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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 | // SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (C) 2015 Google, Inc. * * Author: Sami Tolvanen <samitolvanen@google.com> */ #include "dm-verity-fec.h" #include <linux/math64.h> #define DM_MSG_PREFIX "verity-fec" /* * If error correction has been configured, returns true. */ bool verity_fec_is_enabled(struct dm_verity *v) { return v->fec && v->fec->dev; } /* * Return a pointer to dm_verity_fec_io after dm_verity_io and its variable * length fields. */ static inline struct dm_verity_fec_io *fec_io(struct dm_verity_io *io) { return (struct dm_verity_fec_io *) verity_io_digest_end(io->v, io); } /* * Return an interleaved offset for a byte in RS block. */ static inline u64 fec_interleave(struct dm_verity *v, u64 offset) { u32 mod; mod = do_div(offset, v->fec->rsn); return offset + mod * (v->fec->rounds << v->data_dev_block_bits); } /* * Decode an RS block using Reed-Solomon. */ static int fec_decode_rs8(struct dm_verity *v, struct dm_verity_fec_io *fio, u8 *data, u8 *fec, int neras) { int i; uint16_t par[DM_VERITY_FEC_RSM - DM_VERITY_FEC_MIN_RSN]; for (i = 0; i < v->fec->roots; i++) par[i] = fec[i]; return decode_rs8(fio->rs, data, par, v->fec->rsn, NULL, neras, fio->erasures, 0, NULL); } /* * Read error-correcting codes for the requested RS block. Returns a pointer * to the data block. Caller is responsible for releasing buf. */ static u8 *fec_read_parity(struct dm_verity *v, u64 rsb, int index, unsigned int *offset, struct dm_buffer **buf) { u64 position, block, rem; u8 *res; position = (index + rsb) * v->fec->roots; block = div64_u64_rem(position, v->fec->io_size, &rem); *offset = (unsigned int)rem; res = dm_bufio_read(v->fec->bufio, block, buf); if (IS_ERR(res)) { DMERR("%s: FEC %llu: parity read failed (block %llu): %ld", v->data_dev->name, (unsigned long long)rsb, (unsigned long long)block, PTR_ERR(res)); *buf = NULL; } return res; } /* Loop over each preallocated buffer slot. */ #define fec_for_each_prealloc_buffer(__i) \ for (__i = 0; __i < DM_VERITY_FEC_BUF_PREALLOC; __i++) /* Loop over each extra buffer slot. */ #define fec_for_each_extra_buffer(io, __i) \ for (__i = DM_VERITY_FEC_BUF_PREALLOC; __i < DM_VERITY_FEC_BUF_MAX; __i++) /* Loop over each allocated buffer. */ #define fec_for_each_buffer(io, __i) \ for (__i = 0; __i < (io)->nbufs; __i++) /* Loop over each RS block in each allocated buffer. */ #define fec_for_each_buffer_rs_block(io, __i, __j) \ fec_for_each_buffer(io, __i) \ for (__j = 0; __j < 1 << DM_VERITY_FEC_BUF_RS_BITS; __j++) /* * Return a pointer to the current RS block when called inside * fec_for_each_buffer_rs_block. */ static inline u8 *fec_buffer_rs_block(struct dm_verity *v, struct dm_verity_fec_io *fio, unsigned int i, unsigned int j) { return &fio->bufs[i][j * v->fec->rsn]; } /* * Return an index to the current RS block when called inside * fec_for_each_buffer_rs_block. */ static inline unsigned int fec_buffer_rs_index(unsigned int i, unsigned int j) { return (i << DM_VERITY_FEC_BUF_RS_BITS) + j; } /* * Decode all RS blocks from buffers and copy corrected bytes into fio->output * starting from block_offset. */ static int fec_decode_bufs(struct dm_verity *v, struct dm_verity_fec_io *fio, u64 rsb, int byte_index, unsigned int block_offset, int neras) { int r, corrected = 0, res; struct dm_buffer *buf; unsigned int n, i, offset; u8 *par, *block; par = fec_read_parity(v, rsb, block_offset, &offset, &buf); if (IS_ERR(par)) return PTR_ERR(par); /* * Decode the RS blocks we have in bufs. Each RS block results in * one corrected target byte and consumes fec->roots parity bytes. */ fec_for_each_buffer_rs_block(fio, n, i) { block = fec_buffer_rs_block(v, fio, n, i); res = fec_decode_rs8(v, fio, block, &par[offset], neras); if (res < 0) { r = res; goto error; } corrected += res; fio->output[block_offset] = block[byte_index]; block_offset++; if (block_offset >= 1 << v->data_dev_block_bits) goto done; /* read the next block when we run out of parity bytes */ offset += v->fec->roots; if (offset >= v->fec->io_size) { dm_bufio_release(buf); par = fec_read_parity(v, rsb, block_offset, &offset, &buf); if (IS_ERR(par)) return PTR_ERR(par); } } done: r = corrected; error: dm_bufio_release(buf); if (r < 0 && neras) DMERR_LIMIT("%s: FEC %llu: failed to correct: %d", v->data_dev->name, (unsigned long long)rsb, r); else if (r > 0) DMWARN_LIMIT("%s: FEC %llu: corrected %d errors", v->data_dev->name, (unsigned long long)rsb, r); return r; } /* * Locate data block erasures using verity hashes. */ static int fec_is_erasure(struct dm_verity *v, struct dm_verity_io *io, u8 *want_digest, u8 *data) { if (unlikely(verity_hash(v, verity_io_hash_req(v, io), data, 1 << v->data_dev_block_bits, verity_io_real_digest(v, io)))) return 0; return memcmp(verity_io_real_digest(v, io), want_digest, v->digest_size) != 0; } /* * Read data blocks that are part of the RS block and deinterleave as much as * fits into buffers. Check for erasure locations if @neras is non-NULL. */ static int fec_read_bufs(struct dm_verity *v, struct dm_verity_io *io, u64 rsb, u64 target, unsigned int block_offset, int *neras) { bool is_zero; int i, j, target_index = -1; struct dm_buffer *buf; struct dm_bufio_client *bufio; struct dm_verity_fec_io *fio = fec_io(io); u64 block, ileaved; u8 *bbuf, *rs_block; u8 want_digest[HASH_MAX_DIGESTSIZE]; unsigned int n, k; if (neras) *neras = 0; if (WARN_ON(v->digest_size > sizeof(want_digest))) return -EINVAL; /* * read each of the rsn data blocks that are part of the RS block, and * interleave contents to available bufs */ for (i = 0; i < v->fec->rsn; i++) { ileaved = fec_interleave(v, rsb * v->fec->rsn + i); /* * target is the data block we want to correct, target_index is * the index of this block within the rsn RS blocks */ if (ileaved == target) target_index = i; block = ileaved >> v->data_dev_block_bits; bufio = v->fec->data_bufio; if (block >= v->data_blocks) { block -= v->data_blocks; /* * blocks outside the area were assumed to contain * zeros when encoding data was generated */ if (unlikely(block >= v->fec->hash_blocks)) continue; block += v->hash_start; bufio = v->bufio; } bbuf = dm_bufio_read(bufio, block, &buf); if (IS_ERR(bbuf)) { DMWARN_LIMIT("%s: FEC %llu: read failed (%llu): %ld", v->data_dev->name, (unsigned long long)rsb, (unsigned long long)block, PTR_ERR(bbuf)); /* assume the block is corrupted */ if (neras && *neras <= v->fec->roots) fio->erasures[(*neras)++] = i; continue; } /* locate erasures if the block is on the data device */ if (bufio == v->fec->data_bufio && verity_hash_for_block(v, io, block, want_digest, &is_zero) == 0) { /* skip known zero blocks entirely */ if (is_zero) goto done; /* * skip if we have already found the theoretical * maximum number (i.e. fec->roots) of erasures */ if (neras && *neras <= v->fec->roots && fec_is_erasure(v, io, want_digest, bbuf)) fio->erasures[(*neras)++] = i; } /* * deinterleave and copy the bytes that fit into bufs, * starting from block_offset */ fec_for_each_buffer_rs_block(fio, n, j) { k = fec_buffer_rs_index(n, j) + block_offset; if (k >= 1 << v->data_dev_block_bits) goto done; rs_block = fec_buffer_rs_block(v, fio, n, j); rs_block[i] = bbuf[k]; } done: dm_bufio_release(buf); } return target_index; } /* * Allocate RS control structure and FEC buffers from preallocated mempools, * and attempt to allocate as many extra buffers as available. */ static int fec_alloc_bufs(struct dm_verity *v, struct dm_verity_fec_io *fio) { unsigned int n; if (!fio->rs) fio->rs = mempool_alloc(&v->fec->rs_pool, GFP_NOIO); fec_for_each_prealloc_buffer(n) { if (fio->bufs[n]) continue; fio->bufs[n] = mempool_alloc(&v->fec->prealloc_pool, GFP_NOWAIT); if (unlikely(!fio->bufs[n])) { DMERR("failed to allocate FEC buffer"); return -ENOMEM; } } /* try to allocate the maximum number of buffers */ fec_for_each_extra_buffer(fio, n) { if (fio->bufs[n]) continue; fio->bufs[n] = mempool_alloc(&v->fec->extra_pool, GFP_NOWAIT); /* we can manage with even one buffer if necessary */ if (unlikely(!fio->bufs[n])) break; } fio->nbufs = n; if (!fio->output) fio->output = mempool_alloc(&v->fec->output_pool, GFP_NOIO); return 0; } /* * Initialize buffers and clear erasures. fec_read_bufs() assumes buffers are * zeroed before deinterleaving. */ static void fec_init_bufs(struct dm_verity *v, struct dm_verity_fec_io *fio) { unsigned int n; fec_for_each_buffer(fio, n) memset(fio->bufs[n], 0, v->fec->rsn << DM_VERITY_FEC_BUF_RS_BITS); memset(fio->erasures, 0, sizeof(fio->erasures)); } /* * Decode all RS blocks in a single data block and return the target block * (indicated by @offset) in fio->output. If @use_erasures is non-zero, uses * hashes to locate erasures. */ static int fec_decode_rsb(struct dm_verity *v, struct dm_verity_io *io, struct dm_verity_fec_io *fio, u64 rsb, u64 offset, bool use_erasures) { int r, neras = 0; unsigned int pos; r = fec_alloc_bufs(v, fio); if (unlikely(r < 0)) return r; for (pos = 0; pos < 1 << v->data_dev_block_bits; ) { fec_init_bufs(v, fio); r = fec_read_bufs(v, io, rsb, offset, pos, use_erasures ? &neras : NULL); if (unlikely(r < 0)) return r; r = fec_decode_bufs(v, fio, rsb, r, pos, neras); if (r < 0) return r; pos += fio->nbufs << DM_VERITY_FEC_BUF_RS_BITS; } /* Always re-validate the corrected block against the expected hash */ r = verity_hash(v, verity_io_hash_req(v, io), fio->output, 1 << v->data_dev_block_bits, verity_io_real_digest(v, io)); if (unlikely(r < 0)) return r; if (memcmp(verity_io_real_digest(v, io), verity_io_want_digest(v, io), v->digest_size)) { DMERR_LIMIT("%s: FEC %llu: failed to correct (%d erasures)", v->data_dev->name, (unsigned long long)rsb, neras); return -EILSEQ; } return 0; } static int fec_bv_copy(struct dm_verity *v, struct dm_verity_io *io, u8 *data, size_t len) { struct dm_verity_fec_io *fio = fec_io(io); memcpy(data, &fio->output[fio->output_pos], len); fio->output_pos += len; return 0; } /* * Correct errors in a block. Copies corrected block to dest if non-NULL, * otherwise to a bio_vec starting from iter. */ int verity_fec_decode(struct dm_verity *v, struct dm_verity_io *io, enum verity_block_type type, sector_t block, u8 *dest, struct bvec_iter *iter) { int r; struct dm_verity_fec_io *fio = fec_io(io); u64 offset, res, rsb; if (!verity_fec_is_enabled(v)) return -EOPNOTSUPP; if (fio->level >= DM_VERITY_FEC_MAX_RECURSION) { DMWARN_LIMIT("%s: FEC: recursion too deep", v->data_dev->name); return -EIO; } fio->level++; if (type == DM_VERITY_BLOCK_TYPE_METADATA) block = block - v->hash_start + v->data_blocks; /* * For RS(M, N), the continuous FEC data is divided into blocks of N * bytes. Since block size may not be divisible by N, the last block * is zero padded when decoding. * * Each byte of the block is covered by a different RS(M, N) code, * and each code is interleaved over N blocks to make it less likely * that bursty corruption will leave us in unrecoverable state. */ offset = block << v->data_dev_block_bits; res = div64_u64(offset, v->fec->rounds << v->data_dev_block_bits); /* * The base RS block we can feed to the interleaver to find out all * blocks required for decoding. */ rsb = offset - res * (v->fec->rounds << v->data_dev_block_bits); /* * Locating erasures is slow, so attempt to recover the block without * them first. Do a second attempt with erasures if the corruption is * bad enough. */ r = fec_decode_rsb(v, io, fio, rsb, offset, false); if (r < 0) { r = fec_decode_rsb(v, io, fio, rsb, offset, true); if (r < 0) goto done; } if (dest) memcpy(dest, fio->output, 1 << v->data_dev_block_bits); else if (iter) { fio->output_pos = 0; r = verity_for_bv_block(v, io, iter, fec_bv_copy); } done: fio->level--; return r; } /* * Clean up per-bio data. */ void verity_fec_finish_io(struct dm_verity_io *io) { unsigned int n; struct dm_verity_fec *f = io->v->fec; struct dm_verity_fec_io *fio = fec_io(io); if (!verity_fec_is_enabled(io->v)) return; mempool_free(fio->rs, &f->rs_pool); fec_for_each_prealloc_buffer(n) mempool_free(fio->bufs[n], &f->prealloc_pool); fec_for_each_extra_buffer(fio, n) mempool_free(fio->bufs[n], &f->extra_pool); mempool_free(fio->output, &f->output_pool); } /* * Initialize per-bio data. */ void verity_fec_init_io(struct dm_verity_io *io) { struct dm_verity_fec_io *fio = fec_io(io); if (!verity_fec_is_enabled(io->v)) return; fio->rs = NULL; memset(fio->bufs, 0, sizeof(fio->bufs)); fio->nbufs = 0; fio->output = NULL; fio->level = 0; } /* * Append feature arguments and values to the status table. */ unsigned int verity_fec_status_table(struct dm_verity *v, unsigned int sz, char *result, unsigned int maxlen) { if (!verity_fec_is_enabled(v)) return sz; DMEMIT(" " DM_VERITY_OPT_FEC_DEV " %s " DM_VERITY_OPT_FEC_BLOCKS " %llu " DM_VERITY_OPT_FEC_START " %llu " DM_VERITY_OPT_FEC_ROOTS " %d", v->fec->dev->name, (unsigned long long)v->fec->blocks, (unsigned long long)v->fec->start, v->fec->roots); return sz; } void verity_fec_dtr(struct dm_verity *v) { struct dm_verity_fec *f = v->fec; if (!verity_fec_is_enabled(v)) goto out; mempool_exit(&f->rs_pool); mempool_exit(&f->prealloc_pool); mempool_exit(&f->extra_pool); mempool_exit(&f->output_pool); kmem_cache_destroy(f->cache); if (f->data_bufio) dm_bufio_client_destroy(f->data_bufio); if (f->bufio) dm_bufio_client_destroy(f->bufio); if (f->dev) dm_put_device(v->ti, f->dev); out: kfree(f); v->fec = NULL; } static void *fec_rs_alloc(gfp_t gfp_mask, void *pool_data) { struct dm_verity *v = (struct dm_verity *)pool_data; return init_rs_gfp(8, 0x11d, 0, 1, v->fec->roots, gfp_mask); } static void fec_rs_free(void *element, void *pool_data) { struct rs_control *rs = (struct rs_control *)element; if (rs) free_rs(rs); } bool verity_is_fec_opt_arg(const char *arg_name) { return (!strcasecmp(arg_name, DM_VERITY_OPT_FEC_DEV) || !strcasecmp(arg_name, DM_VERITY_OPT_FEC_BLOCKS) || !strcasecmp(arg_name, DM_VERITY_OPT_FEC_START) || !strcasecmp(arg_name, DM_VERITY_OPT_FEC_ROOTS)); } int verity_fec_parse_opt_args(struct dm_arg_set *as, struct dm_verity *v, unsigned int *argc, const char *arg_name) { int r; struct dm_target *ti = v->ti; const char *arg_value; unsigned long long num_ll; unsigned char num_c; char dummy; if (!*argc) { ti->error = "FEC feature arguments require a value"; return -EINVAL; } arg_value = dm_shift_arg(as); (*argc)--; if (!strcasecmp(arg_name, DM_VERITY_OPT_FEC_DEV)) { r = dm_get_device(ti, arg_value, FMODE_READ, &v->fec->dev); if (r) { ti->error = "FEC device lookup failed"; return r; } } else if (!strcasecmp(arg_name, DM_VERITY_OPT_FEC_BLOCKS)) { if (sscanf(arg_value, "%llu%c", &num_ll, &dummy) != 1 || ((sector_t)(num_ll << (v->data_dev_block_bits - SECTOR_SHIFT)) >> (v->data_dev_block_bits - SECTOR_SHIFT) != num_ll)) { ti->error = "Invalid " DM_VERITY_OPT_FEC_BLOCKS; return -EINVAL; } v->fec->blocks = num_ll; } else if (!strcasecmp(arg_name, DM_VERITY_OPT_FEC_START)) { if (sscanf(arg_value, "%llu%c", &num_ll, &dummy) != 1 || ((sector_t)(num_ll << (v->data_dev_block_bits - SECTOR_SHIFT)) >> (v->data_dev_block_bits - SECTOR_SHIFT) != num_ll)) { ti->error = "Invalid " DM_VERITY_OPT_FEC_START; return -EINVAL; } v->fec->start = num_ll; } else if (!strcasecmp(arg_name, DM_VERITY_OPT_FEC_ROOTS)) { if (sscanf(arg_value, "%hhu%c", &num_c, &dummy) != 1 || !num_c || num_c < (DM_VERITY_FEC_RSM - DM_VERITY_FEC_MAX_RSN) || num_c > (DM_VERITY_FEC_RSM - DM_VERITY_FEC_MIN_RSN)) { ti->error = "Invalid " DM_VERITY_OPT_FEC_ROOTS; return -EINVAL; } v->fec->roots = num_c; } else { ti->error = "Unrecognized verity FEC feature request"; return -EINVAL; } return 0; } /* * Allocate dm_verity_fec for v->fec. Must be called before verity_fec_ctr. */ int verity_fec_ctr_alloc(struct dm_verity *v) { struct dm_verity_fec *f; f = kzalloc(sizeof(struct dm_verity_fec), GFP_KERNEL); if (!f) { v->ti->error = "Cannot allocate FEC structure"; return -ENOMEM; } v->fec = f; return 0; } /* * Validate arguments and preallocate memory. Must be called after arguments * have been parsed using verity_fec_parse_opt_args. */ int verity_fec_ctr(struct dm_verity *v) { struct dm_verity_fec *f = v->fec; struct dm_target *ti = v->ti; u64 hash_blocks, fec_blocks; int ret; if (!verity_fec_is_enabled(v)) { verity_fec_dtr(v); return 0; } /* * FEC is computed over data blocks, possible metadata, and * hash blocks. In other words, FEC covers total of fec_blocks * blocks consisting of the following: * * data blocks | hash blocks | metadata (optional) * * We allow metadata after hash blocks to support a use case * where all data is stored on the same device and FEC covers * the entire area. * * If metadata is included, we require it to be available on the * hash device after the hash blocks. */ hash_blocks = v->hash_blocks - v->hash_start; /* * Require matching block sizes for data and hash devices for * simplicity. */ if (v->data_dev_block_bits != v->hash_dev_block_bits) { ti->error = "Block sizes must match to use FEC"; return -EINVAL; } if (!f->roots) { ti->error = "Missing " DM_VERITY_OPT_FEC_ROOTS; return -EINVAL; } f->rsn = DM_VERITY_FEC_RSM - f->roots; if (!f->blocks) { ti->error = "Missing " DM_VERITY_OPT_FEC_BLOCKS; return -EINVAL; } f->rounds = f->blocks; if (sector_div(f->rounds, f->rsn)) f->rounds++; /* * Due to optional metadata, f->blocks can be larger than * data_blocks and hash_blocks combined. */ if (f->blocks < v->data_blocks + hash_blocks || !f->rounds) { ti->error = "Invalid " DM_VERITY_OPT_FEC_BLOCKS; return -EINVAL; } /* * Metadata is accessed through the hash device, so we require * it to be large enough. */ f->hash_blocks = f->blocks - v->data_blocks; if (dm_bufio_get_device_size(v->bufio) < f->hash_blocks) { ti->error = "Hash device is too small for " DM_VERITY_OPT_FEC_BLOCKS; return -E2BIG; } if ((f->roots << SECTOR_SHIFT) & ((1 << v->data_dev_block_bits) - 1)) f->io_size = 1 << v->data_dev_block_bits; else f->io_size = v->fec->roots << SECTOR_SHIFT; f->bufio = dm_bufio_client_create(f->dev->bdev, f->io_size, 1, 0, NULL, NULL, 0); if (IS_ERR(f->bufio)) { ti->error = "Cannot initialize FEC bufio client"; return PTR_ERR(f->bufio); } dm_bufio_set_sector_offset(f->bufio, f->start << (v->data_dev_block_bits - SECTOR_SHIFT)); fec_blocks = div64_u64(f->rounds * f->roots, v->fec->roots << SECTOR_SHIFT); if (dm_bufio_get_device_size(f->bufio) < fec_blocks) { ti->error = "FEC device is too small"; return -E2BIG; } f->data_bufio = dm_bufio_client_create(v->data_dev->bdev, 1 << v->data_dev_block_bits, 1, 0, NULL, NULL, 0); if (IS_ERR(f->data_bufio)) { ti->error = "Cannot initialize FEC data bufio client"; return PTR_ERR(f->data_bufio); } if (dm_bufio_get_device_size(f->data_bufio) < v->data_blocks) { ti->error = "Data device is too small"; return -E2BIG; } /* Preallocate an rs_control structure for each worker thread */ ret = mempool_init(&f->rs_pool, num_online_cpus(), fec_rs_alloc, fec_rs_free, (void *) v); if (ret) { ti->error = "Cannot allocate RS pool"; return ret; } f->cache = kmem_cache_create("dm_verity_fec_buffers", f->rsn << DM_VERITY_FEC_BUF_RS_BITS, 0, 0, NULL); if (!f->cache) { ti->error = "Cannot create FEC buffer cache"; return -ENOMEM; } /* Preallocate DM_VERITY_FEC_BUF_PREALLOC buffers for each thread */ ret = mempool_init_slab_pool(&f->prealloc_pool, num_online_cpus() * DM_VERITY_FEC_BUF_PREALLOC, f->cache); if (ret) { ti->error = "Cannot allocate FEC buffer prealloc pool"; return ret; } ret = mempool_init_slab_pool(&f->extra_pool, 0, f->cache); if (ret) { ti->error = "Cannot allocate FEC buffer extra pool"; return ret; } /* Preallocate an output buffer for each thread */ ret = mempool_init_kmalloc_pool(&f->output_pool, num_online_cpus(), 1 << v->data_dev_block_bits); if (ret) { ti->error = "Cannot allocate FEC output pool"; return ret; } /* Reserve space for our per-bio data */ ti->per_io_data_size += sizeof(struct dm_verity_fec_io); return 0; } |