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 if (ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_EIO)) 113 bh = ERR_PTR(-EIO); 114 else 115 bh = ext4_bread(NULL, inode, block, 0); 116 if (IS_ERR(bh)) { 117 __ext4_warning(inode->i_sb, func, line, 118 "inode #%lu: lblock %lu: comm %s: " 119 "error %ld reading directory block", 120 inode->i_ino, (unsigned long)block, 121 current->comm, PTR_ERR(bh)); 122 123 return bh; 124 } 125 if (!bh && (type == INDEX || type == DIRENT_HTREE)) { 126 ext4_error_inode(inode, func, line, block, 127 "Directory hole found for htree %s block", 128 (type == INDEX) ? "index" : "leaf"); 129 return ERR_PTR(-EFSCORRUPTED); 130 } 131 if (!bh) 132 return NULL; 133 dirent = (struct ext4_dir_entry *) bh->b_data; 134 /* Determine whether or not we have an index block */ 135 if (is_dx(inode)) { 136 if (block == 0) 137 is_dx_block = 1; 138 else if (ext4_rec_len_from_disk(dirent->rec_len, 139 inode->i_sb->s_blocksize) == 140 inode->i_sb->s_blocksize) 141 is_dx_block = 1; 142 } 143 if (!is_dx_block && type == INDEX) { 144 ext4_error_inode(inode, func, line, block, 145 "directory leaf block found instead of index block"); 146 brelse(bh); 147 return ERR_PTR(-EFSCORRUPTED); 148 } 149 if (!ext4_has_metadata_csum(inode->i_sb) || 150 buffer_verified(bh)) 151 return bh; 152 153 /* 154 * An empty leaf block can get mistaken for a index block; for 155 * this reason, we can only check the index checksum when the 156 * caller is sure it should be an index block. 157 */ 158 if (is_dx_block && type == INDEX) { 159 if (ext4_dx_csum_verify(inode, dirent) && 160 !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC)) 161 set_buffer_verified(bh); 162 else { 163 ext4_set_errno(inode->i_sb, EFSBADCRC); 164 ext4_error_inode(inode, func, line, block, 165 "Directory index failed checksum"); 166 brelse(bh); 167 return ERR_PTR(-EFSBADCRC); 168 } 169 } 170 if (!is_dx_block) { 171 if (ext4_dirblock_csum_verify(inode, bh) && 172 !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC)) 173 set_buffer_verified(bh); 174 else { 175 ext4_set_errno(inode->i_sb, EFSBADCRC); 176 ext4_error_inode(inode, func, line, block, 177 "Directory block failed checksum"); 178 brelse(bh); 179 return ERR_PTR(-EFSBADCRC); 180 } 181 } 182 return bh; 183 } 184 185 #ifndef assert 186 #define assert(test) J_ASSERT(test) 187 #endif 188 189 #ifdef DX_DEBUG 190 #define dxtrace(command) command 191 #else 192 #define dxtrace(command) 193 #endif 194 195 struct fake_dirent 196 { 197 __le32 inode; 198 __le16 rec_len; 199 u8 name_len; 200 u8 file_type; 201 }; 202 203 struct dx_countlimit 204 { 205 __le16 limit; 206 __le16 count; 207 }; 208 209 struct dx_entry 210 { 211 __le32 hash; 212 __le32 block; 213 }; 214 215 /* 216 * dx_root_info is laid out so that if it should somehow get overlaid by a 217 * dirent the two low bits of the hash version will be zero. Therefore, the 218 * hash version mod 4 should never be 0. Sincerely, the paranoia department. 219 */ 220 221 struct dx_root 222 { 223 struct fake_dirent dot; 224 char dot_name[4]; 225 struct fake_dirent dotdot; 226 char dotdot_name[4]; 227 struct dx_root_info 228 { 229 __le32 reserved_zero; 230 u8 hash_version; 231 u8 info_length; /* 8 */ 232 u8 indirect_levels; 233 u8 unused_flags; 234 } 235 info; 236 struct dx_entry entries[0]; 237 }; 238 239 struct dx_node 240 { 241 struct fake_dirent fake; 242 struct dx_entry entries[0]; 243 }; 244 245 246 struct dx_frame 247 { 248 struct buffer_head *bh; 249 struct dx_entry *entries; 250 struct dx_entry *at; 251 }; 252 253 struct dx_map_entry 254 { 255 u32 hash; 256 u16 offs; 257 u16 size; 258 }; 259 260 /* 261 * This goes at the end of each htree block. 262 */ 263 struct dx_tail { 264 u32 dt_reserved; 265 __le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */ 266 }; 267 268 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry); 269 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value); 270 static inline unsigned dx_get_hash(struct dx_entry *entry); 271 static void dx_set_hash(struct dx_entry *entry, unsigned value); 272 static unsigned dx_get_count(struct dx_entry *entries); 273 static unsigned dx_get_limit(struct dx_entry *entries); 274 static void dx_set_count(struct dx_entry *entries, unsigned value); 275 static void dx_set_limit(struct dx_entry *entries, unsigned value); 276 static unsigned dx_root_limit(struct inode *dir, unsigned infosize); 277 static unsigned dx_node_limit(struct inode *dir); 278 static struct dx_frame *dx_probe(struct ext4_filename *fname, 279 struct inode *dir, 280 struct dx_hash_info *hinfo, 281 struct dx_frame *frame); 282 static void dx_release(struct dx_frame *frames); 283 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de, 284 unsigned blocksize, struct dx_hash_info *hinfo, 285 struct dx_map_entry map[]); 286 static void dx_sort_map(struct dx_map_entry *map, unsigned count); 287 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to, 288 struct dx_map_entry *offsets, int count, unsigned blocksize); 289 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize); 290 static void dx_insert_block(struct dx_frame *frame, 291 u32 hash, ext4_lblk_t block); 292 static int ext4_htree_next_block(struct inode *dir, __u32 hash, 293 struct dx_frame *frame, 294 struct dx_frame *frames, 295 __u32 *start_hash); 296 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, 297 struct ext4_filename *fname, 298 struct ext4_dir_entry_2 **res_dir); 299 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname, 300 struct inode *dir, struct inode *inode); 301 302 /* checksumming functions */ 303 void ext4_initialize_dirent_tail(struct buffer_head *bh, 304 unsigned int blocksize) 305 { 306 struct ext4_dir_entry_tail *t = EXT4_DIRENT_TAIL(bh->b_data, blocksize); 307 308 memset(t, 0, sizeof(struct ext4_dir_entry_tail)); 309 t->det_rec_len = ext4_rec_len_to_disk( 310 sizeof(struct ext4_dir_entry_tail), blocksize); 311 t->det_reserved_ft = EXT4_FT_DIR_CSUM; 312 } 313 314 /* Walk through a dirent block to find a checksum "dirent" at the tail */ 315 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode, 316 struct buffer_head *bh) 317 { 318 struct ext4_dir_entry_tail *t; 319 320 #ifdef PARANOID 321 struct ext4_dir_entry *d, *top; 322 323 d = (struct ext4_dir_entry *)bh->b_data; 324 top = (struct ext4_dir_entry *)(bh->b_data + 325 (EXT4_BLOCK_SIZE(inode->i_sb) - 326 sizeof(struct ext4_dir_entry_tail))); 327 while (d < top && d->rec_len) 328 d = (struct ext4_dir_entry *)(((void *)d) + 329 le16_to_cpu(d->rec_len)); 330 331 if (d != top) 332 return NULL; 333 334 t = (struct ext4_dir_entry_tail *)d; 335 #else 336 t = EXT4_DIRENT_TAIL(bh->b_data, EXT4_BLOCK_SIZE(inode->i_sb)); 337 #endif 338 339 if (t->det_reserved_zero1 || 340 le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) || 341 t->det_reserved_zero2 || 342 t->det_reserved_ft != EXT4_FT_DIR_CSUM) 343 return NULL; 344 345 return t; 346 } 347 348 static __le32 ext4_dirblock_csum(struct inode *inode, void *dirent, int size) 349 { 350 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 351 struct ext4_inode_info *ei = EXT4_I(inode); 352 __u32 csum; 353 354 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size); 355 return cpu_to_le32(csum); 356 } 357 358 #define warn_no_space_for_csum(inode) \ 359 __warn_no_space_for_csum((inode), __func__, __LINE__) 360 361 static void __warn_no_space_for_csum(struct inode *inode, const char *func, 362 unsigned int line) 363 { 364 __ext4_warning_inode(inode, func, line, 365 "No space for directory leaf checksum. Please run e2fsck -D."); 366 } 367 368 int ext4_dirblock_csum_verify(struct inode *inode, struct buffer_head *bh) 369 { 370 struct ext4_dir_entry_tail *t; 371 372 if (!ext4_has_metadata_csum(inode->i_sb)) 373 return 1; 374 375 t = get_dirent_tail(inode, bh); 376 if (!t) { 377 warn_no_space_for_csum(inode); 378 return 0; 379 } 380 381 if (t->det_checksum != ext4_dirblock_csum(inode, bh->b_data, 382 (char *)t - bh->b_data)) 383 return 0; 384 385 return 1; 386 } 387 388 static void ext4_dirblock_csum_set(struct inode *inode, 389 struct buffer_head *bh) 390 { 391 struct ext4_dir_entry_tail *t; 392 393 if (!ext4_has_metadata_csum(inode->i_sb)) 394 return; 395 396 t = get_dirent_tail(inode, bh); 397 if (!t) { 398 warn_no_space_for_csum(inode); 399 return; 400 } 401 402 t->det_checksum = ext4_dirblock_csum(inode, bh->b_data, 403 (char *)t - bh->b_data); 404 } 405 406 int ext4_handle_dirty_dirblock(handle_t *handle, 407 struct inode *inode, 408 struct buffer_head *bh) 409 { 410 ext4_dirblock_csum_set(inode, bh); 411 return ext4_handle_dirty_metadata(handle, inode, bh); 412 } 413 414 static struct dx_countlimit *get_dx_countlimit(struct inode *inode, 415 struct ext4_dir_entry *dirent, 416 int *offset) 417 { 418 struct ext4_dir_entry *dp; 419 struct dx_root_info *root; 420 int count_offset; 421 422 if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb)) 423 count_offset = 8; 424 else if (le16_to_cpu(dirent->rec_len) == 12) { 425 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12); 426 if (le16_to_cpu(dp->rec_len) != 427 EXT4_BLOCK_SIZE(inode->i_sb) - 12) 428 return NULL; 429 root = (struct dx_root_info *)(((void *)dp + 12)); 430 if (root->reserved_zero || 431 root->info_length != sizeof(struct dx_root_info)) 432 return NULL; 433 count_offset = 32; 434 } else 435 return NULL; 436 437 if (offset) 438 *offset = count_offset; 439 return (struct dx_countlimit *)(((void *)dirent) + count_offset); 440 } 441 442 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent, 443 int count_offset, int count, struct dx_tail *t) 444 { 445 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 446 struct ext4_inode_info *ei = EXT4_I(inode); 447 __u32 csum; 448 int size; 449 __u32 dummy_csum = 0; 450 int offset = offsetof(struct dx_tail, dt_checksum); 451 452 size = count_offset + (count * sizeof(struct dx_entry)); 453 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size); 454 csum = ext4_chksum(sbi, csum, (__u8 *)t, offset); 455 csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum)); 456 457 return cpu_to_le32(csum); 458 } 459 460 static int ext4_dx_csum_verify(struct inode *inode, 461 struct ext4_dir_entry *dirent) 462 { 463 struct dx_countlimit *c; 464 struct dx_tail *t; 465 int count_offset, limit, count; 466 467 if (!ext4_has_metadata_csum(inode->i_sb)) 468 return 1; 469 470 c = get_dx_countlimit(inode, dirent, &count_offset); 471 if (!c) { 472 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D."); 473 return 0; 474 } 475 limit = le16_to_cpu(c->limit); 476 count = le16_to_cpu(c->count); 477 if (count_offset + (limit * sizeof(struct dx_entry)) > 478 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) { 479 warn_no_space_for_csum(inode); 480 return 0; 481 } 482 t = (struct dx_tail *)(((struct dx_entry *)c) + limit); 483 484 if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset, 485 count, t)) 486 return 0; 487 return 1; 488 } 489 490 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent) 491 { 492 struct dx_countlimit *c; 493 struct dx_tail *t; 494 int count_offset, limit, count; 495 496 if (!ext4_has_metadata_csum(inode->i_sb)) 497 return; 498 499 c = get_dx_countlimit(inode, dirent, &count_offset); 500 if (!c) { 501 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D."); 502 return; 503 } 504 limit = le16_to_cpu(c->limit); 505 count = le16_to_cpu(c->count); 506 if (count_offset + (limit * sizeof(struct dx_entry)) > 507 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) { 508 warn_no_space_for_csum(inode); 509 return; 510 } 511 t = (struct dx_tail *)(((struct dx_entry *)c) + limit); 512 513 t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t); 514 } 515 516 static inline int ext4_handle_dirty_dx_node(handle_t *handle, 517 struct inode *inode, 518 struct buffer_head *bh) 519 { 520 ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data); 521 return ext4_handle_dirty_metadata(handle, inode, bh); 522 } 523 524 /* 525 * p is at least 6 bytes before the end of page 526 */ 527 static inline struct ext4_dir_entry_2 * 528 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize) 529 { 530 return (struct ext4_dir_entry_2 *)((char *)p + 531 ext4_rec_len_from_disk(p->rec_len, blocksize)); 532 } 533 534 /* 535 * Future: use high four bits of block for coalesce-on-delete flags 536 * Mask them off for now. 537 */ 538 539 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry) 540 { 541 return le32_to_cpu(entry->block) & 0x0fffffff; 542 } 543 544 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value) 545 { 546 entry->block = cpu_to_le32(value); 547 } 548 549 static inline unsigned dx_get_hash(struct dx_entry *entry) 550 { 551 return le32_to_cpu(entry->hash); 552 } 553 554 static inline void dx_set_hash(struct dx_entry *entry, unsigned value) 555 { 556 entry->hash = cpu_to_le32(value); 557 } 558 559 static inline unsigned dx_get_count(struct dx_entry *entries) 560 { 561 return le16_to_cpu(((struct dx_countlimit *) entries)->count); 562 } 563 564 static inline unsigned dx_get_limit(struct dx_entry *entries) 565 { 566 return le16_to_cpu(((struct dx_countlimit *) entries)->limit); 567 } 568 569 static inline void dx_set_count(struct dx_entry *entries, unsigned value) 570 { 571 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value); 572 } 573 574 static inline void dx_set_limit(struct dx_entry *entries, unsigned value) 575 { 576 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value); 577 } 578 579 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize) 580 { 581 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) - 582 EXT4_DIR_REC_LEN(2) - infosize; 583 584 if (ext4_has_metadata_csum(dir->i_sb)) 585 entry_space -= sizeof(struct dx_tail); 586 return entry_space / sizeof(struct dx_entry); 587 } 588 589 static inline unsigned dx_node_limit(struct inode *dir) 590 { 591 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0); 592 593 if (ext4_has_metadata_csum(dir->i_sb)) 594 entry_space -= sizeof(struct dx_tail); 595 return entry_space / sizeof(struct dx_entry); 596 } 597 598 /* 599 * Debug 600 */ 601 #ifdef DX_DEBUG 602 static void dx_show_index(char * label, struct dx_entry *entries) 603 { 604 int i, n = dx_get_count (entries); 605 printk(KERN_DEBUG "%s index", label); 606 for (i = 0; i < n; i++) { 607 printk(KERN_CONT " %x->%lu", 608 i ? dx_get_hash(entries + i) : 0, 609 (unsigned long)dx_get_block(entries + i)); 610 } 611 printk(KERN_CONT "\n"); 612 } 613 614 struct stats 615 { 616 unsigned names; 617 unsigned space; 618 unsigned bcount; 619 }; 620 621 static struct stats dx_show_leaf(struct inode *dir, 622 struct dx_hash_info *hinfo, 623 struct ext4_dir_entry_2 *de, 624 int size, int show_names) 625 { 626 unsigned names = 0, space = 0; 627 char *base = (char *) de; 628 struct dx_hash_info h = *hinfo; 629 630 printk("names: "); 631 while ((char *) de < base + size) 632 { 633 if (de->inode) 634 { 635 if (show_names) 636 { 637 #ifdef CONFIG_FS_ENCRYPTION 638 int len; 639 char *name; 640 struct fscrypt_str fname_crypto_str = 641 FSTR_INIT(NULL, 0); 642 int res = 0; 643 644 name = de->name; 645 len = de->name_len; 646 if (IS_ENCRYPTED(dir)) 647 res = fscrypt_get_encryption_info(dir); 648 if (res) { 649 printk(KERN_WARNING "Error setting up" 650 " fname crypto: %d\n", res); 651 } 652 if (!fscrypt_has_encryption_key(dir)) { 653 /* Directory is not encrypted */ 654 ext4fs_dirhash(dir, de->name, 655 de->name_len, &h); 656 printk("%*.s:(U)%x.%u ", len, 657 name, h.hash, 658 (unsigned) ((char *) de 659 - base)); 660 } else { 661 struct fscrypt_str de_name = 662 FSTR_INIT(name, len); 663 664 /* Directory is encrypted */ 665 res = fscrypt_fname_alloc_buffer( 666 dir, len, 667 &fname_crypto_str); 668 if (res) 669 printk(KERN_WARNING "Error " 670 "allocating crypto " 671 "buffer--skipping " 672 "crypto\n"); 673 res = fscrypt_fname_disk_to_usr(dir, 674 0, 0, &de_name, 675 &fname_crypto_str); 676 if (res) { 677 printk(KERN_WARNING "Error " 678 "converting filename " 679 "from disk to usr" 680 "\n"); 681 name = "??"; 682 len = 2; 683 } else { 684 name = fname_crypto_str.name; 685 len = fname_crypto_str.len; 686 } 687 ext4fs_dirhash(dir, de->name, 688 de->name_len, &h); 689 printk("%*.s:(E)%x.%u ", len, name, 690 h.hash, (unsigned) ((char *) de 691 - base)); 692 fscrypt_fname_free_buffer( 693 &fname_crypto_str); 694 } 695 #else 696 int len = de->name_len; 697 char *name = de->name; 698 ext4fs_dirhash(dir, de->name, de->name_len, &h); 699 printk("%*.s:%x.%u ", len, name, h.hash, 700 (unsigned) ((char *) de - base)); 701 #endif 702 } 703 space += EXT4_DIR_REC_LEN(de->name_len); 704 names++; 705 } 706 de = ext4_next_entry(de, size); 707 } 708 printk(KERN_CONT "(%i)\n", names); 709 return (struct stats) { names, space, 1 }; 710 } 711 712 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir, 713 struct dx_entry *entries, int levels) 714 { 715 unsigned blocksize = dir->i_sb->s_blocksize; 716 unsigned count = dx_get_count(entries), names = 0, space = 0, i; 717 unsigned bcount = 0; 718 struct buffer_head *bh; 719 printk("%i indexed blocks...\n", count); 720 for (i = 0; i < count; i++, entries++) 721 { 722 ext4_lblk_t block = dx_get_block(entries); 723 ext4_lblk_t hash = i ? dx_get_hash(entries): 0; 724 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash; 725 struct stats stats; 726 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range); 727 bh = ext4_bread(NULL,dir, block, 0); 728 if (!bh || IS_ERR(bh)) 729 continue; 730 stats = levels? 731 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1): 732 dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) 733 bh->b_data, blocksize, 0); 734 names += stats.names; 735 space += stats.space; 736 bcount += stats.bcount; 737 brelse(bh); 738 } 739 if (bcount) 740 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n", 741 levels ? "" : " ", names, space/bcount, 742 (space/bcount)*100/blocksize); 743 return (struct stats) { names, space, bcount}; 744 } 745 #endif /* DX_DEBUG */ 746 747 /* 748 * Probe for a directory leaf block to search. 749 * 750 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format 751 * error in the directory index, and the caller should fall back to 752 * searching the directory normally. The callers of dx_probe **MUST** 753 * check for this error code, and make sure it never gets reflected 754 * back to userspace. 755 */ 756 static struct dx_frame * 757 dx_probe(struct ext4_filename *fname, struct inode *dir, 758 struct dx_hash_info *hinfo, struct dx_frame *frame_in) 759 { 760 unsigned count, indirect; 761 struct dx_entry *at, *entries, *p, *q, *m; 762 struct dx_root *root; 763 struct dx_frame *frame = frame_in; 764 struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR); 765 u32 hash; 766 767 memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0])); 768 frame->bh = ext4_read_dirblock(dir, 0, INDEX); 769 if (IS_ERR(frame->bh)) 770 return (struct dx_frame *) frame->bh; 771 772 root = (struct dx_root *) frame->bh->b_data; 773 if (root->info.hash_version != DX_HASH_TEA && 774 root->info.hash_version != DX_HASH_HALF_MD4 && 775 root->info.hash_version != DX_HASH_LEGACY) { 776 ext4_warning_inode(dir, "Unrecognised inode hash code %u", 777 root->info.hash_version); 778 goto fail; 779 } 780 if (fname) 781 hinfo = &fname->hinfo; 782 hinfo->hash_version = root->info.hash_version; 783 if (hinfo->hash_version <= DX_HASH_TEA) 784 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; 785 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed; 786 if (fname && fname_name(fname)) 787 ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), hinfo); 788 hash = hinfo->hash; 789 790 if (root->info.unused_flags & 1) { 791 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x", 792 root->info.unused_flags); 793 goto fail; 794 } 795 796 indirect = root->info.indirect_levels; 797 if (indirect >= ext4_dir_htree_level(dir->i_sb)) { 798 ext4_warning(dir->i_sb, 799 "Directory (ino: %lu) htree depth %#06x exceed" 800 "supported value", dir->i_ino, 801 ext4_dir_htree_level(dir->i_sb)); 802 if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) { 803 ext4_warning(dir->i_sb, "Enable large directory " 804 "feature to access it"); 805 } 806 goto fail; 807 } 808 809 entries = (struct dx_entry *)(((char *)&root->info) + 810 root->info.info_length); 811 812 if (dx_get_limit(entries) != dx_root_limit(dir, 813 root->info.info_length)) { 814 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u", 815 dx_get_limit(entries), 816 dx_root_limit(dir, root->info.info_length)); 817 goto fail; 818 } 819 820 dxtrace(printk("Look up %x", hash)); 821 while (1) { 822 count = dx_get_count(entries); 823 if (!count || count > dx_get_limit(entries)) { 824 ext4_warning_inode(dir, 825 "dx entry: count %u beyond limit %u", 826 count, dx_get_limit(entries)); 827 goto fail; 828 } 829 830 p = entries + 1; 831 q = entries + count - 1; 832 while (p <= q) { 833 m = p + (q - p) / 2; 834 dxtrace(printk(KERN_CONT ".")); 835 if (dx_get_hash(m) > hash) 836 q = m - 1; 837 else 838 p = m + 1; 839 } 840 841 if (0) { // linear search cross check 842 unsigned n = count - 1; 843 at = entries; 844 while (n--) 845 { 846 dxtrace(printk(KERN_CONT ",")); 847 if (dx_get_hash(++at) > hash) 848 { 849 at--; 850 break; 851 } 852 } 853 assert (at == p - 1); 854 } 855 856 at = p - 1; 857 dxtrace(printk(KERN_CONT " %x->%u\n", 858 at == entries ? 0 : dx_get_hash(at), 859 dx_get_block(at))); 860 frame->entries = entries; 861 frame->at = at; 862 if (!indirect--) 863 return frame; 864 frame++; 865 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX); 866 if (IS_ERR(frame->bh)) { 867 ret_err = (struct dx_frame *) frame->bh; 868 frame->bh = NULL; 869 goto fail; 870 } 871 entries = ((struct dx_node *) frame->bh->b_data)->entries; 872 873 if (dx_get_limit(entries) != dx_node_limit(dir)) { 874 ext4_warning_inode(dir, 875 "dx entry: limit %u != node limit %u", 876 dx_get_limit(entries), dx_node_limit(dir)); 877 goto fail; 878 } 879 } 880 fail: 881 while (frame >= frame_in) { 882 brelse(frame->bh); 883 frame--; 884 } 885 886 if (ret_err == ERR_PTR(ERR_BAD_DX_DIR)) 887 ext4_warning_inode(dir, 888 "Corrupt directory, running e2fsck is recommended"); 889 return ret_err; 890 } 891 892 static void dx_release(struct dx_frame *frames) 893 { 894 struct dx_root_info *info; 895 int i; 896 unsigned int indirect_levels; 897 898 if (frames[0].bh == NULL) 899 return; 900 901 info = &((struct dx_root *)frames[0].bh->b_data)->info; 902 /* save local copy, "info" may be freed after brelse() */ 903 indirect_levels = info->indirect_levels; 904 for (i = 0; i <= indirect_levels; i++) { 905 if (frames[i].bh == NULL) 906 break; 907 brelse(frames[i].bh); 908 frames[i].bh = NULL; 909 } 910 } 911 912 /* 913 * This function increments the frame pointer to search the next leaf 914 * block, and reads in the necessary intervening nodes if the search 915 * should be necessary. Whether or not the search is necessary is 916 * controlled by the hash parameter. If the hash value is even, then 917 * the search is only continued if the next block starts with that 918 * hash value. This is used if we are searching for a specific file. 919 * 920 * If the hash value is HASH_NB_ALWAYS, then always go to the next block. 921 * 922 * This function returns 1 if the caller should continue to search, 923 * or 0 if it should not. If there is an error reading one of the 924 * index blocks, it will a negative error code. 925 * 926 * If start_hash is non-null, it will be filled in with the starting 927 * hash of the next page. 928 */ 929 static int ext4_htree_next_block(struct inode *dir, __u32 hash, 930 struct dx_frame *frame, 931 struct dx_frame *frames, 932 __u32 *start_hash) 933 { 934 struct dx_frame *p; 935 struct buffer_head *bh; 936 int num_frames = 0; 937 __u32 bhash; 938 939 p = frame; 940 /* 941 * Find the next leaf page by incrementing the frame pointer. 942 * If we run out of entries in the interior node, loop around and 943 * increment pointer in the parent node. When we break out of 944 * this loop, num_frames indicates the number of interior 945 * nodes need to be read. 946 */ 947 while (1) { 948 if (++(p->at) < p->entries + dx_get_count(p->entries)) 949 break; 950 if (p == frames) 951 return 0; 952 num_frames++; 953 p--; 954 } 955 956 /* 957 * If the hash is 1, then continue only if the next page has a 958 * continuation hash of any value. This is used for readdir 959 * handling. Otherwise, check to see if the hash matches the 960 * desired contiuation hash. If it doesn't, return since 961 * there's no point to read in the successive index pages. 962 */ 963 bhash = dx_get_hash(p->at); 964 if (start_hash) 965 *start_hash = bhash; 966 if ((hash & 1) == 0) { 967 if ((bhash & ~1) != hash) 968 return 0; 969 } 970 /* 971 * If the hash is HASH_NB_ALWAYS, we always go to the next 972 * block so no check is necessary 973 */ 974 while (num_frames--) { 975 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX); 976 if (IS_ERR(bh)) 977 return PTR_ERR(bh); 978 p++; 979 brelse(p->bh); 980 p->bh = bh; 981 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries; 982 } 983 return 1; 984 } 985 986 987 /* 988 * This function fills a red-black tree with information from a 989 * directory block. It returns the number directory entries loaded 990 * into the tree. If there is an error it is returned in err. 991 */ 992 static int htree_dirblock_to_tree(struct file *dir_file, 993 struct inode *dir, ext4_lblk_t block, 994 struct dx_hash_info *hinfo, 995 __u32 start_hash, __u32 start_minor_hash) 996 { 997 struct buffer_head *bh; 998 struct ext4_dir_entry_2 *de, *top; 999 int err = 0, count = 0; 1000 struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str; 1001 1002 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n", 1003 (unsigned long)block)); 1004 bh = ext4_read_dirblock(dir, block, DIRENT_HTREE); 1005 if (IS_ERR(bh)) 1006 return PTR_ERR(bh); 1007 1008 de = (struct ext4_dir_entry_2 *) bh->b_data; 1009 top = (struct ext4_dir_entry_2 *) ((char *) de + 1010 dir->i_sb->s_blocksize - 1011 EXT4_DIR_REC_LEN(0)); 1012 /* Check if the directory is encrypted */ 1013 if (IS_ENCRYPTED(dir)) { 1014 err = fscrypt_get_encryption_info(dir); 1015 if (err < 0) { 1016 brelse(bh); 1017 return err; 1018 } 1019 err = fscrypt_fname_alloc_buffer(dir, EXT4_NAME_LEN, 1020 &fname_crypto_str); 1021 if (err < 0) { 1022 brelse(bh); 1023 return err; 1024 } 1025 } 1026 1027 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) { 1028 if (ext4_check_dir_entry(dir, NULL, de, bh, 1029 bh->b_data, bh->b_size, 1030 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb)) 1031 + ((char *)de - bh->b_data))) { 1032 /* silently ignore the rest of the block */ 1033 break; 1034 } 1035 ext4fs_dirhash(dir, de->name, de->name_len, hinfo); 1036 if ((hinfo->hash < start_hash) || 1037 ((hinfo->hash == start_hash) && 1038 (hinfo->minor_hash < start_minor_hash))) 1039 continue; 1040 if (de->inode == 0) 1041 continue; 1042 if (!IS_ENCRYPTED(dir)) { 1043 tmp_str.name = de->name; 1044 tmp_str.len = de->name_len; 1045 err = ext4_htree_store_dirent(dir_file, 1046 hinfo->hash, hinfo->minor_hash, de, 1047 &tmp_str); 1048 } else { 1049 int save_len = fname_crypto_str.len; 1050 struct fscrypt_str de_name = FSTR_INIT(de->name, 1051 de->name_len); 1052 1053 /* Directory is encrypted */ 1054 err = fscrypt_fname_disk_to_usr(dir, hinfo->hash, 1055 hinfo->minor_hash, &de_name, 1056 &fname_crypto_str); 1057 if (err) { 1058 count = err; 1059 goto errout; 1060 } 1061 err = ext4_htree_store_dirent(dir_file, 1062 hinfo->hash, hinfo->minor_hash, de, 1063 &fname_crypto_str); 1064 fname_crypto_str.len = save_len; 1065 } 1066 if (err != 0) { 1067 count = err; 1068 goto errout; 1069 } 1070 count++; 1071 } 1072 errout: 1073 brelse(bh); 1074 fscrypt_fname_free_buffer(&fname_crypto_str); 1075 return count; 1076 } 1077 1078 1079 /* 1080 * This function fills a red-black tree with information from a 1081 * directory. We start scanning the directory in hash order, starting 1082 * at start_hash and start_minor_hash. 1083 * 1084 * This function returns the number of entries inserted into the tree, 1085 * or a negative error code. 1086 */ 1087 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash, 1088 __u32 start_minor_hash, __u32 *next_hash) 1089 { 1090 struct dx_hash_info hinfo; 1091 struct ext4_dir_entry_2 *de; 1092 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 1093 struct inode *dir; 1094 ext4_lblk_t block; 1095 int count = 0; 1096 int ret, err; 1097 __u32 hashval; 1098 struct fscrypt_str tmp_str; 1099 1100 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n", 1101 start_hash, start_minor_hash)); 1102 dir = file_inode(dir_file); 1103 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) { 1104 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version; 1105 if (hinfo.hash_version <= DX_HASH_TEA) 1106 hinfo.hash_version += 1107 EXT4_SB(dir->i_sb)->s_hash_unsigned; 1108 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; 1109 if (ext4_has_inline_data(dir)) { 1110 int has_inline_data = 1; 1111 count = ext4_inlinedir_to_tree(dir_file, dir, 0, 1112 &hinfo, start_hash, 1113 start_minor_hash, 1114 &has_inline_data); 1115 if (has_inline_data) { 1116 *next_hash = ~0; 1117 return count; 1118 } 1119 } 1120 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo, 1121 start_hash, start_minor_hash); 1122 *next_hash = ~0; 1123 return count; 1124 } 1125 hinfo.hash = start_hash; 1126 hinfo.minor_hash = 0; 1127 frame = dx_probe(NULL, dir, &hinfo, frames); 1128 if (IS_ERR(frame)) 1129 return PTR_ERR(frame); 1130 1131 /* Add '.' and '..' from the htree header */ 1132 if (!start_hash && !start_minor_hash) { 1133 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; 1134 tmp_str.name = de->name; 1135 tmp_str.len = de->name_len; 1136 err = ext4_htree_store_dirent(dir_file, 0, 0, 1137 de, &tmp_str); 1138 if (err != 0) 1139 goto errout; 1140 count++; 1141 } 1142 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) { 1143 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; 1144 de = ext4_next_entry(de, dir->i_sb->s_blocksize); 1145 tmp_str.name = de->name; 1146 tmp_str.len = de->name_len; 1147 err = ext4_htree_store_dirent(dir_file, 2, 0, 1148 de, &tmp_str); 1149 if (err != 0) 1150 goto errout; 1151 count++; 1152 } 1153 1154 while (1) { 1155 if (fatal_signal_pending(current)) { 1156 err = -ERESTARTSYS; 1157 goto errout; 1158 } 1159 cond_resched(); 1160 block = dx_get_block(frame->at); 1161 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo, 1162 start_hash, start_minor_hash); 1163 if (ret < 0) { 1164 err = ret; 1165 goto errout; 1166 } 1167 count += ret; 1168 hashval = ~0; 1169 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS, 1170 frame, frames, &hashval); 1171 *next_hash = hashval; 1172 if (ret < 0) { 1173 err = ret; 1174 goto errout; 1175 } 1176 /* 1177 * Stop if: (a) there are no more entries, or 1178 * (b) we have inserted at least one entry and the 1179 * next hash value is not a continuation 1180 */ 1181 if ((ret == 0) || 1182 (count && ((hashval & 1) == 0))) 1183 break; 1184 } 1185 dx_release(frames); 1186 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, " 1187 "next hash: %x\n", count, *next_hash)); 1188 return count; 1189 errout: 1190 dx_release(frames); 1191 return (err); 1192 } 1193 1194 static inline int search_dirblock(struct buffer_head *bh, 1195 struct inode *dir, 1196 struct ext4_filename *fname, 1197 unsigned int offset, 1198 struct ext4_dir_entry_2 **res_dir) 1199 { 1200 return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir, 1201 fname, offset, res_dir); 1202 } 1203 1204 /* 1205 * Directory block splitting, compacting 1206 */ 1207 1208 /* 1209 * Create map of hash values, offsets, and sizes, stored at end of block. 1210 * Returns number of entries mapped. 1211 */ 1212 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de, 1213 unsigned blocksize, struct dx_hash_info *hinfo, 1214 struct dx_map_entry *map_tail) 1215 { 1216 int count = 0; 1217 char *base = (char *) de; 1218 struct dx_hash_info h = *hinfo; 1219 1220 while ((char *) de < base + blocksize) { 1221 if (de->name_len && de->inode) { 1222 ext4fs_dirhash(dir, de->name, de->name_len, &h); 1223 map_tail--; 1224 map_tail->hash = h.hash; 1225 map_tail->offs = ((char *) de - base)>>2; 1226 map_tail->size = le16_to_cpu(de->rec_len); 1227 count++; 1228 cond_resched(); 1229 } 1230 /* XXX: do we need to check rec_len == 0 case? -Chris */ 1231 de = ext4_next_entry(de, blocksize); 1232 } 1233 return count; 1234 } 1235 1236 /* Sort map by hash value */ 1237 static void dx_sort_map (struct dx_map_entry *map, unsigned count) 1238 { 1239 struct dx_map_entry *p, *q, *top = map + count - 1; 1240 int more; 1241 /* Combsort until bubble sort doesn't suck */ 1242 while (count > 2) { 1243 count = count*10/13; 1244 if (count - 9 < 2) /* 9, 10 -> 11 */ 1245 count = 11; 1246 for (p = top, q = p - count; q >= map; p--, q--) 1247 if (p->hash < q->hash) 1248 swap(*p, *q); 1249 } 1250 /* Garden variety bubble sort */ 1251 do { 1252 more = 0; 1253 q = top; 1254 while (q-- > map) { 1255 if (q[1].hash >= q[0].hash) 1256 continue; 1257 swap(*(q+1), *q); 1258 more = 1; 1259 } 1260 } while(more); 1261 } 1262 1263 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block) 1264 { 1265 struct dx_entry *entries = frame->entries; 1266 struct dx_entry *old = frame->at, *new = old + 1; 1267 int count = dx_get_count(entries); 1268 1269 assert(count < dx_get_limit(entries)); 1270 assert(old < entries + count); 1271 memmove(new + 1, new, (char *)(entries + count) - (char *)(new)); 1272 dx_set_hash(new, hash); 1273 dx_set_block(new, block); 1274 dx_set_count(entries, count + 1); 1275 } 1276 1277 #ifdef CONFIG_UNICODE 1278 /* 1279 * Test whether a case-insensitive directory entry matches the filename 1280 * being searched for. If quick is set, assume the name being looked up 1281 * is already in the casefolded form. 1282 * 1283 * Returns: 0 if the directory entry matches, more than 0 if it 1284 * doesn't match or less than zero on error. 1285 */ 1286 int ext4_ci_compare(const struct inode *parent, const struct qstr *name, 1287 const struct qstr *entry, bool quick) 1288 { 1289 const struct ext4_sb_info *sbi = EXT4_SB(parent->i_sb); 1290 const struct unicode_map *um = sbi->s_encoding; 1291 int ret; 1292 1293 if (quick) 1294 ret = utf8_strncasecmp_folded(um, name, entry); 1295 else 1296 ret = utf8_strncasecmp(um, name, entry); 1297 1298 if (ret < 0) { 1299 /* Handle invalid character sequence as either an error 1300 * or as an opaque byte sequence. 1301 */ 1302 if (ext4_has_strict_mode(sbi)) 1303 return -EINVAL; 1304 1305 if (name->len != entry->len) 1306 return 1; 1307 1308 return !!memcmp(name->name, entry->name, name->len); 1309 } 1310 1311 return ret; 1312 } 1313 1314 void ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname, 1315 struct fscrypt_str *cf_name) 1316 { 1317 int len; 1318 1319 if (!IS_CASEFOLDED(dir) || !EXT4_SB(dir->i_sb)->s_encoding) { 1320 cf_name->name = NULL; 1321 return; 1322 } 1323 1324 cf_name->name = kmalloc(EXT4_NAME_LEN, GFP_NOFS); 1325 if (!cf_name->name) 1326 return; 1327 1328 len = utf8_casefold(EXT4_SB(dir->i_sb)->s_encoding, 1329 iname, cf_name->name, 1330 EXT4_NAME_LEN); 1331 if (len <= 0) { 1332 kfree(cf_name->name); 1333 cf_name->name = NULL; 1334 return; 1335 } 1336 cf_name->len = (unsigned) len; 1337 1338 } 1339 #endif 1340 1341 /* 1342 * Test whether a directory entry matches the filename being searched for. 1343 * 1344 * Return: %true if the directory entry matches, otherwise %false. 1345 */ 1346 static inline bool ext4_match(const struct inode *parent, 1347 const struct ext4_filename *fname, 1348 const struct ext4_dir_entry_2 *de) 1349 { 1350 struct fscrypt_name f; 1351 #ifdef CONFIG_UNICODE 1352 const struct qstr entry = {.name = de->name, .len = de->name_len}; 1353 #endif 1354 1355 if (!de->inode) 1356 return false; 1357 1358 f.usr_fname = fname->usr_fname; 1359 f.disk_name = fname->disk_name; 1360 #ifdef CONFIG_FS_ENCRYPTION 1361 f.crypto_buf = fname->crypto_buf; 1362 #endif 1363 1364 #ifdef CONFIG_UNICODE 1365 if (EXT4_SB(parent->i_sb)->s_encoding && IS_CASEFOLDED(parent)) { 1366 if (fname->cf_name.name) { 1367 struct qstr cf = {.name = fname->cf_name.name, 1368 .len = fname->cf_name.len}; 1369 return !ext4_ci_compare(parent, &cf, &entry, true); 1370 } 1371 return !ext4_ci_compare(parent, fname->usr_fname, &entry, 1372 false); 1373 } 1374 #endif 1375 1376 return fscrypt_match_name(&f, de->name, de->name_len); 1377 } 1378 1379 /* 1380 * Returns 0 if not found, -1 on failure, and 1 on success 1381 */ 1382 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size, 1383 struct inode *dir, struct ext4_filename *fname, 1384 unsigned int offset, struct ext4_dir_entry_2 **res_dir) 1385 { 1386 struct ext4_dir_entry_2 * de; 1387 char * dlimit; 1388 int de_len; 1389 1390 de = (struct ext4_dir_entry_2 *)search_buf; 1391 dlimit = search_buf + buf_size; 1392 while ((char *) de < dlimit) { 1393 /* this code is executed quadratically often */ 1394 /* do minimal checking `by hand' */ 1395 if ((char *) de + de->name_len <= dlimit && 1396 ext4_match(dir, fname, de)) { 1397 /* found a match - just to be sure, do 1398 * a full check */ 1399 if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data, 1400 bh->b_size, offset)) 1401 return -1; 1402 *res_dir = de; 1403 return 1; 1404 } 1405 /* prevent looping on a bad block */ 1406 de_len = ext4_rec_len_from_disk(de->rec_len, 1407 dir->i_sb->s_blocksize); 1408 if (de_len <= 0) 1409 return -1; 1410 offset += de_len; 1411 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len); 1412 } 1413 return 0; 1414 } 1415 1416 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block, 1417 struct ext4_dir_entry *de) 1418 { 1419 struct super_block *sb = dir->i_sb; 1420 1421 if (!is_dx(dir)) 1422 return 0; 1423 if (block == 0) 1424 return 1; 1425 if (de->inode == 0 && 1426 ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) == 1427 sb->s_blocksize) 1428 return 1; 1429 return 0; 1430 } 1431 1432 /* 1433 * __ext4_find_entry() 1434 * 1435 * finds an entry in the specified directory with the wanted name. It 1436 * returns the cache buffer in which the entry was found, and the entry 1437 * itself (as a parameter - res_dir). It does NOT read the inode of the 1438 * entry - you'll have to do that yourself if you want to. 1439 * 1440 * The returned buffer_head has ->b_count elevated. The caller is expected 1441 * to brelse() it when appropriate. 1442 */ 1443 static struct buffer_head *__ext4_find_entry(struct inode *dir, 1444 struct ext4_filename *fname, 1445 struct ext4_dir_entry_2 **res_dir, 1446 int *inlined) 1447 { 1448 struct super_block *sb; 1449 struct buffer_head *bh_use[NAMEI_RA_SIZE]; 1450 struct buffer_head *bh, *ret = NULL; 1451 ext4_lblk_t start, block; 1452 const u8 *name = fname->usr_fname->name; 1453 size_t ra_max = 0; /* Number of bh's in the readahead 1454 buffer, bh_use[] */ 1455 size_t ra_ptr = 0; /* Current index into readahead 1456 buffer */ 1457 ext4_lblk_t nblocks; 1458 int i, namelen, retval; 1459 1460 *res_dir = NULL; 1461 sb = dir->i_sb; 1462 namelen = fname->usr_fname->len; 1463 if (namelen > EXT4_NAME_LEN) 1464 return NULL; 1465 1466 if (ext4_has_inline_data(dir)) { 1467 int has_inline_data = 1; 1468 ret = ext4_find_inline_entry(dir, fname, res_dir, 1469 &has_inline_data); 1470 if (has_inline_data) { 1471 if (inlined) 1472 *inlined = 1; 1473 goto cleanup_and_exit; 1474 } 1475 } 1476 1477 if ((namelen <= 2) && (name[0] == '.') && 1478 (name[1] == '.' || name[1] == '\0')) { 1479 /* 1480 * "." or ".." will only be in the first block 1481 * NFS may look up ".."; "." should be handled by the VFS 1482 */ 1483 block = start = 0; 1484 nblocks = 1; 1485 goto restart; 1486 } 1487 if (is_dx(dir)) { 1488 ret = ext4_dx_find_entry(dir, fname, res_dir); 1489 /* 1490 * On success, or if the error was file not found, 1491 * return. Otherwise, fall back to doing a search the 1492 * old fashioned way. 1493 */ 1494 if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR) 1495 goto cleanup_and_exit; 1496 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, " 1497 "falling back\n")); 1498 ret = NULL; 1499 } 1500 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); 1501 if (!nblocks) { 1502 ret = NULL; 1503 goto cleanup_and_exit; 1504 } 1505 start = EXT4_I(dir)->i_dir_start_lookup; 1506 if (start >= nblocks) 1507 start = 0; 1508 block = start; 1509 restart: 1510 do { 1511 /* 1512 * We deal with the read-ahead logic here. 1513 */ 1514 if (ra_ptr >= ra_max) { 1515 /* Refill the readahead buffer */ 1516 ra_ptr = 0; 1517 if (block < start) 1518 ra_max = start - block; 1519 else 1520 ra_max = nblocks - block; 1521 ra_max = min(ra_max, ARRAY_SIZE(bh_use)); 1522 retval = ext4_bread_batch(dir, block, ra_max, 1523 false /* wait */, bh_use); 1524 if (retval) { 1525 ret = ERR_PTR(retval); 1526 ra_max = 0; 1527 goto cleanup_and_exit; 1528 } 1529 } 1530 if ((bh = bh_use[ra_ptr++]) == NULL) 1531 goto next; 1532 wait_on_buffer(bh); 1533 if (!buffer_uptodate(bh)) { 1534 ext4_set_errno(sb, EIO); 1535 EXT4_ERROR_INODE(dir, "reading directory lblock %lu", 1536 (unsigned long) block); 1537 brelse(bh); 1538 ret = ERR_PTR(-EIO); 1539 goto cleanup_and_exit; 1540 } 1541 if (!buffer_verified(bh) && 1542 !is_dx_internal_node(dir, block, 1543 (struct ext4_dir_entry *)bh->b_data) && 1544 !ext4_dirblock_csum_verify(dir, bh)) { 1545 ext4_set_errno(sb, EFSBADCRC); 1546 EXT4_ERROR_INODE(dir, "checksumming directory " 1547 "block %lu", (unsigned long)block); 1548 brelse(bh); 1549 ret = ERR_PTR(-EFSBADCRC); 1550 goto cleanup_and_exit; 1551 } 1552 set_buffer_verified(bh); 1553 i = search_dirblock(bh, dir, fname, 1554 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir); 1555 if (i == 1) { 1556 EXT4_I(dir)->i_dir_start_lookup = block; 1557 ret = bh; 1558 goto cleanup_and_exit; 1559 } else { 1560 brelse(bh); 1561 if (i < 0) 1562 goto cleanup_and_exit; 1563 } 1564 next: 1565 if (++block >= nblocks) 1566 block = 0; 1567 } while (block != start); 1568 1569 /* 1570 * If the directory has grown while we were searching, then 1571 * search the last part of the directory before giving up. 1572 */ 1573 block = nblocks; 1574 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); 1575 if (block < nblocks) { 1576 start = 0; 1577 goto restart; 1578 } 1579 1580 cleanup_and_exit: 1581 /* Clean up the read-ahead blocks */ 1582 for (; ra_ptr < ra_max; ra_ptr++) 1583 brelse(bh_use[ra_ptr]); 1584 return ret; 1585 } 1586 1587 static struct buffer_head *ext4_find_entry(struct inode *dir, 1588 const struct qstr *d_name, 1589 struct ext4_dir_entry_2 **res_dir, 1590 int *inlined) 1591 { 1592 int err; 1593 struct ext4_filename fname; 1594 struct buffer_head *bh; 1595 1596 err = ext4_fname_setup_filename(dir, d_name, 1, &fname); 1597 if (err == -ENOENT) 1598 return NULL; 1599 if (err) 1600 return ERR_PTR(err); 1601 1602 bh = __ext4_find_entry(dir, &fname, res_dir, inlined); 1603 1604 ext4_fname_free_filename(&fname); 1605 return bh; 1606 } 1607 1608 static struct buffer_head *ext4_lookup_entry(struct inode *dir, 1609 struct dentry *dentry, 1610 struct ext4_dir_entry_2 **res_dir) 1611 { 1612 int err; 1613 struct ext4_filename fname; 1614 struct buffer_head *bh; 1615 1616 err = ext4_fname_prepare_lookup(dir, dentry, &fname); 1617 if (err == -ENOENT) 1618 return NULL; 1619 if (err) 1620 return ERR_PTR(err); 1621 1622 bh = __ext4_find_entry(dir, &fname, res_dir, NULL); 1623 1624 ext4_fname_free_filename(&fname); 1625 return bh; 1626 } 1627 1628 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, 1629 struct ext4_filename *fname, 1630 struct ext4_dir_entry_2 **res_dir) 1631 { 1632 struct super_block * sb = dir->i_sb; 1633 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 1634 struct buffer_head *bh; 1635 ext4_lblk_t block; 1636 int retval; 1637 1638 #ifdef CONFIG_FS_ENCRYPTION 1639 *res_dir = NULL; 1640 #endif 1641 frame = dx_probe(fname, dir, NULL, frames); 1642 if (IS_ERR(frame)) 1643 return (struct buffer_head *) frame; 1644 do { 1645 block = dx_get_block(frame->at); 1646 bh = ext4_read_dirblock(dir, block, DIRENT_HTREE); 1647 if (IS_ERR(bh)) 1648 goto errout; 1649 1650 retval = search_dirblock(bh, dir, fname, 1651 block << EXT4_BLOCK_SIZE_BITS(sb), 1652 res_dir); 1653 if (retval == 1) 1654 goto success; 1655 brelse(bh); 1656 if (retval == -1) { 1657 bh = ERR_PTR(ERR_BAD_DX_DIR); 1658 goto errout; 1659 } 1660 1661 /* Check to see if we should continue to search */ 1662 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame, 1663 frames, NULL); 1664 if (retval < 0) { 1665 ext4_warning_inode(dir, 1666 "error %d reading directory index block", 1667 retval); 1668 bh = ERR_PTR(retval); 1669 goto errout; 1670 } 1671 } while (retval == 1); 1672 1673 bh = NULL; 1674 errout: 1675 dxtrace(printk(KERN_DEBUG "%s not found\n", fname->usr_fname->name)); 1676 success: 1677 dx_release(frames); 1678 return bh; 1679 } 1680 1681 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 1682 { 1683 struct inode *inode; 1684 struct ext4_dir_entry_2 *de; 1685 struct buffer_head *bh; 1686 1687 if (dentry->d_name.len > EXT4_NAME_LEN) 1688 return ERR_PTR(-ENAMETOOLONG); 1689 1690 bh = ext4_lookup_entry(dir, dentry, &de); 1691 if (IS_ERR(bh)) 1692 return ERR_CAST(bh); 1693 inode = NULL; 1694 if (bh) { 1695 __u32 ino = le32_to_cpu(de->inode); 1696 brelse(bh); 1697 if (!ext4_valid_inum(dir->i_sb, ino)) { 1698 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino); 1699 return ERR_PTR(-EFSCORRUPTED); 1700 } 1701 if (unlikely(ino == dir->i_ino)) { 1702 EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir", 1703 dentry); 1704 return ERR_PTR(-EFSCORRUPTED); 1705 } 1706 inode = ext4_iget(dir->i_sb, ino, EXT4_IGET_NORMAL); 1707 if (inode == ERR_PTR(-ESTALE)) { 1708 EXT4_ERROR_INODE(dir, 1709 "deleted inode referenced: %u", 1710 ino); 1711 return ERR_PTR(-EFSCORRUPTED); 1712 } 1713 if (!IS_ERR(inode) && IS_ENCRYPTED(dir) && 1714 (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) && 1715 !fscrypt_has_permitted_context(dir, inode)) { 1716 ext4_warning(inode->i_sb, 1717 "Inconsistent encryption contexts: %lu/%lu", 1718 dir->i_ino, inode->i_ino); 1719 iput(inode); 1720 return ERR_PTR(-EPERM); 1721 } 1722 } 1723 1724 #ifdef CONFIG_UNICODE 1725 if (!inode && IS_CASEFOLDED(dir)) { 1726 /* Eventually we want to call d_add_ci(dentry, NULL) 1727 * for negative dentries in the encoding case as 1728 * well. For now, prevent the negative dentry 1729 * from being cached. 1730 */ 1731 return NULL; 1732 } 1733 #endif 1734 return d_splice_alias(inode, dentry); 1735 } 1736 1737 1738 struct dentry *ext4_get_parent(struct dentry *child) 1739 { 1740 __u32 ino; 1741 static const struct qstr dotdot = QSTR_INIT("..", 2); 1742 struct ext4_dir_entry_2 * de; 1743 struct buffer_head *bh; 1744 1745 bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL); 1746 if (IS_ERR(bh)) 1747 return ERR_CAST(bh); 1748 if (!bh) 1749 return ERR_PTR(-ENOENT); 1750 ino = le32_to_cpu(de->inode); 1751 brelse(bh); 1752 1753 if (!ext4_valid_inum(child->d_sb, ino)) { 1754 EXT4_ERROR_INODE(d_inode(child), 1755 "bad parent inode number: %u", ino); 1756 return ERR_PTR(-EFSCORRUPTED); 1757 } 1758 1759 return d_obtain_alias(ext4_iget(child->d_sb, ino, EXT4_IGET_NORMAL)); 1760 } 1761 1762 /* 1763 * Move count entries from end of map between two memory locations. 1764 * Returns pointer to last entry moved. 1765 */ 1766 static struct ext4_dir_entry_2 * 1767 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count, 1768 unsigned blocksize) 1769 { 1770 unsigned rec_len = 0; 1771 1772 while (count--) { 1773 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) 1774 (from + (map->offs<<2)); 1775 rec_len = EXT4_DIR_REC_LEN(de->name_len); 1776 memcpy (to, de, rec_len); 1777 ((struct ext4_dir_entry_2 *) to)->rec_len = 1778 ext4_rec_len_to_disk(rec_len, blocksize); 1779 de->inode = 0; 1780 map++; 1781 to += rec_len; 1782 } 1783 return (struct ext4_dir_entry_2 *) (to - rec_len); 1784 } 1785 1786 /* 1787 * Compact each dir entry in the range to the minimal rec_len. 1788 * Returns pointer to last entry in range. 1789 */ 1790 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize) 1791 { 1792 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base; 1793 unsigned rec_len = 0; 1794 1795 prev = to = de; 1796 while ((char*)de < base + blocksize) { 1797 next = ext4_next_entry(de, blocksize); 1798 if (de->inode && de->name_len) { 1799 rec_len = EXT4_DIR_REC_LEN(de->name_len); 1800 if (de > to) 1801 memmove(to, de, rec_len); 1802 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize); 1803 prev = to; 1804 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len); 1805 } 1806 de = next; 1807 } 1808 return prev; 1809 } 1810 1811 /* 1812 * Split a full leaf block to make room for a new dir entry. 1813 * Allocate a new block, and move entries so that they are approx. equally full. 1814 * Returns pointer to de in block into which the new entry will be inserted. 1815 */ 1816 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir, 1817 struct buffer_head **bh,struct dx_frame *frame, 1818 struct dx_hash_info *hinfo) 1819 { 1820 unsigned blocksize = dir->i_sb->s_blocksize; 1821 unsigned count, continued; 1822 struct buffer_head *bh2; 1823 ext4_lblk_t newblock; 1824 u32 hash2; 1825 struct dx_map_entry *map; 1826 char *data1 = (*bh)->b_data, *data2; 1827 unsigned split, move, size; 1828 struct ext4_dir_entry_2 *de = NULL, *de2; 1829 int csum_size = 0; 1830 int err = 0, i; 1831 1832 if (ext4_has_metadata_csum(dir->i_sb)) 1833 csum_size = sizeof(struct ext4_dir_entry_tail); 1834 1835 bh2 = ext4_append(handle, dir, &newblock); 1836 if (IS_ERR(bh2)) { 1837 brelse(*bh); 1838 *bh = NULL; 1839 return (struct ext4_dir_entry_2 *) bh2; 1840 } 1841 1842 BUFFER_TRACE(*bh, "get_write_access"); 1843 err = ext4_journal_get_write_access(handle, *bh); 1844 if (err) 1845 goto journal_error; 1846 1847 BUFFER_TRACE(frame->bh, "get_write_access"); 1848 err = ext4_journal_get_write_access(handle, frame->bh); 1849 if (err) 1850 goto journal_error; 1851 1852 data2 = bh2->b_data; 1853 1854 /* create map in the end of data2 block */ 1855 map = (struct dx_map_entry *) (data2 + blocksize); 1856 count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1, 1857 blocksize, hinfo, map); 1858 map -= count; 1859 dx_sort_map(map, count); 1860 /* Split the existing block in the middle, size-wise */ 1861 size = 0; 1862 move = 0; 1863 for (i = count-1; i >= 0; i--) { 1864 /* is more than half of this entry in 2nd half of the block? */ 1865 if (size + map[i].size/2 > blocksize/2) 1866 break; 1867 size += map[i].size; 1868 move++; 1869 } 1870 /* map index at which we will split */ 1871 split = count - move; 1872 hash2 = map[split].hash; 1873 continued = hash2 == map[split - 1].hash; 1874 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n", 1875 (unsigned long)dx_get_block(frame->at), 1876 hash2, split, count-split)); 1877 1878 /* Fancy dance to stay within two buffers */ 1879 de2 = dx_move_dirents(data1, data2, map + split, count - split, 1880 blocksize); 1881 de = dx_pack_dirents(data1, blocksize); 1882 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) - 1883 (char *) de, 1884 blocksize); 1885 de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) - 1886 (char *) de2, 1887 blocksize); 1888 if (csum_size) { 1889 ext4_initialize_dirent_tail(*bh, blocksize); 1890 ext4_initialize_dirent_tail(bh2, blocksize); 1891 } 1892 1893 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1, 1894 blocksize, 1)); 1895 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2, 1896 blocksize, 1)); 1897 1898 /* Which block gets the new entry? */ 1899 if (hinfo->hash >= hash2) { 1900 swap(*bh, bh2); 1901 de = de2; 1902 } 1903 dx_insert_block(frame, hash2 + continued, newblock); 1904 err = ext4_handle_dirty_dirblock(handle, dir, bh2); 1905 if (err) 1906 goto journal_error; 1907 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 1908 if (err) 1909 goto journal_error; 1910 brelse(bh2); 1911 dxtrace(dx_show_index("frame", frame->entries)); 1912 return de; 1913 1914 journal_error: 1915 brelse(*bh); 1916 brelse(bh2); 1917 *bh = NULL; 1918 ext4_std_error(dir->i_sb, err); 1919 return ERR_PTR(err); 1920 } 1921 1922 int ext4_find_dest_de(struct inode *dir, struct inode *inode, 1923 struct buffer_head *bh, 1924 void *buf, int buf_size, 1925 struct ext4_filename *fname, 1926 struct ext4_dir_entry_2 **dest_de) 1927 { 1928 struct ext4_dir_entry_2 *de; 1929 unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname)); 1930 int nlen, rlen; 1931 unsigned int offset = 0; 1932 char *top; 1933 1934 de = (struct ext4_dir_entry_2 *)buf; 1935 top = buf + buf_size - reclen; 1936 while ((char *) de <= top) { 1937 if (ext4_check_dir_entry(dir, NULL, de, bh, 1938 buf, buf_size, offset)) 1939 return -EFSCORRUPTED; 1940 if (ext4_match(dir, fname, de)) 1941 return -EEXIST; 1942 nlen = EXT4_DIR_REC_LEN(de->name_len); 1943 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 1944 if ((de->inode ? rlen - nlen : rlen) >= reclen) 1945 break; 1946 de = (struct ext4_dir_entry_2 *)((char *)de + rlen); 1947 offset += rlen; 1948 } 1949 if ((char *) de > top) 1950 return -ENOSPC; 1951 1952 *dest_de = de; 1953 return 0; 1954 } 1955 1956 void ext4_insert_dentry(struct inode *inode, 1957 struct ext4_dir_entry_2 *de, 1958 int buf_size, 1959 struct ext4_filename *fname) 1960 { 1961 1962 int nlen, rlen; 1963 1964 nlen = EXT4_DIR_REC_LEN(de->name_len); 1965 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 1966 if (de->inode) { 1967 struct ext4_dir_entry_2 *de1 = 1968 (struct ext4_dir_entry_2 *)((char *)de + nlen); 1969 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size); 1970 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size); 1971 de = de1; 1972 } 1973 de->file_type = EXT4_FT_UNKNOWN; 1974 de->inode = cpu_to_le32(inode->i_ino); 1975 ext4_set_de_type(inode->i_sb, de, inode->i_mode); 1976 de->name_len = fname_len(fname); 1977 memcpy(de->name, fname_name(fname), fname_len(fname)); 1978 } 1979 1980 /* 1981 * Add a new entry into a directory (leaf) block. If de is non-NULL, 1982 * it points to a directory entry which is guaranteed to be large 1983 * enough for new directory entry. If de is NULL, then 1984 * add_dirent_to_buf will attempt search the directory block for 1985 * space. It will return -ENOSPC if no space is available, and -EIO 1986 * and -EEXIST if directory entry already exists. 1987 */ 1988 static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname, 1989 struct inode *dir, 1990 struct inode *inode, struct ext4_dir_entry_2 *de, 1991 struct buffer_head *bh) 1992 { 1993 unsigned int blocksize = dir->i_sb->s_blocksize; 1994 int csum_size = 0; 1995 int err; 1996 1997 if (ext4_has_metadata_csum(inode->i_sb)) 1998 csum_size = sizeof(struct ext4_dir_entry_tail); 1999 2000 if (!de) { 2001 err = ext4_find_dest_de(dir, inode, bh, bh->b_data, 2002 blocksize - csum_size, fname, &de); 2003 if (err) 2004 return err; 2005 } 2006 BUFFER_TRACE(bh, "get_write_access"); 2007 err = ext4_journal_get_write_access(handle, bh); 2008 if (err) { 2009 ext4_std_error(dir->i_sb, err); 2010 return err; 2011 } 2012 2013 /* By now the buffer is marked for journaling */ 2014 ext4_insert_dentry(inode, de, blocksize, fname); 2015 2016 /* 2017 * XXX shouldn't update any times until successful 2018 * completion of syscall, but too many callers depend 2019 * on this. 2020 * 2021 * XXX similarly, too many callers depend on 2022 * ext4_new_inode() setting the times, but error 2023 * recovery deletes the inode, so the worst that can 2024 * happen is that the times are slightly out of date 2025 * and/or different from the directory change time. 2026 */ 2027 dir->i_mtime = dir->i_ctime = current_time(dir); 2028 ext4_update_dx_flag(dir); 2029 inode_inc_iversion(dir); 2030 ext4_mark_inode_dirty(handle, dir); 2031 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); 2032 err = ext4_handle_dirty_dirblock(handle, dir, bh); 2033 if (err) 2034 ext4_std_error(dir->i_sb, err); 2035 return 0; 2036 } 2037 2038 /* 2039 * This converts a one block unindexed directory to a 3 block indexed 2040 * directory, and adds the dentry to the indexed directory. 2041 */ 2042 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname, 2043 struct inode *dir, 2044 struct inode *inode, struct buffer_head *bh) 2045 { 2046 struct buffer_head *bh2; 2047 struct dx_root *root; 2048 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 2049 struct dx_entry *entries; 2050 struct ext4_dir_entry_2 *de, *de2; 2051 char *data2, *top; 2052 unsigned len; 2053 int retval; 2054 unsigned blocksize; 2055 ext4_lblk_t block; 2056 struct fake_dirent *fde; 2057 int csum_size = 0; 2058 2059 if (ext4_has_metadata_csum(inode->i_sb)) 2060 csum_size = sizeof(struct ext4_dir_entry_tail); 2061 2062 blocksize = dir->i_sb->s_blocksize; 2063 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino)); 2064 BUFFER_TRACE(bh, "get_write_access"); 2065 retval = ext4_journal_get_write_access(handle, bh); 2066 if (retval) { 2067 ext4_std_error(dir->i_sb, retval); 2068 brelse(bh); 2069 return retval; 2070 } 2071 root = (struct dx_root *) bh->b_data; 2072 2073 /* The 0th block becomes the root, move the dirents out */ 2074 fde = &root->dotdot; 2075 de = (struct ext4_dir_entry_2 *)((char *)fde + 2076 ext4_rec_len_from_disk(fde->rec_len, blocksize)); 2077 if ((char *) de >= (((char *) root) + blocksize)) { 2078 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'"); 2079 brelse(bh); 2080 return -EFSCORRUPTED; 2081 } 2082 len = ((char *) root) + (blocksize - csum_size) - (char *) de; 2083 2084 /* Allocate new block for the 0th block's dirents */ 2085 bh2 = ext4_append(handle, dir, &block); 2086 if (IS_ERR(bh2)) { 2087 brelse(bh); 2088 return PTR_ERR(bh2); 2089 } 2090 ext4_set_inode_flag(dir, EXT4_INODE_INDEX); 2091 data2 = bh2->b_data; 2092 2093 memcpy(data2, de, len); 2094 de = (struct ext4_dir_entry_2 *) data2; 2095 top = data2 + len; 2096 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top) 2097 de = de2; 2098 de->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) - 2099 (char *) de, blocksize); 2100 2101 if (csum_size) 2102 ext4_initialize_dirent_tail(bh2, blocksize); 2103 2104 /* Initialize the root; the dot dirents already exist */ 2105 de = (struct ext4_dir_entry_2 *) (&root->dotdot); 2106 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2), 2107 blocksize); 2108 memset (&root->info, 0, sizeof(root->info)); 2109 root->info.info_length = sizeof(root->info); 2110 root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version; 2111 entries = root->entries; 2112 dx_set_block(entries, 1); 2113 dx_set_count(entries, 1); 2114 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info))); 2115 2116 /* Initialize as for dx_probe */ 2117 fname->hinfo.hash_version = root->info.hash_version; 2118 if (fname->hinfo.hash_version <= DX_HASH_TEA) 2119 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; 2120 fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; 2121 ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), &fname->hinfo); 2122 2123 memset(frames, 0, sizeof(frames)); 2124 frame = frames; 2125 frame->entries = entries; 2126 frame->at = entries; 2127 frame->bh = bh; 2128 2129 retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 2130 if (retval) 2131 goto out_frames; 2132 retval = ext4_handle_dirty_dirblock(handle, dir, bh2); 2133 if (retval) 2134 goto out_frames; 2135 2136 de = do_split(handle,dir, &bh2, frame, &fname->hinfo); 2137 if (IS_ERR(de)) { 2138 retval = PTR_ERR(de); 2139 goto out_frames; 2140 } 2141 2142 retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2); 2143 out_frames: 2144 /* 2145 * Even if the block split failed, we have to properly write 2146 * out all the changes we did so far. Otherwise we can end up 2147 * with corrupted filesystem. 2148 */ 2149 if (retval) 2150 ext4_mark_inode_dirty(handle, dir); 2151 dx_release(frames); 2152 brelse(bh2); 2153 return retval; 2154 } 2155 2156 /* 2157 * ext4_add_entry() 2158 * 2159 * adds a file entry to the specified directory, using the same 2160 * semantics as ext4_find_entry(). It returns NULL if it failed. 2161 * 2162 * NOTE!! The inode part of 'de' is left at 0 - which means you 2163 * may not sleep between calling this and putting something into 2164 * the entry, as someone else might have used it while you slept. 2165 */ 2166 static int ext4_add_entry(handle_t *handle, struct dentry *dentry, 2167 struct inode *inode) 2168 { 2169 struct inode *dir = d_inode(dentry->d_parent); 2170 struct buffer_head *bh = NULL; 2171 struct ext4_dir_entry_2 *de; 2172 struct super_block *sb; 2173 #ifdef CONFIG_UNICODE 2174 struct ext4_sb_info *sbi; 2175 #endif 2176 struct ext4_filename fname; 2177 int retval; 2178 int dx_fallback=0; 2179 unsigned blocksize; 2180 ext4_lblk_t block, blocks; 2181 int csum_size = 0; 2182 2183 if (ext4_has_metadata_csum(inode->i_sb)) 2184 csum_size = sizeof(struct ext4_dir_entry_tail); 2185 2186 sb = dir->i_sb; 2187 blocksize = sb->s_blocksize; 2188 if (!dentry->d_name.len) 2189 return -EINVAL; 2190 2191 #ifdef CONFIG_UNICODE 2192 sbi = EXT4_SB(sb); 2193 if (ext4_has_strict_mode(sbi) && IS_CASEFOLDED(dir) && 2194 sbi->s_encoding && utf8_validate(sbi->s_encoding, &dentry->d_name)) 2195 return -EINVAL; 2196 #endif 2197 2198 retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname); 2199 if (retval) 2200 return retval; 2201 2202 if (ext4_has_inline_data(dir)) { 2203 retval = ext4_try_add_inline_entry(handle, &fname, dir, inode); 2204 if (retval < 0) 2205 goto out; 2206 if (retval == 1) { 2207 retval = 0; 2208 goto out; 2209 } 2210 } 2211 2212 if (is_dx(dir)) { 2213 retval = ext4_dx_add_entry(handle, &fname, dir, inode); 2214 if (!retval || (retval != ERR_BAD_DX_DIR)) 2215 goto out; 2216 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX); 2217 dx_fallback++; 2218 ext4_mark_inode_dirty(handle, dir); 2219 } 2220 blocks = dir->i_size >> sb->s_blocksize_bits; 2221 for (block = 0; block < blocks; block++) { 2222 bh = ext4_read_dirblock(dir, block, DIRENT); 2223 if (bh == NULL) { 2224 bh = ext4_bread(handle, dir, block, 2225 EXT4_GET_BLOCKS_CREATE); 2226 goto add_to_new_block; 2227 } 2228 if (IS_ERR(bh)) { 2229 retval = PTR_ERR(bh); 2230 bh = NULL; 2231 goto out; 2232 } 2233 retval = add_dirent_to_buf(handle, &fname, dir, inode, 2234 NULL, bh); 2235 if (retval != -ENOSPC) 2236 goto out; 2237 2238 if (blocks == 1 && !dx_fallback && 2239 ext4_has_feature_dir_index(sb)) { 2240 retval = make_indexed_dir(handle, &fname, dir, 2241 inode, bh); 2242 bh = NULL; /* make_indexed_dir releases bh */ 2243 goto out; 2244 } 2245 brelse(bh); 2246 } 2247 bh = ext4_append(handle, dir, &block); 2248 add_to_new_block: 2249 if (IS_ERR(bh)) { 2250 retval = PTR_ERR(bh); 2251 bh = NULL; 2252 goto out; 2253 } 2254 de = (struct ext4_dir_entry_2 *) bh->b_data; 2255 de->inode = 0; 2256 de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize); 2257 2258 if (csum_size) 2259 ext4_initialize_dirent_tail(bh, blocksize); 2260 2261 retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh); 2262 out: 2263 ext4_fname_free_filename(&fname); 2264 brelse(bh); 2265 if (retval == 0) 2266 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY); 2267 return retval; 2268 } 2269 2270 /* 2271 * Returns 0 for success, or a negative error value 2272 */ 2273 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname, 2274 struct inode *dir, struct inode *inode) 2275 { 2276 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 2277 struct dx_entry *entries, *at; 2278 struct buffer_head *bh; 2279 struct super_block *sb = dir->i_sb; 2280 struct ext4_dir_entry_2 *de; 2281 int restart; 2282 int err; 2283 2284 again: 2285 restart = 0; 2286 frame = dx_probe(fname, dir, NULL, frames); 2287 if (IS_ERR(frame)) 2288 return PTR_ERR(frame); 2289 entries = frame->entries; 2290 at = frame->at; 2291 bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT_HTREE); 2292 if (IS_ERR(bh)) { 2293 err = PTR_ERR(bh); 2294 bh = NULL; 2295 goto cleanup; 2296 } 2297 2298 BUFFER_TRACE(bh, "get_write_access"); 2299 err = ext4_journal_get_write_access(handle, bh); 2300 if (err) 2301 goto journal_error; 2302 2303 err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh); 2304 if (err != -ENOSPC) 2305 goto cleanup; 2306 2307 err = 0; 2308 /* Block full, should compress but for now just split */ 2309 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n", 2310 dx_get_count(entries), dx_get_limit(entries))); 2311 /* Need to split index? */ 2312 if (dx_get_count(entries) == dx_get_limit(entries)) { 2313 ext4_lblk_t newblock; 2314 int levels = frame - frames + 1; 2315 unsigned int icount; 2316 int add_level = 1; 2317 struct dx_entry *entries2; 2318 struct dx_node *node2; 2319 struct buffer_head *bh2; 2320 2321 while (frame > frames) { 2322 if (dx_get_count((frame - 1)->entries) < 2323 dx_get_limit((frame - 1)->entries)) { 2324 add_level = 0; 2325 break; 2326 } 2327 frame--; /* split higher index block */ 2328 at = frame->at; 2329 entries = frame->entries; 2330 restart = 1; 2331 } 2332 if (add_level && levels == ext4_dir_htree_level(sb)) { 2333 ext4_warning(sb, "Directory (ino: %lu) index full, " 2334 "reach max htree level :%d", 2335 dir->i_ino, levels); 2336 if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) { 2337 ext4_warning(sb, "Large directory feature is " 2338 "not enabled on this " 2339 "filesystem"); 2340 } 2341 err = -ENOSPC; 2342 goto cleanup; 2343 } 2344 icount = dx_get_count(entries); 2345 bh2 = ext4_append(handle, dir, &newblock); 2346 if (IS_ERR(bh2)) { 2347 err = PTR_ERR(bh2); 2348 goto cleanup; 2349 } 2350 node2 = (struct dx_node *)(bh2->b_data); 2351 entries2 = node2->entries; 2352 memset(&node2->fake, 0, sizeof(struct fake_dirent)); 2353 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize, 2354 sb->s_blocksize); 2355 BUFFER_TRACE(frame->bh, "get_write_access"); 2356 err = ext4_journal_get_write_access(handle, frame->bh); 2357 if (err) 2358 goto journal_error; 2359 if (!add_level) { 2360 unsigned icount1 = icount/2, icount2 = icount - icount1; 2361 unsigned hash2 = dx_get_hash(entries + icount1); 2362 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n", 2363 icount1, icount2)); 2364 2365 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */ 2366 err = ext4_journal_get_write_access(handle, 2367 (frame - 1)->bh); 2368 if (err) 2369 goto journal_error; 2370 2371 memcpy((char *) entries2, (char *) (entries + icount1), 2372 icount2 * sizeof(struct dx_entry)); 2373 dx_set_count(entries, icount1); 2374 dx_set_count(entries2, icount2); 2375 dx_set_limit(entries2, dx_node_limit(dir)); 2376 2377 /* Which index block gets the new entry? */ 2378 if (at - entries >= icount1) { 2379 frame->at = at = at - entries - icount1 + entries2; 2380 frame->entries = entries = entries2; 2381 swap(frame->bh, bh2); 2382 } 2383 dx_insert_block((frame - 1), hash2, newblock); 2384 dxtrace(dx_show_index("node", frame->entries)); 2385 dxtrace(dx_show_index("node", 2386 ((struct dx_node *) bh2->b_data)->entries)); 2387 err = ext4_handle_dirty_dx_node(handle, dir, bh2); 2388 if (err) 2389 goto journal_error; 2390 brelse (bh2); 2391 err = ext4_handle_dirty_dx_node(handle, dir, 2392 (frame - 1)->bh); 2393 if (err) 2394 goto journal_error; 2395 if (restart) { 2396 err = ext4_handle_dirty_dx_node(handle, dir, 2397 frame->bh); 2398 goto journal_error; 2399 } 2400 } else { 2401 struct dx_root *dxroot; 2402 memcpy((char *) entries2, (char *) entries, 2403 icount * sizeof(struct dx_entry)); 2404 dx_set_limit(entries2, dx_node_limit(dir)); 2405 2406 /* Set up root */ 2407 dx_set_count(entries, 1); 2408 dx_set_block(entries + 0, newblock); 2409 dxroot = (struct dx_root *)frames[0].bh->b_data; 2410 dxroot->info.indirect_levels += 1; 2411 dxtrace(printk(KERN_DEBUG 2412 "Creating %d level index...\n", 2413 dxroot->info.indirect_levels)); 2414 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 2415 if (err) 2416 goto journal_error; 2417 err = ext4_handle_dirty_dx_node(handle, dir, bh2); 2418 brelse(bh2); 2419 restart = 1; 2420 goto journal_error; 2421 } 2422 } 2423 de = do_split(handle, dir, &bh, frame, &fname->hinfo); 2424 if (IS_ERR(de)) { 2425 err = PTR_ERR(de); 2426 goto cleanup; 2427 } 2428 err = add_dirent_to_buf(handle, fname, dir, inode, de, bh); 2429 goto cleanup; 2430 2431 journal_error: 2432 ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */ 2433 cleanup: 2434 brelse(bh); 2435 dx_release(frames); 2436 /* @restart is true means htree-path has been changed, we need to 2437 * repeat dx_probe() to find out valid htree-path 2438 */ 2439 if (restart && err == 0) 2440 goto again; 2441 return err; 2442 } 2443 2444 /* 2445 * ext4_generic_delete_entry deletes a directory entry by merging it 2446 * with the previous entry 2447 */ 2448 int ext4_generic_delete_entry(handle_t *handle, 2449 struct inode *dir, 2450 struct ext4_dir_entry_2 *de_del, 2451 struct buffer_head *bh, 2452 void *entry_buf, 2453 int buf_size, 2454 int csum_size) 2455 { 2456 struct ext4_dir_entry_2 *de, *pde; 2457 unsigned int blocksize = dir->i_sb->s_blocksize; 2458 int i; 2459 2460 i = 0; 2461 pde = NULL; 2462 de = (struct ext4_dir_entry_2 *)entry_buf; 2463 while (i < buf_size - csum_size) { 2464 if (ext4_check_dir_entry(dir, NULL, de, bh, 2465 bh->b_data, bh->b_size, i)) 2466 return -EFSCORRUPTED; 2467 if (de == de_del) { 2468 if (pde) 2469 pde->rec_len = ext4_rec_len_to_disk( 2470 ext4_rec_len_from_disk(pde->rec_len, 2471 blocksize) + 2472 ext4_rec_len_from_disk(de->rec_len, 2473 blocksize), 2474 blocksize); 2475 else 2476 de->inode = 0; 2477 inode_inc_iversion(dir); 2478 return 0; 2479 } 2480 i += ext4_rec_len_from_disk(de->rec_len, blocksize); 2481 pde = de; 2482 de = ext4_next_entry(de, blocksize); 2483 } 2484 return -ENOENT; 2485 } 2486 2487 static int ext4_delete_entry(handle_t *handle, 2488 struct inode *dir, 2489 struct ext4_dir_entry_2 *de_del, 2490 struct buffer_head *bh) 2491 { 2492 int err, csum_size = 0; 2493 2494 if (ext4_has_inline_data(dir)) { 2495 int has_inline_data = 1; 2496 err = ext4_delete_inline_entry(handle, dir, de_del, bh, 2497 &has_inline_data); 2498 if (has_inline_data) 2499 return err; 2500 } 2501 2502 if (ext4_has_metadata_csum(dir->i_sb)) 2503 csum_size = sizeof(struct ext4_dir_entry_tail); 2504 2505 BUFFER_TRACE(bh, "get_write_access"); 2506 err = ext4_journal_get_write_access(handle, bh); 2507 if (unlikely(err)) 2508 goto out; 2509 2510 err = ext4_generic_delete_entry(handle, dir, de_del, 2511 bh, bh->b_data, 2512 dir->i_sb->s_blocksize, csum_size); 2513 if (err) 2514 goto out; 2515 2516 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); 2517 err = ext4_handle_dirty_dirblock(handle, dir, bh); 2518 if (unlikely(err)) 2519 goto out; 2520 2521 return 0; 2522 out: 2523 if (err != -ENOENT) 2524 ext4_std_error(dir->i_sb, err); 2525 return err; 2526 } 2527 2528 /* 2529 * Set directory link count to 1 if nlinks > EXT4_LINK_MAX, or if nlinks == 2 2530 * since this indicates that nlinks count was previously 1 to avoid overflowing 2531 * the 16-bit i_links_count field on disk. Directories with i_nlink == 1 mean 2532 * that subdirectory link counts are not being maintained accurately. 2533 * 2534 * The caller has already checked for i_nlink overflow in case the DIR_LINK 2535 * feature is not enabled and returned -EMLINK. The is_dx() check is a proxy 2536 * for checking S_ISDIR(inode) (since the INODE_INDEX feature will not be set 2537 * on regular files) and to avoid creating huge/slow non-HTREE directories. 2538 */ 2539 static void ext4_inc_count(handle_t *handle, struct inode *inode) 2540 { 2541 inc_nlink(inode); 2542 if (is_dx(inode) && 2543 (inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2)) 2544 set_nlink(inode, 1); 2545 } 2546 2547 /* 2548 * If a directory had nlink == 1, then we should let it be 1. This indicates 2549 * directory has >EXT4_LINK_MAX subdirs. 2550 */ 2551 static void ext4_dec_count(handle_t *handle, struct inode *inode) 2552 { 2553 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2) 2554 drop_nlink(inode); 2555 } 2556 2557 2558 /* 2559 * Add non-directory inode to a directory. On success, the inode reference is 2560 * consumed by dentry is instantiation. This is also indicated by clearing of 2561 * *inodep pointer. On failure, the caller is responsible for dropping the 2562 * inode reference in the safe context. 2563 */ 2564 static int ext4_add_nondir(handle_t *handle, 2565 struct dentry *dentry, struct inode **inodep) 2566 { 2567 struct inode *dir = d_inode(dentry->d_parent); 2568 struct inode *inode = *inodep; 2569 int err = ext4_add_entry(handle, dentry, inode); 2570 if (!err) { 2571 ext4_mark_inode_dirty(handle, inode); 2572 if (IS_DIRSYNC(dir)) 2573 ext4_handle_sync(handle); 2574 d_instantiate_new(dentry, inode); 2575 *inodep = NULL; 2576 return 0; 2577 } 2578 drop_nlink(inode); 2579 ext4_orphan_add(handle, inode); 2580 unlock_new_inode(inode); 2581 return err; 2582 } 2583 2584 /* 2585 * By the time this is called, we already have created 2586 * the directory cache entry for the new file, but it 2587 * is so far negative - it has no inode. 2588 * 2589 * If the create succeeds, we fill in the inode information 2590 * with d_instantiate(). 2591 */ 2592 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode, 2593 bool excl) 2594 { 2595 handle_t *handle; 2596 struct inode *inode; 2597 int err, credits, retries = 0; 2598 2599 err = dquot_initialize(dir); 2600 if (err) 2601 return err; 2602 2603 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2604 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2605 retry: 2606 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0, 2607 NULL, EXT4_HT_DIR, credits); 2608 handle = ext4_journal_current_handle(); 2609 err = PTR_ERR(inode); 2610 if (!IS_ERR(inode)) { 2611 inode->i_op = &ext4_file_inode_operations; 2612 inode->i_fop = &ext4_file_operations; 2613 ext4_set_aops(inode); 2614 err = ext4_add_nondir(handle, dentry, &inode); 2615 } 2616 if (handle) 2617 ext4_journal_stop(handle); 2618 if (!IS_ERR_OR_NULL(inode)) 2619 iput(inode); 2620 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2621 goto retry; 2622 return err; 2623 } 2624 2625 static int ext4_mknod(struct inode *dir, struct dentry *dentry, 2626 umode_t mode, dev_t rdev) 2627 { 2628 handle_t *handle; 2629 struct inode *inode; 2630 int err, credits, retries = 0; 2631 2632 err = dquot_initialize(dir); 2633 if (err) 2634 return err; 2635 2636 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2637 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2638 retry: 2639 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0, 2640 NULL, EXT4_HT_DIR, credits); 2641 handle = ext4_journal_current_handle(); 2642 err = PTR_ERR(inode); 2643 if (!IS_ERR(inode)) { 2644 init_special_inode(inode, inode->i_mode, rdev); 2645 inode->i_op = &ext4_special_inode_operations; 2646 err = ext4_add_nondir(handle, dentry, &inode); 2647 } 2648 if (handle) 2649 ext4_journal_stop(handle); 2650 if (!IS_ERR_OR_NULL(inode)) 2651 iput(inode); 2652 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2653 goto retry; 2654 return err; 2655 } 2656 2657 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) 2658 { 2659 handle_t *handle; 2660 struct inode *inode; 2661 int err, retries = 0; 2662 2663 err = dquot_initialize(dir); 2664 if (err) 2665 return err; 2666 2667 retry: 2668 inode = ext4_new_inode_start_handle(dir, mode, 2669 NULL, 0, NULL, 2670 EXT4_HT_DIR, 2671 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) + 2672 4 + EXT4_XATTR_TRANS_BLOCKS); 2673 handle = ext4_journal_current_handle(); 2674 err = PTR_ERR(inode); 2675 if (!IS_ERR(inode)) { 2676 inode->i_op = &ext4_file_inode_operations; 2677 inode->i_fop = &ext4_file_operations; 2678 ext4_set_aops(inode); 2679 d_tmpfile(dentry, inode); 2680 err = ext4_orphan_add(handle, inode); 2681 if (err) 2682 goto err_unlock_inode; 2683 mark_inode_dirty(inode); 2684 unlock_new_inode(inode); 2685 } 2686 if (handle) 2687 ext4_journal_stop(handle); 2688 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2689 goto retry; 2690 return err; 2691 err_unlock_inode: 2692 ext4_journal_stop(handle); 2693 unlock_new_inode(inode); 2694 return err; 2695 } 2696 2697 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode, 2698 struct ext4_dir_entry_2 *de, 2699 int blocksize, int csum_size, 2700 unsigned int parent_ino, int dotdot_real_len) 2701 { 2702 de->inode = cpu_to_le32(inode->i_ino); 2703 de->name_len = 1; 2704 de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len), 2705 blocksize); 2706 strcpy(de->name, "."); 2707 ext4_set_de_type(inode->i_sb, de, S_IFDIR); 2708 2709 de = ext4_next_entry(de, blocksize); 2710 de->inode = cpu_to_le32(parent_ino); 2711 de->name_len = 2; 2712 if (!dotdot_real_len) 2713 de->rec_len = ext4_rec_len_to_disk(blocksize - 2714 (csum_size + EXT4_DIR_REC_LEN(1)), 2715 blocksize); 2716 else 2717 de->rec_len = ext4_rec_len_to_disk( 2718 EXT4_DIR_REC_LEN(de->name_len), blocksize); 2719 strcpy(de->name, ".."); 2720 ext4_set_de_type(inode->i_sb, de, S_IFDIR); 2721 2722 return ext4_next_entry(de, blocksize); 2723 } 2724 2725 static int ext4_init_new_dir(handle_t *handle, struct inode *dir, 2726 struct inode *inode) 2727 { 2728 struct buffer_head *dir_block = NULL; 2729 struct ext4_dir_entry_2 *de; 2730 ext4_lblk_t block = 0; 2731 unsigned int blocksize = dir->i_sb->s_blocksize; 2732 int csum_size = 0; 2733 int err; 2734 2735 if (ext4_has_metadata_csum(dir->i_sb)) 2736 csum_size = sizeof(struct ext4_dir_entry_tail); 2737 2738 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) { 2739 err = ext4_try_create_inline_dir(handle, dir, inode); 2740 if (err < 0 && err != -ENOSPC) 2741 goto out; 2742 if (!err) 2743 goto out; 2744 } 2745 2746 inode->i_size = 0; 2747 dir_block = ext4_append(handle, inode, &block); 2748 if (IS_ERR(dir_block)) 2749 return PTR_ERR(dir_block); 2750 de = (struct ext4_dir_entry_2 *)dir_block->b_data; 2751 ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0); 2752 set_nlink(inode, 2); 2753 if (csum_size) 2754 ext4_initialize_dirent_tail(dir_block, blocksize); 2755 2756 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata"); 2757 err = ext4_handle_dirty_dirblock(handle, inode, dir_block); 2758 if (err) 2759 goto out; 2760 set_buffer_verified(dir_block); 2761 out: 2762 brelse(dir_block); 2763 return err; 2764 } 2765 2766 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) 2767 { 2768 handle_t *handle; 2769 struct inode *inode; 2770 int err, credits, retries = 0; 2771 2772 if (EXT4_DIR_LINK_MAX(dir)) 2773 return -EMLINK; 2774 2775 err = dquot_initialize(dir); 2776 if (err) 2777 return err; 2778 2779 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2780 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2781 retry: 2782 inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode, 2783 &dentry->d_name, 2784 0, NULL, EXT4_HT_DIR, credits); 2785 handle = ext4_journal_current_handle(); 2786 err = PTR_ERR(inode); 2787 if (IS_ERR(inode)) 2788 goto out_stop; 2789 2790 inode->i_op = &ext4_dir_inode_operations; 2791 inode->i_fop = &ext4_dir_operations; 2792 err = ext4_init_new_dir(handle, dir, inode); 2793 if (err) 2794 goto out_clear_inode; 2795 err = ext4_mark_inode_dirty(handle, inode); 2796 if (!err) 2797 err = ext4_add_entry(handle, dentry, inode); 2798 if (err) { 2799 out_clear_inode: 2800 clear_nlink(inode); 2801 ext4_orphan_add(handle, inode); 2802 unlock_new_inode(inode); 2803 ext4_mark_inode_dirty(handle, inode); 2804 ext4_journal_stop(handle); 2805 iput(inode); 2806 goto out_retry; 2807 } 2808 ext4_inc_count(handle, dir); 2809 ext4_update_dx_flag(dir); 2810 err = ext4_mark_inode_dirty(handle, dir); 2811 if (err) 2812 goto out_clear_inode; 2813 d_instantiate_new(dentry, inode); 2814 if (IS_DIRSYNC(dir)) 2815 ext4_handle_sync(handle); 2816 2817 out_stop: 2818 if (handle) 2819 ext4_journal_stop(handle); 2820 out_retry: 2821 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2822 goto retry; 2823 return err; 2824 } 2825 2826 /* 2827 * routine to check that the specified directory is empty (for rmdir) 2828 */ 2829 bool ext4_empty_dir(struct inode *inode) 2830 { 2831 unsigned int offset; 2832 struct buffer_head *bh; 2833 struct ext4_dir_entry_2 *de; 2834 struct super_block *sb; 2835 2836 if (ext4_has_inline_data(inode)) { 2837 int has_inline_data = 1; 2838 int ret; 2839 2840 ret = empty_inline_dir(inode, &has_inline_data); 2841 if (has_inline_data) 2842 return ret; 2843 } 2844 2845 sb = inode->i_sb; 2846 if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) { 2847 EXT4_ERROR_INODE(inode, "invalid size"); 2848 return true; 2849 } 2850 /* The first directory block must not be a hole, 2851 * so treat it as DIRENT_HTREE 2852 */ 2853 bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE); 2854 if (IS_ERR(bh)) 2855 return true; 2856 2857 de = (struct ext4_dir_entry_2 *) bh->b_data; 2858 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size, 2859 0) || 2860 le32_to_cpu(de->inode) != inode->i_ino || strcmp(".", de->name)) { 2861 ext4_warning_inode(inode, "directory missing '.'"); 2862 brelse(bh); 2863 return true; 2864 } 2865 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); 2866 de = ext4_next_entry(de, sb->s_blocksize); 2867 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size, 2868 offset) || 2869 le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) { 2870 ext4_warning_inode(inode, "directory missing '..'"); 2871 brelse(bh); 2872 return true; 2873 } 2874 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); 2875 while (offset < inode->i_size) { 2876 if (!(offset & (sb->s_blocksize - 1))) { 2877 unsigned int lblock; 2878 brelse(bh); 2879 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb); 2880 bh = ext4_read_dirblock(inode, lblock, EITHER); 2881 if (bh == NULL) { 2882 offset += sb->s_blocksize; 2883 continue; 2884 } 2885 if (IS_ERR(bh)) 2886 return true; 2887 } 2888 de = (struct ext4_dir_entry_2 *) (bh->b_data + 2889 (offset & (sb->s_blocksize - 1))); 2890 if (ext4_check_dir_entry(inode, NULL, de, bh, 2891 bh->b_data, bh->b_size, offset)) { 2892 offset = (offset | (sb->s_blocksize - 1)) + 1; 2893 continue; 2894 } 2895 if (le32_to_cpu(de->inode)) { 2896 brelse(bh); 2897 return false; 2898 } 2899 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); 2900 } 2901 brelse(bh); 2902 return true; 2903 } 2904 2905 /* 2906 * ext4_orphan_add() links an unlinked or truncated inode into a list of 2907 * such inodes, starting at the superblock, in case we crash before the 2908 * file is closed/deleted, or in case the inode truncate spans multiple 2909 * transactions and the last transaction is not recovered after a crash. 2910 * 2911 * At filesystem recovery time, we walk this list deleting unlinked 2912 * inodes and truncating linked inodes in ext4_orphan_cleanup(). 2913 * 2914 * Orphan list manipulation functions must be called under i_mutex unless 2915 * we are just creating the inode or deleting it. 2916 */ 2917 int ext4_orphan_add(handle_t *handle, struct inode *inode) 2918 { 2919 struct super_block *sb = inode->i_sb; 2920 struct ext4_sb_info *sbi = EXT4_SB(sb); 2921 struct ext4_iloc iloc; 2922 int err = 0, rc; 2923 bool dirty = false; 2924 2925 if (!sbi->s_journal || is_bad_inode(inode)) 2926 return 0; 2927 2928 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) && 2929 !inode_is_locked(inode)); 2930 /* 2931 * Exit early if inode already is on orphan list. This is a big speedup 2932 * since we don't have to contend on the global s_orphan_lock. 2933 */ 2934 if (!list_empty(&EXT4_I(inode)->i_orphan)) 2935 return 0; 2936 2937 /* 2938 * Orphan handling is only valid for files with data blocks 2939 * being truncated, or files being unlinked. Note that we either 2940 * hold i_mutex, or the inode can not be referenced from outside, 2941 * so i_nlink should not be bumped due to race 2942 */ 2943 J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 2944 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0); 2945 2946 BUFFER_TRACE(sbi->s_sbh, "get_write_access"); 2947 err = ext4_journal_get_write_access(handle, sbi->s_sbh); 2948 if (err) 2949 goto out; 2950 2951 err = ext4_reserve_inode_write(handle, inode, &iloc); 2952 if (err) 2953 goto out; 2954 2955 mutex_lock(&sbi->s_orphan_lock); 2956 /* 2957 * Due to previous errors inode may be already a part of on-disk 2958 * orphan list. If so skip on-disk list modification. 2959 */ 2960 if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) > 2961 (le32_to_cpu(sbi->s_es->s_inodes_count))) { 2962 /* Insert this inode at the head of the on-disk orphan list */ 2963 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan); 2964 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino); 2965 dirty = true; 2966 } 2967 list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan); 2968 mutex_unlock(&sbi->s_orphan_lock); 2969 2970 if (dirty) { 2971 err = ext4_handle_dirty_super(handle, sb); 2972 rc = ext4_mark_iloc_dirty(handle, inode, &iloc); 2973 if (!err) 2974 err = rc; 2975 if (err) { 2976 /* 2977 * We have to remove inode from in-memory list if 2978 * addition to on disk orphan list failed. Stray orphan 2979 * list entries can cause panics at unmount time. 2980 */ 2981 mutex_lock(&sbi->s_orphan_lock); 2982 list_del_init(&EXT4_I(inode)->i_orphan); 2983 mutex_unlock(&sbi->s_orphan_lock); 2984 } 2985 } else 2986 brelse(iloc.bh); 2987 2988 jbd_debug(4, "superblock will point to %lu\n", inode->i_ino); 2989 jbd_debug(4, "orphan inode %lu will point to %d\n", 2990 inode->i_ino, NEXT_ORPHAN(inode)); 2991 out: 2992 ext4_std_error(sb, err); 2993 return err; 2994 } 2995 2996 /* 2997 * ext4_orphan_del() removes an unlinked or truncated inode from the list 2998 * of such inodes stored on disk, because it is finally being cleaned up. 2999 */ 3000 int ext4_orphan_del(handle_t *handle, struct inode *inode) 3001 { 3002 struct list_head *prev; 3003 struct ext4_inode_info *ei = EXT4_I(inode); 3004 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 3005 __u32 ino_next; 3006 struct ext4_iloc iloc; 3007 int err = 0; 3008 3009 if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS)) 3010 return 0; 3011 3012 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) && 3013 !inode_is_locked(inode)); 3014 /* Do this quick check before taking global s_orphan_lock. */ 3015 if (list_empty(&ei->i_orphan)) 3016 return 0; 3017 3018 if (handle) { 3019 /* Grab inode buffer early before taking global s_orphan_lock */ 3020 err = ext4_reserve_inode_write(handle, inode, &iloc); 3021 } 3022 3023 mutex_lock(&sbi->s_orphan_lock); 3024 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino); 3025 3026 prev = ei->i_orphan.prev; 3027 list_del_init(&ei->i_orphan); 3028 3029 /* If we're on an error path, we may not have a valid 3030 * transaction handle with which to update the orphan list on 3031 * disk, but we still need to remove the inode from the linked 3032 * list in memory. */ 3033 if (!handle || err) { 3034 mutex_unlock(&sbi->s_orphan_lock); 3035 goto out_err; 3036 } 3037 3038 ino_next = NEXT_ORPHAN(inode); 3039 if (prev == &sbi->s_orphan) { 3040 jbd_debug(4, "superblock will point to %u\n", ino_next); 3041 BUFFER_TRACE(sbi->s_sbh, "get_write_access"); 3042 err = ext4_journal_get_write_access(handle, sbi->s_sbh); 3043 if (err) { 3044 mutex_unlock(&sbi->s_orphan_lock); 3045 goto out_brelse; 3046 } 3047 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next); 3048 mutex_unlock(&sbi->s_orphan_lock); 3049 err = ext4_handle_dirty_super(handle, inode->i_sb); 3050 } else { 3051 struct ext4_iloc iloc2; 3052 struct inode *i_prev = 3053 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode; 3054 3055 jbd_debug(4, "orphan inode %lu will point to %u\n", 3056 i_prev->i_ino, ino_next); 3057 err = ext4_reserve_inode_write(handle, i_prev, &iloc2); 3058 if (err) { 3059 mutex_unlock(&sbi->s_orphan_lock); 3060 goto out_brelse; 3061 } 3062 NEXT_ORPHAN(i_prev) = ino_next; 3063 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2); 3064 mutex_unlock(&sbi->s_orphan_lock); 3065 } 3066 if (err) 3067 goto out_brelse; 3068 NEXT_ORPHAN(inode) = 0; 3069 err = ext4_mark_iloc_dirty(handle, inode, &iloc); 3070 out_err: 3071 ext4_std_error(inode->i_sb, err); 3072 return err; 3073 3074 out_brelse: 3075 brelse(iloc.bh); 3076 goto out_err; 3077 } 3078 3079 static int ext4_rmdir(struct inode *dir, struct dentry *dentry) 3080 { 3081 int retval; 3082 struct inode *inode; 3083 struct buffer_head *bh; 3084 struct ext4_dir_entry_2 *de; 3085 handle_t *handle = NULL; 3086 3087 if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb)))) 3088 return -EIO; 3089 3090 /* Initialize quotas before so that eventual writes go in 3091 * separate transaction */ 3092 retval = dquot_initialize(dir); 3093 if (retval) 3094 return retval; 3095 retval = dquot_initialize(d_inode(dentry)); 3096 if (retval) 3097 return retval; 3098 3099 retval = -ENOENT; 3100 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); 3101 if (IS_ERR(bh)) 3102 return PTR_ERR(bh); 3103 if (!bh) 3104 goto end_rmdir; 3105 3106 inode = d_inode(dentry); 3107 3108 retval = -EFSCORRUPTED; 3109 if (le32_to_cpu(de->inode) != inode->i_ino) 3110 goto end_rmdir; 3111 3112 retval = -ENOTEMPTY; 3113 if (!ext4_empty_dir(inode)) 3114 goto end_rmdir; 3115 3116 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3117 EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); 3118 if (IS_ERR(handle)) { 3119 retval = PTR_ERR(handle); 3120 handle = NULL; 3121 goto end_rmdir; 3122 } 3123 3124 if (IS_DIRSYNC(dir)) 3125 ext4_handle_sync(handle); 3126 3127 retval = ext4_delete_entry(handle, dir, de, bh); 3128 if (retval) 3129 goto end_rmdir; 3130 if (!EXT4_DIR_LINK_EMPTY(inode)) 3131 ext4_warning_inode(inode, 3132 "empty directory '%.*s' has too many links (%u)", 3133 dentry->d_name.len, dentry->d_name.name, 3134 inode->i_nlink); 3135 inode_inc_iversion(inode); 3136 clear_nlink(inode); 3137 /* There's no need to set i_disksize: the fact that i_nlink is 3138 * zero will ensure that the right thing happens during any 3139 * recovery. */ 3140 inode->i_size = 0; 3141 ext4_orphan_add(handle, inode); 3142 inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode); 3143 ext4_mark_inode_dirty(handle, inode); 3144 ext4_dec_count(handle, dir); 3145 ext4_update_dx_flag(dir); 3146 ext4_mark_inode_dirty(handle, dir); 3147 3148 #ifdef CONFIG_UNICODE 3149 /* VFS negative dentries are incompatible with Encoding and 3150 * Case-insensitiveness. Eventually we'll want avoid 3151 * invalidating the dentries here, alongside with returning the 3152 * negative dentries at ext4_lookup(), when it is better 3153 * supported by the VFS for the CI case. 3154 */ 3155 if (IS_CASEFOLDED(dir)) 3156 d_invalidate(dentry); 3157 #endif 3158 3159 end_rmdir: 3160 brelse(bh); 3161 if (handle) 3162 ext4_journal_stop(handle); 3163 return retval; 3164 } 3165 3166 static int ext4_unlink(struct inode *dir, struct dentry *dentry) 3167 { 3168 int retval; 3169 struct inode *inode; 3170 struct buffer_head *bh; 3171 struct ext4_dir_entry_2 *de; 3172 handle_t *handle = NULL; 3173 3174 if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb)))) 3175 return -EIO; 3176 3177 trace_ext4_unlink_enter(dir, dentry); 3178 /* Initialize quotas before so that eventual writes go 3179 * in separate transaction */ 3180 retval = dquot_initialize(dir); 3181 if (retval) 3182 return retval; 3183 retval = dquot_initialize(d_inode(dentry)); 3184 if (retval) 3185 return retval; 3186 3187 retval = -ENOENT; 3188 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); 3189 if (IS_ERR(bh)) 3190 return PTR_ERR(bh); 3191 if (!bh) 3192 goto end_unlink; 3193 3194 inode = d_inode(dentry); 3195 3196 retval = -EFSCORRUPTED; 3197 if (le32_to_cpu(de->inode) != inode->i_ino) 3198 goto end_unlink; 3199 3200 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3201 EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); 3202 if (IS_ERR(handle)) { 3203 retval = PTR_ERR(handle); 3204 handle = NULL; 3205 goto end_unlink; 3206 } 3207 3208 if (IS_DIRSYNC(dir)) 3209 ext4_handle_sync(handle); 3210 3211 retval = ext4_delete_entry(handle, dir, de, bh); 3212 if (retval) 3213 goto end_unlink; 3214 dir->i_ctime = dir->i_mtime = current_time(dir); 3215 ext4_update_dx_flag(dir); 3216 ext4_mark_inode_dirty(handle, dir); 3217 if (inode->i_nlink == 0) 3218 ext4_warning_inode(inode, "Deleting file '%.*s' with no links", 3219 dentry->d_name.len, dentry->d_name.name); 3220 else 3221 drop_nlink(inode); 3222 if (!inode->i_nlink) 3223 ext4_orphan_add(handle, inode); 3224 inode->i_ctime = current_time(inode); 3225 ext4_mark_inode_dirty(handle, inode); 3226 3227 #ifdef CONFIG_UNICODE 3228 /* VFS negative dentries are incompatible with Encoding and 3229 * Case-insensitiveness. Eventually we'll want avoid 3230 * invalidating the dentries here, alongside with returning the 3231 * negative dentries at ext4_lookup(), when it is better 3232 * supported by the VFS for the CI case. 3233 */ 3234 if (IS_CASEFOLDED(dir)) 3235 d_invalidate(dentry); 3236 #endif 3237 3238 end_unlink: 3239 brelse(bh); 3240 if (handle) 3241 ext4_journal_stop(handle); 3242 trace_ext4_unlink_exit(dentry, retval); 3243 return retval; 3244 } 3245 3246 static int ext4_symlink(struct inode *dir, 3247 struct dentry *dentry, const char *symname) 3248 { 3249 handle_t *handle; 3250 struct inode *inode; 3251 int err, len = strlen(symname); 3252 int credits; 3253 struct fscrypt_str disk_link; 3254 3255 if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb)))) 3256 return -EIO; 3257 3258 err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize, 3259 &disk_link); 3260 if (err) 3261 return err; 3262 3263 err = dquot_initialize(dir); 3264 if (err) 3265 return err; 3266 3267 if ((disk_link.len > EXT4_N_BLOCKS * 4)) { 3268 /* 3269 * For non-fast symlinks, we just allocate inode and put it on 3270 * orphan list in the first transaction => we need bitmap, 3271 * group descriptor, sb, inode block, quota blocks, and 3272 * possibly selinux xattr blocks. 3273 */ 3274 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) + 3275 EXT4_XATTR_TRANS_BLOCKS; 3276 } else { 3277 /* 3278 * Fast symlink. We have to add entry to directory 3279 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS), 3280 * allocate new inode (bitmap, group descriptor, inode block, 3281 * quota blocks, sb is already counted in previous macros). 3282 */ 3283 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3284 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3; 3285 } 3286 3287 inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO, 3288 &dentry->d_name, 0, NULL, 3289 EXT4_HT_DIR, credits); 3290 handle = ext4_journal_current_handle(); 3291 if (IS_ERR(inode)) { 3292 if (handle) 3293 ext4_journal_stop(handle); 3294 return PTR_ERR(inode); 3295 } 3296 3297 if (IS_ENCRYPTED(inode)) { 3298 err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link); 3299 if (err) 3300 goto err_drop_inode; 3301 inode->i_op = &ext4_encrypted_symlink_inode_operations; 3302 } 3303 3304 if ((disk_link.len > EXT4_N_BLOCKS * 4)) { 3305 if (!IS_ENCRYPTED(inode)) 3306 inode->i_op = &ext4_symlink_inode_operations; 3307 inode_nohighmem(inode); 3308 ext4_set_aops(inode); 3309 /* 3310 * We cannot call page_symlink() with transaction started 3311 * because it calls into ext4_write_begin() which can wait 3312 * for transaction commit if we are running out of space 3313 * and thus we deadlock. So we have to stop transaction now 3314 * and restart it when symlink contents is written. 3315 * 3316 * To keep fs consistent in case of crash, we have to put inode 3317 * to orphan list in the mean time. 3318 */ 3319 drop_nlink(inode); 3320 err = ext4_orphan_add(handle, inode); 3321 ext4_journal_stop(handle); 3322 handle = NULL; 3323 if (err) 3324 goto err_drop_inode; 3325 err = __page_symlink(inode, disk_link.name, disk_link.len, 1); 3326 if (err) 3327 goto err_drop_inode; 3328 /* 3329 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS 3330 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified 3331 */ 3332 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3333 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3334 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1); 3335 if (IS_ERR(handle)) { 3336 err = PTR_ERR(handle); 3337 handle = NULL; 3338 goto err_drop_inode; 3339 } 3340 set_nlink(inode, 1); 3341 err = ext4_orphan_del(handle, inode); 3342 if (err) 3343 goto err_drop_inode; 3344 } else { 3345 /* clear the extent format for fast symlink */ 3346 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS); 3347 if (!IS_ENCRYPTED(inode)) { 3348 inode->i_op = &ext4_fast_symlink_inode_operations; 3349 inode->i_link = (char *)&EXT4_I(inode)->i_data; 3350 } 3351 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name, 3352 disk_link.len); 3353 inode->i_size = disk_link.len - 1; 3354 } 3355 EXT4_I(inode)->i_disksize = inode->i_size; 3356 err = ext4_add_nondir(handle, dentry, &inode); 3357 if (handle) 3358 ext4_journal_stop(handle); 3359 if (inode) 3360 iput(inode); 3361 goto out_free_encrypted_link; 3362 3363 err_drop_inode: 3364 if (handle) 3365 ext4_journal_stop(handle); 3366 clear_nlink(inode); 3367 unlock_new_inode(inode); 3368 iput(inode); 3369 out_free_encrypted_link: 3370 if (disk_link.name != (unsigned char *)symname) 3371 kfree(disk_link.name); 3372 return err; 3373 } 3374 3375 static int ext4_link(struct dentry *old_dentry, 3376 struct inode *dir, struct dentry *dentry) 3377 { 3378 handle_t *handle; 3379 struct inode *inode = d_inode(old_dentry); 3380 int err, retries = 0; 3381 3382 if (inode->i_nlink >= EXT4_LINK_MAX) 3383 return -EMLINK; 3384 3385 err = fscrypt_prepare_link(old_dentry, dir, dentry); 3386 if (err) 3387 return err; 3388 3389 if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) && 3390 (!projid_eq(EXT4_I(dir)->i_projid, 3391 EXT4_I(old_dentry->d_inode)->i_projid))) 3392 return -EXDEV; 3393 3394 err = dquot_initialize(dir); 3395 if (err) 3396 return err; 3397 3398 retry: 3399 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3400 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3401 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1); 3402 if (IS_ERR(handle)) 3403 return PTR_ERR(handle); 3404 3405 if (IS_DIRSYNC(dir)) 3406 ext4_handle_sync(handle); 3407 3408 inode->i_ctime = current_time(inode); 3409 ext4_inc_count(handle, inode); 3410 ihold(inode); 3411 3412 err = ext4_add_entry(handle, dentry, inode); 3413 if (!err) { 3414 ext4_mark_inode_dirty(handle, inode); 3415 /* this can happen only for tmpfile being 3416 * linked the first time 3417 */ 3418 if (inode->i_nlink == 1) 3419 ext4_orphan_del(handle, inode); 3420 d_instantiate(dentry, inode); 3421 } else { 3422 drop_nlink(inode); 3423 iput(inode); 3424 } 3425 ext4_journal_stop(handle); 3426 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 3427 goto retry; 3428 return err; 3429 } 3430 3431 3432 /* 3433 * Try to find buffer head where contains the parent block. 3434 * It should be the inode block if it is inlined or the 1st block 3435 * if it is a normal dir. 3436 */ 3437 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle, 3438 struct inode *inode, 3439 int *retval, 3440 struct ext4_dir_entry_2 **parent_de, 3441 int *inlined) 3442 { 3443 struct buffer_head *bh; 3444 3445 if (!ext4_has_inline_data(inode)) { 3446 /* The first directory block must not be a hole, so 3447 * treat it as DIRENT_HTREE 3448 */ 3449 bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE); 3450 if (IS_ERR(bh)) { 3451 *retval = PTR_ERR(bh); 3452 return NULL; 3453 } 3454 *parent_de = ext4_next_entry( 3455 (struct ext4_dir_entry_2 *)bh->b_data, 3456 inode->i_sb->s_blocksize); 3457 return bh; 3458 } 3459 3460 *inlined = 1; 3461 return ext4_get_first_inline_block(inode, parent_de, retval); 3462 } 3463 3464 struct ext4_renament { 3465 struct inode *dir; 3466 struct dentry *dentry; 3467 struct inode *inode; 3468 bool is_dir; 3469 int dir_nlink_delta; 3470 3471 /* entry for "dentry" */ 3472 struct buffer_head *bh; 3473 struct ext4_dir_entry_2 *de; 3474 int inlined; 3475 3476 /* entry for ".." in inode if it's a directory */ 3477 struct buffer_head *dir_bh; 3478 struct ext4_dir_entry_2 *parent_de; 3479 int dir_inlined; 3480 }; 3481 3482 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent) 3483 { 3484 int retval; 3485 3486 ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode, 3487 &retval, &ent->parent_de, 3488 &ent->dir_inlined); 3489 if (!ent->dir_bh) 3490 return retval; 3491 if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino) 3492 return -EFSCORRUPTED; 3493 BUFFER_TRACE(ent->dir_bh, "get_write_access"); 3494 return ext4_journal_get_write_access(handle, ent->dir_bh); 3495 } 3496 3497 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent, 3498 unsigned dir_ino) 3499 { 3500 int retval; 3501 3502 ent->parent_de->inode = cpu_to_le32(dir_ino); 3503 BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata"); 3504 if (!ent->dir_inlined) { 3505 if (is_dx(ent->inode)) { 3506 retval = ext4_handle_dirty_dx_node(handle, 3507 ent->inode, 3508 ent->dir_bh); 3509 } else { 3510 retval = ext4_handle_dirty_dirblock(handle, ent->inode, 3511 ent->dir_bh); 3512 } 3513 } else { 3514 retval = ext4_mark_inode_dirty(handle, ent->inode); 3515 } 3516 if (retval) { 3517 ext4_std_error(ent->dir->i_sb, retval); 3518 return retval; 3519 } 3520 return 0; 3521 } 3522 3523 static int ext4_setent(handle_t *handle, struct ext4_renament *ent, 3524 unsigned ino, unsigned file_type) 3525 { 3526 int retval; 3527 3528 BUFFER_TRACE(ent->bh, "get write access"); 3529 retval = ext4_journal_get_write_access(handle, ent->bh); 3530 if (retval) 3531 return retval; 3532 ent->de->inode = cpu_to_le32(ino); 3533 if (ext4_has_feature_filetype(ent->dir->i_sb)) 3534 ent->de->file_type = file_type; 3535 inode_inc_iversion(ent->dir); 3536 ent->dir->i_ctime = ent->dir->i_mtime = 3537 current_time(ent->dir); 3538 ext4_mark_inode_dirty(handle, ent->dir); 3539 BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata"); 3540 if (!ent->inlined) { 3541 retval = ext4_handle_dirty_dirblock(handle, ent->dir, ent->bh); 3542 if (unlikely(retval)) { 3543 ext4_std_error(ent->dir->i_sb, retval); 3544 return retval; 3545 } 3546 } 3547 brelse(ent->bh); 3548 ent->bh = NULL; 3549 3550 return 0; 3551 } 3552 3553 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir, 3554 const struct qstr *d_name) 3555 { 3556 int retval = -ENOENT; 3557 struct buffer_head *bh; 3558 struct ext4_dir_entry_2 *de; 3559 3560 bh = ext4_find_entry(dir, d_name, &de, NULL); 3561 if (IS_ERR(bh)) 3562 return PTR_ERR(bh); 3563 if (bh) { 3564 retval = ext4_delete_entry(handle, dir, de, bh); 3565 brelse(bh); 3566 } 3567 return retval; 3568 } 3569 3570 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent, 3571 int force_reread) 3572 { 3573 int retval; 3574 /* 3575 * ent->de could have moved from under us during htree split, so make 3576 * sure that we are deleting the right entry. We might also be pointing 3577 * to a stale entry in the unused part of ent->bh so just checking inum 3578 * and the name isn't enough. 3579 */ 3580 if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino || 3581 ent->de->name_len != ent->dentry->d_name.len || 3582 strncmp(ent->de->name, ent->dentry->d_name.name, 3583 ent->de->name_len) || 3584 force_reread) { 3585 retval = ext4_find_delete_entry(handle, ent->dir, 3586 &ent->dentry->d_name); 3587 } else { 3588 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh); 3589 if (retval == -ENOENT) { 3590 retval = ext4_find_delete_entry(handle, ent->dir, 3591 &ent->dentry->d_name); 3592 } 3593 } 3594 3595 if (retval) { 3596 ext4_warning_inode(ent->dir, 3597 "Deleting old file: nlink %d, error=%d", 3598 ent->dir->i_nlink, retval); 3599 } 3600 } 3601 3602 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent) 3603 { 3604 if (ent->dir_nlink_delta) { 3605 if (ent->dir_nlink_delta == -1) 3606 ext4_dec_count(handle, ent->dir); 3607 else 3608 ext4_inc_count(handle, ent->dir); 3609 ext4_mark_inode_dirty(handle, ent->dir); 3610 } 3611 } 3612 3613 static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent, 3614 int credits, handle_t **h) 3615 { 3616 struct inode *wh; 3617 handle_t *handle; 3618 int retries = 0; 3619 3620 /* 3621 * for inode block, sb block, group summaries, 3622 * and inode bitmap 3623 */ 3624 credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) + 3625 EXT4_XATTR_TRANS_BLOCKS + 4); 3626 retry: 3627 wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE, 3628 &ent->dentry->d_name, 0, NULL, 3629 EXT4_HT_DIR, credits); 3630 3631 handle = ext4_journal_current_handle(); 3632 if (IS_ERR(wh)) { 3633 if (handle) 3634 ext4_journal_stop(handle); 3635 if (PTR_ERR(wh) == -ENOSPC && 3636 ext4_should_retry_alloc(ent->dir->i_sb, &retries)) 3637 goto retry; 3638 } else { 3639 *h = handle; 3640 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV); 3641 wh->i_op = &ext4_special_inode_operations; 3642 } 3643 return wh; 3644 } 3645 3646 /* 3647 * Anybody can rename anything with this: the permission checks are left to the 3648 * higher-level routines. 3649 * 3650 * n.b. old_{dentry,inode) refers to the source dentry/inode 3651 * while new_{dentry,inode) refers to the destination dentry/inode 3652 * This comes from rename(const char *oldpath, const char *newpath) 3653 */ 3654 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry, 3655 struct inode *new_dir, struct dentry *new_dentry, 3656 unsigned int flags) 3657 { 3658 handle_t *handle = NULL; 3659 struct ext4_renament old = { 3660 .dir = old_dir, 3661 .dentry = old_dentry, 3662 .inode = d_inode(old_dentry), 3663 }; 3664 struct ext4_renament new = { 3665 .dir = new_dir, 3666 .dentry = new_dentry, 3667 .inode = d_inode(new_dentry), 3668 }; 3669 int force_reread; 3670 int retval; 3671 struct inode *whiteout = NULL; 3672 int credits; 3673 u8 old_file_type; 3674 3675 if (new.inode && new.inode->i_nlink == 0) { 3676 EXT4_ERROR_INODE(new.inode, 3677 "target of rename is already freed"); 3678 return -EFSCORRUPTED; 3679 } 3680 3681 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) && 3682 (!projid_eq(EXT4_I(new_dir)->i_projid, 3683 EXT4_I(old_dentry->d_inode)->i_projid))) 3684 return -EXDEV; 3685 3686 retval = dquot_initialize(old.dir); 3687 if (retval) 3688 return retval; 3689 retval = dquot_initialize(new.dir); 3690 if (retval) 3691 return retval; 3692 3693 /* Initialize quotas before so that eventual writes go 3694 * in separate transaction */ 3695 if (new.inode) { 3696 retval = dquot_initialize(new.inode); 3697 if (retval) 3698 return retval; 3699 } 3700 3701 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL); 3702 if (IS_ERR(old.bh)) 3703 return PTR_ERR(old.bh); 3704 /* 3705 * Check for inode number is _not_ due to possible IO errors. 3706 * We might rmdir the source, keep it as pwd of some process 3707 * and merrily kill the link to whatever was created under the 3708 * same name. Goodbye sticky bit ;-< 3709 */ 3710 retval = -ENOENT; 3711 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino) 3712 goto end_rename; 3713 3714 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, 3715 &new.de, &new.inlined); 3716 if (IS_ERR(new.bh)) { 3717 retval = PTR_ERR(new.bh); 3718 new.bh = NULL; 3719 goto end_rename; 3720 } 3721 if (new.bh) { 3722 if (!new.inode) { 3723 brelse(new.bh); 3724 new.bh = NULL; 3725 } 3726 } 3727 if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC)) 3728 ext4_alloc_da_blocks(old.inode); 3729 3730 credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + 3731 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2); 3732 if (!(flags & RENAME_WHITEOUT)) { 3733 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits); 3734 if (IS_ERR(handle)) { 3735 retval = PTR_ERR(handle); 3736 handle = NULL; 3737 goto end_rename; 3738 } 3739 } else { 3740 whiteout = ext4_whiteout_for_rename(&old, credits, &handle); 3741 if (IS_ERR(whiteout)) { 3742 retval = PTR_ERR(whiteout); 3743 whiteout = NULL; 3744 goto end_rename; 3745 } 3746 } 3747 3748 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir)) 3749 ext4_handle_sync(handle); 3750 3751 if (S_ISDIR(old.inode->i_mode)) { 3752 if (new.inode) { 3753 retval = -ENOTEMPTY; 3754 if (!ext4_empty_dir(new.inode)) 3755 goto end_rename; 3756 } else { 3757 retval = -EMLINK; 3758 if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir)) 3759 goto end_rename; 3760 } 3761 retval = ext4_rename_dir_prepare(handle, &old); 3762 if (retval) 3763 goto end_rename; 3764 } 3765 /* 3766 * If we're renaming a file within an inline_data dir and adding or 3767 * setting the new dirent causes a conversion from inline_data to 3768 * extents/blockmap, we need to force the dirent delete code to 3769 * re-read the directory, or else we end up trying to delete a dirent 3770 * from what is now the extent tree root (or a block map). 3771 */ 3772 force_reread = (new.dir->i_ino == old.dir->i_ino && 3773 ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA)); 3774 3775 old_file_type = old.de->file_type; 3776 if (whiteout) { 3777 /* 3778 * Do this before adding a new entry, so the old entry is sure 3779 * to be still pointing to the valid old entry. 3780 */ 3781 retval = ext4_setent(handle, &old, whiteout->i_ino, 3782 EXT4_FT_CHRDEV); 3783 if (retval) 3784 goto end_rename; 3785 ext4_mark_inode_dirty(handle, whiteout); 3786 } 3787 if (!new.bh) { 3788 retval = ext4_add_entry(handle, new.dentry, old.inode); 3789 if (retval) 3790 goto end_rename; 3791 } else { 3792 retval = ext4_setent(handle, &new, 3793 old.inode->i_ino, old_file_type); 3794 if (retval) 3795 goto end_rename; 3796 } 3797 if (force_reread) 3798 force_reread = !ext4_test_inode_flag(new.dir, 3799 EXT4_INODE_INLINE_DATA); 3800 3801 /* 3802 * Like most other Unix systems, set the ctime for inodes on a 3803 * rename. 3804 */ 3805 old.inode->i_ctime = current_time(old.inode); 3806 ext4_mark_inode_dirty(handle, old.inode); 3807 3808 if (!whiteout) { 3809 /* 3810 * ok, that's it 3811 */ 3812 ext4_rename_delete(handle, &old, force_reread); 3813 } 3814 3815 if (new.inode) { 3816 ext4_dec_count(handle, new.inode); 3817 new.inode->i_ctime = current_time(new.inode); 3818 } 3819 old.dir->i_ctime = old.dir->i_mtime = current_time(old.dir); 3820 ext4_update_dx_flag(old.dir); 3821 if (old.dir_bh) { 3822 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); 3823 if (retval) 3824 goto end_rename; 3825 3826 ext4_dec_count(handle, old.dir); 3827 if (new.inode) { 3828 /* checked ext4_empty_dir above, can't have another 3829 * parent, ext4_dec_count() won't work for many-linked 3830 * dirs */ 3831 clear_nlink(new.inode); 3832 } else { 3833 ext4_inc_count(handle, new.dir); 3834 ext4_update_dx_flag(new.dir); 3835 ext4_mark_inode_dirty(handle, new.dir); 3836 } 3837 } 3838 ext4_mark_inode_dirty(handle, old.dir); 3839 if (new.inode) { 3840 ext4_mark_inode_dirty(handle, new.inode); 3841 if (!new.inode->i_nlink) 3842 ext4_orphan_add(handle, new.inode); 3843 } 3844 retval = 0; 3845 3846 end_rename: 3847 brelse(old.dir_bh); 3848 brelse(old.bh); 3849 brelse(new.bh); 3850 if (whiteout) { 3851 if (retval) 3852 drop_nlink(whiteout); 3853 unlock_new_inode(whiteout); 3854 iput(whiteout); 3855 } 3856 if (handle) 3857 ext4_journal_stop(handle); 3858 return retval; 3859 } 3860 3861 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry, 3862 struct inode *new_dir, struct dentry *new_dentry) 3863 { 3864 handle_t *handle = NULL; 3865 struct ext4_renament old = { 3866 .dir = old_dir, 3867 .dentry = old_dentry, 3868 .inode = d_inode(old_dentry), 3869 }; 3870 struct ext4_renament new = { 3871 .dir = new_dir, 3872 .dentry = new_dentry, 3873 .inode = d_inode(new_dentry), 3874 }; 3875 u8 new_file_type; 3876 int retval; 3877 struct timespec64 ctime; 3878 3879 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) && 3880 !projid_eq(EXT4_I(new_dir)->i_projid, 3881 EXT4_I(old_dentry->d_inode)->i_projid)) || 3882 (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) && 3883 !projid_eq(EXT4_I(old_dir)->i_projid, 3884 EXT4_I(new_dentry->d_inode)->i_projid))) 3885 return -EXDEV; 3886 3887 retval = dquot_initialize(old.dir); 3888 if (retval) 3889 return retval; 3890 retval = dquot_initialize(new.dir); 3891 if (retval) 3892 return retval; 3893 3894 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, 3895 &old.de, &old.inlined); 3896 if (IS_ERR(old.bh)) 3897 return PTR_ERR(old.bh); 3898 /* 3899 * Check for inode number is _not_ due to possible IO errors. 3900 * We might rmdir the source, keep it as pwd of some process 3901 * and merrily kill the link to whatever was created under the 3902 * same name. Goodbye sticky bit ;-< 3903 */ 3904 retval = -ENOENT; 3905 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino) 3906 goto end_rename; 3907 3908 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, 3909 &new.de, &new.inlined); 3910 if (IS_ERR(new.bh)) { 3911 retval = PTR_ERR(new.bh); 3912 new.bh = NULL; 3913 goto end_rename; 3914 } 3915 3916 /* RENAME_EXCHANGE case: old *and* new must both exist */ 3917 if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino) 3918 goto end_rename; 3919 3920 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, 3921 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + 3922 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2)); 3923 if (IS_ERR(handle)) { 3924 retval = PTR_ERR(handle); 3925 handle = NULL; 3926 goto end_rename; 3927 } 3928 3929 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir)) 3930 ext4_handle_sync(handle); 3931 3932 if (S_ISDIR(old.inode->i_mode)) { 3933 old.is_dir = true; 3934 retval = ext4_rename_dir_prepare(handle, &old); 3935 if (retval) 3936 goto end_rename; 3937 } 3938 if (S_ISDIR(new.inode->i_mode)) { 3939 new.is_dir = true; 3940 retval = ext4_rename_dir_prepare(handle, &new); 3941 if (retval) 3942 goto end_rename; 3943 } 3944 3945 /* 3946 * Other than the special case of overwriting a directory, parents' 3947 * nlink only needs to be modified if this is a cross directory rename. 3948 */ 3949 if (old.dir != new.dir && old.is_dir != new.is_dir) { 3950 old.dir_nlink_delta = old.is_dir ? -1 : 1; 3951 new.dir_nlink_delta = -old.dir_nlink_delta; 3952 retval = -EMLINK; 3953 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) || 3954 (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir))) 3955 goto end_rename; 3956 } 3957 3958 new_file_type = new.de->file_type; 3959 retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type); 3960 if (retval) 3961 goto end_rename; 3962 3963 retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type); 3964 if (retval) 3965 goto end_rename; 3966 3967 /* 3968 * Like most other Unix systems, set the ctime for inodes on a 3969 * rename. 3970 */ 3971 ctime = current_time(old.inode); 3972 old.inode->i_ctime = ctime; 3973 new.inode->i_ctime = ctime; 3974 ext4_mark_inode_dirty(handle, old.inode); 3975 ext4_mark_inode_dirty(handle, new.inode); 3976 3977 if (old.dir_bh) { 3978 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); 3979 if (retval) 3980 goto end_rename; 3981 } 3982 if (new.dir_bh) { 3983 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino); 3984 if (retval) 3985 goto end_rename; 3986 } 3987 ext4_update_dir_count(handle, &old); 3988 ext4_update_dir_count(handle, &new); 3989 retval = 0; 3990 3991 end_rename: 3992 brelse(old.dir_bh); 3993 brelse(new.dir_bh); 3994 brelse(old.bh); 3995 brelse(new.bh); 3996 if (handle) 3997 ext4_journal_stop(handle); 3998 return retval; 3999 } 4000 4001 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry, 4002 struct inode *new_dir, struct dentry *new_dentry, 4003 unsigned int flags) 4004 { 4005 int err; 4006 4007 if (unlikely(ext4_forced_shutdown(EXT4_SB(old_dir->i_sb)))) 4008 return -EIO; 4009 4010 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT)) 4011 return -EINVAL; 4012 4013 err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry, 4014 flags); 4015 if (err) 4016 return err; 4017 4018 if (flags & RENAME_EXCHANGE) { 4019 return ext4_cross_rename(old_dir, old_dentry, 4020 new_dir, new_dentry); 4021 } 4022 4023 return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags); 4024 } 4025 4026 /* 4027 * directories can handle most operations... 4028 */ 4029 const struct inode_operations ext4_dir_inode_operations = { 4030 .create = ext4_create, 4031 .lookup = ext4_lookup, 4032 .link = ext4_link, 4033 .unlink = ext4_unlink, 4034 .symlink = ext4_symlink, 4035 .mkdir = ext4_mkdir, 4036 .rmdir = ext4_rmdir, 4037 .mknod = ext4_mknod, 4038 .tmpfile = ext4_tmpfile, 4039 .rename = ext4_rename2, 4040 .setattr = ext4_setattr, 4041 .getattr = ext4_getattr, 4042 .listxattr = ext4_listxattr, 4043 .get_acl = ext4_get_acl, 4044 .set_acl = ext4_set_acl, 4045 .fiemap = ext4_fiemap, 4046 }; 4047 4048 const struct inode_operations ext4_special_inode_operations = { 4049 .setattr = ext4_setattr, 4050 .getattr = ext4_getattr, 4051 .listxattr = ext4_listxattr, 4052 .get_acl = ext4_get_acl, 4053 .set_acl = ext4_set_acl, 4054 }; 4055