fs/ext4/namei.c

   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 #define NAMEI_RA_INDEX(c,b)  (((c) * NAMEI_RA_BLOCKS) + (b))
  51
  52 static struct buffer_head *ext4_append(handle_t *handle,
  53                                         struct inode *inode,
  54                                         ext4_lblk_t *block, int *err)
  55 {
  56         struct buffer_head *bh;
  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                 *err = -ENOSPC;
  62                 return NULL;
  63         }
  64
  65         *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
  66
  67         bh = ext4_bread(handle, inode, *block, 1, err);
  68         if (bh) {
  69                 inode->i_size += inode->i_sb->s_blocksize;
  70                 EXT4_I(inode)->i_disksize = inode->i_size;
  71                 *err = ext4_journal_get_write_access(handle, bh);
  72                 if (*err) {
  73                         brelse(bh);
  74                         bh = NULL;
  75                 }
  76         }
  77         if (!bh && !(*err)) {
  78                 *err = -EIO;
  79                 ext4_error(inode->i_sb,
  80                            "Directory hole detected on inode %lu\n",
  81                            inode->i_ino);
  82         }
  83         return bh;
  84 }
  85
  86 #ifndef assert
  87 #define assert(test) J_ASSERT(test)
  88 #endif
  89
  90 #ifdef DX_DEBUG
  91 #define dxtrace(command) command
  92 #else
  93 #define dxtrace(command)
  94 #endif
  95
  96 struct fake_dirent
  97 {
  98         __le32 inode;
  99         __le16 rec_len;
 100         u8 name_len;
 101         u8 file_type;
 102 };
 103
 104 struct dx_countlimit
 105 {
 106         __le16 limit;
 107         __le16 count;
 108 };
 109
 110 struct dx_entry
 111 {
 112         __le32 hash;
 113         __le32 block;
 114 };
 115
 116 /*
 117  * dx_root_info is laid out so that if it should somehow get overlaid by a
 118  * dirent the two low bits of the hash version will be zero.  Therefore, the
 119  * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
 120  */
 121
 122 struct dx_root
 123 {
 124         struct fake_dirent dot;
 125         char dot_name[4];
 126         struct fake_dirent dotdot;
 127         char dotdot_name[4];
 128         struct dx_root_info
 129         {
 130                 __le32 reserved_zero;
 131                 u8 hash_version;
 132                 u8 info_length; /* 8 */
 133                 u8 indirect_levels;
 134                 u8 unused_flags;
 135         }
 136         info;
 137         struct dx_entry entries[0];
 138 };
 139
 140 struct dx_node
 141 {
 142         struct fake_dirent fake;
 143         struct dx_entry entries[0];
 144 };
 145
 146
 147 struct dx_frame
 148 {
 149         struct buffer_head *bh;
 150         struct dx_entry *entries;
 151         struct dx_entry *at;
 152 };
 153
 154 struct dx_map_entry
 155 {
 156         u32 hash;
 157         u16 offs;
 158         u16 size;
 159 };
 160
 161 /*
 162  * This goes at the end of each htree block.
 163  */
 164 struct dx_tail {
 165         u32 dt_reserved;
 166         __le32 dt_checksum;     /* crc32c(uuid+inum+dirblock) */
 167 };
 168
 169 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
 170 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
 171 static inline unsigned dx_get_hash(struct dx_entry *entry);
 172 static void dx_set_hash(struct dx_entry *entry, unsigned value);
 173 static unsigned dx_get_count(struct dx_entry *entries);
 174 static unsigned dx_get_limit(struct dx_entry *entries);
 175 static void dx_set_count(struct dx_entry *entries, unsigned value);
 176 static void dx_set_limit(struct dx_entry *entries, unsigned value);
 177 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
 178 static unsigned dx_node_limit(struct inode *dir);
 179 static struct dx_frame *dx_probe(const struct qstr *d_name,
 180                                  struct inode *dir,
 181                                  struct dx_hash_info *hinfo,
 182                                  struct dx_frame *frame,
 183                                  int *err);
 184 static void dx_release(struct dx_frame *frames);
 185 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
 186                        struct dx_hash_info *hinfo, struct dx_map_entry map[]);
 187 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
 188 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
 189                 struct dx_map_entry *offsets, int count, unsigned blocksize);
 190 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
 191 static void dx_insert_block(struct dx_frame *frame,
 192                                         u32 hash, ext4_lblk_t block);
 193 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 194                                  struct dx_frame *frame,
 195                                  struct dx_frame *frames,
 196                                  __u32 *start_hash);
 197 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
 198                 const struct qstr *d_name,
 199                 struct ext4_dir_entry_2 **res_dir,
 200                 int *err);
 201 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
 202                              struct inode *inode);
 203
 204 /* checksumming functions */
 205 #define EXT4_DIRENT_TAIL(block, blocksize) \
 206         ((struct ext4_dir_entry_tail *)(((void *)(block)) + \
 207                                         ((blocksize) - \
 208                                          sizeof(struct ext4_dir_entry_tail))))
 209
 210 static void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
 211                                    unsigned int blocksize)
 212 {
 213         memset(t, 0, sizeof(struct ext4_dir_entry_tail));
 214         t->det_rec_len = ext4_rec_len_to_disk(
 215                         sizeof(struct ext4_dir_entry_tail), blocksize);
 216         t->det_reserved_ft = EXT4_FT_DIR_CSUM;
 217 }
 218
 219 /* Walk through a dirent block to find a checksum "dirent" at the tail */
 220 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
 221                                                    struct ext4_dir_entry *de)
 222 {
 223         struct ext4_dir_entry_tail *t;
 224
 225 #ifdef PARANOID
 226         struct ext4_dir_entry *d, *top;
 227
 228         d = de;
 229         top = (struct ext4_dir_entry *)(((void *)de) +
 230                 (EXT4_BLOCK_SIZE(inode->i_sb) -
 231                 sizeof(struct ext4_dir_entry_tail)));
 232         while (d < top && d->rec_len)
 233                 d = (struct ext4_dir_entry *)(((void *)d) +
 234                     le16_to_cpu(d->rec_len));
 235
 236         if (d != top)
 237                 return NULL;
 238
 239         t = (struct ext4_dir_entry_tail *)d;
 240 #else
 241         t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
 242 #endif
 243
 244         if (t->det_reserved_zero1 ||
 245             le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
 246             t->det_reserved_zero2 ||
 247             t->det_reserved_ft != EXT4_FT_DIR_CSUM)
 248                 return NULL;
 249
 250         return t;
 251 }
 252
 253 static __le32 ext4_dirent_csum(struct inode *inode,
 254                                struct ext4_dir_entry *dirent, int size)
 255 {
 256         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 257         struct ext4_inode_info *ei = EXT4_I(inode);
 258         __u32 csum;
 259
 260         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 261         return cpu_to_le32(csum);
 262 }
 263
 264 int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
 265 {
 266         struct ext4_dir_entry_tail *t;
 267
 268         if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
 269                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 270                 return 1;
 271
 272         t = get_dirent_tail(inode, dirent);
 273         if (!t) {
 274                 EXT4_ERROR_INODE(inode, "metadata_csum set but no space in dir "
 275                                  "leaf for checksum.  Please run e2fsck -D.");
 276                 return 0;
 277         }
 278
 279         if (t->det_checksum != ext4_dirent_csum(inode, dirent,
 280                                                 (void *)t - (void *)dirent))
 281                 return 0;
 282
 283         return 1;
 284 }
 285
 286 static void ext4_dirent_csum_set(struct inode *inode,
 287                                  struct ext4_dir_entry *dirent)
 288 {
 289         struct ext4_dir_entry_tail *t;
 290
 291         if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
 292                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 293                 return;
 294
 295         t = get_dirent_tail(inode, dirent);
 296         if (!t) {
 297                 EXT4_ERROR_INODE(inode, "metadata_csum set but no space in dir "
 298                                  "leaf for checksum.  Please run e2fsck -D.");
 299                 return;
 300         }
 301
 302         t->det_checksum = ext4_dirent_csum(inode, dirent,
 303                                            (void *)t - (void *)dirent);
 304 }
 305
 306 static inline int ext4_handle_dirty_dirent_node(handle_t *handle,
 307                                                 struct inode *inode,
 308                                                 struct buffer_head *bh)
 309 {
 310         ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 311         return ext4_handle_dirty_metadata(handle, inode, bh);
 312 }
 313
 314 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
 315                                                struct ext4_dir_entry *dirent,
 316                                                int *offset)
 317 {
 318         struct ext4_dir_entry *dp;
 319         struct dx_root_info *root;
 320         int count_offset;
 321
 322         if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
 323                 count_offset = 8;
 324         else if (le16_to_cpu(dirent->rec_len) == 12) {
 325                 dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
 326                 if (le16_to_cpu(dp->rec_len) !=
 327                     EXT4_BLOCK_SIZE(inode->i_sb) - 12)
 328                         return NULL;
 329                 root = (struct dx_root_info *)(((void *)dp + 12));
 330                 if (root->reserved_zero ||
 331                     root->info_length != sizeof(struct dx_root_info))
 332                         return NULL;
 333                 count_offset = 32;
 334         } else
 335                 return NULL;
 336
 337         if (offset)
 338                 *offset = count_offset;
 339         return (struct dx_countlimit *)(((void *)dirent) + count_offset);
 340 }
 341
 342 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
 343                            int count_offset, int count, struct dx_tail *t)
 344 {
 345         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 346         struct ext4_inode_info *ei = EXT4_I(inode);
 347         __u32 csum, old_csum;
 348         int size;
 349
 350         size = count_offset + (count * sizeof(struct dx_entry));
 351         old_csum = t->dt_checksum;
 352         t->dt_checksum = 0;
 353         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
 354         csum = ext4_chksum(sbi, csum, (__u8 *)t, sizeof(struct dx_tail));
 355         t->dt_checksum = old_csum;
 356
 357         return cpu_to_le32(csum);
 358 }
 359
 360 static int ext4_dx_csum_verify(struct inode *inode,
 361                                struct ext4_dir_entry *dirent)
 362 {
 363         struct dx_countlimit *c;
 364         struct dx_tail *t;
 365         int count_offset, limit, count;
 366
 367         if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
 368                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 369                 return 1;
 370
 371         c = get_dx_countlimit(inode, dirent, &count_offset);
 372         if (!c) {
 373                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 374                 return 1;
 375         }
 376         limit = le16_to_cpu(c->limit);
 377         count = le16_to_cpu(c->count);
 378         if (count_offset + (limit * sizeof(struct dx_entry)) >
 379             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 380                 EXT4_ERROR_INODE(inode, "metadata_csum set but no space for "
 381                                  "tree checksum found.  Run e2fsck -D.");
 382                 return 1;
 383         }
 384         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 385
 386         if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
 387                                             count, t))
 388                 return 0;
 389         return 1;
 390 }
 391
 392 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
 393 {
 394         struct dx_countlimit *c;
 395         struct dx_tail *t;
 396         int count_offset, limit, count;
 397
 398         if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
 399                                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 400                 return;
 401
 402         c = get_dx_countlimit(inode, dirent, &count_offset);
 403         if (!c) {
 404                 EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
 405                 return;
 406         }
 407         limit = le16_to_cpu(c->limit);
 408         count = le16_to_cpu(c->count);
 409         if (count_offset + (limit * sizeof(struct dx_entry)) >
 410             EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 411                 EXT4_ERROR_INODE(inode, "metadata_csum set but no space for "
 412                                  "tree checksum.  Run e2fsck -D.");
 413                 return;
 414         }
 415         t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
 416
 417         t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
 418 }
 419
 420 static inline int ext4_handle_dirty_dx_node(handle_t *handle,
 421                                             struct inode *inode,
 422                                             struct buffer_head *bh)
 423 {
 424         ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
 425         return ext4_handle_dirty_metadata(handle, inode, bh);
 426 }
 427
 428 /*
 429  * p is at least 6 bytes before the end of page
 430  */
 431 static inline struct ext4_dir_entry_2 *
 432 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
 433 {
 434         return (struct ext4_dir_entry_2 *)((char *)p +
 435                 ext4_rec_len_from_disk(p->rec_len, blocksize));
 436 }
 437
 438 /*
 439  * Future: use high four bits of block for coalesce-on-delete flags
 440  * Mask them off for now.
 441  */
 442
 443 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
 444 {
 445         return le32_to_cpu(entry->block) & 0x00ffffff;
 446 }
 447
 448 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
 449 {
 450         entry->block = cpu_to_le32(value);
 451 }
 452
 453 static inline unsigned dx_get_hash(struct dx_entry *entry)
 454 {
 455         return le32_to_cpu(entry->hash);
 456 }
 457
 458 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
 459 {
 460         entry->hash = cpu_to_le32(value);
 461 }
 462
 463 static inline unsigned dx_get_count(struct dx_entry *entries)
 464 {
 465         return le16_to_cpu(((struct dx_countlimit *) entries)->count);
 466 }
 467
 468 static inline unsigned dx_get_limit(struct dx_entry *entries)
 469 {
 470         return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
 471 }
 472
 473 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
 474 {
 475         ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
 476 }
 477
 478 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
 479 {
 480         ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
 481 }
 482
 483 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
 484 {
 485         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
 486                 EXT4_DIR_REC_LEN(2) - infosize;
 487
 488         if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
 489                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 490                 entry_space -= sizeof(struct dx_tail);
 491         return entry_space / sizeof(struct dx_entry);
 492 }
 493
 494 static inline unsigned dx_node_limit(struct inode *dir)
 495 {
 496         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
 497
 498         if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
 499                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 500                 entry_space -= sizeof(struct dx_tail);
 501         return entry_space / sizeof(struct dx_entry);
 502 }
 503
 504 /*
 505  * Debug
 506  */
 507 #ifdef DX_DEBUG
 508 static void dx_show_index(char * label, struct dx_entry *entries)
 509 {
 510         int i, n = dx_get_count (entries);
 511         printk(KERN_DEBUG "%s index ", label);
 512         for (i = 0; i < n; i++) {
 513                 printk("%x->%lu ", i ? dx_get_hash(entries + i) :
 514                                 0, (unsigned long)dx_get_block(entries + i));
 515         }
 516         printk("\n");
 517 }
 518
 519 struct stats
 520 {
 521         unsigned names;
 522         unsigned space;
 523         unsigned bcount;
 524 };
 525
 526 static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
 527                                  int size, int show_names)
 528 {
 529         unsigned names = 0, space = 0;
 530         char *base = (char *) de;
 531         struct dx_hash_info h = *hinfo;
 532
 533         printk("names: ");
 534         while ((char *) de < base + size)
 535         {
 536                 if (de->inode)
 537                 {
 538                         if (show_names)
 539                         {
 540                                 int len = de->name_len;
 541                                 char *name = de->name;
 542                                 while (len--) printk("%c", *name++);
 543                                 ext4fs_dirhash(de->name, de->name_len, &h);
 544                                 printk(":%x.%u ", h.hash,
 545                                        (unsigned) ((char *) de - base));
 546                         }
 547                         space += EXT4_DIR_REC_LEN(de->name_len);
 548                         names++;
 549                 }
 550                 de = ext4_next_entry(de, size);
 551         }
 552         printk("(%i)\n", names);
 553         return (struct stats) { names, space, 1 };
 554 }
 555
 556 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
 557                              struct dx_entry *entries, int levels)
 558 {
 559         unsigned blocksize = dir->i_sb->s_blocksize;
 560         unsigned count = dx_get_count(entries), names = 0, space = 0, i;
 561         unsigned bcount = 0;
 562         struct buffer_head *bh;
 563         int err;
 564         printk("%i indexed blocks...\n", count);
 565         for (i = 0; i < count; i++, entries++)
 566         {
 567                 ext4_lblk_t block = dx_get_block(entries);
 568                 ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
 569                 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
 570                 struct stats stats;
 571                 printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
 572                 if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue;
 573                 stats = levels?
 574                    dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
 575                    dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0);
 576                 names += stats.names;
 577                 space += stats.space;
 578                 bcount += stats.bcount;
 579                 brelse(bh);
 580         }
 581         if (bcount)
 582                 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
 583                        levels ? "" : "   ", names, space/bcount,
 584                        (space/bcount)*100/blocksize);
 585         return (struct stats) { names, space, bcount};
 586 }
 587 #endif /* DX_DEBUG */
 588
 589 /*
 590  * Probe for a directory leaf block to search.
 591  *
 592  * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
 593  * error in the directory index, and the caller should fall back to
 594  * searching the directory normally.  The callers of dx_probe **MUST**
 595  * check for this error code, and make sure it never gets reflected
 596  * back to userspace.
 597  */
 598 static struct dx_frame *
 599 dx_probe(const struct qstr *d_name, struct inode *dir,
 600          struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err)
 601 {
 602         unsigned count, indirect;
 603         struct dx_entry *at, *entries, *p, *q, *m;
 604         struct dx_root *root;
 605         struct buffer_head *bh;
 606         struct dx_frame *frame = frame_in;
 607         u32 hash;
 608
 609         frame->bh = NULL;
 610         if (!(bh = ext4_bread(NULL, dir, 0, 0, err))) {
 611                 if (*err == 0)
 612                         *err = ERR_BAD_DX_DIR;
 613                 goto fail;
 614         }
 615         root = (struct dx_root *) bh->b_data;
 616         if (root->info.hash_version != DX_HASH_TEA &&
 617             root->info.hash_version != DX_HASH_HALF_MD4 &&
 618             root->info.hash_version != DX_HASH_LEGACY) {
 619                 ext4_warning(dir->i_sb, "Unrecognised inode hash code %d",
 620                              root->info.hash_version);
 621                 brelse(bh);
 622                 *err = ERR_BAD_DX_DIR;
 623                 goto fail;
 624         }
 625         hinfo->hash_version = root->info.hash_version;
 626         if (hinfo->hash_version <= DX_HASH_TEA)
 627                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 628         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 629         if (d_name)
 630                 ext4fs_dirhash(d_name->name, d_name->len, hinfo);
 631         hash = hinfo->hash;
 632
 633         if (root->info.unused_flags & 1) {
 634                 ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x",
 635                              root->info.unused_flags);
 636                 brelse(bh);
 637                 *err = ERR_BAD_DX_DIR;
 638                 goto fail;
 639         }
 640
 641         if ((indirect = root->info.indirect_levels) > 1) {
 642                 ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x",
 643                              root->info.indirect_levels);
 644                 brelse(bh);
 645                 *err = ERR_BAD_DX_DIR;
 646                 goto fail;
 647         }
 648
 649         if (!buffer_verified(bh) &&
 650             !ext4_dx_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data)) {
 651                 ext4_warning(dir->i_sb, "Root failed checksum");
 652                 brelse(bh);
 653                 *err = ERR_BAD_DX_DIR;
 654                 goto fail;
 655         }
 656         set_buffer_verified(bh);
 657
 658         entries = (struct dx_entry *) (((char *)&root->info) +
 659                                        root->info.info_length);
 660
 661         if (dx_get_limit(entries) != dx_root_limit(dir,
 662                                                    root->info.info_length)) {
 663                 ext4_warning(dir->i_sb, "dx entry: limit != root limit");
 664                 brelse(bh);
 665                 *err = ERR_BAD_DX_DIR;
 666                 goto fail;
 667         }
 668
 669         dxtrace(printk("Look up %x", hash));
 670         while (1)
 671         {
 672                 count = dx_get_count(entries);
 673                 if (!count || count > dx_get_limit(entries)) {
 674                         ext4_warning(dir->i_sb,
 675                                      "dx entry: no count or count > limit");
 676                         brelse(bh);
 677                         *err = ERR_BAD_DX_DIR;
 678                         goto fail2;
 679                 }
 680
 681                 p = entries + 1;
 682                 q = entries + count - 1;
 683                 while (p <= q)
 684                 {
 685                         m = p + (q - p)/2;
 686                         dxtrace(printk("."));
 687                         if (dx_get_hash(m) > hash)
 688                                 q = m - 1;
 689                         else
 690                                 p = m + 1;
 691                 }
 692
 693                 if (0) // linear search cross check
 694                 {
 695                         unsigned n = count - 1;
 696                         at = entries;
 697                         while (n--)
 698                         {
 699                                 dxtrace(printk(","));
 700                                 if (dx_get_hash(++at) > hash)
 701                                 {
 702                                         at--;
 703                                         break;
 704                                 }
 705                         }
 706                         assert (at == p - 1);
 707                 }
 708
 709                 at = p - 1;
 710                 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
 711                 frame->bh = bh;
 712                 frame->entries = entries;
 713                 frame->at = at;
 714                 if (!indirect--) return frame;
 715                 if (!(bh = ext4_bread(NULL, dir, dx_get_block(at), 0, err))) {
 716                         if (!(*err))
 717                                 *err = ERR_BAD_DX_DIR;
 718                         goto fail2;
 719                 }
 720                 at = entries = ((struct dx_node *) bh->b_data)->entries;
 721
 722                 if (!buffer_verified(bh) &&
 723                     !ext4_dx_csum_verify(dir,
 724                                          (struct ext4_dir_entry *)bh->b_data)) {
 725                         ext4_warning(dir->i_sb, "Node failed checksum");
 726                         brelse(bh);
 727                         *err = ERR_BAD_DX_DIR;
 728                         goto fail;
 729                 }
 730                 set_buffer_verified(bh);
 731
 732                 if (dx_get_limit(entries) != dx_node_limit (dir)) {
 733                         ext4_warning(dir->i_sb,
 734                                      "dx entry: limit != node limit");
 735                         brelse(bh);
 736                         *err = ERR_BAD_DX_DIR;
 737                         goto fail2;
 738                 }
 739                 frame++;
 740                 frame->bh = NULL;
 741         }
 742 fail2:
 743         while (frame >= frame_in) {
 744                 brelse(frame->bh);
 745                 frame--;
 746         }
 747 fail:
 748         if (*err == ERR_BAD_DX_DIR)
 749                 ext4_warning(dir->i_sb,
 750                              "Corrupt dir inode %lu, running e2fsck is "
 751                              "recommended.", dir->i_ino);
 752         return NULL;
 753 }
 754
 755 static void dx_release (struct dx_frame *frames)
 756 {
 757         if (frames[0].bh == NULL)
 758                 return;
 759
 760         if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
 761                 brelse(frames[1].bh);
 762         brelse(frames[0].bh);
 763 }
 764
 765 /*
 766  * This function increments the frame pointer to search the next leaf
 767  * block, and reads in the necessary intervening nodes if the search
 768  * should be necessary.  Whether or not the search is necessary is
 769  * controlled by the hash parameter.  If the hash value is even, then
 770  * the search is only continued if the next block starts with that
 771  * hash value.  This is used if we are searching for a specific file.
 772  *
 773  * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
 774  *
 775  * This function returns 1 if the caller should continue to search,
 776  * or 0 if it should not.  If there is an error reading one of the
 777  * index blocks, it will a negative error code.
 778  *
 779  * If start_hash is non-null, it will be filled in with the starting
 780  * hash of the next page.
 781  */
 782 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 783                                  struct dx_frame *frame,
 784                                  struct dx_frame *frames,
 785                                  __u32 *start_hash)
 786 {
 787         struct dx_frame *p;
 788         struct buffer_head *bh;
 789         int err, num_frames = 0;
 790         __u32 bhash;
 791
 792         p = frame;
 793         /*
 794          * Find the next leaf page by incrementing the frame pointer.
 795          * If we run out of entries in the interior node, loop around and
 796          * increment pointer in the parent node.  When we break out of
 797          * this loop, num_frames indicates the number of interior
 798          * nodes need to be read.
 799          */
 800         while (1) {
 801                 if (++(p->at) < p->entries + dx_get_count(p->entries))
 802                         break;
 803                 if (p == frames)
 804                         return 0;
 805                 num_frames++;
 806                 p--;
 807         }
 808
 809         /*
 810          * If the hash is 1, then continue only if the next page has a
 811          * continuation hash of any value.  This is used for readdir
 812          * handling.  Otherwise, check to see if the hash matches the
 813          * desired contiuation hash.  If it doesn't, return since
 814          * there's no point to read in the successive index pages.
 815          */
 816         bhash = dx_get_hash(p->at);
 817         if (start_hash)
 818                 *start_hash = bhash;
 819         if ((hash & 1) == 0) {
 820                 if ((bhash & ~1) != hash)
 821                         return 0;
 822         }
 823         /*
 824          * If the hash is HASH_NB_ALWAYS, we always go to the next
 825          * block so no check is necessary
 826          */
 827         while (num_frames--) {
 828                 if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at),
 829                                       0, &err))) {
 830                         if (!err) {
 831                                 ext4_error(dir->i_sb,
 832                                            "Directory hole detected on inode %lu\n",
 833                                            dir->i_ino);
 834                                 return -EIO;
 835                         }
 836                         return err; /* Failure */
 837                 }
 838
 839                 if (!buffer_verified(bh) &&
 840                     !ext4_dx_csum_verify(dir,
 841                                          (struct ext4_dir_entry *)bh->b_data)) {
 842                         ext4_warning(dir->i_sb, "Node failed checksum");
 843                         return -EIO;
 844                 }
 845                 set_buffer_verified(bh);
 846
 847                 p++;
 848                 brelse(p->bh);
 849                 p->bh = bh;
 850                 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
 851         }
 852         return 1;
 853 }
 854
 855
 856 /*
 857  * This function fills a red-black tree with information from a
 858  * directory block.  It returns the number directory entries loaded
 859  * into the tree.  If there is an error it is returned in err.
 860  */
 861 static int htree_dirblock_to_tree(struct file *dir_file,
 862                                   struct inode *dir, ext4_lblk_t block,
 863                                   struct dx_hash_info *hinfo,
 864                                   __u32 start_hash, __u32 start_minor_hash)
 865 {
 866         struct buffer_head *bh;
 867         struct ext4_dir_entry_2 *de, *top;
 868         int err = 0, count = 0;
 869
 870         dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
 871                                                         (unsigned long)block));
 872         if (!(bh = ext4_bread(NULL, dir, block, 0, &err))) {
 873                 if (!err) {
 874                         err = -EIO;
 875                         ext4_error(dir->i_sb,
 876                                    "Directory hole detected on inode %lu\n",
 877                                    dir->i_ino);
 878                 }
 879                 return err;
 880         }
 881
 882         if (!buffer_verified(bh) &&
 883             !ext4_dirent_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data))
 884                 return -EIO;
 885         set_buffer_verified(bh);
 886
 887         de = (struct ext4_dir_entry_2 *) bh->b_data;
 888         top = (struct ext4_dir_entry_2 *) ((char *) de +
 889                                            dir->i_sb->s_blocksize -
 890                                            EXT4_DIR_REC_LEN(0));
 891         for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
 892                 if (ext4_check_dir_entry(dir, NULL, de, bh,
 893                                 (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
 894                                          + ((char *)de - bh->b_data))) {
 895                         /* On error, skip the f_pos to the next block. */
 896                         dir_file->f_pos = (dir_file->f_pos |
 897                                         (dir->i_sb->s_blocksize - 1)) + 1;
 898                         brelse(bh);
 899                         return count;
 900                 }
 901                 ext4fs_dirhash(de->name, de->name_len, hinfo);
 902                 if ((hinfo->hash < start_hash) ||
 903                     ((hinfo->hash == start_hash) &&
 904                      (hinfo->minor_hash < start_minor_hash)))
 905                         continue;
 906                 if (de->inode == 0)
 907                         continue;
 908                 if ((err = ext4_htree_store_dirent(dir_file,
 909                                    hinfo->hash, hinfo->minor_hash, de)) != 0) {
 910                         brelse(bh);
 911                         return err;
 912                 }
 913                 count++;
 914         }
 915         brelse(bh);
 916         return count;
 917 }
 918
 919
 920 /*
 921  * This function fills a red-black tree with information from a
 922  * directory.  We start scanning the directory in hash order, starting
 923  * at start_hash and start_minor_hash.
 924  *
 925  * This function returns the number of entries inserted into the tree,
 926  * or a negative error code.
 927  */
 928 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
 929                          __u32 start_minor_hash, __u32 *next_hash)
 930 {
 931         struct dx_hash_info hinfo;
 932         struct ext4_dir_entry_2 *de;
 933         struct dx_frame frames[2], *frame;
 934         struct inode *dir;
 935         ext4_lblk_t block;
 936         int count = 0;
 937         int ret, err;
 938         __u32 hashval;
 939
 940         dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
 941                        start_hash, start_minor_hash));
 942         dir = dir_file->f_path.dentry->d_inode;
 943         if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
 944                 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
 945                 if (hinfo.hash_version <= DX_HASH_TEA)
 946                         hinfo.hash_version +=
 947                                 EXT4_SB(dir->i_sb)->s_hash_unsigned;
 948                 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 949                 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
 950                                                start_hash, start_minor_hash);
 951                 *next_hash = ~0;
 952                 return count;
 953         }
 954         hinfo.hash = start_hash;
 955         hinfo.minor_hash = 0;
 956         frame = dx_probe(NULL, dir, &hinfo, frames, &err);
 957         if (!frame)
 958                 return err;
 959
 960         /* Add '.' and '..' from the htree header */
 961         if (!start_hash && !start_minor_hash) {
 962                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
 963                 if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
 964                         goto errout;
 965                 count++;
 966         }
 967         if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
 968                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
 969                 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
 970                 if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
 971                         goto errout;
 972                 count++;
 973         }
 974
 975         while (1) {
 976                 block = dx_get_block(frame->at);
 977                 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
 978                                              start_hash, start_minor_hash);
 979                 if (ret < 0) {
 980                         err = ret;
 981                         goto errout;
 982                 }
 983                 count += ret;
 984                 hashval = ~0;
 985                 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
 986                                             frame, frames, &hashval);
 987                 *next_hash = hashval;
 988                 if (ret < 0) {
 989                         err = ret;
 990                         goto errout;
 991                 }
 992                 /*
 993                  * Stop if:  (a) there are no more entries, or
 994                  * (b) we have inserted at least one entry and the
 995                  * next hash value is not a continuation
 996                  */
 997                 if ((ret == 0) ||
 998                     (count && ((hashval & 1) == 0)))
 999                         break;
1000         }
1001         dx_release(frames);
1002         dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1003                        "next hash: %x\n", count, *next_hash));
1004         return count;
1005 errout:
1006         dx_release(frames);
1007         return (err);
1008 }
1009
1010
1011 /*
1012  * Directory block splitting, compacting
1013  */
1014
1015 /*
1016  * Create map of hash values, offsets, and sizes, stored at end of block.
1017  * Returns number of entries mapped.
1018  */
1019 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
1020                        struct dx_hash_info *hinfo,
1021                        struct dx_map_entry *map_tail)
1022 {
1023         int count = 0;
1024         char *base = (char *) de;
1025         struct dx_hash_info h = *hinfo;
1026
1027         while ((char *) de < base + blocksize) {
1028                 if (de->name_len && de->inode) {
1029                         ext4fs_dirhash(de->name, de->name_len, &h);
1030                         map_tail--;
1031                         map_tail->hash = h.hash;
1032                         map_tail->offs = ((char *) de - base)>>2;
1033                         map_tail->size = le16_to_cpu(de->rec_len);
1034                         count++;
1035                         cond_resched();
1036                 }
1037                 /* XXX: do we need to check rec_len == 0 case? -Chris */
1038                 de = ext4_next_entry(de, blocksize);
1039         }
1040         return count;
1041 }
1042
1043 /* Sort map by hash value */
1044 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1045 {
1046         struct dx_map_entry *p, *q, *top = map + count - 1;
1047         int more;
1048         /* Combsort until bubble sort doesn't suck */
1049         while (count > 2) {
1050                 count = count*10/13;
1051                 if (count - 9 < 2) /* 9, 10 -> 11 */
1052                         count = 11;
1053                 for (p = top, q = p - count; q >= map; p--, q--)
1054                         if (p->hash < q->hash)
1055                                 swap(*p, *q);
1056         }
1057         /* Garden variety bubble sort */
1058         do {
1059                 more = 0;
1060                 q = top;
1061                 while (q-- > map) {
1062                         if (q[1].hash >= q[0].hash)
1063                                 continue;
1064                         swap(*(q+1), *q);
1065                         more = 1;
1066                 }
1067         } while(more);
1068 }
1069
1070 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1071 {
1072         struct dx_entry *entries = frame->entries;
1073         struct dx_entry *old = frame->at, *new = old + 1;
1074         int count = dx_get_count(entries);
1075
1076         assert(count < dx_get_limit(entries));
1077         assert(old < entries + count);
1078         memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1079         dx_set_hash(new, hash);
1080         dx_set_block(new, block);
1081         dx_set_count(entries, count + 1);
1082 }
1083
1084 static void ext4_update_dx_flag(struct inode *inode)
1085 {
1086         if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
1087                                      EXT4_FEATURE_COMPAT_DIR_INDEX))
1088                 ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
1089 }
1090
1091 /*
1092  * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
1093  *
1094  * `len <= EXT4_NAME_LEN' is guaranteed by caller.
1095  * `de != NULL' is guaranteed by caller.
1096  */
1097 static inline int ext4_match (int len, const char * const name,
1098                               struct ext4_dir_entry_2 * de)
1099 {
1100         if (len != de->name_len)
1101                 return 0;
1102         if (!de->inode)
1103                 return 0;
1104         return !memcmp(name, de->name, len);
1105 }
1106
1107 /*
1108  * Returns 0 if not found, -1 on failure, and 1 on success
1109  */
1110 static inline int search_dirblock(struct buffer_head *bh,
1111                                   struct inode *dir,
1112                                   const struct qstr *d_name,
1113                                   unsigned int offset,
1114                                   struct ext4_dir_entry_2 ** res_dir)
1115 {
1116         struct ext4_dir_entry_2 * de;
1117         char * dlimit;
1118         int de_len;
1119         const char *name = d_name->name;
1120         int namelen = d_name->len;
1121
1122         de = (struct ext4_dir_entry_2 *) bh->b_data;
1123         dlimit = bh->b_data + dir->i_sb->s_blocksize;
1124         while ((char *) de < dlimit) {
1125                 /* this code is executed quadratically often */
1126                 /* do minimal checking `by hand' */
1127
1128                 if ((char *) de + namelen <= dlimit &&
1129                     ext4_match (namelen, name, de)) {
1130                         /* found a match - just to be sure, do a full check */
1131                         if (ext4_check_dir_entry(dir, NULL, de, bh, offset))
1132                                 return -1;
1133                         *res_dir = de;
1134                         return 1;
1135                 }
1136                 /* prevent looping on a bad block */
1137                 de_len = ext4_rec_len_from_disk(de->rec_len,
1138                                                 dir->i_sb->s_blocksize);
1139                 if (de_len <= 0)
1140                         return -1;
1141                 offset += de_len;
1142                 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1143         }
1144         return 0;
1145 }
1146
1147
1148 /*
1149  *      ext4_find_entry()
1150  *
1151  * finds an entry in the specified directory with the wanted name. It
1152  * returns the cache buffer in which the entry was found, and the entry
1153  * itself (as a parameter - res_dir). It does NOT read the inode of the
1154  * entry - you'll have to do that yourself if you want to.
1155  *
1156  * The returned buffer_head has ->b_count elevated.  The caller is expected
1157  * to brelse() it when appropriate.
1158  */
1159 static struct buffer_head * ext4_find_entry (struct inode *dir,
1160                                         const struct qstr *d_name,
1161                                         struct ext4_dir_entry_2 ** res_dir)
1162 {
1163         struct super_block *sb;
1164         struct buffer_head *bh_use[NAMEI_RA_SIZE];
1165         struct buffer_head *bh, *ret = NULL;
1166         ext4_lblk_t start, block, b;
1167         const u8 *name = d_name->name;
1168         int ra_max = 0;         /* Number of bh's in the readahead
1169                                    buffer, bh_use[] */
1170         int ra_ptr = 0;         /* Current index into readahead
1171                                    buffer */
1172         int num = 0;
1173         ext4_lblk_t  nblocks;
1174         int i, err;
1175         int namelen;
1176
1177         *res_dir = NULL;
1178         sb = dir->i_sb;
1179         namelen = d_name->len;
1180         if (namelen > EXT4_NAME_LEN)
1181                 return NULL;
1182         if ((namelen <= 2) && (name[0] == '.') &&
1183             (name[1] == '.' || name[1] == '\0')) {
1184                 /*
1185                  * "." or ".." will only be in the first block
1186                  * NFS may look up ".."; "." should be handled by the VFS
1187                  */
1188                 block = start = 0;
1189                 nblocks = 1;
1190                 goto restart;
1191         }
1192         if (is_dx(dir)) {
1193                 bh = ext4_dx_find_entry(dir, d_name, res_dir, &err);
1194                 /*
1195                  * On success, or if the error was file not found,
1196                  * return.  Otherwise, fall back to doing a search the
1197                  * old fashioned way.
1198                  */
1199                 if (bh || (err != ERR_BAD_DX_DIR))
1200                         return bh;
1201                 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1202                                "falling back\n"));
1203         }
1204         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1205         start = EXT4_I(dir)->i_dir_start_lookup;
1206         if (start >= nblocks)
1207                 start = 0;
1208         block = start;
1209 restart:
1210         do {
1211                 /*
1212                  * We deal with the read-ahead logic here.
1213                  */
1214                 if (ra_ptr >= ra_max) {
1215                         /* Refill the readahead buffer */
1216                         ra_ptr = 0;
1217                         b = block;
1218                         for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
1219                                 /*
1220                                  * Terminate if we reach the end of the
1221                                  * directory and must wrap, or if our
1222                                  * search has finished at this block.
1223                                  */
1224                                 if (b >= nblocks || (num && block == start)) {
1225                                         bh_use[ra_max] = NULL;
1226                                         break;
1227                                 }
1228                                 num++;
1229                                 bh = ext4_getblk(NULL, dir, b++, 0, &err);
1230                                 bh_use[ra_max] = bh;
1231                                 if (bh)
1232                                         ll_rw_block(READ | REQ_META | REQ_PRIO,
1233                                                     1, &bh);
1234                         }
1235                 }
1236                 if ((bh = bh_use[ra_ptr++]) == NULL)
1237                         goto next;
1238                 wait_on_buffer(bh);
1239                 if (!buffer_uptodate(bh)) {
1240                         /* read error, skip block & hope for the best */
1241                         EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1242                                          (unsigned long) block);
1243                         brelse(bh);
1244                         goto next;
1245                 }
1246                 if (!buffer_verified(bh) &&
1247                     !ext4_dirent_csum_verify(dir,
1248                                 (struct ext4_dir_entry *)bh->b_data)) {
1249                         EXT4_ERROR_INODE(dir, "checksumming directory "
1250                                          "block %lu", (unsigned long)block);
1251                         brelse(bh);
1252                         goto next;
1253                 }
1254                 set_buffer_verified(bh);
1255                 i = search_dirblock(bh, dir, d_name,
1256                             block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1257                 if (i == 1) {
1258                         EXT4_I(dir)->i_dir_start_lookup = block;
1259                         ret = bh;
1260                         goto cleanup_and_exit;
1261                 } else {
1262                         brelse(bh);
1263                         if (i < 0)
1264                                 goto cleanup_and_exit;
1265                 }
1266         next:
1267                 if (++block >= nblocks)
1268                         block = 0;
1269         } while (block != start);
1270
1271         /*
1272          * If the directory has grown while we were searching, then
1273          * search the last part of the directory before giving up.
1274          */
1275         block = nblocks;
1276         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1277         if (block < nblocks) {
1278                 start = 0;
1279                 goto restart;
1280         }
1281
1282 cleanup_and_exit:
1283         /* Clean up the read-ahead blocks */
1284         for (; ra_ptr < ra_max; ra_ptr++)
1285                 brelse(bh_use[ra_ptr]);
1286         return ret;
1287 }
1288
1289 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
1290                        struct ext4_dir_entry_2 **res_dir, int *err)
1291 {
1292         struct super_block * sb = dir->i_sb;
1293         struct dx_hash_info     hinfo;
1294         struct dx_frame frames[2], *frame;
1295         struct buffer_head *bh;
1296         ext4_lblk_t block;
1297         int retval;
1298
1299         if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err)))
1300                 return NULL;
1301         do {
1302                 block = dx_get_block(frame->at);
1303                 if (!(bh = ext4_bread(NULL, dir, block, 0, err))) {
1304                         if (!(*err)) {
1305                                 *err = -EIO;
1306                                 ext4_error(dir->i_sb,
1307                                            "Directory hole detected on inode %lu\n",
1308                                            dir->i_ino);
1309                         }
1310                         goto errout;
1311                 }
1312
1313                 if (!buffer_verified(bh) &&
1314                     !ext4_dirent_csum_verify(dir,
1315                                 (struct ext4_dir_entry *)bh->b_data)) {
1316                         EXT4_ERROR_INODE(dir, "checksumming directory "
1317                                          "block %lu", (unsigned long)block);
1318                         brelse(bh);
1319                         *err = -EIO;
1320                         goto errout;
1321                 }
1322                 set_buffer_verified(bh);
1323                 retval = search_dirblock(bh, dir, d_name,
1324                                          block << EXT4_BLOCK_SIZE_BITS(sb),
1325                                          res_dir);
1326                 if (retval == 1) {      /* Success! */
1327                         dx_release(frames);
1328                         return bh;
1329                 }
1330                 brelse(bh);
1331                 if (retval == -1) {
1332                         *err = ERR_BAD_DX_DIR;
1333                         goto errout;
1334                 }
1335
1336                 /* Check to see if we should continue to search */
1337                 retval = ext4_htree_next_block(dir, hinfo.hash, frame,
1338                                                frames, NULL);
1339                 if (retval < 0) {
1340                         ext4_warning(sb,
1341                              "error reading index page in directory #%lu",
1342                              dir->i_ino);
1343                         *err = retval;
1344                         goto errout;
1345                 }
1346         } while (retval == 1);
1347
1348         *err = -ENOENT;
1349 errout:
1350         dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
1351         dx_release (frames);
1352         return NULL;
1353 }
1354
1355 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1356 {
1357         struct inode *inode;
1358         struct ext4_dir_entry_2 *de;
1359         struct buffer_head *bh;
1360
1361         if (dentry->d_name.len > EXT4_NAME_LEN)
1362                 return ERR_PTR(-ENAMETOOLONG);
1363
1364         bh = ext4_find_entry(dir, &dentry->d_name, &de);
1365         inode = NULL;
1366         if (bh) {
1367                 __u32 ino = le32_to_cpu(de->inode);
1368                 brelse(bh);
1369                 if (!ext4_valid_inum(dir->i_sb, ino)) {
1370                         EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1371                         return ERR_PTR(-EIO);
1372                 }
1373                 if (unlikely(ino == dir->i_ino)) {
1374                         EXT4_ERROR_INODE(dir, "'%.*s' linked to parent dir",
1375                                          dentry->d_name.len,
1376                                          dentry->d_name.name);
1377                         return ERR_PTR(-EIO);
1378                 }
1379                 inode = ext4_iget(dir->i_sb, ino);
1380                 if (inode == ERR_PTR(-ESTALE)) {
1381                         EXT4_ERROR_INODE(dir,
1382                                          "deleted inode referenced: %u",
1383                                          ino);
1384                         return ERR_PTR(-EIO);
1385                 }
1386         }
1387         return d_splice_alias(inode, dentry);
1388 }
1389
1390
1391 struct dentry *ext4_get_parent(struct dentry *child)
1392 {
1393         __u32 ino;
1394         static const struct qstr dotdot = QSTR_INIT("..", 2);
1395         struct ext4_dir_entry_2 * de;
1396         struct buffer_head *bh;
1397
1398         bh = ext4_find_entry(child->d_inode, &dotdot, &de);
1399         if (!bh)
1400                 return ERR_PTR(-ENOENT);
1401         ino = le32_to_cpu(de->inode);
1402         brelse(bh);
1403
1404         if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
1405                 EXT4_ERROR_INODE(child->d_inode,
1406                                  "bad parent inode number: %u", ino);
1407                 return ERR_PTR(-EIO);
1408         }
1409
1410         return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));
1411 }
1412
1413 #define S_SHIFT 12
1414 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
1415         [S_IFREG >> S_SHIFT]    = EXT4_FT_REG_FILE,
1416         [S_IFDIR >> S_SHIFT]    = EXT4_FT_DIR,
1417         [S_IFCHR >> S_SHIFT]    = EXT4_FT_CHRDEV,
1418         [S_IFBLK >> S_SHIFT]    = EXT4_FT_BLKDEV,
1419         [S_IFIFO >> S_SHIFT]    = EXT4_FT_FIFO,
1420         [S_IFSOCK >> S_SHIFT]   = EXT4_FT_SOCK,
1421         [S_IFLNK >> S_SHIFT]    = EXT4_FT_SYMLINK,
1422 };
1423
1424 static inline void ext4_set_de_type(struct super_block *sb,
1425                                 struct ext4_dir_entry_2 *de,
1426                                 umode_t mode) {
1427         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
1428                 de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
1429 }
1430
1431 /*
1432  * Move count entries from end of map between two memory locations.
1433  * Returns pointer to last entry moved.
1434  */
1435 static struct ext4_dir_entry_2 *
1436 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1437                 unsigned blocksize)
1438 {
1439         unsigned rec_len = 0;
1440
1441         while (count--) {
1442                 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1443                                                 (from + (map->offs<<2));
1444                 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1445                 memcpy (to, de, rec_len);
1446                 ((struct ext4_dir_entry_2 *) to)->rec_len =
1447                                 ext4_rec_len_to_disk(rec_len, blocksize);
1448                 de->inode = 0;
1449                 map++;
1450                 to += rec_len;
1451         }
1452         return (struct ext4_dir_entry_2 *) (to - rec_len);
1453 }
1454
1455 /*
1456  * Compact each dir entry in the range to the minimal rec_len.
1457  * Returns pointer to last entry in range.
1458  */
1459 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1460 {
1461         struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1462         unsigned rec_len = 0;
1463
1464         prev = to = de;
1465         while ((char*)de < base + blocksize) {
1466                 next = ext4_next_entry(de, blocksize);
1467                 if (de->inode && de->name_len) {
1468                         rec_len = EXT4_DIR_REC_LEN(de->name_len);
1469                         if (de > to)
1470                                 memmove(to, de, rec_len);
1471                         to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1472                         prev = to;
1473                         to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1474                 }
1475                 de = next;
1476         }
1477         return prev;
1478 }
1479
1480 /*
1481  * Split a full leaf block to make room for a new dir entry.
1482  * Allocate a new block, and move entries so that they are approx. equally full.
1483  * Returns pointer to de in block into which the new entry will be inserted.
1484  */
1485 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1486                         struct buffer_head **bh,struct dx_frame *frame,
1487                         struct dx_hash_info *hinfo, int *error)
1488 {
1489         unsigned blocksize = dir->i_sb->s_blocksize;
1490         unsigned count, continued;
1491         struct buffer_head *bh2;
1492         ext4_lblk_t newblock;
1493         u32 hash2;
1494         struct dx_map_entry *map;
1495         char *data1 = (*bh)->b_data, *data2;
1496         unsigned split, move, size;
1497         struct ext4_dir_entry_2 *de = NULL, *de2;
1498         struct ext4_dir_entry_tail *t;
1499         int     csum_size = 0;
1500         int     err = 0, i;
1501
1502         if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
1503                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1504                 csum_size = sizeof(struct ext4_dir_entry_tail);
1505
1506         bh2 = ext4_append (handle, dir, &newblock, &err);
1507         if (!(bh2)) {
1508                 brelse(*bh);
1509                 *bh = NULL;
1510                 goto errout;
1511         }
1512
1513         BUFFER_TRACE(*bh, "get_write_access");
1514         err = ext4_journal_get_write_access(handle, *bh);
1515         if (err)
1516                 goto journal_error;
1517
1518         BUFFER_TRACE(frame->bh, "get_write_access");
1519         err = ext4_journal_get_write_access(handle, frame->bh);
1520         if (err)
1521                 goto journal_error;
1522
1523         data2 = bh2->b_data;
1524
1525         /* create map in the end of data2 block */
1526         map = (struct dx_map_entry *) (data2 + blocksize);
1527         count = dx_make_map((struct ext4_dir_entry_2 *) data1,
1528                              blocksize, hinfo, map);
1529         map -= count;
1530         dx_sort_map(map, count);
1531         /* Split the existing block in the middle, size-wise */
1532         size = 0;
1533         move = 0;
1534         for (i = count-1; i >= 0; i--) {
1535                 /* is more than half of this entry in 2nd half of the block? */
1536                 if (size + map[i].size/2 > blocksize/2)
1537                         break;
1538                 size += map[i].size;
1539                 move++;
1540         }
1541         /* map index at which we will split */
1542         split = count - move;
1543         hash2 = map[split].hash;
1544         continued = hash2 == map[split - 1].hash;
1545         dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1546                         (unsigned long)dx_get_block(frame->at),
1547                                         hash2, split, count-split));
1548
1549         /* Fancy dance to stay within two buffers */
1550         de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
1551         de = dx_pack_dirents(data1, blocksize);
1552         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1553                                            (char *) de,
1554                                            blocksize);
1555         de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1556                                             (char *) de2,
1557                                             blocksize);
1558         if (csum_size) {
1559                 t = EXT4_DIRENT_TAIL(data2, blocksize);
1560                 initialize_dirent_tail(t, blocksize);
1561
1562                 t = EXT4_DIRENT_TAIL(data1, blocksize);
1563                 initialize_dirent_tail(t, blocksize);
1564         }
1565
1566         dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
1567         dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
1568
1569         /* Which block gets the new entry? */
1570         if (hinfo->hash >= hash2)
1571         {
1572                 swap(*bh, bh2);
1573                 de = de2;
1574         }
1575         dx_insert_block(frame, hash2 + continued, newblock);
1576         err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1577         if (err)
1578                 goto journal_error;
1579         err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1580         if (err)
1581                 goto journal_error;
1582         brelse(bh2);
1583         dxtrace(dx_show_index("frame", frame->entries));
1584         return de;
1585
1586 journal_error:
1587         brelse(*bh);
1588         brelse(bh2);
1589         *bh = NULL;
1590         ext4_std_error(dir->i_sb, err);
1591 errout:
1592         *error = err;
1593         return NULL;
1594 }
1595
1596 /*
1597  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1598  * it points to a directory entry which is guaranteed to be large
1599  * enough for new directory entry.  If de is NULL, then
1600  * add_dirent_to_buf will attempt search the directory block for
1601  * space.  It will return -ENOSPC if no space is available, and -EIO
1602  * and -EEXIST if directory entry already exists.
1603  */
1604 static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1605                              struct inode *inode, struct ext4_dir_entry_2 *de,
1606                              struct buffer_head *bh)
1607 {
1608         struct inode    *dir = dentry->d_parent->d_inode;
1609         const char      *name = dentry->d_name.name;
1610         int             namelen = dentry->d_name.len;
1611         unsigned int    offset = 0;
1612         unsigned int    blocksize = dir->i_sb->s_blocksize;
1613         unsigned short  reclen;
1614         int             nlen, rlen, err;
1615         char            *top;
1616         int             csum_size = 0;
1617
1618         if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
1619                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1620                 csum_size = sizeof(struct ext4_dir_entry_tail);
1621
1622         reclen = EXT4_DIR_REC_LEN(namelen);
1623         if (!de) {
1624                 de = (struct ext4_dir_entry_2 *)bh->b_data;
1625                 top = bh->b_data + (blocksize - csum_size) - reclen;
1626                 while ((char *) de <= top) {
1627                         if (ext4_check_dir_entry(dir, NULL, de, bh, offset))
1628                                 return -EIO;
1629                         if (ext4_match(namelen, name, de))
1630                                 return -EEXIST;
1631                         nlen = EXT4_DIR_REC_LEN(de->name_len);
1632                         rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1633                         if ((de->inode? rlen - nlen: rlen) >= reclen)
1634                                 break;
1635                         de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1636                         offset += rlen;
1637                 }
1638                 if ((char *) de > top)
1639                         return -ENOSPC;
1640         }
1641         BUFFER_TRACE(bh, "get_write_access");
1642         err = ext4_journal_get_write_access(handle, bh);
1643         if (err) {
1644                 ext4_std_error(dir->i_sb, err);
1645                 return err;
1646         }
1647
1648         /* By now the buffer is marked for journaling */
1649         nlen = EXT4_DIR_REC_LEN(de->name_len);
1650         rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1651         if (de->inode) {
1652                 struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen);
1653                 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, blocksize);
1654                 de->rec_len = ext4_rec_len_to_disk(nlen, blocksize);
1655                 de = de1;
1656         }
1657         de->file_type = EXT4_FT_UNKNOWN;
1658         de->inode = cpu_to_le32(inode->i_ino);
1659         ext4_set_de_type(dir->i_sb, de, inode->i_mode);
1660         de->name_len = namelen;
1661         memcpy(de->name, name, namelen);
1662         /*
1663          * XXX shouldn't update any times until successful
1664          * completion of syscall, but too many callers depend
1665          * on this.
1666          *
1667          * XXX similarly, too many callers depend on
1668          * ext4_new_inode() setting the times, but error
1669          * recovery deletes the inode, so the worst that can
1670          * happen is that the times are slightly out of date
1671          * and/or different from the directory change time.
1672          */
1673         dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1674         ext4_update_dx_flag(dir);
1675         dir->i_version++;
1676         ext4_mark_inode_dirty(handle, dir);
1677         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1678         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
1679         if (err)
1680                 ext4_std_error(dir->i_sb, err);
1681         return 0;
1682 }
1683
1684 /*
1685  * This converts a one block unindexed directory to a 3 block indexed
1686  * directory, and adds the dentry to the indexed directory.
1687  */
1688 static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
1689                             struct inode *inode, struct buffer_head *bh)
1690 {
1691         struct inode    *dir = dentry->d_parent->d_inode;
1692         const char      *name = dentry->d_name.name;
1693         int             namelen = dentry->d_name.len;
1694         struct buffer_head *bh2;
1695         struct dx_root  *root;
1696         struct dx_frame frames[2], *frame;
1697         struct dx_entry *entries;
1698         struct ext4_dir_entry_2 *de, *de2;
1699         struct ext4_dir_entry_tail *t;
1700         char            *data1, *top;
1701         unsigned        len;
1702         int             retval;
1703         unsigned        blocksize;
1704         struct dx_hash_info hinfo;
1705         ext4_lblk_t  block;
1706         struct fake_dirent *fde;
1707         int             csum_size = 0;
1708
1709         if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
1710                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1711                 csum_size = sizeof(struct ext4_dir_entry_tail);
1712
1713         blocksize =  dir->i_sb->s_blocksize;
1714         dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1715         retval = ext4_journal_get_write_access(handle, bh);
1716         if (retval) {
1717                 ext4_std_error(dir->i_sb, retval);
1718                 brelse(bh);
1719                 return retval;
1720         }
1721         root = (struct dx_root *) bh->b_data;
1722
1723         /* The 0th block becomes the root, move the dirents out */
1724         fde = &root->dotdot;
1725         de = (struct ext4_dir_entry_2 *)((char *)fde +
1726                 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1727         if ((char *) de >= (((char *) root) + blocksize)) {
1728                 EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1729                 brelse(bh);
1730                 return -EIO;
1731         }
1732         len = ((char *) root) + (blocksize - csum_size) - (char *) de;
1733
1734         /* Allocate new block for the 0th block's dirents */
1735         bh2 = ext4_append(handle, dir, &block, &retval);
1736         if (!(bh2)) {
1737                 brelse(bh);
1738                 return retval;
1739         }
1740         ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
1741         data1 = bh2->b_data;
1742
1743         memcpy (data1, de, len);
1744         de = (struct ext4_dir_entry_2 *) data1;
1745         top = data1 + len;
1746         while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1747                 de = de2;
1748         de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1749                                            (char *) de,
1750                                            blocksize);
1751
1752         if (csum_size) {
1753                 t = EXT4_DIRENT_TAIL(data1, blocksize);
1754                 initialize_dirent_tail(t, blocksize);
1755         }
1756
1757         /* Initialize the root; the dot dirents already exist */
1758         de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1759         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1760                                            blocksize);
1761         memset (&root->info, 0, sizeof(root->info));
1762         root->info.info_length = sizeof(root->info);
1763         root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1764         entries = root->entries;
1765         dx_set_block(entries, 1);
1766         dx_set_count(entries, 1);
1767         dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
1768
1769         /* Initialize as for dx_probe */
1770         hinfo.hash_version = root->info.hash_version;
1771         if (hinfo.hash_version <= DX_HASH_TEA)
1772                 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
1773         hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1774         ext4fs_dirhash(name, namelen, &hinfo);
1775         frame = frames;
1776         frame->entries = entries;
1777         frame->at = entries;
1778         frame->bh = bh;
1779         bh = bh2;
1780
1781         ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1782         ext4_handle_dirty_dirent_node(handle, dir, bh);
1783
1784         de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
1785         if (!de) {
1786                 /*
1787                  * Even if the block split failed, we have to properly write
1788                  * out all the changes we did so far. Otherwise we can end up
1789                  * with corrupted filesystem.
1790                  */
1791                 ext4_mark_inode_dirty(handle, dir);
1792                 dx_release(frames);
1793                 return retval;
1794         }
1795         dx_release(frames);
1796
1797         retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1798         brelse(bh);
1799         return retval;
1800 }
1801
1802 /*
1803  *      ext4_add_entry()
1804  *
1805  * adds a file entry to the specified directory, using the same
1806  * semantics as ext4_find_entry(). It returns NULL if it failed.
1807  *
1808  * NOTE!! The inode part of 'de' is left at 0 - which means you
1809  * may not sleep between calling this and putting something into
1810  * the entry, as someone else might have used it while you slept.
1811  */
1812 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
1813                           struct inode *inode)
1814 {
1815         struct inode *dir = dentry->d_parent->d_inode;
1816         struct buffer_head *bh;
1817         struct ext4_dir_entry_2 *de;
1818         struct ext4_dir_entry_tail *t;
1819         struct super_block *sb;
1820         int     retval;
1821         int     dx_fallback=0;
1822         unsigned blocksize;
1823         ext4_lblk_t block, blocks;
1824         int     csum_size = 0;
1825
1826         if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
1827                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1828                 csum_size = sizeof(struct ext4_dir_entry_tail);
1829
1830         sb = dir->i_sb;
1831         blocksize = sb->s_blocksize;
1832         if (!dentry->d_name.len)
1833                 return -EINVAL;
1834         if (is_dx(dir)) {
1835                 retval = ext4_dx_add_entry(handle, dentry, inode);
1836                 if (!retval || (retval != ERR_BAD_DX_DIR))
1837                         return retval;
1838                 ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
1839                 dx_fallback++;
1840                 ext4_mark_inode_dirty(handle, dir);
1841         }
1842         blocks = dir->i_size >> sb->s_blocksize_bits;
1843         for (block = 0; block < blocks; block++) {
1844                 if (!(bh = ext4_bread(handle, dir, block, 0, &retval))) {
1845                         if (!retval) {
1846                                 retval = -EIO;
1847                                 ext4_error(inode->i_sb,
1848                                            "Directory hole detected on inode %lu\n",
1849                                            inode->i_ino);
1850                         }
1851                         return retval;
1852                 }
1853                 if (!buffer_verified(bh) &&
1854                     !ext4_dirent_csum_verify(dir,
1855                                 (struct ext4_dir_entry *)bh->b_data))
1856                         return -EIO;
1857                 set_buffer_verified(bh);
1858                 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1859                 if (retval != -ENOSPC) {
1860                         brelse(bh);
1861                         return retval;
1862                 }
1863
1864                 if (blocks == 1 && !dx_fallback &&
1865                     EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
1866                         return make_indexed_dir(handle, dentry, inode, bh);
1867                 brelse(bh);
1868         }
1869         bh = ext4_append(handle, dir, &block, &retval);
1870         if (!bh)
1871                 return retval;
1872         de = (struct ext4_dir_entry_2 *) bh->b_data;
1873         de->inode = 0;
1874         de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
1875
1876         if (csum_size) {
1877                 t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
1878                 initialize_dirent_tail(t, blocksize);
1879         }
1880
1881         retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
1882         brelse(bh);
1883         if (retval == 0)
1884                 ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
1885         return retval;
1886 }
1887
1888 /*
1889  * Returns 0 for success, or a negative error value
1890  */
1891 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
1892                              struct inode *inode)
1893 {
1894         struct dx_frame frames[2], *frame;
1895         struct dx_entry *entries, *at;
1896         struct dx_hash_info hinfo;
1897         struct buffer_head *bh;
1898         struct inode *dir = dentry->d_parent->d_inode;
1899         struct super_block *sb = dir->i_sb;
1900         struct ext4_dir_entry_2 *de;
1901         int err;
1902
1903         frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, &err);
1904         if (!frame)
1905                 return err;
1906         entries = frame->entries;
1907         at = frame->at;
1908
1909         if (!(bh = ext4_bread(handle, dir, dx_get_block(frame->at), 0, &err))) {
1910                 if (!err) {
1911                         err = -EIO;
1912                         ext4_error(dir->i_sb,
1913                                    "Directory hole detected on inode %lu\n",
1914                                    dir->i_ino);
1915                 }
1916                 goto cleanup;
1917         }
1918
1919         if (!buffer_verified(bh) &&
1920             !ext4_dirent_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data))
1921                 goto journal_error;
1922         set_buffer_verified(bh);
1923
1924         BUFFER_TRACE(bh, "get_write_access");
1925         err = ext4_journal_get_write_access(handle, bh);
1926         if (err)
1927                 goto journal_error;
1928
1929         err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1930         if (err != -ENOSPC)
1931                 goto cleanup;
1932
1933         /* Block full, should compress but for now just split */
1934         dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
1935                        dx_get_count(entries), dx_get_limit(entries)));
1936         /* Need to split index? */
1937         if (dx_get_count(entries) == dx_get_limit(entries)) {
1938                 ext4_lblk_t newblock;
1939                 unsigned icount = dx_get_count(entries);
1940                 int levels = frame - frames;
1941                 struct dx_entry *entries2;
1942                 struct dx_node *node2;
1943                 struct buffer_head *bh2;
1944
1945                 if (levels && (dx_get_count(frames->entries) ==
1946                                dx_get_limit(frames->entries))) {
1947                         ext4_warning(sb, "Directory index full!");
1948                         err = -ENOSPC;
1949                         goto cleanup;
1950                 }
1951                 bh2 = ext4_append (handle, dir, &newblock, &err);
1952                 if (!(bh2))
1953                         goto cleanup;
1954                 node2 = (struct dx_node *)(bh2->b_data);
1955                 entries2 = node2->entries;
1956                 memset(&node2->fake, 0, sizeof(struct fake_dirent));
1957                 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
1958                                                            sb->s_blocksize);
1959                 BUFFER_TRACE(frame->bh, "get_write_access");
1960                 err = ext4_journal_get_write_access(handle, frame->bh);
1961                 if (err)
1962                         goto journal_error;
1963                 if (levels) {
1964                         unsigned icount1 = icount/2, icount2 = icount - icount1;
1965                         unsigned hash2 = dx_get_hash(entries + icount1);
1966                         dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
1967                                        icount1, icount2));
1968
1969                         BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
1970                         err = ext4_journal_get_write_access(handle,
1971                                                              frames[0].bh);
1972                         if (err)
1973                                 goto journal_error;
1974
1975                         memcpy((char *) entries2, (char *) (entries + icount1),
1976                                icount2 * sizeof(struct dx_entry));
1977                         dx_set_count(entries, icount1);
1978                         dx_set_count(entries2, icount2);
1979                         dx_set_limit(entries2, dx_node_limit(dir));
1980
1981                         /* Which index block gets the new entry? */
1982                         if (at - entries >= icount1) {
1983                                 frame->at = at = at - entries - icount1 + entries2;
1984                                 frame->entries = entries = entries2;
1985                                 swap(frame->bh, bh2);
1986                         }
1987                         dx_insert_block(frames + 0, hash2, newblock);
1988                         dxtrace(dx_show_index("node", frames[1].entries));
1989                         dxtrace(dx_show_index("node",
1990                                ((struct dx_node *) bh2->b_data)->entries));
1991                         err = ext4_handle_dirty_dx_node(handle, dir, bh2);
1992                         if (err)
1993                                 goto journal_error;
1994                         brelse (bh2);
1995                 } else {
1996                         dxtrace(printk(KERN_DEBUG
1997                                        "Creating second level index...\n"));
1998                         memcpy((char *) entries2, (char *) entries,
1999                                icount * sizeof(struct dx_entry));
2000                         dx_set_limit(entries2, dx_node_limit(dir));
2001
2002                         /* Set up root */
2003                         dx_set_count(entries, 1);
2004                         dx_set_block(entries + 0, newblock);
2005                         ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
2006
2007                         /* Add new access path frame */
2008                         frame = frames + 1;
2009                         frame->at = at = at - entries + entries2;
2010                         frame->entries = entries = entries2;
2011                         frame->bh = bh2;
2012                         err = ext4_journal_get_write_access(handle,
2013                                                              frame->bh);
2014                         if (err)
2015                                 goto journal_error;
2016                 }
2017                 err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
2018                 if (err) {
2019                         ext4_std_error(inode->i_sb, err);
2020                         goto cleanup;
2021                 }
2022         }
2023         de = do_split(handle, dir, &bh, frame, &hinfo, &err);
2024         if (!de)
2025                 goto cleanup;
2026         err = add_dirent_to_buf(handle, dentry, inode, de, bh);
2027         goto cleanup;
2028
2029 journal_error:
2030         ext4_std_error(dir->i_sb, err);
2031 cleanup:
2032         if (bh)
2033                 brelse(bh);
2034         dx_release(frames);
2035         return err;
2036 }
2037
2038 /*
2039  * ext4_delete_entry deletes a directory entry by merging it with the
2040  * previous entry
2041  */
2042 static int ext4_delete_entry(handle_t *handle,
2043                              struct inode *dir,
2044                              struct ext4_dir_entry_2 *de_del,
2045                              struct buffer_head *bh)
2046 {
2047         struct ext4_dir_entry_2 *de, *pde;
2048         unsigned int blocksize = dir->i_sb->s_blocksize;
2049         int csum_size = 0;
2050         int i, err;
2051
2052         if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
2053                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
2054                 csum_size = sizeof(struct ext4_dir_entry_tail);
2055
2056         i = 0;
2057         pde = NULL;
2058         de = (struct ext4_dir_entry_2 *) bh->b_data;
2059         while (i < bh->b_size - csum_size) {
2060                 if (ext4_check_dir_entry(dir, NULL, de, bh, i))
2061                         return -EIO;
2062                 if (de == de_del)  {
2063                         BUFFER_TRACE(bh, "get_write_access");
2064                         err = ext4_journal_get_write_access(handle, bh);
2065                         if (unlikely(err)) {
2066                                 ext4_std_error(dir->i_sb, err);
2067                                 return err;
2068                         }
2069                         if (pde)
2070                                 pde->rec_len = ext4_rec_len_to_disk(
2071                                         ext4_rec_len_from_disk(pde->rec_len,
2072                                                                blocksize) +
2073                                         ext4_rec_len_from_disk(de->rec_len,
2074                                                                blocksize),
2075                                         blocksize);
2076                         else
2077                                 de->inode = 0;
2078                         dir->i_version++;
2079                         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2080                         err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2081                         if (unlikely(err)) {
2082                                 ext4_std_error(dir->i_sb, err);
2083                                 return err;
2084                         }
2085                         return 0;
2086                 }
2087                 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2088                 pde = de;
2089                 de = ext4_next_entry(de, blocksize);
2090         }
2091         return -ENOENT;
2092 }
2093
2094 /*
2095  * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
2096  * since this indicates that nlinks count was previously 1.
2097  */
2098 static void ext4_inc_count(handle_t *handle, struct inode *inode)
2099 {
2100         inc_nlink(inode);
2101         if (is_dx(inode) && inode->i_nlink > 1) {
2102                 /* limit is 16-bit i_links_count */
2103                 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
2104                         set_nlink(inode, 1);
2105                         EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
2106                                               EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
2107                 }
2108         }
2109 }
2110
2111 /*
2112  * If a directory had nlink == 1, then we should let it be 1. This indicates
2113  * directory has >EXT4_LINK_MAX subdirs.
2114  */
2115 static void ext4_dec_count(handle_t *handle, struct inode *inode)
2116 {
2117         if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2118                 drop_nlink(inode);
2119 }
2120
2121
2122 static int ext4_add_nondir(handle_t *handle,
2123                 struct dentry *dentry, struct inode *inode)
2124 {
2125         int err = ext4_add_entry(handle, dentry, inode);
2126         if (!err) {
2127                 ext4_mark_inode_dirty(handle, inode);
2128                 unlock_new_inode(inode);
2129                 d_instantiate(dentry, inode);
2130                 return 0;
2131         }
2132         drop_nlink(inode);
2133         unlock_new_inode(inode);
2134         iput(inode);
2135         return err;
2136 }
2137
2138 /*
2139  * By the time this is called, we already have created
2140  * the directory cache entry for the new file, but it
2141  * is so far negative - it has no inode.
2142  *
2143  * If the create succeeds, we fill in the inode information
2144  * with d_instantiate().
2145  */
2146 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2147                        bool excl)
2148 {
2149         handle_t *handle;
2150         struct inode *inode;
2151         int err, retries = 0;
2152
2153         dquot_initialize(dir);
2154
2155 retry:
2156         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2157                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2158                                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
2159         if (IS_ERR(handle))
2160                 return PTR_ERR(handle);
2161
2162         if (IS_DIRSYNC(dir))
2163                 ext4_handle_sync(handle);
2164
2165         inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0, NULL);
2166         err = PTR_ERR(inode);
2167         if (!IS_ERR(inode)) {
2168                 inode->i_op = &ext4_file_inode_operations;
2169                 inode->i_fop = &ext4_file_operations;
2170                 ext4_set_aops(inode);
2171                 err = ext4_add_nondir(handle, dentry, inode);
2172         }
2173         ext4_journal_stop(handle);
2174         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2175                 goto retry;
2176         return err;
2177 }
2178
2179 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2180                       umode_t mode, dev_t rdev)
2181 {
2182         handle_t *handle;
2183         struct inode *inode;
2184         int err, retries = 0;
2185
2186         if (!new_valid_dev(rdev))
2187                 return -EINVAL;
2188
2189         dquot_initialize(dir);
2190
2191 retry:
2192         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2193                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2194                                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
2195         if (IS_ERR(handle))
2196                 return PTR_ERR(handle);
2197
2198         if (IS_DIRSYNC(dir))
2199                 ext4_handle_sync(handle);
2200
2201         inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0, NULL);
2202         err = PTR_ERR(inode);
2203         if (!IS_ERR(inode)) {
2204                 init_special_inode(inode, inode->i_mode, rdev);
2205                 inode->i_op = &ext4_special_inode_operations;
2206                 err = ext4_add_nondir(handle, dentry, inode);
2207         }
2208         ext4_journal_stop(handle);
2209         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2210                 goto retry;
2211         return err;
2212 }
2213
2214 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2215 {
2216         handle_t *handle;
2217         struct inode *inode;
2218         struct buffer_head *dir_block = NULL;
2219         struct ext4_dir_entry_2 *de;
2220         struct ext4_dir_entry_tail *t;
2221         unsigned int blocksize = dir->i_sb->s_blocksize;
2222         int csum_size = 0;
2223         int err, retries = 0;
2224
2225         if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
2226                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
2227                 csum_size = sizeof(struct ext4_dir_entry_tail);
2228
2229         if (EXT4_DIR_LINK_MAX(dir))
2230                 return -EMLINK;
2231
2232         dquot_initialize(dir);
2233
2234 retry:
2235         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2236                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2237                                         EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
2238         if (IS_ERR(handle))
2239                 return PTR_ERR(handle);
2240
2241         if (IS_DIRSYNC(dir))
2242                 ext4_handle_sync(handle);
2243
2244         inode = ext4_new_inode(handle, dir, S_IFDIR | mode,
2245                                &dentry->d_name, 0, NULL);
2246         err = PTR_ERR(inode);
2247         if (IS_ERR(inode))
2248                 goto out_stop;
2249
2250         inode->i_op = &ext4_dir_inode_operations;
2251         inode->i_fop = &ext4_dir_operations;
2252         inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
2253         if (!(dir_block = ext4_bread(handle, inode, 0, 1, &err))) {
2254                 if (!err) {
2255                         err = -EIO;
2256                         ext4_error(inode->i_sb,
2257                                    "Directory hole detected on inode %lu\n",
2258                                    inode->i_ino);
2259                 }
2260                 goto out_clear_inode;
2261         }
2262         BUFFER_TRACE(dir_block, "get_write_access");
2263         err = ext4_journal_get_write_access(handle, dir_block);
2264         if (err)
2265                 goto out_clear_inode;
2266         de = (struct ext4_dir_entry_2 *) dir_block->b_data;
2267         de->inode = cpu_to_le32(inode->i_ino);
2268         de->name_len = 1;
2269         de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2270                                            blocksize);
2271         strcpy(de->name, ".");
2272         ext4_set_de_type(dir->i_sb, de, S_IFDIR);
2273         de = ext4_next_entry(de, blocksize);
2274         de->inode = cpu_to_le32(dir->i_ino);
2275         de->rec_len = ext4_rec_len_to_disk(blocksize -
2276                                            (csum_size + EXT4_DIR_REC_LEN(1)),
2277                                            blocksize);
2278         de->name_len = 2;
2279         strcpy(de->name, "..");
2280         ext4_set_de_type(dir->i_sb, de, S_IFDIR);
2281         set_nlink(inode, 2);
2282
2283         if (csum_size) {
2284                 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2285                 initialize_dirent_tail(t, blocksize);
2286         }
2287
2288         BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2289         err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2290         if (err)
2291                 goto out_clear_inode;
2292         set_buffer_verified(dir_block);
2293         err = ext4_mark_inode_dirty(handle, inode);
2294         if (!err)
2295                 err = ext4_add_entry(handle, dentry, inode);
2296         if (err) {
2297 out_clear_inode:
2298                 clear_nlink(inode);
2299                 unlock_new_inode(inode);
2300                 ext4_mark_inode_dirty(handle, inode);
2301                 iput(inode);
2302                 goto out_stop;
2303         }
2304         ext4_inc_count(handle, dir);
2305         ext4_update_dx_flag(dir);
2306         err = ext4_mark_inode_dirty(handle, dir);
2307         if (err)
2308                 goto out_clear_inode;
2309         unlock_new_inode(inode);
2310         d_instantiate(dentry, inode);
2311 out_stop:
2312         brelse(dir_block);
2313         ext4_journal_stop(handle);
2314         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2315                 goto retry;
2316         return err;
2317 }
2318
2319 /*
2320  * routine to check that the specified directory is empty (for rmdir)
2321  */
2322 static int empty_dir(struct inode *inode)
2323 {
2324         unsigned int offset;
2325         struct buffer_head *bh;
2326         struct ext4_dir_entry_2 *de, *de1;
2327         struct super_block *sb;
2328         int err = 0;
2329
2330         sb = inode->i_sb;
2331         if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) ||
2332             !(bh = ext4_bread(NULL, inode, 0, 0, &err))) {
2333                 if (err)
2334                         EXT4_ERROR_INODE(inode,
2335                                 "error %d reading directory lblock 0", err);
2336                 else
2337                         ext4_warning(inode->i_sb,
2338                                      "bad directory (dir #%lu) - no data block",
2339                                      inode->i_ino);
2340                 return 1;
2341         }
2342         if (!buffer_verified(bh) &&
2343             !ext4_dirent_csum_verify(inode,
2344                         (struct ext4_dir_entry *)bh->b_data)) {
2345                 EXT4_ERROR_INODE(inode, "checksum error reading directory "
2346                                  "lblock 0");
2347                 return -EIO;
2348         }
2349         set_buffer_verified(bh);
2350         de = (struct ext4_dir_entry_2 *) bh->b_data;
2351         de1 = ext4_next_entry(de, sb->s_blocksize);
2352         if (le32_to_cpu(de->inode) != inode->i_ino ||
2353                         !le32_to_cpu(de1->inode) ||
2354                         strcmp(".", de->name) ||
2355                         strcmp("..", de1->name)) {
2356                 ext4_warning(inode->i_sb,
2357                              "bad directory (dir #%lu) - no `.' or `..'",
2358                              inode->i_ino);
2359                 brelse(bh);
2360                 return 1;
2361         }
2362         offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2363                  ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2364         de = ext4_next_entry(de1, sb->s_blocksize);
2365         while (offset < inode->i_size) {
2366                 if (!bh ||
2367                     (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2368                         unsigned int lblock;
2369                         err = 0;
2370                         brelse(bh);
2371                         lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2372                         bh = ext4_bread(NULL, inode, lblock, 0, &err);
2373                         if (!bh) {
2374                                 if (err)
2375                                         EXT4_ERROR_INODE(inode,
2376                                                 "error %d reading directory "
2377                                                 "lblock %u", err, lblock);
2378                                 else
2379                                         ext4_warning(inode->i_sb,
2380                                                 "bad directory (dir #%lu) - no data block",
2381                                                 inode->i_ino);
2382
2383                                 offset += sb->s_blocksize;
2384                                 continue;
2385                         }
2386                         if (!buffer_verified(bh) &&
2387                             !ext4_dirent_csum_verify(inode,
2388                                         (struct ext4_dir_entry *)bh->b_data)) {
2389                                 EXT4_ERROR_INODE(inode, "checksum error "
2390                                                  "reading directory lblock 0");
2391                                 return -EIO;
2392                         }
2393                         set_buffer_verified(bh);
2394                         de = (struct ext4_dir_entry_2 *) bh->b_data;
2395                 }
2396                 if (ext4_check_dir_entry(inode, NULL, de, bh, offset)) {
2397                         de = (struct ext4_dir_entry_2 *)(bh->b_data +
2398                                                          sb->s_blocksize);
2399                         offset = (offset | (sb->s_blocksize - 1)) + 1;
2400                         continue;
2401                 }
2402                 if (le32_to_cpu(de->inode)) {
2403                         brelse(bh);
2404                         return 0;
2405                 }
2406                 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2407                 de = ext4_next_entry(de, sb->s_blocksize);
2408         }
2409         brelse(bh);
2410         return 1;
2411 }
2412
2413 /* ext4_orphan_add() links an unlinked or truncated inode into a list of
2414  * such inodes, starting at the superblock, in case we crash before the
2415  * file is closed/deleted, or in case the inode truncate spans multiple
2416  * transactions and the last transaction is not recovered after a crash.
2417  *
2418  * At filesystem recovery time, we walk this list deleting unlinked
2419  * inodes and truncating linked inodes in ext4_orphan_cleanup().
2420  */
2421 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2422 {
2423         struct super_block *sb = inode->i_sb;
2424         struct ext4_iloc iloc;
2425         int err = 0, rc;
2426
2427         if (!EXT4_SB(sb)->s_journal)
2428                 return 0;
2429
2430         mutex_lock(&EXT4_SB(sb)->s_orphan_lock);
2431         if (!list_empty(&EXT4_I(inode)->i_orphan))
2432                 goto out_unlock;
2433
2434         /*
2435          * Orphan handling is only valid for files with data blocks
2436          * being truncated, or files being unlinked. Note that we either
2437          * hold i_mutex, or the inode can not be referenced from outside,
2438          * so i_nlink should not be bumped due to race
2439          */
2440         J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2441                   S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2442
2443         BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
2444         err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
2445         if (err)
2446                 goto out_unlock;
2447
2448         err = ext4_reserve_inode_write(handle, inode, &iloc);
2449         if (err)
2450                 goto out_unlock;
2451         /*
2452          * Due to previous errors inode may be already a part of on-disk
2453          * orphan list. If so skip on-disk list modification.
2454          */
2455         if (NEXT_ORPHAN(inode) && NEXT_ORPHAN(inode) <=
2456                 (le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count)))
2457                         goto mem_insert;
2458
2459         /* Insert this inode at the head of the on-disk orphan list... */
2460         NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
2461         EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2462         err = ext4_handle_dirty_super(handle, sb);
2463         rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2464         if (!err)
2465                 err = rc;
2466
2467         /* Only add to the head of the in-memory list if all the
2468          * previous operations succeeded.  If the orphan_add is going to
2469          * fail (possibly taking the journal offline), we can't risk
2470          * leaving the inode on the orphan list: stray orphan-list
2471          * entries can cause panics at unmount time.
2472          *
2473          * This is safe: on error we're going to ignore the orphan list
2474          * anyway on the next recovery. */
2475 mem_insert:
2476         if (!err)
2477                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2478
2479         jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2480         jbd_debug(4, "orphan inode %lu will point to %d\n",
2481                         inode->i_ino, NEXT_ORPHAN(inode));
2482 out_unlock:
2483         mutex_unlock(&EXT4_SB(sb)->s_orphan_lock);
2484         ext4_std_error(inode->i_sb, err);
2485         return err;
2486 }
2487
2488 /*
2489  * ext4_orphan_del() removes an unlinked or truncated inode from the list
2490  * of such inodes stored on disk, because it is finally being cleaned up.
2491  */
2492 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2493 {
2494         struct list_head *prev;
2495         struct ext4_inode_info *ei = EXT4_I(inode);
2496         struct ext4_sb_info *sbi;
2497         __u32 ino_next;
2498         struct ext4_iloc iloc;
2499         int err = 0;
2500
2501         if (!EXT4_SB(inode->i_sb)->s_journal)
2502                 return 0;
2503
2504         mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2505         if (list_empty(&ei->i_orphan))
2506                 goto out;
2507
2508         ino_next = NEXT_ORPHAN(inode);
2509         prev = ei->i_orphan.prev;
2510         sbi = EXT4_SB(inode->i_sb);
2511
2512         jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2513
2514         list_del_init(&ei->i_orphan);
2515
2516         /* If we're on an error path, we may not have a valid
2517          * transaction handle with which to update the orphan list on
2518          * disk, but we still need to remove the inode from the linked
2519          * list in memory. */
2520         if (!handle)
2521                 goto out;
2522
2523         err = ext4_reserve_inode_write(handle, inode, &iloc);
2524         if (err)
2525                 goto out_err;
2526
2527         if (prev == &sbi->s_orphan) {
2528                 jbd_debug(4, "superblock will point to %u\n", ino_next);
2529                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2530                 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2531                 if (err)
2532                         goto out_brelse;
2533                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2534                 err = ext4_handle_dirty_super(handle, inode->i_sb);
2535         } else {
2536                 struct ext4_iloc iloc2;
2537                 struct inode *i_prev =
2538                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2539
2540                 jbd_debug(4, "orphan inode %lu will point to %u\n",
2541                           i_prev->i_ino, ino_next);
2542                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2543                 if (err)
2544                         goto out_brelse;
2545                 NEXT_ORPHAN(i_prev) = ino_next;
2546                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2547         }
2548         if (err)
2549                 goto out_brelse;
2550         NEXT_ORPHAN(inode) = 0;
2551         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2552
2553 out_err:
2554         ext4_std_error(inode->i_sb, err);
2555 out:
2556         mutex_unlock(&EXT4_SB(inode->i_sb)->s_orphan_lock);
2557         return err;
2558
2559 out_brelse:
2560         brelse(iloc.bh);
2561         goto out_err;
2562 }
2563
2564 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2565 {
2566         int retval;
2567         struct inode *inode;
2568         struct buffer_head *bh;
2569         struct ext4_dir_entry_2 *de;
2570         handle_t *handle;
2571
2572         /* Initialize quotas before so that eventual writes go in
2573          * separate transaction */
2574         dquot_initialize(dir);
2575         dquot_initialize(dentry->d_inode);
2576
2577         handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2578         if (IS_ERR(handle))
2579                 return PTR_ERR(handle);
2580
2581         retval = -ENOENT;
2582         bh = ext4_find_entry(dir, &dentry->d_name, &de);
2583         if (!bh)
2584                 goto end_rmdir;
2585
2586         if (IS_DIRSYNC(dir))
2587                 ext4_handle_sync(handle);
2588
2589         inode = dentry->d_inode;
2590
2591         retval = -EIO;
2592         if (le32_to_cpu(de->inode) != inode->i_ino)
2593                 goto end_rmdir;
2594
2595         retval = -ENOTEMPTY;
2596         if (!empty_dir(inode))
2597                 goto end_rmdir;
2598
2599         retval = ext4_delete_entry(handle, dir, de, bh);
2600         if (retval)
2601                 goto end_rmdir;
2602         if (!EXT4_DIR_LINK_EMPTY(inode))
2603                 ext4_warning(inode->i_sb,
2604                              "empty directory has too many links (%d)",
2605                              inode->i_nlink);
2606         inode->i_version++;
2607         clear_nlink(inode);
2608         /* There's no need to set i_disksize: the fact that i_nlink is
2609          * zero will ensure that the right thing happens during any
2610          * recovery. */
2611         inode->i_size = 0;
2612         ext4_orphan_add(handle, inode);
2613         inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2614         ext4_mark_inode_dirty(handle, inode);
2615         ext4_dec_count(handle, dir);
2616         ext4_update_dx_flag(dir);
2617         ext4_mark_inode_dirty(handle, dir);
2618
2619 end_rmdir:
2620         ext4_journal_stop(handle);
2621         brelse(bh);
2622         return retval;
2623 }
2624
2625 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2626 {
2627         int retval;
2628         struct inode *inode;
2629         struct buffer_head *bh;
2630         struct ext4_dir_entry_2 *de;
2631         handle_t *handle;
2632
2633         trace_ext4_unlink_enter(dir, dentry);
2634         /* Initialize quotas before so that eventual writes go
2635          * in separate transaction */
2636         dquot_initialize(dir);
2637         dquot_initialize(dentry->d_inode);
2638
2639         handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2640         if (IS_ERR(handle))
2641                 return PTR_ERR(handle);
2642
2643         if (IS_DIRSYNC(dir))
2644                 ext4_handle_sync(handle);
2645
2646         retval = -ENOENT;
2647         bh = ext4_find_entry(dir, &dentry->d_name, &de);
2648         if (!bh)
2649                 goto end_unlink;
2650
2651         inode = dentry->d_inode;
2652
2653         retval = -EIO;
2654         if (le32_to_cpu(de->inode) != inode->i_ino)
2655                 goto end_unlink;
2656
2657         if (!inode->i_nlink) {
2658                 ext4_warning(inode->i_sb,
2659                              "Deleting nonexistent file (%lu), %d",
2660                              inode->i_ino, inode->i_nlink);
2661                 set_nlink(inode, 1);
2662         }
2663         retval = ext4_delete_entry(handle, dir, de, bh);
2664         if (retval)
2665                 goto end_unlink;
2666         dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
2667         ext4_update_dx_flag(dir);
2668         ext4_mark_inode_dirty(handle, dir);
2669         drop_nlink(inode);
2670         if (!inode->i_nlink)
2671                 ext4_orphan_add(handle, inode);
2672         inode->i_ctime = ext4_current_time(inode);
2673         ext4_mark_inode_dirty(handle, inode);
2674         retval = 0;
2675
2676 end_unlink:
2677         ext4_journal_stop(handle);
2678         brelse(bh);
2679         trace_ext4_unlink_exit(dentry, retval);
2680         return retval;
2681 }
2682
2683 static int ext4_symlink(struct inode *dir,
2684                         struct dentry *dentry, const char *symname)
2685 {
2686         handle_t *handle;
2687         struct inode *inode;
2688         int l, err, retries = 0;
2689         int credits;
2690
2691         l = strlen(symname)+1;
2692         if (l > dir->i_sb->s_blocksize)
2693                 return -ENAMETOOLONG;
2694
2695         dquot_initialize(dir);
2696
2697         if (l > EXT4_N_BLOCKS * 4) {
2698                 /*
2699                  * For non-fast symlinks, we just allocate inode and put it on
2700                  * orphan list in the first transaction => we need bitmap,
2701                  * group descriptor, sb, inode block, quota blocks, and
2702                  * possibly selinux xattr blocks.
2703                  */
2704                 credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2705                           EXT4_XATTR_TRANS_BLOCKS;
2706         } else {
2707                 /*
2708                  * Fast symlink. We have to add entry to directory
2709                  * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
2710                  * allocate new inode (bitmap, group descriptor, inode block,
2711                  * quota blocks, sb is already counted in previous macros).
2712                  */
2713                 credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2714                           EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
2715                           EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb);
2716         }
2717 retry:
2718         handle = ext4_journal_start(dir, credits);
2719         if (IS_ERR(handle))
2720                 return PTR_ERR(handle);
2721
2722         if (IS_DIRSYNC(dir))
2723                 ext4_handle_sync(handle);
2724
2725         inode = ext4_new_inode(handle, dir, S_IFLNK|S_IRWXUGO,
2726                                &dentry->d_name, 0, NULL);
2727         err = PTR_ERR(inode);
2728         if (IS_ERR(inode))
2729                 goto out_stop;
2730
2731         if (l > EXT4_N_BLOCKS * 4) {
2732                 inode->i_op = &ext4_symlink_inode_operations;
2733                 ext4_set_aops(inode);
2734                 /*
2735                  * We cannot call page_symlink() with transaction started
2736                  * because it calls into ext4_write_begin() which can wait
2737                  * for transaction commit if we are running out of space
2738                  * and thus we deadlock. So we have to stop transaction now
2739                  * and restart it when symlink contents is written.
2740                  *
2741                  * To keep fs consistent in case of crash, we have to put inode
2742                  * to orphan list in the mean time.
2743                  */
2744                 drop_nlink(inode);
2745                 err = ext4_orphan_add(handle, inode);
2746                 ext4_journal_stop(handle);
2747                 if (err)
2748                         goto err_drop_inode;
2749                 err = __page_symlink(inode, symname, l, 1);
2750                 if (err)
2751                         goto err_drop_inode;
2752                 /*
2753                  * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
2754                  * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
2755                  */
2756                 handle = ext4_journal_start(dir,
2757                                 EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2758                                 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
2759                 if (IS_ERR(handle)) {
2760                         err = PTR_ERR(handle);
2761                         goto err_drop_inode;
2762                 }
2763                 set_nlink(inode, 1);
2764                 err = ext4_orphan_del(handle, inode);
2765                 if (err) {
2766                         ext4_journal_stop(handle);
2767                         clear_nlink(inode);
2768                         goto err_drop_inode;
2769                 }
2770         } else {
2771                 /* clear the extent format for fast symlink */
2772                 ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
2773                 inode->i_op = &ext4_fast_symlink_inode_operations;
2774                 memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
2775                 inode->i_size = l-1;
2776         }
2777         EXT4_I(inode)->i_disksize = inode->i_size;
2778         err = ext4_add_nondir(handle, dentry, inode);
2779 out_stop:
2780         ext4_journal_stop(handle);
2781         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2782                 goto retry;
2783         return err;
2784 err_drop_inode:
2785         unlock_new_inode(inode);
2786         iput(inode);
2787         return err;
2788 }
2789
2790 static int ext4_link(struct dentry *old_dentry,
2791                      struct inode *dir, struct dentry *dentry)
2792 {
2793         handle_t *handle;
2794         struct inode *inode = old_dentry->d_inode;
2795         int err, retries = 0;
2796
2797         if (inode->i_nlink >= EXT4_LINK_MAX)
2798                 return -EMLINK;
2799
2800         dquot_initialize(dir);
2801
2802 retry:
2803         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2804                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS);
2805         if (IS_ERR(handle))
2806                 return PTR_ERR(handle);
2807
2808         if (IS_DIRSYNC(dir))
2809                 ext4_handle_sync(handle);
2810
2811         inode->i_ctime = ext4_current_time(inode);
2812         ext4_inc_count(handle, inode);
2813         ihold(inode);
2814
2815         err = ext4_add_entry(handle, dentry, inode);
2816         if (!err) {
2817                 ext4_mark_inode_dirty(handle, inode);
2818                 d_instantiate(dentry, inode);
2819         } else {
2820                 drop_nlink(inode);
2821                 iput(inode);
2822         }
2823         ext4_journal_stop(handle);
2824         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2825                 goto retry;
2826         return err;
2827 }
2828
2829 #define PARENT_INO(buffer, size) \
2830         (ext4_next_entry((struct ext4_dir_entry_2 *)(buffer), size)->inode)
2831
2832 /*
2833  * Anybody can rename anything with this: the permission checks are left to the
2834  * higher-level routines.
2835  */
2836 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
2837                        struct inode *new_dir, struct dentry *new_dentry)
2838 {
2839         handle_t *handle;
2840         struct inode *old_inode, *new_inode;
2841         struct buffer_head *old_bh, *new_bh, *dir_bh;
2842         struct ext4_dir_entry_2 *old_de, *new_de;
2843         int retval, force_da_alloc = 0;
2844
2845         dquot_initialize(old_dir);
2846         dquot_initialize(new_dir);
2847
2848         old_bh = new_bh = dir_bh = NULL;
2849
2850         /* Initialize quotas before so that eventual writes go
2851          * in separate transaction */
2852         if (new_dentry->d_inode)
2853                 dquot_initialize(new_dentry->d_inode);
2854         handle = ext4_journal_start(old_dir, 2 *
2855                                         EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
2856                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
2857         if (IS_ERR(handle))
2858                 return PTR_ERR(handle);
2859
2860         if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
2861                 ext4_handle_sync(handle);
2862
2863         old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de);
2864         /*
2865          *  Check for inode number is _not_ due to possible IO errors.
2866          *  We might rmdir the source, keep it as pwd of some process
2867          *  and merrily kill the link to whatever was created under the
2868          *  same name. Goodbye sticky bit ;-<
2869          */
2870         old_inode = old_dentry->d_inode;
2871         retval = -ENOENT;
2872         if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
2873                 goto end_rename;
2874
2875         new_inode = new_dentry->d_inode;
2876         new_bh = ext4_find_entry(new_dir, &new_dentry->d_name, &new_de);
2877         if (new_bh) {
2878                 if (!new_inode) {
2879                         brelse(new_bh);
2880                         new_bh = NULL;
2881                 }
2882         }
2883         if (S_ISDIR(old_inode->i_mode)) {
2884                 if (new_inode) {
2885                         retval = -ENOTEMPTY;
2886                         if (!empty_dir(new_inode))
2887                                 goto end_rename;
2888                 }
2889                 retval = -EIO;
2890                 if (!(dir_bh = ext4_bread(handle, old_inode, 0, 0, &retval))) {
2891                         if (!retval) {
2892                                 retval = -EIO;
2893                                 ext4_error(old_inode->i_sb,
2894                                            "Directory hole detected on inode %lu\n",
2895                                            old_inode->i_ino);
2896                         }
2897                         goto end_rename;
2898                 }
2899                 if (!buffer_verified(dir_bh) &&
2900                     !ext4_dirent_csum_verify(old_inode,
2901                                 (struct ext4_dir_entry *)dir_bh->b_data))
2902                         goto end_rename;
2903                 set_buffer_verified(dir_bh);
2904                 if (le32_to_cpu(PARENT_INO(dir_bh->b_data,
2905                                 old_dir->i_sb->s_blocksize)) != old_dir->i_ino)
2906                         goto end_rename;
2907                 retval = -EMLINK;
2908                 if (!new_inode && new_dir != old_dir &&
2909                     EXT4_DIR_LINK_MAX(new_dir))
2910                         goto end_rename;
2911                 BUFFER_TRACE(dir_bh, "get_write_access");
2912                 retval = ext4_journal_get_write_access(handle, dir_bh);
2913                 if (retval)
2914                         goto end_rename;
2915         }
2916         if (!new_bh) {
2917                 retval = ext4_add_entry(handle, new_dentry, old_inode);
2918                 if (retval)
2919                         goto end_rename;
2920         } else {
2921                 BUFFER_TRACE(new_bh, "get write access");
2922                 retval = ext4_journal_get_write_access(handle, new_bh);
2923                 if (retval)
2924                         goto end_rename;
2925                 new_de->inode = cpu_to_le32(old_inode->i_ino);
2926                 if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
2927                                               EXT4_FEATURE_INCOMPAT_FILETYPE))
2928                         new_de->file_type = old_de->file_type;
2929                 new_dir->i_version++;
2930                 new_dir->i_ctime = new_dir->i_mtime =
2931                                         ext4_current_time(new_dir);
2932                 ext4_mark_inode_dirty(handle, new_dir);
2933                 BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata");
2934                 retval = ext4_handle_dirty_dirent_node(handle, new_dir, new_bh);
2935                 if (unlikely(retval)) {
2936                         ext4_std_error(new_dir->i_sb, retval);
2937                         goto end_rename;
2938                 }
2939                 brelse(new_bh);
2940                 new_bh = NULL;
2941         }
2942
2943         /*
2944          * Like most other Unix systems, set the ctime for inodes on a
2945          * rename.
2946          */
2947         old_inode->i_ctime = ext4_current_time(old_inode);
2948         ext4_mark_inode_dirty(handle, old_inode);
2949
2950         /*
2951          * ok, that's it
2952          */
2953         if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
2954             old_de->name_len != old_dentry->d_name.len ||
2955             strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
2956             (retval = ext4_delete_entry(handle, old_dir,
2957                                         old_de, old_bh)) == -ENOENT) {
2958                 /* old_de could have moved from under us during htree split, so
2959                  * make sure that we are deleting the right entry.  We might
2960                  * also be pointing to a stale entry in the unused part of
2961                  * old_bh so just checking inum and the name isn't enough. */
2962                 struct buffer_head *old_bh2;
2963                 struct ext4_dir_entry_2 *old_de2;
2964
2965                 old_bh2 = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de2);
2966                 if (old_bh2) {
2967                         retval = ext4_delete_entry(handle, old_dir,
2968                                                    old_de2, old_bh2);
2969                         brelse(old_bh2);
2970                 }
2971         }
2972         if (retval) {
2973                 ext4_warning(old_dir->i_sb,
2974                                 "Deleting old file (%lu), %d, error=%d",
2975                                 old_dir->i_ino, old_dir->i_nlink, retval);
2976         }
2977
2978         if (new_inode) {
2979                 ext4_dec_count(handle, new_inode);
2980                 new_inode->i_ctime = ext4_current_time(new_inode);
2981         }
2982         old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
2983         ext4_update_dx_flag(old_dir);
2984         if (dir_bh) {
2985                 PARENT_INO(dir_bh->b_data, new_dir->i_sb->s_blocksize) =
2986                                                 cpu_to_le32(new_dir->i_ino);
2987                 BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
2988                 if (is_dx(old_inode)) {
2989                         retval = ext4_handle_dirty_dx_node(handle,
2990                                                            old_inode,
2991                                                            dir_bh);
2992                 } else {
2993                         retval = ext4_handle_dirty_dirent_node(handle,
2994                                                                old_inode,
2995                                                                dir_bh);
2996                 }
2997                 if (retval) {
2998                         ext4_std_error(old_dir->i_sb, retval);
2999                         goto end_rename;
3000                 }
3001                 ext4_dec_count(handle, old_dir);
3002                 if (new_inode) {
3003                         /* checked empty_dir above, can't have another parent,
3004                          * ext4_dec_count() won't work for many-linked dirs */
3005                         clear_nlink(new_inode);
3006                 } else {
3007                         ext4_inc_count(handle, new_dir);
3008                         ext4_update_dx_flag(new_dir);
3009                         ext4_mark_inode_dirty(handle, new_dir);
3010                 }
3011         }
3012         ext4_mark_inode_dirty(handle, old_dir);
3013         if (new_inode) {
3014                 ext4_mark_inode_dirty(handle, new_inode);
3015                 if (!new_inode->i_nlink)
3016                         ext4_orphan_add(handle, new_inode);
3017                 if (!test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC))
3018                         force_da_alloc = 1;
3019         }
3020         retval = 0;
3021
3022 end_rename:
3023         brelse(dir_bh);
3024         brelse(old_bh);
3025         brelse(new_bh);
3026         ext4_journal_stop(handle);
3027         if (retval == 0 && force_da_alloc)
3028                 ext4_alloc_da_blocks(old_inode);
3029         return retval;
3030 }
3031
3032 /*
3033  * directories can handle most operations...
3034  */
3035 const struct inode_operations ext4_dir_inode_operations = {
3036         .create         = ext4_create,
3037         .lookup         = ext4_lookup,
3038         .link           = ext4_link,
3039         .unlink         = ext4_unlink,
3040         .symlink        = ext4_symlink,
3041         .mkdir          = ext4_mkdir,
3042         .rmdir          = ext4_rmdir,
3043         .mknod          = ext4_mknod,
3044         .rename         = ext4_rename,
3045         .setattr        = ext4_setattr,
3046 #ifdef CONFIG_EXT4_FS_XATTR
3047         .setxattr       = generic_setxattr,
3048         .getxattr       = generic_getxattr,
3049         .listxattr      = ext4_listxattr,
3050         .removexattr    = generic_removexattr,
3051 #endif
3052         .get_acl        = ext4_get_acl,
3053         .fiemap         = ext4_fiemap,
3054 };
3055
3056 const struct inode_operations ext4_special_inode_operations = {
3057         .setattr        = ext4_setattr,
3058 #ifdef CONFIG_EXT4_FS_XATTR
3059         .setxattr       = generic_setxattr,
3060         .getxattr       = generic_getxattr,
3061         .listxattr      = ext4_listxattr,
3062         .removexattr    = generic_removexattr,
3063 #endif
3064         .get_acl        = ext4_get_acl,
3065 };