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 <linux/unicode.h> 39 #include "ext4.h" 40 #include "ext4_jbd2.h" 41 42 #include "xattr.h" 43 #include "acl.h" 44 45 #include <trace/events/ext4.h> 46 /* 47 * define how far ahead to read directories while searching them. 48 */ 49 #define NAMEI_RA_CHUNKS 2 50 #define NAMEI_RA_BLOCKS 4 51 #define NAMEI_RA_SIZE (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS) 52 53 static struct buffer_head *ext4_append(handle_t *handle, 54 struct inode *inode, 55 ext4_lblk_t *block) 56 { 57 struct buffer_head *bh; 58 int err; 59 60 if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb && 61 ((inode->i_size >> 10) >= 62 EXT4_SB(inode->i_sb)->s_max_dir_size_kb))) 63 return ERR_PTR(-ENOSPC); 64 65 *block = inode->i_size >> inode->i_sb->s_blocksize_bits; 66 67 bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE); 68 if (IS_ERR(bh)) 69 return bh; 70 inode->i_size += inode->i_sb->s_blocksize; 71 EXT4_I(inode)->i_disksize = inode->i_size; 72 BUFFER_TRACE(bh, "get_write_access"); 73 err = ext4_journal_get_write_access(handle, bh); 74 if (err) { 75 brelse(bh); 76 ext4_std_error(inode->i_sb, err); 77 return ERR_PTR(err); 78 } 79 return bh; 80 } 81 82 static int ext4_dx_csum_verify(struct inode *inode, 83 struct ext4_dir_entry *dirent); 84 85 /* 86 * Hints to ext4_read_dirblock regarding whether we expect a directory 87 * block being read to be an index block, or a block containing 88 * directory entries (and if the latter, whether it was found via a 89 * logical block in an htree index block). This is used to control 90 * what sort of sanity checkinig ext4_read_dirblock() will do on the 91 * directory block read from the storage device. EITHER will means 92 * the caller doesn't know what kind of directory block will be read, 93 * so no specific verification will be done. 94 */ 95 typedef enum { 96 EITHER, INDEX, DIRENT, DIRENT_HTREE 97 } dirblock_type_t; 98 99 #define ext4_read_dirblock(inode, block, type) \ 100 __ext4_read_dirblock((inode), (block), (type), __func__, __LINE__) 101 102 static struct buffer_head *__ext4_read_dirblock(struct inode *inode, 103 ext4_lblk_t block, 104 dirblock_type_t type, 105 const char *func, 106 unsigned int line) 107 { 108 struct buffer_head *bh; 109 struct ext4_dir_entry *dirent; 110 int is_dx_block = 0; 111 112 bh = ext4_bread(NULL, inode, block, 0); 113 if (IS_ERR(bh)) { 114 __ext4_warning(inode->i_sb, func, line, 115 "inode #%lu: lblock %lu: comm %s: " 116 "error %ld reading directory block", 117 inode->i_ino, (unsigned long)block, 118 current->comm, PTR_ERR(bh)); 119 120 return bh; 121 } 122 if (!bh && (type == INDEX || type == DIRENT_HTREE)) { 123 ext4_error_inode(inode, func, line, block, 124 "Directory hole found for htree %s block", 125 (type == INDEX) ? "index" : "leaf"); 126 return ERR_PTR(-EFSCORRUPTED); 127 } 128 if (!bh) 129 return NULL; 130 dirent = (struct ext4_dir_entry *) bh->b_data; 131 /* Determine whether or not we have an index block */ 132 if (is_dx(inode)) { 133 if (block == 0) 134 is_dx_block = 1; 135 else if (ext4_rec_len_from_disk(dirent->rec_len, 136 inode->i_sb->s_blocksize) == 137 inode->i_sb->s_blocksize) 138 is_dx_block = 1; 139 } 140 if (!is_dx_block && type == INDEX) { 141 ext4_error_inode(inode, func, line, block, 142 "directory leaf block found instead of index block"); 143 brelse(bh); 144 return ERR_PTR(-EFSCORRUPTED); 145 } 146 if (!ext4_has_metadata_csum(inode->i_sb) || 147 buffer_verified(bh)) 148 return bh; 149 150 /* 151 * An empty leaf block can get mistaken for a index block; for 152 * this reason, we can only check the index checksum when the 153 * caller is sure it should be an index block. 154 */ 155 if (is_dx_block && type == INDEX) { 156 if (ext4_dx_csum_verify(inode, dirent)) 157 set_buffer_verified(bh); 158 else { 159 ext4_error_inode(inode, func, line, block, 160 "Directory index failed checksum"); 161 brelse(bh); 162 return ERR_PTR(-EFSBADCRC); 163 } 164 } 165 if (!is_dx_block) { 166 if (ext4_dirblock_csum_verify(inode, bh)) 167 set_buffer_verified(bh); 168 else { 169 ext4_error_inode(inode, func, line, block, 170 "Directory block failed checksum"); 171 brelse(bh); 172 return ERR_PTR(-EFSBADCRC); 173 } 174 } 175 return bh; 176 } 177 178 #ifndef assert 179 #define assert(test) J_ASSERT(test) 180 #endif 181 182 #ifdef DX_DEBUG 183 #define dxtrace(command) command 184 #else 185 #define dxtrace(command) 186 #endif 187 188 struct fake_dirent 189 { 190 __le32 inode; 191 __le16 rec_len; 192 u8 name_len; 193 u8 file_type; 194 }; 195 196 struct dx_countlimit 197 { 198 __le16 limit; 199 __le16 count; 200 }; 201 202 struct dx_entry 203 { 204 __le32 hash; 205 __le32 block; 206 }; 207 208 /* 209 * dx_root_info is laid out so that if it should somehow get overlaid by a 210 * dirent the two low bits of the hash version will be zero. Therefore, the 211 * hash version mod 4 should never be 0. Sincerely, the paranoia department. 212 */ 213 214 struct dx_root 215 { 216 struct fake_dirent dot; 217 char dot_name[4]; 218 struct fake_dirent dotdot; 219 char dotdot_name[4]; 220 struct dx_root_info 221 { 222 __le32 reserved_zero; 223 u8 hash_version; 224 u8 info_length; /* 8 */ 225 u8 indirect_levels; 226 u8 unused_flags; 227 } 228 info; 229 struct dx_entry entries[0]; 230 }; 231 232 struct dx_node 233 { 234 struct fake_dirent fake; 235 struct dx_entry entries[0]; 236 }; 237 238 239 struct dx_frame 240 { 241 struct buffer_head *bh; 242 struct dx_entry *entries; 243 struct dx_entry *at; 244 }; 245 246 struct dx_map_entry 247 { 248 u32 hash; 249 u16 offs; 250 u16 size; 251 }; 252 253 /* 254 * This goes at the end of each htree block. 255 */ 256 struct dx_tail { 257 u32 dt_reserved; 258 __le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */ 259 }; 260 261 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry); 262 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value); 263 static inline unsigned dx_get_hash(struct dx_entry *entry); 264 static void dx_set_hash(struct dx_entry *entry, unsigned value); 265 static unsigned dx_get_count(struct dx_entry *entries); 266 static unsigned dx_get_limit(struct dx_entry *entries); 267 static void dx_set_count(struct dx_entry *entries, unsigned value); 268 static void dx_set_limit(struct dx_entry *entries, unsigned value); 269 static unsigned dx_root_limit(struct inode *dir, unsigned infosize); 270 static unsigned dx_node_limit(struct inode *dir); 271 static struct dx_frame *dx_probe(struct ext4_filename *fname, 272 struct inode *dir, 273 struct dx_hash_info *hinfo, 274 struct dx_frame *frame); 275 static void dx_release(struct dx_frame *frames); 276 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de, 277 unsigned blocksize, struct dx_hash_info *hinfo, 278 struct dx_map_entry map[]); 279 static void dx_sort_map(struct dx_map_entry *map, unsigned count); 280 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to, 281 struct dx_map_entry *offsets, int count, unsigned blocksize); 282 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize); 283 static void dx_insert_block(struct dx_frame *frame, 284 u32 hash, ext4_lblk_t block); 285 static int ext4_htree_next_block(struct inode *dir, __u32 hash, 286 struct dx_frame *frame, 287 struct dx_frame *frames, 288 __u32 *start_hash); 289 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, 290 struct ext4_filename *fname, 291 struct ext4_dir_entry_2 **res_dir); 292 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname, 293 struct inode *dir, struct inode *inode); 294 295 /* checksumming functions */ 296 void ext4_initialize_dirent_tail(struct buffer_head *bh, 297 unsigned int blocksize) 298 { 299 struct ext4_dir_entry_tail *t = EXT4_DIRENT_TAIL(bh->b_data, blocksize); 300 301 memset(t, 0, sizeof(struct ext4_dir_entry_tail)); 302 t->det_rec_len = ext4_rec_len_to_disk( 303 sizeof(struct ext4_dir_entry_tail), blocksize); 304 t->det_reserved_ft = EXT4_FT_DIR_CSUM; 305 } 306 307 /* Walk through a dirent block to find a checksum "dirent" at the tail */ 308 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode, 309 struct buffer_head *bh) 310 { 311 struct ext4_dir_entry_tail *t; 312 313 #ifdef PARANOID 314 struct ext4_dir_entry *d, *top; 315 316 d = (struct ext4_dir_entry *)bh->b_data; 317 top = (struct ext4_dir_entry *)(bh->b_data + 318 (EXT4_BLOCK_SIZE(inode->i_sb) - 319 sizeof(struct ext4_dir_entry_tail))); 320 while (d < top && d->rec_len) 321 d = (struct ext4_dir_entry *)(((void *)d) + 322 le16_to_cpu(d->rec_len)); 323 324 if (d != top) 325 return NULL; 326 327 t = (struct ext4_dir_entry_tail *)d; 328 #else 329 t = EXT4_DIRENT_TAIL(bh->b_data, EXT4_BLOCK_SIZE(inode->i_sb)); 330 #endif 331 332 if (t->det_reserved_zero1 || 333 le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) || 334 t->det_reserved_zero2 || 335 t->det_reserved_ft != EXT4_FT_DIR_CSUM) 336 return NULL; 337 338 return t; 339 } 340 341 static __le32 ext4_dirblock_csum(struct inode *inode, void *dirent, int size) 342 { 343 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 344 struct ext4_inode_info *ei = EXT4_I(inode); 345 __u32 csum; 346 347 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size); 348 return cpu_to_le32(csum); 349 } 350 351 #define warn_no_space_for_csum(inode) \ 352 __warn_no_space_for_csum((inode), __func__, __LINE__) 353 354 static void __warn_no_space_for_csum(struct inode *inode, const char *func, 355 unsigned int line) 356 { 357 __ext4_warning_inode(inode, func, line, 358 "No space for directory leaf checksum. Please run e2fsck -D."); 359 } 360 361 int ext4_dirblock_csum_verify(struct inode *inode, struct buffer_head *bh) 362 { 363 struct ext4_dir_entry_tail *t; 364 365 if (!ext4_has_metadata_csum(inode->i_sb)) 366 return 1; 367 368 t = get_dirent_tail(inode, bh); 369 if (!t) { 370 warn_no_space_for_csum(inode); 371 return 0; 372 } 373 374 if (t->det_checksum != ext4_dirblock_csum(inode, bh->b_data, 375 (char *)t - bh->b_data)) 376 return 0; 377 378 return 1; 379 } 380 381 static void ext4_dirblock_csum_set(struct inode *inode, 382 struct buffer_head *bh) 383 { 384 struct ext4_dir_entry_tail *t; 385 386 if (!ext4_has_metadata_csum(inode->i_sb)) 387 return; 388 389 t = get_dirent_tail(inode, bh); 390 if (!t) { 391 warn_no_space_for_csum(inode); 392 return; 393 } 394 395 t->det_checksum = ext4_dirblock_csum(inode, bh->b_data, 396 (char *)t - bh->b_data); 397 } 398 399 int ext4_handle_dirty_dirblock(handle_t *handle, 400 struct inode *inode, 401 struct buffer_head *bh) 402 { 403 ext4_dirblock_csum_set(inode, bh); 404 return ext4_handle_dirty_metadata(handle, inode, bh); 405 } 406 407 static struct dx_countlimit *get_dx_countlimit(struct inode *inode, 408 struct ext4_dir_entry *dirent, 409 int *offset) 410 { 411 struct ext4_dir_entry *dp; 412 struct dx_root_info *root; 413 int count_offset; 414 415 if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb)) 416 count_offset = 8; 417 else if (le16_to_cpu(dirent->rec_len) == 12) { 418 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12); 419 if (le16_to_cpu(dp->rec_len) != 420 EXT4_BLOCK_SIZE(inode->i_sb) - 12) 421 return NULL; 422 root = (struct dx_root_info *)(((void *)dp + 12)); 423 if (root->reserved_zero || 424 root->info_length != sizeof(struct dx_root_info)) 425 return NULL; 426 count_offset = 32; 427 } else 428 return NULL; 429 430 if (offset) 431 *offset = count_offset; 432 return (struct dx_countlimit *)(((void *)dirent) + count_offset); 433 } 434 435 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent, 436 int count_offset, int count, struct dx_tail *t) 437 { 438 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 439 struct ext4_inode_info *ei = EXT4_I(inode); 440 __u32 csum; 441 int size; 442 __u32 dummy_csum = 0; 443 int offset = offsetof(struct dx_tail, dt_checksum); 444 445 size = count_offset + (count * sizeof(struct dx_entry)); 446 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size); 447 csum = ext4_chksum(sbi, csum, (__u8 *)t, offset); 448 csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum)); 449 450 return cpu_to_le32(csum); 451 } 452 453 static int ext4_dx_csum_verify(struct inode *inode, 454 struct ext4_dir_entry *dirent) 455 { 456 struct dx_countlimit *c; 457 struct dx_tail *t; 458 int count_offset, limit, count; 459 460 if (!ext4_has_metadata_csum(inode->i_sb)) 461 return 1; 462 463 c = get_dx_countlimit(inode, dirent, &count_offset); 464 if (!c) { 465 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D."); 466 return 0; 467 } 468 limit = le16_to_cpu(c->limit); 469 count = le16_to_cpu(c->count); 470 if (count_offset + (limit * sizeof(struct dx_entry)) > 471 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) { 472 warn_no_space_for_csum(inode); 473 return 0; 474 } 475 t = (struct dx_tail *)(((struct dx_entry *)c) + limit); 476 477 if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset, 478 count, t)) 479 return 0; 480 return 1; 481 } 482 483 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent) 484 { 485 struct dx_countlimit *c; 486 struct dx_tail *t; 487 int count_offset, limit, count; 488 489 if (!ext4_has_metadata_csum(inode->i_sb)) 490 return; 491 492 c = get_dx_countlimit(inode, dirent, &count_offset); 493 if (!c) { 494 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D."); 495 return; 496 } 497 limit = le16_to_cpu(c->limit); 498 count = le16_to_cpu(c->count); 499 if (count_offset + (limit * sizeof(struct dx_entry)) > 500 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) { 501 warn_no_space_for_csum(inode); 502 return; 503 } 504 t = (struct dx_tail *)(((struct dx_entry *)c) + limit); 505 506 t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t); 507 } 508 509 static inline int ext4_handle_dirty_dx_node(handle_t *handle, 510 struct inode *inode, 511 struct buffer_head *bh) 512 { 513 ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data); 514 return ext4_handle_dirty_metadata(handle, inode, bh); 515 } 516 517 /* 518 * p is at least 6 bytes before the end of page 519 */ 520 static inline struct ext4_dir_entry_2 * 521 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize) 522 { 523 return (struct ext4_dir_entry_2 *)((char *)p + 524 ext4_rec_len_from_disk(p->rec_len, blocksize)); 525 } 526 527 /* 528 * Future: use high four bits of block for coalesce-on-delete flags 529 * Mask them off for now. 530 */ 531 532 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry) 533 { 534 return le32_to_cpu(entry->block) & 0x0fffffff; 535 } 536 537 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value) 538 { 539 entry->block = cpu_to_le32(value); 540 } 541 542 static inline unsigned dx_get_hash(struct dx_entry *entry) 543 { 544 return le32_to_cpu(entry->hash); 545 } 546 547 static inline void dx_set_hash(struct dx_entry *entry, unsigned value) 548 { 549 entry->hash = cpu_to_le32(value); 550 } 551 552 static inline unsigned dx_get_count(struct dx_entry *entries) 553 { 554 return le16_to_cpu(((struct dx_countlimit *) entries)->count); 555 } 556 557 static inline unsigned dx_get_limit(struct dx_entry *entries) 558 { 559 return le16_to_cpu(((struct dx_countlimit *) entries)->limit); 560 } 561 562 static inline void dx_set_count(struct dx_entry *entries, unsigned value) 563 { 564 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value); 565 } 566 567 static inline void dx_set_limit(struct dx_entry *entries, unsigned value) 568 { 569 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value); 570 } 571 572 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize) 573 { 574 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) - 575 EXT4_DIR_REC_LEN(2) - infosize; 576 577 if (ext4_has_metadata_csum(dir->i_sb)) 578 entry_space -= sizeof(struct dx_tail); 579 return entry_space / sizeof(struct dx_entry); 580 } 581 582 static inline unsigned dx_node_limit(struct inode *dir) 583 { 584 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0); 585 586 if (ext4_has_metadata_csum(dir->i_sb)) 587 entry_space -= sizeof(struct dx_tail); 588 return entry_space / sizeof(struct dx_entry); 589 } 590 591 /* 592 * Debug 593 */ 594 #ifdef DX_DEBUG 595 static void dx_show_index(char * label, struct dx_entry *entries) 596 { 597 int i, n = dx_get_count (entries); 598 printk(KERN_DEBUG "%s index", label); 599 for (i = 0; i < n; i++) { 600 printk(KERN_CONT " %x->%lu", 601 i ? dx_get_hash(entries + i) : 0, 602 (unsigned long)dx_get_block(entries + i)); 603 } 604 printk(KERN_CONT "\n"); 605 } 606 607 struct stats 608 { 609 unsigned names; 610 unsigned space; 611 unsigned bcount; 612 }; 613 614 static struct stats dx_show_leaf(struct inode *dir, 615 struct dx_hash_info *hinfo, 616 struct ext4_dir_entry_2 *de, 617 int size, int show_names) 618 { 619 unsigned names = 0, space = 0; 620 char *base = (char *) de; 621 struct dx_hash_info h = *hinfo; 622 623 printk("names: "); 624 while ((char *) de < base + size) 625 { 626 if (de->inode) 627 { 628 if (show_names) 629 { 630 #ifdef CONFIG_FS_ENCRYPTION 631 int len; 632 char *name; 633 struct fscrypt_str fname_crypto_str = 634 FSTR_INIT(NULL, 0); 635 int res = 0; 636 637 name = de->name; 638 len = de->name_len; 639 if (IS_ENCRYPTED(dir)) 640 res = fscrypt_get_encryption_info(dir); 641 if (res) { 642 printk(KERN_WARNING "Error setting up" 643 " fname crypto: %d\n", res); 644 } 645 if (!fscrypt_has_encryption_key(dir)) { 646 /* Directory is not encrypted */ 647 ext4fs_dirhash(dir, de->name, 648 de->name_len, &h); 649 printk("%*.s:(U)%x.%u ", len, 650 name, h.hash, 651 (unsigned) ((char *) de 652 - base)); 653 } else { 654 struct fscrypt_str de_name = 655 FSTR_INIT(name, len); 656 657 /* Directory is encrypted */ 658 res = fscrypt_fname_alloc_buffer( 659 dir, len, 660 &fname_crypto_str); 661 if (res) 662 printk(KERN_WARNING "Error " 663 "allocating crypto " 664 "buffer--skipping " 665 "crypto\n"); 666 res = fscrypt_fname_disk_to_usr(dir, 667 0, 0, &de_name, 668 &fname_crypto_str); 669 if (res) { 670 printk(KERN_WARNING "Error " 671 "converting filename " 672 "from disk to usr" 673 "\n"); 674 name = "??"; 675 len = 2; 676 } else { 677 name = fname_crypto_str.name; 678 len = fname_crypto_str.len; 679 } 680 ext4fs_dirhash(dir, de->name, 681 de->name_len, &h); 682 printk("%*.s:(E)%x.%u ", len, name, 683 h.hash, (unsigned) ((char *) de 684 - base)); 685 fscrypt_fname_free_buffer( 686 &fname_crypto_str); 687 } 688 #else 689 int len = de->name_len; 690 char *name = de->name; 691 ext4fs_dirhash(dir, de->name, de->name_len, &h); 692 printk("%*.s:%x.%u ", len, name, h.hash, 693 (unsigned) ((char *) de - base)); 694 #endif 695 } 696 space += EXT4_DIR_REC_LEN(de->name_len); 697 names++; 698 } 699 de = ext4_next_entry(de, size); 700 } 701 printk(KERN_CONT "(%i)\n", names); 702 return (struct stats) { names, space, 1 }; 703 } 704 705 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir, 706 struct dx_entry *entries, int levels) 707 { 708 unsigned blocksize = dir->i_sb->s_blocksize; 709 unsigned count = dx_get_count(entries), names = 0, space = 0, i; 710 unsigned bcount = 0; 711 struct buffer_head *bh; 712 printk("%i indexed blocks...\n", count); 713 for (i = 0; i < count; i++, entries++) 714 { 715 ext4_lblk_t block = dx_get_block(entries); 716 ext4_lblk_t hash = i ? dx_get_hash(entries): 0; 717 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash; 718 struct stats stats; 719 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range); 720 bh = ext4_bread(NULL,dir, block, 0); 721 if (!bh || IS_ERR(bh)) 722 continue; 723 stats = levels? 724 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1): 725 dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) 726 bh->b_data, blocksize, 0); 727 names += stats.names; 728 space += stats.space; 729 bcount += stats.bcount; 730 brelse(bh); 731 } 732 if (bcount) 733 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n", 734 levels ? "" : " ", names, space/bcount, 735 (space/bcount)*100/blocksize); 736 return (struct stats) { names, space, bcount}; 737 } 738 #endif /* DX_DEBUG */ 739 740 /* 741 * Probe for a directory leaf block to search. 742 * 743 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format 744 * error in the directory index, and the caller should fall back to 745 * searching the directory normally. The callers of dx_probe **MUST** 746 * check for this error code, and make sure it never gets reflected 747 * back to userspace. 748 */ 749 static struct dx_frame * 750 dx_probe(struct ext4_filename *fname, struct inode *dir, 751 struct dx_hash_info *hinfo, struct dx_frame *frame_in) 752 { 753 unsigned count, indirect; 754 struct dx_entry *at, *entries, *p, *q, *m; 755 struct dx_root *root; 756 struct dx_frame *frame = frame_in; 757 struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR); 758 u32 hash; 759 760 memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0])); 761 frame->bh = ext4_read_dirblock(dir, 0, INDEX); 762 if (IS_ERR(frame->bh)) 763 return (struct dx_frame *) frame->bh; 764 765 root = (struct dx_root *) frame->bh->b_data; 766 if (root->info.hash_version != DX_HASH_TEA && 767 root->info.hash_version != DX_HASH_HALF_MD4 && 768 root->info.hash_version != DX_HASH_LEGACY) { 769 ext4_warning_inode(dir, "Unrecognised inode hash code %u", 770 root->info.hash_version); 771 goto fail; 772 } 773 if (fname) 774 hinfo = &fname->hinfo; 775 hinfo->hash_version = root->info.hash_version; 776 if (hinfo->hash_version <= DX_HASH_TEA) 777 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; 778 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed; 779 if (fname && fname_name(fname)) 780 ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), hinfo); 781 hash = hinfo->hash; 782 783 if (root->info.unused_flags & 1) { 784 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x", 785 root->info.unused_flags); 786 goto fail; 787 } 788 789 indirect = root->info.indirect_levels; 790 if (indirect >= ext4_dir_htree_level(dir->i_sb)) { 791 ext4_warning(dir->i_sb, 792 "Directory (ino: %lu) htree depth %#06x exceed" 793 "supported value", dir->i_ino, 794 ext4_dir_htree_level(dir->i_sb)); 795 if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) { 796 ext4_warning(dir->i_sb, "Enable large directory " 797 "feature to access it"); 798 } 799 goto fail; 800 } 801 802 entries = (struct dx_entry *)(((char *)&root->info) + 803 root->info.info_length); 804 805 if (dx_get_limit(entries) != dx_root_limit(dir, 806 root->info.info_length)) { 807 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u", 808 dx_get_limit(entries), 809 dx_root_limit(dir, root->info.info_length)); 810 goto fail; 811 } 812 813 dxtrace(printk("Look up %x", hash)); 814 while (1) { 815 count = dx_get_count(entries); 816 if (!count || count > dx_get_limit(entries)) { 817 ext4_warning_inode(dir, 818 "dx entry: count %u beyond limit %u", 819 count, dx_get_limit(entries)); 820 goto fail; 821 } 822 823 p = entries + 1; 824 q = entries + count - 1; 825 while (p <= q) { 826 m = p + (q - p) / 2; 827 dxtrace(printk(KERN_CONT ".")); 828 if (dx_get_hash(m) > hash) 829 q = m - 1; 830 else 831 p = m + 1; 832 } 833 834 if (0) { // linear search cross check 835 unsigned n = count - 1; 836 at = entries; 837 while (n--) 838 { 839 dxtrace(printk(KERN_CONT ",")); 840 if (dx_get_hash(++at) > hash) 841 { 842 at--; 843 break; 844 } 845 } 846 assert (at == p - 1); 847 } 848 849 at = p - 1; 850 dxtrace(printk(KERN_CONT " %x->%u\n", 851 at == entries ? 0 : dx_get_hash(at), 852 dx_get_block(at))); 853 frame->entries = entries; 854 frame->at = at; 855 if (!indirect--) 856 return frame; 857 frame++; 858 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX); 859 if (IS_ERR(frame->bh)) { 860 ret_err = (struct dx_frame *) frame->bh; 861 frame->bh = NULL; 862 goto fail; 863 } 864 entries = ((struct dx_node *) frame->bh->b_data)->entries; 865 866 if (dx_get_limit(entries) != dx_node_limit(dir)) { 867 ext4_warning_inode(dir, 868 "dx entry: limit %u != node limit %u", 869 dx_get_limit(entries), dx_node_limit(dir)); 870 goto fail; 871 } 872 } 873 fail: 874 while (frame >= frame_in) { 875 brelse(frame->bh); 876 frame--; 877 } 878 879 if (ret_err == ERR_PTR(ERR_BAD_DX_DIR)) 880 ext4_warning_inode(dir, 881 "Corrupt directory, running e2fsck is recommended"); 882 return ret_err; 883 } 884 885 static void dx_release(struct dx_frame *frames) 886 { 887 struct dx_root_info *info; 888 int i; 889 unsigned int indirect_levels; 890 891 if (frames[0].bh == NULL) 892 return; 893 894 info = &((struct dx_root *)frames[0].bh->b_data)->info; 895 /* save local copy, "info" may be freed after brelse() */ 896 indirect_levels = info->indirect_levels; 897 for (i = 0; i <= indirect_levels; i++) { 898 if (frames[i].bh == NULL) 899 break; 900 brelse(frames[i].bh); 901 frames[i].bh = NULL; 902 } 903 } 904 905 /* 906 * This function increments the frame pointer to search the next leaf 907 * block, and reads in the necessary intervening nodes if the search 908 * should be necessary. Whether or not the search is necessary is 909 * controlled by the hash parameter. If the hash value is even, then 910 * the search is only continued if the next block starts with that 911 * hash value. This is used if we are searching for a specific file. 912 * 913 * If the hash value is HASH_NB_ALWAYS, then always go to the next block. 914 * 915 * This function returns 1 if the caller should continue to search, 916 * or 0 if it should not. If there is an error reading one of the 917 * index blocks, it will a negative error code. 918 * 919 * If start_hash is non-null, it will be filled in with the starting 920 * hash of the next page. 921 */ 922 static int ext4_htree_next_block(struct inode *dir, __u32 hash, 923 struct dx_frame *frame, 924 struct dx_frame *frames, 925 __u32 *start_hash) 926 { 927 struct dx_frame *p; 928 struct buffer_head *bh; 929 int num_frames = 0; 930 __u32 bhash; 931 932 p = frame; 933 /* 934 * Find the next leaf page by incrementing the frame pointer. 935 * If we run out of entries in the interior node, loop around and 936 * increment pointer in the parent node. When we break out of 937 * this loop, num_frames indicates the number of interior 938 * nodes need to be read. 939 */ 940 while (1) { 941 if (++(p->at) < p->entries + dx_get_count(p->entries)) 942 break; 943 if (p == frames) 944 return 0; 945 num_frames++; 946 p--; 947 } 948 949 /* 950 * If the hash is 1, then continue only if the next page has a 951 * continuation hash of any value. This is used for readdir 952 * handling. Otherwise, check to see if the hash matches the 953 * desired contiuation hash. If it doesn't, return since 954 * there's no point to read in the successive index pages. 955 */ 956 bhash = dx_get_hash(p->at); 957 if (start_hash) 958 *start_hash = bhash; 959 if ((hash & 1) == 0) { 960 if ((bhash & ~1) != hash) 961 return 0; 962 } 963 /* 964 * If the hash is HASH_NB_ALWAYS, we always go to the next 965 * block so no check is necessary 966 */ 967 while (num_frames--) { 968 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX); 969 if (IS_ERR(bh)) 970 return PTR_ERR(bh); 971 p++; 972 brelse(p->bh); 973 p->bh = bh; 974 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries; 975 } 976 return 1; 977 } 978 979 980 /* 981 * This function fills a red-black tree with information from a 982 * directory block. It returns the number directory entries loaded 983 * into the tree. If there is an error it is returned in err. 984 */ 985 static int htree_dirblock_to_tree(struct file *dir_file, 986 struct inode *dir, ext4_lblk_t block, 987 struct dx_hash_info *hinfo, 988 __u32 start_hash, __u32 start_minor_hash) 989 { 990 struct buffer_head *bh; 991 struct ext4_dir_entry_2 *de, *top; 992 int err = 0, count = 0; 993 struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str; 994 995 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n", 996 (unsigned long)block)); 997 bh = ext4_read_dirblock(dir, block, DIRENT_HTREE); 998 if (IS_ERR(bh)) 999 return PTR_ERR(bh); 1000 1001 de = (struct ext4_dir_entry_2 *) bh->b_data; 1002 top = (struct ext4_dir_entry_2 *) ((char *) de + 1003 dir->i_sb->s_blocksize - 1004 EXT4_DIR_REC_LEN(0)); 1005 #ifdef CONFIG_FS_ENCRYPTION 1006 /* Check if the directory is encrypted */ 1007 if (IS_ENCRYPTED(dir)) { 1008 err = fscrypt_get_encryption_info(dir); 1009 if (err < 0) { 1010 brelse(bh); 1011 return err; 1012 } 1013 err = fscrypt_fname_alloc_buffer(dir, EXT4_NAME_LEN, 1014 &fname_crypto_str); 1015 if (err < 0) { 1016 brelse(bh); 1017 return err; 1018 } 1019 } 1020 #endif 1021 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) { 1022 if (ext4_check_dir_entry(dir, NULL, de, bh, 1023 bh->b_data, bh->b_size, 1024 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb)) 1025 + ((char *)de - bh->b_data))) { 1026 /* silently ignore the rest of the block */ 1027 break; 1028 } 1029 ext4fs_dirhash(dir, de->name, de->name_len, hinfo); 1030 if ((hinfo->hash < start_hash) || 1031 ((hinfo->hash == start_hash) && 1032 (hinfo->minor_hash < start_minor_hash))) 1033 continue; 1034 if (de->inode == 0) 1035 continue; 1036 if (!IS_ENCRYPTED(dir)) { 1037 tmp_str.name = de->name; 1038 tmp_str.len = de->name_len; 1039 err = ext4_htree_store_dirent(dir_file, 1040 hinfo->hash, hinfo->minor_hash, de, 1041 &tmp_str); 1042 } else { 1043 int save_len = fname_crypto_str.len; 1044 struct fscrypt_str de_name = FSTR_INIT(de->name, 1045 de->name_len); 1046 1047 /* Directory is encrypted */ 1048 err = fscrypt_fname_disk_to_usr(dir, hinfo->hash, 1049 hinfo->minor_hash, &de_name, 1050 &fname_crypto_str); 1051 if (err) { 1052 count = err; 1053 goto errout; 1054 } 1055 err = ext4_htree_store_dirent(dir_file, 1056 hinfo->hash, hinfo->minor_hash, de, 1057 &fname_crypto_str); 1058 fname_crypto_str.len = save_len; 1059 } 1060 if (err != 0) { 1061 count = err; 1062 goto errout; 1063 } 1064 count++; 1065 } 1066 errout: 1067 brelse(bh); 1068 #ifdef CONFIG_FS_ENCRYPTION 1069 fscrypt_fname_free_buffer(&fname_crypto_str); 1070 #endif 1071 return count; 1072 } 1073 1074 1075 /* 1076 * This function fills a red-black tree with information from a 1077 * directory. We start scanning the directory in hash order, starting 1078 * at start_hash and start_minor_hash. 1079 * 1080 * This function returns the number of entries inserted into the tree, 1081 * or a negative error code. 1082 */ 1083 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash, 1084 __u32 start_minor_hash, __u32 *next_hash) 1085 { 1086 struct dx_hash_info hinfo; 1087 struct ext4_dir_entry_2 *de; 1088 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 1089 struct inode *dir; 1090 ext4_lblk_t block; 1091 int count = 0; 1092 int ret, err; 1093 __u32 hashval; 1094 struct fscrypt_str tmp_str; 1095 1096 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n", 1097 start_hash, start_minor_hash)); 1098 dir = file_inode(dir_file); 1099 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) { 1100 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version; 1101 if (hinfo.hash_version <= DX_HASH_TEA) 1102 hinfo.hash_version += 1103 EXT4_SB(dir->i_sb)->s_hash_unsigned; 1104 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; 1105 if (ext4_has_inline_data(dir)) { 1106 int has_inline_data = 1; 1107 count = ext4_inlinedir_to_tree(dir_file, dir, 0, 1108 &hinfo, start_hash, 1109 start_minor_hash, 1110 &has_inline_data); 1111 if (has_inline_data) { 1112 *next_hash = ~0; 1113 return count; 1114 } 1115 } 1116 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo, 1117 start_hash, start_minor_hash); 1118 *next_hash = ~0; 1119 return count; 1120 } 1121 hinfo.hash = start_hash; 1122 hinfo.minor_hash = 0; 1123 frame = dx_probe(NULL, dir, &hinfo, frames); 1124 if (IS_ERR(frame)) 1125 return PTR_ERR(frame); 1126 1127 /* Add '.' and '..' from the htree header */ 1128 if (!start_hash && !start_minor_hash) { 1129 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; 1130 tmp_str.name = de->name; 1131 tmp_str.len = de->name_len; 1132 err = ext4_htree_store_dirent(dir_file, 0, 0, 1133 de, &tmp_str); 1134 if (err != 0) 1135 goto errout; 1136 count++; 1137 } 1138 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) { 1139 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; 1140 de = ext4_next_entry(de, dir->i_sb->s_blocksize); 1141 tmp_str.name = de->name; 1142 tmp_str.len = de->name_len; 1143 err = ext4_htree_store_dirent(dir_file, 2, 0, 1144 de, &tmp_str); 1145 if (err != 0) 1146 goto errout; 1147 count++; 1148 } 1149 1150 while (1) { 1151 if (fatal_signal_pending(current)) { 1152 err = -ERESTARTSYS; 1153 goto errout; 1154 } 1155 cond_resched(); 1156 block = dx_get_block(frame->at); 1157 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo, 1158 start_hash, start_minor_hash); 1159 if (ret < 0) { 1160 err = ret; 1161 goto errout; 1162 } 1163 count += ret; 1164 hashval = ~0; 1165 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS, 1166 frame, frames, &hashval); 1167 *next_hash = hashval; 1168 if (ret < 0) { 1169 err = ret; 1170 goto errout; 1171 } 1172 /* 1173 * Stop if: (a) there are no more entries, or 1174 * (b) we have inserted at least one entry and the 1175 * next hash value is not a continuation 1176 */ 1177 if ((ret == 0) || 1178 (count && ((hashval & 1) == 0))) 1179 break; 1180 } 1181 dx_release(frames); 1182 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, " 1183 "next hash: %x\n", count, *next_hash)); 1184 return count; 1185 errout: 1186 dx_release(frames); 1187 return (err); 1188 } 1189 1190 static inline int search_dirblock(struct buffer_head *bh, 1191 struct inode *dir, 1192 struct ext4_filename *fname, 1193 unsigned int offset, 1194 struct ext4_dir_entry_2 **res_dir) 1195 { 1196 return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir, 1197 fname, offset, res_dir); 1198 } 1199 1200 /* 1201 * Directory block splitting, compacting 1202 */ 1203 1204 /* 1205 * Create map of hash values, offsets, and sizes, stored at end of block. 1206 * Returns number of entries mapped. 1207 */ 1208 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de, 1209 unsigned blocksize, struct dx_hash_info *hinfo, 1210 struct dx_map_entry *map_tail) 1211 { 1212 int count = 0; 1213 char *base = (char *) de; 1214 struct dx_hash_info h = *hinfo; 1215 1216 while ((char *) de < base + blocksize) { 1217 if (de->name_len && de->inode) { 1218 ext4fs_dirhash(dir, de->name, de->name_len, &h); 1219 map_tail--; 1220 map_tail->hash = h.hash; 1221 map_tail->offs = ((char *) de - base)>>2; 1222 map_tail->size = le16_to_cpu(de->rec_len); 1223 count++; 1224 cond_resched(); 1225 } 1226 /* XXX: do we need to check rec_len == 0 case? -Chris */ 1227 de = ext4_next_entry(de, blocksize); 1228 } 1229 return count; 1230 } 1231 1232 /* Sort map by hash value */ 1233 static void dx_sort_map (struct dx_map_entry *map, unsigned count) 1234 { 1235 struct dx_map_entry *p, *q, *top = map + count - 1; 1236 int more; 1237 /* Combsort until bubble sort doesn't suck */ 1238 while (count > 2) { 1239 count = count*10/13; 1240 if (count - 9 < 2) /* 9, 10 -> 11 */ 1241 count = 11; 1242 for (p = top, q = p - count; q >= map; p--, q--) 1243 if (p->hash < q->hash) 1244 swap(*p, *q); 1245 } 1246 /* Garden variety bubble sort */ 1247 do { 1248 more = 0; 1249 q = top; 1250 while (q-- > map) { 1251 if (q[1].hash >= q[0].hash) 1252 continue; 1253 swap(*(q+1), *q); 1254 more = 1; 1255 } 1256 } while(more); 1257 } 1258 1259 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block) 1260 { 1261 struct dx_entry *entries = frame->entries; 1262 struct dx_entry *old = frame->at, *new = old + 1; 1263 int count = dx_get_count(entries); 1264 1265 assert(count < dx_get_limit(entries)); 1266 assert(old < entries + count); 1267 memmove(new + 1, new, (char *)(entries + count) - (char *)(new)); 1268 dx_set_hash(new, hash); 1269 dx_set_block(new, block); 1270 dx_set_count(entries, count + 1); 1271 } 1272 1273 #ifdef CONFIG_UNICODE 1274 /* 1275 * Test whether a case-insensitive directory entry matches the filename 1276 * being searched for. If quick is set, assume the name being looked up 1277 * is already in the casefolded form. 1278 * 1279 * Returns: 0 if the directory entry matches, more than 0 if it 1280 * doesn't match or less than zero on error. 1281 */ 1282 int ext4_ci_compare(const struct inode *parent, const struct qstr *name, 1283 const struct qstr *entry, bool quick) 1284 { 1285 const struct ext4_sb_info *sbi = EXT4_SB(parent->i_sb); 1286 const struct unicode_map *um = sbi->s_encoding; 1287 int ret; 1288 1289 if (quick) 1290 ret = utf8_strncasecmp_folded(um, name, entry); 1291 else 1292 ret = utf8_strncasecmp(um, name, entry); 1293 1294 if (ret < 0) { 1295 /* Handle invalid character sequence as either an error 1296 * or as an opaque byte sequence. 1297 */ 1298 if (ext4_has_strict_mode(sbi)) 1299 return -EINVAL; 1300 1301 if (name->len != entry->len) 1302 return 1; 1303 1304 return !!memcmp(name->name, entry->name, name->len); 1305 } 1306 1307 return ret; 1308 } 1309 1310 void ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname, 1311 struct fscrypt_str *cf_name) 1312 { 1313 int len; 1314 1315 if (!IS_CASEFOLDED(dir)) { 1316 cf_name->name = NULL; 1317 return; 1318 } 1319 1320 cf_name->name = kmalloc(EXT4_NAME_LEN, GFP_NOFS); 1321 if (!cf_name->name) 1322 return; 1323 1324 len = utf8_casefold(EXT4_SB(dir->i_sb)->s_encoding, 1325 iname, cf_name->name, 1326 EXT4_NAME_LEN); 1327 if (len <= 0) { 1328 kfree(cf_name->name); 1329 cf_name->name = NULL; 1330 return; 1331 } 1332 cf_name->len = (unsigned) len; 1333 1334 } 1335 #endif 1336 1337 /* 1338 * Test whether a directory entry matches the filename being searched for. 1339 * 1340 * Return: %true if the directory entry matches, otherwise %false. 1341 */ 1342 static inline bool ext4_match(const struct inode *parent, 1343 const struct ext4_filename *fname, 1344 const struct ext4_dir_entry_2 *de) 1345 { 1346 struct fscrypt_name f; 1347 #ifdef CONFIG_UNICODE 1348 const struct qstr entry = {.name = de->name, .len = de->name_len}; 1349 #endif 1350 1351 if (!de->inode) 1352 return false; 1353 1354 f.usr_fname = fname->usr_fname; 1355 f.disk_name = fname->disk_name; 1356 #ifdef CONFIG_FS_ENCRYPTION 1357 f.crypto_buf = fname->crypto_buf; 1358 #endif 1359 1360 #ifdef CONFIG_UNICODE 1361 if (EXT4_SB(parent->i_sb)->s_encoding && IS_CASEFOLDED(parent)) { 1362 if (fname->cf_name.name) { 1363 struct qstr cf = {.name = fname->cf_name.name, 1364 .len = fname->cf_name.len}; 1365 return !ext4_ci_compare(parent, &cf, &entry, true); 1366 } 1367 return !ext4_ci_compare(parent, fname->usr_fname, &entry, 1368 false); 1369 } 1370 #endif 1371 1372 return fscrypt_match_name(&f, de->name, de->name_len); 1373 } 1374 1375 /* 1376 * Returns 0 if not found, -1 on failure, and 1 on success 1377 */ 1378 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size, 1379 struct inode *dir, struct ext4_filename *fname, 1380 unsigned int offset, struct ext4_dir_entry_2 **res_dir) 1381 { 1382 struct ext4_dir_entry_2 * de; 1383 char * dlimit; 1384 int de_len; 1385 1386 de = (struct ext4_dir_entry_2 *)search_buf; 1387 dlimit = search_buf + buf_size; 1388 while ((char *) de < dlimit) { 1389 /* this code is executed quadratically often */ 1390 /* do minimal checking `by hand' */ 1391 if ((char *) de + de->name_len <= dlimit && 1392 ext4_match(dir, fname, de)) { 1393 /* found a match - just to be sure, do 1394 * a full check */ 1395 if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data, 1396 bh->b_size, offset)) 1397 return -1; 1398 *res_dir = de; 1399 return 1; 1400 } 1401 /* prevent looping on a bad block */ 1402 de_len = ext4_rec_len_from_disk(de->rec_len, 1403 dir->i_sb->s_blocksize); 1404 if (de_len <= 0) 1405 return -1; 1406 offset += de_len; 1407 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len); 1408 } 1409 return 0; 1410 } 1411 1412 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block, 1413 struct ext4_dir_entry *de) 1414 { 1415 struct super_block *sb = dir->i_sb; 1416 1417 if (!is_dx(dir)) 1418 return 0; 1419 if (block == 0) 1420 return 1; 1421 if (de->inode == 0 && 1422 ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) == 1423 sb->s_blocksize) 1424 return 1; 1425 return 0; 1426 } 1427 1428 /* 1429 * __ext4_find_entry() 1430 * 1431 * finds an entry in the specified directory with the wanted name. It 1432 * returns the cache buffer in which the entry was found, and the entry 1433 * itself (as a parameter - res_dir). It does NOT read the inode of the 1434 * entry - you'll have to do that yourself if you want to. 1435 * 1436 * The returned buffer_head has ->b_count elevated. The caller is expected 1437 * to brelse() it when appropriate. 1438 */ 1439 static struct buffer_head *__ext4_find_entry(struct inode *dir, 1440 struct ext4_filename *fname, 1441 struct ext4_dir_entry_2 **res_dir, 1442 int *inlined) 1443 { 1444 struct super_block *sb; 1445 struct buffer_head *bh_use[NAMEI_RA_SIZE]; 1446 struct buffer_head *bh, *ret = NULL; 1447 ext4_lblk_t start, block; 1448 const u8 *name = fname->usr_fname->name; 1449 size_t ra_max = 0; /* Number of bh's in the readahead 1450 buffer, bh_use[] */ 1451 size_t ra_ptr = 0; /* Current index into readahead 1452 buffer */ 1453 ext4_lblk_t nblocks; 1454 int i, namelen, retval; 1455 1456 *res_dir = NULL; 1457 sb = dir->i_sb; 1458 namelen = fname->usr_fname->len; 1459 if (namelen > EXT4_NAME_LEN) 1460 return NULL; 1461 1462 if (ext4_has_inline_data(dir)) { 1463 int has_inline_data = 1; 1464 ret = ext4_find_inline_entry(dir, fname, res_dir, 1465 &has_inline_data); 1466 if (has_inline_data) { 1467 if (inlined) 1468 *inlined = 1; 1469 goto cleanup_and_exit; 1470 } 1471 } 1472 1473 if ((namelen <= 2) && (name[0] == '.') && 1474 (name[1] == '.' || name[1] == '\0')) { 1475 /* 1476 * "." or ".." will only be in the first block 1477 * NFS may look up ".."; "." should be handled by the VFS 1478 */ 1479 block = start = 0; 1480 nblocks = 1; 1481 goto restart; 1482 } 1483 if (is_dx(dir)) { 1484 ret = ext4_dx_find_entry(dir, fname, res_dir); 1485 /* 1486 * On success, or if the error was file not found, 1487 * return. Otherwise, fall back to doing a search the 1488 * old fashioned way. 1489 */ 1490 if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR) 1491 goto cleanup_and_exit; 1492 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, " 1493 "falling back\n")); 1494 ret = NULL; 1495 } 1496 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); 1497 if (!nblocks) { 1498 ret = NULL; 1499 goto cleanup_and_exit; 1500 } 1501 start = EXT4_I(dir)->i_dir_start_lookup; 1502 if (start >= nblocks) 1503 start = 0; 1504 block = start; 1505 restart: 1506 do { 1507 /* 1508 * We deal with the read-ahead logic here. 1509 */ 1510 if (ra_ptr >= ra_max) { 1511 /* Refill the readahead buffer */ 1512 ra_ptr = 0; 1513 if (block < start) 1514 ra_max = start - block; 1515 else 1516 ra_max = nblocks - block; 1517 ra_max = min(ra_max, ARRAY_SIZE(bh_use)); 1518 retval = ext4_bread_batch(dir, block, ra_max, 1519 false /* wait */, bh_use); 1520 if (retval) { 1521 ret = ERR_PTR(retval); 1522 ra_max = 0; 1523 goto cleanup_and_exit; 1524 } 1525 } 1526 if ((bh = bh_use[ra_ptr++]) == NULL) 1527 goto next; 1528 wait_on_buffer(bh); 1529 if (!buffer_uptodate(bh)) { 1530 EXT4_ERROR_INODE(dir, "reading directory lblock %lu", 1531 (unsigned long) block); 1532 brelse(bh); 1533 ret = ERR_PTR(-EIO); 1534 goto cleanup_and_exit; 1535 } 1536 if (!buffer_verified(bh) && 1537 !is_dx_internal_node(dir, block, 1538 (struct ext4_dir_entry *)bh->b_data) && 1539 !ext4_dirblock_csum_verify(dir, bh)) { 1540 EXT4_ERROR_INODE(dir, "checksumming directory " 1541 "block %lu", (unsigned long)block); 1542 brelse(bh); 1543 ret = ERR_PTR(-EFSBADCRC); 1544 goto cleanup_and_exit; 1545 } 1546 set_buffer_verified(bh); 1547 i = search_dirblock(bh, dir, fname, 1548 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir); 1549 if (i == 1) { 1550 EXT4_I(dir)->i_dir_start_lookup = block; 1551 ret = bh; 1552 goto cleanup_and_exit; 1553 } else { 1554 brelse(bh); 1555 if (i < 0) 1556 goto cleanup_and_exit; 1557 } 1558 next: 1559 if (++block >= nblocks) 1560 block = 0; 1561 } while (block != start); 1562 1563 /* 1564 * If the directory has grown while we were searching, then 1565 * search the last part of the directory before giving up. 1566 */ 1567 block = nblocks; 1568 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); 1569 if (block < nblocks) { 1570 start = 0; 1571 goto restart; 1572 } 1573 1574 cleanup_and_exit: 1575 /* Clean up the read-ahead blocks */ 1576 for (; ra_ptr < ra_max; ra_ptr++) 1577 brelse(bh_use[ra_ptr]); 1578 return ret; 1579 } 1580 1581 static struct buffer_head *ext4_find_entry(struct inode *dir, 1582 const struct qstr *d_name, 1583 struct ext4_dir_entry_2 **res_dir, 1584 int *inlined) 1585 { 1586 int err; 1587 struct ext4_filename fname; 1588 struct buffer_head *bh; 1589 1590 err = ext4_fname_setup_filename(dir, d_name, 1, &fname); 1591 if (err == -ENOENT) 1592 return NULL; 1593 if (err) 1594 return ERR_PTR(err); 1595 1596 bh = __ext4_find_entry(dir, &fname, res_dir, inlined); 1597 1598 ext4_fname_free_filename(&fname); 1599 return bh; 1600 } 1601 1602 static struct buffer_head *ext4_lookup_entry(struct inode *dir, 1603 struct dentry *dentry, 1604 struct ext4_dir_entry_2 **res_dir) 1605 { 1606 int err; 1607 struct ext4_filename fname; 1608 struct buffer_head *bh; 1609 1610 err = ext4_fname_prepare_lookup(dir, dentry, &fname); 1611 if (err == -ENOENT) 1612 return NULL; 1613 if (err) 1614 return ERR_PTR(err); 1615 1616 bh = __ext4_find_entry(dir, &fname, res_dir, NULL); 1617 1618 ext4_fname_free_filename(&fname); 1619 return bh; 1620 } 1621 1622 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, 1623 struct ext4_filename *fname, 1624 struct ext4_dir_entry_2 **res_dir) 1625 { 1626 struct super_block * sb = dir->i_sb; 1627 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 1628 struct buffer_head *bh; 1629 ext4_lblk_t block; 1630 int retval; 1631 1632 #ifdef CONFIG_FS_ENCRYPTION 1633 *res_dir = NULL; 1634 #endif 1635 frame = dx_probe(fname, dir, NULL, frames); 1636 if (IS_ERR(frame)) 1637 return (struct buffer_head *) frame; 1638 do { 1639 block = dx_get_block(frame->at); 1640 bh = ext4_read_dirblock(dir, block, DIRENT_HTREE); 1641 if (IS_ERR(bh)) 1642 goto errout; 1643 1644 retval = search_dirblock(bh, dir, fname, 1645 block << EXT4_BLOCK_SIZE_BITS(sb), 1646 res_dir); 1647 if (retval == 1) 1648 goto success; 1649 brelse(bh); 1650 if (retval == -1) { 1651 bh = ERR_PTR(ERR_BAD_DX_DIR); 1652 goto errout; 1653 } 1654 1655 /* Check to see if we should continue to search */ 1656 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame, 1657 frames, NULL); 1658 if (retval < 0) { 1659 ext4_warning_inode(dir, 1660 "error %d reading directory index block", 1661 retval); 1662 bh = ERR_PTR(retval); 1663 goto errout; 1664 } 1665 } while (retval == 1); 1666 1667 bh = NULL; 1668 errout: 1669 dxtrace(printk(KERN_DEBUG "%s not found\n", fname->usr_fname->name)); 1670 success: 1671 dx_release(frames); 1672 return bh; 1673 } 1674 1675 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 1676 { 1677 struct inode *inode; 1678 struct ext4_dir_entry_2 *de; 1679 struct buffer_head *bh; 1680 1681 if (dentry->d_name.len > EXT4_NAME_LEN) 1682 return ERR_PTR(-ENAMETOOLONG); 1683 1684 bh = ext4_lookup_entry(dir, dentry, &de); 1685 if (IS_ERR(bh)) 1686 return ERR_CAST(bh); 1687 inode = NULL; 1688 if (bh) { 1689 __u32 ino = le32_to_cpu(de->inode); 1690 brelse(bh); 1691 if (!ext4_valid_inum(dir->i_sb, ino)) { 1692 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino); 1693 return ERR_PTR(-EFSCORRUPTED); 1694 } 1695 if (unlikely(ino == dir->i_ino)) { 1696 EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir", 1697 dentry); 1698 return ERR_PTR(-EFSCORRUPTED); 1699 } 1700 inode = ext4_iget(dir->i_sb, ino, EXT4_IGET_NORMAL); 1701 if (inode == ERR_PTR(-ESTALE)) { 1702 EXT4_ERROR_INODE(dir, 1703 "deleted inode referenced: %u", 1704 ino); 1705 return ERR_PTR(-EFSCORRUPTED); 1706 } 1707 if (!IS_ERR(inode) && IS_ENCRYPTED(dir) && 1708 (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) && 1709 !fscrypt_has_permitted_context(dir, inode)) { 1710 ext4_warning(inode->i_sb, 1711 "Inconsistent encryption contexts: %lu/%lu", 1712 dir->i_ino, inode->i_ino); 1713 iput(inode); 1714 return ERR_PTR(-EPERM); 1715 } 1716 } 1717 1718 #ifdef CONFIG_UNICODE 1719 if (!inode && IS_CASEFOLDED(dir)) { 1720 /* Eventually we want to call d_add_ci(dentry, NULL) 1721 * for negative dentries in the encoding case as 1722 * well. For now, prevent the negative dentry 1723 * from being cached. 1724 */ 1725 return NULL; 1726 } 1727 #endif 1728 return d_splice_alias(inode, dentry); 1729 } 1730 1731 1732 struct dentry *ext4_get_parent(struct dentry *child) 1733 { 1734 __u32 ino; 1735 static const struct qstr dotdot = QSTR_INIT("..", 2); 1736 struct ext4_dir_entry_2 * de; 1737 struct buffer_head *bh; 1738 1739 bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL); 1740 if (IS_ERR(bh)) 1741 return ERR_CAST(bh); 1742 if (!bh) 1743 return ERR_PTR(-ENOENT); 1744 ino = le32_to_cpu(de->inode); 1745 brelse(bh); 1746 1747 if (!ext4_valid_inum(child->d_sb, ino)) { 1748 EXT4_ERROR_INODE(d_inode(child), 1749 "bad parent inode number: %u", ino); 1750 return ERR_PTR(-EFSCORRUPTED); 1751 } 1752 1753 return d_obtain_alias(ext4_iget(child->d_sb, ino, EXT4_IGET_NORMAL)); 1754 } 1755 1756 /* 1757 * Move count entries from end of map between two memory locations. 1758 * Returns pointer to last entry moved. 1759 */ 1760 static struct ext4_dir_entry_2 * 1761 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count, 1762 unsigned blocksize) 1763 { 1764 unsigned rec_len = 0; 1765 1766 while (count--) { 1767 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) 1768 (from + (map->offs<<2)); 1769 rec_len = EXT4_DIR_REC_LEN(de->name_len); 1770 memcpy (to, de, rec_len); 1771 ((struct ext4_dir_entry_2 *) to)->rec_len = 1772 ext4_rec_len_to_disk(rec_len, blocksize); 1773 de->inode = 0; 1774 map++; 1775 to += rec_len; 1776 } 1777 return (struct ext4_dir_entry_2 *) (to - rec_len); 1778 } 1779 1780 /* 1781 * Compact each dir entry in the range to the minimal rec_len. 1782 * Returns pointer to last entry in range. 1783 */ 1784 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize) 1785 { 1786 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base; 1787 unsigned rec_len = 0; 1788 1789 prev = to = de; 1790 while ((char*)de < base + blocksize) { 1791 next = ext4_next_entry(de, blocksize); 1792 if (de->inode && de->name_len) { 1793 rec_len = EXT4_DIR_REC_LEN(de->name_len); 1794 if (de > to) 1795 memmove(to, de, rec_len); 1796 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize); 1797 prev = to; 1798 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len); 1799 } 1800 de = next; 1801 } 1802 return prev; 1803 } 1804 1805 /* 1806 * Split a full leaf block to make room for a new dir entry. 1807 * Allocate a new block, and move entries so that they are approx. equally full. 1808 * Returns pointer to de in block into which the new entry will be inserted. 1809 */ 1810 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir, 1811 struct buffer_head **bh,struct dx_frame *frame, 1812 struct dx_hash_info *hinfo) 1813 { 1814 unsigned blocksize = dir->i_sb->s_blocksize; 1815 unsigned count, continued; 1816 struct buffer_head *bh2; 1817 ext4_lblk_t newblock; 1818 u32 hash2; 1819 struct dx_map_entry *map; 1820 char *data1 = (*bh)->b_data, *data2; 1821 unsigned split, move, size; 1822 struct ext4_dir_entry_2 *de = NULL, *de2; 1823 int csum_size = 0; 1824 int err = 0, i; 1825 1826 if (ext4_has_metadata_csum(dir->i_sb)) 1827 csum_size = sizeof(struct ext4_dir_entry_tail); 1828 1829 bh2 = ext4_append(handle, dir, &newblock); 1830 if (IS_ERR(bh2)) { 1831 brelse(*bh); 1832 *bh = NULL; 1833 return (struct ext4_dir_entry_2 *) bh2; 1834 } 1835 1836 BUFFER_TRACE(*bh, "get_write_access"); 1837 err = ext4_journal_get_write_access(handle, *bh); 1838 if (err) 1839 goto journal_error; 1840 1841 BUFFER_TRACE(frame->bh, "get_write_access"); 1842 err = ext4_journal_get_write_access(handle, frame->bh); 1843 if (err) 1844 goto journal_error; 1845 1846 data2 = bh2->b_data; 1847 1848 /* create map in the end of data2 block */ 1849 map = (struct dx_map_entry *) (data2 + blocksize); 1850 count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1, 1851 blocksize, hinfo, map); 1852 map -= count; 1853 dx_sort_map(map, count); 1854 /* Split the existing block in the middle, size-wise */ 1855 size = 0; 1856 move = 0; 1857 for (i = count-1; i >= 0; i--) { 1858 /* is more than half of this entry in 2nd half of the block? */ 1859 if (size + map[i].size/2 > blocksize/2) 1860 break; 1861 size += map[i].size; 1862 move++; 1863 } 1864 /* map index at which we will split */ 1865 split = count - move; 1866 hash2 = map[split].hash; 1867 continued = hash2 == map[split - 1].hash; 1868 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n", 1869 (unsigned long)dx_get_block(frame->at), 1870 hash2, split, count-split)); 1871 1872 /* Fancy dance to stay within two buffers */ 1873 de2 = dx_move_dirents(data1, data2, map + split, count - split, 1874 blocksize); 1875 de = dx_pack_dirents(data1, blocksize); 1876 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) - 1877 (char *) de, 1878 blocksize); 1879 de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) - 1880 (char *) de2, 1881 blocksize); 1882 if (csum_size) { 1883 ext4_initialize_dirent_tail(*bh, blocksize); 1884 ext4_initialize_dirent_tail(bh2, blocksize); 1885 } 1886 1887 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1, 1888 blocksize, 1)); 1889 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2, 1890 blocksize, 1)); 1891 1892 /* Which block gets the new entry? */ 1893 if (hinfo->hash >= hash2) { 1894 swap(*bh, bh2); 1895 de = de2; 1896 } 1897 dx_insert_block(frame, hash2 + continued, newblock); 1898 err = ext4_handle_dirty_dirblock(handle, dir, bh2); 1899 if (err) 1900 goto journal_error; 1901 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 1902 if (err) 1903 goto journal_error; 1904 brelse(bh2); 1905 dxtrace(dx_show_index("frame", frame->entries)); 1906 return de; 1907 1908 journal_error: 1909 brelse(*bh); 1910 brelse(bh2); 1911 *bh = NULL; 1912 ext4_std_error(dir->i_sb, err); 1913 return ERR_PTR(err); 1914 } 1915 1916 int ext4_find_dest_de(struct inode *dir, struct inode *inode, 1917 struct buffer_head *bh, 1918 void *buf, int buf_size, 1919 struct ext4_filename *fname, 1920 struct ext4_dir_entry_2 **dest_de) 1921 { 1922 struct ext4_dir_entry_2 *de; 1923 unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname)); 1924 int nlen, rlen; 1925 unsigned int offset = 0; 1926 char *top; 1927 1928 de = (struct ext4_dir_entry_2 *)buf; 1929 top = buf + buf_size - reclen; 1930 while ((char *) de <= top) { 1931 if (ext4_check_dir_entry(dir, NULL, de, bh, 1932 buf, buf_size, offset)) 1933 return -EFSCORRUPTED; 1934 if (ext4_match(dir, fname, de)) 1935 return -EEXIST; 1936 nlen = EXT4_DIR_REC_LEN(de->name_len); 1937 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 1938 if ((de->inode ? rlen - nlen : rlen) >= reclen) 1939 break; 1940 de = (struct ext4_dir_entry_2 *)((char *)de + rlen); 1941 offset += rlen; 1942 } 1943 if ((char *) de > top) 1944 return -ENOSPC; 1945 1946 *dest_de = de; 1947 return 0; 1948 } 1949 1950 void ext4_insert_dentry(struct inode *inode, 1951 struct ext4_dir_entry_2 *de, 1952 int buf_size, 1953 struct ext4_filename *fname) 1954 { 1955 1956 int nlen, rlen; 1957 1958 nlen = EXT4_DIR_REC_LEN(de->name_len); 1959 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 1960 if (de->inode) { 1961 struct ext4_dir_entry_2 *de1 = 1962 (struct ext4_dir_entry_2 *)((char *)de + nlen); 1963 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size); 1964 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size); 1965 de = de1; 1966 } 1967 de->file_type = EXT4_FT_UNKNOWN; 1968 de->inode = cpu_to_le32(inode->i_ino); 1969 ext4_set_de_type(inode->i_sb, de, inode->i_mode); 1970 de->name_len = fname_len(fname); 1971 memcpy(de->name, fname_name(fname), fname_len(fname)); 1972 } 1973 1974 /* 1975 * Add a new entry into a directory (leaf) block. If de is non-NULL, 1976 * it points to a directory entry which is guaranteed to be large 1977 * enough for new directory entry. If de is NULL, then 1978 * add_dirent_to_buf will attempt search the directory block for 1979 * space. It will return -ENOSPC if no space is available, and -EIO 1980 * and -EEXIST if directory entry already exists. 1981 */ 1982 static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname, 1983 struct inode *dir, 1984 struct inode *inode, struct ext4_dir_entry_2 *de, 1985 struct buffer_head *bh) 1986 { 1987 unsigned int blocksize = dir->i_sb->s_blocksize; 1988 int csum_size = 0; 1989 int err; 1990 1991 if (ext4_has_metadata_csum(inode->i_sb)) 1992 csum_size = sizeof(struct ext4_dir_entry_tail); 1993 1994 if (!de) { 1995 err = ext4_find_dest_de(dir, inode, bh, bh->b_data, 1996 blocksize - csum_size, fname, &de); 1997 if (err) 1998 return err; 1999 } 2000 BUFFER_TRACE(bh, "get_write_access"); 2001 err = ext4_journal_get_write_access(handle, bh); 2002 if (err) { 2003 ext4_std_error(dir->i_sb, err); 2004 return err; 2005 } 2006 2007 /* By now the buffer is marked for journaling */ 2008 ext4_insert_dentry(inode, de, blocksize, fname); 2009 2010 /* 2011 * XXX shouldn't update any times until successful 2012 * completion of syscall, but too many callers depend 2013 * on this. 2014 * 2015 * XXX similarly, too many callers depend on 2016 * ext4_new_inode() setting the times, but error 2017 * recovery deletes the inode, so the worst that can 2018 * happen is that the times are slightly out of date 2019 * and/or different from the directory change time. 2020 */ 2021 dir->i_mtime = dir->i_ctime = current_time(dir); 2022 ext4_update_dx_flag(dir); 2023 inode_inc_iversion(dir); 2024 ext4_mark_inode_dirty(handle, dir); 2025 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); 2026 err = ext4_handle_dirty_dirblock(handle, dir, bh); 2027 if (err) 2028 ext4_std_error(dir->i_sb, err); 2029 return 0; 2030 } 2031 2032 /* 2033 * This converts a one block unindexed directory to a 3 block indexed 2034 * directory, and adds the dentry to the indexed directory. 2035 */ 2036 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname, 2037 struct inode *dir, 2038 struct inode *inode, struct buffer_head *bh) 2039 { 2040 struct buffer_head *bh2; 2041 struct dx_root *root; 2042 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 2043 struct dx_entry *entries; 2044 struct ext4_dir_entry_2 *de, *de2; 2045 char *data2, *top; 2046 unsigned len; 2047 int retval; 2048 unsigned blocksize; 2049 ext4_lblk_t block; 2050 struct fake_dirent *fde; 2051 int csum_size = 0; 2052 2053 if (ext4_has_metadata_csum(inode->i_sb)) 2054 csum_size = sizeof(struct ext4_dir_entry_tail); 2055 2056 blocksize = dir->i_sb->s_blocksize; 2057 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino)); 2058 BUFFER_TRACE(bh, "get_write_access"); 2059 retval = ext4_journal_get_write_access(handle, bh); 2060 if (retval) { 2061 ext4_std_error(dir->i_sb, retval); 2062 brelse(bh); 2063 return retval; 2064 } 2065 root = (struct dx_root *) bh->b_data; 2066 2067 /* The 0th block becomes the root, move the dirents out */ 2068 fde = &root->dotdot; 2069 de = (struct ext4_dir_entry_2 *)((char *)fde + 2070 ext4_rec_len_from_disk(fde->rec_len, blocksize)); 2071 if ((char *) de >= (((char *) root) + blocksize)) { 2072 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'"); 2073 brelse(bh); 2074 return -EFSCORRUPTED; 2075 } 2076 len = ((char *) root) + (blocksize - csum_size) - (char *) de; 2077 2078 /* Allocate new block for the 0th block's dirents */ 2079 bh2 = ext4_append(handle, dir, &block); 2080 if (IS_ERR(bh2)) { 2081 brelse(bh); 2082 return PTR_ERR(bh2); 2083 } 2084 ext4_set_inode_flag(dir, EXT4_INODE_INDEX); 2085 data2 = bh2->b_data; 2086 2087 memcpy(data2, de, len); 2088 de = (struct ext4_dir_entry_2 *) data2; 2089 top = data2 + len; 2090 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top) 2091 de = de2; 2092 de->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) - 2093 (char *) de, blocksize); 2094 2095 if (csum_size) 2096 ext4_initialize_dirent_tail(bh2, blocksize); 2097 2098 /* Initialize the root; the dot dirents already exist */ 2099 de = (struct ext4_dir_entry_2 *) (&root->dotdot); 2100 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2), 2101 blocksize); 2102 memset (&root->info, 0, sizeof(root->info)); 2103 root->info.info_length = sizeof(root->info); 2104 root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version; 2105 entries = root->entries; 2106 dx_set_block(entries, 1); 2107 dx_set_count(entries, 1); 2108 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info))); 2109 2110 /* Initialize as for dx_probe */ 2111 fname->hinfo.hash_version = root->info.hash_version; 2112 if (fname->hinfo.hash_version <= DX_HASH_TEA) 2113 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; 2114 fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; 2115 ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), &fname->hinfo); 2116 2117 memset(frames, 0, sizeof(frames)); 2118 frame = frames; 2119 frame->entries = entries; 2120 frame->at = entries; 2121 frame->bh = bh; 2122 2123 retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 2124 if (retval) 2125 goto out_frames; 2126 retval = ext4_handle_dirty_dirblock(handle, dir, bh2); 2127 if (retval) 2128 goto out_frames; 2129 2130 de = do_split(handle,dir, &bh2, frame, &fname->hinfo); 2131 if (IS_ERR(de)) { 2132 retval = PTR_ERR(de); 2133 goto out_frames; 2134 } 2135 2136 retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2); 2137 out_frames: 2138 /* 2139 * Even if the block split failed, we have to properly write 2140 * out all the changes we did so far. Otherwise we can end up 2141 * with corrupted filesystem. 2142 */ 2143 if (retval) 2144 ext4_mark_inode_dirty(handle, dir); 2145 dx_release(frames); 2146 brelse(bh2); 2147 return retval; 2148 } 2149 2150 /* 2151 * ext4_add_entry() 2152 * 2153 * adds a file entry to the specified directory, using the same 2154 * semantics as ext4_find_entry(). It returns NULL if it failed. 2155 * 2156 * NOTE!! The inode part of 'de' is left at 0 - which means you 2157 * may not sleep between calling this and putting something into 2158 * the entry, as someone else might have used it while you slept. 2159 */ 2160 static int ext4_add_entry(handle_t *handle, struct dentry *dentry, 2161 struct inode *inode) 2162 { 2163 struct inode *dir = d_inode(dentry->d_parent); 2164 struct buffer_head *bh = NULL; 2165 struct ext4_dir_entry_2 *de; 2166 struct super_block *sb; 2167 struct ext4_sb_info *sbi; 2168 struct ext4_filename fname; 2169 int retval; 2170 int dx_fallback=0; 2171 unsigned blocksize; 2172 ext4_lblk_t block, blocks; 2173 int csum_size = 0; 2174 2175 if (ext4_has_metadata_csum(inode->i_sb)) 2176 csum_size = sizeof(struct ext4_dir_entry_tail); 2177 2178 sb = dir->i_sb; 2179 sbi = EXT4_SB(sb); 2180 blocksize = sb->s_blocksize; 2181 if (!dentry->d_name.len) 2182 return -EINVAL; 2183 2184 #ifdef CONFIG_UNICODE 2185 if (ext4_has_strict_mode(sbi) && IS_CASEFOLDED(dir) && 2186 utf8_validate(sbi->s_encoding, &dentry->d_name)) 2187 return -EINVAL; 2188 #endif 2189 2190 retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname); 2191 if (retval) 2192 return retval; 2193 2194 if (ext4_has_inline_data(dir)) { 2195 retval = ext4_try_add_inline_entry(handle, &fname, dir, inode); 2196 if (retval < 0) 2197 goto out; 2198 if (retval == 1) { 2199 retval = 0; 2200 goto out; 2201 } 2202 } 2203 2204 if (is_dx(dir)) { 2205 retval = ext4_dx_add_entry(handle, &fname, dir, inode); 2206 if (!retval || (retval != ERR_BAD_DX_DIR)) 2207 goto out; 2208 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX); 2209 dx_fallback++; 2210 ext4_mark_inode_dirty(handle, dir); 2211 } 2212 blocks = dir->i_size >> sb->s_blocksize_bits; 2213 for (block = 0; block < blocks; block++) { 2214 bh = ext4_read_dirblock(dir, block, DIRENT); 2215 if (bh == NULL) { 2216 bh = ext4_bread(handle, dir, block, 2217 EXT4_GET_BLOCKS_CREATE); 2218 goto add_to_new_block; 2219 } 2220 if (IS_ERR(bh)) { 2221 retval = PTR_ERR(bh); 2222 bh = NULL; 2223 goto out; 2224 } 2225 retval = add_dirent_to_buf(handle, &fname, dir, inode, 2226 NULL, bh); 2227 if (retval != -ENOSPC) 2228 goto out; 2229 2230 if (blocks == 1 && !dx_fallback && 2231 ext4_has_feature_dir_index(sb)) { 2232 retval = make_indexed_dir(handle, &fname, dir, 2233 inode, bh); 2234 bh = NULL; /* make_indexed_dir releases bh */ 2235 goto out; 2236 } 2237 brelse(bh); 2238 } 2239 bh = ext4_append(handle, dir, &block); 2240 add_to_new_block: 2241 if (IS_ERR(bh)) { 2242 retval = PTR_ERR(bh); 2243 bh = NULL; 2244 goto out; 2245 } 2246 de = (struct ext4_dir_entry_2 *) bh->b_data; 2247 de->inode = 0; 2248 de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize); 2249 2250 if (csum_size) 2251 ext4_initialize_dirent_tail(bh, blocksize); 2252 2253 retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh); 2254 out: 2255 ext4_fname_free_filename(&fname); 2256 brelse(bh); 2257 if (retval == 0) 2258 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY); 2259 return retval; 2260 } 2261 2262 /* 2263 * Returns 0 for success, or a negative error value 2264 */ 2265 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname, 2266 struct inode *dir, struct inode *inode) 2267 { 2268 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 2269 struct dx_entry *entries, *at; 2270 struct buffer_head *bh; 2271 struct super_block *sb = dir->i_sb; 2272 struct ext4_dir_entry_2 *de; 2273 int restart; 2274 int err; 2275 2276 again: 2277 restart = 0; 2278 frame = dx_probe(fname, dir, NULL, frames); 2279 if (IS_ERR(frame)) 2280 return PTR_ERR(frame); 2281 entries = frame->entries; 2282 at = frame->at; 2283 bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT_HTREE); 2284 if (IS_ERR(bh)) { 2285 err = PTR_ERR(bh); 2286 bh = NULL; 2287 goto cleanup; 2288 } 2289 2290 BUFFER_TRACE(bh, "get_write_access"); 2291 err = ext4_journal_get_write_access(handle, bh); 2292 if (err) 2293 goto journal_error; 2294 2295 err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh); 2296 if (err != -ENOSPC) 2297 goto cleanup; 2298 2299 err = 0; 2300 /* Block full, should compress but for now just split */ 2301 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n", 2302 dx_get_count(entries), dx_get_limit(entries))); 2303 /* Need to split index? */ 2304 if (dx_get_count(entries) == dx_get_limit(entries)) { 2305 ext4_lblk_t newblock; 2306 int levels = frame - frames + 1; 2307 unsigned int icount; 2308 int add_level = 1; 2309 struct dx_entry *entries2; 2310 struct dx_node *node2; 2311 struct buffer_head *bh2; 2312 2313 while (frame > frames) { 2314 if (dx_get_count((frame - 1)->entries) < 2315 dx_get_limit((frame - 1)->entries)) { 2316 add_level = 0; 2317 break; 2318 } 2319 frame--; /* split higher index block */ 2320 at = frame->at; 2321 entries = frame->entries; 2322 restart = 1; 2323 } 2324 if (add_level && levels == ext4_dir_htree_level(sb)) { 2325 ext4_warning(sb, "Directory (ino: %lu) index full, " 2326 "reach max htree level :%d", 2327 dir->i_ino, levels); 2328 if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) { 2329 ext4_warning(sb, "Large directory feature is " 2330 "not enabled on this " 2331 "filesystem"); 2332 } 2333 err = -ENOSPC; 2334 goto cleanup; 2335 } 2336 icount = dx_get_count(entries); 2337 bh2 = ext4_append(handle, dir, &newblock); 2338 if (IS_ERR(bh2)) { 2339 err = PTR_ERR(bh2); 2340 goto cleanup; 2341 } 2342 node2 = (struct dx_node *)(bh2->b_data); 2343 entries2 = node2->entries; 2344 memset(&node2->fake, 0, sizeof(struct fake_dirent)); 2345 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize, 2346 sb->s_blocksize); 2347 BUFFER_TRACE(frame->bh, "get_write_access"); 2348 err = ext4_journal_get_write_access(handle, frame->bh); 2349 if (err) 2350 goto journal_error; 2351 if (!add_level) { 2352 unsigned icount1 = icount/2, icount2 = icount - icount1; 2353 unsigned hash2 = dx_get_hash(entries + icount1); 2354 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n", 2355 icount1, icount2)); 2356 2357 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */ 2358 err = ext4_journal_get_write_access(handle, 2359 (frame - 1)->bh); 2360 if (err) 2361 goto journal_error; 2362 2363 memcpy((char *) entries2, (char *) (entries + icount1), 2364 icount2 * sizeof(struct dx_entry)); 2365 dx_set_count(entries, icount1); 2366 dx_set_count(entries2, icount2); 2367 dx_set_limit(entries2, dx_node_limit(dir)); 2368 2369 /* Which index block gets the new entry? */ 2370 if (at - entries >= icount1) { 2371 frame->at = at = at - entries - icount1 + entries2; 2372 frame->entries = entries = entries2; 2373 swap(frame->bh, bh2); 2374 } 2375 dx_insert_block((frame - 1), hash2, newblock); 2376 dxtrace(dx_show_index("node", frame->entries)); 2377 dxtrace(dx_show_index("node", 2378 ((struct dx_node *) bh2->b_data)->entries)); 2379 err = ext4_handle_dirty_dx_node(handle, dir, bh2); 2380 if (err) 2381 goto journal_error; 2382 brelse (bh2); 2383 err = ext4_handle_dirty_dx_node(handle, dir, 2384 (frame - 1)->bh); 2385 if (err) 2386 goto journal_error; 2387 if (restart) { 2388 err = ext4_handle_dirty_dx_node(handle, dir, 2389 frame->bh); 2390 goto journal_error; 2391 } 2392 } else { 2393 struct dx_root *dxroot; 2394 memcpy((char *) entries2, (char *) entries, 2395 icount * sizeof(struct dx_entry)); 2396 dx_set_limit(entries2, dx_node_limit(dir)); 2397 2398 /* Set up root */ 2399 dx_set_count(entries, 1); 2400 dx_set_block(entries + 0, newblock); 2401 dxroot = (struct dx_root *)frames[0].bh->b_data; 2402 dxroot->info.indirect_levels += 1; 2403 dxtrace(printk(KERN_DEBUG 2404 "Creating %d level index...\n", 2405 dxroot->info.indirect_levels)); 2406 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 2407 if (err) 2408 goto journal_error; 2409 err = ext4_handle_dirty_dx_node(handle, dir, bh2); 2410 brelse(bh2); 2411 restart = 1; 2412 goto journal_error; 2413 } 2414 } 2415 de = do_split(handle, dir, &bh, frame, &fname->hinfo); 2416 if (IS_ERR(de)) { 2417 err = PTR_ERR(de); 2418 goto cleanup; 2419 } 2420 err = add_dirent_to_buf(handle, fname, dir, inode, de, bh); 2421 goto cleanup; 2422 2423 journal_error: 2424 ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */ 2425 cleanup: 2426 brelse(bh); 2427 dx_release(frames); 2428 /* @restart is true means htree-path has been changed, we need to 2429 * repeat dx_probe() to find out valid htree-path 2430 */ 2431 if (restart && err == 0) 2432 goto again; 2433 return err; 2434 } 2435 2436 /* 2437 * ext4_generic_delete_entry deletes a directory entry by merging it 2438 * with the previous entry 2439 */ 2440 int ext4_generic_delete_entry(handle_t *handle, 2441 struct inode *dir, 2442 struct ext4_dir_entry_2 *de_del, 2443 struct buffer_head *bh, 2444 void *entry_buf, 2445 int buf_size, 2446 int csum_size) 2447 { 2448 struct ext4_dir_entry_2 *de, *pde; 2449 unsigned int blocksize = dir->i_sb->s_blocksize; 2450 int i; 2451 2452 i = 0; 2453 pde = NULL; 2454 de = (struct ext4_dir_entry_2 *)entry_buf; 2455 while (i < buf_size - csum_size) { 2456 if (ext4_check_dir_entry(dir, NULL, de, bh, 2457 bh->b_data, bh->b_size, i)) 2458 return -EFSCORRUPTED; 2459 if (de == de_del) { 2460 if (pde) 2461 pde->rec_len = ext4_rec_len_to_disk( 2462 ext4_rec_len_from_disk(pde->rec_len, 2463 blocksize) + 2464 ext4_rec_len_from_disk(de->rec_len, 2465 blocksize), 2466 blocksize); 2467 else 2468 de->inode = 0; 2469 inode_inc_iversion(dir); 2470 return 0; 2471 } 2472 i += ext4_rec_len_from_disk(de->rec_len, blocksize); 2473 pde = de; 2474 de = ext4_next_entry(de, blocksize); 2475 } 2476 return -ENOENT; 2477 } 2478 2479 static int ext4_delete_entry(handle_t *handle, 2480 struct inode *dir, 2481 struct ext4_dir_entry_2 *de_del, 2482 struct buffer_head *bh) 2483 { 2484 int err, csum_size = 0; 2485 2486 if (ext4_has_inline_data(dir)) { 2487 int has_inline_data = 1; 2488 err = ext4_delete_inline_entry(handle, dir, de_del, bh, 2489 &has_inline_data); 2490 if (has_inline_data) 2491 return err; 2492 } 2493 2494 if (ext4_has_metadata_csum(dir->i_sb)) 2495 csum_size = sizeof(struct ext4_dir_entry_tail); 2496 2497 BUFFER_TRACE(bh, "get_write_access"); 2498 err = ext4_journal_get_write_access(handle, bh); 2499 if (unlikely(err)) 2500 goto out; 2501 2502 err = ext4_generic_delete_entry(handle, dir, de_del, 2503 bh, bh->b_data, 2504 dir->i_sb->s_blocksize, csum_size); 2505 if (err) 2506 goto out; 2507 2508 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); 2509 err = ext4_handle_dirty_dirblock(handle, dir, bh); 2510 if (unlikely(err)) 2511 goto out; 2512 2513 return 0; 2514 out: 2515 if (err != -ENOENT) 2516 ext4_std_error(dir->i_sb, err); 2517 return err; 2518 } 2519 2520 /* 2521 * Set directory link count to 1 if nlinks > EXT4_LINK_MAX, or if nlinks == 2 2522 * since this indicates that nlinks count was previously 1 to avoid overflowing 2523 * the 16-bit i_links_count field on disk. Directories with i_nlink == 1 mean 2524 * that subdirectory link counts are not being maintained accurately. 2525 * 2526 * The caller has already checked for i_nlink overflow in case the DIR_LINK 2527 * feature is not enabled and returned -EMLINK. The is_dx() check is a proxy 2528 * for checking S_ISDIR(inode) (since the INODE_INDEX feature will not be set 2529 * on regular files) and to avoid creating huge/slow non-HTREE directories. 2530 */ 2531 static void ext4_inc_count(handle_t *handle, struct inode *inode) 2532 { 2533 inc_nlink(inode); 2534 if (is_dx(inode) && 2535 (inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2)) 2536 set_nlink(inode, 1); 2537 } 2538 2539 /* 2540 * If a directory had nlink == 1, then we should let it be 1. This indicates 2541 * directory has >EXT4_LINK_MAX subdirs. 2542 */ 2543 static void ext4_dec_count(handle_t *handle, struct inode *inode) 2544 { 2545 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2) 2546 drop_nlink(inode); 2547 } 2548 2549 2550 static int ext4_add_nondir(handle_t *handle, 2551 struct dentry *dentry, struct inode *inode) 2552 { 2553 int err = ext4_add_entry(handle, dentry, inode); 2554 if (!err) { 2555 ext4_mark_inode_dirty(handle, inode); 2556 d_instantiate_new(dentry, inode); 2557 return 0; 2558 } 2559 drop_nlink(inode); 2560 unlock_new_inode(inode); 2561 iput(inode); 2562 return err; 2563 } 2564 2565 /* 2566 * By the time this is called, we already have created 2567 * the directory cache entry for the new file, but it 2568 * is so far negative - it has no inode. 2569 * 2570 * If the create succeeds, we fill in the inode information 2571 * with d_instantiate(). 2572 */ 2573 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode, 2574 bool excl) 2575 { 2576 handle_t *handle; 2577 struct inode *inode; 2578 int err, credits, retries = 0; 2579 2580 err = dquot_initialize(dir); 2581 if (err) 2582 return err; 2583 2584 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2585 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2586 retry: 2587 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0, 2588 NULL, EXT4_HT_DIR, credits); 2589 handle = ext4_journal_current_handle(); 2590 err = PTR_ERR(inode); 2591 if (!IS_ERR(inode)) { 2592 inode->i_op = &ext4_file_inode_operations; 2593 inode->i_fop = &ext4_file_operations; 2594 ext4_set_aops(inode); 2595 err = ext4_add_nondir(handle, dentry, inode); 2596 if (!err && IS_DIRSYNC(dir)) 2597 ext4_handle_sync(handle); 2598 } 2599 if (handle) 2600 ext4_journal_stop(handle); 2601 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2602 goto retry; 2603 return err; 2604 } 2605 2606 static int ext4_mknod(struct inode *dir, struct dentry *dentry, 2607 umode_t mode, dev_t rdev) 2608 { 2609 handle_t *handle; 2610 struct inode *inode; 2611 int err, credits, retries = 0; 2612 2613 err = dquot_initialize(dir); 2614 if (err) 2615 return err; 2616 2617 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2618 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2619 retry: 2620 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0, 2621 NULL, EXT4_HT_DIR, credits); 2622 handle = ext4_journal_current_handle(); 2623 err = PTR_ERR(inode); 2624 if (!IS_ERR(inode)) { 2625 init_special_inode(inode, inode->i_mode, rdev); 2626 inode->i_op = &ext4_special_inode_operations; 2627 err = ext4_add_nondir(handle, dentry, inode); 2628 if (!err && IS_DIRSYNC(dir)) 2629 ext4_handle_sync(handle); 2630 } 2631 if (handle) 2632 ext4_journal_stop(handle); 2633 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2634 goto retry; 2635 return err; 2636 } 2637 2638 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) 2639 { 2640 handle_t *handle; 2641 struct inode *inode; 2642 int err, retries = 0; 2643 2644 err = dquot_initialize(dir); 2645 if (err) 2646 return err; 2647 2648 retry: 2649 inode = ext4_new_inode_start_handle(dir, mode, 2650 NULL, 0, NULL, 2651 EXT4_HT_DIR, 2652 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) + 2653 4 + EXT4_XATTR_TRANS_BLOCKS); 2654 handle = ext4_journal_current_handle(); 2655 err = PTR_ERR(inode); 2656 if (!IS_ERR(inode)) { 2657 inode->i_op = &ext4_file_inode_operations; 2658 inode->i_fop = &ext4_file_operations; 2659 ext4_set_aops(inode); 2660 d_tmpfile(dentry, inode); 2661 err = ext4_orphan_add(handle, inode); 2662 if (err) 2663 goto err_unlock_inode; 2664 mark_inode_dirty(inode); 2665 unlock_new_inode(inode); 2666 } 2667 if (handle) 2668 ext4_journal_stop(handle); 2669 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2670 goto retry; 2671 return err; 2672 err_unlock_inode: 2673 ext4_journal_stop(handle); 2674 unlock_new_inode(inode); 2675 return err; 2676 } 2677 2678 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode, 2679 struct ext4_dir_entry_2 *de, 2680 int blocksize, int csum_size, 2681 unsigned int parent_ino, int dotdot_real_len) 2682 { 2683 de->inode = cpu_to_le32(inode->i_ino); 2684 de->name_len = 1; 2685 de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len), 2686 blocksize); 2687 strcpy(de->name, "."); 2688 ext4_set_de_type(inode->i_sb, de, S_IFDIR); 2689 2690 de = ext4_next_entry(de, blocksize); 2691 de->inode = cpu_to_le32(parent_ino); 2692 de->name_len = 2; 2693 if (!dotdot_real_len) 2694 de->rec_len = ext4_rec_len_to_disk(blocksize - 2695 (csum_size + EXT4_DIR_REC_LEN(1)), 2696 blocksize); 2697 else 2698 de->rec_len = ext4_rec_len_to_disk( 2699 EXT4_DIR_REC_LEN(de->name_len), blocksize); 2700 strcpy(de->name, ".."); 2701 ext4_set_de_type(inode->i_sb, de, S_IFDIR); 2702 2703 return ext4_next_entry(de, blocksize); 2704 } 2705 2706 static int ext4_init_new_dir(handle_t *handle, struct inode *dir, 2707 struct inode *inode) 2708 { 2709 struct buffer_head *dir_block = NULL; 2710 struct ext4_dir_entry_2 *de; 2711 ext4_lblk_t block = 0; 2712 unsigned int blocksize = dir->i_sb->s_blocksize; 2713 int csum_size = 0; 2714 int err; 2715 2716 if (ext4_has_metadata_csum(dir->i_sb)) 2717 csum_size = sizeof(struct ext4_dir_entry_tail); 2718 2719 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) { 2720 err = ext4_try_create_inline_dir(handle, dir, inode); 2721 if (err < 0 && err != -ENOSPC) 2722 goto out; 2723 if (!err) 2724 goto out; 2725 } 2726 2727 inode->i_size = 0; 2728 dir_block = ext4_append(handle, inode, &block); 2729 if (IS_ERR(dir_block)) 2730 return PTR_ERR(dir_block); 2731 de = (struct ext4_dir_entry_2 *)dir_block->b_data; 2732 ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0); 2733 set_nlink(inode, 2); 2734 if (csum_size) 2735 ext4_initialize_dirent_tail(dir_block, blocksize); 2736 2737 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata"); 2738 err = ext4_handle_dirty_dirblock(handle, inode, dir_block); 2739 if (err) 2740 goto out; 2741 set_buffer_verified(dir_block); 2742 out: 2743 brelse(dir_block); 2744 return err; 2745 } 2746 2747 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) 2748 { 2749 handle_t *handle; 2750 struct inode *inode; 2751 int err, credits, retries = 0; 2752 2753 if (EXT4_DIR_LINK_MAX(dir)) 2754 return -EMLINK; 2755 2756 err = dquot_initialize(dir); 2757 if (err) 2758 return err; 2759 2760 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2761 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2762 retry: 2763 inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode, 2764 &dentry->d_name, 2765 0, NULL, EXT4_HT_DIR, credits); 2766 handle = ext4_journal_current_handle(); 2767 err = PTR_ERR(inode); 2768 if (IS_ERR(inode)) 2769 goto out_stop; 2770 2771 inode->i_op = &ext4_dir_inode_operations; 2772 inode->i_fop = &ext4_dir_operations; 2773 err = ext4_init_new_dir(handle, dir, inode); 2774 if (err) 2775 goto out_clear_inode; 2776 err = ext4_mark_inode_dirty(handle, inode); 2777 if (!err) 2778 err = ext4_add_entry(handle, dentry, inode); 2779 if (err) { 2780 out_clear_inode: 2781 clear_nlink(inode); 2782 unlock_new_inode(inode); 2783 ext4_mark_inode_dirty(handle, inode); 2784 iput(inode); 2785 goto out_stop; 2786 } 2787 ext4_inc_count(handle, dir); 2788 ext4_update_dx_flag(dir); 2789 err = ext4_mark_inode_dirty(handle, dir); 2790 if (err) 2791 goto out_clear_inode; 2792 d_instantiate_new(dentry, inode); 2793 if (IS_DIRSYNC(dir)) 2794 ext4_handle_sync(handle); 2795 2796 out_stop: 2797 if (handle) 2798 ext4_journal_stop(handle); 2799 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2800 goto retry; 2801 return err; 2802 } 2803 2804 /* 2805 * routine to check that the specified directory is empty (for rmdir) 2806 */ 2807 bool ext4_empty_dir(struct inode *inode) 2808 { 2809 unsigned int offset; 2810 struct buffer_head *bh; 2811 struct ext4_dir_entry_2 *de, *de1; 2812 struct super_block *sb; 2813 2814 if (ext4_has_inline_data(inode)) { 2815 int has_inline_data = 1; 2816 int ret; 2817 2818 ret = empty_inline_dir(inode, &has_inline_data); 2819 if (has_inline_data) 2820 return ret; 2821 } 2822 2823 sb = inode->i_sb; 2824 if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) { 2825 EXT4_ERROR_INODE(inode, "invalid size"); 2826 return true; 2827 } 2828 /* The first directory block must not be a hole, 2829 * so treat it as DIRENT_HTREE 2830 */ 2831 bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE); 2832 if (IS_ERR(bh)) 2833 return true; 2834 2835 de = (struct ext4_dir_entry_2 *) bh->b_data; 2836 de1 = ext4_next_entry(de, sb->s_blocksize); 2837 if (le32_to_cpu(de->inode) != inode->i_ino || 2838 le32_to_cpu(de1->inode) == 0 || 2839 strcmp(".", de->name) || strcmp("..", de1->name)) { 2840 ext4_warning_inode(inode, "directory missing '.' and/or '..'"); 2841 brelse(bh); 2842 return true; 2843 } 2844 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) + 2845 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize); 2846 de = ext4_next_entry(de1, sb->s_blocksize); 2847 while (offset < inode->i_size) { 2848 if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) { 2849 unsigned int lblock; 2850 brelse(bh); 2851 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb); 2852 bh = ext4_read_dirblock(inode, lblock, EITHER); 2853 if (bh == NULL) { 2854 offset += sb->s_blocksize; 2855 continue; 2856 } 2857 if (IS_ERR(bh)) 2858 return true; 2859 de = (struct ext4_dir_entry_2 *) bh->b_data; 2860 } 2861 if (ext4_check_dir_entry(inode, NULL, de, bh, 2862 bh->b_data, bh->b_size, offset)) { 2863 de = (struct ext4_dir_entry_2 *)(bh->b_data + 2864 sb->s_blocksize); 2865 offset = (offset | (sb->s_blocksize - 1)) + 1; 2866 continue; 2867 } 2868 if (le32_to_cpu(de->inode)) { 2869 brelse(bh); 2870 return false; 2871 } 2872 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); 2873 de = ext4_next_entry(de, sb->s_blocksize); 2874 } 2875 brelse(bh); 2876 return true; 2877 } 2878 2879 /* 2880 * ext4_orphan_add() links an unlinked or truncated inode into a list of 2881 * such inodes, starting at the superblock, in case we crash before the 2882 * file is closed/deleted, or in case the inode truncate spans multiple 2883 * transactions and the last transaction is not recovered after a crash. 2884 * 2885 * At filesystem recovery time, we walk this list deleting unlinked 2886 * inodes and truncating linked inodes in ext4_orphan_cleanup(). 2887 * 2888 * Orphan list manipulation functions must be called under i_mutex unless 2889 * we are just creating the inode or deleting it. 2890 */ 2891 int ext4_orphan_add(handle_t *handle, struct inode *inode) 2892 { 2893 struct super_block *sb = inode->i_sb; 2894 struct ext4_sb_info *sbi = EXT4_SB(sb); 2895 struct ext4_iloc iloc; 2896 int err = 0, rc; 2897 bool dirty = false; 2898 2899 if (!sbi->s_journal || is_bad_inode(inode)) 2900 return 0; 2901 2902 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) && 2903 !inode_is_locked(inode)); 2904 /* 2905 * Exit early if inode already is on orphan list. This is a big speedup 2906 * since we don't have to contend on the global s_orphan_lock. 2907 */ 2908 if (!list_empty(&EXT4_I(inode)->i_orphan)) 2909 return 0; 2910 2911 /* 2912 * Orphan handling is only valid for files with data blocks 2913 * being truncated, or files being unlinked. Note that we either 2914 * hold i_mutex, or the inode can not be referenced from outside, 2915 * so i_nlink should not be bumped due to race 2916 */ 2917 J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 2918 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0); 2919 2920 BUFFER_TRACE(sbi->s_sbh, "get_write_access"); 2921 err = ext4_journal_get_write_access(handle, sbi->s_sbh); 2922 if (err) 2923 goto out; 2924 2925 err = ext4_reserve_inode_write(handle, inode, &iloc); 2926 if (err) 2927 goto out; 2928 2929 mutex_lock(&sbi->s_orphan_lock); 2930 /* 2931 * Due to previous errors inode may be already a part of on-disk 2932 * orphan list. If so skip on-disk list modification. 2933 */ 2934 if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) > 2935 (le32_to_cpu(sbi->s_es->s_inodes_count))) { 2936 /* Insert this inode at the head of the on-disk orphan list */ 2937 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan); 2938 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino); 2939 dirty = true; 2940 } 2941 list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan); 2942 mutex_unlock(&sbi->s_orphan_lock); 2943 2944 if (dirty) { 2945 err = ext4_handle_dirty_super(handle, sb); 2946 rc = ext4_mark_iloc_dirty(handle, inode, &iloc); 2947 if (!err) 2948 err = rc; 2949 if (err) { 2950 /* 2951 * We have to remove inode from in-memory list if 2952 * addition to on disk orphan list failed. Stray orphan 2953 * list entries can cause panics at unmount time. 2954 */ 2955 mutex_lock(&sbi->s_orphan_lock); 2956 list_del_init(&EXT4_I(inode)->i_orphan); 2957 mutex_unlock(&sbi->s_orphan_lock); 2958 } 2959 } else 2960 brelse(iloc.bh); 2961 2962 jbd_debug(4, "superblock will point to %lu\n", inode->i_ino); 2963 jbd_debug(4, "orphan inode %lu will point to %d\n", 2964 inode->i_ino, NEXT_ORPHAN(inode)); 2965 out: 2966 ext4_std_error(sb, err); 2967 return err; 2968 } 2969 2970 /* 2971 * ext4_orphan_del() removes an unlinked or truncated inode from the list 2972 * of such inodes stored on disk, because it is finally being cleaned up. 2973 */ 2974 int ext4_orphan_del(handle_t *handle, struct inode *inode) 2975 { 2976 struct list_head *prev; 2977 struct ext4_inode_info *ei = EXT4_I(inode); 2978 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 2979 __u32 ino_next; 2980 struct ext4_iloc iloc; 2981 int err = 0; 2982 2983 if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS)) 2984 return 0; 2985 2986 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) && 2987 !inode_is_locked(inode)); 2988 /* Do this quick check before taking global s_orphan_lock. */ 2989 if (list_empty(&ei->i_orphan)) 2990 return 0; 2991 2992 if (handle) { 2993 /* Grab inode buffer early before taking global s_orphan_lock */ 2994 err = ext4_reserve_inode_write(handle, inode, &iloc); 2995 } 2996 2997 mutex_lock(&sbi->s_orphan_lock); 2998 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino); 2999 3000 prev = ei->i_orphan.prev; 3001 list_del_init(&ei->i_orphan); 3002 3003 /* If we're on an error path, we may not have a valid 3004 * transaction handle with which to update the orphan list on 3005 * disk, but we still need to remove the inode from the linked 3006 * list in memory. */ 3007 if (!handle || err) { 3008 mutex_unlock(&sbi->s_orphan_lock); 3009 goto out_err; 3010 } 3011 3012 ino_next = NEXT_ORPHAN(inode); 3013 if (prev == &sbi->s_orphan) { 3014 jbd_debug(4, "superblock will point to %u\n", ino_next); 3015 BUFFER_TRACE(sbi->s_sbh, "get_write_access"); 3016 err = ext4_journal_get_write_access(handle, sbi->s_sbh); 3017 if (err) { 3018 mutex_unlock(&sbi->s_orphan_lock); 3019 goto out_brelse; 3020 } 3021 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next); 3022 mutex_unlock(&sbi->s_orphan_lock); 3023 err = ext4_handle_dirty_super(handle, inode->i_sb); 3024 } else { 3025 struct ext4_iloc iloc2; 3026 struct inode *i_prev = 3027 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode; 3028 3029 jbd_debug(4, "orphan inode %lu will point to %u\n", 3030 i_prev->i_ino, ino_next); 3031 err = ext4_reserve_inode_write(handle, i_prev, &iloc2); 3032 if (err) { 3033 mutex_unlock(&sbi->s_orphan_lock); 3034 goto out_brelse; 3035 } 3036 NEXT_ORPHAN(i_prev) = ino_next; 3037 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2); 3038 mutex_unlock(&sbi->s_orphan_lock); 3039 } 3040 if (err) 3041 goto out_brelse; 3042 NEXT_ORPHAN(inode) = 0; 3043 err = ext4_mark_iloc_dirty(handle, inode, &iloc); 3044 out_err: 3045 ext4_std_error(inode->i_sb, err); 3046 return err; 3047 3048 out_brelse: 3049 brelse(iloc.bh); 3050 goto out_err; 3051 } 3052 3053 static int ext4_rmdir(struct inode *dir, struct dentry *dentry) 3054 { 3055 int retval; 3056 struct inode *inode; 3057 struct buffer_head *bh; 3058 struct ext4_dir_entry_2 *de; 3059 handle_t *handle = NULL; 3060 3061 if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb)))) 3062 return -EIO; 3063 3064 /* Initialize quotas before so that eventual writes go in 3065 * separate transaction */ 3066 retval = dquot_initialize(dir); 3067 if (retval) 3068 return retval; 3069 retval = dquot_initialize(d_inode(dentry)); 3070 if (retval) 3071 return retval; 3072 3073 retval = -ENOENT; 3074 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); 3075 if (IS_ERR(bh)) 3076 return PTR_ERR(bh); 3077 if (!bh) 3078 goto end_rmdir; 3079 3080 inode = d_inode(dentry); 3081 3082 retval = -EFSCORRUPTED; 3083 if (le32_to_cpu(de->inode) != inode->i_ino) 3084 goto end_rmdir; 3085 3086 retval = -ENOTEMPTY; 3087 if (!ext4_empty_dir(inode)) 3088 goto end_rmdir; 3089 3090 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3091 EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); 3092 if (IS_ERR(handle)) { 3093 retval = PTR_ERR(handle); 3094 handle = NULL; 3095 goto end_rmdir; 3096 } 3097 3098 if (IS_DIRSYNC(dir)) 3099 ext4_handle_sync(handle); 3100 3101 retval = ext4_delete_entry(handle, dir, de, bh); 3102 if (retval) 3103 goto end_rmdir; 3104 if (!EXT4_DIR_LINK_EMPTY(inode)) 3105 ext4_warning_inode(inode, 3106 "empty directory '%.*s' has too many links (%u)", 3107 dentry->d_name.len, dentry->d_name.name, 3108 inode->i_nlink); 3109 inode_inc_iversion(inode); 3110 clear_nlink(inode); 3111 /* There's no need to set i_disksize: the fact that i_nlink is 3112 * zero will ensure that the right thing happens during any 3113 * recovery. */ 3114 inode->i_size = 0; 3115 ext4_orphan_add(handle, inode); 3116 inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode); 3117 ext4_mark_inode_dirty(handle, inode); 3118 ext4_dec_count(handle, dir); 3119 ext4_update_dx_flag(dir); 3120 ext4_mark_inode_dirty(handle, dir); 3121 3122 #ifdef CONFIG_UNICODE 3123 /* VFS negative dentries are incompatible with Encoding and 3124 * Case-insensitiveness. Eventually we'll want avoid 3125 * invalidating the dentries here, alongside with returning the 3126 * negative dentries at ext4_lookup(), when it is better 3127 * supported by the VFS for the CI case. 3128 */ 3129 if (IS_CASEFOLDED(dir)) 3130 d_invalidate(dentry); 3131 #endif 3132 3133 end_rmdir: 3134 brelse(bh); 3135 if (handle) 3136 ext4_journal_stop(handle); 3137 return retval; 3138 } 3139 3140 static int ext4_unlink(struct inode *dir, struct dentry *dentry) 3141 { 3142 int retval; 3143 struct inode *inode; 3144 struct buffer_head *bh; 3145 struct ext4_dir_entry_2 *de; 3146 handle_t *handle = NULL; 3147 3148 if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb)))) 3149 return -EIO; 3150 3151 trace_ext4_unlink_enter(dir, dentry); 3152 /* Initialize quotas before so that eventual writes go 3153 * in separate transaction */ 3154 retval = dquot_initialize(dir); 3155 if (retval) 3156 return retval; 3157 retval = dquot_initialize(d_inode(dentry)); 3158 if (retval) 3159 return retval; 3160 3161 retval = -ENOENT; 3162 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); 3163 if (IS_ERR(bh)) 3164 return PTR_ERR(bh); 3165 if (!bh) 3166 goto end_unlink; 3167 3168 inode = d_inode(dentry); 3169 3170 retval = -EFSCORRUPTED; 3171 if (le32_to_cpu(de->inode) != inode->i_ino) 3172 goto end_unlink; 3173 3174 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3175 EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); 3176 if (IS_ERR(handle)) { 3177 retval = PTR_ERR(handle); 3178 handle = NULL; 3179 goto end_unlink; 3180 } 3181 3182 if (IS_DIRSYNC(dir)) 3183 ext4_handle_sync(handle); 3184 3185 if (inode->i_nlink == 0) { 3186 ext4_warning_inode(inode, "Deleting file '%.*s' with no links", 3187 dentry->d_name.len, dentry->d_name.name); 3188 set_nlink(inode, 1); 3189 } 3190 retval = ext4_delete_entry(handle, dir, de, bh); 3191 if (retval) 3192 goto end_unlink; 3193 dir->i_ctime = dir->i_mtime = current_time(dir); 3194 ext4_update_dx_flag(dir); 3195 ext4_mark_inode_dirty(handle, dir); 3196 drop_nlink(inode); 3197 if (!inode->i_nlink) 3198 ext4_orphan_add(handle, inode); 3199 inode->i_ctime = current_time(inode); 3200 ext4_mark_inode_dirty(handle, inode); 3201 3202 #ifdef CONFIG_UNICODE 3203 /* VFS negative dentries are incompatible with Encoding and 3204 * Case-insensitiveness. Eventually we'll want avoid 3205 * invalidating the dentries here, alongside with returning the 3206 * negative dentries at ext4_lookup(), when it is better 3207 * supported by the VFS for the CI case. 3208 */ 3209 if (IS_CASEFOLDED(dir)) 3210 d_invalidate(dentry); 3211 #endif 3212 3213 end_unlink: 3214 brelse(bh); 3215 if (handle) 3216 ext4_journal_stop(handle); 3217 trace_ext4_unlink_exit(dentry, retval); 3218 return retval; 3219 } 3220 3221 static int ext4_symlink(struct inode *dir, 3222 struct dentry *dentry, const char *symname) 3223 { 3224 handle_t *handle; 3225 struct inode *inode; 3226 int err, len = strlen(symname); 3227 int credits; 3228 struct fscrypt_str disk_link; 3229 3230 if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb)))) 3231 return -EIO; 3232 3233 err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize, 3234 &disk_link); 3235 if (err) 3236 return err; 3237 3238 err = dquot_initialize(dir); 3239 if (err) 3240 return err; 3241 3242 if ((disk_link.len > EXT4_N_BLOCKS * 4)) { 3243 /* 3244 * For non-fast symlinks, we just allocate inode and put it on 3245 * orphan list in the first transaction => we need bitmap, 3246 * group descriptor, sb, inode block, quota blocks, and 3247 * possibly selinux xattr blocks. 3248 */ 3249 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) + 3250 EXT4_XATTR_TRANS_BLOCKS; 3251 } else { 3252 /* 3253 * Fast symlink. We have to add entry to directory 3254 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS), 3255 * allocate new inode (bitmap, group descriptor, inode block, 3256 * quota blocks, sb is already counted in previous macros). 3257 */ 3258 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3259 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3; 3260 } 3261 3262 inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO, 3263 &dentry->d_name, 0, NULL, 3264 EXT4_HT_DIR, credits); 3265 handle = ext4_journal_current_handle(); 3266 if (IS_ERR(inode)) { 3267 if (handle) 3268 ext4_journal_stop(handle); 3269 return PTR_ERR(inode); 3270 } 3271 3272 if (IS_ENCRYPTED(inode)) { 3273 err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link); 3274 if (err) 3275 goto err_drop_inode; 3276 inode->i_op = &ext4_encrypted_symlink_inode_operations; 3277 } 3278 3279 if ((disk_link.len > EXT4_N_BLOCKS * 4)) { 3280 if (!IS_ENCRYPTED(inode)) 3281 inode->i_op = &ext4_symlink_inode_operations; 3282 inode_nohighmem(inode); 3283 ext4_set_aops(inode); 3284 /* 3285 * We cannot call page_symlink() with transaction started 3286 * because it calls into ext4_write_begin() which can wait 3287 * for transaction commit if we are running out of space 3288 * and thus we deadlock. So we have to stop transaction now 3289 * and restart it when symlink contents is written. 3290 * 3291 * To keep fs consistent in case of crash, we have to put inode 3292 * to orphan list in the mean time. 3293 */ 3294 drop_nlink(inode); 3295 err = ext4_orphan_add(handle, inode); 3296 ext4_journal_stop(handle); 3297 handle = NULL; 3298 if (err) 3299 goto err_drop_inode; 3300 err = __page_symlink(inode, disk_link.name, disk_link.len, 1); 3301 if (err) 3302 goto err_drop_inode; 3303 /* 3304 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS 3305 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified 3306 */ 3307 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3308 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3309 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1); 3310 if (IS_ERR(handle)) { 3311 err = PTR_ERR(handle); 3312 handle = NULL; 3313 goto err_drop_inode; 3314 } 3315 set_nlink(inode, 1); 3316 err = ext4_orphan_del(handle, inode); 3317 if (err) 3318 goto err_drop_inode; 3319 } else { 3320 /* clear the extent format for fast symlink */ 3321 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS); 3322 if (!IS_ENCRYPTED(inode)) { 3323 inode->i_op = &ext4_fast_symlink_inode_operations; 3324 inode->i_link = (char *)&EXT4_I(inode)->i_data; 3325 } 3326 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name, 3327 disk_link.len); 3328 inode->i_size = disk_link.len - 1; 3329 } 3330 EXT4_I(inode)->i_disksize = inode->i_size; 3331 err = ext4_add_nondir(handle, dentry, inode); 3332 if (!err && IS_DIRSYNC(dir)) 3333 ext4_handle_sync(handle); 3334 3335 if (handle) 3336 ext4_journal_stop(handle); 3337 goto out_free_encrypted_link; 3338 3339 err_drop_inode: 3340 if (handle) 3341 ext4_journal_stop(handle); 3342 clear_nlink(inode); 3343 unlock_new_inode(inode); 3344 iput(inode); 3345 out_free_encrypted_link: 3346 if (disk_link.name != (unsigned char *)symname) 3347 kfree(disk_link.name); 3348 return err; 3349 } 3350 3351 static int ext4_link(struct dentry *old_dentry, 3352 struct inode *dir, struct dentry *dentry) 3353 { 3354 handle_t *handle; 3355 struct inode *inode = d_inode(old_dentry); 3356 int err, retries = 0; 3357 3358 if (inode->i_nlink >= EXT4_LINK_MAX) 3359 return -EMLINK; 3360 3361 err = fscrypt_prepare_link(old_dentry, dir, dentry); 3362 if (err) 3363 return err; 3364 3365 if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) && 3366 (!projid_eq(EXT4_I(dir)->i_projid, 3367 EXT4_I(old_dentry->d_inode)->i_projid))) 3368 return -EXDEV; 3369 3370 err = dquot_initialize(dir); 3371 if (err) 3372 return err; 3373 3374 retry: 3375 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3376 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3377 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1); 3378 if (IS_ERR(handle)) 3379 return PTR_ERR(handle); 3380 3381 if (IS_DIRSYNC(dir)) 3382 ext4_handle_sync(handle); 3383 3384 inode->i_ctime = current_time(inode); 3385 ext4_inc_count(handle, inode); 3386 ihold(inode); 3387 3388 err = ext4_add_entry(handle, dentry, inode); 3389 if (!err) { 3390 ext4_mark_inode_dirty(handle, inode); 3391 /* this can happen only for tmpfile being 3392 * linked the first time 3393 */ 3394 if (inode->i_nlink == 1) 3395 ext4_orphan_del(handle, inode); 3396 d_instantiate(dentry, inode); 3397 } else { 3398 drop_nlink(inode); 3399 iput(inode); 3400 } 3401 ext4_journal_stop(handle); 3402 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 3403 goto retry; 3404 return err; 3405 } 3406 3407 3408 /* 3409 * Try to find buffer head where contains the parent block. 3410 * It should be the inode block if it is inlined or the 1st block 3411 * if it is a normal dir. 3412 */ 3413 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle, 3414 struct inode *inode, 3415 int *retval, 3416 struct ext4_dir_entry_2 **parent_de, 3417 int *inlined) 3418 { 3419 struct buffer_head *bh; 3420 3421 if (!ext4_has_inline_data(inode)) { 3422 /* The first directory block must not be a hole, so 3423 * treat it as DIRENT_HTREE 3424 */ 3425 bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE); 3426 if (IS_ERR(bh)) { 3427 *retval = PTR_ERR(bh); 3428 return NULL; 3429 } 3430 *parent_de = ext4_next_entry( 3431 (struct ext4_dir_entry_2 *)bh->b_data, 3432 inode->i_sb->s_blocksize); 3433 return bh; 3434 } 3435 3436 *inlined = 1; 3437 return ext4_get_first_inline_block(inode, parent_de, retval); 3438 } 3439 3440 struct ext4_renament { 3441 struct inode *dir; 3442 struct dentry *dentry; 3443 struct inode *inode; 3444 bool is_dir; 3445 int dir_nlink_delta; 3446 3447 /* entry for "dentry" */ 3448 struct buffer_head *bh; 3449 struct ext4_dir_entry_2 *de; 3450 int inlined; 3451 3452 /* entry for ".." in inode if it's a directory */ 3453 struct buffer_head *dir_bh; 3454 struct ext4_dir_entry_2 *parent_de; 3455 int dir_inlined; 3456 }; 3457 3458 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent) 3459 { 3460 int retval; 3461 3462 ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode, 3463 &retval, &ent->parent_de, 3464 &ent->dir_inlined); 3465 if (!ent->dir_bh) 3466 return retval; 3467 if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino) 3468 return -EFSCORRUPTED; 3469 BUFFER_TRACE(ent->dir_bh, "get_write_access"); 3470 return ext4_journal_get_write_access(handle, ent->dir_bh); 3471 } 3472 3473 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent, 3474 unsigned dir_ino) 3475 { 3476 int retval; 3477 3478 ent->parent_de->inode = cpu_to_le32(dir_ino); 3479 BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata"); 3480 if (!ent->dir_inlined) { 3481 if (is_dx(ent->inode)) { 3482 retval = ext4_handle_dirty_dx_node(handle, 3483 ent->inode, 3484 ent->dir_bh); 3485 } else { 3486 retval = ext4_handle_dirty_dirblock(handle, ent->inode, 3487 ent->dir_bh); 3488 } 3489 } else { 3490 retval = ext4_mark_inode_dirty(handle, ent->inode); 3491 } 3492 if (retval) { 3493 ext4_std_error(ent->dir->i_sb, retval); 3494 return retval; 3495 } 3496 return 0; 3497 } 3498 3499 static int ext4_setent(handle_t *handle, struct ext4_renament *ent, 3500 unsigned ino, unsigned file_type) 3501 { 3502 int retval; 3503 3504 BUFFER_TRACE(ent->bh, "get write access"); 3505 retval = ext4_journal_get_write_access(handle, ent->bh); 3506 if (retval) 3507 return retval; 3508 ent->de->inode = cpu_to_le32(ino); 3509 if (ext4_has_feature_filetype(ent->dir->i_sb)) 3510 ent->de->file_type = file_type; 3511 inode_inc_iversion(ent->dir); 3512 ent->dir->i_ctime = ent->dir->i_mtime = 3513 current_time(ent->dir); 3514 ext4_mark_inode_dirty(handle, ent->dir); 3515 BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata"); 3516 if (!ent->inlined) { 3517 retval = ext4_handle_dirty_dirblock(handle, ent->dir, ent->bh); 3518 if (unlikely(retval)) { 3519 ext4_std_error(ent->dir->i_sb, retval); 3520 return retval; 3521 } 3522 } 3523 brelse(ent->bh); 3524 ent->bh = NULL; 3525 3526 return 0; 3527 } 3528 3529 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir, 3530 const struct qstr *d_name) 3531 { 3532 int retval = -ENOENT; 3533 struct buffer_head *bh; 3534 struct ext4_dir_entry_2 *de; 3535 3536 bh = ext4_find_entry(dir, d_name, &de, NULL); 3537 if (IS_ERR(bh)) 3538 return PTR_ERR(bh); 3539 if (bh) { 3540 retval = ext4_delete_entry(handle, dir, de, bh); 3541 brelse(bh); 3542 } 3543 return retval; 3544 } 3545 3546 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent, 3547 int force_reread) 3548 { 3549 int retval; 3550 /* 3551 * ent->de could have moved from under us during htree split, so make 3552 * sure that we are deleting the right entry. We might also be pointing 3553 * to a stale entry in the unused part of ent->bh so just checking inum 3554 * and the name isn't enough. 3555 */ 3556 if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino || 3557 ent->de->name_len != ent->dentry->d_name.len || 3558 strncmp(ent->de->name, ent->dentry->d_name.name, 3559 ent->de->name_len) || 3560 force_reread) { 3561 retval = ext4_find_delete_entry(handle, ent->dir, 3562 &ent->dentry->d_name); 3563 } else { 3564 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh); 3565 if (retval == -ENOENT) { 3566 retval = ext4_find_delete_entry(handle, ent->dir, 3567 &ent->dentry->d_name); 3568 } 3569 } 3570 3571 if (retval) { 3572 ext4_warning_inode(ent->dir, 3573 "Deleting old file: nlink %d, error=%d", 3574 ent->dir->i_nlink, retval); 3575 } 3576 } 3577 3578 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent) 3579 { 3580 if (ent->dir_nlink_delta) { 3581 if (ent->dir_nlink_delta == -1) 3582 ext4_dec_count(handle, ent->dir); 3583 else 3584 ext4_inc_count(handle, ent->dir); 3585 ext4_mark_inode_dirty(handle, ent->dir); 3586 } 3587 } 3588 3589 static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent, 3590 int credits, handle_t **h) 3591 { 3592 struct inode *wh; 3593 handle_t *handle; 3594 int retries = 0; 3595 3596 /* 3597 * for inode block, sb block, group summaries, 3598 * and inode bitmap 3599 */ 3600 credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) + 3601 EXT4_XATTR_TRANS_BLOCKS + 4); 3602 retry: 3603 wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE, 3604 &ent->dentry->d_name, 0, NULL, 3605 EXT4_HT_DIR, credits); 3606 3607 handle = ext4_journal_current_handle(); 3608 if (IS_ERR(wh)) { 3609 if (handle) 3610 ext4_journal_stop(handle); 3611 if (PTR_ERR(wh) == -ENOSPC && 3612 ext4_should_retry_alloc(ent->dir->i_sb, &retries)) 3613 goto retry; 3614 } else { 3615 *h = handle; 3616 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV); 3617 wh->i_op = &ext4_special_inode_operations; 3618 } 3619 return wh; 3620 } 3621 3622 /* 3623 * Anybody can rename anything with this: the permission checks are left to the 3624 * higher-level routines. 3625 * 3626 * n.b. old_{dentry,inode) refers to the source dentry/inode 3627 * while new_{dentry,inode) refers to the destination dentry/inode 3628 * This comes from rename(const char *oldpath, const char *newpath) 3629 */ 3630 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry, 3631 struct inode *new_dir, struct dentry *new_dentry, 3632 unsigned int flags) 3633 { 3634 handle_t *handle = NULL; 3635 struct ext4_renament old = { 3636 .dir = old_dir, 3637 .dentry = old_dentry, 3638 .inode = d_inode(old_dentry), 3639 }; 3640 struct ext4_renament new = { 3641 .dir = new_dir, 3642 .dentry = new_dentry, 3643 .inode = d_inode(new_dentry), 3644 }; 3645 int force_reread; 3646 int retval; 3647 struct inode *whiteout = NULL; 3648 int credits; 3649 u8 old_file_type; 3650 3651 if (new.inode && new.inode->i_nlink == 0) { 3652 EXT4_ERROR_INODE(new.inode, 3653 "target of rename is already freed"); 3654 return -EFSCORRUPTED; 3655 } 3656 3657 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) && 3658 (!projid_eq(EXT4_I(new_dir)->i_projid, 3659 EXT4_I(old_dentry->d_inode)->i_projid))) 3660 return -EXDEV; 3661 3662 retval = dquot_initialize(old.dir); 3663 if (retval) 3664 return retval; 3665 retval = dquot_initialize(new.dir); 3666 if (retval) 3667 return retval; 3668 3669 /* Initialize quotas before so that eventual writes go 3670 * in separate transaction */ 3671 if (new.inode) { 3672 retval = dquot_initialize(new.inode); 3673 if (retval) 3674 return retval; 3675 } 3676 3677 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL); 3678 if (IS_ERR(old.bh)) 3679 return PTR_ERR(old.bh); 3680 /* 3681 * Check for inode number is _not_ due to possible IO errors. 3682 * We might rmdir the source, keep it as pwd of some process 3683 * and merrily kill the link to whatever was created under the 3684 * same name. Goodbye sticky bit ;-< 3685 */ 3686 retval = -ENOENT; 3687 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino) 3688 goto end_rename; 3689 3690 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, 3691 &new.de, &new.inlined); 3692 if (IS_ERR(new.bh)) { 3693 retval = PTR_ERR(new.bh); 3694 new.bh = NULL; 3695 goto end_rename; 3696 } 3697 if (new.bh) { 3698 if (!new.inode) { 3699 brelse(new.bh); 3700 new.bh = NULL; 3701 } 3702 } 3703 if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC)) 3704 ext4_alloc_da_blocks(old.inode); 3705 3706 credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + 3707 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2); 3708 if (!(flags & RENAME_WHITEOUT)) { 3709 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits); 3710 if (IS_ERR(handle)) { 3711 retval = PTR_ERR(handle); 3712 handle = NULL; 3713 goto end_rename; 3714 } 3715 } else { 3716 whiteout = ext4_whiteout_for_rename(&old, credits, &handle); 3717 if (IS_ERR(whiteout)) { 3718 retval = PTR_ERR(whiteout); 3719 whiteout = NULL; 3720 goto end_rename; 3721 } 3722 } 3723 3724 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir)) 3725 ext4_handle_sync(handle); 3726 3727 if (S_ISDIR(old.inode->i_mode)) { 3728 if (new.inode) { 3729 retval = -ENOTEMPTY; 3730 if (!ext4_empty_dir(new.inode)) 3731 goto end_rename; 3732 } else { 3733 retval = -EMLINK; 3734 if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir)) 3735 goto end_rename; 3736 } 3737 retval = ext4_rename_dir_prepare(handle, &old); 3738 if (retval) 3739 goto end_rename; 3740 } 3741 /* 3742 * If we're renaming a file within an inline_data dir and adding or 3743 * setting the new dirent causes a conversion from inline_data to 3744 * extents/blockmap, we need to force the dirent delete code to 3745 * re-read the directory, or else we end up trying to delete a dirent 3746 * from what is now the extent tree root (or a block map). 3747 */ 3748 force_reread = (new.dir->i_ino == old.dir->i_ino && 3749 ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA)); 3750 3751 old_file_type = old.de->file_type; 3752 if (whiteout) { 3753 /* 3754 * Do this before adding a new entry, so the old entry is sure 3755 * to be still pointing to the valid old entry. 3756 */ 3757 retval = ext4_setent(handle, &old, whiteout->i_ino, 3758 EXT4_FT_CHRDEV); 3759 if (retval) 3760 goto end_rename; 3761 ext4_mark_inode_dirty(handle, whiteout); 3762 } 3763 if (!new.bh) { 3764 retval = ext4_add_entry(handle, new.dentry, old.inode); 3765 if (retval) 3766 goto end_rename; 3767 } else { 3768 retval = ext4_setent(handle, &new, 3769 old.inode->i_ino, old_file_type); 3770 if (retval) 3771 goto end_rename; 3772 } 3773 if (force_reread) 3774 force_reread = !ext4_test_inode_flag(new.dir, 3775 EXT4_INODE_INLINE_DATA); 3776 3777 /* 3778 * Like most other Unix systems, set the ctime for inodes on a 3779 * rename. 3780 */ 3781 old.inode->i_ctime = current_time(old.inode); 3782 ext4_mark_inode_dirty(handle, old.inode); 3783 3784 if (!whiteout) { 3785 /* 3786 * ok, that's it 3787 */ 3788 ext4_rename_delete(handle, &old, force_reread); 3789 } 3790 3791 if (new.inode) { 3792 ext4_dec_count(handle, new.inode); 3793 new.inode->i_ctime = current_time(new.inode); 3794 } 3795 old.dir->i_ctime = old.dir->i_mtime = current_time(old.dir); 3796 ext4_update_dx_flag(old.dir); 3797 if (old.dir_bh) { 3798 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); 3799 if (retval) 3800 goto end_rename; 3801 3802 ext4_dec_count(handle, old.dir); 3803 if (new.inode) { 3804 /* checked ext4_empty_dir above, can't have another 3805 * parent, ext4_dec_count() won't work for many-linked 3806 * dirs */ 3807 clear_nlink(new.inode); 3808 } else { 3809 ext4_inc_count(handle, new.dir); 3810 ext4_update_dx_flag(new.dir); 3811 ext4_mark_inode_dirty(handle, new.dir); 3812 } 3813 } 3814 ext4_mark_inode_dirty(handle, old.dir); 3815 if (new.inode) { 3816 ext4_mark_inode_dirty(handle, new.inode); 3817 if (!new.inode->i_nlink) 3818 ext4_orphan_add(handle, new.inode); 3819 } 3820 retval = 0; 3821 3822 end_rename: 3823 brelse(old.dir_bh); 3824 brelse(old.bh); 3825 brelse(new.bh); 3826 if (whiteout) { 3827 if (retval) 3828 drop_nlink(whiteout); 3829 unlock_new_inode(whiteout); 3830 iput(whiteout); 3831 } 3832 if (handle) 3833 ext4_journal_stop(handle); 3834 return retval; 3835 } 3836 3837 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry, 3838 struct inode *new_dir, struct dentry *new_dentry) 3839 { 3840 handle_t *handle = NULL; 3841 struct ext4_renament old = { 3842 .dir = old_dir, 3843 .dentry = old_dentry, 3844 .inode = d_inode(old_dentry), 3845 }; 3846 struct ext4_renament new = { 3847 .dir = new_dir, 3848 .dentry = new_dentry, 3849 .inode = d_inode(new_dentry), 3850 }; 3851 u8 new_file_type; 3852 int retval; 3853 struct timespec64 ctime; 3854 3855 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) && 3856 !projid_eq(EXT4_I(new_dir)->i_projid, 3857 EXT4_I(old_dentry->d_inode)->i_projid)) || 3858 (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) && 3859 !projid_eq(EXT4_I(old_dir)->i_projid, 3860 EXT4_I(new_dentry->d_inode)->i_projid))) 3861 return -EXDEV; 3862 3863 retval = dquot_initialize(old.dir); 3864 if (retval) 3865 return retval; 3866 retval = dquot_initialize(new.dir); 3867 if (retval) 3868 return retval; 3869 3870 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, 3871 &old.de, &old.inlined); 3872 if (IS_ERR(old.bh)) 3873 return PTR_ERR(old.bh); 3874 /* 3875 * Check for inode number is _not_ due to possible IO errors. 3876 * We might rmdir the source, keep it as pwd of some process 3877 * and merrily kill the link to whatever was created under the 3878 * same name. Goodbye sticky bit ;-< 3879 */ 3880 retval = -ENOENT; 3881 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino) 3882 goto end_rename; 3883 3884 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, 3885 &new.de, &new.inlined); 3886 if (IS_ERR(new.bh)) { 3887 retval = PTR_ERR(new.bh); 3888 new.bh = NULL; 3889 goto end_rename; 3890 } 3891 3892 /* RENAME_EXCHANGE case: old *and* new must both exist */ 3893 if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino) 3894 goto end_rename; 3895 3896 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, 3897 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + 3898 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2)); 3899 if (IS_ERR(handle)) { 3900 retval = PTR_ERR(handle); 3901 handle = NULL; 3902 goto end_rename; 3903 } 3904 3905 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir)) 3906 ext4_handle_sync(handle); 3907 3908 if (S_ISDIR(old.inode->i_mode)) { 3909 old.is_dir = true; 3910 retval = ext4_rename_dir_prepare(handle, &old); 3911 if (retval) 3912 goto end_rename; 3913 } 3914 if (S_ISDIR(new.inode->i_mode)) { 3915 new.is_dir = true; 3916 retval = ext4_rename_dir_prepare(handle, &new); 3917 if (retval) 3918 goto end_rename; 3919 } 3920 3921 /* 3922 * Other than the special case of overwriting a directory, parents' 3923 * nlink only needs to be modified if this is a cross directory rename. 3924 */ 3925 if (old.dir != new.dir && old.is_dir != new.is_dir) { 3926 old.dir_nlink_delta = old.is_dir ? -1 : 1; 3927 new.dir_nlink_delta = -old.dir_nlink_delta; 3928 retval = -EMLINK; 3929 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) || 3930 (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir))) 3931 goto end_rename; 3932 } 3933 3934 new_file_type = new.de->file_type; 3935 retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type); 3936 if (retval) 3937 goto end_rename; 3938 3939 retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type); 3940 if (retval) 3941 goto end_rename; 3942 3943 /* 3944 * Like most other Unix systems, set the ctime for inodes on a 3945 * rename. 3946 */ 3947 ctime = current_time(old.inode); 3948 old.inode->i_ctime = ctime; 3949 new.inode->i_ctime = ctime; 3950 ext4_mark_inode_dirty(handle, old.inode); 3951 ext4_mark_inode_dirty(handle, new.inode); 3952 3953 if (old.dir_bh) { 3954 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); 3955 if (retval) 3956 goto end_rename; 3957 } 3958 if (new.dir_bh) { 3959 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino); 3960 if (retval) 3961 goto end_rename; 3962 } 3963 ext4_update_dir_count(handle, &old); 3964 ext4_update_dir_count(handle, &new); 3965 retval = 0; 3966 3967 end_rename: 3968 brelse(old.dir_bh); 3969 brelse(new.dir_bh); 3970 brelse(old.bh); 3971 brelse(new.bh); 3972 if (handle) 3973 ext4_journal_stop(handle); 3974 return retval; 3975 } 3976 3977 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry, 3978 struct inode *new_dir, struct dentry *new_dentry, 3979 unsigned int flags) 3980 { 3981 int err; 3982 3983 if (unlikely(ext4_forced_shutdown(EXT4_SB(old_dir->i_sb)))) 3984 return -EIO; 3985 3986 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT)) 3987 return -EINVAL; 3988 3989 err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry, 3990 flags); 3991 if (err) 3992 return err; 3993 3994 if (flags & RENAME_EXCHANGE) { 3995 return ext4_cross_rename(old_dir, old_dentry, 3996 new_dir, new_dentry); 3997 } 3998 3999 return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags); 4000 } 4001 4002 /* 4003 * directories can handle most operations... 4004 */ 4005 const struct inode_operations ext4_dir_inode_operations = { 4006 .create = ext4_create, 4007 .lookup = ext4_lookup, 4008 .link = ext4_link, 4009 .unlink = ext4_unlink, 4010 .symlink = ext4_symlink, 4011 .mkdir = ext4_mkdir, 4012 .rmdir = ext4_rmdir, 4013 .mknod = ext4_mknod, 4014 .tmpfile = ext4_tmpfile, 4015 .rename = ext4_rename2, 4016 .setattr = ext4_setattr, 4017 .getattr = ext4_getattr, 4018 .listxattr = ext4_listxattr, 4019 .get_acl = ext4_get_acl, 4020 .set_acl = ext4_set_acl, 4021 .fiemap = ext4_fiemap, 4022 }; 4023 4024 const struct inode_operations ext4_special_inode_operations = { 4025 .setattr = ext4_setattr, 4026 .getattr = ext4_getattr, 4027 .listxattr = ext4_listxattr, 4028 .get_acl = ext4_get_acl, 4029 .set_acl = ext4_set_acl, 4030 }; 4031