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/compat.h> 8 #include <linux/bio.h> 9 #include <linux/buffer_head.h> 10 11 #include "exfat_raw.h" 12 #include "exfat_fs.h" 13 14 static int exfat_extract_uni_name(struct exfat_dentry *ep, 15 unsigned short *uniname) 16 { 17 int i, len = 0; 18 19 for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) { 20 *uniname = le16_to_cpu(ep->dentry.name.unicode_0_14[i]); 21 if (*uniname == 0x0) 22 return len; 23 uniname++; 24 len++; 25 } 26 27 *uniname = 0x0; 28 return len; 29 30 } 31 32 static void exfat_get_uniname_from_ext_entry(struct super_block *sb, 33 struct exfat_chain *p_dir, int entry, unsigned short *uniname) 34 { 35 int i; 36 struct exfat_entry_set_cache *es; 37 38 es = exfat_get_dentry_set(sb, p_dir, entry, ES_ALL_ENTRIES); 39 if (!es) 40 return; 41 42 /* 43 * First entry : file entry 44 * Second entry : stream-extension entry 45 * Third entry : first file-name entry 46 * So, the index of first file-name dentry should start from 2. 47 */ 48 for (i = 2; i < es->num_entries; i++) { 49 struct exfat_dentry *ep = exfat_get_dentry_cached(es, i); 50 51 /* end of name entry */ 52 if (exfat_get_entry_type(ep) != TYPE_EXTEND) 53 break; 54 55 exfat_extract_uni_name(ep, uniname); 56 uniname += EXFAT_FILE_NAME_LEN; 57 } 58 59 exfat_free_dentry_set(es, false); 60 } 61 62 /* read a directory entry from the opened directory */ 63 static int exfat_readdir(struct inode *inode, loff_t *cpos, struct exfat_dir_entry *dir_entry) 64 { 65 int i, dentries_per_clu, dentries_per_clu_bits = 0, num_ext; 66 unsigned int type, clu_offset; 67 sector_t sector; 68 struct exfat_chain dir, clu; 69 struct exfat_uni_name uni_name; 70 struct exfat_dentry *ep; 71 struct super_block *sb = inode->i_sb; 72 struct exfat_sb_info *sbi = EXFAT_SB(sb); 73 struct exfat_inode_info *ei = EXFAT_I(inode); 74 unsigned int dentry = EXFAT_B_TO_DEN(*cpos) & 0xFFFFFFFF; 75 struct buffer_head *bh; 76 77 /* check if the given file ID is opened */ 78 if (ei->type != TYPE_DIR) 79 return -EPERM; 80 81 if (ei->entry == -1) 82 exfat_chain_set(&dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN); 83 else 84 exfat_chain_set(&dir, ei->start_clu, 85 EXFAT_B_TO_CLU(i_size_read(inode), sbi), ei->flags); 86 87 dentries_per_clu = sbi->dentries_per_clu; 88 dentries_per_clu_bits = ilog2(dentries_per_clu); 89 90 clu_offset = dentry >> dentries_per_clu_bits; 91 exfat_chain_dup(&clu, &dir); 92 93 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 94 clu.dir += clu_offset; 95 clu.size -= clu_offset; 96 } else { 97 /* hint_information */ 98 if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER && 99 ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) { 100 clu_offset -= ei->hint_bmap.off; 101 clu.dir = ei->hint_bmap.clu; 102 } 103 104 while (clu_offset > 0) { 105 if (exfat_get_next_cluster(sb, &(clu.dir))) 106 return -EIO; 107 108 clu_offset--; 109 } 110 } 111 112 while (clu.dir != EXFAT_EOF_CLUSTER) { 113 i = dentry & (dentries_per_clu - 1); 114 115 for ( ; i < dentries_per_clu; i++, dentry++) { 116 ep = exfat_get_dentry(sb, &clu, i, &bh, §or); 117 if (!ep) 118 return -EIO; 119 120 type = exfat_get_entry_type(ep); 121 if (type == TYPE_UNUSED) { 122 brelse(bh); 123 break; 124 } 125 126 if (type != TYPE_FILE && type != TYPE_DIR) { 127 brelse(bh); 128 continue; 129 } 130 131 num_ext = ep->dentry.file.num_ext; 132 dir_entry->attr = le16_to_cpu(ep->dentry.file.attr); 133 exfat_get_entry_time(sbi, &dir_entry->crtime, 134 ep->dentry.file.create_tz, 135 ep->dentry.file.create_time, 136 ep->dentry.file.create_date, 137 ep->dentry.file.create_time_cs); 138 exfat_get_entry_time(sbi, &dir_entry->mtime, 139 ep->dentry.file.modify_tz, 140 ep->dentry.file.modify_time, 141 ep->dentry.file.modify_date, 142 ep->dentry.file.modify_time_cs); 143 exfat_get_entry_time(sbi, &dir_entry->atime, 144 ep->dentry.file.access_tz, 145 ep->dentry.file.access_time, 146 ep->dentry.file.access_date, 147 0); 148 149 *uni_name.name = 0x0; 150 exfat_get_uniname_from_ext_entry(sb, &dir, dentry, 151 uni_name.name); 152 exfat_utf16_to_nls(sb, &uni_name, 153 dir_entry->namebuf.lfn, 154 dir_entry->namebuf.lfnbuf_len); 155 brelse(bh); 156 157 ep = exfat_get_dentry(sb, &clu, i + 1, &bh, NULL); 158 if (!ep) 159 return -EIO; 160 dir_entry->size = 161 le64_to_cpu(ep->dentry.stream.valid_size); 162 dir_entry->entry = dentry; 163 brelse(bh); 164 165 ei->hint_bmap.off = dentry >> dentries_per_clu_bits; 166 ei->hint_bmap.clu = clu.dir; 167 168 *cpos = EXFAT_DEN_TO_B(dentry + 1 + num_ext); 169 return 0; 170 } 171 172 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 173 if (--clu.size > 0) 174 clu.dir++; 175 else 176 clu.dir = EXFAT_EOF_CLUSTER; 177 } else { 178 if (exfat_get_next_cluster(sb, &(clu.dir))) 179 return -EIO; 180 } 181 } 182 183 dir_entry->namebuf.lfn[0] = '\0'; 184 *cpos = EXFAT_DEN_TO_B(dentry); 185 return 0; 186 } 187 188 static void exfat_init_namebuf(struct exfat_dentry_namebuf *nb) 189 { 190 nb->lfn = NULL; 191 nb->lfnbuf_len = 0; 192 } 193 194 static int exfat_alloc_namebuf(struct exfat_dentry_namebuf *nb) 195 { 196 nb->lfn = __getname(); 197 if (!nb->lfn) 198 return -ENOMEM; 199 nb->lfnbuf_len = MAX_VFSNAME_BUF_SIZE; 200 return 0; 201 } 202 203 static void exfat_free_namebuf(struct exfat_dentry_namebuf *nb) 204 { 205 if (!nb->lfn) 206 return; 207 208 __putname(nb->lfn); 209 exfat_init_namebuf(nb); 210 } 211 212 /* skip iterating emit_dots when dir is empty */ 213 #define ITER_POS_FILLED_DOTS (2) 214 static int exfat_iterate(struct file *filp, struct dir_context *ctx) 215 { 216 struct inode *inode = filp->f_path.dentry->d_inode; 217 struct super_block *sb = inode->i_sb; 218 struct inode *tmp; 219 struct exfat_dir_entry de; 220 struct exfat_dentry_namebuf *nb = &(de.namebuf); 221 struct exfat_inode_info *ei = EXFAT_I(inode); 222 unsigned long inum; 223 loff_t cpos, i_pos; 224 int err = 0, fake_offset = 0; 225 226 exfat_init_namebuf(nb); 227 mutex_lock(&EXFAT_SB(sb)->s_lock); 228 229 cpos = ctx->pos; 230 if (!dir_emit_dots(filp, ctx)) 231 goto unlock; 232 233 if (ctx->pos == ITER_POS_FILLED_DOTS) { 234 cpos = 0; 235 fake_offset = 1; 236 } 237 238 if (cpos & (DENTRY_SIZE - 1)) { 239 err = -ENOENT; 240 goto unlock; 241 } 242 243 /* name buffer should be allocated before use */ 244 err = exfat_alloc_namebuf(nb); 245 if (err) 246 goto unlock; 247 get_new: 248 if (cpos >= i_size_read(inode)) 249 goto end_of_dir; 250 251 err = exfat_readdir(inode, &cpos, &de); 252 if (err) { 253 /* 254 * At least we tried to read a sector. Move cpos to next sector 255 * position (should be aligned). 256 */ 257 if (err == -EIO) { 258 cpos += 1 << (sb->s_blocksize_bits); 259 cpos &= ~(sb->s_blocksize - 1); 260 } 261 262 err = -EIO; 263 goto end_of_dir; 264 } 265 266 if (!nb->lfn[0]) 267 goto end_of_dir; 268 269 i_pos = ((loff_t)ei->start_clu << 32) | (de.entry & 0xffffffff); 270 tmp = exfat_iget(sb, i_pos); 271 if (tmp) { 272 inum = tmp->i_ino; 273 iput(tmp); 274 } else { 275 inum = iunique(sb, EXFAT_ROOT_INO); 276 } 277 278 /* 279 * Before calling dir_emit(), sb_lock should be released. 280 * Because page fault can occur in dir_emit() when the size 281 * of buffer given from user is larger than one page size. 282 */ 283 mutex_unlock(&EXFAT_SB(sb)->s_lock); 284 if (!dir_emit(ctx, nb->lfn, strlen(nb->lfn), inum, 285 (de.attr & ATTR_SUBDIR) ? DT_DIR : DT_REG)) 286 goto out_unlocked; 287 mutex_lock(&EXFAT_SB(sb)->s_lock); 288 ctx->pos = cpos; 289 goto get_new; 290 291 end_of_dir: 292 if (!cpos && fake_offset) 293 cpos = ITER_POS_FILLED_DOTS; 294 ctx->pos = cpos; 295 unlock: 296 mutex_unlock(&EXFAT_SB(sb)->s_lock); 297 out_unlocked: 298 /* 299 * To improve performance, free namebuf after unlock sb_lock. 300 * If namebuf is not allocated, this function do nothing 301 */ 302 exfat_free_namebuf(nb); 303 return err; 304 } 305 306 const struct file_operations exfat_dir_operations = { 307 .llseek = generic_file_llseek, 308 .read = generic_read_dir, 309 .iterate = exfat_iterate, 310 .unlocked_ioctl = exfat_ioctl, 311 #ifdef CONFIG_COMPAT 312 .compat_ioctl = exfat_compat_ioctl, 313 #endif 314 .fsync = exfat_file_fsync, 315 }; 316 317 int exfat_alloc_new_dir(struct inode *inode, struct exfat_chain *clu) 318 { 319 int ret; 320 321 exfat_chain_set(clu, EXFAT_EOF_CLUSTER, 0, ALLOC_NO_FAT_CHAIN); 322 323 ret = exfat_alloc_cluster(inode, 1, clu); 324 if (ret) 325 return ret; 326 327 return exfat_zeroed_cluster(inode, clu->dir); 328 } 329 330 int exfat_calc_num_entries(struct exfat_uni_name *p_uniname) 331 { 332 int len; 333 334 len = p_uniname->name_len; 335 if (len == 0) 336 return -EINVAL; 337 338 /* 1 file entry + 1 stream entry + name entries */ 339 return ((len - 1) / EXFAT_FILE_NAME_LEN + 3); 340 } 341 342 unsigned int exfat_get_entry_type(struct exfat_dentry *ep) 343 { 344 if (ep->type == EXFAT_UNUSED) 345 return TYPE_UNUSED; 346 if (IS_EXFAT_DELETED(ep->type)) 347 return TYPE_DELETED; 348 if (ep->type == EXFAT_INVAL) 349 return TYPE_INVALID; 350 if (IS_EXFAT_CRITICAL_PRI(ep->type)) { 351 if (ep->type == EXFAT_BITMAP) 352 return TYPE_BITMAP; 353 if (ep->type == EXFAT_UPCASE) 354 return TYPE_UPCASE; 355 if (ep->type == EXFAT_VOLUME) 356 return TYPE_VOLUME; 357 if (ep->type == EXFAT_FILE) { 358 if (le16_to_cpu(ep->dentry.file.attr) & ATTR_SUBDIR) 359 return TYPE_DIR; 360 return TYPE_FILE; 361 } 362 return TYPE_CRITICAL_PRI; 363 } 364 if (IS_EXFAT_BENIGN_PRI(ep->type)) { 365 if (ep->type == EXFAT_GUID) 366 return TYPE_GUID; 367 if (ep->type == EXFAT_PADDING) 368 return TYPE_PADDING; 369 if (ep->type == EXFAT_ACLTAB) 370 return TYPE_ACLTAB; 371 return TYPE_BENIGN_PRI; 372 } 373 if (IS_EXFAT_CRITICAL_SEC(ep->type)) { 374 if (ep->type == EXFAT_STREAM) 375 return TYPE_STREAM; 376 if (ep->type == EXFAT_NAME) 377 return TYPE_EXTEND; 378 if (ep->type == EXFAT_ACL) 379 return TYPE_ACL; 380 return TYPE_CRITICAL_SEC; 381 } 382 return TYPE_BENIGN_SEC; 383 } 384 385 static void exfat_set_entry_type(struct exfat_dentry *ep, unsigned int type) 386 { 387 if (type == TYPE_UNUSED) { 388 ep->type = EXFAT_UNUSED; 389 } else if (type == TYPE_DELETED) { 390 ep->type &= EXFAT_DELETE; 391 } else if (type == TYPE_STREAM) { 392 ep->type = EXFAT_STREAM; 393 } else if (type == TYPE_EXTEND) { 394 ep->type = EXFAT_NAME; 395 } else if (type == TYPE_BITMAP) { 396 ep->type = EXFAT_BITMAP; 397 } else if (type == TYPE_UPCASE) { 398 ep->type = EXFAT_UPCASE; 399 } else if (type == TYPE_VOLUME) { 400 ep->type = EXFAT_VOLUME; 401 } else if (type == TYPE_DIR) { 402 ep->type = EXFAT_FILE; 403 ep->dentry.file.attr = cpu_to_le16(ATTR_SUBDIR); 404 } else if (type == TYPE_FILE) { 405 ep->type = EXFAT_FILE; 406 ep->dentry.file.attr = cpu_to_le16(ATTR_ARCHIVE); 407 } 408 } 409 410 static void exfat_init_stream_entry(struct exfat_dentry *ep, 411 unsigned char flags, unsigned int start_clu, 412 unsigned long long size) 413 { 414 exfat_set_entry_type(ep, TYPE_STREAM); 415 ep->dentry.stream.flags = flags; 416 ep->dentry.stream.start_clu = cpu_to_le32(start_clu); 417 ep->dentry.stream.valid_size = cpu_to_le64(size); 418 ep->dentry.stream.size = cpu_to_le64(size); 419 } 420 421 static void exfat_init_name_entry(struct exfat_dentry *ep, 422 unsigned short *uniname) 423 { 424 int i; 425 426 exfat_set_entry_type(ep, TYPE_EXTEND); 427 ep->dentry.name.flags = 0x0; 428 429 for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) { 430 if (*uniname != 0x0) { 431 ep->dentry.name.unicode_0_14[i] = cpu_to_le16(*uniname); 432 uniname++; 433 } else { 434 ep->dentry.name.unicode_0_14[i] = 0x0; 435 } 436 } 437 } 438 439 int exfat_init_dir_entry(struct inode *inode, struct exfat_chain *p_dir, 440 int entry, unsigned int type, unsigned int start_clu, 441 unsigned long long size) 442 { 443 struct super_block *sb = inode->i_sb; 444 struct exfat_sb_info *sbi = EXFAT_SB(sb); 445 struct timespec64 ts = current_time(inode); 446 sector_t sector; 447 struct exfat_dentry *ep; 448 struct buffer_head *bh; 449 450 /* 451 * We cannot use exfat_get_dentry_set here because file ep is not 452 * initialized yet. 453 */ 454 ep = exfat_get_dentry(sb, p_dir, entry, &bh, §or); 455 if (!ep) 456 return -EIO; 457 458 exfat_set_entry_type(ep, type); 459 exfat_set_entry_time(sbi, &ts, 460 &ep->dentry.file.create_tz, 461 &ep->dentry.file.create_time, 462 &ep->dentry.file.create_date, 463 &ep->dentry.file.create_time_cs); 464 exfat_set_entry_time(sbi, &ts, 465 &ep->dentry.file.modify_tz, 466 &ep->dentry.file.modify_time, 467 &ep->dentry.file.modify_date, 468 &ep->dentry.file.modify_time_cs); 469 exfat_set_entry_time(sbi, &ts, 470 &ep->dentry.file.access_tz, 471 &ep->dentry.file.access_time, 472 &ep->dentry.file.access_date, 473 NULL); 474 475 exfat_update_bh(bh, IS_DIRSYNC(inode)); 476 brelse(bh); 477 478 ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh, §or); 479 if (!ep) 480 return -EIO; 481 482 exfat_init_stream_entry(ep, 483 (type == TYPE_FILE) ? ALLOC_FAT_CHAIN : ALLOC_NO_FAT_CHAIN, 484 start_clu, size); 485 exfat_update_bh(bh, IS_DIRSYNC(inode)); 486 brelse(bh); 487 488 return 0; 489 } 490 491 int exfat_update_dir_chksum(struct inode *inode, struct exfat_chain *p_dir, 492 int entry) 493 { 494 struct super_block *sb = inode->i_sb; 495 int ret = 0; 496 int i, num_entries; 497 sector_t sector; 498 u16 chksum; 499 struct exfat_dentry *ep, *fep; 500 struct buffer_head *fbh, *bh; 501 502 fep = exfat_get_dentry(sb, p_dir, entry, &fbh, §or); 503 if (!fep) 504 return -EIO; 505 506 num_entries = fep->dentry.file.num_ext + 1; 507 chksum = exfat_calc_chksum16(fep, DENTRY_SIZE, 0, CS_DIR_ENTRY); 508 509 for (i = 1; i < num_entries; i++) { 510 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh, NULL); 511 if (!ep) { 512 ret = -EIO; 513 goto release_fbh; 514 } 515 chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum, 516 CS_DEFAULT); 517 brelse(bh); 518 } 519 520 fep->dentry.file.checksum = cpu_to_le16(chksum); 521 exfat_update_bh(fbh, IS_DIRSYNC(inode)); 522 release_fbh: 523 brelse(fbh); 524 return ret; 525 } 526 527 int exfat_init_ext_entry(struct inode *inode, struct exfat_chain *p_dir, 528 int entry, int num_entries, struct exfat_uni_name *p_uniname) 529 { 530 struct super_block *sb = inode->i_sb; 531 int i; 532 sector_t sector; 533 unsigned short *uniname = p_uniname->name; 534 struct exfat_dentry *ep; 535 struct buffer_head *bh; 536 int sync = IS_DIRSYNC(inode); 537 538 ep = exfat_get_dentry(sb, p_dir, entry, &bh, §or); 539 if (!ep) 540 return -EIO; 541 542 ep->dentry.file.num_ext = (unsigned char)(num_entries - 1); 543 exfat_update_bh(bh, sync); 544 brelse(bh); 545 546 ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh, §or); 547 if (!ep) 548 return -EIO; 549 550 ep->dentry.stream.name_len = p_uniname->name_len; 551 ep->dentry.stream.name_hash = cpu_to_le16(p_uniname->name_hash); 552 exfat_update_bh(bh, sync); 553 brelse(bh); 554 555 for (i = EXFAT_FIRST_CLUSTER; i < num_entries; i++) { 556 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh, §or); 557 if (!ep) 558 return -EIO; 559 560 exfat_init_name_entry(ep, uniname); 561 exfat_update_bh(bh, sync); 562 brelse(bh); 563 uniname += EXFAT_FILE_NAME_LEN; 564 } 565 566 exfat_update_dir_chksum(inode, p_dir, entry); 567 return 0; 568 } 569 570 int exfat_remove_entries(struct inode *inode, struct exfat_chain *p_dir, 571 int entry, int order, int num_entries) 572 { 573 struct super_block *sb = inode->i_sb; 574 int i; 575 sector_t sector; 576 struct exfat_dentry *ep; 577 struct buffer_head *bh; 578 579 for (i = order; i < num_entries; i++) { 580 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh, §or); 581 if (!ep) 582 return -EIO; 583 584 exfat_set_entry_type(ep, TYPE_DELETED); 585 exfat_update_bh(bh, IS_DIRSYNC(inode)); 586 brelse(bh); 587 } 588 589 return 0; 590 } 591 592 void exfat_update_dir_chksum_with_entry_set(struct exfat_entry_set_cache *es) 593 { 594 int chksum_type = CS_DIR_ENTRY, i; 595 unsigned short chksum = 0; 596 struct exfat_dentry *ep; 597 598 for (i = 0; i < es->num_entries; i++) { 599 ep = exfat_get_dentry_cached(es, i); 600 chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum, 601 chksum_type); 602 chksum_type = CS_DEFAULT; 603 } 604 ep = exfat_get_dentry_cached(es, 0); 605 ep->dentry.file.checksum = cpu_to_le16(chksum); 606 es->modified = true; 607 } 608 609 int exfat_free_dentry_set(struct exfat_entry_set_cache *es, int sync) 610 { 611 int i, err = 0; 612 613 if (es->modified) 614 err = exfat_update_bhs(es->bh, es->num_bh, sync); 615 616 for (i = 0; i < es->num_bh; i++) 617 if (err) 618 bforget(es->bh[i]); 619 else 620 brelse(es->bh[i]); 621 kfree(es); 622 return err; 623 } 624 625 static int exfat_walk_fat_chain(struct super_block *sb, 626 struct exfat_chain *p_dir, unsigned int byte_offset, 627 unsigned int *clu) 628 { 629 struct exfat_sb_info *sbi = EXFAT_SB(sb); 630 unsigned int clu_offset; 631 unsigned int cur_clu; 632 633 clu_offset = EXFAT_B_TO_CLU(byte_offset, sbi); 634 cur_clu = p_dir->dir; 635 636 if (p_dir->flags == ALLOC_NO_FAT_CHAIN) { 637 cur_clu += clu_offset; 638 } else { 639 while (clu_offset > 0) { 640 if (exfat_get_next_cluster(sb, &cur_clu)) 641 return -EIO; 642 if (cur_clu == EXFAT_EOF_CLUSTER) { 643 exfat_fs_error(sb, 644 "invalid dentry access beyond EOF (clu : %u, eidx : %d)", 645 p_dir->dir, 646 EXFAT_B_TO_DEN(byte_offset)); 647 return -EIO; 648 } 649 clu_offset--; 650 } 651 } 652 653 *clu = cur_clu; 654 return 0; 655 } 656 657 int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir, 658 int entry, sector_t *sector, int *offset) 659 { 660 int ret; 661 unsigned int off, clu = 0; 662 struct exfat_sb_info *sbi = EXFAT_SB(sb); 663 664 off = EXFAT_DEN_TO_B(entry); 665 666 ret = exfat_walk_fat_chain(sb, p_dir, off, &clu); 667 if (ret) 668 return ret; 669 670 /* byte offset in cluster */ 671 off = EXFAT_CLU_OFFSET(off, sbi); 672 673 /* byte offset in sector */ 674 *offset = EXFAT_BLK_OFFSET(off, sb); 675 676 /* sector offset in cluster */ 677 *sector = EXFAT_B_TO_BLK(off, sb); 678 *sector += exfat_cluster_to_sector(sbi, clu); 679 return 0; 680 } 681 682 #define EXFAT_MAX_RA_SIZE (128*1024) 683 static int exfat_dir_readahead(struct super_block *sb, sector_t sec) 684 { 685 struct exfat_sb_info *sbi = EXFAT_SB(sb); 686 struct buffer_head *bh; 687 unsigned int max_ra_count = EXFAT_MAX_RA_SIZE >> sb->s_blocksize_bits; 688 unsigned int page_ra_count = PAGE_SIZE >> sb->s_blocksize_bits; 689 unsigned int adj_ra_count = max(sbi->sect_per_clus, page_ra_count); 690 unsigned int ra_count = min(adj_ra_count, max_ra_count); 691 692 /* Read-ahead is not required */ 693 if (sbi->sect_per_clus == 1) 694 return 0; 695 696 if (sec < sbi->data_start_sector) { 697 exfat_err(sb, "requested sector is invalid(sect:%llu, root:%llu)", 698 (unsigned long long)sec, sbi->data_start_sector); 699 return -EIO; 700 } 701 702 /* Not sector aligned with ra_count, resize ra_count to page size */ 703 if ((sec - sbi->data_start_sector) & (ra_count - 1)) 704 ra_count = page_ra_count; 705 706 bh = sb_find_get_block(sb, sec); 707 if (!bh || !buffer_uptodate(bh)) { 708 unsigned int i; 709 710 for (i = 0; i < ra_count; i++) 711 sb_breadahead(sb, (sector_t)(sec + i)); 712 } 713 brelse(bh); 714 return 0; 715 } 716 717 struct exfat_dentry *exfat_get_dentry(struct super_block *sb, 718 struct exfat_chain *p_dir, int entry, struct buffer_head **bh, 719 sector_t *sector) 720 { 721 unsigned int dentries_per_page = EXFAT_B_TO_DEN(PAGE_SIZE); 722 int off; 723 sector_t sec; 724 725 if (p_dir->dir == DIR_DELETED) { 726 exfat_err(sb, "abnormal access to deleted dentry"); 727 return NULL; 728 } 729 730 if (exfat_find_location(sb, p_dir, entry, &sec, &off)) 731 return NULL; 732 733 if (p_dir->dir != EXFAT_FREE_CLUSTER && 734 !(entry & (dentries_per_page - 1))) 735 exfat_dir_readahead(sb, sec); 736 737 *bh = sb_bread(sb, sec); 738 if (!*bh) 739 return NULL; 740 741 if (sector) 742 *sector = sec; 743 return (struct exfat_dentry *)((*bh)->b_data + off); 744 } 745 746 enum exfat_validate_dentry_mode { 747 ES_MODE_STARTED, 748 ES_MODE_GET_FILE_ENTRY, 749 ES_MODE_GET_STRM_ENTRY, 750 ES_MODE_GET_NAME_ENTRY, 751 ES_MODE_GET_CRITICAL_SEC_ENTRY, 752 }; 753 754 static bool exfat_validate_entry(unsigned int type, 755 enum exfat_validate_dentry_mode *mode) 756 { 757 if (type == TYPE_UNUSED || type == TYPE_DELETED) 758 return false; 759 760 switch (*mode) { 761 case ES_MODE_STARTED: 762 if (type != TYPE_FILE && type != TYPE_DIR) 763 return false; 764 *mode = ES_MODE_GET_FILE_ENTRY; 765 return true; 766 case ES_MODE_GET_FILE_ENTRY: 767 if (type != TYPE_STREAM) 768 return false; 769 *mode = ES_MODE_GET_STRM_ENTRY; 770 return true; 771 case ES_MODE_GET_STRM_ENTRY: 772 if (type != TYPE_EXTEND) 773 return false; 774 *mode = ES_MODE_GET_NAME_ENTRY; 775 return true; 776 case ES_MODE_GET_NAME_ENTRY: 777 if (type == TYPE_STREAM) 778 return false; 779 if (type != TYPE_EXTEND) { 780 if (!(type & TYPE_CRITICAL_SEC)) 781 return false; 782 *mode = ES_MODE_GET_CRITICAL_SEC_ENTRY; 783 } 784 return true; 785 case ES_MODE_GET_CRITICAL_SEC_ENTRY: 786 if (type == TYPE_EXTEND || type == TYPE_STREAM) 787 return false; 788 if ((type & TYPE_CRITICAL_SEC) != TYPE_CRITICAL_SEC) 789 return false; 790 return true; 791 default: 792 WARN_ON_ONCE(1); 793 return false; 794 } 795 } 796 797 struct exfat_dentry *exfat_get_dentry_cached( 798 struct exfat_entry_set_cache *es, int num) 799 { 800 int off = es->start_off + num * DENTRY_SIZE; 801 struct buffer_head *bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)]; 802 char *p = bh->b_data + EXFAT_BLK_OFFSET(off, es->sb); 803 804 return (struct exfat_dentry *)p; 805 } 806 807 /* 808 * Returns a set of dentries for a file or dir. 809 * 810 * Note It provides a direct pointer to bh->data via exfat_get_dentry_cached(). 811 * User should call exfat_get_dentry_set() after setting 'modified' to apply 812 * changes made in this entry set to the real device. 813 * 814 * in: 815 * sb+p_dir+entry: indicates a file/dir 816 * type: specifies how many dentries should be included. 817 * return: 818 * pointer of entry set on success, 819 * NULL on failure. 820 */ 821 struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb, 822 struct exfat_chain *p_dir, int entry, unsigned int type) 823 { 824 int ret, i, num_bh; 825 unsigned int off, byte_offset, clu = 0; 826 sector_t sec; 827 struct exfat_sb_info *sbi = EXFAT_SB(sb); 828 struct exfat_entry_set_cache *es; 829 struct exfat_dentry *ep; 830 int num_entries; 831 enum exfat_validate_dentry_mode mode = ES_MODE_STARTED; 832 struct buffer_head *bh; 833 834 if (p_dir->dir == DIR_DELETED) { 835 exfat_err(sb, "access to deleted dentry"); 836 return NULL; 837 } 838 839 byte_offset = EXFAT_DEN_TO_B(entry); 840 ret = exfat_walk_fat_chain(sb, p_dir, byte_offset, &clu); 841 if (ret) 842 return NULL; 843 844 es = kzalloc(sizeof(*es), GFP_KERNEL); 845 if (!es) 846 return NULL; 847 es->sb = sb; 848 es->modified = false; 849 850 /* byte offset in cluster */ 851 byte_offset = EXFAT_CLU_OFFSET(byte_offset, sbi); 852 853 /* byte offset in sector */ 854 off = EXFAT_BLK_OFFSET(byte_offset, sb); 855 es->start_off = off; 856 857 /* sector offset in cluster */ 858 sec = EXFAT_B_TO_BLK(byte_offset, sb); 859 sec += exfat_cluster_to_sector(sbi, clu); 860 861 bh = sb_bread(sb, sec); 862 if (!bh) 863 goto free_es; 864 es->bh[es->num_bh++] = bh; 865 866 ep = exfat_get_dentry_cached(es, 0); 867 if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode)) 868 goto free_es; 869 870 num_entries = type == ES_ALL_ENTRIES ? 871 ep->dentry.file.num_ext + 1 : type; 872 es->num_entries = num_entries; 873 874 num_bh = EXFAT_B_TO_BLK_ROUND_UP(off + num_entries * DENTRY_SIZE, sb); 875 for (i = 1; i < num_bh; i++) { 876 /* get the next sector */ 877 if (exfat_is_last_sector_in_cluster(sbi, sec)) { 878 if (p_dir->flags == ALLOC_NO_FAT_CHAIN) 879 clu++; 880 else if (exfat_get_next_cluster(sb, &clu)) 881 goto free_es; 882 sec = exfat_cluster_to_sector(sbi, clu); 883 } else { 884 sec++; 885 } 886 887 bh = sb_bread(sb, sec); 888 if (!bh) 889 goto free_es; 890 es->bh[es->num_bh++] = bh; 891 } 892 893 /* validiate cached dentries */ 894 for (i = 1; i < num_entries; i++) { 895 ep = exfat_get_dentry_cached(es, i); 896 if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode)) 897 goto free_es; 898 } 899 return es; 900 901 free_es: 902 exfat_free_dentry_set(es, false); 903 return NULL; 904 } 905 906 enum { 907 DIRENT_STEP_FILE, 908 DIRENT_STEP_STRM, 909 DIRENT_STEP_NAME, 910 DIRENT_STEP_SECD, 911 }; 912 913 /* 914 * return values: 915 * >= 0 : return dir entiry position with the name in dir 916 * -ENOENT : entry with the name does not exist 917 * -EIO : I/O error 918 */ 919 int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei, 920 struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname, 921 int num_entries, unsigned int type) 922 { 923 int i, rewind = 0, dentry = 0, end_eidx = 0, num_ext = 0, len; 924 int order, step, name_len = 0; 925 int dentries_per_clu, num_empty = 0; 926 unsigned int entry_type; 927 unsigned short *uniname = NULL; 928 struct exfat_chain clu; 929 struct exfat_hint *hint_stat = &ei->hint_stat; 930 struct exfat_hint_femp candi_empty; 931 struct exfat_sb_info *sbi = EXFAT_SB(sb); 932 933 dentries_per_clu = sbi->dentries_per_clu; 934 935 exfat_chain_dup(&clu, p_dir); 936 937 if (hint_stat->eidx) { 938 clu.dir = hint_stat->clu; 939 dentry = hint_stat->eidx; 940 end_eidx = dentry; 941 } 942 943 candi_empty.eidx = EXFAT_HINT_NONE; 944 rewind: 945 order = 0; 946 step = DIRENT_STEP_FILE; 947 while (clu.dir != EXFAT_EOF_CLUSTER) { 948 i = dentry & (dentries_per_clu - 1); 949 for (; i < dentries_per_clu; i++, dentry++) { 950 struct exfat_dentry *ep; 951 struct buffer_head *bh; 952 953 if (rewind && dentry == end_eidx) 954 goto not_found; 955 956 ep = exfat_get_dentry(sb, &clu, i, &bh, NULL); 957 if (!ep) 958 return -EIO; 959 960 entry_type = exfat_get_entry_type(ep); 961 962 if (entry_type == TYPE_UNUSED || 963 entry_type == TYPE_DELETED) { 964 step = DIRENT_STEP_FILE; 965 966 num_empty++; 967 if (candi_empty.eidx == EXFAT_HINT_NONE && 968 num_empty == 1) { 969 exfat_chain_set(&candi_empty.cur, 970 clu.dir, clu.size, clu.flags); 971 } 972 973 if (candi_empty.eidx == EXFAT_HINT_NONE && 974 num_empty >= num_entries) { 975 candi_empty.eidx = 976 dentry - (num_empty - 1); 977 WARN_ON(candi_empty.eidx < 0); 978 candi_empty.count = num_empty; 979 980 if (ei->hint_femp.eidx == 981 EXFAT_HINT_NONE || 982 candi_empty.eidx <= 983 ei->hint_femp.eidx) 984 ei->hint_femp = candi_empty; 985 } 986 987 brelse(bh); 988 if (entry_type == TYPE_UNUSED) 989 goto not_found; 990 continue; 991 } 992 993 num_empty = 0; 994 candi_empty.eidx = EXFAT_HINT_NONE; 995 996 if (entry_type == TYPE_FILE || entry_type == TYPE_DIR) { 997 step = DIRENT_STEP_FILE; 998 if (type == TYPE_ALL || type == entry_type) { 999 num_ext = ep->dentry.file.num_ext; 1000 step = DIRENT_STEP_STRM; 1001 } 1002 brelse(bh); 1003 continue; 1004 } 1005 1006 if (entry_type == TYPE_STREAM) { 1007 u16 name_hash; 1008 1009 if (step != DIRENT_STEP_STRM) { 1010 step = DIRENT_STEP_FILE; 1011 brelse(bh); 1012 continue; 1013 } 1014 step = DIRENT_STEP_FILE; 1015 name_hash = le16_to_cpu( 1016 ep->dentry.stream.name_hash); 1017 if (p_uniname->name_hash == name_hash && 1018 p_uniname->name_len == 1019 ep->dentry.stream.name_len) { 1020 step = DIRENT_STEP_NAME; 1021 order = 1; 1022 name_len = 0; 1023 } 1024 brelse(bh); 1025 continue; 1026 } 1027 1028 brelse(bh); 1029 if (entry_type == TYPE_EXTEND) { 1030 unsigned short entry_uniname[16], unichar; 1031 1032 if (step != DIRENT_STEP_NAME) { 1033 step = DIRENT_STEP_FILE; 1034 continue; 1035 } 1036 1037 if (++order == 2) 1038 uniname = p_uniname->name; 1039 else 1040 uniname += EXFAT_FILE_NAME_LEN; 1041 1042 len = exfat_extract_uni_name(ep, entry_uniname); 1043 name_len += len; 1044 1045 unichar = *(uniname+len); 1046 *(uniname+len) = 0x0; 1047 1048 if (exfat_uniname_ncmp(sb, uniname, 1049 entry_uniname, len)) { 1050 step = DIRENT_STEP_FILE; 1051 } else if (p_uniname->name_len == name_len) { 1052 if (order == num_ext) 1053 goto found; 1054 step = DIRENT_STEP_SECD; 1055 } 1056 1057 *(uniname+len) = unichar; 1058 continue; 1059 } 1060 1061 if (entry_type & 1062 (TYPE_CRITICAL_SEC | TYPE_BENIGN_SEC)) { 1063 if (step == DIRENT_STEP_SECD) { 1064 if (++order == num_ext) 1065 goto found; 1066 continue; 1067 } 1068 } 1069 step = DIRENT_STEP_FILE; 1070 } 1071 1072 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1073 if (--clu.size > 0) 1074 clu.dir++; 1075 else 1076 clu.dir = EXFAT_EOF_CLUSTER; 1077 } else { 1078 if (exfat_get_next_cluster(sb, &clu.dir)) 1079 return -EIO; 1080 } 1081 } 1082 1083 not_found: 1084 /* 1085 * We started at not 0 index,so we should try to find target 1086 * from 0 index to the index we started at. 1087 */ 1088 if (!rewind && end_eidx) { 1089 rewind = 1; 1090 dentry = 0; 1091 clu.dir = p_dir->dir; 1092 /* reset empty hint */ 1093 num_empty = 0; 1094 candi_empty.eidx = EXFAT_HINT_NONE; 1095 goto rewind; 1096 } 1097 1098 /* initialized hint_stat */ 1099 hint_stat->clu = p_dir->dir; 1100 hint_stat->eidx = 0; 1101 return -ENOENT; 1102 1103 found: 1104 /* next dentry we'll find is out of this cluster */ 1105 if (!((dentry + 1) & (dentries_per_clu - 1))) { 1106 int ret = 0; 1107 1108 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1109 if (--clu.size > 0) 1110 clu.dir++; 1111 else 1112 clu.dir = EXFAT_EOF_CLUSTER; 1113 } else { 1114 ret = exfat_get_next_cluster(sb, &clu.dir); 1115 } 1116 1117 if (ret || clu.dir == EXFAT_EOF_CLUSTER) { 1118 /* just initialized hint_stat */ 1119 hint_stat->clu = p_dir->dir; 1120 hint_stat->eidx = 0; 1121 return (dentry - num_ext); 1122 } 1123 } 1124 1125 hint_stat->clu = clu.dir; 1126 hint_stat->eidx = dentry + 1; 1127 return dentry - num_ext; 1128 } 1129 1130 int exfat_count_ext_entries(struct super_block *sb, struct exfat_chain *p_dir, 1131 int entry, struct exfat_dentry *ep) 1132 { 1133 int i, count = 0; 1134 unsigned int type; 1135 struct exfat_dentry *ext_ep; 1136 struct buffer_head *bh; 1137 1138 for (i = 0, entry++; i < ep->dentry.file.num_ext; i++, entry++) { 1139 ext_ep = exfat_get_dentry(sb, p_dir, entry, &bh, NULL); 1140 if (!ext_ep) 1141 return -EIO; 1142 1143 type = exfat_get_entry_type(ext_ep); 1144 brelse(bh); 1145 if (type == TYPE_EXTEND || type == TYPE_STREAM) 1146 count++; 1147 else 1148 break; 1149 } 1150 return count; 1151 } 1152 1153 int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir) 1154 { 1155 int i, count = 0; 1156 int dentries_per_clu; 1157 unsigned int entry_type; 1158 struct exfat_chain clu; 1159 struct exfat_dentry *ep; 1160 struct exfat_sb_info *sbi = EXFAT_SB(sb); 1161 struct buffer_head *bh; 1162 1163 dentries_per_clu = sbi->dentries_per_clu; 1164 1165 exfat_chain_dup(&clu, p_dir); 1166 1167 while (clu.dir != EXFAT_EOF_CLUSTER) { 1168 for (i = 0; i < dentries_per_clu; i++) { 1169 ep = exfat_get_dentry(sb, &clu, i, &bh, NULL); 1170 if (!ep) 1171 return -EIO; 1172 entry_type = exfat_get_entry_type(ep); 1173 brelse(bh); 1174 1175 if (entry_type == TYPE_UNUSED) 1176 return count; 1177 if (entry_type != TYPE_DIR) 1178 continue; 1179 count++; 1180 } 1181 1182 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1183 if (--clu.size > 0) 1184 clu.dir++; 1185 else 1186 clu.dir = EXFAT_EOF_CLUSTER; 1187 } else { 1188 if (exfat_get_next_cluster(sb, &(clu.dir))) 1189 return -EIO; 1190 } 1191 } 1192 1193 return count; 1194 } 1195