0;
4842         dev->oldest_dirty_gc_count = 0;
4843         dev->bg_gcs = 0;
4844         dev->gc_block_finder = 0;
4845         dev->buffered_block = -1;
4846         dev->doing_buffered_block_rewrite = 0;
4847         dev->n_deleted_files = 0;
4848         dev->n_bg_deletions = 0;
4849         dev->n_unlinked_files = 0;
4850         dev->n_ecc_fixed = 0;
4851         dev->n_ecc_unfixed = 0;
4852         dev->n_tags_ecc_fixed = 0;
4853         dev->n_tags_ecc_unfixed = 0;
4854         dev->n_erase_failures = 0;
4855         dev->n_erased_blocks = 0;
4856         dev->gc_disable = 0;
4857         dev->has_pending_prioritised_gc = 1;
4858                 /* Assume the worst for now, will get fixed on first GC */
4859         INIT_LIST_HEAD(&dev->dirty_dirs);
4860         dev->oldest_dirty_seq = 0;
4861         dev->oldest_dirty_block = 0;
4862
4863         /* Initialise temporary buffers and caches. */
4864         if (!yaffs_init_tmp_buffers(dev))
4865                 init_failed = 1;
4866
4867         dev->cache = NULL;
4868         dev->gc_cleanup_list = NULL;
4869
4870         if (!init_failed && dev->param.n_caches > 0) {
4871                 int i;
4872                 void *buf;
4873                 int cache_bytes =
4874                     dev->param.n_caches * sizeof(struct yaffs_cache);
4875
4876                 if (dev->param.n_caches > YAFFS_MAX_SHORT_OP_CACHES)
4877                         dev->param.n_caches = YAFFS_MAX_SHORT_OP_CACHES;
4878
4879                 dev->cache = kmalloc(cache_bytes, GFP_NOFS);
4880
4881                 buf = (u8 *) dev->cache;
4882
4883                 if (dev->cache)
4884                         memset(dev->cache, 0, cache_bytes);
4885
4886                 for (i = 0; i < dev->param.n_caches && buf; i++) {
4887                         dev->cache[i].object = NULL;
4888                         dev->cache[i].last_use = 0;
4889                         dev->cache[i].dirty = 0;
4890                         dev->cache[i].data = buf =
4891                             kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
4892                 }
4893                 if (!buf)
4894                         init_failed = 1;
4895
4896                 dev->cache_last_use = 0;
4897         }
4898
4899         dev->cache_hits = 0;
4900
4901         if (!init_failed) {
4902                 dev->gc_cleanup_list =
4903                     kmalloc(dev->param.chunks_per_block * sizeof(u32),
4904                                         GFP_NOFS);
4905                 if (!dev->gc_cleanup_list)
4906                         init_failed = 1;
4907         }
4908
4909         if (dev->param.is_yaffs2)
4910                 dev->param.use_header_file_size = 1;
4911
4912         if (!init_failed && !yaffs_init_blocks(dev))
4913                 init_failed = 1;
4914
4915         yaffs_init_tnodes_and_objs(dev);
4916
4917         if (!init_failed && !yaffs_create_initial_dir(dev))
4918                 init_failed = 1;
4919
4920         if (!init_failed && dev->param.is_yaffs2 &&
4921                 !dev->param.disable_summary &&
4922                 !yaffs_summary_init(dev))
4923                 init_failed = 1;
4924
4925         if (!init_failed) {
4926                 /* Now scan the flash. */
4927                 if (dev->param.is_yaffs2) {
4928                         if (yaffs2_checkpt_restore(dev)) {
4929                                 yaffs_check_obj_details_loaded(dev->root_dir);
4930                                 yaffs_trace(YAFFS_TRACE_CHECKPOINT |
4931                                         YAFFS_TRACE_MOUNT,
4932                                         "yaffs: restored from checkpoint"
4933                                         );
4934                         } else {
4935
4936                                 /* Clean up the mess caused by an aborted
4937                                  * checkpoint load then scan backwards.
4938                                  */
4939                                 yaffs_deinit_blocks(dev);
4940
4941                                 yaffs_deinit_tnodes_and_objs(dev);
4942
4943                                 dev->n_erased_blocks = 0;
4944                                 dev->n_free_chunks = 0;
4945                                 dev->alloc_block = -1;
4946                                 dev->alloc_page = -1;
4947                                 dev->n_deleted_files = 0;
4948                                 dev->n_unlinked_files = 0;
4949                                 dev->n_bg_deletions = 0;
4950
4951                                 if (!init_failed && !yaffs_init_blocks(dev))
4952                                         init_failed = 1;
4953
4954                                 yaffs_init_tnodes_and_objs(dev);
4955
4956                                 if (!init_failed
4957                                     && !yaffs_create_initial_dir(dev))
4958                                         init_failed = 1;
4959
4960                                 if (!init_failed && !yaffs2_scan_backwards(dev))
4961                                         init_failed = 1;
4962                         }
4963                 } else if (!yaffs1_scan(dev)) {
4964                         init_failed = 1;
4965                 }
4966
4967                 yaffs_strip_deleted_objs(dev);
4968                 yaffs_fix_hanging_objs(dev);
4969                 if (dev->param.empty_lost_n_found)
4970                         yaffs_empty_l_n_f(dev);
4971         }
4972
4973         if (init_failed) {
4974                 /* Clean up the mess */
4975                 yaffs_trace(YAFFS_TRACE_TRACING,
4976                   "yaffs: yaffs_guts_initialise() aborted.");
4977
4978                 yaffs_deinitialise(dev);
4979                 return YAFFS_FAIL;
4980         }
4981
4982         /* Zero out stats */
4983         dev->n_page_reads = 0;
4984         dev->n_page_writes = 0;
4985         dev->n_erasures = 0;
4986         dev->n_gc_copies = 0;
4987         dev->n_retried_writes = 0;
4988
4989         dev->n_retired_blocks = 0;
4990
4991         yaffs_verify_free_chunks(dev);
4992         yaffs_verify_blocks(dev);
4993
4994         /* Clean up any aborted checkpoint data */
4995         if (!dev->is_checkpointed && dev->blocks_in_checkpt > 0)
4996                 yaffs2_checkpt_invalidate(dev);
4997
4998         yaffs_trace(YAFFS_TRACE_TRACING,
4999           "yaffs: yaffs_guts_initialise() done.");
5000         return YAFFS_OK;
5001 }
5002
5003 void yaffs_deinitialise(struct yaffs_dev *dev)
5004 {
5005         if (dev->is_mounted) {
5006                 int i;
5007
5008                 yaffs_deinit_blocks(dev);
5009                 yaffs_deinit_tnodes_and_objs(dev);
5010                 yaffs_summary_deinit(dev);
5011
5012                 if (dev->param.n_caches > 0 && dev->cache) {
5013
5014                         for (i = 0; i < dev->param.n_caches; i++) {
5015                                 kfree(dev->cache[i].data);
5016                                 dev->cache[i].data = NULL;
5017                         }
5018
5019                         kfree(dev->cache);
5020                         dev->cache = NULL;
5021                 }
5022
5023                 kfree(dev->gc_cleanup_list);
5024
5025                 for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++)
5026                         kfree(dev->temp_buffer[i].buffer);
5027
5028                 dev->is_mounted = 0;
5029
5030                 yaffs_deinit_nand(dev);
5031         }
5032 }
5033
5034 int yaffs_count_free_chunks(struct yaffs_dev *dev)
5035 {
5036         int n_free = 0;
5037         int b;
5038         struct yaffs_block_info *blk;
5039
5040         blk = dev->block_info;
5041         for (b = dev->internal_start_block; b <= dev->internal_end_block; b++) {
5042                 switch (blk->block_state) {
5043                 case YAFFS_BLOCK_STATE_EMPTY:
5044                 case YAFFS_BLOCK_STATE_ALLOCATING:
5045                 case YAFFS_BLOCK_STATE_COLLECTING:
5046                 case YAFFS_BLOCK_STATE_FULL:
5047                         n_free +=
5048                             (dev->param.chunks_per_block - blk->pages_in_use +
5049                              blk->soft_del_pages);
5050                         break;
5051                 default:
5052                         break;
5053                 }
5054                 blk++;
5055         }
5056         return n_free;
5057 }
5058
5059 int yaffs_get_n_free_chunks(struct yaffs_dev *dev)
5060 {
5061         /* This is what we report to the outside world */
5062         int n_free;
5063         int n_dirty_caches;
5064         int blocks_for_checkpt;
5065         int i;
5066
5067         n_free = dev->n_free_chunks;
5068         n_free += dev->n_deleted_files;
5069
5070         /* Now count and subtract the number of dirty chunks in the cache. */
5071
5072         for (n_dirty_caches = 0, i = 0; i < dev->param.n_caches; i++) {
5073                 if (dev->cache[i].dirty)
5074                         n_dirty_caches++;
5075         }
5076
5077         n_free -= n_dirty_caches;
5078
5079         n_free -=
5080             ((dev->param.n_reserved_blocks + 1) * dev->param.chunks_per_block);
5081
5082         /* Now figure checkpoint space and report that... */
5083         blocks_for_checkpt = yaffs_calc_checkpt_blocks_required(dev);
5084
5085         n_free -= (blocks_for_checkpt * dev->param.chunks_per_block);
5086
5087         if (n_free < 0)
5088                 n_free = 0;
5089
5090         return n_free;
5091 }
5092
5093
5094
5095 /*
5096  * Marshalling functions to get loff_t file sizes into and out of
5097  * object headers.
5098  */
5099 void yaffs_oh_size_load(struct yaffs_obj_hdr *oh, loff_t fsize)
5100 {
5101         oh->file_size_low = (fsize & 0xFFFFFFFF);
5102         oh->file_size_high = ((fsize >> 32) & 0xFFFFFFFF);
5103 }
5104
5105 loff_t yaffs_oh_to_size(struct yaffs_obj_hdr *oh)
5106 {
5107         loff_t retval;
5108
5109         if (sizeof(loff_t) >= 8 && ~(oh->file_size_high))
5110                 retval = (((loff_t) oh->file_size_high) << 32) |
5111                         (((loff_t) oh->file_size_low) & 0xFFFFFFFF);
5112         else
5113                 retval = (loff_t) oh->file_size_low;
5114
5115         return retval;
5116 }
5117
5118
5119 void yaffs_count_blocks_by_state(struct yaffs_dev *dev, int bs[10])
5120 {
5121         int i;
5122         struct yaffs_block_info *bi;
5123         int s;
5124
5125         for(i = 0; i < 10; i++)
5126                 bs[i] = 0;
5127
5128         for(i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
5129                 bi = yaffs_get_block_info(dev, i);
5130                 s = bi->block_state;
5131                 if(s > YAFFS_BLOCK_STATE_DEAD || s < YAFFS_BLOCK_STATE_UNKNOWN)
5132                         bs[0]++;
5133                 else
5134                         bs[s]++;
5135         }
5136 }