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