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