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 int blocksize = EXT4_BLOCK_SIZE(inode->i_sb); 347 348 #ifdef PARANOID 349 struct ext4_dir_entry *d, *top; 350 351 d = (struct ext4_dir_entry *)bh->b_data; 352 top = (struct ext4_dir_entry *)(bh->b_data + 353 (blocksize - sizeof(struct ext4_dir_entry_tail))); 354 while (d < top && ext4_rec_len_from_disk(d->rec_len, blocksize)) 355 d = (struct ext4_dir_entry *)(((void *)d) + 356 ext4_rec_len_from_disk(d->rec_len, blocksize)); 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 (ext4_rec_len_from_disk(t->det_rec_len, blocksize) != 368 sizeof(struct ext4_dir_entry_tail)) || 369 t->det_reserved_zero2 || 370 t->det_reserved_ft != EXT4_FT_DIR_CSUM) 371 return NULL; 372 373 return t; 374 } 375 376 static __le32 ext4_dirblock_csum(struct inode *inode, void *dirent, int size) 377 { 378 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 379 struct ext4_inode_info *ei = EXT4_I(inode); 380 __u32 csum; 381 382 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size); 383 return cpu_to_le32(csum); 384 } 385 386 #define warn_no_space_for_csum(inode) \ 387 __warn_no_space_for_csum((inode), __func__, __LINE__) 388 389 static void __warn_no_space_for_csum(struct inode *inode, const char *func, 390 unsigned int line) 391 { 392 __ext4_warning_inode(inode, func, line, 393 "No space for directory leaf checksum. Please run e2fsck -D."); 394 } 395 396 int ext4_dirblock_csum_verify(struct inode *inode, struct buffer_head *bh) 397 { 398 struct ext4_dir_entry_tail *t; 399 400 if (!ext4_has_metadata_csum(inode->i_sb)) 401 return 1; 402 403 t = get_dirent_tail(inode, bh); 404 if (!t) { 405 warn_no_space_for_csum(inode); 406 return 0; 407 } 408 409 if (t->det_checksum != ext4_dirblock_csum(inode, bh->b_data, 410 (char *)t - bh->b_data)) 411 return 0; 412 413 return 1; 414 } 415 416 static void ext4_dirblock_csum_set(struct inode *inode, 417 struct buffer_head *bh) 418 { 419 struct ext4_dir_entry_tail *t; 420 421 if (!ext4_has_metadata_csum(inode->i_sb)) 422 return; 423 424 t = get_dirent_tail(inode, bh); 425 if (!t) { 426 warn_no_space_for_csum(inode); 427 return; 428 } 429 430 t->det_checksum = ext4_dirblock_csum(inode, bh->b_data, 431 (char *)t - bh->b_data); 432 } 433 434 int ext4_handle_dirty_dirblock(handle_t *handle, 435 struct inode *inode, 436 struct buffer_head *bh) 437 { 438 ext4_dirblock_csum_set(inode, bh); 439 return ext4_handle_dirty_metadata(handle, inode, bh); 440 } 441 442 static struct dx_countlimit *get_dx_countlimit(struct inode *inode, 443 struct ext4_dir_entry *dirent, 444 int *offset) 445 { 446 struct ext4_dir_entry *dp; 447 struct dx_root_info *root; 448 int count_offset; 449 int blocksize = EXT4_BLOCK_SIZE(inode->i_sb); 450 unsigned int rlen = ext4_rec_len_from_disk(dirent->rec_len, blocksize); 451 452 if (rlen == blocksize) 453 count_offset = 8; 454 else if (rlen == 12) { 455 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12); 456 if (ext4_rec_len_from_disk(dp->rec_len, blocksize) != blocksize - 12) 457 return NULL; 458 root = (struct dx_root_info *)(((void *)dp + 12)); 459 if (root->reserved_zero || 460 root->info_length != sizeof(struct dx_root_info)) 461 return NULL; 462 count_offset = 32; 463 } else 464 return NULL; 465 466 if (offset) 467 *offset = count_offset; 468 return (struct dx_countlimit *)(((void *)dirent) + count_offset); 469 } 470 471 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent, 472 int count_offset, int count, struct dx_tail *t) 473 { 474 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 475 struct ext4_inode_info *ei = EXT4_I(inode); 476 __u32 csum; 477 int size; 478 __u32 dummy_csum = 0; 479 int offset = offsetof(struct dx_tail, dt_checksum); 480 481 size = count_offset + (count * sizeof(struct dx_entry)); 482 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size); 483 csum = ext4_chksum(sbi, csum, (__u8 *)t, offset); 484 csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum)); 485 486 return cpu_to_le32(csum); 487 } 488 489 static int ext4_dx_csum_verify(struct inode *inode, 490 struct ext4_dir_entry *dirent) 491 { 492 struct dx_countlimit *c; 493 struct dx_tail *t; 494 int count_offset, limit, count; 495 496 if (!ext4_has_metadata_csum(inode->i_sb)) 497 return 1; 498 499 c = get_dx_countlimit(inode, dirent, &count_offset); 500 if (!c) { 501 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D."); 502 return 0; 503 } 504 limit = le16_to_cpu(c->limit); 505 count = le16_to_cpu(c->count); 506 if (count_offset + (limit * sizeof(struct dx_entry)) > 507 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) { 508 warn_no_space_for_csum(inode); 509 return 0; 510 } 511 t = (struct dx_tail *)(((struct dx_entry *)c) + limit); 512 513 if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset, 514 count, t)) 515 return 0; 516 return 1; 517 } 518 519 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent) 520 { 521 struct dx_countlimit *c; 522 struct dx_tail *t; 523 int count_offset, limit, count; 524 525 if (!ext4_has_metadata_csum(inode->i_sb)) 526 return; 527 528 c = get_dx_countlimit(inode, dirent, &count_offset); 529 if (!c) { 530 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D."); 531 return; 532 } 533 limit = le16_to_cpu(c->limit); 534 count = le16_to_cpu(c->count); 535 if (count_offset + (limit * sizeof(struct dx_entry)) > 536 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) { 537 warn_no_space_for_csum(inode); 538 return; 539 } 540 t = (struct dx_tail *)(((struct dx_entry *)c) + limit); 541 542 t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t); 543 } 544 545 static inline int ext4_handle_dirty_dx_node(handle_t *handle, 546 struct inode *inode, 547 struct buffer_head *bh) 548 { 549 ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data); 550 return ext4_handle_dirty_metadata(handle, inode, bh); 551 } 552 553 /* 554 * p is at least 6 bytes before the end of page 555 */ 556 static inline struct ext4_dir_entry_2 * 557 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize) 558 { 559 return (struct ext4_dir_entry_2 *)((char *)p + 560 ext4_rec_len_from_disk(p->rec_len, blocksize)); 561 } 562 563 /* 564 * Future: use high four bits of block for coalesce-on-delete flags 565 * Mask them off for now. 566 */ 567 568 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry) 569 { 570 return le32_to_cpu(entry->block) & 0x0fffffff; 571 } 572 573 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value) 574 { 575 entry->block = cpu_to_le32(value); 576 } 577 578 static inline unsigned dx_get_hash(struct dx_entry *entry) 579 { 580 return le32_to_cpu(entry->hash); 581 } 582 583 static inline void dx_set_hash(struct dx_entry *entry, unsigned value) 584 { 585 entry->hash = cpu_to_le32(value); 586 } 587 588 static inline unsigned dx_get_count(struct dx_entry *entries) 589 { 590 return le16_to_cpu(((struct dx_countlimit *) entries)->count); 591 } 592 593 static inline unsigned dx_get_limit(struct dx_entry *entries) 594 { 595 return le16_to_cpu(((struct dx_countlimit *) entries)->limit); 596 } 597 598 static inline void dx_set_count(struct dx_entry *entries, unsigned value) 599 { 600 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value); 601 } 602 603 static inline void dx_set_limit(struct dx_entry *entries, unsigned value) 604 { 605 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value); 606 } 607 608 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize) 609 { 610 unsigned int entry_space = dir->i_sb->s_blocksize - 611 ext4_dir_rec_len(1, NULL) - 612 ext4_dir_rec_len(2, NULL) - infosize; 613 614 if (ext4_has_metadata_csum(dir->i_sb)) 615 entry_space -= sizeof(struct dx_tail); 616 return entry_space / sizeof(struct dx_entry); 617 } 618 619 static inline unsigned dx_node_limit(struct inode *dir) 620 { 621 unsigned int entry_space = dir->i_sb->s_blocksize - 622 ext4_dir_rec_len(0, dir); 623 624 if (ext4_has_metadata_csum(dir->i_sb)) 625 entry_space -= sizeof(struct dx_tail); 626 return entry_space / sizeof(struct dx_entry); 627 } 628 629 /* 630 * Debug 631 */ 632 #ifdef DX_DEBUG 633 static void dx_show_index(char * label, struct dx_entry *entries) 634 { 635 int i, n = dx_get_count (entries); 636 printk(KERN_DEBUG "%s index", label); 637 for (i = 0; i < n; i++) { 638 printk(KERN_CONT " %x->%lu", 639 i ? dx_get_hash(entries + i) : 0, 640 (unsigned long)dx_get_block(entries + i)); 641 } 642 printk(KERN_CONT "\n"); 643 } 644 645 struct stats 646 { 647 unsigned names; 648 unsigned space; 649 unsigned bcount; 650 }; 651 652 static struct stats dx_show_leaf(struct inode *dir, 653 struct dx_hash_info *hinfo, 654 struct ext4_dir_entry_2 *de, 655 int size, int show_names) 656 { 657 unsigned names = 0, space = 0; 658 char *base = (char *) de; 659 struct dx_hash_info h = *hinfo; 660 661 printk("names: "); 662 while ((char *) de < base + size) 663 { 664 if (de->inode) 665 { 666 if (show_names) 667 { 668 #ifdef CONFIG_FS_ENCRYPTION 669 int len; 670 char *name; 671 struct fscrypt_str fname_crypto_str = 672 FSTR_INIT(NULL, 0); 673 int res = 0; 674 675 name = de->name; 676 len = de->name_len; 677 if (!IS_ENCRYPTED(dir)) { 678 /* Directory is not encrypted */ 679 (void) ext4fs_dirhash(dir, de->name, 680 de->name_len, &h); 681 printk("%*.s:(U)%x.%u ", len, 682 name, h.hash, 683 (unsigned) ((char *) de 684 - base)); 685 } else { 686 struct fscrypt_str de_name = 687 FSTR_INIT(name, len); 688 689 /* Directory is encrypted */ 690 res = fscrypt_fname_alloc_buffer( 691 len, &fname_crypto_str); 692 if (res) 693 printk(KERN_WARNING "Error " 694 "allocating crypto " 695 "buffer--skipping " 696 "crypto\n"); 697 res = fscrypt_fname_disk_to_usr(dir, 698 0, 0, &de_name, 699 &fname_crypto_str); 700 if (res) { 701 printk(KERN_WARNING "Error " 702 "converting filename " 703 "from disk to usr" 704 "\n"); 705 name = "??"; 706 len = 2; 707 } else { 708 name = fname_crypto_str.name; 709 len = fname_crypto_str.len; 710 } 711 if (IS_CASEFOLDED(dir)) 712 h.hash = EXT4_DIRENT_HASH(de); 713 else 714 (void) ext4fs_dirhash(dir, 715 de->name, 716 de->name_len, &h); 717 printk("%*.s:(E)%x.%u ", len, name, 718 h.hash, (unsigned) ((char *) de 719 - base)); 720 fscrypt_fname_free_buffer( 721 &fname_crypto_str); 722 } 723 #else 724 int len = de->name_len; 725 char *name = de->name; 726 (void) ext4fs_dirhash(dir, de->name, 727 de->name_len, &h); 728 printk("%*.s:%x.%u ", len, name, h.hash, 729 (unsigned) ((char *) de - base)); 730 #endif 731 } 732 space += ext4_dir_rec_len(de->name_len, dir); 733 names++; 734 } 735 de = ext4_next_entry(de, size); 736 } 737 printk(KERN_CONT "(%i)\n", names); 738 return (struct stats) { names, space, 1 }; 739 } 740 741 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir, 742 struct dx_entry *entries, int levels) 743 { 744 unsigned blocksize = dir->i_sb->s_blocksize; 745 unsigned count = dx_get_count(entries), names = 0, space = 0, i; 746 unsigned bcount = 0; 747 struct buffer_head *bh; 748 printk("%i indexed blocks...\n", count); 749 for (i = 0; i < count; i++, entries++) 750 { 751 ext4_lblk_t block = dx_get_block(entries); 752 ext4_lblk_t hash = i ? dx_get_hash(entries): 0; 753 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash; 754 struct stats stats; 755 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range); 756 bh = ext4_bread(NULL,dir, block, 0); 757 if (!bh || IS_ERR(bh)) 758 continue; 759 stats = levels? 760 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1): 761 dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) 762 bh->b_data, blocksize, 0); 763 names += stats.names; 764 space += stats.space; 765 bcount += stats.bcount; 766 brelse(bh); 767 } 768 if (bcount) 769 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n", 770 levels ? "" : " ", names, space/bcount, 771 (space/bcount)*100/blocksize); 772 return (struct stats) { names, space, bcount}; 773 } 774 775 /* 776 * Linear search cross check 777 */ 778 static inline void htree_rep_invariant_check(struct dx_entry *at, 779 struct dx_entry *target, 780 u32 hash, unsigned int n) 781 { 782 while (n--) { 783 dxtrace(printk(KERN_CONT ",")); 784 if (dx_get_hash(++at) > hash) { 785 at--; 786 break; 787 } 788 } 789 ASSERT(at == target - 1); 790 } 791 #else /* DX_DEBUG */ 792 static inline void htree_rep_invariant_check(struct dx_entry *at, 793 struct dx_entry *target, 794 u32 hash, unsigned int n) 795 { 796 } 797 #endif /* DX_DEBUG */ 798 799 /* 800 * Probe for a directory leaf block to search. 801 * 802 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format 803 * error in the directory index, and the caller should fall back to 804 * searching the directory normally. The callers of dx_probe **MUST** 805 * check for this error code, and make sure it never gets reflected 806 * back to userspace. 807 */ 808 static struct dx_frame * 809 dx_probe(struct ext4_filename *fname, struct inode *dir, 810 struct dx_hash_info *hinfo, struct dx_frame *frame_in) 811 { 812 unsigned count, indirect, level, i; 813 struct dx_entry *at, *entries, *p, *q, *m; 814 struct dx_root *root; 815 struct dx_frame *frame = frame_in; 816 struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR); 817 u32 hash; 818 ext4_lblk_t block; 819 ext4_lblk_t blocks[EXT4_HTREE_LEVEL]; 820 821 memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0])); 822 frame->bh = ext4_read_dirblock(dir, 0, INDEX); 823 if (IS_ERR(frame->bh)) 824 return (struct dx_frame *) frame->bh; 825 826 root = (struct dx_root *) frame->bh->b_data; 827 if (root->info.hash_version != DX_HASH_TEA && 828 root->info.hash_version != DX_HASH_HALF_MD4 && 829 root->info.hash_version != DX_HASH_LEGACY && 830 root->info.hash_version != DX_HASH_SIPHASH) { 831 ext4_warning_inode(dir, "Unrecognised inode hash code %u", 832 root->info.hash_version); 833 goto fail; 834 } 835 if (ext4_hash_in_dirent(dir)) { 836 if (root->info.hash_version != DX_HASH_SIPHASH) { 837 ext4_warning_inode(dir, 838 "Hash in dirent, but hash is not SIPHASH"); 839 goto fail; 840 } 841 } else { 842 if (root->info.hash_version == DX_HASH_SIPHASH) { 843 ext4_warning_inode(dir, 844 "Hash code is SIPHASH, but hash not in dirent"); 845 goto fail; 846 } 847 } 848 if (fname) 849 hinfo = &fname->hinfo; 850 hinfo->hash_version = root->info.hash_version; 851 if (hinfo->hash_version <= DX_HASH_TEA) 852 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; 853 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed; 854 /* hash is already computed for encrypted casefolded directory */ 855 if (fname && fname_name(fname) && 856 !(IS_ENCRYPTED(dir) && IS_CASEFOLDED(dir))) { 857 int ret = ext4fs_dirhash(dir, fname_name(fname), 858 fname_len(fname), hinfo); 859 if (ret < 0) { 860 ret_err = ERR_PTR(ret); 861 goto fail; 862 } 863 } 864 hash = hinfo->hash; 865 866 if (root->info.unused_flags & 1) { 867 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x", 868 root->info.unused_flags); 869 goto fail; 870 } 871 872 indirect = root->info.indirect_levels; 873 if (indirect >= ext4_dir_htree_level(dir->i_sb)) { 874 ext4_warning(dir->i_sb, 875 "Directory (ino: %lu) htree depth %#06x exceed" 876 "supported value", dir->i_ino, 877 ext4_dir_htree_level(dir->i_sb)); 878 if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) { 879 ext4_warning(dir->i_sb, "Enable large directory " 880 "feature to access it"); 881 } 882 goto fail; 883 } 884 885 entries = (struct dx_entry *)(((char *)&root->info) + 886 root->info.info_length); 887 888 if (dx_get_limit(entries) != dx_root_limit(dir, 889 root->info.info_length)) { 890 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u", 891 dx_get_limit(entries), 892 dx_root_limit(dir, root->info.info_length)); 893 goto fail; 894 } 895 896 dxtrace(printk("Look up %x", hash)); 897 level = 0; 898 blocks[0] = 0; 899 while (1) { 900 count = dx_get_count(entries); 901 if (!count || count > dx_get_limit(entries)) { 902 ext4_warning_inode(dir, 903 "dx entry: count %u beyond limit %u", 904 count, dx_get_limit(entries)); 905 goto fail; 906 } 907 908 p = entries + 1; 909 q = entries + count - 1; 910 while (p <= q) { 911 m = p + (q - p) / 2; 912 dxtrace(printk(KERN_CONT ".")); 913 if (dx_get_hash(m) > hash) 914 q = m - 1; 915 else 916 p = m + 1; 917 } 918 919 htree_rep_invariant_check(entries, p, hash, count - 1); 920 921 at = p - 1; 922 dxtrace(printk(KERN_CONT " %x->%u\n", 923 at == entries ? 0 : dx_get_hash(at), 924 dx_get_block(at))); 925 frame->entries = entries; 926 frame->at = at; 927 928 block = dx_get_block(at); 929 for (i = 0; i <= level; i++) { 930 if (blocks[i] == block) { 931 ext4_warning_inode(dir, 932 "dx entry: tree cycle block %u points back to block %u", 933 blocks[level], block); 934 goto fail; 935 } 936 } 937 if (++level > indirect) 938 return frame; 939 blocks[level] = block; 940 frame++; 941 frame->bh = ext4_read_dirblock(dir, block, INDEX); 942 if (IS_ERR(frame->bh)) { 943 ret_err = (struct dx_frame *) frame->bh; 944 frame->bh = NULL; 945 goto fail; 946 } 947 948 entries = ((struct dx_node *) frame->bh->b_data)->entries; 949 950 if (dx_get_limit(entries) != dx_node_limit(dir)) { 951 ext4_warning_inode(dir, 952 "dx entry: limit %u != node limit %u", 953 dx_get_limit(entries), dx_node_limit(dir)); 954 goto fail; 955 } 956 } 957 fail: 958 while (frame >= frame_in) { 959 brelse(frame->bh); 960 frame--; 961 } 962 963 if (ret_err == ERR_PTR(ERR_BAD_DX_DIR)) 964 ext4_warning_inode(dir, 965 "Corrupt directory, running e2fsck is recommended"); 966 return ret_err; 967 } 968 969 static void dx_release(struct dx_frame *frames) 970 { 971 struct dx_root_info *info; 972 int i; 973 unsigned int indirect_levels; 974 975 if (frames[0].bh == NULL) 976 return; 977 978 info = &((struct dx_root *)frames[0].bh->b_data)->info; 979 /* save local copy, "info" may be freed after brelse() */ 980 indirect_levels = info->indirect_levels; 981 for (i = 0; i <= indirect_levels; i++) { 982 if (frames[i].bh == NULL) 983 break; 984 brelse(frames[i].bh); 985 frames[i].bh = NULL; 986 } 987 } 988 989 /* 990 * This function increments the frame pointer to search the next leaf 991 * block, and reads in the necessary intervening nodes if the search 992 * should be necessary. Whether or not the search is necessary is 993 * controlled by the hash parameter. If the hash value is even, then 994 * the search is only continued if the next block starts with that 995 * hash value. This is used if we are searching for a specific file. 996 * 997 * If the hash value is HASH_NB_ALWAYS, then always go to the next block. 998 * 999 * This function returns 1 if the caller should continue to search, 1000 * or 0 if it should not. If there is an error reading one of the 1001 * index blocks, it will a negative error code. 1002 * 1003 * If start_hash is non-null, it will be filled in with the starting 1004 * hash of the next page. 1005 */ 1006 static int ext4_htree_next_block(struct inode *dir, __u32 hash, 1007 struct dx_frame *frame, 1008 struct dx_frame *frames, 1009 __u32 *start_hash) 1010 { 1011 struct dx_frame *p; 1012 struct buffer_head *bh; 1013 int num_frames = 0; 1014 __u32 bhash; 1015 1016 p = frame; 1017 /* 1018 * Find the next leaf page by incrementing the frame pointer. 1019 * If we run out of entries in the interior node, loop around and 1020 * increment pointer in the parent node. When we break out of 1021 * this loop, num_frames indicates the number of interior 1022 * nodes need to be read. 1023 */ 1024 while (1) { 1025 if (++(p->at) < p->entries + dx_get_count(p->entries)) 1026 break; 1027 if (p == frames) 1028 return 0; 1029 num_frames++; 1030 p--; 1031 } 1032 1033 /* 1034 * If the hash is 1, then continue only if the next page has a 1035 * continuation hash of any value. This is used for readdir 1036 * handling. Otherwise, check to see if the hash matches the 1037 * desired continuation hash. If it doesn't, return since 1038 * there's no point to read in the successive index pages. 1039 */ 1040 bhash = dx_get_hash(p->at); 1041 if (start_hash) 1042 *start_hash = bhash; 1043 if ((hash & 1) == 0) { 1044 if ((bhash & ~1) != hash) 1045 return 0; 1046 } 1047 /* 1048 * If the hash is HASH_NB_ALWAYS, we always go to the next 1049 * block so no check is necessary 1050 */ 1051 while (num_frames--) { 1052 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX); 1053 if (IS_ERR(bh)) 1054 return PTR_ERR(bh); 1055 p++; 1056 brelse(p->bh); 1057 p->bh = bh; 1058 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries; 1059 } 1060 return 1; 1061 } 1062 1063 1064 /* 1065 * This function fills a red-black tree with information from a 1066 * directory block. It returns the number directory entries loaded 1067 * into the tree. If there is an error it is returned in err. 1068 */ 1069 static int htree_dirblock_to_tree(struct file *dir_file, 1070 struct inode *dir, ext4_lblk_t block, 1071 struct dx_hash_info *hinfo, 1072 __u32 start_hash, __u32 start_minor_hash) 1073 { 1074 struct buffer_head *bh; 1075 struct ext4_dir_entry_2 *de, *top; 1076 int err = 0, count = 0; 1077 struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str; 1078 int csum = ext4_has_metadata_csum(dir->i_sb); 1079 1080 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n", 1081 (unsigned long)block)); 1082 bh = ext4_read_dirblock(dir, block, DIRENT_HTREE); 1083 if (IS_ERR(bh)) 1084 return PTR_ERR(bh); 1085 1086 de = (struct ext4_dir_entry_2 *) bh->b_data; 1087 /* csum entries are not larger in the casefolded encrypted case */ 1088 top = (struct ext4_dir_entry_2 *) ((char *) de + 1089 dir->i_sb->s_blocksize - 1090 ext4_dir_rec_len(0, 1091 csum ? NULL : dir)); 1092 /* Check if the directory is encrypted */ 1093 if (IS_ENCRYPTED(dir)) { 1094 err = fscrypt_prepare_readdir(dir); 1095 if (err < 0) { 1096 brelse(bh); 1097 return err; 1098 } 1099 err = fscrypt_fname_alloc_buffer(EXT4_NAME_LEN, 1100 &fname_crypto_str); 1101 if (err < 0) { 1102 brelse(bh); 1103 return err; 1104 } 1105 } 1106 1107 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) { 1108 if (ext4_check_dir_entry(dir, NULL, de, bh, 1109 bh->b_data, bh->b_size, 1110 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb)) 1111 + ((char *)de - bh->b_data))) { 1112 /* silently ignore the rest of the block */ 1113 break; 1114 } 1115 if (ext4_hash_in_dirent(dir)) { 1116 if (de->name_len && de->inode) { 1117 hinfo->hash = EXT4_DIRENT_HASH(de); 1118 hinfo->minor_hash = EXT4_DIRENT_MINOR_HASH(de); 1119 } else { 1120 hinfo->hash = 0; 1121 hinfo->minor_hash = 0; 1122 } 1123 } else { 1124 err = ext4fs_dirhash(dir, de->name, 1125 de->name_len, hinfo); 1126 if (err < 0) { 1127 count = err; 1128 goto errout; 1129 } 1130 } 1131 if ((hinfo->hash < start_hash) || 1132 ((hinfo->hash == start_hash) && 1133 (hinfo->minor_hash < start_minor_hash))) 1134 continue; 1135 if (de->inode == 0) 1136 continue; 1137 if (!IS_ENCRYPTED(dir)) { 1138 tmp_str.name = de->name; 1139 tmp_str.len = de->name_len; 1140 err = ext4_htree_store_dirent(dir_file, 1141 hinfo->hash, hinfo->minor_hash, de, 1142 &tmp_str); 1143 } else { 1144 int save_len = fname_crypto_str.len; 1145 struct fscrypt_str de_name = FSTR_INIT(de->name, 1146 de->name_len); 1147 1148 /* Directory is encrypted */ 1149 err = fscrypt_fname_disk_to_usr(dir, hinfo->hash, 1150 hinfo->minor_hash, &de_name, 1151 &fname_crypto_str); 1152 if (err) { 1153 count = err; 1154 goto errout; 1155 } 1156 err = ext4_htree_store_dirent(dir_file, 1157 hinfo->hash, hinfo->minor_hash, de, 1158 &fname_crypto_str); 1159 fname_crypto_str.len = save_len; 1160 } 1161 if (err != 0) { 1162 count = err; 1163 goto errout; 1164 } 1165 count++; 1166 } 1167 errout: 1168 brelse(bh); 1169 fscrypt_fname_free_buffer(&fname_crypto_str); 1170 return count; 1171 } 1172 1173 1174 /* 1175 * This function fills a red-black tree with information from a 1176 * directory. We start scanning the directory in hash order, starting 1177 * at start_hash and start_minor_hash. 1178 * 1179 * This function returns the number of entries inserted into the tree, 1180 * or a negative error code. 1181 */ 1182 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash, 1183 __u32 start_minor_hash, __u32 *next_hash) 1184 { 1185 struct dx_hash_info hinfo; 1186 struct ext4_dir_entry_2 *de; 1187 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 1188 struct inode *dir; 1189 ext4_lblk_t block; 1190 int count = 0; 1191 int ret, err; 1192 __u32 hashval; 1193 struct fscrypt_str tmp_str; 1194 1195 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n", 1196 start_hash, start_minor_hash)); 1197 dir = file_inode(dir_file); 1198 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) { 1199 if (ext4_hash_in_dirent(dir)) 1200 hinfo.hash_version = DX_HASH_SIPHASH; 1201 else 1202 hinfo.hash_version = 1203 EXT4_SB(dir->i_sb)->s_def_hash_version; 1204 if (hinfo.hash_version <= DX_HASH_TEA) 1205 hinfo.hash_version += 1206 EXT4_SB(dir->i_sb)->s_hash_unsigned; 1207 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; 1208 if (ext4_has_inline_data(dir)) { 1209 int has_inline_data = 1; 1210 count = ext4_inlinedir_to_tree(dir_file, dir, 0, 1211 &hinfo, start_hash, 1212 start_minor_hash, 1213 &has_inline_data); 1214 if (has_inline_data) { 1215 *next_hash = ~0; 1216 return count; 1217 } 1218 } 1219 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo, 1220 start_hash, start_minor_hash); 1221 *next_hash = ~0; 1222 return count; 1223 } 1224 hinfo.hash = start_hash; 1225 hinfo.minor_hash = 0; 1226 frame = dx_probe(NULL, dir, &hinfo, frames); 1227 if (IS_ERR(frame)) 1228 return PTR_ERR(frame); 1229 1230 /* Add '.' and '..' from the htree header */ 1231 if (!start_hash && !start_minor_hash) { 1232 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; 1233 tmp_str.name = de->name; 1234 tmp_str.len = de->name_len; 1235 err = ext4_htree_store_dirent(dir_file, 0, 0, 1236 de, &tmp_str); 1237 if (err != 0) 1238 goto errout; 1239 count++; 1240 } 1241 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) { 1242 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; 1243 de = ext4_next_entry(de, dir->i_sb->s_blocksize); 1244 tmp_str.name = de->name; 1245 tmp_str.len = de->name_len; 1246 err = ext4_htree_store_dirent(dir_file, 2, 0, 1247 de, &tmp_str); 1248 if (err != 0) 1249 goto errout; 1250 count++; 1251 } 1252 1253 while (1) { 1254 if (fatal_signal_pending(current)) { 1255 err = -ERESTARTSYS; 1256 goto errout; 1257 } 1258 cond_resched(); 1259 block = dx_get_block(frame->at); 1260 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo, 1261 start_hash, start_minor_hash); 1262 if (ret < 0) { 1263 err = ret; 1264 goto errout; 1265 } 1266 count += ret; 1267 hashval = ~0; 1268 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS, 1269 frame, frames, &hashval); 1270 *next_hash = hashval; 1271 if (ret < 0) { 1272 err = ret; 1273 goto errout; 1274 } 1275 /* 1276 * Stop if: (a) there are no more entries, or 1277 * (b) we have inserted at least one entry and the 1278 * next hash value is not a continuation 1279 */ 1280 if ((ret == 0) || 1281 (count && ((hashval & 1) == 0))) 1282 break; 1283 } 1284 dx_release(frames); 1285 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, " 1286 "next hash: %x\n", count, *next_hash)); 1287 return count; 1288 errout: 1289 dx_release(frames); 1290 return (err); 1291 } 1292 1293 static inline int search_dirblock(struct buffer_head *bh, 1294 struct inode *dir, 1295 struct ext4_filename *fname, 1296 unsigned int offset, 1297 struct ext4_dir_entry_2 **res_dir) 1298 { 1299 return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir, 1300 fname, offset, res_dir); 1301 } 1302 1303 /* 1304 * Directory block splitting, compacting 1305 */ 1306 1307 /* 1308 * Create map of hash values, offsets, and sizes, stored at end of block. 1309 * Returns number of entries mapped. 1310 */ 1311 static int dx_make_map(struct inode *dir, struct buffer_head *bh, 1312 struct dx_hash_info *hinfo, 1313 struct dx_map_entry *map_tail) 1314 { 1315 int count = 0; 1316 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)bh->b_data; 1317 unsigned int buflen = bh->b_size; 1318 char *base = bh->b_data; 1319 struct dx_hash_info h = *hinfo; 1320 int blocksize = EXT4_BLOCK_SIZE(dir->i_sb); 1321 1322 if (ext4_has_metadata_csum(dir->i_sb)) 1323 buflen -= sizeof(struct ext4_dir_entry_tail); 1324 1325 while ((char *) de < base + buflen) { 1326 if (ext4_check_dir_entry(dir, NULL, de, bh, base, buflen, 1327 ((char *)de) - base)) 1328 return -EFSCORRUPTED; 1329 if (de->name_len && de->inode) { 1330 if (ext4_hash_in_dirent(dir)) 1331 h.hash = EXT4_DIRENT_HASH(de); 1332 else { 1333 int err = ext4fs_dirhash(dir, de->name, 1334 de->name_len, &h); 1335 if (err < 0) 1336 return err; 1337 } 1338 map_tail--; 1339 map_tail->hash = h.hash; 1340 map_tail->offs = ((char *) de - base)>>2; 1341 map_tail->size = ext4_rec_len_from_disk(de->rec_len, 1342 blocksize); 1343 count++; 1344 cond_resched(); 1345 } 1346 de = ext4_next_entry(de, blocksize); 1347 } 1348 return count; 1349 } 1350 1351 /* Sort map by hash value */ 1352 static void dx_sort_map (struct dx_map_entry *map, unsigned count) 1353 { 1354 struct dx_map_entry *p, *q, *top = map + count - 1; 1355 int more; 1356 /* Combsort until bubble sort doesn't suck */ 1357 while (count > 2) { 1358 count = count*10/13; 1359 if (count - 9 < 2) /* 9, 10 -> 11 */ 1360 count = 11; 1361 for (p = top, q = p - count; q >= map; p--, q--) 1362 if (p->hash < q->hash) 1363 swap(*p, *q); 1364 } 1365 /* Garden variety bubble sort */ 1366 do { 1367 more = 0; 1368 q = top; 1369 while (q-- > map) { 1370 if (q[1].hash >= q[0].hash) 1371 continue; 1372 swap(*(q+1), *q); 1373 more = 1; 1374 } 1375 } while(more); 1376 } 1377 1378 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block) 1379 { 1380 struct dx_entry *entries = frame->entries; 1381 struct dx_entry *old = frame->at, *new = old + 1; 1382 int count = dx_get_count(entries); 1383 1384 ASSERT(count < dx_get_limit(entries)); 1385 ASSERT(old < entries + count); 1386 memmove(new + 1, new, (char *)(entries + count) - (char *)(new)); 1387 dx_set_hash(new, hash); 1388 dx_set_block(new, block); 1389 dx_set_count(entries, count + 1); 1390 } 1391 1392 #if IS_ENABLED(CONFIG_UNICODE) 1393 /* 1394 * Test whether a case-insensitive directory entry matches the filename 1395 * being searched for. If quick is set, assume the name being looked up 1396 * is already in the casefolded form. 1397 * 1398 * Returns: 0 if the directory entry matches, more than 0 if it 1399 * doesn't match or less than zero on error. 1400 */ 1401 static int ext4_ci_compare(const struct inode *parent, const struct qstr *name, 1402 u8 *de_name, size_t de_name_len, bool quick) 1403 { 1404 const struct super_block *sb = parent->i_sb; 1405 const struct unicode_map *um = sb->s_encoding; 1406 struct fscrypt_str decrypted_name = FSTR_INIT(NULL, de_name_len); 1407 struct qstr entry = QSTR_INIT(de_name, de_name_len); 1408 int ret; 1409 1410 if (IS_ENCRYPTED(parent)) { 1411 const struct fscrypt_str encrypted_name = 1412 FSTR_INIT(de_name, de_name_len); 1413 1414 decrypted_name.name = kmalloc(de_name_len, GFP_KERNEL); 1415 if (!decrypted_name.name) 1416 return -ENOMEM; 1417 ret = fscrypt_fname_disk_to_usr(parent, 0, 0, &encrypted_name, 1418 &decrypted_name); 1419 if (ret < 0) 1420 goto out; 1421 entry.name = decrypted_name.name; 1422 entry.len = decrypted_name.len; 1423 } 1424 1425 if (quick) 1426 ret = utf8_strncasecmp_folded(um, name, &entry); 1427 else 1428 ret = utf8_strncasecmp(um, name, &entry); 1429 if (ret < 0) { 1430 /* Handle invalid character sequence as either an error 1431 * or as an opaque byte sequence. 1432 */ 1433 if (sb_has_strict_encoding(sb)) 1434 ret = -EINVAL; 1435 else if (name->len != entry.len) 1436 ret = 1; 1437 else 1438 ret = !!memcmp(name->name, entry.name, entry.len); 1439 } 1440 out: 1441 kfree(decrypted_name.name); 1442 return ret; 1443 } 1444 1445 int ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname, 1446 struct ext4_filename *name) 1447 { 1448 struct fscrypt_str *cf_name = &name->cf_name; 1449 struct dx_hash_info *hinfo = &name->hinfo; 1450 int len; 1451 1452 if (!IS_CASEFOLDED(dir) || 1453 (IS_ENCRYPTED(dir) && !fscrypt_has_encryption_key(dir))) { 1454 cf_name->name = NULL; 1455 return 0; 1456 } 1457 1458 cf_name->name = kmalloc(EXT4_NAME_LEN, GFP_NOFS); 1459 if (!cf_name->name) 1460 return -ENOMEM; 1461 1462 len = utf8_casefold(dir->i_sb->s_encoding, 1463 iname, cf_name->name, 1464 EXT4_NAME_LEN); 1465 if (len <= 0) { 1466 kfree(cf_name->name); 1467 cf_name->name = NULL; 1468 } 1469 cf_name->len = (unsigned) len; 1470 if (!IS_ENCRYPTED(dir)) 1471 return 0; 1472 1473 hinfo->hash_version = DX_HASH_SIPHASH; 1474 hinfo->seed = NULL; 1475 if (cf_name->name) 1476 return ext4fs_dirhash(dir, cf_name->name, cf_name->len, hinfo); 1477 else 1478 return ext4fs_dirhash(dir, iname->name, iname->len, hinfo); 1479 } 1480 #endif 1481 1482 /* 1483 * Test whether a directory entry matches the filename being searched for. 1484 * 1485 * Return: %true if the directory entry matches, otherwise %false. 1486 */ 1487 static bool ext4_match(struct inode *parent, 1488 const struct ext4_filename *fname, 1489 struct ext4_dir_entry_2 *de) 1490 { 1491 struct fscrypt_name f; 1492 1493 if (!de->inode) 1494 return false; 1495 1496 f.usr_fname = fname->usr_fname; 1497 f.disk_name = fname->disk_name; 1498 #ifdef CONFIG_FS_ENCRYPTION 1499 f.crypto_buf = fname->crypto_buf; 1500 #endif 1501 1502 #if IS_ENABLED(CONFIG_UNICODE) 1503 if (IS_CASEFOLDED(parent) && 1504 (!IS_ENCRYPTED(parent) || fscrypt_has_encryption_key(parent))) { 1505 if (fname->cf_name.name) { 1506 struct qstr cf = {.name = fname->cf_name.name, 1507 .len = fname->cf_name.len}; 1508 if (IS_ENCRYPTED(parent)) { 1509 if (fname->hinfo.hash != EXT4_DIRENT_HASH(de) || 1510 fname->hinfo.minor_hash != 1511 EXT4_DIRENT_MINOR_HASH(de)) { 1512 1513 return false; 1514 } 1515 } 1516 return !ext4_ci_compare(parent, &cf, de->name, 1517 de->name_len, true); 1518 } 1519 return !ext4_ci_compare(parent, fname->usr_fname, de->name, 1520 de->name_len, false); 1521 } 1522 #endif 1523 1524 return fscrypt_match_name(&f, de->name, de->name_len); 1525 } 1526 1527 /* 1528 * Returns 0 if not found, -1 on failure, and 1 on success 1529 */ 1530 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size, 1531 struct inode *dir, struct ext4_filename *fname, 1532 unsigned int offset, struct ext4_dir_entry_2 **res_dir) 1533 { 1534 struct ext4_dir_entry_2 * de; 1535 char * dlimit; 1536 int de_len; 1537 1538 de = (struct ext4_dir_entry_2 *)search_buf; 1539 dlimit = search_buf + buf_size; 1540 while ((char *) de < dlimit - EXT4_BASE_DIR_LEN) { 1541 /* this code is executed quadratically often */ 1542 /* do minimal checking `by hand' */ 1543 if (de->name + de->name_len <= dlimit && 1544 ext4_match(dir, fname, de)) { 1545 /* found a match - just to be sure, do 1546 * a full check */ 1547 if (ext4_check_dir_entry(dir, NULL, de, bh, search_buf, 1548 buf_size, offset)) 1549 return -1; 1550 *res_dir = de; 1551 return 1; 1552 } 1553 /* prevent looping on a bad block */ 1554 de_len = ext4_rec_len_from_disk(de->rec_len, 1555 dir->i_sb->s_blocksize); 1556 if (de_len <= 0) 1557 return -1; 1558 offset += de_len; 1559 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len); 1560 } 1561 return 0; 1562 } 1563 1564 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block, 1565 struct ext4_dir_entry *de) 1566 { 1567 struct super_block *sb = dir->i_sb; 1568 1569 if (!is_dx(dir)) 1570 return 0; 1571 if (block == 0) 1572 return 1; 1573 if (de->inode == 0 && 1574 ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) == 1575 sb->s_blocksize) 1576 return 1; 1577 return 0; 1578 } 1579 1580 /* 1581 * __ext4_find_entry() 1582 * 1583 * finds an entry in the specified directory with the wanted name. It 1584 * returns the cache buffer in which the entry was found, and the entry 1585 * itself (as a parameter - res_dir). It does NOT read the inode of the 1586 * entry - you'll have to do that yourself if you want to. 1587 * 1588 * The returned buffer_head has ->b_count elevated. The caller is expected 1589 * to brelse() it when appropriate. 1590 */ 1591 static struct buffer_head *__ext4_find_entry(struct inode *dir, 1592 struct ext4_filename *fname, 1593 struct ext4_dir_entry_2 **res_dir, 1594 int *inlined) 1595 { 1596 struct super_block *sb; 1597 struct buffer_head *bh_use[NAMEI_RA_SIZE]; 1598 struct buffer_head *bh, *ret = NULL; 1599 ext4_lblk_t start, block; 1600 const u8 *name = fname->usr_fname->name; 1601 size_t ra_max = 0; /* Number of bh's in the readahead 1602 buffer, bh_use[] */ 1603 size_t ra_ptr = 0; /* Current index into readahead 1604 buffer */ 1605 ext4_lblk_t nblocks; 1606 int i, namelen, retval; 1607 1608 *res_dir = NULL; 1609 sb = dir->i_sb; 1610 namelen = fname->usr_fname->len; 1611 if (namelen > EXT4_NAME_LEN) 1612 return NULL; 1613 1614 if (ext4_has_inline_data(dir)) { 1615 int has_inline_data = 1; 1616 ret = ext4_find_inline_entry(dir, fname, res_dir, 1617 &has_inline_data); 1618 if (inlined) 1619 *inlined = has_inline_data; 1620 if (has_inline_data) 1621 goto cleanup_and_exit; 1622 } 1623 1624 if ((namelen <= 2) && (name[0] == '.') && 1625 (name[1] == '.' || name[1] == '\0')) { 1626 /* 1627 * "." or ".." will only be in the first block 1628 * NFS may look up ".."; "." should be handled by the VFS 1629 */ 1630 block = start = 0; 1631 nblocks = 1; 1632 goto restart; 1633 } 1634 if (is_dx(dir)) { 1635 ret = ext4_dx_find_entry(dir, fname, res_dir); 1636 /* 1637 * On success, or if the error was file not found, 1638 * return. Otherwise, fall back to doing a search the 1639 * old fashioned way. 1640 */ 1641 if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR) 1642 goto cleanup_and_exit; 1643 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, " 1644 "falling back\n")); 1645 ret = NULL; 1646 } 1647 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); 1648 if (!nblocks) { 1649 ret = NULL; 1650 goto cleanup_and_exit; 1651 } 1652 start = EXT4_I(dir)->i_dir_start_lookup; 1653 if (start >= nblocks) 1654 start = 0; 1655 block = start; 1656 restart: 1657 do { 1658 /* 1659 * We deal with the read-ahead logic here. 1660 */ 1661 cond_resched(); 1662 if (ra_ptr >= ra_max) { 1663 /* Refill the readahead buffer */ 1664 ra_ptr = 0; 1665 if (block < start) 1666 ra_max = start - block; 1667 else 1668 ra_max = nblocks - block; 1669 ra_max = min(ra_max, ARRAY_SIZE(bh_use)); 1670 retval = ext4_bread_batch(dir, block, ra_max, 1671 false /* wait */, bh_use); 1672 if (retval) { 1673 ret = ERR_PTR(retval); 1674 ra_max = 0; 1675 goto cleanup_and_exit; 1676 } 1677 } 1678 if ((bh = bh_use[ra_ptr++]) == NULL) 1679 goto next; 1680 wait_on_buffer(bh); 1681 if (!buffer_uptodate(bh)) { 1682 EXT4_ERROR_INODE_ERR(dir, EIO, 1683 "reading directory lblock %lu", 1684 (unsigned long) block); 1685 brelse(bh); 1686 ret = ERR_PTR(-EIO); 1687 goto cleanup_and_exit; 1688 } 1689 if (!buffer_verified(bh) && 1690 !is_dx_internal_node(dir, block, 1691 (struct ext4_dir_entry *)bh->b_data) && 1692 !ext4_dirblock_csum_verify(dir, bh)) { 1693 EXT4_ERROR_INODE_ERR(dir, EFSBADCRC, 1694 "checksumming directory " 1695 "block %lu", (unsigned long)block); 1696 brelse(bh); 1697 ret = ERR_PTR(-EFSBADCRC); 1698 goto cleanup_and_exit; 1699 } 1700 set_buffer_verified(bh); 1701 i = search_dirblock(bh, dir, fname, 1702 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir); 1703 if (i == 1) { 1704 EXT4_I(dir)->i_dir_start_lookup = block; 1705 ret = bh; 1706 goto cleanup_and_exit; 1707 } else { 1708 brelse(bh); 1709 if (i < 0) 1710 goto cleanup_and_exit; 1711 } 1712 next: 1713 if (++block >= nblocks) 1714 block = 0; 1715 } while (block != start); 1716 1717 /* 1718 * If the directory has grown while we were searching, then 1719 * search the last part of the directory before giving up. 1720 */ 1721 block = nblocks; 1722 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); 1723 if (block < nblocks) { 1724 start = 0; 1725 goto restart; 1726 } 1727 1728 cleanup_and_exit: 1729 /* Clean up the read-ahead blocks */ 1730 for (; ra_ptr < ra_max; ra_ptr++) 1731 brelse(bh_use[ra_ptr]); 1732 return ret; 1733 } 1734 1735 static struct buffer_head *ext4_find_entry(struct inode *dir, 1736 const struct qstr *d_name, 1737 struct ext4_dir_entry_2 **res_dir, 1738 int *inlined) 1739 { 1740 int err; 1741 struct ext4_filename fname; 1742 struct buffer_head *bh; 1743 1744 err = ext4_fname_setup_filename(dir, d_name, 1, &fname); 1745 if (err == -ENOENT) 1746 return NULL; 1747 if (err) 1748 return ERR_PTR(err); 1749 1750 bh = __ext4_find_entry(dir, &fname, res_dir, inlined); 1751 1752 ext4_fname_free_filename(&fname); 1753 return bh; 1754 } 1755 1756 static struct buffer_head *ext4_lookup_entry(struct inode *dir, 1757 struct dentry *dentry, 1758 struct ext4_dir_entry_2 **res_dir) 1759 { 1760 int err; 1761 struct ext4_filename fname; 1762 struct buffer_head *bh; 1763 1764 err = ext4_fname_prepare_lookup(dir, dentry, &fname); 1765 if (err == -ENOENT) 1766 return NULL; 1767 if (err) 1768 return ERR_PTR(err); 1769 1770 bh = __ext4_find_entry(dir, &fname, res_dir, NULL); 1771 1772 ext4_fname_free_filename(&fname); 1773 return bh; 1774 } 1775 1776 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, 1777 struct ext4_filename *fname, 1778 struct ext4_dir_entry_2 **res_dir) 1779 { 1780 struct super_block * sb = dir->i_sb; 1781 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 1782 struct buffer_head *bh; 1783 ext4_lblk_t block; 1784 int retval; 1785 1786 #ifdef CONFIG_FS_ENCRYPTION 1787 *res_dir = NULL; 1788 #endif 1789 frame = dx_probe(fname, dir, NULL, frames); 1790 if (IS_ERR(frame)) 1791 return (struct buffer_head *) frame; 1792 do { 1793 block = dx_get_block(frame->at); 1794 bh = ext4_read_dirblock(dir, block, DIRENT_HTREE); 1795 if (IS_ERR(bh)) 1796 goto errout; 1797 1798 retval = search_dirblock(bh, dir, fname, 1799 block << EXT4_BLOCK_SIZE_BITS(sb), 1800 res_dir); 1801 if (retval == 1) 1802 goto success; 1803 brelse(bh); 1804 if (retval == -1) { 1805 bh = ERR_PTR(ERR_BAD_DX_DIR); 1806 goto errout; 1807 } 1808 1809 /* Check to see if we should continue to search */ 1810 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame, 1811 frames, NULL); 1812 if (retval < 0) { 1813 ext4_warning_inode(dir, 1814 "error %d reading directory index block", 1815 retval); 1816 bh = ERR_PTR(retval); 1817 goto errout; 1818 } 1819 } while (retval == 1); 1820 1821 bh = NULL; 1822 errout: 1823 dxtrace(printk(KERN_DEBUG "%s not found\n", fname->usr_fname->name)); 1824 success: 1825 dx_release(frames); 1826 return bh; 1827 } 1828 1829 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 1830 { 1831 struct inode *inode; 1832 struct ext4_dir_entry_2 *de; 1833 struct buffer_head *bh; 1834 1835 if (dentry->d_name.len > EXT4_NAME_LEN) 1836 return ERR_PTR(-ENAMETOOLONG); 1837 1838 bh = ext4_lookup_entry(dir, dentry, &de); 1839 if (IS_ERR(bh)) 1840 return ERR_CAST(bh); 1841 inode = NULL; 1842 if (bh) { 1843 __u32 ino = le32_to_cpu(de->inode); 1844 brelse(bh); 1845 if (!ext4_valid_inum(dir->i_sb, ino)) { 1846 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino); 1847 return ERR_PTR(-EFSCORRUPTED); 1848 } 1849 if (unlikely(ino == dir->i_ino)) { 1850 EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir", 1851 dentry); 1852 return ERR_PTR(-EFSCORRUPTED); 1853 } 1854 inode = ext4_iget(dir->i_sb, ino, EXT4_IGET_NORMAL); 1855 if (inode == ERR_PTR(-ESTALE)) { 1856 EXT4_ERROR_INODE(dir, 1857 "deleted inode referenced: %u", 1858 ino); 1859 return ERR_PTR(-EFSCORRUPTED); 1860 } 1861 if (!IS_ERR(inode) && IS_ENCRYPTED(dir) && 1862 (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) && 1863 !fscrypt_has_permitted_context(dir, inode)) { 1864 ext4_warning(inode->i_sb, 1865 "Inconsistent encryption contexts: %lu/%lu", 1866 dir->i_ino, inode->i_ino); 1867 iput(inode); 1868 return ERR_PTR(-EPERM); 1869 } 1870 } 1871 1872 #if IS_ENABLED(CONFIG_UNICODE) 1873 if (!inode && IS_CASEFOLDED(dir)) { 1874 /* Eventually we want to call d_add_ci(dentry, NULL) 1875 * for negative dentries in the encoding case as 1876 * well. For now, prevent the negative dentry 1877 * from being cached. 1878 */ 1879 return NULL; 1880 } 1881 #endif 1882 return d_splice_alias(inode, dentry); 1883 } 1884 1885 1886 struct dentry *ext4_get_parent(struct dentry *child) 1887 { 1888 __u32 ino; 1889 struct ext4_dir_entry_2 * de; 1890 struct buffer_head *bh; 1891 1892 bh = ext4_find_entry(d_inode(child), &dotdot_name, &de, NULL); 1893 if (IS_ERR(bh)) 1894 return ERR_CAST(bh); 1895 if (!bh) 1896 return ERR_PTR(-ENOENT); 1897 ino = le32_to_cpu(de->inode); 1898 brelse(bh); 1899 1900 if (!ext4_valid_inum(child->d_sb, ino)) { 1901 EXT4_ERROR_INODE(d_inode(child), 1902 "bad parent inode number: %u", ino); 1903 return ERR_PTR(-EFSCORRUPTED); 1904 } 1905 1906 return d_obtain_alias(ext4_iget(child->d_sb, ino, EXT4_IGET_NORMAL)); 1907 } 1908 1909 /* 1910 * Move count entries from end of map between two memory locations. 1911 * Returns pointer to last entry moved. 1912 */ 1913 static struct ext4_dir_entry_2 * 1914 dx_move_dirents(struct inode *dir, char *from, char *to, 1915 struct dx_map_entry *map, int count, 1916 unsigned blocksize) 1917 { 1918 unsigned rec_len = 0; 1919 1920 while (count--) { 1921 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) 1922 (from + (map->offs<<2)); 1923 rec_len = ext4_dir_rec_len(de->name_len, dir); 1924 1925 memcpy (to, de, rec_len); 1926 ((struct ext4_dir_entry_2 *) to)->rec_len = 1927 ext4_rec_len_to_disk(rec_len, blocksize); 1928 1929 /* wipe dir_entry excluding the rec_len field */ 1930 de->inode = 0; 1931 memset(&de->name_len, 0, ext4_rec_len_from_disk(de->rec_len, 1932 blocksize) - 1933 offsetof(struct ext4_dir_entry_2, 1934 name_len)); 1935 1936 map++; 1937 to += rec_len; 1938 } 1939 return (struct ext4_dir_entry_2 *) (to - rec_len); 1940 } 1941 1942 /* 1943 * Compact each dir entry in the range to the minimal rec_len. 1944 * Returns pointer to last entry in range. 1945 */ 1946 static struct ext4_dir_entry_2 *dx_pack_dirents(struct inode *dir, char *base, 1947 unsigned int blocksize) 1948 { 1949 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base; 1950 unsigned rec_len = 0; 1951 1952 prev = to = de; 1953 while ((char*)de < base + blocksize) { 1954 next = ext4_next_entry(de, blocksize); 1955 if (de->inode && de->name_len) { 1956 rec_len = ext4_dir_rec_len(de->name_len, dir); 1957 if (de > to) 1958 memmove(to, de, rec_len); 1959 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize); 1960 prev = to; 1961 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len); 1962 } 1963 de = next; 1964 } 1965 return prev; 1966 } 1967 1968 /* 1969 * Split a full leaf block to make room for a new dir entry. 1970 * Allocate a new block, and move entries so that they are approx. equally full. 1971 * Returns pointer to de in block into which the new entry will be inserted. 1972 */ 1973 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir, 1974 struct buffer_head **bh,struct dx_frame *frame, 1975 struct dx_hash_info *hinfo) 1976 { 1977 unsigned blocksize = dir->i_sb->s_blocksize; 1978 unsigned continued; 1979 int count; 1980 struct buffer_head *bh2; 1981 ext4_lblk_t newblock; 1982 u32 hash2; 1983 struct dx_map_entry *map; 1984 char *data1 = (*bh)->b_data, *data2; 1985 unsigned split, move, size; 1986 struct ext4_dir_entry_2 *de = NULL, *de2; 1987 int csum_size = 0; 1988 int err = 0, i; 1989 1990 if (ext4_has_metadata_csum(dir->i_sb)) 1991 csum_size = sizeof(struct ext4_dir_entry_tail); 1992 1993 bh2 = ext4_append(handle, dir, &newblock); 1994 if (IS_ERR(bh2)) { 1995 brelse(*bh); 1996 *bh = NULL; 1997 return (struct ext4_dir_entry_2 *) bh2; 1998 } 1999 2000 BUFFER_TRACE(*bh, "get_write_access"); 2001 err = ext4_journal_get_write_access(handle, dir->i_sb, *bh, 2002 EXT4_JTR_NONE); 2003 if (err) 2004 goto journal_error; 2005 2006 BUFFER_TRACE(frame->bh, "get_write_access"); 2007 err = ext4_journal_get_write_access(handle, dir->i_sb, frame->bh, 2008 EXT4_JTR_NONE); 2009 if (err) 2010 goto journal_error; 2011 2012 data2 = bh2->b_data; 2013 2014 /* create map in the end of data2 block */ 2015 map = (struct dx_map_entry *) (data2 + blocksize); 2016 count = dx_make_map(dir, *bh, hinfo, map); 2017 if (count < 0) { 2018 err = count; 2019 goto journal_error; 2020 } 2021 map -= count; 2022 dx_sort_map(map, count); 2023 /* Ensure that neither split block is over half full */ 2024 size = 0; 2025 move = 0; 2026 for (i = count-1; i >= 0; i--) { 2027 /* is more than half of this entry in 2nd half of the block? */ 2028 if (size + map[i].size/2 > blocksize/2) 2029 break; 2030 size += map[i].size; 2031 move++; 2032 } 2033 /* 2034 * map index at which we will split 2035 * 2036 * If the sum of active entries didn't exceed half the block size, just 2037 * split it in half by count; each resulting block will have at least 2038 * half the space free. 2039 */ 2040 if (i > 0) 2041 split = count - move; 2042 else 2043 split = count/2; 2044 2045 hash2 = map[split].hash; 2046 continued = hash2 == map[split - 1].hash; 2047 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n", 2048 (unsigned long)dx_get_block(frame->at), 2049 hash2, split, count-split)); 2050 2051 /* Fancy dance to stay within two buffers */ 2052 de2 = dx_move_dirents(dir, data1, data2, map + split, count - split, 2053 blocksize); 2054 de = dx_pack_dirents(dir, data1, blocksize); 2055 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) - 2056 (char *) de, 2057 blocksize); 2058 de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) - 2059 (char *) de2, 2060 blocksize); 2061 if (csum_size) { 2062 ext4_initialize_dirent_tail(*bh, blocksize); 2063 ext4_initialize_dirent_tail(bh2, blocksize); 2064 } 2065 2066 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1, 2067 blocksize, 1)); 2068 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2, 2069 blocksize, 1)); 2070 2071 /* Which block gets the new entry? */ 2072 if (hinfo->hash >= hash2) { 2073 swap(*bh, bh2); 2074 de = de2; 2075 } 2076 dx_insert_block(frame, hash2 + continued, newblock); 2077 err = ext4_handle_dirty_dirblock(handle, dir, bh2); 2078 if (err) 2079 goto journal_error; 2080 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 2081 if (err) 2082 goto journal_error; 2083 brelse(bh2); 2084 dxtrace(dx_show_index("frame", frame->entries)); 2085 return de; 2086 2087 journal_error: 2088 brelse(*bh); 2089 brelse(bh2); 2090 *bh = NULL; 2091 ext4_std_error(dir->i_sb, err); 2092 return ERR_PTR(err); 2093 } 2094 2095 int ext4_find_dest_de(struct inode *dir, struct inode *inode, 2096 struct buffer_head *bh, 2097 void *buf, int buf_size, 2098 struct ext4_filename *fname, 2099 struct ext4_dir_entry_2 **dest_de) 2100 { 2101 struct ext4_dir_entry_2 *de; 2102 unsigned short reclen = ext4_dir_rec_len(fname_len(fname), dir); 2103 int nlen, rlen; 2104 unsigned int offset = 0; 2105 char *top; 2106 2107 de = buf; 2108 top = buf + buf_size - reclen; 2109 while ((char *) de <= top) { 2110 if (ext4_check_dir_entry(dir, NULL, de, bh, 2111 buf, buf_size, offset)) 2112 return -EFSCORRUPTED; 2113 if (ext4_match(dir, fname, de)) 2114 return -EEXIST; 2115 nlen = ext4_dir_rec_len(de->name_len, dir); 2116 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 2117 if ((de->inode ? rlen - nlen : rlen) >= reclen) 2118 break; 2119 de = (struct ext4_dir_entry_2 *)((char *)de + rlen); 2120 offset += rlen; 2121 } 2122 if ((char *) de > top) 2123 return -ENOSPC; 2124 2125 *dest_de = de; 2126 return 0; 2127 } 2128 2129 void ext4_insert_dentry(struct inode *dir, 2130 struct inode *inode, 2131 struct ext4_dir_entry_2 *de, 2132 int buf_size, 2133 struct ext4_filename *fname) 2134 { 2135 2136 int nlen, rlen; 2137 2138 nlen = ext4_dir_rec_len(de->name_len, dir); 2139 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 2140 if (de->inode) { 2141 struct ext4_dir_entry_2 *de1 = 2142 (struct ext4_dir_entry_2 *)((char *)de + nlen); 2143 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size); 2144 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size); 2145 de = de1; 2146 } 2147 de->file_type = EXT4_FT_UNKNOWN; 2148 de->inode = cpu_to_le32(inode->i_ino); 2149 ext4_set_de_type(inode->i_sb, de, inode->i_mode); 2150 de->name_len = fname_len(fname); 2151 memcpy(de->name, fname_name(fname), fname_len(fname)); 2152 if (ext4_hash_in_dirent(dir)) { 2153 struct dx_hash_info *hinfo = &fname->hinfo; 2154 2155 EXT4_DIRENT_HASHES(de)->hash = cpu_to_le32(hinfo->hash); 2156 EXT4_DIRENT_HASHES(de)->minor_hash = 2157 cpu_to_le32(hinfo->minor_hash); 2158 } 2159 } 2160 2161 /* 2162 * Add a new entry into a directory (leaf) block. If de is non-NULL, 2163 * it points to a directory entry which is guaranteed to be large 2164 * enough for new directory entry. If de is NULL, then 2165 * add_dirent_to_buf will attempt search the directory block for 2166 * space. It will return -ENOSPC if no space is available, and -EIO 2167 * and -EEXIST if directory entry already exists. 2168 */ 2169 static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname, 2170 struct inode *dir, 2171 struct inode *inode, struct ext4_dir_entry_2 *de, 2172 struct buffer_head *bh) 2173 { 2174 unsigned int blocksize = dir->i_sb->s_blocksize; 2175 int csum_size = 0; 2176 int err, err2; 2177 2178 if (ext4_has_metadata_csum(inode->i_sb)) 2179 csum_size = sizeof(struct ext4_dir_entry_tail); 2180 2181 if (!de) { 2182 err = ext4_find_dest_de(dir, inode, bh, bh->b_data, 2183 blocksize - csum_size, fname, &de); 2184 if (err) 2185 return err; 2186 } 2187 BUFFER_TRACE(bh, "get_write_access"); 2188 err = ext4_journal_get_write_access(handle, dir->i_sb, bh, 2189 EXT4_JTR_NONE); 2190 if (err) { 2191 ext4_std_error(dir->i_sb, err); 2192 return err; 2193 } 2194 2195 /* By now the buffer is marked for journaling */ 2196 ext4_insert_dentry(dir, inode, de, blocksize, fname); 2197 2198 /* 2199 * XXX shouldn't update any times until successful 2200 * completion of syscall, but too many callers depend 2201 * on this. 2202 * 2203 * XXX similarly, too many callers depend on 2204 * ext4_new_inode() setting the times, but error 2205 * recovery deletes the inode, so the worst that can 2206 * happen is that the times are slightly out of date 2207 * and/or different from the directory change time. 2208 */ 2209 inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir)); 2210 ext4_update_dx_flag(dir); 2211 inode_inc_iversion(dir); 2212 err2 = ext4_mark_inode_dirty(handle, dir); 2213 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); 2214 err = ext4_handle_dirty_dirblock(handle, dir, bh); 2215 if (err) 2216 ext4_std_error(dir->i_sb, err); 2217 return err ? err : err2; 2218 } 2219 2220 /* 2221 * This converts a one block unindexed directory to a 3 block indexed 2222 * directory, and adds the dentry to the indexed directory. 2223 */ 2224 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname, 2225 struct inode *dir, 2226 struct inode *inode, struct buffer_head *bh) 2227 { 2228 struct buffer_head *bh2; 2229 struct dx_root *root; 2230 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 2231 struct dx_entry *entries; 2232 struct ext4_dir_entry_2 *de, *de2; 2233 char *data2, *top; 2234 unsigned len; 2235 int retval; 2236 unsigned blocksize; 2237 ext4_lblk_t block; 2238 struct fake_dirent *fde; 2239 int csum_size = 0; 2240 2241 if (ext4_has_metadata_csum(inode->i_sb)) 2242 csum_size = sizeof(struct ext4_dir_entry_tail); 2243 2244 blocksize = dir->i_sb->s_blocksize; 2245 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino)); 2246 BUFFER_TRACE(bh, "get_write_access"); 2247 retval = ext4_journal_get_write_access(handle, dir->i_sb, bh, 2248 EXT4_JTR_NONE); 2249 if (retval) { 2250 ext4_std_error(dir->i_sb, retval); 2251 brelse(bh); 2252 return retval; 2253 } 2254 root = (struct dx_root *) bh->b_data; 2255 2256 /* The 0th block becomes the root, move the dirents out */ 2257 fde = &root->dotdot; 2258 de = (struct ext4_dir_entry_2 *)((char *)fde + 2259 ext4_rec_len_from_disk(fde->rec_len, blocksize)); 2260 if ((char *) de >= (((char *) root) + blocksize)) { 2261 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'"); 2262 brelse(bh); 2263 return -EFSCORRUPTED; 2264 } 2265 len = ((char *) root) + (blocksize - csum_size) - (char *) de; 2266 2267 /* Allocate new block for the 0th block's dirents */ 2268 bh2 = ext4_append(handle, dir, &block); 2269 if (IS_ERR(bh2)) { 2270 brelse(bh); 2271 return PTR_ERR(bh2); 2272 } 2273 ext4_set_inode_flag(dir, EXT4_INODE_INDEX); 2274 data2 = bh2->b_data; 2275 2276 memcpy(data2, de, len); 2277 memset(de, 0, len); /* wipe old data */ 2278 de = (struct ext4_dir_entry_2 *) data2; 2279 top = data2 + len; 2280 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top) { 2281 if (ext4_check_dir_entry(dir, NULL, de, bh2, data2, len, 2282 (char *)de - data2)) { 2283 brelse(bh2); 2284 brelse(bh); 2285 return -EFSCORRUPTED; 2286 } 2287 de = de2; 2288 } 2289 de->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) - 2290 (char *) de, blocksize); 2291 2292 if (csum_size) 2293 ext4_initialize_dirent_tail(bh2, blocksize); 2294 2295 /* Initialize the root; the dot dirents already exist */ 2296 de = (struct ext4_dir_entry_2 *) (&root->dotdot); 2297 de->rec_len = ext4_rec_len_to_disk( 2298 blocksize - ext4_dir_rec_len(2, NULL), blocksize); 2299 memset (&root->info, 0, sizeof(root->info)); 2300 root->info.info_length = sizeof(root->info); 2301 if (ext4_hash_in_dirent(dir)) 2302 root->info.hash_version = DX_HASH_SIPHASH; 2303 else 2304 root->info.hash_version = 2305 EXT4_SB(dir->i_sb)->s_def_hash_version; 2306 2307 entries = root->entries; 2308 dx_set_block(entries, 1); 2309 dx_set_count(entries, 1); 2310 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info))); 2311 2312 /* Initialize as for dx_probe */ 2313 fname->hinfo.hash_version = root->info.hash_version; 2314 if (fname->hinfo.hash_version <= DX_HASH_TEA) 2315 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; 2316 fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; 2317 2318 /* casefolded encrypted hashes are computed on fname setup */ 2319 if (!ext4_hash_in_dirent(dir)) { 2320 int err = ext4fs_dirhash(dir, fname_name(fname), 2321 fname_len(fname), &fname->hinfo); 2322 if (err < 0) { 2323 brelse(bh2); 2324 brelse(bh); 2325 return err; 2326 } 2327 } 2328 memset(frames, 0, sizeof(frames)); 2329 frame = frames; 2330 frame->entries = entries; 2331 frame->at = entries; 2332 frame->bh = bh; 2333 2334 retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 2335 if (retval) 2336 goto out_frames; 2337 retval = ext4_handle_dirty_dirblock(handle, dir, bh2); 2338 if (retval) 2339 goto out_frames; 2340 2341 de = do_split(handle,dir, &bh2, frame, &fname->hinfo); 2342 if (IS_ERR(de)) { 2343 retval = PTR_ERR(de); 2344 goto out_frames; 2345 } 2346 2347 retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2); 2348 out_frames: 2349 /* 2350 * Even if the block split failed, we have to properly write 2351 * out all the changes we did so far. Otherwise we can end up 2352 * with corrupted filesystem. 2353 */ 2354 if (retval) 2355 ext4_mark_inode_dirty(handle, dir); 2356 dx_release(frames); 2357 brelse(bh2); 2358 return retval; 2359 } 2360 2361 /* 2362 * ext4_add_entry() 2363 * 2364 * adds a file entry to the specified directory, using the same 2365 * semantics as ext4_find_entry(). It returns NULL if it failed. 2366 * 2367 * NOTE!! The inode part of 'de' is left at 0 - which means you 2368 * may not sleep between calling this and putting something into 2369 * the entry, as someone else might have used it while you slept. 2370 */ 2371 static int ext4_add_entry(handle_t *handle, struct dentry *dentry, 2372 struct inode *inode) 2373 { 2374 struct inode *dir = d_inode(dentry->d_parent); 2375 struct buffer_head *bh = NULL; 2376 struct ext4_dir_entry_2 *de; 2377 struct super_block *sb; 2378 struct ext4_filename fname; 2379 int retval; 2380 int dx_fallback=0; 2381 unsigned blocksize; 2382 ext4_lblk_t block, blocks; 2383 int csum_size = 0; 2384 2385 if (ext4_has_metadata_csum(inode->i_sb)) 2386 csum_size = sizeof(struct ext4_dir_entry_tail); 2387 2388 sb = dir->i_sb; 2389 blocksize = sb->s_blocksize; 2390 2391 if (fscrypt_is_nokey_name(dentry)) 2392 return -ENOKEY; 2393 2394 #if IS_ENABLED(CONFIG_UNICODE) 2395 if (sb_has_strict_encoding(sb) && IS_CASEFOLDED(dir) && 2396 utf8_validate(sb->s_encoding, &dentry->d_name)) 2397 return -EINVAL; 2398 #endif 2399 2400 retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname); 2401 if (retval) 2402 return retval; 2403 2404 if (ext4_has_inline_data(dir)) { 2405 retval = ext4_try_add_inline_entry(handle, &fname, dir, inode); 2406 if (retval < 0) 2407 goto out; 2408 if (retval == 1) { 2409 retval = 0; 2410 goto out; 2411 } 2412 } 2413 2414 if (is_dx(dir)) { 2415 retval = ext4_dx_add_entry(handle, &fname, dir, inode); 2416 if (!retval || (retval != ERR_BAD_DX_DIR)) 2417 goto out; 2418 /* Can we just ignore htree data? */ 2419 if (ext4_has_metadata_csum(sb)) { 2420 EXT4_ERROR_INODE(dir, 2421 "Directory has corrupted htree index."); 2422 retval = -EFSCORRUPTED; 2423 goto out; 2424 } 2425 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX); 2426 dx_fallback++; 2427 retval = ext4_mark_inode_dirty(handle, dir); 2428 if (unlikely(retval)) 2429 goto out; 2430 } 2431 blocks = dir->i_size >> sb->s_blocksize_bits; 2432 for (block = 0; block < blocks; block++) { 2433 bh = ext4_read_dirblock(dir, block, DIRENT); 2434 if (bh == NULL) { 2435 bh = ext4_bread(handle, dir, block, 2436 EXT4_GET_BLOCKS_CREATE); 2437 goto add_to_new_block; 2438 } 2439 if (IS_ERR(bh)) { 2440 retval = PTR_ERR(bh); 2441 bh = NULL; 2442 goto out; 2443 } 2444 retval = add_dirent_to_buf(handle, &fname, dir, inode, 2445 NULL, bh); 2446 if (retval != -ENOSPC) 2447 goto out; 2448 2449 if (blocks == 1 && !dx_fallback && 2450 ext4_has_feature_dir_index(sb)) { 2451 retval = make_indexed_dir(handle, &fname, dir, 2452 inode, bh); 2453 bh = NULL; /* make_indexed_dir releases bh */ 2454 goto out; 2455 } 2456 brelse(bh); 2457 } 2458 bh = ext4_append(handle, dir, &block); 2459 add_to_new_block: 2460 if (IS_ERR(bh)) { 2461 retval = PTR_ERR(bh); 2462 bh = NULL; 2463 goto out; 2464 } 2465 de = (struct ext4_dir_entry_2 *) bh->b_data; 2466 de->inode = 0; 2467 de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize); 2468 2469 if (csum_size) 2470 ext4_initialize_dirent_tail(bh, blocksize); 2471 2472 retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh); 2473 out: 2474 ext4_fname_free_filename(&fname); 2475 brelse(bh); 2476 if (retval == 0) 2477 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY); 2478 return retval; 2479 } 2480 2481 /* 2482 * Returns 0 for success, or a negative error value 2483 */ 2484 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname, 2485 struct inode *dir, struct inode *inode) 2486 { 2487 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 2488 struct dx_entry *entries, *at; 2489 struct buffer_head *bh; 2490 struct super_block *sb = dir->i_sb; 2491 struct ext4_dir_entry_2 *de; 2492 int restart; 2493 int err; 2494 2495 again: 2496 restart = 0; 2497 frame = dx_probe(fname, dir, NULL, frames); 2498 if (IS_ERR(frame)) 2499 return PTR_ERR(frame); 2500 entries = frame->entries; 2501 at = frame->at; 2502 bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT_HTREE); 2503 if (IS_ERR(bh)) { 2504 err = PTR_ERR(bh); 2505 bh = NULL; 2506 goto cleanup; 2507 } 2508 2509 BUFFER_TRACE(bh, "get_write_access"); 2510 err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE); 2511 if (err) 2512 goto journal_error; 2513 2514 err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh); 2515 if (err != -ENOSPC) 2516 goto cleanup; 2517 2518 err = 0; 2519 /* Block full, should compress but for now just split */ 2520 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n", 2521 dx_get_count(entries), dx_get_limit(entries))); 2522 /* Need to split index? */ 2523 if (dx_get_count(entries) == dx_get_limit(entries)) { 2524 ext4_lblk_t newblock; 2525 int levels = frame - frames + 1; 2526 unsigned int icount; 2527 int add_level = 1; 2528 struct dx_entry *entries2; 2529 struct dx_node *node2; 2530 struct buffer_head *bh2; 2531 2532 while (frame > frames) { 2533 if (dx_get_count((frame - 1)->entries) < 2534 dx_get_limit((frame - 1)->entries)) { 2535 add_level = 0; 2536 break; 2537 } 2538 frame--; /* split higher index block */ 2539 at = frame->at; 2540 entries = frame->entries; 2541 restart = 1; 2542 } 2543 if (add_level && levels == ext4_dir_htree_level(sb)) { 2544 ext4_warning(sb, "Directory (ino: %lu) index full, " 2545 "reach max htree level :%d", 2546 dir->i_ino, levels); 2547 if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) { 2548 ext4_warning(sb, "Large directory feature is " 2549 "not enabled on this " 2550 "filesystem"); 2551 } 2552 err = -ENOSPC; 2553 goto cleanup; 2554 } 2555 icount = dx_get_count(entries); 2556 bh2 = ext4_append(handle, dir, &newblock); 2557 if (IS_ERR(bh2)) { 2558 err = PTR_ERR(bh2); 2559 goto cleanup; 2560 } 2561 node2 = (struct dx_node *)(bh2->b_data); 2562 entries2 = node2->entries; 2563 memset(&node2->fake, 0, sizeof(struct fake_dirent)); 2564 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize, 2565 sb->s_blocksize); 2566 BUFFER_TRACE(frame->bh, "get_write_access"); 2567 err = ext4_journal_get_write_access(handle, sb, frame->bh, 2568 EXT4_JTR_NONE); 2569 if (err) 2570 goto journal_error; 2571 if (!add_level) { 2572 unsigned icount1 = icount/2, icount2 = icount - icount1; 2573 unsigned hash2 = dx_get_hash(entries + icount1); 2574 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n", 2575 icount1, icount2)); 2576 2577 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */ 2578 err = ext4_journal_get_write_access(handle, sb, 2579 (frame - 1)->bh, 2580 EXT4_JTR_NONE); 2581 if (err) 2582 goto journal_error; 2583 2584 memcpy((char *) entries2, (char *) (entries + icount1), 2585 icount2 * sizeof(struct dx_entry)); 2586 dx_set_count(entries, icount1); 2587 dx_set_count(entries2, icount2); 2588 dx_set_limit(entries2, dx_node_limit(dir)); 2589 2590 /* Which index block gets the new entry? */ 2591 if (at - entries >= icount1) { 2592 frame->at = at - entries - icount1 + entries2; 2593 frame->entries = entries = entries2; 2594 swap(frame->bh, bh2); 2595 } 2596 dx_insert_block((frame - 1), hash2, newblock); 2597 dxtrace(dx_show_index("node", frame->entries)); 2598 dxtrace(dx_show_index("node", 2599 ((struct dx_node *) bh2->b_data)->entries)); 2600 err = ext4_handle_dirty_dx_node(handle, dir, bh2); 2601 if (err) 2602 goto journal_error; 2603 brelse (bh2); 2604 err = ext4_handle_dirty_dx_node(handle, dir, 2605 (frame - 1)->bh); 2606 if (err) 2607 goto journal_error; 2608 err = ext4_handle_dirty_dx_node(handle, dir, 2609 frame->bh); 2610 if (restart || err) 2611 goto journal_error; 2612 } else { 2613 struct dx_root *dxroot; 2614 memcpy((char *) entries2, (char *) entries, 2615 icount * sizeof(struct dx_entry)); 2616 dx_set_limit(entries2, dx_node_limit(dir)); 2617 2618 /* Set up root */ 2619 dx_set_count(entries, 1); 2620 dx_set_block(entries + 0, newblock); 2621 dxroot = (struct dx_root *)frames[0].bh->b_data; 2622 dxroot->info.indirect_levels += 1; 2623 dxtrace(printk(KERN_DEBUG 2624 "Creating %d level index...\n", 2625 dxroot->info.indirect_levels)); 2626 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 2627 if (err) 2628 goto journal_error; 2629 err = ext4_handle_dirty_dx_node(handle, dir, bh2); 2630 brelse(bh2); 2631 restart = 1; 2632 goto journal_error; 2633 } 2634 } 2635 de = do_split(handle, dir, &bh, frame, &fname->hinfo); 2636 if (IS_ERR(de)) { 2637 err = PTR_ERR(de); 2638 goto cleanup; 2639 } 2640 err = add_dirent_to_buf(handle, fname, dir, inode, de, bh); 2641 goto cleanup; 2642 2643 journal_error: 2644 ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */ 2645 cleanup: 2646 brelse(bh); 2647 dx_release(frames); 2648 /* @restart is true means htree-path has been changed, we need to 2649 * repeat dx_probe() to find out valid htree-path 2650 */ 2651 if (restart && err == 0) 2652 goto again; 2653 return err; 2654 } 2655 2656 /* 2657 * ext4_generic_delete_entry deletes a directory entry by merging it 2658 * with the previous entry 2659 */ 2660 int ext4_generic_delete_entry(struct inode *dir, 2661 struct ext4_dir_entry_2 *de_del, 2662 struct buffer_head *bh, 2663 void *entry_buf, 2664 int buf_size, 2665 int csum_size) 2666 { 2667 struct ext4_dir_entry_2 *de, *pde; 2668 unsigned int blocksize = dir->i_sb->s_blocksize; 2669 int i; 2670 2671 i = 0; 2672 pde = NULL; 2673 de = entry_buf; 2674 while (i < buf_size - csum_size) { 2675 if (ext4_check_dir_entry(dir, NULL, de, bh, 2676 entry_buf, buf_size, i)) 2677 return -EFSCORRUPTED; 2678 if (de == de_del) { 2679 if (pde) { 2680 pde->rec_len = ext4_rec_len_to_disk( 2681 ext4_rec_len_from_disk(pde->rec_len, 2682 blocksize) + 2683 ext4_rec_len_from_disk(de->rec_len, 2684 blocksize), 2685 blocksize); 2686 2687 /* wipe entire dir_entry */ 2688 memset(de, 0, ext4_rec_len_from_disk(de->rec_len, 2689 blocksize)); 2690 } else { 2691 /* wipe dir_entry excluding the rec_len field */ 2692 de->inode = 0; 2693 memset(&de->name_len, 0, 2694 ext4_rec_len_from_disk(de->rec_len, 2695 blocksize) - 2696 offsetof(struct ext4_dir_entry_2, 2697 name_len)); 2698 } 2699 2700 inode_inc_iversion(dir); 2701 return 0; 2702 } 2703 i += ext4_rec_len_from_disk(de->rec_len, blocksize); 2704 pde = de; 2705 de = ext4_next_entry(de, blocksize); 2706 } 2707 return -ENOENT; 2708 } 2709 2710 static int ext4_delete_entry(handle_t *handle, 2711 struct inode *dir, 2712 struct ext4_dir_entry_2 *de_del, 2713 struct buffer_head *bh) 2714 { 2715 int err, csum_size = 0; 2716 2717 if (ext4_has_inline_data(dir)) { 2718 int has_inline_data = 1; 2719 err = ext4_delete_inline_entry(handle, dir, de_del, bh, 2720 &has_inline_data); 2721 if (has_inline_data) 2722 return err; 2723 } 2724 2725 if (ext4_has_metadata_csum(dir->i_sb)) 2726 csum_size = sizeof(struct ext4_dir_entry_tail); 2727 2728 BUFFER_TRACE(bh, "get_write_access"); 2729 err = ext4_journal_get_write_access(handle, dir->i_sb, bh, 2730 EXT4_JTR_NONE); 2731 if (unlikely(err)) 2732 goto out; 2733 2734 err = ext4_generic_delete_entry(dir, de_del, bh, bh->b_data, 2735 dir->i_sb->s_blocksize, csum_size); 2736 if (err) 2737 goto out; 2738 2739 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); 2740 err = ext4_handle_dirty_dirblock(handle, dir, bh); 2741 if (unlikely(err)) 2742 goto out; 2743 2744 return 0; 2745 out: 2746 if (err != -ENOENT) 2747 ext4_std_error(dir->i_sb, err); 2748 return err; 2749 } 2750 2751 /* 2752 * Set directory link count to 1 if nlinks > EXT4_LINK_MAX, or if nlinks == 2 2753 * since this indicates that nlinks count was previously 1 to avoid overflowing 2754 * the 16-bit i_links_count field on disk. Directories with i_nlink == 1 mean 2755 * that subdirectory link counts are not being maintained accurately. 2756 * 2757 * The caller has already checked for i_nlink overflow in case the DIR_LINK 2758 * feature is not enabled and returned -EMLINK. The is_dx() check is a proxy 2759 * for checking S_ISDIR(inode) (since the INODE_INDEX feature will not be set 2760 * on regular files) and to avoid creating huge/slow non-HTREE directories. 2761 */ 2762 static void ext4_inc_count(struct inode *inode) 2763 { 2764 inc_nlink(inode); 2765 if (is_dx(inode) && 2766 (inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2)) 2767 set_nlink(inode, 1); 2768 } 2769 2770 /* 2771 * If a directory had nlink == 1, then we should let it be 1. This indicates 2772 * directory has >EXT4_LINK_MAX subdirs. 2773 */ 2774 static void ext4_dec_count(struct inode *inode) 2775 { 2776 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2) 2777 drop_nlink(inode); 2778 } 2779 2780 2781 /* 2782 * Add non-directory inode to a directory. On success, the inode reference is 2783 * consumed by dentry is instantiation. This is also indicated by clearing of 2784 * *inodep pointer. On failure, the caller is responsible for dropping the 2785 * inode reference in the safe context. 2786 */ 2787 static int ext4_add_nondir(handle_t *handle, 2788 struct dentry *dentry, struct inode **inodep) 2789 { 2790 struct inode *dir = d_inode(dentry->d_parent); 2791 struct inode *inode = *inodep; 2792 int err = ext4_add_entry(handle, dentry, inode); 2793 if (!err) { 2794 err = ext4_mark_inode_dirty(handle, inode); 2795 if (IS_DIRSYNC(dir)) 2796 ext4_handle_sync(handle); 2797 d_instantiate_new(dentry, inode); 2798 *inodep = NULL; 2799 return err; 2800 } 2801 drop_nlink(inode); 2802 ext4_mark_inode_dirty(handle, inode); 2803 ext4_orphan_add(handle, inode); 2804 unlock_new_inode(inode); 2805 return err; 2806 } 2807 2808 /* 2809 * By the time this is called, we already have created 2810 * the directory cache entry for the new file, but it 2811 * is so far negative - it has no inode. 2812 * 2813 * If the create succeeds, we fill in the inode information 2814 * with d_instantiate(). 2815 */ 2816 static int ext4_create(struct mnt_idmap *idmap, struct inode *dir, 2817 struct dentry *dentry, umode_t mode, bool excl) 2818 { 2819 handle_t *handle; 2820 struct inode *inode; 2821 int err, credits, retries = 0; 2822 2823 err = dquot_initialize(dir); 2824 if (err) 2825 return err; 2826 2827 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2828 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2829 retry: 2830 inode = ext4_new_inode_start_handle(idmap, dir, mode, &dentry->d_name, 2831 0, NULL, EXT4_HT_DIR, credits); 2832 handle = ext4_journal_current_handle(); 2833 err = PTR_ERR(inode); 2834 if (!IS_ERR(inode)) { 2835 inode->i_op = &ext4_file_inode_operations; 2836 inode->i_fop = &ext4_file_operations; 2837 ext4_set_aops(inode); 2838 err = ext4_add_nondir(handle, dentry, &inode); 2839 if (!err) 2840 ext4_fc_track_create(handle, dentry); 2841 } 2842 if (handle) 2843 ext4_journal_stop(handle); 2844 if (!IS_ERR_OR_NULL(inode)) 2845 iput(inode); 2846 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2847 goto retry; 2848 return err; 2849 } 2850 2851 static int ext4_mknod(struct mnt_idmap *idmap, struct inode *dir, 2852 struct dentry *dentry, umode_t mode, dev_t rdev) 2853 { 2854 handle_t *handle; 2855 struct inode *inode; 2856 int err, credits, retries = 0; 2857 2858 err = dquot_initialize(dir); 2859 if (err) 2860 return err; 2861 2862 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2863 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2864 retry: 2865 inode = ext4_new_inode_start_handle(idmap, dir, mode, &dentry->d_name, 2866 0, NULL, EXT4_HT_DIR, credits); 2867 handle = ext4_journal_current_handle(); 2868 err = PTR_ERR(inode); 2869 if (!IS_ERR(inode)) { 2870 init_special_inode(inode, inode->i_mode, rdev); 2871 inode->i_op = &ext4_special_inode_operations; 2872 err = ext4_add_nondir(handle, dentry, &inode); 2873 if (!err) 2874 ext4_fc_track_create(handle, dentry); 2875 } 2876 if (handle) 2877 ext4_journal_stop(handle); 2878 if (!IS_ERR_OR_NULL(inode)) 2879 iput(inode); 2880 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2881 goto retry; 2882 return err; 2883 } 2884 2885 static int ext4_tmpfile(struct mnt_idmap *idmap, struct inode *dir, 2886 struct file *file, umode_t mode) 2887 { 2888 handle_t *handle; 2889 struct inode *inode; 2890 int err, retries = 0; 2891 2892 err = dquot_initialize(dir); 2893 if (err) 2894 return err; 2895 2896 retry: 2897 inode = ext4_new_inode_start_handle(idmap, dir, mode, 2898 NULL, 0, NULL, 2899 EXT4_HT_DIR, 2900 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) + 2901 4 + EXT4_XATTR_TRANS_BLOCKS); 2902 handle = ext4_journal_current_handle(); 2903 err = PTR_ERR(inode); 2904 if (!IS_ERR(inode)) { 2905 inode->i_op = &ext4_file_inode_operations; 2906 inode->i_fop = &ext4_file_operations; 2907 ext4_set_aops(inode); 2908 d_tmpfile(file, inode); 2909 err = ext4_orphan_add(handle, inode); 2910 if (err) 2911 goto err_unlock_inode; 2912 mark_inode_dirty(inode); 2913 unlock_new_inode(inode); 2914 } 2915 if (handle) 2916 ext4_journal_stop(handle); 2917 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2918 goto retry; 2919 return finish_open_simple(file, err); 2920 err_unlock_inode: 2921 ext4_journal_stop(handle); 2922 unlock_new_inode(inode); 2923 return err; 2924 } 2925 2926 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode, 2927 struct ext4_dir_entry_2 *de, 2928 int blocksize, int csum_size, 2929 unsigned int parent_ino, int dotdot_real_len) 2930 { 2931 de->inode = cpu_to_le32(inode->i_ino); 2932 de->name_len = 1; 2933 de->rec_len = ext4_rec_len_to_disk(ext4_dir_rec_len(de->name_len, NULL), 2934 blocksize); 2935 strcpy(de->name, "."); 2936 ext4_set_de_type(inode->i_sb, de, S_IFDIR); 2937 2938 de = ext4_next_entry(de, blocksize); 2939 de->inode = cpu_to_le32(parent_ino); 2940 de->name_len = 2; 2941 if (!dotdot_real_len) 2942 de->rec_len = ext4_rec_len_to_disk(blocksize - 2943 (csum_size + ext4_dir_rec_len(1, NULL)), 2944 blocksize); 2945 else 2946 de->rec_len = ext4_rec_len_to_disk( 2947 ext4_dir_rec_len(de->name_len, NULL), 2948 blocksize); 2949 strcpy(de->name, ".."); 2950 ext4_set_de_type(inode->i_sb, de, S_IFDIR); 2951 2952 return ext4_next_entry(de, blocksize); 2953 } 2954 2955 int ext4_init_new_dir(handle_t *handle, struct inode *dir, 2956 struct inode *inode) 2957 { 2958 struct buffer_head *dir_block = NULL; 2959 struct ext4_dir_entry_2 *de; 2960 ext4_lblk_t block = 0; 2961 unsigned int blocksize = dir->i_sb->s_blocksize; 2962 int csum_size = 0; 2963 int err; 2964 2965 if (ext4_has_metadata_csum(dir->i_sb)) 2966 csum_size = sizeof(struct ext4_dir_entry_tail); 2967 2968 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) { 2969 err = ext4_try_create_inline_dir(handle, dir, inode); 2970 if (err < 0 && err != -ENOSPC) 2971 goto out; 2972 if (!err) 2973 goto out; 2974 } 2975 2976 inode->i_size = 0; 2977 dir_block = ext4_append(handle, inode, &block); 2978 if (IS_ERR(dir_block)) 2979 return PTR_ERR(dir_block); 2980 de = (struct ext4_dir_entry_2 *)dir_block->b_data; 2981 ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0); 2982 set_nlink(inode, 2); 2983 if (csum_size) 2984 ext4_initialize_dirent_tail(dir_block, blocksize); 2985 2986 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata"); 2987 err = ext4_handle_dirty_dirblock(handle, inode, dir_block); 2988 if (err) 2989 goto out; 2990 set_buffer_verified(dir_block); 2991 out: 2992 brelse(dir_block); 2993 return err; 2994 } 2995 2996 static int ext4_mkdir(struct mnt_idmap *idmap, struct inode *dir, 2997 struct dentry *dentry, umode_t mode) 2998 { 2999 handle_t *handle; 3000 struct inode *inode; 3001 int err, err2 = 0, credits, retries = 0; 3002 3003 if (EXT4_DIR_LINK_MAX(dir)) 3004 return -EMLINK; 3005 3006 err = dquot_initialize(dir); 3007 if (err) 3008 return err; 3009 3010 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3011 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 3012 retry: 3013 inode = ext4_new_inode_start_handle(idmap, dir, S_IFDIR | mode, 3014 &dentry->d_name, 3015 0, NULL, EXT4_HT_DIR, credits); 3016 handle = ext4_journal_current_handle(); 3017 err = PTR_ERR(inode); 3018 if (IS_ERR(inode)) 3019 goto out_stop; 3020 3021 inode->i_op = &ext4_dir_inode_operations; 3022 inode->i_fop = &ext4_dir_operations; 3023 err = ext4_init_new_dir(handle, dir, inode); 3024 if (err) 3025 goto out_clear_inode; 3026 err = ext4_mark_inode_dirty(handle, inode); 3027 if (!err) 3028 err = ext4_add_entry(handle, dentry, inode); 3029 if (err) { 3030 out_clear_inode: 3031 clear_nlink(inode); 3032 ext4_orphan_add(handle, inode); 3033 unlock_new_inode(inode); 3034 err2 = ext4_mark_inode_dirty(handle, inode); 3035 if (unlikely(err2)) 3036 err = err2; 3037 ext4_journal_stop(handle); 3038 iput(inode); 3039 goto out_retry; 3040 } 3041 ext4_inc_count(dir); 3042 3043 ext4_update_dx_flag(dir); 3044 err = ext4_mark_inode_dirty(handle, dir); 3045 if (err) 3046 goto out_clear_inode; 3047 d_instantiate_new(dentry, inode); 3048 ext4_fc_track_create(handle, dentry); 3049 if (IS_DIRSYNC(dir)) 3050 ext4_handle_sync(handle); 3051 3052 out_stop: 3053 if (handle) 3054 ext4_journal_stop(handle); 3055 out_retry: 3056 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 3057 goto retry; 3058 return err; 3059 } 3060 3061 /* 3062 * routine to check that the specified directory is empty (for rmdir) 3063 */ 3064 bool ext4_empty_dir(struct inode *inode) 3065 { 3066 unsigned int offset; 3067 struct buffer_head *bh; 3068 struct ext4_dir_entry_2 *de; 3069 struct super_block *sb; 3070 3071 if (ext4_has_inline_data(inode)) { 3072 int has_inline_data = 1; 3073 int ret; 3074 3075 ret = empty_inline_dir(inode, &has_inline_data); 3076 if (has_inline_data) 3077 return ret; 3078 } 3079 3080 sb = inode->i_sb; 3081 if (inode->i_size < ext4_dir_rec_len(1, NULL) + 3082 ext4_dir_rec_len(2, NULL)) { 3083 EXT4_ERROR_INODE(inode, "invalid size"); 3084 return false; 3085 } 3086 /* The first directory block must not be a hole, 3087 * so treat it as DIRENT_HTREE 3088 */ 3089 bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE); 3090 if (IS_ERR(bh)) 3091 return false; 3092 3093 de = (struct ext4_dir_entry_2 *) bh->b_data; 3094 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size, 3095 0) || 3096 le32_to_cpu(de->inode) != inode->i_ino || strcmp(".", de->name)) { 3097 ext4_warning_inode(inode, "directory missing '.'"); 3098 brelse(bh); 3099 return false; 3100 } 3101 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); 3102 de = ext4_next_entry(de, sb->s_blocksize); 3103 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size, 3104 offset) || 3105 le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) { 3106 ext4_warning_inode(inode, "directory missing '..'"); 3107 brelse(bh); 3108 return false; 3109 } 3110 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); 3111 while (offset < inode->i_size) { 3112 if (!(offset & (sb->s_blocksize - 1))) { 3113 unsigned int lblock; 3114 brelse(bh); 3115 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb); 3116 bh = ext4_read_dirblock(inode, lblock, EITHER); 3117 if (bh == NULL) { 3118 offset += sb->s_blocksize; 3119 continue; 3120 } 3121 if (IS_ERR(bh)) 3122 return false; 3123 } 3124 de = (struct ext4_dir_entry_2 *) (bh->b_data + 3125 (offset & (sb->s_blocksize - 1))); 3126 if (ext4_check_dir_entry(inode, NULL, de, bh, 3127 bh->b_data, bh->b_size, offset) || 3128 le32_to_cpu(de->inode)) { 3129 brelse(bh); 3130 return false; 3131 } 3132 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); 3133 } 3134 brelse(bh); 3135 return true; 3136 } 3137 3138 static int ext4_rmdir(struct inode *dir, struct dentry *dentry) 3139 { 3140 int retval; 3141 struct inode *inode; 3142 struct buffer_head *bh; 3143 struct ext4_dir_entry_2 *de; 3144 handle_t *handle = NULL; 3145 3146 if (unlikely(ext4_forced_shutdown(dir->i_sb))) 3147 return -EIO; 3148 3149 /* Initialize quotas before so that eventual writes go in 3150 * separate transaction */ 3151 retval = dquot_initialize(dir); 3152 if (retval) 3153 return retval; 3154 retval = dquot_initialize(d_inode(dentry)); 3155 if (retval) 3156 return retval; 3157 3158 retval = -ENOENT; 3159 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); 3160 if (IS_ERR(bh)) 3161 return PTR_ERR(bh); 3162 if (!bh) 3163 goto end_rmdir; 3164 3165 inode = d_inode(dentry); 3166 3167 retval = -EFSCORRUPTED; 3168 if (le32_to_cpu(de->inode) != inode->i_ino) 3169 goto end_rmdir; 3170 3171 retval = -ENOTEMPTY; 3172 if (!ext4_empty_dir(inode)) 3173 goto end_rmdir; 3174 3175 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3176 EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); 3177 if (IS_ERR(handle)) { 3178 retval = PTR_ERR(handle); 3179 handle = NULL; 3180 goto end_rmdir; 3181 } 3182 3183 if (IS_DIRSYNC(dir)) 3184 ext4_handle_sync(handle); 3185 3186 retval = ext4_delete_entry(handle, dir, de, bh); 3187 if (retval) 3188 goto end_rmdir; 3189 if (!EXT4_DIR_LINK_EMPTY(inode)) 3190 ext4_warning_inode(inode, 3191 "empty directory '%.*s' has too many links (%u)", 3192 dentry->d_name.len, dentry->d_name.name, 3193 inode->i_nlink); 3194 inode_inc_iversion(inode); 3195 clear_nlink(inode); 3196 /* There's no need to set i_disksize: the fact that i_nlink is 3197 * zero will ensure that the right thing happens during any 3198 * recovery. */ 3199 inode->i_size = 0; 3200 ext4_orphan_add(handle, inode); 3201 inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir)); 3202 inode_set_ctime_current(inode); 3203 retval = ext4_mark_inode_dirty(handle, inode); 3204 if (retval) 3205 goto end_rmdir; 3206 ext4_dec_count(dir); 3207 ext4_update_dx_flag(dir); 3208 ext4_fc_track_unlink(handle, dentry); 3209 retval = ext4_mark_inode_dirty(handle, dir); 3210 3211 #if IS_ENABLED(CONFIG_UNICODE) 3212 /* VFS negative dentries are incompatible with Encoding and 3213 * Case-insensitiveness. Eventually we'll want avoid 3214 * invalidating the dentries here, alongside with returning the 3215 * negative dentries at ext4_lookup(), when it is better 3216 * supported by the VFS for the CI case. 3217 */ 3218 if (IS_CASEFOLDED(dir)) 3219 d_invalidate(dentry); 3220 #endif 3221 3222 end_rmdir: 3223 brelse(bh); 3224 if (handle) 3225 ext4_journal_stop(handle); 3226 return retval; 3227 } 3228 3229 int __ext4_unlink(struct inode *dir, const struct qstr *d_name, 3230 struct inode *inode, 3231 struct dentry *dentry /* NULL during fast_commit recovery */) 3232 { 3233 int retval = -ENOENT; 3234 struct buffer_head *bh; 3235 struct ext4_dir_entry_2 *de; 3236 handle_t *handle; 3237 int skip_remove_dentry = 0; 3238 3239 /* 3240 * Keep this outside the transaction; it may have to set up the 3241 * directory's encryption key, which isn't GFP_NOFS-safe. 3242 */ 3243 bh = ext4_find_entry(dir, d_name, &de, NULL); 3244 if (IS_ERR(bh)) 3245 return PTR_ERR(bh); 3246 3247 if (!bh) 3248 return -ENOENT; 3249 3250 if (le32_to_cpu(de->inode) != inode->i_ino) { 3251 /* 3252 * It's okay if we find dont find dentry which matches 3253 * the inode. That's because it might have gotten 3254 * renamed to a different inode number 3255 */ 3256 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY) 3257 skip_remove_dentry = 1; 3258 else 3259 goto out_bh; 3260 } 3261 3262 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3263 EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); 3264 if (IS_ERR(handle)) { 3265 retval = PTR_ERR(handle); 3266 goto out_bh; 3267 } 3268 3269 if (IS_DIRSYNC(dir)) 3270 ext4_handle_sync(handle); 3271 3272 if (!skip_remove_dentry) { 3273 retval = ext4_delete_entry(handle, dir, de, bh); 3274 if (retval) 3275 goto out_handle; 3276 inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir)); 3277 ext4_update_dx_flag(dir); 3278 retval = ext4_mark_inode_dirty(handle, dir); 3279 if (retval) 3280 goto out_handle; 3281 } else { 3282 retval = 0; 3283 } 3284 if (inode->i_nlink == 0) 3285 ext4_warning_inode(inode, "Deleting file '%.*s' with no links", 3286 d_name->len, d_name->name); 3287 else 3288 drop_nlink(inode); 3289 if (!inode->i_nlink) 3290 ext4_orphan_add(handle, inode); 3291 inode_set_ctime_current(inode); 3292 retval = ext4_mark_inode_dirty(handle, inode); 3293 if (dentry && !retval) 3294 ext4_fc_track_unlink(handle, dentry); 3295 out_handle: 3296 ext4_journal_stop(handle); 3297 out_bh: 3298 brelse(bh); 3299 return retval; 3300 } 3301 3302 static int ext4_unlink(struct inode *dir, struct dentry *dentry) 3303 { 3304 int retval; 3305 3306 if (unlikely(ext4_forced_shutdown(dir->i_sb))) 3307 return -EIO; 3308 3309 trace_ext4_unlink_enter(dir, dentry); 3310 /* 3311 * Initialize quotas before so that eventual writes go 3312 * in separate transaction 3313 */ 3314 retval = dquot_initialize(dir); 3315 if (retval) 3316 goto out_trace; 3317 retval = dquot_initialize(d_inode(dentry)); 3318 if (retval) 3319 goto out_trace; 3320 3321 retval = __ext4_unlink(dir, &dentry->d_name, d_inode(dentry), dentry); 3322 #if IS_ENABLED(CONFIG_UNICODE) 3323 /* VFS negative dentries are incompatible with Encoding and 3324 * Case-insensitiveness. Eventually we'll want avoid 3325 * invalidating the dentries here, alongside with returning the 3326 * negative dentries at ext4_lookup(), when it is better 3327 * supported by the VFS for the CI case. 3328 */ 3329 if (IS_CASEFOLDED(dir)) 3330 d_invalidate(dentry); 3331 #endif 3332 3333 out_trace: 3334 trace_ext4_unlink_exit(dentry, retval); 3335 return retval; 3336 } 3337 3338 static int ext4_init_symlink_block(handle_t *handle, struct inode *inode, 3339 struct fscrypt_str *disk_link) 3340 { 3341 struct buffer_head *bh; 3342 char *kaddr; 3343 int err = 0; 3344 3345 bh = ext4_bread(handle, inode, 0, EXT4_GET_BLOCKS_CREATE); 3346 if (IS_ERR(bh)) 3347 return PTR_ERR(bh); 3348 3349 BUFFER_TRACE(bh, "get_write_access"); 3350 err = ext4_journal_get_write_access(handle, inode->i_sb, bh, EXT4_JTR_NONE); 3351 if (err) 3352 goto out; 3353 3354 kaddr = (char *)bh->b_data; 3355 memcpy(kaddr, disk_link->name, disk_link->len); 3356 inode->i_size = disk_link->len - 1; 3357 EXT4_I(inode)->i_disksize = inode->i_size; 3358 err = ext4_handle_dirty_metadata(handle, inode, bh); 3359 out: 3360 brelse(bh); 3361 return err; 3362 } 3363 3364 static int ext4_symlink(struct mnt_idmap *idmap, struct inode *dir, 3365 struct dentry *dentry, const char *symname) 3366 { 3367 handle_t *handle; 3368 struct inode *inode; 3369 int err, len = strlen(symname); 3370 int credits; 3371 struct fscrypt_str disk_link; 3372 int retries = 0; 3373 3374 if (unlikely(ext4_forced_shutdown(dir->i_sb))) 3375 return -EIO; 3376 3377 err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize, 3378 &disk_link); 3379 if (err) 3380 return err; 3381 3382 err = dquot_initialize(dir); 3383 if (err) 3384 return err; 3385 3386 /* 3387 * EXT4_INDEX_EXTRA_TRANS_BLOCKS for addition of entry into the 3388 * directory. +3 for inode, inode bitmap, group descriptor allocation. 3389 * EXT4_DATA_TRANS_BLOCKS for the data block allocation and 3390 * modification. 3391 */ 3392 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3393 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3; 3394 retry: 3395 inode = ext4_new_inode_start_handle(idmap, dir, S_IFLNK|S_IRWXUGO, 3396 &dentry->d_name, 0, NULL, 3397 EXT4_HT_DIR, credits); 3398 handle = ext4_journal_current_handle(); 3399 if (IS_ERR(inode)) { 3400 if (handle) 3401 ext4_journal_stop(handle); 3402 err = PTR_ERR(inode); 3403 goto out_retry; 3404 } 3405 3406 if (IS_ENCRYPTED(inode)) { 3407 err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link); 3408 if (err) 3409 goto err_drop_inode; 3410 inode->i_op = &ext4_encrypted_symlink_inode_operations; 3411 } else { 3412 if ((disk_link.len > EXT4_N_BLOCKS * 4)) { 3413 inode->i_op = &ext4_symlink_inode_operations; 3414 } else { 3415 inode->i_op = &ext4_fast_symlink_inode_operations; 3416 inode->i_link = (char *)&EXT4_I(inode)->i_data; 3417 } 3418 } 3419 3420 if ((disk_link.len > EXT4_N_BLOCKS * 4)) { 3421 /* alloc symlink block and fill it */ 3422 err = ext4_init_symlink_block(handle, inode, &disk_link); 3423 if (err) 3424 goto err_drop_inode; 3425 } else { 3426 /* clear the extent format for fast symlink */ 3427 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS); 3428 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name, 3429 disk_link.len); 3430 inode->i_size = disk_link.len - 1; 3431 EXT4_I(inode)->i_disksize = inode->i_size; 3432 } 3433 err = ext4_add_nondir(handle, dentry, &inode); 3434 if (handle) 3435 ext4_journal_stop(handle); 3436 iput(inode); 3437 goto out_retry; 3438 3439 err_drop_inode: 3440 clear_nlink(inode); 3441 ext4_mark_inode_dirty(handle, inode); 3442 ext4_orphan_add(handle, inode); 3443 unlock_new_inode(inode); 3444 if (handle) 3445 ext4_journal_stop(handle); 3446 iput(inode); 3447 out_retry: 3448 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 3449 goto retry; 3450 if (disk_link.name != (unsigned char *)symname) 3451 kfree(disk_link.name); 3452 return err; 3453 } 3454 3455 int __ext4_link(struct inode *dir, struct inode *inode, struct dentry *dentry) 3456 { 3457 handle_t *handle; 3458 int err, retries = 0; 3459 retry: 3460 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3461 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3462 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1); 3463 if (IS_ERR(handle)) 3464 return PTR_ERR(handle); 3465 3466 if (IS_DIRSYNC(dir)) 3467 ext4_handle_sync(handle); 3468 3469 inode_set_ctime_current(inode); 3470 ext4_inc_count(inode); 3471 ihold(inode); 3472 3473 err = ext4_add_entry(handle, dentry, inode); 3474 if (!err) { 3475 err = ext4_mark_inode_dirty(handle, inode); 3476 /* this can happen only for tmpfile being 3477 * linked the first time 3478 */ 3479 if (inode->i_nlink == 1) 3480 ext4_orphan_del(handle, inode); 3481 d_instantiate(dentry, inode); 3482 ext4_fc_track_link(handle, dentry); 3483 } else { 3484 drop_nlink(inode); 3485 iput(inode); 3486 } 3487 ext4_journal_stop(handle); 3488 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 3489 goto retry; 3490 return err; 3491 } 3492 3493 static int ext4_link(struct dentry *old_dentry, 3494 struct inode *dir, struct dentry *dentry) 3495 { 3496 struct inode *inode = d_inode(old_dentry); 3497 int err; 3498 3499 if (inode->i_nlink >= EXT4_LINK_MAX) 3500 return -EMLINK; 3501 3502 err = fscrypt_prepare_link(old_dentry, dir, dentry); 3503 if (err) 3504 return err; 3505 3506 if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) && 3507 (!projid_eq(EXT4_I(dir)->i_projid, 3508 EXT4_I(old_dentry->d_inode)->i_projid))) 3509 return -EXDEV; 3510 3511 err = dquot_initialize(dir); 3512 if (err) 3513 return err; 3514 return __ext4_link(dir, inode, dentry); 3515 } 3516 3517 /* 3518 * Try to find buffer head where contains the parent block. 3519 * It should be the inode block if it is inlined or the 1st block 3520 * if it is a normal dir. 3521 */ 3522 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle, 3523 struct inode *inode, 3524 int *retval, 3525 struct ext4_dir_entry_2 **parent_de, 3526 int *inlined) 3527 { 3528 struct buffer_head *bh; 3529 3530 if (!ext4_has_inline_data(inode)) { 3531 struct ext4_dir_entry_2 *de; 3532 unsigned int offset; 3533 3534 /* The first directory block must not be a hole, so 3535 * treat it as DIRENT_HTREE 3536 */ 3537 bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE); 3538 if (IS_ERR(bh)) { 3539 *retval = PTR_ERR(bh); 3540 return NULL; 3541 } 3542 3543 de = (struct ext4_dir_entry_2 *) bh->b_data; 3544 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, 3545 bh->b_size, 0) || 3546 le32_to_cpu(de->inode) != inode->i_ino || 3547 strcmp(".", de->name)) { 3548 EXT4_ERROR_INODE(inode, "directory missing '.'"); 3549 brelse(bh); 3550 *retval = -EFSCORRUPTED; 3551 return NULL; 3552 } 3553 offset = ext4_rec_len_from_disk(de->rec_len, 3554 inode->i_sb->s_blocksize); 3555 de = ext4_next_entry(de, inode->i_sb->s_blocksize); 3556 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, 3557 bh->b_size, offset) || 3558 le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) { 3559 EXT4_ERROR_INODE(inode, "directory missing '..'"); 3560 brelse(bh); 3561 *retval = -EFSCORRUPTED; 3562 return NULL; 3563 } 3564 *parent_de = de; 3565 3566 return bh; 3567 } 3568 3569 *inlined = 1; 3570 return ext4_get_first_inline_block(inode, parent_de, retval); 3571 } 3572 3573 struct ext4_renament { 3574 struct inode *dir; 3575 struct dentry *dentry; 3576 struct inode *inode; 3577 bool is_dir; 3578 int dir_nlink_delta; 3579 3580 /* entry for "dentry" */ 3581 struct buffer_head *bh; 3582 struct ext4_dir_entry_2 *de; 3583 int inlined; 3584 3585 /* entry for ".." in inode if it's a directory */ 3586 struct buffer_head *dir_bh; 3587 struct ext4_dir_entry_2 *parent_de; 3588 int dir_inlined; 3589 }; 3590 3591 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent, bool is_cross) 3592 { 3593 int retval; 3594 3595 ent->is_dir = true; 3596 if (!is_cross) 3597 return 0; 3598 3599 ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode, 3600 &retval, &ent->parent_de, 3601 &ent->dir_inlined); 3602 if (!ent->dir_bh) 3603 return retval; 3604 if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino) 3605 return -EFSCORRUPTED; 3606 BUFFER_TRACE(ent->dir_bh, "get_write_access"); 3607 return ext4_journal_get_write_access(handle, ent->dir->i_sb, 3608 ent->dir_bh, EXT4_JTR_NONE); 3609 } 3610 3611 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent, 3612 unsigned dir_ino) 3613 { 3614 int retval; 3615 3616 if (!ent->dir_bh) 3617 return 0; 3618 3619 ent->parent_de->inode = cpu_to_le32(dir_ino); 3620 BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata"); 3621 if (!ent->dir_inlined) { 3622 if (is_dx(ent->inode)) { 3623 retval = ext4_handle_dirty_dx_node(handle, 3624 ent->inode, 3625 ent->dir_bh); 3626 } else { 3627 retval = ext4_handle_dirty_dirblock(handle, ent->inode, 3628 ent->dir_bh); 3629 } 3630 } else { 3631 retval = ext4_mark_inode_dirty(handle, ent->inode); 3632 } 3633 if (retval) { 3634 ext4_std_error(ent->dir->i_sb, retval); 3635 return retval; 3636 } 3637 return 0; 3638 } 3639 3640 static int ext4_setent(handle_t *handle, struct ext4_renament *ent, 3641 unsigned ino, unsigned file_type) 3642 { 3643 int retval, retval2; 3644 3645 BUFFER_TRACE(ent->bh, "get write access"); 3646 retval = ext4_journal_get_write_access(handle, ent->dir->i_sb, ent->bh, 3647 EXT4_JTR_NONE); 3648 if (retval) 3649 return retval; 3650 ent->de->inode = cpu_to_le32(ino); 3651 if (ext4_has_feature_filetype(ent->dir->i_sb)) 3652 ent->de->file_type = file_type; 3653 inode_inc_iversion(ent->dir); 3654 inode_set_mtime_to_ts(ent->dir, inode_set_ctime_current(ent->dir)); 3655 retval = ext4_mark_inode_dirty(handle, ent->dir); 3656 BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata"); 3657 if (!ent->inlined) { 3658 retval2 = ext4_handle_dirty_dirblock(handle, ent->dir, ent->bh); 3659 if (unlikely(retval2)) { 3660 ext4_std_error(ent->dir->i_sb, retval2); 3661 return retval2; 3662 } 3663 } 3664 return retval; 3665 } 3666 3667 static void ext4_resetent(handle_t *handle, struct ext4_renament *ent, 3668 unsigned ino, unsigned file_type) 3669 { 3670 struct ext4_renament old = *ent; 3671 int retval = 0; 3672 3673 /* 3674 * old->de could have moved from under us during make indexed dir, 3675 * so the old->de may no longer valid and need to find it again 3676 * before reset old inode info. 3677 */ 3678 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, 3679 &old.inlined); 3680 if (IS_ERR(old.bh)) 3681 retval = PTR_ERR(old.bh); 3682 if (!old.bh) 3683 retval = -ENOENT; 3684 if (retval) { 3685 ext4_std_error(old.dir->i_sb, retval); 3686 return; 3687 } 3688 3689 ext4_setent(handle, &old, ino, file_type); 3690 brelse(old.bh); 3691 } 3692 3693 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir, 3694 const struct qstr *d_name) 3695 { 3696 int retval = -ENOENT; 3697 struct buffer_head *bh; 3698 struct ext4_dir_entry_2 *de; 3699 3700 bh = ext4_find_entry(dir, d_name, &de, NULL); 3701 if (IS_ERR(bh)) 3702 return PTR_ERR(bh); 3703 if (bh) { 3704 retval = ext4_delete_entry(handle, dir, de, bh); 3705 brelse(bh); 3706 } 3707 return retval; 3708 } 3709 3710 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent, 3711 int force_reread) 3712 { 3713 int retval; 3714 /* 3715 * ent->de could have moved from under us during htree split, so make 3716 * sure that we are deleting the right entry. We might also be pointing 3717 * to a stale entry in the unused part of ent->bh so just checking inum 3718 * and the name isn't enough. 3719 */ 3720 if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino || 3721 ent->de->name_len != ent->dentry->d_name.len || 3722 strncmp(ent->de->name, ent->dentry->d_name.name, 3723 ent->de->name_len) || 3724 force_reread) { 3725 retval = ext4_find_delete_entry(handle, ent->dir, 3726 &ent->dentry->d_name); 3727 } else { 3728 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh); 3729 if (retval == -ENOENT) { 3730 retval = ext4_find_delete_entry(handle, ent->dir, 3731 &ent->dentry->d_name); 3732 } 3733 } 3734 3735 if (retval) { 3736 ext4_warning_inode(ent->dir, 3737 "Deleting old file: nlink %d, error=%d", 3738 ent->dir->i_nlink, retval); 3739 } 3740 } 3741 3742 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent) 3743 { 3744 if (ent->dir_nlink_delta) { 3745 if (ent->dir_nlink_delta == -1) 3746 ext4_dec_count(ent->dir); 3747 else 3748 ext4_inc_count(ent->dir); 3749 ext4_mark_inode_dirty(handle, ent->dir); 3750 } 3751 } 3752 3753 static struct inode *ext4_whiteout_for_rename(struct mnt_idmap *idmap, 3754 struct ext4_renament *ent, 3755 int credits, handle_t **h) 3756 { 3757 struct inode *wh; 3758 handle_t *handle; 3759 int retries = 0; 3760 3761 /* 3762 * for inode block, sb block, group summaries, 3763 * and inode bitmap 3764 */ 3765 credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) + 3766 EXT4_XATTR_TRANS_BLOCKS + 4); 3767 retry: 3768 wh = ext4_new_inode_start_handle(idmap, ent->dir, 3769 S_IFCHR | WHITEOUT_MODE, 3770 &ent->dentry->d_name, 0, NULL, 3771 EXT4_HT_DIR, credits); 3772 3773 handle = ext4_journal_current_handle(); 3774 if (IS_ERR(wh)) { 3775 if (handle) 3776 ext4_journal_stop(handle); 3777 if (PTR_ERR(wh) == -ENOSPC && 3778 ext4_should_retry_alloc(ent->dir->i_sb, &retries)) 3779 goto retry; 3780 } else { 3781 *h = handle; 3782 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV); 3783 wh->i_op = &ext4_special_inode_operations; 3784 } 3785 return wh; 3786 } 3787 3788 /* 3789 * Anybody can rename anything with this: the permission checks are left to the 3790 * higher-level routines. 3791 * 3792 * n.b. old_{dentry,inode) refers to the source dentry/inode 3793 * while new_{dentry,inode) refers to the destination dentry/inode 3794 * This comes from rename(const char *oldpath, const char *newpath) 3795 */ 3796 static int ext4_rename(struct mnt_idmap *idmap, struct inode *old_dir, 3797 struct dentry *old_dentry, struct inode *new_dir, 3798 struct dentry *new_dentry, unsigned int flags) 3799 { 3800 handle_t *handle = NULL; 3801 struct ext4_renament old = { 3802 .dir = old_dir, 3803 .dentry = old_dentry, 3804 .inode = d_inode(old_dentry), 3805 }; 3806 struct ext4_renament new = { 3807 .dir = new_dir, 3808 .dentry = new_dentry, 3809 .inode = d_inode(new_dentry), 3810 }; 3811 int force_reread; 3812 int retval; 3813 struct inode *whiteout = NULL; 3814 int credits; 3815 u8 old_file_type; 3816 3817 if (new.inode && new.inode->i_nlink == 0) { 3818 EXT4_ERROR_INODE(new.inode, 3819 "target of rename is already freed"); 3820 return -EFSCORRUPTED; 3821 } 3822 3823 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) && 3824 (!projid_eq(EXT4_I(new_dir)->i_projid, 3825 EXT4_I(old_dentry->d_inode)->i_projid))) 3826 return -EXDEV; 3827 3828 retval = dquot_initialize(old.dir); 3829 if (retval) 3830 return retval; 3831 retval = dquot_initialize(old.inode); 3832 if (retval) 3833 return retval; 3834 retval = dquot_initialize(new.dir); 3835 if (retval) 3836 return retval; 3837 3838 /* Initialize quotas before so that eventual writes go 3839 * in separate transaction */ 3840 if (new.inode) { 3841 retval = dquot_initialize(new.inode); 3842 if (retval) 3843 return retval; 3844 } 3845 3846 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, 3847 &old.inlined); 3848 if (IS_ERR(old.bh)) 3849 return PTR_ERR(old.bh); 3850 3851 /* 3852 * Check for inode number is _not_ due to possible IO errors. 3853 * We might rmdir the source, keep it as pwd of some process 3854 * and merrily kill the link to whatever was created under the 3855 * same name. Goodbye sticky bit ;-< 3856 */ 3857 retval = -ENOENT; 3858 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino) 3859 goto release_bh; 3860 3861 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, 3862 &new.de, &new.inlined); 3863 if (IS_ERR(new.bh)) { 3864 retval = PTR_ERR(new.bh); 3865 new.bh = NULL; 3866 goto release_bh; 3867 } 3868 if (new.bh) { 3869 if (!new.inode) { 3870 brelse(new.bh); 3871 new.bh = NULL; 3872 } 3873 } 3874 if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC)) 3875 ext4_alloc_da_blocks(old.inode); 3876 3877 credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + 3878 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2); 3879 if (!(flags & RENAME_WHITEOUT)) { 3880 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits); 3881 if (IS_ERR(handle)) { 3882 retval = PTR_ERR(handle); 3883 goto release_bh; 3884 } 3885 } else { 3886 whiteout = ext4_whiteout_for_rename(idmap, &old, credits, &handle); 3887 if (IS_ERR(whiteout)) { 3888 retval = PTR_ERR(whiteout); 3889 goto release_bh; 3890 } 3891 } 3892 3893 old_file_type = old.de->file_type; 3894 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir)) 3895 ext4_handle_sync(handle); 3896 3897 if (S_ISDIR(old.inode->i_mode)) { 3898 if (new.inode) { 3899 retval = -ENOTEMPTY; 3900 if (!ext4_empty_dir(new.inode)) 3901 goto end_rename; 3902 } else { 3903 retval = -EMLINK; 3904 if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir)) 3905 goto end_rename; 3906 } 3907 retval = ext4_rename_dir_prepare(handle, &old, new.dir != old.dir); 3908 if (retval) 3909 goto end_rename; 3910 } 3911 /* 3912 * If we're renaming a file within an inline_data dir and adding or 3913 * setting the new dirent causes a conversion from inline_data to 3914 * extents/blockmap, we need to force the dirent delete code to 3915 * re-read the directory, or else we end up trying to delete a dirent 3916 * from what is now the extent tree root (or a block map). 3917 */ 3918 force_reread = (new.dir->i_ino == old.dir->i_ino && 3919 ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA)); 3920 3921 if (whiteout) { 3922 /* 3923 * Do this before adding a new entry, so the old entry is sure 3924 * to be still pointing to the valid old entry. 3925 */ 3926 retval = ext4_setent(handle, &old, whiteout->i_ino, 3927 EXT4_FT_CHRDEV); 3928 if (retval) 3929 goto end_rename; 3930 retval = ext4_mark_inode_dirty(handle, whiteout); 3931 if (unlikely(retval)) 3932 goto end_rename; 3933 3934 } 3935 if (!new.bh) { 3936 retval = ext4_add_entry(handle, new.dentry, old.inode); 3937 if (retval) 3938 goto end_rename; 3939 } else { 3940 retval = ext4_setent(handle, &new, 3941 old.inode->i_ino, old_file_type); 3942 if (retval) 3943 goto end_rename; 3944 } 3945 if (force_reread) 3946 force_reread = !ext4_test_inode_flag(new.dir, 3947 EXT4_INODE_INLINE_DATA); 3948 3949 /* 3950 * Like most other Unix systems, set the ctime for inodes on a 3951 * rename. 3952 */ 3953 inode_set_ctime_current(old.inode); 3954 retval = ext4_mark_inode_dirty(handle, old.inode); 3955 if (unlikely(retval)) 3956 goto end_rename; 3957 3958 if (!whiteout) { 3959 /* 3960 * ok, that's it 3961 */ 3962 ext4_rename_delete(handle, &old, force_reread); 3963 } 3964 3965 if (new.inode) { 3966 ext4_dec_count(new.inode); 3967 inode_set_ctime_current(new.inode); 3968 } 3969 inode_set_mtime_to_ts(old.dir, inode_set_ctime_current(old.dir)); 3970 ext4_update_dx_flag(old.dir); 3971 if (old.is_dir) { 3972 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); 3973 if (retval) 3974 goto end_rename; 3975 3976 ext4_dec_count(old.dir); 3977 if (new.inode) { 3978 /* checked ext4_empty_dir above, can't have another 3979 * parent, ext4_dec_count() won't work for many-linked 3980 * dirs */ 3981 clear_nlink(new.inode); 3982 } else { 3983 ext4_inc_count(new.dir); 3984 ext4_update_dx_flag(new.dir); 3985 retval = ext4_mark_inode_dirty(handle, new.dir); 3986 if (unlikely(retval)) 3987 goto end_rename; 3988 } 3989 } 3990 retval = ext4_mark_inode_dirty(handle, old.dir); 3991 if (unlikely(retval)) 3992 goto end_rename; 3993 3994 if (old.is_dir) { 3995 /* 3996 * We disable fast commits here that's because the 3997 * replay code is not yet capable of changing dot dot 3998 * dirents in directories. 3999 */ 4000 ext4_fc_mark_ineligible(old.inode->i_sb, 4001 EXT4_FC_REASON_RENAME_DIR, handle); 4002 } else { 4003 struct super_block *sb = old.inode->i_sb; 4004 4005 if (new.inode) 4006 ext4_fc_track_unlink(handle, new.dentry); 4007 if (test_opt2(sb, JOURNAL_FAST_COMMIT) && 4008 !(EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY) && 4009 !(ext4_test_mount_flag(sb, EXT4_MF_FC_INELIGIBLE))) { 4010 __ext4_fc_track_link(handle, old.inode, new.dentry); 4011 __ext4_fc_track_unlink(handle, old.inode, old.dentry); 4012 if (whiteout) 4013 __ext4_fc_track_create(handle, whiteout, 4014 old.dentry); 4015 } 4016 } 4017 4018 if (new.inode) { 4019 retval = ext4_mark_inode_dirty(handle, new.inode); 4020 if (unlikely(retval)) 4021 goto end_rename; 4022 if (!new.inode->i_nlink) 4023 ext4_orphan_add(handle, new.inode); 4024 } 4025 retval = 0; 4026 4027 end_rename: 4028 if (whiteout) { 4029 if (retval) { 4030 ext4_resetent(handle, &old, 4031 old.inode->i_ino, old_file_type); 4032 drop_nlink(whiteout); 4033 ext4_mark_inode_dirty(handle, whiteout); 4034 ext4_orphan_add(handle, whiteout); 4035 } 4036 unlock_new_inode(whiteout); 4037 ext4_journal_stop(handle); 4038 iput(whiteout); 4039 } else { 4040 ext4_journal_stop(handle); 4041 } 4042 release_bh: 4043 brelse(old.dir_bh); 4044 brelse(old.bh); 4045 brelse(new.bh); 4046 4047 return retval; 4048 } 4049 4050 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry, 4051 struct inode *new_dir, struct dentry *new_dentry) 4052 { 4053 handle_t *handle = NULL; 4054 struct ext4_renament old = { 4055 .dir = old_dir, 4056 .dentry = old_dentry, 4057 .inode = d_inode(old_dentry), 4058 }; 4059 struct ext4_renament new = { 4060 .dir = new_dir, 4061 .dentry = new_dentry, 4062 .inode = d_inode(new_dentry), 4063 }; 4064 u8 new_file_type; 4065 int retval; 4066 4067 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) && 4068 !projid_eq(EXT4_I(new_dir)->i_projid, 4069 EXT4_I(old_dentry->d_inode)->i_projid)) || 4070 (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) && 4071 !projid_eq(EXT4_I(old_dir)->i_projid, 4072 EXT4_I(new_dentry->d_inode)->i_projid))) 4073 return -EXDEV; 4074 4075 retval = dquot_initialize(old.dir); 4076 if (retval) 4077 return retval; 4078 retval = dquot_initialize(new.dir); 4079 if (retval) 4080 return retval; 4081 4082 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, 4083 &old.de, &old.inlined); 4084 if (IS_ERR(old.bh)) 4085 return PTR_ERR(old.bh); 4086 /* 4087 * Check for inode number is _not_ due to possible IO errors. 4088 * We might rmdir the source, keep it as pwd of some process 4089 * and merrily kill the link to whatever was created under the 4090 * same name. Goodbye sticky bit ;-< 4091 */ 4092 retval = -ENOENT; 4093 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino) 4094 goto end_rename; 4095 4096 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, 4097 &new.de, &new.inlined); 4098 if (IS_ERR(new.bh)) { 4099 retval = PTR_ERR(new.bh); 4100 new.bh = NULL; 4101 goto end_rename; 4102 } 4103 4104 /* RENAME_EXCHANGE case: old *and* new must both exist */ 4105 if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino) 4106 goto end_rename; 4107 4108 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, 4109 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + 4110 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2)); 4111 if (IS_ERR(handle)) { 4112 retval = PTR_ERR(handle); 4113 handle = NULL; 4114 goto end_rename; 4115 } 4116 4117 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir)) 4118 ext4_handle_sync(handle); 4119 4120 if (S_ISDIR(old.inode->i_mode)) { 4121 retval = ext4_rename_dir_prepare(handle, &old, new.dir != old.dir); 4122 if (retval) 4123 goto end_rename; 4124 } 4125 if (S_ISDIR(new.inode->i_mode)) { 4126 retval = ext4_rename_dir_prepare(handle, &new, new.dir != old.dir); 4127 if (retval) 4128 goto end_rename; 4129 } 4130 4131 /* 4132 * Other than the special case of overwriting a directory, parents' 4133 * nlink only needs to be modified if this is a cross directory rename. 4134 */ 4135 if (old.dir != new.dir && old.is_dir != new.is_dir) { 4136 old.dir_nlink_delta = old.is_dir ? -1 : 1; 4137 new.dir_nlink_delta = -old.dir_nlink_delta; 4138 retval = -EMLINK; 4139 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) || 4140 (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir))) 4141 goto end_rename; 4142 } 4143 4144 new_file_type = new.de->file_type; 4145 retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type); 4146 if (retval) 4147 goto end_rename; 4148 4149 retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type); 4150 if (retval) 4151 goto end_rename; 4152 4153 /* 4154 * Like most other Unix systems, set the ctime for inodes on a 4155 * rename. 4156 */ 4157 inode_set_ctime_current(old.inode); 4158 inode_set_ctime_current(new.inode); 4159 retval = ext4_mark_inode_dirty(handle, old.inode); 4160 if (unlikely(retval)) 4161 goto end_rename; 4162 retval = ext4_mark_inode_dirty(handle, new.inode); 4163 if (unlikely(retval)) 4164 goto end_rename; 4165 ext4_fc_mark_ineligible(new.inode->i_sb, 4166 EXT4_FC_REASON_CROSS_RENAME, handle); 4167 if (old.dir_bh) { 4168 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); 4169 if (retval) 4170 goto end_rename; 4171 } 4172 if (new.dir_bh) { 4173 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino); 4174 if (retval) 4175 goto end_rename; 4176 } 4177 ext4_update_dir_count(handle, &old); 4178 ext4_update_dir_count(handle, &new); 4179 retval = 0; 4180 4181 end_rename: 4182 brelse(old.dir_bh); 4183 brelse(new.dir_bh); 4184 brelse(old.bh); 4185 brelse(new.bh); 4186 if (handle) 4187 ext4_journal_stop(handle); 4188 return retval; 4189 } 4190 4191 static int ext4_rename2(struct mnt_idmap *idmap, 4192 struct inode *old_dir, struct dentry *old_dentry, 4193 struct inode *new_dir, struct dentry *new_dentry, 4194 unsigned int flags) 4195 { 4196 int err; 4197 4198 if (unlikely(ext4_forced_shutdown(old_dir->i_sb))) 4199 return -EIO; 4200 4201 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT)) 4202 return -EINVAL; 4203 4204 err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry, 4205 flags); 4206 if (err) 4207 return err; 4208 4209 if (flags & RENAME_EXCHANGE) { 4210 return ext4_cross_rename(old_dir, old_dentry, 4211 new_dir, new_dentry); 4212 } 4213 4214 return ext4_rename(idmap, old_dir, old_dentry, new_dir, new_dentry, flags); 4215 } 4216 4217 /* 4218 * directories can handle most operations... 4219 */ 4220 const struct inode_operations ext4_dir_inode_operations = { 4221 .create = ext4_create, 4222 .lookup = ext4_lookup, 4223 .link = ext4_link, 4224 .unlink = ext4_unlink, 4225 .symlink = ext4_symlink, 4226 .mkdir = ext4_mkdir, 4227 .rmdir = ext4_rmdir, 4228 .mknod = ext4_mknod, 4229 .tmpfile = ext4_tmpfile, 4230 .rename = ext4_rename2, 4231 .setattr = ext4_setattr, 4232 .getattr = ext4_getattr, 4233 .listxattr = ext4_listxattr, 4234 .get_inode_acl = ext4_get_acl, 4235 .set_acl = ext4_set_acl, 4236 .fiemap = ext4_fiemap, 4237 .fileattr_get = ext4_fileattr_get, 4238 .fileattr_set = ext4_fileattr_set, 4239 }; 4240 4241 const struct inode_operations ext4_special_inode_operations = { 4242 .setattr = ext4_setattr, 4243 .getattr = ext4_getattr, 4244 .listxattr = ext4_listxattr, 4245 .get_inode_acl = ext4_get_acl, 4246 .set_acl = ext4_set_acl, 4247 }; 4248