fs/yaffs2/yaffs_guts.c

   1 /*
   2  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
   3  *
   4  * Copyright (C) 2002-2011 Aleph One Ltd.
   5  *   for Toby Churchill Ltd and Brightstar Engineering
   6  *
   7  * Created by Charles Manning <charles@aleph1.co.uk>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #include "yportenv.h"
  15 #include "yaffs_trace.h"
  16
  17 #include "yaffs_guts.h"
  18 #include "yaffs_getblockinfo.h"
  19 #include "yaffs_tagscompat.h"
  20 #include "yaffs_nand.h"
  21 #include "yaffs_yaffs1.h"
  22 #include "yaffs_yaffs2.h"
  23 #include "yaffs_bitmap.h"
  24 #include "yaffs_verify.h"
  25 #include "yaffs_nand.h"
  26 #include "yaffs_packedtags2.h"
  27 #include "yaffs_nameval.h"
  28 #include "yaffs_allocator.h"
  29 #include "yaffs_attribs.h"
  30 #include "yaffs_summary.h"
  31
  32 /* Note YAFFS_GC_GOOD_ENOUGH must be <= YAFFS_GC_PASSIVE_THRESHOLD */
  33 #define YAFFS_GC_GOOD_ENOUGH 2
  34 #define YAFFS_GC_PASSIVE_THRESHOLD 4
  35
  36 #include "yaffs_ecc.h"
  37
  38 /* Forward declarations */
  39
  40 static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
  41                              const u8 *buffer, int n_bytes, int use_reserve);
  42
  43
  44
  45 /* Function to calculate chunk and offset */
  46
  47 void yaffs_addr_to_chunk(struct yaffs_dev *dev, loff_t addr,
  48                                 int *chunk_out, u32 *offset_out)
  49 {
  50         int chunk;
  51         u32 offset;
  52
  53         chunk = (u32) (addr >> dev->chunk_shift);
  54
  55         if (dev->chunk_div == 1) {
  56                 /* easy power of 2 case */
  57                 offset = (u32) (addr & dev->chunk_mask);
  58         } else {
  59                 /* Non power-of-2 case */
  60
  61                 loff_t chunk_base;
  62
  63                 chunk /= dev->chunk_div;
  64
  65                 chunk_base = ((loff_t) chunk) * dev->data_bytes_per_chunk;
  66                 offset = (u32) (addr - chunk_base);
  67         }
  68
  69         *chunk_out = chunk;
  70         *offset_out = offset;
  71 }
  72
  73 /* Function to return the number of shifts for a power of 2 greater than or
  74  * equal to the given number
  75  * Note we don't try to cater for all possible numbers and this does not have to
  76  * be hellishly efficient.
  77  */
  78
  79 static inline u32 calc_shifts_ceiling(u32 x)
  80 {
  81         int extra_bits;
  82         int shifts;
  83
  84         shifts = extra_bits = 0;
  85
  86         while (x > 1) {
  87                 if (x & 1)
  88                         extra_bits++;
  89                 x >>= 1;
  90                 shifts++;
  91         }
  92
  93         if (extra_bits)
  94                 shifts++;
  95
  96         return shifts;
  97 }
  98
  99 /* Function to return the number of shifts to get a 1 in bit 0
 100  */
 101
 102 static inline u32 calc_shifts(u32 x)
 103 {
 104         u32 shifts;
 105
 106         shifts = 0;
 107
 108         if (!x)
 109                 return 0;
 110
 111         while (!(x & 1)) {
 112                 x >>= 1;
 113                 shifts++;
 114         }
 115
 116         return shifts;
 117 }
 118
 119 /*
 120  * Temporary buffer manipulations.
 121  */
 122
 123 static int yaffs_init_tmp_buffers(struct yaffs_dev *dev)
 124 {
 125         int i;
 126         u8 *buf = (u8 *) 1;
 127
 128         memset(dev->temp_buffer, 0, sizeof(dev->temp_buffer));
 129
 130         for (i = 0; buf && i < YAFFS_N_TEMP_BUFFERS; i++) {
 131                 dev->temp_buffer[i].in_use = 0;
 132                 buf = kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
 133                 dev->temp_buffer[i].buffer = buf;
 134         }
 135
 136         return buf ? YAFFS_OK : YAFFS_FAIL;
 137 }
 138
 139 u8 *yaffs_get_temp_buffer(struct yaffs_dev * dev)
 140 {
 141         int i;
 142
 143         dev->temp_in_use++;
 144         if (dev->temp_in_use > dev->max_temp)
 145                 dev->max_temp = dev->temp_in_use;
 146
 147         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
 148                 if (dev->temp_buffer[i].in_use == 0) {
 149                         dev->temp_buffer[i].in_use = 1;
 150                         return dev->temp_buffer[i].buffer;
 151                 }
 152         }
 153
 154         yaffs_trace(YAFFS_TRACE_BUFFERS, "Out of temp buffers");
 155         /*
 156          * If we got here then we have to allocate an unmanaged one
 157          * This is not good.
 158          */
 159
 160         dev->unmanaged_buffer_allocs++;
 161         return kmalloc(dev->data_bytes_per_chunk, GFP_NOFS);
 162
 163 }
 164
 165 void yaffs_release_temp_buffer(struct yaffs_dev *dev, u8 *buffer)
 166 {
 167         int i;
 168
 169         dev->temp_in_use--;
 170
 171         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
 172                 if (dev->temp_buffer[i].buffer == buffer) {
 173                         dev->temp_buffer[i].in_use = 0;
 174                         return;
 175                 }
 176         }
 177
 178         if (buffer) {
 179                 /* assume it is an unmanaged one. */
 180                 yaffs_trace(YAFFS_TRACE_BUFFERS,
 181                         "Releasing unmanaged temp buffer");
 182                 kfree(buffer);
 183                 dev->unmanaged_buffer_deallocs++;
 184         }
 185
 186 }
 187
 188 /*
 189  * Determine if we have a managed buffer.
 190  */
 191 int yaffs_is_managed_tmp_buffer(struct yaffs_dev *dev, const u8 *buffer)
 192 {
 193         int i;
 194
 195         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
 196                 if (dev->temp_buffer[i].buffer == buffer)
 197                         return 1;
 198         }
 199
 200         for (i = 0; i < dev->param.n_caches; i++) {
 201                 if (dev->cache[i].data == buffer)
 202                         return 1;
 203         }
 204
 205         if (buffer == dev->checkpt_buffer)
 206                 return 1;
 207
 208         yaffs_trace(YAFFS_TRACE_ALWAYS,
 209           "yaffs: unmaged buffer detected.");
 210         return 0;
 211 }
 212
 213 /*
 214  * Functions for robustisizing TODO
 215  *
 216  */
 217
 218 static void yaffs_handle_chunk_wr_ok(struct yaffs_dev *dev, int nand_chunk,
 219                                      const u8 *data,
 220                                      const struct yaffs_ext_tags *tags)
 221 {
 222 }
 223
 224 static void yaffs_handle_chunk_update(struct yaffs_dev *dev, int nand_chunk,
 225                                       const struct yaffs_ext_tags *tags)
 226 {
 227 }
 228
 229 void yaffs_handle_chunk_error(struct yaffs_dev *dev,
 230                               struct yaffs_block_info *bi)
 231 {
 232         if (!bi->gc_prioritise) {
 233                 bi->gc_prioritise = 1;
 234                 dev->has_pending_prioritised_gc = 1;
 235                 bi->chunk_error_strikes++;
 236
 237                 if (bi->chunk_error_strikes > 3) {
 238                         bi->needs_retiring = 1; /* Too many stikes, so retire */
 239                         yaffs_trace(YAFFS_TRACE_ALWAYS,
 240                                 "yaffs: Block struck out");
 241
 242                 }
 243         }
 244 }
 245
 246 static void yaffs_handle_chunk_wr_error(struct yaffs_dev *dev, int nand_chunk,
 247                                         int erased_ok)
 248 {
 249         int flash_block = nand_chunk / dev->param.chunks_per_block;
 250         struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
 251
 252         yaffs_handle_chunk_error(dev, bi);
 253
 254         if (erased_ok) {
 255                 /* Was an actual write failure,
 256                  * so mark the block for retirement.*/
 257                 bi->needs_retiring = 1;
 258                 yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
 259                   "**>> Block %d needs retiring", flash_block);
 260         }
 261
 262         /* Delete the chunk */
 263         yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
 264         yaffs_skip_rest_of_block(dev);
 265 }
 266
 267 /*
 268  * Verification code
 269  */
 270
 271 /*
 272  *  Simple hash function. Needs to have a reasonable spread
 273  */
 274
 275 static inline int yaffs_hash_fn(int n)
 276 {
 277         if (n < 0)
 278                 n = -n;
 279         return n % YAFFS_NOBJECT_BUCKETS;
 280 }
 281
 282 /*
 283  * Access functions to useful fake objects.
 284  * Note that root might have a presence in NAND if permissions are set.
 285  */
 286
 287 struct yaffs_obj *yaffs_root(struct yaffs_dev *dev)
 288 {
 289         return dev->root_dir;
 290 }
 291
 292 struct yaffs_obj *yaffs_lost_n_found(struct yaffs_dev *dev)
 293 {
 294         return dev->lost_n_found;
 295 }
 296
 297 /*
 298  *  Erased NAND checking functions
 299  */
 300
 301 int yaffs_check_ff(u8 *buffer, int n_bytes)
 302 {
 303         /* Horrible, slow implementation */
 304         while (n_bytes--) {
 305                 if (*buffer != 0xff)
 306                         return 0;
 307                 buffer++;
 308         }
 309         return 1;
 310 }
 311
 312 static int yaffs_check_chunk_erased(struct yaffs_dev *dev, int nand_chunk)
 313 {
 314         int retval = YAFFS_OK;
 315         u8 *data = yaffs_get_temp_buffer(dev);
 316         struct yaffs_ext_tags tags;
 317
 318         yaffs_rd_chunk_tags_nand(dev, nand_chunk, data, &tags);
 319
 320         if (tags.ecc_result > YAFFS_ECC_RESULT_NO_ERROR)
 321                 retval = YAFFS_FAIL;
 322
 323         if (!yaffs_check_ff(data, dev->data_bytes_per_chunk) ||
 324                 tags.chunk_used) {
 325                 yaffs_trace(YAFFS_TRACE_NANDACCESS,
 326                         "Chunk %d not erased", nand_chunk);
 327                 retval = YAFFS_FAIL;
 328         }
 329
 330         yaffs_release_temp_buffer(dev, data);
 331
 332         return retval;
 333
 334 }
 335
 336 static int yaffs_verify_chunk_written(struct yaffs_dev *dev,
 337                                       int nand_chunk,
 338                                       const u8 *data,
 339                                       struct yaffs_ext_tags *tags)
 340 {
 341         int retval = YAFFS_OK;
 342         struct yaffs_ext_tags temp_tags;
 343         u8 *buffer = yaffs_get_temp_buffer(dev);
 344
 345         yaffs_rd_chunk_tags_nand(dev, nand_chunk, buffer, &temp_tags);
 346         if (memcmp(buffer, data, dev->data_bytes_per_chunk) ||
 347             temp_tags.obj_id != tags->obj_id ||
 348             temp_tags.chunk_id != tags->chunk_id ||
 349             temp_tags.n_bytes != tags->n_bytes)
 350                 retval = YAFFS_FAIL;
 351
 352         yaffs_release_temp_buffer(dev, buffer);
 353
 354         return retval;
 355 }
 356
 357
 358 int yaffs_check_alloc_available(struct yaffs_dev *dev, int n_chunks)
 359 {
 360         int reserved_chunks;
 361         int reserved_blocks = dev->param.n_reserved_blocks;
 362         int checkpt_blocks;
 363
 364         checkpt_blocks = yaffs_calc_checkpt_blocks_required(dev);
 365
 366         reserved_chunks =
 367             (reserved_blocks + checkpt_blocks) * dev->param.chunks_per_block;
 368
 369         return (dev->n_free_chunks > (reserved_chunks + n_chunks));
 370 }
 371
 372 static int yaffs_find_alloc_block(struct yaffs_dev *dev)
 373 {
 374         int i;
 375         struct yaffs_block_info *bi;
 376
 377         if (dev->n_erased_blocks < 1) {
 378                 /* Hoosterman we've got a problem.
 379                  * Can't get space to gc
 380                  */
 381                 yaffs_trace(YAFFS_TRACE_ERROR,
 382                   "yaffs tragedy: no more erased blocks");
 383
 384                 return -1;
 385         }
 386
 387         /* Find an empty block. */
 388
 389         for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
 390                 dev->alloc_block_finder++;
 391                 if (dev->alloc_block_finder < dev->internal_start_block
 392                     || dev->alloc_block_finder > dev->internal_end_block) {
 393                         dev->alloc_block_finder = dev->internal_start_block;
 394                 }
 395
 396                 bi = yaffs_get_block_info(dev, dev->alloc_block_finder);
 397
 398                 if (bi->block_state == YAFFS_BLOCK_STATE_EMPTY) {
 399                         bi->block_state = YAFFS_BLOCK_STATE_ALLOCATING;
 400                         dev->seq_number++;
 401                         bi->seq_number = dev->seq_number;
 402                         dev->n_erased_blocks--;
 403                         yaffs_trace(YAFFS_TRACE_ALLOCATE,
 404                           "Allocated block %d, seq  %d, %d left" ,
 405                            dev->alloc_block_finder, dev->seq_number,
 406                            dev->n_erased_blocks);
 407                         return dev->alloc_block_finder;
 408                 }
 409         }
 410
 411         yaffs_trace(YAFFS_TRACE_ALWAYS,
 412                 "yaffs tragedy: no more erased blocks, but there should have been %d",
 413                 dev->n_erased_blocks);
 414
 415         return -1;
 416 }
 417
 418 static int yaffs_alloc_chunk(struct yaffs_dev *dev, int use_reserver,
 419                              struct yaffs_block_info **block_ptr)
 420 {
 421         int ret_val;
 422         struct yaffs_block_info *bi;
 423
 424         if (dev->alloc_block < 0) {
 425                 /* Get next block to allocate off */
 426                 dev->alloc_block = yaffs_find_alloc_block(dev);
 427                 dev->alloc_page = 0;
 428         }
 429
 430         if (!use_reserver && !yaffs_check_alloc_available(dev, 1)) {
 431                 /* No space unless we're allowed to use the reserve. */
 432                 return -1;
 433         }
 434
 435         if (dev->n_erased_blocks < dev->param.n_reserved_blocks
 436             && dev->alloc_page == 0)
 437                 yaffs_trace(YAFFS_TRACE_ALLOCATE, "Allocating reserve");
 438
 439         /* Next page please.... */
 440         if (dev->alloc_block >= 0) {
 441                 bi = yaffs_get_block_info(dev, dev->alloc_block);
 442
 443                 ret_val = (dev->alloc_block * dev->param.chunks_per_block) +
 444                     dev->alloc_page;
 445                 bi->pages_in_use++;
 446                 yaffs_set_chunk_bit(dev, dev->alloc_block, dev->alloc_page);
 447
 448                 dev->alloc_page++;
 449
 450                 dev->n_free_chunks--;
 451
 452                 /* If the block is full set the state to full */
 453                 if (dev->alloc_page >= dev->param.chunks_per_block) {
 454                         bi->block_state = YAFFS_BLOCK_STATE_FULL;
 455                         dev->alloc_block = -1;
 456                 }
 457
 458                 if (block_ptr)
 459                         *block_ptr = bi;
 460
 461                 return ret_val;
 462         }
 463
 464         yaffs_trace(YAFFS_TRACE_ERROR,
 465                 "!!!!!!!!! Allocator out !!!!!!!!!!!!!!!!!");
 466
 467         return -1;
 468 }
 469
 470 static int yaffs_get_erased_chunks(struct yaffs_dev *dev)
 471 {
 472         int n;
 473
 474         n = dev->n_erased_blocks * dev->param.chunks_per_block;
 475
 476         if (dev->alloc_block > 0)
 477                 n += (dev->param.chunks_per_block - dev->alloc_page);
 478
 479         return n;
 480
 481 }
 482
 483 /*
 484  * yaffs_skip_rest_of_block() skips over the rest of the allocation block
 485  * if we don't want to write to it.
 486  */
 487 void yaffs_skip_rest_of_block(struct yaffs_dev *dev)
 488 {
 489         struct yaffs_block_info *bi;
 490
 491         if (dev->alloc_block > 0) {
 492                 bi = yaffs_get_block_info(dev, dev->alloc_block);
 493                 if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING) {
 494                         bi->block_state = YAFFS_BLOCK_STATE_FULL;
 495                         dev->alloc_block = -1;
 496                 }
 497         }
 498 }
 499
 500 static int yaffs_write_new_chunk(struct yaffs_dev *dev,
 501                                  const u8 *data,
 502                                  struct yaffs_ext_tags *tags, int use_reserver)
 503 {
 504         int attempts = 0;
 505         int write_ok = 0;
 506         int chunk;
 507
 508         yaffs2_checkpt_invalidate(dev);
 509
 510         do {
 511                 struct yaffs_block_info *bi = 0;
 512                 int erased_ok = 0;
 513
 514                 chunk = yaffs_alloc_chunk(dev, use_reserver, &bi);
 515                 if (chunk < 0) {
 516                         /* no space */
 517                         break;
 518                 }
 519
 520                 /* First check this chunk is erased, if it needs
 521                  * checking.  The checking policy (unless forced
 522                  * always on) is as follows:
 523                  *
 524                  * Check the first page we try to write in a block.
 525                  * If the check passes then we don't need to check any
 526                  * more.        If the check fails, we check again...
 527                  * If the block has been erased, we don't need to check.
 528                  *
 529                  * However, if the block has been prioritised for gc,
 530                  * then we think there might be something odd about
 531                  * this block and stop using it.
 532                  *
 533                  * Rationale: We should only ever see chunks that have
 534                  * not been erased if there was a partially written
 535                  * chunk due to power loss.  This checking policy should
 536                  * catch that case with very few checks and thus save a
 537                  * lot of checks that are most likely not needed.
 538                  *
 539                  * Mods to the above
 540                  * If an erase check fails or the write fails we skip the
 541                  * rest of the block.
 542                  */
 543
 544                 /* let's give it a try */
 545                 attempts++;
 546
 547                 if (dev->param.always_check_erased)
 548                         bi->skip_erased_check = 0;
 549
 550                 if (!bi->skip_erased_check) {
 551                         erased_ok = yaffs_check_chunk_erased(dev, chunk);
 552                         if (erased_ok != YAFFS_OK) {
 553                                 yaffs_trace(YAFFS_TRACE_ERROR,
 554                                   "**>> yaffs chunk %d was not erased",
 555                                   chunk);
 556
 557                                 /* If not erased, delete this one,
 558                                  * skip rest of block and
 559                                  * try another chunk */
 560                                 yaffs_chunk_del(dev, chunk, 1, __LINE__);
 561                                 yaffs_skip_rest_of_block(dev);
 562                                 continue;
 563                         }
 564                 }
 565
 566                 write_ok = yaffs_wr_chunk_tags_nand(dev, chunk, data, tags);
 567
 568                 if (!bi->skip_erased_check)
 569                         write_ok =
 570                             yaffs_verify_chunk_written(dev, chunk, data, tags);
 571
 572                 if (write_ok != YAFFS_OK) {
 573                         /* Clean up aborted write, skip to next block and
 574                          * try another chunk */
 575                         yaffs_handle_chunk_wr_error(dev, chunk, erased_ok);
 576                         continue;
 577                 }
 578
 579                 bi->skip_erased_check = 1;
 580
 581                 /* Copy the data into the robustification buffer */
 582                 yaffs_handle_chunk_wr_ok(dev, chunk, data, tags);
 583
 584         } while (write_ok != YAFFS_OK &&
 585                  (yaffs_wr_attempts <= 0 || attempts <= yaffs_wr_attempts));
 586
 587         if (!write_ok)
 588                 chunk = -1;
 589
 590         if (attempts > 1) {
 591                 yaffs_trace(YAFFS_TRACE_ERROR,
 592                         "**>> yaffs write required %d attempts",
 593                         attempts);
 594                 dev->n_retried_writes += (attempts - 1);
 595         }
 596
 597         return chunk;
 598 }
 599
 600 /*
 601  * Block retiring for handling a broken block.
 602  */
 603
 604 static void yaffs_retire_block(struct yaffs_dev *dev, int flash_block)
 605 {
 606         struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
 607
 608         yaffs2_checkpt_invalidate(dev);
 609
 610         yaffs2_clear_oldest_dirty_seq(dev, bi);
 611
 612         if (yaffs_mark_bad(dev, flash_block) != YAFFS_OK) {
 613                 if (yaffs_erase_block(dev, flash_block) != YAFFS_OK) {
 614                         yaffs_trace(YAFFS_TRACE_ALWAYS,
 615                                 "yaffs: Failed to mark bad and erase block %d",
 616                                 flash_block);
 617                 } else {
 618                         struct yaffs_ext_tags tags;
 619                         int chunk_id =
 620                             flash_block * dev->param.chunks_per_block;
 621
 622                         u8 *buffer = yaffs_get_temp_buffer(dev);
 623
 624                         memset(buffer, 0xff, dev->data_bytes_per_chunk);
 625                         memset(&tags, 0, sizeof(tags));
 626                         tags.seq_number = YAFFS_SEQUENCE_BAD_BLOCK;
 627                         if (dev->param.write_chunk_tags_fn(dev, chunk_id -
 628                                                            dev->chunk_offset,
 629                                                            buffer,
 630                                                            &tags) != YAFFS_OK)
 631                                 yaffs_trace(YAFFS_TRACE_ALWAYS,
 632                                         "yaffs: Failed to write bad block marker to block %d",
 633                                         flash_block);
 634
 635                         yaffs_release_temp_buffer(dev, buffer);
 636                 }
 637         }
 638
 639         bi->block_state = YAFFS_BLOCK_STATE_DEAD;
 640         bi->gc_prioritise = 0;
 641         bi->needs_retiring = 0;
 642
 643         dev->n_retired_blocks++;
 644 }
 645
 646 /*---------------- Name handling functions ------------*/
 647
 648 static u16 yaffs_calc_name_sum(const YCHAR *name)
 649 {
 650         u16 sum = 0;
 651         u16 i = 1;
 652
 653         if (!name)
 654                 return 0;
 655
 656         while ((*name) && i < (YAFFS_MAX_NAME_LENGTH / 2)) {
 657
 658                 /* 0x1f mask is case insensitive */
 659                 sum += ((*name) & 0x1f) * i;
 660                 i++;
 661                 name++;
 662         }
 663         return sum;
 664 }
 665
 666 void yaffs_set_obj_name(struct yaffs_obj *obj, const YCHAR * name)
 667 {
 668         memset(obj->short_name, 0, sizeof(obj->short_name));
 669         if (name &&
 670                 yaffs_strnlen(name, YAFFS_SHORT_NAME_LENGTH + 1) <=
 671                 YAFFS_SHORT_NAME_LENGTH)
 672                 yaffs_strcpy(obj->short_name, name);
 673         else
 674                 obj->short_name[0] = _Y('\0');
 675         obj->sum = yaffs_calc_name_sum(name);
 676 }
 677
 678 void yaffs_set_obj_name_from_oh(struct yaffs_obj *obj,
 679                                 const struct yaffs_obj_hdr *oh)
 680 {
 681 #ifdef CONFIG_YAFFS_AUTO_UNICODE
 682         YCHAR tmp_name[YAFFS_MAX_NAME_LENGTH + 1];
 683         memset(tmp_name, 0, sizeof(tmp_name));
 684         yaffs_load_name_from_oh(obj->my_dev, tmp_name, oh->name,
 685                                 YAFFS_MAX_NAME_LENGTH + 1);
 686         yaffs_set_obj_name(obj, tmp_name);
 687 #else
 688         yaffs_set_obj_name(obj, oh->name);
 689 #endif
 690 }
 691
 692 loff_t yaffs_max_file_size(struct yaffs_dev *dev)
 693 {
 694         return ((loff_t) YAFFS_MAX_CHUNK_ID) * dev->data_bytes_per_chunk;
 695 }
 696
 697 /*-------------------- TNODES -------------------
 698
 699  * List of spare tnodes
 700  * The list is hooked together using the first pointer
 701  * in the tnode.
 702  */
 703
 704 struct yaffs_tnode *yaffs_get_tnode(struct yaffs_dev *dev)
 705 {
 706         struct yaffs_tnode *tn = yaffs_alloc_raw_tnode(dev);
 707
 708         if (tn) {
 709                 memset(tn, 0, dev->tnode_size);
 710                 dev->n_tnodes++;
 711         }
 712
 713         dev->checkpoint_blocks_required = 0;    /* force recalculation */
 714
 715         return tn;
 716 }
 717
 718 /* FreeTnode frees up a tnode and puts it back on the free list */
 719 static void yaffs_free_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
 720 {
 721         yaffs_free_raw_tnode(dev, tn);
 722         dev->n_tnodes--;
 723         dev->checkpoint_blocks_required = 0;    /* force recalculation */
 724 }
 725
 726 static void yaffs_deinit_tnodes_and_objs(struct yaffs_dev *dev)
 727 {
 728         yaffs_deinit_raw_tnodes_and_objs(dev);
 729         dev->n_obj = 0;
 730         dev->n_tnodes = 0;
 731 }
 732
 733 void yaffs_load_tnode_0(struct yaffs_dev *dev, struct yaffs_tnode *tn,
 734                         unsigned pos, unsigned val)
 735 {
 736         u32 *map = (u32 *) tn;
 737         u32 bit_in_map;
 738         u32 bit_in_word;
 739         u32 word_in_map;
 740         u32 mask;
 741
 742         pos &= YAFFS_TNODES_LEVEL0_MASK;
 743         val >>= dev->chunk_grp_bits;
 744
 745         bit_in_map = pos * dev->tnode_width;
 746         word_in_map = bit_in_map / 32;
 747         bit_in_word = bit_in_map & (32 - 1);
 748
 749         mask = dev->tnode_mask << bit_in_word;
 750
 751         map[word_in_map] &= ~mask;
 752         map[word_in_map] |= (mask & (val << bit_in_word));
 753
 754         if (dev->tnode_width > (32 - bit_in_word)) {
 755                 bit_in_word = (32 - bit_in_word);
 756                 word_in_map++;
 757                 mask =
 758                     dev->tnode_mask >> bit_in_word;
 759                 map[word_in_map] &= ~mask;
 760                 map[word_in_map] |= (mask & (val >> bit_in_word));
 761         }
 762 }
 763
 764 u32 yaffs_get_group_base(struct yaffs_dev *dev, struct yaffs_tnode *tn,
 765                          unsigned pos)
 766 {
 767         u32 *map = (u32 *) tn;
 768         u32 bit_in_map;
 769         u32 bit_in_word;
 770         u32 word_in_map;
 771         u32 val;
 772
 773         pos &= YAFFS_TNODES_LEVEL0_MASK;
 774
 775         bit_in_map = pos * dev->tnode_width;
 776         word_in_map = bit_in_map / 32;
 777         bit_in_word = bit_in_map & (32 - 1);
 778
 779         val = map[word_in_map] >> bit_in_word;
 780
 781         if (dev->tnode_width > (32 - bit_in_word)) {
 782                 bit_in_word = (32 - bit_in_word);
 783                 word_in_map++;
 784                 val |= (map[word_in_map] << bit_in_word);
 785         }
 786
 787         val &= dev->tnode_mask;
 788         val <<= dev->chunk_grp_bits;
 789
 790         return val;
 791 }
 792
 793 /* ------------------- End of individual tnode manipulation -----------------*/
 794
 795 /* ---------Functions to manipulate the look-up tree (made up of tnodes) ------
 796  * The look up tree is represented by the top tnode and the number of top_level
 797  * in the tree. 0 means only the level 0 tnode is in the tree.
 798  */
 799
 800 /* FindLevel0Tnode finds the level 0 tnode, if one exists. */
 801 struct yaffs_tnode *yaffs_find_tnode_0(struct yaffs_dev *dev,
 802                                        struct yaffs_file_var *file_struct,
 803                                        u32 chunk_id)
 804 {
 805         struct yaffs_tnode *tn = file_struct->top;
 806         u32 i;
 807         int required_depth;
 808         int level = file_struct->top_level;
 809
 810         /* Check sane level and chunk Id */
 811         if (level < 0 || level > YAFFS_TNODES_MAX_LEVEL)
 812                 return NULL;
 813
 814         if (chunk_id > YAFFS_MAX_CHUNK_ID)
 815                 return NULL;
 816
 817         /* First check we're tall enough (ie enough top_level) */
 818
 819         i = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
 820         required_depth = 0;
 821         while (i) {
 822                 i >>= YAFFS_TNODES_INTERNAL_BITS;
 823                 required_depth++;
 824         }
 825
 826         if (required_depth > file_struct->top_level)
 827                 return NULL;    /* Not tall enough, so we can't find it */
 828
 829         /* Traverse down to level 0 */
 830         while (level > 0 && tn) {
 831                 tn = tn->internal[(chunk_id >>
 832                                    (YAFFS_TNODES_LEVEL0_BITS +
 833                                     (level - 1) *
 834                                     YAFFS_TNODES_INTERNAL_BITS)) &
 835                                   YAFFS_TNODES_INTERNAL_MASK];
 836                 level--;
 837         }
 838
 839         return tn;
 840 }
 841
 842 /* add_find_tnode_0 finds the level 0 tnode if it exists,
 843  * otherwise first expands the tree.
 844  * This happens in two steps:
 845  *  1. If the tree isn't tall enough, then make it taller.
 846  *  2. Scan down the tree towards the level 0 tnode adding tnodes if required.
 847  *
 848  * Used when modifying the tree.
 849  *
 850  *  If the tn argument is NULL, then a fresh tnode will be added otherwise the
 851  *  specified tn will be plugged into the ttree.
 852  */
 853
 854 struct yaffs_tnode *yaffs_add_find_tnode_0(struct yaffs_dev *dev,
 855                                            struct yaffs_file_var *file_struct,
 856                                            u32 chunk_id,
 857                                            struct yaffs_tnode *passed_tn)
 858 {
 859         int required_depth;
 860         int i;
 861         int l;
 862         struct yaffs_tnode *tn;
 863         u32 x;
 864
 865         /* Check sane level and page Id */
 866         if (file_struct->top_level < 0 ||
 867             file_struct->top_level > YAFFS_TNODES_MAX_LEVEL)
 868                 return NULL;
 869
 870         if (chunk_id > YAFFS_MAX_CHUNK_ID)
 871                 return NULL;
 872
 873         /* First check we're tall enough (ie enough top_level) */
 874
 875         x = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
 876         required_depth = 0;
 877         while (x) {
 878                 x >>= YAFFS_TNODES_INTERNAL_BITS;
 879                 required_depth++;
 880         }
 881
 882         if (required_depth > file_struct->top_level) {
 883                 /* Not tall enough, gotta make the tree taller */
 884                 for (i = file_struct->top_level; i < required_depth; i++) {
 885
 886                         tn = yaffs_get_tnode(dev);
 887
 888                         if (tn) {
 889                                 tn->internal[0] = file_struct->top;
 890                                 file_struct->top = tn;
 891                                 file_struct->top_level++;
 892                         } else {
 893                                 yaffs_trace(YAFFS_TRACE_ERROR,
 894                                         "yaffs: no more tnodes");
 895                                 return NULL;
 896                         }
 897                 }
 898         }
 899
 900         /* Traverse down to level 0, adding anything we need */
 901
 902         l = file_struct->top_level;
 903         tn = file_struct->top;
 904
 905         if (l > 0) {
 906                 while (l > 0 && tn) {
 907                         x = (chunk_id >>
 908                              (YAFFS_TNODES_LEVEL0_BITS +
 909                               (l - 1) * YAFFS_TNODES_INTERNAL_BITS)) &
 910                             YAFFS_TNODES_INTERNAL_MASK;
 911
 912                         if ((l > 1) && !tn->internal[x]) {
 913                                 /* Add missing non-level-zero tnode */
 914                                 tn->internal[x] = yaffs_get_tnode(dev);
 915                                 if (!tn->internal[x])
 916                                         return NULL;
 917                         } else if (l == 1) {
 918                                 /* Looking from level 1 at level 0 */
 919                                 if (passed_tn) {
 920                                         /* If we already have one, release it */
 921                                         if (tn->internal[x])
 922                                                 yaffs_free_tnode(dev,
 923                                                         tn->internal[x]);
 924                                         tn->internal[x] = passed_tn;
 925
 926                                 } else if (!tn->internal[x]) {
 927                                         /* Don't have one, none passed in */
 928                                         tn->internal[x] = yaffs_get_tnode(dev);
 929                                         if (!tn->internal[x])
 930                                                 return NULL;
 931                                 }
 932                         }
 933
 934                         tn = tn->internal[x];
 935                         l--;
 936                 }
 937         } else {
 938                 /* top is level 0 */
 939                 if (passed_tn) {
 940                         memcpy(tn, passed_tn,
 941                                (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8);
 942                         yaffs_free_tnode(dev, passed_tn);
 943                 }
 944         }
 945
 946         return tn;
 947 }
 948
 949 static int yaffs_tags_match(const struct yaffs_ext_tags *tags, int obj_id,
 950                             int chunk_obj)
 951 {
 952         return (tags->chunk_id == chunk_obj &&
 953                 tags->obj_id == obj_id &&
 954                 !tags->is_deleted) ? 1 : 0;
 955
 956 }
 957
 958 static int yaffs_find_chunk_in_group(struct yaffs_dev *dev, int the_chunk,
 959                                         struct yaffs_ext_tags *tags, int obj_id,
 960                                         int inode_chunk)
 961 {
 962         int j;
 963
 964         for (j = 0; the_chunk && j < dev->chunk_grp_size; j++) {
 965                 if (yaffs_check_chunk_bit
 966                     (dev, the_chunk / dev->param.chunks_per_block,
 967                      the_chunk % dev->param.chunks_per_block)) {
 968
 969                         if (dev->chunk_grp_size == 1)
 970                                 return the_chunk;
 971                         else {
 972                                 yaffs_rd_chunk_tags_nand(dev, the_chunk, NULL,
 973                                                          tags);
 974                                 if (yaffs_tags_match(tags,
 975                                                         obj_id, inode_chunk)) {
 976                                         /* found it; */
 977                                         return the_chunk;
 978                                 }
 979                         }
 980                 }
 981                 the_chunk++;
 982         }
 983         return -1;
 984 }
 985
 986 static int yaffs_find_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
 987                                     struct yaffs_ext_tags *tags)
 988 {
 989         /*Get the Tnode, then get the level 0 offset chunk offset */
 990         struct yaffs_tnode *tn;
 991         int the_chunk = -1;
 992         struct yaffs_ext_tags local_tags;
 993         int ret_val = -1;
 994         struct yaffs_dev *dev = in->my_dev;
 995
 996         if (!tags) {
 997                 /* Passed a NULL, so use our own tags space */
 998                 tags = &local_tags;
 999         }
1000
1001         tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
1002
1003         if (!tn)
1004                 return ret_val;
1005
1006         the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
1007
1008         ret_val = yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
1009                                               inode_chunk);
1010         return ret_val;
1011 }
1012
1013 static int yaffs_find_del_file_chunk(struct yaffs_obj *in, int inode_chunk,
1014                                      struct yaffs_ext_tags *tags)
1015 {
1016         /* Get the Tnode, then get the level 0 offset chunk offset */
1017         struct yaffs_tnode *tn;
1018         int the_chunk = -1;
1019         struct yaffs_ext_tags local_tags;
1020         struct yaffs_dev *dev = in->my_dev;
1021         int ret_val = -1;
1022
1023         if (!tags) {
1024                 /* Passed a NULL, so use our own tags space */
1025                 tags = &local_tags;
1026         }
1027
1028         tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
1029
1030         if (!tn)
1031                 return ret_val;
1032
1033         the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
1034
1035         ret_val = yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
1036                                               inode_chunk);
1037
1038         /* Delete the entry in the filestructure (if found) */
1039         if (ret_val != -1)
1040                 yaffs_load_tnode_0(dev, tn, inode_chunk, 0);
1041
1042         return ret_val;
1043 }
1044
1045 int yaffs_put_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
1046                             int nand_chunk, int in_scan)
1047 {
1048         /* NB in_scan is zero unless scanning.
1049          * For forward scanning, in_scan is > 0;
1050          * for backward scanning in_scan is < 0
1051          *
1052          * nand_chunk = 0 is a dummy insert to make sure the tnodes are there.
1053          */
1054
1055         struct yaffs_tnode *tn;
1056         struct yaffs_dev *dev = in->my_dev;
1057         int existing_cunk;
1058         struct yaffs_ext_tags existing_tags;
1059         struct yaffs_ext_tags new_tags;
1060         unsigned existing_serial, new_serial;
1061
1062         if (in->variant_type != YAFFS_OBJECT_TYPE_FILE) {
1063                 /* Just ignore an attempt at putting a chunk into a non-file
1064                  * during scanning.
1065                  * If it is not during Scanning then something went wrong!
1066                  */
1067                 if (!in_scan) {
1068                         yaffs_trace(YAFFS_TRACE_ERROR,
1069                                 "yaffs tragedy:attempt to put data chunk into a non-file"
1070                                 );
1071                         BUG();
1072                 }
1073
1074                 yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
1075                 return YAFFS_OK;
1076         }
1077
1078         tn = yaffs_add_find_tnode_0(dev,
1079                                     &in->variant.file_variant,
1080                                     inode_chunk, NULL);
1081         if (!tn)
1082                 return YAFFS_FAIL;
1083
1084         if (!nand_chunk)
1085                 /* Dummy insert, bail now */
1086                 return YAFFS_OK;
1087
1088         existing_cunk = yaffs_get_group_base(dev, tn, inode_chunk);
1089
1090         if (in_scan != 0) {
1091                 /* If we're scanning then we need to test for duplicates
1092                  * NB This does not need to be efficient since it should only
1093                  * happen when the power fails during a write, then only one
1094                  * chunk should ever be affected.
1095                  *
1096                  * Correction for YAFFS2: This could happen quite a lot and we
1097                  * need to think about efficiency! TODO
1098                  * Update: For backward scanning we don't need to re-read tags
1099                  * so this is quite cheap.
1100                  */
1101
1102                 if (existing_cunk > 0) {
1103                         /* NB Right now existing chunk will not be real
1104                          * chunk_id if the chunk group size > 1
1105                          * thus we have to do a FindChunkInFile to get the
1106                          * real chunk id.
1107                          *
1108                          * We have a duplicate now we need to decide which
1109                          * one to use:
1110                          *
1111                          * Backwards scanning YAFFS2: The old one is what
1112                          * we use, dump the new one.
1113                          * YAFFS1: Get both sets of tags and compare serial
1114                          * numbers.
1115                          */
1116
1117                         if (in_scan > 0) {
1118                                 /* Only do this for forward scanning */
1119                                 yaffs_rd_chunk_tags_nand(dev,
1120                                                          nand_chunk,
1121                                                          NULL, &new_tags);
1122
1123                                 /* Do a proper find */
1124                                 existing_cunk =
1125                                     yaffs_find_chunk_in_file(in, inode_chunk,
1126                                                              &existing_tags);
1127                         }
1128
1129                         if (existing_cunk <= 0) {
1130                                 /*Hoosterman - how did this happen? */
1131
1132                                 yaffs_trace(YAFFS_TRACE_ERROR,
1133                                         "yaffs tragedy: existing chunk < 0 in scan"
1134                                         );
1135
1136                         }
1137
1138                         /* NB The deleted flags should be false, otherwise
1139                          * the chunks will not be loaded during a scan
1140                          */
1141
1142                         if (in_scan > 0) {
1143                                 new_serial = new_tags.serial_number;
1144                                 existing_serial = existing_tags.serial_number;
1145                         }
1146
1147                         if ((in_scan > 0) &&
1148                             (existing_cunk <= 0 ||
1149                              ((existing_serial + 1) & 3) == new_serial)) {
1150                                 /* Forward scanning.
1151                                  * Use new
1152                                  * Delete the old one and drop through to
1153                                  * update the tnode
1154                                  */
1155                                 yaffs_chunk_del(dev, existing_cunk, 1,
1156                                                 __LINE__);
1157                         } else {
1158                                 /* Backward scanning or we want to use the
1159                                  * existing one
1160                                  * Delete the new one and return early so that
1161                                  * the tnode isn't changed
1162                                  */
1163                                 yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
1164                                 return YAFFS_OK;
1165                         }
1166                 }
1167
1168         }
1169
1170         if (existing_cunk == 0)
1171                 in->n_data_chunks++;
1172
1173         yaffs_load_tnode_0(dev, tn, inode_chunk, nand_chunk);
1174
1175         return YAFFS_OK;
1176 }
1177
1178 static void yaffs_soft_del_chunk(struct yaffs_dev *dev, int chunk)
1179 {
1180         struct yaffs_block_info *the_block;
1181         unsigned block_no;
1182
1183         yaffs_trace(YAFFS_TRACE_DELETION, "soft delete chunk %d", chunk);
1184
1185         block_no = chunk / dev->param.chunks_per_block;
1186         the_block = yaffs_get_block_info(dev, block_no);
1187         if (the_block) {
1188                 the_block->soft_del_pages++;
1189                 dev->n_free_chunks++;
1190                 yaffs2_update_oldest_dirty_seq(dev, block_no, the_block);
1191         }
1192 }
1193
1194 /* SoftDeleteWorker scans backwards through the tnode tree and soft deletes all
1195  * the chunks in the file.
1196  * All soft deleting does is increment the block's softdelete count and pulls
1197  * the chunk out of the tnode.
1198  * Thus, essentially this is the same as DeleteWorker except that the chunks
1199  * are soft deleted.
1200  */
1201
1202 static int yaffs_soft_del_worker(struct yaffs_obj *in, struct yaffs_tnode *tn,
1203                                  u32 level, int chunk_offset)
1204 {
1205         int i;
1206         int the_chunk;
1207         int all_done = 1;
1208         struct yaffs_dev *dev = in->my_dev;
1209
1210         if (!tn)
1211                 return 1;
1212
1213         if (level > 0) {
1214                 for (i = YAFFS_NTNODES_INTERNAL - 1;
1215                         all_done && i >= 0;
1216                         i--) {
1217                         if (tn->internal[i]) {
1218                                 all_done =
1219                                     yaffs_soft_del_worker(in,
1220                                         tn->internal[i],
1221                                         level - 1,
1222                                         (chunk_offset <<
1223                                         YAFFS_TNODES_INTERNAL_BITS)
1224                                         + i);
1225                                 if (all_done) {
1226                                         yaffs_free_tnode(dev,
1227                                                 tn->internal[i]);
1228                                         tn->internal[i] = NULL;
1229                                 } else {
1230                                         /* Can this happen? */
1231                                 }
1232                         }
1233                 }
1234                 return (all_done) ? 1 : 0;
1235         }
1236
1237         /* level 0 */
1238          for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0; i--) {
1239                 the_chunk = yaffs_get_group_base(dev, tn, i);
1240                 if (the_chunk) {
1241                         yaffs_soft_del_chunk(dev, the_chunk);
1242                         yaffs_load_tnode_0(dev, tn, i, 0);
1243                 }
1244         }
1245         return 1;
1246 }
1247
1248 static void yaffs_remove_obj_from_dir(struct yaffs_obj *obj)
1249 {
1250         struct yaffs_dev *dev = obj->my_dev;
1251         struct yaffs_obj *parent;
1252
1253         yaffs_verify_obj_in_dir(obj);
1254         parent = obj->parent;
1255
1256         yaffs_verify_dir(parent);
1257
1258         if (dev && dev->param.remove_obj_fn)
1259                 dev->param.remove_obj_fn(obj);
1260
1261         list_del_init(&obj->siblings);
1262         obj->parent = NULL;
1263
1264         yaffs_verify_dir(parent);
1265 }
1266
1267 void yaffs_add_obj_to_dir(struct yaffs_obj *directory, struct yaffs_obj *obj)
1268 {
1269         if (!directory) {
1270                 yaffs_trace(YAFFS_TRACE_ALWAYS,
1271                         "tragedy: Trying to add an object to a null pointer directory"
1272                         );
1273                 BUG();
1274                 return;
1275         }
1276         if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
1277                 yaffs_trace(YAFFS_TRACE_ALWAYS,
1278                         "tragedy: Trying to add an object to a non-directory"
1279                         );
1280                 BUG();
1281         }
1282
1283         if (obj->siblings.prev == NULL) {
1284                 /* Not initialised */
1285                 BUG();
1286         }
1287
1288         yaffs_verify_dir(directory);
1289
1290         yaffs_remove_obj_from_dir(obj);
1291
1292         /* Now add it */
1293         list_add(&obj->siblings, &directory->variant.dir_variant.children);
1294         obj->parent = directory;
1295
1296         if (directory == obj->my_dev->unlinked_dir
1297             || directory == obj->my_dev->del_dir) {
1298                 obj->unlinked = 1;
1299                 obj->my_dev->n_unlinked_files++;
1300                 obj->rename_allowed = 0;
1301         }
1302
1303         yaffs_verify_dir(directory);
1304         yaffs_verify_obj_in_dir(obj);
1305 }
1306
1307 static int yaffs_change_obj_name(struct yaffs_obj *obj,
1308                                  struct yaffs_obj *new_dir,
1309                                  const YCHAR *new_name, int force, int shadows)
1310 {
1311         int unlink_op;
1312         int del_op;
1313         struct yaffs_obj *existing_target;
1314
1315         if (new_dir == NULL)
1316                 new_dir = obj->parent;  /* use the old directory */
1317
1318         if (new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
1319                 yaffs_trace(YAFFS_TRACE_ALWAYS,
1320                         "tragedy: yaffs_change_obj_name: new_dir is not a directory"
1321                         );
1322                 BUG();
1323         }
1324
1325         unlink_op = (new_dir == obj->my_dev->unlinked_dir);
1326         del_op = (new_dir == obj->my_dev->del_dir);
1327
1328         existing_target = yaffs_find_by_name(new_dir, new_name);
1329
1330         /* If the object is a file going into the unlinked directory,
1331          *   then it is OK to just stuff it in since duplicate names are OK.
1332          *   else only proceed if the new name does not exist and we're putting
1333          *   it into a directory.
1334          */
1335         if (!(unlink_op || del_op || force ||
1336               shadows > 0 || !existing_target) ||
1337               new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
1338                 return YAFFS_FAIL;
1339
1340         yaffs_set_obj_name(obj, new_name);
1341         obj->dirty = 1;
1342         yaffs_add_obj_to_dir(new_dir, obj);
1343
1344         if (unlink_op)
1345                 obj->unlinked = 1;
1346
1347         /* If it is a deletion then we mark it as a shrink for gc  */
1348         if (yaffs_update_oh(obj, new_name, 0, del_op, shadows, NULL) >= 0)
1349                 return YAFFS_OK;
1350
1351         return YAFFS_FAIL;
1352 }
1353
1354 /*------------------------ Short Operations Cache ------------------------------
1355  *   In many situations where there is no high level buffering  a lot of
1356  *   reads might be short sequential reads, and a lot of writes may be short
1357  *   sequential writes. eg. scanning/writing a jpeg file.
1358  *   In these cases, a short read/write cache can provide a huge perfomance
1359  *   benefit with dumb-as-a-rock code.
1360  *   In Linux, the page cache provides read buffering and the short op cache
1361  *   provides write buffering.
1362  *
1363  *   There are a small number (~10) of cache chunks per device so that we don't
1364  *   need a very intelligent search.
1365  */
1366
1367 static int yaffs_obj_cache_dirty(struct yaffs_obj *obj)
1368 {
1369         struct yaffs_dev *dev = obj->my_dev;
1370         int i;
1371         struct yaffs_cache *cache;
1372         int n_caches = obj->my_dev->param.n_caches;
1373
1374         for (i = 0; i < n_caches; i++) {
1375                 cache = &dev->cache[i];
1376                 if (cache->object == obj && cache->dirty)
1377                         return 1;
1378         }
1379
1380         return 0;
1381 }
1382
1383 static void yaffs_flush_file_cache(struct yaffs_obj *obj)
1384 {
1385         struct yaffs_dev *dev = obj->my_dev;
1386         int lowest = -99;       /* Stop compiler whining. */
1387         int i;
1388         struct yaffs_cache *cache;
1389         int chunk_written = 0;
1390         int n_caches = obj->my_dev->param.n_caches;
1391
1392         if (n_caches < 1)
1393                 return;
1394         do {
1395                 cache = NULL;
1396
1397                 /* Find the lowest dirty chunk for this object */
1398                 for (i = 0; i < n_caches; i++) {
1399                         if (dev->cache[i].object == obj &&
1400                             dev->cache[i].dirty) {
1401                                 if (!cache ||
1402                                     dev->cache[i].chunk_id < lowest) {
1403                                         cache = &dev->cache[i];
1404                                         lowest = cache->chunk_id;
1405                                 }
1406                         }
1407                 }
1408
1409                 if (cache && !cache->locked) {
1410                         /* Write it out and free it up */
1411                         chunk_written =
1412                             yaffs_wr_data_obj(cache->object,
1413                                               cache->chunk_id,
1414                                               cache->data,
1415                                               cache->n_bytes, 1);
1416                         cache->dirty = 0;
1417                         cache->object = NULL;
1418                 }
1419         } while (cache && chunk_written > 0);
1420
1421         if (cache)
1422                 /* Hoosterman, disk full while writing cache out. */
1423                 yaffs_trace(YAFFS_TRACE_ERROR,
1424                         "yaffs tragedy: no space during cache write");
1425 }
1426
1427 /*yaffs_flush_whole_cache(dev)
1428  *
1429  *
1430  */
1431
1432 void yaffs_flush_whole_cache(struct yaffs_dev *dev)
1433 {
1434         struct yaffs_obj *obj;
1435         int n_caches = dev->param.n_caches;
1436         int i;
1437
1438         /* Find a dirty object in the cache and flush it...
1439          * until there are no further dirty objects.
1440          */
1441         do {
1442                 obj = NULL;
1443                 for (i = 0; i < n_caches && !obj; i++) {
1444                         if (dev->cache[i].object && dev->cache[i].dirty)
1445                                 obj = dev->cache[i].object;
1446                 }
1447                 if (obj)
1448                         yaffs_flush_file_cache(obj);
1449         } while (obj);
1450
1451 }
1452
1453 /* Grab us a cache chunk for use.
1454  * First look for an empty one.
1455  * Then look for the least recently used non-dirty one.
1456  * Then look for the least recently used dirty one...., flush and look again.
1457  */
1458 static struct yaffs_cache *yaffs_grab_chunk_worker(struct yaffs_dev *dev)
1459 {
1460         int i;
1461
1462         if (dev->param.n_caches > 0) {
1463                 for (i = 0; i < dev->param.n_caches; i++) {
1464                         if (!dev->cache[i].object)
1465                                 return &dev->cache[i];
1466                 }
1467         }
1468         return NULL;
1469 }
1470
1471 static struct yaffs_cache *yaffs_grab_chunk_cache(struct yaffs_dev *dev)
1472 {
1473         struct yaffs_cache *cache;
1474         struct yaffs_obj *the_obj;
1475         int usage;
1476         int i;
1477
1478         if (dev->param.n_caches < 1)
1479                 return NULL;
1480
1481         /* Try find a non-dirty one... */
1482
1483         cache = yaffs_grab_chunk_worker(dev);
1484
1485         if (!cache) {
1486                 /* They were all dirty, find the LRU object and flush
1487                  * its cache, then  find again.
1488                  * NB what's here is not very accurate,
1489                  * we actually flush the object with the LRU chunk.
1490                  */
1491
1492                 /* With locking we can't assume we can use entry zero,
1493                  * Set the_obj to a valid pointer for Coverity. */
1494                 the_obj = dev->cache[0].object;
1495                 usage = -1;
1496                 cache = NULL;
1497
1498                 for (i = 0; i < dev->param.n_caches; i++) {
1499                         if (dev->cache[i].object &&
1500                             !dev->cache[i].locked &&
1501                             (dev->cache[i].last_use < usage ||
1502                             !cache)) {
1503                                 usage = dev->cache[i].last_use;
1504                                 the_obj = dev->cache[i].object;
1505                                 cache = &dev->cache[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 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 = yaffs_strnlen(str, YAFFS_MAX_ALIAS_LENGTH);
2032         new_str = kmalloc((len + 1) * sizeof(YCHAR), GFP_NOFS);
2033         if (new_str) {
2034                 yaffs_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 && (dev->param.gc_control(dev) & 1) == 0)
2809                 return YAFFS_OK;
2810
2811         if (dev->gc_disable)
2812                 /* Bail out so we don't get recursive gc */
2813                 return YAFFS_OK;
2814
2815         /* This loop should pass the first time.
2816          * Only loops here if the collection does not increase space.
2817          */
2818
2819         do {
2820                 max_tries++;
2821
2822                 checkpt_block_adjust = yaffs_calc_checkpt_blocks_required(dev);
2823
2824                 min_erased =
2825                     dev->param.n_reserved_blocks + checkpt_block_adjust + 1;
2826                 erased_chunks =
2827                     dev->n_erased_blocks * dev->param.chunks_per_block;
2828
2829                 /* If we need a block soon then do aggressive gc. */
2830                 if (dev->n_erased_blocks < min_erased)
2831                         aggressive = 1;
2832                 else {
2833                         if (!background
2834                             && erased_chunks > (dev->n_free_chunks / 4))
2835                                 break;
2836
2837                         if (dev->gc_skip > 20)
2838                                 dev->gc_skip = 20;
2839                         if (erased_chunks < dev->n_free_chunks / 2 ||
2840                             dev->gc_skip < 1 || background)
2841                                 aggressive = 0;
2842                         else {
2843                                 dev->gc_skip--;
2844                                 break;
2845                         }
2846                 }
2847
2848                 dev->gc_skip = 5;
2849
2850                 /* If we don't already have a block being gc'd then see if we
2851                  * should start another */
2852
2853                 if (dev->gc_block < 1 && !aggressive) {
2854                         dev->gc_block = yaffs2_find_refresh_block(dev);
2855                         dev->gc_chunk = 0;
2856                         dev->n_clean_ups = 0;
2857                 }
2858                 if (dev->gc_block < 1) {
2859                         dev->gc_block =
2860                             yaffs_find_gc_block(dev, aggressive, background);
2861                         dev->gc_chunk = 0;
2862                         dev->n_clean_ups = 0;
2863                 }
2864
2865                 if (dev->gc_block > 0) {
2866                         dev->all_gcs++;
2867                         if (!aggressive)
2868                                 dev->passive_gc_count++;
2869
2870                         yaffs_trace(YAFFS_TRACE_GC,
2871                                 "yaffs: GC n_erased_blocks %d aggressive %d",
2872                                 dev->n_erased_blocks, aggressive);
2873
2874                         gc_ok = yaffs_gc_block(dev, dev->gc_block, aggressive);
2875                 }
2876
2877                 if (dev->n_erased_blocks < (dev->param.n_reserved_blocks) &&
2878                     dev->gc_block > 0) {
2879                         yaffs_trace(YAFFS_TRACE_GC,
2880                                 "yaffs: GC !!!no reclaim!!! n_erased_blocks %d after try %d block %d",
2881                                 dev->n_erased_blocks, max_tries,
2882                                 dev->gc_block);
2883                 }
2884         } while ((dev->n_erased_blocks < dev->param.n_reserved_blocks) &&
2885                  (dev->gc_block > 0) && (max_tries < 2));
2886
2887         return aggressive ? gc_ok : YAFFS_OK;
2888 }
2889
2890 /*
2891  * yaffs_bg_gc()
2892  * Garbage collects. Intended to be called from a background thread.
2893  * Returns non-zero if at least half the free chunks are erased.
2894  */
2895 int yaffs_bg_gc(struct yaffs_dev *dev, unsigned urgency)
2896 {
2897         int erased_chunks = dev->n_erased_blocks * dev->param.chunks_per_block;
2898
2899         yaffs_trace(YAFFS_TRACE_BACKGROUND, "Background gc %u", urgency);
2900
2901         yaffs_check_gc(dev, 1);
2902         return erased_chunks > dev->n_free_chunks / 2;
2903 }
2904
2905 /*-------------------- Data file manipulation -----------------*/
2906
2907 static int yaffs_rd_data_obj(struct yaffs_obj *in, int inode_chunk, u8 * buffer)
2908 {
2909         int nand_chunk = yaffs_find_chunk_in_file(in, inode_chunk, NULL);
2910
2911         if (nand_chunk >= 0)
2912                 return yaffs_rd_chunk_tags_nand(in->my_dev, nand_chunk,
2913                                                 buffer, NULL);
2914         else {
2915                 yaffs_trace(YAFFS_TRACE_NANDACCESS,
2916                         "Chunk %d not found zero instead",
2917                         nand_chunk);
2918                 /* get sane (zero) data if you read a hole */
2919                 memset(buffer, 0, in->my_dev->data_bytes_per_chunk);
2920                 return 0;
2921         }
2922
2923 }
2924
2925 void yaffs_chunk_del(struct yaffs_dev *dev, int chunk_id, int mark_flash,
2926                      int lyn)
2927 {
2928         int block;
2929         int page;
2930         struct yaffs_ext_tags tags;
2931         struct yaffs_block_info *bi;
2932
2933         if (chunk_id <= 0)
2934                 return;
2935
2936         dev->n_deletions++;
2937         block = chunk_id / dev->param.chunks_per_block;
2938         page = chunk_id % dev->param.chunks_per_block;
2939
2940         if (!yaffs_check_chunk_bit(dev, block, page))
2941                 yaffs_trace(YAFFS_TRACE_VERIFY,
2942                         "Deleting invalid chunk %d", chunk_id);
2943
2944         bi = yaffs_get_block_info(dev, block);
2945
2946         yaffs2_update_oldest_dirty_seq(dev, block, bi);
2947
2948         yaffs_trace(YAFFS_TRACE_DELETION,
2949                 "line %d delete of chunk %d",
2950                 lyn, chunk_id);
2951
2952         if (!dev->param.is_yaffs2 && mark_flash &&
2953             bi->block_state != YAFFS_BLOCK_STATE_COLLECTING) {
2954
2955                 memset(&tags, 0, sizeof(tags));
2956                 tags.is_deleted = 1;
2957                 yaffs_wr_chunk_tags_nand(dev, chunk_id, NULL, &tags);
2958                 yaffs_handle_chunk_update(dev, chunk_id, &tags);
2959         } else {
2960                 dev->n_unmarked_deletions++;
2961         }
2962
2963         /* Pull out of the management area.
2964          * If the whole block became dirty, this will kick off an erasure.
2965          */
2966         if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING ||
2967             bi->block_state == YAFFS_BLOCK_STATE_FULL ||
2968             bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCAN ||
2969             bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
2970                 dev->n_free_chunks++;
2971                 yaffs_clear_chunk_bit(dev, block, page);
2972                 bi->pages_in_use--;
2973
2974                 if (bi->pages_in_use == 0 &&
2975                     !bi->has_shrink_hdr &&
2976                     bi->block_state != YAFFS_BLOCK_STATE_ALLOCATING &&
2977                     bi->block_state != YAFFS_BLOCK_STATE_NEEDS_SCAN) {
2978                         yaffs_block_became_dirty(dev, block);
2979                 }
2980         }
2981 }
2982
2983 static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
2984                              const u8 *buffer, int n_bytes, int use_reserve)
2985 {
2986         /* Find old chunk Need to do this to get serial number
2987          * Write new one and patch into tree.
2988          * Invalidate old tags.
2989          */
2990
2991         int prev_chunk_id;
2992         struct yaffs_ext_tags prev_tags;
2993         int new_chunk_id;
2994         struct yaffs_ext_tags new_tags;
2995         struct yaffs_dev *dev = in->my_dev;
2996
2997         yaffs_check_gc(dev, 0);
2998
2999         /* Get the previous chunk at this location in the file if it exists.
3000          * If it does not exist then put a zero into the tree. This creates
3001          * the tnode now, rather than later when it is harder to clean up.
3002          */
3003         prev_chunk_id = yaffs_find_chunk_in_file(in, inode_chunk, &prev_tags);
3004         if (prev_chunk_id < 1 &&
3005             !yaffs_put_chunk_in_file(in, inode_chunk, 0, 0))
3006                 return 0;
3007
3008         /* Set up new tags */
3009         memset(&new_tags, 0, sizeof(new_tags));
3010
3011         new_tags.chunk_id = inode_chunk;
3012         new_tags.obj_id = in->obj_id;
3013         new_tags.serial_number =
3014             (prev_chunk_id > 0) ? prev_tags.serial_number + 1 : 1;
3015         new_tags.n_bytes = n_bytes;
3016
3017         if (n_bytes < 1 || n_bytes > dev->param.total_bytes_per_chunk) {
3018                 yaffs_trace(YAFFS_TRACE_ERROR,
3019                   "Writing %d bytes to chunk!!!!!!!!!",
3020                    n_bytes);
3021                 BUG();
3022         }
3023
3024         new_chunk_id =
3025             yaffs_write_new_chunk(dev, buffer, &new_tags, use_reserve);
3026
3027         if (new_chunk_id > 0) {
3028                 yaffs_put_chunk_in_file(in, inode_chunk, new_chunk_id, 0);
3029
3030                 if (prev_chunk_id > 0)
3031                         yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
3032
3033                 yaffs_verify_file_sane(in);
3034         }
3035         return new_chunk_id;
3036
3037 }
3038
3039
3040
3041 static int yaffs_do_xattrib_mod(struct yaffs_obj *obj, int set,
3042                                 const YCHAR *name, const void *value, int size,
3043                                 int flags)
3044 {
3045         struct yaffs_xattr_mod xmod;
3046         int result;
3047
3048         xmod.set = set;
3049         xmod.name = name;
3050         xmod.data = value;
3051         xmod.size = size;
3052         xmod.flags = flags;
3053         xmod.result = -ENOSPC;
3054
3055         result = yaffs_update_oh(obj, NULL, 0, 0, 0, &xmod);
3056
3057         if (result > 0)
3058                 return xmod.result;
3059         else
3060                 return -ENOSPC;
3061 }
3062
3063 static int yaffs_apply_xattrib_mod(struct yaffs_obj *obj, char *buffer,
3064                                    struct yaffs_xattr_mod *xmod)
3065 {
3066         int retval = 0;
3067         int x_offs = sizeof(struct yaffs_obj_hdr);
3068         struct yaffs_dev *dev = obj->my_dev;
3069         int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
3070         char *x_buffer = buffer + x_offs;
3071
3072         if (xmod->set)
3073                 retval =
3074                     nval_set(x_buffer, x_size, xmod->name, xmod->data,
3075                              xmod->size, xmod->flags);
3076         else
3077                 retval = nval_del(x_buffer, x_size, xmod->name);
3078
3079         obj->has_xattr = nval_hasvalues(x_buffer, x_size);
3080         obj->xattr_known = 1;
3081         xmod->result = retval;
3082
3083         return retval;
3084 }
3085
3086 static int yaffs_do_xattrib_fetch(struct yaffs_obj *obj, const YCHAR *name,
3087                                   void *value, int size)
3088 {
3089         char *buffer = NULL;
3090         int result;
3091         struct yaffs_ext_tags tags;
3092         struct yaffs_dev *dev = obj->my_dev;
3093         int x_offs = sizeof(struct yaffs_obj_hdr);
3094         int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
3095         char *x_buffer;
3096         int retval = 0;
3097
3098         if (obj->hdr_chunk < 1)
3099                 return -ENODATA;
3100
3101         /* If we know that the object has no xattribs then don't do all the
3102          * reading and parsing.
3103          */
3104         if (obj->xattr_known && !obj->has_xattr) {
3105                 if (name)
3106                         return -ENODATA;
3107                 else
3108                         return 0;
3109         }
3110
3111         buffer = (char *)yaffs_get_temp_buffer(dev);
3112         if (!buffer)
3113                 return -ENOMEM;
3114
3115         result =
3116             yaffs_rd_chunk_tags_nand(dev, obj->hdr_chunk, (u8 *) buffer, &tags);
3117
3118         if (result != YAFFS_OK)
3119                 retval = -ENOENT;
3120         else {
3121                 x_buffer = buffer + x_offs;
3122
3123                 if (!obj->xattr_known) {
3124                         obj->has_xattr = nval_hasvalues(x_buffer, x_size);
3125                         obj->xattr_known = 1;
3126                 }
3127
3128                 if (name)
3129                         retval = nval_get(x_buffer, x_size, name, value, size);
3130                 else
3131                         retval = nval_list(x_buffer, x_size, value, size);
3132         }
3133         yaffs_release_temp_buffer(dev, (u8 *) buffer);
3134         return retval;
3135 }
3136
3137 int yaffs_set_xattrib(struct yaffs_obj *obj, const YCHAR * name,
3138                       const void *value, int size, int flags)
3139 {
3140         return yaffs_do_xattrib_mod(obj, 1, name, value, size, flags);
3141 }
3142
3143 int yaffs_remove_xattrib(struct yaffs_obj *obj, const YCHAR * name)
3144 {
3145         return yaffs_do_xattrib_mod(obj, 0, name, NULL, 0, 0);
3146 }
3147
3148 int yaffs_get_xattrib(struct yaffs_obj *obj, const YCHAR * name, void *value,
3149                       int size)
3150 {
3151         return yaffs_do_xattrib_fetch(obj, name, value, size);
3152 }
3153
3154 int yaffs_list_xattrib(struct yaffs_obj *obj, char *buffer, int size)
3155 {
3156         return yaffs_do_xattrib_fetch(obj, NULL, buffer, size);
3157 }
3158
3159 static void yaffs_check_obj_details_loaded(struct yaffs_obj *in)
3160 {
3161         u8 *buf;
3162         struct yaffs_obj_hdr *oh;
3163         struct yaffs_dev *dev;
3164         struct yaffs_ext_tags tags;
3165
3166         if (!in || !in->lazy_loaded || in->hdr_chunk < 1)
3167                 return;
3168
3169         dev = in->my_dev;
3170         in->lazy_loaded = 0;
3171         buf = yaffs_get_temp_buffer(dev);
3172
3173         yaffs_rd_chunk_tags_nand(dev, in->hdr_chunk, buf, &tags);
3174         oh = (struct yaffs_obj_hdr *)buf;
3175
3176         in->yst_mode = oh->yst_mode;
3177         yaffs_load_attribs(in, oh);
3178         yaffs_set_obj_name_from_oh(in, oh);
3179
3180         if (in->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
3181                 in->variant.symlink_variant.alias =
3182                     yaffs_clone_str(oh->alias);
3183         }
3184         yaffs_release_temp_buffer(dev, buf);
3185 }
3186
3187 static void yaffs_load_name_from_oh(struct yaffs_dev *dev, YCHAR *name,
3188                                     const YCHAR *oh_name, int buff_size)
3189 {
3190 #ifdef CONFIG_YAFFS_AUTO_UNICODE
3191         if (dev->param.auto_unicode) {
3192                 if (*oh_name) {
3193                         /* It is an ASCII name, do an ASCII to
3194                          * unicode conversion */
3195                         const char *ascii_oh_name = (const char *)oh_name;
3196                         int n = buff_size - 1;
3197                         while (n > 0 && *ascii_oh_name) {
3198                                 *name = *ascii_oh_name;
3199                                 name++;
3200                                 ascii_oh_name++;
3201                                 n--;
3202                         }
3203                 } else {
3204                         yaffs_strncpy(name, oh_name + 1, buff_size - 1);
3205                 }
3206
3207                 return;
3208         }
3209 #endif
3210
3211         yaffs_strncpy(name, oh_name, buff_size - 1);
3212 }
3213
3214 static void yaffs_load_oh_from_name(struct yaffs_dev *dev, YCHAR *oh_name,
3215                                     const YCHAR *name)
3216 {
3217 #ifdef CONFIG_YAFFS_AUTO_UNICODE
3218         int is_ascii;
3219         YCHAR *w;
3220
3221         if (dev->param.auto_unicode) {
3222
3223                 is_ascii = 1;
3224                 w = name;
3225
3226                 /* Figure out if the name will fit in ascii character set */
3227                 while (is_ascii && *w) {
3228                         if ((*w) & 0xff00)
3229                                 is_ascii = 0;
3230                         w++;
3231                 }
3232
3233                 if (is_ascii) {
3234                         /* It is an ASCII name, so convert unicode to ascii */
3235                         char *ascii_oh_name = (char *)oh_name;
3236                         int n = YAFFS_MAX_NAME_LENGTH - 1;
3237                         while (n > 0 && *name) {
3238                                 *ascii_oh_name = *name;
3239                                 name++;
3240                                 ascii_oh_name++;
3241                                 n--;
3242                         }
3243                 } else {
3244                         /* Unicode name, so save starting at the second YCHAR */
3245                         *oh_name = 0;
3246                         yaffs_strncpy(oh_name + 1, name, YAFFS_MAX_NAME_LENGTH - 2);
3247                 }
3248
3249                 return;
3250         }
3251 #endif
3252
3253         yaffs_strncpy(oh_name, name, YAFFS_MAX_NAME_LENGTH - 1);
3254 }
3255
3256 /* UpdateObjectHeader updates the header on NAND for an object.
3257  * If name is not NULL, then that new name is used.
3258  */
3259 int yaffs_update_oh(struct yaffs_obj *in, const YCHAR *name, int force,
3260                     int is_shrink, int shadows, struct yaffs_xattr_mod *xmod)
3261 {
3262
3263         struct yaffs_block_info *bi;
3264         struct yaffs_dev *dev = in->my_dev;
3265         int prev_chunk_id;
3266         int ret_val = 0;
3267         int new_chunk_id;
3268         struct yaffs_ext_tags new_tags;
3269         struct yaffs_ext_tags old_tags;
3270         const YCHAR *alias = NULL;
3271         u8 *buffer = NULL;
3272         YCHAR old_name[YAFFS_MAX_NAME_LENGTH + 1];
3273         struct yaffs_obj_hdr *oh = NULL;
3274         loff_t file_size = 0;
3275
3276         yaffs_strcpy(old_name, _Y("silly old name"));
3277
3278         if (in->fake && in != dev->root_dir && !force && !xmod)
3279                 return ret_val;
3280
3281         yaffs_check_gc(dev, 0);
3282         yaffs_check_obj_details_loaded(in);
3283
3284         buffer = yaffs_get_temp_buffer(in->my_dev);
3285         oh = (struct yaffs_obj_hdr *)buffer;
3286
3287         prev_chunk_id = in->hdr_chunk;
3288
3289         if (prev_chunk_id > 0) {
3290                 yaffs_rd_chunk_tags_nand(dev, prev_chunk_id,
3291                                           buffer, &old_tags);
3292
3293                 yaffs_verify_oh(in, oh, &old_tags, 0);
3294                 memcpy(old_name, oh->name, sizeof(oh->name));
3295                 memset(buffer, 0xff, sizeof(struct yaffs_obj_hdr));
3296         } else {
3297                 memset(buffer, 0xff, dev->data_bytes_per_chunk);
3298         }
3299
3300         oh->type = in->variant_type;
3301         oh->yst_mode = in->yst_mode;
3302         oh->shadows_obj = oh->inband_shadowed_obj_id = shadows;
3303
3304         yaffs_load_attribs_oh(oh, in);
3305
3306         if (in->parent)
3307                 oh->parent_obj_id = in->parent->obj_id;
3308         else
3309                 oh->parent_obj_id = 0;
3310
3311         if (name && *name) {
3312                 memset(oh->name, 0, sizeof(oh->name));
3313                 yaffs_load_oh_from_name(dev, oh->name, name);
3314         } else if (prev_chunk_id > 0) {
3315                 memcpy(oh->name, old_name, sizeof(oh->name));
3316         } else {
3317                 memset(oh->name, 0, sizeof(oh->name));
3318         }
3319
3320         oh->is_shrink = is_shrink;
3321
3322         switch (in->variant_type) {
3323         case YAFFS_OBJECT_TYPE_UNKNOWN:
3324                 /* Should not happen */
3325                 break;
3326         case YAFFS_OBJECT_TYPE_FILE:
3327                 if (oh->parent_obj_id != YAFFS_OBJECTID_DELETED &&
3328                     oh->parent_obj_id != YAFFS_OBJECTID_UNLINKED)
3329                         file_size = in->variant.file_variant.file_size;
3330                 yaffs_oh_size_load(oh, file_size);
3331                 break;
3332         case YAFFS_OBJECT_TYPE_HARDLINK:
3333                 oh->equiv_id = in->variant.hardlink_variant.equiv_id;
3334                 break;
3335         case YAFFS_OBJECT_TYPE_SPECIAL:
3336                 /* Do nothing */
3337                 break;
3338         case YAFFS_OBJECT_TYPE_DIRECTORY:
3339                 /* Do nothing */
3340                 break;
3341         case YAFFS_OBJECT_TYPE_SYMLINK:
3342                 alias = in->variant.symlink_variant.alias;
3343                 if (!alias)
3344                         alias = _Y("no alias");
3345                 yaffs_strncpy(oh->alias, alias, YAFFS_MAX_ALIAS_LENGTH);
3346                 oh->alias[YAFFS_MAX_ALIAS_LENGTH] = 0;
3347                 break;
3348         }
3349
3350         /* process any xattrib modifications */
3351         if (xmod)
3352                 yaffs_apply_xattrib_mod(in, (char *)buffer, xmod);
3353
3354         /* Tags */
3355         memset(&new_tags, 0, sizeof(new_tags));
3356         in->serial++;
3357         new_tags.chunk_id = 0;
3358         new_tags.obj_id = in->obj_id;
3359         new_tags.serial_number = in->serial;
3360
3361         /* Add extra info for file header */
3362         new_tags.extra_available = 1;
3363         new_tags.extra_parent_id = oh->parent_obj_id;
3364         new_tags.extra_file_size = file_size;
3365         new_tags.extra_is_shrink = oh->is_shrink;
3366         new_tags.extra_equiv_id = oh->equiv_id;
3367         new_tags.extra_shadows = (oh->shadows_obj > 0) ? 1 : 0;
3368         new_tags.extra_obj_type = in->variant_type;
3369         yaffs_verify_oh(in, oh, &new_tags, 1);
3370
3371         /* Create new chunk in NAND */
3372         new_chunk_id =
3373             yaffs_write_new_chunk(dev, buffer, &new_tags,
3374                                   (prev_chunk_id > 0) ? 1 : 0);
3375
3376         if (buffer)
3377                 yaffs_release_temp_buffer(dev, buffer);
3378
3379         if (new_chunk_id < 0)
3380                 return new_chunk_id;
3381
3382         in->hdr_chunk = new_chunk_id;
3383
3384         if (prev_chunk_id > 0)
3385                 yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
3386
3387         if (!yaffs_obj_cache_dirty(in))
3388                 in->dirty = 0;
3389
3390         /* If this was a shrink, then mark the block
3391          * that the chunk lives on */
3392         if (is_shrink) {
3393                 bi = yaffs_get_block_info(in->my_dev,
3394                                           new_chunk_id /
3395                                           in->my_dev->param.chunks_per_block);
3396                 bi->has_shrink_hdr = 1;
3397         }
3398
3399
3400         return new_chunk_id;
3401 }
3402
3403 /*--------------------- File read/write ------------------------
3404  * Read and write have very similar structures.
3405  * In general the read/write has three parts to it
3406  * An incomplete chunk to start with (if the read/write is not chunk-aligned)
3407  * Some complete chunks
3408  * An incomplete chunk to end off with
3409  *
3410  * Curve-balls: the first chunk might also be the last chunk.
3411  */
3412
3413 int yaffs_file_rd(struct yaffs_obj *in, u8 * buffer, loff_t offset, int n_bytes)
3414 {
3415         int chunk;
3416         u32 start;
3417         int n_copy;
3418         int n = n_bytes;
3419         int n_done = 0;
3420         struct yaffs_cache *cache;
3421         struct yaffs_dev *dev;
3422
3423         dev = in->my_dev;
3424
3425         while (n > 0) {
3426                 yaffs_addr_to_chunk(dev, offset, &chunk, &start);
3427                 chunk++;
3428
3429                 /* OK now check for the curveball where the start and end are in
3430                  * the same chunk.
3431                  */
3432                 if ((start + n) < dev->data_bytes_per_chunk)
3433                         n_copy = n;
3434                 else
3435                         n_copy = dev->data_bytes_per_chunk - start;
3436
3437                 cache = yaffs_find_chunk_cache(in, chunk);
3438
3439                 /* If the chunk is already in the cache or it is less than
3440                  * a whole chunk or we're using inband tags then use the cache
3441                  * (if there is caching) else bypass the cache.
3442                  */
3443                 if (cache || n_copy != dev->data_bytes_per_chunk ||
3444                     dev->param.inband_tags) {
3445                         if (dev->param.n_caches > 0) {
3446
3447                                 /* If we can't find the data in the cache,
3448                                  * then load it up. */
3449
3450                                 if (!cache) {
3451                                         cache =
3452                                             yaffs_grab_chunk_cache(in->my_dev);
3453                                         cache->object = in;
3454                                         cache->chunk_id = chunk;
3455                                         cache->dirty = 0;
3456                                         cache->locked = 0;
3457                                         yaffs_rd_data_obj(in, chunk,
3458                                                           cache->data);
3459                                         cache->n_bytes = 0;
3460                                 }
3461
3462                                 yaffs_use_cache(dev, cache, 0);
3463
3464                                 cache->locked = 1;
3465
3466                                 memcpy(buffer, &cache->data[start], n_copy);
3467
3468                                 cache->locked = 0;
3469                         } else {
3470                                 /* Read into the local buffer then copy.. */
3471
3472                                 u8 *local_buffer =
3473                                     yaffs_get_temp_buffer(dev);
3474                                 yaffs_rd_data_obj(in, chunk, local_buffer);
3475
3476                                 memcpy(buffer, &local_buffer[start], n_copy);
3477
3478                                 yaffs_release_temp_buffer(dev, local_buffer);
3479                         }
3480                 } else {
3481                         /* A full chunk. Read directly into the buffer. */
3482                         yaffs_rd_data_obj(in, chunk, buffer);
3483                 }
3484                 n -= n_copy;
3485                 offset += n_copy;
3486                 buffer += n_copy;
3487                 n_done += n_copy;
3488         }
3489         return n_done;
3490 }
3491
3492 int yaffs_do_file_wr(struct yaffs_obj *in, const u8 *buffer, loff_t offset,
3493                      int n_bytes, int write_through)
3494 {
3495
3496         int chunk;
3497         u32 start;
3498         int n_copy;
3499         int n = n_bytes;
3500         int n_done = 0;
3501         int n_writeback;
3502         loff_t start_write = offset;
3503         int chunk_written = 0;
3504         u32 n_bytes_read;
3505         loff_t chunk_start;
3506         struct yaffs_dev *dev;
3507
3508         dev = in->my_dev;
3509
3510         while (n > 0 && chunk_written >= 0) {
3511                 yaffs_addr_to_chunk(dev, offset, &chunk, &start);
3512
3513                 if (((loff_t)chunk) *
3514                     dev->data_bytes_per_chunk + start != offset ||
3515                     start >= dev->data_bytes_per_chunk) {
3516                         yaffs_trace(YAFFS_TRACE_ERROR,
3517                                 "AddrToChunk of offset %lld gives chunk %d start %d",
3518                                 offset, chunk, start);
3519                 }
3520                 chunk++;        /* File pos to chunk in file offset */
3521
3522                 /* OK now check for the curveball where the start and end are in
3523                  * the same chunk.
3524                  */
3525
3526                 if ((start + n) < dev->data_bytes_per_chunk) {
3527                         n_copy = n;
3528
3529                         /* Now calculate how many bytes to write back....
3530                          * If we're overwriting and not writing to then end of
3531                          * file then we need to write back as much as was there
3532                          * before.
3533                          */
3534
3535                         chunk_start = (((loff_t)(chunk - 1)) *
3536                                         dev->data_bytes_per_chunk);
3537
3538                         if (chunk_start > in->variant.file_variant.file_size)
3539                                 n_bytes_read = 0;       /* Past end of file */
3540                         else
3541                                 n_bytes_read =
3542                                     in->variant.file_variant.file_size -
3543                                     chunk_start;
3544
3545                         if (n_bytes_read > dev->data_bytes_per_chunk)
3546                                 n_bytes_read = dev->data_bytes_per_chunk;
3547
3548                         n_writeback =
3549                             (n_bytes_read >
3550                              (start + n)) ? n_bytes_read : (start + n);
3551
3552                         if (n_writeback < 0 ||
3553                             n_writeback > dev->data_bytes_per_chunk)
3554                                 BUG();
3555
3556                 } else {
3557                         n_copy = dev->data_bytes_per_chunk - start;
3558                         n_writeback = dev->data_bytes_per_chunk;
3559                 }
3560
3561                 if (n_copy != dev->data_bytes_per_chunk ||
3562                     dev->param.inband_tags) {
3563                         /* An incomplete start or end chunk (or maybe both
3564                          * start and end chunk), or we're using inband tags,
3565                          * so we want to use the cache buffers.
3566                          */
3567                         if (dev->param.n_caches > 0) {
3568                                 struct yaffs_cache *cache;
3569
3570                                 /* If we can't find the data in the cache, then
3571                                  * load the cache */
3572                                 cache = yaffs_find_chunk_cache(in, chunk);
3573
3574                                 if (!cache &&
3575                                     yaffs_check_alloc_available(dev, 1)) {
3576                                         cache = yaffs_grab_chunk_cache(dev);
3577                                         cache->object = in;
3578                                         cache->chunk_id = chunk;
3579                                         cache->dirty = 0;
3580                                         cache->locked = 0;
3581                                         yaffs_rd_data_obj(in, chunk,
3582                                                           cache->data);
3583                                 } else if (cache &&
3584                                            !cache->dirty &&
3585                                            !yaffs_check_alloc_available(dev,
3586                                                                         1)) {
3587                                         /* Drop the cache if it was a read cache
3588                                          * item and no space check has been made
3589                                          * for it.
3590                                          */
3591                                         cache = NULL;
3592                                 }
3593
3594                                 if (cache) {
3595                                         yaffs_use_cache(dev, cache, 1);
3596                                         cache->locked = 1;
3597
3598                                         memcpy(&cache->data[start], buffer,
3599                                                n_copy);
3600
3601                                         cache->locked = 0;
3602                                         cache->n_bytes = n_writeback;
3603
3604                                         if (write_through) {
3605                                                 chunk_written =
3606                                                     yaffs_wr_data_obj
3607                                                     (cache->object,
3608                                                      cache->chunk_id,
3609                                                      cache->data,
3610                                                      cache->n_bytes, 1);
3611                                                 cache->dirty = 0;
3612                                         }
3613                                 } else {
3614                                         chunk_written = -1;     /* fail write */
3615                                 }
3616                         } else {
3617                                 /* An incomplete start or end chunk (or maybe
3618                                  * both start and end chunk). Read into the
3619                                  * local buffer then copy over and write back.
3620                                  */
3621
3622                                 u8 *local_buffer = yaffs_get_temp_buffer(dev);
3623
3624                                 yaffs_rd_data_obj(in, chunk, local_buffer);
3625                                 memcpy(&local_buffer[start], buffer, n_copy);
3626
3627                                 chunk_written =
3628                                     yaffs_wr_data_obj(in, chunk,
3629                                                       local_buffer,
3630                                                       n_writeback, 0);
3631
3632                                 yaffs_release_temp_buffer(dev, local_buffer);
3633                         }
3634                 } else {
3635                         /* A full chunk. Write directly from the buffer. */
3636
3637                         chunk_written =
3638                             yaffs_wr_data_obj(in, chunk, buffer,
3639                                               dev->data_bytes_per_chunk, 0);
3640
3641                         /* Since we've overwritten the cached data,
3642                          * we better invalidate it. */
3643                         yaffs_invalidate_chunk_cache(in, chunk);
3644                 }
3645
3646                 if (chunk_written >= 0) {
3647                         n -= n_copy;
3648                         offset += n_copy;
3649                         buffer += n_copy;
3650                         n_done += n_copy;
3651                 }
3652         }
3653
3654         /* Update file object */
3655
3656         if ((start_write + n_done) > in->variant.file_variant.file_size)
3657                 in->variant.file_variant.file_size = (start_write + n_done);
3658
3659         in->dirty = 1;
3660         return n_done;
3661 }
3662
3663 int yaffs_wr_file(struct yaffs_obj *in, const u8 *buffer, loff_t offset,
3664                   int n_bytes, int write_through)
3665 {
3666         yaffs2_handle_hole(in, offset);
3667         return yaffs_do_file_wr(in, buffer, offset, n_bytes, write_through);
3668 }
3669
3670 /* ---------------------- File resizing stuff ------------------ */
3671
3672 static void yaffs_prune_chunks(struct yaffs_obj *in, loff_t new_size)
3673 {
3674
3675         struct yaffs_dev *dev = in->my_dev;
3676         loff_t old_size = in->variant.file_variant.file_size;
3677         int i;
3678         int chunk_id;
3679         u32 dummy;
3680         int last_del;
3681         int start_del;
3682
3683         if (old_size > 0)
3684                 yaffs_addr_to_chunk(dev, old_size - 1, &last_del, &dummy);
3685         else
3686                 last_del = 0;
3687
3688         yaffs_addr_to_chunk(dev, new_size + dev->data_bytes_per_chunk - 1,
3689                                 &start_del, &dummy);
3690         last_del++;
3691         start_del++;
3692
3693         /* Delete backwards so that we don't end up with holes if
3694          * power is lost part-way through the operation.
3695          */
3696         for (i = last_del; i >= start_del; i--) {
3697                 /* NB this could be optimised somewhat,
3698                  * eg. could retrieve the tags and write them without
3699                  * using yaffs_chunk_del
3700                  */
3701
3702                 chunk_id = yaffs_find_del_file_chunk(in, i, NULL);
3703
3704                 if (chunk_id < 1)
3705                         continue;
3706
3707                 if (chunk_id <
3708                     (dev->internal_start_block * dev->param.chunks_per_block) ||
3709                     chunk_id >=
3710                     ((dev->internal_end_block + 1) *
3711                       dev->param.chunks_per_block)) {
3712                         yaffs_trace(YAFFS_TRACE_ALWAYS,
3713                                 "Found daft chunk_id %d for %d",
3714                                 chunk_id, i);
3715                 } else {
3716                         in->n_data_chunks--;
3717                         yaffs_chunk_del(dev, chunk_id, 1, __LINE__);
3718                 }
3719         }
3720 }
3721
3722 void yaffs_resize_file_down(struct yaffs_obj *obj, loff_t new_size)
3723 {
3724         int new_full;
3725         u32 new_partial;
3726         struct yaffs_dev *dev = obj->my_dev;
3727
3728         yaffs_addr_to_chunk(dev, new_size, &new_full, &new_partial);
3729
3730         yaffs_prune_chunks(obj, new_size);
3731
3732         if (new_partial != 0) {
3733                 int last_chunk = 1 + new_full;
3734                 u8 *local_buffer = yaffs_get_temp_buffer(dev);
3735
3736                 /* Rewrite the last chunk with its new size and zero pad */
3737                 yaffs_rd_data_obj(obj, last_chunk, local_buffer);
3738                 memset(local_buffer + new_partial, 0,
3739                        dev->data_bytes_per_chunk - new_partial);
3740
3741                 yaffs_wr_data_obj(obj, last_chunk, local_buffer,
3742                                   new_partial, 1);
3743
3744                 yaffs_release_temp_buffer(dev, local_buffer);
3745         }
3746
3747         obj->variant.file_variant.file_size = new_size;
3748
3749         yaffs_prune_tree(dev, &obj->variant.file_variant);
3750 }
3751
3752 int yaffs_resize_file(struct yaffs_obj *in, loff_t new_size)
3753 {
3754         struct yaffs_dev *dev = in->my_dev;
3755         loff_t old_size = in->variant.file_variant.file_size;
3756
3757         yaffs_flush_file_cache(in);
3758         yaffs_invalidate_whole_cache(in);
3759
3760         yaffs_check_gc(dev, 0);
3761
3762         if (in->variant_type != YAFFS_OBJECT_TYPE_FILE)
3763                 return YAFFS_FAIL;
3764
3765         if (new_size == old_size)
3766                 return YAFFS_OK;
3767
3768         if (new_size > old_size) {
3769                 yaffs2_handle_hole(in, new_size);
3770                 in->variant.file_variant.file_size = new_size;
3771         } else {
3772                 /* new_size < old_size */
3773                 yaffs_resize_file_down(in, new_size);
3774         }
3775
3776         /* Write a new object header to reflect the resize.
3777          * show we've shrunk the file, if need be
3778          * Do this only if the file is not in the deleted directories
3779          * and is not shadowed.
3780          */
3781         if (in->parent &&
3782             !in->is_shadowed &&
3783             in->parent->obj_id != YAFFS_OBJECTID_UNLINKED &&
3784             in->parent->obj_id != YAFFS_OBJECTID_DELETED)
3785                 yaffs_update_oh(in, NULL, 0, 0, 0, NULL);
3786
3787         return YAFFS_OK;
3788 }
3789
3790 int yaffs_flush_file(struct yaffs_obj *in, int update_time, int data_sync)
3791 {
3792         if (!in->dirty)
3793                 return YAFFS_OK;
3794
3795         yaffs_flush_file_cache(in);
3796
3797         if (data_sync)
3798                 return YAFFS_OK;
3799
3800         if (update_time)
3801                 yaffs_load_current_time(in, 0, 0);
3802
3803         return (yaffs_update_oh(in, NULL, 0, 0, 0, NULL) >= 0) ?
3804                                 YAFFS_OK : YAFFS_FAIL;
3805 }
3806
3807
3808 /* yaffs_del_file deletes the whole file data
3809  * and the inode associated with the file.
3810  * It does not delete the links associated with the file.
3811  */
3812 static int yaffs_unlink_file_if_needed(struct yaffs_obj *in)
3813 {
3814         int ret_val;
3815         int del_now = 0;
3816         struct yaffs_dev *dev = in->my_dev;
3817
3818         if (!in->my_inode)
3819                 del_now = 1;
3820
3821         if (del_now) {
3822                 ret_val =
3823                     yaffs_change_obj_name(in, in->my_dev->del_dir,
3824                                           _Y("deleted"), 0, 0);
3825                 yaffs_trace(YAFFS_TRACE_TRACING,
3826                         "yaffs: immediate deletion of file %d",
3827                         in->obj_id);
3828                 in->deleted = 1;
3829                 in->my_dev->n_deleted_files++;
3830                 if (dev->param.disable_soft_del || dev->param.is_yaffs2)
3831                         yaffs_resize_file(in, 0);
3832                 yaffs_soft_del_file(in);
3833         } else {
3834                 ret_val =
3835                     yaffs_change_obj_name(in, in->my_dev->unlinked_dir,
3836                                           _Y("unlinked"), 0, 0);
3837         }
3838         return ret_val;
3839 }
3840
3841 int yaffs_del_file(struct yaffs_obj *in)
3842 {
3843         int ret_val = YAFFS_OK;
3844         int deleted;    /* Need to cache value on stack if in is freed */
3845         struct yaffs_dev *dev = in->my_dev;
3846
3847         if (dev->param.disable_soft_del || dev->param.is_yaffs2)
3848                 yaffs_resize_file(in, 0);
3849
3850         if (in->n_data_chunks > 0) {
3851                 /* Use soft deletion if there is data in the file.
3852                  * That won't be the case if it has been resized to zero.
3853                  */
3854                 if (!in->unlinked)
3855                         ret_val = yaffs_unlink_file_if_needed(in);
3856
3857                 deleted = in->deleted;
3858
3859                 if (ret_val == YAFFS_OK && in->unlinked && !in->deleted) {
3860                         in->deleted = 1;
3861                         deleted = 1;
3862                         in->my_dev->n_deleted_files++;
3863                         yaffs_soft_del_file(in);
3864                 }
3865                 return deleted ? YAFFS_OK : YAFFS_FAIL;
3866         } else {
3867                 /* The file has no data chunks so we toss it immediately */
3868                 yaffs_free_tnode(in->my_dev, in->variant.file_variant.top);
3869                 in->variant.file_variant.top = NULL;
3870                 yaffs_generic_obj_del(in);
3871
3872                 return YAFFS_OK;
3873         }
3874 }
3875
3876 int yaffs_is_non_empty_dir(struct yaffs_obj *obj)
3877 {
3878         return (obj &&
3879                 obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY) &&
3880                 !(list_empty(&obj->variant.dir_variant.children));
3881 }
3882
3883 static int yaffs_del_dir(struct yaffs_obj *obj)
3884 {
3885         /* First check that the directory is empty. */
3886         if (yaffs_is_non_empty_dir(obj))
3887                 return YAFFS_FAIL;
3888
3889         return yaffs_generic_obj_del(obj);
3890 }
3891
3892 static int yaffs_del_symlink(struct yaffs_obj *in)
3893 {
3894         kfree(in->variant.symlink_variant.alias);
3895         in->variant.symlink_variant.alias = NULL;
3896
3897         return yaffs_generic_obj_del(in);
3898 }
3899
3900 static int yaffs_del_link(struct yaffs_obj *in)
3901 {
3902         /* remove this hardlink from the list associated with the equivalent
3903          * object
3904          */
3905         list_del_init(&in->hard_links);
3906         return yaffs_generic_obj_del(in);
3907 }
3908
3909 int yaffs_del_obj(struct yaffs_obj *obj)
3910 {
3911         int ret_val = -1;
3912
3913         switch (obj->variant_type) {
3914         case YAFFS_OBJECT_TYPE_FILE:
3915                 ret_val = yaffs_del_file(obj);
3916                 break;
3917         case YAFFS_OBJECT_TYPE_DIRECTORY:
3918                 if (!list_empty(&obj->variant.dir_variant.dirty)) {
3919                         yaffs_trace(YAFFS_TRACE_BACKGROUND,
3920                                 "Remove object %d from dirty directories",
3921                                 obj->obj_id);
3922                         list_del_init(&obj->variant.dir_variant.dirty);
3923                 }
3924                 return yaffs_del_dir(obj);
3925                 break;
3926         case YAFFS_OBJECT_TYPE_SYMLINK:
3927                 ret_val = yaffs_del_symlink(obj);
3928                 break;
3929         case YAFFS_OBJECT_TYPE_HARDLINK:
3930                 ret_val = yaffs_del_link(obj);
3931                 break;
3932         case YAFFS_OBJECT_TYPE_SPECIAL:
3933                 ret_val = yaffs_generic_obj_del(obj);
3934                 break;
3935         case YAFFS_OBJECT_TYPE_UNKNOWN:
3936                 ret_val = 0;
3937                 break;          /* should not happen. */
3938         }
3939         return ret_val;
3940 }
3941
3942 static int yaffs_unlink_worker(struct yaffs_obj *obj)
3943 {
3944         int del_now = 0;
3945
3946         if (!obj)
3947                 return YAFFS_FAIL;
3948
3949         if (!obj->my_inode)
3950                 del_now = 1;
3951
3952         yaffs_update_parent(obj->parent);
3953
3954         if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
3955                 return yaffs_del_link(obj);
3956         } else if (!list_empty(&obj->hard_links)) {
3957                 /* Curve ball: We're unlinking an object that has a hardlink.
3958                  *
3959                  * This problem arises because we are not strictly following
3960                  * The Linux link/inode model.
3961                  *
3962                  * We can't really delete the object.
3963                  * Instead, we do the following:
3964                  * - Select a hardlink.
3965                  * - Unhook it from the hard links
3966                  * - Move it from its parent directory so that the rename works.
3967                  * - Rename the object to the hardlink's name.
3968                  * - Delete the hardlink
3969                  */
3970
3971                 struct yaffs_obj *hl;
3972                 struct yaffs_obj *parent;
3973                 int ret_val;
3974                 YCHAR name[YAFFS_MAX_NAME_LENGTH + 1];
3975
3976                 hl = list_entry(obj->hard_links.next, struct yaffs_obj,
3977                                 hard_links);
3978
3979                 yaffs_get_obj_name(hl, name, YAFFS_MAX_NAME_LENGTH + 1);
3980                 parent = hl->parent;
3981
3982                 list_del_init(&hl->hard_links);
3983
3984                 yaffs_add_obj_to_dir(obj->my_dev->unlinked_dir, hl);
3985
3986                 ret_val = yaffs_change_obj_name(obj, parent, name, 0, 0);
3987
3988                 if (ret_val == YAFFS_OK)
3989                         ret_val = yaffs_generic_obj_del(hl);
3990
3991                 return ret_val;
3992
3993         } else if (del_now) {
3994                 switch (obj->variant_type) {
3995                 case YAFFS_OBJECT_TYPE_FILE:
3996                         return yaffs_del_file(obj);
3997                         break;
3998                 case YAFFS_OBJECT_TYPE_DIRECTORY:
3999                         list_del_init(&obj->variant.dir_variant.dirty);
4000                         return yaffs_del_dir(obj);
4001                         break;
4002                 case YAFFS_OBJECT_TYPE_SYMLINK:
4003                         return yaffs_del_symlink(obj);
4004                         break;
4005                 case YAFFS_OBJECT_TYPE_SPECIAL:
4006                         return yaffs_generic_obj_del(obj);
4007                         break;
4008                 case YAFFS_OBJECT_TYPE_HARDLINK:
4009                 case YAFFS_OBJECT_TYPE_UNKNOWN:
4010                 default:
4011                         return YAFFS_FAIL;
4012                 }
4013         } else if (yaffs_is_non_empty_dir(obj)) {
4014                 return YAFFS_FAIL;
4015         } else {
4016                 return yaffs_change_obj_name(obj, obj->my_dev->unlinked_dir,
4017                                                 _Y("unlinked"), 0, 0);
4018         }
4019 }
4020
4021 static int yaffs_unlink_obj(struct yaffs_obj *obj)
4022 {
4023         if (obj && obj->unlink_allowed)
4024                 return yaffs_unlink_worker(obj);
4025
4026         return YAFFS_FAIL;
4027 }
4028
4029 int yaffs_unlinker(struct yaffs_obj *dir, const YCHAR *name)
4030 {
4031         struct yaffs_obj *obj;
4032
4033         obj = yaffs_find_by_name(dir, name);
4034         return yaffs_unlink_obj(obj);
4035 }
4036
4037 /* Note:
4038  * If old_name is NULL then we take old_dir as the object to be renamed.
4039  */
4040 int yaffs_rename_obj(struct yaffs_obj *old_dir, const YCHAR *old_name,
4041                      struct yaffs_obj *new_dir, const YCHAR *new_name)
4042 {
4043         struct yaffs_obj *obj = NULL;
4044         struct yaffs_obj *existing_target = NULL;
4045         int force = 0;
4046         int result;
4047         struct yaffs_dev *dev;
4048
4049         if (!old_dir || old_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4050                 BUG();
4051                 return YAFFS_FAIL;
4052         }
4053         if (!new_dir || new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4054                 BUG();
4055                 return YAFFS_FAIL;
4056         }
4057
4058         dev = old_dir->my_dev;
4059
4060 #ifdef CONFIG_YAFFS_CASE_INSENSITIVE
4061         /* Special case for case insemsitive systems.
4062          * While look-up is case insensitive, the name isn't.
4063          * Therefore we might want to change x.txt to X.txt
4064          */
4065         if (old_dir == new_dir &&
4066                 old_name && new_name &&
4067                 yaffs_strcmp(old_name, new_name) == 0)
4068                 force = 1;
4069 #endif
4070
4071         if (yaffs_strnlen(new_name, YAFFS_MAX_NAME_LENGTH + 1) >
4072             YAFFS_MAX_NAME_LENGTH)
4073                 /* ENAMETOOLONG */
4074                 return YAFFS_FAIL;
4075
4076         if (old_name)
4077                 obj = yaffs_find_by_name(old_dir, old_name);
4078         else{
4079                 obj = old_dir;
4080                 old_dir = obj->parent;
4081         }
4082
4083         if (obj && obj->rename_allowed) {
4084                 /* Now handle an existing target, if there is one */
4085                 existing_target = yaffs_find_by_name(new_dir, new_name);
4086                 if (yaffs_is_non_empty_dir(existing_target)) {
4087                         return YAFFS_FAIL;      /* ENOTEMPTY */
4088                 } else if (existing_target && existing_target != obj) {
4089                         /* Nuke the target first, using shadowing,
4090                          * but only if it isn't the same object.
4091                          *
4092                          * Note we must disable gc here otherwise it can mess
4093                          * up the shadowing.
4094                          *
4095                          */
4096                         dev->gc_disable = 1;
4097                         yaffs_change_obj_name(obj, new_dir, new_name, force,
4098                                               existing_target->obj_id);
4099                         existing_target->is_shadowed = 1;
4100                         yaffs_unlink_obj(existing_target);
4101                         dev->gc_disable = 0;
4102                 }
4103
4104                 result = yaffs_change_obj_name(obj, new_dir, new_name, 1, 0);
4105
4106                 yaffs_update_parent(old_dir);
4107                 if (new_dir != old_dir)
4108                         yaffs_update_parent(new_dir);
4109
4110                 return result;
4111         }
4112         return YAFFS_FAIL;
4113 }
4114
4115 /*----------------------- Initialisation Scanning ---------------------- */
4116
4117 void yaffs_handle_shadowed_obj(struct yaffs_dev *dev, int obj_id,
4118                                int backward_scanning)
4119 {
4120         struct yaffs_obj *obj;
4121
4122         if (backward_scanning) {
4123                 /* Handle YAFFS2 case (backward scanning)
4124                  * If the shadowed object exists then ignore.
4125                  */
4126                 obj = yaffs_find_by_number(dev, obj_id);
4127                 if (obj)
4128                         return;
4129         }
4130
4131         /* Let's create it (if it does not exist) assuming it is a file so that
4132          * it can do shrinking etc.
4133          * We put it in unlinked dir to be cleaned up after the scanning
4134          */
4135         obj =
4136             yaffs_find_or_create_by_number(dev, obj_id, YAFFS_OBJECT_TYPE_FILE);
4137         if (!obj)
4138                 return;
4139         obj->is_shadowed = 1;
4140         yaffs_add_obj_to_dir(dev->unlinked_dir, obj);
4141         obj->variant.file_variant.shrink_size = 0;
4142         obj->valid = 1;         /* So that we don't read any other info. */
4143 }
4144
4145 void yaffs_link_fixup(struct yaffs_dev *dev, struct list_head *hard_list)
4146 {
4147         struct list_head *lh;
4148         struct list_head *save;
4149         struct yaffs_obj *hl;
4150         struct yaffs_obj *in;
4151
4152         list_for_each_safe(lh, save, hard_list) {
4153                 hl = list_entry(lh, struct yaffs_obj, hard_links);
4154                 in = yaffs_find_by_number(dev,
4155                                         hl->variant.hardlink_variant.equiv_id);
4156
4157                 if (in) {
4158                         /* Add the hardlink pointers */
4159                         hl->variant.hardlink_variant.equiv_obj = in;
4160                         list_add(&hl->hard_links, &in->hard_links);
4161                 } else {
4162                         /* Todo Need to report/handle this better.
4163                          * Got a problem... hardlink to a non-existant object
4164                          */
4165                         hl->variant.hardlink_variant.equiv_obj = NULL;
4166                         INIT_LIST_HEAD(&hl->hard_links);
4167                 }
4168         }
4169 }
4170
4171 static void yaffs_strip_deleted_objs(struct yaffs_dev *dev)
4172 {
4173         /*
4174          *  Sort out state of unlinked and deleted objects after scanning.
4175          */
4176         struct list_head *i;
4177         struct list_head *n;
4178         struct yaffs_obj *l;
4179
4180         if (dev->read_only)
4181                 return;
4182
4183         /* Soft delete all the unlinked files */
4184         list_for_each_safe(i, n,
4185                            &dev->unlinked_dir->variant.dir_variant.children) {
4186                 l = list_entry(i, struct yaffs_obj, siblings);
4187                 yaffs_del_obj(l);
4188         }
4189
4190         list_for_each_safe(i, n, &dev->del_dir->variant.dir_variant.children) {
4191                 l = list_entry(i, struct yaffs_obj, siblings);
4192                 yaffs_del_obj(l);
4193         }
4194 }
4195
4196 /*
4197  * This code iterates through all the objects making sure that they are rooted.
4198  * Any unrooted objects are re-rooted in lost+found.
4199  * An object needs to be in one of:
4200  * - Directly under deleted, unlinked
4201  * - Directly or indirectly under root.
4202  *
4203  * Note:
4204  *  This code assumes that we don't ever change the current relationships
4205  *  between directories:
4206  *   root_dir->parent == unlinked_dir->parent == del_dir->parent == NULL
4207  *   lost-n-found->parent == root_dir
4208  *
4209  * This fixes the problem where directories might have inadvertently been
4210  * deleted leaving the object "hanging" without being rooted in the
4211  * directory tree.
4212  */
4213
4214 static int yaffs_has_null_parent(struct yaffs_dev *dev, struct yaffs_obj *obj)
4215 {
4216         return (obj == dev->del_dir ||
4217                 obj == dev->unlinked_dir || obj == dev->root_dir);
4218 }
4219
4220 static void yaffs_fix_hanging_objs(struct yaffs_dev *dev)
4221 {
4222         struct yaffs_obj *obj;
4223         struct yaffs_obj *parent;
4224         int i;
4225         struct list_head *lh;
4226         struct list_head *n;
4227         int depth_limit;
4228         int hanging;
4229
4230         if (dev->read_only)
4231                 return;
4232
4233         /* Iterate through the objects in each hash entry,
4234          * looking at each object.
4235          * Make sure it is rooted.
4236          */
4237
4238         for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
4239                 list_for_each_safe(lh, n, &dev->obj_bucket[i].list) {
4240                         obj = list_entry(lh, struct yaffs_obj, hash_link);
4241                         parent = obj->parent;
4242
4243                         if (yaffs_has_null_parent(dev, obj)) {
4244                                 /* These directories are not hanging */
4245                                 hanging = 0;
4246                         } else if (!parent ||
4247                                    parent->variant_type !=
4248                                    YAFFS_OBJECT_TYPE_DIRECTORY) {
4249                                 hanging = 1;
4250                         } else if (yaffs_has_null_parent(dev, parent)) {
4251                                 hanging = 0;
4252                         } else {
4253                                 /*
4254                                  * Need to follow the parent chain to
4255                                  * see if it is hanging.
4256                                  */
4257                                 hanging = 0;
4258                                 depth_limit = 100;
4259
4260                                 while (parent != dev->root_dir &&
4261                                        parent->parent &&
4262                                        parent->parent->variant_type ==
4263                                        YAFFS_OBJECT_TYPE_DIRECTORY &&
4264                                        depth_limit > 0) {
4265                                         parent = parent->parent;
4266                                         depth_limit--;
4267                                 }
4268                                 if (parent != dev->root_dir)
4269                                         hanging = 1;
4270                         }
4271                         if (hanging) {
4272                                 yaffs_trace(YAFFS_TRACE_SCAN,
4273                                         "Hanging object %d moved to lost and found",
4274                                         obj->obj_id);
4275                                 yaffs_add_obj_to_dir(dev->lost_n_found, obj);
4276                         }
4277                 }
4278         }
4279 }
4280
4281 /*
4282  * Delete directory contents for cleaning up lost and found.
4283  */
4284 static void yaffs_del_dir_contents(struct yaffs_obj *dir)
4285 {
4286         struct yaffs_obj *obj;
4287         struct list_head *lh;
4288         struct list_head *n;
4289
4290         if (dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
4291                 BUG();
4292
4293         list_for_each_safe(lh, n, &dir->variant.dir_variant.children) {
4294                 obj = list_entry(lh, struct yaffs_obj, siblings);
4295                 if (obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY)
4296                         yaffs_del_dir_contents(obj);
4297                 yaffs_trace(YAFFS_TRACE_SCAN,
4298                         "Deleting lost_found object %d",
4299                         obj->obj_id);
4300                 yaffs_unlink_obj(obj);
4301         }
4302 }
4303
4304 static void yaffs_empty_l_n_f(struct yaffs_dev *dev)
4305 {
4306         yaffs_del_dir_contents(dev->lost_n_found);
4307 }
4308
4309
4310 struct yaffs_obj *yaffs_find_by_name(struct yaffs_obj *directory,
4311                                      const YCHAR *name)
4312 {
4313         int sum;
4314         struct list_head *i;
4315         YCHAR buffer[YAFFS_MAX_NAME_LENGTH + 1];
4316         struct yaffs_obj *l;
4317
4318         if (!name)
4319                 return NULL;
4320
4321         if (!directory) {
4322                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4323                         "tragedy: yaffs_find_by_name: null pointer directory"
4324                         );
4325                 BUG();
4326                 return NULL;
4327         }
4328         if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4329                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4330                         "tragedy: yaffs_find_by_name: non-directory"
4331                         );
4332                 BUG();
4333         }
4334
4335         sum = yaffs_calc_name_sum(name);
4336
4337         list_for_each(i, &directory->variant.dir_variant.children) {
4338                 l = list_entry(i, struct yaffs_obj, siblings);
4339
4340                 if (l->parent != directory)
4341                         BUG();
4342
4343                 yaffs_check_obj_details_loaded(l);
4344
4345                 /* Special case for lost-n-found */
4346                 if (l->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
4347                         if (!yaffs_strcmp(name, YAFFS_LOSTNFOUND_NAME))
4348                                 return l;
4349                 } else if (l->sum == sum || l->hdr_chunk <= 0) {
4350                         /* LostnFound chunk called Objxxx
4351                          * Do a real check
4352                          */
4353                         yaffs_get_obj_name(l, buffer,
4354                                 YAFFS_MAX_NAME_LENGTH + 1);
4355                         if (!yaffs_strncmp(name, buffer, YAFFS_MAX_NAME_LENGTH))
4356                                 return l;
4357                 }
4358         }
4359         return NULL;
4360 }
4361
4362 /* GetEquivalentObject dereferences any hard links to get to the
4363  * actual object.
4364  */
4365
4366 struct yaffs_obj *yaffs_get_equivalent_obj(struct yaffs_obj *obj)
4367 {
4368         if (obj && obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
4369                 obj = obj->variant.hardlink_variant.equiv_obj;
4370                 yaffs_check_obj_details_loaded(obj);
4371         }
4372         return obj;
4373 }
4374
4375 /*
4376  *  A note or two on object names.
4377  *  * If the object name is missing, we then make one up in the form objnnn
4378  *
4379  *  * ASCII names are stored in the object header's name field from byte zero
4380  *  * Unicode names are historically stored starting from byte zero.
4381  *
4382  * Then there are automatic Unicode names...
4383  * The purpose of these is to save names in a way that can be read as
4384  * ASCII or Unicode names as appropriate, thus allowing a Unicode and ASCII
4385  * system to share files.
4386  *
4387  * These automatic unicode are stored slightly differently...
4388  *  - If the name can fit in the ASCII character space then they are saved as
4389  *    ascii names as per above.
4390  *  - If the name needs Unicode then the name is saved in Unicode
4391  *    starting at oh->name[1].
4392
4393  */
4394 static void yaffs_fix_null_name(struct yaffs_obj *obj, YCHAR *name,
4395                                 int buffer_size)
4396 {
4397         /* Create an object name if we could not find one. */
4398         if (yaffs_strnlen(name, YAFFS_MAX_NAME_LENGTH) == 0) {
4399                 YCHAR local_name[20];
4400                 YCHAR num_string[20];
4401                 YCHAR *x = &num_string[19];
4402                 unsigned v = obj->obj_id;
4403                 num_string[19] = 0;
4404                 while (v > 0) {
4405                         x--;
4406                         *x = '0' + (v % 10);
4407                         v /= 10;
4408                 }
4409                 /* make up a name */
4410                 yaffs_strcpy(local_name, YAFFS_LOSTNFOUND_PREFIX);
4411                 yaffs_strcat(local_name, x);
4412                 yaffs_strncpy(name, local_name, buffer_size - 1);
4413         }
4414 }
4415
4416 int yaffs_get_obj_name(struct yaffs_obj *obj, YCHAR *name, int buffer_size)
4417 {
4418         memset(name, 0, buffer_size * sizeof(YCHAR));
4419         yaffs_check_obj_details_loaded(obj);
4420         if (obj->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
4421                 yaffs_strncpy(name, YAFFS_LOSTNFOUND_NAME, buffer_size - 1);
4422         } else if (obj->short_name[0]) {
4423                 yaffs_strcpy(name, obj->short_name);
4424         } else if (obj->hdr_chunk > 0) {
4425                 u8 *buffer = yaffs_get_temp_buffer(obj->my_dev);
4426
4427                 struct yaffs_obj_hdr *oh = (struct yaffs_obj_hdr *)buffer;
4428
4429                 memset(buffer, 0, obj->my_dev->data_bytes_per_chunk);
4430
4431                 if (obj->hdr_chunk > 0) {
4432                         yaffs_rd_chunk_tags_nand(obj->my_dev,
4433                                                  obj->hdr_chunk,
4434                                                  buffer, NULL);
4435                 }
4436                 yaffs_load_name_from_oh(obj->my_dev, name, oh->name,
4437                                         buffer_size);
4438
4439                 yaffs_release_temp_buffer(obj->my_dev, buffer);
4440         }
4441
4442         yaffs_fix_null_name(obj, name, buffer_size);
4443
4444         return yaffs_strnlen(name, YAFFS_MAX_NAME_LENGTH);
4445 }
4446
4447 loff_t yaffs_get_obj_length(struct yaffs_obj *obj)
4448 {
4449         /* Dereference any hard linking */
4450         obj = yaffs_get_equivalent_obj(obj);
4451
4452         if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
4453                 return obj->variant.file_variant.file_size;
4454         if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
4455                 if (!obj->variant.symlink_variant.alias)
4456                         return 0;
4457                 return yaffs_strnlen(obj->variant.symlink_variant.alias,
4458                                      YAFFS_MAX_ALIAS_LENGTH);
4459         } else {
4460                 /* Only a directory should drop through to here */
4461                 return obj->my_dev->data_bytes_per_chunk;
4462         }
4463 }
4464
4465 int yaffs_get_obj_link_count(struct yaffs_obj *obj)
4466 {
4467         int count = 0;
4468         struct list_head *i;
4469
4470         if (!obj->unlinked)
4471                 count++;        /* the object itself */
4472
4473         list_for_each(i, &obj->hard_links)
4474             count++;            /* add the hard links; */
4475
4476         return count;
4477 }
4478
4479 int yaffs_get_obj_inode(struct yaffs_obj *obj)
4480 {
4481         obj = yaffs_get_equivalent_obj(obj);
4482
4483         return obj->obj_id;
4484 }
4485
4486 unsigned yaffs_get_obj_type(struct yaffs_obj *obj)
4487 {
4488         obj = yaffs_get_equivalent_obj(obj);
4489
4490         switch (obj->variant_type) {
4491         case YAFFS_OBJECT_TYPE_FILE:
4492                 return DT_REG;
4493                 break;
4494         case YAFFS_OBJECT_TYPE_DIRECTORY:
4495                 return DT_DIR;
4496                 break;
4497         case YAFFS_OBJECT_TYPE_SYMLINK:
4498                 return DT_LNK;
4499                 break;
4500         case YAFFS_OBJECT_TYPE_HARDLINK:
4501                 return DT_REG;
4502                 break;
4503         case YAFFS_OBJECT_TYPE_SPECIAL:
4504                 if (S_ISFIFO(obj->yst_mode))
4505                         return DT_FIFO;
4506                 if (S_ISCHR(obj->yst_mode))
4507                         return DT_CHR;
4508                 if (S_ISBLK(obj->yst_mode))
4509                         return DT_BLK;
4510                 if (S_ISSOCK(obj->yst_mode))
4511                         return DT_SOCK;
4512                 return DT_REG;
4513                 break;
4514         default:
4515                 return DT_REG;
4516                 break;
4517         }
4518 }
4519
4520 YCHAR *yaffs_get_symlink_alias(struct yaffs_obj *obj)
4521 {
4522         obj = yaffs_get_equivalent_obj(obj);
4523         if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK)
4524                 return yaffs_clone_str(obj->variant.symlink_variant.alias);
4525         else
4526                 return yaffs_clone_str(_Y(""));
4527 }
4528
4529 /*--------------------------- Initialisation code -------------------------- */
4530
4531 static int yaffs_check_dev_fns(const struct yaffs_dev *dev)
4532 {
4533         /* Common functions, gotta have */
4534         if (!dev->param.erase_fn || !dev->param.initialise_flash_fn)
4535                 return 0;
4536
4537         /* Can use the "with tags" style interface for yaffs1 or yaffs2 */
4538         if (dev->param.write_chunk_tags_fn &&
4539             dev->param.read_chunk_tags_fn &&
4540             !dev->param.write_chunk_fn &&
4541             !dev->param.read_chunk_fn &&
4542             dev->param.bad_block_fn && dev->param.query_block_fn)
4543                 return 1;
4544
4545         /* Can use the "spare" style interface for yaffs1 */
4546         if (!dev->param.is_yaffs2 &&
4547             !dev->param.write_chunk_tags_fn &&
4548             !dev->param.read_chunk_tags_fn &&
4549             dev->param.write_chunk_fn &&
4550             dev->param.read_chunk_fn &&
4551             !dev->param.bad_block_fn && !dev->param.query_block_fn)
4552                 return 1;
4553
4554         return 0;               /* bad */
4555 }
4556
4557 static int yaffs_create_initial_dir(struct yaffs_dev *dev)
4558 {
4559         /* Initialise the unlinked, deleted, root and lost+found directories */
4560         dev->lost_n_found = dev->root_dir = NULL;
4561         dev->unlinked_dir = dev->del_dir = NULL;
4562         dev->unlinked_dir =
4563             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_UNLINKED, S_IFDIR);
4564         dev->del_dir =
4565             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_DELETED, S_IFDIR);
4566         dev->root_dir =
4567             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_ROOT,
4568                                   YAFFS_ROOT_MODE | S_IFDIR);
4569         dev->lost_n_found =
4570             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_LOSTNFOUND,
4571                                   YAFFS_LOSTNFOUND_MODE | S_IFDIR);
4572
4573         if (dev->lost_n_found && dev->root_dir && dev->unlinked_dir
4574             && dev->del_dir) {
4575                 yaffs_add_obj_to_dir(dev->root_dir, dev->lost_n_found);
4576                 return YAFFS_OK;
4577         }
4578         return YAFFS_FAIL;
4579 }
4580
4581 int yaffs_guts_initialise(struct yaffs_dev *dev)
4582 {
4583         int init_failed = 0;
4584         unsigned x;
4585         int bits;
4586
4587         yaffs_trace(YAFFS_TRACE_TRACING, "yaffs: yaffs_guts_initialise()");
4588
4589         /* Check stuff that must be set */
4590
4591         if (!dev) {
4592                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4593                         "yaffs: Need a device"
4594                         );
4595                 return YAFFS_FAIL;
4596         }
4597
4598         if (dev->is_mounted) {
4599                 yaffs_trace(YAFFS_TRACE_ALWAYS, "device already mounted");
4600                 return YAFFS_FAIL;
4601         }
4602
4603         dev->internal_start_block = dev->param.start_block;
4604         dev->internal_end_block = dev->param.end_block;
4605         dev->block_offset = 0;
4606         dev->chunk_offset = 0;
4607         dev->n_free_chunks = 0;
4608
4609         dev->gc_block = 0;
4610
4611         if (dev->param.start_block == 0) {
4612                 dev->internal_start_block = dev->param.start_block + 1;
4613                 dev->internal_end_block = dev->param.end_block + 1;
4614                 dev->block_offset = 1;
4615                 dev->chunk_offset = dev->param.chunks_per_block;
4616         }
4617
4618         /* Check geometry parameters. */
4619
4620         if ((!dev->param.inband_tags && dev->param.is_yaffs2 &&
4621                 dev->param.total_bytes_per_chunk < 1024) ||
4622                 (!dev->param.is_yaffs2 &&
4623                         dev->param.total_bytes_per_chunk < 512) ||
4624                 (dev->param.inband_tags && !dev->param.is_yaffs2) ||
4625                  dev->param.chunks_per_block < 2 ||
4626                  dev->param.n_reserved_blocks < 2 ||
4627                 dev->internal_start_block <= 0 ||
4628                 dev->internal_end_block <= 0 ||
4629                 dev->internal_end_block <=
4630                 (dev->internal_start_block + dev->param.n_reserved_blocks + 2)
4631                 ) {
4632                 /* otherwise it is too small */
4633                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4634                         "NAND geometry problems: chunk size %d, type is yaffs%s, inband_tags %d ",
4635                         dev->param.total_bytes_per_chunk,
4636                         dev->param.is_yaffs2 ? "2" : "",
4637                         dev->param.inband_tags);
4638                 return YAFFS_FAIL;
4639         }
4640
4641         if (yaffs_init_nand(dev) != YAFFS_OK) {
4642                 yaffs_trace(YAFFS_TRACE_ALWAYS, "InitialiseNAND failed");
4643                 return YAFFS_FAIL;
4644         }
4645
4646         /* Sort out space for inband tags, if required */
4647         if (dev->param.inband_tags)
4648                 dev->data_bytes_per_chunk =
4649                     dev->param.total_bytes_per_chunk -
4650                     sizeof(struct yaffs_packed_tags2_tags_only);
4651         else
4652                 dev->data_bytes_per_chunk = dev->param.total_bytes_per_chunk;
4653
4654         /* Got the right mix of functions? */
4655         if (!yaffs_check_dev_fns(dev)) {
4656                 /* Function missing */
4657                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4658                         "device function(s) missing or wrong");
4659
4660                 return YAFFS_FAIL;
4661         }
4662
4663         /* Finished with most checks. Further checks happen later on too. */
4664
4665         dev->is_mounted = 1;
4666
4667         /* OK now calculate a few things for the device */
4668
4669         /*
4670          *  Calculate all the chunk size manipulation numbers:
4671          */
4672         x = dev->data_bytes_per_chunk;
4673         /* We always use dev->chunk_shift and dev->chunk_div */
4674         dev->chunk_shift = calc_shifts(x);
4675         x >>= dev->chunk_shift;
4676         dev->chunk_div = x;
4677         /* We only use chunk mask if chunk_div is 1 */
4678         dev->chunk_mask = (1 << dev->chunk_shift) - 1;
4679
4680         /*
4681          * Calculate chunk_grp_bits.
4682          * We need to find the next power of 2 > than internal_end_block
4683          */
4684
4685         x = dev->param.chunks_per_block * (dev->internal_end_block + 1);
4686
4687         bits = calc_shifts_ceiling(x);
4688
4689         /* Set up tnode width if wide tnodes are enabled. */
4690         if (!dev->param.wide_tnodes_disabled) {
4691                 /* bits must be even so that we end up with 32-bit words */
4692                 if (bits & 1)
4693                         bits++;
4694                 if (bits < 16)
4695                         dev->tnode_width = 16;
4696                 else
4697                         dev->tnode_width = bits;
4698         } else {
4699                 dev->tnode_width = 16;
4700         }
4701
4702         dev->tnode_mask = (1 << dev->tnode_width) - 1;
4703
4704         /* Level0 Tnodes are 16 bits or wider (if wide tnodes are enabled),
4705          * so if the bitwidth of the
4706          * chunk range we're using is greater than 16 we need
4707          * to figure out chunk shift and chunk_grp_size
4708          */
4709
4710         if (bits <= dev->tnode_width)
4711                 dev->chunk_grp_bits = 0;
4712         else
4713                 dev->chunk_grp_bits = bits - dev->tnode_width;
4714
4715         dev->tnode_size = (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8;
4716         if (dev->tnode_size < sizeof(struct yaffs_tnode))
4717                 dev->tnode_size = sizeof(struct yaffs_tnode);
4718
4719         dev->chunk_grp_size = 1 << dev->chunk_grp_bits;
4720
4721         if (dev->param.chunks_per_block < dev->chunk_grp_size) {
4722                 /* We have a problem because the soft delete won't work if
4723                  * the chunk group size > chunks per block.
4724                  * This can be remedied by using larger "virtual blocks".
4725                  */
4726                 yaffs_trace(YAFFS_TRACE_ALWAYS, "chunk group too large");
4727
4728                 return YAFFS_FAIL;
4729         }
4730
4731         /* Finished verifying the device, continue with initialisation */
4732
4733         /* More device initialisation */
4734         dev->all_gcs = 0;
4735         dev->passive_gc_count = 0;
4736         dev->oldest_dirty_gc_count = 0;
4737         dev->bg_gcs = 0;
4738         dev->gc_block_finder = 0;
4739         dev->buffered_block = -1;
4740         dev->doing_buffered_block_rewrite = 0;
4741         dev->n_deleted_files = 0;
4742         dev->n_bg_deletions = 0;
4743         dev->n_unlinked_files = 0;
4744         dev->n_ecc_fixed = 0;
4745         dev->n_ecc_unfixed = 0;
4746         dev->n_tags_ecc_fixed = 0;
4747         dev->n_tags_ecc_unfixed = 0;
4748         dev->n_erase_failures = 0;
4749         dev->n_erased_blocks = 0;
4750         dev->gc_disable = 0;
4751         dev->has_pending_prioritised_gc = 1;
4752                 /* Assume the worst for now, will get fixed on first GC */
4753         INIT_LIST_HEAD(&dev->dirty_dirs);
4754         dev->oldest_dirty_seq = 0;
4755         dev->oldest_dirty_block = 0;
4756
4757         /* Initialise temporary buffers and caches. */
4758         if (!yaffs_init_tmp_buffers(dev))
4759                 init_failed = 1;
4760
4761         dev->cache = NULL;
4762         dev->gc_cleanup_list = NULL;
4763
4764         if (!init_failed && dev->param.n_caches > 0) {
4765                 int i;
4766                 void *buf;
4767                 int cache_bytes =
4768                     dev->param.n_caches * sizeof(struct yaffs_cache);
4769
4770                 if (dev->param.n_caches > YAFFS_MAX_SHORT_OP_CACHES)
4771                         dev->param.n_caches = YAFFS_MAX_SHORT_OP_CACHES;
4772
4773                 dev->cache = kmalloc(cache_bytes, GFP_NOFS);
4774
4775                 buf = (u8 *) dev->cache;
4776
4777                 if (dev->cache)
4778                         memset(dev->cache, 0, cache_bytes);
4779
4780                 for (i = 0; i < dev->param.n_caches && buf; i++) {
4781                         dev->cache[i].object = NULL;
4782                         dev->cache[i].last_use = 0;
4783                         dev->cache[i].dirty = 0;
4784                         dev->cache[i].data = buf =
4785                             kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
4786                 }
4787                 if (!buf)
4788                         init_failed = 1;
4789
4790                 dev->cache_last_use = 0;
4791         }
4792
4793         dev->cache_hits = 0;
4794
4795         if (!init_failed) {
4796                 dev->gc_cleanup_list =
4797                     kmalloc(dev->param.chunks_per_block * sizeof(u32),
4798                                         GFP_NOFS);
4799                 if (!dev->gc_cleanup_list)
4800                         init_failed = 1;
4801         }
4802
4803         if (dev->param.is_yaffs2)
4804                 dev->param.use_header_file_size = 1;
4805
4806         if (!init_failed && !yaffs_init_blocks(dev))
4807                 init_failed = 1;
4808
4809         yaffs_init_tnodes_and_objs(dev);
4810
4811         if (!init_failed && !yaffs_create_initial_dir(dev))
4812                 init_failed = 1;
4813
4814         if (!init_failed && dev->param.is_yaffs2 &&
4815                 !dev->param.disable_summary &&
4816                 !yaffs_summary_init(dev))
4817                 init_failed = 1;
4818
4819         if (!init_failed) {
4820                 /* Now scan the flash. */
4821                 if (dev->param.is_yaffs2) {
4822                         if (yaffs2_checkpt_restore(dev)) {
4823                                 yaffs_check_obj_details_loaded(dev->root_dir);
4824                                 yaffs_trace(YAFFS_TRACE_CHECKPOINT |
4825                                         YAFFS_TRACE_MOUNT,
4826                                         "yaffs: restored from checkpoint"
4827                                         );
4828                         } else {
4829
4830                                 /* Clean up the mess caused by an aborted
4831                                  * checkpoint load then scan backwards.
4832                                  */
4833                                 yaffs_deinit_blocks(dev);
4834
4835                                 yaffs_deinit_tnodes_and_objs(dev);
4836
4837                                 dev->n_erased_blocks = 0;
4838                                 dev->n_free_chunks = 0;
4839                                 dev->alloc_block = -1;
4840                                 dev->alloc_page = -1;
4841                                 dev->n_deleted_files = 0;
4842                                 dev->n_unlinked_files = 0;
4843                                 dev->n_bg_deletions = 0;
4844
4845                                 if (!init_failed && !yaffs_init_blocks(dev))
4846                                         init_failed = 1;
4847
4848                                 yaffs_init_tnodes_and_objs(dev);
4849
4850                                 if (!init_failed
4851                                     && !yaffs_create_initial_dir(dev))
4852                                         init_failed = 1;
4853
4854                                 if (!init_failed && !yaffs2_scan_backwards(dev))
4855                                         init_failed = 1;
4856                         }
4857                 } else if (!yaffs1_scan(dev)) {
4858                         init_failed = 1;
4859                 }
4860
4861                 yaffs_strip_deleted_objs(dev);
4862                 yaffs_fix_hanging_objs(dev);
4863                 if (dev->param.empty_lost_n_found)
4864                         yaffs_empty_l_n_f(dev);
4865         }
4866
4867         if (init_failed) {
4868                 /* Clean up the mess */
4869                 yaffs_trace(YAFFS_TRACE_TRACING,
4870                   "yaffs: yaffs_guts_initialise() aborted.");
4871
4872                 yaffs_deinitialise(dev);
4873                 return YAFFS_FAIL;
4874         }
4875
4876         /* Zero out stats */
4877         dev->n_page_reads = 0;
4878         dev->n_page_writes = 0;
4879         dev->n_erasures = 0;
4880         dev->n_gc_copies = 0;
4881         dev->n_retried_writes = 0;
4882
4883         dev->n_retired_blocks = 0;
4884
4885         yaffs_verify_free_chunks(dev);
4886         yaffs_verify_blocks(dev);
4887
4888         /* Clean up any aborted checkpoint data */
4889         if (!dev->is_checkpointed && dev->blocks_in_checkpt > 0)
4890                 yaffs2_checkpt_invalidate(dev);
4891
4892         yaffs_trace(YAFFS_TRACE_TRACING,
4893           "yaffs: yaffs_guts_initialise() done.");
4894         return YAFFS_OK;
4895 }
4896
4897 void yaffs_deinitialise(struct yaffs_dev *dev)
4898 {
4899         if (dev->is_mounted) {
4900                 int i;
4901
4902                 yaffs_deinit_blocks(dev);
4903                 yaffs_deinit_tnodes_and_objs(dev);
4904                 yaffs_summary_deinit(dev);
4905
4906                 if (dev->param.n_caches > 0 && dev->cache) {
4907
4908                         for (i = 0; i < dev->param.n_caches; i++) {
4909                                 kfree(dev->cache[i].data);
4910                                 dev->cache[i].data = NULL;
4911                         }
4912
4913                         kfree(dev->cache);
4914                         dev->cache = NULL;
4915                 }
4916
4917                 kfree(dev->gc_cleanup_list);
4918
4919                 for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++)
4920                         kfree(dev->temp_buffer[i].buffer);
4921
4922                 dev->is_mounted = 0;
4923
4924                 if (dev->param.deinitialise_flash_fn)
4925                         dev->param.deinitialise_flash_fn(dev);
4926         }
4927 }
4928
4929 int yaffs_count_free_chunks(struct yaffs_dev *dev)
4930 {
4931         int n_free = 0;
4932         int b;
4933         struct yaffs_block_info *blk;
4934
4935         blk = dev->block_info;
4936         for (b = dev->internal_start_block; b <= dev->internal_end_block; b++) {
4937                 switch (blk->block_state) {
4938                 case YAFFS_BLOCK_STATE_EMPTY:
4939                 case YAFFS_BLOCK_STATE_ALLOCATING:
4940                 case YAFFS_BLOCK_STATE_COLLECTING:
4941                 case YAFFS_BLOCK_STATE_FULL:
4942                         n_free +=
4943                             (dev->param.chunks_per_block - blk->pages_in_use +
4944                              blk->soft_del_pages);
4945                         break;
4946                 default:
4947                         break;
4948                 }
4949                 blk++;
4950         }
4951         return n_free;
4952 }
4953
4954 int yaffs_get_n_free_chunks(struct yaffs_dev *dev)
4955 {
4956         /* This is what we report to the outside world */
4957         int n_free;
4958         int n_dirty_caches;
4959         int blocks_for_checkpt;
4960         int i;
4961
4962         n_free = dev->n_free_chunks;
4963         n_free += dev->n_deleted_files;
4964
4965         /* Now count and subtract the number of dirty chunks in the cache. */
4966
4967         for (n_dirty_caches = 0, i = 0; i < dev->param.n_caches; i++) {
4968                 if (dev->cache[i].dirty)
4969                         n_dirty_caches++;
4970         }
4971
4972         n_free -= n_dirty_caches;
4973
4974         n_free -=
4975             ((dev->param.n_reserved_blocks + 1) * dev->param.chunks_per_block);
4976
4977         /* Now figure checkpoint space and report that... */
4978         blocks_for_checkpt = yaffs_calc_checkpt_blocks_required(dev);
4979
4980         n_free -= (blocks_for_checkpt * dev->param.chunks_per_block);
4981
4982         if (n_free < 0)
4983                 n_free = 0;
4984
4985         return n_free;
4986 }
4987
4988 /*\
4989  * Marshalling functions to get loff_t file sizes into aand out of
4990  * object headers.
4991  */
4992 void yaffs_oh_size_load(struct yaffs_obj_hdr *oh, loff_t fsize)
4993 {
4994         oh->file_size_low = (fsize & 0xFFFFFFFF);
4995         oh->file_size_high = ((fsize >> 32) & 0xFFFFFFFF);
4996 }
4997
4998 loff_t yaffs_oh_to_size(struct yaffs_obj_hdr *oh)
4999 {
5000         loff_t retval;
5001
5002         if (~(oh->file_size_high))
5003                 retval = (((loff_t) oh->file_size_high) << 32) |
5004                         (((loff_t) oh->file_size_low) & 0xFFFFFFFF);
5005         else
5006                 retval = (loff_t) oh->file_size_low;
5007
5008         return retval;
5009 }