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 = ES_IDX_FIRST_FILENAME; 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, 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 max_dentries = (unsigned int)min_t(u64, MAX_EXFAT_DENTRIES, 87 (u64)EXFAT_CLU_TO_DEN(sbi->num_clusters, sbi)); 88 89 clu_offset = EXFAT_DEN_TO_CLU(dentry, sbi); 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 && dentry < max_dentries) { 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); 116 if (!ep) 117 return -EIO; 118 119 type = exfat_get_entry_type(ep); 120 if (type == TYPE_UNUSED) { 121 brelse(bh); 122 break; 123 } 124 125 if (type != TYPE_FILE && type != TYPE_DIR) { 126 brelse(bh); 127 continue; 128 } 129 130 num_ext = ep->dentry.file.num_ext; 131 dir_entry->attr = le16_to_cpu(ep->dentry.file.attr); 132 exfat_get_entry_time(sbi, &dir_entry->crtime, 133 ep->dentry.file.create_tz, 134 ep->dentry.file.create_time, 135 ep->dentry.file.create_date, 136 ep->dentry.file.create_time_cs); 137 exfat_get_entry_time(sbi, &dir_entry->mtime, 138 ep->dentry.file.modify_tz, 139 ep->dentry.file.modify_time, 140 ep->dentry.file.modify_date, 141 ep->dentry.file.modify_time_cs); 142 exfat_get_entry_time(sbi, &dir_entry->atime, 143 ep->dentry.file.access_tz, 144 ep->dentry.file.access_time, 145 ep->dentry.file.access_date, 146 0); 147 148 *uni_name.name = 0x0; 149 exfat_get_uniname_from_ext_entry(sb, &clu, i, 150 uni_name.name); 151 exfat_utf16_to_nls(sb, &uni_name, 152 dir_entry->namebuf.lfn, 153 dir_entry->namebuf.lfnbuf_len); 154 brelse(bh); 155 156 ep = exfat_get_dentry(sb, &clu, i + 1, &bh); 157 if (!ep) 158 return -EIO; 159 dir_entry->size = 160 le64_to_cpu(ep->dentry.stream.valid_size); 161 dir_entry->entry = dentry; 162 brelse(bh); 163 164 ei->hint_bmap.off = EXFAT_DEN_TO_CLU(dentry, sbi); 165 ei->hint_bmap.clu = clu.dir; 166 167 *cpos = EXFAT_DEN_TO_B(dentry + 1 + num_ext); 168 return 0; 169 } 170 171 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 172 if (--clu.size > 0) 173 clu.dir++; 174 else 175 clu.dir = EXFAT_EOF_CLUSTER; 176 } else { 177 if (exfat_get_next_cluster(sb, &(clu.dir))) 178 return -EIO; 179 } 180 } 181 182 dir_entry->namebuf.lfn[0] = '\0'; 183 *cpos = EXFAT_DEN_TO_B(dentry); 184 return 0; 185 } 186 187 static void exfat_init_namebuf(struct exfat_dentry_namebuf *nb) 188 { 189 nb->lfn = NULL; 190 nb->lfnbuf_len = 0; 191 } 192 193 static int exfat_alloc_namebuf(struct exfat_dentry_namebuf *nb) 194 { 195 nb->lfn = __getname(); 196 if (!nb->lfn) 197 return -ENOMEM; 198 nb->lfnbuf_len = MAX_VFSNAME_BUF_SIZE; 199 return 0; 200 } 201 202 static void exfat_free_namebuf(struct exfat_dentry_namebuf *nb) 203 { 204 if (!nb->lfn) 205 return; 206 207 __putname(nb->lfn); 208 exfat_init_namebuf(nb); 209 } 210 211 /* skip iterating emit_dots when dir is empty */ 212 #define ITER_POS_FILLED_DOTS (2) 213 static int exfat_iterate(struct file *file, struct dir_context *ctx) 214 { 215 struct inode *inode = file_inode(file); 216 struct super_block *sb = inode->i_sb; 217 struct inode *tmp; 218 struct exfat_dir_entry de; 219 struct exfat_dentry_namebuf *nb = &(de.namebuf); 220 struct exfat_inode_info *ei = EXFAT_I(inode); 221 unsigned long inum; 222 loff_t cpos, i_pos; 223 int err = 0, fake_offset = 0; 224 225 exfat_init_namebuf(nb); 226 mutex_lock(&EXFAT_SB(sb)->s_lock); 227 228 cpos = ctx->pos; 229 if (!dir_emit_dots(file, ctx)) 230 goto unlock; 231 232 if (ctx->pos == ITER_POS_FILLED_DOTS) { 233 cpos = 0; 234 fake_offset = 1; 235 } 236 237 if (cpos & (DENTRY_SIZE - 1)) { 238 err = -ENOENT; 239 goto unlock; 240 } 241 242 /* name buffer should be allocated before use */ 243 err = exfat_alloc_namebuf(nb); 244 if (err) 245 goto unlock; 246 get_new: 247 if (ei->flags == ALLOC_NO_FAT_CHAIN && cpos >= i_size_read(inode)) 248 goto end_of_dir; 249 250 err = exfat_readdir(inode, &cpos, &de); 251 if (err) { 252 /* 253 * At least we tried to read a sector. Move cpos to next sector 254 * position (should be aligned). 255 */ 256 if (err == -EIO) { 257 cpos += 1 << (sb->s_blocksize_bits); 258 cpos &= ~(sb->s_blocksize - 1); 259 } 260 261 err = -EIO; 262 goto end_of_dir; 263 } 264 265 if (!nb->lfn[0]) 266 goto end_of_dir; 267 268 i_pos = ((loff_t)ei->start_clu << 32) | (de.entry & 0xffffffff); 269 tmp = exfat_iget(sb, i_pos); 270 if (tmp) { 271 inum = tmp->i_ino; 272 iput(tmp); 273 } else { 274 inum = iunique(sb, EXFAT_ROOT_INO); 275 } 276 277 /* 278 * Before calling dir_emit(), sb_lock should be released. 279 * Because page fault can occur in dir_emit() when the size 280 * of buffer given from user is larger than one page size. 281 */ 282 mutex_unlock(&EXFAT_SB(sb)->s_lock); 283 if (!dir_emit(ctx, nb->lfn, strlen(nb->lfn), inum, 284 (de.attr & ATTR_SUBDIR) ? DT_DIR : DT_REG)) 285 goto out_unlocked; 286 mutex_lock(&EXFAT_SB(sb)->s_lock); 287 ctx->pos = cpos; 288 goto get_new; 289 290 end_of_dir: 291 if (!cpos && fake_offset) 292 cpos = ITER_POS_FILLED_DOTS; 293 ctx->pos = cpos; 294 unlock: 295 mutex_unlock(&EXFAT_SB(sb)->s_lock); 296 out_unlocked: 297 /* 298 * To improve performance, free namebuf after unlock sb_lock. 299 * If namebuf is not allocated, this function do nothing 300 */ 301 exfat_free_namebuf(nb); 302 return err; 303 } 304 305 const struct file_operations exfat_dir_operations = { 306 .llseek = generic_file_llseek, 307 .read = generic_read_dir, 308 .iterate = exfat_iterate, 309 .unlocked_ioctl = exfat_ioctl, 310 #ifdef CONFIG_COMPAT 311 .compat_ioctl = exfat_compat_ioctl, 312 #endif 313 .fsync = exfat_file_fsync, 314 }; 315 316 int exfat_alloc_new_dir(struct inode *inode, struct exfat_chain *clu) 317 { 318 int ret; 319 320 exfat_chain_set(clu, EXFAT_EOF_CLUSTER, 0, ALLOC_NO_FAT_CHAIN); 321 322 ret = exfat_alloc_cluster(inode, 1, clu, IS_DIRSYNC(inode)); 323 if (ret) 324 return ret; 325 326 return exfat_zeroed_cluster(inode, clu->dir); 327 } 328 329 int exfat_calc_num_entries(struct exfat_uni_name *p_uniname) 330 { 331 int len; 332 333 len = p_uniname->name_len; 334 if (len == 0) 335 return -EINVAL; 336 337 /* 1 file entry + 1 stream entry + name entries */ 338 return ES_ENTRY_NUM(len); 339 } 340 341 unsigned int exfat_get_entry_type(struct exfat_dentry *ep) 342 { 343 if (ep->type == EXFAT_UNUSED) 344 return TYPE_UNUSED; 345 if (IS_EXFAT_DELETED(ep->type)) 346 return TYPE_DELETED; 347 if (ep->type == EXFAT_INVAL) 348 return TYPE_INVALID; 349 if (IS_EXFAT_CRITICAL_PRI(ep->type)) { 350 if (ep->type == EXFAT_BITMAP) 351 return TYPE_BITMAP; 352 if (ep->type == EXFAT_UPCASE) 353 return TYPE_UPCASE; 354 if (ep->type == EXFAT_VOLUME) 355 return TYPE_VOLUME; 356 if (ep->type == EXFAT_FILE) { 357 if (le16_to_cpu(ep->dentry.file.attr) & ATTR_SUBDIR) 358 return TYPE_DIR; 359 return TYPE_FILE; 360 } 361 return TYPE_CRITICAL_PRI; 362 } 363 if (IS_EXFAT_BENIGN_PRI(ep->type)) { 364 if (ep->type == EXFAT_GUID) 365 return TYPE_GUID; 366 if (ep->type == EXFAT_PADDING) 367 return TYPE_PADDING; 368 if (ep->type == EXFAT_ACLTAB) 369 return TYPE_ACLTAB; 370 return TYPE_BENIGN_PRI; 371 } 372 if (IS_EXFAT_CRITICAL_SEC(ep->type)) { 373 if (ep->type == EXFAT_STREAM) 374 return TYPE_STREAM; 375 if (ep->type == EXFAT_NAME) 376 return TYPE_EXTEND; 377 if (ep->type == EXFAT_ACL) 378 return TYPE_ACL; 379 return TYPE_CRITICAL_SEC; 380 } 381 return TYPE_BENIGN_SEC; 382 } 383 384 static void exfat_set_entry_type(struct exfat_dentry *ep, unsigned int type) 385 { 386 if (type == TYPE_UNUSED) { 387 ep->type = EXFAT_UNUSED; 388 } else if (type == TYPE_DELETED) { 389 ep->type &= EXFAT_DELETE; 390 } else if (type == TYPE_STREAM) { 391 ep->type = EXFAT_STREAM; 392 } else if (type == TYPE_EXTEND) { 393 ep->type = EXFAT_NAME; 394 } else if (type == TYPE_BITMAP) { 395 ep->type = EXFAT_BITMAP; 396 } else if (type == TYPE_UPCASE) { 397 ep->type = EXFAT_UPCASE; 398 } else if (type == TYPE_VOLUME) { 399 ep->type = EXFAT_VOLUME; 400 } else if (type == TYPE_DIR) { 401 ep->type = EXFAT_FILE; 402 ep->dentry.file.attr = cpu_to_le16(ATTR_SUBDIR); 403 } else if (type == TYPE_FILE) { 404 ep->type = EXFAT_FILE; 405 ep->dentry.file.attr = cpu_to_le16(ATTR_ARCHIVE); 406 } 407 } 408 409 static void exfat_init_stream_entry(struct exfat_dentry *ep, 410 unsigned char flags, unsigned int start_clu, 411 unsigned long long size) 412 { 413 exfat_set_entry_type(ep, TYPE_STREAM); 414 ep->dentry.stream.flags = flags; 415 ep->dentry.stream.start_clu = cpu_to_le32(start_clu); 416 ep->dentry.stream.valid_size = cpu_to_le64(size); 417 ep->dentry.stream.size = cpu_to_le64(size); 418 } 419 420 static void exfat_init_name_entry(struct exfat_dentry *ep, 421 unsigned short *uniname) 422 { 423 int i; 424 425 exfat_set_entry_type(ep, TYPE_EXTEND); 426 ep->dentry.name.flags = 0x0; 427 428 for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) { 429 if (*uniname != 0x0) { 430 ep->dentry.name.unicode_0_14[i] = cpu_to_le16(*uniname); 431 uniname++; 432 } else { 433 ep->dentry.name.unicode_0_14[i] = 0x0; 434 } 435 } 436 } 437 438 int exfat_init_dir_entry(struct inode *inode, struct exfat_chain *p_dir, 439 int entry, unsigned int type, unsigned int start_clu, 440 unsigned long long size) 441 { 442 struct super_block *sb = inode->i_sb; 443 struct exfat_sb_info *sbi = EXFAT_SB(sb); 444 struct timespec64 ts = current_time(inode); 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); 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(bh, IS_DIRSYNC(inode)); 474 brelse(bh); 475 476 ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh); 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(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 u16 chksum; 496 struct exfat_dentry *ep, *fep; 497 struct buffer_head *fbh, *bh; 498 499 fep = exfat_get_dentry(sb, p_dir, entry, &fbh); 500 if (!fep) 501 return -EIO; 502 503 num_entries = fep->dentry.file.num_ext + 1; 504 chksum = exfat_calc_chksum16(fep, DENTRY_SIZE, 0, CS_DIR_ENTRY); 505 506 for (i = 1; i < num_entries; i++) { 507 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh); 508 if (!ep) { 509 ret = -EIO; 510 goto release_fbh; 511 } 512 chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum, 513 CS_DEFAULT); 514 brelse(bh); 515 } 516 517 fep->dentry.file.checksum = cpu_to_le16(chksum); 518 exfat_update_bh(fbh, IS_DIRSYNC(inode)); 519 release_fbh: 520 brelse(fbh); 521 return ret; 522 } 523 524 int exfat_init_ext_entry(struct inode *inode, struct exfat_chain *p_dir, 525 int entry, int num_entries, struct exfat_uni_name *p_uniname) 526 { 527 struct super_block *sb = inode->i_sb; 528 int i; 529 unsigned short *uniname = p_uniname->name; 530 struct exfat_dentry *ep; 531 struct buffer_head *bh; 532 int sync = IS_DIRSYNC(inode); 533 534 ep = exfat_get_dentry(sb, p_dir, entry, &bh); 535 if (!ep) 536 return -EIO; 537 538 ep->dentry.file.num_ext = (unsigned char)(num_entries - 1); 539 exfat_update_bh(bh, sync); 540 brelse(bh); 541 542 ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh); 543 if (!ep) 544 return -EIO; 545 546 ep->dentry.stream.name_len = p_uniname->name_len; 547 ep->dentry.stream.name_hash = cpu_to_le16(p_uniname->name_hash); 548 exfat_update_bh(bh, sync); 549 brelse(bh); 550 551 for (i = EXFAT_FIRST_CLUSTER; i < num_entries; i++) { 552 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh); 553 if (!ep) 554 return -EIO; 555 556 exfat_init_name_entry(ep, uniname); 557 exfat_update_bh(bh, sync); 558 brelse(bh); 559 uniname += EXFAT_FILE_NAME_LEN; 560 } 561 562 exfat_update_dir_chksum(inode, p_dir, entry); 563 return 0; 564 } 565 566 int exfat_remove_entries(struct inode *inode, struct exfat_chain *p_dir, 567 int entry, int order, int num_entries) 568 { 569 struct super_block *sb = inode->i_sb; 570 int i; 571 struct exfat_dentry *ep; 572 struct buffer_head *bh; 573 574 for (i = order; i < num_entries; i++) { 575 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh); 576 if (!ep) 577 return -EIO; 578 579 exfat_set_entry_type(ep, TYPE_DELETED); 580 exfat_update_bh(bh, IS_DIRSYNC(inode)); 581 brelse(bh); 582 } 583 584 return 0; 585 } 586 587 void exfat_update_dir_chksum_with_entry_set(struct exfat_entry_set_cache *es) 588 { 589 int chksum_type = CS_DIR_ENTRY, i; 590 unsigned short chksum = 0; 591 struct exfat_dentry *ep; 592 593 for (i = ES_IDX_FILE; i < es->num_entries; i++) { 594 ep = exfat_get_dentry_cached(es, i); 595 chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum, 596 chksum_type); 597 chksum_type = CS_DEFAULT; 598 } 599 ep = exfat_get_dentry_cached(es, ES_IDX_FILE); 600 ep->dentry.file.checksum = cpu_to_le16(chksum); 601 es->modified = true; 602 } 603 604 int exfat_put_dentry_set(struct exfat_entry_set_cache *es, int sync) 605 { 606 int i, err = 0; 607 608 if (es->modified) 609 err = exfat_update_bhs(es->bh, es->num_bh, sync); 610 611 for (i = 0; i < es->num_bh; i++) 612 if (err) 613 bforget(es->bh[i]); 614 else 615 brelse(es->bh[i]); 616 617 if (IS_DYNAMIC_ES(es)) 618 kfree(es->bh); 619 620 return err; 621 } 622 623 static int exfat_walk_fat_chain(struct super_block *sb, 624 struct exfat_chain *p_dir, unsigned int byte_offset, 625 unsigned int *clu) 626 { 627 struct exfat_sb_info *sbi = EXFAT_SB(sb); 628 unsigned int clu_offset; 629 unsigned int cur_clu; 630 631 clu_offset = EXFAT_B_TO_CLU(byte_offset, sbi); 632 cur_clu = p_dir->dir; 633 634 if (p_dir->flags == ALLOC_NO_FAT_CHAIN) { 635 cur_clu += clu_offset; 636 } else { 637 while (clu_offset > 0) { 638 if (exfat_get_next_cluster(sb, &cur_clu)) 639 return -EIO; 640 if (cur_clu == EXFAT_EOF_CLUSTER) { 641 exfat_fs_error(sb, 642 "invalid dentry access beyond EOF (clu : %u, eidx : %d)", 643 p_dir->dir, 644 EXFAT_B_TO_DEN(byte_offset)); 645 return -EIO; 646 } 647 clu_offset--; 648 } 649 } 650 651 *clu = cur_clu; 652 return 0; 653 } 654 655 static int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir, 656 int entry, sector_t *sector, int *offset) 657 { 658 int ret; 659 unsigned int off, clu = 0; 660 struct exfat_sb_info *sbi = EXFAT_SB(sb); 661 662 off = EXFAT_DEN_TO_B(entry); 663 664 ret = exfat_walk_fat_chain(sb, p_dir, off, &clu); 665 if (ret) 666 return ret; 667 668 /* byte offset in cluster */ 669 off = EXFAT_CLU_OFFSET(off, sbi); 670 671 /* byte offset in sector */ 672 *offset = EXFAT_BLK_OFFSET(off, sb); 673 674 /* sector offset in cluster */ 675 *sector = EXFAT_B_TO_BLK(off, sb); 676 *sector += exfat_cluster_to_sector(sbi, clu); 677 return 0; 678 } 679 680 #define EXFAT_MAX_RA_SIZE (128*1024) 681 static int exfat_dir_readahead(struct super_block *sb, sector_t sec) 682 { 683 struct exfat_sb_info *sbi = EXFAT_SB(sb); 684 struct buffer_head *bh; 685 unsigned int max_ra_count = EXFAT_MAX_RA_SIZE >> sb->s_blocksize_bits; 686 unsigned int page_ra_count = PAGE_SIZE >> sb->s_blocksize_bits; 687 unsigned int adj_ra_count = max(sbi->sect_per_clus, page_ra_count); 688 unsigned int ra_count = min(adj_ra_count, max_ra_count); 689 690 /* Read-ahead is not required */ 691 if (sbi->sect_per_clus == 1) 692 return 0; 693 694 if (sec < sbi->data_start_sector) { 695 exfat_err(sb, "requested sector is invalid(sect:%llu, root:%llu)", 696 (unsigned long long)sec, sbi->data_start_sector); 697 return -EIO; 698 } 699 700 /* Not sector aligned with ra_count, resize ra_count to page size */ 701 if ((sec - sbi->data_start_sector) & (ra_count - 1)) 702 ra_count = page_ra_count; 703 704 bh = sb_find_get_block(sb, sec); 705 if (!bh || !buffer_uptodate(bh)) { 706 unsigned int i; 707 708 for (i = 0; i < ra_count; i++) 709 sb_breadahead(sb, (sector_t)(sec + i)); 710 } 711 brelse(bh); 712 return 0; 713 } 714 715 struct exfat_dentry *exfat_get_dentry(struct super_block *sb, 716 struct exfat_chain *p_dir, int entry, struct buffer_head **bh) 717 { 718 unsigned int dentries_per_page = EXFAT_B_TO_DEN(PAGE_SIZE); 719 int off; 720 sector_t sec; 721 722 if (p_dir->dir == DIR_DELETED) { 723 exfat_err(sb, "abnormal access to deleted dentry"); 724 return NULL; 725 } 726 727 if (exfat_find_location(sb, p_dir, entry, &sec, &off)) 728 return NULL; 729 730 if (p_dir->dir != EXFAT_FREE_CLUSTER && 731 !(entry & (dentries_per_page - 1))) 732 exfat_dir_readahead(sb, sec); 733 734 *bh = sb_bread(sb, sec); 735 if (!*bh) 736 return NULL; 737 738 return (struct exfat_dentry *)((*bh)->b_data + off); 739 } 740 741 enum exfat_validate_dentry_mode { 742 ES_MODE_STARTED, 743 ES_MODE_GET_FILE_ENTRY, 744 ES_MODE_GET_STRM_ENTRY, 745 ES_MODE_GET_NAME_ENTRY, 746 ES_MODE_GET_CRITICAL_SEC_ENTRY, 747 }; 748 749 static bool exfat_validate_entry(unsigned int type, 750 enum exfat_validate_dentry_mode *mode) 751 { 752 if (type == TYPE_UNUSED || type == TYPE_DELETED) 753 return false; 754 755 switch (*mode) { 756 case ES_MODE_STARTED: 757 if (type != TYPE_FILE && type != TYPE_DIR) 758 return false; 759 *mode = ES_MODE_GET_FILE_ENTRY; 760 return true; 761 case ES_MODE_GET_FILE_ENTRY: 762 if (type != TYPE_STREAM) 763 return false; 764 *mode = ES_MODE_GET_STRM_ENTRY; 765 return true; 766 case ES_MODE_GET_STRM_ENTRY: 767 if (type != TYPE_EXTEND) 768 return false; 769 *mode = ES_MODE_GET_NAME_ENTRY; 770 return true; 771 case ES_MODE_GET_NAME_ENTRY: 772 if (type == TYPE_STREAM) 773 return false; 774 if (type != TYPE_EXTEND) { 775 if (!(type & TYPE_CRITICAL_SEC)) 776 return false; 777 *mode = ES_MODE_GET_CRITICAL_SEC_ENTRY; 778 } 779 return true; 780 case ES_MODE_GET_CRITICAL_SEC_ENTRY: 781 if (type == TYPE_EXTEND || type == TYPE_STREAM) 782 return false; 783 if ((type & TYPE_CRITICAL_SEC) != TYPE_CRITICAL_SEC) 784 return false; 785 return true; 786 default: 787 WARN_ON_ONCE(1); 788 return false; 789 } 790 } 791 792 struct exfat_dentry *exfat_get_dentry_cached( 793 struct exfat_entry_set_cache *es, int num) 794 { 795 int off = es->start_off + num * DENTRY_SIZE; 796 struct buffer_head *bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)]; 797 char *p = bh->b_data + EXFAT_BLK_OFFSET(off, es->sb); 798 799 return (struct exfat_dentry *)p; 800 } 801 802 /* 803 * Returns a set of dentries for a file or dir. 804 * 805 * Note It provides a direct pointer to bh->data via exfat_get_dentry_cached(). 806 * User should call exfat_get_dentry_set() after setting 'modified' to apply 807 * changes made in this entry set to the real device. 808 * 809 * in: 810 * sb+p_dir+entry: indicates a file/dir 811 * type: specifies how many dentries should be included. 812 * return: 813 * pointer of entry set on success, 814 * NULL on failure. 815 */ 816 int exfat_get_dentry_set(struct exfat_entry_set_cache *es, 817 struct super_block *sb, struct exfat_chain *p_dir, int entry, 818 unsigned int type) 819 { 820 int ret, i, num_bh; 821 unsigned int off; 822 sector_t sec; 823 struct exfat_sb_info *sbi = EXFAT_SB(sb); 824 struct exfat_dentry *ep; 825 int num_entries; 826 enum exfat_validate_dentry_mode mode = ES_MODE_STARTED; 827 struct buffer_head *bh; 828 829 if (p_dir->dir == DIR_DELETED) { 830 exfat_err(sb, "access to deleted dentry"); 831 return -EIO; 832 } 833 834 ret = exfat_find_location(sb, p_dir, entry, &sec, &off); 835 if (ret) 836 return ret; 837 838 memset(es, 0, sizeof(*es)); 839 es->sb = sb; 840 es->modified = false; 841 es->start_off = off; 842 es->bh = es->__bh; 843 844 bh = sb_bread(sb, sec); 845 if (!bh) 846 return -EIO; 847 es->bh[es->num_bh++] = bh; 848 849 ep = exfat_get_dentry_cached(es, ES_IDX_FILE); 850 if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode)) 851 goto put_es; 852 853 num_entries = type == ES_ALL_ENTRIES ? 854 ep->dentry.file.num_ext + 1 : type; 855 es->num_entries = num_entries; 856 857 num_bh = EXFAT_B_TO_BLK_ROUND_UP(off + num_entries * DENTRY_SIZE, sb); 858 if (num_bh > ARRAY_SIZE(es->__bh)) { 859 es->bh = kmalloc_array(num_bh, sizeof(*es->bh), GFP_KERNEL); 860 if (!es->bh) { 861 brelse(bh); 862 return -ENOMEM; 863 } 864 es->bh[0] = bh; 865 } 866 867 for (i = 1; i < num_bh; i++) { 868 /* get the next sector */ 869 if (exfat_is_last_sector_in_cluster(sbi, sec)) { 870 unsigned int clu = exfat_sector_to_cluster(sbi, sec); 871 872 if (p_dir->flags == ALLOC_NO_FAT_CHAIN) 873 clu++; 874 else if (exfat_get_next_cluster(sb, &clu)) 875 goto put_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 put_es; 884 es->bh[es->num_bh++] = bh; 885 } 886 887 /* validate cached dentries */ 888 for (i = ES_IDX_STREAM; 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 put_es; 892 } 893 return 0; 894 895 put_es: 896 exfat_put_dentry_set(es, false); 897 return -EIO; 898 } 899 900 static inline void exfat_reset_empty_hint(struct exfat_hint_femp *hint_femp) 901 { 902 hint_femp->eidx = EXFAT_HINT_NONE; 903 hint_femp->count = 0; 904 } 905 906 static inline void exfat_set_empty_hint(struct exfat_inode_info *ei, 907 struct exfat_hint_femp *candi_empty, struct exfat_chain *clu, 908 int dentry, int num_entries, int entry_type) 909 { 910 if (ei->hint_femp.eidx == EXFAT_HINT_NONE || 911 ei->hint_femp.eidx > dentry) { 912 int total_entries = EXFAT_B_TO_DEN(i_size_read(&ei->vfs_inode)); 913 914 if (candi_empty->count == 0) { 915 candi_empty->cur = *clu; 916 candi_empty->eidx = dentry; 917 } 918 919 if (entry_type == TYPE_UNUSED) 920 candi_empty->count += total_entries - dentry; 921 else 922 candi_empty->count++; 923 924 if (candi_empty->count == num_entries || 925 candi_empty->count + candi_empty->eidx == total_entries) 926 ei->hint_femp = *candi_empty; 927 } 928 } 929 930 enum { 931 DIRENT_STEP_FILE, 932 DIRENT_STEP_STRM, 933 DIRENT_STEP_NAME, 934 DIRENT_STEP_SECD, 935 }; 936 937 /* 938 * @ei: inode info of parent directory 939 * @p_dir: directory structure of parent directory 940 * @num_entries:entry size of p_uniname 941 * @hint_opt: If p_uniname is found, filled with optimized dir/entry 942 * for traversing cluster chain. 943 * @return: 944 * >= 0: file directory entry position where the name exists 945 * -ENOENT: entry with the name does not exist 946 * -EIO: I/O error 947 */ 948 int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei, 949 struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname, 950 struct exfat_hint *hint_opt) 951 { 952 int i, rewind = 0, dentry = 0, end_eidx = 0, num_ext = 0, len; 953 int order, step, name_len = 0; 954 int dentries_per_clu; 955 unsigned int entry_type; 956 unsigned short *uniname = NULL; 957 struct exfat_chain clu; 958 struct exfat_hint *hint_stat = &ei->hint_stat; 959 struct exfat_hint_femp candi_empty; 960 struct exfat_sb_info *sbi = EXFAT_SB(sb); 961 int num_entries = exfat_calc_num_entries(p_uniname); 962 963 if (num_entries < 0) 964 return num_entries; 965 966 dentries_per_clu = sbi->dentries_per_clu; 967 968 exfat_chain_dup(&clu, p_dir); 969 970 if (hint_stat->eidx) { 971 clu.dir = hint_stat->clu; 972 dentry = hint_stat->eidx; 973 end_eidx = dentry; 974 } 975 976 exfat_reset_empty_hint(&ei->hint_femp); 977 978 rewind: 979 order = 0; 980 step = DIRENT_STEP_FILE; 981 exfat_reset_empty_hint(&candi_empty); 982 983 while (clu.dir != EXFAT_EOF_CLUSTER) { 984 i = dentry & (dentries_per_clu - 1); 985 for (; i < dentries_per_clu; i++, dentry++) { 986 struct exfat_dentry *ep; 987 struct buffer_head *bh; 988 989 if (rewind && dentry == end_eidx) 990 goto not_found; 991 992 ep = exfat_get_dentry(sb, &clu, i, &bh); 993 if (!ep) 994 return -EIO; 995 996 entry_type = exfat_get_entry_type(ep); 997 998 if (entry_type == TYPE_UNUSED || 999 entry_type == TYPE_DELETED) { 1000 step = DIRENT_STEP_FILE; 1001 1002 exfat_set_empty_hint(ei, &candi_empty, &clu, 1003 dentry, num_entries, 1004 entry_type); 1005 1006 brelse(bh); 1007 if (entry_type == TYPE_UNUSED) 1008 goto not_found; 1009 continue; 1010 } 1011 1012 exfat_reset_empty_hint(&candi_empty); 1013 1014 if (entry_type == TYPE_FILE || entry_type == TYPE_DIR) { 1015 step = DIRENT_STEP_FILE; 1016 hint_opt->clu = clu.dir; 1017 hint_opt->eidx = i; 1018 num_ext = ep->dentry.file.num_ext; 1019 step = DIRENT_STEP_STRM; 1020 brelse(bh); 1021 continue; 1022 } 1023 1024 if (entry_type == TYPE_STREAM) { 1025 u16 name_hash; 1026 1027 if (step != DIRENT_STEP_STRM) { 1028 step = DIRENT_STEP_FILE; 1029 brelse(bh); 1030 continue; 1031 } 1032 step = DIRENT_STEP_FILE; 1033 name_hash = le16_to_cpu( 1034 ep->dentry.stream.name_hash); 1035 if (p_uniname->name_hash == name_hash && 1036 p_uniname->name_len == 1037 ep->dentry.stream.name_len) { 1038 step = DIRENT_STEP_NAME; 1039 order = 1; 1040 name_len = 0; 1041 } 1042 brelse(bh); 1043 continue; 1044 } 1045 1046 brelse(bh); 1047 if (entry_type == TYPE_EXTEND) { 1048 unsigned short entry_uniname[16], unichar; 1049 1050 if (step != DIRENT_STEP_NAME) { 1051 step = DIRENT_STEP_FILE; 1052 continue; 1053 } 1054 1055 if (++order == 2) 1056 uniname = p_uniname->name; 1057 else 1058 uniname += EXFAT_FILE_NAME_LEN; 1059 1060 len = exfat_extract_uni_name(ep, entry_uniname); 1061 name_len += len; 1062 1063 unichar = *(uniname+len); 1064 *(uniname+len) = 0x0; 1065 1066 if (exfat_uniname_ncmp(sb, uniname, 1067 entry_uniname, len)) { 1068 step = DIRENT_STEP_FILE; 1069 } else if (p_uniname->name_len == name_len) { 1070 if (order == num_ext) 1071 goto found; 1072 step = DIRENT_STEP_SECD; 1073 } 1074 1075 *(uniname+len) = unichar; 1076 continue; 1077 } 1078 1079 if (entry_type & 1080 (TYPE_CRITICAL_SEC | TYPE_BENIGN_SEC)) { 1081 if (step == DIRENT_STEP_SECD) { 1082 if (++order == num_ext) 1083 goto found; 1084 continue; 1085 } 1086 } 1087 step = DIRENT_STEP_FILE; 1088 } 1089 1090 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1091 if (--clu.size > 0) 1092 clu.dir++; 1093 else 1094 clu.dir = EXFAT_EOF_CLUSTER; 1095 } else { 1096 if (exfat_get_next_cluster(sb, &clu.dir)) 1097 return -EIO; 1098 } 1099 } 1100 1101 not_found: 1102 /* 1103 * We started at not 0 index,so we should try to find target 1104 * from 0 index to the index we started at. 1105 */ 1106 if (!rewind && end_eidx) { 1107 rewind = 1; 1108 dentry = 0; 1109 clu.dir = p_dir->dir; 1110 goto rewind; 1111 } 1112 1113 /* 1114 * set the EXFAT_EOF_CLUSTER flag to avoid search 1115 * from the beginning again when allocated a new cluster 1116 */ 1117 if (ei->hint_femp.eidx == EXFAT_HINT_NONE) { 1118 ei->hint_femp.cur.dir = EXFAT_EOF_CLUSTER; 1119 ei->hint_femp.eidx = p_dir->size * dentries_per_clu; 1120 ei->hint_femp.count = 0; 1121 } 1122 1123 /* initialized hint_stat */ 1124 hint_stat->clu = p_dir->dir; 1125 hint_stat->eidx = 0; 1126 return -ENOENT; 1127 1128 found: 1129 /* next dentry we'll find is out of this cluster */ 1130 if (!((dentry + 1) & (dentries_per_clu - 1))) { 1131 int ret = 0; 1132 1133 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1134 if (--clu.size > 0) 1135 clu.dir++; 1136 else 1137 clu.dir = EXFAT_EOF_CLUSTER; 1138 } else { 1139 ret = exfat_get_next_cluster(sb, &clu.dir); 1140 } 1141 1142 if (ret || clu.dir == EXFAT_EOF_CLUSTER) { 1143 /* just initialized hint_stat */ 1144 hint_stat->clu = p_dir->dir; 1145 hint_stat->eidx = 0; 1146 return (dentry - num_ext); 1147 } 1148 } 1149 1150 hint_stat->clu = clu.dir; 1151 hint_stat->eidx = dentry + 1; 1152 return dentry - num_ext; 1153 } 1154 1155 int exfat_count_ext_entries(struct super_block *sb, struct exfat_chain *p_dir, 1156 int entry, struct exfat_dentry *ep) 1157 { 1158 int i, count = 0; 1159 unsigned int type; 1160 struct exfat_dentry *ext_ep; 1161 struct buffer_head *bh; 1162 1163 for (i = 0, entry++; i < ep->dentry.file.num_ext; i++, entry++) { 1164 ext_ep = exfat_get_dentry(sb, p_dir, entry, &bh); 1165 if (!ext_ep) 1166 return -EIO; 1167 1168 type = exfat_get_entry_type(ext_ep); 1169 brelse(bh); 1170 if (type == TYPE_EXTEND || type == TYPE_STREAM) 1171 count++; 1172 else 1173 break; 1174 } 1175 return count; 1176 } 1177 1178 int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir) 1179 { 1180 int i, count = 0; 1181 int dentries_per_clu; 1182 unsigned int entry_type; 1183 struct exfat_chain clu; 1184 struct exfat_dentry *ep; 1185 struct exfat_sb_info *sbi = EXFAT_SB(sb); 1186 struct buffer_head *bh; 1187 1188 dentries_per_clu = sbi->dentries_per_clu; 1189 1190 exfat_chain_dup(&clu, p_dir); 1191 1192 while (clu.dir != EXFAT_EOF_CLUSTER) { 1193 for (i = 0; i < dentries_per_clu; i++) { 1194 ep = exfat_get_dentry(sb, &clu, i, &bh); 1195 if (!ep) 1196 return -EIO; 1197 entry_type = exfat_get_entry_type(ep); 1198 brelse(bh); 1199 1200 if (entry_type == TYPE_UNUSED) 1201 return count; 1202 if (entry_type != TYPE_DIR) 1203 continue; 1204 count++; 1205 } 1206 1207 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1208 if (--clu.size > 0) 1209 clu.dir++; 1210 else 1211 clu.dir = EXFAT_EOF_CLUSTER; 1212 } else { 1213 if (exfat_get_next_cluster(sb, &(clu.dir))) 1214 return -EIO; 1215 } 1216 } 1217 1218 return count; 1219 } 1220