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