yaffs_yaffs2.c

   1 /*
   2  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
   3  *
   4  * Copyright (C) 2002-2018 Aleph One Ltd.
   5  *
   6  * Created by Charles Manning <charles@aleph1.co.uk>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include "yaffs_guts.h"
  14 #include "yaffs_trace.h"
  15 #include "yaffs_yaffs2.h"
  16 #include "yaffs_checkptrw.h"
  17 #include "yaffs_bitmap.h"
  18 #include "yaffs_nand.h"
  19 #include "yaffs_getblockinfo.h"
  20 #include "yaffs_verify.h"
  21 #include "yaffs_attribs.h"
  22 #include "yaffs_summary.h"
  23 #include "yaffs_endian.h"
  24
  25 /*
  26  * Checkpoints are really no benefit on very small partitions.
  27  *
  28  * To save space on small partitions don't bother with checkpoints unless
  29  * the partition is at least this big.
  30  */
  31 #define YAFFS_CHECKPOINT_MIN_BLOCKS 60
  32 #define YAFFS_SMALL_HOLE_THRESHOLD 4
  33
  34 /*
  35  * Oldest Dirty Sequence Number handling.
  36  */
  37
  38 /* yaffs_calc_oldest_dirty_seq()
  39  * yaffs2_find_oldest_dirty_seq()
  40  * Calculate the oldest dirty sequence number if we don't know it.
  41  */
  42 void yaffs_calc_oldest_dirty_seq(struct yaffs_dev *dev)
  43 {
  44         u32 i;
  45         unsigned seq;
  46         unsigned block_no = 0;
  47         struct yaffs_block_info *b;
  48
  49         if (!dev->param.is_yaffs2)
  50                 return;
  51
  52         /* Find the oldest dirty sequence number. */
  53         seq = dev->seq_number + 1;
  54         b = dev->block_info;
  55         for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
  56                 if (b->block_state == YAFFS_BLOCK_STATE_FULL &&
  57                     (u32)(b->pages_in_use - b->soft_del_pages) <
  58                     dev->param.chunks_per_block &&
  59                     b->seq_number < seq) {
  60                         seq = b->seq_number;
  61                         block_no = i;
  62                 }
  63                 b++;
  64         }
  65
  66         if (block_no) {
  67                 dev->oldest_dirty_seq = seq;
  68                 dev->oldest_dirty_block = block_no;
  69         }
  70 }
  71
  72 void yaffs2_find_oldest_dirty_seq(struct yaffs_dev *dev)
  73 {
  74         if (!dev->param.is_yaffs2)
  75                 return;
  76
  77         if (!dev->oldest_dirty_seq)
  78                 yaffs_calc_oldest_dirty_seq(dev);
  79 }
  80
  81 /*
  82  * yaffs_clear_oldest_dirty_seq()
  83  * Called when a block is erased or marked bad. (ie. when its seq_number
  84  * becomes invalid). If the value matches the oldest then we clear
  85  * dev->oldest_dirty_seq to force its recomputation.
  86  */
  87 void yaffs2_clear_oldest_dirty_seq(struct yaffs_dev *dev,
  88                                    struct yaffs_block_info *bi)
  89 {
  90
  91         if (!dev->param.is_yaffs2)
  92                 return;
  93
  94         if (!bi || bi->seq_number == dev->oldest_dirty_seq) {
  95                 dev->oldest_dirty_seq = 0;
  96                 dev->oldest_dirty_block = 0;
  97         }
  98 }
  99
 100 /*
 101  * yaffs2_update_oldest_dirty_seq()
 102  * Update the oldest dirty sequence number whenever we dirty a block.
 103  * Only do this if the oldest_dirty_seq is actually being tracked.
 104  */
 105 void yaffs2_update_oldest_dirty_seq(struct yaffs_dev *dev, unsigned block_no,
 106                                     struct yaffs_block_info *bi)
 107 {
 108         if (!dev->param.is_yaffs2)
 109                 return;
 110
 111         if (dev->oldest_dirty_seq) {
 112                 if (dev->oldest_dirty_seq > bi->seq_number) {
 113                         dev->oldest_dirty_seq = bi->seq_number;
 114                         dev->oldest_dirty_block = block_no;
 115                 }
 116         }
 117 }
 118
 119 int yaffs_block_ok_for_gc(struct yaffs_dev *dev, struct yaffs_block_info *bi)
 120 {
 121
 122         if (!dev->param.is_yaffs2)
 123                 return 1;       /* disqualification only applies to yaffs2. */
 124
 125         if (!bi->has_shrink_hdr)
 126                 return 1;       /* can gc */
 127
 128         yaffs2_find_oldest_dirty_seq(dev);
 129
 130         /* Can't do gc of this block if there are any blocks older than this
 131          * one that have discarded pages.
 132          */
 133         return (bi->seq_number <= dev->oldest_dirty_seq);
 134 }
 135
 136 /*
 137  * yaffs2_find_refresh_block()
 138  * periodically finds the oldest full block by sequence number for refreshing.
 139  * Only for yaffs2.
 140  */
 141 u32 yaffs2_find_refresh_block(struct yaffs_dev *dev)
 142 {
 143         u32 b;
 144         u32 oldest = 0;
 145         u32 oldest_seq = 0;
 146         struct yaffs_block_info *bi;
 147
 148         if (!dev->param.is_yaffs2)
 149                 return oldest;
 150
 151         /*
 152          * If refresh period < 10 then refreshing is disabled.
 153          */
 154         if (dev->param.refresh_period < 10)
 155                 return oldest;
 156
 157         /*
 158          * Fix broken values.
 159          */
 160         if (dev->refresh_skip > dev->param.refresh_period)
 161                 dev->refresh_skip = dev->param.refresh_period;
 162
 163         if (dev->refresh_skip > 0)
 164                 return oldest;
 165
 166         /*
 167          * Refresh skip is now zero.
 168          * We'll do a refresh this time around....
 169          * Update the refresh skip and find the oldest block.
 170          */
 171         dev->refresh_skip = dev->param.refresh_period;
 172         dev->refresh_count++;
 173         bi = dev->block_info;
 174         for (b = dev->internal_start_block; b <= dev->internal_end_block; b++) {
 175
 176                 if (bi->block_state == YAFFS_BLOCK_STATE_FULL) {
 177
 178                         if (oldest < 1 || bi->seq_number < oldest_seq) {
 179                                 oldest = b;
 180                                 oldest_seq = bi->seq_number;
 181                         }
 182                 }
 183                 bi++;
 184         }
 185
 186         if (oldest > 0) {
 187                 yaffs_trace(YAFFS_TRACE_GC,
 188                         "GC refresh count %d selected block %d with seq_number %d",
 189                         dev->refresh_count, oldest, oldest_seq);
 190         }
 191
 192         return oldest;
 193 }
 194
 195 int yaffs2_checkpt_required(struct yaffs_dev *dev)
 196 {
 197         int nblocks;
 198
 199         if (!dev->param.is_yaffs2)
 200                 return 0;
 201
 202         nblocks = dev->internal_end_block - dev->internal_start_block + 1;
 203
 204         return !dev->param.skip_checkpt_wr &&
 205             !dev->read_only && (nblocks >= YAFFS_CHECKPOINT_MIN_BLOCKS);
 206 }
 207
 208 int yaffs_calc_checkpt_blocks_required(struct yaffs_dev *dev)
 209 {
 210         int retval;
 211         int n_bytes = 0;
 212         int n_blocks;
 213         int dev_blocks;
 214
 215         if (!dev->param.is_yaffs2)
 216                 return 0;
 217
 218         if (!dev->checkpoint_blocks_required && yaffs2_checkpt_required(dev)) {
 219                 /* Not a valid value so recalculate */
 220                 dev_blocks = dev->param.end_block - dev->param.start_block + 1;
 221                 n_bytes += sizeof(struct yaffs_checkpt_validity);
 222                 n_bytes += sizeof(struct yaffs_checkpt_dev);
 223                 n_bytes += dev_blocks * sizeof(struct yaffs_block_info);
 224                 n_bytes += dev_blocks * dev->chunk_bit_stride;
 225                 n_bytes +=
 226                     (sizeof(struct yaffs_checkpt_obj) + sizeof(u32)) *
 227                     dev->n_obj;
 228                 n_bytes += (dev->tnode_size + sizeof(u32)) * dev->n_tnodes;
 229                 n_bytes += sizeof(struct yaffs_checkpt_validity);
 230                 n_bytes += sizeof(u32); /* checksum */
 231
 232                 /* Round up and add 2 blocks to allow for some bad blocks,
 233                  * so add 3 */
 234
 235                 n_blocks =
 236                     (n_bytes /
 237                      (dev->data_bytes_per_chunk *
 238                       dev->param.chunks_per_block)) + 3;
 239
 240                 dev->checkpoint_blocks_required = n_blocks;
 241         }
 242
 243         retval = dev->checkpoint_blocks_required - dev->blocks_in_checkpt;
 244         if (retval < 0)
 245                 retval = 0;
 246         return retval;
 247 }
 248
 249 /*--------------------- Checkpointing --------------------*/
 250
 251 static void yaffs2_do_endian_validity_marker(struct yaffs_dev *dev,
 252                                              struct yaffs_checkpt_validity *v)
 253 {
 254
 255         if (!dev->swap_endian)
 256                 return;
 257         v->struct_type = swap_s32(v->struct_type);
 258         v->magic = swap_u32(v->magic);
 259         v->version = swap_u32(v->version);
 260         v->head = swap_u32(v->head);
 261 }
 262
 263 static int yaffs2_wr_checkpt_validity_marker(struct yaffs_dev *dev, int head)
 264 {
 265         struct yaffs_checkpt_validity cp;
 266
 267         memset(&cp, 0, sizeof(cp));
 268
 269         cp.struct_type = sizeof(cp);
 270         cp.magic = YAFFS_MAGIC;
 271         cp.version = YAFFS_CHECKPOINT_VERSION;
 272         cp.head = (head) ? 1 : 0;
 273
 274         yaffs2_do_endian_validity_marker(dev, &cp);
 275
 276         return (yaffs2_checkpt_wr(dev, &cp, sizeof(cp)) == sizeof(cp)) ? 1 : 0;
 277 }
 278
 279 static int yaffs2_rd_checkpt_validity_marker(struct yaffs_dev *dev, int head)
 280 {
 281         struct yaffs_checkpt_validity cp;
 282         int ok;
 283
 284         ok = (yaffs2_checkpt_rd(dev, &cp, sizeof(cp)) == sizeof(cp));
 285         yaffs2_do_endian_validity_marker(dev, &cp);
 286
 287         if (ok)
 288                 ok = (cp.struct_type == sizeof(cp)) &&
 289                     (cp.magic == YAFFS_MAGIC) &&
 290                     (cp.version == YAFFS_CHECKPOINT_VERSION) &&
 291                     (cp.head == ((head) ? 1 : 0));
 292         return ok ? 1 : 0;
 293 }
 294
 295 static void yaffs2_dev_to_checkpt_dev(struct yaffs_checkpt_dev *cp,
 296                                       struct yaffs_dev *dev)
 297 {
 298         cp->struct_type = sizeof(*cp);
 299
 300         cp->n_erased_blocks = dev->n_erased_blocks;
 301         cp->alloc_block = dev->alloc_block;
 302         cp->alloc_page = dev->alloc_page;
 303         cp->n_free_chunks = dev->n_free_chunks;
 304
 305         cp->n_deleted_files = dev->n_deleted_files;
 306         cp->n_unlinked_files = dev->n_unlinked_files;
 307         cp->n_bg_deletions = dev->n_bg_deletions;
 308         cp->seq_number = dev->seq_number;
 309
 310 }
 311
 312 static void yaffs_checkpt_dev_to_dev(struct yaffs_dev *dev,
 313                                      struct yaffs_checkpt_dev *cp)
 314 {
 315         dev->n_erased_blocks = cp->n_erased_blocks;
 316         dev->alloc_block = cp->alloc_block;
 317         dev->alloc_page = cp->alloc_page;
 318         dev->n_free_chunks = cp->n_free_chunks;
 319
 320         dev->n_deleted_files = cp->n_deleted_files;
 321         dev->n_unlinked_files = cp->n_unlinked_files;
 322         dev->n_bg_deletions = cp->n_bg_deletions;
 323         dev->seq_number = cp->seq_number;
 324 }
 325
 326 static void yaffs2_do_endian_checkpt_dev(struct yaffs_dev *dev,
 327                                      struct yaffs_checkpt_dev *cp)
 328 {
 329         if (!dev->swap_endian)
 330                 return;
 331         cp->struct_type = swap_s32(cp->struct_type);
 332         cp->n_erased_blocks = swap_s32(cp->n_erased_blocks);
 333         cp->alloc_block = swap_s32(cp->alloc_block);
 334         cp->alloc_page = swap_u32(cp->alloc_page);
 335         cp->n_free_chunks = swap_s32(cp->n_free_chunks);
 336         cp->n_deleted_files = swap_s32(cp->n_deleted_files);
 337         cp->n_unlinked_files = swap_s32(cp->n_unlinked_files);
 338         cp->n_bg_deletions = swap_s32(cp->n_bg_deletions);
 339 }
 340
 341 static int yaffs2_wr_checkpt_dev(struct yaffs_dev *dev)
 342 {
 343         struct yaffs_checkpt_dev cp;
 344         u32 n_bytes;
 345         u32 n_blocks = dev->internal_end_block - dev->internal_start_block + 1;
 346         int ok;
 347         u32 i;
 348         union yaffs_block_info_union bu;
 349
 350         /* Write device runtime values */
 351         yaffs2_dev_to_checkpt_dev(&cp, dev);
 352         yaffs2_do_endian_checkpt_dev(dev, &cp);
 353
 354         ok = (yaffs2_checkpt_wr(dev, &cp, sizeof(cp)) == sizeof(cp));
 355         if (!ok)
 356                 return 0;
 357
 358         /* Write block info. */
 359         if (!dev->swap_endian) {
 360                 n_bytes = n_blocks * sizeof(struct yaffs_block_info);
 361                 ok = (yaffs2_checkpt_wr(dev, dev->block_info, n_bytes) ==
 362                         (int)n_bytes);
 363         } else {
 364                 /*
 365                  * Need to swap the endianisms. We can't do this in place
 366                  * since that would damage live data,
 367                  * so write one block info at a time using a copy.
 368                  */
 369                 for (i = 0; i < n_blocks && ok; i++) {
 370                         bu.bi = dev->block_info[i];
 371                         bu.as_u32[0] = swap_u32(bu.as_u32[0]);
 372                         bu.as_u32[1] = swap_u32(bu.as_u32[1]);
 373                         ok = (yaffs2_checkpt_wr(dev, &bu, sizeof(bu)) == sizeof(bu));
 374                 }
 375         }
 376
 377         if (!ok)
 378                 return 0;
 379
 380         /*
 381          * Write chunk bits. Chunk bits are in bytes so
 382          * no endian conversion is needed.
 383          */
 384         n_bytes = n_blocks * dev->chunk_bit_stride;
 385         ok = (yaffs2_checkpt_wr(dev, dev->chunk_bits, n_bytes) ==
 386                 (int)n_bytes);
 387
 388         return ok ? 1 : 0;
 389 }
 390
 391 static int yaffs2_rd_checkpt_dev(struct yaffs_dev *dev)
 392 {
 393         struct yaffs_checkpt_dev cp;
 394         u32 n_bytes;
 395         u32 n_blocks =
 396             (dev->internal_end_block - dev->internal_start_block + 1);
 397         int ok;
 398
 399         ok = (yaffs2_checkpt_rd(dev, &cp, sizeof(cp)) == sizeof(cp));
 400         if (!ok)
 401                 return 0;
 402         yaffs2_do_endian_checkpt_dev(dev, &cp);
 403
 404         if (cp.struct_type != sizeof(cp))
 405                 return 0;
 406
 407         yaffs_checkpt_dev_to_dev(dev, &cp);
 408
 409         n_bytes = n_blocks * sizeof(struct yaffs_block_info);
 410
 411         ok = (yaffs2_checkpt_rd(dev, dev->block_info, n_bytes) ==
 412                 (int)n_bytes);
 413
 414         if (!ok)
 415                 return 0;
 416
 417         if (dev->swap_endian) {
 418                 /* The block info can just be handled as a list of u32s. */
 419                 u32 *as_u32 = (u32 *) dev->block_info;
 420                 u32 n_u32s = n_bytes/sizeof(u32);
 421                 u32 i;
 422
 423                 for (i=0; i < n_u32s; i++)
 424                         as_u32[i] = swap_u32(as_u32[i]);
 425         }
 426
 427         n_bytes = n_blocks * dev->chunk_bit_stride;
 428
 429         ok = (yaffs2_checkpt_rd(dev, dev->chunk_bits, n_bytes) ==
 430                 (int)n_bytes);
 431
 432
 433         return ok ? 1 : 0;
 434 }
 435
 436
 437 static void yaffs2_checkpt_obj_bit_assign(struct yaffs_checkpt_obj *cp,
 438                                           int bit_offset,
 439                                           int bit_width,
 440                                           u32 value)
 441 {
 442         u32 and_mask;
 443
 444         and_mask = ((1<<bit_width)-1) << bit_offset;
 445
 446         cp->bit_field &= ~and_mask;
 447         cp->bit_field |= ((value << bit_offset) & and_mask);
 448 }
 449
 450 static u32 yaffs2_checkpt_obj_bit_get(struct yaffs_checkpt_obj *cp,
 451                                       int bit_offset,
 452                                       int bit_width)
 453 {
 454         u32 and_mask;
 455
 456         and_mask = ((1<<bit_width)-1);
 457
 458         return (cp->bit_field >> bit_offset) & and_mask;
 459 }
 460
 461 static void yaffs2_obj_checkpt_obj(struct yaffs_checkpt_obj *cp,
 462                                    struct yaffs_obj *obj)
 463 {
 464         cp->obj_id = obj->obj_id;
 465         cp->parent_id = (obj->parent) ? obj->parent->obj_id : 0;
 466         cp->hdr_chunk = obj->hdr_chunk;
 467
 468         yaffs2_checkpt_obj_bit_assign(cp, CHECKPOINT_VARIANT_BITS, obj->variant_type);
 469         yaffs2_checkpt_obj_bit_assign(cp, CHECKPOINT_DELETED_BITS, obj->deleted);
 470         yaffs2_checkpt_obj_bit_assign(cp, CHECKPOINT_SOFT_DEL_BITS, obj->soft_del);
 471         yaffs2_checkpt_obj_bit_assign(cp, CHECKPOINT_UNLINKED_BITS, obj->unlinked);
 472         yaffs2_checkpt_obj_bit_assign(cp, CHECKPOINT_FAKE_BITS, obj->fake);
 473         yaffs2_checkpt_obj_bit_assign(cp, CHECKPOINT_RENAME_ALLOWED_BITS, obj->rename_allowed);
 474         yaffs2_checkpt_obj_bit_assign(cp, CHECKPOINT_UNLINK_ALLOWED_BITS, obj->unlink_allowed);
 475         yaffs2_checkpt_obj_bit_assign(cp, CHECKPOINT_SERIAL_BITS, obj->serial);
 476
 477         cp->n_data_chunks = obj->n_data_chunks;
 478
 479         if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
 480                 cp->size_or_equiv_obj = obj->variant.file_variant.file_size;
 481         else if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK)
 482                 cp->size_or_equiv_obj = obj->variant.hardlink_variant.equiv_id;
 483 }
 484
 485 static int yaffs2_checkpt_obj_to_obj(struct yaffs_obj *obj,
 486                                      struct yaffs_checkpt_obj *cp)
 487 {
 488         struct yaffs_obj *parent;
 489         u32 cp_variant_type = yaffs2_checkpt_obj_bit_get(cp, CHECKPOINT_VARIANT_BITS);
 490
 491         if (obj->variant_type != cp_variant_type) {
 492                 yaffs_trace(YAFFS_TRACE_ERROR,
 493                         "Checkpoint read object %d type %d chunk %d does not match existing object type %d",
 494                         cp->obj_id, cp_variant_type, cp->hdr_chunk,
 495                         obj->variant_type);
 496                 return 0;
 497         }
 498
 499         obj->obj_id = cp->obj_id;
 500
 501         if (cp->parent_id)
 502                 parent = yaffs_find_or_create_by_number(obj->my_dev,
 503                                                 cp->parent_id,
 504                                                 YAFFS_OBJECT_TYPE_DIRECTORY);
 505         else
 506                 parent = NULL;
 507
 508         if (parent) {
 509                 if (parent->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
 510                         yaffs_trace(YAFFS_TRACE_ALWAYS,
 511                                 "Checkpoint read object %d parent %d type %d chunk %d Parent type, %d, not directory",
 512                                 cp->obj_id, cp->parent_id,
 513                                 cp_variant_type, cp->hdr_chunk,
 514                                 parent->variant_type);
 515                         return 0;
 516                 }
 517                 yaffs_add_obj_to_dir(parent, obj);
 518         }
 519
 520         obj->hdr_chunk = cp->hdr_chunk;
 521
 522         obj->variant_type = yaffs2_checkpt_obj_bit_get(cp, CHECKPOINT_VARIANT_BITS);
 523         obj->deleted = yaffs2_checkpt_obj_bit_get(cp, CHECKPOINT_DELETED_BITS);
 524         obj->soft_del = yaffs2_checkpt_obj_bit_get(cp, CHECKPOINT_SOFT_DEL_BITS);
 525         obj->unlinked = yaffs2_checkpt_obj_bit_get(cp, CHECKPOINT_UNLINKED_BITS);
 526         obj->fake = yaffs2_checkpt_obj_bit_get(cp, CHECKPOINT_FAKE_BITS);
 527         obj->rename_allowed = yaffs2_checkpt_obj_bit_get(cp, CHECKPOINT_RENAME_ALLOWED_BITS);
 528         obj->unlink_allowed = yaffs2_checkpt_obj_bit_get(cp, CHECKPOINT_UNLINK_ALLOWED_BITS);
 529         obj->serial = yaffs2_checkpt_obj_bit_get(cp, CHECKPOINT_SERIAL_BITS);
 530
 531         obj->n_data_chunks = cp->n_data_chunks;
 532
 533         if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE) {
 534                 obj->variant.file_variant.file_size = cp->size_or_equiv_obj;
 535                 obj->variant.file_variant.stored_size = cp->size_or_equiv_obj;
 536         } else if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
 537                 obj->variant.hardlink_variant.equiv_id = cp->size_or_equiv_obj;
 538         }
 539         if (obj->hdr_chunk > 0)
 540                 obj->lazy_loaded = 1;
 541         return 1;
 542 }
 543
 544 static void yaffs2_do_endian_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
 545 {
 546         int i;
 547         u32 *as_u32 = (u32 *)tn;
 548         int tnode_size_u32 = dev->tnode_size / sizeof(u32);
 549
 550         if (!dev->swap_endian)
 551                 return;
 552         /* Swap all the tnode data as u32s to fix endianisms. */
 553         for (i = 0; i<tnode_size_u32; i++)
 554                 as_u32[i] = swap_u32(as_u32[i]);
 555 }
 556
 557 struct yaffs_tnode *yaffs2_do_endian_tnode_copy(struct yaffs_dev *dev,
 558                                                struct yaffs_tnode *tn)
 559 {
 560         if (!dev->swap_endian)
 561                 return tn;
 562
 563         memcpy(dev->tn_swap_buffer, tn, dev->tnode_size);
 564         tn = dev->tn_swap_buffer;
 565
 566         yaffs2_do_endian_tnode(dev, tn);
 567
 568         return tn;
 569 }
 570
 571 static int yaffs2_checkpt_tnode_worker(struct yaffs_obj *in,
 572                                        struct yaffs_tnode *tn, u32 level,
 573                                        int chunk_offset)
 574 {
 575         int i;
 576         struct yaffs_dev *dev = in->my_dev;
 577         int ok = 1;
 578         u32 base_offset;
 579
 580         if (!tn)
 581                 return 1;
 582
 583         if (level > 0) {
 584                 for (i = 0; i < YAFFS_NTNODES_INTERNAL && ok; i++) {
 585                         if (!tn->internal[i])
 586                                 continue;
 587                         ok = yaffs2_checkpt_tnode_worker(in,
 588                                  tn->internal[i],
 589                                  level - 1,
 590                                  (chunk_offset <<
 591                                   YAFFS_TNODES_INTERNAL_BITS) + i);
 592                 }
 593                 return ok;
 594         }
 595
 596         /* Level 0 tnode */
 597         base_offset = chunk_offset << YAFFS_TNODES_LEVEL0_BITS;
 598         yaffs_do_endian_u32(dev, &base_offset);
 599
 600         ok = (yaffs2_checkpt_wr(dev, &base_offset, sizeof(base_offset)) ==
 601                         sizeof(base_offset));
 602         if (ok) {
 603                 /*
 604                  * NB Can't do an in-place endian swizzle since that would
 605                  * damage current tnode data.
 606                  * If a tnode endian conversion is required we do a copy.
 607                  */
 608                 tn = yaffs2_do_endian_tnode_copy(dev, tn);
 609                 ok = (yaffs2_checkpt_wr(dev, tn, dev->tnode_size) ==
 610                         (int)dev->tnode_size);
 611         }
 612         return ok;
 613 }
 614
 615 static int yaffs2_wr_checkpt_tnodes(struct yaffs_obj *obj)
 616 {
 617         u32 end_marker = ~0;
 618         int ok = 1;
 619
 620         if (obj->variant_type != YAFFS_OBJECT_TYPE_FILE)
 621                 return ok;
 622
 623         ok = yaffs2_checkpt_tnode_worker(obj,
 624                                          obj->variant.file_variant.top,
 625                                          obj->variant.file_variant.
 626                                          top_level, 0);
 627         if (ok)
 628                 ok = (yaffs2_checkpt_wr(obj->my_dev, &end_marker,
 629                                 sizeof(end_marker)) == sizeof(end_marker));
 630
 631         return ok ? 1 : 0;
 632 }
 633
 634 static int yaffs2_rd_checkpt_tnodes(struct yaffs_obj *obj)
 635 {
 636         u32 base_chunk;
 637         int ok = 1;
 638         struct yaffs_dev *dev = obj->my_dev;
 639         struct yaffs_file_var *file_stuct_ptr = &obj->variant.file_variant;
 640         struct yaffs_tnode *tn;
 641         int nread = 0;
 642
 643         ok = (yaffs2_checkpt_rd(dev, &base_chunk, sizeof(base_chunk)) ==
 644               sizeof(base_chunk));
 645
 646         yaffs_do_endian_u32(dev, &base_chunk);
 647
 648         while (ok && (~base_chunk)) {
 649                 nread++;
 650                 /* Read level 0 tnode */
 651
 652                 tn = yaffs_get_tnode(dev);
 653                 if (tn) {
 654                         ok = (yaffs2_checkpt_rd(dev, tn, dev->tnode_size) ==
 655                                 (int)dev->tnode_size);
 656                         yaffs2_do_endian_tnode(dev, tn);
 657                 }
 658                 else
 659                         ok = 0;
 660
 661                 if (tn && ok)
 662                         ok = yaffs_add_find_tnode_0(dev,
 663                                                     file_stuct_ptr,
 664                                                     base_chunk, tn) ? 1 : 0;
 665
 666                 if (ok) {
 667                         ok = (yaffs2_checkpt_rd
 668                               (dev, &base_chunk,
 669                                sizeof(base_chunk)) == sizeof(base_chunk));
 670                         yaffs_do_endian_u32(dev, &base_chunk);
 671                 }
 672
 673         }
 674
 675         yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 676                 "Checkpoint read tnodes %d records, last %d. ok %d",
 677                 nread, base_chunk, ok);
 678
 679         return ok ? 1 : 0;
 680 }
 681
 682
 683 static void yaffs2_do_endian_checkpt_obj(struct yaffs_dev *dev,
 684                                          struct yaffs_checkpt_obj *cp)
 685 {
 686         if (!dev->swap_endian)
 687                 return;
 688         cp->struct_type = swap_s32(cp->struct_type);
 689         cp->obj_id = swap_u32(cp->obj_id);
 690         cp->parent_id = swap_u32(cp->parent_id);
 691         cp->hdr_chunk = swap_s32(cp->hdr_chunk);
 692         cp->bit_field = swap_u32(cp->bit_field);
 693         cp->n_data_chunks = swap_s32(cp->n_data_chunks);
 694         cp->size_or_equiv_obj = swap_loff_t(cp->size_or_equiv_obj);
 695 }
 696
 697 static int yaffs2_wr_checkpt_objs(struct yaffs_dev *dev)
 698 {
 699         struct yaffs_obj *obj;
 700         struct yaffs_checkpt_obj cp;
 701         int i;
 702         int ok = 1;
 703         struct list_head *lh;
 704         u32 cp_variant_type;
 705
 706         /* Iterate through the objects in each hash entry,
 707          * dumping them to the checkpointing stream.
 708          */
 709
 710         for (i = 0; ok && i < YAFFS_NOBJECT_BUCKETS; i++) {
 711                 list_for_each(lh, &dev->obj_bucket[i].list) {
 712                         obj = list_entry(lh, struct yaffs_obj, hash_link);
 713                         if (!obj->defered_free) {
 714                                 yaffs2_obj_checkpt_obj(&cp, obj);
 715                                 cp.struct_type = sizeof(cp);
 716                                 cp_variant_type = yaffs2_checkpt_obj_bit_get(
 717                                                 &cp, CHECKPOINT_VARIANT_BITS);
 718                                 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 719                                         "Checkpoint write object %d parent %d type %d chunk %d obj addr %p",
 720                                         cp.obj_id, cp.parent_id,
 721                                         cp_variant_type, cp.hdr_chunk, obj);
 722
 723                                 yaffs2_do_endian_checkpt_obj (dev, &cp);
 724                                 ok = (yaffs2_checkpt_wr(dev, &cp,
 725                                                 sizeof(cp)) == sizeof(cp));
 726
 727                                 if (ok &&
 728                                         obj->variant_type ==
 729                                         YAFFS_OBJECT_TYPE_FILE)
 730                                         ok = yaffs2_wr_checkpt_tnodes(obj);
 731                         }
 732                 }
 733         }
 734
 735         /* Dump end of list */
 736         memset(&cp, 0xff, sizeof(struct yaffs_checkpt_obj));
 737         cp.struct_type = sizeof(cp);
 738         yaffs2_do_endian_checkpt_obj (dev, &cp);
 739
 740         if (ok)
 741                 ok = (yaffs2_checkpt_wr(dev, &cp, sizeof(cp)) == sizeof(cp));
 742
 743         return ok ? 1 : 0;
 744 }
 745
 746 static int yaffs2_rd_checkpt_objs(struct yaffs_dev *dev)
 747 {
 748         struct yaffs_obj *obj;
 749         struct yaffs_checkpt_obj cp;
 750         int ok = 1;
 751         int done = 0;
 752         u32 cp_variant_type;
 753         LIST_HEAD(hard_list);
 754
 755
 756         while (ok && !done) {
 757                 ok = (yaffs2_checkpt_rd(dev, &cp, sizeof(cp)) == sizeof(cp));
 758                 yaffs2_do_endian_checkpt_obj (dev, &cp);
 759
 760                 if (cp.struct_type != sizeof(cp)) {
 761                         yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 762                                 "struct size %d instead of %d ok %d",
 763                                 cp.struct_type, (int)sizeof(cp), ok);
 764                         ok = 0;
 765                 }
 766
 767                 cp_variant_type = yaffs2_checkpt_obj_bit_get(
 768                                                 &cp, CHECKPOINT_VARIANT_BITS);
 769                 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 770                         "Checkpoint read object %d parent %d type %d chunk %d ",
 771                         cp.obj_id, cp.parent_id, cp_variant_type,
 772                         cp.hdr_chunk);
 773
 774                 if (ok && cp.obj_id == (u32)(~0)) {
 775                         done = 1;
 776                 } else if (ok) {
 777                         obj =
 778                             yaffs_find_or_create_by_number(dev, cp.obj_id,
 779                                                            cp_variant_type);
 780                         if (obj) {
 781                                 ok = yaffs2_checkpt_obj_to_obj(obj, &cp);
 782                                 if (!ok)
 783                                         break;
 784                                 if (obj->variant_type ==
 785                                         YAFFS_OBJECT_TYPE_FILE) {
 786                                         ok = yaffs2_rd_checkpt_tnodes(obj);
 787                                 } else if (obj->variant_type ==
 788                                         YAFFS_OBJECT_TYPE_HARDLINK) {
 789                                         list_add(&obj->hard_links, &hard_list);
 790                                 }
 791                         } else {
 792                                 ok = 0;
 793                         }
 794                 }
 795         }
 796
 797         if (ok)
 798                 yaffs_link_fixup(dev, &hard_list);
 799
 800         return ok ? 1 : 0;
 801 }
 802
 803 static int yaffs2_wr_checkpt_sum(struct yaffs_dev *dev)
 804 {
 805         u32 checkpt_sum;
 806         int ok;
 807
 808         yaffs2_get_checkpt_sum(dev, &checkpt_sum);
 809
 810         yaffs_do_endian_u32(dev, &checkpt_sum);
 811
 812         ok = (yaffs2_checkpt_wr(dev, &checkpt_sum, sizeof(checkpt_sum)) ==
 813                 sizeof(checkpt_sum));
 814
 815         if (!ok)
 816                 return 0;
 817
 818         return 1;
 819 }
 820
 821 static int yaffs2_rd_checkpt_sum(struct yaffs_dev *dev)
 822 {
 823         u32 checkpt_sum0;
 824         u32 checkpt_sum1;
 825         int ok;
 826
 827         yaffs2_get_checkpt_sum(dev, &checkpt_sum0);
 828
 829         ok = (yaffs2_checkpt_rd(dev, &checkpt_sum1, sizeof(checkpt_sum1)) ==
 830                 sizeof(checkpt_sum1));
 831
 832         if (!ok)
 833                 return 0;
 834         yaffs_do_endian_u32(dev, &checkpt_sum1);
 835
 836         if (checkpt_sum0 != checkpt_sum1)
 837                 return 0;
 838
 839         return 1;
 840 }
 841
 842 static int yaffs2_wr_checkpt_data(struct yaffs_dev *dev)
 843 {
 844         int ok = 1;
 845
 846         if (!yaffs2_checkpt_required(dev)) {
 847                 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 848                         "skipping checkpoint write");
 849                 ok = 0;
 850         }
 851
 852         if (ok)
 853                 ok = yaffs2_checkpt_open(dev, 1);
 854
 855         if (ok) {
 856                 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 857                         "write checkpoint validity");
 858                 ok = yaffs2_wr_checkpt_validity_marker(dev, 1);
 859         }
 860         if (ok) {
 861                 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 862                         "write checkpoint device");
 863                 ok = yaffs2_wr_checkpt_dev(dev);
 864         }
 865         if (ok) {
 866                 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 867                         "write checkpoint objects");
 868                 ok = yaffs2_wr_checkpt_objs(dev);
 869         }
 870         if (ok) {
 871                 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 872                         "write checkpoint validity");
 873                 ok = yaffs2_wr_checkpt_validity_marker(dev, 0);
 874         }
 875
 876         if (ok)
 877                 ok = yaffs2_wr_checkpt_sum(dev);
 878
 879         if (!yaffs_checkpt_close(dev))
 880                 ok = 0;
 881
 882         if (ok)
 883                 dev->is_checkpointed = 1;
 884         else
 885                 dev->is_checkpointed = 0;
 886
 887         return dev->is_checkpointed;
 888 }
 889
 890 static int yaffs2_rd_checkpt_data(struct yaffs_dev *dev)
 891 {
 892         int ok = 1;
 893
 894         if (!dev->param.is_yaffs2)
 895                 ok = 0;
 896
 897         if (ok && dev->param.skip_checkpt_rd) {
 898                 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 899                         "skipping checkpoint read");
 900                 ok = 0;
 901         }
 902
 903         if (ok)
 904                 ok = yaffs2_checkpt_open(dev, 0); /* open for read */
 905
 906         if (ok) {
 907                 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 908                         "read checkpoint validity");
 909                 ok = yaffs2_rd_checkpt_validity_marker(dev, 1);
 910         }
 911         if (ok) {
 912                 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 913                         "read checkpoint device");
 914                 ok = yaffs2_rd_checkpt_dev(dev);
 915         }
 916         if (ok) {
 917                 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 918                         "read checkpoint objects");
 919                 ok = yaffs2_rd_checkpt_objs(dev);
 920         }
 921         if (ok) {
 922                 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 923                         "read checkpoint validity");
 924                 ok = yaffs2_rd_checkpt_validity_marker(dev, 0);
 925         }
 926
 927         if (ok) {
 928                 ok = yaffs2_rd_checkpt_sum(dev);
 929                 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 930                         "read checkpoint checksum %d", ok);
 931         }
 932
 933         if (!yaffs_checkpt_close(dev))
 934                 ok = 0;
 935
 936         if (ok)
 937                 dev->is_checkpointed = 1;
 938         else
 939                 dev->is_checkpointed = 0;
 940
 941         return ok ? 1 : 0;
 942 }
 943
 944 void yaffs2_checkpt_invalidate(struct yaffs_dev *dev)
 945 {
 946         if (dev->is_checkpointed || dev->blocks_in_checkpt > 0) {
 947                 dev->is_checkpointed = 0;
 948                 yaffs2_checkpt_invalidate_stream(dev);
 949         }
 950         if (dev->param.sb_dirty_fn)
 951                 dev->param.sb_dirty_fn(dev);
 952 }
 953
 954 int yaffs_checkpoint_save(struct yaffs_dev *dev)
 955 {
 956         yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 957                 "save entry: is_checkpointed %d",
 958                 dev->is_checkpointed);
 959
 960         yaffs_verify_objects(dev);
 961         yaffs_verify_blocks(dev);
 962         yaffs_verify_free_chunks(dev);
 963
 964         if (!dev->is_checkpointed) {
 965                 yaffs2_checkpt_invalidate(dev);
 966                 yaffs2_wr_checkpt_data(dev);
 967         }
 968
 969         yaffs_trace(YAFFS_TRACE_CHECKPOINT | YAFFS_TRACE_MOUNT,
 970                 "save exit: is_checkpointed %d",
 971                 dev->is_checkpointed);
 972
 973         return dev->is_checkpointed;
 974 }
 975
 976 int yaffs2_checkpt_restore(struct yaffs_dev *dev)
 977 {
 978         int retval;
 979
 980         yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 981                 "restore entry: is_checkpointed %d",
 982                 dev->is_checkpointed);
 983
 984         retval = yaffs2_rd_checkpt_data(dev);
 985
 986         if (dev->is_checkpointed) {
 987                 yaffs_verify_objects(dev);
 988                 yaffs_verify_blocks(dev);
 989                 yaffs_verify_free_chunks(dev);
 990         }
 991
 992         yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 993                 "restore exit: is_checkpointed %d",
 994                 dev->is_checkpointed);
 995
 996         return retval;
 997 }
 998
 999 /* End of checkpointing */
1000
1001 /* Hole handling logic for truncate past end of file */
1002
1003 int yaffs2_handle_hole(struct yaffs_obj *obj, loff_t new_size)
1004 {
1005         /* if new_size > old_file_size.
1006          * We're going to be writing a hole.
1007          * If the hole is small then write zeros otherwise write a start
1008          * of hole marker.
1009          */
1010         loff_t old_file_size;
1011         loff_t increase;
1012         int small_hole;
1013         int result = YAFFS_OK;
1014         struct yaffs_dev *dev = NULL;
1015         u8 *local_buffer = NULL;
1016         int small_increase_ok = 0;
1017
1018         if (!obj)
1019                 return YAFFS_FAIL;
1020
1021         if (obj->variant_type != YAFFS_OBJECT_TYPE_FILE)
1022                 return YAFFS_FAIL;
1023
1024         dev = obj->my_dev;
1025
1026         /* Bail out if not yaffs2 mode */
1027         if (!dev->param.is_yaffs2)
1028                 return YAFFS_OK;
1029
1030         old_file_size = obj->variant.file_variant.file_size;
1031
1032         if (new_size <= old_file_size)
1033                 return YAFFS_OK;
1034
1035         increase = new_size - old_file_size;
1036
1037         if (increase < YAFFS_SMALL_HOLE_THRESHOLD * dev->data_bytes_per_chunk &&
1038             yaffs_check_alloc_available(dev, YAFFS_SMALL_HOLE_THRESHOLD + 1))
1039                 small_hole = 1;
1040         else
1041                 small_hole = 0;
1042
1043         if (small_hole)
1044                 local_buffer = yaffs_get_temp_buffer(dev);
1045
1046         if (local_buffer) {
1047                 /* fill hole with zero bytes */
1048                 loff_t pos = old_file_size;
1049                 int this_write;
1050                 int written;
1051                 memset(local_buffer, 0, dev->data_bytes_per_chunk);
1052                 small_increase_ok = 1;
1053
1054                 while (increase > 0 && small_increase_ok) {
1055                         this_write = increase;
1056                         if (this_write > (int)dev->data_bytes_per_chunk)
1057                                 this_write = dev->data_bytes_per_chunk;
1058                         written =
1059                             yaffs_do_file_wr(obj, local_buffer, pos, this_write,
1060                                              0);
1061                         if (written == this_write) {
1062                                 pos += this_write;
1063                                 increase -= this_write;
1064                         } else {
1065                                 small_increase_ok = 0;
1066                         }
1067                 }
1068
1069                 yaffs_release_temp_buffer(dev, local_buffer);
1070
1071                 /* If out of space then reverse any chunks we've added */
1072                 if (!small_increase_ok)
1073                         yaffs_resize_file_down(obj, old_file_size);
1074         }
1075
1076         if (!small_increase_ok &&
1077             obj->parent &&
1078             obj->parent->obj_id != YAFFS_OBJECTID_UNLINKED &&
1079             obj->parent->obj_id != YAFFS_OBJECTID_DELETED) {
1080                 /* Write a hole start header with the old file size */
1081                 yaffs_update_oh(obj, NULL, 0, 1, 0, NULL);
1082         }
1083
1084         return result;
1085 }
1086
1087 /* Yaffs2 scanning */
1088
1089 struct yaffs_block_index {
1090         int seq;
1091         int block;
1092 };
1093
1094 static int yaffs2_ybicmp(const void *a, const void *b)
1095 {
1096         int aseq = ((struct yaffs_block_index *)a)->seq;
1097         int bseq = ((struct yaffs_block_index *)b)->seq;
1098         int ablock = ((struct yaffs_block_index *)a)->block;
1099         int bblock = ((struct yaffs_block_index *)b)->block;
1100
1101         if (aseq == bseq)
1102                 return ablock - bblock;
1103
1104         return aseq - bseq;
1105 }
1106
1107 static inline int yaffs2_scan_chunk(struct yaffs_dev *dev,
1108                 struct yaffs_block_info *bi,
1109                 int blk, int chunk_in_block,
1110                 int *found_chunks,
1111                 u8 *chunk_data,
1112                 struct list_head *hard_list,
1113                 int summary_available)
1114 {
1115         struct yaffs_obj_hdr *oh;
1116         struct yaffs_obj *in;
1117         struct yaffs_obj *parent;
1118         int equiv_id;
1119         loff_t file_size;
1120         int is_shrink;
1121         int is_unlinked;
1122         struct yaffs_ext_tags tags;
1123         int result;
1124         int alloc_failed = 0;
1125         int chunk = blk * dev->param.chunks_per_block + chunk_in_block;
1126         struct yaffs_file_var *file_var;
1127         struct yaffs_hardlink_var *hl_var;
1128         struct yaffs_symlink_var *sl_var;
1129
1130         if (summary_available) {
1131                 result = yaffs_summary_fetch(dev, &tags, chunk_in_block);
1132                 tags.seq_number = bi->seq_number;
1133         }
1134
1135         if (!summary_available || tags.obj_id == 0) {
1136                 result = yaffs_rd_chunk_tags_nand(dev, chunk, NULL, &tags);
1137                 dev->tags_used++;
1138         } else {
1139                 dev->summary_used++;
1140         }
1141
1142         if (result == YAFFS_FAIL)
1143                 yaffs_trace(YAFFS_TRACE_SCAN,
1144                                 "Could not get tags for chunk %d\n", chunk);
1145         /* Let's have a good look at this chunk... */
1146
1147         if (!tags.chunk_used) {
1148                 /* An unassigned chunk in the block.
1149                  * If there are used chunks after this one, then
1150                  * it is a chunk that was skipped due to failing
1151                  * the erased check. Just skip it so that it can
1152                  * be deleted.
1153                  * But, more typically, We get here when this is
1154                  * an unallocated chunk and his means that
1155                  * either the block is empty or this is the one
1156                  * being allocated from
1157                  */
1158
1159                 if (*found_chunks) {
1160                         /* This is a chunk that was skipped due
1161                          * to failing the erased check */
1162                 } else if (chunk_in_block == 0) {
1163                         /* We're looking at the first chunk in
1164                          * the block so the block is unused */
1165                         bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
1166                         dev->n_erased_blocks++;
1167                 } else {
1168                         if (bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCAN ||
1169                             bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING) {
1170                                 if (dev->seq_number == bi->seq_number) {
1171                                         /* Allocating from this block*/
1172                                         yaffs_trace(YAFFS_TRACE_SCAN,
1173                                             " Allocating from %d %d",
1174                                             blk, chunk_in_block);
1175
1176                                         bi->block_state =
1177                                                 YAFFS_BLOCK_STATE_ALLOCATING;
1178                                         dev->alloc_block = blk;
1179                                         dev->alloc_page = chunk_in_block;
1180                                         dev->alloc_block_finder = blk;
1181                                 } else {
1182                                         /* This is a partially written block
1183                                          * that is not the current
1184                                          * allocation block.
1185                                          */
1186                                         yaffs_trace(YAFFS_TRACE_SCAN,
1187                                                 "Partially written block %d detected. gc will fix this.",
1188                                                 blk);
1189                                 }
1190                         }
1191                 }
1192
1193                 dev->n_free_chunks++;
1194
1195         } else if (tags.ecc_result ==
1196                 YAFFS_ECC_RESULT_UNFIXED) {
1197                 yaffs_trace(YAFFS_TRACE_SCAN,
1198                         " Unfixed ECC in chunk(%d:%d), chunk ignored",
1199                         blk, chunk_in_block);
1200                         dev->n_free_chunks++;
1201         } else if (tags.obj_id > YAFFS_MAX_OBJECT_ID ||
1202                    tags.chunk_id > YAFFS_MAX_CHUNK_ID ||
1203                    tags.obj_id == YAFFS_OBJECTID_SUMMARY ||
1204                    (tags.chunk_id > 0 &&
1205                      tags.n_bytes > dev->data_bytes_per_chunk) ||
1206                    tags.seq_number != bi->seq_number) {
1207                 yaffs_trace(YAFFS_TRACE_SCAN,
1208                         "Chunk (%d:%d) with bad tags:obj = %d, chunk_id = %d, n_bytes = %d, ignored",
1209                         blk, chunk_in_block, tags.obj_id,
1210                         tags.chunk_id, tags.n_bytes);
1211                 dev->n_free_chunks++;
1212         } else if (tags.chunk_id > 0) {
1213                 /* chunk_id > 0 so it is a data chunk... */
1214                 loff_t endpos;
1215                 loff_t chunk_base = (tags.chunk_id - 1) *
1216                                         dev->data_bytes_per_chunk;
1217
1218                 *found_chunks = 1;
1219
1220                 yaffs_set_chunk_bit(dev, blk, chunk_in_block);
1221                 bi->pages_in_use++;
1222
1223                 in = yaffs_find_or_create_by_number(dev,
1224                                         tags.obj_id,
1225                                         YAFFS_OBJECT_TYPE_FILE);
1226                 if (!in)
1227                         /* Out of memory */
1228                         alloc_failed = 1;
1229
1230                 if (in &&
1231                     in->variant_type == YAFFS_OBJECT_TYPE_FILE &&
1232                     chunk_base < in->variant.file_variant.shrink_size) {
1233                         /* This has not been invalidated by
1234                          * a resize */
1235                         if (!yaffs_put_chunk_in_file(in, tags.chunk_id,
1236                                                                 chunk, -1))
1237                                 alloc_failed = 1;
1238
1239                         /* File size is calculated by looking at
1240                          * the data chunks if we have not
1241                          * seen an object header yet.
1242                          * Stop this practice once we find an
1243                          * object header.
1244                          */
1245                         endpos = chunk_base + tags.n_bytes;
1246
1247                         if (!in->valid &&
1248                             in->variant.file_variant.stored_size < endpos) {
1249                                 in->variant.file_variant.
1250                                     stored_size = endpos;
1251                                 in->variant.file_variant.
1252                                     file_size = endpos;
1253                         }
1254                 } else if (in) {
1255                         /* This chunk has been invalidated by a
1256                          * resize, or a past file deletion
1257                          * so delete the chunk*/
1258                         yaffs_chunk_del(dev, chunk, 1, __LINE__);
1259                 }
1260         } else {
1261                 /* chunk_id == 0, so it is an ObjectHeader.
1262                  * Thus, we read in the object header and make
1263                  * the object
1264                  */
1265                 *found_chunks = 1;
1266
1267                 yaffs_set_chunk_bit(dev, blk, chunk_in_block);
1268                 bi->pages_in_use++;
1269
1270                 oh = NULL;
1271                 in = NULL;
1272
1273                 if (tags.extra_available) {
1274                         in = yaffs_find_or_create_by_number(dev,
1275                                         tags.obj_id,
1276                                         tags.extra_obj_type);
1277                         if (!in)
1278                                 alloc_failed = 1;
1279                 }
1280
1281                 if (!in ||
1282                     (!in->valid && dev->param.disable_lazy_load) ||
1283                     tags.extra_shadows ||
1284                     (!in->valid && (tags.obj_id == YAFFS_OBJECTID_ROOT ||
1285                                  tags.obj_id == YAFFS_OBJECTID_LOSTNFOUND))) {
1286
1287                         /* If we don't have  valid info then we
1288                          * need to read the chunk
1289                          * TODO In future we can probably defer
1290                          * reading the chunk and living with
1291                          * invalid data until needed.
1292                          */
1293
1294                         result = yaffs_rd_chunk_tags_nand(dev,
1295                                                   chunk,
1296                                                   chunk_data,
1297                                                   NULL);
1298
1299                         oh = (struct yaffs_obj_hdr *)chunk_data;
1300
1301                         yaffs_do_endian_oh(dev, oh);
1302
1303                         if (dev->param.inband_tags) {
1304                                 /* Fix up the header if they got
1305                                  * corrupted by inband tags */
1306                                 oh->shadows_obj =
1307                                     oh->inband_shadowed_obj_id;
1308                                 oh->is_shrink =
1309                                     oh->inband_is_shrink;
1310                         }
1311
1312                         if (!in) {
1313                                 in = yaffs_find_or_create_by_number(dev,
1314                                                         tags.obj_id, oh->type);
1315                                 if (!in)
1316                                         alloc_failed = 1;
1317                         }
1318                 }
1319
1320                 if (!in) {
1321                         /* TODO Hoosterman we have a problem! */
1322                         yaffs_trace(YAFFS_TRACE_ERROR,
1323                                 "yaffs tragedy: Could not make object for object  %d at chunk %d during scan",
1324                                 tags.obj_id, chunk);
1325                         return YAFFS_FAIL;
1326                 }
1327
1328                 if (in->valid) {
1329                         /* We have already filled this one.
1330                          * We have a duplicate that will be
1331                          * discarded, but we first have to suck
1332                          * out resize info if it is a file.
1333                          */
1334                         if ((in->variant_type == YAFFS_OBJECT_TYPE_FILE) &&
1335                                 ((oh && oh->type == YAFFS_OBJECT_TYPE_FILE) ||
1336                                  (tags.extra_available &&
1337                                   tags.extra_obj_type == YAFFS_OBJECT_TYPE_FILE)
1338                                 )) {
1339                                 loff_t this_size = (oh) ?
1340                                         yaffs_oh_to_size(dev, oh, 0) :
1341                                         tags.extra_file_size;
1342                                 u32 parent_obj_id = (oh) ?
1343                                         (u32)oh->parent_obj_id :
1344                                         tags.extra_parent_id;
1345
1346                                 is_shrink = (oh) ?
1347                                         oh->is_shrink :
1348                                         tags.extra_is_shrink;
1349
1350                                 /* If it is deleted (unlinked
1351                                  * at start also means deleted)
1352                                  * we treat the file size as
1353                                  * being zeroed at this point.
1354                                  */
1355                                 if (parent_obj_id == YAFFS_OBJECTID_DELETED ||
1356                                     parent_obj_id == YAFFS_OBJECTID_UNLINKED) {
1357                                         this_size = 0;
1358                                         is_shrink = 1;
1359                                 }
1360
1361                                 if (is_shrink &&
1362                                     in->variant.file_variant.shrink_size >
1363                                     this_size)
1364                                         in->variant.file_variant.shrink_size =
1365                                         this_size;
1366
1367                                 if (is_shrink)
1368                                         bi->has_shrink_hdr = 1;
1369                         }
1370                         /* Use existing - destroy this one. */
1371                         yaffs_chunk_del(dev, chunk, 1, __LINE__);
1372                 }
1373
1374                 if (!in->valid && in->variant_type !=
1375                     (oh ? oh->type : tags.extra_obj_type)) {
1376                         yaffs_trace(YAFFS_TRACE_ERROR,
1377                                 "yaffs tragedy: Bad type, %d != %d, for object %d at chunk %d during scan",
1378                                 oh ? oh->type : tags.extra_obj_type,
1379                                 in->variant_type, tags.obj_id,
1380                                 chunk);
1381                         in = yaffs_retype_obj(in, oh ? oh->type : tags.extra_obj_type);
1382                 }
1383
1384                 if (!in->valid &&
1385                     (tags.obj_id == YAFFS_OBJECTID_ROOT ||
1386                      tags.obj_id == YAFFS_OBJECTID_LOSTNFOUND)) {
1387                         /* We only load some info, don't fiddle
1388                          * with directory structure */
1389                         in->valid = 1;
1390
1391                         if (oh) {
1392                                 in->yst_mode = oh->yst_mode;
1393                                 yaffs_load_attribs(in, oh);
1394                                 in->lazy_loaded = 0;
1395                         } else {
1396                                 in->lazy_loaded = 1;
1397                         }
1398                         in->hdr_chunk = chunk;
1399
1400                 } else if (!in->valid) {
1401                         /* we need to load this info */
1402                         in->valid = 1;
1403                         in->hdr_chunk = chunk;
1404                         if (oh) {
1405                                 in->variant_type = oh->type;
1406                                 in->yst_mode = oh->yst_mode;
1407                                 yaffs_load_attribs(in, oh);
1408
1409                                 if (oh->shadows_obj > 0)
1410                                         yaffs_handle_shadowed_obj(dev,
1411                                              oh->shadows_obj, 1);
1412
1413                                 yaffs_set_obj_name_from_oh(in, oh);
1414                                 parent = yaffs_find_or_create_by_number(dev,
1415                                                 oh->parent_obj_id,
1416                                                 YAFFS_OBJECT_TYPE_DIRECTORY);
1417                                 file_size = yaffs_oh_to_size(dev, oh, 0);
1418                                 is_shrink = oh->is_shrink;
1419                                 equiv_id = oh->equiv_id;
1420                         } else {
1421                                 in->variant_type = tags.extra_obj_type;
1422                                 parent = yaffs_find_or_create_by_number(dev,
1423                                                 tags.extra_parent_id,
1424                                                 YAFFS_OBJECT_TYPE_DIRECTORY);
1425                                 file_size = tags.extra_file_size;
1426                                 is_shrink = tags.extra_is_shrink;
1427                                 equiv_id = tags.extra_equiv_id;
1428                                 in->lazy_loaded = 1;
1429                         }
1430                         in->dirty = 0;
1431
1432                         if (!parent)
1433                                 alloc_failed = 1;
1434
1435                         /* directory stuff...
1436                          * hook up to parent
1437                          */
1438
1439                         if (parent &&
1440                             parent->variant_type == YAFFS_OBJECT_TYPE_UNKNOWN) {
1441                                 /* Set up as a directory */
1442                                 parent->variant_type =
1443                                         YAFFS_OBJECT_TYPE_DIRECTORY;
1444                                 INIT_LIST_HEAD(&parent->
1445                                                 variant.dir_variant.children);
1446                         } else if (!parent ||
1447                                    parent->variant_type !=
1448                                         YAFFS_OBJECT_TYPE_DIRECTORY) {
1449                                 /* Hoosterman, another problem....
1450                                  * Trying to use a non-directory as a directory
1451                                  */
1452
1453                                 yaffs_trace(YAFFS_TRACE_ERROR,
1454                                         "yaffs tragedy: attempting to use non-directory as a directory in scan. Put in lost+found."
1455                                         );
1456                                 parent = dev->lost_n_found;
1457                         }
1458                         yaffs_add_obj_to_dir(parent, in);
1459
1460                         is_unlinked = (parent == dev->del_dir) ||
1461                                         (parent == dev->unlinked_dir);
1462
1463                         if (is_shrink)
1464                                 /* Mark the block */
1465                                 bi->has_shrink_hdr = 1;
1466
1467                         /* Note re hardlinks.
1468                          * Since we might scan a hardlink before its equivalent
1469                          * object is scanned we put them all in a list.
1470                          * After scanning is complete, we should have all the
1471                          * objects, so we run through this list and fix up all
1472                          * the chains.
1473                          */
1474
1475                         switch (in->variant_type) {
1476                         case YAFFS_OBJECT_TYPE_UNKNOWN:
1477                                 /* Todo got a problem */
1478                                 break;
1479                         case YAFFS_OBJECT_TYPE_FILE:
1480                                 file_var = &in->variant.file_variant;
1481                                 if (file_var->stored_size < file_size) {
1482                                         /* This covers the case where the file
1483                                          * size is greater than the data held.
1484                                          * This will happen if the file is
1485                                          * resized to be larger than its
1486                                          * current data extents.
1487                                          */
1488                                         file_var->file_size = file_size;
1489                                         file_var->stored_size = file_size;
1490                                 }
1491
1492                                 if (file_var->shrink_size > file_size)
1493                                         file_var->shrink_size = file_size;
1494
1495                                 break;
1496                         case YAFFS_OBJECT_TYPE_HARDLINK:
1497                                 hl_var = &in->variant.hardlink_variant;
1498                                 if (!is_unlinked) {
1499                                         hl_var->equiv_id = equiv_id;
1500                                         list_add(&in->hard_links, hard_list);
1501                                 }
1502                                 break;
1503                         case YAFFS_OBJECT_TYPE_DIRECTORY:
1504                                 /* Do nothing */
1505                                 break;
1506                         case YAFFS_OBJECT_TYPE_SPECIAL:
1507                                 /* Do nothing */
1508                                 break;
1509                         case YAFFS_OBJECT_TYPE_SYMLINK:
1510                                 sl_var = &in->variant.symlink_variant;
1511                                 if (oh) {
1512                                         sl_var->alias =
1513                                             yaffs_clone_str(oh->alias);
1514                                         if (!sl_var->alias)
1515                                                 alloc_failed = 1;
1516                                 }
1517                                 break;
1518                         }
1519                 }
1520         }
1521         return alloc_failed ? YAFFS_FAIL : YAFFS_OK;
1522 }
1523
1524 int yaffs2_scan_backwards(struct yaffs_dev *dev)
1525 {
1526         u32 blk;
1527         int block_iter;
1528         int start_iter;
1529         int end_iter;
1530         int n_to_scan = 0;
1531         enum yaffs_block_state state;
1532         int c;
1533         LIST_HEAD(hard_list);
1534         struct yaffs_block_info *bi;
1535         u32 seq_number;
1536         int n_blocks = dev->internal_end_block - dev->internal_start_block + 1;
1537         u8 *chunk_data;
1538         int found_chunks;
1539         int alloc_failed = 0;
1540         struct yaffs_block_index *block_index = NULL;
1541         int alt_block_index = 0;
1542         int summary_available;
1543
1544         yaffs_trace(YAFFS_TRACE_SCAN,
1545                 "yaffs2_scan_backwards starts  intstartblk %d intendblk %d...",
1546                 dev->internal_start_block, dev->internal_end_block);
1547
1548         dev->seq_number = YAFFS_LOWEST_SEQUENCE_NUMBER;
1549
1550         block_index =
1551                 kmalloc(n_blocks * sizeof(struct yaffs_block_index), GFP_NOFS);
1552
1553         if (!block_index) {
1554                 block_index =
1555                     vmalloc(n_blocks * sizeof(struct yaffs_block_index));
1556                 alt_block_index = 1;
1557         }
1558
1559         if (!block_index) {
1560                 yaffs_trace(YAFFS_TRACE_SCAN,
1561                         "yaffs2_scan_backwards() could not allocate block index!"
1562                         );
1563                 return YAFFS_FAIL;
1564         }
1565
1566         dev->blocks_in_checkpt = 0;
1567
1568         chunk_data = yaffs_get_temp_buffer(dev);
1569
1570         /* Scan all the blocks to determine their state */
1571         bi = dev->block_info;
1572         for (blk = dev->internal_start_block; blk <= dev->internal_end_block;
1573              blk++) {
1574                 yaffs_clear_chunk_bits(dev, blk);
1575                 bi->pages_in_use = 0;
1576                 bi->soft_del_pages = 0;
1577
1578                 yaffs_query_init_block_state(dev, blk, &state, &seq_number);
1579
1580                 bi->block_state = state;
1581                 bi->seq_number = seq_number;
1582
1583                 if (bi->seq_number == YAFFS_SEQUENCE_CHECKPOINT_DATA)
1584                         bi->block_state = YAFFS_BLOCK_STATE_CHECKPOINT;
1585                 if (bi->seq_number == YAFFS_SEQUENCE_BAD_BLOCK)
1586                         bi->block_state = YAFFS_BLOCK_STATE_DEAD;
1587
1588                 yaffs_trace(YAFFS_TRACE_SCAN_DEBUG,
1589                         "Block scanning block %d state %d seq %d",
1590                         blk, bi->block_state, seq_number);
1591
1592                 if (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT) {
1593                         dev->blocks_in_checkpt++;
1594
1595                 } else if (bi->block_state == YAFFS_BLOCK_STATE_DEAD) {
1596                         yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
1597                                 "block %d is bad", blk);
1598                 } else if (bi->block_state == YAFFS_BLOCK_STATE_EMPTY) {
1599                         yaffs_trace(YAFFS_TRACE_SCAN_DEBUG, "Block empty ");
1600                         dev->n_erased_blocks++;
1601                         dev->n_free_chunks += dev->param.chunks_per_block;
1602                 } else if (bi->block_state ==
1603                                 YAFFS_BLOCK_STATE_NEEDS_SCAN) {
1604                         /* Determine the highest sequence number */
1605                         if (seq_number >= YAFFS_LOWEST_SEQUENCE_NUMBER &&
1606                             seq_number < YAFFS_HIGHEST_SEQUENCE_NUMBER) {
1607                                 block_index[n_to_scan].seq = seq_number;
1608                                 block_index[n_to_scan].block = blk;
1609                                 n_to_scan++;
1610                                 if (seq_number >= dev->seq_number)
1611                                         dev->seq_number = seq_number;
1612                         } else {
1613                                 /* TODO: Nasty sequence number! */
1614                                 yaffs_trace(YAFFS_TRACE_SCAN,
1615                                         "Block scanning block %d has bad sequence number %d",
1616                                         blk, seq_number);
1617                         }
1618                 }
1619                 bi++;
1620         }
1621
1622         yaffs_trace(YAFFS_TRACE_ALWAYS, "%d blocks to be sorted...", n_to_scan);
1623
1624         cond_resched();
1625
1626         /* Sort the blocks by sequence number */
1627         sort(block_index, n_to_scan, sizeof(struct yaffs_block_index),
1628                    yaffs2_ybicmp, NULL);
1629
1630         cond_resched();
1631
1632         yaffs_trace(YAFFS_TRACE_SCAN, "...done");
1633
1634         /* Now scan the blocks looking at the data. */
1635         start_iter = 0;
1636         end_iter = n_to_scan - 1;
1637         yaffs_trace(YAFFS_TRACE_SCAN_DEBUG, "%d blocks to scan", n_to_scan);
1638
1639         /* For each block.... backwards */
1640         for (block_iter = end_iter;
1641              !alloc_failed && block_iter >= start_iter;
1642              block_iter--) {
1643                 /* Cooperative multitasking! This loop can run for so
1644                    long that watchdog timers expire. */
1645                 cond_resched();
1646
1647                 /* get the block to scan in the correct order */
1648                 blk = block_index[block_iter].block;
1649                 bi = yaffs_get_block_info(dev, blk);
1650
1651                 summary_available = yaffs_summary_read(dev, dev->sum_tags, blk);
1652
1653                 /* For each chunk in each block that needs scanning.... */
1654                 found_chunks = 0;
1655                 if (summary_available)
1656                         c = dev->chunks_per_summary - 1;
1657                 else
1658                         c = dev->param.chunks_per_block - 1;
1659
1660                 for (/* c is already initialised */;
1661                      !alloc_failed && c >= 0 &&
1662                      (bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCAN ||
1663                       bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING);
1664                       c--) {
1665                         /* Scan backwards...
1666                          * Read the tags and decide what to do
1667                          */
1668                         if (yaffs2_scan_chunk(dev, bi, blk, c,
1669                                         &found_chunks, chunk_data,
1670                                         &hard_list, summary_available) ==
1671                                         YAFFS_FAIL)
1672                                 alloc_failed = 1;
1673                 }
1674
1675                 if (bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCAN) {
1676                         /* If we got this far while scanning, then the block
1677                          * is fully allocated. */
1678                         bi->block_state = YAFFS_BLOCK_STATE_FULL;
1679                 }
1680
1681                 /* Now let's see if it was dirty */
1682                 if (bi->pages_in_use == 0 &&
1683                     !bi->has_shrink_hdr &&
1684                     bi->block_state == YAFFS_BLOCK_STATE_FULL) {
1685                         yaffs_block_became_dirty(dev, blk);
1686                 }
1687         }
1688
1689         yaffs_skip_rest_of_block(dev);
1690
1691         if (alt_block_index)
1692                 vfree(block_index);
1693         else
1694                 kfree(block_index);
1695
1696         /* Ok, we've done all the scanning.
1697          * Fix up the hard link chains.
1698          * We have scanned all the objects, now it's time to add these
1699          * hardlinks.
1700          */
1701         yaffs_link_fixup(dev, &hard_list);
1702
1703         yaffs_release_temp_buffer(dev, chunk_data);
1704
1705         if (alloc_failed)
1706                 return YAFFS_FAIL;
1707
1708         yaffs_trace(YAFFS_TRACE_SCAN, "yaffs2_scan_backwards ends");
1709
1710         return YAFFS_OK;
1711 }