yaffs_checkptrw.c

   1 /*
   2  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
   3  *
   4  * Copyright (C) 2002-2011 Aleph One Ltd.
   5  *   for Toby Churchill Ltd and Brightstar Engineering
   6  *
   7  * Created by Charles Manning <charles@aleph1.co.uk>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #include "yaffs_checkptrw.h"
  15 #include "yaffs_getblockinfo.h"
  16 #include "yaffs_endian.h"
  17
  18 struct yaffs_checkpt_chunk_hdr {
  19         int version;
  20         int seq;
  21         u32 sum;
  22         u32 xor;
  23 } ;
  24
  25
  26 static int apply_chunk_offset(struct yaffs_dev *dev, int chunk)
  27 {
  28         return chunk - dev->chunk_offset;
  29 }
  30
  31 static int apply_block_offset(struct yaffs_dev *dev, int block)
  32 {
  33         return block - dev->block_offset;
  34 }
  35
  36
  37 static void yaffs2_do_endian_hdr(struct yaffs_dev *dev,
  38                                  struct yaffs_checkpt_chunk_hdr *hdr)
  39 {
  40         if (!dev->swap_endian)
  41                 return;
  42         hdr->version = swap_s32(hdr->version);
  43         hdr->seq     = swap_s32(hdr->seq);
  44         hdr->sum     = swap_u32(hdr->sum);
  45         hdr->xor     = swap_u32(hdr->xor);
  46 }
  47
  48 static void yaffs2_checkpt_init_chunk_hdr(struct yaffs_dev *dev)
  49 {
  50         struct yaffs_checkpt_chunk_hdr hdr;
  51
  52         hdr.version = YAFFS_CHECKPOINT_VERSION;
  53         hdr.seq = dev->checkpt_page_seq;
  54         hdr.sum = dev->checkpt_sum;
  55         hdr.xor = dev->checkpt_xor;
  56
  57         dev->checkpt_byte_offs = sizeof(hdr);
  58
  59         yaffs2_do_endian_hdr(dev, &hdr);
  60         memcpy(dev->checkpt_buffer, &hdr, sizeof(hdr));
  61 }
  62
  63 static int yaffs2_checkpt_check_chunk_hdr(struct yaffs_dev *dev)
  64 {
  65         struct yaffs_checkpt_chunk_hdr hdr;
  66
  67         memcpy(&hdr, dev->checkpt_buffer, sizeof(hdr));
  68         yaffs2_do_endian_hdr(dev, &hdr);
  69
  70         dev->checkpt_byte_offs = sizeof(hdr);
  71
  72         return hdr.version == YAFFS_CHECKPOINT_VERSION &&
  73                 hdr.seq == dev->checkpt_page_seq &&
  74                 hdr.sum == dev->checkpt_sum &&
  75                 hdr.xor == dev->checkpt_xor;
  76 }
  77
  78 static int yaffs2_checkpt_space_ok(struct yaffs_dev *dev)
  79 {
  80         int blocks_avail = dev->n_erased_blocks - dev->param.n_reserved_blocks;
  81
  82         yaffs_trace(YAFFS_TRACE_CHECKPOINT,
  83                 "checkpt blocks_avail = %d", blocks_avail);
  84
  85         return (blocks_avail <= 0) ? 0 : 1;
  86 }
  87
  88 static int yaffs_checkpt_erase(struct yaffs_dev *dev)
  89 {
  90         int i;
  91
  92         if (!dev->drv.drv_erase_fn)
  93                 return 0;
  94         yaffs_trace(YAFFS_TRACE_CHECKPOINT,
  95                 "checking blocks %d to %d",
  96                 dev->internal_start_block, dev->internal_end_block);
  97
  98         for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
  99                 struct yaffs_block_info *bi = yaffs_get_block_info(dev, i);
 100                 int offset_i = apply_block_offset(dev, i);
 101                 int result;
 102
 103                 if (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT) {
 104                         yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 105                         "erasing checkpt block %d", i);
 106
 107                         dev->n_erasures++;
 108
 109                         result = dev->drv.drv_erase_fn(dev, offset_i);
 110                         if(result) {
 111                                 bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
 112                                 dev->n_erased_blocks++;
 113                                 dev->n_free_chunks +=
 114                                     dev->param.chunks_per_block;
 115                         } else {
 116                                 dev->drv.drv_mark_bad_fn(dev, offset_i);
 117                                 bi->block_state = YAFFS_BLOCK_STATE_DEAD;
 118                         }
 119                 }
 120         }
 121
 122         dev->blocks_in_checkpt = 0;
 123
 124         return 1;
 125 }
 126
 127 static void yaffs2_checkpt_find_erased_block(struct yaffs_dev *dev)
 128 {
 129         int i;
 130         int blocks_avail = dev->n_erased_blocks - dev->param.n_reserved_blocks;
 131
 132         yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 133                 "allocating checkpt block: erased %d reserved %d avail %d next %d ",
 134                 dev->n_erased_blocks, dev->param.n_reserved_blocks,
 135                 blocks_avail, dev->checkpt_next_block);
 136
 137         if (dev->checkpt_next_block >= 0 &&
 138             dev->checkpt_next_block <= dev->internal_end_block &&
 139             blocks_avail > 0) {
 140
 141                 for (i = dev->checkpt_next_block; i <= dev->internal_end_block;
 142                      i++) {
 143                         struct yaffs_block_info *bi;
 144
 145                         bi = yaffs_get_block_info(dev, i);
 146                         if (bi->block_state == YAFFS_BLOCK_STATE_EMPTY) {
 147                                 dev->checkpt_next_block = i + 1;
 148                                 dev->checkpt_cur_block = i;
 149                                 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 150                                         "allocating checkpt block %d", i);
 151                                 return;
 152                         }
 153                 }
 154         }
 155         yaffs_trace(YAFFS_TRACE_CHECKPOINT, "out of checkpt blocks");
 156
 157         dev->checkpt_next_block = -1;
 158         dev->checkpt_cur_block = -1;
 159 }
 160
 161 static void yaffs2_checkpt_find_block(struct yaffs_dev *dev)
 162 {
 163         int i;
 164         struct yaffs_ext_tags tags;
 165
 166         yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 167                 "find next checkpt block: start:  blocks %d next %d",
 168                 dev->blocks_in_checkpt, dev->checkpt_next_block);
 169
 170         if (dev->blocks_in_checkpt < dev->checkpt_max_blocks)
 171                 for (i = dev->checkpt_next_block; i <= dev->internal_end_block;
 172                      i++) {
 173                         int chunk = i * dev->param.chunks_per_block;
 174                         enum yaffs_block_state state;
 175                         u32 seq;
 176
 177                         dev->tagger.read_chunk_tags_fn(dev,
 178                                         apply_chunk_offset(dev, chunk),
 179                                         NULL, &tags);
 180                         yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 181                                 "find next checkpt block: search: block %d state %d oid %d seq %d eccr %d",
 182                                 i, (int) state,
 183                                 tags.obj_id, tags.seq_number,
 184                                 tags.ecc_result);
 185
 186                         if (tags.seq_number != YAFFS_SEQUENCE_CHECKPOINT_DATA)
 187                                 continue;
 188
 189                         dev->tagger.query_block_fn(dev,
 190                                                 apply_block_offset(dev, i),
 191                                                 &state, &seq);
 192                         if (state == YAFFS_BLOCK_STATE_DEAD)
 193                                 continue;
 194
 195                         /* Right kind of block */
 196                         dev->checkpt_next_block = tags.obj_id;
 197                         dev->checkpt_cur_block = i;
 198                         dev->checkpt_block_list[dev->blocks_in_checkpt] = i;
 199                         dev->blocks_in_checkpt++;
 200                         yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 201                                 "found checkpt block %d", i);
 202                         return;
 203                 }
 204
 205         yaffs_trace(YAFFS_TRACE_CHECKPOINT, "found no more checkpt blocks");
 206
 207         dev->checkpt_next_block = -1;
 208         dev->checkpt_cur_block = -1;
 209 }
 210
 211 int yaffs2_checkpt_open(struct yaffs_dev *dev, int writing)
 212 {
 213         int i;
 214
 215         dev->checkpt_open_write = writing;
 216
 217         /* Got the functions we need? */
 218         if (!dev->tagger.write_chunk_tags_fn ||
 219             !dev->tagger.read_chunk_tags_fn ||
 220             !dev->drv.drv_erase_fn ||
 221             !dev->drv.drv_mark_bad_fn)
 222                 return 0;
 223
 224         if (writing && !yaffs2_checkpt_space_ok(dev))
 225                 return 0;
 226
 227         if (!dev->checkpt_buffer)
 228                 dev->checkpt_buffer =
 229                     kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
 230         if (!dev->checkpt_buffer)
 231                 return 0;
 232
 233         dev->checkpt_page_seq = 0;
 234         dev->checkpt_byte_count = 0;
 235         dev->checkpt_sum = 0;
 236         dev->checkpt_xor = 0;
 237         dev->checkpt_cur_block = -1;
 238         dev->checkpt_cur_chunk = -1;
 239         dev->checkpt_next_block = dev->internal_start_block;
 240
 241         if (writing) {
 242                 memset(dev->checkpt_buffer, 0, dev->data_bytes_per_chunk);
 243                 yaffs2_checkpt_init_chunk_hdr(dev);
 244                 return yaffs_checkpt_erase(dev);
 245         }
 246
 247         /* Opening for a read */
 248         /* Set to a value that will kick off a read */
 249         dev->checkpt_byte_offs = dev->data_bytes_per_chunk;
 250         /* A checkpoint block list of 1 checkpoint block per 16 block is
 251          * (hopefully) going to be way more than we need */
 252         dev->blocks_in_checkpt = 0;
 253         dev->checkpt_max_blocks =
 254             (dev->internal_end_block - dev->internal_start_block) / 16 + 2;
 255         if (!dev->checkpt_block_list)
 256                 dev->checkpt_block_list =
 257                       kmalloc(sizeof(int) * dev->checkpt_max_blocks, GFP_NOFS);
 258
 259         if (!dev->checkpt_block_list)
 260                 return 0;
 261
 262         for (i = 0; i < dev->checkpt_max_blocks; i++)
 263                 dev->checkpt_block_list[i] = -1;
 264
 265         return 1;
 266 }
 267
 268 int yaffs2_get_checkpt_sum(struct yaffs_dev *dev, u32 * sum)
 269 {
 270         u32 composite_sum;
 271
 272         composite_sum = (dev->checkpt_sum << 8) | (dev->checkpt_xor & 0xff);
 273         *sum = composite_sum;
 274         return 1;
 275 }
 276
 277 static int yaffs2_checkpt_flush_buffer(struct yaffs_dev *dev)
 278 {
 279         int chunk;
 280         int offset_chunk;
 281         struct yaffs_ext_tags tags;
 282
 283         if (dev->checkpt_cur_block < 0) {
 284                 yaffs2_checkpt_find_erased_block(dev);
 285                 dev->checkpt_cur_chunk = 0;
 286         }
 287
 288         if (dev->checkpt_cur_block < 0)
 289                 return 0;
 290
 291         tags.is_deleted = 0;
 292         tags.obj_id = dev->checkpt_next_block;  /* Hint to next place to look */
 293         tags.chunk_id = dev->checkpt_page_seq + 1;
 294         tags.seq_number = YAFFS_SEQUENCE_CHECKPOINT_DATA;
 295         tags.n_bytes = dev->data_bytes_per_chunk;
 296         if (dev->checkpt_cur_chunk == 0) {
 297                 /* First chunk we write for the block? Set block state to
 298                    checkpoint */
 299                 struct yaffs_block_info *bi =
 300                     yaffs_get_block_info(dev, dev->checkpt_cur_block);
 301                 bi->block_state = YAFFS_BLOCK_STATE_CHECKPOINT;
 302                 dev->blocks_in_checkpt++;
 303         }
 304
 305         chunk =
 306             dev->checkpt_cur_block * dev->param.chunks_per_block +
 307             dev->checkpt_cur_chunk;
 308
 309         yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 310                 "checkpoint wite buffer nand %d(%d:%d) objid %d chId %d",
 311                 chunk, dev->checkpt_cur_block, dev->checkpt_cur_chunk,
 312                 tags.obj_id, tags.chunk_id);
 313
 314         offset_chunk = apply_chunk_offset(dev, chunk);
 315
 316         dev->n_page_writes++;
 317
 318         dev->tagger.write_chunk_tags_fn(dev, offset_chunk,
 319                                        dev->checkpt_buffer, &tags);
 320         dev->checkpt_page_seq++;
 321         dev->checkpt_cur_chunk++;
 322         if (dev->checkpt_cur_chunk >= dev->param.chunks_per_block) {
 323                 dev->checkpt_cur_chunk = 0;
 324                 dev->checkpt_cur_block = -1;
 325         }
 326         memset(dev->checkpt_buffer, 0, dev->data_bytes_per_chunk);
 327
 328         yaffs2_checkpt_init_chunk_hdr(dev);
 329
 330
 331         return 1;
 332 }
 333
 334 int yaffs2_checkpt_wr(struct yaffs_dev *dev, const void *data, int n_bytes)
 335 {
 336         int i = 0;
 337         int ok = 1;
 338         u8 *data_bytes = (u8 *) data;
 339
 340         if (!dev->checkpt_buffer)
 341                 return 0;
 342
 343         if (!dev->checkpt_open_write)
 344                 return -1;
 345
 346         while (i < n_bytes && ok) {
 347                 dev->checkpt_buffer[dev->checkpt_byte_offs] = *data_bytes;
 348                 dev->checkpt_sum += *data_bytes;
 349                 dev->checkpt_xor ^= *data_bytes;
 350
 351                 dev->checkpt_byte_offs++;
 352                 i++;
 353                 data_bytes++;
 354                 dev->checkpt_byte_count++;
 355
 356                 if (dev->checkpt_byte_offs < 0 ||
 357                     dev->checkpt_byte_offs >= dev->data_bytes_per_chunk)
 358                         ok = yaffs2_checkpt_flush_buffer(dev);
 359         }
 360
 361         return i;
 362 }
 363
 364 int yaffs2_checkpt_rd(struct yaffs_dev *dev, void *data, int n_bytes)
 365 {
 366         int i = 0;
 367         struct yaffs_ext_tags tags;
 368         int chunk;
 369         int offset_chunk;
 370         u8 *data_bytes = (u8 *) data;
 371
 372         if (!dev->checkpt_buffer)
 373                 return 0;
 374
 375         if (dev->checkpt_open_write)
 376                 return -1;
 377
 378         while (i < n_bytes) {
 379
 380                 if (dev->checkpt_byte_offs < 0 ||
 381                     dev->checkpt_byte_offs >= dev->data_bytes_per_chunk) {
 382
 383                         if (dev->checkpt_cur_block < 0) {
 384                                 yaffs2_checkpt_find_block(dev);
 385                                 dev->checkpt_cur_chunk = 0;
 386                         }
 387
 388                         /* Bail out if we can't find a checpoint block */
 389                         if (dev->checkpt_cur_block < 0)
 390                                 break;
 391
 392                         chunk = dev->checkpt_cur_block *
 393                             dev->param.chunks_per_block +
 394                             dev->checkpt_cur_chunk;
 395
 396                         offset_chunk = apply_chunk_offset(dev, chunk);
 397                         dev->n_page_reads++;
 398
 399                         /* Read in the next chunk */
 400                         dev->tagger.read_chunk_tags_fn(dev,
 401                                                 offset_chunk,
 402                                                 dev->checkpt_buffer,
 403                                                 &tags);
 404
 405                         /* Bail out if the chunk is corrupted. */
 406                         if (tags.chunk_id != (dev->checkpt_page_seq + 1) ||
 407                             tags.ecc_result > YAFFS_ECC_RESULT_FIXED ||
 408                             tags.seq_number != YAFFS_SEQUENCE_CHECKPOINT_DATA)
 409                                 break;
 410
 411                         /* Bail out if it is not a checkpoint chunk. */
 412                         if(!yaffs2_checkpt_check_chunk_hdr(dev))
 413                                 break;
 414
 415                         dev->checkpt_page_seq++;
 416                         dev->checkpt_cur_chunk++;
 417
 418                         if (dev->checkpt_cur_chunk >=
 419                                         dev->param.chunks_per_block)
 420                                 dev->checkpt_cur_block = -1;
 421
 422                 }
 423
 424                 *data_bytes = dev->checkpt_buffer[dev->checkpt_byte_offs];
 425                 dev->checkpt_sum += *data_bytes;
 426                 dev->checkpt_xor ^= *data_bytes;
 427                 dev->checkpt_byte_offs++;
 428                 i++;
 429                 data_bytes++;
 430                 dev->checkpt_byte_count++;
 431         }
 432
 433         return i; /* Number of bytes read */
 434 }
 435
 436 int yaffs_checkpt_close(struct yaffs_dev *dev)
 437 {
 438         int i;
 439
 440         if (dev->checkpt_open_write) {
 441                 if (dev->checkpt_byte_offs !=
 442                         sizeof(sizeof(struct yaffs_checkpt_chunk_hdr)))
 443                         yaffs2_checkpt_flush_buffer(dev);
 444         } else if (dev->checkpt_block_list) {
 445                 for (i = 0;
 446                      i < dev->blocks_in_checkpt &&
 447                      dev->checkpt_block_list[i] >= 0; i++) {
 448                         int blk = dev->checkpt_block_list[i];
 449                         struct yaffs_block_info *bi = NULL;
 450
 451                         if (dev->internal_start_block <= blk &&
 452                             blk <= dev->internal_end_block)
 453                                 bi = yaffs_get_block_info(dev, blk);
 454                         if (bi && bi->block_state == YAFFS_BLOCK_STATE_EMPTY)
 455                                 bi->block_state = YAFFS_BLOCK_STATE_CHECKPOINT;
 456                 }
 457         }
 458
 459         dev->n_free_chunks -=
 460                 dev->blocks_in_checkpt * dev->param.chunks_per_block;
 461         dev->n_erased_blocks -= dev->blocks_in_checkpt;
 462
 463         yaffs_trace(YAFFS_TRACE_CHECKPOINT, "checkpoint byte count %d",
 464                 dev->checkpt_byte_count);
 465
 466         if (dev->checkpt_buffer)
 467                 return 1;
 468         else
 469                 return 0;
 470 }
 471
 472 int yaffs2_checkpt_invalidate_stream(struct yaffs_dev *dev)
 473 {
 474         /* Erase the checkpoint data */
 475
 476         yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 477                 "checkpoint invalidate of %d blocks",
 478                 dev->blocks_in_checkpt);
 479
 480         return yaffs_checkpt_erase(dev);
 481 }