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, struct exfat_dir_entry *dir_entry) 63 { 64 int i, dentries_per_clu, dentries_per_clu_bits = 0; 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 = ei->rwoffset & 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 dir_entry->attr = le16_to_cpu(ep->dentry.file.attr); 131 exfat_get_entry_time(sbi, &dir_entry->crtime, 132 ep->dentry.file.create_tz, 133 ep->dentry.file.create_time, 134 ep->dentry.file.create_date, 135 ep->dentry.file.create_time_cs); 136 exfat_get_entry_time(sbi, &dir_entry->mtime, 137 ep->dentry.file.modify_tz, 138 ep->dentry.file.modify_time, 139 ep->dentry.file.modify_date, 140 ep->dentry.file.modify_time_cs); 141 exfat_get_entry_time(sbi, &dir_entry->atime, 142 ep->dentry.file.access_tz, 143 ep->dentry.file.access_time, 144 ep->dentry.file.access_date, 145 0); 146 147 *uni_name.name = 0x0; 148 exfat_get_uniname_from_ext_entry(sb, &dir, dentry, 149 uni_name.name); 150 exfat_utf16_to_nls(sb, &uni_name, 151 dir_entry->namebuf.lfn, 152 dir_entry->namebuf.lfnbuf_len); 153 brelse(bh); 154 155 ep = exfat_get_dentry(sb, &clu, i + 1, &bh, NULL); 156 if (!ep) 157 return -EIO; 158 dir_entry->size = 159 le64_to_cpu(ep->dentry.stream.valid_size); 160 brelse(bh); 161 162 ei->hint_bmap.off = dentry >> dentries_per_clu_bits; 163 ei->hint_bmap.clu = clu.dir; 164 165 ei->rwoffset = ++dentry; 166 return 0; 167 } 168 169 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 170 if (--clu.size > 0) 171 clu.dir++; 172 else 173 clu.dir = EXFAT_EOF_CLUSTER; 174 } else { 175 if (exfat_get_next_cluster(sb, &(clu.dir))) 176 return -EIO; 177 } 178 } 179 180 dir_entry->namebuf.lfn[0] = '\0'; 181 ei->rwoffset = dentry; 182 return 0; 183 } 184 185 static void exfat_init_namebuf(struct exfat_dentry_namebuf *nb) 186 { 187 nb->lfn = NULL; 188 nb->lfnbuf_len = 0; 189 } 190 191 static int exfat_alloc_namebuf(struct exfat_dentry_namebuf *nb) 192 { 193 nb->lfn = __getname(); 194 if (!nb->lfn) 195 return -ENOMEM; 196 nb->lfnbuf_len = MAX_VFSNAME_BUF_SIZE; 197 return 0; 198 } 199 200 static void exfat_free_namebuf(struct exfat_dentry_namebuf *nb) 201 { 202 if (!nb->lfn) 203 return; 204 205 __putname(nb->lfn); 206 exfat_init_namebuf(nb); 207 } 208 209 /* skip iterating emit_dots when dir is empty */ 210 #define ITER_POS_FILLED_DOTS (2) 211 static int exfat_iterate(struct file *filp, struct dir_context *ctx) 212 { 213 struct inode *inode = filp->f_path.dentry->d_inode; 214 struct super_block *sb = inode->i_sb; 215 struct inode *tmp; 216 struct exfat_dir_entry de; 217 struct exfat_dentry_namebuf *nb = &(de.namebuf); 218 struct exfat_inode_info *ei = EXFAT_I(inode); 219 unsigned long inum; 220 loff_t cpos, i_pos; 221 int err = 0, fake_offset = 0; 222 223 exfat_init_namebuf(nb); 224 mutex_lock(&EXFAT_SB(sb)->s_lock); 225 226 cpos = ctx->pos; 227 if (!dir_emit_dots(filp, ctx)) 228 goto unlock; 229 230 if (ctx->pos == ITER_POS_FILLED_DOTS) { 231 cpos = 0; 232 fake_offset = 1; 233 } 234 235 if (cpos & (DENTRY_SIZE - 1)) { 236 err = -ENOENT; 237 goto unlock; 238 } 239 240 /* name buffer should be allocated before use */ 241 err = exfat_alloc_namebuf(nb); 242 if (err) 243 goto unlock; 244 get_new: 245 ei->rwoffset = EXFAT_B_TO_DEN(cpos); 246 247 if (cpos >= i_size_read(inode)) 248 goto end_of_dir; 249 250 err = exfat_readdir(inode, &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 cpos = EXFAT_DEN_TO_B(ei->rwoffset); 266 267 if (!nb->lfn[0]) 268 goto end_of_dir; 269 270 i_pos = ((loff_t)ei->start_clu << 32) | 271 ((ei->rwoffset - 1) & 0xffffffff); 272 tmp = exfat_iget(sb, i_pos); 273 if (tmp) { 274 inum = tmp->i_ino; 275 iput(tmp); 276 } else { 277 inum = iunique(sb, EXFAT_ROOT_INO); 278 } 279 280 /* 281 * Before calling dir_emit(), sb_lock should be released. 282 * Because page fault can occur in dir_emit() when the size 283 * of buffer given from user is larger than one page size. 284 */ 285 mutex_unlock(&EXFAT_SB(sb)->s_lock); 286 if (!dir_emit(ctx, nb->lfn, strlen(nb->lfn), inum, 287 (de.attr & ATTR_SUBDIR) ? DT_DIR : DT_REG)) 288 goto out_unlocked; 289 mutex_lock(&EXFAT_SB(sb)->s_lock); 290 ctx->pos = cpos; 291 goto get_new; 292 293 end_of_dir: 294 if (!cpos && fake_offset) 295 cpos = ITER_POS_FILLED_DOTS; 296 ctx->pos = cpos; 297 unlock: 298 mutex_unlock(&EXFAT_SB(sb)->s_lock); 299 out_unlocked: 300 /* 301 * To improve performance, free namebuf after unlock sb_lock. 302 * If namebuf is not allocated, this function do nothing 303 */ 304 exfat_free_namebuf(nb); 305 return err; 306 } 307 308 const struct file_operations exfat_dir_operations = { 309 .llseek = generic_file_llseek, 310 .read = generic_read_dir, 311 .iterate = exfat_iterate, 312 .fsync = generic_file_fsync, 313 }; 314 315 int exfat_alloc_new_dir(struct inode *inode, struct exfat_chain *clu) 316 { 317 int ret; 318 319 exfat_chain_set(clu, EXFAT_EOF_CLUSTER, 0, ALLOC_NO_FAT_CHAIN); 320 321 ret = exfat_alloc_cluster(inode, 1, clu); 322 if (ret) 323 return ret; 324 325 return exfat_zeroed_cluster(inode, clu->dir); 326 } 327 328 int exfat_calc_num_entries(struct exfat_uni_name *p_uniname) 329 { 330 int len; 331 332 len = p_uniname->name_len; 333 if (len == 0) 334 return -EINVAL; 335 336 /* 1 file entry + 1 stream entry + name entries */ 337 return ((len - 1) / EXFAT_FILE_NAME_LEN + 3); 338 } 339 340 unsigned int exfat_get_entry_type(struct exfat_dentry *ep) 341 { 342 if (ep->type == EXFAT_UNUSED) 343 return TYPE_UNUSED; 344 if (IS_EXFAT_DELETED(ep->type)) 345 return TYPE_DELETED; 346 if (ep->type == EXFAT_INVAL) 347 return TYPE_INVALID; 348 if (IS_EXFAT_CRITICAL_PRI(ep->type)) { 349 if (ep->type == EXFAT_BITMAP) 350 return TYPE_BITMAP; 351 if (ep->type == EXFAT_UPCASE) 352 return TYPE_UPCASE; 353 if (ep->type == EXFAT_VOLUME) 354 return TYPE_VOLUME; 355 if (ep->type == EXFAT_FILE) { 356 if (le16_to_cpu(ep->dentry.file.attr) & ATTR_SUBDIR) 357 return TYPE_DIR; 358 return TYPE_FILE; 359 } 360 return TYPE_CRITICAL_PRI; 361 } 362 if (IS_EXFAT_BENIGN_PRI(ep->type)) { 363 if (ep->type == EXFAT_GUID) 364 return TYPE_GUID; 365 if (ep->type == EXFAT_PADDING) 366 return TYPE_PADDING; 367 if (ep->type == EXFAT_ACLTAB) 368 return TYPE_ACLTAB; 369 return TYPE_BENIGN_PRI; 370 } 371 if (IS_EXFAT_CRITICAL_SEC(ep->type)) { 372 if (ep->type == EXFAT_STREAM) 373 return TYPE_STREAM; 374 if (ep->type == EXFAT_NAME) 375 return TYPE_EXTEND; 376 if (ep->type == EXFAT_ACL) 377 return TYPE_ACL; 378 return TYPE_CRITICAL_SEC; 379 } 380 return TYPE_BENIGN_SEC; 381 } 382 383 static void exfat_set_entry_type(struct exfat_dentry *ep, unsigned int type) 384 { 385 if (type == TYPE_UNUSED) { 386 ep->type = EXFAT_UNUSED; 387 } else if (type == TYPE_DELETED) { 388 ep->type &= EXFAT_DELETE; 389 } else if (type == TYPE_STREAM) { 390 ep->type = EXFAT_STREAM; 391 } else if (type == TYPE_EXTEND) { 392 ep->type = EXFAT_NAME; 393 } else if (type == TYPE_BITMAP) { 394 ep->type = EXFAT_BITMAP; 395 } else if (type == TYPE_UPCASE) { 396 ep->type = EXFAT_UPCASE; 397 } else if (type == TYPE_VOLUME) { 398 ep->type = EXFAT_VOLUME; 399 } else if (type == TYPE_DIR) { 400 ep->type = EXFAT_FILE; 401 ep->dentry.file.attr = cpu_to_le16(ATTR_SUBDIR); 402 } else if (type == TYPE_FILE) { 403 ep->type = EXFAT_FILE; 404 ep->dentry.file.attr = cpu_to_le16(ATTR_ARCHIVE); 405 } 406 } 407 408 static void exfat_init_stream_entry(struct exfat_dentry *ep, 409 unsigned char flags, unsigned int start_clu, 410 unsigned long long size) 411 { 412 exfat_set_entry_type(ep, TYPE_STREAM); 413 ep->dentry.stream.flags = flags; 414 ep->dentry.stream.start_clu = cpu_to_le32(start_clu); 415 ep->dentry.stream.valid_size = cpu_to_le64(size); 416 ep->dentry.stream.size = cpu_to_le64(size); 417 } 418 419 static void exfat_init_name_entry(struct exfat_dentry *ep, 420 unsigned short *uniname) 421 { 422 int i; 423 424 exfat_set_entry_type(ep, TYPE_EXTEND); 425 ep->dentry.name.flags = 0x0; 426 427 for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) { 428 ep->dentry.name.unicode_0_14[i] = cpu_to_le16(*uniname); 429 if (*uniname == 0x0) 430 break; 431 uniname++; 432 } 433 } 434 435 int exfat_init_dir_entry(struct inode *inode, struct exfat_chain *p_dir, 436 int entry, unsigned int type, unsigned int start_clu, 437 unsigned long long size) 438 { 439 struct super_block *sb = inode->i_sb; 440 struct exfat_sb_info *sbi = EXFAT_SB(sb); 441 struct timespec64 ts = current_time(inode); 442 sector_t sector; 443 struct exfat_dentry *ep; 444 struct buffer_head *bh; 445 446 /* 447 * We cannot use exfat_get_dentry_set here because file ep is not 448 * initialized yet. 449 */ 450 ep = exfat_get_dentry(sb, p_dir, entry, &bh, §or); 451 if (!ep) 452 return -EIO; 453 454 exfat_set_entry_type(ep, type); 455 exfat_set_entry_time(sbi, &ts, 456 &ep->dentry.file.create_tz, 457 &ep->dentry.file.create_time, 458 &ep->dentry.file.create_date, 459 &ep->dentry.file.create_time_cs); 460 exfat_set_entry_time(sbi, &ts, 461 &ep->dentry.file.modify_tz, 462 &ep->dentry.file.modify_time, 463 &ep->dentry.file.modify_date, 464 &ep->dentry.file.modify_time_cs); 465 exfat_set_entry_time(sbi, &ts, 466 &ep->dentry.file.access_tz, 467 &ep->dentry.file.access_time, 468 &ep->dentry.file.access_date, 469 NULL); 470 471 exfat_update_bh(sb, bh, IS_DIRSYNC(inode)); 472 brelse(bh); 473 474 ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh, §or); 475 if (!ep) 476 return -EIO; 477 478 exfat_init_stream_entry(ep, 479 (type == TYPE_FILE) ? ALLOC_FAT_CHAIN : ALLOC_NO_FAT_CHAIN, 480 start_clu, size); 481 exfat_update_bh(sb, bh, IS_DIRSYNC(inode)); 482 brelse(bh); 483 484 return 0; 485 } 486 487 int exfat_update_dir_chksum(struct inode *inode, struct exfat_chain *p_dir, 488 int entry) 489 { 490 struct super_block *sb = inode->i_sb; 491 int ret = 0; 492 int i, num_entries; 493 sector_t sector; 494 u16 chksum; 495 struct exfat_dentry *ep, *fep; 496 struct buffer_head *fbh, *bh; 497 498 fep = exfat_get_dentry(sb, p_dir, entry, &fbh, §or); 499 if (!fep) 500 return -EIO; 501 502 num_entries = fep->dentry.file.num_ext + 1; 503 chksum = exfat_calc_chksum16(fep, DENTRY_SIZE, 0, CS_DIR_ENTRY); 504 505 for (i = 1; i < num_entries; i++) { 506 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh, NULL); 507 if (!ep) { 508 ret = -EIO; 509 goto release_fbh; 510 } 511 chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum, 512 CS_DEFAULT); 513 brelse(bh); 514 } 515 516 fep->dentry.file.checksum = cpu_to_le16(chksum); 517 exfat_update_bh(sb, fbh, IS_DIRSYNC(inode)); 518 release_fbh: 519 brelse(fbh); 520 return ret; 521 } 522 523 int exfat_init_ext_entry(struct inode *inode, struct exfat_chain *p_dir, 524 int entry, int num_entries, struct exfat_uni_name *p_uniname) 525 { 526 struct super_block *sb = inode->i_sb; 527 int i; 528 sector_t sector; 529 unsigned short *uniname = p_uniname->name; 530 struct exfat_dentry *ep; 531 struct buffer_head *bh; 532 int sync = IS_DIRSYNC(inode); 533 534 ep = exfat_get_dentry(sb, p_dir, entry, &bh, §or); 535 if (!ep) 536 return -EIO; 537 538 ep->dentry.file.num_ext = (unsigned char)(num_entries - 1); 539 exfat_update_bh(sb, bh, sync); 540 brelse(bh); 541 542 ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh, §or); 543 if (!ep) 544 return -EIO; 545 546 ep->dentry.stream.name_len = p_uniname->name_len; 547 ep->dentry.stream.name_hash = cpu_to_le16(p_uniname->name_hash); 548 exfat_update_bh(sb, bh, sync); 549 brelse(bh); 550 551 for (i = EXFAT_FIRST_CLUSTER; i < num_entries; i++) { 552 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh, §or); 553 if (!ep) 554 return -EIO; 555 556 exfat_init_name_entry(ep, uniname); 557 exfat_update_bh(sb, bh, sync); 558 brelse(bh); 559 uniname += EXFAT_FILE_NAME_LEN; 560 } 561 562 exfat_update_dir_chksum(inode, p_dir, entry); 563 return 0; 564 } 565 566 int exfat_remove_entries(struct inode *inode, struct exfat_chain *p_dir, 567 int entry, int order, int num_entries) 568 { 569 struct super_block *sb = inode->i_sb; 570 int i; 571 sector_t sector; 572 struct exfat_dentry *ep; 573 struct buffer_head *bh; 574 575 for (i = order; i < num_entries; i++) { 576 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh, §or); 577 if (!ep) 578 return -EIO; 579 580 exfat_set_entry_type(ep, TYPE_DELETED); 581 exfat_update_bh(sb, bh, IS_DIRSYNC(inode)); 582 brelse(bh); 583 } 584 585 return 0; 586 } 587 588 void exfat_update_dir_chksum_with_entry_set(struct exfat_entry_set_cache *es) 589 { 590 int chksum_type = CS_DIR_ENTRY, i; 591 unsigned short chksum = 0; 592 struct exfat_dentry *ep; 593 594 for (i = 0; i < es->num_entries; i++) { 595 ep = exfat_get_dentry_cached(es, i); 596 chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum, 597 chksum_type); 598 chksum_type = CS_DEFAULT; 599 } 600 ep = exfat_get_dentry_cached(es, 0); 601 ep->dentry.file.checksum = cpu_to_le16(chksum); 602 es->modified = true; 603 } 604 605 void exfat_free_dentry_set(struct exfat_entry_set_cache *es, int sync) 606 { 607 int i; 608 609 for (i = 0; i < es->num_bh; i++) { 610 if (es->modified) 611 exfat_update_bh(es->sb, es->bh[i], sync); 612 brelse(es->bh[i]); 613 } 614 kfree(es); 615 } 616 617 static int exfat_walk_fat_chain(struct super_block *sb, 618 struct exfat_chain *p_dir, unsigned int byte_offset, 619 unsigned int *clu) 620 { 621 struct exfat_sb_info *sbi = EXFAT_SB(sb); 622 unsigned int clu_offset; 623 unsigned int cur_clu; 624 625 clu_offset = EXFAT_B_TO_CLU(byte_offset, sbi); 626 cur_clu = p_dir->dir; 627 628 if (p_dir->flags == ALLOC_NO_FAT_CHAIN) { 629 cur_clu += clu_offset; 630 } else { 631 while (clu_offset > 0) { 632 if (exfat_get_next_cluster(sb, &cur_clu)) 633 return -EIO; 634 if (cur_clu == EXFAT_EOF_CLUSTER) { 635 exfat_fs_error(sb, 636 "invalid dentry access beyond EOF (clu : %u, eidx : %d)", 637 p_dir->dir, 638 EXFAT_B_TO_DEN(byte_offset)); 639 return -EIO; 640 } 641 clu_offset--; 642 } 643 } 644 645 *clu = cur_clu; 646 return 0; 647 } 648 649 int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir, 650 int entry, sector_t *sector, int *offset) 651 { 652 int ret; 653 unsigned int off, clu = 0; 654 struct exfat_sb_info *sbi = EXFAT_SB(sb); 655 656 off = EXFAT_DEN_TO_B(entry); 657 658 ret = exfat_walk_fat_chain(sb, p_dir, off, &clu); 659 if (ret) 660 return ret; 661 662 /* byte offset in cluster */ 663 off = EXFAT_CLU_OFFSET(off, sbi); 664 665 /* byte offset in sector */ 666 *offset = EXFAT_BLK_OFFSET(off, sb); 667 668 /* sector offset in cluster */ 669 *sector = EXFAT_B_TO_BLK(off, sb); 670 *sector += exfat_cluster_to_sector(sbi, clu); 671 return 0; 672 } 673 674 #define EXFAT_MAX_RA_SIZE (128*1024) 675 static int exfat_dir_readahead(struct super_block *sb, sector_t sec) 676 { 677 struct exfat_sb_info *sbi = EXFAT_SB(sb); 678 struct buffer_head *bh; 679 unsigned int max_ra_count = EXFAT_MAX_RA_SIZE >> sb->s_blocksize_bits; 680 unsigned int page_ra_count = PAGE_SIZE >> sb->s_blocksize_bits; 681 unsigned int adj_ra_count = max(sbi->sect_per_clus, page_ra_count); 682 unsigned int ra_count = min(adj_ra_count, max_ra_count); 683 684 /* Read-ahead is not required */ 685 if (sbi->sect_per_clus == 1) 686 return 0; 687 688 if (sec < sbi->data_start_sector) { 689 exfat_err(sb, "requested sector is invalid(sect:%llu, root:%llu)", 690 (unsigned long long)sec, sbi->data_start_sector); 691 return -EIO; 692 } 693 694 /* Not sector aligned with ra_count, resize ra_count to page size */ 695 if ((sec - sbi->data_start_sector) & (ra_count - 1)) 696 ra_count = page_ra_count; 697 698 bh = sb_find_get_block(sb, sec); 699 if (!bh || !buffer_uptodate(bh)) { 700 unsigned int i; 701 702 for (i = 0; i < ra_count; i++) 703 sb_breadahead(sb, (sector_t)(sec + i)); 704 } 705 brelse(bh); 706 return 0; 707 } 708 709 struct exfat_dentry *exfat_get_dentry(struct super_block *sb, 710 struct exfat_chain *p_dir, int entry, struct buffer_head **bh, 711 sector_t *sector) 712 { 713 unsigned int dentries_per_page = EXFAT_B_TO_DEN(PAGE_SIZE); 714 int off; 715 sector_t sec; 716 717 if (p_dir->dir == DIR_DELETED) { 718 exfat_err(sb, "abnormal access to deleted dentry"); 719 return NULL; 720 } 721 722 if (exfat_find_location(sb, p_dir, entry, &sec, &off)) 723 return NULL; 724 725 if (p_dir->dir != EXFAT_FREE_CLUSTER && 726 !(entry & (dentries_per_page - 1))) 727 exfat_dir_readahead(sb, sec); 728 729 *bh = sb_bread(sb, sec); 730 if (!*bh) 731 return NULL; 732 733 if (sector) 734 *sector = sec; 735 return (struct exfat_dentry *)((*bh)->b_data + off); 736 } 737 738 enum exfat_validate_dentry_mode { 739 ES_MODE_STARTED, 740 ES_MODE_GET_FILE_ENTRY, 741 ES_MODE_GET_STRM_ENTRY, 742 ES_MODE_GET_NAME_ENTRY, 743 ES_MODE_GET_CRITICAL_SEC_ENTRY, 744 }; 745 746 static bool exfat_validate_entry(unsigned int type, 747 enum exfat_validate_dentry_mode *mode) 748 { 749 if (type == TYPE_UNUSED || type == TYPE_DELETED) 750 return false; 751 752 switch (*mode) { 753 case ES_MODE_STARTED: 754 if (type != TYPE_FILE && type != TYPE_DIR) 755 return false; 756 *mode = ES_MODE_GET_FILE_ENTRY; 757 return true; 758 case ES_MODE_GET_FILE_ENTRY: 759 if (type != TYPE_STREAM) 760 return false; 761 *mode = ES_MODE_GET_STRM_ENTRY; 762 return true; 763 case ES_MODE_GET_STRM_ENTRY: 764 if (type != TYPE_EXTEND) 765 return false; 766 *mode = ES_MODE_GET_NAME_ENTRY; 767 return true; 768 case ES_MODE_GET_NAME_ENTRY: 769 if (type == TYPE_STREAM) 770 return false; 771 if (type != TYPE_EXTEND) { 772 if (!(type & TYPE_CRITICAL_SEC)) 773 return false; 774 *mode = ES_MODE_GET_CRITICAL_SEC_ENTRY; 775 } 776 return true; 777 case ES_MODE_GET_CRITICAL_SEC_ENTRY: 778 if (type == TYPE_EXTEND || type == TYPE_STREAM) 779 return false; 780 if ((type & TYPE_CRITICAL_SEC) != TYPE_CRITICAL_SEC) 781 return false; 782 return true; 783 default: 784 WARN_ON_ONCE(1); 785 return false; 786 } 787 } 788 789 struct exfat_dentry *exfat_get_dentry_cached( 790 struct exfat_entry_set_cache *es, int num) 791 { 792 int off = es->start_off + num * DENTRY_SIZE; 793 struct buffer_head *bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)]; 794 char *p = bh->b_data + EXFAT_BLK_OFFSET(off, es->sb); 795 796 return (struct exfat_dentry *)p; 797 } 798 799 /* 800 * Returns a set of dentries for a file or dir. 801 * 802 * Note It provides a direct pointer to bh->data via exfat_get_dentry_cached(). 803 * User should call exfat_get_dentry_set() after setting 'modified' to apply 804 * changes made in this entry set to the real device. 805 * 806 * in: 807 * sb+p_dir+entry: indicates a file/dir 808 * type: specifies how many dentries should be included. 809 * return: 810 * pointer of entry set on success, 811 * NULL on failure. 812 */ 813 struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb, 814 struct exfat_chain *p_dir, int entry, unsigned int type) 815 { 816 int ret, i, num_bh; 817 unsigned int off, byte_offset, clu = 0; 818 sector_t sec; 819 struct exfat_sb_info *sbi = EXFAT_SB(sb); 820 struct exfat_entry_set_cache *es; 821 struct exfat_dentry *ep; 822 int num_entries; 823 enum exfat_validate_dentry_mode mode = ES_MODE_STARTED; 824 struct buffer_head *bh; 825 826 if (p_dir->dir == DIR_DELETED) { 827 exfat_err(sb, "access to deleted dentry"); 828 return NULL; 829 } 830 831 byte_offset = EXFAT_DEN_TO_B(entry); 832 ret = exfat_walk_fat_chain(sb, p_dir, byte_offset, &clu); 833 if (ret) 834 return NULL; 835 836 es = kzalloc(sizeof(*es), GFP_KERNEL); 837 if (!es) 838 return NULL; 839 es->sb = sb; 840 es->modified = false; 841 842 /* byte offset in cluster */ 843 byte_offset = EXFAT_CLU_OFFSET(byte_offset, sbi); 844 845 /* byte offset in sector */ 846 off = EXFAT_BLK_OFFSET(byte_offset, sb); 847 es->start_off = off; 848 849 /* sector offset in cluster */ 850 sec = EXFAT_B_TO_BLK(byte_offset, sb); 851 sec += exfat_cluster_to_sector(sbi, clu); 852 853 bh = sb_bread(sb, sec); 854 if (!bh) 855 goto free_es; 856 es->bh[es->num_bh++] = bh; 857 858 ep = exfat_get_dentry_cached(es, 0); 859 if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode)) 860 goto free_es; 861 862 num_entries = type == ES_ALL_ENTRIES ? 863 ep->dentry.file.num_ext + 1 : type; 864 es->num_entries = num_entries; 865 866 num_bh = EXFAT_B_TO_BLK_ROUND_UP(off + num_entries * DENTRY_SIZE, sb); 867 for (i = 1; i < num_bh; i++) { 868 /* get the next sector */ 869 if (exfat_is_last_sector_in_cluster(sbi, sec)) { 870 if (p_dir->flags == ALLOC_NO_FAT_CHAIN) 871 clu++; 872 else if (exfat_get_next_cluster(sb, &clu)) 873 goto free_es; 874 sec = exfat_cluster_to_sector(sbi, clu); 875 } else { 876 sec++; 877 } 878 879 bh = sb_bread(sb, sec); 880 if (!bh) 881 goto free_es; 882 es->bh[es->num_bh++] = bh; 883 } 884 885 /* validiate cached dentries */ 886 for (i = 1; i < num_entries; i++) { 887 ep = exfat_get_dentry_cached(es, i); 888 if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode)) 889 goto free_es; 890 } 891 return es; 892 893 free_es: 894 exfat_free_dentry_set(es, false); 895 return NULL; 896 } 897 898 enum { 899 DIRENT_STEP_FILE, 900 DIRENT_STEP_STRM, 901 DIRENT_STEP_NAME, 902 DIRENT_STEP_SECD, 903 }; 904 905 /* 906 * return values: 907 * >= 0 : return dir entiry position with the name in dir 908 * -EEXIST : (root dir, ".") it is the root dir itself 909 * -ENOENT : entry with the name does not exist 910 * -EIO : I/O error 911 */ 912 int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei, 913 struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname, 914 int num_entries, unsigned int type) 915 { 916 int i, rewind = 0, dentry = 0, end_eidx = 0, num_ext = 0, len; 917 int order, step, name_len = 0; 918 int dentries_per_clu, num_empty = 0; 919 unsigned int entry_type; 920 unsigned short *uniname = NULL; 921 struct exfat_chain clu; 922 struct exfat_hint *hint_stat = &ei->hint_stat; 923 struct exfat_hint_femp candi_empty; 924 struct exfat_sb_info *sbi = EXFAT_SB(sb); 925 926 dentries_per_clu = sbi->dentries_per_clu; 927 928 exfat_chain_dup(&clu, p_dir); 929 930 if (hint_stat->eidx) { 931 clu.dir = hint_stat->clu; 932 dentry = hint_stat->eidx; 933 end_eidx = dentry; 934 } 935 936 candi_empty.eidx = EXFAT_HINT_NONE; 937 rewind: 938 order = 0; 939 step = DIRENT_STEP_FILE; 940 while (clu.dir != EXFAT_EOF_CLUSTER) { 941 i = dentry & (dentries_per_clu - 1); 942 for (; i < dentries_per_clu; i++, dentry++) { 943 struct exfat_dentry *ep; 944 struct buffer_head *bh; 945 946 if (rewind && dentry == end_eidx) 947 goto not_found; 948 949 ep = exfat_get_dentry(sb, &clu, i, &bh, NULL); 950 if (!ep) 951 return -EIO; 952 953 entry_type = exfat_get_entry_type(ep); 954 955 if (entry_type == TYPE_UNUSED || 956 entry_type == TYPE_DELETED) { 957 step = DIRENT_STEP_FILE; 958 959 num_empty++; 960 if (candi_empty.eidx == EXFAT_HINT_NONE && 961 num_empty == 1) { 962 exfat_chain_set(&candi_empty.cur, 963 clu.dir, clu.size, clu.flags); 964 } 965 966 if (candi_empty.eidx == EXFAT_HINT_NONE && 967 num_empty >= num_entries) { 968 candi_empty.eidx = 969 dentry - (num_empty - 1); 970 WARN_ON(candi_empty.eidx < 0); 971 candi_empty.count = num_empty; 972 973 if (ei->hint_femp.eidx == 974 EXFAT_HINT_NONE || 975 candi_empty.eidx <= 976 ei->hint_femp.eidx) { 977 memcpy(&ei->hint_femp, 978 &candi_empty, 979 sizeof(candi_empty)); 980 } 981 } 982 983 brelse(bh); 984 if (entry_type == TYPE_UNUSED) 985 goto not_found; 986 continue; 987 } 988 989 num_empty = 0; 990 candi_empty.eidx = EXFAT_HINT_NONE; 991 992 if (entry_type == TYPE_FILE || entry_type == TYPE_DIR) { 993 step = DIRENT_STEP_FILE; 994 if (type == TYPE_ALL || type == entry_type) { 995 num_ext = ep->dentry.file.num_ext; 996 step = DIRENT_STEP_STRM; 997 } 998 brelse(bh); 999 continue; 1000 } 1001 1002 if (entry_type == TYPE_STREAM) { 1003 u16 name_hash; 1004 1005 if (step != DIRENT_STEP_STRM) { 1006 step = DIRENT_STEP_FILE; 1007 brelse(bh); 1008 continue; 1009 } 1010 step = DIRENT_STEP_FILE; 1011 name_hash = le16_to_cpu( 1012 ep->dentry.stream.name_hash); 1013 if (p_uniname->name_hash == name_hash && 1014 p_uniname->name_len == 1015 ep->dentry.stream.name_len) { 1016 step = DIRENT_STEP_NAME; 1017 order = 1; 1018 name_len = 0; 1019 } 1020 brelse(bh); 1021 continue; 1022 } 1023 1024 brelse(bh); 1025 if (entry_type == TYPE_EXTEND) { 1026 unsigned short entry_uniname[16], unichar; 1027 1028 if (step != DIRENT_STEP_NAME) { 1029 step = DIRENT_STEP_FILE; 1030 continue; 1031 } 1032 1033 if (++order == 2) 1034 uniname = p_uniname->name; 1035 else 1036 uniname += EXFAT_FILE_NAME_LEN; 1037 1038 len = exfat_extract_uni_name(ep, entry_uniname); 1039 name_len += len; 1040 1041 unichar = *(uniname+len); 1042 *(uniname+len) = 0x0; 1043 1044 if (exfat_uniname_ncmp(sb, uniname, 1045 entry_uniname, len)) { 1046 step = DIRENT_STEP_FILE; 1047 } else if (p_uniname->name_len == name_len) { 1048 if (order == num_ext) 1049 goto found; 1050 step = DIRENT_STEP_SECD; 1051 } 1052 1053 *(uniname+len) = unichar; 1054 continue; 1055 } 1056 1057 if (entry_type & 1058 (TYPE_CRITICAL_SEC | TYPE_BENIGN_SEC)) { 1059 if (step == DIRENT_STEP_SECD) { 1060 if (++order == num_ext) 1061 goto found; 1062 continue; 1063 } 1064 } 1065 step = DIRENT_STEP_FILE; 1066 } 1067 1068 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1069 if (--clu.size > 0) 1070 clu.dir++; 1071 else 1072 clu.dir = EXFAT_EOF_CLUSTER; 1073 } else { 1074 if (exfat_get_next_cluster(sb, &clu.dir)) 1075 return -EIO; 1076 } 1077 } 1078 1079 not_found: 1080 /* 1081 * We started at not 0 index,so we should try to find target 1082 * from 0 index to the index we started at. 1083 */ 1084 if (!rewind && end_eidx) { 1085 rewind = 1; 1086 dentry = 0; 1087 clu.dir = p_dir->dir; 1088 /* reset empty hint */ 1089 num_empty = 0; 1090 candi_empty.eidx = EXFAT_HINT_NONE; 1091 goto rewind; 1092 } 1093 1094 /* initialized hint_stat */ 1095 hint_stat->clu = p_dir->dir; 1096 hint_stat->eidx = 0; 1097 return -ENOENT; 1098 1099 found: 1100 /* next dentry we'll find is out of this cluster */ 1101 if (!((dentry + 1) & (dentries_per_clu - 1))) { 1102 int ret = 0; 1103 1104 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1105 if (--clu.size > 0) 1106 clu.dir++; 1107 else 1108 clu.dir = EXFAT_EOF_CLUSTER; 1109 } else { 1110 ret = exfat_get_next_cluster(sb, &clu.dir); 1111 } 1112 1113 if (ret || clu.dir != EXFAT_EOF_CLUSTER) { 1114 /* just initialized hint_stat */ 1115 hint_stat->clu = p_dir->dir; 1116 hint_stat->eidx = 0; 1117 return (dentry - num_ext); 1118 } 1119 } 1120 1121 hint_stat->clu = clu.dir; 1122 hint_stat->eidx = dentry + 1; 1123 return dentry - num_ext; 1124 } 1125 1126 int exfat_count_ext_entries(struct super_block *sb, struct exfat_chain *p_dir, 1127 int entry, struct exfat_dentry *ep) 1128 { 1129 int i, count = 0; 1130 unsigned int type; 1131 struct exfat_dentry *ext_ep; 1132 struct buffer_head *bh; 1133 1134 for (i = 0, entry++; i < ep->dentry.file.num_ext; i++, entry++) { 1135 ext_ep = exfat_get_dentry(sb, p_dir, entry, &bh, NULL); 1136 if (!ext_ep) 1137 return -EIO; 1138 1139 type = exfat_get_entry_type(ext_ep); 1140 brelse(bh); 1141 if (type == TYPE_EXTEND || type == TYPE_STREAM) 1142 count++; 1143 else 1144 break; 1145 } 1146 return count; 1147 } 1148 1149 int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir) 1150 { 1151 int i, count = 0; 1152 int dentries_per_clu; 1153 unsigned int entry_type; 1154 struct exfat_chain clu; 1155 struct exfat_dentry *ep; 1156 struct exfat_sb_info *sbi = EXFAT_SB(sb); 1157 struct buffer_head *bh; 1158 1159 dentries_per_clu = sbi->dentries_per_clu; 1160 1161 exfat_chain_dup(&clu, p_dir); 1162 1163 while (clu.dir != EXFAT_EOF_CLUSTER) { 1164 for (i = 0; i < dentries_per_clu; i++) { 1165 ep = exfat_get_dentry(sb, &clu, i, &bh, NULL); 1166 if (!ep) 1167 return -EIO; 1168 entry_type = exfat_get_entry_type(ep); 1169 brelse(bh); 1170 1171 if (entry_type == TYPE_UNUSED) 1172 return count; 1173 if (entry_type != TYPE_DIR) 1174 continue; 1175 count++; 1176 } 1177 1178 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1179 if (--clu.size > 0) 1180 clu.dir++; 1181 else 1182 clu.dir = EXFAT_EOF_CLUSTER; 1183 } else { 1184 if (exfat_get_next_cluster(sb, &(clu.dir))) 1185 return -EIO; 1186 } 1187 } 1188 1189 return count; 1190 } 1191