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_file_cache(struct yaffs_obj *obj)
1381 {
1382         struct yaffs_dev *dev = obj->my_dev;
1383         int lowest = -99;       /* Stop compiler whining. */
1384         int i;
1385         struct yaffs_cache *cache;
1386         int chunk_written = 0;
1387         int n_caches = obj->my_dev->param.n_caches;
1388
1389         if (n_caches < 1)
1390                 return;
1391         do {
1392                 cache = NULL;
1393
1394                 /* Find the lowest dirty chunk for this object */
1395                 for (i = 0; i < n_caches; i++) {
1396                         if (dev->cache[i].object == obj &&
1397                             dev->cache[i].dirty) {
1398                                 if (!cache ||
1399                                     dev->cache[i].chunk_id < lowest) {
1400                                         cache = &dev->cache[i];
1401                                         lowest = cache->chunk_id;
1402                                 }
1403                         }
1404                 }
1405
1406                 if (cache && !cache->locked) {
1407                         /* Write it out and free it up */
1408                         chunk_written =
1409                             yaffs_wr_data_obj(cache->object,
1410                                               cache->chunk_id,
1411                                               cache->data,
1412                                               cache->n_bytes, 1);
1413                         cache->dirty = 0;
1414                         cache->object = NULL;
1415                 }
1416         } while (cache && chunk_written > 0);
1417
1418         if (cache)
1419                 /* Hoosterman, disk full while writing cache out. */
1420                 yaffs_trace(YAFFS_TRACE_ERROR,
1421                         "yaffs tragedy: no space during cache write");
1422 }
1423
1424 /*yaffs_flush_whole_cache(dev)
1425  *
1426  *
1427  */
1428
1429 void yaffs_flush_whole_cache(struct yaffs_dev *dev)
1430 {
1431         struct yaffs_obj *obj;
1432         int n_caches = dev->param.n_caches;
1433         int i;
1434
1435         /* Find a dirty object in the cache and flush it...
1436          * until there are no further dirty objects.
1437          */
1438         do {
1439                 obj = NULL;
1440                 for (i = 0; i < n_caches && !obj; i++) {
1441                         if (dev->cache[i].object && dev->cache[i].dirty)
1442                                 obj = dev->cache[i].object;
1443                 }
1444                 if (obj)
1445                         yaffs_flush_file_cache(obj);
1446         } while (obj);
1447
1448 }
1449
1450 /* Grab us a cache chunk for use.
1451  * First look for an empty one.
1452  * Then look for the least recently used non-dirty one.
1453  * Then look for the least recently used dirty one...., flush and look again.
1454  */
1455 static struct yaffs_cache *yaffs_grab_chunk_worker(struct yaffs_dev *dev)
1456 {
1457         int i;
1458
1459         if (dev->param.n_caches > 0) {
1460                 for (i = 0; i < dev->param.n_caches; i++) {
1461                         if (!dev->cache[i].object)
1462                                 return &dev->cache[i];
1463                 }
1464         }
1465         return NULL;
1466 }
1467
1468 static struct yaffs_cache *yaffs_grab_chunk_cache(struct yaffs_dev *dev)
1469 {
1470         struct yaffs_cache *cache;
1471         struct yaffs_obj *the_obj;
1472         int usage;
1473         int i;
1474         int pushout;
1475
1476         if (dev->param.n_caches < 1)
1477                 return NULL;
1478
1479         /* Try find a non-dirty one... */
1480
1481         cache = yaffs_grab_chunk_worker(dev);
1482
1483         if (!cache) {
1484                 /* They were all dirty, find the LRU object and flush
1485                  * its cache, then  find again.
1486                  * NB what's here is not very accurate,
1487                  * we actually flush the object with the LRU chunk.
1488                  */
1489
1490                 /* With locking we can't assume we can use entry zero,
1491                  * Set the_obj to a valid pointer for Coverity. */
1492                 the_obj = dev->cache[0].object;
1493                 usage = -1;
1494                 cache = NULL;
1495                 pushout = -1;
1496
1497                 for (i = 0; i < dev->param.n_caches; i++) {
1498                         if (dev->cache[i].object &&
1499                             !dev->cache[i].locked &&
1500                             (dev->cache[i].last_use < usage ||
1501                             !cache)) {
1502                                 usage = dev->cache[i].last_use;
1503                                 the_obj = dev->cache[i].object;
1504                                 cache = &dev->cache[i];
1505                                 pushout = i;
1506                         }
1507                 }
1508
1509                 if (!cache || cache->dirty) {
1510                         /* Flush and try again */
1511                         yaffs_flush_file_cache(the_obj);
1512                         cache = yaffs_grab_chunk_worker(dev);
1513                 }
1514         }
1515         return cache;
1516 }
1517
1518 /* Find a cached chunk */
1519 static struct yaffs_cache *yaffs_find_chunk_cache(const struct yaffs_obj *obj,
1520                                                   int chunk_id)
1521 {
1522         struct yaffs_dev *dev = obj->my_dev;
1523         int i;
1524
1525         if (dev->param.n_caches < 1)
1526                 return NULL;
1527
1528         for (i = 0; i < dev->param.n_caches; i++) {
1529                 if (dev->cache[i].object == obj &&
1530                     dev->cache[i].chunk_id == chunk_id) {
1531                         dev->cache_hits++;
1532
1533                         return &dev->cache[i];
1534                 }
1535         }
1536         return NULL;
1537 }
1538
1539 /* Mark the chunk for the least recently used algorithym */
1540 static void yaffs_use_cache(struct yaffs_dev *dev, struct yaffs_cache *cache,
1541                             int is_write)
1542 {
1543         int i;
1544
1545         if (dev->param.n_caches < 1)
1546                 return;
1547
1548         if (dev->cache_last_use < 0 ||
1549                 dev->cache_last_use > 100000000) {
1550                 /* Reset the cache usages */
1551                 for (i = 1; i < dev->param.n_caches; i++)
1552                         dev->cache[i].last_use = 0;
1553
1554                 dev->cache_last_use = 0;
1555         }
1556         dev->cache_last_use++;
1557         cache->last_use = dev->cache_last_use;
1558
1559         if (is_write)
1560                 cache->dirty = 1;
1561 }
1562
1563 /* Invalidate a single cache page.
1564  * Do this when a whole page gets written,
1565  * ie the short cache for this page is no longer valid.
1566  */
1567 static void yaffs_invalidate_chunk_cache(struct yaffs_obj *object, int chunk_id)
1568 {
1569         struct yaffs_cache *cache;
1570
1571         if (object->my_dev->param.n_caches > 0) {
1572                 cache = yaffs_find_chunk_cache(object, chunk_id);
1573
1574                 if (cache)
1575                         cache->object = NULL;
1576         }
1577 }
1578
1579 /* Invalidate all the cache pages associated with this object
1580  * Do this whenever ther file is deleted or resized.
1581  */
1582 static void yaffs_invalidate_whole_cache(struct yaffs_obj *in)
1583 {
1584         int i;
1585         struct yaffs_dev *dev = in->my_dev;
1586
1587         if (dev->param.n_caches > 0) {
1588                 /* Invalidate it. */
1589                 for (i = 0; i < dev->param.n_caches; i++) {
1590                         if (dev->cache[i].object == in)
1591                                 dev->cache[i].object = NULL;
1592                 }
1593         }
1594 }
1595
1596 static void yaffs_unhash_obj(struct yaffs_obj *obj)
1597 {
1598         int bucket;
1599         struct yaffs_dev *dev = obj->my_dev;
1600
1601         /* If it is still linked into the bucket list, free from the list */
1602         if (!list_empty(&obj->hash_link)) {
1603                 list_del_init(&obj->hash_link);
1604                 bucket = yaffs_hash_fn(obj->obj_id);
1605                 dev->obj_bucket[bucket].count--;
1606         }
1607 }
1608
1609 /*  FreeObject frees up a Object and puts it back on the free list */
1610 static void yaffs_free_obj(struct yaffs_obj *obj)
1611 {
1612         struct yaffs_dev *dev;
1613
1614         if (!obj) {
1615                 BUG();
1616                 return;
1617         }
1618         dev = obj->my_dev;
1619         yaffs_trace(YAFFS_TRACE_OS, "FreeObject %p inode %p",
1620                 obj, obj->my_inode);
1621         if (obj->parent)
1622                 BUG();
1623         if (!list_empty(&obj->siblings))
1624                 BUG();
1625
1626         if (obj->my_inode) {
1627                 /* We're still hooked up to a cached inode.
1628                  * Don't delete now, but mark for later deletion
1629                  */
1630                 obj->defered_free = 1;
1631                 return;
1632         }
1633
1634         yaffs_unhash_obj(obj);
1635
1636         yaffs_free_raw_obj(dev, obj);
1637         dev->n_obj--;
1638         dev->checkpoint_blocks_required = 0;    /* force recalculation */
1639 }
1640
1641 void yaffs_handle_defered_free(struct yaffs_obj *obj)
1642 {
1643         if (obj->defered_free)
1644                 yaffs_free_obj(obj);
1645 }
1646
1647 static int yaffs_generic_obj_del(struct yaffs_obj *in)
1648 {
1649         /* Iinvalidate the file's data in the cache, without flushing. */
1650         yaffs_invalidate_whole_cache(in);
1651
1652         if (in->my_dev->param.is_yaffs2 && in->parent != in->my_dev->del_dir) {
1653                 /* Move to unlinked directory so we have a deletion record */
1654                 yaffs_change_obj_name(in, in->my_dev->del_dir, _Y("deleted"), 0,
1655                                       0);
1656         }
1657
1658         yaffs_remove_obj_from_dir(in);
1659         yaffs_chunk_del(in->my_dev, in->hdr_chunk, 1, __LINE__);
1660         in->hdr_chunk = 0;
1661
1662         yaffs_free_obj(in);
1663         return YAFFS_OK;
1664
1665 }
1666
1667 static void yaffs_soft_del_file(struct yaffs_obj *obj)
1668 {
1669         if (!obj->deleted ||
1670             obj->variant_type != YAFFS_OBJECT_TYPE_FILE ||
1671             obj->soft_del)
1672                 return;
1673
1674         if (obj->n_data_chunks <= 0) {
1675                 /* Empty file with no duplicate object headers,
1676                  * just delete it immediately */
1677                 yaffs_free_tnode(obj->my_dev, obj->variant.file_variant.top);
1678                 obj->variant.file_variant.top = NULL;
1679                 yaffs_trace(YAFFS_TRACE_TRACING,
1680                         "yaffs: Deleting empty file %d",
1681                         obj->obj_id);
1682                 yaffs_generic_obj_del(obj);
1683         } else {
1684                 yaffs_soft_del_worker(obj,
1685                                       obj->variant.file_variant.top,
1686                                       obj->variant.
1687                                       file_variant.top_level, 0);
1688                 obj->soft_del = 1;
1689         }
1690 }
1691
1692 /* Pruning removes any part of the file structure tree that is beyond the
1693  * bounds of the file (ie that does not point to chunks).
1694  *
1695  * A file should only get pruned when its size is reduced.
1696  *
1697  * Before pruning, the chunks must be pulled from the tree and the
1698  * level 0 tnode entries must be zeroed out.
1699  * Could also use this for file deletion, but that's probably better handled
1700  * by a special case.
1701  *
1702  * This function is recursive. For levels > 0 the function is called again on
1703  * any sub-tree. For level == 0 we just check if the sub-tree has data.
1704  * If there is no data in a subtree then it is pruned.
1705  */
1706
1707 static struct yaffs_tnode *yaffs_prune_worker(struct yaffs_dev *dev,
1708                                               struct yaffs_tnode *tn, u32 level,
1709                                               int del0)
1710 {
1711         int i;
1712         int has_data;
1713
1714         if (!tn)
1715                 return tn;
1716
1717         has_data = 0;
1718
1719         if (level > 0) {
1720                 for (i = 0; i < YAFFS_NTNODES_INTERNAL; i++) {
1721                         if (tn->internal[i]) {
1722                                 tn->internal[i] =
1723                                     yaffs_prune_worker(dev,
1724                                                 tn->internal[i],
1725                                                 level - 1,
1726                                                 (i == 0) ? del0 : 1);
1727                         }
1728
1729                         if (tn->internal[i])
1730                                 has_data++;
1731                 }
1732         } else {
1733                 int tnode_size_u32 = dev->tnode_size / sizeof(u32);
1734                 u32 *map = (u32 *) tn;
1735
1736                 for (i = 0; !has_data && i < tnode_size_u32; i++) {
1737                         if (map[i])
1738                                 has_data++;
1739                 }
1740         }
1741
1742         if (has_data == 0 && del0) {
1743                 /* Free and return NULL */
1744                 yaffs_free_tnode(dev, tn);
1745                 tn = NULL;
1746         }
1747         return tn;
1748 }
1749
1750 static int yaffs_prune_tree(struct yaffs_dev *dev,
1751                             struct yaffs_file_var *file_struct)
1752 {
1753         int i;
1754         int has_data;
1755         int done = 0;
1756         struct yaffs_tnode *tn;
1757
1758         if (file_struct->top_level < 1)
1759                 return YAFFS_OK;
1760
1761         file_struct->top =
1762            yaffs_prune_worker(dev, file_struct->top, file_struct->top_level, 0);
1763
1764         /* Now we have a tree with all the non-zero branches NULL but
1765          * the height is the same as it was.
1766          * Let's see if we can trim internal tnodes to shorten the tree.
1767          * We can do this if only the 0th element in the tnode is in use
1768          * (ie all the non-zero are NULL)
1769          */
1770
1771         while (file_struct->top_level && !done) {
1772                 tn = file_struct->top;
1773
1774                 has_data = 0;
1775                 for (i = 1; i < YAFFS_NTNODES_INTERNAL; i++) {
1776                         if (tn->internal[i])
1777                                 has_data++;
1778                 }
1779
1780                 if (!has_data) {
1781                         file_struct->top = tn->internal[0];
1782                         file_struct->top_level--;
1783                         yaffs_free_tnode(dev, tn);
1784                 } else {
1785                         done = 1;
1786                 }
1787         }
1788
1789         return YAFFS_OK;
1790 }
1791
1792 /*-------------------- End of File Structure functions.-------------------*/
1793
1794 /* alloc_empty_obj gets us a clean Object.*/
1795 static struct yaffs_obj *yaffs_alloc_empty_obj(struct yaffs_dev *dev)
1796 {
1797         struct yaffs_obj *obj = yaffs_alloc_raw_obj(dev);
1798
1799         if (!obj)
1800                 return obj;
1801
1802         dev->n_obj++;
1803
1804         /* Now sweeten it up... */
1805
1806         memset(obj, 0, sizeof(struct yaffs_obj));
1807         obj->being_created = 1;
1808
1809         obj->my_dev = dev;
1810         obj->hdr_chunk = 0;
1811         obj->variant_type = YAFFS_OBJECT_TYPE_UNKNOWN;
1812         INIT_LIST_HEAD(&(obj->hard_links));
1813         INIT_LIST_HEAD(&(obj->hash_link));
1814         INIT_LIST_HEAD(&obj->siblings);
1815
1816         /* Now make the directory sane */
1817         if (dev->root_dir) {
1818                 obj->parent = dev->root_dir;
1819                 list_add(&(obj->siblings),
1820                          &dev->root_dir->variant.dir_variant.children);
1821         }
1822
1823         /* Add it to the lost and found directory.
1824          * NB Can't put root or lost-n-found in lost-n-found so
1825          * check if lost-n-found exists first
1826          */
1827         if (dev->lost_n_found)
1828                 yaffs_add_obj_to_dir(dev->lost_n_found, obj);
1829
1830         obj->being_created = 0;
1831
1832         dev->checkpoint_blocks_required = 0;    /* force recalculation */
1833
1834         return obj;
1835 }
1836
1837 static int yaffs_find_nice_bucket(struct yaffs_dev *dev)
1838 {
1839         int i;
1840         int l = 999;
1841         int lowest = 999999;
1842
1843         /* Search for the shortest list or one that
1844          * isn't too long.
1845          */
1846
1847         for (i = 0; i < 10 && lowest > 4; i++) {
1848                 dev->bucket_finder++;
1849                 dev->bucket_finder %= YAFFS_NOBJECT_BUCKETS;
1850                 if (dev->obj_bucket[dev->bucket_finder].count < lowest) {
1851                         lowest = dev->obj_bucket[dev->bucket_finder].count;
1852                         l = dev->bucket_finder;
1853                 }
1854         }
1855
1856         return l;
1857 }
1858
1859 static int yaffs_new_obj_id(struct yaffs_dev *dev)
1860 {
1861         int bucket = yaffs_find_nice_bucket(dev);
1862         int found = 0;
1863         struct list_head *i;
1864         u32 n = (u32) bucket;
1865
1866         /* Now find an object value that has not already been taken
1867          * by scanning the list.
1868          */
1869
1870         while (!found) {
1871                 found = 1;
1872                 n += YAFFS_NOBJECT_BUCKETS;
1873                 if (1 || dev->obj_bucket[bucket].count > 0) {
1874                         list_for_each(i, &dev->obj_bucket[bucket].list) {
1875                                 /* If there is already one in the list */
1876                                 if (i && list_entry(i, struct yaffs_obj,
1877                                                     hash_link)->obj_id == n) {
1878                                         found = 0;
1879                                 }
1880                         }
1881                 }
1882         }
1883         return n;
1884 }
1885
1886 static void yaffs_hash_obj(struct yaffs_obj *in)
1887 {
1888         int bucket = yaffs_hash_fn(in->obj_id);
1889         struct yaffs_dev *dev = in->my_dev;
1890
1891         list_add(&in->hash_link, &dev->obj_bucket[bucket].list);
1892         dev->obj_bucket[bucket].count++;
1893 }
1894
1895 struct yaffs_obj *yaffs_find_by_number(struct yaffs_dev *dev, u32 number)
1896 {
1897         int bucket = yaffs_hash_fn(number);
1898         struct list_head *i;
1899         struct yaffs_obj *in;
1900
1901         list_for_each(i, &dev->obj_bucket[bucket].list) {
1902                 /* Look if it is in the list */
1903                 in = list_entry(i, struct yaffs_obj, hash_link);
1904                 if (in->obj_id == number) {
1905                         /* Don't show if it is defered free */
1906                         if (in->defered_free)
1907                                 return NULL;
1908                         return in;
1909                 }
1910         }
1911
1912         return NULL;
1913 }
1914
1915 static struct yaffs_obj *yaffs_new_obj(struct yaffs_dev *dev, int number,
1916                                 enum yaffs_obj_type type)
1917 {
1918         struct yaffs_obj *the_obj = NULL;
1919         struct yaffs_tnode *tn = NULL;
1920
1921         if (number < 0)
1922                 number = yaffs_new_obj_id(dev);
1923
1924         if (type == YAFFS_OBJECT_TYPE_FILE) {
1925                 tn = yaffs_get_tnode(dev);
1926                 if (!tn)
1927                         return NULL;
1928         }
1929
1930         the_obj = yaffs_alloc_empty_obj(dev);
1931         if (!the_obj) {
1932                 if (tn)
1933                         yaffs_free_tnode(dev, tn);
1934                 return NULL;
1935         }
1936
1937         the_obj->fake = 0;
1938         the_obj->rename_allowed = 1;
1939         the_obj->unlink_allowed = 1;
1940         the_obj->obj_id = number;
1941         yaffs_hash_obj(the_obj);
1942         the_obj->variant_type = type;
1943         yaffs_load_current_time(the_obj, 1, 1);
1944
1945         switch (type) {
1946         case YAFFS_OBJECT_TYPE_FILE:
1947                 the_obj->variant.file_variant.file_size = 0;
1948                 the_obj->variant.file_variant.scanned_size = 0;
1949                 the_obj->variant.file_variant.shrink_size =
1950                                                 yaffs_max_file_size(dev);
1951                 the_obj->variant.file_variant.top_level = 0;
1952                 the_obj->variant.file_variant.top = tn;
1953                 break;
1954         case YAFFS_OBJECT_TYPE_DIRECTORY:
1955                 INIT_LIST_HEAD(&the_obj->variant.dir_variant.children);
1956                 INIT_LIST_HEAD(&the_obj->variant.dir_variant.dirty);
1957                 break;
1958         case YAFFS_OBJECT_TYPE_SYMLINK:
1959         case YAFFS_OBJECT_TYPE_HARDLINK:
1960         case YAFFS_OBJECT_TYPE_SPECIAL:
1961                 /* No action required */
1962                 break;
1963         case YAFFS_OBJECT_TYPE_UNKNOWN:
1964                 /* todo this should not happen */
1965                 break;
1966         }
1967         return the_obj;
1968 }
1969
1970 static struct yaffs_obj *yaffs_create_fake_dir(struct yaffs_dev *dev,
1971                                                int number, u32 mode)
1972 {
1973
1974         struct yaffs_obj *obj =
1975             yaffs_new_obj(dev, number, YAFFS_OBJECT_TYPE_DIRECTORY);
1976
1977         if (!obj)
1978                 return NULL;
1979
1980         obj->fake = 1;  /* it is fake so it might not use NAND */
1981         obj->rename_allowed = 0;
1982         obj->unlink_allowed = 0;
1983         obj->deleted = 0;
1984         obj->unlinked = 0;
1985         obj->yst_mode = mode;
1986         obj->my_dev = dev;
1987         obj->hdr_chunk = 0;     /* Not a valid chunk. */
1988         return obj;
1989
1990 }
1991
1992
1993 static void yaffs_init_tnodes_and_objs(struct yaffs_dev *dev)
1994 {
1995         int i;
1996
1997         dev->n_obj = 0;
1998         dev->n_tnodes = 0;
1999         yaffs_init_raw_tnodes_and_objs(dev);
2000
2001         for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
2002                 INIT_LIST_HEAD(&dev->obj_bucket[i].list);
2003                 dev->obj_bucket[i].count = 0;
2004         }
2005 }
2006
2007 struct yaffs_obj *yaffs_find_or_create_by_number(struct yaffs_dev *dev,
2008                                                  int number,
2009                                                  enum yaffs_obj_type type)
2010 {
2011         struct yaffs_obj *the_obj = NULL;
2012
2013         if (number > 0)
2014                 the_obj = yaffs_find_by_number(dev, number);
2015
2016         if (!the_obj)
2017                 the_obj = yaffs_new_obj(dev, number, type);
2018
2019         return the_obj;
2020
2021 }
2022
2023 YCHAR *yaffs_clone_str(const YCHAR *str)
2024 {
2025         YCHAR *new_str = NULL;
2026         int len;
2027
2028         if (!str)
2029                 str = _Y("");
2030
2031         len = strnlen(str, YAFFS_MAX_ALIAS_LENGTH);
2032         new_str = kmalloc((len + 1) * sizeof(YCHAR), GFP_NOFS);
2033         if (new_str) {
2034                 strncpy(new_str, str, len);
2035                 new_str[len] = 0;
2036         }
2037         return new_str;
2038
2039 }
2040 /*
2041  *yaffs_update_parent() handles fixing a directories mtime and ctime when a new
2042  * link (ie. name) is created or deleted in the directory.
2043  *
2044  * ie.
2045  *   create dir/a : update dir's mtime/ctime
2046  *   rm dir/a:   update dir's mtime/ctime
2047  *   modify dir/a: don't update dir's mtimme/ctime
2048  *
2049  * This can be handled immediately or defered. Defering helps reduce the number
2050  * of updates when many files in a directory are changed within a brief period.
2051  *
2052  * If the directory updating is defered then yaffs_update_dirty_dirs must be
2053  * called periodically.
2054  */
2055
2056 static void yaffs_update_parent(struct yaffs_obj *obj)
2057 {
2058         struct yaffs_dev *dev;
2059
2060         if (!obj)
2061                 return;
2062         dev = obj->my_dev;
2063         obj->dirty = 1;
2064         yaffs_load_current_time(obj, 0, 1);
2065         if (dev->param.defered_dir_update) {
2066                 struct list_head *link = &obj->variant.dir_variant.dirty;
2067
2068                 if (list_empty(link)) {
2069                         list_add(link, &dev->dirty_dirs);
2070                         yaffs_trace(YAFFS_TRACE_BACKGROUND,
2071                           "Added object %d to dirty directories",
2072                            obj->obj_id);
2073                 }
2074
2075         } else {
2076                 yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
2077         }
2078 }
2079
2080 void yaffs_update_dirty_dirs(struct yaffs_dev *dev)
2081 {
2082         struct list_head *link;
2083         struct yaffs_obj *obj;
2084         struct yaffs_dir_var *d_s;
2085         union yaffs_obj_var *o_v;
2086
2087         yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update dirty directories");
2088
2089         while (!list_empty(&dev->dirty_dirs)) {
2090                 link = dev->dirty_dirs.next;
2091                 list_del_init(link);
2092
2093                 d_s = list_entry(link, struct yaffs_dir_var, dirty);
2094                 o_v = list_entry(d_s, union yaffs_obj_var, dir_variant);
2095                 obj = list_entry(o_v, struct yaffs_obj, variant);
2096
2097                 yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update directory %d",
2098                         obj->obj_id);
2099
2100                 if (obj->dirty)
2101                         yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
2102         }
2103 }
2104
2105 /*
2106  * Mknod (create) a new object.
2107  * equiv_obj only has meaning for a hard link;
2108  * alias_str only has meaning for a symlink.
2109  * rdev only has meaning for devices (a subset of special objects)
2110  */
2111
2112 static struct yaffs_obj *yaffs_create_obj(enum yaffs_obj_type type,
2113                                           struct yaffs_obj *parent,
2114                                           const YCHAR *name,
2115                                           u32 mode,
2116                                           u32 uid,
2117                                           u32 gid,
2118                                           struct yaffs_obj *equiv_obj,
2119                                           const YCHAR *alias_str, u32 rdev)
2120 {
2121         struct yaffs_obj *in;
2122         YCHAR *str = NULL;
2123         struct yaffs_dev *dev = parent->my_dev;
2124
2125         /* Check if the entry exists.
2126          * If it does then fail the call since we don't want a dup. */
2127         if (yaffs_find_by_name(parent, name))
2128                 return NULL;
2129
2130         if (type == YAFFS_OBJECT_TYPE_SYMLINK) {
2131                 str = yaffs_clone_str(alias_str);
2132                 if (!str)
2133                         return NULL;
2134         }
2135
2136         in = yaffs_new_obj(dev, -1, type);
2137
2138         if (!in) {
2139                 kfree(str);
2140                 return NULL;
2141         }
2142
2143         in->hdr_chunk = 0;
2144         in->valid = 1;
2145         in->variant_type = type;
2146
2147         in->yst_mode = mode;
2148
2149         yaffs_attribs_init(in, gid, uid, rdev);
2150
2151         in->n_data_chunks = 0;
2152
2153         yaffs_set_obj_name(in, name);
2154         in->dirty = 1;
2155
2156         yaffs_add_obj_to_dir(parent, in);
2157
2158         in->my_dev = parent->my_dev;
2159
2160         switch (type) {
2161         case YAFFS_OBJECT_TYPE_SYMLINK:
2162                 in->variant.symlink_variant.alias = str;
2163                 break;
2164         case YAFFS_OBJECT_TYPE_HARDLINK:
2165                 in->variant.hardlink_variant.equiv_obj = equiv_obj;
2166                 in->variant.hardlink_variant.equiv_id = equiv_obj->obj_id;
2167                 list_add(&in->hard_links, &equiv_obj->hard_links);
2168                 break;
2169         case YAFFS_OBJECT_TYPE_FILE:
2170         case YAFFS_OBJECT_TYPE_DIRECTORY:
2171         case YAFFS_OBJECT_TYPE_SPECIAL:
2172         case YAFFS_OBJECT_TYPE_UNKNOWN:
2173                 /* do nothing */
2174                 break;
2175         }
2176
2177         if (yaffs_update_oh(in, name, 0, 0, 0, NULL) < 0) {
2178                 /* Could not create the object header, fail */
2179                 yaffs_del_obj(in);
2180                 in = NULL;
2181         }
2182
2183         if (in)
2184                 yaffs_update_parent(parent);
2185
2186         return in;
2187 }
2188
2189 struct yaffs_obj *yaffs_create_file(struct yaffs_obj *parent,
2190                                     const YCHAR *name, u32 mode, u32 uid,
2191                                     u32 gid)
2192 {
2193         return yaffs_create_obj(YAFFS_OBJECT_TYPE_FILE, parent, name, mode,
2194                                 uid, gid, NULL, NULL, 0);
2195 }
2196
2197 struct yaffs_obj *yaffs_create_dir(struct yaffs_obj *parent, const YCHAR *name,
2198                                    u32 mode, u32 uid, u32 gid)
2199 {
2200         return yaffs_create_obj(YAFFS_OBJECT_TYPE_DIRECTORY, parent, name,
2201                                 mode, uid, gid, NULL, NULL, 0);
2202 }
2203
2204 struct yaffs_obj *yaffs_create_special(struct yaffs_obj *parent,
2205                                        const YCHAR *name, u32 mode, u32 uid,
2206                                        u32 gid, u32 rdev)
2207 {
2208         return yaffs_create_obj(YAFFS_OBJECT_TYPE_SPECIAL, parent, name, mode,
2209                                 uid, gid, NULL, NULL, rdev);
2210 }
2211
2212 struct yaffs_obj *yaffs_create_symlink(struct yaffs_obj *parent,
2213                                        const YCHAR *name, u32 mode, u32 uid,
2214                                        u32 gid, const YCHAR *alias)
2215 {
2216         return yaffs_create_obj(YAFFS_OBJECT_TYPE_SYMLINK, parent, name, mode,
2217                                 uid, gid, NULL, alias, 0);
2218 }
2219
2220 /* yaffs_link_obj returns the object id of the equivalent object.*/
2221 struct yaffs_obj *yaffs_link_obj(struct yaffs_obj *parent, const YCHAR * name,
2222                                  struct yaffs_obj *equiv_obj)
2223 {
2224         /* Get the real object in case we were fed a hard link obj */
2225         equiv_obj = yaffs_get_equivalent_obj(equiv_obj);
2226
2227         if (yaffs_create_obj(YAFFS_OBJECT_TYPE_HARDLINK,
2228                         parent, name, 0, 0, 0,
2229                         equiv_obj, NULL, 0))
2230                 return equiv_obj;
2231
2232         return NULL;
2233
2234 }
2235
2236
2237
2238 /*---------------------- Block Management and Page Allocation -------------*/
2239
2240 static void yaffs_deinit_blocks(struct yaffs_dev *dev)
2241 {
2242         if (dev->block_info_alt && dev->block_info)
2243                 vfree(dev->block_info);
2244         else
2245                 kfree(dev->block_info);
2246
2247         dev->block_info_alt = 0;
2248
2249         dev->block_info = NULL;
2250
2251         if (dev->chunk_bits_alt && dev->chunk_bits)
2252                 vfree(dev->chunk_bits);
2253         else
2254                 kfree(dev->chunk_bits);
2255         dev->chunk_bits_alt = 0;
2256         dev->chunk_bits = NULL;
2257 }
2258
2259 static int yaffs_init_blocks(struct yaffs_dev *dev)
2260 {
2261         int n_blocks = dev->internal_end_block - dev->internal_start_block + 1;
2262
2263         dev->block_info = NULL;
2264         dev->chunk_bits = NULL;
2265         dev->alloc_block = -1;  /* force it to get a new one */
2266
2267         /* If the first allocation strategy fails, thry the alternate one */
2268         dev->block_info =
2269                 kmalloc(n_blocks * sizeof(struct yaffs_block_info), GFP_NOFS);
2270         if (!dev->block_info) {
2271                 dev->block_info =
2272                     vmalloc(n_blocks * sizeof(struct yaffs_block_info));
2273                 dev->block_info_alt = 1;
2274         } else {
2275                 dev->block_info_alt = 0;
2276         }
2277
2278         if (!dev->block_info)
2279                 goto alloc_error;
2280
2281         /* Set up dynamic blockinfo stuff. Round up bytes. */
2282         dev->chunk_bit_stride = (dev->param.chunks_per_block + 7) / 8;
2283         dev->chunk_bits =
2284                 kmalloc(dev->chunk_bit_stride * n_blocks, GFP_NOFS);
2285         if (!dev->chunk_bits) {
2286                 dev->chunk_bits =
2287                     vmalloc(dev->chunk_bit_stride * n_blocks);
2288                 dev->chunk_bits_alt = 1;
2289         } else {
2290                 dev->chunk_bits_alt = 0;
2291         }
2292         if (!dev->chunk_bits)
2293                 goto alloc_error;
2294
2295
2296         memset(dev->block_info, 0, n_blocks * sizeof(struct yaffs_block_info));
2297         memset(dev->chunk_bits, 0, dev->chunk_bit_stride * n_blocks);
2298         return YAFFS_OK;
2299
2300 alloc_error:
2301         yaffs_deinit_blocks(dev);
2302         return YAFFS_FAIL;
2303 }
2304
2305
2306 void yaffs_block_became_dirty(struct yaffs_dev *dev, int block_no)
2307 {
2308         struct yaffs_block_info *bi = yaffs_get_block_info(dev, block_no);
2309         int erased_ok = 0;
2310         int i;
2311
2312         /* If the block is still healthy erase it and mark as clean.
2313          * If the block has had a data failure, then retire it.
2314          */
2315
2316         yaffs_trace(YAFFS_TRACE_GC | YAFFS_TRACE_ERASE,
2317                 "yaffs_block_became_dirty block %d state %d %s",
2318                 block_no, bi->block_state,
2319                 (bi->needs_retiring) ? "needs retiring" : "");
2320
2321         yaffs2_clear_oldest_dirty_seq(dev, bi);
2322
2323         bi->block_state = YAFFS_BLOCK_STATE_DIRTY;
2324
2325         /* If this is the block being garbage collected then stop gc'ing */
2326         if (block_no == dev->gc_block)
2327                 dev->gc_block = 0;
2328
2329         /* If this block is currently the best candidate for gc
2330          * then drop as a candidate */
2331         if (block_no == dev->gc_dirtiest) {
2332                 dev->gc_dirtiest = 0;
2333                 dev->gc_pages_in_use = 0;
2334         }
2335
2336         if (!bi->needs_retiring) {
2337                 yaffs2_checkpt_invalidate(dev);
2338                 erased_ok = yaffs_erase_block(dev, block_no);
2339                 if (!erased_ok) {
2340                         dev->n_erase_failures++;
2341                         yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2342                           "**>> Erasure failed %d", block_no);
2343                 }
2344         }
2345
2346         /* Verify erasure if needed */
2347         if (erased_ok &&
2348             ((yaffs_trace_mask & YAFFS_TRACE_ERASE) ||
2349              !yaffs_skip_verification(dev))) {
2350                 for (i = 0; i < dev->param.chunks_per_block; i++) {
2351                         if (!yaffs_check_chunk_erased(dev,
2352                                 block_no * dev->param.chunks_per_block + i)) {
2353                                 yaffs_trace(YAFFS_TRACE_ERROR,
2354                                         ">>Block %d erasure supposedly OK, but chunk %d not erased",
2355                                         block_no, i);
2356                         }
2357                 }
2358         }
2359
2360         if (!erased_ok) {
2361                 /* We lost a block of free space */
2362                 dev->n_free_chunks -= dev->param.chunks_per_block;
2363                 yaffs_retire_block(dev, block_no);
2364                 yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2365                         "**>> Block %d retired", block_no);
2366                 return;
2367         }
2368
2369         /* Clean it up... */
2370         bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
2371         bi->seq_number = 0;
2372         dev->n_erased_blocks++;
2373         bi->pages_in_use = 0;
2374         bi->soft_del_pages = 0;
2375         bi->has_shrink_hdr = 0;
2376         bi->skip_erased_check = 1;      /* Clean, so no need to check */
2377         bi->gc_prioritise = 0;
2378         bi->has_summary = 0;
2379
2380         yaffs_clear_chunk_bits(dev, block_no);
2381
2382         yaffs_trace(YAFFS_TRACE_ERASE, "Erased block %d", block_no);
2383 }
2384
2385 static inline int yaffs_gc_process_chunk(struct yaffs_dev *dev,
2386                                         struct yaffs_block_info *bi,
2387                                         int old_chunk, u8 *buffer)
2388 {
2389         int new_chunk;
2390         int mark_flash = 1;
2391         struct yaffs_ext_tags tags;
2392         struct yaffs_obj *object;
2393         int matching_chunk;
2394         int ret_val = YAFFS_OK;
2395
2396         memset(&tags, 0, sizeof(tags));
2397         yaffs_rd_chunk_tags_nand(dev, old_chunk,
2398                                  buffer, &tags);
2399         object = yaffs_find_by_number(dev, tags.obj_id);
2400
2401         yaffs_trace(YAFFS_TRACE_GC_DETAIL,
2402                 "Collecting chunk in block %d, %d %d %d ",
2403                 dev->gc_chunk, tags.obj_id,
2404                 tags.chunk_id, tags.n_bytes);
2405
2406         if (object && !yaffs_skip_verification(dev)) {
2407                 if (tags.chunk_id == 0)
2408                         matching_chunk =
2409                             object->hdr_chunk;
2410                 else if (object->soft_del)
2411                         /* Defeat the test */
2412                         matching_chunk = old_chunk;
2413                 else
2414                         matching_chunk =
2415                             yaffs_find_chunk_in_file
2416                             (object, tags.chunk_id,
2417                              NULL);
2418
2419                 if (old_chunk != matching_chunk)
2420                         yaffs_trace(YAFFS_TRACE_ERROR,
2421                                 "gc: page in gc mismatch: %d %d %d %d",
2422                                 old_chunk,
2423                                 matching_chunk,
2424                                 tags.obj_id,
2425                                 tags.chunk_id);
2426         }
2427
2428         if (!object) {
2429                 yaffs_trace(YAFFS_TRACE_ERROR,
2430                         "page %d in gc has no object: %d %d %d ",
2431                         old_chunk,
2432                         tags.obj_id, tags.chunk_id,
2433                         tags.n_bytes);
2434         }
2435
2436         if (object &&
2437             object->deleted &&
2438             object->soft_del && tags.chunk_id != 0) {
2439                 /* Data chunk in a soft deleted file,
2440                  * throw it away.
2441                  * It's a soft deleted data chunk,
2442                  * No need to copy this, just forget
2443                  * about it and fix up the object.
2444                  */
2445
2446                 /* Free chunks already includes
2447                  * softdeleted chunks, how ever this
2448                  * chunk is going to soon be really
2449                  * deleted which will increment free
2450                  * chunks. We have to decrement free
2451                  * chunks so this works out properly.
2452                  */
2453                 dev->n_free_chunks--;
2454                 bi->soft_del_pages--;
2455
2456                 object->n_data_chunks--;
2457                 if (object->n_data_chunks <= 0) {
2458                         /* remeber to clean up obj */
2459                         dev->gc_cleanup_list[dev->n_clean_ups] = tags.obj_id;
2460                         dev->n_clean_ups++;
2461                 }
2462                 mark_flash = 0;
2463         } else if (object) {
2464                 /* It's either a data chunk in a live
2465                  * file or an ObjectHeader, so we're
2466                  * interested in it.
2467                  * NB Need to keep the ObjectHeaders of
2468                  * deleted files until the whole file
2469                  * has been deleted off
2470                  */
2471                 tags.serial_number++;
2472                 dev->n_gc_copies++;
2473
2474                 if (tags.chunk_id == 0) {
2475                         /* It is an object Id,
2476                          * We need to nuke the
2477                          * shrinkheader flags since its
2478                          * work is done.
2479                          * Also need to clean up
2480                          * shadowing.
2481                          */
2482                         struct yaffs_obj_hdr *oh;
2483                         oh = (struct yaffs_obj_hdr *) buffer;
2484
2485                         oh->is_shrink = 0;
2486                         tags.extra_is_shrink = 0;
2487                         oh->shadows_obj = 0;
2488                         oh->inband_shadowed_obj_id = 0;
2489                         tags.extra_shadows = 0;
2490
2491                         /* Update file size */
2492                         if (object->variant_type == YAFFS_OBJECT_TYPE_FILE) {
2493                                 yaffs_oh_size_load(oh,
2494                                     object->variant.file_variant.file_size);
2495                                 tags.extra_file_size =
2496                                     object->variant.file_variant.file_size;
2497                         }
2498
2499                         yaffs_verify_oh(object, oh, &tags, 1);
2500                         new_chunk =
2501                             yaffs_write_new_chunk(dev, (u8 *) oh, &tags, 1);
2502                 } else {
2503                         new_chunk =
2504                             yaffs_write_new_chunk(dev, buffer, &tags, 1);
2505                 }
2506
2507                 if (new_chunk < 0) {
2508                         ret_val = YAFFS_FAIL;
2509                 } else {
2510
2511                         /* Now fix up the Tnodes etc. */
2512
2513                         if (tags.chunk_id == 0) {
2514                                 /* It's a header */
2515                                 object->hdr_chunk = new_chunk;
2516                                 object->serial = tags.serial_number;
2517                         } else {
2518                                 /* It's a data chunk */
2519                                 yaffs_put_chunk_in_file(object, tags.chunk_id,
2520                                                         new_chunk, 0);
2521                         }
2522                 }
2523         }
2524         if (ret_val == YAFFS_OK)
2525                 yaffs_chunk_del(dev, old_chunk, mark_flash, __LINE__);
2526         return ret_val;
2527 }
2528
2529 static int yaffs_gc_block(struct yaffs_dev *dev, int block, int whole_block)
2530 {
2531         int old_chunk;
2532         int ret_val = YAFFS_OK;
2533         int i;
2534         int is_checkpt_block;
2535         int max_copies;
2536         int chunks_before = yaffs_get_erased_chunks(dev);
2537         int chunks_after;
2538         struct yaffs_block_info *bi = yaffs_get_block_info(dev, block);
2539
2540         is_checkpt_block = (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT);
2541
2542         yaffs_trace(YAFFS_TRACE_TRACING,
2543                 "Collecting block %d, in use %d, shrink %d, whole_block %d",
2544                 block, bi->pages_in_use, bi->has_shrink_hdr,
2545                 whole_block);
2546
2547         /*yaffs_verify_free_chunks(dev); */
2548
2549         if (bi->block_state == YAFFS_BLOCK_STATE_FULL)
2550                 bi->block_state = YAFFS_BLOCK_STATE_COLLECTING;
2551
2552         bi->has_shrink_hdr = 0; /* clear the flag so that the block can erase */
2553
2554         dev->gc_disable = 1;
2555
2556         yaffs_summary_gc(dev, block);
2557
2558         if (is_checkpt_block || !yaffs_still_some_chunks(dev, block)) {
2559                 yaffs_trace(YAFFS_TRACE_TRACING,
2560                         "Collecting block %d that has no chunks in use",
2561                         block);
2562                 yaffs_block_became_dirty(dev, block);
2563         } else {
2564
2565                 u8 *buffer = yaffs_get_temp_buffer(dev);
2566
2567                 yaffs_verify_blk(dev, bi, block);
2568
2569                 max_copies = (whole_block) ? dev->param.chunks_per_block : 5;
2570                 old_chunk = block * dev->param.chunks_per_block + dev->gc_chunk;
2571
2572                 for (/* init already done */ ;
2573                      ret_val == YAFFS_OK &&
2574                      dev->gc_chunk < dev->param.chunks_per_block &&
2575                      (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) &&
2576                      max_copies > 0;
2577                      dev->gc_chunk++, old_chunk++) {
2578                         if (yaffs_check_chunk_bit(dev, block, dev->gc_chunk)) {
2579                                 /* Page is in use and might need to be copied */
2580                                 max_copies--;
2581                                 ret_val = yaffs_gc_process_chunk(dev, bi,
2582                                                         old_chunk, buffer);
2583                         }
2584                 }
2585                 yaffs_release_temp_buffer(dev, buffer);
2586         }
2587
2588         yaffs_verify_collected_blk(dev, bi, block);
2589
2590         if (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
2591                 /*
2592                  * The gc did not complete. Set block state back to FULL
2593                  * because checkpointing does not restore gc.
2594                  */
2595                 bi->block_state = YAFFS_BLOCK_STATE_FULL;
2596         } else {
2597                 /* The gc completed. */
2598                 /* Do any required cleanups */
2599                 for (i = 0; i < dev->n_clean_ups; i++) {
2600                         /* Time to delete the file too */
2601                         struct yaffs_obj *object =
2602                             yaffs_find_by_number(dev, dev->gc_cleanup_list[i]);
2603                         if (object) {
2604                                 yaffs_free_tnode(dev,
2605                                           object->variant.file_variant.top);
2606                                 object->variant.file_variant.top = NULL;
2607                                 yaffs_trace(YAFFS_TRACE_GC,
2608                                         "yaffs: About to finally delete object %d",
2609                                         object->obj_id);
2610                                 yaffs_generic_obj_del(object);
2611                                 object->my_dev->n_deleted_files--;
2612                         }
2613
2614                 }
2615                 chunks_after = yaffs_get_erased_chunks(dev);
2616                 if (chunks_before >= chunks_after)
2617                         yaffs_trace(YAFFS_TRACE_GC,
2618                                 "gc did not increase free chunks before %d after %d",
2619                                 chunks_before, chunks_after);
2620                 dev->gc_block = 0;
2621                 dev->gc_chunk = 0;
2622                 dev->n_clean_ups = 0;
2623         }
2624
2625         dev->gc_disable = 0;
2626
2627         return ret_val;
2628 }
2629
2630 /*
2631  * find_gc_block() selects the dirtiest block (or close enough)
2632  * for garbage collection.
2633  */
2634
2635 static unsigned yaffs_find_gc_block(struct yaffs_dev *dev,
2636                                     int aggressive, int background)
2637 {
2638         int i;
2639         int iterations;
2640         unsigned selected = 0;
2641         int prioritised = 0;
2642         int prioritised_exist = 0;
2643         struct yaffs_block_info *bi;
2644         int threshold;
2645
2646         /* First let's see if we need to grab a prioritised block */
2647         if (dev->has_pending_prioritised_gc && !aggressive) {
2648                 dev->gc_dirtiest = 0;
2649                 bi = dev->block_info;
2650                 for (i = dev->internal_start_block;
2651                      i <= dev->internal_end_block && !selected; i++) {
2652
2653                         if (bi->gc_prioritise) {
2654                                 prioritised_exist = 1;
2655                                 if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
2656                                     yaffs_block_ok_for_gc(dev, bi)) {
2657                                         selected = i;
2658                                         prioritised = 1;
2659                                 }
2660                         }
2661                         bi++;
2662                 }
2663
2664                 /*
2665                  * If there is a prioritised block and none was selected then
2666                  * this happened because there is at least one old dirty block
2667                  * gumming up the works. Let's gc the oldest dirty block.
2668                  */
2669
2670                 if (prioritised_exist &&
2671                     !selected && dev->oldest_dirty_block > 0)
2672                         selected = dev->oldest_dirty_block;
2673
2674                 if (!prioritised_exist) /* None found, so we can clear this */
2675                         dev->has_pending_prioritised_gc = 0;
2676         }
2677
2678         /* If we're doing aggressive GC then we are happy to take a less-dirty
2679          * block, and search harder.
2680          * else (leasurely gc), then we only bother to do this if the
2681          * block has only a few pages in use.
2682          */
2683
2684         if (!selected) {
2685                 int pages_used;
2686                 int n_blocks =
2687                     dev->internal_end_block - dev->internal_start_block + 1;
2688                 if (aggressive) {
2689                         threshold = dev->param.chunks_per_block;
2690                         iterations = n_blocks;
2691                 } else {
2692                         int max_threshold;
2693
2694                         if (background)
2695                                 max_threshold = dev->param.chunks_per_block / 2;
2696                         else
2697                                 max_threshold = dev->param.chunks_per_block / 8;
2698
2699                         if (max_threshold < YAFFS_GC_PASSIVE_THRESHOLD)
2700                                 max_threshold = YAFFS_GC_PASSIVE_THRESHOLD;
2701
2702                         threshold = background ? (dev->gc_not_done + 2) * 2 : 0;
2703                         if (threshold < YAFFS_GC_PASSIVE_THRESHOLD)
2704                                 threshold = YAFFS_GC_PASSIVE_THRESHOLD;
2705                         if (threshold > max_threshold)
2706                                 threshold = max_threshold;
2707
2708                         iterations = n_blocks / 16 + 1;
2709                         if (iterations > 100)
2710                                 iterations = 100;
2711                 }
2712
2713                 for (i = 0;
2714                      i < iterations &&
2715                      (dev->gc_dirtiest < 1 ||
2716                       dev->gc_pages_in_use > YAFFS_GC_GOOD_ENOUGH);
2717                      i++) {
2718                         dev->gc_block_finder++;
2719                         if (dev->gc_block_finder < dev->internal_start_block ||
2720                             dev->gc_block_finder > dev->internal_end_block)
2721                                 dev->gc_block_finder =
2722                                     dev->internal_start_block;
2723
2724                         bi = yaffs_get_block_info(dev, dev->gc_block_finder);
2725
2726                         pages_used = bi->pages_in_use - bi->soft_del_pages;
2727
2728                         if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
2729                             pages_used < dev->param.chunks_per_block &&
2730                             (dev->gc_dirtiest < 1 ||
2731                              pages_used < dev->gc_pages_in_use) &&
2732                             yaffs_block_ok_for_gc(dev, bi)) {
2733                                 dev->gc_dirtiest = dev->gc_block_finder;
2734                                 dev->gc_pages_in_use = pages_used;
2735                         }
2736                 }
2737
2738                 if (dev->gc_dirtiest > 0 && dev->gc_pages_in_use <= threshold)
2739                         selected = dev->gc_dirtiest;
2740         }
2741
2742         /*
2743          * If nothing has been selected for a while, try the oldest dirty
2744          * because that's gumming up the works.
2745          */
2746
2747         if (!selected && dev->param.is_yaffs2 &&
2748             dev->gc_not_done >= (background ? 10 : 20)) {
2749                 yaffs2_find_oldest_dirty_seq(dev);
2750                 if (dev->oldest_dirty_block > 0) {
2751                         selected = dev->oldest_dirty_block;
2752                         dev->gc_dirtiest = selected;
2753                         dev->oldest_dirty_gc_count++;
2754                         bi = yaffs_get_block_info(dev, selected);
2755                         dev->gc_pages_in_use =
2756                             bi->pages_in_use - bi->soft_del_pages;
2757                 } else {
2758                         dev->gc_not_done = 0;
2759                 }
2760         }
2761
2762         if (selected) {
2763                 yaffs_trace(YAFFS_TRACE_GC,
2764                         "GC Selected block %d with %d free, prioritised:%d",
2765                         selected,
2766                         dev->param.chunks_per_block - dev->gc_pages_in_use,
2767                         prioritised);
2768
2769                 dev->n_gc_blocks++;
2770                 if (background)
2771                         dev->bg_gcs++;
2772
2773                 dev->gc_dirtiest = 0;
2774                 dev->gc_pages_in_use = 0;
2775                 dev->gc_not_done = 0;
2776                 if (dev->refresh_skip > 0)
2777                         dev->refresh_skip--;
2778         } else {
2779                 dev->gc_not_done++;
2780                 yaffs_trace(YAFFS_TRACE_GC,
2781                         "GC none: finder %d skip %d threshold %d dirtiest %d using %d oldest %d%s",
2782                         dev->gc_block_finder, dev->gc_not_done, threshold,
2783                         dev->gc_dirtiest, dev->gc_pages_in_use,
2784                         dev->oldest_dirty_block, background ? " bg" : "");
2785         }
2786
2787         return selected;
2788 }
2789
2790 /* New garbage collector
2791  * If we're very low on erased blocks then we do aggressive garbage collection
2792  * otherwise we do "leasurely" garbage collection.
2793  * Aggressive gc looks further (whole array) and will accept less dirty blocks.
2794  * Passive gc only inspects smaller areas and only accepts more dirty blocks.
2795  *
2796  * The idea is to help clear out space in a more spread-out manner.
2797  * Dunno if it really does anything useful.
2798  */
2799 static int yaffs_check_gc(struct yaffs_dev *dev, int background)
2800 {
2801         int aggressive = 0;
2802         int gc_ok = YAFFS_OK;
2803         int max_tries = 0;
2804         int min_erased;
2805         int erased_chunks;
2806         int checkpt_block_adjust;
2807
2808         if (dev->param.gc_control_fn &&
2809                 (dev->param.gc_control_fn(dev) & 1) == 0)
2810                 return YAFFS_OK;
2811
2812         if (dev->gc_disable)
2813                 /* Bail out so we don't get recursive gc */
2814                 return YAFFS_OK;
2815
2816         /* This loop should pass the first time.
2817          * Only loops here if the collection does not increase space.
2818          */
2819
2820         do {
2821                 max_tries++;
2822
2823                 checkpt_block_adjust = yaffs_calc_checkpt_blocks_required(dev);
2824
2825                 min_erased =
2826                     dev->param.n_reserved_blocks + checkpt_block_adjust + 1;
2827                 erased_chunks =
2828                     dev->n_erased_blocks * dev->param.chunks_per_block;
2829
2830                 /* If we need a block soon then do aggressive gc. */
2831                 if (dev->n_erased_blocks < min_erased)
2832                         aggressive = 1;
2833                 else {
2834                         if (!background
2835                             && erased_chunks > (dev->n_free_chunks / 4))
2836                                 break;
2837
2838                         if (dev->gc_skip > 20)
2839                                 dev->gc_skip = 20;
2840                         if (erased_chunks < dev->n_free_chunks / 2 ||
2841                             dev->gc_skip < 1 || background)
2842                                 aggressive = 0;
2843                         else {
2844                                 dev->gc_skip--;
2845                                 break;
2846                         }
2847                 }
2848
2849                 dev->gc_skip = 5;
2850
2851                 /* If we don't already have a block being gc'd then see if we
2852                  * should start another */
2853
2854                 if (dev->gc_block < 1 && !aggressive) {
2855                         dev->gc_block = yaffs2_find_refresh_block(dev);
2856                         dev->gc_chunk = 0;
2857                         dev->n_clean_ups = 0;
2858                 }
2859                 if (dev->gc_block < 1) {
2860                         dev->gc_block =
2861                             yaffs_find_gc_block(dev, aggressive, background);
2862                         dev->gc_chunk = 0;
2863                         dev->n_clean_ups = 0;
2864                 }
2865
2866                 if (dev->gc_block > 0) {
2867                         dev->all_gcs++;
2868                         if (!aggressive)
2869                                 dev->passive_gc_count++;
2870
2871                         yaffs_trace(YAFFS_TRACE_GC,
2872                                 "yaffs: GC n_erased_blocks %d aggressive %d",
2873                                 dev->n_erased_blocks, aggressive);
2874
2875                         gc_ok = yaffs_gc_block(dev, dev->gc_block, aggressive);
2876                 }
2877
2878                 if (dev->n_erased_blocks < (dev->param.n_reserved_blocks) &&
2879                     dev->gc_block > 0) {
2880                         yaffs_trace(YAFFS_TRACE_GC,
2881                                 "yaffs: GC !!!no reclaim!!! n_erased_blocks %d after try %d block %d",
2882                                 dev->n_erased_blocks, max_tries,
2883                                 dev->gc_block);
2884                 }
2885         } while ((dev->n_erased_blocks < dev->param.n_reserved_blocks) &&
2886                  (dev->gc_block > 0) && (max_tries < 2));
2887
2888         return aggressive ? gc_ok : YAFFS_OK;
2889 }
2890
2891 /*
2892  * yaffs_bg_gc()
2893  * Garbage collects. Intended to be called from a background thread.
2894  * Returns non-zero if at least half the free chunks are erased.
2895  */
2896 int yaffs_bg_gc(struct yaffs_dev *dev, unsigned urgency)
2897 {
2898         int erased_chunks = dev->n_erased_blocks * dev->param.chunks_per_block;
2899
2900         yaffs_trace(YAFFS_TRACE_BACKGROUND, "Background gc %u", urgency);
2901
2902         yaffs_check_gc(dev, 1);
2903         return erased_chunks > dev->n_free_chunks / 2;
2904 }
2905
2906 /*-------------------- Data file manipulation -----------------*/
2907
2908 static int yaffs_rd_data_obj(struct yaffs_obj *in, int inode_chunk, u8 * buffer)
2909 {
2910         int nand_chunk = yaffs_find_chunk_in_file(in, inode_chunk, NULL);
2911
2912         if (nand_chunk >= 0)
2913                 return yaffs_rd_chunk_tags_nand(in->my_dev, nand_chunk,
2914                                                 buffer, NULL);
2915         else {
2916                 yaffs_trace(YAFFS_TRACE_NANDACCESS,
2917                         "Chunk %d not found zero instead",
2918                         nand_chunk);
2919                 /* get sane (zero) data if you read a hole */
2920                 memset(buffer, 0, in->my_dev->data_bytes_per_chunk);
2921                 return 0;
2922         }
2923
2924 }
2925
2926 void yaffs_chunk_del(struct yaffs_dev *dev, int chunk_id, int mark_flash,
2927                      int lyn)
2928 {
2929         int block;
2930         int page;
2931         struct yaffs_ext_tags tags;
2932         struct yaffs_block_info *bi;
2933
2934         if (chunk_id <= 0)
2935                 return;
2936
2937         dev->n_deletions++;
2938         block = chunk_id / dev->param.chunks_per_block;
2939         page = chunk_id % dev->param.chunks_per_block;
2940
2941         if (!yaffs_check_chunk_bit(dev, block, page))
2942                 yaffs_trace(YAFFS_TRACE_VERIFY,
2943                         "Deleting invalid chunk %d", chunk_id);
2944
2945         bi = yaffs_get_block_info(dev, block);
2946
2947         yaffs2_update_oldest_dirty_seq(dev, block, bi);
2948
2949         yaffs_trace(YAFFS_TRACE_DELETION,
2950                 "line %d delete of chunk %d",
2951                 lyn, chunk_id);
2952
2953         if (!dev->param.is_yaffs2 && mark_flash &&
2954             bi->block_state != YAFFS_BLOCK_STATE_COLLECTING) {
2955
2956                 memset(&tags, 0, sizeof(tags));
2957                 tags.is_deleted = 1;
2958                 yaffs_wr_chunk_tags_nand(dev, chunk_id, NULL, &tags);
2959                 yaffs_handle_chunk_update(dev, chunk_id, &tags);
2960         } else {
2961                 dev->n_unmarked_deletions++;
2962         }
2963
2964         /* Pull out of the management area.
2965          * If the whole block became dirty, this will kick off an erasure.
2966          */
2967         if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING ||
2968             bi->block_state == YAFFS_BLOCK_STATE_FULL ||
2969             bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCAN ||
2970             bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
2971                 dev->n_free_chunks++;
2972                 yaffs_clear_chunk_bit(dev, block, page);
2973                 bi->pages_in_use--;
2974
2975                 if (bi->pages_in_use == 0 &&
2976                     !bi->has_shrink_hdr &&
2977                     bi->block_state != YAFFS_BLOCK_STATE_ALLOCATING &&
2978                     bi->block_state != YAFFS_BLOCK_STATE_NEEDS_SCAN) {
2979                         yaffs_block_became_dirty(dev, block);
2980                 }
2981         }
2982 }
2983
2984 static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
2985                              const u8 *buffer, int n_bytes, int use_reserve)
2986 {
2987         /* Find old chunk Need to do this to get serial number
2988          * Write new one and patch into tree.
2989          * Invalidate old tags.
2990          */
2991
2992         int prev_chunk_id;
2993         struct yaffs_ext_tags prev_tags;
2994         int new_chunk_id;
2995         struct yaffs_ext_tags new_tags;
2996         struct yaffs_dev *dev = in->my_dev;
2997
2998         yaffs_check_gc(dev, 0);
2999
3000         /* Get the previous chunk at this location in the file if it exists.
3001          * If it does not exist then put a zero into the tree. This creates
3002          * the tnode now, rather than later when it is harder to clean up.
3003          */
3004         prev_chunk_id = yaffs_find_chunk_in_file(in, inode_chunk, &prev_tags);
3005         if (prev_chunk_id < 1 &&
3006             !yaffs_put_chunk_in_file(in, inode_chunk, 0, 0))
3007                 return 0;
3008
3009         /* Set up new tags */
3010         memset(&new_tags, 0, sizeof(new_tags));
3011
3012         new_tags.chunk_id = inode_chunk;
3013         new_tags.obj_id = in->obj_id;
3014         new_tags.serial_number =
3015             (prev_chunk_id > 0) ? prev_tags.serial_number + 1 : 1;
3016         new_tags.n_bytes = n_bytes;
3017
3018         if (n_bytes < 1 || n_bytes > dev->param.total_bytes_per_chunk) {
3019                 yaffs_trace(YAFFS_TRACE_ERROR,
3020                   "Writing %d bytes to chunk!!!!!!!!!",
3021                    n_bytes);
3022                 BUG();
3023         }
3024
3025         new_chunk_id =
3026             yaffs_write_new_chunk(dev, buffer, &new_tags, use_reserve);
3027
3028         if (new_chunk_id > 0) {
3029                 yaffs_put_chunk_in_file(in, inode_chunk, new_chunk_id, 0);
3030
3031                 if (prev_chunk_id > 0)
3032                         yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
3033
3034                 yaffs_verify_file_sane(in);
3035         }
3036         return new_chunk_id;
3037
3038 }
3039
3040
3041
3042 static int yaffs_do_xattrib_mod(struct yaffs_obj *obj, int set,
3043                                 const YCHAR *name, const void *value, int size,
3044                                 int flags)
3045 {
3046         struct yaffs_xattr_mod xmod;
3047         int result;
3048
3049         xmod.set = set;
3050         xmod.name = name;
3051         xmod.data = value;
3052         xmod.size = size;
3053         xmod.flags = flags;
3054         xmod.result = -ENOSPC;
3055
3056         result = yaffs_update_oh(obj, NULL, 0, 0, 0, &xmod);
3057
3058         if (result > 0)
3059                 return xmod.result;
3060         else
3061                 return -ENOSPC;
3062 }
3063
3064 static int yaffs_apply_xattrib_mod(struct yaffs_obj *obj, char *buffer,
3065                                    struct yaffs_xattr_mod *xmod)
3066 {
3067         int retval = 0;
3068         int x_offs = sizeof(struct yaffs_obj_hdr);
3069         struct yaffs_dev *dev = obj->my_dev;
3070         int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
3071         char *x_buffer = buffer + x_offs;
3072
3073         if (xmod->set)
3074                 retval =
3075                     nval_set(x_buffer, x_size, xmod->name, xmod->data,
3076                              xmod->size, xmod->flags);
3077         else
3078                 retval = nval_del(x_buffer, x_size, xmod->name);
3079
3080         obj->has_xattr = nval_hasvalues(x_buffer, x_size);
3081         obj->xattr_known = 1;
3082         xmod->result = retval;
3083
3084         return retval;
3085 }
3086
3087 static int yaffs_do_xattrib_fetch(struct yaffs_obj *obj, const YCHAR *name,
3088                                   void *value, int size)
3089 {
3090         char *buffer = NULL;
3091         int result;
3092         struct yaffs_ext_tags tags;
3093         struct yaffs_dev *dev = obj->my_dev;
3094         int x_offs = sizeof(struct yaffs_obj_hdr);
3095         int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
3096         char *x_buffer;
3097         int retval = 0;
3098
3099         if (obj->hdr_chunk < 1)
3100                 return -ENODATA;
3101
3102         /* If we know that the object has no xattribs then don't do all the
3103          * reading and parsing.
3104          */
3105         if (obj->xattr_known && !obj->has_xattr) {
3106                 if (name)
3107                         return -ENODATA;
3108                 else
3109                         return 0;
3110         }
3111
3112         buffer = (char *)yaffs_get_temp_buffer(dev);
3113         if (!buffer)
3114                 return -ENOMEM;
3115
3116         result =
3117             yaffs_rd_chunk_tags_nand(dev, obj->hdr_chunk, (u8 *) buffer, &tags);
3118
3119         if (result != YAFFS_OK)
3120                 retval = -ENOENT;
3121         else {
3122                 x_buffer = buffer + x_offs;
3123
3124                 if (!obj->xattr_known) {
3125                         obj->has_xattr = nval_hasvalues(x_buffer, x_size);
3126                         obj->xattr_known = 1;
3127                 }
3128
3129                 if (name)
3130                         retval = nval_get(x_buffer, x_size, name, value, size);
3131                 else
3132                         retval = nval_list(x_buffer, x_size, value, size);
3133         }
3134         yaffs_release_temp_buffer(dev, (u8 *) buffer);
3135         return retval;
3136 }
3137
3138 int yaffs_set_xattrib(struct yaffs_obj *obj, const YCHAR * name,
3139                       const void *value, int size, int flags)
3140 {
3141         return yaffs_do_xattrib_mod(obj, 1, name, value, size, flags);
3142 }
3143
3144 int yaffs_remove_xattrib(struct yaffs_obj *obj, const YCHAR * name)
3145 {
3146         return yaffs_do_xattrib_mod(obj, 0, name, NULL, 0, 0);
3147 }
3148
3149 int yaffs_get_xattrib(struct yaffs_obj *obj, const YCHAR * name, void *value,
3150                       int size)
3151 {
3152         return yaffs_do_xattrib_fetch(obj, name, value, size);
3153 }
3154
3155 int yaffs_list_xattrib(struct yaffs_obj *obj, char *buffer, int size)
3156 {
3157         return yaffs_do_xattrib_fetch(obj, NULL, buffer, size);
3158 }
3159
3160 static void yaffs_check_obj_details_loaded(struct yaffs_obj *in)
3161 {
3162         u8 *buf;
3163         struct yaffs_obj_hdr *oh;
3164         struct yaffs_dev *dev;
3165         struct yaffs_ext_tags tags;
3166         int result;
3167         int alloc_failed = 0;
3168
3169         if (!in || !in->lazy_loaded || in->hdr_chunk < 1)
3170                 return;
3171
3172         dev = in->my_dev;
3173         in->lazy_loaded = 0;
3174         buf = yaffs_get_temp_buffer(dev);
3175
3176         result = yaffs_rd_chunk_tags_nand(dev, in->hdr_chunk, buf, &tags);
3177         oh = (struct yaffs_obj_hdr *)buf;
3178
3179         in->yst_mode = oh->yst_mode;
3180         yaffs_load_attribs(in, oh);
3181         yaffs_set_obj_name_from_oh(in, oh);
3182
3183         if (in->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
3184                 in->variant.symlink_variant.alias =
3185                     yaffs_clone_str(oh->alias);
3186                 if (!in->variant.symlink_variant.alias)
3187                         alloc_failed = 1;       /* Not returned */
3188         }
3189         yaffs_release_temp_buffer(dev, buf);
3190 }
3191
3192 static void yaffs_load_name_from_oh(struct yaffs_dev *dev, YCHAR *name,
3193                                     const YCHAR *oh_name, int buff_size)
3194 {
3195 #ifdef CONFIG_YAFFS_AUTO_UNICODE
3196         if (dev->param.auto_unicode) {
3197                 if (*oh_name) {
3198                         /* It is an ASCII name, do an ASCII to
3199                          * unicode conversion */
3200                         const char *ascii_oh_name = (const char *)oh_name;
3201                         int n = buff_size - 1;
3202                         while (n > 0 && *ascii_oh_name) {
3203                                 *name = *ascii_oh_name;
3204                                 name++;
3205                                 ascii_oh_name++;
3206                                 n--;
3207                         }
3208                 } else {
3209                         strncpy(name, oh_name + 1, buff_size - 1);
3210                 }
3211         } else {
3212 #else
3213         (void) dev;
3214         {
3215 #endif
3216                 strncpy(name, oh_name, buff_size - 1);
3217         }
3218 }
3219
3220 static void yaffs_load_oh_from_name(struct yaffs_dev *dev, YCHAR *oh_name,
3221                                     const YCHAR *name)
3222 {
3223 #ifdef CONFIG_YAFFS_AUTO_UNICODE
3224
3225         int is_ascii;
3226         YCHAR *w;
3227
3228         if (dev->param.auto_unicode) {
3229
3230                 is_ascii = 1;
3231                 w = name;
3232
3233                 /* Figure out if the name will fit in ascii character set */
3234                 while (is_ascii && *w) {
3235                         if ((*w) & 0xff00)
3236                                 is_ascii = 0;
3237                         w++;
3238                 }
3239
3240                 if (is_ascii) {
3241                         /* It is an ASCII name, so convert unicode to ascii */
3242                         char *ascii_oh_name = (char *)oh_name;
3243                         int n = YAFFS_MAX_NAME_LENGTH - 1;
3244                         while (n > 0 && *name) {
3245                                 *ascii_oh_name = *name;
3246                                 name++;
3247                                 ascii_oh_name++;
3248                                 n--;
3249                         }
3250                 } else {
3251                         /* Unicode name, so save starting at the second YCHAR */
3252                         *oh_name = 0;
3253                         strncpy(oh_name + 1, name, YAFFS_MAX_NAME_LENGTH - 2);
3254                 }
3255         } else {
3256 #else
3257         dev = dev;
3258         {
3259 #endif
3260                 strncpy(oh_name, name, YAFFS_MAX_NAME_LENGTH - 1);
3261         }
3262 }
3263
3264 /* UpdateObjectHeader updates the header on NAND for an object.
3265  * If name is not NULL, then that new name is used.
3266  */
3267 int yaffs_update_oh(struct yaffs_obj *in, const YCHAR *name, int force,
3268                     int is_shrink, int shadows, struct yaffs_xattr_mod *xmod)
3269 {
3270
3271         struct yaffs_block_info *bi;
3272         struct yaffs_dev *dev = in->my_dev;
3273         int prev_chunk_id;
3274         int ret_val = 0;
3275         int result = 0;
3276         int new_chunk_id;
3277         struct yaffs_ext_tags new_tags;
3278         struct yaffs_ext_tags old_tags;
3279         const YCHAR *alias = NULL;
3280         u8 *buffer = NULL;
3281         YCHAR old_name[YAFFS_MAX_NAME_LENGTH + 1];
3282         struct yaffs_obj_hdr *oh = NULL;
3283         loff_t file_size = 0;
3284
3285         strcpy(old_name, _Y("silly old name"));
3286
3287         if (in->fake && in != dev->root_dir && !force && !xmod)
3288                 return ret_val;
3289
3290         yaffs_check_gc(dev, 0);
3291         yaffs_check_obj_details_loaded(in);
3292
3293         buffer = yaffs_get_temp_buffer(in->my_dev);
3294         oh = (struct yaffs_obj_hdr *)buffer;
3295
3296         prev_chunk_id = in->hdr_chunk;
3297
3298         if (prev_chunk_id > 0) {
3299                 result = yaffs_rd_chunk_tags_nand(dev, prev_chunk_id,
3300                                                   buffer, &old_tags);
3301
3302                 yaffs_verify_oh(in, oh, &old_tags, 0);
3303                 memcpy(old_name, oh->name, sizeof(oh->name));
3304                 memset(buffer, 0xff, sizeof(struct yaffs_obj_hdr));
3305         } else {
3306                 memset(buffer, 0xff, dev->data_bytes_per_chunk);
3307         }
3308
3309         oh->type = in->variant_type;
3310         oh->yst_mode = in->yst_mode;
3311         oh->shadows_obj = oh->inband_shadowed_obj_id = shadows;
3312
3313         yaffs_load_attribs_oh(oh, in);
3314
3315         if (in->parent)
3316                 oh->parent_obj_id = in->parent->obj_id;
3317         else
3318                 oh->parent_obj_id = 0;
3319
3320         if (name && *name) {
3321                 memset(oh->name, 0, sizeof(oh->name));
3322                 yaffs_load_oh_from_name(dev, oh->name, name);
3323         } else if (prev_chunk_id > 0) {
3324                 memcpy(oh->name, old_name, sizeof(oh->name));
3325         } else {
3326                 memset(oh->name, 0, sizeof(oh->name));
3327         }
3328
3329         oh->is_shrink = is_shrink;
3330
3331         switch (in->variant_type) {
3332         case YAFFS_OBJECT_TYPE_UNKNOWN:
3333                 /* Should not happen */
3334                 break;
3335         case YAFFS_OBJECT_TYPE_FILE:
3336                 if (oh->parent_obj_id != YAFFS_OBJECTID_DELETED &&
3337                     oh->parent_obj_id != YAFFS_OBJECTID_UNLINKED)
3338                         file_size = in->variant.file_variant.file_size;
3339                 yaffs_oh_size_load(oh, file_size);
3340                 break;
3341         case YAFFS_OBJECT_TYPE_HARDLINK:
3342                 oh->equiv_id = in->variant.hardlink_variant.equiv_id;
3343                 break;
3344         case YAFFS_OBJECT_TYPE_SPECIAL:
3345                 /* Do nothing */
3346                 break;
3347         case YAFFS_OBJECT_TYPE_DIRECTORY:
3348                 /* Do nothing */
3349                 break;
3350         case YAFFS_OBJECT_TYPE_SYMLINK:
3351                 alias = in->variant.symlink_variant.alias;
3352                 if (!alias)
3353                         alias = _Y("no alias");
3354                 strncpy(oh->alias, alias, YAFFS_MAX_ALIAS_LENGTH);
3355                 oh->alias[YAFFS_MAX_ALIAS_LENGTH] = 0;
3356                 break;
3357         }
3358
3359         /* process any xattrib modifications */
3360         if (xmod)
3361                 yaffs_apply_xattrib_mod(in, (char *)buffer, xmod);
3362
3363         /* Tags */
3364         memset(&new_tags, 0, sizeof(new_tags));
3365         in->serial++;
3366         new_tags.chunk_id = 0;
3367         new_tags.obj_id = in->obj_id;
3368         new_tags.serial_number = in->serial;
3369
3370         /* Add extra info for file header */
3371         new_tags.extra_available = 1;
3372         new_tags.extra_parent_id = oh->parent_obj_id;
3373         new_tags.extra_file_size = file_size;
3374         new_tags.extra_is_shrink = oh->is_shrink;
3375         new_tags.extra_equiv_id = oh->equiv_id;
3376         new_tags.extra_shadows = (oh->shadows_obj > 0) ? 1 : 0;
3377         new_tags.extra_obj_type = in->variant_type;
3378         yaffs_verify_oh(in, oh, &new_tags, 1);
3379
3380         /* Create new chunk in NAND */
3381         new_chunk_id =
3382             yaffs_write_new_chunk(dev, buffer, &new_tags,
3383                                   (prev_chunk_id > 0) ? 1 : 0);
3384
3385         if (buffer)
3386                 yaffs_release_temp_buffer(dev, buffer);
3387
3388         if (new_chunk_id < 0)
3389                 return new_chunk_id;
3390
3391         in->hdr_chunk = new_chunk_id;
3392
3393         if (prev_chunk_id > 0)
3394                 yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
3395
3396         if (!yaffs_obj_cache_dirty(in))
3397                 in->dirty = 0;
3398
3399         /* If this was a shrink, then mark the block
3400          * that the chunk lives on */
3401         if (is_shrink) {
3402                 bi = yaffs_get_block_info(in->my_dev,
3403                                           new_chunk_id /
3404                                           in->my_dev->param.chunks_per_block);
3405                 bi->has_shrink_hdr = 1;
3406         }
3407
3408
3409         return new_chunk_id;
3410 }
3411
3412 /*--------------------- File read/write ------------------------
3413  * Read and write have very similar structures.
3414  * In general the read/write has three parts to it
3415  * An incomplete chunk to start with (if the read/write is not chunk-aligned)
3416  * Some complete chunks
3417  * An incomplete chunk to end off with
3418  *
3419  * Curve-balls: the first chunk might also be the last chunk.
3420  */
3421
3422 int yaffs_file_rd(struct yaffs_obj *in, u8 * buffer, loff_t offset, int n_bytes)
3423 {
3424         int chunk;
3425         u32 start;
3426         int n_copy;
3427         int n = n_bytes;
3428         int n_done = 0;
3429         struct yaffs_cache *cache;
3430         struct yaffs_dev *dev;
3431
3432         dev = in->my_dev;
3433
3434         while (n > 0) {
3435                 yaffs_addr_to_chunk(dev, offset, &chunk, &start);
3436                 chunk++;
3437
3438                 /* OK now check for the curveball where the start and end are in
3439                  * the same chunk.
3440                  */
3441                 if ((start + n) < dev->data_bytes_per_chunk)
3442                         n_copy = n;
3443                 else
3444                         n_copy = dev->data_bytes_per_chunk - start;
3445
3446                 cache = yaffs_find_chunk_cache(in, chunk);
3447
3448                 /* If the chunk is already in the cache or it is less than
3449                  * a whole chunk or we're using inband tags then use the cache
3450                  * (if there is caching) else bypass the cache.
3451                  */
3452                 if (cache || n_copy != dev->data_bytes_per_chunk ||
3453                     dev->param.inband_tags) {
3454                         if (dev->param.n_caches > 0) {
3455
3456                                 /* If we can't find the data in the cache,
3457                                  * then load it up. */
3458
3459                                 if (!cache) {
3460                                         cache =
3461                                             yaffs_grab_chunk_cache(in->my_dev);
3462                                         cache->object = in;
3463                                         cache->chunk_id = chunk;
3464                                         cache->dirty = 0;
3465                                         cache->locked = 0;
3466                                         yaffs_rd_data_obj(in, chunk,
3467                                                           cache->data);
3468                                         cache->n_bytes = 0;
3469                                 }
3470
3471                                 yaffs_use_cache(dev, cache, 0);
3472
3473                                 cache->locked = 1;
3474
3475                                 memcpy(buffer, &cache->data[start], n_copy);
3476
3477                                 cache->locked = 0;
3478                         } else {
3479                                 /* Read into the local buffer then copy.. */
3480
3481                                 u8 *local_buffer =
3482                                     yaffs_get_temp_buffer(dev);
3483                                 yaffs_rd_data_obj(in, chunk, local_buffer);
3484
3485                                 memcpy(buffer, &local_buffer[start], n_copy);
3486
3487                                 yaffs_release_temp_buffer(dev, local_buffer);
3488                         }
3489                 } else {
3490                         /* A full chunk. Read directly into the buffer. */
3491                         yaffs_rd_data_obj(in, chunk, buffer);
3492                 }
3493                 n -= n_copy;
3494                 offset += n_copy;
3495                 buffer += n_copy;
3496                 n_done += n_copy;
3497         }
3498         return n_done;
3499 }
3500
3501 int yaffs_do_file_wr(struct yaffs_obj *in, const u8 *buffer, loff_t offset,
3502                      int n_bytes, int write_through)
3503 {
3504
3505         int chunk;
3506         u32 start;
3507         int n_copy;
3508         int n = n_bytes;
3509         int n_done = 0;
3510         int n_writeback;
3511         loff_t start_write = offset;
3512         int chunk_written = 0;
3513         u32 n_bytes_read;
3514         loff_t chunk_start;
3515         struct yaffs_dev *dev;
3516
3517         dev = in->my_dev;
3518
3519         while (n > 0 && chunk_written >= 0) {
3520                 yaffs_addr_to_chunk(dev, offset, &chunk, &start);
3521
3522                 if (((loff_t)chunk) *
3523                     dev->data_bytes_per_chunk + start != offset ||
3524                     start >= dev->data_bytes_per_chunk) {
3525                         yaffs_trace(YAFFS_TRACE_ERROR,
3526                                 "AddrToChunk of offset %lld gives chunk %d start %d",
3527                                 offset, chunk, start);
3528                 }
3529                 chunk++;        /* File pos to chunk in file offset */
3530
3531                 /* OK now check for the curveball where the start and end are in
3532                  * the same chunk.
3533                  */
3534
3535                 if ((start + n) < dev->data_bytes_per_chunk) {
3536                         n_copy = n;
3537
3538                         /* Now calculate how many bytes to write back....
3539                          * If we're overwriting and not writing to then end of
3540                          * file then we need to write back as much as was there
3541                          * before.
3542                          */
3543
3544                         chunk_start = (((loff_t)(chunk - 1)) *
3545                                         dev->data_bytes_per_chunk);
3546
3547                         if (chunk_start > in->variant.file_variant.file_size)
3548                                 n_bytes_read = 0;       /* Past end of file */
3549                         else
3550                                 n_bytes_read =
3551                                     in->variant.file_variant.file_size -
3552                                     chunk_start;
3553
3554                         if (n_bytes_read > dev->data_bytes_per_chunk)
3555                                 n_bytes_read = dev->data_bytes_per_chunk;
3556
3557                         n_writeback =
3558                             (n_bytes_read >
3559                              (start + n)) ? n_bytes_read : (start + n);
3560
3561                         if (n_writeback < 0 ||
3562                             n_writeback > dev->data_bytes_per_chunk)
3563                                 BUG();
3564
3565                 } else {
3566                         n_copy = dev->data_bytes_per_chunk - start;
3567                         n_writeback = dev->data_bytes_per_chunk;
3568                 }
3569
3570                 if (n_copy != dev->data_bytes_per_chunk ||
3571                     !dev->param.cache_bypass_aligned ||
3572                     dev->param.inband_tags) {
3573                         /* An incomplete start or end chunk (or maybe both
3574                          * start and end chunk), or we're using inband tags,
3575                          * or we're forcing writes through the cache,
3576                          * so we want to use the cache buffers.
3577                          */
3578                         if (dev->param.n_caches > 0) {
3579                                 struct yaffs_cache *cache;
3580
3581                                 /* If we can't find the data in the cache, then
3582                                  * load the cache */
3583                                 cache = yaffs_find_chunk_cache(in, chunk);
3584
3585                                 if (!cache &&
3586                                     yaffs_check_alloc_available(dev, 1)) {
3587                                         cache = yaffs_grab_chunk_cache(dev);
3588                                         cache->object = in;
3589                                         cache->chunk_id = chunk;
3590                                         cache->dirty = 0;
3591                                         cache->locked = 0;
3592                                         yaffs_rd_data_obj(in, chunk,
3593                                                           cache->data);
3594                                 } else if (cache &&
3595                                            !cache->dirty &&
3596                                            !yaffs_check_alloc_available(dev,
3597                                                                         1)) {
3598                                         /* Drop the cache if it was a read cache
3599                                          * item and no space check has been made
3600                                          * for it.
3601                                          */
3602                                         cache = NULL;
3603                                 }
3604
3605                                 if (cache) {
3606                                         yaffs_use_cache(dev, cache, 1);
3607                                         cache->locked = 1;
3608
3609                                         memcpy(&cache->data[start], buffer,
3610                                                n_copy);
3611
3612                                         cache->locked = 0;
3613                                         cache->n_bytes = n_writeback;
3614
3615                                         if (write_through) {
3616                                                 chunk_written =
3617                                                     yaffs_wr_data_obj
3618                                                     (cache->object,
3619                                                      cache->chunk_id,
3620                                                      cache->data,
3621                                                      cache->n_bytes, 1);
3622                                                 cache->dirty = 0;
3623                                         }
3624                                 } else {
3625                                         chunk_written = -1;     /* fail write */
3626                                 }
3627                         } else {
3628                                 /* An incomplete start or end chunk (or maybe
3629                                  * both start and end chunk). Read into the
3630                                  * local buffer then copy over and write back.
3631                                  */
3632
3633                                 u8 *local_buffer = yaffs_get_temp_buffer(dev);
3634
3635                                 yaffs_rd_data_obj(in, chunk, local_buffer);
3636                                 memcpy(&local_buffer[start], buffer, n_copy);
3637
3638                                 chunk_written =
3639                                     yaffs_wr_data_obj(in, chunk,
3640                                                       local_buffer,
3641                                                       n_writeback, 0);
3642
3643                                 yaffs_release_temp_buffer(dev, local_buffer);
3644                         }
3645                 } else {
3646                         /* A full chunk. Write directly from the buffer. */
3647
3648                         chunk_written =
3649                             yaffs_wr_data_obj(in, chunk, buffer,
3650                                               dev->data_bytes_per_chunk, 0);
3651
3652                         /* Since we've overwritten the cached data,
3653                          * we better invalidate it. */
3654                         yaffs_invalidate_chunk_cache(in, chunk);
3655                 }
3656
3657                 if (chunk_written >= 0) {
3658                         n -= n_copy;
3659                         offset += n_copy;
3660                         buffer += n_copy;
3661                         n_done += n_copy;
3662                 }
3663         }
3664
3665         /* Update file object */
3666
3667         if ((start_write + n_done) > in->variant.file_variant.file_size)
3668                 in->variant.file_variant.file_size = (start_write + n_done);
3669
3670         in->dirty = 1;
3671         return n_done;
3672 }
3673
3674 int yaffs_wr_file(struct yaffs_obj *in, const u8 *buffer, loff_t offset,
3675                   int n_bytes, int write_through)
3676 {
3677         yaffs2_handle_hole(in, offset);
3678         return yaffs_do_file_wr(in, buffer, offset, n_bytes, write_through);
3679 }
3680
3681 /* ---------------------- File resizing stuff ------------------ */
3682
3683 static void yaffs_prune_chunks(struct yaffs_obj *in, loff_t new_size)
3684 {
3685
3686         struct yaffs_dev *dev = in->my_dev;
3687         loff_t old_size = in->variant.file_variant.file_size;
3688         int i;
3689         int chunk_id;
3690         u32 dummy;
3691         int last_del;
3692         int start_del;
3693
3694         if (old_size > 0)
3695                 yaffs_addr_to_chunk(dev, old_size - 1, &last_del, &dummy);
3696         else
3697                 last_del = 0;
3698
3699         yaffs_addr_to_chunk(dev, new_size + dev->data_bytes_per_chunk - 1,
3700                                 &start_del, &dummy);
3701         last_del++;
3702         start_del++;
3703
3704         /* Delete backwards so that we don't end up with holes if
3705          * power is lost part-way through the operation.
3706          */
3707         for (i = last_del; i >= start_del; i--) {
3708                 /* NB this could be optimised somewhat,
3709                  * eg. could retrieve the tags and write them without
3710                  * using yaffs_chunk_del
3711                  */
3712
3713                 chunk_id = yaffs_find_del_file_chunk(in, i, NULL);
3714
3715                 if (chunk_id < 1)
3716                         continue;
3717
3718                 if (chunk_id <
3719                     (dev->internal_start_block * dev->param.chunks_per_block) ||
3720                     chunk_id >=
3721                     ((dev->internal_end_block + 1) *
3722                       dev->param.chunks_per_block)) {
3723                         yaffs_trace(YAFFS_TRACE_ALWAYS,
3724                                 "Found daft chunk_id %d for %d",
3725                                 chunk_id, i);
3726                 } else {
3727                         in->n_data_chunks--;
3728                         yaffs_chunk_del(dev, chunk_id, 1, __LINE__);
3729                 }
3730         }
3731 }
3732
3733 void yaffs_resize_file_down(struct yaffs_obj *obj, loff_t new_size)
3734 {
3735         int new_full;
3736         u32 new_partial;
3737         struct yaffs_dev *dev = obj->my_dev;
3738
3739         yaffs_addr_to_chunk(dev, new_size, &new_full, &new_partial);
3740
3741         yaffs_prune_chunks(obj, new_size);
3742
3743         if (new_partial != 0) {
3744                 int last_chunk = 1 + new_full;
3745                 u8 *local_buffer = yaffs_get_temp_buffer(dev);
3746
3747                 /* Rewrite the last chunk with its new size and zero pad */
3748                 yaffs_rd_data_obj(obj, last_chunk, local_buffer);
3749                 memset(local_buffer + new_partial, 0,
3750                        dev->data_bytes_per_chunk - new_partial);
3751
3752                 yaffs_wr_data_obj(obj, last_chunk, local_buffer,
3753                                   new_partial, 1);
3754
3755                 yaffs_release_temp_buffer(dev, local_buffer);
3756         }
3757
3758         obj->variant.file_variant.file_size = new_size;
3759
3760         yaffs_prune_tree(dev, &obj->variant.file_variant);
3761 }
3762
3763 int yaffs_resize_file(struct yaffs_obj *in, loff_t new_size)
3764 {
3765         struct yaffs_dev *dev = in->my_dev;
3766         loff_t old_size = in->variant.file_variant.file_size;
3767
3768         yaffs_flush_file_cache(in);
3769         yaffs_invalidate_whole_cache(in);
3770
3771         yaffs_check_gc(dev, 0);
3772
3773         if (in->variant_type != YAFFS_OBJECT_TYPE_FILE)
3774                 return YAFFS_FAIL;
3775
3776         if (new_size == old_size)
3777                 return YAFFS_OK;
3778
3779         if (new_size > old_size) {
3780                 yaffs2_handle_hole(in, new_size);
3781                 in->variant.file_variant.file_size = new_size;
3782         } else {
3783                 /* new_size < old_size */
3784                 yaffs_resize_file_down(in, new_size);
3785         }
3786
3787         /* Write a new object header to reflect the resize.
3788          * show we've shrunk the file, if need be
3789          * Do this only if the file is not in the deleted directories
3790          * and is not shadowed.
3791          */
3792         if (in->parent &&
3793             !in->is_shadowed &&
3794             in->parent->obj_id != YAFFS_OBJECTID_UNLINKED &&
3795             in->parent->obj_id != YAFFS_OBJECTID_DELETED)
3796                 yaffs_update_oh(in, NULL, 0, 0, 0, NULL);
3797
3798         return YAFFS_OK;
3799 }
3800
3801 int yaffs_flush_file(struct yaffs_obj *in, int update_time, int data_sync)
3802 {
3803         if (!in->dirty)
3804                 return YAFFS_OK;
3805
3806         yaffs_flush_file_cache(in);
3807
3808         if (data_sync)
3809                 return YAFFS_OK;
3810
3811         if (update_time)
3812                 yaffs_load_current_time(in, 0, 0);
3813
3814         return (yaffs_update_oh(in, NULL, 0, 0, 0, NULL) >= 0) ?
3815                                 YAFFS_OK : YAFFS_FAIL;
3816 }
3817
3818
3819 /* yaffs_del_file deletes the whole file data
3820  * and the inode associated with the file.
3821  * It does not delete the links associated with the file.
3822  */
3823 static int yaffs_unlink_file_if_needed(struct yaffs_obj *in)
3824 {
3825         int ret_val;
3826         int del_now = 0;
3827         struct yaffs_dev *dev = in->my_dev;
3828
3829         if (!in->my_inode)
3830                 del_now = 1;
3831
3832         if (del_now) {
3833                 ret_val =
3834                     yaffs_change_obj_name(in, in->my_dev->del_dir,
3835                                           _Y("deleted"), 0, 0);
3836                 yaffs_trace(YAFFS_TRACE_TRACING,
3837                         "yaffs: immediate deletion of file %d",
3838                         in->obj_id);
3839                 in->deleted = 1;
3840                 in->my_dev->n_deleted_files++;
3841                 if (dev->param.disable_soft_del || dev->param.is_yaffs2)
3842                         yaffs_resize_file(in, 0);
3843                 yaffs_soft_del_file(in);
3844         } else {
3845                 ret_val =
3846                     yaffs_change_obj_name(in, in->my_dev->unlinked_dir,
3847                                           _Y("unlinked"), 0, 0);
3848         }
3849         return ret_val;
3850 }
3851
3852 static int yaffs_del_file(struct yaffs_obj *in)
3853 {
3854         int ret_val = YAFFS_OK;
3855         int deleted;    /* Need to cache value on stack if in is freed */
3856         struct yaffs_dev *dev = in->my_dev;
3857
3858         if (dev->param.disable_soft_del || dev->param.is_yaffs2)
3859                 yaffs_resize_file(in, 0);
3860
3861         if (in->n_data_chunks > 0) {
3862                 /* Use soft deletion if there is data in the file.
3863                  * That won't be the case if it has been resized to zero.
3864                  */
3865                 if (!in->unlinked)
3866                         ret_val = yaffs_unlink_file_if_needed(in);
3867
3868                 deleted = in->deleted;
3869
3870                 if (ret_val == YAFFS_OK && in->unlinked && !in->deleted) {
3871                         in->deleted = 1;
3872                         deleted = 1;
3873                         in->my_dev->n_deleted_files++;
3874                         yaffs_soft_del_file(in);
3875                 }
3876                 return deleted ? YAFFS_OK : YAFFS_FAIL;
3877         } else {
3878                 /* The file has no data chunks so we toss it immediately */
3879                 yaffs_free_tnode(in->my_dev, in->variant.file_variant.top);
3880                 in->variant.file_variant.top = NULL;
3881                 yaffs_generic_obj_del(in);
3882
3883                 return YAFFS_OK;
3884         }
3885 }
3886
3887 int yaffs_is_non_empty_dir(struct yaffs_obj *obj)
3888 {
3889         return (obj &&
3890                 obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY) &&
3891                 !(list_empty(&obj->variant.dir_variant.children));
3892 }
3893
3894 static int yaffs_del_dir(struct yaffs_obj *obj)
3895 {
3896         /* First check that the directory is empty. */
3897         if (yaffs_is_non_empty_dir(obj))
3898                 return YAFFS_FAIL;
3899
3900         return yaffs_generic_obj_del(obj);
3901 }
3902
3903 static int yaffs_del_symlink(struct yaffs_obj *in)
3904 {
3905         kfree(in->variant.symlink_variant.alias);
3906         in->variant.symlink_variant.alias = NULL;
3907
3908         return yaffs_generic_obj_del(in);
3909 }
3910
3911 static int yaffs_del_link(struct yaffs_obj *in)
3912 {
3913         /* remove this hardlink from the list associated with the equivalent
3914          * object
3915          */
3916         list_del_init(&in->hard_links);
3917         return yaffs_generic_obj_del(in);
3918 }
3919
3920 int yaffs_del_obj(struct yaffs_obj *obj)
3921 {
3922         int ret_val = -1;
3923
3924         switch (obj->variant_type) {
3925         case YAFFS_OBJECT_TYPE_FILE:
3926                 ret_val = yaffs_del_file(obj);
3927                 break;
3928         case YAFFS_OBJECT_TYPE_DIRECTORY:
3929                 if (!list_empty(&obj->variant.dir_variant.dirty)) {
3930                         yaffs_trace(YAFFS_TRACE_BACKGROUND,
3931                                 "Remove object %d from dirty directories",
3932                                 obj->obj_id);
3933                         list_del_init(&obj->variant.dir_variant.dirty);
3934                 }
3935                 return yaffs_del_dir(obj);
3936                 break;
3937         case YAFFS_OBJECT_TYPE_SYMLINK:
3938                 ret_val = yaffs_del_symlink(obj);
3939                 break;
3940         case YAFFS_OBJECT_TYPE_HARDLINK:
3941                 ret_val = yaffs_del_link(obj);
3942                 break;
3943         case YAFFS_OBJECT_TYPE_SPECIAL:
3944                 ret_val = yaffs_generic_obj_del(obj);
3945                 break;
3946         case YAFFS_OBJECT_TYPE_UNKNOWN:
3947                 ret_val = 0;
3948                 break;          /* should not happen. */
3949         }
3950         return ret_val;
3951 }
3952
3953
3954 static void yaffs_empty_dir_to_dir(struct yaffs_obj *from_dir,
3955                                    struct yaffs_obj *to_dir)
3956 {
3957         struct yaffs_obj *obj;
3958         struct list_head *lh;
3959         struct list_head *n;
3960
3961         list_for_each_safe(lh, n, &from_dir->variant.dir_variant.children) {
3962                 obj = list_entry(lh, struct yaffs_obj, siblings);
3963                 yaffs_add_obj_to_dir(to_dir, obj);
3964         }
3965 }
3966
3967 struct yaffs_obj *yaffs_retype_obj(struct yaffs_obj *obj,
3968                                    enum yaffs_obj_type type)
3969 {
3970         /* Tear down the old variant */
3971         switch (obj->variant_type) {
3972         case YAFFS_OBJECT_TYPE_FILE:
3973                 /* Nuke file data */
3974                 yaffs_resize_file(obj, 0);
3975                 yaffs_free_tnode(obj->my_dev, obj->variant.file_variant.top);
3976                 obj->variant.file_variant.top = NULL;
3977                 break;
3978         case YAFFS_OBJECT_TYPE_DIRECTORY:
3979                 /* Put the children in lost and found. */
3980                 yaffs_empty_dir_to_dir(obj, obj->my_dev->lost_n_found);
3981                 if (!list_empty(&obj->variant.dir_variant.dirty))
3982                         list_del_init(&obj->variant.dir_variant.dirty);
3983                 break;
3984         case YAFFS_OBJECT_TYPE_SYMLINK:
3985                 /* Nuke symplink data */
3986                 kfree(obj->variant.symlink_variant.alias);
3987                 obj->variant.symlink_variant.alias = NULL;
3988                 break;
3989         case YAFFS_OBJECT_TYPE_HARDLINK:
3990                 list_del_init(&obj->hard_links);
3991                 break;
3992         default:
3993                 break;
3994         }
3995
3996         memset(&obj->variant, 0, sizeof(obj->variant));
3997
3998         /*Set up new variant if the memset is not enough. */
3999         switch (type) {
4000         case YAFFS_OBJECT_TYPE_DIRECTORY:
4001                 INIT_LIST_HEAD(&obj->variant.dir_variant.children);
4002                 INIT_LIST_HEAD(&obj->variant.dir_variant.dirty);
4003                 break;
4004         case YAFFS_OBJECT_TYPE_FILE:
4005         case YAFFS_OBJECT_TYPE_SYMLINK:
4006         case YAFFS_OBJECT_TYPE_HARDLINK:
4007         default:
4008                 break;
4009         }
4010
4011         obj->variant_type = type;
4012
4013         return obj;
4014
4015 }
4016
4017 static int yaffs_unlink_worker(struct yaffs_obj *obj)
4018 {
4019         int del_now = 0;
4020
4021         if (!obj)
4022                 return YAFFS_FAIL;
4023
4024         if (!obj->my_inode)
4025                 del_now = 1;
4026
4027         yaffs_update_parent(obj->parent);
4028
4029         if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
4030                 return yaffs_del_link(obj);
4031         } else if (!list_empty(&obj->hard_links)) {
4032                 /* Curve ball: We're unlinking an object that has a hardlink.
4033                  *
4034                  * This problem arises because we are not strictly following
4035                  * The Linux link/inode model.
4036                  *
4037                  * We can't really delete the object.
4038                  * Instead, we do the following:
4039                  * - Select a hardlink.
4040                  * - Unhook it from the hard links
4041                  * - Move it from its parent directory so that the rename works.
4042                  * - Rename the object to the hardlink's name.
4043                  * - Delete the hardlink
4044                  */
4045
4046                 struct yaffs_obj *hl;
4047                 struct yaffs_obj *parent;
4048                 int ret_val;
4049                 YCHAR name[YAFFS_MAX_NAME_LENGTH + 1];
4050
4051                 hl = list_entry(obj->hard_links.next, struct yaffs_obj,
4052                                 hard_links);
4053
4054                 yaffs_get_obj_name(hl, name, YAFFS_MAX_NAME_LENGTH + 1);
4055                 parent = hl->parent;
4056
4057                 list_del_init(&hl->hard_links);
4058
4059                 yaffs_add_obj_to_dir(obj->my_dev->unlinked_dir, hl);
4060
4061                 ret_val = yaffs_change_obj_name(obj, parent, name, 0, 0);
4062
4063                 if (ret_val == YAFFS_OK)
4064                         ret_val = yaffs_generic_obj_del(hl);
4065
4066                 return ret_val;
4067
4068         } else if (del_now) {
4069                 switch (obj->variant_type) {
4070                 case YAFFS_OBJECT_TYPE_FILE:
4071                         return yaffs_del_file(obj);
4072                         break;
4073                 case YAFFS_OBJECT_TYPE_DIRECTORY:
4074                         list_del_init(&obj->variant.dir_variant.dirty);
4075                         return yaffs_del_dir(obj);
4076                         break;
4077                 case YAFFS_OBJECT_TYPE_SYMLINK:
4078                         return yaffs_del_symlink(obj);
4079                         break;
4080                 case YAFFS_OBJECT_TYPE_SPECIAL:
4081                         return yaffs_generic_obj_del(obj);
4082                         break;
4083                 case YAFFS_OBJECT_TYPE_HARDLINK:
4084                 case YAFFS_OBJECT_TYPE_UNKNOWN:
4085                 default:
4086                         return YAFFS_FAIL;
4087                 }
4088         } else if (yaffs_is_non_empty_dir(obj)) {
4089                 return YAFFS_FAIL;
4090         } else {
4091                 return yaffs_change_obj_name(obj, obj->my_dev->unlinked_dir,
4092                                                 _Y("unlinked"), 0, 0);
4093         }
4094 }
4095
4096 static int yaffs_unlink_obj(struct yaffs_obj *obj)
4097 {
4098         if (obj && obj->unlink_allowed)
4099                 return yaffs_unlink_worker(obj);
4100
4101         return YAFFS_FAIL;
4102 }
4103
4104 int yaffs_unlinker(struct yaffs_obj *dir, const YCHAR *name)
4105 {
4106         struct yaffs_obj *obj;
4107
4108         obj = yaffs_find_by_name(dir, name);
4109         return yaffs_unlink_obj(obj);
4110 }
4111
4112 /* Note:
4113  * If old_name is NULL then we take old_dir as the object to be renamed.
4114  */
4115 int yaffs_rename_obj(struct yaffs_obj *old_dir, const YCHAR *old_name,
4116                      struct yaffs_obj *new_dir, const YCHAR *new_name)
4117 {
4118         struct yaffs_obj *obj = NULL;
4119         struct yaffs_obj *existing_target = NULL;
4120         int force = 0;
4121         int result;
4122         struct yaffs_dev *dev;
4123
4124         if (!old_dir || old_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4125                 BUG();
4126                 return YAFFS_FAIL;
4127         }
4128         if (!new_dir || new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4129                 BUG();
4130                 return YAFFS_FAIL;
4131         }
4132
4133         dev = old_dir->my_dev;
4134
4135 #ifdef CONFIG_YAFFS_CASE_INSENSITIVE
4136         /* Special case for case insemsitive systems.
4137          * While look-up is case insensitive, the name isn't.
4138          * Therefore we might want to change x.txt to X.txt
4139          */
4140         if (old_dir == new_dir &&
4141                 old_name && new_name &&
4142                 strcmp(old_name, new_name) == 0)
4143                 force = 1;
4144 #endif
4145
4146         if (strnlen(new_name, YAFFS_MAX_NAME_LENGTH + 1) >
4147             YAFFS_MAX_NAME_LENGTH)
4148                 /* ENAMETOOLONG */
4149                 return YAFFS_FAIL;
4150
4151         if (old_name)
4152                 obj = yaffs_find_by_name(old_dir, old_name);
4153         else{
4154                 obj = old_dir;
4155                 old_dir = obj->parent;
4156         }
4157
4158         if (obj && obj->rename_allowed) {
4159                 /* Now handle an existing target, if there is one */
4160                 existing_target = yaffs_find_by_name(new_dir, new_name);
4161                 if (yaffs_is_non_empty_dir(existing_target)) {
4162                         return YAFFS_FAIL;      /* ENOTEMPTY */
4163                 } else if (existing_target && existing_target != obj) {
4164                         /* Nuke the target first, using shadowing,
4165                          * but only if it isn't the same object.
4166                          *
4167                          * Note we must disable gc here otherwise it can mess
4168                          * up the shadowing.
4169                          *
4170                          */
4171                         dev->gc_disable = 1;
4172                         yaffs_change_obj_name(obj, new_dir, new_name, force,
4173                                               existing_target->obj_id);
4174                         existing_target->is_shadowed = 1;
4175                         yaffs_unlink_obj(existing_target);
4176                         dev->gc_disable = 0;
4177                 }
4178
4179                 result = yaffs_change_obj_name(obj, new_dir, new_name, 1, 0);
4180
4181                 yaffs_update_parent(old_dir);
4182                 if (new_dir != old_dir)
4183                         yaffs_update_parent(new_dir);
4184
4185                 return result;
4186         }
4187         return YAFFS_FAIL;
4188 }
4189
4190 /*----------------------- Initialisation Scanning ---------------------- */
4191
4192 void yaffs_handle_shadowed_obj(struct yaffs_dev *dev, int obj_id,
4193                                int backward_scanning)
4194 {
4195         struct yaffs_obj *obj;
4196
4197         if (backward_scanning) {
4198                 /* Handle YAFFS2 case (backward scanning)
4199                  * If the shadowed object exists then ignore.
4200                  */
4201                 obj = yaffs_find_by_number(dev, obj_id);
4202                 if (obj)
4203                         return;
4204         }
4205
4206         /* Let's create it (if it does not exist) assuming it is a file so that
4207          * it can do shrinking etc.
4208          * We put it in unlinked dir to be cleaned up after the scanning
4209          */
4210         obj =
4211             yaffs_find_or_create_by_number(dev, obj_id, YAFFS_OBJECT_TYPE_FILE);
4212         if (!obj)
4213                 return;
4214         obj->is_shadowed = 1;
4215         yaffs_add_obj_to_dir(dev->unlinked_dir, obj);
4216         obj->variant.file_variant.shrink_size = 0;
4217         obj->valid = 1;         /* So that we don't read any other info. */
4218 }
4219
4220 void yaffs_link_fixup(struct yaffs_dev *dev, struct list_head *hard_list)
4221 {
4222         struct list_head *lh;
4223         struct list_head *save;
4224         struct yaffs_obj *hl;
4225         struct yaffs_obj *in;
4226
4227         list_for_each_safe(lh, save, hard_list) {
4228                 hl = list_entry(lh, struct yaffs_obj, hard_links);
4229                 in = yaffs_find_by_number(dev,
4230                                         hl->variant.hardlink_variant.equiv_id);
4231
4232                 if (in) {
4233                         /* Add the hardlink pointers */
4234                         hl->variant.hardlink_variant.equiv_obj = in;
4235                         list_add(&hl->hard_links, &in->hard_links);
4236                 } else {
4237                         /* Todo Need to report/handle this better.
4238                          * Got a problem... hardlink to a non-existant object
4239                          */
4240                         hl->variant.hardlink_variant.equiv_obj = NULL;
4241                         INIT_LIST_HEAD(&hl->hard_links);
4242                 }
4243         }
4244 }
4245
4246 static void yaffs_strip_deleted_objs(struct yaffs_dev *dev)
4247 {
4248         /*
4249          *  Sort out state of unlinked and deleted objects after scanning.
4250          */
4251         struct list_head *i;
4252         struct list_head *n;
4253         struct yaffs_obj *l;
4254
4255         if (dev->read_only)
4256                 return;
4257
4258         /* Soft delete all the unlinked files */
4259         list_for_each_safe(i, n,
4260                            &dev->unlinked_dir->variant.dir_variant.children) {
4261                 l = list_entry(i, struct yaffs_obj, siblings);
4262                 yaffs_del_obj(l);
4263         }
4264
4265         list_for_each_safe(i, n, &dev->del_dir->variant.dir_variant.children) {
4266                 l = list_entry(i, struct yaffs_obj, siblings);
4267                 yaffs_del_obj(l);
4268         }
4269 }
4270
4271 /*
4272  * This code iterates through all the objects making sure that they are rooted.
4273  * Any unrooted objects are re-rooted in lost+found.
4274  * An object needs to be in one of:
4275  * - Directly under deleted, unlinked
4276  * - Directly or indirectly under root.
4277  *
4278  * Note:
4279  *  This code assumes that we don't ever change the current relationships
4280  *  between directories:
4281  *   root_dir->parent == unlinked_dir->parent == del_dir->parent == NULL
4282  *   lost-n-found->parent == root_dir
4283  *
4284  * This fixes the problem where directories might have inadvertently been
4285  * deleted leaving the object "hanging" without being rooted in the
4286  * directory tree.
4287  */
4288
4289 static int yaffs_has_null_parent(struct yaffs_dev *dev, struct yaffs_obj *obj)
4290 {
4291         return (obj == dev->del_dir ||
4292                 obj == dev->unlinked_dir || obj == dev->root_dir);
4293 }
4294
4295 static void yaffs_fix_hanging_objs(struct yaffs_dev *dev)
4296 {
4297         struct yaffs_obj *obj;
4298         struct yaffs_obj *parent;
4299         int i;
4300         struct list_head *lh;
4301         struct list_head *n;
4302         int depth_limit;
4303         int hanging;
4304
4305         if (dev->read_only)
4306                 return;
4307
4308         /* Iterate through the objects in each hash entry,
4309          * looking at each object.
4310          * Make sure it is rooted.
4311          */
4312
4313         for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
4314                 list_for_each_safe(lh, n, &dev->obj_bucket[i].list) {
4315                         obj = list_entry(lh, struct yaffs_obj, hash_link);
4316                         parent = obj->parent;
4317
4318                         if (yaffs_has_null_parent(dev, obj)) {
4319                                 /* These directories are not hanging */
4320                                 hanging = 0;
4321                         } else if (!parent ||
4322                                    parent->variant_type !=
4323                                    YAFFS_OBJECT_TYPE_DIRECTORY) {
4324                                 hanging = 1;
4325                         } else if (yaffs_has_null_parent(dev, parent)) {
4326                                 hanging = 0;
4327                         } else {
4328                                 /*
4329                                  * Need to follow the parent chain to
4330                                  * see if it is hanging.
4331                                  */
4332                                 hanging = 0;
4333                                 depth_limit = 100;
4334
4335                                 while (parent != dev->root_dir &&
4336                                        parent->parent &&
4337                                        parent->parent->variant_type ==
4338                                        YAFFS_OBJECT_TYPE_DIRECTORY &&
4339                                        depth_limit > 0) {
4340                                         parent = parent->parent;
4341                                         depth_limit--;
4342                                 }
4343                                 if (parent != dev->root_dir)
4344                                         hanging = 1;
4345                         }
4346                         if (hanging) {
4347                                 yaffs_trace(YAFFS_TRACE_SCAN,
4348                                         "Hanging object %d moved to lost and found",
4349                                         obj->obj_id);
4350                                 yaffs_add_obj_to_dir(dev->lost_n_found, obj);
4351                         }
4352                 }
4353         }
4354 }
4355
4356 /*
4357  * Delete directory contents for cleaning up lost and found.
4358  */
4359 static void yaffs_del_dir_contents(struct yaffs_obj *dir)
4360 {
4361         struct yaffs_obj *obj;
4362         struct list_head *lh;
4363         struct list_head *n;
4364
4365         if (dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
4366                 BUG();
4367
4368         list_for_each_safe(lh, n, &dir->variant.dir_variant.children) {
4369                 obj = list_entry(lh, struct yaffs_obj, siblings);
4370                 if (obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY)
4371                         yaffs_del_dir_contents(obj);
4372                 yaffs_trace(YAFFS_TRACE_SCAN,
4373                         "Deleting lost_found object %d",
4374                         obj->obj_id);
4375                 yaffs_unlink_obj(obj);
4376         }
4377 }
4378
4379 static void yaffs_empty_l_n_f(struct yaffs_dev *dev)
4380 {
4381         yaffs_del_dir_contents(dev->lost_n_found);
4382 }
4383
4384
4385 struct yaffs_obj *yaffs_find_by_name(struct yaffs_obj *directory,
4386                                      const YCHAR *name)
4387 {
4388         int sum;
4389         struct list_head *i;
4390         YCHAR buffer[YAFFS_MAX_NAME_LENGTH + 1];
4391         struct yaffs_obj *l;
4392
4393         if (!name)
4394                 return NULL;
4395
4396         if (!directory) {
4397                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4398                         "tragedy: yaffs_find_by_name: null pointer directory"
4399                         );
4400                 BUG();
4401                 return NULL;
4402         }
4403         if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4404                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4405                         "tragedy: yaffs_find_by_name: non-directory"
4406                         );
4407                 BUG();
4408         }
4409
4410         sum = yaffs_calc_name_sum(name);
4411
4412         list_for_each(i, &directory->variant.dir_variant.children) {
4413                 l = list_entry(i, struct yaffs_obj, siblings);
4414
4415                 if (l->parent != directory)
4416                         BUG();
4417
4418                 yaffs_check_obj_details_loaded(l);
4419
4420                 /* Special case for lost-n-found */
4421                 if (l->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
4422                         if (!strcmp(name, YAFFS_LOSTNFOUND_NAME))
4423                                 return l;
4424                 } else if (l->sum == sum || l->hdr_chunk <= 0) {
4425                         /* LostnFound chunk called Objxxx
4426                          * Do a real check
4427                          */
4428                         yaffs_get_obj_name(l, buffer,
4429                                 YAFFS_MAX_NAME_LENGTH + 1);
4430                         if (!strncmp(name, buffer, YAFFS_MAX_NAME_LENGTH))
4431                                 return l;
4432                 }
4433         }
4434         return NULL;
4435 }
4436
4437 /* GetEquivalentObject dereferences any hard links to get to the
4438  * actual object.
4439  */
4440
4441 struct yaffs_obj *yaffs_get_equivalent_obj(struct yaffs_obj *obj)
4442 {
4443         if (obj && obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
4444                 obj = obj->variant.hardlink_variant.equiv_obj;
4445                 yaffs_check_obj_details_loaded(obj);
4446         }
4447         return obj;
4448 }
4449
4450 /*
4451  *  A note or two on object names.
4452  *  * If the object name is missing, we then make one up in the form objnnn
4453  *
4454  *  * ASCII names are stored in the object header's name field from byte zero
4455  *  * Unicode names are historically stored starting from byte zero.
4456  *
4457  * Then there are automatic Unicode names...
4458  * The purpose of these is to save names in a way that can be read as
4459  * ASCII or Unicode names as appropriate, thus allowing a Unicode and ASCII
4460  * system to share files.
4461  *
4462  * These automatic unicode are stored slightly differently...
4463  *  - If the name can fit in the ASCII character space then they are saved as
4464  *    ascii names as per above.
4465  *  - If the name needs Unicode then the name is saved in Unicode
4466  *    starting at oh->name[1].
4467
4468  */
4469 static void yaffs_fix_null_name(struct yaffs_obj *obj, YCHAR *name,
4470                                 int buffer_size)
4471 {
4472         /* Create an object name if we could not find one. */
4473         if (strnlen(name, YAFFS_MAX_NAME_LENGTH) == 0) {
4474                 YCHAR local_name[20];
4475                 YCHAR num_string[20];
4476                 YCHAR *x = &num_string[19];
4477                 unsigned v = obj->obj_id;
4478                 num_string[19] = 0;
4479                 while (v > 0) {
4480                         x--;
4481                         *x = '0' + (v % 10);
4482                         v /= 10;
4483                 }
4484                 /* make up a name */
4485                 strcpy(local_name, YAFFS_LOSTNFOUND_PREFIX);
4486                 strcat(local_name, x);
4487                 strncpy(name, local_name, buffer_size - 1);
4488         }
4489 }
4490
4491 int yaffs_get_obj_name(struct yaffs_obj *obj, YCHAR *name, int buffer_size)
4492 {
4493         memset(name, 0, buffer_size * sizeof(YCHAR));
4494         yaffs_check_obj_details_loaded(obj);
4495         if (obj->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
4496                 strncpy(name, YAFFS_LOSTNFOUND_NAME, buffer_size - 1);
4497         } else if (obj->short_name[0]) {
4498                 strcpy(name, obj->short_name);
4499         } else if (obj->hdr_chunk > 0) {
4500                 int result;
4501                 u8 *buffer = yaffs_get_temp_buffer(obj->my_dev);
4502
4503                 struct yaffs_obj_hdr *oh = (struct yaffs_obj_hdr *)buffer;
4504
4505                 memset(buffer, 0, obj->my_dev->data_bytes_per_chunk);
4506
4507                 if (obj->hdr_chunk > 0) {
4508                         result = yaffs_rd_chunk_tags_nand(obj->my_dev,
4509                                                           obj->hdr_chunk,
4510                                                           buffer, NULL);
4511                 }
4512                 yaffs_load_name_from_oh(obj->my_dev, name, oh->name,
4513                                         buffer_size);
4514
4515                 yaffs_release_temp_buffer(obj->my_dev, buffer);
4516         }
4517
4518         yaffs_fix_null_name(obj, name, buffer_size);
4519
4520         return strnlen(name, YAFFS_MAX_NAME_LENGTH);
4521 }
4522
4523 loff_t yaffs_get_obj_length(struct yaffs_obj *obj)
4524 {
4525         /* Dereference any hard linking */
4526         obj = yaffs_get_equivalent_obj(obj);
4527
4528         if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
4529                 return obj->variant.file_variant.file_size;
4530         if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
4531                 if (!obj->variant.symlink_variant.alias)
4532                         return 0;
4533                 return strnlen(obj->variant.symlink_variant.alias,
4534                                      YAFFS_MAX_ALIAS_LENGTH);
4535         } else {
4536                 /* Only a directory should drop through to here */
4537                 return obj->my_dev->data_bytes_per_chunk;
4538         }
4539 }
4540
4541 int yaffs_get_obj_link_count(struct yaffs_obj *obj)
4542 {
4543         int count = 0;
4544         struct list_head *i;
4545
4546         if (!obj->unlinked)
4547                 count++;        /* the object itself */
4548
4549         list_for_each(i, &obj->hard_links)
4550             count++;            /* add the hard links; */
4551
4552         return count;
4553 }
4554
4555 int yaffs_get_obj_inode(struct yaffs_obj *obj)
4556 {
4557         obj = yaffs_get_equivalent_obj(obj);
4558
4559         return obj->obj_id;
4560 }
4561
4562 unsigned yaffs_get_obj_type(struct yaffs_obj *obj)
4563 {
4564         obj = yaffs_get_equivalent_obj(obj);
4565
4566         switch (obj->variant_type) {
4567         case YAFFS_OBJECT_TYPE_FILE:
4568                 return DT_REG;
4569                 break;
4570         case YAFFS_OBJECT_TYPE_DIRECTORY:
4571                 return DT_DIR;
4572                 break;
4573         case YAFFS_OBJECT_TYPE_SYMLINK:
4574                 return DT_LNK;
4575                 break;
4576         case YAFFS_OBJECT_TYPE_HARDLINK:
4577                 return DT_REG;
4578                 break;
4579         case YAFFS_OBJECT_TYPE_SPECIAL:
4580                 if (S_ISFIFO(obj->yst_mode))
4581                         return DT_FIFO;
4582                 if (S_ISCHR(obj->yst_mode))
4583                         return DT_CHR;
4584                 if (S_ISBLK(obj->yst_mode))
4585                         return DT_BLK;
4586                 if (S_ISSOCK(obj->yst_mode))
4587                         return DT_SOCK;
4588                 return DT_REG;
4589                 break;
4590         default:
4591                 return DT_REG;
4592                 break;
4593         }
4594 }
4595
4596 YCHAR *yaffs_get_symlink_alias(struct yaffs_obj *obj)
4597 {
4598         obj = yaffs_get_equivalent_obj(obj);
4599         if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK)
4600                 return yaffs_clone_str(obj->variant.symlink_variant.alias);
4601         else
4602                 return yaffs_clone_str(_Y(""));
4603 }
4604
4605 /*--------------------------- Initialisation code -------------------------- */
4606
4607 static int yaffs_check_dev_fns(struct yaffs_dev *dev)
4608 {
4609         struct yaffs_driver *drv = &dev->drv;
4610         struct yaffs_tags_handler *tagger = &dev->tagger;
4611
4612         /* Common functions, gotta have */
4613         if (!drv->drv_read_chunk_fn ||
4614             !drv->drv_write_chunk_fn ||
4615             !drv->drv_erase_fn)
4616                 return 0;
4617
4618         if (dev->param.is_yaffs2 &&
4619              (!drv->drv_mark_bad_fn  || !drv->drv_check_bad_fn))
4620                 return 0;
4621
4622         /* Install the default tags marshalling functions if needed. */
4623         yaffs_tags_compat_install(dev);
4624         yaffs_tags_marshall_install(dev);
4625
4626         /* Check we now have the marshalling functions required. */
4627         if (!tagger->write_chunk_tags_fn ||
4628             !tagger->read_chunk_tags_fn ||
4629             !tagger->query_block_fn ||
4630             !tagger->mark_bad_fn)
4631                 return 0;
4632
4633         return 1;
4634 }
4635
4636 static int yaffs_create_initial_dir(struct yaffs_dev *dev)
4637 {
4638         /* Initialise the unlinked, deleted, root and lost+found directories */
4639         dev->lost_n_found = dev->root_dir = NULL;
4640         dev->unlinked_dir = dev->del_dir = NULL;
4641         dev->unlinked_dir =
4642             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_UNLINKED, S_IFDIR);
4643         dev->del_dir =
4644             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_DELETED, S_IFDIR);
4645         dev->root_dir =
4646             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_ROOT,
4647                                   YAFFS_ROOT_MODE | S_IFDIR);
4648         dev->lost_n_found =
4649             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_LOSTNFOUND,
4650                                   YAFFS_LOSTNFOUND_MODE | S_IFDIR);
4651
4652         if (dev->lost_n_found && dev->root_dir && dev->unlinked_dir
4653             && dev->del_dir) {
4654                 yaffs_add_obj_to_dir(dev->root_dir, dev->lost_n_found);
4655                 return YAFFS_OK;
4656         }
4657         return YAFFS_FAIL;
4658 }
4659
4660 /* Low level init.
4661  * Typically only used by yaffs_guts_initialise, but also used by the
4662  * Low level yaffs driver tests.
4663  */
4664
4665 int yaffs_guts_ll_init(struct yaffs_dev *dev)
4666 {
4667
4668
4669         yaffs_trace(YAFFS_TRACE_TRACING, "yaffs: yaffs_ll_init()");
4670
4671         if (!dev) {
4672                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4673                         "yaffs: Need a device"
4674                         );
4675                 return YAFFS_FAIL;
4676         }
4677
4678         if (dev->ll_init)
4679                 return YAFFS_OK;
4680
4681         dev->internal_start_block = dev->param.start_block;
4682         dev->internal_end_block = dev->param.end_block;
4683         dev->block_offset = 0;
4684         dev->chunk_offset = 0;
4685         dev->n_free_chunks = 0;
4686
4687         dev->gc_block = 0;
4688
4689         if (dev->param.start_block == 0) {
4690                 dev->internal_start_block = dev->param.start_block + 1;
4691                 dev->internal_end_block = dev->param.end_block + 1;
4692                 dev->block_offset = 1;
4693                 dev->chunk_offset = dev->param.chunks_per_block;
4694         }
4695
4696         /* Check geometry parameters. */
4697
4698         if ((!dev->param.inband_tags && dev->param.is_yaffs2 &&
4699                 dev->param.total_bytes_per_chunk < 1024) ||
4700                 (!dev->param.is_yaffs2 &&
4701                         dev->param.total_bytes_per_chunk < 512) ||
4702                 (dev->param.inband_tags && !dev->param.is_yaffs2) ||
4703                  dev->param.chunks_per_block < 2 ||
4704                  dev->param.n_reserved_blocks < 2 ||
4705                 dev->internal_start_block <= 0 ||
4706                 dev->internal_end_block <= 0 ||
4707                 dev->internal_end_block <=
4708                 (dev->internal_start_block + dev->param.n_reserved_blocks + 2)
4709                 ) {
4710                 /* otherwise it is too small */
4711                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4712                         "NAND geometry problems: chunk size %d, type is yaffs%s, inband_tags %d ",
4713                         dev->param.total_bytes_per_chunk,
4714                         dev->param.is_yaffs2 ? "2" : "",
4715                         dev->param.inband_tags);
4716                 return YAFFS_FAIL;
4717         }
4718
4719         /* Sort out space for inband tags, if required */
4720         if (dev->param.inband_tags)
4721                 dev->data_bytes_per_chunk =
4722                     dev->param.total_bytes_per_chunk -
4723                     sizeof(struct yaffs_packed_tags2_tags_only);
4724         else
4725                 dev->data_bytes_per_chunk = dev->param.total_bytes_per_chunk;
4726
4727         /* Got the right mix of functions? */
4728         if (!yaffs_check_dev_fns(dev)) {
4729                 /* Function missing */
4730                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4731                         "device function(s) missing or wrong");
4732
4733                 return YAFFS_FAIL;
4734         }
4735
4736         if (yaffs_init_nand(dev) != YAFFS_OK) {
4737                 yaffs_trace(YAFFS_TRACE_ALWAYS, "InitialiseNAND failed");
4738                 return YAFFS_FAIL;
4739         }
4740
4741         return YAFFS_OK;
4742 }
4743
4744
4745 int yaffs_format_dev(struct yaffs_dev *dev)
4746 {
4747         int i;
4748         enum yaffs_block_state state;
4749         u32 dummy;
4750
4751         if(yaffs_guts_ll_init(dev) != YAFFS_OK)
4752                 return YAFFS_FAIL;
4753
4754         if(dev->is_mounted)
4755                 return YAFFS_FAIL;
4756
4757         for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
4758                 yaffs_query_init_block_state(dev, i, &state, &dummy);
4759                 if (state != YAFFS_BLOCK_STATE_DEAD)
4760                         yaffs_erase_block(dev, i);
4761         }
4762
4763         return YAFFS_OK;
4764 }
4765
4766
4767 int yaffs_guts_initialise(struct yaffs_dev *dev)
4768 {
4769         int init_failed = 0;
4770         unsigned x;
4771         int bits;
4772
4773         if(yaffs_guts_ll_init(dev) != YAFFS_OK)
4774                 return YAFFS_FAIL;
4775
4776         if (dev->is_mounted) {
4777                 yaffs_trace(YAFFS_TRACE_ALWAYS, "device already mounted");
4778                 return YAFFS_FAIL;
4779         }
4780
4781         dev->is_mounted = 1;
4782
4783         /* OK now calculate a few things for the device */
4784
4785         /*
4786          *  Calculate all the chunk size manipulation numbers:
4787          */
4788         x = dev->data_bytes_per_chunk;
4789         /* We always use dev->chunk_shift and dev->chunk_div */
4790         dev->chunk_shift = calc_shifts(x);
4791         x >>= dev->chunk_shift;
4792         dev->chunk_div = x;
4793         /* We only use chunk mask if chunk_div is 1 */
4794         dev->chunk_mask = (1 << dev->chunk_shift) - 1;
4795
4796         /*
4797          * Calculate chunk_grp_bits.
4798          * We need to find the next power of 2 > than internal_end_block
4799          */
4800
4801         x = dev->param.chunks_per_block * (dev->internal_end_block + 1);
4802
4803         bits = calc_shifts_ceiling(x);
4804
4805         /* Set up tnode width if wide tnodes are enabled. */
4806         if (!dev->param.wide_tnodes_disabled) {
4807                 /* bits must be even so that we end up with 32-bit words */
4808                 if (bits & 1)
4809                         bits++;
4810                 if (bits < 16)
4811                         dev->tnode_width = 16;
4812                 else
4813                         dev->tnode_width = bits;
4814         } else {
4815                 dev->tnode_width = 16;
4816         }
4817
4818         dev->tnode_mask = (1 << dev->tnode_width) - 1;
4819
4820         /* Level0 Tnodes are 16 bits or wider (if wide tnodes are enabled),
4821          * so if the bitwidth of the
4822          * chunk range we're using is greater than 16 we need
4823          * to figure out chunk shift and chunk_grp_size
4824          */
4825
4826         if (bits <= dev->tnode_width)
4827                 dev->chunk_grp_bits = 0;
4828         else
4829                 dev->chunk_grp_bits = bits - dev->tnode_width;
4830
4831         dev->tnode_size = (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8;
4832         if (dev->tnode_size < sizeof(struct yaffs_tnode))
4833                 dev->tnode_size = sizeof(struct yaffs_tnode);
4834
4835         dev->chunk_grp_size = 1 << dev->chunk_grp_bits;
4836
4837         if (dev->param.chunks_per_block < dev->chunk_grp_size) {
4838                 /* We have a problem because the soft delete won't work if
4839                  * the chunk group size > chunks per block.
4840                  * This can be remedied by using larger "virtual blocks".
4841                  */
4842                 yaffs_trace(YAFFS_TRACE_ALWAYS, "chunk group too large");
4843
4844                 return YAFFS_FAIL;
4845         }
4846
4847         /* Finished verifying the device, continue with initialisation */
4848
4849         /* More device initialisation */
4850         dev->all_gcs = 0;
4851         dev->passive_gc_count = 0;
4852         dev->oldest_dirty_gc_count = 0;
4853         dev->bg_gcs = 0;
4854         dev->gc_block_finder = 0;
4855         dev->buffered_block = -1;
4856         dev->doing_buffered_block_rewrite = 0;
4857         dev->n_deleted_files = 0;
4858         dev->n_bg_deletions = 0;
4859         dev->n_unlinked_files = 0;
4860         dev->n_ecc_fixed = 0;
4861         dev->n_ecc_unfixed = 0;
4862         dev->n_tags_ecc_fixed = 0;
4863         dev->n_tags_ecc_unfixed = 0;
4864         dev->n_erase_failures = 0;
4865         dev->n_erased_blocks = 0;
4866         dev->gc_disable = 0;
4867         dev->has_pending_prioritised_gc = 1;
4868                 /* Assume the worst for now, will get fixed on first GC */
4869         INIT_LIST_HEAD(&dev->dirty_dirs);
4870         dev->oldest_dirty_seq = 0;
4871         dev->oldest_dirty_block = 0;
4872
4873         /* Initialise temporary buffers and caches. */
4874         if (!yaffs_init_tmp_buffers(dev))
4875                 init_failed = 1;
4876
4877         dev->cache = NULL;
4878         dev->gc_cleanup_list = NULL;
4879
4880         if (!init_failed && dev->param.n_caches > 0) {
4881                 int i;
4882                 void *buf;
4883                 int cache_bytes =
4884                     dev->param.n_caches * sizeof(struct yaffs_cache);
4885
4886                 if (dev->param.n_caches > YAFFS_MAX_SHORT_OP_CACHES)
4887                         dev->param.n_caches = YAFFS_MAX_SHORT_OP_CACHES;
4888
4889                 dev->cache = kmalloc(cache_bytes, GFP_NOFS);
4890
4891                 buf = (u8 *) dev->cache;
4892
4893                 if (dev->cache)
4894                         memset(dev->cache, 0, cache_bytes);
4895
4896                 for (i = 0; i < dev->param.n_caches && buf; i++) {
4897                         dev->cache[i].object = NULL;
4898                         dev->cache[i].last_use = 0;
4899                         dev->cache[i].dirty = 0;
4900                         dev->cache[i].data = buf =
4901                             kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
4902                 }
4903                 if (!buf)
4904                         init_failed = 1;
4905
4906                 dev->cache_last_use = 0;
4907         }
4908
4909         dev->cache_hits = 0;
4910
4911         if (!init_failed) {
4912                 dev->gc_cleanup_list =
4913                     kmalloc(dev->param.chunks_per_block * sizeof(u32),
4914                                         GFP_NOFS);
4915                 if (!dev->gc_cleanup_list)
4916                         init_failed = 1;
4917         }
4918
4919         if (dev->param.is_yaffs2)
4920                 dev->param.use_header_file_size = 1;
4921
4922         if (!init_failed && !yaffs_init_blocks(dev))
4923                 init_failed = 1;
4924
4925         yaffs_init_tnodes_and_objs(dev);
4926
4927         if (!init_failed && !yaffs_create_initial_dir(dev))
4928                 init_failed = 1;
4929
4930         if (!init_failed && dev->param.is_yaffs2 &&
4931                 !dev->param.disable_summary &&
4932                 !yaffs_summary_init(dev))
4933                 init_failed = 1;
4934
4935         if (!init_failed) {
4936                 /* Now scan the flash. */
4937                 if (dev->param.is_yaffs2) {
4938                         if (yaffs2_checkpt_restore(dev)) {
4939                                 yaffs_check_obj_details_loaded(dev->root_dir);
4940                                 yaffs_trace(YAFFS_TRACE_CHECKPOINT |
4941                                         YAFFS_TRACE_MOUNT,
4942                                         "yaffs: restored from checkpoint"
4943                                         );
4944                         } else {
4945
4946                                 /* Clean up the mess caused by an aborted
4947                                  * checkpoint load then scan backwards.
4948                                  */
4949                                 yaffs_deinit_blocks(dev);
4950
4951                                 yaffs_deinit_tnodes_and_objs(dev);
4952
4953                                 dev->n_erased_blocks = 0;
4954                                 dev->n_free_chunks = 0;
4955                                 dev->alloc_block = -1;
4956                                 dev->alloc_page = -1;
4957                                 dev->n_deleted_files = 0;
4958                                 dev->n_unlinked_files = 0;
4959                                 dev->n_bg_deletions = 0;
4960
4961                                 if (!init_failed && !yaffs_init_blocks(dev))
4962                                         init_failed = 1;
4963
4964                                 yaffs_init_tnodes_and_objs(dev);
4965
4966                                 if (!init_failed
4967                                     && !yaffs_create_initial_dir(dev))
4968                                         init_failed = 1;
4969
4970                                 if (!init_failed && !yaffs2_scan_backwards(dev))
4971                                         init_failed = 1;
4972                         }
4973                 } else if (!yaffs1_scan(dev)) {
4974                         init_failed = 1;
4975                 }
4976
4977                 yaffs_strip_deleted_objs(dev);
4978                 yaffs_fix_hanging_objs(dev);
4979                 if (dev->param.empty_lost_n_found)
4980                         yaffs_empty_l_n_f(dev);
4981         }
4982
4983         if (init_failed) {
4984                 /* Clean up the mess */
4985                 yaffs_trace(YAFFS_TRACE_TRACING,
4986                   "yaffs: yaffs_guts_initialise() aborted.");
4987
4988                 yaffs_deinitialise(dev);
4989                 return YAFFS_FAIL;
4990         }
4991
4992         /* Zero out stats */
4993         dev->n_page_reads = 0;
4994         dev->n_page_writes = 0;
4995         dev->n_erasures = 0;
4996         dev->n_gc_copies = 0;
4997         dev->n_retried_writes = 0;
4998
4999         dev->n_retired_blocks = 0;
5000
5001         yaffs_verify_free_chunks(dev);
5002         yaffs_verify_blocks(dev);
5003
5004         /* Clean up any aborted checkpoint data */
5005         if (!dev->is_checkpointed && dev->blocks_in_checkpt > 0)
5006                 yaffs2_checkpt_invalidate(dev);
5007
5008         yaffs_trace(YAFFS_TRACE_TRACING,
5009           "yaffs: yaffs_guts_initialise() done.");
5010         return YAFFS_OK;
5011 }
5012
5013 void yaffs_deinitialise(struct yaffs_dev *dev)
5014 {
5015         if (dev->is_mounted) {
5016                 int i;
5017
5018                 yaffs_deinit_blocks(dev);
5019                 yaffs_deinit_tnodes_and_objs(dev);
5020                 yaffs_summary_deinit(dev);
5021
5022                 if (dev->param.n_caches > 0 && dev->cache) {
5023
5024                         for (i = 0; i < dev->param.n_caches; i++) {
5025                                 kfree(dev->cache[i].data);
5026                                 dev->cache[i].data = NULL;
5027                         }
5028
5029                         kfree(dev->cache);
5030                         dev->cache = NULL;
5031                 }
5032
5033                 kfree(dev->gc_cleanup_list);
5034
5035                 for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++)
5036                         kfree(dev->temp_buffer[i].buffer);
5037
5038                 dev->is_mounted = 0;
5039
5040                 yaffs_deinit_nand(dev);
5041         }
5042 }
5043
5044 int yaffs_count_free_chunks(struct yaffs_dev *dev)
5045 {
5046         int n_free = 0;
5047         int b;
5048         struct yaffs_block_info *blk;
5049
5050         blk = dev->block_info;
5051         for (b = dev->internal_start_block; b <= dev->internal_end_block; b++) {
5052                 switch (blk->block_state) {
5053                 case YAFFS_BLOCK_STATE_EMPTY:
5054                 case YAFFS_BLOCK_STATE_ALLOCATING:
5055                 case YAFFS_BLOCK_STATE_COLLECTING:
5056                 case YAFFS_BLOCK_STATE_FULL:
5057                         n_free +=
5058                             (dev->param.chunks_per_block - blk->pages_in_use +
5059                              blk->soft_del_pages);
5060                         break;
5061                 default:
5062                         break;
5063                 }
5064                 blk++;
5065         }
5066         return n_free;
5067 }
5068
5069 int yaffs_get_n_free_chunks(struct yaffs_dev *dev)
5070 {
5071         /* This is what we report to the outside world */
5072         int n_free;
5073         int n_dirty_caches;
5074         int blocks_for_checkpt;
5075         int i;
5076
5077         n_free = dev->n_free_chunks;
5078         n_free += dev->n_deleted_files;
5079
5080         /* Now count and subtract the number of dirty chunks in the cache. */
5081
5082         for (n_dirty_caches = 0, i = 0; i < dev->param.n_caches; i++) {
5083                 if (dev->cache[i].dirty)
5084                         n_dirty_caches++;
5085         }
5086
5087         n_free -= n_dirty_caches;
5088
5089         n_free -=
5090             ((dev->param.n_reserved_blocks + 1) * dev->param.chunks_per_block);
5091
5092         /* Now figure checkpoint space and report that... */
5093         blocks_for_checkpt = yaffs_calc_checkpt_blocks_required(dev);
5094
5095         n_free -= (blocks_for_checkpt * dev->param.chunks_per_block);
5096
5097         if (n_free < 0)
5098                 n_free = 0;
5099
5100         return n_free;
5101 }
5102
5103
5104
5105 /*
5106  * Marshalling functions to get loff_t file sizes into and out of
5107  * object headers.
5108  */
5109 void yaffs_oh_size_load(struct yaffs_obj_hdr *oh, loff_t fsize)
5110 {
5111         oh->file_size_low = (fsize & 0xFFFFFFFF);
5112         oh->file_size_high = ((fsize >> 32) & 0xFFFFFFFF);
5113 }
5114
5115 loff_t yaffs_oh_to_size(struct yaffs_obj_hdr *oh)
5116 {
5117         loff_t retval;
5118
5119         if (sizeof(loff_t) >= 8 && ~(oh->file_size_high))
5120                 retval = (((loff_t) oh->file_size_high) << 32) |
5121                         (((loff_t) oh->file_size_low) & 0xFFFFFFFF);
5122         else
5123                 retval = (loff_t) oh->file_size_low;
5124
5125         return retval;
5126 }
5127
5128
5129 void yaffs_count_blocks_by_state(struct yaffs_dev *dev, int bs[10])
5130 {
5131         int i;
5132         struct yaffs_block_info *bi;
5133         int s;
5134
5135         for(i = 0; i < 10; i++)
5136                 bs[i] = 0;
5137
5138         for(i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
5139                 bi = yaffs_get_block_info(dev, i);
5140                 s = bi->block_state;
5141                 if(s > YAFFS_BLOCK_STATE_DEAD || s < YAFFS_BLOCK_STATE_UNKNOWN)
5142                         bs[0]++;
5143                 else
5144                         bs[s]++;
5145         }
5146 }