1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd. 4 */ 5 6 #include <linux/slab.h> 7 #include <linux/compat.h> 8 #include <linux/bio.h> 9 #include <linux/buffer_head.h> 10 11 #include "exfat_raw.h" 12 #include "exfat_fs.h" 13 14 static int exfat_extract_uni_name(struct exfat_dentry *ep, 15 unsigned short *uniname) 16 { 17 int i, len = 0; 18 19 for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) { 20 *uniname = le16_to_cpu(ep->dentry.name.unicode_0_14[i]); 21 if (*uniname == 0x0) 22 return len; 23 uniname++; 24 len++; 25 } 26 27 *uniname = 0x0; 28 return len; 29 30 } 31 32 static int exfat_get_uniname_from_ext_entry(struct super_block *sb, 33 struct exfat_chain *p_dir, int entry, unsigned short *uniname) 34 { 35 int i, err; 36 struct exfat_entry_set_cache es; 37 unsigned int uni_len = 0, len; 38 39 err = exfat_get_dentry_set(&es, sb, p_dir, entry, ES_ALL_ENTRIES); 40 if (err) 41 return err; 42 43 /* 44 * First entry : file entry 45 * Second entry : stream-extension entry 46 * Third entry : first file-name entry 47 * So, the index of first file-name dentry should start from 2. 48 */ 49 for (i = ES_IDX_FIRST_FILENAME; i < es.num_entries; i++) { 50 struct exfat_dentry *ep = exfat_get_dentry_cached(&es, i); 51 52 /* end of name entry */ 53 if (exfat_get_entry_type(ep) != TYPE_EXTEND) 54 break; 55 56 len = exfat_extract_uni_name(ep, uniname); 57 uni_len += len; 58 if (len != EXFAT_FILE_NAME_LEN || uni_len >= MAX_NAME_LENGTH) 59 break; 60 uniname += EXFAT_FILE_NAME_LEN; 61 } 62 63 exfat_put_dentry_set(&es, false); 64 return 0; 65 } 66 67 /* read a directory entry from the opened directory */ 68 static int exfat_readdir(struct inode *inode, loff_t *cpos, struct exfat_dir_entry *dir_entry) 69 { 70 int i, dentries_per_clu, num_ext, err; 71 unsigned int type, clu_offset, max_dentries; 72 struct exfat_chain dir, clu; 73 struct exfat_uni_name uni_name; 74 struct exfat_dentry *ep; 75 struct super_block *sb = inode->i_sb; 76 struct exfat_sb_info *sbi = EXFAT_SB(sb); 77 struct exfat_inode_info *ei = EXFAT_I(inode); 78 unsigned int dentry = EXFAT_B_TO_DEN(*cpos) & 0xFFFFFFFF; 79 struct buffer_head *bh; 80 81 /* check if the given file ID is opened */ 82 if (ei->type != TYPE_DIR) 83 return -EPERM; 84 85 if (ei->entry == -1) 86 exfat_chain_set(&dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN); 87 else 88 exfat_chain_set(&dir, ei->start_clu, 89 EXFAT_B_TO_CLU(i_size_read(inode), sbi), ei->flags); 90 91 dentries_per_clu = sbi->dentries_per_clu; 92 max_dentries = (unsigned int)min_t(u64, MAX_EXFAT_DENTRIES, 93 (u64)EXFAT_CLU_TO_DEN(sbi->num_clusters, sbi)); 94 95 clu_offset = EXFAT_DEN_TO_CLU(dentry, sbi); 96 exfat_chain_dup(&clu, &dir); 97 98 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 99 clu.dir += clu_offset; 100 clu.size -= clu_offset; 101 } else { 102 /* hint_information */ 103 if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER && 104 ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) { 105 clu_offset -= ei->hint_bmap.off; 106 clu.dir = ei->hint_bmap.clu; 107 } 108 109 while (clu_offset > 0 && clu.dir != EXFAT_EOF_CLUSTER) { 110 if (exfat_get_next_cluster(sb, &(clu.dir))) 111 return -EIO; 112 113 clu_offset--; 114 } 115 } 116 117 while (clu.dir != EXFAT_EOF_CLUSTER && dentry < max_dentries) { 118 i = dentry & (dentries_per_clu - 1); 119 120 for ( ; i < dentries_per_clu; i++, dentry++) { 121 ep = exfat_get_dentry(sb, &clu, i, &bh); 122 if (!ep) 123 return -EIO; 124 125 type = exfat_get_entry_type(ep); 126 if (type == TYPE_UNUSED) { 127 brelse(bh); 128 break; 129 } 130 131 if (type != TYPE_FILE && type != TYPE_DIR) { 132 brelse(bh); 133 continue; 134 } 135 136 num_ext = ep->dentry.file.num_ext; 137 dir_entry->attr = le16_to_cpu(ep->dentry.file.attr); 138 exfat_get_entry_time(sbi, &dir_entry->crtime, 139 ep->dentry.file.create_tz, 140 ep->dentry.file.create_time, 141 ep->dentry.file.create_date, 142 ep->dentry.file.create_time_cs); 143 exfat_get_entry_time(sbi, &dir_entry->mtime, 144 ep->dentry.file.modify_tz, 145 ep->dentry.file.modify_time, 146 ep->dentry.file.modify_date, 147 ep->dentry.file.modify_time_cs); 148 exfat_get_entry_time(sbi, &dir_entry->atime, 149 ep->dentry.file.access_tz, 150 ep->dentry.file.access_time, 151 ep->dentry.file.access_date, 152 0); 153 154 *uni_name.name = 0x0; 155 err = exfat_get_uniname_from_ext_entry(sb, &clu, i, 156 uni_name.name); 157 if (err) { 158 brelse(bh); 159 continue; 160 } 161 exfat_utf16_to_nls(sb, &uni_name, 162 dir_entry->namebuf.lfn, 163 dir_entry->namebuf.lfnbuf_len); 164 brelse(bh); 165 166 ep = exfat_get_dentry(sb, &clu, i + 1, &bh); 167 if (!ep) 168 return -EIO; 169 dir_entry->size = 170 le64_to_cpu(ep->dentry.stream.valid_size); 171 dir_entry->entry = dentry; 172 brelse(bh); 173 174 ei->hint_bmap.off = EXFAT_DEN_TO_CLU(dentry, sbi); 175 ei->hint_bmap.clu = clu.dir; 176 177 *cpos = EXFAT_DEN_TO_B(dentry + 1 + num_ext); 178 return 0; 179 } 180 181 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 182 if (--clu.size > 0) 183 clu.dir++; 184 else 185 clu.dir = EXFAT_EOF_CLUSTER; 186 } else { 187 if (exfat_get_next_cluster(sb, &(clu.dir))) 188 return -EIO; 189 } 190 } 191 192 dir_entry->namebuf.lfn[0] = '\0'; 193 *cpos = EXFAT_DEN_TO_B(dentry); 194 return 0; 195 } 196 197 static void exfat_init_namebuf(struct exfat_dentry_namebuf *nb) 198 { 199 nb->lfn = NULL; 200 nb->lfnbuf_len = 0; 201 } 202 203 static int exfat_alloc_namebuf(struct exfat_dentry_namebuf *nb) 204 { 205 nb->lfn = __getname(); 206 if (!nb->lfn) 207 return -ENOMEM; 208 nb->lfnbuf_len = MAX_VFSNAME_BUF_SIZE; 209 return 0; 210 } 211 212 static void exfat_free_namebuf(struct exfat_dentry_namebuf *nb) 213 { 214 if (!nb->lfn) 215 return; 216 217 __putname(nb->lfn); 218 exfat_init_namebuf(nb); 219 } 220 221 /* 222 * Before calling dir_emit*(), sbi->s_lock should be released 223 * because page fault can occur in dir_emit*(). 224 */ 225 #define ITER_POS_FILLED_DOTS (2) 226 static int exfat_iterate(struct file *file, struct dir_context *ctx) 227 { 228 struct inode *inode = file_inode(file); 229 struct super_block *sb = inode->i_sb; 230 struct inode *tmp; 231 struct exfat_dir_entry de; 232 struct exfat_dentry_namebuf *nb = &(de.namebuf); 233 struct exfat_inode_info *ei = EXFAT_I(inode); 234 unsigned long inum; 235 loff_t cpos, i_pos; 236 int err = 0, fake_offset = 0; 237 238 exfat_init_namebuf(nb); 239 240 cpos = ctx->pos; 241 if (!dir_emit_dots(file, ctx)) 242 goto out; 243 244 if (ctx->pos == ITER_POS_FILLED_DOTS) { 245 cpos = 0; 246 fake_offset = 1; 247 } 248 249 cpos = round_up(cpos, DENTRY_SIZE); 250 251 /* name buffer should be allocated before use */ 252 err = exfat_alloc_namebuf(nb); 253 if (err) 254 goto out; 255 get_new: 256 mutex_lock(&EXFAT_SB(sb)->s_lock); 257 258 if (ei->flags == ALLOC_NO_FAT_CHAIN && cpos >= i_size_read(inode)) 259 goto end_of_dir; 260 261 err = exfat_readdir(inode, &cpos, &de); 262 if (err) { 263 /* 264 * At least we tried to read a sector. 265 * Move cpos to next sector position (should be aligned). 266 */ 267 if (err == -EIO) { 268 cpos += 1 << (sb->s_blocksize_bits); 269 cpos &= ~(sb->s_blocksize - 1); 270 } 271 272 err = -EIO; 273 goto end_of_dir; 274 } 275 276 if (!nb->lfn[0]) 277 goto end_of_dir; 278 279 i_pos = ((loff_t)ei->start_clu << 32) | (de.entry & 0xffffffff); 280 tmp = exfat_iget(sb, i_pos); 281 if (tmp) { 282 inum = tmp->i_ino; 283 iput(tmp); 284 } else { 285 inum = iunique(sb, EXFAT_ROOT_INO); 286 } 287 288 mutex_unlock(&EXFAT_SB(sb)->s_lock); 289 if (!dir_emit(ctx, nb->lfn, strlen(nb->lfn), inum, 290 (de.attr & EXFAT_ATTR_SUBDIR) ? DT_DIR : DT_REG)) 291 goto out; 292 ctx->pos = cpos; 293 goto get_new; 294 295 end_of_dir: 296 if (!cpos && fake_offset) 297 cpos = ITER_POS_FILLED_DOTS; 298 ctx->pos = cpos; 299 mutex_unlock(&EXFAT_SB(sb)->s_lock); 300 out: 301 /* 302 * To improve performance, free namebuf after unlock sb_lock. 303 * If namebuf is not allocated, this function do nothing 304 */ 305 exfat_free_namebuf(nb); 306 return err; 307 } 308 309 WRAP_DIR_ITER(exfat_iterate) // FIXME! 310 const struct file_operations exfat_dir_operations = { 311 .llseek = generic_file_llseek, 312 .read = generic_read_dir, 313 .iterate_shared = shared_exfat_iterate, 314 .unlocked_ioctl = exfat_ioctl, 315 #ifdef CONFIG_COMPAT 316 .compat_ioctl = exfat_compat_ioctl, 317 #endif 318 .fsync = exfat_file_fsync, 319 }; 320 321 int exfat_alloc_new_dir(struct inode *inode, struct exfat_chain *clu) 322 { 323 int ret; 324 325 exfat_chain_set(clu, EXFAT_EOF_CLUSTER, 0, ALLOC_NO_FAT_CHAIN); 326 327 ret = exfat_alloc_cluster(inode, 1, clu, IS_DIRSYNC(inode)); 328 if (ret) 329 return ret; 330 331 return exfat_zeroed_cluster(inode, clu->dir); 332 } 333 334 int exfat_calc_num_entries(struct exfat_uni_name *p_uniname) 335 { 336 int len; 337 338 len = p_uniname->name_len; 339 if (len == 0) 340 return -EINVAL; 341 342 /* 1 file entry + 1 stream entry + name entries */ 343 return ES_ENTRY_NUM(len); 344 } 345 346 unsigned int exfat_get_entry_type(struct exfat_dentry *ep) 347 { 348 if (ep->type == EXFAT_UNUSED) 349 return TYPE_UNUSED; 350 if (IS_EXFAT_DELETED(ep->type)) 351 return TYPE_DELETED; 352 if (ep->type == EXFAT_INVAL) 353 return TYPE_INVALID; 354 if (IS_EXFAT_CRITICAL_PRI(ep->type)) { 355 if (ep->type == EXFAT_BITMAP) 356 return TYPE_BITMAP; 357 if (ep->type == EXFAT_UPCASE) 358 return TYPE_UPCASE; 359 if (ep->type == EXFAT_VOLUME) 360 return TYPE_VOLUME; 361 if (ep->type == EXFAT_FILE) { 362 if (le16_to_cpu(ep->dentry.file.attr) & EXFAT_ATTR_SUBDIR) 363 return TYPE_DIR; 364 return TYPE_FILE; 365 } 366 return TYPE_CRITICAL_PRI; 367 } 368 if (IS_EXFAT_BENIGN_PRI(ep->type)) { 369 if (ep->type == EXFAT_GUID) 370 return TYPE_GUID; 371 if (ep->type == EXFAT_PADDING) 372 return TYPE_PADDING; 373 if (ep->type == EXFAT_ACLTAB) 374 return TYPE_ACLTAB; 375 return TYPE_BENIGN_PRI; 376 } 377 if (IS_EXFAT_CRITICAL_SEC(ep->type)) { 378 if (ep->type == EXFAT_STREAM) 379 return TYPE_STREAM; 380 if (ep->type == EXFAT_NAME) 381 return TYPE_EXTEND; 382 if (ep->type == EXFAT_ACL) 383 return TYPE_ACL; 384 return TYPE_CRITICAL_SEC; 385 } 386 387 if (ep->type == EXFAT_VENDOR_EXT) 388 return TYPE_VENDOR_EXT; 389 if (ep->type == EXFAT_VENDOR_ALLOC) 390 return TYPE_VENDOR_ALLOC; 391 392 return TYPE_BENIGN_SEC; 393 } 394 395 static void exfat_set_entry_type(struct exfat_dentry *ep, unsigned int type) 396 { 397 if (type == TYPE_UNUSED) { 398 ep->type = EXFAT_UNUSED; 399 } else if (type == TYPE_DELETED) { 400 ep->type &= EXFAT_DELETE; 401 } else if (type == TYPE_STREAM) { 402 ep->type = EXFAT_STREAM; 403 } else if (type == TYPE_EXTEND) { 404 ep->type = EXFAT_NAME; 405 } else if (type == TYPE_BITMAP) { 406 ep->type = EXFAT_BITMAP; 407 } else if (type == TYPE_UPCASE) { 408 ep->type = EXFAT_UPCASE; 409 } else if (type == TYPE_VOLUME) { 410 ep->type = EXFAT_VOLUME; 411 } else if (type == TYPE_DIR) { 412 ep->type = EXFAT_FILE; 413 ep->dentry.file.attr = cpu_to_le16(EXFAT_ATTR_SUBDIR); 414 } else if (type == TYPE_FILE) { 415 ep->type = EXFAT_FILE; 416 ep->dentry.file.attr = cpu_to_le16(EXFAT_ATTR_ARCHIVE); 417 } 418 } 419 420 static void exfat_init_stream_entry(struct exfat_dentry *ep, 421 unsigned int start_clu, unsigned long long size) 422 { 423 exfat_set_entry_type(ep, TYPE_STREAM); 424 if (size == 0) 425 ep->dentry.stream.flags = ALLOC_FAT_CHAIN; 426 else 427 ep->dentry.stream.flags = ALLOC_NO_FAT_CHAIN; 428 ep->dentry.stream.start_clu = cpu_to_le32(start_clu); 429 ep->dentry.stream.valid_size = cpu_to_le64(size); 430 ep->dentry.stream.size = cpu_to_le64(size); 431 } 432 433 static void exfat_init_name_entry(struct exfat_dentry *ep, 434 unsigned short *uniname) 435 { 436 int i; 437 438 exfat_set_entry_type(ep, TYPE_EXTEND); 439 ep->dentry.name.flags = 0x0; 440 441 for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) { 442 if (*uniname != 0x0) { 443 ep->dentry.name.unicode_0_14[i] = cpu_to_le16(*uniname); 444 uniname++; 445 } else { 446 ep->dentry.name.unicode_0_14[i] = 0x0; 447 } 448 } 449 } 450 451 void exfat_init_dir_entry(struct exfat_entry_set_cache *es, 452 unsigned int type, unsigned int start_clu, 453 unsigned long long size, struct timespec64 *ts) 454 { 455 struct super_block *sb = es->sb; 456 struct exfat_sb_info *sbi = EXFAT_SB(sb); 457 struct exfat_dentry *ep; 458 459 ep = exfat_get_dentry_cached(es, ES_IDX_FILE); 460 exfat_set_entry_type(ep, type); 461 exfat_set_entry_time(sbi, ts, 462 &ep->dentry.file.create_tz, 463 &ep->dentry.file.create_time, 464 &ep->dentry.file.create_date, 465 &ep->dentry.file.create_time_cs); 466 exfat_set_entry_time(sbi, ts, 467 &ep->dentry.file.modify_tz, 468 &ep->dentry.file.modify_time, 469 &ep->dentry.file.modify_date, 470 &ep->dentry.file.modify_time_cs); 471 exfat_set_entry_time(sbi, ts, 472 &ep->dentry.file.access_tz, 473 &ep->dentry.file.access_time, 474 &ep->dentry.file.access_date, 475 NULL); 476 477 ep = exfat_get_dentry_cached(es, ES_IDX_STREAM); 478 exfat_init_stream_entry(ep, start_clu, size); 479 } 480 481 static void exfat_free_benign_secondary_clusters(struct inode *inode, 482 struct exfat_dentry *ep) 483 { 484 struct super_block *sb = inode->i_sb; 485 struct exfat_chain dir; 486 unsigned int start_clu = 487 le32_to_cpu(ep->dentry.generic_secondary.start_clu); 488 u64 size = le64_to_cpu(ep->dentry.generic_secondary.size); 489 unsigned char flags = ep->dentry.generic_secondary.flags; 490 491 if (!(flags & ALLOC_POSSIBLE) || !start_clu || !size) 492 return; 493 494 exfat_chain_set(&dir, start_clu, 495 EXFAT_B_TO_CLU_ROUND_UP(size, EXFAT_SB(sb)), 496 flags); 497 exfat_free_cluster(inode, &dir); 498 } 499 500 void exfat_init_ext_entry(struct exfat_entry_set_cache *es, int num_entries, 501 struct exfat_uni_name *p_uniname) 502 { 503 int i; 504 unsigned short *uniname = p_uniname->name; 505 struct exfat_dentry *ep; 506 507 ep = exfat_get_dentry_cached(es, ES_IDX_FILE); 508 ep->dentry.file.num_ext = (unsigned char)(num_entries - 1); 509 510 ep = exfat_get_dentry_cached(es, ES_IDX_STREAM); 511 ep->dentry.stream.name_len = p_uniname->name_len; 512 ep->dentry.stream.name_hash = cpu_to_le16(p_uniname->name_hash); 513 514 for (i = ES_IDX_FIRST_FILENAME; i < num_entries; i++) { 515 ep = exfat_get_dentry_cached(es, i); 516 exfat_init_name_entry(ep, uniname); 517 uniname += EXFAT_FILE_NAME_LEN; 518 } 519 520 exfat_update_dir_chksum(es); 521 } 522 523 void exfat_remove_entries(struct inode *inode, struct exfat_entry_set_cache *es, 524 int order) 525 { 526 int i; 527 struct exfat_dentry *ep; 528 529 for (i = order; i < es->num_entries; i++) { 530 ep = exfat_get_dentry_cached(es, i); 531 532 if (exfat_get_entry_type(ep) & TYPE_BENIGN_SEC) 533 exfat_free_benign_secondary_clusters(inode, ep); 534 535 exfat_set_entry_type(ep, TYPE_DELETED); 536 } 537 538 if (order < es->num_entries) 539 es->modified = true; 540 } 541 542 void exfat_update_dir_chksum(struct exfat_entry_set_cache *es) 543 { 544 int chksum_type = CS_DIR_ENTRY, i; 545 unsigned short chksum = 0; 546 struct exfat_dentry *ep; 547 548 for (i = ES_IDX_FILE; i < es->num_entries; i++) { 549 ep = exfat_get_dentry_cached(es, i); 550 chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum, 551 chksum_type); 552 chksum_type = CS_DEFAULT; 553 } 554 ep = exfat_get_dentry_cached(es, ES_IDX_FILE); 555 ep->dentry.file.checksum = cpu_to_le16(chksum); 556 es->modified = true; 557 } 558 559 int exfat_put_dentry_set(struct exfat_entry_set_cache *es, int sync) 560 { 561 int i, err = 0; 562 563 if (es->modified) 564 err = exfat_update_bhs(es->bh, es->num_bh, sync); 565 566 for (i = 0; i < es->num_bh; i++) 567 if (err) 568 bforget(es->bh[i]); 569 else 570 brelse(es->bh[i]); 571 572 if (IS_DYNAMIC_ES(es)) 573 kfree(es->bh); 574 575 return err; 576 } 577 578 static int exfat_walk_fat_chain(struct super_block *sb, 579 struct exfat_chain *p_dir, unsigned int byte_offset, 580 unsigned int *clu) 581 { 582 struct exfat_sb_info *sbi = EXFAT_SB(sb); 583 unsigned int clu_offset; 584 unsigned int cur_clu; 585 586 clu_offset = EXFAT_B_TO_CLU(byte_offset, sbi); 587 cur_clu = p_dir->dir; 588 589 if (p_dir->flags == ALLOC_NO_FAT_CHAIN) { 590 cur_clu += clu_offset; 591 } else { 592 while (clu_offset > 0) { 593 if (exfat_get_next_cluster(sb, &cur_clu)) 594 return -EIO; 595 if (cur_clu == EXFAT_EOF_CLUSTER) { 596 exfat_fs_error(sb, 597 "invalid dentry access beyond EOF (clu : %u, eidx : %d)", 598 p_dir->dir, 599 EXFAT_B_TO_DEN(byte_offset)); 600 return -EIO; 601 } 602 clu_offset--; 603 } 604 } 605 606 *clu = cur_clu; 607 return 0; 608 } 609 610 static int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir, 611 int entry, sector_t *sector, int *offset) 612 { 613 int ret; 614 unsigned int off, clu = 0; 615 struct exfat_sb_info *sbi = EXFAT_SB(sb); 616 617 off = EXFAT_DEN_TO_B(entry); 618 619 ret = exfat_walk_fat_chain(sb, p_dir, off, &clu); 620 if (ret) 621 return ret; 622 623 /* byte offset in cluster */ 624 off = EXFAT_CLU_OFFSET(off, sbi); 625 626 /* byte offset in sector */ 627 *offset = EXFAT_BLK_OFFSET(off, sb); 628 629 /* sector offset in cluster */ 630 *sector = EXFAT_B_TO_BLK(off, sb); 631 *sector += exfat_cluster_to_sector(sbi, clu); 632 return 0; 633 } 634 635 #define EXFAT_MAX_RA_SIZE (128*1024) 636 static int exfat_dir_readahead(struct super_block *sb, sector_t sec) 637 { 638 struct exfat_sb_info *sbi = EXFAT_SB(sb); 639 struct buffer_head *bh; 640 unsigned int max_ra_count = EXFAT_MAX_RA_SIZE >> sb->s_blocksize_bits; 641 unsigned int page_ra_count = PAGE_SIZE >> sb->s_blocksize_bits; 642 unsigned int adj_ra_count = max(sbi->sect_per_clus, page_ra_count); 643 unsigned int ra_count = min(adj_ra_count, max_ra_count); 644 645 /* Read-ahead is not required */ 646 if (sbi->sect_per_clus == 1) 647 return 0; 648 649 if (sec < sbi->data_start_sector) { 650 exfat_err(sb, "requested sector is invalid(sect:%llu, root:%llu)", 651 (unsigned long long)sec, sbi->data_start_sector); 652 return -EIO; 653 } 654 655 /* Not sector aligned with ra_count, resize ra_count to page size */ 656 if ((sec - sbi->data_start_sector) & (ra_count - 1)) 657 ra_count = page_ra_count; 658 659 bh = sb_find_get_block(sb, sec); 660 if (!bh || !buffer_uptodate(bh)) { 661 unsigned int i; 662 663 for (i = 0; i < ra_count; i++) 664 sb_breadahead(sb, (sector_t)(sec + i)); 665 } 666 brelse(bh); 667 return 0; 668 } 669 670 struct exfat_dentry *exfat_get_dentry(struct super_block *sb, 671 struct exfat_chain *p_dir, int entry, struct buffer_head **bh) 672 { 673 unsigned int dentries_per_page = EXFAT_B_TO_DEN(PAGE_SIZE); 674 int off; 675 sector_t sec; 676 677 if (p_dir->dir == DIR_DELETED) { 678 exfat_err(sb, "abnormal access to deleted dentry"); 679 return NULL; 680 } 681 682 if (exfat_find_location(sb, p_dir, entry, &sec, &off)) 683 return NULL; 684 685 if (p_dir->dir != EXFAT_FREE_CLUSTER && 686 !(entry & (dentries_per_page - 1))) 687 exfat_dir_readahead(sb, sec); 688 689 *bh = sb_bread(sb, sec); 690 if (!*bh) 691 return NULL; 692 693 return (struct exfat_dentry *)((*bh)->b_data + off); 694 } 695 696 enum exfat_validate_dentry_mode { 697 ES_MODE_GET_FILE_ENTRY, 698 ES_MODE_GET_STRM_ENTRY, 699 ES_MODE_GET_NAME_ENTRY, 700 ES_MODE_GET_CRITICAL_SEC_ENTRY, 701 ES_MODE_GET_BENIGN_SEC_ENTRY, 702 }; 703 704 static bool exfat_validate_entry(unsigned int type, 705 enum exfat_validate_dentry_mode *mode) 706 { 707 if (type == TYPE_UNUSED || type == TYPE_DELETED) 708 return false; 709 710 switch (*mode) { 711 case ES_MODE_GET_FILE_ENTRY: 712 if (type != TYPE_STREAM) 713 return false; 714 *mode = ES_MODE_GET_STRM_ENTRY; 715 break; 716 case ES_MODE_GET_STRM_ENTRY: 717 if (type != TYPE_EXTEND) 718 return false; 719 *mode = ES_MODE_GET_NAME_ENTRY; 720 break; 721 case ES_MODE_GET_NAME_ENTRY: 722 if (type & TYPE_BENIGN_SEC) 723 *mode = ES_MODE_GET_BENIGN_SEC_ENTRY; 724 else if (type != TYPE_EXTEND) 725 return false; 726 break; 727 case ES_MODE_GET_BENIGN_SEC_ENTRY: 728 /* Assume unreconized benign secondary entry */ 729 if (!(type & TYPE_BENIGN_SEC)) 730 return false; 731 break; 732 default: 733 return false; 734 } 735 736 return true; 737 } 738 739 struct exfat_dentry *exfat_get_dentry_cached( 740 struct exfat_entry_set_cache *es, int num) 741 { 742 int off = es->start_off + num * DENTRY_SIZE; 743 struct buffer_head *bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)]; 744 char *p = bh->b_data + EXFAT_BLK_OFFSET(off, es->sb); 745 746 return (struct exfat_dentry *)p; 747 } 748 749 /* 750 * Returns a set of dentries. 751 * 752 * Note It provides a direct pointer to bh->data via exfat_get_dentry_cached(). 753 * User should call exfat_get_dentry_set() after setting 'modified' to apply 754 * changes made in this entry set to the real device. 755 * 756 * in: 757 * sb+p_dir+entry: indicates a file/dir 758 * num_entries: specifies how many dentries should be included. 759 * It will be set to es->num_entries if it is not 0. 760 * If num_entries is 0, es->num_entries will be obtained 761 * from the first dentry. 762 * out: 763 * es: pointer of entry set on success. 764 * return: 765 * 0 on success 766 * -error code on failure 767 */ 768 static int __exfat_get_dentry_set(struct exfat_entry_set_cache *es, 769 struct super_block *sb, struct exfat_chain *p_dir, int entry, 770 unsigned int num_entries) 771 { 772 int ret, i, num_bh; 773 unsigned int off; 774 sector_t sec; 775 struct exfat_sb_info *sbi = EXFAT_SB(sb); 776 struct buffer_head *bh; 777 778 if (p_dir->dir == DIR_DELETED) { 779 exfat_err(sb, "access to deleted dentry"); 780 return -EIO; 781 } 782 783 ret = exfat_find_location(sb, p_dir, entry, &sec, &off); 784 if (ret) 785 return ret; 786 787 memset(es, 0, sizeof(*es)); 788 es->sb = sb; 789 es->modified = false; 790 es->start_off = off; 791 es->bh = es->__bh; 792 793 bh = sb_bread(sb, sec); 794 if (!bh) 795 return -EIO; 796 es->bh[es->num_bh++] = bh; 797 798 if (num_entries == ES_ALL_ENTRIES) { 799 struct exfat_dentry *ep; 800 801 ep = exfat_get_dentry_cached(es, ES_IDX_FILE); 802 if (ep->type != EXFAT_FILE) { 803 brelse(bh); 804 return -EIO; 805 } 806 807 num_entries = ep->dentry.file.num_ext + 1; 808 } 809 810 es->num_entries = num_entries; 811 812 num_bh = EXFAT_B_TO_BLK_ROUND_UP(off + num_entries * DENTRY_SIZE, sb); 813 if (num_bh > ARRAY_SIZE(es->__bh)) { 814 es->bh = kmalloc_array(num_bh, sizeof(*es->bh), GFP_KERNEL); 815 if (!es->bh) { 816 brelse(bh); 817 return -ENOMEM; 818 } 819 es->bh[0] = bh; 820 } 821 822 for (i = 1; i < num_bh; i++) { 823 /* get the next sector */ 824 if (exfat_is_last_sector_in_cluster(sbi, sec)) { 825 unsigned int clu = exfat_sector_to_cluster(sbi, sec); 826 827 if (p_dir->flags == ALLOC_NO_FAT_CHAIN) 828 clu++; 829 else if (exfat_get_next_cluster(sb, &clu)) 830 goto put_es; 831 sec = exfat_cluster_to_sector(sbi, clu); 832 } else { 833 sec++; 834 } 835 836 bh = sb_bread(sb, sec); 837 if (!bh) 838 goto put_es; 839 es->bh[es->num_bh++] = bh; 840 } 841 842 return 0; 843 844 put_es: 845 exfat_put_dentry_set(es, false); 846 return -EIO; 847 } 848 849 int exfat_get_dentry_set(struct exfat_entry_set_cache *es, 850 struct super_block *sb, struct exfat_chain *p_dir, 851 int entry, unsigned int num_entries) 852 { 853 int ret, i; 854 struct exfat_dentry *ep; 855 enum exfat_validate_dentry_mode mode = ES_MODE_GET_FILE_ENTRY; 856 857 ret = __exfat_get_dentry_set(es, sb, p_dir, entry, num_entries); 858 if (ret < 0) 859 return ret; 860 861 /* validate cached dentries */ 862 for (i = ES_IDX_STREAM; i < es->num_entries; i++) { 863 ep = exfat_get_dentry_cached(es, i); 864 if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode)) 865 goto put_es; 866 } 867 return 0; 868 869 put_es: 870 exfat_put_dentry_set(es, false); 871 return -EIO; 872 } 873 874 static int exfat_validate_empty_dentry_set(struct exfat_entry_set_cache *es) 875 { 876 struct exfat_dentry *ep; 877 struct buffer_head *bh; 878 int i, off; 879 bool unused_hit = false; 880 881 /* 882 * ONLY UNUSED OR DELETED DENTRIES ARE ALLOWED: 883 * Although it violates the specification for a deleted entry to 884 * follow an unused entry, some exFAT implementations could work 885 * like this. Therefore, to improve compatibility, let's allow it. 886 */ 887 for (i = 0; i < es->num_entries; i++) { 888 ep = exfat_get_dentry_cached(es, i); 889 if (ep->type == EXFAT_UNUSED) { 890 unused_hit = true; 891 } else if (!IS_EXFAT_DELETED(ep->type)) { 892 if (unused_hit) 893 goto err_used_follow_unused; 894 i++; 895 goto count_skip_entries; 896 } 897 } 898 899 return 0; 900 901 err_used_follow_unused: 902 off = es->start_off + (i << DENTRY_SIZE_BITS); 903 bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)]; 904 905 exfat_fs_error(es->sb, 906 "in sector %lld, dentry %d should be unused, but 0x%x", 907 bh->b_blocknr, off >> DENTRY_SIZE_BITS, ep->type); 908 909 return -EIO; 910 911 count_skip_entries: 912 es->num_entries = EXFAT_B_TO_DEN(EXFAT_BLK_TO_B(es->num_bh, es->sb) - es->start_off); 913 for (; i < es->num_entries; i++) { 914 ep = exfat_get_dentry_cached(es, i); 915 if (IS_EXFAT_DELETED(ep->type)) 916 break; 917 } 918 919 return i; 920 } 921 922 /* 923 * Get an empty dentry set. 924 * 925 * in: 926 * sb+p_dir+entry: indicates the empty dentry location 927 * num_entries: specifies how many empty dentries should be included. 928 * out: 929 * es: pointer of empty dentry set on success. 930 * return: 931 * 0 : on success 932 * >0 : the dentries are not empty, the return value is the number of 933 * dentries to be skipped for the next lookup. 934 * <0 : on failure 935 */ 936 int exfat_get_empty_dentry_set(struct exfat_entry_set_cache *es, 937 struct super_block *sb, struct exfat_chain *p_dir, 938 int entry, unsigned int num_entries) 939 { 940 int ret; 941 942 ret = __exfat_get_dentry_set(es, sb, p_dir, entry, num_entries); 943 if (ret < 0) 944 return ret; 945 946 ret = exfat_validate_empty_dentry_set(es); 947 if (ret) 948 exfat_put_dentry_set(es, false); 949 950 return ret; 951 } 952 953 static inline void exfat_reset_empty_hint(struct exfat_hint_femp *hint_femp) 954 { 955 hint_femp->eidx = EXFAT_HINT_NONE; 956 hint_femp->count = 0; 957 } 958 959 static inline void exfat_set_empty_hint(struct exfat_inode_info *ei, 960 struct exfat_hint_femp *candi_empty, struct exfat_chain *clu, 961 int dentry, int num_entries, int entry_type) 962 { 963 if (ei->hint_femp.eidx == EXFAT_HINT_NONE || 964 ei->hint_femp.eidx > dentry) { 965 int total_entries = EXFAT_B_TO_DEN(i_size_read(&ei->vfs_inode)); 966 967 if (candi_empty->count == 0) { 968 candi_empty->cur = *clu; 969 candi_empty->eidx = dentry; 970 } 971 972 if (entry_type == TYPE_UNUSED) 973 candi_empty->count += total_entries - dentry; 974 else 975 candi_empty->count++; 976 977 if (candi_empty->count == num_entries || 978 candi_empty->count + candi_empty->eidx == total_entries) 979 ei->hint_femp = *candi_empty; 980 } 981 } 982 983 enum { 984 DIRENT_STEP_FILE, 985 DIRENT_STEP_STRM, 986 DIRENT_STEP_NAME, 987 DIRENT_STEP_SECD, 988 }; 989 990 /* 991 * @ei: inode info of parent directory 992 * @p_dir: directory structure of parent directory 993 * @num_entries:entry size of p_uniname 994 * @hint_opt: If p_uniname is found, filled with optimized dir/entry 995 * for traversing cluster chain. 996 * @return: 997 * >= 0: file directory entry position where the name exists 998 * -ENOENT: entry with the name does not exist 999 * -EIO: I/O error 1000 */ 1001 int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei, 1002 struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname, 1003 struct exfat_hint *hint_opt) 1004 { 1005 int i, rewind = 0, dentry = 0, end_eidx = 0, num_ext = 0, len; 1006 int order, step, name_len = 0; 1007 int dentries_per_clu; 1008 unsigned int entry_type; 1009 unsigned short *uniname = NULL; 1010 struct exfat_chain clu; 1011 struct exfat_hint *hint_stat = &ei->hint_stat; 1012 struct exfat_hint_femp candi_empty; 1013 struct exfat_sb_info *sbi = EXFAT_SB(sb); 1014 int num_entries = exfat_calc_num_entries(p_uniname); 1015 1016 if (num_entries < 0) 1017 return num_entries; 1018 1019 dentries_per_clu = sbi->dentries_per_clu; 1020 1021 exfat_chain_dup(&clu, p_dir); 1022 1023 if (hint_stat->eidx) { 1024 clu.dir = hint_stat->clu; 1025 dentry = hint_stat->eidx; 1026 end_eidx = dentry; 1027 } 1028 1029 exfat_reset_empty_hint(&ei->hint_femp); 1030 1031 rewind: 1032 order = 0; 1033 step = DIRENT_STEP_FILE; 1034 exfat_reset_empty_hint(&candi_empty); 1035 1036 while (clu.dir != EXFAT_EOF_CLUSTER) { 1037 i = dentry & (dentries_per_clu - 1); 1038 for (; i < dentries_per_clu; i++, dentry++) { 1039 struct exfat_dentry *ep; 1040 struct buffer_head *bh; 1041 1042 if (rewind && dentry == end_eidx) 1043 goto not_found; 1044 1045 ep = exfat_get_dentry(sb, &clu, i, &bh); 1046 if (!ep) 1047 return -EIO; 1048 1049 entry_type = exfat_get_entry_type(ep); 1050 1051 if (entry_type == TYPE_UNUSED || 1052 entry_type == TYPE_DELETED) { 1053 step = DIRENT_STEP_FILE; 1054 1055 exfat_set_empty_hint(ei, &candi_empty, &clu, 1056 dentry, num_entries, 1057 entry_type); 1058 1059 brelse(bh); 1060 if (entry_type == TYPE_UNUSED) 1061 goto not_found; 1062 continue; 1063 } 1064 1065 exfat_reset_empty_hint(&candi_empty); 1066 1067 if (entry_type == TYPE_FILE || entry_type == TYPE_DIR) { 1068 step = DIRENT_STEP_FILE; 1069 hint_opt->clu = clu.dir; 1070 hint_opt->eidx = i; 1071 num_ext = ep->dentry.file.num_ext; 1072 step = DIRENT_STEP_STRM; 1073 brelse(bh); 1074 continue; 1075 } 1076 1077 if (entry_type == TYPE_STREAM) { 1078 u16 name_hash; 1079 1080 if (step != DIRENT_STEP_STRM) { 1081 step = DIRENT_STEP_FILE; 1082 brelse(bh); 1083 continue; 1084 } 1085 step = DIRENT_STEP_FILE; 1086 name_hash = le16_to_cpu( 1087 ep->dentry.stream.name_hash); 1088 if (p_uniname->name_hash == name_hash && 1089 p_uniname->name_len == 1090 ep->dentry.stream.name_len) { 1091 step = DIRENT_STEP_NAME; 1092 order = 1; 1093 name_len = 0; 1094 } 1095 brelse(bh); 1096 continue; 1097 } 1098 1099 brelse(bh); 1100 if (entry_type == TYPE_EXTEND) { 1101 unsigned short entry_uniname[16], unichar; 1102 1103 if (step != DIRENT_STEP_NAME || 1104 name_len >= MAX_NAME_LENGTH) { 1105 step = DIRENT_STEP_FILE; 1106 continue; 1107 } 1108 1109 if (++order == 2) 1110 uniname = p_uniname->name; 1111 else 1112 uniname += EXFAT_FILE_NAME_LEN; 1113 1114 len = exfat_extract_uni_name(ep, entry_uniname); 1115 name_len += len; 1116 1117 unichar = *(uniname+len); 1118 *(uniname+len) = 0x0; 1119 1120 if (exfat_uniname_ncmp(sb, uniname, 1121 entry_uniname, len)) { 1122 step = DIRENT_STEP_FILE; 1123 } else if (p_uniname->name_len == name_len) { 1124 if (order == num_ext) 1125 goto found; 1126 step = DIRENT_STEP_SECD; 1127 } 1128 1129 *(uniname+len) = unichar; 1130 continue; 1131 } 1132 1133 if (entry_type & 1134 (TYPE_CRITICAL_SEC | TYPE_BENIGN_SEC)) { 1135 if (step == DIRENT_STEP_SECD) { 1136 if (++order == num_ext) 1137 goto found; 1138 continue; 1139 } 1140 } 1141 step = DIRENT_STEP_FILE; 1142 } 1143 1144 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1145 if (--clu.size > 0) 1146 clu.dir++; 1147 else 1148 clu.dir = EXFAT_EOF_CLUSTER; 1149 } else { 1150 if (exfat_get_next_cluster(sb, &clu.dir)) 1151 return -EIO; 1152 } 1153 } 1154 1155 not_found: 1156 /* 1157 * We started at not 0 index,so we should try to find target 1158 * from 0 index to the index we started at. 1159 */ 1160 if (!rewind && end_eidx) { 1161 rewind = 1; 1162 dentry = 0; 1163 clu.dir = p_dir->dir; 1164 goto rewind; 1165 } 1166 1167 /* 1168 * set the EXFAT_EOF_CLUSTER flag to avoid search 1169 * from the beginning again when allocated a new cluster 1170 */ 1171 if (ei->hint_femp.eidx == EXFAT_HINT_NONE) { 1172 ei->hint_femp.cur.dir = EXFAT_EOF_CLUSTER; 1173 ei->hint_femp.eidx = p_dir->size * dentries_per_clu; 1174 ei->hint_femp.count = 0; 1175 } 1176 1177 /* initialized hint_stat */ 1178 hint_stat->clu = p_dir->dir; 1179 hint_stat->eidx = 0; 1180 return -ENOENT; 1181 1182 found: 1183 /* next dentry we'll find is out of this cluster */ 1184 if (!((dentry + 1) & (dentries_per_clu - 1))) { 1185 int ret = 0; 1186 1187 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1188 if (--clu.size > 0) 1189 clu.dir++; 1190 else 1191 clu.dir = EXFAT_EOF_CLUSTER; 1192 } else { 1193 ret = exfat_get_next_cluster(sb, &clu.dir); 1194 } 1195 1196 if (ret || clu.dir == EXFAT_EOF_CLUSTER) { 1197 /* just initialized hint_stat */ 1198 hint_stat->clu = p_dir->dir; 1199 hint_stat->eidx = 0; 1200 return (dentry - num_ext); 1201 } 1202 } 1203 1204 hint_stat->clu = clu.dir; 1205 hint_stat->eidx = dentry + 1; 1206 return dentry - num_ext; 1207 } 1208 1209 int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir) 1210 { 1211 int i, count = 0; 1212 int dentries_per_clu; 1213 unsigned int entry_type; 1214 struct exfat_chain clu; 1215 struct exfat_dentry *ep; 1216 struct exfat_sb_info *sbi = EXFAT_SB(sb); 1217 struct buffer_head *bh; 1218 1219 dentries_per_clu = sbi->dentries_per_clu; 1220 1221 exfat_chain_dup(&clu, p_dir); 1222 1223 while (clu.dir != EXFAT_EOF_CLUSTER) { 1224 for (i = 0; i < dentries_per_clu; i++) { 1225 ep = exfat_get_dentry(sb, &clu, i, &bh); 1226 if (!ep) 1227 return -EIO; 1228 entry_type = exfat_get_entry_type(ep); 1229 brelse(bh); 1230 1231 if (entry_type == TYPE_UNUSED) 1232 return count; 1233 if (entry_type != TYPE_DIR) 1234 continue; 1235 count++; 1236 } 1237 1238 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1239 if (--clu.size > 0) 1240 clu.dir++; 1241 else 1242 clu.dir = EXFAT_EOF_CLUSTER; 1243 } else { 1244 if (exfat_get_next_cluster(sb, &(clu.dir))) 1245 return -EIO; 1246 } 1247 } 1248 1249 return count; 1250 } 1251