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/ext4_fs.h> 32 #include <linux/ext4_jbd2.h> 33 #include <linux/fcntl.h> 34 #include <linux/stat.h> 35 #include <linux/string.h> 36 #include <linux/quotaops.h> 37 #include <linux/buffer_head.h> 38 #include <linux/bio.h> 39 40 #include "namei.h" 41 #include "xattr.h" 42 #include "acl.h" 43 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 #define NAMEI_RA_INDEX(c,b) (((c) * NAMEI_RA_BLOCKS) + (b)) 51 52 static struct buffer_head *ext4_append(handle_t *handle, 53 struct inode *inode, 54 u32 *block, int *err) 55 { 56 struct buffer_head *bh; 57 58 *block = inode->i_size >> inode->i_sb->s_blocksize_bits; 59 60 if ((bh = ext4_bread(handle, inode, *block, 1, err))) { 61 inode->i_size += inode->i_sb->s_blocksize; 62 EXT4_I(inode)->i_disksize = inode->i_size; 63 ext4_journal_get_write_access(handle,bh); 64 } 65 return bh; 66 } 67 68 #ifndef assert 69 #define assert(test) J_ASSERT(test) 70 #endif 71 72 #ifndef swap 73 #define swap(x, y) do { typeof(x) z = x; x = y; y = z; } while (0) 74 #endif 75 76 #ifdef DX_DEBUG 77 #define dxtrace(command) command 78 #else 79 #define dxtrace(command) 80 #endif 81 82 struct fake_dirent 83 { 84 __le32 inode; 85 __le16 rec_len; 86 u8 name_len; 87 u8 file_type; 88 }; 89 90 struct dx_countlimit 91 { 92 __le16 limit; 93 __le16 count; 94 }; 95 96 struct dx_entry 97 { 98 __le32 hash; 99 __le32 block; 100 }; 101 102 /* 103 * dx_root_info is laid out so that if it should somehow get overlaid by a 104 * dirent the two low bits of the hash version will be zero. Therefore, the 105 * hash version mod 4 should never be 0. Sincerely, the paranoia department. 106 */ 107 108 struct dx_root 109 { 110 struct fake_dirent dot; 111 char dot_name[4]; 112 struct fake_dirent dotdot; 113 char dotdot_name[4]; 114 struct dx_root_info 115 { 116 __le32 reserved_zero; 117 u8 hash_version; 118 u8 info_length; /* 8 */ 119 u8 indirect_levels; 120 u8 unused_flags; 121 } 122 info; 123 struct dx_entry entries[0]; 124 }; 125 126 struct dx_node 127 { 128 struct fake_dirent fake; 129 struct dx_entry entries[0]; 130 }; 131 132 133 struct dx_frame 134 { 135 struct buffer_head *bh; 136 struct dx_entry *entries; 137 struct dx_entry *at; 138 }; 139 140 struct dx_map_entry 141 { 142 u32 hash; 143 u32 offs; 144 }; 145 146 #ifdef CONFIG_EXT4_INDEX 147 static inline unsigned dx_get_block (struct dx_entry *entry); 148 static void dx_set_block (struct dx_entry *entry, unsigned value); 149 static inline unsigned dx_get_hash (struct dx_entry *entry); 150 static void dx_set_hash (struct dx_entry *entry, unsigned value); 151 static unsigned dx_get_count (struct dx_entry *entries); 152 static unsigned dx_get_limit (struct dx_entry *entries); 153 static void dx_set_count (struct dx_entry *entries, unsigned value); 154 static void dx_set_limit (struct dx_entry *entries, unsigned value); 155 static unsigned dx_root_limit (struct inode *dir, unsigned infosize); 156 static unsigned dx_node_limit (struct inode *dir); 157 static struct dx_frame *dx_probe(struct dentry *dentry, 158 struct inode *dir, 159 struct dx_hash_info *hinfo, 160 struct dx_frame *frame, 161 int *err); 162 static void dx_release (struct dx_frame *frames); 163 static int dx_make_map (struct ext4_dir_entry_2 *de, int size, 164 struct dx_hash_info *hinfo, struct dx_map_entry map[]); 165 static void dx_sort_map(struct dx_map_entry *map, unsigned count); 166 static struct ext4_dir_entry_2 *dx_move_dirents (char *from, char *to, 167 struct dx_map_entry *offsets, int count); 168 static struct ext4_dir_entry_2* dx_pack_dirents (char *base, int size); 169 static void dx_insert_block (struct dx_frame *frame, u32 hash, u32 block); 170 static int ext4_htree_next_block(struct inode *dir, __u32 hash, 171 struct dx_frame *frame, 172 struct dx_frame *frames, 173 __u32 *start_hash); 174 static struct buffer_head * ext4_dx_find_entry(struct dentry *dentry, 175 struct ext4_dir_entry_2 **res_dir, int *err); 176 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry, 177 struct inode *inode); 178 179 /* 180 * Future: use high four bits of block for coalesce-on-delete flags 181 * Mask them off for now. 182 */ 183 184 static inline unsigned dx_get_block (struct dx_entry *entry) 185 { 186 return le32_to_cpu(entry->block) & 0x00ffffff; 187 } 188 189 static inline void dx_set_block (struct dx_entry *entry, unsigned value) 190 { 191 entry->block = cpu_to_le32(value); 192 } 193 194 static inline unsigned dx_get_hash (struct dx_entry *entry) 195 { 196 return le32_to_cpu(entry->hash); 197 } 198 199 static inline void dx_set_hash (struct dx_entry *entry, unsigned value) 200 { 201 entry->hash = cpu_to_le32(value); 202 } 203 204 static inline unsigned dx_get_count (struct dx_entry *entries) 205 { 206 return le16_to_cpu(((struct dx_countlimit *) entries)->count); 207 } 208 209 static inline unsigned dx_get_limit (struct dx_entry *entries) 210 { 211 return le16_to_cpu(((struct dx_countlimit *) entries)->limit); 212 } 213 214 static inline void dx_set_count (struct dx_entry *entries, unsigned value) 215 { 216 ((struct dx_countlimit *) entries)->count = cpu_to_le16(value); 217 } 218 219 static inline void dx_set_limit (struct dx_entry *entries, unsigned value) 220 { 221 ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value); 222 } 223 224 static inline unsigned dx_root_limit (struct inode *dir, unsigned infosize) 225 { 226 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) - 227 EXT4_DIR_REC_LEN(2) - infosize; 228 return 0? 20: entry_space / sizeof(struct dx_entry); 229 } 230 231 static inline unsigned dx_node_limit (struct inode *dir) 232 { 233 unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0); 234 return 0? 22: entry_space / sizeof(struct dx_entry); 235 } 236 237 /* 238 * Debug 239 */ 240 #ifdef DX_DEBUG 241 static void dx_show_index (char * label, struct dx_entry *entries) 242 { 243 int i, n = dx_get_count (entries); 244 printk("%s index ", label); 245 for (i = 0; i < n; i++) { 246 printk("%x->%u ", i? dx_get_hash(entries + i) : 247 0, dx_get_block(entries + i)); 248 } 249 printk("\n"); 250 } 251 252 struct stats 253 { 254 unsigned names; 255 unsigned space; 256 unsigned bcount; 257 }; 258 259 static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de, 260 int size, int show_names) 261 { 262 unsigned names = 0, space = 0; 263 char *base = (char *) de; 264 struct dx_hash_info h = *hinfo; 265 266 printk("names: "); 267 while ((char *) de < base + size) 268 { 269 if (de->inode) 270 { 271 if (show_names) 272 { 273 int len = de->name_len; 274 char *name = de->name; 275 while (len--) printk("%c", *name++); 276 ext4fs_dirhash(de->name, de->name_len, &h); 277 printk(":%x.%u ", h.hash, 278 ((char *) de - base)); 279 } 280 space += EXT4_DIR_REC_LEN(de->name_len); 281 names++; 282 } 283 de = (struct ext4_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len)); 284 } 285 printk("(%i)\n", names); 286 return (struct stats) { names, space, 1 }; 287 } 288 289 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir, 290 struct dx_entry *entries, int levels) 291 { 292 unsigned blocksize = dir->i_sb->s_blocksize; 293 unsigned count = dx_get_count (entries), names = 0, space = 0, i; 294 unsigned bcount = 0; 295 struct buffer_head *bh; 296 int err; 297 printk("%i indexed blocks...\n", count); 298 for (i = 0; i < count; i++, entries++) 299 { 300 u32 block = dx_get_block(entries), hash = i? dx_get_hash(entries): 0; 301 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash; 302 struct stats stats; 303 printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range); 304 if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue; 305 stats = levels? 306 dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1): 307 dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0); 308 names += stats.names; 309 space += stats.space; 310 bcount += stats.bcount; 311 brelse (bh); 312 } 313 if (bcount) 314 printk("%snames %u, fullness %u (%u%%)\n", levels?"":" ", 315 names, space/bcount,(space/bcount)*100/blocksize); 316 return (struct stats) { names, space, bcount}; 317 } 318 #endif /* DX_DEBUG */ 319 320 /* 321 * Probe for a directory leaf block to search. 322 * 323 * dx_probe can return ERR_BAD_DX_DIR, which means there was a format 324 * error in the directory index, and the caller should fall back to 325 * searching the directory normally. The callers of dx_probe **MUST** 326 * check for this error code, and make sure it never gets reflected 327 * back to userspace. 328 */ 329 static struct dx_frame * 330 dx_probe(struct dentry *dentry, struct inode *dir, 331 struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err) 332 { 333 unsigned count, indirect; 334 struct dx_entry *at, *entries, *p, *q, *m; 335 struct dx_root *root; 336 struct buffer_head *bh; 337 struct dx_frame *frame = frame_in; 338 u32 hash; 339 340 frame->bh = NULL; 341 if (dentry) 342 dir = dentry->d_parent->d_inode; 343 if (!(bh = ext4_bread (NULL,dir, 0, 0, err))) 344 goto fail; 345 root = (struct dx_root *) bh->b_data; 346 if (root->info.hash_version != DX_HASH_TEA && 347 root->info.hash_version != DX_HASH_HALF_MD4 && 348 root->info.hash_version != DX_HASH_LEGACY) { 349 ext4_warning(dir->i_sb, __FUNCTION__, 350 "Unrecognised inode hash code %d", 351 root->info.hash_version); 352 brelse(bh); 353 *err = ERR_BAD_DX_DIR; 354 goto fail; 355 } 356 hinfo->hash_version = root->info.hash_version; 357 hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed; 358 if (dentry) 359 ext4fs_dirhash(dentry->d_name.name, dentry->d_name.len, hinfo); 360 hash = hinfo->hash; 361 362 if (root->info.unused_flags & 1) { 363 ext4_warning(dir->i_sb, __FUNCTION__, 364 "Unimplemented inode hash flags: %#06x", 365 root->info.unused_flags); 366 brelse(bh); 367 *err = ERR_BAD_DX_DIR; 368 goto fail; 369 } 370 371 if ((indirect = root->info.indirect_levels) > 1) { 372 ext4_warning(dir->i_sb, __FUNCTION__, 373 "Unimplemented inode hash depth: %#06x", 374 root->info.indirect_levels); 375 brelse(bh); 376 *err = ERR_BAD_DX_DIR; 377 goto fail; 378 } 379 380 entries = (struct dx_entry *) (((char *)&root->info) + 381 root->info.info_length); 382 assert(dx_get_limit(entries) == dx_root_limit(dir, 383 root->info.info_length)); 384 dxtrace (printk("Look up %x", hash)); 385 while (1) 386 { 387 count = dx_get_count(entries); 388 assert (count && count <= dx_get_limit(entries)); 389 p = entries + 1; 390 q = entries + count - 1; 391 while (p <= q) 392 { 393 m = p + (q - p)/2; 394 dxtrace(printk(".")); 395 if (dx_get_hash(m) > hash) 396 q = m - 1; 397 else 398 p = m + 1; 399 } 400 401 if (0) // linear search cross check 402 { 403 unsigned n = count - 1; 404 at = entries; 405 while (n--) 406 { 407 dxtrace(printk(",")); 408 if (dx_get_hash(++at) > hash) 409 { 410 at--; 411 break; 412 } 413 } 414 assert (at == p - 1); 415 } 416 417 at = p - 1; 418 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at))); 419 frame->bh = bh; 420 frame->entries = entries; 421 frame->at = at; 422 if (!indirect--) return frame; 423 if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err))) 424 goto fail2; 425 at = entries = ((struct dx_node *) bh->b_data)->entries; 426 assert (dx_get_limit(entries) == dx_node_limit (dir)); 427 frame++; 428 } 429 fail2: 430 while (frame >= frame_in) { 431 brelse(frame->bh); 432 frame--; 433 } 434 fail: 435 return NULL; 436 } 437 438 static void dx_release (struct dx_frame *frames) 439 { 440 if (frames[0].bh == NULL) 441 return; 442 443 if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels) 444 brelse(frames[1].bh); 445 brelse(frames[0].bh); 446 } 447 448 /* 449 * This function increments the frame pointer to search the next leaf 450 * block, and reads in the necessary intervening nodes if the search 451 * should be necessary. Whether or not the search is necessary is 452 * controlled by the hash parameter. If the hash value is even, then 453 * the search is only continued if the next block starts with that 454 * hash value. This is used if we are searching for a specific file. 455 * 456 * If the hash value is HASH_NB_ALWAYS, then always go to the next block. 457 * 458 * This function returns 1 if the caller should continue to search, 459 * or 0 if it should not. If there is an error reading one of the 460 * index blocks, it will a negative error code. 461 * 462 * If start_hash is non-null, it will be filled in with the starting 463 * hash of the next page. 464 */ 465 static int ext4_htree_next_block(struct inode *dir, __u32 hash, 466 struct dx_frame *frame, 467 struct dx_frame *frames, 468 __u32 *start_hash) 469 { 470 struct dx_frame *p; 471 struct buffer_head *bh; 472 int err, num_frames = 0; 473 __u32 bhash; 474 475 p = frame; 476 /* 477 * Find the next leaf page by incrementing the frame pointer. 478 * If we run out of entries in the interior node, loop around and 479 * increment pointer in the parent node. When we break out of 480 * this loop, num_frames indicates the number of interior 481 * nodes need to be read. 482 */ 483 while (1) { 484 if (++(p->at) < p->entries + dx_get_count(p->entries)) 485 break; 486 if (p == frames) 487 return 0; 488 num_frames++; 489 p--; 490 } 491 492 /* 493 * If the hash is 1, then continue only if the next page has a 494 * continuation hash of any value. This is used for readdir 495 * handling. Otherwise, check to see if the hash matches the 496 * desired contiuation hash. If it doesn't, return since 497 * there's no point to read in the successive index pages. 498 */ 499 bhash = dx_get_hash(p->at); 500 if (start_hash) 501 *start_hash = bhash; 502 if ((hash & 1) == 0) { 503 if ((bhash & ~1) != hash) 504 return 0; 505 } 506 /* 507 * If the hash is HASH_NB_ALWAYS, we always go to the next 508 * block so no check is necessary 509 */ 510 while (num_frames--) { 511 if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at), 512 0, &err))) 513 return err; /* Failure */ 514 p++; 515 brelse (p->bh); 516 p->bh = bh; 517 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries; 518 } 519 return 1; 520 } 521 522 523 /* 524 * p is at least 6 bytes before the end of page 525 */ 526 static inline struct ext4_dir_entry_2 *ext4_next_entry(struct ext4_dir_entry_2 *p) 527 { 528 return (struct ext4_dir_entry_2 *)((char*)p + le16_to_cpu(p->rec_len)); 529 } 530 531 /* 532 * This function fills a red-black tree with information from a 533 * directory block. It returns the number directory entries loaded 534 * into the tree. If there is an error it is returned in err. 535 */ 536 static int htree_dirblock_to_tree(struct file *dir_file, 537 struct inode *dir, int block, 538 struct dx_hash_info *hinfo, 539 __u32 start_hash, __u32 start_minor_hash) 540 { 541 struct buffer_head *bh; 542 struct ext4_dir_entry_2 *de, *top; 543 int err, count = 0; 544 545 dxtrace(printk("In htree dirblock_to_tree: block %d\n", block)); 546 if (!(bh = ext4_bread (NULL, dir, block, 0, &err))) 547 return err; 548 549 de = (struct ext4_dir_entry_2 *) bh->b_data; 550 top = (struct ext4_dir_entry_2 *) ((char *) de + 551 dir->i_sb->s_blocksize - 552 EXT4_DIR_REC_LEN(0)); 553 for (; de < top; de = ext4_next_entry(de)) { 554 if (!ext4_check_dir_entry("htree_dirblock_to_tree", dir, de, bh, 555 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb)) 556 +((char *)de - bh->b_data))) { 557 /* On error, skip the f_pos to the next block. */ 558 dir_file->f_pos = (dir_file->f_pos | 559 (dir->i_sb->s_blocksize - 1)) + 1; 560 brelse (bh); 561 return count; 562 } 563 ext4fs_dirhash(de->name, de->name_len, hinfo); 564 if ((hinfo->hash < start_hash) || 565 ((hinfo->hash == start_hash) && 566 (hinfo->minor_hash < start_minor_hash))) 567 continue; 568 if (de->inode == 0) 569 continue; 570 if ((err = ext4_htree_store_dirent(dir_file, 571 hinfo->hash, hinfo->minor_hash, de)) != 0) { 572 brelse(bh); 573 return err; 574 } 575 count++; 576 } 577 brelse(bh); 578 return count; 579 } 580 581 582 /* 583 * This function fills a red-black tree with information from a 584 * directory. We start scanning the directory in hash order, starting 585 * at start_hash and start_minor_hash. 586 * 587 * This function returns the number of entries inserted into the tree, 588 * or a negative error code. 589 */ 590 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash, 591 __u32 start_minor_hash, __u32 *next_hash) 592 { 593 struct dx_hash_info hinfo; 594 struct ext4_dir_entry_2 *de; 595 struct dx_frame frames[2], *frame; 596 struct inode *dir; 597 int block, err; 598 int count = 0; 599 int ret; 600 __u32 hashval; 601 602 dxtrace(printk("In htree_fill_tree, start hash: %x:%x\n", start_hash, 603 start_minor_hash)); 604 dir = dir_file->f_path.dentry->d_inode; 605 if (!(EXT4_I(dir)->i_flags & EXT4_INDEX_FL)) { 606 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version; 607 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; 608 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo, 609 start_hash, start_minor_hash); 610 *next_hash = ~0; 611 return count; 612 } 613 hinfo.hash = start_hash; 614 hinfo.minor_hash = 0; 615 frame = dx_probe(NULL, dir_file->f_path.dentry->d_inode, &hinfo, frames, &err); 616 if (!frame) 617 return err; 618 619 /* Add '.' and '..' from the htree header */ 620 if (!start_hash && !start_minor_hash) { 621 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; 622 if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0) 623 goto errout; 624 count++; 625 } 626 if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) { 627 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; 628 de = ext4_next_entry(de); 629 if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0) 630 goto errout; 631 count++; 632 } 633 634 while (1) { 635 block = dx_get_block(frame->at); 636 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo, 637 start_hash, start_minor_hash); 638 if (ret < 0) { 639 err = ret; 640 goto errout; 641 } 642 count += ret; 643 hashval = ~0; 644 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS, 645 frame, frames, &hashval); 646 *next_hash = hashval; 647 if (ret < 0) { 648 err = ret; 649 goto errout; 650 } 651 /* 652 * Stop if: (a) there are no more entries, or 653 * (b) we have inserted at least one entry and the 654 * next hash value is not a continuation 655 */ 656 if ((ret == 0) || 657 (count && ((hashval & 1) == 0))) 658 break; 659 } 660 dx_release(frames); 661 dxtrace(printk("Fill tree: returned %d entries, next hash: %x\n", 662 count, *next_hash)); 663 return count; 664 errout: 665 dx_release(frames); 666 return (err); 667 } 668 669 670 /* 671 * Directory block splitting, compacting 672 */ 673 674 static int dx_make_map (struct ext4_dir_entry_2 *de, int size, 675 struct dx_hash_info *hinfo, struct dx_map_entry *map_tail) 676 { 677 int count = 0; 678 char *base = (char *) de; 679 struct dx_hash_info h = *hinfo; 680 681 while ((char *) de < base + size) 682 { 683 if (de->name_len && de->inode) { 684 ext4fs_dirhash(de->name, de->name_len, &h); 685 map_tail--; 686 map_tail->hash = h.hash; 687 map_tail->offs = (u32) ((char *) de - base); 688 count++; 689 cond_resched(); 690 } 691 /* XXX: do we need to check rec_len == 0 case? -Chris */ 692 de = (struct ext4_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len)); 693 } 694 return count; 695 } 696 697 static void dx_sort_map (struct dx_map_entry *map, unsigned count) 698 { 699 struct dx_map_entry *p, *q, *top = map + count - 1; 700 int more; 701 /* Combsort until bubble sort doesn't suck */ 702 while (count > 2) { 703 count = count*10/13; 704 if (count - 9 < 2) /* 9, 10 -> 11 */ 705 count = 11; 706 for (p = top, q = p - count; q >= map; p--, q--) 707 if (p->hash < q->hash) 708 swap(*p, *q); 709 } 710 /* Garden variety bubble sort */ 711 do { 712 more = 0; 713 q = top; 714 while (q-- > map) { 715 if (q[1].hash >= q[0].hash) 716 continue; 717 swap(*(q+1), *q); 718 more = 1; 719 } 720 } while(more); 721 } 722 723 static void dx_insert_block(struct dx_frame *frame, u32 hash, u32 block) 724 { 725 struct dx_entry *entries = frame->entries; 726 struct dx_entry *old = frame->at, *new = old + 1; 727 int count = dx_get_count(entries); 728 729 assert(count < dx_get_limit(entries)); 730 assert(old < entries + count); 731 memmove(new + 1, new, (char *)(entries + count) - (char *)(new)); 732 dx_set_hash(new, hash); 733 dx_set_block(new, block); 734 dx_set_count(entries, count + 1); 735 } 736 #endif 737 738 739 static void ext4_update_dx_flag(struct inode *inode) 740 { 741 if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb, 742 EXT4_FEATURE_COMPAT_DIR_INDEX)) 743 EXT4_I(inode)->i_flags &= ~EXT4_INDEX_FL; 744 } 745 746 /* 747 * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure. 748 * 749 * `len <= EXT4_NAME_LEN' is guaranteed by caller. 750 * `de != NULL' is guaranteed by caller. 751 */ 752 static inline int ext4_match (int len, const char * const name, 753 struct ext4_dir_entry_2 * de) 754 { 755 if (len != de->name_len) 756 return 0; 757 if (!de->inode) 758 return 0; 759 return !memcmp(name, de->name, len); 760 } 761 762 /* 763 * Returns 0 if not found, -1 on failure, and 1 on success 764 */ 765 static inline int search_dirblock(struct buffer_head * bh, 766 struct inode *dir, 767 struct dentry *dentry, 768 unsigned long offset, 769 struct ext4_dir_entry_2 ** res_dir) 770 { 771 struct ext4_dir_entry_2 * de; 772 char * dlimit; 773 int de_len; 774 const char *name = dentry->d_name.name; 775 int namelen = dentry->d_name.len; 776 777 de = (struct ext4_dir_entry_2 *) bh->b_data; 778 dlimit = bh->b_data + dir->i_sb->s_blocksize; 779 while ((char *) de < dlimit) { 780 /* this code is executed quadratically often */ 781 /* do minimal checking `by hand' */ 782 783 if ((char *) de + namelen <= dlimit && 784 ext4_match (namelen, name, de)) { 785 /* found a match - just to be sure, do a full check */ 786 if (!ext4_check_dir_entry("ext4_find_entry", 787 dir, de, bh, offset)) 788 return -1; 789 *res_dir = de; 790 return 1; 791 } 792 /* prevent looping on a bad block */ 793 de_len = le16_to_cpu(de->rec_len); 794 if (de_len <= 0) 795 return -1; 796 offset += de_len; 797 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len); 798 } 799 return 0; 800 } 801 802 803 /* 804 * ext4_find_entry() 805 * 806 * finds an entry in the specified directory with the wanted name. It 807 * returns the cache buffer in which the entry was found, and the entry 808 * itself (as a parameter - res_dir). It does NOT read the inode of the 809 * entry - you'll have to do that yourself if you want to. 810 * 811 * The returned buffer_head has ->b_count elevated. The caller is expected 812 * to brelse() it when appropriate. 813 */ 814 static struct buffer_head * ext4_find_entry (struct dentry *dentry, 815 struct ext4_dir_entry_2 ** res_dir) 816 { 817 struct super_block * sb; 818 struct buffer_head * bh_use[NAMEI_RA_SIZE]; 819 struct buffer_head * bh, *ret = NULL; 820 unsigned long start, block, b; 821 int ra_max = 0; /* Number of bh's in the readahead 822 buffer, bh_use[] */ 823 int ra_ptr = 0; /* Current index into readahead 824 buffer */ 825 int num = 0; 826 int nblocks, i, err; 827 struct inode *dir = dentry->d_parent->d_inode; 828 int namelen; 829 const u8 *name; 830 unsigned blocksize; 831 832 *res_dir = NULL; 833 sb = dir->i_sb; 834 blocksize = sb->s_blocksize; 835 namelen = dentry->d_name.len; 836 name = dentry->d_name.name; 837 if (namelen > EXT4_NAME_LEN) 838 return NULL; 839 #ifdef CONFIG_EXT4_INDEX 840 if (is_dx(dir)) { 841 bh = ext4_dx_find_entry(dentry, res_dir, &err); 842 /* 843 * On success, or if the error was file not found, 844 * return. Otherwise, fall back to doing a search the 845 * old fashioned way. 846 */ 847 if (bh || (err != ERR_BAD_DX_DIR)) 848 return bh; 849 dxtrace(printk("ext4_find_entry: dx failed, falling back\n")); 850 } 851 #endif 852 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); 853 start = EXT4_I(dir)->i_dir_start_lookup; 854 if (start >= nblocks) 855 start = 0; 856 block = start; 857 restart: 858 do { 859 /* 860 * We deal with the read-ahead logic here. 861 */ 862 if (ra_ptr >= ra_max) { 863 /* Refill the readahead buffer */ 864 ra_ptr = 0; 865 b = block; 866 for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) { 867 /* 868 * Terminate if we reach the end of the 869 * directory and must wrap, or if our 870 * search has finished at this block. 871 */ 872 if (b >= nblocks || (num && block == start)) { 873 bh_use[ra_max] = NULL; 874 break; 875 } 876 num++; 877 bh = ext4_getblk(NULL, dir, b++, 0, &err); 878 bh_use[ra_max] = bh; 879 if (bh) 880 ll_rw_block(READ_META, 1, &bh); 881 } 882 } 883 if ((bh = bh_use[ra_ptr++]) == NULL) 884 goto next; 885 wait_on_buffer(bh); 886 if (!buffer_uptodate(bh)) { 887 /* read error, skip block & hope for the best */ 888 ext4_error(sb, __FUNCTION__, "reading directory #%lu " 889 "offset %lu", dir->i_ino, block); 890 brelse(bh); 891 goto next; 892 } 893 i = search_dirblock(bh, dir, dentry, 894 block << EXT4_BLOCK_SIZE_BITS(sb), res_dir); 895 if (i == 1) { 896 EXT4_I(dir)->i_dir_start_lookup = block; 897 ret = bh; 898 goto cleanup_and_exit; 899 } else { 900 brelse(bh); 901 if (i < 0) 902 goto cleanup_and_exit; 903 } 904 next: 905 if (++block >= nblocks) 906 block = 0; 907 } while (block != start); 908 909 /* 910 * If the directory has grown while we were searching, then 911 * search the last part of the directory before giving up. 912 */ 913 block = nblocks; 914 nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); 915 if (block < nblocks) { 916 start = 0; 917 goto restart; 918 } 919 920 cleanup_and_exit: 921 /* Clean up the read-ahead blocks */ 922 for (; ra_ptr < ra_max; ra_ptr++) 923 brelse (bh_use[ra_ptr]); 924 return ret; 925 } 926 927 #ifdef CONFIG_EXT4_INDEX 928 static struct buffer_head * ext4_dx_find_entry(struct dentry *dentry, 929 struct ext4_dir_entry_2 **res_dir, int *err) 930 { 931 struct super_block * sb; 932 struct dx_hash_info hinfo; 933 u32 hash; 934 struct dx_frame frames[2], *frame; 935 struct ext4_dir_entry_2 *de, *top; 936 struct buffer_head *bh; 937 unsigned long block; 938 int retval; 939 int namelen = dentry->d_name.len; 940 const u8 *name = dentry->d_name.name; 941 struct inode *dir = dentry->d_parent->d_inode; 942 943 sb = dir->i_sb; 944 /* NFS may look up ".." - look at dx_root directory block */ 945 if (namelen > 2 || name[0] != '.'||(name[1] != '.' && name[1] != '\0')){ 946 if (!(frame = dx_probe(dentry, NULL, &hinfo, frames, err))) 947 return NULL; 948 } else { 949 frame = frames; 950 frame->bh = NULL; /* for dx_release() */ 951 frame->at = (struct dx_entry *)frames; /* hack for zero entry*/ 952 dx_set_block(frame->at, 0); /* dx_root block is 0 */ 953 } 954 hash = hinfo.hash; 955 do { 956 block = dx_get_block(frame->at); 957 if (!(bh = ext4_bread (NULL,dir, block, 0, err))) 958 goto errout; 959 de = (struct ext4_dir_entry_2 *) bh->b_data; 960 top = (struct ext4_dir_entry_2 *) ((char *) de + sb->s_blocksize - 961 EXT4_DIR_REC_LEN(0)); 962 for (; de < top; de = ext4_next_entry(de)) 963 if (ext4_match (namelen, name, de)) { 964 if (!ext4_check_dir_entry("ext4_find_entry", 965 dir, de, bh, 966 (block<<EXT4_BLOCK_SIZE_BITS(sb)) 967 +((char *)de - bh->b_data))) { 968 brelse (bh); 969 *err = ERR_BAD_DX_DIR; 970 goto errout; 971 } 972 *res_dir = de; 973 dx_release (frames); 974 return bh; 975 } 976 brelse (bh); 977 /* Check to see if we should continue to search */ 978 retval = ext4_htree_next_block(dir, hash, frame, 979 frames, NULL); 980 if (retval < 0) { 981 ext4_warning(sb, __FUNCTION__, 982 "error reading index page in directory #%lu", 983 dir->i_ino); 984 *err = retval; 985 goto errout; 986 } 987 } while (retval == 1); 988 989 *err = -ENOENT; 990 errout: 991 dxtrace(printk("%s not found\n", name)); 992 dx_release (frames); 993 return NULL; 994 } 995 #endif 996 997 static struct dentry *ext4_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd) 998 { 999 struct inode * inode; 1000 struct ext4_dir_entry_2 * de; 1001 struct buffer_head * bh; 1002 1003 if (dentry->d_name.len > EXT4_NAME_LEN) 1004 return ERR_PTR(-ENAMETOOLONG); 1005 1006 bh = ext4_find_entry(dentry, &de); 1007 inode = NULL; 1008 if (bh) { 1009 unsigned long ino = le32_to_cpu(de->inode); 1010 brelse (bh); 1011 if (!ext4_valid_inum(dir->i_sb, ino)) { 1012 ext4_error(dir->i_sb, "ext4_lookup", 1013 "bad inode number: %lu", ino); 1014 inode = NULL; 1015 } else 1016 inode = iget(dir->i_sb, ino); 1017 1018 if (!inode) 1019 return ERR_PTR(-EACCES); 1020 1021 if (is_bad_inode(inode)) { 1022 iput(inode); 1023 return ERR_PTR(-ENOENT); 1024 } 1025 } 1026 return d_splice_alias(inode, dentry); 1027 } 1028 1029 1030 struct dentry *ext4_get_parent(struct dentry *child) 1031 { 1032 unsigned long ino; 1033 struct dentry *parent; 1034 struct inode *inode; 1035 struct dentry dotdot; 1036 struct ext4_dir_entry_2 * de; 1037 struct buffer_head *bh; 1038 1039 dotdot.d_name.name = ".."; 1040 dotdot.d_name.len = 2; 1041 dotdot.d_parent = child; /* confusing, isn't it! */ 1042 1043 bh = ext4_find_entry(&dotdot, &de); 1044 inode = NULL; 1045 if (!bh) 1046 return ERR_PTR(-ENOENT); 1047 ino = le32_to_cpu(de->inode); 1048 brelse(bh); 1049 1050 if (!ext4_valid_inum(child->d_inode->i_sb, ino)) { 1051 ext4_error(child->d_inode->i_sb, "ext4_get_parent", 1052 "bad inode number: %lu", ino); 1053 inode = NULL; 1054 } else 1055 inode = iget(child->d_inode->i_sb, ino); 1056 1057 if (!inode) 1058 return ERR_PTR(-EACCES); 1059 1060 if (is_bad_inode(inode)) { 1061 iput(inode); 1062 return ERR_PTR(-ENOENT); 1063 } 1064 1065 parent = d_alloc_anon(inode); 1066 if (!parent) { 1067 iput(inode); 1068 parent = ERR_PTR(-ENOMEM); 1069 } 1070 return parent; 1071 } 1072 1073 #define S_SHIFT 12 1074 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = { 1075 [S_IFREG >> S_SHIFT] = EXT4_FT_REG_FILE, 1076 [S_IFDIR >> S_SHIFT] = EXT4_FT_DIR, 1077 [S_IFCHR >> S_SHIFT] = EXT4_FT_CHRDEV, 1078 [S_IFBLK >> S_SHIFT] = EXT4_FT_BLKDEV, 1079 [S_IFIFO >> S_SHIFT] = EXT4_FT_FIFO, 1080 [S_IFSOCK >> S_SHIFT] = EXT4_FT_SOCK, 1081 [S_IFLNK >> S_SHIFT] = EXT4_FT_SYMLINK, 1082 }; 1083 1084 static inline void ext4_set_de_type(struct super_block *sb, 1085 struct ext4_dir_entry_2 *de, 1086 umode_t mode) { 1087 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE)) 1088 de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT]; 1089 } 1090 1091 #ifdef CONFIG_EXT4_INDEX 1092 static struct ext4_dir_entry_2 * 1093 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count) 1094 { 1095 unsigned rec_len = 0; 1096 1097 while (count--) { 1098 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) (from + map->offs); 1099 rec_len = EXT4_DIR_REC_LEN(de->name_len); 1100 memcpy (to, de, rec_len); 1101 ((struct ext4_dir_entry_2 *) to)->rec_len = 1102 cpu_to_le16(rec_len); 1103 de->inode = 0; 1104 map++; 1105 to += rec_len; 1106 } 1107 return (struct ext4_dir_entry_2 *) (to - rec_len); 1108 } 1109 1110 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, int size) 1111 { 1112 struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base; 1113 unsigned rec_len = 0; 1114 1115 prev = to = de; 1116 while ((char*)de < base + size) { 1117 next = (struct ext4_dir_entry_2 *) ((char *) de + 1118 le16_to_cpu(de->rec_len)); 1119 if (de->inode && de->name_len) { 1120 rec_len = EXT4_DIR_REC_LEN(de->name_len); 1121 if (de > to) 1122 memmove(to, de, rec_len); 1123 to->rec_len = cpu_to_le16(rec_len); 1124 prev = to; 1125 to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len); 1126 } 1127 de = next; 1128 } 1129 return prev; 1130 } 1131 1132 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir, 1133 struct buffer_head **bh,struct dx_frame *frame, 1134 struct dx_hash_info *hinfo, int *error) 1135 { 1136 unsigned blocksize = dir->i_sb->s_blocksize; 1137 unsigned count, continued; 1138 struct buffer_head *bh2; 1139 u32 newblock; 1140 u32 hash2; 1141 struct dx_map_entry *map; 1142 char *data1 = (*bh)->b_data, *data2; 1143 unsigned split; 1144 struct ext4_dir_entry_2 *de = NULL, *de2; 1145 int err = 0; 1146 1147 bh2 = ext4_append (handle, dir, &newblock, &err); 1148 if (!(bh2)) { 1149 brelse(*bh); 1150 *bh = NULL; 1151 goto errout; 1152 } 1153 1154 BUFFER_TRACE(*bh, "get_write_access"); 1155 err = ext4_journal_get_write_access(handle, *bh); 1156 if (err) 1157 goto journal_error; 1158 1159 BUFFER_TRACE(frame->bh, "get_write_access"); 1160 err = ext4_journal_get_write_access(handle, frame->bh); 1161 if (err) 1162 goto journal_error; 1163 1164 data2 = bh2->b_data; 1165 1166 /* create map in the end of data2 block */ 1167 map = (struct dx_map_entry *) (data2 + blocksize); 1168 count = dx_make_map ((struct ext4_dir_entry_2 *) data1, 1169 blocksize, hinfo, map); 1170 map -= count; 1171 split = count/2; // need to adjust to actual middle 1172 dx_sort_map (map, count); 1173 hash2 = map[split].hash; 1174 continued = hash2 == map[split - 1].hash; 1175 dxtrace(printk("Split block %i at %x, %i/%i\n", 1176 dx_get_block(frame->at), hash2, split, count-split)); 1177 1178 /* Fancy dance to stay within two buffers */ 1179 de2 = dx_move_dirents(data1, data2, map + split, count - split); 1180 de = dx_pack_dirents(data1,blocksize); 1181 de->rec_len = cpu_to_le16(data1 + blocksize - (char *) de); 1182 de2->rec_len = cpu_to_le16(data2 + blocksize - (char *) de2); 1183 dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1)); 1184 dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1)); 1185 1186 /* Which block gets the new entry? */ 1187 if (hinfo->hash >= hash2) 1188 { 1189 swap(*bh, bh2); 1190 de = de2; 1191 } 1192 dx_insert_block (frame, hash2 + continued, newblock); 1193 err = ext4_journal_dirty_metadata (handle, bh2); 1194 if (err) 1195 goto journal_error; 1196 err = ext4_journal_dirty_metadata (handle, frame->bh); 1197 if (err) 1198 goto journal_error; 1199 brelse (bh2); 1200 dxtrace(dx_show_index ("frame", frame->entries)); 1201 return de; 1202 1203 journal_error: 1204 brelse(*bh); 1205 brelse(bh2); 1206 *bh = NULL; 1207 ext4_std_error(dir->i_sb, err); 1208 errout: 1209 *error = err; 1210 return NULL; 1211 } 1212 #endif 1213 1214 1215 /* 1216 * Add a new entry into a directory (leaf) block. If de is non-NULL, 1217 * it points to a directory entry which is guaranteed to be large 1218 * enough for new directory entry. If de is NULL, then 1219 * add_dirent_to_buf will attempt search the directory block for 1220 * space. It will return -ENOSPC if no space is available, and -EIO 1221 * and -EEXIST if directory entry already exists. 1222 * 1223 * NOTE! bh is NOT released in the case where ENOSPC is returned. In 1224 * all other cases bh is released. 1225 */ 1226 static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry, 1227 struct inode *inode, struct ext4_dir_entry_2 *de, 1228 struct buffer_head * bh) 1229 { 1230 struct inode *dir = dentry->d_parent->d_inode; 1231 const char *name = dentry->d_name.name; 1232 int namelen = dentry->d_name.len; 1233 unsigned long offset = 0; 1234 unsigned short reclen; 1235 int nlen, rlen, err; 1236 char *top; 1237 1238 reclen = EXT4_DIR_REC_LEN(namelen); 1239 if (!de) { 1240 de = (struct ext4_dir_entry_2 *)bh->b_data; 1241 top = bh->b_data + dir->i_sb->s_blocksize - reclen; 1242 while ((char *) de <= top) { 1243 if (!ext4_check_dir_entry("ext4_add_entry", dir, de, 1244 bh, offset)) { 1245 brelse (bh); 1246 return -EIO; 1247 } 1248 if (ext4_match (namelen, name, de)) { 1249 brelse (bh); 1250 return -EEXIST; 1251 } 1252 nlen = EXT4_DIR_REC_LEN(de->name_len); 1253 rlen = le16_to_cpu(de->rec_len); 1254 if ((de->inode? rlen - nlen: rlen) >= reclen) 1255 break; 1256 de = (struct ext4_dir_entry_2 *)((char *)de + rlen); 1257 offset += rlen; 1258 } 1259 if ((char *) de > top) 1260 return -ENOSPC; 1261 } 1262 BUFFER_TRACE(bh, "get_write_access"); 1263 err = ext4_journal_get_write_access(handle, bh); 1264 if (err) { 1265 ext4_std_error(dir->i_sb, err); 1266 brelse(bh); 1267 return err; 1268 } 1269 1270 /* By now the buffer is marked for journaling */ 1271 nlen = EXT4_DIR_REC_LEN(de->name_len); 1272 rlen = le16_to_cpu(de->rec_len); 1273 if (de->inode) { 1274 struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen); 1275 de1->rec_len = cpu_to_le16(rlen - nlen); 1276 de->rec_len = cpu_to_le16(nlen); 1277 de = de1; 1278 } 1279 de->file_type = EXT4_FT_UNKNOWN; 1280 if (inode) { 1281 de->inode = cpu_to_le32(inode->i_ino); 1282 ext4_set_de_type(dir->i_sb, de, inode->i_mode); 1283 } else 1284 de->inode = 0; 1285 de->name_len = namelen; 1286 memcpy (de->name, name, namelen); 1287 /* 1288 * XXX shouldn't update any times until successful 1289 * completion of syscall, but too many callers depend 1290 * on this. 1291 * 1292 * XXX similarly, too many callers depend on 1293 * ext4_new_inode() setting the times, but error 1294 * recovery deletes the inode, so the worst that can 1295 * happen is that the times are slightly out of date 1296 * and/or different from the directory change time. 1297 */ 1298 dir->i_mtime = dir->i_ctime = ext4_current_time(dir); 1299 ext4_update_dx_flag(dir); 1300 dir->i_version++; 1301 ext4_mark_inode_dirty(handle, dir); 1302 BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata"); 1303 err = ext4_journal_dirty_metadata(handle, bh); 1304 if (err) 1305 ext4_std_error(dir->i_sb, err); 1306 brelse(bh); 1307 return 0; 1308 } 1309 1310 #ifdef CONFIG_EXT4_INDEX 1311 /* 1312 * This converts a one block unindexed directory to a 3 block indexed 1313 * directory, and adds the dentry to the indexed directory. 1314 */ 1315 static int make_indexed_dir(handle_t *handle, struct dentry *dentry, 1316 struct inode *inode, struct buffer_head *bh) 1317 { 1318 struct inode *dir = dentry->d_parent->d_inode; 1319 const char *name = dentry->d_name.name; 1320 int namelen = dentry->d_name.len; 1321 struct buffer_head *bh2; 1322 struct dx_root *root; 1323 struct dx_frame frames[2], *frame; 1324 struct dx_entry *entries; 1325 struct ext4_dir_entry_2 *de, *de2; 1326 char *data1, *top; 1327 unsigned len; 1328 int retval; 1329 unsigned blocksize; 1330 struct dx_hash_info hinfo; 1331 u32 block; 1332 struct fake_dirent *fde; 1333 1334 blocksize = dir->i_sb->s_blocksize; 1335 dxtrace(printk("Creating index\n")); 1336 retval = ext4_journal_get_write_access(handle, bh); 1337 if (retval) { 1338 ext4_std_error(dir->i_sb, retval); 1339 brelse(bh); 1340 return retval; 1341 } 1342 root = (struct dx_root *) bh->b_data; 1343 1344 bh2 = ext4_append (handle, dir, &block, &retval); 1345 if (!(bh2)) { 1346 brelse(bh); 1347 return retval; 1348 } 1349 EXT4_I(dir)->i_flags |= EXT4_INDEX_FL; 1350 data1 = bh2->b_data; 1351 1352 /* The 0th block becomes the root, move the dirents out */ 1353 fde = &root->dotdot; 1354 de = (struct ext4_dir_entry_2 *)((char *)fde + le16_to_cpu(fde->rec_len)); 1355 len = ((char *) root) + blocksize - (char *) de; 1356 memcpy (data1, de, len); 1357 de = (struct ext4_dir_entry_2 *) data1; 1358 top = data1 + len; 1359 while ((char *)(de2=(void*)de+le16_to_cpu(de->rec_len)) < top) 1360 de = de2; 1361 de->rec_len = cpu_to_le16(data1 + blocksize - (char *) de); 1362 /* Initialize the root; the dot dirents already exist */ 1363 de = (struct ext4_dir_entry_2 *) (&root->dotdot); 1364 de->rec_len = cpu_to_le16(blocksize - EXT4_DIR_REC_LEN(2)); 1365 memset (&root->info, 0, sizeof(root->info)); 1366 root->info.info_length = sizeof(root->info); 1367 root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version; 1368 entries = root->entries; 1369 dx_set_block (entries, 1); 1370 dx_set_count (entries, 1); 1371 dx_set_limit (entries, dx_root_limit(dir, sizeof(root->info))); 1372 1373 /* Initialize as for dx_probe */ 1374 hinfo.hash_version = root->info.hash_version; 1375 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; 1376 ext4fs_dirhash(name, namelen, &hinfo); 1377 frame = frames; 1378 frame->entries = entries; 1379 frame->at = entries; 1380 frame->bh = bh; 1381 bh = bh2; 1382 de = do_split(handle,dir, &bh, frame, &hinfo, &retval); 1383 dx_release (frames); 1384 if (!(de)) 1385 return retval; 1386 1387 return add_dirent_to_buf(handle, dentry, inode, de, bh); 1388 } 1389 #endif 1390 1391 /* 1392 * ext4_add_entry() 1393 * 1394 * adds a file entry to the specified directory, using the same 1395 * semantics as ext4_find_entry(). It returns NULL if it failed. 1396 * 1397 * NOTE!! The inode part of 'de' is left at 0 - which means you 1398 * may not sleep between calling this and putting something into 1399 * the entry, as someone else might have used it while you slept. 1400 */ 1401 static int ext4_add_entry (handle_t *handle, struct dentry *dentry, 1402 struct inode *inode) 1403 { 1404 struct inode *dir = dentry->d_parent->d_inode; 1405 unsigned long offset; 1406 struct buffer_head * bh; 1407 struct ext4_dir_entry_2 *de; 1408 struct super_block * sb; 1409 int retval; 1410 #ifdef CONFIG_EXT4_INDEX 1411 int dx_fallback=0; 1412 #endif 1413 unsigned blocksize; 1414 u32 block, blocks; 1415 1416 sb = dir->i_sb; 1417 blocksize = sb->s_blocksize; 1418 if (!dentry->d_name.len) 1419 return -EINVAL; 1420 #ifdef CONFIG_EXT4_INDEX 1421 if (is_dx(dir)) { 1422 retval = ext4_dx_add_entry(handle, dentry, inode); 1423 if (!retval || (retval != ERR_BAD_DX_DIR)) 1424 return retval; 1425 EXT4_I(dir)->i_flags &= ~EXT4_INDEX_FL; 1426 dx_fallback++; 1427 ext4_mark_inode_dirty(handle, dir); 1428 } 1429 #endif 1430 blocks = dir->i_size >> sb->s_blocksize_bits; 1431 for (block = 0, offset = 0; block < blocks; block++) { 1432 bh = ext4_bread(handle, dir, block, 0, &retval); 1433 if(!bh) 1434 return retval; 1435 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh); 1436 if (retval != -ENOSPC) 1437 return retval; 1438 1439 #ifdef CONFIG_EXT4_INDEX 1440 if (blocks == 1 && !dx_fallback && 1441 EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) 1442 return make_indexed_dir(handle, dentry, inode, bh); 1443 #endif 1444 brelse(bh); 1445 } 1446 bh = ext4_append(handle, dir, &block, &retval); 1447 if (!bh) 1448 return retval; 1449 de = (struct ext4_dir_entry_2 *) bh->b_data; 1450 de->inode = 0; 1451 de->rec_len = cpu_to_le16(blocksize); 1452 return add_dirent_to_buf(handle, dentry, inode, de, bh); 1453 } 1454 1455 #ifdef CONFIG_EXT4_INDEX 1456 /* 1457 * Returns 0 for success, or a negative error value 1458 */ 1459 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry, 1460 struct inode *inode) 1461 { 1462 struct dx_frame frames[2], *frame; 1463 struct dx_entry *entries, *at; 1464 struct dx_hash_info hinfo; 1465 struct buffer_head * bh; 1466 struct inode *dir = dentry->d_parent->d_inode; 1467 struct super_block * sb = dir->i_sb; 1468 struct ext4_dir_entry_2 *de; 1469 int err; 1470 1471 frame = dx_probe(dentry, NULL, &hinfo, frames, &err); 1472 if (!frame) 1473 return err; 1474 entries = frame->entries; 1475 at = frame->at; 1476 1477 if (!(bh = ext4_bread(handle,dir, dx_get_block(frame->at), 0, &err))) 1478 goto cleanup; 1479 1480 BUFFER_TRACE(bh, "get_write_access"); 1481 err = ext4_journal_get_write_access(handle, bh); 1482 if (err) 1483 goto journal_error; 1484 1485 err = add_dirent_to_buf(handle, dentry, inode, NULL, bh); 1486 if (err != -ENOSPC) { 1487 bh = NULL; 1488 goto cleanup; 1489 } 1490 1491 /* Block full, should compress but for now just split */ 1492 dxtrace(printk("using %u of %u node entries\n", 1493 dx_get_count(entries), dx_get_limit(entries))); 1494 /* Need to split index? */ 1495 if (dx_get_count(entries) == dx_get_limit(entries)) { 1496 u32 newblock; 1497 unsigned icount = dx_get_count(entries); 1498 int levels = frame - frames; 1499 struct dx_entry *entries2; 1500 struct dx_node *node2; 1501 struct buffer_head *bh2; 1502 1503 if (levels && (dx_get_count(frames->entries) == 1504 dx_get_limit(frames->entries))) { 1505 ext4_warning(sb, __FUNCTION__, 1506 "Directory index full!"); 1507 err = -ENOSPC; 1508 goto cleanup; 1509 } 1510 bh2 = ext4_append (handle, dir, &newblock, &err); 1511 if (!(bh2)) 1512 goto cleanup; 1513 node2 = (struct dx_node *)(bh2->b_data); 1514 entries2 = node2->entries; 1515 node2->fake.rec_len = cpu_to_le16(sb->s_blocksize); 1516 node2->fake.inode = 0; 1517 BUFFER_TRACE(frame->bh, "get_write_access"); 1518 err = ext4_journal_get_write_access(handle, frame->bh); 1519 if (err) 1520 goto journal_error; 1521 if (levels) { 1522 unsigned icount1 = icount/2, icount2 = icount - icount1; 1523 unsigned hash2 = dx_get_hash(entries + icount1); 1524 dxtrace(printk("Split index %i/%i\n", icount1, icount2)); 1525 1526 BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */ 1527 err = ext4_journal_get_write_access(handle, 1528 frames[0].bh); 1529 if (err) 1530 goto journal_error; 1531 1532 memcpy ((char *) entries2, (char *) (entries + icount1), 1533 icount2 * sizeof(struct dx_entry)); 1534 dx_set_count (entries, icount1); 1535 dx_set_count (entries2, icount2); 1536 dx_set_limit (entries2, dx_node_limit(dir)); 1537 1538 /* Which index block gets the new entry? */ 1539 if (at - entries >= icount1) { 1540 frame->at = at = at - entries - icount1 + entries2; 1541 frame->entries = entries = entries2; 1542 swap(frame->bh, bh2); 1543 } 1544 dx_insert_block (frames + 0, hash2, newblock); 1545 dxtrace(dx_show_index ("node", frames[1].entries)); 1546 dxtrace(dx_show_index ("node", 1547 ((struct dx_node *) bh2->b_data)->entries)); 1548 err = ext4_journal_dirty_metadata(handle, bh2); 1549 if (err) 1550 goto journal_error; 1551 brelse (bh2); 1552 } else { 1553 dxtrace(printk("Creating second level index...\n")); 1554 memcpy((char *) entries2, (char *) entries, 1555 icount * sizeof(struct dx_entry)); 1556 dx_set_limit(entries2, dx_node_limit(dir)); 1557 1558 /* Set up root */ 1559 dx_set_count(entries, 1); 1560 dx_set_block(entries + 0, newblock); 1561 ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1; 1562 1563 /* Add new access path frame */ 1564 frame = frames + 1; 1565 frame->at = at = at - entries + entries2; 1566 frame->entries = entries = entries2; 1567 frame->bh = bh2; 1568 err = ext4_journal_get_write_access(handle, 1569 frame->bh); 1570 if (err) 1571 goto journal_error; 1572 } 1573 ext4_journal_dirty_metadata(handle, frames[0].bh); 1574 } 1575 de = do_split(handle, dir, &bh, frame, &hinfo, &err); 1576 if (!de) 1577 goto cleanup; 1578 err = add_dirent_to_buf(handle, dentry, inode, de, bh); 1579 bh = NULL; 1580 goto cleanup; 1581 1582 journal_error: 1583 ext4_std_error(dir->i_sb, err); 1584 cleanup: 1585 if (bh) 1586 brelse(bh); 1587 dx_release(frames); 1588 return err; 1589 } 1590 #endif 1591 1592 /* 1593 * ext4_delete_entry deletes a directory entry by merging it with the 1594 * previous entry 1595 */ 1596 static int ext4_delete_entry (handle_t *handle, 1597 struct inode * dir, 1598 struct ext4_dir_entry_2 * de_del, 1599 struct buffer_head * bh) 1600 { 1601 struct ext4_dir_entry_2 * de, * pde; 1602 int i; 1603 1604 i = 0; 1605 pde = NULL; 1606 de = (struct ext4_dir_entry_2 *) bh->b_data; 1607 while (i < bh->b_size) { 1608 if (!ext4_check_dir_entry("ext4_delete_entry", dir, de, bh, i)) 1609 return -EIO; 1610 if (de == de_del) { 1611 BUFFER_TRACE(bh, "get_write_access"); 1612 ext4_journal_get_write_access(handle, bh); 1613 if (pde) 1614 pde->rec_len = 1615 cpu_to_le16(le16_to_cpu(pde->rec_len) + 1616 le16_to_cpu(de->rec_len)); 1617 else 1618 de->inode = 0; 1619 dir->i_version++; 1620 BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata"); 1621 ext4_journal_dirty_metadata(handle, bh); 1622 return 0; 1623 } 1624 i += le16_to_cpu(de->rec_len); 1625 pde = de; 1626 de = (struct ext4_dir_entry_2 *) 1627 ((char *) de + le16_to_cpu(de->rec_len)); 1628 } 1629 return -ENOENT; 1630 } 1631 1632 /* 1633 * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2, 1634 * since this indicates that nlinks count was previously 1. 1635 */ 1636 static void ext4_inc_count(handle_t *handle, struct inode *inode) 1637 { 1638 inc_nlink(inode); 1639 if (is_dx(inode) && inode->i_nlink > 1) { 1640 /* limit is 16-bit i_links_count */ 1641 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) { 1642 inode->i_nlink = 1; 1643 EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb, 1644 EXT4_FEATURE_RO_COMPAT_DIR_NLINK); 1645 } 1646 } 1647 } 1648 1649 /* 1650 * If a directory had nlink == 1, then we should let it be 1. This indicates 1651 * directory has >EXT4_LINK_MAX subdirs. 1652 */ 1653 static void ext4_dec_count(handle_t *handle, struct inode *inode) 1654 { 1655 drop_nlink(inode); 1656 if (S_ISDIR(inode->i_mode) && inode->i_nlink == 0) 1657 inc_nlink(inode); 1658 } 1659 1660 1661 static int ext4_add_nondir(handle_t *handle, 1662 struct dentry *dentry, struct inode *inode) 1663 { 1664 int err = ext4_add_entry(handle, dentry, inode); 1665 if (!err) { 1666 ext4_mark_inode_dirty(handle, inode); 1667 d_instantiate(dentry, inode); 1668 return 0; 1669 } 1670 drop_nlink(inode); 1671 iput(inode); 1672 return err; 1673 } 1674 1675 /* 1676 * By the time this is called, we already have created 1677 * the directory cache entry for the new file, but it 1678 * is so far negative - it has no inode. 1679 * 1680 * If the create succeeds, we fill in the inode information 1681 * with d_instantiate(). 1682 */ 1683 static int ext4_create (struct inode * dir, struct dentry * dentry, int mode, 1684 struct nameidata *nd) 1685 { 1686 handle_t *handle; 1687 struct inode * inode; 1688 int err, retries = 0; 1689 1690 retry: 1691 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 1692 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 + 1693 2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb)); 1694 if (IS_ERR(handle)) 1695 return PTR_ERR(handle); 1696 1697 if (IS_DIRSYNC(dir)) 1698 handle->h_sync = 1; 1699 1700 inode = ext4_new_inode (handle, dir, mode); 1701 err = PTR_ERR(inode); 1702 if (!IS_ERR(inode)) { 1703 inode->i_op = &ext4_file_inode_operations; 1704 inode->i_fop = &ext4_file_operations; 1705 ext4_set_aops(inode); 1706 err = ext4_add_nondir(handle, dentry, inode); 1707 } 1708 ext4_journal_stop(handle); 1709 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 1710 goto retry; 1711 return err; 1712 } 1713 1714 static int ext4_mknod (struct inode * dir, struct dentry *dentry, 1715 int mode, dev_t rdev) 1716 { 1717 handle_t *handle; 1718 struct inode *inode; 1719 int err, retries = 0; 1720 1721 if (!new_valid_dev(rdev)) 1722 return -EINVAL; 1723 1724 retry: 1725 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 1726 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 + 1727 2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb)); 1728 if (IS_ERR(handle)) 1729 return PTR_ERR(handle); 1730 1731 if (IS_DIRSYNC(dir)) 1732 handle->h_sync = 1; 1733 1734 inode = ext4_new_inode (handle, dir, mode); 1735 err = PTR_ERR(inode); 1736 if (!IS_ERR(inode)) { 1737 init_special_inode(inode, inode->i_mode, rdev); 1738 #ifdef CONFIG_EXT4DEV_FS_XATTR 1739 inode->i_op = &ext4_special_inode_operations; 1740 #endif 1741 err = ext4_add_nondir(handle, dentry, inode); 1742 } 1743 ext4_journal_stop(handle); 1744 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 1745 goto retry; 1746 return err; 1747 } 1748 1749 static int ext4_mkdir(struct inode * dir, struct dentry * dentry, int mode) 1750 { 1751 handle_t *handle; 1752 struct inode * inode; 1753 struct buffer_head * dir_block; 1754 struct ext4_dir_entry_2 * de; 1755 int err, retries = 0; 1756 1757 if (EXT4_DIR_LINK_MAX(dir)) 1758 return -EMLINK; 1759 1760 retry: 1761 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 1762 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 + 1763 2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb)); 1764 if (IS_ERR(handle)) 1765 return PTR_ERR(handle); 1766 1767 if (IS_DIRSYNC(dir)) 1768 handle->h_sync = 1; 1769 1770 inode = ext4_new_inode (handle, dir, S_IFDIR | mode); 1771 err = PTR_ERR(inode); 1772 if (IS_ERR(inode)) 1773 goto out_stop; 1774 1775 inode->i_op = &ext4_dir_inode_operations; 1776 inode->i_fop = &ext4_dir_operations; 1777 inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize; 1778 dir_block = ext4_bread (handle, inode, 0, 1, &err); 1779 if (!dir_block) { 1780 ext4_dec_count(handle, inode); /* is this nlink == 0? */ 1781 ext4_mark_inode_dirty(handle, inode); 1782 iput (inode); 1783 goto out_stop; 1784 } 1785 BUFFER_TRACE(dir_block, "get_write_access"); 1786 ext4_journal_get_write_access(handle, dir_block); 1787 de = (struct ext4_dir_entry_2 *) dir_block->b_data; 1788 de->inode = cpu_to_le32(inode->i_ino); 1789 de->name_len = 1; 1790 de->rec_len = cpu_to_le16(EXT4_DIR_REC_LEN(de->name_len)); 1791 strcpy (de->name, "."); 1792 ext4_set_de_type(dir->i_sb, de, S_IFDIR); 1793 de = (struct ext4_dir_entry_2 *) 1794 ((char *) de + le16_to_cpu(de->rec_len)); 1795 de->inode = cpu_to_le32(dir->i_ino); 1796 de->rec_len = cpu_to_le16(inode->i_sb->s_blocksize-EXT4_DIR_REC_LEN(1)); 1797 de->name_len = 2; 1798 strcpy (de->name, ".."); 1799 ext4_set_de_type(dir->i_sb, de, S_IFDIR); 1800 inode->i_nlink = 2; 1801 BUFFER_TRACE(dir_block, "call ext4_journal_dirty_metadata"); 1802 ext4_journal_dirty_metadata(handle, dir_block); 1803 brelse (dir_block); 1804 ext4_mark_inode_dirty(handle, inode); 1805 err = ext4_add_entry (handle, dentry, inode); 1806 if (err) { 1807 inode->i_nlink = 0; 1808 ext4_mark_inode_dirty(handle, inode); 1809 iput (inode); 1810 goto out_stop; 1811 } 1812 ext4_inc_count(handle, dir); 1813 ext4_update_dx_flag(dir); 1814 ext4_mark_inode_dirty(handle, dir); 1815 d_instantiate(dentry, inode); 1816 out_stop: 1817 ext4_journal_stop(handle); 1818 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 1819 goto retry; 1820 return err; 1821 } 1822 1823 /* 1824 * routine to check that the specified directory is empty (for rmdir) 1825 */ 1826 static int empty_dir (struct inode * inode) 1827 { 1828 unsigned long offset; 1829 struct buffer_head * bh; 1830 struct ext4_dir_entry_2 * de, * de1; 1831 struct super_block * sb; 1832 int err = 0; 1833 1834 sb = inode->i_sb; 1835 if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) || 1836 !(bh = ext4_bread (NULL, inode, 0, 0, &err))) { 1837 if (err) 1838 ext4_error(inode->i_sb, __FUNCTION__, 1839 "error %d reading directory #%lu offset 0", 1840 err, inode->i_ino); 1841 else 1842 ext4_warning(inode->i_sb, __FUNCTION__, 1843 "bad directory (dir #%lu) - no data block", 1844 inode->i_ino); 1845 return 1; 1846 } 1847 de = (struct ext4_dir_entry_2 *) bh->b_data; 1848 de1 = (struct ext4_dir_entry_2 *) 1849 ((char *) de + le16_to_cpu(de->rec_len)); 1850 if (le32_to_cpu(de->inode) != inode->i_ino || 1851 !le32_to_cpu(de1->inode) || 1852 strcmp (".", de->name) || 1853 strcmp ("..", de1->name)) { 1854 ext4_warning (inode->i_sb, "empty_dir", 1855 "bad directory (dir #%lu) - no `.' or `..'", 1856 inode->i_ino); 1857 brelse (bh); 1858 return 1; 1859 } 1860 offset = le16_to_cpu(de->rec_len) + le16_to_cpu(de1->rec_len); 1861 de = (struct ext4_dir_entry_2 *) 1862 ((char *) de1 + le16_to_cpu(de1->rec_len)); 1863 while (offset < inode->i_size ) { 1864 if (!bh || 1865 (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) { 1866 err = 0; 1867 brelse (bh); 1868 bh = ext4_bread (NULL, inode, 1869 offset >> EXT4_BLOCK_SIZE_BITS(sb), 0, &err); 1870 if (!bh) { 1871 if (err) 1872 ext4_error(sb, __FUNCTION__, 1873 "error %d reading directory" 1874 " #%lu offset %lu", 1875 err, inode->i_ino, offset); 1876 offset += sb->s_blocksize; 1877 continue; 1878 } 1879 de = (struct ext4_dir_entry_2 *) bh->b_data; 1880 } 1881 if (!ext4_check_dir_entry("empty_dir", inode, de, bh, offset)) { 1882 de = (struct ext4_dir_entry_2 *)(bh->b_data + 1883 sb->s_blocksize); 1884 offset = (offset | (sb->s_blocksize - 1)) + 1; 1885 continue; 1886 } 1887 if (le32_to_cpu(de->inode)) { 1888 brelse (bh); 1889 return 0; 1890 } 1891 offset += le16_to_cpu(de->rec_len); 1892 de = (struct ext4_dir_entry_2 *) 1893 ((char *) de + le16_to_cpu(de->rec_len)); 1894 } 1895 brelse (bh); 1896 return 1; 1897 } 1898 1899 /* ext4_orphan_add() links an unlinked or truncated inode into a list of 1900 * such inodes, starting at the superblock, in case we crash before the 1901 * file is closed/deleted, or in case the inode truncate spans multiple 1902 * transactions and the last transaction is not recovered after a crash. 1903 * 1904 * At filesystem recovery time, we walk this list deleting unlinked 1905 * inodes and truncating linked inodes in ext4_orphan_cleanup(). 1906 */ 1907 int ext4_orphan_add(handle_t *handle, struct inode *inode) 1908 { 1909 struct super_block *sb = inode->i_sb; 1910 struct ext4_iloc iloc; 1911 int err = 0, rc; 1912 1913 lock_super(sb); 1914 if (!list_empty(&EXT4_I(inode)->i_orphan)) 1915 goto out_unlock; 1916 1917 /* Orphan handling is only valid for files with data blocks 1918 * being truncated, or files being unlinked. */ 1919 1920 /* @@@ FIXME: Observation from aviro: 1921 * I think I can trigger J_ASSERT in ext4_orphan_add(). We block 1922 * here (on lock_super()), so race with ext4_link() which might bump 1923 * ->i_nlink. For, say it, character device. Not a regular file, 1924 * not a directory, not a symlink and ->i_nlink > 0. 1925 */ 1926 J_ASSERT ((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1927 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0); 1928 1929 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access"); 1930 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh); 1931 if (err) 1932 goto out_unlock; 1933 1934 err = ext4_reserve_inode_write(handle, inode, &iloc); 1935 if (err) 1936 goto out_unlock; 1937 1938 /* Insert this inode at the head of the on-disk orphan list... */ 1939 NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan); 1940 EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino); 1941 err = ext4_journal_dirty_metadata(handle, EXT4_SB(sb)->s_sbh); 1942 rc = ext4_mark_iloc_dirty(handle, inode, &iloc); 1943 if (!err) 1944 err = rc; 1945 1946 /* Only add to the head of the in-memory list if all the 1947 * previous operations succeeded. If the orphan_add is going to 1948 * fail (possibly taking the journal offline), we can't risk 1949 * leaving the inode on the orphan list: stray orphan-list 1950 * entries can cause panics at unmount time. 1951 * 1952 * This is safe: on error we're going to ignore the orphan list 1953 * anyway on the next recovery. */ 1954 if (!err) 1955 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan); 1956 1957 jbd_debug(4, "superblock will point to %lu\n", inode->i_ino); 1958 jbd_debug(4, "orphan inode %lu will point to %d\n", 1959 inode->i_ino, NEXT_ORPHAN(inode)); 1960 out_unlock: 1961 unlock_super(sb); 1962 ext4_std_error(inode->i_sb, err); 1963 return err; 1964 } 1965 1966 /* 1967 * ext4_orphan_del() removes an unlinked or truncated inode from the list 1968 * of such inodes stored on disk, because it is finally being cleaned up. 1969 */ 1970 int ext4_orphan_del(handle_t *handle, struct inode *inode) 1971 { 1972 struct list_head *prev; 1973 struct ext4_inode_info *ei = EXT4_I(inode); 1974 struct ext4_sb_info *sbi; 1975 unsigned long ino_next; 1976 struct ext4_iloc iloc; 1977 int err = 0; 1978 1979 lock_super(inode->i_sb); 1980 if (list_empty(&ei->i_orphan)) { 1981 unlock_super(inode->i_sb); 1982 return 0; 1983 } 1984 1985 ino_next = NEXT_ORPHAN(inode); 1986 prev = ei->i_orphan.prev; 1987 sbi = EXT4_SB(inode->i_sb); 1988 1989 jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino); 1990 1991 list_del_init(&ei->i_orphan); 1992 1993 /* If we're on an error path, we may not have a valid 1994 * transaction handle with which to update the orphan list on 1995 * disk, but we still need to remove the inode from the linked 1996 * list in memory. */ 1997 if (!handle) 1998 goto out; 1999 2000 err = ext4_reserve_inode_write(handle, inode, &iloc); 2001 if (err) 2002 goto out_err; 2003 2004 if (prev == &sbi->s_orphan) { 2005 jbd_debug(4, "superblock will point to %lu\n", ino_next); 2006 BUFFER_TRACE(sbi->s_sbh, "get_write_access"); 2007 err = ext4_journal_get_write_access(handle, sbi->s_sbh); 2008 if (err) 2009 goto out_brelse; 2010 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next); 2011 err = ext4_journal_dirty_metadata(handle, sbi->s_sbh); 2012 } else { 2013 struct ext4_iloc iloc2; 2014 struct inode *i_prev = 2015 &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode; 2016 2017 jbd_debug(4, "orphan inode %lu will point to %lu\n", 2018 i_prev->i_ino, ino_next); 2019 err = ext4_reserve_inode_write(handle, i_prev, &iloc2); 2020 if (err) 2021 goto out_brelse; 2022 NEXT_ORPHAN(i_prev) = ino_next; 2023 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2); 2024 } 2025 if (err) 2026 goto out_brelse; 2027 NEXT_ORPHAN(inode) = 0; 2028 err = ext4_mark_iloc_dirty(handle, inode, &iloc); 2029 2030 out_err: 2031 ext4_std_error(inode->i_sb, err); 2032 out: 2033 unlock_super(inode->i_sb); 2034 return err; 2035 2036 out_brelse: 2037 brelse(iloc.bh); 2038 goto out_err; 2039 } 2040 2041 static int ext4_rmdir (struct inode * dir, struct dentry *dentry) 2042 { 2043 int retval; 2044 struct inode * inode; 2045 struct buffer_head * bh; 2046 struct ext4_dir_entry_2 * de; 2047 handle_t *handle; 2048 2049 /* Initialize quotas before so that eventual writes go in 2050 * separate transaction */ 2051 DQUOT_INIT(dentry->d_inode); 2052 handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb)); 2053 if (IS_ERR(handle)) 2054 return PTR_ERR(handle); 2055 2056 retval = -ENOENT; 2057 bh = ext4_find_entry (dentry, &de); 2058 if (!bh) 2059 goto end_rmdir; 2060 2061 if (IS_DIRSYNC(dir)) 2062 handle->h_sync = 1; 2063 2064 inode = dentry->d_inode; 2065 2066 retval = -EIO; 2067 if (le32_to_cpu(de->inode) != inode->i_ino) 2068 goto end_rmdir; 2069 2070 retval = -ENOTEMPTY; 2071 if (!empty_dir (inode)) 2072 goto end_rmdir; 2073 2074 retval = ext4_delete_entry(handle, dir, de, bh); 2075 if (retval) 2076 goto end_rmdir; 2077 if (!EXT4_DIR_LINK_EMPTY(inode)) 2078 ext4_warning (inode->i_sb, "ext4_rmdir", 2079 "empty directory has too many links (%d)", 2080 inode->i_nlink); 2081 inode->i_version++; 2082 clear_nlink(inode); 2083 /* There's no need to set i_disksize: the fact that i_nlink is 2084 * zero will ensure that the right thing happens during any 2085 * recovery. */ 2086 inode->i_size = 0; 2087 ext4_orphan_add(handle, inode); 2088 inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode); 2089 ext4_mark_inode_dirty(handle, inode); 2090 ext4_dec_count(handle, dir); 2091 ext4_update_dx_flag(dir); 2092 ext4_mark_inode_dirty(handle, dir); 2093 2094 end_rmdir: 2095 ext4_journal_stop(handle); 2096 brelse (bh); 2097 return retval; 2098 } 2099 2100 static int ext4_unlink(struct inode * dir, struct dentry *dentry) 2101 { 2102 int retval; 2103 struct inode * inode; 2104 struct buffer_head * bh; 2105 struct ext4_dir_entry_2 * de; 2106 handle_t *handle; 2107 2108 /* Initialize quotas before so that eventual writes go 2109 * in separate transaction */ 2110 DQUOT_INIT(dentry->d_inode); 2111 handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb)); 2112 if (IS_ERR(handle)) 2113 return PTR_ERR(handle); 2114 2115 if (IS_DIRSYNC(dir)) 2116 handle->h_sync = 1; 2117 2118 retval = -ENOENT; 2119 bh = ext4_find_entry (dentry, &de); 2120 if (!bh) 2121 goto end_unlink; 2122 2123 inode = dentry->d_inode; 2124 2125 retval = -EIO; 2126 if (le32_to_cpu(de->inode) != inode->i_ino) 2127 goto end_unlink; 2128 2129 if (!inode->i_nlink) { 2130 ext4_warning (inode->i_sb, "ext4_unlink", 2131 "Deleting nonexistent file (%lu), %d", 2132 inode->i_ino, inode->i_nlink); 2133 inode->i_nlink = 1; 2134 } 2135 retval = ext4_delete_entry(handle, dir, de, bh); 2136 if (retval) 2137 goto end_unlink; 2138 dir->i_ctime = dir->i_mtime = ext4_current_time(dir); 2139 ext4_update_dx_flag(dir); 2140 ext4_mark_inode_dirty(handle, dir); 2141 ext4_dec_count(handle, inode); 2142 if (!inode->i_nlink) 2143 ext4_orphan_add(handle, inode); 2144 inode->i_ctime = ext4_current_time(inode); 2145 ext4_mark_inode_dirty(handle, inode); 2146 retval = 0; 2147 2148 end_unlink: 2149 ext4_journal_stop(handle); 2150 brelse (bh); 2151 return retval; 2152 } 2153 2154 static int ext4_symlink (struct inode * dir, 2155 struct dentry *dentry, const char * symname) 2156 { 2157 handle_t *handle; 2158 struct inode * inode; 2159 int l, err, retries = 0; 2160 2161 l = strlen(symname)+1; 2162 if (l > dir->i_sb->s_blocksize) 2163 return -ENAMETOOLONG; 2164 2165 retry: 2166 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2167 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 5 + 2168 2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb)); 2169 if (IS_ERR(handle)) 2170 return PTR_ERR(handle); 2171 2172 if (IS_DIRSYNC(dir)) 2173 handle->h_sync = 1; 2174 2175 inode = ext4_new_inode (handle, dir, S_IFLNK|S_IRWXUGO); 2176 err = PTR_ERR(inode); 2177 if (IS_ERR(inode)) 2178 goto out_stop; 2179 2180 if (l > sizeof (EXT4_I(inode)->i_data)) { 2181 inode->i_op = &ext4_symlink_inode_operations; 2182 ext4_set_aops(inode); 2183 /* 2184 * page_symlink() calls into ext4_prepare/commit_write. 2185 * We have a transaction open. All is sweetness. It also sets 2186 * i_size in generic_commit_write(). 2187 */ 2188 err = __page_symlink(inode, symname, l, 2189 mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS); 2190 if (err) { 2191 ext4_dec_count(handle, inode); 2192 ext4_mark_inode_dirty(handle, inode); 2193 iput (inode); 2194 goto out_stop; 2195 } 2196 } else { 2197 inode->i_op = &ext4_fast_symlink_inode_operations; 2198 memcpy((char*)&EXT4_I(inode)->i_data,symname,l); 2199 inode->i_size = l-1; 2200 } 2201 EXT4_I(inode)->i_disksize = inode->i_size; 2202 err = ext4_add_nondir(handle, dentry, inode); 2203 out_stop: 2204 ext4_journal_stop(handle); 2205 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2206 goto retry; 2207 return err; 2208 } 2209 2210 static int ext4_link (struct dentry * old_dentry, 2211 struct inode * dir, struct dentry *dentry) 2212 { 2213 handle_t *handle; 2214 struct inode *inode = old_dentry->d_inode; 2215 int err, retries = 0; 2216 2217 if (EXT4_DIR_LINK_MAX(inode)) 2218 return -EMLINK; 2219 2220 /* 2221 * Return -ENOENT if we've raced with unlink and i_nlink is 0. Doing 2222 * otherwise has the potential to corrupt the orphan inode list. 2223 */ 2224 if (inode->i_nlink == 0) 2225 return -ENOENT; 2226 2227 retry: 2228 handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + 2229 EXT4_INDEX_EXTRA_TRANS_BLOCKS); 2230 if (IS_ERR(handle)) 2231 return PTR_ERR(handle); 2232 2233 if (IS_DIRSYNC(dir)) 2234 handle->h_sync = 1; 2235 2236 inode->i_ctime = ext4_current_time(inode); 2237 ext4_inc_count(handle, inode); 2238 atomic_inc(&inode->i_count); 2239 2240 err = ext4_add_nondir(handle, dentry, inode); 2241 ext4_journal_stop(handle); 2242 if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) 2243 goto retry; 2244 return err; 2245 } 2246 2247 #define PARENT_INO(buffer) \ 2248 ((struct ext4_dir_entry_2 *) ((char *) buffer + \ 2249 le16_to_cpu(((struct ext4_dir_entry_2 *) buffer)->rec_len)))->inode 2250 2251 /* 2252 * Anybody can rename anything with this: the permission checks are left to the 2253 * higher-level routines. 2254 */ 2255 static int ext4_rename (struct inode * old_dir, struct dentry *old_dentry, 2256 struct inode * new_dir,struct dentry *new_dentry) 2257 { 2258 handle_t *handle; 2259 struct inode * old_inode, * new_inode; 2260 struct buffer_head * old_bh, * new_bh, * dir_bh; 2261 struct ext4_dir_entry_2 * old_de, * new_de; 2262 int retval; 2263 2264 old_bh = new_bh = dir_bh = NULL; 2265 2266 /* Initialize quotas before so that eventual writes go 2267 * in separate transaction */ 2268 if (new_dentry->d_inode) 2269 DQUOT_INIT(new_dentry->d_inode); 2270 handle = ext4_journal_start(old_dir, 2 * 2271 EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) + 2272 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2); 2273 if (IS_ERR(handle)) 2274 return PTR_ERR(handle); 2275 2276 if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir)) 2277 handle->h_sync = 1; 2278 2279 old_bh = ext4_find_entry (old_dentry, &old_de); 2280 /* 2281 * Check for inode number is _not_ due to possible IO errors. 2282 * We might rmdir the source, keep it as pwd of some process 2283 * and merrily kill the link to whatever was created under the 2284 * same name. Goodbye sticky bit ;-< 2285 */ 2286 old_inode = old_dentry->d_inode; 2287 retval = -ENOENT; 2288 if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino) 2289 goto end_rename; 2290 2291 new_inode = new_dentry->d_inode; 2292 new_bh = ext4_find_entry (new_dentry, &new_de); 2293 if (new_bh) { 2294 if (!new_inode) { 2295 brelse (new_bh); 2296 new_bh = NULL; 2297 } 2298 } 2299 if (S_ISDIR(old_inode->i_mode)) { 2300 if (new_inode) { 2301 retval = -ENOTEMPTY; 2302 if (!empty_dir (new_inode)) 2303 goto end_rename; 2304 } 2305 retval = -EIO; 2306 dir_bh = ext4_bread (handle, old_inode, 0, 0, &retval); 2307 if (!dir_bh) 2308 goto end_rename; 2309 if (le32_to_cpu(PARENT_INO(dir_bh->b_data)) != old_dir->i_ino) 2310 goto end_rename; 2311 retval = -EMLINK; 2312 if (!new_inode && new_dir!=old_dir && 2313 new_dir->i_nlink >= EXT4_LINK_MAX) 2314 goto end_rename; 2315 } 2316 if (!new_bh) { 2317 retval = ext4_add_entry (handle, new_dentry, old_inode); 2318 if (retval) 2319 goto end_rename; 2320 } else { 2321 BUFFER_TRACE(new_bh, "get write access"); 2322 ext4_journal_get_write_access(handle, new_bh); 2323 new_de->inode = cpu_to_le32(old_inode->i_ino); 2324 if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb, 2325 EXT4_FEATURE_INCOMPAT_FILETYPE)) 2326 new_de->file_type = old_de->file_type; 2327 new_dir->i_version++; 2328 BUFFER_TRACE(new_bh, "call ext4_journal_dirty_metadata"); 2329 ext4_journal_dirty_metadata(handle, new_bh); 2330 brelse(new_bh); 2331 new_bh = NULL; 2332 } 2333 2334 /* 2335 * Like most other Unix systems, set the ctime for inodes on a 2336 * rename. 2337 */ 2338 old_inode->i_ctime = ext4_current_time(old_inode); 2339 ext4_mark_inode_dirty(handle, old_inode); 2340 2341 /* 2342 * ok, that's it 2343 */ 2344 if (le32_to_cpu(old_de->inode) != old_inode->i_ino || 2345 old_de->name_len != old_dentry->d_name.len || 2346 strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) || 2347 (retval = ext4_delete_entry(handle, old_dir, 2348 old_de, old_bh)) == -ENOENT) { 2349 /* old_de could have moved from under us during htree split, so 2350 * make sure that we are deleting the right entry. We might 2351 * also be pointing to a stale entry in the unused part of 2352 * old_bh so just checking inum and the name isn't enough. */ 2353 struct buffer_head *old_bh2; 2354 struct ext4_dir_entry_2 *old_de2; 2355 2356 old_bh2 = ext4_find_entry(old_dentry, &old_de2); 2357 if (old_bh2) { 2358 retval = ext4_delete_entry(handle, old_dir, 2359 old_de2, old_bh2); 2360 brelse(old_bh2); 2361 } 2362 } 2363 if (retval) { 2364 ext4_warning(old_dir->i_sb, "ext4_rename", 2365 "Deleting old file (%lu), %d, error=%d", 2366 old_dir->i_ino, old_dir->i_nlink, retval); 2367 } 2368 2369 if (new_inode) { 2370 ext4_dec_count(handle, new_inode); 2371 new_inode->i_ctime = ext4_current_time(new_inode); 2372 } 2373 old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir); 2374 ext4_update_dx_flag(old_dir); 2375 if (dir_bh) { 2376 BUFFER_TRACE(dir_bh, "get_write_access"); 2377 ext4_journal_get_write_access(handle, dir_bh); 2378 PARENT_INO(dir_bh->b_data) = cpu_to_le32(new_dir->i_ino); 2379 BUFFER_TRACE(dir_bh, "call ext4_journal_dirty_metadata"); 2380 ext4_journal_dirty_metadata(handle, dir_bh); 2381 ext4_dec_count(handle, old_dir); 2382 if (new_inode) { 2383 /* checked empty_dir above, can't have another parent, 2384 * ext3_dec_count() won't work for many-linked dirs */ 2385 new_inode->i_nlink = 0; 2386 } else { 2387 ext4_inc_count(handle, new_dir); 2388 ext4_update_dx_flag(new_dir); 2389 ext4_mark_inode_dirty(handle, new_dir); 2390 } 2391 } 2392 ext4_mark_inode_dirty(handle, old_dir); 2393 if (new_inode) { 2394 ext4_mark_inode_dirty(handle, new_inode); 2395 if (!new_inode->i_nlink) 2396 ext4_orphan_add(handle, new_inode); 2397 } 2398 retval = 0; 2399 2400 end_rename: 2401 brelse (dir_bh); 2402 brelse (old_bh); 2403 brelse (new_bh); 2404 ext4_journal_stop(handle); 2405 return retval; 2406 } 2407 2408 /* 2409 * directories can handle most operations... 2410 */ 2411 const struct inode_operations ext4_dir_inode_operations = { 2412 .create = ext4_create, 2413 .lookup = ext4_lookup, 2414 .link = ext4_link, 2415 .unlink = ext4_unlink, 2416 .symlink = ext4_symlink, 2417 .mkdir = ext4_mkdir, 2418 .rmdir = ext4_rmdir, 2419 .mknod = ext4_mknod, 2420 .rename = ext4_rename, 2421 .setattr = ext4_setattr, 2422 #ifdef CONFIG_EXT4DEV_FS_XATTR 2423 .setxattr = generic_setxattr, 2424 .getxattr = generic_getxattr, 2425 .listxattr = ext4_listxattr, 2426 .removexattr = generic_removexattr, 2427 #endif 2428 .permission = ext4_permission, 2429 }; 2430 2431 const struct inode_operations ext4_special_inode_operations = { 2432 .setattr = ext4_setattr, 2433 #ifdef CONFIG_EXT4DEV_FS_XATTR 2434 .setxattr = generic_setxattr, 2435 .getxattr = generic_getxattr, 2436 .listxattr = ext4_listxattr, 2437 .removexattr = generic_removexattr, 2438 #endif 2439 .permission = ext4_permission, 2440 }; 2441