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 int 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, err; 36 struct exfat_entry_set_cache es; 37 unsigned int uni_len = 0, len; 38 39 err = exfat_get_dentry_set(&es, sb, p_dir, entry, ES_ALL_ENTRIES); 40 if (err) 41 return err; 42 43 /* 44 * First entry : file entry 45 * Second entry : stream-extension entry 46 * Third entry : first file-name entry 47 * So, the index of first file-name dentry should start from 2. 48 */ 49 for (i = ES_IDX_FIRST_FILENAME; i < es.num_entries; i++) { 50 struct exfat_dentry *ep = exfat_get_dentry_cached(&es, i); 51 52 /* end of name entry */ 53 if (exfat_get_entry_type(ep) != TYPE_EXTEND) 54 break; 55 56 len = exfat_extract_uni_name(ep, uniname); 57 uni_len += len; 58 if (len != EXFAT_FILE_NAME_LEN || uni_len >= MAX_NAME_LENGTH) 59 break; 60 uniname += EXFAT_FILE_NAME_LEN; 61 } 62 63 exfat_put_dentry_set(&es, false); 64 return 0; 65 } 66 67 /* read a directory entry from the opened directory */ 68 static int exfat_readdir(struct inode *inode, loff_t *cpos, struct exfat_dir_entry *dir_entry) 69 { 70 int i, dentries_per_clu, num_ext, err; 71 unsigned int type, clu_offset, max_dentries; 72 struct exfat_chain dir, clu; 73 struct exfat_uni_name uni_name; 74 struct exfat_dentry *ep; 75 struct super_block *sb = inode->i_sb; 76 struct exfat_sb_info *sbi = EXFAT_SB(sb); 77 struct exfat_inode_info *ei = EXFAT_I(inode); 78 unsigned int dentry = EXFAT_B_TO_DEN(*cpos) & 0xFFFFFFFF; 79 struct buffer_head *bh; 80 81 /* check if the given file ID is opened */ 82 if (ei->type != TYPE_DIR) 83 return -EPERM; 84 85 if (ei->entry == -1) 86 exfat_chain_set(&dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN); 87 else 88 exfat_chain_set(&dir, ei->start_clu, 89 EXFAT_B_TO_CLU(i_size_read(inode), sbi), ei->flags); 90 91 dentries_per_clu = sbi->dentries_per_clu; 92 max_dentries = (unsigned int)min_t(u64, MAX_EXFAT_DENTRIES, 93 (u64)EXFAT_CLU_TO_DEN(sbi->num_clusters, sbi)); 94 95 clu_offset = EXFAT_DEN_TO_CLU(dentry, sbi); 96 exfat_chain_dup(&clu, &dir); 97 98 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 99 clu.dir += clu_offset; 100 clu.size -= clu_offset; 101 } else { 102 /* hint_information */ 103 if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER && 104 ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) { 105 clu_offset -= ei->hint_bmap.off; 106 clu.dir = ei->hint_bmap.clu; 107 } 108 109 while (clu_offset > 0 && clu.dir != EXFAT_EOF_CLUSTER) { 110 if (exfat_get_next_cluster(sb, &(clu.dir))) 111 return -EIO; 112 113 clu_offset--; 114 } 115 } 116 117 while (clu.dir != EXFAT_EOF_CLUSTER && dentry < max_dentries) { 118 i = dentry & (dentries_per_clu - 1); 119 120 for ( ; i < dentries_per_clu; i++, dentry++) { 121 ep = exfat_get_dentry(sb, &clu, i, &bh); 122 if (!ep) 123 return -EIO; 124 125 type = exfat_get_entry_type(ep); 126 if (type == TYPE_UNUSED) { 127 brelse(bh); 128 break; 129 } 130 131 if (type != TYPE_FILE && type != TYPE_DIR) { 132 brelse(bh); 133 continue; 134 } 135 136 num_ext = ep->dentry.file.num_ext; 137 dir_entry->attr = le16_to_cpu(ep->dentry.file.attr); 138 exfat_get_entry_time(sbi, &dir_entry->crtime, 139 ep->dentry.file.create_tz, 140 ep->dentry.file.create_time, 141 ep->dentry.file.create_date, 142 ep->dentry.file.create_time_cs); 143 exfat_get_entry_time(sbi, &dir_entry->mtime, 144 ep->dentry.file.modify_tz, 145 ep->dentry.file.modify_time, 146 ep->dentry.file.modify_date, 147 ep->dentry.file.modify_time_cs); 148 exfat_get_entry_time(sbi, &dir_entry->atime, 149 ep->dentry.file.access_tz, 150 ep->dentry.file.access_time, 151 ep->dentry.file.access_date, 152 0); 153 154 *uni_name.name = 0x0; 155 err = exfat_get_uniname_from_ext_entry(sb, &clu, i, 156 uni_name.name); 157 if (err) { 158 brelse(bh); 159 continue; 160 } 161 exfat_utf16_to_nls(sb, &uni_name, 162 dir_entry->namebuf.lfn, 163 dir_entry->namebuf.lfnbuf_len); 164 brelse(bh); 165 166 ep = exfat_get_dentry(sb, &clu, i + 1, &bh); 167 if (!ep) 168 return -EIO; 169 dir_entry->size = 170 le64_to_cpu(ep->dentry.stream.valid_size); 171 dir_entry->entry = dentry; 172 brelse(bh); 173 174 ei->hint_bmap.off = EXFAT_DEN_TO_CLU(dentry, sbi); 175 ei->hint_bmap.clu = clu.dir; 176 177 *cpos = EXFAT_DEN_TO_B(dentry + 1 + num_ext); 178 return 0; 179 } 180 181 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 182 if (--clu.size > 0) 183 clu.dir++; 184 else 185 clu.dir = EXFAT_EOF_CLUSTER; 186 } else { 187 if (exfat_get_next_cluster(sb, &(clu.dir))) 188 return -EIO; 189 } 190 } 191 192 dir_entry->namebuf.lfn[0] = '\0'; 193 *cpos = EXFAT_DEN_TO_B(dentry); 194 return 0; 195 } 196 197 static void exfat_init_namebuf(struct exfat_dentry_namebuf *nb) 198 { 199 nb->lfn = NULL; 200 nb->lfnbuf_len = 0; 201 } 202 203 static int exfat_alloc_namebuf(struct exfat_dentry_namebuf *nb) 204 { 205 nb->lfn = __getname(); 206 if (!nb->lfn) 207 return -ENOMEM; 208 nb->lfnbuf_len = MAX_VFSNAME_BUF_SIZE; 209 return 0; 210 } 211 212 static void exfat_free_namebuf(struct exfat_dentry_namebuf *nb) 213 { 214 if (!nb->lfn) 215 return; 216 217 __putname(nb->lfn); 218 exfat_init_namebuf(nb); 219 } 220 221 /* 222 * Before calling dir_emit*(), sbi->s_lock should be released 223 * because page fault can occur in dir_emit*(). 224 */ 225 #define ITER_POS_FILLED_DOTS (2) 226 static int exfat_iterate(struct file *file, struct dir_context *ctx) 227 { 228 struct inode *inode = file_inode(file); 229 struct super_block *sb = inode->i_sb; 230 struct inode *tmp; 231 struct exfat_dir_entry de; 232 struct exfat_dentry_namebuf *nb = &(de.namebuf); 233 struct exfat_inode_info *ei = EXFAT_I(inode); 234 unsigned long inum; 235 loff_t cpos, i_pos; 236 int err = 0, fake_offset = 0; 237 238 exfat_init_namebuf(nb); 239 240 cpos = ctx->pos; 241 if (!dir_emit_dots(file, ctx)) 242 goto out; 243 244 if (ctx->pos == ITER_POS_FILLED_DOTS) { 245 cpos = 0; 246 fake_offset = 1; 247 } 248 249 cpos = round_up(cpos, DENTRY_SIZE); 250 251 /* name buffer should be allocated before use */ 252 err = exfat_alloc_namebuf(nb); 253 if (err) 254 goto out; 255 get_new: 256 mutex_lock(&EXFAT_SB(sb)->s_lock); 257 258 if (ei->flags == ALLOC_NO_FAT_CHAIN && cpos >= i_size_read(inode)) 259 goto end_of_dir; 260 261 err = exfat_readdir(inode, &cpos, &de); 262 if (err) { 263 /* 264 * At least we tried to read a sector. 265 * Move cpos to next sector position (should be aligned). 266 */ 267 if (err == -EIO) { 268 cpos += 1 << (sb->s_blocksize_bits); 269 cpos &= ~(sb->s_blocksize - 1); 270 } 271 272 err = -EIO; 273 goto end_of_dir; 274 } 275 276 if (!nb->lfn[0]) 277 goto end_of_dir; 278 279 i_pos = ((loff_t)ei->start_clu << 32) | (de.entry & 0xffffffff); 280 tmp = exfat_iget(sb, i_pos); 281 if (tmp) { 282 inum = tmp->i_ino; 283 iput(tmp); 284 } else { 285 inum = iunique(sb, EXFAT_ROOT_INO); 286 } 287 288 mutex_unlock(&EXFAT_SB(sb)->s_lock); 289 if (!dir_emit(ctx, nb->lfn, strlen(nb->lfn), inum, 290 (de.attr & EXFAT_ATTR_SUBDIR) ? DT_DIR : DT_REG)) 291 goto out; 292 ctx->pos = cpos; 293 goto get_new; 294 295 end_of_dir: 296 if (!cpos && fake_offset) 297 cpos = ITER_POS_FILLED_DOTS; 298 ctx->pos = cpos; 299 mutex_unlock(&EXFAT_SB(sb)->s_lock); 300 out: 301 /* 302 * To improve performance, free namebuf after unlock sb_lock. 303 * If namebuf is not allocated, this function do nothing 304 */ 305 exfat_free_namebuf(nb); 306 return err; 307 } 308 309 WRAP_DIR_ITER(exfat_iterate) // FIXME! 310 const struct file_operations exfat_dir_operations = { 311 .llseek = generic_file_llseek, 312 .read = generic_read_dir, 313 .iterate_shared = shared_exfat_iterate, 314 .unlocked_ioctl = exfat_ioctl, 315 #ifdef CONFIG_COMPAT 316 .compat_ioctl = exfat_compat_ioctl, 317 #endif 318 .fsync = exfat_file_fsync, 319 }; 320 321 int exfat_alloc_new_dir(struct inode *inode, struct exfat_chain *clu) 322 { 323 int ret; 324 325 exfat_chain_set(clu, EXFAT_EOF_CLUSTER, 0, ALLOC_NO_FAT_CHAIN); 326 327 ret = exfat_alloc_cluster(inode, 1, clu, IS_DIRSYNC(inode)); 328 if (ret) 329 return ret; 330 331 return exfat_zeroed_cluster(inode, clu->dir); 332 } 333 334 int exfat_calc_num_entries(struct exfat_uni_name *p_uniname) 335 { 336 int len; 337 338 len = p_uniname->name_len; 339 if (len == 0) 340 return -EINVAL; 341 342 /* 1 file entry + 1 stream entry + name entries */ 343 return ES_ENTRY_NUM(len); 344 } 345 346 unsigned int exfat_get_entry_type(struct exfat_dentry *ep) 347 { 348 if (ep->type == EXFAT_UNUSED) 349 return TYPE_UNUSED; 350 if (IS_EXFAT_DELETED(ep->type)) 351 return TYPE_DELETED; 352 if (ep->type == EXFAT_INVAL) 353 return TYPE_INVALID; 354 if (IS_EXFAT_CRITICAL_PRI(ep->type)) { 355 if (ep->type == EXFAT_BITMAP) 356 return TYPE_BITMAP; 357 if (ep->type == EXFAT_UPCASE) 358 return TYPE_UPCASE; 359 if (ep->type == EXFAT_VOLUME) 360 return TYPE_VOLUME; 361 if (ep->type == EXFAT_FILE) { 362 if (le16_to_cpu(ep->dentry.file.attr) & EXFAT_ATTR_SUBDIR) 363 return TYPE_DIR; 364 return TYPE_FILE; 365 } 366 return TYPE_CRITICAL_PRI; 367 } 368 if (IS_EXFAT_BENIGN_PRI(ep->type)) { 369 if (ep->type == EXFAT_GUID) 370 return TYPE_GUID; 371 if (ep->type == EXFAT_PADDING) 372 return TYPE_PADDING; 373 if (ep->type == EXFAT_ACLTAB) 374 return TYPE_ACLTAB; 375 return TYPE_BENIGN_PRI; 376 } 377 if (IS_EXFAT_CRITICAL_SEC(ep->type)) { 378 if (ep->type == EXFAT_STREAM) 379 return TYPE_STREAM; 380 if (ep->type == EXFAT_NAME) 381 return TYPE_EXTEND; 382 if (ep->type == EXFAT_ACL) 383 return TYPE_ACL; 384 return TYPE_CRITICAL_SEC; 385 } 386 387 if (ep->type == EXFAT_VENDOR_EXT) 388 return TYPE_VENDOR_EXT; 389 if (ep->type == EXFAT_VENDOR_ALLOC) 390 return TYPE_VENDOR_ALLOC; 391 392 return TYPE_BENIGN_SEC; 393 } 394 395 static void exfat_set_entry_type(struct exfat_dentry *ep, unsigned int type) 396 { 397 if (type == TYPE_UNUSED) { 398 ep->type = EXFAT_UNUSED; 399 } else if (type == TYPE_DELETED) { 400 ep->type &= EXFAT_DELETE; 401 } else if (type == TYPE_STREAM) { 402 ep->type = EXFAT_STREAM; 403 } else if (type == TYPE_EXTEND) { 404 ep->type = EXFAT_NAME; 405 } else if (type == TYPE_BITMAP) { 406 ep->type = EXFAT_BITMAP; 407 } else if (type == TYPE_UPCASE) { 408 ep->type = EXFAT_UPCASE; 409 } else if (type == TYPE_VOLUME) { 410 ep->type = EXFAT_VOLUME; 411 } else if (type == TYPE_DIR) { 412 ep->type = EXFAT_FILE; 413 ep->dentry.file.attr = cpu_to_le16(EXFAT_ATTR_SUBDIR); 414 } else if (type == TYPE_FILE) { 415 ep->type = EXFAT_FILE; 416 ep->dentry.file.attr = cpu_to_le16(EXFAT_ATTR_ARCHIVE); 417 } 418 } 419 420 static void exfat_init_stream_entry(struct exfat_dentry *ep, 421 unsigned int start_clu, unsigned long long size) 422 { 423 exfat_set_entry_type(ep, TYPE_STREAM); 424 if (size == 0) 425 ep->dentry.stream.flags = ALLOC_FAT_CHAIN; 426 else 427 ep->dentry.stream.flags = ALLOC_NO_FAT_CHAIN; 428 ep->dentry.stream.start_clu = cpu_to_le32(start_clu); 429 ep->dentry.stream.valid_size = cpu_to_le64(size); 430 ep->dentry.stream.size = cpu_to_le64(size); 431 } 432 433 static void exfat_init_name_entry(struct exfat_dentry *ep, 434 unsigned short *uniname) 435 { 436 int i; 437 438 exfat_set_entry_type(ep, TYPE_EXTEND); 439 ep->dentry.name.flags = 0x0; 440 441 for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) { 442 if (*uniname != 0x0) { 443 ep->dentry.name.unicode_0_14[i] = cpu_to_le16(*uniname); 444 uniname++; 445 } else { 446 ep->dentry.name.unicode_0_14[i] = 0x0; 447 } 448 } 449 } 450 451 int exfat_init_dir_entry(struct inode *inode, struct exfat_chain *p_dir, 452 int entry, unsigned int type, unsigned int start_clu, 453 unsigned long long size) 454 { 455 struct super_block *sb = inode->i_sb; 456 struct exfat_sb_info *sbi = EXFAT_SB(sb); 457 struct timespec64 ts = current_time(inode); 458 struct exfat_dentry *ep; 459 struct buffer_head *bh; 460 461 /* 462 * We cannot use exfat_get_dentry_set here because file ep is not 463 * initialized yet. 464 */ 465 ep = exfat_get_dentry(sb, p_dir, entry, &bh); 466 if (!ep) 467 return -EIO; 468 469 exfat_set_entry_type(ep, type); 470 exfat_set_entry_time(sbi, &ts, 471 &ep->dentry.file.create_tz, 472 &ep->dentry.file.create_time, 473 &ep->dentry.file.create_date, 474 &ep->dentry.file.create_time_cs); 475 exfat_set_entry_time(sbi, &ts, 476 &ep->dentry.file.modify_tz, 477 &ep->dentry.file.modify_time, 478 &ep->dentry.file.modify_date, 479 &ep->dentry.file.modify_time_cs); 480 exfat_set_entry_time(sbi, &ts, 481 &ep->dentry.file.access_tz, 482 &ep->dentry.file.access_time, 483 &ep->dentry.file.access_date, 484 NULL); 485 486 exfat_update_bh(bh, IS_DIRSYNC(inode)); 487 brelse(bh); 488 489 ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh); 490 if (!ep) 491 return -EIO; 492 493 exfat_init_stream_entry(ep, start_clu, size); 494 exfat_update_bh(bh, IS_DIRSYNC(inode)); 495 brelse(bh); 496 497 return 0; 498 } 499 500 int exfat_update_dir_chksum(struct inode *inode, struct exfat_chain *p_dir, 501 int entry) 502 { 503 struct super_block *sb = inode->i_sb; 504 int ret = 0; 505 int i, num_entries; 506 u16 chksum; 507 struct exfat_dentry *ep, *fep; 508 struct buffer_head *fbh, *bh; 509 510 fep = exfat_get_dentry(sb, p_dir, entry, &fbh); 511 if (!fep) 512 return -EIO; 513 514 num_entries = fep->dentry.file.num_ext + 1; 515 chksum = exfat_calc_chksum16(fep, DENTRY_SIZE, 0, CS_DIR_ENTRY); 516 517 for (i = 1; i < num_entries; i++) { 518 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh); 519 if (!ep) { 520 ret = -EIO; 521 goto release_fbh; 522 } 523 chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum, 524 CS_DEFAULT); 525 brelse(bh); 526 } 527 528 fep->dentry.file.checksum = cpu_to_le16(chksum); 529 exfat_update_bh(fbh, IS_DIRSYNC(inode)); 530 release_fbh: 531 brelse(fbh); 532 return ret; 533 } 534 535 static void exfat_free_benign_secondary_clusters(struct inode *inode, 536 struct exfat_dentry *ep) 537 { 538 struct super_block *sb = inode->i_sb; 539 struct exfat_chain dir; 540 unsigned int start_clu = 541 le32_to_cpu(ep->dentry.generic_secondary.start_clu); 542 u64 size = le64_to_cpu(ep->dentry.generic_secondary.size); 543 unsigned char flags = ep->dentry.generic_secondary.flags; 544 545 if (!(flags & ALLOC_POSSIBLE) || !start_clu || !size) 546 return; 547 548 exfat_chain_set(&dir, start_clu, 549 EXFAT_B_TO_CLU_ROUND_UP(size, EXFAT_SB(sb)), 550 flags); 551 exfat_free_cluster(inode, &dir); 552 } 553 554 int exfat_init_ext_entry(struct inode *inode, struct exfat_chain *p_dir, 555 int entry, int num_entries, struct exfat_uni_name *p_uniname) 556 { 557 struct super_block *sb = inode->i_sb; 558 int i; 559 unsigned short *uniname = p_uniname->name; 560 struct exfat_dentry *ep; 561 struct buffer_head *bh; 562 int sync = IS_DIRSYNC(inode); 563 564 ep = exfat_get_dentry(sb, p_dir, entry, &bh); 565 if (!ep) 566 return -EIO; 567 568 ep->dentry.file.num_ext = (unsigned char)(num_entries - 1); 569 exfat_update_bh(bh, sync); 570 brelse(bh); 571 572 ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh); 573 if (!ep) 574 return -EIO; 575 576 ep->dentry.stream.name_len = p_uniname->name_len; 577 ep->dentry.stream.name_hash = cpu_to_le16(p_uniname->name_hash); 578 exfat_update_bh(bh, sync); 579 brelse(bh); 580 581 for (i = EXFAT_FIRST_CLUSTER; i < num_entries; i++) { 582 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh); 583 if (!ep) 584 return -EIO; 585 586 if (exfat_get_entry_type(ep) & TYPE_BENIGN_SEC) 587 exfat_free_benign_secondary_clusters(inode, ep); 588 589 exfat_init_name_entry(ep, uniname); 590 exfat_update_bh(bh, sync); 591 brelse(bh); 592 uniname += EXFAT_FILE_NAME_LEN; 593 } 594 595 exfat_update_dir_chksum(inode, p_dir, entry); 596 return 0; 597 } 598 599 int exfat_remove_entries(struct inode *inode, struct exfat_chain *p_dir, 600 int entry, int order, int num_entries) 601 { 602 struct super_block *sb = inode->i_sb; 603 int i; 604 struct exfat_dentry *ep; 605 struct buffer_head *bh; 606 607 for (i = order; i < num_entries; i++) { 608 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh); 609 if (!ep) 610 return -EIO; 611 612 if (exfat_get_entry_type(ep) & TYPE_BENIGN_SEC) 613 exfat_free_benign_secondary_clusters(inode, ep); 614 615 exfat_set_entry_type(ep, TYPE_DELETED); 616 exfat_update_bh(bh, IS_DIRSYNC(inode)); 617 brelse(bh); 618 } 619 620 return 0; 621 } 622 623 void exfat_update_dir_chksum_with_entry_set(struct exfat_entry_set_cache *es) 624 { 625 int chksum_type = CS_DIR_ENTRY, i; 626 unsigned short chksum = 0; 627 struct exfat_dentry *ep; 628 629 for (i = ES_IDX_FILE; i < es->num_entries; i++) { 630 ep = exfat_get_dentry_cached(es, i); 631 chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum, 632 chksum_type); 633 chksum_type = CS_DEFAULT; 634 } 635 ep = exfat_get_dentry_cached(es, ES_IDX_FILE); 636 ep->dentry.file.checksum = cpu_to_le16(chksum); 637 es->modified = true; 638 } 639 640 int exfat_put_dentry_set(struct exfat_entry_set_cache *es, int sync) 641 { 642 int i, err = 0; 643 644 if (es->modified) 645 err = exfat_update_bhs(es->bh, es->num_bh, sync); 646 647 for (i = 0; i < es->num_bh; i++) 648 if (err) 649 bforget(es->bh[i]); 650 else 651 brelse(es->bh[i]); 652 653 if (IS_DYNAMIC_ES(es)) 654 kfree(es->bh); 655 656 return err; 657 } 658 659 static int exfat_walk_fat_chain(struct super_block *sb, 660 struct exfat_chain *p_dir, unsigned int byte_offset, 661 unsigned int *clu) 662 { 663 struct exfat_sb_info *sbi = EXFAT_SB(sb); 664 unsigned int clu_offset; 665 unsigned int cur_clu; 666 667 clu_offset = EXFAT_B_TO_CLU(byte_offset, sbi); 668 cur_clu = p_dir->dir; 669 670 if (p_dir->flags == ALLOC_NO_FAT_CHAIN) { 671 cur_clu += clu_offset; 672 } else { 673 while (clu_offset > 0) { 674 if (exfat_get_next_cluster(sb, &cur_clu)) 675 return -EIO; 676 if (cur_clu == EXFAT_EOF_CLUSTER) { 677 exfat_fs_error(sb, 678 "invalid dentry access beyond EOF (clu : %u, eidx : %d)", 679 p_dir->dir, 680 EXFAT_B_TO_DEN(byte_offset)); 681 return -EIO; 682 } 683 clu_offset--; 684 } 685 } 686 687 *clu = cur_clu; 688 return 0; 689 } 690 691 static int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir, 692 int entry, sector_t *sector, int *offset) 693 { 694 int ret; 695 unsigned int off, clu = 0; 696 struct exfat_sb_info *sbi = EXFAT_SB(sb); 697 698 off = EXFAT_DEN_TO_B(entry); 699 700 ret = exfat_walk_fat_chain(sb, p_dir, off, &clu); 701 if (ret) 702 return ret; 703 704 /* byte offset in cluster */ 705 off = EXFAT_CLU_OFFSET(off, sbi); 706 707 /* byte offset in sector */ 708 *offset = EXFAT_BLK_OFFSET(off, sb); 709 710 /* sector offset in cluster */ 711 *sector = EXFAT_B_TO_BLK(off, sb); 712 *sector += exfat_cluster_to_sector(sbi, clu); 713 return 0; 714 } 715 716 #define EXFAT_MAX_RA_SIZE (128*1024) 717 static int exfat_dir_readahead(struct super_block *sb, sector_t sec) 718 { 719 struct exfat_sb_info *sbi = EXFAT_SB(sb); 720 struct buffer_head *bh; 721 unsigned int max_ra_count = EXFAT_MAX_RA_SIZE >> sb->s_blocksize_bits; 722 unsigned int page_ra_count = PAGE_SIZE >> sb->s_blocksize_bits; 723 unsigned int adj_ra_count = max(sbi->sect_per_clus, page_ra_count); 724 unsigned int ra_count = min(adj_ra_count, max_ra_count); 725 726 /* Read-ahead is not required */ 727 if (sbi->sect_per_clus == 1) 728 return 0; 729 730 if (sec < sbi->data_start_sector) { 731 exfat_err(sb, "requested sector is invalid(sect:%llu, root:%llu)", 732 (unsigned long long)sec, sbi->data_start_sector); 733 return -EIO; 734 } 735 736 /* Not sector aligned with ra_count, resize ra_count to page size */ 737 if ((sec - sbi->data_start_sector) & (ra_count - 1)) 738 ra_count = page_ra_count; 739 740 bh = sb_find_get_block(sb, sec); 741 if (!bh || !buffer_uptodate(bh)) { 742 unsigned int i; 743 744 for (i = 0; i < ra_count; i++) 745 sb_breadahead(sb, (sector_t)(sec + i)); 746 } 747 brelse(bh); 748 return 0; 749 } 750 751 struct exfat_dentry *exfat_get_dentry(struct super_block *sb, 752 struct exfat_chain *p_dir, int entry, struct buffer_head **bh) 753 { 754 unsigned int dentries_per_page = EXFAT_B_TO_DEN(PAGE_SIZE); 755 int off; 756 sector_t sec; 757 758 if (p_dir->dir == DIR_DELETED) { 759 exfat_err(sb, "abnormal access to deleted dentry"); 760 return NULL; 761 } 762 763 if (exfat_find_location(sb, p_dir, entry, &sec, &off)) 764 return NULL; 765 766 if (p_dir->dir != EXFAT_FREE_CLUSTER && 767 !(entry & (dentries_per_page - 1))) 768 exfat_dir_readahead(sb, sec); 769 770 *bh = sb_bread(sb, sec); 771 if (!*bh) 772 return NULL; 773 774 return (struct exfat_dentry *)((*bh)->b_data + off); 775 } 776 777 enum exfat_validate_dentry_mode { 778 ES_MODE_STARTED, 779 ES_MODE_GET_FILE_ENTRY, 780 ES_MODE_GET_STRM_ENTRY, 781 ES_MODE_GET_NAME_ENTRY, 782 ES_MODE_GET_CRITICAL_SEC_ENTRY, 783 ES_MODE_GET_BENIGN_SEC_ENTRY, 784 }; 785 786 static bool exfat_validate_entry(unsigned int type, 787 enum exfat_validate_dentry_mode *mode) 788 { 789 if (type == TYPE_UNUSED || type == TYPE_DELETED) 790 return false; 791 792 switch (*mode) { 793 case ES_MODE_STARTED: 794 if (type != TYPE_FILE && type != TYPE_DIR) 795 return false; 796 *mode = ES_MODE_GET_FILE_ENTRY; 797 break; 798 case ES_MODE_GET_FILE_ENTRY: 799 if (type != TYPE_STREAM) 800 return false; 801 *mode = ES_MODE_GET_STRM_ENTRY; 802 break; 803 case ES_MODE_GET_STRM_ENTRY: 804 if (type != TYPE_EXTEND) 805 return false; 806 *mode = ES_MODE_GET_NAME_ENTRY; 807 break; 808 case ES_MODE_GET_NAME_ENTRY: 809 if (type & TYPE_BENIGN_SEC) 810 *mode = ES_MODE_GET_BENIGN_SEC_ENTRY; 811 else if (type != TYPE_EXTEND) 812 return false; 813 break; 814 case ES_MODE_GET_BENIGN_SEC_ENTRY: 815 /* Assume unreconized benign secondary entry */ 816 if (!(type & TYPE_BENIGN_SEC)) 817 return false; 818 break; 819 default: 820 return false; 821 } 822 823 return true; 824 } 825 826 struct exfat_dentry *exfat_get_dentry_cached( 827 struct exfat_entry_set_cache *es, int num) 828 { 829 int off = es->start_off + num * DENTRY_SIZE; 830 struct buffer_head *bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)]; 831 char *p = bh->b_data + EXFAT_BLK_OFFSET(off, es->sb); 832 833 return (struct exfat_dentry *)p; 834 } 835 836 /* 837 * Returns a set of dentries for a file or dir. 838 * 839 * Note It provides a direct pointer to bh->data via exfat_get_dentry_cached(). 840 * User should call exfat_get_dentry_set() after setting 'modified' to apply 841 * changes made in this entry set to the real device. 842 * 843 * in: 844 * sb+p_dir+entry: indicates a file/dir 845 * type: specifies how many dentries should be included. 846 * return: 847 * pointer of entry set on success, 848 * NULL on failure. 849 */ 850 int exfat_get_dentry_set(struct exfat_entry_set_cache *es, 851 struct super_block *sb, struct exfat_chain *p_dir, int entry, 852 unsigned int type) 853 { 854 int ret, i, num_bh; 855 unsigned int off; 856 sector_t sec; 857 struct exfat_sb_info *sbi = EXFAT_SB(sb); 858 struct exfat_dentry *ep; 859 int num_entries; 860 enum exfat_validate_dentry_mode mode = ES_MODE_STARTED; 861 struct buffer_head *bh; 862 863 if (p_dir->dir == DIR_DELETED) { 864 exfat_err(sb, "access to deleted dentry"); 865 return -EIO; 866 } 867 868 ret = exfat_find_location(sb, p_dir, entry, &sec, &off); 869 if (ret) 870 return ret; 871 872 memset(es, 0, sizeof(*es)); 873 es->sb = sb; 874 es->modified = false; 875 es->start_off = off; 876 es->bh = es->__bh; 877 878 bh = sb_bread(sb, sec); 879 if (!bh) 880 return -EIO; 881 es->bh[es->num_bh++] = bh; 882 883 ep = exfat_get_dentry_cached(es, ES_IDX_FILE); 884 if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode)) 885 goto put_es; 886 887 num_entries = type == ES_ALL_ENTRIES ? 888 ep->dentry.file.num_ext + 1 : type; 889 es->num_entries = num_entries; 890 891 num_bh = EXFAT_B_TO_BLK_ROUND_UP(off + num_entries * DENTRY_SIZE, sb); 892 if (num_bh > ARRAY_SIZE(es->__bh)) { 893 es->bh = kmalloc_array(num_bh, sizeof(*es->bh), GFP_KERNEL); 894 if (!es->bh) { 895 brelse(bh); 896 return -ENOMEM; 897 } 898 es->bh[0] = bh; 899 } 900 901 for (i = 1; i < num_bh; i++) { 902 /* get the next sector */ 903 if (exfat_is_last_sector_in_cluster(sbi, sec)) { 904 unsigned int clu = exfat_sector_to_cluster(sbi, sec); 905 906 if (p_dir->flags == ALLOC_NO_FAT_CHAIN) 907 clu++; 908 else if (exfat_get_next_cluster(sb, &clu)) 909 goto put_es; 910 sec = exfat_cluster_to_sector(sbi, clu); 911 } else { 912 sec++; 913 } 914 915 bh = sb_bread(sb, sec); 916 if (!bh) 917 goto put_es; 918 es->bh[es->num_bh++] = bh; 919 } 920 921 /* validate cached dentries */ 922 for (i = ES_IDX_STREAM; i < num_entries; i++) { 923 ep = exfat_get_dentry_cached(es, i); 924 if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode)) 925 goto put_es; 926 } 927 return 0; 928 929 put_es: 930 exfat_put_dentry_set(es, false); 931 return -EIO; 932 } 933 934 static inline void exfat_reset_empty_hint(struct exfat_hint_femp *hint_femp) 935 { 936 hint_femp->eidx = EXFAT_HINT_NONE; 937 hint_femp->count = 0; 938 } 939 940 static inline void exfat_set_empty_hint(struct exfat_inode_info *ei, 941 struct exfat_hint_femp *candi_empty, struct exfat_chain *clu, 942 int dentry, int num_entries, int entry_type) 943 { 944 if (ei->hint_femp.eidx == EXFAT_HINT_NONE || 945 ei->hint_femp.eidx > dentry) { 946 int total_entries = EXFAT_B_TO_DEN(i_size_read(&ei->vfs_inode)); 947 948 if (candi_empty->count == 0) { 949 candi_empty->cur = *clu; 950 candi_empty->eidx = dentry; 951 } 952 953 if (entry_type == TYPE_UNUSED) 954 candi_empty->count += total_entries - dentry; 955 else 956 candi_empty->count++; 957 958 if (candi_empty->count == num_entries || 959 candi_empty->count + candi_empty->eidx == total_entries) 960 ei->hint_femp = *candi_empty; 961 } 962 } 963 964 enum { 965 DIRENT_STEP_FILE, 966 DIRENT_STEP_STRM, 967 DIRENT_STEP_NAME, 968 DIRENT_STEP_SECD, 969 }; 970 971 /* 972 * @ei: inode info of parent directory 973 * @p_dir: directory structure of parent directory 974 * @num_entries:entry size of p_uniname 975 * @hint_opt: If p_uniname is found, filled with optimized dir/entry 976 * for traversing cluster chain. 977 * @return: 978 * >= 0: file directory entry position where the name exists 979 * -ENOENT: entry with the name does not exist 980 * -EIO: I/O error 981 */ 982 int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei, 983 struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname, 984 struct exfat_hint *hint_opt) 985 { 986 int i, rewind = 0, dentry = 0, end_eidx = 0, num_ext = 0, len; 987 int order, step, name_len = 0; 988 int dentries_per_clu; 989 unsigned int entry_type; 990 unsigned short *uniname = NULL; 991 struct exfat_chain clu; 992 struct exfat_hint *hint_stat = &ei->hint_stat; 993 struct exfat_hint_femp candi_empty; 994 struct exfat_sb_info *sbi = EXFAT_SB(sb); 995 int num_entries = exfat_calc_num_entries(p_uniname); 996 997 if (num_entries < 0) 998 return num_entries; 999 1000 dentries_per_clu = sbi->dentries_per_clu; 1001 1002 exfat_chain_dup(&clu, p_dir); 1003 1004 if (hint_stat->eidx) { 1005 clu.dir = hint_stat->clu; 1006 dentry = hint_stat->eidx; 1007 end_eidx = dentry; 1008 } 1009 1010 exfat_reset_empty_hint(&ei->hint_femp); 1011 1012 rewind: 1013 order = 0; 1014 step = DIRENT_STEP_FILE; 1015 exfat_reset_empty_hint(&candi_empty); 1016 1017 while (clu.dir != EXFAT_EOF_CLUSTER) { 1018 i = dentry & (dentries_per_clu - 1); 1019 for (; i < dentries_per_clu; i++, dentry++) { 1020 struct exfat_dentry *ep; 1021 struct buffer_head *bh; 1022 1023 if (rewind && dentry == end_eidx) 1024 goto not_found; 1025 1026 ep = exfat_get_dentry(sb, &clu, i, &bh); 1027 if (!ep) 1028 return -EIO; 1029 1030 entry_type = exfat_get_entry_type(ep); 1031 1032 if (entry_type == TYPE_UNUSED || 1033 entry_type == TYPE_DELETED) { 1034 step = DIRENT_STEP_FILE; 1035 1036 exfat_set_empty_hint(ei, &candi_empty, &clu, 1037 dentry, num_entries, 1038 entry_type); 1039 1040 brelse(bh); 1041 if (entry_type == TYPE_UNUSED) 1042 goto not_found; 1043 continue; 1044 } 1045 1046 exfat_reset_empty_hint(&candi_empty); 1047 1048 if (entry_type == TYPE_FILE || entry_type == TYPE_DIR) { 1049 step = DIRENT_STEP_FILE; 1050 hint_opt->clu = clu.dir; 1051 hint_opt->eidx = i; 1052 num_ext = ep->dentry.file.num_ext; 1053 step = DIRENT_STEP_STRM; 1054 brelse(bh); 1055 continue; 1056 } 1057 1058 if (entry_type == TYPE_STREAM) { 1059 u16 name_hash; 1060 1061 if (step != DIRENT_STEP_STRM) { 1062 step = DIRENT_STEP_FILE; 1063 brelse(bh); 1064 continue; 1065 } 1066 step = DIRENT_STEP_FILE; 1067 name_hash = le16_to_cpu( 1068 ep->dentry.stream.name_hash); 1069 if (p_uniname->name_hash == name_hash && 1070 p_uniname->name_len == 1071 ep->dentry.stream.name_len) { 1072 step = DIRENT_STEP_NAME; 1073 order = 1; 1074 name_len = 0; 1075 } 1076 brelse(bh); 1077 continue; 1078 } 1079 1080 brelse(bh); 1081 if (entry_type == TYPE_EXTEND) { 1082 unsigned short entry_uniname[16], unichar; 1083 1084 if (step != DIRENT_STEP_NAME || 1085 name_len >= MAX_NAME_LENGTH) { 1086 step = DIRENT_STEP_FILE; 1087 continue; 1088 } 1089 1090 if (++order == 2) 1091 uniname = p_uniname->name; 1092 else 1093 uniname += EXFAT_FILE_NAME_LEN; 1094 1095 len = exfat_extract_uni_name(ep, entry_uniname); 1096 name_len += len; 1097 1098 unichar = *(uniname+len); 1099 *(uniname+len) = 0x0; 1100 1101 if (exfat_uniname_ncmp(sb, uniname, 1102 entry_uniname, len)) { 1103 step = DIRENT_STEP_FILE; 1104 } else if (p_uniname->name_len == name_len) { 1105 if (order == num_ext) 1106 goto found; 1107 step = DIRENT_STEP_SECD; 1108 } 1109 1110 *(uniname+len) = unichar; 1111 continue; 1112 } 1113 1114 if (entry_type & 1115 (TYPE_CRITICAL_SEC | TYPE_BENIGN_SEC)) { 1116 if (step == DIRENT_STEP_SECD) { 1117 if (++order == num_ext) 1118 goto found; 1119 continue; 1120 } 1121 } 1122 step = DIRENT_STEP_FILE; 1123 } 1124 1125 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1126 if (--clu.size > 0) 1127 clu.dir++; 1128 else 1129 clu.dir = EXFAT_EOF_CLUSTER; 1130 } else { 1131 if (exfat_get_next_cluster(sb, &clu.dir)) 1132 return -EIO; 1133 } 1134 } 1135 1136 not_found: 1137 /* 1138 * We started at not 0 index,so we should try to find target 1139 * from 0 index to the index we started at. 1140 */ 1141 if (!rewind && end_eidx) { 1142 rewind = 1; 1143 dentry = 0; 1144 clu.dir = p_dir->dir; 1145 goto rewind; 1146 } 1147 1148 /* 1149 * set the EXFAT_EOF_CLUSTER flag to avoid search 1150 * from the beginning again when allocated a new cluster 1151 */ 1152 if (ei->hint_femp.eidx == EXFAT_HINT_NONE) { 1153 ei->hint_femp.cur.dir = EXFAT_EOF_CLUSTER; 1154 ei->hint_femp.eidx = p_dir->size * dentries_per_clu; 1155 ei->hint_femp.count = 0; 1156 } 1157 1158 /* initialized hint_stat */ 1159 hint_stat->clu = p_dir->dir; 1160 hint_stat->eidx = 0; 1161 return -ENOENT; 1162 1163 found: 1164 /* next dentry we'll find is out of this cluster */ 1165 if (!((dentry + 1) & (dentries_per_clu - 1))) { 1166 int ret = 0; 1167 1168 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1169 if (--clu.size > 0) 1170 clu.dir++; 1171 else 1172 clu.dir = EXFAT_EOF_CLUSTER; 1173 } else { 1174 ret = exfat_get_next_cluster(sb, &clu.dir); 1175 } 1176 1177 if (ret || clu.dir == EXFAT_EOF_CLUSTER) { 1178 /* just initialized hint_stat */ 1179 hint_stat->clu = p_dir->dir; 1180 hint_stat->eidx = 0; 1181 return (dentry - num_ext); 1182 } 1183 } 1184 1185 hint_stat->clu = clu.dir; 1186 hint_stat->eidx = dentry + 1; 1187 return dentry - num_ext; 1188 } 1189 1190 int exfat_count_ext_entries(struct super_block *sb, struct exfat_chain *p_dir, 1191 int entry, struct exfat_dentry *ep) 1192 { 1193 int i, count = 0; 1194 unsigned int type; 1195 struct exfat_dentry *ext_ep; 1196 struct buffer_head *bh; 1197 1198 for (i = 0, entry++; i < ep->dentry.file.num_ext; i++, entry++) { 1199 ext_ep = exfat_get_dentry(sb, p_dir, entry, &bh); 1200 if (!ext_ep) 1201 return -EIO; 1202 1203 type = exfat_get_entry_type(ext_ep); 1204 brelse(bh); 1205 if (type & TYPE_CRITICAL_SEC || type & TYPE_BENIGN_SEC) 1206 count++; 1207 } 1208 return count; 1209 } 1210 1211 int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir) 1212 { 1213 int i, count = 0; 1214 int dentries_per_clu; 1215 unsigned int entry_type; 1216 struct exfat_chain clu; 1217 struct exfat_dentry *ep; 1218 struct exfat_sb_info *sbi = EXFAT_SB(sb); 1219 struct buffer_head *bh; 1220 1221 dentries_per_clu = sbi->dentries_per_clu; 1222 1223 exfat_chain_dup(&clu, p_dir); 1224 1225 while (clu.dir != EXFAT_EOF_CLUSTER) { 1226 for (i = 0; i < dentries_per_clu; i++) { 1227 ep = exfat_get_dentry(sb, &clu, i, &bh); 1228 if (!ep) 1229 return -EIO; 1230 entry_type = exfat_get_entry_type(ep); 1231 brelse(bh); 1232 1233 if (entry_type == TYPE_UNUSED) 1234 return count; 1235 if (entry_type != TYPE_DIR) 1236 continue; 1237 count++; 1238 } 1239 1240 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1241 if (--clu.size > 0) 1242 clu.dir++; 1243 else 1244 clu.dir = EXFAT_EOF_CLUSTER; 1245 } else { 1246 if (exfat_get_next_cluster(sb, &(clu.dir))) 1247 return -EIO; 1248 } 1249 } 1250 1251 return count; 1252 } 1253