yaffs_guts.c

   1 /*
   2  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
   3  *
   4  * Copyright (C) 2002-2010 Aleph One Ltd.
   5  *   for Toby Churchill Ltd and Brightstar Engineering
   6  *
   7  * Created by Charles Manning <charles@aleph1.co.uk>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #include "yportenv.h"
  15 #include "yaffs_trace.h"
  16
  17 #include "yaffs_guts.h"
  18 #include "yaffs_tagsvalidity.h"
  19 #include "yaffs_getblockinfo.h"
  20
  21 #include "yaffs_tagscompat.h"
  22
  23 #include "yaffs_nand.h"
  24
  25 #include "yaffs_yaffs1.h"
  26 #include "yaffs_yaffs2.h"
  27 #include "yaffs_bitmap.h"
  28 #include "yaffs_verify.h"
  29
  30 #include "yaffs_nand.h"
  31 #include "yaffs_packedtags2.h"
  32
  33 #include "yaffs_nameval.h"
  34 #include "yaffs_allocator.h"
  35
  36 #include "yaffs_attribs.h"
  37
  38 /* Note YAFFS_GC_GOOD_ENOUGH must be <= YAFFS_GC_PASSIVE_THRESHOLD */
  39 #define YAFFS_GC_GOOD_ENOUGH 2
  40 #define YAFFS_GC_PASSIVE_THRESHOLD 4
  41
  42 #include "yaffs_ecc.h"
  43
  44 /* Forward declarations */
  45
  46
  47 static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
  48                              const u8 * buffer, int n_bytes, int use_reserve);
  49
  50
  51
  52 /* Function to calculate chunk and offset */
  53
  54 static void yaffs_addr_to_chunk(struct yaffs_dev *dev, loff_t addr,
  55                                 int *chunk_out, u32 * offset_out)
  56 {
  57         int chunk;
  58         u32 offset;
  59
  60         chunk = (u32) (addr >> dev->chunk_shift);
  61
  62         if (dev->chunk_div == 1) {
  63                 /* easy power of 2 case */
  64                 offset = (u32) (addr & dev->chunk_mask);
  65         } else {
  66                 /* Non power-of-2 case */
  67
  68                 loff_t chunk_base;
  69
  70                 chunk /= dev->chunk_div;
  71
  72                 chunk_base = ((loff_t) chunk) * dev->data_bytes_per_chunk;
  73                 offset = (u32) (addr - chunk_base);
  74         }
  75
  76         *chunk_out = chunk;
  77         *offset_out = offset;
  78 }
  79
  80 /* Function to return the number of shifts for a power of 2 greater than or
  81  * equal to the given number
  82  * Note we don't try to cater for all possible numbers and this does not have to
  83  * be hellishly efficient.
  84  */
  85
  86 static u32 calc_shifts_ceiling(u32 x)
  87 {
  88         int extra_bits;
  89         int shifts;
  90
  91         shifts = extra_bits = 0;
  92
  93         while (x > 1) {
  94                 if (x & 1)
  95                         extra_bits++;
  96                 x >>= 1;
  97                 shifts++;
  98         }
  99
 100         if (extra_bits)
 101                 shifts++;
 102
 103         return shifts;
 104 }
 105
 106 /* Function to return the number of shifts to get a 1 in bit 0
 107  */
 108
 109 static u32 calc_shifts(u32 x)
 110 {
 111         u32 shifts;
 112
 113         shifts = 0;
 114
 115         if (!x)
 116                 return 0;
 117
 118         while (!(x & 1)) {
 119                 x >>= 1;
 120                 shifts++;
 121         }
 122
 123         return shifts;
 124 }
 125
 126 /*
 127  * Temporary buffer manipulations.
 128  */
 129
 130 static int yaffs_init_tmp_buffers(struct yaffs_dev *dev)
 131 {
 132         int i;
 133         u8 *buf = (u8 *) 1;
 134
 135         memset(dev->temp_buffer, 0, sizeof(dev->temp_buffer));
 136
 137         for (i = 0; buf && i < YAFFS_N_TEMP_BUFFERS; i++) {
 138                 dev->temp_buffer[i].line = 0;   /* not in use */
 139                 dev->temp_buffer[i].buffer = buf =
 140                     kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
 141         }
 142
 143         return buf ? YAFFS_OK : YAFFS_FAIL;
 144 }
 145
 146 u8 *yaffs_get_temp_buffer(struct yaffs_dev * dev, int line_no)
 147 {
 148         int i, j;
 149
 150         dev->temp_in_use++;
 151         if (dev->temp_in_use > dev->max_temp)
 152                 dev->max_temp = dev->temp_in_use;
 153
 154         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
 155                 if (dev->temp_buffer[i].line == 0) {
 156                         dev->temp_buffer[i].line = line_no;
 157                         if ((i + 1) > dev->max_temp) {
 158                                 dev->max_temp = i + 1;
 159                                 for (j = 0; j <= i; j++)
 160                                         dev->temp_buffer[j].max_line =
 161                                             dev->temp_buffer[j].line;
 162                         }
 163
 164                         return dev->temp_buffer[i].buffer;
 165                 }
 166         }
 167
 168         T(YAFFS_TRACE_BUFFERS,
 169           (TSTR("Out of temp buffers at line %d, other held by lines:"),
 170            line_no));
 171         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++)
 172                 T(YAFFS_TRACE_BUFFERS,
 173                   (TSTR(" %d "), dev->temp_buffer[i].line));
 174
 175         T(YAFFS_TRACE_BUFFERS, (TSTR(" " TENDSTR)));
 176
 177         /*
 178          * If we got here then we have to allocate an unmanaged one
 179          * This is not good.
 180          */
 181
 182         dev->unmanaged_buffer_allocs++;
 183         return kmalloc(dev->data_bytes_per_chunk, GFP_NOFS);
 184
 185 }
 186
 187 void yaffs_release_temp_buffer(struct yaffs_dev *dev, u8 * buffer, int line_no)
 188 {
 189         int i;
 190
 191         dev->temp_in_use--;
 192
 193         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
 194                 if (dev->temp_buffer[i].buffer == buffer) {
 195                         dev->temp_buffer[i].line = 0;
 196                         return;
 197                 }
 198         }
 199
 200         if (buffer) {
 201                 /* assume it is an unmanaged one. */
 202                 T(YAFFS_TRACE_BUFFERS,
 203                   (TSTR("Releasing unmanaged temp buffer in line %d" TENDSTR),
 204                    line_no));
 205                 kfree(buffer);
 206                 dev->unmanaged_buffer_deallocs++;
 207         }
 208
 209 }
 210
 211 /*
 212  * Determine if we have a managed buffer.
 213  */
 214 int yaffs_is_managed_tmp_buffer(struct yaffs_dev *dev, const u8 * buffer)
 215 {
 216         int i;
 217
 218         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
 219                 if (dev->temp_buffer[i].buffer == buffer)
 220                         return 1;
 221         }
 222
 223         for (i = 0; i < dev->param.n_caches; i++) {
 224                 if (dev->cache[i].data == buffer)
 225                         return 1;
 226         }
 227
 228         if (buffer == dev->checkpt_buffer)
 229                 return 1;
 230
 231         T(YAFFS_TRACE_ALWAYS,
 232           (TSTR("yaffs: unmaged buffer detected.\n" TENDSTR)));
 233         return 0;
 234 }
 235
 236 /*
 237  * Functions for robustisizing TODO
 238  *
 239  */
 240
 241 static void yaffs_handle_chunk_wr_ok(struct yaffs_dev *dev, int nand_chunk,
 242                                      const u8 * data,
 243                                      const struct yaffs_ext_tags *tags)
 244 {
 245         dev = dev;
 246         nand_chunk = nand_chunk;
 247         data = data;
 248         tags = tags;
 249 }
 250
 251 static void yaffs_handle_chunk_update(struct yaffs_dev *dev, int nand_chunk,
 252                                       const struct yaffs_ext_tags *tags)
 253 {
 254         dev = dev;
 255         nand_chunk = nand_chunk;
 256         tags = tags;
 257 }
 258
 259 void yaffs_handle_chunk_error(struct yaffs_dev *dev,
 260                               struct yaffs_block_info *bi)
 261 {
 262         if (!bi->gc_prioritise) {
 263                 bi->gc_prioritise = 1;
 264                 dev->has_pending_prioritised_gc = 1;
 265                 bi->chunk_error_strikes++;
 266
 267                 if (bi->chunk_error_strikes > 3) {
 268                         bi->needs_retiring = 1; /* Too many stikes, so retire this */
 269                         T(YAFFS_TRACE_ALWAYS,
 270                           (TSTR("yaffs: Block struck out" TENDSTR)));
 271
 272                 }
 273         }
 274 }
 275
 276 static void yaffs_handle_chunk_wr_error(struct yaffs_dev *dev, int nand_chunk,
 277                                         int erased_ok)
 278 {
 279         int flash_block = nand_chunk / dev->param.chunks_per_block;
 280         struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
 281
 282         yaffs_handle_chunk_error(dev, bi);
 283
 284         if (erased_ok) {
 285                 /* Was an actual write failure, so mark the block for retirement  */
 286                 bi->needs_retiring = 1;
 287                 T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
 288                   (TSTR("**>> Block %d needs retiring" TENDSTR), flash_block));
 289         }
 290
 291         /* Delete the chunk */
 292         yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
 293         yaffs_skip_rest_of_block(dev);
 294 }
 295
 296 /*
 297  * Verification code
 298  */
 299
 300 /*
 301  *  Simple hash function. Needs to have a reasonable spread
 302  */
 303
 304 static Y_INLINE int yaffs_hash_fn(int n)
 305 {
 306         n = abs(n);
 307         return n % YAFFS_NOBJECT_BUCKETS;
 308 }
 309
 310 /*
 311  * Access functions to useful fake objects.
 312  * Note that root might have a presence in NAND if permissions are set.
 313  */
 314
 315 struct yaffs_obj *yaffs_root(struct yaffs_dev *dev)
 316 {
 317         return dev->root_dir;
 318 }
 319
 320 struct yaffs_obj *yaffs_lost_n_found(struct yaffs_dev *dev)
 321 {
 322         return dev->lost_n_found;
 323 }
 324
 325 /*
 326  *  Erased NAND checking functions
 327  */
 328
 329 int yaffs_check_ff(u8 * buffer, int n_bytes)
 330 {
 331         /* Horrible, slow implementation */
 332         while (n_bytes--) {
 333                 if (*buffer != 0xFF)
 334                         return 0;
 335                 buffer++;
 336         }
 337         return 1;
 338 }
 339
 340 static int yaffs_check_chunk_erased(struct yaffs_dev *dev, int nand_chunk)
 341 {
 342         int retval = YAFFS_OK;
 343         u8 *data = yaffs_get_temp_buffer(dev, __LINE__);
 344         struct yaffs_ext_tags tags;
 345         int result;
 346
 347         result = yaffs_rd_chunk_tags_nand(dev, nand_chunk, data, &tags);
 348
 349         if (tags.ecc_result > YAFFS_ECC_RESULT_NO_ERROR)
 350                 retval = YAFFS_FAIL;
 351
 352         if (!yaffs_check_ff(data, dev->data_bytes_per_chunk) || tags.chunk_used) {
 353                 T(YAFFS_TRACE_NANDACCESS,
 354                   (TSTR("Chunk %d not erased" TENDSTR), nand_chunk));
 355                 retval = YAFFS_FAIL;
 356         }
 357
 358         yaffs_release_temp_buffer(dev, data, __LINE__);
 359
 360         return retval;
 361
 362 }
 363
 364 static int yaffs_verify_chunk_written(struct yaffs_dev *dev,
 365                                       int nand_chunk,
 366                                       const u8 * data,
 367                                       struct yaffs_ext_tags *tags)
 368 {
 369         int retval = YAFFS_OK;
 370         struct yaffs_ext_tags temp_tags;
 371         u8 *buffer = yaffs_get_temp_buffer(dev, __LINE__);
 372         int result;
 373
 374         result = yaffs_rd_chunk_tags_nand(dev, nand_chunk, buffer, &temp_tags);
 375         if (memcmp(buffer, data, dev->data_bytes_per_chunk) ||
 376             temp_tags.obj_id != tags->obj_id ||
 377             temp_tags.chunk_id != tags->chunk_id ||
 378             temp_tags.n_bytes != tags->n_bytes)
 379                 retval = YAFFS_FAIL;
 380
 381         yaffs_release_temp_buffer(dev, buffer, __LINE__);
 382
 383         return retval;
 384 }
 385
 386
 387 int yaffs_check_alloc_available(struct yaffs_dev *dev, int n_chunks)
 388 {
 389         int reserved_chunks;
 390         int reserved_blocks = dev->param.n_reserved_blocks;
 391         int checkpt_blocks;
 392
 393         checkpt_blocks = yaffs_calc_checkpt_blocks_required(dev);
 394
 395         reserved_chunks =
 396             ((reserved_blocks + checkpt_blocks) * dev->param.chunks_per_block);
 397
 398         return (dev->n_free_chunks > (reserved_chunks + n_chunks));
 399 }
 400
 401 static int yaffs_find_alloc_block(struct yaffs_dev *dev)
 402 {
 403         int i;
 404
 405         struct yaffs_block_info *bi;
 406
 407         if (dev->n_erased_blocks < 1) {
 408                 /* Hoosterman we've got a problem.
 409                  * Can't get space to gc
 410                  */
 411                 T(YAFFS_TRACE_ERROR,
 412                   (TSTR("yaffs tragedy: no more erased blocks" TENDSTR)));
 413
 414                 return -1;
 415         }
 416
 417         /* Find an empty block. */
 418
 419         for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
 420                 dev->alloc_block_finder++;
 421                 if (dev->alloc_block_finder < dev->internal_start_block
 422                     || dev->alloc_block_finder > dev->internal_end_block) {
 423                         dev->alloc_block_finder = dev->internal_start_block;
 424                 }
 425
 426                 bi = yaffs_get_block_info(dev, dev->alloc_block_finder);
 427
 428                 if (bi->block_state == YAFFS_BLOCK_STATE_EMPTY) {
 429                         bi->block_state = YAFFS_BLOCK_STATE_ALLOCATING;
 430                         dev->seq_number++;
 431                         bi->seq_number = dev->seq_number;
 432                         dev->n_erased_blocks--;
 433                         T(YAFFS_TRACE_ALLOCATE,
 434                           (TSTR("Allocated block %d, seq  %d, %d left" TENDSTR),
 435                            dev->alloc_block_finder, dev->seq_number,
 436                            dev->n_erased_blocks));
 437                         return dev->alloc_block_finder;
 438                 }
 439         }
 440
 441         T(YAFFS_TRACE_ALWAYS,
 442           (TSTR
 443            ("yaffs tragedy: no more erased blocks, but there should have been %d"
 444             TENDSTR), dev->n_erased_blocks));
 445
 446         return -1;
 447 }
 448 static int yaffs_alloc_chunk(struct yaffs_dev *dev, int use_reserver,
 449                              struct yaffs_block_info **block_ptr)
 450 {
 451         int ret_val;
 452         struct yaffs_block_info *bi;
 453
 454         if (dev->alloc_block < 0) {
 455                 /* Get next block to allocate off */
 456                 dev->alloc_block = yaffs_find_alloc_block(dev);
 457                 dev->alloc_page = 0;
 458         }
 459
 460         if (!use_reserver && !yaffs_check_alloc_available(dev, 1)) {
 461                 /* Not enough space to allocate unless we're allowed to use the reserve. */
 462                 return -1;
 463         }
 464
 465         if (dev->n_erased_blocks < dev->param.n_reserved_blocks
 466             && dev->alloc_page == 0) {
 467                 T(YAFFS_TRACE_ALLOCATE, (TSTR("Allocating reserve" TENDSTR)));
 468         }
 469
 470         /* Next page please.... */
 471         if (dev->alloc_block >= 0) {
 472                 bi = yaffs_get_block_info(dev, dev->alloc_block);
 473
 474                 ret_val = (dev->alloc_block * dev->param.chunks_per_block) +
 475                     dev->alloc_page;
 476                 bi->pages_in_use++;
 477                 yaffs_set_chunk_bit(dev, dev->alloc_block, dev->alloc_page);
 478
 479                 dev->alloc_page++;
 480
 481                 dev->n_free_chunks--;
 482
 483                 /* If the block is full set the state to full */
 484                 if (dev->alloc_page >= dev->param.chunks_per_block) {
 485                         bi->block_state = YAFFS_BLOCK_STATE_FULL;
 486                         dev->alloc_block = -1;
 487                 }
 488
 489                 if (block_ptr)
 490                         *block_ptr = bi;
 491
 492                 return ret_val;
 493         }
 494
 495         T(YAFFS_TRACE_ERROR,
 496           (TSTR("!!!!!!!!! Allocator out !!!!!!!!!!!!!!!!!" TENDSTR)));
 497
 498         return -1;
 499 }
 500
 501 static int yaffs_get_erased_chunks(struct yaffs_dev *dev)
 502 {
 503         int n;
 504
 505         n = dev->n_erased_blocks * dev->param.chunks_per_block;
 506
 507         if (dev->alloc_block > 0)
 508                 n += (dev->param.chunks_per_block - dev->alloc_page);
 509
 510         return n;
 511
 512 }
 513
 514 /*
 515  * yaffs_skip_rest_of_block() skips over the rest of the allocation block
 516  * if we don't want to write to it.
 517  */
 518 void yaffs_skip_rest_of_block(struct yaffs_dev *dev)
 519 {
 520         if (dev->alloc_block > 0) {
 521                 struct yaffs_block_info *bi =
 522                     yaffs_get_block_info(dev, dev->alloc_block);
 523                 if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING) {
 524                         bi->block_state = YAFFS_BLOCK_STATE_FULL;
 525                         dev->alloc_block = -1;
 526                 }
 527         }
 528 }
 529
 530 static int yaffs_write_new_chunk(struct yaffs_dev *dev,
 531                                  const u8 * data,
 532                                  struct yaffs_ext_tags *tags, int use_reserver)
 533 {
 534         int attempts = 0;
 535         int write_ok = 0;
 536         int chunk;
 537
 538         yaffs2_checkpt_invalidate(dev);
 539
 540         do {
 541                 struct yaffs_block_info *bi = 0;
 542                 int erased_ok = 0;
 543
 544                 chunk = yaffs_alloc_chunk(dev, use_reserver, &bi);
 545                 if (chunk < 0) {
 546                         /* no space */
 547                         break;
 548                 }
 549
 550                 /* First check this chunk is erased, if it needs
 551                  * checking.  The checking policy (unless forced
 552                  * always on) is as follows:
 553                  *
 554                  * Check the first page we try to write in a block.
 555                  * If the check passes then we don't need to check any
 556                  * more.        If the check fails, we check again...
 557                  * If the block has been erased, we don't need to check.
 558                  *
 559                  * However, if the block has been prioritised for gc,
 560                  * then we think there might be something odd about
 561                  * this block and stop using it.
 562                  *
 563                  * Rationale: We should only ever see chunks that have
 564                  * not been erased if there was a partially written
 565                  * chunk due to power loss.  This checking policy should
 566                  * catch that case with very few checks and thus save a
 567                  * lot of checks that are most likely not needed.
 568                  *
 569                  * Mods to the above
 570                  * If an erase check fails or the write fails we skip the
 571                  * rest of the block.
 572                  */
 573
 574                 /* let's give it a try */
 575                 attempts++;
 576
 577                 if (dev->param.always_check_erased)
 578                         bi->skip_erased_check = 0;
 579
 580                 if (!bi->skip_erased_check) {
 581                         erased_ok = yaffs_check_chunk_erased(dev, chunk);
 582                         if (erased_ok != YAFFS_OK) {
 583                                 T(YAFFS_TRACE_ERROR,
 584                                   (TSTR("**>> yaffs chunk %d was not erased"
 585                                         TENDSTR), chunk));
 586
 587                                 /* If not erased, delete this one,
 588                                  * skip rest of block and
 589                                  * try another chunk */
 590                                 yaffs_chunk_del(dev, chunk, 1, __LINE__);
 591                                 yaffs_skip_rest_of_block(dev);
 592                                 continue;
 593                         }
 594                 }
 595
 596                 write_ok = yaffs_wr_chunk_tags_nand(dev, chunk, data, tags);
 597
 598                 if (!bi->skip_erased_check)
 599                         write_ok =
 600                             yaffs_verify_chunk_written(dev, chunk, data, tags);
 601
 602                 if (write_ok != YAFFS_OK) {
 603                         /* Clean up aborted write, skip to next block and
 604                          * try another chunk */
 605                         yaffs_handle_chunk_wr_error(dev, chunk, erased_ok);
 606                         continue;
 607                 }
 608
 609                 bi->skip_erased_check = 1;
 610
 611                 /* Copy the data into the robustification buffer */
 612                 yaffs_handle_chunk_wr_ok(dev, chunk, data, tags);
 613
 614         } while (write_ok != YAFFS_OK &&
 615                  (yaffs_wr_attempts <= 0 || attempts <= yaffs_wr_attempts));
 616
 617         if (!write_ok)
 618                 chunk = -1;
 619
 620         if (attempts > 1) {
 621                 T(YAFFS_TRACE_ERROR,
 622                   (TSTR("**>> yaffs write required %d attempts" TENDSTR),
 623                    attempts));
 624
 625                 dev->n_retired_writes += (attempts - 1);
 626         }
 627
 628         return chunk;
 629 }
 630
 631 /*
 632  * Block retiring for handling a broken block.
 633  */
 634
 635 static void yaffs_retire_block(struct yaffs_dev *dev, int flash_block)
 636 {
 637         struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
 638
 639         yaffs2_checkpt_invalidate(dev);
 640
 641         yaffs2_clear_oldest_dirty_seq(dev, bi);
 642
 643         if (yaffs_mark_bad(dev, flash_block) != YAFFS_OK) {
 644                 if (yaffs_erase_block(dev, flash_block) != YAFFS_OK) {
 645                         T(YAFFS_TRACE_ALWAYS,
 646                           (TSTR
 647                            ("yaffs: Failed to mark bad and erase block %d"
 648                             TENDSTR), flash_block));
 649                 } else {
 650                         struct yaffs_ext_tags tags;
 651                         int chunk_id =
 652                             flash_block * dev->param.chunks_per_block;
 653
 654                         u8 *buffer = yaffs_get_temp_buffer(dev, __LINE__);
 655
 656                         memset(buffer, 0xff, dev->data_bytes_per_chunk);
 657                         yaffs_init_tags(&tags);
 658                         tags.seq_number = YAFFS_SEQUENCE_BAD_BLOCK;
 659                         if (dev->param.write_chunk_tags_fn(dev, chunk_id -
 660                                                            dev->chunk_offset,
 661                                                            buffer,
 662                                                            &tags) != YAFFS_OK)
 663                                 T(YAFFS_TRACE_ALWAYS,
 664                                   (TSTR
 665                                    ("yaffs: Failed to "
 666                                     TCONT("write bad block marker to block %d")
 667                                     TENDSTR), flash_block));
 668
 669                         yaffs_release_temp_buffer(dev, buffer, __LINE__);
 670                 }
 671         }
 672
 673         bi->block_state = YAFFS_BLOCK_STATE_DEAD;
 674         bi->gc_prioritise = 0;
 675         bi->needs_retiring = 0;
 676
 677         dev->n_retired_blocks++;
 678 }
 679
 680 /*---------------- Name handling functions ------------*/
 681
 682 static u16 yaffs_calc_name_sum(const YCHAR * name)
 683 {
 684         u16 sum = 0;
 685         u16 i = 1;
 686
 687         const YUCHAR *bname = (const YUCHAR *)name;
 688         if (bname) {
 689                 while ((*bname) && (i < (YAFFS_MAX_NAME_LENGTH / 2))) {
 690
 691                         /* 0x1f mask is case insensitive */
 692                         sum += ((*bname) & 0x1f) * i;
 693                         i++;
 694                         bname++;
 695                 }
 696         }
 697         return sum;
 698 }
 699
 700 void yaffs_set_obj_name(struct yaffs_obj *obj, const YCHAR * name)
 701 {
 702 #ifndef CONFIG_YAFFS_NO_SHORT_NAMES
 703         memset(obj->short_name, 0, sizeof(obj->short_name));
 704         if (name &&
 705                 strnlen(name, YAFFS_SHORT_NAME_LENGTH + 1) <=
 706             YAFFS_SHORT_NAME_LENGTH)
 707                 strcpy(obj->short_name, name);
 708         else
 709                 obj->short_name[0] = _Y('\0');
 710 #endif
 711         obj->sum = yaffs_calc_name_sum(name);
 712 }
 713
 714 void yaffs_set_obj_name_from_oh(struct yaffs_obj *obj,
 715                                 const struct yaffs_obj_hdr *oh)
 716 {
 717 #ifdef CONFIG_YAFFS_AUTO_UNICODE
 718         YCHAR tmp_name[YAFFS_MAX_NAME_LENGTH + 1];
 719         memset(tmp_name, 0, sizeof(tmp_name));
 720         yaffs_load_name_from_oh(obj->my_dev, tmp_name, oh->name,
 721                                 YAFFS_MAX_NAME_LENGTH + 1);
 722         yaffs_set_obj_name(obj, tmp_name);
 723 #else
 724         yaffs_set_obj_name(obj, oh->name);
 725 #endif
 726 }
 727
 728 /*-------------------- TNODES -------------------
 729
 730  * List of spare tnodes
 731  * The list is hooked together using the first pointer
 732  * in the tnode.
 733  */
 734
 735 struct yaffs_tnode *yaffs_get_tnode(struct yaffs_dev *dev)
 736 {
 737         struct yaffs_tnode *tn = yaffs_alloc_raw_tnode(dev);
 738         if (tn) {
 739                 memset(tn, 0, dev->tnode_size);
 740                 dev->n_tnodes++;
 741         }
 742
 743         dev->checkpoint_blocks_required = 0;    /* force recalculation */
 744
 745         return tn;
 746 }
 747
 748 /* FreeTnode frees up a tnode and puts it back on the free list */
 749 static void yaffs_free_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
 750 {
 751         yaffs_free_raw_tnode(dev, tn);
 752         dev->n_tnodes--;
 753         dev->checkpoint_blocks_required = 0;    /* force recalculation */
 754 }
 755
 756 static void yaffs_deinit_tnodes_and_objs(struct yaffs_dev *dev)
 757 {
 758         yaffs_deinit_raw_tnodes_and_objs(dev);
 759         dev->n_obj = 0;
 760         dev->n_tnodes = 0;
 761 }
 762
 763 void yaffs_load_tnode_0(struct yaffs_dev *dev, struct yaffs_tnode *tn,
 764                         unsigned pos, unsigned val)
 765 {
 766         u32 *map = (u32 *) tn;
 767         u32 bit_in_map;
 768         u32 bit_in_word;
 769         u32 word_in_map;
 770         u32 mask;
 771
 772         pos &= YAFFS_TNODES_LEVEL0_MASK;
 773         val >>= dev->chunk_grp_bits;
 774
 775         bit_in_map = pos * dev->tnode_width;
 776         word_in_map = bit_in_map / 32;
 777         bit_in_word = bit_in_map & (32 - 1);
 778
 779         mask = dev->tnode_mask << bit_in_word;
 780
 781         map[word_in_map] &= ~mask;
 782         map[word_in_map] |= (mask & (val << bit_in_word));
 783
 784         if (dev->tnode_width > (32 - bit_in_word)) {
 785                 bit_in_word = (32 - bit_in_word);
 786                 word_in_map++;;
 787                 mask =
 788                     dev->tnode_mask >> ( /*dev->tnode_width - */ bit_in_word);
 789                 map[word_in_map] &= ~mask;
 790                 map[word_in_map] |= (mask & (val >> bit_in_word));
 791         }
 792 }
 793
 794 u32 yaffs_get_group_base(struct yaffs_dev *dev, struct yaffs_tnode *tn,
 795                          unsigned pos)
 796 {
 797         u32 *map = (u32 *) tn;
 798         u32 bit_in_map;
 799         u32 bit_in_word;
 800         u32 word_in_map;
 801         u32 val;
 802
 803         pos &= YAFFS_TNODES_LEVEL0_MASK;
 804
 805         bit_in_map = pos * dev->tnode_width;
 806         word_in_map = bit_in_map / 32;
 807         bit_in_word = bit_in_map & (32 - 1);
 808
 809         val = map[word_in_map] >> bit_in_word;
 810
 811         if (dev->tnode_width > (32 - bit_in_word)) {
 812                 bit_in_word = (32 - bit_in_word);
 813                 word_in_map++;;
 814                 val |= (map[word_in_map] << bit_in_word);
 815         }
 816
 817         val &= dev->tnode_mask;
 818         val <<= dev->chunk_grp_bits;
 819
 820         return val;
 821 }
 822
 823 /* ------------------- End of individual tnode manipulation -----------------*/
 824
 825 /* ---------Functions to manipulate the look-up tree (made up of tnodes) ------
 826  * The look up tree is represented by the top tnode and the number of top_level
 827  * in the tree. 0 means only the level 0 tnode is in the tree.
 828  */
 829
 830 /* FindLevel0Tnode finds the level 0 tnode, if one exists. */
 831 struct yaffs_tnode *yaffs_find_tnode_0(struct yaffs_dev *dev,
 832                                        struct yaffs_file_var *file_struct,
 833                                        u32 chunk_id)
 834 {
 835         struct yaffs_tnode *tn = file_struct->top;
 836         u32 i;
 837         int required_depth;
 838         int level = file_struct->top_level;
 839
 840         dev = dev;
 841
 842         /* Check sane level and chunk Id */
 843         if (level < 0 || level > YAFFS_TNODES_MAX_LEVEL)
 844                 return NULL;
 845
 846         if (chunk_id > YAFFS_MAX_CHUNK_ID)
 847                 return NULL;
 848
 849         /* First check we're tall enough (ie enough top_level) */
 850
 851         i = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
 852         required_depth = 0;
 853         while (i) {
 854                 i >>= YAFFS_TNODES_INTERNAL_BITS;
 855                 required_depth++;
 856         }
 857
 858         if (required_depth > file_struct->top_level)
 859                 return NULL;    /* Not tall enough, so we can't find it */
 860
 861         /* Traverse down to level 0 */
 862         while (level > 0 && tn) {
 863                 tn = tn->internal[(chunk_id >>
 864                                    (YAFFS_TNODES_LEVEL0_BITS +
 865                                     (level - 1) *
 866                                     YAFFS_TNODES_INTERNAL_BITS)) &
 867                                   YAFFS_TNODES_INTERNAL_MASK];
 868                 level--;
 869         }
 870
 871         return tn;
 872 }
 873
 874 /* AddOrFindLevel0Tnode finds the level 0 tnode if it exists, otherwise first expands the tree.
 875  * This happens in two steps:
 876  *  1. If the tree isn't tall enough, then make it taller.
 877  *  2. Scan down the tree towards the level 0 tnode adding tnodes if required.
 878  *
 879  * Used when modifying the tree.
 880  *
 881  *  If the tn argument is NULL, then a fresh tnode will be added otherwise the specified tn will
 882  *  be plugged into the ttree.
 883  */
 884
 885 struct yaffs_tnode *yaffs_add_find_tnode_0(struct yaffs_dev *dev,
 886                                            struct yaffs_file_var *file_struct,
 887                                            u32 chunk_id,
 888                                            struct yaffs_tnode *passed_tn)
 889 {
 890         int required_depth;
 891         int i;
 892         int l;
 893         struct yaffs_tnode *tn;
 894
 895         u32 x;
 896
 897         /* Check sane level and page Id */
 898         if (file_struct->top_level < 0
 899             || file_struct->top_level > YAFFS_TNODES_MAX_LEVEL)
 900                 return NULL;
 901
 902         if (chunk_id > YAFFS_MAX_CHUNK_ID)
 903                 return NULL;
 904
 905         /* First check we're tall enough (ie enough top_level) */
 906
 907         x = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
 908         required_depth = 0;
 909         while (x) {
 910                 x >>= YAFFS_TNODES_INTERNAL_BITS;
 911                 required_depth++;
 912         }
 913
 914         if (required_depth > file_struct->top_level) {
 915                 /* Not tall enough, gotta make the tree taller */
 916                 for (i = file_struct->top_level; i < required_depth; i++) {
 917
 918                         tn = yaffs_get_tnode(dev);
 919
 920                         if (tn) {
 921                                 tn->internal[0] = file_struct->top;
 922                                 file_struct->top = tn;
 923                                 file_struct->top_level++;
 924                         } else {
 925                                 T(YAFFS_TRACE_ERROR,
 926                                   (TSTR("yaffs: no more tnodes" TENDSTR)));
 927                                 return NULL;
 928                         }
 929                 }
 930         }
 931
 932         /* Traverse down to level 0, adding anything we need */
 933
 934         l = file_struct->top_level;
 935         tn = file_struct->top;
 936
 937         if (l > 0) {
 938                 while (l > 0 && tn) {
 939                         x = (chunk_id >>
 940                              (YAFFS_TNODES_LEVEL0_BITS +
 941                               (l - 1) * YAFFS_TNODES_INTERNAL_BITS)) &
 942                             YAFFS_TNODES_INTERNAL_MASK;
 943
 944                         if ((l > 1) && !tn->internal[x]) {
 945                                 /* Add missing non-level-zero tnode */
 946                                 tn->internal[x] = yaffs_get_tnode(dev);
 947                                 if (!tn->internal[x])
 948                                         return NULL;
 949                         } else if (l == 1) {
 950                                 /* Looking from level 1 at level 0 */
 951                                 if (passed_tn) {
 952                                         /* If we already have one, then release it. */
 953                                         if (tn->internal[x])
 954                                                 yaffs_free_tnode(dev,
 955                                                                  tn->
 956                                                                  internal[x]);
 957                                         tn->internal[x] = passed_tn;
 958
 959                                 } else if (!tn->internal[x]) {
 960                                         /* Don't have one, none passed in */
 961                                         tn->internal[x] = yaffs_get_tnode(dev);
 962                                         if (!tn->internal[x])
 963                                                 return NULL;
 964                                 }
 965                         }
 966
 967                         tn = tn->internal[x];
 968                         l--;
 969                 }
 970         } else {
 971                 /* top is level 0 */
 972                 if (passed_tn) {
 973                         memcpy(tn, passed_tn,
 974                                (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8);
 975                         yaffs_free_tnode(dev, passed_tn);
 976                 }
 977         }
 978
 979         return tn;
 980 }
 981
 982 static int yaffs_tags_match(const struct yaffs_ext_tags *tags, int obj_id,
 983                             int chunk_obj)
 984 {
 985         return (tags->chunk_id == chunk_obj &&
 986                 tags->obj_id == obj_id && !tags->is_deleted) ? 1 : 0;
 987
 988 }
 989
 990 static int yaffs_find_chunk_in_group(struct yaffs_dev *dev, int the_chunk,
 991                                      struct yaffs_ext_tags *tags, int obj_id,
 992                                      int inode_chunk)
 993 {
 994         int j;
 995
 996         for (j = 0; the_chunk && j < dev->chunk_grp_size; j++) {
 997                 if (yaffs_check_chunk_bit
 998                     (dev, the_chunk / dev->param.chunks_per_block,
 999                      the_chunk % dev->param.chunks_per_block)) {
1000
1001                         if (dev->chunk_grp_size == 1)
1002                                 return the_chunk;
1003                         else {
1004                                 yaffs_rd_chunk_tags_nand(dev, the_chunk, NULL,
1005                                                          tags);
1006                                 if (yaffs_tags_match(tags, obj_id, inode_chunk)) {
1007                                         /* found it; */
1008                                         return the_chunk;
1009                                 }
1010                         }
1011                 }
1012                 the_chunk++;
1013         }
1014         return -1;
1015 }
1016
1017 static int yaffs_find_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
1018                                     struct yaffs_ext_tags *tags)
1019 {
1020         /*Get the Tnode, then get the level 0 offset chunk offset */
1021         struct yaffs_tnode *tn;
1022         int the_chunk = -1;
1023         struct yaffs_ext_tags local_tags;
1024         int ret_val = -1;
1025
1026         struct yaffs_dev *dev = in->my_dev;
1027
1028         if (!tags) {
1029                 /* Passed a NULL, so use our own tags space */
1030                 tags = &local_tags;
1031         }
1032
1033         tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
1034
1035         if (tn) {
1036                 the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
1037
1038                 ret_val =
1039                     yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
1040                                               inode_chunk);
1041         }
1042         return ret_val;
1043 }
1044
1045 static int yaffs_find_del_file_chunk(struct yaffs_obj *in, int inode_chunk,
1046                                      struct yaffs_ext_tags *tags)
1047 {
1048         /* Get the Tnode, then get the level 0 offset chunk offset */
1049         struct yaffs_tnode *tn;
1050         int the_chunk = -1;
1051         struct yaffs_ext_tags local_tags;
1052
1053         struct yaffs_dev *dev = in->my_dev;
1054         int ret_val = -1;
1055
1056         if (!tags) {
1057                 /* Passed a NULL, so use our own tags space */
1058                 tags = &local_tags;
1059         }
1060
1061         tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
1062
1063         if (tn) {
1064
1065                 the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
1066
1067                 ret_val =
1068                     yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
1069                                               inode_chunk);
1070
1071                 /* Delete the entry in the filestructure (if found) */
1072                 if (ret_val != -1)
1073                         yaffs_load_tnode_0(dev, tn, inode_chunk, 0);
1074         }
1075
1076         return ret_val;
1077 }
1078
1079 int yaffs_put_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
1080                             int nand_chunk, int in_scan)
1081 {
1082         /* NB in_scan is zero unless scanning.
1083          * For forward scanning, in_scan is > 0;
1084          * for backward scanning in_scan is < 0
1085          *
1086          * nand_chunk = 0 is a dummy insert to make sure the tnodes are there.
1087          */
1088
1089         struct yaffs_tnode *tn;
1090         struct yaffs_dev *dev = in->my_dev;
1091         int existing_cunk;
1092         struct yaffs_ext_tags existing_tags;
1093         struct yaffs_ext_tags new_tags;
1094         unsigned existing_serial, new_serial;
1095
1096         if (in->variant_type != YAFFS_OBJECT_TYPE_FILE) {
1097                 /* Just ignore an attempt at putting a chunk into a non-file during scanning
1098                  * If it is not during Scanning then something went wrong!
1099                  */
1100                 if (!in_scan) {
1101                         T(YAFFS_TRACE_ERROR,
1102                           (TSTR
1103                            ("yaffs tragedy:attempt to put data chunk into a non-file"
1104                             TENDSTR)));
1105                         YBUG();
1106                 }
1107
1108                 yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
1109                 return YAFFS_OK;
1110         }
1111
1112         tn = yaffs_add_find_tnode_0(dev,
1113                                     &in->variant.file_variant,
1114                                     inode_chunk, NULL);
1115         if (!tn)
1116                 return YAFFS_FAIL;
1117
1118         if (!nand_chunk)
1119                 /* Dummy insert, bail now */
1120                 return YAFFS_OK;
1121
1122         existing_cunk = yaffs_get_group_base(dev, tn, inode_chunk);
1123
1124         if (in_scan != 0) {
1125                 /* If we're scanning then we need to test for duplicates
1126                  * NB This does not need to be efficient since it should only ever
1127                  * happen when the power fails during a write, then only one
1128                  * chunk should ever be affected.
1129                  *
1130                  * Correction for YAFFS2: This could happen quite a lot and we need to think about efficiency! TODO
1131                  * Update: For backward scanning we don't need to re-read tags so this is quite cheap.
1132                  */
1133
1134                 if (existing_cunk > 0) {
1135                         /* NB Right now existing chunk will not be real chunk_id if the chunk group size > 1
1136                          *    thus we have to do a FindChunkInFile to get the real chunk id.
1137                          *
1138                          * We have a duplicate now we need to decide which one to use:
1139                          *
1140                          * Backwards scanning YAFFS2: The old one is what we use, dump the new one.
1141                          * Forward scanning YAFFS2: The new one is what we use, dump the old one.
1142                          * YAFFS1: Get both sets of tags and compare serial numbers.
1143                          */
1144
1145                         if (in_scan > 0) {
1146                                 /* Only do this for forward scanning */
1147                                 yaffs_rd_chunk_tags_nand(dev,
1148                                                          nand_chunk,
1149                                                          NULL, &new_tags);
1150
1151                                 /* Do a proper find */
1152                                 existing_cunk =
1153                                     yaffs_find_chunk_in_file(in, inode_chunk,
1154                                                              &existing_tags);
1155                         }
1156
1157                         if (existing_cunk <= 0) {
1158                                 /*Hoosterman - how did this happen? */
1159
1160                                 T(YAFFS_TRACE_ERROR,
1161                                   (TSTR
1162                                    ("yaffs tragedy: existing chunk < 0 in scan"
1163                                     TENDSTR)));
1164
1165                         }
1166
1167                         /* NB The deleted flags should be false, otherwise the chunks will
1168                          * not be loaded during a scan
1169                          */
1170
1171                         if (in_scan > 0) {
1172                                 new_serial = new_tags.serial_number;
1173                                 existing_serial = existing_tags.serial_number;
1174                         }
1175
1176                         if ((in_scan > 0) &&
1177                             (existing_cunk <= 0 ||
1178                              ((existing_serial + 1) & 3) == new_serial)) {
1179                                 /* Forward scanning.
1180                                  * Use new
1181                                  * Delete the old one and drop through to update the tnode
1182                                  */
1183                                 yaffs_chunk_del(dev, existing_cunk, 1,
1184                                                 __LINE__);
1185                         } else {
1186                                 /* Backward scanning or we want to use the existing one
1187                                  * Use existing.
1188                                  * Delete the new one and return early so that the tnode isn't changed
1189                                  */
1190                                 yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
1191                                 return YAFFS_OK;
1192                         }
1193                 }
1194
1195         }
1196
1197         if (existing_cunk == 0)
1198                 in->n_data_chunks++;
1199
1200         yaffs_load_tnode_0(dev, tn, inode_chunk, nand_chunk);
1201
1202         return YAFFS_OK;
1203 }
1204
1205 static void yaffs_soft_del_chunk(struct yaffs_dev *dev, int chunk)
1206 {
1207         struct yaffs_block_info *the_block;
1208         unsigned block_no;
1209
1210         T(YAFFS_TRACE_DELETION, (TSTR("soft delete chunk %d" TENDSTR), chunk));
1211
1212         block_no = chunk / dev->param.chunks_per_block;
1213         the_block = yaffs_get_block_info(dev, block_no);
1214         if (the_block) {
1215                 the_block->soft_del_pages++;
1216                 dev->n_free_chunks++;
1217                 yaffs2_update_oldest_dirty_seq(dev, block_no, the_block);
1218         }
1219 }
1220
1221 /* SoftDeleteWorker scans backwards through the tnode tree and soft deletes all the chunks in the file.
1222  * All soft deleting does is increment the block's softdelete count and pulls the chunk out
1223  * of the tnode.
1224  * Thus, essentially this is the same as DeleteWorker except that the chunks are soft deleted.
1225  */
1226
1227 static int yaffs_soft_del_worker(struct yaffs_obj *in, struct yaffs_tnode *tn,
1228                                  u32 level, int chunk_offset)
1229 {
1230         int i;
1231         int the_chunk;
1232         int all_done = 1;
1233         struct yaffs_dev *dev = in->my_dev;
1234
1235         if (tn) {
1236                 if (level > 0) {
1237
1238                         for (i = YAFFS_NTNODES_INTERNAL - 1; all_done && i >= 0;
1239                              i--) {
1240                                 if (tn->internal[i]) {
1241                                         all_done =
1242                                             yaffs_soft_del_worker(in,
1243                                                                   tn->internal
1244                                                                   [i],
1245                                                                   level - 1,
1246                                                                   (chunk_offset
1247                                                                    <<
1248                                                                    YAFFS_TNODES_INTERNAL_BITS)
1249                                                                   + i);
1250                                         if (all_done) {
1251                                                 yaffs_free_tnode(dev,
1252                                                                  tn->internal
1253                                                                  [i]);
1254                                                 tn->internal[i] = NULL;
1255                                         } else {
1256                                                 /* Hoosterman... how could this happen? */
1257                                         }
1258                                 }
1259                         }
1260                         return (all_done) ? 1 : 0;
1261                 } else if (level == 0) {
1262
1263                         for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0; i--) {
1264                                 the_chunk = yaffs_get_group_base(dev, tn, i);
1265                                 if (the_chunk) {
1266                                         /* Note this does not find the real chunk, only the chunk group.
1267                                          * We make an assumption that a chunk group is not larger than
1268                                          * a block.
1269                                          */
1270                                         yaffs_soft_del_chunk(dev, the_chunk);
1271                                         yaffs_load_tnode_0(dev, tn, i, 0);
1272                                 }
1273
1274                         }
1275                         return 1;
1276
1277                 }
1278
1279         }
1280
1281         return 1;
1282
1283 }
1284
1285 static void yaffs_remove_obj_from_dir(struct yaffs_obj *obj)
1286 {
1287         struct yaffs_dev *dev = obj->my_dev;
1288         struct yaffs_obj *parent;
1289
1290         yaffs_verify_obj_in_dir(obj);
1291         parent = obj->parent;
1292
1293         yaffs_verify_dir(parent);
1294
1295         if (dev && dev->param.remove_obj_fn)
1296                 dev->param.remove_obj_fn(obj);
1297
1298         list_del_init(&obj->siblings);
1299         obj->parent = NULL;
1300
1301         yaffs_verify_dir(parent);
1302 }
1303
1304 void yaffs_add_obj_to_dir(struct yaffs_obj *directory, struct yaffs_obj *obj)
1305 {
1306         if (!directory) {
1307                 T(YAFFS_TRACE_ALWAYS,
1308                   (TSTR
1309                    ("tragedy: Trying to add an object to a null pointer directory"
1310                     TENDSTR)));
1311                 YBUG();
1312                 return;
1313         }
1314         if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
1315                 T(YAFFS_TRACE_ALWAYS,
1316                   (TSTR
1317                    ("tragedy: Trying to add an object to a non-directory"
1318                     TENDSTR)));
1319                 YBUG();
1320         }
1321
1322         if (obj->siblings.prev == NULL) {
1323                 /* Not initialised */
1324                 YBUG();
1325         }
1326
1327         yaffs_verify_dir(directory);
1328
1329         yaffs_remove_obj_from_dir(obj);
1330
1331         /* Now add it */
1332         list_add(&obj->siblings, &directory->variant.dir_variant.children);
1333         obj->parent = directory;
1334
1335         if (directory == obj->my_dev->unlinked_dir
1336             || directory == obj->my_dev->del_dir) {
1337                 obj->unlinked = 1;
1338                 obj->my_dev->n_unlinked_files++;
1339                 obj->rename_allowed = 0;
1340         }
1341
1342         yaffs_verify_dir(directory);
1343         yaffs_verify_obj_in_dir(obj);
1344 }
1345
1346 static int yaffs_change_obj_name(struct yaffs_obj *obj,
1347                                  struct yaffs_obj *new_dir,
1348                                  const YCHAR * new_name, int force, int shadows)
1349 {
1350         int unlink_op;
1351         int del_op;
1352
1353         struct yaffs_obj *existing_target;
1354
1355         if (new_dir == NULL)
1356                 new_dir = obj->parent;  /* use the old directory */
1357
1358         if (new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
1359                 T(YAFFS_TRACE_ALWAYS,
1360                   (TSTR
1361                    ("tragedy: yaffs_change_obj_name: new_dir is not a directory"
1362                     TENDSTR)));
1363                 YBUG();
1364         }
1365
1366         /* TODO: Do we need this different handling for YAFFS2 and YAFFS1?? */
1367         if (obj->my_dev->param.is_yaffs2)
1368                 unlink_op = (new_dir == obj->my_dev->unlinked_dir);
1369         else
1370                 unlink_op = (new_dir == obj->my_dev->unlinked_dir
1371                              && obj->variant_type == YAFFS_OBJECT_TYPE_FILE);
1372
1373         del_op = (new_dir == obj->my_dev->del_dir);
1374
1375         existing_target = yaffs_find_by_name(new_dir, new_name);
1376
1377         /* If the object is a file going into the unlinked directory,
1378          *   then it is OK to just stuff it in since duplicate names are allowed.
1379          *   else only proceed if the new name does not exist and if we're putting
1380          *   it into a directory.
1381          */
1382         if ((unlink_op ||
1383              del_op ||
1384              force ||
1385              (shadows > 0) ||
1386              !existing_target) &&
1387             new_dir->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY) {
1388                 yaffs_set_obj_name(obj, new_name);
1389                 obj->dirty = 1;
1390
1391                 yaffs_add_obj_to_dir(new_dir, obj);
1392
1393                 if (unlink_op)
1394                         obj->unlinked = 1;
1395
1396                 /* If it is a deletion then we mark it as a shrink for gc purposes. */
1397                 if (yaffs_update_oh(obj, new_name, 0, del_op, shadows, NULL) >=
1398                     0)
1399                         return YAFFS_OK;
1400         }
1401
1402         return YAFFS_FAIL;
1403 }
1404
1405 /*------------------------ Short Operations Cache ----------------------------------------
1406  *   In many situations where there is no high level buffering  a lot of
1407  *   reads might be short sequential reads, and a lot of writes may be short
1408  *   sequential writes. eg. scanning/writing a jpeg file.
1409  *   In these cases, a short read/write cache can provide a huge perfomance
1410  *   benefit with dumb-as-a-rock code.
1411  *   In Linux, the page cache provides read buffering and the short op cache
1412  *   provides write buffering.
1413  *
1414  *   There are a limited number (~10) of cache chunks per device so that we don't
1415  *   need a very intelligent search.
1416  */
1417
1418 static int yaffs_obj_cache_dirty(struct yaffs_obj *obj)
1419 {
1420         struct yaffs_dev *dev = obj->my_dev;
1421         int i;
1422         struct yaffs_cache *cache;
1423         int n_caches = obj->my_dev->param.n_caches;
1424
1425         for (i = 0; i < n_caches; i++) {
1426                 cache = &dev->cache[i];
1427                 if (cache->object == obj && cache->dirty)
1428                         return 1;
1429         }
1430
1431         return 0;
1432 }
1433
1434 static void yaffs_flush_file_cache(struct yaffs_obj *obj)
1435 {
1436         struct yaffs_dev *dev = obj->my_dev;
1437         int lowest = -99;       /* Stop compiler whining. */
1438         int i;
1439         struct yaffs_cache *cache;
1440         int chunk_written = 0;
1441         int n_caches = obj->my_dev->param.n_caches;
1442
1443         if (n_caches > 0) {
1444                 do {
1445                         cache = NULL;
1446
1447                         /* Find the dirty cache for this object with the lowest chunk id. */
1448                         for (i = 0; i < n_caches; i++) {
1449                                 if (dev->cache[i].object == obj &&
1450                                     dev->cache[i].dirty) {
1451                                         if (!cache
1452                                             || dev->cache[i].chunk_id <
1453                                             lowest) {
1454                                                 cache = &dev->cache[i];
1455                                                 lowest = cache->chunk_id;
1456                                         }
1457                                 }
1458                         }
1459
1460                         if (cache && !cache->locked) {
1461                                 /* Write it out and free it up */
1462
1463                                 chunk_written =
1464                                     yaffs_wr_data_obj(cache->object,
1465                                                       cache->chunk_id,
1466                                                       cache->data,
1467                                                       cache->n_bytes, 1);
1468                                 cache->dirty = 0;
1469                                 cache->object = NULL;
1470                         }
1471
1472                 } while (cache && chunk_written > 0);
1473
1474                 if (cache) {
1475                         /* Hoosterman, disk full while writing cache out. */
1476                         T(YAFFS_TRACE_ERROR,
1477                           (TSTR
1478                            ("yaffs tragedy: no space during cache write"
1479                             TENDSTR)));
1480
1481                 }
1482         }
1483
1484 }
1485
1486 /*yaffs_flush_whole_cache(dev)
1487  *
1488  *
1489  */
1490
1491 void yaffs_flush_whole_cache(struct yaffs_dev *dev)
1492 {
1493         struct yaffs_obj *obj;
1494         int n_caches = dev->param.n_caches;
1495         int i;
1496
1497         /* Find a dirty object in the cache and flush it...
1498          * until there are no further dirty objects.
1499          */
1500         do {
1501                 obj = NULL;
1502                 for (i = 0; i < n_caches && !obj; i++) {
1503                         if (dev->cache[i].object && dev->cache[i].dirty)
1504                                 obj = dev->cache[i].object;
1505
1506                 }
1507                 if (obj)
1508                         yaffs_flush_file_cache(obj);
1509
1510         } while (obj);
1511
1512 }
1513
1514 /* Grab us a cache chunk for use.
1515  * First look for an empty one.
1516  * Then look for the least recently used non-dirty one.
1517  * Then look for the least recently used dirty one...., flush and look again.
1518  */
1519 static struct yaffs_cache *yaffs_grab_chunk_worker(struct yaffs_dev *dev)
1520 {
1521         int i;
1522
1523         if (dev->param.n_caches > 0) {
1524                 for (i = 0; i < dev->param.n_caches; i++) {
1525                         if (!dev->cache[i].object)
1526                                 return &dev->cache[i];
1527                 }
1528         }
1529
1530         return NULL;
1531 }
1532
1533 static struct yaffs_cache *yaffs_grab_chunk_cache(struct yaffs_dev *dev)
1534 {
1535         struct yaffs_cache *cache;
1536         struct yaffs_obj *the_obj;
1537         int usage;
1538         int i;
1539         int pushout;
1540
1541         if (dev->param.n_caches > 0) {
1542                 /* Try find a non-dirty one... */
1543
1544                 cache = yaffs_grab_chunk_worker(dev);
1545
1546                 if (!cache) {
1547                         /* They were all dirty, find the last recently used object and flush
1548                          * its cache, then  find again.
1549                          * NB what's here is not very accurate, we actually flush the object
1550                          * the last recently used page.
1551                          */
1552
1553                         /* With locking we can't assume we can use entry zero */
1554
1555                         the_obj = NULL;
1556                         usage = -1;
1557                         cache = NULL;
1558                         pushout = -1;
1559
1560                         for (i = 0; i < dev->param.n_caches; i++) {
1561                                 if (dev->cache[i].object &&
1562                                     !dev->cache[i].locked &&
1563                                     (dev->cache[i].last_use < usage
1564                                      || !cache)) {
1565                                         usage = dev->cache[i].last_use;
1566                                         the_obj = dev->cache[i].object;
1567                                         cache = &dev->cache[i];
1568                                         pushout = i;
1569                                 }
1570                         }
1571
1572                         if (!cache || cache->dirty) {
1573                                 /* Flush and try again */
1574                                 yaffs_flush_file_cache(the_obj);
1575                                 cache = yaffs_grab_chunk_worker(dev);
1576                         }
1577
1578                 }
1579                 return cache;
1580         } else {
1581                 return NULL;
1582         }
1583 }
1584
1585 /* Find a cached chunk */
1586 static struct yaffs_cache *yaffs_find_chunk_cache(const struct yaffs_obj *obj,
1587                                                   int chunk_id)
1588 {
1589         struct yaffs_dev *dev = obj->my_dev;
1590         int i;
1591         if (dev->param.n_caches > 0) {
1592                 for (i = 0; i < dev->param.n_caches; i++) {
1593                         if (dev->cache[i].object == obj &&
1594                             dev->cache[i].chunk_id == chunk_id) {
1595                                 dev->cache_hits++;
1596
1597                                 return &dev->cache[i];
1598                         }
1599                 }
1600         }
1601         return NULL;
1602 }
1603
1604 /* Mark the chunk for the least recently used algorithym */
1605 static void yaffs_use_cache(struct yaffs_dev *dev, struct yaffs_cache *cache,
1606                             int is_write)
1607 {
1608
1609         if (dev->param.n_caches > 0) {
1610                 if (dev->cache_last_use < 0 || dev->cache_last_use > 100000000) {
1611                         /* Reset the cache usages */
1612                         int i;
1613                         for (i = 1; i < dev->param.n_caches; i++)
1614                                 dev->cache[i].last_use = 0;
1615
1616                         dev->cache_last_use = 0;
1617                 }
1618
1619                 dev->cache_last_use++;
1620
1621                 cache->last_use = dev->cache_last_use;
1622
1623                 if (is_write)
1624                         cache->dirty = 1;
1625         }
1626 }
1627
1628 /* Invalidate a single cache page.
1629  * Do this when a whole page gets written,
1630  * ie the short cache for this page is no longer valid.
1631  */
1632 static void yaffs_invalidate_chunk_cache(struct yaffs_obj *object, int chunk_id)
1633 {
1634         if (object->my_dev->param.n_caches > 0) {
1635                 struct yaffs_cache *cache =
1636                     yaffs_find_chunk_cache(object, chunk_id);
1637
1638                 if (cache)
1639                         cache->object = NULL;
1640         }
1641 }
1642
1643 /* Invalidate all the cache pages associated with this object
1644  * Do this whenever ther file is deleted or resized.
1645  */
1646 static void yaffs_invalidate_whole_cache(struct yaffs_obj *in)
1647 {
1648         int i;
1649         struct yaffs_dev *dev = in->my_dev;
1650
1651         if (dev->param.n_caches > 0) {
1652                 /* Invalidate it. */
1653                 for (i = 0; i < dev->param.n_caches; i++) {
1654                         if (dev->cache[i].object == in)
1655                                 dev->cache[i].object = NULL;
1656                 }
1657         }
1658 }
1659
1660 static void yaffs_unhash_obj(struct yaffs_obj *obj)
1661 {
1662         int bucket;
1663         struct yaffs_dev *dev = obj->my_dev;
1664
1665         /* If it is still linked into the bucket list, free from the list */
1666         if (!list_empty(&obj->hash_link)) {
1667                 list_del_init(&obj->hash_link);
1668                 bucket = yaffs_hash_fn(obj->obj_id);
1669                 dev->obj_bucket[bucket].count--;
1670         }
1671 }
1672
1673 /*  FreeObject frees up a Object and puts it back on the free list */
1674 static void yaffs_free_obj(struct yaffs_obj *obj)
1675 {
1676         struct yaffs_dev *dev = obj->my_dev;
1677
1678         T(YAFFS_TRACE_OS,
1679           (TSTR("FreeObject %p inode %p" TENDSTR), obj, obj->my_inode));
1680
1681         if (!obj)
1682                 YBUG();
1683         if (obj->parent)
1684                 YBUG();
1685         if (!list_empty(&obj->siblings))
1686                 YBUG();
1687
1688         if (obj->my_inode) {
1689                 /* We're still hooked up to a cached inode.
1690                  * Don't delete now, but mark for later deletion
1691                  */
1692                 obj->defered_free = 1;
1693                 return;
1694         }
1695
1696         yaffs_unhash_obj(obj);
1697
1698         yaffs_free_raw_obj(dev, obj);
1699         dev->n_obj--;
1700         dev->checkpoint_blocks_required = 0;    /* force recalculation */
1701 }
1702
1703 void yaffs_handle_defered_free(struct yaffs_obj *obj)
1704 {
1705         if (obj->defered_free)
1706                 yaffs_free_obj(obj);
1707 }
1708
1709 static int yaffs_generic_obj_del(struct yaffs_obj *in)
1710 {
1711
1712         /* First off, invalidate the file's data in the cache, without flushing. */
1713         yaffs_invalidate_whole_cache(in);
1714
1715         if (in->my_dev->param.is_yaffs2 && (in->parent != in->my_dev->del_dir)) {
1716                 /* Move to the unlinked directory so we have a record that it was deleted. */
1717                 yaffs_change_obj_name(in, in->my_dev->del_dir, _Y("deleted"), 0,
1718                                       0);
1719
1720         }
1721
1722         yaffs_remove_obj_from_dir(in);
1723         yaffs_chunk_del(in->my_dev, in->hdr_chunk, 1, __LINE__);
1724         in->hdr_chunk = 0;
1725
1726         yaffs_free_obj(in);
1727         return YAFFS_OK;
1728
1729 }
1730
1731 static void yaffs_soft_del_file(struct yaffs_obj *obj)
1732 {
1733         if (obj->deleted &&
1734             obj->variant_type == YAFFS_OBJECT_TYPE_FILE && !obj->soft_del) {
1735                 if (obj->n_data_chunks <= 0) {
1736                         /* Empty file with no duplicate object headers, just delete it immediately */
1737                         yaffs_free_tnode(obj->my_dev,
1738                                          obj->variant.file_variant.top);
1739                         obj->variant.file_variant.top = NULL;
1740                         T(YAFFS_TRACE_TRACING,
1741                           (TSTR("yaffs: Deleting empty file %d" TENDSTR),
1742                            obj->obj_id));
1743                         yaffs_generic_obj_del(obj);
1744                 } else {
1745                         yaffs_soft_del_worker(obj,
1746                                               obj->variant.file_variant.top,
1747                                               obj->variant.
1748                                               file_variant.top_level, 0);
1749                         obj->soft_del = 1;
1750                 }
1751         }
1752 }
1753
1754 /* Pruning removes any part of the file structure tree that is beyond the
1755  * bounds of the file (ie that does not point to chunks).
1756  *
1757  * A file should only get pruned when its size is reduced.
1758  *
1759  * Before pruning, the chunks must be pulled from the tree and the
1760  * level 0 tnode entries must be zeroed out.
1761  * Could also use this for file deletion, but that's probably better handled
1762  * by a special case.
1763  *
1764  * This function is recursive. For levels > 0 the function is called again on
1765  * any sub-tree. For level == 0 we just check if the sub-tree has data.
1766  * If there is no data in a subtree then it is pruned.
1767  */
1768
1769 static struct yaffs_tnode *yaffs_prune_worker(struct yaffs_dev *dev,
1770                                               struct yaffs_tnode *tn, u32 level,
1771                                               int del0)
1772 {
1773         int i;
1774         int has_data;
1775
1776         if (tn) {
1777                 has_data = 0;
1778
1779                 if (level > 0) {
1780                         for (i = 0; i < YAFFS_NTNODES_INTERNAL; i++) {
1781                                 if (tn->internal[i]) {
1782                                         tn->internal[i] =
1783                                             yaffs_prune_worker(dev,
1784                                                                tn->internal[i],
1785                                                                level - 1,
1786                                                                (i ==
1787                                                                 0) ? del0 : 1);
1788                                 }
1789
1790                                 if (tn->internal[i])
1791                                         has_data++;
1792                         }
1793                 } else {
1794                         int tnode_size_u32 = dev->tnode_size / sizeof(u32);
1795                         u32 *map = (u32 *) tn;
1796
1797                         for (i = 0; !has_data && i < tnode_size_u32; i++) {
1798                                 if (map[i])
1799                                         has_data++;
1800                         }
1801                 }
1802
1803                 if (has_data == 0 && del0) {
1804                         /* Free and return NULL */
1805
1806                         yaffs_free_tnode(dev, tn);
1807                         tn = NULL;
1808                 }
1809
1810         }
1811
1812         return tn;
1813
1814 }
1815
1816 static int yaffs_prune_tree(struct yaffs_dev *dev,
1817                             struct yaffs_file_var *file_struct)
1818 {
1819         int i;
1820         int has_data;
1821         int done = 0;
1822         struct yaffs_tnode *tn;
1823
1824         if (file_struct->top_level > 0) {
1825                 file_struct->top =
1826                     yaffs_prune_worker(dev, file_struct->top,
1827                                        file_struct->top_level, 0);
1828
1829                 /* Now we have a tree with all the non-zero branches NULL but the height
1830                  * is the same as it was.
1831                  * Let's see if we can trim internal tnodes to shorten the tree.
1832                  * We can do this if only the 0th element in the tnode is in use
1833                  * (ie all the non-zero are NULL)
1834                  */
1835
1836                 while (file_struct->top_level && !done) {
1837                         tn = file_struct->top;
1838
1839                         has_data = 0;
1840                         for (i = 1; i < YAFFS_NTNODES_INTERNAL; i++) {
1841                                 if (tn->internal[i])
1842                                         has_data++;
1843                         }
1844
1845                         if (!has_data) {
1846                                 file_struct->top = tn->internal[0];
1847                                 file_struct->top_level--;
1848                                 yaffs_free_tnode(dev, tn);
1849                         } else {
1850                                 done = 1;
1851                         }
1852                 }
1853         }
1854
1855         return YAFFS_OK;
1856 }
1857
1858 /*-------------------- End of File Structure functions.-------------------*/
1859
1860 /* AllocateEmptyObject gets us a clean Object. Tries to make allocate more if we run out */
1861 static struct yaffs_obj *yaffs_alloc_empty_obj(struct yaffs_dev *dev)
1862 {
1863         struct yaffs_obj *obj = yaffs_alloc_raw_obj(dev);
1864
1865         if (obj) {
1866                 dev->n_obj++;
1867
1868                 /* Now sweeten it up... */
1869
1870                 memset(obj, 0, sizeof(struct yaffs_obj));
1871                 obj->being_created = 1;
1872
1873                 obj->my_dev = dev;
1874                 obj->hdr_chunk = 0;
1875                 obj->variant_type = YAFFS_OBJECT_TYPE_UNKNOWN;
1876                 INIT_LIST_HEAD(&(obj->hard_links));
1877                 INIT_LIST_HEAD(&(obj->hash_link));
1878                 INIT_LIST_HEAD(&obj->siblings);
1879
1880                 /* Now make the directory sane */
1881                 if (dev->root_dir) {
1882                         obj->parent = dev->root_dir;
1883                         list_add(&(obj->siblings),
1884                                  &dev->root_dir->variant.dir_variant.children);
1885                 }
1886
1887                 /* Add it to the lost and found directory.
1888                  * NB Can't put root or lost-n-found in lost-n-found so
1889                  * check if lost-n-found exists first
1890                  */
1891                 if (dev->lost_n_found)
1892                         yaffs_add_obj_to_dir(dev->lost_n_found, obj);
1893
1894                 obj->being_created = 0;
1895         }
1896
1897         dev->checkpoint_blocks_required = 0;    /* force recalculation */
1898
1899         return obj;
1900 }
1901
1902 static int yaffs_find_nice_bucket(struct yaffs_dev *dev)
1903 {
1904         int i;
1905         int l = 999;
1906         int lowest = 999999;
1907
1908         /* Search for the shortest list or one that
1909          * isn't too long.
1910          */
1911
1912         for (i = 0; i < 10 && lowest > 4; i++) {
1913                 dev->bucket_finder++;
1914                 dev->bucket_finder %= YAFFS_NOBJECT_BUCKETS;
1915                 if (dev->obj_bucket[dev->bucket_finder].count < lowest) {
1916                         lowest = dev->obj_bucket[dev->bucket_finder].count;
1917                         l = dev->bucket_finder;
1918                 }
1919
1920         }
1921
1922         return l;
1923 }
1924
1925 static int yaffs_new_obj_id(struct yaffs_dev *dev)
1926 {
1927         int bucket = yaffs_find_nice_bucket(dev);
1928
1929         /* Now find an object value that has not already been taken
1930          * by scanning the list.
1931          */
1932
1933         int found = 0;
1934         struct list_head *i;
1935
1936         u32 n = (u32) bucket;
1937
1938         /* yaffs_check_obj_hash_sane();  */
1939
1940         while (!found) {
1941                 found = 1;
1942                 n += YAFFS_NOBJECT_BUCKETS;
1943                 if (1 || dev->obj_bucket[bucket].count > 0) {
1944                         list_for_each(i, &dev->obj_bucket[bucket].list) {
1945                                 /* If there is already one in the list */
1946                                 if (i && list_entry(i, struct yaffs_obj,
1947                                                     hash_link)->obj_id == n) {
1948                                         found = 0;
1949                                 }
1950                         }
1951                 }
1952         }
1953
1954         return n;
1955 }
1956
1957 static void yaffs_hash_obj(struct yaffs_obj *in)
1958 {
1959         int bucket = yaffs_hash_fn(in->obj_id);
1960         struct yaffs_dev *dev = in->my_dev;
1961
1962         list_add(&in->hash_link, &dev->obj_bucket[bucket].list);
1963         dev->obj_bucket[bucket].count++;
1964 }
1965
1966 struct yaffs_obj *yaffs_find_by_number(struct yaffs_dev *dev, u32 number)
1967 {
1968         int bucket = yaffs_hash_fn(number);
1969         struct list_head *i;
1970         struct yaffs_obj *in;
1971
1972         list_for_each(i, &dev->obj_bucket[bucket].list) {
1973                 /* Look if it is in the list */
1974                 if (i) {
1975                         in = list_entry(i, struct yaffs_obj, hash_link);
1976                         if (in->obj_id == number) {
1977
1978                                 /* Don't tell the VFS about this one if it is defered free */
1979                                 if (in->defered_free)
1980                                         return NULL;
1981
1982                                 return in;
1983                         }
1984                 }
1985         }
1986
1987         return NULL;
1988 }
1989
1990 struct yaffs_obj *yaffs_new_obj(struct yaffs_dev *dev, int number,
1991                                 enum yaffs_obj_type type)
1992 {
1993         struct yaffs_obj *the_obj = NULL;
1994         struct yaffs_tnode *tn = NULL;
1995
1996         if (number < 0)
1997                 number = yaffs_new_obj_id(dev);
1998
1999         if (type == YAFFS_OBJECT_TYPE_FILE) {
2000                 tn = yaffs_get_tnode(dev);
2001                 if (!tn)
2002                         return NULL;
2003         }
2004
2005         the_obj = yaffs_alloc_empty_obj(dev);
2006         if (!the_obj) {
2007                 if (tn)
2008                         yaffs_free_tnode(dev, tn);
2009                 return NULL;
2010         }
2011
2012         if (the_obj) {
2013                 the_obj->fake = 0;
2014                 the_obj->rename_allowed = 1;
2015                 the_obj->unlink_allowed = 1;
2016                 the_obj->obj_id = number;
2017                 yaffs_hash_obj(the_obj);
2018                 the_obj->variant_type = type;
2019                 yaffs_load_current_time(the_obj, 1, 1);
2020
2021                 switch (type) {
2022                 case YAFFS_OBJECT_TYPE_FILE:
2023                         the_obj->variant.file_variant.file_size = 0;
2024                         the_obj->variant.file_variant.scanned_size = 0;
2025                         the_obj->variant.file_variant.shrink_size = ~0; /* max */
2026                         the_obj->variant.file_variant.top_level = 0;
2027                         the_obj->variant.file_variant.top = tn;
2028                         break;
2029                 case YAFFS_OBJECT_TYPE_DIRECTORY:
2030                         INIT_LIST_HEAD(&the_obj->variant.dir_variant.children);
2031                         INIT_LIST_HEAD(&the_obj->variant.dir_variant.dirty);
2032                         break;
2033                 case YAFFS_OBJECT_TYPE_SYMLINK:
2034                 case YAFFS_OBJECT_TYPE_HARDLINK:
2035                 case YAFFS_OBJECT_TYPE_SPECIAL:
2036                         /* No action required */
2037                         break;
2038                 case YAFFS_OBJECT_TYPE_UNKNOWN:
2039                         /* todo this should not happen */
2040                         break;
2041                 }
2042         }
2043
2044         return the_obj;
2045 }
2046
2047 static struct yaffs_obj *yaffs_create_fake_dir(struct yaffs_dev *dev,
2048                                                int number, u32 mode)
2049 {
2050
2051         struct yaffs_obj *obj =
2052             yaffs_new_obj(dev, number, YAFFS_OBJECT_TYPE_DIRECTORY);
2053         if (obj) {
2054                 obj->fake = 1;  /* it is fake so it might have no NAND presence... */
2055                 obj->rename_allowed = 0;        /* ... and we're not allowed to rename it... */
2056                 obj->unlink_allowed = 0;        /* ... or unlink it */
2057                 obj->deleted = 0;
2058                 obj->unlinked = 0;
2059                 obj->yst_mode = mode;
2060                 obj->my_dev = dev;
2061                 obj->hdr_chunk = 0;     /* Not a valid chunk. */
2062         }
2063
2064         return obj;
2065
2066 }
2067
2068
2069 static void yaffs_init_tnodes_and_objs(struct yaffs_dev *dev)
2070 {
2071         int i;
2072
2073         dev->n_obj = 0;
2074         dev->n_tnodes = 0;
2075
2076         yaffs_init_raw_tnodes_and_objs(dev);
2077
2078         for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
2079                 INIT_LIST_HEAD(&dev->obj_bucket[i].list);
2080                 dev->obj_bucket[i].count = 0;
2081         }
2082 }
2083
2084 struct yaffs_obj *yaffs_find_or_create_by_number(struct yaffs_dev *dev,
2085                                                  int number,
2086                                                  enum yaffs_obj_type type)
2087 {
2088         struct yaffs_obj *the_obj = NULL;
2089
2090         if (number > 0)
2091                 the_obj = yaffs_find_by_number(dev, number);
2092
2093         if (!the_obj)
2094                 the_obj = yaffs_new_obj(dev, number, type);
2095
2096         return the_obj;
2097
2098 }
2099
2100 YCHAR *yaffs_clone_str(const YCHAR * str)
2101 {
2102         YCHAR *new_str = NULL;
2103         int len;
2104
2105         if (!str)
2106                 str = _Y("");
2107
2108         len = strnlen(str, YAFFS_MAX_ALIAS_LENGTH);
2109         new_str = kmalloc((len + 1) * sizeof(YCHAR), GFP_NOFS);
2110         if (new_str) {
2111                 strncpy(new_str, str, len);
2112                 new_str[len] = 0;
2113         }
2114         return new_str;
2115
2116 }
2117 /*
2118  *yaffs_update_parent() handles fixing a directories mtime and ctime when a new
2119  * link (ie. name) is created or deleted in the directory.
2120  *
2121  * ie.
2122  *   create dir/a : update dir's mtime/ctime
2123  *   rm dir/a:   update dir's mtime/ctime
2124  *   modify dir/a: don't update dir's mtimme/ctime
2125  *
2126  * This can be handled immediately or defered. Defering helps reduce the number
2127  * of updates when many files in a directory are changed within a brief period.
2128  *
2129  * If the directory updating is defered then yaffs_update_dirty_dirs must be
2130  * called periodically.
2131  */
2132
2133 static void yaffs_update_parent(struct yaffs_obj *obj)
2134 {
2135         struct yaffs_dev *dev;
2136         if (!obj)
2137                 return;
2138         dev = obj->my_dev;
2139         obj->dirty = 1;
2140         yaffs_load_current_time(obj, 0, 1);
2141         if (dev->param.defered_dir_update) {
2142                 struct list_head *link = &obj->variant.dir_variant.dirty;
2143
2144                 if (list_empty(link)) {
2145                         list_add(link, &dev->dirty_dirs);
2146                         T(YAFFS_TRACE_BACKGROUND,
2147                           (TSTR("Added object %d to dirty directories" TENDSTR),
2148                            obj->obj_id));
2149                 }
2150
2151         } else {
2152                 yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
2153         }
2154 }
2155
2156 void yaffs_update_dirty_dirs(struct yaffs_dev *dev)
2157 {
2158         struct list_head *link;
2159         struct yaffs_obj *obj;
2160         struct yaffs_dir_var *d_s;
2161         union yaffs_obj_var *o_v;
2162
2163         T(YAFFS_TRACE_BACKGROUND, (TSTR("Update dirty directories" TENDSTR)));
2164
2165         while (!list_empty(&dev->dirty_dirs)) {
2166                 link = dev->dirty_dirs.next;
2167                 list_del_init(link);
2168
2169                 d_s = list_entry(link, struct yaffs_dir_var, dirty);
2170                 o_v = list_entry(d_s, union yaffs_obj_var, dir_variant);
2171                 obj = list_entry(o_v, struct yaffs_obj, variant);
2172
2173                 T(YAFFS_TRACE_BACKGROUND,
2174                   (TSTR("Update directory %d" TENDSTR), obj->obj_id));
2175
2176                 if (obj->dirty)
2177                         yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
2178         }
2179 }
2180
2181 /*
2182  * Mknod (create) a new object.
2183  * equiv_obj only has meaning for a hard link;
2184  * alias_str only has meaning for a symlink.
2185  * rdev only has meaning for devices (a subset of special objects)
2186  */
2187
2188 static struct yaffs_obj *yaffs_create_obj(enum yaffs_obj_type type,
2189                                           struct yaffs_obj *parent,
2190                                           const YCHAR * name,
2191                                           u32 mode,
2192                                           u32 uid,
2193                                           u32 gid,
2194                                           struct yaffs_obj *equiv_obj,
2195                                           const YCHAR * alias_str, u32 rdev)
2196 {
2197         struct yaffs_obj *in;
2198         YCHAR *str = NULL;
2199
2200         struct yaffs_dev *dev = parent->my_dev;
2201
2202         /* Check if the entry exists. If it does then fail the call since we don't want a dup. */
2203         if (yaffs_find_by_name(parent, name))
2204                 return NULL;
2205
2206         if (type == YAFFS_OBJECT_TYPE_SYMLINK) {
2207                 str = yaffs_clone_str(alias_str);
2208                 if (!str)
2209                         return NULL;
2210         }
2211
2212         in = yaffs_new_obj(dev, -1, type);
2213
2214         if (!in) {
2215                 if (str)
2216                         kfree(str);
2217                 return NULL;
2218         }
2219
2220         if (in) {
2221                 in->hdr_chunk = 0;
2222                 in->valid = 1;
2223                 in->variant_type = type;
2224
2225                 in->yst_mode = mode;
2226
2227                 yaffs_attribs_init(in, gid, uid, rdev);
2228
2229                 in->n_data_chunks = 0;
2230
2231                 yaffs_set_obj_name(in, name);
2232                 in->dirty = 1;
2233
2234                 yaffs_add_obj_to_dir(parent, in);
2235
2236                 in->my_dev = parent->my_dev;
2237
2238                 switch (type) {
2239                 case YAFFS_OBJECT_TYPE_SYMLINK:
2240                         in->variant.symlink_variant.alias = str;
2241                         break;
2242                 case YAFFS_OBJECT_TYPE_HARDLINK:
2243                         in->variant.hardlink_variant.equiv_obj = equiv_obj;
2244                         in->variant.hardlink_variant.equiv_id =
2245                             equiv_obj->obj_id;
2246                         list_add(&in->hard_links, &equiv_obj->hard_links);
2247                         break;
2248                 case YAFFS_OBJECT_TYPE_FILE:
2249                 case YAFFS_OBJECT_TYPE_DIRECTORY:
2250                 case YAFFS_OBJECT_TYPE_SPECIAL:
2251                 case YAFFS_OBJECT_TYPE_UNKNOWN:
2252                         /* do nothing */
2253                         break;
2254                 }
2255
2256                 if (yaffs_update_oh(in, name, 0, 0, 0, NULL) < 0) {
2257                         /* Could not create the object header, fail the creation */
2258                         yaffs_del_obj(in);
2259                         in = NULL;
2260                 }
2261
2262                 yaffs_update_parent(parent);
2263         }
2264
2265         return in;
2266 }
2267
2268 struct yaffs_obj *yaffs_create_file(struct yaffs_obj *parent,
2269                                     const YCHAR * name, u32 mode, u32 uid,
2270                                     u32 gid)
2271 {
2272         return yaffs_create_obj(YAFFS_OBJECT_TYPE_FILE, parent, name, mode,
2273                                 uid, gid, NULL, NULL, 0);
2274 }
2275
2276 struct yaffs_obj *yaffs_create_dir(struct yaffs_obj *parent, const YCHAR * name,
2277                                    u32 mode, u32 uid, u32 gid)
2278 {
2279         return yaffs_create_obj(YAFFS_OBJECT_TYPE_DIRECTORY, parent, name,
2280                                 mode, uid, gid, NULL, NULL, 0);
2281 }
2282
2283 struct yaffs_obj *yaffs_create_special(struct yaffs_obj *parent,
2284                                        const YCHAR * name, u32 mode, u32 uid,
2285                                        u32 gid, u32 rdev)
2286 {
2287         return yaffs_create_obj(YAFFS_OBJECT_TYPE_SPECIAL, parent, name, mode,
2288                                 uid, gid, NULL, NULL, rdev);
2289 }
2290
2291 struct yaffs_obj *yaffs_create_symlink(struct yaffs_obj *parent,
2292                                        const YCHAR * name, u32 mode, u32 uid,
2293                                        u32 gid, const YCHAR * alias)
2294 {
2295         return yaffs_create_obj(YAFFS_OBJECT_TYPE_SYMLINK, parent, name, mode,
2296                                 uid, gid, NULL, alias, 0);
2297 }
2298
2299 /* yaffs_link_obj returns the object id of the equivalent object.*/
2300 struct yaffs_obj *yaffs_link_obj(struct yaffs_obj *parent, const YCHAR * name,
2301                                  struct yaffs_obj *equiv_obj)
2302 {
2303         /* Get the real object in case we were fed a hard link as an equivalent object */
2304         equiv_obj = yaffs_get_equivalent_obj(equiv_obj);
2305
2306         if (yaffs_create_obj
2307             (YAFFS_OBJECT_TYPE_HARDLINK, parent, name, 0, 0, 0,
2308              equiv_obj, NULL, 0)) {
2309                 return equiv_obj;
2310         } else {
2311                 return NULL;
2312         }
2313
2314 }
2315
2316
2317
2318 /*------------------------- Block Management and Page Allocation ----------------*/
2319
2320 static int yaffs_init_blocks(struct yaffs_dev *dev)
2321 {
2322         int n_blocks = dev->internal_end_block - dev->internal_start_block + 1;
2323
2324         dev->block_info = NULL;
2325         dev->chunk_bits = NULL;
2326
2327         dev->alloc_block = -1;  /* force it to get a new one */
2328
2329         /* If the first allocation strategy fails, thry the alternate one */
2330         dev->block_info =
2331                 kmalloc(n_blocks * sizeof(struct yaffs_block_info), GFP_NOFS);
2332         if (!dev->block_info) {
2333                 dev->block_info =
2334                     vmalloc(n_blocks * sizeof(struct yaffs_block_info));
2335                 dev->block_info_alt = 1;
2336         } else {
2337                 dev->block_info_alt = 0;
2338         }
2339
2340         if (dev->block_info) {
2341                 /* Set up dynamic blockinfo stuff. Round up bytes. */
2342                 dev->chunk_bit_stride = (dev->param.chunks_per_block + 7) / 8;
2343                 dev->chunk_bits =
2344                         kmalloc(dev->chunk_bit_stride * n_blocks, GFP_NOFS);
2345                 if (!dev->chunk_bits) {
2346                         dev->chunk_bits =
2347                             vmalloc(dev->chunk_bit_stride * n_blocks);
2348                         dev->chunk_bits_alt = 1;
2349                 } else {
2350                         dev->chunk_bits_alt = 0;
2351                 }
2352         }
2353
2354         if (dev->block_info && dev->chunk_bits) {
2355                 memset(dev->block_info, 0,
2356                        n_blocks * sizeof(struct yaffs_block_info));
2357                 memset(dev->chunk_bits, 0, dev->chunk_bit_stride * n_blocks);
2358                 return YAFFS_OK;
2359         }
2360
2361         return YAFFS_FAIL;
2362 }
2363
2364 static void yaffs_deinit_blocks(struct yaffs_dev *dev)
2365 {
2366         if (dev->block_info_alt && dev->block_info)
2367                 vfree(dev->block_info);
2368         else if (dev->block_info)
2369                 kfree(dev->block_info);
2370
2371         dev->block_info_alt = 0;
2372
2373         dev->block_info = NULL;
2374
2375         if (dev->chunk_bits_alt && dev->chunk_bits)
2376                 vfree(dev->chunk_bits);
2377         else if (dev->chunk_bits)
2378                 kfree(dev->chunk_bits);
2379         dev->chunk_bits_alt = 0;
2380         dev->chunk_bits = NULL;
2381 }
2382
2383 void yaffs_block_became_dirty(struct yaffs_dev *dev, int block_no)
2384 {
2385         struct yaffs_block_info *bi = yaffs_get_block_info(dev, block_no);
2386
2387         int erased_ok = 0;
2388
2389         /* If the block is still healthy erase it and mark as clean.
2390          * If the block has had a data failure, then retire it.
2391          */
2392
2393         T(YAFFS_TRACE_GC | YAFFS_TRACE_ERASE,
2394           (TSTR("yaffs_block_became_dirty block %d state %d %s" TENDSTR),
2395            block_no, bi->block_state,
2396            (bi->needs_retiring) ? "needs retiring" : ""));
2397
2398         yaffs2_clear_oldest_dirty_seq(dev, bi);
2399
2400         bi->block_state = YAFFS_BLOCK_STATE_DIRTY;
2401
2402         /* If this is the block being garbage collected then stop gc'ing this block */
2403         if (block_no == dev->gc_block)
2404                 dev->gc_block = 0;
2405
2406         /* If this block is currently the best candidate for gc then drop as a candidate */
2407         if (block_no == dev->gc_dirtiest) {
2408                 dev->gc_dirtiest = 0;
2409                 dev->gc_pages_in_use = 0;
2410         }
2411
2412         if (!bi->needs_retiring) {
2413                 yaffs2_checkpt_invalidate(dev);
2414                 erased_ok = yaffs_erase_block(dev, block_no);
2415                 if (!erased_ok) {
2416                         dev->n_erase_failures++;
2417                         T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2418                           (TSTR("**>> Erasure failed %d" TENDSTR), block_no));
2419                 }
2420         }
2421
2422         if (erased_ok &&
2423             ((yaffs_trace_mask & YAFFS_TRACE_ERASE)
2424              || !yaffs_skip_verification(dev))) {
2425                 int i;
2426                 for (i = 0; i < dev->param.chunks_per_block; i++) {
2427                         if (!yaffs_check_chunk_erased
2428                             (dev, block_no * dev->param.chunks_per_block + i)) {
2429                                 T(YAFFS_TRACE_ERROR,
2430                                   (TSTR
2431                                    (">>Block %d erasure supposedly OK, but chunk %d not erased"
2432                                     TENDSTR), block_no, i));
2433                         }
2434                 }
2435         }
2436
2437         if (erased_ok) {
2438                 /* Clean it up... */
2439                 bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
2440                 bi->seq_number = 0;
2441                 dev->n_erased_blocks++;
2442                 bi->pages_in_use = 0;
2443                 bi->soft_del_pages = 0;
2444                 bi->has_shrink_hdr = 0;
2445                 bi->skip_erased_check = 1;      /* This is clean, so no need to check */
2446                 bi->gc_prioritise = 0;
2447                 yaffs_clear_chunk_bits(dev, block_no);
2448
2449                 T(YAFFS_TRACE_ERASE,
2450                   (TSTR("Erased block %d" TENDSTR), block_no));
2451         } else {
2452                 dev->n_free_chunks -= dev->param.chunks_per_block;      /* We lost a block of free space */
2453
2454                 yaffs_retire_block(dev, block_no);
2455                 T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2456                   (TSTR("**>> Block %d retired" TENDSTR), block_no));
2457         }
2458 }
2459
2460
2461
2462 static int yaffs_gc_block(struct yaffs_dev *dev, int block, int whole_block)
2463 {
2464         int old_chunk;
2465         int new_chunk;
2466         int mark_flash;
2467         int ret_val = YAFFS_OK;
2468         int i;
2469         int is_checkpt_block;
2470         int matching_chunk;
2471         int max_copies;
2472
2473         int chunks_before = yaffs_get_erased_chunks(dev);
2474         int chunks_after;
2475
2476         struct yaffs_ext_tags tags;
2477
2478         struct yaffs_block_info *bi = yaffs_get_block_info(dev, block);
2479
2480         struct yaffs_obj *object;
2481
2482         is_checkpt_block = (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT);
2483
2484         T(YAFFS_TRACE_TRACING,
2485           (TSTR
2486            ("Collecting block %d, in use %d, shrink %d, whole_block %d"
2487             TENDSTR), block, bi->pages_in_use, bi->has_shrink_hdr,
2488            whole_block));
2489
2490         /*yaffs_verify_free_chunks(dev); */
2491
2492         if (bi->block_state == YAFFS_BLOCK_STATE_FULL)
2493                 bi->block_state = YAFFS_BLOCK_STATE_COLLECTING;
2494
2495         bi->has_shrink_hdr = 0; /* clear the flag so that the block can erase */
2496
2497         dev->gc_disable = 1;
2498
2499         if (is_checkpt_block || !yaffs_still_some_chunks(dev, block)) {
2500                 T(YAFFS_TRACE_TRACING,
2501                   (TSTR
2502                    ("Collecting block %d that has no chunks in use" TENDSTR),
2503                    block));
2504                 yaffs_block_became_dirty(dev, block);
2505         } else {
2506
2507                 u8 *buffer = yaffs_get_temp_buffer(dev, __LINE__);
2508
2509                 yaffs_verify_blk(dev, bi, block);
2510
2511                 max_copies = (whole_block) ? dev->param.chunks_per_block : 5;
2512                 old_chunk = block * dev->param.chunks_per_block + dev->gc_chunk;
2513
2514                 for ( /* init already done */ ;
2515                      ret_val == YAFFS_OK &&
2516                      dev->gc_chunk < dev->param.chunks_per_block &&
2517                      (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) &&
2518                      max_copies > 0; dev->gc_chunk++, old_chunk++) {
2519                         if (yaffs_check_chunk_bit(dev, block, dev->gc_chunk)) {
2520
2521                                 /* This page is in use and might need to be copied off */
2522
2523                                 max_copies--;
2524
2525                                 mark_flash = 1;
2526
2527                                 yaffs_init_tags(&tags);
2528
2529                                 yaffs_rd_chunk_tags_nand(dev, old_chunk,
2530                                                          buffer, &tags);
2531
2532                                 object = yaffs_find_by_number(dev, tags.obj_id);
2533
2534                                 T(YAFFS_TRACE_GC_DETAIL,
2535                                   (TSTR
2536                                    ("Collecting chunk in block %d, %d %d %d "
2537                                     TENDSTR), dev->gc_chunk, tags.obj_id,
2538                                    tags.chunk_id, tags.n_bytes));
2539
2540                                 if (object && !yaffs_skip_verification(dev)) {
2541                                         if (tags.chunk_id == 0)
2542                                                 matching_chunk =
2543                                                     object->hdr_chunk;
2544                                         else if (object->soft_del)
2545                                                 matching_chunk = old_chunk;     /* Defeat the test */
2546                                         else
2547                                                 matching_chunk =
2548                                                     yaffs_find_chunk_in_file
2549                                                     (object, tags.chunk_id,
2550                                                      NULL);
2551
2552                                         if (old_chunk != matching_chunk)
2553                                                 T(YAFFS_TRACE_ERROR,
2554                                                   (TSTR
2555                                                    ("gc: page in gc mismatch: %d %d %d %d"
2556                                                     TENDSTR), old_chunk,
2557                                                    matching_chunk, tags.obj_id,
2558                                                    tags.chunk_id));
2559
2560                                 }
2561
2562                                 if (!object) {
2563                                         T(YAFFS_TRACE_ERROR,
2564                                           (TSTR
2565                                            ("page %d in gc has no object: %d %d %d "
2566                                             TENDSTR), old_chunk,
2567                                            tags.obj_id, tags.chunk_id,
2568                                            tags.n_bytes));
2569                                 }
2570
2571                                 if (object &&
2572                                     object->deleted &&
2573                                     object->soft_del && tags.chunk_id != 0) {
2574                                         /* Data chunk in a soft deleted file, throw it away
2575                                          * It's a soft deleted data chunk,
2576                                          * No need to copy this, just forget about it and
2577                                          * fix up the object.
2578                                          */
2579
2580                                         /* Free chunks already includes softdeleted chunks.
2581                                          * How ever this chunk is going to soon be really deleted
2582                                          * which will increment free chunks.
2583                                          * We have to decrement free chunks so this works out properly.
2584                                          */
2585                                         dev->n_free_chunks--;
2586                                         bi->soft_del_pages--;
2587
2588                                         object->n_data_chunks--;
2589
2590                                         if (object->n_data_chunks <= 0) {
2591                                                 /* remeber to clean up the object */
2592                                                 dev->gc_cleanup_list[dev->
2593                                                                      n_clean_ups]
2594                                                     = tags.obj_id;
2595                                                 dev->n_clean_ups++;
2596                                         }
2597                                         mark_flash = 0;
2598                                 } else if (0) {
2599                                         /* Todo object && object->deleted && object->n_data_chunks == 0 */
2600                                         /* Deleted object header with no data chunks.
2601                                          * Can be discarded and the file deleted.
2602                                          */
2603                                         object->hdr_chunk = 0;
2604                                         yaffs_free_tnode(object->my_dev,
2605                                                          object->
2606                                                          variant.file_variant.
2607                                                          top);
2608                                         object->variant.file_variant.top = NULL;
2609                                         yaffs_generic_obj_del(object);
2610
2611                                 } else if (object) {
2612                                         /* It's either a data chunk in a live file or
2613                                          * an ObjectHeader, so we're interested in it.
2614                                          * NB Need to keep the ObjectHeaders of deleted files
2615                                          * until the whole file has been deleted off
2616                                          */
2617                                         tags.serial_number++;
2618
2619                                         dev->n_gc_copies++;
2620
2621                                         if (tags.chunk_id == 0) {
2622                                                 /* It is an object Id,
2623                                                  * We need to nuke the shrinkheader flags first
2624                                                  * Also need to clean up shadowing.
2625                                                  * We no longer want the shrink_header flag since its work is done
2626                                                  * and if it is left in place it will mess up scanning.
2627                                                  */
2628
2629                                                 struct yaffs_obj_hdr *oh;
2630                                                 oh = (struct yaffs_obj_hdr *)
2631                                                     buffer;
2632
2633                                                 oh->is_shrink = 0;
2634                                                 tags.extra_is_shrink = 0;
2635
2636                                                 oh->shadows_obj = 0;
2637                                                 oh->inband_shadowed_obj_id = 0;
2638                                                 tags.extra_shadows = 0;
2639
2640                                                 /* Update file size */
2641                                                 if (object->variant_type ==
2642                                                     YAFFS_OBJECT_TYPE_FILE) {
2643                                                         oh->file_size =
2644                                                             object->variant.
2645                                                             file_variant.
2646                                                             file_size;
2647                                                         tags.extra_length =
2648                                                             oh->file_size;
2649                                                 }
2650
2651                                                 yaffs_verify_oh(object, oh,
2652                                                                 &tags, 1);
2653                                                 new_chunk =
2654                                                     yaffs_write_new_chunk(dev,
2655                                                                           (u8 *)
2656                                                                           oh,
2657                                                                           &tags,
2658                                                                           1);
2659                                         } else {
2660                                                 new_chunk =
2661                                                     yaffs_write_new_chunk(dev,
2662                                                                           buffer,
2663                                                                           &tags,
2664                                                                           1);
2665                                         }
2666
2667                                         if (new_chunk < 0) {
2668                                                 ret_val = YAFFS_FAIL;
2669                                         } else {
2670
2671                                                 /* Ok, now fix up the Tnodes etc. */
2672
2673                                                 if (tags.chunk_id == 0) {
2674                                                         /* It's a header */
2675                                                         object->hdr_chunk =
2676                                                             new_chunk;
2677                                                         object->serial =
2678                                                             tags.serial_number;
2679                                                 } else {
2680                                                         /* It's a data chunk */
2681                                                         int ok;
2682                                                         ok = yaffs_put_chunk_in_file(object, tags.chunk_id, new_chunk, 0);
2683                                                 }
2684                                         }
2685                                 }
2686
2687                                 if (ret_val == YAFFS_OK)
2688                                         yaffs_chunk_del(dev, old_chunk,
2689                                                         mark_flash, __LINE__);
2690
2691                         }
2692                 }
2693
2694                 yaffs_release_temp_buffer(dev, buffer, __LINE__);
2695
2696         }
2697
2698         yaffs_verify_collected_blk(dev, bi, block);
2699
2700         if (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
2701                 /*
2702                  * The gc did not complete. Set block state back to FULL
2703                  * because checkpointing does not restore gc.
2704                  */
2705                 bi->block_state = YAFFS_BLOCK_STATE_FULL;
2706         } else {
2707                 /* The gc completed. */
2708                 /* Do any required cleanups */
2709                 for (i = 0; i < dev->n_clean_ups; i++) {
2710                         /* Time to delete the file too */
2711                         object =
2712                             yaffs_find_by_number(dev, dev->gc_cleanup_list[i]);
2713                         if (object) {
2714                                 yaffs_free_tnode(dev,
2715                                                  object->variant.
2716                                                  file_variant.top);
2717                                 object->variant.file_variant.top = NULL;
2718                                 T(YAFFS_TRACE_GC,
2719                                   (TSTR
2720                                    ("yaffs: About to finally delete object %d"
2721                                     TENDSTR), object->obj_id));
2722                                 yaffs_generic_obj_del(object);
2723                                 object->my_dev->n_deleted_files--;
2724                         }
2725
2726                 }
2727
2728                 chunks_after = yaffs_get_erased_chunks(dev);
2729                 if (chunks_before >= chunks_after) {
2730                         T(YAFFS_TRACE_GC,
2731                           (TSTR
2732                            ("gc did not increase free chunks before %d after %d"
2733                             TENDSTR), chunks_before, chunks_after));
2734                 }
2735                 dev->gc_block = 0;
2736                 dev->gc_chunk = 0;
2737                 dev->n_clean_ups = 0;
2738         }
2739
2740         dev->gc_disable = 0;
2741
2742         return ret_val;
2743 }
2744
2745 /*
2746  * FindBlockForgarbageCollection is used to select the dirtiest block (or close enough)
2747  * for garbage collection.
2748  */
2749
2750 static unsigned yaffs_find_gc_block(struct yaffs_dev *dev,
2751                                     int aggressive, int background)
2752 {
2753         int i;
2754         int iterations;
2755         unsigned selected = 0;
2756         int prioritised = 0;
2757         int prioritised_exist = 0;
2758         struct yaffs_block_info *bi;
2759         int threshold;
2760
2761         /* First let's see if we need to grab a prioritised block */
2762         if (dev->has_pending_prioritised_gc && !aggressive) {
2763                 dev->gc_dirtiest = 0;
2764                 bi = dev->block_info;
2765                 for (i = dev->internal_start_block;
2766                      i <= dev->internal_end_block && !selected; i++) {
2767
2768                         if (bi->gc_prioritise) {
2769                                 prioritised_exist = 1;
2770                                 if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
2771                                     yaffs_block_ok_for_gc(dev, bi)) {
2772                                         selected = i;
2773                                         prioritised = 1;
2774                                 }
2775                         }
2776                         bi++;
2777                 }
2778
2779                 /*
2780                  * If there is a prioritised block and none was selected then
2781                  * this happened because there is at least one old dirty block gumming
2782                  * up the works. Let's gc the oldest dirty block.
2783                  */
2784
2785                 if (prioritised_exist &&
2786                     !selected && dev->oldest_dirty_block > 0)
2787                         selected = dev->oldest_dirty_block;
2788
2789                 if (!prioritised_exist) /* None found, so we can clear this */
2790                         dev->has_pending_prioritised_gc = 0;
2791         }
2792
2793         /* If we're doing aggressive GC then we are happy to take a less-dirty block, and
2794          * search harder.
2795          * else (we're doing a leasurely gc), then we only bother to do this if the
2796          * block has only a few pages in use.
2797          */
2798
2799         if (!selected) {
2800                 int pages_used;
2801                 int n_blocks =
2802                     dev->internal_end_block - dev->internal_start_block + 1;
2803                 if (aggressive) {
2804                         threshold = dev->param.chunks_per_block;
2805                         iterations = n_blocks;
2806                 } else {
2807                         int max_threshold;
2808
2809                         if (background)
2810                                 max_threshold = dev->param.chunks_per_block / 2;
2811                         else
2812                                 max_threshold = dev->param.chunks_per_block / 8;
2813
2814                         if (max_threshold < YAFFS_GC_PASSIVE_THRESHOLD)
2815                                 max_threshold = YAFFS_GC_PASSIVE_THRESHOLD;
2816
2817                         threshold = background ? (dev->gc_not_done + 2) * 2 : 0;
2818                         if (threshold < YAFFS_GC_PASSIVE_THRESHOLD)
2819                                 threshold = YAFFS_GC_PASSIVE_THRESHOLD;
2820                         if (threshold > max_threshold)
2821                                 threshold = max_threshold;
2822
2823                         iterations = n_blocks / 16 + 1;
2824                         if (iterations > 100)
2825                                 iterations = 100;
2826                 }
2827
2828                 for (i = 0;
2829                      i < iterations &&
2830                      (dev->gc_dirtiest < 1 ||
2831                       dev->gc_pages_in_use > YAFFS_GC_GOOD_ENOUGH); i++) {
2832                         dev->gc_block_finder++;
2833                         if (dev->gc_block_finder < dev->internal_start_block ||
2834                             dev->gc_block_finder > dev->internal_end_block)
2835                                 dev->gc_block_finder =
2836                                     dev->internal_start_block;
2837
2838                         bi = yaffs_get_block_info(dev, dev->gc_block_finder);
2839
2840                         pages_used = bi->pages_in_use - bi->soft_del_pages;
2841
2842                         if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
2843                             pages_used < dev->param.chunks_per_block &&
2844                             (dev->gc_dirtiest < 1
2845                              || pages_used < dev->gc_pages_in_use)
2846                             && yaffs_block_ok_for_gc(dev, bi)) {
2847                                 dev->gc_dirtiest = dev->gc_block_finder;
2848                                 dev->gc_pages_in_use = pages_used;
2849                         }
2850                 }
2851
2852                 if (dev->gc_dirtiest > 0 && dev->gc_pages_in_use <= threshold)
2853                         selected = dev->gc_dirtiest;
2854         }
2855
2856         /*
2857          * If nothing has been selected for a while, try selecting the oldest dirty
2858          * because that's gumming up the works.
2859          */
2860
2861         if (!selected && dev->param.is_yaffs2 &&
2862             dev->gc_not_done >= (background ? 10 : 20)) {
2863                 yaffs2_find_oldest_dirty_seq(dev);
2864                 if (dev->oldest_dirty_block > 0) {
2865                         selected = dev->oldest_dirty_block;
2866                         dev->gc_dirtiest = selected;
2867                         dev->oldest_dirty_gc_count++;
2868                         bi = yaffs_get_block_info(dev, selected);
2869                         dev->gc_pages_in_use =
2870                             bi->pages_in_use - bi->soft_del_pages;
2871                 } else {
2872                         dev->gc_not_done = 0;
2873                 }
2874         }
2875
2876         if (selected) {
2877                 T(YAFFS_TRACE_GC,
2878                   (TSTR
2879                    ("GC Selected block %d with %d free, prioritised:%d"
2880                     TENDSTR), selected,
2881                    dev->param.chunks_per_block - dev->gc_pages_in_use,
2882                    prioritised));
2883
2884                 dev->n_gc_blocks++;
2885                 if (background)
2886                         dev->bg_gcs++;
2887
2888                 dev->gc_dirtiest = 0;
2889                 dev->gc_pages_in_use = 0;
2890                 dev->gc_not_done = 0;
2891                 if (dev->refresh_skip > 0)
2892                         dev->refresh_skip--;
2893         } else {
2894                 dev->gc_not_done++;
2895                 T(YAFFS_TRACE_GC,
2896                   (TSTR
2897                    ("GC none: finder %d skip %d threshold %d dirtiest %d using %d oldest %d%s"
2898                     TENDSTR), dev->gc_block_finder, dev->gc_not_done, threshold,
2899                    dev->gc_dirtiest, dev->gc_pages_in_use,
2900                    dev->oldest_dirty_block, background ? " bg" : ""));
2901         }
2902
2903         return selected;
2904 }
2905
2906 /* New garbage collector
2907  * If we're very low on erased blocks then we do aggressive garbage collection
2908  * otherwise we do "leasurely" garbage collection.
2909  * Aggressive gc looks further (whole array) and will accept less dirty blocks.
2910  * Passive gc only inspects smaller areas and will only accept more dirty blocks.
2911  *
2912  * The idea is to help clear out space in a more spread-out manner.
2913  * Dunno if it really does anything useful.
2914  */
2915 static int yaffs_check_gc(struct yaffs_dev *dev, int background)
2916 {
2917         int aggressive = 0;
2918         int gc_ok = YAFFS_OK;
2919         int max_tries = 0;
2920         int min_erased;
2921         int erased_chunks;
2922         int checkpt_block_adjust;
2923
2924         if (dev->param.gc_control && (dev->param.gc_control(dev) & 1) == 0)
2925                 return YAFFS_OK;
2926
2927         if (dev->gc_disable) {
2928                 /* Bail out so we don't get recursive gc */
2929                 return YAFFS_OK;
2930         }
2931
2932         /* This loop should pass the first time.
2933          * We'll only see looping here if the collection does not increase space.
2934          */
2935
2936         do {
2937                 max_tries++;
2938
2939                 checkpt_block_adjust = yaffs_calc_checkpt_blocks_required(dev);
2940
2941                 min_erased =
2942                     dev->param.n_reserved_blocks + checkpt_block_adjust + 1;
2943                 erased_chunks =
2944                     dev->n_erased_blocks * dev->param.chunks_per_block;
2945
2946                 /* If we need a block soon then do aggressive gc. */
2947                 if (dev->n_erased_blocks < min_erased)
2948                         aggressive = 1;
2949                 else {
2950                         if (!background
2951                             && erased_chunks > (dev->n_free_chunks / 4))
2952                                 break;
2953
2954                         if (dev->gc_skip > 20)
2955                                 dev->gc_skip = 20;
2956                         if (erased_chunks < dev->n_free_chunks / 2 ||
2957                             dev->gc_skip < 1 || background)
2958                                 aggressive = 0;
2959                         else {
2960                                 dev->gc_skip--;
2961                                 break;
2962                         }
2963                 }
2964
2965                 dev->gc_skip = 5;
2966
2967                 /* If we don't already have a block being gc'd then see if we should start another */
2968
2969                 if (dev->gc_block < 1 && !aggressive) {
2970                         dev->gc_block = yaffs2_find_refresh_block(dev);
2971                         dev->gc_chunk = 0;
2972                         dev->n_clean_ups = 0;
2973                 }
2974                 if (dev->gc_block < 1) {
2975                         dev->gc_block =
2976                             yaffs_find_gc_block(dev, aggressive, background);
2977                         dev->gc_chunk = 0;
2978                         dev->n_clean_ups = 0;
2979                 }
2980
2981                 if (dev->gc_block > 0) {
2982                         dev->all_gcs++;
2983                         if (!aggressive)
2984                                 dev->passive_gc_count++;
2985
2986                         T(YAFFS_TRACE_GC,
2987                           (TSTR
2988                            ("yaffs: GC n_erased_blocks %d aggressive %d"
2989                             TENDSTR), dev->n_erased_blocks, aggressive));
2990
2991                         gc_ok = yaffs_gc_block(dev, dev->gc_block, aggressive);
2992                 }
2993
2994                 if (dev->n_erased_blocks < (dev->param.n_reserved_blocks)
2995                     && dev->gc_block > 0) {
2996                         T(YAFFS_TRACE_GC,
2997                           (TSTR
2998                            ("yaffs: GC !!!no reclaim!!! n_erased_blocks %d after try %d block %d"
2999                             TENDSTR), dev->n_erased_blocks, max_tries,
3000                            dev->gc_block));
3001                 }
3002         } while ((dev->n_erased_blocks < dev->param.n_reserved_blocks) &&
3003                  (dev->gc_block > 0) && (max_tries < 2));
3004
3005         return aggressive ? gc_ok : YAFFS_OK;
3006 }
3007
3008 /*
3009  * yaffs_bg_gc()
3010  * Garbage collects. Intended to be called from a background thread.
3011  * Returns non-zero if at least half the free chunks are erased.
3012  */
3013 int yaffs_bg_gc(struct yaffs_dev *dev, unsigned urgency)
3014 {
3015         int erased_chunks = dev->n_erased_blocks * dev->param.chunks_per_block;
3016
3017         T(YAFFS_TRACE_BACKGROUND, (TSTR("Background gc %u" TENDSTR), urgency));
3018
3019         yaffs_check_gc(dev, 1);
3020         return erased_chunks > dev->n_free_chunks / 2;
3021 }
3022
3023 /*-------------------- Data file manipulation -----------------*/
3024
3025 static int yaffs_rd_data_obj(struct yaffs_obj *in, int inode_chunk, u8 * buffer)
3026 {
3027         int nand_chunk = yaffs_find_chunk_in_file(in, inode_chunk, NULL);
3028
3029         if (nand_chunk >= 0)
3030                 return yaffs_rd_chunk_tags_nand(in->my_dev, nand_chunk,
3031                                                 buffer, NULL);
3032         else {
3033                 T(YAFFS_TRACE_NANDACCESS,
3034                   (TSTR("Chunk %d not found zero instead" TENDSTR),
3035                    nand_chunk));
3036                 /* get sane (zero) data if you read a hole */
3037                 memset(buffer, 0, in->my_dev->data_bytes_per_chunk);
3038                 return 0;
3039         }
3040
3041 }
3042
3043 void yaffs_chunk_del(struct yaffs_dev *dev, int chunk_id, int mark_flash,
3044                      int lyn)
3045 {
3046         int block;
3047         int page;
3048         struct yaffs_ext_tags tags;
3049         struct yaffs_block_info *bi;
3050
3051         if (chunk_id <= 0)
3052                 return;
3053
3054         dev->n_deletions++;
3055         block = chunk_id / dev->param.chunks_per_block;
3056         page = chunk_id % dev->param.chunks_per_block;
3057
3058         if (!yaffs_check_chunk_bit(dev, block, page))
3059                 T(YAFFS_TRACE_VERIFY,
3060                   (TSTR("Deleting invalid chunk %d" TENDSTR), chunk_id));
3061
3062         bi = yaffs_get_block_info(dev, block);
3063
3064         yaffs2_update_oldest_dirty_seq(dev, block, bi);
3065
3066         T(YAFFS_TRACE_DELETION,
3067           (TSTR("line %d delete of chunk %d" TENDSTR), lyn, chunk_id));
3068
3069         if (!dev->param.is_yaffs2 && mark_flash &&
3070             bi->block_state != YAFFS_BLOCK_STATE_COLLECTING) {
3071
3072                 yaffs_init_tags(&tags);
3073
3074                 tags.is_deleted = 1;
3075
3076                 yaffs_wr_chunk_tags_nand(dev, chunk_id, NULL, &tags);
3077                 yaffs_handle_chunk_update(dev, chunk_id, &tags);
3078         } else {
3079                 dev->n_unmarked_deletions++;
3080         }
3081
3082         /* Pull out of the management area.
3083          * If the whole block became dirty, this will kick off an erasure.
3084          */
3085         if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING ||
3086             bi->block_state == YAFFS_BLOCK_STATE_FULL ||
3087             bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCANNING ||
3088             bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
3089                 dev->n_free_chunks++;
3090
3091                 yaffs_clear_chunk_bit(dev, block, page);
3092
3093                 bi->pages_in_use--;
3094
3095                 if (bi->pages_in_use == 0 &&
3096                     !bi->has_shrink_hdr &&
3097                     bi->block_state != YAFFS_BLOCK_STATE_ALLOCATING &&
3098                     bi->block_state != YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
3099                         yaffs_block_became_dirty(dev, block);
3100                 }
3101
3102         }
3103
3104 }
3105
3106 static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
3107                              const u8 * buffer, int n_bytes, int use_reserve)
3108 {
3109         /* Find old chunk Need to do this to get serial number
3110          * Write new one and patch into tree.
3111          * Invalidate old tags.
3112          */
3113
3114         int prev_chunk_id;
3115         struct yaffs_ext_tags prev_tags;
3116
3117         int new_chunk_id;
3118         struct yaffs_ext_tags new_tags;
3119
3120         struct yaffs_dev *dev = in->my_dev;
3121
3122         yaffs_check_gc(dev, 0);
3123
3124         /* Get the previous chunk at this location in the file if it exists.
3125          * If it does not exist then put a zero into the tree. This creates
3126          * the tnode now, rather than later when it is harder to clean up.
3127          */
3128         prev_chunk_id = yaffs_find_chunk_in_file(in, inode_chunk, &prev_tags);
3129         if (prev_chunk_id < 1 &&
3130             !yaffs_put_chunk_in_file(in, inode_chunk, 0, 0))
3131                 return 0;
3132
3133         /* Set up new tags */
3134         yaffs_init_tags(&new_tags);
3135
3136         new_tags.chunk_id = inode_chunk;
3137         new_tags.obj_id = in->obj_id;
3138         new_tags.serial_number =
3139             (prev_chunk_id > 0) ? prev_tags.serial_number + 1 : 1;
3140         new_tags.n_bytes = n_bytes;
3141
3142         if (n_bytes < 1 || n_bytes > dev->param.total_bytes_per_chunk) {
3143                 T(YAFFS_TRACE_ERROR,
3144                   (TSTR("Writing %d bytes to chunk!!!!!!!!!" TENDSTR),
3145                    n_bytes));
3146                 YBUG();
3147         }
3148
3149         new_chunk_id =
3150             yaffs_write_new_chunk(dev, buffer, &new_tags, use_reserve);
3151
3152         if (new_chunk_id > 0) {
3153                 yaffs_put_chunk_in_file(in, inode_chunk, new_chunk_id, 0);
3154
3155                 if (prev_chunk_id > 0)
3156                         yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
3157
3158                 yaffs_verify_file_sane(in);
3159         }
3160         return new_chunk_id;
3161
3162 }
3163
3164
3165
3166 static int yaffs_do_xattrib_mod(struct yaffs_obj *obj, int set,
3167                                 const YCHAR * name, const void *value, int size,
3168                                 int flags)
3169 {
3170         struct yaffs_xattr_mod xmod;
3171
3172         int result;
3173
3174         xmod.set = set;
3175         xmod.name = name;
3176         xmod.data = value;
3177         xmod.size = size;
3178         xmod.flags = flags;
3179         xmod.result = -ENOSPC;
3180
3181         result = yaffs_update_oh(obj, NULL, 0, 0, 0, &xmod);
3182
3183         if (result > 0)
3184                 return xmod.result;
3185         else
3186                 return -ENOSPC;
3187 }
3188
3189 static int yaffs_apply_xattrib_mod(struct yaffs_obj *obj, char *buffer,
3190                                    struct yaffs_xattr_mod *xmod)
3191 {
3192         int retval = 0;
3193         int x_offs = sizeof(struct yaffs_obj_hdr);
3194         struct yaffs_dev *dev = obj->my_dev;
3195         int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
3196
3197         char *x_buffer = buffer + x_offs;
3198
3199         if (xmod->set)
3200                 retval =
3201                     nval_set(x_buffer, x_size, xmod->name, xmod->data,
3202                              xmod->size, xmod->flags);
3203         else
3204                 retval = nval_del(x_buffer, x_size, xmod->name);
3205
3206         obj->has_xattr = nval_hasvalues(x_buffer, x_size);
3207         obj->xattr_known = 1;
3208
3209         xmod->result = retval;
3210
3211         return retval;
3212 }
3213
3214 static int yaffs_do_xattrib_fetch(struct yaffs_obj *obj, const YCHAR * name,
3215                                   void *value, int size)
3216 {
3217         char *buffer = NULL;
3218         int result;
3219         struct yaffs_ext_tags tags;
3220         struct yaffs_dev *dev = obj->my_dev;
3221         int x_offs = sizeof(struct yaffs_obj_hdr);
3222         int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
3223
3224         char *x_buffer;
3225
3226         int retval = 0;
3227
3228         if (obj->hdr_chunk < 1)
3229                 return -ENODATA;
3230
3231         /* If we know that the object has no xattribs then don't do all the
3232          * reading and parsing.
3233          */
3234         if (obj->xattr_known && !obj->has_xattr) {
3235                 if (name)
3236                         return -ENODATA;
3237                 else
3238                         return 0;
3239         }
3240
3241         buffer = (char *)yaffs_get_temp_buffer(dev, __LINE__);
3242         if (!buffer)
3243                 return -ENOMEM;
3244
3245         result =
3246             yaffs_rd_chunk_tags_nand(dev, obj->hdr_chunk, (u8 *) buffer, &tags);
3247
3248         if (result != YAFFS_OK)
3249                 retval = -ENOENT;
3250         else {
3251                 x_buffer = buffer + x_offs;
3252
3253                 if (!obj->xattr_known) {
3254                         obj->has_xattr = nval_hasvalues(x_buffer, x_size);
3255                         obj->xattr_known = 1;
3256                 }
3257
3258                 if (name)
3259                         retval = nval_get(x_buffer, x_size, name, value, size);
3260                 else
3261                         retval = nval_list(x_buffer, x_size, value, size);
3262         }
3263         yaffs_release_temp_buffer(dev, (u8 *) buffer, __LINE__);
3264         return retval;
3265 }
3266
3267 int yaffs_set_xattrib(struct yaffs_obj *obj, const YCHAR * name,
3268                       const void *value, int size, int flags)
3269 {
3270         return yaffs_do_xattrib_mod(obj, 1, name, value, size, flags);
3271 }
3272
3273 int yaffs_remove_xattrib(struct yaffs_obj *obj, const YCHAR * name)
3274 {
3275         return yaffs_do_xattrib_mod(obj, 0, name, NULL, 0, 0);
3276 }
3277
3278 int yaffs_get_xattrib(struct yaffs_obj *obj, const YCHAR * name, void *value,
3279                       int size)
3280 {
3281         return yaffs_do_xattrib_fetch(obj, name, value, size);
3282 }
3283
3284 int yaffs_list_xattrib(struct yaffs_obj *obj, char *buffer, int size)
3285 {
3286         return yaffs_do_xattrib_fetch(obj, NULL, buffer, size);
3287 }
3288
3289 static void yaffs_check_obj_details_loaded(struct yaffs_obj *in)
3290 {
3291         u8 *chunk_data;
3292         struct yaffs_obj_hdr *oh;
3293         struct yaffs_dev *dev;
3294         struct yaffs_ext_tags tags;
3295         int result;
3296         int alloc_failed = 0;
3297
3298         if (!in)
3299                 return;
3300
3301         dev = in->my_dev;
3302
3303         if (in->lazy_loaded && in->hdr_chunk > 0) {
3304                 in->lazy_loaded = 0;
3305                 chunk_data = yaffs_get_temp_buffer(dev, __LINE__);
3306
3307                 result =
3308                     yaffs_rd_chunk_tags_nand(dev, in->hdr_chunk, chunk_data,
3309                                              &tags);
3310                 oh = (struct yaffs_obj_hdr *)chunk_data;
3311
3312                 in->yst_mode = oh->yst_mode;
3313                 yaffs_load_attribs(in, oh);
3314                 yaffs_set_obj_name_from_oh(in, oh);
3315
3316                 if (in->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
3317                         in->variant.symlink_variant.alias =
3318                             yaffs_clone_str(oh->alias);
3319                         if (!in->variant.symlink_variant.alias)
3320                                 alloc_failed = 1;       /* Not returned to caller */
3321                 }
3322
3323                 yaffs_release_temp_buffer(dev, chunk_data, __LINE__);
3324         }
3325 }
3326
3327 static void yaffs_load_name_from_oh(struct yaffs_dev *dev, YCHAR * name,
3328                                     const YCHAR * oh_name, int buff_size)
3329 {
3330 #ifdef CONFIG_YAFFS_AUTO_UNICODE
3331         if (dev->param.auto_unicode) {
3332                 if (*oh_name) {
3333                         /* It is an ASCII name, so do an ASCII to unicode conversion */
3334                         const char *ascii_oh_name = (const char *)oh_name;
3335                         int n = buff_size - 1;
3336                         while (n > 0 && *ascii_oh_name) {
3337                                 *name = *ascii_oh_name;
3338                                 name++;
3339                                 ascii_oh_name++;
3340                                 n--;
3341                         }
3342                 } else {
3343                         strncpy(name, oh_name + 1, buff_size - 1);
3344                 }
3345         } else {
3346 #else
3347         {
3348 #endif
3349                 strncpy(name, oh_name, buff_size - 1);
3350         }
3351 }
3352
3353 static void yaffs_load_oh_from_name(struct yaffs_dev *dev, YCHAR * oh_name,
3354                                     const YCHAR * name)
3355 {
3356 #ifdef CONFIG_YAFFS_AUTO_UNICODE
3357
3358         int is_ascii;
3359         YCHAR *w;
3360
3361         if (dev->param.auto_unicode) {
3362
3363                 is_ascii = 1;
3364                 w = name;
3365
3366                 /* Figure out if the name will fit in ascii character set */
3367                 while (is_ascii && *w) {
3368                         if ((*w) & 0xff00)
3369                                 is_ascii = 0;
3370                         w++;
3371                 }
3372
3373                 if (is_ascii) {
3374                         /* It is an ASCII name, so do a unicode to ascii conversion */
3375                         char *ascii_oh_name = (char *)oh_name;
3376                         int n = YAFFS_MAX_NAME_LENGTH - 1;
3377                         while (n > 0 && *name) {
3378                                 *ascii_oh_name = *name;
3379                                 name++;
3380                                 ascii_oh_name++;
3381                                 n--;
3382                         }
3383                 } else {
3384                         /* It is a unicode name, so save starting at the second YCHAR */
3385                         *oh_name = 0;
3386                         strncpy(oh_name + 1, name,
3387                                       YAFFS_MAX_NAME_LENGTH - 2);
3388                 }
3389         } else {
3390 #else
3391         {
3392 #endif
3393                 strncpy(oh_name, name, YAFFS_MAX_NAME_LENGTH - 1);
3394         }
3395
3396 }
3397
3398 /* UpdateObjectHeader updates the header on NAND for an object.
3399  * If name is not NULL, then that new name is used.
3400  */
3401 int yaffs_update_oh(struct yaffs_obj *in, const YCHAR * name, int force,
3402                     int is_shrink, int shadows, struct yaffs_xattr_mod *xmod)
3403 {
3404
3405         struct yaffs_block_info *bi;
3406
3407         struct yaffs_dev *dev = in->my_dev;
3408
3409         int prev_chunk_id;
3410         int ret_val = 0;
3411         int result = 0;
3412
3413         int new_chunk_id;
3414         struct yaffs_ext_tags new_tags;
3415         struct yaffs_ext_tags old_tags;
3416         const YCHAR *alias = NULL;
3417
3418         u8 *buffer = NULL;
3419         YCHAR old_name[YAFFS_MAX_NAME_LENGTH + 1];
3420
3421         struct yaffs_obj_hdr *oh = NULL;
3422
3423         strcpy(old_name, _Y("silly old name"));
3424
3425         if (!in->fake || in == dev->root_dir || /* The root_dir should also be saved */
3426             force || xmod) {
3427
3428                 yaffs_check_gc(dev, 0);
3429                 yaffs_check_obj_details_loaded(in);
3430
3431                 buffer = yaffs_get_temp_buffer(in->my_dev, __LINE__);
3432                 oh = (struct yaffs_obj_hdr *)buffer;
3433
3434                 prev_chunk_id = in->hdr_chunk;
3435
3436                 if (prev_chunk_id > 0) {
3437                         result = yaffs_rd_chunk_tags_nand(dev, prev_chunk_id,
3438                                                           buffer, &old_tags);
3439
3440                         yaffs_verify_oh(in, oh, &old_tags, 0);
3441
3442                         memcpy(old_name, oh->name, sizeof(oh->name));
3443                         memset(buffer, 0xFF, sizeof(struct yaffs_obj_hdr));
3444                 } else {
3445                         memset(buffer, 0xFF, dev->data_bytes_per_chunk);
3446                 }
3447
3448                 oh->type = in->variant_type;
3449                 oh->yst_mode = in->yst_mode;
3450                 oh->shadows_obj = oh->inband_shadowed_obj_id = shadows;
3451
3452                 yaffs_load_attribs_oh(oh, in);
3453
3454                 if (in->parent)
3455                         oh->parent_obj_id = in->parent->obj_id;
3456                 else
3457                         oh->parent_obj_id = 0;
3458
3459                 if (name && *name) {
3460                         memset(oh->name, 0, sizeof(oh->name));
3461                         yaffs_load_oh_from_name(dev, oh->name, name);
3462                 } else if (prev_chunk_id > 0) {
3463                         memcpy(oh->name, old_name, sizeof(oh->name));
3464                 } else {
3465                         memset(oh->name, 0, sizeof(oh->name));
3466                 }
3467
3468                 oh->is_shrink = is_shrink;
3469
3470                 switch (in->variant_type) {
3471                 case YAFFS_OBJECT_TYPE_UNKNOWN:
3472                         /* Should not happen */
3473                         break;
3474                 case YAFFS_OBJECT_TYPE_FILE:
3475                         oh->file_size =
3476                             (oh->parent_obj_id == YAFFS_OBJECTID_DELETED
3477                              || oh->parent_obj_id ==
3478                              YAFFS_OBJECTID_UNLINKED) ? 0 : in->
3479                             variant.file_variant.file_size;
3480                         break;
3481                 case YAFFS_OBJECT_TYPE_HARDLINK:
3482                         oh->equiv_id = in->variant.hardlink_variant.equiv_id;
3483                         break;
3484                 case YAFFS_OBJECT_TYPE_SPECIAL:
3485                         /* Do nothing */
3486                         break;
3487                 case YAFFS_OBJECT_TYPE_DIRECTORY:
3488                         /* Do nothing */
3489                         break;
3490                 case YAFFS_OBJECT_TYPE_SYMLINK:
3491                         alias = in->variant.symlink_variant.alias;
3492                         if (!alias)
3493                                 alias = _Y("no alias");
3494                         strncpy(oh->alias, alias, YAFFS_MAX_ALIAS_LENGTH);
3495                         oh->alias[YAFFS_MAX_ALIAS_LENGTH] = 0;
3496                         break;
3497                 }
3498
3499                 /* process any xattrib modifications */
3500                 if (xmod)
3501                         yaffs_apply_xattrib_mod(in, (char *)buffer, xmod);
3502
3503                 /* Tags */
3504                 yaffs_init_tags(&new_tags);
3505                 in->serial++;
3506                 new_tags.chunk_id = 0;
3507                 new_tags.obj_id = in->obj_id;
3508                 new_tags.serial_number = in->serial;
3509
3510                 /* Add extra info for file header */
3511
3512                 new_tags.extra_available = 1;
3513                 new_tags.extra_parent_id = oh->parent_obj_id;
3514                 new_tags.extra_length = oh->file_size;
3515                 new_tags.extra_is_shrink = oh->is_shrink;
3516                 new_tags.extra_equiv_id = oh->equiv_id;
3517                 new_tags.extra_shadows = (oh->shadows_obj > 0) ? 1 : 0;
3518                 new_tags.extra_obj_type = in->variant_type;
3519
3520                 yaffs_verify_oh(in, oh, &new_tags, 1);
3521
3522                 /* Create new chunk in NAND */
3523                 new_chunk_id =
3524                     yaffs_write_new_chunk(dev, buffer, &new_tags,
3525                                           (prev_chunk_id > 0) ? 1 : 0);
3526
3527                 if (new_chunk_id >= 0) {
3528
3529                         in->hdr_chunk = new_chunk_id;
3530
3531                         if (prev_chunk_id > 0) {
3532                                 yaffs_chunk_del(dev, prev_chunk_id, 1,
3533                                                 __LINE__);
3534                         }
3535
3536                         if (!yaffs_obj_cache_dirty(in))
3537                                 in->dirty = 0;
3538
3539                         /* If this was a shrink, then mark the block that the chunk lives on */
3540                         if (is_shrink) {
3541                                 bi = yaffs_get_block_info(in->my_dev,
3542                                                           new_chunk_id /
3543                                                           in->my_dev->param.
3544                                                           chunks_per_block);
3545                                 bi->has_shrink_hdr = 1;
3546                         }
3547
3548                 }
3549
3550                 ret_val = new_chunk_id;
3551
3552         }
3553
3554         if (buffer)
3555                 yaffs_release_temp_buffer(dev, buffer, __LINE__);
3556
3557         return ret_val;
3558 }
3559
3560 /*--------------------- File read/write ------------------------
3561  * Read and write have very similar structures.
3562  * In general the read/write has three parts to it
3563  * An incomplete chunk to start with (if the read/write is not chunk-aligned)
3564  * Some complete chunks
3565  * An incomplete chunk to end off with
3566  *
3567  * Curve-balls: the first chunk might also be the last chunk.
3568  */
3569
3570 int yaffs_file_rd(struct yaffs_obj *in, u8 * buffer, loff_t offset, int n_bytes)
3571 {
3572
3573         int chunk;
3574         u32 start;
3575         int n_copy;
3576         int n = n_bytes;
3577         int n_done = 0;
3578         struct yaffs_cache *cache;
3579
3580         struct yaffs_dev *dev;
3581
3582         dev = in->my_dev;
3583
3584         while (n > 0) {
3585                 /* chunk = offset / dev->data_bytes_per_chunk + 1; */
3586                 /* start = offset % dev->data_bytes_per_chunk; */
3587                 yaffs_addr_to_chunk(dev, offset, &chunk, &start);
3588                 chunk++;
3589
3590                 /* OK now check for the curveball where the start and end are in
3591                  * the same chunk.
3592                  */
3593                 if ((start + n) < dev->data_bytes_per_chunk)
3594                         n_copy = n;
3595                 else
3596                         n_copy = dev->data_bytes_per_chunk - start;
3597
3598                 cache = yaffs_find_chunk_cache(in, chunk);
3599
3600                 /* If the chunk is already in the cache or it is less than a whole chunk
3601                  * or we're using inband tags then use the cache (if there is caching)
3602                  * else bypass the cache.
3603                  */
3604                 if (cache || n_copy != dev->data_bytes_per_chunk
3605                     || dev->param.inband_tags) {
3606                         if (dev->param.n_caches > 0) {
3607
3608                                 /* If we can't find the data in the cache, then load it up. */
3609
3610                                 if (!cache) {
3611                                         cache =
3612                                             yaffs_grab_chunk_cache(in->my_dev);
3613                                         cache->object = in;
3614                                         cache->chunk_id = chunk;
3615                                         cache->dirty = 0;
3616                                         cache->locked = 0;
3617                                         yaffs_rd_data_obj(in, chunk,
3618                                                           cache->data);
3619                                         cache->n_bytes = 0;
3620                                 }
3621
3622                                 yaffs_use_cache(dev, cache, 0);
3623
3624                                 cache->locked = 1;
3625
3626                                 memcpy(buffer, &cache->data[start], n_copy);
3627
3628                                 cache->locked = 0;
3629                         } else {
3630                                 /* Read into the local buffer then copy.. */
3631
3632                                 u8 *local_buffer =
3633                                     yaffs_get_temp_buffer(dev, __LINE__);
3634                                 yaffs_rd_data_obj(in, chunk, local_buffer);
3635
3636                                 memcpy(buffer, &local_buffer[start], n_copy);
3637
3638                                 yaffs_release_temp_buffer(dev, local_buffer,
3639                                                           __LINE__);
3640                         }
3641
3642                 } else {
3643
3644                         /* A full chunk. Read directly into the supplied buffer. */
3645                         yaffs_rd_data_obj(in, chunk, buffer);
3646
3647                 }
3648
3649                 n -= n_copy;
3650                 offset += n_copy;
3651                 buffer += n_copy;
3652                 n_done += n_copy;
3653
3654         }
3655
3656         return n_done;
3657 }
3658
3659 int yaffs_do_file_wr(struct yaffs_obj *in, const u8 * buffer, loff_t offset,
3660                      int n_bytes, int write_trhrough)
3661 {
3662
3663         int chunk;
3664         u32 start;
3665         int n_copy;
3666         int n = n_bytes;
3667         int n_done = 0;
3668         int n_writeback;
3669         int start_write = offset;
3670         int chunk_written = 0;
3671         u32 n_bytes_read;
3672         u32 chunk_start;
3673
3674         struct yaffs_dev *dev;
3675
3676         dev = in->my_dev;
3677
3678         while (n > 0 && chunk_written >= 0) {
3679                 yaffs_addr_to_chunk(dev, offset, &chunk, &start);
3680
3681                 if (chunk * dev->data_bytes_per_chunk + start != offset ||
3682                     start >= dev->data_bytes_per_chunk) {
3683                         T(YAFFS_TRACE_ERROR,
3684                           (TSTR
3685                            ("AddrToChunk of offset %d gives chunk %d start %d"
3686                             TENDSTR), (int)offset, chunk, start));
3687                 }
3688                 chunk++;        /* File pos to chunk in file offset */
3689
3690                 /* OK now check for the curveball where the start and end are in
3691                  * the same chunk.
3692                  */
3693
3694                 if ((start + n) < dev->data_bytes_per_chunk) {
3695                         n_copy = n;
3696
3697                         /* Now folks, to calculate how many bytes to write back....
3698                          * If we're overwriting and not writing to then end of file then
3699                          * we need to write back as much as was there before.
3700                          */
3701
3702                         chunk_start = ((chunk - 1) * dev->data_bytes_per_chunk);
3703
3704                         if (chunk_start > in->variant.file_variant.file_size)
3705                                 n_bytes_read = 0;       /* Past end of file */
3706                         else
3707                                 n_bytes_read =
3708                                     in->variant.file_variant.file_size -
3709                                     chunk_start;
3710
3711                         if (n_bytes_read > dev->data_bytes_per_chunk)
3712                                 n_bytes_read = dev->data_bytes_per_chunk;
3713
3714                         n_writeback =
3715                             (n_bytes_read >
3716                              (start + n)) ? n_bytes_read : (start + n);
3717
3718                         if (n_writeback < 0
3719                             || n_writeback > dev->data_bytes_per_chunk)
3720                                 YBUG();
3721
3722                 } else {
3723                         n_copy = dev->data_bytes_per_chunk - start;
3724                         n_writeback = dev->data_bytes_per_chunk;
3725                 }
3726
3727                 if (n_copy != dev->data_bytes_per_chunk
3728                     || dev->param.inband_tags) {
3729                         /* An incomplete start or end chunk (or maybe both start and end chunk),
3730                          * or we're using inband tags, so we want to use the cache buffers.
3731                          */
3732                         if (dev->param.n_caches > 0) {
3733                                 struct yaffs_cache *cache;
3734                                 /* If we can't find the data in the cache, then load the cache */
3735                                 cache = yaffs_find_chunk_cache(in, chunk);
3736
3737                                 if (!cache
3738                                     && yaffs_check_alloc_available(dev, 1)) {
3739                                         cache = yaffs_grab_chunk_cache(dev);
3740                                         cache->object = in;
3741                                         cache->chunk_id = chunk;
3742                                         cache->dirty = 0;
3743                                         cache->locked = 0;
3744                                         yaffs_rd_data_obj(in, chunk,
3745                                                           cache->data);
3746                                 } else if (cache &&
3747                                            !cache->dirty &&
3748                                            !yaffs_check_alloc_available(dev,
3749                                                                         1)) {
3750                                         /* Drop the cache if it was a read cache item and
3751                                          * no space check has been made for it.
3752                                          */
3753                                         cache = NULL;
3754                                 }
3755
3756                                 if (cache) {
3757                                         yaffs_use_cache(dev, cache, 1);
3758                                         cache->locked = 1;
3759
3760                                         memcpy(&cache->data[start], buffer,
3761                                                n_copy);
3762
3763                                         cache->locked = 0;
3764                                         cache->n_bytes = n_writeback;
3765
3766                                         if (write_trhrough) {
3767                                                 chunk_written =
3768                                                     yaffs_wr_data_obj
3769                                                     (cache->object,
3770                                                      cache->chunk_id,
3771                                                      cache->data,
3772                                                      cache->n_bytes, 1);
3773                                                 cache->dirty = 0;
3774                                         }
3775
3776                                 } else {
3777                                         chunk_written = -1;     /* fail the write */
3778                                 }
3779                         } else {
3780                                 /* An incomplete start or end chunk (or maybe both start and end chunk)
3781                                  * Read into the local buffer then copy, then copy over and write back.
3782                                  */
3783
3784                                 u8 *local_buffer =
3785                                     yaffs_get_temp_buffer(dev, __LINE__);
3786
3787                                 yaffs_rd_data_obj(in, chunk, local_buffer);
3788
3789                                 memcpy(&local_buffer[start], buffer, n_copy);
3790
3791                                 chunk_written =
3792                                     yaffs_wr_data_obj(in, chunk,
3793                                                       local_buffer,
3794                                                       n_writeback, 0);
3795
3796                                 yaffs_release_temp_buffer(dev, local_buffer,
3797                                                           __LINE__);
3798
3799                         }
3800
3801                 } else {
3802                         /* A full chunk. Write directly from the supplied buffer. */
3803
3804                         chunk_written =
3805                             yaffs_wr_data_obj(in, chunk, buffer,
3806                                               dev->data_bytes_per_chunk, 0);
3807
3808                         /* Since we've overwritten the cached data, we better invalidate it. */
3809                         yaffs_invalidate_chunk_cache(in, chunk);
3810                 }
3811
3812                 if (chunk_written >= 0) {
3813                         n -= n_copy;
3814                         offset += n_copy;
3815                         buffer += n_copy;
3816                         n_done += n_copy;
3817                 }
3818
3819         }
3820
3821         /* Update file object */
3822
3823         if ((start_write + n_done) > in->variant.file_variant.file_size)
3824                 in->variant.file_variant.file_size = (start_write + n_done);
3825
3826         in->dirty = 1;
3827
3828         return n_done;
3829 }
3830
3831 int yaffs_wr_file(struct yaffs_obj *in, const u8 * buffer, loff_t offset,
3832                   int n_bytes, int write_trhrough)
3833 {
3834         yaffs2_handle_hole(in, offset);
3835         return yaffs_do_file_wr(in, buffer, offset, n_bytes, write_trhrough);
3836 }
3837
3838 /* ---------------------- File resizing stuff ------------------ */
3839
3840 static void yaffs_prune_chunks(struct yaffs_obj *in, int new_size)
3841 {
3842
3843         struct yaffs_dev *dev = in->my_dev;
3844         int old_size = in->variant.file_variant.file_size;
3845
3846         int last_del = 1 + (old_size - 1) / dev->data_bytes_per_chunk;
3847
3848         int start_del = 1 + (new_size + dev->data_bytes_per_chunk - 1) /
3849             dev->data_bytes_per_chunk;
3850         int i;
3851         int chunk_id;
3852
3853         /* Delete backwards so that we don't end up with holes if
3854          * power is lost part-way through the operation.
3855          */
3856         for (i = last_del; i >= start_del; i--) {
3857                 /* NB this could be optimised somewhat,
3858                  * eg. could retrieve the tags and write them without
3859                  * using yaffs_chunk_del
3860                  */
3861
3862                 chunk_id = yaffs_find_del_file_chunk(in, i, NULL);
3863                 if (chunk_id > 0) {
3864                         if (chunk_id <
3865                             (dev->internal_start_block *
3866                              dev->param.chunks_per_block)
3867                             || chunk_id >=
3868                             ((dev->internal_end_block +
3869                               1) * dev->param.chunks_per_block)) {
3870                                 T(YAFFS_TRACE_ALWAYS,
3871                                   (TSTR
3872                                    ("Found daft chunk_id %d for %d" TENDSTR),
3873                                    chunk_id, i));
3874                         } else {
3875                                 in->n_data_chunks--;
3876                                 yaffs_chunk_del(dev, chunk_id, 1, __LINE__);
3877                         }
3878                 }
3879         }
3880
3881 }
3882
3883 void yaffs_resize_file_down(struct yaffs_obj *obj, loff_t new_size)
3884 {
3885         int new_full;
3886         u32 new_partial;
3887         struct yaffs_dev *dev = obj->my_dev;
3888
3889         yaffs_addr_to_chunk(dev, new_size, &new_full, &new_partial);
3890
3891         yaffs_prune_chunks(obj, new_size);
3892
3893         if (new_partial != 0) {
3894                 int last_chunk = 1 + new_full;
3895                 u8 *local_buffer = yaffs_get_temp_buffer(dev, __LINE__);
3896
3897                 /* Got to read and rewrite the last chunk with its new size and zero pad */
3898                 yaffs_rd_data_obj(obj, last_chunk, local_buffer);
3899                 memset(local_buffer + new_partial, 0,
3900                        dev->data_bytes_per_chunk - new_partial);
3901
3902                 yaffs_wr_data_obj(obj, last_chunk, local_buffer,
3903                                   new_partial, 1);
3904
3905                 yaffs_release_temp_buffer(dev, local_buffer, __LINE__);
3906         }
3907
3908         obj->variant.file_variant.file_size = new_size;
3909
3910         yaffs_prune_tree(dev, &obj->variant.file_variant);
3911 }
3912
3913 int yaffs_resize_file(struct yaffs_obj *in, loff_t new_size)
3914 {
3915         struct yaffs_dev *dev = in->my_dev;
3916         int old_size = in->variant.file_variant.file_size;
3917
3918         yaffs_flush_file_cache(in);
3919         yaffs_invalidate_whole_cache(in);
3920
3921         yaffs_check_gc(dev, 0);
3922
3923         if (in->variant_type != YAFFS_OBJECT_TYPE_FILE)
3924                 return YAFFS_FAIL;
3925
3926         if (new_size == old_size)
3927                 return YAFFS_OK;
3928
3929         if (new_size > old_size) {
3930                 yaffs2_handle_hole(in, new_size);
3931                 in->variant.file_variant.file_size = new_size;
3932         } else {
3933                 /* new_size < old_size */
3934                 yaffs_resize_file_down(in, new_size);
3935         }
3936
3937         /* Write a new object header to reflect the resize.
3938          * show we've shrunk the file, if need be
3939          * Do this only if the file is not in the deleted directories
3940          * and is not shadowed.
3941          */
3942         if (in->parent &&
3943             !in->is_shadowed &&
3944             in->parent->obj_id != YAFFS_OBJECTID_UNLINKED &&
3945             in->parent->obj_id != YAFFS_OBJECTID_DELETED)
3946                 yaffs_update_oh(in, NULL, 0, 0, 0, NULL);
3947
3948         return YAFFS_OK;
3949 }
3950
3951 int yaffs_flush_file(struct yaffs_obj *in, int update_time, int data_sync)
3952 {
3953         int ret_val;
3954         if (in->dirty) {
3955                 yaffs_flush_file_cache(in);
3956                 if (data_sync)  /* Only sync data */
3957                         ret_val = YAFFS_OK;
3958                 else {
3959                         if (update_time)
3960                                 yaffs_load_current_time(in, 0, 0);
3961
3962                         ret_val = (yaffs_update_oh(in, NULL, 0, 0, 0, NULL) >=
3963                                    0) ? YAFFS_OK : YAFFS_FAIL;
3964                 }
3965         } else {
3966                 ret_val = YAFFS_OK;
3967         }
3968
3969         return ret_val;
3970
3971 }
3972
3973
3974 /* yaffs_del_file deletes the whole file data
3975  * and the inode associated with the file.
3976  * It does not delete the links associated with the file.
3977  */
3978 static int yaffs_unlink_file_if_needed(struct yaffs_obj *in)
3979 {
3980
3981         int ret_val;
3982         int del_now = 0;
3983         struct yaffs_dev *dev = in->my_dev;
3984
3985         if (!in->my_inode)
3986                 del_now = 1;
3987
3988         if (del_now) {
3989                 ret_val =
3990                     yaffs_change_obj_name(in, in->my_dev->del_dir,
3991                                           _Y("deleted"), 0, 0);
3992                 T(YAFFS_TRACE_TRACING,
3993                   (TSTR("yaffs: immediate deletion of file %d" TENDSTR),
3994                    in->obj_id));
3995                 in->deleted = 1;
3996                 in->my_dev->n_deleted_files++;
3997                 if (dev->param.disable_soft_del || dev->param.is_yaffs2)
3998                         yaffs_resize_file(in, 0);
3999                 yaffs_soft_del_file(in);
4000         } else {
4001                 ret_val =
4002                     yaffs_change_obj_name(in, in->my_dev->unlinked_dir,
4003                                           _Y("unlinked"), 0, 0);
4004         }
4005
4006         return ret_val;
4007 }
4008
4009 int yaffs_del_file(struct yaffs_obj *in)
4010 {
4011         int ret_val = YAFFS_OK;
4012         int deleted;            /* Need to cache value on stack if in is freed */
4013         struct yaffs_dev *dev = in->my_dev;
4014
4015         if (dev->param.disable_soft_del || dev->param.is_yaffs2)
4016                 yaffs_resize_file(in, 0);
4017
4018         if (in->n_data_chunks > 0) {
4019                 /* Use soft deletion if there is data in the file.
4020                  * That won't be the case if it has been resized to zero.
4021                  */
4022                 if (!in->unlinked)
4023                         ret_val = yaffs_unlink_file_if_needed(in);
4024
4025                 deleted = in->deleted;
4026
4027                 if (ret_val == YAFFS_OK && in->unlinked && !in->deleted) {
4028                         in->deleted = 1;
4029                         deleted = 1;
4030                         in->my_dev->n_deleted_files++;
4031                         yaffs_soft_del_file(in);
4032                 }
4033                 return deleted ? YAFFS_OK : YAFFS_FAIL;
4034         } else {
4035                 /* The file has no data chunks so we toss it immediately */
4036                 yaffs_free_tnode(in->my_dev, in->variant.file_variant.top);
4037                 in->variant.file_variant.top = NULL;
4038                 yaffs_generic_obj_del(in);
4039
4040                 return YAFFS_OK;
4041         }
4042 }
4043
4044 int yaffs_is_non_empty_dir(struct yaffs_obj *obj)
4045 {
4046         return (obj &&
4047                 obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY) &&
4048                 !(list_empty(&obj->variant.dir_variant.children));
4049 }
4050
4051 static int yaffs_del_dir(struct yaffs_obj *obj)
4052 {
4053         /* First check that the directory is empty. */
4054         if (yaffs_is_non_empty_dir(obj))
4055                 return YAFFS_FAIL;
4056
4057         return yaffs_generic_obj_del(obj);
4058 }
4059
4060 static int yaffs_del_symlink(struct yaffs_obj *in)
4061 {
4062         if (in->variant.symlink_variant.alias)
4063                 kfree(in->variant.symlink_variant.alias);
4064         in->variant.symlink_variant.alias = NULL;
4065
4066         return yaffs_generic_obj_del(in);
4067 }
4068
4069 static int yaffs_del_link(struct yaffs_obj *in)
4070 {
4071         /* remove this hardlink from the list assocaited with the equivalent
4072          * object
4073          */
4074         list_del_init(&in->hard_links);
4075         return yaffs_generic_obj_del(in);
4076 }
4077
4078 int yaffs_del_obj(struct yaffs_obj *obj)
4079 {
4080         int ret_val = -1;
4081         switch (obj->variant_type) {
4082         case YAFFS_OBJECT_TYPE_FILE:
4083                 ret_val = yaffs_del_file(obj);
4084                 break;
4085         case YAFFS_OBJECT_TYPE_DIRECTORY:
4086                 if (!list_empty(&obj->variant.dir_variant.dirty)) {
4087                         T(YAFFS_TRACE_BACKGROUND,
4088                           (TSTR
4089                            ("Remove object %d from dirty directories" TENDSTR),
4090                            obj->obj_id));
4091                         list_del_init(&obj->variant.dir_variant.dirty);
4092                 }
4093                 return yaffs_del_dir(obj);
4094                 break;
4095         case YAFFS_OBJECT_TYPE_SYMLINK:
4096                 ret_val = yaffs_del_symlink(obj);
4097                 break;
4098         case YAFFS_OBJECT_TYPE_HARDLINK:
4099                 ret_val = yaffs_del_link(obj);
4100                 break;
4101         case YAFFS_OBJECT_TYPE_SPECIAL:
4102                 ret_val = yaffs_generic_obj_del(obj);
4103                 break;
4104         case YAFFS_OBJECT_TYPE_UNKNOWN:
4105                 ret_val = 0;
4106                 break;          /* should not happen. */
4107         }
4108
4109         return ret_val;
4110 }
4111
4112 static int yaffs_unlink_worker(struct yaffs_obj *obj)
4113 {
4114
4115         int del_now = 0;
4116
4117         if (!obj->my_inode)
4118                 del_now = 1;
4119
4120         if (obj)
4121                 yaffs_update_parent(obj->parent);
4122
4123         if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
4124                 return yaffs_del_link(obj);
4125         } else if (!list_empty(&obj->hard_links)) {
4126                 /* Curve ball: We're unlinking an object that has a hardlink.
4127                  *
4128                  * This problem arises because we are not strictly following
4129                  * The Linux link/inode model.
4130                  *
4131                  * We can't really delete the object.
4132                  * Instead, we do the following:
4133                  * - Select a hardlink.
4134                  * - Unhook it from the hard links
4135                  * - Move it from its parent directory (so that the rename can work)
4136                  * - Rename the object to the hardlink's name.
4137                  * - Delete the hardlink
4138                  */
4139
4140                 struct yaffs_obj *hl;
4141                 struct yaffs_obj *parent;
4142                 int ret_val;
4143                 YCHAR name[YAFFS_MAX_NAME_LENGTH + 1];
4144
4145                 hl = list_entry(obj->hard_links.next, struct yaffs_obj,
4146                                 hard_links);
4147
4148                 yaffs_get_obj_name(hl, name, YAFFS_MAX_NAME_LENGTH + 1);
4149                 parent = hl->parent;
4150
4151                 list_del_init(&hl->hard_links);
4152
4153                 yaffs_add_obj_to_dir(obj->my_dev->unlinked_dir, hl);
4154
4155                 ret_val = yaffs_change_obj_name(obj, parent, name, 0, 0);
4156
4157                 if (ret_val == YAFFS_OK)
4158                         ret_val = yaffs_generic_obj_del(hl);
4159
4160                 return ret_val;
4161
4162         } else if (del_now) {
4163                 switch (obj->variant_type) {
4164                 case YAFFS_OBJECT_TYPE_FILE:
4165                         return yaffs_del_file(obj);
4166                         break;
4167                 case YAFFS_OBJECT_TYPE_DIRECTORY:
4168                         list_del_init(&obj->variant.dir_variant.dirty);
4169                         return yaffs_del_dir(obj);
4170                         break;
4171                 case YAFFS_OBJECT_TYPE_SYMLINK:
4172                         return yaffs_del_symlink(obj);
4173                         break;
4174                 case YAFFS_OBJECT_TYPE_SPECIAL:
4175                         return yaffs_generic_obj_del(obj);
4176                         break;
4177                 case YAFFS_OBJECT_TYPE_HARDLINK:
4178                 case YAFFS_OBJECT_TYPE_UNKNOWN:
4179                 default:
4180                         return YAFFS_FAIL;
4181                 }
4182         } else if (yaffs_is_non_empty_dir(obj)) {
4183                 return YAFFS_FAIL;
4184         } else {
4185                 return yaffs_change_obj_name(obj, obj->my_dev->unlinked_dir,
4186                                              _Y("unlinked"), 0, 0);
4187         }
4188 }
4189
4190 static int yaffs_unlink_obj(struct yaffs_obj *obj)
4191 {
4192
4193         if (obj && obj->unlink_allowed)
4194                 return yaffs_unlink_worker(obj);
4195
4196         return YAFFS_FAIL;
4197
4198 }
4199
4200 int yaffs_unlinker(struct yaffs_obj *dir, const YCHAR * name)
4201 {
4202         struct yaffs_obj *obj;
4203
4204         obj = yaffs_find_by_name(dir, name);
4205         return yaffs_unlink_obj(obj);
4206 }
4207
4208 /* Note:
4209  * If old_name is NULL then we take old_dir as the object to be renamed.
4210  */
4211 int yaffs_rename_obj(struct yaffs_obj *old_dir, const YCHAR * old_name,
4212                      struct yaffs_obj *new_dir, const YCHAR * new_name)
4213 {
4214         struct yaffs_obj *obj = NULL;
4215         struct yaffs_obj *existing_target = NULL;
4216         int force = 0;
4217         int result;
4218         struct yaffs_dev *dev;
4219
4220         if (!old_dir || old_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
4221                 YBUG();
4222         if (!new_dir || new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
4223                 YBUG();
4224
4225         dev = old_dir->my_dev;
4226
4227 #ifdef CONFIG_YAFFS_CASE_INSENSITIVE
4228         /* Special case for case insemsitive systems.
4229          * While look-up is case insensitive, the name isn't.
4230          * Therefore we might want to change x.txt to X.txt
4231          */
4232         if (old_dir == new_dir &&
4233                 old_name && new_name &&
4234                 strcmp(old_name, new_name) == 0)
4235                 force = 1;
4236 #endif
4237
4238         if (strnlen(new_name, YAFFS_MAX_NAME_LENGTH + 1) >
4239             YAFFS_MAX_NAME_LENGTH)
4240                 /* ENAMETOOLONG */
4241                 return YAFFS_FAIL;
4242
4243         if(old_name)
4244                 obj = yaffs_find_by_name(old_dir, old_name);
4245         else{
4246                 obj = old_dir;
4247                 old_dir = obj->parent;
4248         }
4249
4250
4251         if (obj && obj->rename_allowed) {
4252
4253                 /* Now do the handling for an existing target, if there is one */
4254
4255                 existing_target = yaffs_find_by_name(new_dir, new_name);
4256                 if (yaffs_is_non_empty_dir(existing_target)){
4257                         return YAFFS_FAIL;      /* ENOTEMPTY */
4258                 } else if (existing_target && existing_target != obj) {
4259                         /* Nuke the target first, using shadowing,
4260                          * but only if it isn't the same object.
4261                          *
4262                          * Note we must disable gc otherwise it can mess up the shadowing.
4263                          *
4264                          */
4265                         dev->gc_disable = 1;
4266                         yaffs_change_obj_name(obj, new_dir, new_name, force,
4267                                               existing_target->obj_id);
4268                         existing_target->is_shadowed = 1;
4269                         yaffs_unlink_obj(existing_target);
4270                         dev->gc_disable = 0;
4271                 }
4272
4273                 result = yaffs_change_obj_name(obj, new_dir, new_name, 1, 0);
4274
4275                 yaffs_update_parent(old_dir);
4276                 if (new_dir != old_dir)
4277                         yaffs_update_parent(new_dir);
4278
4279                 return result;
4280         }
4281         return YAFFS_FAIL;
4282 }
4283
4284 /*----------------------- Initialisation Scanning ---------------------- */
4285
4286 void yaffs_handle_shadowed_obj(struct yaffs_dev *dev, int obj_id,
4287                                int backward_scanning)
4288 {
4289         struct yaffs_obj *obj;
4290
4291         if (!backward_scanning) {
4292                 /* Handle YAFFS1 forward scanning case
4293                  * For YAFFS1 we always do the deletion
4294                  */
4295
4296         } else {
4297                 /* Handle YAFFS2 case (backward scanning)
4298                  * If the shadowed object exists then ignore.
4299                  */
4300                 obj = yaffs_find_by_number(dev, obj_id);
4301                 if (obj)
4302                         return;
4303         }
4304
4305         /* Let's create it (if it does not exist) assuming it is a file so that it can do shrinking etc.
4306          * We put it in unlinked dir to be cleaned up after the scanning
4307          */
4308         obj =
4309             yaffs_find_or_create_by_number(dev, obj_id, YAFFS_OBJECT_TYPE_FILE);
4310         if (!obj)
4311                 return;
4312         obj->is_shadowed = 1;
4313         yaffs_add_obj_to_dir(dev->unlinked_dir, obj);
4314         obj->variant.file_variant.shrink_size = 0;
4315         obj->valid = 1;         /* So that we don't read any other info for this file */
4316
4317 }
4318
4319 void yaffs_link_fixup(struct yaffs_dev *dev, struct yaffs_obj *hard_list)
4320 {
4321         struct yaffs_obj *hl;
4322         struct yaffs_obj *in;
4323
4324         while (hard_list) {
4325                 hl = hard_list;
4326                 hard_list = (struct yaffs_obj *)(hard_list->hard_links.next);
4327
4328                 in = yaffs_find_by_number(dev,
4329                                           hl->variant.
4330                                           hardlink_variant.equiv_id);
4331
4332                 if (in) {
4333                         /* Add the hardlink pointers */
4334                         hl->variant.hardlink_variant.equiv_obj = in;
4335                         list_add(&hl->hard_links, &in->hard_links);
4336                 } else {
4337                         /* Todo Need to report/handle this better.
4338                          * Got a problem... hardlink to a non-existant object
4339                          */
4340                         hl->variant.hardlink_variant.equiv_obj = NULL;
4341                         INIT_LIST_HEAD(&hl->hard_links);
4342
4343                 }
4344         }
4345 }
4346
4347 static void yaffs_strip_deleted_objs(struct yaffs_dev *dev)
4348 {
4349         /*
4350          *  Sort out state of unlinked and deleted objects after scanning.
4351          */
4352         struct list_head *i;
4353         struct list_head *n;
4354         struct yaffs_obj *l;
4355
4356         if (dev->read_only)
4357                 return;
4358
4359         /* Soft delete all the unlinked files */
4360         list_for_each_safe(i, n,
4361                            &dev->unlinked_dir->variant.dir_variant.children) {
4362                 if (i) {
4363                         l = list_entry(i, struct yaffs_obj, siblings);
4364                         yaffs_del_obj(l);
4365                 }
4366         }
4367
4368         list_for_each_safe(i, n, &dev->del_dir->variant.dir_variant.children) {
4369                 if (i) {
4370                         l = list_entry(i, struct yaffs_obj, siblings);
4371                         yaffs_del_obj(l);
4372                 }
4373         }
4374
4375 }
4376
4377 /*
4378  * This code iterates through all the objects making sure that they are rooted.
4379  * Any unrooted objects are re-rooted in lost+found.
4380  * An object needs to be in one of:
4381  * - Directly under deleted, unlinked
4382  * - Directly or indirectly under root.
4383  *
4384  * Note:
4385  *  This code assumes that we don't ever change the current relationships between
4386  *  directories:
4387  *   root_dir->parent == unlinked_dir->parent == del_dir->parent == NULL
4388  *   lost-n-found->parent == root_dir
4389  *
4390  * This fixes the problem where directories might have inadvertently been deleted
4391  * leaving the object "hanging" without being rooted in the directory tree.
4392  */
4393
4394 static int yaffs_has_null_parent(struct yaffs_dev *dev, struct yaffs_obj *obj)
4395 {
4396         return (obj == dev->del_dir ||
4397                 obj == dev->unlinked_dir || obj == dev->root_dir);
4398 }
4399
4400 static void yaffs_fix_hanging_objs(struct yaffs_dev *dev)
4401 {
4402         struct yaffs_obj *obj;
4403         struct yaffs_obj *parent;
4404         int i;
4405         struct list_head *lh;
4406         struct list_head *n;
4407         int depth_limit;
4408         int hanging;
4409
4410         if (dev->read_only)
4411                 return;
4412
4413         /* Iterate through the objects in each hash entry,
4414          * looking at each object.
4415          * Make sure it is rooted.
4416          */
4417
4418         for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
4419                 list_for_each_safe(lh, n, &dev->obj_bucket[i].list) {
4420                         if (lh) {
4421                                 obj =
4422                                     list_entry(lh, struct yaffs_obj, hash_link);
4423                                 parent = obj->parent;
4424
4425                                 if (yaffs_has_null_parent(dev, obj)) {
4426                                         /* These directories are not hanging */
4427                                         hanging = 0;
4428                                 } else if (!parent
4429                                            || parent->variant_type !=
4430                                            YAFFS_OBJECT_TYPE_DIRECTORY) {
4431                                         hanging = 1;
4432                                 } else if (yaffs_has_null_parent(dev, parent)) {
4433                                         hanging = 0;
4434                                 } else {
4435                                         /*
4436                                          * Need to follow the parent chain to see if it is hanging.
4437                                          */
4438                                         hanging = 0;
4439                                         depth_limit = 100;
4440
4441                                         while (parent != dev->root_dir &&
4442                                                parent->parent &&
4443                                                parent->parent->variant_type ==
4444                                                YAFFS_OBJECT_TYPE_DIRECTORY
4445                                                && depth_limit > 0) {
4446                                                 parent = parent->parent;
4447                                                 depth_limit--;
4448                                         }
4449                                         if (parent != dev->root_dir)
4450                                                 hanging = 1;
4451                                 }
4452                                 if (hanging) {
4453                                         T(YAFFS_TRACE_SCAN,
4454                                           (TSTR
4455                                            ("Hanging object %d moved to lost and found"
4456                                             TENDSTR), obj->obj_id));
4457                                         yaffs_add_obj_to_dir(dev->lost_n_found,
4458                                                              obj);
4459                                 }
4460                         }
4461                 }
4462         }
4463 }
4464
4465 /*
4466  * Delete directory contents for cleaning up lost and found.
4467  */
4468 static void yaffs_del_dir_contents(struct yaffs_obj *dir)
4469 {
4470         struct yaffs_obj *obj;
4471         struct list_head *lh;
4472         struct list_head *n;
4473
4474         if (dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
4475                 YBUG();
4476
4477         list_for_each_safe(lh, n, &dir->variant.dir_variant.children) {
4478                 if (lh) {
4479                         obj = list_entry(lh, struct yaffs_obj, siblings);
4480                         if (obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY)
4481                                 yaffs_del_dir_contents(obj);
4482
4483                         T(YAFFS_TRACE_SCAN,
4484                           (TSTR("Deleting lost_found object %d" TENDSTR),
4485                            obj->obj_id));
4486
4487                         /* Need to use UnlinkObject since Delete would not handle
4488                          * hardlinked objects correctly.
4489                          */
4490                         yaffs_unlink_obj(obj);
4491                 }
4492         }
4493
4494 }
4495
4496 static void yaffs_empty_l_n_f(struct yaffs_dev *dev)
4497 {
4498         yaffs_del_dir_contents(dev->lost_n_found);
4499 }
4500
4501
4502 struct yaffs_obj *yaffs_find_by_name(struct yaffs_obj *directory,
4503                                      const YCHAR * name)
4504 {
4505         int sum;
4506
4507         struct list_head *i;
4508         YCHAR buffer[YAFFS_MAX_NAME_LENGTH + 1];
4509
4510         struct yaffs_obj *l;
4511
4512         if (!name)
4513                 return NULL;
4514
4515         if (!directory) {
4516                 T(YAFFS_TRACE_ALWAYS,
4517                   (TSTR
4518                    ("tragedy: yaffs_find_by_name: null pointer directory"
4519                     TENDSTR)));
4520                 YBUG();
4521                 return NULL;
4522         }
4523         if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4524                 T(YAFFS_TRACE_ALWAYS,
4525                   (TSTR("tragedy: yaffs_find_by_name: non-directory" TENDSTR)));
4526                 YBUG();
4527         }
4528
4529         sum = yaffs_calc_name_sum(name);
4530
4531         list_for_each(i, &directory->variant.dir_variant.children) {
4532                 if (i) {
4533                         l = list_entry(i, struct yaffs_obj, siblings);
4534
4535                         if (l->parent != directory)
4536                                 YBUG();
4537
4538                         yaffs_check_obj_details_loaded(l);
4539
4540                         /* Special case for lost-n-found */
4541                         if (l->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
4542                                 if (!strcmp(name, YAFFS_LOSTNFOUND_NAME))
4543                                         return l;
4544                         } else if (l->sum == sum
4545                                    || l->hdr_chunk <= 0) {
4546                                 /* LostnFound chunk called Objxxx
4547                                  * Do a real check
4548                                  */
4549                                 yaffs_get_obj_name(l, buffer,
4550                                                    YAFFS_MAX_NAME_LENGTH + 1);
4551                                 if (strncmp
4552                                     (name, buffer, YAFFS_MAX_NAME_LENGTH) == 0)
4553                                         return l;
4554                         }
4555                 }
4556         }
4557
4558         return NULL;
4559 }
4560
4561 /* GetEquivalentObject dereferences any hard links to get to the
4562  * actual object.
4563  */
4564
4565 struct yaffs_obj *yaffs_get_equivalent_obj(struct yaffs_obj *obj)
4566 {
4567         if (obj && obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
4568                 /* We want the object id of the equivalent object, not this one */
4569                 obj = obj->variant.hardlink_variant.equiv_obj;
4570                 yaffs_check_obj_details_loaded(obj);
4571         }
4572         return obj;
4573 }
4574
4575 /*
4576  *  A note or two on object names.
4577  *  * If the object name is missing, we then make one up in the form objnnn
4578  *
4579  *  * ASCII names are stored in the object header's name field from byte zero
4580  *  * Unicode names are historically stored starting from byte zero.
4581  *
4582  * Then there are automatic Unicode names...
4583  * The purpose of these is to save names in a way that can be read as
4584  * ASCII or Unicode names as appropriate, thus allowing a Unicode and ASCII
4585  * system to share files.
4586  *
4587  * These automatic unicode are stored slightly differently...
4588  *  - If the name can fit in the ASCII character space then they are saved as
4589  *    ascii names as per above.
4590  *  - If the name needs Unicode then the name is saved in Unicode
4591  *    starting at oh->name[1].
4592
4593  */
4594 static void yaffs_fix_null_name(struct yaffs_obj *obj, YCHAR * name,
4595                                 int buffer_size)
4596 {
4597         /* Create an object name if we could not find one. */
4598         if (strnlen(name, YAFFS_MAX_NAME_LENGTH) == 0) {
4599                 YCHAR local_name[20];
4600                 YCHAR num_string[20];
4601                 YCHAR *x = &num_string[19];
4602                 unsigned v = obj->obj_id;
4603                 num_string[19] = 0;
4604                 while (v > 0) {
4605                         x--;
4606                         *x = '0' + (v % 10);
4607                         v /= 10;
4608                 }
4609                 /* make up a name */
4610                 strcpy(local_name, YAFFS_LOSTNFOUND_PREFIX);
4611                 strcat(local_name, x);
4612                 strncpy(name, local_name, buffer_size - 1);
4613         }
4614 }
4615
4616 int yaffs_get_obj_name(struct yaffs_obj *obj, YCHAR * name, int buffer_size)
4617 {
4618         memset(name, 0, buffer_size * sizeof(YCHAR));
4619
4620         yaffs_check_obj_details_loaded(obj);
4621
4622         if (obj->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
4623                 strncpy(name, YAFFS_LOSTNFOUND_NAME, buffer_size - 1);
4624         }
4625 #ifndef CONFIG_YAFFS_NO_SHORT_NAMES
4626         else if (obj->short_name[0]) {
4627                 strcpy(name, obj->short_name);
4628         }
4629 #endif
4630         else if (obj->hdr_chunk > 0) {
4631                 int result;
4632                 u8 *buffer = yaffs_get_temp_buffer(obj->my_dev, __LINE__);
4633
4634                 struct yaffs_obj_hdr *oh = (struct yaffs_obj_hdr *)buffer;
4635
4636                 memset(buffer, 0, obj->my_dev->data_bytes_per_chunk);
4637
4638                 if (obj->hdr_chunk > 0) {
4639                         result = yaffs_rd_chunk_tags_nand(obj->my_dev,
4640                                                           obj->hdr_chunk,
4641                                                           buffer, NULL);
4642                 }
4643                 yaffs_load_name_from_oh(obj->my_dev, name, oh->name,
4644                                         buffer_size);
4645
4646                 yaffs_release_temp_buffer(obj->my_dev, buffer, __LINE__);
4647         }
4648
4649         yaffs_fix_null_name(obj, name, buffer_size);
4650
4651         return strnlen(name, YAFFS_MAX_NAME_LENGTH);
4652 }
4653
4654 int yaffs_get_obj_length(struct yaffs_obj *obj)
4655 {
4656         /* Dereference any hard linking */
4657         obj = yaffs_get_equivalent_obj(obj);
4658
4659         if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
4660                 return obj->variant.file_variant.file_size;
4661         if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
4662                 if (!obj->variant.symlink_variant.alias)
4663                         return 0;
4664                 return strnlen(obj->variant.symlink_variant.alias,
4665                                      YAFFS_MAX_ALIAS_LENGTH);
4666         } else {
4667                 /* Only a directory should drop through to here */
4668                 return obj->my_dev->data_bytes_per_chunk;
4669         }
4670 }
4671
4672 int yaffs_get_obj_link_count(struct yaffs_obj *obj)
4673 {
4674         int count = 0;
4675         struct list_head *i;
4676
4677         if (!obj->unlinked)
4678                 count++;        /* the object itself */
4679
4680         list_for_each(i, &obj->hard_links)
4681             count++;            /* add the hard links; */
4682
4683         return count;
4684 }
4685
4686 int yaffs_get_obj_inode(struct yaffs_obj *obj)
4687 {
4688         obj = yaffs_get_equivalent_obj(obj);
4689
4690         return obj->obj_id;
4691 }
4692
4693 unsigned yaffs_get_obj_type(struct yaffs_obj *obj)
4694 {
4695         obj = yaffs_get_equivalent_obj(obj);
4696
4697         switch (obj->variant_type) {
4698         case YAFFS_OBJECT_TYPE_FILE:
4699                 return DT_REG;
4700                 break;
4701         case YAFFS_OBJECT_TYPE_DIRECTORY:
4702                 return DT_DIR;
4703                 break;
4704         case YAFFS_OBJECT_TYPE_SYMLINK:
4705                 return DT_LNK;
4706                 break;
4707         case YAFFS_OBJECT_TYPE_HARDLINK:
4708                 return DT_REG;
4709                 break;
4710         case YAFFS_OBJECT_TYPE_SPECIAL:
4711                 if (S_ISFIFO(obj->yst_mode))
4712                         return DT_FIFO;
4713                 if (S_ISCHR(obj->yst_mode))
4714                         return DT_CHR;
4715                 if (S_ISBLK(obj->yst_mode))
4716                         return DT_BLK;
4717                 if (S_ISSOCK(obj->yst_mode))
4718                         return DT_SOCK;
4719         default:
4720                 return DT_REG;
4721                 break;
4722         }
4723 }
4724
4725 YCHAR *yaffs_get_symlink_alias(struct yaffs_obj *obj)
4726 {
4727         obj = yaffs_get_equivalent_obj(obj);
4728         if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK)
4729                 return yaffs_clone_str(obj->variant.symlink_variant.alias);
4730         else
4731                 return yaffs_clone_str(_Y(""));
4732 }
4733
4734 /*--------------------------- Initialisation code -------------------------- */
4735
4736 static int yaffs_check_dev_fns(const struct yaffs_dev *dev)
4737 {
4738
4739         /* Common functions, gotta have */
4740         if (!dev->param.erase_fn || !dev->param.initialise_flash_fn)
4741                 return 0;
4742
4743 #ifdef CONFIG_YAFFS_YAFFS2
4744
4745         /* Can use the "with tags" style interface for yaffs1 or yaffs2 */
4746         if (dev->param.write_chunk_tags_fn &&
4747             dev->param.read_chunk_tags_fn &&
4748             !dev->param.write_chunk_fn &&
4749             !dev->param.read_chunk_fn &&
4750             dev->param.bad_block_fn && dev->param.query_block_fn)
4751                 return 1;
4752 #endif
4753
4754         /* Can use the "spare" style interface for yaffs1 */
4755         if (!dev->param.is_yaffs2 &&
4756             !dev->param.write_chunk_tags_fn &&
4757             !dev->param.read_chunk_tags_fn &&
4758             dev->param.write_chunk_fn &&
4759             dev->param.read_chunk_fn &&
4760             !dev->param.bad_block_fn && !dev->param.query_block_fn)
4761                 return 1;
4762
4763         return 0;               /* bad */
4764 }
4765
4766 static int yaffs_create_initial_dir(struct yaffs_dev *dev)
4767 {
4768         /* Initialise the unlinked, deleted, root and lost and found directories */
4769
4770         dev->lost_n_found = dev->root_dir = NULL;
4771         dev->unlinked_dir = dev->del_dir = NULL;
4772
4773         dev->unlinked_dir =
4774             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_UNLINKED, S_IFDIR);
4775
4776         dev->del_dir =
4777             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_DELETED, S_IFDIR);
4778
4779         dev->root_dir =
4780             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_ROOT,
4781                                   YAFFS_ROOT_MODE | S_IFDIR);
4782         dev->lost_n_found =
4783             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_LOSTNFOUND,
4784                                   YAFFS_LOSTNFOUND_MODE | S_IFDIR);
4785
4786         if (dev->lost_n_found && dev->root_dir && dev->unlinked_dir
4787             && dev->del_dir) {
4788                 yaffs_add_obj_to_dir(dev->root_dir, dev->lost_n_found);
4789                 return YAFFS_OK;
4790         }
4791
4792         return YAFFS_FAIL;
4793 }
4794
4795 int yaffs_guts_initialise(struct yaffs_dev *dev)
4796 {
4797         int init_failed = 0;
4798         unsigned x;
4799         int bits;
4800
4801         T(YAFFS_TRACE_TRACING,
4802           (TSTR("yaffs: yaffs_guts_initialise()" TENDSTR)));
4803
4804         /* Check stuff that must be set */
4805
4806         if (!dev) {
4807                 T(YAFFS_TRACE_ALWAYS, (TSTR("yaffs: Need a device" TENDSTR)));
4808                 return YAFFS_FAIL;
4809         }
4810
4811         dev->internal_start_block = dev->param.start_block;
4812         dev->internal_end_block = dev->param.end_block;
4813         dev->block_offset = 0;
4814         dev->chunk_offset = 0;
4815         dev->n_free_chunks = 0;
4816
4817         dev->gc_block = 0;
4818
4819         if (dev->param.start_block == 0) {
4820                 dev->internal_start_block = dev->param.start_block + 1;
4821                 dev->internal_end_block = dev->param.end_block + 1;
4822                 dev->block_offset = 1;
4823                 dev->chunk_offset = dev->param.chunks_per_block;
4824         }
4825
4826         /* Check geometry parameters. */
4827
4828         if ((!dev->param.inband_tags && dev->param.is_yaffs2 && dev->param.total_bytes_per_chunk < 1024) || (!dev->param.is_yaffs2 && dev->param.total_bytes_per_chunk < 512) || (dev->param.inband_tags && !dev->param.is_yaffs2) || dev->param.chunks_per_block < 2 || dev->param.n_reserved_blocks < 2 || dev->internal_start_block <= 0 || dev->internal_end_block <= 0 || dev->internal_end_block <= (dev->internal_start_block + dev->param.n_reserved_blocks + 2)) {     /* otherwise it is too small */
4829                 T(YAFFS_TRACE_ALWAYS,
4830                   (TSTR
4831                    ("yaffs: NAND geometry problems: chunk size %d, type is yaffs%s, inband_tags %d "
4832                     TENDSTR), dev->param.total_bytes_per_chunk,
4833                    dev->param.is_yaffs2 ? "2" : "", dev->param.inband_tags));
4834                 return YAFFS_FAIL;
4835         }
4836
4837         if (yaffs_init_nand(dev) != YAFFS_OK) {
4838                 T(YAFFS_TRACE_ALWAYS,
4839                   (TSTR("yaffs: InitialiseNAND failed" TENDSTR)));
4840                 return YAFFS_FAIL;
4841         }
4842
4843         /* Sort out space for inband tags, if required */
4844         if (dev->param.inband_tags)
4845                 dev->data_bytes_per_chunk =
4846                     dev->param.total_bytes_per_chunk -
4847                     sizeof(struct yaffs_packed_tags2_tags_only);
4848         else
4849                 dev->data_bytes_per_chunk = dev->param.total_bytes_per_chunk;
4850
4851         /* Got the right mix of functions? */
4852         if (!yaffs_check_dev_fns(dev)) {
4853                 /* Function missing */
4854                 T(YAFFS_TRACE_ALWAYS,
4855                   (TSTR
4856                    ("yaffs: device function(s) missing or wrong\n" TENDSTR)));
4857
4858                 return YAFFS_FAIL;
4859         }
4860
4861         if (dev->is_mounted) {
4862                 T(YAFFS_TRACE_ALWAYS,
4863                   (TSTR("yaffs: device already mounted\n" TENDSTR)));
4864                 return YAFFS_FAIL;
4865         }
4866
4867         /* Finished with most checks. One or two more checks happen later on too. */
4868
4869         dev->is_mounted = 1;
4870
4871         /* OK now calculate a few things for the device */
4872
4873         /*
4874          *  Calculate all the chunk size manipulation numbers:
4875          */
4876         x = dev->data_bytes_per_chunk;
4877         /* We always use dev->chunk_shift and dev->chunk_div */
4878         dev->chunk_shift = calc_shifts(x);
4879         x >>= dev->chunk_shift;
4880         dev->chunk_div = x;
4881         /* We only use chunk mask if chunk_div is 1 */
4882         dev->chunk_mask = (1 << dev->chunk_shift) - 1;
4883
4884         /*
4885          * Calculate chunk_grp_bits.
4886          * We need to find the next power of 2 > than internal_end_block
4887          */
4888
4889         x = dev->param.chunks_per_block * (dev->internal_end_block + 1);
4890
4891         bits = calc_shifts_ceiling(x);
4892
4893         /* Set up tnode width if wide tnodes are enabled. */
4894         if (!dev->param.wide_tnodes_disabled) {
4895                 /* bits must be even so that we end up with 32-bit words */
4896                 if (bits & 1)
4897                         bits++;
4898                 if (bits < 16)
4899                         dev->tnode_width = 16;
4900                 else
4901                         dev->tnode_width = bits;
4902         } else {
4903                 dev->tnode_width = 16;
4904         }
4905
4906         dev->tnode_mask = (1 << dev->tnode_width) - 1;
4907
4908         /* Level0 Tnodes are 16 bits or wider (if wide tnodes are enabled),
4909          * so if the bitwidth of the
4910          * chunk range we're using is greater than 16 we need
4911          * to figure out chunk shift and chunk_grp_size
4912          */
4913
4914         if (bits <= dev->tnode_width)
4915                 dev->chunk_grp_bits = 0;
4916         else
4917                 dev->chunk_grp_bits = bits - dev->tnode_width;
4918
4919         dev->tnode_size = (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8;
4920         if (dev->tnode_size < sizeof(struct yaffs_tnode))
4921                 dev->tnode_size = sizeof(struct yaffs_tnode);
4922
4923         dev->chunk_grp_size = 1 << dev->chunk_grp_bits;
4924
4925         if (dev->param.chunks_per_block < dev->chunk_grp_size) {
4926                 /* We have a problem because the soft delete won't work if
4927                  * the chunk group size > chunks per block.
4928                  * This can be remedied by using larger "virtual blocks".
4929                  */
4930                 T(YAFFS_TRACE_ALWAYS,
4931                   (TSTR("yaffs: chunk group too large\n" TENDSTR)));
4932
4933                 return YAFFS_FAIL;
4934         }
4935
4936         /* OK, we've finished verifying the device, lets continue with initialisation */
4937
4938         /* More device initialisation */
4939         dev->all_gcs = 0;
4940         dev->passive_gc_count = 0;
4941         dev->oldest_dirty_gc_count = 0;
4942         dev->bg_gcs = 0;
4943         dev->gc_block_finder = 0;
4944         dev->buffered_block = -1;
4945         dev->doing_buffered_block_rewrite = 0;
4946         dev->n_deleted_files = 0;
4947         dev->n_bg_deletions = 0;
4948         dev->n_unlinked_files = 0;
4949         dev->n_ecc_fixed = 0;
4950         dev->n_ecc_unfixed = 0;
4951         dev->n_tags_ecc_fixed = 0;
4952         dev->n_tags_ecc_unfixed = 0;
4953         dev->n_erase_failures = 0;
4954         dev->n_erased_blocks = 0;
4955         dev->gc_disable = 0;
4956         dev->has_pending_prioritised_gc = 1;    /* Assume the worst for now, will get fixed on first GC */
4957         INIT_LIST_HEAD(&dev->dirty_dirs);
4958         dev->oldest_dirty_seq = 0;
4959         dev->oldest_dirty_block = 0;
4960
4961         /* Initialise temporary buffers and caches. */
4962         if (!yaffs_init_tmp_buffers(dev))
4963                 init_failed = 1;
4964
4965         dev->cache = NULL;
4966         dev->gc_cleanup_list = NULL;
4967
4968         if (!init_failed && dev->param.n_caches > 0) {
4969                 int i;
4970                 void *buf;
4971                 int cache_bytes =
4972                     dev->param.n_caches * sizeof(struct yaffs_cache);
4973
4974                 if (dev->param.n_caches > YAFFS_MAX_SHORT_OP_CACHES)
4975                         dev->param.n_caches = YAFFS_MAX_SHORT_OP_CACHES;
4976
4977                 dev->cache = kmalloc(cache_bytes, GFP_NOFS);
4978
4979                 buf = (u8 *) dev->cache;
4980
4981                 if (dev->cache)
4982                         memset(dev->cache, 0, cache_bytes);
4983
4984                 for (i = 0; i < dev->param.n_caches && buf; i++) {
4985                         dev->cache[i].object = NULL;
4986                         dev->cache[i].last_use = 0;
4987                         dev->cache[i].dirty = 0;
4988                         dev->cache[i].data = buf =
4989                             kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
4990                 }
4991                 if (!buf)
4992                         init_failed = 1;
4993
4994                 dev->cache_last_use = 0;
4995         }
4996
4997         dev->cache_hits = 0;
4998
4999         if (!init_failed) {
5000                 dev->gc_cleanup_list =
5001                     kmalloc(dev->param.chunks_per_block * sizeof(u32),
5002                                         GFP_NOFS);
5003                 if (!dev->gc_cleanup_list)
5004                         init_failed = 1;
5005         }
5006
5007         if (dev->param.is_yaffs2)
5008                 dev->param.use_header_file_size = 1;
5009
5010         if (!init_failed && !yaffs_init_blocks(dev))
5011                 init_failed = 1;
5012
5013         yaffs_init_tnodes_and_objs(dev);
5014
5015         if (!init_failed && !yaffs_create_initial_dir(dev))
5016                 init_failed = 1;
5017
5018         if (!init_failed) {
5019                 /* Now scan the flash. */
5020                 if (dev->param.is_yaffs2) {
5021                         if (yaffs2_checkpt_restore(dev)) {
5022                                 yaffs_check_obj_details_loaded(dev->root_dir);
5023                                 T(YAFFS_TRACE_CHECKPOINT | YAFFS_TRACE_MOUNT,
5024                                   (TSTR
5025                                    ("yaffs: restored from checkpoint"
5026                                     TENDSTR)));
5027                         } else {
5028
5029                                 /* Clean up the mess caused by an aborted checkpoint load
5030                                  * and scan backwards.
5031                                  */
5032                                 yaffs_deinit_blocks(dev);
5033
5034                                 yaffs_deinit_tnodes_and_objs(dev);
5035
5036                                 dev->n_erased_blocks = 0;
5037                                 dev->n_free_chunks = 0;
5038                                 dev->alloc_block = -1;
5039                                 dev->alloc_page = -1;
5040                                 dev->n_deleted_files = 0;
5041                                 dev->n_unlinked_files = 0;
5042                                 dev->n_bg_deletions = 0;
5043
5044                                 if (!init_failed && !yaffs_init_blocks(dev))
5045                                         init_failed = 1;
5046
5047                                 yaffs_init_tnodes_and_objs(dev);
5048
5049                                 if (!init_failed
5050                                     && !yaffs_create_initial_dir(dev))
5051                                         init_failed = 1;
5052
5053                                 if (!init_failed && !yaffs2_scan_backwards(dev))
5054                                         init_failed = 1;
5055                         }
5056                 } else if (!yaffs1_scan(dev)) {
5057                         init_failed = 1;
5058                 }
5059
5060                 yaffs_strip_deleted_objs(dev);
5061                 yaffs_fix_hanging_objs(dev);
5062                 if (dev->param.empty_lost_n_found)
5063                         yaffs_empty_l_n_f(dev);
5064         }
5065
5066         if (init_failed) {
5067                 /* Clean up the mess */
5068                 T(YAFFS_TRACE_TRACING,
5069                   (TSTR("yaffs: yaffs_guts_initialise() aborted.\n" TENDSTR)));
5070
5071                 yaffs_deinitialise(dev);
5072                 return YAFFS_FAIL;
5073         }
5074
5075         /* Zero out stats */
5076         dev->n_page_reads = 0;
5077         dev->n_page_writes = 0;
5078         dev->n_erasures = 0;
5079         dev->n_gc_copies = 0;
5080         dev->n_retired_writes = 0;
5081
5082         dev->n_retired_blocks = 0;
5083
5084         yaffs_verify_free_chunks(dev);
5085         yaffs_verify_blocks(dev);
5086
5087         /* Clean up any aborted checkpoint data */
5088         if (!dev->is_checkpointed && dev->blocks_in_checkpt > 0)
5089                 yaffs2_checkpt_invalidate(dev);
5090
5091         T(YAFFS_TRACE_TRACING,
5092           (TSTR("yaffs: yaffs_guts_initialise() done.\n" TENDSTR)));
5093         return YAFFS_OK;
5094
5095 }
5096
5097 void yaffs_deinitialise(struct yaffs_dev *dev)
5098 {
5099         if (dev->is_mounted) {
5100                 int i;
5101
5102                 yaffs_deinit_blocks(dev);
5103                 yaffs_deinit_tnodes_and_objs(dev);
5104                 if (dev->param.n_caches > 0 && dev->cache) {
5105
5106                         for (i = 0; i < dev->param.n_caches; i++) {
5107                                 if (dev->cache[i].data)
5108                                         kfree(dev->cache[i].data);
5109                                 dev->cache[i].data = NULL;
5110                         }
5111
5112                         kfree(dev->cache);
5113                         dev->cache = NULL;
5114                 }
5115
5116                 kfree(dev->gc_cleanup_list);
5117
5118                 for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++)
5119                         kfree(dev->temp_buffer[i].buffer);
5120
5121                 dev->is_mounted = 0;
5122
5123                 if (dev->param.deinitialise_flash_fn)
5124                         dev->param.deinitialise_flash_fn(dev);
5125         }
5126 }
5127
5128 int yaffs_count_free_chunks(struct yaffs_dev *dev)
5129 {
5130         int n_free = 0;
5131         int b;
5132
5133         struct yaffs_block_info *blk;
5134
5135         blk = dev->block_info;
5136         for (b = dev->internal_start_block; b <= dev->internal_end_block; b++) {
5137                 switch (blk->block_state) {
5138                 case YAFFS_BLOCK_STATE_EMPTY:
5139                 case YAFFS_BLOCK_STATE_ALLOCATING:
5140                 case YAFFS_BLOCK_STATE_COLLECTING:
5141                 case YAFFS_BLOCK_STATE_FULL:
5142                         n_free +=
5143                             (dev->param.chunks_per_block - blk->pages_in_use +
5144                              blk->soft_del_pages);
5145                         break;
5146                 default:
5147                         break;
5148                 }
5149                 blk++;
5150         }
5151
5152         return n_free;
5153 }
5154
5155 int yaffs_get_n_free_chunks(struct yaffs_dev *dev)
5156 {
5157         /* This is what we report to the outside world */
5158
5159         int n_free;
5160         int n_dirty_caches;
5161         int blocks_for_checkpt;
5162         int i;
5163
5164         n_free = dev->n_free_chunks;
5165         n_free += dev->n_deleted_files;
5166
5167         /* Now count the number of dirty chunks in the cache and subtract those */
5168
5169         for (n_dirty_caches = 0, i = 0; i < dev->param.n_caches; i++) {
5170                 if (dev->cache[i].dirty)
5171                         n_dirty_caches++;
5172         }
5173
5174         n_free -= n_dirty_caches;
5175
5176         n_free -=
5177             ((dev->param.n_reserved_blocks + 1) * dev->param.chunks_per_block);
5178
5179         /* Now we figure out how much to reserve for the checkpoint and report that... */
5180         blocks_for_checkpt = yaffs_calc_checkpt_blocks_required(dev);
5181
5182         n_free -= (blocks_for_checkpt * dev->param.chunks_per_block);
5183
5184         if (n_free < 0)
5185                 n_free = 0;
5186
5187         return n_free;
5188
5189 }