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_error_inode_err(inode, func, line, block, 164 EFSBADCRC, 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_error_inode_err(inode, func, line, block, 176 EFSBADCRC, 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[]; 237 }; 238 239 struct dx_node 240 { 241 struct fake_dirent fake; 242 struct dx_entry entries[]; 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 /* Directory is not encrypted */ 648 ext4fs_dirhash(dir, de->name, 649 de->name_len, &h); 650 printk("%*.s:(U)%x.%u ", len, 651 name, h.hash, 652 (unsigned) ((char *) de 653 - base)); 654 } else { 655 struct fscrypt_str de_name = 656 FSTR_INIT(name, len); 657 658 /* Directory is encrypted */ 659 res = fscrypt_fname_alloc_buffer( 660 len, &fname_crypto_str); 661 if (res) 662 printk(KERN_WARNING "Error " 663 "allocating crypto " 664 "buffer--skipping " 665 "crypto\n"); 666 res = fscrypt_fname_disk_to_usr(dir, 667 0, 0, &de_name, 668 &fname_crypto_str); 669 if (res) { 670 printk(KERN_WARNING "Error " 671 "converting filename " 672 "from disk to usr" 673 "\n"); 674 name = "??"; 675 len = 2; 676 } else { 677 name = fname_crypto_str.name; 678 len = fname_crypto_str.len; 679 } 680 ext4fs_dirhash(dir, de->name, 681 de->name_len, &h); 682 printk("%*.s:(E)%x.%u ", len, name, 683 h.hash, (unsigned) ((char *) de 684 - base)); 685 fscrypt_fname_free_buffer( 686 &fname_crypto_str); 687 } 688 #else 689 int len = de->name_len; 690 char *name = de->name; 691 ext4fs_dirhash(dir, de->name, de->name_len, &h); 692 printk("%*.s:%x.%u ", len, name, h.hash, 693 (unsigned) ((char *) de - base)); 694 #endif 695 } 696 space += EXT4_DIR_REC_LEN(de->name_len); 697 names++; 698 } 699 de = ext4_next_entry(de, size); 700 } 701 printk(KERN_CONT "(%i)\n", names); 702 return (struct stats) { names, space, 1 }; 703 } 704 705 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir, 706 struct dx_entry *entries, int levels) 707 { 708 unsigned blocksize = dir->i_sb->s_blocksize; 709 unsigned count = dx_get_count(entries), names = 0, space = 0, i; 710 unsigned bcount = 0; 711 struct buffer_head *bh; 712 printk("%i indexed blocks...\n", count); 713 for (i = 0; i < count; i++, entries++) 714 { 715 ext4_lblk_t block = dx_get_block(entries); 716 ext4_lblk_t hash = i ? dx_get_hash(entries): 0; 717 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash; 718 struct stats stats; 719 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range); 720 bh = ext4_bread(NULL,dir, block, 0); 721 if (!bh || IS_ERR(bh)) 722 continue; 723 stats = levels? 724 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1): 725 dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) 726 bh->b_data, blocksize, 0); 727 names += stats.names; 728 space += stats.space; 729 bcount += stats.bcount; 730 brelse(bh); 731 } 732 if (bcount) 733 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n", 734 levels ? "" : " ", names, space/bcount, 735 (space/bcount)*100/blocksize); 736 return (struct stats) { names, space, bcount}; 737 } 738 #endif /* DX_DEBUG */ 739 740 /* 741 * Probe for a directory leaf block to search. 742 * 743 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format 744 * error in the directory index, and the caller should fall back to 745 * searching the directory normally. The callers of dx_probe **MUST** 746 * check for this error code, and make sure it never gets reflected 747 * back to userspace. 748 */ 749 static struct dx_frame * 750 dx_probe(struct ext4_filename *fname, struct inode *dir, 751 struct dx_hash_info *hinfo, struct dx_frame *frame_in) 752 { 753 unsigned count, indirect; 754 struct dx_entry *at, *entries, *p, *q, *m; 755 struct dx_root *root; 756 struct dx_frame *frame = frame_in; 757 struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR); 758 u32 hash; 759 760 memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0])); 761 frame->bh = ext4_read_dirblock(dir, 0, INDEX); 762 if (IS_ERR(frame->bh)) 763 return (struct dx_frame *) frame->bh; 764 765 root = (struct dx_root *) frame->bh->b_data; 766 if (root->info.hash_version != DX_HASH_TEA && 767 root->info.hash_version != DX_HASH_HALF_MD4 && 768 root->info.hash_version != DX_HASH_LEGACY) { 769 ext4_warning_inode(dir, "Unrecognised inode hash code %u", 770 root->info.hash_version); 771 goto fail; 772 } 773 if (fname) 774 hinfo = &fname->hinfo; 775 hinfo->hash_version = root->info.hash_version; 776 if (hinfo->hash_version <= DX_HASH_TEA) 777 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; 778 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed; 779 if (fname && fname_name(fname)) 780 ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), hinfo); 781 hash = hinfo->hash; 782 783 if (root->info.unused_flags & 1) { 784 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x", 785 root->info.unused_flags); 786 goto fail; 787 } 788 789 indirect = root->info.indirect_levels; 790 if (indirect >= ext4_dir_htree_level(dir->i_sb)) { 791 ext4_warning(dir->i_sb, 792 "Directory (ino: %lu) htree depth %#06x exceed" 793 "supported value", dir->i_ino, 794 ext4_dir_htree_level(dir->i_sb)); 795 if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) { 796 ext4_warning(dir->i_sb, "Enable large directory " 797 "feature to access it"); 798 } 799 goto fail; 800 } 801 802 entries = (struct dx_entry *)(((char *)&root->info) + 803 root->info.info_length); 804 805 if (dx_get_limit(entries) != dx_root_limit(dir, 806 root->info.info_length)) { 807 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u", 808 dx_get_limit(entries), 809 dx_root_limit(dir, root->info.info_length)); 810 goto fail; 811 } 812 813 dxtrace(printk("Look up %x", hash)); 814 while (1) { 815 count = dx_get_count(entries); 816 if (!count || count > dx_get_limit(entries)) { 817 ext4_warning_inode(dir, 818 "dx entry: count %u beyond limit %u", 819 count, dx_get_limit(entries)); 820 goto fail; 821 } 822 823 p = entries + 1; 824 q = entries + count - 1; 825 while (p <= q) { 826 m = p + (q - p) / 2; 827 dxtrace(printk(KERN_CONT ".")); 828 if (dx_get_hash(m) > hash) 829 q = m - 1; 830 else 831 p = m + 1; 832 } 833 834 if (0) { // linear search cross check 835 unsigned n = count - 1; 836 at = entries; 837 while (n--) 838 { 839 dxtrace(printk(KERN_CONT ",")); 840 if (dx_get_hash(++at) > hash) 841 { 842 at--; 843 break; 844 } 845 } 846 assert (at == p - 1); 847 } 848 849 at = p - 1; 850 dxtrace(printk(KERN_CONT " %x->%u\n", 851 at == entries ? 0 : dx_get_hash(at), 852 dx_get_block(at))); 853 frame->entries = entries; 854 frame->at = at; 855 if (!indirect--) 856 return frame; 857 frame++; 858 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX); 859 if (IS_ERR(frame->bh)) { 860 ret_err = (struct dx_frame *) frame->bh; 861 frame->bh = NULL; 862 goto fail; 863 } 864 entries = ((struct dx_node *) frame->bh->b_data)->entries; 865 866 if (dx_get_limit(entries) != dx_node_limit(dir)) { 867 ext4_warning_inode(dir, 868 "dx entry: limit %u != node limit %u", 869 dx_get_limit(entries), dx_node_limit(dir)); 870 goto fail; 871 } 872 } 873 fail: 874 while (frame >= frame_in) { 875 brelse(frame->bh); 876 frame--; 877 } 878 879 if (ret_err == ERR_PTR(ERR_BAD_DX_DIR)) 880 ext4_warning_inode(dir, 881 "Corrupt directory, running e2fsck is recommended"); 882 return ret_err; 883 } 884 885 static void dx_release(struct dx_frame *frames) 886 { 887 struct dx_root_info *info; 888 int i; 889 unsigned int indirect_levels; 890 891 if (frames[0].bh == NULL) 892 return; 893 894 info = &((struct dx_root *)frames[0].bh->b_data)->info; 895 /* save local copy, "info" may be freed after brelse() */ 896 indirect_levels = info->indirect_levels; 897 for (i = 0; i <= indirect_levels; i++) { 898 if (frames[i].bh == NULL) 899 break; 900 brelse(frames[i].bh); 901 frames[i].bh = NULL; 902 } 903 } 904 905 /* 906 * This function increments the frame pointer to search the next leaf 907 * block, and reads in the necessary intervening nodes if the search 908 * should be necessary. Whether or not the search is necessary is 909 * controlled by the hash parameter. If the hash value is even, then 910 * the search is only continued if the next block starts with that 911 * hash value. This is used if we are searching for a specific file. 912 * 913 * If the hash value is HASH_NB_ALWAYS, then always go to the next block. 914 * 915 * This function returns 1 if the caller should continue to search, 916 * or 0 if it should not. If there is an error reading one of the 917 * index blocks, it will a negative error code. 918 * 919 * If start_hash is non-null, it will be filled in with the starting 920 * hash of the next page. 921 */ 922 static int ext4_htree_next_block(struct inode *dir, __u32 hash, 923 struct dx_frame *frame, 924 struct dx_frame *frames, 925 __u32 *start_hash) 926 { 927 struct dx_frame *p; 928 struct buffer_head *bh; 929 int num_frames = 0; 930 __u32 bhash; 931 932 p = frame; 933 /* 934 * Find the next leaf page by incrementing the frame pointer. 935 * If we run out of entries in the interior node, loop around and 936 * increment pointer in the parent node. When we break out of 937 * this loop, num_frames indicates the number of interior 938 * nodes need to be read. 939 */ 940 while (1) { 941 if (++(p->at) < p->entries + dx_get_count(p->entries)) 942 break; 943 if (p == frames) 944 return 0; 945 num_frames++; 946 p--; 947 } 948 949 /* 950 * If the hash is 1, then continue only if the next page has a 951 * continuation hash of any value. This is used for readdir 952 * handling. Otherwise, check to see if the hash matches the 953 * desired contiuation hash. If it doesn't, return since 954 * there's no point to read in the successive index pages. 955 */ 956 bhash = dx_get_hash(p->at); 957 if (start_hash) 958 *start_hash = bhash; 959 if ((hash & 1) == 0) { 960 if ((bhash & ~1) != hash) 961 return 0; 962 } 963 /* 964 * If the hash is HASH_NB_ALWAYS, we always go to the next 965 * block so no check is necessary 966 */ 967 while (num_frames--) { 968 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX); 969 if (IS_ERR(bh)) 970 return PTR_ERR(bh); 971 p++; 972 brelse(p->bh); 973 p->bh = bh; 974 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries; 975 } 976 return 1; 977 } 978 979 980 /* 981 * This function fills a red-black tree with information from a 982 * directory block. It returns the number directory entries loaded 983 * into the tree. If there is an error it is returned in err. 984 */ 985 static int htree_dirblock_to_tree(struct file *dir_file, 986 struct inode *dir, ext4_lblk_t block, 987 struct dx_hash_info *hinfo, 988 __u32 start_hash, __u32 start_minor_hash) 989 { 990 struct buffer_head *bh; 991 struct ext4_dir_entry_2 *de, *top; 992 int err = 0, count = 0; 993 struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str; 994 995 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n", 996 (unsigned long)block)); 997 bh = ext4_read_dirblock(dir, block, DIRENT_HTREE); 998 if (IS_ERR(bh)) 999 return PTR_ERR(bh); 1000 1001 de = (struct ext4_dir_entry_2 *) bh->b_data; 1002 top = (struct ext4_dir_entry_2 *) ((char *) de + 1003 dir->i_sb->s_blocksize - 1004 EXT4_DIR_REC_LEN(0)); 1005 /* Check if the directory is encrypted */ 1006 if (IS_ENCRYPTED(dir)) { 1007 err = fscrypt_prepare_readdir(dir); 1008 if (err < 0) { 1009 brelse(bh); 1010 return err; 1011 } 1012 err = fscrypt_fname_alloc_buffer(EXT4_NAME_LEN, 1013 &fname_crypto_str); 1014 if (err < 0) { 1015 brelse(bh); 1016 return err; 1017 } 1018 } 1019 1020 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) { 1021 if (ext4_check_dir_entry(dir, NULL, de, bh, 1022 bh->b_data, bh->b_size, 1023 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb)) 1024 + ((char *)de - bh->b_data))) { 1025 /* silently ignore the rest of the block */ 1026 break; 1027 } 1028 ext4fs_dirhash(dir, de->name, de->name_len, hinfo); 1029 if ((hinfo->hash < start_hash) || 1030 ((hinfo->hash == start_hash) && 1031 (hinfo->minor_hash < start_minor_hash))) 1032 continue; 1033 if (de->inode == 0) 1034 continue; 1035 if (!IS_ENCRYPTED(dir)) { 1036 tmp_str.name = de->name; 1037 tmp_str.len = de->name_len; 1038 err = ext4_htree_store_dirent(dir_file, 1039 hinfo->hash, hinfo->minor_hash, de, 1040 &tmp_str); 1041 } else { 1042 int save_len = fname_crypto_str.len; 1043 struct fscrypt_str de_name = FSTR_INIT(de->name, 1044 de->name_len); 1045 1046 /* Directory is encrypted */ 1047 err = fscrypt_fname_disk_to_usr(dir, hinfo->hash, 1048 hinfo->minor_hash, &de_name, 1049 &fname_crypto_str); 1050 if (err) { 1051 count = err; 1052 goto errout; 1053 } 1054 err = ext4_htree_store_dirent(dir_file, 1055 hinfo->hash, hinfo->minor_hash, de, 1056 &fname_crypto_str); 1057 fname_crypto_str.len = save_len; 1058 } 1059 if (err != 0) { 1060 count = err; 1061 goto errout; 1062 } 1063 count++; 1064 } 1065 errout: 1066 brelse(bh); 1067 fscrypt_fname_free_buffer(&fname_crypto_str); 1068 return count; 1069 } 1070 1071 1072 /* 1073 * This function fills a red-black tree with information from a 1074 * directory. We start scanning the directory in hash order, starting 1075 * at start_hash and start_minor_hash. 1076 * 1077 * This function returns the number of entries inserted into the tree, 1078 * or a negative error code. 1079 */ 1080 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash, 1081 __u32 start_minor_hash, __u32 *next_hash) 1082 { 1083 struct dx_hash_info hinfo; 1084 struct ext4_dir_entry_2 *de; 1085 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 1086 struct inode *dir; 1087 ext4_lblk_t block; 1088 int count = 0; 1089 int ret, err; 1090 __u32 hashval; 1091 struct fscrypt_str tmp_str; 1092 1093 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n", 1094 start_hash, start_minor_hash)); 1095 dir = file_inode(dir_file); 1096 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) { 1097 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version; 1098 if (hinfo.hash_version <= DX_HASH_TEA) 1099 hinfo.hash_version += 1100 EXT4_SB(dir->i_sb)->s_hash_unsigned; 1101 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; 1102 if (ext4_has_inline_data(dir)) { 1103 int has_inline_data = 1; 1104 count = ext4_inlinedir_to_tree(dir_file, dir, 0, 1105 &hinfo, start_hash, 1106 start_minor_hash, 1107 &has_inline_data); 1108 if (has_inline_data) { 1109 *next_hash = ~0; 1110 return count; 1111 } 1112 } 1113 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo, 1114 start_hash, start_minor_hash); 1115 *next_hash = ~0; 1116 return count; 1117 } 1118 hinfo.hash = start_hash; 1119 hinfo.minor_hash = 0; 1120 frame = dx_probe(NULL, dir, &hinfo, frames); 1121 if (IS_ERR(frame)) 1122 return PTR_ERR(frame); 1123 1124 /* Add '.' and '..' from the htree header */ 1125 if (!start_hash && !start_minor_hash) { 1126 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; 1127 tmp_str.name = de->name; 1128 tmp_str.len = de->name_len; 1129 err = ext4_htree_store_dirent(dir_file, 0, 0, 1130 de, &tmp_str); 1131 if (err != 0) 1132 goto errout; 1133 count++; 1134 } 1135 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) { 1136 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; 1137 de = ext4_next_entry(de, dir->i_sb->s_blocksize); 1138 tmp_str.name = de->name; 1139 tmp_str.len = de->name_len; 1140 err = ext4_htree_store_dirent(dir_file, 2, 0, 1141 de, &tmp_str); 1142 if (err != 0) 1143 goto errout; 1144 count++; 1145 } 1146 1147 while (1) { 1148 if (fatal_signal_pending(current)) { 1149 err = -ERESTARTSYS; 1150 goto errout; 1151 } 1152 cond_resched(); 1153 block = dx_get_block(frame->at); 1154 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo, 1155 start_hash, start_minor_hash); 1156 if (ret < 0) { 1157 err = ret; 1158 goto errout; 1159 } 1160 count += ret; 1161 hashval = ~0; 1162 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS, 1163 frame, frames, &hashval); 1164 *next_hash = hashval; 1165 if (ret < 0) { 1166 err = ret; 1167 goto errout; 1168 } 1169 /* 1170 * Stop if: (a) there are no more entries, or 1171 * (b) we have inserted at least one entry and the 1172 * next hash value is not a continuation 1173 */ 1174 if ((ret == 0) || 1175 (count && ((hashval & 1) == 0))) 1176 break; 1177 } 1178 dx_release(frames); 1179 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, " 1180 "next hash: %x\n", count, *next_hash)); 1181 return count; 1182 errout: 1183 dx_release(frames); 1184 return (err); 1185 } 1186 1187 static inline int search_dirblock(struct buffer_head *bh, 1188 struct inode *dir, 1189 struct ext4_filename *fname, 1190 unsigned int offset, 1191 struct ext4_dir_entry_2 **res_dir) 1192 { 1193 return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir, 1194 fname, offset, res_dir); 1195 } 1196 1197 /* 1198 * Directory block splitting, compacting 1199 */ 1200 1201 /* 1202 * Create map of hash values, offsets, and sizes, stored at end of block. 1203 * Returns number of entries mapped. 1204 */ 1205 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de, 1206 unsigned blocksize, struct dx_hash_info *hinfo, 1207 struct dx_map_entry *map_tail) 1208 { 1209 int count = 0; 1210 char *base = (char *) de; 1211 struct dx_hash_info h = *hinfo; 1212 1213 while ((char *) de < base + blocksize) { 1214 if (de->name_len && de->inode) { 1215 ext4fs_dirhash(dir, de->name, de->name_len, &h); 1216 map_tail--; 1217 map_tail->hash = h.hash; 1218 map_tail->offs = ((char *) de - base)>>2; 1219 map_tail->size = le16_to_cpu(de->rec_len); 1220 count++; 1221 cond_resched(); 1222 } 1223 /* XXX: do we need to check rec_len == 0 case? -Chris */ 1224 de = ext4_next_entry(de, blocksize); 1225 } 1226 return count; 1227 } 1228 1229 /* Sort map by hash value */ 1230 static void dx_sort_map (struct dx_map_entry *map, unsigned count) 1231 { 1232 struct dx_map_entry *p, *q, *top = map + count - 1; 1233 int more; 1234 /* Combsort until bubble sort doesn't suck */ 1235 while (count > 2) { 1236 count = count*10/13; 1237 if (count - 9 < 2) /* 9, 10 -> 11 */ 1238 count = 11; 1239 for (p = top, q = p - count; q >= map; p--, q--) 1240 if (p->hash < q->hash) 1241 swap(*p, *q); 1242 } 1243 /* Garden variety bubble sort */ 1244 do { 1245 more = 0; 1246 q = top; 1247 while (q-- > map) { 1248 if (q[1].hash >= q[0].hash) 1249 continue; 1250 swap(*(q+1), *q); 1251 more = 1; 1252 } 1253 } while(more); 1254 } 1255 1256 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block) 1257 { 1258 struct dx_entry *entries = frame->entries; 1259 struct dx_entry *old = frame->at, *new = old + 1; 1260 int count = dx_get_count(entries); 1261 1262 assert(count < dx_get_limit(entries)); 1263 assert(old < entries + count); 1264 memmove(new + 1, new, (char *)(entries + count) - (char *)(new)); 1265 dx_set_hash(new, hash); 1266 dx_set_block(new, block); 1267 dx_set_count(entries, count + 1); 1268 } 1269 1270 #ifdef CONFIG_UNICODE 1271 /* 1272 * Test whether a case-insensitive directory entry matches the filename 1273 * being searched for. If quick is set, assume the name being looked up 1274 * is already in the casefolded form. 1275 * 1276 * Returns: 0 if the directory entry matches, more than 0 if it 1277 * doesn't match or less than zero on error. 1278 */ 1279 int ext4_ci_compare(const struct inode *parent, const struct qstr *name, 1280 const struct qstr *entry, bool quick) 1281 { 1282 const struct super_block *sb = parent->i_sb; 1283 const struct unicode_map *um = sb->s_encoding; 1284 int ret; 1285 1286 if (quick) 1287 ret = utf8_strncasecmp_folded(um, name, entry); 1288 else 1289 ret = utf8_strncasecmp(um, name, entry); 1290 1291 if (ret < 0) { 1292 /* Handle invalid character sequence as either an error 1293 * or as an opaque byte sequence. 1294 */ 1295 if (sb_has_strict_encoding(sb)) 1296 return -EINVAL; 1297 1298 if (name->len != entry->len) 1299 return 1; 1300 1301 return !!memcmp(name->name, entry->name, name->len); 1302 } 1303 1304 return ret; 1305 } 1306 1307 void ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname, 1308 struct fscrypt_str *cf_name) 1309 { 1310 int len; 1311 1312 if (!IS_CASEFOLDED(dir) || !dir->i_sb->s_encoding) { 1313 cf_name->name = NULL; 1314 return; 1315 } 1316 1317 cf_name->name = kmalloc(EXT4_NAME_LEN, GFP_NOFS); 1318 if (!cf_name->name) 1319 return; 1320 1321 len = utf8_casefold(dir->i_sb->s_encoding, 1322 iname, cf_name->name, 1323 EXT4_NAME_LEN); 1324 if (len <= 0) { 1325 kfree(cf_name->name); 1326 cf_name->name = NULL; 1327 return; 1328 } 1329 cf_name->len = (unsigned) len; 1330 1331 } 1332 #endif 1333 1334 /* 1335 * Test whether a directory entry matches the filename being searched for. 1336 * 1337 * Return: %true if the directory entry matches, otherwise %false. 1338 */ 1339 static inline bool ext4_match(const struct inode *parent, 1340 const struct ext4_filename *fname, 1341 const struct ext4_dir_entry_2 *de) 1342 { 1343 struct fscrypt_name f; 1344 #ifdef CONFIG_UNICODE 1345 const struct qstr entry = {.name = de->name, .len = de->name_len}; 1346 #endif 1347 1348 if (!de->inode) 1349 return false; 1350 1351 f.usr_fname = fname->usr_fname; 1352 f.disk_name = fname->disk_name; 1353 #ifdef CONFIG_FS_ENCRYPTION 1354 f.crypto_buf = fname->crypto_buf; 1355 #endif 1356 1357 #ifdef CONFIG_UNICODE 1358 if (parent->i_sb->s_encoding && IS_CASEFOLDED(parent)) { 1359 if (fname->cf_name.name) { 1360 struct qstr cf = {.name = fname->cf_name.name, 1361 .len = fname->cf_name.len}; 1362 return !ext4_ci_compare(parent, &cf, &entry, true); 1363 } 1364 return !ext4_ci_compare(parent, fname->usr_fname, &entry, 1365 false); 1366 } 1367 #endif 1368 1369 return fscrypt_match_name(&f, de->name, de->name_len); 1370 } 1371 1372 /* 1373 * Returns 0 if not found, -1 on failure, and 1 on success 1374 */ 1375 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size, 1376 struct inode *dir, struct ext4_filename *fname, 1377 unsigned int offset, struct ext4_dir_entry_2 **res_dir) 1378 { 1379 struct ext4_dir_entry_2 * de; 1380 char * dlimit; 1381 int de_len; 1382 1383 de = (struct ext4_dir_entry_2 *)search_buf; 1384 dlimit = search_buf + buf_size; 1385 while ((char *) de < dlimit) { 1386 /* this code is executed quadratically often */ 1387 /* do minimal checking `by hand' */ 1388 if ((char *) de + de->name_len <= dlimit && 1389 ext4_match(dir, fname, de)) { 1390 /* found a match - just to be sure, do 1391 * a full check */ 1392 if (ext4_check_dir_entry(dir, NULL, de, bh, search_buf, 1393 buf_size, offset)) 1394 return -1; 1395 *res_dir = de; 1396 return 1; 1397 } 1398 /* prevent looping on a bad block */ 1399 de_len = ext4_rec_len_from_disk(de->rec_len, 1400 dir->i_sb->s_blocksize); 1401 if (de_len <= 0) 1402 return -1; 1403 offset += de_len; 1404 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len); 1405 } 1406 return 0; 1407 } 1408 1409 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block, 1410 struct ext4_dir_entry *de) 1411 { 1412 struct super_block *sb = dir->i_sb; 1413 1414 if (!is_dx(dir)) 1415 return 0; 1416 if (block == 0) 1417 return 1; 1418 if (de->inode == 0 && 1419 ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) == 1420 sb->s_blocksize) 1421 return 1; 1422 return 0; 1423 } 1424 1425 /* 1426 * __ext4_find_entry() 1427 * 1428 * finds an entry in the specified directory with the wanted name. It 1429 * returns the cache buffer in which the entry was found, and the entry 1430 * itself (as a parameter - res_dir). It does NOT read the inode of the 1431 * entry - you'll have to do that yourself if you want to. 1432 * 1433 * The returned buffer_head has ->b_count elevated. The caller is expected 1434 * to brelse() it when appropriate. 1435 */ 1436 static struct buffer_head *__ext4_find_entry(struct inode *dir, 1437 struct ext4_filename *fname, 1438 struct ext4_dir_entry_2 **res_dir, 1439 int *inlined) 1440 { 1441 struct super_block *sb; 1442 struct buffer_head *bh_use[NAMEI_RA_SIZE]; 1443 struct buffer_head *bh, *ret = NULL; 1444 ext4_lblk_t start, block; 1445 const u8 *name = fname->usr_fname->name; 1446 size_t ra_max = 0; /* Number of bh's in the readahead 1447 buffer, bh_use[] */ 1448 size_t ra_ptr = 0; /* Current index into readahead 1449 buffer */ 1450 ext4_lblk_t nblocks; 1451 int i, namelen, retval; 1452 1453 *res_dir = NULL; 1454 sb = dir->i_sb; 1455 namelen = fname->usr_fname->len; 1456 if (namelen > EXT4_NAME_LEN) 1457 return NULL; 1458 1459 if (ext4_has_inline_data(dir)) { 1460 int has_inline_data = 1; 1461 ret = ext4_find_inline_entry(dir, fname, res_dir, 1462 &has_inline_data); 1463 if (has_inline_data) { 1464 if (inlined) 1465 *inlined = 1; 1466 goto cleanup_and_exit; 1467 } 1468 } 1469 1470 if ((namelen <= 2) && (name[0] == '.') && 1471 (name[1] == '.' || name[1] == '\0')) { 1472 /* 1473 * "." or ".." will only be in the first block 1474 * NFS may look up ".."; "." should be handled by the VFS 1475 */ 1476 block = start = 0; 1477 nblocks = 1; 1478 goto restart; 1479 } 1480 if (is_dx(dir)) { 1481 ret = ext4_dx_find_entry(dir, fname, res_dir); 1482 /* 1483 * On success, or if the error was file not found, 1484 * return. Otherwise, fall back to doing a search the 1485 * old fashioned way. 1486 */ 1487 if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR) 1488 goto cleanup_and_exit; 1489 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, " 1490 "falling back\n")); 1491 ret = NULL; 1492 } 1493 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); 1494 if (!nblocks) { 1495 ret = NULL; 1496 goto cleanup_and_exit; 1497 } 1498 start = EXT4_I(dir)->i_dir_start_lookup; 1499 if (start >= nblocks) 1500 start = 0; 1501 block = start; 1502 restart: 1503 do { 1504 /* 1505 * We deal with the read-ahead logic here. 1506 */ 1507 cond_resched(); 1508 if (ra_ptr >= ra_max) { 1509 /* Refill the readahead buffer */ 1510 ra_ptr = 0; 1511 if (block < start) 1512 ra_max = start - block; 1513 else 1514 ra_max = nblocks - block; 1515 ra_max = min(ra_max, ARRAY_SIZE(bh_use)); 1516 retval = ext4_bread_batch(dir, block, ra_max, 1517 false /* wait */, bh_use); 1518 if (retval) { 1519 ret = ERR_PTR(retval); 1520 ra_max = 0; 1521 goto cleanup_and_exit; 1522 } 1523 } 1524 if ((bh = bh_use[ra_ptr++]) == NULL) 1525 goto next; 1526 wait_on_buffer(bh); 1527 if (!buffer_uptodate(bh)) { 1528 EXT4_ERROR_INODE_ERR(dir, EIO, 1529 "reading directory lblock %lu", 1530 (unsigned long) block); 1531 brelse(bh); 1532 ret = ERR_PTR(-EIO); 1533 goto cleanup_and_exit; 1534 } 1535 if (!buffer_verified(bh) && 1536 !is_dx_internal_node(dir, block, 1537 (struct ext4_dir_entry *)bh->b_data) && 1538 !ext4_dirblock_csum_verify(dir, bh)) { 1539 EXT4_ERROR_INODE_ERR(dir, EFSBADCRC, 1540 "checksumming directory " 1541 "block %lu", (unsigned long)block); 1542 brelse(bh); 1543 ret = ERR_PTR(-EFSBADCRC); 1544 goto cleanup_and_exit; 1545 } 1546 set_buffer_verified(bh); 1547 i = search_dirblock(bh, dir, fname, 1548 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir); 1549 if (i == 1) { 1550 EXT4_I(dir)->i_dir_start_lookup = block; 1551 ret = bh; 1552 goto cleanup_and_exit; 1553 } else { 1554 brelse(bh); 1555 if (i < 0) 1556 goto cleanup_and_exit; 1557 } 1558 next: 1559 if (++block >= nblocks) 1560 block = 0; 1561 } while (block != start); 1562 1563 /* 1564 * If the directory has grown while we were searching, then 1565 * search the last part of the directory before giving up. 1566 */ 1567 block = nblocks; 1568 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); 1569 if (block < nblocks) { 1570 start = 0; 1571 goto restart; 1572 } 1573 1574 cleanup_and_exit: 1575 /* Clean up the read-ahead blocks */ 1576 for (; ra_ptr < ra_max; ra_ptr++) 1577 brelse(bh_use[ra_ptr]); 1578 return ret; 1579 } 1580 1581 static struct buffer_head *ext4_find_entry(struct inode *dir, 1582 const struct qstr *d_name, 1583 struct ext4_dir_entry_2 **res_dir, 1584 int *inlined) 1585 { 1586 int err; 1587 struct ext4_filename fname; 1588 struct buffer_head *bh; 1589 1590 err = ext4_fname_setup_filename(dir, d_name, 1, &fname); 1591 if (err == -ENOENT) 1592 return NULL; 1593 if (err) 1594 return ERR_PTR(err); 1595 1596 bh = __ext4_find_entry(dir, &fname, res_dir, inlined); 1597 1598 ext4_fname_free_filename(&fname); 1599 return bh; 1600 } 1601 1602 static struct buffer_head *ext4_lookup_entry(struct inode *dir, 1603 struct dentry *dentry, 1604 struct ext4_dir_entry_2 **res_dir) 1605 { 1606 int err; 1607 struct ext4_filename fname; 1608 struct buffer_head *bh; 1609 1610 err = ext4_fname_prepare_lookup(dir, dentry, &fname); 1611 if (err == -ENOENT) 1612 return NULL; 1613 if (err) 1614 return ERR_PTR(err); 1615 1616 bh = __ext4_find_entry(dir, &fname, res_dir, NULL); 1617 1618 ext4_fname_free_filename(&fname); 1619 return bh; 1620 } 1621 1622 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, 1623 struct ext4_filename *fname, 1624 struct ext4_dir_entry_2 **res_dir) 1625 { 1626 struct super_block * sb = dir->i_sb; 1627 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 1628 struct buffer_head *bh; 1629 ext4_lblk_t block; 1630 int retval; 1631 1632 #ifdef CONFIG_FS_ENCRYPTION 1633 *res_dir = NULL; 1634 #endif 1635 frame = dx_probe(fname, dir, NULL, frames); 1636 if (IS_ERR(frame)) 1637 return (struct buffer_head *) frame; 1638 do { 1639 block = dx_get_block(frame->at); 1640 bh = ext4_read_dirblock(dir, block, DIRENT_HTREE); 1641 if (IS_ERR(bh)) 1642 goto errout; 1643 1644 retval = search_dirblock(bh, dir, fname, 1645 block << EXT4_BLOCK_SIZE_BITS(sb), 1646 res_dir); 1647 if (retval == 1) 1648 goto success; 1649 brelse(bh); 1650 if (retval == -1) { 1651 bh = ERR_PTR(ERR_BAD_DX_DIR); 1652 goto errout; 1653 } 1654 1655 /* Check to see if we should continue to search */ 1656 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame, 1657 frames, NULL); 1658 if (retval < 0) { 1659 ext4_warning_inode(dir, 1660 "error %d reading directory index block", 1661 retval); 1662 bh = ERR_PTR(retval); 1663 goto errout; 1664 } 1665 } while (retval == 1); 1666 1667 bh = NULL; 1668 errout: 1669 dxtrace(printk(KERN_DEBUG "%s not found\n", fname->usr_fname->name)); 1670 success: 1671 dx_release(frames); 1672 return bh; 1673 } 1674 1675 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 1676 { 1677 struct inode *inode; 1678 struct ext4_dir_entry_2 *de; 1679 struct buffer_head *bh; 1680 1681 if (dentry->d_name.len > EXT4_NAME_LEN) 1682 return ERR_PTR(-ENAMETOOLONG); 1683 1684 bh = ext4_lookup_entry(dir, dentry, &de); 1685 if (IS_ERR(bh)) 1686 return ERR_CAST(bh); 1687 inode = NULL; 1688 if (bh) { 1689 __u32 ino = le32_to_cpu(de->inode); 1690 brelse(bh); 1691 if (!ext4_valid_inum(dir->i_sb, ino)) { 1692 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino); 1693 return ERR_PTR(-EFSCORRUPTED); 1694 } 1695 if (unlikely(ino == dir->i_ino)) { 1696 EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir", 1697 dentry); 1698 return ERR_PTR(-EFSCORRUPTED); 1699 } 1700 inode = ext4_iget(dir->i_sb, ino, EXT4_IGET_NORMAL); 1701 if (inode == ERR_PTR(-ESTALE)) { 1702 EXT4_ERROR_INODE(dir, 1703 "deleted inode referenced: %u", 1704 ino); 1705 return ERR_PTR(-EFSCORRUPTED); 1706 } 1707 if (!IS_ERR(inode) && IS_ENCRYPTED(dir) && 1708 (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) && 1709 !fscrypt_has_permitted_context(dir, inode)) { 1710 ext4_warning(inode->i_sb, 1711 "Inconsistent encryption contexts: %lu/%lu", 1712 dir->i_ino, inode->i_ino); 1713 iput(inode); 1714 return ERR_PTR(-EPERM); 1715 } 1716 } 1717 1718 #ifdef CONFIG_UNICODE 1719 if (!inode && IS_CASEFOLDED(dir)) { 1720 /* Eventually we want to call d_add_ci(dentry, NULL) 1721 * for negative dentries in the encoding case as 1722 * well. For now, prevent the negative dentry 1723 * from being cached. 1724 */ 1725 return NULL; 1726 } 1727 #endif 1728 return d_splice_alias(inode, dentry); 1729 } 1730 1731 1732 struct dentry *ext4_get_parent(struct dentry *child) 1733 { 1734 __u32 ino; 1735 static const struct qstr dotdot = QSTR_INIT("..", 2); 1736 struct ext4_dir_entry_2 * de; 1737 struct buffer_head *bh; 1738 1739 bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL); 1740 if (IS_ERR(bh)) 1741 return ERR_CAST(bh); 1742 if (!bh) 1743 return ERR_PTR(-ENOENT); 1744 ino = le32_to_cpu(de->inode); 1745 brelse(bh); 1746 1747 if (!ext4_valid_inum(child->d_sb, ino)) { 1748 EXT4_ERROR_INODE(d_inode(child), 1749 "bad parent inode number: %u", ino); 1750 return ERR_PTR(-EFSCORRUPTED); 1751 } 1752 1753 return d_obtain_alias(ext4_iget(child->d_sb, ino, EXT4_IGET_NORMAL)); 1754 } 1755 1756 /* 1757 * Move count entries from end of map between two memory locations. 1758 * Returns pointer to last entry moved. 1759 */ 1760 static struct ext4_dir_entry_2 * 1761 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count, 1762 unsigned blocksize) 1763 { 1764 unsigned rec_len = 0; 1765 1766 while (count--) { 1767 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) 1768 (from + (map->offs<<2)); 1769 rec_len = EXT4_DIR_REC_LEN(de->name_len); 1770 memcpy (to, de, rec_len); 1771 ((struct ext4_dir_entry_2 *) to)->rec_len = 1772 ext4_rec_len_to_disk(rec_len, blocksize); 1773 de->inode = 0; 1774 map++; 1775 to += rec_len; 1776 } 1777 return (struct ext4_dir_entry_2 *) (to - rec_len); 1778 } 1779 1780 /* 1781 * Compact each dir entry in the range to the minimal rec_len. 1782 * Returns pointer to last entry in range. 1783 */ 1784 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize) 1785 { 1786 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base; 1787 unsigned rec_len = 0; 1788 1789 prev = to = de; 1790 while ((char*)de < base + blocksize) { 1791 next = ext4_next_entry(de, blocksize); 1792 if (de->inode && de->name_len) { 1793 rec_len = EXT4_DIR_REC_LEN(de->name_len); 1794 if (de > to) 1795 memmove(to, de, rec_len); 1796 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize); 1797 prev = to; 1798 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len); 1799 } 1800 de = next; 1801 } 1802 return prev; 1803 } 1804 1805 /* 1806 * Split a full leaf block to make room for a new dir entry. 1807 * Allocate a new block, and move entries so that they are approx. equally full. 1808 * Returns pointer to de in block into which the new entry will be inserted. 1809 */ 1810 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir, 1811 struct buffer_head **bh,struct dx_frame *frame, 1812 struct dx_hash_info *hinfo) 1813 { 1814 unsigned blocksize = dir->i_sb->s_blocksize; 1815 unsigned count, continued; 1816 struct buffer_head *bh2; 1817 ext4_lblk_t newblock; 1818 u32 hash2; 1819 struct dx_map_entry *map; 1820 char *data1 = (*bh)->b_data, *data2; 1821 unsigned split, move, size; 1822 struct ext4_dir_entry_2 *de = NULL, *de2; 1823 int csum_size = 0; 1824 int err = 0, i; 1825 1826 if (ext4_has_metadata_csum(dir->i_sb)) 1827 csum_size = sizeof(struct ext4_dir_entry_tail); 1828 1829 bh2 = ext4_append(handle, dir, &newblock); 1830 if (IS_ERR(bh2)) { 1831 brelse(*bh); 1832 *bh = NULL; 1833 return (struct ext4_dir_entry_2 *) bh2; 1834 } 1835 1836 BUFFER_TRACE(*bh, "get_write_access"); 1837 err = ext4_journal_get_write_access(handle, *bh); 1838 if (err) 1839 goto journal_error; 1840 1841 BUFFER_TRACE(frame->bh, "get_write_access"); 1842 err = ext4_journal_get_write_access(handle, frame->bh); 1843 if (err) 1844 goto journal_error; 1845 1846 data2 = bh2->b_data; 1847 1848 /* create map in the end of data2 block */ 1849 map = (struct dx_map_entry *) (data2 + blocksize); 1850 count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1, 1851 blocksize, hinfo, map); 1852 map -= count; 1853 dx_sort_map(map, count); 1854 /* Ensure that neither split block is over half full */ 1855 size = 0; 1856 move = 0; 1857 for (i = count-1; i >= 0; i--) { 1858 /* is more than half of this entry in 2nd half of the block? */ 1859 if (size + map[i].size/2 > blocksize/2) 1860 break; 1861 size += map[i].size; 1862 move++; 1863 } 1864 /* 1865 * map index at which we will split 1866 * 1867 * If the sum of active entries didn't exceed half the block size, just 1868 * split it in half by count; each resulting block will have at least 1869 * half the space free. 1870 */ 1871 if (i > 0) 1872 split = count - move; 1873 else 1874 split = count/2; 1875 1876 hash2 = map[split].hash; 1877 continued = hash2 == map[split - 1].hash; 1878 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n", 1879 (unsigned long)dx_get_block(frame->at), 1880 hash2, split, count-split)); 1881 1882 /* Fancy dance to stay within two buffers */ 1883 de2 = dx_move_dirents(data1, data2, map + split, count - split, 1884 blocksize); 1885 de = dx_pack_dirents(data1, blocksize); 1886 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) - 1887 (char *) de, 1888 blocksize); 1889 de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) - 1890 (char *) de2, 1891 blocksize); 1892 if (csum_size) { 1893 ext4_initialize_dirent_tail(*bh, blocksize); 1894 ext4_initialize_dirent_tail(bh2, blocksize); 1895 } 1896 1897 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1, 1898 blocksize, 1)); 1899 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2, 1900 blocksize, 1)); 1901 1902 /* Which block gets the new entry? */ 1903 if (hinfo->hash >= hash2) { 1904 swap(*bh, bh2); 1905 de = de2; 1906 } 1907 dx_insert_block(frame, hash2 + continued, newblock); 1908 err = ext4_handle_dirty_dirblock(handle, dir, bh2); 1909 if (err) 1910 goto journal_error; 1911 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 1912 if (err) 1913 goto journal_error; 1914 brelse(bh2); 1915 dxtrace(dx_show_index("frame", frame->entries)); 1916 return de; 1917 1918 journal_error: 1919 brelse(*bh); 1920 brelse(bh2); 1921 *bh = NULL; 1922 ext4_std_error(dir->i_sb, err); 1923 return ERR_PTR(err); 1924 } 1925 1926 int ext4_find_dest_de(struct inode *dir, struct inode *inode, 1927 struct buffer_head *bh, 1928 void *buf, int buf_size, 1929 struct ext4_filename *fname, 1930 struct ext4_dir_entry_2 **dest_de) 1931 { 1932 struct ext4_dir_entry_2 *de; 1933 unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname)); 1934 int nlen, rlen; 1935 unsigned int offset = 0; 1936 char *top; 1937 1938 de = (struct ext4_dir_entry_2 *)buf; 1939 top = buf + buf_size - reclen; 1940 while ((char *) de <= top) { 1941 if (ext4_check_dir_entry(dir, NULL, de, bh, 1942 buf, buf_size, offset)) 1943 return -EFSCORRUPTED; 1944 if (ext4_match(dir, fname, de)) 1945 return -EEXIST; 1946 nlen = EXT4_DIR_REC_LEN(de->name_len); 1947 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 1948 if ((de->inode ? rlen - nlen : rlen) >= reclen) 1949 break; 1950 de = (struct ext4_dir_entry_2 *)((char *)de + rlen); 1951 offset += rlen; 1952 } 1953 if ((char *) de > top) 1954 return -ENOSPC; 1955 1956 *dest_de = de; 1957 return 0; 1958 } 1959 1960 void ext4_insert_dentry(struct inode *inode, 1961 struct ext4_dir_entry_2 *de, 1962 int buf_size, 1963 struct ext4_filename *fname) 1964 { 1965 1966 int nlen, rlen; 1967 1968 nlen = EXT4_DIR_REC_LEN(de->name_len); 1969 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 1970 if (de->inode) { 1971 struct ext4_dir_entry_2 *de1 = 1972 (struct ext4_dir_entry_2 *)((char *)de + nlen); 1973 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size); 1974 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size); 1975 de = de1; 1976 } 1977 de->file_type = EXT4_FT_UNKNOWN; 1978 de->inode = cpu_to_le32(inode->i_ino); 1979 ext4_set_de_type(inode->i_sb, de, inode->i_mode); 1980 de->name_len = fname_len(fname); 1981 memcpy(de->name, fname_name(fname), fname_len(fname)); 1982 } 1983 1984 /* 1985 * Add a new entry into a directory (leaf) block. If de is non-NULL, 1986 * it points to a directory entry which is guaranteed to be large 1987 * enough for new directory entry. If de is NULL, then 1988 * add_dirent_to_buf will attempt search the directory block for 1989 * space. It will return -ENOSPC if no space is available, and -EIO 1990 * and -EEXIST if directory entry already exists. 1991 */ 1992 static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname, 1993 struct inode *dir, 1994 struct inode *inode, struct ext4_dir_entry_2 *de, 1995 struct buffer_head *bh) 1996 { 1997 unsigned int blocksize = dir->i_sb->s_blocksize; 1998 int csum_size = 0; 1999 int err, err2; 2000 2001 if (ext4_has_metadata_csum(inode->i_sb)) 2002 csum_size = sizeof(struct ext4_dir_entry_tail); 2003 2004 if (!de) { 2005 err = ext4_find_dest_de(dir, inode, bh, bh->b_data, 2006 blocksize - csum_size, fname, &de); 2007 if (err) 2008 return err; 2009 } 2010 BUFFER_TRACE(bh, "get_write_access"); 2011 err = ext4_journal_get_write_access(handle, bh); 2012 if (err) { 2013 ext4_std_error(dir->i_sb, err); 2014 return err; 2015 } 2016 2017 /* By now the buffer is marked for journaling */ 2018 ext4_insert_dentry(inode, de, blocksize, fname); 2019 2020 /* 2021 * XXX shouldn't update any times until successful 2022 * completion of syscall, but too many callers depend 2023 * on this. 2024 * 2025 * XXX similarly, too many callers depend on 2026 * ext4_new_inode() setting the times, but error 2027 * recovery deletes the inode, so the worst that can 2028 * happen is that the times are slightly out of date 2029 * and/or different from the directory change time. 2030 */ 2031 dir->i_mtime = dir->i_ctime = current_time(dir); 2032 ext4_update_dx_flag(dir); 2033 inode_inc_iversion(dir); 2034 err2 = ext4_mark_inode_dirty(handle, dir); 2035 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); 2036 err = ext4_handle_dirty_dirblock(handle, dir, bh); 2037 if (err) 2038 ext4_std_error(dir->i_sb, err); 2039 return err ? err : err2; 2040 } 2041 2042 /* 2043 * This converts a one block unindexed directory to a 3 block indexed 2044 * directory, and adds the dentry to the indexed directory. 2045 */ 2046 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname, 2047 struct inode *dir, 2048 struct inode *inode, struct buffer_head *bh) 2049 { 2050 struct buffer_head *bh2; 2051 struct dx_root *root; 2052 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 2053 struct dx_entry *entries; 2054 struct ext4_dir_entry_2 *de, *de2; 2055 char *data2, *top; 2056 unsigned len; 2057 int retval; 2058 unsigned blocksize; 2059 ext4_lblk_t block; 2060 struct fake_dirent *fde; 2061 int csum_size = 0; 2062 2063 if (ext4_has_metadata_csum(inode->i_sb)) 2064 csum_size = sizeof(struct ext4_dir_entry_tail); 2065 2066 blocksize = dir->i_sb->s_blocksize; 2067 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino)); 2068 BUFFER_TRACE(bh, "get_write_access"); 2069 retval = ext4_journal_get_write_access(handle, bh); 2070 if (retval) { 2071 ext4_std_error(dir->i_sb, retval); 2072 brelse(bh); 2073 return retval; 2074 } 2075 root = (struct dx_root *) bh->b_data; 2076 2077 /* The 0th block becomes the root, move the dirents out */ 2078 fde = &root->dotdot; 2079 de = (struct ext4_dir_entry_2 *)((char *)fde + 2080 ext4_rec_len_from_disk(fde->rec_len, blocksize)); 2081 if ((char *) de >= (((char *) root) + blocksize)) { 2082 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'"); 2083 brelse(bh); 2084 return -EFSCORRUPTED; 2085 } 2086 len = ((char *) root) + (blocksize - csum_size) - (char *) de; 2087 2088 /* Allocate new block for the 0th block's dirents */ 2089 bh2 = ext4_append(handle, dir, &block); 2090 if (IS_ERR(bh2)) { 2091 brelse(bh); 2092 return PTR_ERR(bh2); 2093 } 2094 ext4_set_inode_flag(dir, EXT4_INODE_INDEX); 2095 data2 = bh2->b_data; 2096 2097 memcpy(data2, de, len); 2098 de = (struct ext4_dir_entry_2 *) data2; 2099 top = data2 + len; 2100 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top) 2101 de = de2; 2102 de->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) - 2103 (char *) de, blocksize); 2104 2105 if (csum_size) 2106 ext4_initialize_dirent_tail(bh2, blocksize); 2107 2108 /* Initialize the root; the dot dirents already exist */ 2109 de = (struct ext4_dir_entry_2 *) (&root->dotdot); 2110 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2), 2111 blocksize); 2112 memset (&root->info, 0, sizeof(root->info)); 2113 root->info.info_length = sizeof(root->info); 2114 root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version; 2115 entries = root->entries; 2116 dx_set_block(entries, 1); 2117 dx_set_count(entries, 1); 2118 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info))); 2119 2120 /* Initialize as for dx_probe */ 2121 fname->hinfo.hash_version = root->info.hash_version; 2122 if (fname->hinfo.hash_version <= DX_HASH_TEA) 2123 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; 2124 fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; 2125 ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), &fname->hinfo); 2126 2127 memset(frames, 0, sizeof(frames)); 2128 frame = frames; 2129 frame->entries = entries; 2130 frame->at = entries; 2131 frame->bh = bh; 2132 2133 retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 2134 if (retval) 2135 goto out_frames; 2136 retval = ext4_handle_dirty_dirblock(handle, dir, bh2); 2137 if (retval) 2138 goto out_frames; 2139 2140 de = do_split(handle,dir, &bh2, frame, &fname->hinfo); 2141 if (IS_ERR(de)) { 2142 retval = PTR_ERR(de); 2143 goto out_frames; 2144 } 2145 2146 retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2); 2147 out_frames: 2148 /* 2149 * Even if the block split failed, we have to properly write 2150 * out all the changes we did so far. Otherwise we can end up 2151 * with corrupted filesystem. 2152 */ 2153 if (retval) 2154 ext4_mark_inode_dirty(handle, dir); 2155 dx_release(frames); 2156 brelse(bh2); 2157 return retval; 2158 } 2159 2160 /* 2161 * ext4_add_entry() 2162 * 2163 * adds a file entry to the specified directory, using the same 2164 * semantics as ext4_find_entry(). It returns NULL if it failed. 2165 * 2166 * NOTE!! The inode part of 'de' is left at 0 - which means you 2167 * may not sleep between calling this and putting something into 2168 * the entry, as someone else might have used it while you slept. 2169 */ 2170 static int ext4_add_entry(handle_t *handle, struct dentry *dentry, 2171 struct inode *inode) 2172 { 2173 struct inode *dir = d_inode(dentry->d_parent); 2174 struct buffer_head *bh = NULL; 2175 struct ext4_dir_entry_2 *de; 2176 struct super_block *sb; 2177 struct ext4_filename fname; 2178 int retval; 2179 int dx_fallback=0; 2180 unsigned blocksize; 2181 ext4_lblk_t block, blocks; 2182 int csum_size = 0; 2183 2184 if (ext4_has_metadata_csum(inode->i_sb)) 2185 csum_size = sizeof(struct ext4_dir_entry_tail); 2186 2187 sb = dir->i_sb; 2188 blocksize = sb->s_blocksize; 2189 if (!dentry->d_name.len) 2190 return -EINVAL; 2191 2192 if (fscrypt_is_nokey_name(dentry)) 2193 return -ENOKEY; 2194 2195 #ifdef CONFIG_UNICODE 2196 if (sb_has_strict_encoding(sb) && IS_CASEFOLDED(dir) && 2197 sb->s_encoding && utf8_validate(sb->s_encoding, &dentry->d_name)) 2198 return -EINVAL; 2199 #endif 2200 2201 retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname); 2202 if (retval) 2203 return retval; 2204 2205 if (ext4_has_inline_data(dir)) { 2206 retval = ext4_try_add_inline_entry(handle, &fname, dir, inode); 2207 if (retval < 0) 2208 goto out; 2209 if (retval == 1) { 2210 retval = 0; 2211 goto out; 2212 } 2213 } 2214 2215 if (is_dx(dir)) { 2216 retval = ext4_dx_add_entry(handle, &fname, dir, inode); 2217 if (!retval || (retval != ERR_BAD_DX_DIR)) 2218 goto out; 2219 /* Can we just ignore htree data? */ 2220 if (ext4_has_metadata_csum(sb)) { 2221 EXT4_ERROR_INODE(dir, 2222 "Directory has corrupted htree index."); 2223 retval = -EFSCORRUPTED; 2224 goto out; 2225 } 2226 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX); 2227 dx_fallback++; 2228 retval = ext4_mark_inode_dirty(handle, dir); 2229 if (unlikely(retval)) 2230 goto out; 2231 } 2232 blocks = dir->i_size >> sb->s_blocksize_bits; 2233 for (block = 0; block < blocks; block++) { 2234 bh = ext4_read_dirblock(dir, block, DIRENT); 2235 if (bh == NULL) { 2236 bh = ext4_bread(handle, dir, block, 2237 EXT4_GET_BLOCKS_CREATE); 2238 goto add_to_new_block; 2239 } 2240 if (IS_ERR(bh)) { 2241 retval = PTR_ERR(bh); 2242 bh = NULL; 2243 goto out; 2244 } 2245 retval = add_dirent_to_buf(handle, &fname, dir, inode, 2246 NULL, bh); 2247 if (retval != -ENOSPC) 2248 goto out; 2249 2250 if (blocks == 1 && !dx_fallback && 2251 ext4_has_feature_dir_index(sb)) { 2252 retval = make_indexed_dir(handle, &fname, dir, 2253 inode, bh); 2254 bh = NULL; /* make_indexed_dir releases bh */ 2255 goto out; 2256 } 2257 brelse(bh); 2258 } 2259 bh = ext4_append(handle, dir, &block); 2260 add_to_new_block: 2261 if (IS_ERR(bh)) { 2262 retval = PTR_ERR(bh); 2263 bh = NULL; 2264 goto out; 2265 } 2266 de = (struct ext4_dir_entry_2 *) bh->b_data; 2267 de->inode = 0; 2268 de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize); 2269 2270 if (csum_size) 2271 ext4_initialize_dirent_tail(bh, blocksize); 2272 2273 retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh); 2274 out: 2275 ext4_fname_free_filename(&fname); 2276 brelse(bh); 2277 if (retval == 0) 2278 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY); 2279 return retval; 2280 } 2281 2282 /* 2283 * Returns 0 for success, or a negative error value 2284 */ 2285 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname, 2286 struct inode *dir, struct inode *inode) 2287 { 2288 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 2289 struct dx_entry *entries, *at; 2290 struct buffer_head *bh; 2291 struct super_block *sb = dir->i_sb; 2292 struct ext4_dir_entry_2 *de; 2293 int restart; 2294 int err; 2295 2296 again: 2297 restart = 0; 2298 frame = dx_probe(fname, dir, NULL, frames); 2299 if (IS_ERR(frame)) 2300 return PTR_ERR(frame); 2301 entries = frame->entries; 2302 at = frame->at; 2303 bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT_HTREE); 2304 if (IS_ERR(bh)) { 2305 err = PTR_ERR(bh); 2306 bh = NULL; 2307 goto cleanup; 2308 } 2309 2310 BUFFER_TRACE(bh, "get_write_access"); 2311 err = ext4_journal_get_write_access(handle, bh); 2312 if (err) 2313 goto journal_error; 2314 2315 err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh); 2316 if (err != -ENOSPC) 2317 goto cleanup; 2318 2319 err = 0; 2320 /* Block full, should compress but for now just split */ 2321 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n", 2322 dx_get_count(entries), dx_get_limit(entries))); 2323 /* Need to split index? */ 2324 if (dx_get_count(entries) == dx_get_limit(entries)) { 2325 ext4_lblk_t newblock; 2326 int levels = frame - frames + 1; 2327 unsigned int icount; 2328 int add_level = 1; 2329 struct dx_entry *entries2; 2330 struct dx_node *node2; 2331 struct buffer_head *bh2; 2332 2333 while (frame > frames) { 2334 if (dx_get_count((frame - 1)->entries) < 2335 dx_get_limit((frame - 1)->entries)) { 2336 add_level = 0; 2337 break; 2338 } 2339 frame--; /* split higher index block */ 2340 at = frame->at; 2341 entries = frame->entries; 2342 restart = 1; 2343 } 2344 if (add_level && levels == ext4_dir_htree_level(sb)) { 2345 ext4_warning(sb, "Directory (ino: %lu) index full, " 2346 "reach max htree level :%d", 2347 dir->i_ino, levels); 2348 if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) { 2349 ext4_warning(sb, "Large directory feature is " 2350 "not enabled on this " 2351 "filesystem"); 2352 } 2353 err = -ENOSPC; 2354 goto cleanup; 2355 } 2356 icount = dx_get_count(entries); 2357 bh2 = ext4_append(handle, dir, &newblock); 2358 if (IS_ERR(bh2)) { 2359 err = PTR_ERR(bh2); 2360 goto cleanup; 2361 } 2362 node2 = (struct dx_node *)(bh2->b_data); 2363 entries2 = node2->entries; 2364 memset(&node2->fake, 0, sizeof(struct fake_dirent)); 2365 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize, 2366 sb->s_blocksize); 2367 BUFFER_TRACE(frame->bh, "get_write_access"); 2368 err = ext4_journal_get_write_access(handle, frame->bh); 2369 if (err) 2370 goto journal_error; 2371 if (!add_level) { 2372 unsigned icount1 = icount/2, icount2 = icount - icount1; 2373 unsigned hash2 = dx_get_hash(entries + icount1); 2374 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n", 2375 icount1, icount2)); 2376 2377 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */ 2378 err = ext4_journal_get_write_access(handle, 2379 (frame - 1)->bh); 2380 if (err) 2381 goto journal_error; 2382 2383 memcpy((char *) entries2, (char *) (entries + icount1), 2384 icount2 * sizeof(struct dx_entry)); 2385 dx_set_count(entries, icount1); 2386 dx_set_count(entries2, icount2); 2387 dx_set_limit(entries2, dx_node_limit(dir)); 2388 2389 /* Which index block gets the new entry? */ 2390 if (at - entries >= icount1) { 2391 frame->at = at = at - entries - icount1 + entries2; 2392 frame->entries = entries = entries2; 2393 swap(frame->bh, bh2); 2394 } 2395 dx_insert_block((frame - 1), hash2, newblock); 2396 dxtrace(dx_show_index("node", frame->entries)); 2397 dxtrace(dx_show_index("node", 2398 ((struct dx_node *) bh2->b_data)->entries)); 2399 err = ext4_handle_dirty_dx_node(handle, dir, bh2); 2400 if (err) 2401 goto journal_error; 2402 brelse (bh2); 2403 err = ext4_handle_dirty_dx_node(handle, dir, 2404 (frame - 1)->bh); 2405 if (err) 2406 goto journal_error; 2407 if (restart) { 2408 err = ext4_handle_dirty_dx_node(handle, dir, 2409 frame->bh); 2410 goto journal_error; 2411 } 2412 } else { 2413 struct dx_root *dxroot; 2414 memcpy((char *) entries2, (char *) entries, 2415 icount * sizeof(struct dx_entry)); 2416 dx_set_limit(entries2, dx_node_limit(dir)); 2417 2418 /* Set up root */ 2419 dx_set_count(entries, 1); 2420 dx_set_block(entries + 0, newblock); 2421 dxroot = (struct dx_root *)frames[0].bh->b_data; 2422 dxroot->info.indirect_levels += 1; 2423 dxtrace(printk(KERN_DEBUG 2424 "Creating %d level index...\n", 2425 dxroot->info.indirect_levels)); 2426 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 2427 if (err) 2428 goto journal_error; 2429 err = ext4_handle_dirty_dx_node(handle, dir, bh2); 2430 brelse(bh2); 2431 restart = 1; 2432 goto journal_error; 2433 } 2434 } 2435 de = do_split(handle, dir, &bh, frame, &fname->hinfo); 2436 if (IS_ERR(de)) { 2437 err = PTR_ERR(de); 2438 goto cleanup; 2439 } 2440 err = add_dirent_to_buf(handle, fname, dir, inode, de, bh); 2441 goto cleanup; 2442 2443 journal_error: 2444 ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */ 2445 cleanup: 2446 brelse(bh); 2447 dx_release(frames); 2448 /* @restart is true means htree-path has been changed, we need to 2449 * repeat dx_probe() to find out valid htree-path 2450 */ 2451 if (restart && err == 0) 2452 goto again; 2453 return err; 2454 } 2455 2456 /* 2457 * ext4_generic_delete_entry deletes a directory entry by merging it 2458 * with the previous entry 2459 */ 2460 int ext4_generic_delete_entry(struct inode *dir, 2461 struct ext4_dir_entry_2 *de_del, 2462 struct buffer_head *bh, 2463 void *entry_buf, 2464 int buf_size, 2465 int csum_size) 2466 { 2467 struct ext4_dir_entry_2 *de, *pde; 2468 unsigned int blocksize = dir->i_sb->s_blocksize; 2469 int i; 2470 2471 i = 0; 2472 pde = NULL; 2473 de = (struct ext4_dir_entry_2 *)entry_buf; 2474 while (i < buf_size - csum_size) { 2475 if (ext4_check_dir_entry(dir, NULL, de, bh, 2476 entry_buf, buf_size, i)) 2477 return -EFSCORRUPTED; 2478 if (de == de_del) { 2479 if (pde) 2480 pde->rec_len = ext4_rec_len_to_disk( 2481 ext4_rec_len_from_disk(pde->rec_len, 2482 blocksize) + 2483 ext4_rec_len_from_disk(de->rec_len, 2484 blocksize), 2485 blocksize); 2486 else 2487 de->inode = 0; 2488 inode_inc_iversion(dir); 2489 return 0; 2490 } 2491 i += ext4_rec_len_from_disk(de->rec_len, blocksize); 2492 pde = de; 2493 de = ext4_next_entry(de, blocksize); 2494 } 2495 return -ENOENT; 2496 } 2497 2498 static int ext4_delete_entry(handle_t *handle, 2499 struct inode *dir, 2500 struct ext4_dir_entry_2 *de_del, 2501 struct buffer_head *bh) 2502 { 2503 int err, csum_size = 0; 2504 2505 if (ext4_has_inline_data(dir)) { 2506 int has_inline_data = 1; 2507 err = ext4_delete_inline_entry(handle, dir, de_del, bh, 2508 &has_inline_data); 2509 if (has_inline_data) 2510 return err; 2511 } 2512 2513 if (ext4_has_metadata_csum(dir->i_sb)) 2514 csum_size = sizeof(struct ext4_dir_entry_tail); 2515 2516 BUFFER_TRACE(bh, "get_write_access"); 2517 err = ext4_journal_get_write_access(handle, bh); 2518 if (unlikely(err)) 2519 goto out; 2520 2521 err = ext4_generic_delete_entry(dir, de_del, bh, bh->b_data, 2522 dir->i_sb->s_blocksize, csum_size); 2523 if (err) 2524 goto out; 2525 2526 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); 2527 err = ext4_handle_dirty_dirblock(handle, dir, bh); 2528 if (unlikely(err)) 2529 goto out; 2530 2531 return 0; 2532 out: 2533 if (err != -ENOENT) 2534 ext4_std_error(dir->i_sb, err); 2535 return err; 2536 } 2537 2538 /* 2539 * Set directory link count to 1 if nlinks > EXT4_LINK_MAX, or if nlinks == 2 2540 * since this indicates that nlinks count was previously 1 to avoid overflowing 2541 * the 16-bit i_links_count field on disk. Directories with i_nlink == 1 mean 2542 * that subdirectory link counts are not being maintained accurately. 2543 * 2544 * The caller has already checked for i_nlink overflow in case the DIR_LINK 2545 * feature is not enabled and returned -EMLINK. The is_dx() check is a proxy 2546 * for checking S_ISDIR(inode) (since the INODE_INDEX feature will not be set 2547 * on regular files) and to avoid creating huge/slow non-HTREE directories. 2548 */ 2549 static void ext4_inc_count(struct inode *inode) 2550 { 2551 inc_nlink(inode); 2552 if (is_dx(inode) && 2553 (inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2)) 2554 set_nlink(inode, 1); 2555 } 2556 2557 /* 2558 * If a directory had nlink == 1, then we should let it be 1. This indicates 2559 * directory has >EXT4_LINK_MAX subdirs. 2560 */ 2561 static void ext4_dec_count(struct inode *inode) 2562 { 2563 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2) 2564 drop_nlink(inode); 2565 } 2566 2567 2568 /* 2569 * Add non-directory inode to a directory. On success, the inode reference is 2570 * consumed by dentry is instantiation. This is also indicated by clearing of 2571 * *inodep pointer. On failure, the caller is responsible for dropping the 2572 * inode reference in the safe context. 2573 */ 2574 static int ext4_add_nondir(handle_t *handle, 2575 struct dentry *dentry, struct inode **inodep) 2576 { 2577 struct inode *dir = d_inode(dentry->d_parent); 2578 struct inode *inode = *inodep; 2579 int err = ext4_add_entry(handle, dentry, inode); 2580 if (!err) { 2581 err = ext4_mark_inode_dirty(handle, inode); 2582 if (IS_DIRSYNC(dir)) 2583 ext4_handle_sync(handle); 2584 d_instantiate_new(dentry, inode); 2585 *inodep = NULL; 2586 return err; 2587 } 2588 drop_nlink(inode); 2589 ext4_orphan_add(handle, inode); 2590 unlock_new_inode(inode); 2591 return err; 2592 } 2593 2594 /* 2595 * By the time this is called, we already have created 2596 * the directory cache entry for the new file, but it 2597 * is so far negative - it has no inode. 2598 * 2599 * If the create succeeds, we fill in the inode information 2600 * with d_instantiate(). 2601 */ 2602 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode, 2603 bool excl) 2604 { 2605 handle_t *handle; 2606 struct inode *inode; 2607 int err, credits, retries = 0; 2608 2609 err = dquot_initialize(dir); 2610 if (err) 2611 return err; 2612 2613 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2614 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2615 retry: 2616 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0, 2617 NULL, EXT4_HT_DIR, credits); 2618 handle = ext4_journal_current_handle(); 2619 err = PTR_ERR(inode); 2620 if (!IS_ERR(inode)) { 2621 inode->i_op = &ext4_file_inode_operations; 2622 inode->i_fop = &ext4_file_operations; 2623 ext4_set_aops(inode); 2624 err = ext4_add_nondir(handle, dentry, &inode); 2625 if (!err) 2626 ext4_fc_track_create(handle, dentry); 2627 } 2628 if (handle) 2629 ext4_journal_stop(handle); 2630 if (!IS_ERR_OR_NULL(inode)) 2631 iput(inode); 2632 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2633 goto retry; 2634 return err; 2635 } 2636 2637 static int ext4_mknod(struct inode *dir, struct dentry *dentry, 2638 umode_t mode, dev_t rdev) 2639 { 2640 handle_t *handle; 2641 struct inode *inode; 2642 int err, credits, retries = 0; 2643 2644 err = dquot_initialize(dir); 2645 if (err) 2646 return err; 2647 2648 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2649 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2650 retry: 2651 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0, 2652 NULL, EXT4_HT_DIR, credits); 2653 handle = ext4_journal_current_handle(); 2654 err = PTR_ERR(inode); 2655 if (!IS_ERR(inode)) { 2656 init_special_inode(inode, inode->i_mode, rdev); 2657 inode->i_op = &ext4_special_inode_operations; 2658 err = ext4_add_nondir(handle, dentry, &inode); 2659 if (!err) 2660 ext4_fc_track_create(handle, dentry); 2661 } 2662 if (handle) 2663 ext4_journal_stop(handle); 2664 if (!IS_ERR_OR_NULL(inode)) 2665 iput(inode); 2666 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2667 goto retry; 2668 return err; 2669 } 2670 2671 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) 2672 { 2673 handle_t *handle; 2674 struct inode *inode; 2675 int err, retries = 0; 2676 2677 err = dquot_initialize(dir); 2678 if (err) 2679 return err; 2680 2681 retry: 2682 inode = ext4_new_inode_start_handle(dir, mode, 2683 NULL, 0, NULL, 2684 EXT4_HT_DIR, 2685 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) + 2686 4 + EXT4_XATTR_TRANS_BLOCKS); 2687 handle = ext4_journal_current_handle(); 2688 err = PTR_ERR(inode); 2689 if (!IS_ERR(inode)) { 2690 inode->i_op = &ext4_file_inode_operations; 2691 inode->i_fop = &ext4_file_operations; 2692 ext4_set_aops(inode); 2693 d_tmpfile(dentry, inode); 2694 err = ext4_orphan_add(handle, inode); 2695 if (err) 2696 goto err_unlock_inode; 2697 mark_inode_dirty(inode); 2698 unlock_new_inode(inode); 2699 } 2700 if (handle) 2701 ext4_journal_stop(handle); 2702 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2703 goto retry; 2704 return err; 2705 err_unlock_inode: 2706 ext4_journal_stop(handle); 2707 unlock_new_inode(inode); 2708 return err; 2709 } 2710 2711 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode, 2712 struct ext4_dir_entry_2 *de, 2713 int blocksize, int csum_size, 2714 unsigned int parent_ino, int dotdot_real_len) 2715 { 2716 de->inode = cpu_to_le32(inode->i_ino); 2717 de->name_len = 1; 2718 de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len), 2719 blocksize); 2720 strcpy(de->name, "."); 2721 ext4_set_de_type(inode->i_sb, de, S_IFDIR); 2722 2723 de = ext4_next_entry(de, blocksize); 2724 de->inode = cpu_to_le32(parent_ino); 2725 de->name_len = 2; 2726 if (!dotdot_real_len) 2727 de->rec_len = ext4_rec_len_to_disk(blocksize - 2728 (csum_size + EXT4_DIR_REC_LEN(1)), 2729 blocksize); 2730 else 2731 de->rec_len = ext4_rec_len_to_disk( 2732 EXT4_DIR_REC_LEN(de->name_len), blocksize); 2733 strcpy(de->name, ".."); 2734 ext4_set_de_type(inode->i_sb, de, S_IFDIR); 2735 2736 return ext4_next_entry(de, blocksize); 2737 } 2738 2739 int ext4_init_new_dir(handle_t *handle, struct inode *dir, 2740 struct inode *inode) 2741 { 2742 struct buffer_head *dir_block = NULL; 2743 struct ext4_dir_entry_2 *de; 2744 ext4_lblk_t block = 0; 2745 unsigned int blocksize = dir->i_sb->s_blocksize; 2746 int csum_size = 0; 2747 int err; 2748 2749 if (ext4_has_metadata_csum(dir->i_sb)) 2750 csum_size = sizeof(struct ext4_dir_entry_tail); 2751 2752 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) { 2753 err = ext4_try_create_inline_dir(handle, dir, inode); 2754 if (err < 0 && err != -ENOSPC) 2755 goto out; 2756 if (!err) 2757 goto out; 2758 } 2759 2760 inode->i_size = 0; 2761 dir_block = ext4_append(handle, inode, &block); 2762 if (IS_ERR(dir_block)) 2763 return PTR_ERR(dir_block); 2764 de = (struct ext4_dir_entry_2 *)dir_block->b_data; 2765 ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0); 2766 set_nlink(inode, 2); 2767 if (csum_size) 2768 ext4_initialize_dirent_tail(dir_block, blocksize); 2769 2770 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata"); 2771 err = ext4_handle_dirty_dirblock(handle, inode, dir_block); 2772 if (err) 2773 goto out; 2774 set_buffer_verified(dir_block); 2775 out: 2776 brelse(dir_block); 2777 return err; 2778 } 2779 2780 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) 2781 { 2782 handle_t *handle; 2783 struct inode *inode; 2784 int err, err2 = 0, credits, retries = 0; 2785 2786 if (EXT4_DIR_LINK_MAX(dir)) 2787 return -EMLINK; 2788 2789 err = dquot_initialize(dir); 2790 if (err) 2791 return err; 2792 2793 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2794 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2795 retry: 2796 inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode, 2797 &dentry->d_name, 2798 0, NULL, EXT4_HT_DIR, credits); 2799 handle = ext4_journal_current_handle(); 2800 err = PTR_ERR(inode); 2801 if (IS_ERR(inode)) 2802 goto out_stop; 2803 2804 inode->i_op = &ext4_dir_inode_operations; 2805 inode->i_fop = &ext4_dir_operations; 2806 err = ext4_init_new_dir(handle, dir, inode); 2807 if (err) 2808 goto out_clear_inode; 2809 err = ext4_mark_inode_dirty(handle, inode); 2810 if (!err) 2811 err = ext4_add_entry(handle, dentry, inode); 2812 if (err) { 2813 out_clear_inode: 2814 clear_nlink(inode); 2815 ext4_orphan_add(handle, inode); 2816 unlock_new_inode(inode); 2817 err2 = ext4_mark_inode_dirty(handle, inode); 2818 if (unlikely(err2)) 2819 err = err2; 2820 ext4_journal_stop(handle); 2821 iput(inode); 2822 goto out_retry; 2823 } 2824 ext4_inc_count(dir); 2825 2826 ext4_update_dx_flag(dir); 2827 err = ext4_mark_inode_dirty(handle, dir); 2828 if (err) 2829 goto out_clear_inode; 2830 d_instantiate_new(dentry, inode); 2831 ext4_fc_track_create(handle, dentry); 2832 if (IS_DIRSYNC(dir)) 2833 ext4_handle_sync(handle); 2834 2835 out_stop: 2836 if (handle) 2837 ext4_journal_stop(handle); 2838 out_retry: 2839 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2840 goto retry; 2841 return err; 2842 } 2843 2844 /* 2845 * routine to check that the specified directory is empty (for rmdir) 2846 */ 2847 bool ext4_empty_dir(struct inode *inode) 2848 { 2849 unsigned int offset; 2850 struct buffer_head *bh; 2851 struct ext4_dir_entry_2 *de; 2852 struct super_block *sb; 2853 2854 if (ext4_has_inline_data(inode)) { 2855 int has_inline_data = 1; 2856 int ret; 2857 2858 ret = empty_inline_dir(inode, &has_inline_data); 2859 if (has_inline_data) 2860 return ret; 2861 } 2862 2863 sb = inode->i_sb; 2864 if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) { 2865 EXT4_ERROR_INODE(inode, "invalid size"); 2866 return true; 2867 } 2868 /* The first directory block must not be a hole, 2869 * so treat it as DIRENT_HTREE 2870 */ 2871 bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE); 2872 if (IS_ERR(bh)) 2873 return true; 2874 2875 de = (struct ext4_dir_entry_2 *) bh->b_data; 2876 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size, 2877 0) || 2878 le32_to_cpu(de->inode) != inode->i_ino || strcmp(".", de->name)) { 2879 ext4_warning_inode(inode, "directory missing '.'"); 2880 brelse(bh); 2881 return true; 2882 } 2883 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); 2884 de = ext4_next_entry(de, sb->s_blocksize); 2885 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size, 2886 offset) || 2887 le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) { 2888 ext4_warning_inode(inode, "directory missing '..'"); 2889 brelse(bh); 2890 return true; 2891 } 2892 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); 2893 while (offset < inode->i_size) { 2894 if (!(offset & (sb->s_blocksize - 1))) { 2895 unsigned int lblock; 2896 brelse(bh); 2897 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb); 2898 bh = ext4_read_dirblock(inode, lblock, EITHER); 2899 if (bh == NULL) { 2900 offset += sb->s_blocksize; 2901 continue; 2902 } 2903 if (IS_ERR(bh)) 2904 return true; 2905 } 2906 de = (struct ext4_dir_entry_2 *) (bh->b_data + 2907 (offset & (sb->s_blocksize - 1))); 2908 if (ext4_check_dir_entry(inode, NULL, de, bh, 2909 bh->b_data, bh->b_size, offset)) { 2910 offset = (offset | (sb->s_blocksize - 1)) + 1; 2911 continue; 2912 } 2913 if (le32_to_cpu(de->inode)) { 2914 brelse(bh); 2915 return false; 2916 } 2917 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); 2918 } 2919 brelse(bh); 2920 return true; 2921 } 2922 2923 /* 2924 * ext4_orphan_add() links an unlinked or truncated inode into a list of 2925 * such inodes, starting at the superblock, in case we crash before the 2926 * file is closed/deleted, or in case the inode truncate spans multiple 2927 * transactions and the last transaction is not recovered after a crash. 2928 * 2929 * At filesystem recovery time, we walk this list deleting unlinked 2930 * inodes and truncating linked inodes in ext4_orphan_cleanup(). 2931 * 2932 * Orphan list manipulation functions must be called under i_mutex unless 2933 * we are just creating the inode or deleting it. 2934 */ 2935 int ext4_orphan_add(handle_t *handle, struct inode *inode) 2936 { 2937 struct super_block *sb = inode->i_sb; 2938 struct ext4_sb_info *sbi = EXT4_SB(sb); 2939 struct ext4_iloc iloc; 2940 int err = 0, rc; 2941 bool dirty = false; 2942 2943 if (!sbi->s_journal || is_bad_inode(inode)) 2944 return 0; 2945 2946 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) && 2947 !inode_is_locked(inode)); 2948 /* 2949 * Exit early if inode already is on orphan list. This is a big speedup 2950 * since we don't have to contend on the global s_orphan_lock. 2951 */ 2952 if (!list_empty(&EXT4_I(inode)->i_orphan)) 2953 return 0; 2954 2955 /* 2956 * Orphan handling is only valid for files with data blocks 2957 * being truncated, or files being unlinked. Note that we either 2958 * hold i_mutex, or the inode can not be referenced from outside, 2959 * so i_nlink should not be bumped due to race 2960 */ 2961 J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 2962 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0); 2963 2964 BUFFER_TRACE(sbi->s_sbh, "get_write_access"); 2965 err = ext4_journal_get_write_access(handle, sbi->s_sbh); 2966 if (err) 2967 goto out; 2968 2969 err = ext4_reserve_inode_write(handle, inode, &iloc); 2970 if (err) 2971 goto out; 2972 2973 mutex_lock(&sbi->s_orphan_lock); 2974 /* 2975 * Due to previous errors inode may be already a part of on-disk 2976 * orphan list. If so skip on-disk list modification. 2977 */ 2978 if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) > 2979 (le32_to_cpu(sbi->s_es->s_inodes_count))) { 2980 /* Insert this inode at the head of the on-disk orphan list */ 2981 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan); 2982 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino); 2983 dirty = true; 2984 } 2985 list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan); 2986 mutex_unlock(&sbi->s_orphan_lock); 2987 2988 if (dirty) { 2989 err = ext4_handle_dirty_super(handle, sb); 2990 rc = ext4_mark_iloc_dirty(handle, inode, &iloc); 2991 if (!err) 2992 err = rc; 2993 if (err) { 2994 /* 2995 * We have to remove inode from in-memory list if 2996 * addition to on disk orphan list failed. Stray orphan 2997 * list entries can cause panics at unmount time. 2998 */ 2999 mutex_lock(&sbi->s_orphan_lock); 3000 list_del_init(&EXT4_I(inode)->i_orphan); 3001 mutex_unlock(&sbi->s_orphan_lock); 3002 } 3003 } else 3004 brelse(iloc.bh); 3005 3006 jbd_debug(4, "superblock will point to %lu\n", inode->i_ino); 3007 jbd_debug(4, "orphan inode %lu will point to %d\n", 3008 inode->i_ino, NEXT_ORPHAN(inode)); 3009 out: 3010 ext4_std_error(sb, err); 3011 return err; 3012 } 3013 3014 /* 3015 * ext4_orphan_del() removes an unlinked or truncated inode from the list 3016 * of such inodes stored on disk, because it is finally being cleaned up. 3017 */ 3018 int ext4_orphan_del(handle_t *handle, struct inode *inode) 3019 { 3020 struct list_head *prev; 3021 struct ext4_inode_info *ei = EXT4_I(inode); 3022 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 3023 __u32 ino_next; 3024 struct ext4_iloc iloc; 3025 int err = 0; 3026 3027 if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS)) 3028 return 0; 3029 3030 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) && 3031 !inode_is_locked(inode)); 3032 /* Do this quick check before taking global s_orphan_lock. */ 3033 if (list_empty(&ei->i_orphan)) 3034 return 0; 3035 3036 if (handle) { 3037 /* Grab inode buffer early before taking global s_orphan_lock */ 3038 err = ext4_reserve_inode_write(handle, inode, &iloc); 3039 } 3040 3041 mutex_lock(&sbi->s_orphan_lock); 3042 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino); 3043 3044 prev = ei->i_orphan.prev; 3045 list_del_init(&ei->i_orphan); 3046 3047 /* If we're on an error path, we may not have a valid 3048 * transaction handle with which to update the orphan list on 3049 * disk, but we still need to remove the inode from the linked 3050 * list in memory. */ 3051 if (!handle || err) { 3052 mutex_unlock(&sbi->s_orphan_lock); 3053 goto out_err; 3054 } 3055 3056 ino_next = NEXT_ORPHAN(inode); 3057 if (prev == &sbi->s_orphan) { 3058 jbd_debug(4, "superblock will point to %u\n", ino_next); 3059 BUFFER_TRACE(sbi->s_sbh, "get_write_access"); 3060 err = ext4_journal_get_write_access(handle, sbi->s_sbh); 3061 if (err) { 3062 mutex_unlock(&sbi->s_orphan_lock); 3063 goto out_brelse; 3064 } 3065 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next); 3066 mutex_unlock(&sbi->s_orphan_lock); 3067 err = ext4_handle_dirty_super(handle, inode->i_sb); 3068 } else { 3069 struct ext4_iloc iloc2; 3070 struct inode *i_prev = 3071 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode; 3072 3073 jbd_debug(4, "orphan inode %lu will point to %u\n", 3074 i_prev->i_ino, ino_next); 3075 err = ext4_reserve_inode_write(handle, i_prev, &iloc2); 3076 if (err) { 3077 mutex_unlock(&sbi->s_orphan_lock); 3078 goto out_brelse; 3079 } 3080 NEXT_ORPHAN(i_prev) = ino_next; 3081 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2); 3082 mutex_unlock(&sbi->s_orphan_lock); 3083 } 3084 if (err) 3085 goto out_brelse; 3086 NEXT_ORPHAN(inode) = 0; 3087 err = ext4_mark_iloc_dirty(handle, inode, &iloc); 3088 out_err: 3089 ext4_std_error(inode->i_sb, err); 3090 return err; 3091 3092 out_brelse: 3093 brelse(iloc.bh); 3094 goto out_err; 3095 } 3096 3097 static int ext4_rmdir(struct inode *dir, struct dentry *dentry) 3098 { 3099 int retval; 3100 struct inode *inode; 3101 struct buffer_head *bh; 3102 struct ext4_dir_entry_2 *de; 3103 handle_t *handle = NULL; 3104 3105 if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb)))) 3106 return -EIO; 3107 3108 /* Initialize quotas before so that eventual writes go in 3109 * separate transaction */ 3110 retval = dquot_initialize(dir); 3111 if (retval) 3112 return retval; 3113 retval = dquot_initialize(d_inode(dentry)); 3114 if (retval) 3115 return retval; 3116 3117 retval = -ENOENT; 3118 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); 3119 if (IS_ERR(bh)) 3120 return PTR_ERR(bh); 3121 if (!bh) 3122 goto end_rmdir; 3123 3124 inode = d_inode(dentry); 3125 3126 retval = -EFSCORRUPTED; 3127 if (le32_to_cpu(de->inode) != inode->i_ino) 3128 goto end_rmdir; 3129 3130 retval = -ENOTEMPTY; 3131 if (!ext4_empty_dir(inode)) 3132 goto end_rmdir; 3133 3134 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3135 EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); 3136 if (IS_ERR(handle)) { 3137 retval = PTR_ERR(handle); 3138 handle = NULL; 3139 goto end_rmdir; 3140 } 3141 3142 if (IS_DIRSYNC(dir)) 3143 ext4_handle_sync(handle); 3144 3145 retval = ext4_delete_entry(handle, dir, de, bh); 3146 if (retval) 3147 goto end_rmdir; 3148 if (!EXT4_DIR_LINK_EMPTY(inode)) 3149 ext4_warning_inode(inode, 3150 "empty directory '%.*s' has too many links (%u)", 3151 dentry->d_name.len, dentry->d_name.name, 3152 inode->i_nlink); 3153 inode_inc_iversion(inode); 3154 clear_nlink(inode); 3155 /* There's no need to set i_disksize: the fact that i_nlink is 3156 * zero will ensure that the right thing happens during any 3157 * recovery. */ 3158 inode->i_size = 0; 3159 ext4_orphan_add(handle, inode); 3160 inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode); 3161 retval = ext4_mark_inode_dirty(handle, inode); 3162 if (retval) 3163 goto end_rmdir; 3164 ext4_dec_count(dir); 3165 ext4_update_dx_flag(dir); 3166 ext4_fc_track_unlink(handle, dentry); 3167 retval = ext4_mark_inode_dirty(handle, dir); 3168 3169 #ifdef CONFIG_UNICODE 3170 /* VFS negative dentries are incompatible with Encoding and 3171 * Case-insensitiveness. Eventually we'll want avoid 3172 * invalidating the dentries here, alongside with returning the 3173 * negative dentries at ext4_lookup(), when it is better 3174 * supported by the VFS for the CI case. 3175 */ 3176 if (IS_CASEFOLDED(dir)) 3177 d_invalidate(dentry); 3178 #endif 3179 3180 end_rmdir: 3181 brelse(bh); 3182 if (handle) 3183 ext4_journal_stop(handle); 3184 return retval; 3185 } 3186 3187 int __ext4_unlink(handle_t *handle, struct inode *dir, const struct qstr *d_name, 3188 struct inode *inode) 3189 { 3190 int retval = -ENOENT; 3191 struct buffer_head *bh; 3192 struct ext4_dir_entry_2 *de; 3193 int skip_remove_dentry = 0; 3194 3195 bh = ext4_find_entry(dir, d_name, &de, NULL); 3196 if (IS_ERR(bh)) 3197 return PTR_ERR(bh); 3198 3199 if (!bh) 3200 return -ENOENT; 3201 3202 if (le32_to_cpu(de->inode) != inode->i_ino) { 3203 /* 3204 * It's okay if we find dont find dentry which matches 3205 * the inode. That's because it might have gotten 3206 * renamed to a different inode number 3207 */ 3208 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY) 3209 skip_remove_dentry = 1; 3210 else 3211 goto out; 3212 } 3213 3214 if (IS_DIRSYNC(dir)) 3215 ext4_handle_sync(handle); 3216 3217 if (!skip_remove_dentry) { 3218 retval = ext4_delete_entry(handle, dir, de, bh); 3219 if (retval) 3220 goto out; 3221 dir->i_ctime = dir->i_mtime = current_time(dir); 3222 ext4_update_dx_flag(dir); 3223 retval = ext4_mark_inode_dirty(handle, dir); 3224 if (retval) 3225 goto out; 3226 } else { 3227 retval = 0; 3228 } 3229 if (inode->i_nlink == 0) 3230 ext4_warning_inode(inode, "Deleting file '%.*s' with no links", 3231 d_name->len, d_name->name); 3232 else 3233 drop_nlink(inode); 3234 if (!inode->i_nlink) 3235 ext4_orphan_add(handle, inode); 3236 inode->i_ctime = current_time(inode); 3237 retval = ext4_mark_inode_dirty(handle, inode); 3238 3239 out: 3240 brelse(bh); 3241 return retval; 3242 } 3243 3244 static int ext4_unlink(struct inode *dir, struct dentry *dentry) 3245 { 3246 handle_t *handle; 3247 int retval; 3248 3249 if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb)))) 3250 return -EIO; 3251 3252 trace_ext4_unlink_enter(dir, dentry); 3253 /* 3254 * Initialize quotas before so that eventual writes go 3255 * in separate transaction 3256 */ 3257 retval = dquot_initialize(dir); 3258 if (retval) 3259 goto out_trace; 3260 retval = dquot_initialize(d_inode(dentry)); 3261 if (retval) 3262 goto out_trace; 3263 3264 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3265 EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); 3266 if (IS_ERR(handle)) { 3267 retval = PTR_ERR(handle); 3268 goto out_trace; 3269 } 3270 3271 retval = __ext4_unlink(handle, dir, &dentry->d_name, d_inode(dentry)); 3272 if (!retval) 3273 ext4_fc_track_unlink(handle, dentry); 3274 #ifdef CONFIG_UNICODE 3275 /* VFS negative dentries are incompatible with Encoding and 3276 * Case-insensitiveness. Eventually we'll want avoid 3277 * invalidating the dentries here, alongside with returning the 3278 * negative dentries at ext4_lookup(), when it is better 3279 * supported by the VFS for the CI case. 3280 */ 3281 if (IS_CASEFOLDED(dir)) 3282 d_invalidate(dentry); 3283 #endif 3284 if (handle) 3285 ext4_journal_stop(handle); 3286 3287 out_trace: 3288 trace_ext4_unlink_exit(dentry, retval); 3289 return retval; 3290 } 3291 3292 static int ext4_symlink(struct inode *dir, 3293 struct dentry *dentry, const char *symname) 3294 { 3295 handle_t *handle; 3296 struct inode *inode; 3297 int err, len = strlen(symname); 3298 int credits; 3299 struct fscrypt_str disk_link; 3300 3301 if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb)))) 3302 return -EIO; 3303 3304 err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize, 3305 &disk_link); 3306 if (err) 3307 return err; 3308 3309 err = dquot_initialize(dir); 3310 if (err) 3311 return err; 3312 3313 if ((disk_link.len > EXT4_N_BLOCKS * 4)) { 3314 /* 3315 * For non-fast symlinks, we just allocate inode and put it on 3316 * orphan list in the first transaction => we need bitmap, 3317 * group descriptor, sb, inode block, quota blocks, and 3318 * possibly selinux xattr blocks. 3319 */ 3320 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) + 3321 EXT4_XATTR_TRANS_BLOCKS; 3322 } else { 3323 /* 3324 * Fast symlink. We have to add entry to directory 3325 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS), 3326 * allocate new inode (bitmap, group descriptor, inode block, 3327 * quota blocks, sb is already counted in previous macros). 3328 */ 3329 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3330 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3; 3331 } 3332 3333 inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO, 3334 &dentry->d_name, 0, NULL, 3335 EXT4_HT_DIR, credits); 3336 handle = ext4_journal_current_handle(); 3337 if (IS_ERR(inode)) { 3338 if (handle) 3339 ext4_journal_stop(handle); 3340 return PTR_ERR(inode); 3341 } 3342 3343 if (IS_ENCRYPTED(inode)) { 3344 err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link); 3345 if (err) 3346 goto err_drop_inode; 3347 inode->i_op = &ext4_encrypted_symlink_inode_operations; 3348 } 3349 3350 if ((disk_link.len > EXT4_N_BLOCKS * 4)) { 3351 if (!IS_ENCRYPTED(inode)) 3352 inode->i_op = &ext4_symlink_inode_operations; 3353 inode_nohighmem(inode); 3354 ext4_set_aops(inode); 3355 /* 3356 * We cannot call page_symlink() with transaction started 3357 * because it calls into ext4_write_begin() which can wait 3358 * for transaction commit if we are running out of space 3359 * and thus we deadlock. So we have to stop transaction now 3360 * and restart it when symlink contents is written. 3361 * 3362 * To keep fs consistent in case of crash, we have to put inode 3363 * to orphan list in the mean time. 3364 */ 3365 drop_nlink(inode); 3366 err = ext4_orphan_add(handle, inode); 3367 if (handle) 3368 ext4_journal_stop(handle); 3369 handle = NULL; 3370 if (err) 3371 goto err_drop_inode; 3372 err = __page_symlink(inode, disk_link.name, disk_link.len, 1); 3373 if (err) 3374 goto err_drop_inode; 3375 /* 3376 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS 3377 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified 3378 */ 3379 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3380 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3381 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1); 3382 if (IS_ERR(handle)) { 3383 err = PTR_ERR(handle); 3384 handle = NULL; 3385 goto err_drop_inode; 3386 } 3387 set_nlink(inode, 1); 3388 err = ext4_orphan_del(handle, inode); 3389 if (err) 3390 goto err_drop_inode; 3391 } else { 3392 /* clear the extent format for fast symlink */ 3393 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS); 3394 if (!IS_ENCRYPTED(inode)) { 3395 inode->i_op = &ext4_fast_symlink_inode_operations; 3396 inode->i_link = (char *)&EXT4_I(inode)->i_data; 3397 } 3398 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name, 3399 disk_link.len); 3400 inode->i_size = disk_link.len - 1; 3401 } 3402 EXT4_I(inode)->i_disksize = inode->i_size; 3403 err = ext4_add_nondir(handle, dentry, &inode); 3404 if (handle) 3405 ext4_journal_stop(handle); 3406 if (inode) 3407 iput(inode); 3408 goto out_free_encrypted_link; 3409 3410 err_drop_inode: 3411 if (handle) 3412 ext4_journal_stop(handle); 3413 clear_nlink(inode); 3414 unlock_new_inode(inode); 3415 iput(inode); 3416 out_free_encrypted_link: 3417 if (disk_link.name != (unsigned char *)symname) 3418 kfree(disk_link.name); 3419 return err; 3420 } 3421 3422 int __ext4_link(struct inode *dir, struct inode *inode, struct dentry *dentry) 3423 { 3424 handle_t *handle; 3425 int err, retries = 0; 3426 retry: 3427 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3428 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3429 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1); 3430 if (IS_ERR(handle)) 3431 return PTR_ERR(handle); 3432 3433 if (IS_DIRSYNC(dir)) 3434 ext4_handle_sync(handle); 3435 3436 inode->i_ctime = current_time(inode); 3437 ext4_inc_count(inode); 3438 ihold(inode); 3439 3440 err = ext4_add_entry(handle, dentry, inode); 3441 if (!err) { 3442 err = ext4_mark_inode_dirty(handle, inode); 3443 /* this can happen only for tmpfile being 3444 * linked the first time 3445 */ 3446 if (inode->i_nlink == 1) 3447 ext4_orphan_del(handle, inode); 3448 d_instantiate(dentry, inode); 3449 ext4_fc_track_link(handle, dentry); 3450 } else { 3451 drop_nlink(inode); 3452 iput(inode); 3453 } 3454 ext4_journal_stop(handle); 3455 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 3456 goto retry; 3457 return err; 3458 } 3459 3460 static int ext4_link(struct dentry *old_dentry, 3461 struct inode *dir, struct dentry *dentry) 3462 { 3463 struct inode *inode = d_inode(old_dentry); 3464 int err; 3465 3466 if (inode->i_nlink >= EXT4_LINK_MAX) 3467 return -EMLINK; 3468 3469 err = fscrypt_prepare_link(old_dentry, dir, dentry); 3470 if (err) 3471 return err; 3472 3473 if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) && 3474 (!projid_eq(EXT4_I(dir)->i_projid, 3475 EXT4_I(old_dentry->d_inode)->i_projid))) 3476 return -EXDEV; 3477 3478 err = dquot_initialize(dir); 3479 if (err) 3480 return err; 3481 return __ext4_link(dir, inode, dentry); 3482 } 3483 3484 /* 3485 * Try to find buffer head where contains the parent block. 3486 * It should be the inode block if it is inlined or the 1st block 3487 * if it is a normal dir. 3488 */ 3489 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle, 3490 struct inode *inode, 3491 int *retval, 3492 struct ext4_dir_entry_2 **parent_de, 3493 int *inlined) 3494 { 3495 struct buffer_head *bh; 3496 3497 if (!ext4_has_inline_data(inode)) { 3498 /* The first directory block must not be a hole, so 3499 * treat it as DIRENT_HTREE 3500 */ 3501 bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE); 3502 if (IS_ERR(bh)) { 3503 *retval = PTR_ERR(bh); 3504 return NULL; 3505 } 3506 *parent_de = ext4_next_entry( 3507 (struct ext4_dir_entry_2 *)bh->b_data, 3508 inode->i_sb->s_blocksize); 3509 return bh; 3510 } 3511 3512 *inlined = 1; 3513 return ext4_get_first_inline_block(inode, parent_de, retval); 3514 } 3515 3516 struct ext4_renament { 3517 struct inode *dir; 3518 struct dentry *dentry; 3519 struct inode *inode; 3520 bool is_dir; 3521 int dir_nlink_delta; 3522 3523 /* entry for "dentry" */ 3524 struct buffer_head *bh; 3525 struct ext4_dir_entry_2 *de; 3526 int inlined; 3527 3528 /* entry for ".." in inode if it's a directory */ 3529 struct buffer_head *dir_bh; 3530 struct ext4_dir_entry_2 *parent_de; 3531 int dir_inlined; 3532 }; 3533 3534 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent) 3535 { 3536 int retval; 3537 3538 ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode, 3539 &retval, &ent->parent_de, 3540 &ent->dir_inlined); 3541 if (!ent->dir_bh) 3542 return retval; 3543 if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino) 3544 return -EFSCORRUPTED; 3545 BUFFER_TRACE(ent->dir_bh, "get_write_access"); 3546 return ext4_journal_get_write_access(handle, ent->dir_bh); 3547 } 3548 3549 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent, 3550 unsigned dir_ino) 3551 { 3552 int retval; 3553 3554 ent->parent_de->inode = cpu_to_le32(dir_ino); 3555 BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata"); 3556 if (!ent->dir_inlined) { 3557 if (is_dx(ent->inode)) { 3558 retval = ext4_handle_dirty_dx_node(handle, 3559 ent->inode, 3560 ent->dir_bh); 3561 } else { 3562 retval = ext4_handle_dirty_dirblock(handle, ent->inode, 3563 ent->dir_bh); 3564 } 3565 } else { 3566 retval = ext4_mark_inode_dirty(handle, ent->inode); 3567 } 3568 if (retval) { 3569 ext4_std_error(ent->dir->i_sb, retval); 3570 return retval; 3571 } 3572 return 0; 3573 } 3574 3575 static int ext4_setent(handle_t *handle, struct ext4_renament *ent, 3576 unsigned ino, unsigned file_type) 3577 { 3578 int retval, retval2; 3579 3580 BUFFER_TRACE(ent->bh, "get write access"); 3581 retval = ext4_journal_get_write_access(handle, ent->bh); 3582 if (retval) 3583 return retval; 3584 ent->de->inode = cpu_to_le32(ino); 3585 if (ext4_has_feature_filetype(ent->dir->i_sb)) 3586 ent->de->file_type = file_type; 3587 inode_inc_iversion(ent->dir); 3588 ent->dir->i_ctime = ent->dir->i_mtime = 3589 current_time(ent->dir); 3590 retval = ext4_mark_inode_dirty(handle, ent->dir); 3591 BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata"); 3592 if (!ent->inlined) { 3593 retval2 = ext4_handle_dirty_dirblock(handle, ent->dir, ent->bh); 3594 if (unlikely(retval2)) { 3595 ext4_std_error(ent->dir->i_sb, retval2); 3596 return retval2; 3597 } 3598 } 3599 brelse(ent->bh); 3600 ent->bh = NULL; 3601 3602 return retval; 3603 } 3604 3605 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir, 3606 const struct qstr *d_name) 3607 { 3608 int retval = -ENOENT; 3609 struct buffer_head *bh; 3610 struct ext4_dir_entry_2 *de; 3611 3612 bh = ext4_find_entry(dir, d_name, &de, NULL); 3613 if (IS_ERR(bh)) 3614 return PTR_ERR(bh); 3615 if (bh) { 3616 retval = ext4_delete_entry(handle, dir, de, bh); 3617 brelse(bh); 3618 } 3619 return retval; 3620 } 3621 3622 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent, 3623 int force_reread) 3624 { 3625 int retval; 3626 /* 3627 * ent->de could have moved from under us during htree split, so make 3628 * sure that we are deleting the right entry. We might also be pointing 3629 * to a stale entry in the unused part of ent->bh so just checking inum 3630 * and the name isn't enough. 3631 */ 3632 if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino || 3633 ent->de->name_len != ent->dentry->d_name.len || 3634 strncmp(ent->de->name, ent->dentry->d_name.name, 3635 ent->de->name_len) || 3636 force_reread) { 3637 retval = ext4_find_delete_entry(handle, ent->dir, 3638 &ent->dentry->d_name); 3639 } else { 3640 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh); 3641 if (retval == -ENOENT) { 3642 retval = ext4_find_delete_entry(handle, ent->dir, 3643 &ent->dentry->d_name); 3644 } 3645 } 3646 3647 if (retval) { 3648 ext4_warning_inode(ent->dir, 3649 "Deleting old file: nlink %d, error=%d", 3650 ent->dir->i_nlink, retval); 3651 } 3652 } 3653 3654 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent) 3655 { 3656 if (ent->dir_nlink_delta) { 3657 if (ent->dir_nlink_delta == -1) 3658 ext4_dec_count(ent->dir); 3659 else 3660 ext4_inc_count(ent->dir); 3661 ext4_mark_inode_dirty(handle, ent->dir); 3662 } 3663 } 3664 3665 static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent, 3666 int credits, handle_t **h) 3667 { 3668 struct inode *wh; 3669 handle_t *handle; 3670 int retries = 0; 3671 3672 /* 3673 * for inode block, sb block, group summaries, 3674 * and inode bitmap 3675 */ 3676 credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) + 3677 EXT4_XATTR_TRANS_BLOCKS + 4); 3678 retry: 3679 wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE, 3680 &ent->dentry->d_name, 0, NULL, 3681 EXT4_HT_DIR, credits); 3682 3683 handle = ext4_journal_current_handle(); 3684 if (IS_ERR(wh)) { 3685 if (handle) 3686 ext4_journal_stop(handle); 3687 if (PTR_ERR(wh) == -ENOSPC && 3688 ext4_should_retry_alloc(ent->dir->i_sb, &retries)) 3689 goto retry; 3690 } else { 3691 *h = handle; 3692 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV); 3693 wh->i_op = &ext4_special_inode_operations; 3694 } 3695 return wh; 3696 } 3697 3698 /* 3699 * Anybody can rename anything with this: the permission checks are left to the 3700 * higher-level routines. 3701 * 3702 * n.b. old_{dentry,inode) refers to the source dentry/inode 3703 * while new_{dentry,inode) refers to the destination dentry/inode 3704 * This comes from rename(const char *oldpath, const char *newpath) 3705 */ 3706 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry, 3707 struct inode *new_dir, struct dentry *new_dentry, 3708 unsigned int flags) 3709 { 3710 handle_t *handle = NULL; 3711 struct ext4_renament old = { 3712 .dir = old_dir, 3713 .dentry = old_dentry, 3714 .inode = d_inode(old_dentry), 3715 }; 3716 struct ext4_renament new = { 3717 .dir = new_dir, 3718 .dentry = new_dentry, 3719 .inode = d_inode(new_dentry), 3720 }; 3721 int force_reread; 3722 int retval; 3723 struct inode *whiteout = NULL; 3724 int credits; 3725 u8 old_file_type; 3726 3727 if (new.inode && new.inode->i_nlink == 0) { 3728 EXT4_ERROR_INODE(new.inode, 3729 "target of rename is already freed"); 3730 return -EFSCORRUPTED; 3731 } 3732 3733 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) && 3734 (!projid_eq(EXT4_I(new_dir)->i_projid, 3735 EXT4_I(old_dentry->d_inode)->i_projid))) 3736 return -EXDEV; 3737 3738 retval = dquot_initialize(old.dir); 3739 if (retval) 3740 return retval; 3741 retval = dquot_initialize(new.dir); 3742 if (retval) 3743 return retval; 3744 3745 /* Initialize quotas before so that eventual writes go 3746 * in separate transaction */ 3747 if (new.inode) { 3748 retval = dquot_initialize(new.inode); 3749 if (retval) 3750 return retval; 3751 } 3752 3753 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL); 3754 if (IS_ERR(old.bh)) 3755 return PTR_ERR(old.bh); 3756 /* 3757 * Check for inode number is _not_ due to possible IO errors. 3758 * We might rmdir the source, keep it as pwd of some process 3759 * and merrily kill the link to whatever was created under the 3760 * same name. Goodbye sticky bit ;-< 3761 */ 3762 retval = -ENOENT; 3763 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino) 3764 goto end_rename; 3765 3766 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, 3767 &new.de, &new.inlined); 3768 if (IS_ERR(new.bh)) { 3769 retval = PTR_ERR(new.bh); 3770 new.bh = NULL; 3771 goto end_rename; 3772 } 3773 if (new.bh) { 3774 if (!new.inode) { 3775 brelse(new.bh); 3776 new.bh = NULL; 3777 } 3778 } 3779 if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC)) 3780 ext4_alloc_da_blocks(old.inode); 3781 3782 credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + 3783 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2); 3784 if (!(flags & RENAME_WHITEOUT)) { 3785 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits); 3786 if (IS_ERR(handle)) { 3787 retval = PTR_ERR(handle); 3788 handle = NULL; 3789 goto end_rename; 3790 } 3791 } else { 3792 whiteout = ext4_whiteout_for_rename(&old, credits, &handle); 3793 if (IS_ERR(whiteout)) { 3794 retval = PTR_ERR(whiteout); 3795 whiteout = NULL; 3796 goto end_rename; 3797 } 3798 } 3799 3800 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir)) 3801 ext4_handle_sync(handle); 3802 3803 if (S_ISDIR(old.inode->i_mode)) { 3804 if (new.inode) { 3805 retval = -ENOTEMPTY; 3806 if (!ext4_empty_dir(new.inode)) 3807 goto end_rename; 3808 } else { 3809 retval = -EMLINK; 3810 if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir)) 3811 goto end_rename; 3812 } 3813 retval = ext4_rename_dir_prepare(handle, &old); 3814 if (retval) 3815 goto end_rename; 3816 } 3817 /* 3818 * If we're renaming a file within an inline_data dir and adding or 3819 * setting the new dirent causes a conversion from inline_data to 3820 * extents/blockmap, we need to force the dirent delete code to 3821 * re-read the directory, or else we end up trying to delete a dirent 3822 * from what is now the extent tree root (or a block map). 3823 */ 3824 force_reread = (new.dir->i_ino == old.dir->i_ino && 3825 ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA)); 3826 3827 old_file_type = old.de->file_type; 3828 if (whiteout) { 3829 /* 3830 * Do this before adding a new entry, so the old entry is sure 3831 * to be still pointing to the valid old entry. 3832 */ 3833 retval = ext4_setent(handle, &old, whiteout->i_ino, 3834 EXT4_FT_CHRDEV); 3835 if (retval) 3836 goto end_rename; 3837 retval = ext4_mark_inode_dirty(handle, whiteout); 3838 if (unlikely(retval)) 3839 goto end_rename; 3840 } 3841 if (!new.bh) { 3842 retval = ext4_add_entry(handle, new.dentry, old.inode); 3843 if (retval) 3844 goto end_rename; 3845 } else { 3846 retval = ext4_setent(handle, &new, 3847 old.inode->i_ino, old_file_type); 3848 if (retval) 3849 goto end_rename; 3850 } 3851 if (force_reread) 3852 force_reread = !ext4_test_inode_flag(new.dir, 3853 EXT4_INODE_INLINE_DATA); 3854 3855 /* 3856 * Like most other Unix systems, set the ctime for inodes on a 3857 * rename. 3858 */ 3859 old.inode->i_ctime = current_time(old.inode); 3860 retval = ext4_mark_inode_dirty(handle, old.inode); 3861 if (unlikely(retval)) 3862 goto end_rename; 3863 3864 if (!whiteout) { 3865 /* 3866 * ok, that's it 3867 */ 3868 ext4_rename_delete(handle, &old, force_reread); 3869 } 3870 3871 if (new.inode) { 3872 ext4_dec_count(new.inode); 3873 new.inode->i_ctime = current_time(new.inode); 3874 } 3875 old.dir->i_ctime = old.dir->i_mtime = current_time(old.dir); 3876 ext4_update_dx_flag(old.dir); 3877 if (old.dir_bh) { 3878 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); 3879 if (retval) 3880 goto end_rename; 3881 3882 ext4_dec_count(old.dir); 3883 if (new.inode) { 3884 /* checked ext4_empty_dir above, can't have another 3885 * parent, ext4_dec_count() won't work for many-linked 3886 * dirs */ 3887 clear_nlink(new.inode); 3888 } else { 3889 ext4_inc_count(new.dir); 3890 ext4_update_dx_flag(new.dir); 3891 retval = ext4_mark_inode_dirty(handle, new.dir); 3892 if (unlikely(retval)) 3893 goto end_rename; 3894 } 3895 } 3896 retval = ext4_mark_inode_dirty(handle, old.dir); 3897 if (unlikely(retval)) 3898 goto end_rename; 3899 3900 if (S_ISDIR(old.inode->i_mode)) { 3901 /* 3902 * We disable fast commits here that's because the 3903 * replay code is not yet capable of changing dot dot 3904 * dirents in directories. 3905 */ 3906 ext4_fc_mark_ineligible(old.inode->i_sb, 3907 EXT4_FC_REASON_RENAME_DIR); 3908 } else { 3909 if (new.inode) 3910 ext4_fc_track_unlink(handle, new.dentry); 3911 __ext4_fc_track_link(handle, old.inode, new.dentry); 3912 __ext4_fc_track_unlink(handle, old.inode, old.dentry); 3913 } 3914 3915 if (new.inode) { 3916 retval = ext4_mark_inode_dirty(handle, new.inode); 3917 if (unlikely(retval)) 3918 goto end_rename; 3919 if (!new.inode->i_nlink) 3920 ext4_orphan_add(handle, new.inode); 3921 } 3922 retval = 0; 3923 3924 end_rename: 3925 brelse(old.dir_bh); 3926 brelse(old.bh); 3927 brelse(new.bh); 3928 if (whiteout) { 3929 if (retval) 3930 drop_nlink(whiteout); 3931 unlock_new_inode(whiteout); 3932 iput(whiteout); 3933 } 3934 if (handle) 3935 ext4_journal_stop(handle); 3936 return retval; 3937 } 3938 3939 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry, 3940 struct inode *new_dir, struct dentry *new_dentry) 3941 { 3942 handle_t *handle = NULL; 3943 struct ext4_renament old = { 3944 .dir = old_dir, 3945 .dentry = old_dentry, 3946 .inode = d_inode(old_dentry), 3947 }; 3948 struct ext4_renament new = { 3949 .dir = new_dir, 3950 .dentry = new_dentry, 3951 .inode = d_inode(new_dentry), 3952 }; 3953 u8 new_file_type; 3954 int retval; 3955 struct timespec64 ctime; 3956 3957 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) && 3958 !projid_eq(EXT4_I(new_dir)->i_projid, 3959 EXT4_I(old_dentry->d_inode)->i_projid)) || 3960 (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) && 3961 !projid_eq(EXT4_I(old_dir)->i_projid, 3962 EXT4_I(new_dentry->d_inode)->i_projid))) 3963 return -EXDEV; 3964 3965 retval = dquot_initialize(old.dir); 3966 if (retval) 3967 return retval; 3968 retval = dquot_initialize(new.dir); 3969 if (retval) 3970 return retval; 3971 3972 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, 3973 &old.de, &old.inlined); 3974 if (IS_ERR(old.bh)) 3975 return PTR_ERR(old.bh); 3976 /* 3977 * Check for inode number is _not_ due to possible IO errors. 3978 * We might rmdir the source, keep it as pwd of some process 3979 * and merrily kill the link to whatever was created under the 3980 * same name. Goodbye sticky bit ;-< 3981 */ 3982 retval = -ENOENT; 3983 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino) 3984 goto end_rename; 3985 3986 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, 3987 &new.de, &new.inlined); 3988 if (IS_ERR(new.bh)) { 3989 retval = PTR_ERR(new.bh); 3990 new.bh = NULL; 3991 goto end_rename; 3992 } 3993 3994 /* RENAME_EXCHANGE case: old *and* new must both exist */ 3995 if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino) 3996 goto end_rename; 3997 3998 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, 3999 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + 4000 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2)); 4001 if (IS_ERR(handle)) { 4002 retval = PTR_ERR(handle); 4003 handle = NULL; 4004 goto end_rename; 4005 } 4006 4007 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir)) 4008 ext4_handle_sync(handle); 4009 4010 if (S_ISDIR(old.inode->i_mode)) { 4011 old.is_dir = true; 4012 retval = ext4_rename_dir_prepare(handle, &old); 4013 if (retval) 4014 goto end_rename; 4015 } 4016 if (S_ISDIR(new.inode->i_mode)) { 4017 new.is_dir = true; 4018 retval = ext4_rename_dir_prepare(handle, &new); 4019 if (retval) 4020 goto end_rename; 4021 } 4022 4023 /* 4024 * Other than the special case of overwriting a directory, parents' 4025 * nlink only needs to be modified if this is a cross directory rename. 4026 */ 4027 if (old.dir != new.dir && old.is_dir != new.is_dir) { 4028 old.dir_nlink_delta = old.is_dir ? -1 : 1; 4029 new.dir_nlink_delta = -old.dir_nlink_delta; 4030 retval = -EMLINK; 4031 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) || 4032 (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir))) 4033 goto end_rename; 4034 } 4035 4036 new_file_type = new.de->file_type; 4037 retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type); 4038 if (retval) 4039 goto end_rename; 4040 4041 retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type); 4042 if (retval) 4043 goto end_rename; 4044 4045 /* 4046 * Like most other Unix systems, set the ctime for inodes on a 4047 * rename. 4048 */ 4049 ctime = current_time(old.inode); 4050 old.inode->i_ctime = ctime; 4051 new.inode->i_ctime = ctime; 4052 retval = ext4_mark_inode_dirty(handle, old.inode); 4053 if (unlikely(retval)) 4054 goto end_rename; 4055 retval = ext4_mark_inode_dirty(handle, new.inode); 4056 if (unlikely(retval)) 4057 goto end_rename; 4058 ext4_fc_mark_ineligible(new.inode->i_sb, 4059 EXT4_FC_REASON_CROSS_RENAME); 4060 if (old.dir_bh) { 4061 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); 4062 if (retval) 4063 goto end_rename; 4064 } 4065 if (new.dir_bh) { 4066 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino); 4067 if (retval) 4068 goto end_rename; 4069 } 4070 ext4_update_dir_count(handle, &old); 4071 ext4_update_dir_count(handle, &new); 4072 retval = 0; 4073 4074 end_rename: 4075 brelse(old.dir_bh); 4076 brelse(new.dir_bh); 4077 brelse(old.bh); 4078 brelse(new.bh); 4079 if (handle) 4080 ext4_journal_stop(handle); 4081 return retval; 4082 } 4083 4084 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry, 4085 struct inode *new_dir, struct dentry *new_dentry, 4086 unsigned int flags) 4087 { 4088 int err; 4089 4090 if (unlikely(ext4_forced_shutdown(EXT4_SB(old_dir->i_sb)))) 4091 return -EIO; 4092 4093 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT)) 4094 return -EINVAL; 4095 4096 err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry, 4097 flags); 4098 if (err) 4099 return err; 4100 4101 if (flags & RENAME_EXCHANGE) { 4102 return ext4_cross_rename(old_dir, old_dentry, 4103 new_dir, new_dentry); 4104 } 4105 4106 return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags); 4107 } 4108 4109 /* 4110 * directories can handle most operations... 4111 */ 4112 const struct inode_operations ext4_dir_inode_operations = { 4113 .create = ext4_create, 4114 .lookup = ext4_lookup, 4115 .link = ext4_link, 4116 .unlink = ext4_unlink, 4117 .symlink = ext4_symlink, 4118 .mkdir = ext4_mkdir, 4119 .rmdir = ext4_rmdir, 4120 .mknod = ext4_mknod, 4121 .tmpfile = ext4_tmpfile, 4122 .rename = ext4_rename2, 4123 .setattr = ext4_setattr, 4124 .getattr = ext4_getattr, 4125 .listxattr = ext4_listxattr, 4126 .get_acl = ext4_get_acl, 4127 .set_acl = ext4_set_acl, 4128 .fiemap = ext4_fiemap, 4129 }; 4130 4131 const struct inode_operations ext4_special_inode_operations = { 4132 .setattr = ext4_setattr, 4133 .getattr = ext4_getattr, 4134 .listxattr = ext4_listxattr, 4135 .get_acl = ext4_get_acl, 4136 .set_acl = ext4_set_acl, 4137 }; 4138