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 memset(ep, 0, sizeof(*ep)); 424 exfat_set_entry_type(ep, TYPE_STREAM); 425 if (size == 0) 426 ep->dentry.stream.flags = ALLOC_FAT_CHAIN; 427 else 428 ep->dentry.stream.flags = ALLOC_NO_FAT_CHAIN; 429 ep->dentry.stream.start_clu = cpu_to_le32(start_clu); 430 ep->dentry.stream.valid_size = cpu_to_le64(size); 431 ep->dentry.stream.size = cpu_to_le64(size); 432 } 433 434 static void exfat_init_name_entry(struct exfat_dentry *ep, 435 unsigned short *uniname) 436 { 437 int i; 438 439 exfat_set_entry_type(ep, TYPE_EXTEND); 440 ep->dentry.name.flags = 0x0; 441 442 for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) { 443 if (*uniname != 0x0) { 444 ep->dentry.name.unicode_0_14[i] = cpu_to_le16(*uniname); 445 uniname++; 446 } else { 447 ep->dentry.name.unicode_0_14[i] = 0x0; 448 } 449 } 450 } 451 452 void exfat_init_dir_entry(struct exfat_entry_set_cache *es, 453 unsigned int type, unsigned int start_clu, 454 unsigned long long size, struct timespec64 *ts) 455 { 456 struct super_block *sb = es->sb; 457 struct exfat_sb_info *sbi = EXFAT_SB(sb); 458 struct exfat_dentry *ep; 459 460 ep = exfat_get_dentry_cached(es, ES_IDX_FILE); 461 memset(ep, 0, sizeof(*ep)); 462 exfat_set_entry_type(ep, type); 463 exfat_set_entry_time(sbi, ts, 464 &ep->dentry.file.create_tz, 465 &ep->dentry.file.create_time, 466 &ep->dentry.file.create_date, 467 &ep->dentry.file.create_time_cs); 468 exfat_set_entry_time(sbi, ts, 469 &ep->dentry.file.modify_tz, 470 &ep->dentry.file.modify_time, 471 &ep->dentry.file.modify_date, 472 &ep->dentry.file.modify_time_cs); 473 exfat_set_entry_time(sbi, ts, 474 &ep->dentry.file.access_tz, 475 &ep->dentry.file.access_time, 476 &ep->dentry.file.access_date, 477 NULL); 478 479 ep = exfat_get_dentry_cached(es, ES_IDX_STREAM); 480 exfat_init_stream_entry(ep, start_clu, size); 481 } 482 483 static void exfat_free_benign_secondary_clusters(struct inode *inode, 484 struct exfat_dentry *ep) 485 { 486 struct super_block *sb = inode->i_sb; 487 struct exfat_chain dir; 488 unsigned int start_clu = 489 le32_to_cpu(ep->dentry.generic_secondary.start_clu); 490 u64 size = le64_to_cpu(ep->dentry.generic_secondary.size); 491 unsigned char flags = ep->dentry.generic_secondary.flags; 492 493 if (!(flags & ALLOC_POSSIBLE) || !start_clu || !size) 494 return; 495 496 exfat_chain_set(&dir, start_clu, 497 EXFAT_B_TO_CLU_ROUND_UP(size, EXFAT_SB(sb)), 498 flags); 499 exfat_free_cluster(inode, &dir); 500 } 501 502 void exfat_init_ext_entry(struct exfat_entry_set_cache *es, int num_entries, 503 struct exfat_uni_name *p_uniname) 504 { 505 int i; 506 unsigned short *uniname = p_uniname->name; 507 struct exfat_dentry *ep; 508 509 ep = exfat_get_dentry_cached(es, ES_IDX_FILE); 510 ep->dentry.file.num_ext = (unsigned char)(num_entries - 1); 511 512 ep = exfat_get_dentry_cached(es, ES_IDX_STREAM); 513 ep->dentry.stream.name_len = p_uniname->name_len; 514 ep->dentry.stream.name_hash = cpu_to_le16(p_uniname->name_hash); 515 516 for (i = ES_IDX_FIRST_FILENAME; i < num_entries; i++) { 517 ep = exfat_get_dentry_cached(es, i); 518 exfat_init_name_entry(ep, uniname); 519 uniname += EXFAT_FILE_NAME_LEN; 520 } 521 522 exfat_update_dir_chksum(es); 523 } 524 525 void exfat_remove_entries(struct inode *inode, struct exfat_entry_set_cache *es, 526 int order) 527 { 528 int i; 529 struct exfat_dentry *ep; 530 531 for (i = order; i < es->num_entries; i++) { 532 ep = exfat_get_dentry_cached(es, i); 533 534 if (exfat_get_entry_type(ep) & TYPE_BENIGN_SEC) 535 exfat_free_benign_secondary_clusters(inode, ep); 536 537 exfat_set_entry_type(ep, TYPE_DELETED); 538 } 539 540 if (order < es->num_entries) 541 es->modified = true; 542 } 543 544 void exfat_update_dir_chksum(struct exfat_entry_set_cache *es) 545 { 546 int chksum_type = CS_DIR_ENTRY, i; 547 unsigned short chksum = 0; 548 struct exfat_dentry *ep; 549 550 for (i = ES_IDX_FILE; i < es->num_entries; i++) { 551 ep = exfat_get_dentry_cached(es, i); 552 chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum, 553 chksum_type); 554 chksum_type = CS_DEFAULT; 555 } 556 ep = exfat_get_dentry_cached(es, ES_IDX_FILE); 557 ep->dentry.file.checksum = cpu_to_le16(chksum); 558 es->modified = true; 559 } 560 561 int exfat_put_dentry_set(struct exfat_entry_set_cache *es, int sync) 562 { 563 int i, err = 0; 564 565 if (es->modified) 566 err = exfat_update_bhs(es->bh, es->num_bh, sync); 567 568 for (i = 0; i < es->num_bh; i++) 569 if (err) 570 bforget(es->bh[i]); 571 else 572 brelse(es->bh[i]); 573 574 if (IS_DYNAMIC_ES(es)) 575 kfree(es->bh); 576 577 return err; 578 } 579 580 static int exfat_walk_fat_chain(struct super_block *sb, 581 struct exfat_chain *p_dir, unsigned int byte_offset, 582 unsigned int *clu) 583 { 584 struct exfat_sb_info *sbi = EXFAT_SB(sb); 585 unsigned int clu_offset; 586 unsigned int cur_clu; 587 588 clu_offset = EXFAT_B_TO_CLU(byte_offset, sbi); 589 cur_clu = p_dir->dir; 590 591 if (p_dir->flags == ALLOC_NO_FAT_CHAIN) { 592 cur_clu += clu_offset; 593 } else { 594 while (clu_offset > 0) { 595 if (exfat_get_next_cluster(sb, &cur_clu)) 596 return -EIO; 597 if (cur_clu == EXFAT_EOF_CLUSTER) { 598 exfat_fs_error(sb, 599 "invalid dentry access beyond EOF (clu : %u, eidx : %d)", 600 p_dir->dir, 601 EXFAT_B_TO_DEN(byte_offset)); 602 return -EIO; 603 } 604 clu_offset--; 605 } 606 } 607 608 *clu = cur_clu; 609 return 0; 610 } 611 612 static int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir, 613 int entry, sector_t *sector, int *offset) 614 { 615 int ret; 616 unsigned int off, clu = 0; 617 struct exfat_sb_info *sbi = EXFAT_SB(sb); 618 619 off = EXFAT_DEN_TO_B(entry); 620 621 ret = exfat_walk_fat_chain(sb, p_dir, off, &clu); 622 if (ret) 623 return ret; 624 625 /* byte offset in cluster */ 626 off = EXFAT_CLU_OFFSET(off, sbi); 627 628 /* byte offset in sector */ 629 *offset = EXFAT_BLK_OFFSET(off, sb); 630 631 /* sector offset in cluster */ 632 *sector = EXFAT_B_TO_BLK(off, sb); 633 *sector += exfat_cluster_to_sector(sbi, clu); 634 return 0; 635 } 636 637 #define EXFAT_MAX_RA_SIZE (128*1024) 638 static int exfat_dir_readahead(struct super_block *sb, sector_t sec) 639 { 640 struct exfat_sb_info *sbi = EXFAT_SB(sb); 641 struct buffer_head *bh; 642 unsigned int max_ra_count = EXFAT_MAX_RA_SIZE >> sb->s_blocksize_bits; 643 unsigned int page_ra_count = PAGE_SIZE >> sb->s_blocksize_bits; 644 unsigned int adj_ra_count = max(sbi->sect_per_clus, page_ra_count); 645 unsigned int ra_count = min(adj_ra_count, max_ra_count); 646 647 /* Read-ahead is not required */ 648 if (sbi->sect_per_clus == 1) 649 return 0; 650 651 if (sec < sbi->data_start_sector) { 652 exfat_err(sb, "requested sector is invalid(sect:%llu, root:%llu)", 653 (unsigned long long)sec, sbi->data_start_sector); 654 return -EIO; 655 } 656 657 /* Not sector aligned with ra_count, resize ra_count to page size */ 658 if ((sec - sbi->data_start_sector) & (ra_count - 1)) 659 ra_count = page_ra_count; 660 661 bh = sb_find_get_block(sb, sec); 662 if (!bh || !buffer_uptodate(bh)) { 663 unsigned int i; 664 665 for (i = 0; i < ra_count; i++) 666 sb_breadahead(sb, (sector_t)(sec + i)); 667 } 668 brelse(bh); 669 return 0; 670 } 671 672 struct exfat_dentry *exfat_get_dentry(struct super_block *sb, 673 struct exfat_chain *p_dir, int entry, struct buffer_head **bh) 674 { 675 unsigned int dentries_per_page = EXFAT_B_TO_DEN(PAGE_SIZE); 676 int off; 677 sector_t sec; 678 679 if (p_dir->dir == DIR_DELETED) { 680 exfat_err(sb, "abnormal access to deleted dentry"); 681 return NULL; 682 } 683 684 if (exfat_find_location(sb, p_dir, entry, &sec, &off)) 685 return NULL; 686 687 if (p_dir->dir != EXFAT_FREE_CLUSTER && 688 !(entry & (dentries_per_page - 1))) 689 exfat_dir_readahead(sb, sec); 690 691 *bh = sb_bread(sb, sec); 692 if (!*bh) 693 return NULL; 694 695 return (struct exfat_dentry *)((*bh)->b_data + off); 696 } 697 698 enum exfat_validate_dentry_mode { 699 ES_MODE_GET_FILE_ENTRY, 700 ES_MODE_GET_STRM_ENTRY, 701 ES_MODE_GET_NAME_ENTRY, 702 ES_MODE_GET_CRITICAL_SEC_ENTRY, 703 ES_MODE_GET_BENIGN_SEC_ENTRY, 704 }; 705 706 static bool exfat_validate_entry(unsigned int type, 707 enum exfat_validate_dentry_mode *mode) 708 { 709 if (type == TYPE_UNUSED || type == TYPE_DELETED) 710 return false; 711 712 switch (*mode) { 713 case ES_MODE_GET_FILE_ENTRY: 714 if (type != TYPE_STREAM) 715 return false; 716 *mode = ES_MODE_GET_STRM_ENTRY; 717 break; 718 case ES_MODE_GET_STRM_ENTRY: 719 if (type != TYPE_EXTEND) 720 return false; 721 *mode = ES_MODE_GET_NAME_ENTRY; 722 break; 723 case ES_MODE_GET_NAME_ENTRY: 724 if (type & TYPE_BENIGN_SEC) 725 *mode = ES_MODE_GET_BENIGN_SEC_ENTRY; 726 else if (type != TYPE_EXTEND) 727 return false; 728 break; 729 case ES_MODE_GET_BENIGN_SEC_ENTRY: 730 /* Assume unreconized benign secondary entry */ 731 if (!(type & TYPE_BENIGN_SEC)) 732 return false; 733 break; 734 default: 735 return false; 736 } 737 738 return true; 739 } 740 741 struct exfat_dentry *exfat_get_dentry_cached( 742 struct exfat_entry_set_cache *es, int num) 743 { 744 int off = es->start_off + num * DENTRY_SIZE; 745 struct buffer_head *bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)]; 746 char *p = bh->b_data + EXFAT_BLK_OFFSET(off, es->sb); 747 748 return (struct exfat_dentry *)p; 749 } 750 751 /* 752 * Returns a set of dentries. 753 * 754 * Note It provides a direct pointer to bh->data via exfat_get_dentry_cached(). 755 * User should call exfat_get_dentry_set() after setting 'modified' to apply 756 * changes made in this entry set to the real device. 757 * 758 * in: 759 * sb+p_dir+entry: indicates a file/dir 760 * num_entries: specifies how many dentries should be included. 761 * It will be set to es->num_entries if it is not 0. 762 * If num_entries is 0, es->num_entries will be obtained 763 * from the first dentry. 764 * out: 765 * es: pointer of entry set on success. 766 * return: 767 * 0 on success 768 * -error code on failure 769 */ 770 static int __exfat_get_dentry_set(struct exfat_entry_set_cache *es, 771 struct super_block *sb, struct exfat_chain *p_dir, int entry, 772 unsigned int num_entries) 773 { 774 int ret, i, num_bh; 775 unsigned int off; 776 sector_t sec; 777 struct exfat_sb_info *sbi = EXFAT_SB(sb); 778 struct buffer_head *bh; 779 780 if (p_dir->dir == DIR_DELETED) { 781 exfat_err(sb, "access to deleted dentry"); 782 return -EIO; 783 } 784 785 ret = exfat_find_location(sb, p_dir, entry, &sec, &off); 786 if (ret) 787 return ret; 788 789 memset(es, 0, sizeof(*es)); 790 es->sb = sb; 791 es->modified = false; 792 es->start_off = off; 793 es->bh = es->__bh; 794 795 bh = sb_bread(sb, sec); 796 if (!bh) 797 return -EIO; 798 es->bh[es->num_bh++] = bh; 799 800 if (num_entries == ES_ALL_ENTRIES) { 801 struct exfat_dentry *ep; 802 803 ep = exfat_get_dentry_cached(es, ES_IDX_FILE); 804 if (ep->type != EXFAT_FILE) { 805 brelse(bh); 806 return -EIO; 807 } 808 809 num_entries = ep->dentry.file.num_ext + 1; 810 } 811 812 es->num_entries = num_entries; 813 814 num_bh = EXFAT_B_TO_BLK_ROUND_UP(off + num_entries * DENTRY_SIZE, sb); 815 if (num_bh > ARRAY_SIZE(es->__bh)) { 816 es->bh = kmalloc_array(num_bh, sizeof(*es->bh), GFP_NOFS); 817 if (!es->bh) { 818 brelse(bh); 819 return -ENOMEM; 820 } 821 es->bh[0] = bh; 822 } 823 824 for (i = 1; i < num_bh; i++) { 825 /* get the next sector */ 826 if (exfat_is_last_sector_in_cluster(sbi, sec)) { 827 unsigned int clu = exfat_sector_to_cluster(sbi, sec); 828 829 if (p_dir->flags == ALLOC_NO_FAT_CHAIN) 830 clu++; 831 else if (exfat_get_next_cluster(sb, &clu)) 832 goto put_es; 833 sec = exfat_cluster_to_sector(sbi, clu); 834 } else { 835 sec++; 836 } 837 838 bh = sb_bread(sb, sec); 839 if (!bh) 840 goto put_es; 841 es->bh[es->num_bh++] = bh; 842 } 843 844 return 0; 845 846 put_es: 847 exfat_put_dentry_set(es, false); 848 return -EIO; 849 } 850 851 int exfat_get_dentry_set(struct exfat_entry_set_cache *es, 852 struct super_block *sb, struct exfat_chain *p_dir, 853 int entry, unsigned int num_entries) 854 { 855 int ret, i; 856 struct exfat_dentry *ep; 857 enum exfat_validate_dentry_mode mode = ES_MODE_GET_FILE_ENTRY; 858 859 ret = __exfat_get_dentry_set(es, sb, p_dir, entry, num_entries); 860 if (ret < 0) 861 return ret; 862 863 /* validate cached dentries */ 864 for (i = ES_IDX_STREAM; i < es->num_entries; i++) { 865 ep = exfat_get_dentry_cached(es, i); 866 if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode)) 867 goto put_es; 868 } 869 return 0; 870 871 put_es: 872 exfat_put_dentry_set(es, false); 873 return -EIO; 874 } 875 876 static int exfat_validate_empty_dentry_set(struct exfat_entry_set_cache *es) 877 { 878 struct exfat_dentry *ep; 879 struct buffer_head *bh; 880 int i, off; 881 bool unused_hit = false; 882 883 /* 884 * ONLY UNUSED OR DELETED DENTRIES ARE ALLOWED: 885 * Although it violates the specification for a deleted entry to 886 * follow an unused entry, some exFAT implementations could work 887 * like this. Therefore, to improve compatibility, let's allow it. 888 */ 889 for (i = 0; i < es->num_entries; i++) { 890 ep = exfat_get_dentry_cached(es, i); 891 if (ep->type == EXFAT_UNUSED) { 892 unused_hit = true; 893 } else if (!IS_EXFAT_DELETED(ep->type)) { 894 if (unused_hit) 895 goto err_used_follow_unused; 896 i++; 897 goto count_skip_entries; 898 } 899 } 900 901 return 0; 902 903 err_used_follow_unused: 904 off = es->start_off + (i << DENTRY_SIZE_BITS); 905 bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)]; 906 907 exfat_fs_error(es->sb, 908 "in sector %lld, dentry %d should be unused, but 0x%x", 909 bh->b_blocknr, off >> DENTRY_SIZE_BITS, ep->type); 910 911 return -EIO; 912 913 count_skip_entries: 914 es->num_entries = EXFAT_B_TO_DEN(EXFAT_BLK_TO_B(es->num_bh, es->sb) - es->start_off); 915 for (; i < es->num_entries; i++) { 916 ep = exfat_get_dentry_cached(es, i); 917 if (IS_EXFAT_DELETED(ep->type)) 918 break; 919 } 920 921 return i; 922 } 923 924 /* 925 * Get an empty dentry set. 926 * 927 * in: 928 * sb+p_dir+entry: indicates the empty dentry location 929 * num_entries: specifies how many empty dentries should be included. 930 * out: 931 * es: pointer of empty dentry set on success. 932 * return: 933 * 0 : on success 934 * >0 : the dentries are not empty, the return value is the number of 935 * dentries to be skipped for the next lookup. 936 * <0 : on failure 937 */ 938 int exfat_get_empty_dentry_set(struct exfat_entry_set_cache *es, 939 struct super_block *sb, struct exfat_chain *p_dir, 940 int entry, unsigned int num_entries) 941 { 942 int ret; 943 944 ret = __exfat_get_dentry_set(es, sb, p_dir, entry, num_entries); 945 if (ret < 0) 946 return ret; 947 948 ret = exfat_validate_empty_dentry_set(es); 949 if (ret) 950 exfat_put_dentry_set(es, false); 951 952 return ret; 953 } 954 955 static inline void exfat_reset_empty_hint(struct exfat_hint_femp *hint_femp) 956 { 957 hint_femp->eidx = EXFAT_HINT_NONE; 958 hint_femp->count = 0; 959 } 960 961 static inline void exfat_set_empty_hint(struct exfat_inode_info *ei, 962 struct exfat_hint_femp *candi_empty, struct exfat_chain *clu, 963 int dentry, int num_entries, int entry_type) 964 { 965 if (ei->hint_femp.eidx == EXFAT_HINT_NONE || 966 ei->hint_femp.eidx > dentry) { 967 int total_entries = EXFAT_B_TO_DEN(i_size_read(&ei->vfs_inode)); 968 969 if (candi_empty->count == 0) { 970 candi_empty->cur = *clu; 971 candi_empty->eidx = dentry; 972 } 973 974 if (entry_type == TYPE_UNUSED) 975 candi_empty->count += total_entries - dentry; 976 else 977 candi_empty->count++; 978 979 if (candi_empty->count == num_entries || 980 candi_empty->count + candi_empty->eidx == total_entries) 981 ei->hint_femp = *candi_empty; 982 } 983 } 984 985 enum { 986 DIRENT_STEP_FILE, 987 DIRENT_STEP_STRM, 988 DIRENT_STEP_NAME, 989 DIRENT_STEP_SECD, 990 }; 991 992 /* 993 * @ei: inode info of parent directory 994 * @p_dir: directory structure of parent directory 995 * @num_entries:entry size of p_uniname 996 * @hint_opt: If p_uniname is found, filled with optimized dir/entry 997 * for traversing cluster chain. 998 * @return: 999 * >= 0: file directory entry position where the name exists 1000 * -ENOENT: entry with the name does not exist 1001 * -EIO: I/O error 1002 */ 1003 int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei, 1004 struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname, 1005 struct exfat_hint *hint_opt) 1006 { 1007 int i, rewind = 0, dentry = 0, end_eidx = 0, num_ext = 0, len; 1008 int order, step, name_len = 0; 1009 int dentries_per_clu; 1010 unsigned int entry_type; 1011 unsigned short *uniname = NULL; 1012 struct exfat_chain clu; 1013 struct exfat_hint *hint_stat = &ei->hint_stat; 1014 struct exfat_hint_femp candi_empty; 1015 struct exfat_sb_info *sbi = EXFAT_SB(sb); 1016 int num_entries = exfat_calc_num_entries(p_uniname); 1017 1018 if (num_entries < 0) 1019 return num_entries; 1020 1021 dentries_per_clu = sbi->dentries_per_clu; 1022 1023 exfat_chain_dup(&clu, p_dir); 1024 1025 if (hint_stat->eidx) { 1026 clu.dir = hint_stat->clu; 1027 dentry = hint_stat->eidx; 1028 end_eidx = dentry; 1029 } 1030 1031 exfat_reset_empty_hint(&ei->hint_femp); 1032 1033 rewind: 1034 order = 0; 1035 step = DIRENT_STEP_FILE; 1036 exfat_reset_empty_hint(&candi_empty); 1037 1038 while (clu.dir != EXFAT_EOF_CLUSTER) { 1039 i = dentry & (dentries_per_clu - 1); 1040 for (; i < dentries_per_clu; i++, dentry++) { 1041 struct exfat_dentry *ep; 1042 struct buffer_head *bh; 1043 1044 if (rewind && dentry == end_eidx) 1045 goto not_found; 1046 1047 ep = exfat_get_dentry(sb, &clu, i, &bh); 1048 if (!ep) 1049 return -EIO; 1050 1051 entry_type = exfat_get_entry_type(ep); 1052 1053 if (entry_type == TYPE_UNUSED || 1054 entry_type == TYPE_DELETED) { 1055 step = DIRENT_STEP_FILE; 1056 1057 exfat_set_empty_hint(ei, &candi_empty, &clu, 1058 dentry, num_entries, 1059 entry_type); 1060 1061 brelse(bh); 1062 if (entry_type == TYPE_UNUSED) 1063 goto not_found; 1064 continue; 1065 } 1066 1067 exfat_reset_empty_hint(&candi_empty); 1068 1069 if (entry_type == TYPE_FILE || entry_type == TYPE_DIR) { 1070 step = DIRENT_STEP_FILE; 1071 hint_opt->clu = clu.dir; 1072 hint_opt->eidx = i; 1073 num_ext = ep->dentry.file.num_ext; 1074 step = DIRENT_STEP_STRM; 1075 brelse(bh); 1076 continue; 1077 } 1078 1079 if (entry_type == TYPE_STREAM) { 1080 u16 name_hash; 1081 1082 if (step != DIRENT_STEP_STRM) { 1083 step = DIRENT_STEP_FILE; 1084 brelse(bh); 1085 continue; 1086 } 1087 step = DIRENT_STEP_FILE; 1088 name_hash = le16_to_cpu( 1089 ep->dentry.stream.name_hash); 1090 if (p_uniname->name_hash == name_hash && 1091 p_uniname->name_len == 1092 ep->dentry.stream.name_len) { 1093 step = DIRENT_STEP_NAME; 1094 order = 1; 1095 name_len = 0; 1096 } 1097 brelse(bh); 1098 continue; 1099 } 1100 1101 brelse(bh); 1102 if (entry_type == TYPE_EXTEND) { 1103 unsigned short entry_uniname[16], unichar; 1104 1105 if (step != DIRENT_STEP_NAME || 1106 name_len >= MAX_NAME_LENGTH) { 1107 step = DIRENT_STEP_FILE; 1108 continue; 1109 } 1110 1111 if (++order == 2) 1112 uniname = p_uniname->name; 1113 else 1114 uniname += EXFAT_FILE_NAME_LEN; 1115 1116 len = exfat_extract_uni_name(ep, entry_uniname); 1117 name_len += len; 1118 1119 unichar = *(uniname+len); 1120 *(uniname+len) = 0x0; 1121 1122 if (exfat_uniname_ncmp(sb, uniname, 1123 entry_uniname, len)) { 1124 step = DIRENT_STEP_FILE; 1125 } else if (p_uniname->name_len == name_len) { 1126 if (order == num_ext) 1127 goto found; 1128 step = DIRENT_STEP_SECD; 1129 } 1130 1131 *(uniname+len) = unichar; 1132 continue; 1133 } 1134 1135 if (entry_type & 1136 (TYPE_CRITICAL_SEC | TYPE_BENIGN_SEC)) { 1137 if (step == DIRENT_STEP_SECD) { 1138 if (++order == num_ext) 1139 goto found; 1140 continue; 1141 } 1142 } 1143 step = DIRENT_STEP_FILE; 1144 } 1145 1146 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1147 if (--clu.size > 0) 1148 clu.dir++; 1149 else 1150 clu.dir = EXFAT_EOF_CLUSTER; 1151 } else { 1152 if (exfat_get_next_cluster(sb, &clu.dir)) 1153 return -EIO; 1154 } 1155 } 1156 1157 not_found: 1158 /* 1159 * We started at not 0 index,so we should try to find target 1160 * from 0 index to the index we started at. 1161 */ 1162 if (!rewind && end_eidx) { 1163 rewind = 1; 1164 dentry = 0; 1165 clu.dir = p_dir->dir; 1166 goto rewind; 1167 } 1168 1169 /* 1170 * set the EXFAT_EOF_CLUSTER flag to avoid search 1171 * from the beginning again when allocated a new cluster 1172 */ 1173 if (ei->hint_femp.eidx == EXFAT_HINT_NONE) { 1174 ei->hint_femp.cur.dir = EXFAT_EOF_CLUSTER; 1175 ei->hint_femp.eidx = p_dir->size * dentries_per_clu; 1176 ei->hint_femp.count = 0; 1177 } 1178 1179 /* initialized hint_stat */ 1180 hint_stat->clu = p_dir->dir; 1181 hint_stat->eidx = 0; 1182 return -ENOENT; 1183 1184 found: 1185 /* next dentry we'll find is out of this cluster */ 1186 if (!((dentry + 1) & (dentries_per_clu - 1))) { 1187 int ret = 0; 1188 1189 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1190 if (--clu.size > 0) 1191 clu.dir++; 1192 else 1193 clu.dir = EXFAT_EOF_CLUSTER; 1194 } else { 1195 ret = exfat_get_next_cluster(sb, &clu.dir); 1196 } 1197 1198 if (ret || clu.dir == EXFAT_EOF_CLUSTER) { 1199 /* just initialized hint_stat */ 1200 hint_stat->clu = p_dir->dir; 1201 hint_stat->eidx = 0; 1202 return (dentry - num_ext); 1203 } 1204 } 1205 1206 hint_stat->clu = clu.dir; 1207 hint_stat->eidx = dentry + 1; 1208 return dentry - num_ext; 1209 } 1210 1211 int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir) 1212 { 1213 int i, count = 0; 1214 int dentries_per_clu; 1215 unsigned int entry_type; 1216 struct exfat_chain clu; 1217 struct exfat_dentry *ep; 1218 struct exfat_sb_info *sbi = EXFAT_SB(sb); 1219 struct buffer_head *bh; 1220 1221 dentries_per_clu = sbi->dentries_per_clu; 1222 1223 exfat_chain_dup(&clu, p_dir); 1224 1225 while (clu.dir != EXFAT_EOF_CLUSTER) { 1226 for (i = 0; i < dentries_per_clu; i++) { 1227 ep = exfat_get_dentry(sb, &clu, i, &bh); 1228 if (!ep) 1229 return -EIO; 1230 entry_type = exfat_get_entry_type(ep); 1231 brelse(bh); 1232 1233 if (entry_type == TYPE_UNUSED) 1234 return count; 1235 if (entry_type != TYPE_DIR) 1236 continue; 1237 count++; 1238 } 1239 1240 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 1241 if (--clu.size > 0) 1242 clu.dir++; 1243 else 1244 clu.dir = EXFAT_EOF_CLUSTER; 1245 } else { 1246 if (exfat_get_next_cluster(sb, &(clu.dir))) 1247 return -EIO; 1248 } 1249 } 1250 1251 return count; 1252 } 1253