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_START(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, true); 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_lclusterbits; 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_lclusterbits) { 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 z_erofs_load_compact_lcluster(struct z_erofs_maprecorder *m, 101 unsigned long lcn, bool lookahead) 102 { 103 struct inode *const inode = m->inode; 104 struct erofs_inode *const vi = EROFS_I(inode); 105 const erofs_off_t ebase = Z_EROFS_MAP_HEADER_END(erofs_iloc(inode) + 106 vi->inode_isize + vi->xattr_isize); 107 const unsigned int lclusterbits = vi->z_lclusterbits; 108 const unsigned int totalidx = erofs_iblks(inode); 109 unsigned int compacted_4b_initial, compacted_2b, amortizedshift; 110 unsigned int vcnt, lo, lobits, encodebits, nblk, bytes; 111 bool big_pcluster = vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1; 112 erofs_off_t pos; 113 u8 *in, type; 114 int i; 115 116 if (lcn >= totalidx || lclusterbits > 14) 117 return -EINVAL; 118 119 m->lcn = lcn; 120 /* used to align to 32-byte (compacted_2b) alignment */ 121 compacted_4b_initial = ((32 - ebase % 32) / 4) & 7; 122 compacted_2b = 0; 123 if ((vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B) && 124 compacted_4b_initial < totalidx) 125 compacted_2b = rounddown(totalidx - compacted_4b_initial, 16); 126 127 pos = ebase; 128 amortizedshift = 2; /* compact_4b */ 129 if (lcn >= compacted_4b_initial) { 130 pos += compacted_4b_initial * 4; 131 lcn -= compacted_4b_initial; 132 if (lcn < compacted_2b) { 133 amortizedshift = 1; 134 } else { 135 pos += compacted_2b * 2; 136 lcn -= compacted_2b; 137 } 138 } 139 pos += lcn * (1 << amortizedshift); 140 141 /* figure out the lcluster count in this pack */ 142 if (1 << amortizedshift == 4 && lclusterbits <= 14) 143 vcnt = 2; 144 else if (1 << amortizedshift == 2 && lclusterbits <= 12) 145 vcnt = 16; 146 else 147 return -EOPNOTSUPP; 148 149 in = erofs_read_metabuf(&m->map->buf, m->inode->i_sb, pos, true); 150 if (IS_ERR(in)) 151 return PTR_ERR(in); 152 153 /* it doesn't equal to round_up(..) */ 154 m->nextpackoff = round_down(pos, vcnt << amortizedshift) + 155 (vcnt << amortizedshift); 156 lobits = max(lclusterbits, ilog2(Z_EROFS_LI_D0_CBLKCNT) + 1U); 157 encodebits = ((vcnt << amortizedshift) - sizeof(__le32)) * 8 / vcnt; 158 bytes = pos & ((vcnt << amortizedshift) - 1); 159 in -= bytes; 160 i = bytes >> amortizedshift; 161 162 lo = decode_compactedbits(lobits, in, encodebits * i, &type); 163 m->type = type; 164 if (type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) { 165 m->clusterofs = 1 << lclusterbits; 166 167 /* figure out lookahead_distance: delta[1] if needed */ 168 if (lookahead) 169 m->delta[1] = get_compacted_la_distance(lobits, 170 encodebits, vcnt, in, i); 171 if (lo & Z_EROFS_LI_D0_CBLKCNT) { 172 if (!big_pcluster) { 173 DBG_BUGON(1); 174 return -EFSCORRUPTED; 175 } 176 m->compressedblks = lo & ~Z_EROFS_LI_D0_CBLKCNT; 177 m->delta[0] = 1; 178 return 0; 179 } else if (i + 1 != (int)vcnt) { 180 m->delta[0] = lo; 181 return 0; 182 } 183 /* 184 * since the last lcluster in the pack is special, 185 * of which lo saves delta[1] rather than delta[0]. 186 * Hence, get delta[0] by the previous lcluster indirectly. 187 */ 188 lo = decode_compactedbits(lobits, in, 189 encodebits * (i - 1), &type); 190 if (type != Z_EROFS_LCLUSTER_TYPE_NONHEAD) 191 lo = 0; 192 else if (lo & Z_EROFS_LI_D0_CBLKCNT) 193 lo = 1; 194 m->delta[0] = lo + 1; 195 return 0; 196 } 197 m->clusterofs = lo; 198 m->delta[0] = 0; 199 /* figout out blkaddr (pblk) for HEAD lclusters */ 200 if (!big_pcluster) { 201 nblk = 1; 202 while (i > 0) { 203 --i; 204 lo = decode_compactedbits(lobits, in, 205 encodebits * i, &type); 206 if (type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) 207 i -= lo; 208 209 if (i >= 0) 210 ++nblk; 211 } 212 } else { 213 nblk = 0; 214 while (i > 0) { 215 --i; 216 lo = decode_compactedbits(lobits, in, 217 encodebits * i, &type); 218 if (type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) { 219 if (lo & Z_EROFS_LI_D0_CBLKCNT) { 220 --i; 221 nblk += lo & ~Z_EROFS_LI_D0_CBLKCNT; 222 continue; 223 } 224 /* bigpcluster shouldn't have plain d0 == 1 */ 225 if (lo <= 1) { 226 DBG_BUGON(1); 227 return -EFSCORRUPTED; 228 } 229 i -= lo - 2; 230 continue; 231 } 232 ++nblk; 233 } 234 } 235 in += (vcnt << amortizedshift) - sizeof(__le32); 236 m->pblk = le32_to_cpu(*(__le32 *)in) + nblk; 237 return 0; 238 } 239 240 static int z_erofs_load_lcluster_from_disk(struct z_erofs_maprecorder *m, 241 unsigned int lcn, bool lookahead) 242 { 243 switch (EROFS_I(m->inode)->datalayout) { 244 case EROFS_INODE_COMPRESSED_FULL: 245 return z_erofs_load_full_lcluster(m, lcn); 246 case EROFS_INODE_COMPRESSED_COMPACT: 247 return z_erofs_load_compact_lcluster(m, lcn, lookahead); 248 default: 249 return -EINVAL; 250 } 251 } 252 253 static int z_erofs_extent_lookback(struct z_erofs_maprecorder *m, 254 unsigned int lookback_distance) 255 { 256 struct super_block *sb = m->inode->i_sb; 257 struct erofs_inode *const vi = EROFS_I(m->inode); 258 const unsigned int lclusterbits = vi->z_lclusterbits; 259 260 while (m->lcn >= lookback_distance) { 261 unsigned long lcn = m->lcn - lookback_distance; 262 int err; 263 264 err = z_erofs_load_lcluster_from_disk(m, lcn, false); 265 if (err) 266 return err; 267 268 if (m->type >= Z_EROFS_LCLUSTER_TYPE_MAX) { 269 erofs_err(sb, "unknown type %u @ lcn %lu of nid %llu", 270 m->type, lcn, vi->nid); 271 DBG_BUGON(1); 272 return -EOPNOTSUPP; 273 } else if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) { 274 lookback_distance = m->delta[0]; 275 if (!lookback_distance) 276 break; 277 continue; 278 } else { 279 m->headtype = m->type; 280 m->map->m_la = (lcn << lclusterbits) | m->clusterofs; 281 return 0; 282 } 283 } 284 erofs_err(sb, "bogus lookback distance %u @ lcn %lu of nid %llu", 285 lookback_distance, m->lcn, vi->nid); 286 DBG_BUGON(1); 287 return -EFSCORRUPTED; 288 } 289 290 static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m, 291 unsigned int initial_lcn) 292 { 293 struct inode *inode = m->inode; 294 struct super_block *sb = inode->i_sb; 295 struct erofs_inode *vi = EROFS_I(inode); 296 bool bigpcl1 = vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1; 297 bool bigpcl2 = vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_2; 298 unsigned long lcn = m->lcn + 1; 299 int err; 300 301 DBG_BUGON(m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD); 302 DBG_BUGON(m->type != m->headtype); 303 304 if ((m->headtype == Z_EROFS_LCLUSTER_TYPE_HEAD1 && !bigpcl1) || 305 ((m->headtype == Z_EROFS_LCLUSTER_TYPE_PLAIN || 306 m->headtype == Z_EROFS_LCLUSTER_TYPE_HEAD2) && !bigpcl2) || 307 (lcn << vi->z_lclusterbits) >= inode->i_size) 308 m->compressedblks = 1; 309 310 if (m->compressedblks) 311 goto out; 312 313 err = z_erofs_load_lcluster_from_disk(m, lcn, false); 314 if (err) 315 return err; 316 317 /* 318 * If the 1st NONHEAD lcluster has already been handled initially w/o 319 * valid compressedblks, which means at least it mustn't be CBLKCNT, or 320 * an internal implemenatation error is detected. 321 * 322 * The following code can also handle it properly anyway, but let's 323 * BUG_ON in the debugging mode only for developers to notice that. 324 */ 325 DBG_BUGON(lcn == initial_lcn && 326 m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD); 327 328 if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) { 329 if (m->delta[0] != 1) { 330 erofs_err(sb, "bogus CBLKCNT @ lcn %lu of nid %llu", lcn, vi->nid); 331 DBG_BUGON(1); 332 return -EFSCORRUPTED; 333 } 334 if (m->compressedblks) 335 goto out; 336 } else if (m->type < Z_EROFS_LCLUSTER_TYPE_MAX) { 337 /* 338 * if the 1st NONHEAD lcluster is actually PLAIN or HEAD type 339 * rather than CBLKCNT, it's a 1 block-sized pcluster. 340 */ 341 m->compressedblks = 1; 342 goto out; 343 } 344 erofs_err(sb, "cannot found CBLKCNT @ lcn %lu of nid %llu", lcn, vi->nid); 345 DBG_BUGON(1); 346 return -EFSCORRUPTED; 347 out: 348 m->map->m_plen = erofs_pos(sb, m->compressedblks); 349 return 0; 350 } 351 352 static int z_erofs_get_extent_decompressedlen(struct z_erofs_maprecorder *m) 353 { 354 struct inode *inode = m->inode; 355 struct erofs_inode *vi = EROFS_I(inode); 356 struct erofs_map_blocks *map = m->map; 357 unsigned int lclusterbits = vi->z_lclusterbits; 358 u64 lcn = m->lcn, headlcn = map->m_la >> lclusterbits; 359 int err; 360 361 while (1) { 362 /* handle the last EOF pcluster (no next HEAD lcluster) */ 363 if ((lcn << lclusterbits) >= inode->i_size) { 364 map->m_llen = inode->i_size - map->m_la; 365 return 0; 366 } 367 368 err = z_erofs_load_lcluster_from_disk(m, lcn, true); 369 if (err) 370 return err; 371 372 if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) { 373 /* work around invalid d1 generated by pre-1.0 mkfs */ 374 if (unlikely(!m->delta[1])) { 375 m->delta[1] = 1; 376 DBG_BUGON(1); 377 } 378 } else if (m->type < Z_EROFS_LCLUSTER_TYPE_MAX) { 379 if (lcn != headlcn) 380 break; /* ends at the next HEAD lcluster */ 381 m->delta[1] = 1; 382 } else { 383 erofs_err(inode->i_sb, "unknown type %u @ lcn %llu of nid %llu", 384 m->type, lcn, vi->nid); 385 DBG_BUGON(1); 386 return -EOPNOTSUPP; 387 } 388 lcn += m->delta[1]; 389 } 390 map->m_llen = (lcn << lclusterbits) + m->clusterofs - map->m_la; 391 return 0; 392 } 393 394 static int z_erofs_map_blocks_fo(struct inode *inode, 395 struct erofs_map_blocks *map, int flags) 396 { 397 struct erofs_inode *vi = EROFS_I(inode); 398 struct super_block *sb = inode->i_sb; 399 bool fragment = vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER; 400 bool ztailpacking = vi->z_idata_size; 401 unsigned int lclusterbits = vi->z_lclusterbits; 402 struct z_erofs_maprecorder m = { 403 .inode = inode, 404 .map = map, 405 }; 406 int err = 0; 407 unsigned int endoff, afmt; 408 unsigned long initial_lcn; 409 unsigned long long ofs, end; 410 411 ofs = flags & EROFS_GET_BLOCKS_FINDTAIL ? inode->i_size - 1 : map->m_la; 412 if (fragment && !(flags & EROFS_GET_BLOCKS_FINDTAIL) && 413 !vi->z_tailextent_headlcn) { 414 map->m_la = 0; 415 map->m_llen = inode->i_size; 416 map->m_flags = EROFS_MAP_MAPPED | 417 EROFS_MAP_FULL_MAPPED | EROFS_MAP_FRAGMENT; 418 return 0; 419 } 420 initial_lcn = ofs >> lclusterbits; 421 endoff = ofs & ((1 << lclusterbits) - 1); 422 423 err = z_erofs_load_lcluster_from_disk(&m, initial_lcn, false); 424 if (err) 425 goto unmap_out; 426 427 if ((flags & EROFS_GET_BLOCKS_FINDTAIL) && ztailpacking) 428 vi->z_fragmentoff = m.nextpackoff; 429 map->m_flags = EROFS_MAP_MAPPED | EROFS_MAP_ENCODED; 430 end = (m.lcn + 1ULL) << lclusterbits; 431 432 switch (m.type) { 433 case Z_EROFS_LCLUSTER_TYPE_PLAIN: 434 case Z_EROFS_LCLUSTER_TYPE_HEAD1: 435 case Z_EROFS_LCLUSTER_TYPE_HEAD2: 436 if (endoff >= m.clusterofs) { 437 m.headtype = m.type; 438 map->m_la = (m.lcn << lclusterbits) | m.clusterofs; 439 /* 440 * For ztailpacking files, in order to inline data more 441 * effectively, special EOF lclusters are now supported 442 * which can have three parts at most. 443 */ 444 if (ztailpacking && end > inode->i_size) 445 end = inode->i_size; 446 break; 447 } 448 /* m.lcn should be >= 1 if endoff < m.clusterofs */ 449 if (!m.lcn) { 450 erofs_err(sb, "invalid logical cluster 0 at nid %llu", 451 vi->nid); 452 err = -EFSCORRUPTED; 453 goto unmap_out; 454 } 455 end = (m.lcn << lclusterbits) | m.clusterofs; 456 map->m_flags |= EROFS_MAP_FULL_MAPPED; 457 m.delta[0] = 1; 458 fallthrough; 459 case Z_EROFS_LCLUSTER_TYPE_NONHEAD: 460 /* get the corresponding first chunk */ 461 err = z_erofs_extent_lookback(&m, m.delta[0]); 462 if (err) 463 goto unmap_out; 464 break; 465 default: 466 erofs_err(sb, "unknown type %u @ offset %llu of nid %llu", 467 m.type, ofs, vi->nid); 468 err = -EOPNOTSUPP; 469 goto unmap_out; 470 } 471 if (m.partialref) 472 map->m_flags |= EROFS_MAP_PARTIAL_REF; 473 map->m_llen = end - map->m_la; 474 475 if (flags & EROFS_GET_BLOCKS_FINDTAIL) { 476 vi->z_tailextent_headlcn = m.lcn; 477 /* for non-compact indexes, fragmentoff is 64 bits */ 478 if (fragment && vi->datalayout == EROFS_INODE_COMPRESSED_FULL) 479 vi->z_fragmentoff |= (u64)m.pblk << 32; 480 } 481 if (ztailpacking && m.lcn == vi->z_tailextent_headlcn) { 482 map->m_flags |= EROFS_MAP_META; 483 map->m_pa = vi->z_fragmentoff; 484 map->m_plen = vi->z_idata_size; 485 if (erofs_blkoff(sb, map->m_pa) + map->m_plen > sb->s_blocksize) { 486 erofs_err(sb, "invalid tail-packing pclustersize %llu", 487 map->m_plen); 488 err = -EFSCORRUPTED; 489 goto unmap_out; 490 } 491 } else if (fragment && m.lcn == vi->z_tailextent_headlcn) { 492 map->m_flags |= EROFS_MAP_FRAGMENT; 493 } else { 494 map->m_pa = erofs_pos(sb, m.pblk); 495 err = z_erofs_get_extent_compressedlen(&m, initial_lcn); 496 if (err) 497 goto unmap_out; 498 } 499 500 if (m.headtype == Z_EROFS_LCLUSTER_TYPE_PLAIN) { 501 if (map->m_llen > map->m_plen) { 502 DBG_BUGON(1); 503 err = -EFSCORRUPTED; 504 goto unmap_out; 505 } 506 afmt = vi->z_advise & Z_EROFS_ADVISE_INTERLACED_PCLUSTER ? 507 Z_EROFS_COMPRESSION_INTERLACED : 508 Z_EROFS_COMPRESSION_SHIFTED; 509 } else { 510 afmt = m.headtype == Z_EROFS_LCLUSTER_TYPE_HEAD2 ? 511 vi->z_algorithmtype[1] : vi->z_algorithmtype[0]; 512 if (!(EROFS_I_SB(inode)->available_compr_algs & (1 << afmt))) { 513 erofs_err(sb, "inconsistent algorithmtype %u for nid %llu", 514 afmt, vi->nid); 515 err = -EFSCORRUPTED; 516 goto unmap_out; 517 } 518 } 519 map->m_algorithmformat = afmt; 520 521 if ((flags & EROFS_GET_BLOCKS_FIEMAP) || 522 ((flags & EROFS_GET_BLOCKS_READMORE) && 523 (map->m_algorithmformat == Z_EROFS_COMPRESSION_LZMA || 524 map->m_algorithmformat == Z_EROFS_COMPRESSION_DEFLATE || 525 map->m_algorithmformat == Z_EROFS_COMPRESSION_ZSTD) && 526 map->m_llen >= i_blocksize(inode))) { 527 err = z_erofs_get_extent_decompressedlen(&m); 528 if (!err) 529 map->m_flags |= EROFS_MAP_FULL_MAPPED; 530 } 531 532 unmap_out: 533 erofs_unmap_metabuf(&m.map->buf); 534 return err; 535 } 536 537 static int z_erofs_map_blocks_ext(struct inode *inode, 538 struct erofs_map_blocks *map, int flags) 539 { 540 struct erofs_inode *vi = EROFS_I(inode); 541 struct super_block *sb = inode->i_sb; 542 bool interlaced = vi->z_advise & Z_EROFS_ADVISE_INTERLACED_PCLUSTER; 543 unsigned int recsz = z_erofs_extent_recsize(vi->z_advise); 544 erofs_off_t pos = round_up(Z_EROFS_MAP_HEADER_END(erofs_iloc(inode) + 545 vi->inode_isize + vi->xattr_isize), recsz); 546 erofs_off_t lend = inode->i_size; 547 erofs_off_t l, r, mid, pa, la, lstart; 548 struct z_erofs_extent *ext; 549 unsigned int fmt; 550 bool last; 551 552 map->m_flags = 0; 553 if (recsz <= offsetof(struct z_erofs_extent, pstart_hi)) { 554 if (recsz <= offsetof(struct z_erofs_extent, pstart_lo)) { 555 ext = erofs_read_metabuf(&map->buf, sb, pos, true); 556 if (IS_ERR(ext)) 557 return PTR_ERR(ext); 558 pa = le64_to_cpu(*(__le64 *)ext); 559 pos += sizeof(__le64); 560 lstart = 0; 561 } else { 562 lstart = map->m_la >> vi->z_lclusterbits; 563 pa = EROFS_NULL_ADDR; 564 } 565 566 for (; lstart <= map->m_la; lstart += 1 << vi->z_lclusterbits) { 567 ext = erofs_read_metabuf(&map->buf, sb, pos, true); 568 if (IS_ERR(ext)) 569 return PTR_ERR(ext); 570 map->m_plen = le32_to_cpu(ext->plen); 571 if (pa != EROFS_NULL_ADDR) { 572 map->m_pa = pa; 573 pa += map->m_plen & Z_EROFS_EXTENT_PLEN_MASK; 574 } else { 575 map->m_pa = le32_to_cpu(ext->pstart_lo); 576 } 577 pos += recsz; 578 } 579 last = (lstart >= round_up(lend, 1 << vi->z_lclusterbits)); 580 lend = min(lstart, lend); 581 lstart -= 1 << vi->z_lclusterbits; 582 } else { 583 lstart = lend; 584 for (l = 0, r = vi->z_extents; l < r; ) { 585 mid = l + (r - l) / 2; 586 ext = erofs_read_metabuf(&map->buf, sb, 587 pos + mid * recsz, true); 588 if (IS_ERR(ext)) 589 return PTR_ERR(ext); 590 591 la = le32_to_cpu(ext->lstart_lo); 592 pa = le32_to_cpu(ext->pstart_lo) | 593 (u64)le32_to_cpu(ext->pstart_hi) << 32; 594 if (recsz > offsetof(struct z_erofs_extent, lstart_hi)) 595 la |= (u64)le32_to_cpu(ext->lstart_hi) << 32; 596 597 if (la > map->m_la) { 598 r = mid; 599 lend = la; 600 } else { 601 l = mid + 1; 602 if (map->m_la == la) 603 r = min(l + 1, r); 604 lstart = la; 605 map->m_plen = le32_to_cpu(ext->plen); 606 map->m_pa = pa; 607 } 608 } 609 last = (l >= vi->z_extents); 610 } 611 612 if (lstart < lend) { 613 map->m_la = lstart; 614 if (last && (vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER)) { 615 map->m_flags |= EROFS_MAP_MAPPED | EROFS_MAP_FRAGMENT; 616 vi->z_fragmentoff = map->m_plen; 617 if (recsz >= offsetof(struct z_erofs_extent, pstart_lo)) 618 vi->z_fragmentoff |= map->m_pa << 32; 619 } else if (map->m_plen) { 620 map->m_flags |= EROFS_MAP_MAPPED | 621 EROFS_MAP_FULL_MAPPED | EROFS_MAP_ENCODED; 622 fmt = map->m_plen >> Z_EROFS_EXTENT_PLEN_FMT_BIT; 623 if (fmt) 624 map->m_algorithmformat = fmt - 1; 625 else if (interlaced && !erofs_blkoff(sb, map->m_pa)) 626 map->m_algorithmformat = 627 Z_EROFS_COMPRESSION_INTERLACED; 628 else 629 map->m_algorithmformat = 630 Z_EROFS_COMPRESSION_SHIFTED; 631 if (map->m_plen & Z_EROFS_EXTENT_PLEN_PARTIAL) 632 map->m_flags |= EROFS_MAP_PARTIAL_REF; 633 map->m_plen &= Z_EROFS_EXTENT_PLEN_MASK; 634 } 635 } 636 map->m_llen = lend - map->m_la; 637 if (!last && map->m_llen < sb->s_blocksize) { 638 erofs_err(sb, "extent too small %llu @ offset %llu of nid %llu", 639 map->m_llen, map->m_la, vi->nid); 640 DBG_BUGON(1); 641 return -EFSCORRUPTED; 642 } 643 return 0; 644 } 645 646 static int z_erofs_fill_inode_lazy(struct inode *inode) 647 { 648 struct erofs_inode *const vi = EROFS_I(inode); 649 struct super_block *const sb = inode->i_sb; 650 int err, headnr; 651 erofs_off_t pos; 652 struct erofs_buf buf = __EROFS_BUF_INITIALIZER; 653 struct z_erofs_map_header *h; 654 655 if (test_bit(EROFS_I_Z_INITED_BIT, &vi->flags)) { 656 /* 657 * paired with smp_mb() at the end of the function to ensure 658 * fields will only be observed after the bit is set. 659 */ 660 smp_mb(); 661 return 0; 662 } 663 664 if (wait_on_bit_lock(&vi->flags, EROFS_I_BL_Z_BIT, TASK_KILLABLE)) 665 return -ERESTARTSYS; 666 667 err = 0; 668 if (test_bit(EROFS_I_Z_INITED_BIT, &vi->flags)) 669 goto out_unlock; 670 671 pos = ALIGN(erofs_iloc(inode) + vi->inode_isize + vi->xattr_isize, 8); 672 h = erofs_read_metabuf(&buf, sb, pos, true); 673 if (IS_ERR(h)) { 674 err = PTR_ERR(h); 675 goto out_unlock; 676 } 677 678 /* 679 * if the highest bit of the 8-byte map header is set, the whole file 680 * is stored in the packed inode. The rest bits keeps z_fragmentoff. 681 */ 682 if (h->h_clusterbits >> Z_EROFS_FRAGMENT_INODE_BIT) { 683 vi->z_advise = Z_EROFS_ADVISE_FRAGMENT_PCLUSTER; 684 vi->z_fragmentoff = le64_to_cpu(*(__le64 *)h) ^ (1ULL << 63); 685 vi->z_tailextent_headlcn = 0; 686 goto done; 687 } 688 vi->z_advise = le16_to_cpu(h->h_advise); 689 vi->z_lclusterbits = sb->s_blocksize_bits + (h->h_clusterbits & 15); 690 if (vi->datalayout == EROFS_INODE_COMPRESSED_FULL && 691 (vi->z_advise & Z_EROFS_ADVISE_EXTENTS)) { 692 vi->z_extents = le32_to_cpu(h->h_extents_lo) | 693 ((u64)le16_to_cpu(h->h_extents_hi) << 32); 694 goto done; 695 } 696 697 vi->z_algorithmtype[0] = h->h_algorithmtype & 15; 698 vi->z_algorithmtype[1] = h->h_algorithmtype >> 4; 699 if (vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER) 700 vi->z_fragmentoff = le32_to_cpu(h->h_fragmentoff); 701 else if (vi->z_advise & Z_EROFS_ADVISE_INLINE_PCLUSTER) 702 vi->z_idata_size = le16_to_cpu(h->h_idata_size); 703 704 headnr = 0; 705 if (vi->z_algorithmtype[0] >= Z_EROFS_COMPRESSION_MAX || 706 vi->z_algorithmtype[++headnr] >= Z_EROFS_COMPRESSION_MAX) { 707 erofs_err(sb, "unknown HEAD%u format %u for nid %llu, please upgrade kernel", 708 headnr + 1, vi->z_algorithmtype[headnr], vi->nid); 709 err = -EOPNOTSUPP; 710 goto out_put_metabuf; 711 } 712 713 if (!erofs_sb_has_big_pcluster(EROFS_SB(sb)) && 714 vi->z_advise & (Z_EROFS_ADVISE_BIG_PCLUSTER_1 | 715 Z_EROFS_ADVISE_BIG_PCLUSTER_2)) { 716 erofs_err(sb, "per-inode big pcluster without sb feature for nid %llu", 717 vi->nid); 718 err = -EFSCORRUPTED; 719 goto out_put_metabuf; 720 } 721 if (vi->datalayout == EROFS_INODE_COMPRESSED_COMPACT && 722 !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1) ^ 723 !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_2)) { 724 erofs_err(sb, "big pcluster head1/2 of compact indexes should be consistent for nid %llu", 725 vi->nid); 726 err = -EFSCORRUPTED; 727 goto out_put_metabuf; 728 } 729 730 if (vi->z_idata_size || 731 (vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER)) { 732 struct erofs_map_blocks map = { 733 .buf = __EROFS_BUF_INITIALIZER 734 }; 735 736 err = z_erofs_map_blocks_fo(inode, &map, 737 EROFS_GET_BLOCKS_FINDTAIL); 738 erofs_put_metabuf(&map.buf); 739 if (err < 0) 740 goto out_put_metabuf; 741 } 742 done: 743 /* paired with smp_mb() at the beginning of the function */ 744 smp_mb(); 745 set_bit(EROFS_I_Z_INITED_BIT, &vi->flags); 746 out_put_metabuf: 747 erofs_put_metabuf(&buf); 748 out_unlock: 749 clear_and_wake_up_bit(EROFS_I_BL_Z_BIT, &vi->flags); 750 return err; 751 } 752 753 int z_erofs_map_blocks_iter(struct inode *inode, struct erofs_map_blocks *map, 754 int flags) 755 { 756 struct erofs_inode *const vi = EROFS_I(inode); 757 int err = 0; 758 759 trace_erofs_map_blocks_enter(inode, map, flags); 760 if (map->m_la >= inode->i_size) { /* post-EOF unmapped extent */ 761 map->m_llen = map->m_la + 1 - inode->i_size; 762 map->m_la = inode->i_size; 763 map->m_flags = 0; 764 } else { 765 err = z_erofs_fill_inode_lazy(inode); 766 if (!err) { 767 if (vi->datalayout == EROFS_INODE_COMPRESSED_FULL && 768 (vi->z_advise & Z_EROFS_ADVISE_EXTENTS)) 769 err = z_erofs_map_blocks_ext(inode, map, flags); 770 else 771 err = z_erofs_map_blocks_fo(inode, map, flags); 772 } 773 if (!err && (map->m_flags & EROFS_MAP_ENCODED) && 774 unlikely(map->m_plen > Z_EROFS_PCLUSTER_MAX_SIZE || 775 map->m_llen > Z_EROFS_PCLUSTER_MAX_DSIZE)) 776 err = -EOPNOTSUPP; 777 if (err) 778 map->m_llen = 0; 779 } 780 trace_erofs_map_blocks_exit(inode, map, flags, err); 781 return err; 782 } 783 784 static int z_erofs_iomap_begin_report(struct inode *inode, loff_t offset, 785 loff_t length, unsigned int flags, 786 struct iomap *iomap, struct iomap *srcmap) 787 { 788 int ret; 789 struct erofs_map_blocks map = { .m_la = offset }; 790 791 ret = z_erofs_map_blocks_iter(inode, &map, EROFS_GET_BLOCKS_FIEMAP); 792 erofs_put_metabuf(&map.buf); 793 if (ret < 0) 794 return ret; 795 796 iomap->bdev = inode->i_sb->s_bdev; 797 iomap->offset = map.m_la; 798 iomap->length = map.m_llen; 799 if (map.m_flags & EROFS_MAP_MAPPED) { 800 iomap->type = IOMAP_MAPPED; 801 iomap->addr = map.m_flags & EROFS_MAP_FRAGMENT ? 802 IOMAP_NULL_ADDR : map.m_pa; 803 } else { 804 iomap->type = IOMAP_HOLE; 805 iomap->addr = IOMAP_NULL_ADDR; 806 /* 807 * No strict rule on how to describe extents for post EOF, yet 808 * we need to do like below. Otherwise, iomap itself will get 809 * into an endless loop on post EOF. 810 * 811 * Calculate the effective offset by subtracting extent start 812 * (map.m_la) from the requested offset, and add it to length. 813 * (NB: offset >= map.m_la always) 814 */ 815 if (iomap->offset >= inode->i_size) 816 iomap->length = length + offset - map.m_la; 817 } 818 iomap->flags = 0; 819 return 0; 820 } 821 822 const struct iomap_ops z_erofs_iomap_report_ops = { 823 .iomap_begin = z_erofs_iomap_begin_report, 824 }; 825