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