target/linux/generic-2.6/files/fs/yaffs2/yaffs_checkptrw.c

   1 /*
   2  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
   3  *
   4  * Copyright (C) 2002-2007 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 const char *yaffs_checkptrw_c_version =
  15
  16
  17 #include "yaffs_checkptrw.h"
  18
  19
  20 static int yaffs_CheckpointSpaceOk(yaffs_Device *dev)
  21 {
  22
  23         int blocksAvailable = dev->nErasedBlocks - dev->nReservedBlocks;
  24
  25         T(YAFFS_TRACE_CHECKPOINT,
  26                 (TSTR("checkpt blocks available = %d" TENDSTR),
  27                 blocksAvailable));
  28
  29
  30         return (blocksAvailable <= 0) ? 0 : 1;
  31 }
  32
  33
  34 static int yaffs_CheckpointErase(yaffs_Device *dev)
  35 {
  36
  37         int i;
  38
  39
  40         if(!dev->eraseBlockInNAND)
  41                 return 0;
  42         T(YAFFS_TRACE_CHECKPOINT,(TSTR("checking blocks %d to %d"TENDSTR),
  43                 dev->internalStartBlock,dev->internalEndBlock));
  44
  45         for(i = dev->internalStartBlock; i <= dev->internalEndBlock; i++) {
  46                 yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev,i);
  47                 if(bi->blockState == YAFFS_BLOCK_STATE_CHECKPOINT){
  48                         T(YAFFS_TRACE_CHECKPOINT,(TSTR("erasing checkpt block %d"TENDSTR),i));
  49                         if(dev->eraseBlockInNAND(dev,i- dev->blockOffset /* realign */)){
  50                                 bi->blockState = YAFFS_BLOCK_STATE_EMPTY;
  51                                 dev->nErasedBlocks++;
  52                                 dev->nFreeChunks += dev->nChunksPerBlock;
  53                         }
  54                         else {
  55                                 dev->markNANDBlockBad(dev,i);
  56                                 bi->blockState = YAFFS_BLOCK_STATE_DEAD;
  57                         }
  58                 }
  59         }
  60
  61         dev->blocksInCheckpoint = 0;
  62
  63         return 1;
  64 }
  65
  66
  67 static void yaffs_CheckpointFindNextErasedBlock(yaffs_Device *dev)
  68 {
  69         int  i;
  70         int blocksAvailable = dev->nErasedBlocks - dev->nReservedBlocks;
  71         T(YAFFS_TRACE_CHECKPOINT,
  72                 (TSTR("allocating checkpt block: erased %d reserved %d avail %d next %d "TENDSTR),
  73                 dev->nErasedBlocks,dev->nReservedBlocks,blocksAvailable,dev->checkpointNextBlock));
  74
  75         if(dev->checkpointNextBlock >= 0 &&
  76            dev->checkpointNextBlock <= dev->internalEndBlock &&
  77            blocksAvailable > 0){
  78
  79                 for(i = dev->checkpointNextBlock; i <= dev->internalEndBlock; i++){
  80                         yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev,i);
  81                         if(bi->blockState == YAFFS_BLOCK_STATE_EMPTY){
  82                                 dev->checkpointNextBlock = i + 1;
  83                                 dev->checkpointCurrentBlock = i;
  84                                 T(YAFFS_TRACE_CHECKPOINT,(TSTR("allocating checkpt block %d"TENDSTR),i));
  85                                 return;
  86                         }
  87                 }
  88         }
  89         T(YAFFS_TRACE_CHECKPOINT,(TSTR("out of checkpt blocks"TENDSTR)));
  90
  91         dev->checkpointNextBlock = -1;
  92         dev->checkpointCurrentBlock = -1;
  93 }
  94
  95 static void yaffs_CheckpointFindNextCheckpointBlock(yaffs_Device *dev)
  96 {
  97         int  i;
  98         yaffs_ExtendedTags tags;
  99
 100         T(YAFFS_TRACE_CHECKPOINT,(TSTR("find next checkpt block: start:  blocks %d next %d" TENDSTR),
 101                 dev->blocksInCheckpoint, dev->checkpointNextBlock));
 102
 103         if(dev->blocksInCheckpoint < dev->checkpointMaxBlocks)
 104                 for(i = dev->checkpointNextBlock; i <= dev->internalEndBlock; i++){
 105                         int chunk = i * dev->nChunksPerBlock;
 106                         int realignedChunk = chunk - dev->chunkOffset;
 107
 108                         dev->readChunkWithTagsFromNAND(dev,realignedChunk,NULL,&tags);
 109                         T(YAFFS_TRACE_CHECKPOINT,(TSTR("find next checkpt block: search: block %d oid %d seq %d eccr %d" TENDSTR),
 110                                 i, tags.objectId,tags.sequenceNumber,tags.eccResult));
 111
 112                         if(tags.sequenceNumber == YAFFS_SEQUENCE_CHECKPOINT_DATA){
 113                                 /* Right kind of block */
 114                                 dev->checkpointNextBlock = tags.objectId;
 115                                 dev->checkpointCurrentBlock = i;
 116                                 dev->checkpointBlockList[dev->blocksInCheckpoint] = i;
 117                                 dev->blocksInCheckpoint++;
 118                                 T(YAFFS_TRACE_CHECKPOINT,(TSTR("found checkpt block %d"TENDSTR),i));
 119                                 return;
 120                         }
 121                 }
 122
 123         T(YAFFS_TRACE_CHECKPOINT,(TSTR("found no more checkpt blocks"TENDSTR)));
 124
 125         dev->checkpointNextBlock = -1;
 126         dev->checkpointCurrentBlock = -1;
 127 }
 128
 129
 130 int yaffs_CheckpointOpen(yaffs_Device *dev, int forWriting)
 131 {
 132
 133         /* Got the functions we need? */
 134         if (!dev->writeChunkWithTagsToNAND ||
 135             !dev->readChunkWithTagsFromNAND ||
 136             !dev->eraseBlockInNAND ||
 137             !dev->markNANDBlockBad)
 138                 return 0;
 139
 140         if(forWriting && !yaffs_CheckpointSpaceOk(dev))
 141                 return 0;
 142
 143         if(!dev->checkpointBuffer)
 144                 dev->checkpointBuffer = YMALLOC_DMA(dev->nDataBytesPerChunk);
 145         if(!dev->checkpointBuffer)
 146                 return 0;
 147
 148
 149         dev->checkpointPageSequence = 0;
 150
 151         dev->checkpointOpenForWrite = forWriting;
 152
 153         dev->checkpointByteCount = 0;
 154         dev->checkpointSum = 0;
 155         dev->checkpointXor = 0;
 156         dev->checkpointCurrentBlock = -1;
 157         dev->checkpointCurrentChunk = -1;
 158         dev->checkpointNextBlock = dev->internalStartBlock;
 159
 160         /* Erase all the blocks in the checkpoint area */
 161         if(forWriting){
 162                 memset(dev->checkpointBuffer,0,dev->nDataBytesPerChunk);
 163                 dev->checkpointByteOffset = 0;
 164                 return yaffs_CheckpointErase(dev);
 165
 166
 167         } else {
 168                 int i;
 169                 /* Set to a value that will kick off a read */
 170                 dev->checkpointByteOffset = dev->nDataBytesPerChunk;
 171                 /* A checkpoint block list of 1 checkpoint block per 16 block is (hopefully)
 172                  * going to be way more than we need */
 173                 dev->blocksInCheckpoint = 0;
 174                 dev->checkpointMaxBlocks = (dev->internalEndBlock - dev->internalStartBlock)/16 + 2;
 175                 dev->checkpointBlockList = YMALLOC(sizeof(int) * dev->checkpointMaxBlocks);
 176                 for(i = 0; i < dev->checkpointMaxBlocks; i++)
 177                         dev->checkpointBlockList[i] = -1;
 178         }
 179
 180         return 1;
 181 }
 182
 183 int yaffs_GetCheckpointSum(yaffs_Device *dev, __u32 *sum)
 184 {
 185         __u32 compositeSum;
 186         compositeSum =  (dev->checkpointSum << 8) | (dev->checkpointXor & 0xFF);
 187         *sum = compositeSum;
 188         return 1;
 189 }
 190
 191 static int yaffs_CheckpointFlushBuffer(yaffs_Device *dev)
 192 {
 193
 194         int chunk;
 195         int realignedChunk;
 196
 197         yaffs_ExtendedTags tags;
 198
 199         if(dev->checkpointCurrentBlock < 0){
 200                 yaffs_CheckpointFindNextErasedBlock(dev);
 201                 dev->checkpointCurrentChunk = 0;
 202         }
 203
 204         if(dev->checkpointCurrentBlock < 0)
 205                 return 0;
 206
 207         tags.chunkDeleted = 0;
 208         tags.objectId = dev->checkpointNextBlock; /* Hint to next place to look */
 209         tags.chunkId = dev->checkpointPageSequence + 1;
 210         tags.sequenceNumber =  YAFFS_SEQUENCE_CHECKPOINT_DATA;
 211         tags.byteCount = dev->nDataBytesPerChunk;
 212         if(dev->checkpointCurrentChunk == 0){
 213                 /* First chunk we write for the block? Set block state to
 214                    checkpoint */
 215                 yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev,dev->checkpointCurrentBlock);
 216                 bi->blockState = YAFFS_BLOCK_STATE_CHECKPOINT;
 217                 dev->blocksInCheckpoint++;
 218         }
 219
 220         chunk = dev->checkpointCurrentBlock * dev->nChunksPerBlock + dev->checkpointCurrentChunk;
 221
 222
 223         T(YAFFS_TRACE_CHECKPOINT,(TSTR("checkpoint wite buffer nand %d(%d:%d) objid %d chId %d" TENDSTR),
 224                 chunk, dev->checkpointCurrentBlock, dev->checkpointCurrentChunk,tags.objectId,tags.chunkId));
 225
 226         realignedChunk = chunk - dev->chunkOffset;
 227
 228         dev->writeChunkWithTagsToNAND(dev,realignedChunk,dev->checkpointBuffer,&tags);
 229         dev->checkpointByteOffset = 0;
 230         dev->checkpointPageSequence++;
 231         dev->checkpointCurrentChunk++;
 232         if(dev->checkpointCurrentChunk >= dev->nChunksPerBlock){
 233                 dev->checkpointCurrentChunk = 0;
 234                 dev->checkpointCurrentBlock = -1;
 235         }
 236         memset(dev->checkpointBuffer,0,dev->nDataBytesPerChunk);
 237
 238         return 1;
 239 }
 240
 241
 242 int yaffs_CheckpointWrite(yaffs_Device *dev,const void *data, int nBytes)
 243 {
 244         int i=0;
 245         int ok = 1;
 246
 247
 248         __u8 * dataBytes = (__u8 *)data;
 249
 250
 251
 252         if(!dev->checkpointBuffer)
 253                 return 0;
 254
 255         if(!dev->checkpointOpenForWrite)
 256                 return -1;
 257
 258         while(i < nBytes && ok) {
 259
 260
 261
 262                 dev->checkpointBuffer[dev->checkpointByteOffset] = *dataBytes ;
 263                 dev->checkpointSum += *dataBytes;
 264                 dev->checkpointXor ^= *dataBytes;
 265
 266                 dev->checkpointByteOffset++;
 267                 i++;
 268                 dataBytes++;
 269                 dev->checkpointByteCount++;
 270
 271
 272                 if(dev->checkpointByteOffset < 0 ||
 273                    dev->checkpointByteOffset >= dev->nDataBytesPerChunk)
 274                         ok = yaffs_CheckpointFlushBuffer(dev);
 275
 276         }
 277
 278         return  i;
 279 }
 280
 281 int yaffs_CheckpointRead(yaffs_Device *dev, void *data, int nBytes)
 282 {
 283         int i=0;
 284         int ok = 1;
 285         yaffs_ExtendedTags tags;
 286
 287
 288         int chunk;
 289         int realignedChunk;
 290
 291         __u8 *dataBytes = (__u8 *)data;
 292
 293         if(!dev->checkpointBuffer)
 294                 return 0;
 295
 296         if(dev->checkpointOpenForWrite)
 297                 return -1;
 298
 299         while(i < nBytes && ok) {
 300
 301
 302                 if(dev->checkpointByteOffset < 0 ||
 303                    dev->checkpointByteOffset >= dev->nDataBytesPerChunk) {
 304
 305                         if(dev->checkpointCurrentBlock < 0){
 306                                 yaffs_CheckpointFindNextCheckpointBlock(dev);
 307                                 dev->checkpointCurrentChunk = 0;
 308                         }
 309
 310                         if(dev->checkpointCurrentBlock < 0)
 311                                 ok = 0;
 312                         else {
 313
 314                                 chunk = dev->checkpointCurrentBlock * dev->nChunksPerBlock +
 315                                           dev->checkpointCurrentChunk;
 316
 317                                 realignedChunk = chunk - dev->chunkOffset;
 318
 319                                 /* read in the next chunk */
 320                                 /* printf("read checkpoint page %d\n",dev->checkpointPage); */
 321                                 dev->readChunkWithTagsFromNAND(dev, realignedChunk,
 322                                                                dev->checkpointBuffer,
 323                                                               &tags);
 324
 325                                 if(tags.chunkId != (dev->checkpointPageSequence + 1) ||
 326                                    tags.sequenceNumber != YAFFS_SEQUENCE_CHECKPOINT_DATA)
 327                                    ok = 0;
 328
 329                                 dev->checkpointByteOffset = 0;
 330                                 dev->checkpointPageSequence++;
 331                                 dev->checkpointCurrentChunk++;
 332
 333                                 if(dev->checkpointCurrentChunk >= dev->nChunksPerBlock)
 334                                         dev->checkpointCurrentBlock = -1;
 335                         }
 336                 }
 337
 338                 if(ok){
 339                         *dataBytes = dev->checkpointBuffer[dev->checkpointByteOffset];
 340                         dev->checkpointSum += *dataBytes;
 341                         dev->checkpointXor ^= *dataBytes;
 342                         dev->checkpointByteOffset++;
 343                         i++;
 344                         dataBytes++;
 345                         dev->checkpointByteCount++;
 346                 }
 347         }
 348
 349         return  i;
 350 }
 351
 352 int yaffs_CheckpointClose(yaffs_Device *dev)
 353 {
 354
 355         if(dev->checkpointOpenForWrite){
 356                 if(dev->checkpointByteOffset != 0)
 357                         yaffs_CheckpointFlushBuffer(dev);
 358         } else {
 359                 int i;
 360                 for(i = 0; i < dev->blocksInCheckpoint && dev->checkpointBlockList[i] >= 0; i++){
 361                         yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev,dev->checkpointBlockList[i]);
 362                         if(bi->blockState == YAFFS_BLOCK_STATE_EMPTY)
 363                                 bi->blockState = YAFFS_BLOCK_STATE_CHECKPOINT;
 364                         else {
 365                                 // Todo this looks odd...
 366                         }
 367                 }
 368                 YFREE(dev->checkpointBlockList);
 369                 dev->checkpointBlockList = NULL;
 370         }
 371
 372         dev->nFreeChunks -= dev->blocksInCheckpoint * dev->nChunksPerBlock;
 373         dev->nErasedBlocks -= dev->blocksInCheckpoint;
 374
 375
 376         T(YAFFS_TRACE_CHECKPOINT,(TSTR("checkpoint byte count %d" TENDSTR),
 377                         dev->checkpointByteCount));
 378
 379         if(dev->checkpointBuffer){
 380                 /* free the buffer */
 381                 YFREE(dev->checkpointBuffer);
 382                 dev->checkpointBuffer = NULL;
 383                 return 1;
 384         }
 385         else
 386                 return 0;
 387
 388 }
 389
 390 int yaffs_CheckpointInvalidateStream(yaffs_Device *dev)
 391 {
 392         /* Erase the first checksum block */
 393
 394         T(YAFFS_TRACE_CHECKPOINT,(TSTR("checkpoint invalidate"TENDSTR)));
 395
 396         if(!yaffs_CheckpointSpaceOk(dev))
 397                 return 0;
 398
 399         return yaffs_CheckpointErase(dev);
 400 }
 401
 402
 403