1 /* 2 * fs/f2fs/dir.c 3 * 4 * Copyright (c) 2012 Samsung Electronics Co., Ltd. 5 * http://www.samsung.com/ 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 */ 11 #include <linux/fs.h> 12 #include <linux/f2fs_fs.h> 13 #include "f2fs.h" 14 #include "node.h" 15 #include "acl.h" 16 #include "xattr.h" 17 18 static unsigned long dir_blocks(struct inode *inode) 19 { 20 return ((unsigned long long) (i_size_read(inode) + PAGE_CACHE_SIZE - 1)) 21 >> PAGE_CACHE_SHIFT; 22 } 23 24 static unsigned int dir_buckets(unsigned int level) 25 { 26 if (level < MAX_DIR_HASH_DEPTH / 2) 27 return 1 << level; 28 else 29 return 1 << ((MAX_DIR_HASH_DEPTH / 2) - 1); 30 } 31 32 static unsigned int bucket_blocks(unsigned int level) 33 { 34 if (level < MAX_DIR_HASH_DEPTH / 2) 35 return 2; 36 else 37 return 4; 38 } 39 40 static unsigned char f2fs_filetype_table[F2FS_FT_MAX] = { 41 [F2FS_FT_UNKNOWN] = DT_UNKNOWN, 42 [F2FS_FT_REG_FILE] = DT_REG, 43 [F2FS_FT_DIR] = DT_DIR, 44 [F2FS_FT_CHRDEV] = DT_CHR, 45 [F2FS_FT_BLKDEV] = DT_BLK, 46 [F2FS_FT_FIFO] = DT_FIFO, 47 [F2FS_FT_SOCK] = DT_SOCK, 48 [F2FS_FT_SYMLINK] = DT_LNK, 49 }; 50 51 #define S_SHIFT 12 52 static unsigned char f2fs_type_by_mode[S_IFMT >> S_SHIFT] = { 53 [S_IFREG >> S_SHIFT] = F2FS_FT_REG_FILE, 54 [S_IFDIR >> S_SHIFT] = F2FS_FT_DIR, 55 [S_IFCHR >> S_SHIFT] = F2FS_FT_CHRDEV, 56 [S_IFBLK >> S_SHIFT] = F2FS_FT_BLKDEV, 57 [S_IFIFO >> S_SHIFT] = F2FS_FT_FIFO, 58 [S_IFSOCK >> S_SHIFT] = F2FS_FT_SOCK, 59 [S_IFLNK >> S_SHIFT] = F2FS_FT_SYMLINK, 60 }; 61 62 static void set_de_type(struct f2fs_dir_entry *de, struct inode *inode) 63 { 64 umode_t mode = inode->i_mode; 65 de->file_type = f2fs_type_by_mode[(mode & S_IFMT) >> S_SHIFT]; 66 } 67 68 static unsigned long dir_block_index(unsigned int level, unsigned int idx) 69 { 70 unsigned long i; 71 unsigned long bidx = 0; 72 73 for (i = 0; i < level; i++) 74 bidx += dir_buckets(i) * bucket_blocks(i); 75 bidx += idx * bucket_blocks(level); 76 return bidx; 77 } 78 79 static bool early_match_name(const char *name, size_t namelen, 80 f2fs_hash_t namehash, struct f2fs_dir_entry *de) 81 { 82 if (le16_to_cpu(de->name_len) != namelen) 83 return false; 84 85 if (de->hash_code != namehash) 86 return false; 87 88 return true; 89 } 90 91 static struct f2fs_dir_entry *find_in_block(struct page *dentry_page, 92 const char *name, size_t namelen, int *max_slots, 93 f2fs_hash_t namehash, struct page **res_page) 94 { 95 struct f2fs_dir_entry *de; 96 unsigned long bit_pos, end_pos, next_pos; 97 struct f2fs_dentry_block *dentry_blk = kmap(dentry_page); 98 int slots; 99 100 bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap, 101 NR_DENTRY_IN_BLOCK, 0); 102 while (bit_pos < NR_DENTRY_IN_BLOCK) { 103 de = &dentry_blk->dentry[bit_pos]; 104 slots = GET_DENTRY_SLOTS(le16_to_cpu(de->name_len)); 105 106 if (early_match_name(name, namelen, namehash, de)) { 107 if (!memcmp(dentry_blk->filename[bit_pos], 108 name, namelen)) { 109 *res_page = dentry_page; 110 goto found; 111 } 112 } 113 next_pos = bit_pos + slots; 114 bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap, 115 NR_DENTRY_IN_BLOCK, next_pos); 116 if (bit_pos >= NR_DENTRY_IN_BLOCK) 117 end_pos = NR_DENTRY_IN_BLOCK; 118 else 119 end_pos = bit_pos; 120 if (*max_slots < end_pos - next_pos) 121 *max_slots = end_pos - next_pos; 122 } 123 124 de = NULL; 125 kunmap(dentry_page); 126 found: 127 return de; 128 } 129 130 static struct f2fs_dir_entry *find_in_level(struct inode *dir, 131 unsigned int level, const char *name, size_t namelen, 132 f2fs_hash_t namehash, struct page **res_page) 133 { 134 int s = GET_DENTRY_SLOTS(namelen); 135 unsigned int nbucket, nblock; 136 unsigned int bidx, end_block; 137 struct page *dentry_page; 138 struct f2fs_dir_entry *de = NULL; 139 bool room = false; 140 int max_slots = 0; 141 142 f2fs_bug_on(level > MAX_DIR_HASH_DEPTH); 143 144 nbucket = dir_buckets(level); 145 nblock = bucket_blocks(level); 146 147 bidx = dir_block_index(level, le32_to_cpu(namehash) % nbucket); 148 end_block = bidx + nblock; 149 150 for (; bidx < end_block; bidx++) { 151 /* no need to allocate new dentry pages to all the indices */ 152 dentry_page = find_data_page(dir, bidx, true); 153 if (IS_ERR(dentry_page)) { 154 room = true; 155 continue; 156 } 157 158 de = find_in_block(dentry_page, name, namelen, 159 &max_slots, namehash, res_page); 160 if (de) 161 break; 162 163 if (max_slots >= s) 164 room = true; 165 f2fs_put_page(dentry_page, 0); 166 } 167 168 if (!de && room && F2FS_I(dir)->chash != namehash) { 169 F2FS_I(dir)->chash = namehash; 170 F2FS_I(dir)->clevel = level; 171 } 172 173 return de; 174 } 175 176 /* 177 * Find an entry in the specified directory with the wanted name. 178 * It returns the page where the entry was found (as a parameter - res_page), 179 * and the entry itself. Page is returned mapped and unlocked. 180 * Entry is guaranteed to be valid. 181 */ 182 struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir, 183 struct qstr *child, struct page **res_page) 184 { 185 const char *name = child->name; 186 size_t namelen = child->len; 187 unsigned long npages = dir_blocks(dir); 188 struct f2fs_dir_entry *de = NULL; 189 f2fs_hash_t name_hash; 190 unsigned int max_depth; 191 unsigned int level; 192 193 if (npages == 0) 194 return NULL; 195 196 *res_page = NULL; 197 198 name_hash = f2fs_dentry_hash(name, namelen); 199 max_depth = F2FS_I(dir)->i_current_depth; 200 201 for (level = 0; level < max_depth; level++) { 202 de = find_in_level(dir, level, name, 203 namelen, name_hash, res_page); 204 if (de) 205 break; 206 } 207 if (!de && F2FS_I(dir)->chash != name_hash) { 208 F2FS_I(dir)->chash = name_hash; 209 F2FS_I(dir)->clevel = level - 1; 210 } 211 return de; 212 } 213 214 struct f2fs_dir_entry *f2fs_parent_dir(struct inode *dir, struct page **p) 215 { 216 struct page *page; 217 struct f2fs_dir_entry *de; 218 struct f2fs_dentry_block *dentry_blk; 219 220 page = get_lock_data_page(dir, 0); 221 if (IS_ERR(page)) 222 return NULL; 223 224 dentry_blk = kmap(page); 225 de = &dentry_blk->dentry[1]; 226 *p = page; 227 unlock_page(page); 228 return de; 229 } 230 231 ino_t f2fs_inode_by_name(struct inode *dir, struct qstr *qstr) 232 { 233 ino_t res = 0; 234 struct f2fs_dir_entry *de; 235 struct page *page; 236 237 de = f2fs_find_entry(dir, qstr, &page); 238 if (de) { 239 res = le32_to_cpu(de->ino); 240 kunmap(page); 241 f2fs_put_page(page, 0); 242 } 243 244 return res; 245 } 246 247 void f2fs_set_link(struct inode *dir, struct f2fs_dir_entry *de, 248 struct page *page, struct inode *inode) 249 { 250 lock_page(page); 251 wait_on_page_writeback(page); 252 de->ino = cpu_to_le32(inode->i_ino); 253 set_de_type(de, inode); 254 kunmap(page); 255 set_page_dirty(page); 256 dir->i_mtime = dir->i_ctime = CURRENT_TIME; 257 mark_inode_dirty(dir); 258 259 f2fs_put_page(page, 1); 260 } 261 262 static void init_dent_inode(const struct qstr *name, struct page *ipage) 263 { 264 struct f2fs_inode *ri; 265 266 /* copy name info. to this inode page */ 267 ri = F2FS_INODE(ipage); 268 ri->i_namelen = cpu_to_le32(name->len); 269 memcpy(ri->i_name, name->name, name->len); 270 set_page_dirty(ipage); 271 } 272 273 int update_dent_inode(struct inode *inode, const struct qstr *name) 274 { 275 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); 276 struct page *page; 277 278 page = get_node_page(sbi, inode->i_ino); 279 if (IS_ERR(page)) 280 return PTR_ERR(page); 281 282 init_dent_inode(name, page); 283 f2fs_put_page(page, 1); 284 285 return 0; 286 } 287 288 static int make_empty_dir(struct inode *inode, 289 struct inode *parent, struct page *page) 290 { 291 struct page *dentry_page; 292 struct f2fs_dentry_block *dentry_blk; 293 struct f2fs_dir_entry *de; 294 void *kaddr; 295 296 dentry_page = get_new_data_page(inode, page, 0, true); 297 if (IS_ERR(dentry_page)) 298 return PTR_ERR(dentry_page); 299 300 kaddr = kmap_atomic(dentry_page); 301 dentry_blk = (struct f2fs_dentry_block *)kaddr; 302 303 de = &dentry_blk->dentry[0]; 304 de->name_len = cpu_to_le16(1); 305 de->hash_code = 0; 306 de->ino = cpu_to_le32(inode->i_ino); 307 memcpy(dentry_blk->filename[0], ".", 1); 308 set_de_type(de, inode); 309 310 de = &dentry_blk->dentry[1]; 311 de->hash_code = 0; 312 de->name_len = cpu_to_le16(2); 313 de->ino = cpu_to_le32(parent->i_ino); 314 memcpy(dentry_blk->filename[1], "..", 2); 315 set_de_type(de, inode); 316 317 test_and_set_bit_le(0, &dentry_blk->dentry_bitmap); 318 test_and_set_bit_le(1, &dentry_blk->dentry_bitmap); 319 kunmap_atomic(kaddr); 320 321 set_page_dirty(dentry_page); 322 f2fs_put_page(dentry_page, 1); 323 return 0; 324 } 325 326 static struct page *init_inode_metadata(struct inode *inode, 327 struct inode *dir, const struct qstr *name) 328 { 329 struct page *page; 330 int err; 331 332 if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) { 333 page = new_inode_page(inode, name); 334 if (IS_ERR(page)) 335 return page; 336 337 if (S_ISDIR(inode->i_mode)) { 338 err = make_empty_dir(inode, dir, page); 339 if (err) 340 goto error; 341 } 342 343 err = f2fs_init_acl(inode, dir, page); 344 if (err) 345 goto put_error; 346 347 err = f2fs_init_security(inode, dir, name, page); 348 if (err) 349 goto put_error; 350 351 wait_on_page_writeback(page); 352 } else { 353 page = get_node_page(F2FS_SB(dir->i_sb), inode->i_ino); 354 if (IS_ERR(page)) 355 return page; 356 357 wait_on_page_writeback(page); 358 set_cold_node(inode, page); 359 } 360 361 init_dent_inode(name, page); 362 363 /* 364 * This file should be checkpointed during fsync. 365 * We lost i_pino from now on. 366 */ 367 if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK)) { 368 file_lost_pino(inode); 369 inc_nlink(inode); 370 } 371 return page; 372 373 put_error: 374 f2fs_put_page(page, 1); 375 /* once the failed inode becomes a bad inode, i_mode is S_IFREG */ 376 truncate_inode_pages(&inode->i_data, 0); 377 truncate_blocks(inode, 0); 378 remove_dirty_dir_inode(inode); 379 error: 380 remove_inode_page(inode); 381 return ERR_PTR(err); 382 } 383 384 static void update_parent_metadata(struct inode *dir, struct inode *inode, 385 unsigned int current_depth) 386 { 387 if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) { 388 if (S_ISDIR(inode->i_mode)) { 389 inc_nlink(dir); 390 set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR); 391 } 392 clear_inode_flag(F2FS_I(inode), FI_NEW_INODE); 393 } 394 dir->i_mtime = dir->i_ctime = CURRENT_TIME; 395 mark_inode_dirty(dir); 396 397 if (F2FS_I(dir)->i_current_depth != current_depth) { 398 F2FS_I(dir)->i_current_depth = current_depth; 399 set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR); 400 } 401 402 if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK)) 403 clear_inode_flag(F2FS_I(inode), FI_INC_LINK); 404 } 405 406 static int room_for_filename(struct f2fs_dentry_block *dentry_blk, int slots) 407 { 408 int bit_start = 0; 409 int zero_start, zero_end; 410 next: 411 zero_start = find_next_zero_bit_le(&dentry_blk->dentry_bitmap, 412 NR_DENTRY_IN_BLOCK, 413 bit_start); 414 if (zero_start >= NR_DENTRY_IN_BLOCK) 415 return NR_DENTRY_IN_BLOCK; 416 417 zero_end = find_next_bit_le(&dentry_blk->dentry_bitmap, 418 NR_DENTRY_IN_BLOCK, 419 zero_start); 420 if (zero_end - zero_start >= slots) 421 return zero_start; 422 423 bit_start = zero_end + 1; 424 425 if (zero_end + 1 >= NR_DENTRY_IN_BLOCK) 426 return NR_DENTRY_IN_BLOCK; 427 goto next; 428 } 429 430 /* 431 * Caller should grab and release a rwsem by calling f2fs_lock_op() and 432 * f2fs_unlock_op(). 433 */ 434 int __f2fs_add_link(struct inode *dir, const struct qstr *name, 435 struct inode *inode) 436 { 437 unsigned int bit_pos; 438 unsigned int level; 439 unsigned int current_depth; 440 unsigned long bidx, block; 441 f2fs_hash_t dentry_hash; 442 struct f2fs_dir_entry *de; 443 unsigned int nbucket, nblock; 444 size_t namelen = name->len; 445 struct page *dentry_page = NULL; 446 struct f2fs_dentry_block *dentry_blk = NULL; 447 int slots = GET_DENTRY_SLOTS(namelen); 448 struct page *page; 449 int err = 0; 450 int i; 451 452 dentry_hash = f2fs_dentry_hash(name->name, name->len); 453 level = 0; 454 current_depth = F2FS_I(dir)->i_current_depth; 455 if (F2FS_I(dir)->chash == dentry_hash) { 456 level = F2FS_I(dir)->clevel; 457 F2FS_I(dir)->chash = 0; 458 } 459 460 start: 461 if (unlikely(current_depth == MAX_DIR_HASH_DEPTH)) 462 return -ENOSPC; 463 464 /* Increase the depth, if required */ 465 if (level == current_depth) 466 ++current_depth; 467 468 nbucket = dir_buckets(level); 469 nblock = bucket_blocks(level); 470 471 bidx = dir_block_index(level, (le32_to_cpu(dentry_hash) % nbucket)); 472 473 for (block = bidx; block <= (bidx + nblock - 1); block++) { 474 dentry_page = get_new_data_page(dir, NULL, block, true); 475 if (IS_ERR(dentry_page)) 476 return PTR_ERR(dentry_page); 477 478 dentry_blk = kmap(dentry_page); 479 bit_pos = room_for_filename(dentry_blk, slots); 480 if (bit_pos < NR_DENTRY_IN_BLOCK) 481 goto add_dentry; 482 483 kunmap(dentry_page); 484 f2fs_put_page(dentry_page, 1); 485 } 486 487 /* Move to next level to find the empty slot for new dentry */ 488 ++level; 489 goto start; 490 add_dentry: 491 wait_on_page_writeback(dentry_page); 492 493 page = init_inode_metadata(inode, dir, name); 494 if (IS_ERR(page)) { 495 err = PTR_ERR(page); 496 goto fail; 497 } 498 de = &dentry_blk->dentry[bit_pos]; 499 de->hash_code = dentry_hash; 500 de->name_len = cpu_to_le16(namelen); 501 memcpy(dentry_blk->filename[bit_pos], name->name, name->len); 502 de->ino = cpu_to_le32(inode->i_ino); 503 set_de_type(de, inode); 504 for (i = 0; i < slots; i++) 505 test_and_set_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap); 506 set_page_dirty(dentry_page); 507 508 /* we don't need to mark_inode_dirty now */ 509 F2FS_I(inode)->i_pino = dir->i_ino; 510 update_inode(inode, page); 511 f2fs_put_page(page, 1); 512 513 update_parent_metadata(dir, inode, current_depth); 514 fail: 515 if (is_inode_flag_set(F2FS_I(dir), FI_UPDATE_DIR)) { 516 update_inode_page(dir); 517 clear_inode_flag(F2FS_I(dir), FI_UPDATE_DIR); 518 } 519 kunmap(dentry_page); 520 f2fs_put_page(dentry_page, 1); 521 return err; 522 } 523 524 /* 525 * It only removes the dentry from the dentry page,corresponding name 526 * entry in name page does not need to be touched during deletion. 527 */ 528 void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page, 529 struct inode *inode) 530 { 531 struct f2fs_dentry_block *dentry_blk; 532 unsigned int bit_pos; 533 struct address_space *mapping = page->mapping; 534 struct inode *dir = mapping->host; 535 int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len)); 536 void *kaddr = page_address(page); 537 int i; 538 539 lock_page(page); 540 wait_on_page_writeback(page); 541 542 dentry_blk = (struct f2fs_dentry_block *)kaddr; 543 bit_pos = dentry - (struct f2fs_dir_entry *)dentry_blk->dentry; 544 for (i = 0; i < slots; i++) 545 test_and_clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap); 546 547 /* Let's check and deallocate this dentry page */ 548 bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap, 549 NR_DENTRY_IN_BLOCK, 550 0); 551 kunmap(page); /* kunmap - pair of f2fs_find_entry */ 552 set_page_dirty(page); 553 554 dir->i_ctime = dir->i_mtime = CURRENT_TIME; 555 556 if (inode) { 557 struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb); 558 559 if (S_ISDIR(inode->i_mode)) { 560 drop_nlink(dir); 561 update_inode_page(dir); 562 } 563 inode->i_ctime = CURRENT_TIME; 564 drop_nlink(inode); 565 if (S_ISDIR(inode->i_mode)) { 566 drop_nlink(inode); 567 i_size_write(inode, 0); 568 } 569 update_inode_page(inode); 570 571 if (inode->i_nlink == 0) 572 add_orphan_inode(sbi, inode->i_ino); 573 else 574 release_orphan_inode(sbi); 575 } 576 577 if (bit_pos == NR_DENTRY_IN_BLOCK) { 578 truncate_hole(dir, page->index, page->index + 1); 579 clear_page_dirty_for_io(page); 580 ClearPageUptodate(page); 581 inode_dec_dirty_dents(dir); 582 } 583 f2fs_put_page(page, 1); 584 } 585 586 bool f2fs_empty_dir(struct inode *dir) 587 { 588 unsigned long bidx; 589 struct page *dentry_page; 590 unsigned int bit_pos; 591 struct f2fs_dentry_block *dentry_blk; 592 unsigned long nblock = dir_blocks(dir); 593 594 for (bidx = 0; bidx < nblock; bidx++) { 595 void *kaddr; 596 dentry_page = get_lock_data_page(dir, bidx); 597 if (IS_ERR(dentry_page)) { 598 if (PTR_ERR(dentry_page) == -ENOENT) 599 continue; 600 else 601 return false; 602 } 603 604 kaddr = kmap_atomic(dentry_page); 605 dentry_blk = (struct f2fs_dentry_block *)kaddr; 606 if (bidx == 0) 607 bit_pos = 2; 608 else 609 bit_pos = 0; 610 bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap, 611 NR_DENTRY_IN_BLOCK, 612 bit_pos); 613 kunmap_atomic(kaddr); 614 615 f2fs_put_page(dentry_page, 1); 616 617 if (bit_pos < NR_DENTRY_IN_BLOCK) 618 return false; 619 } 620 return true; 621 } 622 623 static int f2fs_readdir(struct file *file, struct dir_context *ctx) 624 { 625 struct inode *inode = file_inode(file); 626 unsigned long npages = dir_blocks(inode); 627 unsigned int bit_pos = 0; 628 struct f2fs_dentry_block *dentry_blk = NULL; 629 struct f2fs_dir_entry *de = NULL; 630 struct page *dentry_page = NULL; 631 unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK); 632 unsigned char d_type = DT_UNKNOWN; 633 634 bit_pos = ((unsigned long)ctx->pos % NR_DENTRY_IN_BLOCK); 635 636 for (; n < npages; n++) { 637 dentry_page = get_lock_data_page(inode, n); 638 if (IS_ERR(dentry_page)) 639 continue; 640 641 dentry_blk = kmap(dentry_page); 642 while (bit_pos < NR_DENTRY_IN_BLOCK) { 643 bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap, 644 NR_DENTRY_IN_BLOCK, 645 bit_pos); 646 if (bit_pos >= NR_DENTRY_IN_BLOCK) 647 break; 648 649 de = &dentry_blk->dentry[bit_pos]; 650 if (de->file_type < F2FS_FT_MAX) 651 d_type = f2fs_filetype_table[de->file_type]; 652 else 653 d_type = DT_UNKNOWN; 654 if (!dir_emit(ctx, 655 dentry_blk->filename[bit_pos], 656 le16_to_cpu(de->name_len), 657 le32_to_cpu(de->ino), d_type)) 658 goto stop; 659 660 bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len)); 661 ctx->pos = n * NR_DENTRY_IN_BLOCK + bit_pos; 662 } 663 bit_pos = 0; 664 ctx->pos = (n + 1) * NR_DENTRY_IN_BLOCK; 665 kunmap(dentry_page); 666 f2fs_put_page(dentry_page, 1); 667 dentry_page = NULL; 668 } 669 stop: 670 if (dentry_page && !IS_ERR(dentry_page)) { 671 kunmap(dentry_page); 672 f2fs_put_page(dentry_page, 1); 673 } 674 675 return 0; 676 } 677 678 const struct file_operations f2fs_dir_operations = { 679 .llseek = generic_file_llseek, 680 .read = generic_read_dir, 681 .iterate = f2fs_readdir, 682 .fsync = f2fs_sync_file, 683 .unlocked_ioctl = f2fs_ioctl, 684 }; 685