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 /* 1395 * Test whether a case-insensitive directory entry matches the filename 1396 * being searched for. If quick is set, assume the name being looked up 1397 * is already in the casefolded form. 1398 * 1399 * Returns: 0 if the directory entry matches, more than 0 if it 1400 * doesn't match or less than zero on error. 1401 */ 1402 static int ext4_ci_compare(const struct inode *parent, const struct qstr *name, 1403 u8 *de_name, size_t de_name_len, bool quick) 1404 { 1405 const struct super_block *sb = parent->i_sb; 1406 const struct unicode_map *um = sb->s_encoding; 1407 struct fscrypt_str decrypted_name = FSTR_INIT(NULL, de_name_len); 1408 struct qstr entry = QSTR_INIT(de_name, de_name_len); 1409 int ret; 1410 1411 if (IS_ENCRYPTED(parent)) { 1412 const struct fscrypt_str encrypted_name = 1413 FSTR_INIT(de_name, de_name_len); 1414 1415 decrypted_name.name = kmalloc(de_name_len, GFP_KERNEL); 1416 if (!decrypted_name.name) 1417 return -ENOMEM; 1418 ret = fscrypt_fname_disk_to_usr(parent, 0, 0, &encrypted_name, 1419 &decrypted_name); 1420 if (ret < 0) 1421 goto out; 1422 entry.name = decrypted_name.name; 1423 entry.len = decrypted_name.len; 1424 } 1425 1426 if (quick) 1427 ret = utf8_strncasecmp_folded(um, name, &entry); 1428 else 1429 ret = utf8_strncasecmp(um, name, &entry); 1430 if (ret < 0) { 1431 /* Handle invalid character sequence as either an error 1432 * or as an opaque byte sequence. 1433 */ 1434 if (sb_has_strict_encoding(sb)) 1435 ret = -EINVAL; 1436 else if (name->len != entry.len) 1437 ret = 1; 1438 else 1439 ret = !!memcmp(name->name, entry.name, entry.len); 1440 } 1441 out: 1442 kfree(decrypted_name.name); 1443 return ret; 1444 } 1445 1446 int ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname, 1447 struct ext4_filename *name) 1448 { 1449 struct fscrypt_str *cf_name = &name->cf_name; 1450 struct dx_hash_info *hinfo = &name->hinfo; 1451 int len; 1452 1453 if (!IS_CASEFOLDED(dir) || 1454 (IS_ENCRYPTED(dir) && !fscrypt_has_encryption_key(dir))) { 1455 cf_name->name = NULL; 1456 return 0; 1457 } 1458 1459 cf_name->name = kmalloc(EXT4_NAME_LEN, GFP_NOFS); 1460 if (!cf_name->name) 1461 return -ENOMEM; 1462 1463 len = utf8_casefold(dir->i_sb->s_encoding, 1464 iname, cf_name->name, 1465 EXT4_NAME_LEN); 1466 if (len <= 0) { 1467 kfree(cf_name->name); 1468 cf_name->name = NULL; 1469 } 1470 cf_name->len = (unsigned) len; 1471 if (!IS_ENCRYPTED(dir)) 1472 return 0; 1473 1474 hinfo->hash_version = DX_HASH_SIPHASH; 1475 hinfo->seed = NULL; 1476 if (cf_name->name) 1477 return ext4fs_dirhash(dir, cf_name->name, cf_name->len, hinfo); 1478 else 1479 return ext4fs_dirhash(dir, iname->name, iname->len, hinfo); 1480 } 1481 #endif 1482 1483 /* 1484 * Test whether a directory entry matches the filename being searched for. 1485 * 1486 * Return: %true if the directory entry matches, otherwise %false. 1487 */ 1488 static bool ext4_match(struct inode *parent, 1489 const struct ext4_filename *fname, 1490 struct ext4_dir_entry_2 *de) 1491 { 1492 struct fscrypt_name f; 1493 1494 if (!de->inode) 1495 return false; 1496 1497 f.usr_fname = fname->usr_fname; 1498 f.disk_name = fname->disk_name; 1499 #ifdef CONFIG_FS_ENCRYPTION 1500 f.crypto_buf = fname->crypto_buf; 1501 #endif 1502 1503 #if IS_ENABLED(CONFIG_UNICODE) 1504 if (IS_CASEFOLDED(parent) && 1505 (!IS_ENCRYPTED(parent) || fscrypt_has_encryption_key(parent))) { 1506 if (fname->cf_name.name) { 1507 struct qstr cf = {.name = fname->cf_name.name, 1508 .len = fname->cf_name.len}; 1509 if (IS_ENCRYPTED(parent)) { 1510 if (fname->hinfo.hash != EXT4_DIRENT_HASH(de) || 1511 fname->hinfo.minor_hash != 1512 EXT4_DIRENT_MINOR_HASH(de)) { 1513 1514 return false; 1515 } 1516 } 1517 return !ext4_ci_compare(parent, &cf, de->name, 1518 de->name_len, true); 1519 } 1520 return !ext4_ci_compare(parent, fname->usr_fname, de->name, 1521 de->name_len, false); 1522 } 1523 #endif 1524 1525 return fscrypt_match_name(&f, de->name, de->name_len); 1526 } 1527 1528 /* 1529 * Returns 0 if not found, -1 on failure, and 1 on success 1530 */ 1531 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size, 1532 struct inode *dir, struct ext4_filename *fname, 1533 unsigned int offset, struct ext4_dir_entry_2 **res_dir) 1534 { 1535 struct ext4_dir_entry_2 * de; 1536 char * dlimit; 1537 int de_len; 1538 1539 de = (struct ext4_dir_entry_2 *)search_buf; 1540 dlimit = search_buf + buf_size; 1541 while ((char *) de < dlimit - EXT4_BASE_DIR_LEN) { 1542 /* this code is executed quadratically often */ 1543 /* do minimal checking `by hand' */ 1544 if (de->name + de->name_len <= dlimit && 1545 ext4_match(dir, fname, de)) { 1546 /* found a match - just to be sure, do 1547 * a full check */ 1548 if (ext4_check_dir_entry(dir, NULL, de, bh, search_buf, 1549 buf_size, offset)) 1550 return -1; 1551 *res_dir = de; 1552 return 1; 1553 } 1554 /* prevent looping on a bad block */ 1555 de_len = ext4_rec_len_from_disk(de->rec_len, 1556 dir->i_sb->s_blocksize); 1557 if (de_len <= 0) 1558 return -1; 1559 offset += de_len; 1560 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len); 1561 } 1562 return 0; 1563 } 1564 1565 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block, 1566 struct ext4_dir_entry *de) 1567 { 1568 struct super_block *sb = dir->i_sb; 1569 1570 if (!is_dx(dir)) 1571 return 0; 1572 if (block == 0) 1573 return 1; 1574 if (de->inode == 0 && 1575 ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) == 1576 sb->s_blocksize) 1577 return 1; 1578 return 0; 1579 } 1580 1581 /* 1582 * __ext4_find_entry() 1583 * 1584 * finds an entry in the specified directory with the wanted name. It 1585 * returns the cache buffer in which the entry was found, and the entry 1586 * itself (as a parameter - res_dir). It does NOT read the inode of the 1587 * entry - you'll have to do that yourself if you want to. 1588 * 1589 * The returned buffer_head has ->b_count elevated. The caller is expected 1590 * to brelse() it when appropriate. 1591 */ 1592 static struct buffer_head *__ext4_find_entry(struct inode *dir, 1593 struct ext4_filename *fname, 1594 struct ext4_dir_entry_2 **res_dir, 1595 int *inlined) 1596 { 1597 struct super_block *sb; 1598 struct buffer_head *bh_use[NAMEI_RA_SIZE]; 1599 struct buffer_head *bh, *ret = NULL; 1600 ext4_lblk_t start, block; 1601 const u8 *name = fname->usr_fname->name; 1602 size_t ra_max = 0; /* Number of bh's in the readahead 1603 buffer, bh_use[] */ 1604 size_t ra_ptr = 0; /* Current index into readahead 1605 buffer */ 1606 ext4_lblk_t nblocks; 1607 int i, namelen, retval; 1608 1609 *res_dir = NULL; 1610 sb = dir->i_sb; 1611 namelen = fname->usr_fname->len; 1612 if (namelen > EXT4_NAME_LEN) 1613 return NULL; 1614 1615 if (ext4_has_inline_data(dir)) { 1616 int has_inline_data = 1; 1617 ret = ext4_find_inline_entry(dir, fname, res_dir, 1618 &has_inline_data); 1619 if (inlined) 1620 *inlined = has_inline_data; 1621 if (has_inline_data) 1622 goto cleanup_and_exit; 1623 } 1624 1625 if ((namelen <= 2) && (name[0] == '.') && 1626 (name[1] == '.' || name[1] == '\0')) { 1627 /* 1628 * "." or ".." will only be in the first block 1629 * NFS may look up ".."; "." should be handled by the VFS 1630 */ 1631 block = start = 0; 1632 nblocks = 1; 1633 goto restart; 1634 } 1635 if (is_dx(dir)) { 1636 ret = ext4_dx_find_entry(dir, fname, res_dir); 1637 /* 1638 * On success, or if the error was file not found, 1639 * return. Otherwise, fall back to doing a search the 1640 * old fashioned way. 1641 */ 1642 if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR) 1643 goto cleanup_and_exit; 1644 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, " 1645 "falling back\n")); 1646 ret = NULL; 1647 } 1648 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); 1649 if (!nblocks) { 1650 ret = NULL; 1651 goto cleanup_and_exit; 1652 } 1653 start = EXT4_I(dir)->i_dir_start_lookup; 1654 if (start >= nblocks) 1655 start = 0; 1656 block = start; 1657 restart: 1658 do { 1659 /* 1660 * We deal with the read-ahead logic here. 1661 */ 1662 cond_resched(); 1663 if (ra_ptr >= ra_max) { 1664 /* Refill the readahead buffer */ 1665 ra_ptr = 0; 1666 if (block < start) 1667 ra_max = start - block; 1668 else 1669 ra_max = nblocks - block; 1670 ra_max = min(ra_max, ARRAY_SIZE(bh_use)); 1671 retval = ext4_bread_batch(dir, block, ra_max, 1672 false /* wait */, bh_use); 1673 if (retval) { 1674 ret = ERR_PTR(retval); 1675 ra_max = 0; 1676 goto cleanup_and_exit; 1677 } 1678 } 1679 if ((bh = bh_use[ra_ptr++]) == NULL) 1680 goto next; 1681 wait_on_buffer(bh); 1682 if (!buffer_uptodate(bh)) { 1683 EXT4_ERROR_INODE_ERR(dir, EIO, 1684 "reading directory lblock %lu", 1685 (unsigned long) block); 1686 brelse(bh); 1687 ret = ERR_PTR(-EIO); 1688 goto cleanup_and_exit; 1689 } 1690 if (!buffer_verified(bh) && 1691 !is_dx_internal_node(dir, block, 1692 (struct ext4_dir_entry *)bh->b_data) && 1693 !ext4_dirblock_csum_verify(dir, bh)) { 1694 EXT4_ERROR_INODE_ERR(dir, EFSBADCRC, 1695 "checksumming directory " 1696 "block %lu", (unsigned long)block); 1697 brelse(bh); 1698 ret = ERR_PTR(-EFSBADCRC); 1699 goto cleanup_and_exit; 1700 } 1701 set_buffer_verified(bh); 1702 i = search_dirblock(bh, dir, fname, 1703 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir); 1704 if (i == 1) { 1705 EXT4_I(dir)->i_dir_start_lookup = block; 1706 ret = bh; 1707 goto cleanup_and_exit; 1708 } else { 1709 brelse(bh); 1710 if (i < 0) 1711 goto cleanup_and_exit; 1712 } 1713 next: 1714 if (++block >= nblocks) 1715 block = 0; 1716 } while (block != start); 1717 1718 /* 1719 * If the directory has grown while we were searching, then 1720 * search the last part of the directory before giving up. 1721 */ 1722 block = nblocks; 1723 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); 1724 if (block < nblocks) { 1725 start = 0; 1726 goto restart; 1727 } 1728 1729 cleanup_and_exit: 1730 /* Clean up the read-ahead blocks */ 1731 for (; ra_ptr < ra_max; ra_ptr++) 1732 brelse(bh_use[ra_ptr]); 1733 return ret; 1734 } 1735 1736 static struct buffer_head *ext4_find_entry(struct inode *dir, 1737 const struct qstr *d_name, 1738 struct ext4_dir_entry_2 **res_dir, 1739 int *inlined) 1740 { 1741 int err; 1742 struct ext4_filename fname; 1743 struct buffer_head *bh; 1744 1745 err = ext4_fname_setup_filename(dir, d_name, 1, &fname); 1746 if (err == -ENOENT) 1747 return NULL; 1748 if (err) 1749 return ERR_PTR(err); 1750 1751 bh = __ext4_find_entry(dir, &fname, res_dir, inlined); 1752 1753 ext4_fname_free_filename(&fname); 1754 return bh; 1755 } 1756 1757 static struct buffer_head *ext4_lookup_entry(struct inode *dir, 1758 struct dentry *dentry, 1759 struct ext4_dir_entry_2 **res_dir) 1760 { 1761 int err; 1762 struct ext4_filename fname; 1763 struct buffer_head *bh; 1764 1765 err = ext4_fname_prepare_lookup(dir, dentry, &fname); 1766 generic_set_encrypted_ci_d_ops(dentry); 1767 if (err == -ENOENT) 1768 return NULL; 1769 if (err) 1770 return ERR_PTR(err); 1771 1772 bh = __ext4_find_entry(dir, &fname, res_dir, NULL); 1773 1774 ext4_fname_free_filename(&fname); 1775 return bh; 1776 } 1777 1778 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, 1779 struct ext4_filename *fname, 1780 struct ext4_dir_entry_2 **res_dir) 1781 { 1782 struct super_block * sb = dir->i_sb; 1783 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 1784 struct buffer_head *bh; 1785 ext4_lblk_t block; 1786 int retval; 1787 1788 #ifdef CONFIG_FS_ENCRYPTION 1789 *res_dir = NULL; 1790 #endif 1791 frame = dx_probe(fname, dir, NULL, frames); 1792 if (IS_ERR(frame)) 1793 return (struct buffer_head *) frame; 1794 do { 1795 block = dx_get_block(frame->at); 1796 bh = ext4_read_dirblock(dir, block, DIRENT_HTREE); 1797 if (IS_ERR(bh)) 1798 goto errout; 1799 1800 retval = search_dirblock(bh, dir, fname, 1801 block << EXT4_BLOCK_SIZE_BITS(sb), 1802 res_dir); 1803 if (retval == 1) 1804 goto success; 1805 brelse(bh); 1806 if (retval == -1) { 1807 bh = ERR_PTR(ERR_BAD_DX_DIR); 1808 goto errout; 1809 } 1810 1811 /* Check to see if we should continue to search */ 1812 retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame, 1813 frames, NULL); 1814 if (retval < 0) { 1815 ext4_warning_inode(dir, 1816 "error %d reading directory index block", 1817 retval); 1818 bh = ERR_PTR(retval); 1819 goto errout; 1820 } 1821 } while (retval == 1); 1822 1823 bh = NULL; 1824 errout: 1825 dxtrace(printk(KERN_DEBUG "%s not found\n", fname->usr_fname->name)); 1826 success: 1827 dx_release(frames); 1828 return bh; 1829 } 1830 1831 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 1832 { 1833 struct inode *inode; 1834 struct ext4_dir_entry_2 *de; 1835 struct buffer_head *bh; 1836 1837 if (dentry->d_name.len > EXT4_NAME_LEN) 1838 return ERR_PTR(-ENAMETOOLONG); 1839 1840 bh = ext4_lookup_entry(dir, dentry, &de); 1841 if (IS_ERR(bh)) 1842 return ERR_CAST(bh); 1843 inode = NULL; 1844 if (bh) { 1845 __u32 ino = le32_to_cpu(de->inode); 1846 brelse(bh); 1847 if (!ext4_valid_inum(dir->i_sb, ino)) { 1848 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino); 1849 return ERR_PTR(-EFSCORRUPTED); 1850 } 1851 if (unlikely(ino == dir->i_ino)) { 1852 EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir", 1853 dentry); 1854 return ERR_PTR(-EFSCORRUPTED); 1855 } 1856 inode = ext4_iget(dir->i_sb, ino, EXT4_IGET_NORMAL); 1857 if (inode == ERR_PTR(-ESTALE)) { 1858 EXT4_ERROR_INODE(dir, 1859 "deleted inode referenced: %u", 1860 ino); 1861 return ERR_PTR(-EFSCORRUPTED); 1862 } 1863 if (!IS_ERR(inode) && IS_ENCRYPTED(dir) && 1864 (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) && 1865 !fscrypt_has_permitted_context(dir, inode)) { 1866 ext4_warning(inode->i_sb, 1867 "Inconsistent encryption contexts: %lu/%lu", 1868 dir->i_ino, inode->i_ino); 1869 iput(inode); 1870 return ERR_PTR(-EPERM); 1871 } 1872 } 1873 1874 #if IS_ENABLED(CONFIG_UNICODE) 1875 if (!inode && IS_CASEFOLDED(dir)) { 1876 /* Eventually we want to call d_add_ci(dentry, NULL) 1877 * for negative dentries in the encoding case as 1878 * well. For now, prevent the negative dentry 1879 * from being cached. 1880 */ 1881 return NULL; 1882 } 1883 #endif 1884 return d_splice_alias(inode, dentry); 1885 } 1886 1887 1888 struct dentry *ext4_get_parent(struct dentry *child) 1889 { 1890 __u32 ino; 1891 struct ext4_dir_entry_2 * de; 1892 struct buffer_head *bh; 1893 1894 bh = ext4_find_entry(d_inode(child), &dotdot_name, &de, NULL); 1895 if (IS_ERR(bh)) 1896 return ERR_CAST(bh); 1897 if (!bh) 1898 return ERR_PTR(-ENOENT); 1899 ino = le32_to_cpu(de->inode); 1900 brelse(bh); 1901 1902 if (!ext4_valid_inum(child->d_sb, ino)) { 1903 EXT4_ERROR_INODE(d_inode(child), 1904 "bad parent inode number: %u", ino); 1905 return ERR_PTR(-EFSCORRUPTED); 1906 } 1907 1908 return d_obtain_alias(ext4_iget(child->d_sb, ino, EXT4_IGET_NORMAL)); 1909 } 1910 1911 /* 1912 * Move count entries from end of map between two memory locations. 1913 * Returns pointer to last entry moved. 1914 */ 1915 static struct ext4_dir_entry_2 * 1916 dx_move_dirents(struct inode *dir, char *from, char *to, 1917 struct dx_map_entry *map, int count, 1918 unsigned blocksize) 1919 { 1920 unsigned rec_len = 0; 1921 1922 while (count--) { 1923 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) 1924 (from + (map->offs<<2)); 1925 rec_len = ext4_dir_rec_len(de->name_len, dir); 1926 1927 memcpy (to, de, rec_len); 1928 ((struct ext4_dir_entry_2 *) to)->rec_len = 1929 ext4_rec_len_to_disk(rec_len, blocksize); 1930 1931 /* wipe dir_entry excluding the rec_len field */ 1932 de->inode = 0; 1933 memset(&de->name_len, 0, ext4_rec_len_from_disk(de->rec_len, 1934 blocksize) - 1935 offsetof(struct ext4_dir_entry_2, 1936 name_len)); 1937 1938 map++; 1939 to += rec_len; 1940 } 1941 return (struct ext4_dir_entry_2 *) (to - rec_len); 1942 } 1943 1944 /* 1945 * Compact each dir entry in the range to the minimal rec_len. 1946 * Returns pointer to last entry in range. 1947 */ 1948 static struct ext4_dir_entry_2 *dx_pack_dirents(struct inode *dir, char *base, 1949 unsigned int blocksize) 1950 { 1951 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base; 1952 unsigned rec_len = 0; 1953 1954 prev = to = de; 1955 while ((char*)de < base + blocksize) { 1956 next = ext4_next_entry(de, blocksize); 1957 if (de->inode && de->name_len) { 1958 rec_len = ext4_dir_rec_len(de->name_len, dir); 1959 if (de > to) 1960 memmove(to, de, rec_len); 1961 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize); 1962 prev = to; 1963 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len); 1964 } 1965 de = next; 1966 } 1967 return prev; 1968 } 1969 1970 /* 1971 * Split a full leaf block to make room for a new dir entry. 1972 * Allocate a new block, and move entries so that they are approx. equally full. 1973 * Returns pointer to de in block into which the new entry will be inserted. 1974 */ 1975 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir, 1976 struct buffer_head **bh,struct dx_frame *frame, 1977 struct dx_hash_info *hinfo) 1978 { 1979 unsigned blocksize = dir->i_sb->s_blocksize; 1980 unsigned continued; 1981 int count; 1982 struct buffer_head *bh2; 1983 ext4_lblk_t newblock; 1984 u32 hash2; 1985 struct dx_map_entry *map; 1986 char *data1 = (*bh)->b_data, *data2; 1987 unsigned split, move, size; 1988 struct ext4_dir_entry_2 *de = NULL, *de2; 1989 int csum_size = 0; 1990 int err = 0, i; 1991 1992 if (ext4_has_metadata_csum(dir->i_sb)) 1993 csum_size = sizeof(struct ext4_dir_entry_tail); 1994 1995 bh2 = ext4_append(handle, dir, &newblock); 1996 if (IS_ERR(bh2)) { 1997 brelse(*bh); 1998 *bh = NULL; 1999 return (struct ext4_dir_entry_2 *) bh2; 2000 } 2001 2002 BUFFER_TRACE(*bh, "get_write_access"); 2003 err = ext4_journal_get_write_access(handle, dir->i_sb, *bh, 2004 EXT4_JTR_NONE); 2005 if (err) 2006 goto journal_error; 2007 2008 BUFFER_TRACE(frame->bh, "get_write_access"); 2009 err = ext4_journal_get_write_access(handle, dir->i_sb, frame->bh, 2010 EXT4_JTR_NONE); 2011 if (err) 2012 goto journal_error; 2013 2014 data2 = bh2->b_data; 2015 2016 /* create map in the end of data2 block */ 2017 map = (struct dx_map_entry *) (data2 + blocksize); 2018 count = dx_make_map(dir, *bh, hinfo, map); 2019 if (count < 0) { 2020 err = count; 2021 goto journal_error; 2022 } 2023 map -= count; 2024 dx_sort_map(map, count); 2025 /* Ensure that neither split block is over half full */ 2026 size = 0; 2027 move = 0; 2028 for (i = count-1; i >= 0; i--) { 2029 /* is more than half of this entry in 2nd half of the block? */ 2030 if (size + map[i].size/2 > blocksize/2) 2031 break; 2032 size += map[i].size; 2033 move++; 2034 } 2035 /* 2036 * map index at which we will split 2037 * 2038 * If the sum of active entries didn't exceed half the block size, just 2039 * split it in half by count; each resulting block will have at least 2040 * half the space free. 2041 */ 2042 if (i > 0) 2043 split = count - move; 2044 else 2045 split = count/2; 2046 2047 hash2 = map[split].hash; 2048 continued = hash2 == map[split - 1].hash; 2049 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n", 2050 (unsigned long)dx_get_block(frame->at), 2051 hash2, split, count-split)); 2052 2053 /* Fancy dance to stay within two buffers */ 2054 de2 = dx_move_dirents(dir, data1, data2, map + split, count - split, 2055 blocksize); 2056 de = dx_pack_dirents(dir, data1, blocksize); 2057 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) - 2058 (char *) de, 2059 blocksize); 2060 de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) - 2061 (char *) de2, 2062 blocksize); 2063 if (csum_size) { 2064 ext4_initialize_dirent_tail(*bh, blocksize); 2065 ext4_initialize_dirent_tail(bh2, blocksize); 2066 } 2067 2068 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1, 2069 blocksize, 1)); 2070 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2, 2071 blocksize, 1)); 2072 2073 /* Which block gets the new entry? */ 2074 if (hinfo->hash >= hash2) { 2075 swap(*bh, bh2); 2076 de = de2; 2077 } 2078 dx_insert_block(frame, hash2 + continued, newblock); 2079 err = ext4_handle_dirty_dirblock(handle, dir, bh2); 2080 if (err) 2081 goto journal_error; 2082 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 2083 if (err) 2084 goto journal_error; 2085 brelse(bh2); 2086 dxtrace(dx_show_index("frame", frame->entries)); 2087 return de; 2088 2089 journal_error: 2090 brelse(*bh); 2091 brelse(bh2); 2092 *bh = NULL; 2093 ext4_std_error(dir->i_sb, err); 2094 return ERR_PTR(err); 2095 } 2096 2097 int ext4_find_dest_de(struct inode *dir, struct inode *inode, 2098 struct buffer_head *bh, 2099 void *buf, int buf_size, 2100 struct ext4_filename *fname, 2101 struct ext4_dir_entry_2 **dest_de) 2102 { 2103 struct ext4_dir_entry_2 *de; 2104 unsigned short reclen = ext4_dir_rec_len(fname_len(fname), dir); 2105 int nlen, rlen; 2106 unsigned int offset = 0; 2107 char *top; 2108 2109 de = buf; 2110 top = buf + buf_size - reclen; 2111 while ((char *) de <= top) { 2112 if (ext4_check_dir_entry(dir, NULL, de, bh, 2113 buf, buf_size, offset)) 2114 return -EFSCORRUPTED; 2115 if (ext4_match(dir, fname, de)) 2116 return -EEXIST; 2117 nlen = ext4_dir_rec_len(de->name_len, dir); 2118 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 2119 if ((de->inode ? rlen - nlen : rlen) >= reclen) 2120 break; 2121 de = (struct ext4_dir_entry_2 *)((char *)de + rlen); 2122 offset += rlen; 2123 } 2124 if ((char *) de > top) 2125 return -ENOSPC; 2126 2127 *dest_de = de; 2128 return 0; 2129 } 2130 2131 void ext4_insert_dentry(struct inode *dir, 2132 struct inode *inode, 2133 struct ext4_dir_entry_2 *de, 2134 int buf_size, 2135 struct ext4_filename *fname) 2136 { 2137 2138 int nlen, rlen; 2139 2140 nlen = ext4_dir_rec_len(de->name_len, dir); 2141 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 2142 if (de->inode) { 2143 struct ext4_dir_entry_2 *de1 = 2144 (struct ext4_dir_entry_2 *)((char *)de + nlen); 2145 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size); 2146 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size); 2147 de = de1; 2148 } 2149 de->file_type = EXT4_FT_UNKNOWN; 2150 de->inode = cpu_to_le32(inode->i_ino); 2151 ext4_set_de_type(inode->i_sb, de, inode->i_mode); 2152 de->name_len = fname_len(fname); 2153 memcpy(de->name, fname_name(fname), fname_len(fname)); 2154 if (ext4_hash_in_dirent(dir)) { 2155 struct dx_hash_info *hinfo = &fname->hinfo; 2156 2157 EXT4_DIRENT_HASHES(de)->hash = cpu_to_le32(hinfo->hash); 2158 EXT4_DIRENT_HASHES(de)->minor_hash = 2159 cpu_to_le32(hinfo->minor_hash); 2160 } 2161 } 2162 2163 /* 2164 * Add a new entry into a directory (leaf) block. If de is non-NULL, 2165 * it points to a directory entry which is guaranteed to be large 2166 * enough for new directory entry. If de is NULL, then 2167 * add_dirent_to_buf will attempt search the directory block for 2168 * space. It will return -ENOSPC if no space is available, and -EIO 2169 * and -EEXIST if directory entry already exists. 2170 */ 2171 static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname, 2172 struct inode *dir, 2173 struct inode *inode, struct ext4_dir_entry_2 *de, 2174 struct buffer_head *bh) 2175 { 2176 unsigned int blocksize = dir->i_sb->s_blocksize; 2177 int csum_size = 0; 2178 int err, err2; 2179 2180 if (ext4_has_metadata_csum(inode->i_sb)) 2181 csum_size = sizeof(struct ext4_dir_entry_tail); 2182 2183 if (!de) { 2184 err = ext4_find_dest_de(dir, inode, bh, bh->b_data, 2185 blocksize - csum_size, fname, &de); 2186 if (err) 2187 return err; 2188 } 2189 BUFFER_TRACE(bh, "get_write_access"); 2190 err = ext4_journal_get_write_access(handle, dir->i_sb, bh, 2191 EXT4_JTR_NONE); 2192 if (err) { 2193 ext4_std_error(dir->i_sb, err); 2194 return err; 2195 } 2196 2197 /* By now the buffer is marked for journaling */ 2198 ext4_insert_dentry(dir, inode, de, blocksize, fname); 2199 2200 /* 2201 * XXX shouldn't update any times until successful 2202 * completion of syscall, but too many callers depend 2203 * on this. 2204 * 2205 * XXX similarly, too many callers depend on 2206 * ext4_new_inode() setting the times, but error 2207 * recovery deletes the inode, so the worst that can 2208 * happen is that the times are slightly out of date 2209 * and/or different from the directory change time. 2210 */ 2211 dir->i_mtime = inode_set_ctime_current(dir); 2212 ext4_update_dx_flag(dir); 2213 inode_inc_iversion(dir); 2214 err2 = ext4_mark_inode_dirty(handle, dir); 2215 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); 2216 err = ext4_handle_dirty_dirblock(handle, dir, bh); 2217 if (err) 2218 ext4_std_error(dir->i_sb, err); 2219 return err ? err : err2; 2220 } 2221 2222 static bool ext4_check_dx_root(struct inode *dir, struct dx_root *root) 2223 { 2224 struct fake_dirent *fde; 2225 const char *error_msg; 2226 unsigned int rlen; 2227 unsigned int blocksize = dir->i_sb->s_blocksize; 2228 char *blockend = (char *)root + dir->i_sb->s_blocksize; 2229 2230 fde = &root->dot; 2231 if (unlikely(fde->name_len != 1)) { 2232 error_msg = "invalid name_len for '.'"; 2233 goto corrupted; 2234 } 2235 if (unlikely(strncmp(root->dot_name, ".", fde->name_len))) { 2236 error_msg = "invalid name for '.'"; 2237 goto corrupted; 2238 } 2239 rlen = ext4_rec_len_from_disk(fde->rec_len, blocksize); 2240 if (unlikely((char *)fde + rlen >= blockend)) { 2241 error_msg = "invalid rec_len for '.'"; 2242 goto corrupted; 2243 } 2244 2245 fde = &root->dotdot; 2246 if (unlikely(fde->name_len != 2)) { 2247 error_msg = "invalid name_len for '..'"; 2248 goto corrupted; 2249 } 2250 if (unlikely(strncmp(root->dotdot_name, "..", fde->name_len))) { 2251 error_msg = "invalid name for '..'"; 2252 goto corrupted; 2253 } 2254 rlen = ext4_rec_len_from_disk(fde->rec_len, blocksize); 2255 if (unlikely((char *)fde + rlen >= blockend)) { 2256 error_msg = "invalid rec_len for '..'"; 2257 goto corrupted; 2258 } 2259 2260 return true; 2261 2262 corrupted: 2263 EXT4_ERROR_INODE(dir, "Corrupt dir, %s, running e2fsck is recommended", 2264 error_msg); 2265 return false; 2266 } 2267 2268 /* 2269 * This converts a one block unindexed directory to a 3 block indexed 2270 * directory, and adds the dentry to the indexed directory. 2271 */ 2272 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname, 2273 struct inode *dir, 2274 struct inode *inode, struct buffer_head *bh) 2275 { 2276 struct buffer_head *bh2; 2277 struct dx_root *root; 2278 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 2279 struct dx_entry *entries; 2280 struct ext4_dir_entry_2 *de, *de2; 2281 char *data2, *top; 2282 unsigned len; 2283 int retval; 2284 unsigned blocksize; 2285 ext4_lblk_t block; 2286 struct fake_dirent *fde; 2287 int csum_size = 0; 2288 2289 if (ext4_has_metadata_csum(inode->i_sb)) 2290 csum_size = sizeof(struct ext4_dir_entry_tail); 2291 2292 blocksize = dir->i_sb->s_blocksize; 2293 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino)); 2294 BUFFER_TRACE(bh, "get_write_access"); 2295 retval = ext4_journal_get_write_access(handle, dir->i_sb, bh, 2296 EXT4_JTR_NONE); 2297 if (retval) { 2298 ext4_std_error(dir->i_sb, retval); 2299 brelse(bh); 2300 return retval; 2301 } 2302 2303 root = (struct dx_root *) bh->b_data; 2304 if (!ext4_check_dx_root(dir, root)) { 2305 brelse(bh); 2306 return -EFSCORRUPTED; 2307 } 2308 2309 /* The 0th block becomes the root, move the dirents out */ 2310 fde = &root->dotdot; 2311 de = (struct ext4_dir_entry_2 *)((char *)fde + 2312 ext4_rec_len_from_disk(fde->rec_len, blocksize)); 2313 len = ((char *) root) + (blocksize - csum_size) - (char *) de; 2314 2315 /* Allocate new block for the 0th block's dirents */ 2316 bh2 = ext4_append(handle, dir, &block); 2317 if (IS_ERR(bh2)) { 2318 brelse(bh); 2319 return PTR_ERR(bh2); 2320 } 2321 ext4_set_inode_flag(dir, EXT4_INODE_INDEX); 2322 data2 = bh2->b_data; 2323 2324 memcpy(data2, de, len); 2325 memset(de, 0, len); /* wipe old data */ 2326 de = (struct ext4_dir_entry_2 *) data2; 2327 top = data2 + len; 2328 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top) { 2329 if (ext4_check_dir_entry(dir, NULL, de, bh2, data2, len, 2330 (data2 + (blocksize - csum_size) - 2331 (char *) de))) { 2332 brelse(bh2); 2333 brelse(bh); 2334 return -EFSCORRUPTED; 2335 } 2336 de = de2; 2337 } 2338 de->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) - 2339 (char *) de, blocksize); 2340 2341 if (csum_size) 2342 ext4_initialize_dirent_tail(bh2, blocksize); 2343 2344 /* Initialize the root; the dot dirents already exist */ 2345 de = (struct ext4_dir_entry_2 *) (&root->dotdot); 2346 de->rec_len = ext4_rec_len_to_disk( 2347 blocksize - ext4_dir_rec_len(2, NULL), blocksize); 2348 memset (&root->info, 0, sizeof(root->info)); 2349 root->info.info_length = sizeof(root->info); 2350 if (ext4_hash_in_dirent(dir)) 2351 root->info.hash_version = DX_HASH_SIPHASH; 2352 else 2353 root->info.hash_version = 2354 EXT4_SB(dir->i_sb)->s_def_hash_version; 2355 2356 entries = root->entries; 2357 dx_set_block(entries, 1); 2358 dx_set_count(entries, 1); 2359 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info))); 2360 2361 /* Initialize as for dx_probe */ 2362 fname->hinfo.hash_version = root->info.hash_version; 2363 if (fname->hinfo.hash_version <= DX_HASH_TEA) 2364 fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; 2365 fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; 2366 2367 /* casefolded encrypted hashes are computed on fname setup */ 2368 if (!ext4_hash_in_dirent(dir)) { 2369 int err = ext4fs_dirhash(dir, fname_name(fname), 2370 fname_len(fname), &fname->hinfo); 2371 if (err < 0) { 2372 brelse(bh2); 2373 brelse(bh); 2374 return err; 2375 } 2376 } 2377 memset(frames, 0, sizeof(frames)); 2378 frame = frames; 2379 frame->entries = entries; 2380 frame->at = entries; 2381 frame->bh = bh; 2382 2383 retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 2384 if (retval) 2385 goto out_frames; 2386 retval = ext4_handle_dirty_dirblock(handle, dir, bh2); 2387 if (retval) 2388 goto out_frames; 2389 2390 de = do_split(handle,dir, &bh2, frame, &fname->hinfo); 2391 if (IS_ERR(de)) { 2392 retval = PTR_ERR(de); 2393 goto out_frames; 2394 } 2395 2396 retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2); 2397 out_frames: 2398 /* 2399 * Even if the block split failed, we have to properly write 2400 * out all the changes we did so far. Otherwise we can end up 2401 * with corrupted filesystem. 2402 */ 2403 if (retval) 2404 ext4_mark_inode_dirty(handle, dir); 2405 dx_release(frames); 2406 brelse(bh2); 2407 return retval; 2408 } 2409 2410 /* 2411 * ext4_add_entry() 2412 * 2413 * adds a file entry to the specified directory, using the same 2414 * semantics as ext4_find_entry(). It returns NULL if it failed. 2415 * 2416 * NOTE!! The inode part of 'de' is left at 0 - which means you 2417 * may not sleep between calling this and putting something into 2418 * the entry, as someone else might have used it while you slept. 2419 */ 2420 static int ext4_add_entry(handle_t *handle, struct dentry *dentry, 2421 struct inode *inode) 2422 { 2423 struct inode *dir = d_inode(dentry->d_parent); 2424 struct buffer_head *bh = NULL; 2425 struct ext4_dir_entry_2 *de; 2426 struct super_block *sb; 2427 struct ext4_filename fname; 2428 int retval; 2429 int dx_fallback=0; 2430 unsigned blocksize; 2431 ext4_lblk_t block, blocks; 2432 int csum_size = 0; 2433 2434 if (ext4_has_metadata_csum(inode->i_sb)) 2435 csum_size = sizeof(struct ext4_dir_entry_tail); 2436 2437 sb = dir->i_sb; 2438 blocksize = sb->s_blocksize; 2439 if (!dentry->d_name.len) 2440 return -EINVAL; 2441 2442 if (fscrypt_is_nokey_name(dentry)) 2443 return -ENOKEY; 2444 2445 #if IS_ENABLED(CONFIG_UNICODE) 2446 if (sb_has_strict_encoding(sb) && IS_CASEFOLDED(dir) && 2447 utf8_validate(sb->s_encoding, &dentry->d_name)) 2448 return -EINVAL; 2449 #endif 2450 2451 retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname); 2452 if (retval) 2453 return retval; 2454 2455 if (ext4_has_inline_data(dir)) { 2456 retval = ext4_try_add_inline_entry(handle, &fname, dir, inode); 2457 if (retval < 0) 2458 goto out; 2459 if (retval == 1) { 2460 retval = 0; 2461 goto out; 2462 } 2463 } 2464 2465 if (is_dx(dir)) { 2466 retval = ext4_dx_add_entry(handle, &fname, dir, inode); 2467 if (!retval || (retval != ERR_BAD_DX_DIR)) 2468 goto out; 2469 /* Can we just ignore htree data? */ 2470 if (ext4_has_metadata_csum(sb)) { 2471 EXT4_ERROR_INODE(dir, 2472 "Directory has corrupted htree index."); 2473 retval = -EFSCORRUPTED; 2474 goto out; 2475 } 2476 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX); 2477 dx_fallback++; 2478 retval = ext4_mark_inode_dirty(handle, dir); 2479 if (unlikely(retval)) 2480 goto out; 2481 } 2482 blocks = dir->i_size >> sb->s_blocksize_bits; 2483 for (block = 0; block < blocks; block++) { 2484 bh = ext4_read_dirblock(dir, block, DIRENT); 2485 if (bh == NULL) { 2486 bh = ext4_bread(handle, dir, block, 2487 EXT4_GET_BLOCKS_CREATE); 2488 goto add_to_new_block; 2489 } 2490 if (IS_ERR(bh)) { 2491 retval = PTR_ERR(bh); 2492 bh = NULL; 2493 goto out; 2494 } 2495 retval = add_dirent_to_buf(handle, &fname, dir, inode, 2496 NULL, bh); 2497 if (retval != -ENOSPC) 2498 goto out; 2499 2500 if (blocks == 1 && !dx_fallback && 2501 ext4_has_feature_dir_index(sb)) { 2502 retval = make_indexed_dir(handle, &fname, dir, 2503 inode, bh); 2504 bh = NULL; /* make_indexed_dir releases bh */ 2505 goto out; 2506 } 2507 brelse(bh); 2508 } 2509 bh = ext4_append(handle, dir, &block); 2510 add_to_new_block: 2511 if (IS_ERR(bh)) { 2512 retval = PTR_ERR(bh); 2513 bh = NULL; 2514 goto out; 2515 } 2516 de = (struct ext4_dir_entry_2 *) bh->b_data; 2517 de->inode = 0; 2518 de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize); 2519 2520 if (csum_size) 2521 ext4_initialize_dirent_tail(bh, blocksize); 2522 2523 retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh); 2524 out: 2525 ext4_fname_free_filename(&fname); 2526 brelse(bh); 2527 if (retval == 0) 2528 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY); 2529 return retval; 2530 } 2531 2532 /* 2533 * Returns 0 for success, or a negative error value 2534 */ 2535 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname, 2536 struct inode *dir, struct inode *inode) 2537 { 2538 struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; 2539 struct dx_entry *entries, *at; 2540 struct buffer_head *bh; 2541 struct super_block *sb = dir->i_sb; 2542 struct ext4_dir_entry_2 *de; 2543 int restart; 2544 int err; 2545 2546 again: 2547 restart = 0; 2548 frame = dx_probe(fname, dir, NULL, frames); 2549 if (IS_ERR(frame)) 2550 return PTR_ERR(frame); 2551 entries = frame->entries; 2552 at = frame->at; 2553 bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT_HTREE); 2554 if (IS_ERR(bh)) { 2555 err = PTR_ERR(bh); 2556 bh = NULL; 2557 goto cleanup; 2558 } 2559 2560 BUFFER_TRACE(bh, "get_write_access"); 2561 err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE); 2562 if (err) 2563 goto journal_error; 2564 2565 err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh); 2566 if (err != -ENOSPC) 2567 goto cleanup; 2568 2569 err = 0; 2570 /* Block full, should compress but for now just split */ 2571 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n", 2572 dx_get_count(entries), dx_get_limit(entries))); 2573 /* Need to split index? */ 2574 if (dx_get_count(entries) == dx_get_limit(entries)) { 2575 ext4_lblk_t newblock; 2576 int levels = frame - frames + 1; 2577 unsigned int icount; 2578 int add_level = 1; 2579 struct dx_entry *entries2; 2580 struct dx_node *node2; 2581 struct buffer_head *bh2; 2582 2583 while (frame > frames) { 2584 if (dx_get_count((frame - 1)->entries) < 2585 dx_get_limit((frame - 1)->entries)) { 2586 add_level = 0; 2587 break; 2588 } 2589 frame--; /* split higher index block */ 2590 at = frame->at; 2591 entries = frame->entries; 2592 restart = 1; 2593 } 2594 if (add_level && levels == ext4_dir_htree_level(sb)) { 2595 ext4_warning(sb, "Directory (ino: %lu) index full, " 2596 "reach max htree level :%d", 2597 dir->i_ino, levels); 2598 if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) { 2599 ext4_warning(sb, "Large directory feature is " 2600 "not enabled on this " 2601 "filesystem"); 2602 } 2603 err = -ENOSPC; 2604 goto cleanup; 2605 } 2606 icount = dx_get_count(entries); 2607 bh2 = ext4_append(handle, dir, &newblock); 2608 if (IS_ERR(bh2)) { 2609 err = PTR_ERR(bh2); 2610 goto cleanup; 2611 } 2612 node2 = (struct dx_node *)(bh2->b_data); 2613 entries2 = node2->entries; 2614 memset(&node2->fake, 0, sizeof(struct fake_dirent)); 2615 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize, 2616 sb->s_blocksize); 2617 BUFFER_TRACE(frame->bh, "get_write_access"); 2618 err = ext4_journal_get_write_access(handle, sb, frame->bh, 2619 EXT4_JTR_NONE); 2620 if (err) 2621 goto journal_error; 2622 if (!add_level) { 2623 unsigned icount1 = icount/2, icount2 = icount - icount1; 2624 unsigned hash2 = dx_get_hash(entries + icount1); 2625 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n", 2626 icount1, icount2)); 2627 2628 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */ 2629 err = ext4_journal_get_write_access(handle, sb, 2630 (frame - 1)->bh, 2631 EXT4_JTR_NONE); 2632 if (err) 2633 goto journal_error; 2634 2635 memcpy((char *) entries2, (char *) (entries + icount1), 2636 icount2 * sizeof(struct dx_entry)); 2637 dx_set_count(entries, icount1); 2638 dx_set_count(entries2, icount2); 2639 dx_set_limit(entries2, dx_node_limit(dir)); 2640 2641 /* Which index block gets the new entry? */ 2642 if (at - entries >= icount1) { 2643 frame->at = at - entries - icount1 + entries2; 2644 frame->entries = entries = entries2; 2645 swap(frame->bh, bh2); 2646 } 2647 dx_insert_block((frame - 1), hash2, newblock); 2648 dxtrace(dx_show_index("node", frame->entries)); 2649 dxtrace(dx_show_index("node", 2650 ((struct dx_node *) bh2->b_data)->entries)); 2651 err = ext4_handle_dirty_dx_node(handle, dir, bh2); 2652 if (err) 2653 goto journal_error; 2654 brelse (bh2); 2655 err = ext4_handle_dirty_dx_node(handle, dir, 2656 (frame - 1)->bh); 2657 if (err) 2658 goto journal_error; 2659 err = ext4_handle_dirty_dx_node(handle, dir, 2660 frame->bh); 2661 if (restart || err) 2662 goto journal_error; 2663 } else { 2664 struct dx_root *dxroot; 2665 memcpy((char *) entries2, (char *) entries, 2666 icount * sizeof(struct dx_entry)); 2667 dx_set_limit(entries2, dx_node_limit(dir)); 2668 2669 /* Set up root */ 2670 dx_set_count(entries, 1); 2671 dx_set_block(entries + 0, newblock); 2672 dxroot = (struct dx_root *)frames[0].bh->b_data; 2673 dxroot->info.indirect_levels += 1; 2674 dxtrace(printk(KERN_DEBUG 2675 "Creating %d level index...\n", 2676 dxroot->info.indirect_levels)); 2677 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 2678 if (err) 2679 goto journal_error; 2680 err = ext4_handle_dirty_dx_node(handle, dir, bh2); 2681 brelse(bh2); 2682 restart = 1; 2683 goto journal_error; 2684 } 2685 } 2686 de = do_split(handle, dir, &bh, frame, &fname->hinfo); 2687 if (IS_ERR(de)) { 2688 err = PTR_ERR(de); 2689 goto cleanup; 2690 } 2691 err = add_dirent_to_buf(handle, fname, dir, inode, de, bh); 2692 goto cleanup; 2693 2694 journal_error: 2695 ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */ 2696 cleanup: 2697 brelse(bh); 2698 dx_release(frames); 2699 /* @restart is true means htree-path has been changed, we need to 2700 * repeat dx_probe() to find out valid htree-path 2701 */ 2702 if (restart && err == 0) 2703 goto again; 2704 return err; 2705 } 2706 2707 /* 2708 * ext4_generic_delete_entry deletes a directory entry by merging it 2709 * with the previous entry 2710 */ 2711 int ext4_generic_delete_entry(struct inode *dir, 2712 struct ext4_dir_entry_2 *de_del, 2713 struct buffer_head *bh, 2714 void *entry_buf, 2715 int buf_size, 2716 int csum_size) 2717 { 2718 struct ext4_dir_entry_2 *de, *pde; 2719 unsigned int blocksize = dir->i_sb->s_blocksize; 2720 int i; 2721 2722 i = 0; 2723 pde = NULL; 2724 de = entry_buf; 2725 while (i < buf_size - csum_size) { 2726 if (ext4_check_dir_entry(dir, NULL, de, bh, 2727 entry_buf, buf_size, i)) 2728 return -EFSCORRUPTED; 2729 if (de == de_del) { 2730 if (pde) { 2731 pde->rec_len = ext4_rec_len_to_disk( 2732 ext4_rec_len_from_disk(pde->rec_len, 2733 blocksize) + 2734 ext4_rec_len_from_disk(de->rec_len, 2735 blocksize), 2736 blocksize); 2737 2738 /* wipe entire dir_entry */ 2739 memset(de, 0, ext4_rec_len_from_disk(de->rec_len, 2740 blocksize)); 2741 } else { 2742 /* wipe dir_entry excluding the rec_len field */ 2743 de->inode = 0; 2744 memset(&de->name_len, 0, 2745 ext4_rec_len_from_disk(de->rec_len, 2746 blocksize) - 2747 offsetof(struct ext4_dir_entry_2, 2748 name_len)); 2749 } 2750 2751 inode_inc_iversion(dir); 2752 return 0; 2753 } 2754 i += ext4_rec_len_from_disk(de->rec_len, blocksize); 2755 pde = de; 2756 de = ext4_next_entry(de, blocksize); 2757 } 2758 return -ENOENT; 2759 } 2760 2761 static int ext4_delete_entry(handle_t *handle, 2762 struct inode *dir, 2763 struct ext4_dir_entry_2 *de_del, 2764 struct buffer_head *bh) 2765 { 2766 int err, csum_size = 0; 2767 2768 if (ext4_has_inline_data(dir)) { 2769 int has_inline_data = 1; 2770 err = ext4_delete_inline_entry(handle, dir, de_del, bh, 2771 &has_inline_data); 2772 if (has_inline_data) 2773 return err; 2774 } 2775 2776 if (ext4_has_metadata_csum(dir->i_sb)) 2777 csum_size = sizeof(struct ext4_dir_entry_tail); 2778 2779 BUFFER_TRACE(bh, "get_write_access"); 2780 err = ext4_journal_get_write_access(handle, dir->i_sb, bh, 2781 EXT4_JTR_NONE); 2782 if (unlikely(err)) 2783 goto out; 2784 2785 err = ext4_generic_delete_entry(dir, de_del, bh, bh->b_data, 2786 dir->i_sb->s_blocksize, csum_size); 2787 if (err) 2788 goto out; 2789 2790 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); 2791 err = ext4_handle_dirty_dirblock(handle, dir, bh); 2792 if (unlikely(err)) 2793 goto out; 2794 2795 return 0; 2796 out: 2797 if (err != -ENOENT) 2798 ext4_std_error(dir->i_sb, err); 2799 return err; 2800 } 2801 2802 /* 2803 * Set directory link count to 1 if nlinks > EXT4_LINK_MAX, or if nlinks == 2 2804 * since this indicates that nlinks count was previously 1 to avoid overflowing 2805 * the 16-bit i_links_count field on disk. Directories with i_nlink == 1 mean 2806 * that subdirectory link counts are not being maintained accurately. 2807 * 2808 * The caller has already checked for i_nlink overflow in case the DIR_LINK 2809 * feature is not enabled and returned -EMLINK. The is_dx() check is a proxy 2810 * for checking S_ISDIR(inode) (since the INODE_INDEX feature will not be set 2811 * on regular files) and to avoid creating huge/slow non-HTREE directories. 2812 */ 2813 static void ext4_inc_count(struct inode *inode) 2814 { 2815 inc_nlink(inode); 2816 if (is_dx(inode) && 2817 (inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2)) 2818 set_nlink(inode, 1); 2819 } 2820 2821 /* 2822 * If a directory had nlink == 1, then we should let it be 1. This indicates 2823 * directory has >EXT4_LINK_MAX subdirs. 2824 */ 2825 static void ext4_dec_count(struct inode *inode) 2826 { 2827 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2) 2828 drop_nlink(inode); 2829 } 2830 2831 2832 /* 2833 * Add non-directory inode to a directory. On success, the inode reference is 2834 * consumed by dentry is instantiation. This is also indicated by clearing of 2835 * *inodep pointer. On failure, the caller is responsible for dropping the 2836 * inode reference in the safe context. 2837 */ 2838 static int ext4_add_nondir(handle_t *handle, 2839 struct dentry *dentry, struct inode **inodep) 2840 { 2841 struct inode *dir = d_inode(dentry->d_parent); 2842 struct inode *inode = *inodep; 2843 int err = ext4_add_entry(handle, dentry, inode); 2844 if (!err) { 2845 err = ext4_mark_inode_dirty(handle, inode); 2846 if (IS_DIRSYNC(dir)) 2847 ext4_handle_sync(handle); 2848 d_instantiate_new(dentry, inode); 2849 *inodep = NULL; 2850 return err; 2851 } 2852 drop_nlink(inode); 2853 ext4_mark_inode_dirty(handle, inode); 2854 ext4_orphan_add(handle, inode); 2855 unlock_new_inode(inode); 2856 return err; 2857 } 2858 2859 /* 2860 * By the time this is called, we already have created 2861 * the directory cache entry for the new file, but it 2862 * is so far negative - it has no inode. 2863 * 2864 * If the create succeeds, we fill in the inode information 2865 * with d_instantiate(). 2866 */ 2867 static int ext4_create(struct mnt_idmap *idmap, struct inode *dir, 2868 struct dentry *dentry, umode_t mode, bool excl) 2869 { 2870 handle_t *handle; 2871 struct inode *inode; 2872 int err, credits, retries = 0; 2873 2874 err = dquot_initialize(dir); 2875 if (err) 2876 return err; 2877 2878 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2879 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2880 retry: 2881 inode = ext4_new_inode_start_handle(idmap, dir, mode, &dentry->d_name, 2882 0, NULL, EXT4_HT_DIR, credits); 2883 handle = ext4_journal_current_handle(); 2884 err = PTR_ERR(inode); 2885 if (!IS_ERR(inode)) { 2886 inode->i_op = &ext4_file_inode_operations; 2887 inode->i_fop = &ext4_file_operations; 2888 ext4_set_aops(inode); 2889 err = ext4_add_nondir(handle, dentry, &inode); 2890 if (!err) 2891 ext4_fc_track_create(handle, dentry); 2892 } 2893 if (handle) 2894 ext4_journal_stop(handle); 2895 if (!IS_ERR_OR_NULL(inode)) 2896 iput(inode); 2897 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2898 goto retry; 2899 return err; 2900 } 2901 2902 static int ext4_mknod(struct mnt_idmap *idmap, struct inode *dir, 2903 struct dentry *dentry, umode_t mode, dev_t rdev) 2904 { 2905 handle_t *handle; 2906 struct inode *inode; 2907 int err, credits, retries = 0; 2908 2909 err = dquot_initialize(dir); 2910 if (err) 2911 return err; 2912 2913 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2914 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2915 retry: 2916 inode = ext4_new_inode_start_handle(idmap, dir, mode, &dentry->d_name, 2917 0, NULL, EXT4_HT_DIR, credits); 2918 handle = ext4_journal_current_handle(); 2919 err = PTR_ERR(inode); 2920 if (!IS_ERR(inode)) { 2921 init_special_inode(inode, inode->i_mode, rdev); 2922 inode->i_op = &ext4_special_inode_operations; 2923 err = ext4_add_nondir(handle, dentry, &inode); 2924 if (!err) 2925 ext4_fc_track_create(handle, dentry); 2926 } 2927 if (handle) 2928 ext4_journal_stop(handle); 2929 if (!IS_ERR_OR_NULL(inode)) 2930 iput(inode); 2931 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2932 goto retry; 2933 return err; 2934 } 2935 2936 static int ext4_tmpfile(struct mnt_idmap *idmap, struct inode *dir, 2937 struct file *file, umode_t mode) 2938 { 2939 handle_t *handle; 2940 struct inode *inode; 2941 int err, retries = 0; 2942 2943 err = dquot_initialize(dir); 2944 if (err) 2945 return err; 2946 2947 retry: 2948 inode = ext4_new_inode_start_handle(idmap, dir, mode, 2949 NULL, 0, NULL, 2950 EXT4_HT_DIR, 2951 EXT4_MAXQUOTAS_TRANS_BLOCKS(dir->i_sb) + 2952 4 + EXT4_XATTR_TRANS_BLOCKS); 2953 handle = ext4_journal_current_handle(); 2954 err = PTR_ERR(inode); 2955 if (!IS_ERR(inode)) { 2956 inode->i_op = &ext4_file_inode_operations; 2957 inode->i_fop = &ext4_file_operations; 2958 ext4_set_aops(inode); 2959 d_tmpfile(file, inode); 2960 err = ext4_orphan_add(handle, inode); 2961 if (err) 2962 goto err_unlock_inode; 2963 mark_inode_dirty(inode); 2964 unlock_new_inode(inode); 2965 } 2966 if (handle) 2967 ext4_journal_stop(handle); 2968 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2969 goto retry; 2970 return finish_open_simple(file, err); 2971 err_unlock_inode: 2972 ext4_journal_stop(handle); 2973 unlock_new_inode(inode); 2974 return err; 2975 } 2976 2977 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode, 2978 struct ext4_dir_entry_2 *de, 2979 int blocksize, int csum_size, 2980 unsigned int parent_ino, int dotdot_real_len) 2981 { 2982 de->inode = cpu_to_le32(inode->i_ino); 2983 de->name_len = 1; 2984 de->rec_len = ext4_rec_len_to_disk(ext4_dir_rec_len(de->name_len, NULL), 2985 blocksize); 2986 strcpy(de->name, "."); 2987 ext4_set_de_type(inode->i_sb, de, S_IFDIR); 2988 2989 de = ext4_next_entry(de, blocksize); 2990 de->inode = cpu_to_le32(parent_ino); 2991 de->name_len = 2; 2992 if (!dotdot_real_len) 2993 de->rec_len = ext4_rec_len_to_disk(blocksize - 2994 (csum_size + ext4_dir_rec_len(1, NULL)), 2995 blocksize); 2996 else 2997 de->rec_len = ext4_rec_len_to_disk( 2998 ext4_dir_rec_len(de->name_len, NULL), 2999 blocksize); 3000 strcpy(de->name, ".."); 3001 ext4_set_de_type(inode->i_sb, de, S_IFDIR); 3002 3003 return ext4_next_entry(de, blocksize); 3004 } 3005 3006 int ext4_init_new_dir(handle_t *handle, struct inode *dir, 3007 struct inode *inode) 3008 { 3009 struct buffer_head *dir_block = NULL; 3010 struct ext4_dir_entry_2 *de; 3011 ext4_lblk_t block = 0; 3012 unsigned int blocksize = dir->i_sb->s_blocksize; 3013 int csum_size = 0; 3014 int err; 3015 3016 if (ext4_has_metadata_csum(dir->i_sb)) 3017 csum_size = sizeof(struct ext4_dir_entry_tail); 3018 3019 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) { 3020 err = ext4_try_create_inline_dir(handle, dir, inode); 3021 if (err < 0 && err != -ENOSPC) 3022 goto out; 3023 if (!err) 3024 goto out; 3025 } 3026 3027 inode->i_size = 0; 3028 dir_block = ext4_append(handle, inode, &block); 3029 if (IS_ERR(dir_block)) 3030 return PTR_ERR(dir_block); 3031 de = (struct ext4_dir_entry_2 *)dir_block->b_data; 3032 ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0); 3033 set_nlink(inode, 2); 3034 if (csum_size) 3035 ext4_initialize_dirent_tail(dir_block, blocksize); 3036 3037 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata"); 3038 err = ext4_handle_dirty_dirblock(handle, inode, dir_block); 3039 if (err) 3040 goto out; 3041 set_buffer_verified(dir_block); 3042 out: 3043 brelse(dir_block); 3044 return err; 3045 } 3046 3047 static int ext4_mkdir(struct mnt_idmap *idmap, struct inode *dir, 3048 struct dentry *dentry, umode_t mode) 3049 { 3050 handle_t *handle; 3051 struct inode *inode; 3052 int err, err2 = 0, credits, retries = 0; 3053 3054 if (EXT4_DIR_LINK_MAX(dir)) 3055 return -EMLINK; 3056 3057 err = dquot_initialize(dir); 3058 if (err) 3059 return err; 3060 3061 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3062 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 3063 retry: 3064 inode = ext4_new_inode_start_handle(idmap, dir, S_IFDIR | mode, 3065 &dentry->d_name, 3066 0, NULL, EXT4_HT_DIR, credits); 3067 handle = ext4_journal_current_handle(); 3068 err = PTR_ERR(inode); 3069 if (IS_ERR(inode)) 3070 goto out_stop; 3071 3072 inode->i_op = &ext4_dir_inode_operations; 3073 inode->i_fop = &ext4_dir_operations; 3074 err = ext4_init_new_dir(handle, dir, inode); 3075 if (err) 3076 goto out_clear_inode; 3077 err = ext4_mark_inode_dirty(handle, inode); 3078 if (!err) 3079 err = ext4_add_entry(handle, dentry, inode); 3080 if (err) { 3081 out_clear_inode: 3082 clear_nlink(inode); 3083 ext4_orphan_add(handle, inode); 3084 unlock_new_inode(inode); 3085 err2 = ext4_mark_inode_dirty(handle, inode); 3086 if (unlikely(err2)) 3087 err = err2; 3088 ext4_journal_stop(handle); 3089 iput(inode); 3090 goto out_retry; 3091 } 3092 ext4_inc_count(dir); 3093 3094 ext4_update_dx_flag(dir); 3095 err = ext4_mark_inode_dirty(handle, dir); 3096 if (err) 3097 goto out_clear_inode; 3098 d_instantiate_new(dentry, inode); 3099 ext4_fc_track_create(handle, dentry); 3100 if (IS_DIRSYNC(dir)) 3101 ext4_handle_sync(handle); 3102 3103 out_stop: 3104 if (handle) 3105 ext4_journal_stop(handle); 3106 out_retry: 3107 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 3108 goto retry; 3109 return err; 3110 } 3111 3112 /* 3113 * routine to check that the specified directory is empty (for rmdir) 3114 */ 3115 bool ext4_empty_dir(struct inode *inode) 3116 { 3117 unsigned int offset; 3118 struct buffer_head *bh; 3119 struct ext4_dir_entry_2 *de; 3120 struct super_block *sb; 3121 3122 if (ext4_has_inline_data(inode)) { 3123 int has_inline_data = 1; 3124 int ret; 3125 3126 ret = empty_inline_dir(inode, &has_inline_data); 3127 if (has_inline_data) 3128 return ret; 3129 } 3130 3131 sb = inode->i_sb; 3132 if (inode->i_size < ext4_dir_rec_len(1, NULL) + 3133 ext4_dir_rec_len(2, NULL)) { 3134 EXT4_ERROR_INODE(inode, "invalid size"); 3135 return false; 3136 } 3137 bh = ext4_read_dirblock(inode, 0, EITHER); 3138 if (IS_ERR(bh)) 3139 return false; 3140 3141 de = (struct ext4_dir_entry_2 *) bh->b_data; 3142 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size, 3143 0) || 3144 le32_to_cpu(de->inode) != inode->i_ino || strcmp(".", de->name)) { 3145 ext4_warning_inode(inode, "directory missing '.'"); 3146 brelse(bh); 3147 return false; 3148 } 3149 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); 3150 de = ext4_next_entry(de, sb->s_blocksize); 3151 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size, 3152 offset) || 3153 le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) { 3154 ext4_warning_inode(inode, "directory missing '..'"); 3155 brelse(bh); 3156 return false; 3157 } 3158 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); 3159 while (offset < inode->i_size) { 3160 if (!(offset & (sb->s_blocksize - 1))) { 3161 unsigned int lblock; 3162 brelse(bh); 3163 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb); 3164 bh = ext4_read_dirblock(inode, lblock, EITHER); 3165 if (bh == NULL) { 3166 offset += sb->s_blocksize; 3167 continue; 3168 } 3169 if (IS_ERR(bh)) 3170 return false; 3171 } 3172 de = (struct ext4_dir_entry_2 *) (bh->b_data + 3173 (offset & (sb->s_blocksize - 1))); 3174 if (ext4_check_dir_entry(inode, NULL, de, bh, 3175 bh->b_data, bh->b_size, offset) || 3176 le32_to_cpu(de->inode)) { 3177 brelse(bh); 3178 return false; 3179 } 3180 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); 3181 } 3182 brelse(bh); 3183 return true; 3184 } 3185 3186 static int ext4_rmdir(struct inode *dir, struct dentry *dentry) 3187 { 3188 int retval; 3189 struct inode *inode; 3190 struct buffer_head *bh; 3191 struct ext4_dir_entry_2 *de; 3192 handle_t *handle = NULL; 3193 3194 if (unlikely(ext4_forced_shutdown(dir->i_sb))) 3195 return -EIO; 3196 3197 /* Initialize quotas before so that eventual writes go in 3198 * separate transaction */ 3199 retval = dquot_initialize(dir); 3200 if (retval) 3201 return retval; 3202 retval = dquot_initialize(d_inode(dentry)); 3203 if (retval) 3204 return retval; 3205 3206 retval = -ENOENT; 3207 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); 3208 if (IS_ERR(bh)) 3209 return PTR_ERR(bh); 3210 if (!bh) 3211 goto end_rmdir; 3212 3213 inode = d_inode(dentry); 3214 3215 retval = -EFSCORRUPTED; 3216 if (le32_to_cpu(de->inode) != inode->i_ino) 3217 goto end_rmdir; 3218 3219 retval = -ENOTEMPTY; 3220 if (!ext4_empty_dir(inode)) 3221 goto end_rmdir; 3222 3223 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3224 EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); 3225 if (IS_ERR(handle)) { 3226 retval = PTR_ERR(handle); 3227 handle = NULL; 3228 goto end_rmdir; 3229 } 3230 3231 if (IS_DIRSYNC(dir)) 3232 ext4_handle_sync(handle); 3233 3234 retval = ext4_delete_entry(handle, dir, de, bh); 3235 if (retval) 3236 goto end_rmdir; 3237 if (!EXT4_DIR_LINK_EMPTY(inode)) 3238 ext4_warning_inode(inode, 3239 "empty directory '%.*s' has too many links (%u)", 3240 dentry->d_name.len, dentry->d_name.name, 3241 inode->i_nlink); 3242 inode_inc_iversion(inode); 3243 clear_nlink(inode); 3244 /* There's no need to set i_disksize: the fact that i_nlink is 3245 * zero will ensure that the right thing happens during any 3246 * recovery. */ 3247 inode->i_size = 0; 3248 ext4_orphan_add(handle, inode); 3249 dir->i_mtime = inode_set_ctime_current(dir); 3250 inode_set_ctime_current(inode); 3251 retval = ext4_mark_inode_dirty(handle, inode); 3252 if (retval) 3253 goto end_rmdir; 3254 ext4_dec_count(dir); 3255 ext4_update_dx_flag(dir); 3256 ext4_fc_track_unlink(handle, dentry); 3257 retval = ext4_mark_inode_dirty(handle, dir); 3258 3259 #if IS_ENABLED(CONFIG_UNICODE) 3260 /* VFS negative dentries are incompatible with Encoding and 3261 * Case-insensitiveness. Eventually we'll want avoid 3262 * invalidating the dentries here, alongside with returning the 3263 * negative dentries at ext4_lookup(), when it is better 3264 * supported by the VFS for the CI case. 3265 */ 3266 if (IS_CASEFOLDED(dir)) 3267 d_invalidate(dentry); 3268 #endif 3269 3270 end_rmdir: 3271 brelse(bh); 3272 if (handle) 3273 ext4_journal_stop(handle); 3274 return retval; 3275 } 3276 3277 int __ext4_unlink(struct inode *dir, const struct qstr *d_name, 3278 struct inode *inode, 3279 struct dentry *dentry /* NULL during fast_commit recovery */) 3280 { 3281 int retval = -ENOENT; 3282 struct buffer_head *bh; 3283 struct ext4_dir_entry_2 *de; 3284 handle_t *handle; 3285 int skip_remove_dentry = 0; 3286 3287 /* 3288 * Keep this outside the transaction; it may have to set up the 3289 * directory's encryption key, which isn't GFP_NOFS-safe. 3290 */ 3291 bh = ext4_find_entry(dir, d_name, &de, NULL); 3292 if (IS_ERR(bh)) 3293 return PTR_ERR(bh); 3294 3295 if (!bh) 3296 return -ENOENT; 3297 3298 if (le32_to_cpu(de->inode) != inode->i_ino) { 3299 /* 3300 * It's okay if we find dont find dentry which matches 3301 * the inode. That's because it might have gotten 3302 * renamed to a different inode number 3303 */ 3304 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY) 3305 skip_remove_dentry = 1; 3306 else 3307 goto out_bh; 3308 } 3309 3310 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3311 EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); 3312 if (IS_ERR(handle)) { 3313 retval = PTR_ERR(handle); 3314 goto out_bh; 3315 } 3316 3317 if (IS_DIRSYNC(dir)) 3318 ext4_handle_sync(handle); 3319 3320 if (!skip_remove_dentry) { 3321 retval = ext4_delete_entry(handle, dir, de, bh); 3322 if (retval) 3323 goto out_handle; 3324 dir->i_mtime = inode_set_ctime_current(dir); 3325 ext4_update_dx_flag(dir); 3326 retval = ext4_mark_inode_dirty(handle, dir); 3327 if (retval) 3328 goto out_handle; 3329 } else { 3330 retval = 0; 3331 } 3332 if (inode->i_nlink == 0) 3333 ext4_warning_inode(inode, "Deleting file '%.*s' with no links", 3334 d_name->len, d_name->name); 3335 else 3336 drop_nlink(inode); 3337 if (!inode->i_nlink) 3338 ext4_orphan_add(handle, inode); 3339 inode_set_ctime_current(inode); 3340 retval = ext4_mark_inode_dirty(handle, inode); 3341 if (dentry && !retval) 3342 ext4_fc_track_unlink(handle, dentry); 3343 out_handle: 3344 ext4_journal_stop(handle); 3345 out_bh: 3346 brelse(bh); 3347 return retval; 3348 } 3349 3350 static int ext4_unlink(struct inode *dir, struct dentry *dentry) 3351 { 3352 int retval; 3353 3354 if (unlikely(ext4_forced_shutdown(dir->i_sb))) 3355 return -EIO; 3356 3357 trace_ext4_unlink_enter(dir, dentry); 3358 /* 3359 * Initialize quotas before so that eventual writes go 3360 * in separate transaction 3361 */ 3362 retval = dquot_initialize(dir); 3363 if (retval) 3364 goto out_trace; 3365 retval = dquot_initialize(d_inode(dentry)); 3366 if (retval) 3367 goto out_trace; 3368 3369 retval = __ext4_unlink(dir, &dentry->d_name, d_inode(dentry), dentry); 3370 #if IS_ENABLED(CONFIG_UNICODE) 3371 /* VFS negative dentries are incompatible with Encoding and 3372 * Case-insensitiveness. Eventually we'll want avoid 3373 * invalidating the dentries here, alongside with returning the 3374 * negative dentries at ext4_lookup(), when it is better 3375 * supported by the VFS for the CI case. 3376 */ 3377 if (IS_CASEFOLDED(dir)) 3378 d_invalidate(dentry); 3379 #endif 3380 3381 out_trace: 3382 trace_ext4_unlink_exit(dentry, retval); 3383 return retval; 3384 } 3385 3386 static int ext4_init_symlink_block(handle_t *handle, struct inode *inode, 3387 struct fscrypt_str *disk_link) 3388 { 3389 struct buffer_head *bh; 3390 char *kaddr; 3391 int err = 0; 3392 3393 bh = ext4_bread(handle, inode, 0, EXT4_GET_BLOCKS_CREATE); 3394 if (IS_ERR(bh)) 3395 return PTR_ERR(bh); 3396 3397 BUFFER_TRACE(bh, "get_write_access"); 3398 err = ext4_journal_get_write_access(handle, inode->i_sb, bh, EXT4_JTR_NONE); 3399 if (err) 3400 goto out; 3401 3402 kaddr = (char *)bh->b_data; 3403 memcpy(kaddr, disk_link->name, disk_link->len); 3404 inode->i_size = disk_link->len - 1; 3405 EXT4_I(inode)->i_disksize = inode->i_size; 3406 err = ext4_handle_dirty_metadata(handle, inode, bh); 3407 out: 3408 brelse(bh); 3409 return err; 3410 } 3411 3412 static int ext4_symlink(struct mnt_idmap *idmap, struct inode *dir, 3413 struct dentry *dentry, const char *symname) 3414 { 3415 handle_t *handle; 3416 struct inode *inode; 3417 int err, len = strlen(symname); 3418 int credits; 3419 struct fscrypt_str disk_link; 3420 int retries = 0; 3421 3422 if (unlikely(ext4_forced_shutdown(dir->i_sb))) 3423 return -EIO; 3424 3425 err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize, 3426 &disk_link); 3427 if (err) 3428 return err; 3429 3430 err = dquot_initialize(dir); 3431 if (err) 3432 return err; 3433 3434 /* 3435 * EXT4_INDEX_EXTRA_TRANS_BLOCKS for addition of entry into the 3436 * directory. +3 for inode, inode bitmap, group descriptor allocation. 3437 * EXT4_DATA_TRANS_BLOCKS for the data block allocation and 3438 * modification. 3439 */ 3440 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3441 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3; 3442 retry: 3443 inode = ext4_new_inode_start_handle(idmap, dir, S_IFLNK|S_IRWXUGO, 3444 &dentry->d_name, 0, NULL, 3445 EXT4_HT_DIR, credits); 3446 handle = ext4_journal_current_handle(); 3447 if (IS_ERR(inode)) { 3448 if (handle) 3449 ext4_journal_stop(handle); 3450 err = PTR_ERR(inode); 3451 goto out_retry; 3452 } 3453 3454 if (IS_ENCRYPTED(inode)) { 3455 err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link); 3456 if (err) 3457 goto err_drop_inode; 3458 inode->i_op = &ext4_encrypted_symlink_inode_operations; 3459 } else { 3460 if ((disk_link.len > EXT4_N_BLOCKS * 4)) { 3461 inode->i_op = &ext4_symlink_inode_operations; 3462 } else { 3463 inode->i_op = &ext4_fast_symlink_inode_operations; 3464 inode->i_link = (char *)&EXT4_I(inode)->i_data; 3465 } 3466 } 3467 3468 if ((disk_link.len > EXT4_N_BLOCKS * 4)) { 3469 /* alloc symlink block and fill it */ 3470 err = ext4_init_symlink_block(handle, inode, &disk_link); 3471 if (err) 3472 goto err_drop_inode; 3473 } else { 3474 /* clear the extent format for fast symlink */ 3475 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS); 3476 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name, 3477 disk_link.len); 3478 inode->i_size = disk_link.len - 1; 3479 EXT4_I(inode)->i_disksize = inode->i_size; 3480 } 3481 err = ext4_add_nondir(handle, dentry, &inode); 3482 if (handle) 3483 ext4_journal_stop(handle); 3484 iput(inode); 3485 goto out_retry; 3486 3487 err_drop_inode: 3488 clear_nlink(inode); 3489 ext4_mark_inode_dirty(handle, inode); 3490 ext4_orphan_add(handle, inode); 3491 unlock_new_inode(inode); 3492 if (handle) 3493 ext4_journal_stop(handle); 3494 iput(inode); 3495 out_retry: 3496 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 3497 goto retry; 3498 if (disk_link.name != (unsigned char *)symname) 3499 kfree(disk_link.name); 3500 return err; 3501 } 3502 3503 int __ext4_link(struct inode *dir, struct inode *inode, struct dentry *dentry) 3504 { 3505 handle_t *handle; 3506 int err, retries = 0; 3507 retry: 3508 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3509 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3510 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1); 3511 if (IS_ERR(handle)) 3512 return PTR_ERR(handle); 3513 3514 if (IS_DIRSYNC(dir)) 3515 ext4_handle_sync(handle); 3516 3517 inode_set_ctime_current(inode); 3518 ext4_inc_count(inode); 3519 ihold(inode); 3520 3521 err = ext4_add_entry(handle, dentry, inode); 3522 if (!err) { 3523 err = ext4_mark_inode_dirty(handle, inode); 3524 /* this can happen only for tmpfile being 3525 * linked the first time 3526 */ 3527 if (inode->i_nlink == 1) 3528 ext4_orphan_del(handle, inode); 3529 d_instantiate(dentry, inode); 3530 ext4_fc_track_link(handle, dentry); 3531 } else { 3532 drop_nlink(inode); 3533 iput(inode); 3534 } 3535 ext4_journal_stop(handle); 3536 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 3537 goto retry; 3538 return err; 3539 } 3540 3541 static int ext4_link(struct dentry *old_dentry, 3542 struct inode *dir, struct dentry *dentry) 3543 { 3544 struct inode *inode = d_inode(old_dentry); 3545 int err; 3546 3547 if (inode->i_nlink >= EXT4_LINK_MAX) 3548 return -EMLINK; 3549 3550 err = fscrypt_prepare_link(old_dentry, dir, dentry); 3551 if (err) 3552 return err; 3553 3554 if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) && 3555 (!projid_eq(EXT4_I(dir)->i_projid, 3556 EXT4_I(old_dentry->d_inode)->i_projid))) 3557 return -EXDEV; 3558 3559 err = dquot_initialize(dir); 3560 if (err) 3561 return err; 3562 return __ext4_link(dir, inode, dentry); 3563 } 3564 3565 /* 3566 * Try to find buffer head where contains the parent block. 3567 * It should be the inode block if it is inlined or the 1st block 3568 * if it is a normal dir. 3569 */ 3570 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle, 3571 struct inode *inode, 3572 int *retval, 3573 struct ext4_dir_entry_2 **parent_de, 3574 int *inlined) 3575 { 3576 struct buffer_head *bh; 3577 3578 if (!ext4_has_inline_data(inode)) { 3579 struct ext4_dir_entry_2 *de; 3580 unsigned int offset; 3581 3582 bh = ext4_read_dirblock(inode, 0, EITHER); 3583 if (IS_ERR(bh)) { 3584 *retval = PTR_ERR(bh); 3585 return NULL; 3586 } 3587 3588 de = (struct ext4_dir_entry_2 *) bh->b_data; 3589 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, 3590 bh->b_size, 0) || 3591 le32_to_cpu(de->inode) != inode->i_ino || 3592 strcmp(".", de->name)) { 3593 EXT4_ERROR_INODE(inode, "directory missing '.'"); 3594 brelse(bh); 3595 *retval = -EFSCORRUPTED; 3596 return NULL; 3597 } 3598 offset = ext4_rec_len_from_disk(de->rec_len, 3599 inode->i_sb->s_blocksize); 3600 de = ext4_next_entry(de, inode->i_sb->s_blocksize); 3601 if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, 3602 bh->b_size, offset) || 3603 le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) { 3604 EXT4_ERROR_INODE(inode, "directory missing '..'"); 3605 brelse(bh); 3606 *retval = -EFSCORRUPTED; 3607 return NULL; 3608 } 3609 *parent_de = de; 3610 3611 return bh; 3612 } 3613 3614 *inlined = 1; 3615 return ext4_get_first_inline_block(inode, parent_de, retval); 3616 } 3617 3618 struct ext4_renament { 3619 struct inode *dir; 3620 struct dentry *dentry; 3621 struct inode *inode; 3622 bool is_dir; 3623 int dir_nlink_delta; 3624 3625 /* entry for "dentry" */ 3626 struct buffer_head *bh; 3627 struct ext4_dir_entry_2 *de; 3628 int inlined; 3629 3630 /* entry for ".." in inode if it's a directory */ 3631 struct buffer_head *dir_bh; 3632 struct ext4_dir_entry_2 *parent_de; 3633 int dir_inlined; 3634 }; 3635 3636 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent) 3637 { 3638 int retval; 3639 3640 ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode, 3641 &retval, &ent->parent_de, 3642 &ent->dir_inlined); 3643 if (!ent->dir_bh) 3644 return retval; 3645 if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino) 3646 return -EFSCORRUPTED; 3647 BUFFER_TRACE(ent->dir_bh, "get_write_access"); 3648 return ext4_journal_get_write_access(handle, ent->dir->i_sb, 3649 ent->dir_bh, EXT4_JTR_NONE); 3650 } 3651 3652 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent, 3653 unsigned dir_ino) 3654 { 3655 int retval; 3656 3657 ent->parent_de->inode = cpu_to_le32(dir_ino); 3658 BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata"); 3659 if (!ent->dir_inlined) { 3660 if (is_dx(ent->inode)) { 3661 retval = ext4_handle_dirty_dx_node(handle, 3662 ent->inode, 3663 ent->dir_bh); 3664 } else { 3665 retval = ext4_handle_dirty_dirblock(handle, ent->inode, 3666 ent->dir_bh); 3667 } 3668 } else { 3669 retval = ext4_mark_inode_dirty(handle, ent->inode); 3670 } 3671 if (retval) { 3672 ext4_std_error(ent->dir->i_sb, retval); 3673 return retval; 3674 } 3675 return 0; 3676 } 3677 3678 static int ext4_setent(handle_t *handle, struct ext4_renament *ent, 3679 unsigned ino, unsigned file_type) 3680 { 3681 int retval, retval2; 3682 3683 BUFFER_TRACE(ent->bh, "get write access"); 3684 retval = ext4_journal_get_write_access(handle, ent->dir->i_sb, ent->bh, 3685 EXT4_JTR_NONE); 3686 if (retval) 3687 return retval; 3688 ent->de->inode = cpu_to_le32(ino); 3689 if (ext4_has_feature_filetype(ent->dir->i_sb)) 3690 ent->de->file_type = file_type; 3691 inode_inc_iversion(ent->dir); 3692 ent->dir->i_mtime = inode_set_ctime_current(ent->dir); 3693 retval = ext4_mark_inode_dirty(handle, ent->dir); 3694 BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata"); 3695 if (!ent->inlined) { 3696 retval2 = ext4_handle_dirty_dirblock(handle, ent->dir, ent->bh); 3697 if (unlikely(retval2)) { 3698 ext4_std_error(ent->dir->i_sb, retval2); 3699 return retval2; 3700 } 3701 } 3702 return retval; 3703 } 3704 3705 static void ext4_resetent(handle_t *handle, struct ext4_renament *ent, 3706 unsigned ino, unsigned file_type) 3707 { 3708 struct ext4_renament old = *ent; 3709 int retval = 0; 3710 3711 /* 3712 * old->de could have moved from under us during make indexed dir, 3713 * so the old->de may no longer valid and need to find it again 3714 * before reset old inode info. 3715 */ 3716 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, 3717 &old.inlined); 3718 if (IS_ERR(old.bh)) 3719 retval = PTR_ERR(old.bh); 3720 if (!old.bh) 3721 retval = -ENOENT; 3722 if (retval) { 3723 ext4_std_error(old.dir->i_sb, retval); 3724 return; 3725 } 3726 3727 ext4_setent(handle, &old, ino, file_type); 3728 brelse(old.bh); 3729 } 3730 3731 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir, 3732 const struct qstr *d_name) 3733 { 3734 int retval = -ENOENT; 3735 struct buffer_head *bh; 3736 struct ext4_dir_entry_2 *de; 3737 3738 bh = ext4_find_entry(dir, d_name, &de, NULL); 3739 if (IS_ERR(bh)) 3740 return PTR_ERR(bh); 3741 if (bh) { 3742 retval = ext4_delete_entry(handle, dir, de, bh); 3743 brelse(bh); 3744 } 3745 return retval; 3746 } 3747 3748 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent, 3749 int force_reread) 3750 { 3751 int retval; 3752 /* 3753 * ent->de could have moved from under us during htree split, so make 3754 * sure that we are deleting the right entry. We might also be pointing 3755 * to a stale entry in the unused part of ent->bh so just checking inum 3756 * and the name isn't enough. 3757 */ 3758 if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino || 3759 ent->de->name_len != ent->dentry->d_name.len || 3760 strncmp(ent->de->name, ent->dentry->d_name.name, 3761 ent->de->name_len) || 3762 force_reread) { 3763 retval = ext4_find_delete_entry(handle, ent->dir, 3764 &ent->dentry->d_name); 3765 } else { 3766 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh); 3767 if (retval == -ENOENT) { 3768 retval = ext4_find_delete_entry(handle, ent->dir, 3769 &ent->dentry->d_name); 3770 } 3771 } 3772 3773 if (retval) { 3774 ext4_warning_inode(ent->dir, 3775 "Deleting old file: nlink %d, error=%d", 3776 ent->dir->i_nlink, retval); 3777 } 3778 } 3779 3780 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent) 3781 { 3782 if (ent->dir_nlink_delta) { 3783 if (ent->dir_nlink_delta == -1) 3784 ext4_dec_count(ent->dir); 3785 else 3786 ext4_inc_count(ent->dir); 3787 ext4_mark_inode_dirty(handle, ent->dir); 3788 } 3789 } 3790 3791 static struct inode *ext4_whiteout_for_rename(struct mnt_idmap *idmap, 3792 struct ext4_renament *ent, 3793 int credits, handle_t **h) 3794 { 3795 struct inode *wh; 3796 handle_t *handle; 3797 int retries = 0; 3798 3799 /* 3800 * for inode block, sb block, group summaries, 3801 * and inode bitmap 3802 */ 3803 credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) + 3804 EXT4_XATTR_TRANS_BLOCKS + 4); 3805 retry: 3806 wh = ext4_new_inode_start_handle(idmap, ent->dir, 3807 S_IFCHR | WHITEOUT_MODE, 3808 &ent->dentry->d_name, 0, NULL, 3809 EXT4_HT_DIR, credits); 3810 3811 handle = ext4_journal_current_handle(); 3812 if (IS_ERR(wh)) { 3813 if (handle) 3814 ext4_journal_stop(handle); 3815 if (PTR_ERR(wh) == -ENOSPC && 3816 ext4_should_retry_alloc(ent->dir->i_sb, &retries)) 3817 goto retry; 3818 } else { 3819 *h = handle; 3820 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV); 3821 wh->i_op = &ext4_special_inode_operations; 3822 } 3823 return wh; 3824 } 3825 3826 /* 3827 * Anybody can rename anything with this: the permission checks are left to the 3828 * higher-level routines. 3829 * 3830 * n.b. old_{dentry,inode) refers to the source dentry/inode 3831 * while new_{dentry,inode) refers to the destination dentry/inode 3832 * This comes from rename(const char *oldpath, const char *newpath) 3833 */ 3834 static int ext4_rename(struct mnt_idmap *idmap, struct inode *old_dir, 3835 struct dentry *old_dentry, struct inode *new_dir, 3836 struct dentry *new_dentry, unsigned int flags) 3837 { 3838 handle_t *handle = NULL; 3839 struct ext4_renament old = { 3840 .dir = old_dir, 3841 .dentry = old_dentry, 3842 .inode = d_inode(old_dentry), 3843 }; 3844 struct ext4_renament new = { 3845 .dir = new_dir, 3846 .dentry = new_dentry, 3847 .inode = d_inode(new_dentry), 3848 }; 3849 int force_reread; 3850 int retval; 3851 struct inode *whiteout = NULL; 3852 int credits; 3853 u8 old_file_type; 3854 3855 if (new.inode && new.inode->i_nlink == 0) { 3856 EXT4_ERROR_INODE(new.inode, 3857 "target of rename is already freed"); 3858 return -EFSCORRUPTED; 3859 } 3860 3861 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) && 3862 (!projid_eq(EXT4_I(new_dir)->i_projid, 3863 EXT4_I(old_dentry->d_inode)->i_projid))) 3864 return -EXDEV; 3865 3866 retval = dquot_initialize(old.dir); 3867 if (retval) 3868 return retval; 3869 retval = dquot_initialize(old.inode); 3870 if (retval) 3871 return retval; 3872 retval = dquot_initialize(new.dir); 3873 if (retval) 3874 return retval; 3875 3876 /* Initialize quotas before so that eventual writes go 3877 * in separate transaction */ 3878 if (new.inode) { 3879 retval = dquot_initialize(new.inode); 3880 if (retval) 3881 return retval; 3882 } 3883 3884 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, 3885 &old.inlined); 3886 if (IS_ERR(old.bh)) 3887 return PTR_ERR(old.bh); 3888 3889 /* 3890 * Check for inode number is _not_ due to possible IO errors. 3891 * We might rmdir the source, keep it as pwd of some process 3892 * and merrily kill the link to whatever was created under the 3893 * same name. Goodbye sticky bit ;-< 3894 */ 3895 retval = -ENOENT; 3896 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino) 3897 goto release_bh; 3898 3899 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, 3900 &new.de, &new.inlined); 3901 if (IS_ERR(new.bh)) { 3902 retval = PTR_ERR(new.bh); 3903 new.bh = NULL; 3904 goto release_bh; 3905 } 3906 if (new.bh) { 3907 if (!new.inode) { 3908 brelse(new.bh); 3909 new.bh = NULL; 3910 } 3911 } 3912 if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC)) 3913 ext4_alloc_da_blocks(old.inode); 3914 3915 credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + 3916 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2); 3917 if (!(flags & RENAME_WHITEOUT)) { 3918 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits); 3919 if (IS_ERR(handle)) { 3920 retval = PTR_ERR(handle); 3921 goto release_bh; 3922 } 3923 } else { 3924 whiteout = ext4_whiteout_for_rename(idmap, &old, credits, &handle); 3925 if (IS_ERR(whiteout)) { 3926 retval = PTR_ERR(whiteout); 3927 goto release_bh; 3928 } 3929 } 3930 3931 old_file_type = old.de->file_type; 3932 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir)) 3933 ext4_handle_sync(handle); 3934 3935 if (S_ISDIR(old.inode->i_mode)) { 3936 if (new.inode) { 3937 retval = -ENOTEMPTY; 3938 if (!ext4_empty_dir(new.inode)) 3939 goto end_rename; 3940 } else { 3941 retval = -EMLINK; 3942 if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir)) 3943 goto end_rename; 3944 } 3945 retval = ext4_rename_dir_prepare(handle, &old); 3946 if (retval) 3947 goto end_rename; 3948 } 3949 /* 3950 * If we're renaming a file within an inline_data dir and adding or 3951 * setting the new dirent causes a conversion from inline_data to 3952 * extents/blockmap, we need to force the dirent delete code to 3953 * re-read the directory, or else we end up trying to delete a dirent 3954 * from what is now the extent tree root (or a block map). 3955 */ 3956 force_reread = (new.dir->i_ino == old.dir->i_ino && 3957 ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA)); 3958 3959 if (whiteout) { 3960 /* 3961 * Do this before adding a new entry, so the old entry is sure 3962 * to be still pointing to the valid old entry. 3963 */ 3964 retval = ext4_setent(handle, &old, whiteout->i_ino, 3965 EXT4_FT_CHRDEV); 3966 if (retval) 3967 goto end_rename; 3968 retval = ext4_mark_inode_dirty(handle, whiteout); 3969 if (unlikely(retval)) 3970 goto end_rename; 3971 3972 } 3973 if (!new.bh) { 3974 retval = ext4_add_entry(handle, new.dentry, old.inode); 3975 if (retval) 3976 goto end_rename; 3977 } else { 3978 retval = ext4_setent(handle, &new, 3979 old.inode->i_ino, old_file_type); 3980 if (retval) 3981 goto end_rename; 3982 } 3983 if (force_reread) 3984 force_reread = !ext4_test_inode_flag(new.dir, 3985 EXT4_INODE_INLINE_DATA); 3986 3987 /* 3988 * Like most other Unix systems, set the ctime for inodes on a 3989 * rename. 3990 */ 3991 inode_set_ctime_current(old.inode); 3992 retval = ext4_mark_inode_dirty(handle, old.inode); 3993 if (unlikely(retval)) 3994 goto end_rename; 3995 3996 if (!whiteout) { 3997 /* 3998 * ok, that's it 3999 */ 4000 ext4_rename_delete(handle, &old, force_reread); 4001 } 4002 4003 if (new.inode) { 4004 ext4_dec_count(new.inode); 4005 inode_set_ctime_current(new.inode); 4006 } 4007 old.dir->i_mtime = inode_set_ctime_current(old.dir); 4008 ext4_update_dx_flag(old.dir); 4009 if (old.dir_bh) { 4010 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); 4011 if (retval) 4012 goto end_rename; 4013 4014 ext4_dec_count(old.dir); 4015 if (new.inode) { 4016 /* checked ext4_empty_dir above, can't have another 4017 * parent, ext4_dec_count() won't work for many-linked 4018 * dirs */ 4019 clear_nlink(new.inode); 4020 } else { 4021 ext4_inc_count(new.dir); 4022 ext4_update_dx_flag(new.dir); 4023 retval = ext4_mark_inode_dirty(handle, new.dir); 4024 if (unlikely(retval)) 4025 goto end_rename; 4026 } 4027 } 4028 retval = ext4_mark_inode_dirty(handle, old.dir); 4029 if (unlikely(retval)) 4030 goto end_rename; 4031 4032 if (S_ISDIR(old.inode->i_mode)) { 4033 /* 4034 * We disable fast commits here that's because the 4035 * replay code is not yet capable of changing dot dot 4036 * dirents in directories. 4037 */ 4038 ext4_fc_mark_ineligible(old.inode->i_sb, 4039 EXT4_FC_REASON_RENAME_DIR, handle); 4040 } else { 4041 struct super_block *sb = old.inode->i_sb; 4042 4043 if (new.inode) 4044 ext4_fc_track_unlink(handle, new.dentry); 4045 if (test_opt2(sb, JOURNAL_FAST_COMMIT) && 4046 !(EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY) && 4047 !(ext4_test_mount_flag(sb, EXT4_MF_FC_INELIGIBLE))) { 4048 __ext4_fc_track_link(handle, old.inode, new.dentry); 4049 __ext4_fc_track_unlink(handle, old.inode, old.dentry); 4050 if (whiteout) 4051 __ext4_fc_track_create(handle, whiteout, 4052 old.dentry); 4053 } 4054 } 4055 4056 if (new.inode) { 4057 retval = ext4_mark_inode_dirty(handle, new.inode); 4058 if (unlikely(retval)) 4059 goto end_rename; 4060 if (!new.inode->i_nlink) 4061 ext4_orphan_add(handle, new.inode); 4062 } 4063 retval = 0; 4064 4065 end_rename: 4066 if (whiteout) { 4067 if (retval) { 4068 ext4_resetent(handle, &old, 4069 old.inode->i_ino, old_file_type); 4070 drop_nlink(whiteout); 4071 ext4_mark_inode_dirty(handle, whiteout); 4072 ext4_orphan_add(handle, whiteout); 4073 } 4074 unlock_new_inode(whiteout); 4075 ext4_journal_stop(handle); 4076 iput(whiteout); 4077 } else { 4078 ext4_journal_stop(handle); 4079 } 4080 release_bh: 4081 brelse(old.dir_bh); 4082 brelse(old.bh); 4083 brelse(new.bh); 4084 4085 return retval; 4086 } 4087 4088 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry, 4089 struct inode *new_dir, struct dentry *new_dentry) 4090 { 4091 handle_t *handle = NULL; 4092 struct ext4_renament old = { 4093 .dir = old_dir, 4094 .dentry = old_dentry, 4095 .inode = d_inode(old_dentry), 4096 }; 4097 struct ext4_renament new = { 4098 .dir = new_dir, 4099 .dentry = new_dentry, 4100 .inode = d_inode(new_dentry), 4101 }; 4102 u8 new_file_type; 4103 int retval; 4104 4105 if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) && 4106 !projid_eq(EXT4_I(new_dir)->i_projid, 4107 EXT4_I(old_dentry->d_inode)->i_projid)) || 4108 (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) && 4109 !projid_eq(EXT4_I(old_dir)->i_projid, 4110 EXT4_I(new_dentry->d_inode)->i_projid))) 4111 return -EXDEV; 4112 4113 retval = dquot_initialize(old.dir); 4114 if (retval) 4115 return retval; 4116 retval = dquot_initialize(new.dir); 4117 if (retval) 4118 return retval; 4119 4120 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, 4121 &old.de, &old.inlined); 4122 if (IS_ERR(old.bh)) 4123 return PTR_ERR(old.bh); 4124 /* 4125 * Check for inode number is _not_ due to possible IO errors. 4126 * We might rmdir the source, keep it as pwd of some process 4127 * and merrily kill the link to whatever was created under the 4128 * same name. Goodbye sticky bit ;-< 4129 */ 4130 retval = -ENOENT; 4131 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino) 4132 goto end_rename; 4133 4134 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, 4135 &new.de, &new.inlined); 4136 if (IS_ERR(new.bh)) { 4137 retval = PTR_ERR(new.bh); 4138 new.bh = NULL; 4139 goto end_rename; 4140 } 4141 4142 /* RENAME_EXCHANGE case: old *and* new must both exist */ 4143 if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino) 4144 goto end_rename; 4145 4146 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, 4147 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + 4148 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2)); 4149 if (IS_ERR(handle)) { 4150 retval = PTR_ERR(handle); 4151 handle = NULL; 4152 goto end_rename; 4153 } 4154 4155 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir)) 4156 ext4_handle_sync(handle); 4157 4158 if (S_ISDIR(old.inode->i_mode)) { 4159 old.is_dir = true; 4160 retval = ext4_rename_dir_prepare(handle, &old); 4161 if (retval) 4162 goto end_rename; 4163 } 4164 if (S_ISDIR(new.inode->i_mode)) { 4165 new.is_dir = true; 4166 retval = ext4_rename_dir_prepare(handle, &new); 4167 if (retval) 4168 goto end_rename; 4169 } 4170 4171 /* 4172 * Other than the special case of overwriting a directory, parents' 4173 * nlink only needs to be modified if this is a cross directory rename. 4174 */ 4175 if (old.dir != new.dir && old.is_dir != new.is_dir) { 4176 old.dir_nlink_delta = old.is_dir ? -1 : 1; 4177 new.dir_nlink_delta = -old.dir_nlink_delta; 4178 retval = -EMLINK; 4179 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) || 4180 (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir))) 4181 goto end_rename; 4182 } 4183 4184 new_file_type = new.de->file_type; 4185 retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type); 4186 if (retval) 4187 goto end_rename; 4188 4189 retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type); 4190 if (retval) 4191 goto end_rename; 4192 4193 /* 4194 * Like most other Unix systems, set the ctime for inodes on a 4195 * rename. 4196 */ 4197 inode_set_ctime_current(old.inode); 4198 inode_set_ctime_current(new.inode); 4199 retval = ext4_mark_inode_dirty(handle, old.inode); 4200 if (unlikely(retval)) 4201 goto end_rename; 4202 retval = ext4_mark_inode_dirty(handle, new.inode); 4203 if (unlikely(retval)) 4204 goto end_rename; 4205 ext4_fc_mark_ineligible(new.inode->i_sb, 4206 EXT4_FC_REASON_CROSS_RENAME, handle); 4207 if (old.dir_bh) { 4208 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); 4209 if (retval) 4210 goto end_rename; 4211 } 4212 if (new.dir_bh) { 4213 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino); 4214 if (retval) 4215 goto end_rename; 4216 } 4217 ext4_update_dir_count(handle, &old); 4218 ext4_update_dir_count(handle, &new); 4219 retval = 0; 4220 4221 end_rename: 4222 brelse(old.dir_bh); 4223 brelse(new.dir_bh); 4224 brelse(old.bh); 4225 brelse(new.bh); 4226 if (handle) 4227 ext4_journal_stop(handle); 4228 return retval; 4229 } 4230 4231 static int ext4_rename2(struct mnt_idmap *idmap, 4232 struct inode *old_dir, struct dentry *old_dentry, 4233 struct inode *new_dir, struct dentry *new_dentry, 4234 unsigned int flags) 4235 { 4236 int err; 4237 4238 if (unlikely(ext4_forced_shutdown(old_dir->i_sb))) 4239 return -EIO; 4240 4241 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT)) 4242 return -EINVAL; 4243 4244 err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry, 4245 flags); 4246 if (err) 4247 return err; 4248 4249 if (flags & RENAME_EXCHANGE) { 4250 return ext4_cross_rename(old_dir, old_dentry, 4251 new_dir, new_dentry); 4252 } 4253 4254 return ext4_rename(idmap, old_dir, old_dentry, new_dir, new_dentry, flags); 4255 } 4256 4257 /* 4258 * directories can handle most operations... 4259 */ 4260 const struct inode_operations ext4_dir_inode_operations = { 4261 .create = ext4_create, 4262 .lookup = ext4_lookup, 4263 .link = ext4_link, 4264 .unlink = ext4_unlink, 4265 .symlink = ext4_symlink, 4266 .mkdir = ext4_mkdir, 4267 .rmdir = ext4_rmdir, 4268 .mknod = ext4_mknod, 4269 .tmpfile = ext4_tmpfile, 4270 .rename = ext4_rename2, 4271 .setattr = ext4_setattr, 4272 .getattr = ext4_getattr, 4273 .listxattr = ext4_listxattr, 4274 .get_inode_acl = ext4_get_acl, 4275 .set_acl = ext4_set_acl, 4276 .fiemap = ext4_fiemap, 4277 .fileattr_get = ext4_fileattr_get, 4278 .fileattr_set = ext4_fileattr_set, 4279 }; 4280 4281 const struct inode_operations ext4_special_inode_operations = { 4282 .setattr = ext4_setattr, 4283 .getattr = ext4_getattr, 4284 .listxattr = ext4_listxattr, 4285 .get_inode_acl = ext4_get_acl, 4286 .set_acl = ext4_set_acl, 4287 }; 4288