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 /* On error, skip the f_pos to the next block. */ 922 dir_file->f_pos = (dir_file->f_pos | 923 (dir->i_sb->s_blocksize - 1)) + 1; 924 brelse(bh); 925 return count; 926 } 927 ext4fs_dirhash(de->name, de->name_len, hinfo); 928 if ((hinfo->hash < start_hash) || 929 ((hinfo->hash == start_hash) && 930 (hinfo->minor_hash < start_minor_hash))) 931 continue; 932 if (de->inode == 0) 933 continue; 934 if ((err = ext4_htree_store_dirent(dir_file, 935 hinfo->hash, hinfo->minor_hash, de)) != 0) { 936 brelse(bh); 937 return err; 938 } 939 count++; 940 } 941 brelse(bh); 942 return count; 943 } 944 945 946 /* 947 * This function fills a red-black tree with information from a 948 * directory. We start scanning the directory in hash order, starting 949 * at start_hash and start_minor_hash. 950 * 951 * This function returns the number of entries inserted into the tree, 952 * or a negative error code. 953 */ 954 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash, 955 __u32 start_minor_hash, __u32 *next_hash) 956 { 957 struct dx_hash_info hinfo; 958 struct ext4_dir_entry_2 *de; 959 struct dx_frame frames[2], *frame; 960 struct inode *dir; 961 ext4_lblk_t block; 962 int count = 0; 963 int ret, err; 964 __u32 hashval; 965 966 dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n", 967 start_hash, start_minor_hash)); 968 dir = file_inode(dir_file); 969 if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) { 970 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version; 971 if (hinfo.hash_version <= DX_HASH_TEA) 972 hinfo.hash_version += 973 EXT4_SB(dir->i_sb)->s_hash_unsigned; 974 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; 975 if (ext4_has_inline_data(dir)) { 976 int has_inline_data = 1; 977 count = htree_inlinedir_to_tree(dir_file, dir, 0, 978 &hinfo, start_hash, 979 start_minor_hash, 980 &has_inline_data); 981 if (has_inline_data) { 982 *next_hash = ~0; 983 return count; 984 } 985 } 986 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo, 987 start_hash, start_minor_hash); 988 *next_hash = ~0; 989 return count; 990 } 991 hinfo.hash = start_hash; 992 hinfo.minor_hash = 0; 993 frame = dx_probe(NULL, dir, &hinfo, frames, &err); 994 if (!frame) 995 return err; 996 997 /* Add '.' and '..' from the htree header */ 998 if (!start_hash && !start_minor_hash) { 999 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; 1000 if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0) 1001 goto errout; 1002 count++; 1003 } 1004 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) { 1005 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; 1006 de = ext4_next_entry(de, dir->i_sb->s_blocksize); 1007 if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0) 1008 goto errout; 1009 count++; 1010 } 1011 1012 while (1) { 1013 block = dx_get_block(frame->at); 1014 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo, 1015 start_hash, start_minor_hash); 1016 if (ret < 0) { 1017 err = ret; 1018 goto errout; 1019 } 1020 count += ret; 1021 hashval = ~0; 1022 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS, 1023 frame, frames, &hashval); 1024 *next_hash = hashval; 1025 if (ret < 0) { 1026 err = ret; 1027 goto errout; 1028 } 1029 /* 1030 * Stop if: (a) there are no more entries, or 1031 * (b) we have inserted at least one entry and the 1032 * next hash value is not a continuation 1033 */ 1034 if ((ret == 0) || 1035 (count && ((hashval & 1) == 0))) 1036 break; 1037 } 1038 dx_release(frames); 1039 dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, " 1040 "next hash: %x\n", count, *next_hash)); 1041 return count; 1042 errout: 1043 dx_release(frames); 1044 return (err); 1045 } 1046 1047 static inline int search_dirblock(struct buffer_head *bh, 1048 struct inode *dir, 1049 const struct qstr *d_name, 1050 unsigned int offset, 1051 struct ext4_dir_entry_2 **res_dir) 1052 { 1053 return search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir, 1054 d_name, offset, res_dir); 1055 } 1056 1057 /* 1058 * Directory block splitting, compacting 1059 */ 1060 1061 /* 1062 * Create map of hash values, offsets, and sizes, stored at end of block. 1063 * Returns number of entries mapped. 1064 */ 1065 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize, 1066 struct dx_hash_info *hinfo, 1067 struct dx_map_entry *map_tail) 1068 { 1069 int count = 0; 1070 char *base = (char *) de; 1071 struct dx_hash_info h = *hinfo; 1072 1073 while ((char *) de < base + blocksize) { 1074 if (de->name_len && de->inode) { 1075 ext4fs_dirhash(de->name, de->name_len, &h); 1076 map_tail--; 1077 map_tail->hash = h.hash; 1078 map_tail->offs = ((char *) de - base)>>2; 1079 map_tail->size = le16_to_cpu(de->rec_len); 1080 count++; 1081 cond_resched(); 1082 } 1083 /* XXX: do we need to check rec_len == 0 case? -Chris */ 1084 de = ext4_next_entry(de, blocksize); 1085 } 1086 return count; 1087 } 1088 1089 /* Sort map by hash value */ 1090 static void dx_sort_map (struct dx_map_entry *map, unsigned count) 1091 { 1092 struct dx_map_entry *p, *q, *top = map + count - 1; 1093 int more; 1094 /* Combsort until bubble sort doesn't suck */ 1095 while (count > 2) { 1096 count = count*10/13; 1097 if (count - 9 < 2) /* 9, 10 -> 11 */ 1098 count = 11; 1099 for (p = top, q = p - count; q >= map; p--, q--) 1100 if (p->hash < q->hash) 1101 swap(*p, *q); 1102 } 1103 /* Garden variety bubble sort */ 1104 do { 1105 more = 0; 1106 q = top; 1107 while (q-- > map) { 1108 if (q[1].hash >= q[0].hash) 1109 continue; 1110 swap(*(q+1), *q); 1111 more = 1; 1112 } 1113 } while(more); 1114 } 1115 1116 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block) 1117 { 1118 struct dx_entry *entries = frame->entries; 1119 struct dx_entry *old = frame->at, *new = old + 1; 1120 int count = dx_get_count(entries); 1121 1122 assert(count < dx_get_limit(entries)); 1123 assert(old < entries + count); 1124 memmove(new + 1, new, (char *)(entries + count) - (char *)(new)); 1125 dx_set_hash(new, hash); 1126 dx_set_block(new, block); 1127 dx_set_count(entries, count + 1); 1128 } 1129 1130 /* 1131 * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure. 1132 * 1133 * `len <= EXT4_NAME_LEN' is guaranteed by caller. 1134 * `de != NULL' is guaranteed by caller. 1135 */ 1136 static inline int ext4_match (int len, const char * const name, 1137 struct ext4_dir_entry_2 * de) 1138 { 1139 if (len != de->name_len) 1140 return 0; 1141 if (!de->inode) 1142 return 0; 1143 return !memcmp(name, de->name, len); 1144 } 1145 1146 /* 1147 * Returns 0 if not found, -1 on failure, and 1 on success 1148 */ 1149 int search_dir(struct buffer_head *bh, 1150 char *search_buf, 1151 int buf_size, 1152 struct inode *dir, 1153 const struct qstr *d_name, 1154 unsigned int offset, 1155 struct ext4_dir_entry_2 **res_dir) 1156 { 1157 struct ext4_dir_entry_2 * de; 1158 char * dlimit; 1159 int de_len; 1160 const char *name = d_name->name; 1161 int namelen = d_name->len; 1162 1163 de = (struct ext4_dir_entry_2 *)search_buf; 1164 dlimit = search_buf + buf_size; 1165 while ((char *) de < dlimit) { 1166 /* this code is executed quadratically often */ 1167 /* do minimal checking `by hand' */ 1168 1169 if ((char *) de + namelen <= dlimit && 1170 ext4_match (namelen, name, de)) { 1171 /* found a match - just to be sure, do a full check */ 1172 if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data, 1173 bh->b_size, offset)) 1174 return -1; 1175 *res_dir = de; 1176 return 1; 1177 } 1178 /* prevent looping on a bad block */ 1179 de_len = ext4_rec_len_from_disk(de->rec_len, 1180 dir->i_sb->s_blocksize); 1181 if (de_len <= 0) 1182 return -1; 1183 offset += de_len; 1184 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len); 1185 } 1186 return 0; 1187 } 1188 1189 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block, 1190 struct ext4_dir_entry *de) 1191 { 1192 struct super_block *sb = dir->i_sb; 1193 1194 if (!is_dx(dir)) 1195 return 0; 1196 if (block == 0) 1197 return 1; 1198 if (de->inode == 0 && 1199 ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) == 1200 sb->s_blocksize) 1201 return 1; 1202 return 0; 1203 } 1204 1205 /* 1206 * ext4_find_entry() 1207 * 1208 * finds an entry in the specified directory with the wanted name. It 1209 * returns the cache buffer in which the entry was found, and the entry 1210 * itself (as a parameter - res_dir). It does NOT read the inode of the 1211 * entry - you'll have to do that yourself if you want to. 1212 * 1213 * The returned buffer_head has ->b_count elevated. The caller is expected 1214 * to brelse() it when appropriate. 1215 */ 1216 static struct buffer_head * ext4_find_entry (struct inode *dir, 1217 const struct qstr *d_name, 1218 struct ext4_dir_entry_2 **res_dir, 1219 int *inlined) 1220 { 1221 struct super_block *sb; 1222 struct buffer_head *bh_use[NAMEI_RA_SIZE]; 1223 struct buffer_head *bh, *ret = NULL; 1224 ext4_lblk_t start, block, b; 1225 const u8 *name = d_name->name; 1226 int ra_max = 0; /* Number of bh's in the readahead 1227 buffer, bh_use[] */ 1228 int ra_ptr = 0; /* Current index into readahead 1229 buffer */ 1230 int num = 0; 1231 ext4_lblk_t nblocks; 1232 int i, err; 1233 int namelen; 1234 1235 *res_dir = NULL; 1236 sb = dir->i_sb; 1237 namelen = d_name->len; 1238 if (namelen > EXT4_NAME_LEN) 1239 return NULL; 1240 1241 if (ext4_has_inline_data(dir)) { 1242 int has_inline_data = 1; 1243 ret = ext4_find_inline_entry(dir, d_name, res_dir, 1244 &has_inline_data); 1245 if (has_inline_data) { 1246 if (inlined) 1247 *inlined = 1; 1248 return ret; 1249 } 1250 } 1251 1252 if ((namelen <= 2) && (name[0] == '.') && 1253 (name[1] == '.' || name[1] == '\0')) { 1254 /* 1255 * "." or ".." will only be in the first block 1256 * NFS may look up ".."; "." should be handled by the VFS 1257 */ 1258 block = start = 0; 1259 nblocks = 1; 1260 goto restart; 1261 } 1262 if (is_dx(dir)) { 1263 bh = ext4_dx_find_entry(dir, d_name, res_dir, &err); 1264 /* 1265 * On success, or if the error was file not found, 1266 * return. Otherwise, fall back to doing a search the 1267 * old fashioned way. 1268 */ 1269 if (bh || (err != ERR_BAD_DX_DIR)) 1270 return bh; 1271 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, " 1272 "falling back\n")); 1273 } 1274 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); 1275 start = EXT4_I(dir)->i_dir_start_lookup; 1276 if (start >= nblocks) 1277 start = 0; 1278 block = start; 1279 restart: 1280 do { 1281 /* 1282 * We deal with the read-ahead logic here. 1283 */ 1284 if (ra_ptr >= ra_max) { 1285 /* Refill the readahead buffer */ 1286 ra_ptr = 0; 1287 b = block; 1288 for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) { 1289 /* 1290 * Terminate if we reach the end of the 1291 * directory and must wrap, or if our 1292 * search has finished at this block. 1293 */ 1294 if (b >= nblocks || (num && block == start)) { 1295 bh_use[ra_max] = NULL; 1296 break; 1297 } 1298 num++; 1299 bh = ext4_getblk(NULL, dir, b++, 0, &err); 1300 bh_use[ra_max] = bh; 1301 if (bh) 1302 ll_rw_block(READ | REQ_META | REQ_PRIO, 1303 1, &bh); 1304 } 1305 } 1306 if ((bh = bh_use[ra_ptr++]) == NULL) 1307 goto next; 1308 wait_on_buffer(bh); 1309 if (!buffer_uptodate(bh)) { 1310 /* read error, skip block & hope for the best */ 1311 EXT4_ERROR_INODE(dir, "reading directory lblock %lu", 1312 (unsigned long) block); 1313 brelse(bh); 1314 goto next; 1315 } 1316 if (!buffer_verified(bh) && 1317 !is_dx_internal_node(dir, block, 1318 (struct ext4_dir_entry *)bh->b_data) && 1319 !ext4_dirent_csum_verify(dir, 1320 (struct ext4_dir_entry *)bh->b_data)) { 1321 EXT4_ERROR_INODE(dir, "checksumming directory " 1322 "block %lu", (unsigned long)block); 1323 brelse(bh); 1324 goto next; 1325 } 1326 set_buffer_verified(bh); 1327 i = search_dirblock(bh, dir, d_name, 1328 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir); 1329 if (i == 1) { 1330 EXT4_I(dir)->i_dir_start_lookup = block; 1331 ret = bh; 1332 goto cleanup_and_exit; 1333 } else { 1334 brelse(bh); 1335 if (i < 0) 1336 goto cleanup_and_exit; 1337 } 1338 next: 1339 if (++block >= nblocks) 1340 block = 0; 1341 } while (block != start); 1342 1343 /* 1344 * If the directory has grown while we were searching, then 1345 * search the last part of the directory before giving up. 1346 */ 1347 block = nblocks; 1348 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); 1349 if (block < nblocks) { 1350 start = 0; 1351 goto restart; 1352 } 1353 1354 cleanup_and_exit: 1355 /* Clean up the read-ahead blocks */ 1356 for (; ra_ptr < ra_max; ra_ptr++) 1357 brelse(bh_use[ra_ptr]); 1358 return ret; 1359 } 1360 1361 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name, 1362 struct ext4_dir_entry_2 **res_dir, int *err) 1363 { 1364 struct super_block * sb = dir->i_sb; 1365 struct dx_hash_info hinfo; 1366 struct dx_frame frames[2], *frame; 1367 struct buffer_head *bh; 1368 ext4_lblk_t block; 1369 int retval; 1370 1371 if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err))) 1372 return NULL; 1373 do { 1374 block = dx_get_block(frame->at); 1375 bh = ext4_read_dirblock(dir, block, DIRENT); 1376 if (IS_ERR(bh)) { 1377 *err = PTR_ERR(bh); 1378 goto errout; 1379 } 1380 retval = search_dirblock(bh, dir, d_name, 1381 block << EXT4_BLOCK_SIZE_BITS(sb), 1382 res_dir); 1383 if (retval == 1) { /* Success! */ 1384 dx_release(frames); 1385 return bh; 1386 } 1387 brelse(bh); 1388 if (retval == -1) { 1389 *err = ERR_BAD_DX_DIR; 1390 goto errout; 1391 } 1392 1393 /* Check to see if we should continue to search */ 1394 retval = ext4_htree_next_block(dir, hinfo.hash, frame, 1395 frames, NULL); 1396 if (retval < 0) { 1397 ext4_warning(sb, 1398 "error reading index page in directory #%lu", 1399 dir->i_ino); 1400 *err = retval; 1401 goto errout; 1402 } 1403 } while (retval == 1); 1404 1405 *err = -ENOENT; 1406 errout: 1407 dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name)); 1408 dx_release (frames); 1409 return NULL; 1410 } 1411 1412 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) 1413 { 1414 struct inode *inode; 1415 struct ext4_dir_entry_2 *de; 1416 struct buffer_head *bh; 1417 1418 if (dentry->d_name.len > EXT4_NAME_LEN) 1419 return ERR_PTR(-ENAMETOOLONG); 1420 1421 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); 1422 inode = NULL; 1423 if (bh) { 1424 __u32 ino = le32_to_cpu(de->inode); 1425 brelse(bh); 1426 if (!ext4_valid_inum(dir->i_sb, ino)) { 1427 EXT4_ERROR_INODE(dir, "bad inode number: %u", ino); 1428 return ERR_PTR(-EIO); 1429 } 1430 if (unlikely(ino == dir->i_ino)) { 1431 EXT4_ERROR_INODE(dir, "'%.*s' linked to parent dir", 1432 dentry->d_name.len, 1433 dentry->d_name.name); 1434 return ERR_PTR(-EIO); 1435 } 1436 inode = ext4_iget(dir->i_sb, ino); 1437 if (inode == ERR_PTR(-ESTALE)) { 1438 EXT4_ERROR_INODE(dir, 1439 "deleted inode referenced: %u", 1440 ino); 1441 return ERR_PTR(-EIO); 1442 } 1443 } 1444 return d_splice_alias(inode, dentry); 1445 } 1446 1447 1448 struct dentry *ext4_get_parent(struct dentry *child) 1449 { 1450 __u32 ino; 1451 static const struct qstr dotdot = QSTR_INIT("..", 2); 1452 struct ext4_dir_entry_2 * de; 1453 struct buffer_head *bh; 1454 1455 bh = ext4_find_entry(child->d_inode, &dotdot, &de, NULL); 1456 if (!bh) 1457 return ERR_PTR(-ENOENT); 1458 ino = le32_to_cpu(de->inode); 1459 brelse(bh); 1460 1461 if (!ext4_valid_inum(child->d_inode->i_sb, ino)) { 1462 EXT4_ERROR_INODE(child->d_inode, 1463 "bad parent inode number: %u", ino); 1464 return ERR_PTR(-EIO); 1465 } 1466 1467 return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino)); 1468 } 1469 1470 /* 1471 * Move count entries from end of map between two memory locations. 1472 * Returns pointer to last entry moved. 1473 */ 1474 static struct ext4_dir_entry_2 * 1475 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count, 1476 unsigned blocksize) 1477 { 1478 unsigned rec_len = 0; 1479 1480 while (count--) { 1481 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) 1482 (from + (map->offs<<2)); 1483 rec_len = EXT4_DIR_REC_LEN(de->name_len); 1484 memcpy (to, de, rec_len); 1485 ((struct ext4_dir_entry_2 *) to)->rec_len = 1486 ext4_rec_len_to_disk(rec_len, blocksize); 1487 de->inode = 0; 1488 map++; 1489 to += rec_len; 1490 } 1491 return (struct ext4_dir_entry_2 *) (to - rec_len); 1492 } 1493 1494 /* 1495 * Compact each dir entry in the range to the minimal rec_len. 1496 * Returns pointer to last entry in range. 1497 */ 1498 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize) 1499 { 1500 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base; 1501 unsigned rec_len = 0; 1502 1503 prev = to = de; 1504 while ((char*)de < base + blocksize) { 1505 next = ext4_next_entry(de, blocksize); 1506 if (de->inode && de->name_len) { 1507 rec_len = EXT4_DIR_REC_LEN(de->name_len); 1508 if (de > to) 1509 memmove(to, de, rec_len); 1510 to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize); 1511 prev = to; 1512 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len); 1513 } 1514 de = next; 1515 } 1516 return prev; 1517 } 1518 1519 /* 1520 * Split a full leaf block to make room for a new dir entry. 1521 * Allocate a new block, and move entries so that they are approx. equally full. 1522 * Returns pointer to de in block into which the new entry will be inserted. 1523 */ 1524 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir, 1525 struct buffer_head **bh,struct dx_frame *frame, 1526 struct dx_hash_info *hinfo, int *error) 1527 { 1528 unsigned blocksize = dir->i_sb->s_blocksize; 1529 unsigned count, continued; 1530 struct buffer_head *bh2; 1531 ext4_lblk_t newblock; 1532 u32 hash2; 1533 struct dx_map_entry *map; 1534 char *data1 = (*bh)->b_data, *data2; 1535 unsigned split, move, size; 1536 struct ext4_dir_entry_2 *de = NULL, *de2; 1537 struct ext4_dir_entry_tail *t; 1538 int csum_size = 0; 1539 int err = 0, i; 1540 1541 if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb, 1542 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) 1543 csum_size = sizeof(struct ext4_dir_entry_tail); 1544 1545 bh2 = ext4_append(handle, dir, &newblock); 1546 if (IS_ERR(bh2)) { 1547 brelse(*bh); 1548 *bh = NULL; 1549 *error = PTR_ERR(bh2); 1550 return NULL; 1551 } 1552 1553 BUFFER_TRACE(*bh, "get_write_access"); 1554 err = ext4_journal_get_write_access(handle, *bh); 1555 if (err) 1556 goto journal_error; 1557 1558 BUFFER_TRACE(frame->bh, "get_write_access"); 1559 err = ext4_journal_get_write_access(handle, frame->bh); 1560 if (err) 1561 goto journal_error; 1562 1563 data2 = bh2->b_data; 1564 1565 /* create map in the end of data2 block */ 1566 map = (struct dx_map_entry *) (data2 + blocksize); 1567 count = dx_make_map((struct ext4_dir_entry_2 *) data1, 1568 blocksize, hinfo, map); 1569 map -= count; 1570 dx_sort_map(map, count); 1571 /* Split the existing block in the middle, size-wise */ 1572 size = 0; 1573 move = 0; 1574 for (i = count-1; i >= 0; i--) { 1575 /* is more than half of this entry in 2nd half of the block? */ 1576 if (size + map[i].size/2 > blocksize/2) 1577 break; 1578 size += map[i].size; 1579 move++; 1580 } 1581 /* map index at which we will split */ 1582 split = count - move; 1583 hash2 = map[split].hash; 1584 continued = hash2 == map[split - 1].hash; 1585 dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n", 1586 (unsigned long)dx_get_block(frame->at), 1587 hash2, split, count-split)); 1588 1589 /* Fancy dance to stay within two buffers */ 1590 de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize); 1591 de = dx_pack_dirents(data1, blocksize); 1592 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) - 1593 (char *) de, 1594 blocksize); 1595 de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) - 1596 (char *) de2, 1597 blocksize); 1598 if (csum_size) { 1599 t = EXT4_DIRENT_TAIL(data2, blocksize); 1600 initialize_dirent_tail(t, blocksize); 1601 1602 t = EXT4_DIRENT_TAIL(data1, blocksize); 1603 initialize_dirent_tail(t, blocksize); 1604 } 1605 1606 dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1)); 1607 dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1)); 1608 1609 /* Which block gets the new entry? */ 1610 if (hinfo->hash >= hash2) 1611 { 1612 swap(*bh, bh2); 1613 de = de2; 1614 } 1615 dx_insert_block(frame, hash2 + continued, newblock); 1616 err = ext4_handle_dirty_dirent_node(handle, dir, bh2); 1617 if (err) 1618 goto journal_error; 1619 err = ext4_handle_dirty_dx_node(handle, dir, frame->bh); 1620 if (err) 1621 goto journal_error; 1622 brelse(bh2); 1623 dxtrace(dx_show_index("frame", frame->entries)); 1624 return de; 1625 1626 journal_error: 1627 brelse(*bh); 1628 brelse(bh2); 1629 *bh = NULL; 1630 ext4_std_error(dir->i_sb, err); 1631 *error = err; 1632 return NULL; 1633 } 1634 1635 int ext4_find_dest_de(struct inode *dir, struct inode *inode, 1636 struct buffer_head *bh, 1637 void *buf, int buf_size, 1638 const char *name, int namelen, 1639 struct ext4_dir_entry_2 **dest_de) 1640 { 1641 struct ext4_dir_entry_2 *de; 1642 unsigned short reclen = EXT4_DIR_REC_LEN(namelen); 1643 int nlen, rlen; 1644 unsigned int offset = 0; 1645 char *top; 1646 1647 de = (struct ext4_dir_entry_2 *)buf; 1648 top = buf + buf_size - reclen; 1649 while ((char *) de <= top) { 1650 if (ext4_check_dir_entry(dir, NULL, de, bh, 1651 buf, buf_size, offset)) 1652 return -EIO; 1653 if (ext4_match(namelen, name, de)) 1654 return -EEXIST; 1655 nlen = EXT4_DIR_REC_LEN(de->name_len); 1656 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 1657 if ((de->inode ? rlen - nlen : rlen) >= reclen) 1658 break; 1659 de = (struct ext4_dir_entry_2 *)((char *)de + rlen); 1660 offset += rlen; 1661 } 1662 if ((char *) de > top) 1663 return -ENOSPC; 1664 1665 *dest_de = de; 1666 return 0; 1667 } 1668 1669 void ext4_insert_dentry(struct inode *inode, 1670 struct ext4_dir_entry_2 *de, 1671 int buf_size, 1672 const char *name, int namelen) 1673 { 1674 1675 int nlen, rlen; 1676 1677 nlen = EXT4_DIR_REC_LEN(de->name_len); 1678 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 1679 if (de->inode) { 1680 struct ext4_dir_entry_2 *de1 = 1681 (struct ext4_dir_entry_2 *)((char *)de + nlen); 1682 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size); 1683 de->rec_len = ext4_rec_len_to_disk(nlen, buf_size); 1684 de = de1; 1685 } 1686 de->file_type = EXT4_FT_UNKNOWN; 1687 de->inode = cpu_to_le32(inode->i_ino); 1688 ext4_set_de_type(inode->i_sb, de, inode->i_mode); 1689 de->name_len = namelen; 1690 memcpy(de->name, name, namelen); 1691 } 1692 /* 1693 * Add a new entry into a directory (leaf) block. If de is non-NULL, 1694 * it points to a directory entry which is guaranteed to be large 1695 * enough for new directory entry. If de is NULL, then 1696 * add_dirent_to_buf will attempt search the directory block for 1697 * space. It will return -ENOSPC if no space is available, and -EIO 1698 * and -EEXIST if directory entry already exists. 1699 */ 1700 static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry, 1701 struct inode *inode, struct ext4_dir_entry_2 *de, 1702 struct buffer_head *bh) 1703 { 1704 struct inode *dir = dentry->d_parent->d_inode; 1705 const char *name = dentry->d_name.name; 1706 int namelen = dentry->d_name.len; 1707 unsigned int blocksize = dir->i_sb->s_blocksize; 1708 int csum_size = 0; 1709 int err; 1710 1711 if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb, 1712 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) 1713 csum_size = sizeof(struct ext4_dir_entry_tail); 1714 1715 if (!de) { 1716 err = ext4_find_dest_de(dir, inode, 1717 bh, bh->b_data, blocksize - csum_size, 1718 name, namelen, &de); 1719 if (err) 1720 return err; 1721 } 1722 BUFFER_TRACE(bh, "get_write_access"); 1723 err = ext4_journal_get_write_access(handle, bh); 1724 if (err) { 1725 ext4_std_error(dir->i_sb, err); 1726 return err; 1727 } 1728 1729 /* By now the buffer is marked for journaling */ 1730 ext4_insert_dentry(inode, de, blocksize, name, namelen); 1731 1732 /* 1733 * XXX shouldn't update any times until successful 1734 * completion of syscall, but too many callers depend 1735 * on this. 1736 * 1737 * XXX similarly, too many callers depend on 1738 * ext4_new_inode() setting the times, but error 1739 * recovery deletes the inode, so the worst that can 1740 * happen is that the times are slightly out of date 1741 * and/or different from the directory change time. 1742 */ 1743 dir->i_mtime = dir->i_ctime = ext4_current_time(dir); 1744 ext4_update_dx_flag(dir); 1745 dir->i_version++; 1746 ext4_mark_inode_dirty(handle, dir); 1747 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); 1748 err = ext4_handle_dirty_dirent_node(handle, dir, bh); 1749 if (err) 1750 ext4_std_error(dir->i_sb, err); 1751 return 0; 1752 } 1753 1754 /* 1755 * This converts a one block unindexed directory to a 3 block indexed 1756 * directory, and adds the dentry to the indexed directory. 1757 */ 1758 static int make_indexed_dir(handle_t *handle, struct dentry *dentry, 1759 struct inode *inode, struct buffer_head *bh) 1760 { 1761 struct inode *dir = dentry->d_parent->d_inode; 1762 const char *name = dentry->d_name.name; 1763 int namelen = dentry->d_name.len; 1764 struct buffer_head *bh2; 1765 struct dx_root *root; 1766 struct dx_frame frames[2], *frame; 1767 struct dx_entry *entries; 1768 struct ext4_dir_entry_2 *de, *de2; 1769 struct ext4_dir_entry_tail *t; 1770 char *data1, *top; 1771 unsigned len; 1772 int retval; 1773 unsigned blocksize; 1774 struct dx_hash_info hinfo; 1775 ext4_lblk_t block; 1776 struct fake_dirent *fde; 1777 int csum_size = 0; 1778 1779 if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb, 1780 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) 1781 csum_size = sizeof(struct ext4_dir_entry_tail); 1782 1783 blocksize = dir->i_sb->s_blocksize; 1784 dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino)); 1785 retval = ext4_journal_get_write_access(handle, bh); 1786 if (retval) { 1787 ext4_std_error(dir->i_sb, retval); 1788 brelse(bh); 1789 return retval; 1790 } 1791 root = (struct dx_root *) bh->b_data; 1792 1793 /* The 0th block becomes the root, move the dirents out */ 1794 fde = &root->dotdot; 1795 de = (struct ext4_dir_entry_2 *)((char *)fde + 1796 ext4_rec_len_from_disk(fde->rec_len, blocksize)); 1797 if ((char *) de >= (((char *) root) + blocksize)) { 1798 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'"); 1799 brelse(bh); 1800 return -EIO; 1801 } 1802 len = ((char *) root) + (blocksize - csum_size) - (char *) de; 1803 1804 /* Allocate new block for the 0th block's dirents */ 1805 bh2 = ext4_append(handle, dir, &block); 1806 if (IS_ERR(bh2)) { 1807 brelse(bh); 1808 return PTR_ERR(bh2); 1809 } 1810 ext4_set_inode_flag(dir, EXT4_INODE_INDEX); 1811 data1 = bh2->b_data; 1812 1813 memcpy (data1, de, len); 1814 de = (struct ext4_dir_entry_2 *) data1; 1815 top = data1 + len; 1816 while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top) 1817 de = de2; 1818 de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) - 1819 (char *) de, 1820 blocksize); 1821 1822 if (csum_size) { 1823 t = EXT4_DIRENT_TAIL(data1, blocksize); 1824 initialize_dirent_tail(t, blocksize); 1825 } 1826 1827 /* Initialize the root; the dot dirents already exist */ 1828 de = (struct ext4_dir_entry_2 *) (&root->dotdot); 1829 de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2), 1830 blocksize); 1831 memset (&root->info, 0, sizeof(root->info)); 1832 root->info.info_length = sizeof(root->info); 1833 root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version; 1834 entries = root->entries; 1835 dx_set_block(entries, 1); 1836 dx_set_count(entries, 1); 1837 dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info))); 1838 1839 /* Initialize as for dx_probe */ 1840 hinfo.hash_version = root->info.hash_version; 1841 if (hinfo.hash_version <= DX_HASH_TEA) 1842 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; 1843 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; 1844 ext4fs_dirhash(name, namelen, &hinfo); 1845 frame = frames; 1846 frame->entries = entries; 1847 frame->at = entries; 1848 frame->bh = bh; 1849 bh = bh2; 1850 1851 ext4_handle_dirty_dx_node(handle, dir, frame->bh); 1852 ext4_handle_dirty_dirent_node(handle, dir, bh); 1853 1854 de = do_split(handle,dir, &bh, frame, &hinfo, &retval); 1855 if (!de) { 1856 /* 1857 * Even if the block split failed, we have to properly write 1858 * out all the changes we did so far. Otherwise we can end up 1859 * with corrupted filesystem. 1860 */ 1861 ext4_mark_inode_dirty(handle, dir); 1862 dx_release(frames); 1863 return retval; 1864 } 1865 dx_release(frames); 1866 1867 retval = add_dirent_to_buf(handle, dentry, inode, de, bh); 1868 brelse(bh); 1869 return retval; 1870 } 1871 1872 /* 1873 * ext4_add_entry() 1874 * 1875 * adds a file entry to the specified directory, using the same 1876 * semantics as ext4_find_entry(). It returns NULL if it failed. 1877 * 1878 * NOTE!! The inode part of 'de' is left at 0 - which means you 1879 * may not sleep between calling this and putting something into 1880 * the entry, as someone else might have used it while you slept. 1881 */ 1882 static int ext4_add_entry(handle_t *handle, struct dentry *dentry, 1883 struct inode *inode) 1884 { 1885 struct inode *dir = dentry->d_parent->d_inode; 1886 struct buffer_head *bh; 1887 struct ext4_dir_entry_2 *de; 1888 struct ext4_dir_entry_tail *t; 1889 struct super_block *sb; 1890 int retval; 1891 int dx_fallback=0; 1892 unsigned blocksize; 1893 ext4_lblk_t block, blocks; 1894 int csum_size = 0; 1895 1896 if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb, 1897 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) 1898 csum_size = sizeof(struct ext4_dir_entry_tail); 1899 1900 sb = dir->i_sb; 1901 blocksize = sb->s_blocksize; 1902 if (!dentry->d_name.len) 1903 return -EINVAL; 1904 1905 if (ext4_has_inline_data(dir)) { 1906 retval = ext4_try_add_inline_entry(handle, dentry, inode); 1907 if (retval < 0) 1908 return retval; 1909 if (retval == 1) { 1910 retval = 0; 1911 return retval; 1912 } 1913 } 1914 1915 if (is_dx(dir)) { 1916 retval = ext4_dx_add_entry(handle, dentry, inode); 1917 if (!retval || (retval != ERR_BAD_DX_DIR)) 1918 return retval; 1919 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX); 1920 dx_fallback++; 1921 ext4_mark_inode_dirty(handle, dir); 1922 } 1923 blocks = dir->i_size >> sb->s_blocksize_bits; 1924 for (block = 0; block < blocks; block++) { 1925 bh = ext4_read_dirblock(dir, block, DIRENT); 1926 if (IS_ERR(bh)) 1927 return PTR_ERR(bh); 1928 1929 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh); 1930 if (retval != -ENOSPC) { 1931 brelse(bh); 1932 return retval; 1933 } 1934 1935 if (blocks == 1 && !dx_fallback && 1936 EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) 1937 return make_indexed_dir(handle, dentry, inode, bh); 1938 brelse(bh); 1939 } 1940 bh = ext4_append(handle, dir, &block); 1941 if (IS_ERR(bh)) 1942 return PTR_ERR(bh); 1943 de = (struct ext4_dir_entry_2 *) bh->b_data; 1944 de->inode = 0; 1945 de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize); 1946 1947 if (csum_size) { 1948 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize); 1949 initialize_dirent_tail(t, blocksize); 1950 } 1951 1952 retval = add_dirent_to_buf(handle, dentry, inode, de, bh); 1953 brelse(bh); 1954 if (retval == 0) 1955 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY); 1956 return retval; 1957 } 1958 1959 /* 1960 * Returns 0 for success, or a negative error value 1961 */ 1962 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry, 1963 struct inode *inode) 1964 { 1965 struct dx_frame frames[2], *frame; 1966 struct dx_entry *entries, *at; 1967 struct dx_hash_info hinfo; 1968 struct buffer_head *bh; 1969 struct inode *dir = dentry->d_parent->d_inode; 1970 struct super_block *sb = dir->i_sb; 1971 struct ext4_dir_entry_2 *de; 1972 int err; 1973 1974 frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, &err); 1975 if (!frame) 1976 return err; 1977 entries = frame->entries; 1978 at = frame->at; 1979 bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT); 1980 if (IS_ERR(bh)) { 1981 err = PTR_ERR(bh); 1982 bh = NULL; 1983 goto cleanup; 1984 } 1985 1986 BUFFER_TRACE(bh, "get_write_access"); 1987 err = ext4_journal_get_write_access(handle, bh); 1988 if (err) 1989 goto journal_error; 1990 1991 err = add_dirent_to_buf(handle, dentry, inode, NULL, bh); 1992 if (err != -ENOSPC) 1993 goto cleanup; 1994 1995 /* Block full, should compress but for now just split */ 1996 dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n", 1997 dx_get_count(entries), dx_get_limit(entries))); 1998 /* Need to split index? */ 1999 if (dx_get_count(entries) == dx_get_limit(entries)) { 2000 ext4_lblk_t newblock; 2001 unsigned icount = dx_get_count(entries); 2002 int levels = frame - frames; 2003 struct dx_entry *entries2; 2004 struct dx_node *node2; 2005 struct buffer_head *bh2; 2006 2007 if (levels && (dx_get_count(frames->entries) == 2008 dx_get_limit(frames->entries))) { 2009 ext4_warning(sb, "Directory index full!"); 2010 err = -ENOSPC; 2011 goto cleanup; 2012 } 2013 bh2 = ext4_append(handle, dir, &newblock); 2014 if (IS_ERR(bh2)) { 2015 err = PTR_ERR(bh2); 2016 goto cleanup; 2017 } 2018 node2 = (struct dx_node *)(bh2->b_data); 2019 entries2 = node2->entries; 2020 memset(&node2->fake, 0, sizeof(struct fake_dirent)); 2021 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize, 2022 sb->s_blocksize); 2023 BUFFER_TRACE(frame->bh, "get_write_access"); 2024 err = ext4_journal_get_write_access(handle, frame->bh); 2025 if (err) 2026 goto journal_error; 2027 if (levels) { 2028 unsigned icount1 = icount/2, icount2 = icount - icount1; 2029 unsigned hash2 = dx_get_hash(entries + icount1); 2030 dxtrace(printk(KERN_DEBUG "Split index %i/%i\n", 2031 icount1, icount2)); 2032 2033 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */ 2034 err = ext4_journal_get_write_access(handle, 2035 frames[0].bh); 2036 if (err) 2037 goto journal_error; 2038 2039 memcpy((char *) entries2, (char *) (entries + icount1), 2040 icount2 * sizeof(struct dx_entry)); 2041 dx_set_count(entries, icount1); 2042 dx_set_count(entries2, icount2); 2043 dx_set_limit(entries2, dx_node_limit(dir)); 2044 2045 /* Which index block gets the new entry? */ 2046 if (at - entries >= icount1) { 2047 frame->at = at = at - entries - icount1 + entries2; 2048 frame->entries = entries = entries2; 2049 swap(frame->bh, bh2); 2050 } 2051 dx_insert_block(frames + 0, hash2, newblock); 2052 dxtrace(dx_show_index("node", frames[1].entries)); 2053 dxtrace(dx_show_index("node", 2054 ((struct dx_node *) bh2->b_data)->entries)); 2055 err = ext4_handle_dirty_dx_node(handle, dir, bh2); 2056 if (err) 2057 goto journal_error; 2058 brelse (bh2); 2059 } else { 2060 dxtrace(printk(KERN_DEBUG 2061 "Creating second level index...\n")); 2062 memcpy((char *) entries2, (char *) entries, 2063 icount * sizeof(struct dx_entry)); 2064 dx_set_limit(entries2, dx_node_limit(dir)); 2065 2066 /* Set up root */ 2067 dx_set_count(entries, 1); 2068 dx_set_block(entries + 0, newblock); 2069 ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1; 2070 2071 /* Add new access path frame */ 2072 frame = frames + 1; 2073 frame->at = at = at - entries + entries2; 2074 frame->entries = entries = entries2; 2075 frame->bh = bh2; 2076 err = ext4_journal_get_write_access(handle, 2077 frame->bh); 2078 if (err) 2079 goto journal_error; 2080 } 2081 err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh); 2082 if (err) { 2083 ext4_std_error(inode->i_sb, err); 2084 goto cleanup; 2085 } 2086 } 2087 de = do_split(handle, dir, &bh, frame, &hinfo, &err); 2088 if (!de) 2089 goto cleanup; 2090 err = add_dirent_to_buf(handle, dentry, inode, de, bh); 2091 goto cleanup; 2092 2093 journal_error: 2094 ext4_std_error(dir->i_sb, err); 2095 cleanup: 2096 brelse(bh); 2097 dx_release(frames); 2098 return err; 2099 } 2100 2101 /* 2102 * ext4_generic_delete_entry deletes a directory entry by merging it 2103 * with the previous entry 2104 */ 2105 int ext4_generic_delete_entry(handle_t *handle, 2106 struct inode *dir, 2107 struct ext4_dir_entry_2 *de_del, 2108 struct buffer_head *bh, 2109 void *entry_buf, 2110 int buf_size, 2111 int csum_size) 2112 { 2113 struct ext4_dir_entry_2 *de, *pde; 2114 unsigned int blocksize = dir->i_sb->s_blocksize; 2115 int i; 2116 2117 i = 0; 2118 pde = NULL; 2119 de = (struct ext4_dir_entry_2 *)entry_buf; 2120 while (i < buf_size - csum_size) { 2121 if (ext4_check_dir_entry(dir, NULL, de, bh, 2122 bh->b_data, bh->b_size, i)) 2123 return -EIO; 2124 if (de == de_del) { 2125 if (pde) 2126 pde->rec_len = ext4_rec_len_to_disk( 2127 ext4_rec_len_from_disk(pde->rec_len, 2128 blocksize) + 2129 ext4_rec_len_from_disk(de->rec_len, 2130 blocksize), 2131 blocksize); 2132 else 2133 de->inode = 0; 2134 dir->i_version++; 2135 return 0; 2136 } 2137 i += ext4_rec_len_from_disk(de->rec_len, blocksize); 2138 pde = de; 2139 de = ext4_next_entry(de, blocksize); 2140 } 2141 return -ENOENT; 2142 } 2143 2144 static int ext4_delete_entry(handle_t *handle, 2145 struct inode *dir, 2146 struct ext4_dir_entry_2 *de_del, 2147 struct buffer_head *bh) 2148 { 2149 int err, csum_size = 0; 2150 2151 if (ext4_has_inline_data(dir)) { 2152 int has_inline_data = 1; 2153 err = ext4_delete_inline_entry(handle, dir, de_del, bh, 2154 &has_inline_data); 2155 if (has_inline_data) 2156 return err; 2157 } 2158 2159 if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb, 2160 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) 2161 csum_size = sizeof(struct ext4_dir_entry_tail); 2162 2163 BUFFER_TRACE(bh, "get_write_access"); 2164 err = ext4_journal_get_write_access(handle, bh); 2165 if (unlikely(err)) 2166 goto out; 2167 2168 err = ext4_generic_delete_entry(handle, dir, de_del, 2169 bh, bh->b_data, 2170 dir->i_sb->s_blocksize, csum_size); 2171 if (err) 2172 goto out; 2173 2174 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); 2175 err = ext4_handle_dirty_dirent_node(handle, dir, bh); 2176 if (unlikely(err)) 2177 goto out; 2178 2179 return 0; 2180 out: 2181 if (err != -ENOENT) 2182 ext4_std_error(dir->i_sb, err); 2183 return err; 2184 } 2185 2186 /* 2187 * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2, 2188 * since this indicates that nlinks count was previously 1. 2189 */ 2190 static void ext4_inc_count(handle_t *handle, struct inode *inode) 2191 { 2192 inc_nlink(inode); 2193 if (is_dx(inode) && inode->i_nlink > 1) { 2194 /* limit is 16-bit i_links_count */ 2195 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) { 2196 set_nlink(inode, 1); 2197 EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb, 2198 EXT4_FEATURE_RO_COMPAT_DIR_NLINK); 2199 } 2200 } 2201 } 2202 2203 /* 2204 * If a directory had nlink == 1, then we should let it be 1. This indicates 2205 * directory has >EXT4_LINK_MAX subdirs. 2206 */ 2207 static void ext4_dec_count(handle_t *handle, struct inode *inode) 2208 { 2209 if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2) 2210 drop_nlink(inode); 2211 } 2212 2213 2214 static int ext4_add_nondir(handle_t *handle, 2215 struct dentry *dentry, struct inode *inode) 2216 { 2217 int err = ext4_add_entry(handle, dentry, inode); 2218 if (!err) { 2219 ext4_mark_inode_dirty(handle, inode); 2220 unlock_new_inode(inode); 2221 d_instantiate(dentry, inode); 2222 return 0; 2223 } 2224 drop_nlink(inode); 2225 unlock_new_inode(inode); 2226 iput(inode); 2227 return err; 2228 } 2229 2230 /* 2231 * By the time this is called, we already have created 2232 * the directory cache entry for the new file, but it 2233 * is so far negative - it has no inode. 2234 * 2235 * If the create succeeds, we fill in the inode information 2236 * with d_instantiate(). 2237 */ 2238 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode, 2239 bool excl) 2240 { 2241 handle_t *handle; 2242 struct inode *inode; 2243 int err, credits, retries = 0; 2244 2245 dquot_initialize(dir); 2246 2247 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2248 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2249 retry: 2250 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0, 2251 NULL, EXT4_HT_DIR, credits); 2252 handle = ext4_journal_current_handle(); 2253 err = PTR_ERR(inode); 2254 if (!IS_ERR(inode)) { 2255 inode->i_op = &ext4_file_inode_operations; 2256 inode->i_fop = &ext4_file_operations; 2257 ext4_set_aops(inode); 2258 err = ext4_add_nondir(handle, dentry, inode); 2259 if (!err && IS_DIRSYNC(dir)) 2260 ext4_handle_sync(handle); 2261 } 2262 if (handle) 2263 ext4_journal_stop(handle); 2264 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2265 goto retry; 2266 return err; 2267 } 2268 2269 static int ext4_mknod(struct inode *dir, struct dentry *dentry, 2270 umode_t mode, dev_t rdev) 2271 { 2272 handle_t *handle; 2273 struct inode *inode; 2274 int err, credits, retries = 0; 2275 2276 if (!new_valid_dev(rdev)) 2277 return -EINVAL; 2278 2279 dquot_initialize(dir); 2280 2281 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2282 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2283 retry: 2284 inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0, 2285 NULL, EXT4_HT_DIR, credits); 2286 handle = ext4_journal_current_handle(); 2287 err = PTR_ERR(inode); 2288 if (!IS_ERR(inode)) { 2289 init_special_inode(inode, inode->i_mode, rdev); 2290 inode->i_op = &ext4_special_inode_operations; 2291 err = ext4_add_nondir(handle, dentry, inode); 2292 if (!err && IS_DIRSYNC(dir)) 2293 ext4_handle_sync(handle); 2294 } 2295 if (handle) 2296 ext4_journal_stop(handle); 2297 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2298 goto retry; 2299 return err; 2300 } 2301 2302 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode, 2303 struct ext4_dir_entry_2 *de, 2304 int blocksize, int csum_size, 2305 unsigned int parent_ino, int dotdot_real_len) 2306 { 2307 de->inode = cpu_to_le32(inode->i_ino); 2308 de->name_len = 1; 2309 de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len), 2310 blocksize); 2311 strcpy(de->name, "."); 2312 ext4_set_de_type(inode->i_sb, de, S_IFDIR); 2313 2314 de = ext4_next_entry(de, blocksize); 2315 de->inode = cpu_to_le32(parent_ino); 2316 de->name_len = 2; 2317 if (!dotdot_real_len) 2318 de->rec_len = ext4_rec_len_to_disk(blocksize - 2319 (csum_size + EXT4_DIR_REC_LEN(1)), 2320 blocksize); 2321 else 2322 de->rec_len = ext4_rec_len_to_disk( 2323 EXT4_DIR_REC_LEN(de->name_len), blocksize); 2324 strcpy(de->name, ".."); 2325 ext4_set_de_type(inode->i_sb, de, S_IFDIR); 2326 2327 return ext4_next_entry(de, blocksize); 2328 } 2329 2330 static int ext4_init_new_dir(handle_t *handle, struct inode *dir, 2331 struct inode *inode) 2332 { 2333 struct buffer_head *dir_block = NULL; 2334 struct ext4_dir_entry_2 *de; 2335 struct ext4_dir_entry_tail *t; 2336 ext4_lblk_t block = 0; 2337 unsigned int blocksize = dir->i_sb->s_blocksize; 2338 int csum_size = 0; 2339 int err; 2340 2341 if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb, 2342 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) 2343 csum_size = sizeof(struct ext4_dir_entry_tail); 2344 2345 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) { 2346 err = ext4_try_create_inline_dir(handle, dir, inode); 2347 if (err < 0 && err != -ENOSPC) 2348 goto out; 2349 if (!err) 2350 goto out; 2351 } 2352 2353 inode->i_size = 0; 2354 dir_block = ext4_append(handle, inode, &block); 2355 if (IS_ERR(dir_block)) 2356 return PTR_ERR(dir_block); 2357 BUFFER_TRACE(dir_block, "get_write_access"); 2358 err = ext4_journal_get_write_access(handle, dir_block); 2359 if (err) 2360 goto out; 2361 de = (struct ext4_dir_entry_2 *)dir_block->b_data; 2362 ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0); 2363 set_nlink(inode, 2); 2364 if (csum_size) { 2365 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize); 2366 initialize_dirent_tail(t, blocksize); 2367 } 2368 2369 BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata"); 2370 err = ext4_handle_dirty_dirent_node(handle, inode, dir_block); 2371 if (err) 2372 goto out; 2373 set_buffer_verified(dir_block); 2374 out: 2375 brelse(dir_block); 2376 return err; 2377 } 2378 2379 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) 2380 { 2381 handle_t *handle; 2382 struct inode *inode; 2383 int err, credits, retries = 0; 2384 2385 if (EXT4_DIR_LINK_MAX(dir)) 2386 return -EMLINK; 2387 2388 dquot_initialize(dir); 2389 2390 credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2391 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); 2392 retry: 2393 inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode, 2394 &dentry->d_name, 2395 0, NULL, EXT4_HT_DIR, credits); 2396 handle = ext4_journal_current_handle(); 2397 err = PTR_ERR(inode); 2398 if (IS_ERR(inode)) 2399 goto out_stop; 2400 2401 inode->i_op = &ext4_dir_inode_operations; 2402 inode->i_fop = &ext4_dir_operations; 2403 err = ext4_init_new_dir(handle, dir, inode); 2404 if (err) 2405 goto out_clear_inode; 2406 err = ext4_mark_inode_dirty(handle, inode); 2407 if (!err) 2408 err = ext4_add_entry(handle, dentry, inode); 2409 if (err) { 2410 out_clear_inode: 2411 clear_nlink(inode); 2412 unlock_new_inode(inode); 2413 ext4_mark_inode_dirty(handle, inode); 2414 iput(inode); 2415 goto out_stop; 2416 } 2417 ext4_inc_count(handle, dir); 2418 ext4_update_dx_flag(dir); 2419 err = ext4_mark_inode_dirty(handle, dir); 2420 if (err) 2421 goto out_clear_inode; 2422 unlock_new_inode(inode); 2423 d_instantiate(dentry, inode); 2424 if (IS_DIRSYNC(dir)) 2425 ext4_handle_sync(handle); 2426 2427 out_stop: 2428 if (handle) 2429 ext4_journal_stop(handle); 2430 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2431 goto retry; 2432 return err; 2433 } 2434 2435 /* 2436 * routine to check that the specified directory is empty (for rmdir) 2437 */ 2438 static int empty_dir(struct inode *inode) 2439 { 2440 unsigned int offset; 2441 struct buffer_head *bh; 2442 struct ext4_dir_entry_2 *de, *de1; 2443 struct super_block *sb; 2444 int err = 0; 2445 2446 if (ext4_has_inline_data(inode)) { 2447 int has_inline_data = 1; 2448 2449 err = empty_inline_dir(inode, &has_inline_data); 2450 if (has_inline_data) 2451 return err; 2452 } 2453 2454 sb = inode->i_sb; 2455 if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) { 2456 EXT4_ERROR_INODE(inode, "invalid size"); 2457 return 1; 2458 } 2459 bh = ext4_read_dirblock(inode, 0, EITHER); 2460 if (IS_ERR(bh)) 2461 return 1; 2462 2463 de = (struct ext4_dir_entry_2 *) bh->b_data; 2464 de1 = ext4_next_entry(de, sb->s_blocksize); 2465 if (le32_to_cpu(de->inode) != inode->i_ino || 2466 !le32_to_cpu(de1->inode) || 2467 strcmp(".", de->name) || 2468 strcmp("..", de1->name)) { 2469 ext4_warning(inode->i_sb, 2470 "bad directory (dir #%lu) - no `.' or `..'", 2471 inode->i_ino); 2472 brelse(bh); 2473 return 1; 2474 } 2475 offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) + 2476 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize); 2477 de = ext4_next_entry(de1, sb->s_blocksize); 2478 while (offset < inode->i_size) { 2479 if (!bh || 2480 (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) { 2481 unsigned int lblock; 2482 err = 0; 2483 brelse(bh); 2484 lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb); 2485 bh = ext4_read_dirblock(inode, lblock, EITHER); 2486 if (IS_ERR(bh)) 2487 return 1; 2488 de = (struct ext4_dir_entry_2 *) bh->b_data; 2489 } 2490 if (ext4_check_dir_entry(inode, NULL, de, bh, 2491 bh->b_data, bh->b_size, offset)) { 2492 de = (struct ext4_dir_entry_2 *)(bh->b_data + 2493 sb->s_blocksize); 2494 offset = (offset | (sb->s_blocksize - 1)) + 1; 2495 continue; 2496 } 2497 if (le32_to_cpu(de->inode)) { 2498 brelse(bh); 2499 return 0; 2500 } 2501 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); 2502 de = ext4_next_entry(de, sb->s_blocksize); 2503 } 2504 brelse(bh); 2505 return 1; 2506 } 2507 2508 /* ext4_orphan_add() links an unlinked or truncated inode into a list of 2509 * such inodes, starting at the superblock, in case we crash before the 2510 * file is closed/deleted, or in case the inode truncate spans multiple 2511 * transactions and the last transaction is not recovered after a crash. 2512 * 2513 * At filesystem recovery time, we walk this list deleting unlinked 2514 * inodes and truncating linked inodes in ext4_orphan_cleanup(). 2515 */ 2516 int ext4_orphan_add(handle_t *handle, struct inode *inode) 2517 { 2518 struct super_block *sb = inode->i_sb; 2519 struct ext4_iloc iloc; 2520 int err = 0, rc; 2521 2522 if (!EXT4_SB(sb)->s_journal) 2523 return 0; 2524 2525 mutex_lock(&EXT4_SB(sb)->s_orphan_lock); 2526 if (!list_empty(&EXT4_I(inode)->i_orphan)) 2527 goto out_unlock; 2528 2529 /* 2530 * Orphan handling is only valid for files with data blocks 2531 * being truncated, or files being unlinked. Note that we either 2532 * hold i_mutex, or the inode can not be referenced from outside, 2533 * so i_nlink should not be bumped due to race 2534 */ 2535 J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 2536 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0); 2537 2538 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access"); 2539 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh); 2540 if (err) 2541 goto out_unlock; 2542 2543 err = ext4_reserve_inode_write(handle, inode, &iloc); 2544 if (err) 2545 goto out_unlock; 2546 /* 2547 * Due to previous errors inode may be already a part of on-disk 2548 * orphan list. If so skip on-disk list modification. 2549 */ 2550 if (NEXT_ORPHAN(inode) && NEXT_ORPHAN(inode) <= 2551 (le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))) 2552 goto mem_insert; 2553 2554 /* Insert this inode at the head of the on-disk orphan list... */ 2555 NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan); 2556 EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino); 2557 err = ext4_handle_dirty_super(handle, sb); 2558 rc = ext4_mark_iloc_dirty(handle, inode, &iloc); 2559 if (!err) 2560 err = rc; 2561 2562 /* Only add to the head of the in-memory list if all the 2563 * previous operations succeeded. If the orphan_add is going to 2564 * fail (possibly taking the journal offline), we can't risk 2565 * leaving the inode on the orphan list: stray orphan-list 2566 * entries can cause panics at unmount time. 2567 * 2568 * This is safe: on error we're going to ignore the orphan list 2569 * anyway on the next recovery. */ 2570 mem_insert: 2571 if (!err) 2572 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan); 2573 2574 jbd_debug(4, "superblock will point to %lu\n", inode->i_ino); 2575 jbd_debug(4, "orphan inode %lu will point to %d\n", 2576 inode->i_ino, NEXT_ORPHAN(inode)); 2577 out_unlock: 2578 mutex_unlock(&EXT4_SB(sb)->s_orphan_lock); 2579 ext4_std_error(inode->i_sb, err); 2580 return err; 2581 } 2582 2583 /* 2584 * ext4_orphan_del() removes an unlinked or truncated inode from the list 2585 * of such inodes stored on disk, because it is finally being cleaned up. 2586 */ 2587 int ext4_orphan_del(handle_t *handle, struct inode *inode) 2588 { 2589 struct list_head *prev; 2590 struct ext4_inode_info *ei = EXT4_I(inode); 2591 struct ext4_sb_info *sbi; 2592 __u32 ino_next; 2593 struct ext4_iloc iloc; 2594 int err = 0; 2595 2596 if ((!EXT4_SB(inode->i_sb)->s_journal) && 2597 !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) 2598 return 0; 2599 2600 mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock); 2601 if (list_empty(&ei->i_orphan)) 2602 goto out; 2603 2604 ino_next = NEXT_ORPHAN(inode); 2605 prev = ei->i_orphan.prev; 2606 sbi = EXT4_SB(inode->i_sb); 2607 2608 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino); 2609 2610 list_del_init(&ei->i_orphan); 2611 2612 /* If we're on an error path, we may not have a valid 2613 * transaction handle with which to update the orphan list on 2614 * disk, but we still need to remove the inode from the linked 2615 * list in memory. */ 2616 if (!handle) 2617 goto out; 2618 2619 err = ext4_reserve_inode_write(handle, inode, &iloc); 2620 if (err) 2621 goto out_err; 2622 2623 if (prev == &sbi->s_orphan) { 2624 jbd_debug(4, "superblock will point to %u\n", ino_next); 2625 BUFFER_TRACE(sbi->s_sbh, "get_write_access"); 2626 err = ext4_journal_get_write_access(handle, sbi->s_sbh); 2627 if (err) 2628 goto out_brelse; 2629 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next); 2630 err = ext4_handle_dirty_super(handle, inode->i_sb); 2631 } else { 2632 struct ext4_iloc iloc2; 2633 struct inode *i_prev = 2634 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode; 2635 2636 jbd_debug(4, "orphan inode %lu will point to %u\n", 2637 i_prev->i_ino, ino_next); 2638 err = ext4_reserve_inode_write(handle, i_prev, &iloc2); 2639 if (err) 2640 goto out_brelse; 2641 NEXT_ORPHAN(i_prev) = ino_next; 2642 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2); 2643 } 2644 if (err) 2645 goto out_brelse; 2646 NEXT_ORPHAN(inode) = 0; 2647 err = ext4_mark_iloc_dirty(handle, inode, &iloc); 2648 2649 out_err: 2650 ext4_std_error(inode->i_sb, err); 2651 out: 2652 mutex_unlock(&EXT4_SB(inode->i_sb)->s_orphan_lock); 2653 return err; 2654 2655 out_brelse: 2656 brelse(iloc.bh); 2657 goto out_err; 2658 } 2659 2660 static int ext4_rmdir(struct inode *dir, struct dentry *dentry) 2661 { 2662 int retval; 2663 struct inode *inode; 2664 struct buffer_head *bh; 2665 struct ext4_dir_entry_2 *de; 2666 handle_t *handle = NULL; 2667 2668 /* Initialize quotas before so that eventual writes go in 2669 * separate transaction */ 2670 dquot_initialize(dir); 2671 dquot_initialize(dentry->d_inode); 2672 2673 retval = -ENOENT; 2674 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); 2675 if (!bh) 2676 goto end_rmdir; 2677 2678 inode = dentry->d_inode; 2679 2680 retval = -EIO; 2681 if (le32_to_cpu(de->inode) != inode->i_ino) 2682 goto end_rmdir; 2683 2684 retval = -ENOTEMPTY; 2685 if (!empty_dir(inode)) 2686 goto end_rmdir; 2687 2688 handle = ext4_journal_start(dir, EXT4_HT_DIR, 2689 EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); 2690 if (IS_ERR(handle)) { 2691 retval = PTR_ERR(handle); 2692 handle = NULL; 2693 goto end_rmdir; 2694 } 2695 2696 if (IS_DIRSYNC(dir)) 2697 ext4_handle_sync(handle); 2698 2699 retval = ext4_delete_entry(handle, dir, de, bh); 2700 if (retval) 2701 goto end_rmdir; 2702 if (!EXT4_DIR_LINK_EMPTY(inode)) 2703 ext4_warning(inode->i_sb, 2704 "empty directory has too many links (%d)", 2705 inode->i_nlink); 2706 inode->i_version++; 2707 clear_nlink(inode); 2708 /* There's no need to set i_disksize: the fact that i_nlink is 2709 * zero will ensure that the right thing happens during any 2710 * recovery. */ 2711 inode->i_size = 0; 2712 ext4_orphan_add(handle, inode); 2713 inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode); 2714 ext4_mark_inode_dirty(handle, inode); 2715 ext4_dec_count(handle, dir); 2716 ext4_update_dx_flag(dir); 2717 ext4_mark_inode_dirty(handle, dir); 2718 2719 end_rmdir: 2720 brelse(bh); 2721 if (handle) 2722 ext4_journal_stop(handle); 2723 return retval; 2724 } 2725 2726 static int ext4_unlink(struct inode *dir, struct dentry *dentry) 2727 { 2728 int retval; 2729 struct inode *inode; 2730 struct buffer_head *bh; 2731 struct ext4_dir_entry_2 *de; 2732 handle_t *handle = NULL; 2733 2734 trace_ext4_unlink_enter(dir, dentry); 2735 /* Initialize quotas before so that eventual writes go 2736 * in separate transaction */ 2737 dquot_initialize(dir); 2738 dquot_initialize(dentry->d_inode); 2739 2740 retval = -ENOENT; 2741 bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); 2742 if (!bh) 2743 goto end_unlink; 2744 2745 inode = dentry->d_inode; 2746 2747 retval = -EIO; 2748 if (le32_to_cpu(de->inode) != inode->i_ino) 2749 goto end_unlink; 2750 2751 handle = ext4_journal_start(dir, EXT4_HT_DIR, 2752 EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); 2753 if (IS_ERR(handle)) { 2754 retval = PTR_ERR(handle); 2755 handle = NULL; 2756 goto end_unlink; 2757 } 2758 2759 if (IS_DIRSYNC(dir)) 2760 ext4_handle_sync(handle); 2761 2762 if (!inode->i_nlink) { 2763 ext4_warning(inode->i_sb, 2764 "Deleting nonexistent file (%lu), %d", 2765 inode->i_ino, inode->i_nlink); 2766 set_nlink(inode, 1); 2767 } 2768 retval = ext4_delete_entry(handle, dir, de, bh); 2769 if (retval) 2770 goto end_unlink; 2771 dir->i_ctime = dir->i_mtime = ext4_current_time(dir); 2772 ext4_update_dx_flag(dir); 2773 ext4_mark_inode_dirty(handle, dir); 2774 drop_nlink(inode); 2775 if (!inode->i_nlink) 2776 ext4_orphan_add(handle, inode); 2777 inode->i_ctime = ext4_current_time(inode); 2778 ext4_mark_inode_dirty(handle, inode); 2779 retval = 0; 2780 2781 end_unlink: 2782 brelse(bh); 2783 if (handle) 2784 ext4_journal_stop(handle); 2785 trace_ext4_unlink_exit(dentry, retval); 2786 return retval; 2787 } 2788 2789 static int ext4_symlink(struct inode *dir, 2790 struct dentry *dentry, const char *symname) 2791 { 2792 handle_t *handle; 2793 struct inode *inode; 2794 int l, err, retries = 0; 2795 int credits; 2796 2797 l = strlen(symname)+1; 2798 if (l > dir->i_sb->s_blocksize) 2799 return -ENAMETOOLONG; 2800 2801 dquot_initialize(dir); 2802 2803 if (l > EXT4_N_BLOCKS * 4) { 2804 /* 2805 * For non-fast symlinks, we just allocate inode and put it on 2806 * orphan list in the first transaction => we need bitmap, 2807 * group descriptor, sb, inode block, quota blocks, and 2808 * possibly selinux xattr blocks. 2809 */ 2810 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) + 2811 EXT4_XATTR_TRANS_BLOCKS; 2812 } else { 2813 /* 2814 * Fast symlink. We have to add entry to directory 2815 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS), 2816 * allocate new inode (bitmap, group descriptor, inode block, 2817 * quota blocks, sb is already counted in previous macros). 2818 */ 2819 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2820 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3; 2821 } 2822 retry: 2823 inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO, 2824 &dentry->d_name, 0, NULL, 2825 EXT4_HT_DIR, credits); 2826 handle = ext4_journal_current_handle(); 2827 err = PTR_ERR(inode); 2828 if (IS_ERR(inode)) 2829 goto out_stop; 2830 2831 if (l > EXT4_N_BLOCKS * 4) { 2832 inode->i_op = &ext4_symlink_inode_operations; 2833 ext4_set_aops(inode); 2834 /* 2835 * We cannot call page_symlink() with transaction started 2836 * because it calls into ext4_write_begin() which can wait 2837 * for transaction commit if we are running out of space 2838 * and thus we deadlock. So we have to stop transaction now 2839 * and restart it when symlink contents is written. 2840 * 2841 * To keep fs consistent in case of crash, we have to put inode 2842 * to orphan list in the mean time. 2843 */ 2844 drop_nlink(inode); 2845 err = ext4_orphan_add(handle, inode); 2846 ext4_journal_stop(handle); 2847 if (err) 2848 goto err_drop_inode; 2849 err = __page_symlink(inode, symname, l, 1); 2850 if (err) 2851 goto err_drop_inode; 2852 /* 2853 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS 2854 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified 2855 */ 2856 handle = ext4_journal_start(dir, EXT4_HT_DIR, 2857 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2858 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1); 2859 if (IS_ERR(handle)) { 2860 err = PTR_ERR(handle); 2861 goto err_drop_inode; 2862 } 2863 set_nlink(inode, 1); 2864 err = ext4_orphan_del(handle, inode); 2865 if (err) { 2866 ext4_journal_stop(handle); 2867 clear_nlink(inode); 2868 goto err_drop_inode; 2869 } 2870 } else { 2871 /* clear the extent format for fast symlink */ 2872 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS); 2873 inode->i_op = &ext4_fast_symlink_inode_operations; 2874 memcpy((char *)&EXT4_I(inode)->i_data, symname, l); 2875 inode->i_size = l-1; 2876 } 2877 EXT4_I(inode)->i_disksize = inode->i_size; 2878 err = ext4_add_nondir(handle, dentry, inode); 2879 if (!err && IS_DIRSYNC(dir)) 2880 ext4_handle_sync(handle); 2881 2882 out_stop: 2883 if (handle) 2884 ext4_journal_stop(handle); 2885 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2886 goto retry; 2887 return err; 2888 err_drop_inode: 2889 unlock_new_inode(inode); 2890 iput(inode); 2891 return err; 2892 } 2893 2894 static int ext4_link(struct dentry *old_dentry, 2895 struct inode *dir, struct dentry *dentry) 2896 { 2897 handle_t *handle; 2898 struct inode *inode = old_dentry->d_inode; 2899 int err, retries = 0; 2900 2901 if (inode->i_nlink >= EXT4_LINK_MAX) 2902 return -EMLINK; 2903 2904 dquot_initialize(dir); 2905 2906 retry: 2907 handle = ext4_journal_start(dir, EXT4_HT_DIR, 2908 (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2909 EXT4_INDEX_EXTRA_TRANS_BLOCKS)); 2910 if (IS_ERR(handle)) 2911 return PTR_ERR(handle); 2912 2913 if (IS_DIRSYNC(dir)) 2914 ext4_handle_sync(handle); 2915 2916 inode->i_ctime = ext4_current_time(inode); 2917 ext4_inc_count(handle, inode); 2918 ihold(inode); 2919 2920 err = ext4_add_entry(handle, dentry, inode); 2921 if (!err) { 2922 ext4_mark_inode_dirty(handle, inode); 2923 d_instantiate(dentry, inode); 2924 } else { 2925 drop_nlink(inode); 2926 iput(inode); 2927 } 2928 ext4_journal_stop(handle); 2929 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2930 goto retry; 2931 return err; 2932 } 2933 2934 2935 /* 2936 * Try to find buffer head where contains the parent block. 2937 * It should be the inode block if it is inlined or the 1st block 2938 * if it is a normal dir. 2939 */ 2940 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle, 2941 struct inode *inode, 2942 int *retval, 2943 struct ext4_dir_entry_2 **parent_de, 2944 int *inlined) 2945 { 2946 struct buffer_head *bh; 2947 2948 if (!ext4_has_inline_data(inode)) { 2949 bh = ext4_read_dirblock(inode, 0, EITHER); 2950 if (IS_ERR(bh)) { 2951 *retval = PTR_ERR(bh); 2952 return NULL; 2953 } 2954 *parent_de = ext4_next_entry( 2955 (struct ext4_dir_entry_2 *)bh->b_data, 2956 inode->i_sb->s_blocksize); 2957 return bh; 2958 } 2959 2960 *inlined = 1; 2961 return ext4_get_first_inline_block(inode, parent_de, retval); 2962 } 2963 2964 /* 2965 * Anybody can rename anything with this: the permission checks are left to the 2966 * higher-level routines. 2967 */ 2968 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry, 2969 struct inode *new_dir, struct dentry *new_dentry) 2970 { 2971 handle_t *handle; 2972 struct inode *old_inode, *new_inode; 2973 struct buffer_head *old_bh, *new_bh, *dir_bh; 2974 struct ext4_dir_entry_2 *old_de, *new_de; 2975 int retval, force_da_alloc = 0; 2976 int inlined = 0, new_inlined = 0; 2977 struct ext4_dir_entry_2 *parent_de; 2978 2979 dquot_initialize(old_dir); 2980 dquot_initialize(new_dir); 2981 2982 old_bh = new_bh = dir_bh = NULL; 2983 2984 /* Initialize quotas before so that eventual writes go 2985 * in separate transaction */ 2986 if (new_dentry->d_inode) 2987 dquot_initialize(new_dentry->d_inode); 2988 handle = ext4_journal_start(old_dir, EXT4_HT_DIR, 2989 (2 * EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) + 2990 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2)); 2991 if (IS_ERR(handle)) 2992 return PTR_ERR(handle); 2993 2994 if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir)) 2995 ext4_handle_sync(handle); 2996 2997 old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de, NULL); 2998 /* 2999 * Check for inode number is _not_ due to possible IO errors. 3000 * We might rmdir the source, keep it as pwd of some process 3001 * and merrily kill the link to whatever was created under the 3002 * same name. Goodbye sticky bit ;-< 3003 */ 3004 old_inode = old_dentry->d_inode; 3005 retval = -ENOENT; 3006 if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino) 3007 goto end_rename; 3008 3009 new_inode = new_dentry->d_inode; 3010 new_bh = ext4_find_entry(new_dir, &new_dentry->d_name, 3011 &new_de, &new_inlined); 3012 if (new_bh) { 3013 if (!new_inode) { 3014 brelse(new_bh); 3015 new_bh = NULL; 3016 } 3017 } 3018 if (S_ISDIR(old_inode->i_mode)) { 3019 if (new_inode) { 3020 retval = -ENOTEMPTY; 3021 if (!empty_dir(new_inode)) 3022 goto end_rename; 3023 } 3024 retval = -EIO; 3025 dir_bh = ext4_get_first_dir_block(handle, old_inode, 3026 &retval, &parent_de, 3027 &inlined); 3028 if (!dir_bh) 3029 goto end_rename; 3030 if (le32_to_cpu(parent_de->inode) != old_dir->i_ino) 3031 goto end_rename; 3032 retval = -EMLINK; 3033 if (!new_inode && new_dir != old_dir && 3034 EXT4_DIR_LINK_MAX(new_dir)) 3035 goto end_rename; 3036 BUFFER_TRACE(dir_bh, "get_write_access"); 3037 retval = ext4_journal_get_write_access(handle, dir_bh); 3038 if (retval) 3039 goto end_rename; 3040 } 3041 if (!new_bh) { 3042 retval = ext4_add_entry(handle, new_dentry, old_inode); 3043 if (retval) 3044 goto end_rename; 3045 } else { 3046 BUFFER_TRACE(new_bh, "get write access"); 3047 retval = ext4_journal_get_write_access(handle, new_bh); 3048 if (retval) 3049 goto end_rename; 3050 new_de->inode = cpu_to_le32(old_inode->i_ino); 3051 if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb, 3052 EXT4_FEATURE_INCOMPAT_FILETYPE)) 3053 new_de->file_type = old_de->file_type; 3054 new_dir->i_version++; 3055 new_dir->i_ctime = new_dir->i_mtime = 3056 ext4_current_time(new_dir); 3057 ext4_mark_inode_dirty(handle, new_dir); 3058 BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata"); 3059 if (!new_inlined) { 3060 retval = ext4_handle_dirty_dirent_node(handle, 3061 new_dir, new_bh); 3062 if (unlikely(retval)) { 3063 ext4_std_error(new_dir->i_sb, retval); 3064 goto end_rename; 3065 } 3066 } 3067 brelse(new_bh); 3068 new_bh = NULL; 3069 } 3070 3071 /* 3072 * Like most other Unix systems, set the ctime for inodes on a 3073 * rename. 3074 */ 3075 old_inode->i_ctime = ext4_current_time(old_inode); 3076 ext4_mark_inode_dirty(handle, old_inode); 3077 3078 /* 3079 * ok, that's it 3080 */ 3081 if (le32_to_cpu(old_de->inode) != old_inode->i_ino || 3082 old_de->name_len != old_dentry->d_name.len || 3083 strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) || 3084 (retval = ext4_delete_entry(handle, old_dir, 3085 old_de, old_bh)) == -ENOENT) { 3086 /* old_de could have moved from under us during htree split, so 3087 * make sure that we are deleting the right entry. We might 3088 * also be pointing to a stale entry in the unused part of 3089 * old_bh so just checking inum and the name isn't enough. */ 3090 struct buffer_head *old_bh2; 3091 struct ext4_dir_entry_2 *old_de2; 3092 3093 old_bh2 = ext4_find_entry(old_dir, &old_dentry->d_name, 3094 &old_de2, NULL); 3095 if (old_bh2) { 3096 retval = ext4_delete_entry(handle, old_dir, 3097 old_de2, old_bh2); 3098 brelse(old_bh2); 3099 } 3100 } 3101 if (retval) { 3102 ext4_warning(old_dir->i_sb, 3103 "Deleting old file (%lu), %d, error=%d", 3104 old_dir->i_ino, old_dir->i_nlink, retval); 3105 } 3106 3107 if (new_inode) { 3108 ext4_dec_count(handle, new_inode); 3109 new_inode->i_ctime = ext4_current_time(new_inode); 3110 } 3111 old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir); 3112 ext4_update_dx_flag(old_dir); 3113 if (dir_bh) { 3114 parent_de->inode = cpu_to_le32(new_dir->i_ino); 3115 BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata"); 3116 if (!inlined) { 3117 if (is_dx(old_inode)) { 3118 retval = ext4_handle_dirty_dx_node(handle, 3119 old_inode, 3120 dir_bh); 3121 } else { 3122 retval = ext4_handle_dirty_dirent_node(handle, 3123 old_inode, dir_bh); 3124 } 3125 } else { 3126 retval = ext4_mark_inode_dirty(handle, old_inode); 3127 } 3128 if (retval) { 3129 ext4_std_error(old_dir->i_sb, retval); 3130 goto end_rename; 3131 } 3132 ext4_dec_count(handle, old_dir); 3133 if (new_inode) { 3134 /* checked empty_dir above, can't have another parent, 3135 * ext4_dec_count() won't work for many-linked dirs */ 3136 clear_nlink(new_inode); 3137 } else { 3138 ext4_inc_count(handle, new_dir); 3139 ext4_update_dx_flag(new_dir); 3140 ext4_mark_inode_dirty(handle, new_dir); 3141 } 3142 } 3143 ext4_mark_inode_dirty(handle, old_dir); 3144 if (new_inode) { 3145 ext4_mark_inode_dirty(handle, new_inode); 3146 if (!new_inode->i_nlink) 3147 ext4_orphan_add(handle, new_inode); 3148 if (!test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC)) 3149 force_da_alloc = 1; 3150 } 3151 retval = 0; 3152 3153 end_rename: 3154 brelse(dir_bh); 3155 brelse(old_bh); 3156 brelse(new_bh); 3157 ext4_journal_stop(handle); 3158 if (retval == 0 && force_da_alloc) 3159 ext4_alloc_da_blocks(old_inode); 3160 return retval; 3161 } 3162 3163 /* 3164 * directories can handle most operations... 3165 */ 3166 const struct inode_operations ext4_dir_inode_operations = { 3167 .create = ext4_create, 3168 .lookup = ext4_lookup, 3169 .link = ext4_link, 3170 .unlink = ext4_unlink, 3171 .symlink = ext4_symlink, 3172 .mkdir = ext4_mkdir, 3173 .rmdir = ext4_rmdir, 3174 .mknod = ext4_mknod, 3175 .rename = ext4_rename, 3176 .setattr = ext4_setattr, 3177 .setxattr = generic_setxattr, 3178 .getxattr = generic_getxattr, 3179 .listxattr = ext4_listxattr, 3180 .removexattr = generic_removexattr, 3181 .get_acl = ext4_get_acl, 3182 .fiemap = ext4_fiemap, 3183 }; 3184 3185 const struct inode_operations ext4_special_inode_operations = { 3186 .setattr = ext4_setattr, 3187 .setxattr = generic_setxattr, 3188 .getxattr = generic_getxattr, 3189 .listxattr = ext4_listxattr, 3190 .removexattr = generic_removexattr, 3191 .get_acl = ext4_get_acl, 3192 }; 3193