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