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 = exfat_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 if (*uniname != 0x0) { 429 ep->dentry.name.unicode_0_14[i] = cpu_to_le16(*uniname); 430 uniname++; 431 } else { 432 ep->dentry.name.unicode_0_14[i] = 0x0; 433 } 434 } 435 } 436 437 int exfat_init_dir_entry(struct inode *inode, struct exfat_chain *p_dir, 438 int entry, unsigned int type, unsigned int start_clu, 439 unsigned long long size) 440 { 441 struct super_block *sb = inode->i_sb; 442 struct exfat_sb_info *sbi = EXFAT_SB(sb); 443 struct timespec64 ts = current_time(inode); 444 sector_t sector; 445 struct exfat_dentry *ep; 446 struct buffer_head *bh; 447 448 /* 449 * We cannot use exfat_get_dentry_set here because file ep is not 450 * initialized yet. 451 */ 452 ep = exfat_get_dentry(sb, p_dir, entry, &bh, §or); 453 if (!ep) 454 return -EIO; 455 456 exfat_set_entry_type(ep, type); 457 exfat_set_entry_time(sbi, &ts, 458 &ep->dentry.file.create_tz, 459 &ep->dentry.file.create_time, 460 &ep->dentry.file.create_date, 461 &ep->dentry.file.create_time_cs); 462 exfat_set_entry_time(sbi, &ts, 463 &ep->dentry.file.modify_tz, 464 &ep->dentry.file.modify_time, 465 &ep->dentry.file.modify_date, 466 &ep->dentry.file.modify_time_cs); 467 exfat_set_entry_time(sbi, &ts, 468 &ep->dentry.file.access_tz, 469 &ep->dentry.file.access_time, 470 &ep->dentry.file.access_date, 471 NULL); 472 473 exfat_update_bh(sb, bh, IS_DIRSYNC(inode)); 474 brelse(bh); 475 476 ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh, §or); 477 if (!ep) 478 return -EIO; 479 480 exfat_init_stream_entry(ep, 481 (type == TYPE_FILE) ? ALLOC_FAT_CHAIN : ALLOC_NO_FAT_CHAIN, 482 start_clu, size); 483 exfat_update_bh(sb, bh, IS_DIRSYNC(inode)); 484 brelse(bh); 485 486 return 0; 487 } 488 489 int exfat_update_dir_chksum(struct inode *inode, struct exfat_chain *p_dir, 490 int entry) 491 { 492 struct super_block *sb = inode->i_sb; 493 int ret = 0; 494 int i, num_entries; 495 sector_t sector; 496 u16 chksum; 497 struct exfat_dentry *ep, *fep; 498 struct buffer_head *fbh, *bh; 499 500 fep = exfat_get_dentry(sb, p_dir, entry, &fbh, §or); 501 if (!fep) 502 return -EIO; 503 504 num_entries = fep->dentry.file.num_ext + 1; 505 chksum = exfat_calc_chksum16(fep, DENTRY_SIZE, 0, CS_DIR_ENTRY); 506 507 for (i = 1; i < num_entries; i++) { 508 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh, NULL); 509 if (!ep) { 510 ret = -EIO; 511 goto release_fbh; 512 } 513 chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum, 514 CS_DEFAULT); 515 brelse(bh); 516 } 517 518 fep->dentry.file.checksum = cpu_to_le16(chksum); 519 exfat_update_bh(sb, fbh, IS_DIRSYNC(inode)); 520 release_fbh: 521 brelse(fbh); 522 return ret; 523 } 524 525 int exfat_init_ext_entry(struct inode *inode, struct exfat_chain *p_dir, 526 int entry, int num_entries, struct exfat_uni_name *p_uniname) 527 { 528 struct super_block *sb = inode->i_sb; 529 int i; 530 sector_t sector; 531 unsigned short *uniname = p_uniname->name; 532 struct exfat_dentry *ep; 533 struct buffer_head *bh; 534 int sync = IS_DIRSYNC(inode); 535 536 ep = exfat_get_dentry(sb, p_dir, entry, &bh, §or); 537 if (!ep) 538 return -EIO; 539 540 ep->dentry.file.num_ext = (unsigned char)(num_entries - 1); 541 exfat_update_bh(sb, bh, sync); 542 brelse(bh); 543 544 ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh, §or); 545 if (!ep) 546 return -EIO; 547 548 ep->dentry.stream.name_len = p_uniname->name_len; 549 ep->dentry.stream.name_hash = cpu_to_le16(p_uniname->name_hash); 550 exfat_update_bh(sb, bh, sync); 551 brelse(bh); 552 553 for (i = EXFAT_FIRST_CLUSTER; i < num_entries; i++) { 554 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh, §or); 555 if (!ep) 556 return -EIO; 557 558 exfat_init_name_entry(ep, uniname); 559 exfat_update_bh(sb, bh, sync); 560 brelse(bh); 561 uniname += EXFAT_FILE_NAME_LEN; 562 } 563 564 exfat_update_dir_chksum(inode, p_dir, entry); 565 return 0; 566 } 567 568 int exfat_remove_entries(struct inode *inode, struct exfat_chain *p_dir, 569 int entry, int order, int num_entries) 570 { 571 struct super_block *sb = inode->i_sb; 572 int i; 573 sector_t sector; 574 struct exfat_dentry *ep; 575 struct buffer_head *bh; 576 577 for (i = order; i < num_entries; i++) { 578 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh, §or); 579 if (!ep) 580 return -EIO; 581 582 exfat_set_entry_type(ep, TYPE_DELETED); 583 exfat_update_bh(sb, bh, IS_DIRSYNC(inode)); 584 brelse(bh); 585 } 586 587 return 0; 588 } 589 590 void exfat_update_dir_chksum_with_entry_set(struct exfat_entry_set_cache *es) 591 { 592 int chksum_type = CS_DIR_ENTRY, i; 593 unsigned short chksum = 0; 594 struct exfat_dentry *ep; 595 596 for (i = 0; i < es->num_entries; i++) { 597 ep = exfat_get_dentry_cached(es, i); 598 chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum, 599 chksum_type); 600 chksum_type = CS_DEFAULT; 601 } 602 ep = exfat_get_dentry_cached(es, 0); 603 ep->dentry.file.checksum = cpu_to_le16(chksum); 604 es->modified = true; 605 } 606 607 void exfat_free_dentry_set(struct exfat_entry_set_cache *es, int sync) 608 { 609 int i; 610 611 for (i = 0; i < es->num_bh; i++) { 612 if (es->modified) 613 exfat_update_bh(es->sb, es->bh[i], sync); 614 brelse(es->bh[i]); 615 } 616 kfree(es); 617 } 618 619 static int exfat_walk_fat_chain(struct super_block *sb, 620 struct exfat_chain *p_dir, unsigned int byte_offset, 621 unsigned int *clu) 622 { 623 struct exfat_sb_info *sbi = EXFAT_SB(sb); 624 unsigned int clu_offset; 625 unsigned int cur_clu; 626 627 clu_offset = EXFAT_B_TO_CLU(byte_offset, sbi); 628 cur_clu = p_dir->dir; 629 630 if (p_dir->flags == ALLOC_NO_FAT_CHAIN) { 631 cur_clu += clu_offset; 632 } else { 633 while (clu_offset > 0) { 634 if (exfat_get_next_cluster(sb, &cur_clu)) 635 return -EIO; 636 if (cur_clu == EXFAT_EOF_CLUSTER) { 637 exfat_fs_error(sb, 638 "invalid dentry access beyond EOF (clu : %u, eidx : %d)", 639 p_dir->dir, 640 EXFAT_B_TO_DEN(byte_offset)); 641 return -EIO; 642 } 643 clu_offset--; 644 } 645 } 646 647 *clu = cur_clu; 648 return 0; 649 } 650 651 int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir, 652 int entry, sector_t *sector, int *offset) 653 { 654 int ret; 655 unsigned int off, clu = 0; 656 struct exfat_sb_info *sbi = EXFAT_SB(sb); 657 658 off = EXFAT_DEN_TO_B(entry); 659 660 ret = exfat_walk_fat_chain(sb, p_dir, off, &clu); 661 if (ret) 662 return ret; 663 664 /* byte offset in cluster */ 665 off = EXFAT_CLU_OFFSET(off, sbi); 666 667 /* byte offset in sector */ 668 *offset = EXFAT_BLK_OFFSET(off, sb); 669 670 /* sector offset in cluster */ 671 *sector = EXFAT_B_TO_BLK(off, sb); 672 *sector += exfat_cluster_to_sector(sbi, clu); 673 return 0; 674 } 675 676 #define EXFAT_MAX_RA_SIZE (128*1024) 677 static int exfat_dir_readahead(struct super_block *sb, sector_t sec) 678 { 679 struct exfat_sb_info *sbi = EXFAT_SB(sb); 680 struct buffer_head *bh; 681 unsigned int max_ra_count = EXFAT_MAX_RA_SIZE >> sb->s_blocksize_bits; 682 unsigned int page_ra_count = PAGE_SIZE >> sb->s_blocksize_bits; 683 unsigned int adj_ra_count = max(sbi->sect_per_clus, page_ra_count); 684 unsigned int ra_count = min(adj_ra_count, max_ra_count); 685 686 /* Read-ahead is not required */ 687 if (sbi->sect_per_clus == 1) 688 return 0; 689 690 if (sec < sbi->data_start_sector) { 691 exfat_err(sb, "requested sector is invalid(sect:%llu, root:%llu)", 692 (unsigned long long)sec, sbi->data_start_sector); 693 return -EIO; 694 } 695 696 /* Not sector aligned with ra_count, resize ra_count to page size */ 697 if ((sec - sbi->data_start_sector) & (ra_count - 1)) 698 ra_count = page_ra_count; 699 700 bh = sb_find_get_block(sb, sec); 701 if (!bh || !buffer_uptodate(bh)) { 702 unsigned int i; 703 704 for (i = 0; i < ra_count; i++) 705 sb_breadahead(sb, (sector_t)(sec + i)); 706 } 707 brelse(bh); 708 return 0; 709 } 710 711 struct exfat_dentry *exfat_get_dentry(struct super_block *sb, 712 struct exfat_chain *p_dir, int entry, struct buffer_head **bh, 713 sector_t *sector) 714 { 715 unsigned int dentries_per_page = EXFAT_B_TO_DEN(PAGE_SIZE); 716 int off; 717 sector_t sec; 718 719 if (p_dir->dir == DIR_DELETED) { 720 exfat_err(sb, "abnormal access to deleted dentry"); 721 return NULL; 722 } 723 724 if (exfat_find_location(sb, p_dir, entry, &sec, &off)) 725 return NULL; 726 727 if (p_dir->dir != EXFAT_FREE_CLUSTER && 728 !(entry & (dentries_per_page - 1))) 729 exfat_dir_readahead(sb, sec); 730 731 *bh = sb_bread(sb, sec); 732 if (!*bh) 733 return NULL; 734 735 if (sector) 736 *sector = sec; 737 return (struct exfat_dentry *)((*bh)->b_data + off); 738 } 739 740 enum exfat_validate_dentry_mode { 741 ES_MODE_STARTED, 742 ES_MODE_GET_FILE_ENTRY, 743 ES_MODE_GET_STRM_ENTRY, 744 ES_MODE_GET_NAME_ENTRY, 745 ES_MODE_GET_CRITICAL_SEC_ENTRY, 746 }; 747 748 static bool exfat_validate_entry(unsigned int type, 749 enum exfat_validate_dentry_mode *mode) 750 { 751 if (type == TYPE_UNUSED || type == TYPE_DELETED) 752 return false; 753 754 switch (*mode) { 755 case ES_MODE_STARTED: 756 if (type != TYPE_FILE && type != TYPE_DIR) 757 return false; 758 *mode = ES_MODE_GET_FILE_ENTRY; 759 return true; 760 case ES_MODE_GET_FILE_ENTRY: 761 if (type != TYPE_STREAM) 762 return false; 763 *mode = ES_MODE_GET_STRM_ENTRY; 764 return true; 765 case ES_MODE_GET_STRM_ENTRY: 766 if (type != TYPE_EXTEND) 767 return false; 768 *mode = ES_MODE_GET_NAME_ENTRY; 769 return true; 770 case ES_MODE_GET_NAME_ENTRY: 771 if (type == TYPE_STREAM) 772 return false; 773 if (type != TYPE_EXTEND) { 774 if (!(type & TYPE_CRITICAL_SEC)) 775 return false; 776 *mode = ES_MODE_GET_CRITICAL_SEC_ENTRY; 777 } 778 return true; 779 case ES_MODE_GET_CRITICAL_SEC_ENTRY: 780 if (type == TYPE_EXTEND || type == TYPE_STREAM) 781 return false; 782 if ((type & TYPE_CRITICAL_SEC) != TYPE_CRITICAL_SEC) 783 return false; 784 return true; 785 default: 786 WARN_ON_ONCE(1); 787 return false; 788 } 789 } 790 791 struct exfat_dentry *exfat_get_dentry_cached( 792 struct exfat_entry_set_cache *es, int num) 793 { 794 int off = es->start_off + num * DENTRY_SIZE; 795 struct buffer_head *bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)]; 796 char *p = bh->b_data + EXFAT_BLK_OFFSET(off, es->sb); 797 798 return (struct exfat_dentry *)p; 799 } 800 801 /* 802 * Returns a set of dentries for a file or dir. 803 * 804 * Note It provides a direct pointer to bh->data via exfat_get_dentry_cached(). 805 * User should call exfat_get_dentry_set() after setting 'modified' to apply 806 * changes made in this entry set to the real device. 807 * 808 * in: 809 * sb+p_dir+entry: indicates a file/dir 810 * type: specifies how many dentries should be included. 811 * return: 812 * pointer of entry set on success, 813 * NULL on failure. 814 */ 815 struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb, 816 struct exfat_chain *p_dir, int entry, unsigned int type) 817 { 818 int ret, i, num_bh; 819 unsigned int off, byte_offset, clu = 0; 820 sector_t sec; 821 struct exfat_sb_info *sbi = EXFAT_SB(sb); 822 struct exfat_entry_set_cache *es; 823 struct exfat_dentry *ep; 824 int num_entries; 825 enum exfat_validate_dentry_mode mode = ES_MODE_STARTED; 826 struct buffer_head *bh; 827 828 if (p_dir->dir == DIR_DELETED) { 829 exfat_err(sb, "access to deleted dentry"); 830 return NULL; 831 } 832 833 byte_offset = EXFAT_DEN_TO_B(entry); 834 ret = exfat_walk_fat_chain(sb, p_dir, byte_offset, &clu); 835 if (ret) 836 return NULL; 837 838 es = kzalloc(sizeof(*es), GFP_KERNEL); 839 if (!es) 840 return NULL; 841 es->sb = sb; 842 es->modified = false; 843 844 /* byte offset in cluster */ 845 byte_offset = EXFAT_CLU_OFFSET(byte_offset, sbi); 846 847 /* byte offset in sector */ 848 off = EXFAT_BLK_OFFSET(byte_offset, sb); 849 es->start_off = off; 850 851 /* sector offset in cluster */ 852 sec = EXFAT_B_TO_BLK(byte_offset, sb); 853 sec += exfat_cluster_to_sector(sbi, clu); 854 855 bh = sb_bread(sb, sec); 856 if (!bh) 857 goto free_es; 858 es->bh[es->num_bh++] = bh; 859 860 ep = exfat_get_dentry_cached(es, 0); 861 if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode)) 862 goto free_es; 863 864 num_entries = type == ES_ALL_ENTRIES ? 865 ep->dentry.file.num_ext + 1 : type; 866 es->num_entries = num_entries; 867 868 num_bh = EXFAT_B_TO_BLK_ROUND_UP(off + num_entries * DENTRY_SIZE, sb); 869 for (i = 1; i < num_bh; i++) { 870 /* get the next sector */ 871 if (exfat_is_last_sector_in_cluster(sbi, sec)) { 872 if (p_dir->flags == ALLOC_NO_FAT_CHAIN) 873 clu++; 874 else if (exfat_get_next_cluster(sb, &clu)) 875 goto free_es; 876 sec = exfat_cluster_to_sector(sbi, clu); 877 } else { 878 sec++; 879 } 880 881 bh = sb_bread(sb, sec); 882 if (!bh) 883 goto free_es; 884 es->bh[es->num_bh++] = bh; 885 } 886 887 /* validiate cached dentries */ 888 for (i = 1; i < num_entries; i++) { 889 ep = exfat_get_dentry_cached(es, i); 890 if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode)) 891 goto free_es; 892 } 893 return es; 894 895 free_es: 896 exfat_free_dentry_set(es, false); 897 return NULL; 898 } 899 900 enum { 901 DIRENT_STEP_FILE, 902 DIRENT_STEP_STRM, 903 DIRENT_STEP_NAME, 904 DIRENT_STEP_SECD, 905 }; 906 907 /* 908 * return values: 909 * >= 0 : return dir entiry position with the name in dir 910 * -EEXIST : (root dir, ".") it is the root dir itself 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 memcpy(&ei->hint_femp, 980 &candi_empty, 981 sizeof(candi_empty)); 982 } 983 } 984 985 brelse(bh); 986 if (entry_type == TYPE_UNUSED) 987 goto not_found; 988 continue; 989 } 990 991 num_empty = 0; 992 candi_empty.eidx = EXFAT_HINT_NONE; 993 994 if (entry_type == TYPE_FILE || entry_type == TYPE_DIR) { 995 step = DIRENT_STEP_FILE; 996 if (type == TYPE_ALL || type == entry_type) { 997 num_ext = ep->dentry.file.num_ext; 998 step = DIRENT_STEP_STRM; 999 } 1000 brelse(bh); 1001 continue; 1002 } 1003 1004 if (entry_type == TYPE_STREAM) { 1005 u16 name_hash; 1006 1007 if (step != DIRENT_STEP_STRM) { 1008 step = DIRENT_STEP_FILE; 1009 brelse(bh); 1010 continue; 1011 } 1012 step = DIRENT_STEP_FILE; 1013 name_hash = le16_to_cpu( 1014 ep->dentry.stream.name_hash); 1015 if (p_uniname->name_hash == name_hash && 1016 p_uniname->name_len == 1017 ep->dentry.stream.name_len) { 1018 step = DIRENT_STEP_NAME; 1019 order = 1; 1020 name_len = 0; 1021 } 1022 brelse(bh); 1023 continue; 1024 } 1025 1026 brelse(bh); 1027 if (entry_type == TYPE_EXTEND) { 1028 unsigned short entry_uniname[16], unichar; 1029 1030 if (step != DIRENT_STEP_NAME) { 1031 step = DIRENT_STEP_FILE; 1032 continue; 1033 } 1034 1035 if (++order == 2) 1036 uniname = p_uniname->name; 1037 else 1038 uniname += EXFAT_FILE_NAME_LEN; 1039 1040 len = exfat_extract_uni_name(ep, entry_uniname); 1041 name_len += len; 1042 1043 unichar = *(uniname+len); 1044 *(uniname+len) = 0x0; 1045 1046 if (exfat_uniname_ncmp(sb, uniname, 1047 entry_uniname, len)) { 1048 step = DIRENT_STEP_FILE; 1049 } else if (p_uniname->name_len == name_len) { 1050 if (order == num_ext) 1051 goto found; 1052 step = DIRENT_STEP_SECD; 1053 } 1054 1055 *(uniname+len) = unichar; 1056 continue; 1057 } 1058 1059 if (entry_type & 1060 (TYPE_CRITICAL_SEC | TYPE_BENIGN_SEC)) { 1061 if (step == DIRENT_STEP_SECD) { 1062 if (++order == num_ext) 1063 goto found; 1064 continue; 1065 } 1066 } 1067 step = DIRENT_STEP_FILE; 1068 } 1069 1070 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1071 if (--clu.size > 0) 1072 clu.dir++; 1073 else 1074 clu.dir = EXFAT_EOF_CLUSTER; 1075 } else { 1076 if (exfat_get_next_cluster(sb, &clu.dir)) 1077 return -EIO; 1078 } 1079 } 1080 1081 not_found: 1082 /* 1083 * We started at not 0 index,so we should try to find target 1084 * from 0 index to the index we started at. 1085 */ 1086 if (!rewind && end_eidx) { 1087 rewind = 1; 1088 dentry = 0; 1089 clu.dir = p_dir->dir; 1090 /* reset empty hint */ 1091 num_empty = 0; 1092 candi_empty.eidx = EXFAT_HINT_NONE; 1093 goto rewind; 1094 } 1095 1096 /* initialized hint_stat */ 1097 hint_stat->clu = p_dir->dir; 1098 hint_stat->eidx = 0; 1099 return -ENOENT; 1100 1101 found: 1102 /* next dentry we'll find is out of this cluster */ 1103 if (!((dentry + 1) & (dentries_per_clu - 1))) { 1104 int ret = 0; 1105 1106 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1107 if (--clu.size > 0) 1108 clu.dir++; 1109 else 1110 clu.dir = EXFAT_EOF_CLUSTER; 1111 } else { 1112 ret = exfat_get_next_cluster(sb, &clu.dir); 1113 } 1114 1115 if (ret || clu.dir == EXFAT_EOF_CLUSTER) { 1116 /* just initialized hint_stat */ 1117 hint_stat->clu = p_dir->dir; 1118 hint_stat->eidx = 0; 1119 return (dentry - num_ext); 1120 } 1121 } 1122 1123 hint_stat->clu = clu.dir; 1124 hint_stat->eidx = dentry + 1; 1125 return dentry - num_ext; 1126 } 1127 1128 int exfat_count_ext_entries(struct super_block *sb, struct exfat_chain *p_dir, 1129 int entry, struct exfat_dentry *ep) 1130 { 1131 int i, count = 0; 1132 unsigned int type; 1133 struct exfat_dentry *ext_ep; 1134 struct buffer_head *bh; 1135 1136 for (i = 0, entry++; i < ep->dentry.file.num_ext; i++, entry++) { 1137 ext_ep = exfat_get_dentry(sb, p_dir, entry, &bh, NULL); 1138 if (!ext_ep) 1139 return -EIO; 1140 1141 type = exfat_get_entry_type(ext_ep); 1142 brelse(bh); 1143 if (type == TYPE_EXTEND || type == TYPE_STREAM) 1144 count++; 1145 else 1146 break; 1147 } 1148 return count; 1149 } 1150 1151 int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir) 1152 { 1153 int i, count = 0; 1154 int dentries_per_clu; 1155 unsigned int entry_type; 1156 struct exfat_chain clu; 1157 struct exfat_dentry *ep; 1158 struct exfat_sb_info *sbi = EXFAT_SB(sb); 1159 struct buffer_head *bh; 1160 1161 dentries_per_clu = sbi->dentries_per_clu; 1162 1163 exfat_chain_dup(&clu, p_dir); 1164 1165 while (clu.dir != EXFAT_EOF_CLUSTER) { 1166 for (i = 0; i < dentries_per_clu; i++) { 1167 ep = exfat_get_dentry(sb, &clu, i, &bh, NULL); 1168 if (!ep) 1169 return -EIO; 1170 entry_type = exfat_get_entry_type(ep); 1171 brelse(bh); 1172 1173 if (entry_type == TYPE_UNUSED) 1174 return count; 1175 if (entry_type != TYPE_DIR) 1176 continue; 1177 count++; 1178 } 1179 1180 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1181 if (--clu.size > 0) 1182 clu.dir++; 1183 else 1184 clu.dir = EXFAT_EOF_CLUSTER; 1185 } else { 1186 if (exfat_get_next_cluster(sb, &(clu.dir))) 1187 return -EIO; 1188 } 1189 } 1190 1191 return count; 1192 } 1193