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 if (exfat_get_dentry_set(&es, sb, p_dir, entry, ES_ALL_ENTRIES)) 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_put_dentry_set(&es, false); 59 } 60 61 /* read a directory entry from the opened directory */ 62 static int exfat_readdir(struct inode *inode, loff_t *cpos, struct exfat_dir_entry *dir_entry) 63 { 64 int i, dentries_per_clu, dentries_per_clu_bits = 0, num_ext; 65 unsigned int type, clu_offset, max_dentries; 66 struct exfat_chain dir, clu; 67 struct exfat_uni_name uni_name; 68 struct exfat_dentry *ep; 69 struct super_block *sb = inode->i_sb; 70 struct exfat_sb_info *sbi = EXFAT_SB(sb); 71 struct exfat_inode_info *ei = EXFAT_I(inode); 72 unsigned int dentry = EXFAT_B_TO_DEN(*cpos) & 0xFFFFFFFF; 73 struct buffer_head *bh; 74 75 /* check if the given file ID is opened */ 76 if (ei->type != TYPE_DIR) 77 return -EPERM; 78 79 if (ei->entry == -1) 80 exfat_chain_set(&dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN); 81 else 82 exfat_chain_set(&dir, ei->start_clu, 83 EXFAT_B_TO_CLU(i_size_read(inode), sbi), ei->flags); 84 85 dentries_per_clu = sbi->dentries_per_clu; 86 dentries_per_clu_bits = ilog2(dentries_per_clu); 87 max_dentries = (unsigned int)min_t(u64, MAX_EXFAT_DENTRIES, 88 (u64)sbi->num_clusters << dentries_per_clu_bits); 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 && dentry < max_dentries) { 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); 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, &clu, i, 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); 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 *file, struct dir_context *ctx) 215 { 216 struct inode *inode = file_inode(file); 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(file, 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 (ei->flags == ALLOC_NO_FAT_CHAIN && 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, IS_DIRSYNC(inode)); 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 struct exfat_dentry *ep; 447 struct buffer_head *bh; 448 449 /* 450 * We cannot use exfat_get_dentry_set here because file ep is not 451 * initialized yet. 452 */ 453 ep = exfat_get_dentry(sb, p_dir, entry, &bh); 454 if (!ep) 455 return -EIO; 456 457 exfat_set_entry_type(ep, type); 458 exfat_set_entry_time(sbi, &ts, 459 &ep->dentry.file.create_tz, 460 &ep->dentry.file.create_time, 461 &ep->dentry.file.create_date, 462 &ep->dentry.file.create_time_cs); 463 exfat_set_entry_time(sbi, &ts, 464 &ep->dentry.file.modify_tz, 465 &ep->dentry.file.modify_time, 466 &ep->dentry.file.modify_date, 467 &ep->dentry.file.modify_time_cs); 468 exfat_set_entry_time(sbi, &ts, 469 &ep->dentry.file.access_tz, 470 &ep->dentry.file.access_time, 471 &ep->dentry.file.access_date, 472 NULL); 473 474 exfat_update_bh(bh, IS_DIRSYNC(inode)); 475 brelse(bh); 476 477 ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh); 478 if (!ep) 479 return -EIO; 480 481 exfat_init_stream_entry(ep, 482 (type == TYPE_FILE) ? ALLOC_FAT_CHAIN : ALLOC_NO_FAT_CHAIN, 483 start_clu, size); 484 exfat_update_bh(bh, IS_DIRSYNC(inode)); 485 brelse(bh); 486 487 return 0; 488 } 489 490 int exfat_update_dir_chksum(struct inode *inode, struct exfat_chain *p_dir, 491 int entry) 492 { 493 struct super_block *sb = inode->i_sb; 494 int ret = 0; 495 int i, num_entries; 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); 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); 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(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 unsigned short *uniname = p_uniname->name; 531 struct exfat_dentry *ep; 532 struct buffer_head *bh; 533 int sync = IS_DIRSYNC(inode); 534 535 ep = exfat_get_dentry(sb, p_dir, entry, &bh); 536 if (!ep) 537 return -EIO; 538 539 ep->dentry.file.num_ext = (unsigned char)(num_entries - 1); 540 exfat_update_bh(bh, sync); 541 brelse(bh); 542 543 ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh); 544 if (!ep) 545 return -EIO; 546 547 ep->dentry.stream.name_len = p_uniname->name_len; 548 ep->dentry.stream.name_hash = cpu_to_le16(p_uniname->name_hash); 549 exfat_update_bh(bh, sync); 550 brelse(bh); 551 552 for (i = EXFAT_FIRST_CLUSTER; i < num_entries; i++) { 553 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh); 554 if (!ep) 555 return -EIO; 556 557 exfat_init_name_entry(ep, uniname); 558 exfat_update_bh(bh, sync); 559 brelse(bh); 560 uniname += EXFAT_FILE_NAME_LEN; 561 } 562 563 exfat_update_dir_chksum(inode, p_dir, entry); 564 return 0; 565 } 566 567 int exfat_remove_entries(struct inode *inode, struct exfat_chain *p_dir, 568 int entry, int order, int num_entries) 569 { 570 struct super_block *sb = inode->i_sb; 571 int i; 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); 577 if (!ep) 578 return -EIO; 579 580 exfat_set_entry_type(ep, TYPE_DELETED); 581 exfat_update_bh(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 int exfat_put_dentry_set(struct exfat_entry_set_cache *es, int sync) 606 { 607 int i, err = 0; 608 609 if (es->modified) 610 err = exfat_update_bhs(es->bh, es->num_bh, sync); 611 612 for (i = 0; i < es->num_bh; i++) 613 if (err) 614 bforget(es->bh[i]); 615 else 616 brelse(es->bh[i]); 617 618 if (IS_DYNAMIC_ES(es)) 619 kfree(es->bh); 620 621 return err; 622 } 623 624 static int exfat_walk_fat_chain(struct super_block *sb, 625 struct exfat_chain *p_dir, unsigned int byte_offset, 626 unsigned int *clu) 627 { 628 struct exfat_sb_info *sbi = EXFAT_SB(sb); 629 unsigned int clu_offset; 630 unsigned int cur_clu; 631 632 clu_offset = EXFAT_B_TO_CLU(byte_offset, sbi); 633 cur_clu = p_dir->dir; 634 635 if (p_dir->flags == ALLOC_NO_FAT_CHAIN) { 636 cur_clu += clu_offset; 637 } else { 638 while (clu_offset > 0) { 639 if (exfat_get_next_cluster(sb, &cur_clu)) 640 return -EIO; 641 if (cur_clu == EXFAT_EOF_CLUSTER) { 642 exfat_fs_error(sb, 643 "invalid dentry access beyond EOF (clu : %u, eidx : %d)", 644 p_dir->dir, 645 EXFAT_B_TO_DEN(byte_offset)); 646 return -EIO; 647 } 648 clu_offset--; 649 } 650 } 651 652 *clu = cur_clu; 653 return 0; 654 } 655 656 static int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir, 657 int entry, sector_t *sector, int *offset) 658 { 659 int ret; 660 unsigned int off, clu = 0; 661 struct exfat_sb_info *sbi = EXFAT_SB(sb); 662 663 off = EXFAT_DEN_TO_B(entry); 664 665 ret = exfat_walk_fat_chain(sb, p_dir, off, &clu); 666 if (ret) 667 return ret; 668 669 /* byte offset in cluster */ 670 off = EXFAT_CLU_OFFSET(off, sbi); 671 672 /* byte offset in sector */ 673 *offset = EXFAT_BLK_OFFSET(off, sb); 674 675 /* sector offset in cluster */ 676 *sector = EXFAT_B_TO_BLK(off, sb); 677 *sector += exfat_cluster_to_sector(sbi, clu); 678 return 0; 679 } 680 681 #define EXFAT_MAX_RA_SIZE (128*1024) 682 static int exfat_dir_readahead(struct super_block *sb, sector_t sec) 683 { 684 struct exfat_sb_info *sbi = EXFAT_SB(sb); 685 struct buffer_head *bh; 686 unsigned int max_ra_count = EXFAT_MAX_RA_SIZE >> sb->s_blocksize_bits; 687 unsigned int page_ra_count = PAGE_SIZE >> sb->s_blocksize_bits; 688 unsigned int adj_ra_count = max(sbi->sect_per_clus, page_ra_count); 689 unsigned int ra_count = min(adj_ra_count, max_ra_count); 690 691 /* Read-ahead is not required */ 692 if (sbi->sect_per_clus == 1) 693 return 0; 694 695 if (sec < sbi->data_start_sector) { 696 exfat_err(sb, "requested sector is invalid(sect:%llu, root:%llu)", 697 (unsigned long long)sec, sbi->data_start_sector); 698 return -EIO; 699 } 700 701 /* Not sector aligned with ra_count, resize ra_count to page size */ 702 if ((sec - sbi->data_start_sector) & (ra_count - 1)) 703 ra_count = page_ra_count; 704 705 bh = sb_find_get_block(sb, sec); 706 if (!bh || !buffer_uptodate(bh)) { 707 unsigned int i; 708 709 for (i = 0; i < ra_count; i++) 710 sb_breadahead(sb, (sector_t)(sec + i)); 711 } 712 brelse(bh); 713 return 0; 714 } 715 716 struct exfat_dentry *exfat_get_dentry(struct super_block *sb, 717 struct exfat_chain *p_dir, int entry, struct buffer_head **bh) 718 { 719 unsigned int dentries_per_page = EXFAT_B_TO_DEN(PAGE_SIZE); 720 int off; 721 sector_t sec; 722 723 if (p_dir->dir == DIR_DELETED) { 724 exfat_err(sb, "abnormal access to deleted dentry"); 725 return NULL; 726 } 727 728 if (exfat_find_location(sb, p_dir, entry, &sec, &off)) 729 return NULL; 730 731 if (p_dir->dir != EXFAT_FREE_CLUSTER && 732 !(entry & (dentries_per_page - 1))) 733 exfat_dir_readahead(sb, sec); 734 735 *bh = sb_bread(sb, sec); 736 if (!*bh) 737 return NULL; 738 739 return (struct exfat_dentry *)((*bh)->b_data + off); 740 } 741 742 enum exfat_validate_dentry_mode { 743 ES_MODE_STARTED, 744 ES_MODE_GET_FILE_ENTRY, 745 ES_MODE_GET_STRM_ENTRY, 746 ES_MODE_GET_NAME_ENTRY, 747 ES_MODE_GET_CRITICAL_SEC_ENTRY, 748 }; 749 750 static bool exfat_validate_entry(unsigned int type, 751 enum exfat_validate_dentry_mode *mode) 752 { 753 if (type == TYPE_UNUSED || type == TYPE_DELETED) 754 return false; 755 756 switch (*mode) { 757 case ES_MODE_STARTED: 758 if (type != TYPE_FILE && type != TYPE_DIR) 759 return false; 760 *mode = ES_MODE_GET_FILE_ENTRY; 761 return true; 762 case ES_MODE_GET_FILE_ENTRY: 763 if (type != TYPE_STREAM) 764 return false; 765 *mode = ES_MODE_GET_STRM_ENTRY; 766 return true; 767 case ES_MODE_GET_STRM_ENTRY: 768 if (type != TYPE_EXTEND) 769 return false; 770 *mode = ES_MODE_GET_NAME_ENTRY; 771 return true; 772 case ES_MODE_GET_NAME_ENTRY: 773 if (type == TYPE_STREAM) 774 return false; 775 if (type != TYPE_EXTEND) { 776 if (!(type & TYPE_CRITICAL_SEC)) 777 return false; 778 *mode = ES_MODE_GET_CRITICAL_SEC_ENTRY; 779 } 780 return true; 781 case ES_MODE_GET_CRITICAL_SEC_ENTRY: 782 if (type == TYPE_EXTEND || type == TYPE_STREAM) 783 return false; 784 if ((type & TYPE_CRITICAL_SEC) != TYPE_CRITICAL_SEC) 785 return false; 786 return true; 787 default: 788 WARN_ON_ONCE(1); 789 return false; 790 } 791 } 792 793 struct exfat_dentry *exfat_get_dentry_cached( 794 struct exfat_entry_set_cache *es, int num) 795 { 796 int off = es->start_off + num * DENTRY_SIZE; 797 struct buffer_head *bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)]; 798 char *p = bh->b_data + EXFAT_BLK_OFFSET(off, es->sb); 799 800 return (struct exfat_dentry *)p; 801 } 802 803 /* 804 * Returns a set of dentries for a file or dir. 805 * 806 * Note It provides a direct pointer to bh->data via exfat_get_dentry_cached(). 807 * User should call exfat_get_dentry_set() after setting 'modified' to apply 808 * changes made in this entry set to the real device. 809 * 810 * in: 811 * sb+p_dir+entry: indicates a file/dir 812 * type: specifies how many dentries should be included. 813 * return: 814 * pointer of entry set on success, 815 * NULL on failure. 816 */ 817 int exfat_get_dentry_set(struct exfat_entry_set_cache *es, 818 struct super_block *sb, struct exfat_chain *p_dir, int entry, 819 unsigned int type) 820 { 821 int ret, i, num_bh; 822 unsigned int off, byte_offset, clu = 0; 823 sector_t sec; 824 struct exfat_sb_info *sbi = EXFAT_SB(sb); 825 struct exfat_dentry *ep; 826 int num_entries; 827 enum exfat_validate_dentry_mode mode = ES_MODE_STARTED; 828 struct buffer_head *bh; 829 830 if (p_dir->dir == DIR_DELETED) { 831 exfat_err(sb, "access to deleted dentry"); 832 return -EIO; 833 } 834 835 byte_offset = EXFAT_DEN_TO_B(entry); 836 ret = exfat_walk_fat_chain(sb, p_dir, byte_offset, &clu); 837 if (ret) 838 return ret; 839 840 memset(es, 0, sizeof(*es)); 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 es->bh = es->__bh; 851 852 /* sector offset in cluster */ 853 sec = EXFAT_B_TO_BLK(byte_offset, sb); 854 sec += exfat_cluster_to_sector(sbi, clu); 855 856 bh = sb_bread(sb, sec); 857 if (!bh) 858 return -EIO; 859 es->bh[es->num_bh++] = bh; 860 861 ep = exfat_get_dentry_cached(es, 0); 862 if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode)) 863 goto put_es; 864 865 num_entries = type == ES_ALL_ENTRIES ? 866 ep->dentry.file.num_ext + 1 : type; 867 es->num_entries = num_entries; 868 869 num_bh = EXFAT_B_TO_BLK_ROUND_UP(off + num_entries * DENTRY_SIZE, sb); 870 if (num_bh > ARRAY_SIZE(es->__bh)) { 871 es->bh = kmalloc_array(num_bh, sizeof(*es->bh), GFP_KERNEL); 872 if (!es->bh) { 873 brelse(bh); 874 return -ENOMEM; 875 } 876 es->bh[0] = bh; 877 } 878 879 for (i = 1; i < num_bh; i++) { 880 /* get the next sector */ 881 if (exfat_is_last_sector_in_cluster(sbi, sec)) { 882 if (p_dir->flags == ALLOC_NO_FAT_CHAIN) 883 clu++; 884 else if (exfat_get_next_cluster(sb, &clu)) 885 goto put_es; 886 sec = exfat_cluster_to_sector(sbi, clu); 887 } else { 888 sec++; 889 } 890 891 bh = sb_bread(sb, sec); 892 if (!bh) 893 goto put_es; 894 es->bh[es->num_bh++] = bh; 895 } 896 897 /* validate cached dentries */ 898 for (i = 1; i < num_entries; i++) { 899 ep = exfat_get_dentry_cached(es, i); 900 if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode)) 901 goto put_es; 902 } 903 return 0; 904 905 put_es: 906 exfat_put_dentry_set(es, false); 907 return -EIO; 908 } 909 910 static inline void exfat_reset_empty_hint(struct exfat_hint_femp *hint_femp) 911 { 912 hint_femp->eidx = EXFAT_HINT_NONE; 913 hint_femp->count = 0; 914 } 915 916 static inline void exfat_set_empty_hint(struct exfat_inode_info *ei, 917 struct exfat_hint_femp *candi_empty, struct exfat_chain *clu, 918 int dentry, int num_entries, int entry_type) 919 { 920 if (ei->hint_femp.eidx == EXFAT_HINT_NONE || 921 ei->hint_femp.eidx > dentry) { 922 int total_entries = EXFAT_B_TO_DEN(i_size_read(&ei->vfs_inode)); 923 924 if (candi_empty->count == 0) { 925 candi_empty->cur = *clu; 926 candi_empty->eidx = dentry; 927 } 928 929 if (entry_type == TYPE_UNUSED) 930 candi_empty->count += total_entries - dentry; 931 else 932 candi_empty->count++; 933 934 if (candi_empty->count == num_entries || 935 candi_empty->count + candi_empty->eidx == total_entries) 936 ei->hint_femp = *candi_empty; 937 } 938 } 939 940 enum { 941 DIRENT_STEP_FILE, 942 DIRENT_STEP_STRM, 943 DIRENT_STEP_NAME, 944 DIRENT_STEP_SECD, 945 }; 946 947 /* 948 * @ei: inode info of parent directory 949 * @p_dir: directory structure of parent directory 950 * @num_entries:entry size of p_uniname 951 * @hint_opt: If p_uniname is found, filled with optimized dir/entry 952 * for traversing cluster chain. 953 * @return: 954 * >= 0: file directory entry position where the name exists 955 * -ENOENT: entry with the name does not exist 956 * -EIO: I/O error 957 */ 958 int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei, 959 struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname, 960 int num_entries, unsigned int type, struct exfat_hint *hint_opt) 961 { 962 int i, rewind = 0, dentry = 0, end_eidx = 0, num_ext = 0, len; 963 int order, step, name_len = 0; 964 int dentries_per_clu; 965 unsigned int entry_type; 966 unsigned short *uniname = NULL; 967 struct exfat_chain clu; 968 struct exfat_hint *hint_stat = &ei->hint_stat; 969 struct exfat_hint_femp candi_empty; 970 struct exfat_sb_info *sbi = EXFAT_SB(sb); 971 972 dentries_per_clu = sbi->dentries_per_clu; 973 974 exfat_chain_dup(&clu, p_dir); 975 976 if (hint_stat->eidx) { 977 clu.dir = hint_stat->clu; 978 dentry = hint_stat->eidx; 979 end_eidx = dentry; 980 } 981 982 exfat_reset_empty_hint(&ei->hint_femp); 983 984 rewind: 985 order = 0; 986 step = DIRENT_STEP_FILE; 987 exfat_reset_empty_hint(&candi_empty); 988 989 while (clu.dir != EXFAT_EOF_CLUSTER) { 990 i = dentry & (dentries_per_clu - 1); 991 for (; i < dentries_per_clu; i++, dentry++) { 992 struct exfat_dentry *ep; 993 struct buffer_head *bh; 994 995 if (rewind && dentry == end_eidx) 996 goto not_found; 997 998 ep = exfat_get_dentry(sb, &clu, i, &bh); 999 if (!ep) 1000 return -EIO; 1001 1002 entry_type = exfat_get_entry_type(ep); 1003 1004 if (entry_type == TYPE_UNUSED || 1005 entry_type == TYPE_DELETED) { 1006 step = DIRENT_STEP_FILE; 1007 1008 exfat_set_empty_hint(ei, &candi_empty, &clu, 1009 dentry, num_entries, 1010 entry_type); 1011 1012 brelse(bh); 1013 if (entry_type == TYPE_UNUSED) 1014 goto not_found; 1015 continue; 1016 } 1017 1018 exfat_reset_empty_hint(&candi_empty); 1019 1020 if (entry_type == TYPE_FILE || entry_type == TYPE_DIR) { 1021 step = DIRENT_STEP_FILE; 1022 hint_opt->clu = clu.dir; 1023 hint_opt->eidx = i; 1024 if (type == TYPE_ALL || type == entry_type) { 1025 num_ext = ep->dentry.file.num_ext; 1026 step = DIRENT_STEP_STRM; 1027 } 1028 brelse(bh); 1029 continue; 1030 } 1031 1032 if (entry_type == TYPE_STREAM) { 1033 u16 name_hash; 1034 1035 if (step != DIRENT_STEP_STRM) { 1036 step = DIRENT_STEP_FILE; 1037 brelse(bh); 1038 continue; 1039 } 1040 step = DIRENT_STEP_FILE; 1041 name_hash = le16_to_cpu( 1042 ep->dentry.stream.name_hash); 1043 if (p_uniname->name_hash == name_hash && 1044 p_uniname->name_len == 1045 ep->dentry.stream.name_len) { 1046 step = DIRENT_STEP_NAME; 1047 order = 1; 1048 name_len = 0; 1049 } 1050 brelse(bh); 1051 continue; 1052 } 1053 1054 brelse(bh); 1055 if (entry_type == TYPE_EXTEND) { 1056 unsigned short entry_uniname[16], unichar; 1057 1058 if (step != DIRENT_STEP_NAME) { 1059 step = DIRENT_STEP_FILE; 1060 continue; 1061 } 1062 1063 if (++order == 2) 1064 uniname = p_uniname->name; 1065 else 1066 uniname += EXFAT_FILE_NAME_LEN; 1067 1068 len = exfat_extract_uni_name(ep, entry_uniname); 1069 name_len += len; 1070 1071 unichar = *(uniname+len); 1072 *(uniname+len) = 0x0; 1073 1074 if (exfat_uniname_ncmp(sb, uniname, 1075 entry_uniname, len)) { 1076 step = DIRENT_STEP_FILE; 1077 } else if (p_uniname->name_len == name_len) { 1078 if (order == num_ext) 1079 goto found; 1080 step = DIRENT_STEP_SECD; 1081 } 1082 1083 *(uniname+len) = unichar; 1084 continue; 1085 } 1086 1087 if (entry_type & 1088 (TYPE_CRITICAL_SEC | TYPE_BENIGN_SEC)) { 1089 if (step == DIRENT_STEP_SECD) { 1090 if (++order == num_ext) 1091 goto found; 1092 continue; 1093 } 1094 } 1095 step = DIRENT_STEP_FILE; 1096 } 1097 1098 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1099 if (--clu.size > 0) 1100 clu.dir++; 1101 else 1102 clu.dir = EXFAT_EOF_CLUSTER; 1103 } else { 1104 if (exfat_get_next_cluster(sb, &clu.dir)) 1105 return -EIO; 1106 } 1107 } 1108 1109 not_found: 1110 /* 1111 * We started at not 0 index,so we should try to find target 1112 * from 0 index to the index we started at. 1113 */ 1114 if (!rewind && end_eidx) { 1115 rewind = 1; 1116 dentry = 0; 1117 clu.dir = p_dir->dir; 1118 goto rewind; 1119 } 1120 1121 /* 1122 * set the EXFAT_EOF_CLUSTER flag to avoid search 1123 * from the beginning again when allocated a new cluster 1124 */ 1125 if (ei->hint_femp.eidx == EXFAT_HINT_NONE) { 1126 ei->hint_femp.cur.dir = EXFAT_EOF_CLUSTER; 1127 ei->hint_femp.eidx = p_dir->size * dentries_per_clu; 1128 ei->hint_femp.count = 0; 1129 } 1130 1131 /* initialized hint_stat */ 1132 hint_stat->clu = p_dir->dir; 1133 hint_stat->eidx = 0; 1134 return -ENOENT; 1135 1136 found: 1137 /* next dentry we'll find is out of this cluster */ 1138 if (!((dentry + 1) & (dentries_per_clu - 1))) { 1139 int ret = 0; 1140 1141 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1142 if (--clu.size > 0) 1143 clu.dir++; 1144 else 1145 clu.dir = EXFAT_EOF_CLUSTER; 1146 } else { 1147 ret = exfat_get_next_cluster(sb, &clu.dir); 1148 } 1149 1150 if (ret || clu.dir == EXFAT_EOF_CLUSTER) { 1151 /* just initialized hint_stat */ 1152 hint_stat->clu = p_dir->dir; 1153 hint_stat->eidx = 0; 1154 return (dentry - num_ext); 1155 } 1156 } 1157 1158 hint_stat->clu = clu.dir; 1159 hint_stat->eidx = dentry + 1; 1160 return dentry - num_ext; 1161 } 1162 1163 int exfat_count_ext_entries(struct super_block *sb, struct exfat_chain *p_dir, 1164 int entry, struct exfat_dentry *ep) 1165 { 1166 int i, count = 0; 1167 unsigned int type; 1168 struct exfat_dentry *ext_ep; 1169 struct buffer_head *bh; 1170 1171 for (i = 0, entry++; i < ep->dentry.file.num_ext; i++, entry++) { 1172 ext_ep = exfat_get_dentry(sb, p_dir, entry, &bh); 1173 if (!ext_ep) 1174 return -EIO; 1175 1176 type = exfat_get_entry_type(ext_ep); 1177 brelse(bh); 1178 if (type == TYPE_EXTEND || type == TYPE_STREAM) 1179 count++; 1180 else 1181 break; 1182 } 1183 return count; 1184 } 1185 1186 int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir) 1187 { 1188 int i, count = 0; 1189 int dentries_per_clu; 1190 unsigned int entry_type; 1191 struct exfat_chain clu; 1192 struct exfat_dentry *ep; 1193 struct exfat_sb_info *sbi = EXFAT_SB(sb); 1194 struct buffer_head *bh; 1195 1196 dentries_per_clu = sbi->dentries_per_clu; 1197 1198 exfat_chain_dup(&clu, p_dir); 1199 1200 while (clu.dir != EXFAT_EOF_CLUSTER) { 1201 for (i = 0; i < dentries_per_clu; i++) { 1202 ep = exfat_get_dentry(sb, &clu, i, &bh); 1203 if (!ep) 1204 return -EIO; 1205 entry_type = exfat_get_entry_type(ep); 1206 brelse(bh); 1207 1208 if (entry_type == TYPE_UNUSED) 1209 return count; 1210 if (entry_type != TYPE_DIR) 1211 continue; 1212 count++; 1213 } 1214 1215 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1216 if (--clu.size > 0) 1217 clu.dir++; 1218 else 1219 clu.dir = EXFAT_EOF_CLUSTER; 1220 } else { 1221 if (exfat_get_next_cluster(sb, &(clu.dir))) 1222 return -EIO; 1223 } 1224 } 1225 1226 return count; 1227 } 1228