1 /* 2 * linux/fs/ext4/namei.c 3 * 4 * Copyright (C) 1992, 1993, 1994, 1995 5 * Remy Card (card@masi.ibp.fr) 6 * Laboratoire MASI - Institut Blaise Pascal 7 * Universite Pierre et Marie Curie (Paris VI) 8 * 9 * from 10 * 11 * linux/fs/minix/namei.c 12 * 13 * Copyright (C) 1991, 1992 Linus Torvalds 14 * 15 * Big-endian to little-endian byte-swapping/bitmaps by 16 * David S. Miller (davem@caip.rutgers.edu), 1995 17 * Directory entry file type support and forward compatibility hooks 18 * for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998 19 * Hash Tree Directory indexing (c) 20 * Daniel Phillips, 2001 21 * Hash Tree Directory indexing porting 22 * Christopher Li, 2002 23 * Hash Tree Directory indexing cleanup 24 * Theodore Ts'o, 2002 25 */ 26 27 #include <linux/fs.h> 28 #include <linux/pagemap.h> 29 #include <linux/time.h> 30 #include <linux/fcntl.h> 31 #include <linux/stat.h> 32 #include <linux/string.h> 33 #include <linux/quotaops.h> 34 #include <linux/buffer_head.h> 35 #include <linux/bio.h> 36 #include "ext4.h" 37 #include "ext4_jbd2.h" 38 39 #include "xattr.h" 40 #include "acl.h" 41 42 #include <trace/events/ext4.h> 43 /* 44 * define how far ahead to read directories while searching them. 45 */ 46 #define NAMEI_RA_CHUNKS 2 47 #define NAMEI_RA_BLOCKS 4 48 #define NAMEI_RA_SIZE (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS) 49 50 static struct buffer_head *ext4_append(handle_t *handle, 51 struct inode *inode, 52 ext4_lblk_t *block) 53 { 54 struct buffer_head *bh; 55 int err; 56 57 if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb && 58 ((inode->i_size >> 10) >= 59 EXT4_SB(inode->i_sb)->s_max_dir_size_kb))) 60 return ERR_PTR(-ENOSPC); 61 62 *block = inode->i_size >> inode->i_sb->s_blocksize_bits; 63 64 bh = ext4_bread(handle, inode, *block, 1); 65 if (IS_ERR(bh)) 66 return bh; 67 inode->i_size += inode->i_sb->s_blocksize; 68 EXT4_I(inode)->i_disksize = inode->i_size; 69 BUFFER_TRACE(bh, "get_write_access"); 70 err = ext4_journal_get_write_access(handle, bh); 71 if (err) { 72 brelse(bh); 73 ext4_std_error(inode->i_sb, err); 74 return ERR_PTR(err); 75 } 76 return bh; 77 } 78 79 static int ext4_dx_csum_verify(struct inode *inode, 80 struct ext4_dir_entry *dirent); 81 82 typedef enum { 83 EITHER, INDEX, DIRENT 84 } dirblock_type_t; 85 86 #define ext4_read_dirblock(inode, block, type) \ 87 __ext4_read_dirblock((inode), (block), (type), __LINE__) 88 89 static struct buffer_head *__ext4_read_dirblock(struct inode *inode, 90 ext4_lblk_t block, 91 dirblock_type_t type, 92 unsigned int line) 93 { 94 struct buffer_head *bh; 95 struct ext4_dir_entry *dirent; 96 int is_dx_block = 0; 97 98 bh = ext4_bread(NULL, inode, block, 0); 99 if (IS_ERR(bh)) { 100 __ext4_warning(inode->i_sb, __func__, line, 101 "error %ld reading directory block " 102 "(ino %lu, block %lu)", PTR_ERR(bh), inode->i_ino, 103 (unsigned long) block); 104 105 return bh; 106 } 107 if (!bh) { 108 ext4_error_inode(inode, __func__, line, block, "Directory hole found"); 109 return ERR_PTR(-EIO); 110 } 111 dirent = (struct ext4_dir_entry *) bh->b_data; 112 /* Determine whether or not we have an index block */ 113 if (is_dx(inode)) { 114 if (block == 0) 115 is_dx_block = 1; 116 else if (ext4_rec_len_from_disk(dirent->rec_len, 117 inode->i_sb->s_blocksize) == 118 inode->i_sb->s_blocksize) 119 is_dx_block = 1; 120 } 121 if (!is_dx_block && type == INDEX) { 122 ext4_error_inode(inode, __func__, line, block, 123 "directory leaf block found instead of index block"); 124 return ERR_PTR(-EIO); 125 } 126 if (!ext4_has_metadata_csum(inode->i_sb) || 127 buffer_verified(bh)) 128 return bh; 129 130 /* 131 * An empty leaf block can get mistaken for a index block; for 132 * this reason, we can only check the index checksum when the 133 * caller is sure it should be an index block. 134 */ 135 if (is_dx_block && type == INDEX) { 136 if (ext4_dx_csum_verify(inode, dirent)) 137 set_buffer_verified(bh); 138 else { 139 ext4_error_inode(inode, __func__, line, block, 140 "Directory index failed checksum"); 141 brelse(bh); 142 return ERR_PTR(-EIO); 143 } 144 } 145 if (!is_dx_block) { 146 if (ext4_dirent_csum_verify(inode, dirent)) 147 set_buffer_verified(bh); 148 else { 149 ext4_error_inode(inode, __func__, line, block, 150 "Directory block failed checksum"); 151 brelse(bh); 152 return ERR_PTR(-EIO); 153 } 154 } 155 return bh; 156 } 157 158 #ifndef assert 159 #define assert(test) J_ASSERT(test) 160 #endif 161 162 #ifdef DX_DEBUG 163 #define dxtrace(command) command 164 #else 165 #define dxtrace(command) 166 #endif 167 168 struct fake_dirent 169 { 170 __le32 inode; 171 __le16 rec_len; 172 u8 name_len; 173 u8 file_type; 174 }; 175 176 struct dx_countlimit 177 { 178 __le16 limit; 179 __le16 count; 180 }; 181 182 struct dx_entry 183 { 184 __le32 hash; 185 __le32 block; 186 }; 187 188 /* 189 * dx_root_info is laid out so that if it should somehow get overlaid by a 190 * dirent the two low bits of the hash version will be zero. Therefore, the 191 * hash version mod 4 should never be 0. Sincerely, the paranoia department. 192 */ 193 194 struct dx_root 195 { 196 struct fake_dirent dot; 197 char dot_name[4]; 198 struct fake_dirent dotdot; 199 char dotdot_name[4]; 200 struct dx_root_info 201 { 202 __le32 reserved_zero; 203 u8 hash_version; 204 u8 info_length; /* 8 */ 205 u8 indirect_levels; 206 u8 unused_flags; 207 } 208 info; 209 struct dx_entry entries[0]; 210 }; 211 212 struct dx_node 213 { 214 struct fake_dirent fake; 215 struct dx_entry entries[0]; 216 }; 217 218 219 struct dx_frame 220 { 221 struct buffer_head *bh; 222 struct dx_entry *entries; 223 struct dx_entry *at; 224 }; 225 226 struct dx_map_entry 227 { 228 u32 hash; 229 u16 offs; 230 u16 size; 231 }; 232 233 /* 234 * This goes at the end of each htree block. 235 */ 236 struct dx_tail { 237 u32 dt_reserved; 238 __le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */ 239 }; 240 241 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry); 242 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value); 243 static inline unsigned dx_get_hash(struct dx_entry *entry); 244 static void dx_set_hash(struct dx_entry *entry, unsigned value); 245 static unsigned dx_get_count(struct dx_entry *entries); 246 static unsigned dx_get_limit(struct dx_entry *entries); 247 static void dx_set_count(struct dx_entry *entries, unsigned value); 248 static void dx_set_limit(struct dx_entry *entries, unsigned value); 249 static unsigned dx_root_limit(struct inode *dir, unsigned infosize); 250 static unsigned dx_node_limit(struct inode *dir); 251 static struct dx_frame *dx_probe(const struct qstr *d_name, 252 struct inode *dir, 253 struct dx_hash_info *hinfo, 254 struct dx_frame *frame); 255 static void dx_release(struct dx_frame *frames); 256 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de, 257 unsigned blocksize, struct dx_hash_info *hinfo, 258 struct dx_map_entry map[]); 259 static void dx_sort_map(struct dx_map_entry *map, unsigned count); 260 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to, 261 struct dx_map_entry *offsets, int count, unsigned blocksize); 262 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize); 263 static void dx_insert_block(struct dx_frame *frame, 264 u32 hash, ext4_lblk_t block); 265 static int ext4_htree_next_block(struct inode *dir, __u32 hash, 266 struct dx_frame *frame, 267 struct dx_frame *frames, 268 __u32 *start_hash); 269 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, 270 const struct qstr *d_name, 271 struct ext4_dir_entry_2 **res_dir); 272 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry, 273 struct inode *inode); 274 275 /* checksumming functions */ 276 void initialize_dirent_tail(struct ext4_dir_entry_tail *t, 277 unsigned int blocksize) 278 { 279 memset(t, 0, sizeof(struct ext4_dir_entry_tail)); 280 t->det_rec_len = ext4_rec_len_to_disk( 281 sizeof(struct ext4_dir_entry_tail), blocksize); 282 t->det_reserved_ft = EXT4_FT_DIR_CSUM; 283 } 284 285 /* Walk through a dirent block to find a checksum "dirent" at the tail */ 286 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode, 287 struct ext4_dir_entry *de) 288 { 289 struct ext4_dir_entry_tail *t; 290 291 #ifdef PARANOID 292 struct ext4_dir_entry *d, *top; 293 294 d = de; 295 top = (struct ext4_dir_entry *)(((void *)de) + 296 (EXT4_BLOCK_SIZE(inode->i_sb) - 297 sizeof(struct ext4_dir_entry_tail))); 298 while (d < top && d->rec_len) 299 d = (struct ext4_dir_entry *)(((void *)d) + 300 le16_to_cpu(d->rec_len)); 301 302 if (d != top) 303 return NULL; 304 305 t = (struct ext4_dir_entry_tail *)d; 306 #else 307 t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb)); 308 #endif 309 310 if (t->det_reserved_zero1 || 311 le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) || 312 t->det_reserved_zero2 || 313 t->det_reserved_ft != EXT4_FT_DIR_CSUM) 314 return NULL; 315 316 return t; 317 } 318 319 static __le32 ext4_dirent_csum(struct inode *inode, 320 struct ext4_dir_entry *dirent, int size) 321 { 322 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 323 struct ext4_inode_info *ei = EXT4_I(inode); 324 __u32 csum; 325 326 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size); 327 return cpu_to_le32(csum); 328 } 329 330 static void warn_no_space_for_csum(struct inode *inode) 331 { 332 ext4_warning(inode->i_sb, "no space in directory inode %lu leaf for " 333 "checksum. Please run e2fsck -D.", inode->i_ino); 334 } 335 336 int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent) 337 { 338 struct ext4_dir_entry_tail *t; 339 340 if (!ext4_has_metadata_csum(inode->i_sb)) 341 return 1; 342 343 t = get_dirent_tail(inode, dirent); 344 if (!t) { 345 warn_no_space_for_csum(inode); 346 return 0; 347 } 348 349 if (t->det_checksum != ext4_dirent_csum(inode, dirent, 350 (void *)t - (void *)dirent)) 351 return 0; 352 353 return 1; 354 } 355 356 static void ext4_dirent_csum_set(struct inode *inode, 357 struct ext4_dir_entry *dirent) 358 { 359 struct ext4_dir_entry_tail *t; 360 361 if (!ext4_has_metadata_csum(inode->i_sb)) 362 return; 363 364 t = get_dirent_tail(inode, dirent); 365 if (!t) { 366 warn_no_space_for_csum(inode); 367 return; 368 } 369 370 t->det_checksum = ext4_dirent_csum(inode, dirent, 371 (void *)t - (void *)dirent); 372 } 373 374 int ext4_handle_dirty_dirent_node(handle_t *handle, 375 struct inode *inode, 376 struct buffer_head *bh) 377 { 378 ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data); 379 return ext4_handle_dirty_metadata(handle, inode, bh); 380 } 381 382 static struct dx_countlimit *get_dx_countlimit(struct inode *inode, 383 struct ext4_dir_entry *dirent, 384 int *offset) 385 { 386 struct ext4_dir_entry *dp; 387 struct dx_root_info *root; 388 int count_offset; 389 390 if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb)) 391 count_offset = 8; 392 else if (le16_to_cpu(dirent->rec_len) == 12) { 393 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12); 394 if (le16_to_cpu(dp->rec_len) != 395 EXT4_BLOCK_SIZE(inode->i_sb) - 12) 396 return NULL; 397 root = (struct dx_root_info *)(((void *)dp + 12)); 398 if (root->reserved_zero || 399 root->info_length != sizeof(struct dx_root_info)) 400 return NULL; 401 count_offset = 32; 402 } else 403 return NULL; 404 405 if (offset) 406 *offset = count_offset; 407 return (struct dx_countlimit *)(((void *)dirent) + count_offset); 408 } 409 410 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent, 411 int count_offset, int count, struct dx_tail *t) 412 { 413 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 414 struct ext4_inode_info *ei = EXT4_I(inode); 415 __u32 csum; 416 __le32 save_csum; 417 int size; 418 419 size = count_offset + (count * sizeof(struct dx_entry)); 420 save_csum = t->dt_checksum; 421 t->dt_checksum = 0; 422 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size); 423 csum = ext4_chksum(sbi, csum, (__u8 *)t, sizeof(struct dx_tail)); 424 t->dt_checksum = save_csum; 425 426 return cpu_to_le32(csum); 427 } 428 429 static int ext4_dx_csum_verify(struct inode *inode, 430 struct ext4_dir_entry *dirent) 431 { 432 struct dx_countlimit *c; 433 struct dx_tail *t; 434 int count_offset, limit, count; 435 436 if (!ext4_has_metadata_csum(inode->i_sb)) 437 return 1; 438 439 c = get_dx_countlimit(inode, dirent, &count_offset); 440 if (!c) { 441 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D."); 442 return 1; 443 } 444 limit = le16_to_cpu(c->limit); 445 count = le16_to_cpu(c->count); 446 if (count_offset + (limit * sizeof(struct dx_entry)) > 447 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) { 448 warn_no_space_for_csum(inode); 449 return 1; 450 } 451 t = (struct dx_tail *)(((struct dx_entry *)c) + limit); 452 453 if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset, 454 count, t)) 455 return 0; 456 return 1; 457 } 458 459 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent) 460 { 461 struct dx_countlimit *c; 462 struct dx_tail *t; 463 int count_offset, limit, count; 464 465 if (!ext4_has_metadata_csum(inode->i_sb)) 466 return; 467 468 c = get_dx_countlimit(inode, dirent, &count_offset); 469 if (!c) { 470 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D."); 471 return; 472 } 473 limit = le16_to_cpu(c->limit); 474 count = le16_to_cpu(c->count); 475 if (count_offset + (limit * sizeof(struct dx_entry)) > 476 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) { 477 warn_no_space_for_csum(inode); 478 return; 479 } 480 t = (struct dx_tail *)(((struct dx_entry *)c) + limit); 481 482 t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t); 483 } 484 485 static inline int ext4_handle_dirty_dx_node(handle_t *handle, 486 struct inode *inode, 487 struct buffer_head *bh) 488 { 489 ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data); 490 return ext4_handle_dirty_metadata(handle, inode, bh); 491 } 492 493 /* 494 * p is at least 6 bytes before the end of page 495 */ 496 static inline struct ext4_dir_entry_2 * 497 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize) 498 { 499 return (struct ext4_dir_entry_2 *)((char *)p + 500 ext4_rec_len_from_disk(p->rec_len, blocksize)); 501 } 502 503 /* 504 * Future: use high four bits of block for coalesce-on-delete flags 505 * Mask them off for now. 506 */ 507 508 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry) 509 { 510 return le32_to_cpu(entry->block) & 0x00ffffff; 511 } 512 513 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value) 514 { 515 entry->block = cpu_to_le32(value); 516 } 517 518 static inline unsigned dx_get_hash(struct dx_entry *entry) 519 { 520 return le32_to_cpu(entry->hash); 521 } 522 523 static inline void dx_set_hash(struct dx_entry *entry, unsigned value) 524 { 525 entry->hash = cpu_to_le32(value); 526 } 527 528 static inline unsigned dx_get_count(struct dx_entry *entries) 529 { 530 return le16_to_cpu(((struct dx_countlimit *) entries)->count); 531 } 532 533 static inline unsigned dx_get_limit(struct dx_entry *entries) 534 { 535 return le16_to_cpu(((struct dx_countlimit *) entries)->limit); 536 } 537 538 static inline void dx_set_count(struct dx_entry *entries, unsigned value) 539 { 540 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value); 541 } 542 543 static inline void dx_set_limit(struct dx_entry *entries, unsigned value) 544 { 545 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value); 546 } 547 548 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize) 549 { 550 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) - 551 EXT4_DIR_REC_LEN(2) - infosize; 552 553 if (ext4_has_metadata_csum(dir->i_sb)) 554 entry_space -= sizeof(struct dx_tail); 555 return entry_space / sizeof(struct dx_entry); 556 } 557 558 static inline unsigned dx_node_limit(struct inode *dir) 559 { 560 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0); 561 562 if (ext4_has_metadata_csum(dir->i_sb)) 563 entry_space -= sizeof(struct dx_tail); 564 return entry_space / sizeof(struct dx_entry); 565 } 566 567 /* 568 * Debug 569 */ 570 #ifdef DX_DEBUG 571 static void dx_show_index(char * label, struct dx_entry *entries) 572 { 573 int i, n = dx_get_count (entries); 574 printk(KERN_DEBUG "%s index ", label); 575 for (i = 0; i < n; i++) { 576 printk("%x->%lu ", i ? dx_get_hash(entries + i) : 577 0, (unsigned long)dx_get_block(entries + i)); 578 } 579 printk("\n"); 580 } 581 582 struct stats 583 { 584 unsigned names; 585 unsigned space; 586 unsigned bcount; 587 }; 588 589 static struct stats dx_show_leaf(struct inode *dir, 590 struct dx_hash_info *hinfo, 591 struct ext4_dir_entry_2 *de, 592 int size, int show_names) 593 { 594 unsigned names = 0, space = 0; 595 char *base = (char *) de; 596 struct dx_hash_info h = *hinfo; 597 598 printk("names: "); 599 while ((char *) de < base + size) 600 { 601 if (de->inode) 602 { 603 if (show_names) 604 { 605 #ifdef CONFIG_EXT4_FS_ENCRYPTION 606 int len; 607 char *name; 608 struct ext4_str fname_crypto_str 609 = {.name = NULL, .len = 0}; 610 struct ext4_fname_crypto_ctx *ctx = NULL; 611 int res; 612 613 name = de->name; 614 len = de->name_len; 615 ctx = ext4_get_fname_crypto_ctx(dir, 616 EXT4_NAME_LEN); 617 if (IS_ERR(ctx)) { 618 printk(KERN_WARNING "Error acquiring" 619 " crypto ctxt--skipping crypto\n"); 620 ctx = NULL; 621 } 622 if (ctx == NULL) { 623 /* Directory is not encrypted */ 624 ext4fs_dirhash(de->name, 625 de->name_len, &h); 626 printk("%*.s:(U)%x.%u ", len, 627 name, h.hash, 628 (unsigned) ((char *) de 629 - base)); 630 } else { 631 /* Directory is encrypted */ 632 res = ext4_fname_crypto_alloc_buffer( 633 ctx, de->name_len, 634 &fname_crypto_str); 635 if (res < 0) { 636 printk(KERN_WARNING "Error " 637 "allocating crypto " 638 "buffer--skipping " 639 "crypto\n"); 640 ext4_put_fname_crypto_ctx(&ctx); 641 ctx = NULL; 642 } 643 res = ext4_fname_disk_to_usr(ctx, de, 644 &fname_crypto_str); 645 if (res < 0) { 646 printk(KERN_WARNING "Error " 647 "converting filename " 648 "from disk to usr" 649 "\n"); 650 name = "??"; 651 len = 2; 652 } else { 653 name = fname_crypto_str.name; 654 len = fname_crypto_str.len; 655 } 656 res = ext4_fname_disk_to_hash(ctx, de, 657 &h); 658 if (res < 0) { 659 printk(KERN_WARNING "Error " 660 "converting filename " 661 "from disk to htree" 662 "\n"); 663 h.hash = 0xDEADBEEF; 664 } 665 printk("%*.s:(E)%x.%u ", len, name, 666 h.hash, (unsigned) ((char *) de 667 - base)); 668 ext4_put_fname_crypto_ctx(&ctx); 669 ext4_fname_crypto_free_buffer( 670 &fname_crypto_str); 671 } 672 #else 673 int len = de->name_len; 674 char *name = de->name; 675 ext4fs_dirhash(de->name, de->name_len, &h); 676 printk("%*.s:%x.%u ", len, name, h.hash, 677 (unsigned) ((char *) de - base)); 678 #endif 679 } 680 space += EXT4_DIR_REC_LEN(de->name_len); 681 names++; 682 } 683 de = ext4_next_entry(de, size); 684 } 685 printk("(%i)\n", names); 686 return (struct stats) { names, space, 1 }; 687 } 688 689 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir, 690 struct dx_entry *entries, int levels) 691 { 692 unsigned blocksize = dir->i_sb->s_blocksize; 693 unsigned count = dx_get_count(entries), names = 0, space = 0, i; 694 unsigned bcount = 0; 695 struct buffer_head *bh; 696 printk("%i indexed blocks...\n", count); 697 for (i = 0; i < count; i++, entries++) 698 { 699 ext4_lblk_t block = dx_get_block(entries); 700 ext4_lblk_t hash = i ? dx_get_hash(entries): 0; 701 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash; 702 struct stats stats; 703 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range); 704 bh = ext4_bread(NULL,dir, block, 0); 705 if (!bh || IS_ERR(bh)) 706 continue; 707 stats = levels? 708 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1): 709 dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) 710 bh->b_data, blocksize, 0); 711 names += stats.names; 712 space += stats.space; 713 bcount += stats.bcount; 714 brelse(bh); 715 } 716 if (bcount) 717 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n", 718 levels ? "" : " ", names, space/bcount, 719 (space/bcount)*100/blocksize); 720 return (struct stats) { names, space, bcount}; 721 } 722 #endif /* DX_DEBUG */ 723 724 /* 725 * Probe for a directory leaf block to search. 726 * 727 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format 728 * error in the directory index, and the caller should fall back to 729 * searching the directory normally. The callers of dx_probe **MUST** 730 * check for this error code, and make sure it never gets reflected 731 * back to userspace. 732 */ 733 static struct dx_frame * 734 dx_probe(const struct qstr *d_name, struct inode *dir, 735 struct dx_hash_info *hinfo, struct dx_frame *frame_in) 736 { 737 unsigned count, indirect; 738 struct dx_entry *at, *entries, *p, *q, *m; 739 struct dx_root *root; 740 struct dx_frame *frame = frame_in; 741 struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR); 742 u32 hash; 743 744 frame->bh = ext4_read_dirblock(dir, 0, INDEX); 745 if (IS_ERR(frame->bh)) 746 return (struct dx_frame *) frame->bh; 747 748 root = (struct dx_root *) frame->bh->b_data; 749 if (root->info.hash_version != DX_HASH_TEA && 750 root->info.hash_version != DX_HASH_HALF_MD4 && 751 root->info.hash_version != DX_HASH_LEGACY) { 752 ext4_warning(dir->i_sb, "Unrecognised inode hash code %d", 753 root->info.hash_version); 754 goto fail; 755 } 756 hinfo->hash_version = root->info.hash_version; 757 if (hinfo->hash_version <= DX_HASH_TEA) 758 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; 759 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed; 760 #ifdef CONFIG_EXT4_FS_ENCRYPTION 761 if (d_name) { 762 struct ext4_fname_crypto_ctx *ctx = NULL; 763 int res; 764 765 /* Check if the directory is encrypted */ 766 ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN); 767 if (IS_ERR(ctx)) { 768 ret_err = ERR_PTR(PTR_ERR(ctx)); 769 goto fail; 770 } 771 res = ext4_fname_usr_to_hash(ctx, d_name, hinfo); 772 if (res < 0) { 773 ret_err = ERR_PTR(res); 774 goto fail; 775 } 776 ext4_put_fname_crypto_ctx(&ctx); 777 } 778 #else 779 if (d_name) 780 ext4fs_dirhash(d_name->name, d_name->len, hinfo); 781 #endif 782 hash = hinfo->hash; 783 784 if (root->info.unused_flags & 1) { 785 ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x", 786 root->info.unused_flags); 787 goto fail; 788 } 789 790 if ((indirect = root->info.indirect_levels) > 1) { 791 ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x", 792 root->info.indirect_levels); 793 goto fail; 794 } 795 796 entries = (struct dx_entry *) (((char *)&root->info) + 797 root->info.info_length); 798 799 if (dx_get_limit(entries) != dx_root_limit(dir, 800 root->info.info_length)) { 801 ext4_warning(dir->i_sb, "dx entry: limit != root limit"); 802 goto fail; 803 } 804 805 dxtrace(printk("Look up %x", hash)); 806 while (1) { 807 count = dx_get_count(entries); 808 if (!count || count > dx_get_limit(entries)) { 809 ext4_warning(dir->i_sb, 810 "dx entry: no count or count > limit"); 811 goto fail; 812 } 813 814 p = entries + 1; 815 q = entries + count - 1; 816 while (p <= q) { 817 m = p + (q - p)/2; 818 dxtrace(printk(".")); 819 if (dx_get_hash(m) > hash) 820 q = m - 1; 821 else 822 p = m + 1; 823 } 824 825 if (0) { // linear search cross check 826 unsigned n = count - 1; 827 at = entries; 828 while (n--) 829 { 830 dxtrace(printk(",")); 831 if (dx_get_hash(++at) > hash) 832 { 833 at--; 834 break; 835 } 836 } 837 assert (at == p - 1); 838 } 839 840 at = p - 1; 841 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at))); 842 frame->entries = entries; 843 frame->at = at; 844 if (!indirect--) 845 return frame; 846 frame++; 847 frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX); 848 if (IS_ERR(frame->bh)) { 849 ret_err = (struct dx_frame *) frame->bh; 850 frame->bh = NULL; 851 goto fail; 852 } 853 entries = ((struct dx_node *) frame->bh->b_data)->entries; 854 855 if (dx_get_limit(entries) != dx_node_limit (dir)) { 856 ext4_warning(dir->i_sb, 857 "dx entry: limit != node limit"); 858 goto fail; 859 } 860 } 861 fail: 862 while (frame >= frame_in) { 863 brelse(frame->bh); 864 frame--; 865 } 866 867 if (ret_err == ERR_PTR(ERR_BAD_DX_DIR)) 868 ext4_warning(dir->i_sb, 869 "Corrupt dir inode %lu, running e2fsck is " 870 "recommended.", dir->i_ino); 871 return ret_err; 872 } 873 874 static void dx_release (struct dx_frame *frames) 875 { 876 if (frames[0].bh == NULL) 877 return; 878 879 if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels) 880 brelse(frames[1].bh); 881 brelse(frames[0].bh); 882 } 883 884 /* 885 * This function increments the frame pointer to search the next leaf 886 * block, and reads in the necessary intervening nodes if the search 887 * should be necessary. Whether or not the search is necessary is 888 * controlled by the hash parameter. If the hash value is even, then 889 * the search is only continued if the next block starts with that 890 * hash value. This is used if we are searching for a specific file. 891 * 892 * If the hash value is HASH_NB_ALWAYS, then always go to the next block. 893 * 894 * This function returns 1 if the caller should continue to search, 895 * or 0 if it should not. If there is an error reading one of the 896 * index blocks, it will a negative error code. 897 * 898 * If start_hash is non-null, it will be filled in with the starting 899 * hash of the next page. 900 */ 901 static int ext4_htree_next_block(struct inode *dir, __u32 hash, 902 struct dx_frame *frame, 903 struct dx_frame *frames, 904 __u32 *start_hash) 905 { 906 struct dx_frame *p; 907 struct buffer_head *bh; 908 int num_frames = 0; 909 __u32 bhash; 910 911 p = frame; 912 /* 913 * Find the next leaf page by incrementing the frame pointer. 914 * If we run out of entries in the interior node, loop around and 915 * increment pointer in the parent node. When we break out of 916 * this loop, num_frames indicates the number of interior 917 * nodes need to be read. 918 */ 919 while (1) { 920 if (++(p->at) < p->entries + dx_get_count(p->entries)) 921 break; 922 if (p == frames) 923 return 0; 924 num_frames++; 925 p--; 926 } 927 928 /* 929 * If the hash is 1, then continue only if the next page has a 930 * continuation hash of any value. This is used for readdir 931 * handling. Otherwise, check to see if the hash matches the 932 * desired contiuation hash. If it doesn't, return since 933 * there's no point to read in the successive index pages. 934 */ 935 bhash = dx_get_hash(p->at); 936 if (start_hash) 937 *start_hash = bhash; 938 if ((hash & 1) == 0) { 939 if ((bhash & ~1) != hash) 940 return 0; 941 } 942 /* 943 * If the hash is HASH_NB_ALWAYS, we always go to the next 944 * block so no check is necessary 945 */ 946 while (num_frames--) { 947 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX); 948 if (IS_ERR(bh)) 949 return PTR_ERR(bh); 950 p++; 951 brelse(p->bh); 952 p->bh = bh; 953 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries; 954 } 955 return 1; 956 } 957 958 959 /* 960 * This function fills a red-black tree with information from a 961 * directory block. It returns the number directory entries loaded 962 * into the tree. If there is an error it is returned in err. 963 */ 964 static int htree_dirblock_to_tree(struct file *dir_file, 965 struct inode *dir, ext4_lblk_t block, 966 struct dx_hash_info *hinfo, 967 __u32 start_hash, __u32 start_minor_hash) 968 { 969 struct buffer_head *bh; 970 struct ext4_dir_entry_2 *de, *top; 971 int err = 0, count = 0; 972 struct ext4_fname_crypto_ctx *ctx = NULL; 973 struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}, tmp_str; 974 975 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n", 976 (unsigned long)block)); 977 bh = ext4_read_dirblock(dir, block, DIRENT); 978 if (IS_ERR(bh)) 979 return PTR_ERR(bh); 980 981 de = (struct ext4_dir_entry_2 *) bh->b_data; 982 top = (struct ext4_dir_entry_2 *) ((char *) de + 983 dir->i_sb->s_blocksize - 984 EXT4_DIR_REC_LEN(0)); 985 #ifdef CONFIG_EXT4_FS_ENCRYPTION 986 /* Check if the directory is encrypted */ 987 ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN); 988 if (IS_ERR(ctx)) { 989 err = PTR_ERR(ctx); 990 brelse(bh); 991 return err; 992 } 993 if (ctx != NULL) { 994 err = ext4_fname_crypto_alloc_buffer(ctx, EXT4_NAME_LEN, 995 &fname_crypto_str); 996 if (err < 0) { 997 ext4_put_fname_crypto_ctx(&ctx); 998 brelse(bh); 999 return err; 1000 } 1001 } 1002 #endif 1003 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) { 1004 if (ext4_check_dir_entry(dir, NULL, de, bh, 1005 bh->b_data, bh->b_size, 1006 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb)) 1007 + ((char *)de - bh->b_data))) { 1008 /* silently ignore the rest of the block */ 1009 break; 1010 } 1011 #ifdef CONFIG_EXT4_FS_ENCRYPTION 1012 err = ext4_fname_disk_to_hash(ctx, de, hinfo); 1013 if (err < 0) { 1014 count = err; 1015 goto errout; 1016 } 1017 #else 1018 ext4fs_dirhash(de->name, de->name_len, hinfo); 1019 #endif 1020 if ((hinfo->hash < start_hash) || 1021 ((hinfo->hash == start_hash) && 1022 (hinfo->minor_hash < start_minor_hash))) 1023 continue; 1024 if (de->inode == 0) 1025 continue; 1026 if (ctx == NULL) { 1027 /* Directory is not encrypted */ 1028 tmp_str.name = de->name; 1029 tmp_str.len = de->name_len; 1030 err = ext4_htree_store_dirent(dir_file, 1031 hinfo->hash, hinfo->minor_hash, de, 1032 &tmp_str); 1033 } else { 1034 /* Directory is encrypted */ 1035 err = ext4_fname_disk_to_usr(ctx, de, 1036 &fname_crypto_str); 1037 if (err < 0) { 1038 count = err; 1039 goto errout; 1040 } 1041 err = ext4_htree_store_dirent(dir_file, 1042 hinfo->hash, hinfo->minor_hash, de, 1043 &fname_crypto_str); 1044 } 1045 if (err != 0) { 1046 count = err; 1047 goto errout; 1048 } 1049 count++; 1050 } 1051 errout: 1052 brelse(bh); 1053 #ifdef CONFIG_EXT4_FS_ENCRYPTION 1054 ext4_put_fname_crypto_ctx(&ctx); 1055 ext4_fname_crypto_free_buffer(&fname_crypto_str); 1056 #endif 1057 return count; 1058 } 1059 1060 1061 /* 1062 * This function fills a red-black tree with information from a 1063 * directory. We start scanning the directory in hash order, starting 1064 * at start_hash and start_minor_hash. 1065 * 1066 * This function returns the number of entries inserted into the tree, 1067 * or a negative error code. 1068 */ 1069 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash, 1070 __u32 start_minor_hash, __u32 *next_hash) 1071 { 1072 struct dx_hash_info hinfo; 1073 struct ext4_dir_entry_2 *de; 1074 struct dx_frame frames[2], *frame; 1075 struct inode *dir; 1076 ext4_lblk_t block; 1077 int count = 0; 1078 int ret, err; 1079 __u32 hashval; 1080 struct ext4_str tmp_str; 1081 1082 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n", 1083 start_hash, start_minor_hash)); 1084 dir = file_inode(dir_file); 1085 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) { 1086 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version; 1087 if (hinfo.hash_version <= DX_HASH_TEA) 1088 hinfo.hash_version += 1089 EXT4_SB(dir->i_sb)->s_hash_unsigned; 1090 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; 1091 if (ext4_has_inline_data(dir)) { 1092 int has_inline_data = 1; 1093 count = htree_inlinedir_to_tree(dir_file, dir, 0, 1094 &hinfo, start_hash, 1095 start_minor_hash, 1096 &has_inline_data); 1097 if (has_inline_data) { 1098 *next_hash = ~0; 1099 return count; 1100 } 1101 } 1102 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo, 1103 start_hash, start_minor_hash); 1104 *next_hash = ~0; 1105 return count; 1106 } 1107 hinfo.hash = start_hash; 1108 hinfo.minor_hash = 0; 1109 frame = dx_probe(NULL, dir, &hinfo, frames); 1110 if (IS_ERR(frame)) 1111 return PTR_ERR(frame); 1112 1113 /* Add '.' and '..' from the htree header */ 1114 if (!start_hash && !start_minor_hash) { 1115 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; 1116 tmp_str.name = de->name; 1117 tmp_str.len = de->name_len; 1118 err = ext4_htree_store_dirent(dir_file, 0, 0, 1119 de, &tmp_str); 1120 if (err != 0) 1121 goto errout; 1122 count++; 1123 } 1124 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) { 1125 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; 1126 de = ext4_next_entry(de, dir->i_sb->s_blocksize); 1127 tmp_str.name = de->name; 1128 tmp_str.len = de->name_len; 1129 err = ext4_htree_store_dirent(dir_file, 2, 0, 1130 de, &tmp_str); 1131 if (err != 0) 1132 goto errout; 1133 count++; 1134 } 1135 1136 while (1) { 1137 block = dx_get_block(frame->at); 1138 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo, 1139 start_hash, start_minor_hash); 1140 if (ret < 0) { 1141 err = ret; 1142 goto errout; 1143 } 1144 count += ret; 1145 hashval = ~0; 1146 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS, 1147 frame, frames, &hashval); 1148 *next_hash = hashval; 1149 if (ret < 0) { 1150 err = ret; 1151 goto errout; 1152 } 1153 /* 1154 * Stop if: (a) there are no more entries, or 1155 * (b) we have inserted at least one entry and the 1156 * next hash value is not a continuation 1157 */ 1158 if ((ret == 0) || 1159 (count && ((hashval & 1) == 0))) 1160 break; 1161 } 1162 dx_release(frames); 1163 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, " 1164 "next hash: %x\n", count, *next_hash)); 1165 return count; 1166 errout: 1167 dx_release(frames); 1168 return (err); 1169 } 1170 1171 static inline int search_dirblock(struct buffer_head *bh, 1172 struct inode *dir, 1173 const struct qstr *d_name, 1174 unsigned int offset, 1175 struct ext4_dir_entry_2 **res_dir) 1176 { 1177 return search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir, 1178 d_name, offset, res_dir); 1179 } 1180 1181 /* 1182 * Directory block splitting, compacting 1183 */ 1184 1185 /* 1186 * Create map of hash values, offsets, and sizes, stored at end of block. 1187 * Returns number of entries mapped. 1188 */ 1189 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de, 1190 unsigned blocksize, struct dx_hash_info *hinfo, 1191 struct dx_map_entry *map_tail) 1192 { 1193 int count = 0; 1194 char *base = (char *) de; 1195 struct dx_hash_info h = *hinfo; 1196 #ifdef CONFIG_EXT4_FS_ENCRYPTION 1197 struct ext4_fname_crypto_ctx *ctx = NULL; 1198 int err; 1199 1200 ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN); 1201 if (IS_ERR(ctx)) 1202 return PTR_ERR(ctx); 1203 #endif 1204 1205 while ((char *) de < base + blocksize) { 1206 if (de->name_len && de->inode) { 1207 #ifdef CONFIG_EXT4_FS_ENCRYPTION 1208 err = ext4_fname_disk_to_hash(ctx, de, &h); 1209 if (err < 0) { 1210 ext4_put_fname_crypto_ctx(&ctx); 1211 return err; 1212 } 1213 #else 1214 ext4fs_dirhash(de->name, de->name_len, &h); 1215 #endif 1216 map_tail--; 1217 map_tail->hash = h.hash; 1218 map_tail->offs = ((char *) de - base)>>2; 1219 map_tail->size = le16_to_cpu(de->rec_len); 1220 count++; 1221 cond_resched(); 1222 } 1223 /* XXX: do we need to check rec_len == 0 case? -Chris */ 1224 de = ext4_next_entry(de, blocksize); 1225 } 1226 #ifdef CONFIG_EXT4_FS_ENCRYPTION 1227 ext4_put_fname_crypto_ctx(&ctx); 1228 #endif 1229 return count; 1230 } 1231 1232 /* Sort map by hash value */ 1233 static void dx_sort_map (struct dx_map_entry *map, unsigned count) 1234 { 1235 struct dx_map_entry *p, *q, *top = map + count - 1; 1236 int more; 1237 /* Combsort until bubble sort doesn't suck */ 1238 while (count > 2) { 1239 count = count*10/13; 1240 if (count - 9 < 2) /* 9, 10 -> 11 */ 1241 count = 11; 1242 for (p = top, q = p - count; q >= map; p--, q--) 1243 if (p->hash < q->hash) 1244 swap(*p, *q); 1245 } 1246 /* Garden variety bubble sort */ 1247 do { 1248 more = 0; 1249 q = top; 1250 while (q-- > map) { 1251 if (q[1].hash >= q[0].hash) 1252 continue; 1253 swap(*(q+1), *q); 1254 more = 1; 1255 } 1256 } while(more); 1257 } 1258 1259 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block) 1260 { 1261 struct dx_entry *entries = frame->entries; 1262 struct dx_entry *old = frame->at, *new = old + 1; 1263 int count = dx_get_count(entries); 1264 1265 assert(count < dx_get_limit(entries)); 1266 assert(old < entries + count); 1267 memmove(new + 1, new, (char *)(entries + count) - (char *)(new)); 1268 dx_set_hash(new, hash); 1269 dx_set_block(new, block); 1270 dx_set_count(entries, count + 1); 1271 } 1272 1273 /* 1274 * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure. 1275 * 1276 * `len <= EXT4_NAME_LEN' is guaranteed by caller. 1277 * `de != NULL' is guaranteed by caller. 1278 */ 1279 static inline int ext4_match(struct ext4_fname_crypto_ctx *ctx, 1280 struct ext4_str *fname_crypto_str, 1281 int len, const char * const name, 1282 struct ext4_dir_entry_2 *de) 1283 { 1284 int res; 1285 1286 if (!de->inode) 1287 return 0; 1288 1289 #ifdef CONFIG_EXT4_FS_ENCRYPTION 1290 if (ctx) { 1291 /* Directory is encrypted */ 1292 res = ext4_fname_disk_to_usr(ctx, de, fname_crypto_str); 1293 if (res < 0) 1294 return res; 1295 if (len != res) 1296 return 0; 1297 res = memcmp(name, fname_crypto_str->name, len); 1298 return (res == 0) ? 1 : 0; 1299 } 1300 #endif 1301 if (len != de->name_len) 1302 return 0; 1303 res = memcmp(name, de->name, len); 1304 return (res == 0) ? 1 : 0; 1305 } 1306 1307 /* 1308 * Returns 0 if not found, -1 on failure, and 1 on success 1309 */ 1310 int search_dir(struct buffer_head *bh, char *search_buf, int buf_size, 1311 struct inode *dir, const struct qstr *d_name, 1312 unsigned int offset, struct ext4_dir_entry_2 **res_dir) 1313 { 1314 struct ext4_dir_entry_2 * de; 1315 char * dlimit; 1316 int de_len; 1317 const char *name = d_name->name; 1318 int namelen = d_name->len; 1319 struct ext4_fname_crypto_ctx *ctx = NULL; 1320 struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}; 1321 int res; 1322 1323 ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN); 1324 if (IS_ERR(ctx)) 1325 return -1; 1326 1327 if (ctx != NULL) { 1328 /* Allocate buffer to hold maximum name length */ 1329 res = ext4_fname_crypto_alloc_buffer(ctx, EXT4_NAME_LEN, 1330 &fname_crypto_str); 1331 if (res < 0) { 1332 ext4_put_fname_crypto_ctx(&ctx); 1333 return -1; 1334 } 1335 } 1336 1337 de = (struct ext4_dir_entry_2 *)search_buf; 1338 dlimit = search_buf + buf_size; 1339 while ((char *) de < dlimit) { 1340 /* this code is executed quadratically often */ 1341 /* do minimal checking `by hand' */ 1342 if ((char *) de + de->name_len <= dlimit) { 1343 res = ext4_match(ctx, &fname_crypto_str, namelen, 1344 name, de); 1345 if (res < 0) { 1346 res = -1; 1347 goto return_result; 1348 } 1349 if (res > 0) { 1350 /* found a match - just to be sure, do 1351 * a full check */ 1352 if (ext4_check_dir_entry(dir, NULL, de, bh, 1353 bh->b_data, 1354 bh->b_size, offset)) { 1355 res = -1; 1356 goto return_result; 1357 } 1358 *res_dir = de; 1359 res = 1; 1360 goto return_result; 1361 } 1362 1363 } 1364 /* prevent looping on a bad block */ 1365 de_len = ext4_rec_len_from_disk(de->rec_len, 1366 dir->i_sb->s_blocksize); 1367 if (de_len <= 0) { 1368 res = -1; 1369 goto return_result; 1370 } 1371 offset += de_len; 1372 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len); 1373 } 1374 1375 res = 0; 1376 return_result: 1377 ext4_put_fname_crypto_ctx(&ctx); 1378 ext4_fname_crypto_free_buffer(&fname_crypto_str); 1379 return res; 1380 } 1381 1382 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block, 1383 struct ext4_dir_entry *de) 1384 { 1385 struct super_block *sb = dir->i_sb; 1386 1387 if (!is_dx(dir)) 1388 return 0; 1389 if (block == 0) 1390 return 1; 1391 if (de->inode == 0 && 1392 ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) == 1393 sb->s_blocksize) 1394 return 1; 1395 return 0; 1396 } 1397 1398 /* 1399 * ext4_find_entry() 1400 * 1401 * finds an entry in the specified directory with the wanted name. It 1402 * returns the cache buffer in which the entry was found, and the entry 1403 * itself (as a parameter - res_dir). It does NOT read the inode of the 1404 * entry - you'll have to do that yourself if you want to. 1405 * 1406 * The returned buffer_head has ->b_count elevated. The caller is expected 1407 * to brelse() it when appropriate. 1408 */ 1409 static struct buffer_head * ext4_find_entry (struct inode *dir, 1410 const struct qstr *d_name, 1411 struct ext4_dir_entry_2 **res_dir, 1412 int *inlined) 1413 { 1414 struct super_block *sb; 1415 struct buffer_head *bh_use[NAMEI_RA_SIZE]; 1416 struct buffer_head *bh, *ret = NULL; 1417 ext4_lblk_t start, block, b; 1418 const u8 *name = d_name->name; 1419 int ra_max = 0; /* Number of bh's in the readahead 1420 buffer, bh_use[] */ 1421 int ra_ptr = 0; /* Current index into readahead 1422 buffer */ 1423 int num = 0; 1424 ext4_lblk_t nblocks; 1425 int i, namelen; 1426 1427 *res_dir = NULL; 1428 sb = dir->i_sb; 1429 namelen = d_name->len; 1430 if (namelen > EXT4_NAME_LEN) 1431 return NULL; 1432 1433 if (ext4_has_inline_data(dir)) { 1434 int has_inline_data = 1; 1435 ret = ext4_find_inline_entry(dir, d_name, res_dir, 1436 &has_inline_data); 1437 if (has_inline_data) { 1438 if (inlined) 1439 *inlined = 1; 1440 return ret; 1441 } 1442 } 1443 1444 if ((namelen <= 2) && (name[0] == '.') && 1445 (name[1] == '.' || name[1] == '\0')) { 1446 /* 1447 * "." or ".." will only be in the first block 1448 * NFS may look up ".."; "." should be handled by the VFS 1449 */ 1450 block = start = 0; 1451 nblocks = 1; 1452 goto restart; 1453 } 1454 if (is_dx(dir)) { 1455 bh = ext4_dx_find_entry(dir, d_name, res_dir); 1456 /* 1457 * On success, or if the error was file not found, 1458 * return. Otherwise, fall back to doing a search the 1459 * old fashioned way. 1460 */ 1461 if (!IS_ERR(bh) || PTR_ERR(bh) != ERR_BAD_DX_DIR) 1462 return bh; 1463 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, " 1464 "falling back\n")); 1465 } 1466 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); 1467 start = EXT4_I(dir)->i_dir_start_lookup; 1468 if (start >= nblocks) 1469 start = 0; 1470 block = start; 1471 restart: 1472 do { 1473 /* 1474 * We deal with the read-ahead logic here. 1475 */ 1476 if (ra_ptr >= ra_max) { 1477 /* Refill the readahead buffer */ 1478 ra_ptr = 0; 1479 b = block; 1480 for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) { 1481 /* 1482 * Terminate if we reach the end of the 1483 * directory and must wrap, or if our 1484 * search has finished at this block. 1485 */ 1486 if (b >= nblocks || (num && block == start)) { 1487 bh_use[ra_max] = NULL; 1488 break; 1489 } 1490 num++; 1491 bh = ext4_getblk(NULL, dir, b++, 0); 1492 if (unlikely(IS_ERR(bh))) { 1493 if (ra_max == 0) 1494 return bh; 1495 break; 1496 } 1497 bh_use[ra_max] = bh; 1498 if (bh) 1499 ll_rw_block(READ | REQ_META | REQ_PRIO, 1500 1, &bh); 1501 } 1502 } 1503 if ((bh = bh_use[ra_ptr++]) == NULL) 1504 goto next; 1505 wait_on_buffer(bh); 1506 if (!buffer_uptodate(bh)) { 1507 /* read error, skip block & hope for the best */ 1508 EXT4_ERROR_INODE(dir, "reading directory lblock %lu", 1509 (unsigned long) block); 1510 brelse(bh); 1511 goto next; 1512 } 1513 if (!buffer_verified(bh) && 1514 !is_dx_internal_node(dir, block, 1515 (struct ext4_dir_entry *)bh->b_data) && 1516 !ext4_dirent_csum_verify(dir, 1517 (struct ext4_dir_entry *)bh->b_data)) { 1518 EXT4_ERROR_INODE(dir, "checksumming directory " 1519 "block %lu", (unsigned long)block); 1520 brelse(bh); 1521 goto next; 1522 } 1523 set_buffer_verified(bh); 1524 i = search_dirblock(bh, dir, d_name, 1525 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir); 1526 if (i == 1) { 1527 EXT4_I(dir)->i_dir_start_lookup = block; 1528 ret = bh; 1529 goto cleanup_and_exit; 1530 } else { 1531 brelse(bh); 1532 if (i < 0) 1533 goto cleanup_and_exit; 1534 } 1535 next: 1536 if (++block >= nblocks) 1537 block = 0; 1538 } while (block != start); 1539 1540 /* 1541 * If the directory has grown while we were searching, then 1542 * search the last part of the directory before giving up. 1543 */ 1544 block = nblocks; 1545 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); 1546 if (block < nblocks) { 1547 start = 0; 1548 goto restart; 1549 } 1550 1551 cleanup_and_exit: 1552 /* Clean up the read-ahead blocks */ 1553 for (; ra_ptr < ra_max; ra_ptr++) 1554 brelse(bh_use[ra_ptr]); 1555 return ret; 1556 } 1557 1558 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name, 1559 struct ext4_dir_entry_2 **res_dir) 1560 { 1561 struct super_block * sb = dir->i_sb; 1562 struct dx_hash_info hinfo; 1563 struct dx_frame frames[2], *frame; 1564 struct buffer_head *bh; 1565 ext4_lblk_t block; 1566 int retval; 1567 1568 #ifdef CONFIG_EXT4_FS_ENCRYPTION 1569 *res_dir = NULL; 1570 #endif 1571 frame = dx_probe(d_name, dir, &hinfo, frames); 1572 if (IS_ERR(frame)) 1573 return (struct buffer_head *) frame; 1574 do { 1575 block = dx_get_block(frame->at); 1576 bh = ext4_read_dirblock(dir, block, DIRENT); 1577 if (IS_ERR(bh)) 1578 goto errout; 1579 1580 retval = search_dirblock(bh, dir, d_name, 1581 block << EXT4_BLOCK_SIZE_BITS(sb), 1582 res_dir); 1583 if (retval == 1) 1584 goto success; 1585 brelse(bh); 1586 if (retval == -1) { 1587 bh = ERR_PTR(ERR_BAD_DX_DIR); 1588 goto errout; 1589 } 1590 1591 /* Check to see if we should continue to search */ 1592 retval = ext4_htree_next_block(dir, hinfo.hash, frame, 1593 frames, NULL); 1594 if (retval < 0) { 1595 ext4_warning(sb, 1596 "error %d reading index page in directory #%lu", 1597 retval, dir->i_ino); 1598 bh = ERR_PTR(retval); 1599 goto errout; 1600 } 1601 } while (retval == 1); 1602 1603 bh = NULL; 1604 errout: 1605 dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name)); 1606 success: 1607 dx_release(frames); 1608 return bh; 1609 } 1610 1611 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 1612 { 1613 struct inode *inode; 1614 struct ext4_dir_entry_2 *de; 1615 struct buffer_head *bh; 1616 1617 if (dentry->d_name.len > EXT4_NAME_LEN) 1618 return ERR_PTR(-ENAMETOOLONG); 1619 1620 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); 1621 if (IS_ERR(bh)) 1622 return (struct dentry *) bh; 1623 inode = NULL; 1624 if (bh) { 1625 __u32 ino = le32_to_cpu(de->inode); 1626 brelse(bh); 1627 if (!ext4_valid_inum(dir->i_sb, ino)) { 1628 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino); 1629 return ERR_PTR(-EIO); 1630 } 1631 if (unlikely(ino == dir->i_ino)) { 1632 EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir", 1633 dentry); 1634 return ERR_PTR(-EIO); 1635 } 1636 inode = ext4_iget_normal(dir->i_sb, ino); 1637 if (inode == ERR_PTR(-ESTALE)) { 1638 EXT4_ERROR_INODE(dir, 1639 "deleted inode referenced: %u", 1640 ino); 1641 return ERR_PTR(-EIO); 1642 } 1643 if (!IS_ERR(inode) && ext4_encrypted_inode(dir) && 1644 (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1645 S_ISLNK(inode->i_mode)) && 1646 !ext4_is_child_context_consistent_with_parent(dir, 1647 inode)) { 1648 iput(inode); 1649 ext4_warning(inode->i_sb, 1650 "Inconsistent encryption contexts: %lu/%lu\n", 1651 (unsigned long) dir->i_ino, 1652 (unsigned long) inode->i_ino); 1653 return ERR_PTR(-EPERM); 1654 } 1655 } 1656 return d_splice_alias(inode, dentry); 1657 } 1658 1659 1660 struct dentry *ext4_get_parent(struct dentry *child) 1661 { 1662 __u32 ino; 1663 static const struct qstr dotdot = QSTR_INIT("..", 2); 1664 struct ext4_dir_entry_2 * de; 1665 struct buffer_head *bh; 1666 1667 bh = ext4_find_entry(child->d_inode, &dotdot, &de, NULL); 1668 if (IS_ERR(bh)) 1669 return (struct dentry *) bh; 1670 if (!bh) 1671 return ERR_PTR(-ENOENT); 1672 ino = le32_to_cpu(de->inode); 1673 brelse(bh); 1674 1675 if (!ext4_valid_inum(child->d_inode->i_sb, ino)) { 1676 EXT4_ERROR_INODE(child->d_inode, 1677 "bad parent inode number: %u", ino); 1678 return ERR_PTR(-EIO); 1679 } 1680 1681 return d_obtain_alias(ext4_iget_normal(child->d_inode->i_sb, ino)); 1682 } 1683 1684 /* 1685 * Move count entries from end of map between two memory locations. 1686 * Returns pointer to last entry moved. 1687 */ 1688 static struct ext4_dir_entry_2 * 1689 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count, 1690 unsigned blocksize) 1691 { 1692 unsigned rec_len = 0; 1693 1694 while (count--) { 1695 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) 1696 (from + (map->offs<<2)); 1697 rec_len = EXT4_DIR_REC_LEN(de->name_len); 1698 memcpy (to, de, rec_len); 1699 ((struct ext4_dir_entry_2 *) to)->rec_len = 1700 ext4_rec_len_to_disk(rec_len, blocksize); 1701 de->inode = 0; 1702 map++; 1703 to += rec_len; 1704 } 1705 return (struct ext4_dir_entry_2 *) (to - rec_len); 1706 } 1707 1708 /* 1709 * Compact each dir entry in the range to the minimal rec_len. 1710 * Returns pointer to last entry in range. 1711 */ 1712 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize) 1713 { 1714 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base; 1715 unsigned rec_len = 0; 1716 1717 prev = to = de; 1718 while ((char*)de < base + blocksize) { 1719 next = ext4_next_entry(de, blocksize); 1720 if (de->inode && de->name_len) { 1721 rec_len = EXT4_DIR_REC_LEN(de->name_len); 1722 if (de > to) 1723 memmove(to, de, rec_len); 1724 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize); 1725 prev = to; 1726 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len); 1727 } 1728 de = next; 1729 } 1730 return prev; 1731 } 1732 1733 /* 1734 * Split a full leaf block to make room for a new dir entry. 1735 * Allocate a new block, and move entries so that they are approx. equally full. 1736 * Returns pointer to de in block into which the new entry will be inserted. 1737 */ 1738 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir, 1739 struct buffer_head **bh,struct dx_frame *frame, 1740 struct dx_hash_info *hinfo) 1741 { 1742 unsigned blocksize = dir->i_sb->s_blocksize; 1743 unsigned count, continued; 1744 struct buffer_head *bh2; 1745 ext4_lblk_t newblock; 1746 u32 hash2; 1747 struct dx_map_entry *map; 1748 char *data1 = (*bh)->b_data, *data2; 1749 unsigned split, move, size; 1750 struct ext4_dir_entry_2 *de = NULL, *de2; 1751 struct ext4_dir_entry_tail *t; 1752 int csum_size = 0; 1753 int err = 0, i; 1754 1755 if (ext4_has_metadata_csum(dir->i_sb)) 1756 csum_size = sizeof(struct ext4_dir_entry_tail); 1757 1758 bh2 = ext4_append(handle, dir, &newblock); 1759 if (IS_ERR(bh2)) { 1760 brelse(*bh); 1761 *bh = NULL; 1762 return (struct ext4_dir_entry_2 *) bh2; 1763 } 1764 1765 BUFFER_TRACE(*bh, "get_write_access"); 1766 err = ext4_journal_get_write_access(handle, *bh); 1767 if (err) 1768 goto journal_error; 1769 1770 BUFFER_TRACE(frame->bh, "get_write_access"); 1771 err = ext4_journal_get_write_access(handle, frame->bh); 1772 if (err) 1773 goto journal_error; 1774 1775 data2 = bh2->b_data; 1776 1777 /* create map in the end of data2 block */ 1778 map = (struct dx_map_entry *) (data2 + blocksize); 1779 count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1, 1780 blocksize, hinfo, map); 1781 map -= count; 1782 dx_sort_map(map, count); 1783 /* Split the existing block in the middle, size-wise */ 1784 size = 0; 1785 move = 0; 1786 for (i = count-1; i >= 0; i--) { 1787 /* is more than half of this entry in 2nd half of the block? */ 1788 if (size + map[i].size/2 > blocksize/2) 1789 break; 1790 size += map[i].size; 1791 move++; 1792 } 1793 /* map index at which we will split */ 1794 split = count - move; 1795 hash2 = map[split].hash; 1796 continued = hash2 == map[split - 1].hash; 1797 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n", 1798 (unsigned long)dx_get_block(frame->at), 1799 hash2, split, count-split)); 1800 1801 /* Fancy dance to stay within two buffers */ 1802 de2 = dx_move_dirents(data1, data2, map + split, count - split, 1803 blocksize); 1804 de = dx_pack_dirents(data1, blocksize); 1805 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) - 1806 (char *) de, 1807 blocksize); 1808 de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) - 1809 (char *) de2, 1810 blocksize); 1811 if (csum_size) { 1812 t = EXT4_DIRENT_TAIL(data2, blocksize); 1813 initialize_dirent_tail(t, blocksize); 1814 1815 t = EXT4_DIRENT_TAIL(data1, blocksize); 1816 initialize_dirent_tail(t, blocksize); 1817 } 1818 1819 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1, 1820 blocksize, 1)); 1821 dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2, 1822 blocksize, 1)); 1823 1824 /* Which block gets the new entry? */ 1825 if (hinfo->hash >= hash2) { 1826 swap(*bh, bh2); 1827 de = de2; 1828 } 1829 dx_insert_block(frame, hash2 + continued, newblock); 1830 err = ext4_handle_dirty_dirent_node(handle, dir, bh2); 1831 if (err) 1832 goto journal_error; 1833 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 1834 if (err) 1835 goto journal_error; 1836 brelse(bh2); 1837 dxtrace(dx_show_index("frame", frame->entries)); 1838 return de; 1839 1840 journal_error: 1841 brelse(*bh); 1842 brelse(bh2); 1843 *bh = NULL; 1844 ext4_std_error(dir->i_sb, err); 1845 return ERR_PTR(err); 1846 } 1847 1848 int ext4_find_dest_de(struct inode *dir, struct inode *inode, 1849 struct buffer_head *bh, 1850 void *buf, int buf_size, 1851 const char *name, int namelen, 1852 struct ext4_dir_entry_2 **dest_de) 1853 { 1854 struct ext4_dir_entry_2 *de; 1855 unsigned short reclen = EXT4_DIR_REC_LEN(namelen); 1856 int nlen, rlen; 1857 unsigned int offset = 0; 1858 char *top; 1859 struct ext4_fname_crypto_ctx *ctx = NULL; 1860 struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}; 1861 int res; 1862 1863 ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN); 1864 if (IS_ERR(ctx)) 1865 return -1; 1866 1867 if (ctx != NULL) { 1868 /* Calculate record length needed to store the entry */ 1869 res = ext4_fname_crypto_namelen_on_disk(ctx, namelen); 1870 if (res < 0) { 1871 ext4_put_fname_crypto_ctx(&ctx); 1872 return res; 1873 } 1874 reclen = EXT4_DIR_REC_LEN(res); 1875 1876 /* Allocate buffer to hold maximum name length */ 1877 res = ext4_fname_crypto_alloc_buffer(ctx, EXT4_NAME_LEN, 1878 &fname_crypto_str); 1879 if (res < 0) { 1880 ext4_put_fname_crypto_ctx(&ctx); 1881 return -1; 1882 } 1883 } 1884 1885 de = (struct ext4_dir_entry_2 *)buf; 1886 top = buf + buf_size - reclen; 1887 while ((char *) de <= top) { 1888 if (ext4_check_dir_entry(dir, NULL, de, bh, 1889 buf, buf_size, offset)) { 1890 res = -EIO; 1891 goto return_result; 1892 } 1893 /* Provide crypto context and crypto buffer to ext4 match */ 1894 res = ext4_match(ctx, &fname_crypto_str, namelen, name, de); 1895 if (res < 0) 1896 goto return_result; 1897 if (res > 0) { 1898 res = -EEXIST; 1899 goto return_result; 1900 } 1901 nlen = EXT4_DIR_REC_LEN(de->name_len); 1902 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 1903 if ((de->inode ? rlen - nlen : rlen) >= reclen) 1904 break; 1905 de = (struct ext4_dir_entry_2 *)((char *)de + rlen); 1906 offset += rlen; 1907 } 1908 1909 if ((char *) de > top) 1910 res = -ENOSPC; 1911 else { 1912 *dest_de = de; 1913 res = 0; 1914 } 1915 return_result: 1916 ext4_put_fname_crypto_ctx(&ctx); 1917 ext4_fname_crypto_free_buffer(&fname_crypto_str); 1918 return res; 1919 } 1920 1921 int ext4_insert_dentry(struct inode *dir, 1922 struct inode *inode, 1923 struct ext4_dir_entry_2 *de, 1924 int buf_size, 1925 const struct qstr *iname, 1926 const char *name, int namelen) 1927 { 1928 1929 int nlen, rlen; 1930 struct ext4_fname_crypto_ctx *ctx = NULL; 1931 struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}; 1932 struct ext4_str tmp_str; 1933 int res; 1934 1935 ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN); 1936 if (IS_ERR(ctx)) 1937 return -EIO; 1938 /* By default, the input name would be written to the disk */ 1939 tmp_str.name = (unsigned char *)name; 1940 tmp_str.len = namelen; 1941 if (ctx != NULL) { 1942 /* Directory is encrypted */ 1943 res = ext4_fname_crypto_alloc_buffer(ctx, EXT4_NAME_LEN, 1944 &fname_crypto_str); 1945 if (res < 0) { 1946 ext4_put_fname_crypto_ctx(&ctx); 1947 return -ENOMEM; 1948 } 1949 res = ext4_fname_usr_to_disk(ctx, iname, &fname_crypto_str); 1950 if (res < 0) { 1951 ext4_put_fname_crypto_ctx(&ctx); 1952 ext4_fname_crypto_free_buffer(&fname_crypto_str); 1953 return res; 1954 } 1955 tmp_str.name = fname_crypto_str.name; 1956 tmp_str.len = fname_crypto_str.len; 1957 } 1958 1959 nlen = EXT4_DIR_REC_LEN(de->name_len); 1960 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 1961 if (de->inode) { 1962 struct ext4_dir_entry_2 *de1 = 1963 (struct ext4_dir_entry_2 *)((char *)de + nlen); 1964 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size); 1965 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size); 1966 de = de1; 1967 } 1968 de->file_type = EXT4_FT_UNKNOWN; 1969 de->inode = cpu_to_le32(inode->i_ino); 1970 ext4_set_de_type(inode->i_sb, de, inode->i_mode); 1971 de->name_len = tmp_str.len; 1972 1973 memcpy(de->name, tmp_str.name, tmp_str.len); 1974 ext4_put_fname_crypto_ctx(&ctx); 1975 ext4_fname_crypto_free_buffer(&fname_crypto_str); 1976 return 0; 1977 } 1978 1979 /* 1980 * Add a new entry into a directory (leaf) block. If de is non-NULL, 1981 * it points to a directory entry which is guaranteed to be large 1982 * enough for new directory entry. If de is NULL, then 1983 * add_dirent_to_buf will attempt search the directory block for 1984 * space. It will return -ENOSPC if no space is available, and -EIO 1985 * and -EEXIST if directory entry already exists. 1986 */ 1987 static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry, 1988 struct inode *inode, struct ext4_dir_entry_2 *de, 1989 struct buffer_head *bh) 1990 { 1991 struct inode *dir = dentry->d_parent->d_inode; 1992 const char *name = dentry->d_name.name; 1993 int namelen = dentry->d_name.len; 1994 unsigned int blocksize = dir->i_sb->s_blocksize; 1995 int csum_size = 0; 1996 int err; 1997 1998 if (ext4_has_metadata_csum(inode->i_sb)) 1999 csum_size = sizeof(struct ext4_dir_entry_tail); 2000 2001 if (!de) { 2002 err = ext4_find_dest_de(dir, inode, 2003 bh, bh->b_data, blocksize - csum_size, 2004 name, namelen, &de); 2005 if (err) 2006 return err; 2007 } 2008 BUFFER_TRACE(bh, "get_write_access"); 2009 err = ext4_journal_get_write_access(handle, bh); 2010 if (err) { 2011 ext4_std_error(dir->i_sb, err); 2012 return err; 2013 } 2014 2015 /* By now the buffer is marked for journaling. Due to crypto operations, 2016 * the following function call may fail */ 2017 err = ext4_insert_dentry(dir, inode, de, blocksize, &dentry->d_name, 2018 name, namelen); 2019 if (err < 0) 2020 return err; 2021 2022 /* 2023 * XXX shouldn't update any times until successful 2024 * completion of syscall, but too many callers depend 2025 * on this. 2026 * 2027 * XXX similarly, too many callers depend on 2028 * ext4_new_inode() setting the times, but error 2029 * recovery deletes the inode, so the worst that can 2030 * happen is that the times are slightly out of date 2031 * and/or different from the directory change time. 2032 */ 2033 dir->i_mtime = dir->i_ctime = ext4_current_time(dir); 2034 ext4_update_dx_flag(dir); 2035 dir->i_version++; 2036 ext4_mark_inode_dirty(handle, dir); 2037 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); 2038 err = ext4_handle_dirty_dirent_node(handle, dir, bh); 2039 if (err) 2040 ext4_std_error(dir->i_sb, err); 2041 return 0; 2042 } 2043 2044 /* 2045 * This converts a one block unindexed directory to a 3 block indexed 2046 * directory, and adds the dentry to the indexed directory. 2047 */ 2048 static int make_indexed_dir(handle_t *handle, struct dentry *dentry, 2049 struct inode *inode, struct buffer_head *bh) 2050 { 2051 struct inode *dir = dentry->d_parent->d_inode; 2052 #ifdef CONFIG_EXT4_FS_ENCRYPTION 2053 struct ext4_fname_crypto_ctx *ctx = NULL; 2054 int res; 2055 #else 2056 const char *name = dentry->d_name.name; 2057 int namelen = dentry->d_name.len; 2058 #endif 2059 struct buffer_head *bh2; 2060 struct dx_root *root; 2061 struct dx_frame frames[2], *frame; 2062 struct dx_entry *entries; 2063 struct ext4_dir_entry_2 *de, *de2; 2064 struct ext4_dir_entry_tail *t; 2065 char *data1, *top; 2066 unsigned len; 2067 int retval; 2068 unsigned blocksize; 2069 struct dx_hash_info hinfo; 2070 ext4_lblk_t block; 2071 struct fake_dirent *fde; 2072 int csum_size = 0; 2073 2074 #ifdef CONFIG_EXT4_FS_ENCRYPTION 2075 ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN); 2076 if (IS_ERR(ctx)) 2077 return PTR_ERR(ctx); 2078 #endif 2079 2080 if (ext4_has_metadata_csum(inode->i_sb)) 2081 csum_size = sizeof(struct ext4_dir_entry_tail); 2082 2083 blocksize = dir->i_sb->s_blocksize; 2084 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino)); 2085 BUFFER_TRACE(bh, "get_write_access"); 2086 retval = ext4_journal_get_write_access(handle, bh); 2087 if (retval) { 2088 ext4_std_error(dir->i_sb, retval); 2089 brelse(bh); 2090 return retval; 2091 } 2092 root = (struct dx_root *) bh->b_data; 2093 2094 /* The 0th block becomes the root, move the dirents out */ 2095 fde = &root->dotdot; 2096 de = (struct ext4_dir_entry_2 *)((char *)fde + 2097 ext4_rec_len_from_disk(fde->rec_len, blocksize)); 2098 if ((char *) de >= (((char *) root) + blocksize)) { 2099 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'"); 2100 brelse(bh); 2101 return -EIO; 2102 } 2103 len = ((char *) root) + (blocksize - csum_size) - (char *) de; 2104 2105 /* Allocate new block for the 0th block's dirents */ 2106 bh2 = ext4_append(handle, dir, &block); 2107 if (IS_ERR(bh2)) { 2108 brelse(bh); 2109 return PTR_ERR(bh2); 2110 } 2111 ext4_set_inode_flag(dir, EXT4_INODE_INDEX); 2112 data1 = bh2->b_data; 2113 2114 memcpy (data1, de, len); 2115 de = (struct ext4_dir_entry_2 *) data1; 2116 top = data1 + len; 2117 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top) 2118 de = de2; 2119 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) - 2120 (char *) de, 2121 blocksize); 2122 2123 if (csum_size) { 2124 t = EXT4_DIRENT_TAIL(data1, blocksize); 2125 initialize_dirent_tail(t, blocksize); 2126 } 2127 2128 /* Initialize the root; the dot dirents already exist */ 2129 de = (struct ext4_dir_entry_2 *) (&root->dotdot); 2130 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2), 2131 blocksize); 2132 memset (&root->info, 0, sizeof(root->info)); 2133 root->info.info_length = sizeof(root->info); 2134 root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version; 2135 entries = root->entries; 2136 dx_set_block(entries, 1); 2137 dx_set_count(entries, 1); 2138 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info))); 2139 2140 /* Initialize as for dx_probe */ 2141 hinfo.hash_version = root->info.hash_version; 2142 if (hinfo.hash_version <= DX_HASH_TEA) 2143 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; 2144 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; 2145 #ifdef CONFIG_EXT4_FS_ENCRYPTION 2146 res = ext4_fname_usr_to_hash(ctx, &dentry->d_name, &hinfo); 2147 if (res < 0) { 2148 ext4_put_fname_crypto_ctx(&ctx); 2149 ext4_mark_inode_dirty(handle, dir); 2150 brelse(bh); 2151 return res; 2152 } 2153 ext4_put_fname_crypto_ctx(&ctx); 2154 #else 2155 ext4fs_dirhash(name, namelen, &hinfo); 2156 #endif 2157 memset(frames, 0, sizeof(frames)); 2158 frame = frames; 2159 frame->entries = entries; 2160 frame->at = entries; 2161 frame->bh = bh; 2162 bh = bh2; 2163 2164 retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 2165 if (retval) 2166 goto out_frames; 2167 retval = ext4_handle_dirty_dirent_node(handle, dir, bh); 2168 if (retval) 2169 goto out_frames; 2170 2171 de = do_split(handle,dir, &bh, frame, &hinfo); 2172 if (IS_ERR(de)) { 2173 retval = PTR_ERR(de); 2174 goto out_frames; 2175 } 2176 dx_release(frames); 2177 2178 retval = add_dirent_to_buf(handle, dentry, inode, de, bh); 2179 brelse(bh); 2180 return retval; 2181 out_frames: 2182 /* 2183 * Even if the block split failed, we have to properly write 2184 * out all the changes we did so far. Otherwise we can end up 2185 * with corrupted filesystem. 2186 */ 2187 ext4_mark_inode_dirty(handle, dir); 2188 dx_release(frames); 2189 return retval; 2190 } 2191 2192 /* 2193 * ext4_add_entry() 2194 * 2195 * adds a file entry to the specified directory, using the same 2196 * semantics as ext4_find_entry(). It returns NULL if it failed. 2197 * 2198 * NOTE!! The inode part of 'de' is left at 0 - which means you 2199 * may not sleep between calling this and putting something into 2200 * the entry, as someone else might have used it while you slept. 2201 */ 2202 static int ext4_add_entry(handle_t *handle, struct dentry *dentry, 2203 struct inode *inode) 2204 { 2205 struct inode *dir = dentry->d_parent->d_inode; 2206 struct buffer_head *bh = NULL; 2207 struct ext4_dir_entry_2 *de; 2208 struct ext4_dir_entry_tail *t; 2209 struct super_block *sb; 2210 int retval; 2211 int dx_fallback=0; 2212 unsigned blocksize; 2213 ext4_lblk_t block, blocks; 2214 int csum_size = 0; 2215 2216 if (ext4_has_metadata_csum(inode->i_sb)) 2217 csum_size = sizeof(struct ext4_dir_entry_tail); 2218 2219 sb = dir->i_sb; 2220 blocksize = sb->s_blocksize; 2221 if (!dentry->d_name.len) 2222 return -EINVAL; 2223 2224 if (ext4_has_inline_data(dir)) { 2225 retval = ext4_try_add_inline_entry(handle, dentry, inode); 2226 if (retval < 0) 2227 return retval; 2228 if (retval == 1) { 2229 retval = 0; 2230 goto out; 2231 } 2232 } 2233 2234 if (is_dx(dir)) { 2235 retval = ext4_dx_add_entry(handle, dentry, inode); 2236 if (!retval || (retval != ERR_BAD_DX_DIR)) 2237 goto out; 2238 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX); 2239 dx_fallback++; 2240 ext4_mark_inode_dirty(handle, dir); 2241 } 2242 blocks = dir->i_size >> sb->s_blocksize_bits; 2243 for (block = 0; block < blocks; block++) { 2244 bh = ext4_read_dirblock(dir, block, DIRENT); 2245 if (IS_ERR(bh)) 2246 return PTR_ERR(bh); 2247 2248 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh); 2249 if (retval != -ENOSPC) 2250 goto out; 2251 2252 if (blocks == 1 && !dx_fallback && 2253 EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) { 2254 retval = make_indexed_dir(handle, dentry, inode, bh); 2255 bh = NULL; /* make_indexed_dir releases bh */ 2256 goto out; 2257 } 2258 brelse(bh); 2259 } 2260 bh = ext4_append(handle, dir, &block); 2261 if (IS_ERR(bh)) 2262 return PTR_ERR(bh); 2263 de = (struct ext4_dir_entry_2 *) bh->b_data; 2264 de->inode = 0; 2265 de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize); 2266 2267 if (csum_size) { 2268 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize); 2269 initialize_dirent_tail(t, blocksize); 2270 } 2271 2272 retval = add_dirent_to_buf(handle, dentry, inode, de, bh); 2273 out: 2274 brelse(bh); 2275 if (retval == 0) 2276 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY); 2277 return retval; 2278 } 2279 2280 /* 2281 * Returns 0 for success, or a negative error value 2282 */ 2283 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry, 2284 struct inode *inode) 2285 { 2286 struct dx_frame frames[2], *frame; 2287 struct dx_entry *entries, *at; 2288 struct dx_hash_info hinfo; 2289 struct buffer_head *bh; 2290 struct inode *dir = dentry->d_parent->d_inode; 2291 struct super_block *sb = dir->i_sb; 2292 struct ext4_dir_entry_2 *de; 2293 int err; 2294 2295 frame = dx_probe(&dentry->d_name, dir, &hinfo, frames); 2296 if (IS_ERR(frame)) 2297 return PTR_ERR(frame); 2298 entries = frame->entries; 2299 at = frame->at; 2300 bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT); 2301 if (IS_ERR(bh)) { 2302 err = PTR_ERR(bh); 2303 bh = NULL; 2304 goto cleanup; 2305 } 2306 2307 BUFFER_TRACE(bh, "get_write_access"); 2308 err = ext4_journal_get_write_access(handle, bh); 2309 if (err) 2310 goto journal_error; 2311 2312 err = add_dirent_to_buf(handle, dentry, inode, NULL, bh); 2313 if (err != -ENOSPC) 2314 goto cleanup; 2315 2316 /* Block full, should compress but for now just split */ 2317 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n", 2318 dx_get_count(entries), dx_get_limit(entries))); 2319 /* Need to split index? */ 2320 if (dx_get_count(entries) == dx_get_limit(entries)) { 2321 ext4_lblk_t newblock; 2322 unsigned icount = dx_get_count(entries); 2323 int levels = frame - frames; 2324 struct dx_entry *entries2; 2325 struct dx_node *node2; 2326 struct buffer_head *bh2; 2327 2328 if (levels && (dx_get_count(frames->entries) == 2329 dx_get_limit(frames->entries))) { 2330 ext4_warning(sb, "Directory index full!"); 2331 err = -ENOSPC; 2332 goto cleanup; 2333 } 2334 bh2 = ext4_append(handle, dir, &newblock); 2335 if (IS_ERR(bh2)) { 2336 err = PTR_ERR(bh2); 2337 goto cleanup; 2338 } 2339 node2 = (struct dx_node *)(bh2->b_data); 2340 entries2 = node2->entries; 2341 memset(&node2->fake, 0, sizeof(struct fake_dirent)); 2342 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize, 2343 sb->s_blocksize); 2344 BUFFER_TRACE(frame->bh, "get_write_access"); 2345 err = ext4_journal_get_write_access(handle, frame->bh); 2346 if (err) 2347 goto journal_error; 2348 if (levels) { 2349 unsigned icount1 = icount/2, icount2 = icount - icount1; 2350 unsigned hash2 = dx_get_hash(entries + icount1); 2351 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n", 2352 icount1, icount2)); 2353 2354 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */ 2355 err = ext4_journal_get_write_access(handle, 2356 frames[0].bh); 2357 if (err) 2358 goto journal_error; 2359 2360 memcpy((char *) entries2, (char *) (entries + icount1), 2361 icount2 * sizeof(struct dx_entry)); 2362 dx_set_count(entries, icount1); 2363 dx_set_count(entries2, icount2); 2364 dx_set_limit(entries2, dx_node_limit(dir)); 2365 2366 /* Which index block gets the new entry? */ 2367 if (at - entries >= icount1) { 2368 frame->at = at = at - entries - icount1 + entries2; 2369 frame->entries = entries = entries2; 2370 swap(frame->bh, bh2); 2371 } 2372 dx_insert_block(frames + 0, hash2, newblock); 2373 dxtrace(dx_show_index("node", frames[1].entries)); 2374 dxtrace(dx_show_index("node", 2375 ((struct dx_node *) bh2->b_data)->entries)); 2376 err = ext4_handle_dirty_dx_node(handle, dir, bh2); 2377 if (err) 2378 goto journal_error; 2379 brelse (bh2); 2380 } else { 2381 dxtrace(printk(KERN_DEBUG 2382 "Creating second level index...\n")); 2383 memcpy((char *) entries2, (char *) entries, 2384 icount * sizeof(struct dx_entry)); 2385 dx_set_limit(entries2, dx_node_limit(dir)); 2386 2387 /* Set up root */ 2388 dx_set_count(entries, 1); 2389 dx_set_block(entries + 0, newblock); 2390 ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1; 2391 2392 /* Add new access path frame */ 2393 frame = frames + 1; 2394 frame->at = at = at - entries + entries2; 2395 frame->entries = entries = entries2; 2396 frame->bh = bh2; 2397 err = ext4_journal_get_write_access(handle, 2398 frame->bh); 2399 if (err) 2400 goto journal_error; 2401 } 2402 err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh); 2403 if (err) { 2404 ext4_std_error(inode->i_sb, err); 2405 goto cleanup; 2406 } 2407 } 2408 de = do_split(handle, dir, &bh, frame, &hinfo); 2409 if (IS_ERR(de)) { 2410 err = PTR_ERR(de); 2411 goto cleanup; 2412 } 2413 err = add_dirent_to_buf(handle, dentry, inode, de, bh); 2414 goto cleanup; 2415 2416 journal_error: 2417 ext4_std_error(dir->i_sb, err); 2418 cleanup: 2419 brelse(bh); 2420 dx_release(frames); 2421 return err; 2422 } 2423 2424 /* 2425 * ext4_generic_delete_entry deletes a directory entry by merging it 2426 * with the previous entry 2427 */ 2428 int ext4_generic_delete_entry(handle_t *handle, 2429 struct inode *dir, 2430 struct ext4_dir_entry_2 *de_del, 2431 struct buffer_head *bh, 2432 void *entry_buf, 2433 int buf_size, 2434 int csum_size) 2435 { 2436 struct ext4_dir_entry_2 *de, *pde; 2437 unsigned int blocksize = dir->i_sb->s_blocksize; 2438 int i; 2439 2440 i = 0; 2441 pde = NULL; 2442 de = (struct ext4_dir_entry_2 *)entry_buf; 2443 while (i < buf_size - csum_size) { 2444 if (ext4_check_dir_entry(dir, NULL, de, bh, 2445 bh->b_data, bh->b_size, i)) 2446 return -EIO; 2447 if (de == de_del) { 2448 if (pde) 2449 pde->rec_len = ext4_rec_len_to_disk( 2450 ext4_rec_len_from_disk(pde->rec_len, 2451 blocksize) + 2452 ext4_rec_len_from_disk(de->rec_len, 2453 blocksize), 2454 blocksize); 2455 else 2456 de->inode = 0; 2457 dir->i_version++; 2458 return 0; 2459 } 2460 i += ext4_rec_len_from_disk(de->rec_len, blocksize); 2461 pde = de; 2462 de = ext4_next_entry(de, blocksize); 2463 } 2464 return -ENOENT; 2465 } 2466 2467 static int ext4_delete_entry(handle_t *handle, 2468 struct inode *dir, 2469 struct ext4_dir_entry_2 *de_del, 2470 struct buffer_head *bh) 2471 { 2472 int err, csum_size = 0; 2473 2474 if (ext4_has_inline_data(dir)) { 2475 int has_inline_data = 1; 2476 err = ext4_delete_inline_entry(handle, dir, de_del, bh, 2477 &has_inline_data); 2478 if (has_inline_data) 2479 return err; 2480 } 2481 2482 if (ext4_has_metadata_csum(dir->i_sb)) 2483 csum_size = sizeof(struct ext4_dir_entry_tail); 2484 2485 BUFFER_TRACE(bh, "get_write_access"); 2486 err = ext4_journal_get_write_access(handle, bh); 2487 if (unlikely(err)) 2488 goto out; 2489 2490 err = ext4_generic_delete_entry(handle, dir, de_del, 2491 bh, bh->b_data, 2492 dir->i_sb->s_blocksize, csum_size); 2493 if (err) 2494 goto out; 2495 2496 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); 2497 err = ext4_handle_dirty_dirent_node(handle, dir, bh); 2498 if (unlikely(err)) 2499 goto out; 2500 2501 return 0; 2502 out: 2503 if (err != -ENOENT) 2504 ext4_std_error(dir->i_sb, err); 2505 return err; 2506 } 2507 2508 /* 2509 * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2, 2510 * since this indicates that nlinks count was previously 1. 2511 */ 2512 static void ext4_inc_count(handle_t *handle, struct inode *inode) 2513 { 2514 inc_nlink(inode); 2515 if (is_dx(inode) && inode->i_nlink > 1) { 2516 /* limit is 16-bit i_links_count */ 2517 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) { 2518 set_nlink(inode, 1); 2519 EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb, 2520 EXT4_FEATURE_RO_COMPAT_DIR_NLINK); 2521 } 2522 } 2523 } 2524 2525 /* 2526 * If a directory had nlink == 1, then we should let it be 1. This indicates 2527 * directory has >EXT4_LINK_MAX subdirs. 2528 */ 2529 static void ext4_dec_count(handle_t *handle, struct inode *inode) 2530 { 2531 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2) 2532 drop_nlink(inode); 2533 } 2534 2535 2536 static int ext4_add_nondir(handle_t *handle, 2537 struct dentry *dentry, struct inode *inode) 2538 { 2539 int err = ext4_add_entry(handle, dentry, inode); 2540 if (!err) { 2541 ext4_mark_inode_dirty(handle, inode); 2542 unlock_new_inode(inode); 2543 d_instantiate(dentry, inode); 2544 return 0; 2545 } 2546 drop_nlink(inode); 2547 unlock_new_inode(inode); 2548 iput(inode); 2549 return err; 2550 } 2551 2552 /* 2553 * By the time this is called, we already have created 2554 * the directory cache entry for the new file, but it 2555 * is so far negative - it has no inode. 2556 * 2557 * If the create succeeds, we fill in the inode information 2558 * with d_instantiate(). 2559 */ 2560 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode, 2561 bool excl) 2562 { 2563 handle_t *handle; 2564 struct inode *inode; 2565 int err, credits, retries = 0; 2566 2567 dquot_initialize(dir); 2568 2569 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2570 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2571 retry: 2572 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0, 2573 NULL, EXT4_HT_DIR, credits); 2574 handle = ext4_journal_current_handle(); 2575 err = PTR_ERR(inode); 2576 if (!IS_ERR(inode)) { 2577 inode->i_op = &ext4_file_inode_operations; 2578 inode->i_fop = &ext4_file_operations; 2579 ext4_set_aops(inode); 2580 err = 0; 2581 #ifdef CONFIG_EXT4_FS_ENCRYPTION 2582 if (!err && (ext4_encrypted_inode(dir) || 2583 DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb)))) { 2584 err = ext4_inherit_context(dir, inode); 2585 if (err) { 2586 clear_nlink(inode); 2587 unlock_new_inode(inode); 2588 iput(inode); 2589 } 2590 } 2591 #endif 2592 if (!err) 2593 err = ext4_add_nondir(handle, dentry, inode); 2594 if (!err && IS_DIRSYNC(dir)) 2595 ext4_handle_sync(handle); 2596 } 2597 if (handle) 2598 ext4_journal_stop(handle); 2599 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2600 goto retry; 2601 return err; 2602 } 2603 2604 static int ext4_mknod(struct inode *dir, struct dentry *dentry, 2605 umode_t mode, dev_t rdev) 2606 { 2607 handle_t *handle; 2608 struct inode *inode; 2609 int err, credits, retries = 0; 2610 2611 if (!new_valid_dev(rdev)) 2612 return -EINVAL; 2613 2614 dquot_initialize(dir); 2615 2616 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2617 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2618 retry: 2619 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0, 2620 NULL, EXT4_HT_DIR, credits); 2621 handle = ext4_journal_current_handle(); 2622 err = PTR_ERR(inode); 2623 if (!IS_ERR(inode)) { 2624 init_special_inode(inode, inode->i_mode, rdev); 2625 inode->i_op = &ext4_special_inode_operations; 2626 err = ext4_add_nondir(handle, dentry, inode); 2627 if (!err && IS_DIRSYNC(dir)) 2628 ext4_handle_sync(handle); 2629 } 2630 if (handle) 2631 ext4_journal_stop(handle); 2632 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2633 goto retry; 2634 return err; 2635 } 2636 2637 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) 2638 { 2639 handle_t *handle; 2640 struct inode *inode; 2641 int err, retries = 0; 2642 2643 dquot_initialize(dir); 2644 2645 retry: 2646 inode = ext4_new_inode_start_handle(dir, mode, 2647 NULL, 0, NULL, 2648 EXT4_HT_DIR, 2649 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) + 2650 4 + EXT4_XATTR_TRANS_BLOCKS); 2651 handle = ext4_journal_current_handle(); 2652 err = PTR_ERR(inode); 2653 if (!IS_ERR(inode)) { 2654 inode->i_op = &ext4_file_inode_operations; 2655 inode->i_fop = &ext4_file_operations; 2656 ext4_set_aops(inode); 2657 d_tmpfile(dentry, inode); 2658 err = ext4_orphan_add(handle, inode); 2659 if (err) 2660 goto err_unlock_inode; 2661 mark_inode_dirty(inode); 2662 unlock_new_inode(inode); 2663 } 2664 if (handle) 2665 ext4_journal_stop(handle); 2666 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2667 goto retry; 2668 return err; 2669 err_unlock_inode: 2670 ext4_journal_stop(handle); 2671 unlock_new_inode(inode); 2672 return err; 2673 } 2674 2675 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode, 2676 struct ext4_dir_entry_2 *de, 2677 int blocksize, int csum_size, 2678 unsigned int parent_ino, int dotdot_real_len) 2679 { 2680 de->inode = cpu_to_le32(inode->i_ino); 2681 de->name_len = 1; 2682 de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len), 2683 blocksize); 2684 strcpy(de->name, "."); 2685 ext4_set_de_type(inode->i_sb, de, S_IFDIR); 2686 2687 de = ext4_next_entry(de, blocksize); 2688 de->inode = cpu_to_le32(parent_ino); 2689 de->name_len = 2; 2690 if (!dotdot_real_len) 2691 de->rec_len = ext4_rec_len_to_disk(blocksize - 2692 (csum_size + EXT4_DIR_REC_LEN(1)), 2693 blocksize); 2694 else 2695 de->rec_len = ext4_rec_len_to_disk( 2696 EXT4_DIR_REC_LEN(de->name_len), blocksize); 2697 strcpy(de->name, ".."); 2698 ext4_set_de_type(inode->i_sb, de, S_IFDIR); 2699 2700 return ext4_next_entry(de, blocksize); 2701 } 2702 2703 static int ext4_init_new_dir(handle_t *handle, struct inode *dir, 2704 struct inode *inode) 2705 { 2706 struct buffer_head *dir_block = NULL; 2707 struct ext4_dir_entry_2 *de; 2708 struct ext4_dir_entry_tail *t; 2709 ext4_lblk_t block = 0; 2710 unsigned int blocksize = dir->i_sb->s_blocksize; 2711 int csum_size = 0; 2712 int err; 2713 2714 if (ext4_has_metadata_csum(dir->i_sb)) 2715 csum_size = sizeof(struct ext4_dir_entry_tail); 2716 2717 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) { 2718 err = ext4_try_create_inline_dir(handle, dir, inode); 2719 if (err < 0 && err != -ENOSPC) 2720 goto out; 2721 if (!err) 2722 goto out; 2723 } 2724 2725 inode->i_size = 0; 2726 dir_block = ext4_append(handle, inode, &block); 2727 if (IS_ERR(dir_block)) 2728 return PTR_ERR(dir_block); 2729 de = (struct ext4_dir_entry_2 *)dir_block->b_data; 2730 ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0); 2731 set_nlink(inode, 2); 2732 if (csum_size) { 2733 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize); 2734 initialize_dirent_tail(t, blocksize); 2735 } 2736 2737 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata"); 2738 err = ext4_handle_dirty_dirent_node(handle, inode, dir_block); 2739 if (err) 2740 goto out; 2741 set_buffer_verified(dir_block); 2742 out: 2743 brelse(dir_block); 2744 return err; 2745 } 2746 2747 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) 2748 { 2749 handle_t *handle; 2750 struct inode *inode; 2751 int err, credits, retries = 0; 2752 2753 if (EXT4_DIR_LINK_MAX(dir)) 2754 return -EMLINK; 2755 2756 dquot_initialize(dir); 2757 2758 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2759 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2760 retry: 2761 inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode, 2762 &dentry->d_name, 2763 0, NULL, EXT4_HT_DIR, credits); 2764 handle = ext4_journal_current_handle(); 2765 err = PTR_ERR(inode); 2766 if (IS_ERR(inode)) 2767 goto out_stop; 2768 2769 inode->i_op = &ext4_dir_inode_operations; 2770 inode->i_fop = &ext4_dir_operations; 2771 err = ext4_init_new_dir(handle, dir, inode); 2772 if (err) 2773 goto out_clear_inode; 2774 #ifdef CONFIG_EXT4_FS_ENCRYPTION 2775 if (ext4_encrypted_inode(dir) || 2776 DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb))) { 2777 err = ext4_inherit_context(dir, inode); 2778 if (err) 2779 goto out_clear_inode; 2780 } 2781 #endif 2782 err = ext4_mark_inode_dirty(handle, inode); 2783 if (!err) 2784 err = ext4_add_entry(handle, dentry, inode); 2785 if (err) { 2786 out_clear_inode: 2787 clear_nlink(inode); 2788 unlock_new_inode(inode); 2789 ext4_mark_inode_dirty(handle, inode); 2790 iput(inode); 2791 goto out_stop; 2792 } 2793 ext4_inc_count(handle, dir); 2794 ext4_update_dx_flag(dir); 2795 err = ext4_mark_inode_dirty(handle, dir); 2796 if (err) 2797 goto out_clear_inode; 2798 unlock_new_inode(inode); 2799 d_instantiate(dentry, inode); 2800 if (IS_DIRSYNC(dir)) 2801 ext4_handle_sync(handle); 2802 2803 out_stop: 2804 if (handle) 2805 ext4_journal_stop(handle); 2806 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2807 goto retry; 2808 return err; 2809 } 2810 2811 /* 2812 * routine to check that the specified directory is empty (for rmdir) 2813 */ 2814 int ext4_empty_dir(struct inode *inode) 2815 { 2816 unsigned int offset; 2817 struct buffer_head *bh; 2818 struct ext4_dir_entry_2 *de, *de1; 2819 struct super_block *sb; 2820 int err = 0; 2821 2822 if (ext4_has_inline_data(inode)) { 2823 int has_inline_data = 1; 2824 2825 err = empty_inline_dir(inode, &has_inline_data); 2826 if (has_inline_data) 2827 return err; 2828 } 2829 2830 sb = inode->i_sb; 2831 if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) { 2832 EXT4_ERROR_INODE(inode, "invalid size"); 2833 return 1; 2834 } 2835 bh = ext4_read_dirblock(inode, 0, EITHER); 2836 if (IS_ERR(bh)) 2837 return 1; 2838 2839 de = (struct ext4_dir_entry_2 *) bh->b_data; 2840 de1 = ext4_next_entry(de, sb->s_blocksize); 2841 if (le32_to_cpu(de->inode) != inode->i_ino || 2842 !le32_to_cpu(de1->inode) || 2843 strcmp(".", de->name) || 2844 strcmp("..", de1->name)) { 2845 ext4_warning(inode->i_sb, 2846 "bad directory (dir #%lu) - no `.' or `..'", 2847 inode->i_ino); 2848 brelse(bh); 2849 return 1; 2850 } 2851 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) + 2852 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize); 2853 de = ext4_next_entry(de1, sb->s_blocksize); 2854 while (offset < inode->i_size) { 2855 if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) { 2856 unsigned int lblock; 2857 err = 0; 2858 brelse(bh); 2859 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb); 2860 bh = ext4_read_dirblock(inode, lblock, EITHER); 2861 if (IS_ERR(bh)) 2862 return 1; 2863 de = (struct ext4_dir_entry_2 *) bh->b_data; 2864 } 2865 if (ext4_check_dir_entry(inode, NULL, de, bh, 2866 bh->b_data, bh->b_size, offset)) { 2867 de = (struct ext4_dir_entry_2 *)(bh->b_data + 2868 sb->s_blocksize); 2869 offset = (offset | (sb->s_blocksize - 1)) + 1; 2870 continue; 2871 } 2872 if (le32_to_cpu(de->inode)) { 2873 brelse(bh); 2874 return 0; 2875 } 2876 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); 2877 de = ext4_next_entry(de, sb->s_blocksize); 2878 } 2879 brelse(bh); 2880 return 1; 2881 } 2882 2883 /* 2884 * ext4_orphan_add() links an unlinked or truncated inode into a list of 2885 * such inodes, starting at the superblock, in case we crash before the 2886 * file is closed/deleted, or in case the inode truncate spans multiple 2887 * transactions and the last transaction is not recovered after a crash. 2888 * 2889 * At filesystem recovery time, we walk this list deleting unlinked 2890 * inodes and truncating linked inodes in ext4_orphan_cleanup(). 2891 * 2892 * Orphan list manipulation functions must be called under i_mutex unless 2893 * we are just creating the inode or deleting it. 2894 */ 2895 int ext4_orphan_add(handle_t *handle, struct inode *inode) 2896 { 2897 struct super_block *sb = inode->i_sb; 2898 struct ext4_sb_info *sbi = EXT4_SB(sb); 2899 struct ext4_iloc iloc; 2900 int err = 0, rc; 2901 bool dirty = false; 2902 2903 if (!sbi->s_journal || is_bad_inode(inode)) 2904 return 0; 2905 2906 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) && 2907 !mutex_is_locked(&inode->i_mutex)); 2908 /* 2909 * Exit early if inode already is on orphan list. This is a big speedup 2910 * since we don't have to contend on the global s_orphan_lock. 2911 */ 2912 if (!list_empty(&EXT4_I(inode)->i_orphan)) 2913 return 0; 2914 2915 /* 2916 * Orphan handling is only valid for files with data blocks 2917 * being truncated, or files being unlinked. Note that we either 2918 * hold i_mutex, or the inode can not be referenced from outside, 2919 * so i_nlink should not be bumped due to race 2920 */ 2921 J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 2922 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0); 2923 2924 BUFFER_TRACE(sbi->s_sbh, "get_write_access"); 2925 err = ext4_journal_get_write_access(handle, sbi->s_sbh); 2926 if (err) 2927 goto out; 2928 2929 err = ext4_reserve_inode_write(handle, inode, &iloc); 2930 if (err) 2931 goto out; 2932 2933 mutex_lock(&sbi->s_orphan_lock); 2934 /* 2935 * Due to previous errors inode may be already a part of on-disk 2936 * orphan list. If so skip on-disk list modification. 2937 */ 2938 if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) > 2939 (le32_to_cpu(sbi->s_es->s_inodes_count))) { 2940 /* Insert this inode at the head of the on-disk orphan list */ 2941 NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan); 2942 sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino); 2943 dirty = true; 2944 } 2945 list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan); 2946 mutex_unlock(&sbi->s_orphan_lock); 2947 2948 if (dirty) { 2949 err = ext4_handle_dirty_super(handle, sb); 2950 rc = ext4_mark_iloc_dirty(handle, inode, &iloc); 2951 if (!err) 2952 err = rc; 2953 if (err) { 2954 /* 2955 * We have to remove inode from in-memory list if 2956 * addition to on disk orphan list failed. Stray orphan 2957 * list entries can cause panics at unmount time. 2958 */ 2959 mutex_lock(&sbi->s_orphan_lock); 2960 list_del(&EXT4_I(inode)->i_orphan); 2961 mutex_unlock(&sbi->s_orphan_lock); 2962 } 2963 } 2964 jbd_debug(4, "superblock will point to %lu\n", inode->i_ino); 2965 jbd_debug(4, "orphan inode %lu will point to %d\n", 2966 inode->i_ino, NEXT_ORPHAN(inode)); 2967 out: 2968 ext4_std_error(sb, err); 2969 return err; 2970 } 2971 2972 /* 2973 * ext4_orphan_del() removes an unlinked or truncated inode from the list 2974 * of such inodes stored on disk, because it is finally being cleaned up. 2975 */ 2976 int ext4_orphan_del(handle_t *handle, struct inode *inode) 2977 { 2978 struct list_head *prev; 2979 struct ext4_inode_info *ei = EXT4_I(inode); 2980 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 2981 __u32 ino_next; 2982 struct ext4_iloc iloc; 2983 int err = 0; 2984 2985 if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS)) 2986 return 0; 2987 2988 WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) && 2989 !mutex_is_locked(&inode->i_mutex)); 2990 /* Do this quick check before taking global s_orphan_lock. */ 2991 if (list_empty(&ei->i_orphan)) 2992 return 0; 2993 2994 if (handle) { 2995 /* Grab inode buffer early before taking global s_orphan_lock */ 2996 err = ext4_reserve_inode_write(handle, inode, &iloc); 2997 } 2998 2999 mutex_lock(&sbi->s_orphan_lock); 3000 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino); 3001 3002 prev = ei->i_orphan.prev; 3003 list_del_init(&ei->i_orphan); 3004 3005 /* If we're on an error path, we may not have a valid 3006 * transaction handle with which to update the orphan list on 3007 * disk, but we still need to remove the inode from the linked 3008 * list in memory. */ 3009 if (!handle || err) { 3010 mutex_unlock(&sbi->s_orphan_lock); 3011 goto out_err; 3012 } 3013 3014 ino_next = NEXT_ORPHAN(inode); 3015 if (prev == &sbi->s_orphan) { 3016 jbd_debug(4, "superblock will point to %u\n", ino_next); 3017 BUFFER_TRACE(sbi->s_sbh, "get_write_access"); 3018 err = ext4_journal_get_write_access(handle, sbi->s_sbh); 3019 if (err) { 3020 mutex_unlock(&sbi->s_orphan_lock); 3021 goto out_brelse; 3022 } 3023 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next); 3024 mutex_unlock(&sbi->s_orphan_lock); 3025 err = ext4_handle_dirty_super(handle, inode->i_sb); 3026 } else { 3027 struct ext4_iloc iloc2; 3028 struct inode *i_prev = 3029 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode; 3030 3031 jbd_debug(4, "orphan inode %lu will point to %u\n", 3032 i_prev->i_ino, ino_next); 3033 err = ext4_reserve_inode_write(handle, i_prev, &iloc2); 3034 if (err) { 3035 mutex_unlock(&sbi->s_orphan_lock); 3036 goto out_brelse; 3037 } 3038 NEXT_ORPHAN(i_prev) = ino_next; 3039 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2); 3040 mutex_unlock(&sbi->s_orphan_lock); 3041 } 3042 if (err) 3043 goto out_brelse; 3044 NEXT_ORPHAN(inode) = 0; 3045 err = ext4_mark_iloc_dirty(handle, inode, &iloc); 3046 out_err: 3047 ext4_std_error(inode->i_sb, err); 3048 return err; 3049 3050 out_brelse: 3051 brelse(iloc.bh); 3052 goto out_err; 3053 } 3054 3055 static int ext4_rmdir(struct inode *dir, struct dentry *dentry) 3056 { 3057 int retval; 3058 struct inode *inode; 3059 struct buffer_head *bh; 3060 struct ext4_dir_entry_2 *de; 3061 handle_t *handle = NULL; 3062 3063 /* Initialize quotas before so that eventual writes go in 3064 * separate transaction */ 3065 dquot_initialize(dir); 3066 dquot_initialize(dentry->d_inode); 3067 3068 retval = -ENOENT; 3069 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); 3070 if (IS_ERR(bh)) 3071 return PTR_ERR(bh); 3072 if (!bh) 3073 goto end_rmdir; 3074 3075 inode = dentry->d_inode; 3076 3077 retval = -EIO; 3078 if (le32_to_cpu(de->inode) != inode->i_ino) 3079 goto end_rmdir; 3080 3081 retval = -ENOTEMPTY; 3082 if (!ext4_empty_dir(inode)) 3083 goto end_rmdir; 3084 3085 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3086 EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); 3087 if (IS_ERR(handle)) { 3088 retval = PTR_ERR(handle); 3089 handle = NULL; 3090 goto end_rmdir; 3091 } 3092 3093 if (IS_DIRSYNC(dir)) 3094 ext4_handle_sync(handle); 3095 3096 retval = ext4_delete_entry(handle, dir, de, bh); 3097 if (retval) 3098 goto end_rmdir; 3099 if (!EXT4_DIR_LINK_EMPTY(inode)) 3100 ext4_warning(inode->i_sb, 3101 "empty directory has too many links (%d)", 3102 inode->i_nlink); 3103 inode->i_version++; 3104 clear_nlink(inode); 3105 /* There's no need to set i_disksize: the fact that i_nlink is 3106 * zero will ensure that the right thing happens during any 3107 * recovery. */ 3108 inode->i_size = 0; 3109 ext4_orphan_add(handle, inode); 3110 inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode); 3111 ext4_mark_inode_dirty(handle, inode); 3112 ext4_dec_count(handle, dir); 3113 ext4_update_dx_flag(dir); 3114 ext4_mark_inode_dirty(handle, dir); 3115 3116 end_rmdir: 3117 brelse(bh); 3118 if (handle) 3119 ext4_journal_stop(handle); 3120 return retval; 3121 } 3122 3123 static int ext4_unlink(struct inode *dir, struct dentry *dentry) 3124 { 3125 int retval; 3126 struct inode *inode; 3127 struct buffer_head *bh; 3128 struct ext4_dir_entry_2 *de; 3129 handle_t *handle = NULL; 3130 3131 trace_ext4_unlink_enter(dir, dentry); 3132 /* Initialize quotas before so that eventual writes go 3133 * in separate transaction */ 3134 dquot_initialize(dir); 3135 dquot_initialize(dentry->d_inode); 3136 3137 retval = -ENOENT; 3138 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); 3139 if (IS_ERR(bh)) 3140 return PTR_ERR(bh); 3141 if (!bh) 3142 goto end_unlink; 3143 3144 inode = dentry->d_inode; 3145 3146 retval = -EIO; 3147 if (le32_to_cpu(de->inode) != inode->i_ino) 3148 goto end_unlink; 3149 3150 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3151 EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); 3152 if (IS_ERR(handle)) { 3153 retval = PTR_ERR(handle); 3154 handle = NULL; 3155 goto end_unlink; 3156 } 3157 3158 if (IS_DIRSYNC(dir)) 3159 ext4_handle_sync(handle); 3160 3161 if (!inode->i_nlink) { 3162 ext4_warning(inode->i_sb, 3163 "Deleting nonexistent file (%lu), %d", 3164 inode->i_ino, inode->i_nlink); 3165 set_nlink(inode, 1); 3166 } 3167 retval = ext4_delete_entry(handle, dir, de, bh); 3168 if (retval) 3169 goto end_unlink; 3170 dir->i_ctime = dir->i_mtime = ext4_current_time(dir); 3171 ext4_update_dx_flag(dir); 3172 ext4_mark_inode_dirty(handle, dir); 3173 drop_nlink(inode); 3174 if (!inode->i_nlink) 3175 ext4_orphan_add(handle, inode); 3176 inode->i_ctime = ext4_current_time(inode); 3177 ext4_mark_inode_dirty(handle, inode); 3178 3179 end_unlink: 3180 brelse(bh); 3181 if (handle) 3182 ext4_journal_stop(handle); 3183 trace_ext4_unlink_exit(dentry, retval); 3184 return retval; 3185 } 3186 3187 static int ext4_symlink(struct inode *dir, 3188 struct dentry *dentry, const char *symname) 3189 { 3190 handle_t *handle; 3191 struct inode *inode; 3192 int err, len = strlen(symname); 3193 int credits; 3194 bool encryption_required; 3195 struct ext4_str disk_link; 3196 struct ext4_encrypted_symlink_data *sd = NULL; 3197 3198 disk_link.len = len + 1; 3199 disk_link.name = (char *) symname; 3200 3201 encryption_required = (ext4_encrypted_inode(dir) || 3202 DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb))); 3203 if (encryption_required) 3204 disk_link.len = encrypted_symlink_data_len(len) + 1; 3205 if (disk_link.len > dir->i_sb->s_blocksize) 3206 return -ENAMETOOLONG; 3207 3208 dquot_initialize(dir); 3209 3210 if ((disk_link.len > EXT4_N_BLOCKS * 4)) { 3211 /* 3212 * For non-fast symlinks, we just allocate inode and put it on 3213 * orphan list in the first transaction => we need bitmap, 3214 * group descriptor, sb, inode block, quota blocks, and 3215 * possibly selinux xattr blocks. 3216 */ 3217 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) + 3218 EXT4_XATTR_TRANS_BLOCKS; 3219 } else { 3220 /* 3221 * Fast symlink. We have to add entry to directory 3222 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS), 3223 * allocate new inode (bitmap, group descriptor, inode block, 3224 * quota blocks, sb is already counted in previous macros). 3225 */ 3226 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3227 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3; 3228 } 3229 3230 inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO, 3231 &dentry->d_name, 0, NULL, 3232 EXT4_HT_DIR, credits); 3233 handle = ext4_journal_current_handle(); 3234 if (IS_ERR(inode)) { 3235 if (handle) 3236 ext4_journal_stop(handle); 3237 return PTR_ERR(inode); 3238 } 3239 3240 if (encryption_required) { 3241 struct ext4_fname_crypto_ctx *ctx = NULL; 3242 struct qstr istr; 3243 struct ext4_str ostr; 3244 3245 sd = kzalloc(disk_link.len, GFP_NOFS); 3246 if (!sd) { 3247 err = -ENOMEM; 3248 goto err_drop_inode; 3249 } 3250 err = ext4_inherit_context(dir, inode); 3251 if (err) 3252 goto err_drop_inode; 3253 ctx = ext4_get_fname_crypto_ctx(inode, 3254 inode->i_sb->s_blocksize); 3255 if (IS_ERR_OR_NULL(ctx)) { 3256 /* We just set the policy, so ctx should not be NULL */ 3257 err = (ctx == NULL) ? -EIO : PTR_ERR(ctx); 3258 goto err_drop_inode; 3259 } 3260 istr.name = (const unsigned char *) symname; 3261 istr.len = len; 3262 ostr.name = sd->encrypted_path; 3263 err = ext4_fname_usr_to_disk(ctx, &istr, &ostr); 3264 ext4_put_fname_crypto_ctx(&ctx); 3265 if (err < 0) 3266 goto err_drop_inode; 3267 sd->len = cpu_to_le16(ostr.len); 3268 disk_link.name = (char *) sd; 3269 } 3270 3271 if ((disk_link.len > EXT4_N_BLOCKS * 4)) { 3272 inode->i_op = &ext4_symlink_inode_operations; 3273 ext4_set_aops(inode); 3274 /* 3275 * We cannot call page_symlink() with transaction started 3276 * because it calls into ext4_write_begin() which can wait 3277 * for transaction commit if we are running out of space 3278 * and thus we deadlock. So we have to stop transaction now 3279 * and restart it when symlink contents is written. 3280 * 3281 * To keep fs consistent in case of crash, we have to put inode 3282 * to orphan list in the mean time. 3283 */ 3284 drop_nlink(inode); 3285 err = ext4_orphan_add(handle, inode); 3286 ext4_journal_stop(handle); 3287 handle = NULL; 3288 if (err) 3289 goto err_drop_inode; 3290 err = __page_symlink(inode, disk_link.name, disk_link.len, 1); 3291 if (err) 3292 goto err_drop_inode; 3293 /* 3294 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS 3295 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified 3296 */ 3297 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3298 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3299 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1); 3300 if (IS_ERR(handle)) { 3301 err = PTR_ERR(handle); 3302 handle = NULL; 3303 goto err_drop_inode; 3304 } 3305 set_nlink(inode, 1); 3306 err = ext4_orphan_del(handle, inode); 3307 if (err) 3308 goto err_drop_inode; 3309 } else { 3310 /* clear the extent format for fast symlink */ 3311 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS); 3312 inode->i_op = encryption_required ? 3313 &ext4_symlink_inode_operations : 3314 &ext4_fast_symlink_inode_operations; 3315 memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name, 3316 disk_link.len); 3317 inode->i_size = disk_link.len - 1; 3318 } 3319 EXT4_I(inode)->i_disksize = inode->i_size; 3320 err = ext4_add_nondir(handle, dentry, inode); 3321 if (!err && IS_DIRSYNC(dir)) 3322 ext4_handle_sync(handle); 3323 3324 if (handle) 3325 ext4_journal_stop(handle); 3326 kfree(sd); 3327 return err; 3328 err_drop_inode: 3329 if (handle) 3330 ext4_journal_stop(handle); 3331 kfree(sd); 3332 clear_nlink(inode); 3333 unlock_new_inode(inode); 3334 iput(inode); 3335 return err; 3336 } 3337 3338 static int ext4_link(struct dentry *old_dentry, 3339 struct inode *dir, struct dentry *dentry) 3340 { 3341 handle_t *handle; 3342 struct inode *inode = old_dentry->d_inode; 3343 int err, retries = 0; 3344 3345 if (inode->i_nlink >= EXT4_LINK_MAX) 3346 return -EMLINK; 3347 if (ext4_encrypted_inode(dir) && 3348 !ext4_is_child_context_consistent_with_parent(dir, inode)) 3349 return -EPERM; 3350 dquot_initialize(dir); 3351 3352 retry: 3353 handle = ext4_journal_start(dir, EXT4_HT_DIR, 3354 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 3355 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1); 3356 if (IS_ERR(handle)) 3357 return PTR_ERR(handle); 3358 3359 if (IS_DIRSYNC(dir)) 3360 ext4_handle_sync(handle); 3361 3362 inode->i_ctime = ext4_current_time(inode); 3363 ext4_inc_count(handle, inode); 3364 ihold(inode); 3365 3366 err = ext4_add_entry(handle, dentry, inode); 3367 if (!err) { 3368 ext4_mark_inode_dirty(handle, inode); 3369 /* this can happen only for tmpfile being 3370 * linked the first time 3371 */ 3372 if (inode->i_nlink == 1) 3373 ext4_orphan_del(handle, inode); 3374 d_instantiate(dentry, inode); 3375 } else { 3376 drop_nlink(inode); 3377 iput(inode); 3378 } 3379 ext4_journal_stop(handle); 3380 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 3381 goto retry; 3382 return err; 3383 } 3384 3385 3386 /* 3387 * Try to find buffer head where contains the parent block. 3388 * It should be the inode block if it is inlined or the 1st block 3389 * if it is a normal dir. 3390 */ 3391 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle, 3392 struct inode *inode, 3393 int *retval, 3394 struct ext4_dir_entry_2 **parent_de, 3395 int *inlined) 3396 { 3397 struct buffer_head *bh; 3398 3399 if (!ext4_has_inline_data(inode)) { 3400 bh = ext4_read_dirblock(inode, 0, EITHER); 3401 if (IS_ERR(bh)) { 3402 *retval = PTR_ERR(bh); 3403 return NULL; 3404 } 3405 *parent_de = ext4_next_entry( 3406 (struct ext4_dir_entry_2 *)bh->b_data, 3407 inode->i_sb->s_blocksize); 3408 return bh; 3409 } 3410 3411 *inlined = 1; 3412 return ext4_get_first_inline_block(inode, parent_de, retval); 3413 } 3414 3415 struct ext4_renament { 3416 struct inode *dir; 3417 struct dentry *dentry; 3418 struct inode *inode; 3419 bool is_dir; 3420 int dir_nlink_delta; 3421 3422 /* entry for "dentry" */ 3423 struct buffer_head *bh; 3424 struct ext4_dir_entry_2 *de; 3425 int inlined; 3426 3427 /* entry for ".." in inode if it's a directory */ 3428 struct buffer_head *dir_bh; 3429 struct ext4_dir_entry_2 *parent_de; 3430 int dir_inlined; 3431 }; 3432 3433 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent) 3434 { 3435 int retval; 3436 3437 ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode, 3438 &retval, &ent->parent_de, 3439 &ent->dir_inlined); 3440 if (!ent->dir_bh) 3441 return retval; 3442 if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino) 3443 return -EIO; 3444 BUFFER_TRACE(ent->dir_bh, "get_write_access"); 3445 return ext4_journal_get_write_access(handle, ent->dir_bh); 3446 } 3447 3448 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent, 3449 unsigned dir_ino) 3450 { 3451 int retval; 3452 3453 ent->parent_de->inode = cpu_to_le32(dir_ino); 3454 BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata"); 3455 if (!ent->dir_inlined) { 3456 if (is_dx(ent->inode)) { 3457 retval = ext4_handle_dirty_dx_node(handle, 3458 ent->inode, 3459 ent->dir_bh); 3460 } else { 3461 retval = ext4_handle_dirty_dirent_node(handle, 3462 ent->inode, 3463 ent->dir_bh); 3464 } 3465 } else { 3466 retval = ext4_mark_inode_dirty(handle, ent->inode); 3467 } 3468 if (retval) { 3469 ext4_std_error(ent->dir->i_sb, retval); 3470 return retval; 3471 } 3472 return 0; 3473 } 3474 3475 static int ext4_setent(handle_t *handle, struct ext4_renament *ent, 3476 unsigned ino, unsigned file_type) 3477 { 3478 int retval; 3479 3480 BUFFER_TRACE(ent->bh, "get write access"); 3481 retval = ext4_journal_get_write_access(handle, ent->bh); 3482 if (retval) 3483 return retval; 3484 ent->de->inode = cpu_to_le32(ino); 3485 if (EXT4_HAS_INCOMPAT_FEATURE(ent->dir->i_sb, 3486 EXT4_FEATURE_INCOMPAT_FILETYPE)) 3487 ent->de->file_type = file_type; 3488 ent->dir->i_version++; 3489 ent->dir->i_ctime = ent->dir->i_mtime = 3490 ext4_current_time(ent->dir); 3491 ext4_mark_inode_dirty(handle, ent->dir); 3492 BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata"); 3493 if (!ent->inlined) { 3494 retval = ext4_handle_dirty_dirent_node(handle, 3495 ent->dir, ent->bh); 3496 if (unlikely(retval)) { 3497 ext4_std_error(ent->dir->i_sb, retval); 3498 return retval; 3499 } 3500 } 3501 brelse(ent->bh); 3502 ent->bh = NULL; 3503 3504 return 0; 3505 } 3506 3507 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir, 3508 const struct qstr *d_name) 3509 { 3510 int retval = -ENOENT; 3511 struct buffer_head *bh; 3512 struct ext4_dir_entry_2 *de; 3513 3514 bh = ext4_find_entry(dir, d_name, &de, NULL); 3515 if (IS_ERR(bh)) 3516 return PTR_ERR(bh); 3517 if (bh) { 3518 retval = ext4_delete_entry(handle, dir, de, bh); 3519 brelse(bh); 3520 } 3521 return retval; 3522 } 3523 3524 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent, 3525 int force_reread) 3526 { 3527 int retval; 3528 /* 3529 * ent->de could have moved from under us during htree split, so make 3530 * sure that we are deleting the right entry. We might also be pointing 3531 * to a stale entry in the unused part of ent->bh so just checking inum 3532 * and the name isn't enough. 3533 */ 3534 if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino || 3535 ent->de->name_len != ent->dentry->d_name.len || 3536 strncmp(ent->de->name, ent->dentry->d_name.name, 3537 ent->de->name_len) || 3538 force_reread) { 3539 retval = ext4_find_delete_entry(handle, ent->dir, 3540 &ent->dentry->d_name); 3541 } else { 3542 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh); 3543 if (retval == -ENOENT) { 3544 retval = ext4_find_delete_entry(handle, ent->dir, 3545 &ent->dentry->d_name); 3546 } 3547 } 3548 3549 if (retval) { 3550 ext4_warning(ent->dir->i_sb, 3551 "Deleting old file (%lu), %d, error=%d", 3552 ent->dir->i_ino, ent->dir->i_nlink, retval); 3553 } 3554 } 3555 3556 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent) 3557 { 3558 if (ent->dir_nlink_delta) { 3559 if (ent->dir_nlink_delta == -1) 3560 ext4_dec_count(handle, ent->dir); 3561 else 3562 ext4_inc_count(handle, ent->dir); 3563 ext4_mark_inode_dirty(handle, ent->dir); 3564 } 3565 } 3566 3567 static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent, 3568 int credits, handle_t **h) 3569 { 3570 struct inode *wh; 3571 handle_t *handle; 3572 int retries = 0; 3573 3574 /* 3575 * for inode block, sb block, group summaries, 3576 * and inode bitmap 3577 */ 3578 credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) + 3579 EXT4_XATTR_TRANS_BLOCKS + 4); 3580 retry: 3581 wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE, 3582 &ent->dentry->d_name, 0, NULL, 3583 EXT4_HT_DIR, credits); 3584 3585 handle = ext4_journal_current_handle(); 3586 if (IS_ERR(wh)) { 3587 if (handle) 3588 ext4_journal_stop(handle); 3589 if (PTR_ERR(wh) == -ENOSPC && 3590 ext4_should_retry_alloc(ent->dir->i_sb, &retries)) 3591 goto retry; 3592 } else { 3593 *h = handle; 3594 init_special_inode(wh, wh->i_mode, WHITEOUT_DEV); 3595 wh->i_op = &ext4_special_inode_operations; 3596 } 3597 return wh; 3598 } 3599 3600 /* 3601 * Anybody can rename anything with this: the permission checks are left to the 3602 * higher-level routines. 3603 * 3604 * n.b. old_{dentry,inode) refers to the source dentry/inode 3605 * while new_{dentry,inode) refers to the destination dentry/inode 3606 * This comes from rename(const char *oldpath, const char *newpath) 3607 */ 3608 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry, 3609 struct inode *new_dir, struct dentry *new_dentry, 3610 unsigned int flags) 3611 { 3612 handle_t *handle = NULL; 3613 struct ext4_renament old = { 3614 .dir = old_dir, 3615 .dentry = old_dentry, 3616 .inode = old_dentry->d_inode, 3617 }; 3618 struct ext4_renament new = { 3619 .dir = new_dir, 3620 .dentry = new_dentry, 3621 .inode = new_dentry->d_inode, 3622 }; 3623 int force_reread; 3624 int retval; 3625 struct inode *whiteout = NULL; 3626 int credits; 3627 u8 old_file_type; 3628 3629 dquot_initialize(old.dir); 3630 dquot_initialize(new.dir); 3631 3632 /* Initialize quotas before so that eventual writes go 3633 * in separate transaction */ 3634 if (new.inode) 3635 dquot_initialize(new.inode); 3636 3637 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL); 3638 if (IS_ERR(old.bh)) 3639 return PTR_ERR(old.bh); 3640 /* 3641 * Check for inode number is _not_ due to possible IO errors. 3642 * We might rmdir the source, keep it as pwd of some process 3643 * and merrily kill the link to whatever was created under the 3644 * same name. Goodbye sticky bit ;-< 3645 */ 3646 retval = -ENOENT; 3647 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino) 3648 goto end_rename; 3649 3650 if ((old.dir != new.dir) && 3651 ext4_encrypted_inode(new.dir) && 3652 !ext4_is_child_context_consistent_with_parent(new.dir, 3653 old.inode)) { 3654 retval = -EPERM; 3655 goto end_rename; 3656 } 3657 3658 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, 3659 &new.de, &new.inlined); 3660 if (IS_ERR(new.bh)) { 3661 retval = PTR_ERR(new.bh); 3662 new.bh = NULL; 3663 goto end_rename; 3664 } 3665 if (new.bh) { 3666 if (!new.inode) { 3667 brelse(new.bh); 3668 new.bh = NULL; 3669 } 3670 } 3671 if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC)) 3672 ext4_alloc_da_blocks(old.inode); 3673 3674 credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + 3675 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2); 3676 if (!(flags & RENAME_WHITEOUT)) { 3677 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits); 3678 if (IS_ERR(handle)) { 3679 retval = PTR_ERR(handle); 3680 handle = NULL; 3681 goto end_rename; 3682 } 3683 } else { 3684 whiteout = ext4_whiteout_for_rename(&old, credits, &handle); 3685 if (IS_ERR(whiteout)) { 3686 retval = PTR_ERR(whiteout); 3687 whiteout = NULL; 3688 goto end_rename; 3689 } 3690 } 3691 3692 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir)) 3693 ext4_handle_sync(handle); 3694 3695 if (S_ISDIR(old.inode->i_mode)) { 3696 if (new.inode) { 3697 retval = -ENOTEMPTY; 3698 if (!ext4_empty_dir(new.inode)) 3699 goto end_rename; 3700 } else { 3701 retval = -EMLINK; 3702 if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir)) 3703 goto end_rename; 3704 } 3705 retval = ext4_rename_dir_prepare(handle, &old); 3706 if (retval) 3707 goto end_rename; 3708 } 3709 /* 3710 * If we're renaming a file within an inline_data dir and adding or 3711 * setting the new dirent causes a conversion from inline_data to 3712 * extents/blockmap, we need to force the dirent delete code to 3713 * re-read the directory, or else we end up trying to delete a dirent 3714 * from what is now the extent tree root (or a block map). 3715 */ 3716 force_reread = (new.dir->i_ino == old.dir->i_ino && 3717 ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA)); 3718 3719 old_file_type = old.de->file_type; 3720 if (whiteout) { 3721 /* 3722 * Do this before adding a new entry, so the old entry is sure 3723 * to be still pointing to the valid old entry. 3724 */ 3725 retval = ext4_setent(handle, &old, whiteout->i_ino, 3726 EXT4_FT_CHRDEV); 3727 if (retval) 3728 goto end_rename; 3729 ext4_mark_inode_dirty(handle, whiteout); 3730 } 3731 if (!new.bh) { 3732 retval = ext4_add_entry(handle, new.dentry, old.inode); 3733 if (retval) 3734 goto end_rename; 3735 } else { 3736 retval = ext4_setent(handle, &new, 3737 old.inode->i_ino, old_file_type); 3738 if (retval) 3739 goto end_rename; 3740 } 3741 if (force_reread) 3742 force_reread = !ext4_test_inode_flag(new.dir, 3743 EXT4_INODE_INLINE_DATA); 3744 3745 /* 3746 * Like most other Unix systems, set the ctime for inodes on a 3747 * rename. 3748 */ 3749 old.inode->i_ctime = ext4_current_time(old.inode); 3750 ext4_mark_inode_dirty(handle, old.inode); 3751 3752 if (!whiteout) { 3753 /* 3754 * ok, that's it 3755 */ 3756 ext4_rename_delete(handle, &old, force_reread); 3757 } 3758 3759 if (new.inode) { 3760 ext4_dec_count(handle, new.inode); 3761 new.inode->i_ctime = ext4_current_time(new.inode); 3762 } 3763 old.dir->i_ctime = old.dir->i_mtime = ext4_current_time(old.dir); 3764 ext4_update_dx_flag(old.dir); 3765 if (old.dir_bh) { 3766 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); 3767 if (retval) 3768 goto end_rename; 3769 3770 ext4_dec_count(handle, old.dir); 3771 if (new.inode) { 3772 /* checked ext4_empty_dir above, can't have another 3773 * parent, ext4_dec_count() won't work for many-linked 3774 * dirs */ 3775 clear_nlink(new.inode); 3776 } else { 3777 ext4_inc_count(handle, new.dir); 3778 ext4_update_dx_flag(new.dir); 3779 ext4_mark_inode_dirty(handle, new.dir); 3780 } 3781 } 3782 ext4_mark_inode_dirty(handle, old.dir); 3783 if (new.inode) { 3784 ext4_mark_inode_dirty(handle, new.inode); 3785 if (!new.inode->i_nlink) 3786 ext4_orphan_add(handle, new.inode); 3787 } 3788 retval = 0; 3789 3790 end_rename: 3791 brelse(old.dir_bh); 3792 brelse(old.bh); 3793 brelse(new.bh); 3794 if (whiteout) { 3795 if (retval) 3796 drop_nlink(whiteout); 3797 unlock_new_inode(whiteout); 3798 iput(whiteout); 3799 } 3800 if (handle) 3801 ext4_journal_stop(handle); 3802 return retval; 3803 } 3804 3805 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry, 3806 struct inode *new_dir, struct dentry *new_dentry) 3807 { 3808 handle_t *handle = NULL; 3809 struct ext4_renament old = { 3810 .dir = old_dir, 3811 .dentry = old_dentry, 3812 .inode = old_dentry->d_inode, 3813 }; 3814 struct ext4_renament new = { 3815 .dir = new_dir, 3816 .dentry = new_dentry, 3817 .inode = new_dentry->d_inode, 3818 }; 3819 u8 new_file_type; 3820 int retval; 3821 3822 dquot_initialize(old.dir); 3823 dquot_initialize(new.dir); 3824 3825 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, 3826 &old.de, &old.inlined); 3827 if (IS_ERR(old.bh)) 3828 return PTR_ERR(old.bh); 3829 /* 3830 * Check for inode number is _not_ due to possible IO errors. 3831 * We might rmdir the source, keep it as pwd of some process 3832 * and merrily kill the link to whatever was created under the 3833 * same name. Goodbye sticky bit ;-< 3834 */ 3835 retval = -ENOENT; 3836 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino) 3837 goto end_rename; 3838 3839 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, 3840 &new.de, &new.inlined); 3841 if (IS_ERR(new.bh)) { 3842 retval = PTR_ERR(new.bh); 3843 new.bh = NULL; 3844 goto end_rename; 3845 } 3846 3847 /* RENAME_EXCHANGE case: old *and* new must both exist */ 3848 if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino) 3849 goto end_rename; 3850 3851 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, 3852 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + 3853 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2)); 3854 if (IS_ERR(handle)) { 3855 retval = PTR_ERR(handle); 3856 handle = NULL; 3857 goto end_rename; 3858 } 3859 3860 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir)) 3861 ext4_handle_sync(handle); 3862 3863 if (S_ISDIR(old.inode->i_mode)) { 3864 old.is_dir = true; 3865 retval = ext4_rename_dir_prepare(handle, &old); 3866 if (retval) 3867 goto end_rename; 3868 } 3869 if (S_ISDIR(new.inode->i_mode)) { 3870 new.is_dir = true; 3871 retval = ext4_rename_dir_prepare(handle, &new); 3872 if (retval) 3873 goto end_rename; 3874 } 3875 3876 /* 3877 * Other than the special case of overwriting a directory, parents' 3878 * nlink only needs to be modified if this is a cross directory rename. 3879 */ 3880 if (old.dir != new.dir && old.is_dir != new.is_dir) { 3881 old.dir_nlink_delta = old.is_dir ? -1 : 1; 3882 new.dir_nlink_delta = -old.dir_nlink_delta; 3883 retval = -EMLINK; 3884 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) || 3885 (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir))) 3886 goto end_rename; 3887 } 3888 3889 new_file_type = new.de->file_type; 3890 retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type); 3891 if (retval) 3892 goto end_rename; 3893 3894 retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type); 3895 if (retval) 3896 goto end_rename; 3897 3898 /* 3899 * Like most other Unix systems, set the ctime for inodes on a 3900 * rename. 3901 */ 3902 old.inode->i_ctime = ext4_current_time(old.inode); 3903 new.inode->i_ctime = ext4_current_time(new.inode); 3904 ext4_mark_inode_dirty(handle, old.inode); 3905 ext4_mark_inode_dirty(handle, new.inode); 3906 3907 if (old.dir_bh) { 3908 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); 3909 if (retval) 3910 goto end_rename; 3911 } 3912 if (new.dir_bh) { 3913 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino); 3914 if (retval) 3915 goto end_rename; 3916 } 3917 ext4_update_dir_count(handle, &old); 3918 ext4_update_dir_count(handle, &new); 3919 retval = 0; 3920 3921 end_rename: 3922 brelse(old.dir_bh); 3923 brelse(new.dir_bh); 3924 brelse(old.bh); 3925 brelse(new.bh); 3926 if (handle) 3927 ext4_journal_stop(handle); 3928 return retval; 3929 } 3930 3931 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry, 3932 struct inode *new_dir, struct dentry *new_dentry, 3933 unsigned int flags) 3934 { 3935 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT)) 3936 return -EINVAL; 3937 3938 if (flags & RENAME_EXCHANGE) { 3939 return ext4_cross_rename(old_dir, old_dentry, 3940 new_dir, new_dentry); 3941 } 3942 3943 return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags); 3944 } 3945 3946 /* 3947 * directories can handle most operations... 3948 */ 3949 const struct inode_operations ext4_dir_inode_operations = { 3950 .create = ext4_create, 3951 .lookup = ext4_lookup, 3952 .link = ext4_link, 3953 .unlink = ext4_unlink, 3954 .symlink = ext4_symlink, 3955 .mkdir = ext4_mkdir, 3956 .rmdir = ext4_rmdir, 3957 .mknod = ext4_mknod, 3958 .tmpfile = ext4_tmpfile, 3959 .rename2 = ext4_rename2, 3960 .setattr = ext4_setattr, 3961 .setxattr = generic_setxattr, 3962 .getxattr = generic_getxattr, 3963 .listxattr = ext4_listxattr, 3964 .removexattr = generic_removexattr, 3965 .get_acl = ext4_get_acl, 3966 .set_acl = ext4_set_acl, 3967 .fiemap = ext4_fiemap, 3968 }; 3969 3970 const struct inode_operations ext4_special_inode_operations = { 3971 .setattr = ext4_setattr, 3972 .setxattr = generic_setxattr, 3973 .getxattr = generic_getxattr, 3974 .listxattr = ext4_listxattr, 3975 .removexattr = generic_removexattr, 3976 .get_acl = ext4_get_acl, 3977 .set_acl = ext4_set_acl, 3978 }; 3979