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 #include <linux/filelock.h> 11 12 #include "exfat_raw.h" 13 #include "exfat_fs.h" 14 15 static int exfat_extract_uni_name(struct exfat_dentry *ep, 16 unsigned short *uniname) 17 { 18 int i, len = 0; 19 20 for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) { 21 *uniname = le16_to_cpu(ep->dentry.name.unicode_0_14[i]); 22 if (*uniname == 0x0) 23 return len; 24 uniname++; 25 len++; 26 } 27 28 *uniname = 0x0; 29 return len; 30 31 } 32 33 static int exfat_get_uniname_from_ext_entry(struct super_block *sb, 34 struct exfat_chain *p_dir, int entry, unsigned short *uniname) 35 { 36 int i, err; 37 struct exfat_entry_set_cache es; 38 unsigned int uni_len = 0, len; 39 40 err = exfat_get_dentry_set(&es, sb, p_dir, entry, ES_ALL_ENTRIES); 41 if (err) 42 return err; 43 44 /* 45 * First entry : file entry 46 * Second entry : stream-extension entry 47 * Third entry : first file-name entry 48 * So, the index of first file-name dentry should start from 2. 49 */ 50 for (i = ES_IDX_FIRST_FILENAME; i < es.num_entries; i++) { 51 struct exfat_dentry *ep = exfat_get_dentry_cached(&es, i); 52 53 /* end of name entry */ 54 if (exfat_get_entry_type(ep) != TYPE_EXTEND) 55 break; 56 57 len = exfat_extract_uni_name(ep, uniname); 58 uni_len += len; 59 if (len != EXFAT_FILE_NAME_LEN || uni_len >= MAX_NAME_LENGTH) 60 break; 61 uniname += EXFAT_FILE_NAME_LEN; 62 } 63 64 exfat_put_dentry_set(&es, false); 65 return 0; 66 } 67 68 /* read a directory entry from the opened directory */ 69 static int exfat_readdir(struct inode *inode, loff_t *cpos, struct exfat_dir_entry *dir_entry) 70 { 71 int i, dentries_per_clu, num_ext, err; 72 unsigned int type, clu_offset, max_dentries; 73 struct exfat_chain dir, clu; 74 struct exfat_uni_name uni_name; 75 struct exfat_dentry *ep; 76 struct super_block *sb = inode->i_sb; 77 struct exfat_sb_info *sbi = EXFAT_SB(sb); 78 struct exfat_inode_info *ei = EXFAT_I(inode); 79 unsigned int dentry = EXFAT_B_TO_DEN(*cpos) & 0xFFFFFFFF; 80 struct buffer_head *bh; 81 82 /* check if the given file ID is opened */ 83 if (ei->type != TYPE_DIR) 84 return -EPERM; 85 86 exfat_chain_set(&dir, ei->start_clu, 87 EXFAT_B_TO_CLU(i_size_read(inode), sbi), ei->flags); 88 89 dentries_per_clu = sbi->dentries_per_clu; 90 max_dentries = (unsigned int)min_t(u64, MAX_EXFAT_DENTRIES, 91 (u64)EXFAT_CLU_TO_DEN(sbi->num_clusters, sbi)); 92 93 clu_offset = EXFAT_DEN_TO_CLU(dentry, sbi); 94 exfat_chain_dup(&clu, &dir); 95 96 if (clu.flags == ALLOC_FAT_CHAIN) { 97 /* hint_information */ 98 if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER && 99 ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) { 100 clu_offset -= ei->hint_bmap.off; 101 clu.dir = ei->hint_bmap.clu; 102 clu.size -= ei->hint_bmap.off; 103 } 104 } 105 106 if (exfat_chain_advance(sb, &clu, clu_offset)) 107 return -EIO; 108 109 while (clu.dir != EXFAT_EOF_CLUSTER && dentry < max_dentries) { 110 i = dentry & (dentries_per_clu - 1); 111 112 for ( ; i < dentries_per_clu; i++, dentry++) { 113 ep = exfat_get_dentry(sb, &clu, i, &bh); 114 if (!ep) 115 return -EIO; 116 117 type = exfat_get_entry_type(ep); 118 if (type == TYPE_UNUSED) { 119 brelse(bh); 120 goto out; 121 } 122 123 if (type != TYPE_FILE && type != TYPE_DIR) { 124 brelse(bh); 125 continue; 126 } 127 128 num_ext = ep->dentry.file.num_ext; 129 dir_entry->attr = le16_to_cpu(ep->dentry.file.attr); 130 131 *uni_name.name = 0x0; 132 err = exfat_get_uniname_from_ext_entry(sb, &clu, i, 133 uni_name.name); 134 if (err) { 135 brelse(bh); 136 continue; 137 } 138 exfat_utf16_to_nls(sb, &uni_name, 139 dir_entry->namebuf.lfn, 140 dir_entry->namebuf.lfnbuf_len); 141 brelse(bh); 142 143 ep = exfat_get_dentry(sb, &clu, i + 1, &bh); 144 if (!ep) 145 return -EIO; 146 dir_entry->entry = i; 147 dir_entry->dir = clu; 148 brelse(bh); 149 150 ei->hint_bmap.off = EXFAT_DEN_TO_CLU(dentry, sbi); 151 ei->hint_bmap.clu = clu.dir; 152 153 *cpos = EXFAT_DEN_TO_B(dentry + 1 + num_ext); 154 return 0; 155 } 156 157 if (exfat_chain_advance(sb, &clu, 1)) 158 return -EIO; 159 } 160 161 out: 162 dir_entry->namebuf.lfn[0] = '\0'; 163 *cpos = EXFAT_DEN_TO_B(dentry); 164 return 0; 165 } 166 167 static void exfat_init_namebuf(struct exfat_dentry_namebuf *nb) 168 { 169 nb->lfn = NULL; 170 nb->lfnbuf_len = 0; 171 } 172 173 static int exfat_alloc_namebuf(struct exfat_dentry_namebuf *nb) 174 { 175 nb->lfn = __getname(); 176 if (!nb->lfn) 177 return -ENOMEM; 178 nb->lfnbuf_len = MAX_VFSNAME_BUF_SIZE; 179 return 0; 180 } 181 182 static void exfat_free_namebuf(struct exfat_dentry_namebuf *nb) 183 { 184 if (!nb->lfn) 185 return; 186 187 __putname(nb->lfn); 188 exfat_init_namebuf(nb); 189 } 190 191 /* 192 * Before calling dir_emit*(), sbi->s_lock should be released 193 * because page fault can occur in dir_emit*(). 194 */ 195 #define ITER_POS_FILLED_DOTS (2) 196 static int exfat_iterate(struct file *file, struct dir_context *ctx) 197 { 198 struct inode *inode = file_inode(file); 199 struct super_block *sb = inode->i_sb; 200 struct inode *tmp; 201 struct exfat_dir_entry de; 202 struct exfat_dentry_namebuf *nb = &(de.namebuf); 203 struct exfat_inode_info *ei = EXFAT_I(inode); 204 unsigned long inum; 205 loff_t cpos, i_pos; 206 int err = 0, fake_offset = 0; 207 208 exfat_init_namebuf(nb); 209 210 cpos = ctx->pos; 211 if (!dir_emit_dots(file, ctx)) 212 goto out; 213 214 if (ctx->pos == ITER_POS_FILLED_DOTS) { 215 cpos = 0; 216 fake_offset = 1; 217 } 218 219 cpos = round_up(cpos, DENTRY_SIZE); 220 221 /* name buffer should be allocated before use */ 222 err = exfat_alloc_namebuf(nb); 223 if (err) 224 goto out; 225 get_new: 226 mutex_lock(&EXFAT_SB(sb)->s_lock); 227 228 if (ei->flags == ALLOC_NO_FAT_CHAIN && cpos >= i_size_read(inode)) 229 goto end_of_dir; 230 231 err = exfat_readdir(inode, &cpos, &de); 232 if (err) { 233 /* 234 * At least we tried to read a sector. 235 * Move cpos to next sector position (should be aligned). 236 */ 237 if (err == -EIO) { 238 cpos += 1 << (sb->s_blocksize_bits); 239 cpos &= ~(loff_t)(sb->s_blocksize - 1); 240 } 241 242 err = -EIO; 243 goto end_of_dir; 244 } 245 246 if (!nb->lfn[0]) 247 goto end_of_dir; 248 249 i_pos = ((loff_t)de.dir.dir << 32) | (de.entry & 0xffffffff); 250 tmp = exfat_iget(sb, i_pos); 251 if (tmp) { 252 inum = tmp->i_ino; 253 iput(tmp); 254 } else { 255 inum = iunique(sb, EXFAT_ROOT_INO); 256 } 257 258 mutex_unlock(&EXFAT_SB(sb)->s_lock); 259 if (!dir_emit(ctx, nb->lfn, strlen(nb->lfn), inum, 260 (de.attr & EXFAT_ATTR_SUBDIR) ? DT_DIR : DT_REG)) 261 goto out; 262 ctx->pos = cpos; 263 goto get_new; 264 265 end_of_dir: 266 if (!cpos && fake_offset) 267 cpos = ITER_POS_FILLED_DOTS; 268 ctx->pos = cpos; 269 mutex_unlock(&EXFAT_SB(sb)->s_lock); 270 out: 271 /* 272 * To improve performance, free namebuf after unlock sb_lock. 273 * If namebuf is not allocated, this function do nothing 274 */ 275 exfat_free_namebuf(nb); 276 return err; 277 } 278 279 WRAP_DIR_ITER(exfat_iterate) // FIXME! 280 const struct file_operations exfat_dir_operations = { 281 .llseek = generic_file_llseek, 282 .read = generic_read_dir, 283 .iterate_shared = shared_exfat_iterate, 284 .unlocked_ioctl = exfat_ioctl, 285 #ifdef CONFIG_COMPAT 286 .compat_ioctl = exfat_compat_ioctl, 287 #endif 288 .fsync = exfat_file_fsync, 289 .setlease = generic_setlease, 290 }; 291 292 int exfat_alloc_new_dir(struct inode *inode, struct exfat_chain *clu) 293 { 294 int ret; 295 296 exfat_chain_set(clu, EXFAT_EOF_CLUSTER, 0, ALLOC_NO_FAT_CHAIN); 297 298 ret = exfat_alloc_cluster(inode, 1, clu, IS_DIRSYNC(inode)); 299 if (ret) 300 return ret; 301 302 return exfat_zeroed_cluster(inode, clu->dir); 303 } 304 305 int exfat_calc_num_entries(struct exfat_uni_name *p_uniname) 306 { 307 int len; 308 309 len = p_uniname->name_len; 310 if (len == 0) 311 return -EINVAL; 312 313 /* 1 file entry + 1 stream entry + name entries */ 314 return ES_ENTRY_NUM(len); 315 } 316 317 unsigned int exfat_get_entry_type(struct exfat_dentry *ep) 318 { 319 if (ep->type == EXFAT_UNUSED) 320 return TYPE_UNUSED; 321 if (IS_EXFAT_DELETED(ep->type)) 322 return TYPE_DELETED; 323 if (ep->type == EXFAT_INVAL) 324 return TYPE_INVALID; 325 if (IS_EXFAT_CRITICAL_PRI(ep->type)) { 326 if (ep->type == EXFAT_BITMAP) 327 return TYPE_BITMAP; 328 if (ep->type == EXFAT_UPCASE) 329 return TYPE_UPCASE; 330 if (ep->type == EXFAT_VOLUME) 331 return TYPE_VOLUME; 332 if (ep->type == EXFAT_FILE) { 333 if (le16_to_cpu(ep->dentry.file.attr) & EXFAT_ATTR_SUBDIR) 334 return TYPE_DIR; 335 return TYPE_FILE; 336 } 337 return TYPE_CRITICAL_PRI; 338 } 339 if (IS_EXFAT_BENIGN_PRI(ep->type)) { 340 if (ep->type == EXFAT_GUID) 341 return TYPE_GUID; 342 if (ep->type == EXFAT_PADDING) 343 return TYPE_PADDING; 344 if (ep->type == EXFAT_ACLTAB) 345 return TYPE_ACLTAB; 346 return TYPE_BENIGN_PRI; 347 } 348 if (IS_EXFAT_CRITICAL_SEC(ep->type)) { 349 if (ep->type == EXFAT_STREAM) 350 return TYPE_STREAM; 351 if (ep->type == EXFAT_NAME) 352 return TYPE_EXTEND; 353 if (ep->type == EXFAT_ACL) 354 return TYPE_ACL; 355 return TYPE_CRITICAL_SEC; 356 } 357 358 if (ep->type == EXFAT_VENDOR_EXT) 359 return TYPE_VENDOR_EXT; 360 if (ep->type == EXFAT_VENDOR_ALLOC) 361 return TYPE_VENDOR_ALLOC; 362 363 return TYPE_BENIGN_SEC; 364 } 365 366 static void exfat_set_entry_type(struct exfat_dentry *ep, unsigned int type) 367 { 368 if (type == TYPE_UNUSED) { 369 ep->type = EXFAT_UNUSED; 370 } else if (type == TYPE_DELETED) { 371 ep->type &= EXFAT_DELETE; 372 } else if (type == TYPE_STREAM) { 373 ep->type = EXFAT_STREAM; 374 } else if (type == TYPE_EXTEND) { 375 ep->type = EXFAT_NAME; 376 } else if (type == TYPE_BITMAP) { 377 ep->type = EXFAT_BITMAP; 378 } else if (type == TYPE_UPCASE) { 379 ep->type = EXFAT_UPCASE; 380 } else if (type == TYPE_VOLUME) { 381 ep->type = EXFAT_VOLUME; 382 } else if (type == TYPE_DIR) { 383 ep->type = EXFAT_FILE; 384 ep->dentry.file.attr = cpu_to_le16(EXFAT_ATTR_SUBDIR); 385 } else if (type == TYPE_FILE) { 386 ep->type = EXFAT_FILE; 387 ep->dentry.file.attr = cpu_to_le16(EXFAT_ATTR_ARCHIVE); 388 } 389 } 390 391 static void exfat_init_stream_entry(struct exfat_dentry *ep, 392 unsigned int start_clu, unsigned long long size) 393 { 394 memset(ep, 0, sizeof(*ep)); 395 exfat_set_entry_type(ep, TYPE_STREAM); 396 if (size == 0) 397 ep->dentry.stream.flags = ALLOC_FAT_CHAIN; 398 else 399 ep->dentry.stream.flags = ALLOC_NO_FAT_CHAIN; 400 ep->dentry.stream.start_clu = cpu_to_le32(start_clu); 401 ep->dentry.stream.valid_size = cpu_to_le64(size); 402 ep->dentry.stream.size = cpu_to_le64(size); 403 } 404 405 static void exfat_init_name_entry(struct exfat_dentry *ep, 406 unsigned short *uniname) 407 { 408 int i; 409 410 exfat_set_entry_type(ep, TYPE_EXTEND); 411 ep->dentry.name.flags = 0x0; 412 413 for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) { 414 if (*uniname != 0x0) { 415 ep->dentry.name.unicode_0_14[i] = cpu_to_le16(*uniname); 416 uniname++; 417 } else { 418 ep->dentry.name.unicode_0_14[i] = 0x0; 419 } 420 } 421 } 422 423 void exfat_init_dir_entry(struct exfat_entry_set_cache *es, 424 unsigned int type, unsigned int start_clu, 425 unsigned long long size, struct timespec64 *ts) 426 { 427 struct super_block *sb = es->sb; 428 struct exfat_sb_info *sbi = EXFAT_SB(sb); 429 struct exfat_dentry *ep; 430 431 ep = exfat_get_dentry_cached(es, ES_IDX_FILE); 432 memset(ep, 0, sizeof(*ep)); 433 exfat_set_entry_type(ep, type); 434 exfat_set_entry_time(sbi, ts, 435 &ep->dentry.file.create_tz, 436 &ep->dentry.file.create_time, 437 &ep->dentry.file.create_date, 438 &ep->dentry.file.create_time_cs); 439 exfat_set_entry_time(sbi, ts, 440 &ep->dentry.file.modify_tz, 441 &ep->dentry.file.modify_time, 442 &ep->dentry.file.modify_date, 443 &ep->dentry.file.modify_time_cs); 444 exfat_set_entry_time(sbi, ts, 445 &ep->dentry.file.access_tz, 446 &ep->dentry.file.access_time, 447 &ep->dentry.file.access_date, 448 NULL); 449 450 ep = exfat_get_dentry_cached(es, ES_IDX_STREAM); 451 exfat_init_stream_entry(ep, start_clu, size); 452 } 453 454 static void exfat_free_benign_secondary_clusters(struct inode *inode, 455 struct exfat_dentry *ep) 456 { 457 struct super_block *sb = inode->i_sb; 458 struct exfat_chain dir; 459 unsigned int start_clu = 460 le32_to_cpu(ep->dentry.generic_secondary.start_clu); 461 u64 size = le64_to_cpu(ep->dentry.generic_secondary.size); 462 unsigned char flags = ep->dentry.generic_secondary.flags; 463 464 if (!(flags & ALLOC_POSSIBLE) || !start_clu || !size) 465 return; 466 467 exfat_chain_set(&dir, start_clu, 468 EXFAT_B_TO_CLU_ROUND_UP(size, EXFAT_SB(sb)), 469 flags); 470 exfat_free_cluster(inode, &dir); 471 } 472 473 void exfat_init_ext_entry(struct exfat_entry_set_cache *es, int num_entries, 474 struct exfat_uni_name *p_uniname) 475 { 476 int i; 477 unsigned short *uniname = p_uniname->name; 478 struct exfat_dentry *ep; 479 480 es->num_entries = num_entries; 481 ep = exfat_get_dentry_cached(es, ES_IDX_FILE); 482 ep->dentry.file.num_ext = (unsigned char)(num_entries - 1); 483 484 ep = exfat_get_dentry_cached(es, ES_IDX_STREAM); 485 ep->dentry.stream.name_len = p_uniname->name_len; 486 ep->dentry.stream.name_hash = cpu_to_le16(p_uniname->name_hash); 487 488 for (i = ES_IDX_FIRST_FILENAME; i < num_entries; i++) { 489 ep = exfat_get_dentry_cached(es, i); 490 exfat_init_name_entry(ep, uniname); 491 uniname += EXFAT_FILE_NAME_LEN; 492 } 493 494 exfat_update_dir_chksum(es); 495 } 496 497 void exfat_remove_entries(struct inode *inode, struct exfat_entry_set_cache *es, 498 int order) 499 { 500 int i; 501 struct exfat_dentry *ep; 502 503 for (i = order; i < es->num_entries; i++) { 504 ep = exfat_get_dentry_cached(es, i); 505 506 if (exfat_get_entry_type(ep) & TYPE_BENIGN_SEC) 507 exfat_free_benign_secondary_clusters(inode, ep); 508 509 exfat_set_entry_type(ep, TYPE_DELETED); 510 } 511 512 if (order < es->num_entries) 513 es->modified = true; 514 } 515 516 void exfat_update_dir_chksum(struct exfat_entry_set_cache *es) 517 { 518 int chksum_type = CS_DIR_ENTRY, i; 519 unsigned short chksum = 0; 520 struct exfat_dentry *ep; 521 522 for (i = ES_IDX_FILE; i < es->num_entries; i++) { 523 ep = exfat_get_dentry_cached(es, i); 524 chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum, 525 chksum_type); 526 chksum_type = CS_DEFAULT; 527 } 528 ep = exfat_get_dentry_cached(es, ES_IDX_FILE); 529 ep->dentry.file.checksum = cpu_to_le16(chksum); 530 es->modified = true; 531 } 532 533 int exfat_put_dentry_set(struct exfat_entry_set_cache *es, int sync) 534 { 535 int i, err = 0; 536 537 if (es->modified) 538 err = exfat_update_bhs(es->bh, es->num_bh, sync); 539 540 for (i = 0; i < es->num_bh; i++) 541 if (err) 542 bforget(es->bh[i]); 543 else 544 brelse(es->bh[i]); 545 546 if (IS_DYNAMIC_ES(es)) 547 kfree(es->bh); 548 549 return err; 550 } 551 552 static int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir, 553 int entry, sector_t *sector, int *offset) 554 { 555 int ret; 556 unsigned int off, clu = 0; 557 struct exfat_sb_info *sbi = EXFAT_SB(sb); 558 559 off = EXFAT_DEN_TO_B(entry); 560 561 clu = p_dir->dir; 562 ret = exfat_cluster_walk(sb, &clu, EXFAT_B_TO_CLU(off, sbi), p_dir->flags); 563 if (ret) 564 return ret; 565 566 if (clu == EXFAT_EOF_CLUSTER) { 567 exfat_fs_error(sb, 568 "unexpected early break in cluster chain (clu : %u, len : %d)", 569 p_dir->dir, 570 EXFAT_B_TO_CLU(off, sbi)); 571 return -EIO; 572 } 573 574 if (!exfat_test_bitmap(sb, clu)) { 575 exfat_err(sb, "failed to test cluster bit(%u)", clu); 576 return -EIO; 577 } 578 579 /* byte offset in cluster */ 580 off = EXFAT_CLU_OFFSET(off, sbi); 581 582 /* byte offset in sector */ 583 *offset = EXFAT_BLK_OFFSET(off, sb); 584 585 /* sector offset in cluster */ 586 *sector = EXFAT_B_TO_BLK(off, sb); 587 *sector += exfat_cluster_to_sector(sbi, clu); 588 return 0; 589 } 590 591 struct exfat_dentry *exfat_get_dentry(struct super_block *sb, 592 struct exfat_chain *p_dir, int entry, struct buffer_head **bh) 593 { 594 struct exfat_sb_info *sbi = EXFAT_SB(sb); 595 unsigned int sect_per_clus = sbi->sect_per_clus; 596 unsigned int dentries_per_page = EXFAT_B_TO_DEN(PAGE_SIZE); 597 int off; 598 sector_t sec; 599 600 if (p_dir->dir == DIR_DELETED) { 601 exfat_err(sb, "abnormal access to deleted dentry"); 602 return NULL; 603 } 604 605 if (exfat_find_location(sb, p_dir, entry, &sec, &off)) 606 return NULL; 607 608 if (sect_per_clus > 1 && 609 (entry & (dentries_per_page - 1)) == 0) { 610 sector_t ra = sec; 611 blkcnt_t cnt = 0; 612 unsigned int ra_count = sect_per_clus; 613 614 /* Not sector aligned with ra_count, resize ra_count to page size */ 615 if ((sec - sbi->data_start_sector) & (ra_count - 1)) 616 ra_count = PAGE_SIZE >> sb->s_blocksize_bits; 617 618 exfat_blk_readahead(sb, sec, &ra, &cnt, sec + ra_count - 1); 619 } 620 621 *bh = sb_bread(sb, sec); 622 if (!*bh) 623 return NULL; 624 625 return (struct exfat_dentry *)((*bh)->b_data + off); 626 } 627 628 enum exfat_validate_dentry_mode { 629 ES_MODE_GET_FILE_ENTRY, 630 ES_MODE_GET_STRM_ENTRY, 631 ES_MODE_GET_NAME_ENTRY, 632 ES_MODE_GET_CRITICAL_SEC_ENTRY, 633 ES_MODE_GET_BENIGN_SEC_ENTRY, 634 }; 635 636 static bool exfat_validate_entry(unsigned int type, 637 enum exfat_validate_dentry_mode *mode) 638 { 639 if (type == TYPE_UNUSED || type == TYPE_DELETED) 640 return false; 641 642 switch (*mode) { 643 case ES_MODE_GET_FILE_ENTRY: 644 if (type != TYPE_STREAM) 645 return false; 646 *mode = ES_MODE_GET_STRM_ENTRY; 647 break; 648 case ES_MODE_GET_STRM_ENTRY: 649 if (type != TYPE_EXTEND) 650 return false; 651 *mode = ES_MODE_GET_NAME_ENTRY; 652 break; 653 case ES_MODE_GET_NAME_ENTRY: 654 if (type & TYPE_BENIGN_SEC) 655 *mode = ES_MODE_GET_BENIGN_SEC_ENTRY; 656 else if (type != TYPE_EXTEND) 657 return false; 658 break; 659 case ES_MODE_GET_BENIGN_SEC_ENTRY: 660 /* Assume unreconized benign secondary entry */ 661 if (!(type & TYPE_BENIGN_SEC)) 662 return false; 663 break; 664 default: 665 return false; 666 } 667 668 return true; 669 } 670 671 struct exfat_dentry *exfat_get_dentry_cached( 672 struct exfat_entry_set_cache *es, int num) 673 { 674 int off = es->start_off + num * DENTRY_SIZE; 675 struct buffer_head *bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)]; 676 char *p = bh->b_data + EXFAT_BLK_OFFSET(off, es->sb); 677 678 return (struct exfat_dentry *)p; 679 } 680 681 /* 682 * Returns a set of dentries. 683 * 684 * Note It provides a direct pointer to bh->data via exfat_get_dentry_cached(). 685 * User should call exfat_get_dentry_set() after setting 'modified' to apply 686 * changes made in this entry set to the real device. 687 * 688 * in: 689 * sb+p_dir+entry: indicates a file/dir 690 * num_entries: specifies how many dentries should be included. 691 * It will be set to es->num_entries if it is not 0. 692 * If num_entries is 0, es->num_entries will be obtained 693 * from the first dentry. 694 * out: 695 * es: pointer of entry set on success. 696 * return: 697 * 0 on success 698 * -error code on failure 699 */ 700 static int __exfat_get_dentry_set(struct exfat_entry_set_cache *es, 701 struct super_block *sb, struct exfat_chain *p_dir, int entry, 702 unsigned int num_entries) 703 { 704 int ret, i, num_bh; 705 unsigned int off; 706 sector_t sec; 707 struct exfat_sb_info *sbi = EXFAT_SB(sb); 708 struct buffer_head *bh; 709 710 if (p_dir->dir == DIR_DELETED) { 711 exfat_err(sb, "access to deleted dentry"); 712 return -EIO; 713 } 714 715 ret = exfat_find_location(sb, p_dir, entry, &sec, &off); 716 if (ret) 717 return ret; 718 719 memset(es, 0, sizeof(*es)); 720 es->sb = sb; 721 es->modified = false; 722 es->start_off = off; 723 es->bh = es->__bh; 724 725 bh = sb_bread(sb, sec); 726 if (!bh) 727 return -EIO; 728 es->bh[es->num_bh++] = bh; 729 730 if (num_entries == ES_ALL_ENTRIES) { 731 struct exfat_dentry *ep; 732 733 ep = exfat_get_dentry_cached(es, ES_IDX_FILE); 734 if (ep->type != EXFAT_FILE) { 735 brelse(bh); 736 return -EIO; 737 } 738 739 num_entries = ep->dentry.file.num_ext + 1; 740 } 741 742 es->num_entries = num_entries; 743 744 num_bh = EXFAT_B_TO_BLK_ROUND_UP(off + num_entries * DENTRY_SIZE, sb); 745 if (num_bh > ARRAY_SIZE(es->__bh)) { 746 es->bh = kmalloc_objs(*es->bh, num_bh, GFP_NOFS); 747 if (!es->bh) { 748 brelse(bh); 749 return -ENOMEM; 750 } 751 es->bh[0] = bh; 752 } 753 754 for (i = 1; i < num_bh; i++) { 755 /* get the next sector */ 756 if (exfat_is_last_sector_in_cluster(sbi, sec)) { 757 unsigned int clu = exfat_sector_to_cluster(sbi, sec); 758 759 if (exfat_cluster_walk(sb, &clu, 1, p_dir->flags)) 760 goto put_es; 761 sec = exfat_cluster_to_sector(sbi, clu); 762 } else { 763 sec++; 764 } 765 766 bh = sb_bread(sb, sec); 767 if (!bh) 768 goto put_es; 769 es->bh[es->num_bh++] = bh; 770 } 771 772 return 0; 773 774 put_es: 775 exfat_put_dentry_set(es, false); 776 return -EIO; 777 } 778 779 int exfat_get_dentry_set(struct exfat_entry_set_cache *es, 780 struct super_block *sb, struct exfat_chain *p_dir, 781 int entry, unsigned int num_entries) 782 { 783 int ret, i; 784 struct exfat_dentry *ep; 785 enum exfat_validate_dentry_mode mode = ES_MODE_GET_FILE_ENTRY; 786 787 ret = __exfat_get_dentry_set(es, sb, p_dir, entry, num_entries); 788 if (ret < 0) 789 return ret; 790 791 /* validate cached dentries */ 792 for (i = ES_IDX_STREAM; i < es->num_entries; i++) { 793 ep = exfat_get_dentry_cached(es, i); 794 if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode)) 795 goto put_es; 796 } 797 return 0; 798 799 put_es: 800 exfat_put_dentry_set(es, false); 801 return -EIO; 802 } 803 804 static int exfat_validate_empty_dentry_set(struct exfat_entry_set_cache *es) 805 { 806 struct exfat_dentry *ep; 807 struct buffer_head *bh; 808 int i, off; 809 bool unused_hit = false; 810 811 /* 812 * ONLY UNUSED OR DELETED DENTRIES ARE ALLOWED: 813 * Although it violates the specification for a deleted entry to 814 * follow an unused entry, some exFAT implementations could work 815 * like this. Therefore, to improve compatibility, let's allow it. 816 */ 817 for (i = 0; i < es->num_entries; i++) { 818 ep = exfat_get_dentry_cached(es, i); 819 if (ep->type == EXFAT_UNUSED) { 820 unused_hit = true; 821 } else if (!IS_EXFAT_DELETED(ep->type)) { 822 if (unused_hit) 823 goto err_used_follow_unused; 824 i++; 825 goto count_skip_entries; 826 } 827 } 828 829 return 0; 830 831 err_used_follow_unused: 832 off = es->start_off + (i << DENTRY_SIZE_BITS); 833 bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)]; 834 835 exfat_fs_error(es->sb, 836 "in sector %lld, dentry %d should be unused, but 0x%x", 837 bh->b_blocknr, off >> DENTRY_SIZE_BITS, ep->type); 838 839 return -EIO; 840 841 count_skip_entries: 842 es->num_entries = EXFAT_B_TO_DEN(EXFAT_BLK_TO_B(es->num_bh, es->sb) - es->start_off); 843 for (; i < es->num_entries; i++) { 844 ep = exfat_get_dentry_cached(es, i); 845 if (IS_EXFAT_DELETED(ep->type)) 846 break; 847 } 848 849 return i; 850 } 851 852 /* 853 * Get an empty dentry set. 854 * 855 * in: 856 * sb+p_dir+entry: indicates the empty dentry location 857 * num_entries: specifies how many empty dentries should be included. 858 * out: 859 * es: pointer of empty dentry set on success. 860 * return: 861 * 0 : on success 862 * >0 : the dentries are not empty, the return value is the number of 863 * dentries to be skipped for the next lookup. 864 * <0 : on failure 865 */ 866 int exfat_get_empty_dentry_set(struct exfat_entry_set_cache *es, 867 struct super_block *sb, struct exfat_chain *p_dir, 868 int entry, unsigned int num_entries) 869 { 870 int ret; 871 872 ret = __exfat_get_dentry_set(es, sb, p_dir, entry, num_entries); 873 if (ret < 0) 874 return ret; 875 876 ret = exfat_validate_empty_dentry_set(es); 877 if (ret) 878 exfat_put_dentry_set(es, false); 879 880 return ret; 881 } 882 883 static inline void exfat_reset_empty_hint(struct exfat_hint_femp *hint_femp) 884 { 885 hint_femp->eidx = EXFAT_HINT_NONE; 886 hint_femp->count = 0; 887 } 888 889 static inline void exfat_set_empty_hint(struct exfat_inode_info *ei, 890 struct exfat_hint_femp *candi_empty, struct exfat_chain *clu, 891 int dentry, int num_entries, int entry_type) 892 { 893 if (ei->hint_femp.eidx == EXFAT_HINT_NONE || 894 ei->hint_femp.eidx > dentry) { 895 int total_entries = EXFAT_B_TO_DEN(i_size_read(&ei->vfs_inode)); 896 897 if (candi_empty->count == 0) { 898 candi_empty->cur = *clu; 899 candi_empty->eidx = dentry; 900 } 901 902 if (entry_type == TYPE_UNUSED) 903 candi_empty->count += total_entries - dentry; 904 else 905 candi_empty->count++; 906 907 if (candi_empty->count == num_entries || 908 candi_empty->count + candi_empty->eidx == total_entries) 909 ei->hint_femp = *candi_empty; 910 } 911 } 912 913 enum { 914 DIRENT_STEP_FILE, 915 DIRENT_STEP_STRM, 916 DIRENT_STEP_NAME, 917 DIRENT_STEP_SECD, 918 }; 919 920 /* 921 * @ei: inode info of parent directory 922 * @p_dir: directory structure of parent directory 923 * @num_entries:entry size of p_uniname 924 * @hint_opt: If p_uniname is found, filled with optimized dir/entry 925 * for traversing cluster chain. 926 * @return: 927 * >= 0: file directory entry position where the name exists 928 * -ENOENT: entry with the name does not exist 929 * -EIO: I/O error 930 */ 931 int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei, 932 struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname, 933 struct exfat_hint *hint_opt) 934 { 935 int i, rewind = 0, dentry = 0, end_eidx = 0, num_ext = 0, len; 936 int order, step, name_len = 0; 937 int dentries_per_clu; 938 unsigned int entry_type; 939 unsigned short *uniname = NULL; 940 struct exfat_chain clu; 941 struct exfat_hint *hint_stat = &ei->hint_stat; 942 struct exfat_hint_femp candi_empty; 943 struct exfat_sb_info *sbi = EXFAT_SB(sb); 944 int num_entries = exfat_calc_num_entries(p_uniname); 945 unsigned int clu_count = 0; 946 947 if (num_entries < 0) 948 return num_entries; 949 950 dentries_per_clu = sbi->dentries_per_clu; 951 952 exfat_chain_dup(&clu, p_dir); 953 954 if (hint_stat->eidx) { 955 clu.dir = hint_stat->clu; 956 dentry = hint_stat->eidx; 957 end_eidx = dentry; 958 } 959 960 exfat_reset_empty_hint(&ei->hint_femp); 961 962 rewind: 963 order = 0; 964 step = DIRENT_STEP_FILE; 965 exfat_reset_empty_hint(&candi_empty); 966 967 while (clu.dir != EXFAT_EOF_CLUSTER) { 968 i = dentry & (dentries_per_clu - 1); 969 for (; i < dentries_per_clu; i++, dentry++) { 970 struct exfat_dentry *ep; 971 struct buffer_head *bh; 972 973 if (rewind && dentry == end_eidx) 974 goto not_found; 975 976 ep = exfat_get_dentry(sb, &clu, i, &bh); 977 if (!ep) 978 return -EIO; 979 980 entry_type = exfat_get_entry_type(ep); 981 982 if (entry_type == TYPE_UNUSED || 983 entry_type == TYPE_DELETED) { 984 step = DIRENT_STEP_FILE; 985 986 exfat_set_empty_hint(ei, &candi_empty, &clu, 987 dentry, num_entries, 988 entry_type); 989 990 brelse(bh); 991 if (entry_type == TYPE_UNUSED) 992 goto not_found; 993 continue; 994 } 995 996 exfat_reset_empty_hint(&candi_empty); 997 998 if (entry_type == TYPE_FILE || entry_type == TYPE_DIR) { 999 step = DIRENT_STEP_FILE; 1000 hint_opt->clu = clu.dir; 1001 hint_opt->eidx = i; 1002 num_ext = ep->dentry.file.num_ext; 1003 step = DIRENT_STEP_STRM; 1004 brelse(bh); 1005 continue; 1006 } 1007 1008 if (entry_type == TYPE_STREAM) { 1009 u16 name_hash; 1010 1011 if (step != DIRENT_STEP_STRM) { 1012 step = DIRENT_STEP_FILE; 1013 brelse(bh); 1014 continue; 1015 } 1016 step = DIRENT_STEP_FILE; 1017 name_hash = le16_to_cpu( 1018 ep->dentry.stream.name_hash); 1019 if (p_uniname->name_hash == name_hash && 1020 p_uniname->name_len == 1021 ep->dentry.stream.name_len) { 1022 step = DIRENT_STEP_NAME; 1023 order = 1; 1024 name_len = 0; 1025 } 1026 brelse(bh); 1027 continue; 1028 } 1029 1030 brelse(bh); 1031 if (entry_type == TYPE_EXTEND) { 1032 unsigned short entry_uniname[16], unichar; 1033 1034 if (step != DIRENT_STEP_NAME || 1035 name_len >= MAX_NAME_LENGTH) { 1036 step = DIRENT_STEP_FILE; 1037 continue; 1038 } 1039 1040 if (++order == 2) 1041 uniname = p_uniname->name; 1042 else 1043 uniname += EXFAT_FILE_NAME_LEN; 1044 1045 len = exfat_extract_uni_name(ep, entry_uniname); 1046 name_len += len; 1047 1048 unichar = *(uniname+len); 1049 *(uniname+len) = 0x0; 1050 1051 if (exfat_uniname_ncmp(sb, uniname, 1052 entry_uniname, len)) { 1053 step = DIRENT_STEP_FILE; 1054 } else if (p_uniname->name_len == name_len) { 1055 if (order == num_ext) 1056 goto found; 1057 step = DIRENT_STEP_SECD; 1058 } 1059 1060 *(uniname+len) = unichar; 1061 continue; 1062 } 1063 1064 if (entry_type & 1065 (TYPE_CRITICAL_SEC | TYPE_BENIGN_SEC)) { 1066 if (step == DIRENT_STEP_SECD) { 1067 if (++order == num_ext) 1068 goto found; 1069 continue; 1070 } 1071 } 1072 step = DIRENT_STEP_FILE; 1073 } 1074 1075 if (exfat_chain_advance(sb, &clu, 1)) 1076 return -EIO; 1077 1078 /* break if the cluster chain includes a loop */ 1079 if (unlikely(++clu_count > EXFAT_DATA_CLUSTER_COUNT(sbi))) 1080 goto not_found; 1081 } 1082 1083 not_found: 1084 /* 1085 * We started at not 0 index,so we should try to find target 1086 * from 0 index to the index we started at. 1087 */ 1088 if (!rewind && end_eidx) { 1089 rewind = 1; 1090 dentry = 0; 1091 clu.dir = p_dir->dir; 1092 goto rewind; 1093 } 1094 1095 /* 1096 * set the EXFAT_EOF_CLUSTER flag to avoid search 1097 * from the beginning again when allocated a new cluster 1098 */ 1099 if (ei->hint_femp.eidx == EXFAT_HINT_NONE) { 1100 ei->hint_femp.cur.dir = EXFAT_EOF_CLUSTER; 1101 ei->hint_femp.eidx = p_dir->size * dentries_per_clu; 1102 ei->hint_femp.count = 0; 1103 } 1104 1105 /* initialized hint_stat */ 1106 hint_stat->clu = p_dir->dir; 1107 hint_stat->eidx = 0; 1108 return -ENOENT; 1109 1110 found: 1111 /* next dentry we'll find is out of this cluster */ 1112 if (!((dentry + 1) & (dentries_per_clu - 1))) { 1113 int ret = 0; 1114 1115 ret = exfat_chain_advance(sb, &clu, 1); 1116 1117 if (ret || clu.dir == EXFAT_EOF_CLUSTER) { 1118 /* just initialized hint_stat */ 1119 hint_stat->clu = p_dir->dir; 1120 hint_stat->eidx = 0; 1121 return (dentry - num_ext); 1122 } 1123 } 1124 1125 hint_stat->clu = clu.dir; 1126 hint_stat->eidx = dentry + 1; 1127 return dentry - num_ext; 1128 } 1129 1130 int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir) 1131 { 1132 int i, count = 0; 1133 int dentries_per_clu; 1134 unsigned int entry_type; 1135 unsigned int clu_count = 0; 1136 struct exfat_chain clu; 1137 struct exfat_dentry *ep; 1138 struct exfat_sb_info *sbi = EXFAT_SB(sb); 1139 struct buffer_head *bh; 1140 1141 dentries_per_clu = sbi->dentries_per_clu; 1142 1143 exfat_chain_dup(&clu, p_dir); 1144 1145 while (clu.dir != EXFAT_EOF_CLUSTER) { 1146 for (i = 0; i < dentries_per_clu; i++) { 1147 ep = exfat_get_dentry(sb, &clu, i, &bh); 1148 if (!ep) 1149 return -EIO; 1150 entry_type = exfat_get_entry_type(ep); 1151 brelse(bh); 1152 1153 if (entry_type == TYPE_UNUSED) 1154 return count; 1155 if (entry_type != TYPE_DIR) 1156 continue; 1157 count++; 1158 } 1159 1160 if (exfat_chain_advance(sb, &clu, 1)) 1161 return -EIO; 1162 1163 if (unlikely(++clu_count > sbi->used_clusters)) { 1164 exfat_fs_error(sb, "FAT or bitmap is corrupted"); 1165 return -EIO; 1166 } 1167 } 1168 1169 return count; 1170 } 1171 1172 static int exfat_get_volume_label_dentry(struct super_block *sb, 1173 struct exfat_entry_set_cache *es) 1174 { 1175 int i; 1176 int dentry = 0; 1177 unsigned int type; 1178 struct exfat_sb_info *sbi = EXFAT_SB(sb); 1179 struct exfat_hint_femp hint_femp; 1180 struct exfat_inode_info *ei = EXFAT_I(sb->s_root->d_inode); 1181 struct exfat_chain clu; 1182 struct exfat_dentry *ep; 1183 struct buffer_head *bh; 1184 1185 hint_femp.eidx = EXFAT_HINT_NONE; 1186 exfat_chain_set(&clu, sbi->root_dir, 0, ALLOC_FAT_CHAIN); 1187 1188 while (clu.dir != EXFAT_EOF_CLUSTER) { 1189 for (i = 0; i < sbi->dentries_per_clu; i++, dentry++) { 1190 ep = exfat_get_dentry(sb, &clu, i, &bh); 1191 if (!ep) 1192 return -EIO; 1193 1194 type = exfat_get_entry_type(ep); 1195 if (hint_femp.eidx == EXFAT_HINT_NONE) { 1196 if (type == TYPE_DELETED || type == TYPE_UNUSED) { 1197 hint_femp.cur = clu; 1198 hint_femp.eidx = dentry; 1199 hint_femp.count = 1; 1200 } 1201 } 1202 1203 if (type == TYPE_UNUSED) { 1204 brelse(bh); 1205 goto not_found; 1206 } 1207 1208 if (type != TYPE_VOLUME) { 1209 brelse(bh); 1210 continue; 1211 } 1212 1213 memset(es, 0, sizeof(*es)); 1214 es->sb = sb; 1215 es->bh = es->__bh; 1216 es->bh[0] = bh; 1217 es->num_bh = 1; 1218 es->start_off = EXFAT_DEN_TO_B(i) % sb->s_blocksize; 1219 1220 return 0; 1221 } 1222 1223 if (exfat_get_next_cluster(sb, &(clu.dir))) 1224 return -EIO; 1225 } 1226 1227 not_found: 1228 if (hint_femp.eidx == EXFAT_HINT_NONE) { 1229 hint_femp.cur.dir = EXFAT_EOF_CLUSTER; 1230 hint_femp.eidx = dentry; 1231 hint_femp.count = 0; 1232 } 1233 1234 ei->hint_femp = hint_femp; 1235 1236 return -ENOENT; 1237 } 1238 1239 int exfat_read_volume_label(struct super_block *sb, struct exfat_uni_name *label_out) 1240 { 1241 int ret, i; 1242 struct exfat_sb_info *sbi = EXFAT_SB(sb); 1243 struct exfat_entry_set_cache es; 1244 struct exfat_dentry *ep; 1245 1246 mutex_lock(&sbi->s_lock); 1247 1248 memset(label_out, 0, sizeof(*label_out)); 1249 ret = exfat_get_volume_label_dentry(sb, &es); 1250 if (ret < 0) { 1251 /* 1252 * ENOENT signifies that a volume label dentry doesn't exist 1253 * We will treat this as an empty volume label and not fail. 1254 */ 1255 if (ret == -ENOENT) 1256 ret = 0; 1257 1258 goto unlock; 1259 } 1260 1261 ep = exfat_get_dentry_cached(&es, 0); 1262 label_out->name_len = ep->dentry.volume_label.char_count; 1263 if (label_out->name_len > EXFAT_VOLUME_LABEL_LEN) { 1264 ret = -EIO; 1265 exfat_put_dentry_set(&es, false); 1266 goto unlock; 1267 } 1268 1269 for (i = 0; i < label_out->name_len; i++) 1270 label_out->name[i] = le16_to_cpu(ep->dentry.volume_label.volume_label[i]); 1271 1272 exfat_put_dentry_set(&es, false); 1273 unlock: 1274 mutex_unlock(&sbi->s_lock); 1275 return ret; 1276 } 1277 1278 int exfat_write_volume_label(struct super_block *sb, 1279 struct exfat_uni_name *label) 1280 { 1281 int ret, i; 1282 struct exfat_sb_info *sbi = EXFAT_SB(sb); 1283 struct inode *root_inode = sb->s_root->d_inode; 1284 struct exfat_entry_set_cache es; 1285 struct exfat_chain clu; 1286 struct exfat_dentry *ep; 1287 1288 if (label->name_len > EXFAT_VOLUME_LABEL_LEN) 1289 return -EINVAL; 1290 1291 mutex_lock(&sbi->s_lock); 1292 1293 ret = exfat_get_volume_label_dentry(sb, &es); 1294 if (ret == -ENOENT) { 1295 if (label->name_len == 0) { 1296 /* No volume label dentry, no need to clear */ 1297 ret = 0; 1298 goto unlock; 1299 } 1300 1301 ret = exfat_find_empty_entry(root_inode, &clu, 1, &es); 1302 } 1303 1304 if (ret < 0) 1305 goto unlock; 1306 1307 ep = exfat_get_dentry_cached(&es, 0); 1308 1309 if (label->name_len == 0 && ep->dentry.volume_label.char_count == 0) { 1310 /* volume label had been cleared */ 1311 exfat_put_dentry_set(&es, 0); 1312 goto unlock; 1313 } 1314 1315 memset(ep, 0, sizeof(*ep)); 1316 ep->type = EXFAT_VOLUME; 1317 1318 for (i = 0; i < label->name_len; i++) 1319 ep->dentry.volume_label.volume_label[i] = 1320 cpu_to_le16(label->name[i]); 1321 1322 ep->dentry.volume_label.char_count = label->name_len; 1323 es.modified = true; 1324 1325 ret = exfat_put_dentry_set(&es, IS_DIRSYNC(root_inode)); 1326 1327 unlock: 1328 mutex_unlock(&sbi->s_lock); 1329 return ret; 1330 } 1331