fs/yaffs2/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
 112                         dev->param.read_chunk_tags_fn(dev, realigned_chunk,
 113                                                       NULL, &tags);
 114                         yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 115                                 "find next checkpt block: search: block %d oid %d seq %d eccr %d",
 116                                 i, tags.obj_id, tags.seq_number,
 117                                 tags.ecc_result);
 118
 119                         if (tags.seq_number == YAFFS_SEQUENCE_CHECKPOINT_DATA) {
 120                                 /* Right kind of block */
 121                                 dev->checkpt_next_block = tags.obj_id;
 122                                 dev->checkpt_cur_block = i;
 123                                 dev->checkpt_block_list[dev->
 124                                                         blocks_in_checkpt] = i;
 125                                 dev->blocks_in_checkpt++;
 126                                 yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 127                                         "found checkpt block %d", i);
 128                                 return;
 129                         }
 130                 }
 131
 132         yaffs_trace(YAFFS_TRACE_CHECKPOINT, "found no more checkpt blocks");
 133
 134         dev->checkpt_next_block = -1;
 135         dev->checkpt_cur_block = -1;
 136 }
 137
 138 int yaffs2_checkpt_open(struct yaffs_dev *dev, int writing)
 139 {
 140         int i;
 141
 142         dev->checkpt_open_write = writing;
 143
 144         /* Got the functions we need? */
 145         if (!dev->param.write_chunk_tags_fn ||
 146             !dev->param.read_chunk_tags_fn ||
 147             !dev->param.erase_fn || !dev->param.bad_block_fn)
 148                 return 0;
 149
 150         if (writing && !yaffs2_checkpt_space_ok(dev))
 151                 return 0;
 152
 153         if (!dev->checkpt_buffer)
 154                 dev->checkpt_buffer =
 155                     kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
 156         if (!dev->checkpt_buffer)
 157                 return 0;
 158
 159         dev->checkpt_page_seq = 0;
 160         dev->checkpt_byte_count = 0;
 161         dev->checkpt_sum = 0;
 162         dev->checkpt_xor = 0;
 163         dev->checkpt_cur_block = -1;
 164         dev->checkpt_cur_chunk = -1;
 165         dev->checkpt_next_block = dev->internal_start_block;
 166
 167         /* Erase all the blocks in the checkpoint area */
 168         if (writing) {
 169                 memset(dev->checkpt_buffer, 0, dev->data_bytes_per_chunk);
 170                 dev->checkpt_byte_offs = 0;
 171                 return yaffs_checkpt_erase(dev);
 172         }
 173
 174         /* Set to a value that will kick off a read */
 175         dev->checkpt_byte_offs = dev->data_bytes_per_chunk;
 176         /* A checkpoint block list of 1 checkpoint block per 16 block is
 177          * (hopefully) going to be way more than we need */
 178         dev->blocks_in_checkpt = 0;
 179         dev->checkpt_max_blocks =
 180             (dev->internal_end_block - dev->internal_start_block) / 16 + 2;
 181         dev->checkpt_block_list =
 182             kmalloc(sizeof(int) * dev->checkpt_max_blocks, GFP_NOFS);
 183
 184         if (!dev->checkpt_block_list)
 185                 return 0;
 186
 187         for (i = 0; i < dev->checkpt_max_blocks; i++)
 188                 dev->checkpt_block_list[i] = -1;
 189
 190         return 1;
 191 }
 192
 193 int yaffs2_get_checkpt_sum(struct yaffs_dev *dev, u32 * sum)
 194 {
 195         u32 composite_sum;
 196
 197         composite_sum = (dev->checkpt_sum << 8) | (dev->checkpt_xor & 0xff);
 198         *sum = composite_sum;
 199         return 1;
 200 }
 201
 202 static int yaffs2_checkpt_flush_buffer(struct yaffs_dev *dev)
 203 {
 204         int chunk;
 205         int realigned_chunk;
 206         struct yaffs_ext_tags tags;
 207
 208         if (dev->checkpt_cur_block < 0) {
 209                 yaffs2_checkpt_find_erased_block(dev);
 210                 dev->checkpt_cur_chunk = 0;
 211         }
 212
 213         if (dev->checkpt_cur_block < 0)
 214                 return 0;
 215
 216         tags.is_deleted = 0;
 217         tags.obj_id = dev->checkpt_next_block;  /* Hint to next place to look */
 218         tags.chunk_id = dev->checkpt_page_seq + 1;
 219         tags.seq_number = YAFFS_SEQUENCE_CHECKPOINT_DATA;
 220         tags.n_bytes = dev->data_bytes_per_chunk;
 221         if (dev->checkpt_cur_chunk == 0) {
 222                 /* First chunk we write for the block? Set block state to
 223                    checkpoint */
 224                 struct yaffs_block_info *bi =
 225                     yaffs_get_block_info(dev, dev->checkpt_cur_block);
 226                 bi->block_state = YAFFS_BLOCK_STATE_CHECKPOINT;
 227                 dev->blocks_in_checkpt++;
 228         }
 229
 230         chunk =
 231             dev->checkpt_cur_block * dev->param.chunks_per_block +
 232             dev->checkpt_cur_chunk;
 233
 234         yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 235                 "checkpoint wite buffer nand %d(%d:%d) objid %d chId %d",
 236                 chunk, dev->checkpt_cur_block, dev->checkpt_cur_chunk,
 237                 tags.obj_id, tags.chunk_id);
 238
 239         realigned_chunk = chunk - dev->chunk_offset;
 240
 241         dev->n_page_writes++;
 242
 243         dev->param.write_chunk_tags_fn(dev, realigned_chunk,
 244                                        dev->checkpt_buffer, &tags);
 245         dev->checkpt_byte_offs = 0;
 246         dev->checkpt_page_seq++;
 247         dev->checkpt_cur_chunk++;
 248         if (dev->checkpt_cur_chunk >= dev->param.chunks_per_block) {
 249                 dev->checkpt_cur_chunk = 0;
 250                 dev->checkpt_cur_block = -1;
 251         }
 252         memset(dev->checkpt_buffer, 0, dev->data_bytes_per_chunk);
 253
 254         return 1;
 255 }
 256
 257 int yaffs2_checkpt_wr(struct yaffs_dev *dev, const void *data, int n_bytes)
 258 {
 259         int i = 0;
 260         int ok = 1;
 261         u8 *data_bytes = (u8 *) data;
 262
 263         if (!dev->checkpt_buffer)
 264                 return 0;
 265
 266         if (!dev->checkpt_open_write)
 267                 return -1;
 268
 269         while (i < n_bytes && ok) {
 270                 dev->checkpt_buffer[dev->checkpt_byte_offs] = *data_bytes;
 271                 dev->checkpt_sum += *data_bytes;
 272                 dev->checkpt_xor ^= *data_bytes;
 273
 274                 dev->checkpt_byte_offs++;
 275                 i++;
 276                 data_bytes++;
 277                 dev->checkpt_byte_count++;
 278
 279                 if (dev->checkpt_byte_offs < 0 ||
 280                     dev->checkpt_byte_offs >= dev->data_bytes_per_chunk)
 281                         ok = yaffs2_checkpt_flush_buffer(dev);
 282         }
 283
 284         return i;
 285 }
 286
 287 int yaffs2_checkpt_rd(struct yaffs_dev *dev, void *data, int n_bytes)
 288 {
 289         int i = 0;
 290         int ok = 1;
 291         struct yaffs_ext_tags tags;
 292         int chunk;
 293         int realigned_chunk;
 294         u8 *data_bytes = (u8 *) data;
 295
 296         if (!dev->checkpt_buffer)
 297                 return 0;
 298
 299         if (dev->checkpt_open_write)
 300                 return -1;
 301
 302         while (i < n_bytes && ok) {
 303
 304                 if (dev->checkpt_byte_offs < 0 ||
 305                     dev->checkpt_byte_offs >= dev->data_bytes_per_chunk) {
 306
 307                         if (dev->checkpt_cur_block < 0) {
 308                                 yaffs2_checkpt_find_block(dev);
 309                                 dev->checkpt_cur_chunk = 0;
 310                         }
 311
 312                         if (dev->checkpt_cur_block < 0) {
 313                                 ok = 0;
 314                                 break;
 315                         }
 316
 317                         chunk = dev->checkpt_cur_block *
 318                             dev->param.chunks_per_block +
 319                             dev->checkpt_cur_chunk;
 320
 321                         realigned_chunk = chunk - dev->chunk_offset;
 322                         dev->n_page_reads++;
 323
 324                         /* read in the next chunk */
 325                         dev->param.read_chunk_tags_fn(dev,
 326                                                 realigned_chunk,
 327                                                 dev->checkpt_buffer,
 328                                                 &tags);
 329
 330                         if (tags.chunk_id != (dev->checkpt_page_seq + 1) ||
 331                             tags.ecc_result > YAFFS_ECC_RESULT_FIXED ||
 332                             tags.seq_number != YAFFS_SEQUENCE_CHECKPOINT_DATA) {
 333                                 ok = 0;
 334                                 break;
 335                         }
 336
 337                         dev->checkpt_byte_offs = 0;
 338                         dev->checkpt_page_seq++;
 339                         dev->checkpt_cur_chunk++;
 340
 341                         if (dev->checkpt_cur_chunk >=
 342                                         dev->param.chunks_per_block)
 343                                 dev->checkpt_cur_block = -1;
 344                 }
 345
 346                 *data_bytes = dev->checkpt_buffer[dev->checkpt_byte_offs];
 347                 dev->checkpt_sum += *data_bytes;
 348                 dev->checkpt_xor ^= *data_bytes;
 349                 dev->checkpt_byte_offs++;
 350                 i++;
 351                 data_bytes++;
 352                 dev->checkpt_byte_count++;
 353         }
 354
 355         return i;
 356 }
 357
 358 int yaffs_checkpt_close(struct yaffs_dev *dev)
 359 {
 360         int i;
 361
 362         if (dev->checkpt_open_write) {
 363                 if (dev->checkpt_byte_offs != 0)
 364                         yaffs2_checkpt_flush_buffer(dev);
 365         } else if (dev->checkpt_block_list) {
 366                 for (i = 0;
 367                      i < dev->blocks_in_checkpt &&
 368                      dev->checkpt_block_list[i] >= 0; i++) {
 369                         int blk = dev->checkpt_block_list[i];
 370                         struct yaffs_block_info *bi = NULL;
 371
 372                         if (dev->internal_start_block <= blk &&
 373                             blk <= dev->internal_end_block)
 374                                 bi = yaffs_get_block_info(dev, blk);
 375                         if (bi && bi->block_state == YAFFS_BLOCK_STATE_EMPTY)
 376                                 bi->block_state = YAFFS_BLOCK_STATE_CHECKPOINT;
 377                 }
 378                 kfree(dev->checkpt_block_list);
 379                 dev->checkpt_block_list = NULL;
 380         }
 381
 382         dev->n_free_chunks -=
 383                 dev->blocks_in_checkpt * dev->param.chunks_per_block;
 384         dev->n_erased_blocks -= dev->blocks_in_checkpt;
 385
 386         yaffs_trace(YAFFS_TRACE_CHECKPOINT, "checkpoint byte count %d",
 387                 dev->checkpt_byte_count);
 388
 389         if (dev->checkpt_buffer) {
 390                 /* free the buffer */
 391                 kfree(dev->checkpt_buffer);
 392                 dev->checkpt_buffer = NULL;
 393                 return 1;
 394         } else {
 395                 return 0;
 396         }
 397 }
 398
 399 int yaffs2_checkpt_invalidate_stream(struct yaffs_dev *dev)
 400 {
 401         /* Erase the checkpoint data */
 402
 403         yaffs_trace(YAFFS_TRACE_CHECKPOINT,
 404                 "checkpoint invalidate of %d blocks",
 405                 dev->blocks_in_checkpt);
 406
 407         return yaffs_checkpt_erase(dev);
 408 }