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