1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd. 4 */ 5 6 #include <linux/slab.h> 7 #include <linux/bio.h> 8 #include <linux/buffer_head.h> 9 10 #include "exfat_raw.h" 11 #include "exfat_fs.h" 12 13 static int exfat_extract_uni_name(struct exfat_dentry *ep, 14 unsigned short *uniname) 15 { 16 int i, len = 0; 17 18 for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) { 19 *uniname = le16_to_cpu(ep->dentry.name.unicode_0_14[i]); 20 if (*uniname == 0x0) 21 return len; 22 uniname++; 23 len++; 24 } 25 26 *uniname = 0x0; 27 return len; 28 29 } 30 31 static void exfat_get_uniname_from_ext_entry(struct super_block *sb, 32 struct exfat_chain *p_dir, int entry, unsigned short *uniname) 33 { 34 int i; 35 struct exfat_entry_set_cache *es; 36 37 es = exfat_get_dentry_set(sb, p_dir, entry, ES_ALL_ENTRIES); 38 if (!es) 39 return; 40 41 /* 42 * First entry : file entry 43 * Second entry : stream-extension entry 44 * Third entry : first file-name entry 45 * So, the index of first file-name dentry should start from 2. 46 */ 47 for (i = 2; i < es->num_entries; i++) { 48 struct exfat_dentry *ep = exfat_get_dentry_cached(es, i); 49 50 /* end of name entry */ 51 if (exfat_get_entry_type(ep) != TYPE_EXTEND) 52 break; 53 54 exfat_extract_uni_name(ep, uniname); 55 uniname += EXFAT_FILE_NAME_LEN; 56 } 57 58 exfat_free_dentry_set(es, false); 59 } 60 61 /* read a directory entry from the opened directory */ 62 static int exfat_readdir(struct inode *inode, loff_t *cpos, struct exfat_dir_entry *dir_entry) 63 { 64 int i, dentries_per_clu, dentries_per_clu_bits = 0, num_ext; 65 unsigned int type, clu_offset; 66 sector_t sector; 67 struct exfat_chain dir, clu; 68 struct exfat_uni_name uni_name; 69 struct exfat_dentry *ep; 70 struct super_block *sb = inode->i_sb; 71 struct exfat_sb_info *sbi = EXFAT_SB(sb); 72 struct exfat_inode_info *ei = EXFAT_I(inode); 73 unsigned int dentry = EXFAT_B_TO_DEN(*cpos) & 0xFFFFFFFF; 74 struct buffer_head *bh; 75 76 /* check if the given file ID is opened */ 77 if (ei->type != TYPE_DIR) 78 return -EPERM; 79 80 if (ei->entry == -1) 81 exfat_chain_set(&dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN); 82 else 83 exfat_chain_set(&dir, ei->start_clu, 84 EXFAT_B_TO_CLU(i_size_read(inode), sbi), ei->flags); 85 86 dentries_per_clu = sbi->dentries_per_clu; 87 dentries_per_clu_bits = ilog2(dentries_per_clu); 88 89 clu_offset = dentry >> dentries_per_clu_bits; 90 exfat_chain_dup(&clu, &dir); 91 92 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 93 clu.dir += clu_offset; 94 clu.size -= clu_offset; 95 } else { 96 /* hint_information */ 97 if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER && 98 ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) { 99 clu_offset -= ei->hint_bmap.off; 100 clu.dir = ei->hint_bmap.clu; 101 } 102 103 while (clu_offset > 0) { 104 if (exfat_get_next_cluster(sb, &(clu.dir))) 105 return -EIO; 106 107 clu_offset--; 108 } 109 } 110 111 while (clu.dir != EXFAT_EOF_CLUSTER) { 112 i = dentry & (dentries_per_clu - 1); 113 114 for ( ; i < dentries_per_clu; i++, dentry++) { 115 ep = exfat_get_dentry(sb, &clu, i, &bh, §or); 116 if (!ep) 117 return -EIO; 118 119 type = exfat_get_entry_type(ep); 120 if (type == TYPE_UNUSED) { 121 brelse(bh); 122 break; 123 } 124 125 if (type != TYPE_FILE && type != TYPE_DIR) { 126 brelse(bh); 127 continue; 128 } 129 130 num_ext = ep->dentry.file.num_ext; 131 dir_entry->attr = le16_to_cpu(ep->dentry.file.attr); 132 exfat_get_entry_time(sbi, &dir_entry->crtime, 133 ep->dentry.file.create_tz, 134 ep->dentry.file.create_time, 135 ep->dentry.file.create_date, 136 ep->dentry.file.create_time_cs); 137 exfat_get_entry_time(sbi, &dir_entry->mtime, 138 ep->dentry.file.modify_tz, 139 ep->dentry.file.modify_time, 140 ep->dentry.file.modify_date, 141 ep->dentry.file.modify_time_cs); 142 exfat_get_entry_time(sbi, &dir_entry->atime, 143 ep->dentry.file.access_tz, 144 ep->dentry.file.access_time, 145 ep->dentry.file.access_date, 146 0); 147 148 *uni_name.name = 0x0; 149 exfat_get_uniname_from_ext_entry(sb, &dir, dentry, 150 uni_name.name); 151 exfat_utf16_to_nls(sb, &uni_name, 152 dir_entry->namebuf.lfn, 153 dir_entry->namebuf.lfnbuf_len); 154 brelse(bh); 155 156 ep = exfat_get_dentry(sb, &clu, i + 1, &bh, NULL); 157 if (!ep) 158 return -EIO; 159 dir_entry->size = 160 le64_to_cpu(ep->dentry.stream.valid_size); 161 dir_entry->entry = dentry; 162 brelse(bh); 163 164 ei->hint_bmap.off = dentry >> dentries_per_clu_bits; 165 ei->hint_bmap.clu = clu.dir; 166 167 *cpos = EXFAT_DEN_TO_B(dentry + 1 + num_ext); 168 return 0; 169 } 170 171 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 172 if (--clu.size > 0) 173 clu.dir++; 174 else 175 clu.dir = EXFAT_EOF_CLUSTER; 176 } else { 177 if (exfat_get_next_cluster(sb, &(clu.dir))) 178 return -EIO; 179 } 180 } 181 182 dir_entry->namebuf.lfn[0] = '\0'; 183 *cpos = EXFAT_DEN_TO_B(dentry); 184 return 0; 185 } 186 187 static void exfat_init_namebuf(struct exfat_dentry_namebuf *nb) 188 { 189 nb->lfn = NULL; 190 nb->lfnbuf_len = 0; 191 } 192 193 static int exfat_alloc_namebuf(struct exfat_dentry_namebuf *nb) 194 { 195 nb->lfn = __getname(); 196 if (!nb->lfn) 197 return -ENOMEM; 198 nb->lfnbuf_len = MAX_VFSNAME_BUF_SIZE; 199 return 0; 200 } 201 202 static void exfat_free_namebuf(struct exfat_dentry_namebuf *nb) 203 { 204 if (!nb->lfn) 205 return; 206 207 __putname(nb->lfn); 208 exfat_init_namebuf(nb); 209 } 210 211 /* skip iterating emit_dots when dir is empty */ 212 #define ITER_POS_FILLED_DOTS (2) 213 static int exfat_iterate(struct file *filp, struct dir_context *ctx) 214 { 215 struct inode *inode = filp->f_path.dentry->d_inode; 216 struct super_block *sb = inode->i_sb; 217 struct inode *tmp; 218 struct exfat_dir_entry de; 219 struct exfat_dentry_namebuf *nb = &(de.namebuf); 220 struct exfat_inode_info *ei = EXFAT_I(inode); 221 unsigned long inum; 222 loff_t cpos, i_pos; 223 int err = 0, fake_offset = 0; 224 225 exfat_init_namebuf(nb); 226 mutex_lock(&EXFAT_SB(sb)->s_lock); 227 228 cpos = ctx->pos; 229 if (!dir_emit_dots(filp, ctx)) 230 goto unlock; 231 232 if (ctx->pos == ITER_POS_FILLED_DOTS) { 233 cpos = 0; 234 fake_offset = 1; 235 } 236 237 if (cpos & (DENTRY_SIZE - 1)) { 238 err = -ENOENT; 239 goto unlock; 240 } 241 242 /* name buffer should be allocated before use */ 243 err = exfat_alloc_namebuf(nb); 244 if (err) 245 goto unlock; 246 get_new: 247 if (cpos >= i_size_read(inode)) 248 goto end_of_dir; 249 250 err = exfat_readdir(inode, &cpos, &de); 251 if (err) { 252 /* 253 * At least we tried to read a sector. Move cpos to next sector 254 * position (should be aligned). 255 */ 256 if (err == -EIO) { 257 cpos += 1 << (sb->s_blocksize_bits); 258 cpos &= ~(sb->s_blocksize - 1); 259 } 260 261 err = -EIO; 262 goto end_of_dir; 263 } 264 265 if (!nb->lfn[0]) 266 goto end_of_dir; 267 268 i_pos = ((loff_t)ei->start_clu << 32) | (de.entry & 0xffffffff); 269 tmp = exfat_iget(sb, i_pos); 270 if (tmp) { 271 inum = tmp->i_ino; 272 iput(tmp); 273 } else { 274 inum = iunique(sb, EXFAT_ROOT_INO); 275 } 276 277 /* 278 * Before calling dir_emit(), sb_lock should be released. 279 * Because page fault can occur in dir_emit() when the size 280 * of buffer given from user is larger than one page size. 281 */ 282 mutex_unlock(&EXFAT_SB(sb)->s_lock); 283 if (!dir_emit(ctx, nb->lfn, strlen(nb->lfn), inum, 284 (de.attr & ATTR_SUBDIR) ? DT_DIR : DT_REG)) 285 goto out_unlocked; 286 mutex_lock(&EXFAT_SB(sb)->s_lock); 287 ctx->pos = cpos; 288 goto get_new; 289 290 end_of_dir: 291 if (!cpos && fake_offset) 292 cpos = ITER_POS_FILLED_DOTS; 293 ctx->pos = cpos; 294 unlock: 295 mutex_unlock(&EXFAT_SB(sb)->s_lock); 296 out_unlocked: 297 /* 298 * To improve performance, free namebuf after unlock sb_lock. 299 * If namebuf is not allocated, this function do nothing 300 */ 301 exfat_free_namebuf(nb); 302 return err; 303 } 304 305 const struct file_operations exfat_dir_operations = { 306 .llseek = generic_file_llseek, 307 .read = generic_read_dir, 308 .iterate = exfat_iterate, 309 .fsync = exfat_file_fsync, 310 }; 311 312 int exfat_alloc_new_dir(struct inode *inode, struct exfat_chain *clu) 313 { 314 int ret; 315 316 exfat_chain_set(clu, EXFAT_EOF_CLUSTER, 0, ALLOC_NO_FAT_CHAIN); 317 318 ret = exfat_alloc_cluster(inode, 1, clu); 319 if (ret) 320 return ret; 321 322 return exfat_zeroed_cluster(inode, clu->dir); 323 } 324 325 int exfat_calc_num_entries(struct exfat_uni_name *p_uniname) 326 { 327 int len; 328 329 len = p_uniname->name_len; 330 if (len == 0) 331 return -EINVAL; 332 333 /* 1 file entry + 1 stream entry + name entries */ 334 return ((len - 1) / EXFAT_FILE_NAME_LEN + 3); 335 } 336 337 unsigned int exfat_get_entry_type(struct exfat_dentry *ep) 338 { 339 if (ep->type == EXFAT_UNUSED) 340 return TYPE_UNUSED; 341 if (IS_EXFAT_DELETED(ep->type)) 342 return TYPE_DELETED; 343 if (ep->type == EXFAT_INVAL) 344 return TYPE_INVALID; 345 if (IS_EXFAT_CRITICAL_PRI(ep->type)) { 346 if (ep->type == EXFAT_BITMAP) 347 return TYPE_BITMAP; 348 if (ep->type == EXFAT_UPCASE) 349 return TYPE_UPCASE; 350 if (ep->type == EXFAT_VOLUME) 351 return TYPE_VOLUME; 352 if (ep->type == EXFAT_FILE) { 353 if (le16_to_cpu(ep->dentry.file.attr) & ATTR_SUBDIR) 354 return TYPE_DIR; 355 return TYPE_FILE; 356 } 357 return TYPE_CRITICAL_PRI; 358 } 359 if (IS_EXFAT_BENIGN_PRI(ep->type)) { 360 if (ep->type == EXFAT_GUID) 361 return TYPE_GUID; 362 if (ep->type == EXFAT_PADDING) 363 return TYPE_PADDING; 364 if (ep->type == EXFAT_ACLTAB) 365 return TYPE_ACLTAB; 366 return TYPE_BENIGN_PRI; 367 } 368 if (IS_EXFAT_CRITICAL_SEC(ep->type)) { 369 if (ep->type == EXFAT_STREAM) 370 return TYPE_STREAM; 371 if (ep->type == EXFAT_NAME) 372 return TYPE_EXTEND; 373 if (ep->type == EXFAT_ACL) 374 return TYPE_ACL; 375 return TYPE_CRITICAL_SEC; 376 } 377 return TYPE_BENIGN_SEC; 378 } 379 380 static void exfat_set_entry_type(struct exfat_dentry *ep, unsigned int type) 381 { 382 if (type == TYPE_UNUSED) { 383 ep->type = EXFAT_UNUSED; 384 } else if (type == TYPE_DELETED) { 385 ep->type &= EXFAT_DELETE; 386 } else if (type == TYPE_STREAM) { 387 ep->type = EXFAT_STREAM; 388 } else if (type == TYPE_EXTEND) { 389 ep->type = EXFAT_NAME; 390 } else if (type == TYPE_BITMAP) { 391 ep->type = EXFAT_BITMAP; 392 } else if (type == TYPE_UPCASE) { 393 ep->type = EXFAT_UPCASE; 394 } else if (type == TYPE_VOLUME) { 395 ep->type = EXFAT_VOLUME; 396 } else if (type == TYPE_DIR) { 397 ep->type = EXFAT_FILE; 398 ep->dentry.file.attr = cpu_to_le16(ATTR_SUBDIR); 399 } else if (type == TYPE_FILE) { 400 ep->type = EXFAT_FILE; 401 ep->dentry.file.attr = cpu_to_le16(ATTR_ARCHIVE); 402 } 403 } 404 405 static void exfat_init_stream_entry(struct exfat_dentry *ep, 406 unsigned char flags, unsigned int start_clu, 407 unsigned long long size) 408 { 409 exfat_set_entry_type(ep, TYPE_STREAM); 410 ep->dentry.stream.flags = flags; 411 ep->dentry.stream.start_clu = cpu_to_le32(start_clu); 412 ep->dentry.stream.valid_size = cpu_to_le64(size); 413 ep->dentry.stream.size = cpu_to_le64(size); 414 } 415 416 static void exfat_init_name_entry(struct exfat_dentry *ep, 417 unsigned short *uniname) 418 { 419 int i; 420 421 exfat_set_entry_type(ep, TYPE_EXTEND); 422 ep->dentry.name.flags = 0x0; 423 424 for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) { 425 if (*uniname != 0x0) { 426 ep->dentry.name.unicode_0_14[i] = cpu_to_le16(*uniname); 427 uniname++; 428 } else { 429 ep->dentry.name.unicode_0_14[i] = 0x0; 430 } 431 } 432 } 433 434 int exfat_init_dir_entry(struct inode *inode, struct exfat_chain *p_dir, 435 int entry, unsigned int type, unsigned int start_clu, 436 unsigned long long size) 437 { 438 struct super_block *sb = inode->i_sb; 439 struct exfat_sb_info *sbi = EXFAT_SB(sb); 440 struct timespec64 ts = current_time(inode); 441 sector_t sector; 442 struct exfat_dentry *ep; 443 struct buffer_head *bh; 444 445 /* 446 * We cannot use exfat_get_dentry_set here because file ep is not 447 * initialized yet. 448 */ 449 ep = exfat_get_dentry(sb, p_dir, entry, &bh, §or); 450 if (!ep) 451 return -EIO; 452 453 exfat_set_entry_type(ep, type); 454 exfat_set_entry_time(sbi, &ts, 455 &ep->dentry.file.create_tz, 456 &ep->dentry.file.create_time, 457 &ep->dentry.file.create_date, 458 &ep->dentry.file.create_time_cs); 459 exfat_set_entry_time(sbi, &ts, 460 &ep->dentry.file.modify_tz, 461 &ep->dentry.file.modify_time, 462 &ep->dentry.file.modify_date, 463 &ep->dentry.file.modify_time_cs); 464 exfat_set_entry_time(sbi, &ts, 465 &ep->dentry.file.access_tz, 466 &ep->dentry.file.access_time, 467 &ep->dentry.file.access_date, 468 NULL); 469 470 exfat_update_bh(bh, IS_DIRSYNC(inode)); 471 brelse(bh); 472 473 ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh, §or); 474 if (!ep) 475 return -EIO; 476 477 exfat_init_stream_entry(ep, 478 (type == TYPE_FILE) ? ALLOC_FAT_CHAIN : ALLOC_NO_FAT_CHAIN, 479 start_clu, size); 480 exfat_update_bh(bh, IS_DIRSYNC(inode)); 481 brelse(bh); 482 483 return 0; 484 } 485 486 int exfat_update_dir_chksum(struct inode *inode, struct exfat_chain *p_dir, 487 int entry) 488 { 489 struct super_block *sb = inode->i_sb; 490 int ret = 0; 491 int i, num_entries; 492 sector_t sector; 493 u16 chksum; 494 struct exfat_dentry *ep, *fep; 495 struct buffer_head *fbh, *bh; 496 497 fep = exfat_get_dentry(sb, p_dir, entry, &fbh, §or); 498 if (!fep) 499 return -EIO; 500 501 num_entries = fep->dentry.file.num_ext + 1; 502 chksum = exfat_calc_chksum16(fep, DENTRY_SIZE, 0, CS_DIR_ENTRY); 503 504 for (i = 1; i < num_entries; i++) { 505 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh, NULL); 506 if (!ep) { 507 ret = -EIO; 508 goto release_fbh; 509 } 510 chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum, 511 CS_DEFAULT); 512 brelse(bh); 513 } 514 515 fep->dentry.file.checksum = cpu_to_le16(chksum); 516 exfat_update_bh(fbh, IS_DIRSYNC(inode)); 517 release_fbh: 518 brelse(fbh); 519 return ret; 520 } 521 522 int exfat_init_ext_entry(struct inode *inode, struct exfat_chain *p_dir, 523 int entry, int num_entries, struct exfat_uni_name *p_uniname) 524 { 525 struct super_block *sb = inode->i_sb; 526 int i; 527 sector_t sector; 528 unsigned short *uniname = p_uniname->name; 529 struct exfat_dentry *ep; 530 struct buffer_head *bh; 531 int sync = IS_DIRSYNC(inode); 532 533 ep = exfat_get_dentry(sb, p_dir, entry, &bh, §or); 534 if (!ep) 535 return -EIO; 536 537 ep->dentry.file.num_ext = (unsigned char)(num_entries - 1); 538 exfat_update_bh(bh, sync); 539 brelse(bh); 540 541 ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh, §or); 542 if (!ep) 543 return -EIO; 544 545 ep->dentry.stream.name_len = p_uniname->name_len; 546 ep->dentry.stream.name_hash = cpu_to_le16(p_uniname->name_hash); 547 exfat_update_bh(bh, sync); 548 brelse(bh); 549 550 for (i = EXFAT_FIRST_CLUSTER; i < num_entries; i++) { 551 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh, §or); 552 if (!ep) 553 return -EIO; 554 555 exfat_init_name_entry(ep, uniname); 556 exfat_update_bh(bh, sync); 557 brelse(bh); 558 uniname += EXFAT_FILE_NAME_LEN; 559 } 560 561 exfat_update_dir_chksum(inode, p_dir, entry); 562 return 0; 563 } 564 565 int exfat_remove_entries(struct inode *inode, struct exfat_chain *p_dir, 566 int entry, int order, int num_entries) 567 { 568 struct super_block *sb = inode->i_sb; 569 int i; 570 sector_t sector; 571 struct exfat_dentry *ep; 572 struct buffer_head *bh; 573 574 for (i = order; i < num_entries; i++) { 575 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh, §or); 576 if (!ep) 577 return -EIO; 578 579 exfat_set_entry_type(ep, TYPE_DELETED); 580 exfat_update_bh(bh, IS_DIRSYNC(inode)); 581 brelse(bh); 582 } 583 584 return 0; 585 } 586 587 void exfat_update_dir_chksum_with_entry_set(struct exfat_entry_set_cache *es) 588 { 589 int chksum_type = CS_DIR_ENTRY, i; 590 unsigned short chksum = 0; 591 struct exfat_dentry *ep; 592 593 for (i = 0; i < es->num_entries; i++) { 594 ep = exfat_get_dentry_cached(es, i); 595 chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum, 596 chksum_type); 597 chksum_type = CS_DEFAULT; 598 } 599 ep = exfat_get_dentry_cached(es, 0); 600 ep->dentry.file.checksum = cpu_to_le16(chksum); 601 es->modified = true; 602 } 603 604 int exfat_free_dentry_set(struct exfat_entry_set_cache *es, int sync) 605 { 606 int i, err = 0; 607 608 if (es->modified) 609 err = exfat_update_bhs(es->bh, es->num_bh, sync); 610 611 for (i = 0; i < es->num_bh; i++) 612 if (err) 613 bforget(es->bh[i]); 614 else 615 brelse(es->bh[i]); 616 kfree(es); 617 return err; 618 } 619 620 static int exfat_walk_fat_chain(struct super_block *sb, 621 struct exfat_chain *p_dir, unsigned int byte_offset, 622 unsigned int *clu) 623 { 624 struct exfat_sb_info *sbi = EXFAT_SB(sb); 625 unsigned int clu_offset; 626 unsigned int cur_clu; 627 628 clu_offset = EXFAT_B_TO_CLU(byte_offset, sbi); 629 cur_clu = p_dir->dir; 630 631 if (p_dir->flags == ALLOC_NO_FAT_CHAIN) { 632 cur_clu += clu_offset; 633 } else { 634 while (clu_offset > 0) { 635 if (exfat_get_next_cluster(sb, &cur_clu)) 636 return -EIO; 637 if (cur_clu == EXFAT_EOF_CLUSTER) { 638 exfat_fs_error(sb, 639 "invalid dentry access beyond EOF (clu : %u, eidx : %d)", 640 p_dir->dir, 641 EXFAT_B_TO_DEN(byte_offset)); 642 return -EIO; 643 } 644 clu_offset--; 645 } 646 } 647 648 *clu = cur_clu; 649 return 0; 650 } 651 652 int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir, 653 int entry, sector_t *sector, int *offset) 654 { 655 int ret; 656 unsigned int off, clu = 0; 657 struct exfat_sb_info *sbi = EXFAT_SB(sb); 658 659 off = EXFAT_DEN_TO_B(entry); 660 661 ret = exfat_walk_fat_chain(sb, p_dir, off, &clu); 662 if (ret) 663 return ret; 664 665 /* byte offset in cluster */ 666 off = EXFAT_CLU_OFFSET(off, sbi); 667 668 /* byte offset in sector */ 669 *offset = EXFAT_BLK_OFFSET(off, sb); 670 671 /* sector offset in cluster */ 672 *sector = EXFAT_B_TO_BLK(off, sb); 673 *sector += exfat_cluster_to_sector(sbi, clu); 674 return 0; 675 } 676 677 #define EXFAT_MAX_RA_SIZE (128*1024) 678 static int exfat_dir_readahead(struct super_block *sb, sector_t sec) 679 { 680 struct exfat_sb_info *sbi = EXFAT_SB(sb); 681 struct buffer_head *bh; 682 unsigned int max_ra_count = EXFAT_MAX_RA_SIZE >> sb->s_blocksize_bits; 683 unsigned int page_ra_count = PAGE_SIZE >> sb->s_blocksize_bits; 684 unsigned int adj_ra_count = max(sbi->sect_per_clus, page_ra_count); 685 unsigned int ra_count = min(adj_ra_count, max_ra_count); 686 687 /* Read-ahead is not required */ 688 if (sbi->sect_per_clus == 1) 689 return 0; 690 691 if (sec < sbi->data_start_sector) { 692 exfat_err(sb, "requested sector is invalid(sect:%llu, root:%llu)", 693 (unsigned long long)sec, sbi->data_start_sector); 694 return -EIO; 695 } 696 697 /* Not sector aligned with ra_count, resize ra_count to page size */ 698 if ((sec - sbi->data_start_sector) & (ra_count - 1)) 699 ra_count = page_ra_count; 700 701 bh = sb_find_get_block(sb, sec); 702 if (!bh || !buffer_uptodate(bh)) { 703 unsigned int i; 704 705 for (i = 0; i < ra_count; i++) 706 sb_breadahead(sb, (sector_t)(sec + i)); 707 } 708 brelse(bh); 709 return 0; 710 } 711 712 struct exfat_dentry *exfat_get_dentry(struct super_block *sb, 713 struct exfat_chain *p_dir, int entry, struct buffer_head **bh, 714 sector_t *sector) 715 { 716 unsigned int dentries_per_page = EXFAT_B_TO_DEN(PAGE_SIZE); 717 int off; 718 sector_t sec; 719 720 if (p_dir->dir == DIR_DELETED) { 721 exfat_err(sb, "abnormal access to deleted dentry"); 722 return NULL; 723 } 724 725 if (exfat_find_location(sb, p_dir, entry, &sec, &off)) 726 return NULL; 727 728 if (p_dir->dir != EXFAT_FREE_CLUSTER && 729 !(entry & (dentries_per_page - 1))) 730 exfat_dir_readahead(sb, sec); 731 732 *bh = sb_bread(sb, sec); 733 if (!*bh) 734 return NULL; 735 736 if (sector) 737 *sector = sec; 738 return (struct exfat_dentry *)((*bh)->b_data + off); 739 } 740 741 enum exfat_validate_dentry_mode { 742 ES_MODE_STARTED, 743 ES_MODE_GET_FILE_ENTRY, 744 ES_MODE_GET_STRM_ENTRY, 745 ES_MODE_GET_NAME_ENTRY, 746 ES_MODE_GET_CRITICAL_SEC_ENTRY, 747 }; 748 749 static bool exfat_validate_entry(unsigned int type, 750 enum exfat_validate_dentry_mode *mode) 751 { 752 if (type == TYPE_UNUSED || type == TYPE_DELETED) 753 return false; 754 755 switch (*mode) { 756 case ES_MODE_STARTED: 757 if (type != TYPE_FILE && type != TYPE_DIR) 758 return false; 759 *mode = ES_MODE_GET_FILE_ENTRY; 760 return true; 761 case ES_MODE_GET_FILE_ENTRY: 762 if (type != TYPE_STREAM) 763 return false; 764 *mode = ES_MODE_GET_STRM_ENTRY; 765 return true; 766 case ES_MODE_GET_STRM_ENTRY: 767 if (type != TYPE_EXTEND) 768 return false; 769 *mode = ES_MODE_GET_NAME_ENTRY; 770 return true; 771 case ES_MODE_GET_NAME_ENTRY: 772 if (type == TYPE_STREAM) 773 return false; 774 if (type != TYPE_EXTEND) { 775 if (!(type & TYPE_CRITICAL_SEC)) 776 return false; 777 *mode = ES_MODE_GET_CRITICAL_SEC_ENTRY; 778 } 779 return true; 780 case ES_MODE_GET_CRITICAL_SEC_ENTRY: 781 if (type == TYPE_EXTEND || type == TYPE_STREAM) 782 return false; 783 if ((type & TYPE_CRITICAL_SEC) != TYPE_CRITICAL_SEC) 784 return false; 785 return true; 786 default: 787 WARN_ON_ONCE(1); 788 return false; 789 } 790 } 791 792 struct exfat_dentry *exfat_get_dentry_cached( 793 struct exfat_entry_set_cache *es, int num) 794 { 795 int off = es->start_off + num * DENTRY_SIZE; 796 struct buffer_head *bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)]; 797 char *p = bh->b_data + EXFAT_BLK_OFFSET(off, es->sb); 798 799 return (struct exfat_dentry *)p; 800 } 801 802 /* 803 * Returns a set of dentries for a file or dir. 804 * 805 * Note It provides a direct pointer to bh->data via exfat_get_dentry_cached(). 806 * User should call exfat_get_dentry_set() after setting 'modified' to apply 807 * changes made in this entry set to the real device. 808 * 809 * in: 810 * sb+p_dir+entry: indicates a file/dir 811 * type: specifies how many dentries should be included. 812 * return: 813 * pointer of entry set on success, 814 * NULL on failure. 815 */ 816 struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb, 817 struct exfat_chain *p_dir, int entry, unsigned int type) 818 { 819 int ret, i, num_bh; 820 unsigned int off, byte_offset, clu = 0; 821 sector_t sec; 822 struct exfat_sb_info *sbi = EXFAT_SB(sb); 823 struct exfat_entry_set_cache *es; 824 struct exfat_dentry *ep; 825 int num_entries; 826 enum exfat_validate_dentry_mode mode = ES_MODE_STARTED; 827 struct buffer_head *bh; 828 829 if (p_dir->dir == DIR_DELETED) { 830 exfat_err(sb, "access to deleted dentry"); 831 return NULL; 832 } 833 834 byte_offset = EXFAT_DEN_TO_B(entry); 835 ret = exfat_walk_fat_chain(sb, p_dir, byte_offset, &clu); 836 if (ret) 837 return NULL; 838 839 es = kzalloc(sizeof(*es), GFP_KERNEL); 840 if (!es) 841 return NULL; 842 es->sb = sb; 843 es->modified = false; 844 845 /* byte offset in cluster */ 846 byte_offset = EXFAT_CLU_OFFSET(byte_offset, sbi); 847 848 /* byte offset in sector */ 849 off = EXFAT_BLK_OFFSET(byte_offset, sb); 850 es->start_off = off; 851 852 /* sector offset in cluster */ 853 sec = EXFAT_B_TO_BLK(byte_offset, sb); 854 sec += exfat_cluster_to_sector(sbi, clu); 855 856 bh = sb_bread(sb, sec); 857 if (!bh) 858 goto free_es; 859 es->bh[es->num_bh++] = bh; 860 861 ep = exfat_get_dentry_cached(es, 0); 862 if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode)) 863 goto free_es; 864 865 num_entries = type == ES_ALL_ENTRIES ? 866 ep->dentry.file.num_ext + 1 : type; 867 es->num_entries = num_entries; 868 869 num_bh = EXFAT_B_TO_BLK_ROUND_UP(off + num_entries * DENTRY_SIZE, sb); 870 for (i = 1; i < num_bh; i++) { 871 /* get the next sector */ 872 if (exfat_is_last_sector_in_cluster(sbi, sec)) { 873 if (p_dir->flags == ALLOC_NO_FAT_CHAIN) 874 clu++; 875 else if (exfat_get_next_cluster(sb, &clu)) 876 goto free_es; 877 sec = exfat_cluster_to_sector(sbi, clu); 878 } else { 879 sec++; 880 } 881 882 bh = sb_bread(sb, sec); 883 if (!bh) 884 goto free_es; 885 es->bh[es->num_bh++] = bh; 886 } 887 888 /* validiate cached dentries */ 889 for (i = 1; i < num_entries; i++) { 890 ep = exfat_get_dentry_cached(es, i); 891 if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode)) 892 goto free_es; 893 } 894 return es; 895 896 free_es: 897 exfat_free_dentry_set(es, false); 898 return NULL; 899 } 900 901 enum { 902 DIRENT_STEP_FILE, 903 DIRENT_STEP_STRM, 904 DIRENT_STEP_NAME, 905 DIRENT_STEP_SECD, 906 }; 907 908 /* 909 * return values: 910 * >= 0 : return dir entiry position with the name in dir 911 * -ENOENT : entry with the name does not exist 912 * -EIO : I/O error 913 */ 914 int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei, 915 struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname, 916 int num_entries, unsigned int type) 917 { 918 int i, rewind = 0, dentry = 0, end_eidx = 0, num_ext = 0, len; 919 int order, step, name_len = 0; 920 int dentries_per_clu, num_empty = 0; 921 unsigned int entry_type; 922 unsigned short *uniname = NULL; 923 struct exfat_chain clu; 924 struct exfat_hint *hint_stat = &ei->hint_stat; 925 struct exfat_hint_femp candi_empty; 926 struct exfat_sb_info *sbi = EXFAT_SB(sb); 927 928 dentries_per_clu = sbi->dentries_per_clu; 929 930 exfat_chain_dup(&clu, p_dir); 931 932 if (hint_stat->eidx) { 933 clu.dir = hint_stat->clu; 934 dentry = hint_stat->eidx; 935 end_eidx = dentry; 936 } 937 938 candi_empty.eidx = EXFAT_HINT_NONE; 939 rewind: 940 order = 0; 941 step = DIRENT_STEP_FILE; 942 while (clu.dir != EXFAT_EOF_CLUSTER) { 943 i = dentry & (dentries_per_clu - 1); 944 for (; i < dentries_per_clu; i++, dentry++) { 945 struct exfat_dentry *ep; 946 struct buffer_head *bh; 947 948 if (rewind && dentry == end_eidx) 949 goto not_found; 950 951 ep = exfat_get_dentry(sb, &clu, i, &bh, NULL); 952 if (!ep) 953 return -EIO; 954 955 entry_type = exfat_get_entry_type(ep); 956 957 if (entry_type == TYPE_UNUSED || 958 entry_type == TYPE_DELETED) { 959 step = DIRENT_STEP_FILE; 960 961 num_empty++; 962 if (candi_empty.eidx == EXFAT_HINT_NONE && 963 num_empty == 1) { 964 exfat_chain_set(&candi_empty.cur, 965 clu.dir, clu.size, clu.flags); 966 } 967 968 if (candi_empty.eidx == EXFAT_HINT_NONE && 969 num_empty >= num_entries) { 970 candi_empty.eidx = 971 dentry - (num_empty - 1); 972 WARN_ON(candi_empty.eidx < 0); 973 candi_empty.count = num_empty; 974 975 if (ei->hint_femp.eidx == 976 EXFAT_HINT_NONE || 977 candi_empty.eidx <= 978 ei->hint_femp.eidx) 979 ei->hint_femp = candi_empty; 980 } 981 982 brelse(bh); 983 if (entry_type == TYPE_UNUSED) 984 goto not_found; 985 continue; 986 } 987 988 num_empty = 0; 989 candi_empty.eidx = EXFAT_HINT_NONE; 990 991 if (entry_type == TYPE_FILE || entry_type == TYPE_DIR) { 992 step = DIRENT_STEP_FILE; 993 if (type == TYPE_ALL || type == entry_type) { 994 num_ext = ep->dentry.file.num_ext; 995 step = DIRENT_STEP_STRM; 996 } 997 brelse(bh); 998 continue; 999 } 1000 1001 if (entry_type == TYPE_STREAM) { 1002 u16 name_hash; 1003 1004 if (step != DIRENT_STEP_STRM) { 1005 step = DIRENT_STEP_FILE; 1006 brelse(bh); 1007 continue; 1008 } 1009 step = DIRENT_STEP_FILE; 1010 name_hash = le16_to_cpu( 1011 ep->dentry.stream.name_hash); 1012 if (p_uniname->name_hash == name_hash && 1013 p_uniname->name_len == 1014 ep->dentry.stream.name_len) { 1015 step = DIRENT_STEP_NAME; 1016 order = 1; 1017 name_len = 0; 1018 } 1019 brelse(bh); 1020 continue; 1021 } 1022 1023 brelse(bh); 1024 if (entry_type == TYPE_EXTEND) { 1025 unsigned short entry_uniname[16], unichar; 1026 1027 if (step != DIRENT_STEP_NAME) { 1028 step = DIRENT_STEP_FILE; 1029 continue; 1030 } 1031 1032 if (++order == 2) 1033 uniname = p_uniname->name; 1034 else 1035 uniname += EXFAT_FILE_NAME_LEN; 1036 1037 len = exfat_extract_uni_name(ep, entry_uniname); 1038 name_len += len; 1039 1040 unichar = *(uniname+len); 1041 *(uniname+len) = 0x0; 1042 1043 if (exfat_uniname_ncmp(sb, uniname, 1044 entry_uniname, len)) { 1045 step = DIRENT_STEP_FILE; 1046 } else if (p_uniname->name_len == name_len) { 1047 if (order == num_ext) 1048 goto found; 1049 step = DIRENT_STEP_SECD; 1050 } 1051 1052 *(uniname+len) = unichar; 1053 continue; 1054 } 1055 1056 if (entry_type & 1057 (TYPE_CRITICAL_SEC | TYPE_BENIGN_SEC)) { 1058 if (step == DIRENT_STEP_SECD) { 1059 if (++order == num_ext) 1060 goto found; 1061 continue; 1062 } 1063 } 1064 step = DIRENT_STEP_FILE; 1065 } 1066 1067 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1068 if (--clu.size > 0) 1069 clu.dir++; 1070 else 1071 clu.dir = EXFAT_EOF_CLUSTER; 1072 } else { 1073 if (exfat_get_next_cluster(sb, &clu.dir)) 1074 return -EIO; 1075 } 1076 } 1077 1078 not_found: 1079 /* 1080 * We started at not 0 index,so we should try to find target 1081 * from 0 index to the index we started at. 1082 */ 1083 if (!rewind && end_eidx) { 1084 rewind = 1; 1085 dentry = 0; 1086 clu.dir = p_dir->dir; 1087 /* reset empty hint */ 1088 num_empty = 0; 1089 candi_empty.eidx = EXFAT_HINT_NONE; 1090 goto rewind; 1091 } 1092 1093 /* initialized hint_stat */ 1094 hint_stat->clu = p_dir->dir; 1095 hint_stat->eidx = 0; 1096 return -ENOENT; 1097 1098 found: 1099 /* next dentry we'll find is out of this cluster */ 1100 if (!((dentry + 1) & (dentries_per_clu - 1))) { 1101 int ret = 0; 1102 1103 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1104 if (--clu.size > 0) 1105 clu.dir++; 1106 else 1107 clu.dir = EXFAT_EOF_CLUSTER; 1108 } else { 1109 ret = exfat_get_next_cluster(sb, &clu.dir); 1110 } 1111 1112 if (ret || clu.dir == EXFAT_EOF_CLUSTER) { 1113 /* just initialized hint_stat */ 1114 hint_stat->clu = p_dir->dir; 1115 hint_stat->eidx = 0; 1116 return (dentry - num_ext); 1117 } 1118 } 1119 1120 hint_stat->clu = clu.dir; 1121 hint_stat->eidx = dentry + 1; 1122 return dentry - num_ext; 1123 } 1124 1125 int exfat_count_ext_entries(struct super_block *sb, struct exfat_chain *p_dir, 1126 int entry, struct exfat_dentry *ep) 1127 { 1128 int i, count = 0; 1129 unsigned int type; 1130 struct exfat_dentry *ext_ep; 1131 struct buffer_head *bh; 1132 1133 for (i = 0, entry++; i < ep->dentry.file.num_ext; i++, entry++) { 1134 ext_ep = exfat_get_dentry(sb, p_dir, entry, &bh, NULL); 1135 if (!ext_ep) 1136 return -EIO; 1137 1138 type = exfat_get_entry_type(ext_ep); 1139 brelse(bh); 1140 if (type == TYPE_EXTEND || type == TYPE_STREAM) 1141 count++; 1142 else 1143 break; 1144 } 1145 return count; 1146 } 1147 1148 int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir) 1149 { 1150 int i, count = 0; 1151 int dentries_per_clu; 1152 unsigned int entry_type; 1153 struct exfat_chain clu; 1154 struct exfat_dentry *ep; 1155 struct exfat_sb_info *sbi = EXFAT_SB(sb); 1156 struct buffer_head *bh; 1157 1158 dentries_per_clu = sbi->dentries_per_clu; 1159 1160 exfat_chain_dup(&clu, p_dir); 1161 1162 while (clu.dir != EXFAT_EOF_CLUSTER) { 1163 for (i = 0; i < dentries_per_clu; i++) { 1164 ep = exfat_get_dentry(sb, &clu, i, &bh, NULL); 1165 if (!ep) 1166 return -EIO; 1167 entry_type = exfat_get_entry_type(ep); 1168 brelse(bh); 1169 1170 if (entry_type == TYPE_UNUSED) 1171 return count; 1172 if (entry_type != TYPE_DIR) 1173 continue; 1174 count++; 1175 } 1176 1177 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1178 if (--clu.size > 0) 1179 clu.dir++; 1180 else 1181 clu.dir = EXFAT_EOF_CLUSTER; 1182 } else { 1183 if (exfat_get_next_cluster(sb, &(clu.dir))) 1184 return -EIO; 1185 } 1186 } 1187 1188 return count; 1189 } 1190