1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/fs/ext4/namei.c 4 * 5 * Copyright (C) 1992, 1993, 1994, 1995 6 * Remy Card (card@masi.ibp.fr) 7 * Laboratoire MASI - Institut Blaise Pascal 8 * Universite Pierre et Marie Curie (Paris VI) 9 * 10 * from 11 * 12 * linux/fs/minix/namei.c 13 * 14 * Copyright (C) 1991, 1992 Linus Torvalds 15 * 16 * Big-endian to little-endian byte-swapping/bitmaps by 17 * David S. Miller (davem@caip.rutgers.edu), 1995 18 * Directory entry file type support and forward compatibility hooks 19 * for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998 20 * Hash Tree Directory indexing (c) 21 * Daniel Phillips, 2001 22 * Hash Tree Directory indexing porting 23 * Christopher Li, 2002 24 * Hash Tree Directory indexing cleanup 25 * Theodore Ts'o, 2002 26 */ 27 28 #include <linux/fs.h> 29 #include <linux/pagemap.h> 30 #include <linux/time.h> 31 #include <linux/fcntl.h> 32 #include <linux/stat.h> 33 #include <linux/string.h> 34 #include <linux/quotaops.h> 35 #include <linux/buffer_head.h> 36 #include <linux/bio.h> 37 #include <linux/iversion.h> 38 #include "ext4.h" 39 #include "ext4_jbd2.h" 40 41 #include "xattr.h" 42 #include "acl.h" 43 44 #include <trace/events/ext4.h> 45 /* 46 * define how far ahead to read directories while searching them. 47 */ 48 #define NAMEI_RA_CHUNKS 2 49 #define NAMEI_RA_BLOCKS 4 50 #define NAMEI_RA_SIZE (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS) 51 52 static struct buffer_head *ext4_append(handle_t *handle, 53 struct inode *inode, 54 ext4_lblk_t *block) 55 { 56 struct buffer_head *bh; 57 int err; 58 59 if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb && 60 ((inode->i_size >> 10) >= 61 EXT4_SB(inode->i_sb)->s_max_dir_size_kb))) 62 return ERR_PTR(-ENOSPC); 63 64 *block = inode->i_size >> inode->i_sb->s_blocksize_bits; 65 66 bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE); 67 if (IS_ERR(bh)) 68 return bh; 69 inode->i_size += inode->i_sb->s_blocksize; 70 EXT4_I(inode)->i_disksize = inode->i_size; 71 BUFFER_TRACE(bh, "get_write_access"); 72 err = ext4_journal_get_write_access(handle, bh); 73 if (err) { 74 brelse(bh); 75 ext4_std_error(inode->i_sb, err); 76 return ERR_PTR(err); 77 } 78 return bh; 79 } 80 81 static int ext4_dx_csum_verify(struct inode *inode, 82 struct ext4_dir_entry *dirent); 83 84 typedef enum { 85 EITHER, INDEX, DIRENT 86 } dirblock_type_t; 87 88 #define ext4_read_dirblock(inode, block, type) \ 89 __ext4_read_dirblock((inode), (block), (type), __func__, __LINE__) 90 91 static struct buffer_head *__ext4_read_dirblock(struct inode *inode, 92 ext4_lblk_t block, 93 dirblock_type_t type, 94 const char *func, 95 unsigned int line) 96 { 97 struct buffer_head *bh; 98 struct ext4_dir_entry *dirent; 99 int is_dx_block = 0; 100 101 bh = ext4_bread(NULL, inode, block, 0); 102 if (IS_ERR(bh)) { 103 __ext4_warning(inode->i_sb, func, line, 104 "inode #%lu: lblock %lu: comm %s: " 105 "error %ld reading directory block", 106 inode->i_ino, (unsigned long)block, 107 current->comm, PTR_ERR(bh)); 108 109 return bh; 110 } 111 if (!bh) { 112 ext4_error_inode(inode, func, line, block, 113 "Directory hole found"); 114 return ERR_PTR(-EFSCORRUPTED); 115 } 116 dirent = (struct ext4_dir_entry *) bh->b_data; 117 /* Determine whether or not we have an index block */ 118 if (is_dx(inode)) { 119 if (block == 0) 120 is_dx_block = 1; 121 else if (ext4_rec_len_from_disk(dirent->rec_len, 122 inode->i_sb->s_blocksize) == 123 inode->i_sb->s_blocksize) 124 is_dx_block = 1; 125 } 126 if (!is_dx_block && type == INDEX) { 127 ext4_error_inode(inode, func, line, block, 128 "directory leaf block found instead of index block"); 129 return ERR_PTR(-EFSCORRUPTED); 130 } 131 if (!ext4_has_metadata_csum(inode->i_sb) || 132 buffer_verified(bh)) 133 return bh; 134 135 /* 136 * An empty leaf block can get mistaken for a index block; for 137 * this reason, we can only check the index checksum when the 138 * caller is sure it should be an index block. 139 */ 140 if (is_dx_block && type == INDEX) { 141 if (ext4_dx_csum_verify(inode, dirent)) 142 set_buffer_verified(bh); 143 else { 144 ext4_error_inode(inode, func, line, block, 145 "Directory index failed checksum"); 146 brelse(bh); 147 return ERR_PTR(-EFSBADCRC); 148 } 149 } 150 if (!is_dx_block) { 151 if (ext4_dirent_csum_verify(inode, dirent)) 152 set_buffer_verified(bh); 153 else { 154 ext4_error_inode(inode, func, line, block, 155 "Directory block failed checksum"); 156 brelse(bh); 157 return ERR_PTR(-EFSBADCRC); 158 } 159 } 160 return bh; 161 } 162 163 #ifndef assert 164 #define assert(test) J_ASSERT(test) 165 #endif 166 167 #ifdef DX_DEBUG 168 #define dxtrace(command) command 169 #else 170 #define dxtrace(command) 171 #endif 172 173 struct fake_dirent 174 { 175 __le32 inode; 176 __le16 rec_len; 177 u8 name_len; 178 u8 file_type; 179 }; 180 181 struct dx_countlimit 182 { 183 __le16 limit; 184 __le16 count; 185 }; 186 187 struct dx_entry 188 { 189 __le32 hash; 190 __le32 block; 191 }; 192 193 /* 194 * dx_root_info is laid out so that if it should somehow get overlaid by a 195 * dirent the two low bits of the hash version will be zero. Therefore, the 196 * hash version mod 4 should never be 0. Sincerely, the paranoia department. 197 */ 198 199 struct dx_root 200 { 201 struct fake_dirent dot; 202 char dot_name[4]; 203 struct fake_dirent dotdot; 204 char dotdot_name[4]; 205 struct dx_root_info 206 { 207 __le32 reserved_zero; 208 u8 hash_version; 209 u8 info_length; /* 8 */ 210 u8 indirect_levels; 211 u8 unused_flags; 212 } 213 info; 214 struct dx_entry entries[0]; 215 }; 216 217 struct dx_node 218 { 219 struct fake_dirent fake; 220 struct dx_entry entries[0]; 221 }; 222 223 224 struct dx_frame 225 { 226 struct buffer_head *bh; 227 struct dx_entry *entries; 228 struct dx_entry *at; 229 }; 230 231 struct dx_map_entry 232 { 233 u32 hash; 234 u16 offs; 235 u16 size; 236 }; 237 238 /* 239 * This goes at the end of each htree block. 240 */ 241 struct dx_tail { 242 u32 dt_reserved; 243 __le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */ 244 }; 245 246 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry); 247 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value); 248 static inline unsigned dx_get_hash(struct dx_entry *entry); 249 static void dx_set_hash(struct dx_entry *entry, unsigned value); 250 static unsigned dx_get_count(struct dx_entry *entries); 251 static unsigned dx_get_limit(struct dx_entry *entries); 252 static void dx_set_count(struct dx_entry *entries, unsigned value); 253 static void dx_set_limit(struct dx_entry *entries, unsigned value); 254 static unsigned dx_root_limit(struct inode *dir, unsigned infosize); 255 static unsigned dx_node_limit(struct inode *dir); 256 static struct dx_frame *dx_probe(struct ext4_filename *fname, 257 struct inode *dir, 258 struct dx_hash_info *hinfo, 259 struct dx_frame *frame); 260 static void dx_release(struct dx_frame *frames); 261 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de, 262 unsigned blocksize, struct dx_hash_info *hinfo, 263 struct dx_map_entry map[]); 264 static void dx_sort_map(struct dx_map_entry *map, unsigned count); 265 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to, 266 struct dx_map_entry *offsets, int count, unsigned blocksize); 267 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize); 268 static void dx_insert_block(struct dx_frame *frame, 269 u32 hash, ext4_lblk_t block); 270 static int ext4_htree_next_block(struct inode *dir, __u32 hash, 271 struct dx_frame *frame, 272 struct dx_frame *frames, 273 __u32 *start_hash); 274 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, 275 struct ext4_filename *fname, 276 struct ext4_dir_entry_2 **res_dir); 277 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname, 278 struct inode *dir, struct inode *inode); 279 280 /* checksumming functions */ 281 void initialize_dirent_tail(struct ext4_dir_entry_tail *t, 282 unsigned int blocksize) 283 { 284 memset(t, 0, sizeof(struct ext4_dir_entry_tail)); 285 t->det_rec_len = ext4_rec_len_to_disk( 286 sizeof(struct ext4_dir_entry_tail), blocksize); 287 t->det_reserved_ft = EXT4_FT_DIR_CSUM; 288 } 289 290 /* Walk through a dirent block to find a checksum "dirent" at the tail */ 291 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode, 292 struct ext4_dir_entry *de) 293 { 294 struct ext4_dir_entry_tail *t; 295 296 #ifdef PARANOID 297 struct ext4_dir_entry *d, *top; 298 299 d = de; 300 top = (struct ext4_dir_entry *)(((void *)de) + 301 (EXT4_BLOCK_SIZE(inode->i_sb) - 302 sizeof(struct ext4_dir_entry_tail))); 303 while (d < top && d->rec_len) 304 d = (struct ext4_dir_entry *)(((void *)d) + 305 le16_to_cpu(d->rec_len)); 306 307 if (d != top) 308 return NULL; 309 310 t = (struct ext4_dir_entry_tail *)d; 311 #else 312 t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb)); 313 #endif 314 315 if (t->det_reserved_zero1 || 316 le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) || 317 t->det_reserved_zero2 || 318 t->det_reserved_ft != EXT4_FT_DIR_CSUM) 319 return NULL; 320 321 return t; 322 } 323 324 static __le32 ext4_dirent_csum(struct inode *inode, 325 struct ext4_dir_entry *dirent, int size) 326 { 327 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 328 struct ext4_inode_info *ei = EXT4_I(inode); 329 __u32 csum; 330 331 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size); 332 return cpu_to_le32(csum); 333 } 334 335 #define warn_no_space_for_csum(inode) \ 336 __warn_no_space_for_csum((inode), __func__, __LINE__) 337 338 static void __warn_no_space_for_csum(struct inode *inode, const char *func, 339 unsigned int line) 340 { 341 __ext4_warning_inode(inode, func, line, 342 "No space for directory leaf checksum. Please run e2fsck -D."); 343 } 344 345 int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent) 346 { 347 struct ext4_dir_entry_tail *t; 348 349 if (!ext4_has_metadata_csum(inode->i_sb)) 350 return 1; 351 352 t = get_dirent_tail(inode, dirent); 353 if (!t) { 354 warn_no_space_for_csum(inode); 355 return 0; 356 } 357 358 if (t->det_checksum != ext4_dirent_csum(inode, dirent, 359 (void *)t - (void *)dirent)) 360 return 0; 361 362 return 1; 363 } 364 365 static void ext4_dirent_csum_set(struct inode *inode, 366 struct ext4_dir_entry *dirent) 367 { 368 struct ext4_dir_entry_tail *t; 369 370 if (!ext4_has_metadata_csum(inode->i_sb)) 371 return; 372 373 t = get_dirent_tail(inode, dirent); 374 if (!t) { 375 warn_no_space_for_csum(inode); 376 return; 377 } 378 379 t->det_checksum = ext4_dirent_csum(inode, dirent, 380 (void *)t - (void *)dirent); 381 } 382 383 int ext4_handle_dirty_dirent_node(handle_t *handle, 384 struct inode *inode, 385 struct buffer_head *bh) 386 { 387 ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data); 388 return ext4_handle_dirty_metadata(handle, inode, bh); 389 } 390 391 static struct dx_countlimit *get_dx_countlimit(struct inode *inode, 392 struct ext4_dir_entry *dirent, 393 int *offset) 394 { 395 struct ext4_dir_entry *dp; 396 struct dx_root_info *root; 397 int count_offset; 398 399 if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb)) 400 count_offset = 8; 401 else if (le16_to_cpu(dirent->rec_len) == 12) { 402 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12); 403 if (le16_to_cpu(dp->rec_len) != 404 EXT4_BLOCK_SIZE(inode->i_sb) - 12) 405 return NULL; 406 root = (struct dx_root_info *)(((void *)dp + 12)); 407 if (root->reserved_zero || 408 root->info_length != sizeof(struct dx_root_info)) 409 return NULL; 410 count_offset = 32; 411 } else 412 return NULL; 413 414 if (offset) 415 *offset = count_offset; 416 return (struct dx_countlimit *)(((void *)dirent) + count_offset); 417 } 418 419 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent, 420 int count_offset, int count, struct dx_tail *t) 421 { 422 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 423 struct ext4_inode_info *ei = EXT4_I(inode); 424 __u32 csum; 425 int size; 426 __u32 dummy_csum = 0; 427 int offset = offsetof(struct dx_tail, dt_checksum); 428 429 size = count_offset + (count * sizeof(struct dx_entry)); 430 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size); 431 csum = ext4_chksum(sbi, csum, (__u8 *)t, offset); 432 csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum)); 433 434 return cpu_to_le32(csum); 435 } 436 437 static int ext4_dx_csum_verify(struct inode *inode, 438 struct ext4_dir_entry *dirent) 439 { 440 struct dx_countlimit *c; 441 struct dx_tail *t; 442 int count_offset, limit, count; 443 444 if (!ext4_has_metadata_csum(inode->i_sb)) 445 return 1; 446 447 c = get_dx_countlimit(inode, dirent, &count_offset); 448 if (!c) { 449 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D."); 450 return 0; 451 } 452 limit = le16_to_cpu(c->limit); 453 count = le16_to_cpu(c->count); 454 if (count_offset + (limit * sizeof(struct dx_entry)) > 455 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) { 456 warn_no_space_for_csum(inode); 457 return 0; 458 } 459 t = (struct dx_tail *)(((struct dx_entry *)c) + limit); 460 461 if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset, 462 count, t)) 463 return 0; 464 return 1; 465 } 466 467 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent) 468 { 469 struct dx_countlimit *c; 470 struct dx_tail *t; 471 int count_offset, limit, count; 472 473 if (!ext4_has_metadata_csum(inode->i_sb)) 474 return; 475 476 c = get_dx_countlimit(inode, dirent, &count_offset); 477 if (!c) { 478 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D."); 479 return; 480 } 481 limit = le16_to_cpu(c->limit); 482 count = le16_to_cpu(c->count); 483 if (count_offset + (limit * sizeof(struct dx_entry)) > 484 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) { 485 warn_no_space_for_csum(inode); 486 return; 487 } 488 t = (struct dx_tail *)(((struct dx_entry *)c) + limit); 489 490 t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t); 491 } 492 493 static inline int ext4_handle_dirty_dx_node(handle_t *handle, 494 struct inode *inode, 495 struct buffer_head *bh) 496 { 497 ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data); 498 return ext4_handle_dirty_metadata(handle, inode, bh); 499 } 500 501 /* 502 * p is at least 6 bytes before the end of page 503 */ 504 static inline struct ext4_dir_entry_2 * 505 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize) 506 { 507 return (struct ext4_dir_entry_2 *)((char *)p + 508 ext4_rec_len_from_disk(p->rec_len, blocksize)); 509 } 510 511 /* 512 * Future: use high four bits of block for coalesce-on-delete flags 513 * Mask them off for now. 514 */ 515 516 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry) 517 { 518 return le32_to_cpu(entry->block) & 0x0fffffff; 519 } 520 521 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value) 522 { 523 entry->block = cpu_to_le32(value); 524 } 525 526 static inline unsigned dx_get_hash(struct dx_entry *entry) 527 { 528 return le32_to_cpu(entry->hash); 529 } 530 531 static inline void dx_set_hash(struct dx_entry *entry, unsigned value) 532 { 533 entry->hash = cpu_to_le32(value); 534 } 535 536 static inline unsigned dx_get_count(struct dx_entry *entries) 537 { 538 return le16_to_cpu(((struct dx_countlimit *) entries)->count); 539 } 540 541 static inline unsigned dx_get_limit(struct dx_entry *entries) 542 { 543 return le16_to_cpu(((struct dx_countlimit *) entries)->limit); 544 } 545 546 static inline void dx_set_count(struct dx_entry *entries, unsigned value) 547 { 548 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value); 549 } 550 551 static inline void dx_set_limit(struct dx_entry *entries, unsigned value) 552 { 553 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value); 554 } 555 556 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize) 557 { 558 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) - 559 EXT4_DIR_REC_LEN(2) - infosize; 560 561 if (ext4_has_metadata_csum(dir->i_sb)) 562 entry_space -= sizeof(struct dx_tail); 563 return entry_space / sizeof(struct dx_entry); 564 } 565 566 static inline unsigned dx_node_limit(struct inode *dir) 567 { 568 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0); 569 570 if (ext4_has_metadata_csum(dir->i_sb)) 571 entry_space -= sizeof(struct dx_tail); 572 return entry_space / sizeof(struct dx_entry); 573 } 574 575 /* 576 * Debug 577 */ 578 #ifdef DX_DEBUG 579 static void dx_show_index(char * label, struct dx_entry *entries) 580 { 581 int i, n = dx_get_count (entries); 582 printk(KERN_DEBUG "%s index", label); 583 for (i = 0; i < n; i++) { 584 printk(KERN_CONT " %x->%lu", 585 i ? dx_get_hash(entries + i) : 0, 586 (unsigned long)dx_get_block(entries + i)); 587 } 588 printk(KERN_CONT "\n"); 589 } 590 591 struct stats 592 { 593 unsigned names; 594 unsigned space; 595 unsigned bcount; 596 }; 597 598 static struct stats dx_show_leaf(struct inode *dir, 599 struct dx_hash_info *hinfo, 600 struct ext4_dir_entry_2 *de, 601 int size, int show_names) 602 { 603 unsigned names = 0, space = 0; 604 char *base = (char *) de; 605 struct dx_hash_info h = *hinfo; 606 607 printk("names: "); 608 while ((char *) de < base + size) 609 { 610 if (de->inode) 611 { 612 if (show_names) 613 { 614 #ifdef CONFIG_EXT4_FS_ENCRYPTION 615 int len; 616 char *name; 617 struct fscrypt_str fname_crypto_str = 618 FSTR_INIT(NULL, 0); 619 int res = 0; 620 621 name = de->name; 622 len = de->name_len; 623 if (ext4_encrypted_inode(dir)) 624 res = fscrypt_get_encryption_info(dir); 625 if (res) { 626 printk(KERN_WARNING "Error setting up" 627 " fname crypto: %d\n", res); 628 } 629 if (!fscrypt_has_encryption_key(dir)) { 630 /* Directory is not encrypted */ 631 ext4fs_dirhash(de->name, 632 de->name_len, &h); 633 printk("%*.s:(U)%x.%u ", len, 634 name, h.hash, 635 (unsigned) ((char *) de 636 - base)); 637 } else { 638 struct fscrypt_str de_name = 639 FSTR_INIT(name, len); 640 641 /* Directory is encrypted */ 642 res = fscrypt_fname_alloc_buffer( 643 dir, len, 644 &fname_crypto_str); 645 if (res) 646 printk(KERN_WARNING "Error " 647 "allocating crypto " 648 "buffer--skipping " 649 "crypto\n"); 650 res = fscrypt_fname_disk_to_usr(dir, 651 0, 0, &de_name, 652 &fname_crypto_str); 653 if (res) { 654 printk(KERN_WARNING "Error " 655 "converting filename " 656 "from disk to usr" 657 "\n"); 658 name = "??"; 659 len = 2; 660 } else { 661 name = fname_crypto_str.name; 662 len = fname_crypto_str.len; 663 } 664 ext4fs_dirhash(de->name, de->name_len, 665 &h); 666 printk("%*.s:(E)%x.%u ", len, name, 667 h.hash, (unsigned) ((char *) de 668 - base)); 669 fscrypt_fname_free_buffer( 670 &fname_crypto_str); 671 } 672 #else 673 int len = de->name_len; 674 char *name = de->name; 675 ext4fs_dirhash(de->name, de->name_len, &h); 676 printk("%*.s:%x.%u ", len, name, h.hash, 677 (unsigned) ((char *) de - base)); 678 #endif 679 } 680 space += EXT4_DIR_REC_LEN(de->name_len); 681 names++; 682 } 683 de = ext4_next_entry(de, size); 684 } 685 printk(KERN_CONT "(%i)\n", names); 686 return (struct stats) { names, space, 1 }; 687 } 688 689 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir, 690 struct dx_entry *entries, int levels) 691 { 692 unsigned blocksize = dir->i_sb->s_blocksize; 693 unsigned count = dx_get_count(entries), names = 0, space = 0, i; 694 unsigned bcount = 0; 695 struct buffer_head *bh; 696 printk("%i indexed blocks...\n", count); 697 for (i = 0; i < count; i++, entries++) 698 { 699 ext4_lblk_t block = dx_get_block(entries); 700 ext4_lblk_t hash = i ? dx_get_hash(entries): 0; 701 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash; 702 struct stats stats; 703 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range); 704 bh = ext4_bread(NULL,dir, block, 0); 705 if (!bh || IS_ERR(bh)) 706 continue; 707 stats = levels? 708 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1): 709 dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) 710 bh->b_data, blocksize, 0); 711 names += stats.names; 712 space += stats.space; 713 bcount += stats.bcount; 714 brelse(bh); 715 } 716 if (bcount) 717 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n", 718 levels ? "" : " ", names, space/bcount, 719 (space/bcount)*100/blocksize); 720 return (struct stats) { names, space, bcount}; 721 } 722 #endif /* DX_DEBUG */ 723 724 /* 725 * Probe for a directory leaf block to search. 726 * 727 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format 728 * error in the directory index, and the caller should fall back to 729 * searching the directory normally. The callers of dx_probe **MUST** 730 * check for this error code, and make sure it never gets reflected 731 * back to userspace. 732 */ 733 static struct dx_frame * 734 dx_probe(struct ext4_filename *fname, struct inode *dir, 735 struct dx_hash_info *hinfo, struct dx_frame *frame_in) 736 { 737 unsigned count, indirect; 738 struct dx_entry *at, *entries, *p, *q, *m; 739 struct dx_root *root; 740 struct dx_frame *frame = frame_in; 741 struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR); 742 u32 hash; 743 744 memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0])); 745 frame->bh = ext4_read_dirblock(dir, 0, INDEX); 746 if (IS_ERR(frame->bh)) 747 return (struct dx_frame *) frame->bh; 748 749 root = (struct dx_root *) frame->bh->b_data; 750 if (root->info.hash_version != DX_HASH_TEA && 751 root->info.hash_version != DX_HASH_HALF_MD4 && 752 root->info.hash_version != DX_HASH_LEGACY) { 753 ext4_warning_inode(dir, "Unrecognised inode hash code %u", 754 root->info.hash_version); 755 goto fail; 756 } 757 if (fname) 758 hinfo = &fname->hinfo; 759 hinfo->hash_version = root->info.hash_version; 760 if (hinfo->hash_version <= DX_HASH_TEA) 761 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; 762 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed; 763 if (fname && fname_name(fname)) 764 ext4fs_dirhash(fname_name(fname), fname_len(fname), hinfo); 765 hash = hinfo->hash; 766 767 if (root->info.unused_flags & 1) { 768 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x", 769 root->info.unused_flags); 770 goto fail; 771 } 772 773 indirect = root->info.indirect_levels; 774 if (indirect >= ext4_dir_htree_level(dir->i_sb)) { 775 ext4_warning(dir->i_sb, 776 "Directory (ino: %lu) htree depth %#06x exceed" 777 "supported value", dir->i_ino, 778 ext4_dir_htree_level(dir->i_sb)); 779 if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) { 780 ext4_warning(dir->i_sb, "Enable large directory " 781 "feature to access it"); 782 } 783 goto fail; 784 } 785 786 entries = (struct dx_entry *)(((char *)&root->info) + 787 root->info.info_length); 788 789 if (dx_get_limit(entries) != dx_root_limit(dir, 790 root->info.info_length)) { 791 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u", 792 dx_get_limit(entries), 793 dx_root_limit(dir, root->info.info_length)); 794 goto fail; 795 } 796 797 dxtrace(printk("Look up %x", hash)); 798 while (1) { 799 count = dx_get_count(entries); 800 if (!count || count > dx_get_limit(entries)) { 801 ext4_warning_inode(dir, 802 "dx entry: count %u beyond limit %u", 803 count, dx_get_limit(entries)); 804 goto fail; 805 } 806 807 p = entries + 1; 808 q = entries + count - 1; 809 while (p <= q) { 810 m = p + (q - p) / 2; 811 dxtrace(printk(KERN_CONT ".")); 812 if (dx_get_hash(m) > hash) 813 q = m - 1; 814 else 815 p = m + 1; 816 } 817 818 if (0) { // linear search cross check 819 unsigned n = count - 1; 820 at = entries; 821 while (n--) 822 { 823 dxtrace(printk(KERN_CONT ",")); 824 if (dx_get_hash(++at) > hash) 825 { 826 at--; 827 break; 828 } 829 } 830 assert (at == p - 1); 831 } 832 833 at = p - 1; 834 dxtrace(printk(KERN_CONT " %x->%u\n", 835 at == entries ? 0 : dx_get_hash(at), 836 dx_get_block(at))); 837 frame->entries = entries; 838 frame->at = at; 839 if (!indirect--) 840 return frame; 841 frame++; 842 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX); 843 if (IS_ERR(frame->bh)) { 844 ret_err = (struct dx_frame *) frame->bh; 845 frame->bh = NULL; 846 goto fail; 847 } 848 entries = ((struct dx_node *) frame->bh->b_data)->entries; 849 850 if (dx_get_limit(entries) != dx_node_limit(dir)) { 851 ext4_warning_inode(dir, 852 "dx entry: limit %u != node limit %u", 853 dx_get_limit(entries), dx_node_limit(dir)); 854 goto fail; 855 } 856 } 857 fail: 858 while (frame >= frame_in) { 859 brelse(frame->bh); 860 frame--; 861 } 862 863 if (ret_err == ERR_PTR(ERR_BAD_DX_DIR)) 864 ext4_warning_inode(dir, 865 "Corrupt directory, running e2fsck is recommended"); 866 return ret_err; 867 } 868 869 static void dx_release(struct dx_frame *frames) 870 { 871 struct dx_root_info *info; 872 int i; 873 874 if (frames[0].bh == NULL) 875 return; 876 877 info = &((struct dx_root *)frames[0].bh->b_data)->info; 878 for (i = 0; i <= info->indirect_levels; i++) { 879 if (frames[i].bh == NULL) 880 break; 881 brelse(frames[i].bh); 882 frames[i].bh = NULL; 883 } 884 } 885 886 /* 887 * This function increments the frame pointer to search the next leaf 888 * block, and reads in the necessary intervening nodes if the search 889 * should be necessary. Whether or not the search is necessary is 890 * controlled by the hash parameter. If the hash value is even, then 891 * the search is only continued if the next block starts with that 892 * hash value. This is used if we are searching for a specific file. 893 * 894 * If the hash value is HASH_NB_ALWAYS, then always go to the next block. 895 * 896 * This function returns 1 if the caller should continue to search, 897 * or 0 if it should not. If there is an error reading one of the 898 * index blocks, it will a negative error code. 899 * 900 * If start_hash is non-null, it will be filled in with the starting 901 * hash of the next page. 902 */ 903 static int ext4_htree_next_block(struct inode *dir, __u32 hash, 904 struct dx_frame *frame, 905 struct dx_frame *frames, 906 __u32 *start_hash) 907 { 908 struct dx_frame *p; 909 struct buffer_head *bh; 910 int num_frames = 0; 911 __u32 bhash; 912 913 p = frame; 914 /* 915 * Find the next leaf page by incrementing the frame pointer. 916 * If we run out of entries in the interior node, loop around and 917 * increment pointer in the parent node. When we break out of 918 * this loop, num_frames indicates the number of interior 919 * nodes need to be read. 920 */ 921 while (1) { 922 if (++(p->at) < p->entries + dx_get_count(p->entries)) 923 break; 924 if (p == frames) 925 return 0; 926 num_frames++; 927 p--; 928 } 929 930 /* 931 * If the hash is 1, then continue only if the next page has a 932 * continuation hash of any value. This is used for readdir 933 * handling. Otherwise, check to see if the hash matches the 934 * desired contiuation hash. If it doesn't, return since 935 * there's no point to read in the successive index pages. 936 */ 937 bhash = dx_get_hash(p->at); 938 if (start_hash) 939 *start_hash = bhash; 940 if ((hash & 1) == 0) { 941 if ((bhash & ~1) != hash) 942 return 0; 943 } 944 /* 945 * If the hash is HASH_NB_ALWAYS, we always go to the next 946 * block so no check is necessary 947 */ 948 while (num_frames--) { 949 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX); 950 if (IS_ERR(bh)) 951 return PTR_ERR(bh); 952 p++; 953 brelse(p->bh); 954 p->bh = bh; 955 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries; 956 } 957 return 1; 958 } 959 960 961 /* 962 * This function fills a red-black tree with information from a 963 * directory block. It returns the number directory entries loaded 964 * into the tree. If there is an error it is returned in err. 965 */ 966 static int htree_dirblock_to_tree(struct file *dir_file, 967 struct inode *dir, ext4_lblk_t block, 968 struct dx_hash_info *hinfo, 969 __u32 start_hash, __u32 start_minor_hash) 970 { 971 struct buffer_head *bh; 972 struct ext4_dir_entry_2 *de, *top; 973 int err = 0, count = 0; 974 struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str; 975 976 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n", 977 (unsigned long)block)); 978 bh = ext4_read_dirblock(dir, block, DIRENT); 979 if (IS_ERR(bh)) 980 return PTR_ERR(bh); 981 982 de = (struct ext4_dir_entry_2 *) bh->b_data; 983 top = (struct ext4_dir_entry_2 *) ((char *) de + 984 dir->i_sb->s_blocksize - 985 EXT4_DIR_REC_LEN(0)); 986 #ifdef CONFIG_EXT4_FS_ENCRYPTION 987 /* Check if the directory is encrypted */ 988 if (ext4_encrypted_inode(dir)) { 989 err = fscrypt_get_encryption_info(dir); 990 if (err < 0) { 991 brelse(bh); 992 return err; 993 } 994 err = fscrypt_fname_alloc_buffer(dir, EXT4_NAME_LEN, 995 &fname_crypto_str); 996 if (err < 0) { 997 brelse(bh); 998 return err; 999 } 1000 } 1001 #endif 1002 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) { 1003 if (ext4_check_dir_entry(dir, NULL, de, bh, 1004 bh->b_data, bh->b_size, 1005 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb)) 1006 + ((char *)de - bh->b_data))) { 1007 /* silently ignore the rest of the block */ 1008 break; 1009 } 1010 ext4fs_dirhash(de->name, de->name_len, hinfo); 1011 if ((hinfo->hash < start_hash) || 1012 ((hinfo->hash == start_hash) && 1013 (hinfo->minor_hash < start_minor_hash))) 1014 continue; 1015 if (de->inode == 0) 1016 continue; 1017 if (!ext4_encrypted_inode(dir)) { 1018 tmp_str.name = de->name; 1019 tmp_str.len = de->name_len; 1020 err = ext4_htree_store_dirent(dir_file, 1021 hinfo->hash, hinfo->minor_hash, de, 1022 &tmp_str); 1023 } else { 1024 int save_len = fname_crypto_str.len; 1025 struct fscrypt_str de_name = FSTR_INIT(de->name, 1026 de->name_len); 1027 1028 /* Directory is encrypted */ 1029 err = fscrypt_fname_disk_to_usr(dir, hinfo->hash, 1030 hinfo->minor_hash, &de_name, 1031 &fname_crypto_str); 1032 if (err) { 1033 count = err; 1034 goto errout; 1035 } 1036 err = ext4_htree_store_dirent(dir_file, 1037 hinfo->hash, hinfo->minor_hash, de, 1038 &fname_crypto_str); 1039 fname_crypto_str.len = save_len; 1040 } 1041 if (err != 0) { 1042 count = err; 1043 goto errout; 1044 } 1045 count++; 1046 } 1047 errout: 1048 brelse(bh); 1049 #ifdef CONFIG_EXT4_FS_ENCRYPTION 1050 fscrypt_fname_free_buffer(&fname_crypto_str); 1051 #endif 1052 return count; 1053 } 1054 1055 1056 /* 1057 * This function fills a red-black tree with information from a 1058 * directory. We start scanning the directory in hash order, starting 1059 * at start_hash and start_minor_hash. 1060 * 1061 * This function returns the number of entries inserted into the tree, 1062 * or a negative error code. 1063 */ 1064 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash, 1065 __u32 start_minor_hash, __u32 *next_hash) 1066 { 1067 struct dx_hash_info hinfo; 1068 struct ext4_dir_entry_2 *de; 1069 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 1070 struct inode *dir; 1071 ext4_lblk_t block; 1072 int count = 0; 1073 int ret, err; 1074 __u32 hashval; 1075 struct fscrypt_str tmp_str; 1076 1077 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n", 1078 start_hash, start_minor_hash)); 1079 dir = file_inode(dir_file); 1080 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) { 1081 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version; 1082 if (hinfo.hash_version <= DX_HASH_TEA) 1083 hinfo.hash_version += 1084 EXT4_SB(dir->i_sb)->s_hash_unsigned; 1085 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; 1086 if (ext4_has_inline_data(dir)) { 1087 int has_inline_data = 1; 1088 count = htree_inlinedir_to_tree(dir_file, dir, 0, 1089 &hinfo, start_hash, 1090 start_minor_hash, 1091 &has_inline_data); 1092 if (has_inline_data) { 1093 *next_hash = ~0; 1094 return count; 1095 } 1096 } 1097 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo, 1098 start_hash, start_minor_hash); 1099 *next_hash = ~0; 1100 return count; 1101 } 1102 hinfo.hash = start_hash; 1103 hinfo.minor_hash = 0; 1104 frame = dx_probe(NULL, dir, &hinfo, frames); 1105 if (IS_ERR(frame)) 1106 return PTR_ERR(frame); 1107 1108 /* Add '.' and '..' from the htree header */ 1109 if (!start_hash && !start_minor_hash) { 1110 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; 1111 tmp_str.name = de->name; 1112 tmp_str.len = de->name_len; 1113 err = ext4_htree_store_dirent(dir_file, 0, 0, 1114 de, &tmp_str); 1115 if (err != 0) 1116 goto errout; 1117 count++; 1118 } 1119 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) { 1120 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; 1121 de = ext4_next_entry(de, dir->i_sb->s_blocksize); 1122 tmp_str.name = de->name; 1123 tmp_str.len = de->name_len; 1124 err = ext4_htree_store_dirent(dir_file, 2, 0, 1125 de, &tmp_str); 1126 if (err != 0) 1127 goto errout; 1128 count++; 1129 } 1130 1131 while (1) { 1132 if (fatal_signal_pending(current)) { 1133 err = -ERESTARTSYS; 1134 goto errout; 1135 } 1136 cond_resched(); 1137 block = dx_get_block(frame->at); 1138 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo, 1139 start_hash, start_minor_hash); 1140 if (ret < 0) { 1141 err = ret; 1142 goto errout; 1143 } 1144 count += ret; 1145 hashval = ~0; 1146 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS, 1147 frame, frames, &hashval); 1148 *next_hash = hashval; 1149 if (ret < 0) { 1150 err = ret; 1151 goto errout; 1152 } 1153 /* 1154 * Stop if: (a) there are no more entries, or 1155 * (b) we have inserted at least one entry and the 1156 * next hash value is not a continuation 1157 */ 1158 if ((ret == 0) || 1159 (count && ((hashval & 1) == 0))) 1160 break; 1161 } 1162 dx_release(frames); 1163 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, " 1164 "next hash: %x\n", count, *next_hash)); 1165 return count; 1166 errout: 1167 dx_release(frames); 1168 return (err); 1169 } 1170 1171 static inline int search_dirblock(struct buffer_head *bh, 1172 struct inode *dir, 1173 struct ext4_filename *fname, 1174 unsigned int offset, 1175 struct ext4_dir_entry_2 **res_dir) 1176 { 1177 return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir, 1178 fname, offset, res_dir); 1179 } 1180 1181 /* 1182 * Directory block splitting, compacting 1183 */ 1184 1185 /* 1186 * Create map of hash values, offsets, and sizes, stored at end of block. 1187 * Returns number of entries mapped. 1188 */ 1189 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de, 1190 unsigned blocksize, struct dx_hash_info *hinfo, 1191 struct dx_map_entry *map_tail) 1192 { 1193 int count = 0; 1194 char *base = (char *) de; 1195 struct dx_hash_info h = *hinfo; 1196 1197 while ((char *) de < base + blocksize) { 1198 if (de->name_len && de->inode) { 1199 ext4fs_dirhash(de->name, de->name_len, &h); 1200 map_tail--; 1201 map_tail->hash = h.hash; 1202 map_tail->offs = ((char *) de - base)>>2; 1203 map_tail->size = le16_to_cpu(de->rec_len); 1204 count++; 1205 cond_resched(); 1206 } 1207 /* XXX: do we need to check rec_len == 0 case? -Chris */ 1208 de = ext4_next_entry(de, blocksize); 1209 } 1210 return count; 1211 } 1212 1213 /* Sort map by hash value */ 1214 static void dx_sort_map (struct dx_map_entry *map, unsigned count) 1215 { 1216 struct dx_map_entry *p, *q, *top = map + count - 1; 1217 int more; 1218 /* Combsort until bubble sort doesn't suck */ 1219 while (count > 2) { 1220 count = count*10/13; 1221 if (count - 9 < 2) /* 9, 10 -> 11 */ 1222 count = 11; 1223 for (p = top, q = p - count; q >= map; p--, q--) 1224 if (p->hash < q->hash) 1225 swap(*p, *q); 1226 } 1227 /* Garden variety bubble sort */ 1228 do { 1229 more = 0; 1230 q = top; 1231 while (q-- > map) { 1232 if (q[1].hash >= q[0].hash) 1233 continue; 1234 swap(*(q+1), *q); 1235 more = 1; 1236 } 1237 } while(more); 1238 } 1239 1240 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block) 1241 { 1242 struct dx_entry *entries = frame->entries; 1243 struct dx_entry *old = frame->at, *new = old + 1; 1244 int count = dx_get_count(entries); 1245 1246 assert(count < dx_get_limit(entries)); 1247 assert(old < entries + count); 1248 memmove(new + 1, new, (char *)(entries + count) - (char *)(new)); 1249 dx_set_hash(new, hash); 1250 dx_set_block(new, block); 1251 dx_set_count(entries, count + 1); 1252 } 1253 1254 /* 1255 * Test whether a directory entry matches the filename being searched for. 1256 * 1257 * Return: %true if the directory entry matches, otherwise %false. 1258 */ 1259 static inline bool ext4_match(const struct ext4_filename *fname, 1260 const struct ext4_dir_entry_2 *de) 1261 { 1262 struct fscrypt_name f; 1263 1264 if (!de->inode) 1265 return false; 1266 1267 f.usr_fname = fname->usr_fname; 1268 f.disk_name = fname->disk_name; 1269 #ifdef CONFIG_EXT4_FS_ENCRYPTION 1270 f.crypto_buf = fname->crypto_buf; 1271 #endif 1272 return fscrypt_match_name(&f, de->name, de->name_len); 1273 } 1274 1275 /* 1276 * Returns 0 if not found, -1 on failure, and 1 on success 1277 */ 1278 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size, 1279 struct inode *dir, struct ext4_filename *fname, 1280 unsigned int offset, struct ext4_dir_entry_2 **res_dir) 1281 { 1282 struct ext4_dir_entry_2 * de; 1283 char * dlimit; 1284 int de_len; 1285 1286 de = (struct ext4_dir_entry_2 *)search_buf; 1287 dlimit = search_buf + buf_size; 1288 while ((char *) de < dlimit) { 1289 /* this code is executed quadratically often */ 1290 /* do minimal checking `by hand' */ 1291 if ((char *) de + de->name_len <= dlimit && 1292 ext4_match(fname, de)) { 1293 /* found a match - just to be sure, do 1294 * a full check */ 1295 if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data, 1296 bh->b_size, offset)) 1297 return -1; 1298 *res_dir = de; 1299 return 1; 1300 } 1301 /* prevent looping on a bad block */ 1302 de_len = ext4_rec_len_from_disk(de->rec_len, 1303 dir->i_sb->s_blocksize); 1304 if (de_len <= 0) 1305 return -1; 1306 offset += de_len; 1307 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len); 1308 } 1309 return 0; 1310 } 1311 1312 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block, 1313 struct ext4_dir_entry *de) 1314 { 1315 struct super_block *sb = dir->i_sb; 1316 1317 if (!is_dx(dir)) 1318 return 0; 1319 if (block == 0) 1320 return 1; 1321 if (de->inode == 0 && 1322 ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) == 1323 sb->s_blocksize) 1324 return 1; 1325 return 0; 1326 } 1327 1328 /* 1329 * ext4_find_entry() 1330 * 1331 * finds an entry in the specified directory with the wanted name. It 1332 * returns the cache buffer in which the entry was found, and the entry 1333 * itself (as a parameter - res_dir). It does NOT read the inode of the 1334 * entry - you'll have to do that yourself if you want to. 1335 * 1336 * The returned buffer_head has ->b_count elevated. The caller is expected 1337 * to brelse() it when appropriate. 1338 */ 1339 static struct buffer_head * ext4_find_entry (struct inode *dir, 1340 const struct qstr *d_name, 1341 struct ext4_dir_entry_2 **res_dir, 1342 int *inlined) 1343 { 1344 struct super_block *sb; 1345 struct buffer_head *bh_use[NAMEI_RA_SIZE]; 1346 struct buffer_head *bh, *ret = NULL; 1347 ext4_lblk_t start, block; 1348 const u8 *name = d_name->name; 1349 size_t ra_max = 0; /* Number of bh's in the readahead 1350 buffer, bh_use[] */ 1351 size_t ra_ptr = 0; /* Current index into readahead 1352 buffer */ 1353 ext4_lblk_t nblocks; 1354 int i, namelen, retval; 1355 struct ext4_filename fname; 1356 1357 *res_dir = NULL; 1358 sb = dir->i_sb; 1359 namelen = d_name->len; 1360 if (namelen > EXT4_NAME_LEN) 1361 return NULL; 1362 1363 retval = ext4_fname_setup_filename(dir, d_name, 1, &fname); 1364 if (retval == -ENOENT) 1365 return NULL; 1366 if (retval) 1367 return ERR_PTR(retval); 1368 1369 if (ext4_has_inline_data(dir)) { 1370 int has_inline_data = 1; 1371 ret = ext4_find_inline_entry(dir, &fname, res_dir, 1372 &has_inline_data); 1373 if (has_inline_data) { 1374 if (inlined) 1375 *inlined = 1; 1376 goto cleanup_and_exit; 1377 } 1378 } 1379 1380 if ((namelen <= 2) && (name[0] == '.') && 1381 (name[1] == '.' || name[1] == '\0')) { 1382 /* 1383 * "." or ".." will only be in the first block 1384 * NFS may look up ".."; "." should be handled by the VFS 1385 */ 1386 block = start = 0; 1387 nblocks = 1; 1388 goto restart; 1389 } 1390 if (is_dx(dir)) { 1391 ret = ext4_dx_find_entry(dir, &fname, res_dir); 1392 /* 1393 * On success, or if the error was file not found, 1394 * return. Otherwise, fall back to doing a search the 1395 * old fashioned way. 1396 */ 1397 if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR) 1398 goto cleanup_and_exit; 1399 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, " 1400 "falling back\n")); 1401 } 1402 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); 1403 if (!nblocks) { 1404 ret = NULL; 1405 goto cleanup_and_exit; 1406 } 1407 start = EXT4_I(dir)->i_dir_start_lookup; 1408 if (start >= nblocks) 1409 start = 0; 1410 block = start; 1411 restart: 1412 do { 1413 /* 1414 * We deal with the read-ahead logic here. 1415 */ 1416 if (ra_ptr >= ra_max) { 1417 /* Refill the readahead buffer */ 1418 ra_ptr = 0; 1419 if (block < start) 1420 ra_max = start - block; 1421 else 1422 ra_max = nblocks - block; 1423 ra_max = min(ra_max, ARRAY_SIZE(bh_use)); 1424 retval = ext4_bread_batch(dir, block, ra_max, 1425 false /* wait */, bh_use); 1426 if (retval) { 1427 ret = ERR_PTR(retval); 1428 ra_max = 0; 1429 goto cleanup_and_exit; 1430 } 1431 } 1432 if ((bh = bh_use[ra_ptr++]) == NULL) 1433 goto next; 1434 wait_on_buffer(bh); 1435 if (!buffer_uptodate(bh)) { 1436 EXT4_ERROR_INODE(dir, "reading directory lblock %lu", 1437 (unsigned long) block); 1438 brelse(bh); 1439 ret = ERR_PTR(-EIO); 1440 goto cleanup_and_exit; 1441 } 1442 if (!buffer_verified(bh) && 1443 !is_dx_internal_node(dir, block, 1444 (struct ext4_dir_entry *)bh->b_data) && 1445 !ext4_dirent_csum_verify(dir, 1446 (struct ext4_dir_entry *)bh->b_data)) { 1447 EXT4_ERROR_INODE(dir, "checksumming directory " 1448 "block %lu", (unsigned long)block); 1449 brelse(bh); 1450 ret = ERR_PTR(-EFSBADCRC); 1451 goto cleanup_and_exit; 1452 } 1453 set_buffer_verified(bh); 1454 i = search_dirblock(bh, dir, &fname, 1455 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir); 1456 if (i == 1) { 1457 EXT4_I(dir)->i_dir_start_lookup = block; 1458 ret = bh; 1459 goto cleanup_and_exit; 1460 } else { 1461 brelse(bh); 1462 if (i < 0) 1463 goto cleanup_and_exit; 1464 } 1465 next: 1466 if (++block >= nblocks) 1467 block = 0; 1468 } while (block != start); 1469 1470 /* 1471 * If the directory has grown while we were searching, then 1472 * search the last part of the directory before giving up. 1473 */ 1474 block = nblocks; 1475 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); 1476 if (block < nblocks) { 1477 start = 0; 1478 goto restart; 1479 } 1480 1481 cleanup_and_exit: 1482 /* Clean up the read-ahead blocks */ 1483 for (; ra_ptr < ra_max; ra_ptr++) 1484 brelse(bh_use[ra_ptr]); 1485 ext4_fname_free_filename(&fname); 1486 return ret; 1487 } 1488 1489 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, 1490 struct ext4_filename *fname, 1491 struct ext4_dir_entry_2 **res_dir) 1492 { 1493 struct super_block * sb = dir->i_sb; 1494 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 1495 struct buffer_head *bh; 1496 ext4_lblk_t block; 1497 int retval; 1498 1499 #ifdef CONFIG_EXT4_FS_ENCRYPTION 1500 *res_dir = NULL; 1501 #endif 1502 frame = dx_probe(fname, dir, NULL, frames); 1503 if (IS_ERR(frame)) 1504 return (struct buffer_head *) frame; 1505 do { 1506 block = dx_get_block(frame->at); 1507 bh = ext4_read_dirblock(dir, block, DIRENT); 1508 if (IS_ERR(bh)) 1509 goto errout; 1510 1511 retval = search_dirblock(bh, dir, fname, 1512 block << EXT4_BLOCK_SIZE_BITS(sb), 1513 res_dir); 1514 if (retval == 1) 1515 goto success; 1516 brelse(bh); 1517 if (retval == -1) { 1518 bh = ERR_PTR(ERR_BAD_DX_DIR); 1519 goto errout; 1520 } 1521 1522 /* Check to see if we should continue to search */ 1523 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame, 1524 frames, NULL); 1525 if (retval < 0) { 1526 ext4_warning_inode(dir, 1527 "error %d reading directory index block", 1528 retval); 1529 bh = ERR_PTR(retval); 1530 goto errout; 1531 } 1532 } while (retval == 1); 1533 1534 bh = NULL; 1535 errout: 1536 dxtrace(printk(KERN_DEBUG "%s not found\n", fname->usr_fname->name)); 1537 success: 1538 dx_release(frames); 1539 return bh; 1540 } 1541 1542 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 1543 { 1544 struct inode *inode; 1545 struct ext4_dir_entry_2 *de; 1546 struct buffer_head *bh; 1547 int err; 1548 1549 err = fscrypt_prepare_lookup(dir, dentry, flags); 1550 if (err) 1551 return ERR_PTR(err); 1552 1553 if (dentry->d_name.len > EXT4_NAME_LEN) 1554 return ERR_PTR(-ENAMETOOLONG); 1555 1556 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); 1557 if (IS_ERR(bh)) 1558 return (struct dentry *) bh; 1559 inode = NULL; 1560 if (bh) { 1561 __u32 ino = le32_to_cpu(de->inode); 1562 brelse(bh); 1563 if (!ext4_valid_inum(dir->i_sb, ino)) { 1564 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino); 1565 return ERR_PTR(-EFSCORRUPTED); 1566 } 1567 if (unlikely(ino == dir->i_ino)) { 1568 EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir", 1569 dentry); 1570 return ERR_PTR(-EFSCORRUPTED); 1571 } 1572 inode = ext4_iget_normal(dir->i_sb, ino); 1573 if (inode == ERR_PTR(-ESTALE)) { 1574 EXT4_ERROR_INODE(dir, 1575 "deleted inode referenced: %u", 1576 ino); 1577 return ERR_PTR(-EFSCORRUPTED); 1578 } 1579 if (!IS_ERR(inode) && ext4_encrypted_inode(dir) && 1580 (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) && 1581 !fscrypt_has_permitted_context(dir, inode)) { 1582 ext4_warning(inode->i_sb, 1583 "Inconsistent encryption contexts: %lu/%lu", 1584 dir->i_ino, inode->i_ino); 1585 iput(inode); 1586 return ERR_PTR(-EPERM); 1587 } 1588 } 1589 return d_splice_alias(inode, dentry); 1590 } 1591 1592 1593 struct dentry *ext4_get_parent(struct dentry *child) 1594 { 1595 __u32 ino; 1596 static const struct qstr dotdot = QSTR_INIT("..", 2); 1597 struct ext4_dir_entry_2 * de; 1598 struct buffer_head *bh; 1599 1600 bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL); 1601 if (IS_ERR(bh)) 1602 return (struct dentry *) bh; 1603 if (!bh) 1604 return ERR_PTR(-ENOENT); 1605 ino = le32_to_cpu(de->inode); 1606 brelse(bh); 1607 1608 if (!ext4_valid_inum(child->d_sb, ino)) { 1609 EXT4_ERROR_INODE(d_inode(child), 1610 "bad parent inode number: %u", ino); 1611 return ERR_PTR(-EFSCORRUPTED); 1612 } 1613 1614 return d_obtain_alias(ext4_iget_normal(child->d_sb, ino)); 1615 } 1616 1617 /* 1618 * Move count entries from end of map between two memory locations. 1619 * Returns pointer to last entry moved. 1620 */ 1621 static struct ext4_dir_entry_2 * 1622 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count, 1623 unsigned blocksize) 1624 { 1625 unsigned rec_len = 0; 1626 1627 while (count--) { 1628 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) 1629 (from + (map->offs<<2)); 1630 rec_len = EXT4_DIR_REC_LEN(de->name_len); 1631 memcpy (to, de, rec_len); 1632 ((struct ext4_dir_entry_2 *) to)->rec_len = 1633 ext4_rec_len_to_disk(rec_len, blocksize); 1634 de->inode = 0; 1635 map++; 1636 to += rec_len; 1637 } 1638 return (struct ext4_dir_entry_2 *) (to - rec_len); 1639 } 1640 1641 /* 1642 * Compact each dir entry in the range to the minimal rec_len. 1643 * Returns pointer to last entry in range. 1644 */ 1645 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize) 1646 { 1647 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base; 1648 unsigned rec_len = 0; 1649 1650 prev = to = de; 1651 while ((char*)de < base + blocksize) { 1652 next = ext4_next_entry(de, blocksize); 1653 if (de->inode && de->name_len) { 1654 rec_len = EXT4_DIR_REC_LEN(de->name_len); 1655 if (de > to) 1656 memmove(to, de, rec_len); 1657 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize); 1658 prev = to; 1659 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len); 1660 } 1661 de = next; 1662 } 1663 return prev; 1664 } 1665 1666 /* 1667 * Split a full leaf block to make room for a new dir entry. 1668 * Allocate a new block, and move entries so that they are approx. equally full. 1669 * Returns pointer to de in block into which the new entry will be inserted. 1670 */ 1671 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir, 1672 struct buffer_head **bh,struct dx_frame *frame, 1673 struct dx_hash_info *hinfo) 1674 { 1675 unsigned blocksize = dir->i_sb->s_blocksize; 1676 unsigned count, continued; 1677 struct buffer_head *bh2; 1678 ext4_lblk_t newblock; 1679 u32 hash2; 1680 struct dx_map_entry *map; 1681 char *data1 = (*bh)->b_data, *data2; 1682 unsigned split, move, size; 1683 struct ext4_dir_entry_2 *de = NULL, *de2; 1684 struct ext4_dir_entry_tail *t; 1685 int csum_size = 0; 1686 int err = 0, i; 1687 1688 if (ext4_has_metadata_csum(dir->i_sb)) 1689 csum_size = sizeof(struct ext4_dir_entry_tail); 1690 1691 bh2 = ext4_append(handle, dir, &newblock); 1692 if (IS_ERR(bh2)) { 1693 brelse(*bh); 1694 *bh = NULL; 1695 return (struct ext4_dir_entry_2 *) bh2; 1696 } 1697 1698 BUFFER_TRACE(*bh, "get_write_access"); 1699 err = ext4_journal_get_write_access(handle, *bh); 1700 if (err) 1701 goto journal_error; 1702 1703 BUFFER_TRACE(frame->bh, "get_write_access"); 1704 err = ext4_journal_get_write_access(handle, frame->bh); 1705 if (err) 1706 goto journal_error; 1707 1708 data2 = bh2->b_data; 1709 1710 /* create map in the end of data2 block */ 1711 map = (struct dx_map_entry *) (data2 + blocksize); 1712 count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1, 1713 blocksize, hinfo, map); 1714 map -= count; 1715 dx_sort_map(map, count); 1716 /* Split the existing block in the middle, size-wise */ 1717 size = 0; 1718 move = 0; 1719 for (i = count-1; i >= 0; i--) { 1720 /* is more than half of this entry in 2nd half of the block? */ 1721 if (size + map[i].size/2 > blocksize/2) 1722 break; 1723 size += map[i].size; 1724 move++; 1725 } 1726 /* map index at which we will split */ 1727 split = count - move; 1728 hash2 = map[split].hash; 1729 continued = hash2 == map[split - 1].hash; 1730 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n", 1731 (unsigned long)dx_get_block(frame->at), 1732 hash2, split, count-split)); 1733 1734 /* Fancy dance to stay within two buffers */ 1735 de2 = dx_move_dirents(data1, data2, map + split, count - split, 1736 blocksize); 1737 de = dx_pack_dirents(data1, blocksize); 1738 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) - 1739 (char *) de, 1740 blocksize); 1741 de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) - 1742 (char *) de2, 1743 blocksize); 1744 if (csum_size) { 1745 t = EXT4_DIRENT_TAIL(data2, blocksize); 1746 initialize_dirent_tail(t, blocksize); 1747 1748 t = EXT4_DIRENT_TAIL(data1, blocksize); 1749 initialize_dirent_tail(t, blocksize); 1750 } 1751 1752 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1, 1753 blocksize, 1)); 1754 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2, 1755 blocksize, 1)); 1756 1757 /* Which block gets the new entry? */ 1758 if (hinfo->hash >= hash2) { 1759 swap(*bh, bh2); 1760 de = de2; 1761 } 1762 dx_insert_block(frame, hash2 + continued, newblock); 1763 err = ext4_handle_dirty_dirent_node(handle, dir, bh2); 1764 if (err) 1765 goto journal_error; 1766 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 1767 if (err) 1768 goto journal_error; 1769 brelse(bh2); 1770 dxtrace(dx_show_index("frame", frame->entries)); 1771 return de; 1772 1773 journal_error: 1774 brelse(*bh); 1775 brelse(bh2); 1776 *bh = NULL; 1777 ext4_std_error(dir->i_sb, err); 1778 return ERR_PTR(err); 1779 } 1780 1781 int ext4_find_dest_de(struct inode *dir, struct inode *inode, 1782 struct buffer_head *bh, 1783 void *buf, int buf_size, 1784 struct ext4_filename *fname, 1785 struct ext4_dir_entry_2 **dest_de) 1786 { 1787 struct ext4_dir_entry_2 *de; 1788 unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname)); 1789 int nlen, rlen; 1790 unsigned int offset = 0; 1791 char *top; 1792 1793 de = (struct ext4_dir_entry_2 *)buf; 1794 top = buf + buf_size - reclen; 1795 while ((char *) de <= top) { 1796 if (ext4_check_dir_entry(dir, NULL, de, bh, 1797 buf, buf_size, offset)) 1798 return -EFSCORRUPTED; 1799 if (ext4_match(fname, de)) 1800 return -EEXIST; 1801 nlen = EXT4_DIR_REC_LEN(de->name_len); 1802 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 1803 if ((de->inode ? rlen - nlen : rlen) >= reclen) 1804 break; 1805 de = (struct ext4_dir_entry_2 *)((char *)de + rlen); 1806 offset += rlen; 1807 } 1808 if ((char *) de > top) 1809 return -ENOSPC; 1810 1811 *dest_de = de; 1812 return 0; 1813 } 1814 1815 void ext4_insert_dentry(struct inode *inode, 1816 struct ext4_dir_entry_2 *de, 1817 int buf_size, 1818 struct ext4_filename *fname) 1819 { 1820 1821 int nlen, rlen; 1822 1823 nlen = EXT4_DIR_REC_LEN(de->name_len); 1824 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 1825 if (de->inode) { 1826 struct ext4_dir_entry_2 *de1 = 1827 (struct ext4_dir_entry_2 *)((char *)de + nlen); 1828 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size); 1829 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size); 1830 de = de1; 1831 } 1832 de->file_type = EXT4_FT_UNKNOWN; 1833 de->inode = cpu_to_le32(inode->i_ino); 1834 ext4_set_de_type(inode->i_sb, de, inode->i_mode); 1835 de->name_len = fname_len(fname); 1836 memcpy(de->name, fname_name(fname), fname_len(fname)); 1837 } 1838 1839 /* 1840 * Add a new entry into a directory (leaf) block. If de is non-NULL, 1841 * it points to a directory entry which is guaranteed to be large 1842 * enough for new directory entry. If de is NULL, then 1843 * add_dirent_to_buf will attempt search the directory block for 1844 * space. It will return -ENOSPC if no space is available, and -EIO 1845 * and -EEXIST if directory entry already exists. 1846 */ 1847 static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname, 1848 struct inode *dir, 1849 struct inode *inode, struct ext4_dir_entry_2 *de, 1850 struct buffer_head *bh) 1851 { 1852 unsigned int blocksize = dir->i_sb->s_blocksize; 1853 int csum_size = 0; 1854 int err; 1855 1856 if (ext4_has_metadata_csum(inode->i_sb)) 1857 csum_size = sizeof(struct ext4_dir_entry_tail); 1858 1859 if (!de) { 1860 err = ext4_find_dest_de(dir, inode, bh, bh->b_data, 1861 blocksize - csum_size, fname, &de); 1862 if (err) 1863 return err; 1864 } 1865 BUFFER_TRACE(bh, "get_write_access"); 1866 err = ext4_journal_get_write_access(handle, bh); 1867 if (err) { 1868 ext4_std_error(dir->i_sb, err); 1869 return err; 1870 } 1871 1872 /* By now the buffer is marked for journaling */ 1873 ext4_insert_dentry(inode, de, blocksize, fname); 1874 1875 /* 1876 * XXX shouldn't update any times until successful 1877 * completion of syscall, but too many callers depend 1878 * on this. 1879 * 1880 * XXX similarly, too many callers depend on 1881 * ext4_new_inode() setting the times, but error 1882 * recovery deletes the inode, so the worst that can 1883 * happen is that the times are slightly out of date 1884 * and/or different from the directory change time. 1885 */ 1886 dir->i_mtime = dir->i_ctime = current_time(dir); 1887 ext4_update_dx_flag(dir); 1888 inode_inc_iversion(dir); 1889 ext4_mark_inode_dirty(handle, dir); 1890 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); 1891 err = ext4_handle_dirty_dirent_node(handle, dir, bh); 1892 if (err) 1893 ext4_std_error(dir->i_sb, err); 1894 return 0; 1895 } 1896 1897 /* 1898 * This converts a one block unindexed directory to a 3 block indexed 1899 * directory, and adds the dentry to the indexed directory. 1900 */ 1901 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname, 1902 struct inode *dir, 1903 struct inode *inode, struct buffer_head *bh) 1904 { 1905 struct buffer_head *bh2; 1906 struct dx_root *root; 1907 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 1908 struct dx_entry *entries; 1909 struct ext4_dir_entry_2 *de, *de2; 1910 struct ext4_dir_entry_tail *t; 1911 char *data1, *top; 1912 unsigned len; 1913 int retval; 1914 unsigned blocksize; 1915 ext4_lblk_t block; 1916 struct fake_dirent *fde; 1917 int csum_size = 0; 1918 1919 if (ext4_has_metadata_csum(inode->i_sb)) 1920 csum_size = sizeof(struct ext4_dir_entry_tail); 1921 1922 blocksize = dir->i_sb->s_blocksize; 1923 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino)); 1924 BUFFER_TRACE(bh, "get_write_access"); 1925 retval = ext4_journal_get_write_access(handle, bh); 1926 if (retval) { 1927 ext4_std_error(dir->i_sb, retval); 1928 brelse(bh); 1929 return retval; 1930 } 1931 root = (struct dx_root *) bh->b_data; 1932 1933 /* The 0th block becomes the root, move the dirents out */ 1934 fde = &root->dotdot; 1935 de = (struct ext4_dir_entry_2 *)((char *)fde + 1936 ext4_rec_len_from_disk(fde->rec_len, blocksize)); 1937 if ((char *) de >= (((char *) root) + blocksize)) { 1938 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'"); 1939 brelse(bh); 1940 return -EFSCORRUPTED; 1941 } 1942 len = ((char *) root) + (blocksize - csum_size) - (char *) de; 1943 1944 /* Allocate new block for the 0th block's dirents */ 1945 bh2 = ext4_append(handle, dir, &block); 1946 if (IS_ERR(bh2)) { 1947 brelse(bh); 1948 return PTR_ERR(bh2); 1949 } 1950 ext4_set_inode_flag(dir, EXT4_INODE_INDEX); 1951 data1 = bh2->b_data; 1952 1953 memcpy (data1, de, len); 1954 de = (struct ext4_dir_entry_2 *) data1; 1955 top = data1 + len; 1956 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top) 1957 de = de2; 1958 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) - 1959 (char *) de, 1960 blocksize); 1961 1962 if (csum_size) { 1963 t = EXT4_DIRENT_TAIL(data1, blocksize); 1964 initialize_dirent_tail(t, blocksize); 1965 } 1966 1967 /* Initialize the root; the dot dirents already exist */ 1968 de = (struct ext4_dir_entry_2 *) (&root->dotdot); 1969 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2), 1970 blocksize); 1971 memset (&root->info, 0, sizeof(root->info)); 1972 root->info.info_length = sizeof(root->info); 1973 root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version; 1974 entries = root->entries; 1975 dx_set_block(entries, 1); 1976 dx_set_count(entries, 1); 1977 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info))); 1978 1979 /* Initialize as for dx_probe */ 1980 fname->hinfo.hash_version = root->info.hash_version; 1981 if (fname->hinfo.hash_version <= DX_HASH_TEA) 1982 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; 1983 fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; 1984 ext4fs_dirhash(fname_name(fname), fname_len(fname), &fname->hinfo); 1985 1986 memset(frames, 0, sizeof(frames)); 1987 frame = frames; 1988 frame->entries = entries; 1989 frame->at = entries; 1990 frame->bh = bh; 1991 1992 retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 1993 if (retval) 1994 goto out_frames; 1995 retval = ext4_handle_dirty_dirent_node(handle, dir, bh2); 1996 if (retval) 1997 goto out_frames; 1998 1999 de = do_split(handle,dir, &bh2, frame, &fname->hinfo); 2000 if (IS_ERR(de)) { 2001 retval = PTR_ERR(de); 2002 goto out_frames; 2003 } 2004 2005 retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2); 2006 out_frames: 2007 /* 2008 * Even if the block split failed, we have to properly write 2009 * out all the changes we did so far. Otherwise we can end up 2010 * with corrupted filesystem. 2011 */ 2012 if (retval) 2013 ext4_mark_inode_dirty(handle, dir); 2014 dx_release(frames); 2015 brelse(bh2); 2016 return retval; 2017 } 2018 2019 /* 2020 * ext4_add_entry() 2021 * 2022 * adds a file entry to the specified directory, using the same 2023 * semantics as ext4_find_entry(). It returns NULL if it failed. 2024 * 2025 * NOTE!! The inode part of 'de' is left at 0 - which means you 2026 * may not sleep between calling this and putting something into 2027 * the entry, as someone else might have used it while you slept. 2028 */ 2029 static int ext4_add_entry(handle_t *handle, struct dentry *dentry, 2030 struct inode *inode) 2031 { 2032 struct inode *dir = d_inode(dentry->d_parent); 2033 struct buffer_head *bh = NULL; 2034 struct ext4_dir_entry_2 *de; 2035 struct ext4_dir_entry_tail *t; 2036 struct super_block *sb; 2037 struct ext4_filename fname; 2038 int retval; 2039 int dx_fallback=0; 2040 unsigned blocksize; 2041 ext4_lblk_t block, blocks; 2042 int csum_size = 0; 2043 2044 if (ext4_has_metadata_csum(inode->i_sb)) 2045 csum_size = sizeof(struct ext4_dir_entry_tail); 2046 2047 sb = dir->i_sb; 2048 blocksize = sb->s_blocksize; 2049 if (!dentry->d_name.len) 2050 return -EINVAL; 2051 2052 retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname); 2053 if (retval) 2054 return retval; 2055 2056 if (ext4_has_inline_data(dir)) { 2057 retval = ext4_try_add_inline_entry(handle, &fname, dir, inode); 2058 if (retval < 0) 2059 goto out; 2060 if (retval == 1) { 2061 retval = 0; 2062 goto out; 2063 } 2064 } 2065 2066 if (is_dx(dir)) { 2067 retval = ext4_dx_add_entry(handle, &fname, dir, inode); 2068 if (!retval || (retval != ERR_BAD_DX_DIR)) 2069 goto out; 2070 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX); 2071 dx_fallback++; 2072 ext4_mark_inode_dirty(handle, dir); 2073 } 2074 blocks = dir->i_size >> sb->s_blocksize_bits; 2075 for (block = 0; block < blocks; block++) { 2076 bh = ext4_read_dirblock(dir, block, DIRENT); 2077 if (IS_ERR(bh)) { 2078 retval = PTR_ERR(bh); 2079 bh = NULL; 2080 goto out; 2081 } 2082 retval = add_dirent_to_buf(handle, &fname, dir, inode, 2083 NULL, bh); 2084 if (retval != -ENOSPC) 2085 goto out; 2086 2087 if (blocks == 1 && !dx_fallback && 2088 ext4_has_feature_dir_index(sb)) { 2089 retval = make_indexed_dir(handle, &fname, dir, 2090 inode, bh); 2091 bh = NULL; /* make_indexed_dir releases bh */ 2092 goto out; 2093 } 2094 brelse(bh); 2095 } 2096 bh = ext4_append(handle, dir, &block); 2097 if (IS_ERR(bh)) { 2098 retval = PTR_ERR(bh); 2099 bh = NULL; 2100 goto out; 2101 } 2102 de = (struct ext4_dir_entry_2 *) bh->b_data; 2103 de->inode = 0; 2104 de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize); 2105 2106 if (csum_size) { 2107 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize); 2108 initialize_dirent_tail(t, blocksize); 2109 } 2110 2111 retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh); 2112 out: 2113 ext4_fname_free_filename(&fname); 2114 brelse(bh); 2115 if (retval == 0) 2116 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY); 2117 return retval; 2118 } 2119 2120 /* 2121 * Returns 0 for success, or a negative error value 2122 */ 2123 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname, 2124 struct inode *dir, struct inode *inode) 2125 { 2126 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 2127 struct dx_entry *entries, *at; 2128 struct buffer_head *bh; 2129 struct super_block *sb = dir->i_sb; 2130 struct ext4_dir_entry_2 *de; 2131 int restart; 2132 int err; 2133 2134 again: 2135 restart = 0; 2136 frame = dx_probe(fname, dir, NULL, frames); 2137 if (IS_ERR(frame)) 2138 return PTR_ERR(frame); 2139 entries = frame->entries; 2140 at = frame->at; 2141 bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT); 2142 if (IS_ERR(bh)) { 2143 err = PTR_ERR(bh); 2144 bh = NULL; 2145 goto cleanup; 2146 } 2147 2148 BUFFER_TRACE(bh, "get_write_access"); 2149 err = ext4_journal_get_write_access(handle, bh); 2150 if (err) 2151 goto journal_error; 2152 2153 err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh); 2154 if (err != -ENOSPC) 2155 goto cleanup; 2156 2157 err = 0; 2158 /* Block full, should compress but for now just split */ 2159 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n", 2160 dx_get_count(entries), dx_get_limit(entries))); 2161 /* Need to split index? */ 2162 if (dx_get_count(entries) == dx_get_limit(entries)) { 2163 ext4_lblk_t newblock; 2164 int levels = frame - frames + 1; 2165 unsigned int icount; 2166 int add_level = 1; 2167 struct dx_entry *entries2; 2168 struct dx_node *node2; 2169 struct buffer_head *bh2; 2170 2171 while (frame > frames) { 2172 if (dx_get_count((frame - 1)->entries) < 2173 dx_get_limit((frame - 1)->entries)) { 2174 add_level = 0; 2175 break; 2176 } 2177 frame--; /* split higher index block */ 2178 at = frame->at; 2179 entries = frame->entries; 2180 restart = 1; 2181 } 2182 if (add_level && levels == ext4_dir_htree_level(sb)) { 2183 ext4_warning(sb, "Directory (ino: %lu) index full, " 2184 "reach max htree level :%d", 2185 dir->i_ino, levels); 2186 if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) { 2187 ext4_warning(sb, "Large directory feature is " 2188 "not enabled on this " 2189 "filesystem"); 2190 } 2191 err = -ENOSPC; 2192 goto cleanup; 2193 } 2194 icount = dx_get_count(entries); 2195 bh2 = ext4_append(handle, dir, &newblock); 2196 if (IS_ERR(bh2)) { 2197 err = PTR_ERR(bh2); 2198 goto cleanup; 2199 } 2200 node2 = (struct dx_node *)(bh2->b_data); 2201 entries2 = node2->entries; 2202 memset(&node2->fake, 0, sizeof(struct fake_dirent)); 2203 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize, 2204 sb->s_blocksize); 2205 BUFFER_TRACE(frame->bh, "get_write_access"); 2206 err = ext4_journal_get_write_access(handle, frame->bh); 2207 if (err) 2208 goto journal_error; 2209 if (!add_level) { 2210 unsigned icount1 = icount/2, icount2 = icount - icount1; 2211 unsigned hash2 = dx_get_hash(entries + icount1); 2212 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n", 2213 icount1, icount2)); 2214 2215 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */ 2216 err = ext4_journal_get_write_access(handle, 2217 (frame - 1)->bh); 2218 if (err) 2219 goto journal_error; 2220 2221 memcpy((char *) entries2, (char *) (entries + icount1), 2222 icount2 * sizeof(struct dx_entry)); 2223 dx_set_count(entries, icount1); 2224 dx_set_count(entries2, icount2); 2225 dx_set_limit(entries2, dx_node_limit(dir)); 2226 2227 /* Which index block gets the new entry? */ 2228 if (at - entries >= icount1) { 2229 frame->at = at = at - entries - icount1 + entries2; 2230 frame->entries = entries = entries2; 2231 swap(frame->bh, bh2); 2232 } 2233 dx_insert_block((frame - 1), hash2, newblock); 2234 dxtrace(dx_show_index("node", frame->entries)); 2235 dxtrace(dx_show_index("node", 2236 ((struct dx_node *) bh2->b_data)->entries)); 2237 err = ext4_handle_dirty_dx_node(handle, dir, bh2); 2238 if (err) 2239 goto journal_error; 2240 brelse (bh2); 2241 err = ext4_handle_dirty_dx_node(handle, dir, 2242 (frame - 1)->bh); 2243 if (err) 2244 goto journal_error; 2245 if (restart) { 2246 err = ext4_handle_dirty_dx_node(handle, dir, 2247 frame->bh); 2248 goto journal_error; 2249 } 2250 } else { 2251 struct dx_root *dxroot; 2252 memcpy((char *) entries2, (char *) entries, 2253 icount * sizeof(struct dx_entry)); 2254 dx_set_limit(entries2, dx_node_limit(dir)); 2255 2256 /* Set up root */ 2257 dx_set_count(entries, 1); 2258 dx_set_block(entries + 0, newblock); 2259 dxroot = (struct dx_root *)frames[0].bh->b_data; 2260 dxroot->info.indirect_levels += 1; 2261 dxtrace(printk(KERN_DEBUG 2262 "Creating %d level index...\n", 2263 info->indirect_levels)); 2264 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 2265 if (err) 2266 goto journal_error; 2267 err = ext4_handle_dirty_dx_node(handle, dir, bh2); 2268 brelse(bh2); 2269 restart = 1; 2270 goto journal_error; 2271 } 2272 } 2273 de = do_split(handle, dir, &bh, frame, &fname->hinfo); 2274 if (IS_ERR(de)) { 2275 err = PTR_ERR(de); 2276 goto cleanup; 2277 } 2278 err = add_dirent_to_buf(handle, fname, dir, inode, de, bh); 2279 goto cleanup; 2280 2281 journal_error: 2282 ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */ 2283 cleanup: 2284 brelse(bh); 2285 dx_release(frames); 2286 /* @restart is true means htree-path has been changed, we need to 2287 * repeat dx_probe() to find out valid htree-path 2288 */ 2289 if (restart && err == 0) 2290 goto again; 2291 return err; 2292 } 2293 2294 /* 2295 * ext4_generic_delete_entry deletes a directory entry by merging it 2296 * with the previous entry 2297 */ 2298 int ext4_generic_delete_entry(handle_t *handle, 2299 struct inode *dir, 2300 struct ext4_dir_entry_2 *de_del, 2301 struct buffer_head *bh, 2302 void *entry_buf, 2303 int buf_size, 2304 int csum_size) 2305 { 2306 struct ext4_dir_entry_2 *de, *pde; 2307 unsigned int blocksize = dir->i_sb->s_blocksize; 2308 int i; 2309 2310 i = 0; 2311 pde = NULL; 2312 de = (struct ext4_dir_entry_2 *)entry_buf; 2313 while (i < buf_size - csum_size) { 2314 if (ext4_check_dir_entry(dir, NULL, de, bh, 2315 bh->b_data, bh->b_size, i)) 2316 return -EFSCORRUPTED; 2317 if (de == de_del) { 2318 if (pde) 2319 pde->rec_len = ext4_rec_len_to_disk( 2320 ext4_rec_len_from_disk(pde->rec_len, 2321 blocksize) + 2322 ext4_rec_len_from_disk(de->rec_len, 2323 blocksize), 2324 blocksize); 2325 else 2326 de->inode = 0; 2327 inode_inc_iversion(dir); 2328 return 0; 2329 } 2330 i += ext4_rec_len_from_disk(de->rec_len, blocksize); 2331 pde = de; 2332 de = ext4_next_entry(de, blocksize); 2333 } 2334 return -ENOENT; 2335 } 2336 2337 static int ext4_delete_entry(handle_t *handle, 2338 struct inode *dir, 2339 struct ext4_dir_entry_2 *de_del, 2340 struct buffer_head *bh) 2341 { 2342 int err, csum_size = 0; 2343 2344 if (ext4_has_inline_data(dir)) { 2345 int has_inline_data = 1; 2346 err = ext4_delete_inline_entry(handle, dir, de_del, bh, 2347 &has_inline_data); 2348 if (has_inline_data) 2349 return err; 2350 } 2351 2352 if (ext4_has_metadata_csum(dir->i_sb)) 2353 csum_size = sizeof(struct ext4_dir_entry_tail); 2354 2355 BUFFER_TRACE(bh, "get_write_access"); 2356 err = ext4_journal_get_write_access(handle, bh); 2357 if (unlikely(err)) 2358 goto out; 2359 2360 err = ext4_generic_delete_entry(handle, dir, de_del, 2361 bh, bh->b_data, 2362 dir->i_sb->s_blocksize, csum_size); 2363 if (err) 2364 goto out; 2365 2366 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); 2367 err = ext4_handle_dirty_dirent_node(handle, dir, bh); 2368 if (unlikely(err)) 2369 goto out; 2370 2371 return 0; 2372 out: 2373 if (err != -ENOENT) 2374 ext4_std_error(dir->i_sb, err); 2375 return err; 2376 } 2377 2378 /* 2379 * Set directory link count to 1 if nlinks > EXT4_LINK_MAX, or if nlinks == 2 2380 * since this indicates that nlinks count was previously 1 to avoid overflowing 2381 * the 16-bit i_links_count field on disk. Directories with i_nlink == 1 mean 2382 * that subdirectory link counts are not being maintained accurately. 2383 * 2384 * The caller has already checked for i_nlink overflow in case the DIR_LINK 2385 * feature is not enabled and returned -EMLINK. The is_dx() check is a proxy 2386 * for checking S_ISDIR(inode) (since the INODE_INDEX feature will not be set 2387 * on regular files) and to avoid creating huge/slow non-HTREE directories. 2388 */ 2389 static void ext4_inc_count(handle_t *handle, struct inode *inode) 2390 { 2391 inc_nlink(inode); 2392 if (is_dx(inode) && 2393 (inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2)) 2394 set_nlink(inode, 1); 2395 } 2396 2397 /* 2398 * If a directory had nlink == 1, then we should let it be 1. This indicates 2399 * directory has >EXT4_LINK_MAX subdirs. 2400 */ 2401 static void ext4_dec_count(handle_t *handle, struct inode *inode) 2402 { 2403 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2) 2404 drop_nlink(inode); 2405 } 2406 2407 2408 static int ext4_add_nondir(handle_t *handle, 2409 struct dentry *dentry, struct inode *inode) 2410 { 2411 int err = ext4_add_entry(handle, dentry, inode); 2412 if (!err) { 2413 ext4_mark_inode_dirty(handle, inode); 2414 d_instantiate_new(dentry, inode); 2415 return 0; 2416 } 2417 drop_nlink(inode); 2418 unlock_new_inode(inode); 2419 iput(inode); 2420 return err; 2421 } 2422 2423 /* 2424 * By the time this is called, we already have created 2425 * the directory cache entry for the new file, but it 2426 * is so far negative - it has no inode. 2427 * 2428 * If the create succeeds, we fill in the inode information 2429 * with d_instantiate(). 2430 */ 2431 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode, 2432 bool excl) 2433 { 2434 handle_t *handle; 2435 struct inode *inode; 2436 int err, credits, retries = 0; 2437 2438 err = dquot_initialize(dir); 2439 if (err) 2440 return err; 2441 2442 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2443 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2444 retry: 2445 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0, 2446 NULL, EXT4_HT_DIR, credits); 2447 handle = ext4_journal_current_handle(); 2448 err = PTR_ERR(inode); 2449 if (!IS_ERR(inode)) { 2450 inode->i_op = &ext4_file_inode_operations; 2451 inode->i_fop = &ext4_file_operations; 2452 ext4_set_aops(inode); 2453 err = ext4_add_nondir(handle, dentry, inode); 2454 if (!err && IS_DIRSYNC(dir)) 2455 ext4_handle_sync(handle); 2456 } 2457 if (handle) 2458 ext4_journal_stop(handle); 2459 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2460 goto retry; 2461 return err; 2462 } 2463 2464 static int ext4_mknod(struct inode *dir, struct dentry *dentry, 2465 umode_t mode, dev_t rdev) 2466 { 2467 handle_t *handle; 2468 struct inode *inode; 2469 int err, credits, retries = 0; 2470 2471 err = dquot_initialize(dir); 2472 if (err) 2473 return err; 2474 2475 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2476 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2477 retry: 2478 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0, 2479 NULL, EXT4_HT_DIR, credits); 2480 handle = ext4_journal_current_handle(); 2481 err = PTR_ERR(inode); 2482 if (!IS_ERR(inode)) { 2483 init_special_inode(inode, inode->i_mode, rdev); 2484 inode->i_op = &ext4_special_inode_operations; 2485 err = ext4_add_nondir(handle, dentry, inode); 2486 if (!err && IS_DIRSYNC(dir)) 2487 ext4_handle_sync(handle); 2488 } 2489 if (handle) 2490 ext4_journal_stop(handle); 2491 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2492 goto retry; 2493 return err; 2494 } 2495 2496 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) 2497 { 2498 handle_t *handle; 2499 struct inode *inode; 2500 int err, retries = 0; 2501 2502 err = dquot_initialize(dir); 2503 if (err) 2504 return err; 2505 2506 retry: 2507 inode = ext4_new_inode_start_handle(dir, mode, 2508 NULL, 0, NULL, 2509 EXT4_HT_DIR, 2510 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) + 2511 4 + EXT4_XATTR_TRANS_BLOCKS); 2512 handle = ext4_journal_current_handle(); 2513 err = PTR_ERR(inode); 2514 if (!IS_ERR(inode)) { 2515 inode->i_op = &ext4_file_inode_operations; 2516 inode->i_fop = &ext4_file_operations; 2517 ext4_set_aops(inode); 2518 d_tmpfile(dentry, inode); 2519 err = ext4_orphan_add(handle, inode); 2520 if (err) 2521 goto err_unlock_inode; 2522 mark_inode_dirty(inode); 2523 unlock_new_inode(inode); 2524 } 2525 if (handle) 2526 ext4_journal_stop(handle); 2527 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2528 goto retry; 2529 return err; 2530 err_unlock_inode: 2531 ext4_journal_stop(handle); 2532 unlock_new_inode(inode); 2533 return err; 2534 } 2535 2536 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode, 2537 struct ext4_dir_entry_2 *de, 2538 int blocksize, int csum_size, 2539 unsigned int parent_ino, int dotdot_real_len) 2540 { 2541 de->inode = cpu_to_le32(inode->i_ino); 2542 de->name_len = 1; 2543 de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len), 2544 blocksize); 2545 strcpy(de->name, "."); 2546 ext4_set_de_type(inode->i_sb, de, S_IFDIR); 2547 2548 de = ext4_next_entry(de, blocksize); 2549 de->inode = cpu_to_le32(parent_ino); 2550 de->name_len = 2; 2551 if (!dotdot_real_len) 2552 de->rec_len = ext4_rec_len_to_disk(blocksize - 2553 (csum_size + EXT4_DIR_REC_LEN(1)), 2554 blocksize); 2555 else 2556 de->rec_len = ext4_rec_len_to_disk( 2557 EXT4_DIR_REC_LEN(de->name_len), blocksize); 2558 strcpy(de->name, ".."); 2559 ext4_set_de_type(inode->i_sb, de, S_IFDIR); 2560 2561 return ext4_next_entry(de, blocksize); 2562 } 2563 2564 static int ext4_init_new_dir(handle_t *handle, struct inode *dir, 2565 struct inode *inode) 2566 { 2567 struct buffer_head *dir_block = NULL; 2568 struct ext4_dir_entry_2 *de; 2569 struct ext4_dir_entry_tail *t; 2570 ext4_lblk_t block = 0; 2571 unsigned int blocksize = dir->i_sb->s_blocksize; 2572 int csum_size = 0; 2573 int err; 2574 2575 if (ext4_has_metadata_csum(dir->i_sb)) 2576 csum_size = sizeof(struct ext4_dir_entry_tail); 2577 2578 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) { 2579 err = ext4_try_create_inline_dir(handle, dir, inode); 2580 if (err < 0 && err != -ENOSPC) 2581 goto out; 2582 if (!err) 2583 goto out; 2584 } 2585 2586 inode->i_size = 0; 2587 dir_block = ext4_append(handle, inode, &block); 2588 if (IS_ERR(dir_block)) 2589 return PTR_ERR(dir_block); 2590 de = (struct ext4_dir_entry_2 *)dir_block->b_data; 2591 ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0); 2592 set_nlink(inode, 2); 2593 if (csum_size) { 2594 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize); 2595 initialize_dirent_tail(t, blocksize); 2596 } 2597 2598 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata"); 2599 err = ext4_handle_dirty_dirent_node(handle, inode, dir_block); 2600 if (err) 2601 goto out; 2602 set_buffer_verified(dir_block); 2603 out: 2604 brelse(dir_block); 2605 return err; 2606 } 2607 2608 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) 2609 { 2610 handle_t *handle; 2611 struct inode *inode; 2612 int err, credits, retries = 0; 2613 2614 if (EXT4_DIR_LINK_MAX(dir)) 2615 return -EMLINK; 2616 2617 err = dquot_initialize(dir); 2618 if (err) 2619 return err; 2620 2621 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2622 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2623 retry: 2624 inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode, 2625 &dentry->d_name, 2626 0, NULL, EXT4_HT_DIR, credits); 2627 handle = ext4_journal_current_handle(); 2628 err = PTR_ERR(inode); 2629 if (IS_ERR(inode)) 2630 goto out_stop; 2631 2632 inode->i_op = &ext4_dir_inode_operations; 2633 inode->i_fop = &ext4_dir_operations; 2634 err = ext4_init_new_dir(handle, dir, inode); 2635 if (err) 2636 goto out_clear_inode; 2637 err = ext4_mark_inode_dirty(handle, inode); 2638 if (!err) 2639 err = ext4_add_entry(handle, dentry, inode); 2640 if (err) { 2641 out_clear_inode: 2642 clear_nlink(inode); 2643 unlock_new_inode(inode); 2644 ext4_mark_inode_dirty(handle, inode); 2645 iput(inode); 2646 goto out_stop; 2647 } 2648 ext4_inc_count(handle, dir); 2649 ext4_update_dx_flag(dir); 2650 err = ext4_mark_inode_dirty(handle, dir); 2651 if (err) 2652 goto out_clear_inode; 2653 d_instantiate_new(dentry, inode); 2654 if (IS_DIRSYNC(dir)) 2655 ext4_handle_sync(handle); 2656 2657 out_stop: 2658 if (handle) 2659 ext4_journal_stop(handle); 2660 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2661 goto retry; 2662 return err; 2663 } 2664 2665 /* 2666 * routine to check that the specified directory is empty (for rmdir) 2667 */ 2668 bool ext4_empty_dir(struct inode *inode) 2669 { 2670 unsigned int offset; 2671 struct buffer_head *bh; 2672 struct ext4_dir_entry_2 *de, *de1; 2673 struct super_block *sb; 2674 2675 if (ext4_has_inline_data(inode)) { 2676 int has_inline_data = 1; 2677 int ret; 2678 2679 ret = empty_inline_dir(inode, &has_inline_data); 2680 if (has_inline_data) 2681 return ret; 2682 } 2683 2684 sb = inode->i_sb; 2685 if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) { 2686 EXT4_ERROR_INODE(inode, "invalid size"); 2687 return true; 2688 } 2689 bh = ext4_read_dirblock(inode, 0, EITHER); 2690 if (IS_ERR(bh)) 2691 return true; 2692 2693 de = (struct ext4_dir_entry_2 *) bh->b_data; 2694 de1 = ext4_next_entry(de, sb->s_blocksize); 2695 if (le32_to_cpu(de->inode) != inode->i_ino || 2696 le32_to_cpu(de1->inode) == 0 || 2697 strcmp(".", de->name) || strcmp("..", de1->name)) { 2698 ext4_warning_inode(inode, "directory missing '.' and/or '..'"); 2699 brelse(bh); 2700 return true; 2701 } 2702 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) + 2703 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize); 2704 de = ext4_next_entry(de1, sb->s_blocksize); 2705 while (offset < inode->i_size) { 2706 if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) { 2707 unsigned int lblock; 2708 brelse(bh); 2709 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb); 2710 bh = ext4_read_dirblock(inode, lblock, EITHER); 2711 if (IS_ERR(bh)) 2712 return true; 2713 de = (struct ext4_dir_entry_2 *) bh->b_data; 2714 } 2715 if (ext4_check_dir_entry(inode, NULL, de, bh, 2716 bh->b_data, bh->b_size, offset)) { 2717 de = (struct ext4_dir_entry_2 *)(bh->b_data + 2718 sb->s_blocksize); 2719 offset = (offset | (sb->s_blocksize - 1)) + 1; 2720 continue; 2721 } 2722 if (le32_to_cpu(de->inode)) { 2723 brelse(bh); 2724 return false; 2725 } 2726 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); 2727 de = ext4_next_entry(de, sb->s_blocksize); 2728 } 2729 brelse(bh); 2730 return true; 2731 } 2732 2733 /* 2734 * ext4_orphan_add() links an unlinked or truncated inode into a list of 2735 * such inodes, starting at the superblock, in case we crash before the 2736 * file is closed/deleted, or in case the inode truncate spans multiple 2737 * transactions and the last transaction is not recovered after a crash. 2738 * 2739 * At filesystem recovery time, we walk this list deleting unlinked 2740 * inodes and truncating linked inodes in ext4_orphan_cleanup(). 2741 * 2742 * Orphan list manipulation functions must be called under i_mutex unless 2743 * we are just creating the inode or deleting it. 2744 */ 2745 int ext4_orphan_add(handle_t *handle, struct inode *inode) 2746 { 2747 struct super_block *sb = inode->i_sb; 2748 struct ext4_sb_info *sbi = EXT4_SB(sb); 2749 struct ext4_iloc iloc; 2750 int err = 0, rc; 2751 bool dirty = false; 2752 2753 if (!sbi->s_journal || is_bad_inode(inode)) 2754 return 0; 2755 2756 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) && 2757 !inode_is_locked(inode)); 2758 /* 2759 * Exit early if inode already is on orphan list. This is a big speedup 2760 * since we don't have to contend on the global s_orphan_lock. 2761 */ 2762 if (!list_empty(&EXT4_I(inode)->i_orphan)) 2763 return 0; 2764 2765 /* 2766 * Orphan handling is only valid for files with data blocks 2767 * being truncated, or files being unlinked. Note that we either 2768 * hold i_mutex, or the inode can not be referenced from outside, 2769 * so i_nlink should not be bumped due to race 2770 */ 2771 J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 2772 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0); 2773 2774 BUFFER_TRACE(sbi->s_sbh, "get_write_access"); 2775 err = ext4_journal_get_write_access(handle, sbi->s_sbh); 2776 if (err) 2777 goto out; 2778 2779 err = ext4_reserve_inode_write(handle, inode, &iloc); 2780 if (err) 2781 goto out; 2782 2783 mutex_lock(&sbi->s_orphan_lock); 2784 /* 2785 * Due to previous errors inode may be already a part of on-disk 2786 * orphan list. If so skip on-disk list modification. 2787 */ 2788 if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) > 2789 (le32_to_cpu(sbi->s_es->s_inodes_count))) { 2790 /* Insert this inode at the head of the on-disk orphan list */ 2791 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan); 2792 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino); 2793 dirty = true; 2794 } 2795 list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan); 2796 mutex_unlock(&sbi->s_orphan_lock); 2797 2798 if (dirty) { 2799 err = ext4_handle_dirty_super(handle, sb); 2800 rc = ext4_mark_iloc_dirty(handle, inode, &iloc); 2801 if (!err) 2802 err = rc; 2803 if (err) { 2804 /* 2805 * We have to remove inode from in-memory list if 2806 * addition to on disk orphan list failed. Stray orphan 2807 * list entries can cause panics at unmount time. 2808 */ 2809 mutex_lock(&sbi->s_orphan_lock); 2810 list_del_init(&EXT4_I(inode)->i_orphan); 2811 mutex_unlock(&sbi->s_orphan_lock); 2812 } 2813 } 2814 jbd_debug(4, "superblock will point to %lu\n", inode->i_ino); 2815 jbd_debug(4, "orphan inode %lu will point to %d\n", 2816 inode->i_ino, NEXT_ORPHAN(inode)); 2817 out: 2818 ext4_std_error(sb, err); 2819 return err; 2820 } 2821 2822 /* 2823 * ext4_orphan_del() removes an unlinked or truncated inode from the list 2824 * of such inodes stored on disk, because it is finally being cleaned up. 2825 */ 2826 int ext4_orphan_del(handle_t *handle, struct inode *inode) 2827 { 2828 struct list_head *prev; 2829 struct ext4_inode_info *ei = EXT4_I(inode); 2830 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 2831 __u32 ino_next; 2832 struct ext4_iloc iloc; 2833 int err = 0; 2834 2835 if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS)) 2836 return 0; 2837 2838 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) && 2839 !inode_is_locked(inode)); 2840 /* Do this quick check before taking global s_orphan_lock. */ 2841 if (list_empty(&ei->i_orphan)) 2842 return 0; 2843 2844 if (handle) { 2845 /* Grab inode buffer early before taking global s_orphan_lock */ 2846 err = ext4_reserve_inode_write(handle, inode, &iloc); 2847 } 2848 2849 mutex_lock(&sbi->s_orphan_lock); 2850 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino); 2851 2852 prev = ei->i_orphan.prev; 2853 list_del_init(&ei->i_orphan); 2854 2855 /* If we're on an error path, we may not have a valid 2856 * transaction handle with which to update the orphan list on 2857 * disk, but we still need to remove the inode from the linked 2858 * list in memory. */ 2859 if (!handle || err) { 2860 mutex_unlock(&sbi->s_orphan_lock); 2861 goto out_err; 2862 } 2863 2864 ino_next = NEXT_ORPHAN(inode); 2865 if (prev == &sbi->s_orphan) { 2866 jbd_debug(4, "superblock will point to %u\n", ino_next); 2867 BUFFER_TRACE(sbi->s_sbh, "get_write_access"); 2868 err = ext4_journal_get_write_access(handle, sbi->s_sbh); 2869 if (err) { 2870 mutex_unlock(&sbi->s_orphan_lock); 2871 goto out_brelse; 2872 } 2873 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next); 2874 mutex_unlock(&sbi->s_orphan_lock); 2875 err = ext4_handle_dirty_super(handle, inode->i_sb); 2876 } else { 2877 struct ext4_iloc iloc2; 2878 struct inode *i_prev = 2879 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode; 2880 2881 jbd_debug(4, "orphan inode %lu will point to %u\n", 2882 i_prev->i_ino, ino_next); 2883 err = ext4_reserve_inode_write(handle, i_prev, &iloc2); 2884 if (err) { 2885 mutex_unlock(&sbi->s_orphan_lock); 2886 goto out_brelse; 2887 } 2888 NEXT_ORPHAN(i_prev) = ino_next; 2889 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2); 2890 mutex_unlock(&sbi->s_orphan_lock); 2891 } 2892 if (err) 2893 goto out_brelse; 2894 NEXT_ORPHAN(inode) = 0; 2895 err = ext4_mark_iloc_dirty(handle, inode, &iloc); 2896 out_err: 2897 ext4_std_error(inode->i_sb, err); 2898 return err; 2899 2900 out_brelse: 2901 brelse(iloc.bh); 2902 goto out_err; 2903 } 2904 2905 static int ext4_rmdir(struct inode *dir, struct dentry *dentry) 2906 { 2907 int retval; 2908 struct inode *inode; 2909 struct buffer_head *bh; 2910 struct ext4_dir_entry_2 *de; 2911 handle_t *handle = NULL; 2912 2913 if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb)))) 2914 return -EIO; 2915 2916 /* Initialize quotas before so that eventual writes go in 2917 * separate transaction */ 2918 retval = dquot_initialize(dir); 2919 if (retval) 2920 return retval; 2921 retval = dquot_initialize(d_inode(dentry)); 2922 if (retval) 2923 return retval; 2924 2925 retval = -ENOENT; 2926 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); 2927 if (IS_ERR(bh)) 2928 return PTR_ERR(bh); 2929 if (!bh) 2930 goto end_rmdir; 2931 2932 inode = d_inode(dentry); 2933 2934 retval = -EFSCORRUPTED; 2935 if (le32_to_cpu(de->inode) != inode->i_ino) 2936 goto end_rmdir; 2937 2938 retval = -ENOTEMPTY; 2939 if (!ext4_empty_dir(inode)) 2940 goto end_rmdir; 2941 2942 handle = ext4_journal_start(dir, EXT4_HT_DIR, 2943 EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); 2944 if (IS_ERR(handle)) { 2945 retval = PTR_ERR(handle); 2946 handle = NULL; 2947 goto end_rmdir; 2948 } 2949 2950 if (IS_DIRSYNC(dir)) 2951 ext4_handle_sync(handle); 2952 2953 retval = ext4_delete_entry(handle, dir, de, bh); 2954 if (retval) 2955 goto end_rmdir; 2956 if (!EXT4_DIR_LINK_EMPTY(inode)) 2957 ext4_warning_inode(inode, 2958 "empty directory '%.*s' has too many links (%u)", 2959 dentry->d_name.len, dentry->d_name.name, 2960 inode->i_nlink); 2961 inode_inc_iversion(inode); 2962 clear_nlink(inode); 2963 /* There's no need to set i_disksize: the fact that i_nlink is 2964 * zero will ensure that the right thing happens during any 2965 * recovery. */ 2966 inode->i_size = 0; 2967 ext4_orphan_add(handle, inode); 2968 inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode); 2969 ext4_mark_inode_dirty(handle, inode); 2970 ext4_dec_count(handle, dir); 2971 ext4_update_dx_flag(dir); 2972 ext4_mark_inode_dirty(handle, dir); 2973 2974 end_rmdir: 2975 brelse(bh); 2976 if (handle) 2977 ext4_journal_stop(handle); 2978 return retval; 2979 } 2980 2981 static int ext4_unlink(struct inode *dir, struct dentry *dentry) 2982 { 2983 int retval; 2984 struct inode *inode; 2985 struct buffer_head *bh; 2986 struct ext4_dir_entry_2 *de; 2987 handle_t *handle = NULL; 2988 2989 if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb)))) 2990 return -EIO; 2991 2992 trace_ext4_unlink_enter(dir, dentry); 2993 /* Initialize quotas before so that eventual writes go 2994 * in separate transaction */ 2995 retval = dquot_initialize(dir); 2996 if (retval) 2997 return retval; 2998 retval = dquot_initialize(d_inode(dentry)); 2999 if (retval) 3000 return retval; 3001 3002 retval = -ENOENT; 3003 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); 3004 if (IS_ERR(bh)) 3005 return PTR_ERR(bh); 3006 if (!bh) 3007 goto end_unlink; 3008 3009 inode = d_inode(dentry); 3010 3011 retval = -EFSCORRUPTED; 3012 if (le32_to_cpu(de->inode) != inode->i_ino) 3013 goto end_unlink; 3014 3015 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3016 EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); 3017 if (IS_ERR(handle)) { 3018 retval = PTR_ERR(handle); 3019 handle = NULL; 3020 goto end_unlink; 3021 } 3022 3023 if (IS_DIRSYNC(dir)) 3024 ext4_handle_sync(handle); 3025 3026 if (inode->i_nlink == 0) { 3027 ext4_warning_inode(inode, "Deleting file '%.*s' with no links", 3028 dentry->d_name.len, dentry->d_name.name); 3029 set_nlink(inode, 1); 3030 } 3031 retval = ext4_delete_entry(handle, dir, de, bh); 3032 if (retval) 3033 goto end_unlink; 3034 dir->i_ctime = dir->i_mtime = current_time(dir); 3035 ext4_update_dx_flag(dir); 3036 ext4_mark_inode_dirty(handle, dir); 3037 drop_nlink(inode); 3038 if (!inode->i_nlink) 3039 ext4_orphan_add(handle, inode); 3040 inode->i_ctime = current_time(inode); 3041 ext4_mark_inode_dirty(handle, inode); 3042 3043 end_unlink: 3044 brelse(bh); 3045 if (handle) 3046 ext4_journal_stop(handle); 3047 trace_ext4_unlink_exit(dentry, retval); 3048 return retval; 3049 } 3050 3051 static int ext4_symlink(struct inode *dir, 3052 struct dentry *dentry, const char *symname) 3053 { 3054 handle_t *handle; 3055 struct inode *inode; 3056 int err, len = strlen(symname); 3057 int credits; 3058 struct fscrypt_str disk_link; 3059 3060 if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb)))) 3061 return -EIO; 3062 3063 err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize, 3064 &disk_link); 3065 if (err) 3066 return err; 3067 3068 err = dquot_initialize(dir); 3069 if (err) 3070 return err; 3071 3072 if ((disk_link.len > EXT4_N_BLOCKS * 4)) { 3073 /* 3074 * For non-fast symlinks, we just allocate inode and put it on 3075 * orphan list in the first transaction => we need bitmap, 3076 * group descriptor, sb, inode block, quota blocks, and 3077 * possibly selinux xattr blocks. 3078 */ 3079 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) + 3080 EXT4_XATTR_TRANS_BLOCKS; 3081 } else { 3082 /* 3083 * Fast symlink. We have to add entry to directory 3084 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS), 3085 * allocate new inode (bitmap, group descriptor, inode block, 3086 * quota blocks, sb is already counted in previous macros). 3087 */ 3088 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3089 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3; 3090 } 3091 3092 inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO, 3093 &dentry->d_name, 0, NULL, 3094 EXT4_HT_DIR, credits); 3095 handle = ext4_journal_current_handle(); 3096 if (IS_ERR(inode)) { 3097 if (handle) 3098 ext4_journal_stop(handle); 3099 return PTR_ERR(inode); 3100 } 3101 3102 if (IS_ENCRYPTED(inode)) { 3103 err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link); 3104 if (err) 3105 goto err_drop_inode; 3106 inode->i_op = &ext4_encrypted_symlink_inode_operations; 3107 } 3108 3109 if ((disk_link.len > EXT4_N_BLOCKS * 4)) { 3110 if (!IS_ENCRYPTED(inode)) 3111 inode->i_op = &ext4_symlink_inode_operations; 3112 inode_nohighmem(inode); 3113 ext4_set_aops(inode); 3114 /* 3115 * We cannot call page_symlink() with transaction started 3116 * because it calls into ext4_write_begin() which can wait 3117 * for transaction commit if we are running out of space 3118 * and thus we deadlock. So we have to stop transaction now 3119 * and restart it when symlink contents is written. 3120 * 3121 * To keep fs consistent in case of crash, we have to put inode 3122 * to orphan list in the mean time. 3123 */ 3124 drop_nlink(inode); 3125 err = ext4_orphan_add(handle, inode); 3126 ext4_journal_stop(handle); 3127 handle = NULL; 3128 if (err) 3129 goto err_drop_inode; 3130 err = __page_symlink(inode, disk_link.name, disk_link.len, 1); 3131 if (err) 3132 goto err_drop_inode; 3133 /* 3134 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS 3135 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified 3136 */ 3137 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3138 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3139 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1); 3140 if (IS_ERR(handle)) { 3141 err = PTR_ERR(handle); 3142 handle = NULL; 3143 goto err_drop_inode; 3144 } 3145 set_nlink(inode, 1); 3146 err = ext4_orphan_del(handle, inode); 3147 if (err) 3148 goto err_drop_inode; 3149 } else { 3150 /* clear the extent format for fast symlink */ 3151 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS); 3152 if (!IS_ENCRYPTED(inode)) { 3153 inode->i_op = &ext4_fast_symlink_inode_operations; 3154 inode->i_link = (char *)&EXT4_I(inode)->i_data; 3155 } 3156 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name, 3157 disk_link.len); 3158 inode->i_size = disk_link.len - 1; 3159 } 3160 EXT4_I(inode)->i_disksize = inode->i_size; 3161 err = ext4_add_nondir(handle, dentry, inode); 3162 if (!err && IS_DIRSYNC(dir)) 3163 ext4_handle_sync(handle); 3164 3165 if (handle) 3166 ext4_journal_stop(handle); 3167 goto out_free_encrypted_link; 3168 3169 err_drop_inode: 3170 if (handle) 3171 ext4_journal_stop(handle); 3172 clear_nlink(inode); 3173 unlock_new_inode(inode); 3174 iput(inode); 3175 out_free_encrypted_link: 3176 if (disk_link.name != (unsigned char *)symname) 3177 kfree(disk_link.name); 3178 return err; 3179 } 3180 3181 static int ext4_link(struct dentry *old_dentry, 3182 struct inode *dir, struct dentry *dentry) 3183 { 3184 handle_t *handle; 3185 struct inode *inode = d_inode(old_dentry); 3186 int err, retries = 0; 3187 3188 if (inode->i_nlink >= EXT4_LINK_MAX) 3189 return -EMLINK; 3190 3191 err = fscrypt_prepare_link(old_dentry, dir, dentry); 3192 if (err) 3193 return err; 3194 3195 if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) && 3196 (!projid_eq(EXT4_I(dir)->i_projid, 3197 EXT4_I(old_dentry->d_inode)->i_projid))) 3198 return -EXDEV; 3199 3200 err = dquot_initialize(dir); 3201 if (err) 3202 return err; 3203 3204 retry: 3205 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3206 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3207 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1); 3208 if (IS_ERR(handle)) 3209 return PTR_ERR(handle); 3210 3211 if (IS_DIRSYNC(dir)) 3212 ext4_handle_sync(handle); 3213 3214 inode->i_ctime = current_time(inode); 3215 ext4_inc_count(handle, inode); 3216 ihold(inode); 3217 3218 err = ext4_add_entry(handle, dentry, inode); 3219 if (!err) { 3220 ext4_mark_inode_dirty(handle, inode); 3221 /* this can happen only for tmpfile being 3222 * linked the first time 3223 */ 3224 if (inode->i_nlink == 1) 3225 ext4_orphan_del(handle, inode); 3226 d_instantiate(dentry, inode); 3227 } else { 3228 drop_nlink(inode); 3229 iput(inode); 3230 } 3231 ext4_journal_stop(handle); 3232 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 3233 goto retry; 3234 return err; 3235 } 3236 3237 3238 /* 3239 * Try to find buffer head where contains the parent block. 3240 * It should be the inode block if it is inlined or the 1st block 3241 * if it is a normal dir. 3242 */ 3243 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle, 3244 struct inode *inode, 3245 int *retval, 3246 struct ext4_dir_entry_2 **parent_de, 3247 int *inlined) 3248 { 3249 struct buffer_head *bh; 3250 3251 if (!ext4_has_inline_data(inode)) { 3252 bh = ext4_read_dirblock(inode, 0, EITHER); 3253 if (IS_ERR(bh)) { 3254 *retval = PTR_ERR(bh); 3255 return NULL; 3256 } 3257 *parent_de = ext4_next_entry( 3258 (struct ext4_dir_entry_2 *)bh->b_data, 3259 inode->i_sb->s_blocksize); 3260 return bh; 3261 } 3262 3263 *inlined = 1; 3264 return ext4_get_first_inline_block(inode, parent_de, retval); 3265 } 3266 3267 struct ext4_renament { 3268 struct inode *dir; 3269 struct dentry *dentry; 3270 struct inode *inode; 3271 bool is_dir; 3272 int dir_nlink_delta; 3273 3274 /* entry for "dentry" */ 3275 struct buffer_head *bh; 3276 struct ext4_dir_entry_2 *de; 3277 int inlined; 3278 3279 /* entry for ".." in inode if it's a directory */ 3280 struct buffer_head *dir_bh; 3281 struct ext4_dir_entry_2 *parent_de; 3282 int dir_inlined; 3283 }; 3284 3285 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent) 3286 { 3287 int retval; 3288 3289 ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode, 3290 &retval, &ent->parent_de, 3291 &ent->dir_inlined); 3292 if (!ent->dir_bh) 3293 return retval; 3294 if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino) 3295 return -EFSCORRUPTED; 3296 BUFFER_TRACE(ent->dir_bh, "get_write_access"); 3297 return ext4_journal_get_write_access(handle, ent->dir_bh); 3298 } 3299 3300 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent, 3301 unsigned dir_ino) 3302 { 3303 int retval; 3304 3305 ent->parent_de->inode = cpu_to_le32(dir_ino); 3306 BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata"); 3307 if (!ent->dir_inlined) { 3308 if (is_dx(ent->inode)) { 3309 retval = ext4_handle_dirty_dx_node(handle, 3310 ent->inode, 3311 ent->dir_bh); 3312 } else { 3313 retval = ext4_handle_dirty_dirent_node(handle, 3314 ent->inode, 3315 ent->dir_bh); 3316 } 3317 } else { 3318 retval = ext4_mark_inode_dirty(handle, ent->inode); 3319 } 3320 if (retval) { 3321 ext4_std_error(ent->dir->i_sb, retval); 3322 return retval; 3323 } 3324 return 0; 3325 } 3326 3327 static int ext4_setent(handle_t *handle, struct ext4_renament *ent, 3328 unsigned ino, unsigned file_type) 3329 { 3330 int retval; 3331 3332 BUFFER_TRACE(ent->bh, "get write access"); 3333 retval = ext4_journal_get_write_access(handle, ent->bh); 3334 if (retval) 3335 return retval; 3336 ent->de->inode = cpu_to_le32(ino); 3337 if (ext4_has_feature_filetype(ent->dir->i_sb)) 3338 ent->de->file_type = file_type; 3339 inode_inc_iversion(ent->dir); 3340 ent->dir->i_ctime = ent->dir->i_mtime = 3341 current_time(ent->dir); 3342 ext4_mark_inode_dirty(handle, ent->dir); 3343 BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata"); 3344 if (!ent->inlined) { 3345 retval = ext4_handle_dirty_dirent_node(handle, 3346 ent->dir, ent->bh); 3347 if (unlikely(retval)) { 3348 ext4_std_error(ent->dir->i_sb, retval); 3349 return retval; 3350 } 3351 } 3352 brelse(ent->bh); 3353 ent->bh = NULL; 3354 3355 return 0; 3356 } 3357 3358 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir, 3359 const struct qstr *d_name) 3360 { 3361 int retval = -ENOENT; 3362 struct buffer_head *bh; 3363 struct ext4_dir_entry_2 *de; 3364 3365 bh = ext4_find_entry(dir, d_name, &de, NULL); 3366 if (IS_ERR(bh)) 3367 return PTR_ERR(bh); 3368 if (bh) { 3369 retval = ext4_delete_entry(handle, dir, de, bh); 3370 brelse(bh); 3371 } 3372 return retval; 3373 } 3374 3375 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent, 3376 int force_reread) 3377 { 3378 int retval; 3379 /* 3380 * ent->de could have moved from under us during htree split, so make 3381 * sure that we are deleting the right entry. We might also be pointing 3382 * to a stale entry in the unused part of ent->bh so just checking inum 3383 * and the name isn't enough. 3384 */ 3385 if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino || 3386 ent->de->name_len != ent->dentry->d_name.len || 3387 strncmp(ent->de->name, ent->dentry->d_name.name, 3388 ent->de->name_len) || 3389 force_reread) { 3390 retval = ext4_find_delete_entry(handle, ent->dir, 3391 &ent->dentry->d_name); 3392 } else { 3393 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh); 3394 if (retval == -ENOENT) { 3395 retval = ext4_find_delete_entry(handle, ent->dir, 3396 &ent->dentry->d_name); 3397 } 3398 } 3399 3400 if (retval) { 3401 ext4_warning_inode(ent->dir, 3402 "Deleting old file: nlink %d, error=%d", 3403 ent->dir->i_nlink, retval); 3404 } 3405 } 3406 3407 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent) 3408 { 3409 if (ent->dir_nlink_delta) { 3410 if (ent->dir_nlink_delta == -1) 3411 ext4_dec_count(handle, ent->dir); 3412 else 3413 ext4_inc_count(handle, ent->dir); 3414 ext4_mark_inode_dirty(handle, ent->dir); 3415 } 3416 } 3417 3418 static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent, 3419 int credits, handle_t **h) 3420 { 3421 struct inode *wh; 3422 handle_t *handle; 3423 int retries = 0; 3424 3425 /* 3426 * for inode block, sb block, group summaries, 3427 * and inode bitmap 3428 */ 3429 credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) + 3430 EXT4_XATTR_TRANS_BLOCKS + 4); 3431 retry: 3432 wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE, 3433 &ent->dentry->d_name, 0, NULL, 3434 EXT4_HT_DIR, credits); 3435 3436 handle = ext4_journal_current_handle(); 3437 if (IS_ERR(wh)) { 3438 if (handle) 3439 ext4_journal_stop(handle); 3440 if (PTR_ERR(wh) == -ENOSPC && 3441 ext4_should_retry_alloc(ent->dir->i_sb, &retries)) 3442 goto retry; 3443 } else { 3444 *h = handle; 3445 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV); 3446 wh->i_op = &ext4_special_inode_operations; 3447 } 3448 return wh; 3449 } 3450 3451 /* 3452 * Anybody can rename anything with this: the permission checks are left to the 3453 * higher-level routines. 3454 * 3455 * n.b. old_{dentry,inode) refers to the source dentry/inode 3456 * while new_{dentry,inode) refers to the destination dentry/inode 3457 * This comes from rename(const char *oldpath, const char *newpath) 3458 */ 3459 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry, 3460 struct inode *new_dir, struct dentry *new_dentry, 3461 unsigned int flags) 3462 { 3463 handle_t *handle = NULL; 3464 struct ext4_renament old = { 3465 .dir = old_dir, 3466 .dentry = old_dentry, 3467 .inode = d_inode(old_dentry), 3468 }; 3469 struct ext4_renament new = { 3470 .dir = new_dir, 3471 .dentry = new_dentry, 3472 .inode = d_inode(new_dentry), 3473 }; 3474 int force_reread; 3475 int retval; 3476 struct inode *whiteout = NULL; 3477 int credits; 3478 u8 old_file_type; 3479 3480 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) && 3481 (!projid_eq(EXT4_I(new_dir)->i_projid, 3482 EXT4_I(old_dentry->d_inode)->i_projid))) 3483 return -EXDEV; 3484 3485 retval = dquot_initialize(old.dir); 3486 if (retval) 3487 return retval; 3488 retval = dquot_initialize(new.dir); 3489 if (retval) 3490 return retval; 3491 3492 /* Initialize quotas before so that eventual writes go 3493 * in separate transaction */ 3494 if (new.inode) { 3495 retval = dquot_initialize(new.inode); 3496 if (retval) 3497 return retval; 3498 } 3499 3500 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL); 3501 if (IS_ERR(old.bh)) 3502 return PTR_ERR(old.bh); 3503 /* 3504 * Check for inode number is _not_ due to possible IO errors. 3505 * We might rmdir the source, keep it as pwd of some process 3506 * and merrily kill the link to whatever was created under the 3507 * same name. Goodbye sticky bit ;-< 3508 */ 3509 retval = -ENOENT; 3510 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino) 3511 goto end_rename; 3512 3513 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, 3514 &new.de, &new.inlined); 3515 if (IS_ERR(new.bh)) { 3516 retval = PTR_ERR(new.bh); 3517 new.bh = NULL; 3518 goto end_rename; 3519 } 3520 if (new.bh) { 3521 if (!new.inode) { 3522 brelse(new.bh); 3523 new.bh = NULL; 3524 } 3525 } 3526 if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC)) 3527 ext4_alloc_da_blocks(old.inode); 3528 3529 credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + 3530 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2); 3531 if (!(flags & RENAME_WHITEOUT)) { 3532 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits); 3533 if (IS_ERR(handle)) { 3534 retval = PTR_ERR(handle); 3535 handle = NULL; 3536 goto end_rename; 3537 } 3538 } else { 3539 whiteout = ext4_whiteout_for_rename(&old, credits, &handle); 3540 if (IS_ERR(whiteout)) { 3541 retval = PTR_ERR(whiteout); 3542 whiteout = NULL; 3543 goto end_rename; 3544 } 3545 } 3546 3547 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir)) 3548 ext4_handle_sync(handle); 3549 3550 if (S_ISDIR(old.inode->i_mode)) { 3551 if (new.inode) { 3552 retval = -ENOTEMPTY; 3553 if (!ext4_empty_dir(new.inode)) 3554 goto end_rename; 3555 } else { 3556 retval = -EMLINK; 3557 if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir)) 3558 goto end_rename; 3559 } 3560 retval = ext4_rename_dir_prepare(handle, &old); 3561 if (retval) 3562 goto end_rename; 3563 } 3564 /* 3565 * If we're renaming a file within an inline_data dir and adding or 3566 * setting the new dirent causes a conversion from inline_data to 3567 * extents/blockmap, we need to force the dirent delete code to 3568 * re-read the directory, or else we end up trying to delete a dirent 3569 * from what is now the extent tree root (or a block map). 3570 */ 3571 force_reread = (new.dir->i_ino == old.dir->i_ino && 3572 ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA)); 3573 3574 old_file_type = old.de->file_type; 3575 if (whiteout) { 3576 /* 3577 * Do this before adding a new entry, so the old entry is sure 3578 * to be still pointing to the valid old entry. 3579 */ 3580 retval = ext4_setent(handle, &old, whiteout->i_ino, 3581 EXT4_FT_CHRDEV); 3582 if (retval) 3583 goto end_rename; 3584 ext4_mark_inode_dirty(handle, whiteout); 3585 } 3586 if (!new.bh) { 3587 retval = ext4_add_entry(handle, new.dentry, old.inode); 3588 if (retval) 3589 goto end_rename; 3590 } else { 3591 retval = ext4_setent(handle, &new, 3592 old.inode->i_ino, old_file_type); 3593 if (retval) 3594 goto end_rename; 3595 } 3596 if (force_reread) 3597 force_reread = !ext4_test_inode_flag(new.dir, 3598 EXT4_INODE_INLINE_DATA); 3599 3600 /* 3601 * Like most other Unix systems, set the ctime for inodes on a 3602 * rename. 3603 */ 3604 old.inode->i_ctime = current_time(old.inode); 3605 ext4_mark_inode_dirty(handle, old.inode); 3606 3607 if (!whiteout) { 3608 /* 3609 * ok, that's it 3610 */ 3611 ext4_rename_delete(handle, &old, force_reread); 3612 } 3613 3614 if (new.inode) { 3615 ext4_dec_count(handle, new.inode); 3616 new.inode->i_ctime = current_time(new.inode); 3617 } 3618 old.dir->i_ctime = old.dir->i_mtime = current_time(old.dir); 3619 ext4_update_dx_flag(old.dir); 3620 if (old.dir_bh) { 3621 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); 3622 if (retval) 3623 goto end_rename; 3624 3625 ext4_dec_count(handle, old.dir); 3626 if (new.inode) { 3627 /* checked ext4_empty_dir above, can't have another 3628 * parent, ext4_dec_count() won't work for many-linked 3629 * dirs */ 3630 clear_nlink(new.inode); 3631 } else { 3632 ext4_inc_count(handle, new.dir); 3633 ext4_update_dx_flag(new.dir); 3634 ext4_mark_inode_dirty(handle, new.dir); 3635 } 3636 } 3637 ext4_mark_inode_dirty(handle, old.dir); 3638 if (new.inode) { 3639 ext4_mark_inode_dirty(handle, new.inode); 3640 if (!new.inode->i_nlink) 3641 ext4_orphan_add(handle, new.inode); 3642 } 3643 retval = 0; 3644 3645 end_rename: 3646 brelse(old.dir_bh); 3647 brelse(old.bh); 3648 brelse(new.bh); 3649 if (whiteout) { 3650 if (retval) 3651 drop_nlink(whiteout); 3652 unlock_new_inode(whiteout); 3653 iput(whiteout); 3654 } 3655 if (handle) 3656 ext4_journal_stop(handle); 3657 return retval; 3658 } 3659 3660 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry, 3661 struct inode *new_dir, struct dentry *new_dentry) 3662 { 3663 handle_t *handle = NULL; 3664 struct ext4_renament old = { 3665 .dir = old_dir, 3666 .dentry = old_dentry, 3667 .inode = d_inode(old_dentry), 3668 }; 3669 struct ext4_renament new = { 3670 .dir = new_dir, 3671 .dentry = new_dentry, 3672 .inode = d_inode(new_dentry), 3673 }; 3674 u8 new_file_type; 3675 int retval; 3676 struct timespec64 ctime; 3677 3678 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) && 3679 !projid_eq(EXT4_I(new_dir)->i_projid, 3680 EXT4_I(old_dentry->d_inode)->i_projid)) || 3681 (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) && 3682 !projid_eq(EXT4_I(old_dir)->i_projid, 3683 EXT4_I(new_dentry->d_inode)->i_projid))) 3684 return -EXDEV; 3685 3686 retval = dquot_initialize(old.dir); 3687 if (retval) 3688 return retval; 3689 retval = dquot_initialize(new.dir); 3690 if (retval) 3691 return retval; 3692 3693 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, 3694 &old.de, &old.inlined); 3695 if (IS_ERR(old.bh)) 3696 return PTR_ERR(old.bh); 3697 /* 3698 * Check for inode number is _not_ due to possible IO errors. 3699 * We might rmdir the source, keep it as pwd of some process 3700 * and merrily kill the link to whatever was created under the 3701 * same name. Goodbye sticky bit ;-< 3702 */ 3703 retval = -ENOENT; 3704 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino) 3705 goto end_rename; 3706 3707 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, 3708 &new.de, &new.inlined); 3709 if (IS_ERR(new.bh)) { 3710 retval = PTR_ERR(new.bh); 3711 new.bh = NULL; 3712 goto end_rename; 3713 } 3714 3715 /* RENAME_EXCHANGE case: old *and* new must both exist */ 3716 if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino) 3717 goto end_rename; 3718 3719 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, 3720 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + 3721 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2)); 3722 if (IS_ERR(handle)) { 3723 retval = PTR_ERR(handle); 3724 handle = NULL; 3725 goto end_rename; 3726 } 3727 3728 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir)) 3729 ext4_handle_sync(handle); 3730 3731 if (S_ISDIR(old.inode->i_mode)) { 3732 old.is_dir = true; 3733 retval = ext4_rename_dir_prepare(handle, &old); 3734 if (retval) 3735 goto end_rename; 3736 } 3737 if (S_ISDIR(new.inode->i_mode)) { 3738 new.is_dir = true; 3739 retval = ext4_rename_dir_prepare(handle, &new); 3740 if (retval) 3741 goto end_rename; 3742 } 3743 3744 /* 3745 * Other than the special case of overwriting a directory, parents' 3746 * nlink only needs to be modified if this is a cross directory rename. 3747 */ 3748 if (old.dir != new.dir && old.is_dir != new.is_dir) { 3749 old.dir_nlink_delta = old.is_dir ? -1 : 1; 3750 new.dir_nlink_delta = -old.dir_nlink_delta; 3751 retval = -EMLINK; 3752 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) || 3753 (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir))) 3754 goto end_rename; 3755 } 3756 3757 new_file_type = new.de->file_type; 3758 retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type); 3759 if (retval) 3760 goto end_rename; 3761 3762 retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type); 3763 if (retval) 3764 goto end_rename; 3765 3766 /* 3767 * Like most other Unix systems, set the ctime for inodes on a 3768 * rename. 3769 */ 3770 ctime = current_time(old.inode); 3771 old.inode->i_ctime = ctime; 3772 new.inode->i_ctime = ctime; 3773 ext4_mark_inode_dirty(handle, old.inode); 3774 ext4_mark_inode_dirty(handle, new.inode); 3775 3776 if (old.dir_bh) { 3777 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); 3778 if (retval) 3779 goto end_rename; 3780 } 3781 if (new.dir_bh) { 3782 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino); 3783 if (retval) 3784 goto end_rename; 3785 } 3786 ext4_update_dir_count(handle, &old); 3787 ext4_update_dir_count(handle, &new); 3788 retval = 0; 3789 3790 end_rename: 3791 brelse(old.dir_bh); 3792 brelse(new.dir_bh); 3793 brelse(old.bh); 3794 brelse(new.bh); 3795 if (handle) 3796 ext4_journal_stop(handle); 3797 return retval; 3798 } 3799 3800 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry, 3801 struct inode *new_dir, struct dentry *new_dentry, 3802 unsigned int flags) 3803 { 3804 int err; 3805 3806 if (unlikely(ext4_forced_shutdown(EXT4_SB(old_dir->i_sb)))) 3807 return -EIO; 3808 3809 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT)) 3810 return -EINVAL; 3811 3812 err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry, 3813 flags); 3814 if (err) 3815 return err; 3816 3817 if (flags & RENAME_EXCHANGE) { 3818 return ext4_cross_rename(old_dir, old_dentry, 3819 new_dir, new_dentry); 3820 } 3821 3822 return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags); 3823 } 3824 3825 /* 3826 * directories can handle most operations... 3827 */ 3828 const struct inode_operations ext4_dir_inode_operations = { 3829 .create = ext4_create, 3830 .lookup = ext4_lookup, 3831 .link = ext4_link, 3832 .unlink = ext4_unlink, 3833 .symlink = ext4_symlink, 3834 .mkdir = ext4_mkdir, 3835 .rmdir = ext4_rmdir, 3836 .mknod = ext4_mknod, 3837 .tmpfile = ext4_tmpfile, 3838 .rename = ext4_rename2, 3839 .setattr = ext4_setattr, 3840 .getattr = ext4_getattr, 3841 .listxattr = ext4_listxattr, 3842 .get_acl = ext4_get_acl, 3843 .set_acl = ext4_set_acl, 3844 .fiemap = ext4_fiemap, 3845 }; 3846 3847 const struct inode_operations ext4_special_inode_operations = { 3848 .setattr = ext4_setattr, 3849 .getattr = ext4_getattr, 3850 .listxattr = ext4_listxattr, 3851 .get_acl = ext4_get_acl, 3852 .set_acl = ext4_set_acl, 3853 }; 3854