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 ext4_map_blocks map; 58 struct buffer_head *bh; 59 int err; 60 61 if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb && 62 ((inode->i_size >> 10) >= 63 EXT4_SB(inode->i_sb)->s_max_dir_size_kb))) 64 return ERR_PTR(-ENOSPC); 65 66 *block = inode->i_size >> inode->i_sb->s_blocksize_bits; 67 map.m_lblk = *block; 68 map.m_len = 1; 69 70 /* 71 * We're appending new directory block. Make sure the block is not 72 * allocated yet, otherwise we will end up corrupting the 73 * directory. 74 */ 75 err = ext4_map_blocks(NULL, inode, &map, 0); 76 if (err < 0) 77 return ERR_PTR(err); 78 if (err) { 79 EXT4_ERROR_INODE(inode, "Logical block already allocated"); 80 return ERR_PTR(-EFSCORRUPTED); 81 } 82 83 bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE); 84 if (IS_ERR(bh)) 85 return bh; 86 inode->i_size += inode->i_sb->s_blocksize; 87 EXT4_I(inode)->i_disksize = inode->i_size; 88 err = ext4_mark_inode_dirty(handle, inode); 89 if (err) 90 goto out; 91 BUFFER_TRACE(bh, "get_write_access"); 92 err = ext4_journal_get_write_access(handle, inode->i_sb, bh, 93 EXT4_JTR_NONE); 94 if (err) 95 goto out; 96 return bh; 97 98 out: 99 brelse(bh); 100 ext4_std_error(inode->i_sb, err); 101 return ERR_PTR(err); 102 } 103 104 static int ext4_dx_csum_verify(struct inode *inode, 105 struct ext4_dir_entry *dirent); 106 107 /* 108 * Hints to ext4_read_dirblock regarding whether we expect a directory 109 * block being read to be an index block, or a block containing 110 * directory entries (and if the latter, whether it was found via a 111 * logical block in an htree index block). This is used to control 112 * what sort of sanity checkinig ext4_read_dirblock() will do on the 113 * directory block read from the storage device. EITHER will means 114 * the caller doesn't know what kind of directory block will be read, 115 * so no specific verification will be done. 116 */ 117 typedef enum { 118 EITHER, INDEX, DIRENT, DIRENT_HTREE 119 } dirblock_type_t; 120 121 #define ext4_read_dirblock(inode, block, type) \ 122 __ext4_read_dirblock((inode), (block), (type), __func__, __LINE__) 123 124 static struct buffer_head *__ext4_read_dirblock(struct inode *inode, 125 ext4_lblk_t block, 126 dirblock_type_t type, 127 const char *func, 128 unsigned int line) 129 { 130 struct buffer_head *bh; 131 struct ext4_dir_entry *dirent; 132 int is_dx_block = 0; 133 134 if (block >= inode->i_size >> inode->i_blkbits) { 135 ext4_error_inode(inode, func, line, block, 136 "Attempting to read directory block (%u) that is past i_size (%llu)", 137 block, inode->i_size); 138 return ERR_PTR(-EFSCORRUPTED); 139 } 140 141 if (ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_EIO)) 142 bh = ERR_PTR(-EIO); 143 else 144 bh = ext4_bread(NULL, inode, block, 0); 145 if (IS_ERR(bh)) { 146 __ext4_warning(inode->i_sb, func, line, 147 "inode #%lu: lblock %lu: comm %s: " 148 "error %ld reading directory block", 149 inode->i_ino, (unsigned long)block, 150 current->comm, PTR_ERR(bh)); 151 152 return bh; 153 } 154 if (!bh && (type == INDEX || type == DIRENT_HTREE)) { 155 ext4_error_inode(inode, func, line, block, 156 "Directory hole found for htree %s block", 157 (type == INDEX) ? "index" : "leaf"); 158 return ERR_PTR(-EFSCORRUPTED); 159 } 160 if (!bh) 161 return NULL; 162 dirent = (struct ext4_dir_entry *) bh->b_data; 163 /* Determine whether or not we have an index block */ 164 if (is_dx(inode)) { 165 if (block == 0) 166 is_dx_block = 1; 167 else if (ext4_rec_len_from_disk(dirent->rec_len, 168 inode->i_sb->s_blocksize) == 169 inode->i_sb->s_blocksize) 170 is_dx_block = 1; 171 } 172 if (!is_dx_block && type == INDEX) { 173 ext4_error_inode(inode, func, line, block, 174 "directory leaf block found instead of index block"); 175 brelse(bh); 176 return ERR_PTR(-EFSCORRUPTED); 177 } 178 if (!ext4_has_metadata_csum(inode->i_sb) || 179 buffer_verified(bh)) 180 return bh; 181 182 /* 183 * An empty leaf block can get mistaken for a index block; for 184 * this reason, we can only check the index checksum when the 185 * caller is sure it should be an index block. 186 */ 187 if (is_dx_block && type == INDEX) { 188 if (ext4_dx_csum_verify(inode, dirent) && 189 !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC)) 190 set_buffer_verified(bh); 191 else { 192 ext4_error_inode_err(inode, func, line, block, 193 EFSBADCRC, 194 "Directory index failed checksum"); 195 brelse(bh); 196 return ERR_PTR(-EFSBADCRC); 197 } 198 } 199 if (!is_dx_block) { 200 if (ext4_dirblock_csum_verify(inode, bh) && 201 !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC)) 202 set_buffer_verified(bh); 203 else { 204 ext4_error_inode_err(inode, func, line, block, 205 EFSBADCRC, 206 "Directory block failed checksum"); 207 brelse(bh); 208 return ERR_PTR(-EFSBADCRC); 209 } 210 } 211 return bh; 212 } 213 214 #ifdef DX_DEBUG 215 #define dxtrace(command) command 216 #else 217 #define dxtrace(command) 218 #endif 219 220 struct fake_dirent 221 { 222 __le32 inode; 223 __le16 rec_len; 224 u8 name_len; 225 u8 file_type; 226 }; 227 228 struct dx_countlimit 229 { 230 __le16 limit; 231 __le16 count; 232 }; 233 234 struct dx_entry 235 { 236 __le32 hash; 237 __le32 block; 238 }; 239 240 /* 241 * dx_root_info is laid out so that if it should somehow get overlaid by a 242 * dirent the two low bits of the hash version will be zero. Therefore, the 243 * hash version mod 4 should never be 0. Sincerely, the paranoia department. 244 */ 245 246 struct dx_root 247 { 248 struct fake_dirent dot; 249 char dot_name[4]; 250 struct fake_dirent dotdot; 251 char dotdot_name[4]; 252 struct dx_root_info 253 { 254 __le32 reserved_zero; 255 u8 hash_version; 256 u8 info_length; /* 8 */ 257 u8 indirect_levels; 258 u8 unused_flags; 259 } 260 info; 261 struct dx_entry entries[]; 262 }; 263 264 struct dx_node 265 { 266 struct fake_dirent fake; 267 struct dx_entry entries[]; 268 }; 269 270 271 struct dx_frame 272 { 273 struct buffer_head *bh; 274 struct dx_entry *entries; 275 struct dx_entry *at; 276 }; 277 278 struct dx_map_entry 279 { 280 u32 hash; 281 u16 offs; 282 u16 size; 283 }; 284 285 /* 286 * This goes at the end of each htree block. 287 */ 288 struct dx_tail { 289 u32 dt_reserved; 290 __le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */ 291 }; 292 293 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry); 294 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value); 295 static inline unsigned dx_get_hash(struct dx_entry *entry); 296 static void dx_set_hash(struct dx_entry *entry, unsigned value); 297 static unsigned dx_get_count(struct dx_entry *entries); 298 static unsigned dx_get_limit(struct dx_entry *entries); 299 static void dx_set_count(struct dx_entry *entries, unsigned value); 300 static void dx_set_limit(struct dx_entry *entries, unsigned value); 301 static unsigned dx_root_limit(struct inode *dir, unsigned infosize); 302 static unsigned dx_node_limit(struct inode *dir); 303 static struct dx_frame *dx_probe(struct ext4_filename *fname, 304 struct inode *dir, 305 struct dx_hash_info *hinfo, 306 struct dx_frame *frame); 307 static void dx_release(struct dx_frame *frames); 308 static int dx_make_map(struct inode *dir, struct buffer_head *bh, 309 struct dx_hash_info *hinfo, 310 struct dx_map_entry *map_tail); 311 static void dx_sort_map(struct dx_map_entry *map, unsigned count); 312 static struct ext4_dir_entry_2 *dx_move_dirents(struct inode *dir, char *from, 313 char *to, struct dx_map_entry *offsets, 314 int count, unsigned int blocksize); 315 static struct ext4_dir_entry_2 *dx_pack_dirents(struct inode *dir, char *base, 316 unsigned int blocksize); 317 static void dx_insert_block(struct dx_frame *frame, 318 u32 hash, ext4_lblk_t block); 319 static int ext4_htree_next_block(struct inode *dir, __u32 hash, 320 struct dx_frame *frame, 321 struct dx_frame *frames, 322 __u32 *start_hash); 323 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, 324 struct ext4_filename *fname, 325 struct ext4_dir_entry_2 **res_dir); 326 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname, 327 struct inode *dir, struct inode *inode); 328 329 /* checksumming functions */ 330 void ext4_initialize_dirent_tail(struct buffer_head *bh, 331 unsigned int blocksize) 332 { 333 struct ext4_dir_entry_tail *t = EXT4_DIRENT_TAIL(bh->b_data, blocksize); 334 335 memset(t, 0, sizeof(struct ext4_dir_entry_tail)); 336 t->det_rec_len = ext4_rec_len_to_disk( 337 sizeof(struct ext4_dir_entry_tail), blocksize); 338 t->det_reserved_ft = EXT4_FT_DIR_CSUM; 339 } 340 341 /* Walk through a dirent block to find a checksum "dirent" at the tail */ 342 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode, 343 struct buffer_head *bh) 344 { 345 struct ext4_dir_entry_tail *t; 346 347 #ifdef PARANOID 348 struct ext4_dir_entry *d, *top; 349 350 d = (struct ext4_dir_entry *)bh->b_data; 351 top = (struct ext4_dir_entry *)(bh->b_data + 352 (EXT4_BLOCK_SIZE(inode->i_sb) - 353 sizeof(struct ext4_dir_entry_tail))); 354 while (d < top && d->rec_len) 355 d = (struct ext4_dir_entry *)(((void *)d) + 356 le16_to_cpu(d->rec_len)); 357 358 if (d != top) 359 return NULL; 360 361 t = (struct ext4_dir_entry_tail *)d; 362 #else 363 t = EXT4_DIRENT_TAIL(bh->b_data, EXT4_BLOCK_SIZE(inode->i_sb)); 364 #endif 365 366 if (t->det_reserved_zero1 || 367 le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) || 368 t->det_reserved_zero2 || 369 t->det_reserved_ft != EXT4_FT_DIR_CSUM) 370 return NULL; 371 372 return t; 373 } 374 375 static __le32 ext4_dirblock_csum(struct inode *inode, void *dirent, int size) 376 { 377 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 378 struct ext4_inode_info *ei = EXT4_I(inode); 379 __u32 csum; 380 381 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size); 382 return cpu_to_le32(csum); 383 } 384 385 #define warn_no_space_for_csum(inode) \ 386 __warn_no_space_for_csum((inode), __func__, __LINE__) 387 388 static void __warn_no_space_for_csum(struct inode *inode, const char *func, 389 unsigned int line) 390 { 391 __ext4_warning_inode(inode, func, line, 392 "No space for directory leaf checksum. Please run e2fsck -D."); 393 } 394 395 int ext4_dirblock_csum_verify(struct inode *inode, struct buffer_head *bh) 396 { 397 struct ext4_dir_entry_tail *t; 398 399 if (!ext4_has_metadata_csum(inode->i_sb)) 400 return 1; 401 402 t = get_dirent_tail(inode, bh); 403 if (!t) { 404 warn_no_space_for_csum(inode); 405 return 0; 406 } 407 408 if (t->det_checksum != ext4_dirblock_csum(inode, bh->b_data, 409 (char *)t - bh->b_data)) 410 return 0; 411 412 return 1; 413 } 414 415 static void ext4_dirblock_csum_set(struct inode *inode, 416 struct buffer_head *bh) 417 { 418 struct ext4_dir_entry_tail *t; 419 420 if (!ext4_has_metadata_csum(inode->i_sb)) 421 return; 422 423 t = get_dirent_tail(inode, bh); 424 if (!t) { 425 warn_no_space_for_csum(inode); 426 return; 427 } 428 429 t->det_checksum = ext4_dirblock_csum(inode, bh->b_data, 430 (char *)t - bh->b_data); 431 } 432 433 int ext4_handle_dirty_dirblock(handle_t *handle, 434 struct inode *inode, 435 struct buffer_head *bh) 436 { 437 ext4_dirblock_csum_set(inode, bh); 438 return ext4_handle_dirty_metadata(handle, inode, bh); 439 } 440 441 static struct dx_countlimit *get_dx_countlimit(struct inode *inode, 442 struct ext4_dir_entry *dirent, 443 int *offset) 444 { 445 struct ext4_dir_entry *dp; 446 struct dx_root_info *root; 447 int count_offset; 448 449 if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb)) 450 count_offset = 8; 451 else if (le16_to_cpu(dirent->rec_len) == 12) { 452 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12); 453 if (le16_to_cpu(dp->rec_len) != 454 EXT4_BLOCK_SIZE(inode->i_sb) - 12) 455 return NULL; 456 root = (struct dx_root_info *)(((void *)dp + 12)); 457 if (root->reserved_zero || 458 root->info_length != sizeof(struct dx_root_info)) 459 return NULL; 460 count_offset = 32; 461 } else 462 return NULL; 463 464 if (offset) 465 *offset = count_offset; 466 return (struct dx_countlimit *)(((void *)dirent) + count_offset); 467 } 468 469 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent, 470 int count_offset, int count, struct dx_tail *t) 471 { 472 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 473 struct ext4_inode_info *ei = EXT4_I(inode); 474 __u32 csum; 475 int size; 476 __u32 dummy_csum = 0; 477 int offset = offsetof(struct dx_tail, dt_checksum); 478 479 size = count_offset + (count * sizeof(struct dx_entry)); 480 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size); 481 csum = ext4_chksum(sbi, csum, (__u8 *)t, offset); 482 csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum)); 483 484 return cpu_to_le32(csum); 485 } 486 487 static int ext4_dx_csum_verify(struct inode *inode, 488 struct ext4_dir_entry *dirent) 489 { 490 struct dx_countlimit *c; 491 struct dx_tail *t; 492 int count_offset, limit, count; 493 494 if (!ext4_has_metadata_csum(inode->i_sb)) 495 return 1; 496 497 c = get_dx_countlimit(inode, dirent, &count_offset); 498 if (!c) { 499 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D."); 500 return 0; 501 } 502 limit = le16_to_cpu(c->limit); 503 count = le16_to_cpu(c->count); 504 if (count_offset + (limit * sizeof(struct dx_entry)) > 505 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) { 506 warn_no_space_for_csum(inode); 507 return 0; 508 } 509 t = (struct dx_tail *)(((struct dx_entry *)c) + limit); 510 511 if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset, 512 count, t)) 513 return 0; 514 return 1; 515 } 516 517 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent) 518 { 519 struct dx_countlimit *c; 520 struct dx_tail *t; 521 int count_offset, limit, count; 522 523 if (!ext4_has_metadata_csum(inode->i_sb)) 524 return; 525 526 c = get_dx_countlimit(inode, dirent, &count_offset); 527 if (!c) { 528 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D."); 529 return; 530 } 531 limit = le16_to_cpu(c->limit); 532 count = le16_to_cpu(c->count); 533 if (count_offset + (limit * sizeof(struct dx_entry)) > 534 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) { 535 warn_no_space_for_csum(inode); 536 return; 537 } 538 t = (struct dx_tail *)(((struct dx_entry *)c) + limit); 539 540 t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t); 541 } 542 543 static inline int ext4_handle_dirty_dx_node(handle_t *handle, 544 struct inode *inode, 545 struct buffer_head *bh) 546 { 547 ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data); 548 return ext4_handle_dirty_metadata(handle, inode, bh); 549 } 550 551 /* 552 * p is at least 6 bytes before the end of page 553 */ 554 static inline struct ext4_dir_entry_2 * 555 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize) 556 { 557 return (struct ext4_dir_entry_2 *)((char *)p + 558 ext4_rec_len_from_disk(p->rec_len, blocksize)); 559 } 560 561 /* 562 * Future: use high four bits of block for coalesce-on-delete flags 563 * Mask them off for now. 564 */ 565 566 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry) 567 { 568 return le32_to_cpu(entry->block) & 0x0fffffff; 569 } 570 571 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value) 572 { 573 entry->block = cpu_to_le32(value); 574 } 575 576 static inline unsigned dx_get_hash(struct dx_entry *entry) 577 { 578 return le32_to_cpu(entry->hash); 579 } 580 581 static inline void dx_set_hash(struct dx_entry *entry, unsigned value) 582 { 583 entry->hash = cpu_to_le32(value); 584 } 585 586 static inline unsigned dx_get_count(struct dx_entry *entries) 587 { 588 return le16_to_cpu(((struct dx_countlimit *) entries)->count); 589 } 590 591 static inline unsigned dx_get_limit(struct dx_entry *entries) 592 { 593 return le16_to_cpu(((struct dx_countlimit *) entries)->limit); 594 } 595 596 static inline void dx_set_count(struct dx_entry *entries, unsigned value) 597 { 598 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value); 599 } 600 601 static inline void dx_set_limit(struct dx_entry *entries, unsigned value) 602 { 603 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value); 604 } 605 606 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize) 607 { 608 unsigned int entry_space = dir->i_sb->s_blocksize - 609 ext4_dir_rec_len(1, NULL) - 610 ext4_dir_rec_len(2, NULL) - infosize; 611 612 if (ext4_has_metadata_csum(dir->i_sb)) 613 entry_space -= sizeof(struct dx_tail); 614 return entry_space / sizeof(struct dx_entry); 615 } 616 617 static inline unsigned dx_node_limit(struct inode *dir) 618 { 619 unsigned int entry_space = dir->i_sb->s_blocksize - 620 ext4_dir_rec_len(0, dir); 621 622 if (ext4_has_metadata_csum(dir->i_sb)) 623 entry_space -= sizeof(struct dx_tail); 624 return entry_space / sizeof(struct dx_entry); 625 } 626 627 /* 628 * Debug 629 */ 630 #ifdef DX_DEBUG 631 static void dx_show_index(char * label, struct dx_entry *entries) 632 { 633 int i, n = dx_get_count (entries); 634 printk(KERN_DEBUG "%s index", label); 635 for (i = 0; i < n; i++) { 636 printk(KERN_CONT " %x->%lu", 637 i ? dx_get_hash(entries + i) : 0, 638 (unsigned long)dx_get_block(entries + i)); 639 } 640 printk(KERN_CONT "\n"); 641 } 642 643 struct stats 644 { 645 unsigned names; 646 unsigned space; 647 unsigned bcount; 648 }; 649 650 static struct stats dx_show_leaf(struct inode *dir, 651 struct dx_hash_info *hinfo, 652 struct ext4_dir_entry_2 *de, 653 int size, int show_names) 654 { 655 unsigned names = 0, space = 0; 656 char *base = (char *) de; 657 struct dx_hash_info h = *hinfo; 658 659 printk("names: "); 660 while ((char *) de < base + size) 661 { 662 if (de->inode) 663 { 664 if (show_names) 665 { 666 #ifdef CONFIG_FS_ENCRYPTION 667 int len; 668 char *name; 669 struct fscrypt_str fname_crypto_str = 670 FSTR_INIT(NULL, 0); 671 int res = 0; 672 673 name = de->name; 674 len = de->name_len; 675 if (!IS_ENCRYPTED(dir)) { 676 /* Directory is not encrypted */ 677 (void) ext4fs_dirhash(dir, de->name, 678 de->name_len, &h); 679 printk("%*.s:(U)%x.%u ", len, 680 name, h.hash, 681 (unsigned) ((char *) de 682 - base)); 683 } else { 684 struct fscrypt_str de_name = 685 FSTR_INIT(name, len); 686 687 /* Directory is encrypted */ 688 res = fscrypt_fname_alloc_buffer( 689 len, &fname_crypto_str); 690 if (res) 691 printk(KERN_WARNING "Error " 692 "allocating crypto " 693 "buffer--skipping " 694 "crypto\n"); 695 res = fscrypt_fname_disk_to_usr(dir, 696 0, 0, &de_name, 697 &fname_crypto_str); 698 if (res) { 699 printk(KERN_WARNING "Error " 700 "converting filename " 701 "from disk to usr" 702 "\n"); 703 name = "??"; 704 len = 2; 705 } else { 706 name = fname_crypto_str.name; 707 len = fname_crypto_str.len; 708 } 709 if (IS_CASEFOLDED(dir)) 710 h.hash = EXT4_DIRENT_HASH(de); 711 else 712 (void) ext4fs_dirhash(dir, 713 de->name, 714 de->name_len, &h); 715 printk("%*.s:(E)%x.%u ", len, name, 716 h.hash, (unsigned) ((char *) de 717 - base)); 718 fscrypt_fname_free_buffer( 719 &fname_crypto_str); 720 } 721 #else 722 int len = de->name_len; 723 char *name = de->name; 724 (void) ext4fs_dirhash(dir, de->name, 725 de->name_len, &h); 726 printk("%*.s:%x.%u ", len, name, h.hash, 727 (unsigned) ((char *) de - base)); 728 #endif 729 } 730 space += ext4_dir_rec_len(de->name_len, dir); 731 names++; 732 } 733 de = ext4_next_entry(de, size); 734 } 735 printk(KERN_CONT "(%i)\n", names); 736 return (struct stats) { names, space, 1 }; 737 } 738 739 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir, 740 struct dx_entry *entries, int levels) 741 { 742 unsigned blocksize = dir->i_sb->s_blocksize; 743 unsigned count = dx_get_count(entries), names = 0, space = 0, i; 744 unsigned bcount = 0; 745 struct buffer_head *bh; 746 printk("%i indexed blocks...\n", count); 747 for (i = 0; i < count; i++, entries++) 748 { 749 ext4_lblk_t block = dx_get_block(entries); 750 ext4_lblk_t hash = i ? dx_get_hash(entries): 0; 751 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash; 752 struct stats stats; 753 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range); 754 bh = ext4_bread(NULL,dir, block, 0); 755 if (!bh || IS_ERR(bh)) 756 continue; 757 stats = levels? 758 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1): 759 dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) 760 bh->b_data, blocksize, 0); 761 names += stats.names; 762 space += stats.space; 763 bcount += stats.bcount; 764 brelse(bh); 765 } 766 if (bcount) 767 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n", 768 levels ? "" : " ", names, space/bcount, 769 (space/bcount)*100/blocksize); 770 return (struct stats) { names, space, bcount}; 771 } 772 773 /* 774 * Linear search cross check 775 */ 776 static inline void htree_rep_invariant_check(struct dx_entry *at, 777 struct dx_entry *target, 778 u32 hash, unsigned int n) 779 { 780 while (n--) { 781 dxtrace(printk(KERN_CONT ",")); 782 if (dx_get_hash(++at) > hash) { 783 at--; 784 break; 785 } 786 } 787 ASSERT(at == target - 1); 788 } 789 #else /* DX_DEBUG */ 790 static inline void htree_rep_invariant_check(struct dx_entry *at, 791 struct dx_entry *target, 792 u32 hash, unsigned int n) 793 { 794 } 795 #endif /* DX_DEBUG */ 796 797 /* 798 * Probe for a directory leaf block to search. 799 * 800 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format 801 * error in the directory index, and the caller should fall back to 802 * searching the directory normally. The callers of dx_probe **MUST** 803 * check for this error code, and make sure it never gets reflected 804 * back to userspace. 805 */ 806 static struct dx_frame * 807 dx_probe(struct ext4_filename *fname, struct inode *dir, 808 struct dx_hash_info *hinfo, struct dx_frame *frame_in) 809 { 810 unsigned count, indirect, level, i; 811 struct dx_entry *at, *entries, *p, *q, *m; 812 struct dx_root *root; 813 struct dx_frame *frame = frame_in; 814 struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR); 815 u32 hash; 816 ext4_lblk_t block; 817 ext4_lblk_t blocks[EXT4_HTREE_LEVEL]; 818 819 memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0])); 820 frame->bh = ext4_read_dirblock(dir, 0, INDEX); 821 if (IS_ERR(frame->bh)) 822 return (struct dx_frame *) frame->bh; 823 824 root = (struct dx_root *) frame->bh->b_data; 825 if (root->info.hash_version != DX_HASH_TEA && 826 root->info.hash_version != DX_HASH_HALF_MD4 && 827 root->info.hash_version != DX_HASH_LEGACY && 828 root->info.hash_version != DX_HASH_SIPHASH) { 829 ext4_warning_inode(dir, "Unrecognised inode hash code %u", 830 root->info.hash_version); 831 goto fail; 832 } 833 if (ext4_hash_in_dirent(dir)) { 834 if (root->info.hash_version != DX_HASH_SIPHASH) { 835 ext4_warning_inode(dir, 836 "Hash in dirent, but hash is not SIPHASH"); 837 goto fail; 838 } 839 } else { 840 if (root->info.hash_version == DX_HASH_SIPHASH) { 841 ext4_warning_inode(dir, 842 "Hash code is SIPHASH, but hash not in dirent"); 843 goto fail; 844 } 845 } 846 if (fname) 847 hinfo = &fname->hinfo; 848 hinfo->hash_version = root->info.hash_version; 849 if (hinfo->hash_version <= DX_HASH_TEA) 850 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; 851 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed; 852 /* hash is already computed for encrypted casefolded directory */ 853 if (fname && fname_name(fname) && 854 !(IS_ENCRYPTED(dir) && IS_CASEFOLDED(dir))) { 855 int ret = ext4fs_dirhash(dir, fname_name(fname), 856 fname_len(fname), hinfo); 857 if (ret < 0) { 858 ret_err = ERR_PTR(ret); 859 goto fail; 860 } 861 } 862 hash = hinfo->hash; 863 864 if (root->info.unused_flags & 1) { 865 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x", 866 root->info.unused_flags); 867 goto fail; 868 } 869 870 indirect = root->info.indirect_levels; 871 if (indirect >= ext4_dir_htree_level(dir->i_sb)) { 872 ext4_warning(dir->i_sb, 873 "Directory (ino: %lu) htree depth %#06x exceed" 874 "supported value", dir->i_ino, 875 ext4_dir_htree_level(dir->i_sb)); 876 if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) { 877 ext4_warning(dir->i_sb, "Enable large directory " 878 "feature to access it"); 879 } 880 goto fail; 881 } 882 883 entries = (struct dx_entry *)(((char *)&root->info) + 884 root->info.info_length); 885 886 if (dx_get_limit(entries) != dx_root_limit(dir, 887 root->info.info_length)) { 888 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u", 889 dx_get_limit(entries), 890 dx_root_limit(dir, root->info.info_length)); 891 goto fail; 892 } 893 894 dxtrace(printk("Look up %x", hash)); 895 level = 0; 896 blocks[0] = 0; 897 while (1) { 898 count = dx_get_count(entries); 899 if (!count || count > dx_get_limit(entries)) { 900 ext4_warning_inode(dir, 901 "dx entry: count %u beyond limit %u", 902 count, dx_get_limit(entries)); 903 goto fail; 904 } 905 906 p = entries + 1; 907 q = entries + count - 1; 908 while (p <= q) { 909 m = p + (q - p) / 2; 910 dxtrace(printk(KERN_CONT ".")); 911 if (dx_get_hash(m) > hash) 912 q = m - 1; 913 else 914 p = m + 1; 915 } 916 917 htree_rep_invariant_check(entries, p, hash, count - 1); 918 919 at = p - 1; 920 dxtrace(printk(KERN_CONT " %x->%u\n", 921 at == entries ? 0 : dx_get_hash(at), 922 dx_get_block(at))); 923 frame->entries = entries; 924 frame->at = at; 925 926 block = dx_get_block(at); 927 for (i = 0; i <= level; i++) { 928 if (blocks[i] == block) { 929 ext4_warning_inode(dir, 930 "dx entry: tree cycle block %u points back to block %u", 931 blocks[level], block); 932 goto fail; 933 } 934 } 935 if (++level > indirect) 936 return frame; 937 blocks[level] = block; 938 frame++; 939 frame->bh = ext4_read_dirblock(dir, block, INDEX); 940 if (IS_ERR(frame->bh)) { 941 ret_err = (struct dx_frame *) frame->bh; 942 frame->bh = NULL; 943 goto fail; 944 } 945 946 entries = ((struct dx_node *) frame->bh->b_data)->entries; 947 948 if (dx_get_limit(entries) != dx_node_limit(dir)) { 949 ext4_warning_inode(dir, 950 "dx entry: limit %u != node limit %u", 951 dx_get_limit(entries), dx_node_limit(dir)); 952 goto fail; 953 } 954 } 955 fail: 956 while (frame >= frame_in) { 957 brelse(frame->bh); 958 frame--; 959 } 960 961 if (ret_err == ERR_PTR(ERR_BAD_DX_DIR)) 962 ext4_warning_inode(dir, 963 "Corrupt directory, running e2fsck is recommended"); 964 return ret_err; 965 } 966 967 static void dx_release(struct dx_frame *frames) 968 { 969 struct dx_root_info *info; 970 int i; 971 unsigned int indirect_levels; 972 973 if (frames[0].bh == NULL) 974 return; 975 976 info = &((struct dx_root *)frames[0].bh->b_data)->info; 977 /* save local copy, "info" may be freed after brelse() */ 978 indirect_levels = info->indirect_levels; 979 for (i = 0; i <= indirect_levels; i++) { 980 if (frames[i].bh == NULL) 981 break; 982 brelse(frames[i].bh); 983 frames[i].bh = NULL; 984 } 985 } 986 987 /* 988 * This function increments the frame pointer to search the next leaf 989 * block, and reads in the necessary intervening nodes if the search 990 * should be necessary. Whether or not the search is necessary is 991 * controlled by the hash parameter. If the hash value is even, then 992 * the search is only continued if the next block starts with that 993 * hash value. This is used if we are searching for a specific file. 994 * 995 * If the hash value is HASH_NB_ALWAYS, then always go to the next block. 996 * 997 * This function returns 1 if the caller should continue to search, 998 * or 0 if it should not. If there is an error reading one of the 999 * index blocks, it will a negative error code. 1000 * 1001 * If start_hash is non-null, it will be filled in with the starting 1002 * hash of the next page. 1003 */ 1004 static int ext4_htree_next_block(struct inode *dir, __u32 hash, 1005 struct dx_frame *frame, 1006 struct dx_frame *frames, 1007 __u32 *start_hash) 1008 { 1009 struct dx_frame *p; 1010 struct buffer_head *bh; 1011 int num_frames = 0; 1012 __u32 bhash; 1013 1014 p = frame; 1015 /* 1016 * Find the next leaf page by incrementing the frame pointer. 1017 * If we run out of entries in the interior node, loop around and 1018 * increment pointer in the parent node. When we break out of 1019 * this loop, num_frames indicates the number of interior 1020 * nodes need to be read. 1021 */ 1022 while (1) { 1023 if (++(p->at) < p->entries + dx_get_count(p->entries)) 1024 break; 1025 if (p == frames) 1026 return 0; 1027 num_frames++; 1028 p--; 1029 } 1030 1031 /* 1032 * If the hash is 1, then continue only if the next page has a 1033 * continuation hash of any value. This is used for readdir 1034 * handling. Otherwise, check to see if the hash matches the 1035 * desired continuation hash. If it doesn't, return since 1036 * there's no point to read in the successive index pages. 1037 */ 1038 bhash = dx_get_hash(p->at); 1039 if (start_hash) 1040 *start_hash = bhash; 1041 if ((hash & 1) == 0) { 1042 if ((bhash & ~1) != hash) 1043 return 0; 1044 } 1045 /* 1046 * If the hash is HASH_NB_ALWAYS, we always go to the next 1047 * block so no check is necessary 1048 */ 1049 while (num_frames--) { 1050 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX); 1051 if (IS_ERR(bh)) 1052 return PTR_ERR(bh); 1053 p++; 1054 brelse(p->bh); 1055 p->bh = bh; 1056 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries; 1057 } 1058 return 1; 1059 } 1060 1061 1062 /* 1063 * This function fills a red-black tree with information from a 1064 * directory block. It returns the number directory entries loaded 1065 * into the tree. If there is an error it is returned in err. 1066 */ 1067 static int htree_dirblock_to_tree(struct file *dir_file, 1068 struct inode *dir, ext4_lblk_t block, 1069 struct dx_hash_info *hinfo, 1070 __u32 start_hash, __u32 start_minor_hash) 1071 { 1072 struct buffer_head *bh; 1073 struct ext4_dir_entry_2 *de, *top; 1074 int err = 0, count = 0; 1075 struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str; 1076 int csum = ext4_has_metadata_csum(dir->i_sb); 1077 1078 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n", 1079 (unsigned long)block)); 1080 bh = ext4_read_dirblock(dir, block, DIRENT_HTREE); 1081 if (IS_ERR(bh)) 1082 return PTR_ERR(bh); 1083 1084 de = (struct ext4_dir_entry_2 *) bh->b_data; 1085 /* csum entries are not larger in the casefolded encrypted case */ 1086 top = (struct ext4_dir_entry_2 *) ((char *) de + 1087 dir->i_sb->s_blocksize - 1088 ext4_dir_rec_len(0, 1089 csum ? NULL : dir)); 1090 /* Check if the directory is encrypted */ 1091 if (IS_ENCRYPTED(dir)) { 1092 err = fscrypt_prepare_readdir(dir); 1093 if (err < 0) { 1094 brelse(bh); 1095 return err; 1096 } 1097 err = fscrypt_fname_alloc_buffer(EXT4_NAME_LEN, 1098 &fname_crypto_str); 1099 if (err < 0) { 1100 brelse(bh); 1101 return err; 1102 } 1103 } 1104 1105 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) { 1106 if (ext4_check_dir_entry(dir, NULL, de, bh, 1107 bh->b_data, bh->b_size, 1108 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb)) 1109 + ((char *)de - bh->b_data))) { 1110 /* silently ignore the rest of the block */ 1111 break; 1112 } 1113 if (ext4_hash_in_dirent(dir)) { 1114 if (de->name_len && de->inode) { 1115 hinfo->hash = EXT4_DIRENT_HASH(de); 1116 hinfo->minor_hash = EXT4_DIRENT_MINOR_HASH(de); 1117 } else { 1118 hinfo->hash = 0; 1119 hinfo->minor_hash = 0; 1120 } 1121 } else { 1122 err = ext4fs_dirhash(dir, de->name, 1123 de->name_len, hinfo); 1124 if (err < 0) { 1125 count = err; 1126 goto errout; 1127 } 1128 } 1129 if ((hinfo->hash < start_hash) || 1130 ((hinfo->hash == start_hash) && 1131 (hinfo->minor_hash < start_minor_hash))) 1132 continue; 1133 if (de->inode == 0) 1134 continue; 1135 if (!IS_ENCRYPTED(dir)) { 1136 tmp_str.name = de->name; 1137 tmp_str.len = de->name_len; 1138 err = ext4_htree_store_dirent(dir_file, 1139 hinfo->hash, hinfo->minor_hash, de, 1140 &tmp_str); 1141 } else { 1142 int save_len = fname_crypto_str.len; 1143 struct fscrypt_str de_name = FSTR_INIT(de->name, 1144 de->name_len); 1145 1146 /* Directory is encrypted */ 1147 err = fscrypt_fname_disk_to_usr(dir, hinfo->hash, 1148 hinfo->minor_hash, &de_name, 1149 &fname_crypto_str); 1150 if (err) { 1151 count = err; 1152 goto errout; 1153 } 1154 err = ext4_htree_store_dirent(dir_file, 1155 hinfo->hash, hinfo->minor_hash, de, 1156 &fname_crypto_str); 1157 fname_crypto_str.len = save_len; 1158 } 1159 if (err != 0) { 1160 count = err; 1161 goto errout; 1162 } 1163 count++; 1164 } 1165 errout: 1166 brelse(bh); 1167 fscrypt_fname_free_buffer(&fname_crypto_str); 1168 return count; 1169 } 1170 1171 1172 /* 1173 * This function fills a red-black tree with information from a 1174 * directory. We start scanning the directory in hash order, starting 1175 * at start_hash and start_minor_hash. 1176 * 1177 * This function returns the number of entries inserted into the tree, 1178 * or a negative error code. 1179 */ 1180 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash, 1181 __u32 start_minor_hash, __u32 *next_hash) 1182 { 1183 struct dx_hash_info hinfo; 1184 struct ext4_dir_entry_2 *de; 1185 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 1186 struct inode *dir; 1187 ext4_lblk_t block; 1188 int count = 0; 1189 int ret, err; 1190 __u32 hashval; 1191 struct fscrypt_str tmp_str; 1192 1193 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n", 1194 start_hash, start_minor_hash)); 1195 dir = file_inode(dir_file); 1196 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) { 1197 if (ext4_hash_in_dirent(dir)) 1198 hinfo.hash_version = DX_HASH_SIPHASH; 1199 else 1200 hinfo.hash_version = 1201 EXT4_SB(dir->i_sb)->s_def_hash_version; 1202 if (hinfo.hash_version <= DX_HASH_TEA) 1203 hinfo.hash_version += 1204 EXT4_SB(dir->i_sb)->s_hash_unsigned; 1205 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; 1206 if (ext4_has_inline_data(dir)) { 1207 int has_inline_data = 1; 1208 count = ext4_inlinedir_to_tree(dir_file, dir, 0, 1209 &hinfo, start_hash, 1210 start_minor_hash, 1211 &has_inline_data); 1212 if (has_inline_data) { 1213 *next_hash = ~0; 1214 return count; 1215 } 1216 } 1217 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo, 1218 start_hash, start_minor_hash); 1219 *next_hash = ~0; 1220 return count; 1221 } 1222 hinfo.hash = start_hash; 1223 hinfo.minor_hash = 0; 1224 frame = dx_probe(NULL, dir, &hinfo, frames); 1225 if (IS_ERR(frame)) 1226 return PTR_ERR(frame); 1227 1228 /* Add '.' and '..' from the htree header */ 1229 if (!start_hash && !start_minor_hash) { 1230 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; 1231 tmp_str.name = de->name; 1232 tmp_str.len = de->name_len; 1233 err = ext4_htree_store_dirent(dir_file, 0, 0, 1234 de, &tmp_str); 1235 if (err != 0) 1236 goto errout; 1237 count++; 1238 } 1239 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) { 1240 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; 1241 de = ext4_next_entry(de, dir->i_sb->s_blocksize); 1242 tmp_str.name = de->name; 1243 tmp_str.len = de->name_len; 1244 err = ext4_htree_store_dirent(dir_file, 2, 0, 1245 de, &tmp_str); 1246 if (err != 0) 1247 goto errout; 1248 count++; 1249 } 1250 1251 while (1) { 1252 if (fatal_signal_pending(current)) { 1253 err = -ERESTARTSYS; 1254 goto errout; 1255 } 1256 cond_resched(); 1257 block = dx_get_block(frame->at); 1258 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo, 1259 start_hash, start_minor_hash); 1260 if (ret < 0) { 1261 err = ret; 1262 goto errout; 1263 } 1264 count += ret; 1265 hashval = ~0; 1266 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS, 1267 frame, frames, &hashval); 1268 *next_hash = hashval; 1269 if (ret < 0) { 1270 err = ret; 1271 goto errout; 1272 } 1273 /* 1274 * Stop if: (a) there are no more entries, or 1275 * (b) we have inserted at least one entry and the 1276 * next hash value is not a continuation 1277 */ 1278 if ((ret == 0) || 1279 (count && ((hashval & 1) == 0))) 1280 break; 1281 } 1282 dx_release(frames); 1283 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, " 1284 "next hash: %x\n", count, *next_hash)); 1285 return count; 1286 errout: 1287 dx_release(frames); 1288 return (err); 1289 } 1290 1291 static inline int search_dirblock(struct buffer_head *bh, 1292 struct inode *dir, 1293 struct ext4_filename *fname, 1294 unsigned int offset, 1295 struct ext4_dir_entry_2 **res_dir) 1296 { 1297 return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir, 1298 fname, offset, res_dir); 1299 } 1300 1301 /* 1302 * Directory block splitting, compacting 1303 */ 1304 1305 /* 1306 * Create map of hash values, offsets, and sizes, stored at end of block. 1307 * Returns number of entries mapped. 1308 */ 1309 static int dx_make_map(struct inode *dir, struct buffer_head *bh, 1310 struct dx_hash_info *hinfo, 1311 struct dx_map_entry *map_tail) 1312 { 1313 int count = 0; 1314 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)bh->b_data; 1315 unsigned int buflen = bh->b_size; 1316 char *base = bh->b_data; 1317 struct dx_hash_info h = *hinfo; 1318 1319 if (ext4_has_metadata_csum(dir->i_sb)) 1320 buflen -= sizeof(struct ext4_dir_entry_tail); 1321 1322 while ((char *) de < base + buflen) { 1323 if (ext4_check_dir_entry(dir, NULL, de, bh, base, buflen, 1324 ((char *)de) - base)) 1325 return -EFSCORRUPTED; 1326 if (de->name_len && de->inode) { 1327 if (ext4_hash_in_dirent(dir)) 1328 h.hash = EXT4_DIRENT_HASH(de); 1329 else { 1330 int err = ext4fs_dirhash(dir, de->name, 1331 de->name_len, &h); 1332 if (err < 0) 1333 return err; 1334 } 1335 map_tail--; 1336 map_tail->hash = h.hash; 1337 map_tail->offs = ((char *) de - base)>>2; 1338 map_tail->size = le16_to_cpu(de->rec_len); 1339 count++; 1340 cond_resched(); 1341 } 1342 de = ext4_next_entry(de, dir->i_sb->s_blocksize); 1343 } 1344 return count; 1345 } 1346 1347 /* Sort map by hash value */ 1348 static void dx_sort_map (struct dx_map_entry *map, unsigned count) 1349 { 1350 struct dx_map_entry *p, *q, *top = map + count - 1; 1351 int more; 1352 /* Combsort until bubble sort doesn't suck */ 1353 while (count > 2) { 1354 count = count*10/13; 1355 if (count - 9 < 2) /* 9, 10 -> 11 */ 1356 count = 11; 1357 for (p = top, q = p - count; q >= map; p--, q--) 1358 if (p->hash < q->hash) 1359 swap(*p, *q); 1360 } 1361 /* Garden variety bubble sort */ 1362 do { 1363 more = 0; 1364 q = top; 1365 while (q-- > map) { 1366 if (q[1].hash >= q[0].hash) 1367 continue; 1368 swap(*(q+1), *q); 1369 more = 1; 1370 } 1371 } while(more); 1372 } 1373 1374 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block) 1375 { 1376 struct dx_entry *entries = frame->entries; 1377 struct dx_entry *old = frame->at, *new = old + 1; 1378 int count = dx_get_count(entries); 1379 1380 ASSERT(count < dx_get_limit(entries)); 1381 ASSERT(old < entries + count); 1382 memmove(new + 1, new, (char *)(entries + count) - (char *)(new)); 1383 dx_set_hash(new, hash); 1384 dx_set_block(new, block); 1385 dx_set_count(entries, count + 1); 1386 } 1387 1388 #if IS_ENABLED(CONFIG_UNICODE) 1389 /* 1390 * Test whether a case-insensitive directory entry matches the filename 1391 * being searched for. If quick is set, assume the name being looked up 1392 * is already in the casefolded form. 1393 * 1394 * Returns: 0 if the directory entry matches, more than 0 if it 1395 * doesn't match or less than zero on error. 1396 */ 1397 static int ext4_ci_compare(const struct inode *parent, const struct qstr *name, 1398 u8 *de_name, size_t de_name_len, bool quick) 1399 { 1400 const struct super_block *sb = parent->i_sb; 1401 const struct unicode_map *um = sb->s_encoding; 1402 struct fscrypt_str decrypted_name = FSTR_INIT(NULL, de_name_len); 1403 struct qstr entry = QSTR_INIT(de_name, de_name_len); 1404 int ret; 1405 1406 if (IS_ENCRYPTED(parent)) { 1407 const struct fscrypt_str encrypted_name = 1408 FSTR_INIT(de_name, de_name_len); 1409 1410 decrypted_name.name = kmalloc(de_name_len, GFP_KERNEL); 1411 if (!decrypted_name.name) 1412 return -ENOMEM; 1413 ret = fscrypt_fname_disk_to_usr(parent, 0, 0, &encrypted_name, 1414 &decrypted_name); 1415 if (ret < 0) 1416 goto out; 1417 entry.name = decrypted_name.name; 1418 entry.len = decrypted_name.len; 1419 } 1420 1421 if (quick) 1422 ret = utf8_strncasecmp_folded(um, name, &entry); 1423 else 1424 ret = utf8_strncasecmp(um, name, &entry); 1425 if (ret < 0) { 1426 /* Handle invalid character sequence as either an error 1427 * or as an opaque byte sequence. 1428 */ 1429 if (sb_has_strict_encoding(sb)) 1430 ret = -EINVAL; 1431 else if (name->len != entry.len) 1432 ret = 1; 1433 else 1434 ret = !!memcmp(name->name, entry.name, entry.len); 1435 } 1436 out: 1437 kfree(decrypted_name.name); 1438 return ret; 1439 } 1440 1441 int ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname, 1442 struct ext4_filename *name) 1443 { 1444 struct fscrypt_str *cf_name = &name->cf_name; 1445 struct dx_hash_info *hinfo = &name->hinfo; 1446 int len; 1447 1448 if (!IS_CASEFOLDED(dir) || !dir->i_sb->s_encoding || 1449 (IS_ENCRYPTED(dir) && !fscrypt_has_encryption_key(dir))) { 1450 cf_name->name = NULL; 1451 return 0; 1452 } 1453 1454 cf_name->name = kmalloc(EXT4_NAME_LEN, GFP_NOFS); 1455 if (!cf_name->name) 1456 return -ENOMEM; 1457 1458 len = utf8_casefold(dir->i_sb->s_encoding, 1459 iname, cf_name->name, 1460 EXT4_NAME_LEN); 1461 if (len <= 0) { 1462 kfree(cf_name->name); 1463 cf_name->name = NULL; 1464 } 1465 cf_name->len = (unsigned) len; 1466 if (!IS_ENCRYPTED(dir)) 1467 return 0; 1468 1469 hinfo->hash_version = DX_HASH_SIPHASH; 1470 hinfo->seed = NULL; 1471 if (cf_name->name) 1472 return ext4fs_dirhash(dir, cf_name->name, cf_name->len, hinfo); 1473 else 1474 return ext4fs_dirhash(dir, iname->name, iname->len, hinfo); 1475 } 1476 #endif 1477 1478 /* 1479 * Test whether a directory entry matches the filename being searched for. 1480 * 1481 * Return: %true if the directory entry matches, otherwise %false. 1482 */ 1483 static bool ext4_match(struct inode *parent, 1484 const struct ext4_filename *fname, 1485 struct ext4_dir_entry_2 *de) 1486 { 1487 struct fscrypt_name f; 1488 1489 if (!de->inode) 1490 return false; 1491 1492 f.usr_fname = fname->usr_fname; 1493 f.disk_name = fname->disk_name; 1494 #ifdef CONFIG_FS_ENCRYPTION 1495 f.crypto_buf = fname->crypto_buf; 1496 #endif 1497 1498 #if IS_ENABLED(CONFIG_UNICODE) 1499 if (parent->i_sb->s_encoding && IS_CASEFOLDED(parent) && 1500 (!IS_ENCRYPTED(parent) || fscrypt_has_encryption_key(parent))) { 1501 if (fname->cf_name.name) { 1502 struct qstr cf = {.name = fname->cf_name.name, 1503 .len = fname->cf_name.len}; 1504 if (IS_ENCRYPTED(parent)) { 1505 if (fname->hinfo.hash != EXT4_DIRENT_HASH(de) || 1506 fname->hinfo.minor_hash != 1507 EXT4_DIRENT_MINOR_HASH(de)) { 1508 1509 return false; 1510 } 1511 } 1512 return !ext4_ci_compare(parent, &cf, de->name, 1513 de->name_len, true); 1514 } 1515 return !ext4_ci_compare(parent, fname->usr_fname, de->name, 1516 de->name_len, false); 1517 } 1518 #endif 1519 1520 return fscrypt_match_name(&f, de->name, de->name_len); 1521 } 1522 1523 /* 1524 * Returns 0 if not found, -1 on failure, and 1 on success 1525 */ 1526 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size, 1527 struct inode *dir, struct ext4_filename *fname, 1528 unsigned int offset, struct ext4_dir_entry_2 **res_dir) 1529 { 1530 struct ext4_dir_entry_2 * de; 1531 char * dlimit; 1532 int de_len; 1533 1534 de = (struct ext4_dir_entry_2 *)search_buf; 1535 dlimit = search_buf + buf_size; 1536 while ((char *) de < dlimit - EXT4_BASE_DIR_LEN) { 1537 /* this code is executed quadratically often */ 1538 /* do minimal checking `by hand' */ 1539 if (de->name + de->name_len <= dlimit && 1540 ext4_match(dir, fname, de)) { 1541 /* found a match - just to be sure, do 1542 * a full check */ 1543 if (ext4_check_dir_entry(dir, NULL, de, bh, search_buf, 1544 buf_size, offset)) 1545 return -1; 1546 *res_dir = de; 1547 return 1; 1548 } 1549 /* prevent looping on a bad block */ 1550 de_len = ext4_rec_len_from_disk(de->rec_len, 1551 dir->i_sb->s_blocksize); 1552 if (de_len <= 0) 1553 return -1; 1554 offset += de_len; 1555 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len); 1556 } 1557 return 0; 1558 } 1559 1560 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block, 1561 struct ext4_dir_entry *de) 1562 { 1563 struct super_block *sb = dir->i_sb; 1564 1565 if (!is_dx(dir)) 1566 return 0; 1567 if (block == 0) 1568 return 1; 1569 if (de->inode == 0 && 1570 ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) == 1571 sb->s_blocksize) 1572 return 1; 1573 return 0; 1574 } 1575 1576 /* 1577 * __ext4_find_entry() 1578 * 1579 * finds an entry in the specified directory with the wanted name. It 1580 * returns the cache buffer in which the entry was found, and the entry 1581 * itself (as a parameter - res_dir). It does NOT read the inode of the 1582 * entry - you'll have to do that yourself if you want to. 1583 * 1584 * The returned buffer_head has ->b_count elevated. The caller is expected 1585 * to brelse() it when appropriate. 1586 */ 1587 static struct buffer_head *__ext4_find_entry(struct inode *dir, 1588 struct ext4_filename *fname, 1589 struct ext4_dir_entry_2 **res_dir, 1590 int *inlined) 1591 { 1592 struct super_block *sb; 1593 struct buffer_head *bh_use[NAMEI_RA_SIZE]; 1594 struct buffer_head *bh, *ret = NULL; 1595 ext4_lblk_t start, block; 1596 const u8 *name = fname->usr_fname->name; 1597 size_t ra_max = 0; /* Number of bh's in the readahead 1598 buffer, bh_use[] */ 1599 size_t ra_ptr = 0; /* Current index into readahead 1600 buffer */ 1601 ext4_lblk_t nblocks; 1602 int i, namelen, retval; 1603 1604 *res_dir = NULL; 1605 sb = dir->i_sb; 1606 namelen = fname->usr_fname->len; 1607 if (namelen > EXT4_NAME_LEN) 1608 return NULL; 1609 1610 if (ext4_has_inline_data(dir)) { 1611 int has_inline_data = 1; 1612 ret = ext4_find_inline_entry(dir, fname, res_dir, 1613 &has_inline_data); 1614 if (inlined) 1615 *inlined = has_inline_data; 1616 if (has_inline_data) 1617 goto cleanup_and_exit; 1618 } 1619 1620 if ((namelen <= 2) && (name[0] == '.') && 1621 (name[1] == '.' || name[1] == '\0')) { 1622 /* 1623 * "." or ".." will only be in the first block 1624 * NFS may look up ".."; "." should be handled by the VFS 1625 */ 1626 block = start = 0; 1627 nblocks = 1; 1628 goto restart; 1629 } 1630 if (is_dx(dir)) { 1631 ret = ext4_dx_find_entry(dir, fname, res_dir); 1632 /* 1633 * On success, or if the error was file not found, 1634 * return. Otherwise, fall back to doing a search the 1635 * old fashioned way. 1636 */ 1637 if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR) 1638 goto cleanup_and_exit; 1639 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, " 1640 "falling back\n")); 1641 ret = NULL; 1642 } 1643 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); 1644 if (!nblocks) { 1645 ret = NULL; 1646 goto cleanup_and_exit; 1647 } 1648 start = EXT4_I(dir)->i_dir_start_lookup; 1649 if (start >= nblocks) 1650 start = 0; 1651 block = start; 1652 restart: 1653 do { 1654 /* 1655 * We deal with the read-ahead logic here. 1656 */ 1657 cond_resched(); 1658 if (ra_ptr >= ra_max) { 1659 /* Refill the readahead buffer */ 1660 ra_ptr = 0; 1661 if (block < start) 1662 ra_max = start - block; 1663 else 1664 ra_max = nblocks - block; 1665 ra_max = min(ra_max, ARRAY_SIZE(bh_use)); 1666 retval = ext4_bread_batch(dir, block, ra_max, 1667 false /* wait */, bh_use); 1668 if (retval) { 1669 ret = ERR_PTR(retval); 1670 ra_max = 0; 1671 goto cleanup_and_exit; 1672 } 1673 } 1674 if ((bh = bh_use[ra_ptr++]) == NULL) 1675 goto next; 1676 wait_on_buffer(bh); 1677 if (!buffer_uptodate(bh)) { 1678 EXT4_ERROR_INODE_ERR(dir, EIO, 1679 "reading directory lblock %lu", 1680 (unsigned long) block); 1681 brelse(bh); 1682 ret = ERR_PTR(-EIO); 1683 goto cleanup_and_exit; 1684 } 1685 if (!buffer_verified(bh) && 1686 !is_dx_internal_node(dir, block, 1687 (struct ext4_dir_entry *)bh->b_data) && 1688 !ext4_dirblock_csum_verify(dir, bh)) { 1689 EXT4_ERROR_INODE_ERR(dir, EFSBADCRC, 1690 "checksumming directory " 1691 "block %lu", (unsigned long)block); 1692 brelse(bh); 1693 ret = ERR_PTR(-EFSBADCRC); 1694 goto cleanup_and_exit; 1695 } 1696 set_buffer_verified(bh); 1697 i = search_dirblock(bh, dir, fname, 1698 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir); 1699 if (i == 1) { 1700 EXT4_I(dir)->i_dir_start_lookup = block; 1701 ret = bh; 1702 goto cleanup_and_exit; 1703 } else { 1704 brelse(bh); 1705 if (i < 0) 1706 goto cleanup_and_exit; 1707 } 1708 next: 1709 if (++block >= nblocks) 1710 block = 0; 1711 } while (block != start); 1712 1713 /* 1714 * If the directory has grown while we were searching, then 1715 * search the last part of the directory before giving up. 1716 */ 1717 block = nblocks; 1718 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); 1719 if (block < nblocks) { 1720 start = 0; 1721 goto restart; 1722 } 1723 1724 cleanup_and_exit: 1725 /* Clean up the read-ahead blocks */ 1726 for (; ra_ptr < ra_max; ra_ptr++) 1727 brelse(bh_use[ra_ptr]); 1728 return ret; 1729 } 1730 1731 static struct buffer_head *ext4_find_entry(struct inode *dir, 1732 const struct qstr *d_name, 1733 struct ext4_dir_entry_2 **res_dir, 1734 int *inlined) 1735 { 1736 int err; 1737 struct ext4_filename fname; 1738 struct buffer_head *bh; 1739 1740 err = ext4_fname_setup_filename(dir, d_name, 1, &fname); 1741 if (err == -ENOENT) 1742 return NULL; 1743 if (err) 1744 return ERR_PTR(err); 1745 1746 bh = __ext4_find_entry(dir, &fname, res_dir, inlined); 1747 1748 ext4_fname_free_filename(&fname); 1749 return bh; 1750 } 1751 1752 static struct buffer_head *ext4_lookup_entry(struct inode *dir, 1753 struct dentry *dentry, 1754 struct ext4_dir_entry_2 **res_dir) 1755 { 1756 int err; 1757 struct ext4_filename fname; 1758 struct buffer_head *bh; 1759 1760 err = ext4_fname_prepare_lookup(dir, dentry, &fname); 1761 generic_set_encrypted_ci_d_ops(dentry); 1762 if (err == -ENOENT) 1763 return NULL; 1764 if (err) 1765 return ERR_PTR(err); 1766 1767 bh = __ext4_find_entry(dir, &fname, res_dir, NULL); 1768 1769 ext4_fname_free_filename(&fname); 1770 return bh; 1771 } 1772 1773 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, 1774 struct ext4_filename *fname, 1775 struct ext4_dir_entry_2 **res_dir) 1776 { 1777 struct super_block * sb = dir->i_sb; 1778 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 1779 struct buffer_head *bh; 1780 ext4_lblk_t block; 1781 int retval; 1782 1783 #ifdef CONFIG_FS_ENCRYPTION 1784 *res_dir = NULL; 1785 #endif 1786 frame = dx_probe(fname, dir, NULL, frames); 1787 if (IS_ERR(frame)) 1788 return (struct buffer_head *) frame; 1789 do { 1790 block = dx_get_block(frame->at); 1791 bh = ext4_read_dirblock(dir, block, DIRENT_HTREE); 1792 if (IS_ERR(bh)) 1793 goto errout; 1794 1795 retval = search_dirblock(bh, dir, fname, 1796 block << EXT4_BLOCK_SIZE_BITS(sb), 1797 res_dir); 1798 if (retval == 1) 1799 goto success; 1800 brelse(bh); 1801 if (retval == -1) { 1802 bh = ERR_PTR(ERR_BAD_DX_DIR); 1803 goto errout; 1804 } 1805 1806 /* Check to see if we should continue to search */ 1807 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame, 1808 frames, NULL); 1809 if (retval < 0) { 1810 ext4_warning_inode(dir, 1811 "error %d reading directory index block", 1812 retval); 1813 bh = ERR_PTR(retval); 1814 goto errout; 1815 } 1816 } while (retval == 1); 1817 1818 bh = NULL; 1819 errout: 1820 dxtrace(printk(KERN_DEBUG "%s not found\n", fname->usr_fname->name)); 1821 success: 1822 dx_release(frames); 1823 return bh; 1824 } 1825 1826 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 1827 { 1828 struct inode *inode; 1829 struct ext4_dir_entry_2 *de; 1830 struct buffer_head *bh; 1831 1832 if (dentry->d_name.len > EXT4_NAME_LEN) 1833 return ERR_PTR(-ENAMETOOLONG); 1834 1835 bh = ext4_lookup_entry(dir, dentry, &de); 1836 if (IS_ERR(bh)) 1837 return ERR_CAST(bh); 1838 inode = NULL; 1839 if (bh) { 1840 __u32 ino = le32_to_cpu(de->inode); 1841 brelse(bh); 1842 if (!ext4_valid_inum(dir->i_sb, ino)) { 1843 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino); 1844 return ERR_PTR(-EFSCORRUPTED); 1845 } 1846 if (unlikely(ino == dir->i_ino)) { 1847 EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir", 1848 dentry); 1849 return ERR_PTR(-EFSCORRUPTED); 1850 } 1851 inode = ext4_iget(dir->i_sb, ino, EXT4_IGET_NORMAL); 1852 if (inode == ERR_PTR(-ESTALE)) { 1853 EXT4_ERROR_INODE(dir, 1854 "deleted inode referenced: %u", 1855 ino); 1856 return ERR_PTR(-EFSCORRUPTED); 1857 } 1858 if (!IS_ERR(inode) && IS_ENCRYPTED(dir) && 1859 (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) && 1860 !fscrypt_has_permitted_context(dir, inode)) { 1861 ext4_warning(inode->i_sb, 1862 "Inconsistent encryption contexts: %lu/%lu", 1863 dir->i_ino, inode->i_ino); 1864 iput(inode); 1865 return ERR_PTR(-EPERM); 1866 } 1867 } 1868 1869 #if IS_ENABLED(CONFIG_UNICODE) 1870 if (!inode && IS_CASEFOLDED(dir)) { 1871 /* Eventually we want to call d_add_ci(dentry, NULL) 1872 * for negative dentries in the encoding case as 1873 * well. For now, prevent the negative dentry 1874 * from being cached. 1875 */ 1876 return NULL; 1877 } 1878 #endif 1879 return d_splice_alias(inode, dentry); 1880 } 1881 1882 1883 struct dentry *ext4_get_parent(struct dentry *child) 1884 { 1885 __u32 ino; 1886 struct ext4_dir_entry_2 * de; 1887 struct buffer_head *bh; 1888 1889 bh = ext4_find_entry(d_inode(child), &dotdot_name, &de, NULL); 1890 if (IS_ERR(bh)) 1891 return ERR_CAST(bh); 1892 if (!bh) 1893 return ERR_PTR(-ENOENT); 1894 ino = le32_to_cpu(de->inode); 1895 brelse(bh); 1896 1897 if (!ext4_valid_inum(child->d_sb, ino)) { 1898 EXT4_ERROR_INODE(d_inode(child), 1899 "bad parent inode number: %u", ino); 1900 return ERR_PTR(-EFSCORRUPTED); 1901 } 1902 1903 return d_obtain_alias(ext4_iget(child->d_sb, ino, EXT4_IGET_NORMAL)); 1904 } 1905 1906 /* 1907 * Move count entries from end of map between two memory locations. 1908 * Returns pointer to last entry moved. 1909 */ 1910 static struct ext4_dir_entry_2 * 1911 dx_move_dirents(struct inode *dir, char *from, char *to, 1912 struct dx_map_entry *map, int count, 1913 unsigned blocksize) 1914 { 1915 unsigned rec_len = 0; 1916 1917 while (count--) { 1918 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) 1919 (from + (map->offs<<2)); 1920 rec_len = ext4_dir_rec_len(de->name_len, dir); 1921 1922 memcpy (to, de, rec_len); 1923 ((struct ext4_dir_entry_2 *) to)->rec_len = 1924 ext4_rec_len_to_disk(rec_len, blocksize); 1925 1926 /* wipe dir_entry excluding the rec_len field */ 1927 de->inode = 0; 1928 memset(&de->name_len, 0, ext4_rec_len_from_disk(de->rec_len, 1929 blocksize) - 1930 offsetof(struct ext4_dir_entry_2, 1931 name_len)); 1932 1933 map++; 1934 to += rec_len; 1935 } 1936 return (struct ext4_dir_entry_2 *) (to - rec_len); 1937 } 1938 1939 /* 1940 * Compact each dir entry in the range to the minimal rec_len. 1941 * Returns pointer to last entry in range. 1942 */ 1943 static struct ext4_dir_entry_2 *dx_pack_dirents(struct inode *dir, char *base, 1944 unsigned int blocksize) 1945 { 1946 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base; 1947 unsigned rec_len = 0; 1948 1949 prev = to = de; 1950 while ((char*)de < base + blocksize) { 1951 next = ext4_next_entry(de, blocksize); 1952 if (de->inode && de->name_len) { 1953 rec_len = ext4_dir_rec_len(de->name_len, dir); 1954 if (de > to) 1955 memmove(to, de, rec_len); 1956 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize); 1957 prev = to; 1958 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len); 1959 } 1960 de = next; 1961 } 1962 return prev; 1963 } 1964 1965 /* 1966 * Split a full leaf block to make room for a new dir entry. 1967 * Allocate a new block, and move entries so that they are approx. equally full. 1968 * Returns pointer to de in block into which the new entry will be inserted. 1969 */ 1970 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir, 1971 struct buffer_head **bh,struct dx_frame *frame, 1972 struct dx_hash_info *hinfo) 1973 { 1974 unsigned blocksize = dir->i_sb->s_blocksize; 1975 unsigned continued; 1976 int count; 1977 struct buffer_head *bh2; 1978 ext4_lblk_t newblock; 1979 u32 hash2; 1980 struct dx_map_entry *map; 1981 char *data1 = (*bh)->b_data, *data2; 1982 unsigned split, move, size; 1983 struct ext4_dir_entry_2 *de = NULL, *de2; 1984 int csum_size = 0; 1985 int err = 0, i; 1986 1987 if (ext4_has_metadata_csum(dir->i_sb)) 1988 csum_size = sizeof(struct ext4_dir_entry_tail); 1989 1990 bh2 = ext4_append(handle, dir, &newblock); 1991 if (IS_ERR(bh2)) { 1992 brelse(*bh); 1993 *bh = NULL; 1994 return (struct ext4_dir_entry_2 *) bh2; 1995 } 1996 1997 BUFFER_TRACE(*bh, "get_write_access"); 1998 err = ext4_journal_get_write_access(handle, dir->i_sb, *bh, 1999 EXT4_JTR_NONE); 2000 if (err) 2001 goto journal_error; 2002 2003 BUFFER_TRACE(frame->bh, "get_write_access"); 2004 err = ext4_journal_get_write_access(handle, dir->i_sb, frame->bh, 2005 EXT4_JTR_NONE); 2006 if (err) 2007 goto journal_error; 2008 2009 data2 = bh2->b_data; 2010 2011 /* create map in the end of data2 block */ 2012 map = (struct dx_map_entry *) (data2 + blocksize); 2013 count = dx_make_map(dir, *bh, hinfo, map); 2014 if (count < 0) { 2015 err = count; 2016 goto journal_error; 2017 } 2018 map -= count; 2019 dx_sort_map(map, count); 2020 /* Ensure that neither split block is over half full */ 2021 size = 0; 2022 move = 0; 2023 for (i = count-1; i >= 0; i--) { 2024 /* is more than half of this entry in 2nd half of the block? */ 2025 if (size + map[i].size/2 > blocksize/2) 2026 break; 2027 size += map[i].size; 2028 move++; 2029 } 2030 /* 2031 * map index at which we will split 2032 * 2033 * If the sum of active entries didn't exceed half the block size, just 2034 * split it in half by count; each resulting block will have at least 2035 * half the space free. 2036 */ 2037 if (i > 0) 2038 split = count - move; 2039 else 2040 split = count/2; 2041 2042 hash2 = map[split].hash; 2043 continued = hash2 == map[split - 1].hash; 2044 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n", 2045 (unsigned long)dx_get_block(frame->at), 2046 hash2, split, count-split)); 2047 2048 /* Fancy dance to stay within two buffers */ 2049 de2 = dx_move_dirents(dir, data1, data2, map + split, count - split, 2050 blocksize); 2051 de = dx_pack_dirents(dir, data1, blocksize); 2052 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) - 2053 (char *) de, 2054 blocksize); 2055 de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) - 2056 (char *) de2, 2057 blocksize); 2058 if (csum_size) { 2059 ext4_initialize_dirent_tail(*bh, blocksize); 2060 ext4_initialize_dirent_tail(bh2, blocksize); 2061 } 2062 2063 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1, 2064 blocksize, 1)); 2065 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2, 2066 blocksize, 1)); 2067 2068 /* Which block gets the new entry? */ 2069 if (hinfo->hash >= hash2) { 2070 swap(*bh, bh2); 2071 de = de2; 2072 } 2073 dx_insert_block(frame, hash2 + continued, newblock); 2074 err = ext4_handle_dirty_dirblock(handle, dir, bh2); 2075 if (err) 2076 goto journal_error; 2077 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 2078 if (err) 2079 goto journal_error; 2080 brelse(bh2); 2081 dxtrace(dx_show_index("frame", frame->entries)); 2082 return de; 2083 2084 journal_error: 2085 brelse(*bh); 2086 brelse(bh2); 2087 *bh = NULL; 2088 ext4_std_error(dir->i_sb, err); 2089 return ERR_PTR(err); 2090 } 2091 2092 int ext4_find_dest_de(struct inode *dir, struct inode *inode, 2093 struct buffer_head *bh, 2094 void *buf, int buf_size, 2095 struct ext4_filename *fname, 2096 struct ext4_dir_entry_2 **dest_de) 2097 { 2098 struct ext4_dir_entry_2 *de; 2099 unsigned short reclen = ext4_dir_rec_len(fname_len(fname), dir); 2100 int nlen, rlen; 2101 unsigned int offset = 0; 2102 char *top; 2103 2104 de = buf; 2105 top = buf + buf_size - reclen; 2106 while ((char *) de <= top) { 2107 if (ext4_check_dir_entry(dir, NULL, de, bh, 2108 buf, buf_size, offset)) 2109 return -EFSCORRUPTED; 2110 if (ext4_match(dir, fname, de)) 2111 return -EEXIST; 2112 nlen = ext4_dir_rec_len(de->name_len, dir); 2113 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 2114 if ((de->inode ? rlen - nlen : rlen) >= reclen) 2115 break; 2116 de = (struct ext4_dir_entry_2 *)((char *)de + rlen); 2117 offset += rlen; 2118 } 2119 if ((char *) de > top) 2120 return -ENOSPC; 2121 2122 *dest_de = de; 2123 return 0; 2124 } 2125 2126 void ext4_insert_dentry(struct inode *dir, 2127 struct inode *inode, 2128 struct ext4_dir_entry_2 *de, 2129 int buf_size, 2130 struct ext4_filename *fname) 2131 { 2132 2133 int nlen, rlen; 2134 2135 nlen = ext4_dir_rec_len(de->name_len, dir); 2136 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 2137 if (de->inode) { 2138 struct ext4_dir_entry_2 *de1 = 2139 (struct ext4_dir_entry_2 *)((char *)de + nlen); 2140 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size); 2141 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size); 2142 de = de1; 2143 } 2144 de->file_type = EXT4_FT_UNKNOWN; 2145 de->inode = cpu_to_le32(inode->i_ino); 2146 ext4_set_de_type(inode->i_sb, de, inode->i_mode); 2147 de->name_len = fname_len(fname); 2148 memcpy(de->name, fname_name(fname), fname_len(fname)); 2149 if (ext4_hash_in_dirent(dir)) { 2150 struct dx_hash_info *hinfo = &fname->hinfo; 2151 2152 EXT4_DIRENT_HASHES(de)->hash = cpu_to_le32(hinfo->hash); 2153 EXT4_DIRENT_HASHES(de)->minor_hash = 2154 cpu_to_le32(hinfo->minor_hash); 2155 } 2156 } 2157 2158 /* 2159 * Add a new entry into a directory (leaf) block. If de is non-NULL, 2160 * it points to a directory entry which is guaranteed to be large 2161 * enough for new directory entry. If de is NULL, then 2162 * add_dirent_to_buf will attempt search the directory block for 2163 * space. It will return -ENOSPC if no space is available, and -EIO 2164 * and -EEXIST if directory entry already exists. 2165 */ 2166 static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname, 2167 struct inode *dir, 2168 struct inode *inode, struct ext4_dir_entry_2 *de, 2169 struct buffer_head *bh) 2170 { 2171 unsigned int blocksize = dir->i_sb->s_blocksize; 2172 int csum_size = 0; 2173 int err, err2; 2174 2175 if (ext4_has_metadata_csum(inode->i_sb)) 2176 csum_size = sizeof(struct ext4_dir_entry_tail); 2177 2178 if (!de) { 2179 err = ext4_find_dest_de(dir, inode, bh, bh->b_data, 2180 blocksize - csum_size, fname, &de); 2181 if (err) 2182 return err; 2183 } 2184 BUFFER_TRACE(bh, "get_write_access"); 2185 err = ext4_journal_get_write_access(handle, dir->i_sb, bh, 2186 EXT4_JTR_NONE); 2187 if (err) { 2188 ext4_std_error(dir->i_sb, err); 2189 return err; 2190 } 2191 2192 /* By now the buffer is marked for journaling */ 2193 ext4_insert_dentry(dir, inode, de, blocksize, fname); 2194 2195 /* 2196 * XXX shouldn't update any times until successful 2197 * completion of syscall, but too many callers depend 2198 * on this. 2199 * 2200 * XXX similarly, too many callers depend on 2201 * ext4_new_inode() setting the times, but error 2202 * recovery deletes the inode, so the worst that can 2203 * happen is that the times are slightly out of date 2204 * and/or different from the directory change time. 2205 */ 2206 dir->i_mtime = dir->i_ctime = current_time(dir); 2207 ext4_update_dx_flag(dir); 2208 inode_inc_iversion(dir); 2209 err2 = ext4_mark_inode_dirty(handle, dir); 2210 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); 2211 err = ext4_handle_dirty_dirblock(handle, dir, bh); 2212 if (err) 2213 ext4_std_error(dir->i_sb, err); 2214 return err ? err : err2; 2215 } 2216 2217 /* 2218 * This converts a one block unindexed directory to a 3 block indexed 2219 * directory, and adds the dentry to the indexed directory. 2220 */ 2221 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname, 2222 struct inode *dir, 2223 struct inode *inode, struct buffer_head *bh) 2224 { 2225 struct buffer_head *bh2; 2226 struct dx_root *root; 2227 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 2228 struct dx_entry *entries; 2229 struct ext4_dir_entry_2 *de, *de2; 2230 char *data2, *top; 2231 unsigned len; 2232 int retval; 2233 unsigned blocksize; 2234 ext4_lblk_t block; 2235 struct fake_dirent *fde; 2236 int csum_size = 0; 2237 2238 if (ext4_has_metadata_csum(inode->i_sb)) 2239 csum_size = sizeof(struct ext4_dir_entry_tail); 2240 2241 blocksize = dir->i_sb->s_blocksize; 2242 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino)); 2243 BUFFER_TRACE(bh, "get_write_access"); 2244 retval = ext4_journal_get_write_access(handle, dir->i_sb, bh, 2245 EXT4_JTR_NONE); 2246 if (retval) { 2247 ext4_std_error(dir->i_sb, retval); 2248 brelse(bh); 2249 return retval; 2250 } 2251 root = (struct dx_root *) bh->b_data; 2252 2253 /* The 0th block becomes the root, move the dirents out */ 2254 fde = &root->dotdot; 2255 de = (struct ext4_dir_entry_2 *)((char *)fde + 2256 ext4_rec_len_from_disk(fde->rec_len, blocksize)); 2257 if ((char *) de >= (((char *) root) + blocksize)) { 2258 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'"); 2259 brelse(bh); 2260 return -EFSCORRUPTED; 2261 } 2262 len = ((char *) root) + (blocksize - csum_size) - (char *) de; 2263 2264 /* Allocate new block for the 0th block's dirents */ 2265 bh2 = ext4_append(handle, dir, &block); 2266 if (IS_ERR(bh2)) { 2267 brelse(bh); 2268 return PTR_ERR(bh2); 2269 } 2270 ext4_set_inode_flag(dir, EXT4_INODE_INDEX); 2271 data2 = bh2->b_data; 2272 2273 memcpy(data2, de, len); 2274 memset(de, 0, len); /* wipe old data */ 2275 de = (struct ext4_dir_entry_2 *) data2; 2276 top = data2 + len; 2277 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top) { 2278 if (ext4_check_dir_entry(dir, NULL, de, bh2, data2, len, 2279 (data2 + (blocksize - csum_size) - 2280 (char *) de))) { 2281 brelse(bh2); 2282 brelse(bh); 2283 return -EFSCORRUPTED; 2284 } 2285 de = de2; 2286 } 2287 de->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) - 2288 (char *) de, blocksize); 2289 2290 if (csum_size) 2291 ext4_initialize_dirent_tail(bh2, blocksize); 2292 2293 /* Initialize the root; the dot dirents already exist */ 2294 de = (struct ext4_dir_entry_2 *) (&root->dotdot); 2295 de->rec_len = ext4_rec_len_to_disk( 2296 blocksize - ext4_dir_rec_len(2, NULL), blocksize); 2297 memset (&root->info, 0, sizeof(root->info)); 2298 root->info.info_length = sizeof(root->info); 2299 if (ext4_hash_in_dirent(dir)) 2300 root->info.hash_version = DX_HASH_SIPHASH; 2301 else 2302 root->info.hash_version = 2303 EXT4_SB(dir->i_sb)->s_def_hash_version; 2304 2305 entries = root->entries; 2306 dx_set_block(entries, 1); 2307 dx_set_count(entries, 1); 2308 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info))); 2309 2310 /* Initialize as for dx_probe */ 2311 fname->hinfo.hash_version = root->info.hash_version; 2312 if (fname->hinfo.hash_version <= DX_HASH_TEA) 2313 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; 2314 fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; 2315 2316 /* casefolded encrypted hashes are computed on fname setup */ 2317 if (!ext4_hash_in_dirent(dir)) { 2318 int err = ext4fs_dirhash(dir, fname_name(fname), 2319 fname_len(fname), &fname->hinfo); 2320 if (err < 0) { 2321 brelse(bh2); 2322 brelse(bh); 2323 return err; 2324 } 2325 } 2326 memset(frames, 0, sizeof(frames)); 2327 frame = frames; 2328 frame->entries = entries; 2329 frame->at = entries; 2330 frame->bh = bh; 2331 2332 retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 2333 if (retval) 2334 goto out_frames; 2335 retval = ext4_handle_dirty_dirblock(handle, dir, bh2); 2336 if (retval) 2337 goto out_frames; 2338 2339 de = do_split(handle,dir, &bh2, frame, &fname->hinfo); 2340 if (IS_ERR(de)) { 2341 retval = PTR_ERR(de); 2342 goto out_frames; 2343 } 2344 2345 retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2); 2346 out_frames: 2347 /* 2348 * Even if the block split failed, we have to properly write 2349 * out all the changes we did so far. Otherwise we can end up 2350 * with corrupted filesystem. 2351 */ 2352 if (retval) 2353 ext4_mark_inode_dirty(handle, dir); 2354 dx_release(frames); 2355 brelse(bh2); 2356 return retval; 2357 } 2358 2359 /* 2360 * ext4_add_entry() 2361 * 2362 * adds a file entry to the specified directory, using the same 2363 * semantics as ext4_find_entry(). It returns NULL if it failed. 2364 * 2365 * NOTE!! The inode part of 'de' is left at 0 - which means you 2366 * may not sleep between calling this and putting something into 2367 * the entry, as someone else might have used it while you slept. 2368 */ 2369 static int ext4_add_entry(handle_t *handle, struct dentry *dentry, 2370 struct inode *inode) 2371 { 2372 struct inode *dir = d_inode(dentry->d_parent); 2373 struct buffer_head *bh = NULL; 2374 struct ext4_dir_entry_2 *de; 2375 struct super_block *sb; 2376 struct ext4_filename fname; 2377 int retval; 2378 int dx_fallback=0; 2379 unsigned blocksize; 2380 ext4_lblk_t block, blocks; 2381 int csum_size = 0; 2382 2383 if (ext4_has_metadata_csum(inode->i_sb)) 2384 csum_size = sizeof(struct ext4_dir_entry_tail); 2385 2386 sb = dir->i_sb; 2387 blocksize = sb->s_blocksize; 2388 if (!dentry->d_name.len) 2389 return -EINVAL; 2390 2391 if (fscrypt_is_nokey_name(dentry)) 2392 return -ENOKEY; 2393 2394 #if IS_ENABLED(CONFIG_UNICODE) 2395 if (sb_has_strict_encoding(sb) && IS_CASEFOLDED(dir) && 2396 sb->s_encoding && utf8_validate(sb->s_encoding, &dentry->d_name)) 2397 return -EINVAL; 2398 #endif 2399 2400 retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname); 2401 if (retval) 2402 return retval; 2403 2404 if (ext4_has_inline_data(dir)) { 2405 retval = ext4_try_add_inline_entry(handle, &fname, dir, inode); 2406 if (retval < 0) 2407 goto out; 2408 if (retval == 1) { 2409 retval = 0; 2410 goto out; 2411 } 2412 } 2413 2414 if (is_dx(dir)) { 2415 retval = ext4_dx_add_entry(handle, &fname, dir, inode); 2416 if (!retval || (retval != ERR_BAD_DX_DIR)) 2417 goto out; 2418 /* Can we just ignore htree data? */ 2419 if (ext4_has_metadata_csum(sb)) { 2420 EXT4_ERROR_INODE(dir, 2421 "Directory has corrupted htree index."); 2422 retval = -EFSCORRUPTED; 2423 goto out; 2424 } 2425 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX); 2426 dx_fallback++; 2427 retval = ext4_mark_inode_dirty(handle, dir); 2428 if (unlikely(retval)) 2429 goto out; 2430 } 2431 blocks = dir->i_size >> sb->s_blocksize_bits; 2432 for (block = 0; block < blocks; block++) { 2433 bh = ext4_read_dirblock(dir, block, DIRENT); 2434 if (bh == NULL) { 2435 bh = ext4_bread(handle, dir, block, 2436 EXT4_GET_BLOCKS_CREATE); 2437 goto add_to_new_block; 2438 } 2439 if (IS_ERR(bh)) { 2440 retval = PTR_ERR(bh); 2441 bh = NULL; 2442 goto out; 2443 } 2444 retval = add_dirent_to_buf(handle, &fname, dir, inode, 2445 NULL, bh); 2446 if (retval != -ENOSPC) 2447 goto out; 2448 2449 if (blocks == 1 && !dx_fallback && 2450 ext4_has_feature_dir_index(sb)) { 2451 retval = make_indexed_dir(handle, &fname, dir, 2452 inode, bh); 2453 bh = NULL; /* make_indexed_dir releases bh */ 2454 goto out; 2455 } 2456 brelse(bh); 2457 } 2458 bh = ext4_append(handle, dir, &block); 2459 add_to_new_block: 2460 if (IS_ERR(bh)) { 2461 retval = PTR_ERR(bh); 2462 bh = NULL; 2463 goto out; 2464 } 2465 de = (struct ext4_dir_entry_2 *) bh->b_data; 2466 de->inode = 0; 2467 de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize); 2468 2469 if (csum_size) 2470 ext4_initialize_dirent_tail(bh, blocksize); 2471 2472 retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh); 2473 out: 2474 ext4_fname_free_filename(&fname); 2475 brelse(bh); 2476 if (retval == 0) 2477 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY); 2478 return retval; 2479 } 2480 2481 /* 2482 * Returns 0 for success, or a negative error value 2483 */ 2484 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname, 2485 struct inode *dir, struct inode *inode) 2486 { 2487 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 2488 struct dx_entry *entries, *at; 2489 struct buffer_head *bh; 2490 struct super_block *sb = dir->i_sb; 2491 struct ext4_dir_entry_2 *de; 2492 int restart; 2493 int err; 2494 2495 again: 2496 restart = 0; 2497 frame = dx_probe(fname, dir, NULL, frames); 2498 if (IS_ERR(frame)) 2499 return PTR_ERR(frame); 2500 entries = frame->entries; 2501 at = frame->at; 2502 bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT_HTREE); 2503 if (IS_ERR(bh)) { 2504 err = PTR_ERR(bh); 2505 bh = NULL; 2506 goto cleanup; 2507 } 2508 2509 BUFFER_TRACE(bh, "get_write_access"); 2510 err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE); 2511 if (err) 2512 goto journal_error; 2513 2514 err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh); 2515 if (err != -ENOSPC) 2516 goto cleanup; 2517 2518 err = 0; 2519 /* Block full, should compress but for now just split */ 2520 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n", 2521 dx_get_count(entries), dx_get_limit(entries))); 2522 /* Need to split index? */ 2523 if (dx_get_count(entries) == dx_get_limit(entries)) { 2524 ext4_lblk_t newblock; 2525 int levels = frame - frames + 1; 2526 unsigned int icount; 2527 int add_level = 1; 2528 struct dx_entry *entries2; 2529 struct dx_node *node2; 2530 struct buffer_head *bh2; 2531 2532 while (frame > frames) { 2533 if (dx_get_count((frame - 1)->entries) < 2534 dx_get_limit((frame - 1)->entries)) { 2535 add_level = 0; 2536 break; 2537 } 2538 frame--; /* split higher index block */ 2539 at = frame->at; 2540 entries = frame->entries; 2541 restart = 1; 2542 } 2543 if (add_level && levels == ext4_dir_htree_level(sb)) { 2544 ext4_warning(sb, "Directory (ino: %lu) index full, " 2545 "reach max htree level :%d", 2546 dir->i_ino, levels); 2547 if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) { 2548 ext4_warning(sb, "Large directory feature is " 2549 "not enabled on this " 2550 "filesystem"); 2551 } 2552 err = -ENOSPC; 2553 goto cleanup; 2554 } 2555 icount = dx_get_count(entries); 2556 bh2 = ext4_append(handle, dir, &newblock); 2557 if (IS_ERR(bh2)) { 2558 err = PTR_ERR(bh2); 2559 goto cleanup; 2560 } 2561 node2 = (struct dx_node *)(bh2->b_data); 2562 entries2 = node2->entries; 2563 memset(&node2->fake, 0, sizeof(struct fake_dirent)); 2564 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize, 2565 sb->s_blocksize); 2566 BUFFER_TRACE(frame->bh, "get_write_access"); 2567 err = ext4_journal_get_write_access(handle, sb, frame->bh, 2568 EXT4_JTR_NONE); 2569 if (err) 2570 goto journal_error; 2571 if (!add_level) { 2572 unsigned icount1 = icount/2, icount2 = icount - icount1; 2573 unsigned hash2 = dx_get_hash(entries + icount1); 2574 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n", 2575 icount1, icount2)); 2576 2577 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */ 2578 err = ext4_journal_get_write_access(handle, sb, 2579 (frame - 1)->bh, 2580 EXT4_JTR_NONE); 2581 if (err) 2582 goto journal_error; 2583 2584 memcpy((char *) entries2, (char *) (entries + icount1), 2585 icount2 * sizeof(struct dx_entry)); 2586 dx_set_count(entries, icount1); 2587 dx_set_count(entries2, icount2); 2588 dx_set_limit(entries2, dx_node_limit(dir)); 2589 2590 /* Which index block gets the new entry? */ 2591 if (at - entries >= icount1) { 2592 frame->at = at - entries - icount1 + entries2; 2593 frame->entries = entries = entries2; 2594 swap(frame->bh, bh2); 2595 } 2596 dx_insert_block((frame - 1), hash2, newblock); 2597 dxtrace(dx_show_index("node", frame->entries)); 2598 dxtrace(dx_show_index("node", 2599 ((struct dx_node *) bh2->b_data)->entries)); 2600 err = ext4_handle_dirty_dx_node(handle, dir, bh2); 2601 if (err) 2602 goto journal_error; 2603 brelse (bh2); 2604 err = ext4_handle_dirty_dx_node(handle, dir, 2605 (frame - 1)->bh); 2606 if (err) 2607 goto journal_error; 2608 err = ext4_handle_dirty_dx_node(handle, dir, 2609 frame->bh); 2610 if (restart || err) 2611 goto journal_error; 2612 } else { 2613 struct dx_root *dxroot; 2614 memcpy((char *) entries2, (char *) entries, 2615 icount * sizeof(struct dx_entry)); 2616 dx_set_limit(entries2, dx_node_limit(dir)); 2617 2618 /* Set up root */ 2619 dx_set_count(entries, 1); 2620 dx_set_block(entries + 0, newblock); 2621 dxroot = (struct dx_root *)frames[0].bh->b_data; 2622 dxroot->info.indirect_levels += 1; 2623 dxtrace(printk(KERN_DEBUG 2624 "Creating %d level index...\n", 2625 dxroot->info.indirect_levels)); 2626 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 2627 if (err) 2628 goto journal_error; 2629 err = ext4_handle_dirty_dx_node(handle, dir, bh2); 2630 brelse(bh2); 2631 restart = 1; 2632 goto journal_error; 2633 } 2634 } 2635 de = do_split(handle, dir, &bh, frame, &fname->hinfo); 2636 if (IS_ERR(de)) { 2637 err = PTR_ERR(de); 2638 goto cleanup; 2639 } 2640 err = add_dirent_to_buf(handle, fname, dir, inode, de, bh); 2641 goto cleanup; 2642 2643 journal_error: 2644 ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */ 2645 cleanup: 2646 brelse(bh); 2647 dx_release(frames); 2648 /* @restart is true means htree-path has been changed, we need to 2649 * repeat dx_probe() to find out valid htree-path 2650 */ 2651 if (restart && err == 0) 2652 goto again; 2653 return err; 2654 } 2655 2656 /* 2657 * ext4_generic_delete_entry deletes a directory entry by merging it 2658 * with the previous entry 2659 */ 2660 int ext4_generic_delete_entry(struct inode *dir, 2661 struct ext4_dir_entry_2 *de_del, 2662 struct buffer_head *bh, 2663 void *entry_buf, 2664 int buf_size, 2665 int csum_size) 2666 { 2667 struct ext4_dir_entry_2 *de, *pde; 2668 unsigned int blocksize = dir->i_sb->s_blocksize; 2669 int i; 2670 2671 i = 0; 2672 pde = NULL; 2673 de = entry_buf; 2674 while (i < buf_size - csum_size) { 2675 if (ext4_check_dir_entry(dir, NULL, de, bh, 2676 entry_buf, buf_size, i)) 2677 return -EFSCORRUPTED; 2678 if (de == de_del) { 2679 if (pde) { 2680 pde->rec_len = ext4_rec_len_to_disk( 2681 ext4_rec_len_from_disk(pde->rec_len, 2682 blocksize) + 2683 ext4_rec_len_from_disk(de->rec_len, 2684 blocksize), 2685 blocksize); 2686 2687 /* wipe entire dir_entry */ 2688 memset(de, 0, ext4_rec_len_from_disk(de->rec_len, 2689 blocksize)); 2690 } else { 2691 /* wipe dir_entry excluding the rec_len field */ 2692 de->inode = 0; 2693 memset(&de->name_len, 0, 2694 ext4_rec_len_from_disk(de->rec_len, 2695 blocksize) - 2696 offsetof(struct ext4_dir_entry_2, 2697 name_len)); 2698 } 2699 2700 inode_inc_iversion(dir); 2701 return 0; 2702 } 2703 i += ext4_rec_len_from_disk(de->rec_len, blocksize); 2704 pde = de; 2705 de = ext4_next_entry(de, blocksize); 2706 } 2707 return -ENOENT; 2708 } 2709 2710 static int ext4_delete_entry(handle_t *handle, 2711 struct inode *dir, 2712 struct ext4_dir_entry_2 *de_del, 2713 struct buffer_head *bh) 2714 { 2715 int err, csum_size = 0; 2716 2717 if (ext4_has_inline_data(dir)) { 2718 int has_inline_data = 1; 2719 err = ext4_delete_inline_entry(handle, dir, de_del, bh, 2720 &has_inline_data); 2721 if (has_inline_data) 2722 return err; 2723 } 2724 2725 if (ext4_has_metadata_csum(dir->i_sb)) 2726 csum_size = sizeof(struct ext4_dir_entry_tail); 2727 2728 BUFFER_TRACE(bh, "get_write_access"); 2729 err = ext4_journal_get_write_access(handle, dir->i_sb, bh, 2730 EXT4_JTR_NONE); 2731 if (unlikely(err)) 2732 goto out; 2733 2734 err = ext4_generic_delete_entry(dir, de_del, bh, bh->b_data, 2735 dir->i_sb->s_blocksize, csum_size); 2736 if (err) 2737 goto out; 2738 2739 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); 2740 err = ext4_handle_dirty_dirblock(handle, dir, bh); 2741 if (unlikely(err)) 2742 goto out; 2743 2744 return 0; 2745 out: 2746 if (err != -ENOENT) 2747 ext4_std_error(dir->i_sb, err); 2748 return err; 2749 } 2750 2751 /* 2752 * Set directory link count to 1 if nlinks > EXT4_LINK_MAX, or if nlinks == 2 2753 * since this indicates that nlinks count was previously 1 to avoid overflowing 2754 * the 16-bit i_links_count field on disk. Directories with i_nlink == 1 mean 2755 * that subdirectory link counts are not being maintained accurately. 2756 * 2757 * The caller has already checked for i_nlink overflow in case the DIR_LINK 2758 * feature is not enabled and returned -EMLINK. The is_dx() check is a proxy 2759 * for checking S_ISDIR(inode) (since the INODE_INDEX feature will not be set 2760 * on regular files) and to avoid creating huge/slow non-HTREE directories. 2761 */ 2762 static void ext4_inc_count(struct inode *inode) 2763 { 2764 inc_nlink(inode); 2765 if (is_dx(inode) && 2766 (inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2)) 2767 set_nlink(inode, 1); 2768 } 2769 2770 /* 2771 * If a directory had nlink == 1, then we should let it be 1. This indicates 2772 * directory has >EXT4_LINK_MAX subdirs. 2773 */ 2774 static void ext4_dec_count(struct inode *inode) 2775 { 2776 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2) 2777 drop_nlink(inode); 2778 } 2779 2780 2781 /* 2782 * Add non-directory inode to a directory. On success, the inode reference is 2783 * consumed by dentry is instantiation. This is also indicated by clearing of 2784 * *inodep pointer. On failure, the caller is responsible for dropping the 2785 * inode reference in the safe context. 2786 */ 2787 static int ext4_add_nondir(handle_t *handle, 2788 struct dentry *dentry, struct inode **inodep) 2789 { 2790 struct inode *dir = d_inode(dentry->d_parent); 2791 struct inode *inode = *inodep; 2792 int err = ext4_add_entry(handle, dentry, inode); 2793 if (!err) { 2794 err = ext4_mark_inode_dirty(handle, inode); 2795 if (IS_DIRSYNC(dir)) 2796 ext4_handle_sync(handle); 2797 d_instantiate_new(dentry, inode); 2798 *inodep = NULL; 2799 return err; 2800 } 2801 drop_nlink(inode); 2802 ext4_orphan_add(handle, inode); 2803 unlock_new_inode(inode); 2804 return err; 2805 } 2806 2807 /* 2808 * By the time this is called, we already have created 2809 * the directory cache entry for the new file, but it 2810 * is so far negative - it has no inode. 2811 * 2812 * If the create succeeds, we fill in the inode information 2813 * with d_instantiate(). 2814 */ 2815 static int ext4_create(struct mnt_idmap *idmap, struct inode *dir, 2816 struct dentry *dentry, umode_t mode, bool excl) 2817 { 2818 handle_t *handle; 2819 struct inode *inode; 2820 int err, credits, retries = 0; 2821 2822 err = dquot_initialize(dir); 2823 if (err) 2824 return err; 2825 2826 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2827 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2828 retry: 2829 inode = ext4_new_inode_start_handle(idmap, dir, mode, &dentry->d_name, 2830 0, NULL, EXT4_HT_DIR, credits); 2831 handle = ext4_journal_current_handle(); 2832 err = PTR_ERR(inode); 2833 if (!IS_ERR(inode)) { 2834 inode->i_op = &ext4_file_inode_operations; 2835 inode->i_fop = &ext4_file_operations; 2836 ext4_set_aops(inode); 2837 err = ext4_add_nondir(handle, dentry, &inode); 2838 if (!err) 2839 ext4_fc_track_create(handle, dentry); 2840 } 2841 if (handle) 2842 ext4_journal_stop(handle); 2843 if (!IS_ERR_OR_NULL(inode)) 2844 iput(inode); 2845 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2846 goto retry; 2847 return err; 2848 } 2849 2850 static int ext4_mknod(struct mnt_idmap *idmap, struct inode *dir, 2851 struct dentry *dentry, umode_t mode, dev_t rdev) 2852 { 2853 handle_t *handle; 2854 struct inode *inode; 2855 int err, credits, retries = 0; 2856 2857 err = dquot_initialize(dir); 2858 if (err) 2859 return err; 2860 2861 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2862 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2863 retry: 2864 inode = ext4_new_inode_start_handle(idmap, dir, mode, &dentry->d_name, 2865 0, NULL, EXT4_HT_DIR, credits); 2866 handle = ext4_journal_current_handle(); 2867 err = PTR_ERR(inode); 2868 if (!IS_ERR(inode)) { 2869 init_special_inode(inode, inode->i_mode, rdev); 2870 inode->i_op = &ext4_special_inode_operations; 2871 err = ext4_add_nondir(handle, dentry, &inode); 2872 if (!err) 2873 ext4_fc_track_create(handle, dentry); 2874 } 2875 if (handle) 2876 ext4_journal_stop(handle); 2877 if (!IS_ERR_OR_NULL(inode)) 2878 iput(inode); 2879 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2880 goto retry; 2881 return err; 2882 } 2883 2884 static int ext4_tmpfile(struct mnt_idmap *idmap, struct inode *dir, 2885 struct file *file, umode_t mode) 2886 { 2887 handle_t *handle; 2888 struct inode *inode; 2889 int err, retries = 0; 2890 2891 err = dquot_initialize(dir); 2892 if (err) 2893 return err; 2894 2895 retry: 2896 inode = ext4_new_inode_start_handle(idmap, dir, mode, 2897 NULL, 0, NULL, 2898 EXT4_HT_DIR, 2899 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) + 2900 4 + EXT4_XATTR_TRANS_BLOCKS); 2901 handle = ext4_journal_current_handle(); 2902 err = PTR_ERR(inode); 2903 if (!IS_ERR(inode)) { 2904 inode->i_op = &ext4_file_inode_operations; 2905 inode->i_fop = &ext4_file_operations; 2906 ext4_set_aops(inode); 2907 d_tmpfile(file, inode); 2908 err = ext4_orphan_add(handle, inode); 2909 if (err) 2910 goto err_unlock_inode; 2911 mark_inode_dirty(inode); 2912 unlock_new_inode(inode); 2913 } 2914 if (handle) 2915 ext4_journal_stop(handle); 2916 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2917 goto retry; 2918 return finish_open_simple(file, err); 2919 err_unlock_inode: 2920 ext4_journal_stop(handle); 2921 unlock_new_inode(inode); 2922 return err; 2923 } 2924 2925 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode, 2926 struct ext4_dir_entry_2 *de, 2927 int blocksize, int csum_size, 2928 unsigned int parent_ino, int dotdot_real_len) 2929 { 2930 de->inode = cpu_to_le32(inode->i_ino); 2931 de->name_len = 1; 2932 de->rec_len = ext4_rec_len_to_disk(ext4_dir_rec_len(de->name_len, NULL), 2933 blocksize); 2934 strcpy(de->name, "."); 2935 ext4_set_de_type(inode->i_sb, de, S_IFDIR); 2936 2937 de = ext4_next_entry(de, blocksize); 2938 de->inode = cpu_to_le32(parent_ino); 2939 de->name_len = 2; 2940 if (!dotdot_real_len) 2941 de->rec_len = ext4_rec_len_to_disk(blocksize - 2942 (csum_size + ext4_dir_rec_len(1, NULL)), 2943 blocksize); 2944 else 2945 de->rec_len = ext4_rec_len_to_disk( 2946 ext4_dir_rec_len(de->name_len, NULL), 2947 blocksize); 2948 strcpy(de->name, ".."); 2949 ext4_set_de_type(inode->i_sb, de, S_IFDIR); 2950 2951 return ext4_next_entry(de, blocksize); 2952 } 2953 2954 int ext4_init_new_dir(handle_t *handle, struct inode *dir, 2955 struct inode *inode) 2956 { 2957 struct buffer_head *dir_block = NULL; 2958 struct ext4_dir_entry_2 *de; 2959 ext4_lblk_t block = 0; 2960 unsigned int blocksize = dir->i_sb->s_blocksize; 2961 int csum_size = 0; 2962 int err; 2963 2964 if (ext4_has_metadata_csum(dir->i_sb)) 2965 csum_size = sizeof(struct ext4_dir_entry_tail); 2966 2967 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) { 2968 err = ext4_try_create_inline_dir(handle, dir, inode); 2969 if (err < 0 && err != -ENOSPC) 2970 goto out; 2971 if (!err) 2972 goto out; 2973 } 2974 2975 inode->i_size = 0; 2976 dir_block = ext4_append(handle, inode, &block); 2977 if (IS_ERR(dir_block)) 2978 return PTR_ERR(dir_block); 2979 de = (struct ext4_dir_entry_2 *)dir_block->b_data; 2980 ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0); 2981 set_nlink(inode, 2); 2982 if (csum_size) 2983 ext4_initialize_dirent_tail(dir_block, blocksize); 2984 2985 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata"); 2986 err = ext4_handle_dirty_dirblock(handle, inode, dir_block); 2987 if (err) 2988 goto out; 2989 set_buffer_verified(dir_block); 2990 out: 2991 brelse(dir_block); 2992 return err; 2993 } 2994 2995 static int ext4_mkdir(struct mnt_idmap *idmap, struct inode *dir, 2996 struct dentry *dentry, umode_t mode) 2997 { 2998 handle_t *handle; 2999 struct inode *inode; 3000 int err, err2 = 0, credits, retries = 0; 3001 3002 if (EXT4_DIR_LINK_MAX(dir)) 3003 return -EMLINK; 3004 3005 err = dquot_initialize(dir); 3006 if (err) 3007 return err; 3008 3009 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3010 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 3011 retry: 3012 inode = ext4_new_inode_start_handle(idmap, dir, S_IFDIR | mode, 3013 &dentry->d_name, 3014 0, NULL, EXT4_HT_DIR, credits); 3015 handle = ext4_journal_current_handle(); 3016 err = PTR_ERR(inode); 3017 if (IS_ERR(inode)) 3018 goto out_stop; 3019 3020 inode->i_op = &ext4_dir_inode_operations; 3021 inode->i_fop = &ext4_dir_operations; 3022 err = ext4_init_new_dir(handle, dir, inode); 3023 if (err) 3024 goto out_clear_inode; 3025 err = ext4_mark_inode_dirty(handle, inode); 3026 if (!err) 3027 err = ext4_add_entry(handle, dentry, inode); 3028 if (err) { 3029 out_clear_inode: 3030 clear_nlink(inode); 3031 ext4_orphan_add(handle, inode); 3032 unlock_new_inode(inode); 3033 err2 = ext4_mark_inode_dirty(handle, inode); 3034 if (unlikely(err2)) 3035 err = err2; 3036 ext4_journal_stop(handle); 3037 iput(inode); 3038 goto out_retry; 3039 } 3040 ext4_inc_count(dir); 3041 3042 ext4_update_dx_flag(dir); 3043 err = ext4_mark_inode_dirty(handle, dir); 3044 if (err) 3045 goto out_clear_inode; 3046 d_instantiate_new(dentry, inode); 3047 ext4_fc_track_create(handle, dentry); 3048 if (IS_DIRSYNC(dir)) 3049 ext4_handle_sync(handle); 3050 3051 out_stop: 3052 if (handle) 3053 ext4_journal_stop(handle); 3054 out_retry: 3055 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 3056 goto retry; 3057 return err; 3058 } 3059 3060 /* 3061 * routine to check that the specified directory is empty (for rmdir) 3062 */ 3063 bool ext4_empty_dir(struct inode *inode) 3064 { 3065 unsigned int offset; 3066 struct buffer_head *bh; 3067 struct ext4_dir_entry_2 *de; 3068 struct super_block *sb; 3069 3070 if (ext4_has_inline_data(inode)) { 3071 int has_inline_data = 1; 3072 int ret; 3073 3074 ret = empty_inline_dir(inode, &has_inline_data); 3075 if (has_inline_data) 3076 return ret; 3077 } 3078 3079 sb = inode->i_sb; 3080 if (inode->i_size < ext4_dir_rec_len(1, NULL) + 3081 ext4_dir_rec_len(2, NULL)) { 3082 EXT4_ERROR_INODE(inode, "invalid size"); 3083 return false; 3084 } 3085 /* The first directory block must not be a hole, 3086 * so treat it as DIRENT_HTREE 3087 */ 3088 bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE); 3089 if (IS_ERR(bh)) 3090 return false; 3091 3092 de = (struct ext4_dir_entry_2 *) bh->b_data; 3093 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size, 3094 0) || 3095 le32_to_cpu(de->inode) != inode->i_ino || strcmp(".", de->name)) { 3096 ext4_warning_inode(inode, "directory missing '.'"); 3097 brelse(bh); 3098 return false; 3099 } 3100 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); 3101 de = ext4_next_entry(de, sb->s_blocksize); 3102 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size, 3103 offset) || 3104 le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) { 3105 ext4_warning_inode(inode, "directory missing '..'"); 3106 brelse(bh); 3107 return false; 3108 } 3109 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); 3110 while (offset < inode->i_size) { 3111 if (!(offset & (sb->s_blocksize - 1))) { 3112 unsigned int lblock; 3113 brelse(bh); 3114 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb); 3115 bh = ext4_read_dirblock(inode, lblock, EITHER); 3116 if (bh == NULL) { 3117 offset += sb->s_blocksize; 3118 continue; 3119 } 3120 if (IS_ERR(bh)) 3121 return false; 3122 } 3123 de = (struct ext4_dir_entry_2 *) (bh->b_data + 3124 (offset & (sb->s_blocksize - 1))); 3125 if (ext4_check_dir_entry(inode, NULL, de, bh, 3126 bh->b_data, bh->b_size, offset) || 3127 le32_to_cpu(de->inode)) { 3128 brelse(bh); 3129 return false; 3130 } 3131 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); 3132 } 3133 brelse(bh); 3134 return true; 3135 } 3136 3137 static int ext4_rmdir(struct inode *dir, struct dentry *dentry) 3138 { 3139 int retval; 3140 struct inode *inode; 3141 struct buffer_head *bh; 3142 struct ext4_dir_entry_2 *de; 3143 handle_t *handle = NULL; 3144 3145 if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb)))) 3146 return -EIO; 3147 3148 /* Initialize quotas before so that eventual writes go in 3149 * separate transaction */ 3150 retval = dquot_initialize(dir); 3151 if (retval) 3152 return retval; 3153 retval = dquot_initialize(d_inode(dentry)); 3154 if (retval) 3155 return retval; 3156 3157 retval = -ENOENT; 3158 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); 3159 if (IS_ERR(bh)) 3160 return PTR_ERR(bh); 3161 if (!bh) 3162 goto end_rmdir; 3163 3164 inode = d_inode(dentry); 3165 3166 retval = -EFSCORRUPTED; 3167 if (le32_to_cpu(de->inode) != inode->i_ino) 3168 goto end_rmdir; 3169 3170 retval = -ENOTEMPTY; 3171 if (!ext4_empty_dir(inode)) 3172 goto end_rmdir; 3173 3174 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3175 EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); 3176 if (IS_ERR(handle)) { 3177 retval = PTR_ERR(handle); 3178 handle = NULL; 3179 goto end_rmdir; 3180 } 3181 3182 if (IS_DIRSYNC(dir)) 3183 ext4_handle_sync(handle); 3184 3185 retval = ext4_delete_entry(handle, dir, de, bh); 3186 if (retval) 3187 goto end_rmdir; 3188 if (!EXT4_DIR_LINK_EMPTY(inode)) 3189 ext4_warning_inode(inode, 3190 "empty directory '%.*s' has too many links (%u)", 3191 dentry->d_name.len, dentry->d_name.name, 3192 inode->i_nlink); 3193 inode_inc_iversion(inode); 3194 clear_nlink(inode); 3195 /* There's no need to set i_disksize: the fact that i_nlink is 3196 * zero will ensure that the right thing happens during any 3197 * recovery. */ 3198 inode->i_size = 0; 3199 ext4_orphan_add(handle, inode); 3200 inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode); 3201 retval = ext4_mark_inode_dirty(handle, inode); 3202 if (retval) 3203 goto end_rmdir; 3204 ext4_dec_count(dir); 3205 ext4_update_dx_flag(dir); 3206 ext4_fc_track_unlink(handle, dentry); 3207 retval = ext4_mark_inode_dirty(handle, dir); 3208 3209 #if IS_ENABLED(CONFIG_UNICODE) 3210 /* VFS negative dentries are incompatible with Encoding and 3211 * Case-insensitiveness. Eventually we'll want avoid 3212 * invalidating the dentries here, alongside with returning the 3213 * negative dentries at ext4_lookup(), when it is better 3214 * supported by the VFS for the CI case. 3215 */ 3216 if (IS_CASEFOLDED(dir)) 3217 d_invalidate(dentry); 3218 #endif 3219 3220 end_rmdir: 3221 brelse(bh); 3222 if (handle) 3223 ext4_journal_stop(handle); 3224 return retval; 3225 } 3226 3227 int __ext4_unlink(struct inode *dir, const struct qstr *d_name, 3228 struct inode *inode, 3229 struct dentry *dentry /* NULL during fast_commit recovery */) 3230 { 3231 int retval = -ENOENT; 3232 struct buffer_head *bh; 3233 struct ext4_dir_entry_2 *de; 3234 handle_t *handle; 3235 int skip_remove_dentry = 0; 3236 3237 /* 3238 * Keep this outside the transaction; it may have to set up the 3239 * directory's encryption key, which isn't GFP_NOFS-safe. 3240 */ 3241 bh = ext4_find_entry(dir, d_name, &de, NULL); 3242 if (IS_ERR(bh)) 3243 return PTR_ERR(bh); 3244 3245 if (!bh) 3246 return -ENOENT; 3247 3248 if (le32_to_cpu(de->inode) != inode->i_ino) { 3249 /* 3250 * It's okay if we find dont find dentry which matches 3251 * the inode. That's because it might have gotten 3252 * renamed to a different inode number 3253 */ 3254 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY) 3255 skip_remove_dentry = 1; 3256 else 3257 goto out_bh; 3258 } 3259 3260 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3261 EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); 3262 if (IS_ERR(handle)) { 3263 retval = PTR_ERR(handle); 3264 goto out_bh; 3265 } 3266 3267 if (IS_DIRSYNC(dir)) 3268 ext4_handle_sync(handle); 3269 3270 if (!skip_remove_dentry) { 3271 retval = ext4_delete_entry(handle, dir, de, bh); 3272 if (retval) 3273 goto out_handle; 3274 dir->i_ctime = dir->i_mtime = current_time(dir); 3275 ext4_update_dx_flag(dir); 3276 retval = ext4_mark_inode_dirty(handle, dir); 3277 if (retval) 3278 goto out_handle; 3279 } else { 3280 retval = 0; 3281 } 3282 if (inode->i_nlink == 0) 3283 ext4_warning_inode(inode, "Deleting file '%.*s' with no links", 3284 d_name->len, d_name->name); 3285 else 3286 drop_nlink(inode); 3287 if (!inode->i_nlink) 3288 ext4_orphan_add(handle, inode); 3289 inode->i_ctime = current_time(inode); 3290 retval = ext4_mark_inode_dirty(handle, inode); 3291 if (dentry && !retval) 3292 ext4_fc_track_unlink(handle, dentry); 3293 out_handle: 3294 ext4_journal_stop(handle); 3295 out_bh: 3296 brelse(bh); 3297 return retval; 3298 } 3299 3300 static int ext4_unlink(struct inode *dir, struct dentry *dentry) 3301 { 3302 int retval; 3303 3304 if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb)))) 3305 return -EIO; 3306 3307 trace_ext4_unlink_enter(dir, dentry); 3308 /* 3309 * Initialize quotas before so that eventual writes go 3310 * in separate transaction 3311 */ 3312 retval = dquot_initialize(dir); 3313 if (retval) 3314 goto out_trace; 3315 retval = dquot_initialize(d_inode(dentry)); 3316 if (retval) 3317 goto out_trace; 3318 3319 retval = __ext4_unlink(dir, &dentry->d_name, d_inode(dentry), dentry); 3320 #if IS_ENABLED(CONFIG_UNICODE) 3321 /* VFS negative dentries are incompatible with Encoding and 3322 * Case-insensitiveness. Eventually we'll want avoid 3323 * invalidating the dentries here, alongside with returning the 3324 * negative dentries at ext4_lookup(), when it is better 3325 * supported by the VFS for the CI case. 3326 */ 3327 if (IS_CASEFOLDED(dir)) 3328 d_invalidate(dentry); 3329 #endif 3330 3331 out_trace: 3332 trace_ext4_unlink_exit(dentry, retval); 3333 return retval; 3334 } 3335 3336 static int ext4_init_symlink_block(handle_t *handle, struct inode *inode, 3337 struct fscrypt_str *disk_link) 3338 { 3339 struct buffer_head *bh; 3340 char *kaddr; 3341 int err = 0; 3342 3343 bh = ext4_bread(handle, inode, 0, EXT4_GET_BLOCKS_CREATE); 3344 if (IS_ERR(bh)) 3345 return PTR_ERR(bh); 3346 3347 BUFFER_TRACE(bh, "get_write_access"); 3348 err = ext4_journal_get_write_access(handle, inode->i_sb, bh, EXT4_JTR_NONE); 3349 if (err) 3350 goto out; 3351 3352 kaddr = (char *)bh->b_data; 3353 memcpy(kaddr, disk_link->name, disk_link->len); 3354 inode->i_size = disk_link->len - 1; 3355 EXT4_I(inode)->i_disksize = inode->i_size; 3356 err = ext4_handle_dirty_metadata(handle, inode, bh); 3357 out: 3358 brelse(bh); 3359 return err; 3360 } 3361 3362 static int ext4_symlink(struct mnt_idmap *idmap, struct inode *dir, 3363 struct dentry *dentry, const char *symname) 3364 { 3365 handle_t *handle; 3366 struct inode *inode; 3367 int err, len = strlen(symname); 3368 int credits; 3369 struct fscrypt_str disk_link; 3370 int retries = 0; 3371 3372 if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb)))) 3373 return -EIO; 3374 3375 err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize, 3376 &disk_link); 3377 if (err) 3378 return err; 3379 3380 err = dquot_initialize(dir); 3381 if (err) 3382 return err; 3383 3384 /* 3385 * EXT4_INDEX_EXTRA_TRANS_BLOCKS for addition of entry into the 3386 * directory. +3 for inode, inode bitmap, group descriptor allocation. 3387 * EXT4_DATA_TRANS_BLOCKS for the data block allocation and 3388 * modification. 3389 */ 3390 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3391 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3; 3392 retry: 3393 inode = ext4_new_inode_start_handle(idmap, dir, S_IFLNK|S_IRWXUGO, 3394 &dentry->d_name, 0, NULL, 3395 EXT4_HT_DIR, credits); 3396 handle = ext4_journal_current_handle(); 3397 if (IS_ERR(inode)) { 3398 if (handle) 3399 ext4_journal_stop(handle); 3400 err = PTR_ERR(inode); 3401 goto out_retry; 3402 } 3403 3404 if (IS_ENCRYPTED(inode)) { 3405 err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link); 3406 if (err) 3407 goto err_drop_inode; 3408 inode->i_op = &ext4_encrypted_symlink_inode_operations; 3409 } else { 3410 if ((disk_link.len > EXT4_N_BLOCKS * 4)) { 3411 inode->i_op = &ext4_symlink_inode_operations; 3412 } else { 3413 inode->i_op = &ext4_fast_symlink_inode_operations; 3414 inode->i_link = (char *)&EXT4_I(inode)->i_data; 3415 } 3416 } 3417 3418 if ((disk_link.len > EXT4_N_BLOCKS * 4)) { 3419 /* alloc symlink block and fill it */ 3420 err = ext4_init_symlink_block(handle, inode, &disk_link); 3421 if (err) 3422 goto err_drop_inode; 3423 } else { 3424 /* clear the extent format for fast symlink */ 3425 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS); 3426 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name, 3427 disk_link.len); 3428 inode->i_size = disk_link.len - 1; 3429 EXT4_I(inode)->i_disksize = inode->i_size; 3430 } 3431 err = ext4_add_nondir(handle, dentry, &inode); 3432 if (handle) 3433 ext4_journal_stop(handle); 3434 iput(inode); 3435 goto out_retry; 3436 3437 err_drop_inode: 3438 clear_nlink(inode); 3439 ext4_orphan_add(handle, inode); 3440 unlock_new_inode(inode); 3441 if (handle) 3442 ext4_journal_stop(handle); 3443 iput(inode); 3444 out_retry: 3445 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 3446 goto retry; 3447 if (disk_link.name != (unsigned char *)symname) 3448 kfree(disk_link.name); 3449 return err; 3450 } 3451 3452 int __ext4_link(struct inode *dir, struct inode *inode, struct dentry *dentry) 3453 { 3454 handle_t *handle; 3455 int err, retries = 0; 3456 retry: 3457 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3458 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3459 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1); 3460 if (IS_ERR(handle)) 3461 return PTR_ERR(handle); 3462 3463 if (IS_DIRSYNC(dir)) 3464 ext4_handle_sync(handle); 3465 3466 inode->i_ctime = current_time(inode); 3467 ext4_inc_count(inode); 3468 ihold(inode); 3469 3470 err = ext4_add_entry(handle, dentry, inode); 3471 if (!err) { 3472 err = ext4_mark_inode_dirty(handle, inode); 3473 /* this can happen only for tmpfile being 3474 * linked the first time 3475 */ 3476 if (inode->i_nlink == 1) 3477 ext4_orphan_del(handle, inode); 3478 d_instantiate(dentry, inode); 3479 ext4_fc_track_link(handle, dentry); 3480 } else { 3481 drop_nlink(inode); 3482 iput(inode); 3483 } 3484 ext4_journal_stop(handle); 3485 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 3486 goto retry; 3487 return err; 3488 } 3489 3490 static int ext4_link(struct dentry *old_dentry, 3491 struct inode *dir, struct dentry *dentry) 3492 { 3493 struct inode *inode = d_inode(old_dentry); 3494 int err; 3495 3496 if (inode->i_nlink >= EXT4_LINK_MAX) 3497 return -EMLINK; 3498 3499 err = fscrypt_prepare_link(old_dentry, dir, dentry); 3500 if (err) 3501 return err; 3502 3503 if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) && 3504 (!projid_eq(EXT4_I(dir)->i_projid, 3505 EXT4_I(old_dentry->d_inode)->i_projid))) 3506 return -EXDEV; 3507 3508 err = dquot_initialize(dir); 3509 if (err) 3510 return err; 3511 return __ext4_link(dir, inode, dentry); 3512 } 3513 3514 /* 3515 * Try to find buffer head where contains the parent block. 3516 * It should be the inode block if it is inlined or the 1st block 3517 * if it is a normal dir. 3518 */ 3519 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle, 3520 struct inode *inode, 3521 int *retval, 3522 struct ext4_dir_entry_2 **parent_de, 3523 int *inlined) 3524 { 3525 struct buffer_head *bh; 3526 3527 if (!ext4_has_inline_data(inode)) { 3528 struct ext4_dir_entry_2 *de; 3529 unsigned int offset; 3530 3531 /* The first directory block must not be a hole, so 3532 * treat it as DIRENT_HTREE 3533 */ 3534 bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE); 3535 if (IS_ERR(bh)) { 3536 *retval = PTR_ERR(bh); 3537 return NULL; 3538 } 3539 3540 de = (struct ext4_dir_entry_2 *) bh->b_data; 3541 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, 3542 bh->b_size, 0) || 3543 le32_to_cpu(de->inode) != inode->i_ino || 3544 strcmp(".", de->name)) { 3545 EXT4_ERROR_INODE(inode, "directory missing '.'"); 3546 brelse(bh); 3547 *retval = -EFSCORRUPTED; 3548 return NULL; 3549 } 3550 offset = ext4_rec_len_from_disk(de->rec_len, 3551 inode->i_sb->s_blocksize); 3552 de = ext4_next_entry(de, inode->i_sb->s_blocksize); 3553 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, 3554 bh->b_size, offset) || 3555 le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) { 3556 EXT4_ERROR_INODE(inode, "directory missing '..'"); 3557 brelse(bh); 3558 *retval = -EFSCORRUPTED; 3559 return NULL; 3560 } 3561 *parent_de = de; 3562 3563 return bh; 3564 } 3565 3566 *inlined = 1; 3567 return ext4_get_first_inline_block(inode, parent_de, retval); 3568 } 3569 3570 struct ext4_renament { 3571 struct inode *dir; 3572 struct dentry *dentry; 3573 struct inode *inode; 3574 bool is_dir; 3575 int dir_nlink_delta; 3576 3577 /* entry for "dentry" */ 3578 struct buffer_head *bh; 3579 struct ext4_dir_entry_2 *de; 3580 int inlined; 3581 3582 /* entry for ".." in inode if it's a directory */ 3583 struct buffer_head *dir_bh; 3584 struct ext4_dir_entry_2 *parent_de; 3585 int dir_inlined; 3586 }; 3587 3588 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent) 3589 { 3590 int retval; 3591 3592 ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode, 3593 &retval, &ent->parent_de, 3594 &ent->dir_inlined); 3595 if (!ent->dir_bh) 3596 return retval; 3597 if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino) 3598 return -EFSCORRUPTED; 3599 BUFFER_TRACE(ent->dir_bh, "get_write_access"); 3600 return ext4_journal_get_write_access(handle, ent->dir->i_sb, 3601 ent->dir_bh, EXT4_JTR_NONE); 3602 } 3603 3604 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent, 3605 unsigned dir_ino) 3606 { 3607 int retval; 3608 3609 ent->parent_de->inode = cpu_to_le32(dir_ino); 3610 BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata"); 3611 if (!ent->dir_inlined) { 3612 if (is_dx(ent->inode)) { 3613 retval = ext4_handle_dirty_dx_node(handle, 3614 ent->inode, 3615 ent->dir_bh); 3616 } else { 3617 retval = ext4_handle_dirty_dirblock(handle, ent->inode, 3618 ent->dir_bh); 3619 } 3620 } else { 3621 retval = ext4_mark_inode_dirty(handle, ent->inode); 3622 } 3623 if (retval) { 3624 ext4_std_error(ent->dir->i_sb, retval); 3625 return retval; 3626 } 3627 return 0; 3628 } 3629 3630 static int ext4_setent(handle_t *handle, struct ext4_renament *ent, 3631 unsigned ino, unsigned file_type) 3632 { 3633 int retval, retval2; 3634 3635 BUFFER_TRACE(ent->bh, "get write access"); 3636 retval = ext4_journal_get_write_access(handle, ent->dir->i_sb, ent->bh, 3637 EXT4_JTR_NONE); 3638 if (retval) 3639 return retval; 3640 ent->de->inode = cpu_to_le32(ino); 3641 if (ext4_has_feature_filetype(ent->dir->i_sb)) 3642 ent->de->file_type = file_type; 3643 inode_inc_iversion(ent->dir); 3644 ent->dir->i_ctime = ent->dir->i_mtime = 3645 current_time(ent->dir); 3646 retval = ext4_mark_inode_dirty(handle, ent->dir); 3647 BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata"); 3648 if (!ent->inlined) { 3649 retval2 = ext4_handle_dirty_dirblock(handle, ent->dir, ent->bh); 3650 if (unlikely(retval2)) { 3651 ext4_std_error(ent->dir->i_sb, retval2); 3652 return retval2; 3653 } 3654 } 3655 return retval; 3656 } 3657 3658 static void ext4_resetent(handle_t *handle, struct ext4_renament *ent, 3659 unsigned ino, unsigned file_type) 3660 { 3661 struct ext4_renament old = *ent; 3662 int retval = 0; 3663 3664 /* 3665 * old->de could have moved from under us during make indexed dir, 3666 * so the old->de may no longer valid and need to find it again 3667 * before reset old inode info. 3668 */ 3669 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, 3670 &old.inlined); 3671 if (IS_ERR(old.bh)) 3672 retval = PTR_ERR(old.bh); 3673 if (!old.bh) 3674 retval = -ENOENT; 3675 if (retval) { 3676 ext4_std_error(old.dir->i_sb, retval); 3677 return; 3678 } 3679 3680 ext4_setent(handle, &old, ino, file_type); 3681 brelse(old.bh); 3682 } 3683 3684 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir, 3685 const struct qstr *d_name) 3686 { 3687 int retval = -ENOENT; 3688 struct buffer_head *bh; 3689 struct ext4_dir_entry_2 *de; 3690 3691 bh = ext4_find_entry(dir, d_name, &de, NULL); 3692 if (IS_ERR(bh)) 3693 return PTR_ERR(bh); 3694 if (bh) { 3695 retval = ext4_delete_entry(handle, dir, de, bh); 3696 brelse(bh); 3697 } 3698 return retval; 3699 } 3700 3701 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent, 3702 int force_reread) 3703 { 3704 int retval; 3705 /* 3706 * ent->de could have moved from under us during htree split, so make 3707 * sure that we are deleting the right entry. We might also be pointing 3708 * to a stale entry in the unused part of ent->bh so just checking inum 3709 * and the name isn't enough. 3710 */ 3711 if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino || 3712 ent->de->name_len != ent->dentry->d_name.len || 3713 strncmp(ent->de->name, ent->dentry->d_name.name, 3714 ent->de->name_len) || 3715 force_reread) { 3716 retval = ext4_find_delete_entry(handle, ent->dir, 3717 &ent->dentry->d_name); 3718 } else { 3719 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh); 3720 if (retval == -ENOENT) { 3721 retval = ext4_find_delete_entry(handle, ent->dir, 3722 &ent->dentry->d_name); 3723 } 3724 } 3725 3726 if (retval) { 3727 ext4_warning_inode(ent->dir, 3728 "Deleting old file: nlink %d, error=%d", 3729 ent->dir->i_nlink, retval); 3730 } 3731 } 3732 3733 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent) 3734 { 3735 if (ent->dir_nlink_delta) { 3736 if (ent->dir_nlink_delta == -1) 3737 ext4_dec_count(ent->dir); 3738 else 3739 ext4_inc_count(ent->dir); 3740 ext4_mark_inode_dirty(handle, ent->dir); 3741 } 3742 } 3743 3744 static struct inode *ext4_whiteout_for_rename(struct mnt_idmap *idmap, 3745 struct ext4_renament *ent, 3746 int credits, handle_t **h) 3747 { 3748 struct inode *wh; 3749 handle_t *handle; 3750 int retries = 0; 3751 3752 /* 3753 * for inode block, sb block, group summaries, 3754 * and inode bitmap 3755 */ 3756 credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) + 3757 EXT4_XATTR_TRANS_BLOCKS + 4); 3758 retry: 3759 wh = ext4_new_inode_start_handle(idmap, ent->dir, 3760 S_IFCHR | WHITEOUT_MODE, 3761 &ent->dentry->d_name, 0, NULL, 3762 EXT4_HT_DIR, credits); 3763 3764 handle = ext4_journal_current_handle(); 3765 if (IS_ERR(wh)) { 3766 if (handle) 3767 ext4_journal_stop(handle); 3768 if (PTR_ERR(wh) == -ENOSPC && 3769 ext4_should_retry_alloc(ent->dir->i_sb, &retries)) 3770 goto retry; 3771 } else { 3772 *h = handle; 3773 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV); 3774 wh->i_op = &ext4_special_inode_operations; 3775 } 3776 return wh; 3777 } 3778 3779 /* 3780 * Anybody can rename anything with this: the permission checks are left to the 3781 * higher-level routines. 3782 * 3783 * n.b. old_{dentry,inode) refers to the source dentry/inode 3784 * while new_{dentry,inode) refers to the destination dentry/inode 3785 * This comes from rename(const char *oldpath, const char *newpath) 3786 */ 3787 static int ext4_rename(struct mnt_idmap *idmap, struct inode *old_dir, 3788 struct dentry *old_dentry, struct inode *new_dir, 3789 struct dentry *new_dentry, unsigned int flags) 3790 { 3791 handle_t *handle = NULL; 3792 struct ext4_renament old = { 3793 .dir = old_dir, 3794 .dentry = old_dentry, 3795 .inode = d_inode(old_dentry), 3796 }; 3797 struct ext4_renament new = { 3798 .dir = new_dir, 3799 .dentry = new_dentry, 3800 .inode = d_inode(new_dentry), 3801 }; 3802 int force_reread; 3803 int retval; 3804 struct inode *whiteout = NULL; 3805 int credits; 3806 u8 old_file_type; 3807 3808 if (new.inode && new.inode->i_nlink == 0) { 3809 EXT4_ERROR_INODE(new.inode, 3810 "target of rename is already freed"); 3811 return -EFSCORRUPTED; 3812 } 3813 3814 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) && 3815 (!projid_eq(EXT4_I(new_dir)->i_projid, 3816 EXT4_I(old_dentry->d_inode)->i_projid))) 3817 return -EXDEV; 3818 3819 retval = dquot_initialize(old.dir); 3820 if (retval) 3821 return retval; 3822 retval = dquot_initialize(old.inode); 3823 if (retval) 3824 return retval; 3825 retval = dquot_initialize(new.dir); 3826 if (retval) 3827 return retval; 3828 3829 /* Initialize quotas before so that eventual writes go 3830 * in separate transaction */ 3831 if (new.inode) { 3832 retval = dquot_initialize(new.inode); 3833 if (retval) 3834 return retval; 3835 } 3836 3837 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, 3838 &old.inlined); 3839 if (IS_ERR(old.bh)) 3840 return PTR_ERR(old.bh); 3841 3842 /* 3843 * Check for inode number is _not_ due to possible IO errors. 3844 * We might rmdir the source, keep it as pwd of some process 3845 * and merrily kill the link to whatever was created under the 3846 * same name. Goodbye sticky bit ;-< 3847 */ 3848 retval = -ENOENT; 3849 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino) 3850 goto release_bh; 3851 3852 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, 3853 &new.de, &new.inlined); 3854 if (IS_ERR(new.bh)) { 3855 retval = PTR_ERR(new.bh); 3856 new.bh = NULL; 3857 goto release_bh; 3858 } 3859 if (new.bh) { 3860 if (!new.inode) { 3861 brelse(new.bh); 3862 new.bh = NULL; 3863 } 3864 } 3865 if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC)) 3866 ext4_alloc_da_blocks(old.inode); 3867 3868 credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + 3869 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2); 3870 if (!(flags & RENAME_WHITEOUT)) { 3871 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits); 3872 if (IS_ERR(handle)) { 3873 retval = PTR_ERR(handle); 3874 goto release_bh; 3875 } 3876 } else { 3877 whiteout = ext4_whiteout_for_rename(idmap, &old, credits, &handle); 3878 if (IS_ERR(whiteout)) { 3879 retval = PTR_ERR(whiteout); 3880 goto release_bh; 3881 } 3882 } 3883 3884 old_file_type = old.de->file_type; 3885 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir)) 3886 ext4_handle_sync(handle); 3887 3888 if (S_ISDIR(old.inode->i_mode)) { 3889 if (new.inode) { 3890 retval = -ENOTEMPTY; 3891 if (!ext4_empty_dir(new.inode)) 3892 goto end_rename; 3893 } else { 3894 retval = -EMLINK; 3895 if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir)) 3896 goto end_rename; 3897 } 3898 retval = ext4_rename_dir_prepare(handle, &old); 3899 if (retval) 3900 goto end_rename; 3901 } 3902 /* 3903 * If we're renaming a file within an inline_data dir and adding or 3904 * setting the new dirent causes a conversion from inline_data to 3905 * extents/blockmap, we need to force the dirent delete code to 3906 * re-read the directory, or else we end up trying to delete a dirent 3907 * from what is now the extent tree root (or a block map). 3908 */ 3909 force_reread = (new.dir->i_ino == old.dir->i_ino && 3910 ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA)); 3911 3912 if (whiteout) { 3913 /* 3914 * Do this before adding a new entry, so the old entry is sure 3915 * to be still pointing to the valid old entry. 3916 */ 3917 retval = ext4_setent(handle, &old, whiteout->i_ino, 3918 EXT4_FT_CHRDEV); 3919 if (retval) 3920 goto end_rename; 3921 retval = ext4_mark_inode_dirty(handle, whiteout); 3922 if (unlikely(retval)) 3923 goto end_rename; 3924 3925 } 3926 if (!new.bh) { 3927 retval = ext4_add_entry(handle, new.dentry, old.inode); 3928 if (retval) 3929 goto end_rename; 3930 } else { 3931 retval = ext4_setent(handle, &new, 3932 old.inode->i_ino, old_file_type); 3933 if (retval) 3934 goto end_rename; 3935 } 3936 if (force_reread) 3937 force_reread = !ext4_test_inode_flag(new.dir, 3938 EXT4_INODE_INLINE_DATA); 3939 3940 /* 3941 * Like most other Unix systems, set the ctime for inodes on a 3942 * rename. 3943 */ 3944 old.inode->i_ctime = current_time(old.inode); 3945 retval = ext4_mark_inode_dirty(handle, old.inode); 3946 if (unlikely(retval)) 3947 goto end_rename; 3948 3949 if (!whiteout) { 3950 /* 3951 * ok, that's it 3952 */ 3953 ext4_rename_delete(handle, &old, force_reread); 3954 } 3955 3956 if (new.inode) { 3957 ext4_dec_count(new.inode); 3958 new.inode->i_ctime = current_time(new.inode); 3959 } 3960 old.dir->i_ctime = old.dir->i_mtime = current_time(old.dir); 3961 ext4_update_dx_flag(old.dir); 3962 if (old.dir_bh) { 3963 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); 3964 if (retval) 3965 goto end_rename; 3966 3967 ext4_dec_count(old.dir); 3968 if (new.inode) { 3969 /* checked ext4_empty_dir above, can't have another 3970 * parent, ext4_dec_count() won't work for many-linked 3971 * dirs */ 3972 clear_nlink(new.inode); 3973 } else { 3974 ext4_inc_count(new.dir); 3975 ext4_update_dx_flag(new.dir); 3976 retval = ext4_mark_inode_dirty(handle, new.dir); 3977 if (unlikely(retval)) 3978 goto end_rename; 3979 } 3980 } 3981 retval = ext4_mark_inode_dirty(handle, old.dir); 3982 if (unlikely(retval)) 3983 goto end_rename; 3984 3985 if (S_ISDIR(old.inode->i_mode)) { 3986 /* 3987 * We disable fast commits here that's because the 3988 * replay code is not yet capable of changing dot dot 3989 * dirents in directories. 3990 */ 3991 ext4_fc_mark_ineligible(old.inode->i_sb, 3992 EXT4_FC_REASON_RENAME_DIR, handle); 3993 } else { 3994 struct super_block *sb = old.inode->i_sb; 3995 3996 if (new.inode) 3997 ext4_fc_track_unlink(handle, new.dentry); 3998 if (test_opt2(sb, JOURNAL_FAST_COMMIT) && 3999 !(EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY) && 4000 !(ext4_test_mount_flag(sb, EXT4_MF_FC_INELIGIBLE))) { 4001 __ext4_fc_track_link(handle, old.inode, new.dentry); 4002 __ext4_fc_track_unlink(handle, old.inode, old.dentry); 4003 if (whiteout) 4004 __ext4_fc_track_create(handle, whiteout, 4005 old.dentry); 4006 } 4007 } 4008 4009 if (new.inode) { 4010 retval = ext4_mark_inode_dirty(handle, new.inode); 4011 if (unlikely(retval)) 4012 goto end_rename; 4013 if (!new.inode->i_nlink) 4014 ext4_orphan_add(handle, new.inode); 4015 } 4016 retval = 0; 4017 4018 end_rename: 4019 if (whiteout) { 4020 if (retval) { 4021 ext4_resetent(handle, &old, 4022 old.inode->i_ino, old_file_type); 4023 drop_nlink(whiteout); 4024 ext4_orphan_add(handle, whiteout); 4025 } 4026 unlock_new_inode(whiteout); 4027 ext4_journal_stop(handle); 4028 iput(whiteout); 4029 } else { 4030 ext4_journal_stop(handle); 4031 } 4032 release_bh: 4033 brelse(old.dir_bh); 4034 brelse(old.bh); 4035 brelse(new.bh); 4036 4037 return retval; 4038 } 4039 4040 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry, 4041 struct inode *new_dir, struct dentry *new_dentry) 4042 { 4043 handle_t *handle = NULL; 4044 struct ext4_renament old = { 4045 .dir = old_dir, 4046 .dentry = old_dentry, 4047 .inode = d_inode(old_dentry), 4048 }; 4049 struct ext4_renament new = { 4050 .dir = new_dir, 4051 .dentry = new_dentry, 4052 .inode = d_inode(new_dentry), 4053 }; 4054 u8 new_file_type; 4055 int retval; 4056 struct timespec64 ctime; 4057 4058 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) && 4059 !projid_eq(EXT4_I(new_dir)->i_projid, 4060 EXT4_I(old_dentry->d_inode)->i_projid)) || 4061 (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) && 4062 !projid_eq(EXT4_I(old_dir)->i_projid, 4063 EXT4_I(new_dentry->d_inode)->i_projid))) 4064 return -EXDEV; 4065 4066 retval = dquot_initialize(old.dir); 4067 if (retval) 4068 return retval; 4069 retval = dquot_initialize(new.dir); 4070 if (retval) 4071 return retval; 4072 4073 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, 4074 &old.de, &old.inlined); 4075 if (IS_ERR(old.bh)) 4076 return PTR_ERR(old.bh); 4077 /* 4078 * Check for inode number is _not_ due to possible IO errors. 4079 * We might rmdir the source, keep it as pwd of some process 4080 * and merrily kill the link to whatever was created under the 4081 * same name. Goodbye sticky bit ;-< 4082 */ 4083 retval = -ENOENT; 4084 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino) 4085 goto end_rename; 4086 4087 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, 4088 &new.de, &new.inlined); 4089 if (IS_ERR(new.bh)) { 4090 retval = PTR_ERR(new.bh); 4091 new.bh = NULL; 4092 goto end_rename; 4093 } 4094 4095 /* RENAME_EXCHANGE case: old *and* new must both exist */ 4096 if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino) 4097 goto end_rename; 4098 4099 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, 4100 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + 4101 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2)); 4102 if (IS_ERR(handle)) { 4103 retval = PTR_ERR(handle); 4104 handle = NULL; 4105 goto end_rename; 4106 } 4107 4108 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir)) 4109 ext4_handle_sync(handle); 4110 4111 if (S_ISDIR(old.inode->i_mode)) { 4112 old.is_dir = true; 4113 retval = ext4_rename_dir_prepare(handle, &old); 4114 if (retval) 4115 goto end_rename; 4116 } 4117 if (S_ISDIR(new.inode->i_mode)) { 4118 new.is_dir = true; 4119 retval = ext4_rename_dir_prepare(handle, &new); 4120 if (retval) 4121 goto end_rename; 4122 } 4123 4124 /* 4125 * Other than the special case of overwriting a directory, parents' 4126 * nlink only needs to be modified if this is a cross directory rename. 4127 */ 4128 if (old.dir != new.dir && old.is_dir != new.is_dir) { 4129 old.dir_nlink_delta = old.is_dir ? -1 : 1; 4130 new.dir_nlink_delta = -old.dir_nlink_delta; 4131 retval = -EMLINK; 4132 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) || 4133 (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir))) 4134 goto end_rename; 4135 } 4136 4137 new_file_type = new.de->file_type; 4138 retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type); 4139 if (retval) 4140 goto end_rename; 4141 4142 retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type); 4143 if (retval) 4144 goto end_rename; 4145 4146 /* 4147 * Like most other Unix systems, set the ctime for inodes on a 4148 * rename. 4149 */ 4150 ctime = current_time(old.inode); 4151 old.inode->i_ctime = ctime; 4152 new.inode->i_ctime = ctime; 4153 retval = ext4_mark_inode_dirty(handle, old.inode); 4154 if (unlikely(retval)) 4155 goto end_rename; 4156 retval = ext4_mark_inode_dirty(handle, new.inode); 4157 if (unlikely(retval)) 4158 goto end_rename; 4159 ext4_fc_mark_ineligible(new.inode->i_sb, 4160 EXT4_FC_REASON_CROSS_RENAME, handle); 4161 if (old.dir_bh) { 4162 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); 4163 if (retval) 4164 goto end_rename; 4165 } 4166 if (new.dir_bh) { 4167 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino); 4168 if (retval) 4169 goto end_rename; 4170 } 4171 ext4_update_dir_count(handle, &old); 4172 ext4_update_dir_count(handle, &new); 4173 retval = 0; 4174 4175 end_rename: 4176 brelse(old.dir_bh); 4177 brelse(new.dir_bh); 4178 brelse(old.bh); 4179 brelse(new.bh); 4180 if (handle) 4181 ext4_journal_stop(handle); 4182 return retval; 4183 } 4184 4185 static int ext4_rename2(struct mnt_idmap *idmap, 4186 struct inode *old_dir, struct dentry *old_dentry, 4187 struct inode *new_dir, struct dentry *new_dentry, 4188 unsigned int flags) 4189 { 4190 int err; 4191 4192 if (unlikely(ext4_forced_shutdown(EXT4_SB(old_dir->i_sb)))) 4193 return -EIO; 4194 4195 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT)) 4196 return -EINVAL; 4197 4198 err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry, 4199 flags); 4200 if (err) 4201 return err; 4202 4203 if (flags & RENAME_EXCHANGE) { 4204 return ext4_cross_rename(old_dir, old_dentry, 4205 new_dir, new_dentry); 4206 } 4207 4208 return ext4_rename(idmap, old_dir, old_dentry, new_dir, new_dentry, flags); 4209 } 4210 4211 /* 4212 * directories can handle most operations... 4213 */ 4214 const struct inode_operations ext4_dir_inode_operations = { 4215 .create = ext4_create, 4216 .lookup = ext4_lookup, 4217 .link = ext4_link, 4218 .unlink = ext4_unlink, 4219 .symlink = ext4_symlink, 4220 .mkdir = ext4_mkdir, 4221 .rmdir = ext4_rmdir, 4222 .mknod = ext4_mknod, 4223 .tmpfile = ext4_tmpfile, 4224 .rename = ext4_rename2, 4225 .setattr = ext4_setattr, 4226 .getattr = ext4_getattr, 4227 .listxattr = ext4_listxattr, 4228 .get_inode_acl = ext4_get_acl, 4229 .set_acl = ext4_set_acl, 4230 .fiemap = ext4_fiemap, 4231 .fileattr_get = ext4_fileattr_get, 4232 .fileattr_set = ext4_fileattr_set, 4233 }; 4234 4235 const struct inode_operations ext4_special_inode_operations = { 4236 .setattr = ext4_setattr, 4237 .getattr = ext4_getattr, 4238 .listxattr = ext4_listxattr, 4239 .get_inode_acl = ext4_get_acl, 4240 .set_acl = ext4_set_acl, 4241 }; 4242