lib/ext2fs/sparse_io.c

   1 #include "config.h"
   2 #include <sys/types.h>
   3 #include <sys/stat.h>
   4 #include <fcntl.h>
   5 #include <unistd.h>
   6 #include <stdint.h>
   7 #include "ext2_fs.h"
   8 #include "ext2fs.h"
   9
  10 #ifndef O_BINARY
  11 #define O_BINARY 0
  12 #endif
  13
  14 #if !defined(ENABLE_LIBSPARSE)
  15 static errcode_t sparse_open(const char *name EXT2FS_ATTR((unused)),
  16                              int flags EXT2FS_ATTR((unused)),
  17                              io_channel *channel EXT2FS_ATTR((unused)))
  18 {
  19         return EXT2_ET_UNIMPLEMENTED;
  20 }
  21 static errcode_t sparse_close(io_channel channel EXT2FS_ATTR((unused)))
  22 {
  23         return EXT2_ET_UNIMPLEMENTED;
  24 }
  25 static struct struct_io_manager struct_sparse_manager = {
  26         .magic                  = EXT2_ET_MAGIC_IO_MANAGER,
  27         .name                   = "Android sparse I/O Manager",
  28         .open                   = sparse_open,
  29         .close                  = sparse_close,
  30 };
  31 static struct struct_io_manager struct_sparsefd_manager = {
  32         .magic                  = EXT2_ET_MAGIC_IO_MANAGER,
  33         .name                   = "Android sparse fd I/O Manager",
  34         .open                   = sparse_open,
  35         .close                  = sparse_close,
  36 };
  37 #else
  38 #include <sparse/sparse.h>
  39
  40 struct sparse_map {
  41         int                     fd;
  42         char                    **blocks;
  43         int                     block_size;
  44         uint64_t                blocks_count;
  45         char                    *file;
  46         struct sparse_file      *sparse_file;
  47         io_channel              channel;
  48 };
  49
  50 struct sparse_io_params {
  51         int                     fd;
  52         char                    *file;
  53         uint64_t                blocks_count;
  54         unsigned int            block_size;
  55 };
  56
  57 static errcode_t sparse_write_blk(io_channel channel, unsigned long block,
  58                                   int count, const void *buf);
  59
  60 static void free_sparse_blocks(struct sparse_map *sm)
  61 {
  62         uint64_t i;
  63
  64         for (i = 0; i < sm->blocks_count; ++i)
  65                 free(sm->blocks[i]);
  66         free(sm->blocks);
  67         sm->blocks = NULL;
  68 }
  69
  70 static int sparse_import_segment(void *priv, const void *data, int len,
  71                                  unsigned int block, unsigned int nr_blocks)
  72 {
  73         struct sparse_map *sm = priv;
  74
  75         /* Ignore chunk headers, only write the data */
  76         if (!nr_blocks || len % sm->block_size)
  77                 return 0;
  78
  79         return sparse_write_blk(sm->channel, block, nr_blocks, data);
  80 }
  81
  82 static errcode_t io_manager_import_sparse(struct sparse_io_params *params,
  83                                           struct sparse_map *sm, io_channel io)
  84 {
  85         int fd;
  86         errcode_t retval;
  87         struct sparse_file *sparse_file;
  88
  89         if (params->fd < 0) {
  90                 fd = open(params->file, O_RDONLY);
  91                 if (fd < 0) {
  92                         retval = -1;
  93                         goto err_open;
  94                 }
  95         } else
  96                 fd = params->fd;
  97         sparse_file = sparse_file_import(fd, false, false);
  98         if (!sparse_file) {
  99                 retval = -1;
 100                 goto err_sparse;
 101         }
 102
 103         sm->block_size = sparse_file_block_size(sparse_file);
 104         sm->blocks_count = (sparse_file_len(sparse_file, 0, 0) - 1)
 105                                 / sm->block_size + 1;
 106         sm->blocks = calloc(sm->blocks_count, sizeof(char*));
 107         if (!sm->blocks) {
 108                 retval = -1;
 109                 goto err_alloc;
 110         }
 111         io->block_size = sm->block_size;
 112
 113         retval = sparse_file_foreach_chunk(sparse_file, true, false,
 114                                            sparse_import_segment, sm);
 115
 116         if (retval)
 117                 free_sparse_blocks(sm);
 118 err_alloc:
 119         sparse_file_destroy(sparse_file);
 120 err_sparse:
 121         close(fd);
 122 err_open:
 123         return retval;
 124 }
 125
 126 static errcode_t io_manager_configure(struct sparse_io_params *params,
 127                                       int flags, io_channel io)
 128 {
 129         errcode_t retval;
 130         uint64_t img_size;
 131         struct sparse_map *sm = calloc(1, sizeof(*sm));
 132         if (!sm)
 133                 return EXT2_ET_NO_MEMORY;
 134
 135         sm->file = params->file;
 136         sm->channel = io;
 137         io->private_data = sm;
 138         retval = io_manager_import_sparse(params, sm, io);
 139         if (retval) {
 140                 if (!params->block_size || !params->blocks_count) {
 141                         retval = -EINVAL;
 142                         goto err_params;
 143                 }
 144                 sm->block_size = params->block_size;
 145                 sm->blocks_count = params->blocks_count;
 146                 sm->blocks = calloc(params->blocks_count, sizeof(void*));
 147                 if (!sm->blocks) {
 148                         retval = EXT2_ET_NO_MEMORY;
 149                         goto err_alloc;
 150                 }
 151         }
 152         io->block_size = sm->block_size;
 153         img_size = (uint64_t)sm->block_size * sm->blocks_count;
 154
 155         if (flags & IO_FLAG_RW) {
 156                 sm->sparse_file = sparse_file_new(sm->block_size, img_size);
 157                 if (!sm->sparse_file) {
 158                         retval = EXT2_ET_NO_MEMORY;
 159                         goto err_alloc;
 160                 }
 161                 if (params->fd < 0) {
 162                         sm->fd = open(params->file, O_CREAT | O_RDWR | O_TRUNC | O_BINARY,
 163                                       0644);
 164                         if (sm->fd < 0) {
 165                                 retval = errno;
 166                                 goto err_open;
 167                         }
 168                 } else
 169                         sm->fd = params->fd;
 170         } else {
 171                 sm->fd = -1;
 172                 sm->sparse_file = NULL;
 173         }
 174         return 0;
 175
 176 err_open:
 177         sparse_file_destroy(sm->sparse_file);
 178 err_alloc:
 179         free_sparse_blocks(sm);
 180 err_params:
 181         free(sm);
 182         return retval;
 183 }
 184
 185 static errcode_t sparse_open_channel(struct sparse_io_params *sparse_params,
 186                                      int flags, io_channel *channel)
 187 {
 188         io_channel io;
 189
 190         io = calloc(1, sizeof(struct struct_io_channel));
 191         io->magic = EXT2_ET_MAGIC_IO_CHANNEL;
 192         io->block_size = 0;
 193         io->refcount = 1;
 194         *channel = io;
 195         return io_manager_configure(sparse_params, flags, io);
 196 }
 197
 198 static errcode_t read_sparse_argv(const char *name, bool is_fd,
 199                                   struct sparse_io_params *sparse_params)
 200 {
 201         int ret;
 202         sparse_params->fd = -1;
 203         sparse_params->block_size = 0;
 204         sparse_params->blocks_count = 0;
 205
 206         sparse_params->file = malloc(strlen(name) + 1);
 207         if (!sparse_params->file) {
 208                 fprintf(stderr, "failed to alloc %zu\n", strlen(name) + 1);
 209                 return EXT2_ET_NO_MEMORY;
 210         }
 211
 212         if (is_fd) {
 213                 ret = sscanf(name, "(%d):%llu:%u", &sparse_params->fd,
 214                              (unsigned long long *)&sparse_params->blocks_count,
 215                              &sparse_params->block_size);
 216         } else {
 217                 ret = sscanf(name, "(%[^)])%*[:]%llu%*[:]%u", sparse_params->file,
 218                              (unsigned long long *)&sparse_params->blocks_count,
 219                              &sparse_params->block_size);
 220         }
 221
 222         if (ret < 1) {
 223                 free(sparse_params->file);
 224                 return -EINVAL;
 225         }
 226         return 0;
 227 }
 228
 229 static errcode_t sparse_open(const char *name, int flags, io_channel *channel)
 230 {
 231         errcode_t retval;
 232         struct sparse_io_params sparse_params;
 233
 234         retval = read_sparse_argv(name, false, &sparse_params);
 235         if (retval)
 236                 return EXT2_ET_BAD_DEVICE_NAME;
 237
 238         retval = sparse_open_channel(&sparse_params, flags, channel);
 239         if (retval)
 240                 return retval;
 241         (*channel)->manager = sparse_io_manager;
 242
 243         return retval;
 244 }
 245
 246 static errcode_t sparsefd_open(const char *name, int flags, io_channel *channel)
 247 {
 248         errcode_t retval;
 249         struct sparse_io_params sparse_params;
 250
 251         retval = read_sparse_argv(name, true, &sparse_params);
 252         if (retval)
 253                 return EXT2_ET_BAD_DEVICE_NAME;
 254
 255         retval = sparse_open_channel(&sparse_params, flags, channel);
 256         if (retval)
 257                 return retval;
 258         (*channel)->manager = sparsefd_io_manager;
 259
 260         return retval;
 261 }
 262
 263 static errcode_t sparse_merge_blocks(struct sparse_map *sm, uint64_t start,
 264                                         uint64_t num)
 265 {
 266         char *buf;
 267         uint64_t i;
 268         unsigned int block_size = sm->block_size;
 269         errcode_t retval = 0;
 270
 271         buf = calloc(num, block_size);
 272         if (!buf) {
 273                 fprintf(stderr, "failed to alloc %llu\n",
 274                         (unsigned long long)num * block_size);
 275                 return EXT2_ET_NO_MEMORY;
 276         }
 277
 278         for (i = 0; i < num; i++) {
 279                 memcpy(buf + i * block_size, sm->blocks[start + i] , block_size);
 280                 free(sm->blocks[start + i]);
 281                 sm->blocks[start + i] = NULL;
 282         }
 283
 284         /* free_sparse_blocks will release this buf. */
 285         sm->blocks[start] = buf;
 286
 287         retval = sparse_file_add_data(sm->sparse_file, sm->blocks[start],
 288                                         block_size * num, start);
 289
 290         return retval;
 291 }
 292
 293 static errcode_t sparse_close_channel(io_channel channel)
 294 {
 295         uint64_t i;
 296         errcode_t retval = 0;
 297         struct sparse_map *sm = channel->private_data;
 298
 299         if (sm->sparse_file) {
 300                 int64_t chunk_start = (sm->blocks[0] == NULL) ? -1 : 0;
 301                 for (i = 0; i < sm->blocks_count; ++i) {
 302                         if (!sm->blocks[i] && chunk_start != -1) {
 303                                 retval = sparse_merge_blocks(sm, chunk_start, i - chunk_start);
 304                                 chunk_start = -1;
 305                         } else if (sm->blocks[i] && chunk_start == -1) {
 306                                 chunk_start = i;
 307                         }
 308                         if (retval)
 309                                 goto ret;
 310                 }
 311                 if (chunk_start != -1) {
 312                         retval = sparse_merge_blocks(sm, chunk_start,
 313                                                         sm->blocks_count - chunk_start);
 314                         if (retval)
 315                                 goto ret;
 316                 }
 317                 retval = sparse_file_write(sm->sparse_file, sm->fd,
 318                                            /*gzip*/0, /*sparse*/1, /*crc*/0);
 319         }
 320
 321 ret:
 322         if (sm->sparse_file)
 323                 sparse_file_destroy(sm->sparse_file);
 324         free_sparse_blocks(sm);
 325         free(sm->file);
 326         free(sm);
 327         free(channel);
 328         return retval;
 329 }
 330
 331 static errcode_t sparse_close(io_channel channel)
 332 {
 333         errcode_t retval;
 334         struct sparse_map *sm = channel->private_data;
 335         int fd = sm->fd;
 336
 337         retval = sparse_close_channel(channel);
 338         if (fd >= 0)
 339                 close(fd);
 340
 341         return retval;
 342 }
 343
 344 static errcode_t sparse_set_blksize(io_channel channel, int blksize)
 345 {
 346         channel->block_size = blksize;
 347         return 0;
 348 }
 349
 350 static blk64_t block_to_sparse_block(blk64_t block, blk64_t *offset,
 351                                io_channel channel, struct sparse_map *sm)
 352 {
 353         int ratio;
 354         blk64_t ret = block;
 355
 356         ratio = sm->block_size / channel->block_size;
 357         ret /= ratio;
 358         *offset = (block % ratio) * channel->block_size;
 359
 360         return ret;
 361 }
 362
 363 static errcode_t check_block_size(io_channel channel, struct sparse_map *sm)
 364 {
 365         if (sm->block_size >= channel->block_size)
 366                 return 0;
 367         return EXT2_ET_UNEXPECTED_BLOCK_SIZE;
 368 }
 369
 370 static errcode_t sparse_read_blk64(io_channel channel, blk64_t block,
 371                                    int count, void *buf)
 372 {
 373         int i;
 374         char *out = buf;
 375         blk64_t offset = 0, cur_block;
 376         struct sparse_map *sm = channel->private_data;
 377
 378         if (check_block_size(channel, sm))
 379                 return EXT2_ET_UNEXPECTED_BLOCK_SIZE;
 380
 381         if (count < 0) { //partial read
 382                 count = -count;
 383                 cur_block = block_to_sparse_block(block, &offset, channel, sm);
 384                 if (sm->blocks[cur_block])
 385                         memcpy(out, (sm->blocks[cur_block]) + offset, count);
 386                 else
 387                         memset(out, 0, count);
 388         } else {
 389                 for (i = 0; i < count; ++i) {
 390                         cur_block = block_to_sparse_block(block + i, &offset,
 391                                                     channel, sm);
 392                         if (sm->blocks[cur_block])
 393                                 memcpy(out + (i * channel->block_size),
 394                                        sm->blocks[cur_block] + offset,
 395                                        channel->block_size);
 396                         else if (sm->blocks)
 397                                 memset(out + (i * channel->block_size), 0,
 398                                        channel->block_size);
 399                 }
 400         }
 401         return 0;
 402 }
 403
 404 static errcode_t sparse_read_blk(io_channel channel, unsigned long block,
 405                                  int count, void *buf)
 406 {
 407         return sparse_read_blk64(channel, block, count, buf);
 408 }
 409
 410 static errcode_t sparse_write_blk64(io_channel channel, blk64_t block,
 411                                     int count, const void *buf)
 412 {
 413         int i;
 414         blk64_t offset = 0, cur_block;
 415         const char *in = buf;
 416         struct sparse_map *sm = channel->private_data;
 417
 418         if (check_block_size(channel, sm))
 419                 return EXT2_ET_UNEXPECTED_BLOCK_SIZE;
 420
 421         if (count < 0) { //partial write
 422                 count = -count;
 423                 cur_block = block_to_sparse_block(block, &offset, channel,
 424                                                   sm);
 425                 if (!sm->blocks[cur_block]) {
 426                         sm->blocks[cur_block] = calloc(1, sm->block_size);
 427                         if (!sm->blocks[cur_block])
 428                                 return EXT2_ET_NO_MEMORY;
 429                 }
 430                 memcpy(sm->blocks[cur_block] + offset, in, count);
 431         } else {
 432                 for (i = 0; i < count; ++i) {
 433                         if (block + i >= sm->blocks_count)
 434                                 return 0;
 435                         cur_block = block_to_sparse_block(block + i, &offset,
 436                                                     channel, sm);
 437                         if (!sm->blocks[cur_block]) {
 438                                 sm->blocks[cur_block] =
 439                                         calloc(1, sm->block_size);
 440                                 if (!sm->blocks[cur_block])
 441                                         return EXT2_ET_NO_MEMORY;
 442                         }
 443                         memcpy(sm->blocks[cur_block] + offset,
 444                                in + (i * channel->block_size),
 445                                channel->block_size);
 446                 }
 447         }
 448         return 0;
 449 }
 450
 451 static errcode_t sparse_write_blk(io_channel channel, unsigned long block,
 452                                   int count, const void *buf)
 453 {
 454         return sparse_write_blk64(channel, block, count, buf);
 455 }
 456
 457 static errcode_t sparse_discard(io_channel channel __attribute__((unused)),
 458                                 blk64_t blk, unsigned long long count)
 459 {
 460         blk64_t cur_block, offset;
 461         struct sparse_map *sm = channel->private_data;
 462
 463         if (check_block_size(channel, sm))
 464                 return EXT2_ET_UNEXPECTED_BLOCK_SIZE;
 465
 466         for (unsigned long long i = 0; i < count; ++i) {
 467                 if (blk + i >= sm->blocks_count)
 468                         return 0;
 469                 cur_block = block_to_sparse_block(blk + i, &offset, channel,
 470                                                   sm);
 471                 if (!sm->blocks[cur_block])
 472                         continue;
 473                 free(sm->blocks[cur_block]);
 474                 sm->blocks[cur_block] = NULL;
 475         }
 476         return 0;
 477 }
 478
 479 static errcode_t sparse_zeroout(io_channel channel, blk64_t blk,
 480                                 unsigned long long count)
 481 {
 482         return sparse_discard(channel, blk, count);
 483 }
 484
 485 static errcode_t sparse_flush(io_channel channel __attribute__((unused)))
 486 {
 487         return 0;
 488 }
 489
 490 static errcode_t sparse_set_option(io_channel channel __attribute__((unused)),
 491                                    const char *option __attribute__((unused)),
 492                                    const char *arg __attribute__((unused)))
 493 {
 494         return 0;
 495 }
 496
 497 static errcode_t sparse_cache_readahead(
 498                         io_channel channel __attribute__((unused)),
 499                         blk64_t blk __attribute__((unused)),
 500                         unsigned long long count __attribute__((unused)))
 501 {
 502         return 0;
 503 }
 504
 505 static struct struct_io_manager struct_sparse_manager = {
 506         .magic                  = EXT2_ET_MAGIC_IO_MANAGER,
 507         .name                   = "Android sparse I/O Manager",
 508         .open                   = sparse_open,
 509         .close                  = sparse_close,
 510         .set_blksize            = sparse_set_blksize,
 511         .read_blk               = sparse_read_blk,
 512         .write_blk              = sparse_write_blk,
 513         .flush                  = sparse_flush,
 514         .write_byte             = NULL,
 515         .set_option             = sparse_set_option,
 516         .get_stats              = NULL,
 517         .read_blk64             = sparse_read_blk64,
 518         .write_blk64            = sparse_write_blk64,
 519         .discard                = sparse_discard,
 520         .cache_readahead        = sparse_cache_readahead,
 521         .zeroout                = sparse_zeroout,
 522 };
 523
 524 static struct struct_io_manager struct_sparsefd_manager = {
 525         .magic                  = EXT2_ET_MAGIC_IO_MANAGER,
 526         .name                   = "Android sparse fd I/O Manager",
 527         .open                   = sparsefd_open,
 528         .close                  = sparse_close,
 529         .set_blksize            = sparse_set_blksize,
 530         .read_blk               = sparse_read_blk,
 531         .write_blk              = sparse_write_blk,
 532         .flush                  = sparse_flush,
 533         .write_byte             = NULL,
 534         .set_option             = sparse_set_option,
 535         .get_stats              = NULL,
 536         .read_blk64             = sparse_read_blk64,
 537         .write_blk64            = sparse_write_blk64,
 538         .discard                = sparse_discard,
 539         .cache_readahead        = sparse_cache_readahead,
 540         .zeroout                = sparse_zeroout,
 541 };
 542
 543 #endif
 544
 545 io_manager sparse_io_manager = &struct_sparse_manager;
 546 io_manager sparsefd_io_manager = &struct_sparsefd_manager;