uboot/fs/yaffs2/yaffs_checkptrw.c
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   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
  17static 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
  27static 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
  64static 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
  97static 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
 138int 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
 193int 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
 202static 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
 257int 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
 287int 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
 358int 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
 399int 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}
 409