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/jbd2.h> 30 #include <linux/time.h> 31 #include <linux/fcntl.h> 32 #include <linux/stat.h> 33 #include <linux/string.h> 34 #include <linux/quotaops.h> 35 #include <linux/buffer_head.h> 36 #include <linux/bio.h> 37 #include "ext4.h" 38 #include "ext4_jbd2.h" 39 40 #include "xattr.h" 41 #include "acl.h" 42 43 #include <trace/events/ext4.h> 44 /* 45 * define how far ahead to read directories while searching them. 46 */ 47 #define NAMEI_RA_CHUNKS 2 48 #define NAMEI_RA_BLOCKS 4 49 #define NAMEI_RA_SIZE (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS) 50 51 static struct buffer_head *ext4_append(handle_t *handle, 52 struct inode *inode, 53 ext4_lblk_t *block) 54 { 55 struct buffer_head *bh; 56 int err = 0; 57 58 if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb && 59 ((inode->i_size >> 10) >= 60 EXT4_SB(inode->i_sb)->s_max_dir_size_kb))) 61 return ERR_PTR(-ENOSPC); 62 63 *block = inode->i_size >> inode->i_sb->s_blocksize_bits; 64 65 bh = ext4_bread(handle, inode, *block, 1, &err); 66 if (!bh) 67 return ERR_PTR(err); 68 inode->i_size += inode->i_sb->s_blocksize; 69 EXT4_I(inode)->i_disksize = inode->i_size; 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 err = 0, is_dx_block = 0; 97 98 bh = ext4_bread(NULL, inode, block, 0, &err); 99 if (!bh) { 100 if (err == 0) { 101 ext4_error_inode(inode, __func__, line, block, 102 "Directory hole found"); 103 return ERR_PTR(-EIO); 104 } 105 __ext4_warning(inode->i_sb, __func__, line, 106 "error reading directory block " 107 "(ino %lu, block %lu)", inode->i_ino, 108 (unsigned long) block); 109 return ERR_PTR(err); 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_RO_COMPAT_FEATURE(inode->i_sb, 127 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) || 128 buffer_verified(bh)) 129 return bh; 130 131 /* 132 * An empty leaf block can get mistaken for a index block; for 133 * this reason, we can only check the index checksum when the 134 * caller is sure it should be an index block. 135 */ 136 if (is_dx_block && type == INDEX) { 137 if (ext4_dx_csum_verify(inode, dirent)) 138 set_buffer_verified(bh); 139 else { 140 ext4_error_inode(inode, __func__, line, block, 141 "Directory index failed checksum"); 142 brelse(bh); 143 return ERR_PTR(-EIO); 144 } 145 } 146 if (!is_dx_block) { 147 if (ext4_dirent_csum_verify(inode, dirent)) 148 set_buffer_verified(bh); 149 else { 150 ext4_error_inode(inode, __func__, line, block, 151 "Directory block failed checksum"); 152 brelse(bh); 153 return ERR_PTR(-EIO); 154 } 155 } 156 return bh; 157 } 158 159 #ifndef assert 160 #define assert(test) J_ASSERT(test) 161 #endif 162 163 #ifdef DX_DEBUG 164 #define dxtrace(command) command 165 #else 166 #define dxtrace(command) 167 #endif 168 169 struct fake_dirent 170 { 171 __le32 inode; 172 __le16 rec_len; 173 u8 name_len; 174 u8 file_type; 175 }; 176 177 struct dx_countlimit 178 { 179 __le16 limit; 180 __le16 count; 181 }; 182 183 struct dx_entry 184 { 185 __le32 hash; 186 __le32 block; 187 }; 188 189 /* 190 * dx_root_info is laid out so that if it should somehow get overlaid by a 191 * dirent the two low bits of the hash version will be zero. Therefore, the 192 * hash version mod 4 should never be 0. Sincerely, the paranoia department. 193 */ 194 195 struct dx_root 196 { 197 struct fake_dirent dot; 198 char dot_name[4]; 199 struct fake_dirent dotdot; 200 char dotdot_name[4]; 201 struct dx_root_info 202 { 203 __le32 reserved_zero; 204 u8 hash_version; 205 u8 info_length; /* 8 */ 206 u8 indirect_levels; 207 u8 unused_flags; 208 } 209 info; 210 struct dx_entry entries[0]; 211 }; 212 213 struct dx_node 214 { 215 struct fake_dirent fake; 216 struct dx_entry entries[0]; 217 }; 218 219 220 struct dx_frame 221 { 222 struct buffer_head *bh; 223 struct dx_entry *entries; 224 struct dx_entry *at; 225 }; 226 227 struct dx_map_entry 228 { 229 u32 hash; 230 u16 offs; 231 u16 size; 232 }; 233 234 /* 235 * This goes at the end of each htree block. 236 */ 237 struct dx_tail { 238 u32 dt_reserved; 239 __le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */ 240 }; 241 242 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry); 243 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value); 244 static inline unsigned dx_get_hash(struct dx_entry *entry); 245 static void dx_set_hash(struct dx_entry *entry, unsigned value); 246 static unsigned dx_get_count(struct dx_entry *entries); 247 static unsigned dx_get_limit(struct dx_entry *entries); 248 static void dx_set_count(struct dx_entry *entries, unsigned value); 249 static void dx_set_limit(struct dx_entry *entries, unsigned value); 250 static unsigned dx_root_limit(struct inode *dir, unsigned infosize); 251 static unsigned dx_node_limit(struct inode *dir); 252 static struct dx_frame *dx_probe(const struct qstr *d_name, 253 struct inode *dir, 254 struct dx_hash_info *hinfo, 255 struct dx_frame *frame, 256 int *err); 257 static void dx_release(struct dx_frame *frames); 258 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize, 259 struct dx_hash_info *hinfo, struct dx_map_entry map[]); 260 static void dx_sort_map(struct dx_map_entry *map, unsigned count); 261 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to, 262 struct dx_map_entry *offsets, int count, unsigned blocksize); 263 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize); 264 static void dx_insert_block(struct dx_frame *frame, 265 u32 hash, ext4_lblk_t block); 266 static int ext4_htree_next_block(struct inode *dir, __u32 hash, 267 struct dx_frame *frame, 268 struct dx_frame *frames, 269 __u32 *start_hash); 270 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, 271 const struct qstr *d_name, 272 struct ext4_dir_entry_2 **res_dir, 273 int *err); 274 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry, 275 struct inode *inode); 276 277 /* checksumming functions */ 278 void initialize_dirent_tail(struct ext4_dir_entry_tail *t, 279 unsigned int blocksize) 280 { 281 memset(t, 0, sizeof(struct ext4_dir_entry_tail)); 282 t->det_rec_len = ext4_rec_len_to_disk( 283 sizeof(struct ext4_dir_entry_tail), blocksize); 284 t->det_reserved_ft = EXT4_FT_DIR_CSUM; 285 } 286 287 /* Walk through a dirent block to find a checksum "dirent" at the tail */ 288 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode, 289 struct ext4_dir_entry *de) 290 { 291 struct ext4_dir_entry_tail *t; 292 293 #ifdef PARANOID 294 struct ext4_dir_entry *d, *top; 295 296 d = de; 297 top = (struct ext4_dir_entry *)(((void *)de) + 298 (EXT4_BLOCK_SIZE(inode->i_sb) - 299 sizeof(struct ext4_dir_entry_tail))); 300 while (d < top && d->rec_len) 301 d = (struct ext4_dir_entry *)(((void *)d) + 302 le16_to_cpu(d->rec_len)); 303 304 if (d != top) 305 return NULL; 306 307 t = (struct ext4_dir_entry_tail *)d; 308 #else 309 t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb)); 310 #endif 311 312 if (t->det_reserved_zero1 || 313 le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) || 314 t->det_reserved_zero2 || 315 t->det_reserved_ft != EXT4_FT_DIR_CSUM) 316 return NULL; 317 318 return t; 319 } 320 321 static __le32 ext4_dirent_csum(struct inode *inode, 322 struct ext4_dir_entry *dirent, int size) 323 { 324 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 325 struct ext4_inode_info *ei = EXT4_I(inode); 326 __u32 csum; 327 328 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size); 329 return cpu_to_le32(csum); 330 } 331 332 static void warn_no_space_for_csum(struct inode *inode) 333 { 334 ext4_warning(inode->i_sb, "no space in directory inode %lu leaf for " 335 "checksum. Please run e2fsck -D.", inode->i_ino); 336 } 337 338 int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent) 339 { 340 struct ext4_dir_entry_tail *t; 341 342 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb, 343 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) 344 return 1; 345 346 t = get_dirent_tail(inode, dirent); 347 if (!t) { 348 warn_no_space_for_csum(inode); 349 return 0; 350 } 351 352 if (t->det_checksum != ext4_dirent_csum(inode, dirent, 353 (void *)t - (void *)dirent)) 354 return 0; 355 356 return 1; 357 } 358 359 static void ext4_dirent_csum_set(struct inode *inode, 360 struct ext4_dir_entry *dirent) 361 { 362 struct ext4_dir_entry_tail *t; 363 364 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb, 365 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) 366 return; 367 368 t = get_dirent_tail(inode, dirent); 369 if (!t) { 370 warn_no_space_for_csum(inode); 371 return; 372 } 373 374 t->det_checksum = ext4_dirent_csum(inode, dirent, 375 (void *)t - (void *)dirent); 376 } 377 378 int ext4_handle_dirty_dirent_node(handle_t *handle, 379 struct inode *inode, 380 struct buffer_head *bh) 381 { 382 ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data); 383 return ext4_handle_dirty_metadata(handle, inode, bh); 384 } 385 386 static struct dx_countlimit *get_dx_countlimit(struct inode *inode, 387 struct ext4_dir_entry *dirent, 388 int *offset) 389 { 390 struct ext4_dir_entry *dp; 391 struct dx_root_info *root; 392 int count_offset; 393 394 if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb)) 395 count_offset = 8; 396 else if (le16_to_cpu(dirent->rec_len) == 12) { 397 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12); 398 if (le16_to_cpu(dp->rec_len) != 399 EXT4_BLOCK_SIZE(inode->i_sb) - 12) 400 return NULL; 401 root = (struct dx_root_info *)(((void *)dp + 12)); 402 if (root->reserved_zero || 403 root->info_length != sizeof(struct dx_root_info)) 404 return NULL; 405 count_offset = 32; 406 } else 407 return NULL; 408 409 if (offset) 410 *offset = count_offset; 411 return (struct dx_countlimit *)(((void *)dirent) + count_offset); 412 } 413 414 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent, 415 int count_offset, int count, struct dx_tail *t) 416 { 417 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); 418 struct ext4_inode_info *ei = EXT4_I(inode); 419 __u32 csum; 420 __le32 save_csum; 421 int size; 422 423 size = count_offset + (count * sizeof(struct dx_entry)); 424 save_csum = t->dt_checksum; 425 t->dt_checksum = 0; 426 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size); 427 csum = ext4_chksum(sbi, csum, (__u8 *)t, sizeof(struct dx_tail)); 428 t->dt_checksum = save_csum; 429 430 return cpu_to_le32(csum); 431 } 432 433 static int ext4_dx_csum_verify(struct inode *inode, 434 struct ext4_dir_entry *dirent) 435 { 436 struct dx_countlimit *c; 437 struct dx_tail *t; 438 int count_offset, limit, count; 439 440 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb, 441 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) 442 return 1; 443 444 c = get_dx_countlimit(inode, dirent, &count_offset); 445 if (!c) { 446 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D."); 447 return 1; 448 } 449 limit = le16_to_cpu(c->limit); 450 count = le16_to_cpu(c->count); 451 if (count_offset + (limit * sizeof(struct dx_entry)) > 452 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) { 453 warn_no_space_for_csum(inode); 454 return 1; 455 } 456 t = (struct dx_tail *)(((struct dx_entry *)c) + limit); 457 458 if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset, 459 count, t)) 460 return 0; 461 return 1; 462 } 463 464 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent) 465 { 466 struct dx_countlimit *c; 467 struct dx_tail *t; 468 int count_offset, limit, count; 469 470 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb, 471 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) 472 return; 473 474 c = get_dx_countlimit(inode, dirent, &count_offset); 475 if (!c) { 476 EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D."); 477 return; 478 } 479 limit = le16_to_cpu(c->limit); 480 count = le16_to_cpu(c->count); 481 if (count_offset + (limit * sizeof(struct dx_entry)) > 482 EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) { 483 warn_no_space_for_csum(inode); 484 return; 485 } 486 t = (struct dx_tail *)(((struct dx_entry *)c) + limit); 487 488 t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t); 489 } 490 491 static inline int ext4_handle_dirty_dx_node(handle_t *handle, 492 struct inode *inode, 493 struct buffer_head *bh) 494 { 495 ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data); 496 return ext4_handle_dirty_metadata(handle, inode, bh); 497 } 498 499 /* 500 * p is at least 6 bytes before the end of page 501 */ 502 static inline struct ext4_dir_entry_2 * 503 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize) 504 { 505 return (struct ext4_dir_entry_2 *)((char *)p + 506 ext4_rec_len_from_disk(p->rec_len, blocksize)); 507 } 508 509 /* 510 * Future: use high four bits of block for coalesce-on-delete flags 511 * Mask them off for now. 512 */ 513 514 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry) 515 { 516 return le32_to_cpu(entry->block) & 0x00ffffff; 517 } 518 519 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value) 520 { 521 entry->block = cpu_to_le32(value); 522 } 523 524 static inline unsigned dx_get_hash(struct dx_entry *entry) 525 { 526 return le32_to_cpu(entry->hash); 527 } 528 529 static inline void dx_set_hash(struct dx_entry *entry, unsigned value) 530 { 531 entry->hash = cpu_to_le32(value); 532 } 533 534 static inline unsigned dx_get_count(struct dx_entry *entries) 535 { 536 return le16_to_cpu(((struct dx_countlimit *) entries)->count); 537 } 538 539 static inline unsigned dx_get_limit(struct dx_entry *entries) 540 { 541 return le16_to_cpu(((struct dx_countlimit *) entries)->limit); 542 } 543 544 static inline void dx_set_count(struct dx_entry *entries, unsigned value) 545 { 546 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value); 547 } 548 549 static inline void dx_set_limit(struct dx_entry *entries, unsigned value) 550 { 551 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value); 552 } 553 554 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize) 555 { 556 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) - 557 EXT4_DIR_REC_LEN(2) - infosize; 558 559 if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb, 560 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) 561 entry_space -= sizeof(struct dx_tail); 562 return entry_space / sizeof(struct dx_entry); 563 } 564 565 static inline unsigned dx_node_limit(struct inode *dir) 566 { 567 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0); 568 569 if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb, 570 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) 571 entry_space -= sizeof(struct dx_tail); 572 return entry_space / sizeof(struct dx_entry); 573 } 574 575 /* 576 * Debug 577 */ 578 #ifdef DX_DEBUG 579 static void dx_show_index(char * label, struct dx_entry *entries) 580 { 581 int i, n = dx_get_count (entries); 582 printk(KERN_DEBUG "%s index ", label); 583 for (i = 0; i < n; i++) { 584 printk("%x->%lu ", i ? dx_get_hash(entries + i) : 585 0, (unsigned long)dx_get_block(entries + i)); 586 } 587 printk("\n"); 588 } 589 590 struct stats 591 { 592 unsigned names; 593 unsigned space; 594 unsigned bcount; 595 }; 596 597 static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de, 598 int size, int show_names) 599 { 600 unsigned names = 0, space = 0; 601 char *base = (char *) de; 602 struct dx_hash_info h = *hinfo; 603 604 printk("names: "); 605 while ((char *) de < base + size) 606 { 607 if (de->inode) 608 { 609 if (show_names) 610 { 611 int len = de->name_len; 612 char *name = de->name; 613 while (len--) printk("%c", *name++); 614 ext4fs_dirhash(de->name, de->name_len, &h); 615 printk(":%x.%u ", h.hash, 616 (unsigned) ((char *) de - base)); 617 } 618 space += EXT4_DIR_REC_LEN(de->name_len); 619 names++; 620 } 621 de = ext4_next_entry(de, size); 622 } 623 printk("(%i)\n", names); 624 return (struct stats) { names, space, 1 }; 625 } 626 627 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir, 628 struct dx_entry *entries, int levels) 629 { 630 unsigned blocksize = dir->i_sb->s_blocksize; 631 unsigned count = dx_get_count(entries), names = 0, space = 0, i; 632 unsigned bcount = 0; 633 struct buffer_head *bh; 634 int err; 635 printk("%i indexed blocks...\n", count); 636 for (i = 0; i < count; i++, entries++) 637 { 638 ext4_lblk_t block = dx_get_block(entries); 639 ext4_lblk_t hash = i ? dx_get_hash(entries): 0; 640 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash; 641 struct stats stats; 642 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range); 643 if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue; 644 stats = levels? 645 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1): 646 dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0); 647 names += stats.names; 648 space += stats.space; 649 bcount += stats.bcount; 650 brelse(bh); 651 } 652 if (bcount) 653 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n", 654 levels ? "" : " ", names, space/bcount, 655 (space/bcount)*100/blocksize); 656 return (struct stats) { names, space, bcount}; 657 } 658 #endif /* DX_DEBUG */ 659 660 /* 661 * Probe for a directory leaf block to search. 662 * 663 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format 664 * error in the directory index, and the caller should fall back to 665 * searching the directory normally. The callers of dx_probe **MUST** 666 * check for this error code, and make sure it never gets reflected 667 * back to userspace. 668 */ 669 static struct dx_frame * 670 dx_probe(const struct qstr *d_name, struct inode *dir, 671 struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err) 672 { 673 unsigned count, indirect; 674 struct dx_entry *at, *entries, *p, *q, *m; 675 struct dx_root *root; 676 struct buffer_head *bh; 677 struct dx_frame *frame = frame_in; 678 u32 hash; 679 680 frame->bh = NULL; 681 bh = ext4_read_dirblock(dir, 0, INDEX); 682 if (IS_ERR(bh)) { 683 *err = PTR_ERR(bh); 684 goto fail; 685 } 686 root = (struct dx_root *) bh->b_data; 687 if (root->info.hash_version != DX_HASH_TEA && 688 root->info.hash_version != DX_HASH_HALF_MD4 && 689 root->info.hash_version != DX_HASH_LEGACY) { 690 ext4_warning(dir->i_sb, "Unrecognised inode hash code %d", 691 root->info.hash_version); 692 brelse(bh); 693 *err = ERR_BAD_DX_DIR; 694 goto fail; 695 } 696 hinfo->hash_version = root->info.hash_version; 697 if (hinfo->hash_version <= DX_HASH_TEA) 698 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; 699 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed; 700 if (d_name) 701 ext4fs_dirhash(d_name->name, d_name->len, hinfo); 702 hash = hinfo->hash; 703 704 if (root->info.unused_flags & 1) { 705 ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x", 706 root->info.unused_flags); 707 brelse(bh); 708 *err = ERR_BAD_DX_DIR; 709 goto fail; 710 } 711 712 if ((indirect = root->info.indirect_levels) > 1) { 713 ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x", 714 root->info.indirect_levels); 715 brelse(bh); 716 *err = ERR_BAD_DX_DIR; 717 goto fail; 718 } 719 720 entries = (struct dx_entry *) (((char *)&root->info) + 721 root->info.info_length); 722 723 if (dx_get_limit(entries) != dx_root_limit(dir, 724 root->info.info_length)) { 725 ext4_warning(dir->i_sb, "dx entry: limit != root limit"); 726 brelse(bh); 727 *err = ERR_BAD_DX_DIR; 728 goto fail; 729 } 730 731 dxtrace(printk("Look up %x", hash)); 732 while (1) 733 { 734 count = dx_get_count(entries); 735 if (!count || count > dx_get_limit(entries)) { 736 ext4_warning(dir->i_sb, 737 "dx entry: no count or count > limit"); 738 brelse(bh); 739 *err = ERR_BAD_DX_DIR; 740 goto fail2; 741 } 742 743 p = entries + 1; 744 q = entries + count - 1; 745 while (p <= q) 746 { 747 m = p + (q - p)/2; 748 dxtrace(printk(".")); 749 if (dx_get_hash(m) > hash) 750 q = m - 1; 751 else 752 p = m + 1; 753 } 754 755 if (0) // linear search cross check 756 { 757 unsigned n = count - 1; 758 at = entries; 759 while (n--) 760 { 761 dxtrace(printk(",")); 762 if (dx_get_hash(++at) > hash) 763 { 764 at--; 765 break; 766 } 767 } 768 assert (at == p - 1); 769 } 770 771 at = p - 1; 772 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at))); 773 frame->bh = bh; 774 frame->entries = entries; 775 frame->at = at; 776 if (!indirect--) return frame; 777 bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX); 778 if (IS_ERR(bh)) { 779 *err = PTR_ERR(bh); 780 goto fail2; 781 } 782 entries = ((struct dx_node *) bh->b_data)->entries; 783 784 if (dx_get_limit(entries) != dx_node_limit (dir)) { 785 ext4_warning(dir->i_sb, 786 "dx entry: limit != node limit"); 787 brelse(bh); 788 *err = ERR_BAD_DX_DIR; 789 goto fail2; 790 } 791 frame++; 792 frame->bh = NULL; 793 } 794 fail2: 795 while (frame >= frame_in) { 796 brelse(frame->bh); 797 frame--; 798 } 799 fail: 800 if (*err == ERR_BAD_DX_DIR) 801 ext4_warning(dir->i_sb, 802 "Corrupt dir inode %lu, running e2fsck is " 803 "recommended.", dir->i_ino); 804 return NULL; 805 } 806 807 static void dx_release (struct dx_frame *frames) 808 { 809 if (frames[0].bh == NULL) 810 return; 811 812 if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels) 813 brelse(frames[1].bh); 814 brelse(frames[0].bh); 815 } 816 817 /* 818 * This function increments the frame pointer to search the next leaf 819 * block, and reads in the necessary intervening nodes if the search 820 * should be necessary. Whether or not the search is necessary is 821 * controlled by the hash parameter. If the hash value is even, then 822 * the search is only continued if the next block starts with that 823 * hash value. This is used if we are searching for a specific file. 824 * 825 * If the hash value is HASH_NB_ALWAYS, then always go to the next block. 826 * 827 * This function returns 1 if the caller should continue to search, 828 * or 0 if it should not. If there is an error reading one of the 829 * index blocks, it will a negative error code. 830 * 831 * If start_hash is non-null, it will be filled in with the starting 832 * hash of the next page. 833 */ 834 static int ext4_htree_next_block(struct inode *dir, __u32 hash, 835 struct dx_frame *frame, 836 struct dx_frame *frames, 837 __u32 *start_hash) 838 { 839 struct dx_frame *p; 840 struct buffer_head *bh; 841 int num_frames = 0; 842 __u32 bhash; 843 844 p = frame; 845 /* 846 * Find the next leaf page by incrementing the frame pointer. 847 * If we run out of entries in the interior node, loop around and 848 * increment pointer in the parent node. When we break out of 849 * this loop, num_frames indicates the number of interior 850 * nodes need to be read. 851 */ 852 while (1) { 853 if (++(p->at) < p->entries + dx_get_count(p->entries)) 854 break; 855 if (p == frames) 856 return 0; 857 num_frames++; 858 p--; 859 } 860 861 /* 862 * If the hash is 1, then continue only if the next page has a 863 * continuation hash of any value. This is used for readdir 864 * handling. Otherwise, check to see if the hash matches the 865 * desired contiuation hash. If it doesn't, return since 866 * there's no point to read in the successive index pages. 867 */ 868 bhash = dx_get_hash(p->at); 869 if (start_hash) 870 *start_hash = bhash; 871 if ((hash & 1) == 0) { 872 if ((bhash & ~1) != hash) 873 return 0; 874 } 875 /* 876 * If the hash is HASH_NB_ALWAYS, we always go to the next 877 * block so no check is necessary 878 */ 879 while (num_frames--) { 880 bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX); 881 if (IS_ERR(bh)) 882 return PTR_ERR(bh); 883 p++; 884 brelse(p->bh); 885 p->bh = bh; 886 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries; 887 } 888 return 1; 889 } 890 891 892 /* 893 * This function fills a red-black tree with information from a 894 * directory block. It returns the number directory entries loaded 895 * into the tree. If there is an error it is returned in err. 896 */ 897 static int htree_dirblock_to_tree(struct file *dir_file, 898 struct inode *dir, ext4_lblk_t block, 899 struct dx_hash_info *hinfo, 900 __u32 start_hash, __u32 start_minor_hash) 901 { 902 struct buffer_head *bh; 903 struct ext4_dir_entry_2 *de, *top; 904 int err = 0, count = 0; 905 906 dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n", 907 (unsigned long)block)); 908 bh = ext4_read_dirblock(dir, block, DIRENT); 909 if (IS_ERR(bh)) 910 return PTR_ERR(bh); 911 912 de = (struct ext4_dir_entry_2 *) bh->b_data; 913 top = (struct ext4_dir_entry_2 *) ((char *) de + 914 dir->i_sb->s_blocksize - 915 EXT4_DIR_REC_LEN(0)); 916 for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) { 917 if (ext4_check_dir_entry(dir, NULL, de, bh, 918 bh->b_data, bh->b_size, 919 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb)) 920 + ((char *)de - bh->b_data))) { 921 /* silently ignore the rest of the block */ 922 break; 923 } 924 ext4fs_dirhash(de->name, de->name_len, hinfo); 925 if ((hinfo->hash < start_hash) || 926 ((hinfo->hash == start_hash) && 927 (hinfo->minor_hash < start_minor_hash))) 928 continue; 929 if (de->inode == 0) 930 continue; 931 if ((err = ext4_htree_store_dirent(dir_file, 932 hinfo->hash, hinfo->minor_hash, de)) != 0) { 933 brelse(bh); 934 return err; 935 } 936 count++; 937 } 938 brelse(bh); 939 return count; 940 } 941 942 943 /* 944 * This function fills a red-black tree with information from a 945 * directory. We start scanning the directory in hash order, starting 946 * at start_hash and start_minor_hash. 947 * 948 * This function returns the number of entries inserted into the tree, 949 * or a negative error code. 950 */ 951 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash, 952 __u32 start_minor_hash, __u32 *next_hash) 953 { 954 struct dx_hash_info hinfo; 955 struct ext4_dir_entry_2 *de; 956 struct dx_frame frames[2], *frame; 957 struct inode *dir; 958 ext4_lblk_t block; 959 int count = 0; 960 int ret, err; 961 __u32 hashval; 962 963 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n", 964 start_hash, start_minor_hash)); 965 dir = file_inode(dir_file); 966 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) { 967 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version; 968 if (hinfo.hash_version <= DX_HASH_TEA) 969 hinfo.hash_version += 970 EXT4_SB(dir->i_sb)->s_hash_unsigned; 971 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; 972 if (ext4_has_inline_data(dir)) { 973 int has_inline_data = 1; 974 count = htree_inlinedir_to_tree(dir_file, dir, 0, 975 &hinfo, start_hash, 976 start_minor_hash, 977 &has_inline_data); 978 if (has_inline_data) { 979 *next_hash = ~0; 980 return count; 981 } 982 } 983 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo, 984 start_hash, start_minor_hash); 985 *next_hash = ~0; 986 return count; 987 } 988 hinfo.hash = start_hash; 989 hinfo.minor_hash = 0; 990 frame = dx_probe(NULL, dir, &hinfo, frames, &err); 991 if (!frame) 992 return err; 993 994 /* Add '.' and '..' from the htree header */ 995 if (!start_hash && !start_minor_hash) { 996 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; 997 if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0) 998 goto errout; 999 count++; 1000 } 1001 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) { 1002 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; 1003 de = ext4_next_entry(de, dir->i_sb->s_blocksize); 1004 if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0) 1005 goto errout; 1006 count++; 1007 } 1008 1009 while (1) { 1010 block = dx_get_block(frame->at); 1011 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo, 1012 start_hash, start_minor_hash); 1013 if (ret < 0) { 1014 err = ret; 1015 goto errout; 1016 } 1017 count += ret; 1018 hashval = ~0; 1019 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS, 1020 frame, frames, &hashval); 1021 *next_hash = hashval; 1022 if (ret < 0) { 1023 err = ret; 1024 goto errout; 1025 } 1026 /* 1027 * Stop if: (a) there are no more entries, or 1028 * (b) we have inserted at least one entry and the 1029 * next hash value is not a continuation 1030 */ 1031 if ((ret == 0) || 1032 (count && ((hashval & 1) == 0))) 1033 break; 1034 } 1035 dx_release(frames); 1036 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, " 1037 "next hash: %x\n", count, *next_hash)); 1038 return count; 1039 errout: 1040 dx_release(frames); 1041 return (err); 1042 } 1043 1044 static inline int search_dirblock(struct buffer_head *bh, 1045 struct inode *dir, 1046 const struct qstr *d_name, 1047 unsigned int offset, 1048 struct ext4_dir_entry_2 **res_dir) 1049 { 1050 return search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir, 1051 d_name, offset, res_dir); 1052 } 1053 1054 /* 1055 * Directory block splitting, compacting 1056 */ 1057 1058 /* 1059 * Create map of hash values, offsets, and sizes, stored at end of block. 1060 * Returns number of entries mapped. 1061 */ 1062 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize, 1063 struct dx_hash_info *hinfo, 1064 struct dx_map_entry *map_tail) 1065 { 1066 int count = 0; 1067 char *base = (char *) de; 1068 struct dx_hash_info h = *hinfo; 1069 1070 while ((char *) de < base + blocksize) { 1071 if (de->name_len && de->inode) { 1072 ext4fs_dirhash(de->name, de->name_len, &h); 1073 map_tail--; 1074 map_tail->hash = h.hash; 1075 map_tail->offs = ((char *) de - base)>>2; 1076 map_tail->size = le16_to_cpu(de->rec_len); 1077 count++; 1078 cond_resched(); 1079 } 1080 /* XXX: do we need to check rec_len == 0 case? -Chris */ 1081 de = ext4_next_entry(de, blocksize); 1082 } 1083 return count; 1084 } 1085 1086 /* Sort map by hash value */ 1087 static void dx_sort_map (struct dx_map_entry *map, unsigned count) 1088 { 1089 struct dx_map_entry *p, *q, *top = map + count - 1; 1090 int more; 1091 /* Combsort until bubble sort doesn't suck */ 1092 while (count > 2) { 1093 count = count*10/13; 1094 if (count - 9 < 2) /* 9, 10 -> 11 */ 1095 count = 11; 1096 for (p = top, q = p - count; q >= map; p--, q--) 1097 if (p->hash < q->hash) 1098 swap(*p, *q); 1099 } 1100 /* Garden variety bubble sort */ 1101 do { 1102 more = 0; 1103 q = top; 1104 while (q-- > map) { 1105 if (q[1].hash >= q[0].hash) 1106 continue; 1107 swap(*(q+1), *q); 1108 more = 1; 1109 } 1110 } while(more); 1111 } 1112 1113 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block) 1114 { 1115 struct dx_entry *entries = frame->entries; 1116 struct dx_entry *old = frame->at, *new = old + 1; 1117 int count = dx_get_count(entries); 1118 1119 assert(count < dx_get_limit(entries)); 1120 assert(old < entries + count); 1121 memmove(new + 1, new, (char *)(entries + count) - (char *)(new)); 1122 dx_set_hash(new, hash); 1123 dx_set_block(new, block); 1124 dx_set_count(entries, count + 1); 1125 } 1126 1127 /* 1128 * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure. 1129 * 1130 * `len <= EXT4_NAME_LEN' is guaranteed by caller. 1131 * `de != NULL' is guaranteed by caller. 1132 */ 1133 static inline int ext4_match (int len, const char * const name, 1134 struct ext4_dir_entry_2 * de) 1135 { 1136 if (len != de->name_len) 1137 return 0; 1138 if (!de->inode) 1139 return 0; 1140 return !memcmp(name, de->name, len); 1141 } 1142 1143 /* 1144 * Returns 0 if not found, -1 on failure, and 1 on success 1145 */ 1146 int search_dir(struct buffer_head *bh, 1147 char *search_buf, 1148 int buf_size, 1149 struct inode *dir, 1150 const struct qstr *d_name, 1151 unsigned int offset, 1152 struct ext4_dir_entry_2 **res_dir) 1153 { 1154 struct ext4_dir_entry_2 * de; 1155 char * dlimit; 1156 int de_len; 1157 const char *name = d_name->name; 1158 int namelen = d_name->len; 1159 1160 de = (struct ext4_dir_entry_2 *)search_buf; 1161 dlimit = search_buf + buf_size; 1162 while ((char *) de < dlimit) { 1163 /* this code is executed quadratically often */ 1164 /* do minimal checking `by hand' */ 1165 1166 if ((char *) de + namelen <= dlimit && 1167 ext4_match (namelen, name, de)) { 1168 /* found a match - just to be sure, do a full check */ 1169 if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data, 1170 bh->b_size, offset)) 1171 return -1; 1172 *res_dir = de; 1173 return 1; 1174 } 1175 /* prevent looping on a bad block */ 1176 de_len = ext4_rec_len_from_disk(de->rec_len, 1177 dir->i_sb->s_blocksize); 1178 if (de_len <= 0) 1179 return -1; 1180 offset += de_len; 1181 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len); 1182 } 1183 return 0; 1184 } 1185 1186 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block, 1187 struct ext4_dir_entry *de) 1188 { 1189 struct super_block *sb = dir->i_sb; 1190 1191 if (!is_dx(dir)) 1192 return 0; 1193 if (block == 0) 1194 return 1; 1195 if (de->inode == 0 && 1196 ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) == 1197 sb->s_blocksize) 1198 return 1; 1199 return 0; 1200 } 1201 1202 /* 1203 * ext4_find_entry() 1204 * 1205 * finds an entry in the specified directory with the wanted name. It 1206 * returns the cache buffer in which the entry was found, and the entry 1207 * itself (as a parameter - res_dir). It does NOT read the inode of the 1208 * entry - you'll have to do that yourself if you want to. 1209 * 1210 * The returned buffer_head has ->b_count elevated. The caller is expected 1211 * to brelse() it when appropriate. 1212 */ 1213 static struct buffer_head * ext4_find_entry (struct inode *dir, 1214 const struct qstr *d_name, 1215 struct ext4_dir_entry_2 **res_dir, 1216 int *inlined) 1217 { 1218 struct super_block *sb; 1219 struct buffer_head *bh_use[NAMEI_RA_SIZE]; 1220 struct buffer_head *bh, *ret = NULL; 1221 ext4_lblk_t start, block, b; 1222 const u8 *name = d_name->name; 1223 int ra_max = 0; /* Number of bh's in the readahead 1224 buffer, bh_use[] */ 1225 int ra_ptr = 0; /* Current index into readahead 1226 buffer */ 1227 int num = 0; 1228 ext4_lblk_t nblocks; 1229 int i, err; 1230 int namelen; 1231 1232 *res_dir = NULL; 1233 sb = dir->i_sb; 1234 namelen = d_name->len; 1235 if (namelen > EXT4_NAME_LEN) 1236 return NULL; 1237 1238 if (ext4_has_inline_data(dir)) { 1239 int has_inline_data = 1; 1240 ret = ext4_find_inline_entry(dir, d_name, res_dir, 1241 &has_inline_data); 1242 if (has_inline_data) { 1243 if (inlined) 1244 *inlined = 1; 1245 return ret; 1246 } 1247 } 1248 1249 if ((namelen <= 2) && (name[0] == '.') && 1250 (name[1] == '.' || name[1] == '\0')) { 1251 /* 1252 * "." or ".." will only be in the first block 1253 * NFS may look up ".."; "." should be handled by the VFS 1254 */ 1255 block = start = 0; 1256 nblocks = 1; 1257 goto restart; 1258 } 1259 if (is_dx(dir)) { 1260 bh = ext4_dx_find_entry(dir, d_name, res_dir, &err); 1261 /* 1262 * On success, or if the error was file not found, 1263 * return. Otherwise, fall back to doing a search the 1264 * old fashioned way. 1265 */ 1266 if (bh || (err != ERR_BAD_DX_DIR)) 1267 return bh; 1268 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, " 1269 "falling back\n")); 1270 } 1271 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); 1272 start = EXT4_I(dir)->i_dir_start_lookup; 1273 if (start >= nblocks) 1274 start = 0; 1275 block = start; 1276 restart: 1277 do { 1278 /* 1279 * We deal with the read-ahead logic here. 1280 */ 1281 if (ra_ptr >= ra_max) { 1282 /* Refill the readahead buffer */ 1283 ra_ptr = 0; 1284 b = block; 1285 for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) { 1286 /* 1287 * Terminate if we reach the end of the 1288 * directory and must wrap, or if our 1289 * search has finished at this block. 1290 */ 1291 if (b >= nblocks || (num && block == start)) { 1292 bh_use[ra_max] = NULL; 1293 break; 1294 } 1295 num++; 1296 bh = ext4_getblk(NULL, dir, b++, 0, &err); 1297 bh_use[ra_max] = bh; 1298 if (bh) 1299 ll_rw_block(READ | REQ_META | REQ_PRIO, 1300 1, &bh); 1301 } 1302 } 1303 if ((bh = bh_use[ra_ptr++]) == NULL) 1304 goto next; 1305 wait_on_buffer(bh); 1306 if (!buffer_uptodate(bh)) { 1307 /* read error, skip block & hope for the best */ 1308 EXT4_ERROR_INODE(dir, "reading directory lblock %lu", 1309 (unsigned long) block); 1310 brelse(bh); 1311 goto next; 1312 } 1313 if (!buffer_verified(bh) && 1314 !is_dx_internal_node(dir, block, 1315 (struct ext4_dir_entry *)bh->b_data) && 1316 !ext4_dirent_csum_verify(dir, 1317 (struct ext4_dir_entry *)bh->b_data)) { 1318 EXT4_ERROR_INODE(dir, "checksumming directory " 1319 "block %lu", (unsigned long)block); 1320 brelse(bh); 1321 goto next; 1322 } 1323 set_buffer_verified(bh); 1324 i = search_dirblock(bh, dir, d_name, 1325 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir); 1326 if (i == 1) { 1327 EXT4_I(dir)->i_dir_start_lookup = block; 1328 ret = bh; 1329 goto cleanup_and_exit; 1330 } else { 1331 brelse(bh); 1332 if (i < 0) 1333 goto cleanup_and_exit; 1334 } 1335 next: 1336 if (++block >= nblocks) 1337 block = 0; 1338 } while (block != start); 1339 1340 /* 1341 * If the directory has grown while we were searching, then 1342 * search the last part of the directory before giving up. 1343 */ 1344 block = nblocks; 1345 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); 1346 if (block < nblocks) { 1347 start = 0; 1348 goto restart; 1349 } 1350 1351 cleanup_and_exit: 1352 /* Clean up the read-ahead blocks */ 1353 for (; ra_ptr < ra_max; ra_ptr++) 1354 brelse(bh_use[ra_ptr]); 1355 return ret; 1356 } 1357 1358 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name, 1359 struct ext4_dir_entry_2 **res_dir, int *err) 1360 { 1361 struct super_block * sb = dir->i_sb; 1362 struct dx_hash_info hinfo; 1363 struct dx_frame frames[2], *frame; 1364 struct buffer_head *bh; 1365 ext4_lblk_t block; 1366 int retval; 1367 1368 if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err))) 1369 return NULL; 1370 do { 1371 block = dx_get_block(frame->at); 1372 bh = ext4_read_dirblock(dir, block, DIRENT); 1373 if (IS_ERR(bh)) { 1374 *err = PTR_ERR(bh); 1375 goto errout; 1376 } 1377 retval = search_dirblock(bh, dir, d_name, 1378 block << EXT4_BLOCK_SIZE_BITS(sb), 1379 res_dir); 1380 if (retval == 1) { /* Success! */ 1381 dx_release(frames); 1382 return bh; 1383 } 1384 brelse(bh); 1385 if (retval == -1) { 1386 *err = ERR_BAD_DX_DIR; 1387 goto errout; 1388 } 1389 1390 /* Check to see if we should continue to search */ 1391 retval = ext4_htree_next_block(dir, hinfo.hash, frame, 1392 frames, NULL); 1393 if (retval < 0) { 1394 ext4_warning(sb, 1395 "error reading index page in directory #%lu", 1396 dir->i_ino); 1397 *err = retval; 1398 goto errout; 1399 } 1400 } while (retval == 1); 1401 1402 *err = -ENOENT; 1403 errout: 1404 dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name)); 1405 dx_release (frames); 1406 return NULL; 1407 } 1408 1409 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 1410 { 1411 struct inode *inode; 1412 struct ext4_dir_entry_2 *de; 1413 struct buffer_head *bh; 1414 1415 if (dentry->d_name.len > EXT4_NAME_LEN) 1416 return ERR_PTR(-ENAMETOOLONG); 1417 1418 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); 1419 inode = NULL; 1420 if (bh) { 1421 __u32 ino = le32_to_cpu(de->inode); 1422 brelse(bh); 1423 if (!ext4_valid_inum(dir->i_sb, ino)) { 1424 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino); 1425 return ERR_PTR(-EIO); 1426 } 1427 if (unlikely(ino == dir->i_ino)) { 1428 EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir", 1429 dentry); 1430 return ERR_PTR(-EIO); 1431 } 1432 inode = ext4_iget(dir->i_sb, ino); 1433 if (inode == ERR_PTR(-ESTALE)) { 1434 EXT4_ERROR_INODE(dir, 1435 "deleted inode referenced: %u", 1436 ino); 1437 return ERR_PTR(-EIO); 1438 } 1439 } 1440 return d_splice_alias(inode, dentry); 1441 } 1442 1443 1444 struct dentry *ext4_get_parent(struct dentry *child) 1445 { 1446 __u32 ino; 1447 static const struct qstr dotdot = QSTR_INIT("..", 2); 1448 struct ext4_dir_entry_2 * de; 1449 struct buffer_head *bh; 1450 1451 bh = ext4_find_entry(child->d_inode, &dotdot, &de, NULL); 1452 if (!bh) 1453 return ERR_PTR(-ENOENT); 1454 ino = le32_to_cpu(de->inode); 1455 brelse(bh); 1456 1457 if (!ext4_valid_inum(child->d_inode->i_sb, ino)) { 1458 EXT4_ERROR_INODE(child->d_inode, 1459 "bad parent inode number: %u", ino); 1460 return ERR_PTR(-EIO); 1461 } 1462 1463 return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino)); 1464 } 1465 1466 /* 1467 * Move count entries from end of map between two memory locations. 1468 * Returns pointer to last entry moved. 1469 */ 1470 static struct ext4_dir_entry_2 * 1471 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count, 1472 unsigned blocksize) 1473 { 1474 unsigned rec_len = 0; 1475 1476 while (count--) { 1477 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) 1478 (from + (map->offs<<2)); 1479 rec_len = EXT4_DIR_REC_LEN(de->name_len); 1480 memcpy (to, de, rec_len); 1481 ((struct ext4_dir_entry_2 *) to)->rec_len = 1482 ext4_rec_len_to_disk(rec_len, blocksize); 1483 de->inode = 0; 1484 map++; 1485 to += rec_len; 1486 } 1487 return (struct ext4_dir_entry_2 *) (to - rec_len); 1488 } 1489 1490 /* 1491 * Compact each dir entry in the range to the minimal rec_len. 1492 * Returns pointer to last entry in range. 1493 */ 1494 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize) 1495 { 1496 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base; 1497 unsigned rec_len = 0; 1498 1499 prev = to = de; 1500 while ((char*)de < base + blocksize) { 1501 next = ext4_next_entry(de, blocksize); 1502 if (de->inode && de->name_len) { 1503 rec_len = EXT4_DIR_REC_LEN(de->name_len); 1504 if (de > to) 1505 memmove(to, de, rec_len); 1506 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize); 1507 prev = to; 1508 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len); 1509 } 1510 de = next; 1511 } 1512 return prev; 1513 } 1514 1515 /* 1516 * Split a full leaf block to make room for a new dir entry. 1517 * Allocate a new block, and move entries so that they are approx. equally full. 1518 * Returns pointer to de in block into which the new entry will be inserted. 1519 */ 1520 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir, 1521 struct buffer_head **bh,struct dx_frame *frame, 1522 struct dx_hash_info *hinfo, int *error) 1523 { 1524 unsigned blocksize = dir->i_sb->s_blocksize; 1525 unsigned count, continued; 1526 struct buffer_head *bh2; 1527 ext4_lblk_t newblock; 1528 u32 hash2; 1529 struct dx_map_entry *map; 1530 char *data1 = (*bh)->b_data, *data2; 1531 unsigned split, move, size; 1532 struct ext4_dir_entry_2 *de = NULL, *de2; 1533 struct ext4_dir_entry_tail *t; 1534 int csum_size = 0; 1535 int err = 0, i; 1536 1537 if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb, 1538 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) 1539 csum_size = sizeof(struct ext4_dir_entry_tail); 1540 1541 bh2 = ext4_append(handle, dir, &newblock); 1542 if (IS_ERR(bh2)) { 1543 brelse(*bh); 1544 *bh = NULL; 1545 *error = PTR_ERR(bh2); 1546 return NULL; 1547 } 1548 1549 BUFFER_TRACE(*bh, "get_write_access"); 1550 err = ext4_journal_get_write_access(handle, *bh); 1551 if (err) 1552 goto journal_error; 1553 1554 BUFFER_TRACE(frame->bh, "get_write_access"); 1555 err = ext4_journal_get_write_access(handle, frame->bh); 1556 if (err) 1557 goto journal_error; 1558 1559 data2 = bh2->b_data; 1560 1561 /* create map in the end of data2 block */ 1562 map = (struct dx_map_entry *) (data2 + blocksize); 1563 count = dx_make_map((struct ext4_dir_entry_2 *) data1, 1564 blocksize, hinfo, map); 1565 map -= count; 1566 dx_sort_map(map, count); 1567 /* Split the existing block in the middle, size-wise */ 1568 size = 0; 1569 move = 0; 1570 for (i = count-1; i >= 0; i--) { 1571 /* is more than half of this entry in 2nd half of the block? */ 1572 if (size + map[i].size/2 > blocksize/2) 1573 break; 1574 size += map[i].size; 1575 move++; 1576 } 1577 /* map index at which we will split */ 1578 split = count - move; 1579 hash2 = map[split].hash; 1580 continued = hash2 == map[split - 1].hash; 1581 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n", 1582 (unsigned long)dx_get_block(frame->at), 1583 hash2, split, count-split)); 1584 1585 /* Fancy dance to stay within two buffers */ 1586 de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize); 1587 de = dx_pack_dirents(data1, blocksize); 1588 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) - 1589 (char *) de, 1590 blocksize); 1591 de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) - 1592 (char *) de2, 1593 blocksize); 1594 if (csum_size) { 1595 t = EXT4_DIRENT_TAIL(data2, blocksize); 1596 initialize_dirent_tail(t, blocksize); 1597 1598 t = EXT4_DIRENT_TAIL(data1, blocksize); 1599 initialize_dirent_tail(t, blocksize); 1600 } 1601 1602 dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1)); 1603 dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1)); 1604 1605 /* Which block gets the new entry? */ 1606 if (hinfo->hash >= hash2) 1607 { 1608 swap(*bh, bh2); 1609 de = de2; 1610 } 1611 dx_insert_block(frame, hash2 + continued, newblock); 1612 err = ext4_handle_dirty_dirent_node(handle, dir, bh2); 1613 if (err) 1614 goto journal_error; 1615 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 1616 if (err) 1617 goto journal_error; 1618 brelse(bh2); 1619 dxtrace(dx_show_index("frame", frame->entries)); 1620 return de; 1621 1622 journal_error: 1623 brelse(*bh); 1624 brelse(bh2); 1625 *bh = NULL; 1626 ext4_std_error(dir->i_sb, err); 1627 *error = err; 1628 return NULL; 1629 } 1630 1631 int ext4_find_dest_de(struct inode *dir, struct inode *inode, 1632 struct buffer_head *bh, 1633 void *buf, int buf_size, 1634 const char *name, int namelen, 1635 struct ext4_dir_entry_2 **dest_de) 1636 { 1637 struct ext4_dir_entry_2 *de; 1638 unsigned short reclen = EXT4_DIR_REC_LEN(namelen); 1639 int nlen, rlen; 1640 unsigned int offset = 0; 1641 char *top; 1642 1643 de = (struct ext4_dir_entry_2 *)buf; 1644 top = buf + buf_size - reclen; 1645 while ((char *) de <= top) { 1646 if (ext4_check_dir_entry(dir, NULL, de, bh, 1647 buf, buf_size, offset)) 1648 return -EIO; 1649 if (ext4_match(namelen, name, de)) 1650 return -EEXIST; 1651 nlen = EXT4_DIR_REC_LEN(de->name_len); 1652 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 1653 if ((de->inode ? rlen - nlen : rlen) >= reclen) 1654 break; 1655 de = (struct ext4_dir_entry_2 *)((char *)de + rlen); 1656 offset += rlen; 1657 } 1658 if ((char *) de > top) 1659 return -ENOSPC; 1660 1661 *dest_de = de; 1662 return 0; 1663 } 1664 1665 void ext4_insert_dentry(struct inode *inode, 1666 struct ext4_dir_entry_2 *de, 1667 int buf_size, 1668 const char *name, int namelen) 1669 { 1670 1671 int nlen, rlen; 1672 1673 nlen = EXT4_DIR_REC_LEN(de->name_len); 1674 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 1675 if (de->inode) { 1676 struct ext4_dir_entry_2 *de1 = 1677 (struct ext4_dir_entry_2 *)((char *)de + nlen); 1678 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size); 1679 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size); 1680 de = de1; 1681 } 1682 de->file_type = EXT4_FT_UNKNOWN; 1683 de->inode = cpu_to_le32(inode->i_ino); 1684 ext4_set_de_type(inode->i_sb, de, inode->i_mode); 1685 de->name_len = namelen; 1686 memcpy(de->name, name, namelen); 1687 } 1688 /* 1689 * Add a new entry into a directory (leaf) block. If de is non-NULL, 1690 * it points to a directory entry which is guaranteed to be large 1691 * enough for new directory entry. If de is NULL, then 1692 * add_dirent_to_buf will attempt search the directory block for 1693 * space. It will return -ENOSPC if no space is available, and -EIO 1694 * and -EEXIST if directory entry already exists. 1695 */ 1696 static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry, 1697 struct inode *inode, struct ext4_dir_entry_2 *de, 1698 struct buffer_head *bh) 1699 { 1700 struct inode *dir = dentry->d_parent->d_inode; 1701 const char *name = dentry->d_name.name; 1702 int namelen = dentry->d_name.len; 1703 unsigned int blocksize = dir->i_sb->s_blocksize; 1704 int csum_size = 0; 1705 int err; 1706 1707 if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb, 1708 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) 1709 csum_size = sizeof(struct ext4_dir_entry_tail); 1710 1711 if (!de) { 1712 err = ext4_find_dest_de(dir, inode, 1713 bh, bh->b_data, blocksize - csum_size, 1714 name, namelen, &de); 1715 if (err) 1716 return err; 1717 } 1718 BUFFER_TRACE(bh, "get_write_access"); 1719 err = ext4_journal_get_write_access(handle, bh); 1720 if (err) { 1721 ext4_std_error(dir->i_sb, err); 1722 return err; 1723 } 1724 1725 /* By now the buffer is marked for journaling */ 1726 ext4_insert_dentry(inode, de, blocksize, name, namelen); 1727 1728 /* 1729 * XXX shouldn't update any times until successful 1730 * completion of syscall, but too many callers depend 1731 * on this. 1732 * 1733 * XXX similarly, too many callers depend on 1734 * ext4_new_inode() setting the times, but error 1735 * recovery deletes the inode, so the worst that can 1736 * happen is that the times are slightly out of date 1737 * and/or different from the directory change time. 1738 */ 1739 dir->i_mtime = dir->i_ctime = ext4_current_time(dir); 1740 ext4_update_dx_flag(dir); 1741 dir->i_version++; 1742 ext4_mark_inode_dirty(handle, dir); 1743 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); 1744 err = ext4_handle_dirty_dirent_node(handle, dir, bh); 1745 if (err) 1746 ext4_std_error(dir->i_sb, err); 1747 return 0; 1748 } 1749 1750 /* 1751 * This converts a one block unindexed directory to a 3 block indexed 1752 * directory, and adds the dentry to the indexed directory. 1753 */ 1754 static int make_indexed_dir(handle_t *handle, struct dentry *dentry, 1755 struct inode *inode, struct buffer_head *bh) 1756 { 1757 struct inode *dir = dentry->d_parent->d_inode; 1758 const char *name = dentry->d_name.name; 1759 int namelen = dentry->d_name.len; 1760 struct buffer_head *bh2; 1761 struct dx_root *root; 1762 struct dx_frame frames[2], *frame; 1763 struct dx_entry *entries; 1764 struct ext4_dir_entry_2 *de, *de2; 1765 struct ext4_dir_entry_tail *t; 1766 char *data1, *top; 1767 unsigned len; 1768 int retval; 1769 unsigned blocksize; 1770 struct dx_hash_info hinfo; 1771 ext4_lblk_t block; 1772 struct fake_dirent *fde; 1773 int csum_size = 0; 1774 1775 if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb, 1776 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) 1777 csum_size = sizeof(struct ext4_dir_entry_tail); 1778 1779 blocksize = dir->i_sb->s_blocksize; 1780 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino)); 1781 retval = ext4_journal_get_write_access(handle, bh); 1782 if (retval) { 1783 ext4_std_error(dir->i_sb, retval); 1784 brelse(bh); 1785 return retval; 1786 } 1787 root = (struct dx_root *) bh->b_data; 1788 1789 /* The 0th block becomes the root, move the dirents out */ 1790 fde = &root->dotdot; 1791 de = (struct ext4_dir_entry_2 *)((char *)fde + 1792 ext4_rec_len_from_disk(fde->rec_len, blocksize)); 1793 if ((char *) de >= (((char *) root) + blocksize)) { 1794 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'"); 1795 brelse(bh); 1796 return -EIO; 1797 } 1798 len = ((char *) root) + (blocksize - csum_size) - (char *) de; 1799 1800 /* Allocate new block for the 0th block's dirents */ 1801 bh2 = ext4_append(handle, dir, &block); 1802 if (IS_ERR(bh2)) { 1803 brelse(bh); 1804 return PTR_ERR(bh2); 1805 } 1806 ext4_set_inode_flag(dir, EXT4_INODE_INDEX); 1807 data1 = bh2->b_data; 1808 1809 memcpy (data1, de, len); 1810 de = (struct ext4_dir_entry_2 *) data1; 1811 top = data1 + len; 1812 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top) 1813 de = de2; 1814 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) - 1815 (char *) de, 1816 blocksize); 1817 1818 if (csum_size) { 1819 t = EXT4_DIRENT_TAIL(data1, blocksize); 1820 initialize_dirent_tail(t, blocksize); 1821 } 1822 1823 /* Initialize the root; the dot dirents already exist */ 1824 de = (struct ext4_dir_entry_2 *) (&root->dotdot); 1825 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2), 1826 blocksize); 1827 memset (&root->info, 0, sizeof(root->info)); 1828 root->info.info_length = sizeof(root->info); 1829 root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version; 1830 entries = root->entries; 1831 dx_set_block(entries, 1); 1832 dx_set_count(entries, 1); 1833 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info))); 1834 1835 /* Initialize as for dx_probe */ 1836 hinfo.hash_version = root->info.hash_version; 1837 if (hinfo.hash_version <= DX_HASH_TEA) 1838 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; 1839 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; 1840 ext4fs_dirhash(name, namelen, &hinfo); 1841 frame = frames; 1842 frame->entries = entries; 1843 frame->at = entries; 1844 frame->bh = bh; 1845 bh = bh2; 1846 1847 ext4_handle_dirty_dx_node(handle, dir, frame->bh); 1848 ext4_handle_dirty_dirent_node(handle, dir, bh); 1849 1850 de = do_split(handle,dir, &bh, frame, &hinfo, &retval); 1851 if (!de) { 1852 /* 1853 * Even if the block split failed, we have to properly write 1854 * out all the changes we did so far. Otherwise we can end up 1855 * with corrupted filesystem. 1856 */ 1857 ext4_mark_inode_dirty(handle, dir); 1858 dx_release(frames); 1859 return retval; 1860 } 1861 dx_release(frames); 1862 1863 retval = add_dirent_to_buf(handle, dentry, inode, de, bh); 1864 brelse(bh); 1865 return retval; 1866 } 1867 1868 /* 1869 * ext4_add_entry() 1870 * 1871 * adds a file entry to the specified directory, using the same 1872 * semantics as ext4_find_entry(). It returns NULL if it failed. 1873 * 1874 * NOTE!! The inode part of 'de' is left at 0 - which means you 1875 * may not sleep between calling this and putting something into 1876 * the entry, as someone else might have used it while you slept. 1877 */ 1878 static int ext4_add_entry(handle_t *handle, struct dentry *dentry, 1879 struct inode *inode) 1880 { 1881 struct inode *dir = dentry->d_parent->d_inode; 1882 struct buffer_head *bh; 1883 struct ext4_dir_entry_2 *de; 1884 struct ext4_dir_entry_tail *t; 1885 struct super_block *sb; 1886 int retval; 1887 int dx_fallback=0; 1888 unsigned blocksize; 1889 ext4_lblk_t block, blocks; 1890 int csum_size = 0; 1891 1892 if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb, 1893 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) 1894 csum_size = sizeof(struct ext4_dir_entry_tail); 1895 1896 sb = dir->i_sb; 1897 blocksize = sb->s_blocksize; 1898 if (!dentry->d_name.len) 1899 return -EINVAL; 1900 1901 if (ext4_has_inline_data(dir)) { 1902 retval = ext4_try_add_inline_entry(handle, dentry, inode); 1903 if (retval < 0) 1904 return retval; 1905 if (retval == 1) { 1906 retval = 0; 1907 return retval; 1908 } 1909 } 1910 1911 if (is_dx(dir)) { 1912 retval = ext4_dx_add_entry(handle, dentry, inode); 1913 if (!retval || (retval != ERR_BAD_DX_DIR)) 1914 return retval; 1915 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX); 1916 dx_fallback++; 1917 ext4_mark_inode_dirty(handle, dir); 1918 } 1919 blocks = dir->i_size >> sb->s_blocksize_bits; 1920 for (block = 0; block < blocks; block++) { 1921 bh = ext4_read_dirblock(dir, block, DIRENT); 1922 if (IS_ERR(bh)) 1923 return PTR_ERR(bh); 1924 1925 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh); 1926 if (retval != -ENOSPC) { 1927 brelse(bh); 1928 return retval; 1929 } 1930 1931 if (blocks == 1 && !dx_fallback && 1932 EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) 1933 return make_indexed_dir(handle, dentry, inode, bh); 1934 brelse(bh); 1935 } 1936 bh = ext4_append(handle, dir, &block); 1937 if (IS_ERR(bh)) 1938 return PTR_ERR(bh); 1939 de = (struct ext4_dir_entry_2 *) bh->b_data; 1940 de->inode = 0; 1941 de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize); 1942 1943 if (csum_size) { 1944 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize); 1945 initialize_dirent_tail(t, blocksize); 1946 } 1947 1948 retval = add_dirent_to_buf(handle, dentry, inode, de, bh); 1949 brelse(bh); 1950 if (retval == 0) 1951 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY); 1952 return retval; 1953 } 1954 1955 /* 1956 * Returns 0 for success, or a negative error value 1957 */ 1958 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry, 1959 struct inode *inode) 1960 { 1961 struct dx_frame frames[2], *frame; 1962 struct dx_entry *entries, *at; 1963 struct dx_hash_info hinfo; 1964 struct buffer_head *bh; 1965 struct inode *dir = dentry->d_parent->d_inode; 1966 struct super_block *sb = dir->i_sb; 1967 struct ext4_dir_entry_2 *de; 1968 int err; 1969 1970 frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, &err); 1971 if (!frame) 1972 return err; 1973 entries = frame->entries; 1974 at = frame->at; 1975 bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT); 1976 if (IS_ERR(bh)) { 1977 err = PTR_ERR(bh); 1978 bh = NULL; 1979 goto cleanup; 1980 } 1981 1982 BUFFER_TRACE(bh, "get_write_access"); 1983 err = ext4_journal_get_write_access(handle, bh); 1984 if (err) 1985 goto journal_error; 1986 1987 err = add_dirent_to_buf(handle, dentry, inode, NULL, bh); 1988 if (err != -ENOSPC) 1989 goto cleanup; 1990 1991 /* Block full, should compress but for now just split */ 1992 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n", 1993 dx_get_count(entries), dx_get_limit(entries))); 1994 /* Need to split index? */ 1995 if (dx_get_count(entries) == dx_get_limit(entries)) { 1996 ext4_lblk_t newblock; 1997 unsigned icount = dx_get_count(entries); 1998 int levels = frame - frames; 1999 struct dx_entry *entries2; 2000 struct dx_node *node2; 2001 struct buffer_head *bh2; 2002 2003 if (levels && (dx_get_count(frames->entries) == 2004 dx_get_limit(frames->entries))) { 2005 ext4_warning(sb, "Directory index full!"); 2006 err = -ENOSPC; 2007 goto cleanup; 2008 } 2009 bh2 = ext4_append(handle, dir, &newblock); 2010 if (IS_ERR(bh2)) { 2011 err = PTR_ERR(bh2); 2012 goto cleanup; 2013 } 2014 node2 = (struct dx_node *)(bh2->b_data); 2015 entries2 = node2->entries; 2016 memset(&node2->fake, 0, sizeof(struct fake_dirent)); 2017 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize, 2018 sb->s_blocksize); 2019 BUFFER_TRACE(frame->bh, "get_write_access"); 2020 err = ext4_journal_get_write_access(handle, frame->bh); 2021 if (err) 2022 goto journal_error; 2023 if (levels) { 2024 unsigned icount1 = icount/2, icount2 = icount - icount1; 2025 unsigned hash2 = dx_get_hash(entries + icount1); 2026 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n", 2027 icount1, icount2)); 2028 2029 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */ 2030 err = ext4_journal_get_write_access(handle, 2031 frames[0].bh); 2032 if (err) 2033 goto journal_error; 2034 2035 memcpy((char *) entries2, (char *) (entries + icount1), 2036 icount2 * sizeof(struct dx_entry)); 2037 dx_set_count(entries, icount1); 2038 dx_set_count(entries2, icount2); 2039 dx_set_limit(entries2, dx_node_limit(dir)); 2040 2041 /* Which index block gets the new entry? */ 2042 if (at - entries >= icount1) { 2043 frame->at = at = at - entries - icount1 + entries2; 2044 frame->entries = entries = entries2; 2045 swap(frame->bh, bh2); 2046 } 2047 dx_insert_block(frames + 0, hash2, newblock); 2048 dxtrace(dx_show_index("node", frames[1].entries)); 2049 dxtrace(dx_show_index("node", 2050 ((struct dx_node *) bh2->b_data)->entries)); 2051 err = ext4_handle_dirty_dx_node(handle, dir, bh2); 2052 if (err) 2053 goto journal_error; 2054 brelse (bh2); 2055 } else { 2056 dxtrace(printk(KERN_DEBUG 2057 "Creating second level index...\n")); 2058 memcpy((char *) entries2, (char *) entries, 2059 icount * sizeof(struct dx_entry)); 2060 dx_set_limit(entries2, dx_node_limit(dir)); 2061 2062 /* Set up root */ 2063 dx_set_count(entries, 1); 2064 dx_set_block(entries + 0, newblock); 2065 ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1; 2066 2067 /* Add new access path frame */ 2068 frame = frames + 1; 2069 frame->at = at = at - entries + entries2; 2070 frame->entries = entries = entries2; 2071 frame->bh = bh2; 2072 err = ext4_journal_get_write_access(handle, 2073 frame->bh); 2074 if (err) 2075 goto journal_error; 2076 } 2077 err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh); 2078 if (err) { 2079 ext4_std_error(inode->i_sb, err); 2080 goto cleanup; 2081 } 2082 } 2083 de = do_split(handle, dir, &bh, frame, &hinfo, &err); 2084 if (!de) 2085 goto cleanup; 2086 err = add_dirent_to_buf(handle, dentry, inode, de, bh); 2087 goto cleanup; 2088 2089 journal_error: 2090 ext4_std_error(dir->i_sb, err); 2091 cleanup: 2092 brelse(bh); 2093 dx_release(frames); 2094 return err; 2095 } 2096 2097 /* 2098 * ext4_generic_delete_entry deletes a directory entry by merging it 2099 * with the previous entry 2100 */ 2101 int ext4_generic_delete_entry(handle_t *handle, 2102 struct inode *dir, 2103 struct ext4_dir_entry_2 *de_del, 2104 struct buffer_head *bh, 2105 void *entry_buf, 2106 int buf_size, 2107 int csum_size) 2108 { 2109 struct ext4_dir_entry_2 *de, *pde; 2110 unsigned int blocksize = dir->i_sb->s_blocksize; 2111 int i; 2112 2113 i = 0; 2114 pde = NULL; 2115 de = (struct ext4_dir_entry_2 *)entry_buf; 2116 while (i < buf_size - csum_size) { 2117 if (ext4_check_dir_entry(dir, NULL, de, bh, 2118 bh->b_data, bh->b_size, i)) 2119 return -EIO; 2120 if (de == de_del) { 2121 if (pde) 2122 pde->rec_len = ext4_rec_len_to_disk( 2123 ext4_rec_len_from_disk(pde->rec_len, 2124 blocksize) + 2125 ext4_rec_len_from_disk(de->rec_len, 2126 blocksize), 2127 blocksize); 2128 else 2129 de->inode = 0; 2130 dir->i_version++; 2131 return 0; 2132 } 2133 i += ext4_rec_len_from_disk(de->rec_len, blocksize); 2134 pde = de; 2135 de = ext4_next_entry(de, blocksize); 2136 } 2137 return -ENOENT; 2138 } 2139 2140 static int ext4_delete_entry(handle_t *handle, 2141 struct inode *dir, 2142 struct ext4_dir_entry_2 *de_del, 2143 struct buffer_head *bh) 2144 { 2145 int err, csum_size = 0; 2146 2147 if (ext4_has_inline_data(dir)) { 2148 int has_inline_data = 1; 2149 err = ext4_delete_inline_entry(handle, dir, de_del, bh, 2150 &has_inline_data); 2151 if (has_inline_data) 2152 return err; 2153 } 2154 2155 if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb, 2156 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) 2157 csum_size = sizeof(struct ext4_dir_entry_tail); 2158 2159 BUFFER_TRACE(bh, "get_write_access"); 2160 err = ext4_journal_get_write_access(handle, bh); 2161 if (unlikely(err)) 2162 goto out; 2163 2164 err = ext4_generic_delete_entry(handle, dir, de_del, 2165 bh, bh->b_data, 2166 dir->i_sb->s_blocksize, csum_size); 2167 if (err) 2168 goto out; 2169 2170 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); 2171 err = ext4_handle_dirty_dirent_node(handle, dir, bh); 2172 if (unlikely(err)) 2173 goto out; 2174 2175 return 0; 2176 out: 2177 if (err != -ENOENT) 2178 ext4_std_error(dir->i_sb, err); 2179 return err; 2180 } 2181 2182 /* 2183 * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2, 2184 * since this indicates that nlinks count was previously 1. 2185 */ 2186 static void ext4_inc_count(handle_t *handle, struct inode *inode) 2187 { 2188 inc_nlink(inode); 2189 if (is_dx(inode) && inode->i_nlink > 1) { 2190 /* limit is 16-bit i_links_count */ 2191 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) { 2192 set_nlink(inode, 1); 2193 EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb, 2194 EXT4_FEATURE_RO_COMPAT_DIR_NLINK); 2195 } 2196 } 2197 } 2198 2199 /* 2200 * If a directory had nlink == 1, then we should let it be 1. This indicates 2201 * directory has >EXT4_LINK_MAX subdirs. 2202 */ 2203 static void ext4_dec_count(handle_t *handle, struct inode *inode) 2204 { 2205 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2) 2206 drop_nlink(inode); 2207 } 2208 2209 2210 static int ext4_add_nondir(handle_t *handle, 2211 struct dentry *dentry, struct inode *inode) 2212 { 2213 int err = ext4_add_entry(handle, dentry, inode); 2214 if (!err) { 2215 ext4_mark_inode_dirty(handle, inode); 2216 unlock_new_inode(inode); 2217 d_instantiate(dentry, inode); 2218 return 0; 2219 } 2220 drop_nlink(inode); 2221 unlock_new_inode(inode); 2222 iput(inode); 2223 return err; 2224 } 2225 2226 /* 2227 * By the time this is called, we already have created 2228 * the directory cache entry for the new file, but it 2229 * is so far negative - it has no inode. 2230 * 2231 * If the create succeeds, we fill in the inode information 2232 * with d_instantiate(). 2233 */ 2234 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode, 2235 bool excl) 2236 { 2237 handle_t *handle; 2238 struct inode *inode; 2239 int err, credits, retries = 0; 2240 2241 dquot_initialize(dir); 2242 2243 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2244 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2245 retry: 2246 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0, 2247 NULL, EXT4_HT_DIR, credits); 2248 handle = ext4_journal_current_handle(); 2249 err = PTR_ERR(inode); 2250 if (!IS_ERR(inode)) { 2251 inode->i_op = &ext4_file_inode_operations; 2252 inode->i_fop = &ext4_file_operations; 2253 ext4_set_aops(inode); 2254 err = ext4_add_nondir(handle, dentry, inode); 2255 if (!err && IS_DIRSYNC(dir)) 2256 ext4_handle_sync(handle); 2257 } 2258 if (handle) 2259 ext4_journal_stop(handle); 2260 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2261 goto retry; 2262 return err; 2263 } 2264 2265 static int ext4_mknod(struct inode *dir, struct dentry *dentry, 2266 umode_t mode, dev_t rdev) 2267 { 2268 handle_t *handle; 2269 struct inode *inode; 2270 int err, credits, retries = 0; 2271 2272 if (!new_valid_dev(rdev)) 2273 return -EINVAL; 2274 2275 dquot_initialize(dir); 2276 2277 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2278 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2279 retry: 2280 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0, 2281 NULL, EXT4_HT_DIR, credits); 2282 handle = ext4_journal_current_handle(); 2283 err = PTR_ERR(inode); 2284 if (!IS_ERR(inode)) { 2285 init_special_inode(inode, inode->i_mode, rdev); 2286 inode->i_op = &ext4_special_inode_operations; 2287 err = ext4_add_nondir(handle, dentry, inode); 2288 if (!err && IS_DIRSYNC(dir)) 2289 ext4_handle_sync(handle); 2290 } 2291 if (handle) 2292 ext4_journal_stop(handle); 2293 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2294 goto retry; 2295 return err; 2296 } 2297 2298 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) 2299 { 2300 handle_t *handle; 2301 struct inode *inode; 2302 int err, retries = 0; 2303 2304 dquot_initialize(dir); 2305 2306 retry: 2307 inode = ext4_new_inode_start_handle(dir, mode, 2308 NULL, 0, NULL, 2309 EXT4_HT_DIR, 2310 EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) + 2311 4 + EXT4_XATTR_TRANS_BLOCKS); 2312 handle = ext4_journal_current_handle(); 2313 err = PTR_ERR(inode); 2314 if (!IS_ERR(inode)) { 2315 inode->i_op = &ext4_file_inode_operations; 2316 inode->i_fop = &ext4_file_operations; 2317 ext4_set_aops(inode); 2318 d_tmpfile(dentry, inode); 2319 err = ext4_orphan_add(handle, inode); 2320 if (err) 2321 goto err_unlock_inode; 2322 mark_inode_dirty(inode); 2323 unlock_new_inode(inode); 2324 } 2325 if (handle) 2326 ext4_journal_stop(handle); 2327 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2328 goto retry; 2329 return err; 2330 err_unlock_inode: 2331 ext4_journal_stop(handle); 2332 unlock_new_inode(inode); 2333 return err; 2334 } 2335 2336 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode, 2337 struct ext4_dir_entry_2 *de, 2338 int blocksize, int csum_size, 2339 unsigned int parent_ino, int dotdot_real_len) 2340 { 2341 de->inode = cpu_to_le32(inode->i_ino); 2342 de->name_len = 1; 2343 de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len), 2344 blocksize); 2345 strcpy(de->name, "."); 2346 ext4_set_de_type(inode->i_sb, de, S_IFDIR); 2347 2348 de = ext4_next_entry(de, blocksize); 2349 de->inode = cpu_to_le32(parent_ino); 2350 de->name_len = 2; 2351 if (!dotdot_real_len) 2352 de->rec_len = ext4_rec_len_to_disk(blocksize - 2353 (csum_size + EXT4_DIR_REC_LEN(1)), 2354 blocksize); 2355 else 2356 de->rec_len = ext4_rec_len_to_disk( 2357 EXT4_DIR_REC_LEN(de->name_len), blocksize); 2358 strcpy(de->name, ".."); 2359 ext4_set_de_type(inode->i_sb, de, S_IFDIR); 2360 2361 return ext4_next_entry(de, blocksize); 2362 } 2363 2364 static int ext4_init_new_dir(handle_t *handle, struct inode *dir, 2365 struct inode *inode) 2366 { 2367 struct buffer_head *dir_block = NULL; 2368 struct ext4_dir_entry_2 *de; 2369 struct ext4_dir_entry_tail *t; 2370 ext4_lblk_t block = 0; 2371 unsigned int blocksize = dir->i_sb->s_blocksize; 2372 int csum_size = 0; 2373 int err; 2374 2375 if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb, 2376 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) 2377 csum_size = sizeof(struct ext4_dir_entry_tail); 2378 2379 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) { 2380 err = ext4_try_create_inline_dir(handle, dir, inode); 2381 if (err < 0 && err != -ENOSPC) 2382 goto out; 2383 if (!err) 2384 goto out; 2385 } 2386 2387 inode->i_size = 0; 2388 dir_block = ext4_append(handle, inode, &block); 2389 if (IS_ERR(dir_block)) 2390 return PTR_ERR(dir_block); 2391 BUFFER_TRACE(dir_block, "get_write_access"); 2392 err = ext4_journal_get_write_access(handle, dir_block); 2393 if (err) 2394 goto out; 2395 de = (struct ext4_dir_entry_2 *)dir_block->b_data; 2396 ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0); 2397 set_nlink(inode, 2); 2398 if (csum_size) { 2399 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize); 2400 initialize_dirent_tail(t, blocksize); 2401 } 2402 2403 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata"); 2404 err = ext4_handle_dirty_dirent_node(handle, inode, dir_block); 2405 if (err) 2406 goto out; 2407 set_buffer_verified(dir_block); 2408 out: 2409 brelse(dir_block); 2410 return err; 2411 } 2412 2413 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) 2414 { 2415 handle_t *handle; 2416 struct inode *inode; 2417 int err, credits, retries = 0; 2418 2419 if (EXT4_DIR_LINK_MAX(dir)) 2420 return -EMLINK; 2421 2422 dquot_initialize(dir); 2423 2424 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2425 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2426 retry: 2427 inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode, 2428 &dentry->d_name, 2429 0, NULL, EXT4_HT_DIR, credits); 2430 handle = ext4_journal_current_handle(); 2431 err = PTR_ERR(inode); 2432 if (IS_ERR(inode)) 2433 goto out_stop; 2434 2435 inode->i_op = &ext4_dir_inode_operations; 2436 inode->i_fop = &ext4_dir_operations; 2437 err = ext4_init_new_dir(handle, dir, inode); 2438 if (err) 2439 goto out_clear_inode; 2440 err = ext4_mark_inode_dirty(handle, inode); 2441 if (!err) 2442 err = ext4_add_entry(handle, dentry, inode); 2443 if (err) { 2444 out_clear_inode: 2445 clear_nlink(inode); 2446 unlock_new_inode(inode); 2447 ext4_mark_inode_dirty(handle, inode); 2448 iput(inode); 2449 goto out_stop; 2450 } 2451 ext4_inc_count(handle, dir); 2452 ext4_update_dx_flag(dir); 2453 err = ext4_mark_inode_dirty(handle, dir); 2454 if (err) 2455 goto out_clear_inode; 2456 unlock_new_inode(inode); 2457 d_instantiate(dentry, inode); 2458 if (IS_DIRSYNC(dir)) 2459 ext4_handle_sync(handle); 2460 2461 out_stop: 2462 if (handle) 2463 ext4_journal_stop(handle); 2464 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2465 goto retry; 2466 return err; 2467 } 2468 2469 /* 2470 * routine to check that the specified directory is empty (for rmdir) 2471 */ 2472 static int empty_dir(struct inode *inode) 2473 { 2474 unsigned int offset; 2475 struct buffer_head *bh; 2476 struct ext4_dir_entry_2 *de, *de1; 2477 struct super_block *sb; 2478 int err = 0; 2479 2480 if (ext4_has_inline_data(inode)) { 2481 int has_inline_data = 1; 2482 2483 err = empty_inline_dir(inode, &has_inline_data); 2484 if (has_inline_data) 2485 return err; 2486 } 2487 2488 sb = inode->i_sb; 2489 if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) { 2490 EXT4_ERROR_INODE(inode, "invalid size"); 2491 return 1; 2492 } 2493 bh = ext4_read_dirblock(inode, 0, EITHER); 2494 if (IS_ERR(bh)) 2495 return 1; 2496 2497 de = (struct ext4_dir_entry_2 *) bh->b_data; 2498 de1 = ext4_next_entry(de, sb->s_blocksize); 2499 if (le32_to_cpu(de->inode) != inode->i_ino || 2500 !le32_to_cpu(de1->inode) || 2501 strcmp(".", de->name) || 2502 strcmp("..", de1->name)) { 2503 ext4_warning(inode->i_sb, 2504 "bad directory (dir #%lu) - no `.' or `..'", 2505 inode->i_ino); 2506 brelse(bh); 2507 return 1; 2508 } 2509 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) + 2510 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize); 2511 de = ext4_next_entry(de1, sb->s_blocksize); 2512 while (offset < inode->i_size) { 2513 if (!bh || 2514 (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) { 2515 unsigned int lblock; 2516 err = 0; 2517 brelse(bh); 2518 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb); 2519 bh = ext4_read_dirblock(inode, lblock, EITHER); 2520 if (IS_ERR(bh)) 2521 return 1; 2522 de = (struct ext4_dir_entry_2 *) bh->b_data; 2523 } 2524 if (ext4_check_dir_entry(inode, NULL, de, bh, 2525 bh->b_data, bh->b_size, offset)) { 2526 de = (struct ext4_dir_entry_2 *)(bh->b_data + 2527 sb->s_blocksize); 2528 offset = (offset | (sb->s_blocksize - 1)) + 1; 2529 continue; 2530 } 2531 if (le32_to_cpu(de->inode)) { 2532 brelse(bh); 2533 return 0; 2534 } 2535 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); 2536 de = ext4_next_entry(de, sb->s_blocksize); 2537 } 2538 brelse(bh); 2539 return 1; 2540 } 2541 2542 /* ext4_orphan_add() links an unlinked or truncated inode into a list of 2543 * such inodes, starting at the superblock, in case we crash before the 2544 * file is closed/deleted, or in case the inode truncate spans multiple 2545 * transactions and the last transaction is not recovered after a crash. 2546 * 2547 * At filesystem recovery time, we walk this list deleting unlinked 2548 * inodes and truncating linked inodes in ext4_orphan_cleanup(). 2549 */ 2550 int ext4_orphan_add(handle_t *handle, struct inode *inode) 2551 { 2552 struct super_block *sb = inode->i_sb; 2553 struct ext4_iloc iloc; 2554 int err = 0, rc; 2555 2556 if (!EXT4_SB(sb)->s_journal) 2557 return 0; 2558 2559 mutex_lock(&EXT4_SB(sb)->s_orphan_lock); 2560 if (!list_empty(&EXT4_I(inode)->i_orphan)) 2561 goto out_unlock; 2562 2563 /* 2564 * Orphan handling is only valid for files with data blocks 2565 * being truncated, or files being unlinked. Note that we either 2566 * hold i_mutex, or the inode can not be referenced from outside, 2567 * so i_nlink should not be bumped due to race 2568 */ 2569 J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 2570 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0); 2571 2572 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access"); 2573 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh); 2574 if (err) 2575 goto out_unlock; 2576 2577 err = ext4_reserve_inode_write(handle, inode, &iloc); 2578 if (err) 2579 goto out_unlock; 2580 /* 2581 * Due to previous errors inode may be already a part of on-disk 2582 * orphan list. If so skip on-disk list modification. 2583 */ 2584 if (NEXT_ORPHAN(inode) && NEXT_ORPHAN(inode) <= 2585 (le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))) 2586 goto mem_insert; 2587 2588 /* Insert this inode at the head of the on-disk orphan list... */ 2589 NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan); 2590 EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino); 2591 err = ext4_handle_dirty_super(handle, sb); 2592 rc = ext4_mark_iloc_dirty(handle, inode, &iloc); 2593 if (!err) 2594 err = rc; 2595 2596 /* Only add to the head of the in-memory list if all the 2597 * previous operations succeeded. If the orphan_add is going to 2598 * fail (possibly taking the journal offline), we can't risk 2599 * leaving the inode on the orphan list: stray orphan-list 2600 * entries can cause panics at unmount time. 2601 * 2602 * This is safe: on error we're going to ignore the orphan list 2603 * anyway on the next recovery. */ 2604 mem_insert: 2605 if (!err) 2606 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan); 2607 2608 jbd_debug(4, "superblock will point to %lu\n", inode->i_ino); 2609 jbd_debug(4, "orphan inode %lu will point to %d\n", 2610 inode->i_ino, NEXT_ORPHAN(inode)); 2611 out_unlock: 2612 mutex_unlock(&EXT4_SB(sb)->s_orphan_lock); 2613 ext4_std_error(inode->i_sb, err); 2614 return err; 2615 } 2616 2617 /* 2618 * ext4_orphan_del() removes an unlinked or truncated inode from the list 2619 * of such inodes stored on disk, because it is finally being cleaned up. 2620 */ 2621 int ext4_orphan_del(handle_t *handle, struct inode *inode) 2622 { 2623 struct list_head *prev; 2624 struct ext4_inode_info *ei = EXT4_I(inode); 2625 struct ext4_sb_info *sbi; 2626 __u32 ino_next; 2627 struct ext4_iloc iloc; 2628 int err = 0; 2629 2630 if ((!EXT4_SB(inode->i_sb)->s_journal) && 2631 !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) 2632 return 0; 2633 2634 mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock); 2635 if (list_empty(&ei->i_orphan)) 2636 goto out; 2637 2638 ino_next = NEXT_ORPHAN(inode); 2639 prev = ei->i_orphan.prev; 2640 sbi = EXT4_SB(inode->i_sb); 2641 2642 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino); 2643 2644 list_del_init(&ei->i_orphan); 2645 2646 /* If we're on an error path, we may not have a valid 2647 * transaction handle with which to update the orphan list on 2648 * disk, but we still need to remove the inode from the linked 2649 * list in memory. */ 2650 if (!handle) 2651 goto out; 2652 2653 err = ext4_reserve_inode_write(handle, inode, &iloc); 2654 if (err) 2655 goto out_err; 2656 2657 if (prev == &sbi->s_orphan) { 2658 jbd_debug(4, "superblock will point to %u\n", ino_next); 2659 BUFFER_TRACE(sbi->s_sbh, "get_write_access"); 2660 err = ext4_journal_get_write_access(handle, sbi->s_sbh); 2661 if (err) 2662 goto out_brelse; 2663 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next); 2664 err = ext4_handle_dirty_super(handle, inode->i_sb); 2665 } else { 2666 struct ext4_iloc iloc2; 2667 struct inode *i_prev = 2668 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode; 2669 2670 jbd_debug(4, "orphan inode %lu will point to %u\n", 2671 i_prev->i_ino, ino_next); 2672 err = ext4_reserve_inode_write(handle, i_prev, &iloc2); 2673 if (err) 2674 goto out_brelse; 2675 NEXT_ORPHAN(i_prev) = ino_next; 2676 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2); 2677 } 2678 if (err) 2679 goto out_brelse; 2680 NEXT_ORPHAN(inode) = 0; 2681 err = ext4_mark_iloc_dirty(handle, inode, &iloc); 2682 2683 out_err: 2684 ext4_std_error(inode->i_sb, err); 2685 out: 2686 mutex_unlock(&EXT4_SB(inode->i_sb)->s_orphan_lock); 2687 return err; 2688 2689 out_brelse: 2690 brelse(iloc.bh); 2691 goto out_err; 2692 } 2693 2694 static int ext4_rmdir(struct inode *dir, struct dentry *dentry) 2695 { 2696 int retval; 2697 struct inode *inode; 2698 struct buffer_head *bh; 2699 struct ext4_dir_entry_2 *de; 2700 handle_t *handle = NULL; 2701 2702 /* Initialize quotas before so that eventual writes go in 2703 * separate transaction */ 2704 dquot_initialize(dir); 2705 dquot_initialize(dentry->d_inode); 2706 2707 retval = -ENOENT; 2708 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); 2709 if (!bh) 2710 goto end_rmdir; 2711 2712 inode = dentry->d_inode; 2713 2714 retval = -EIO; 2715 if (le32_to_cpu(de->inode) != inode->i_ino) 2716 goto end_rmdir; 2717 2718 retval = -ENOTEMPTY; 2719 if (!empty_dir(inode)) 2720 goto end_rmdir; 2721 2722 handle = ext4_journal_start(dir, EXT4_HT_DIR, 2723 EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); 2724 if (IS_ERR(handle)) { 2725 retval = PTR_ERR(handle); 2726 handle = NULL; 2727 goto end_rmdir; 2728 } 2729 2730 if (IS_DIRSYNC(dir)) 2731 ext4_handle_sync(handle); 2732 2733 retval = ext4_delete_entry(handle, dir, de, bh); 2734 if (retval) 2735 goto end_rmdir; 2736 if (!EXT4_DIR_LINK_EMPTY(inode)) 2737 ext4_warning(inode->i_sb, 2738 "empty directory has too many links (%d)", 2739 inode->i_nlink); 2740 inode->i_version++; 2741 clear_nlink(inode); 2742 /* There's no need to set i_disksize: the fact that i_nlink is 2743 * zero will ensure that the right thing happens during any 2744 * recovery. */ 2745 inode->i_size = 0; 2746 ext4_orphan_add(handle, inode); 2747 inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode); 2748 ext4_mark_inode_dirty(handle, inode); 2749 ext4_dec_count(handle, dir); 2750 ext4_update_dx_flag(dir); 2751 ext4_mark_inode_dirty(handle, dir); 2752 2753 end_rmdir: 2754 brelse(bh); 2755 if (handle) 2756 ext4_journal_stop(handle); 2757 return retval; 2758 } 2759 2760 static int ext4_unlink(struct inode *dir, struct dentry *dentry) 2761 { 2762 int retval; 2763 struct inode *inode; 2764 struct buffer_head *bh; 2765 struct ext4_dir_entry_2 *de; 2766 handle_t *handle = NULL; 2767 2768 trace_ext4_unlink_enter(dir, dentry); 2769 /* Initialize quotas before so that eventual writes go 2770 * in separate transaction */ 2771 dquot_initialize(dir); 2772 dquot_initialize(dentry->d_inode); 2773 2774 retval = -ENOENT; 2775 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); 2776 if (!bh) 2777 goto end_unlink; 2778 2779 inode = dentry->d_inode; 2780 2781 retval = -EIO; 2782 if (le32_to_cpu(de->inode) != inode->i_ino) 2783 goto end_unlink; 2784 2785 handle = ext4_journal_start(dir, EXT4_HT_DIR, 2786 EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); 2787 if (IS_ERR(handle)) { 2788 retval = PTR_ERR(handle); 2789 handle = NULL; 2790 goto end_unlink; 2791 } 2792 2793 if (IS_DIRSYNC(dir)) 2794 ext4_handle_sync(handle); 2795 2796 if (!inode->i_nlink) { 2797 ext4_warning(inode->i_sb, 2798 "Deleting nonexistent file (%lu), %d", 2799 inode->i_ino, inode->i_nlink); 2800 set_nlink(inode, 1); 2801 } 2802 retval = ext4_delete_entry(handle, dir, de, bh); 2803 if (retval) 2804 goto end_unlink; 2805 dir->i_ctime = dir->i_mtime = ext4_current_time(dir); 2806 ext4_update_dx_flag(dir); 2807 ext4_mark_inode_dirty(handle, dir); 2808 drop_nlink(inode); 2809 if (!inode->i_nlink) 2810 ext4_orphan_add(handle, inode); 2811 inode->i_ctime = ext4_current_time(inode); 2812 ext4_mark_inode_dirty(handle, inode); 2813 retval = 0; 2814 2815 end_unlink: 2816 brelse(bh); 2817 if (handle) 2818 ext4_journal_stop(handle); 2819 trace_ext4_unlink_exit(dentry, retval); 2820 return retval; 2821 } 2822 2823 static int ext4_symlink(struct inode *dir, 2824 struct dentry *dentry, const char *symname) 2825 { 2826 handle_t *handle; 2827 struct inode *inode; 2828 int l, err, retries = 0; 2829 int credits; 2830 2831 l = strlen(symname)+1; 2832 if (l > dir->i_sb->s_blocksize) 2833 return -ENAMETOOLONG; 2834 2835 dquot_initialize(dir); 2836 2837 if (l > EXT4_N_BLOCKS * 4) { 2838 /* 2839 * For non-fast symlinks, we just allocate inode and put it on 2840 * orphan list in the first transaction => we need bitmap, 2841 * group descriptor, sb, inode block, quota blocks, and 2842 * possibly selinux xattr blocks. 2843 */ 2844 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) + 2845 EXT4_XATTR_TRANS_BLOCKS; 2846 } else { 2847 /* 2848 * Fast symlink. We have to add entry to directory 2849 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS), 2850 * allocate new inode (bitmap, group descriptor, inode block, 2851 * quota blocks, sb is already counted in previous macros). 2852 */ 2853 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2854 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3; 2855 } 2856 retry: 2857 inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO, 2858 &dentry->d_name, 0, NULL, 2859 EXT4_HT_DIR, credits); 2860 handle = ext4_journal_current_handle(); 2861 err = PTR_ERR(inode); 2862 if (IS_ERR(inode)) 2863 goto out_stop; 2864 2865 if (l > EXT4_N_BLOCKS * 4) { 2866 inode->i_op = &ext4_symlink_inode_operations; 2867 ext4_set_aops(inode); 2868 /* 2869 * We cannot call page_symlink() with transaction started 2870 * because it calls into ext4_write_begin() which can wait 2871 * for transaction commit if we are running out of space 2872 * and thus we deadlock. So we have to stop transaction now 2873 * and restart it when symlink contents is written. 2874 * 2875 * To keep fs consistent in case of crash, we have to put inode 2876 * to orphan list in the mean time. 2877 */ 2878 drop_nlink(inode); 2879 err = ext4_orphan_add(handle, inode); 2880 ext4_journal_stop(handle); 2881 if (err) 2882 goto err_drop_inode; 2883 err = __page_symlink(inode, symname, l, 1); 2884 if (err) 2885 goto err_drop_inode; 2886 /* 2887 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS 2888 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified 2889 */ 2890 handle = ext4_journal_start(dir, EXT4_HT_DIR, 2891 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2892 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1); 2893 if (IS_ERR(handle)) { 2894 err = PTR_ERR(handle); 2895 goto err_drop_inode; 2896 } 2897 set_nlink(inode, 1); 2898 err = ext4_orphan_del(handle, inode); 2899 if (err) { 2900 ext4_journal_stop(handle); 2901 clear_nlink(inode); 2902 goto err_drop_inode; 2903 } 2904 } else { 2905 /* clear the extent format for fast symlink */ 2906 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS); 2907 inode->i_op = &ext4_fast_symlink_inode_operations; 2908 memcpy((char *)&EXT4_I(inode)->i_data, symname, l); 2909 inode->i_size = l-1; 2910 } 2911 EXT4_I(inode)->i_disksize = inode->i_size; 2912 err = ext4_add_nondir(handle, dentry, inode); 2913 if (!err && IS_DIRSYNC(dir)) 2914 ext4_handle_sync(handle); 2915 2916 out_stop: 2917 if (handle) 2918 ext4_journal_stop(handle); 2919 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2920 goto retry; 2921 return err; 2922 err_drop_inode: 2923 unlock_new_inode(inode); 2924 iput(inode); 2925 return err; 2926 } 2927 2928 static int ext4_link(struct dentry *old_dentry, 2929 struct inode *dir, struct dentry *dentry) 2930 { 2931 handle_t *handle; 2932 struct inode *inode = old_dentry->d_inode; 2933 int err, retries = 0; 2934 2935 if (inode->i_nlink >= EXT4_LINK_MAX) 2936 return -EMLINK; 2937 2938 dquot_initialize(dir); 2939 2940 retry: 2941 handle = ext4_journal_start(dir, EXT4_HT_DIR, 2942 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2943 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1); 2944 if (IS_ERR(handle)) 2945 return PTR_ERR(handle); 2946 2947 if (IS_DIRSYNC(dir)) 2948 ext4_handle_sync(handle); 2949 2950 inode->i_ctime = ext4_current_time(inode); 2951 ext4_inc_count(handle, inode); 2952 ihold(inode); 2953 2954 err = ext4_add_entry(handle, dentry, inode); 2955 if (!err) { 2956 ext4_mark_inode_dirty(handle, inode); 2957 /* this can happen only for tmpfile being 2958 * linked the first time 2959 */ 2960 if (inode->i_nlink == 1) 2961 ext4_orphan_del(handle, inode); 2962 d_instantiate(dentry, inode); 2963 } else { 2964 drop_nlink(inode); 2965 iput(inode); 2966 } 2967 ext4_journal_stop(handle); 2968 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2969 goto retry; 2970 return err; 2971 } 2972 2973 2974 /* 2975 * Try to find buffer head where contains the parent block. 2976 * It should be the inode block if it is inlined or the 1st block 2977 * if it is a normal dir. 2978 */ 2979 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle, 2980 struct inode *inode, 2981 int *retval, 2982 struct ext4_dir_entry_2 **parent_de, 2983 int *inlined) 2984 { 2985 struct buffer_head *bh; 2986 2987 if (!ext4_has_inline_data(inode)) { 2988 bh = ext4_read_dirblock(inode, 0, EITHER); 2989 if (IS_ERR(bh)) { 2990 *retval = PTR_ERR(bh); 2991 return NULL; 2992 } 2993 *parent_de = ext4_next_entry( 2994 (struct ext4_dir_entry_2 *)bh->b_data, 2995 inode->i_sb->s_blocksize); 2996 return bh; 2997 } 2998 2999 *inlined = 1; 3000 return ext4_get_first_inline_block(inode, parent_de, retval); 3001 } 3002 3003 struct ext4_renament { 3004 struct inode *dir; 3005 struct dentry *dentry; 3006 struct inode *inode; 3007 bool is_dir; 3008 int dir_nlink_delta; 3009 3010 /* entry for "dentry" */ 3011 struct buffer_head *bh; 3012 struct ext4_dir_entry_2 *de; 3013 int inlined; 3014 3015 /* entry for ".." in inode if it's a directory */ 3016 struct buffer_head *dir_bh; 3017 struct ext4_dir_entry_2 *parent_de; 3018 int dir_inlined; 3019 }; 3020 3021 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent) 3022 { 3023 int retval; 3024 3025 ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode, 3026 &retval, &ent->parent_de, 3027 &ent->dir_inlined); 3028 if (!ent->dir_bh) 3029 return retval; 3030 if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino) 3031 return -EIO; 3032 BUFFER_TRACE(ent->dir_bh, "get_write_access"); 3033 return ext4_journal_get_write_access(handle, ent->dir_bh); 3034 } 3035 3036 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent, 3037 unsigned dir_ino) 3038 { 3039 int retval; 3040 3041 ent->parent_de->inode = cpu_to_le32(dir_ino); 3042 BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata"); 3043 if (!ent->dir_inlined) { 3044 if (is_dx(ent->inode)) { 3045 retval = ext4_handle_dirty_dx_node(handle, 3046 ent->inode, 3047 ent->dir_bh); 3048 } else { 3049 retval = ext4_handle_dirty_dirent_node(handle, 3050 ent->inode, 3051 ent->dir_bh); 3052 } 3053 } else { 3054 retval = ext4_mark_inode_dirty(handle, ent->inode); 3055 } 3056 if (retval) { 3057 ext4_std_error(ent->dir->i_sb, retval); 3058 return retval; 3059 } 3060 return 0; 3061 } 3062 3063 static int ext4_setent(handle_t *handle, struct ext4_renament *ent, 3064 unsigned ino, unsigned file_type) 3065 { 3066 int retval; 3067 3068 BUFFER_TRACE(ent->bh, "get write access"); 3069 retval = ext4_journal_get_write_access(handle, ent->bh); 3070 if (retval) 3071 return retval; 3072 ent->de->inode = cpu_to_le32(ino); 3073 if (EXT4_HAS_INCOMPAT_FEATURE(ent->dir->i_sb, 3074 EXT4_FEATURE_INCOMPAT_FILETYPE)) 3075 ent->de->file_type = file_type; 3076 ent->dir->i_version++; 3077 ent->dir->i_ctime = ent->dir->i_mtime = 3078 ext4_current_time(ent->dir); 3079 ext4_mark_inode_dirty(handle, ent->dir); 3080 BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata"); 3081 if (!ent->inlined) { 3082 retval = ext4_handle_dirty_dirent_node(handle, 3083 ent->dir, ent->bh); 3084 if (unlikely(retval)) { 3085 ext4_std_error(ent->dir->i_sb, retval); 3086 return retval; 3087 } 3088 } 3089 brelse(ent->bh); 3090 ent->bh = NULL; 3091 3092 return 0; 3093 } 3094 3095 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir, 3096 const struct qstr *d_name) 3097 { 3098 int retval = -ENOENT; 3099 struct buffer_head *bh; 3100 struct ext4_dir_entry_2 *de; 3101 3102 bh = ext4_find_entry(dir, d_name, &de, NULL); 3103 if (bh) { 3104 retval = ext4_delete_entry(handle, dir, de, bh); 3105 brelse(bh); 3106 } 3107 return retval; 3108 } 3109 3110 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent) 3111 { 3112 int retval; 3113 /* 3114 * ent->de could have moved from under us during htree split, so make 3115 * sure that we are deleting the right entry. We might also be pointing 3116 * to a stale entry in the unused part of ent->bh so just checking inum 3117 * and the name isn't enough. 3118 */ 3119 if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino || 3120 ent->de->name_len != ent->dentry->d_name.len || 3121 strncmp(ent->de->name, ent->dentry->d_name.name, 3122 ent->de->name_len)) { 3123 retval = ext4_find_delete_entry(handle, ent->dir, 3124 &ent->dentry->d_name); 3125 } else { 3126 retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh); 3127 if (retval == -ENOENT) { 3128 retval = ext4_find_delete_entry(handle, ent->dir, 3129 &ent->dentry->d_name); 3130 } 3131 } 3132 3133 if (retval) { 3134 ext4_warning(ent->dir->i_sb, 3135 "Deleting old file (%lu), %d, error=%d", 3136 ent->dir->i_ino, ent->dir->i_nlink, retval); 3137 } 3138 } 3139 3140 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent) 3141 { 3142 if (ent->dir_nlink_delta) { 3143 if (ent->dir_nlink_delta == -1) 3144 ext4_dec_count(handle, ent->dir); 3145 else 3146 ext4_inc_count(handle, ent->dir); 3147 ext4_mark_inode_dirty(handle, ent->dir); 3148 } 3149 } 3150 3151 /* 3152 * Anybody can rename anything with this: the permission checks are left to the 3153 * higher-level routines. 3154 * 3155 * n.b. old_{dentry,inode) refers to the source dentry/inode 3156 * while new_{dentry,inode) refers to the destination dentry/inode 3157 * This comes from rename(const char *oldpath, const char *newpath) 3158 */ 3159 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry, 3160 struct inode *new_dir, struct dentry *new_dentry) 3161 { 3162 handle_t *handle = NULL; 3163 struct ext4_renament old = { 3164 .dir = old_dir, 3165 .dentry = old_dentry, 3166 .inode = old_dentry->d_inode, 3167 }; 3168 struct ext4_renament new = { 3169 .dir = new_dir, 3170 .dentry = new_dentry, 3171 .inode = new_dentry->d_inode, 3172 }; 3173 int retval; 3174 3175 dquot_initialize(old.dir); 3176 dquot_initialize(new.dir); 3177 3178 /* Initialize quotas before so that eventual writes go 3179 * in separate transaction */ 3180 if (new.inode) 3181 dquot_initialize(new.inode); 3182 3183 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL); 3184 /* 3185 * Check for inode number is _not_ due to possible IO errors. 3186 * We might rmdir the source, keep it as pwd of some process 3187 * and merrily kill the link to whatever was created under the 3188 * same name. Goodbye sticky bit ;-< 3189 */ 3190 retval = -ENOENT; 3191 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino) 3192 goto end_rename; 3193 3194 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, 3195 &new.de, &new.inlined); 3196 if (new.bh) { 3197 if (!new.inode) { 3198 brelse(new.bh); 3199 new.bh = NULL; 3200 } 3201 } 3202 if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC)) 3203 ext4_alloc_da_blocks(old.inode); 3204 3205 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, 3206 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + 3207 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2)); 3208 if (IS_ERR(handle)) 3209 return PTR_ERR(handle); 3210 3211 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir)) 3212 ext4_handle_sync(handle); 3213 3214 if (S_ISDIR(old.inode->i_mode)) { 3215 if (new.inode) { 3216 retval = -ENOTEMPTY; 3217 if (!empty_dir(new.inode)) 3218 goto end_rename; 3219 } else { 3220 retval = -EMLINK; 3221 if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir)) 3222 goto end_rename; 3223 } 3224 retval = ext4_rename_dir_prepare(handle, &old); 3225 if (retval) 3226 goto end_rename; 3227 } 3228 if (!new.bh) { 3229 retval = ext4_add_entry(handle, new.dentry, old.inode); 3230 if (retval) 3231 goto end_rename; 3232 } else { 3233 retval = ext4_setent(handle, &new, 3234 old.inode->i_ino, old.de->file_type); 3235 if (retval) 3236 goto end_rename; 3237 } 3238 3239 /* 3240 * Like most other Unix systems, set the ctime for inodes on a 3241 * rename. 3242 */ 3243 old.inode->i_ctime = ext4_current_time(old.inode); 3244 ext4_mark_inode_dirty(handle, old.inode); 3245 3246 /* 3247 * ok, that's it 3248 */ 3249 ext4_rename_delete(handle, &old); 3250 3251 if (new.inode) { 3252 ext4_dec_count(handle, new.inode); 3253 new.inode->i_ctime = ext4_current_time(new.inode); 3254 } 3255 old.dir->i_ctime = old.dir->i_mtime = ext4_current_time(old.dir); 3256 ext4_update_dx_flag(old.dir); 3257 if (old.dir_bh) { 3258 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); 3259 if (retval) 3260 goto end_rename; 3261 3262 ext4_dec_count(handle, old.dir); 3263 if (new.inode) { 3264 /* checked empty_dir above, can't have another parent, 3265 * ext4_dec_count() won't work for many-linked dirs */ 3266 clear_nlink(new.inode); 3267 } else { 3268 ext4_inc_count(handle, new.dir); 3269 ext4_update_dx_flag(new.dir); 3270 ext4_mark_inode_dirty(handle, new.dir); 3271 } 3272 } 3273 ext4_mark_inode_dirty(handle, old.dir); 3274 if (new.inode) { 3275 ext4_mark_inode_dirty(handle, new.inode); 3276 if (!new.inode->i_nlink) 3277 ext4_orphan_add(handle, new.inode); 3278 } 3279 retval = 0; 3280 3281 end_rename: 3282 brelse(old.dir_bh); 3283 brelse(old.bh); 3284 brelse(new.bh); 3285 if (handle) 3286 ext4_journal_stop(handle); 3287 return retval; 3288 } 3289 3290 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry, 3291 struct inode *new_dir, struct dentry *new_dentry) 3292 { 3293 handle_t *handle = NULL; 3294 struct ext4_renament old = { 3295 .dir = old_dir, 3296 .dentry = old_dentry, 3297 .inode = old_dentry->d_inode, 3298 }; 3299 struct ext4_renament new = { 3300 .dir = new_dir, 3301 .dentry = new_dentry, 3302 .inode = new_dentry->d_inode, 3303 }; 3304 u8 new_file_type; 3305 int retval; 3306 3307 dquot_initialize(old.dir); 3308 dquot_initialize(new.dir); 3309 3310 old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, 3311 &old.de, &old.inlined); 3312 /* 3313 * Check for inode number is _not_ due to possible IO errors. 3314 * We might rmdir the source, keep it as pwd of some process 3315 * and merrily kill the link to whatever was created under the 3316 * same name. Goodbye sticky bit ;-< 3317 */ 3318 retval = -ENOENT; 3319 if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino) 3320 goto end_rename; 3321 3322 new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, 3323 &new.de, &new.inlined); 3324 3325 /* RENAME_EXCHANGE case: old *and* new must both exist */ 3326 if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino) 3327 goto end_rename; 3328 3329 handle = ext4_journal_start(old.dir, EXT4_HT_DIR, 3330 (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + 3331 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2)); 3332 if (IS_ERR(handle)) 3333 return PTR_ERR(handle); 3334 3335 if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir)) 3336 ext4_handle_sync(handle); 3337 3338 if (S_ISDIR(old.inode->i_mode)) { 3339 old.is_dir = true; 3340 retval = ext4_rename_dir_prepare(handle, &old); 3341 if (retval) 3342 goto end_rename; 3343 } 3344 if (S_ISDIR(new.inode->i_mode)) { 3345 new.is_dir = true; 3346 retval = ext4_rename_dir_prepare(handle, &new); 3347 if (retval) 3348 goto end_rename; 3349 } 3350 3351 /* 3352 * Other than the special case of overwriting a directory, parents' 3353 * nlink only needs to be modified if this is a cross directory rename. 3354 */ 3355 if (old.dir != new.dir && old.is_dir != new.is_dir) { 3356 old.dir_nlink_delta = old.is_dir ? -1 : 1; 3357 new.dir_nlink_delta = -old.dir_nlink_delta; 3358 retval = -EMLINK; 3359 if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) || 3360 (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir))) 3361 goto end_rename; 3362 } 3363 3364 new_file_type = new.de->file_type; 3365 retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type); 3366 if (retval) 3367 goto end_rename; 3368 3369 retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type); 3370 if (retval) 3371 goto end_rename; 3372 3373 /* 3374 * Like most other Unix systems, set the ctime for inodes on a 3375 * rename. 3376 */ 3377 old.inode->i_ctime = ext4_current_time(old.inode); 3378 new.inode->i_ctime = ext4_current_time(new.inode); 3379 ext4_mark_inode_dirty(handle, old.inode); 3380 ext4_mark_inode_dirty(handle, new.inode); 3381 3382 if (old.dir_bh) { 3383 retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); 3384 if (retval) 3385 goto end_rename; 3386 } 3387 if (new.dir_bh) { 3388 retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino); 3389 if (retval) 3390 goto end_rename; 3391 } 3392 ext4_update_dir_count(handle, &old); 3393 ext4_update_dir_count(handle, &new); 3394 retval = 0; 3395 3396 end_rename: 3397 brelse(old.dir_bh); 3398 brelse(new.dir_bh); 3399 brelse(old.bh); 3400 brelse(new.bh); 3401 if (handle) 3402 ext4_journal_stop(handle); 3403 return retval; 3404 } 3405 3406 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry, 3407 struct inode *new_dir, struct dentry *new_dentry, 3408 unsigned int flags) 3409 { 3410 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE)) 3411 return -EINVAL; 3412 3413 if (flags & RENAME_EXCHANGE) { 3414 return ext4_cross_rename(old_dir, old_dentry, 3415 new_dir, new_dentry); 3416 } 3417 /* 3418 * Existence checking was done by the VFS, otherwise "RENAME_NOREPLACE" 3419 * is equivalent to regular rename. 3420 */ 3421 return ext4_rename(old_dir, old_dentry, new_dir, new_dentry); 3422 } 3423 3424 /* 3425 * directories can handle most operations... 3426 */ 3427 const struct inode_operations ext4_dir_inode_operations = { 3428 .create = ext4_create, 3429 .lookup = ext4_lookup, 3430 .link = ext4_link, 3431 .unlink = ext4_unlink, 3432 .symlink = ext4_symlink, 3433 .mkdir = ext4_mkdir, 3434 .rmdir = ext4_rmdir, 3435 .mknod = ext4_mknod, 3436 .tmpfile = ext4_tmpfile, 3437 .rename = ext4_rename, 3438 .rename2 = ext4_rename2, 3439 .setattr = ext4_setattr, 3440 .setxattr = generic_setxattr, 3441 .getxattr = generic_getxattr, 3442 .listxattr = ext4_listxattr, 3443 .removexattr = generic_removexattr, 3444 .get_acl = ext4_get_acl, 3445 .set_acl = ext4_set_acl, 3446 .fiemap = ext4_fiemap, 3447 }; 3448 3449 const struct inode_operations ext4_special_inode_operations = { 3450 .setattr = ext4_setattr, 3451 .setxattr = generic_setxattr, 3452 .getxattr = generic_getxattr, 3453 .listxattr = ext4_listxattr, 3454 .removexattr = generic_removexattr, 3455 .get_acl = ext4_get_acl, 3456 .set_acl = ext4_set_acl, 3457 }; 3458