yaffs_guts.c

   1 /*
   2  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
   3  *
   4  * Copyright (C) 2002-2018 Aleph One Ltd.
   5  *
   6  * Created by Charles Manning <charles@aleph1.co.uk>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include "yportenv.h"
  14 #include "yaffs_trace.h"
  15
  16 #include "yaffs_guts.h"
  17
  18 #include "yaffs_cache.h"
  19 #include "yaffs_endian.h"
  20 #include "yaffs_getblockinfo.h"
  21 #include "yaffs_tagscompat.h"
  22 #include "yaffs_tagsmarshall.h"
  23 #include "yaffs_nand.h"
  24 #include "yaffs_yaffs1.h"
  25 #include "yaffs_yaffs2.h"
  26 #include "yaffs_bitmap.h"
  27 #include "yaffs_verify.h"
  28 #include "yaffs_nand.h"
  29 #include "yaffs_packedtags2.h"
  30 #include "yaffs_nameval.h"
  31 #include "yaffs_allocator.h"
  32 #include "yaffs_attribs.h"
  33 #include "yaffs_summary.h"
  34
  35 /* Note YAFFS_GC_GOOD_ENOUGH must be <= YAFFS_GC_PASSIVE_THRESHOLD */
  36 #define YAFFS_GC_GOOD_ENOUGH 2
  37 #define YAFFS_GC_PASSIVE_THRESHOLD 4
  38
  39 #include "yaffs_ecc.h"
  40
  41 /* Forward declarations */
  42
  43 static void yaffs_fix_null_name(struct yaffs_obj *obj, YCHAR *name,
  44                                 int buffer_size);
  45
  46 /* Function to calculate chunk and offset */
  47
  48 void yaffs_addr_to_chunk(struct yaffs_dev *dev, loff_t addr,
  49                                 int *chunk_out, u32 *offset_out)
  50 {
  51         int chunk;
  52         u32 offset;
  53
  54         chunk = (u32) (addr >> dev->chunk_shift);
  55
  56         if (dev->chunk_div == 1) {
  57                 /* easy power of 2 case */
  58                 offset = (u32) (addr & dev->chunk_mask);
  59         } else {
  60                 /* Non power-of-2 case */
  61
  62                 loff_t chunk_base;
  63
  64                 chunk /= dev->chunk_div;
  65
  66                 chunk_base = ((loff_t) chunk) * dev->data_bytes_per_chunk;
  67                 offset = (u32) (addr - chunk_base);
  68         }
  69
  70         *chunk_out = chunk;
  71         *offset_out = offset;
  72 }
  73
  74 /* Function to return the number of shifts for a power of 2 greater than or
  75  * equal to the given number
  76  * Note we don't try to cater for all possible numbers and this does not have to
  77  * be hellishly efficient.
  78  */
  79
  80 static inline u32 calc_shifts_ceiling(u32 x)
  81 {
  82         int extra_bits;
  83         int shifts;
  84
  85         shifts = extra_bits = 0;
  86
  87         while (x > 1) {
  88                 if (x & 1)
  89                         extra_bits++;
  90                 x >>= 1;
  91                 shifts++;
  92         }
  93
  94         if (extra_bits)
  95                 shifts++;
  96
  97         return shifts;
  98 }
  99
 100 /* Function to return the number of shifts to get a 1 in bit 0
 101  */
 102
 103 static inline u32 calc_shifts(u32 x)
 104 {
 105         u32 shifts;
 106
 107         shifts = 0;
 108
 109         if (!x)
 110                 return 0;
 111
 112         while (!(x & 1)) {
 113                 x >>= 1;
 114                 shifts++;
 115         }
 116
 117         return shifts;
 118 }
 119
 120 /*
 121  * Temporary buffer manipulations.
 122  */
 123
 124 static int yaffs_init_tmp_buffers(struct yaffs_dev *dev)
 125 {
 126         int i;
 127         u8 *buf = (u8 *) 1;
 128
 129         memset(dev->temp_buffer, 0, sizeof(dev->temp_buffer));
 130
 131         for (i = 0; buf && i < YAFFS_N_TEMP_BUFFERS; i++) {
 132                 dev->temp_buffer[i].in_use = 0;
 133                 buf = kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
 134                 dev->temp_buffer[i].buffer = buf;
 135         }
 136
 137         return buf ? YAFFS_OK : YAFFS_FAIL;
 138 }
 139
 140 u8 *yaffs_get_temp_buffer(struct yaffs_dev * dev)
 141 {
 142         int i;
 143
 144         dev->temp_in_use++;
 145         if (dev->temp_in_use > dev->max_temp)
 146                 dev->max_temp = dev->temp_in_use;
 147
 148         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
 149                 if (dev->temp_buffer[i].in_use == 0) {
 150                         dev->temp_buffer[i].in_use = 1;
 151                         return dev->temp_buffer[i].buffer;
 152                 }
 153         }
 154
 155         yaffs_trace(YAFFS_TRACE_BUFFERS, "Out of temp buffers");
 156         /*
 157          * If we got here then we have to allocate an unmanaged one
 158          * This is not good.
 159          */
 160
 161         dev->unmanaged_buffer_allocs++;
 162         return kmalloc(dev->data_bytes_per_chunk, GFP_NOFS);
 163
 164 }
 165
 166 void yaffs_release_temp_buffer(struct yaffs_dev *dev, u8 *buffer)
 167 {
 168         int i;
 169
 170         dev->temp_in_use--;
 171
 172         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
 173                 if (dev->temp_buffer[i].buffer == buffer) {
 174                         dev->temp_buffer[i].in_use = 0;
 175                         return;
 176                 }
 177         }
 178
 179         if (buffer) {
 180                 /* assume it is an unmanaged one. */
 181                 yaffs_trace(YAFFS_TRACE_BUFFERS,
 182                         "Releasing unmanaged temp buffer");
 183                 kfree(buffer);
 184                 dev->unmanaged_buffer_deallocs++;
 185         }
 186
 187 }
 188
 189 /*
 190  * Functions for robustisizing TODO
 191  *
 192  */
 193
 194 static void yaffs_handle_chunk_wr_ok(struct yaffs_dev *dev, int nand_chunk,
 195                                      const u8 *data,
 196                                      const struct yaffs_ext_tags *tags)
 197 {
 198         (void) dev;
 199         (void) nand_chunk;
 200         (void) data;
 201         (void) tags;
 202 }
 203
 204 static void yaffs_handle_chunk_update(struct yaffs_dev *dev, int nand_chunk,
 205                                       const struct yaffs_ext_tags *tags)
 206 {
 207         (void) dev;
 208         (void) nand_chunk;
 209         (void) tags;
 210 }
 211
 212 void yaffs_handle_chunk_error(struct yaffs_dev *dev,
 213                               struct yaffs_block_info *bi)
 214 {
 215         if (!bi->gc_prioritise) {
 216                 bi->gc_prioritise = 1;
 217                 dev->has_pending_prioritised_gc = 1;
 218                 bi->chunk_error_strikes++;
 219
 220                 if (bi->chunk_error_strikes > 3) {
 221                         bi->needs_retiring = 1; /* Too many stikes, so retire */
 222                         yaffs_trace(YAFFS_TRACE_ALWAYS,
 223                                 "yaffs: Block struck out");
 224
 225                 }
 226         }
 227 }
 228
 229 static void yaffs_handle_chunk_wr_error(struct yaffs_dev *dev, int nand_chunk,
 230                                         int erased_ok)
 231 {
 232         int flash_block = nand_chunk / dev->param.chunks_per_block;
 233         struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
 234
 235         yaffs_handle_chunk_error(dev, bi);
 236
 237         if (erased_ok) {
 238                 /* Was an actual write failure,
 239                  * so mark the block for retirement.*/
 240                 bi->needs_retiring = 1;
 241                 yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
 242                   "**>> Block %d needs retiring", flash_block);
 243         }
 244
 245         /* Delete the chunk */
 246         yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
 247         yaffs_skip_rest_of_block(dev);
 248 }
 249
 250 /*
 251  * Verification code
 252  */
 253
 254 /*
 255  *  Simple hash function. Needs to have a reasonable spread
 256  */
 257
 258 static inline int yaffs_hash_fn(int n)
 259 {
 260         if (n < 0)
 261                 n = -n;
 262         return n % YAFFS_NOBJECT_BUCKETS;
 263 }
 264
 265 /*
 266  * Access functions to useful fake objects.
 267  * Note that root might have a presence in NAND if permissions are set.
 268  */
 269
 270 struct yaffs_obj *yaffs_root(struct yaffs_dev *dev)
 271 {
 272         return dev->root_dir;
 273 }
 274
 275 struct yaffs_obj *yaffs_lost_n_found(struct yaffs_dev *dev)
 276 {
 277         return dev->lost_n_found;
 278 }
 279
 280 /*
 281  *  Erased NAND checking functions
 282  */
 283
 284 int yaffs_check_ff(u8 *buffer, int n_bytes)
 285 {
 286         /* Horrible, slow implementation */
 287         while (n_bytes--) {
 288                 if (*buffer != 0xff)
 289                         return 0;
 290                 buffer++;
 291         }
 292         return 1;
 293 }
 294
 295 static int yaffs_check_chunk_erased(struct yaffs_dev *dev, int nand_chunk)
 296 {
 297         int retval = YAFFS_OK;
 298         u8 *data = yaffs_get_temp_buffer(dev);
 299         struct yaffs_ext_tags tags;
 300         int result;
 301
 302         result = yaffs_rd_chunk_tags_nand(dev, nand_chunk, data, &tags);
 303
 304         if (result == YAFFS_FAIL ||
 305             tags.ecc_result > YAFFS_ECC_RESULT_NO_ERROR)
 306                 retval = YAFFS_FAIL;
 307
 308         if (!yaffs_check_ff(data, dev->data_bytes_per_chunk) ||
 309                 tags.chunk_used) {
 310                 yaffs_trace(YAFFS_TRACE_NANDACCESS,
 311                         "Chunk %d not erased", nand_chunk);
 312                 retval = YAFFS_FAIL;
 313         }
 314
 315         yaffs_release_temp_buffer(dev, data);
 316
 317         return retval;
 318
 319 }
 320
 321 static int yaffs_verify_chunk_written(struct yaffs_dev *dev,
 322                                       int nand_chunk,
 323                                       const u8 *data,
 324                                       struct yaffs_ext_tags *tags)
 325 {
 326         int retval = YAFFS_OK;
 327         struct yaffs_ext_tags temp_tags;
 328         u8 *buffer = yaffs_get_temp_buffer(dev);
 329         int result;
 330
 331         result = yaffs_rd_chunk_tags_nand(dev, nand_chunk, buffer, &temp_tags);
 332         if (result == YAFFS_FAIL ||
 333             memcmp(buffer, data, dev->data_bytes_per_chunk) ||
 334             temp_tags.obj_id != tags->obj_id ||
 335             temp_tags.chunk_id != tags->chunk_id ||
 336             temp_tags.n_bytes != tags->n_bytes)
 337                 retval = YAFFS_FAIL;
 338
 339         yaffs_release_temp_buffer(dev, buffer);
 340
 341         return retval;
 342 }
 343
 344
 345 int yaffs_check_alloc_available(struct yaffs_dev *dev, int n_chunks)
 346 {
 347         int reserved_chunks;
 348         int reserved_blocks = dev->param.n_reserved_blocks;
 349         int checkpt_blocks;
 350
 351         checkpt_blocks = yaffs_calc_checkpt_blocks_required(dev);
 352
 353         reserved_chunks =
 354             (reserved_blocks + checkpt_blocks) * dev->param.chunks_per_block;
 355
 356         return (dev->n_free_chunks > (reserved_chunks + n_chunks));
 357 }
 358
 359 static int yaffs_find_alloc_block(struct yaffs_dev *dev)
 360 {
 361         u32 i;
 362         struct yaffs_block_info *bi;
 363
 364         if (dev->n_erased_blocks < 1) {
 365                 /* Hoosterman we've got a problem.
 366                  * Can't get space to gc
 367                  */
 368                 yaffs_trace(YAFFS_TRACE_ERROR,
 369                   "yaffs tragedy: no more erased blocks");
 370
 371                 return -1;
 372         }
 373
 374         /* Find an empty block. */
 375
 376         for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
 377                 dev->alloc_block_finder++;
 378                 if (dev->alloc_block_finder < (int)dev->internal_start_block
 379                     || dev->alloc_block_finder > (int)dev->internal_end_block) {
 380                         dev->alloc_block_finder = dev->internal_start_block;
 381                 }
 382
 383                 bi = yaffs_get_block_info(dev, dev->alloc_block_finder);
 384
 385                 if (bi->block_state == YAFFS_BLOCK_STATE_EMPTY) {
 386                         bi->block_state = YAFFS_BLOCK_STATE_ALLOCATING;
 387                         dev->seq_number++;
 388                         bi->seq_number = dev->seq_number;
 389                         dev->n_erased_blocks--;
 390                         yaffs_trace(YAFFS_TRACE_ALLOCATE,
 391                           "Allocated block %d, seq  %d, %d left" ,
 392                            dev->alloc_block_finder, dev->seq_number,
 393                            dev->n_erased_blocks);
 394                         return dev->alloc_block_finder;
 395                 }
 396         }
 397
 398         yaffs_trace(YAFFS_TRACE_ALWAYS,
 399                 "yaffs tragedy: no more erased blocks, but there should have been %d",
 400                 dev->n_erased_blocks);
 401
 402         return -1;
 403 }
 404
 405 static int yaffs_alloc_chunk(struct yaffs_dev *dev, int use_reserver,
 406                              struct yaffs_block_info **block_ptr)
 407 {
 408         int ret_val;
 409         struct yaffs_block_info *bi;
 410
 411         if (dev->alloc_block < 0) {
 412                 /* Get next block to allocate off */
 413                 dev->alloc_block = yaffs_find_alloc_block(dev);
 414                 dev->alloc_page = 0;
 415         }
 416
 417         if (!use_reserver && !yaffs_check_alloc_available(dev, 1)) {
 418                 /* No space unless we're allowed to use the reserve. */
 419                 return -1;
 420         }
 421
 422         if (dev->n_erased_blocks < (int)dev->param.n_reserved_blocks
 423             && dev->alloc_page == 0)
 424                 yaffs_trace(YAFFS_TRACE_ALLOCATE, "Allocating reserve");
 425
 426         /* Next page please.... */
 427         if (dev->alloc_block >= 0) {
 428                 bi = yaffs_get_block_info(dev, dev->alloc_block);
 429
 430                 ret_val = (dev->alloc_block * dev->param.chunks_per_block) +
 431                     dev->alloc_page;
 432                 bi->pages_in_use++;
 433                 yaffs_set_chunk_bit(dev, dev->alloc_block, dev->alloc_page);
 434
 435                 dev->alloc_page++;
 436
 437                 dev->n_free_chunks--;
 438
 439                 /* If the block is full set the state to full */
 440                 if (dev->alloc_page >= dev->param.chunks_per_block) {
 441                         bi->block_state = YAFFS_BLOCK_STATE_FULL;
 442                         dev->alloc_block = -1;
 443                 }
 444
 445                 if (block_ptr)
 446                         *block_ptr = bi;
 447
 448                 return ret_val;
 449         }
 450
 451         yaffs_trace(YAFFS_TRACE_ERROR,
 452                 "!!!!!!!!! Allocator out !!!!!!!!!!!!!!!!!");
 453
 454         return -1;
 455 }
 456
 457 static int yaffs_get_erased_chunks(struct yaffs_dev *dev)
 458 {
 459         int n;
 460
 461         n = dev->n_erased_blocks * dev->param.chunks_per_block;
 462
 463         if (dev->alloc_block > 0)
 464                 n += (dev->param.chunks_per_block - dev->alloc_page);
 465
 466         return n;
 467
 468 }
 469
 470 /*
 471  * yaffs_skip_rest_of_block() skips over the rest of the allocation block
 472  * if we don't want to write to it.
 473  */
 474 void yaffs_skip_rest_of_block(struct yaffs_dev *dev)
 475 {
 476         struct yaffs_block_info *bi;
 477
 478         if (dev->alloc_block > 0) {
 479                 bi = yaffs_get_block_info(dev, dev->alloc_block);
 480                 if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING) {
 481                         bi->block_state = YAFFS_BLOCK_STATE_FULL;
 482                         dev->alloc_block = -1;
 483                 }
 484         }
 485 }
 486
 487 static int yaffs_write_new_chunk(struct yaffs_dev *dev,
 488                                  const u8 *data,
 489                                  struct yaffs_ext_tags *tags, int use_reserver)
 490 {
 491         u32 attempts = 0;
 492         int write_ok = 0;
 493         int chunk;
 494
 495         yaffs2_checkpt_invalidate(dev);
 496
 497         do {
 498                 struct yaffs_block_info *bi = 0;
 499                 int erased_ok = 0;
 500
 501                 chunk = yaffs_alloc_chunk(dev, use_reserver, &bi);
 502                 if (chunk < 0) {
 503                         /* no space */
 504                         break;
 505                 }
 506
 507                 /* First check this chunk is erased, if it needs
 508                  * checking.  The checking policy (unless forced
 509                  * always on) is as follows:
 510                  *
 511                  * Check the first page we try to write in a block.
 512                  * If the check passes then we don't need to check any
 513                  * more.        If the check fails, we check again...
 514                  * If the block has been erased, we don't need to check.
 515                  *
 516                  * However, if the block has been prioritised for gc,
 517                  * then we think there might be something odd about
 518                  * this block and stop using it.
 519                  *
 520                  * Rationale: We should only ever see chunks that have
 521                  * not been erased if there was a partially written
 522                  * chunk due to power loss.  This checking policy should
 523                  * catch that case with very few checks and thus save a
 524                  * lot of checks that are most likely not needed.
 525                  *
 526                  * Mods to the above
 527                  * If an erase check fails or the write fails we skip the
 528                  * rest of the block.
 529                  */
 530
 531                 /* let's give it a try */
 532                 attempts++;
 533
 534                 if (dev->param.always_check_erased)
 535                         bi->skip_erased_check = 0;
 536
 537                 if (!bi->skip_erased_check) {
 538                         erased_ok = yaffs_check_chunk_erased(dev, chunk);
 539                         if (erased_ok != YAFFS_OK) {
 540                                 yaffs_trace(YAFFS_TRACE_ERROR,
 541                                   "**>> yaffs chunk %d was not erased",
 542                                   chunk);
 543
 544                                 /* If not erased, delete this one,
 545                                  * skip rest of block and
 546                                  * try another chunk */
 547                                 yaffs_chunk_del(dev, chunk, 1, __LINE__);
 548                                 yaffs_skip_rest_of_block(dev);
 549                                 continue;
 550                         }
 551                 }
 552
 553                 write_ok = yaffs_wr_chunk_tags_nand(dev, chunk, data, tags);
 554
 555                 if (!bi->skip_erased_check)
 556                         write_ok =
 557                             yaffs_verify_chunk_written(dev, chunk, data, tags);
 558
 559                 if (write_ok != YAFFS_OK) {
 560                         /* Clean up aborted write, skip to next block and
 561                          * try another chunk */
 562                         yaffs_handle_chunk_wr_error(dev, chunk, erased_ok);
 563                         continue;
 564                 }
 565
 566                 bi->skip_erased_check = 1;
 567
 568                 /* Copy the data into the robustification buffer */
 569                 yaffs_handle_chunk_wr_ok(dev, chunk, data, tags);
 570
 571         } while (write_ok != YAFFS_OK &&
 572                  (yaffs_wr_attempts == 0 || attempts <= yaffs_wr_attempts));
 573
 574         if (!write_ok)
 575                 chunk = -1;
 576
 577         if (attempts > 1) {
 578                 yaffs_trace(YAFFS_TRACE_ERROR,
 579                         "**>> yaffs write required %d attempts",
 580                         attempts);
 581                 dev->n_retried_writes += (attempts - 1);
 582         }
 583
 584         return chunk;
 585 }
 586
 587 /*
 588  * Block retiring for handling a broken block.
 589  */
 590
 591 static void yaffs_retire_block(struct yaffs_dev *dev, int flash_block)
 592 {
 593         struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
 594
 595         yaffs2_checkpt_invalidate(dev);
 596
 597         yaffs2_clear_oldest_dirty_seq(dev, bi);
 598
 599         if (yaffs_mark_bad(dev, flash_block) != YAFFS_OK) {
 600                 if (yaffs_erase_block(dev, flash_block) != YAFFS_OK) {
 601                         yaffs_trace(YAFFS_TRACE_ALWAYS,
 602                                 "yaffs: Failed to mark bad and erase block %d",
 603                                 flash_block);
 604                 } else {
 605                         struct yaffs_ext_tags tags;
 606                         int chunk_id =
 607                             flash_block * dev->param.chunks_per_block;
 608
 609                         u8 *buffer = yaffs_get_temp_buffer(dev);
 610
 611                         memset(buffer, 0xff, dev->data_bytes_per_chunk);
 612                         memset(&tags, 0, sizeof(tags));
 613                         tags.seq_number = YAFFS_SEQUENCE_BAD_BLOCK;
 614                         if (dev->tagger.write_chunk_tags_fn(dev, chunk_id -
 615                                                         dev->chunk_offset,
 616                                                         buffer,
 617                                                         &tags) != YAFFS_OK)
 618                                 yaffs_trace(YAFFS_TRACE_ALWAYS,
 619                                         "yaffs: Failed to write bad block marker to block %d",
 620                                         flash_block);
 621
 622                         yaffs_release_temp_buffer(dev, buffer);
 623                 }
 624         }
 625
 626         bi->block_state = YAFFS_BLOCK_STATE_DEAD;
 627         bi->gc_prioritise = 0;
 628         bi->needs_retiring = 0;
 629
 630         dev->n_retired_blocks++;
 631 }
 632
 633 /*---------------- Name handling functions ------------*/
 634
 635 static void yaffs_load_name_from_oh(struct yaffs_dev *dev, YCHAR *name,
 636                                     const YCHAR *oh_name, int buff_size)
 637 {
 638 #ifdef CONFIG_YAFFS_AUTO_UNICODE
 639         if (dev->param.auto_unicode) {
 640                 if (*oh_name) {
 641                         /* It is an ASCII name, do an ASCII to
 642                          * unicode conversion */
 643                         const char *ascii_oh_name = (const char *)oh_name;
 644                         int n = buff_size - 1;
 645                         while (n > 0 && *ascii_oh_name) {
 646                                 *name = *ascii_oh_name;
 647                                 name++;
 648                                 ascii_oh_name++;
 649                                 n--;
 650                         }
 651                 } else {
 652                         strncpy(name, oh_name + 1, buff_size - 1);
 653                 }
 654         } else {
 655 #else
 656         (void) dev;
 657         {
 658 #endif
 659                 strncpy(name, oh_name, buff_size - 1);
 660         }
 661 }
 662
 663 static void yaffs_load_oh_from_name(struct yaffs_dev *dev, YCHAR *oh_name,
 664                                     const YCHAR *name)
 665 {
 666 #ifdef CONFIG_YAFFS_AUTO_UNICODE
 667
 668         int is_ascii;
 669         const YCHAR *w;
 670
 671         if (dev->param.auto_unicode) {
 672
 673                 is_ascii = 1;
 674                 w = name;
 675
 676                 /* Figure out if the name will fit in ascii character set */
 677                 while (is_ascii && *w) {
 678                         if ((*w) & 0xff00)
 679                                 is_ascii = 0;
 680                         w++;
 681                 }
 682
 683                 if (is_ascii) {
 684                         /* It is an ASCII name, so convert unicode to ascii */
 685                         char *ascii_oh_name = (char *)oh_name;
 686                         int n = YAFFS_MAX_NAME_LENGTH - 1;
 687                         while (n > 0 && *name) {
 688                                 *ascii_oh_name = *name;
 689                                 name++;
 690                                 ascii_oh_name++;
 691                                 n--;
 692                         }
 693                 } else {
 694                         /* Unicode name, so save starting at the second YCHAR */
 695                         *oh_name = 0;
 696                         strncpy(oh_name + 1, name, YAFFS_MAX_NAME_LENGTH - 2);
 697                 }
 698         } else {
 699 #else
 700         dev = dev;
 701         {
 702 #endif
 703                 strncpy(oh_name, name, YAFFS_MAX_NAME_LENGTH - 1);
 704         }
 705 }
 706
 707 static u16 yaffs_calc_name_sum(const YCHAR *name)
 708 {
 709         u16 sum = 0;
 710         u16 i = 1;
 711
 712         if (!name)
 713                 return 0;
 714
 715         while ((*name) && i < (YAFFS_MAX_NAME_LENGTH / 2)) {
 716
 717                 /* 0x1f mask is case insensitive */
 718                 sum += ((*name) & 0x1f) * i;
 719                 i++;
 720                 name++;
 721         }
 722         return sum;
 723 }
 724
 725
 726 void yaffs_set_obj_name(struct yaffs_obj *obj, const YCHAR * name)
 727 {
 728         memset(obj->short_name, 0, sizeof(obj->short_name));
 729
 730         if (name && !name[0]) {
 731                 yaffs_fix_null_name(obj, obj->short_name,
 732                                 YAFFS_SHORT_NAME_LENGTH);
 733                 name = obj->short_name;
 734         } else if (name &&
 735                 strnlen(name, YAFFS_SHORT_NAME_LENGTH + 1) <=
 736                 YAFFS_SHORT_NAME_LENGTH)  {
 737                 strcpy(obj->short_name, name);
 738         }
 739
 740         obj->sum = yaffs_calc_name_sum(name);
 741 }
 742
 743 void yaffs_set_obj_name_from_oh(struct yaffs_obj *obj,
 744                                 const struct yaffs_obj_hdr *oh)
 745 {
 746 #ifdef CONFIG_YAFFS_AUTO_UNICODE
 747         YCHAR tmp_name[YAFFS_MAX_NAME_LENGTH + 1];
 748         memset(tmp_name, 0, sizeof(tmp_name));
 749         yaffs_load_name_from_oh(obj->my_dev, tmp_name, oh->name,
 750                                 YAFFS_MAX_NAME_LENGTH + 1);
 751         yaffs_set_obj_name(obj, tmp_name);
 752 #else
 753         yaffs_set_obj_name(obj, oh->name);
 754 #endif
 755 }
 756
 757 loff_t yaffs_max_file_size(struct yaffs_dev *dev)
 758 {
 759         if (sizeof(loff_t) < 8)
 760                 return YAFFS_MAX_FILE_SIZE_32;
 761         else
 762                 return ((loff_t) YAFFS_MAX_CHUNK_ID) * dev->data_bytes_per_chunk;
 763 }
 764
 765 /*-------------------- TNODES -------------------
 766
 767  * List of spare tnodes
 768  * The list is hooked together using the first pointer
 769  * in the tnode.
 770  */
 771
 772 struct yaffs_tnode *yaffs_get_tnode(struct yaffs_dev *dev)
 773 {
 774         struct yaffs_tnode *tn = yaffs_alloc_raw_tnode(dev);
 775
 776         if (tn) {
 777                 memset(tn, 0, dev->tnode_size);
 778                 dev->n_tnodes++;
 779         }
 780
 781         dev->checkpoint_blocks_required = 0;    /* force recalculation */
 782
 783         return tn;
 784 }
 785
 786 /* FreeTnode frees up a tnode and puts it back on the free list */
 787 static void yaffs_free_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
 788 {
 789         yaffs_free_raw_tnode(dev, tn);
 790         dev->n_tnodes--;
 791         dev->checkpoint_blocks_required = 0;    /* force recalculation */
 792 }
 793
 794 static void yaffs_deinit_tnodes_and_objs(struct yaffs_dev *dev)
 795 {
 796         yaffs_deinit_raw_tnodes_and_objs(dev);
 797         dev->n_obj = 0;
 798         dev->n_tnodes = 0;
 799 }
 800
 801 static void yaffs_load_tnode_0(struct yaffs_dev *dev, struct yaffs_tnode *tn,
 802                         unsigned pos, unsigned val)
 803 {
 804         u32 *map = (u32 *) tn;
 805         u32 bit_in_map;
 806         u32 bit_in_word;
 807         u32 word_in_map;
 808         u32 mask;
 809
 810         pos &= YAFFS_TNODES_LEVEL0_MASK;
 811         val >>= dev->chunk_grp_bits;
 812
 813         bit_in_map = pos * dev->tnode_width;
 814         word_in_map = bit_in_map / 32;
 815         bit_in_word = bit_in_map & (32 - 1);
 816
 817         mask = dev->tnode_mask << bit_in_word;
 818
 819         map[word_in_map] &= ~mask;
 820         map[word_in_map] |= (mask & (val << bit_in_word));
 821
 822         if (dev->tnode_width > (32 - bit_in_word)) {
 823                 bit_in_word = (32 - bit_in_word);
 824                 word_in_map++;
 825                 mask =
 826                     dev->tnode_mask >> bit_in_word;
 827                 map[word_in_map] &= ~mask;
 828                 map[word_in_map] |= (mask & (val >> bit_in_word));
 829         }
 830 }
 831
 832 u32 yaffs_get_group_base(struct yaffs_dev *dev, struct yaffs_tnode *tn,
 833                          unsigned pos)
 834 {
 835         u32 *map = (u32 *) tn;
 836         u32 bit_in_map;
 837         u32 bit_in_word;
 838         u32 word_in_map;
 839         u32 val;
 840
 841         pos &= YAFFS_TNODES_LEVEL0_MASK;
 842
 843         bit_in_map = pos * dev->tnode_width;
 844         word_in_map = bit_in_map / 32;
 845         bit_in_word = bit_in_map & (32 - 1);
 846
 847         val = map[word_in_map] >> bit_in_word;
 848
 849         if (dev->tnode_width > (32 - bit_in_word)) {
 850                 bit_in_word = (32 - bit_in_word);
 851                 word_in_map++;
 852                 val |= (map[word_in_map] << bit_in_word);
 853         }
 854
 855         val &= dev->tnode_mask;
 856         val <<= dev->chunk_grp_bits;
 857
 858         return val;
 859 }
 860
 861 /* ------------------- End of individual tnode manipulation -----------------*/
 862
 863 /* ---------Functions to manipulate the look-up tree (made up of tnodes) ------
 864  * The look up tree is represented by the top tnode and the number of top_level
 865  * in the tree. 0 means only the level 0 tnode is in the tree.
 866  */
 867
 868 /* FindLevel0Tnode finds the level 0 tnode, if one exists. */
 869 struct yaffs_tnode *yaffs_find_tnode_0(struct yaffs_dev *dev,
 870                                        struct yaffs_file_var *file_struct,
 871                                        u32 chunk_id)
 872 {
 873         struct yaffs_tnode *tn = file_struct->top;
 874         u32 i;
 875         int required_depth;
 876         int level = file_struct->top_level;
 877
 878         (void) dev;
 879
 880         /* Check sane level and chunk Id */
 881         if (level < 0 || level > YAFFS_TNODES_MAX_LEVEL)
 882                 return NULL;
 883
 884         if (chunk_id > YAFFS_MAX_CHUNK_ID)
 885                 return NULL;
 886
 887         /* First check we're tall enough (ie enough top_level) */
 888
 889         i = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
 890         required_depth = 0;
 891         while (i) {
 892                 i >>= YAFFS_TNODES_INTERNAL_BITS;
 893                 required_depth++;
 894         }
 895
 896         if (required_depth > file_struct->top_level)
 897                 return NULL;    /* Not tall enough, so we can't find it */
 898
 899         /* Traverse down to level 0 */
 900         while (level > 0 && tn) {
 901                 tn = tn->internal[(chunk_id >>
 902                                    (YAFFS_TNODES_LEVEL0_BITS +
 903                                     (level - 1) *
 904                                     YAFFS_TNODES_INTERNAL_BITS)) &
 905                                   YAFFS_TNODES_INTERNAL_MASK];
 906                 level--;
 907         }
 908
 909         return tn;
 910 }
 911
 912 /* add_find_tnode_0 finds the level 0 tnode if it exists,
 913  * otherwise first expands the tree.
 914  * This happens in two steps:
 915  *  1. If the tree isn't tall enough, then make it taller.
 916  *  2. Scan down the tree towards the level 0 tnode adding tnodes if required.
 917  *
 918  * Used when modifying the tree.
 919  *
 920  *  If the tn argument is NULL, then a fresh tnode will be added otherwise the
 921  *  specified tn will be plugged into the ttree.
 922  */
 923
 924 struct yaffs_tnode *yaffs_add_find_tnode_0(struct yaffs_dev *dev,
 925                                            struct yaffs_file_var *file_struct,
 926                                            u32 chunk_id,
 927                                            struct yaffs_tnode *passed_tn)
 928 {
 929         int required_depth;
 930         int i;
 931         int l;
 932         struct yaffs_tnode *tn;
 933         u32 x;
 934
 935         /* Check sane level and page Id */
 936         if (file_struct->top_level < 0 ||
 937             file_struct->top_level > YAFFS_TNODES_MAX_LEVEL)
 938                 return NULL;
 939
 940         if (chunk_id > YAFFS_MAX_CHUNK_ID)
 941                 return NULL;
 942
 943         /* First check we're tall enough (ie enough top_level) */
 944
 945         x = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
 946         required_depth = 0;
 947         while (x) {
 948                 x >>= YAFFS_TNODES_INTERNAL_BITS;
 949                 required_depth++;
 950         }
 951
 952         if (required_depth > file_struct->top_level) {
 953                 /* Not tall enough, gotta make the tree taller */
 954                 for (i = file_struct->top_level; i < required_depth; i++) {
 955
 956                         tn = yaffs_get_tnode(dev);
 957
 958                         if (tn) {
 959                                 tn->internal[0] = file_struct->top;
 960                                 file_struct->top = tn;
 961                                 file_struct->top_level++;
 962                         } else {
 963                                 yaffs_trace(YAFFS_TRACE_ERROR,
 964                                         "yaffs: no more tnodes");
 965                                 return NULL;
 966                         }
 967                 }
 968         }
 969
 970         /* Traverse down to level 0, adding anything we need */
 971
 972         l = file_struct->top_level;
 973         tn = file_struct->top;
 974
 975         if (l > 0) {
 976                 while (l > 0 && tn) {
 977                         x = (chunk_id >>
 978                              (YAFFS_TNODES_LEVEL0_BITS +
 979                               (l - 1) * YAFFS_TNODES_INTERNAL_BITS)) &
 980                             YAFFS_TNODES_INTERNAL_MASK;
 981
 982                         if ((l > 1) && !tn->internal[x]) {
 983                                 /* Add missing non-level-zero tnode */
 984                                 tn->internal[x] = yaffs_get_tnode(dev);
 985                                 if (!tn->internal[x])
 986                                         return NULL;
 987                         } else if (l == 1) {
 988                                 /* Looking from level 1 at level 0 */
 989                                 if (passed_tn) {
 990                                         /* If we already have one, release it */
 991                                         if (tn->internal[x])
 992                                                 yaffs_free_tnode(dev,
 993                                                         tn->internal[x]);
 994                                         tn->internal[x] = passed_tn;
 995
 996                                 } else if (!tn->internal[x]) {
 997                                         /* Don't have one, none passed in */
 998                                         tn->internal[x] = yaffs_get_tnode(dev);
 999                                         if (!tn->internal[x])
1000                                                 return NULL;
1001                                 }
1002                         }
1003
1004                         tn = tn->internal[x];
1005                         l--;
1006                 }
1007         } else {
1008                 /* top is level 0 */
1009                 if (passed_tn) {
1010                         memcpy(tn, passed_tn,
1011                                (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8);
1012                         yaffs_free_tnode(dev, passed_tn);
1013                 }
1014         }
1015
1016         return tn;
1017 }
1018
1019 static int yaffs_tags_match(const struct yaffs_ext_tags *tags, int obj_id,
1020                             int chunk_obj)
1021 {
1022         return (tags->chunk_id == (u32)chunk_obj &&
1023                 tags->obj_id == (u32)obj_id &&
1024                 !tags->is_deleted) ? 1 : 0;
1025
1026 }
1027
1028 static int yaffs_find_chunk_in_group(struct yaffs_dev *dev, int the_chunk,
1029                                         struct yaffs_ext_tags *tags, int obj_id,
1030                                         int inode_chunk)
1031 {
1032         int j;
1033
1034         for (j = 0; the_chunk && j < dev->chunk_grp_size; j++) {
1035                 if (yaffs_check_chunk_bit
1036                     (dev, the_chunk / dev->param.chunks_per_block,
1037                      the_chunk % dev->param.chunks_per_block)) {
1038
1039                         if (dev->chunk_grp_size == 1)
1040                                 return the_chunk;
1041                         else {
1042                                 yaffs_rd_chunk_tags_nand(dev, the_chunk, NULL,
1043                                                          tags);
1044                                 if (yaffs_tags_match(tags,
1045                                                         obj_id, inode_chunk)) {
1046                                         /* found it; */
1047                                         return the_chunk;
1048                                 }
1049                         }
1050                 }
1051                 the_chunk++;
1052         }
1053         return -1;
1054 }
1055
1056 int yaffs_find_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
1057                                     struct yaffs_ext_tags *tags)
1058 {
1059         /*Get the Tnode, then get the level 0 offset chunk offset */
1060         struct yaffs_tnode *tn;
1061         int the_chunk = -1;
1062         struct yaffs_ext_tags local_tags;
1063         int ret_val = -1;
1064         struct yaffs_dev *dev = in->my_dev;
1065
1066         if (!tags) {
1067                 /* Passed a NULL, so use our own tags space */
1068                 tags = &local_tags;
1069         }
1070
1071         tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
1072
1073         if (!tn)
1074                 return ret_val;
1075
1076         the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
1077
1078         ret_val = yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
1079                                               inode_chunk);
1080         return ret_val;
1081 }
1082
1083 static int yaffs_find_del_file_chunk(struct yaffs_obj *in, int inode_chunk,
1084                                      struct yaffs_ext_tags *tags)
1085 {
1086         /* Get the Tnode, then get the level 0 offset chunk offset */
1087         struct yaffs_tnode *tn;
1088         int the_chunk = -1;
1089         struct yaffs_ext_tags local_tags;
1090         struct yaffs_dev *dev = in->my_dev;
1091         int ret_val = -1;
1092
1093         if (!tags) {
1094                 /* Passed a NULL, so use our own tags space */
1095                 tags = &local_tags;
1096         }
1097
1098         tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
1099
1100         if (!tn)
1101                 return ret_val;
1102
1103         the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
1104
1105         ret_val = yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
1106                                               inode_chunk);
1107
1108         /* Delete the entry in the filestructure (if found) */
1109         if (ret_val != -1)
1110                 yaffs_load_tnode_0(dev, tn, inode_chunk, 0);
1111
1112         return ret_val;
1113 }
1114
1115 int yaffs_put_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
1116                             int nand_chunk, int in_scan)
1117 {
1118         /* NB in_scan is zero unless scanning.
1119          * For forward scanning, in_scan is > 0;
1120          * for backward scanning in_scan is < 0
1121          *
1122          * nand_chunk = 0 is a dummy insert to make sure the tnodes are there.
1123          */
1124
1125         struct yaffs_tnode *tn;
1126         struct yaffs_dev *dev = in->my_dev;
1127         int existing_cunk;
1128         struct yaffs_ext_tags existing_tags;
1129         struct yaffs_ext_tags new_tags;
1130         unsigned existing_serial, new_serial;
1131
1132         if (in->variant_type != YAFFS_OBJECT_TYPE_FILE) {
1133                 /* Just ignore an attempt at putting a chunk into a non-file
1134                  * during scanning.
1135                  * If it is not during Scanning then something went wrong!
1136                  */
1137                 if (!in_scan) {
1138                         yaffs_trace(YAFFS_TRACE_ERROR,
1139                                 "yaffs tragedy:attempt to put data chunk into a non-file"
1140                                 );
1141                         BUG();
1142                 }
1143
1144                 yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
1145                 return YAFFS_OK;
1146         }
1147
1148         tn = yaffs_add_find_tnode_0(dev,
1149                                     &in->variant.file_variant,
1150                                     inode_chunk, NULL);
1151         if (!tn)
1152                 return YAFFS_FAIL;
1153
1154         if (!nand_chunk)
1155                 /* Dummy insert, bail now */
1156                 return YAFFS_OK;
1157
1158         existing_cunk = yaffs_get_group_base(dev, tn, inode_chunk);
1159
1160         if (in_scan != 0) {
1161                 /* If we're scanning then we need to test for duplicates
1162                  * NB This does not need to be efficient since it should only
1163                  * happen when the power fails during a write, then only one
1164                  * chunk should ever be affected.
1165                  *
1166                  * Correction for YAFFS2: This could happen quite a lot and we
1167                  * need to think about efficiency! TODO
1168                  * Update: For backward scanning we don't need to re-read tags
1169                  * so this is quite cheap.
1170                  */
1171
1172                 if (existing_cunk > 0) {
1173                         /* NB Right now existing chunk will not be real
1174                          * chunk_id if the chunk group size > 1
1175                          * thus we have to do a FindChunkInFile to get the
1176                          * real chunk id.
1177                          *
1178                          * We have a duplicate now we need to decide which
1179                          * one to use:
1180                          *
1181                          * Backwards scanning YAFFS2: The old one is what
1182                          * we use, dump the new one.
1183                          * YAFFS1: Get both sets of tags and compare serial
1184                          * numbers.
1185                          */
1186
1187                         if (in_scan > 0) {
1188                                 /* Only do this for forward scanning */
1189                                 yaffs_rd_chunk_tags_nand(dev,
1190                                                          nand_chunk,
1191                                                          NULL, &new_tags);
1192
1193                                 /* Do a proper find */
1194                                 existing_cunk =
1195                                     yaffs_find_chunk_in_file(in, inode_chunk,
1196                                                              &existing_tags);
1197                         }
1198
1199                         if (existing_cunk <= 0) {
1200                                 /*Hoosterman - how did this happen? */
1201
1202                                 yaffs_trace(YAFFS_TRACE_ERROR,
1203                                         "yaffs tragedy: existing chunk < 0 in scan"
1204                                         );
1205
1206                         }
1207
1208                         /* NB The deleted flags should be false, otherwise
1209                          * the chunks will not be loaded during a scan
1210                          */
1211
1212                         if (in_scan > 0) {
1213                                 new_serial = new_tags.serial_number;
1214                                 existing_serial = existing_tags.serial_number;
1215                         }
1216
1217                         if ((in_scan > 0) &&
1218                             (existing_cunk <= 0 ||
1219                              ((existing_serial + 1) & 3) == new_serial)) {
1220                                 /* Forward scanning.
1221                                  * Use new
1222                                  * Delete the old one and drop through to
1223                                  * update the tnode
1224                                  */
1225                                 yaffs_chunk_del(dev, existing_cunk, 1,
1226                                                 __LINE__);
1227                         } else {
1228                                 /* Backward scanning or we want to use the
1229                                  * existing one
1230                                  * Delete the new one and return early so that
1231                                  * the tnode isn't changed
1232                                  */
1233                                 yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
1234                                 return YAFFS_OK;
1235                         }
1236                 }
1237
1238         }
1239
1240         if (existing_cunk == 0)
1241                 in->n_data_chunks++;
1242
1243         yaffs_load_tnode_0(dev, tn, inode_chunk, nand_chunk);
1244
1245         return YAFFS_OK;
1246 }
1247
1248 static void yaffs_soft_del_chunk(struct yaffs_dev *dev, int chunk)
1249 {
1250         struct yaffs_block_info *the_block;
1251         unsigned block_no;
1252
1253         yaffs_trace(YAFFS_TRACE_DELETION, "soft delete chunk %d", chunk);
1254
1255         block_no = chunk / dev->param.chunks_per_block;
1256         the_block = yaffs_get_block_info(dev, block_no);
1257         if (the_block) {
1258                 the_block->soft_del_pages++;
1259                 dev->n_free_chunks++;
1260                 yaffs2_update_oldest_dirty_seq(dev, block_no, the_block);
1261         }
1262 }
1263
1264 /* SoftDeleteWorker scans backwards through the tnode tree and soft deletes all
1265  * the chunks in the file.
1266  * All soft deleting does is increment the block's softdelete count and pulls
1267  * the chunk out of the tnode.
1268  * Thus, essentially this is the same as DeleteWorker except that the chunks
1269  * are soft deleted.
1270  */
1271
1272 static int yaffs_soft_del_worker(struct yaffs_obj *in, struct yaffs_tnode *tn,
1273                                  u32 level, int chunk_offset)
1274 {
1275         int i;
1276         int the_chunk;
1277         int all_done = 1;
1278         struct yaffs_dev *dev = in->my_dev;
1279
1280         if (!tn)
1281                 return 1;
1282
1283         if (level > 0) {
1284                 for (i = YAFFS_NTNODES_INTERNAL - 1;
1285                         all_done && i >= 0;
1286                         i--) {
1287                         if (tn->internal[i]) {
1288                                 all_done =
1289                                     yaffs_soft_del_worker(in,
1290                                         tn->internal[i],
1291                                         level - 1,
1292                                         (chunk_offset <<
1293                                         YAFFS_TNODES_INTERNAL_BITS)
1294                                         + i);
1295                                 if (all_done) {
1296                                         yaffs_free_tnode(dev,
1297                                                 tn->internal[i]);
1298                                         tn->internal[i] = NULL;
1299                                 } else {
1300                                         /* Can this happen? */
1301                                 }
1302                         }
1303                 }
1304                 return (all_done) ? 1 : 0;
1305         }
1306
1307         /* level 0 */
1308          for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0; i--) {
1309                 the_chunk = yaffs_get_group_base(dev, tn, i);
1310                 if (the_chunk) {
1311                         yaffs_soft_del_chunk(dev, the_chunk);
1312                         yaffs_load_tnode_0(dev, tn, i, 0);
1313                 }
1314         }
1315         return 1;
1316 }
1317
1318 static void yaffs_remove_obj_from_dir(struct yaffs_obj *obj)
1319 {
1320         struct yaffs_dev *dev = obj->my_dev;
1321         struct yaffs_obj *parent;
1322
1323         yaffs_verify_obj_in_dir(obj);
1324         parent = obj->parent;
1325
1326         yaffs_verify_dir(parent);
1327
1328         if (dev && dev->param.remove_obj_fn)
1329                 dev->param.remove_obj_fn(obj);
1330
1331         list_del_init(&obj->siblings);
1332         obj->parent = NULL;
1333
1334         yaffs_verify_dir(parent);
1335 }
1336
1337 void yaffs_add_obj_to_dir(struct yaffs_obj *directory, struct yaffs_obj *obj)
1338 {
1339         if (!directory) {
1340                 yaffs_trace(YAFFS_TRACE_ALWAYS,
1341                         "tragedy: Trying to add an object to a null pointer directory"
1342                         );
1343                 BUG();
1344                 return;
1345         }
1346         if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
1347                 yaffs_trace(YAFFS_TRACE_ALWAYS,
1348                         "tragedy: Trying to add an object to a non-directory"
1349                         );
1350                 BUG();
1351         }
1352
1353         if (obj->siblings.prev == NULL) {
1354                 /* Not initialised */
1355                 BUG();
1356         }
1357
1358         yaffs_verify_dir(directory);
1359
1360         yaffs_remove_obj_from_dir(obj);
1361
1362         /* Now add it */
1363         list_add(&obj->siblings, &directory->variant.dir_variant.children);
1364         obj->parent = directory;
1365
1366         if (directory == obj->my_dev->unlinked_dir
1367             || directory == obj->my_dev->del_dir) {
1368                 obj->unlinked = 1;
1369                 obj->my_dev->n_unlinked_files++;
1370                 obj->rename_allowed = 0;
1371         }
1372
1373         yaffs_verify_dir(directory);
1374         yaffs_verify_obj_in_dir(obj);
1375 }
1376
1377 static int yaffs_change_obj_name(struct yaffs_obj *obj,
1378                                  struct yaffs_obj *new_dir,
1379                                  const YCHAR *new_name, int force, int shadows)
1380 {
1381         int unlink_op;
1382         int del_op;
1383         struct yaffs_obj *existing_target;
1384
1385         if (new_dir == NULL)
1386                 new_dir = obj->parent;  /* use the old directory */
1387
1388         if (new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
1389                 yaffs_trace(YAFFS_TRACE_ALWAYS,
1390                         "tragedy: yaffs_change_obj_name: new_dir is not a directory"
1391                         );
1392                 BUG();
1393         }
1394
1395         unlink_op = (new_dir == obj->my_dev->unlinked_dir);
1396         del_op = (new_dir == obj->my_dev->del_dir);
1397
1398         existing_target = yaffs_find_by_name(new_dir, new_name);
1399
1400         /* If the object is a file going into the unlinked directory,
1401          *   then it is OK to just stuff it in since duplicate names are OK.
1402          *   else only proceed if the new name does not exist and we're putting
1403          *   it into a directory.
1404          */
1405         if (!(unlink_op || del_op || force ||
1406               shadows > 0 || !existing_target) ||
1407               new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
1408                 return YAFFS_FAIL;
1409
1410         yaffs_set_obj_name(obj, new_name);
1411         obj->dirty = 1;
1412         yaffs_add_obj_to_dir(new_dir, obj);
1413
1414         if (unlink_op)
1415                 obj->unlinked = 1;
1416
1417         /* If it is a deletion then we mark it as a shrink for gc  */
1418         if (yaffs_update_oh(obj, new_name, 0, del_op, shadows, NULL) >= 0)
1419                 return YAFFS_OK;
1420
1421         return YAFFS_FAIL;
1422 }
1423
1424
1425 static void yaffs_unhash_obj(struct yaffs_obj *obj)
1426 {
1427         int bucket;
1428         struct yaffs_dev *dev = obj->my_dev;
1429
1430         /* If it is still linked into the bucket list, free from the list */
1431         if (!list_empty(&obj->hash_link)) {
1432                 list_del_init(&obj->hash_link);
1433                 bucket = yaffs_hash_fn(obj->obj_id);
1434                 dev->obj_bucket[bucket].count--;
1435         }
1436 }
1437
1438 /*  FreeObject frees up a Object and puts it back on the free list */
1439 static void yaffs_free_obj(struct yaffs_obj *obj)
1440 {
1441         struct yaffs_dev *dev;
1442
1443         if (!obj) {
1444                 BUG();
1445                 return;
1446         }
1447         dev = obj->my_dev;
1448         yaffs_trace(YAFFS_TRACE_OS, "FreeObject %p inode %p",
1449                 obj, obj->my_inode);
1450         if (obj->parent)
1451                 BUG();
1452         if (!list_empty(&obj->siblings))
1453                 BUG();
1454
1455         if (obj->my_inode) {
1456                 /* We're still hooked up to a cached inode.
1457                  * Don't delete now, but mark for later deletion
1458                  */
1459                 obj->defered_free = 1;
1460                 return;
1461         }
1462
1463         yaffs_unhash_obj(obj);
1464
1465         yaffs_free_raw_obj(dev, obj);
1466         dev->n_obj--;
1467         dev->checkpoint_blocks_required = 0;    /* force recalculation */
1468 }
1469
1470 void yaffs_handle_defered_free(struct yaffs_obj *obj)
1471 {
1472         if (obj->defered_free)
1473                 yaffs_free_obj(obj);
1474 }
1475
1476 static int yaffs_generic_obj_del(struct yaffs_obj *in)
1477 {
1478         /* Iinvalidate the file's data in the cache, without flushing. */
1479         yaffs_invalidate_file_cache(in);
1480
1481         if (in->my_dev->param.is_yaffs2 && in->parent != in->my_dev->del_dir) {
1482                 /* Move to unlinked directory so we have a deletion record */
1483                 yaffs_change_obj_name(in, in->my_dev->del_dir, _Y("deleted"), 0,
1484                                       0);
1485         }
1486
1487         yaffs_remove_obj_from_dir(in);
1488         yaffs_chunk_del(in->my_dev, in->hdr_chunk, 1, __LINE__);
1489         in->hdr_chunk = 0;
1490
1491         yaffs_free_obj(in);
1492         return YAFFS_OK;
1493
1494 }
1495
1496 static void yaffs_soft_del_file(struct yaffs_obj *obj)
1497 {
1498         if (!obj->deleted ||
1499             obj->variant_type != YAFFS_OBJECT_TYPE_FILE ||
1500             obj->soft_del)
1501                 return;
1502
1503         if (obj->n_data_chunks <= 0) {
1504                 /* Empty file with no duplicate object headers,
1505                  * just delete it immediately */
1506                 yaffs_free_tnode(obj->my_dev, obj->variant.file_variant.top);
1507                 obj->variant.file_variant.top = NULL;
1508                 yaffs_trace(YAFFS_TRACE_TRACING,
1509                         "yaffs: Deleting empty file %d",
1510                         obj->obj_id);
1511                 yaffs_generic_obj_del(obj);
1512         } else {
1513                 yaffs_soft_del_worker(obj,
1514                                       obj->variant.file_variant.top,
1515                                       obj->variant.
1516                                       file_variant.top_level, 0);
1517                 obj->soft_del = 1;
1518         }
1519 }
1520
1521 /* Pruning removes any part of the file structure tree that is beyond the
1522  * bounds of the file (ie that does not point to chunks).
1523  *
1524  * A file should only get pruned when its size is reduced.
1525  *
1526  * Before pruning, the chunks must be pulled from the tree and the
1527  * level 0 tnode entries must be zeroed out.
1528  * Could also use this for file deletion, but that's probably better handled
1529  * by a special case.
1530  *
1531  * This function is recursive. For levels > 0 the function is called again on
1532  * any sub-tree. For level == 0 we just check if the sub-tree has data.
1533  * If there is no data in a subtree then it is pruned.
1534  */
1535
1536 static struct yaffs_tnode *yaffs_prune_worker(struct yaffs_dev *dev,
1537                                               struct yaffs_tnode *tn, u32 level,
1538                                               int del0)
1539 {
1540         int i;
1541         int has_data;
1542
1543         if (!tn)
1544                 return tn;
1545
1546         has_data = 0;
1547
1548         if (level > 0) {
1549                 for (i = 0; i < YAFFS_NTNODES_INTERNAL; i++) {
1550                         if (tn->internal[i]) {
1551                                 tn->internal[i] =
1552                                     yaffs_prune_worker(dev,
1553                                                 tn->internal[i],
1554                                                 level - 1,
1555                                                 (i == 0) ? del0 : 1);
1556                         }
1557
1558                         if (tn->internal[i])
1559                                 has_data++;
1560                 }
1561         } else {
1562                 int tnode_size_u32 = dev->tnode_size / sizeof(u32);
1563                 u32 *map = (u32 *) tn;
1564
1565                 for (i = 0; !has_data && i < tnode_size_u32; i++) {
1566                         if (map[i])
1567                                 has_data++;
1568                 }
1569         }
1570
1571         if (has_data == 0 && del0) {
1572                 /* Free and return NULL */
1573                 yaffs_free_tnode(dev, tn);
1574                 tn = NULL;
1575         }
1576         return tn;
1577 }
1578
1579 static int yaffs_prune_tree(struct yaffs_dev *dev,
1580                             struct yaffs_file_var *file_struct)
1581 {
1582         int i;
1583         int has_data;
1584         int done = 0;
1585         struct yaffs_tnode *tn;
1586
1587         if (file_struct->top_level < 1)
1588                 return YAFFS_OK;
1589
1590         file_struct->top =
1591            yaffs_prune_worker(dev, file_struct->top, file_struct->top_level, 0);
1592
1593         /* Now we have a tree with all the non-zero branches NULL but
1594          * the height is the same as it was.
1595          * Let's see if we can trim internal tnodes to shorten the tree.
1596          * We can do this if only the 0th element in the tnode is in use
1597          * (ie all the non-zero are NULL)
1598          */
1599
1600         while (file_struct->top_level && !done) {
1601                 tn = file_struct->top;
1602
1603                 has_data = 0;
1604                 for (i = 1; i < YAFFS_NTNODES_INTERNAL; i++) {
1605                         if (tn->internal[i])
1606                                 has_data++;
1607                 }
1608
1609                 if (!has_data) {
1610                         file_struct->top = tn->internal[0];
1611                         file_struct->top_level--;
1612                         yaffs_free_tnode(dev, tn);
1613                 } else {
1614                         done = 1;
1615                 }
1616         }
1617
1618         return YAFFS_OK;
1619 }
1620
1621 /*-------------------- End of File Structure functions.-------------------*/
1622
1623 /* alloc_empty_obj gets us a clean Object.*/
1624 static struct yaffs_obj *yaffs_alloc_empty_obj(struct yaffs_dev *dev)
1625 {
1626         struct yaffs_obj *obj = yaffs_alloc_raw_obj(dev);
1627
1628         if (!obj)
1629                 return obj;
1630
1631         dev->n_obj++;
1632
1633         /* Now sweeten it up... */
1634
1635         memset(obj, 0, sizeof(struct yaffs_obj));
1636         obj->being_created = 1;
1637
1638         obj->my_dev = dev;
1639         obj->hdr_chunk = 0;
1640         obj->variant_type = YAFFS_OBJECT_TYPE_UNKNOWN;
1641         INIT_LIST_HEAD(&(obj->hard_links));
1642         INIT_LIST_HEAD(&(obj->hash_link));
1643         INIT_LIST_HEAD(&obj->siblings);
1644
1645         /* Now make the directory sane */
1646         if (dev->root_dir) {
1647                 obj->parent = dev->root_dir;
1648                 list_add(&(obj->siblings),
1649                          &dev->root_dir->variant.dir_variant.children);
1650         }
1651
1652         /* Add it to the lost and found directory.
1653          * NB Can't put root or lost-n-found in lost-n-found so
1654          * check if lost-n-found exists first
1655          */
1656         if (dev->lost_n_found)
1657                 yaffs_add_obj_to_dir(dev->lost_n_found, obj);
1658
1659         obj->being_created = 0;
1660
1661         dev->checkpoint_blocks_required = 0;    /* force recalculation */
1662
1663         return obj;
1664 }
1665
1666 static int yaffs_find_nice_bucket(struct yaffs_dev *dev)
1667 {
1668         int i;
1669         int l = 999;
1670         int lowest = 999999;
1671
1672         /* Search for the shortest list or one that
1673          * isn't too long.
1674          */
1675
1676         for (i = 0; i < 10 && lowest > 4; i++) {
1677                 dev->bucket_finder++;
1678                 dev->bucket_finder %= YAFFS_NOBJECT_BUCKETS;
1679                 if (dev->obj_bucket[dev->bucket_finder].count < lowest) {
1680                         lowest = dev->obj_bucket[dev->bucket_finder].count;
1681                         l = dev->bucket_finder;
1682                 }
1683         }
1684
1685         return l;
1686 }
1687
1688 static int yaffs_new_obj_id(struct yaffs_dev *dev)
1689 {
1690         int bucket = yaffs_find_nice_bucket(dev);
1691         int found = 0;
1692         struct list_head *i;
1693         u32 n = (u32) bucket;
1694
1695         /*
1696          * Now find an object value that has not already been taken
1697          * by scanning the list, incrementing each time by number of buckets.
1698          */
1699         while (!found) {
1700                 found = 1;
1701                 n += YAFFS_NOBJECT_BUCKETS;
1702                 list_for_each(i, &dev->obj_bucket[bucket].list) {
1703                         /* Check if this value is already taken. */
1704                         if (i && list_entry(i, struct yaffs_obj,
1705                                             hash_link)->obj_id == n)
1706                                 found = 0;
1707                 }
1708         }
1709         return n;
1710 }
1711
1712 static void yaffs_hash_obj(struct yaffs_obj *in)
1713 {
1714         int bucket = yaffs_hash_fn(in->obj_id);
1715         struct yaffs_dev *dev = in->my_dev;
1716
1717         list_add(&in->hash_link, &dev->obj_bucket[bucket].list);
1718         dev->obj_bucket[bucket].count++;
1719 }
1720
1721 struct yaffs_obj *yaffs_find_by_number(struct yaffs_dev *dev, u32 number)
1722 {
1723         int bucket = yaffs_hash_fn(number);
1724         struct list_head *i;
1725         struct yaffs_obj *in;
1726
1727         list_for_each(i, &dev->obj_bucket[bucket].list) {
1728                 /* Look if it is in the list */
1729                 in = list_entry(i, struct yaffs_obj, hash_link);
1730                 if (in->obj_id == number) {
1731                         /* Don't show if it is defered free */
1732                         if (in->defered_free)
1733                                 return NULL;
1734                         return in;
1735                 }
1736         }
1737
1738         return NULL;
1739 }
1740
1741 static struct yaffs_obj *yaffs_new_obj(struct yaffs_dev *dev, int number,
1742                                 enum yaffs_obj_type type)
1743 {
1744         struct yaffs_obj *the_obj = NULL;
1745         struct yaffs_tnode *tn = NULL;
1746
1747         if (number < 0)
1748                 number = yaffs_new_obj_id(dev);
1749
1750         if (type == YAFFS_OBJECT_TYPE_FILE) {
1751                 tn = yaffs_get_tnode(dev);
1752                 if (!tn)
1753                         return NULL;
1754         }
1755
1756         the_obj = yaffs_alloc_empty_obj(dev);
1757         if (!the_obj) {
1758                 if (tn)
1759                         yaffs_free_tnode(dev, tn);
1760                 return NULL;
1761         }
1762
1763         the_obj->fake = 0;
1764         the_obj->rename_allowed = 1;
1765         the_obj->unlink_allowed = 1;
1766         the_obj->obj_id = number;
1767         yaffs_hash_obj(the_obj);
1768         the_obj->variant_type = type;
1769         yaffs_load_current_time(the_obj, 1, 1);
1770
1771         switch (type) {
1772         case YAFFS_OBJECT_TYPE_FILE:
1773                 the_obj->variant.file_variant.file_size = 0;
1774                 the_obj->variant.file_variant.stored_size = 0;
1775                 the_obj->variant.file_variant.shrink_size =
1776                                                 yaffs_max_file_size(dev);
1777                 the_obj->variant.file_variant.top_level = 0;
1778                 the_obj->variant.file_variant.top = tn;
1779                 break;
1780         case YAFFS_OBJECT_TYPE_DIRECTORY:
1781                 INIT_LIST_HEAD(&the_obj->variant.dir_variant.children);
1782                 INIT_LIST_HEAD(&the_obj->variant.dir_variant.dirty);
1783                 break;
1784         case YAFFS_OBJECT_TYPE_SYMLINK:
1785         case YAFFS_OBJECT_TYPE_HARDLINK:
1786         case YAFFS_OBJECT_TYPE_SPECIAL:
1787                 /* No action required */
1788                 break;
1789         case YAFFS_OBJECT_TYPE_UNKNOWN:
1790                 /* todo this should not happen */
1791                 break;
1792         }
1793         return the_obj;
1794 }
1795
1796 static struct yaffs_obj *yaffs_create_fake_dir(struct yaffs_dev *dev,
1797                                                int number, u32 mode)
1798 {
1799
1800         struct yaffs_obj *obj =
1801             yaffs_new_obj(dev, number, YAFFS_OBJECT_TYPE_DIRECTORY);
1802
1803         if (!obj)
1804                 return NULL;
1805
1806         obj->fake = 1;  /* it is fake so it might not use NAND */
1807         obj->rename_allowed = 0;
1808         obj->unlink_allowed = 0;
1809         obj->deleted = 0;
1810         obj->unlinked = 0;
1811         obj->yst_mode = mode;
1812         obj->my_dev = dev;
1813         obj->hdr_chunk = 0;     /* Not a valid chunk. */
1814         return obj;
1815
1816 }
1817
1818
1819 static void yaffs_init_tnodes_and_objs(struct yaffs_dev *dev)
1820 {
1821         int i;
1822
1823         dev->n_obj = 0;
1824         dev->n_tnodes = 0;
1825         yaffs_init_raw_tnodes_and_objs(dev);
1826
1827         for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
1828                 INIT_LIST_HEAD(&dev->obj_bucket[i].list);
1829                 dev->obj_bucket[i].count = 0;
1830         }
1831 }
1832
1833 struct yaffs_obj *yaffs_find_or_create_by_number(struct yaffs_dev *dev,
1834                                                  int number,
1835                                                  enum yaffs_obj_type type)
1836 {
1837         struct yaffs_obj *the_obj = NULL;
1838
1839         if (number > 0)
1840                 the_obj = yaffs_find_by_number(dev, number);
1841
1842         if (!the_obj)
1843                 the_obj = yaffs_new_obj(dev, number, type);
1844
1845         return the_obj;
1846
1847 }
1848
1849 YCHAR *yaffs_clone_str(const YCHAR *str)
1850 {
1851         YCHAR *new_str = NULL;
1852         int len;
1853
1854         if (!str)
1855                 str = _Y("");
1856
1857         len = strnlen(str, YAFFS_MAX_ALIAS_LENGTH);
1858         new_str = kmalloc((len + 1) * sizeof(YCHAR), GFP_NOFS);
1859         if (new_str) {
1860                 strncpy(new_str, str, len);
1861                 new_str[len] = 0;
1862         }
1863         return new_str;
1864
1865 }
1866 /*
1867  *yaffs_update_parent() handles fixing a directories mtime and ctime when a new
1868  * link (ie. name) is created or deleted in the directory.
1869  *
1870  * ie.
1871  *   create dir/a : update dir's mtime/ctime
1872  *   rm dir/a:   update dir's mtime/ctime
1873  *   modify dir/a: don't update dir's mtimme/ctime
1874  *
1875  * This can be handled immediately or defered. Defering helps reduce the number
1876  * of updates when many files in a directory are changed within a brief period.
1877  *
1878  * If the directory updating is defered then yaffs_update_dirty_dirs must be
1879  * called periodically.
1880  */
1881
1882 static void yaffs_update_parent(struct yaffs_obj *obj)
1883 {
1884         struct yaffs_dev *dev;
1885
1886         if (!obj)
1887                 return;
1888         dev = obj->my_dev;
1889         obj->dirty = 1;
1890         yaffs_load_current_time(obj, 0, 1);
1891         if (dev->param.defered_dir_update) {
1892                 struct list_head *link = &obj->variant.dir_variant.dirty;
1893
1894                 if (list_empty(link)) {
1895                         list_add(link, &dev->dirty_dirs);
1896                         yaffs_trace(YAFFS_TRACE_BACKGROUND,
1897                           "Added object %d to dirty directories",
1898                            obj->obj_id);
1899                 }
1900
1901         } else {
1902                 yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
1903         }
1904 }
1905
1906 void yaffs_update_dirty_dirs(struct yaffs_dev *dev)
1907 {
1908         struct list_head *link;
1909         struct yaffs_obj *obj;
1910         struct yaffs_dir_var *d_s;
1911         union yaffs_obj_var *o_v;
1912
1913         yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update dirty directories");
1914
1915         while (!list_empty(&dev->dirty_dirs)) {
1916                 link = dev->dirty_dirs.next;
1917                 list_del_init(link);
1918
1919                 d_s = list_entry(link, struct yaffs_dir_var, dirty);
1920                 o_v = list_entry(d_s, union yaffs_obj_var, dir_variant);
1921                 obj = list_entry(o_v, struct yaffs_obj, variant);
1922
1923                 yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update directory %d",
1924                         obj->obj_id);
1925
1926                 if (obj->dirty)
1927                         yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
1928         }
1929 }
1930
1931 /*
1932  * Mknod (create) a new object.
1933  * equiv_obj only has meaning for a hard link;
1934  * alias_str only has meaning for a symlink.
1935  * rdev only has meaning for devices (a subset of special objects)
1936  */
1937
1938 static struct yaffs_obj *yaffs_create_obj(enum yaffs_obj_type type,
1939                                           struct yaffs_obj *parent,
1940                                           const YCHAR *name,
1941                                           u32 mode,
1942                                           u32 uid,
1943                                           u32 gid,
1944                                           struct yaffs_obj *equiv_obj,
1945                                           const YCHAR *alias_str, u32 rdev)
1946 {
1947         struct yaffs_obj *in;
1948         YCHAR *str = NULL;
1949         struct yaffs_dev *dev = parent->my_dev;
1950
1951         /* Check if the entry exists.
1952          * If it does then fail the call since we don't want a dup. */
1953         if (yaffs_find_by_name(parent, name))
1954                 return NULL;
1955
1956         if (type == YAFFS_OBJECT_TYPE_SYMLINK) {
1957                 str = yaffs_clone_str(alias_str);
1958                 if (!str)
1959                         return NULL;
1960         }
1961
1962         in = yaffs_new_obj(dev, -1, type);
1963
1964         if (!in) {
1965                 kfree(str);
1966                 return NULL;
1967         }
1968
1969         in->hdr_chunk = 0;
1970         in->valid = 1;
1971         in->variant_type = type;
1972
1973         in->yst_mode = mode;
1974
1975         yaffs_attribs_init(in, gid, uid, rdev);
1976
1977         in->n_data_chunks = 0;
1978
1979         yaffs_set_obj_name(in, name);
1980         in->dirty = 1;
1981
1982         yaffs_add_obj_to_dir(parent, in);
1983
1984         in->my_dev = parent->my_dev;
1985
1986         switch (type) {
1987         case YAFFS_OBJECT_TYPE_SYMLINK:
1988                 in->variant.symlink_variant.alias = str;
1989                 break;
1990         case YAFFS_OBJECT_TYPE_HARDLINK:
1991                 in->variant.hardlink_variant.equiv_obj = equiv_obj;
1992                 in->variant.hardlink_variant.equiv_id = equiv_obj->obj_id;
1993                 list_add(&in->hard_links, &equiv_obj->hard_links);
1994                 break;
1995         case YAFFS_OBJECT_TYPE_FILE:
1996         case YAFFS_OBJECT_TYPE_DIRECTORY:
1997         case YAFFS_OBJECT_TYPE_SPECIAL:
1998         case YAFFS_OBJECT_TYPE_UNKNOWN:
1999                 /* do nothing */
2000                 break;
2001         }
2002
2003         if (yaffs_update_oh(in, name, 0, 0, 0, NULL) < 0) {
2004                 /* Could not create the object header, fail */
2005                 yaffs_del_obj(in);
2006                 in = NULL;
2007         }
2008
2009         if (in)
2010                 yaffs_update_parent(parent);
2011
2012         return in;
2013 }
2014
2015 struct yaffs_obj *yaffs_create_file(struct yaffs_obj *parent,
2016                                     const YCHAR *name, u32 mode, u32 uid,
2017                                     u32 gid)
2018 {
2019         return yaffs_create_obj(YAFFS_OBJECT_TYPE_FILE, parent, name, mode,
2020                                 uid, gid, NULL, NULL, 0);
2021 }
2022
2023 struct yaffs_obj *yaffs_create_dir(struct yaffs_obj *parent, const YCHAR *name,
2024                                    u32 mode, u32 uid, u32 gid)
2025 {
2026         return yaffs_create_obj(YAFFS_OBJECT_TYPE_DIRECTORY, parent, name,
2027                                 mode, uid, gid, NULL, NULL, 0);
2028 }
2029
2030 struct yaffs_obj *yaffs_create_special(struct yaffs_obj *parent,
2031                                        const YCHAR *name, u32 mode, u32 uid,
2032                                        u32 gid, u32 rdev)
2033 {
2034         return yaffs_create_obj(YAFFS_OBJECT_TYPE_SPECIAL, parent, name, mode,
2035                                 uid, gid, NULL, NULL, rdev);
2036 }
2037
2038 struct yaffs_obj *yaffs_create_symlink(struct yaffs_obj *parent,
2039                                        const YCHAR *name, u32 mode, u32 uid,
2040                                        u32 gid, const YCHAR *alias)
2041 {
2042         return yaffs_create_obj(YAFFS_OBJECT_TYPE_SYMLINK, parent, name, mode,
2043                                 uid, gid, NULL, alias, 0);
2044 }
2045
2046 /* yaffs_link_obj returns the object id of the equivalent object.*/
2047 struct yaffs_obj *yaffs_link_obj(struct yaffs_obj *parent, const YCHAR * name,
2048                                  struct yaffs_obj *equiv_obj)
2049 {
2050         /* Get the real object in case we were fed a hard link obj */
2051         equiv_obj = yaffs_get_equivalent_obj(equiv_obj);
2052
2053         if (yaffs_create_obj(YAFFS_OBJECT_TYPE_HARDLINK,
2054                         parent, name, 0, 0, 0,
2055                         equiv_obj, NULL, 0))
2056                 return equiv_obj;
2057
2058         return NULL;
2059
2060 }
2061
2062
2063
2064 /*---------------------- Block Management and Page Allocation -------------*/
2065
2066 static void yaffs_deinit_blocks(struct yaffs_dev *dev)
2067 {
2068         if (dev->block_info_alt && dev->block_info)
2069                 vfree(dev->block_info);
2070         else
2071                 kfree(dev->block_info);
2072
2073         dev->block_info_alt = 0;
2074
2075         dev->block_info = NULL;
2076
2077         if (dev->chunk_bits_alt && dev->chunk_bits)
2078                 vfree(dev->chunk_bits);
2079         else
2080                 kfree(dev->chunk_bits);
2081         dev->chunk_bits_alt = 0;
2082         dev->chunk_bits = NULL;
2083 }
2084
2085 static int yaffs_init_blocks(struct yaffs_dev *dev)
2086 {
2087         int n_blocks = dev->internal_end_block - dev->internal_start_block + 1;
2088
2089         dev->block_info = NULL;
2090         dev->chunk_bits = NULL;
2091         dev->alloc_block = -1;  /* force it to get a new one */
2092
2093         /* If the first allocation strategy fails, thry the alternate one */
2094         dev->block_info =
2095                 kmalloc(n_blocks * sizeof(struct yaffs_block_info), GFP_NOFS);
2096         if (!dev->block_info) {
2097                 dev->block_info =
2098                     vmalloc(n_blocks * sizeof(struct yaffs_block_info));
2099                 dev->block_info_alt = 1;
2100         } else {
2101                 dev->block_info_alt = 0;
2102         }
2103
2104         if (!dev->block_info)
2105                 goto alloc_error;
2106
2107         /* Set up dynamic blockinfo stuff. Round up bytes. */
2108         dev->chunk_bit_stride = (dev->param.chunks_per_block + 7) / 8;
2109         dev->chunk_bits =
2110                 kmalloc(dev->chunk_bit_stride * n_blocks, GFP_NOFS);
2111         if (!dev->chunk_bits) {
2112                 dev->chunk_bits =
2113                     vmalloc(dev->chunk_bit_stride * n_blocks);
2114                 dev->chunk_bits_alt = 1;
2115         } else {
2116                 dev->chunk_bits_alt = 0;
2117         }
2118         if (!dev->chunk_bits)
2119                 goto alloc_error;
2120
2121
2122         memset(dev->block_info, 0, n_blocks * sizeof(struct yaffs_block_info));
2123         memset(dev->chunk_bits, 0, dev->chunk_bit_stride * n_blocks);
2124         return YAFFS_OK;
2125
2126 alloc_error:
2127         yaffs_deinit_blocks(dev);
2128         return YAFFS_FAIL;
2129 }
2130
2131
2132 void yaffs_block_became_dirty(struct yaffs_dev *dev, int block_no)
2133 {
2134         struct yaffs_block_info *bi = yaffs_get_block_info(dev, block_no);
2135         int erased_ok = 0;
2136         u32 i;
2137
2138         /* If the block is still healthy erase it and mark as clean.
2139          * If the block has had a data failure, then retire it.
2140          */
2141
2142         yaffs_trace(YAFFS_TRACE_GC | YAFFS_TRACE_ERASE,
2143                 "yaffs_block_became_dirty block %d state %d %s",
2144                 block_no, bi->block_state,
2145                 (bi->needs_retiring) ? "needs retiring" : "");
2146
2147         yaffs2_clear_oldest_dirty_seq(dev, bi);
2148
2149         bi->block_state = YAFFS_BLOCK_STATE_DIRTY;
2150
2151         /* If this is the block being garbage collected then stop gc'ing */
2152         if (block_no == (int)dev->gc_block)
2153                 dev->gc_block = 0;
2154
2155         /* If this block is currently the best candidate for gc
2156          * then drop as a candidate */
2157         if (block_no == (int)dev->gc_dirtiest) {
2158                 dev->gc_dirtiest = 0;
2159                 dev->gc_pages_in_use = 0;
2160         }
2161
2162         if (!bi->needs_retiring) {
2163                 yaffs2_checkpt_invalidate(dev);
2164                 erased_ok = yaffs_erase_block(dev, block_no);
2165                 if (!erased_ok) {
2166                         dev->n_erase_failures++;
2167                         yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2168                           "**>> Erasure failed %d", block_no);
2169                 }
2170         }
2171
2172         /* Verify erasure if needed */
2173         if (erased_ok &&
2174             ((yaffs_trace_mask & YAFFS_TRACE_ERASE) ||
2175              !yaffs_skip_verification(dev))) {
2176                 for (i = 0; i < dev->param.chunks_per_block; i++) {
2177                         if (!yaffs_check_chunk_erased(dev,
2178                                 block_no * dev->param.chunks_per_block + i)) {
2179                                 yaffs_trace(YAFFS_TRACE_ERROR,
2180                                         ">>Block %d erasure supposedly OK, but chunk %d not erased",
2181                                         block_no, i);
2182                         }
2183                 }
2184         }
2185
2186         if (!erased_ok) {
2187                 /* We lost a block of free space */
2188                 dev->n_free_chunks -= dev->param.chunks_per_block;
2189                 yaffs_retire_block(dev, block_no);
2190                 yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2191                         "**>> Block %d retired", block_no);
2192                 return;
2193         }
2194
2195         /* Clean it up... */
2196         bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
2197         bi->seq_number = 0;
2198         dev->n_erased_blocks++;
2199         bi->pages_in_use = 0;
2200         bi->soft_del_pages = 0;
2201         bi->has_shrink_hdr = 0;
2202         bi->skip_erased_check = 1;      /* Clean, so no need to check */
2203         bi->gc_prioritise = 0;
2204         bi->has_summary = 0;
2205
2206         yaffs_clear_chunk_bits(dev, block_no);
2207
2208         yaffs_trace(YAFFS_TRACE_ERASE, "Erased block %d", block_no);
2209 }
2210
2211 static inline int yaffs_gc_process_chunk(struct yaffs_dev *dev,
2212                                         struct yaffs_block_info *bi,
2213                                         int old_chunk, u8 *buffer)
2214 {
2215         int new_chunk;
2216         int mark_flash = 1;
2217         struct yaffs_ext_tags tags;
2218         struct yaffs_obj *object;
2219         int matching_chunk;
2220         int ret_val = YAFFS_OK;
2221
2222         memset(&tags, 0, sizeof(tags));
2223         yaffs_rd_chunk_tags_nand(dev, old_chunk,
2224                                  buffer, &tags);
2225         object = yaffs_find_by_number(dev, tags.obj_id);
2226
2227         yaffs_trace(YAFFS_TRACE_GC_DETAIL,
2228                 "Collecting chunk in block %d, %d %d %d ",
2229                 dev->gc_chunk, tags.obj_id,
2230                 tags.chunk_id, tags.n_bytes);
2231
2232         if (object && !yaffs_skip_verification(dev)) {
2233                 if (tags.chunk_id == 0)
2234                         matching_chunk =
2235                             object->hdr_chunk;
2236                 else if (object->soft_del)
2237                         /* Defeat the test */
2238                         matching_chunk = old_chunk;
2239                 else
2240                         matching_chunk =
2241                             yaffs_find_chunk_in_file
2242                             (object, tags.chunk_id,
2243                              NULL);
2244
2245                 if (old_chunk != matching_chunk)
2246                         yaffs_trace(YAFFS_TRACE_ERROR,
2247                                 "gc: page in gc mismatch: %d %d %d %d",
2248                                 old_chunk,
2249                                 matching_chunk,
2250                                 tags.obj_id,
2251                                 tags.chunk_id);
2252         }
2253
2254         if (!object) {
2255                 yaffs_trace(YAFFS_TRACE_ERROR,
2256                         "page %d in gc has no object: %d %d %d ",
2257                         old_chunk,
2258                         tags.obj_id, tags.chunk_id,
2259                         tags.n_bytes);
2260         }
2261
2262         if (object &&
2263             object->deleted &&
2264             object->soft_del && tags.chunk_id != 0) {
2265                 /* Data chunk in a soft deleted file,
2266                  * throw it away.
2267                  * It's a soft deleted data chunk,
2268                  * No need to copy this, just forget
2269                  * about it and fix up the object.
2270                  */
2271
2272                 /* Free chunks already includes
2273                  * softdeleted chunks, how ever this
2274                  * chunk is going to soon be really
2275                  * deleted which will increment free
2276                  * chunks. We have to decrement free
2277                  * chunks so this works out properly.
2278                  */
2279                 dev->n_free_chunks--;
2280                 bi->soft_del_pages--;
2281
2282                 object->n_data_chunks--;
2283                 if (object->n_data_chunks <= 0) {
2284                         /* remeber to clean up obj */
2285                         dev->gc_cleanup_list[dev->n_clean_ups] = tags.obj_id;
2286                         dev->n_clean_ups++;
2287                 }
2288                 mark_flash = 0;
2289         } else if (object) {
2290                 /* It's either a data chunk in a live
2291                  * file or an ObjectHeader, so we're
2292                  * interested in it.
2293                  * NB Need to keep the ObjectHeaders of
2294                  * deleted files until the whole file
2295                  * has been deleted off
2296                  */
2297                 tags.serial_number++;
2298                 dev->n_gc_copies++;
2299
2300                 if (tags.chunk_id == 0) {
2301                         /* It is an object Id,
2302                          * We need to nuke the shrinkheader flags since its
2303                          * work is done.
2304                          * Also need to clean up shadowing.
2305                          * NB We don't want to do all the work of translating
2306                          * object header endianism back and forth so we leave
2307                          * the oh endian in its stored order.
2308                          */
2309
2310                         struct yaffs_obj_hdr *oh;
2311                         oh = (struct yaffs_obj_hdr *) buffer;
2312
2313                         oh->is_shrink = 0;
2314                         tags.extra_is_shrink = 0;
2315                         oh->shadows_obj = 0;
2316                         oh->inband_shadowed_obj_id = 0;
2317                         tags.extra_shadows = 0;
2318
2319                         /* Update file size */
2320                         if (object->variant_type == YAFFS_OBJECT_TYPE_FILE) {
2321                                 yaffs_oh_size_load(dev, oh,
2322                                     object->variant.file_variant.stored_size, 1);
2323                                 tags.extra_file_size =
2324                                     object->variant.file_variant.stored_size;
2325                         }
2326
2327                         yaffs_verify_oh(object, oh, &tags, 1);
2328                         new_chunk =
2329                             yaffs_write_new_chunk(dev, (u8 *) oh, &tags, 1);
2330                 } else {
2331                         new_chunk =
2332                             yaffs_write_new_chunk(dev, buffer, &tags, 1);
2333                 }
2334
2335                 if (new_chunk < 0) {
2336                         ret_val = YAFFS_FAIL;
2337                 } else {
2338
2339                         /* Now fix up the Tnodes etc. */
2340
2341                         if (tags.chunk_id == 0) {
2342                                 /* It's a header */
2343                                 object->hdr_chunk = new_chunk;
2344                                 object->serial = tags.serial_number;
2345                         } else {
2346                                 /* It's a data chunk */
2347                                 yaffs_put_chunk_in_file(object, tags.chunk_id,
2348                                                         new_chunk, 0);
2349                         }
2350                 }
2351         }
2352         if (ret_val == YAFFS_OK)
2353                 yaffs_chunk_del(dev, old_chunk, mark_flash, __LINE__);
2354         return ret_val;
2355 }
2356
2357 static int yaffs_gc_block(struct yaffs_dev *dev, int block, int whole_block)
2358 {
2359         int old_chunk;
2360         int ret_val = YAFFS_OK;
2361         u32 i;
2362         int is_checkpt_block;
2363         int max_copies;
2364         int chunks_before = yaffs_get_erased_chunks(dev);
2365         int chunks_after;
2366         struct yaffs_block_info *bi = yaffs_get_block_info(dev, block);
2367
2368         is_checkpt_block = (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT);
2369
2370         yaffs_trace(YAFFS_TRACE_TRACING,
2371                 "Collecting block %d, in use %d, shrink %d, whole_block %d",
2372                 block, bi->pages_in_use, bi->has_shrink_hdr,
2373                 whole_block);
2374
2375         /*yaffs_verify_free_chunks(dev); */
2376
2377         if (bi->block_state == YAFFS_BLOCK_STATE_FULL)
2378                 bi->block_state = YAFFS_BLOCK_STATE_COLLECTING;
2379
2380         bi->has_shrink_hdr = 0; /* clear the flag so that the block can erase */
2381
2382         dev->gc_disable = 1;
2383
2384         yaffs_summary_gc(dev, block);
2385
2386         if (is_checkpt_block || !yaffs_still_some_chunks(dev, block)) {
2387                 yaffs_trace(YAFFS_TRACE_TRACING,
2388                         "Collecting block %d that has no chunks in use",
2389                         block);
2390                 yaffs_block_became_dirty(dev, block);
2391         } else {
2392
2393                 u8 *buffer = yaffs_get_temp_buffer(dev);
2394
2395                 yaffs_verify_blk(dev, bi, block);
2396
2397                 max_copies = (whole_block) ? dev->param.chunks_per_block : 5;
2398                 old_chunk = block * dev->param.chunks_per_block + dev->gc_chunk;
2399
2400                 for (/* init already done */ ;
2401                      ret_val == YAFFS_OK &&
2402                      dev->gc_chunk < dev->param.chunks_per_block &&
2403                      (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) &&
2404                      max_copies > 0;
2405                      dev->gc_chunk++, old_chunk++) {
2406                         if (yaffs_check_chunk_bit(dev, block, dev->gc_chunk)) {
2407                                 /* Page is in use and might need to be copied */
2408                                 max_copies--;
2409                                 ret_val = yaffs_gc_process_chunk(dev, bi,
2410                                                         old_chunk, buffer);
2411                         }
2412                 }
2413                 yaffs_release_temp_buffer(dev, buffer);
2414         }
2415
2416         yaffs_verify_collected_blk(dev, bi, block);
2417
2418         if (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
2419                 /*
2420                  * The gc did not complete. Set block state back to FULL
2421                  * because checkpointing does not restore gc.
2422                  */
2423                 bi->block_state = YAFFS_BLOCK_STATE_FULL;
2424         } else {
2425                 /* The gc completed. */
2426                 /* Do any required cleanups */
2427                 for (i = 0; i < dev->n_clean_ups; i++) {
2428                         /* Time to delete the file too */
2429                         struct yaffs_obj *object =
2430                             yaffs_find_by_number(dev, dev->gc_cleanup_list[i]);
2431                         if (object) {
2432                                 yaffs_free_tnode(dev,
2433                                           object->variant.file_variant.top);
2434                                 object->variant.file_variant.top = NULL;
2435                                 yaffs_trace(YAFFS_TRACE_GC,
2436                                         "yaffs: About to finally delete object %d",
2437                                         object->obj_id);
2438                                 yaffs_generic_obj_del(object);
2439                                 object->my_dev->n_deleted_files--;
2440                         }
2441
2442                 }
2443                 chunks_after = yaffs_get_erased_chunks(dev);
2444                 if (chunks_before >= chunks_after)
2445                         yaffs_trace(YAFFS_TRACE_GC,
2446                                 "gc did not increase free chunks before %d after %d",
2447                                 chunks_before, chunks_after);
2448                 dev->gc_block = 0;
2449                 dev->gc_chunk = 0;
2450                 dev->n_clean_ups = 0;
2451         }
2452
2453         dev->gc_disable = 0;
2454
2455         return ret_val;
2456 }
2457
2458 /*
2459  * find_gc_block() selects the dirtiest block (or close enough)
2460  * for garbage collection.
2461  */
2462
2463 static unsigned yaffs_find_gc_block(struct yaffs_dev *dev,
2464                                     int aggressive, int background)
2465 {
2466         u32 i;
2467         u32 iterations;
2468         u32 selected = 0;
2469         int prioritised = 0;
2470         int prioritised_exist = 0;
2471         struct yaffs_block_info *bi;
2472         u32 threshold = dev->param.chunks_per_block;
2473
2474         (void) prioritised;
2475
2476         /* First let's see if we need to grab a prioritised block */
2477         if (dev->has_pending_prioritised_gc && !aggressive) {
2478                 dev->gc_dirtiest = 0;
2479                 bi = dev->block_info;
2480                 for (i = dev->internal_start_block;
2481                      i <= dev->internal_end_block && !selected; i++) {
2482
2483                         if (bi->gc_prioritise) {
2484                                 prioritised_exist = 1;
2485                                 if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
2486                                     yaffs_block_ok_for_gc(dev, bi)) {
2487                                         selected = i;
2488                                         prioritised = 1;
2489                                 }
2490                         }
2491                         bi++;
2492                 }
2493
2494                 /*
2495                  * If there is a prioritised block and none was selected then
2496                  * this happened because there is at least one old dirty block
2497                  * gumming up the works. Let's gc the oldest dirty block.
2498                  */
2499
2500                 if (prioritised_exist &&
2501                     !selected && dev->oldest_dirty_block > 0)
2502                         selected = dev->oldest_dirty_block;
2503
2504                 if (!prioritised_exist) /* None found, so we can clear this */
2505                         dev->has_pending_prioritised_gc = 0;
2506         }
2507
2508         /* If we're doing aggressive GC then we are happy to take a less-dirty
2509          * block, and search harder.
2510          * else (leasurely gc), then we only bother to do this if the
2511          * block has only a few pages in use.
2512          */
2513
2514         if (!selected) {
2515                 u32 pages_used;
2516                 int n_blocks =
2517                     dev->internal_end_block - dev->internal_start_block + 1;
2518                 if (aggressive) {
2519                         threshold = dev->param.chunks_per_block;
2520                         iterations = n_blocks;
2521                 } else {
2522                         u32 max_threshold;
2523
2524                         if (background)
2525                                 max_threshold = dev->param.chunks_per_block / 2;
2526                         else
2527                                 max_threshold = dev->param.chunks_per_block / 8;
2528
2529                         if (max_threshold < YAFFS_GC_PASSIVE_THRESHOLD)
2530                                 max_threshold = YAFFS_GC_PASSIVE_THRESHOLD;
2531
2532                         threshold = background ? (dev->gc_not_done + 2) * 2 : 0;
2533                         if (threshold < YAFFS_GC_PASSIVE_THRESHOLD)
2534                                 threshold = YAFFS_GC_PASSIVE_THRESHOLD;
2535                         if (threshold > max_threshold)
2536                                 threshold = max_threshold;
2537
2538                         iterations = n_blocks / 16 + 1;
2539                         if (iterations > 100)
2540                                 iterations = 100;
2541                 }
2542
2543                 for (i = 0;
2544                      i < iterations &&
2545                      (dev->gc_dirtiest < 1 ||
2546                       dev->gc_pages_in_use > YAFFS_GC_GOOD_ENOUGH);
2547                      i++) {
2548                         dev->gc_block_finder++;
2549                         if (dev->gc_block_finder < dev->internal_start_block ||
2550                             dev->gc_block_finder > dev->internal_end_block)
2551                                 dev->gc_block_finder =
2552                                     dev->internal_start_block;
2553
2554                         bi = yaffs_get_block_info(dev, dev->gc_block_finder);
2555
2556                         pages_used = bi->pages_in_use - bi->soft_del_pages;
2557
2558                         if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
2559                             pages_used < dev->param.chunks_per_block &&
2560                             (dev->gc_dirtiest < 1 ||
2561                              pages_used < dev->gc_pages_in_use) &&
2562                             yaffs_block_ok_for_gc(dev, bi)) {
2563                                 dev->gc_dirtiest = dev->gc_block_finder;
2564                                 dev->gc_pages_in_use = pages_used;
2565                         }
2566                 }
2567
2568                 if (dev->gc_dirtiest > 0 && dev->gc_pages_in_use <= threshold)
2569                         selected = dev->gc_dirtiest;
2570         }
2571
2572         /*
2573          * If nothing has been selected for a while, try the oldest dirty
2574          * because that's gumming up the works.
2575          */
2576
2577         if (!selected && dev->param.is_yaffs2 &&
2578             dev->gc_not_done >= (background ? 10 : 20)) {
2579                 yaffs2_find_oldest_dirty_seq(dev);
2580                 if (dev->oldest_dirty_block > 0) {
2581                         selected = dev->oldest_dirty_block;
2582                         dev->gc_dirtiest = selected;
2583                         dev->oldest_dirty_gc_count++;
2584                         bi = yaffs_get_block_info(dev, selected);
2585                         dev->gc_pages_in_use =
2586                             bi->pages_in_use - bi->soft_del_pages;
2587                 } else {
2588                         dev->gc_not_done = 0;
2589                 }
2590         }
2591
2592         if (selected) {
2593                 yaffs_trace(YAFFS_TRACE_GC,
2594                         "GC Selected block %d with %d free, prioritised:%d",
2595                         selected,
2596                         dev->param.chunks_per_block - dev->gc_pages_in_use,
2597                         prioritised);
2598
2599                 dev->n_gc_blocks++;
2600                 if (background)
2601                         dev->bg_gcs++;
2602
2603                 dev->gc_dirtiest = 0;
2604                 dev->gc_pages_in_use = 0;
2605                 dev->gc_not_done = 0;
2606                 if (dev->refresh_skip > 0)
2607                         dev->refresh_skip--;
2608         } else {
2609                 dev->gc_not_done++;
2610                 yaffs_trace(YAFFS_TRACE_GC,
2611                         "GC none: finder %d skip %d threshold %d dirtiest %d using %d oldest %d%s",
2612                         dev->gc_block_finder, dev->gc_not_done, threshold,
2613                         dev->gc_dirtiest, dev->gc_pages_in_use,
2614                         dev->oldest_dirty_block, background ? " bg" : "");
2615         }
2616
2617         return selected;
2618 }
2619
2620 /* New garbage collector
2621  * If we're very low on erased blocks then we do aggressive garbage collection
2622  * otherwise we do "leasurely" garbage collection.
2623  * Aggressive gc looks further (whole array) and will accept less dirty blocks.
2624  * Passive gc only inspects smaller areas and only accepts more dirty blocks.
2625  *
2626  * The idea is to help clear out space in a more spread-out manner.
2627  * Dunno if it really does anything useful.
2628  */
2629 static int yaffs_check_gc(struct yaffs_dev *dev, int background)
2630 {
2631         int aggressive = 0;
2632         int gc_ok = YAFFS_OK;
2633         int max_tries = 0;
2634         int min_erased;
2635         int erased_chunks;
2636         int checkpt_block_adjust;
2637
2638         if (dev->param.gc_control_fn &&
2639                 (dev->param.gc_control_fn(dev) & 1) == 0)
2640                 return YAFFS_OK;
2641
2642         if (dev->gc_disable)
2643                 /* Bail out so we don't get recursive gc */
2644                 return YAFFS_OK;
2645
2646         /* This loop should pass the first time.
2647          * Only loops here if the collection does not increase space.
2648          */
2649
2650         do {
2651                 max_tries++;
2652
2653                 checkpt_block_adjust = yaffs_calc_checkpt_blocks_required(dev);
2654
2655                 min_erased =
2656                     dev->param.n_reserved_blocks + checkpt_block_adjust + 1;
2657                 erased_chunks =
2658                     dev->n_erased_blocks * dev->param.chunks_per_block;
2659
2660                 /* If we need a block soon then do aggressive gc. */
2661                 if (dev->n_erased_blocks < min_erased)
2662                         aggressive = 1;
2663                 else {
2664                         if (!background
2665                             && erased_chunks > (dev->n_free_chunks / 4))
2666                                 break;
2667
2668                         if (dev->gc_skip > 20)
2669                                 dev->gc_skip = 20;
2670                         if (erased_chunks < dev->n_free_chunks / 2 ||
2671                             dev->gc_skip < 1 || background)
2672                                 aggressive = 0;
2673                         else {
2674                                 dev->gc_skip--;
2675                                 break;
2676                         }
2677                 }
2678
2679                 dev->gc_skip = 5;
2680
2681                 /* If we don't already have a block being gc'd then see if we
2682                  * should start another */
2683
2684                 if (dev->gc_block < 1 && !aggressive) {
2685                         dev->gc_block = yaffs2_find_refresh_block(dev);
2686                         dev->gc_chunk = 0;
2687                         dev->n_clean_ups = 0;
2688                 }
2689                 if (dev->gc_block < 1) {
2690                         dev->gc_block =
2691                             yaffs_find_gc_block(dev, aggressive, background);
2692                         dev->gc_chunk = 0;
2693                         dev->n_clean_ups = 0;
2694                 }
2695
2696                 if (dev->gc_block > 0) {
2697                         dev->all_gcs++;
2698                         if (!aggressive)
2699                                 dev->passive_gc_count++;
2700
2701                         yaffs_trace(YAFFS_TRACE_GC,
2702                                 "yaffs: GC n_erased_blocks %d aggressive %d",
2703                                 dev->n_erased_blocks, aggressive);
2704
2705                         gc_ok = yaffs_gc_block(dev, dev->gc_block, aggressive);
2706                 }
2707
2708                 if (dev->n_erased_blocks < (int)dev->param.n_reserved_blocks &&
2709                     dev->gc_block > 0) {
2710                         yaffs_trace(YAFFS_TRACE_GC,
2711                                 "yaffs: GC !!!no reclaim!!! n_erased_blocks %d after try %d block %d",
2712                                 dev->n_erased_blocks, max_tries,
2713                                 dev->gc_block);
2714                 }
2715         } while ((dev->n_erased_blocks < (int)dev->param.n_reserved_blocks) &&
2716                  (dev->gc_block > 0) && (max_tries < 2));
2717
2718         return aggressive ? gc_ok : YAFFS_OK;
2719 }
2720
2721 /*
2722  * yaffs_bg_gc()
2723  * Garbage collects. Intended to be called from a background thread.
2724  * Returns non-zero if at least half the free chunks are erased.
2725  */
2726 int yaffs_bg_gc(struct yaffs_dev *dev, unsigned urgency)
2727 {
2728         int erased_chunks = dev->n_erased_blocks * dev->param.chunks_per_block;
2729
2730         (void) urgency;
2731         yaffs_trace(YAFFS_TRACE_BACKGROUND, "Background gc %u", urgency);
2732
2733         yaffs_check_gc(dev, 1);
2734         return erased_chunks > dev->n_free_chunks / 2;
2735 }
2736
2737 /*-------------------- Data file manipulation -----------------*/
2738
2739 static int yaffs_rd_data_obj(struct yaffs_obj *in, int inode_chunk, u8 * buffer)
2740 {
2741         int nand_chunk = yaffs_find_chunk_in_file(in, inode_chunk, NULL);
2742
2743         if (nand_chunk >= 0)
2744                 return yaffs_rd_chunk_tags_nand(in->my_dev, nand_chunk,
2745                                                 buffer, NULL);
2746         else {
2747                 yaffs_trace(YAFFS_TRACE_NANDACCESS,
2748                         "Chunk %d not found zero instead",
2749                         nand_chunk);
2750                 /* get sane (zero) data if you read a hole */
2751                 memset(buffer, 0, in->my_dev->data_bytes_per_chunk);
2752                 return 0;
2753         }
2754
2755 }
2756
2757 void yaffs_chunk_del(struct yaffs_dev *dev, int chunk_id, int mark_flash,
2758                      int lyn)
2759 {
2760         int block;
2761         int page;
2762         struct yaffs_ext_tags tags;
2763         struct yaffs_block_info *bi;
2764
2765         (void) lyn;
2766         if (chunk_id <= 0)
2767                 return;
2768
2769         dev->n_deletions++;
2770         block = chunk_id / dev->param.chunks_per_block;
2771         page = chunk_id % dev->param.chunks_per_block;
2772
2773         if (!yaffs_check_chunk_bit(dev, block, page))
2774                 yaffs_trace(YAFFS_TRACE_VERIFY,
2775                         "Deleting invalid chunk %d", chunk_id);
2776
2777         bi = yaffs_get_block_info(dev, block);
2778
2779         yaffs2_update_oldest_dirty_seq(dev, block, bi);
2780
2781         yaffs_trace(YAFFS_TRACE_DELETION,
2782                 "line %d delete of chunk %d",
2783                 lyn, chunk_id);
2784
2785         if (!dev->param.is_yaffs2 && mark_flash &&
2786             bi->block_state != YAFFS_BLOCK_STATE_COLLECTING) {
2787
2788                 memset(&tags, 0, sizeof(tags));
2789                 tags.is_deleted = 1;
2790                 yaffs_wr_chunk_tags_nand(dev, chunk_id, NULL, &tags);
2791                 yaffs_handle_chunk_update(dev, chunk_id, &tags);
2792         } else {
2793                 dev->n_unmarked_deletions++;
2794         }
2795
2796         /* Pull out of the management area.
2797          * If the whole block became dirty, this will kick off an erasure.
2798          */
2799         if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING ||
2800             bi->block_state == YAFFS_BLOCK_STATE_FULL ||
2801             bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCAN ||
2802             bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
2803                 dev->n_free_chunks++;
2804                 yaffs_clear_chunk_bit(dev, block, page);
2805                 bi->pages_in_use--;
2806
2807                 if (bi->pages_in_use == 0 &&
2808                     !bi->has_shrink_hdr &&
2809                     bi->block_state != YAFFS_BLOCK_STATE_ALLOCATING &&
2810                     bi->block_state != YAFFS_BLOCK_STATE_NEEDS_SCAN) {
2811                         yaffs_block_became_dirty(dev, block);
2812                 }
2813         }
2814 }
2815
2816 int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
2817                         const u8 *buffer, int n_bytes, int use_reserve)
2818 {
2819         /* Find old chunk Need to do this to get serial number
2820          * Write new one and patch into tree.
2821          * Invalidate old tags.
2822          */
2823
2824         int prev_chunk_id;
2825         struct yaffs_ext_tags prev_tags;
2826         int new_chunk_id;
2827         struct yaffs_ext_tags new_tags;
2828         struct yaffs_dev *dev = in->my_dev;
2829         loff_t endpos;
2830
2831         yaffs_check_gc(dev, 0);
2832
2833         /* Get the previous chunk at this location in the file if it exists.
2834          * If it does not exist then put a zero into the tree. This creates
2835          * the tnode now, rather than later when it is harder to clean up.
2836          */
2837         prev_chunk_id = yaffs_find_chunk_in_file(in, inode_chunk, &prev_tags);
2838         if (prev_chunk_id < 1 &&
2839             !yaffs_put_chunk_in_file(in, inode_chunk, 0, 0))
2840                 return 0;
2841
2842         /* Set up new tags */
2843         memset(&new_tags, 0, sizeof(new_tags));
2844
2845         new_tags.chunk_id = inode_chunk;
2846         new_tags.obj_id = in->obj_id;
2847         new_tags.serial_number =
2848             (prev_chunk_id > 0) ? prev_tags.serial_number + 1 : 1;
2849         new_tags.n_bytes = n_bytes;
2850
2851         if (n_bytes < 1 || n_bytes > (int)dev->data_bytes_per_chunk) {
2852                 yaffs_trace(YAFFS_TRACE_ERROR,
2853                   "Writing %d bytes to chunk!!!!!!!!!",
2854                    n_bytes);
2855                 BUG();
2856         }
2857
2858         /*
2859          * If this is a data chunk and the write goes past the end of the stored
2860          * size then update the stored_size.
2861          */
2862         if (inode_chunk > 0) {
2863                 endpos =  (inode_chunk - 1) * dev->data_bytes_per_chunk +
2864                                 n_bytes;
2865                 if (in->variant.file_variant.stored_size < endpos)
2866                         in->variant.file_variant.stored_size = endpos;
2867         }
2868
2869         new_chunk_id =
2870             yaffs_write_new_chunk(dev, buffer, &new_tags, use_reserve);
2871
2872         if (new_chunk_id > 0) {
2873                 yaffs_put_chunk_in_file(in, inode_chunk, new_chunk_id, 0);
2874
2875                 if (prev_chunk_id > 0)
2876                         yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
2877
2878                 yaffs_verify_file_sane(in);
2879         }
2880         return new_chunk_id;
2881 }
2882
2883
2884
2885 static int yaffs_do_xattrib_mod(struct yaffs_obj *obj, int set,
2886                                 const YCHAR *name, const void *value, int size,
2887                                 int flags)
2888 {
2889         struct yaffs_xattr_mod xmod;
2890         int result;
2891
2892         xmod.set = set;
2893         xmod.name = name;
2894         xmod.data = value;
2895         xmod.size = size;
2896         xmod.flags = flags;
2897         xmod.result = -ENOSPC;
2898
2899         result = yaffs_update_oh(obj, NULL, 0, 0, 0, &xmod);
2900
2901         if (result > 0)
2902                 return xmod.result;
2903         else
2904                 return -ENOSPC;
2905 }
2906
2907 static int yaffs_apply_xattrib_mod(struct yaffs_obj *obj, char *buffer,
2908                                    struct yaffs_xattr_mod *xmod)
2909 {
2910         int retval = 0;
2911         int x_offs = sizeof(struct yaffs_obj_hdr);
2912         struct yaffs_dev *dev = obj->my_dev;
2913         int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
2914         char *x_buffer = buffer + x_offs;
2915
2916         if (xmod->set)
2917                 retval =
2918                     nval_set(dev, x_buffer, x_size, xmod->name, xmod->data,
2919                              xmod->size, xmod->flags);
2920         else
2921                 retval = nval_del(dev, x_buffer, x_size, xmod->name);
2922
2923         obj->has_xattr = nval_hasvalues(dev, x_buffer, x_size);
2924         obj->xattr_known = 1;
2925         xmod->result = retval;
2926
2927         return retval;
2928 }
2929
2930 static int yaffs_do_xattrib_fetch(struct yaffs_obj *obj, const YCHAR *name,
2931                                   void *value, int size)
2932 {
2933         char *buffer = NULL;
2934         int result;
2935         struct yaffs_ext_tags tags;
2936         struct yaffs_dev *dev = obj->my_dev;
2937         int x_offs = sizeof(struct yaffs_obj_hdr);
2938         int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
2939         char *x_buffer;
2940         int retval = 0;
2941
2942         if (obj->hdr_chunk < 1)
2943                 return -ENODATA;
2944
2945         /* If we know that the object has no xattribs then don't do all the
2946          * reading and parsing.
2947          */
2948         if (obj->xattr_known && !obj->has_xattr) {
2949                 if (name)
2950                         return -ENODATA;
2951                 else
2952                         return 0;
2953         }
2954
2955         buffer = (char *)yaffs_get_temp_buffer(dev);
2956         if (!buffer)
2957                 return -ENOMEM;
2958
2959         result =
2960             yaffs_rd_chunk_tags_nand(dev, obj->hdr_chunk, (u8 *) buffer, &tags);
2961
2962         if (result != YAFFS_OK)
2963                 retval = -ENOENT;
2964         else {
2965                 x_buffer = buffer + x_offs;
2966
2967                 if (!obj->xattr_known) {
2968                         obj->has_xattr = nval_hasvalues(dev, x_buffer, x_size);
2969                         obj->xattr_known = 1;
2970                 }
2971
2972                 if (name)
2973                         retval = nval_get(dev, x_buffer, x_size,
2974                                                 name, value, size);
2975                 else
2976                         retval = nval_list(dev, x_buffer, x_size, value, size);
2977         }
2978         yaffs_release_temp_buffer(dev, (u8 *) buffer);
2979         return retval;
2980 }
2981
2982 int yaffs_set_xattrib(struct yaffs_obj *obj, const YCHAR * name,
2983                       const void *value, int size, int flags)
2984 {
2985         return yaffs_do_xattrib_mod(obj, 1, name, value, size, flags);
2986 }
2987
2988 int yaffs_remove_xattrib(struct yaffs_obj *obj, const YCHAR * name)
2989 {
2990         return yaffs_do_xattrib_mod(obj, 0, name, NULL, 0, 0);
2991 }
2992
2993 int yaffs_get_xattrib(struct yaffs_obj *obj, const YCHAR * name, void *value,
2994                       int size)
2995 {
2996         return yaffs_do_xattrib_fetch(obj, name, value, size);
2997 }
2998
2999 int yaffs_list_xattrib(struct yaffs_obj *obj, char *buffer, int size)
3000 {
3001         return yaffs_do_xattrib_fetch(obj, NULL, buffer, size);
3002 }
3003
3004 static void yaffs_check_obj_details_loaded(struct yaffs_obj *in)
3005 {
3006         u8 *buf;
3007         struct yaffs_obj_hdr *oh;
3008         struct yaffs_dev *dev;
3009         struct yaffs_ext_tags tags;
3010         int result;
3011
3012         if (!in || !in->lazy_loaded || in->hdr_chunk < 1)
3013                 return;
3014
3015         dev = in->my_dev;
3016         buf = yaffs_get_temp_buffer(dev);
3017
3018         result = yaffs_rd_chunk_tags_nand(dev, in->hdr_chunk, buf, &tags);
3019
3020         if (result == YAFFS_FAIL) {
3021                 yaffs_release_temp_buffer(dev, buf);
3022                 return;
3023         }
3024
3025         oh = (struct yaffs_obj_hdr *)buf;
3026
3027         yaffs_do_endian_oh(dev, oh);
3028
3029         in->lazy_loaded = 0;
3030         in->yst_mode = oh->yst_mode;
3031         yaffs_load_attribs(in, oh);
3032         yaffs_set_obj_name_from_oh(in, oh);
3033
3034         if (in->variant_type == YAFFS_OBJECT_TYPE_SYMLINK)
3035                 in->variant.symlink_variant.alias =
3036                     yaffs_clone_str(oh->alias);
3037         yaffs_release_temp_buffer(dev, buf);
3038 }
3039
3040 /* UpdateObjectHeader updates the header on NAND for an object.
3041  * If name is not NULL, then that new name is used.
3042  *
3043  * We're always creating the obj header from scratch (except reading
3044  * the old name) so first set up in cpu endianness then run it through
3045  * endian fixing at the end.
3046  *
3047  * However, a twist: If there are xattribs we leave them as they were.
3048  *
3049  * Careful! The buffer holds the whole chunk. Part of the chunk holds the
3050  * object header and the rest holds the xattribs, therefore we use a buffer
3051  * pointer and an oh pointer to point to the same memory.
3052  */
3053
3054 int yaffs_update_oh(struct yaffs_obj *in, const YCHAR *name, int force,
3055                     int is_shrink, int shadows, struct yaffs_xattr_mod *xmod)
3056 {
3057
3058         struct yaffs_block_info *bi;
3059         struct yaffs_dev *dev = in->my_dev;
3060         int prev_chunk_id;
3061         int ret_val = 0;
3062         int result = 0;
3063         int new_chunk_id;
3064         struct yaffs_ext_tags new_tags;
3065         struct yaffs_ext_tags old_tags;
3066         const YCHAR *alias = NULL;
3067         u8 *buffer = NULL;
3068         YCHAR old_name[YAFFS_MAX_NAME_LENGTH + 1];
3069         struct yaffs_obj_hdr *oh = NULL;
3070         loff_t file_size = 0;
3071
3072         strcpy(old_name, _Y("silly old name"));
3073
3074         if (in->fake && in != dev->root_dir && !force && !xmod)
3075                 return ret_val;
3076
3077         yaffs_check_gc(dev, 0);
3078         yaffs_check_obj_details_loaded(in);
3079
3080         buffer = yaffs_get_temp_buffer(in->my_dev);
3081         oh = (struct yaffs_obj_hdr *)buffer;
3082
3083         prev_chunk_id = in->hdr_chunk;
3084
3085         if (prev_chunk_id > 0) {
3086                 /* Access the old obj header just to read the name. */
3087                 result = yaffs_rd_chunk_tags_nand(dev, prev_chunk_id,
3088                                                   buffer, &old_tags);
3089                 if (result == YAFFS_OK) {
3090                         yaffs_verify_oh(in, oh, &old_tags, 0);
3091                         memcpy(old_name, oh->name, sizeof(oh->name));
3092
3093                         /*
3094                         * NB We only wipe the object header area because the rest of
3095                         * the buffer might contain xattribs.
3096                         */
3097                         memset(oh, 0xff, sizeof(*oh));
3098                 }
3099         } else {
3100                 memset(buffer, 0xff, dev->data_bytes_per_chunk);
3101         }
3102
3103         oh->type = in->variant_type;
3104         oh->yst_mode = in->yst_mode;
3105         oh->shadows_obj = oh->inband_shadowed_obj_id = shadows;
3106
3107         yaffs_load_attribs_oh(oh, in);
3108
3109         if (in->parent)
3110                 oh->parent_obj_id = in->parent->obj_id;
3111         else
3112                 oh->parent_obj_id = 0;
3113
3114         if (name && *name) {
3115                 memset(oh->name, 0, sizeof(oh->name));
3116                 yaffs_load_oh_from_name(dev, oh->name, name);
3117         } else if (prev_chunk_id > 0) {
3118                 memcpy(oh->name, old_name, sizeof(oh->name));
3119         } else {
3120                 memset(oh->name, 0, sizeof(oh->name));
3121         }
3122
3123         oh->is_shrink = is_shrink;
3124
3125         switch (in->variant_type) {
3126         case YAFFS_OBJECT_TYPE_UNKNOWN:
3127                 /* Should not happen */
3128                 break;
3129         case YAFFS_OBJECT_TYPE_FILE:
3130                 if (oh->parent_obj_id != YAFFS_OBJECTID_DELETED &&
3131                     oh->parent_obj_id != YAFFS_OBJECTID_UNLINKED)
3132                         file_size = in->variant.file_variant.stored_size;
3133                 yaffs_oh_size_load(dev, oh, file_size, 0);
3134                 break;
3135         case YAFFS_OBJECT_TYPE_HARDLINK:
3136                 oh->equiv_id = in->variant.hardlink_variant.equiv_id;
3137                 break;
3138         case YAFFS_OBJECT_TYPE_SPECIAL:
3139                 /* Do nothing */
3140                 break;
3141         case YAFFS_OBJECT_TYPE_DIRECTORY:
3142                 /* Do nothing */
3143                 break;
3144         case YAFFS_OBJECT_TYPE_SYMLINK:
3145                 alias = in->variant.symlink_variant.alias;
3146                 if (!alias)
3147                         alias = _Y("no alias");
3148                 strncpy(oh->alias, alias, YAFFS_MAX_ALIAS_LENGTH);
3149                 oh->alias[YAFFS_MAX_ALIAS_LENGTH] = 0;
3150                 break;
3151         }
3152
3153         /* process any xattrib modifications */
3154         if (xmod)
3155                 yaffs_apply_xattrib_mod(in, (char *)buffer, xmod);
3156
3157         /* Tags */
3158         memset(&new_tags, 0, sizeof(new_tags));
3159         in->serial++;
3160         new_tags.chunk_id = 0;
3161         new_tags.obj_id = in->obj_id;
3162         new_tags.serial_number = in->serial;
3163
3164         /* Add extra info for file header */
3165         new_tags.extra_available = 1;
3166         new_tags.extra_parent_id = oh->parent_obj_id;
3167         new_tags.extra_file_size = file_size;
3168         new_tags.extra_is_shrink = oh->is_shrink;
3169         new_tags.extra_equiv_id = oh->equiv_id;
3170         new_tags.extra_shadows = (oh->shadows_obj > 0) ? 1 : 0;
3171         new_tags.extra_obj_type = in->variant_type;
3172
3173         /* Now endian swizzle the oh if needed. */
3174         yaffs_do_endian_oh(dev, oh);
3175
3176         yaffs_verify_oh(in, oh, &new_tags, 1);
3177
3178         /* Create new chunk in NAND */
3179         new_chunk_id =
3180             yaffs_write_new_chunk(dev, buffer, &new_tags,
3181                                   (prev_chunk_id > 0) ? 1 : 0);
3182
3183         if (buffer)
3184                 yaffs_release_temp_buffer(dev, buffer);
3185
3186         if (new_chunk_id < 0)
3187                 return new_chunk_id;
3188
3189         in->hdr_chunk = new_chunk_id;
3190
3191         if (prev_chunk_id > 0)
3192                 yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
3193
3194         if (!yaffs_obj_cache_dirty(in))
3195                 in->dirty = 0;
3196
3197         /* If this was a shrink, then mark the block
3198          * that the chunk lives on */
3199         if (is_shrink) {
3200                 bi = yaffs_get_block_info(in->my_dev,
3201                                           new_chunk_id /
3202                                           in->my_dev->param.chunks_per_block);
3203                 bi->has_shrink_hdr = 1;
3204         }
3205
3206         return new_chunk_id;
3207 }
3208
3209 /*--------------------- File read/write ------------------------
3210  * Read and write have very similar structures.
3211  * In general the read/write has three parts to it
3212  * An incomplete chunk to start with (if the read/write is not chunk-aligned)
3213  * Some complete chunks
3214  * An incomplete chunk to end off with
3215  *
3216  * Curve-balls: the first chunk might also be the last chunk.
3217  */
3218
3219 int yaffs_file_rd(struct yaffs_obj *in, u8 * buffer, loff_t offset, int n_bytes)
3220 {
3221         int chunk;
3222         u32 start;
3223         int n_copy;
3224         int n = n_bytes;
3225         int n_done = 0;
3226         struct yaffs_cache *cache;
3227         struct yaffs_dev *dev;
3228
3229         dev = in->my_dev;
3230
3231         while (n > 0) {
3232                 yaffs_addr_to_chunk(dev, offset, &chunk, &start);
3233                 chunk++;
3234
3235                 /* OK now check for the curveball where the start and end are in
3236                  * the same chunk.
3237                  */
3238                 if ((start + n) < dev->data_bytes_per_chunk)
3239                         n_copy = n;
3240                 else
3241                         n_copy = dev->data_bytes_per_chunk - start;
3242
3243                 cache = yaffs_find_chunk_cache(in, chunk);
3244
3245                 /* If the chunk is already in the cache or it is less than
3246                  * a whole chunk or we're using inband tags then use the cache
3247                  * (if there is caching) else bypass the cache.
3248                  */
3249                 if (cache || n_copy != (int)dev->data_bytes_per_chunk ||
3250                     dev->param.inband_tags) {
3251                         if (dev->param.n_caches > 0) {
3252
3253                                 /* If we can't find the data in the cache,
3254                                  * then load it up. */
3255
3256                                 if (!cache) {
3257                                         cache =
3258                                             yaffs_grab_chunk_cache(in->my_dev);
3259                                         cache->object = in;
3260                                         cache->chunk_id = chunk;
3261                                         cache->dirty = 0;
3262                                         cache->locked = 0;
3263                                         yaffs_rd_data_obj(in, chunk,
3264                                                           cache->data);
3265                                         cache->n_bytes = 0;
3266                                 }
3267
3268                                 yaffs_use_cache(dev, cache, 0);
3269
3270                                 cache->locked = 1;
3271
3272                                 memcpy(buffer, &cache->data[start], n_copy);
3273
3274                                 cache->locked = 0;
3275                         } else {
3276                                 /* Read into the local buffer then copy.. */
3277
3278                                 u8 *local_buffer =
3279                                     yaffs_get_temp_buffer(dev);
3280                                 yaffs_rd_data_obj(in, chunk, local_buffer);
3281
3282                                 memcpy(buffer, &local_buffer[start], n_copy);
3283
3284                                 yaffs_release_temp_buffer(dev, local_buffer);
3285                         }
3286                 } else {
3287                         /* A full chunk. Read directly into the buffer. */
3288                         yaffs_rd_data_obj(in, chunk, buffer);
3289                 }
3290                 n -= n_copy;
3291                 offset += n_copy;
3292                 buffer += n_copy;
3293                 n_done += n_copy;
3294         }
3295         return n_done;
3296 }
3297
3298 int yaffs_do_file_wr(struct yaffs_obj *in, const u8 *buffer, loff_t offset,
3299                      int n_bytes, int write_through)
3300 {
3301
3302         int chunk;
3303         u32 start;
3304         int n_copy;
3305         int n = n_bytes;
3306         int n_done = 0;
3307         int n_writeback;
3308         loff_t start_write = offset;
3309         int chunk_written = 0;
3310         u32 n_bytes_read;
3311         loff_t chunk_start;
3312         struct yaffs_dev *dev;
3313
3314         dev = in->my_dev;
3315
3316         while (n > 0 && chunk_written >= 0) {
3317                 yaffs_addr_to_chunk(dev, offset, &chunk, &start);
3318
3319                 if (((loff_t)chunk) *
3320                     dev->data_bytes_per_chunk + start != offset ||
3321                     start >= dev->data_bytes_per_chunk) {
3322                         yaffs_trace(YAFFS_TRACE_ERROR,
3323                                 "AddrToChunk of offset %lld gives chunk %d start %d",
3324                                 (long  long)offset, chunk, start);
3325                 }
3326                 chunk++;        /* File pos to chunk in file offset */
3327
3328                 /* OK now check for the curveball where the start and end are in
3329                  * the same chunk.
3330                  */
3331
3332                 if ((start + n) < dev->data_bytes_per_chunk) {
3333                         n_copy = n;
3334
3335                         /* Now calculate how many bytes to write back....
3336                          * If we're overwriting and not writing to then end of
3337                          * file then we need to write back as much as was there
3338                          * before.
3339                          */
3340
3341                         chunk_start = (((loff_t)(chunk - 1)) *
3342                                         dev->data_bytes_per_chunk);
3343
3344                         if (chunk_start > in->variant.file_variant.file_size)
3345                                 n_bytes_read = 0;       /* Past end of file */
3346                         else
3347                                 n_bytes_read =
3348                                     in->variant.file_variant.file_size -
3349                                     chunk_start;
3350
3351                         if (n_bytes_read > dev->data_bytes_per_chunk)
3352                                 n_bytes_read = dev->data_bytes_per_chunk;
3353
3354                         n_writeback =
3355                             (n_bytes_read >
3356                              (start + n)) ? n_bytes_read : (start + n);
3357
3358                         if (n_writeback < 0 ||
3359                             n_writeback > (int)dev->data_bytes_per_chunk)
3360                                 BUG();
3361
3362                 } else {
3363                         n_copy = dev->data_bytes_per_chunk - start;
3364                         n_writeback = dev->data_bytes_per_chunk;
3365                 }
3366
3367                 if (n_copy != (int)dev->data_bytes_per_chunk ||
3368                     !dev->param.cache_bypass_aligned ||
3369                     dev->param.inband_tags) {
3370                         /* An incomplete start or end chunk (or maybe both
3371                          * start and end chunk), or we're using inband tags,
3372                          * or we're forcing writes through the cache,
3373                          * so we want to use the cache buffers.
3374                          */
3375                         if (dev->param.n_caches > 0) {
3376                                 struct yaffs_cache *cache;
3377
3378                                 /* If we can't find the data in the cache, then
3379                                  * load the cache */
3380                                 cache = yaffs_find_chunk_cache(in, chunk);
3381
3382                                 if (!cache &&
3383                                     yaffs_check_alloc_available(dev, 1)) {
3384                                         cache = yaffs_grab_chunk_cache(dev);
3385                                         cache->object = in;
3386                                         cache->chunk_id = chunk;
3387                                         cache->dirty = 0;
3388                                         cache->locked = 0;
3389                                         yaffs_rd_data_obj(in, chunk,
3390                                                           cache->data);
3391                                 } else if (cache &&
3392                                            !cache->dirty &&
3393                                            !yaffs_check_alloc_available(dev,
3394                                                                         1)) {
3395                                         /* Drop the cache if it was a read cache
3396                                          * item and no space check has been made
3397                                          * for it.
3398                                          */
3399                                         cache = NULL;
3400                                 }
3401
3402                                 if (cache) {
3403                                         yaffs_use_cache(dev, cache, 1);
3404                                         cache->locked = 1;
3405
3406                                         memcpy(&cache->data[start], buffer,
3407                                                n_copy);
3408
3409                                         cache->locked = 0;
3410                                         cache->n_bytes = n_writeback;
3411
3412                                         if (write_through) {
3413                                                 chunk_written =
3414                                                     yaffs_wr_data_obj
3415                                                     (cache->object,
3416                                                      cache->chunk_id,
3417                                                      cache->data,
3418                                                      cache->n_bytes, 1);
3419                                                 cache->dirty = 0;
3420                                         }
3421                                 } else {
3422                                         chunk_written = -1;     /* fail write */
3423                                 }
3424                         } else {
3425                                 /* An incomplete start or end chunk (or maybe
3426                                  * both start and end chunk). Read into the
3427                                  * local buffer then copy over and write back.
3428                                  */
3429
3430                                 u8 *local_buffer = yaffs_get_temp_buffer(dev);
3431
3432                                 yaffs_rd_data_obj(in, chunk, local_buffer);
3433                                 memcpy(&local_buffer[start], buffer, n_copy);
3434
3435                                 chunk_written =
3436                                     yaffs_wr_data_obj(in, chunk,
3437                                                       local_buffer,
3438                                                       n_writeback, 0);
3439
3440                                 yaffs_release_temp_buffer(dev, local_buffer);
3441                         }
3442                 } else {
3443                         /* A full chunk. Write directly from the buffer. */
3444
3445                         chunk_written =
3446                             yaffs_wr_data_obj(in, chunk, buffer,
3447                                               dev->data_bytes_per_chunk, 0);
3448
3449                         /* Since we've overwritten the cached data,
3450                          * we better invalidate it. */
3451                         yaffs_invalidate_chunk_cache(in, chunk);
3452                 }
3453
3454                 if (chunk_written >= 0) {
3455                         n -= n_copy;
3456                         offset += n_copy;
3457                         buffer += n_copy;
3458                         n_done += n_copy;
3459                 }
3460         }
3461
3462         /* Update file object */
3463
3464         if ((start_write + n_done) > in->variant.file_variant.file_size)
3465                 in->variant.file_variant.file_size = (start_write + n_done);
3466
3467         in->dirty = 1;
3468         return n_done;
3469 }
3470
3471 int yaffs_wr_file(struct yaffs_obj *in, const u8 *buffer, loff_t offset,
3472                   int n_bytes, int write_through)
3473 {
3474         yaffs2_handle_hole(in, offset);
3475         return yaffs_do_file_wr(in, buffer, offset, n_bytes, write_through);
3476 }
3477
3478 /* ---------------------- File resizing stuff ------------------ */
3479
3480 static void yaffs_prune_chunks(struct yaffs_obj *in, loff_t new_size)
3481 {
3482
3483         struct yaffs_dev *dev = in->my_dev;
3484         loff_t old_size = in->variant.file_variant.file_size;
3485         int i;
3486         int chunk_id;
3487         u32 dummy;
3488         int last_del;
3489         int start_del;
3490
3491         if (old_size > 0)
3492                 yaffs_addr_to_chunk(dev, old_size - 1, &last_del, &dummy);
3493         else
3494                 last_del = 0;
3495
3496         yaffs_addr_to_chunk(dev, new_size + dev->data_bytes_per_chunk - 1,
3497                                 &start_del, &dummy);
3498         last_del++;
3499         start_del++;
3500
3501         /* Delete backwards so that we don't end up with holes if
3502          * power is lost part-way through the operation.
3503          */
3504         for (i = last_del; i >= start_del; i--) {
3505                 /* NB this could be optimised somewhat,
3506                  * eg. could retrieve the tags and write them without
3507                  * using yaffs_chunk_del
3508                  */
3509
3510                 chunk_id = yaffs_find_del_file_chunk(in, i, NULL);
3511
3512                 if (chunk_id < 1)
3513                         continue;
3514
3515                 if ((u32)chunk_id <
3516                     (dev->internal_start_block * dev->param.chunks_per_block) ||
3517                     (u32)chunk_id >=
3518                     ((dev->internal_end_block + 1) *
3519                       dev->param.chunks_per_block)) {
3520                         yaffs_trace(YAFFS_TRACE_ALWAYS,
3521                                 "Found daft chunk_id %d for %d",
3522                                 chunk_id, i);
3523                 } else {
3524                         in->n_data_chunks--;
3525                         yaffs_chunk_del(dev, chunk_id, 1, __LINE__);
3526                 }
3527         }
3528 }
3529
3530 void yaffs_resize_file_down(struct yaffs_obj *obj, loff_t new_size)
3531 {
3532         int new_full;
3533         u32 new_partial;
3534         struct yaffs_dev *dev = obj->my_dev;
3535
3536         yaffs_addr_to_chunk(dev, new_size, &new_full, &new_partial);
3537
3538         yaffs_prune_chunks(obj, new_size);
3539
3540         if (new_partial != 0) {
3541                 int last_chunk = 1 + new_full;
3542                 u8 *local_buffer = yaffs_get_temp_buffer(dev);
3543
3544                 /* Rewrite the last chunk with its new size and zero pad */
3545                 yaffs_rd_data_obj(obj, last_chunk, local_buffer);
3546                 memset(local_buffer + new_partial, 0,
3547                        dev->data_bytes_per_chunk - new_partial);
3548
3549                 yaffs_wr_data_obj(obj, last_chunk, local_buffer,
3550                                   new_partial, 1);
3551
3552                 yaffs_release_temp_buffer(dev, local_buffer);
3553         }
3554
3555         obj->variant.file_variant.file_size = new_size;
3556         obj->variant.file_variant.stored_size = new_size;
3557
3558         yaffs_prune_tree(dev, &obj->variant.file_variant);
3559 }
3560
3561 int yaffs_resize_file(struct yaffs_obj *in, loff_t new_size)
3562 {
3563         struct yaffs_dev *dev = in->my_dev;
3564         loff_t old_size = in->variant.file_variant.file_size;
3565
3566         yaffs_flush_file_cache(in, 1);
3567         yaffs_invalidate_file_cache(in);
3568
3569         yaffs_check_gc(dev, 0);
3570
3571         if (in->variant_type != YAFFS_OBJECT_TYPE_FILE)
3572                 return YAFFS_FAIL;
3573
3574         if (new_size == old_size)
3575                 return YAFFS_OK;
3576
3577         if (new_size > old_size) {
3578                 yaffs2_handle_hole(in, new_size);
3579                 in->variant.file_variant.file_size = new_size;
3580         } else {
3581                 /* new_size < old_size */
3582                 yaffs_resize_file_down(in, new_size);
3583         }
3584
3585         /* Write a new object header to reflect the resize.
3586          * show we've shrunk the file, if need be
3587          * Do this only if the file is not in the deleted directories
3588          * and is not shadowed.
3589          */
3590         if (in->parent &&
3591             !in->is_shadowed &&
3592             in->parent->obj_id != YAFFS_OBJECTID_UNLINKED &&
3593             in->parent->obj_id != YAFFS_OBJECTID_DELETED)
3594                 yaffs_update_oh(in, NULL, 0, 0, 0, NULL);
3595
3596         return YAFFS_OK;
3597 }
3598
3599 int yaffs_flush_file(struct yaffs_obj *in,
3600                      int update_time,
3601                      int data_sync,
3602                      int discard_cache)
3603 {
3604         if (!in->dirty)
3605                 return YAFFS_OK;
3606
3607         yaffs_flush_file_cache(in, discard_cache);
3608
3609         if (data_sync)
3610                 return YAFFS_OK;
3611
3612         if (update_time)
3613                 yaffs_load_current_time(in, 0, 0);
3614
3615         return (yaffs_update_oh(in, NULL, 0, 0, 0, NULL) >= 0) ?
3616                                 YAFFS_OK : YAFFS_FAIL;
3617 }
3618
3619
3620 /* yaffs_del_file deletes the whole file data
3621  * and the inode associated with the file.
3622  * It does not delete the links associated with the file.
3623  */
3624 static int yaffs_unlink_file_if_needed(struct yaffs_obj *in)
3625 {
3626         int ret_val;
3627         int del_now = 0;
3628         struct yaffs_dev *dev = in->my_dev;
3629
3630         if (!in->my_inode)
3631                 del_now = 1;
3632
3633         if (del_now) {
3634                 ret_val =
3635                     yaffs_change_obj_name(in, in->my_dev->del_dir,
3636                                           _Y("deleted"), 0, 0);
3637                 yaffs_trace(YAFFS_TRACE_TRACING,
3638                         "yaffs: immediate deletion of file %d",
3639                         in->obj_id);
3640                 in->deleted = 1;
3641                 in->my_dev->n_deleted_files++;
3642                 if (dev->param.disable_soft_del || dev->param.is_yaffs2)
3643                         yaffs_resize_file(in, 0);
3644                 yaffs_soft_del_file(in);
3645         } else {
3646                 ret_val =
3647                     yaffs_change_obj_name(in, in->my_dev->unlinked_dir,
3648                                           _Y("unlinked"), 0, 0);
3649         }
3650         return ret_val;
3651 }
3652
3653 static int yaffs_del_file(struct yaffs_obj *in)
3654 {
3655         int ret_val = YAFFS_OK;
3656         int deleted;    /* Need to cache value on stack if in is freed */
3657         struct yaffs_dev *dev = in->my_dev;
3658
3659         if (dev->param.disable_soft_del || dev->param.is_yaffs2)
3660                 yaffs_resize_file(in, 0);
3661
3662         if (in->n_data_chunks > 0) {
3663                 /* Use soft deletion if there is data in the file.
3664                  * That won't be the case if it has been resized to zero.
3665                  */
3666                 if (!in->unlinked)
3667                         ret_val = yaffs_unlink_file_if_needed(in);
3668
3669                 deleted = in->deleted;
3670
3671                 if (ret_val == YAFFS_OK && in->unlinked && !in->deleted) {
3672                         in->deleted = 1;
3673                         deleted = 1;
3674                         in->my_dev->n_deleted_files++;
3675                         yaffs_soft_del_file(in);
3676                 }
3677                 return deleted ? YAFFS_OK : YAFFS_FAIL;
3678         } else {
3679                 /* The file has no data chunks so we toss it immediately */
3680                 yaffs_free_tnode(in->my_dev, in->variant.file_variant.top);
3681                 in->variant.file_variant.top = NULL;
3682                 yaffs_generic_obj_del(in);
3683
3684                 return YAFFS_OK;
3685         }
3686 }
3687
3688 int yaffs_is_non_empty_dir(struct yaffs_obj *obj)
3689 {
3690         return (obj &&
3691                 obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY) &&
3692                 !(list_empty(&obj->variant.dir_variant.children));
3693 }
3694
3695 static int yaffs_del_dir(struct yaffs_obj *obj)
3696 {
3697         /* First check that the directory is empty. */
3698         if (yaffs_is_non_empty_dir(obj))
3699                 return YAFFS_FAIL;
3700
3701         return yaffs_generic_obj_del(obj);
3702 }
3703
3704 static int yaffs_del_symlink(struct yaffs_obj *in)
3705 {
3706         kfree(in->variant.symlink_variant.alias);
3707         in->variant.symlink_variant.alias = NULL;
3708
3709         return yaffs_generic_obj_del(in);
3710 }
3711
3712 static int yaffs_del_link(struct yaffs_obj *in)
3713 {
3714         /* remove this hardlink from the list associated with the equivalent
3715          * object
3716          */
3717         list_del_init(&in->hard_links);
3718         return yaffs_generic_obj_del(in);
3719 }
3720
3721 int yaffs_del_obj(struct yaffs_obj *obj)
3722 {
3723         int ret_val = -1;
3724
3725         switch (obj->variant_type) {
3726         case YAFFS_OBJECT_TYPE_FILE:
3727                 ret_val = yaffs_del_file(obj);
3728                 break;
3729         case YAFFS_OBJECT_TYPE_DIRECTORY:
3730                 if (!list_empty(&obj->variant.dir_variant.dirty)) {
3731                         yaffs_trace(YAFFS_TRACE_BACKGROUND,
3732                                 "Remove object %d from dirty directories",
3733                                 obj->obj_id);
3734                         list_del_init(&obj->variant.dir_variant.dirty);
3735                 }
3736                 return yaffs_del_dir(obj);
3737                 break;
3738         case YAFFS_OBJECT_TYPE_SYMLINK:
3739                 ret_val = yaffs_del_symlink(obj);
3740                 break;
3741         case YAFFS_OBJECT_TYPE_HARDLINK:
3742                 ret_val = yaffs_del_link(obj);
3743                 break;
3744         case YAFFS_OBJECT_TYPE_SPECIAL:
3745                 ret_val = yaffs_generic_obj_del(obj);
3746                 break;
3747         case YAFFS_OBJECT_TYPE_UNKNOWN:
3748                 ret_val = 0;
3749                 break;          /* should not happen. */
3750         }
3751         return ret_val;
3752 }
3753
3754
3755 static void yaffs_empty_dir_to_dir(struct yaffs_obj *from_dir,
3756                                    struct yaffs_obj *to_dir)
3757 {
3758         struct yaffs_obj *obj;
3759         struct list_head *lh;
3760         struct list_head *n;
3761
3762         list_for_each_safe(lh, n, &from_dir->variant.dir_variant.children) {
3763                 obj = list_entry(lh, struct yaffs_obj, siblings);
3764                 yaffs_add_obj_to_dir(to_dir, obj);
3765         }
3766 }
3767
3768 struct yaffs_obj *yaffs_retype_obj(struct yaffs_obj *obj,
3769                                    enum yaffs_obj_type type)
3770 {
3771         /* Tear down the old variant */
3772         switch (obj->variant_type) {
3773         case YAFFS_OBJECT_TYPE_FILE:
3774                 /* Nuke file data */
3775                 yaffs_resize_file(obj, 0);
3776                 yaffs_free_tnode(obj->my_dev, obj->variant.file_variant.top);
3777                 obj->variant.file_variant.top = NULL;
3778                 break;
3779         case YAFFS_OBJECT_TYPE_DIRECTORY:
3780                 /* Put the children in lost and found. */
3781                 yaffs_empty_dir_to_dir(obj, obj->my_dev->lost_n_found);
3782                 if (!list_empty(&obj->variant.dir_variant.dirty))
3783                         list_del_init(&obj->variant.dir_variant.dirty);
3784                 break;
3785         case YAFFS_OBJECT_TYPE_SYMLINK:
3786                 /* Nuke symplink data */
3787                 kfree(obj->variant.symlink_variant.alias);
3788                 obj->variant.symlink_variant.alias = NULL;
3789                 break;
3790         case YAFFS_OBJECT_TYPE_HARDLINK:
3791                 list_del_init(&obj->hard_links);
3792                 break;
3793         default:
3794                 break;
3795         }
3796
3797         memset(&obj->variant, 0, sizeof(obj->variant));
3798
3799         /*Set up new variant if the memset is not enough. */
3800         switch (type) {
3801         case YAFFS_OBJECT_TYPE_DIRECTORY:
3802                 INIT_LIST_HEAD(&obj->variant.dir_variant.children);
3803                 INIT_LIST_HEAD(&obj->variant.dir_variant.dirty);
3804                 break;
3805         case YAFFS_OBJECT_TYPE_FILE:
3806         case YAFFS_OBJECT_TYPE_SYMLINK:
3807         case YAFFS_OBJECT_TYPE_HARDLINK:
3808         default:
3809                 break;
3810         }
3811
3812         obj->variant_type = type;
3813
3814         return obj;
3815
3816 }
3817
3818 static int yaffs_unlink_worker(struct yaffs_obj *obj)
3819 {
3820         int del_now = 0;
3821
3822         if (!obj)
3823                 return YAFFS_FAIL;
3824
3825         if (!obj->my_inode)
3826                 del_now = 1;
3827
3828         yaffs_update_parent(obj->parent);
3829
3830         if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
3831                 return yaffs_del_link(obj);
3832         } else if (!list_empty(&obj->hard_links)) {
3833                 /* Curve ball: We're unlinking an object that has a hardlink.
3834                  *
3835                  * This problem arises because we are not strictly following
3836                  * The Linux link/inode model.
3837                  *
3838                  * We can't really delete the object.
3839                  * Instead, we do the following:
3840                  * - Select a hardlink.
3841                  * - Unhook it from the hard links
3842                  * - Move it from its parent directory so that the rename works.
3843                  * - Rename the object to the hardlink's name.
3844                  * - Delete the hardlink
3845                  */
3846
3847                 struct yaffs_obj *hl;
3848                 struct yaffs_obj *parent;
3849                 int ret_val;
3850                 YCHAR name[YAFFS_MAX_NAME_LENGTH + 1];
3851
3852                 hl = list_entry(obj->hard_links.next, struct yaffs_obj,
3853                                 hard_links);
3854
3855                 yaffs_get_obj_name(hl, name, YAFFS_MAX_NAME_LENGTH + 1);
3856                 parent = hl->parent;
3857
3858                 list_del_init(&hl->hard_links);
3859
3860                 yaffs_add_obj_to_dir(obj->my_dev->unlinked_dir, hl);
3861
3862                 ret_val = yaffs_change_obj_name(obj, parent, name, 0, 0);
3863
3864                 if (ret_val == YAFFS_OK)
3865                         ret_val = yaffs_generic_obj_del(hl);
3866
3867                 return ret_val;
3868
3869         } else if (del_now) {
3870                 switch (obj->variant_type) {
3871                 case YAFFS_OBJECT_TYPE_FILE:
3872                         return yaffs_del_file(obj);
3873                         break;
3874                 case YAFFS_OBJECT_TYPE_DIRECTORY:
3875                         list_del_init(&obj->variant.dir_variant.dirty);
3876                         return yaffs_del_dir(obj);
3877                         break;
3878                 case YAFFS_OBJECT_TYPE_SYMLINK:
3879                         return yaffs_del_symlink(obj);
3880                         break;
3881                 case YAFFS_OBJECT_TYPE_SPECIAL:
3882                         return yaffs_generic_obj_del(obj);
3883                         break;
3884                 case YAFFS_OBJECT_TYPE_HARDLINK:
3885                 case YAFFS_OBJECT_TYPE_UNKNOWN:
3886                 default:
3887                         return YAFFS_FAIL;
3888                 }
3889         } else if (yaffs_is_non_empty_dir(obj)) {
3890                 return YAFFS_FAIL;
3891         } else {
3892                 return yaffs_change_obj_name(obj, obj->my_dev->unlinked_dir,
3893                                                 _Y("unlinked"), 0, 0);
3894         }
3895 }
3896
3897 int yaffs_unlink_obj(struct yaffs_obj *obj)
3898 {
3899         if (obj && obj->unlink_allowed)
3900                 return yaffs_unlink_worker(obj);
3901
3902         return YAFFS_FAIL;
3903 }
3904
3905 int yaffs_unlinker(struct yaffs_obj *dir, const YCHAR *name)
3906 {
3907         struct yaffs_obj *obj;
3908
3909         obj = yaffs_find_by_name(dir, name);
3910         return yaffs_unlink_obj(obj);
3911 }
3912
3913 /* Note:
3914  * If old_name is NULL then we take old_dir as the object to be renamed.
3915  */
3916 int yaffs_rename_obj(struct yaffs_obj *old_dir, const YCHAR *old_name,
3917                      struct yaffs_obj *new_dir, const YCHAR *new_name)
3918 {
3919         struct yaffs_obj *obj = NULL;
3920         struct yaffs_obj *existing_target = NULL;
3921         int force = 0;
3922         int result;
3923         struct yaffs_dev *dev;
3924
3925         if (!old_dir || old_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
3926                 BUG();
3927                 return YAFFS_FAIL;
3928         }
3929         if (!new_dir || new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
3930                 BUG();
3931                 return YAFFS_FAIL;
3932         }
3933
3934         dev = old_dir->my_dev;
3935
3936 #ifdef CONFIG_YAFFS_CASE_INSENSITIVE
3937         /* Special case for case insemsitive systems.
3938          * While look-up is case insensitive, the name isn't.
3939          * Therefore we might want to change x.txt to X.txt
3940          */
3941         if (old_dir == new_dir &&
3942                 old_name && new_name &&
3943                 strcmp(old_name, new_name) == 0)
3944                 force = 1;
3945 #endif
3946
3947         if (strnlen(new_name, YAFFS_MAX_NAME_LENGTH + 1) >
3948             YAFFS_MAX_NAME_LENGTH)
3949                 /* ENAMETOOLONG */
3950                 return YAFFS_FAIL;
3951
3952         if (old_name)
3953                 obj = yaffs_find_by_name(old_dir, old_name);
3954         else{
3955                 obj = old_dir;
3956                 old_dir = obj->parent;
3957         }
3958
3959         if (obj && obj->rename_allowed) {
3960                 /* Now handle an existing target, if there is one */
3961                 existing_target = yaffs_find_by_name(new_dir, new_name);
3962                 if (yaffs_is_non_empty_dir(existing_target)) {
3963                         return YAFFS_FAIL;      /* ENOTEMPTY */
3964                 } else if (existing_target && existing_target != obj) {
3965                         /* Nuke the target first, using shadowing,
3966                          * but only if it isn't the same object.
3967                          *
3968                          * Note we must disable gc here otherwise it can mess
3969                          * up the shadowing.
3970                          *
3971                          */
3972                         dev->gc_disable = 1;
3973                         yaffs_change_obj_name(obj, new_dir, new_name, force,
3974                                               existing_target->obj_id);
3975                         existing_target->is_shadowed = 1;
3976                         yaffs_unlink_obj(existing_target);
3977                         dev->gc_disable = 0;
3978                 }
3979
3980                 result = yaffs_change_obj_name(obj, new_dir, new_name, 1, 0);
3981
3982                 yaffs_update_parent(old_dir);
3983                 if (new_dir != old_dir)
3984                         yaffs_update_parent(new_dir);
3985
3986                 return result;
3987         }
3988         return YAFFS_FAIL;
3989 }
3990
3991 /*----------------------- Initialisation Scanning ---------------------- */
3992
3993 void yaffs_handle_shadowed_obj(struct yaffs_dev *dev, int obj_id,
3994                                int backward_scanning)
3995 {
3996         struct yaffs_obj *obj;
3997
3998         if (backward_scanning) {
3999                 /* Handle YAFFS2 case (backward scanning)
4000                  * If the shadowed object exists then ignore.
4001                  */
4002                 obj = yaffs_find_by_number(dev, obj_id);
4003                 if (obj)
4004                         return;
4005         }
4006
4007         /* Let's create it (if it does not exist) assuming it is a file so that
4008          * it can do shrinking etc.
4009          * We put it in unlinked dir to be cleaned up after the scanning
4010          */
4011         obj =
4012             yaffs_find_or_create_by_number(dev, obj_id, YAFFS_OBJECT_TYPE_FILE);
4013         if (!obj)
4014                 return;
4015         obj->is_shadowed = 1;
4016         yaffs_add_obj_to_dir(dev->unlinked_dir, obj);
4017         obj->variant.file_variant.shrink_size = 0;
4018         obj->valid = 1;         /* So that we don't read any other info. */
4019 }
4020
4021 void yaffs_link_fixup(struct yaffs_dev *dev, struct list_head *hard_list)
4022 {
4023         struct list_head *lh;
4024         struct list_head *save;
4025         struct yaffs_obj *hl;
4026         struct yaffs_obj *in;
4027
4028         list_for_each_safe(lh, save, hard_list) {
4029                 hl = list_entry(lh, struct yaffs_obj, hard_links);
4030                 in = yaffs_find_by_number(dev,
4031                                         hl->variant.hardlink_variant.equiv_id);
4032
4033                 if (in) {
4034                         /* Add the hardlink pointers */
4035                         hl->variant.hardlink_variant.equiv_obj = in;
4036                         list_add(&hl->hard_links, &in->hard_links);
4037                 } else {
4038                         /* Todo Need to report/handle this better.
4039                          * Got a problem... hardlink to a non-existant object
4040                          */
4041                         hl->variant.hardlink_variant.equiv_obj = NULL;
4042                         INIT_LIST_HEAD(&hl->hard_links);
4043                 }
4044         }
4045 }
4046
4047 static void yaffs_strip_deleted_objs(struct yaffs_dev *dev)
4048 {
4049         /*
4050          *  Sort out state of unlinked and deleted objects after scanning.
4051          */
4052         struct list_head *i;
4053         struct list_head *n;
4054         struct yaffs_obj *l;
4055
4056         if (dev->read_only)
4057                 return;
4058
4059         /* Soft delete all the unlinked files */
4060         list_for_each_safe(i, n,
4061                            &dev->unlinked_dir->variant.dir_variant.children) {
4062                 l = list_entry(i, struct yaffs_obj, siblings);
4063                 yaffs_del_obj(l);
4064         }
4065
4066         list_for_each_safe(i, n, &dev->del_dir->variant.dir_variant.children) {
4067                 l = list_entry(i, struct yaffs_obj, siblings);
4068                 yaffs_del_obj(l);
4069         }
4070 }
4071
4072 /*
4073  * This code iterates through all the objects making sure that they are rooted.
4074  * Any unrooted objects are re-rooted in lost+found.
4075  * An object needs to be in one of:
4076  * - Directly under deleted, unlinked
4077  * - Directly or indirectly under root.
4078  *
4079  * Note:
4080  *  This code assumes that we don't ever change the current relationships
4081  *  between directories:
4082  *   root_dir->parent == unlinked_dir->parent == del_dir->parent == NULL
4083  *   lost-n-found->parent == root_dir
4084  *
4085  * This fixes the problem where directories might have inadvertently been
4086  * deleted leaving the object "hanging" without being rooted in the
4087  * directory tree.
4088  */
4089
4090 static int yaffs_has_null_parent(struct yaffs_dev *dev, struct yaffs_obj *obj)
4091 {
4092         return (obj == dev->del_dir ||
4093                 obj == dev->unlinked_dir || obj == dev->root_dir);
4094 }
4095
4096 static void yaffs_fix_hanging_objs(struct yaffs_dev *dev)
4097 {
4098         struct yaffs_obj *obj;
4099         struct yaffs_obj *parent;
4100         int i;
4101         struct list_head *lh;
4102         struct list_head *n;
4103         int depth_limit;
4104         int hanging;
4105
4106         if (dev->read_only)
4107                 return;
4108
4109         /* Iterate through the objects in each hash entry,
4110          * looking at each object.
4111          * Make sure it is rooted.
4112          */
4113
4114         for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
4115                 list_for_each_safe(lh, n, &dev->obj_bucket[i].list) {
4116                         obj = list_entry(lh, struct yaffs_obj, hash_link);
4117                         parent = obj->parent;
4118
4119                         if (yaffs_has_null_parent(dev, obj)) {
4120                                 /* These directories are not hanging */
4121                                 hanging = 0;
4122                         } else if (!parent ||
4123                                    parent->variant_type !=
4124                                    YAFFS_OBJECT_TYPE_DIRECTORY) {
4125                                 hanging = 1;
4126                         } else if (yaffs_has_null_parent(dev, parent)) {
4127                                 hanging = 0;
4128                         } else {
4129                                 /*
4130                                  * Need to follow the parent chain to
4131                                  * see if it is hanging.
4132                                  */
4133                                 hanging = 0;
4134                                 depth_limit = 100;
4135
4136                                 while (parent != dev->root_dir &&
4137                                        parent->parent &&
4138                                        parent->parent->variant_type ==
4139                                        YAFFS_OBJECT_TYPE_DIRECTORY &&
4140                                        depth_limit > 0) {
4141                                         parent = parent->parent;
4142                                         depth_limit--;
4143                                 }
4144                                 if (parent != dev->root_dir)
4145                                         hanging = 1;
4146                         }
4147                         if (hanging) {
4148                                 yaffs_trace(YAFFS_TRACE_SCAN,
4149                                         "Hanging object %d moved to lost and found",
4150                                         obj->obj_id);
4151                                 yaffs_add_obj_to_dir(dev->lost_n_found, obj);
4152                         }
4153                 }
4154         }
4155 }
4156
4157 /*
4158  * Delete directory contents for cleaning up lost and found.
4159  */
4160 static void yaffs_del_dir_contents(struct yaffs_obj *dir)
4161 {
4162         struct yaffs_obj *obj;
4163         struct list_head *lh;
4164         struct list_head *n;
4165
4166         if (dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
4167                 BUG();
4168
4169         list_for_each_safe(lh, n, &dir->variant.dir_variant.children) {
4170                 obj = list_entry(lh, struct yaffs_obj, siblings);
4171                 if (obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY)
4172                         yaffs_del_dir_contents(obj);
4173                 yaffs_trace(YAFFS_TRACE_SCAN,
4174                         "Deleting lost_found object %d",
4175                         obj->obj_id);
4176                 yaffs_unlink_obj(obj);
4177         }
4178 }
4179
4180 static void yaffs_empty_l_n_f(struct yaffs_dev *dev)
4181 {
4182         yaffs_del_dir_contents(dev->lost_n_found);
4183 }
4184
4185
4186 struct yaffs_obj *yaffs_find_by_name(struct yaffs_obj *directory,
4187                                      const YCHAR *name)
4188 {
4189         int sum;
4190         struct list_head *i;
4191         YCHAR buffer[YAFFS_MAX_NAME_LENGTH + 1];
4192         struct yaffs_obj *l;
4193
4194         if (!name)
4195                 return NULL;
4196
4197         if (!directory) {
4198                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4199                         "tragedy: yaffs_find_by_name: null pointer directory"
4200                         );
4201                 BUG();
4202                 return NULL;
4203         }
4204         if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4205                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4206                         "tragedy: yaffs_find_by_name: non-directory"
4207                         );
4208                 BUG();
4209         }
4210
4211         sum = yaffs_calc_name_sum(name);
4212
4213         list_for_each(i, &directory->variant.dir_variant.children) {
4214                 l = list_entry(i, struct yaffs_obj, siblings);
4215
4216                 if (l->parent != directory)
4217                         BUG();
4218
4219                 yaffs_check_obj_details_loaded(l);
4220
4221                 /* Special case for lost-n-found */
4222                 if (l->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
4223                         if (!strcmp(name, YAFFS_LOSTNFOUND_NAME))
4224                                 return l;
4225                 } else if (l->sum == sum || l->hdr_chunk <= 0) {
4226                         /* LostnFound chunk called Objxxx
4227                          * Do a real check
4228                          */
4229                         yaffs_get_obj_name(l, buffer,
4230                                 YAFFS_MAX_NAME_LENGTH + 1);
4231                         if (!strncmp(name, buffer, YAFFS_MAX_NAME_LENGTH))
4232                                 return l;
4233                 }
4234         }
4235         return NULL;
4236 }
4237
4238 /* GetEquivalentObject dereferences any hard links to get to the
4239  * actual object.
4240  */
4241
4242 struct yaffs_obj *yaffs_get_equivalent_obj(struct yaffs_obj *obj)
4243 {
4244         if (obj && obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
4245                 obj = obj->variant.hardlink_variant.equiv_obj;
4246                 yaffs_check_obj_details_loaded(obj);
4247         }
4248         return obj;
4249 }
4250
4251 /*
4252  *  A note or two on object names.
4253  *  * If the object name is missing, we then make one up in the form objnnn
4254  *
4255  *  * ASCII names are stored in the object header's name field from byte zero
4256  *  * Unicode names are historically stored starting from byte zero.
4257  *
4258  * Then there are automatic Unicode names...
4259  * The purpose of these is to save names in a way that can be read as
4260  * ASCII or Unicode names as appropriate, thus allowing a Unicode and ASCII
4261  * system to share files.
4262  *
4263  * These automatic unicode are stored slightly differently...
4264  *  - If the name can fit in the ASCII character space then they are saved as
4265  *    ascii names as per above.
4266  *  - If the name needs Unicode then the name is saved in Unicode
4267  *    starting at oh->name[1].
4268
4269  */
4270 static void yaffs_fix_null_name(struct yaffs_obj *obj, YCHAR *name,
4271                                 int buffer_size)
4272 {
4273         /* Create an object name if we could not find one. */
4274         if (strnlen(name, YAFFS_MAX_NAME_LENGTH) == 0) {
4275                 YCHAR local_name[20];
4276                 YCHAR num_string[20];
4277                 YCHAR *x = &num_string[19];
4278                 unsigned v = obj->obj_id;
4279                 num_string[19] = 0;
4280                 while (v > 0) {
4281                         x--;
4282                         *x = '0' + (v % 10);
4283                         v /= 10;
4284                 }
4285                 /* make up a name */
4286                 strcpy(local_name, YAFFS_LOSTNFOUND_PREFIX);
4287                 strcat(local_name, x);
4288                 strncpy(name, local_name, buffer_size - 1);
4289         }
4290 }
4291
4292 int yaffs_get_obj_name(struct yaffs_obj *obj, YCHAR *name, int buffer_size)
4293 {
4294         memset(name, 0, buffer_size * sizeof(YCHAR));
4295         yaffs_check_obj_details_loaded(obj);
4296         if (obj->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
4297                 strncpy(name, YAFFS_LOSTNFOUND_NAME, buffer_size - 1);
4298         } else if (obj->short_name[0]) {
4299                 strcpy(name, obj->short_name);
4300         } else if (obj->hdr_chunk > 0) {
4301                 int result;
4302                 u8 *buffer = yaffs_get_temp_buffer(obj->my_dev);
4303
4304                 struct yaffs_obj_hdr *oh = (struct yaffs_obj_hdr *)buffer;
4305
4306                 memset(buffer, 0, obj->my_dev->data_bytes_per_chunk);
4307
4308                 if (obj->hdr_chunk > 0) {
4309                         result = yaffs_rd_chunk_tags_nand(obj->my_dev,
4310                                 obj->hdr_chunk, buffer, NULL);
4311                         if (result == YAFFS_OK)
4312                                 yaffs_load_name_from_oh(obj->my_dev, name,
4313                                         oh->name, buffer_size);
4314                 }
4315                 yaffs_release_temp_buffer(obj->my_dev, buffer);
4316         }
4317
4318         yaffs_fix_null_name(obj, name, buffer_size);
4319
4320         return strnlen(name, YAFFS_MAX_NAME_LENGTH);
4321 }
4322
4323 loff_t yaffs_get_obj_length(struct yaffs_obj *obj)
4324 {
4325         /* Dereference any hard linking */
4326         obj = yaffs_get_equivalent_obj(obj);
4327
4328         if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
4329                 return obj->variant.file_variant.file_size;
4330         if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
4331                 if (!obj->variant.symlink_variant.alias)
4332                         return 0;
4333                 return strnlen(obj->variant.symlink_variant.alias,
4334                                      YAFFS_MAX_ALIAS_LENGTH);
4335         } else {
4336                 /* Only a directory should drop through to here */
4337                 return obj->my_dev->data_bytes_per_chunk;
4338         }
4339 }
4340
4341 int yaffs_get_obj_link_count(struct yaffs_obj *obj)
4342 {
4343         int count = 0;
4344         struct list_head *i;
4345
4346         if (!obj->unlinked)
4347                 count++;        /* the object itself */
4348
4349         list_for_each(i, &obj->hard_links)
4350             count++;            /* add the hard links; */
4351
4352         return count;
4353 }
4354
4355 int yaffs_get_obj_inode(struct yaffs_obj *obj)
4356 {
4357         obj = yaffs_get_equivalent_obj(obj);
4358
4359         return obj->obj_id;
4360 }
4361
4362 unsigned yaffs_get_obj_type(struct yaffs_obj *obj)
4363 {
4364         obj = yaffs_get_equivalent_obj(obj);
4365
4366         switch (obj->variant_type) {
4367         case YAFFS_OBJECT_TYPE_FILE:
4368                 return DT_REG;
4369                 break;
4370         case YAFFS_OBJECT_TYPE_DIRECTORY:
4371                 return DT_DIR;
4372                 break;
4373         case YAFFS_OBJECT_TYPE_SYMLINK:
4374                 return DT_LNK;
4375                 break;
4376         case YAFFS_OBJECT_TYPE_HARDLINK:
4377                 return DT_REG;
4378                 break;
4379         case YAFFS_OBJECT_TYPE_SPECIAL:
4380                 if (S_ISFIFO(obj->yst_mode))
4381                         return DT_FIFO;
4382                 if (S_ISCHR(obj->yst_mode))
4383                         return DT_CHR;
4384                 if (S_ISBLK(obj->yst_mode))
4385                         return DT_BLK;
4386                 if (S_ISSOCK(obj->yst_mode))
4387                         return DT_SOCK;
4388                 return DT_REG;
4389                 break;
4390         default:
4391                 return DT_REG;
4392                 break;
4393         }
4394 }
4395
4396 YCHAR *yaffs_get_symlink_alias(struct yaffs_obj *obj)
4397 {
4398         obj = yaffs_get_equivalent_obj(obj);
4399         if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK)
4400                 return yaffs_clone_str(obj->variant.symlink_variant.alias);
4401         else
4402                 return yaffs_clone_str(_Y(""));
4403 }
4404
4405 /*--------------------------- Initialisation code -------------------------- */
4406
4407 static int yaffs_check_dev_fns(struct yaffs_dev *dev)
4408 {
4409         struct yaffs_driver *drv = &dev->drv;
4410         struct yaffs_tags_handler *tagger = &dev->tagger;
4411
4412         /* Common functions, gotta have */
4413         if (!drv->drv_read_chunk_fn ||
4414             !drv->drv_write_chunk_fn ||
4415             !drv->drv_erase_fn)
4416                 return 0;
4417
4418         if (dev->param.is_yaffs2 &&
4419              (!drv->drv_mark_bad_fn  || !drv->drv_check_bad_fn))
4420                 return 0;
4421
4422         /* Install the default tags marshalling functions if needed. */
4423         yaffs_tags_compat_install(dev);
4424         yaffs_tags_marshall_install(dev);
4425
4426         /* Check we now have the marshalling functions required. */
4427         if (!tagger->write_chunk_tags_fn ||
4428             !tagger->read_chunk_tags_fn ||
4429             !tagger->query_block_fn ||
4430             !tagger->mark_bad_fn)
4431                 return 0;
4432
4433         return 1;
4434 }
4435
4436 static int yaffs_create_initial_dir(struct yaffs_dev *dev)
4437 {
4438         /* Initialise the unlinked, deleted, root and lost+found directories */
4439         dev->lost_n_found = NULL;
4440         dev->root_dir = NULL;
4441         dev->unlinked_dir = NULL;
4442         dev->del_dir = NULL;
4443
4444         dev->unlinked_dir =
4445             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_UNLINKED, S_IFDIR);
4446         dev->del_dir =
4447             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_DELETED, S_IFDIR);
4448         dev->root_dir =
4449             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_ROOT,
4450                                   YAFFS_ROOT_MODE | S_IFDIR);
4451         dev->lost_n_found =
4452             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_LOSTNFOUND,
4453                                   YAFFS_LOSTNFOUND_MODE | S_IFDIR);
4454
4455         if (dev->lost_n_found &&
4456                 dev->root_dir &&
4457                 dev->unlinked_dir &&
4458                 dev->del_dir) {
4459                         /* If lost-n-found is hidden then yank it out of the directory tree. */
4460                         if (dev->param.hide_lost_n_found)
4461                                 list_del_init(&dev->lost_n_found->siblings);
4462                         else
4463                                 yaffs_add_obj_to_dir(dev->root_dir, dev->lost_n_found);
4464                 return YAFFS_OK;
4465         }
4466         return YAFFS_FAIL;
4467 }
4468
4469 /* Low level init.
4470  * Typically only used by yaffs_guts_initialise, but also used by the
4471  * Low level yaffs driver tests.
4472  */
4473
4474 int yaffs_guts_ll_init(struct yaffs_dev *dev)
4475 {
4476
4477
4478         yaffs_trace(YAFFS_TRACE_TRACING, "yaffs: yaffs_ll_init()");
4479
4480         if (!dev) {
4481                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4482                         "yaffs: Need a device"
4483                         );
4484                 return YAFFS_FAIL;
4485         }
4486
4487         if (dev->ll_init)
4488                 return YAFFS_OK;
4489
4490         dev->internal_start_block = dev->param.start_block;
4491         dev->internal_end_block = dev->param.end_block;
4492         dev->block_offset = 0;
4493         dev->chunk_offset = 0;
4494         dev->n_free_chunks = 0;
4495
4496         dev->gc_block = 0;
4497
4498         if (dev->param.start_block == 0) {
4499                 dev->internal_start_block = dev->param.start_block + 1;
4500                 dev->internal_end_block = dev->param.end_block + 1;
4501                 dev->block_offset = 1;
4502                 dev->chunk_offset = dev->param.chunks_per_block;
4503         }
4504
4505         /* Check geometry parameters. */
4506
4507         if ((!dev->param.inband_tags && dev->param.is_yaffs2 &&
4508                 dev->param.total_bytes_per_chunk < 1024) ||
4509                 (!dev->param.is_yaffs2 &&
4510                         dev->param.total_bytes_per_chunk < 512) ||
4511                 (dev->param.inband_tags && !dev->param.is_yaffs2) ||
4512                  dev->param.chunks_per_block < 2 ||
4513                  dev->param.n_reserved_blocks < 2 ||
4514                 dev->internal_start_block <= 0 ||
4515                 dev->internal_end_block <= 0 ||
4516                 dev->internal_end_block <=
4517                 (dev->internal_start_block + dev->param.n_reserved_blocks + 2)
4518                 ) {
4519                 /* otherwise it is too small */
4520                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4521                         "NAND geometry problems: chunk size %d, type is yaffs%s, inband_tags %d ",
4522                         dev->param.total_bytes_per_chunk,
4523                         dev->param.is_yaffs2 ? "2" : "",
4524                         dev->param.inband_tags);
4525                 return YAFFS_FAIL;
4526         }
4527
4528         /* Sort out space for inband tags, if required */
4529         if (dev->param.inband_tags)
4530                 dev->data_bytes_per_chunk =
4531                     dev->param.total_bytes_per_chunk -
4532                     sizeof(struct yaffs_packed_tags2_tags_only);
4533         else
4534                 dev->data_bytes_per_chunk = dev->param.total_bytes_per_chunk;
4535
4536         /* Got the right mix of functions? */
4537         if (!yaffs_check_dev_fns(dev)) {
4538                 /* Function missing */
4539                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4540                         "device function(s) missing or wrong");
4541
4542                 return YAFFS_FAIL;
4543         }
4544
4545         if (!yaffs_init_tmp_buffers(dev))
4546                 return YAFFS_FAIL;
4547
4548         if (yaffs_init_nand(dev) != YAFFS_OK) {
4549                 yaffs_trace(YAFFS_TRACE_ALWAYS, "InitialiseNAND failed");
4550                 return YAFFS_FAIL;
4551         }
4552
4553         dev->ll_init = 1;
4554
4555         return YAFFS_OK;
4556 }
4557
4558
4559 int yaffs_guts_format_dev(struct yaffs_dev *dev)
4560 {
4561         u32 i;
4562         enum yaffs_block_state state;
4563         u32 dummy;
4564
4565         if(yaffs_guts_ll_init(dev) != YAFFS_OK)
4566                 return YAFFS_FAIL;
4567
4568         if(dev->is_mounted)
4569                 return YAFFS_FAIL;
4570
4571         for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
4572                 yaffs_query_init_block_state(dev, i, &state, &dummy);
4573                 if (state != YAFFS_BLOCK_STATE_DEAD)
4574                         yaffs_erase_block(dev, i);
4575         }
4576
4577         return YAFFS_OK;
4578 }
4579
4580 /*
4581  * If the dev is mounted r/w then the cleanup will happen during
4582  * yaffs_guts_initialise. However if the dev is mounted ro then
4583  * the cleanup will be dfered until yaffs is remounted r/w.
4584  */
4585 void yaffs_guts_cleanup(struct yaffs_dev *dev)
4586 {
4587         yaffs_strip_deleted_objs(dev);
4588         yaffs_fix_hanging_objs(dev);
4589         if (dev->param.empty_lost_n_found)
4590                         yaffs_empty_l_n_f(dev);
4591 }
4592
4593 int yaffs_guts_initialise(struct yaffs_dev *dev)
4594 {
4595         int init_failed = 0;
4596         u32 x;
4597         u32 bits;
4598
4599         if(yaffs_guts_ll_init(dev) != YAFFS_OK)
4600                 return YAFFS_FAIL;
4601
4602         if (dev->is_mounted) {
4603                 yaffs_trace(YAFFS_TRACE_ALWAYS, "device already mounted");
4604                 return YAFFS_FAIL;
4605         }
4606
4607         dev->is_mounted = 1;
4608
4609         /* OK now calculate a few things for the device */
4610
4611         /*
4612          *  Calculate all the chunk size manipulation numbers:
4613          */
4614         x = dev->data_bytes_per_chunk;
4615         /* We always use dev->chunk_shift and dev->chunk_div */
4616         dev->chunk_shift = calc_shifts(x);
4617         x >>= dev->chunk_shift;
4618         dev->chunk_div = x;
4619         /* We only use chunk mask if chunk_div is 1 */
4620         dev->chunk_mask = (1 << dev->chunk_shift) - 1;
4621
4622         /*
4623          * Calculate chunk_grp_bits.
4624          * We need to find the next power of 2 > than internal_end_block
4625          */
4626
4627         x = dev->param.chunks_per_block * (dev->internal_end_block + 1);
4628
4629         bits = calc_shifts_ceiling(x);
4630
4631         /* Set up tnode width if wide tnodes are enabled. */
4632         if (!dev->param.wide_tnodes_disabled) {
4633                 /* bits must be even so that we end up with 32-bit words */
4634                 if (bits & 1)
4635                         bits++;
4636                 if (bits < 16)
4637                         dev->tnode_width = 16;
4638                 else
4639                         dev->tnode_width = bits;
4640         } else {
4641                 dev->tnode_width = 16;
4642         }
4643
4644         dev->tnode_mask = (1 << dev->tnode_width) - 1;
4645
4646         /* Level0 Tnodes are 16 bits or wider (if wide tnodes are enabled),
4647          * so if the bitwidth of the
4648          * chunk range we're using is greater than 16 we need
4649          * to figure out chunk shift and chunk_grp_size
4650          */
4651
4652         if (bits <= dev->tnode_width)
4653                 dev->chunk_grp_bits = 0;
4654         else
4655                 dev->chunk_grp_bits = bits - dev->tnode_width;
4656
4657         dev->tnode_size = (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8;
4658         if (dev->tnode_size < sizeof(struct yaffs_tnode))
4659                 dev->tnode_size = sizeof(struct yaffs_tnode);
4660
4661         dev->chunk_grp_size = 1 << dev->chunk_grp_bits;
4662
4663         if (dev->param.chunks_per_block < dev->chunk_grp_size) {
4664                 /* We have a problem because the soft delete won't work if
4665                  * the chunk group size > chunks per block.
4666                  * This can be remedied by using larger "virtual blocks".
4667                  */
4668                 yaffs_trace(YAFFS_TRACE_ALWAYS, "chunk group too large");
4669
4670                 return YAFFS_FAIL;
4671         }
4672
4673         /* Finished verifying the device, continue with initialisation */
4674
4675         /* More device initialisation */
4676         dev->all_gcs = 0;
4677         dev->passive_gc_count = 0;
4678         dev->oldest_dirty_gc_count = 0;
4679         dev->bg_gcs = 0;
4680         dev->gc_block_finder = 0;
4681         dev->buffered_block = -1;
4682         dev->doing_buffered_block_rewrite = 0;
4683         dev->n_deleted_files = 0;
4684         dev->n_bg_deletions = 0;
4685         dev->n_unlinked_files = 0;
4686         dev->n_ecc_fixed = 0;
4687         dev->n_ecc_unfixed = 0;
4688         dev->n_tags_ecc_fixed = 0;
4689         dev->n_tags_ecc_unfixed = 0;
4690         dev->n_erase_failures = 0;
4691         dev->n_erased_blocks = 0;
4692         dev->gc_disable = 0;
4693         dev->has_pending_prioritised_gc = 1; /* Assume the worst for now,
4694                                               * will get fixed on first GC */
4695         INIT_LIST_HEAD(&dev->dirty_dirs);
4696         dev->oldest_dirty_seq = 0;
4697         dev->oldest_dirty_block = 0;
4698
4699         yaffs_endian_config(dev);
4700
4701         /* Initialise temporary caches. */
4702         dev->gc_cleanup_list = NULL;
4703
4704         if (!init_failed)
4705                 init_failed = yaffs_cache_init(dev) < 0;
4706
4707         dev->cache_hits = 0;
4708
4709         if (!init_failed) {
4710                 dev->gc_cleanup_list =
4711                     kmalloc(dev->param.chunks_per_block * sizeof(u32),
4712                                         GFP_NOFS);
4713                 if (!dev->gc_cleanup_list)
4714                         init_failed = 1;
4715         }
4716
4717         if (dev->param.is_yaffs2)
4718                 dev->param.use_header_file_size = 1;
4719
4720         if (!init_failed && !yaffs_init_blocks(dev))
4721                 init_failed = 1;
4722
4723         yaffs_init_tnodes_and_objs(dev);
4724
4725         if (!init_failed && !yaffs_create_initial_dir(dev))
4726                 init_failed = 1;
4727
4728         if (!init_failed && dev->param.is_yaffs2 &&
4729                 !dev->param.disable_summary &&
4730                 !yaffs_summary_init(dev))
4731                 init_failed = 1;
4732
4733         if (!init_failed) {
4734                 /* Now scan the flash. */
4735                 if (dev->param.is_yaffs2) {
4736                         if (yaffs2_checkpt_restore(dev)) {
4737                                 yaffs_check_obj_details_loaded(dev->root_dir);
4738                                 yaffs_trace(YAFFS_TRACE_CHECKPOINT |
4739                                         YAFFS_TRACE_MOUNT,
4740                                         "yaffs: restored from checkpoint"
4741                                         );
4742                         } else {
4743
4744                                 /* Clean up the mess caused by an aborted
4745                                  * checkpoint load then scan backwards.
4746                                  */
4747                                 yaffs_deinit_blocks(dev);
4748
4749                                 yaffs_deinit_tnodes_and_objs(dev);
4750
4751                                 dev->n_erased_blocks = 0;
4752                                 dev->n_free_chunks = 0;
4753                                 dev->alloc_block = -1;
4754                                 dev->alloc_page = -1;
4755                                 dev->n_deleted_files = 0;
4756                                 dev->n_unlinked_files = 0;
4757                                 dev->n_bg_deletions = 0;
4758
4759                                 if (!init_failed && !yaffs_init_blocks(dev))
4760                                         init_failed = 1;
4761
4762                                 yaffs_init_tnodes_and_objs(dev);
4763
4764                                 if (!init_failed
4765                                     && !yaffs_create_initial_dir(dev))
4766                                         init_failed = 1;
4767
4768                                 if (!init_failed && !yaffs2_scan_backwards(dev))
4769                                         init_failed = 1;
4770                         }
4771                 } else if (!yaffs1_scan(dev)) {
4772                         init_failed = 1;
4773                 }
4774
4775                 yaffs_guts_cleanup(dev);
4776         }
4777
4778         if (init_failed) {
4779                 /* Clean up the mess */
4780                 yaffs_trace(YAFFS_TRACE_TRACING,
4781                   "yaffs: yaffs_guts_initialise() aborted.");
4782
4783                 yaffs_deinitialise(dev);
4784                 return YAFFS_FAIL;
4785         }
4786
4787         /* Zero out stats */
4788         dev->n_page_reads = 0;
4789         dev->n_page_writes = 0;
4790         dev->n_erasures = 0;
4791         dev->n_gc_copies = 0;
4792         dev->n_retried_writes = 0;
4793
4794         dev->n_retired_blocks = 0;
4795
4796         yaffs_verify_free_chunks(dev);
4797         yaffs_verify_blocks(dev);
4798
4799         /* Clean up any aborted checkpoint data */
4800         if (!dev->is_checkpointed && dev->blocks_in_checkpt > 0)
4801                 yaffs2_checkpt_invalidate(dev);
4802
4803         yaffs_trace(YAFFS_TRACE_TRACING,
4804           "yaffs: yaffs_guts_initialise() done.");
4805         return YAFFS_OK;
4806 }
4807
4808 void yaffs_deinitialise(struct yaffs_dev *dev)
4809 {
4810         if (dev->is_mounted) {
4811                 u32 i;
4812
4813                 yaffs_deinit_blocks(dev);
4814                 yaffs_deinit_tnodes_and_objs(dev);
4815                 yaffs_summary_deinit(dev);
4816                 yaffs_cache_deinit(dev);
4817
4818                 kfree(dev->gc_cleanup_list);
4819
4820                 for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
4821                         kfree(dev->temp_buffer[i].buffer);
4822                         dev->temp_buffer[i].buffer = NULL;
4823                 }
4824
4825                 kfree(dev->checkpt_buffer);
4826                 dev->checkpt_buffer = NULL;
4827                 kfree(dev->checkpt_block_list);
4828                 dev->checkpt_block_list = NULL;
4829
4830                 dev->ll_init = 0;
4831                 dev->is_mounted = 0;
4832
4833                 yaffs_deinit_nand(dev);
4834         }
4835 }
4836
4837 int yaffs_count_free_chunks(struct yaffs_dev *dev)
4838 {
4839         int n_free = 0;
4840         u32 b;
4841         struct yaffs_block_info *blk;
4842
4843         blk = dev->block_info;
4844         for (b = dev->internal_start_block; b <= dev->internal_end_block; b++) {
4845                 switch (blk->block_state) {
4846                 case YAFFS_BLOCK_STATE_EMPTY:
4847                 case YAFFS_BLOCK_STATE_ALLOCATING:
4848                 case YAFFS_BLOCK_STATE_COLLECTING:
4849                 case YAFFS_BLOCK_STATE_FULL:
4850                         n_free +=
4851                             (dev->param.chunks_per_block - blk->pages_in_use +
4852                              blk->soft_del_pages);
4853                         break;
4854                 default:
4855                         break;
4856                 }
4857                 blk++;
4858         }
4859         return n_free;
4860 }
4861
4862 int yaffs_get_n_free_chunks(struct yaffs_dev *dev)
4863 {
4864         /* This is what we report to the outside world */
4865         int n_free;
4866         int n_dirty_caches;
4867         int blocks_for_checkpt;
4868
4869         n_free = dev->n_free_chunks;
4870         n_free += dev->n_deleted_files;
4871
4872         /* Now count and subtract the number of dirty chunks in the cache. */
4873         n_dirty_caches = yaffs_count_dirty_caches(dev);
4874         n_free -= n_dirty_caches;
4875
4876         n_free -=
4877             ((dev->param.n_reserved_blocks + 1) * dev->param.chunks_per_block);
4878
4879         /* Now figure checkpoint space and report that... */
4880         blocks_for_checkpt = yaffs_calc_checkpt_blocks_required(dev);
4881
4882         n_free -= (blocks_for_checkpt * dev->param.chunks_per_block);
4883
4884         if (n_free < 0)
4885                 n_free = 0;
4886
4887         return n_free;
4888 }
4889
4890
4891 /*
4892  * Marshalling functions to get loff_t file sizes into and out of
4893  * object headers.
4894  */
4895 void yaffs_oh_size_load(struct yaffs_dev *dev,
4896                         struct yaffs_obj_hdr *oh,
4897                         loff_t fsize,
4898                         int do_endian)
4899 {
4900         oh->file_size_low = FSIZE_LOW(fsize);
4901
4902         oh->file_size_high = FSIZE_HIGH(fsize);
4903
4904         if (do_endian) {
4905                 yaffs_do_endian_u32(dev, &oh->file_size_low);
4906                 yaffs_do_endian_u32(dev, &oh->file_size_high);
4907         }
4908 }
4909
4910 loff_t yaffs_oh_to_size(struct yaffs_dev *dev, struct yaffs_obj_hdr *oh,
4911                         int do_endian)
4912 {
4913         loff_t retval;
4914
4915
4916         if (sizeof(loff_t) >= 8 && ~(oh->file_size_high)) {
4917                 u32 low = oh->file_size_low;
4918                 u32 high = oh->file_size_high;
4919
4920                 if (do_endian) {
4921                         yaffs_do_endian_u32 (dev, &low);
4922                         yaffs_do_endian_u32 (dev, &high);
4923                 }
4924                 retval = FSIZE_COMBINE(high, low);
4925         } else {
4926                 u32 low = oh->file_size_low;
4927
4928                 if (do_endian)
4929                         yaffs_do_endian_u32(dev, &low);
4930                 retval = (loff_t)low;
4931         }
4932
4933         return retval;
4934 }
4935
4936
4937 void yaffs_count_blocks_by_state(struct yaffs_dev *dev, int bs[10])
4938 {
4939         u32 i;
4940         struct yaffs_block_info *bi;
4941         int s;
4942
4943         for(i = 0; i < 10; i++)
4944                 bs[i] = 0;
4945
4946         for(i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
4947                 bi = yaffs_get_block_info(dev, i);
4948                 s = bi->block_state;
4949                 if(s > YAFFS_BLOCK_STATE_DEAD || s < YAFFS_BLOCK_STATE_UNKNOWN)
4950                         bs[0]++;
4951                 else
4952                         bs[s]++;
4953         }
4954 }