yaffs_guts.c

   1 /*
   2  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
   3  *
   4  * Copyright (C) 2002-2011 Aleph One Ltd.
   5  *   for Toby Churchill Ltd and Brightstar Engineering
   6  *
   7  * Created by Charles Manning <charles@aleph1.co.uk>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #include "yportenv.h"
  15 #include "yaffs_trace.h"
  16
  17 #include "yaffs_guts.h"
  18 #include "yaffs_getblockinfo.h"
  19 #include "yaffs_tagscompat.h"
  20 #include "yaffs_nand.h"
  21 #include "yaffs_yaffs1.h"
  22 #include "yaffs_yaffs2.h"
  23 #include "yaffs_bitmap.h"
  24 #include "yaffs_verify.h"
  25 #include "yaffs_nand.h"
  26 #include "yaffs_packedtags2.h"
  27 #include "yaffs_nameval.h"
  28 #include "yaffs_allocator.h"
  29 #include "yaffs_attribs.h"
  30 #include "yaffs_summary.h"
  31
  32 /* Note YAFFS_GC_GOOD_ENOUGH must be <= YAFFS_GC_PASSIVE_THRESHOLD */
  33 #define YAFFS_GC_GOOD_ENOUGH 2
  34 #define YAFFS_GC_PASSIVE_THRESHOLD 4
  35
  36 #include "yaffs_ecc.h"
  37
  38 /* Forward declarations */
  39
  40 static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
  41                              const u8 *buffer, int n_bytes, int use_reserve);
  42
  43
  44
  45 /* Function to calculate chunk and offset */
  46
  47 void yaffs_addr_to_chunk(struct yaffs_dev *dev, loff_t addr,
  48                                 int *chunk_out, u32 *offset_out)
  49 {
  50         int chunk;
  51         u32 offset;
  52
  53         chunk = (u32) (addr >> dev->chunk_shift);
  54
  55         if (dev->chunk_div == 1) {
  56                 /* easy power of 2 case */
  57                 offset = (u32) (addr & dev->chunk_mask);
  58         } else {
  59                 /* Non power-of-2 case */
  60
  61                 loff_t chunk_base;
  62
  63                 chunk /= dev->chunk_div;
  64
  65                 chunk_base = ((loff_t) chunk) * dev->data_bytes_per_chunk;
  66                 offset = (u32) (addr - chunk_base);
  67         }
  68
  69         *chunk_out = chunk;
  70         *offset_out = offset;
  71 }
  72
  73 /* Function to return the number of shifts for a power of 2 greater than or
  74  * equal to the given number
  75  * Note we don't try to cater for all possible numbers and this does not have to
  76  * be hellishly efficient.
  77  */
  78
  79 static inline u32 calc_shifts_ceiling(u32 x)
  80 {
  81         int extra_bits;
  82         int shifts;
  83
  84         shifts = extra_bits = 0;
  85
  86         while (x > 1) {
  87                 if (x & 1)
  88                         extra_bits++;
  89                 x >>= 1;
  90                 shifts++;
  91         }
  92
  93         if (extra_bits)
  94                 shifts++;
  95
  96         return shifts;
  97 }
  98
  99 /* Function to return the number of shifts to get a 1 in bit 0
 100  */
 101
 102 static inline u32 calc_shifts(u32 x)
 103 {
 104         u32 shifts;
 105
 106         shifts = 0;
 107
 108         if (!x)
 109                 return 0;
 110
 111         while (!(x & 1)) {
 112                 x >>= 1;
 113                 shifts++;
 114         }
 115
 116         return shifts;
 117 }
 118
 119 /*
 120  * Temporary buffer manipulations.
 121  */
 122
 123 static int yaffs_init_tmp_buffers(struct yaffs_dev *dev)
 124 {
 125         int i;
 126         u8 *buf = (u8 *) 1;
 127
 128         memset(dev->temp_buffer, 0, sizeof(dev->temp_buffer));
 129
 130         for (i = 0; buf && i < YAFFS_N_TEMP_BUFFERS; i++) {
 131                 dev->temp_buffer[i].in_use = 0;
 132                 buf = kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
 133                 dev->temp_buffer[i].buffer = buf;
 134         }
 135
 136         return buf ? YAFFS_OK : YAFFS_FAIL;
 137 }
 138
 139 u8 *yaffs_get_temp_buffer(struct yaffs_dev * dev)
 140 {
 141         int i;
 142
 143         dev->temp_in_use++;
 144         if (dev->temp_in_use > dev->max_temp)
 145                 dev->max_temp = dev->temp_in_use;
 146
 147         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
 148                 if (dev->temp_buffer[i].in_use == 0) {
 149                         dev->temp_buffer[i].in_use = 1;
 150                         return dev->temp_buffer[i].buffer;
 151                 }
 152         }
 153
 154         yaffs_trace(YAFFS_TRACE_BUFFERS, "Out of temp buffers");
 155         /*
 156          * If we got here then we have to allocate an unmanaged one
 157          * This is not good.
 158          */
 159
 160         dev->unmanaged_buffer_allocs++;
 161         return kmalloc(dev->data_bytes_per_chunk, GFP_NOFS);
 162
 163 }
 164
 165 void yaffs_release_temp_buffer(struct yaffs_dev *dev, u8 *buffer)
 166 {
 167         int i;
 168
 169         dev->temp_in_use--;
 170
 171         for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
 172                 if (dev->temp_buffer[i].buffer == buffer) {
 173                         dev->temp_buffer[i].in_use = 0;
 174                         return;
 175                 }
 176         }
 177
 178         if (buffer) {
 179                 /* assume it is an unmanaged one. */
 180                 yaffs_trace(YAFFS_TRACE_BUFFERS,
 181                         "Releasing unmanaged temp buffer");
 182                 kfree(buffer);
 183                 dev->unmanaged_buffer_deallocs++;
 184         }
 185
 186 }
 187
 188 /*
 189  * Functions for robustisizing TODO
 190  *
 191  */
 192
 193 static void yaffs_handle_chunk_wr_ok(struct yaffs_dev *dev, int nand_chunk,
 194                                      const u8 *data,
 195                                      const struct yaffs_ext_tags *tags)
 196 {
 197         (void) dev;
 198         (void) nand_chunk;
 199         (void) data;
 200         (void) tags;
 201 }
 202
 203 static void yaffs_handle_chunk_update(struct yaffs_dev *dev, int nand_chunk,
 204                                       const struct yaffs_ext_tags *tags)
 205 {
 206         (void) dev;
 207         (void) nand_chunk;
 208         (void) tags;
 209 }
 210
 211 void yaffs_handle_chunk_error(struct yaffs_dev *dev,
 212                               struct yaffs_block_info *bi)
 213 {
 214         if (!bi->gc_prioritise) {
 215                 bi->gc_prioritise = 1;
 216                 dev->has_pending_prioritised_gc = 1;
 217                 bi->chunk_error_strikes++;
 218
 219                 if (bi->chunk_error_strikes > 3) {
 220                         bi->needs_retiring = 1; /* Too many stikes, so retire */
 221                         yaffs_trace(YAFFS_TRACE_ALWAYS,
 222                                 "yaffs: Block struck out");
 223
 224                 }
 225         }
 226 }
 227
 228 static void yaffs_handle_chunk_wr_error(struct yaffs_dev *dev, int nand_chunk,
 229                                         int erased_ok)
 230 {
 231         int flash_block = nand_chunk / dev->param.chunks_per_block;
 232         struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
 233
 234         yaffs_handle_chunk_error(dev, bi);
 235
 236         if (erased_ok) {
 237                 /* Was an actual write failure,
 238                  * so mark the block for retirement.*/
 239                 bi->needs_retiring = 1;
 240                 yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
 241                   "**>> Block %d needs retiring", flash_block);
 242         }
 243
 244         /* Delete the chunk */
 245         yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
 246         yaffs_skip_rest_of_block(dev);
 247 }
 248
 249 /*
 250  * Verification code
 251  */
 252
 253 /*
 254  *  Simple hash function. Needs to have a reasonable spread
 255  */
 256
 257 static inline int yaffs_hash_fn(int n)
 258 {
 259         if (n < 0)
 260                 n = -n;
 261         return n % YAFFS_NOBJECT_BUCKETS;
 262 }
 263
 264 /*
 265  * Access functions to useful fake objects.
 266  * Note that root might have a presence in NAND if permissions are set.
 267  */
 268
 269 struct yaffs_obj *yaffs_root(struct yaffs_dev *dev)
 270 {
 271         return dev->root_dir;
 272 }
 273
 274 struct yaffs_obj *yaffs_lost_n_found(struct yaffs_dev *dev)
 275 {
 276         return dev->lost_n_found;
 277 }
 278
 279 /*
 280  *  Erased NAND checking functions
 281  */
 282
 283 int yaffs_check_ff(u8 *buffer, int n_bytes)
 284 {
 285         /* Horrible, slow implementation */
 286         while (n_bytes--) {
 287                 if (*buffer != 0xff)
 288                         return 0;
 289                 buffer++;
 290         }
 291         return 1;
 292 }
 293
 294 static int yaffs_check_chunk_erased(struct yaffs_dev *dev, int nand_chunk)
 295 {
 296         int retval = YAFFS_OK;
 297         u8 *data = yaffs_get_temp_buffer(dev);
 298         struct yaffs_ext_tags tags;
 299         int result;
 300
 301         result = yaffs_rd_chunk_tags_nand(dev, nand_chunk, data, &tags);
 302
 303         if (tags.ecc_result > YAFFS_ECC_RESULT_NO_ERROR)
 304                 retval = YAFFS_FAIL;
 305
 306         if (!yaffs_check_ff(data, dev->data_bytes_per_chunk) ||
 307                 tags.chunk_used) {
 308                 yaffs_trace(YAFFS_TRACE_NANDACCESS,
 309                         "Chunk %d not erased", nand_chunk);
 310                 retval = YAFFS_FAIL;
 311         }
 312
 313         yaffs_release_temp_buffer(dev, data);
 314
 315         return retval;
 316
 317 }
 318
 319 static int yaffs_verify_chunk_written(struct yaffs_dev *dev,
 320                                       int nand_chunk,
 321                                       const u8 *data,
 322                                       struct yaffs_ext_tags *tags)
 323 {
 324         int retval = YAFFS_OK;
 325         struct yaffs_ext_tags temp_tags;
 326         u8 *buffer = yaffs_get_temp_buffer(dev);
 327         int result;
 328
 329         result = yaffs_rd_chunk_tags_nand(dev, nand_chunk, buffer, &temp_tags);
 330         if (memcmp(buffer, data, dev->data_bytes_per_chunk) ||
 331             temp_tags.obj_id != tags->obj_id ||
 332             temp_tags.chunk_id != tags->chunk_id ||
 333             temp_tags.n_bytes != tags->n_bytes)
 334                 retval = YAFFS_FAIL;
 335
 336         yaffs_release_temp_buffer(dev, buffer);
 337
 338         return retval;
 339 }
 340
 341
 342 int yaffs_check_alloc_available(struct yaffs_dev *dev, int n_chunks)
 343 {
 344         int reserved_chunks;
 345         int reserved_blocks = dev->param.n_reserved_blocks;
 346         int checkpt_blocks;
 347
 348         checkpt_blocks = yaffs_calc_checkpt_blocks_required(dev);
 349
 350         reserved_chunks =
 351             (reserved_blocks + checkpt_blocks) * dev->param.chunks_per_block;
 352
 353         return (dev->n_free_chunks > (reserved_chunks + n_chunks));
 354 }
 355
 356 static int yaffs_find_alloc_block(struct yaffs_dev *dev)
 357 {
 358         int i;
 359         struct yaffs_block_info *bi;
 360
 361         if (dev->n_erased_blocks < 1) {
 362                 /* Hoosterman we've got a problem.
 363                  * Can't get space to gc
 364                  */
 365                 yaffs_trace(YAFFS_TRACE_ERROR,
 366                   "yaffs tragedy: no more erased blocks");
 367
 368                 return -1;
 369         }
 370
 371         /* Find an empty block. */
 372
 373         for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
 374                 dev->alloc_block_finder++;
 375                 if (dev->alloc_block_finder < dev->internal_start_block
 376                     || dev->alloc_block_finder > dev->internal_end_block) {
 377                         dev->alloc_block_finder = dev->internal_start_block;
 378                 }
 379
 380                 bi = yaffs_get_block_info(dev, dev->alloc_block_finder);
 381
 382                 if (bi->block_state == YAFFS_BLOCK_STATE_EMPTY) {
 383                         bi->block_state = YAFFS_BLOCK_STATE_ALLOCATING;
 384                         dev->seq_number++;
 385                         bi->seq_number = dev->seq_number;
 386                         dev->n_erased_blocks--;
 387                         yaffs_trace(YAFFS_TRACE_ALLOCATE,
 388                           "Allocated block %d, seq  %d, %d left" ,
 389                            dev->alloc_block_finder, dev->seq_number,
 390                            dev->n_erased_blocks);
 391                         return dev->alloc_block_finder;
 392                 }
 393         }
 394
 395         yaffs_trace(YAFFS_TRACE_ALWAYS,
 396                 "yaffs tragedy: no more erased blocks, but there should have been %d",
 397                 dev->n_erased_blocks);
 398
 399         return -1;
 400 }
 401
 402 static int yaffs_alloc_chunk(struct yaffs_dev *dev, int use_reserver,
 403                              struct yaffs_block_info **block_ptr)
 404 {
 405         int ret_val;
 406         struct yaffs_block_info *bi;
 407
 408         if (dev->alloc_block < 0) {
 409                 /* Get next block to allocate off */
 410                 dev->alloc_block = yaffs_find_alloc_block(dev);
 411                 dev->alloc_page = 0;
 412         }
 413
 414         if (!use_reserver && !yaffs_check_alloc_available(dev, 1)) {
 415                 /* No space unless we're allowed to use the reserve. */
 416                 return -1;
 417         }
 418
 419         if (dev->n_erased_blocks < dev->param.n_reserved_blocks
 420             && dev->alloc_page == 0)
 421                 yaffs_trace(YAFFS_TRACE_ALLOCATE, "Allocating reserve");
 422
 423         /* Next page please.... */
 424         if (dev->alloc_block >= 0) {
 425                 bi = yaffs_get_block_info(dev, dev->alloc_block);
 426
 427                 ret_val = (dev->alloc_block * dev->param.chunks_per_block) +
 428                     dev->alloc_page;
 429                 bi->pages_in_use++;
 430                 yaffs_set_chunk_bit(dev, dev->alloc_block, dev->alloc_page);
 431
 432                 dev->alloc_page++;
 433
 434                 dev->n_free_chunks--;
 435
 436                 /* If the block is full set the state to full */
 437                 if (dev->alloc_page >= dev->param.chunks_per_block) {
 438                         bi->block_state = YAFFS_BLOCK_STATE_FULL;
 439                         dev->alloc_block = -1;
 440                 }
 441
 442                 if (block_ptr)
 443                         *block_ptr = bi;
 444
 445                 return ret_val;
 446         }
 447
 448         yaffs_trace(YAFFS_TRACE_ERROR,
 449                 "!!!!!!!!! Allocator out !!!!!!!!!!!!!!!!!");
 450
 451         return -1;
 452 }
 453
 454 static int yaffs_get_erased_chunks(struct yaffs_dev *dev)
 455 {
 456         int n;
 457
 458         n = dev->n_erased_blocks * dev->param.chunks_per_block;
 459
 460         if (dev->alloc_block > 0)
 461                 n += (dev->param.chunks_per_block - dev->alloc_page);
 462
 463         return n;
 464
 465 }
 466
 467 /*
 468  * yaffs_skip_rest_of_block() skips over the rest of the allocation block
 469  * if we don't want to write to it.
 470  */
 471 void yaffs_skip_rest_of_block(struct yaffs_dev *dev)
 472 {
 473         struct yaffs_block_info *bi;
 474
 475         if (dev->alloc_block > 0) {
 476                 bi = yaffs_get_block_info(dev, dev->alloc_block);
 477                 if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING) {
 478                         bi->block_state = YAFFS_BLOCK_STATE_FULL;
 479                         dev->alloc_block = -1;
 480                 }
 481         }
 482 }
 483
 484 static int yaffs_write_new_chunk(struct yaffs_dev *dev,
 485                                  const u8 *data,
 486                                  struct yaffs_ext_tags *tags, int use_reserver)
 487 {
 488         int attempts = 0;
 489         int write_ok = 0;
 490         int chunk;
 491
 492         yaffs2_checkpt_invalidate(dev);
 493
 494         do {
 495                 struct yaffs_block_info *bi = 0;
 496                 int erased_ok = 0;
 497
 498                 chunk = yaffs_alloc_chunk(dev, use_reserver, &bi);
 499                 if (chunk < 0) {
 500                         /* no space */
 501                         break;
 502                 }
 503
 504                 /* First check this chunk is erased, if it needs
 505                  * checking.  The checking policy (unless forced
 506                  * always on) is as follows:
 507                  *
 508                  * Check the first page we try to write in a block.
 509                  * If the check passes then we don't need to check any
 510                  * more.        If the check fails, we check again...
 511                  * If the block has been erased, we don't need to check.
 512                  *
 513                  * However, if the block has been prioritised for gc,
 514                  * then we think there might be something odd about
 515                  * this block and stop using it.
 516                  *
 517                  * Rationale: We should only ever see chunks that have
 518                  * not been erased if there was a partially written
 519                  * chunk due to power loss.  This checking policy should
 520                  * catch that case with very few checks and thus save a
 521                  * lot of checks that are most likely not needed.
 522                  *
 523                  * Mods to the above
 524                  * If an erase check fails or the write fails we skip the
 525                  * rest of the block.
 526                  */
 527
 528                 /* let's give it a try */
 529                 attempts++;
 530
 531                 if (dev->param.always_check_erased)
 532                         bi->skip_erased_check = 0;
 533
 534                 if (!bi->skip_erased_check) {
 535                         erased_ok = yaffs_check_chunk_erased(dev, chunk);
 536                         if (erased_ok != YAFFS_OK) {
 537                                 yaffs_trace(YAFFS_TRACE_ERROR,
 538                                   "**>> yaffs chunk %d was not erased",
 539                                   chunk);
 540
 541                                 /* If not erased, delete this one,
 542                                  * skip rest of block and
 543                                  * try another chunk */
 544                                 yaffs_chunk_del(dev, chunk, 1, __LINE__);
 545                                 yaffs_skip_rest_of_block(dev);
 546                                 continue;
 547                         }
 548                 }
 549
 550                 write_ok = yaffs_wr_chunk_tags_nand(dev, chunk, data, tags);
 551
 552                 if (!bi->skip_erased_check)
 553                         write_ok =
 554                             yaffs_verify_chunk_written(dev, chunk, data, tags);
 555
 556                 if (write_ok != YAFFS_OK) {
 557                         /* Clean up aborted write, skip to next block and
 558                          * try another chunk */
 559                         yaffs_handle_chunk_wr_error(dev, chunk, erased_ok);
 560                         continue;
 561                 }
 562
 563                 bi->skip_erased_check = 1;
 564
 565                 /* Copy the data into the robustification buffer */
 566                 yaffs_handle_chunk_wr_ok(dev, chunk, data, tags);
 567
 568         } while (write_ok != YAFFS_OK &&
 569                  (yaffs_wr_attempts <= 0 || attempts <= yaffs_wr_attempts));
 570
 571         if (!write_ok)
 572                 chunk = -1;
 573
 574         if (attempts > 1) {
 575                 yaffs_trace(YAFFS_TRACE_ERROR,
 576                         "**>> yaffs write required %d attempts",
 577                         attempts);
 578                 dev->n_retried_writes += (attempts - 1);
 579         }
 580
 581         return chunk;
 582 }
 583
 584 /*
 585  * Block retiring for handling a broken block.
 586  */
 587
 588 static void yaffs_retire_block(struct yaffs_dev *dev, int flash_block)
 589 {
 590         struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
 591
 592         yaffs2_checkpt_invalidate(dev);
 593
 594         yaffs2_clear_oldest_dirty_seq(dev, bi);
 595
 596         if (yaffs_mark_bad(dev, flash_block) != YAFFS_OK) {
 597                 if (yaffs_erase_block(dev, flash_block) != YAFFS_OK) {
 598                         yaffs_trace(YAFFS_TRACE_ALWAYS,
 599                                 "yaffs: Failed to mark bad and erase block %d",
 600                                 flash_block);
 601                 } else {
 602                         struct yaffs_ext_tags tags;
 603                         int chunk_id =
 604                             flash_block * dev->param.chunks_per_block;
 605
 606                         u8 *buffer = yaffs_get_temp_buffer(dev);
 607
 608                         memset(buffer, 0xff, dev->data_bytes_per_chunk);
 609                         memset(&tags, 0, sizeof(tags));
 610                         tags.seq_number = YAFFS_SEQUENCE_BAD_BLOCK;
 611                         if (dev->param.write_chunk_tags_fn(dev, chunk_id -
 612                                                            dev->chunk_offset,
 613                                                            buffer,
 614                                                            &tags) != YAFFS_OK)
 615                                 yaffs_trace(YAFFS_TRACE_ALWAYS,
 616                                         "yaffs: Failed to write bad block marker to block %d",
 617                                         flash_block);
 618
 619                         yaffs_release_temp_buffer(dev, buffer);
 620                 }
 621         }
 622
 623         bi->block_state = YAFFS_BLOCK_STATE_DEAD;
 624         bi->gc_prioritise = 0;
 625         bi->needs_retiring = 0;
 626
 627         dev->n_retired_blocks++;
 628 }
 629
 630 /*---------------- Name handling functions ------------*/
 631
 632 static u16 yaffs_calc_name_sum(const YCHAR *name)
 633 {
 634         u16 sum = 0;
 635         u16 i = 1;
 636
 637         if (!name)
 638                 return 0;
 639
 640         while ((*name) && i < (YAFFS_MAX_NAME_LENGTH / 2)) {
 641
 642                 /* 0x1f mask is case insensitive */
 643                 sum += ((*name) & 0x1f) * i;
 644                 i++;
 645                 name++;
 646         }
 647         return sum;
 648 }
 649
 650 void yaffs_set_obj_name(struct yaffs_obj *obj, const YCHAR * name)
 651 {
 652         memset(obj->short_name, 0, sizeof(obj->short_name));
 653         if (name &&
 654                 strnlen(name, YAFFS_SHORT_NAME_LENGTH + 1) <=
 655                 YAFFS_SHORT_NAME_LENGTH)
 656                 strcpy(obj->short_name, name);
 657         else
 658                 obj->short_name[0] = _Y('\0');
 659         obj->sum = yaffs_calc_name_sum(name);
 660 }
 661
 662 void yaffs_set_obj_name_from_oh(struct yaffs_obj *obj,
 663                                 const struct yaffs_obj_hdr *oh)
 664 {
 665 #ifdef CONFIG_YAFFS_AUTO_UNICODE
 666         YCHAR tmp_name[YAFFS_MAX_NAME_LENGTH + 1];
 667         memset(tmp_name, 0, sizeof(tmp_name));
 668         yaffs_load_name_from_oh(obj->my_dev, tmp_name, oh->name,
 669                                 YAFFS_MAX_NAME_LENGTH + 1);
 670         yaffs_set_obj_name(obj, tmp_name);
 671 #else
 672         yaffs_set_obj_name(obj, oh->name);
 673 #endif
 674 }
 675
 676 loff_t yaffs_max_file_size(struct yaffs_dev *dev)
 677 {
 678         return ((loff_t) YAFFS_MAX_CHUNK_ID) * dev->data_bytes_per_chunk;
 679 }
 680
 681 /*-------------------- TNODES -------------------
 682
 683  * List of spare tnodes
 684  * The list is hooked together using the first pointer
 685  * in the tnode.
 686  */
 687
 688 struct yaffs_tnode *yaffs_get_tnode(struct yaffs_dev *dev)
 689 {
 690         struct yaffs_tnode *tn = yaffs_alloc_raw_tnode(dev);
 691
 692         if (tn) {
 693                 memset(tn, 0, dev->tnode_size);
 694                 dev->n_tnodes++;
 695         }
 696
 697         dev->checkpoint_blocks_required = 0;    /* force recalculation */
 698
 699         return tn;
 700 }
 701
 702 /* FreeTnode frees up a tnode and puts it back on the free list */
 703 static void yaffs_free_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
 704 {
 705         yaffs_free_raw_tnode(dev, tn);
 706         dev->n_tnodes--;
 707         dev->checkpoint_blocks_required = 0;    /* force recalculation */
 708 }
 709
 710 static void yaffs_deinit_tnodes_and_objs(struct yaffs_dev *dev)
 711 {
 712         yaffs_deinit_raw_tnodes_and_objs(dev);
 713         dev->n_obj = 0;
 714         dev->n_tnodes = 0;
 715 }
 716
 717 static void yaffs_load_tnode_0(struct yaffs_dev *dev, struct yaffs_tnode *tn,
 718                         unsigned pos, unsigned val)
 719 {
 720         u32 *map = (u32 *) tn;
 721         u32 bit_in_map;
 722         u32 bit_in_word;
 723         u32 word_in_map;
 724         u32 mask;
 725
 726         pos &= YAFFS_TNODES_LEVEL0_MASK;
 727         val >>= dev->chunk_grp_bits;
 728
 729         bit_in_map = pos * dev->tnode_width;
 730         word_in_map = bit_in_map / 32;
 731         bit_in_word = bit_in_map & (32 - 1);
 732
 733         mask = dev->tnode_mask << bit_in_word;
 734
 735         map[word_in_map] &= ~mask;
 736         map[word_in_map] |= (mask & (val << bit_in_word));
 737
 738         if (dev->tnode_width > (32 - bit_in_word)) {
 739                 bit_in_word = (32 - bit_in_word);
 740                 word_in_map++;
 741                 mask =
 742                     dev->tnode_mask >> bit_in_word;
 743                 map[word_in_map] &= ~mask;
 744                 map[word_in_map] |= (mask & (val >> bit_in_word));
 745         }
 746 }
 747
 748 u32 yaffs_get_group_base(struct yaffs_dev *dev, struct yaffs_tnode *tn,
 749                          unsigned pos)
 750 {
 751         u32 *map = (u32 *) tn;
 752         u32 bit_in_map;
 753         u32 bit_in_word;
 754         u32 word_in_map;
 755         u32 val;
 756
 757         pos &= YAFFS_TNODES_LEVEL0_MASK;
 758
 759         bit_in_map = pos * dev->tnode_width;
 760         word_in_map = bit_in_map / 32;
 761         bit_in_word = bit_in_map & (32 - 1);
 762
 763         val = map[word_in_map] >> bit_in_word;
 764
 765         if (dev->tnode_width > (32 - bit_in_word)) {
 766                 bit_in_word = (32 - bit_in_word);
 767                 word_in_map++;
 768                 val |= (map[word_in_map] << bit_in_word);
 769         }
 770
 771         val &= dev->tnode_mask;
 772         val <<= dev->chunk_grp_bits;
 773
 774         return val;
 775 }
 776
 777 /* ------------------- End of individual tnode manipulation -----------------*/
 778
 779 /* ---------Functions to manipulate the look-up tree (made up of tnodes) ------
 780  * The look up tree is represented by the top tnode and the number of top_level
 781  * in the tree. 0 means only the level 0 tnode is in the tree.
 782  */
 783
 784 /* FindLevel0Tnode finds the level 0 tnode, if one exists. */
 785 struct yaffs_tnode *yaffs_find_tnode_0(struct yaffs_dev *dev,
 786                                        struct yaffs_file_var *file_struct,
 787                                        u32 chunk_id)
 788 {
 789         struct yaffs_tnode *tn = file_struct->top;
 790         u32 i;
 791         int required_depth;
 792         int level = file_struct->top_level;
 793
 794         (void) dev;
 795
 796         /* Check sane level and chunk Id */
 797         if (level < 0 || level > YAFFS_TNODES_MAX_LEVEL)
 798                 return NULL;
 799
 800         if (chunk_id > YAFFS_MAX_CHUNK_ID)
 801                 return NULL;
 802
 803         /* First check we're tall enough (ie enough top_level) */
 804
 805         i = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
 806         required_depth = 0;
 807         while (i) {
 808                 i >>= YAFFS_TNODES_INTERNAL_BITS;
 809                 required_depth++;
 810         }
 811
 812         if (required_depth > file_struct->top_level)
 813                 return NULL;    /* Not tall enough, so we can't find it */
 814
 815         /* Traverse down to level 0 */
 816         while (level > 0 && tn) {
 817                 tn = tn->internal[(chunk_id >>
 818                                    (YAFFS_TNODES_LEVEL0_BITS +
 819                                     (level - 1) *
 820                                     YAFFS_TNODES_INTERNAL_BITS)) &
 821                                   YAFFS_TNODES_INTERNAL_MASK];
 822                 level--;
 823         }
 824
 825         return tn;
 826 }
 827
 828 /* add_find_tnode_0 finds the level 0 tnode if it exists,
 829  * otherwise first expands the tree.
 830  * This happens in two steps:
 831  *  1. If the tree isn't tall enough, then make it taller.
 832  *  2. Scan down the tree towards the level 0 tnode adding tnodes if required.
 833  *
 834  * Used when modifying the tree.
 835  *
 836  *  If the tn argument is NULL, then a fresh tnode will be added otherwise the
 837  *  specified tn will be plugged into the ttree.
 838  */
 839
 840 struct yaffs_tnode *yaffs_add_find_tnode_0(struct yaffs_dev *dev,
 841                                            struct yaffs_file_var *file_struct,
 842                                            u32 chunk_id,
 843                                            struct yaffs_tnode *passed_tn)
 844 {
 845         int required_depth;
 846         int i;
 847         int l;
 848         struct yaffs_tnode *tn;
 849         u32 x;
 850
 851         /* Check sane level and page Id */
 852         if (file_struct->top_level < 0 ||
 853             file_struct->top_level > YAFFS_TNODES_MAX_LEVEL)
 854                 return NULL;
 855
 856         if (chunk_id > YAFFS_MAX_CHUNK_ID)
 857                 return NULL;
 858
 859         /* First check we're tall enough (ie enough top_level) */
 860
 861         x = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
 862         required_depth = 0;
 863         while (x) {
 864                 x >>= YAFFS_TNODES_INTERNAL_BITS;
 865                 required_depth++;
 866         }
 867
 868         if (required_depth > file_struct->top_level) {
 869                 /* Not tall enough, gotta make the tree taller */
 870                 for (i = file_struct->top_level; i < required_depth; i++) {
 871
 872                         tn = yaffs_get_tnode(dev);
 873
 874                         if (tn) {
 875                                 tn->internal[0] = file_struct->top;
 876                                 file_struct->top = tn;
 877                                 file_struct->top_level++;
 878                         } else {
 879                                 yaffs_trace(YAFFS_TRACE_ERROR,
 880                                         "yaffs: no more tnodes");
 881                                 return NULL;
 882                         }
 883                 }
 884         }
 885
 886         /* Traverse down to level 0, adding anything we need */
 887
 888         l = file_struct->top_level;
 889         tn = file_struct->top;
 890
 891         if (l > 0) {
 892                 while (l > 0 && tn) {
 893                         x = (chunk_id >>
 894                              (YAFFS_TNODES_LEVEL0_BITS +
 895                               (l - 1) * YAFFS_TNODES_INTERNAL_BITS)) &
 896                             YAFFS_TNODES_INTERNAL_MASK;
 897
 898                         if ((l > 1) && !tn->internal[x]) {
 899                                 /* Add missing non-level-zero tnode */
 900                                 tn->internal[x] = yaffs_get_tnode(dev);
 901                                 if (!tn->internal[x])
 902                                         return NULL;
 903                         } else if (l == 1) {
 904                                 /* Looking from level 1 at level 0 */
 905                                 if (passed_tn) {
 906                                         /* If we already have one, release it */
 907                                         if (tn->internal[x])
 908                                                 yaffs_free_tnode(dev,
 909                                                         tn->internal[x]);
 910                                         tn->internal[x] = passed_tn;
 911
 912                                 } else if (!tn->internal[x]) {
 913                                         /* Don't have one, none passed in */
 914                                         tn->internal[x] = yaffs_get_tnode(dev);
 915                                         if (!tn->internal[x])
 916                                                 return NULL;
 917                                 }
 918                         }
 919
 920                         tn = tn->internal[x];
 921                         l--;
 922                 }
 923         } else {
 924                 /* top is level 0 */
 925                 if (passed_tn) {
 926                         memcpy(tn, passed_tn,
 927                                (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8);
 928                         yaffs_free_tnode(dev, passed_tn);
 929                 }
 930         }
 931
 932         return tn;
 933 }
 934
 935 static int yaffs_tags_match(const struct yaffs_ext_tags *tags, int obj_id,
 936                             int chunk_obj)
 937 {
 938         return (tags->chunk_id == chunk_obj &&
 939                 tags->obj_id == obj_id &&
 940                 !tags->is_deleted) ? 1 : 0;
 941
 942 }
 943
 944 static int yaffs_find_chunk_in_group(struct yaffs_dev *dev, int the_chunk,
 945                                         struct yaffs_ext_tags *tags, int obj_id,
 946                                         int inode_chunk)
 947 {
 948         int j;
 949
 950         for (j = 0; the_chunk && j < dev->chunk_grp_size; j++) {
 951                 if (yaffs_check_chunk_bit
 952                     (dev, the_chunk / dev->param.chunks_per_block,
 953                      the_chunk % dev->param.chunks_per_block)) {
 954
 955                         if (dev->chunk_grp_size == 1)
 956                                 return the_chunk;
 957                         else {
 958                                 yaffs_rd_chunk_tags_nand(dev, the_chunk, NULL,
 959                                                          tags);
 960                                 if (yaffs_tags_match(tags,
 961                                                         obj_id, inode_chunk)) {
 962                                         /* found it; */
 963                                         return the_chunk;
 964                                 }
 965                         }
 966                 }
 967                 the_chunk++;
 968         }
 969         return -1;
 970 }
 971
 972 static int yaffs_find_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
 973                                     struct yaffs_ext_tags *tags)
 974 {
 975         /*Get the Tnode, then get the level 0 offset chunk offset */
 976         struct yaffs_tnode *tn;
 977         int the_chunk = -1;
 978         struct yaffs_ext_tags local_tags;
 979         int ret_val = -1;
 980         struct yaffs_dev *dev = in->my_dev;
 981
 982         if (!tags) {
 983                 /* Passed a NULL, so use our own tags space */
 984                 tags = &local_tags;
 985         }
 986
 987         tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
 988
 989         if (!tn)
 990                 return ret_val;
 991
 992         the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
 993
 994         ret_val = yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
 995                                               inode_chunk);
 996         return ret_val;
 997 }
 998
 999 static int yaffs_find_del_file_chunk(struct yaffs_obj *in, int inode_chunk,
1000                                      struct yaffs_ext_tags *tags)
1001 {
1002         /* Get the Tnode, then get the level 0 offset chunk offset */
1003         struct yaffs_tnode *tn;
1004         int the_chunk = -1;
1005         struct yaffs_ext_tags local_tags;
1006         struct yaffs_dev *dev = in->my_dev;
1007         int ret_val = -1;
1008
1009         if (!tags) {
1010                 /* Passed a NULL, so use our own tags space */
1011                 tags = &local_tags;
1012         }
1013
1014         tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
1015
1016         if (!tn)
1017                 return ret_val;
1018
1019         the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
1020
1021         ret_val = yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
1022                                               inode_chunk);
1023
1024         /* Delete the entry in the filestructure (if found) */
1025         if (ret_val != -1)
1026                 yaffs_load_tnode_0(dev, tn, inode_chunk, 0);
1027
1028         return ret_val;
1029 }
1030
1031 int yaffs_put_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
1032                             int nand_chunk, int in_scan)
1033 {
1034         /* NB in_scan is zero unless scanning.
1035          * For forward scanning, in_scan is > 0;
1036          * for backward scanning in_scan is < 0
1037          *
1038          * nand_chunk = 0 is a dummy insert to make sure the tnodes are there.
1039          */
1040
1041         struct yaffs_tnode *tn;
1042         struct yaffs_dev *dev = in->my_dev;
1043         int existing_cunk;
1044         struct yaffs_ext_tags existing_tags;
1045         struct yaffs_ext_tags new_tags;
1046         unsigned existing_serial, new_serial;
1047
1048         if (in->variant_type != YAFFS_OBJECT_TYPE_FILE) {
1049                 /* Just ignore an attempt at putting a chunk into a non-file
1050                  * during scanning.
1051                  * If it is not during Scanning then something went wrong!
1052                  */
1053                 if (!in_scan) {
1054                         yaffs_trace(YAFFS_TRACE_ERROR,
1055                                 "yaffs tragedy:attempt to put data chunk into a non-file"
1056                                 );
1057                         BUG();
1058                 }
1059
1060                 yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
1061                 return YAFFS_OK;
1062         }
1063
1064         tn = yaffs_add_find_tnode_0(dev,
1065                                     &in->variant.file_variant,
1066                                     inode_chunk, NULL);
1067         if (!tn)
1068                 return YAFFS_FAIL;
1069
1070         if (!nand_chunk)
1071                 /* Dummy insert, bail now */
1072                 return YAFFS_OK;
1073
1074         existing_cunk = yaffs_get_group_base(dev, tn, inode_chunk);
1075
1076         if (in_scan != 0) {
1077                 /* If we're scanning then we need to test for duplicates
1078                  * NB This does not need to be efficient since it should only
1079                  * happen when the power fails during a write, then only one
1080                  * chunk should ever be affected.
1081                  *
1082                  * Correction for YAFFS2: This could happen quite a lot and we
1083                  * need to think about efficiency! TODO
1084                  * Update: For backward scanning we don't need to re-read tags
1085                  * so this is quite cheap.
1086                  */
1087
1088                 if (existing_cunk > 0) {
1089                         /* NB Right now existing chunk will not be real
1090                          * chunk_id if the chunk group size > 1
1091                          * thus we have to do a FindChunkInFile to get the
1092                          * real chunk id.
1093                          *
1094                          * We have a duplicate now we need to decide which
1095                          * one to use:
1096                          *
1097                          * Backwards scanning YAFFS2: The old one is what
1098                          * we use, dump the new one.
1099                          * YAFFS1: Get both sets of tags and compare serial
1100                          * numbers.
1101                          */
1102
1103                         if (in_scan > 0) {
1104                                 /* Only do this for forward scanning */
1105                                 yaffs_rd_chunk_tags_nand(dev,
1106                                                          nand_chunk,
1107                                                          NULL, &new_tags);
1108
1109                                 /* Do a proper find */
1110                                 existing_cunk =
1111                                     yaffs_find_chunk_in_file(in, inode_chunk,
1112                                                              &existing_tags);
1113                         }
1114
1115                         if (existing_cunk <= 0) {
1116                                 /*Hoosterman - how did this happen? */
1117
1118                                 yaffs_trace(YAFFS_TRACE_ERROR,
1119                                         "yaffs tragedy: existing chunk < 0 in scan"
1120                                         );
1121
1122                         }
1123
1124                         /* NB The deleted flags should be false, otherwise
1125                          * the chunks will not be loaded during a scan
1126                          */
1127
1128                         if (in_scan > 0) {
1129                                 new_serial = new_tags.serial_number;
1130                                 existing_serial = existing_tags.serial_number;
1131                         }
1132
1133                         if ((in_scan > 0) &&
1134                             (existing_cunk <= 0 ||
1135                              ((existing_serial + 1) & 3) == new_serial)) {
1136                                 /* Forward scanning.
1137                                  * Use new
1138                                  * Delete the old one and drop through to
1139                                  * update the tnode
1140                                  */
1141                                 yaffs_chunk_del(dev, existing_cunk, 1,
1142                                                 __LINE__);
1143                         } else {
1144                                 /* Backward scanning or we want to use the
1145                                  * existing one
1146                                  * Delete the new one and return early so that
1147                                  * the tnode isn't changed
1148                                  */
1149                                 yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
1150                                 return YAFFS_OK;
1151                         }
1152                 }
1153
1154         }
1155
1156         if (existing_cunk == 0)
1157                 in->n_data_chunks++;
1158
1159         yaffs_load_tnode_0(dev, tn, inode_chunk, nand_chunk);
1160
1161         return YAFFS_OK;
1162 }
1163
1164 static void yaffs_soft_del_chunk(struct yaffs_dev *dev, int chunk)
1165 {
1166         struct yaffs_block_info *the_block;
1167         unsigned block_no;
1168
1169         yaffs_trace(YAFFS_TRACE_DELETION, "soft delete chunk %d", chunk);
1170
1171         block_no = chunk / dev->param.chunks_per_block;
1172         the_block = yaffs_get_block_info(dev, block_no);
1173         if (the_block) {
1174                 the_block->soft_del_pages++;
1175                 dev->n_free_chunks++;
1176                 yaffs2_update_oldest_dirty_seq(dev, block_no, the_block);
1177         }
1178 }
1179
1180 /* SoftDeleteWorker scans backwards through the tnode tree and soft deletes all
1181  * the chunks in the file.
1182  * All soft deleting does is increment the block's softdelete count and pulls
1183  * the chunk out of the tnode.
1184  * Thus, essentially this is the same as DeleteWorker except that the chunks
1185  * are soft deleted.
1186  */
1187
1188 static int yaffs_soft_del_worker(struct yaffs_obj *in, struct yaffs_tnode *tn,
1189                                  u32 level, int chunk_offset)
1190 {
1191         int i;
1192         int the_chunk;
1193         int all_done = 1;
1194         struct yaffs_dev *dev = in->my_dev;
1195
1196         if (!tn)
1197                 return 1;
1198
1199         if (level > 0) {
1200                 for (i = YAFFS_NTNODES_INTERNAL - 1;
1201                         all_done && i >= 0;
1202                         i--) {
1203                         if (tn->internal[i]) {
1204                                 all_done =
1205                                     yaffs_soft_del_worker(in,
1206                                         tn->internal[i],
1207                                         level - 1,
1208                                         (chunk_offset <<
1209                                         YAFFS_TNODES_INTERNAL_BITS)
1210                                         + i);
1211                                 if (all_done) {
1212                                         yaffs_free_tnode(dev,
1213                                                 tn->internal[i]);
1214                                         tn->internal[i] = NULL;
1215                                 } else {
1216                                         /* Can this happen? */
1217                                 }
1218                         }
1219                 }
1220                 return (all_done) ? 1 : 0;
1221         }
1222
1223         /* level 0 */
1224          for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0; i--) {
1225                 the_chunk = yaffs_get_group_base(dev, tn, i);
1226                 if (the_chunk) {
1227                         yaffs_soft_del_chunk(dev, the_chunk);
1228                         yaffs_load_tnode_0(dev, tn, i, 0);
1229                 }
1230         }
1231         return 1;
1232 }
1233
1234 static void yaffs_remove_obj_from_dir(struct yaffs_obj *obj)
1235 {
1236         struct yaffs_dev *dev = obj->my_dev;
1237         struct yaffs_obj *parent;
1238
1239         yaffs_verify_obj_in_dir(obj);
1240         parent = obj->parent;
1241
1242         yaffs_verify_dir(parent);
1243
1244         if (dev && dev->param.remove_obj_fn)
1245                 dev->param.remove_obj_fn(obj);
1246
1247         list_del_init(&obj->siblings);
1248         obj->parent = NULL;
1249
1250         yaffs_verify_dir(parent);
1251 }
1252
1253 void yaffs_add_obj_to_dir(struct yaffs_obj *directory, struct yaffs_obj *obj)
1254 {
1255         if (!directory) {
1256                 yaffs_trace(YAFFS_TRACE_ALWAYS,
1257                         "tragedy: Trying to add an object to a null pointer directory"
1258                         );
1259                 BUG();
1260                 return;
1261         }
1262         if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
1263                 yaffs_trace(YAFFS_TRACE_ALWAYS,
1264                         "tragedy: Trying to add an object to a non-directory"
1265                         );
1266                 BUG();
1267         }
1268
1269         if (obj->siblings.prev == NULL) {
1270                 /* Not initialised */
1271                 BUG();
1272         }
1273
1274         yaffs_verify_dir(directory);
1275
1276         yaffs_remove_obj_from_dir(obj);
1277
1278         /* Now add it */
1279         list_add(&obj->siblings, &directory->variant.dir_variant.children);
1280         obj->parent = directory;
1281
1282         if (directory == obj->my_dev->unlinked_dir
1283             || directory == obj->my_dev->del_dir) {
1284                 obj->unlinked = 1;
1285                 obj->my_dev->n_unlinked_files++;
1286                 obj->rename_allowed = 0;
1287         }
1288
1289         yaffs_verify_dir(directory);
1290         yaffs_verify_obj_in_dir(obj);
1291 }
1292
1293 static int yaffs_change_obj_name(struct yaffs_obj *obj,
1294                                  struct yaffs_obj *new_dir,
1295                                  const YCHAR *new_name, int force, int shadows)
1296 {
1297         int unlink_op;
1298         int del_op;
1299         struct yaffs_obj *existing_target;
1300
1301         if (new_dir == NULL)
1302                 new_dir = obj->parent;  /* use the old directory */
1303
1304         if (new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
1305                 yaffs_trace(YAFFS_TRACE_ALWAYS,
1306                         "tragedy: yaffs_change_obj_name: new_dir is not a directory"
1307                         );
1308                 BUG();
1309         }
1310
1311         unlink_op = (new_dir == obj->my_dev->unlinked_dir);
1312         del_op = (new_dir == obj->my_dev->del_dir);
1313
1314         existing_target = yaffs_find_by_name(new_dir, new_name);
1315
1316         /* If the object is a file going into the unlinked directory,
1317          *   then it is OK to just stuff it in since duplicate names are OK.
1318          *   else only proceed if the new name does not exist and we're putting
1319          *   it into a directory.
1320          */
1321         if (!(unlink_op || del_op || force ||
1322               shadows > 0 || !existing_target) ||
1323               new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
1324                 return YAFFS_FAIL;
1325
1326         yaffs_set_obj_name(obj, new_name);
1327         obj->dirty = 1;
1328         yaffs_add_obj_to_dir(new_dir, obj);
1329
1330         if (unlink_op)
1331                 obj->unlinked = 1;
1332
1333         /* If it is a deletion then we mark it as a shrink for gc  */
1334         if (yaffs_update_oh(obj, new_name, 0, del_op, shadows, NULL) >= 0)
1335                 return YAFFS_OK;
1336
1337         return YAFFS_FAIL;
1338 }
1339
1340 /*------------------------ Short Operations Cache ------------------------------
1341  *   In many situations where there is no high level buffering  a lot of
1342  *   reads might be short sequential reads, and a lot of writes may be short
1343  *   sequential writes. eg. scanning/writing a jpeg file.
1344  *   In these cases, a short read/write cache can provide a huge perfomance
1345  *   benefit with dumb-as-a-rock code.
1346  *   In Linux, the page cache provides read buffering and the short op cache
1347  *   provides write buffering.
1348  *
1349  *   There are a small number (~10) of cache chunks per device so that we don't
1350  *   need a very intelligent search.
1351  */
1352
1353 static int yaffs_obj_cache_dirty(struct yaffs_obj *obj)
1354 {
1355         struct yaffs_dev *dev = obj->my_dev;
1356         int i;
1357         struct yaffs_cache *cache;
1358         int n_caches = obj->my_dev->param.n_caches;
1359
1360         for (i = 0; i < n_caches; i++) {
1361                 cache = &dev->cache[i];
1362                 if (cache->object == obj && cache->dirty)
1363                         return 1;
1364         }
1365
1366         return 0;
1367 }
1368
1369 static void yaffs_flush_file_cache(struct yaffs_obj *obj)
1370 {
1371         struct yaffs_dev *dev = obj->my_dev;
1372         int lowest = -99;       /* Stop compiler whining. */
1373         int i;
1374         struct yaffs_cache *cache;
1375         int chunk_written = 0;
1376         int n_caches = obj->my_dev->param.n_caches;
1377
1378         if (n_caches < 1)
1379                 return;
1380         do {
1381                 cache = NULL;
1382
1383                 /* Find the lowest dirty chunk for this object */
1384                 for (i = 0; i < n_caches; i++) {
1385                         if (dev->cache[i].object == obj &&
1386                             dev->cache[i].dirty) {
1387                                 if (!cache ||
1388                                     dev->cache[i].chunk_id < lowest) {
1389                                         cache = &dev->cache[i];
1390                                         lowest = cache->chunk_id;
1391                                 }
1392                         }
1393                 }
1394
1395                 if (cache && !cache->locked) {
1396                         /* Write it out and free it up */
1397                         chunk_written =
1398                             yaffs_wr_data_obj(cache->object,
1399                                               cache->chunk_id,
1400                                               cache->data,
1401                                               cache->n_bytes, 1);
1402                         cache->dirty = 0;
1403                         cache->object = NULL;
1404                 }
1405         } while (cache && chunk_written > 0);
1406
1407         if (cache)
1408                 /* Hoosterman, disk full while writing cache out. */
1409                 yaffs_trace(YAFFS_TRACE_ERROR,
1410                         "yaffs tragedy: no space during cache write");
1411 }
1412
1413 /*yaffs_flush_whole_cache(dev)
1414  *
1415  *
1416  */
1417
1418 void yaffs_flush_whole_cache(struct yaffs_dev *dev)
1419 {
1420         struct yaffs_obj *obj;
1421         int n_caches = dev->param.n_caches;
1422         int i;
1423
1424         /* Find a dirty object in the cache and flush it...
1425          * until there are no further dirty objects.
1426          */
1427         do {
1428                 obj = NULL;
1429                 for (i = 0; i < n_caches && !obj; i++) {
1430                         if (dev->cache[i].object && dev->cache[i].dirty)
1431                                 obj = dev->cache[i].object;
1432                 }
1433                 if (obj)
1434                         yaffs_flush_file_cache(obj);
1435         } while (obj);
1436
1437 }
1438
1439 /* Grab us a cache chunk for use.
1440  * First look for an empty one.
1441  * Then look for the least recently used non-dirty one.
1442  * Then look for the least recently used dirty one...., flush and look again.
1443  */
1444 static struct yaffs_cache *yaffs_grab_chunk_worker(struct yaffs_dev *dev)
1445 {
1446         int i;
1447
1448         if (dev->param.n_caches > 0) {
1449                 for (i = 0; i < dev->param.n_caches; i++) {
1450                         if (!dev->cache[i].object)
1451                                 return &dev->cache[i];
1452                 }
1453         }
1454         return NULL;
1455 }
1456
1457 static struct yaffs_cache *yaffs_grab_chunk_cache(struct yaffs_dev *dev)
1458 {
1459         struct yaffs_cache *cache;
1460         struct yaffs_obj *the_obj;
1461         int usage;
1462         int i;
1463         int pushout;
1464
1465         if (dev->param.n_caches < 1)
1466                 return NULL;
1467
1468         /* Try find a non-dirty one... */
1469
1470         cache = yaffs_grab_chunk_worker(dev);
1471
1472         if (!cache) {
1473                 /* They were all dirty, find the LRU object and flush
1474                  * its cache, then  find again.
1475                  * NB what's here is not very accurate,
1476                  * we actually flush the object with the LRU chunk.
1477                  */
1478
1479                 /* With locking we can't assume we can use entry zero,
1480                  * Set the_obj to a valid pointer for Coverity. */
1481                 the_obj = dev->cache[0].object;
1482                 usage = -1;
1483                 cache = NULL;
1484                 pushout = -1;
1485
1486                 for (i = 0; i < dev->param.n_caches; i++) {
1487                         if (dev->cache[i].object &&
1488                             !dev->cache[i].locked &&
1489                             (dev->cache[i].last_use < usage ||
1490                             !cache)) {
1491                                 usage = dev->cache[i].last_use;
1492                                 the_obj = dev->cache[i].object;
1493                                 cache = &dev->cache[i];
1494                                 pushout = i;
1495                         }
1496                 }
1497
1498                 if (!cache || cache->dirty) {
1499                         /* Flush and try again */
1500                         yaffs_flush_file_cache(the_obj);
1501                         cache = yaffs_grab_chunk_worker(dev);
1502                 }
1503         }
1504         return cache;
1505 }
1506
1507 /* Find a cached chunk */
1508 static struct yaffs_cache *yaffs_find_chunk_cache(const struct yaffs_obj *obj,
1509                                                   int chunk_id)
1510 {
1511         struct yaffs_dev *dev = obj->my_dev;
1512         int i;
1513
1514         if (dev->param.n_caches < 1)
1515                 return NULL;
1516
1517         for (i = 0; i < dev->param.n_caches; i++) {
1518                 if (dev->cache[i].object == obj &&
1519                     dev->cache[i].chunk_id == chunk_id) {
1520                         dev->cache_hits++;
1521
1522                         return &dev->cache[i];
1523                 }
1524         }
1525         return NULL;
1526 }
1527
1528 /* Mark the chunk for the least recently used algorithym */
1529 static void yaffs_use_cache(struct yaffs_dev *dev, struct yaffs_cache *cache,
1530                             int is_write)
1531 {
1532         int i;
1533
1534         if (dev->param.n_caches < 1)
1535                 return;
1536
1537         if (dev->cache_last_use < 0 ||
1538                 dev->cache_last_use > 100000000) {
1539                 /* Reset the cache usages */
1540                 for (i = 1; i < dev->param.n_caches; i++)
1541                         dev->cache[i].last_use = 0;
1542
1543                 dev->cache_last_use = 0;
1544         }
1545         dev->cache_last_use++;
1546         cache->last_use = dev->cache_last_use;
1547
1548         if (is_write)
1549                 cache->dirty = 1;
1550 }
1551
1552 /* Invalidate a single cache page.
1553  * Do this when a whole page gets written,
1554  * ie the short cache for this page is no longer valid.
1555  */
1556 static void yaffs_invalidate_chunk_cache(struct yaffs_obj *object, int chunk_id)
1557 {
1558         struct yaffs_cache *cache;
1559
1560         if (object->my_dev->param.n_caches > 0) {
1561                 cache = yaffs_find_chunk_cache(object, chunk_id);
1562
1563                 if (cache)
1564                         cache->object = NULL;
1565         }
1566 }
1567
1568 /* Invalidate all the cache pages associated with this object
1569  * Do this whenever ther file is deleted or resized.
1570  */
1571 static void yaffs_invalidate_whole_cache(struct yaffs_obj *in)
1572 {
1573         int i;
1574         struct yaffs_dev *dev = in->my_dev;
1575
1576         if (dev->param.n_caches > 0) {
1577                 /* Invalidate it. */
1578                 for (i = 0; i < dev->param.n_caches; i++) {
1579                         if (dev->cache[i].object == in)
1580                                 dev->cache[i].object = NULL;
1581                 }
1582         }
1583 }
1584
1585 static void yaffs_unhash_obj(struct yaffs_obj *obj)
1586 {
1587         int bucket;
1588         struct yaffs_dev *dev = obj->my_dev;
1589
1590         /* If it is still linked into the bucket list, free from the list */
1591         if (!list_empty(&obj->hash_link)) {
1592                 list_del_init(&obj->hash_link);
1593                 bucket = yaffs_hash_fn(obj->obj_id);
1594                 dev->obj_bucket[bucket].count--;
1595         }
1596 }
1597
1598 /*  FreeObject frees up a Object and puts it back on the free list */
1599 static void yaffs_free_obj(struct yaffs_obj *obj)
1600 {
1601         struct yaffs_dev *dev;
1602
1603         if (!obj) {
1604                 BUG();
1605                 return;
1606         }
1607         dev = obj->my_dev;
1608         yaffs_trace(YAFFS_TRACE_OS, "FreeObject %p inode %p",
1609                 obj, obj->my_inode);
1610         if (obj->parent)
1611                 BUG();
1612         if (!list_empty(&obj->siblings))
1613                 BUG();
1614
1615         if (obj->my_inode) {
1616                 /* We're still hooked up to a cached inode.
1617                  * Don't delete now, but mark for later deletion
1618                  */
1619                 obj->defered_free = 1;
1620                 return;
1621         }
1622
1623         yaffs_unhash_obj(obj);
1624
1625         yaffs_free_raw_obj(dev, obj);
1626         dev->n_obj--;
1627         dev->checkpoint_blocks_required = 0;    /* force recalculation */
1628 }
1629
1630 void yaffs_handle_defered_free(struct yaffs_obj *obj)
1631 {
1632         if (obj->defered_free)
1633                 yaffs_free_obj(obj);
1634 }
1635
1636 static int yaffs_generic_obj_del(struct yaffs_obj *in)
1637 {
1638         /* Iinvalidate the file's data in the cache, without flushing. */
1639         yaffs_invalidate_whole_cache(in);
1640
1641         if (in->my_dev->param.is_yaffs2 && in->parent != in->my_dev->del_dir) {
1642                 /* Move to unlinked directory so we have a deletion record */
1643                 yaffs_change_obj_name(in, in->my_dev->del_dir, _Y("deleted"), 0,
1644                                       0);
1645         }
1646
1647         yaffs_remove_obj_from_dir(in);
1648         yaffs_chunk_del(in->my_dev, in->hdr_chunk, 1, __LINE__);
1649         in->hdr_chunk = 0;
1650
1651         yaffs_free_obj(in);
1652         return YAFFS_OK;
1653
1654 }
1655
1656 static void yaffs_soft_del_file(struct yaffs_obj *obj)
1657 {
1658         if (!obj->deleted ||
1659             obj->variant_type != YAFFS_OBJECT_TYPE_FILE ||
1660             obj->soft_del)
1661                 return;
1662
1663         if (obj->n_data_chunks <= 0) {
1664                 /* Empty file with no duplicate object headers,
1665                  * just delete it immediately */
1666                 yaffs_free_tnode(obj->my_dev, obj->variant.file_variant.top);
1667                 obj->variant.file_variant.top = NULL;
1668                 yaffs_trace(YAFFS_TRACE_TRACING,
1669                         "yaffs: Deleting empty file %d",
1670                         obj->obj_id);
1671                 yaffs_generic_obj_del(obj);
1672         } else {
1673                 yaffs_soft_del_worker(obj,
1674                                       obj->variant.file_variant.top,
1675                                       obj->variant.
1676                                       file_variant.top_level, 0);
1677                 obj->soft_del = 1;
1678         }
1679 }
1680
1681 /* Pruning removes any part of the file structure tree that is beyond the
1682  * bounds of the file (ie that does not point to chunks).
1683  *
1684  * A file should only get pruned when its size is reduced.
1685  *
1686  * Before pruning, the chunks must be pulled from the tree and the
1687  * level 0 tnode entries must be zeroed out.
1688  * Could also use this for file deletion, but that's probably better handled
1689  * by a special case.
1690  *
1691  * This function is recursive. For levels > 0 the function is called again on
1692  * any sub-tree. For level == 0 we just check if the sub-tree has data.
1693  * If there is no data in a subtree then it is pruned.
1694  */
1695
1696 static struct yaffs_tnode *yaffs_prune_worker(struct yaffs_dev *dev,
1697                                               struct yaffs_tnode *tn, u32 level,
1698                                               int del0)
1699 {
1700         int i;
1701         int has_data;
1702
1703         if (!tn)
1704                 return tn;
1705
1706         has_data = 0;
1707
1708         if (level > 0) {
1709                 for (i = 0; i < YAFFS_NTNODES_INTERNAL; i++) {
1710                         if (tn->internal[i]) {
1711                                 tn->internal[i] =
1712                                     yaffs_prune_worker(dev,
1713                                                 tn->internal[i],
1714                                                 level - 1,
1715                                                 (i == 0) ? del0 : 1);
1716                         }
1717
1718                         if (tn->internal[i])
1719                                 has_data++;
1720                 }
1721         } else {
1722                 int tnode_size_u32 = dev->tnode_size / sizeof(u32);
1723                 u32 *map = (u32 *) tn;
1724
1725                 for (i = 0; !has_data && i < tnode_size_u32; i++) {
1726                         if (map[i])
1727                                 has_data++;
1728                 }
1729         }
1730
1731         if (has_data == 0 && del0) {
1732                 /* Free and return NULL */
1733                 yaffs_free_tnode(dev, tn);
1734                 tn = NULL;
1735         }
1736         return tn;
1737 }
1738
1739 static int yaffs_prune_tree(struct yaffs_dev *dev,
1740                             struct yaffs_file_var *file_struct)
1741 {
1742         int i;
1743         int has_data;
1744         int done = 0;
1745         struct yaffs_tnode *tn;
1746
1747         if (file_struct->top_level < 1)
1748                 return YAFFS_OK;
1749
1750         file_struct->top =
1751            yaffs_prune_worker(dev, file_struct->top, file_struct->top_level, 0);
1752
1753         /* Now we have a tree with all the non-zero branches NULL but
1754          * the height is the same as it was.
1755          * Let's see if we can trim internal tnodes to shorten the tree.
1756          * We can do this if only the 0th element in the tnode is in use
1757          * (ie all the non-zero are NULL)
1758          */
1759
1760         while (file_struct->top_level && !done) {
1761                 tn = file_struct->top;
1762
1763                 has_data = 0;
1764                 for (i = 1; i < YAFFS_NTNODES_INTERNAL; i++) {
1765                         if (tn->internal[i])
1766                                 has_data++;
1767                 }
1768
1769                 if (!has_data) {
1770                         file_struct->top = tn->internal[0];
1771                         file_struct->top_level--;
1772                         yaffs_free_tnode(dev, tn);
1773                 } else {
1774                         done = 1;
1775                 }
1776         }
1777
1778         return YAFFS_OK;
1779 }
1780
1781 /*-------------------- End of File Structure functions.-------------------*/
1782
1783 /* alloc_empty_obj gets us a clean Object.*/
1784 static struct yaffs_obj *yaffs_alloc_empty_obj(struct yaffs_dev *dev)
1785 {
1786         struct yaffs_obj *obj = yaffs_alloc_raw_obj(dev);
1787
1788         if (!obj)
1789                 return obj;
1790
1791         dev->n_obj++;
1792
1793         /* Now sweeten it up... */
1794
1795         memset(obj, 0, sizeof(struct yaffs_obj));
1796         obj->being_created = 1;
1797
1798         obj->my_dev = dev;
1799         obj->hdr_chunk = 0;
1800         obj->variant_type = YAFFS_OBJECT_TYPE_UNKNOWN;
1801         INIT_LIST_HEAD(&(obj->hard_links));
1802         INIT_LIST_HEAD(&(obj->hash_link));
1803         INIT_LIST_HEAD(&obj->siblings);
1804
1805         /* Now make the directory sane */
1806         if (dev->root_dir) {
1807                 obj->parent = dev->root_dir;
1808                 list_add(&(obj->siblings),
1809                          &dev->root_dir->variant.dir_variant.children);
1810         }
1811
1812         /* Add it to the lost and found directory.
1813          * NB Can't put root or lost-n-found in lost-n-found so
1814          * check if lost-n-found exists first
1815          */
1816         if (dev->lost_n_found)
1817                 yaffs_add_obj_to_dir(dev->lost_n_found, obj);
1818
1819         obj->being_created = 0;
1820
1821         dev->checkpoint_blocks_required = 0;    /* force recalculation */
1822
1823         return obj;
1824 }
1825
1826 static int yaffs_find_nice_bucket(struct yaffs_dev *dev)
1827 {
1828         int i;
1829         int l = 999;
1830         int lowest = 999999;
1831
1832         /* Search for the shortest list or one that
1833          * isn't too long.
1834          */
1835
1836         for (i = 0; i < 10 && lowest > 4; i++) {
1837                 dev->bucket_finder++;
1838                 dev->bucket_finder %= YAFFS_NOBJECT_BUCKETS;
1839                 if (dev->obj_bucket[dev->bucket_finder].count < lowest) {
1840                         lowest = dev->obj_bucket[dev->bucket_finder].count;
1841                         l = dev->bucket_finder;
1842                 }
1843         }
1844
1845         return l;
1846 }
1847
1848 static int yaffs_new_obj_id(struct yaffs_dev *dev)
1849 {
1850         int bucket = yaffs_find_nice_bucket(dev);
1851         int found = 0;
1852         struct list_head *i;
1853         u32 n = (u32) bucket;
1854
1855         /* Now find an object value that has not already been taken
1856          * by scanning the list.
1857          */
1858
1859         while (!found) {
1860                 found = 1;
1861                 n += YAFFS_NOBJECT_BUCKETS;
1862                 if (1 || dev->obj_bucket[bucket].count > 0) {
1863                         list_for_each(i, &dev->obj_bucket[bucket].list) {
1864                                 /* If there is already one in the list */
1865                                 if (i && list_entry(i, struct yaffs_obj,
1866                                                     hash_link)->obj_id == n) {
1867                                         found = 0;
1868                                 }
1869                         }
1870                 }
1871         }
1872         return n;
1873 }
1874
1875 static void yaffs_hash_obj(struct yaffs_obj *in)
1876 {
1877         int bucket = yaffs_hash_fn(in->obj_id);
1878         struct yaffs_dev *dev = in->my_dev;
1879
1880         list_add(&in->hash_link, &dev->obj_bucket[bucket].list);
1881         dev->obj_bucket[bucket].count++;
1882 }
1883
1884 struct yaffs_obj *yaffs_find_by_number(struct yaffs_dev *dev, u32 number)
1885 {
1886         int bucket = yaffs_hash_fn(number);
1887         struct list_head *i;
1888         struct yaffs_obj *in;
1889
1890         list_for_each(i, &dev->obj_bucket[bucket].list) {
1891                 /* Look if it is in the list */
1892                 in = list_entry(i, struct yaffs_obj, hash_link);
1893                 if (in->obj_id == number) {
1894                         /* Don't show if it is defered free */
1895                         if (in->defered_free)
1896                                 return NULL;
1897                         return in;
1898                 }
1899         }
1900
1901         return NULL;
1902 }
1903
1904 static struct yaffs_obj *yaffs_new_obj(struct yaffs_dev *dev, int number,
1905                                 enum yaffs_obj_type type)
1906 {
1907         struct yaffs_obj *the_obj = NULL;
1908         struct yaffs_tnode *tn = NULL;
1909
1910         if (number < 0)
1911                 number = yaffs_new_obj_id(dev);
1912
1913         if (type == YAFFS_OBJECT_TYPE_FILE) {
1914                 tn = yaffs_get_tnode(dev);
1915                 if (!tn)
1916                         return NULL;
1917         }
1918
1919         the_obj = yaffs_alloc_empty_obj(dev);
1920         if (!the_obj) {
1921                 if (tn)
1922                         yaffs_free_tnode(dev, tn);
1923                 return NULL;
1924         }
1925
1926         the_obj->fake = 0;
1927         the_obj->rename_allowed = 1;
1928         the_obj->unlink_allowed = 1;
1929         the_obj->obj_id = number;
1930         yaffs_hash_obj(the_obj);
1931         the_obj->variant_type = type;
1932         yaffs_load_current_time(the_obj, 1, 1);
1933
1934         switch (type) {
1935         case YAFFS_OBJECT_TYPE_FILE:
1936                 the_obj->variant.file_variant.file_size = 0;
1937                 the_obj->variant.file_variant.scanned_size = 0;
1938                 the_obj->variant.file_variant.shrink_size =
1939                                                 yaffs_max_file_size(dev);
1940                 the_obj->variant.file_variant.top_level = 0;
1941                 the_obj->variant.file_variant.top = tn;
1942                 break;
1943         case YAFFS_OBJECT_TYPE_DIRECTORY:
1944                 INIT_LIST_HEAD(&the_obj->variant.dir_variant.children);
1945                 INIT_LIST_HEAD(&the_obj->variant.dir_variant.dirty);
1946                 break;
1947         case YAFFS_OBJECT_TYPE_SYMLINK:
1948         case YAFFS_OBJECT_TYPE_HARDLINK:
1949         case YAFFS_OBJECT_TYPE_SPECIAL:
1950                 /* No action required */
1951                 break;
1952         case YAFFS_OBJECT_TYPE_UNKNOWN:
1953                 /* todo this should not happen */
1954                 break;
1955         }
1956         return the_obj;
1957 }
1958
1959 static struct yaffs_obj *yaffs_create_fake_dir(struct yaffs_dev *dev,
1960                                                int number, u32 mode)
1961 {
1962
1963         struct yaffs_obj *obj =
1964             yaffs_new_obj(dev, number, YAFFS_OBJECT_TYPE_DIRECTORY);
1965
1966         if (!obj)
1967                 return NULL;
1968
1969         obj->fake = 1;  /* it is fake so it might not use NAND */
1970         obj->rename_allowed = 0;
1971         obj->unlink_allowed = 0;
1972         obj->deleted = 0;
1973         obj->unlinked = 0;
1974         obj->yst_mode = mode;
1975         obj->my_dev = dev;
1976         obj->hdr_chunk = 0;     /* Not a valid chunk. */
1977         return obj;
1978
1979 }
1980
1981
1982 static void yaffs_init_tnodes_and_objs(struct yaffs_dev *dev)
1983 {
1984         int i;
1985
1986         dev->n_obj = 0;
1987         dev->n_tnodes = 0;
1988         yaffs_init_raw_tnodes_and_objs(dev);
1989
1990         for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
1991                 INIT_LIST_HEAD(&dev->obj_bucket[i].list);
1992                 dev->obj_bucket[i].count = 0;
1993         }
1994 }
1995
1996 struct yaffs_obj *yaffs_find_or_create_by_number(struct yaffs_dev *dev,
1997                                                  int number,
1998                                                  enum yaffs_obj_type type)
1999 {
2000         struct yaffs_obj *the_obj = NULL;
2001
2002         if (number > 0)
2003                 the_obj = yaffs_find_by_number(dev, number);
2004
2005         if (!the_obj)
2006                 the_obj = yaffs_new_obj(dev, number, type);
2007
2008         return the_obj;
2009
2010 }
2011
2012 YCHAR *yaffs_clone_str(const YCHAR *str)
2013 {
2014         YCHAR *new_str = NULL;
2015         int len;
2016
2017         if (!str)
2018                 str = _Y("");
2019
2020         len = strnlen(str, YAFFS_MAX_ALIAS_LENGTH);
2021         new_str = kmalloc((len + 1) * sizeof(YCHAR), GFP_NOFS);
2022         if (new_str) {
2023                 strncpy(new_str, str, len);
2024                 new_str[len] = 0;
2025         }
2026         return new_str;
2027
2028 }
2029 /*
2030  *yaffs_update_parent() handles fixing a directories mtime and ctime when a new
2031  * link (ie. name) is created or deleted in the directory.
2032  *
2033  * ie.
2034  *   create dir/a : update dir's mtime/ctime
2035  *   rm dir/a:   update dir's mtime/ctime
2036  *   modify dir/a: don't update dir's mtimme/ctime
2037  *
2038  * This can be handled immediately or defered. Defering helps reduce the number
2039  * of updates when many files in a directory are changed within a brief period.
2040  *
2041  * If the directory updating is defered then yaffs_update_dirty_dirs must be
2042  * called periodically.
2043  */
2044
2045 static void yaffs_update_parent(struct yaffs_obj *obj)
2046 {
2047         struct yaffs_dev *dev;
2048
2049         if (!obj)
2050                 return;
2051         dev = obj->my_dev;
2052         obj->dirty = 1;
2053         yaffs_load_current_time(obj, 0, 1);
2054         if (dev->param.defered_dir_update) {
2055                 struct list_head *link = &obj->variant.dir_variant.dirty;
2056
2057                 if (list_empty(link)) {
2058                         list_add(link, &dev->dirty_dirs);
2059                         yaffs_trace(YAFFS_TRACE_BACKGROUND,
2060                           "Added object %d to dirty directories",
2061                            obj->obj_id);
2062                 }
2063
2064         } else {
2065                 yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
2066         }
2067 }
2068
2069 void yaffs_update_dirty_dirs(struct yaffs_dev *dev)
2070 {
2071         struct list_head *link;
2072         struct yaffs_obj *obj;
2073         struct yaffs_dir_var *d_s;
2074         union yaffs_obj_var *o_v;
2075
2076         yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update dirty directories");
2077
2078         while (!list_empty(&dev->dirty_dirs)) {
2079                 link = dev->dirty_dirs.next;
2080                 list_del_init(link);
2081
2082                 d_s = list_entry(link, struct yaffs_dir_var, dirty);
2083                 o_v = list_entry(d_s, union yaffs_obj_var, dir_variant);
2084                 obj = list_entry(o_v, struct yaffs_obj, variant);
2085
2086                 yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update directory %d",
2087                         obj->obj_id);
2088
2089                 if (obj->dirty)
2090                         yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
2091         }
2092 }
2093
2094 /*
2095  * Mknod (create) a new object.
2096  * equiv_obj only has meaning for a hard link;
2097  * alias_str only has meaning for a symlink.
2098  * rdev only has meaning for devices (a subset of special objects)
2099  */
2100
2101 static struct yaffs_obj *yaffs_create_obj(enum yaffs_obj_type type,
2102                                           struct yaffs_obj *parent,
2103                                           const YCHAR *name,
2104                                           u32 mode,
2105                                           u32 uid,
2106                                           u32 gid,
2107                                           struct yaffs_obj *equiv_obj,
2108                                           const YCHAR *alias_str, u32 rdev)
2109 {
2110         struct yaffs_obj *in;
2111         YCHAR *str = NULL;
2112         struct yaffs_dev *dev = parent->my_dev;
2113
2114         /* Check if the entry exists.
2115          * If it does then fail the call since we don't want a dup. */
2116         if (yaffs_find_by_name(parent, name))
2117                 return NULL;
2118
2119         if (type == YAFFS_OBJECT_TYPE_SYMLINK) {
2120                 str = yaffs_clone_str(alias_str);
2121                 if (!str)
2122                         return NULL;
2123         }
2124
2125         in = yaffs_new_obj(dev, -1, type);
2126
2127         if (!in) {
2128                 kfree(str);
2129                 return NULL;
2130         }
2131
2132         in->hdr_chunk = 0;
2133         in->valid = 1;
2134         in->variant_type = type;
2135
2136         in->yst_mode = mode;
2137
2138         yaffs_attribs_init(in, gid, uid, rdev);
2139
2140         in->n_data_chunks = 0;
2141
2142         yaffs_set_obj_name(in, name);
2143         in->dirty = 1;
2144
2145         yaffs_add_obj_to_dir(parent, in);
2146
2147         in->my_dev = parent->my_dev;
2148
2149         switch (type) {
2150         case YAFFS_OBJECT_TYPE_SYMLINK:
2151                 in->variant.symlink_variant.alias = str;
2152                 break;
2153         case YAFFS_OBJECT_TYPE_HARDLINK:
2154                 in->variant.hardlink_variant.equiv_obj = equiv_obj;
2155                 in->variant.hardlink_variant.equiv_id = equiv_obj->obj_id;
2156                 list_add(&in->hard_links, &equiv_obj->hard_links);
2157                 break;
2158         case YAFFS_OBJECT_TYPE_FILE:
2159         case YAFFS_OBJECT_TYPE_DIRECTORY:
2160         case YAFFS_OBJECT_TYPE_SPECIAL:
2161         case YAFFS_OBJECT_TYPE_UNKNOWN:
2162                 /* do nothing */
2163                 break;
2164         }
2165
2166         if (yaffs_update_oh(in, name, 0, 0, 0, NULL) < 0) {
2167                 /* Could not create the object header, fail */
2168                 yaffs_del_obj(in);
2169                 in = NULL;
2170         }
2171
2172         if (in)
2173                 yaffs_update_parent(parent);
2174
2175         return in;
2176 }
2177
2178 struct yaffs_obj *yaffs_create_file(struct yaffs_obj *parent,
2179                                     const YCHAR *name, u32 mode, u32 uid,
2180                                     u32 gid)
2181 {
2182         return yaffs_create_obj(YAFFS_OBJECT_TYPE_FILE, parent, name, mode,
2183                                 uid, gid, NULL, NULL, 0);
2184 }
2185
2186 struct yaffs_obj *yaffs_create_dir(struct yaffs_obj *parent, const YCHAR *name,
2187                                    u32 mode, u32 uid, u32 gid)
2188 {
2189         return yaffs_create_obj(YAFFS_OBJECT_TYPE_DIRECTORY, parent, name,
2190                                 mode, uid, gid, NULL, NULL, 0);
2191 }
2192
2193 struct yaffs_obj *yaffs_create_special(struct yaffs_obj *parent,
2194                                        const YCHAR *name, u32 mode, u32 uid,
2195                                        u32 gid, u32 rdev)
2196 {
2197         return yaffs_create_obj(YAFFS_OBJECT_TYPE_SPECIAL, parent, name, mode,
2198                                 uid, gid, NULL, NULL, rdev);
2199 }
2200
2201 struct yaffs_obj *yaffs_create_symlink(struct yaffs_obj *parent,
2202                                        const YCHAR *name, u32 mode, u32 uid,
2203                                        u32 gid, const YCHAR *alias)
2204 {
2205         return yaffs_create_obj(YAFFS_OBJECT_TYPE_SYMLINK, parent, name, mode,
2206                                 uid, gid, NULL, alias, 0);
2207 }
2208
2209 /* yaffs_link_obj returns the object id of the equivalent object.*/
2210 struct yaffs_obj *yaffs_link_obj(struct yaffs_obj *parent, const YCHAR * name,
2211                                  struct yaffs_obj *equiv_obj)
2212 {
2213         /* Get the real object in case we were fed a hard link obj */
2214         equiv_obj = yaffs_get_equivalent_obj(equiv_obj);
2215
2216         if (yaffs_create_obj(YAFFS_OBJECT_TYPE_HARDLINK,
2217                         parent, name, 0, 0, 0,
2218                         equiv_obj, NULL, 0))
2219                 return equiv_obj;
2220
2221         return NULL;
2222
2223 }
2224
2225
2226
2227 /*---------------------- Block Management and Page Allocation -------------*/
2228
2229 static void yaffs_deinit_blocks(struct yaffs_dev *dev)
2230 {
2231         if (dev->block_info_alt && dev->block_info)
2232                 vfree(dev->block_info);
2233         else
2234                 kfree(dev->block_info);
2235
2236         dev->block_info_alt = 0;
2237
2238         dev->block_info = NULL;
2239
2240         if (dev->chunk_bits_alt && dev->chunk_bits)
2241                 vfree(dev->chunk_bits);
2242         else
2243                 kfree(dev->chunk_bits);
2244         dev->chunk_bits_alt = 0;
2245         dev->chunk_bits = NULL;
2246 }
2247
2248 static int yaffs_init_blocks(struct yaffs_dev *dev)
2249 {
2250         int n_blocks = dev->internal_end_block - dev->internal_start_block + 1;
2251
2252         dev->block_info = NULL;
2253         dev->chunk_bits = NULL;
2254         dev->alloc_block = -1;  /* force it to get a new one */
2255
2256         /* If the first allocation strategy fails, thry the alternate one */
2257         dev->block_info =
2258                 kmalloc(n_blocks * sizeof(struct yaffs_block_info), GFP_NOFS);
2259         if (!dev->block_info) {
2260                 dev->block_info =
2261                     vmalloc(n_blocks * sizeof(struct yaffs_block_info));
2262                 dev->block_info_alt = 1;
2263         } else {
2264                 dev->block_info_alt = 0;
2265         }
2266
2267         if (!dev->block_info)
2268                 goto alloc_error;
2269
2270         /* Set up dynamic blockinfo stuff. Round up bytes. */
2271         dev->chunk_bit_stride = (dev->param.chunks_per_block + 7) / 8;
2272         dev->chunk_bits =
2273                 kmalloc(dev->chunk_bit_stride * n_blocks, GFP_NOFS);
2274         if (!dev->chunk_bits) {
2275                 dev->chunk_bits =
2276                     vmalloc(dev->chunk_bit_stride * n_blocks);
2277                 dev->chunk_bits_alt = 1;
2278         } else {
2279                 dev->chunk_bits_alt = 0;
2280         }
2281         if (!dev->chunk_bits)
2282                 goto alloc_error;
2283
2284
2285         memset(dev->block_info, 0, n_blocks * sizeof(struct yaffs_block_info));
2286         memset(dev->chunk_bits, 0, dev->chunk_bit_stride * n_blocks);
2287         return YAFFS_OK;
2288
2289 alloc_error:
2290         yaffs_deinit_blocks(dev);
2291         return YAFFS_FAIL;
2292 }
2293
2294
2295 void yaffs_block_became_dirty(struct yaffs_dev *dev, int block_no)
2296 {
2297         struct yaffs_block_info *bi = yaffs_get_block_info(dev, block_no);
2298         int erased_ok = 0;
2299         int i;
2300
2301         /* If the block is still healthy erase it and mark as clean.
2302          * If the block has had a data failure, then retire it.
2303          */
2304
2305         yaffs_trace(YAFFS_TRACE_GC | YAFFS_TRACE_ERASE,
2306                 "yaffs_block_became_dirty block %d state %d %s",
2307                 block_no, bi->block_state,
2308                 (bi->needs_retiring) ? "needs retiring" : "");
2309
2310         yaffs2_clear_oldest_dirty_seq(dev, bi);
2311
2312         bi->block_state = YAFFS_BLOCK_STATE_DIRTY;
2313
2314         /* If this is the block being garbage collected then stop gc'ing */
2315         if (block_no == dev->gc_block)
2316                 dev->gc_block = 0;
2317
2318         /* If this block is currently the best candidate for gc
2319          * then drop as a candidate */
2320         if (block_no == dev->gc_dirtiest) {
2321                 dev->gc_dirtiest = 0;
2322                 dev->gc_pages_in_use = 0;
2323         }
2324
2325         if (!bi->needs_retiring) {
2326                 yaffs2_checkpt_invalidate(dev);
2327                 erased_ok = yaffs_erase_block(dev, block_no);
2328                 if (!erased_ok) {
2329                         dev->n_erase_failures++;
2330                         yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2331                           "**>> Erasure failed %d", block_no);
2332                 }
2333         }
2334
2335         /* Verify erasure if needed */
2336         if (erased_ok &&
2337             ((yaffs_trace_mask & YAFFS_TRACE_ERASE) ||
2338              !yaffs_skip_verification(dev))) {
2339                 for (i = 0; i < dev->param.chunks_per_block; i++) {
2340                         if (!yaffs_check_chunk_erased(dev,
2341                                 block_no * dev->param.chunks_per_block + i)) {
2342                                 yaffs_trace(YAFFS_TRACE_ERROR,
2343                                         ">>Block %d erasure supposedly OK, but chunk %d not erased",
2344                                         block_no, i);
2345                         }
2346                 }
2347         }
2348
2349         if (!erased_ok) {
2350                 /* We lost a block of free space */
2351                 dev->n_free_chunks -= dev->param.chunks_per_block;
2352                 yaffs_retire_block(dev, block_no);
2353                 yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2354                         "**>> Block %d retired", block_no);
2355                 return;
2356         }
2357
2358         /* Clean it up... */
2359         bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
2360         bi->seq_number = 0;
2361         dev->n_erased_blocks++;
2362         bi->pages_in_use = 0;
2363         bi->soft_del_pages = 0;
2364         bi->has_shrink_hdr = 0;
2365         bi->skip_erased_check = 1;      /* Clean, so no need to check */
2366         bi->gc_prioritise = 0;
2367         bi->has_summary = 0;
2368
2369         yaffs_clear_chunk_bits(dev, block_no);
2370
2371         yaffs_trace(YAFFS_TRACE_ERASE, "Erased block %d", block_no);
2372 }
2373
2374 static inline int yaffs_gc_process_chunk(struct yaffs_dev *dev,
2375                                         struct yaffs_block_info *bi,
2376                                         int old_chunk, u8 *buffer)
2377 {
2378         int new_chunk;
2379         int mark_flash = 1;
2380         struct yaffs_ext_tags tags;
2381         struct yaffs_obj *object;
2382         int matching_chunk;
2383         int ret_val = YAFFS_OK;
2384
2385         memset(&tags, 0, sizeof(tags));
2386         yaffs_rd_chunk_tags_nand(dev, old_chunk,
2387                                  buffer, &tags);
2388         object = yaffs_find_by_number(dev, tags.obj_id);
2389
2390         yaffs_trace(YAFFS_TRACE_GC_DETAIL,
2391                 "Collecting chunk in block %d, %d %d %d ",
2392                 dev->gc_chunk, tags.obj_id,
2393                 tags.chunk_id, tags.n_bytes);
2394
2395         if (object && !yaffs_skip_verification(dev)) {
2396                 if (tags.chunk_id == 0)
2397                         matching_chunk =
2398                             object->hdr_chunk;
2399                 else if (object->soft_del)
2400                         /* Defeat the test */
2401                         matching_chunk = old_chunk;
2402                 else
2403                         matching_chunk =
2404                             yaffs_find_chunk_in_file
2405                             (object, tags.chunk_id,
2406                              NULL);
2407
2408                 if (old_chunk != matching_chunk)
2409                         yaffs_trace(YAFFS_TRACE_ERROR,
2410                                 "gc: page in gc mismatch: %d %d %d %d",
2411                                 old_chunk,
2412                                 matching_chunk,
2413                                 tags.obj_id,
2414                                 tags.chunk_id);
2415         }
2416
2417         if (!object) {
2418                 yaffs_trace(YAFFS_TRACE_ERROR,
2419                         "page %d in gc has no object: %d %d %d ",
2420                         old_chunk,
2421                         tags.obj_id, tags.chunk_id,
2422                         tags.n_bytes);
2423         }
2424
2425         if (object &&
2426             object->deleted &&
2427             object->soft_del && tags.chunk_id != 0) {
2428                 /* Data chunk in a soft deleted file,
2429                  * throw it away.
2430                  * It's a soft deleted data chunk,
2431                  * No need to copy this, just forget
2432                  * about it and fix up the object.
2433                  */
2434
2435                 /* Free chunks already includes
2436                  * softdeleted chunks, how ever this
2437                  * chunk is going to soon be really
2438                  * deleted which will increment free
2439                  * chunks. We have to decrement free
2440                  * chunks so this works out properly.
2441                  */
2442                 dev->n_free_chunks--;
2443                 bi->soft_del_pages--;
2444
2445                 object->n_data_chunks--;
2446                 if (object->n_data_chunks <= 0) {
2447                         /* remeber to clean up obj */
2448                         dev->gc_cleanup_list[dev->n_clean_ups] = tags.obj_id;
2449                         dev->n_clean_ups++;
2450                 }
2451                 mark_flash = 0;
2452         } else if (object) {
2453                 /* It's either a data chunk in a live
2454                  * file or an ObjectHeader, so we're
2455                  * interested in it.
2456                  * NB Need to keep the ObjectHeaders of
2457                  * deleted files until the whole file
2458                  * has been deleted off
2459                  */
2460                 tags.serial_number++;
2461                 dev->n_gc_copies++;
2462
2463                 if (tags.chunk_id == 0) {
2464                         /* It is an object Id,
2465                          * We need to nuke the
2466                          * shrinkheader flags since its
2467                          * work is done.
2468                          * Also need to clean up
2469                          * shadowing.
2470                          */
2471                         struct yaffs_obj_hdr *oh;
2472                         oh = (struct yaffs_obj_hdr *) buffer;
2473
2474                         oh->is_shrink = 0;
2475                         tags.extra_is_shrink = 0;
2476                         oh->shadows_obj = 0;
2477                         oh->inband_shadowed_obj_id = 0;
2478                         tags.extra_shadows = 0;
2479
2480                         /* Update file size */
2481                         if (object->variant_type == YAFFS_OBJECT_TYPE_FILE) {
2482                                 yaffs_oh_size_load(oh,
2483                                     object->variant.file_variant.file_size);
2484                                 tags.extra_file_size =
2485                                     object->variant.file_variant.file_size;
2486                         }
2487
2488                         yaffs_verify_oh(object, oh, &tags, 1);
2489                         new_chunk =
2490                             yaffs_write_new_chunk(dev, (u8 *) oh, &tags, 1);
2491                 } else {
2492                         new_chunk =
2493                             yaffs_write_new_chunk(dev, buffer, &tags, 1);
2494                 }
2495
2496                 if (new_chunk < 0) {
2497                         ret_val = YAFFS_FAIL;
2498                 } else {
2499
2500                         /* Now fix up the Tnodes etc. */
2501
2502                         if (tags.chunk_id == 0) {
2503                                 /* It's a header */
2504                                 object->hdr_chunk = new_chunk;
2505                                 object->serial = tags.serial_number;
2506                         } else {
2507                                 /* It's a data chunk */
2508                                 yaffs_put_chunk_in_file(object, tags.chunk_id,
2509                                                         new_chunk, 0);
2510                         }
2511                 }
2512         }
2513         if (ret_val == YAFFS_OK)
2514                 yaffs_chunk_del(dev, old_chunk, mark_flash, __LINE__);
2515         return ret_val;
2516 }
2517
2518 static int yaffs_gc_block(struct yaffs_dev *dev, int block, int whole_block)
2519 {
2520         int old_chunk;
2521         int ret_val = YAFFS_OK;
2522         int i;
2523         int is_checkpt_block;
2524         int max_copies;
2525         int chunks_before = yaffs_get_erased_chunks(dev);
2526         int chunks_after;
2527         struct yaffs_block_info *bi = yaffs_get_block_info(dev, block);
2528
2529         is_checkpt_block = (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT);
2530
2531         yaffs_trace(YAFFS_TRACE_TRACING,
2532                 "Collecting block %d, in use %d, shrink %d, whole_block %d",
2533                 block, bi->pages_in_use, bi->has_shrink_hdr,
2534                 whole_block);
2535
2536         /*yaffs_verify_free_chunks(dev); */
2537
2538         if (bi->block_state == YAFFS_BLOCK_STATE_FULL)
2539                 bi->block_state = YAFFS_BLOCK_STATE_COLLECTING;
2540
2541         bi->has_shrink_hdr = 0; /* clear the flag so that the block can erase */
2542
2543         dev->gc_disable = 1;
2544
2545         yaffs_summary_gc(dev, block);
2546
2547         if (is_checkpt_block || !yaffs_still_some_chunks(dev, block)) {
2548                 yaffs_trace(YAFFS_TRACE_TRACING,
2549                         "Collecting block %d that has no chunks in use",
2550                         block);
2551                 yaffs_block_became_dirty(dev, block);
2552         } else {
2553
2554                 u8 *buffer = yaffs_get_temp_buffer(dev);
2555
2556                 yaffs_verify_blk(dev, bi, block);
2557
2558                 max_copies = (whole_block) ? dev->param.chunks_per_block : 5;
2559                 old_chunk = block * dev->param.chunks_per_block + dev->gc_chunk;
2560
2561                 for (/* init already done */ ;
2562                      ret_val == YAFFS_OK &&
2563                      dev->gc_chunk < dev->param.chunks_per_block &&
2564                      (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) &&
2565                      max_copies > 0;
2566                      dev->gc_chunk++, old_chunk++) {
2567                         if (yaffs_check_chunk_bit(dev, block, dev->gc_chunk)) {
2568                                 /* Page is in use and might need to be copied */
2569                                 max_copies--;
2570                                 ret_val = yaffs_gc_process_chunk(dev, bi,
2571                                                         old_chunk, buffer);
2572                         }
2573                 }
2574                 yaffs_release_temp_buffer(dev, buffer);
2575         }
2576
2577         yaffs_verify_collected_blk(dev, bi, block);
2578
2579         if (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
2580                 /*
2581                  * The gc did not complete. Set block state back to FULL
2582                  * because checkpointing does not restore gc.
2583                  */
2584                 bi->block_state = YAFFS_BLOCK_STATE_FULL;
2585         } else {
2586                 /* The gc completed. */
2587                 /* Do any required cleanups */
2588                 for (i = 0; i < dev->n_clean_ups; i++) {
2589                         /* Time to delete the file too */
2590                         struct yaffs_obj *object =
2591                             yaffs_find_by_number(dev, dev->gc_cleanup_list[i]);
2592                         if (object) {
2593                                 yaffs_free_tnode(dev,
2594                                           object->variant.file_variant.top);
2595                                 object->variant.file_variant.top = NULL;
2596                                 yaffs_trace(YAFFS_TRACE_GC,
2597                                         "yaffs: About to finally delete object %d",
2598                                         object->obj_id);
2599                                 yaffs_generic_obj_del(object);
2600                                 object->my_dev->n_deleted_files--;
2601                         }
2602
2603                 }
2604                 chunks_after = yaffs_get_erased_chunks(dev);
2605                 if (chunks_before >= chunks_after)
2606                         yaffs_trace(YAFFS_TRACE_GC,
2607                                 "gc did not increase free chunks before %d after %d",
2608                                 chunks_before, chunks_after);
2609                 dev->gc_block = 0;
2610                 dev->gc_chunk = 0;
2611                 dev->n_clean_ups = 0;
2612         }
2613
2614         dev->gc_disable = 0;
2615
2616         return ret_val;
2617 }
2618
2619 /*
2620  * find_gc_block() selects the dirtiest block (or close enough)
2621  * for garbage collection.
2622  */
2623
2624 static unsigned yaffs_find_gc_block(struct yaffs_dev *dev,
2625                                     int aggressive, int background)
2626 {
2627         int i;
2628         int iterations;
2629         unsigned selected = 0;
2630         int prioritised = 0;
2631         int prioritised_exist = 0;
2632         struct yaffs_block_info *bi;
2633         int threshold;
2634
2635         /* First let's see if we need to grab a prioritised block */
2636         if (dev->has_pending_prioritised_gc && !aggressive) {
2637                 dev->gc_dirtiest = 0;
2638                 bi = dev->block_info;
2639                 for (i = dev->internal_start_block;
2640                      i <= dev->internal_end_block && !selected; i++) {
2641
2642                         if (bi->gc_prioritise) {
2643                                 prioritised_exist = 1;
2644                                 if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
2645                                     yaffs_block_ok_for_gc(dev, bi)) {
2646                                         selected = i;
2647                                         prioritised = 1;
2648                                 }
2649                         }
2650                         bi++;
2651                 }
2652
2653                 /*
2654                  * If there is a prioritised block and none was selected then
2655                  * this happened because there is at least one old dirty block
2656                  * gumming up the works. Let's gc the oldest dirty block.
2657                  */
2658
2659                 if (prioritised_exist &&
2660                     !selected && dev->oldest_dirty_block > 0)
2661                         selected = dev->oldest_dirty_block;
2662
2663                 if (!prioritised_exist) /* None found, so we can clear this */
2664                         dev->has_pending_prioritised_gc = 0;
2665         }
2666
2667         /* If we're doing aggressive GC then we are happy to take a less-dirty
2668          * block, and search harder.
2669          * else (leasurely gc), then we only bother to do this if the
2670          * block has only a few pages in use.
2671          */
2672
2673         if (!selected) {
2674                 int pages_used;
2675                 int n_blocks =
2676                     dev->internal_end_block - dev->internal_start_block + 1;
2677                 if (aggressive) {
2678                         threshold = dev->param.chunks_per_block;
2679                         iterations = n_blocks;
2680                 } else {
2681                         int max_threshold;
2682
2683                         if (background)
2684                                 max_threshold = dev->param.chunks_per_block / 2;
2685                         else
2686                                 max_threshold = dev->param.chunks_per_block / 8;
2687
2688                         if (max_threshold < YAFFS_GC_PASSIVE_THRESHOLD)
2689                                 max_threshold = YAFFS_GC_PASSIVE_THRESHOLD;
2690
2691                         threshold = background ? (dev->gc_not_done + 2) * 2 : 0;
2692                         if (threshold < YAFFS_GC_PASSIVE_THRESHOLD)
2693                                 threshold = YAFFS_GC_PASSIVE_THRESHOLD;
2694                         if (threshold > max_threshold)
2695                                 threshold = max_threshold;
2696
2697                         iterations = n_blocks / 16 + 1;
2698                         if (iterations > 100)
2699                                 iterations = 100;
2700                 }
2701
2702                 for (i = 0;
2703                      i < iterations &&
2704                      (dev->gc_dirtiest < 1 ||
2705                       dev->gc_pages_in_use > YAFFS_GC_GOOD_ENOUGH);
2706                      i++) {
2707                         dev->gc_block_finder++;
2708                         if (dev->gc_block_finder < dev->internal_start_block ||
2709                             dev->gc_block_finder > dev->internal_end_block)
2710                                 dev->gc_block_finder =
2711                                     dev->internal_start_block;
2712
2713                         bi = yaffs_get_block_info(dev, dev->gc_block_finder);
2714
2715                         pages_used = bi->pages_in_use - bi->soft_del_pages;
2716
2717                         if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
2718                             pages_used < dev->param.chunks_per_block &&
2719                             (dev->gc_dirtiest < 1 ||
2720                              pages_used < dev->gc_pages_in_use) &&
2721                             yaffs_block_ok_for_gc(dev, bi)) {
2722                                 dev->gc_dirtiest = dev->gc_block_finder;
2723                                 dev->gc_pages_in_use = pages_used;
2724                         }
2725                 }
2726
2727                 if (dev->gc_dirtiest > 0 && dev->gc_pages_in_use <= threshold)
2728                         selected = dev->gc_dirtiest;
2729         }
2730
2731         /*
2732          * If nothing has been selected for a while, try the oldest dirty
2733          * because that's gumming up the works.
2734          */
2735
2736         if (!selected && dev->param.is_yaffs2 &&
2737             dev->gc_not_done >= (background ? 10 : 20)) {
2738                 yaffs2_find_oldest_dirty_seq(dev);
2739                 if (dev->oldest_dirty_block > 0) {
2740                         selected = dev->oldest_dirty_block;
2741                         dev->gc_dirtiest = selected;
2742                         dev->oldest_dirty_gc_count++;
2743                         bi = yaffs_get_block_info(dev, selected);
2744                         dev->gc_pages_in_use =
2745                             bi->pages_in_use - bi->soft_del_pages;
2746                 } else {
2747                         dev->gc_not_done = 0;
2748                 }
2749         }
2750
2751         if (selected) {
2752                 yaffs_trace(YAFFS_TRACE_GC,
2753                         "GC Selected block %d with %d free, prioritised:%d",
2754                         selected,
2755                         dev->param.chunks_per_block - dev->gc_pages_in_use,
2756                         prioritised);
2757
2758                 dev->n_gc_blocks++;
2759                 if (background)
2760                         dev->bg_gcs++;
2761
2762                 dev->gc_dirtiest = 0;
2763                 dev->gc_pages_in_use = 0;
2764                 dev->gc_not_done = 0;
2765                 if (dev->refresh_skip > 0)
2766                         dev->refresh_skip--;
2767         } else {
2768                 dev->gc_not_done++;
2769                 yaffs_trace(YAFFS_TRACE_GC,
2770                         "GC none: finder %d skip %d threshold %d dirtiest %d using %d oldest %d%s",
2771                         dev->gc_block_finder, dev->gc_not_done, threshold,
2772                         dev->gc_dirtiest, dev->gc_pages_in_use,
2773                         dev->oldest_dirty_block, background ? " bg" : "");
2774         }
2775
2776         return selected;
2777 }
2778
2779 /* New garbage collector
2780  * If we're very low on erased blocks then we do aggressive garbage collection
2781  * otherwise we do "leasurely" garbage collection.
2782  * Aggressive gc looks further (whole array) and will accept less dirty blocks.
2783  * Passive gc only inspects smaller areas and only accepts more dirty blocks.
2784  *
2785  * The idea is to help clear out space in a more spread-out manner.
2786  * Dunno if it really does anything useful.
2787  */
2788 static int yaffs_check_gc(struct yaffs_dev *dev, int background)
2789 {
2790         int aggressive = 0;
2791         int gc_ok = YAFFS_OK;
2792         int max_tries = 0;
2793         int min_erased;
2794         int erased_chunks;
2795         int checkpt_block_adjust;
2796
2797         if (dev->param.gc_control && (dev->param.gc_control(dev) & 1) == 0)
2798                 return YAFFS_OK;
2799
2800         if (dev->gc_disable)
2801                 /* Bail out so we don't get recursive gc */
2802                 return YAFFS_OK;
2803
2804         /* This loop should pass the first time.
2805          * Only loops here if the collection does not increase space.
2806          */
2807
2808         do {
2809                 max_tries++;
2810
2811                 checkpt_block_adjust = yaffs_calc_checkpt_blocks_required(dev);
2812
2813                 min_erased =
2814                     dev->param.n_reserved_blocks + checkpt_block_adjust + 1;
2815                 erased_chunks =
2816                     dev->n_erased_blocks * dev->param.chunks_per_block;
2817
2818                 /* If we need a block soon then do aggressive gc. */
2819                 if (dev->n_erased_blocks < min_erased)
2820                         aggressive = 1;
2821                 else {
2822                         if (!background
2823                             && erased_chunks > (dev->n_free_chunks / 4))
2824                                 break;
2825
2826                         if (dev->gc_skip > 20)
2827                                 dev->gc_skip = 20;
2828                         if (erased_chunks < dev->n_free_chunks / 2 ||
2829                             dev->gc_skip < 1 || background)
2830                                 aggressive = 0;
2831                         else {
2832                                 dev->gc_skip--;
2833                                 break;
2834                         }
2835                 }
2836
2837                 dev->gc_skip = 5;
2838
2839                 /* If we don't already have a block being gc'd then see if we
2840                  * should start another */
2841
2842                 if (dev->gc_block < 1 && !aggressive) {
2843                         dev->gc_block = yaffs2_find_refresh_block(dev);
2844                         dev->gc_chunk = 0;
2845                         dev->n_clean_ups = 0;
2846                 }
2847                 if (dev->gc_block < 1) {
2848                         dev->gc_block =
2849                             yaffs_find_gc_block(dev, aggressive, background);
2850                         dev->gc_chunk = 0;
2851                         dev->n_clean_ups = 0;
2852                 }
2853
2854                 if (dev->gc_block > 0) {
2855                         dev->all_gcs++;
2856                         if (!aggressive)
2857                                 dev->passive_gc_count++;
2858
2859                         yaffs_trace(YAFFS_TRACE_GC,
2860                                 "yaffs: GC n_erased_blocks %d aggressive %d",
2861                                 dev->n_erased_blocks, aggressive);
2862
2863                         gc_ok = yaffs_gc_block(dev, dev->gc_block, aggressive);
2864                 }
2865
2866                 if (dev->n_erased_blocks < (dev->param.n_reserved_blocks) &&
2867                     dev->gc_block > 0) {
2868                         yaffs_trace(YAFFS_TRACE_GC,
2869                                 "yaffs: GC !!!no reclaim!!! n_erased_blocks %d after try %d block %d",
2870                                 dev->n_erased_blocks, max_tries,
2871                                 dev->gc_block);
2872                 }
2873         } while ((dev->n_erased_blocks < dev->param.n_reserved_blocks) &&
2874                  (dev->gc_block > 0) && (max_tries < 2));
2875
2876         return aggressive ? gc_ok : YAFFS_OK;
2877 }
2878
2879 /*
2880  * yaffs_bg_gc()
2881  * Garbage collects. Intended to be called from a background thread.
2882  * Returns non-zero if at least half the free chunks are erased.
2883  */
2884 int yaffs_bg_gc(struct yaffs_dev *dev, unsigned urgency)
2885 {
2886         int erased_chunks = dev->n_erased_blocks * dev->param.chunks_per_block;
2887
2888         yaffs_trace(YAFFS_TRACE_BACKGROUND, "Background gc %u", urgency);
2889
2890         yaffs_check_gc(dev, 1);
2891         return erased_chunks > dev->n_free_chunks / 2;
2892 }
2893
2894 /*-------------------- Data file manipulation -----------------*/
2895
2896 static int yaffs_rd_data_obj(struct yaffs_obj *in, int inode_chunk, u8 * buffer)
2897 {
2898         int nand_chunk = yaffs_find_chunk_in_file(in, inode_chunk, NULL);
2899
2900         if (nand_chunk >= 0)
2901                 return yaffs_rd_chunk_tags_nand(in->my_dev, nand_chunk,
2902                                                 buffer, NULL);
2903         else {
2904                 yaffs_trace(YAFFS_TRACE_NANDACCESS,
2905                         "Chunk %d not found zero instead",
2906                         nand_chunk);
2907                 /* get sane (zero) data if you read a hole */
2908                 memset(buffer, 0, in->my_dev->data_bytes_per_chunk);
2909                 return 0;
2910         }
2911
2912 }
2913
2914 void yaffs_chunk_del(struct yaffs_dev *dev, int chunk_id, int mark_flash,
2915                      int lyn)
2916 {
2917         int block;
2918         int page;
2919         struct yaffs_ext_tags tags;
2920         struct yaffs_block_info *bi;
2921
2922         if (chunk_id <= 0)
2923                 return;
2924
2925         dev->n_deletions++;
2926         block = chunk_id / dev->param.chunks_per_block;
2927         page = chunk_id % dev->param.chunks_per_block;
2928
2929         if (!yaffs_check_chunk_bit(dev, block, page))
2930                 yaffs_trace(YAFFS_TRACE_VERIFY,
2931                         "Deleting invalid chunk %d", chunk_id);
2932
2933         bi = yaffs_get_block_info(dev, block);
2934
2935         yaffs2_update_oldest_dirty_seq(dev, block, bi);
2936
2937         yaffs_trace(YAFFS_TRACE_DELETION,
2938                 "line %d delete of chunk %d",
2939                 lyn, chunk_id);
2940
2941         if (!dev->param.is_yaffs2 && mark_flash &&
2942             bi->block_state != YAFFS_BLOCK_STATE_COLLECTING) {
2943
2944                 memset(&tags, 0, sizeof(tags));
2945                 tags.is_deleted = 1;
2946                 yaffs_wr_chunk_tags_nand(dev, chunk_id, NULL, &tags);
2947                 yaffs_handle_chunk_update(dev, chunk_id, &tags);
2948         } else {
2949                 dev->n_unmarked_deletions++;
2950         }
2951
2952         /* Pull out of the management area.
2953          * If the whole block became dirty, this will kick off an erasure.
2954          */
2955         if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING ||
2956             bi->block_state == YAFFS_BLOCK_STATE_FULL ||
2957             bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCAN ||
2958             bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
2959                 dev->n_free_chunks++;
2960                 yaffs_clear_chunk_bit(dev, block, page);
2961                 bi->pages_in_use--;
2962
2963                 if (bi->pages_in_use == 0 &&
2964                     !bi->has_shrink_hdr &&
2965                     bi->block_state != YAFFS_BLOCK_STATE_ALLOCATING &&
2966                     bi->block_state != YAFFS_BLOCK_STATE_NEEDS_SCAN) {
2967                         yaffs_block_became_dirty(dev, block);
2968                 }
2969         }
2970 }
2971
2972 static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
2973                              const u8 *buffer, int n_bytes, int use_reserve)
2974 {
2975         /* Find old chunk Need to do this to get serial number
2976          * Write new one and patch into tree.
2977          * Invalidate old tags.
2978          */
2979
2980         int prev_chunk_id;
2981         struct yaffs_ext_tags prev_tags;
2982         int new_chunk_id;
2983         struct yaffs_ext_tags new_tags;
2984         struct yaffs_dev *dev = in->my_dev;
2985
2986         yaffs_check_gc(dev, 0);
2987
2988         /* Get the previous chunk at this location in the file if it exists.
2989          * If it does not exist then put a zero into the tree. This creates
2990          * the tnode now, rather than later when it is harder to clean up.
2991          */
2992         prev_chunk_id = yaffs_find_chunk_in_file(in, inode_chunk, &prev_tags);
2993         if (prev_chunk_id < 1 &&
2994             !yaffs_put_chunk_in_file(in, inode_chunk, 0, 0))
2995                 return 0;
2996
2997         /* Set up new tags */
2998         memset(&new_tags, 0, sizeof(new_tags));
2999
3000         new_tags.chunk_id = inode_chunk;
3001         new_tags.obj_id = in->obj_id;
3002         new_tags.serial_number =
3003             (prev_chunk_id > 0) ? prev_tags.serial_number + 1 : 1;
3004         new_tags.n_bytes = n_bytes;
3005
3006         if (n_bytes < 1 || n_bytes > dev->param.total_bytes_per_chunk) {
3007                 yaffs_trace(YAFFS_TRACE_ERROR,
3008                   "Writing %d bytes to chunk!!!!!!!!!",
3009                    n_bytes);
3010                 BUG();
3011         }
3012
3013         new_chunk_id =
3014             yaffs_write_new_chunk(dev, buffer, &new_tags, use_reserve);
3015
3016         if (new_chunk_id > 0) {
3017                 yaffs_put_chunk_in_file(in, inode_chunk, new_chunk_id, 0);
3018
3019                 if (prev_chunk_id > 0)
3020                         yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
3021
3022                 yaffs_verify_file_sane(in);
3023         }
3024         return new_chunk_id;
3025
3026 }
3027
3028
3029
3030 static int yaffs_do_xattrib_mod(struct yaffs_obj *obj, int set,
3031                                 const YCHAR *name, const void *value, int size,
3032                                 int flags)
3033 {
3034         struct yaffs_xattr_mod xmod;
3035         int result;
3036
3037         xmod.set = set;
3038         xmod.name = name;
3039         xmod.data = value;
3040         xmod.size = size;
3041         xmod.flags = flags;
3042         xmod.result = -ENOSPC;
3043
3044         result = yaffs_update_oh(obj, NULL, 0, 0, 0, &xmod);
3045
3046         if (result > 0)
3047                 return xmod.result;
3048         else
3049                 return -ENOSPC;
3050 }
3051
3052 static int yaffs_apply_xattrib_mod(struct yaffs_obj *obj, char *buffer,
3053                                    struct yaffs_xattr_mod *xmod)
3054 {
3055         int retval = 0;
3056         int x_offs = sizeof(struct yaffs_obj_hdr);
3057         struct yaffs_dev *dev = obj->my_dev;
3058         int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
3059         char *x_buffer = buffer + x_offs;
3060
3061         if (xmod->set)
3062                 retval =
3063                     nval_set(x_buffer, x_size, xmod->name, xmod->data,
3064                              xmod->size, xmod->flags);
3065         else
3066                 retval = nval_del(x_buffer, x_size, xmod->name);
3067
3068         obj->has_xattr = nval_hasvalues(x_buffer, x_size);
3069         obj->xattr_known = 1;
3070         xmod->result = retval;
3071
3072         return retval;
3073 }
3074
3075 static int yaffs_do_xattrib_fetch(struct yaffs_obj *obj, const YCHAR *name,
3076                                   void *value, int size)
3077 {
3078         char *buffer = NULL;
3079         int result;
3080         struct yaffs_ext_tags tags;
3081         struct yaffs_dev *dev = obj->my_dev;
3082         int x_offs = sizeof(struct yaffs_obj_hdr);
3083         int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
3084         char *x_buffer;
3085         int retval = 0;
3086
3087         if (obj->hdr_chunk < 1)
3088                 return -ENODATA;
3089
3090         /* If we know that the object has no xattribs then don't do all the
3091          * reading and parsing.
3092          */
3093         if (obj->xattr_known && !obj->has_xattr) {
3094                 if (name)
3095                         return -ENODATA;
3096                 else
3097                         return 0;
3098         }
3099
3100         buffer = (char *)yaffs_get_temp_buffer(dev);
3101         if (!buffer)
3102                 return -ENOMEM;
3103
3104         result =
3105             yaffs_rd_chunk_tags_nand(dev, obj->hdr_chunk, (u8 *) buffer, &tags);
3106
3107         if (result != YAFFS_OK)
3108                 retval = -ENOENT;
3109         else {
3110                 x_buffer = buffer + x_offs;
3111
3112                 if (!obj->xattr_known) {
3113                         obj->has_xattr = nval_hasvalues(x_buffer, x_size);
3114                         obj->xattr_known = 1;
3115                 }
3116
3117                 if (name)
3118                         retval = nval_get(x_buffer, x_size, name, value, size);
3119                 else
3120                         retval = nval_list(x_buffer, x_size, value, size);
3121         }
3122         yaffs_release_temp_buffer(dev, (u8 *) buffer);
3123         return retval;
3124 }
3125
3126 int yaffs_set_xattrib(struct yaffs_obj *obj, const YCHAR * name,
3127                       const void *value, int size, int flags)
3128 {
3129         return yaffs_do_xattrib_mod(obj, 1, name, value, size, flags);
3130 }
3131
3132 int yaffs_remove_xattrib(struct yaffs_obj *obj, const YCHAR * name)
3133 {
3134         return yaffs_do_xattrib_mod(obj, 0, name, NULL, 0, 0);
3135 }
3136
3137 int yaffs_get_xattrib(struct yaffs_obj *obj, const YCHAR * name, void *value,
3138                       int size)
3139 {
3140         return yaffs_do_xattrib_fetch(obj, name, value, size);
3141 }
3142
3143 int yaffs_list_xattrib(struct yaffs_obj *obj, char *buffer, int size)
3144 {
3145         return yaffs_do_xattrib_fetch(obj, NULL, buffer, size);
3146 }
3147
3148 static void yaffs_check_obj_details_loaded(struct yaffs_obj *in)
3149 {
3150         u8 *buf;
3151         struct yaffs_obj_hdr *oh;
3152         struct yaffs_dev *dev;
3153         struct yaffs_ext_tags tags;
3154         int result;
3155         int alloc_failed = 0;
3156
3157         if (!in || !in->lazy_loaded || in->hdr_chunk < 1)
3158                 return;
3159
3160         dev = in->my_dev;
3161         in->lazy_loaded = 0;
3162         buf = yaffs_get_temp_buffer(dev);
3163
3164         result = yaffs_rd_chunk_tags_nand(dev, in->hdr_chunk, buf, &tags);
3165         oh = (struct yaffs_obj_hdr *)buf;
3166
3167         in->yst_mode = oh->yst_mode;
3168         yaffs_load_attribs(in, oh);
3169         yaffs_set_obj_name_from_oh(in, oh);
3170
3171         if (in->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
3172                 in->variant.symlink_variant.alias =
3173                     yaffs_clone_str(oh->alias);
3174                 if (!in->variant.symlink_variant.alias)
3175                         alloc_failed = 1;       /* Not returned */
3176         }
3177         yaffs_release_temp_buffer(dev, buf);
3178 }
3179
3180 static void yaffs_load_name_from_oh(struct yaffs_dev *dev, YCHAR *name,
3181                                     const YCHAR *oh_name, int buff_size)
3182 {
3183 #ifdef CONFIG_YAFFS_AUTO_UNICODE
3184         if (dev->param.auto_unicode) {
3185                 if (*oh_name) {
3186                         /* It is an ASCII name, do an ASCII to
3187                          * unicode conversion */
3188                         const char *ascii_oh_name = (const char *)oh_name;
3189                         int n = buff_size - 1;
3190                         while (n > 0 && *ascii_oh_name) {
3191                                 *name = *ascii_oh_name;
3192                                 name++;
3193                                 ascii_oh_name++;
3194                                 n--;
3195                         }
3196                 } else {
3197                         strncpy(name, oh_name + 1, buff_size - 1);
3198                 }
3199         } else {
3200 #else
3201         (void) dev;
3202         {
3203 #endif
3204                 strncpy(name, oh_name, buff_size - 1);
3205         }
3206 }
3207
3208 static void yaffs_load_oh_from_name(struct yaffs_dev *dev, YCHAR *oh_name,
3209                                     const YCHAR *name)
3210 {
3211 #ifdef CONFIG_YAFFS_AUTO_UNICODE
3212
3213         int is_ascii;
3214         YCHAR *w;
3215
3216         if (dev->param.auto_unicode) {
3217
3218                 is_ascii = 1;
3219                 w = name;
3220
3221                 /* Figure out if the name will fit in ascii character set */
3222                 while (is_ascii && *w) {
3223                         if ((*w) & 0xff00)
3224                                 is_ascii = 0;
3225                         w++;
3226                 }
3227
3228                 if (is_ascii) {
3229                         /* It is an ASCII name, so convert unicode to ascii */
3230                         char *ascii_oh_name = (char *)oh_name;
3231                         int n = YAFFS_MAX_NAME_LENGTH - 1;
3232                         while (n > 0 && *name) {
3233                                 *ascii_oh_name = *name;
3234                                 name++;
3235                                 ascii_oh_name++;
3236                                 n--;
3237                         }
3238                 } else {
3239                         /* Unicode name, so save starting at the second YCHAR */
3240                         *oh_name = 0;
3241                         strncpy(oh_name + 1, name, YAFFS_MAX_NAME_LENGTH - 2);
3242                 }
3243         } else {
3244 #else
3245         dev = dev;
3246         {
3247 #endif
3248                 strncpy(oh_name, name, YAFFS_MAX_NAME_LENGTH - 1);
3249         }
3250 }
3251
3252 /* UpdateObjectHeader updates the header on NAND for an object.
3253  * If name is not NULL, then that new name is used.
3254  */
3255 int yaffs_update_oh(struct yaffs_obj *in, const YCHAR *name, int force,
3256                     int is_shrink, int shadows, struct yaffs_xattr_mod *xmod)
3257 {
3258
3259         struct yaffs_block_info *bi;
3260         struct yaffs_dev *dev = in->my_dev;
3261         int prev_chunk_id;
3262         int ret_val = 0;
3263         int result = 0;
3264         int new_chunk_id;
3265         struct yaffs_ext_tags new_tags;
3266         struct yaffs_ext_tags old_tags;
3267         const YCHAR *alias = NULL;
3268         u8 *buffer = NULL;
3269         YCHAR old_name[YAFFS_MAX_NAME_LENGTH + 1];
3270         struct yaffs_obj_hdr *oh = NULL;
3271         loff_t file_size = 0;
3272
3273         strcpy(old_name, _Y("silly old name"));
3274
3275         if (in->fake && in != dev->root_dir && !force && !xmod)
3276                 return ret_val;
3277
3278         yaffs_check_gc(dev, 0);
3279         yaffs_check_obj_details_loaded(in);
3280
3281         buffer = yaffs_get_temp_buffer(in->my_dev);
3282         oh = (struct yaffs_obj_hdr *)buffer;
3283
3284         prev_chunk_id = in->hdr_chunk;
3285
3286         if (prev_chunk_id > 0) {
3287                 result = yaffs_rd_chunk_tags_nand(dev, prev_chunk_id,
3288                                                   buffer, &old_tags);
3289
3290                 yaffs_verify_oh(in, oh, &old_tags, 0);
3291                 memcpy(old_name, oh->name, sizeof(oh->name));
3292                 memset(buffer, 0xff, sizeof(struct yaffs_obj_hdr));
3293         } else {
3294                 memset(buffer, 0xff, dev->data_bytes_per_chunk);
3295         }
3296
3297         oh->type = in->variant_type;
3298         oh->yst_mode = in->yst_mode;
3299         oh->shadows_obj = oh->inband_shadowed_obj_id = shadows;
3300
3301         yaffs_load_attribs_oh(oh, in);
3302
3303         if (in->parent)
3304                 oh->parent_obj_id = in->parent->obj_id;
3305         else
3306                 oh->parent_obj_id = 0;
3307
3308         if (name && *name) {
3309                 memset(oh->name, 0, sizeof(oh->name));
3310                 yaffs_load_oh_from_name(dev, oh->name, name);
3311         } else if (prev_chunk_id > 0) {
3312                 memcpy(oh->name, old_name, sizeof(oh->name));
3313         } else {
3314                 memset(oh->name, 0, sizeof(oh->name));
3315         }
3316
3317         oh->is_shrink = is_shrink;
3318
3319         switch (in->variant_type) {
3320         case YAFFS_OBJECT_TYPE_UNKNOWN:
3321                 /* Should not happen */
3322                 break;
3323         case YAFFS_OBJECT_TYPE_FILE:
3324                 if (oh->parent_obj_id != YAFFS_OBJECTID_DELETED &&
3325                     oh->parent_obj_id != YAFFS_OBJECTID_UNLINKED)
3326                         file_size = in->variant.file_variant.file_size;
3327                 yaffs_oh_size_load(oh, file_size);
3328                 break;
3329         case YAFFS_OBJECT_TYPE_HARDLINK:
3330                 oh->equiv_id = in->variant.hardlink_variant.equiv_id;
3331                 break;
3332         case YAFFS_OBJECT_TYPE_SPECIAL:
3333                 /* Do nothing */
3334                 break;
3335         case YAFFS_OBJECT_TYPE_DIRECTORY:
3336                 /* Do nothing */
3337                 break;
3338         case YAFFS_OBJECT_TYPE_SYMLINK:
3339                 alias = in->variant.symlink_variant.alias;
3340                 if (!alias)
3341                         alias = _Y("no alias");
3342                 strncpy(oh->alias, alias, YAFFS_MAX_ALIAS_LENGTH);
3343                 oh->alias[YAFFS_MAX_ALIAS_LENGTH] = 0;
3344                 break;
3345         }
3346
3347         /* process any xattrib modifications */
3348         if (xmod)
3349                 yaffs_apply_xattrib_mod(in, (char *)buffer, xmod);
3350
3351         /* Tags */
3352         memset(&new_tags, 0, sizeof(new_tags));
3353         in->serial++;
3354         new_tags.chunk_id = 0;
3355         new_tags.obj_id = in->obj_id;
3356         new_tags.serial_number = in->serial;
3357
3358         /* Add extra info for file header */
3359         new_tags.extra_available = 1;
3360         new_tags.extra_parent_id = oh->parent_obj_id;
3361         new_tags.extra_file_size = file_size;
3362         new_tags.extra_is_shrink = oh->is_shrink;
3363         new_tags.extra_equiv_id = oh->equiv_id;
3364         new_tags.extra_shadows = (oh->shadows_obj > 0) ? 1 : 0;
3365         new_tags.extra_obj_type = in->variant_type;
3366         yaffs_verify_oh(in, oh, &new_tags, 1);
3367
3368         /* Create new chunk in NAND */
3369         new_chunk_id =
3370             yaffs_write_new_chunk(dev, buffer, &new_tags,
3371                                   (prev_chunk_id > 0) ? 1 : 0);
3372
3373         if (buffer)
3374                 yaffs_release_temp_buffer(dev, buffer);
3375
3376         if (new_chunk_id < 0)
3377                 return new_chunk_id;
3378
3379         in->hdr_chunk = new_chunk_id;
3380
3381         if (prev_chunk_id > 0)
3382                 yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
3383
3384         if (!yaffs_obj_cache_dirty(in))
3385                 in->dirty = 0;
3386
3387         /* If this was a shrink, then mark the block
3388          * that the chunk lives on */
3389         if (is_shrink) {
3390                 bi = yaffs_get_block_info(in->my_dev,
3391                                           new_chunk_id /
3392                                           in->my_dev->param.chunks_per_block);
3393                 bi->has_shrink_hdr = 1;
3394         }
3395
3396
3397         return new_chunk_id;
3398 }
3399
3400 /*--------------------- File read/write ------------------------
3401  * Read and write have very similar structures.
3402  * In general the read/write has three parts to it
3403  * An incomplete chunk to start with (if the read/write is not chunk-aligned)
3404  * Some complete chunks
3405  * An incomplete chunk to end off with
3406  *
3407  * Curve-balls: the first chunk might also be the last chunk.
3408  */
3409
3410 int yaffs_file_rd(struct yaffs_obj *in, u8 * buffer, loff_t offset, int n_bytes)
3411 {
3412         int chunk;
3413         u32 start;
3414         int n_copy;
3415         int n = n_bytes;
3416         int n_done = 0;
3417         struct yaffs_cache *cache;
3418         struct yaffs_dev *dev;
3419
3420         dev = in->my_dev;
3421
3422         while (n > 0) {
3423                 yaffs_addr_to_chunk(dev, offset, &chunk, &start);
3424                 chunk++;
3425
3426                 /* OK now check for the curveball where the start and end are in
3427                  * the same chunk.
3428                  */
3429                 if ((start + n) < dev->data_bytes_per_chunk)
3430                         n_copy = n;
3431                 else
3432                         n_copy = dev->data_bytes_per_chunk - start;
3433
3434                 cache = yaffs_find_chunk_cache(in, chunk);
3435
3436                 /* If the chunk is already in the cache or it is less than
3437                  * a whole chunk or we're using inband tags then use the cache
3438                  * (if there is caching) else bypass the cache.
3439                  */
3440                 if (cache || n_copy != dev->data_bytes_per_chunk ||
3441                     dev->param.inband_tags) {
3442                         if (dev->param.n_caches > 0) {
3443
3444                                 /* If we can't find the data in the cache,
3445                                  * then load it up. */
3446
3447                                 if (!cache) {
3448                                         cache =
3449                                             yaffs_grab_chunk_cache(in->my_dev);
3450                                         cache->object = in;
3451                                         cache->chunk_id = chunk;
3452                                         cache->dirty = 0;
3453                                         cache->locked = 0;
3454                                         yaffs_rd_data_obj(in, chunk,
3455                                                           cache->data);
3456                                         cache->n_bytes = 0;
3457                                 }
3458
3459                                 yaffs_use_cache(dev, cache, 0);
3460
3461                                 cache->locked = 1;
3462
3463                                 memcpy(buffer, &cache->data[start], n_copy);
3464
3465                                 cache->locked = 0;
3466                         } else {
3467                                 /* Read into the local buffer then copy.. */
3468
3469                                 u8 *local_buffer =
3470                                     yaffs_get_temp_buffer(dev);
3471                                 yaffs_rd_data_obj(in, chunk, local_buffer);
3472
3473                                 memcpy(buffer, &local_buffer[start], n_copy);
3474
3475                                 yaffs_release_temp_buffer(dev, local_buffer);
3476                         }
3477                 } else {
3478                         /* A full chunk. Read directly into the buffer. */
3479                         yaffs_rd_data_obj(in, chunk, buffer);
3480                 }
3481                 n -= n_copy;
3482                 offset += n_copy;
3483                 buffer += n_copy;
3484                 n_done += n_copy;
3485         }
3486         return n_done;
3487 }
3488
3489 int yaffs_do_file_wr(struct yaffs_obj *in, const u8 *buffer, loff_t offset,
3490                      int n_bytes, int write_through)
3491 {
3492
3493         int chunk;
3494         u32 start;
3495         int n_copy;
3496         int n = n_bytes;
3497         int n_done = 0;
3498         int n_writeback;
3499         loff_t start_write = offset;
3500         int chunk_written = 0;
3501         u32 n_bytes_read;
3502         loff_t chunk_start;
3503         struct yaffs_dev *dev;
3504
3505         dev = in->my_dev;
3506
3507         while (n > 0 && chunk_written >= 0) {
3508                 yaffs_addr_to_chunk(dev, offset, &chunk, &start);
3509
3510                 if (((loff_t)chunk) *
3511                     dev->data_bytes_per_chunk + start != offset ||
3512                     start >= dev->data_bytes_per_chunk) {
3513                         yaffs_trace(YAFFS_TRACE_ERROR,
3514                                 "AddrToChunk of offset %lld gives chunk %d start %d",
3515                                 offset, chunk, start);
3516                 }
3517                 chunk++;        /* File pos to chunk in file offset */
3518
3519                 /* OK now check for the curveball where the start and end are in
3520                  * the same chunk.
3521                  */
3522
3523                 if ((start + n) < dev->data_bytes_per_chunk) {
3524                         n_copy = n;
3525
3526                         /* Now calculate how many bytes to write back....
3527                          * If we're overwriting and not writing to then end of
3528                          * file then we need to write back as much as was there
3529                          * before.
3530                          */
3531
3532                         chunk_start = (((loff_t)(chunk - 1)) *
3533                                         dev->data_bytes_per_chunk);
3534
3535                         if (chunk_start > in->variant.file_variant.file_size)
3536                                 n_bytes_read = 0;       /* Past end of file */
3537                         else
3538                                 n_bytes_read =
3539                                     in->variant.file_variant.file_size -
3540                                     chunk_start;
3541
3542                         if (n_bytes_read > dev->data_bytes_per_chunk)
3543                                 n_bytes_read = dev->data_bytes_per_chunk;
3544
3545                         n_writeback =
3546                             (n_bytes_read >
3547                              (start + n)) ? n_bytes_read : (start + n);
3548
3549                         if (n_writeback < 0 ||
3550                             n_writeback > dev->data_bytes_per_chunk)
3551                                 BUG();
3552
3553                 } else {
3554                         n_copy = dev->data_bytes_per_chunk - start;
3555                         n_writeback = dev->data_bytes_per_chunk;
3556                 }
3557
3558                 if (n_copy != dev->data_bytes_per_chunk ||
3559                     dev->param.inband_tags) {
3560                         /* An incomplete start or end chunk (or maybe both
3561                          * start and end chunk), or we're using inband tags,
3562                          * so we want to use the cache buffers.
3563                          */
3564                         if (dev->param.n_caches > 0) {
3565                                 struct yaffs_cache *cache;
3566
3567                                 /* If we can't find the data in the cache, then
3568                                  * load the cache */
3569                                 cache = yaffs_find_chunk_cache(in, chunk);
3570
3571                                 if (!cache &&
3572                                     yaffs_check_alloc_available(dev, 1)) {
3573                                         cache = yaffs_grab_chunk_cache(dev);
3574                                         cache->object = in;
3575                                         cache->chunk_id = chunk;
3576                                         cache->dirty = 0;
3577                                         cache->locked = 0;
3578                                         yaffs_rd_data_obj(in, chunk,
3579                                                           cache->data);
3580                                 } else if (cache &&
3581                                            !cache->dirty &&
3582                                            !yaffs_check_alloc_available(dev,
3583                                                                         1)) {
3584                                         /* Drop the cache if it was a read cache
3585                                          * item and no space check has been made
3586                                          * for it.
3587                                          */
3588                                         cache = NULL;
3589                                 }
3590
3591                                 if (cache) {
3592                                         yaffs_use_cache(dev, cache, 1);
3593                                         cache->locked = 1;
3594
3595                                         memcpy(&cache->data[start], buffer,
3596                                                n_copy);
3597
3598                                         cache->locked = 0;
3599                                         cache->n_bytes = n_writeback;
3600
3601                                         if (write_through) {
3602                                                 chunk_written =
3603                                                     yaffs_wr_data_obj
3604                                                     (cache->object,
3605                                                      cache->chunk_id,
3606                                                      cache->data,
3607                                                      cache->n_bytes, 1);
3608                                                 cache->dirty = 0;
3609                                         }
3610                                 } else {
3611                                         chunk_written = -1;     /* fail write */
3612                                 }
3613                         } else {
3614                                 /* An incomplete start or end chunk (or maybe
3615                                  * both start and end chunk). Read into the
3616                                  * local buffer then copy over and write back.
3617                                  */
3618
3619                                 u8 *local_buffer = yaffs_get_temp_buffer(dev);
3620
3621                                 yaffs_rd_data_obj(in, chunk, local_buffer);
3622                                 memcpy(&local_buffer[start], buffer, n_copy);
3623
3624                                 chunk_written =
3625                                     yaffs_wr_data_obj(in, chunk,
3626                                                       local_buffer,
3627                                                       n_writeback, 0);
3628
3629                                 yaffs_release_temp_buffer(dev, local_buffer);
3630                         }
3631                 } else {
3632                         /* A full chunk. Write directly from the buffer. */
3633
3634                         chunk_written =
3635                             yaffs_wr_data_obj(in, chunk, buffer,
3636                                               dev->data_bytes_per_chunk, 0);
3637
3638                         /* Since we've overwritten the cached data,
3639                          * we better invalidate it. */
3640                         yaffs_invalidate_chunk_cache(in, chunk);
3641                 }
3642
3643                 if (chunk_written >= 0) {
3644                         n -= n_copy;
3645                         offset += n_copy;
3646                         buffer += n_copy;
3647                         n_done += n_copy;
3648                 }
3649         }
3650
3651         /* Update file object */
3652
3653         if ((start_write + n_done) > in->variant.file_variant.file_size)
3654                 in->variant.file_variant.file_size = (start_write + n_done);
3655
3656         in->dirty = 1;
3657         return n_done;
3658 }
3659
3660 int yaffs_wr_file(struct yaffs_obj *in, const u8 *buffer, loff_t offset,
3661                   int n_bytes, int write_through)
3662 {
3663         yaffs2_handle_hole(in, offset);
3664         return yaffs_do_file_wr(in, buffer, offset, n_bytes, write_through);
3665 }
3666
3667 /* ---------------------- File resizing stuff ------------------ */
3668
3669 static void yaffs_prune_chunks(struct yaffs_obj *in, loff_t new_size)
3670 {
3671
3672         struct yaffs_dev *dev = in->my_dev;
3673         loff_t old_size = in->variant.file_variant.file_size;
3674         int i;
3675         int chunk_id;
3676         u32 dummy;
3677         int last_del;
3678         int start_del;
3679
3680         if (old_size > 0)
3681                 yaffs_addr_to_chunk(dev, old_size - 1, &last_del, &dummy);
3682         else
3683                 last_del = 0;
3684
3685         yaffs_addr_to_chunk(dev, new_size + dev->data_bytes_per_chunk - 1,
3686                                 &start_del, &dummy);
3687         last_del++;
3688         start_del++;
3689
3690         /* Delete backwards so that we don't end up with holes if
3691          * power is lost part-way through the operation.
3692          */
3693         for (i = last_del; i >= start_del; i--) {
3694                 /* NB this could be optimised somewhat,
3695                  * eg. could retrieve the tags and write them without
3696                  * using yaffs_chunk_del
3697                  */
3698
3699                 chunk_id = yaffs_find_del_file_chunk(in, i, NULL);
3700
3701                 if (chunk_id < 1)
3702                         continue;
3703
3704                 if (chunk_id <
3705                     (dev->internal_start_block * dev->param.chunks_per_block) ||
3706                     chunk_id >=
3707                     ((dev->internal_end_block + 1) *
3708                       dev->param.chunks_per_block)) {
3709                         yaffs_trace(YAFFS_TRACE_ALWAYS,
3710                                 "Found daft chunk_id %d for %d",
3711                                 chunk_id, i);
3712                 } else {
3713                         in->n_data_chunks--;
3714                         yaffs_chunk_del(dev, chunk_id, 1, __LINE__);
3715                 }
3716         }
3717 }
3718
3719 void yaffs_resize_file_down(struct yaffs_obj *obj, loff_t new_size)
3720 {
3721         int new_full;
3722         u32 new_partial;
3723         struct yaffs_dev *dev = obj->my_dev;
3724
3725         yaffs_addr_to_chunk(dev, new_size, &new_full, &new_partial);
3726
3727         yaffs_prune_chunks(obj, new_size);
3728
3729         if (new_partial != 0) {
3730                 int last_chunk = 1 + new_full;
3731                 u8 *local_buffer = yaffs_get_temp_buffer(dev);
3732
3733                 /* Rewrite the last chunk with its new size and zero pad */
3734                 yaffs_rd_data_obj(obj, last_chunk, local_buffer);
3735                 memset(local_buffer + new_partial, 0,
3736                        dev->data_bytes_per_chunk - new_partial);
3737
3738                 yaffs_wr_data_obj(obj, last_chunk, local_buffer,
3739                                   new_partial, 1);
3740
3741                 yaffs_release_temp_buffer(dev, local_buffer);
3742         }
3743
3744         obj->variant.file_variant.file_size = new_size;
3745
3746         yaffs_prune_tree(dev, &obj->variant.file_variant);
3747 }
3748
3749 int yaffs_resize_file(struct yaffs_obj *in, loff_t new_size)
3750 {
3751         struct yaffs_dev *dev = in->my_dev;
3752         loff_t old_size = in->variant.file_variant.file_size;
3753
3754         yaffs_flush_file_cache(in);
3755         yaffs_invalidate_whole_cache(in);
3756
3757         yaffs_check_gc(dev, 0);
3758
3759         if (in->variant_type != YAFFS_OBJECT_TYPE_FILE)
3760                 return YAFFS_FAIL;
3761
3762         if (new_size == old_size)
3763                 return YAFFS_OK;
3764
3765         if (new_size > old_size) {
3766                 yaffs2_handle_hole(in, new_size);
3767                 in->variant.file_variant.file_size = new_size;
3768         } else {
3769                 /* new_size < old_size */
3770                 yaffs_resize_file_down(in, new_size);
3771         }
3772
3773         /* Write a new object header to reflect the resize.
3774          * show we've shrunk the file, if need be
3775          * Do this only if the file is not in the deleted directories
3776          * and is not shadowed.
3777          */
3778         if (in->parent &&
3779             !in->is_shadowed &&
3780             in->parent->obj_id != YAFFS_OBJECTID_UNLINKED &&
3781             in->parent->obj_id != YAFFS_OBJECTID_DELETED)
3782                 yaffs_update_oh(in, NULL, 0, 0, 0, NULL);
3783
3784         return YAFFS_OK;
3785 }
3786
3787 int yaffs_flush_file(struct yaffs_obj *in, int update_time, int data_sync)
3788 {
3789         if (!in->dirty)
3790                 return YAFFS_OK;
3791
3792         yaffs_flush_file_cache(in);
3793
3794         if (data_sync)
3795                 return YAFFS_OK;
3796
3797         if (update_time)
3798                 yaffs_load_current_time(in, 0, 0);
3799
3800         return (yaffs_update_oh(in, NULL, 0, 0, 0, NULL) >= 0) ?
3801                                 YAFFS_OK : YAFFS_FAIL;
3802 }
3803
3804
3805 /* yaffs_del_file deletes the whole file data
3806  * and the inode associated with the file.
3807  * It does not delete the links associated with the file.
3808  */
3809 static int yaffs_unlink_file_if_needed(struct yaffs_obj *in)
3810 {
3811         int ret_val;
3812         int del_now = 0;
3813         struct yaffs_dev *dev = in->my_dev;
3814
3815         if (!in->my_inode)
3816                 del_now = 1;
3817
3818         if (del_now) {
3819                 ret_val =
3820                     yaffs_change_obj_name(in, in->my_dev->del_dir,
3821                                           _Y("deleted"), 0, 0);
3822                 yaffs_trace(YAFFS_TRACE_TRACING,
3823                         "yaffs: immediate deletion of file %d",
3824                         in->obj_id);
3825                 in->deleted = 1;
3826                 in->my_dev->n_deleted_files++;
3827                 if (dev->param.disable_soft_del || dev->param.is_yaffs2)
3828                         yaffs_resize_file(in, 0);
3829                 yaffs_soft_del_file(in);
3830         } else {
3831                 ret_val =
3832                     yaffs_change_obj_name(in, in->my_dev->unlinked_dir,
3833                                           _Y("unlinked"), 0, 0);
3834         }
3835         return ret_val;
3836 }
3837
3838 static int yaffs_del_file(struct yaffs_obj *in)
3839 {
3840         int ret_val = YAFFS_OK;
3841         int deleted;    /* Need to cache value on stack if in is freed */
3842         struct yaffs_dev *dev = in->my_dev;
3843
3844         if (dev->param.disable_soft_del || dev->param.is_yaffs2)
3845                 yaffs_resize_file(in, 0);
3846
3847         if (in->n_data_chunks > 0) {
3848                 /* Use soft deletion if there is data in the file.
3849                  * That won't be the case if it has been resized to zero.
3850                  */
3851                 if (!in->unlinked)
3852                         ret_val = yaffs_unlink_file_if_needed(in);
3853
3854                 deleted = in->deleted;
3855
3856                 if (ret_val == YAFFS_OK && in->unlinked && !in->deleted) {
3857                         in->deleted = 1;
3858                         deleted = 1;
3859                         in->my_dev->n_deleted_files++;
3860                         yaffs_soft_del_file(in);
3861                 }
3862                 return deleted ? YAFFS_OK : YAFFS_FAIL;
3863         } else {
3864                 /* The file has no data chunks so we toss it immediately */
3865                 yaffs_free_tnode(in->my_dev, in->variant.file_variant.top);
3866                 in->variant.file_variant.top = NULL;
3867                 yaffs_generic_obj_del(in);
3868
3869                 return YAFFS_OK;
3870         }
3871 }
3872
3873 int yaffs_is_non_empty_dir(struct yaffs_obj *obj)
3874 {
3875         return (obj &&
3876                 obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY) &&
3877                 !(list_empty(&obj->variant.dir_variant.children));
3878 }
3879
3880 static int yaffs_del_dir(struct yaffs_obj *obj)
3881 {
3882         /* First check that the directory is empty. */
3883         if (yaffs_is_non_empty_dir(obj))
3884                 return YAFFS_FAIL;
3885
3886         return yaffs_generic_obj_del(obj);
3887 }
3888
3889 static int yaffs_del_symlink(struct yaffs_obj *in)
3890 {
3891         kfree(in->variant.symlink_variant.alias);
3892         in->variant.symlink_variant.alias = NULL;
3893
3894         return yaffs_generic_obj_del(in);
3895 }
3896
3897 static int yaffs_del_link(struct yaffs_obj *in)
3898 {
3899         /* remove this hardlink from the list associated with the equivalent
3900          * object
3901          */
3902         list_del_init(&in->hard_links);
3903         return yaffs_generic_obj_del(in);
3904 }
3905
3906 int yaffs_del_obj(struct yaffs_obj *obj)
3907 {
3908         int ret_val = -1;
3909
3910         switch (obj->variant_type) {
3911         case YAFFS_OBJECT_TYPE_FILE:
3912                 ret_val = yaffs_del_file(obj);
3913                 break;
3914         case YAFFS_OBJECT_TYPE_DIRECTORY:
3915                 if (!list_empty(&obj->variant.dir_variant.dirty)) {
3916                         yaffs_trace(YAFFS_TRACE_BACKGROUND,
3917                                 "Remove object %d from dirty directories",
3918                                 obj->obj_id);
3919                         list_del_init(&obj->variant.dir_variant.dirty);
3920                 }
3921                 return yaffs_del_dir(obj);
3922                 break;
3923         case YAFFS_OBJECT_TYPE_SYMLINK:
3924                 ret_val = yaffs_del_symlink(obj);
3925                 break;
3926         case YAFFS_OBJECT_TYPE_HARDLINK:
3927                 ret_val = yaffs_del_link(obj);
3928                 break;
3929         case YAFFS_OBJECT_TYPE_SPECIAL:
3930                 ret_val = yaffs_generic_obj_del(obj);
3931                 break;
3932         case YAFFS_OBJECT_TYPE_UNKNOWN:
3933                 ret_val = 0;
3934                 break;          /* should not happen. */
3935         }
3936         return ret_val;
3937 }
3938
3939 static int yaffs_unlink_worker(struct yaffs_obj *obj)
3940 {
3941         int del_now = 0;
3942
3943         if (!obj)
3944                 return YAFFS_FAIL;
3945
3946         if (!obj->my_inode)
3947                 del_now = 1;
3948
3949         yaffs_update_parent(obj->parent);
3950
3951         if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
3952                 return yaffs_del_link(obj);
3953         } else if (!list_empty(&obj->hard_links)) {
3954                 /* Curve ball: We're unlinking an object that has a hardlink.
3955                  *
3956                  * This problem arises because we are not strictly following
3957                  * The Linux link/inode model.
3958                  *
3959                  * We can't really delete the object.
3960                  * Instead, we do the following:
3961                  * - Select a hardlink.
3962                  * - Unhook it from the hard links
3963                  * - Move it from its parent directory so that the rename works.
3964                  * - Rename the object to the hardlink's name.
3965                  * - Delete the hardlink
3966                  */
3967
3968                 struct yaffs_obj *hl;
3969                 struct yaffs_obj *parent;
3970                 int ret_val;
3971                 YCHAR name[YAFFS_MAX_NAME_LENGTH + 1];
3972
3973                 hl = list_entry(obj->hard_links.next, struct yaffs_obj,
3974                                 hard_links);
3975
3976                 yaffs_get_obj_name(hl, name, YAFFS_MAX_NAME_LENGTH + 1);
3977                 parent = hl->parent;
3978
3979                 list_del_init(&hl->hard_links);
3980
3981                 yaffs_add_obj_to_dir(obj->my_dev->unlinked_dir, hl);
3982
3983                 ret_val = yaffs_change_obj_name(obj, parent, name, 0, 0);
3984
3985                 if (ret_val == YAFFS_OK)
3986                         ret_val = yaffs_generic_obj_del(hl);
3987
3988                 return ret_val;
3989
3990         } else if (del_now) {
3991                 switch (obj->variant_type) {
3992                 case YAFFS_OBJECT_TYPE_FILE:
3993                         return yaffs_del_file(obj);
3994                         break;
3995                 case YAFFS_OBJECT_TYPE_DIRECTORY:
3996                         list_del_init(&obj->variant.dir_variant.dirty);
3997                         return yaffs_del_dir(obj);
3998                         break;
3999                 case YAFFS_OBJECT_TYPE_SYMLINK:
4000                         return yaffs_del_symlink(obj);
4001                         break;
4002                 case YAFFS_OBJECT_TYPE_SPECIAL:
4003                         return yaffs_generic_obj_del(obj);
4004                         break;
4005                 case YAFFS_OBJECT_TYPE_HARDLINK:
4006                 case YAFFS_OBJECT_TYPE_UNKNOWN:
4007                 default:
4008                         return YAFFS_FAIL;
4009                 }
4010         } else if (yaffs_is_non_empty_dir(obj)) {
4011                 return YAFFS_FAIL;
4012         } else {
4013                 return yaffs_change_obj_name(obj, obj->my_dev->unlinked_dir,
4014                                                 _Y("unlinked"), 0, 0);
4015         }
4016 }
4017
4018 static int yaffs_unlink_obj(struct yaffs_obj *obj)
4019 {
4020         if (obj && obj->unlink_allowed)
4021                 return yaffs_unlink_worker(obj);
4022
4023         return YAFFS_FAIL;
4024 }
4025
4026 int yaffs_unlinker(struct yaffs_obj *dir, const YCHAR *name)
4027 {
4028         struct yaffs_obj *obj;
4029
4030         obj = yaffs_find_by_name(dir, name);
4031         return yaffs_unlink_obj(obj);
4032 }
4033
4034 /* Note:
4035  * If old_name is NULL then we take old_dir as the object to be renamed.
4036  */
4037 int yaffs_rename_obj(struct yaffs_obj *old_dir, const YCHAR *old_name,
4038                      struct yaffs_obj *new_dir, const YCHAR *new_name)
4039 {
4040         struct yaffs_obj *obj = NULL;
4041         struct yaffs_obj *existing_target = NULL;
4042         int force = 0;
4043         int result;
4044         struct yaffs_dev *dev;
4045
4046         if (!old_dir || old_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4047                 BUG();
4048                 return YAFFS_FAIL;
4049         }
4050         if (!new_dir || new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4051                 BUG();
4052                 return YAFFS_FAIL;
4053         }
4054
4055         dev = old_dir->my_dev;
4056
4057 #ifdef CONFIG_YAFFS_CASE_INSENSITIVE
4058         /* Special case for case insemsitive systems.
4059          * While look-up is case insensitive, the name isn't.
4060          * Therefore we might want to change x.txt to X.txt
4061          */
4062         if (old_dir == new_dir &&
4063                 old_name && new_name &&
4064                 strcmp(old_name, new_name) == 0)
4065                 force = 1;
4066 #endif
4067
4068         if (strnlen(new_name, YAFFS_MAX_NAME_LENGTH + 1) >
4069             YAFFS_MAX_NAME_LENGTH)
4070                 /* ENAMETOOLONG */
4071                 return YAFFS_FAIL;
4072
4073         if (old_name)
4074                 obj = yaffs_find_by_name(old_dir, old_name);
4075         else{
4076                 obj = old_dir;
4077                 old_dir = obj->parent;
4078         }
4079
4080         if (obj && obj->rename_allowed) {
4081                 /* Now handle an existing target, if there is one */
4082                 existing_target = yaffs_find_by_name(new_dir, new_name);
4083                 if (yaffs_is_non_empty_dir(existing_target)) {
4084                         return YAFFS_FAIL;      /* ENOTEMPTY */
4085                 } else if (existing_target && existing_target != obj) {
4086                         /* Nuke the target first, using shadowing,
4087                          * but only if it isn't the same object.
4088                          *
4089                          * Note we must disable gc here otherwise it can mess
4090                          * up the shadowing.
4091                          *
4092                          */
4093                         dev->gc_disable = 1;
4094                         yaffs_change_obj_name(obj, new_dir, new_name, force,
4095                                               existing_target->obj_id);
4096                         existing_target->is_shadowed = 1;
4097                         yaffs_unlink_obj(existing_target);
4098                         dev->gc_disable = 0;
4099                 }
4100
4101                 result = yaffs_change_obj_name(obj, new_dir, new_name, 1, 0);
4102
4103                 yaffs_update_parent(old_dir);
4104                 if (new_dir != old_dir)
4105                         yaffs_update_parent(new_dir);
4106
4107                 return result;
4108         }
4109         return YAFFS_FAIL;
4110 }
4111
4112 /*----------------------- Initialisation Scanning ---------------------- */
4113
4114 void yaffs_handle_shadowed_obj(struct yaffs_dev *dev, int obj_id,
4115                                int backward_scanning)
4116 {
4117         struct yaffs_obj *obj;
4118
4119         if (backward_scanning) {
4120                 /* Handle YAFFS2 case (backward scanning)
4121                  * If the shadowed object exists then ignore.
4122                  */
4123                 obj = yaffs_find_by_number(dev, obj_id);
4124                 if (obj)
4125                         return;
4126         }
4127
4128         /* Let's create it (if it does not exist) assuming it is a file so that
4129          * it can do shrinking etc.
4130          * We put it in unlinked dir to be cleaned up after the scanning
4131          */
4132         obj =
4133             yaffs_find_or_create_by_number(dev, obj_id, YAFFS_OBJECT_TYPE_FILE);
4134         if (!obj)
4135                 return;
4136         obj->is_shadowed = 1;
4137         yaffs_add_obj_to_dir(dev->unlinked_dir, obj);
4138         obj->variant.file_variant.shrink_size = 0;
4139         obj->valid = 1;         /* So that we don't read any other info. */
4140 }
4141
4142 void yaffs_link_fixup(struct yaffs_dev *dev, struct list_head *hard_list)
4143 {
4144         struct list_head *lh;
4145         struct list_head *save;
4146         struct yaffs_obj *hl;
4147         struct yaffs_obj *in;
4148
4149         list_for_each_safe(lh, save, hard_list) {
4150                 hl = list_entry(lh, struct yaffs_obj, hard_links);
4151                 in = yaffs_find_by_number(dev,
4152                                         hl->variant.hardlink_variant.equiv_id);
4153
4154                 if (in) {
4155                         /* Add the hardlink pointers */
4156                         hl->variant.hardlink_variant.equiv_obj = in;
4157                         list_add(&hl->hard_links, &in->hard_links);
4158                 } else {
4159                         /* Todo Need to report/handle this better.
4160                          * Got a problem... hardlink to a non-existant object
4161                          */
4162                         hl->variant.hardlink_variant.equiv_obj = NULL;
4163                         INIT_LIST_HEAD(&hl->hard_links);
4164                 }
4165         }
4166 }
4167
4168 static void yaffs_strip_deleted_objs(struct yaffs_dev *dev)
4169 {
4170         /*
4171          *  Sort out state of unlinked and deleted objects after scanning.
4172          */
4173         struct list_head *i;
4174         struct list_head *n;
4175         struct yaffs_obj *l;
4176
4177         if (dev->read_only)
4178                 return;
4179
4180         /* Soft delete all the unlinked files */
4181         list_for_each_safe(i, n,
4182                            &dev->unlinked_dir->variant.dir_variant.children) {
4183                 l = list_entry(i, struct yaffs_obj, siblings);
4184                 yaffs_del_obj(l);
4185         }
4186
4187         list_for_each_safe(i, n, &dev->del_dir->variant.dir_variant.children) {
4188                 l = list_entry(i, struct yaffs_obj, siblings);
4189                 yaffs_del_obj(l);
4190         }
4191 }
4192
4193 /*
4194  * This code iterates through all the objects making sure that they are rooted.
4195  * Any unrooted objects are re-rooted in lost+found.
4196  * An object needs to be in one of:
4197  * - Directly under deleted, unlinked
4198  * - Directly or indirectly under root.
4199  *
4200  * Note:
4201  *  This code assumes that we don't ever change the current relationships
4202  *  between directories:
4203  *   root_dir->parent == unlinked_dir->parent == del_dir->parent == NULL
4204  *   lost-n-found->parent == root_dir
4205  *
4206  * This fixes the problem where directories might have inadvertently been
4207  * deleted leaving the object "hanging" without being rooted in the
4208  * directory tree.
4209  */
4210
4211 static int yaffs_has_null_parent(struct yaffs_dev *dev, struct yaffs_obj *obj)
4212 {
4213         return (obj == dev->del_dir ||
4214                 obj == dev->unlinked_dir || obj == dev->root_dir);
4215 }
4216
4217 static void yaffs_fix_hanging_objs(struct yaffs_dev *dev)
4218 {
4219         struct yaffs_obj *obj;
4220         struct yaffs_obj *parent;
4221         int i;
4222         struct list_head *lh;
4223         struct list_head *n;
4224         int depth_limit;
4225         int hanging;
4226
4227         if (dev->read_only)
4228                 return;
4229
4230         /* Iterate through the objects in each hash entry,
4231          * looking at each object.
4232          * Make sure it is rooted.
4233          */
4234
4235         for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
4236                 list_for_each_safe(lh, n, &dev->obj_bucket[i].list) {
4237                         obj = list_entry(lh, struct yaffs_obj, hash_link);
4238                         parent = obj->parent;
4239
4240                         if (yaffs_has_null_parent(dev, obj)) {
4241                                 /* These directories are not hanging */
4242                                 hanging = 0;
4243                         } else if (!parent ||
4244                                    parent->variant_type !=
4245                                    YAFFS_OBJECT_TYPE_DIRECTORY) {
4246                                 hanging = 1;
4247                         } else if (yaffs_has_null_parent(dev, parent)) {
4248                                 hanging = 0;
4249                         } else {
4250                                 /*
4251                                  * Need to follow the parent chain to
4252                                  * see if it is hanging.
4253                                  */
4254                                 hanging = 0;
4255                                 depth_limit = 100;
4256
4257                                 while (parent != dev->root_dir &&
4258                                        parent->parent &&
4259                                        parent->parent->variant_type ==
4260                                        YAFFS_OBJECT_TYPE_DIRECTORY &&
4261                                        depth_limit > 0) {
4262                                         parent = parent->parent;
4263                                         depth_limit--;
4264                                 }
4265                                 if (parent != dev->root_dir)
4266                                         hanging = 1;
4267                         }
4268                         if (hanging) {
4269                                 yaffs_trace(YAFFS_TRACE_SCAN,
4270                                         "Hanging object %d moved to lost and found",
4271                                         obj->obj_id);
4272                                 yaffs_add_obj_to_dir(dev->lost_n_found, obj);
4273                         }
4274                 }
4275         }
4276 }
4277
4278 /*
4279  * Delete directory contents for cleaning up lost and found.
4280  */
4281 static void yaffs_del_dir_contents(struct yaffs_obj *dir)
4282 {
4283         struct yaffs_obj *obj;
4284         struct list_head *lh;
4285         struct list_head *n;
4286
4287         if (dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
4288                 BUG();
4289
4290         list_for_each_safe(lh, n, &dir->variant.dir_variant.children) {
4291                 obj = list_entry(lh, struct yaffs_obj, siblings);
4292                 if (obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY)
4293                         yaffs_del_dir_contents(obj);
4294                 yaffs_trace(YAFFS_TRACE_SCAN,
4295                         "Deleting lost_found object %d",
4296                         obj->obj_id);
4297                 yaffs_unlink_obj(obj);
4298         }
4299 }
4300
4301 static void yaffs_empty_l_n_f(struct yaffs_dev *dev)
4302 {
4303         yaffs_del_dir_contents(dev->lost_n_found);
4304 }
4305
4306
4307 struct yaffs_obj *yaffs_find_by_name(struct yaffs_obj *directory,
4308                                      const YCHAR *name)
4309 {
4310         int sum;
4311         struct list_head *i;
4312         YCHAR buffer[YAFFS_MAX_NAME_LENGTH + 1];
4313         struct yaffs_obj *l;
4314
4315         if (!name)
4316                 return NULL;
4317
4318         if (!directory) {
4319                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4320                         "tragedy: yaffs_find_by_name: null pointer directory"
4321                         );
4322                 BUG();
4323                 return NULL;
4324         }
4325         if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4326                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4327                         "tragedy: yaffs_find_by_name: non-directory"
4328                         );
4329                 BUG();
4330         }
4331
4332         sum = yaffs_calc_name_sum(name);
4333
4334         list_for_each(i, &directory->variant.dir_variant.children) {
4335                 l = list_entry(i, struct yaffs_obj, siblings);
4336
4337                 if (l->parent != directory)
4338                         BUG();
4339
4340                 yaffs_check_obj_details_loaded(l);
4341
4342                 /* Special case for lost-n-found */
4343                 if (l->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
4344                         if (!strcmp(name, YAFFS_LOSTNFOUND_NAME))
4345                                 return l;
4346                 } else if (l->sum == sum || l->hdr_chunk <= 0) {
4347                         /* LostnFound chunk called Objxxx
4348                          * Do a real check
4349                          */
4350                         yaffs_get_obj_name(l, buffer,
4351                                 YAFFS_MAX_NAME_LENGTH + 1);
4352                         if (!strncmp(name, buffer, YAFFS_MAX_NAME_LENGTH))
4353                                 return l;
4354                 }
4355         }
4356         return NULL;
4357 }
4358
4359 /* GetEquivalentObject dereferences any hard links to get to the
4360  * actual object.
4361  */
4362
4363 struct yaffs_obj *yaffs_get_equivalent_obj(struct yaffs_obj *obj)
4364 {
4365         if (obj && obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
4366                 obj = obj->variant.hardlink_variant.equiv_obj;
4367                 yaffs_check_obj_details_loaded(obj);
4368         }
4369         return obj;
4370 }
4371
4372 /*
4373  *  A note or two on object names.
4374  *  * If the object name is missing, we then make one up in the form objnnn
4375  *
4376  *  * ASCII names are stored in the object header's name field from byte zero
4377  *  * Unicode names are historically stored starting from byte zero.
4378  *
4379  * Then there are automatic Unicode names...
4380  * The purpose of these is to save names in a way that can be read as
4381  * ASCII or Unicode names as appropriate, thus allowing a Unicode and ASCII
4382  * system to share files.
4383  *
4384  * These automatic unicode are stored slightly differently...
4385  *  - If the name can fit in the ASCII character space then they are saved as
4386  *    ascii names as per above.
4387  *  - If the name needs Unicode then the name is saved in Unicode
4388  *    starting at oh->name[1].
4389
4390  */
4391 static void yaffs_fix_null_name(struct yaffs_obj *obj, YCHAR *name,
4392                                 int buffer_size)
4393 {
4394         /* Create an object name if we could not find one. */
4395         if (strnlen(name, YAFFS_MAX_NAME_LENGTH) == 0) {
4396                 YCHAR local_name[20];
4397                 YCHAR num_string[20];
4398                 YCHAR *x = &num_string[19];
4399                 unsigned v = obj->obj_id;
4400                 num_string[19] = 0;
4401                 while (v > 0) {
4402                         x--;
4403                         *x = '0' + (v % 10);
4404                         v /= 10;
4405                 }
4406                 /* make up a name */
4407                 strcpy(local_name, YAFFS_LOSTNFOUND_PREFIX);
4408                 strcat(local_name, x);
4409                 strncpy(name, local_name, buffer_size - 1);
4410         }
4411 }
4412
4413 int yaffs_get_obj_name(struct yaffs_obj *obj, YCHAR *name, int buffer_size)
4414 {
4415         memset(name, 0, buffer_size * sizeof(YCHAR));
4416         yaffs_check_obj_details_loaded(obj);
4417         if (obj->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
4418                 strncpy(name, YAFFS_LOSTNFOUND_NAME, buffer_size - 1);
4419         } else if (obj->short_name[0]) {
4420                 strcpy(name, obj->short_name);
4421         } else if (obj->hdr_chunk > 0) {
4422                 int result;
4423                 u8 *buffer = yaffs_get_temp_buffer(obj->my_dev);
4424
4425                 struct yaffs_obj_hdr *oh = (struct yaffs_obj_hdr *)buffer;
4426
4427                 memset(buffer, 0, obj->my_dev->data_bytes_per_chunk);
4428
4429                 if (obj->hdr_chunk > 0) {
4430                         result = yaffs_rd_chunk_tags_nand(obj->my_dev,
4431                                                           obj->hdr_chunk,
4432                                                           buffer, NULL);
4433                 }
4434                 yaffs_load_name_from_oh(obj->my_dev, name, oh->name,
4435                                         buffer_size);
4436
4437                 yaffs_release_temp_buffer(obj->my_dev, buffer);
4438         }
4439
4440         yaffs_fix_null_name(obj, name, buffer_size);
4441
4442         return strnlen(name, YAFFS_MAX_NAME_LENGTH);
4443 }
4444
4445 loff_t yaffs_get_obj_length(struct yaffs_obj *obj)
4446 {
4447         /* Dereference any hard linking */
4448         obj = yaffs_get_equivalent_obj(obj);
4449
4450         if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
4451                 return obj->variant.file_variant.file_size;
4452         if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
4453                 if (!obj->variant.symlink_variant.alias)
4454                         return 0;
4455                 return strnlen(obj->variant.symlink_variant.alias,
4456                                      YAFFS_MAX_ALIAS_LENGTH);
4457         } else {
4458                 /* Only a directory should drop through to here */
4459                 return obj->my_dev->data_bytes_per_chunk;
4460         }
4461 }
4462
4463 int yaffs_get_obj_link_count(struct yaffs_obj *obj)
4464 {
4465         int count = 0;
4466         struct list_head *i;
4467
4468         if (!obj->unlinked)
4469                 count++;        /* the object itself */
4470
4471         list_for_each(i, &obj->hard_links)
4472             count++;            /* add the hard links; */
4473
4474         return count;
4475 }
4476
4477 int yaffs_get_obj_inode(struct yaffs_obj *obj)
4478 {
4479         obj = yaffs_get_equivalent_obj(obj);
4480
4481         return obj->obj_id;
4482 }
4483
4484 unsigned yaffs_get_obj_type(struct yaffs_obj *obj)
4485 {
4486         obj = yaffs_get_equivalent_obj(obj);
4487
4488         switch (obj->variant_type) {
4489         case YAFFS_OBJECT_TYPE_FILE:
4490                 return DT_REG;
4491                 break;
4492         case YAFFS_OBJECT_TYPE_DIRECTORY:
4493                 return DT_DIR;
4494                 break;
4495         case YAFFS_OBJECT_TYPE_SYMLINK:
4496                 return DT_LNK;
4497                 break;
4498         case YAFFS_OBJECT_TYPE_HARDLINK:
4499                 return DT_REG;
4500                 break;
4501         case YAFFS_OBJECT_TYPE_SPECIAL:
4502                 if (S_ISFIFO(obj->yst_mode))
4503                         return DT_FIFO;
4504                 if (S_ISCHR(obj->yst_mode))
4505                         return DT_CHR;
4506                 if (S_ISBLK(obj->yst_mode))
4507                         return DT_BLK;
4508                 if (S_ISSOCK(obj->yst_mode))
4509                         return DT_SOCK;
4510                 return DT_REG;
4511                 break;
4512         default:
4513                 return DT_REG;
4514                 break;
4515         }
4516 }
4517
4518 YCHAR *yaffs_get_symlink_alias(struct yaffs_obj *obj)
4519 {
4520         obj = yaffs_get_equivalent_obj(obj);
4521         if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK)
4522                 return yaffs_clone_str(obj->variant.symlink_variant.alias);
4523         else
4524                 return yaffs_clone_str(_Y(""));
4525 }
4526
4527 /*--------------------------- Initialisation code -------------------------- */
4528
4529 static int yaffs_check_dev_fns(const struct yaffs_dev *dev)
4530 {
4531         /* Common functions, gotta have */
4532         if (!dev->param.erase_fn || !dev->param.initialise_flash_fn)
4533                 return 0;
4534
4535         /* Can use the "with tags" style interface for yaffs1 or yaffs2 */
4536         if (dev->param.write_chunk_tags_fn &&
4537             dev->param.read_chunk_tags_fn &&
4538             !dev->param.write_chunk_fn &&
4539             !dev->param.read_chunk_fn &&
4540             dev->param.bad_block_fn && dev->param.query_block_fn)
4541                 return 1;
4542
4543         /* Can use the "spare" style interface for yaffs1 */
4544         if (!dev->param.is_yaffs2 &&
4545             !dev->param.write_chunk_tags_fn &&
4546             !dev->param.read_chunk_tags_fn &&
4547             dev->param.write_chunk_fn &&
4548             dev->param.read_chunk_fn &&
4549             !dev->param.bad_block_fn && !dev->param.query_block_fn)
4550                 return 1;
4551
4552         return 0;               /* bad */
4553 }
4554
4555 static int yaffs_create_initial_dir(struct yaffs_dev *dev)
4556 {
4557         /* Initialise the unlinked, deleted, root and lost+found directories */
4558         dev->lost_n_found = dev->root_dir = NULL;
4559         dev->unlinked_dir = dev->del_dir = NULL;
4560         dev->unlinked_dir =
4561             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_UNLINKED, S_IFDIR);
4562         dev->del_dir =
4563             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_DELETED, S_IFDIR);
4564         dev->root_dir =
4565             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_ROOT,
4566                                   YAFFS_ROOT_MODE | S_IFDIR);
4567         dev->lost_n_found =
4568             yaffs_create_fake_dir(dev, YAFFS_OBJECTID_LOSTNFOUND,
4569                                   YAFFS_LOSTNFOUND_MODE | S_IFDIR);
4570
4571         if (dev->lost_n_found && dev->root_dir && dev->unlinked_dir
4572             && dev->del_dir) {
4573                 yaffs_add_obj_to_dir(dev->root_dir, dev->lost_n_found);
4574                 return YAFFS_OK;
4575         }
4576         return YAFFS_FAIL;
4577 }
4578
4579 int yaffs_guts_initialise(struct yaffs_dev *dev)
4580 {
4581         int init_failed = 0;
4582         unsigned x;
4583         int bits;
4584
4585         yaffs_trace(YAFFS_TRACE_TRACING, "yaffs: yaffs_guts_initialise()");
4586
4587         /* Check stuff that must be set */
4588
4589         if (!dev) {
4590                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4591                         "yaffs: Need a device"
4592                         );
4593                 return YAFFS_FAIL;
4594         }
4595
4596         if (dev->is_mounted) {
4597                 yaffs_trace(YAFFS_TRACE_ALWAYS, "device already mounted");
4598                 return YAFFS_FAIL;
4599         }
4600
4601         dev->internal_start_block = dev->param.start_block;
4602         dev->internal_end_block = dev->param.end_block;
4603         dev->block_offset = 0;
4604         dev->chunk_offset = 0;
4605         dev->n_free_chunks = 0;
4606
4607         dev->gc_block = 0;
4608
4609         if (dev->param.start_block == 0) {
4610                 dev->internal_start_block = dev->param.start_block + 1;
4611                 dev->internal_end_block = dev->param.end_block + 1;
4612                 dev->block_offset = 1;
4613                 dev->chunk_offset = dev->param.chunks_per_block;
4614         }
4615
4616         /* Check geometry parameters. */
4617
4618         if ((!dev->param.inband_tags && dev->param.is_yaffs2 &&
4619                 dev->param.total_bytes_per_chunk < 1024) ||
4620                 (!dev->param.is_yaffs2 &&
4621                         dev->param.total_bytes_per_chunk < 512) ||
4622                 (dev->param.inband_tags && !dev->param.is_yaffs2) ||
4623                  dev->param.chunks_per_block < 2 ||
4624                  dev->param.n_reserved_blocks < 2 ||
4625                 dev->internal_start_block <= 0 ||
4626                 dev->internal_end_block <= 0 ||
4627                 dev->internal_end_block <=
4628                 (dev->internal_start_block + dev->param.n_reserved_blocks + 2)
4629                 ) {
4630                 /* otherwise it is too small */
4631                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4632                         "NAND geometry problems: chunk size %d, type is yaffs%s, inband_tags %d ",
4633                         dev->param.total_bytes_per_chunk,
4634                         dev->param.is_yaffs2 ? "2" : "",
4635                         dev->param.inband_tags);
4636                 return YAFFS_FAIL;
4637         }
4638
4639         if (yaffs_init_nand(dev) != YAFFS_OK) {
4640                 yaffs_trace(YAFFS_TRACE_ALWAYS, "InitialiseNAND failed");
4641                 return YAFFS_FAIL;
4642         }
4643
4644         /* Sort out space for inband tags, if required */
4645         if (dev->param.inband_tags)
4646                 dev->data_bytes_per_chunk =
4647                     dev->param.total_bytes_per_chunk -
4648                     sizeof(struct yaffs_packed_tags2_tags_only);
4649         else
4650                 dev->data_bytes_per_chunk = dev->param.total_bytes_per_chunk;
4651
4652         /* Got the right mix of functions? */
4653         if (!yaffs_check_dev_fns(dev)) {
4654                 /* Function missing */
4655                 yaffs_trace(YAFFS_TRACE_ALWAYS,
4656                         "device function(s) missing or wrong");
4657
4658                 return YAFFS_FAIL;
4659         }
4660
4661         /* Finished with most checks. Further checks happen later on too. */
4662
4663         dev->is_mounted = 1;
4664
4665         /* OK now calculate a few things for the device */
4666
4667         /*
4668          *  Calculate all the chunk size manipulation numbers:
4669          */
4670         x = dev->data_bytes_per_chunk;
4671         /* We always use dev->chunk_shift and dev->chunk_div */
4672         dev->chunk_shift = calc_shifts(x);
4673         x >>= dev->chunk_shift;
4674         dev->chunk_div = x;
4675         /* We only use chunk mask if chunk_div is 1 */
4676         dev->chunk_mask = (1 << dev->chunk_shift) - 1;
4677
4678         /*
4679          * Calculate chunk_grp_bits.
4680          * We need to find the next power of 2 > than internal_end_block
4681          */
4682
4683         x = dev->param.chunks_per_block * (dev->internal_end_block + 1);
4684
4685         bits = calc_shifts_ceiling(x);
4686
4687         /* Set up tnode width if wide tnodes are enabled. */
4688         if (!dev->param.wide_tnodes_disabled) {
4689                 /* bits must be even so that we end up with 32-bit words */
4690                 if (bits & 1)
4691                         bits++;
4692                 if (bits < 16)
4693                         dev->tnode_width = 16;
4694                 else
4695                         dev->tnode_width = bits;
4696         } else {
4697                 dev->tnode_width = 16;
4698         }
4699
4700         dev->tnode_mask = (1 << dev->tnode_width) - 1;
4701
4702         /* Level0 Tnodes are 16 bits or wider (if wide tnodes are enabled),
4703          * so if the bitwidth of the
4704          * chunk range we're using is greater than 16 we need
4705          * to figure out chunk shift and chunk_grp_size
4706          */
4707
4708         if (bits <= dev->tnode_width)
4709                 dev->chunk_grp_bits = 0;
4710         else
4711                 dev->chunk_grp_bits = bits - dev->tnode_width;
4712
4713         dev->tnode_size = (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8;
4714         if (dev->tnode_size < sizeof(struct yaffs_tnode))
4715                 dev->tnode_size = sizeof(struct yaffs_tnode);
4716
4717         dev->chunk_grp_size = 1 << dev->chunk_grp_bits;
4718
4719         if (dev->param.chunks_per_block < dev->chunk_grp_size) {
4720                 /* We have a problem because the soft delete won't work if
4721                  * the chunk group size > chunks per block.
4722                  * This can be remedied by using larger "virtual blocks".
4723                  */
4724                 yaffs_trace(YAFFS_TRACE_ALWAYS, "chunk group too large");
4725
4726                 return YAFFS_FAIL;
4727         }
4728
4729         /* Finished verifying the device, continue with initialisation */
4730
4731         /* More device initialisation */
4732         dev->all_gcs = 0;
4733         dev->passive_gc_count = 0;
4734         dev->oldest_dirty_gc_count = 0;
4735         dev->bg_gcs = 0;
4736         dev->gc_block_finder = 0;
4737         dev->buffered_block = -1;
4738         dev->doing_buffered_block_rewrite = 0;
4739         dev->n_deleted_files = 0;
4740         dev->n_bg_deletions = 0;
4741         dev->n_unlinked_files = 0;
4742         dev->n_ecc_fixed = 0;
4743         dev->n_ecc_unfixed = 0;
4744         dev->n_tags_ecc_fixed = 0;
4745         dev->n_tags_ecc_unfixed = 0;
4746         dev->n_erase_failures = 0;
4747         dev->n_erased_blocks = 0;
4748         dev->gc_disable = 0;
4749         dev->has_pending_prioritised_gc = 1;
4750                 /* Assume the worst for now, will get fixed on first GC */
4751         INIT_LIST_HEAD(&dev->dirty_dirs);
4752         dev->oldest_dirty_seq = 0;
4753         dev->oldest_dirty_block = 0;
4754
4755         /* Initialise temporary buffers and caches. */
4756         if (!yaffs_init_tmp_buffers(dev))
4757                 init_failed = 1;
4758
4759         dev->cache = NULL;
4760         dev->gc_cleanup_list = NULL;
4761
4762         if (!init_failed && dev->param.n_caches > 0) {
4763                 int i;
4764                 void *buf;
4765                 int cache_bytes =
4766                     dev->param.n_caches * sizeof(struct yaffs_cache);
4767
4768                 if (dev->param.n_caches > YAFFS_MAX_SHORT_OP_CACHES)
4769                         dev->param.n_caches = YAFFS_MAX_SHORT_OP_CACHES;
4770
4771                 dev->cache = kmalloc(cache_bytes, GFP_NOFS);
4772
4773                 buf = (u8 *) dev->cache;
4774
4775                 if (dev->cache)
4776                         memset(dev->cache, 0, cache_bytes);
4777
4778                 for (i = 0; i < dev->param.n_caches && buf; i++) {
4779                         dev->cache[i].object = NULL;
4780                         dev->cache[i].last_use = 0;
4781                         dev->cache[i].dirty = 0;
4782                         dev->cache[i].data = buf =
4783                             kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
4784                 }
4785                 if (!buf)
4786                         init_failed = 1;
4787
4788                 dev->cache_last_use = 0;
4789         }
4790
4791         dev->cache_hits = 0;
4792
4793         if (!init_failed) {
4794                 dev->gc_cleanup_list =
4795                     kmalloc(dev->param.chunks_per_block * sizeof(u32),
4796                                         GFP_NOFS);
4797                 if (!dev->gc_cleanup_list)
4798                         init_failed = 1;
4799         }
4800
4801         if (dev->param.is_yaffs2)
4802                 dev->param.use_header_file_size = 1;
4803
4804         if (!init_failed && !yaffs_init_blocks(dev))
4805                 init_failed = 1;
4806
4807         yaffs_init_tnodes_and_objs(dev);
4808
4809         if (!init_failed && !yaffs_create_initial_dir(dev))
4810                 init_failed = 1;
4811
4812         if (!init_failed && dev->param.is_yaffs2 &&
4813                 !dev->param.disable_summary &&
4814                 !yaffs_summary_init(dev))
4815                 init_failed = 1;
4816
4817         if (!init_failed) {
4818                 /* Now scan the flash. */
4819                 if (dev->param.is_yaffs2) {
4820                         if (yaffs2_checkpt_restore(dev)) {
4821                                 yaffs_check_obj_details_loaded(dev->root_dir);
4822                                 yaffs_trace(YAFFS_TRACE_CHECKPOINT |
4823                                         YAFFS_TRACE_MOUNT,
4824                                         "yaffs: restored from checkpoint"
4825                                         );
4826                         } else {
4827
4828                                 /* Clean up the mess caused by an aborted
4829                                  * checkpoint load then scan backwards.
4830                                  */
4831                                 yaffs_deinit_blocks(dev);
4832
4833                                 yaffs_deinit_tnodes_and_objs(dev);
4834
4835                                 dev->n_erased_blocks = 0;
4836                                 dev->n_free_chunks = 0;
4837                                 dev->alloc_block = -1;
4838                                 dev->alloc_page = -1;
4839                                 dev->n_deleted_files = 0;
4840                                 dev->n_unlinked_files = 0;
4841                                 dev->n_bg_deletions = 0;
4842
4843                                 if (!init_failed && !yaffs_init_blocks(dev))
4844                                         init_failed = 1;
4845
4846                                 yaffs_init_tnodes_and_objs(dev);
4847
4848                                 if (!init_failed
4849                                     && !yaffs_create_initial_dir(dev))
4850                                         init_failed = 1;
4851
4852                                 if (!init_failed && !yaffs2_scan_backwards(dev))
4853                                         init_failed = 1;
4854                         }
4855                 } else if (!yaffs1_scan(dev)) {
4856                         init_failed = 1;
4857                 }
4858
4859                 yaffs_strip_deleted_objs(dev);
4860                 yaffs_fix_hanging_objs(dev);
4861                 if (dev->param.empty_lost_n_found)
4862                         yaffs_empty_l_n_f(dev);
4863         }
4864
4865         if (init_failed) {
4866                 /* Clean up the mess */
4867                 yaffs_trace(YAFFS_TRACE_TRACING,
4868                   "yaffs: yaffs_guts_initialise() aborted.");
4869
4870                 yaffs_deinitialise(dev);
4871                 return YAFFS_FAIL;
4872         }
4873
4874         /* Zero out stats */
4875         dev->n_page_reads = 0;
4876         dev->n_page_writes = 0;
4877         dev->n_erasures = 0;
4878         dev->n_gc_copies = 0;
4879         dev->n_retried_writes = 0;
4880
4881         dev->n_retired_blocks = 0;
4882
4883         yaffs_verify_free_chunks(dev);
4884         yaffs_verify_blocks(dev);
4885
4886         /* Clean up any aborted checkpoint data */
4887         if (!dev->is_checkpointed && dev->blocks_in_checkpt > 0)
4888                 yaffs2_checkpt_invalidate(dev);
4889
4890         yaffs_trace(YAFFS_TRACE_TRACING,
4891           "yaffs: yaffs_guts_initialise() done.");
4892         return YAFFS_OK;
4893 }
4894
4895 void yaffs_deinitialise(struct yaffs_dev *dev)
4896 {
4897         if (dev->is_mounted) {
4898                 int i;
4899
4900                 yaffs_deinit_blocks(dev);
4901                 yaffs_deinit_tnodes_and_objs(dev);
4902                 yaffs_summary_deinit(dev);
4903
4904                 if (dev->param.n_caches > 0 && dev->cache) {
4905
4906                         for (i = 0; i < dev->param.n_caches; i++) {
4907                                 kfree(dev->cache[i].data);
4908                                 dev->cache[i].data = NULL;
4909                         }
4910
4911                         kfree(dev->cache);
4912                         dev->cache = NULL;
4913                 }
4914
4915                 kfree(dev->gc_cleanup_list);
4916
4917                 for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++)
4918                         kfree(dev->temp_buffer[i].buffer);
4919
4920                 dev->is_mounted = 0;
4921
4922                 if (dev->param.deinitialise_flash_fn)
4923                         dev->param.deinitialise_flash_fn(dev);
4924         }
4925 }
4926
4927 int yaffs_count_free_chunks(struct yaffs_dev *dev)
4928 {
4929         int n_free = 0;
4930         int b;
4931         struct yaffs_block_info *blk;
4932
4933         blk = dev->block_info;
4934         for (b = dev->internal_start_block; b <= dev->internal_end_block; b++) {
4935                 switch (blk->block_state) {
4936                 case YAFFS_BLOCK_STATE_EMPTY:
4937                 case YAFFS_BLOCK_STATE_ALLOCATING:
4938                 case YAFFS_BLOCK_STATE_COLLECTING:
4939                 case YAFFS_BLOCK_STATE_FULL:
4940                         n_free +=
4941                             (dev->param.chunks_per_block - blk->pages_in_use +
4942                              blk->soft_del_pages);
4943                         break;
4944                 default:
4945                         break;
4946                 }
4947                 blk++;
4948         }
4949         return n_free;
4950 }
4951
4952 int yaffs_get_n_free_chunks(struct yaffs_dev *dev)
4953 {
4954         /* This is what we report to the outside world */
4955         int n_free;
4956         int n_dirty_caches;
4957         int blocks_for_checkpt;
4958         int i;
4959
4960         n_free = dev->n_free_chunks;
4961         n_free += dev->n_deleted_files;
4962
4963         /* Now count and subtract the number of dirty chunks in the cache. */
4964
4965         for (n_dirty_caches = 0, i = 0; i < dev->param.n_caches; i++) {
4966                 if (dev->cache[i].dirty)
4967                         n_dirty_caches++;
4968         }
4969
4970         n_free -= n_dirty_caches;
4971
4972         n_free -=
4973             ((dev->param.n_reserved_blocks + 1) * dev->param.chunks_per_block);
4974
4975         /* Now figure checkpoint space and report that... */
4976         blocks_for_checkpt = yaffs_calc_checkpt_blocks_required(dev);
4977
4978         n_free -= (blocks_for_checkpt * dev->param.chunks_per_block);
4979
4980         if (n_free < 0)
4981                 n_free = 0;
4982
4983         return n_free;
4984 }
4985
4986 /*\
4987  * Marshalling functions to get loff_t file sizes into aand out of
4988  * object headers.
4989  */
4990 void yaffs_oh_size_load(struct yaffs_obj_hdr *oh, loff_t fsize)
4991 {
4992         oh->file_size_low = (fsize & 0xFFFFFFFF);
4993         oh->file_size_high = ((fsize >> 32) & 0xFFFFFFFF);
4994 }
4995
4996 loff_t yaffs_oh_to_size(struct yaffs_obj_hdr *oh)
4997 {
4998         loff_t retval;
4999
5000         if (~(oh->file_size_high))
5001                 retval = (((loff_t) oh->file_size_high) << 32) |
5002                         (((loff_t) oh->file_size_low) & 0xFFFFFFFF);
5003         else
5004                 retval = (loff_t) oh->file_size_low;
5005
5006         return retval;
5007 }