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