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 /* The first directory block must not be a hole. */ 155 if (!bh && (type == INDEX || type == DIRENT_HTREE || block == 0)) { 156 ext4_error_inode(inode, func, line, block, 157 "Directory hole found for htree %s block %u", 158 (type == INDEX) ? "index" : "leaf", block); 159 return ERR_PTR(-EFSCORRUPTED); 160 } 161 if (!bh) 162 return NULL; 163 dirent = (struct ext4_dir_entry *) bh->b_data; 164 /* Determine whether or not we have an index block */ 165 if (is_dx(inode)) { 166 if (block == 0) 167 is_dx_block = 1; 168 else if (ext4_rec_len_from_disk(dirent->rec_len, 169 inode->i_sb->s_blocksize) == 170 inode->i_sb->s_blocksize) 171 is_dx_block = 1; 172 } 173 if (!is_dx_block && type == INDEX) { 174 ext4_error_inode(inode, func, line, block, 175 "directory leaf block found instead of index block"); 176 brelse(bh); 177 return ERR_PTR(-EFSCORRUPTED); 178 } 179 if (!ext4_has_metadata_csum(inode->i_sb) || 180 buffer_verified(bh)) 181 return bh; 182 183 /* 184 * An empty leaf block can get mistaken for a index block; for 185 * this reason, we can only check the index checksum when the 186 * caller is sure it should be an index block. 187 */ 188 if (is_dx_block && type == INDEX) { 189 if (ext4_dx_csum_verify(inode, dirent) && 190 !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC)) 191 set_buffer_verified(bh); 192 else { 193 ext4_error_inode_err(inode, func, line, block, 194 EFSBADCRC, 195 "Directory index failed checksum"); 196 brelse(bh); 197 return ERR_PTR(-EFSBADCRC); 198 } 199 } 200 if (!is_dx_block) { 201 if (ext4_dirblock_csum_verify(inode, bh) && 202 !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC)) 203 set_buffer_verified(bh); 204 else { 205 ext4_error_inode_err(inode, func, line, block, 206 EFSBADCRC, 207 "Directory block failed checksum"); 208 brelse(bh); 209 return ERR_PTR(-EFSBADCRC); 210 } 211 } 212 return bh; 213 } 214 215 #ifdef DX_DEBUG 216 #define dxtrace(command) command 217 #else 218 #define dxtrace(command) 219 #endif 220 221 struct fake_dirent 222 { 223 __le32 inode; 224 __le16 rec_len; 225 u8 name_len; 226 u8 file_type; 227 }; 228 229 struct dx_countlimit 230 { 231 __le16 limit; 232 __le16 count; 233 }; 234 235 struct dx_entry 236 { 237 __le32 hash; 238 __le32 block; 239 }; 240 241 /* 242 * dx_root_info is laid out so that if it should somehow get overlaid by a 243 * dirent the two low bits of the hash version will be zero. Therefore, the 244 * hash version mod 4 should never be 0. Sincerely, the paranoia department. 245 */ 246 247 struct dx_root 248 { 249 struct fake_dirent dot; 250 char dot_name[4]; 251 struct fake_dirent dotdot; 252 char dotdot_name[4]; 253 struct dx_root_info 254 { 255 __le32 reserved_zero; 256 u8 hash_version; 257 u8 info_length; /* 8 */ 258 u8 indirect_levels; 259 u8 unused_flags; 260 } 261 info; 262 struct dx_entry entries[]; 263 }; 264 265 struct dx_node 266 { 267 struct fake_dirent fake; 268 struct dx_entry entries[]; 269 }; 270 271 272 struct dx_frame 273 { 274 struct buffer_head *bh; 275 struct dx_entry *entries; 276 struct dx_entry *at; 277 }; 278 279 struct dx_map_entry 280 { 281 u32 hash; 282 u16 offs; 283 u16 size; 284 }; 285 286 /* 287 * This goes at the end of each htree block. 288 */ 289 struct dx_tail { 290 u32 dt_reserved; 291 __le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */ 292 }; 293 294 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry); 295 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value); 296 static inline unsigned dx_get_hash(struct dx_entry *entry); 297 static void dx_set_hash(struct dx_entry *entry, unsigned value); 298 static unsigned dx_get_count(struct dx_entry *entries); 299 static unsigned dx_get_limit(struct dx_entry *entries); 300 static void dx_set_count(struct dx_entry *entries, unsigned value); 301 static void dx_set_limit(struct dx_entry *entries, unsigned value); 302 static unsigned dx_root_limit(struct inode *dir, unsigned infosize); 303 static unsigned dx_node_limit(struct inode *dir); 304 static struct dx_frame *dx_probe(struct ext4_filename *fname, 305 struct inode *dir, 306 struct dx_hash_info *hinfo, 307 struct dx_frame *frame); 308 static void dx_release(struct dx_frame *frames); 309 static int dx_make_map(struct inode *dir, struct buffer_head *bh, 310 struct dx_hash_info *hinfo, 311 struct dx_map_entry *map_tail); 312 static void dx_sort_map(struct dx_map_entry *map, unsigned count); 313 static struct ext4_dir_entry_2 *dx_move_dirents(struct inode *dir, char *from, 314 char *to, struct dx_map_entry *offsets, 315 int count, unsigned int blocksize); 316 static struct ext4_dir_entry_2 *dx_pack_dirents(struct inode *dir, char *base, 317 unsigned int blocksize); 318 static void dx_insert_block(struct dx_frame *frame, 319 u32 hash, ext4_lblk_t block); 320 static int ext4_htree_next_block(struct inode *dir, __u32 hash, 321 struct dx_frame *frame, 322 struct dx_frame *frames, 323 __u32 *start_hash); 324 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, 325 struct ext4_filename *fname, 326 struct ext4_dir_entry_2 **res_dir); 327 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname, 328 struct inode *dir, struct inode *inode); 329 330 /* checksumming functions */ 331 void ext4_initialize_dirent_tail(struct buffer_head *bh, 332 unsigned int blocksize) 333 { 334 struct ext4_dir_entry_tail *t = EXT4_DIRENT_TAIL(bh->b_data, blocksize); 335 336 memset(t, 0, sizeof(struct ext4_dir_entry_tail)); 337 t->det_rec_len = ext4_rec_len_to_disk( 338 sizeof(struct ext4_dir_entry_tail), blocksize); 339 t->det_reserved_ft = EXT4_FT_DIR_CSUM; 340 } 341 342 /* Walk through a dirent block to find a checksum "dirent" at the tail */ 343 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode, 344 struct buffer_head *bh) 345 { 346 struct ext4_dir_entry_tail *t; 347 int blocksize = EXT4_BLOCK_SIZE(inode->i_sb); 348 349 #ifdef PARANOID 350 struct ext4_dir_entry *d, *top; 351 352 d = (struct ext4_dir_entry *)bh->b_data; 353 top = (struct ext4_dir_entry *)(bh->b_data + 354 (blocksize - sizeof(struct ext4_dir_entry_tail))); 355 while (d < top && ext4_rec_len_from_disk(d->rec_len, blocksize)) 356 d = (struct ext4_dir_entry *)(((void *)d) + 357 ext4_rec_len_from_disk(d->rec_len, blocksize)); 358 359 if (d != top) 360 return NULL; 361 362 t = (struct ext4_dir_entry_tail *)d; 363 #else 364 t = EXT4_DIRENT_TAIL(bh->b_data, EXT4_BLOCK_SIZE(inode->i_sb)); 365 #endif 366 367 if (t->det_reserved_zero1 || 368 (ext4_rec_len_from_disk(t->det_rec_len, blocksize) != 369 sizeof(struct ext4_dir_entry_tail)) || 370 t->det_reserved_zero2 || 371 t->det_reserved_ft != EXT4_FT_DIR_CSUM) 372 return NULL; 373 374 return t; 375 } 376 377 static __le32 ext4_dirblock_csum(struct inode *inode, void *dirent, int size) 378 { 379 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 380 struct ext4_inode_info *ei = EXT4_I(inode); 381 __u32 csum; 382 383 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size); 384 return cpu_to_le32(csum); 385 } 386 387 #define warn_no_space_for_csum(inode) \ 388 __warn_no_space_for_csum((inode), __func__, __LINE__) 389 390 static void __warn_no_space_for_csum(struct inode *inode, const char *func, 391 unsigned int line) 392 { 393 __ext4_warning_inode(inode, func, line, 394 "No space for directory leaf checksum. Please run e2fsck -D."); 395 } 396 397 int ext4_dirblock_csum_verify(struct inode *inode, struct buffer_head *bh) 398 { 399 struct ext4_dir_entry_tail *t; 400 401 if (!ext4_has_metadata_csum(inode->i_sb)) 402 return 1; 403 404 t = get_dirent_tail(inode, bh); 405 if (!t) { 406 warn_no_space_for_csum(inode); 407 return 0; 408 } 409 410 if (t->det_checksum != ext4_dirblock_csum(inode, bh->b_data, 411 (char *)t - bh->b_data)) 412 return 0; 413 414 return 1; 415 } 416 417 static void ext4_dirblock_csum_set(struct inode *inode, 418 struct buffer_head *bh) 419 { 420 struct ext4_dir_entry_tail *t; 421 422 if (!ext4_has_metadata_csum(inode->i_sb)) 423 return; 424 425 t = get_dirent_tail(inode, bh); 426 if (!t) { 427 warn_no_space_for_csum(inode); 428 return; 429 } 430 431 t->det_checksum = ext4_dirblock_csum(inode, bh->b_data, 432 (char *)t - bh->b_data); 433 } 434 435 int ext4_handle_dirty_dirblock(handle_t *handle, 436 struct inode *inode, 437 struct buffer_head *bh) 438 { 439 ext4_dirblock_csum_set(inode, bh); 440 return ext4_handle_dirty_metadata(handle, inode, bh); 441 } 442 443 static struct dx_countlimit *get_dx_countlimit(struct inode *inode, 444 struct ext4_dir_entry *dirent, 445 int *offset) 446 { 447 struct ext4_dir_entry *dp; 448 struct dx_root_info *root; 449 int count_offset; 450 int blocksize = EXT4_BLOCK_SIZE(inode->i_sb); 451 unsigned int rlen = ext4_rec_len_from_disk(dirent->rec_len, blocksize); 452 453 if (rlen == blocksize) 454 count_offset = 8; 455 else if (rlen == 12) { 456 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12); 457 if (ext4_rec_len_from_disk(dp->rec_len, blocksize) != blocksize - 12) 458 return NULL; 459 root = (struct dx_root_info *)(((void *)dp + 12)); 460 if (root->reserved_zero || 461 root->info_length != sizeof(struct dx_root_info)) 462 return NULL; 463 count_offset = 32; 464 } else 465 return NULL; 466 467 if (offset) 468 *offset = count_offset; 469 return (struct dx_countlimit *)(((void *)dirent) + count_offset); 470 } 471 472 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent, 473 int count_offset, int count, struct dx_tail *t) 474 { 475 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 476 struct ext4_inode_info *ei = EXT4_I(inode); 477 __u32 csum; 478 int size; 479 __u32 dummy_csum = 0; 480 int offset = offsetof(struct dx_tail, dt_checksum); 481 482 size = count_offset + (count * sizeof(struct dx_entry)); 483 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size); 484 csum = ext4_chksum(sbi, csum, (__u8 *)t, offset); 485 csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum)); 486 487 return cpu_to_le32(csum); 488 } 489 490 static int ext4_dx_csum_verify(struct inode *inode, 491 struct ext4_dir_entry *dirent) 492 { 493 struct dx_countlimit *c; 494 struct dx_tail *t; 495 int count_offset, limit, count; 496 497 if (!ext4_has_metadata_csum(inode->i_sb)) 498 return 1; 499 500 c = get_dx_countlimit(inode, dirent, &count_offset); 501 if (!c) { 502 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D."); 503 return 0; 504 } 505 limit = le16_to_cpu(c->limit); 506 count = le16_to_cpu(c->count); 507 if (count_offset + (limit * sizeof(struct dx_entry)) > 508 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) { 509 warn_no_space_for_csum(inode); 510 return 0; 511 } 512 t = (struct dx_tail *)(((struct dx_entry *)c) + limit); 513 514 if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset, 515 count, t)) 516 return 0; 517 return 1; 518 } 519 520 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent) 521 { 522 struct dx_countlimit *c; 523 struct dx_tail *t; 524 int count_offset, limit, count; 525 526 if (!ext4_has_metadata_csum(inode->i_sb)) 527 return; 528 529 c = get_dx_countlimit(inode, dirent, &count_offset); 530 if (!c) { 531 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D."); 532 return; 533 } 534 limit = le16_to_cpu(c->limit); 535 count = le16_to_cpu(c->count); 536 if (count_offset + (limit * sizeof(struct dx_entry)) > 537 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) { 538 warn_no_space_for_csum(inode); 539 return; 540 } 541 t = (struct dx_tail *)(((struct dx_entry *)c) + limit); 542 543 t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t); 544 } 545 546 static inline int ext4_handle_dirty_dx_node(handle_t *handle, 547 struct inode *inode, 548 struct buffer_head *bh) 549 { 550 ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data); 551 return ext4_handle_dirty_metadata(handle, inode, bh); 552 } 553 554 /* 555 * p is at least 6 bytes before the end of page 556 */ 557 static inline struct ext4_dir_entry_2 * 558 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize) 559 { 560 return (struct ext4_dir_entry_2 *)((char *)p + 561 ext4_rec_len_from_disk(p->rec_len, blocksize)); 562 } 563 564 /* 565 * Future: use high four bits of block for coalesce-on-delete flags 566 * Mask them off for now. 567 */ 568 569 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry) 570 { 571 return le32_to_cpu(entry->block) & 0x0fffffff; 572 } 573 574 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value) 575 { 576 entry->block = cpu_to_le32(value); 577 } 578 579 static inline unsigned dx_get_hash(struct dx_entry *entry) 580 { 581 return le32_to_cpu(entry->hash); 582 } 583 584 static inline void dx_set_hash(struct dx_entry *entry, unsigned value) 585 { 586 entry->hash = cpu_to_le32(value); 587 } 588 589 static inline unsigned dx_get_count(struct dx_entry *entries) 590 { 591 return le16_to_cpu(((struct dx_countlimit *) entries)->count); 592 } 593 594 static inline unsigned dx_get_limit(struct dx_entry *entries) 595 { 596 return le16_to_cpu(((struct dx_countlimit *) entries)->limit); 597 } 598 599 static inline void dx_set_count(struct dx_entry *entries, unsigned value) 600 { 601 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value); 602 } 603 604 static inline void dx_set_limit(struct dx_entry *entries, unsigned value) 605 { 606 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value); 607 } 608 609 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize) 610 { 611 unsigned int entry_space = dir->i_sb->s_blocksize - 612 ext4_dir_rec_len(1, NULL) - 613 ext4_dir_rec_len(2, NULL) - infosize; 614 615 if (ext4_has_metadata_csum(dir->i_sb)) 616 entry_space -= sizeof(struct dx_tail); 617 return entry_space / sizeof(struct dx_entry); 618 } 619 620 static inline unsigned dx_node_limit(struct inode *dir) 621 { 622 unsigned int entry_space = dir->i_sb->s_blocksize - 623 ext4_dir_rec_len(0, dir); 624 625 if (ext4_has_metadata_csum(dir->i_sb)) 626 entry_space -= sizeof(struct dx_tail); 627 return entry_space / sizeof(struct dx_entry); 628 } 629 630 /* 631 * Debug 632 */ 633 #ifdef DX_DEBUG 634 static void dx_show_index(char * label, struct dx_entry *entries) 635 { 636 int i, n = dx_get_count (entries); 637 printk(KERN_DEBUG "%s index", label); 638 for (i = 0; i < n; i++) { 639 printk(KERN_CONT " %x->%lu", 640 i ? dx_get_hash(entries + i) : 0, 641 (unsigned long)dx_get_block(entries + i)); 642 } 643 printk(KERN_CONT "\n"); 644 } 645 646 struct stats 647 { 648 unsigned names; 649 unsigned space; 650 unsigned bcount; 651 }; 652 653 static struct stats dx_show_leaf(struct inode *dir, 654 struct dx_hash_info *hinfo, 655 struct ext4_dir_entry_2 *de, 656 int size, int show_names) 657 { 658 unsigned names = 0, space = 0; 659 char *base = (char *) de; 660 struct dx_hash_info h = *hinfo; 661 662 printk("names: "); 663 while ((char *) de < base + size) 664 { 665 if (de->inode) 666 { 667 if (show_names) 668 { 669 #ifdef CONFIG_FS_ENCRYPTION 670 int len; 671 char *name; 672 struct fscrypt_str fname_crypto_str = 673 FSTR_INIT(NULL, 0); 674 int res = 0; 675 676 name = de->name; 677 len = de->name_len; 678 if (!IS_ENCRYPTED(dir)) { 679 /* Directory is not encrypted */ 680 (void) ext4fs_dirhash(dir, de->name, 681 de->name_len, &h); 682 printk("%*.s:(U)%x.%u ", len, 683 name, h.hash, 684 (unsigned) ((char *) de 685 - base)); 686 } else { 687 struct fscrypt_str de_name = 688 FSTR_INIT(name, len); 689 690 /* Directory is encrypted */ 691 res = fscrypt_fname_alloc_buffer( 692 len, &fname_crypto_str); 693 if (res) 694 printk(KERN_WARNING "Error " 695 "allocating crypto " 696 "buffer--skipping " 697 "crypto\n"); 698 res = fscrypt_fname_disk_to_usr(dir, 699 0, 0, &de_name, 700 &fname_crypto_str); 701 if (res) { 702 printk(KERN_WARNING "Error " 703 "converting filename " 704 "from disk to usr" 705 "\n"); 706 name = "??"; 707 len = 2; 708 } else { 709 name = fname_crypto_str.name; 710 len = fname_crypto_str.len; 711 } 712 if (IS_CASEFOLDED(dir)) 713 h.hash = EXT4_DIRENT_HASH(de); 714 else 715 (void) ext4fs_dirhash(dir, 716 de->name, 717 de->name_len, &h); 718 printk("%*.s:(E)%x.%u ", len, name, 719 h.hash, (unsigned) ((char *) de 720 - base)); 721 fscrypt_fname_free_buffer( 722 &fname_crypto_str); 723 } 724 #else 725 int len = de->name_len; 726 char *name = de->name; 727 (void) ext4fs_dirhash(dir, de->name, 728 de->name_len, &h); 729 printk("%*.s:%x.%u ", len, name, h.hash, 730 (unsigned) ((char *) de - base)); 731 #endif 732 } 733 space += ext4_dir_rec_len(de->name_len, dir); 734 names++; 735 } 736 de = ext4_next_entry(de, size); 737 } 738 printk(KERN_CONT "(%i)\n", names); 739 return (struct stats) { names, space, 1 }; 740 } 741 742 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir, 743 struct dx_entry *entries, int levels) 744 { 745 unsigned blocksize = dir->i_sb->s_blocksize; 746 unsigned count = dx_get_count(entries), names = 0, space = 0, i; 747 unsigned bcount = 0; 748 struct buffer_head *bh; 749 printk("%i indexed blocks...\n", count); 750 for (i = 0; i < count; i++, entries++) 751 { 752 ext4_lblk_t block = dx_get_block(entries); 753 ext4_lblk_t hash = i ? dx_get_hash(entries): 0; 754 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash; 755 struct stats stats; 756 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range); 757 bh = ext4_bread(NULL,dir, block, 0); 758 if (!bh || IS_ERR(bh)) 759 continue; 760 stats = levels? 761 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1): 762 dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) 763 bh->b_data, blocksize, 0); 764 names += stats.names; 765 space += stats.space; 766 bcount += stats.bcount; 767 brelse(bh); 768 } 769 if (bcount) 770 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n", 771 levels ? "" : " ", names, space/bcount, 772 (space/bcount)*100/blocksize); 773 return (struct stats) { names, space, bcount}; 774 } 775 776 /* 777 * Linear search cross check 778 */ 779 static inline void htree_rep_invariant_check(struct dx_entry *at, 780 struct dx_entry *target, 781 u32 hash, unsigned int n) 782 { 783 while (n--) { 784 dxtrace(printk(KERN_CONT ",")); 785 if (dx_get_hash(++at) > hash) { 786 at--; 787 break; 788 } 789 } 790 ASSERT(at == target - 1); 791 } 792 #else /* DX_DEBUG */ 793 static inline void htree_rep_invariant_check(struct dx_entry *at, 794 struct dx_entry *target, 795 u32 hash, unsigned int n) 796 { 797 } 798 #endif /* DX_DEBUG */ 799 800 /* 801 * Probe for a directory leaf block to search. 802 * 803 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format 804 * error in the directory index, and the caller should fall back to 805 * searching the directory normally. The callers of dx_probe **MUST** 806 * check for this error code, and make sure it never gets reflected 807 * back to userspace. 808 */ 809 static struct dx_frame * 810 dx_probe(struct ext4_filename *fname, struct inode *dir, 811 struct dx_hash_info *hinfo, struct dx_frame *frame_in) 812 { 813 unsigned count, indirect, level, i; 814 struct dx_entry *at, *entries, *p, *q, *m; 815 struct dx_root *root; 816 struct dx_frame *frame = frame_in; 817 struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR); 818 u32 hash; 819 ext4_lblk_t block; 820 ext4_lblk_t blocks[EXT4_HTREE_LEVEL]; 821 822 memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0])); 823 frame->bh = ext4_read_dirblock(dir, 0, INDEX); 824 if (IS_ERR(frame->bh)) 825 return (struct dx_frame *) frame->bh; 826 827 root = (struct dx_root *) frame->bh->b_data; 828 if (root->info.hash_version != DX_HASH_TEA && 829 root->info.hash_version != DX_HASH_HALF_MD4 && 830 root->info.hash_version != DX_HASH_LEGACY && 831 root->info.hash_version != DX_HASH_SIPHASH) { 832 ext4_warning_inode(dir, "Unrecognised inode hash code %u", 833 root->info.hash_version); 834 goto fail; 835 } 836 if (ext4_hash_in_dirent(dir)) { 837 if (root->info.hash_version != DX_HASH_SIPHASH) { 838 ext4_warning_inode(dir, 839 "Hash in dirent, but hash is not SIPHASH"); 840 goto fail; 841 } 842 } else { 843 if (root->info.hash_version == DX_HASH_SIPHASH) { 844 ext4_warning_inode(dir, 845 "Hash code is SIPHASH, but hash not in dirent"); 846 goto fail; 847 } 848 } 849 if (fname) 850 hinfo = &fname->hinfo; 851 hinfo->hash_version = root->info.hash_version; 852 if (hinfo->hash_version <= DX_HASH_TEA) 853 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; 854 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed; 855 /* hash is already computed for encrypted casefolded directory */ 856 if (fname && fname_name(fname) && 857 !(IS_ENCRYPTED(dir) && IS_CASEFOLDED(dir))) { 858 int ret = ext4fs_dirhash(dir, fname_name(fname), 859 fname_len(fname), hinfo); 860 if (ret < 0) { 861 ret_err = ERR_PTR(ret); 862 goto fail; 863 } 864 } 865 hash = hinfo->hash; 866 867 if (root->info.unused_flags & 1) { 868 ext4_warning_inode(dir, "Unimplemented hash flags: %#06x", 869 root->info.unused_flags); 870 goto fail; 871 } 872 873 indirect = root->info.indirect_levels; 874 if (indirect >= ext4_dir_htree_level(dir->i_sb)) { 875 ext4_warning(dir->i_sb, 876 "Directory (ino: %lu) htree depth %#06x exceed" 877 "supported value", dir->i_ino, 878 ext4_dir_htree_level(dir->i_sb)); 879 if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) { 880 ext4_warning(dir->i_sb, "Enable large directory " 881 "feature to access it"); 882 } 883 goto fail; 884 } 885 886 entries = (struct dx_entry *)(((char *)&root->info) + 887 root->info.info_length); 888 889 if (dx_get_limit(entries) != dx_root_limit(dir, 890 root->info.info_length)) { 891 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u", 892 dx_get_limit(entries), 893 dx_root_limit(dir, root->info.info_length)); 894 goto fail; 895 } 896 897 dxtrace(printk("Look up %x", hash)); 898 level = 0; 899 blocks[0] = 0; 900 while (1) { 901 count = dx_get_count(entries); 902 if (!count || count > dx_get_limit(entries)) { 903 ext4_warning_inode(dir, 904 "dx entry: count %u beyond limit %u", 905 count, dx_get_limit(entries)); 906 goto fail; 907 } 908 909 p = entries + 1; 910 q = entries + count - 1; 911 while (p <= q) { 912 m = p + (q - p) / 2; 913 dxtrace(printk(KERN_CONT ".")); 914 if (dx_get_hash(m) > hash) 915 q = m - 1; 916 else 917 p = m + 1; 918 } 919 920 htree_rep_invariant_check(entries, p, hash, count - 1); 921 922 at = p - 1; 923 dxtrace(printk(KERN_CONT " %x->%u\n", 924 at == entries ? 0 : dx_get_hash(at), 925 dx_get_block(at))); 926 frame->entries = entries; 927 frame->at = at; 928 929 block = dx_get_block(at); 930 for (i = 0; i <= level; i++) { 931 if (blocks[i] == block) { 932 ext4_warning_inode(dir, 933 "dx entry: tree cycle block %u points back to block %u", 934 blocks[level], block); 935 goto fail; 936 } 937 } 938 if (++level > indirect) 939 return frame; 940 blocks[level] = block; 941 frame++; 942 frame->bh = ext4_read_dirblock(dir, block, INDEX); 943 if (IS_ERR(frame->bh)) { 944 ret_err = (struct dx_frame *) frame->bh; 945 frame->bh = NULL; 946 goto fail; 947 } 948 949 entries = ((struct dx_node *) frame->bh->b_data)->entries; 950 951 if (dx_get_limit(entries) != dx_node_limit(dir)) { 952 ext4_warning_inode(dir, 953 "dx entry: limit %u != node limit %u", 954 dx_get_limit(entries), dx_node_limit(dir)); 955 goto fail; 956 } 957 } 958 fail: 959 while (frame >= frame_in) { 960 brelse(frame->bh); 961 frame--; 962 } 963 964 if (ret_err == ERR_PTR(ERR_BAD_DX_DIR)) 965 ext4_warning_inode(dir, 966 "Corrupt directory, running e2fsck is recommended"); 967 return ret_err; 968 } 969 970 static void dx_release(struct dx_frame *frames) 971 { 972 struct dx_root_info *info; 973 int i; 974 unsigned int indirect_levels; 975 976 if (frames[0].bh == NULL) 977 return; 978 979 info = &((struct dx_root *)frames[0].bh->b_data)->info; 980 /* save local copy, "info" may be freed after brelse() */ 981 indirect_levels = info->indirect_levels; 982 for (i = 0; i <= indirect_levels; i++) { 983 if (frames[i].bh == NULL) 984 break; 985 brelse(frames[i].bh); 986 frames[i].bh = NULL; 987 } 988 } 989 990 /* 991 * This function increments the frame pointer to search the next leaf 992 * block, and reads in the necessary intervening nodes if the search 993 * should be necessary. Whether or not the search is necessary is 994 * controlled by the hash parameter. If the hash value is even, then 995 * the search is only continued if the next block starts with that 996 * hash value. This is used if we are searching for a specific file. 997 * 998 * If the hash value is HASH_NB_ALWAYS, then always go to the next block. 999 * 1000 * This function returns 1 if the caller should continue to search, 1001 * or 0 if it should not. If there is an error reading one of the 1002 * index blocks, it will a negative error code. 1003 * 1004 * If start_hash is non-null, it will be filled in with the starting 1005 * hash of the next page. 1006 */ 1007 static int ext4_htree_next_block(struct inode *dir, __u32 hash, 1008 struct dx_frame *frame, 1009 struct dx_frame *frames, 1010 __u32 *start_hash) 1011 { 1012 struct dx_frame *p; 1013 struct buffer_head *bh; 1014 int num_frames = 0; 1015 __u32 bhash; 1016 1017 p = frame; 1018 /* 1019 * Find the next leaf page by incrementing the frame pointer. 1020 * If we run out of entries in the interior node, loop around and 1021 * increment pointer in the parent node. When we break out of 1022 * this loop, num_frames indicates the number of interior 1023 * nodes need to be read. 1024 */ 1025 while (1) { 1026 if (++(p->at) < p->entries + dx_get_count(p->entries)) 1027 break; 1028 if (p == frames) 1029 return 0; 1030 num_frames++; 1031 p--; 1032 } 1033 1034 /* 1035 * If the hash is 1, then continue only if the next page has a 1036 * continuation hash of any value. This is used for readdir 1037 * handling. Otherwise, check to see if the hash matches the 1038 * desired continuation hash. If it doesn't, return since 1039 * there's no point to read in the successive index pages. 1040 */ 1041 bhash = dx_get_hash(p->at); 1042 if (start_hash) 1043 *start_hash = bhash; 1044 if ((hash & 1) == 0) { 1045 if ((bhash & ~1) != hash) 1046 return 0; 1047 } 1048 /* 1049 * If the hash is HASH_NB_ALWAYS, we always go to the next 1050 * block so no check is necessary 1051 */ 1052 while (num_frames--) { 1053 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX); 1054 if (IS_ERR(bh)) 1055 return PTR_ERR(bh); 1056 p++; 1057 brelse(p->bh); 1058 p->bh = bh; 1059 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries; 1060 } 1061 return 1; 1062 } 1063 1064 1065 /* 1066 * This function fills a red-black tree with information from a 1067 * directory block. It returns the number directory entries loaded 1068 * into the tree. If there is an error it is returned in err. 1069 */ 1070 static int htree_dirblock_to_tree(struct file *dir_file, 1071 struct inode *dir, ext4_lblk_t block, 1072 struct dx_hash_info *hinfo, 1073 __u32 start_hash, __u32 start_minor_hash) 1074 { 1075 struct buffer_head *bh; 1076 struct ext4_dir_entry_2 *de, *top; 1077 int err = 0, count = 0; 1078 struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str; 1079 int csum = ext4_has_metadata_csum(dir->i_sb); 1080 1081 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n", 1082 (unsigned long)block)); 1083 bh = ext4_read_dirblock(dir, block, DIRENT_HTREE); 1084 if (IS_ERR(bh)) 1085 return PTR_ERR(bh); 1086 1087 de = (struct ext4_dir_entry_2 *) bh->b_data; 1088 /* csum entries are not larger in the casefolded encrypted case */ 1089 top = (struct ext4_dir_entry_2 *) ((char *) de + 1090 dir->i_sb->s_blocksize - 1091 ext4_dir_rec_len(0, 1092 csum ? NULL : dir)); 1093 /* Check if the directory is encrypted */ 1094 if (IS_ENCRYPTED(dir)) { 1095 err = fscrypt_prepare_readdir(dir); 1096 if (err < 0) { 1097 brelse(bh); 1098 return err; 1099 } 1100 err = fscrypt_fname_alloc_buffer(EXT4_NAME_LEN, 1101 &fname_crypto_str); 1102 if (err < 0) { 1103 brelse(bh); 1104 return err; 1105 } 1106 } 1107 1108 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) { 1109 if (ext4_check_dir_entry(dir, NULL, de, bh, 1110 bh->b_data, bh->b_size, 1111 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb)) 1112 + ((char *)de - bh->b_data))) { 1113 /* silently ignore the rest of the block */ 1114 break; 1115 } 1116 if (ext4_hash_in_dirent(dir)) { 1117 if (de->name_len && de->inode) { 1118 hinfo->hash = EXT4_DIRENT_HASH(de); 1119 hinfo->minor_hash = EXT4_DIRENT_MINOR_HASH(de); 1120 } else { 1121 hinfo->hash = 0; 1122 hinfo->minor_hash = 0; 1123 } 1124 } else { 1125 err = ext4fs_dirhash(dir, de->name, 1126 de->name_len, hinfo); 1127 if (err < 0) { 1128 count = err; 1129 goto errout; 1130 } 1131 } 1132 if ((hinfo->hash < start_hash) || 1133 ((hinfo->hash == start_hash) && 1134 (hinfo->minor_hash < start_minor_hash))) 1135 continue; 1136 if (de->inode == 0) 1137 continue; 1138 if (!IS_ENCRYPTED(dir)) { 1139 tmp_str.name = de->name; 1140 tmp_str.len = de->name_len; 1141 err = ext4_htree_store_dirent(dir_file, 1142 hinfo->hash, hinfo->minor_hash, de, 1143 &tmp_str); 1144 } else { 1145 int save_len = fname_crypto_str.len; 1146 struct fscrypt_str de_name = FSTR_INIT(de->name, 1147 de->name_len); 1148 1149 /* Directory is encrypted */ 1150 err = fscrypt_fname_disk_to_usr(dir, hinfo->hash, 1151 hinfo->minor_hash, &de_name, 1152 &fname_crypto_str); 1153 if (err) { 1154 count = err; 1155 goto errout; 1156 } 1157 err = ext4_htree_store_dirent(dir_file, 1158 hinfo->hash, hinfo->minor_hash, de, 1159 &fname_crypto_str); 1160 fname_crypto_str.len = save_len; 1161 } 1162 if (err != 0) { 1163 count = err; 1164 goto errout; 1165 } 1166 count++; 1167 } 1168 errout: 1169 brelse(bh); 1170 fscrypt_fname_free_buffer(&fname_crypto_str); 1171 return count; 1172 } 1173 1174 1175 /* 1176 * This function fills a red-black tree with information from a 1177 * directory. We start scanning the directory in hash order, starting 1178 * at start_hash and start_minor_hash. 1179 * 1180 * This function returns the number of entries inserted into the tree, 1181 * or a negative error code. 1182 */ 1183 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash, 1184 __u32 start_minor_hash, __u32 *next_hash) 1185 { 1186 struct dx_hash_info hinfo; 1187 struct ext4_dir_entry_2 *de; 1188 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 1189 struct inode *dir; 1190 ext4_lblk_t block; 1191 int count = 0; 1192 int ret, err; 1193 __u32 hashval; 1194 struct fscrypt_str tmp_str; 1195 1196 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n", 1197 start_hash, start_minor_hash)); 1198 dir = file_inode(dir_file); 1199 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) { 1200 if (ext4_hash_in_dirent(dir)) 1201 hinfo.hash_version = DX_HASH_SIPHASH; 1202 else 1203 hinfo.hash_version = 1204 EXT4_SB(dir->i_sb)->s_def_hash_version; 1205 if (hinfo.hash_version <= DX_HASH_TEA) 1206 hinfo.hash_version += 1207 EXT4_SB(dir->i_sb)->s_hash_unsigned; 1208 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; 1209 if (ext4_has_inline_data(dir)) { 1210 int has_inline_data = 1; 1211 count = ext4_inlinedir_to_tree(dir_file, dir, 0, 1212 &hinfo, start_hash, 1213 start_minor_hash, 1214 &has_inline_data); 1215 if (has_inline_data) { 1216 *next_hash = ~0; 1217 return count; 1218 } 1219 } 1220 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo, 1221 start_hash, start_minor_hash); 1222 *next_hash = ~0; 1223 return count; 1224 } 1225 hinfo.hash = start_hash; 1226 hinfo.minor_hash = 0; 1227 frame = dx_probe(NULL, dir, &hinfo, frames); 1228 if (IS_ERR(frame)) 1229 return PTR_ERR(frame); 1230 1231 /* Add '.' and '..' from the htree header */ 1232 if (!start_hash && !start_minor_hash) { 1233 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; 1234 tmp_str.name = de->name; 1235 tmp_str.len = de->name_len; 1236 err = ext4_htree_store_dirent(dir_file, 0, 0, 1237 de, &tmp_str); 1238 if (err != 0) 1239 goto errout; 1240 count++; 1241 } 1242 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) { 1243 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; 1244 de = ext4_next_entry(de, dir->i_sb->s_blocksize); 1245 tmp_str.name = de->name; 1246 tmp_str.len = de->name_len; 1247 err = ext4_htree_store_dirent(dir_file, 2, 0, 1248 de, &tmp_str); 1249 if (err != 0) 1250 goto errout; 1251 count++; 1252 } 1253 1254 while (1) { 1255 if (fatal_signal_pending(current)) { 1256 err = -ERESTARTSYS; 1257 goto errout; 1258 } 1259 cond_resched(); 1260 block = dx_get_block(frame->at); 1261 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo, 1262 start_hash, start_minor_hash); 1263 if (ret < 0) { 1264 err = ret; 1265 goto errout; 1266 } 1267 count += ret; 1268 hashval = ~0; 1269 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS, 1270 frame, frames, &hashval); 1271 *next_hash = hashval; 1272 if (ret < 0) { 1273 err = ret; 1274 goto errout; 1275 } 1276 /* 1277 * Stop if: (a) there are no more entries, or 1278 * (b) we have inserted at least one entry and the 1279 * next hash value is not a continuation 1280 */ 1281 if ((ret == 0) || 1282 (count && ((hashval & 1) == 0))) 1283 break; 1284 } 1285 dx_release(frames); 1286 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, " 1287 "next hash: %x\n", count, *next_hash)); 1288 return count; 1289 errout: 1290 dx_release(frames); 1291 return (err); 1292 } 1293 1294 static inline int search_dirblock(struct buffer_head *bh, 1295 struct inode *dir, 1296 struct ext4_filename *fname, 1297 unsigned int offset, 1298 struct ext4_dir_entry_2 **res_dir) 1299 { 1300 return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir, 1301 fname, offset, res_dir); 1302 } 1303 1304 /* 1305 * Directory block splitting, compacting 1306 */ 1307 1308 /* 1309 * Create map of hash values, offsets, and sizes, stored at end of block. 1310 * Returns number of entries mapped. 1311 */ 1312 static int dx_make_map(struct inode *dir, struct buffer_head *bh, 1313 struct dx_hash_info *hinfo, 1314 struct dx_map_entry *map_tail) 1315 { 1316 int count = 0; 1317 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)bh->b_data; 1318 unsigned int buflen = bh->b_size; 1319 char *base = bh->b_data; 1320 struct dx_hash_info h = *hinfo; 1321 int blocksize = EXT4_BLOCK_SIZE(dir->i_sb); 1322 1323 if (ext4_has_metadata_csum(dir->i_sb)) 1324 buflen -= sizeof(struct ext4_dir_entry_tail); 1325 1326 while ((char *) de < base + buflen) { 1327 if (ext4_check_dir_entry(dir, NULL, de, bh, base, buflen, 1328 ((char *)de) - base)) 1329 return -EFSCORRUPTED; 1330 if (de->name_len && de->inode) { 1331 if (ext4_hash_in_dirent(dir)) 1332 h.hash = EXT4_DIRENT_HASH(de); 1333 else { 1334 int err = ext4fs_dirhash(dir, de->name, 1335 de->name_len, &h); 1336 if (err < 0) 1337 return err; 1338 } 1339 map_tail--; 1340 map_tail->hash = h.hash; 1341 map_tail->offs = ((char *) de - base)>>2; 1342 map_tail->size = ext4_rec_len_from_disk(de->rec_len, 1343 blocksize); 1344 count++; 1345 cond_resched(); 1346 } 1347 de = ext4_next_entry(de, blocksize); 1348 } 1349 return count; 1350 } 1351 1352 /* Sort map by hash value */ 1353 static void dx_sort_map (struct dx_map_entry *map, unsigned count) 1354 { 1355 struct dx_map_entry *p, *q, *top = map + count - 1; 1356 int more; 1357 /* Combsort until bubble sort doesn't suck */ 1358 while (count > 2) { 1359 count = count*10/13; 1360 if (count - 9 < 2) /* 9, 10 -> 11 */ 1361 count = 11; 1362 for (p = top, q = p - count; q >= map; p--, q--) 1363 if (p->hash < q->hash) 1364 swap(*p, *q); 1365 } 1366 /* Garden variety bubble sort */ 1367 do { 1368 more = 0; 1369 q = top; 1370 while (q-- > map) { 1371 if (q[1].hash >= q[0].hash) 1372 continue; 1373 swap(*(q+1), *q); 1374 more = 1; 1375 } 1376 } while(more); 1377 } 1378 1379 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block) 1380 { 1381 struct dx_entry *entries = frame->entries; 1382 struct dx_entry *old = frame->at, *new = old + 1; 1383 int count = dx_get_count(entries); 1384 1385 ASSERT(count < dx_get_limit(entries)); 1386 ASSERT(old < entries + count); 1387 memmove(new + 1, new, (char *)(entries + count) - (char *)(new)); 1388 dx_set_hash(new, hash); 1389 dx_set_block(new, block); 1390 dx_set_count(entries, count + 1); 1391 } 1392 1393 #if IS_ENABLED(CONFIG_UNICODE) 1394 int ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname, 1395 struct ext4_filename *name) 1396 { 1397 struct qstr *cf_name = &name->cf_name; 1398 unsigned char *buf; 1399 struct dx_hash_info *hinfo = &name->hinfo; 1400 int len; 1401 1402 if (!IS_CASEFOLDED(dir) || 1403 (IS_ENCRYPTED(dir) && !fscrypt_has_encryption_key(dir))) { 1404 cf_name->name = NULL; 1405 return 0; 1406 } 1407 1408 buf = kmalloc(EXT4_NAME_LEN, GFP_NOFS); 1409 if (!buf) 1410 return -ENOMEM; 1411 1412 len = utf8_casefold(dir->i_sb->s_encoding, iname, buf, EXT4_NAME_LEN); 1413 if (len <= 0) { 1414 kfree(buf); 1415 buf = NULL; 1416 } 1417 cf_name->name = buf; 1418 cf_name->len = (unsigned) len; 1419 1420 if (!IS_ENCRYPTED(dir)) 1421 return 0; 1422 1423 hinfo->hash_version = DX_HASH_SIPHASH; 1424 hinfo->seed = NULL; 1425 if (cf_name->name) 1426 return ext4fs_dirhash(dir, cf_name->name, cf_name->len, hinfo); 1427 else 1428 return ext4fs_dirhash(dir, iname->name, iname->len, hinfo); 1429 } 1430 #endif 1431 1432 /* 1433 * Test whether a directory entry matches the filename being searched for. 1434 * 1435 * Return: %true if the directory entry matches, otherwise %false. 1436 */ 1437 static bool ext4_match(struct inode *parent, 1438 const struct ext4_filename *fname, 1439 struct ext4_dir_entry_2 *de) 1440 { 1441 struct fscrypt_name f; 1442 1443 if (!de->inode) 1444 return false; 1445 1446 f.usr_fname = fname->usr_fname; 1447 f.disk_name = fname->disk_name; 1448 #ifdef CONFIG_FS_ENCRYPTION 1449 f.crypto_buf = fname->crypto_buf; 1450 #endif 1451 1452 #if IS_ENABLED(CONFIG_UNICODE) 1453 if (IS_CASEFOLDED(parent) && 1454 (!IS_ENCRYPTED(parent) || fscrypt_has_encryption_key(parent))) { 1455 /* 1456 * Just checking IS_ENCRYPTED(parent) below is not 1457 * sufficient to decide whether one can use the hash for 1458 * skipping the string comparison, because the key might 1459 * have been added right after 1460 * ext4_fname_setup_ci_filename(). In this case, a hash 1461 * mismatch will be a false negative. Therefore, make 1462 * sure cf_name was properly initialized before 1463 * considering the calculated hash. 1464 */ 1465 if (IS_ENCRYPTED(parent) && fname->cf_name.name && 1466 (fname->hinfo.hash != EXT4_DIRENT_HASH(de) || 1467 fname->hinfo.minor_hash != EXT4_DIRENT_MINOR_HASH(de))) 1468 return false; 1469 /* 1470 * Treat comparison errors as not a match. The 1471 * only case where it happens is on a disk 1472 * corruption or ENOMEM. 1473 */ 1474 1475 return generic_ci_match(parent, fname->usr_fname, 1476 &fname->cf_name, de->name, 1477 de->name_len) > 0; 1478 } 1479 #endif 1480 1481 return fscrypt_match_name(&f, de->name, de->name_len); 1482 } 1483 1484 /* 1485 * Returns 0 if not found, -EFSCORRUPTED on failure, and 1 on success 1486 */ 1487 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size, 1488 struct inode *dir, struct ext4_filename *fname, 1489 unsigned int offset, struct ext4_dir_entry_2 **res_dir) 1490 { 1491 struct ext4_dir_entry_2 * de; 1492 char * dlimit; 1493 int de_len; 1494 1495 de = (struct ext4_dir_entry_2 *)search_buf; 1496 dlimit = search_buf + buf_size; 1497 while ((char *) de < dlimit - EXT4_BASE_DIR_LEN) { 1498 /* this code is executed quadratically often */ 1499 /* do minimal checking `by hand' */ 1500 if (de->name + de->name_len <= dlimit && 1501 ext4_match(dir, fname, de)) { 1502 /* found a match - just to be sure, do 1503 * a full check */ 1504 if (ext4_check_dir_entry(dir, NULL, de, bh, search_buf, 1505 buf_size, offset)) 1506 return -EFSCORRUPTED; 1507 *res_dir = de; 1508 return 1; 1509 } 1510 /* prevent looping on a bad block */ 1511 de_len = ext4_rec_len_from_disk(de->rec_len, 1512 dir->i_sb->s_blocksize); 1513 if (de_len <= 0) 1514 return -EFSCORRUPTED; 1515 offset += de_len; 1516 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len); 1517 } 1518 return 0; 1519 } 1520 1521 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block, 1522 struct ext4_dir_entry *de) 1523 { 1524 struct super_block *sb = dir->i_sb; 1525 1526 if (!is_dx(dir)) 1527 return 0; 1528 if (block == 0) 1529 return 1; 1530 if (de->inode == 0 && 1531 ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) == 1532 sb->s_blocksize) 1533 return 1; 1534 return 0; 1535 } 1536 1537 /* 1538 * __ext4_find_entry() 1539 * 1540 * finds an entry in the specified directory with the wanted name. It 1541 * returns the cache buffer in which the entry was found, and the entry 1542 * itself (as a parameter - res_dir). It does NOT read the inode of the 1543 * entry - you'll have to do that yourself if you want to. 1544 * 1545 * The returned buffer_head has ->b_count elevated. The caller is expected 1546 * to brelse() it when appropriate. 1547 */ 1548 static struct buffer_head *__ext4_find_entry(struct inode *dir, 1549 struct ext4_filename *fname, 1550 struct ext4_dir_entry_2 **res_dir, 1551 int *inlined) 1552 { 1553 struct super_block *sb; 1554 struct buffer_head *bh_use[NAMEI_RA_SIZE]; 1555 struct buffer_head *bh, *ret = NULL; 1556 ext4_lblk_t start, block; 1557 const u8 *name = fname->usr_fname->name; 1558 size_t ra_max = 0; /* Number of bh's in the readahead 1559 buffer, bh_use[] */ 1560 size_t ra_ptr = 0; /* Current index into readahead 1561 buffer */ 1562 ext4_lblk_t nblocks; 1563 int i, namelen, retval; 1564 1565 *res_dir = NULL; 1566 sb = dir->i_sb; 1567 namelen = fname->usr_fname->len; 1568 if (namelen > EXT4_NAME_LEN) 1569 return NULL; 1570 1571 if (ext4_has_inline_data(dir)) { 1572 int has_inline_data = 1; 1573 ret = ext4_find_inline_entry(dir, fname, res_dir, 1574 &has_inline_data); 1575 if (inlined) 1576 *inlined = has_inline_data; 1577 if (has_inline_data || IS_ERR(ret)) 1578 goto cleanup_and_exit; 1579 } 1580 1581 if ((namelen <= 2) && (name[0] == '.') && 1582 (name[1] == '.' || name[1] == '\0')) { 1583 /* 1584 * "." or ".." will only be in the first block 1585 * NFS may look up ".."; "." should be handled by the VFS 1586 */ 1587 block = start = 0; 1588 nblocks = 1; 1589 goto restart; 1590 } 1591 if (is_dx(dir)) { 1592 ret = ext4_dx_find_entry(dir, fname, res_dir); 1593 /* 1594 * On success, or if the error was file not found, 1595 * return. Otherwise, fall back to doing a search the 1596 * old fashioned way. 1597 */ 1598 if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR) 1599 goto cleanup_and_exit; 1600 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, " 1601 "falling back\n")); 1602 ret = NULL; 1603 } 1604 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); 1605 if (!nblocks) { 1606 ret = NULL; 1607 goto cleanup_and_exit; 1608 } 1609 start = EXT4_I(dir)->i_dir_start_lookup; 1610 if (start >= nblocks) 1611 start = 0; 1612 block = start; 1613 restart: 1614 do { 1615 /* 1616 * We deal with the read-ahead logic here. 1617 */ 1618 cond_resched(); 1619 if (ra_ptr >= ra_max) { 1620 /* Refill the readahead buffer */ 1621 ra_ptr = 0; 1622 if (block < start) 1623 ra_max = start - block; 1624 else 1625 ra_max = nblocks - block; 1626 ra_max = min(ra_max, ARRAY_SIZE(bh_use)); 1627 retval = ext4_bread_batch(dir, block, ra_max, 1628 false /* wait */, bh_use); 1629 if (retval) { 1630 ret = ERR_PTR(retval); 1631 ra_max = 0; 1632 goto cleanup_and_exit; 1633 } 1634 } 1635 if ((bh = bh_use[ra_ptr++]) == NULL) 1636 goto next; 1637 wait_on_buffer(bh); 1638 if (!buffer_uptodate(bh)) { 1639 EXT4_ERROR_INODE_ERR(dir, EIO, 1640 "reading directory lblock %lu", 1641 (unsigned long) block); 1642 brelse(bh); 1643 ret = ERR_PTR(-EIO); 1644 goto cleanup_and_exit; 1645 } 1646 if (!buffer_verified(bh) && 1647 !is_dx_internal_node(dir, block, 1648 (struct ext4_dir_entry *)bh->b_data) && 1649 !ext4_dirblock_csum_verify(dir, bh)) { 1650 EXT4_ERROR_INODE_ERR(dir, EFSBADCRC, 1651 "checksumming directory " 1652 "block %lu", (unsigned long)block); 1653 brelse(bh); 1654 ret = ERR_PTR(-EFSBADCRC); 1655 goto cleanup_and_exit; 1656 } 1657 set_buffer_verified(bh); 1658 i = search_dirblock(bh, dir, fname, 1659 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir); 1660 if (i == 1) { 1661 EXT4_I(dir)->i_dir_start_lookup = block; 1662 ret = bh; 1663 goto cleanup_and_exit; 1664 } else { 1665 brelse(bh); 1666 if (i < 0) { 1667 ret = ERR_PTR(i); 1668 goto cleanup_and_exit; 1669 } 1670 } 1671 next: 1672 if (++block >= nblocks) 1673 block = 0; 1674 } while (block != start); 1675 1676 /* 1677 * If the directory has grown while we were searching, then 1678 * search the last part of the directory before giving up. 1679 */ 1680 block = nblocks; 1681 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); 1682 if (block < nblocks) { 1683 start = 0; 1684 goto restart; 1685 } 1686 1687 cleanup_and_exit: 1688 /* Clean up the read-ahead blocks */ 1689 for (; ra_ptr < ra_max; ra_ptr++) 1690 brelse(bh_use[ra_ptr]); 1691 return ret; 1692 } 1693 1694 static struct buffer_head *ext4_find_entry(struct inode *dir, 1695 const struct qstr *d_name, 1696 struct ext4_dir_entry_2 **res_dir, 1697 int *inlined) 1698 { 1699 int err; 1700 struct ext4_filename fname; 1701 struct buffer_head *bh; 1702 1703 err = ext4_fname_setup_filename(dir, d_name, 1, &fname); 1704 if (err == -ENOENT) 1705 return NULL; 1706 if (err) 1707 return ERR_PTR(err); 1708 1709 bh = __ext4_find_entry(dir, &fname, res_dir, inlined); 1710 1711 ext4_fname_free_filename(&fname); 1712 return bh; 1713 } 1714 1715 static struct buffer_head *ext4_lookup_entry(struct inode *dir, 1716 struct dentry *dentry, 1717 struct ext4_dir_entry_2 **res_dir) 1718 { 1719 int err; 1720 struct ext4_filename fname; 1721 struct buffer_head *bh; 1722 1723 err = ext4_fname_prepare_lookup(dir, dentry, &fname); 1724 if (err == -ENOENT) 1725 return NULL; 1726 if (err) 1727 return ERR_PTR(err); 1728 1729 bh = __ext4_find_entry(dir, &fname, res_dir, NULL); 1730 1731 ext4_fname_free_filename(&fname); 1732 return bh; 1733 } 1734 1735 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, 1736 struct ext4_filename *fname, 1737 struct ext4_dir_entry_2 **res_dir) 1738 { 1739 struct super_block * sb = dir->i_sb; 1740 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 1741 struct buffer_head *bh; 1742 ext4_lblk_t block; 1743 int retval; 1744 1745 #ifdef CONFIG_FS_ENCRYPTION 1746 *res_dir = NULL; 1747 #endif 1748 frame = dx_probe(fname, dir, NULL, frames); 1749 if (IS_ERR(frame)) 1750 return ERR_CAST(frame); 1751 do { 1752 block = dx_get_block(frame->at); 1753 bh = ext4_read_dirblock(dir, block, DIRENT_HTREE); 1754 if (IS_ERR(bh)) 1755 goto errout; 1756 1757 retval = search_dirblock(bh, dir, fname, 1758 block << EXT4_BLOCK_SIZE_BITS(sb), 1759 res_dir); 1760 if (retval == 1) 1761 goto success; 1762 brelse(bh); 1763 if (retval < 0) { 1764 bh = ERR_PTR(ERR_BAD_DX_DIR); 1765 goto errout; 1766 } 1767 1768 /* Check to see if we should continue to search */ 1769 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame, 1770 frames, NULL); 1771 if (retval < 0) { 1772 ext4_warning_inode(dir, 1773 "error %d reading directory index block", 1774 retval); 1775 bh = ERR_PTR(retval); 1776 goto errout; 1777 } 1778 } while (retval == 1); 1779 1780 bh = NULL; 1781 errout: 1782 dxtrace(printk(KERN_DEBUG "%s not found\n", fname->usr_fname->name)); 1783 success: 1784 dx_release(frames); 1785 return bh; 1786 } 1787 1788 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 1789 { 1790 struct inode *inode; 1791 struct ext4_dir_entry_2 *de; 1792 struct buffer_head *bh; 1793 1794 if (dentry->d_name.len > EXT4_NAME_LEN) 1795 return ERR_PTR(-ENAMETOOLONG); 1796 1797 bh = ext4_lookup_entry(dir, dentry, &de); 1798 if (IS_ERR(bh)) 1799 return ERR_CAST(bh); 1800 inode = NULL; 1801 if (bh) { 1802 __u32 ino = le32_to_cpu(de->inode); 1803 brelse(bh); 1804 if (!ext4_valid_inum(dir->i_sb, ino)) { 1805 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino); 1806 return ERR_PTR(-EFSCORRUPTED); 1807 } 1808 if (unlikely(ino == dir->i_ino)) { 1809 EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir", 1810 dentry); 1811 return ERR_PTR(-EFSCORRUPTED); 1812 } 1813 inode = ext4_iget(dir->i_sb, ino, EXT4_IGET_NORMAL); 1814 if (inode == ERR_PTR(-ESTALE)) { 1815 EXT4_ERROR_INODE(dir, 1816 "deleted inode referenced: %u", 1817 ino); 1818 return ERR_PTR(-EFSCORRUPTED); 1819 } 1820 if (!IS_ERR(inode) && IS_ENCRYPTED(dir) && 1821 (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) && 1822 !fscrypt_has_permitted_context(dir, inode)) { 1823 ext4_warning(inode->i_sb, 1824 "Inconsistent encryption contexts: %lu/%lu", 1825 dir->i_ino, inode->i_ino); 1826 iput(inode); 1827 return ERR_PTR(-EPERM); 1828 } 1829 } 1830 1831 if (IS_ENABLED(CONFIG_UNICODE) && !inode && IS_CASEFOLDED(dir)) { 1832 /* Eventually we want to call d_add_ci(dentry, NULL) 1833 * for negative dentries in the encoding case as 1834 * well. For now, prevent the negative dentry 1835 * from being cached. 1836 */ 1837 return NULL; 1838 } 1839 1840 return d_splice_alias(inode, dentry); 1841 } 1842 1843 1844 struct dentry *ext4_get_parent(struct dentry *child) 1845 { 1846 __u32 ino; 1847 struct ext4_dir_entry_2 * de; 1848 struct buffer_head *bh; 1849 1850 bh = ext4_find_entry(d_inode(child), &dotdot_name, &de, NULL); 1851 if (IS_ERR(bh)) 1852 return ERR_CAST(bh); 1853 if (!bh) 1854 return ERR_PTR(-ENOENT); 1855 ino = le32_to_cpu(de->inode); 1856 brelse(bh); 1857 1858 if (!ext4_valid_inum(child->d_sb, ino)) { 1859 EXT4_ERROR_INODE(d_inode(child), 1860 "bad parent inode number: %u", ino); 1861 return ERR_PTR(-EFSCORRUPTED); 1862 } 1863 1864 return d_obtain_alias(ext4_iget(child->d_sb, ino, EXT4_IGET_NORMAL)); 1865 } 1866 1867 /* 1868 * Move count entries from end of map between two memory locations. 1869 * Returns pointer to last entry moved. 1870 */ 1871 static struct ext4_dir_entry_2 * 1872 dx_move_dirents(struct inode *dir, char *from, char *to, 1873 struct dx_map_entry *map, int count, 1874 unsigned blocksize) 1875 { 1876 unsigned rec_len = 0; 1877 1878 while (count--) { 1879 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) 1880 (from + (map->offs<<2)); 1881 rec_len = ext4_dir_rec_len(de->name_len, dir); 1882 1883 memcpy (to, de, rec_len); 1884 ((struct ext4_dir_entry_2 *) to)->rec_len = 1885 ext4_rec_len_to_disk(rec_len, blocksize); 1886 1887 /* wipe dir_entry excluding the rec_len field */ 1888 de->inode = 0; 1889 memset(&de->name_len, 0, ext4_rec_len_from_disk(de->rec_len, 1890 blocksize) - 1891 offsetof(struct ext4_dir_entry_2, 1892 name_len)); 1893 1894 map++; 1895 to += rec_len; 1896 } 1897 return (struct ext4_dir_entry_2 *) (to - rec_len); 1898 } 1899 1900 /* 1901 * Compact each dir entry in the range to the minimal rec_len. 1902 * Returns pointer to last entry in range. 1903 */ 1904 static struct ext4_dir_entry_2 *dx_pack_dirents(struct inode *dir, char *base, 1905 unsigned int blocksize) 1906 { 1907 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base; 1908 unsigned rec_len = 0; 1909 1910 prev = to = de; 1911 while ((char*)de < base + blocksize) { 1912 next = ext4_next_entry(de, blocksize); 1913 if (de->inode && de->name_len) { 1914 rec_len = ext4_dir_rec_len(de->name_len, dir); 1915 if (de > to) 1916 memmove(to, de, rec_len); 1917 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize); 1918 prev = to; 1919 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len); 1920 } 1921 de = next; 1922 } 1923 return prev; 1924 } 1925 1926 /* 1927 * Split a full leaf block to make room for a new dir entry. 1928 * Allocate a new block, and move entries so that they are approx. equally full. 1929 * Returns pointer to de in block into which the new entry will be inserted. 1930 */ 1931 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir, 1932 struct buffer_head **bh,struct dx_frame *frame, 1933 struct dx_hash_info *hinfo) 1934 { 1935 unsigned blocksize = dir->i_sb->s_blocksize; 1936 unsigned continued; 1937 int count; 1938 struct buffer_head *bh2; 1939 ext4_lblk_t newblock; 1940 u32 hash2; 1941 struct dx_map_entry *map; 1942 char *data1 = (*bh)->b_data, *data2; 1943 unsigned split, move, size; 1944 struct ext4_dir_entry_2 *de = NULL, *de2; 1945 int csum_size = 0; 1946 int err = 0, i; 1947 1948 if (ext4_has_metadata_csum(dir->i_sb)) 1949 csum_size = sizeof(struct ext4_dir_entry_tail); 1950 1951 bh2 = ext4_append(handle, dir, &newblock); 1952 if (IS_ERR(bh2)) { 1953 brelse(*bh); 1954 *bh = NULL; 1955 return ERR_CAST(bh2); 1956 } 1957 1958 BUFFER_TRACE(*bh, "get_write_access"); 1959 err = ext4_journal_get_write_access(handle, dir->i_sb, *bh, 1960 EXT4_JTR_NONE); 1961 if (err) 1962 goto journal_error; 1963 1964 BUFFER_TRACE(frame->bh, "get_write_access"); 1965 err = ext4_journal_get_write_access(handle, dir->i_sb, frame->bh, 1966 EXT4_JTR_NONE); 1967 if (err) 1968 goto journal_error; 1969 1970 data2 = bh2->b_data; 1971 1972 /* create map in the end of data2 block */ 1973 map = (struct dx_map_entry *) (data2 + blocksize); 1974 count = dx_make_map(dir, *bh, hinfo, map); 1975 if (count < 0) { 1976 err = count; 1977 goto journal_error; 1978 } 1979 map -= count; 1980 dx_sort_map(map, count); 1981 /* Ensure that neither split block is over half full */ 1982 size = 0; 1983 move = 0; 1984 for (i = count-1; i >= 0; i--) { 1985 /* is more than half of this entry in 2nd half of the block? */ 1986 if (size + map[i].size/2 > blocksize/2) 1987 break; 1988 size += map[i].size; 1989 move++; 1990 } 1991 /* 1992 * map index at which we will split 1993 * 1994 * If the sum of active entries didn't exceed half the block size, just 1995 * split it in half by count; each resulting block will have at least 1996 * half the space free. 1997 */ 1998 if (i > 0) 1999 split = count - move; 2000 else 2001 split = count/2; 2002 2003 if (WARN_ON_ONCE(split == 0)) { 2004 /* Should never happen, but avoid out-of-bounds access below */ 2005 ext4_error_inode_block(dir, (*bh)->b_blocknr, 0, 2006 "bad indexed directory? hash=%08x:%08x count=%d move=%u", 2007 hinfo->hash, hinfo->minor_hash, count, move); 2008 err = -EFSCORRUPTED; 2009 goto out; 2010 } 2011 2012 hash2 = map[split].hash; 2013 continued = hash2 == map[split - 1].hash; 2014 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n", 2015 (unsigned long)dx_get_block(frame->at), 2016 hash2, split, count-split)); 2017 2018 /* Fancy dance to stay within two buffers */ 2019 de2 = dx_move_dirents(dir, data1, data2, map + split, count - split, 2020 blocksize); 2021 de = dx_pack_dirents(dir, data1, blocksize); 2022 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) - 2023 (char *) de, 2024 blocksize); 2025 de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) - 2026 (char *) de2, 2027 blocksize); 2028 if (csum_size) { 2029 ext4_initialize_dirent_tail(*bh, blocksize); 2030 ext4_initialize_dirent_tail(bh2, blocksize); 2031 } 2032 2033 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1, 2034 blocksize, 1)); 2035 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2, 2036 blocksize, 1)); 2037 2038 /* Which block gets the new entry? */ 2039 if (hinfo->hash >= hash2) { 2040 swap(*bh, bh2); 2041 de = de2; 2042 } 2043 dx_insert_block(frame, hash2 + continued, newblock); 2044 err = ext4_handle_dirty_dirblock(handle, dir, bh2); 2045 if (err) 2046 goto journal_error; 2047 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 2048 if (err) 2049 goto journal_error; 2050 brelse(bh2); 2051 dxtrace(dx_show_index("frame", frame->entries)); 2052 return de; 2053 2054 journal_error: 2055 ext4_std_error(dir->i_sb, err); 2056 out: 2057 brelse(*bh); 2058 brelse(bh2); 2059 *bh = NULL; 2060 return ERR_PTR(err); 2061 } 2062 2063 int ext4_find_dest_de(struct inode *dir, struct inode *inode, 2064 struct buffer_head *bh, 2065 void *buf, int buf_size, 2066 struct ext4_filename *fname, 2067 struct ext4_dir_entry_2 **dest_de) 2068 { 2069 struct ext4_dir_entry_2 *de; 2070 unsigned short reclen = ext4_dir_rec_len(fname_len(fname), dir); 2071 int nlen, rlen; 2072 unsigned int offset = 0; 2073 char *top; 2074 2075 de = buf; 2076 top = buf + buf_size - reclen; 2077 while ((char *) de <= top) { 2078 if (ext4_check_dir_entry(dir, NULL, de, bh, 2079 buf, buf_size, offset)) 2080 return -EFSCORRUPTED; 2081 if (ext4_match(dir, fname, de)) 2082 return -EEXIST; 2083 nlen = ext4_dir_rec_len(de->name_len, dir); 2084 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 2085 if ((de->inode ? rlen - nlen : rlen) >= reclen) 2086 break; 2087 de = (struct ext4_dir_entry_2 *)((char *)de + rlen); 2088 offset += rlen; 2089 } 2090 if ((char *) de > top) 2091 return -ENOSPC; 2092 2093 *dest_de = de; 2094 return 0; 2095 } 2096 2097 void ext4_insert_dentry(struct inode *dir, 2098 struct inode *inode, 2099 struct ext4_dir_entry_2 *de, 2100 int buf_size, 2101 struct ext4_filename *fname) 2102 { 2103 2104 int nlen, rlen; 2105 2106 nlen = ext4_dir_rec_len(de->name_len, dir); 2107 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 2108 if (de->inode) { 2109 struct ext4_dir_entry_2 *de1 = 2110 (struct ext4_dir_entry_2 *)((char *)de + nlen); 2111 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size); 2112 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size); 2113 de = de1; 2114 } 2115 de->file_type = EXT4_FT_UNKNOWN; 2116 de->inode = cpu_to_le32(inode->i_ino); 2117 ext4_set_de_type(inode->i_sb, de, inode->i_mode); 2118 de->name_len = fname_len(fname); 2119 memcpy(de->name, fname_name(fname), fname_len(fname)); 2120 if (ext4_hash_in_dirent(dir)) { 2121 struct dx_hash_info *hinfo = &fname->hinfo; 2122 2123 EXT4_DIRENT_HASHES(de)->hash = cpu_to_le32(hinfo->hash); 2124 EXT4_DIRENT_HASHES(de)->minor_hash = 2125 cpu_to_le32(hinfo->minor_hash); 2126 } 2127 } 2128 2129 /* 2130 * Add a new entry into a directory (leaf) block. If de is non-NULL, 2131 * it points to a directory entry which is guaranteed to be large 2132 * enough for new directory entry. If de is NULL, then 2133 * add_dirent_to_buf will attempt search the directory block for 2134 * space. It will return -ENOSPC if no space is available, and -EIO 2135 * and -EEXIST if directory entry already exists. 2136 */ 2137 static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname, 2138 struct inode *dir, 2139 struct inode *inode, struct ext4_dir_entry_2 *de, 2140 struct buffer_head *bh) 2141 { 2142 unsigned int blocksize = dir->i_sb->s_blocksize; 2143 int csum_size = 0; 2144 int err, err2; 2145 2146 if (ext4_has_metadata_csum(inode->i_sb)) 2147 csum_size = sizeof(struct ext4_dir_entry_tail); 2148 2149 if (!de) { 2150 err = ext4_find_dest_de(dir, inode, bh, bh->b_data, 2151 blocksize - csum_size, fname, &de); 2152 if (err) 2153 return err; 2154 } 2155 BUFFER_TRACE(bh, "get_write_access"); 2156 err = ext4_journal_get_write_access(handle, dir->i_sb, bh, 2157 EXT4_JTR_NONE); 2158 if (err) { 2159 ext4_std_error(dir->i_sb, err); 2160 return err; 2161 } 2162 2163 /* By now the buffer is marked for journaling */ 2164 ext4_insert_dentry(dir, inode, de, blocksize, fname); 2165 2166 /* 2167 * XXX shouldn't update any times until successful 2168 * completion of syscall, but too many callers depend 2169 * on this. 2170 * 2171 * XXX similarly, too many callers depend on 2172 * ext4_new_inode() setting the times, but error 2173 * recovery deletes the inode, so the worst that can 2174 * happen is that the times are slightly out of date 2175 * and/or different from the directory change time. 2176 */ 2177 inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir)); 2178 ext4_update_dx_flag(dir); 2179 inode_inc_iversion(dir); 2180 err2 = ext4_mark_inode_dirty(handle, dir); 2181 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); 2182 err = ext4_handle_dirty_dirblock(handle, dir, bh); 2183 if (err) 2184 ext4_std_error(dir->i_sb, err); 2185 return err ? err : err2; 2186 } 2187 2188 static bool ext4_check_dx_root(struct inode *dir, struct dx_root *root) 2189 { 2190 struct fake_dirent *fde; 2191 const char *error_msg; 2192 unsigned int rlen; 2193 unsigned int blocksize = dir->i_sb->s_blocksize; 2194 char *blockend = (char *)root + dir->i_sb->s_blocksize; 2195 2196 fde = &root->dot; 2197 if (unlikely(fde->name_len != 1)) { 2198 error_msg = "invalid name_len for '.'"; 2199 goto corrupted; 2200 } 2201 if (unlikely(strncmp(root->dot_name, ".", fde->name_len))) { 2202 error_msg = "invalid name for '.'"; 2203 goto corrupted; 2204 } 2205 rlen = ext4_rec_len_from_disk(fde->rec_len, blocksize); 2206 if (unlikely((char *)fde + rlen >= blockend)) { 2207 error_msg = "invalid rec_len for '.'"; 2208 goto corrupted; 2209 } 2210 2211 fde = &root->dotdot; 2212 if (unlikely(fde->name_len != 2)) { 2213 error_msg = "invalid name_len for '..'"; 2214 goto corrupted; 2215 } 2216 if (unlikely(strncmp(root->dotdot_name, "..", fde->name_len))) { 2217 error_msg = "invalid name for '..'"; 2218 goto corrupted; 2219 } 2220 rlen = ext4_rec_len_from_disk(fde->rec_len, blocksize); 2221 if (unlikely((char *)fde + rlen >= blockend)) { 2222 error_msg = "invalid rec_len for '..'"; 2223 goto corrupted; 2224 } 2225 2226 return true; 2227 2228 corrupted: 2229 EXT4_ERROR_INODE(dir, "Corrupt dir, %s, running e2fsck is recommended", 2230 error_msg); 2231 return false; 2232 } 2233 2234 /* 2235 * This converts a one block unindexed directory to a 3 block indexed 2236 * directory, and adds the dentry to the indexed directory. 2237 */ 2238 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname, 2239 struct inode *dir, 2240 struct inode *inode, struct buffer_head *bh) 2241 { 2242 struct buffer_head *bh2; 2243 struct dx_root *root; 2244 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 2245 struct dx_entry *entries; 2246 struct ext4_dir_entry_2 *de, *de2; 2247 char *data2, *top; 2248 unsigned len; 2249 int retval; 2250 unsigned blocksize; 2251 ext4_lblk_t block; 2252 struct fake_dirent *fde; 2253 int csum_size = 0; 2254 2255 if (ext4_has_metadata_csum(inode->i_sb)) 2256 csum_size = sizeof(struct ext4_dir_entry_tail); 2257 2258 blocksize = dir->i_sb->s_blocksize; 2259 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino)); 2260 BUFFER_TRACE(bh, "get_write_access"); 2261 retval = ext4_journal_get_write_access(handle, dir->i_sb, bh, 2262 EXT4_JTR_NONE); 2263 if (retval) { 2264 ext4_std_error(dir->i_sb, retval); 2265 brelse(bh); 2266 return retval; 2267 } 2268 2269 root = (struct dx_root *) bh->b_data; 2270 if (!ext4_check_dx_root(dir, root)) { 2271 brelse(bh); 2272 return -EFSCORRUPTED; 2273 } 2274 2275 /* The 0th block becomes the root, move the dirents out */ 2276 fde = &root->dotdot; 2277 de = (struct ext4_dir_entry_2 *)((char *)fde + 2278 ext4_rec_len_from_disk(fde->rec_len, blocksize)); 2279 len = ((char *) root) + (blocksize - csum_size) - (char *) de; 2280 2281 /* Allocate new block for the 0th block's dirents */ 2282 bh2 = ext4_append(handle, dir, &block); 2283 if (IS_ERR(bh2)) { 2284 brelse(bh); 2285 return PTR_ERR(bh2); 2286 } 2287 ext4_set_inode_flag(dir, EXT4_INODE_INDEX); 2288 data2 = bh2->b_data; 2289 2290 memcpy(data2, de, len); 2291 memset(de, 0, len); /* wipe old data */ 2292 de = (struct ext4_dir_entry_2 *) data2; 2293 top = data2 + len; 2294 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top) { 2295 if (ext4_check_dir_entry(dir, NULL, de, bh2, data2, len, 2296 (char *)de - data2)) { 2297 brelse(bh2); 2298 brelse(bh); 2299 return -EFSCORRUPTED; 2300 } 2301 de = de2; 2302 } 2303 de->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) - 2304 (char *) de, blocksize); 2305 2306 if (csum_size) 2307 ext4_initialize_dirent_tail(bh2, blocksize); 2308 2309 /* Initialize the root; the dot dirents already exist */ 2310 de = (struct ext4_dir_entry_2 *) (&root->dotdot); 2311 de->rec_len = ext4_rec_len_to_disk( 2312 blocksize - ext4_dir_rec_len(2, NULL), blocksize); 2313 memset (&root->info, 0, sizeof(root->info)); 2314 root->info.info_length = sizeof(root->info); 2315 if (ext4_hash_in_dirent(dir)) 2316 root->info.hash_version = DX_HASH_SIPHASH; 2317 else 2318 root->info.hash_version = 2319 EXT4_SB(dir->i_sb)->s_def_hash_version; 2320 2321 entries = root->entries; 2322 dx_set_block(entries, 1); 2323 dx_set_count(entries, 1); 2324 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info))); 2325 2326 /* Initialize as for dx_probe */ 2327 fname->hinfo.hash_version = root->info.hash_version; 2328 if (fname->hinfo.hash_version <= DX_HASH_TEA) 2329 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; 2330 fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; 2331 2332 /* casefolded encrypted hashes are computed on fname setup */ 2333 if (!ext4_hash_in_dirent(dir)) { 2334 int err = ext4fs_dirhash(dir, fname_name(fname), 2335 fname_len(fname), &fname->hinfo); 2336 if (err < 0) { 2337 brelse(bh2); 2338 brelse(bh); 2339 return err; 2340 } 2341 } 2342 memset(frames, 0, sizeof(frames)); 2343 frame = frames; 2344 frame->entries = entries; 2345 frame->at = entries; 2346 frame->bh = bh; 2347 2348 retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 2349 if (retval) 2350 goto out_frames; 2351 retval = ext4_handle_dirty_dirblock(handle, dir, bh2); 2352 if (retval) 2353 goto out_frames; 2354 2355 de = do_split(handle,dir, &bh2, frame, &fname->hinfo); 2356 if (IS_ERR(de)) { 2357 retval = PTR_ERR(de); 2358 goto out_frames; 2359 } 2360 2361 retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2); 2362 out_frames: 2363 /* 2364 * Even if the block split failed, we have to properly write 2365 * out all the changes we did so far. Otherwise we can end up 2366 * with corrupted filesystem. 2367 */ 2368 if (retval) 2369 ext4_mark_inode_dirty(handle, dir); 2370 dx_release(frames); 2371 brelse(bh2); 2372 return retval; 2373 } 2374 2375 /* 2376 * ext4_add_entry() 2377 * 2378 * adds a file entry to the specified directory, using the same 2379 * semantics as ext4_find_entry(). It returns NULL if it failed. 2380 * 2381 * NOTE!! The inode part of 'de' is left at 0 - which means you 2382 * may not sleep between calling this and putting something into 2383 * the entry, as someone else might have used it while you slept. 2384 */ 2385 static int ext4_add_entry(handle_t *handle, struct dentry *dentry, 2386 struct inode *inode) 2387 { 2388 struct inode *dir = d_inode(dentry->d_parent); 2389 struct buffer_head *bh = NULL; 2390 struct ext4_dir_entry_2 *de; 2391 struct super_block *sb; 2392 struct ext4_filename fname; 2393 int retval; 2394 int dx_fallback=0; 2395 unsigned blocksize; 2396 ext4_lblk_t block, blocks; 2397 int csum_size = 0; 2398 2399 if (ext4_has_metadata_csum(inode->i_sb)) 2400 csum_size = sizeof(struct ext4_dir_entry_tail); 2401 2402 sb = dir->i_sb; 2403 blocksize = sb->s_blocksize; 2404 2405 if (fscrypt_is_nokey_name(dentry)) 2406 return -ENOKEY; 2407 2408 if (!generic_ci_validate_strict_name(dir, &dentry->d_name)) 2409 return -EINVAL; 2410 2411 retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname); 2412 if (retval) 2413 return retval; 2414 2415 if (ext4_has_inline_data(dir)) { 2416 retval = ext4_try_add_inline_entry(handle, &fname, dir, inode); 2417 if (retval < 0) 2418 goto out; 2419 if (retval == 1) { 2420 retval = 0; 2421 goto out; 2422 } 2423 } 2424 2425 if (is_dx(dir)) { 2426 retval = ext4_dx_add_entry(handle, &fname, dir, inode); 2427 if (!retval || (retval != ERR_BAD_DX_DIR)) 2428 goto out; 2429 /* Can we just ignore htree data? */ 2430 if (ext4_has_metadata_csum(sb)) { 2431 EXT4_ERROR_INODE(dir, 2432 "Directory has corrupted htree index."); 2433 retval = -EFSCORRUPTED; 2434 goto out; 2435 } 2436 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX); 2437 dx_fallback++; 2438 retval = ext4_mark_inode_dirty(handle, dir); 2439 if (unlikely(retval)) 2440 goto out; 2441 } 2442 blocks = dir->i_size >> sb->s_blocksize_bits; 2443 for (block = 0; block < blocks; block++) { 2444 bh = ext4_read_dirblock(dir, block, DIRENT); 2445 if (bh == NULL) { 2446 bh = ext4_bread(handle, dir, block, 2447 EXT4_GET_BLOCKS_CREATE); 2448 goto add_to_new_block; 2449 } 2450 if (IS_ERR(bh)) { 2451 retval = PTR_ERR(bh); 2452 bh = NULL; 2453 goto out; 2454 } 2455 retval = add_dirent_to_buf(handle, &fname, dir, inode, 2456 NULL, bh); 2457 if (retval != -ENOSPC) 2458 goto out; 2459 2460 if (blocks == 1 && !dx_fallback && 2461 ext4_has_feature_dir_index(sb)) { 2462 retval = make_indexed_dir(handle, &fname, dir, 2463 inode, bh); 2464 bh = NULL; /* make_indexed_dir releases bh */ 2465 goto out; 2466 } 2467 brelse(bh); 2468 } 2469 bh = ext4_append(handle, dir, &block); 2470 add_to_new_block: 2471 if (IS_ERR(bh)) { 2472 retval = PTR_ERR(bh); 2473 bh = NULL; 2474 goto out; 2475 } 2476 de = (struct ext4_dir_entry_2 *) bh->b_data; 2477 de->inode = 0; 2478 de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize); 2479 2480 if (csum_size) 2481 ext4_initialize_dirent_tail(bh, blocksize); 2482 2483 retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh); 2484 out: 2485 ext4_fname_free_filename(&fname); 2486 brelse(bh); 2487 if (retval == 0) 2488 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY); 2489 return retval; 2490 } 2491 2492 /* 2493 * Returns 0 for success, or a negative error value 2494 */ 2495 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname, 2496 struct inode *dir, struct inode *inode) 2497 { 2498 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 2499 struct dx_entry *entries, *at; 2500 struct buffer_head *bh; 2501 struct super_block *sb = dir->i_sb; 2502 struct ext4_dir_entry_2 *de; 2503 int restart; 2504 int err; 2505 2506 again: 2507 restart = 0; 2508 frame = dx_probe(fname, dir, NULL, frames); 2509 if (IS_ERR(frame)) 2510 return PTR_ERR(frame); 2511 entries = frame->entries; 2512 at = frame->at; 2513 bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT_HTREE); 2514 if (IS_ERR(bh)) { 2515 err = PTR_ERR(bh); 2516 bh = NULL; 2517 goto cleanup; 2518 } 2519 2520 BUFFER_TRACE(bh, "get_write_access"); 2521 err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE); 2522 if (err) 2523 goto journal_error; 2524 2525 err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh); 2526 if (err != -ENOSPC) 2527 goto cleanup; 2528 2529 err = 0; 2530 /* Block full, should compress but for now just split */ 2531 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n", 2532 dx_get_count(entries), dx_get_limit(entries))); 2533 /* Need to split index? */ 2534 if (dx_get_count(entries) == dx_get_limit(entries)) { 2535 ext4_lblk_t newblock; 2536 int levels = frame - frames + 1; 2537 unsigned int icount; 2538 int add_level = 1; 2539 struct dx_entry *entries2; 2540 struct dx_node *node2; 2541 struct buffer_head *bh2; 2542 2543 while (frame > frames) { 2544 if (dx_get_count((frame - 1)->entries) < 2545 dx_get_limit((frame - 1)->entries)) { 2546 add_level = 0; 2547 break; 2548 } 2549 frame--; /* split higher index block */ 2550 at = frame->at; 2551 entries = frame->entries; 2552 restart = 1; 2553 } 2554 if (add_level && levels == ext4_dir_htree_level(sb)) { 2555 ext4_warning(sb, "Directory (ino: %lu) index full, " 2556 "reach max htree level :%d", 2557 dir->i_ino, levels); 2558 if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) { 2559 ext4_warning(sb, "Large directory feature is " 2560 "not enabled on this " 2561 "filesystem"); 2562 } 2563 err = -ENOSPC; 2564 goto cleanup; 2565 } 2566 icount = dx_get_count(entries); 2567 bh2 = ext4_append(handle, dir, &newblock); 2568 if (IS_ERR(bh2)) { 2569 err = PTR_ERR(bh2); 2570 goto cleanup; 2571 } 2572 node2 = (struct dx_node *)(bh2->b_data); 2573 entries2 = node2->entries; 2574 memset(&node2->fake, 0, sizeof(struct fake_dirent)); 2575 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize, 2576 sb->s_blocksize); 2577 BUFFER_TRACE(frame->bh, "get_write_access"); 2578 err = ext4_journal_get_write_access(handle, sb, frame->bh, 2579 EXT4_JTR_NONE); 2580 if (err) 2581 goto journal_error; 2582 if (!add_level) { 2583 unsigned icount1 = icount/2, icount2 = icount - icount1; 2584 unsigned hash2 = dx_get_hash(entries + icount1); 2585 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n", 2586 icount1, icount2)); 2587 2588 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */ 2589 err = ext4_journal_get_write_access(handle, sb, 2590 (frame - 1)->bh, 2591 EXT4_JTR_NONE); 2592 if (err) 2593 goto journal_error; 2594 2595 memcpy((char *) entries2, (char *) (entries + icount1), 2596 icount2 * sizeof(struct dx_entry)); 2597 dx_set_count(entries, icount1); 2598 dx_set_count(entries2, icount2); 2599 dx_set_limit(entries2, dx_node_limit(dir)); 2600 2601 /* Which index block gets the new entry? */ 2602 if (at - entries >= icount1) { 2603 frame->at = at - entries - icount1 + entries2; 2604 frame->entries = entries = entries2; 2605 swap(frame->bh, bh2); 2606 } 2607 dx_insert_block((frame - 1), hash2, newblock); 2608 dxtrace(dx_show_index("node", frame->entries)); 2609 dxtrace(dx_show_index("node", 2610 ((struct dx_node *) bh2->b_data)->entries)); 2611 err = ext4_handle_dirty_dx_node(handle, dir, bh2); 2612 if (err) 2613 goto journal_error; 2614 brelse (bh2); 2615 err = ext4_handle_dirty_dx_node(handle, dir, 2616 (frame - 1)->bh); 2617 if (err) 2618 goto journal_error; 2619 err = ext4_handle_dirty_dx_node(handle, dir, 2620 frame->bh); 2621 if (restart || err) 2622 goto journal_error; 2623 } else { 2624 struct dx_root *dxroot; 2625 memcpy((char *) entries2, (char *) entries, 2626 icount * sizeof(struct dx_entry)); 2627 dx_set_limit(entries2, dx_node_limit(dir)); 2628 2629 /* Set up root */ 2630 dx_set_count(entries, 1); 2631 dx_set_block(entries + 0, newblock); 2632 dxroot = (struct dx_root *)frames[0].bh->b_data; 2633 dxroot->info.indirect_levels += 1; 2634 dxtrace(printk(KERN_DEBUG 2635 "Creating %d level index...\n", 2636 dxroot->info.indirect_levels)); 2637 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 2638 if (err) 2639 goto journal_error; 2640 err = ext4_handle_dirty_dx_node(handle, dir, bh2); 2641 brelse(bh2); 2642 restart = 1; 2643 goto journal_error; 2644 } 2645 } 2646 de = do_split(handle, dir, &bh, frame, &fname->hinfo); 2647 if (IS_ERR(de)) { 2648 err = PTR_ERR(de); 2649 goto cleanup; 2650 } 2651 err = add_dirent_to_buf(handle, fname, dir, inode, de, bh); 2652 goto cleanup; 2653 2654 journal_error: 2655 ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */ 2656 cleanup: 2657 brelse(bh); 2658 dx_release(frames); 2659 /* @restart is true means htree-path has been changed, we need to 2660 * repeat dx_probe() to find out valid htree-path 2661 */ 2662 if (restart && err == 0) 2663 goto again; 2664 return err; 2665 } 2666 2667 /* 2668 * ext4_generic_delete_entry deletes a directory entry by merging it 2669 * with the previous entry 2670 */ 2671 int ext4_generic_delete_entry(struct inode *dir, 2672 struct ext4_dir_entry_2 *de_del, 2673 struct buffer_head *bh, 2674 void *entry_buf, 2675 int buf_size, 2676 int csum_size) 2677 { 2678 struct ext4_dir_entry_2 *de, *pde; 2679 unsigned int blocksize = dir->i_sb->s_blocksize; 2680 int i; 2681 2682 i = 0; 2683 pde = NULL; 2684 de = entry_buf; 2685 while (i < buf_size - csum_size) { 2686 if (ext4_check_dir_entry(dir, NULL, de, bh, 2687 entry_buf, buf_size, i)) 2688 return -EFSCORRUPTED; 2689 if (de == de_del) { 2690 if (pde) { 2691 pde->rec_len = ext4_rec_len_to_disk( 2692 ext4_rec_len_from_disk(pde->rec_len, 2693 blocksize) + 2694 ext4_rec_len_from_disk(de->rec_len, 2695 blocksize), 2696 blocksize); 2697 2698 /* wipe entire dir_entry */ 2699 memset(de, 0, ext4_rec_len_from_disk(de->rec_len, 2700 blocksize)); 2701 } else { 2702 /* wipe dir_entry excluding the rec_len field */ 2703 de->inode = 0; 2704 memset(&de->name_len, 0, 2705 ext4_rec_len_from_disk(de->rec_len, 2706 blocksize) - 2707 offsetof(struct ext4_dir_entry_2, 2708 name_len)); 2709 } 2710 2711 inode_inc_iversion(dir); 2712 return 0; 2713 } 2714 i += ext4_rec_len_from_disk(de->rec_len, blocksize); 2715 pde = de; 2716 de = ext4_next_entry(de, blocksize); 2717 } 2718 return -ENOENT; 2719 } 2720 2721 static int ext4_delete_entry(handle_t *handle, 2722 struct inode *dir, 2723 struct ext4_dir_entry_2 *de_del, 2724 struct buffer_head *bh) 2725 { 2726 int err, csum_size = 0; 2727 2728 if (ext4_has_inline_data(dir)) { 2729 int has_inline_data = 1; 2730 err = ext4_delete_inline_entry(handle, dir, de_del, bh, 2731 &has_inline_data); 2732 if (has_inline_data) 2733 return err; 2734 } 2735 2736 if (ext4_has_metadata_csum(dir->i_sb)) 2737 csum_size = sizeof(struct ext4_dir_entry_tail); 2738 2739 BUFFER_TRACE(bh, "get_write_access"); 2740 err = ext4_journal_get_write_access(handle, dir->i_sb, bh, 2741 EXT4_JTR_NONE); 2742 if (unlikely(err)) 2743 goto out; 2744 2745 err = ext4_generic_delete_entry(dir, de_del, bh, bh->b_data, 2746 dir->i_sb->s_blocksize, csum_size); 2747 if (err) 2748 goto out; 2749 2750 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); 2751 err = ext4_handle_dirty_dirblock(handle, dir, bh); 2752 if (unlikely(err)) 2753 goto out; 2754 2755 return 0; 2756 out: 2757 if (err != -ENOENT) 2758 ext4_std_error(dir->i_sb, err); 2759 return err; 2760 } 2761 2762 /* 2763 * Set directory link count to 1 if nlinks > EXT4_LINK_MAX, or if nlinks == 2 2764 * since this indicates that nlinks count was previously 1 to avoid overflowing 2765 * the 16-bit i_links_count field on disk. Directories with i_nlink == 1 mean 2766 * that subdirectory link counts are not being maintained accurately. 2767 * 2768 * The caller has already checked for i_nlink overflow in case the DIR_LINK 2769 * feature is not enabled and returned -EMLINK. The is_dx() check is a proxy 2770 * for checking S_ISDIR(inode) (since the INODE_INDEX feature will not be set 2771 * on regular files) and to avoid creating huge/slow non-HTREE directories. 2772 */ 2773 static void ext4_inc_count(struct inode *inode) 2774 { 2775 inc_nlink(inode); 2776 if (is_dx(inode) && 2777 (inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2)) 2778 set_nlink(inode, 1); 2779 } 2780 2781 /* 2782 * If a directory had nlink == 1, then we should let it be 1. This indicates 2783 * directory has >EXT4_LINK_MAX subdirs. 2784 */ 2785 static void ext4_dec_count(struct inode *inode) 2786 { 2787 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2) 2788 drop_nlink(inode); 2789 } 2790 2791 2792 /* 2793 * Add non-directory inode to a directory. On success, the inode reference is 2794 * consumed by dentry is instantiation. This is also indicated by clearing of 2795 * *inodep pointer. On failure, the caller is responsible for dropping the 2796 * inode reference in the safe context. 2797 */ 2798 static int ext4_add_nondir(handle_t *handle, 2799 struct dentry *dentry, struct inode **inodep) 2800 { 2801 struct inode *dir = d_inode(dentry->d_parent); 2802 struct inode *inode = *inodep; 2803 int err = ext4_add_entry(handle, dentry, inode); 2804 if (!err) { 2805 err = ext4_mark_inode_dirty(handle, inode); 2806 if (IS_DIRSYNC(dir)) 2807 ext4_handle_sync(handle); 2808 d_instantiate_new(dentry, inode); 2809 *inodep = NULL; 2810 return err; 2811 } 2812 drop_nlink(inode); 2813 ext4_mark_inode_dirty(handle, inode); 2814 ext4_orphan_add(handle, inode); 2815 unlock_new_inode(inode); 2816 return err; 2817 } 2818 2819 /* 2820 * By the time this is called, we already have created 2821 * the directory cache entry for the new file, but it 2822 * is so far negative - it has no inode. 2823 * 2824 * If the create succeeds, we fill in the inode information 2825 * with d_instantiate(). 2826 */ 2827 static int ext4_create(struct mnt_idmap *idmap, struct inode *dir, 2828 struct dentry *dentry, umode_t mode, bool excl) 2829 { 2830 handle_t *handle; 2831 struct inode *inode; 2832 int err, credits, retries = 0; 2833 2834 err = dquot_initialize(dir); 2835 if (err) 2836 return err; 2837 2838 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2839 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2840 retry: 2841 inode = ext4_new_inode_start_handle(idmap, dir, mode, &dentry->d_name, 2842 0, NULL, EXT4_HT_DIR, credits); 2843 handle = ext4_journal_current_handle(); 2844 err = PTR_ERR(inode); 2845 if (!IS_ERR(inode)) { 2846 inode->i_op = &ext4_file_inode_operations; 2847 inode->i_fop = &ext4_file_operations; 2848 ext4_set_aops(inode); 2849 err = ext4_add_nondir(handle, dentry, &inode); 2850 if (!err) 2851 ext4_fc_track_create(handle, dentry); 2852 } 2853 if (handle) 2854 ext4_journal_stop(handle); 2855 if (!IS_ERR_OR_NULL(inode)) 2856 iput(inode); 2857 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2858 goto retry; 2859 return err; 2860 } 2861 2862 static int ext4_mknod(struct mnt_idmap *idmap, struct inode *dir, 2863 struct dentry *dentry, umode_t mode, dev_t rdev) 2864 { 2865 handle_t *handle; 2866 struct inode *inode; 2867 int err, credits, retries = 0; 2868 2869 err = dquot_initialize(dir); 2870 if (err) 2871 return err; 2872 2873 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2874 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2875 retry: 2876 inode = ext4_new_inode_start_handle(idmap, dir, mode, &dentry->d_name, 2877 0, NULL, EXT4_HT_DIR, credits); 2878 handle = ext4_journal_current_handle(); 2879 err = PTR_ERR(inode); 2880 if (!IS_ERR(inode)) { 2881 init_special_inode(inode, inode->i_mode, rdev); 2882 inode->i_op = &ext4_special_inode_operations; 2883 err = ext4_add_nondir(handle, dentry, &inode); 2884 if (!err) 2885 ext4_fc_track_create(handle, dentry); 2886 } 2887 if (handle) 2888 ext4_journal_stop(handle); 2889 if (!IS_ERR_OR_NULL(inode)) 2890 iput(inode); 2891 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2892 goto retry; 2893 return err; 2894 } 2895 2896 static int ext4_tmpfile(struct mnt_idmap *idmap, struct inode *dir, 2897 struct file *file, umode_t mode) 2898 { 2899 handle_t *handle; 2900 struct inode *inode; 2901 int err, retries = 0; 2902 2903 err = dquot_initialize(dir); 2904 if (err) 2905 return err; 2906 2907 retry: 2908 inode = ext4_new_inode_start_handle(idmap, dir, mode, 2909 NULL, 0, NULL, 2910 EXT4_HT_DIR, 2911 EXT4_MAXQUOTAS_TRANS_BLOCKS(dir->i_sb) + 2912 4 + EXT4_XATTR_TRANS_BLOCKS); 2913 handle = ext4_journal_current_handle(); 2914 err = PTR_ERR(inode); 2915 if (!IS_ERR(inode)) { 2916 inode->i_op = &ext4_file_inode_operations; 2917 inode->i_fop = &ext4_file_operations; 2918 ext4_set_aops(inode); 2919 d_tmpfile(file, inode); 2920 err = ext4_orphan_add(handle, inode); 2921 if (err) 2922 goto err_unlock_inode; 2923 mark_inode_dirty(inode); 2924 unlock_new_inode(inode); 2925 } 2926 if (handle) 2927 ext4_journal_stop(handle); 2928 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2929 goto retry; 2930 return finish_open_simple(file, err); 2931 err_unlock_inode: 2932 ext4_journal_stop(handle); 2933 unlock_new_inode(inode); 2934 return err; 2935 } 2936 2937 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode, 2938 struct ext4_dir_entry_2 *de, 2939 int blocksize, int csum_size, 2940 unsigned int parent_ino, int dotdot_real_len) 2941 { 2942 de->inode = cpu_to_le32(inode->i_ino); 2943 de->name_len = 1; 2944 de->rec_len = ext4_rec_len_to_disk(ext4_dir_rec_len(de->name_len, NULL), 2945 blocksize); 2946 strcpy(de->name, "."); 2947 ext4_set_de_type(inode->i_sb, de, S_IFDIR); 2948 2949 de = ext4_next_entry(de, blocksize); 2950 de->inode = cpu_to_le32(parent_ino); 2951 de->name_len = 2; 2952 if (!dotdot_real_len) 2953 de->rec_len = ext4_rec_len_to_disk(blocksize - 2954 (csum_size + ext4_dir_rec_len(1, NULL)), 2955 blocksize); 2956 else 2957 de->rec_len = ext4_rec_len_to_disk( 2958 ext4_dir_rec_len(de->name_len, NULL), 2959 blocksize); 2960 strcpy(de->name, ".."); 2961 ext4_set_de_type(inode->i_sb, de, S_IFDIR); 2962 2963 return ext4_next_entry(de, blocksize); 2964 } 2965 2966 int ext4_init_new_dir(handle_t *handle, struct inode *dir, 2967 struct inode *inode) 2968 { 2969 struct buffer_head *dir_block = NULL; 2970 struct ext4_dir_entry_2 *de; 2971 ext4_lblk_t block = 0; 2972 unsigned int blocksize = dir->i_sb->s_blocksize; 2973 int csum_size = 0; 2974 int err; 2975 2976 if (ext4_has_metadata_csum(dir->i_sb)) 2977 csum_size = sizeof(struct ext4_dir_entry_tail); 2978 2979 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) { 2980 err = ext4_try_create_inline_dir(handle, dir, inode); 2981 if (err < 0 && err != -ENOSPC) 2982 goto out; 2983 if (!err) 2984 goto out; 2985 } 2986 2987 inode->i_size = 0; 2988 dir_block = ext4_append(handle, inode, &block); 2989 if (IS_ERR(dir_block)) 2990 return PTR_ERR(dir_block); 2991 de = (struct ext4_dir_entry_2 *)dir_block->b_data; 2992 ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0); 2993 set_nlink(inode, 2); 2994 if (csum_size) 2995 ext4_initialize_dirent_tail(dir_block, blocksize); 2996 2997 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata"); 2998 err = ext4_handle_dirty_dirblock(handle, inode, dir_block); 2999 if (err) 3000 goto out; 3001 set_buffer_verified(dir_block); 3002 out: 3003 brelse(dir_block); 3004 return err; 3005 } 3006 3007 static int ext4_mkdir(struct mnt_idmap *idmap, struct inode *dir, 3008 struct dentry *dentry, umode_t mode) 3009 { 3010 handle_t *handle; 3011 struct inode *inode; 3012 int err, err2 = 0, credits, retries = 0; 3013 3014 if (EXT4_DIR_LINK_MAX(dir)) 3015 return -EMLINK; 3016 3017 err = dquot_initialize(dir); 3018 if (err) 3019 return err; 3020 3021 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3022 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 3023 retry: 3024 inode = ext4_new_inode_start_handle(idmap, dir, S_IFDIR | mode, 3025 &dentry->d_name, 3026 0, NULL, EXT4_HT_DIR, credits); 3027 handle = ext4_journal_current_handle(); 3028 err = PTR_ERR(inode); 3029 if (IS_ERR(inode)) 3030 goto out_stop; 3031 3032 inode->i_op = &ext4_dir_inode_operations; 3033 inode->i_fop = &ext4_dir_operations; 3034 err = ext4_init_new_dir(handle, dir, inode); 3035 if (err) 3036 goto out_clear_inode; 3037 err = ext4_mark_inode_dirty(handle, inode); 3038 if (!err) 3039 err = ext4_add_entry(handle, dentry, inode); 3040 if (err) { 3041 out_clear_inode: 3042 clear_nlink(inode); 3043 ext4_orphan_add(handle, inode); 3044 unlock_new_inode(inode); 3045 err2 = ext4_mark_inode_dirty(handle, inode); 3046 if (unlikely(err2)) 3047 err = err2; 3048 ext4_journal_stop(handle); 3049 iput(inode); 3050 goto out_retry; 3051 } 3052 ext4_inc_count(dir); 3053 3054 ext4_update_dx_flag(dir); 3055 err = ext4_mark_inode_dirty(handle, dir); 3056 if (err) 3057 goto out_clear_inode; 3058 d_instantiate_new(dentry, inode); 3059 ext4_fc_track_create(handle, dentry); 3060 if (IS_DIRSYNC(dir)) 3061 ext4_handle_sync(handle); 3062 3063 out_stop: 3064 if (handle) 3065 ext4_journal_stop(handle); 3066 out_retry: 3067 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 3068 goto retry; 3069 return err; 3070 } 3071 3072 /* 3073 * routine to check that the specified directory is empty (for rmdir) 3074 */ 3075 bool ext4_empty_dir(struct inode *inode) 3076 { 3077 unsigned int offset; 3078 struct buffer_head *bh; 3079 struct ext4_dir_entry_2 *de; 3080 struct super_block *sb; 3081 3082 if (ext4_has_inline_data(inode)) { 3083 int has_inline_data = 1; 3084 int ret; 3085 3086 ret = empty_inline_dir(inode, &has_inline_data); 3087 if (has_inline_data) 3088 return ret; 3089 } 3090 3091 sb = inode->i_sb; 3092 if (inode->i_size < ext4_dir_rec_len(1, NULL) + 3093 ext4_dir_rec_len(2, NULL)) { 3094 EXT4_ERROR_INODE(inode, "invalid size"); 3095 return false; 3096 } 3097 bh = ext4_read_dirblock(inode, 0, EITHER); 3098 if (IS_ERR(bh)) 3099 return false; 3100 3101 de = (struct ext4_dir_entry_2 *) bh->b_data; 3102 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size, 3103 0) || 3104 le32_to_cpu(de->inode) != inode->i_ino || strcmp(".", de->name)) { 3105 ext4_warning_inode(inode, "directory missing '.'"); 3106 brelse(bh); 3107 return false; 3108 } 3109 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); 3110 de = ext4_next_entry(de, sb->s_blocksize); 3111 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size, 3112 offset) || 3113 le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) { 3114 ext4_warning_inode(inode, "directory missing '..'"); 3115 brelse(bh); 3116 return false; 3117 } 3118 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); 3119 while (offset < inode->i_size) { 3120 if (!(offset & (sb->s_blocksize - 1))) { 3121 unsigned int lblock; 3122 brelse(bh); 3123 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb); 3124 bh = ext4_read_dirblock(inode, lblock, EITHER); 3125 if (bh == NULL) { 3126 offset += sb->s_blocksize; 3127 continue; 3128 } 3129 if (IS_ERR(bh)) 3130 return false; 3131 } 3132 de = (struct ext4_dir_entry_2 *) (bh->b_data + 3133 (offset & (sb->s_blocksize - 1))); 3134 if (ext4_check_dir_entry(inode, NULL, de, bh, 3135 bh->b_data, bh->b_size, offset) || 3136 le32_to_cpu(de->inode)) { 3137 brelse(bh); 3138 return false; 3139 } 3140 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); 3141 } 3142 brelse(bh); 3143 return true; 3144 } 3145 3146 static int ext4_rmdir(struct inode *dir, struct dentry *dentry) 3147 { 3148 int retval; 3149 struct inode *inode; 3150 struct buffer_head *bh; 3151 struct ext4_dir_entry_2 *de; 3152 handle_t *handle = NULL; 3153 3154 if (unlikely(ext4_forced_shutdown(dir->i_sb))) 3155 return -EIO; 3156 3157 /* Initialize quotas before so that eventual writes go in 3158 * separate transaction */ 3159 retval = dquot_initialize(dir); 3160 if (retval) 3161 return retval; 3162 retval = dquot_initialize(d_inode(dentry)); 3163 if (retval) 3164 return retval; 3165 3166 retval = -ENOENT; 3167 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); 3168 if (IS_ERR(bh)) 3169 return PTR_ERR(bh); 3170 if (!bh) 3171 goto end_rmdir; 3172 3173 inode = d_inode(dentry); 3174 3175 retval = -EFSCORRUPTED; 3176 if (le32_to_cpu(de->inode) != inode->i_ino) 3177 goto end_rmdir; 3178 3179 retval = -ENOTEMPTY; 3180 if (!ext4_empty_dir(inode)) 3181 goto end_rmdir; 3182 3183 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3184 EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); 3185 if (IS_ERR(handle)) { 3186 retval = PTR_ERR(handle); 3187 handle = NULL; 3188 goto end_rmdir; 3189 } 3190 3191 if (IS_DIRSYNC(dir)) 3192 ext4_handle_sync(handle); 3193 3194 retval = ext4_delete_entry(handle, dir, de, bh); 3195 if (retval) 3196 goto end_rmdir; 3197 if (!EXT4_DIR_LINK_EMPTY(inode)) 3198 ext4_warning_inode(inode, 3199 "empty directory '%.*s' has too many links (%u)", 3200 dentry->d_name.len, dentry->d_name.name, 3201 inode->i_nlink); 3202 inode_inc_iversion(inode); 3203 clear_nlink(inode); 3204 /* There's no need to set i_disksize: the fact that i_nlink is 3205 * zero will ensure that the right thing happens during any 3206 * recovery. */ 3207 inode->i_size = 0; 3208 ext4_orphan_add(handle, inode); 3209 inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir)); 3210 inode_set_ctime_current(inode); 3211 retval = ext4_mark_inode_dirty(handle, inode); 3212 if (retval) 3213 goto end_rmdir; 3214 ext4_dec_count(dir); 3215 ext4_update_dx_flag(dir); 3216 ext4_fc_track_unlink(handle, dentry); 3217 retval = ext4_mark_inode_dirty(handle, dir); 3218 3219 /* VFS negative dentries are incompatible with Encoding and 3220 * Case-insensitiveness. Eventually we'll want avoid 3221 * invalidating the dentries here, alongside with returning the 3222 * negative dentries at ext4_lookup(), when it is better 3223 * supported by the VFS for the CI case. 3224 */ 3225 if (IS_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir)) 3226 d_invalidate(dentry); 3227 3228 end_rmdir: 3229 brelse(bh); 3230 if (handle) 3231 ext4_journal_stop(handle); 3232 return retval; 3233 } 3234 3235 int __ext4_unlink(struct inode *dir, const struct qstr *d_name, 3236 struct inode *inode, 3237 struct dentry *dentry /* NULL during fast_commit recovery */) 3238 { 3239 int retval = -ENOENT; 3240 struct buffer_head *bh; 3241 struct ext4_dir_entry_2 *de; 3242 handle_t *handle; 3243 int skip_remove_dentry = 0; 3244 3245 /* 3246 * Keep this outside the transaction; it may have to set up the 3247 * directory's encryption key, which isn't GFP_NOFS-safe. 3248 */ 3249 bh = ext4_find_entry(dir, d_name, &de, NULL); 3250 if (IS_ERR(bh)) 3251 return PTR_ERR(bh); 3252 3253 if (!bh) 3254 return -ENOENT; 3255 3256 if (le32_to_cpu(de->inode) != inode->i_ino) { 3257 /* 3258 * It's okay if we find dont find dentry which matches 3259 * the inode. That's because it might have gotten 3260 * renamed to a different inode number 3261 */ 3262 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY) 3263 skip_remove_dentry = 1; 3264 else 3265 goto out_bh; 3266 } 3267 3268 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3269 EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); 3270 if (IS_ERR(handle)) { 3271 retval = PTR_ERR(handle); 3272 goto out_bh; 3273 } 3274 3275 if (IS_DIRSYNC(dir)) 3276 ext4_handle_sync(handle); 3277 3278 if (!skip_remove_dentry) { 3279 retval = ext4_delete_entry(handle, dir, de, bh); 3280 if (retval) 3281 goto out_handle; 3282 inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir)); 3283 ext4_update_dx_flag(dir); 3284 retval = ext4_mark_inode_dirty(handle, dir); 3285 if (retval) 3286 goto out_handle; 3287 } else { 3288 retval = 0; 3289 } 3290 if (inode->i_nlink == 0) 3291 ext4_warning_inode(inode, "Deleting file '%.*s' with no links", 3292 d_name->len, d_name->name); 3293 else 3294 drop_nlink(inode); 3295 if (!inode->i_nlink) 3296 ext4_orphan_add(handle, inode); 3297 inode_set_ctime_current(inode); 3298 retval = ext4_mark_inode_dirty(handle, inode); 3299 if (dentry && !retval) 3300 ext4_fc_track_unlink(handle, dentry); 3301 out_handle: 3302 ext4_journal_stop(handle); 3303 out_bh: 3304 brelse(bh); 3305 return retval; 3306 } 3307 3308 static int ext4_unlink(struct inode *dir, struct dentry *dentry) 3309 { 3310 int retval; 3311 3312 if (unlikely(ext4_forced_shutdown(dir->i_sb))) 3313 return -EIO; 3314 3315 trace_ext4_unlink_enter(dir, dentry); 3316 /* 3317 * Initialize quotas before so that eventual writes go 3318 * in separate transaction 3319 */ 3320 retval = dquot_initialize(dir); 3321 if (retval) 3322 goto out_trace; 3323 retval = dquot_initialize(d_inode(dentry)); 3324 if (retval) 3325 goto out_trace; 3326 3327 retval = __ext4_unlink(dir, &dentry->d_name, d_inode(dentry), dentry); 3328 3329 /* VFS negative dentries are incompatible with Encoding and 3330 * Case-insensitiveness. Eventually we'll want avoid 3331 * invalidating the dentries here, alongside with returning the 3332 * negative dentries at ext4_lookup(), when it is better 3333 * supported by the VFS for the CI case. 3334 */ 3335 if (IS_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir)) 3336 d_invalidate(dentry); 3337 3338 out_trace: 3339 trace_ext4_unlink_exit(dentry, retval); 3340 return retval; 3341 } 3342 3343 static int ext4_init_symlink_block(handle_t *handle, struct inode *inode, 3344 struct fscrypt_str *disk_link) 3345 { 3346 struct buffer_head *bh; 3347 char *kaddr; 3348 int err = 0; 3349 3350 bh = ext4_bread(handle, inode, 0, EXT4_GET_BLOCKS_CREATE); 3351 if (IS_ERR(bh)) 3352 return PTR_ERR(bh); 3353 3354 BUFFER_TRACE(bh, "get_write_access"); 3355 err = ext4_journal_get_write_access(handle, inode->i_sb, bh, EXT4_JTR_NONE); 3356 if (err) 3357 goto out; 3358 3359 kaddr = (char *)bh->b_data; 3360 memcpy(kaddr, disk_link->name, disk_link->len); 3361 inode->i_size = disk_link->len - 1; 3362 EXT4_I(inode)->i_disksize = inode->i_size; 3363 err = ext4_handle_dirty_metadata(handle, inode, bh); 3364 out: 3365 brelse(bh); 3366 return err; 3367 } 3368 3369 static int ext4_symlink(struct mnt_idmap *idmap, struct inode *dir, 3370 struct dentry *dentry, const char *symname) 3371 { 3372 handle_t *handle; 3373 struct inode *inode; 3374 int err, len = strlen(symname); 3375 int credits; 3376 struct fscrypt_str disk_link; 3377 int retries = 0; 3378 3379 if (unlikely(ext4_forced_shutdown(dir->i_sb))) 3380 return -EIO; 3381 3382 err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize, 3383 &disk_link); 3384 if (err) 3385 return err; 3386 3387 err = dquot_initialize(dir); 3388 if (err) 3389 return err; 3390 3391 /* 3392 * EXT4_INDEX_EXTRA_TRANS_BLOCKS for addition of entry into the 3393 * directory. +3 for inode, inode bitmap, group descriptor allocation. 3394 * EXT4_DATA_TRANS_BLOCKS for the data block allocation and 3395 * modification. 3396 */ 3397 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3398 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3; 3399 retry: 3400 inode = ext4_new_inode_start_handle(idmap, dir, S_IFLNK|S_IRWXUGO, 3401 &dentry->d_name, 0, NULL, 3402 EXT4_HT_DIR, credits); 3403 handle = ext4_journal_current_handle(); 3404 if (IS_ERR(inode)) { 3405 if (handle) 3406 ext4_journal_stop(handle); 3407 err = PTR_ERR(inode); 3408 goto out_retry; 3409 } 3410 3411 if (IS_ENCRYPTED(inode)) { 3412 err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link); 3413 if (err) 3414 goto err_drop_inode; 3415 inode->i_op = &ext4_encrypted_symlink_inode_operations; 3416 } else { 3417 if ((disk_link.len > EXT4_N_BLOCKS * 4)) { 3418 inode->i_op = &ext4_symlink_inode_operations; 3419 } else { 3420 inode->i_op = &ext4_fast_symlink_inode_operations; 3421 inode->i_link = (char *)&EXT4_I(inode)->i_data; 3422 } 3423 } 3424 3425 if ((disk_link.len > EXT4_N_BLOCKS * 4)) { 3426 /* alloc symlink block and fill it */ 3427 err = ext4_init_symlink_block(handle, inode, &disk_link); 3428 if (err) 3429 goto err_drop_inode; 3430 } else { 3431 /* clear the extent format for fast symlink */ 3432 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS); 3433 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name, 3434 disk_link.len); 3435 inode->i_size = disk_link.len - 1; 3436 EXT4_I(inode)->i_disksize = inode->i_size; 3437 } 3438 err = ext4_add_nondir(handle, dentry, &inode); 3439 if (handle) 3440 ext4_journal_stop(handle); 3441 iput(inode); 3442 goto out_retry; 3443 3444 err_drop_inode: 3445 clear_nlink(inode); 3446 ext4_mark_inode_dirty(handle, inode); 3447 ext4_orphan_add(handle, inode); 3448 unlock_new_inode(inode); 3449 if (handle) 3450 ext4_journal_stop(handle); 3451 iput(inode); 3452 out_retry: 3453 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 3454 goto retry; 3455 if (disk_link.name != (unsigned char *)symname) 3456 kfree(disk_link.name); 3457 return err; 3458 } 3459 3460 int __ext4_link(struct inode *dir, struct inode *inode, struct dentry *dentry) 3461 { 3462 handle_t *handle; 3463 int err, retries = 0; 3464 retry: 3465 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3466 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3467 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1); 3468 if (IS_ERR(handle)) 3469 return PTR_ERR(handle); 3470 3471 if (IS_DIRSYNC(dir)) 3472 ext4_handle_sync(handle); 3473 3474 inode_set_ctime_current(inode); 3475 ext4_inc_count(inode); 3476 ihold(inode); 3477 3478 err = ext4_add_entry(handle, dentry, inode); 3479 if (!err) { 3480 err = ext4_mark_inode_dirty(handle, inode); 3481 /* this can happen only for tmpfile being 3482 * linked the first time 3483 */ 3484 if (inode->i_nlink == 1) 3485 ext4_orphan_del(handle, inode); 3486 d_instantiate(dentry, inode); 3487 ext4_fc_track_link(handle, dentry); 3488 } else { 3489 drop_nlink(inode); 3490 iput(inode); 3491 } 3492 ext4_journal_stop(handle); 3493 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 3494 goto retry; 3495 return err; 3496 } 3497 3498 static int ext4_link(struct dentry *old_dentry, 3499 struct inode *dir, struct dentry *dentry) 3500 { 3501 struct inode *inode = d_inode(old_dentry); 3502 int err; 3503 3504 if (inode->i_nlink >= EXT4_LINK_MAX) 3505 return -EMLINK; 3506 3507 err = fscrypt_prepare_link(old_dentry, dir, dentry); 3508 if (err) 3509 return err; 3510 3511 if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) && 3512 (!projid_eq(EXT4_I(dir)->i_projid, 3513 EXT4_I(old_dentry->d_inode)->i_projid))) 3514 return -EXDEV; 3515 3516 err = dquot_initialize(dir); 3517 if (err) 3518 return err; 3519 return __ext4_link(dir, inode, dentry); 3520 } 3521 3522 /* 3523 * Try to find buffer head where contains the parent block. 3524 * It should be the inode block if it is inlined or the 1st block 3525 * if it is a normal dir. 3526 */ 3527 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle, 3528 struct inode *inode, 3529 int *retval, 3530 struct ext4_dir_entry_2 **parent_de, 3531 int *inlined) 3532 { 3533 struct buffer_head *bh; 3534 3535 if (!ext4_has_inline_data(inode)) { 3536 struct ext4_dir_entry_2 *de; 3537 unsigned int offset; 3538 3539 bh = ext4_read_dirblock(inode, 0, EITHER); 3540 if (IS_ERR(bh)) { 3541 *retval = PTR_ERR(bh); 3542 return NULL; 3543 } 3544 3545 de = (struct ext4_dir_entry_2 *) bh->b_data; 3546 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, 3547 bh->b_size, 0) || 3548 le32_to_cpu(de->inode) != inode->i_ino || 3549 strcmp(".", de->name)) { 3550 EXT4_ERROR_INODE(inode, "directory missing '.'"); 3551 brelse(bh); 3552 *retval = -EFSCORRUPTED; 3553 return NULL; 3554 } 3555 offset = ext4_rec_len_from_disk(de->rec_len, 3556 inode->i_sb->s_blocksize); 3557 de = ext4_next_entry(de, inode->i_sb->s_blocksize); 3558 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, 3559 bh->b_size, offset) || 3560 le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) { 3561 EXT4_ERROR_INODE(inode, "directory missing '..'"); 3562 brelse(bh); 3563 *retval = -EFSCORRUPTED; 3564 return NULL; 3565 } 3566 *parent_de = de; 3567 3568 return bh; 3569 } 3570 3571 *inlined = 1; 3572 return ext4_get_first_inline_block(inode, parent_de, retval); 3573 } 3574 3575 struct ext4_renament { 3576 struct inode *dir; 3577 struct dentry *dentry; 3578 struct inode *inode; 3579 bool is_dir; 3580 int dir_nlink_delta; 3581 3582 /* entry for "dentry" */ 3583 struct buffer_head *bh; 3584 struct ext4_dir_entry_2 *de; 3585 int inlined; 3586 3587 /* entry for ".." in inode if it's a directory */ 3588 struct buffer_head *dir_bh; 3589 struct ext4_dir_entry_2 *parent_de; 3590 int dir_inlined; 3591 }; 3592 3593 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent, bool is_cross) 3594 { 3595 int retval; 3596 3597 ent->is_dir = true; 3598 if (!is_cross) 3599 return 0; 3600 3601 ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode, 3602 &retval, &ent->parent_de, 3603 &ent->dir_inlined); 3604 if (!ent->dir_bh) 3605 return retval; 3606 if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino) 3607 return -EFSCORRUPTED; 3608 BUFFER_TRACE(ent->dir_bh, "get_write_access"); 3609 return ext4_journal_get_write_access(handle, ent->dir->i_sb, 3610 ent->dir_bh, EXT4_JTR_NONE); 3611 } 3612 3613 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent, 3614 unsigned dir_ino) 3615 { 3616 int retval; 3617 3618 if (!ent->dir_bh) 3619 return 0; 3620 3621 ent->parent_de->inode = cpu_to_le32(dir_ino); 3622 BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata"); 3623 if (!ent->dir_inlined) { 3624 if (is_dx(ent->inode)) { 3625 retval = ext4_handle_dirty_dx_node(handle, 3626 ent->inode, 3627 ent->dir_bh); 3628 } else { 3629 retval = ext4_handle_dirty_dirblock(handle, ent->inode, 3630 ent->dir_bh); 3631 } 3632 } else { 3633 retval = ext4_mark_inode_dirty(handle, ent->inode); 3634 } 3635 if (retval) { 3636 ext4_std_error(ent->dir->i_sb, retval); 3637 return retval; 3638 } 3639 return 0; 3640 } 3641 3642 static int ext4_setent(handle_t *handle, struct ext4_renament *ent, 3643 unsigned ino, unsigned file_type) 3644 { 3645 int retval, retval2; 3646 3647 BUFFER_TRACE(ent->bh, "get write access"); 3648 retval = ext4_journal_get_write_access(handle, ent->dir->i_sb, ent->bh, 3649 EXT4_JTR_NONE); 3650 if (retval) 3651 return retval; 3652 ent->de->inode = cpu_to_le32(ino); 3653 if (ext4_has_feature_filetype(ent->dir->i_sb)) 3654 ent->de->file_type = file_type; 3655 inode_inc_iversion(ent->dir); 3656 inode_set_mtime_to_ts(ent->dir, inode_set_ctime_current(ent->dir)); 3657 retval = ext4_mark_inode_dirty(handle, ent->dir); 3658 BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata"); 3659 if (!ent->inlined) { 3660 retval2 = ext4_handle_dirty_dirblock(handle, ent->dir, ent->bh); 3661 if (unlikely(retval2)) { 3662 ext4_std_error(ent->dir->i_sb, retval2); 3663 return retval2; 3664 } 3665 } 3666 return retval; 3667 } 3668 3669 static void ext4_resetent(handle_t *handle, struct ext4_renament *ent, 3670 unsigned ino, unsigned file_type) 3671 { 3672 struct ext4_renament old = *ent; 3673 int retval = 0; 3674 3675 /* 3676 * old->de could have moved from under us during make indexed dir, 3677 * so the old->de may no longer valid and need to find it again 3678 * before reset old inode info. 3679 */ 3680 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, 3681 &old.inlined); 3682 if (IS_ERR(old.bh)) 3683 retval = PTR_ERR(old.bh); 3684 if (!old.bh) 3685 retval = -ENOENT; 3686 if (retval) { 3687 ext4_std_error(old.dir->i_sb, retval); 3688 return; 3689 } 3690 3691 ext4_setent(handle, &old, ino, file_type); 3692 brelse(old.bh); 3693 } 3694 3695 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir, 3696 const struct qstr *d_name) 3697 { 3698 int retval = -ENOENT; 3699 struct buffer_head *bh; 3700 struct ext4_dir_entry_2 *de; 3701 3702 bh = ext4_find_entry(dir, d_name, &de, NULL); 3703 if (IS_ERR(bh)) 3704 return PTR_ERR(bh); 3705 if (bh) { 3706 retval = ext4_delete_entry(handle, dir, de, bh); 3707 brelse(bh); 3708 } 3709 return retval; 3710 } 3711 3712 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent, 3713 int force_reread) 3714 { 3715 int retval; 3716 /* 3717 * ent->de could have moved from under us during htree split, so make 3718 * sure that we are deleting the right entry. We might also be pointing 3719 * to a stale entry in the unused part of ent->bh so just checking inum 3720 * and the name isn't enough. 3721 */ 3722 if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino || 3723 ent->de->name_len != ent->dentry->d_name.len || 3724 strncmp(ent->de->name, ent->dentry->d_name.name, 3725 ent->de->name_len) || 3726 force_reread) { 3727 retval = ext4_find_delete_entry(handle, ent->dir, 3728 &ent->dentry->d_name); 3729 } else { 3730 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh); 3731 if (retval == -ENOENT) { 3732 retval = ext4_find_delete_entry(handle, ent->dir, 3733 &ent->dentry->d_name); 3734 } 3735 } 3736 3737 if (retval) { 3738 ext4_warning_inode(ent->dir, 3739 "Deleting old file: nlink %d, error=%d", 3740 ent->dir->i_nlink, retval); 3741 } 3742 } 3743 3744 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent) 3745 { 3746 if (ent->dir_nlink_delta) { 3747 if (ent->dir_nlink_delta == -1) 3748 ext4_dec_count(ent->dir); 3749 else 3750 ext4_inc_count(ent->dir); 3751 ext4_mark_inode_dirty(handle, ent->dir); 3752 } 3753 } 3754 3755 static struct inode *ext4_whiteout_for_rename(struct mnt_idmap *idmap, 3756 struct ext4_renament *ent, 3757 int credits, handle_t **h) 3758 { 3759 struct inode *wh; 3760 handle_t *handle; 3761 int retries = 0; 3762 3763 /* 3764 * for inode block, sb block, group summaries, 3765 * and inode bitmap 3766 */ 3767 credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) + 3768 EXT4_XATTR_TRANS_BLOCKS + 4); 3769 retry: 3770 wh = ext4_new_inode_start_handle(idmap, ent->dir, 3771 S_IFCHR | WHITEOUT_MODE, 3772 &ent->dentry->d_name, 0, NULL, 3773 EXT4_HT_DIR, credits); 3774 3775 handle = ext4_journal_current_handle(); 3776 if (IS_ERR(wh)) { 3777 if (handle) 3778 ext4_journal_stop(handle); 3779 if (PTR_ERR(wh) == -ENOSPC && 3780 ext4_should_retry_alloc(ent->dir->i_sb, &retries)) 3781 goto retry; 3782 } else { 3783 *h = handle; 3784 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV); 3785 wh->i_op = &ext4_special_inode_operations; 3786 } 3787 return wh; 3788 } 3789 3790 /* 3791 * Anybody can rename anything with this: the permission checks are left to the 3792 * higher-level routines. 3793 * 3794 * n.b. old_{dentry,inode) refers to the source dentry/inode 3795 * while new_{dentry,inode) refers to the destination dentry/inode 3796 * This comes from rename(const char *oldpath, const char *newpath) 3797 */ 3798 static int ext4_rename(struct mnt_idmap *idmap, struct inode *old_dir, 3799 struct dentry *old_dentry, struct inode *new_dir, 3800 struct dentry *new_dentry, unsigned int flags) 3801 { 3802 handle_t *handle = NULL; 3803 struct ext4_renament old = { 3804 .dir = old_dir, 3805 .dentry = old_dentry, 3806 .inode = d_inode(old_dentry), 3807 }; 3808 struct ext4_renament new = { 3809 .dir = new_dir, 3810 .dentry = new_dentry, 3811 .inode = d_inode(new_dentry), 3812 }; 3813 int force_reread; 3814 int retval; 3815 struct inode *whiteout = NULL; 3816 int credits; 3817 u8 old_file_type; 3818 3819 if (new.inode && new.inode->i_nlink == 0) { 3820 EXT4_ERROR_INODE(new.inode, 3821 "target of rename is already freed"); 3822 return -EFSCORRUPTED; 3823 } 3824 3825 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) && 3826 (!projid_eq(EXT4_I(new_dir)->i_projid, 3827 EXT4_I(old_dentry->d_inode)->i_projid))) 3828 return -EXDEV; 3829 3830 retval = dquot_initialize(old.dir); 3831 if (retval) 3832 return retval; 3833 retval = dquot_initialize(old.inode); 3834 if (retval) 3835 return retval; 3836 retval = dquot_initialize(new.dir); 3837 if (retval) 3838 return retval; 3839 3840 /* Initialize quotas before so that eventual writes go 3841 * in separate transaction */ 3842 if (new.inode) { 3843 retval = dquot_initialize(new.inode); 3844 if (retval) 3845 return retval; 3846 } 3847 3848 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, 3849 &old.inlined); 3850 if (IS_ERR(old.bh)) 3851 return PTR_ERR(old.bh); 3852 3853 /* 3854 * Check for inode number is _not_ due to possible IO errors. 3855 * We might rmdir the source, keep it as pwd of some process 3856 * and merrily kill the link to whatever was created under the 3857 * same name. Goodbye sticky bit ;-< 3858 */ 3859 retval = -ENOENT; 3860 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino) 3861 goto release_bh; 3862 3863 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, 3864 &new.de, &new.inlined); 3865 if (IS_ERR(new.bh)) { 3866 retval = PTR_ERR(new.bh); 3867 new.bh = NULL; 3868 goto release_bh; 3869 } 3870 if (new.bh) { 3871 if (!new.inode) { 3872 brelse(new.bh); 3873 new.bh = NULL; 3874 } 3875 } 3876 if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC)) 3877 ext4_alloc_da_blocks(old.inode); 3878 3879 credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + 3880 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2); 3881 if (!(flags & RENAME_WHITEOUT)) { 3882 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits); 3883 if (IS_ERR(handle)) { 3884 retval = PTR_ERR(handle); 3885 goto release_bh; 3886 } 3887 } else { 3888 whiteout = ext4_whiteout_for_rename(idmap, &old, credits, &handle); 3889 if (IS_ERR(whiteout)) { 3890 retval = PTR_ERR(whiteout); 3891 goto release_bh; 3892 } 3893 } 3894 3895 old_file_type = old.de->file_type; 3896 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir)) 3897 ext4_handle_sync(handle); 3898 3899 if (S_ISDIR(old.inode->i_mode)) { 3900 if (new.inode) { 3901 retval = -ENOTEMPTY; 3902 if (!ext4_empty_dir(new.inode)) 3903 goto end_rename; 3904 } else { 3905 retval = -EMLINK; 3906 if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir)) 3907 goto end_rename; 3908 } 3909 retval = ext4_rename_dir_prepare(handle, &old, new.dir != old.dir); 3910 if (retval) 3911 goto end_rename; 3912 } 3913 /* 3914 * If we're renaming a file within an inline_data dir and adding or 3915 * setting the new dirent causes a conversion from inline_data to 3916 * extents/blockmap, we need to force the dirent delete code to 3917 * re-read the directory, or else we end up trying to delete a dirent 3918 * from what is now the extent tree root (or a block map). 3919 */ 3920 force_reread = (new.dir->i_ino == old.dir->i_ino && 3921 ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA)); 3922 3923 if (whiteout) { 3924 /* 3925 * Do this before adding a new entry, so the old entry is sure 3926 * to be still pointing to the valid old entry. 3927 */ 3928 retval = ext4_setent(handle, &old, whiteout->i_ino, 3929 EXT4_FT_CHRDEV); 3930 if (retval) 3931 goto end_rename; 3932 retval = ext4_mark_inode_dirty(handle, whiteout); 3933 if (unlikely(retval)) 3934 goto end_rename; 3935 3936 } 3937 if (!new.bh) { 3938 retval = ext4_add_entry(handle, new.dentry, old.inode); 3939 if (retval) 3940 goto end_rename; 3941 } else { 3942 retval = ext4_setent(handle, &new, 3943 old.inode->i_ino, old_file_type); 3944 if (retval) 3945 goto end_rename; 3946 } 3947 if (force_reread) 3948 force_reread = !ext4_test_inode_flag(new.dir, 3949 EXT4_INODE_INLINE_DATA); 3950 3951 /* 3952 * Like most other Unix systems, set the ctime for inodes on a 3953 * rename. 3954 */ 3955 inode_set_ctime_current(old.inode); 3956 retval = ext4_mark_inode_dirty(handle, old.inode); 3957 if (unlikely(retval)) 3958 goto end_rename; 3959 3960 if (!whiteout) { 3961 /* 3962 * ok, that's it 3963 */ 3964 ext4_rename_delete(handle, &old, force_reread); 3965 } 3966 3967 if (new.inode) { 3968 ext4_dec_count(new.inode); 3969 inode_set_ctime_current(new.inode); 3970 } 3971 inode_set_mtime_to_ts(old.dir, inode_set_ctime_current(old.dir)); 3972 ext4_update_dx_flag(old.dir); 3973 if (old.is_dir) { 3974 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); 3975 if (retval) 3976 goto end_rename; 3977 3978 ext4_dec_count(old.dir); 3979 if (new.inode) { 3980 /* checked ext4_empty_dir above, can't have another 3981 * parent, ext4_dec_count() won't work for many-linked 3982 * dirs */ 3983 clear_nlink(new.inode); 3984 } else { 3985 ext4_inc_count(new.dir); 3986 ext4_update_dx_flag(new.dir); 3987 retval = ext4_mark_inode_dirty(handle, new.dir); 3988 if (unlikely(retval)) 3989 goto end_rename; 3990 } 3991 } 3992 retval = ext4_mark_inode_dirty(handle, old.dir); 3993 if (unlikely(retval)) 3994 goto end_rename; 3995 3996 if (old.is_dir) { 3997 /* 3998 * We disable fast commits here that's because the 3999 * replay code is not yet capable of changing dot dot 4000 * dirents in directories. 4001 */ 4002 ext4_fc_mark_ineligible(old.inode->i_sb, 4003 EXT4_FC_REASON_RENAME_DIR, handle); 4004 } else { 4005 struct super_block *sb = old.inode->i_sb; 4006 4007 if (new.inode) 4008 ext4_fc_track_unlink(handle, new.dentry); 4009 if (test_opt2(sb, JOURNAL_FAST_COMMIT) && 4010 !(EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY) && 4011 !(ext4_test_mount_flag(sb, EXT4_MF_FC_INELIGIBLE))) { 4012 __ext4_fc_track_link(handle, old.inode, new.dentry); 4013 __ext4_fc_track_unlink(handle, old.inode, old.dentry); 4014 if (whiteout) 4015 __ext4_fc_track_create(handle, whiteout, 4016 old.dentry); 4017 } 4018 } 4019 4020 if (new.inode) { 4021 retval = ext4_mark_inode_dirty(handle, new.inode); 4022 if (unlikely(retval)) 4023 goto end_rename; 4024 if (!new.inode->i_nlink) 4025 ext4_orphan_add(handle, new.inode); 4026 } 4027 retval = 0; 4028 4029 end_rename: 4030 if (whiteout) { 4031 if (retval) { 4032 ext4_resetent(handle, &old, 4033 old.inode->i_ino, old_file_type); 4034 drop_nlink(whiteout); 4035 ext4_mark_inode_dirty(handle, whiteout); 4036 ext4_orphan_add(handle, whiteout); 4037 } 4038 unlock_new_inode(whiteout); 4039 ext4_journal_stop(handle); 4040 iput(whiteout); 4041 } else { 4042 ext4_journal_stop(handle); 4043 } 4044 release_bh: 4045 brelse(old.dir_bh); 4046 brelse(old.bh); 4047 brelse(new.bh); 4048 4049 return retval; 4050 } 4051 4052 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry, 4053 struct inode *new_dir, struct dentry *new_dentry) 4054 { 4055 handle_t *handle = NULL; 4056 struct ext4_renament old = { 4057 .dir = old_dir, 4058 .dentry = old_dentry, 4059 .inode = d_inode(old_dentry), 4060 }; 4061 struct ext4_renament new = { 4062 .dir = new_dir, 4063 .dentry = new_dentry, 4064 .inode = d_inode(new_dentry), 4065 }; 4066 u8 new_file_type; 4067 int retval; 4068 4069 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) && 4070 !projid_eq(EXT4_I(new_dir)->i_projid, 4071 EXT4_I(old_dentry->d_inode)->i_projid)) || 4072 (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) && 4073 !projid_eq(EXT4_I(old_dir)->i_projid, 4074 EXT4_I(new_dentry->d_inode)->i_projid))) 4075 return -EXDEV; 4076 4077 retval = dquot_initialize(old.dir); 4078 if (retval) 4079 return retval; 4080 retval = dquot_initialize(new.dir); 4081 if (retval) 4082 return retval; 4083 4084 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, 4085 &old.de, &old.inlined); 4086 if (IS_ERR(old.bh)) 4087 return PTR_ERR(old.bh); 4088 /* 4089 * Check for inode number is _not_ due to possible IO errors. 4090 * We might rmdir the source, keep it as pwd of some process 4091 * and merrily kill the link to whatever was created under the 4092 * same name. Goodbye sticky bit ;-< 4093 */ 4094 retval = -ENOENT; 4095 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino) 4096 goto end_rename; 4097 4098 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, 4099 &new.de, &new.inlined); 4100 if (IS_ERR(new.bh)) { 4101 retval = PTR_ERR(new.bh); 4102 new.bh = NULL; 4103 goto end_rename; 4104 } 4105 4106 /* RENAME_EXCHANGE case: old *and* new must both exist */ 4107 if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino) 4108 goto end_rename; 4109 4110 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, 4111 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + 4112 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2)); 4113 if (IS_ERR(handle)) { 4114 retval = PTR_ERR(handle); 4115 handle = NULL; 4116 goto end_rename; 4117 } 4118 4119 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir)) 4120 ext4_handle_sync(handle); 4121 4122 if (S_ISDIR(old.inode->i_mode)) { 4123 retval = ext4_rename_dir_prepare(handle, &old, new.dir != old.dir); 4124 if (retval) 4125 goto end_rename; 4126 } 4127 if (S_ISDIR(new.inode->i_mode)) { 4128 retval = ext4_rename_dir_prepare(handle, &new, new.dir != old.dir); 4129 if (retval) 4130 goto end_rename; 4131 } 4132 4133 /* 4134 * Other than the special case of overwriting a directory, parents' 4135 * nlink only needs to be modified if this is a cross directory rename. 4136 */ 4137 if (old.dir != new.dir && old.is_dir != new.is_dir) { 4138 old.dir_nlink_delta = old.is_dir ? -1 : 1; 4139 new.dir_nlink_delta = -old.dir_nlink_delta; 4140 retval = -EMLINK; 4141 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) || 4142 (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir))) 4143 goto end_rename; 4144 } 4145 4146 new_file_type = new.de->file_type; 4147 retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type); 4148 if (retval) 4149 goto end_rename; 4150 4151 retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type); 4152 if (retval) 4153 goto end_rename; 4154 4155 /* 4156 * Like most other Unix systems, set the ctime for inodes on a 4157 * rename. 4158 */ 4159 inode_set_ctime_current(old.inode); 4160 inode_set_ctime_current(new.inode); 4161 retval = ext4_mark_inode_dirty(handle, old.inode); 4162 if (unlikely(retval)) 4163 goto end_rename; 4164 retval = ext4_mark_inode_dirty(handle, new.inode); 4165 if (unlikely(retval)) 4166 goto end_rename; 4167 ext4_fc_mark_ineligible(new.inode->i_sb, 4168 EXT4_FC_REASON_CROSS_RENAME, handle); 4169 if (old.dir_bh) { 4170 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); 4171 if (retval) 4172 goto end_rename; 4173 } 4174 if (new.dir_bh) { 4175 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino); 4176 if (retval) 4177 goto end_rename; 4178 } 4179 ext4_update_dir_count(handle, &old); 4180 ext4_update_dir_count(handle, &new); 4181 retval = 0; 4182 4183 end_rename: 4184 brelse(old.dir_bh); 4185 brelse(new.dir_bh); 4186 brelse(old.bh); 4187 brelse(new.bh); 4188 if (handle) 4189 ext4_journal_stop(handle); 4190 return retval; 4191 } 4192 4193 static int ext4_rename2(struct mnt_idmap *idmap, 4194 struct inode *old_dir, struct dentry *old_dentry, 4195 struct inode *new_dir, struct dentry *new_dentry, 4196 unsigned int flags) 4197 { 4198 int err; 4199 4200 if (unlikely(ext4_forced_shutdown(old_dir->i_sb))) 4201 return -EIO; 4202 4203 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT)) 4204 return -EINVAL; 4205 4206 err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry, 4207 flags); 4208 if (err) 4209 return err; 4210 4211 if (flags & RENAME_EXCHANGE) { 4212 return ext4_cross_rename(old_dir, old_dentry, 4213 new_dir, new_dentry); 4214 } 4215 4216 return ext4_rename(idmap, old_dir, old_dentry, new_dir, new_dentry, flags); 4217 } 4218 4219 /* 4220 * directories can handle most operations... 4221 */ 4222 const struct inode_operations ext4_dir_inode_operations = { 4223 .create = ext4_create, 4224 .lookup = ext4_lookup, 4225 .link = ext4_link, 4226 .unlink = ext4_unlink, 4227 .symlink = ext4_symlink, 4228 .mkdir = ext4_mkdir, 4229 .rmdir = ext4_rmdir, 4230 .mknod = ext4_mknod, 4231 .tmpfile = ext4_tmpfile, 4232 .rename = ext4_rename2, 4233 .setattr = ext4_setattr, 4234 .getattr = ext4_getattr, 4235 .listxattr = ext4_listxattr, 4236 .get_inode_acl = ext4_get_acl, 4237 .set_acl = ext4_set_acl, 4238 .fiemap = ext4_fiemap, 4239 .fileattr_get = ext4_fileattr_get, 4240 .fileattr_set = ext4_fileattr_set, 4241 }; 4242 4243 const struct inode_operations ext4_special_inode_operations = { 4244 .setattr = ext4_setattr, 4245 .getattr = ext4_getattr, 4246 .listxattr = ext4_listxattr, 4247 .get_inode_acl = ext4_get_acl, 4248 .set_acl = ext4_set_acl, 4249 }; 4250