1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2018-2019 HUAWEI, Inc. 4 * https://www.huawei.com/ 5 */ 6 #include "internal.h" 7 #include <linux/unaligned.h> 8 #include <trace/events/erofs.h> 9 10 struct z_erofs_maprecorder { 11 struct inode *inode; 12 struct erofs_map_blocks *map; 13 unsigned long lcn; 14 /* compression extent information gathered */ 15 u8 type, headtype; 16 u16 clusterofs; 17 u16 delta[2]; 18 erofs_blk_t pblk, compressedblks; 19 erofs_off_t nextpackoff; 20 bool partialref; 21 }; 22 23 static int z_erofs_load_full_lcluster(struct z_erofs_maprecorder *m, 24 unsigned long lcn) 25 { 26 struct inode *const inode = m->inode; 27 struct erofs_inode *const vi = EROFS_I(inode); 28 const erofs_off_t pos = Z_EROFS_FULL_INDEX_ALIGN(erofs_iloc(inode) + 29 vi->inode_isize + vi->xattr_isize) + 30 lcn * sizeof(struct z_erofs_lcluster_index); 31 struct z_erofs_lcluster_index *di; 32 unsigned int advise; 33 34 di = erofs_read_metabuf(&m->map->buf, inode->i_sb, pos, EROFS_KMAP); 35 if (IS_ERR(di)) 36 return PTR_ERR(di); 37 m->lcn = lcn; 38 m->nextpackoff = pos + sizeof(struct z_erofs_lcluster_index); 39 40 advise = le16_to_cpu(di->di_advise); 41 m->type = advise & Z_EROFS_LI_LCLUSTER_TYPE_MASK; 42 if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) { 43 m->clusterofs = 1 << vi->z_logical_clusterbits; 44 m->delta[0] = le16_to_cpu(di->di_u.delta[0]); 45 if (m->delta[0] & Z_EROFS_LI_D0_CBLKCNT) { 46 if (!(vi->z_advise & (Z_EROFS_ADVISE_BIG_PCLUSTER_1 | 47 Z_EROFS_ADVISE_BIG_PCLUSTER_2))) { 48 DBG_BUGON(1); 49 return -EFSCORRUPTED; 50 } 51 m->compressedblks = m->delta[0] & ~Z_EROFS_LI_D0_CBLKCNT; 52 m->delta[0] = 1; 53 } 54 m->delta[1] = le16_to_cpu(di->di_u.delta[1]); 55 } else { 56 m->partialref = !!(advise & Z_EROFS_LI_PARTIAL_REF); 57 m->clusterofs = le16_to_cpu(di->di_clusterofs); 58 if (m->clusterofs >= 1 << vi->z_logical_clusterbits) { 59 DBG_BUGON(1); 60 return -EFSCORRUPTED; 61 } 62 m->pblk = le32_to_cpu(di->di_u.blkaddr); 63 } 64 return 0; 65 } 66 67 static unsigned int decode_compactedbits(unsigned int lobits, 68 u8 *in, unsigned int pos, u8 *type) 69 { 70 const unsigned int v = get_unaligned_le32(in + pos / 8) >> (pos & 7); 71 const unsigned int lo = v & ((1 << lobits) - 1); 72 73 *type = (v >> lobits) & 3; 74 return lo; 75 } 76 77 static int get_compacted_la_distance(unsigned int lobits, 78 unsigned int encodebits, 79 unsigned int vcnt, u8 *in, int i) 80 { 81 unsigned int lo, d1 = 0; 82 u8 type; 83 84 DBG_BUGON(i >= vcnt); 85 86 do { 87 lo = decode_compactedbits(lobits, in, encodebits * i, &type); 88 89 if (type != Z_EROFS_LCLUSTER_TYPE_NONHEAD) 90 return d1; 91 ++d1; 92 } while (++i < vcnt); 93 94 /* vcnt - 1 (Z_EROFS_LCLUSTER_TYPE_NONHEAD) item */ 95 if (!(lo & Z_EROFS_LI_D0_CBLKCNT)) 96 d1 += lo - 1; 97 return d1; 98 } 99 100 static int unpack_compacted_index(struct z_erofs_maprecorder *m, 101 unsigned int amortizedshift, 102 erofs_off_t pos, bool lookahead) 103 { 104 struct erofs_inode *const vi = EROFS_I(m->inode); 105 const unsigned int lclusterbits = vi->z_logical_clusterbits; 106 unsigned int vcnt, lo, lobits, encodebits, nblk, bytes; 107 bool big_pcluster; 108 u8 *in, type; 109 int i; 110 111 if (1 << amortizedshift == 4 && lclusterbits <= 14) 112 vcnt = 2; 113 else if (1 << amortizedshift == 2 && lclusterbits <= 12) 114 vcnt = 16; 115 else 116 return -EOPNOTSUPP; 117 118 in = erofs_read_metabuf(&m->map->buf, m->inode->i_sb, pos, EROFS_KMAP); 119 if (IS_ERR(in)) 120 return PTR_ERR(in); 121 122 /* it doesn't equal to round_up(..) */ 123 m->nextpackoff = round_down(pos, vcnt << amortizedshift) + 124 (vcnt << amortizedshift); 125 big_pcluster = vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1; 126 lobits = max(lclusterbits, ilog2(Z_EROFS_LI_D0_CBLKCNT) + 1U); 127 encodebits = ((vcnt << amortizedshift) - sizeof(__le32)) * 8 / vcnt; 128 bytes = pos & ((vcnt << amortizedshift) - 1); 129 in -= bytes; 130 i = bytes >> amortizedshift; 131 132 lo = decode_compactedbits(lobits, in, encodebits * i, &type); 133 m->type = type; 134 if (type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) { 135 m->clusterofs = 1 << lclusterbits; 136 137 /* figure out lookahead_distance: delta[1] if needed */ 138 if (lookahead) 139 m->delta[1] = get_compacted_la_distance(lobits, 140 encodebits, vcnt, in, i); 141 if (lo & Z_EROFS_LI_D0_CBLKCNT) { 142 if (!big_pcluster) { 143 DBG_BUGON(1); 144 return -EFSCORRUPTED; 145 } 146 m->compressedblks = lo & ~Z_EROFS_LI_D0_CBLKCNT; 147 m->delta[0] = 1; 148 return 0; 149 } else if (i + 1 != (int)vcnt) { 150 m->delta[0] = lo; 151 return 0; 152 } 153 /* 154 * since the last lcluster in the pack is special, 155 * of which lo saves delta[1] rather than delta[0]. 156 * Hence, get delta[0] by the previous lcluster indirectly. 157 */ 158 lo = decode_compactedbits(lobits, in, 159 encodebits * (i - 1), &type); 160 if (type != Z_EROFS_LCLUSTER_TYPE_NONHEAD) 161 lo = 0; 162 else if (lo & Z_EROFS_LI_D0_CBLKCNT) 163 lo = 1; 164 m->delta[0] = lo + 1; 165 return 0; 166 } 167 m->clusterofs = lo; 168 m->delta[0] = 0; 169 /* figout out blkaddr (pblk) for HEAD lclusters */ 170 if (!big_pcluster) { 171 nblk = 1; 172 while (i > 0) { 173 --i; 174 lo = decode_compactedbits(lobits, in, 175 encodebits * i, &type); 176 if (type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) 177 i -= lo; 178 179 if (i >= 0) 180 ++nblk; 181 } 182 } else { 183 nblk = 0; 184 while (i > 0) { 185 --i; 186 lo = decode_compactedbits(lobits, in, 187 encodebits * i, &type); 188 if (type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) { 189 if (lo & Z_EROFS_LI_D0_CBLKCNT) { 190 --i; 191 nblk += lo & ~Z_EROFS_LI_D0_CBLKCNT; 192 continue; 193 } 194 /* bigpcluster shouldn't have plain d0 == 1 */ 195 if (lo <= 1) { 196 DBG_BUGON(1); 197 return -EFSCORRUPTED; 198 } 199 i -= lo - 2; 200 continue; 201 } 202 ++nblk; 203 } 204 } 205 in += (vcnt << amortizedshift) - sizeof(__le32); 206 m->pblk = le32_to_cpu(*(__le32 *)in) + nblk; 207 return 0; 208 } 209 210 static int z_erofs_load_compact_lcluster(struct z_erofs_maprecorder *m, 211 unsigned long lcn, bool lookahead) 212 { 213 struct inode *const inode = m->inode; 214 struct erofs_inode *const vi = EROFS_I(inode); 215 const erofs_off_t ebase = sizeof(struct z_erofs_map_header) + 216 ALIGN(erofs_iloc(inode) + vi->inode_isize + vi->xattr_isize, 8); 217 unsigned int totalidx = erofs_iblks(inode); 218 unsigned int compacted_4b_initial, compacted_2b; 219 unsigned int amortizedshift; 220 erofs_off_t pos; 221 222 if (lcn >= totalidx || vi->z_logical_clusterbits > 14) 223 return -EINVAL; 224 225 m->lcn = lcn; 226 /* used to align to 32-byte (compacted_2b) alignment */ 227 compacted_4b_initial = (32 - ebase % 32) / 4; 228 if (compacted_4b_initial == 32 / 4) 229 compacted_4b_initial = 0; 230 231 if ((vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B) && 232 compacted_4b_initial < totalidx) 233 compacted_2b = rounddown(totalidx - compacted_4b_initial, 16); 234 else 235 compacted_2b = 0; 236 237 pos = ebase; 238 if (lcn < compacted_4b_initial) { 239 amortizedshift = 2; 240 goto out; 241 } 242 pos += compacted_4b_initial * 4; 243 lcn -= compacted_4b_initial; 244 245 if (lcn < compacted_2b) { 246 amortizedshift = 1; 247 goto out; 248 } 249 pos += compacted_2b * 2; 250 lcn -= compacted_2b; 251 amortizedshift = 2; 252 out: 253 pos += lcn * (1 << amortizedshift); 254 return unpack_compacted_index(m, amortizedshift, pos, lookahead); 255 } 256 257 static int z_erofs_load_lcluster_from_disk(struct z_erofs_maprecorder *m, 258 unsigned int lcn, bool lookahead) 259 { 260 switch (EROFS_I(m->inode)->datalayout) { 261 case EROFS_INODE_COMPRESSED_FULL: 262 return z_erofs_load_full_lcluster(m, lcn); 263 case EROFS_INODE_COMPRESSED_COMPACT: 264 return z_erofs_load_compact_lcluster(m, lcn, lookahead); 265 default: 266 return -EINVAL; 267 } 268 } 269 270 static int z_erofs_extent_lookback(struct z_erofs_maprecorder *m, 271 unsigned int lookback_distance) 272 { 273 struct super_block *sb = m->inode->i_sb; 274 struct erofs_inode *const vi = EROFS_I(m->inode); 275 const unsigned int lclusterbits = vi->z_logical_clusterbits; 276 277 while (m->lcn >= lookback_distance) { 278 unsigned long lcn = m->lcn - lookback_distance; 279 int err; 280 281 err = z_erofs_load_lcluster_from_disk(m, lcn, false); 282 if (err) 283 return err; 284 285 switch (m->type) { 286 case Z_EROFS_LCLUSTER_TYPE_NONHEAD: 287 lookback_distance = m->delta[0]; 288 if (!lookback_distance) 289 goto err_bogus; 290 continue; 291 case Z_EROFS_LCLUSTER_TYPE_PLAIN: 292 case Z_EROFS_LCLUSTER_TYPE_HEAD1: 293 case Z_EROFS_LCLUSTER_TYPE_HEAD2: 294 m->headtype = m->type; 295 m->map->m_la = (lcn << lclusterbits) | m->clusterofs; 296 return 0; 297 default: 298 erofs_err(sb, "unknown type %u @ lcn %lu of nid %llu", 299 m->type, lcn, vi->nid); 300 DBG_BUGON(1); 301 return -EOPNOTSUPP; 302 } 303 } 304 err_bogus: 305 erofs_err(sb, "bogus lookback distance %u @ lcn %lu of nid %llu", 306 lookback_distance, m->lcn, vi->nid); 307 DBG_BUGON(1); 308 return -EFSCORRUPTED; 309 } 310 311 static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m, 312 unsigned int initial_lcn) 313 { 314 struct super_block *sb = m->inode->i_sb; 315 struct erofs_inode *const vi = EROFS_I(m->inode); 316 struct erofs_map_blocks *const map = m->map; 317 const unsigned int lclusterbits = vi->z_logical_clusterbits; 318 unsigned long lcn; 319 int err; 320 321 DBG_BUGON(m->type != Z_EROFS_LCLUSTER_TYPE_PLAIN && 322 m->type != Z_EROFS_LCLUSTER_TYPE_HEAD1 && 323 m->type != Z_EROFS_LCLUSTER_TYPE_HEAD2); 324 DBG_BUGON(m->type != m->headtype); 325 326 if (m->headtype == Z_EROFS_LCLUSTER_TYPE_PLAIN || 327 ((m->headtype == Z_EROFS_LCLUSTER_TYPE_HEAD1) && 328 !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1)) || 329 ((m->headtype == Z_EROFS_LCLUSTER_TYPE_HEAD2) && 330 !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_2))) { 331 map->m_plen = 1ULL << lclusterbits; 332 return 0; 333 } 334 lcn = m->lcn + 1; 335 if (m->compressedblks) 336 goto out; 337 338 err = z_erofs_load_lcluster_from_disk(m, lcn, false); 339 if (err) 340 return err; 341 342 /* 343 * If the 1st NONHEAD lcluster has already been handled initially w/o 344 * valid compressedblks, which means at least it mustn't be CBLKCNT, or 345 * an internal implemenatation error is detected. 346 * 347 * The following code can also handle it properly anyway, but let's 348 * BUG_ON in the debugging mode only for developers to notice that. 349 */ 350 DBG_BUGON(lcn == initial_lcn && 351 m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD); 352 353 switch (m->type) { 354 case Z_EROFS_LCLUSTER_TYPE_PLAIN: 355 case Z_EROFS_LCLUSTER_TYPE_HEAD1: 356 case Z_EROFS_LCLUSTER_TYPE_HEAD2: 357 /* 358 * if the 1st NONHEAD lcluster is actually PLAIN or HEAD type 359 * rather than CBLKCNT, it's a 1 lcluster-sized pcluster. 360 */ 361 m->compressedblks = 1 << (lclusterbits - sb->s_blocksize_bits); 362 break; 363 case Z_EROFS_LCLUSTER_TYPE_NONHEAD: 364 if (m->delta[0] != 1) 365 goto err_bonus_cblkcnt; 366 if (m->compressedblks) 367 break; 368 fallthrough; 369 default: 370 erofs_err(sb, "cannot found CBLKCNT @ lcn %lu of nid %llu", lcn, 371 vi->nid); 372 DBG_BUGON(1); 373 return -EFSCORRUPTED; 374 } 375 out: 376 map->m_plen = erofs_pos(sb, m->compressedblks); 377 return 0; 378 err_bonus_cblkcnt: 379 erofs_err(sb, "bogus CBLKCNT @ lcn %lu of nid %llu", lcn, vi->nid); 380 DBG_BUGON(1); 381 return -EFSCORRUPTED; 382 } 383 384 static int z_erofs_get_extent_decompressedlen(struct z_erofs_maprecorder *m) 385 { 386 struct inode *inode = m->inode; 387 struct erofs_inode *vi = EROFS_I(inode); 388 struct erofs_map_blocks *map = m->map; 389 unsigned int lclusterbits = vi->z_logical_clusterbits; 390 u64 lcn = m->lcn, headlcn = map->m_la >> lclusterbits; 391 int err; 392 393 while (1) { 394 /* handle the last EOF pcluster (no next HEAD lcluster) */ 395 if ((lcn << lclusterbits) >= inode->i_size) { 396 map->m_llen = inode->i_size - map->m_la; 397 return 0; 398 } 399 400 err = z_erofs_load_lcluster_from_disk(m, lcn, true); 401 if (err) 402 return err; 403 404 if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) { 405 /* work around invalid d1 generated by pre-1.0 mkfs */ 406 if (unlikely(!m->delta[1])) { 407 m->delta[1] = 1; 408 DBG_BUGON(1); 409 } 410 } else if (m->type == Z_EROFS_LCLUSTER_TYPE_PLAIN || 411 m->type == Z_EROFS_LCLUSTER_TYPE_HEAD1 || 412 m->type == Z_EROFS_LCLUSTER_TYPE_HEAD2) { 413 if (lcn != headlcn) 414 break; /* ends at the next HEAD lcluster */ 415 m->delta[1] = 1; 416 } else { 417 erofs_err(inode->i_sb, "unknown type %u @ lcn %llu of nid %llu", 418 m->type, lcn, vi->nid); 419 DBG_BUGON(1); 420 return -EOPNOTSUPP; 421 } 422 lcn += m->delta[1]; 423 } 424 map->m_llen = (lcn << lclusterbits) + m->clusterofs - map->m_la; 425 return 0; 426 } 427 428 static int z_erofs_do_map_blocks(struct inode *inode, 429 struct erofs_map_blocks *map, int flags) 430 { 431 struct erofs_inode *const vi = EROFS_I(inode); 432 bool ztailpacking = vi->z_advise & Z_EROFS_ADVISE_INLINE_PCLUSTER; 433 bool fragment = vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER; 434 struct z_erofs_maprecorder m = { 435 .inode = inode, 436 .map = map, 437 }; 438 int err = 0; 439 unsigned int lclusterbits, endoff, afmt; 440 unsigned long initial_lcn; 441 unsigned long long ofs, end; 442 443 lclusterbits = vi->z_logical_clusterbits; 444 ofs = flags & EROFS_GET_BLOCKS_FINDTAIL ? inode->i_size - 1 : map->m_la; 445 initial_lcn = ofs >> lclusterbits; 446 endoff = ofs & ((1 << lclusterbits) - 1); 447 448 err = z_erofs_load_lcluster_from_disk(&m, initial_lcn, false); 449 if (err) 450 goto unmap_out; 451 452 if (ztailpacking && (flags & EROFS_GET_BLOCKS_FINDTAIL)) 453 vi->z_idataoff = m.nextpackoff; 454 455 map->m_flags = EROFS_MAP_MAPPED | EROFS_MAP_ENCODED; 456 end = (m.lcn + 1ULL) << lclusterbits; 457 458 switch (m.type) { 459 case Z_EROFS_LCLUSTER_TYPE_PLAIN: 460 case Z_EROFS_LCLUSTER_TYPE_HEAD1: 461 case Z_EROFS_LCLUSTER_TYPE_HEAD2: 462 if (endoff >= m.clusterofs) { 463 m.headtype = m.type; 464 map->m_la = (m.lcn << lclusterbits) | m.clusterofs; 465 /* 466 * For ztailpacking files, in order to inline data more 467 * effectively, special EOF lclusters are now supported 468 * which can have three parts at most. 469 */ 470 if (ztailpacking && end > inode->i_size) 471 end = inode->i_size; 472 break; 473 } 474 /* m.lcn should be >= 1 if endoff < m.clusterofs */ 475 if (!m.lcn) { 476 erofs_err(inode->i_sb, 477 "invalid logical cluster 0 at nid %llu", 478 vi->nid); 479 err = -EFSCORRUPTED; 480 goto unmap_out; 481 } 482 end = (m.lcn << lclusterbits) | m.clusterofs; 483 map->m_flags |= EROFS_MAP_FULL_MAPPED; 484 m.delta[0] = 1; 485 fallthrough; 486 case Z_EROFS_LCLUSTER_TYPE_NONHEAD: 487 /* get the corresponding first chunk */ 488 err = z_erofs_extent_lookback(&m, m.delta[0]); 489 if (err) 490 goto unmap_out; 491 break; 492 default: 493 erofs_err(inode->i_sb, 494 "unknown type %u @ offset %llu of nid %llu", 495 m.type, ofs, vi->nid); 496 err = -EOPNOTSUPP; 497 goto unmap_out; 498 } 499 if (m.partialref) 500 map->m_flags |= EROFS_MAP_PARTIAL_REF; 501 map->m_llen = end - map->m_la; 502 503 if (flags & EROFS_GET_BLOCKS_FINDTAIL) { 504 vi->z_tailextent_headlcn = m.lcn; 505 /* for non-compact indexes, fragmentoff is 64 bits */ 506 if (fragment && vi->datalayout == EROFS_INODE_COMPRESSED_FULL) 507 vi->z_fragmentoff |= (u64)m.pblk << 32; 508 } 509 if (ztailpacking && m.lcn == vi->z_tailextent_headlcn) { 510 map->m_flags |= EROFS_MAP_META; 511 map->m_pa = vi->z_idataoff; 512 map->m_plen = vi->z_idata_size; 513 } else if (fragment && m.lcn == vi->z_tailextent_headlcn) { 514 map->m_flags |= EROFS_MAP_FRAGMENT; 515 } else { 516 map->m_pa = erofs_pos(inode->i_sb, m.pblk); 517 err = z_erofs_get_extent_compressedlen(&m, initial_lcn); 518 if (err) 519 goto unmap_out; 520 } 521 522 if (m.headtype == Z_EROFS_LCLUSTER_TYPE_PLAIN) { 523 if (map->m_llen > map->m_plen) { 524 DBG_BUGON(1); 525 err = -EFSCORRUPTED; 526 goto unmap_out; 527 } 528 afmt = vi->z_advise & Z_EROFS_ADVISE_INTERLACED_PCLUSTER ? 529 Z_EROFS_COMPRESSION_INTERLACED : 530 Z_EROFS_COMPRESSION_SHIFTED; 531 } else { 532 afmt = m.headtype == Z_EROFS_LCLUSTER_TYPE_HEAD2 ? 533 vi->z_algorithmtype[1] : vi->z_algorithmtype[0]; 534 if (!(EROFS_I_SB(inode)->available_compr_algs & (1 << afmt))) { 535 erofs_err(inode->i_sb, "inconsistent algorithmtype %u for nid %llu", 536 afmt, vi->nid); 537 err = -EFSCORRUPTED; 538 goto unmap_out; 539 } 540 } 541 map->m_algorithmformat = afmt; 542 543 if ((flags & EROFS_GET_BLOCKS_FIEMAP) || 544 ((flags & EROFS_GET_BLOCKS_READMORE) && 545 (map->m_algorithmformat == Z_EROFS_COMPRESSION_LZMA || 546 map->m_algorithmformat == Z_EROFS_COMPRESSION_DEFLATE || 547 map->m_algorithmformat == Z_EROFS_COMPRESSION_ZSTD) && 548 map->m_llen >= i_blocksize(inode))) { 549 err = z_erofs_get_extent_decompressedlen(&m); 550 if (!err) 551 map->m_flags |= EROFS_MAP_FULL_MAPPED; 552 } 553 554 unmap_out: 555 erofs_unmap_metabuf(&m.map->buf); 556 return err; 557 } 558 559 static int z_erofs_fill_inode_lazy(struct inode *inode) 560 { 561 struct erofs_inode *const vi = EROFS_I(inode); 562 struct super_block *const sb = inode->i_sb; 563 int err, headnr; 564 erofs_off_t pos; 565 struct erofs_buf buf = __EROFS_BUF_INITIALIZER; 566 struct z_erofs_map_header *h; 567 568 if (test_bit(EROFS_I_Z_INITED_BIT, &vi->flags)) { 569 /* 570 * paired with smp_mb() at the end of the function to ensure 571 * fields will only be observed after the bit is set. 572 */ 573 smp_mb(); 574 return 0; 575 } 576 577 if (wait_on_bit_lock(&vi->flags, EROFS_I_BL_Z_BIT, TASK_KILLABLE)) 578 return -ERESTARTSYS; 579 580 err = 0; 581 if (test_bit(EROFS_I_Z_INITED_BIT, &vi->flags)) 582 goto out_unlock; 583 584 pos = ALIGN(erofs_iloc(inode) + vi->inode_isize + vi->xattr_isize, 8); 585 h = erofs_read_metabuf(&buf, sb, pos, EROFS_KMAP); 586 if (IS_ERR(h)) { 587 err = PTR_ERR(h); 588 goto out_unlock; 589 } 590 591 /* 592 * if the highest bit of the 8-byte map header is set, the whole file 593 * is stored in the packed inode. The rest bits keeps z_fragmentoff. 594 */ 595 if (h->h_clusterbits >> Z_EROFS_FRAGMENT_INODE_BIT) { 596 vi->z_advise = Z_EROFS_ADVISE_FRAGMENT_PCLUSTER; 597 vi->z_fragmentoff = le64_to_cpu(*(__le64 *)h) ^ (1ULL << 63); 598 vi->z_tailextent_headlcn = 0; 599 goto done; 600 } 601 vi->z_advise = le16_to_cpu(h->h_advise); 602 vi->z_algorithmtype[0] = h->h_algorithmtype & 15; 603 vi->z_algorithmtype[1] = h->h_algorithmtype >> 4; 604 605 headnr = 0; 606 if (vi->z_algorithmtype[0] >= Z_EROFS_COMPRESSION_MAX || 607 vi->z_algorithmtype[++headnr] >= Z_EROFS_COMPRESSION_MAX) { 608 erofs_err(sb, "unknown HEAD%u format %u for nid %llu, please upgrade kernel", 609 headnr + 1, vi->z_algorithmtype[headnr], vi->nid); 610 err = -EOPNOTSUPP; 611 goto out_put_metabuf; 612 } 613 614 vi->z_logical_clusterbits = sb->s_blocksize_bits + (h->h_clusterbits & 7); 615 if (!erofs_sb_has_big_pcluster(EROFS_SB(sb)) && 616 vi->z_advise & (Z_EROFS_ADVISE_BIG_PCLUSTER_1 | 617 Z_EROFS_ADVISE_BIG_PCLUSTER_2)) { 618 erofs_err(sb, "per-inode big pcluster without sb feature for nid %llu", 619 vi->nid); 620 err = -EFSCORRUPTED; 621 goto out_put_metabuf; 622 } 623 if (vi->datalayout == EROFS_INODE_COMPRESSED_COMPACT && 624 !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1) ^ 625 !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_2)) { 626 erofs_err(sb, "big pcluster head1/2 of compact indexes should be consistent for nid %llu", 627 vi->nid); 628 err = -EFSCORRUPTED; 629 goto out_put_metabuf; 630 } 631 632 if (vi->z_advise & Z_EROFS_ADVISE_INLINE_PCLUSTER) { 633 struct erofs_map_blocks map = { 634 .buf = __EROFS_BUF_INITIALIZER 635 }; 636 637 vi->z_idata_size = le16_to_cpu(h->h_idata_size); 638 err = z_erofs_do_map_blocks(inode, &map, 639 EROFS_GET_BLOCKS_FINDTAIL); 640 erofs_put_metabuf(&map.buf); 641 642 if (!map.m_plen || 643 erofs_blkoff(sb, map.m_pa) + map.m_plen > sb->s_blocksize) { 644 erofs_err(sb, "invalid tail-packing pclustersize %llu", 645 map.m_plen); 646 err = -EFSCORRUPTED; 647 } 648 if (err < 0) 649 goto out_put_metabuf; 650 } 651 652 if (vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER && 653 !(h->h_clusterbits >> Z_EROFS_FRAGMENT_INODE_BIT)) { 654 struct erofs_map_blocks map = { 655 .buf = __EROFS_BUF_INITIALIZER 656 }; 657 658 vi->z_fragmentoff = le32_to_cpu(h->h_fragmentoff); 659 err = z_erofs_do_map_blocks(inode, &map, 660 EROFS_GET_BLOCKS_FINDTAIL); 661 erofs_put_metabuf(&map.buf); 662 if (err < 0) 663 goto out_put_metabuf; 664 } 665 done: 666 /* paired with smp_mb() at the beginning of the function */ 667 smp_mb(); 668 set_bit(EROFS_I_Z_INITED_BIT, &vi->flags); 669 out_put_metabuf: 670 erofs_put_metabuf(&buf); 671 out_unlock: 672 clear_and_wake_up_bit(EROFS_I_BL_Z_BIT, &vi->flags); 673 return err; 674 } 675 676 int z_erofs_map_blocks_iter(struct inode *inode, struct erofs_map_blocks *map, 677 int flags) 678 { 679 struct erofs_inode *const vi = EROFS_I(inode); 680 int err = 0; 681 682 trace_erofs_map_blocks_enter(inode, map, flags); 683 if (map->m_la >= inode->i_size) { /* post-EOF unmapped extent */ 684 map->m_llen = map->m_la + 1 - inode->i_size; 685 map->m_la = inode->i_size; 686 map->m_flags = 0; 687 } else { 688 err = z_erofs_fill_inode_lazy(inode); 689 if (!err) { 690 if ((vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER) && 691 !vi->z_tailextent_headlcn) { 692 map->m_la = 0; 693 map->m_llen = inode->i_size; 694 map->m_flags = EROFS_MAP_MAPPED | 695 EROFS_MAP_FULL_MAPPED | EROFS_MAP_FRAGMENT; 696 } else { 697 err = z_erofs_do_map_blocks(inode, map, flags); 698 } 699 } 700 if (!err && (map->m_flags & EROFS_MAP_ENCODED) && 701 unlikely(map->m_plen > Z_EROFS_PCLUSTER_MAX_SIZE || 702 map->m_llen > Z_EROFS_PCLUSTER_MAX_DSIZE)) 703 err = -EOPNOTSUPP; 704 if (err) 705 map->m_llen = 0; 706 } 707 trace_erofs_map_blocks_exit(inode, map, flags, err); 708 return err; 709 } 710 711 static int z_erofs_iomap_begin_report(struct inode *inode, loff_t offset, 712 loff_t length, unsigned int flags, 713 struct iomap *iomap, struct iomap *srcmap) 714 { 715 int ret; 716 struct erofs_map_blocks map = { .m_la = offset }; 717 718 ret = z_erofs_map_blocks_iter(inode, &map, EROFS_GET_BLOCKS_FIEMAP); 719 erofs_put_metabuf(&map.buf); 720 if (ret < 0) 721 return ret; 722 723 iomap->bdev = inode->i_sb->s_bdev; 724 iomap->offset = map.m_la; 725 iomap->length = map.m_llen; 726 if (map.m_flags & EROFS_MAP_MAPPED) { 727 iomap->type = IOMAP_MAPPED; 728 iomap->addr = map.m_flags & EROFS_MAP_FRAGMENT ? 729 IOMAP_NULL_ADDR : map.m_pa; 730 } else { 731 iomap->type = IOMAP_HOLE; 732 iomap->addr = IOMAP_NULL_ADDR; 733 /* 734 * No strict rule on how to describe extents for post EOF, yet 735 * we need to do like below. Otherwise, iomap itself will get 736 * into an endless loop on post EOF. 737 * 738 * Calculate the effective offset by subtracting extent start 739 * (map.m_la) from the requested offset, and add it to length. 740 * (NB: offset >= map.m_la always) 741 */ 742 if (iomap->offset >= inode->i_size) 743 iomap->length = length + offset - map.m_la; 744 } 745 iomap->flags = 0; 746 return 0; 747 } 748 749 const struct iomap_ops z_erofs_iomap_report_ops = { 750 .iomap_begin = z_erofs_iomap_begin_report, 751 }; 752