uboot/fs/yaffs2/yaffs_guts.c
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   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
  40static 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
  47void 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
  79static 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
 102static 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
 123static 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
 139u8 *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
 165void yaffs_release_temp_buffer(struct yaffs_dev *dev, u8 *buffer)
 166{
 167        int i;
 168
 169        dev->temp_in_use--;
 170
 171        for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
 172                if (dev->temp_buffer[i].buffer == buffer) {
 173                        dev->temp_buffer[i].in_use = 0;
 174                        return;
 175                }
 176        }
 177
 178        if (buffer) {
 179                /* assume it is an unmanaged one. */
 180                yaffs_trace(YAFFS_TRACE_BUFFERS,
 181                        "Releasing unmanaged temp buffer");
 182                kfree(buffer);
 183                dev->unmanaged_buffer_deallocs++;
 184        }
 185
 186}
 187
 188/*
 189 * Determine if we have a managed buffer.
 190 */
 191int yaffs_is_managed_tmp_buffer(struct yaffs_dev *dev, const u8 *buffer)
 192{
 193        int i;
 194
 195        for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
 196                if (dev->temp_buffer[i].buffer == buffer)
 197                        return 1;
 198        }
 199
 200        for (i = 0; i < dev->param.n_caches; i++) {
 201                if (dev->cache[i].data == buffer)
 202                        return 1;
 203        }
 204
 205        if (buffer == dev->checkpt_buffer)
 206                return 1;
 207
 208        yaffs_trace(YAFFS_TRACE_ALWAYS,
 209          "yaffs: unmaged buffer detected.");
 210        return 0;
 211}
 212
 213/*
 214 * Functions for robustisizing TODO
 215 *
 216 */
 217
 218static void yaffs_handle_chunk_wr_ok(struct yaffs_dev *dev, int nand_chunk,
 219                                     const u8 *data,
 220                                     const struct yaffs_ext_tags *tags)
 221{
 222}
 223
 224static void yaffs_handle_chunk_update(struct yaffs_dev *dev, int nand_chunk,
 225                                      const struct yaffs_ext_tags *tags)
 226{
 227}
 228
 229void yaffs_handle_chunk_error(struct yaffs_dev *dev,
 230                              struct yaffs_block_info *bi)
 231{
 232        if (!bi->gc_prioritise) {
 233                bi->gc_prioritise = 1;
 234                dev->has_pending_prioritised_gc = 1;
 235                bi->chunk_error_strikes++;
 236
 237                if (bi->chunk_error_strikes > 3) {
 238                        bi->needs_retiring = 1; /* Too many stikes, so retire */
 239                        yaffs_trace(YAFFS_TRACE_ALWAYS,
 240                                "yaffs: Block struck out");
 241
 242                }
 243        }
 244}
 245
 246static void yaffs_handle_chunk_wr_error(struct yaffs_dev *dev, int nand_chunk,
 247                                        int erased_ok)
 248{
 249        int flash_block = nand_chunk / dev->param.chunks_per_block;
 250        struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
 251
 252        yaffs_handle_chunk_error(dev, bi);
 253
 254        if (erased_ok) {
 255                /* Was an actual write failure,
 256                 * so mark the block for retirement.*/
 257                bi->needs_retiring = 1;
 258                yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
 259                  "**>> Block %d needs retiring", flash_block);
 260        }
 261
 262        /* Delete the chunk */
 263        yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
 264        yaffs_skip_rest_of_block(dev);
 265}
 266
 267/*
 268 * Verification code
 269 */
 270
 271/*
 272 *  Simple hash function. Needs to have a reasonable spread
 273 */
 274
 275static inline int yaffs_hash_fn(int n)
 276{
 277        if (n < 0)
 278                n = -n;
 279        return n % YAFFS_NOBJECT_BUCKETS;
 280}
 281
 282/*
 283 * Access functions to useful fake objects.
 284 * Note that root might have a presence in NAND if permissions are set.
 285 */
 286
 287struct yaffs_obj *yaffs_root(struct yaffs_dev *dev)
 288{
 289        return dev->root_dir;
 290}
 291
 292struct yaffs_obj *yaffs_lost_n_found(struct yaffs_dev *dev)
 293{
 294        return dev->lost_n_found;
 295}
 296
 297/*
 298 *  Erased NAND checking functions
 299 */
 300
 301int yaffs_check_ff(u8 *buffer, int n_bytes)
 302{
 303        /* Horrible, slow implementation */
 304        while (n_bytes--) {
 305                if (*buffer != 0xff)
 306                        return 0;
 307                buffer++;
 308        }
 309        return 1;
 310}
 311
 312static int yaffs_check_chunk_erased(struct yaffs_dev *dev, int nand_chunk)
 313{
 314        int retval = YAFFS_OK;
 315        u8 *data = yaffs_get_temp_buffer(dev);
 316        struct yaffs_ext_tags tags;
 317
 318        yaffs_rd_chunk_tags_nand(dev, nand_chunk, data, &tags);
 319
 320        if (tags.ecc_result > YAFFS_ECC_RESULT_NO_ERROR)
 321                retval = YAFFS_FAIL;
 322
 323        if (!yaffs_check_ff(data, dev->data_bytes_per_chunk) ||
 324                tags.chunk_used) {
 325                yaffs_trace(YAFFS_TRACE_NANDACCESS,
 326                        "Chunk %d not erased", nand_chunk);
 327                retval = YAFFS_FAIL;
 328        }
 329
 330        yaffs_release_temp_buffer(dev, data);
 331
 332        return retval;
 333
 334}
 335
 336static int yaffs_verify_chunk_written(struct yaffs_dev *dev,
 337                                      int nand_chunk,
 338                                      const u8 *data,
 339                                      struct yaffs_ext_tags *tags)
 340{
 341        int retval = YAFFS_OK;
 342        struct yaffs_ext_tags temp_tags;
 343        u8 *buffer = yaffs_get_temp_buffer(dev);
 344
 345        yaffs_rd_chunk_tags_nand(dev, nand_chunk, buffer, &temp_tags);
 346        if (memcmp(buffer, data, dev->data_bytes_per_chunk) ||
 347            temp_tags.obj_id != tags->obj_id ||
 348            temp_tags.chunk_id != tags->chunk_id ||
 349            temp_tags.n_bytes != tags->n_bytes)
 350                retval = YAFFS_FAIL;
 351
 352        yaffs_release_temp_buffer(dev, buffer);
 353
 354        return retval;
 355}
 356
 357
 358int yaffs_check_alloc_available(struct yaffs_dev *dev, int n_chunks)
 359{
 360        int reserved_chunks;
 361        int reserved_blocks = dev->param.n_reserved_blocks;
 362        int checkpt_blocks;
 363
 364        checkpt_blocks = yaffs_calc_checkpt_blocks_required(dev);
 365
 366        reserved_chunks =
 367            (reserved_blocks + checkpt_blocks) * dev->param.chunks_per_block;
 368
 369        return (dev->n_free_chunks > (reserved_chunks + n_chunks));
 370}
 371
 372static int yaffs_find_alloc_block(struct yaffs_dev *dev)
 373{
 374        int i;
 375        struct yaffs_block_info *bi;
 376
 377        if (dev->n_erased_blocks < 1) {
 378                /* Hoosterman we've got a problem.
 379                 * Can't get space to gc
 380                 */
 381                yaffs_trace(YAFFS_TRACE_ERROR,
 382                  "yaffs tragedy: no more erased blocks");
 383
 384                return -1;
 385        }
 386
 387        /* Find an empty block. */
 388
 389        for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
 390                dev->alloc_block_finder++;
 391                if (dev->alloc_block_finder < dev->internal_start_block
 392                    || dev->alloc_block_finder > dev->internal_end_block) {
 393                        dev->alloc_block_finder = dev->internal_start_block;
 394                }
 395
 396                bi = yaffs_get_block_info(dev, dev->alloc_block_finder);
 397
 398                if (bi->block_state == YAFFS_BLOCK_STATE_EMPTY) {
 399                        bi->block_state = YAFFS_BLOCK_STATE_ALLOCATING;
 400                        dev->seq_number++;
 401                        bi->seq_number = dev->seq_number;
 402                        dev->n_erased_blocks--;
 403                        yaffs_trace(YAFFS_TRACE_ALLOCATE,
 404                          "Allocated block %d, seq  %d, %d left" ,
 405                           dev->alloc_block_finder, dev->seq_number,
 406                           dev->n_erased_blocks);
 407                        return dev->alloc_block_finder;
 408                }
 409        }
 410
 411        yaffs_trace(YAFFS_TRACE_ALWAYS,
 412                "yaffs tragedy: no more erased blocks, but there should have been %d",
 413                dev->n_erased_blocks);
 414
 415        return -1;
 416}
 417
 418static int yaffs_alloc_chunk(struct yaffs_dev *dev, int use_reserver,
 419                             struct yaffs_block_info **block_ptr)
 420{
 421        int ret_val;
 422        struct yaffs_block_info *bi;
 423
 424        if (dev->alloc_block < 0) {
 425                /* Get next block to allocate off */
 426                dev->alloc_block = yaffs_find_alloc_block(dev);
 427                dev->alloc_page = 0;
 428        }
 429
 430        if (!use_reserver && !yaffs_check_alloc_available(dev, 1)) {
 431                /* No space unless we're allowed to use the reserve. */
 432                return -1;
 433        }
 434
 435        if (dev->n_erased_blocks < dev->param.n_reserved_blocks
 436            && dev->alloc_page == 0)
 437                yaffs_trace(YAFFS_TRACE_ALLOCATE, "Allocating reserve");
 438
 439        /* Next page please.... */
 440        if (dev->alloc_block >= 0) {
 441                bi = yaffs_get_block_info(dev, dev->alloc_block);
 442
 443                ret_val = (dev->alloc_block * dev->param.chunks_per_block) +
 444                    dev->alloc_page;
 445                bi->pages_in_use++;
 446                yaffs_set_chunk_bit(dev, dev->alloc_block, dev->alloc_page);
 447
 448                dev->alloc_page++;
 449
 450                dev->n_free_chunks--;
 451
 452                /* If the block is full set the state to full */
 453                if (dev->alloc_page >= dev->param.chunks_per_block) {
 454                        bi->block_state = YAFFS_BLOCK_STATE_FULL;
 455                        dev->alloc_block = -1;
 456                }
 457
 458                if (block_ptr)
 459                        *block_ptr = bi;
 460
 461                return ret_val;
 462        }
 463
 464        yaffs_trace(YAFFS_TRACE_ERROR,
 465                "!!!!!!!!! Allocator out !!!!!!!!!!!!!!!!!");
 466
 467        return -1;
 468}
 469
 470static int yaffs_get_erased_chunks(struct yaffs_dev *dev)
 471{
 472        int n;
 473
 474        n = dev->n_erased_blocks * dev->param.chunks_per_block;
 475
 476        if (dev->alloc_block > 0)
 477                n += (dev->param.chunks_per_block - dev->alloc_page);
 478
 479        return n;
 480
 481}
 482
 483/*
 484 * yaffs_skip_rest_of_block() skips over the rest of the allocation block
 485 * if we don't want to write to it.
 486 */
 487void yaffs_skip_rest_of_block(struct yaffs_dev *dev)
 488{
 489        struct yaffs_block_info *bi;
 490
 491        if (dev->alloc_block > 0) {
 492                bi = yaffs_get_block_info(dev, dev->alloc_block);
 493                if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING) {
 494                        bi->block_state = YAFFS_BLOCK_STATE_FULL;
 495                        dev->alloc_block = -1;
 496                }
 497        }
 498}
 499
 500static int yaffs_write_new_chunk(struct yaffs_dev *dev,
 501                                 const u8 *data,
 502                                 struct yaffs_ext_tags *tags, int use_reserver)
 503{
 504        int attempts = 0;
 505        int write_ok = 0;
 506        int chunk;
 507
 508        yaffs2_checkpt_invalidate(dev);
 509
 510        do {
 511                struct yaffs_block_info *bi = 0;
 512                int erased_ok = 0;
 513
 514                chunk = yaffs_alloc_chunk(dev, use_reserver, &bi);
 515                if (chunk < 0) {
 516                        /* no space */
 517                        break;
 518                }
 519
 520                /* First check this chunk is erased, if it needs
 521                 * checking.  The checking policy (unless forced
 522                 * always on) is as follows:
 523                 *
 524                 * Check the first page we try to write in a block.
 525                 * If the check passes then we don't need to check any
 526                 * more.        If the check fails, we check again...
 527                 * If the block has been erased, we don't need to check.
 528                 *
 529                 * However, if the block has been prioritised for gc,
 530                 * then we think there might be something odd about
 531                 * this block and stop using it.
 532                 *
 533                 * Rationale: We should only ever see chunks that have
 534                 * not been erased if there was a partially written
 535                 * chunk due to power loss.  This checking policy should
 536                 * catch that case with very few checks and thus save a
 537                 * lot of checks that are most likely not needed.
 538                 *
 539                 * Mods to the above
 540                 * If an erase check fails or the write fails we skip the
 541                 * rest of the block.
 542                 */
 543
 544                /* let's give it a try */
 545                attempts++;
 546
 547                if (dev->param.always_check_erased)
 548                        bi->skip_erased_check = 0;
 549
 550                if (!bi->skip_erased_check) {
 551                        erased_ok = yaffs_check_chunk_erased(dev, chunk);
 552                        if (erased_ok != YAFFS_OK) {
 553                                yaffs_trace(YAFFS_TRACE_ERROR,
 554                                  "**>> yaffs chunk %d was not erased",
 555                                  chunk);
 556
 557                                /* If not erased, delete this one,
 558                                 * skip rest of block and
 559                                 * try another chunk */
 560                                yaffs_chunk_del(dev, chunk, 1, __LINE__);
 561                                yaffs_skip_rest_of_block(dev);
 562                                continue;
 563                        }
 564                }
 565
 566                write_ok = yaffs_wr_chunk_tags_nand(dev, chunk, data, tags);
 567
 568                if (!bi->skip_erased_check)
 569                        write_ok =
 570                            yaffs_verify_chunk_written(dev, chunk, data, tags);
 571
 572                if (write_ok != YAFFS_OK) {
 573                        /* Clean up aborted write, skip to next block and
 574                         * try another chunk */
 575                        yaffs_handle_chunk_wr_error(dev, chunk, erased_ok);
 576                        continue;
 577                }
 578
 579                bi->skip_erased_check = 1;
 580
 581                /* Copy the data into the robustification buffer */
 582                yaffs_handle_chunk_wr_ok(dev, chunk, data, tags);
 583
 584        } while (write_ok != YAFFS_OK &&
 585                 (yaffs_wr_attempts <= 0 || attempts <= yaffs_wr_attempts));
 586
 587        if (!write_ok)
 588                chunk = -1;
 589
 590        if (attempts > 1) {
 591                yaffs_trace(YAFFS_TRACE_ERROR,
 592                        "**>> yaffs write required %d attempts",
 593                        attempts);
 594                dev->n_retried_writes += (attempts - 1);
 595        }
 596
 597        return chunk;
 598}
 599
 600/*
 601 * Block retiring for handling a broken block.
 602 */
 603
 604static void yaffs_retire_block(struct yaffs_dev *dev, int flash_block)
 605{
 606        struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
 607
 608        yaffs2_checkpt_invalidate(dev);
 609
 610        yaffs2_clear_oldest_dirty_seq(dev, bi);
 611
 612        if (yaffs_mark_bad(dev, flash_block) != YAFFS_OK) {
 613                if (yaffs_erase_block(dev, flash_block) != YAFFS_OK) {
 614                        yaffs_trace(YAFFS_TRACE_ALWAYS,
 615                                "yaffs: Failed to mark bad and erase block %d",
 616                                flash_block);
 617                } else {
 618                        struct yaffs_ext_tags tags;
 619                        int chunk_id =
 620                            flash_block * dev->param.chunks_per_block;
 621
 622                        u8 *buffer = yaffs_get_temp_buffer(dev);
 623
 624                        memset(buffer, 0xff, dev->data_bytes_per_chunk);
 625                        memset(&tags, 0, sizeof(tags));
 626                        tags.seq_number = YAFFS_SEQUENCE_BAD_BLOCK;
 627                        if (dev->param.write_chunk_tags_fn(dev, chunk_id -
 628                                                           dev->chunk_offset,
 629                                                           buffer,
 630                                                           &tags) != YAFFS_OK)
 631                                yaffs_trace(YAFFS_TRACE_ALWAYS,
 632                                        "yaffs: Failed to write bad block marker to block %d",
 633                                        flash_block);
 634
 635                        yaffs_release_temp_buffer(dev, buffer);
 636                }
 637        }
 638
 639        bi->block_state = YAFFS_BLOCK_STATE_DEAD;
 640        bi->gc_prioritise = 0;
 641        bi->needs_retiring = 0;
 642
 643        dev->n_retired_blocks++;
 644}
 645
 646/*---------------- Name handling functions ------------*/
 647
 648static u16 yaffs_calc_name_sum(const YCHAR *name)
 649{
 650        u16 sum = 0;
 651        u16 i = 1;
 652
 653        if (!name)
 654                return 0;
 655
 656        while ((*name) && i < (YAFFS_MAX_NAME_LENGTH / 2)) {
 657
 658                /* 0x1f mask is case insensitive */
 659                sum += ((*name) & 0x1f) * i;
 660                i++;
 661                name++;
 662        }
 663        return sum;
 664}
 665
 666void yaffs_set_obj_name(struct yaffs_obj *obj, const YCHAR * name)
 667{
 668        memset(obj->short_name, 0, sizeof(obj->short_name));
 669        if (name &&
 670                yaffs_strnlen(name, YAFFS_SHORT_NAME_LENGTH + 1) <=
 671                YAFFS_SHORT_NAME_LENGTH)
 672                yaffs_strcpy(obj->short_name, name);
 673        else
 674                obj->short_name[0] = _Y('\0');
 675        obj->sum = yaffs_calc_name_sum(name);
 676}
 677
 678void yaffs_set_obj_name_from_oh(struct yaffs_obj *obj,
 679                                const struct yaffs_obj_hdr *oh)
 680{
 681#ifdef CONFIG_YAFFS_AUTO_UNICODE
 682        YCHAR tmp_name[YAFFS_MAX_NAME_LENGTH + 1];
 683        memset(tmp_name, 0, sizeof(tmp_name));
 684        yaffs_load_name_from_oh(obj->my_dev, tmp_name, oh->name,
 685                                YAFFS_MAX_NAME_LENGTH + 1);
 686        yaffs_set_obj_name(obj, tmp_name);
 687#else
 688        yaffs_set_obj_name(obj, oh->name);
 689#endif
 690}
 691
 692loff_t yaffs_max_file_size(struct yaffs_dev *dev)
 693{
 694        return ((loff_t) YAFFS_MAX_CHUNK_ID) * dev->data_bytes_per_chunk;
 695}
 696
 697/*-------------------- TNODES -------------------
 698
 699 * List of spare tnodes
 700 * The list is hooked together using the first pointer
 701 * in the tnode.
 702 */
 703
 704struct yaffs_tnode *yaffs_get_tnode(struct yaffs_dev *dev)
 705{
 706        struct yaffs_tnode *tn = yaffs_alloc_raw_tnode(dev);
 707
 708        if (tn) {
 709                memset(tn, 0, dev->tnode_size);
 710                dev->n_tnodes++;
 711        }
 712
 713        dev->checkpoint_blocks_required = 0;    /* force recalculation */
 714
 715        return tn;
 716}
 717
 718/* FreeTnode frees up a tnode and puts it back on the free list */
 719static void yaffs_free_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
 720{
 721        yaffs_free_raw_tnode(dev, tn);
 722        dev->n_tnodes--;
 723        dev->checkpoint_blocks_required = 0;    /* force recalculation */
 724}
 725
 726static void yaffs_deinit_tnodes_and_objs(struct yaffs_dev *dev)
 727{
 728        yaffs_deinit_raw_tnodes_and_objs(dev);
 729        dev->n_obj = 0;
 730        dev->n_tnodes = 0;
 731}
 732
 733void yaffs_load_tnode_0(struct yaffs_dev *dev, struct yaffs_tnode *tn,
 734                        unsigned pos, unsigned val)
 735{
 736        u32 *map = (u32 *) tn;
 737        u32 bit_in_map;
 738        u32 bit_in_word;
 739        u32 word_in_map;
 740        u32 mask;
 741
 742        pos &= YAFFS_TNODES_LEVEL0_MASK;
 743        val >>= dev->chunk_grp_bits;
 744
 745        bit_in_map = pos * dev->tnode_width;
 746        word_in_map = bit_in_map / 32;
 747        bit_in_word = bit_in_map & (32 - 1);
 748
 749        mask = dev->tnode_mask << bit_in_word;
 750
 751        map[word_in_map] &= ~mask;
 752        map[word_in_map] |= (mask & (val << bit_in_word));
 753
 754        if (dev->tnode_width > (32 - bit_in_word)) {
 755                bit_in_word = (32 - bit_in_word);
 756                word_in_map++;
 757                mask =
 758                    dev->tnode_mask >> bit_in_word;
 759                map[word_in_map] &= ~mask;
 760                map[word_in_map] |= (mask & (val >> bit_in_word));
 761        }
 762}
 763
 764u32 yaffs_get_group_base(struct yaffs_dev *dev, struct yaffs_tnode *tn,
 765                         unsigned pos)
 766{
 767        u32 *map = (u32 *) tn;
 768        u32 bit_in_map;
 769        u32 bit_in_word;
 770        u32 word_in_map;
 771        u32 val;
 772
 773        pos &= YAFFS_TNODES_LEVEL0_MASK;
 774
 775        bit_in_map = pos * dev->tnode_width;
 776        word_in_map = bit_in_map / 32;
 777        bit_in_word = bit_in_map & (32 - 1);
 778
 779        val = map[word_in_map] >> bit_in_word;
 780
 781        if (dev->tnode_width > (32 - bit_in_word)) {
 782                bit_in_word = (32 - bit_in_word);
 783                word_in_map++;
 784                val |= (map[word_in_map] << bit_in_word);
 785        }
 786
 787        val &= dev->tnode_mask;
 788        val <<= dev->chunk_grp_bits;
 789
 790        return val;
 791}
 792
 793/* ------------------- End of individual tnode manipulation -----------------*/
 794
 795/* ---------Functions to manipulate the look-up tree (made up of tnodes) ------
 796 * The look up tree is represented by the top tnode and the number of top_level
 797 * in the tree. 0 means only the level 0 tnode is in the tree.
 798 */
 799
 800/* FindLevel0Tnode finds the level 0 tnode, if one exists. */
 801struct yaffs_tnode *yaffs_find_tnode_0(struct yaffs_dev *dev,
 802                                       struct yaffs_file_var *file_struct,
 803                                       u32 chunk_id)
 804{
 805        struct yaffs_tnode *tn = file_struct->top;
 806        u32 i;
 807        int required_depth;
 808        int level = file_struct->top_level;
 809
 810        /* Check sane level and chunk Id */
 811        if (level < 0 || level > YAFFS_TNODES_MAX_LEVEL)
 812                return NULL;
 813
 814        if (chunk_id > YAFFS_MAX_CHUNK_ID)
 815                return NULL;
 816
 817        /* First check we're tall enough (ie enough top_level) */
 818
 819        i = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
 820        required_depth = 0;
 821        while (i) {
 822                i >>= YAFFS_TNODES_INTERNAL_BITS;
 823                required_depth++;
 824        }
 825
 826        if (required_depth > file_struct->top_level)
 827                return NULL;    /* Not tall enough, so we can't find it */
 828
 829        /* Traverse down to level 0 */
 830        while (level > 0 && tn) {
 831                tn = tn->internal[(chunk_id >>
 832                                   (YAFFS_TNODES_LEVEL0_BITS +
 833                                    (level - 1) *
 834                                    YAFFS_TNODES_INTERNAL_BITS)) &
 835                                  YAFFS_TNODES_INTERNAL_MASK];
 836                level--;
 837        }
 838
 839        return tn;
 840}
 841
 842/* add_find_tnode_0 finds the level 0 tnode if it exists,
 843 * otherwise first expands the tree.
 844 * This happens in two steps:
 845 *  1. If the tree isn't tall enough, then make it taller.
 846 *  2. Scan down the tree towards the level 0 tnode adding tnodes if required.
 847 *
 848 * Used when modifying the tree.
 849 *
 850 *  If the tn argument is NULL, then a fresh tnode will be added otherwise the
 851 *  specified tn will be plugged into the ttree.
 852 */
 853
 854struct yaffs_tnode *yaffs_add_find_tnode_0(struct yaffs_dev *dev,
 855                                           struct yaffs_file_var *file_struct,
 856                                           u32 chunk_id,
 857                                           struct yaffs_tnode *passed_tn)
 858{
 859        int required_depth;
 860        int i;
 861        int l;
 862        struct yaffs_tnode *tn;
 863        u32 x;
 864
 865        /* Check sane level and page Id */
 866        if (file_struct->top_level < 0 ||
 867            file_struct->top_level > YAFFS_TNODES_MAX_LEVEL)
 868                return NULL;
 869
 870        if (chunk_id > YAFFS_MAX_CHUNK_ID)
 871                return NULL;
 872
 873        /* First check we're tall enough (ie enough top_level) */
 874
 875        x = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
 876        required_depth = 0;
 877        while (x) {
 878                x >>= YAFFS_TNODES_INTERNAL_BITS;
 879                required_depth++;
 880        }
 881
 882        if (required_depth > file_struct->top_level) {
 883                /* Not tall enough, gotta make the tree taller */
 884                for (i = file_struct->top_level; i < required_depth; i++) {
 885
 886                        tn = yaffs_get_tnode(dev);
 887
 888                        if (tn) {
 889                                tn->internal[0] = file_struct->top;
 890                                file_struct->top = tn;
 891                                file_struct->top_level++;
 892                        } else {
 893                                yaffs_trace(YAFFS_TRACE_ERROR,
 894                                        "yaffs: no more tnodes");
 895                                return NULL;
 896                        }
 897                }
 898        }
 899
 900        /* Traverse down to level 0, adding anything we need */
 901
 902        l = file_struct->top_level;
 903        tn = file_struct->top;
 904
 905        if (l > 0) {
 906                while (l > 0 && tn) {
 907                        x = (chunk_id >>
 908                             (YAFFS_TNODES_LEVEL0_BITS +
 909                              (l - 1) * YAFFS_TNODES_INTERNAL_BITS)) &
 910                            YAFFS_TNODES_INTERNAL_MASK;
 911
 912                        if ((l > 1) && !tn->internal[x]) {
 913                                /* Add missing non-level-zero tnode */
 914                                tn->internal[x] = yaffs_get_tnode(dev);
 915                                if (!tn->internal[x])
 916                                        return NULL;
 917                        } else if (l == 1) {
 918                                /* Looking from level 1 at level 0 */
 919                                if (passed_tn) {
 920                                        /* If we already have one, release it */
 921                                        if (tn->internal[x])
 922                                                yaffs_free_tnode(dev,
 923                                                        tn->internal[x]);
 924                                        tn->internal[x] = passed_tn;
 925
 926                                } else if (!tn->internal[x]) {
 927                                        /* Don't have one, none passed in */
 928                                        tn->internal[x] = yaffs_get_tnode(dev);
 929                                        if (!tn->internal[x])
 930                                                return NULL;
 931                                }
 932                        }
 933
 934                        tn = tn->internal[x];
 935                        l--;
 936                }
 937        } else {
 938                /* top is level 0 */
 939                if (passed_tn) {
 940                        memcpy(tn, passed_tn,
 941                               (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8);
 942                        yaffs_free_tnode(dev, passed_tn);
 943                }
 944        }
 945
 946        return tn;
 947}
 948
 949static int yaffs_tags_match(const struct yaffs_ext_tags *tags, int obj_id,
 950                            int chunk_obj)
 951{
 952        return (tags->chunk_id == chunk_obj &&
 953                tags->obj_id == obj_id &&
 954                !tags->is_deleted) ? 1 : 0;
 955
 956}
 957
 958static int yaffs_find_chunk_in_group(struct yaffs_dev *dev, int the_chunk,
 959                                        struct yaffs_ext_tags *tags, int obj_id,
 960                                        int inode_chunk)
 961{
 962        int j;
 963
 964        for (j = 0; the_chunk && j < dev->chunk_grp_size; j++) {
 965                if (yaffs_check_chunk_bit
 966                    (dev, the_chunk / dev->param.chunks_per_block,
 967                     the_chunk % dev->param.chunks_per_block)) {
 968
 969                        if (dev->chunk_grp_size == 1)
 970                                return the_chunk;
 971                        else {
 972                                yaffs_rd_chunk_tags_nand(dev, the_chunk, NULL,
 973                                                         tags);
 974                                if (yaffs_tags_match(tags,
 975                                                        obj_id, inode_chunk)) {
 976                                        /* found it; */
 977                                        return the_chunk;
 978                                }
 979                        }
 980                }
 981                the_chunk++;
 982        }
 983        return -1;
 984}
 985
 986static int yaffs_find_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
 987                                    struct yaffs_ext_tags *tags)
 988{
 989        /*Get the Tnode, then get the level 0 offset chunk offset */
 990        struct yaffs_tnode *tn;
 991        int the_chunk = -1;
 992        struct yaffs_ext_tags local_tags;
 993        int ret_val = -1;
 994        struct yaffs_dev *dev = in->my_dev;
 995
 996        if (!tags) {
 997                /* Passed a NULL, so use our own tags space */
 998                tags = &local_tags;
 999        }
1000
1001        tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
1002
1003        if (!tn)
1004                return ret_val;
1005
1006        the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
1007
1008        ret_val = yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
1009                                              inode_chunk);
1010        return ret_val;
1011}
1012
1013static int yaffs_find_del_file_chunk(struct yaffs_obj *in, int inode_chunk,
1014                                     struct yaffs_ext_tags *tags)
1015{
1016        /* Get the Tnode, then get the level 0 offset chunk offset */
1017        struct yaffs_tnode *tn;
1018        int the_chunk = -1;
1019        struct yaffs_ext_tags local_tags;
1020        struct yaffs_dev *dev = in->my_dev;
1021        int ret_val = -1;
1022
1023        if (!tags) {
1024                /* Passed a NULL, so use our own tags space */
1025                tags = &local_tags;
1026        }
1027
1028        tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
1029
1030        if (!tn)
1031                return ret_val;
1032
1033        the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
1034
1035        ret_val = yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
1036                                              inode_chunk);
1037
1038        /* Delete the entry in the filestructure (if found) */
1039        if (ret_val != -1)
1040                yaffs_load_tnode_0(dev, tn, inode_chunk, 0);
1041
1042        return ret_val;
1043}
1044
1045int yaffs_put_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
1046                            int nand_chunk, int in_scan)
1047{
1048        /* NB in_scan is zero unless scanning.
1049         * For forward scanning, in_scan is > 0;
1050         * for backward scanning in_scan is < 0
1051         *
1052         * nand_chunk = 0 is a dummy insert to make sure the tnodes are there.
1053         */
1054
1055        struct yaffs_tnode *tn;
1056        struct yaffs_dev *dev = in->my_dev;
1057        int existing_cunk;
1058        struct yaffs_ext_tags existing_tags;
1059        struct yaffs_ext_tags new_tags;
1060        unsigned existing_serial, new_serial;
1061
1062        if (in->variant_type != YAFFS_OBJECT_TYPE_FILE) {
1063                /* Just ignore an attempt at putting a chunk into a non-file
1064                 * during scanning.
1065                 * If it is not during Scanning then something went wrong!
1066                 */
1067                if (!in_scan) {
1068                        yaffs_trace(YAFFS_TRACE_ERROR,
1069                                "yaffs tragedy:attempt to put data chunk into a non-file"
1070                                );
1071                        BUG();
1072                }
1073
1074                yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
1075                return YAFFS_OK;
1076        }
1077
1078        tn = yaffs_add_find_tnode_0(dev,
1079                                    &in->variant.file_variant,
1080                                    inode_chunk, NULL);
1081        if (!tn)
1082                return YAFFS_FAIL;
1083
1084        if (!nand_chunk)
1085                /* Dummy insert, bail now */
1086                return YAFFS_OK;
1087
1088        existing_cunk = yaffs_get_group_base(dev, tn, inode_chunk);
1089
1090        if (in_scan != 0) {
1091                /* If we're scanning then we need to test for duplicates
1092                 * NB This does not need to be efficient since it should only
1093                 * happen when the power fails during a write, then only one
1094                 * chunk should ever be affected.
1095                 *
1096                 * Correction for YAFFS2: This could happen quite a lot and we
1097                 * need to think about efficiency! TODO
1098                 * Update: For backward scanning we don't need to re-read tags
1099                 * so this is quite cheap.
1100                 */
1101
1102                if (existing_cunk > 0) {
1103                        /* NB Right now existing chunk will not be real
1104                         * chunk_id if the chunk group size > 1
1105                         * thus we have to do a FindChunkInFile to get the
1106                         * real chunk id.
1107                         *
1108                         * We have a duplicate now we need to decide which
1109                         * one to use:
1110                         *
1111                         * Backwards scanning YAFFS2: The old one is what
1112                         * we use, dump the new one.
1113                         * YAFFS1: Get both sets of tags and compare serial
1114                         * numbers.
1115                         */
1116
1117                        if (in_scan > 0) {
1118                                /* Only do this for forward scanning */
1119                                yaffs_rd_chunk_tags_nand(dev,
1120                                                         nand_chunk,
1121                                                         NULL, &new_tags);
1122
1123                                /* Do a proper find */
1124                                existing_cunk =
1125                                    yaffs_find_chunk_in_file(in, inode_chunk,
1126                                                             &existing_tags);
1127                        }
1128
1129                        if (existing_cunk <= 0) {
1130                                /*Hoosterman - how did this happen? */
1131
1132                                yaffs_trace(YAFFS_TRACE_ERROR,
1133                                        "yaffs tragedy: existing chunk < 0 in scan"
1134                                        );
1135
1136                        }
1137
1138                        /* NB The deleted flags should be false, otherwise
1139                         * the chunks will not be loaded during a scan
1140                         */
1141
1142                        if (in_scan > 0) {
1143                                new_serial = new_tags.serial_number;
1144                                existing_serial = existing_tags.serial_number;
1145                        }
1146
1147                        if ((in_scan > 0) &&
1148                            (existing_cunk <= 0 ||
1149                             ((existing_serial + 1) & 3) == new_serial)) {
1150                                /* Forward scanning.
1151                                 * Use new
1152                                 * Delete the old one and drop through to
1153                                 * update the tnode
1154                                 */
1155                                yaffs_chunk_del(dev, existing_cunk, 1,
1156                                                __LINE__);
1157                        } else {
1158                                /* Backward scanning or we want to use the
1159                                 * existing one
1160                                 * Delete the new one and return early so that
1161                                 * the tnode isn't changed
1162                                 */
1163                                yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
1164                                return YAFFS_OK;
1165                        }
1166                }
1167
1168        }
1169
1170        if (existing_cunk == 0)
1171                in->n_data_chunks++;
1172
1173        yaffs_load_tnode_0(dev, tn, inode_chunk, nand_chunk);
1174
1175        return YAFFS_OK;
1176}
1177
1178static void yaffs_soft_del_chunk(struct yaffs_dev *dev, int chunk)
1179{
1180        struct yaffs_block_info *the_block;
1181        unsigned block_no;
1182
1183        yaffs_trace(YAFFS_TRACE_DELETION, "soft delete chunk %d", chunk);
1184
1185        block_no = chunk / dev->param.chunks_per_block;
1186        the_block = yaffs_get_block_info(dev, block_no);
1187        if (the_block) {
1188                the_block->soft_del_pages++;
1189                dev->n_free_chunks++;
1190                yaffs2_update_oldest_dirty_seq(dev, block_no, the_block);
1191        }
1192}
1193
1194/* SoftDeleteWorker scans backwards through the tnode tree and soft deletes all
1195 * the chunks in the file.
1196 * All soft deleting does is increment the block's softdelete count and pulls
1197 * the chunk out of the tnode.
1198 * Thus, essentially this is the same as DeleteWorker except that the chunks
1199 * are soft deleted.
1200 */
1201
1202static int yaffs_soft_del_worker(struct yaffs_obj *in, struct yaffs_tnode *tn,
1203                                 u32 level, int chunk_offset)
1204{
1205        int i;
1206        int the_chunk;
1207        int all_done = 1;
1208        struct yaffs_dev *dev = in->my_dev;
1209
1210        if (!tn)
1211                return 1;
1212
1213        if (level > 0) {
1214                for (i = YAFFS_NTNODES_INTERNAL - 1;
1215                        all_done && i >= 0;
1216                        i--) {
1217                        if (tn->internal[i]) {
1218                                all_done =
1219                                    yaffs_soft_del_worker(in,
1220                                        tn->internal[i],
1221                                        level - 1,
1222                                        (chunk_offset <<
1223                                        YAFFS_TNODES_INTERNAL_BITS)
1224                                        + i);
1225                                if (all_done) {
1226                                        yaffs_free_tnode(dev,
1227                                                tn->internal[i]);
1228                                        tn->internal[i] = NULL;
1229                                } else {
1230                                        /* Can this happen? */
1231                                }
1232                        }
1233                }
1234                return (all_done) ? 1 : 0;
1235        }
1236
1237        /* level 0 */
1238         for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0; i--) {
1239                the_chunk = yaffs_get_group_base(dev, tn, i);
1240                if (the_chunk) {
1241                        yaffs_soft_del_chunk(dev, the_chunk);
1242                        yaffs_load_tnode_0(dev, tn, i, 0);
1243                }
1244        }
1245        return 1;
1246}
1247
1248static void yaffs_remove_obj_from_dir(struct yaffs_obj *obj)
1249{
1250        struct yaffs_dev *dev = obj->my_dev;
1251        struct yaffs_obj *parent;
1252
1253        yaffs_verify_obj_in_dir(obj);
1254        parent = obj->parent;
1255
1256        yaffs_verify_dir(parent);
1257
1258        if (dev && dev->param.remove_obj_fn)
1259                dev->param.remove_obj_fn(obj);
1260
1261        list_del_init(&obj->siblings);
1262        obj->parent = NULL;
1263
1264        yaffs_verify_dir(parent);
1265}
1266
1267void yaffs_add_obj_to_dir(struct yaffs_obj *directory, struct yaffs_obj *obj)
1268{
1269        if (!directory) {
1270                yaffs_trace(YAFFS_TRACE_ALWAYS,
1271                        "tragedy: Trying to add an object to a null pointer directory"
1272                        );
1273                BUG();
1274                return;
1275        }
1276        if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
1277                yaffs_trace(YAFFS_TRACE_ALWAYS,
1278                        "tragedy: Trying to add an object to a non-directory"
1279                        );
1280                BUG();
1281        }
1282
1283        if (obj->siblings.prev == NULL) {
1284                /* Not initialised */
1285                BUG();
1286        }
1287
1288        yaffs_verify_dir(directory);
1289
1290        yaffs_remove_obj_from_dir(obj);
1291
1292        /* Now add it */
1293        list_add(&obj->siblings, &directory->variant.dir_variant.children);
1294        obj->parent = directory;
1295
1296        if (directory == obj->my_dev->unlinked_dir
1297            || directory == obj->my_dev->del_dir) {
1298                obj->unlinked = 1;
1299                obj->my_dev->n_unlinked_files++;
1300                obj->rename_allowed = 0;
1301        }
1302
1303        yaffs_verify_dir(directory);
1304        yaffs_verify_obj_in_dir(obj);
1305}
1306
1307static int yaffs_change_obj_name(struct yaffs_obj *obj,
1308                                 struct yaffs_obj *new_dir,
1309                                 const YCHAR *new_name, int force, int shadows)
1310{
1311        int unlink_op;
1312        int del_op;
1313        struct yaffs_obj *existing_target;
1314
1315        if (new_dir == NULL)
1316                new_dir = obj->parent;  /* use the old directory */
1317
1318        if (new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
1319                yaffs_trace(YAFFS_TRACE_ALWAYS,
1320                        "tragedy: yaffs_change_obj_name: new_dir is not a directory"
1321                        );
1322                BUG();
1323        }
1324
1325        unlink_op = (new_dir == obj->my_dev->unlinked_dir);
1326        del_op = (new_dir == obj->my_dev->del_dir);
1327
1328        existing_target = yaffs_find_by_name(new_dir, new_name);
1329
1330        /* If the object is a file going into the unlinked directory,
1331         *   then it is OK to just stuff it in since duplicate names are OK.
1332         *   else only proceed if the new name does not exist and we're putting
1333         *   it into a directory.
1334         */
1335        if (!(unlink_op || del_op || force ||
1336              shadows > 0 || !existing_target) ||
1337              new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
1338                return YAFFS_FAIL;
1339
1340        yaffs_set_obj_name(obj, new_name);
1341        obj->dirty = 1;
1342        yaffs_add_obj_to_dir(new_dir, obj);
1343
1344        if (unlink_op)
1345                obj->unlinked = 1;
1346
1347        /* If it is a deletion then we mark it as a shrink for gc  */
1348        if (yaffs_update_oh(obj, new_name, 0, del_op, shadows, NULL) >= 0)
1349                return YAFFS_OK;
1350
1351        return YAFFS_FAIL;
1352}
1353
1354/*------------------------ Short Operations Cache ------------------------------
1355 *   In many situations where there is no high level buffering  a lot of
1356 *   reads might be short sequential reads, and a lot of writes may be short
1357 *   sequential writes. eg. scanning/writing a jpeg file.
1358 *   In these cases, a short read/write cache can provide a huge perfomance
1359 *   benefit with dumb-as-a-rock code.
1360 *   In Linux, the page cache provides read buffering and the short op cache
1361 *   provides write buffering.
1362 *
1363 *   There are a small number (~10) of cache chunks per device so that we don't
1364 *   need a very intelligent search.
1365 */
1366
1367static int yaffs_obj_cache_dirty(struct yaffs_obj *obj)
1368{
1369        struct yaffs_dev *dev = obj->my_dev;
1370        int i;
1371        struct yaffs_cache *cache;
1372        int n_caches = obj->my_dev->param.n_caches;
1373
1374        for (i = 0; i < n_caches; i++) {
1375                cache = &dev->cache[i];
1376                if (cache->object == obj && cache->dirty)
1377                        return 1;
1378        }
1379
1380        return 0;
1381}
1382
1383static void yaffs_flush_file_cache(struct yaffs_obj *obj)
1384{
1385        struct yaffs_dev *dev = obj->my_dev;
1386        int lowest = -99;       /* Stop compiler whining. */
1387        int i;
1388        struct yaffs_cache *cache;
1389        int chunk_written = 0;
1390        int n_caches = obj->my_dev->param.n_caches;
1391
1392        if (n_caches < 1)
1393                return;
1394        do {
1395                cache = NULL;
1396
1397                /* Find the lowest dirty chunk for this object */
1398                for (i = 0; i < n_caches; i++) {
1399                        if (dev->cache[i].object == obj &&
1400                            dev->cache[i].dirty) {
1401                                if (!cache ||
1402                                    dev->cache[i].chunk_id < lowest) {
1403                                        cache = &dev->cache[i];
1404                                        lowest = cache->chunk_id;
1405                                }
1406                        }
1407                }
1408
1409                if (cache && !cache->locked) {
1410                        /* Write it out and free it up */
1411                        chunk_written =
1412                            yaffs_wr_data_obj(cache->object,
1413                                              cache->chunk_id,
1414                                              cache->data,
1415                                              cache->n_bytes, 1);
1416                        cache->dirty = 0;
1417                        cache->object = NULL;
1418                }
1419        } while (cache && chunk_written > 0);
1420
1421        if (cache)
1422                /* Hoosterman, disk full while writing cache out. */
1423                yaffs_trace(YAFFS_TRACE_ERROR,
1424                        "yaffs tragedy: no space during cache write");
1425}
1426
1427/*yaffs_flush_whole_cache(dev)
1428 *
1429 *
1430 */
1431
1432void yaffs_flush_whole_cache(struct yaffs_dev *dev)
1433{
1434        struct yaffs_obj *obj;
1435        int n_caches = dev->param.n_caches;
1436        int i;
1437
1438        /* Find a dirty object in the cache and flush it...
1439         * until there are no further dirty objects.
1440         */
1441        do {
1442                obj = NULL;
1443                for (i = 0; i < n_caches && !obj; i++) {
1444                        if (dev->cache[i].object && dev->cache[i].dirty)
1445                                obj = dev->cache[i].object;
1446                }
1447                if (obj)
1448                        yaffs_flush_file_cache(obj);
1449        } while (obj);
1450
1451}
1452
1453/* Grab us a cache chunk for use.
1454 * First look for an empty one.
1455 * Then look for the least recently used non-dirty one.
1456 * Then look for the least recently used dirty one...., flush and look again.
1457 */
1458static struct yaffs_cache *yaffs_grab_chunk_worker(struct yaffs_dev *dev)
1459{
1460        int i;
1461
1462        if (dev->param.n_caches > 0) {
1463                for (i = 0; i < dev->param.n_caches; i++) {
1464                        if (!dev->cache[i].object)
1465                                return &dev->cache[i];
1466                }
1467        }
1468        return NULL;
1469}
1470
1471static struct yaffs_cache *yaffs_grab_chunk_cache(struct yaffs_dev *dev)
1472{
1473        struct yaffs_cache *cache;
1474        struct yaffs_obj *the_obj;
1475        int usage;
1476        int i;
1477
1478        if (dev->param.n_caches < 1)
1479                return NULL;
1480
1481        /* Try find a non-dirty one... */
1482
1483        cache = yaffs_grab_chunk_worker(dev);
1484
1485        if (!cache) {
1486                /* They were all dirty, find the LRU object and flush
1487                 * its cache, then  find again.
1488                 * NB what's here is not very accurate,
1489                 * we actually flush the object with the LRU chunk.
1490                 */
1491
1492                /* With locking we can't assume we can use entry zero,
1493                 * Set the_obj to a valid pointer for Coverity. */
1494                the_obj = dev->cache[0].object;
1495                usage = -1;
1496                cache = NULL;
1497
1498                for (i = 0; i < dev->param.n_caches; i++) {
1499                        if (dev->cache[i].object &&
1500                            !dev->cache[i].locked &&
1501                            (dev->cache[i].last_use < usage ||
1502                            !cache)) {
1503                                usage = dev->cache[i].last_use;
1504                                the_obj = dev->cache[i].object;
1505                                cache = &dev->cache[i];
1506                        }
1507                }
1508
1509                if (!cache || cache->dirty) {
1510                        /* Flush and try again */
1511                        yaffs_flush_file_cache(the_obj);
1512                        cache = yaffs_grab_chunk_worker(dev);
1513                }
1514        }
1515        return cache;
1516}
1517
1518/* Find a cached chunk */
1519static struct yaffs_cache *yaffs_find_chunk_cache(const struct yaffs_obj *obj,
1520                                                  int chunk_id)
1521{
1522        struct yaffs_dev *dev = obj->my_dev;
1523        int i;
1524
1525        if (dev->param.n_caches < 1)
1526                return NULL;
1527
1528        for (i = 0; i < dev->param.n_caches; i++) {
1529                if (dev->cache[i].object == obj &&
1530                    dev->cache[i].chunk_id == chunk_id) {
1531                        dev->cache_hits++;
1532
1533                        return &dev->cache[i];
1534                }
1535        }
1536        return NULL;
1537}
1538
1539/* Mark the chunk for the least recently used algorithym */
1540static void yaffs_use_cache(struct yaffs_dev *dev, struct yaffs_cache *cache,
1541                            int is_write)
1542{
1543        int i;
1544
1545        if (dev->param.n_caches < 1)
1546                return;
1547
1548        if (dev->cache_last_use < 0 ||
1549                dev->cache_last_use > 100000000) {
1550                /* Reset the cache usages */
1551                for (i = 1; i < dev->param.n_caches; i++)
1552                        dev->cache[i].last_use = 0;
1553
1554                dev->cache_last_use = 0;
1555        }
1556        dev->cache_last_use++;
1557        cache->last_use = dev->cache_last_use;
1558
1559        if (is_write)
1560                cache->dirty = 1;
1561}
1562
1563/* Invalidate a single cache page.
1564 * Do this when a whole page gets written,
1565 * ie the short cache for this page is no longer valid.
1566 */
1567static void yaffs_invalidate_chunk_cache(struct yaffs_obj *object, int chunk_id)
1568{
1569        struct yaffs_cache *cache;
1570
1571        if (object->my_dev->param.n_caches > 0) {
1572                cache = yaffs_find_chunk_cache(object, chunk_id);
1573
1574                if (cache)
1575                        cache->object = NULL;
1576        }
1577}
1578
1579/* Invalidate all the cache pages associated with this object
1580 * Do this whenever ther file is deleted or resized.
1581 */
1582static void yaffs_invalidate_whole_cache(struct yaffs_obj *in)
1583{
1584        int i;
1585        struct yaffs_dev *dev = in->my_dev;
1586
1587        if (dev->param.n_caches > 0) {
1588                /* Invalidate it. */
1589                for (i = 0; i < dev->param.n_caches; i++) {
1590                        if (dev->cache[i].object == in)
1591                                dev->cache[i].object = NULL;
1592                }
1593        }
1594}
1595
1596static void yaffs_unhash_obj(struct yaffs_obj *obj)
1597{
1598        int bucket;
1599        struct yaffs_dev *dev = obj->my_dev;
1600
1601        /* If it is still linked into the bucket list, free from the list */
1602        if (!list_empty(&obj->hash_link)) {
1603                list_del_init(&obj->hash_link);
1604                bucket = yaffs_hash_fn(obj->obj_id);
1605                dev->obj_bucket[bucket].count--;
1606        }
1607}
1608
1609/*  FreeObject frees up a Object and puts it back on the free list */
1610static void yaffs_free_obj(struct yaffs_obj *obj)
1611{
1612        struct yaffs_dev *dev;
1613
1614        if (!obj) {
1615                BUG();
1616                return;
1617        }
1618        dev = obj->my_dev;
1619        yaffs_trace(YAFFS_TRACE_OS, "FreeObject %p inode %p",
1620                obj, obj->my_inode);
1621        if (obj->parent)
1622                BUG();
1623        if (!list_empty(&obj->siblings))
1624                BUG();
1625
1626        if (obj->my_inode) {
1627                /* We're still hooked up to a cached inode.
1628                 * Don't delete now, but mark for later deletion
1629                 */
1630                obj->defered_free = 1;
1631                return;
1632        }
1633
1634        yaffs_unhash_obj(obj);
1635
1636        yaffs_free_raw_obj(dev, obj);
1637        dev->n_obj--;
1638        dev->checkpoint_blocks_required = 0;    /* force recalculation */
1639}
1640
1641void yaffs_handle_defered_free(struct yaffs_obj *obj)
1642{
1643        if (obj->defered_free)
1644                yaffs_free_obj(obj);
1645}
1646
1647static int yaffs_generic_obj_del(struct yaffs_obj *in)
1648{
1649        /* Iinvalidate the file's data in the cache, without flushing. */
1650        yaffs_invalidate_whole_cache(in);
1651
1652        if (in->my_dev->param.is_yaffs2 && in->parent != in->my_dev->del_dir) {
1653                /* Move to unlinked directory so we have a deletion record */
1654                yaffs_change_obj_name(in, in->my_dev->del_dir, _Y("deleted"), 0,
1655                                      0);
1656        }
1657
1658        yaffs_remove_obj_from_dir(in);
1659        yaffs_chunk_del(in->my_dev, in->hdr_chunk, 1, __LINE__);
1660        in->hdr_chunk = 0;
1661
1662        yaffs_free_obj(in);
1663        return YAFFS_OK;
1664
1665}
1666
1667static void yaffs_soft_del_file(struct yaffs_obj *obj)
1668{
1669        if (!obj->deleted ||
1670            obj->variant_type != YAFFS_OBJECT_TYPE_FILE ||
1671            obj->soft_del)
1672                return;
1673
1674        if (obj->n_data_chunks <= 0) {
1675                /* Empty file with no duplicate object headers,
1676                 * just delete it immediately */
1677                yaffs_free_tnode(obj->my_dev, obj->variant.file_variant.top);
1678                obj->variant.file_variant.top = NULL;
1679                yaffs_trace(YAFFS_TRACE_TRACING,
1680                        "yaffs: Deleting empty file %d",
1681                        obj->obj_id);
1682                yaffs_generic_obj_del(obj);
1683        } else {
1684                yaffs_soft_del_worker(obj,
1685                                      obj->variant.file_variant.top,
1686                                      obj->variant.
1687                                      file_variant.top_level, 0);
1688                obj->soft_del = 1;
1689        }
1690}
1691
1692/* Pruning removes any part of the file structure tree that is beyond the
1693 * bounds of the file (ie that does not point to chunks).
1694 *
1695 * A file should only get pruned when its size is reduced.
1696 *
1697 * Before pruning, the chunks must be pulled from the tree and the
1698 * level 0 tnode entries must be zeroed out.
1699 * Could also use this for file deletion, but that's probably better handled
1700 * by a special case.
1701 *
1702 * This function is recursive. For levels > 0 the function is called again on
1703 * any sub-tree. For level == 0 we just check if the sub-tree has data.
1704 * If there is no data in a subtree then it is pruned.
1705 */
1706
1707static struct yaffs_tnode *yaffs_prune_worker(struct yaffs_dev *dev,
1708                                              struct yaffs_tnode *tn, u32 level,
1709                                              int del0)
1710{
1711        int i;
1712        int has_data;
1713
1714        if (!tn)
1715                return tn;
1716
1717        has_data = 0;
1718
1719        if (level > 0) {
1720                for (i = 0; i < YAFFS_NTNODES_INTERNAL; i++) {
1721                        if (tn->internal[i]) {
1722                                tn->internal[i] =
1723                                    yaffs_prune_worker(dev,
1724                                                tn->internal[i],
1725                                                level - 1,
1726                                                (i == 0) ? del0 : 1);
1727                        }
1728
1729                        if (tn->internal[i])
1730                                has_data++;
1731                }
1732        } else {
1733                int tnode_size_u32 = dev->tnode_size / sizeof(u32);
1734                u32 *map = (u32 *) tn;
1735
1736                for (i = 0; !has_data && i < tnode_size_u32; i++) {
1737                        if (map[i])
1738                                has_data++;
1739                }
1740        }
1741
1742        if (has_data == 0 && del0) {
1743                /* Free and return NULL */
1744                yaffs_free_tnode(dev, tn);
1745                tn = NULL;
1746        }
1747        return tn;
1748}
1749
1750static int yaffs_prune_tree(struct yaffs_dev *dev,
1751                            struct yaffs_file_var *file_struct)
1752{
1753        int i;
1754        int has_data;
1755        int done = 0;
1756        struct yaffs_tnode *tn;
1757
1758        if (file_struct->top_level < 1)
1759                return YAFFS_OK;
1760
1761        file_struct->top =
1762           yaffs_prune_worker(dev, file_struct->top, file_struct->top_level, 0);
1763
1764        /* Now we have a tree with all the non-zero branches NULL but
1765         * the height is the same as it was.
1766         * Let's see if we can trim internal tnodes to shorten the tree.
1767         * We can do this if only the 0th element in the tnode is in use
1768         * (ie all the non-zero are NULL)
1769         */
1770
1771        while (file_struct->top_level && !done) {
1772                tn = file_struct->top;
1773
1774                has_data = 0;
1775                for (i = 1; i < YAFFS_NTNODES_INTERNAL; i++) {
1776                        if (tn->internal[i])
1777                                has_data++;
1778                }
1779
1780                if (!has_data) {
1781                        file_struct->top = tn->internal[0];
1782                        file_struct->top_level--;
1783                        yaffs_free_tnode(dev, tn);
1784                } else {
1785                        done = 1;
1786                }
1787        }
1788
1789        return YAFFS_OK;
1790}
1791
1792/*-------------------- End of File Structure functions.-------------------*/
1793
1794/* alloc_empty_obj gets us a clean Object.*/
1795static struct yaffs_obj *yaffs_alloc_empty_obj(struct yaffs_dev *dev)
1796{
1797        struct yaffs_obj *obj = yaffs_alloc_raw_obj(dev);
1798
1799        if (!obj)
1800                return obj;
1801
1802        dev->n_obj++;
1803
1804        /* Now sweeten it up... */
1805
1806        memset(obj, 0, sizeof(struct yaffs_obj));
1807        obj->being_created = 1;
1808
1809        obj->my_dev = dev;
1810        obj->hdr_chunk = 0;
1811        obj->variant_type = YAFFS_OBJECT_TYPE_UNKNOWN;
1812        INIT_LIST_HEAD(&(obj->hard_links));
1813        INIT_LIST_HEAD(&(obj->hash_link));
1814        INIT_LIST_HEAD(&obj->siblings);
1815
1816        /* Now make the directory sane */
1817        if (dev->root_dir) {
1818                obj->parent = dev->root_dir;
1819                list_add(&(obj->siblings),
1820                         &dev->root_dir->variant.dir_variant.children);
1821        }
1822
1823        /* Add it to the lost and found directory.
1824         * NB Can't put root or lost-n-found in lost-n-found so
1825         * check if lost-n-found exists first
1826         */
1827        if (dev->lost_n_found)
1828                yaffs_add_obj_to_dir(dev->lost_n_found, obj);
1829
1830        obj->being_created = 0;
1831
1832        dev->checkpoint_blocks_required = 0;    /* force recalculation */
1833
1834        return obj;
1835}
1836
1837static int yaffs_find_nice_bucket(struct yaffs_dev *dev)
1838{
1839        int i;
1840        int l = 999;
1841        int lowest = 999999;
1842
1843        /* Search for the shortest list or one that
1844         * isn't too long.
1845         */
1846
1847        for (i = 0; i < 10 && lowest > 4; i++) {
1848                dev->bucket_finder++;
1849                dev->bucket_finder %= YAFFS_NOBJECT_BUCKETS;
1850                if (dev->obj_bucket[dev->bucket_finder].count < lowest) {
1851                        lowest = dev->obj_bucket[dev->bucket_finder].count;
1852                        l = dev->bucket_finder;
1853                }
1854        }
1855
1856        return l;
1857}
1858
1859static int yaffs_new_obj_id(struct yaffs_dev *dev)
1860{
1861        int bucket = yaffs_find_nice_bucket(dev);
1862        int found = 0;
1863        struct list_head *i;
1864        u32 n = (u32) bucket;
1865
1866        /* Now find an object value that has not already been taken
1867         * by scanning the list.
1868         */
1869
1870        while (!found) {
1871                found = 1;
1872                n += YAFFS_NOBJECT_BUCKETS;
1873                list_for_each(i, &dev->obj_bucket[bucket].list) {
1874                        /* If there is already one in the list */
1875                        if (list_entry(i, struct yaffs_obj,
1876                                       hash_link)->obj_id == n) {
1877                                found = 0;
1878                                break;
1879                        }
1880                }
1881        }
1882        return n;
1883}
1884
1885static void yaffs_hash_obj(struct yaffs_obj *in)
1886{
1887        int bucket = yaffs_hash_fn(in->obj_id);
1888        struct yaffs_dev *dev = in->my_dev;
1889
1890        list_add(&in->hash_link, &dev->obj_bucket[bucket].list);
1891        dev->obj_bucket[bucket].count++;
1892}
1893
1894struct yaffs_obj *yaffs_find_by_number(struct yaffs_dev *dev, u32 number)
1895{
1896        int bucket = yaffs_hash_fn(number);
1897        struct list_head *i;
1898        struct yaffs_obj *in;
1899
1900        list_for_each(i, &dev->obj_bucket[bucket].list) {
1901                /* Look if it is in the list */
1902                in = list_entry(i, struct yaffs_obj, hash_link);
1903                if (in->obj_id == number) {
1904                        /* Don't show if it is defered free */
1905                        if (in->defered_free)
1906                                return NULL;
1907                        return in;
1908                }
1909        }
1910
1911        return NULL;
1912}
1913
1914struct yaffs_obj *yaffs_new_obj(struct yaffs_dev *dev, int number,
1915                                enum yaffs_obj_type type)
1916{
1917        struct yaffs_obj *the_obj = NULL;
1918        struct yaffs_tnode *tn = NULL;
1919
1920        if (number < 0)
1921                number = yaffs_new_obj_id(dev);
1922
1923        if (type == YAFFS_OBJECT_TYPE_FILE) {
1924                tn = yaffs_get_tnode(dev);
1925                if (!tn)
1926                        return NULL;
1927        }
1928
1929        the_obj = yaffs_alloc_empty_obj(dev);
1930        if (!the_obj) {
1931                if (tn)
1932                        yaffs_free_tnode(dev, tn);
1933                return NULL;
1934        }
1935
1936        the_obj->fake = 0;
1937        the_obj->rename_allowed = 1;
1938        the_obj->unlink_allowed = 1;
1939        the_obj->obj_id = number;
1940        yaffs_hash_obj(the_obj);
1941        the_obj->variant_type = type;
1942        yaffs_load_current_time(the_obj, 1, 1);
1943
1944        switch (type) {
1945        case YAFFS_OBJECT_TYPE_FILE:
1946                the_obj->variant.file_variant.file_size = 0;
1947                the_obj->variant.file_variant.scanned_size = 0;
1948                the_obj->variant.file_variant.shrink_size =
1949                                                yaffs_max_file_size(dev);
1950                the_obj->variant.file_variant.top_level = 0;
1951                the_obj->variant.file_variant.top = tn;
1952                break;
1953        case YAFFS_OBJECT_TYPE_DIRECTORY:
1954                INIT_LIST_HEAD(&the_obj->variant.dir_variant.children);
1955                INIT_LIST_HEAD(&the_obj->variant.dir_variant.dirty);
1956                break;
1957        case YAFFS_OBJECT_TYPE_SYMLINK:
1958        case YAFFS_OBJECT_TYPE_HARDLINK:
1959        case YAFFS_OBJECT_TYPE_SPECIAL:
1960                /* No action required */
1961                break;
1962        case YAFFS_OBJECT_TYPE_UNKNOWN:
1963                /* todo this should not happen */
1964                break;
1965        }
1966        return the_obj;
1967}
1968
1969static struct yaffs_obj *yaffs_create_fake_dir(struct yaffs_dev *dev,
1970                                               int number, u32 mode)
1971{
1972
1973        struct yaffs_obj *obj =
1974            yaffs_new_obj(dev, number, YAFFS_OBJECT_TYPE_DIRECTORY);
1975
1976        if (!obj)
1977                return NULL;
1978
1979        obj->fake = 1;  /* it is fake so it might not use NAND */
1980        obj->rename_allowed = 0;
1981        obj->unlink_allowed = 0;
1982        obj->deleted = 0;
1983        obj->unlinked = 0;
1984        obj->yst_mode = mode;
1985        obj->my_dev = dev;
1986        obj->hdr_chunk = 0;     /* Not a valid chunk. */
1987        return obj;
1988
1989}
1990
1991
1992static void yaffs_init_tnodes_and_objs(struct yaffs_dev *dev)
1993{
1994        int i;
1995
1996        dev->n_obj = 0;
1997        dev->n_tnodes = 0;
1998        yaffs_init_raw_tnodes_and_objs(dev);
1999
2000        for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
2001                INIT_LIST_HEAD(&dev->obj_bucket[i].list);
2002                dev->obj_bucket[i].count = 0;
2003        }
2004}
2005
2006struct yaffs_obj *yaffs_find_or_create_by_number(struct yaffs_dev *dev,
2007                                                 int number,
2008                                                 enum yaffs_obj_type type)
2009{
2010        struct yaffs_obj *the_obj = NULL;
2011
2012        if (number > 0)
2013                the_obj = yaffs_find_by_number(dev, number);
2014
2015        if (!the_obj)
2016                the_obj = yaffs_new_obj(dev, number, type);
2017
2018        return the_obj;
2019
2020}
2021
2022YCHAR *yaffs_clone_str(const YCHAR *str)
2023{
2024        YCHAR *new_str = NULL;
2025        int len;
2026
2027        if (!str)
2028                str = _Y("");
2029
2030        len = yaffs_strnlen(str, YAFFS_MAX_ALIAS_LENGTH);
2031        new_str = kmalloc((len + 1) * sizeof(YCHAR), GFP_NOFS);
2032        if (new_str) {
2033                yaffs_strncpy(new_str, str, len);
2034                new_str[len] = 0;
2035        }
2036        return new_str;
2037
2038}
2039/*
2040 *yaffs_update_parent() handles fixing a directories mtime and ctime when a new
2041 * link (ie. name) is created or deleted in the directory.
2042 *
2043 * ie.
2044 *   create dir/a : update dir's mtime/ctime
2045 *   rm dir/a:   update dir's mtime/ctime
2046 *   modify dir/a: don't update dir's mtimme/ctime
2047 *
2048 * This can be handled immediately or defered. Defering helps reduce the number
2049 * of updates when many files in a directory are changed within a brief period.
2050 *
2051 * If the directory updating is defered then yaffs_update_dirty_dirs must be
2052 * called periodically.
2053 */
2054
2055static void yaffs_update_parent(struct yaffs_obj *obj)
2056{
2057        struct yaffs_dev *dev;
2058
2059        if (!obj)
2060                return;
2061        dev = obj->my_dev;
2062        obj->dirty = 1;
2063        yaffs_load_current_time(obj, 0, 1);
2064        if (dev->param.defered_dir_update) {
2065                struct list_head *link = &obj->variant.dir_variant.dirty;
2066
2067                if (list_empty(link)) {
2068                        list_add(link, &dev->dirty_dirs);
2069                        yaffs_trace(YAFFS_TRACE_BACKGROUND,
2070                          "Added object %d to dirty directories",
2071                           obj->obj_id);
2072                }
2073
2074        } else {
2075                yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
2076        }
2077}
2078
2079void yaffs_update_dirty_dirs(struct yaffs_dev *dev)
2080{
2081        struct list_head *link;
2082        struct yaffs_obj *obj;
2083        struct yaffs_dir_var *d_s;
2084        union yaffs_obj_var *o_v;
2085
2086        yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update dirty directories");
2087
2088        while (!list_empty(&dev->dirty_dirs)) {
2089                link = dev->dirty_dirs.next;
2090                list_del_init(link);
2091
2092                d_s = list_entry(link, struct yaffs_dir_var, dirty);
2093                o_v = list_entry(d_s, union yaffs_obj_var, dir_variant);
2094                obj = list_entry(o_v, struct yaffs_obj, variant);
2095
2096                yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update directory %d",
2097                        obj->obj_id);
2098
2099                if (obj->dirty)
2100                        yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
2101        }
2102}
2103
2104/*
2105 * Mknod (create) a new object.
2106 * equiv_obj only has meaning for a hard link;
2107 * alias_str only has meaning for a symlink.
2108 * rdev only has meaning for devices (a subset of special objects)
2109 */
2110
2111static struct yaffs_obj *yaffs_create_obj(enum yaffs_obj_type type,
2112                                          struct yaffs_obj *parent,
2113                                          const YCHAR *name,
2114                                          u32 mode,
2115                                          u32 uid,
2116                                          u32 gid,
2117                                          struct yaffs_obj *equiv_obj,
2118                                          const YCHAR *alias_str, u32 rdev)
2119{
2120        struct yaffs_obj *in;
2121        YCHAR *str = NULL;
2122        struct yaffs_dev *dev = parent->my_dev;
2123
2124        /* Check if the entry exists.
2125         * If it does then fail the call since we don't want a dup. */
2126        if (yaffs_find_by_name(parent, name))
2127                return NULL;
2128
2129        if (type == YAFFS_OBJECT_TYPE_SYMLINK) {
2130                str = yaffs_clone_str(alias_str);
2131                if (!str)
2132                        return NULL;
2133        }
2134
2135        in = yaffs_new_obj(dev, -1, type);
2136
2137        if (!in) {
2138                kfree(str);
2139                return NULL;
2140        }
2141
2142        in->hdr_chunk = 0;
2143        in->valid = 1;
2144        in->variant_type = type;
2145
2146        in->yst_mode = mode;
2147
2148        yaffs_attribs_init(in, gid, uid, rdev);
2149
2150        in->n_data_chunks = 0;
2151
2152        yaffs_set_obj_name(in, name);
2153        in->dirty = 1;
2154
2155        yaffs_add_obj_to_dir(parent, in);
2156
2157        in->my_dev = parent->my_dev;
2158
2159        switch (type) {
2160        case YAFFS_OBJECT_TYPE_SYMLINK:
2161                in->variant.symlink_variant.alias = str;
2162                break;
2163        case YAFFS_OBJECT_TYPE_HARDLINK:
2164                in->variant.hardlink_variant.equiv_obj = equiv_obj;
2165                in->variant.hardlink_variant.equiv_id = equiv_obj->obj_id;
2166                list_add(&in->hard_links, &equiv_obj->hard_links);
2167                break;
2168        case YAFFS_OBJECT_TYPE_FILE:
2169        case YAFFS_OBJECT_TYPE_DIRECTORY:
2170        case YAFFS_OBJECT_TYPE_SPECIAL:
2171        case YAFFS_OBJECT_TYPE_UNKNOWN:
2172                /* do nothing */
2173                break;
2174        }
2175
2176        if (yaffs_update_oh(in, name, 0, 0, 0, NULL) < 0) {
2177                /* Could not create the object header, fail */
2178                yaffs_del_obj(in);
2179                in = NULL;
2180        }
2181
2182        if (in)
2183                yaffs_update_parent(parent);
2184
2185        return in;
2186}
2187
2188struct yaffs_obj *yaffs_create_file(struct yaffs_obj *parent,
2189                                    const YCHAR *name, u32 mode, u32 uid,
2190                                    u32 gid)
2191{
2192        return yaffs_create_obj(YAFFS_OBJECT_TYPE_FILE, parent, name, mode,
2193                                uid, gid, NULL, NULL, 0);
2194}
2195
2196struct yaffs_obj *yaffs_create_dir(struct yaffs_obj *parent, const YCHAR *name,
2197                                   u32 mode, u32 uid, u32 gid)
2198{
2199        return yaffs_create_obj(YAFFS_OBJECT_TYPE_DIRECTORY, parent, name,
2200                                mode, uid, gid, NULL, NULL, 0);
2201}
2202
2203struct yaffs_obj *yaffs_create_special(struct yaffs_obj *parent,
2204                                       const YCHAR *name, u32 mode, u32 uid,
2205                                       u32 gid, u32 rdev)
2206{
2207        return yaffs_create_obj(YAFFS_OBJECT_TYPE_SPECIAL, parent, name, mode,
2208                                uid, gid, NULL, NULL, rdev);
2209}
2210
2211struct yaffs_obj *yaffs_create_symlink(struct yaffs_obj *parent,
2212                                       const YCHAR *name, u32 mode, u32 uid,
2213                                       u32 gid, const YCHAR *alias)
2214{
2215        return yaffs_create_obj(YAFFS_OBJECT_TYPE_SYMLINK, parent, name, mode,
2216                                uid, gid, NULL, alias, 0);
2217}
2218
2219/* yaffs_link_obj returns the object id of the equivalent object.*/
2220struct yaffs_obj *yaffs_link_obj(struct yaffs_obj *parent, const YCHAR * name,
2221                                 struct yaffs_obj *equiv_obj)
2222{
2223        /* Get the real object in case we were fed a hard link obj */
2224        equiv_obj = yaffs_get_equivalent_obj(equiv_obj);
2225
2226        if (yaffs_create_obj(YAFFS_OBJECT_TYPE_HARDLINK,
2227                        parent, name, 0, 0, 0,
2228                        equiv_obj, NULL, 0))
2229                return equiv_obj;
2230
2231        return NULL;
2232
2233}
2234
2235
2236
2237/*---------------------- Block Management and Page Allocation -------------*/
2238
2239static void yaffs_deinit_blocks(struct yaffs_dev *dev)
2240{
2241        if (dev->block_info_alt && dev->block_info)
2242                vfree(dev->block_info);
2243        else
2244                kfree(dev->block_info);
2245
2246        dev->block_info_alt = 0;
2247
2248        dev->block_info = NULL;
2249
2250        if (dev->chunk_bits_alt && dev->chunk_bits)
2251                vfree(dev->chunk_bits);
2252        else
2253                kfree(dev->chunk_bits);
2254        dev->chunk_bits_alt = 0;
2255        dev->chunk_bits = NULL;
2256}
2257
2258static int yaffs_init_blocks(struct yaffs_dev *dev)
2259{
2260        int n_blocks = dev->internal_end_block - dev->internal_start_block + 1;
2261
2262        dev->block_info = NULL;
2263        dev->chunk_bits = NULL;
2264        dev->alloc_block = -1;  /* force it to get a new one */
2265
2266        /* If the first allocation strategy fails, thry the alternate one */
2267        dev->block_info =
2268                kmalloc(n_blocks * sizeof(struct yaffs_block_info), GFP_NOFS);
2269        if (!dev->block_info) {
2270                dev->block_info =
2271                    vmalloc(n_blocks * sizeof(struct yaffs_block_info));
2272                dev->block_info_alt = 1;
2273        } else {
2274                dev->block_info_alt = 0;
2275        }
2276
2277        if (!dev->block_info)
2278                goto alloc_error;
2279
2280        /* Set up dynamic blockinfo stuff. Round up bytes. */
2281        dev->chunk_bit_stride = (dev->param.chunks_per_block + 7) / 8;
2282        dev->chunk_bits =
2283                kmalloc(dev->chunk_bit_stride * n_blocks, GFP_NOFS);
2284        if (!dev->chunk_bits) {
2285                dev->chunk_bits =
2286                    vmalloc(dev->chunk_bit_stride * n_blocks);
2287                dev->chunk_bits_alt = 1;
2288        } else {
2289                dev->chunk_bits_alt = 0;
2290        }
2291        if (!dev->chunk_bits)
2292                goto alloc_error;
2293
2294
2295        memset(dev->block_info, 0, n_blocks * sizeof(struct yaffs_block_info));
2296        memset(dev->chunk_bits, 0, dev->chunk_bit_stride * n_blocks);
2297        return YAFFS_OK;
2298
2299alloc_error:
2300        yaffs_deinit_blocks(dev);
2301        return YAFFS_FAIL;
2302}
2303
2304
2305void yaffs_block_became_dirty(struct yaffs_dev *dev, int block_no)
2306{
2307        struct yaffs_block_info *bi = yaffs_get_block_info(dev, block_no);
2308        int erased_ok = 0;
2309        int i;
2310
2311        /* If the block is still healthy erase it and mark as clean.
2312         * If the block has had a data failure, then retire it.
2313         */
2314
2315        yaffs_trace(YAFFS_TRACE_GC | YAFFS_TRACE_ERASE,
2316                "yaffs_block_became_dirty block %d state %d %s",
2317                block_no, bi->block_state,
2318                (bi->needs_retiring) ? "needs retiring" : "");
2319
2320        yaffs2_clear_oldest_dirty_seq(dev, bi);
2321
2322        bi->block_state = YAFFS_BLOCK_STATE_DIRTY;
2323
2324        /* If this is the block being garbage collected then stop gc'ing */
2325        if (block_no == dev->gc_block)
2326                dev->gc_block = 0;
2327
2328        /* If this block is currently the best candidate for gc
2329         * then drop as a candidate */
2330        if (block_no == dev->gc_dirtiest) {
2331                dev->gc_dirtiest = 0;
2332                dev->gc_pages_in_use = 0;
2333        }
2334
2335        if (!bi->needs_retiring) {
2336                yaffs2_checkpt_invalidate(dev);
2337                erased_ok = yaffs_erase_block(dev, block_no);
2338                if (!erased_ok) {
2339                        dev->n_erase_failures++;
2340                        yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2341                          "**>> Erasure failed %d", block_no);
2342                }
2343        }
2344
2345        /* Verify erasure if needed */
2346        if (erased_ok &&
2347            ((yaffs_trace_mask & YAFFS_TRACE_ERASE) ||
2348             !yaffs_skip_verification(dev))) {
2349                for (i = 0; i < dev->param.chunks_per_block; i++) {
2350                        if (!yaffs_check_chunk_erased(dev,
2351                                block_no * dev->param.chunks_per_block + i)) {
2352                                yaffs_trace(YAFFS_TRACE_ERROR,
2353                                        ">>Block %d erasure supposedly OK, but chunk %d not erased",
2354                                        block_no, i);
2355                        }
2356                }
2357        }
2358
2359        if (!erased_ok) {
2360                /* We lost a block of free space */
2361                dev->n_free_chunks -= dev->param.chunks_per_block;
2362                yaffs_retire_block(dev, block_no);
2363                yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
2364                        "**>> Block %d retired", block_no);
2365                return;
2366        }
2367
2368        /* Clean it up... */
2369        bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
2370        bi->seq_number = 0;
2371        dev->n_erased_blocks++;
2372        bi->pages_in_use = 0;
2373        bi->soft_del_pages = 0;
2374        bi->has_shrink_hdr = 0;
2375        bi->skip_erased_check = 1;      /* Clean, so no need to check */
2376        bi->gc_prioritise = 0;
2377        bi->has_summary = 0;
2378
2379        yaffs_clear_chunk_bits(dev, block_no);
2380
2381        yaffs_trace(YAFFS_TRACE_ERASE, "Erased block %d", block_no);
2382}
2383
2384static inline int yaffs_gc_process_chunk(struct yaffs_dev *dev,
2385                                        struct yaffs_block_info *bi,
2386                                        int old_chunk, u8 *buffer)
2387{
2388        int new_chunk;
2389        int mark_flash = 1;
2390        struct yaffs_ext_tags tags;
2391        struct yaffs_obj *object;
2392        int matching_chunk;
2393        int ret_val = YAFFS_OK;
2394
2395        memset(&tags, 0, sizeof(tags));
2396        yaffs_rd_chunk_tags_nand(dev, old_chunk,
2397                                 buffer, &tags);
2398        object = yaffs_find_by_number(dev, tags.obj_id);
2399
2400        yaffs_trace(YAFFS_TRACE_GC_DETAIL,
2401                "Collecting chunk in block %d, %d %d %d ",
2402                dev->gc_chunk, tags.obj_id,
2403                tags.chunk_id, tags.n_bytes);
2404
2405        if (object && !yaffs_skip_verification(dev)) {
2406                if (tags.chunk_id == 0)
2407                        matching_chunk =
2408                            object->hdr_chunk;
2409                else if (object->soft_del)
2410                        /* Defeat the test */
2411                        matching_chunk = old_chunk;
2412                else
2413                        matching_chunk =
2414                            yaffs_find_chunk_in_file
2415                            (object, tags.chunk_id,
2416                             NULL);
2417
2418                if (old_chunk != matching_chunk)
2419                        yaffs_trace(YAFFS_TRACE_ERROR,
2420                                "gc: page in gc mismatch: %d %d %d %d",
2421                                old_chunk,
2422                                matching_chunk,
2423                                tags.obj_id,
2424                                tags.chunk_id);
2425        }
2426
2427        if (!object) {
2428                yaffs_trace(YAFFS_TRACE_ERROR,
2429                        "page %d in gc has no object: %d %d %d ",
2430                        old_chunk,
2431                        tags.obj_id, tags.chunk_id,
2432                        tags.n_bytes);
2433        }
2434
2435        if (object &&
2436            object->deleted &&
2437            object->soft_del && tags.chunk_id != 0) {
2438                /* Data chunk in a soft deleted file,
2439                 * throw it away.
2440                 * It's a soft deleted data chunk,
2441                 * No need to copy this, just forget
2442                 * about it and fix up the object.
2443                 */
2444
2445                /* Free chunks already includes
2446                 * softdeleted chunks, how ever this
2447                 * chunk is going to soon be really
2448                 * deleted which will increment free
2449                 * chunks. We have to decrement free
2450                 * chunks so this works out properly.
2451                 */
2452                dev->n_free_chunks--;
2453                bi->soft_del_pages--;
2454
2455                object->n_data_chunks--;
2456                if (object->n_data_chunks <= 0) {
2457                        /* remeber to clean up obj */
2458                        dev->gc_cleanup_list[dev->n_clean_ups] = tags.obj_id;
2459                        dev->n_clean_ups++;
2460                }
2461                mark_flash = 0;
2462        } else if (object) {
2463                /* It's either a data chunk in a live
2464                 * file or an ObjectHeader, so we're
2465                 * interested in it.
2466                 * NB Need to keep the ObjectHeaders of
2467                 * deleted files until the whole file
2468                 * has been deleted off
2469                 */
2470                tags.serial_number++;
2471                dev->n_gc_copies++;
2472
2473                if (tags.chunk_id == 0) {
2474                        /* It is an object Id,
2475                         * We need to nuke the
2476                         * shrinkheader flags since its
2477                         * work is done.
2478                         * Also need to clean up
2479                         * shadowing.
2480                         */
2481                        struct yaffs_obj_hdr *oh;
2482                        oh = (struct yaffs_obj_hdr *) buffer;
2483
2484                        oh->is_shrink = 0;
2485                        tags.extra_is_shrink = 0;
2486                        oh->shadows_obj = 0;
2487                        oh->inband_shadowed_obj_id = 0;
2488                        tags.extra_shadows = 0;
2489
2490                        /* Update file size */
2491                        if (object->variant_type == YAFFS_OBJECT_TYPE_FILE) {
2492                                yaffs_oh_size_load(oh,
2493                                    object->variant.file_variant.file_size);
2494                                tags.extra_file_size =
2495                                    object->variant.file_variant.file_size;
2496                        }
2497
2498                        yaffs_verify_oh(object, oh, &tags, 1);
2499                        new_chunk =
2500                            yaffs_write_new_chunk(dev, (u8 *) oh, &tags, 1);
2501                } else {
2502                        new_chunk =
2503                            yaffs_write_new_chunk(dev, buffer, &tags, 1);
2504                }
2505
2506                if (new_chunk < 0) {
2507                        ret_val = YAFFS_FAIL;
2508                } else {
2509
2510                        /* Now fix up the Tnodes etc. */
2511
2512                        if (tags.chunk_id == 0) {
2513                                /* It's a header */
2514                                object->hdr_chunk = new_chunk;
2515                                object->serial = tags.serial_number;
2516                        } else {
2517                                /* It's a data chunk */
2518                                yaffs_put_chunk_in_file(object, tags.chunk_id,
2519                                                        new_chunk, 0);
2520                        }
2521                }
2522        }
2523        if (ret_val == YAFFS_OK)
2524                yaffs_chunk_del(dev, old_chunk, mark_flash, __LINE__);
2525        return ret_val;
2526}
2527
2528static int yaffs_gc_block(struct yaffs_dev *dev, int block, int whole_block)
2529{
2530        int old_chunk;
2531        int ret_val = YAFFS_OK;
2532        int i;
2533        int is_checkpt_block;
2534        int max_copies;
2535        int chunks_before = yaffs_get_erased_chunks(dev);
2536        int chunks_after;
2537        struct yaffs_block_info *bi = yaffs_get_block_info(dev, block);
2538
2539        is_checkpt_block = (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT);
2540
2541        yaffs_trace(YAFFS_TRACE_TRACING,
2542                "Collecting block %d, in use %d, shrink %d, whole_block %d",
2543                block, bi->pages_in_use, bi->has_shrink_hdr,
2544                whole_block);
2545
2546        /*yaffs_verify_free_chunks(dev); */
2547
2548        if (bi->block_state == YAFFS_BLOCK_STATE_FULL)
2549                bi->block_state = YAFFS_BLOCK_STATE_COLLECTING;
2550
2551        bi->has_shrink_hdr = 0; /* clear the flag so that the block can erase */
2552
2553        dev->gc_disable = 1;
2554
2555        yaffs_summary_gc(dev, block);
2556
2557        if (is_checkpt_block || !yaffs_still_some_chunks(dev, block)) {
2558                yaffs_trace(YAFFS_TRACE_TRACING,
2559                        "Collecting block %d that has no chunks in use",
2560                        block);
2561                yaffs_block_became_dirty(dev, block);
2562        } else {
2563
2564                u8 *buffer = yaffs_get_temp_buffer(dev);
2565
2566                yaffs_verify_blk(dev, bi, block);
2567
2568                max_copies = (whole_block) ? dev->param.chunks_per_block : 5;
2569                old_chunk = block * dev->param.chunks_per_block + dev->gc_chunk;
2570
2571                for (/* init already done */ ;
2572                     ret_val == YAFFS_OK &&
2573                     dev->gc_chunk < dev->param.chunks_per_block &&
2574                     (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) &&
2575                     max_copies > 0;
2576                     dev->gc_chunk++, old_chunk++) {
2577                        if (yaffs_check_chunk_bit(dev, block, dev->gc_chunk)) {
2578                                /* Page is in use and might need to be copied */
2579                                max_copies--;
2580                                ret_val = yaffs_gc_process_chunk(dev, bi,
2581                                                        old_chunk, buffer);
2582                        }
2583                }
2584                yaffs_release_temp_buffer(dev, buffer);
2585        }
2586
2587        yaffs_verify_collected_blk(dev, bi, block);
2588
2589        if (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
2590                /*
2591                 * The gc did not complete. Set block state back to FULL
2592                 * because checkpointing does not restore gc.
2593                 */
2594                bi->block_state = YAFFS_BLOCK_STATE_FULL;
2595        } else {
2596                /* The gc completed. */
2597                /* Do any required cleanups */
2598                for (i = 0; i < dev->n_clean_ups; i++) {
2599                        /* Time to delete the file too */
2600                        struct yaffs_obj *object =
2601                            yaffs_find_by_number(dev, dev->gc_cleanup_list[i]);
2602                        if (object) {
2603                                yaffs_free_tnode(dev,
2604                                          object->variant.file_variant.top);
2605                                object->variant.file_variant.top = NULL;
2606                                yaffs_trace(YAFFS_TRACE_GC,
2607                                        "yaffs: About to finally delete object %d",
2608                                        object->obj_id);
2609                                yaffs_generic_obj_del(object);
2610                                object->my_dev->n_deleted_files--;
2611                        }
2612
2613                }
2614                chunks_after = yaffs_get_erased_chunks(dev);
2615                if (chunks_before >= chunks_after)
2616                        yaffs_trace(YAFFS_TRACE_GC,
2617                                "gc did not increase free chunks before %d after %d",
2618                                chunks_before, chunks_after);
2619                dev->gc_block = 0;
2620                dev->gc_chunk = 0;
2621                dev->n_clean_ups = 0;
2622        }
2623
2624        dev->gc_disable = 0;
2625
2626        return ret_val;
2627}
2628
2629/*
2630 * find_gc_block() selects the dirtiest block (or close enough)
2631 * for garbage collection.
2632 */
2633
2634static unsigned yaffs_find_gc_block(struct yaffs_dev *dev,
2635                                    int aggressive, int background)
2636{
2637        int i;
2638        int iterations;
2639        unsigned selected = 0;
2640        int prioritised = 0;
2641        int prioritised_exist = 0;
2642        struct yaffs_block_info *bi;
2643        int threshold;
2644
2645        /* First let's see if we need to grab a prioritised block */
2646        if (dev->has_pending_prioritised_gc && !aggressive) {
2647                dev->gc_dirtiest = 0;
2648                bi = dev->block_info;
2649                for (i = dev->internal_start_block;
2650                     i <= dev->internal_end_block && !selected; i++) {
2651
2652                        if (bi->gc_prioritise) {
2653                                prioritised_exist = 1;
2654                                if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
2655                                    yaffs_block_ok_for_gc(dev, bi)) {
2656                                        selected = i;
2657                                        prioritised = 1;
2658                                }
2659                        }
2660                        bi++;
2661                }
2662
2663                /*
2664                 * If there is a prioritised block and none was selected then
2665                 * this happened because there is at least one old dirty block
2666                 * gumming up the works. Let's gc the oldest dirty block.
2667                 */
2668
2669                if (prioritised_exist &&
2670                    !selected && dev->oldest_dirty_block > 0)
2671                        selected = dev->oldest_dirty_block;
2672
2673                if (!prioritised_exist) /* None found, so we can clear this */
2674                        dev->has_pending_prioritised_gc = 0;
2675        }
2676
2677        /* If we're doing aggressive GC then we are happy to take a less-dirty
2678         * block, and search harder.
2679         * else (leasurely gc), then we only bother to do this if the
2680         * block has only a few pages in use.
2681         */
2682
2683        if (!selected) {
2684                int pages_used;
2685                int n_blocks =
2686                    dev->internal_end_block - dev->internal_start_block + 1;
2687                if (aggressive) {
2688                        threshold = dev->param.chunks_per_block;
2689                        iterations = n_blocks;
2690                } else {
2691                        int max_threshold;
2692
2693                        if (background)
2694                                max_threshold = dev->param.chunks_per_block / 2;
2695                        else
2696                                max_threshold = dev->param.chunks_per_block / 8;
2697
2698                        if (max_threshold < YAFFS_GC_PASSIVE_THRESHOLD)
2699                                max_threshold = YAFFS_GC_PASSIVE_THRESHOLD;
2700
2701                        threshold = background ? (dev->gc_not_done + 2) * 2 : 0;
2702                        if (threshold < YAFFS_GC_PASSIVE_THRESHOLD)
2703                                threshold = YAFFS_GC_PASSIVE_THRESHOLD;
2704                        if (threshold > max_threshold)
2705                                threshold = max_threshold;
2706
2707                        iterations = n_blocks / 16 + 1;
2708                        if (iterations > 100)
2709                                iterations = 100;
2710                }
2711
2712                for (i = 0;
2713                     i < iterations &&
2714                     (dev->gc_dirtiest < 1 ||
2715                      dev->gc_pages_in_use > YAFFS_GC_GOOD_ENOUGH);
2716                     i++) {
2717                        dev->gc_block_finder++;
2718                        if (dev->gc_block_finder < dev->internal_start_block ||
2719                            dev->gc_block_finder > dev->internal_end_block)
2720                                dev->gc_block_finder =
2721                                    dev->internal_start_block;
2722
2723                        bi = yaffs_get_block_info(dev, dev->gc_block_finder);
2724
2725                        pages_used = bi->pages_in_use - bi->soft_del_pages;
2726
2727                        if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
2728                            pages_used < dev->param.chunks_per_block &&
2729                            (dev->gc_dirtiest < 1 ||
2730                             pages_used < dev->gc_pages_in_use) &&
2731                            yaffs_block_ok_for_gc(dev, bi)) {
2732                                dev->gc_dirtiest = dev->gc_block_finder;
2733                                dev->gc_pages_in_use = pages_used;
2734                        }
2735                }
2736
2737                if (dev->gc_dirtiest > 0 && dev->gc_pages_in_use <= threshold)
2738                        selected = dev->gc_dirtiest;
2739        }
2740
2741        /*
2742         * If nothing has been selected for a while, try the oldest dirty
2743         * because that's gumming up the works.
2744         */
2745
2746        if (!selected && dev->param.is_yaffs2 &&
2747            dev->gc_not_done >= (background ? 10 : 20)) {
2748                yaffs2_find_oldest_dirty_seq(dev);
2749                if (dev->oldest_dirty_block > 0) {
2750                        selected = dev->oldest_dirty_block;
2751                        dev->gc_dirtiest = selected;
2752                        dev->oldest_dirty_gc_count++;
2753                        bi = yaffs_get_block_info(dev, selected);
2754                        dev->gc_pages_in_use =
2755                            bi->pages_in_use - bi->soft_del_pages;
2756                } else {
2757                        dev->gc_not_done = 0;
2758                }
2759        }
2760
2761        if (selected) {
2762                yaffs_trace(YAFFS_TRACE_GC,
2763                        "GC Selected block %d with %d free, prioritised:%d",
2764                        selected,
2765                        dev->param.chunks_per_block - dev->gc_pages_in_use,
2766                        prioritised);
2767
2768                dev->n_gc_blocks++;
2769                if (background)
2770                        dev->bg_gcs++;
2771
2772                dev->gc_dirtiest = 0;
2773                dev->gc_pages_in_use = 0;
2774                dev->gc_not_done = 0;
2775                if (dev->refresh_skip > 0)
2776                        dev->refresh_skip--;
2777        } else {
2778                dev->gc_not_done++;
2779                yaffs_trace(YAFFS_TRACE_GC,
2780                        "GC none: finder %d skip %d threshold %d dirtiest %d using %d oldest %d%s",
2781                        dev->gc_block_finder, dev->gc_not_done, threshold,
2782                        dev->gc_dirtiest, dev->gc_pages_in_use,
2783                        dev->oldest_dirty_block, background ? " bg" : "");
2784        }
2785
2786        return selected;
2787}
2788
2789/* New garbage collector
2790 * If we're very low on erased blocks then we do aggressive garbage collection
2791 * otherwise we do "leasurely" garbage collection.
2792 * Aggressive gc looks further (whole array) and will accept less dirty blocks.
2793 * Passive gc only inspects smaller areas and only accepts more dirty blocks.
2794 *
2795 * The idea is to help clear out space in a more spread-out manner.
2796 * Dunno if it really does anything useful.
2797 */
2798static int yaffs_check_gc(struct yaffs_dev *dev, int background)
2799{
2800        int aggressive = 0;
2801        int gc_ok = YAFFS_OK;
2802        int max_tries = 0;
2803        int min_erased;
2804        int erased_chunks;
2805        int checkpt_block_adjust;
2806
2807        if (dev->param.gc_control && (dev->param.gc_control(dev) & 1) == 0)
2808                return YAFFS_OK;
2809
2810        if (dev->gc_disable)
2811                /* Bail out so we don't get recursive gc */
2812                return YAFFS_OK;
2813
2814        /* This loop should pass the first time.
2815         * Only loops here if the collection does not increase space.
2816         */
2817
2818        do {
2819                max_tries++;
2820
2821                checkpt_block_adjust = yaffs_calc_checkpt_blocks_required(dev);
2822
2823                min_erased =
2824                    dev->param.n_reserved_blocks + checkpt_block_adjust + 1;
2825                erased_chunks =
2826                    dev->n_erased_blocks * dev->param.chunks_per_block;
2827
2828                /* If we need a block soon then do aggressive gc. */
2829                if (dev->n_erased_blocks < min_erased)
2830                        aggressive = 1;
2831                else {
2832                        if (!background
2833                            && erased_chunks > (dev->n_free_chunks / 4))
2834                                break;
2835
2836                        if (dev->gc_skip > 20)
2837                                dev->gc_skip = 20;
2838                        if (erased_chunks < dev->n_free_chunks / 2 ||
2839                            dev->gc_skip < 1 || background)
2840                                aggressive = 0;
2841                        else {
2842                                dev->gc_skip--;
2843                                break;
2844                        }
2845                }
2846
2847                dev->gc_skip = 5;
2848
2849                /* If we don't already have a block being gc'd then see if we
2850                 * should start another */
2851
2852                if (dev->gc_block < 1 && !aggressive) {
2853                        dev->gc_block = yaffs2_find_refresh_block(dev);
2854                        dev->gc_chunk = 0;
2855                        dev->n_clean_ups = 0;
2856                }
2857                if (dev->gc_block < 1) {
2858                        dev->gc_block =
2859                            yaffs_find_gc_block(dev, aggressive, background);
2860                        dev->gc_chunk = 0;
2861                        dev->n_clean_ups = 0;
2862                }
2863
2864                if (dev->gc_block > 0) {
2865                        dev->all_gcs++;
2866                        if (!aggressive)
2867                                dev->passive_gc_count++;
2868
2869                        yaffs_trace(YAFFS_TRACE_GC,
2870                                "yaffs: GC n_erased_blocks %d aggressive %d",
2871                                dev->n_erased_blocks, aggressive);
2872
2873                        gc_ok = yaffs_gc_block(dev, dev->gc_block, aggressive);
2874                }
2875
2876                if (dev->n_erased_blocks < (dev->param.n_reserved_blocks) &&
2877                    dev->gc_block > 0) {
2878                        yaffs_trace(YAFFS_TRACE_GC,
2879                                "yaffs: GC !!!no reclaim!!! n_erased_blocks %d after try %d block %d",
2880                                dev->n_erased_blocks, max_tries,
2881                                dev->gc_block);
2882                }
2883        } while ((dev->n_erased_blocks < dev->param.n_reserved_blocks) &&
2884                 (dev->gc_block > 0) && (max_tries < 2));
2885
2886        return aggressive ? gc_ok : YAFFS_OK;
2887}
2888
2889/*
2890 * yaffs_bg_gc()
2891 * Garbage collects. Intended to be called from a background thread.
2892 * Returns non-zero if at least half the free chunks are erased.
2893 */
2894int yaffs_bg_gc(struct yaffs_dev *dev, unsigned urgency)
2895{
2896        int erased_chunks = dev->n_erased_blocks * dev->param.chunks_per_block;
2897
2898        yaffs_trace(YAFFS_TRACE_BACKGROUND, "Background gc %u", urgency);
2899
2900        yaffs_check_gc(dev, 1);
2901        return erased_chunks > dev->n_free_chunks / 2;
2902}
2903
2904/*-------------------- Data file manipulation -----------------*/
2905
2906static int yaffs_rd_data_obj(struct yaffs_obj *in, int inode_chunk, u8 * buffer)
2907{
2908        int nand_chunk = yaffs_find_chunk_in_file(in, inode_chunk, NULL);
2909
2910        if (nand_chunk >= 0)
2911                return yaffs_rd_chunk_tags_nand(in->my_dev, nand_chunk,
2912                                                buffer, NULL);
2913        else {
2914                yaffs_trace(YAFFS_TRACE_NANDACCESS,
2915                        "Chunk %d not found zero instead",
2916                        nand_chunk);
2917                /* get sane (zero) data if you read a hole */
2918                memset(buffer, 0, in->my_dev->data_bytes_per_chunk);
2919                return 0;
2920        }
2921
2922}
2923
2924void yaffs_chunk_del(struct yaffs_dev *dev, int chunk_id, int mark_flash,
2925                     int lyn)
2926{
2927        int block;
2928        int page;
2929        struct yaffs_ext_tags tags;
2930        struct yaffs_block_info *bi;
2931
2932        if (chunk_id <= 0)
2933                return;
2934
2935        dev->n_deletions++;
2936        block = chunk_id / dev->param.chunks_per_block;
2937        page = chunk_id % dev->param.chunks_per_block;
2938
2939        if (!yaffs_check_chunk_bit(dev, block, page))
2940                yaffs_trace(YAFFS_TRACE_VERIFY,
2941                        "Deleting invalid chunk %d", chunk_id);
2942
2943        bi = yaffs_get_block_info(dev, block);
2944
2945        yaffs2_update_oldest_dirty_seq(dev, block, bi);
2946
2947        yaffs_trace(YAFFS_TRACE_DELETION,
2948                "line %d delete of chunk %d",
2949                lyn, chunk_id);
2950
2951        if (!dev->param.is_yaffs2 && mark_flash &&
2952            bi->block_state != YAFFS_BLOCK_STATE_COLLECTING) {
2953
2954                memset(&tags, 0, sizeof(tags));
2955                tags.is_deleted = 1;
2956                yaffs_wr_chunk_tags_nand(dev, chunk_id, NULL, &tags);
2957                yaffs_handle_chunk_update(dev, chunk_id, &tags);
2958        } else {
2959                dev->n_unmarked_deletions++;
2960        }
2961
2962        /* Pull out of the management area.
2963         * If the whole block became dirty, this will kick off an erasure.
2964         */
2965        if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING ||
2966            bi->block_state == YAFFS_BLOCK_STATE_FULL ||
2967            bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCAN ||
2968            bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
2969                dev->n_free_chunks++;
2970                yaffs_clear_chunk_bit(dev, block, page);
2971                bi->pages_in_use--;
2972
2973                if (bi->pages_in_use == 0 &&
2974                    !bi->has_shrink_hdr &&
2975                    bi->block_state != YAFFS_BLOCK_STATE_ALLOCATING &&
2976                    bi->block_state != YAFFS_BLOCK_STATE_NEEDS_SCAN) {
2977                        yaffs_block_became_dirty(dev, block);
2978                }
2979        }
2980}
2981
2982static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
2983                             const u8 *buffer, int n_bytes, int use_reserve)
2984{
2985        /* Find old chunk Need to do this to get serial number
2986         * Write new one and patch into tree.
2987         * Invalidate old tags.
2988         */
2989
2990        int prev_chunk_id;
2991        struct yaffs_ext_tags prev_tags;
2992        int new_chunk_id;
2993        struct yaffs_ext_tags new_tags;
2994        struct yaffs_dev *dev = in->my_dev;
2995
2996        yaffs_check_gc(dev, 0);
2997
2998        /* Get the previous chunk at this location in the file if it exists.
2999         * If it does not exist then put a zero into the tree. This creates
3000         * the tnode now, rather than later when it is harder to clean up.
3001         */
3002        prev_chunk_id = yaffs_find_chunk_in_file(in, inode_chunk, &prev_tags);
3003        if (prev_chunk_id < 1 &&
3004            !yaffs_put_chunk_in_file(in, inode_chunk, 0, 0))
3005                return 0;
3006
3007        /* Set up new tags */
3008        memset(&new_tags, 0, sizeof(new_tags));
3009
3010        new_tags.chunk_id = inode_chunk;
3011        new_tags.obj_id = in->obj_id;
3012        new_tags.serial_number =
3013            (prev_chunk_id > 0) ? prev_tags.serial_number + 1 : 1;
3014        new_tags.n_bytes = n_bytes;
3015
3016        if (n_bytes < 1 || n_bytes > dev->param.total_bytes_per_chunk) {
3017                yaffs_trace(YAFFS_TRACE_ERROR,
3018                  "Writing %d bytes to chunk!!!!!!!!!",
3019                   n_bytes);
3020                BUG();
3021        }
3022
3023        new_chunk_id =
3024            yaffs_write_new_chunk(dev, buffer, &new_tags, use_reserve);
3025
3026        if (new_chunk_id > 0) {
3027                yaffs_put_chunk_in_file(in, inode_chunk, new_chunk_id, 0);
3028
3029                if (prev_chunk_id > 0)
3030                        yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
3031
3032                yaffs_verify_file_sane(in);
3033        }
3034        return new_chunk_id;
3035
3036}
3037
3038
3039
3040static int yaffs_do_xattrib_mod(struct yaffs_obj *obj, int set,
3041                                const YCHAR *name, const void *value, int size,
3042                                int flags)
3043{
3044        struct yaffs_xattr_mod xmod;
3045        int result;
3046
3047        xmod.set = set;
3048        xmod.name = name;
3049        xmod.data = value;
3050        xmod.size = size;
3051        xmod.flags = flags;
3052        xmod.result = -ENOSPC;
3053
3054        result = yaffs_update_oh(obj, NULL, 0, 0, 0, &xmod);
3055
3056        if (result > 0)
3057                return xmod.result;
3058        else
3059                return -ENOSPC;
3060}
3061
3062static int yaffs_apply_xattrib_mod(struct yaffs_obj *obj, char *buffer,
3063                                   struct yaffs_xattr_mod *xmod)
3064{
3065        int retval = 0;
3066        int x_offs = sizeof(struct yaffs_obj_hdr);
3067        struct yaffs_dev *dev = obj->my_dev;
3068        int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
3069        char *x_buffer = buffer + x_offs;
3070
3071        if (xmod->set)
3072                retval =
3073                    nval_set(x_buffer, x_size, xmod->name, xmod->data,
3074                             xmod->size, xmod->flags);
3075        else
3076                retval = nval_del(x_buffer, x_size, xmod->name);
3077
3078        obj->has_xattr = nval_hasvalues(x_buffer, x_size);
3079        obj->xattr_known = 1;
3080        xmod->result = retval;
3081
3082        return retval;
3083}
3084
3085static int yaffs_do_xattrib_fetch(struct yaffs_obj *obj, const YCHAR *name,
3086                                  void *value, int size)
3087{
3088        char *buffer = NULL;
3089        int result;
3090        struct yaffs_ext_tags tags;
3091        struct yaffs_dev *dev = obj->my_dev;
3092        int x_offs = sizeof(struct yaffs_obj_hdr);
3093        int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
3094        char *x_buffer;
3095        int retval = 0;
3096
3097        if (obj->hdr_chunk < 1)
3098                return -ENODATA;
3099
3100        /* If we know that the object has no xattribs then don't do all the
3101         * reading and parsing.
3102         */
3103        if (obj->xattr_known && !obj->has_xattr) {
3104                if (name)
3105                        return -ENODATA;
3106                else
3107                        return 0;
3108        }
3109
3110        buffer = (char *)yaffs_get_temp_buffer(dev);
3111        if (!buffer)
3112                return -ENOMEM;
3113
3114        result =
3115            yaffs_rd_chunk_tags_nand(dev, obj->hdr_chunk, (u8 *) buffer, &tags);
3116
3117        if (result != YAFFS_OK)
3118                retval = -ENOENT;
3119        else {
3120                x_buffer = buffer + x_offs;
3121
3122                if (!obj->xattr_known) {
3123                        obj->has_xattr = nval_hasvalues(x_buffer, x_size);
3124                        obj->xattr_known = 1;
3125                }
3126
3127                if (name)
3128                        retval = nval_get(x_buffer, x_size, name, value, size);
3129                else
3130                        retval = nval_list(x_buffer, x_size, value, size);
3131        }
3132        yaffs_release_temp_buffer(dev, (u8 *) buffer);
3133        return retval;
3134}
3135
3136int yaffs_set_xattrib(struct yaffs_obj *obj, const YCHAR * name,
3137                      const void *value, int size, int flags)
3138{
3139        return yaffs_do_xattrib_mod(obj, 1, name, value, size, flags);
3140}
3141
3142int yaffs_remove_xattrib(struct yaffs_obj *obj, const YCHAR * name)
3143{
3144        return yaffs_do_xattrib_mod(obj, 0, name, NULL, 0, 0);
3145}
3146
3147int yaffs_get_xattrib(struct yaffs_obj *obj, const YCHAR * name, void *value,
3148                      int size)
3149{
3150        return yaffs_do_xattrib_fetch(obj, name, value, size);
3151}
3152
3153int yaffs_list_xattrib(struct yaffs_obj *obj, char *buffer, int size)
3154{
3155        return yaffs_do_xattrib_fetch(obj, NULL, buffer, size);
3156}
3157
3158static void yaffs_check_obj_details_loaded(struct yaffs_obj *in)
3159{
3160        u8 *buf;
3161        struct yaffs_obj_hdr *oh;
3162        struct yaffs_dev *dev;
3163        struct yaffs_ext_tags tags;
3164
3165        if (!in || !in->lazy_loaded || in->hdr_chunk < 1)
3166                return;
3167
3168        dev = in->my_dev;
3169        in->lazy_loaded = 0;
3170        buf = yaffs_get_temp_buffer(dev);
3171
3172        yaffs_rd_chunk_tags_nand(dev, in->hdr_chunk, buf, &tags);
3173        oh = (struct yaffs_obj_hdr *)buf;
3174
3175        in->yst_mode = oh->yst_mode;
3176        yaffs_load_attribs(in, oh);
3177        yaffs_set_obj_name_from_oh(in, oh);
3178
3179        if (in->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
3180                in->variant.symlink_variant.alias =
3181                    yaffs_clone_str(oh->alias);
3182        }
3183        yaffs_release_temp_buffer(dev, buf);
3184}
3185
3186static void yaffs_load_name_from_oh(struct yaffs_dev *dev, YCHAR *name,
3187                                    const YCHAR *oh_name, int buff_size)
3188{
3189#ifdef CONFIG_YAFFS_AUTO_UNICODE
3190        if (dev->param.auto_unicode) {
3191                if (*oh_name) {
3192                        /* It is an ASCII name, do an ASCII to
3193                         * unicode conversion */
3194                        const char *ascii_oh_name = (const char *)oh_name;
3195                        int n = buff_size - 1;
3196                        while (n > 0 && *ascii_oh_name) {
3197                                *name = *ascii_oh_name;
3198                                name++;
3199                                ascii_oh_name++;
3200                                n--;
3201                        }
3202                } else {
3203                        yaffs_strncpy(name, oh_name + 1, buff_size - 1);
3204                }
3205
3206                return;
3207        }
3208#endif
3209
3210        yaffs_strncpy(name, oh_name, buff_size - 1);
3211}
3212
3213static void yaffs_load_oh_from_name(struct yaffs_dev *dev, YCHAR *oh_name,
3214                                    const YCHAR *name)
3215{
3216#ifdef CONFIG_YAFFS_AUTO_UNICODE
3217        int is_ascii;
3218        YCHAR *w;
3219
3220        if (dev->param.auto_unicode) {
3221
3222                is_ascii = 1;
3223                w = name;
3224
3225                /* Figure out if the name will fit in ascii character set */
3226                while (is_ascii && *w) {
3227                        if ((*w) & 0xff00)
3228                                is_ascii = 0;
3229                        w++;
3230                }
3231
3232                if (is_ascii) {
3233                        /* It is an ASCII name, so convert unicode to ascii */
3234                        char *ascii_oh_name = (char *)oh_name;
3235                        int n = YAFFS_MAX_NAME_LENGTH - 1;
3236                        while (n > 0 && *name) {
3237                                *ascii_oh_name = *name;
3238                                name++;
3239                                ascii_oh_name++;
3240                                n--;
3241                        }
3242                } else {
3243                        /* Unicode name, so save starting at the second YCHAR */
3244                        *oh_name = 0;
3245                        yaffs_strncpy(oh_name + 1, name, YAFFS_MAX_NAME_LENGTH - 2);
3246                }
3247
3248                return;
3249        }
3250#endif
3251
3252        yaffs_strncpy(oh_name, name, YAFFS_MAX_NAME_LENGTH - 1);
3253}
3254
3255/* UpdateObjectHeader updates the header on NAND for an object.
3256 * If name is not NULL, then that new name is used.
3257 */
3258int yaffs_update_oh(struct yaffs_obj *in, const YCHAR *name, int force,
3259                    int is_shrink, int shadows, struct yaffs_xattr_mod *xmod)
3260{
3261
3262        struct yaffs_block_info *bi;
3263        struct yaffs_dev *dev = in->my_dev;
3264        int prev_chunk_id;
3265        int ret_val = 0;
3266        int new_chunk_id;
3267        struct yaffs_ext_tags new_tags;
3268        struct yaffs_ext_tags old_tags;
3269        const YCHAR *alias = NULL;
3270        u8 *buffer = NULL;
3271        YCHAR old_name[YAFFS_MAX_NAME_LENGTH + 1];
3272        struct yaffs_obj_hdr *oh = NULL;
3273        loff_t file_size = 0;
3274
3275        yaffs_strcpy(old_name, _Y("silly old name"));
3276
3277        if (in->fake && in != dev->root_dir && !force && !xmod)
3278                return ret_val;
3279
3280        yaffs_check_gc(dev, 0);
3281        yaffs_check_obj_details_loaded(in);
3282
3283        buffer = yaffs_get_temp_buffer(in->my_dev);
3284        oh = (struct yaffs_obj_hdr *)buffer;
3285
3286        prev_chunk_id = in->hdr_chunk;
3287
3288        if (prev_chunk_id > 0) {
3289                yaffs_rd_chunk_tags_nand(dev, prev_chunk_id,
3290                                          buffer, &old_tags);
3291
3292                yaffs_verify_oh(in, oh, &old_tags, 0);
3293                memcpy(old_name, oh->name, sizeof(oh->name));
3294                memset(buffer, 0xff, sizeof(struct yaffs_obj_hdr));
3295        } else {
3296                memset(buffer, 0xff, dev->data_bytes_per_chunk);
3297        }
3298
3299        oh->type = in->variant_type;
3300        oh->yst_mode = in->yst_mode;
3301        oh->shadows_obj = oh->inband_shadowed_obj_id = shadows;
3302
3303        yaffs_load_attribs_oh(oh, in);
3304
3305        if (in->parent)
3306                oh->parent_obj_id = in->parent->obj_id;
3307        else
3308                oh->parent_obj_id = 0;
3309
3310        if (name && *name) {
3311                memset(oh->name, 0, sizeof(oh->name));
3312                yaffs_load_oh_from_name(dev, oh->name, name);
3313        } else if (prev_chunk_id > 0) {
3314                memcpy(oh->name, old_name, sizeof(oh->name));
3315        } else {
3316                memset(oh->name, 0, sizeof(oh->name));
3317        }
3318
3319        oh->is_shrink = is_shrink;
3320
3321        switch (in->variant_type) {
3322        case YAFFS_OBJECT_TYPE_UNKNOWN:
3323                /* Should not happen */
3324                break;
3325        case YAFFS_OBJECT_TYPE_FILE:
3326                if (oh->parent_obj_id != YAFFS_OBJECTID_DELETED &&
3327                    oh->parent_obj_id != YAFFS_OBJECTID_UNLINKED)
3328                        file_size = in->variant.file_variant.file_size;
3329                yaffs_oh_size_load(oh, file_size);
3330                break;
3331        case YAFFS_OBJECT_TYPE_HARDLINK:
3332                oh->equiv_id = in->variant.hardlink_variant.equiv_id;
3333                break;
3334        case YAFFS_OBJECT_TYPE_SPECIAL:
3335                /* Do nothing */
3336                break;
3337        case YAFFS_OBJECT_TYPE_DIRECTORY:
3338                /* Do nothing */
3339                break;
3340        case YAFFS_OBJECT_TYPE_SYMLINK:
3341                alias = in->variant.symlink_variant.alias;
3342                if (!alias)
3343                        alias = _Y("no alias");
3344                yaffs_strncpy(oh->alias, alias, YAFFS_MAX_ALIAS_LENGTH);
3345                oh->alias[YAFFS_MAX_ALIAS_LENGTH] = 0;
3346                break;
3347        }
3348
3349        /* process any xattrib modifications */
3350        if (xmod)
3351                yaffs_apply_xattrib_mod(in, (char *)buffer, xmod);
3352
3353        /* Tags */
3354        memset(&new_tags, 0, sizeof(new_tags));
3355        in->serial++;
3356        new_tags.chunk_id = 0;
3357        new_tags.obj_id = in->obj_id;
3358        new_tags.serial_number = in->serial;
3359
3360        /* Add extra info for file header */
3361        new_tags.extra_available = 1;
3362        new_tags.extra_parent_id = oh->parent_obj_id;
3363        new_tags.extra_file_size = file_size;
3364        new_tags.extra_is_shrink = oh->is_shrink;
3365        new_tags.extra_equiv_id = oh->equiv_id;
3366        new_tags.extra_shadows = (oh->shadows_obj > 0) ? 1 : 0;
3367        new_tags.extra_obj_type = in->variant_type;
3368        yaffs_verify_oh(in, oh, &new_tags, 1);
3369
3370        /* Create new chunk in NAND */
3371        new_chunk_id =
3372            yaffs_write_new_chunk(dev, buffer, &new_tags,
3373                                  (prev_chunk_id > 0) ? 1 : 0);
3374
3375        if (buffer)
3376                yaffs_release_temp_buffer(dev, buffer);
3377
3378        if (new_chunk_id < 0)
3379                return new_chunk_id;
3380
3381        in->hdr_chunk = new_chunk_id;
3382
3383        if (prev_chunk_id > 0)
3384                yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
3385
3386        if (!yaffs_obj_cache_dirty(in))
3387                in->dirty = 0;
3388
3389        /* If this was a shrink, then mark the block
3390         * that the chunk lives on */
3391        if (is_shrink) {
3392                bi = yaffs_get_block_info(in->my_dev,
3393                                          new_chunk_id /
3394                                          in->my_dev->param.chunks_per_block);
3395                bi->has_shrink_hdr = 1;
3396        }
3397
3398
3399        return new_chunk_id;
3400}
3401
3402/*--------------------- File read/write ------------------------
3403 * Read and write have very similar structures.
3404 * In general the read/write has three parts to it
3405 * An incomplete chunk to start with (if the read/write is not chunk-aligned)
3406 * Some complete chunks
3407 * An incomplete chunk to end off with
3408 *
3409 * Curve-balls: the first chunk might also be the last chunk.
3410 */
3411
3412int yaffs_file_rd(struct yaffs_obj *in, u8 * buffer, loff_t offset, int n_bytes)
3413{
3414        int chunk;
3415        u32 start;
3416        int n_copy;
3417        int n = n_bytes;
3418        int n_done = 0;
3419        struct yaffs_cache *cache;
3420        struct yaffs_dev *dev;
3421
3422        dev = in->my_dev;
3423
3424        while (n > 0) {
3425                yaffs_addr_to_chunk(dev, offset, &chunk, &start);
3426                chunk++;
3427
3428                /* OK now check for the curveball where the start and end are in
3429                 * the same chunk.
3430                 */
3431                if ((start + n) < dev->data_bytes_per_chunk)
3432                        n_copy = n;
3433                else
3434                        n_copy = dev->data_bytes_per_chunk - start;
3435
3436                cache = yaffs_find_chunk_cache(in, chunk);
3437
3438                /* If the chunk is already in the cache or it is less than
3439                 * a whole chunk or we're using inband tags then use the cache
3440                 * (if there is caching) else bypass the cache.
3441                 */
3442                if (cache || n_copy != dev->data_bytes_per_chunk ||
3443                    dev->param.inband_tags) {
3444                        if (dev->param.n_caches > 0) {
3445
3446                                /* If we can't find the data in the cache,
3447                                 * then load it up. */
3448
3449                                if (!cache) {
3450                                        cache =
3451                                            yaffs_grab_chunk_cache(in->my_dev);
3452                                        cache->object = in;
3453                                        cache->chunk_id = chunk;
3454                                        cache->dirty = 0;
3455                                        cache->locked = 0;
3456                                        yaffs_rd_data_obj(in, chunk,
3457                                                          cache->data);
3458                                        cache->n_bytes = 0;
3459                                }
3460
3461                                yaffs_use_cache(dev, cache, 0);
3462
3463                                cache->locked = 1;
3464
3465                                memcpy(buffer, &cache->data[start], n_copy);
3466
3467                                cache->locked = 0;
3468                        } else {
3469                                /* Read into the local buffer then copy.. */
3470
3471                                u8 *local_buffer =
3472                                    yaffs_get_temp_buffer(dev);
3473                                yaffs_rd_data_obj(in, chunk, local_buffer);
3474
3475                                memcpy(buffer, &local_buffer[start], n_copy);
3476
3477                                yaffs_release_temp_buffer(dev, local_buffer);
3478                        }
3479                } else {
3480                        /* A full chunk. Read directly into the buffer. */
3481                        yaffs_rd_data_obj(in, chunk, buffer);
3482                }
3483                n -= n_copy;
3484                offset += n_copy;
3485                buffer += n_copy;
3486                n_done += n_copy;
3487        }
3488        return n_done;
3489}
3490
3491int yaffs_do_file_wr(struct yaffs_obj *in, const u8 *buffer, loff_t offset,
3492                     int n_bytes, int write_through)
3493{
3494
3495        int chunk;
3496        u32 start;
3497        int n_copy;
3498        int n = n_bytes;
3499        int n_done = 0;
3500        int n_writeback;
3501        loff_t start_write = offset;
3502        int chunk_written = 0;
3503        u32 n_bytes_read;
3504        loff_t chunk_start;
3505        struct yaffs_dev *dev;
3506
3507        dev = in->my_dev;
3508
3509        while (n > 0 && chunk_written >= 0) {
3510                yaffs_addr_to_chunk(dev, offset, &chunk, &start);
3511
3512                if (((loff_t)chunk) *
3513                    dev->data_bytes_per_chunk + start != offset ||
3514                    start >= dev->data_bytes_per_chunk) {
3515                        yaffs_trace(YAFFS_TRACE_ERROR,
3516                                "AddrToChunk of offset %lld gives chunk %d start %d",
3517                                offset, chunk, start);
3518                }
3519                chunk++;        /* File pos to chunk in file offset */
3520
3521                /* OK now check for the curveball where the start and end are in
3522                 * the same chunk.
3523                 */
3524
3525                if ((start + n) < dev->data_bytes_per_chunk) {
3526                        n_copy = n;
3527
3528                        /* Now calculate how many bytes to write back....
3529                         * If we're overwriting and not writing to then end of
3530                         * file then we need to write back as much as was there
3531                         * before.
3532                         */
3533
3534                        chunk_start = (((loff_t)(chunk - 1)) *
3535                                        dev->data_bytes_per_chunk);
3536
3537                        if (chunk_start > in->variant.file_variant.file_size)
3538                                n_bytes_read = 0;       /* Past end of file */
3539                        else
3540                                n_bytes_read =
3541                                    in->variant.file_variant.file_size -
3542                                    chunk_start;
3543
3544                        if (n_bytes_read > dev->data_bytes_per_chunk)
3545                                n_bytes_read = dev->data_bytes_per_chunk;
3546
3547                        n_writeback =
3548                            (n_bytes_read >
3549                             (start + n)) ? n_bytes_read : (start + n);
3550
3551                        if (n_writeback < 0 ||
3552                            n_writeback > dev->data_bytes_per_chunk)
3553                                BUG();
3554
3555                } else {
3556                        n_copy = dev->data_bytes_per_chunk - start;
3557                        n_writeback = dev->data_bytes_per_chunk;
3558                }
3559
3560                if (n_copy != dev->data_bytes_per_chunk ||
3561                    dev->param.inband_tags) {
3562                        /* An incomplete start or end chunk (or maybe both
3563                         * start and end chunk), or we're using inband tags,
3564                         * so we want to use the cache buffers.
3565                         */
3566                        if (dev->param.n_caches > 0) {
3567                                struct yaffs_cache *cache;
3568
3569                                /* If we can't find the data in the cache, then
3570                                 * load the cache */
3571                                cache = yaffs_find_chunk_cache(in, chunk);
3572
3573                                if (!cache &&
3574                                    yaffs_check_alloc_available(dev, 1)) {
3575                                        cache = yaffs_grab_chunk_cache(dev);
3576                                        cache->object = in;
3577                                        cache->chunk_id = chunk;
3578                                        cache->dirty = 0;
3579                                        cache->locked = 0;
3580                                        yaffs_rd_data_obj(in, chunk,
3581                                                          cache->data);
3582                                } else if (cache &&
3583                                           !cache->dirty &&
3584                                           !yaffs_check_alloc_available(dev,
3585                                                                        1)) {
3586                                        /* Drop the cache if it was a read cache
3587                                         * item and no space check has been made
3588                                         * for it.
3589                                         */
3590                                        cache = NULL;
3591                                }
3592
3593                                if (cache) {
3594                                        yaffs_use_cache(dev, cache, 1);
3595                                        cache->locked = 1;
3596
3597                                        memcpy(&cache->data[start], buffer,
3598                                               n_copy);
3599
3600                                        cache->locked = 0;
3601                                        cache->n_bytes = n_writeback;
3602
3603                                        if (write_through) {
3604                                                chunk_written =
3605                                                    yaffs_wr_data_obj
3606                                                    (cache->object,
3607                                                     cache->chunk_id,
3608                                                     cache->data,
3609                                                     cache->n_bytes, 1);
3610                                                cache->dirty = 0;
3611                                        }
3612                                } else {
3613                                        chunk_written = -1;     /* fail write */
3614                                }
3615                        } else {
3616                                /* An incomplete start or end chunk (or maybe
3617                                 * both start and end chunk). Read into the
3618                                 * local buffer then copy over and write back.
3619                                 */
3620
3621                                u8 *local_buffer = yaffs_get_temp_buffer(dev);
3622
3623                                yaffs_rd_data_obj(in, chunk, local_buffer);
3624                                memcpy(&local_buffer[start], buffer, n_copy);
3625
3626                                chunk_written =
3627                                    yaffs_wr_data_obj(in, chunk,
3628                                                      local_buffer,
3629                                                      n_writeback, 0);
3630
3631                                yaffs_release_temp_buffer(dev, local_buffer);
3632                        }
3633                } else {
3634                        /* A full chunk. Write directly from the buffer. */
3635
3636                        chunk_written =
3637                            yaffs_wr_data_obj(in, chunk, buffer,
3638                                              dev->data_bytes_per_chunk, 0);
3639
3640                        /* Since we've overwritten the cached data,
3641                         * we better invalidate it. */
3642                        yaffs_invalidate_chunk_cache(in, chunk);
3643                }
3644
3645                if (chunk_written >= 0) {
3646                        n -= n_copy;
3647                        offset += n_copy;
3648                        buffer += n_copy;
3649                        n_done += n_copy;
3650                }
3651        }
3652
3653        /* Update file object */
3654
3655        if ((start_write + n_done) > in->variant.file_variant.file_size)
3656                in->variant.file_variant.file_size = (start_write + n_done);
3657
3658        in->dirty = 1;
3659        return n_done;
3660}
3661
3662int yaffs_wr_file(struct yaffs_obj *in, const u8 *buffer, loff_t offset,
3663                  int n_bytes, int write_through)
3664{
3665        yaffs2_handle_hole(in, offset);
3666        return yaffs_do_file_wr(in, buffer, offset, n_bytes, write_through);
3667}
3668
3669/* ---------------------- File resizing stuff ------------------ */
3670
3671static void yaffs_prune_chunks(struct yaffs_obj *in, loff_t new_size)
3672{
3673
3674        struct yaffs_dev *dev = in->my_dev;
3675        loff_t old_size = in->variant.file_variant.file_size;
3676        int i;
3677        int chunk_id;
3678        u32 dummy;
3679        int last_del;
3680        int start_del;
3681
3682        if (old_size > 0)
3683                yaffs_addr_to_chunk(dev, old_size - 1, &last_del, &dummy);
3684        else
3685                last_del = 0;
3686
3687        yaffs_addr_to_chunk(dev, new_size + dev->data_bytes_per_chunk - 1,
3688                                &start_del, &dummy);
3689        last_del++;
3690        start_del++;
3691
3692        /* Delete backwards so that we don't end up with holes if
3693         * power is lost part-way through the operation.
3694         */
3695        for (i = last_del; i >= start_del; i--) {
3696                /* NB this could be optimised somewhat,
3697                 * eg. could retrieve the tags and write them without
3698                 * using yaffs_chunk_del
3699                 */
3700
3701                chunk_id = yaffs_find_del_file_chunk(in, i, NULL);
3702
3703                if (chunk_id < 1)
3704                        continue;
3705
3706                if (chunk_id <
3707                    (dev->internal_start_block * dev->param.chunks_per_block) ||
3708                    chunk_id >=
3709                    ((dev->internal_end_block + 1) *
3710                      dev->param.chunks_per_block)) {
3711                        yaffs_trace(YAFFS_TRACE_ALWAYS,
3712                                "Found daft chunk_id %d for %d",
3713                                chunk_id, i);
3714                } else {
3715                        in->n_data_chunks--;
3716                        yaffs_chunk_del(dev, chunk_id, 1, __LINE__);
3717                }
3718        }
3719}
3720
3721void yaffs_resize_file_down(struct yaffs_obj *obj, loff_t new_size)
3722{
3723        int new_full;
3724        u32 new_partial;
3725        struct yaffs_dev *dev = obj->my_dev;
3726
3727        yaffs_addr_to_chunk(dev, new_size, &new_full, &new_partial);
3728
3729        yaffs_prune_chunks(obj, new_size);
3730
3731        if (new_partial != 0) {
3732                int last_chunk = 1 + new_full;
3733                u8 *local_buffer = yaffs_get_temp_buffer(dev);
3734
3735                /* Rewrite the last chunk with its new size and zero pad */
3736                yaffs_rd_data_obj(obj, last_chunk, local_buffer);
3737                memset(local_buffer + new_partial, 0,
3738                       dev->data_bytes_per_chunk - new_partial);
3739
3740                yaffs_wr_data_obj(obj, last_chunk, local_buffer,
3741                                  new_partial, 1);
3742
3743                yaffs_release_temp_buffer(dev, local_buffer);
3744        }
3745
3746        obj->variant.file_variant.file_size = new_size;
3747
3748        yaffs_prune_tree(dev, &obj->variant.file_variant);
3749}
3750
3751int yaffs_resize_file(struct yaffs_obj *in, loff_t new_size)
3752{
3753        struct yaffs_dev *dev = in->my_dev;
3754        loff_t old_size = in->variant.file_variant.file_size;
3755
3756        yaffs_flush_file_cache(in);
3757        yaffs_invalidate_whole_cache(in);
3758
3759        yaffs_check_gc(dev, 0);
3760
3761        if (in->variant_type != YAFFS_OBJECT_TYPE_FILE)
3762                return YAFFS_FAIL;
3763
3764        if (new_size == old_size)
3765                return YAFFS_OK;
3766
3767        if (new_size > old_size) {
3768                yaffs2_handle_hole(in, new_size);
3769                in->variant.file_variant.file_size = new_size;
3770        } else {
3771                /* new_size < old_size */
3772                yaffs_resize_file_down(in, new_size);
3773        }
3774
3775        /* Write a new object header to reflect the resize.
3776         * show we've shrunk the file, if need be
3777         * Do this only if the file is not in the deleted directories
3778         * and is not shadowed.
3779         */
3780        if (in->parent &&
3781            !in->is_shadowed &&
3782            in->parent->obj_id != YAFFS_OBJECTID_UNLINKED &&
3783            in->parent->obj_id != YAFFS_OBJECTID_DELETED)
3784                yaffs_update_oh(in, NULL, 0, 0, 0, NULL);
3785
3786        return YAFFS_OK;
3787}
3788
3789int yaffs_flush_file(struct yaffs_obj *in, int update_time, int data_sync)
3790{
3791        if (!in->dirty)
3792                return YAFFS_OK;
3793
3794        yaffs_flush_file_cache(in);
3795
3796        if (data_sync)
3797                return YAFFS_OK;
3798
3799        if (update_time)
3800                yaffs_load_current_time(in, 0, 0);
3801
3802        return (yaffs_update_oh(in, NULL, 0, 0, 0, NULL) >= 0) ?
3803                                YAFFS_OK : YAFFS_FAIL;
3804}
3805
3806
3807/* yaffs_del_file deletes the whole file data
3808 * and the inode associated with the file.
3809 * It does not delete the links associated with the file.
3810 */
3811static int yaffs_unlink_file_if_needed(struct yaffs_obj *in)
3812{
3813        int ret_val;
3814        int del_now = 0;
3815        struct yaffs_dev *dev = in->my_dev;
3816
3817        if (!in->my_inode)
3818                del_now = 1;
3819
3820        if (del_now) {
3821                ret_val =
3822                    yaffs_change_obj_name(in, in->my_dev->del_dir,
3823                                          _Y("deleted"), 0, 0);
3824                yaffs_trace(YAFFS_TRACE_TRACING,
3825                        "yaffs: immediate deletion of file %d",
3826                        in->obj_id);
3827                in->deleted = 1;
3828                in->my_dev->n_deleted_files++;
3829                if (dev->param.disable_soft_del || dev->param.is_yaffs2)
3830                        yaffs_resize_file(in, 0);
3831                yaffs_soft_del_file(in);
3832        } else {
3833                ret_val =
3834                    yaffs_change_obj_name(in, in->my_dev->unlinked_dir,
3835                                          _Y("unlinked"), 0, 0);
3836        }
3837        return ret_val;
3838}
3839
3840int yaffs_del_file(struct yaffs_obj *in)
3841{
3842        int ret_val = YAFFS_OK;
3843        int deleted;    /* Need to cache value on stack if in is freed */
3844        struct yaffs_dev *dev = in->my_dev;
3845
3846        if (dev->param.disable_soft_del || dev->param.is_yaffs2)
3847                yaffs_resize_file(in, 0);
3848
3849        if (in->n_data_chunks > 0) {
3850                /* Use soft deletion if there is data in the file.
3851                 * That won't be the case if it has been resized to zero.
3852                 */
3853                if (!in->unlinked)
3854                        ret_val = yaffs_unlink_file_if_needed(in);
3855
3856                deleted = in->deleted;
3857
3858                if (ret_val == YAFFS_OK && in->unlinked && !in->deleted) {
3859                        in->deleted = 1;
3860                        deleted = 1;
3861                        in->my_dev->n_deleted_files++;
3862                        yaffs_soft_del_file(in);
3863                }
3864                return deleted ? YAFFS_OK : YAFFS_FAIL;
3865        } else {
3866                /* The file has no data chunks so we toss it immediately */
3867                yaffs_free_tnode(in->my_dev, in->variant.file_variant.top);
3868                in->variant.file_variant.top = NULL;
3869                yaffs_generic_obj_del(in);
3870
3871                return YAFFS_OK;
3872        }
3873}
3874
3875int yaffs_is_non_empty_dir(struct yaffs_obj *obj)
3876{
3877        return (obj &&
3878                obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY) &&
3879                !(list_empty(&obj->variant.dir_variant.children));
3880}
3881
3882static int yaffs_del_dir(struct yaffs_obj *obj)
3883{
3884        /* First check that the directory is empty. */
3885        if (yaffs_is_non_empty_dir(obj))
3886                return YAFFS_FAIL;
3887
3888        return yaffs_generic_obj_del(obj);
3889}
3890
3891static int yaffs_del_symlink(struct yaffs_obj *in)
3892{
3893        kfree(in->variant.symlink_variant.alias);
3894        in->variant.symlink_variant.alias = NULL;
3895
3896        return yaffs_generic_obj_del(in);
3897}
3898
3899static int yaffs_del_link(struct yaffs_obj *in)
3900{
3901        /* remove this hardlink from the list associated with the equivalent
3902         * object
3903         */
3904        list_del_init(&in->hard_links);
3905        return yaffs_generic_obj_del(in);
3906}
3907
3908int yaffs_del_obj(struct yaffs_obj *obj)
3909{
3910        int ret_val = -1;
3911
3912        switch (obj->variant_type) {
3913        case YAFFS_OBJECT_TYPE_FILE:
3914                ret_val = yaffs_del_file(obj);
3915                break;
3916        case YAFFS_OBJECT_TYPE_DIRECTORY:
3917                if (!list_empty(&obj->variant.dir_variant.dirty)) {
3918                        yaffs_trace(YAFFS_TRACE_BACKGROUND,
3919                                "Remove object %d from dirty directories",
3920                                obj->obj_id);
3921                        list_del_init(&obj->variant.dir_variant.dirty);
3922                }
3923                return yaffs_del_dir(obj);
3924                break;
3925        case YAFFS_OBJECT_TYPE_SYMLINK:
3926                ret_val = yaffs_del_symlink(obj);
3927                break;
3928        case YAFFS_OBJECT_TYPE_HARDLINK:
3929                ret_val = yaffs_del_link(obj);
3930                break;
3931        case YAFFS_OBJECT_TYPE_SPECIAL:
3932                ret_val = yaffs_generic_obj_del(obj);
3933                break;
3934        case YAFFS_OBJECT_TYPE_UNKNOWN:
3935                ret_val = 0;
3936                break;          /* should not happen. */
3937        }
3938        return ret_val;
3939}
3940
3941static int yaffs_unlink_worker(struct yaffs_obj *obj)
3942{
3943        int del_now = 0;
3944
3945        if (!obj)
3946                return YAFFS_FAIL;
3947
3948        if (!obj->my_inode)
3949                del_now = 1;
3950
3951        yaffs_update_parent(obj->parent);
3952
3953        if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
3954                return yaffs_del_link(obj);
3955        } else if (!list_empty(&obj->hard_links)) {
3956                /* Curve ball: We're unlinking an object that has a hardlink.
3957                 *
3958                 * This problem arises because we are not strictly following
3959                 * The Linux link/inode model.
3960                 *
3961                 * We can't really delete the object.
3962                 * Instead, we do the following:
3963                 * - Select a hardlink.
3964                 * - Unhook it from the hard links
3965                 * - Move it from its parent directory so that the rename works.
3966                 * - Rename the object to the hardlink's name.
3967                 * - Delete the hardlink
3968                 */
3969
3970                struct yaffs_obj *hl;
3971                struct yaffs_obj *parent;
3972                int ret_val;
3973                YCHAR name[YAFFS_MAX_NAME_LENGTH + 1];
3974
3975                hl = list_entry(obj->hard_links.next, struct yaffs_obj,
3976                                hard_links);
3977
3978                yaffs_get_obj_name(hl, name, YAFFS_MAX_NAME_LENGTH + 1);
3979                parent = hl->parent;
3980
3981                list_del_init(&hl->hard_links);
3982
3983                yaffs_add_obj_to_dir(obj->my_dev->unlinked_dir, hl);
3984
3985                ret_val = yaffs_change_obj_name(obj, parent, name, 0, 0);
3986
3987                if (ret_val == YAFFS_OK)
3988                        ret_val = yaffs_generic_obj_del(hl);
3989
3990                return ret_val;
3991
3992        } else if (del_now) {
3993                switch (obj->variant_type) {
3994                case YAFFS_OBJECT_TYPE_FILE:
3995                        return yaffs_del_file(obj);
3996                        break;
3997                case YAFFS_OBJECT_TYPE_DIRECTORY:
3998                        list_del_init(&obj->variant.dir_variant.dirty);
3999                        return yaffs_del_dir(obj);
4000                        break;
4001                case YAFFS_OBJECT_TYPE_SYMLINK:
4002                        return yaffs_del_symlink(obj);
4003                        break;
4004                case YAFFS_OBJECT_TYPE_SPECIAL:
4005                        return yaffs_generic_obj_del(obj);
4006                        break;
4007                case YAFFS_OBJECT_TYPE_HARDLINK:
4008                case YAFFS_OBJECT_TYPE_UNKNOWN:
4009                default:
4010                        return YAFFS_FAIL;
4011                }
4012        } else if (yaffs_is_non_empty_dir(obj)) {
4013                return YAFFS_FAIL;
4014        } else {
4015                return yaffs_change_obj_name(obj, obj->my_dev->unlinked_dir,
4016                                                _Y("unlinked"), 0, 0);
4017        }
4018}
4019
4020static int yaffs_unlink_obj(struct yaffs_obj *obj)
4021{
4022        if (obj && obj->unlink_allowed)
4023                return yaffs_unlink_worker(obj);
4024
4025        return YAFFS_FAIL;
4026}
4027
4028int yaffs_unlinker(struct yaffs_obj *dir, const YCHAR *name)
4029{
4030        struct yaffs_obj *obj;
4031
4032        obj = yaffs_find_by_name(dir, name);
4033        return yaffs_unlink_obj(obj);
4034}
4035
4036/* Note:
4037 * If old_name is NULL then we take old_dir as the object to be renamed.
4038 */
4039int yaffs_rename_obj(struct yaffs_obj *old_dir, const YCHAR *old_name,
4040                     struct yaffs_obj *new_dir, const YCHAR *new_name)
4041{
4042        struct yaffs_obj *obj = NULL;
4043        struct yaffs_obj *existing_target = NULL;
4044        int force = 0;
4045        int result;
4046        struct yaffs_dev *dev;
4047
4048        if (!old_dir || old_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4049                BUG();
4050                return YAFFS_FAIL;
4051        }
4052        if (!new_dir || new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4053                BUG();
4054                return YAFFS_FAIL;
4055        }
4056
4057        dev = old_dir->my_dev;
4058
4059#ifdef CONFIG_YAFFS_CASE_INSENSITIVE
4060        /* Special case for case insemsitive systems.
4061         * While look-up is case insensitive, the name isn't.
4062         * Therefore we might want to change x.txt to X.txt
4063         */
4064        if (old_dir == new_dir &&
4065                old_name && new_name &&
4066                yaffs_strcmp(old_name, new_name) == 0)
4067                force = 1;
4068#endif
4069
4070        if (yaffs_strnlen(new_name, YAFFS_MAX_NAME_LENGTH + 1) >
4071            YAFFS_MAX_NAME_LENGTH)
4072                /* ENAMETOOLONG */
4073                return YAFFS_FAIL;
4074
4075        if (old_name)
4076                obj = yaffs_find_by_name(old_dir, old_name);
4077        else{
4078                obj = old_dir;
4079                old_dir = obj->parent;
4080        }
4081
4082        if (obj && obj->rename_allowed) {
4083                /* Now handle an existing target, if there is one */
4084                existing_target = yaffs_find_by_name(new_dir, new_name);
4085                if (yaffs_is_non_empty_dir(existing_target)) {
4086                        return YAFFS_FAIL;      /* ENOTEMPTY */
4087                } else if (existing_target && existing_target != obj) {
4088                        /* Nuke the target first, using shadowing,
4089                         * but only if it isn't the same object.
4090                         *
4091                         * Note we must disable gc here otherwise it can mess
4092                         * up the shadowing.
4093                         *
4094                         */
4095                        dev->gc_disable = 1;
4096                        yaffs_change_obj_name(obj, new_dir, new_name, force,
4097                                              existing_target->obj_id);
4098                        existing_target->is_shadowed = 1;
4099                        yaffs_unlink_obj(existing_target);
4100                        dev->gc_disable = 0;
4101                }
4102
4103                result = yaffs_change_obj_name(obj, new_dir, new_name, 1, 0);
4104
4105                yaffs_update_parent(old_dir);
4106                if (new_dir != old_dir)
4107                        yaffs_update_parent(new_dir);
4108
4109                return result;
4110        }
4111        return YAFFS_FAIL;
4112}
4113
4114/*----------------------- Initialisation Scanning ---------------------- */
4115
4116void yaffs_handle_shadowed_obj(struct yaffs_dev *dev, int obj_id,
4117                               int backward_scanning)
4118{
4119        struct yaffs_obj *obj;
4120
4121        if (backward_scanning) {
4122                /* Handle YAFFS2 case (backward scanning)
4123                 * If the shadowed object exists then ignore.
4124                 */
4125                obj = yaffs_find_by_number(dev, obj_id);
4126                if (obj)
4127                        return;
4128        }
4129
4130        /* Let's create it (if it does not exist) assuming it is a file so that
4131         * it can do shrinking etc.
4132         * We put it in unlinked dir to be cleaned up after the scanning
4133         */
4134        obj =
4135            yaffs_find_or_create_by_number(dev, obj_id, YAFFS_OBJECT_TYPE_FILE);
4136        if (!obj)
4137                return;
4138        obj->is_shadowed = 1;
4139        yaffs_add_obj_to_dir(dev->unlinked_dir, obj);
4140        obj->variant.file_variant.shrink_size = 0;
4141        obj->valid = 1;         /* So that we don't read any other info. */
4142}
4143
4144void yaffs_link_fixup(struct yaffs_dev *dev, struct list_head *hard_list)
4145{
4146        struct list_head *lh;
4147        struct list_head *save;
4148        struct yaffs_obj *hl;
4149        struct yaffs_obj *in;
4150
4151        list_for_each_safe(lh, save, hard_list) {
4152                hl = list_entry(lh, struct yaffs_obj, hard_links);
4153                in = yaffs_find_by_number(dev,
4154                                        hl->variant.hardlink_variant.equiv_id);
4155
4156                if (in) {
4157                        /* Add the hardlink pointers */
4158                        hl->variant.hardlink_variant.equiv_obj = in;
4159                        list_add(&hl->hard_links, &in->hard_links);
4160                } else {
4161                        /* Todo Need to report/handle this better.
4162                         * Got a problem... hardlink to a non-existant object
4163                         */
4164                        hl->variant.hardlink_variant.equiv_obj = NULL;
4165                        INIT_LIST_HEAD(&hl->hard_links);
4166                }
4167        }
4168}
4169
4170static void yaffs_strip_deleted_objs(struct yaffs_dev *dev)
4171{
4172        /*
4173         *  Sort out state of unlinked and deleted objects after scanning.
4174         */
4175        struct list_head *i;
4176        struct list_head *n;
4177        struct yaffs_obj *l;
4178
4179        if (dev->read_only)
4180                return;
4181
4182        /* Soft delete all the unlinked files */
4183        list_for_each_safe(i, n,
4184                           &dev->unlinked_dir->variant.dir_variant.children) {
4185                l = list_entry(i, struct yaffs_obj, siblings);
4186                yaffs_del_obj(l);
4187        }
4188
4189        list_for_each_safe(i, n, &dev->del_dir->variant.dir_variant.children) {
4190                l = list_entry(i, struct yaffs_obj, siblings);
4191                yaffs_del_obj(l);
4192        }
4193}
4194
4195/*
4196 * This code iterates through all the objects making sure that they are rooted.
4197 * Any unrooted objects are re-rooted in lost+found.
4198 * An object needs to be in one of:
4199 * - Directly under deleted, unlinked
4200 * - Directly or indirectly under root.
4201 *
4202 * Note:
4203 *  This code assumes that we don't ever change the current relationships
4204 *  between directories:
4205 *   root_dir->parent == unlinked_dir->parent == del_dir->parent == NULL
4206 *   lost-n-found->parent == root_dir
4207 *
4208 * This fixes the problem where directories might have inadvertently been
4209 * deleted leaving the object "hanging" without being rooted in the
4210 * directory tree.
4211 */
4212
4213static int yaffs_has_null_parent(struct yaffs_dev *dev, struct yaffs_obj *obj)
4214{
4215        return (obj == dev->del_dir ||
4216                obj == dev->unlinked_dir || obj == dev->root_dir);
4217}
4218
4219static void yaffs_fix_hanging_objs(struct yaffs_dev *dev)
4220{
4221        struct yaffs_obj *obj;
4222        struct yaffs_obj *parent;
4223        int i;
4224        struct list_head *lh;
4225        struct list_head *n;
4226        int depth_limit;
4227        int hanging;
4228
4229        if (dev->read_only)
4230                return;
4231
4232        /* Iterate through the objects in each hash entry,
4233         * looking at each object.
4234         * Make sure it is rooted.
4235         */
4236
4237        for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
4238                list_for_each_safe(lh, n, &dev->obj_bucket[i].list) {
4239                        obj = list_entry(lh, struct yaffs_obj, hash_link);
4240                        parent = obj->parent;
4241
4242                        if (yaffs_has_null_parent(dev, obj)) {
4243                                /* These directories are not hanging */
4244                                hanging = 0;
4245                        } else if (!parent ||
4246                                   parent->variant_type !=
4247                                   YAFFS_OBJECT_TYPE_DIRECTORY) {
4248                                hanging = 1;
4249                        } else if (yaffs_has_null_parent(dev, parent)) {
4250                                hanging = 0;
4251                        } else {
4252                                /*
4253                                 * Need to follow the parent chain to
4254                                 * see if it is hanging.
4255                                 */
4256                                hanging = 0;
4257                                depth_limit = 100;
4258
4259                                while (parent != dev->root_dir &&
4260                                       parent->parent &&
4261                                       parent->parent->variant_type ==
4262                                       YAFFS_OBJECT_TYPE_DIRECTORY &&
4263                                       depth_limit > 0) {
4264                                        parent = parent->parent;
4265                                        depth_limit--;
4266                                }
4267                                if (parent != dev->root_dir)
4268                                        hanging = 1;
4269                        }
4270                        if (hanging) {
4271                                yaffs_trace(YAFFS_TRACE_SCAN,
4272                                        "Hanging object %d moved to lost and found",
4273                                        obj->obj_id);
4274                                yaffs_add_obj_to_dir(dev->lost_n_found, obj);
4275                        }
4276                }
4277        }
4278}
4279
4280/*
4281 * Delete directory contents for cleaning up lost and found.
4282 */
4283static void yaffs_del_dir_contents(struct yaffs_obj *dir)
4284{
4285        struct yaffs_obj *obj;
4286        struct list_head *lh;
4287        struct list_head *n;
4288
4289        if (dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
4290                BUG();
4291
4292        list_for_each_safe(lh, n, &dir->variant.dir_variant.children) {
4293                obj = list_entry(lh, struct yaffs_obj, siblings);
4294                if (obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY)
4295                        yaffs_del_dir_contents(obj);
4296                yaffs_trace(YAFFS_TRACE_SCAN,
4297                        "Deleting lost_found object %d",
4298                        obj->obj_id);
4299                yaffs_unlink_obj(obj);
4300        }
4301}
4302
4303static void yaffs_empty_l_n_f(struct yaffs_dev *dev)
4304{
4305        yaffs_del_dir_contents(dev->lost_n_found);
4306}
4307
4308
4309struct yaffs_obj *yaffs_find_by_name(struct yaffs_obj *directory,
4310                                     const YCHAR *name)
4311{
4312        int sum;
4313        struct list_head *i;
4314        YCHAR buffer[YAFFS_MAX_NAME_LENGTH + 1];
4315        struct yaffs_obj *l;
4316
4317        if (!name)
4318                return NULL;
4319
4320        if (!directory) {
4321                yaffs_trace(YAFFS_TRACE_ALWAYS,
4322                        "tragedy: yaffs_find_by_name: null pointer directory"
4323                        );
4324                BUG();
4325                return NULL;
4326        }
4327        if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
4328                yaffs_trace(YAFFS_TRACE_ALWAYS,
4329                        "tragedy: yaffs_find_by_name: non-directory"
4330                        );
4331                BUG();
4332        }
4333
4334        sum = yaffs_calc_name_sum(name);
4335
4336        list_for_each(i, &directory->variant.dir_variant.children) {
4337                l = list_entry(i, struct yaffs_obj, siblings);
4338
4339                if (l->parent != directory)
4340                        BUG();
4341
4342                yaffs_check_obj_details_loaded(l);
4343
4344                /* Special case for lost-n-found */
4345                if (l->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
4346                        if (!yaffs_strcmp(name, YAFFS_LOSTNFOUND_NAME))
4347                                return l;
4348                } else if (l->sum == sum || l->hdr_chunk <= 0) {
4349                        /* LostnFound chunk called Objxxx
4350                         * Do a real check
4351                         */
4352                        yaffs_get_obj_name(l, buffer,
4353                                YAFFS_MAX_NAME_LENGTH + 1);
4354                        if (!yaffs_strncmp(name, buffer, YAFFS_MAX_NAME_LENGTH))
4355                                return l;
4356                }
4357        }
4358        return NULL;
4359}
4360
4361/* GetEquivalentObject dereferences any hard links to get to the
4362 * actual object.
4363 */
4364
4365struct yaffs_obj *yaffs_get_equivalent_obj(struct yaffs_obj *obj)
4366{
4367        if (obj && obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
4368                obj = obj->variant.hardlink_variant.equiv_obj;
4369                yaffs_check_obj_details_loaded(obj);
4370        }
4371        return obj;
4372}
4373
4374/*
4375 *  A note or two on object names.
4376 *  * If the object name is missing, we then make one up in the form objnnn
4377 *
4378 *  * ASCII names are stored in the object header's name field from byte zero
4379 *  * Unicode names are historically stored starting from byte zero.
4380 *
4381 * Then there are automatic Unicode names...
4382 * The purpose of these is to save names in a way that can be read as
4383 * ASCII or Unicode names as appropriate, thus allowing a Unicode and ASCII
4384 * system to share files.
4385 *
4386 * These automatic unicode are stored slightly differently...
4387 *  - If the name can fit in the ASCII character space then they are saved as
4388 *    ascii names as per above.
4389 *  - If the name needs Unicode then the name is saved in Unicode
4390 *    starting at oh->name[1].
4391
4392 */
4393static void yaffs_fix_null_name(struct yaffs_obj *obj, YCHAR *name,
4394                                int buffer_size)
4395{
4396        /* Create an object name if we could not find one. */
4397        if (yaffs_strnlen(name, YAFFS_MAX_NAME_LENGTH) == 0) {
4398                YCHAR local_name[20];
4399                YCHAR num_string[20];
4400                YCHAR *x = &num_string[19];
4401                unsigned v = obj->obj_id;
4402                num_string[19] = 0;
4403                while (v > 0) {
4404                        x--;
4405                        *x = '0' + (v % 10);
4406                        v /= 10;
4407                }
4408                /* make up a name */
4409                yaffs_strcpy(local_name, YAFFS_LOSTNFOUND_PREFIX);
4410                yaffs_strcat(local_name, x);
4411                yaffs_strncpy(name, local_name, buffer_size - 1);
4412        }
4413}
4414
4415int yaffs_get_obj_name(struct yaffs_obj *obj, YCHAR *name, int buffer_size)
4416{
4417        memset(name, 0, buffer_size * sizeof(YCHAR));
4418        yaffs_check_obj_details_loaded(obj);
4419        if (obj->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
4420                yaffs_strncpy(name, YAFFS_LOSTNFOUND_NAME, buffer_size - 1);
4421        } else if (obj->short_name[0]) {
4422                yaffs_strcpy(name, obj->short_name);
4423        } else if (obj->hdr_chunk > 0) {
4424                u8 *buffer = yaffs_get_temp_buffer(obj->my_dev);
4425
4426                struct yaffs_obj_hdr *oh = (struct yaffs_obj_hdr *)buffer;
4427
4428                memset(buffer, 0, obj->my_dev->data_bytes_per_chunk);
4429
4430                if (obj->hdr_chunk > 0) {
4431                        yaffs_rd_chunk_tags_nand(obj->my_dev,
4432                                                 obj->hdr_chunk,
4433                                                 buffer, NULL);
4434                }
4435                yaffs_load_name_from_oh(obj->my_dev, name, oh->name,
4436                                        buffer_size);
4437
4438                yaffs_release_temp_buffer(obj->my_dev, buffer);
4439        }
4440
4441        yaffs_fix_null_name(obj, name, buffer_size);
4442
4443        return yaffs_strnlen(name, YAFFS_MAX_NAME_LENGTH);
4444}
4445
4446loff_t yaffs_get_obj_length(struct yaffs_obj *obj)
4447{
4448        /* Dereference any hard linking */
4449        obj = yaffs_get_equivalent_obj(obj);
4450
4451        if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
4452                return obj->variant.file_variant.file_size;
4453        if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
4454                if (!obj->variant.symlink_variant.alias)
4455                        return 0;
4456                return yaffs_strnlen(obj->variant.symlink_variant.alias,
4457                                     YAFFS_MAX_ALIAS_LENGTH);
4458        } else {
4459                /* Only a directory should drop through to here */
4460                return obj->my_dev->data_bytes_per_chunk;
4461        }
4462}
4463
4464int yaffs_get_obj_link_count(struct yaffs_obj *obj)
4465{
4466        int count = 0;
4467        struct list_head *i;
4468
4469        if (!obj->unlinked)
4470                count++;        /* the object itself */
4471
4472        list_for_each(i, &obj->hard_links)
4473            count++;            /* add the hard links; */
4474
4475        return count;
4476}
4477
4478int yaffs_get_obj_inode(struct yaffs_obj *obj)
4479{
4480        obj = yaffs_get_equivalent_obj(obj);
4481
4482        return obj->obj_id;
4483}
4484
4485unsigned yaffs_get_obj_type(struct yaffs_obj *obj)
4486{
4487        obj = yaffs_get_equivalent_obj(obj);
4488
4489        switch (obj->variant_type) {
4490        case YAFFS_OBJECT_TYPE_FILE:
4491                return DT_REG;
4492                break;
4493        case YAFFS_OBJECT_TYPE_DIRECTORY:
4494                return DT_DIR;
4495                break;
4496        case YAFFS_OBJECT_TYPE_SYMLINK:
4497                return DT_LNK;
4498                break;
4499        case YAFFS_OBJECT_TYPE_HARDLINK:
4500                return DT_REG;
4501                break;
4502        case YAFFS_OBJECT_TYPE_SPECIAL:
4503                if (S_ISFIFO(obj->yst_mode))
4504                        return DT_FIFO;
4505                if (S_ISCHR(obj->yst_mode))
4506                        return DT_CHR;
4507                if (S_ISBLK(obj->yst_mode))
4508                        return DT_BLK;
4509                if (S_ISSOCK(obj->yst_mode))
4510                        return DT_SOCK;
4511                return DT_REG;
4512                break;
4513        default:
4514                return DT_REG;
4515                break;
4516        }
4517}
4518
4519YCHAR *yaffs_get_symlink_alias(struct yaffs_obj *obj)
4520{
4521        obj = yaffs_get_equivalent_obj(obj);
4522        if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK)
4523                return yaffs_clone_str(obj->variant.symlink_variant.alias);
4524        else
4525                return yaffs_clone_str(_Y(""));
4526}
4527
4528/*--------------------------- Initialisation code -------------------------- */
4529
4530static int yaffs_check_dev_fns(const struct yaffs_dev *dev)
4531{
4532        /* Common functions, gotta have */
4533        if (!dev->param.erase_fn || !dev->param.initialise_flash_fn)
4534                return 0;
4535
4536        /* Can use the "with tags" style interface for yaffs1 or yaffs2 */
4537        if (dev->param.write_chunk_tags_fn &&
4538            dev->param.read_chunk_tags_fn &&
4539            !dev->param.write_chunk_fn &&
4540            !dev->param.read_chunk_fn &&
4541            dev->param.bad_block_fn && dev->param.query_block_fn)
4542                return 1;
4543
4544        /* Can use the "spare" style interface for yaffs1 */
4545        if (!dev->param.is_yaffs2 &&
4546            !dev->param.write_chunk_tags_fn &&
4547            !dev->param.read_chunk_tags_fn &&
4548            dev->param.write_chunk_fn &&
4549            dev->param.read_chunk_fn &&
4550            !dev->param.bad_block_fn && !dev->param.query_block_fn)
4551                return 1;
4552
4553        return 0;               /* bad */
4554}
4555
4556static int yaffs_create_initial_dir(struct yaffs_dev *dev)
4557{
4558        /* Initialise the unlinked, deleted, root and lost+found directories */
4559        dev->lost_n_found = dev->root_dir = NULL;
4560        dev->unlinked_dir = dev->del_dir = NULL;
4561        dev->unlinked_dir =
4562            yaffs_create_fake_dir(dev, YAFFS_OBJECTID_UNLINKED, S_IFDIR);
4563        dev->del_dir =
4564            yaffs_create_fake_dir(dev, YAFFS_OBJECTID_DELETED, S_IFDIR);
4565        dev->root_dir =
4566            yaffs_create_fake_dir(dev, YAFFS_OBJECTID_ROOT,
4567                                  YAFFS_ROOT_MODE | S_IFDIR);
4568        dev->lost_n_found =
4569            yaffs_create_fake_dir(dev, YAFFS_OBJECTID_LOSTNFOUND,
4570                                  YAFFS_LOSTNFOUND_MODE | S_IFDIR);
4571
4572        if (dev->lost_n_found && dev->root_dir && dev->unlinked_dir
4573            && dev->del_dir) {
4574                yaffs_add_obj_to_dir(dev->root_dir, dev->lost_n_found);
4575                return YAFFS_OK;
4576        }
4577        return YAFFS_FAIL;
4578}
4579
4580int yaffs_guts_initialise(struct yaffs_dev *dev)
4581{
4582        int init_failed = 0;
4583        unsigned x;
4584        int bits;
4585
4586        yaffs_trace(YAFFS_TRACE_TRACING, "yaffs: yaffs_guts_initialise()");
4587
4588        /* Check stuff that must be set */
4589
4590        if (!dev) {
4591                yaffs_trace(YAFFS_TRACE_ALWAYS,
4592                        "yaffs: Need a device"
4593                        );
4594                return YAFFS_FAIL;
4595        }
4596
4597        if (dev->is_mounted) {
4598                yaffs_trace(YAFFS_TRACE_ALWAYS, "device already mounted");
4599                return YAFFS_FAIL;
4600        }
4601
4602        dev->internal_start_block = dev->param.start_block;
4603        dev->internal_end_block = dev->param.end_block;
4604        dev->block_offset = 0;
4605        dev->chunk_offset = 0;
4606        dev->n_free_chunks = 0;
4607
4608        dev->gc_block = 0;
4609
4610        if (dev->param.start_block == 0) {
4611                dev->internal_start_block = dev->param.start_block + 1;
4612                dev->internal_end_block = dev->param.end_block + 1;
4613                dev->block_offset = 1;
4614                dev->chunk_offset = dev->param.chunks_per_block;
4615        }
4616
4617        /* Check geometry parameters. */
4618
4619        if ((!dev->param.inband_tags && dev->param.is_yaffs2 &&
4620                dev->param.total_bytes_per_chunk < 1024) ||
4621                (!dev->param.is_yaffs2 &&
4622                        dev->param.total_bytes_per_chunk < 512) ||
4623                (dev->param.inband_tags && !dev->param.is_yaffs2) ||
4624                 dev->param.chunks_per_block < 2 ||
4625                 dev->param.n_reserved_blocks < 2 ||
4626                dev->internal_start_block <= 0 ||
4627                dev->internal_end_block <= 0 ||
4628                dev->internal_end_block <=
4629                (dev->internal_start_block + dev->param.n_reserved_blocks + 2)
4630                ) {
4631                /* otherwise it is too small */
4632                yaffs_trace(YAFFS_TRACE_ALWAYS,
4633                        "NAND geometry problems: chunk size %d, type is yaffs%s, inband_tags %d ",
4634                        dev->param.total_bytes_per_chunk,
4635                        dev->param.is_yaffs2 ? "2" : "",
4636                        dev->param.inband_tags);
4637                return YAFFS_FAIL;
4638        }
4639
4640        if (yaffs_init_nand(dev) != YAFFS_OK) {
4641                yaffs_trace(YAFFS_TRACE_ALWAYS, "InitialiseNAND failed");
4642                return YAFFS_FAIL;
4643        }
4644
4645        /* Sort out space for inband tags, if required */
4646        if (dev->param.inband_tags)
4647                dev->data_bytes_per_chunk =
4648                    dev->param.total_bytes_per_chunk -
4649                    sizeof(struct yaffs_packed_tags2_tags_only);
4650        else
4651                dev->data_bytes_per_chunk = dev->param.total_bytes_per_chunk;
4652
4653        /* Got the right mix of functions? */
4654        if (!yaffs_check_dev_fns(dev)) {
4655                /* Function missing */
4656                yaffs_trace(YAFFS_TRACE_ALWAYS,
4657                        "device function(s) missing or wrong");
4658
4659                return YAFFS_FAIL;
4660        }
4661
4662        /* Finished with most checks. Further checks happen later on too. */
4663
4664        dev->is_mounted = 1;
4665
4666        /* OK now calculate a few things for the device */
4667
4668        /*
4669         *  Calculate all the chunk size manipulation numbers:
4670         */
4671        x = dev->data_bytes_per_chunk;
4672        /* We always use dev->chunk_shift and dev->chunk_div */
4673        dev->chunk_shift = calc_shifts(x);
4674        x >>= dev->chunk_shift;
4675        dev->chunk_div = x;
4676        /* We only use chunk mask if chunk_div is 1 */
4677        dev->chunk_mask = (1 << dev->chunk_shift) - 1;
4678
4679        /*
4680         * Calculate chunk_grp_bits.
4681         * We need to find the next power of 2 > than internal_end_block
4682         */
4683
4684        x = dev->param.chunks_per_block * (dev->internal_end_block + 1);
4685
4686        bits = calc_shifts_ceiling(x);
4687
4688        /* Set up tnode width if wide tnodes are enabled. */
4689        if (!dev->param.wide_tnodes_disabled) {
4690                /* bits must be even so that we end up with 32-bit words */
4691                if (bits & 1)
4692                        bits++;
4693                if (bits < 16)
4694                        dev->tnode_width = 16;
4695                else
4696                        dev->tnode_width = bits;
4697        } else {
4698                dev->tnode_width = 16;
4699        }
4700
4701        dev->tnode_mask = (1 << dev->tnode_width) - 1;
4702
4703        /* Level0 Tnodes are 16 bits or wider (if wide tnodes are enabled),
4704         * so if the bitwidth of the
4705         * chunk range we're using is greater than 16 we need
4706         * to figure out chunk shift and chunk_grp_size
4707         */
4708
4709        if (bits <= dev->tnode_width)
4710                dev->chunk_grp_bits = 0;
4711        else
4712                dev->chunk_grp_bits = bits - dev->tnode_width;
4713
4714        dev->tnode_size = (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8;
4715        if (dev->tnode_size < sizeof(struct yaffs_tnode))
4716                dev->tnode_size = sizeof(struct yaffs_tnode);
4717
4718        dev->chunk_grp_size = 1 << dev->chunk_grp_bits;
4719
4720        if (dev->param.chunks_per_block < dev->chunk_grp_size) {
4721                /* We have a problem because the soft delete won't work if
4722                 * the chunk group size > chunks per block.
4723                 * This can be remedied by using larger "virtual blocks".
4724                 */
4725                yaffs_trace(YAFFS_TRACE_ALWAYS, "chunk group too large");
4726
4727                return YAFFS_FAIL;
4728        }
4729
4730        /* Finished verifying the device, continue with initialisation */
4731
4732        /* More device initialisation */
4733        dev->all_gcs = 0;
4734        dev->passive_gc_count = 0;
4735        dev->oldest_dirty_gc_count = 0;
4736        dev->bg_gcs = 0;
4737        dev->gc_block_finder = 0;
4738        dev->buffered_block = -1;
4739        dev->doing_buffered_block_rewrite = 0;
4740        dev->n_deleted_files = 0;
4741        dev->n_bg_deletions = 0;
4742        dev->n_unlinked_files = 0;
4743        dev->n_ecc_fixed = 0;
4744        dev->n_ecc_unfixed = 0;
4745        dev->n_tags_ecc_fixed = 0;
4746        dev->n_tags_ecc_unfixed = 0;
4747        dev->n_erase_failures = 0;
4748        dev->n_erased_blocks = 0;
4749        dev->gc_disable = 0;
4750        dev->has_pending_prioritised_gc = 1;
4751                /* Assume the worst for now, will get fixed on first GC */
4752        INIT_LIST_HEAD(&dev->dirty_dirs);
4753        dev->oldest_dirty_seq = 0;
4754        dev->oldest_dirty_block = 0;
4755
4756        /* Initialise temporary buffers and caches. */
4757        if (!yaffs_init_tmp_buffers(dev))
4758                init_failed = 1;
4759
4760        dev->cache = NULL;
4761        dev->gc_cleanup_list = NULL;
4762
4763        if (!init_failed && dev->param.n_caches > 0) {
4764                int i;
4765                void *buf;
4766                int cache_bytes =
4767                    dev->param.n_caches * sizeof(struct yaffs_cache);
4768
4769                if (dev->param.n_caches > YAFFS_MAX_SHORT_OP_CACHES)
4770                        dev->param.n_caches = YAFFS_MAX_SHORT_OP_CACHES;
4771
4772                dev->cache = kmalloc(cache_bytes, GFP_NOFS);
4773
4774                buf = (u8 *) dev->cache;
4775
4776                if (dev->cache)
4777                        memset(dev->cache, 0, cache_bytes);
4778
4779                for (i = 0; i < dev->param.n_caches && buf; i++) {
4780                        dev->cache[i].object = NULL;
4781                        dev->cache[i].last_use = 0;
4782                        dev->cache[i].dirty = 0;
4783                        dev->cache[i].data = buf =
4784                            kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
4785                }
4786                if (!buf)
4787                        init_failed = 1;
4788
4789                dev->cache_last_use = 0;
4790        }
4791
4792        dev->cache_hits = 0;
4793
4794        if (!init_failed) {
4795                dev->gc_cleanup_list =
4796                    kmalloc(dev->param.chunks_per_block * sizeof(u32),
4797                                        GFP_NOFS);
4798                if (!dev->gc_cleanup_list)
4799                        init_failed = 1;
4800        }
4801
4802        if (dev->param.is_yaffs2)
4803                dev->param.use_header_file_size = 1;
4804
4805        if (!init_failed && !yaffs_init_blocks(dev))
4806                init_failed = 1;
4807
4808        yaffs_init_tnodes_and_objs(dev);
4809
4810        if (!init_failed && !yaffs_create_initial_dir(dev))
4811                init_failed = 1;
4812
4813        if (!init_failed && dev->param.is_yaffs2 &&
4814                !dev->param.disable_summary &&
4815                !yaffs_summary_init(dev))
4816                init_failed = 1;
4817
4818        if (!init_failed) {
4819                /* Now scan the flash. */
4820                if (dev->param.is_yaffs2) {
4821                        if (yaffs2_checkpt_restore(dev)) {
4822                                yaffs_check_obj_details_loaded(dev->root_dir);
4823                                yaffs_trace(YAFFS_TRACE_CHECKPOINT |
4824                                        YAFFS_TRACE_MOUNT,
4825                                        "yaffs: restored from checkpoint"
4826                                        );
4827                        } else {
4828
4829                                /* Clean up the mess caused by an aborted
4830                                 * checkpoint load then scan backwards.
4831                                 */
4832                                yaffs_deinit_blocks(dev);
4833
4834                                yaffs_deinit_tnodes_and_objs(dev);
4835
4836                                dev->n_erased_blocks = 0;
4837                                dev->n_free_chunks = 0;
4838                                dev->alloc_block = -1;
4839                                dev->alloc_page = -1;
4840                                dev->n_deleted_files = 0;
4841                                dev->n_unlinked_files = 0;
4842                                dev->n_bg_deletions = 0;
4843
4844                                if (!init_failed && !yaffs_init_blocks(dev))
4845                                        init_failed = 1;
4846
4847                                yaffs_init_tnodes_and_objs(dev);
4848
4849                                if (!init_failed
4850                                    && !yaffs_create_initial_dir(dev))
4851                                        init_failed = 1;
4852
4853                                if (!init_failed && !yaffs2_scan_backwards(dev))
4854                                        init_failed = 1;
4855                        }
4856                } else if (!yaffs1_scan(dev)) {
4857                        init_failed = 1;
4858                }
4859
4860                yaffs_strip_deleted_objs(dev);
4861                yaffs_fix_hanging_objs(dev);
4862                if (dev->param.empty_lost_n_found)
4863                        yaffs_empty_l_n_f(dev);
4864        }
4865
4866        if (init_failed) {
4867                /* Clean up the mess */
4868                yaffs_trace(YAFFS_TRACE_TRACING,
4869                  "yaffs: yaffs_guts_initialise() aborted.");
4870
4871                yaffs_deinitialise(dev);
4872                return YAFFS_FAIL;
4873        }
4874
4875        /* Zero out stats */
4876        dev->n_page_reads = 0;
4877        dev->n_page_writes = 0;
4878        dev->n_erasures = 0;
4879        dev->n_gc_copies = 0;
4880        dev->n_retried_writes = 0;
4881
4882        dev->n_retired_blocks = 0;
4883
4884        yaffs_verify_free_chunks(dev);
4885        yaffs_verify_blocks(dev);
4886
4887        /* Clean up any aborted checkpoint data */
4888        if (!dev->is_checkpointed && dev->blocks_in_checkpt > 0)
4889                yaffs2_checkpt_invalidate(dev);
4890
4891        yaffs_trace(YAFFS_TRACE_TRACING,
4892          "yaffs: yaffs_guts_initialise() done.");
4893        return YAFFS_OK;
4894}
4895
4896void yaffs_deinitialise(struct yaffs_dev *dev)
4897{
4898        if (dev->is_mounted) {
4899                int i;
4900
4901                yaffs_deinit_blocks(dev);
4902                yaffs_deinit_tnodes_and_objs(dev);
4903                yaffs_summary_deinit(dev);
4904
4905                if (dev->param.n_caches > 0 && dev->cache) {
4906
4907                        for (i = 0; i < dev->param.n_caches; i++) {
4908                                kfree(dev->cache[i].data);
4909                                dev->cache[i].data = NULL;
4910                        }
4911
4912                        kfree(dev->cache);
4913                        dev->cache = NULL;
4914                }
4915
4916                kfree(dev->gc_cleanup_list);
4917
4918                for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++)
4919                        kfree(dev->temp_buffer[i].buffer);
4920
4921                dev->is_mounted = 0;
4922
4923                if (dev->param.deinitialise_flash_fn)
4924                        dev->param.deinitialise_flash_fn(dev);
4925        }
4926}
4927
4928int yaffs_count_free_chunks(struct yaffs_dev *dev)
4929{
4930        int n_free = 0;
4931        int b;
4932        struct yaffs_block_info *blk;
4933
4934        blk = dev->block_info;
4935        for (b = dev->internal_start_block; b <= dev->internal_end_block; b++) {
4936                switch (blk->block_state) {
4937                case YAFFS_BLOCK_STATE_EMPTY:
4938                case YAFFS_BLOCK_STATE_ALLOCATING:
4939                case YAFFS_BLOCK_STATE_COLLECTING:
4940                case YAFFS_BLOCK_STATE_FULL:
4941                        n_free +=
4942                            (dev->param.chunks_per_block - blk->pages_in_use +
4943                             blk->soft_del_pages);
4944                        break;
4945                default:
4946                        break;
4947                }
4948                blk++;
4949        }
4950        return n_free;
4951}
4952
4953int yaffs_get_n_free_chunks(struct yaffs_dev *dev)
4954{
4955        /* This is what we report to the outside world */
4956        int n_free;
4957        int n_dirty_caches;
4958        int blocks_for_checkpt;
4959        int i;
4960
4961        n_free = dev->n_free_chunks;
4962        n_free += dev->n_deleted_files;
4963
4964        /* Now count and subtract the number of dirty chunks in the cache. */
4965
4966        for (n_dirty_caches = 0, i = 0; i < dev->param.n_caches; i++) {
4967                if (dev->cache[i].dirty)
4968                        n_dirty_caches++;
4969        }
4970
4971        n_free -= n_dirty_caches;
4972
4973        n_free -=
4974            ((dev->param.n_reserved_blocks + 1) * dev->param.chunks_per_block);
4975
4976        /* Now figure checkpoint space and report that... */
4977        blocks_for_checkpt = yaffs_calc_checkpt_blocks_required(dev);
4978
4979        n_free -= (blocks_for_checkpt * dev->param.chunks_per_block);
4980
4981        if (n_free < 0)
4982                n_free = 0;
4983
4984        return n_free;
4985}
4986
4987/*\
4988 * Marshalling functions to get loff_t file sizes into aand out of
4989 * object headers.
4990 */
4991void yaffs_oh_size_load(struct yaffs_obj_hdr *oh, loff_t fsize)
4992{
4993        oh->file_size_low = (fsize & 0xFFFFFFFF);
4994        oh->file_size_high = ((fsize >> 32) & 0xFFFFFFFF);
4995}
4996
4997loff_t yaffs_oh_to_size(struct yaffs_obj_hdr *oh)
4998{
4999        loff_t retval;
5000
5001        if (~(oh->file_size_high))
5002                retval = (((loff_t) oh->file_size_high) << 32) |
5003                        (((loff_t) oh->file_size_low) & 0xFFFFFFFF);
5004        else
5005                retval = (loff_t) oh->file_size_low;
5006
5007        return retval;
5008}
5009