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/ext4_fs.h>
  32 #include <linux/ext4_jbd2.h>
  33 #include <linux/fcntl.h>
  34 #include <linux/stat.h>
  35 #include <linux/string.h>
  36 #include <linux/quotaops.h>
  37 #include <linux/buffer_head.h>
  38 #include <linux/bio.h>
  39
  40 #include "namei.h"
  41 #include "xattr.h"
  42 #include "acl.h"
  43
  44 /*
  45  * define how far ahead to read directories while searching them.
  46  */
  47 #define NAMEI_RA_CHUNKS  2
  48 #define NAMEI_RA_BLOCKS  4
  49 #define NAMEI_RA_SIZE        (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
  50 #define NAMEI_RA_INDEX(c,b)  (((c) * NAMEI_RA_BLOCKS) + (b))
  51
  52 static struct buffer_head *ext4_append(handle_t *handle,
  53                                         struct inode *inode,
  54                                         ext4_lblk_t *block, int *err)
  55 {
  56         struct buffer_head *bh;
  57
  58         *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
  59
  60         if ((bh = ext4_bread(handle, inode, *block, 1, err))) {
  61                 inode->i_size += inode->i_sb->s_blocksize;
  62                 EXT4_I(inode)->i_disksize = inode->i_size;
  63                 ext4_journal_get_write_access(handle,bh);
  64         }
  65         return bh;
  66 }
  67
  68 #ifndef assert
  69 #define assert(test) J_ASSERT(test)
  70 #endif
  71
  72 #ifndef swap
  73 #define swap(x, y) do { typeof(x) z = x; x = y; y = z; } while (0)
  74 #endif
  75
  76 #ifdef DX_DEBUG
  77 #define dxtrace(command) command
  78 #else
  79 #define dxtrace(command)
  80 #endif
  81
  82 struct fake_dirent
  83 {
  84         __le32 inode;
  85         __le16 rec_len;
  86         u8 name_len;
  87         u8 file_type;
  88 };
  89
  90 struct dx_countlimit
  91 {
  92         __le16 limit;
  93         __le16 count;
  94 };
  95
  96 struct dx_entry
  97 {
  98         __le32 hash;
  99         __le32 block;
 100 };
 101
 102 /*
 103  * dx_root_info is laid out so that if it should somehow get overlaid by a
 104  * dirent the two low bits of the hash version will be zero.  Therefore, the
 105  * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
 106  */
 107
 108 struct dx_root
 109 {
 110         struct fake_dirent dot;
 111         char dot_name[4];
 112         struct fake_dirent dotdot;
 113         char dotdot_name[4];
 114         struct dx_root_info
 115         {
 116                 __le32 reserved_zero;
 117                 u8 hash_version;
 118                 u8 info_length; /* 8 */
 119                 u8 indirect_levels;
 120                 u8 unused_flags;
 121         }
 122         info;
 123         struct dx_entry entries[0];
 124 };
 125
 126 struct dx_node
 127 {
 128         struct fake_dirent fake;
 129         struct dx_entry entries[0];
 130 };
 131
 132
 133 struct dx_frame
 134 {
 135         struct buffer_head *bh;
 136         struct dx_entry *entries;
 137         struct dx_entry *at;
 138 };
 139
 140 struct dx_map_entry
 141 {
 142         u32 hash;
 143         u16 offs;
 144         u16 size;
 145 };
 146
 147 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
 148 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
 149 static inline unsigned dx_get_hash (struct dx_entry *entry);
 150 static void dx_set_hash (struct dx_entry *entry, unsigned value);
 151 static unsigned dx_get_count (struct dx_entry *entries);
 152 static unsigned dx_get_limit (struct dx_entry *entries);
 153 static void dx_set_count (struct dx_entry *entries, unsigned value);
 154 static void dx_set_limit (struct dx_entry *entries, unsigned value);
 155 static unsigned dx_root_limit (struct inode *dir, unsigned infosize);
 156 static unsigned dx_node_limit (struct inode *dir);
 157 static struct dx_frame *dx_probe(struct dentry *dentry,
 158                                  struct inode *dir,
 159                                  struct dx_hash_info *hinfo,
 160                                  struct dx_frame *frame,
 161                                  int *err);
 162 static void dx_release (struct dx_frame *frames);
 163 static int dx_make_map (struct ext4_dir_entry_2 *de, int size,
 164                         struct dx_hash_info *hinfo, struct dx_map_entry map[]);
 165 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
 166 static struct ext4_dir_entry_2 *dx_move_dirents (char *from, char *to,
 167                 struct dx_map_entry *offsets, int count);
 168 static struct ext4_dir_entry_2* dx_pack_dirents (char *base, int size);
 169 static void dx_insert_block(struct dx_frame *frame,
 170                                         u32 hash, ext4_lblk_t block);
 171 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 172                                  struct dx_frame *frame,
 173                                  struct dx_frame *frames,
 174                                  __u32 *start_hash);
 175 static struct buffer_head * ext4_dx_find_entry(struct dentry *dentry,
 176                        struct ext4_dir_entry_2 **res_dir, int *err);
 177 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
 178                              struct inode *inode);
 179
 180 /*
 181  * Future: use high four bits of block for coalesce-on-delete flags
 182  * Mask them off for now.
 183  */
 184
 185 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
 186 {
 187         return le32_to_cpu(entry->block) & 0x00ffffff;
 188 }
 189
 190 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
 191 {
 192         entry->block = cpu_to_le32(value);
 193 }
 194
 195 static inline unsigned dx_get_hash (struct dx_entry *entry)
 196 {
 197         return le32_to_cpu(entry->hash);
 198 }
 199
 200 static inline void dx_set_hash (struct dx_entry *entry, unsigned value)
 201 {
 202         entry->hash = cpu_to_le32(value);
 203 }
 204
 205 static inline unsigned dx_get_count (struct dx_entry *entries)
 206 {
 207         return le16_to_cpu(((struct dx_countlimit *) entries)->count);
 208 }
 209
 210 static inline unsigned dx_get_limit (struct dx_entry *entries)
 211 {
 212         return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
 213 }
 214
 215 static inline void dx_set_count (struct dx_entry *entries, unsigned value)
 216 {
 217         ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
 218 }
 219
 220 static inline void dx_set_limit (struct dx_entry *entries, unsigned value)
 221 {
 222         ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
 223 }
 224
 225 static inline unsigned dx_root_limit (struct inode *dir, unsigned infosize)
 226 {
 227         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
 228                 EXT4_DIR_REC_LEN(2) - infosize;
 229         return 0? 20: entry_space / sizeof(struct dx_entry);
 230 }
 231
 232 static inline unsigned dx_node_limit (struct inode *dir)
 233 {
 234         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
 235         return 0? 22: entry_space / sizeof(struct dx_entry);
 236 }
 237
 238 /*
 239  * Debug
 240  */
 241 #ifdef DX_DEBUG
 242 static void dx_show_index (char * label, struct dx_entry *entries)
 243 {
 244         int i, n = dx_get_count (entries);
 245         printk("%s index ", label);
 246         for (i = 0; i < n; i++) {
 247                 printk("%x->%lu ", i? dx_get_hash(entries + i) :
 248                                 0, (unsigned long)dx_get_block(entries + i));
 249         }
 250         printk("\n");
 251 }
 252
 253 struct stats
 254 {
 255         unsigned names;
 256         unsigned space;
 257         unsigned bcount;
 258 };
 259
 260 static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
 261                                  int size, int show_names)
 262 {
 263         unsigned names = 0, space = 0;
 264         char *base = (char *) de;
 265         struct dx_hash_info h = *hinfo;
 266
 267         printk("names: ");
 268         while ((char *) de < base + size)
 269         {
 270                 if (de->inode)
 271                 {
 272                         if (show_names)
 273                         {
 274                                 int len = de->name_len;
 275                                 char *name = de->name;
 276                                 while (len--) printk("%c", *name++);
 277                                 ext4fs_dirhash(de->name, de->name_len, &h);
 278                                 printk(":%x.%u ", h.hash,
 279                                        ((char *) de - base));
 280                         }
 281                         space += EXT4_DIR_REC_LEN(de->name_len);
 282                         names++;
 283                 }
 284                 de = ext4_next_entry(de);
 285         }
 286         printk("(%i)\n", names);
 287         return (struct stats) { names, space, 1 };
 288 }
 289
 290 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
 291                              struct dx_entry *entries, int levels)
 292 {
 293         unsigned blocksize = dir->i_sb->s_blocksize;
 294         unsigned count = dx_get_count (entries), names = 0, space = 0, i;
 295         unsigned bcount = 0;
 296         struct buffer_head *bh;
 297         int err;
 298         printk("%i indexed blocks...\n", count);
 299         for (i = 0; i < count; i++, entries++)
 300         {
 301                 ext4_lblk_t block = dx_get_block(entries);
 302                 ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
 303                 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
 304                 struct stats stats;
 305                 printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
 306                 if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue;
 307                 stats = levels?
 308                    dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
 309                    dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0);
 310                 names += stats.names;
 311                 space += stats.space;
 312                 bcount += stats.bcount;
 313                 brelse (bh);
 314         }
 315         if (bcount)
 316                 printk("%snames %u, fullness %u (%u%%)\n", levels?"":"   ",
 317                         names, space/bcount,(space/bcount)*100/blocksize);
 318         return (struct stats) { names, space, bcount};
 319 }
 320 #endif /* DX_DEBUG */
 321
 322 /*
 323  * Probe for a directory leaf block to search.
 324  *
 325  * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
 326  * error in the directory index, and the caller should fall back to
 327  * searching the directory normally.  The callers of dx_probe **MUST**
 328  * check for this error code, and make sure it never gets reflected
 329  * back to userspace.
 330  */
 331 static struct dx_frame *
 332 dx_probe(struct dentry *dentry, struct inode *dir,
 333          struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err)
 334 {
 335         unsigned count, indirect;
 336         struct dx_entry *at, *entries, *p, *q, *m;
 337         struct dx_root *root;
 338         struct buffer_head *bh;
 339         struct dx_frame *frame = frame_in;
 340         u32 hash;
 341
 342         frame->bh = NULL;
 343         if (dentry)
 344                 dir = dentry->d_parent->d_inode;
 345         if (!(bh = ext4_bread (NULL,dir, 0, 0, err)))
 346                 goto fail;
 347         root = (struct dx_root *) bh->b_data;
 348         if (root->info.hash_version != DX_HASH_TEA &&
 349             root->info.hash_version != DX_HASH_HALF_MD4 &&
 350             root->info.hash_version != DX_HASH_LEGACY) {
 351                 ext4_warning(dir->i_sb, __FUNCTION__,
 352                              "Unrecognised inode hash code %d",
 353                              root->info.hash_version);
 354                 brelse(bh);
 355                 *err = ERR_BAD_DX_DIR;
 356                 goto fail;
 357         }
 358         hinfo->hash_version = root->info.hash_version;
 359         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 360         if (dentry)
 361                 ext4fs_dirhash(dentry->d_name.name, dentry->d_name.len, hinfo);
 362         hash = hinfo->hash;
 363
 364         if (root->info.unused_flags & 1) {
 365                 ext4_warning(dir->i_sb, __FUNCTION__,
 366                              "Unimplemented inode hash flags: %#06x",
 367                              root->info.unused_flags);
 368                 brelse(bh);
 369                 *err = ERR_BAD_DX_DIR;
 370                 goto fail;
 371         }
 372
 373         if ((indirect = root->info.indirect_levels) > 1) {
 374                 ext4_warning(dir->i_sb, __FUNCTION__,
 375                              "Unimplemented inode hash depth: %#06x",
 376                              root->info.indirect_levels);
 377                 brelse(bh);
 378                 *err = ERR_BAD_DX_DIR;
 379                 goto fail;
 380         }
 381
 382         entries = (struct dx_entry *) (((char *)&root->info) +
 383                                        root->info.info_length);
 384
 385         if (dx_get_limit(entries) != dx_root_limit(dir,
 386                                                    root->info.info_length)) {
 387                 ext4_warning(dir->i_sb, __FUNCTION__,
 388                              "dx entry: limit != root limit");
 389                 brelse(bh);
 390                 *err = ERR_BAD_DX_DIR;
 391                 goto fail;
 392         }
 393
 394         dxtrace (printk("Look up %x", hash));
 395         while (1)
 396         {
 397                 count = dx_get_count(entries);
 398                 if (!count || count > dx_get_limit(entries)) {
 399                         ext4_warning(dir->i_sb, __FUNCTION__,
 400                                      "dx entry: no count or count > limit");
 401                         brelse(bh);
 402                         *err = ERR_BAD_DX_DIR;
 403                         goto fail2;
 404                 }
 405
 406                 p = entries + 1;
 407                 q = entries + count - 1;
 408                 while (p <= q)
 409                 {
 410                         m = p + (q - p)/2;
 411                         dxtrace(printk("."));
 412                         if (dx_get_hash(m) > hash)
 413                                 q = m - 1;
 414                         else
 415                                 p = m + 1;
 416                 }
 417
 418                 if (0) // linear search cross check
 419                 {
 420                         unsigned n = count - 1;
 421                         at = entries;
 422                         while (n--)
 423                         {
 424                                 dxtrace(printk(","));
 425                                 if (dx_get_hash(++at) > hash)
 426                                 {
 427                                         at--;
 428                                         break;
 429                                 }
 430                         }
 431                         assert (at == p - 1);
 432                 }
 433
 434                 at = p - 1;
 435                 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
 436                 frame->bh = bh;
 437                 frame->entries = entries;
 438                 frame->at = at;
 439                 if (!indirect--) return frame;
 440                 if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err)))
 441                         goto fail2;
 442                 at = entries = ((struct dx_node *) bh->b_data)->entries;
 443                 if (dx_get_limit(entries) != dx_node_limit (dir)) {
 444                         ext4_warning(dir->i_sb, __FUNCTION__,
 445                                      "dx entry: limit != node limit");
 446                         brelse(bh);
 447                         *err = ERR_BAD_DX_DIR;
 448                         goto fail2;
 449                 }
 450                 frame++;
 451                 frame->bh = NULL;
 452         }
 453 fail2:
 454         while (frame >= frame_in) {
 455                 brelse(frame->bh);
 456                 frame--;
 457         }
 458 fail:
 459         if (*err == ERR_BAD_DX_DIR)
 460                 ext4_warning(dir->i_sb, __FUNCTION__,
 461                              "Corrupt dir inode %ld, running e2fsck is "
 462                              "recommended.", dir->i_ino);
 463         return NULL;
 464 }
 465
 466 static void dx_release (struct dx_frame *frames)
 467 {
 468         if (frames[0].bh == NULL)
 469                 return;
 470
 471         if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
 472                 brelse(frames[1].bh);
 473         brelse(frames[0].bh);
 474 }
 475
 476 /*
 477  * This function increments the frame pointer to search the next leaf
 478  * block, and reads in the necessary intervening nodes if the search
 479  * should be necessary.  Whether or not the search is necessary is
 480  * controlled by the hash parameter.  If the hash value is even, then
 481  * the search is only continued if the next block starts with that
 482  * hash value.  This is used if we are searching for a specific file.
 483  *
 484  * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
 485  *
 486  * This function returns 1 if the caller should continue to search,
 487  * or 0 if it should not.  If there is an error reading one of the
 488  * index blocks, it will a negative error code.
 489  *
 490  * If start_hash is non-null, it will be filled in with the starting
 491  * hash of the next page.
 492  */
 493 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 494                                  struct dx_frame *frame,
 495                                  struct dx_frame *frames,
 496                                  __u32 *start_hash)
 497 {
 498         struct dx_frame *p;
 499         struct buffer_head *bh;
 500         int err, num_frames = 0;
 501         __u32 bhash;
 502
 503         p = frame;
 504         /*
 505          * Find the next leaf page by incrementing the frame pointer.
 506          * If we run out of entries in the interior node, loop around and
 507          * increment pointer in the parent node.  When we break out of
 508          * this loop, num_frames indicates the number of interior
 509          * nodes need to be read.
 510          */
 511         while (1) {
 512                 if (++(p->at) < p->entries + dx_get_count(p->entries))
 513                         break;
 514                 if (p == frames)
 515                         return 0;
 516                 num_frames++;
 517                 p--;
 518         }
 519
 520         /*
 521          * If the hash is 1, then continue only if the next page has a
 522          * continuation hash of any value.  This is used for readdir
 523          * handling.  Otherwise, check to see if the hash matches the
 524          * desired contiuation hash.  If it doesn't, return since
 525          * there's no point to read in the successive index pages.
 526          */
 527         bhash = dx_get_hash(p->at);
 528         if (start_hash)
 529                 *start_hash = bhash;
 530         if ((hash & 1) == 0) {
 531                 if ((bhash & ~1) != hash)
 532                         return 0;
 533         }
 534         /*
 535          * If the hash is HASH_NB_ALWAYS, we always go to the next
 536          * block so no check is necessary
 537          */
 538         while (num_frames--) {
 539                 if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at),
 540                                       0, &err)))
 541                         return err; /* Failure */
 542                 p++;
 543                 brelse (p->bh);
 544                 p->bh = bh;
 545                 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
 546         }
 547         return 1;
 548 }
 549
 550
 551 /*
 552  * p is at least 6 bytes before the end of page
 553  */
 554 static inline struct ext4_dir_entry_2 *ext4_next_entry(struct ext4_dir_entry_2 *p)
 555 {
 556         return (struct ext4_dir_entry_2 *)((char *)p +
 557                 ext4_rec_len_from_disk(p->rec_len));
 558 }
 559
 560 /*
 561  * This function fills a red-black tree with information from a
 562  * directory block.  It returns the number directory entries loaded
 563  * into the tree.  If there is an error it is returned in err.
 564  */
 565 static int htree_dirblock_to_tree(struct file *dir_file,
 566                                   struct inode *dir, ext4_lblk_t block,
 567                                   struct dx_hash_info *hinfo,
 568                                   __u32 start_hash, __u32 start_minor_hash)
 569 {
 570         struct buffer_head *bh;
 571         struct ext4_dir_entry_2 *de, *top;
 572         int err, count = 0;
 573
 574         dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
 575                                                         (unsigned long)block));
 576         if (!(bh = ext4_bread (NULL, dir, block, 0, &err)))
 577                 return err;
 578
 579         de = (struct ext4_dir_entry_2 *) bh->b_data;
 580         top = (struct ext4_dir_entry_2 *) ((char *) de +
 581                                            dir->i_sb->s_blocksize -
 582                                            EXT4_DIR_REC_LEN(0));
 583         for (; de < top; de = ext4_next_entry(de)) {
 584                 if (!ext4_check_dir_entry("htree_dirblock_to_tree", dir, de, bh,
 585                                         (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
 586                                                 +((char *)de - bh->b_data))) {
 587                         /* On error, skip the f_pos to the next block. */
 588                         dir_file->f_pos = (dir_file->f_pos |
 589                                         (dir->i_sb->s_blocksize - 1)) + 1;
 590                         brelse (bh);
 591                         return count;
 592                 }
 593                 ext4fs_dirhash(de->name, de->name_len, hinfo);
 594                 if ((hinfo->hash < start_hash) ||
 595                     ((hinfo->hash == start_hash) &&
 596                      (hinfo->minor_hash < start_minor_hash)))
 597                         continue;
 598                 if (de->inode == 0)
 599                         continue;
 600                 if ((err = ext4_htree_store_dirent(dir_file,
 601                                    hinfo->hash, hinfo->minor_hash, de)) != 0) {
 602                         brelse(bh);
 603                         return err;
 604                 }
 605                 count++;
 606         }
 607         brelse(bh);
 608         return count;
 609 }
 610
 611
 612 /*
 613  * This function fills a red-black tree with information from a
 614  * directory.  We start scanning the directory in hash order, starting
 615  * at start_hash and start_minor_hash.
 616  *
 617  * This function returns the number of entries inserted into the tree,
 618  * or a negative error code.
 619  */
 620 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
 621                          __u32 start_minor_hash, __u32 *next_hash)
 622 {
 623         struct dx_hash_info hinfo;
 624         struct ext4_dir_entry_2 *de;
 625         struct dx_frame frames[2], *frame;
 626         struct inode *dir;
 627         ext4_lblk_t block;
 628         int count = 0;
 629         int ret, err;
 630         __u32 hashval;
 631
 632         dxtrace(printk("In htree_fill_tree, start hash: %x:%x\n", start_hash,
 633                        start_minor_hash));
 634         dir = dir_file->f_path.dentry->d_inode;
 635         if (!(EXT4_I(dir)->i_flags & EXT4_INDEX_FL)) {
 636                 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
 637                 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 638                 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
 639                                                start_hash, start_minor_hash);
 640                 *next_hash = ~0;
 641                 return count;
 642         }
 643         hinfo.hash = start_hash;
 644         hinfo.minor_hash = 0;
 645         frame = dx_probe(NULL, dir_file->f_path.dentry->d_inode, &hinfo, frames, &err);
 646         if (!frame)
 647                 return err;
 648
 649         /* Add '.' and '..' from the htree header */
 650         if (!start_hash && !start_minor_hash) {
 651                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
 652                 if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
 653                         goto errout;
 654                 count++;
 655         }
 656         if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
 657                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
 658                 de = ext4_next_entry(de);
 659                 if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
 660                         goto errout;
 661                 count++;
 662         }
 663
 664         while (1) {
 665                 block = dx_get_block(frame->at);
 666                 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
 667                                              start_hash, start_minor_hash);
 668                 if (ret < 0) {
 669                         err = ret;
 670                         goto errout;
 671                 }
 672                 count += ret;
 673                 hashval = ~0;
 674                 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
 675                                             frame, frames, &hashval);
 676                 *next_hash = hashval;
 677                 if (ret < 0) {
 678                         err = ret;
 679                         goto errout;
 680                 }
 681                 /*
 682                  * Stop if:  (a) there are no more entries, or
 683                  * (b) we have inserted at least one entry and the
 684                  * next hash value is not a continuation
 685                  */
 686                 if ((ret == 0) ||
 687                     (count && ((hashval & 1) == 0)))
 688                         break;
 689         }
 690         dx_release(frames);
 691         dxtrace(printk("Fill tree: returned %d entries, next hash: %x\n",
 692                        count, *next_hash));
 693         return count;
 694 errout:
 695         dx_release(frames);
 696         return (err);
 697 }
 698
 699
 700 /*
 701  * Directory block splitting, compacting
 702  */
 703
 704 /*
 705  * Create map of hash values, offsets, and sizes, stored at end of block.
 706  * Returns number of entries mapped.
 707  */
 708 static int dx_make_map (struct ext4_dir_entry_2 *de, int size,
 709                         struct dx_hash_info *hinfo, struct dx_map_entry *map_tail)
 710 {
 711         int count = 0;
 712         char *base = (char *) de;
 713         struct dx_hash_info h = *hinfo;
 714
 715         while ((char *) de < base + size)
 716         {
 717                 if (de->name_len && de->inode) {
 718                         ext4fs_dirhash(de->name, de->name_len, &h);
 719                         map_tail--;
 720                         map_tail->hash = h.hash;
 721                         map_tail->offs = (u16) ((char *) de - base);
 722                         map_tail->size = le16_to_cpu(de->rec_len);
 723                         count++;
 724                         cond_resched();
 725                 }
 726                 /* XXX: do we need to check rec_len == 0 case? -Chris */
 727                 de = ext4_next_entry(de);
 728         }
 729         return count;
 730 }
 731
 732 /* Sort map by hash value */
 733 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
 734 {
 735         struct dx_map_entry *p, *q, *top = map + count - 1;
 736         int more;
 737         /* Combsort until bubble sort doesn't suck */
 738         while (count > 2) {
 739                 count = count*10/13;
 740                 if (count - 9 < 2) /* 9, 10 -> 11 */
 741                         count = 11;
 742                 for (p = top, q = p - count; q >= map; p--, q--)
 743                         if (p->hash < q->hash)
 744                                 swap(*p, *q);
 745         }
 746         /* Garden variety bubble sort */
 747         do {
 748                 more = 0;
 749                 q = top;
 750                 while (q-- > map) {
 751                         if (q[1].hash >= q[0].hash)
 752                                 continue;
 753                         swap(*(q+1), *q);
 754                         more = 1;
 755                 }
 756         } while(more);
 757 }
 758
 759 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
 760 {
 761         struct dx_entry *entries = frame->entries;
 762         struct dx_entry *old = frame->at, *new = old + 1;
 763         int count = dx_get_count(entries);
 764
 765         assert(count < dx_get_limit(entries));
 766         assert(old < entries + count);
 767         memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
 768         dx_set_hash(new, hash);
 769         dx_set_block(new, block);
 770         dx_set_count(entries, count + 1);
 771 }
 772
 773 static void ext4_update_dx_flag(struct inode *inode)
 774 {
 775         if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
 776                                      EXT4_FEATURE_COMPAT_DIR_INDEX))
 777                 EXT4_I(inode)->i_flags &= ~EXT4_INDEX_FL;
 778 }
 779
 780 /*
 781  * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
 782  *
 783  * `len <= EXT4_NAME_LEN' is guaranteed by caller.
 784  * `de != NULL' is guaranteed by caller.
 785  */
 786 static inline int ext4_match (int len, const char * const name,
 787                               struct ext4_dir_entry_2 * de)
 788 {
 789         if (len != de->name_len)
 790                 return 0;
 791         if (!de->inode)
 792                 return 0;
 793         return !memcmp(name, de->name, len);
 794 }
 795
 796 /*
 797  * Returns 0 if not found, -1 on failure, and 1 on success
 798  */
 799 static inline int search_dirblock(struct buffer_head * bh,
 800                                   struct inode *dir,
 801                                   struct dentry *dentry,
 802                                   unsigned long offset,
 803                                   struct ext4_dir_entry_2 ** res_dir)
 804 {
 805         struct ext4_dir_entry_2 * de;
 806         char * dlimit;
 807         int de_len;
 808         const char *name = dentry->d_name.name;
 809         int namelen = dentry->d_name.len;
 810
 811         de = (struct ext4_dir_entry_2 *) bh->b_data;
 812         dlimit = bh->b_data + dir->i_sb->s_blocksize;
 813         while ((char *) de < dlimit) {
 814                 /* this code is executed quadratically often */
 815                 /* do minimal checking `by hand' */
 816
 817                 if ((char *) de + namelen <= dlimit &&
 818                     ext4_match (namelen, name, de)) {
 819                         /* found a match - just to be sure, do a full check */
 820                         if (!ext4_check_dir_entry("ext4_find_entry",
 821                                                   dir, de, bh, offset))
 822                                 return -1;
 823                         *res_dir = de;
 824                         return 1;
 825                 }
 826                 /* prevent looping on a bad block */
 827                 de_len = ext4_rec_len_from_disk(de->rec_len);
 828                 if (de_len <= 0)
 829                         return -1;
 830                 offset += de_len;
 831                 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
 832         }
 833         return 0;
 834 }
 835
 836
 837 /*
 838  *      ext4_find_entry()
 839  *
 840  * finds an entry in the specified directory with the wanted name. It
 841  * returns the cache buffer in which the entry was found, and the entry
 842  * itself (as a parameter - res_dir). It does NOT read the inode of the
 843  * entry - you'll have to do that yourself if you want to.
 844  *
 845  * The returned buffer_head has ->b_count elevated.  The caller is expected
 846  * to brelse() it when appropriate.
 847  */
 848 static struct buffer_head * ext4_find_entry (struct dentry *dentry,
 849                                         struct ext4_dir_entry_2 ** res_dir)
 850 {
 851         struct super_block * sb;
 852         struct buffer_head * bh_use[NAMEI_RA_SIZE];
 853         struct buffer_head * bh, *ret = NULL;
 854         ext4_lblk_t start, block, b;
 855         int ra_max = 0;         /* Number of bh's in the readahead
 856                                    buffer, bh_use[] */
 857         int ra_ptr = 0;         /* Current index into readahead
 858                                    buffer */
 859         int num = 0;
 860         ext4_lblk_t  nblocks;
 861         int i, err;
 862         struct inode *dir = dentry->d_parent->d_inode;
 863         int namelen;
 864
 865         *res_dir = NULL;
 866         sb = dir->i_sb;
 867         namelen = dentry->d_name.len;
 868         if (namelen > EXT4_NAME_LEN)
 869                 return NULL;
 870         if (is_dx(dir)) {
 871                 bh = ext4_dx_find_entry(dentry, res_dir, &err);
 872                 /*
 873                  * On success, or if the error was file not found,
 874                  * return.  Otherwise, fall back to doing a search the
 875                  * old fashioned way.
 876                  */
 877                 if (bh || (err != ERR_BAD_DX_DIR))
 878                         return bh;
 879                 dxtrace(printk("ext4_find_entry: dx failed, falling back\n"));
 880         }
 881         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
 882         start = EXT4_I(dir)->i_dir_start_lookup;
 883         if (start >= nblocks)
 884                 start = 0;
 885         block = start;
 886 restart:
 887         do {
 888                 /*
 889                  * We deal with the read-ahead logic here.
 890                  */
 891                 if (ra_ptr >= ra_max) {
 892                         /* Refill the readahead buffer */
 893                         ra_ptr = 0;
 894                         b = block;
 895                         for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
 896                                 /*
 897                                  * Terminate if we reach the end of the
 898                                  * directory and must wrap, or if our
 899                                  * search has finished at this block.
 900                                  */
 901                                 if (b >= nblocks || (num && block == start)) {
 902                                         bh_use[ra_max] = NULL;
 903                                         break;
 904                                 }
 905                                 num++;
 906                                 bh = ext4_getblk(NULL, dir, b++, 0, &err);
 907                                 bh_use[ra_max] = bh;
 908                                 if (bh)
 909                                         ll_rw_block(READ_META, 1, &bh);
 910                         }
 911                 }
 912                 if ((bh = bh_use[ra_ptr++]) == NULL)
 913                         goto next;
 914                 wait_on_buffer(bh);
 915                 if (!buffer_uptodate(bh)) {
 916                         /* read error, skip block & hope for the best */
 917                         ext4_error(sb, __FUNCTION__, "reading directory #%lu "
 918                                    "offset %lu", dir->i_ino,
 919                                    (unsigned long)block);
 920                         brelse(bh);
 921                         goto next;
 922                 }
 923                 i = search_dirblock(bh, dir, dentry,
 924                             block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
 925                 if (i == 1) {
 926                         EXT4_I(dir)->i_dir_start_lookup = block;
 927                         ret = bh;
 928                         goto cleanup_and_exit;
 929                 } else {
 930                         brelse(bh);
 931                         if (i < 0)
 932                                 goto cleanup_and_exit;
 933                 }
 934         next:
 935                 if (++block >= nblocks)
 936                         block = 0;
 937         } while (block != start);
 938
 939         /*
 940          * If the directory has grown while we were searching, then
 941          * search the last part of the directory before giving up.
 942          */
 943         block = nblocks;
 944         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
 945         if (block < nblocks) {
 946                 start = 0;
 947                 goto restart;
 948         }
 949
 950 cleanup_and_exit:
 951         /* Clean up the read-ahead blocks */
 952         for (; ra_ptr < ra_max; ra_ptr++)
 953                 brelse (bh_use[ra_ptr]);
 954         return ret;
 955 }
 956
 957 static struct buffer_head * ext4_dx_find_entry(struct dentry *dentry,
 958                        struct ext4_dir_entry_2 **res_dir, int *err)
 959 {
 960         struct super_block * sb;
 961         struct dx_hash_info     hinfo;
 962         u32 hash;
 963         struct dx_frame frames[2], *frame;
 964         struct ext4_dir_entry_2 *de, *top;
 965         struct buffer_head *bh;
 966         ext4_lblk_t block;
 967         int retval;
 968         int namelen = dentry->d_name.len;
 969         const u8 *name = dentry->d_name.name;
 970         struct inode *dir = dentry->d_parent->d_inode;
 971
 972         sb = dir->i_sb;
 973         /* NFS may look up ".." - look at dx_root directory block */
 974         if (namelen > 2 || name[0] != '.'||(name[1] != '.' && name[1] != '\0')){
 975                 if (!(frame = dx_probe(dentry, NULL, &hinfo, frames, err)))
 976                         return NULL;
 977         } else {
 978                 frame = frames;
 979                 frame->bh = NULL;                       /* for dx_release() */
 980                 frame->at = (struct dx_entry *)frames;  /* hack for zero entry*/
 981                 dx_set_block(frame->at, 0);             /* dx_root block is 0 */
 982         }
 983         hash = hinfo.hash;
 984         do {
 985                 block = dx_get_block(frame->at);
 986                 if (!(bh = ext4_bread (NULL,dir, block, 0, err)))
 987                         goto errout;
 988                 de = (struct ext4_dir_entry_2 *) bh->b_data;
 989                 top = (struct ext4_dir_entry_2 *) ((char *) de + sb->s_blocksize -
 990                                        EXT4_DIR_REC_LEN(0));
 991                 for (; de < top; de = ext4_next_entry(de))
 992                 if (ext4_match (namelen, name, de)) {
 993                         if (!ext4_check_dir_entry("ext4_find_entry",
 994                                                   dir, de, bh,
 995                                   (block<<EXT4_BLOCK_SIZE_BITS(sb))
 996                                           +((char *)de - bh->b_data))) {
 997                                 brelse (bh);
 998                                 *err = ERR_BAD_DX_DIR;
 999                                 goto errout;
1000                         }
1001                         *res_dir = de;
1002                         dx_release (frames);
1003                         return bh;
1004                 }
1005                 brelse (bh);
1006                 /* Check to see if we should continue to search */
1007                 retval = ext4_htree_next_block(dir, hash, frame,
1008                                                frames, NULL);
1009                 if (retval < 0) {
1010                         ext4_warning(sb, __FUNCTION__,
1011                              "error reading index page in directory #%lu",
1012                              dir->i_ino);
1013                         *err = retval;
1014                         goto errout;
1015                 }
1016         } while (retval == 1);
1017
1018         *err = -ENOENT;
1019 errout:
1020         dxtrace(printk("%s not found\n", name));
1021         dx_release (frames);
1022         return NULL;
1023 }
1024
1025 static struct dentry *ext4_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
1026 {
1027         struct inode * inode;
1028         struct ext4_dir_entry_2 * de;
1029         struct buffer_head * bh;
1030
1031         if (dentry->d_name.len > EXT4_NAME_LEN)
1032                 return ERR_PTR(-ENAMETOOLONG);
1033
1034         bh = ext4_find_entry(dentry, &de);
1035         inode = NULL;
1036         if (bh) {
1037                 unsigned long ino = le32_to_cpu(de->inode);
1038                 brelse (bh);
1039                 if (!ext4_valid_inum(dir->i_sb, ino)) {
1040                         ext4_error(dir->i_sb, "ext4_lookup",
1041                                    "bad inode number: %lu", ino);
1042                         inode = NULL;
1043                 } else
1044                         inode = iget(dir->i_sb, ino);
1045
1046                 if (!inode)
1047                         return ERR_PTR(-EACCES);
1048
1049                 if (is_bad_inode(inode)) {
1050                         iput(inode);
1051                         return ERR_PTR(-ENOENT);
1052                 }
1053         }
1054         return d_splice_alias(inode, dentry);
1055 }
1056
1057
1058 struct dentry *ext4_get_parent(struct dentry *child)
1059 {
1060         unsigned long ino;
1061         struct dentry *parent;
1062         struct inode *inode;
1063         struct dentry dotdot;
1064         struct ext4_dir_entry_2 * de;
1065         struct buffer_head *bh;
1066
1067         dotdot.d_name.name = "..";
1068         dotdot.d_name.len = 2;
1069         dotdot.d_parent = child; /* confusing, isn't it! */
1070
1071         bh = ext4_find_entry(&dotdot, &de);
1072         inode = NULL;
1073         if (!bh)
1074                 return ERR_PTR(-ENOENT);
1075         ino = le32_to_cpu(de->inode);
1076         brelse(bh);
1077
1078         if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
1079                 ext4_error(child->d_inode->i_sb, "ext4_get_parent",
1080                            "bad inode number: %lu", ino);
1081                 inode = NULL;
1082         } else
1083                 inode = iget(child->d_inode->i_sb, ino);
1084
1085         if (!inode)
1086                 return ERR_PTR(-EACCES);
1087
1088         if (is_bad_inode(inode)) {
1089                 iput(inode);
1090                 return ERR_PTR(-ENOENT);
1091         }
1092
1093         parent = d_alloc_anon(inode);
1094         if (!parent) {
1095                 iput(inode);
1096                 parent = ERR_PTR(-ENOMEM);
1097         }
1098         return parent;
1099 }
1100
1101 #define S_SHIFT 12
1102 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
1103         [S_IFREG >> S_SHIFT]    = EXT4_FT_REG_FILE,
1104         [S_IFDIR >> S_SHIFT]    = EXT4_FT_DIR,
1105         [S_IFCHR >> S_SHIFT]    = EXT4_FT_CHRDEV,
1106         [S_IFBLK >> S_SHIFT]    = EXT4_FT_BLKDEV,
1107         [S_IFIFO >> S_SHIFT]    = EXT4_FT_FIFO,
1108         [S_IFSOCK >> S_SHIFT]   = EXT4_FT_SOCK,
1109         [S_IFLNK >> S_SHIFT]    = EXT4_FT_SYMLINK,
1110 };
1111
1112 static inline void ext4_set_de_type(struct super_block *sb,
1113                                 struct ext4_dir_entry_2 *de,
1114                                 umode_t mode) {
1115         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
1116                 de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
1117 }
1118
1119 /*
1120  * Move count entries from end of map between two memory locations.
1121  * Returns pointer to last entry moved.
1122  */
1123 static struct ext4_dir_entry_2 *
1124 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count)
1125 {
1126         unsigned rec_len = 0;
1127
1128         while (count--) {
1129                 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) (from + map->offs);
1130                 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1131                 memcpy (to, de, rec_len);
1132                 ((struct ext4_dir_entry_2 *) to)->rec_len =
1133                                 ext4_rec_len_to_disk(rec_len);
1134                 de->inode = 0;
1135                 map++;
1136                 to += rec_len;
1137         }
1138         return (struct ext4_dir_entry_2 *) (to - rec_len);
1139 }
1140
1141 /*
1142  * Compact each dir entry in the range to the minimal rec_len.
1143  * Returns pointer to last entry in range.
1144  */
1145 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, int size)
1146 {
1147         struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1148         unsigned rec_len = 0;
1149
1150         prev = to = de;
1151         while ((char*)de < base + size) {
1152                 next = ext4_next_entry(de);
1153                 if (de->inode && de->name_len) {
1154                         rec_len = EXT4_DIR_REC_LEN(de->name_len);
1155                         if (de > to)
1156                                 memmove(to, de, rec_len);
1157                         to->rec_len = ext4_rec_len_to_disk(rec_len);
1158                         prev = to;
1159                         to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1160                 }
1161                 de = next;
1162         }
1163         return prev;
1164 }
1165
1166 /*
1167  * Split a full leaf block to make room for a new dir entry.
1168  * Allocate a new block, and move entries so that they are approx. equally full.
1169  * Returns pointer to de in block into which the new entry will be inserted.
1170  */
1171 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1172                         struct buffer_head **bh,struct dx_frame *frame,
1173                         struct dx_hash_info *hinfo, int *error)
1174 {
1175         unsigned blocksize = dir->i_sb->s_blocksize;
1176         unsigned count, continued;
1177         struct buffer_head *bh2;
1178         ext4_lblk_t newblock;
1179         u32 hash2;
1180         struct dx_map_entry *map;
1181         char *data1 = (*bh)->b_data, *data2;
1182         unsigned split, move, size, i;
1183         struct ext4_dir_entry_2 *de = NULL, *de2;
1184         int     err = 0;
1185
1186         bh2 = ext4_append (handle, dir, &newblock, &err);
1187         if (!(bh2)) {
1188                 brelse(*bh);
1189                 *bh = NULL;
1190                 goto errout;
1191         }
1192
1193         BUFFER_TRACE(*bh, "get_write_access");
1194         err = ext4_journal_get_write_access(handle, *bh);
1195         if (err)
1196                 goto journal_error;
1197
1198         BUFFER_TRACE(frame->bh, "get_write_access");
1199         err = ext4_journal_get_write_access(handle, frame->bh);
1200         if (err)
1201                 goto journal_error;
1202
1203         data2 = bh2->b_data;
1204
1205         /* create map in the end of data2 block */
1206         map = (struct dx_map_entry *) (data2 + blocksize);
1207         count = dx_make_map ((struct ext4_dir_entry_2 *) data1,
1208                              blocksize, hinfo, map);
1209         map -= count;
1210         dx_sort_map (map, count);
1211         /* Split the existing block in the middle, size-wise */
1212         size = 0;
1213         move = 0;
1214         for (i = count-1; i >= 0; i--) {
1215                 /* is more than half of this entry in 2nd half of the block? */
1216                 if (size + map[i].size/2 > blocksize/2)
1217                         break;
1218                 size += map[i].size;
1219                 move++;
1220         }
1221         /* map index at which we will split */
1222         split = count - move;
1223         hash2 = map[split].hash;
1224         continued = hash2 == map[split - 1].hash;
1225         dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1226                         (unsigned long)dx_get_block(frame->at),
1227                                         hash2, split, count-split));
1228
1229         /* Fancy dance to stay within two buffers */
1230         de2 = dx_move_dirents(data1, data2, map + split, count - split);
1231         de = dx_pack_dirents(data1,blocksize);
1232         de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de);
1233         de2->rec_len = ext4_rec_len_to_disk(data2 + blocksize - (char *) de2);
1234         dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
1235         dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
1236
1237         /* Which block gets the new entry? */
1238         if (hinfo->hash >= hash2)
1239         {
1240                 swap(*bh, bh2);
1241                 de = de2;
1242         }
1243         dx_insert_block (frame, hash2 + continued, newblock);
1244         err = ext4_journal_dirty_metadata (handle, bh2);
1245         if (err)
1246                 goto journal_error;
1247         err = ext4_journal_dirty_metadata (handle, frame->bh);
1248         if (err)
1249                 goto journal_error;
1250         brelse (bh2);
1251         dxtrace(dx_show_index ("frame", frame->entries));
1252         return de;
1253
1254 journal_error:
1255         brelse(*bh);
1256         brelse(bh2);
1257         *bh = NULL;
1258         ext4_std_error(dir->i_sb, err);
1259 errout:
1260         *error = err;
1261         return NULL;
1262 }
1263
1264 /*
1265  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1266  * it points to a directory entry which is guaranteed to be large
1267  * enough for new directory entry.  If de is NULL, then
1268  * add_dirent_to_buf will attempt search the directory block for
1269  * space.  It will return -ENOSPC if no space is available, and -EIO
1270  * and -EEXIST if directory entry already exists.
1271  *
1272  * NOTE!  bh is NOT released in the case where ENOSPC is returned.  In
1273  * all other cases bh is released.
1274  */
1275 static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1276                              struct inode *inode, struct ext4_dir_entry_2 *de,
1277                              struct buffer_head * bh)
1278 {
1279         struct inode    *dir = dentry->d_parent->d_inode;
1280         const char      *name = dentry->d_name.name;
1281         int             namelen = dentry->d_name.len;
1282         unsigned long   offset = 0;
1283         unsigned short  reclen;
1284         int             nlen, rlen, err;
1285         char            *top;
1286
1287         reclen = EXT4_DIR_REC_LEN(namelen);
1288         if (!de) {
1289                 de = (struct ext4_dir_entry_2 *)bh->b_data;
1290                 top = bh->b_data + dir->i_sb->s_blocksize - reclen;
1291                 while ((char *) de <= top) {
1292                         if (!ext4_check_dir_entry("ext4_add_entry", dir, de,
1293                                                   bh, offset)) {
1294                                 brelse (bh);
1295                                 return -EIO;
1296                         }
1297                         if (ext4_match (namelen, name, de)) {
1298                                 brelse (bh);
1299                                 return -EEXIST;
1300                         }
1301                         nlen = EXT4_DIR_REC_LEN(de->name_len);
1302                         rlen = ext4_rec_len_from_disk(de->rec_len);
1303                         if ((de->inode? rlen - nlen: rlen) >= reclen)
1304                                 break;
1305                         de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1306                         offset += rlen;
1307                 }
1308                 if ((char *) de > top)
1309                         return -ENOSPC;
1310         }
1311         BUFFER_TRACE(bh, "get_write_access");
1312         err = ext4_journal_get_write_access(handle, bh);
1313         if (err) {
1314                 ext4_std_error(dir->i_sb, err);
1315                 brelse(bh);
1316                 return err;
1317         }
1318
1319         /* By now the buffer is marked for journaling */
1320         nlen = EXT4_DIR_REC_LEN(de->name_len);
1321         rlen = ext4_rec_len_from_disk(de->rec_len);
1322         if (de->inode) {
1323                 struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen);
1324                 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen);
1325                 de->rec_len = ext4_rec_len_to_disk(nlen);
1326                 de = de1;
1327         }
1328         de->file_type = EXT4_FT_UNKNOWN;
1329         if (inode) {
1330                 de->inode = cpu_to_le32(inode->i_ino);
1331                 ext4_set_de_type(dir->i_sb, de, inode->i_mode);
1332         } else
1333                 de->inode = 0;
1334         de->name_len = namelen;
1335         memcpy (de->name, name, namelen);
1336         /*
1337          * XXX shouldn't update any times until successful
1338          * completion of syscall, but too many callers depend
1339          * on this.
1340          *
1341          * XXX similarly, too many callers depend on
1342          * ext4_new_inode() setting the times, but error
1343          * recovery deletes the inode, so the worst that can
1344          * happen is that the times are slightly out of date
1345          * and/or different from the directory change time.
1346          */
1347         dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1348         ext4_update_dx_flag(dir);
1349         dir->i_version++;
1350         ext4_mark_inode_dirty(handle, dir);
1351         BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata");
1352         err = ext4_journal_dirty_metadata(handle, bh);
1353         if (err)
1354                 ext4_std_error(dir->i_sb, err);
1355         brelse(bh);
1356         return 0;
1357 }
1358
1359 /*
1360  * This converts a one block unindexed directory to a 3 block indexed
1361  * directory, and adds the dentry to the indexed directory.
1362  */
1363 static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
1364                             struct inode *inode, struct buffer_head *bh)
1365 {
1366         struct inode    *dir = dentry->d_parent->d_inode;
1367         const char      *name = dentry->d_name.name;
1368         int             namelen = dentry->d_name.len;
1369         struct buffer_head *bh2;
1370         struct dx_root  *root;
1371         struct dx_frame frames[2], *frame;
1372         struct dx_entry *entries;
1373         struct ext4_dir_entry_2 *de, *de2;
1374         char            *data1, *top;
1375         unsigned        len;
1376         int             retval;
1377         unsigned        blocksize;
1378         struct dx_hash_info hinfo;
1379         ext4_lblk_t  block;
1380         struct fake_dirent *fde;
1381
1382         blocksize =  dir->i_sb->s_blocksize;
1383         dxtrace(printk("Creating index\n"));
1384         retval = ext4_journal_get_write_access(handle, bh);
1385         if (retval) {
1386                 ext4_std_error(dir->i_sb, retval);
1387                 brelse(bh);
1388                 return retval;
1389         }
1390         root = (struct dx_root *) bh->b_data;
1391
1392         bh2 = ext4_append (handle, dir, &block, &retval);
1393         if (!(bh2)) {
1394                 brelse(bh);
1395                 return retval;
1396         }
1397         EXT4_I(dir)->i_flags |= EXT4_INDEX_FL;
1398         data1 = bh2->b_data;
1399
1400         /* The 0th block becomes the root, move the dirents out */
1401         fde = &root->dotdot;
1402         de = (struct ext4_dir_entry_2 *)((char *)fde +
1403                 ext4_rec_len_from_disk(fde->rec_len));
1404         len = ((char *) root) + blocksize - (char *) de;
1405         memcpy (data1, de, len);
1406         de = (struct ext4_dir_entry_2 *) data1;
1407         top = data1 + len;
1408         while ((char *)(de2 = ext4_next_entry(de)) < top)
1409                 de = de2;
1410         de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de);
1411         /* Initialize the root; the dot dirents already exist */
1412         de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1413         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2));
1414         memset (&root->info, 0, sizeof(root->info));
1415         root->info.info_length = sizeof(root->info);
1416         root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1417         entries = root->entries;
1418         dx_set_block (entries, 1);
1419         dx_set_count (entries, 1);
1420         dx_set_limit (entries, dx_root_limit(dir, sizeof(root->info)));
1421
1422         /* Initialize as for dx_probe */
1423         hinfo.hash_version = root->info.hash_version;
1424         hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1425         ext4fs_dirhash(name, namelen, &hinfo);
1426         frame = frames;
1427         frame->entries = entries;
1428         frame->at = entries;
1429         frame->bh = bh;
1430         bh = bh2;
1431         de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
1432         dx_release (frames);
1433         if (!(de))
1434                 return retval;
1435
1436         return add_dirent_to_buf(handle, dentry, inode, de, bh);
1437 }
1438
1439 /*
1440  *      ext4_add_entry()
1441  *
1442  * adds a file entry to the specified directory, using the same
1443  * semantics as ext4_find_entry(). It returns NULL if it failed.
1444  *
1445  * NOTE!! The inode part of 'de' is left at 0 - which means you
1446  * may not sleep between calling this and putting something into
1447  * the entry, as someone else might have used it while you slept.
1448  */
1449 static int ext4_add_entry (handle_t *handle, struct dentry *dentry,
1450         struct inode *inode)
1451 {
1452         struct inode *dir = dentry->d_parent->d_inode;
1453         unsigned long offset;
1454         struct buffer_head * bh;
1455         struct ext4_dir_entry_2 *de;
1456         struct super_block * sb;
1457         int     retval;
1458         int     dx_fallback=0;
1459         unsigned blocksize;
1460         ext4_lblk_t block, blocks;
1461
1462         sb = dir->i_sb;
1463         blocksize = sb->s_blocksize;
1464         if (!dentry->d_name.len)
1465                 return -EINVAL;
1466         if (is_dx(dir)) {
1467                 retval = ext4_dx_add_entry(handle, dentry, inode);
1468                 if (!retval || (retval != ERR_BAD_DX_DIR))
1469                         return retval;
1470                 EXT4_I(dir)->i_flags &= ~EXT4_INDEX_FL;
1471                 dx_fallback++;
1472                 ext4_mark_inode_dirty(handle, dir);
1473         }
1474         blocks = dir->i_size >> sb->s_blocksize_bits;
1475         for (block = 0, offset = 0; block < blocks; block++) {
1476                 bh = ext4_bread(handle, dir, block, 0, &retval);
1477                 if(!bh)
1478                         return retval;
1479                 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1480                 if (retval != -ENOSPC)
1481                         return retval;
1482
1483                 if (blocks == 1 && !dx_fallback &&
1484                     EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
1485                         return make_indexed_dir(handle, dentry, inode, bh);
1486                 brelse(bh);
1487         }
1488         bh = ext4_append(handle, dir, &block, &retval);
1489         if (!bh)
1490                 return retval;
1491         de = (struct ext4_dir_entry_2 *) bh->b_data;
1492         de->inode = 0;
1493         de->rec_len = ext4_rec_len_to_disk(blocksize);
1494         return add_dirent_to_buf(handle, dentry, inode, de, bh);
1495 }
1496
1497 /*
1498  * Returns 0 for success, or a negative error value
1499  */
1500 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
1501                              struct inode *inode)
1502 {
1503         struct dx_frame frames[2], *frame;
1504         struct dx_entry *entries, *at;
1505         struct dx_hash_info hinfo;
1506         struct buffer_head * bh;
1507         struct inode *dir = dentry->d_parent->d_inode;
1508         struct super_block * sb = dir->i_sb;
1509         struct ext4_dir_entry_2 *de;
1510         int err;
1511
1512         frame = dx_probe(dentry, NULL, &hinfo, frames, &err);
1513         if (!frame)
1514                 return err;
1515         entries = frame->entries;
1516         at = frame->at;
1517
1518         if (!(bh = ext4_bread(handle,dir, dx_get_block(frame->at), 0, &err)))
1519                 goto cleanup;
1520
1521         BUFFER_TRACE(bh, "get_write_access");
1522         err = ext4_journal_get_write_access(handle, bh);
1523         if (err)
1524                 goto journal_error;
1525
1526         err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1527         if (err != -ENOSPC) {
1528                 bh = NULL;
1529                 goto cleanup;
1530         }
1531
1532         /* Block full, should compress but for now just split */
1533         dxtrace(printk("using %u of %u node entries\n",
1534                        dx_get_count(entries), dx_get_limit(entries)));
1535         /* Need to split index? */
1536         if (dx_get_count(entries) == dx_get_limit(entries)) {
1537                 ext4_lblk_t newblock;
1538                 unsigned icount = dx_get_count(entries);
1539                 int levels = frame - frames;
1540                 struct dx_entry *entries2;
1541                 struct dx_node *node2;
1542                 struct buffer_head *bh2;
1543
1544                 if (levels && (dx_get_count(frames->entries) ==
1545                                dx_get_limit(frames->entries))) {
1546                         ext4_warning(sb, __FUNCTION__,
1547                                      "Directory index full!");
1548                         err = -ENOSPC;
1549                         goto cleanup;
1550                 }
1551                 bh2 = ext4_append (handle, dir, &newblock, &err);
1552                 if (!(bh2))
1553                         goto cleanup;
1554                 node2 = (struct dx_node *)(bh2->b_data);
1555                 entries2 = node2->entries;
1556                 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize);
1557                 node2->fake.inode = 0;
1558                 BUFFER_TRACE(frame->bh, "get_write_access");
1559                 err = ext4_journal_get_write_access(handle, frame->bh);
1560                 if (err)
1561                         goto journal_error;
1562                 if (levels) {
1563                         unsigned icount1 = icount/2, icount2 = icount - icount1;
1564                         unsigned hash2 = dx_get_hash(entries + icount1);
1565                         dxtrace(printk("Split index %i/%i\n", icount1, icount2));
1566
1567                         BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
1568                         err = ext4_journal_get_write_access(handle,
1569                                                              frames[0].bh);
1570                         if (err)
1571                                 goto journal_error;
1572
1573                         memcpy ((char *) entries2, (char *) (entries + icount1),
1574                                 icount2 * sizeof(struct dx_entry));
1575                         dx_set_count (entries, icount1);
1576                         dx_set_count (entries2, icount2);
1577                         dx_set_limit (entries2, dx_node_limit(dir));
1578
1579                         /* Which index block gets the new entry? */
1580                         if (at - entries >= icount1) {
1581                                 frame->at = at = at - entries - icount1 + entries2;
1582                                 frame->entries = entries = entries2;
1583                                 swap(frame->bh, bh2);
1584                         }
1585                         dx_insert_block (frames + 0, hash2, newblock);
1586                         dxtrace(dx_show_index ("node", frames[1].entries));
1587                         dxtrace(dx_show_index ("node",
1588                                ((struct dx_node *) bh2->b_data)->entries));
1589                         err = ext4_journal_dirty_metadata(handle, bh2);
1590                         if (err)
1591                                 goto journal_error;
1592                         brelse (bh2);
1593                 } else {
1594                         dxtrace(printk("Creating second level index...\n"));
1595                         memcpy((char *) entries2, (char *) entries,
1596                                icount * sizeof(struct dx_entry));
1597                         dx_set_limit(entries2, dx_node_limit(dir));
1598
1599                         /* Set up root */
1600                         dx_set_count(entries, 1);
1601                         dx_set_block(entries + 0, newblock);
1602                         ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
1603
1604                         /* Add new access path frame */
1605                         frame = frames + 1;
1606                         frame->at = at = at - entries + entries2;
1607                         frame->entries = entries = entries2;
1608                         frame->bh = bh2;
1609                         err = ext4_journal_get_write_access(handle,
1610                                                              frame->bh);
1611                         if (err)
1612                                 goto journal_error;
1613                 }
1614                 ext4_journal_dirty_metadata(handle, frames[0].bh);
1615         }
1616         de = do_split(handle, dir, &bh, frame, &hinfo, &err);
1617         if (!de)
1618                 goto cleanup;
1619         err = add_dirent_to_buf(handle, dentry, inode, de, bh);
1620         bh = NULL;
1621         goto cleanup;
1622
1623 journal_error:
1624         ext4_std_error(dir->i_sb, err);
1625 cleanup:
1626         if (bh)
1627                 brelse(bh);
1628         dx_release(frames);
1629         return err;
1630 }
1631
1632 /*
1633  * ext4_delete_entry deletes a directory entry by merging it with the
1634  * previous entry
1635  */
1636 static int ext4_delete_entry (handle_t *handle,
1637                               struct inode * dir,
1638                               struct ext4_dir_entry_2 * de_del,
1639                               struct buffer_head * bh)
1640 {
1641         struct ext4_dir_entry_2 * de, * pde;
1642         int i;
1643
1644         i = 0;
1645         pde = NULL;
1646         de = (struct ext4_dir_entry_2 *) bh->b_data;
1647         while (i < bh->b_size) {
1648                 if (!ext4_check_dir_entry("ext4_delete_entry", dir, de, bh, i))
1649                         return -EIO;
1650                 if (de == de_del)  {
1651                         BUFFER_TRACE(bh, "get_write_access");
1652                         ext4_journal_get_write_access(handle, bh);
1653                         if (pde)
1654                                 pde->rec_len = ext4_rec_len_to_disk(
1655                                         ext4_rec_len_from_disk(pde->rec_len) +
1656                                         ext4_rec_len_from_disk(de->rec_len));
1657                         else
1658                                 de->inode = 0;
1659                         dir->i_version++;
1660                         BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata");
1661                         ext4_journal_dirty_metadata(handle, bh);
1662                         return 0;
1663                 }
1664                 i += ext4_rec_len_from_disk(de->rec_len);
1665                 pde = de;
1666                 de = ext4_next_entry(de);
1667         }
1668         return -ENOENT;
1669 }
1670
1671 /*
1672  * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
1673  * since this indicates that nlinks count was previously 1.
1674  */
1675 static void ext4_inc_count(handle_t *handle, struct inode *inode)
1676 {
1677         inc_nlink(inode);
1678         if (is_dx(inode) && inode->i_nlink > 1) {
1679                 /* limit is 16-bit i_links_count */
1680                 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
1681                         inode->i_nlink = 1;
1682                         EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
1683                                               EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
1684                 }
1685         }
1686 }
1687
1688 /*
1689  * If a directory had nlink == 1, then we should let it be 1. This indicates
1690  * directory has >EXT4_LINK_MAX subdirs.
1691  */
1692 static void ext4_dec_count(handle_t *handle, struct inode *inode)
1693 {
1694         drop_nlink(inode);
1695         if (S_ISDIR(inode->i_mode) && inode->i_nlink == 0)
1696                 inc_nlink(inode);
1697 }
1698
1699
1700 static int ext4_add_nondir(handle_t *handle,
1701                 struct dentry *dentry, struct inode *inode)
1702 {
1703         int err = ext4_add_entry(handle, dentry, inode);
1704         if (!err) {
1705                 ext4_mark_inode_dirty(handle, inode);
1706                 d_instantiate(dentry, inode);
1707                 return 0;
1708         }
1709         drop_nlink(inode);
1710         iput(inode);
1711         return err;
1712 }
1713
1714 /*
1715  * By the time this is called, we already have created
1716  * the directory cache entry for the new file, but it
1717  * is so far negative - it has no inode.
1718  *
1719  * If the create succeeds, we fill in the inode information
1720  * with d_instantiate().
1721  */
1722 static int ext4_create (struct inode * dir, struct dentry * dentry, int mode,
1723                 struct nameidata *nd)
1724 {
1725         handle_t *handle;
1726         struct inode * inode;
1727         int err, retries = 0;
1728
1729 retry:
1730         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1731                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1732                                         2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
1733         if (IS_ERR(handle))
1734                 return PTR_ERR(handle);
1735
1736         if (IS_DIRSYNC(dir))
1737                 handle->h_sync = 1;
1738
1739         inode = ext4_new_inode (handle, dir, mode);
1740         err = PTR_ERR(inode);
1741         if (!IS_ERR(inode)) {
1742                 inode->i_op = &ext4_file_inode_operations;
1743                 inode->i_fop = &ext4_file_operations;
1744                 ext4_set_aops(inode);
1745                 err = ext4_add_nondir(handle, dentry, inode);
1746         }
1747         ext4_journal_stop(handle);
1748         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1749                 goto retry;
1750         return err;
1751 }
1752
1753 static int ext4_mknod (struct inode * dir, struct dentry *dentry,
1754                         int mode, dev_t rdev)
1755 {
1756         handle_t *handle;
1757         struct inode *inode;
1758         int err, retries = 0;
1759
1760         if (!new_valid_dev(rdev))
1761                 return -EINVAL;
1762
1763 retry:
1764         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1765                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1766                                         2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
1767         if (IS_ERR(handle))
1768                 return PTR_ERR(handle);
1769
1770         if (IS_DIRSYNC(dir))
1771                 handle->h_sync = 1;
1772
1773         inode = ext4_new_inode (handle, dir, mode);
1774         err = PTR_ERR(inode);
1775         if (!IS_ERR(inode)) {
1776                 init_special_inode(inode, inode->i_mode, rdev);
1777 #ifdef CONFIG_EXT4DEV_FS_XATTR
1778                 inode->i_op = &ext4_special_inode_operations;
1779 #endif
1780                 err = ext4_add_nondir(handle, dentry, inode);
1781         }
1782         ext4_journal_stop(handle);
1783         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1784                 goto retry;
1785         return err;
1786 }
1787
1788 static int ext4_mkdir(struct inode * dir, struct dentry * dentry, int mode)
1789 {
1790         handle_t *handle;
1791         struct inode * inode;
1792         struct buffer_head * dir_block;
1793         struct ext4_dir_entry_2 * de;
1794         int err, retries = 0;
1795
1796         if (EXT4_DIR_LINK_MAX(dir))
1797                 return -EMLINK;
1798
1799 retry:
1800         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1801                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1802                                         2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
1803         if (IS_ERR(handle))
1804                 return PTR_ERR(handle);
1805
1806         if (IS_DIRSYNC(dir))
1807                 handle->h_sync = 1;
1808
1809         inode = ext4_new_inode (handle, dir, S_IFDIR | mode);
1810         err = PTR_ERR(inode);
1811         if (IS_ERR(inode))
1812                 goto out_stop;
1813
1814         inode->i_op = &ext4_dir_inode_operations;
1815         inode->i_fop = &ext4_dir_operations;
1816         inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
1817         dir_block = ext4_bread (handle, inode, 0, 1, &err);
1818         if (!dir_block) {
1819                 ext4_dec_count(handle, inode); /* is this nlink == 0? */
1820                 ext4_mark_inode_dirty(handle, inode);
1821                 iput (inode);
1822                 goto out_stop;
1823         }
1824         BUFFER_TRACE(dir_block, "get_write_access");
1825         ext4_journal_get_write_access(handle, dir_block);
1826         de = (struct ext4_dir_entry_2 *) dir_block->b_data;
1827         de->inode = cpu_to_le32(inode->i_ino);
1828         de->name_len = 1;
1829         de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len));
1830         strcpy (de->name, ".");
1831         ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1832         de = ext4_next_entry(de);
1833         de->inode = cpu_to_le32(dir->i_ino);
1834         de->rec_len = ext4_rec_len_to_disk(inode->i_sb->s_blocksize -
1835                                                 EXT4_DIR_REC_LEN(1));
1836         de->name_len = 2;
1837         strcpy (de->name, "..");
1838         ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1839         inode->i_nlink = 2;
1840         BUFFER_TRACE(dir_block, "call ext4_journal_dirty_metadata");
1841         ext4_journal_dirty_metadata(handle, dir_block);
1842         brelse (dir_block);
1843         ext4_mark_inode_dirty(handle, inode);
1844         err = ext4_add_entry (handle, dentry, inode);
1845         if (err) {
1846                 inode->i_nlink = 0;
1847                 ext4_mark_inode_dirty(handle, inode);
1848                 iput (inode);
1849                 goto out_stop;
1850         }
1851         ext4_inc_count(handle, dir);
1852         ext4_update_dx_flag(dir);
1853         ext4_mark_inode_dirty(handle, dir);
1854         d_instantiate(dentry, inode);
1855 out_stop:
1856         ext4_journal_stop(handle);
1857         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1858                 goto retry;
1859         return err;
1860 }
1861
1862 /*
1863  * routine to check that the specified directory is empty (for rmdir)
1864  */
1865 static int empty_dir (struct inode * inode)
1866 {
1867         unsigned long offset;
1868         struct buffer_head * bh;
1869         struct ext4_dir_entry_2 * de, * de1;
1870         struct super_block * sb;
1871         int err = 0;
1872
1873         sb = inode->i_sb;
1874         if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) ||
1875             !(bh = ext4_bread (NULL, inode, 0, 0, &err))) {
1876                 if (err)
1877                         ext4_error(inode->i_sb, __FUNCTION__,
1878                                    "error %d reading directory #%lu offset 0",
1879                                    err, inode->i_ino);
1880                 else
1881                         ext4_warning(inode->i_sb, __FUNCTION__,
1882                                      "bad directory (dir #%lu) - no data block",
1883                                      inode->i_ino);
1884                 return 1;
1885         }
1886         de = (struct ext4_dir_entry_2 *) bh->b_data;
1887         de1 = ext4_next_entry(de);
1888         if (le32_to_cpu(de->inode) != inode->i_ino ||
1889                         !le32_to_cpu(de1->inode) ||
1890                         strcmp (".", de->name) ||
1891                         strcmp ("..", de1->name)) {
1892                 ext4_warning (inode->i_sb, "empty_dir",
1893                               "bad directory (dir #%lu) - no `.' or `..'",
1894                               inode->i_ino);
1895                 brelse (bh);
1896                 return 1;
1897         }
1898         offset = ext4_rec_len_from_disk(de->rec_len) +
1899                  ext4_rec_len_from_disk(de1->rec_len);
1900         de = ext4_next_entry(de1);
1901         while (offset < inode->i_size ) {
1902                 if (!bh ||
1903                         (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
1904                         err = 0;
1905                         brelse (bh);
1906                         bh = ext4_bread (NULL, inode,
1907                                 offset >> EXT4_BLOCK_SIZE_BITS(sb), 0, &err);
1908                         if (!bh) {
1909                                 if (err)
1910                                         ext4_error(sb, __FUNCTION__,
1911                                                    "error %d reading directory"
1912                                                    " #%lu offset %lu",
1913                                                    err, inode->i_ino, offset);
1914                                 offset += sb->s_blocksize;
1915                                 continue;
1916                         }
1917                         de = (struct ext4_dir_entry_2 *) bh->b_data;
1918                 }
1919                 if (!ext4_check_dir_entry("empty_dir", inode, de, bh, offset)) {
1920                         de = (struct ext4_dir_entry_2 *)(bh->b_data +
1921                                                          sb->s_blocksize);
1922                         offset = (offset | (sb->s_blocksize - 1)) + 1;
1923                         continue;
1924                 }
1925                 if (le32_to_cpu(de->inode)) {
1926                         brelse (bh);
1927                         return 0;
1928                 }
1929                 offset += ext4_rec_len_from_disk(de->rec_len);
1930                 de = ext4_next_entry(de);
1931         }
1932         brelse (bh);
1933         return 1;
1934 }
1935
1936 /* ext4_orphan_add() links an unlinked or truncated inode into a list of
1937  * such inodes, starting at the superblock, in case we crash before the
1938  * file is closed/deleted, or in case the inode truncate spans multiple
1939  * transactions and the last transaction is not recovered after a crash.
1940  *
1941  * At filesystem recovery time, we walk this list deleting unlinked
1942  * inodes and truncating linked inodes in ext4_orphan_cleanup().
1943  */
1944 int ext4_orphan_add(handle_t *handle, struct inode *inode)
1945 {
1946         struct super_block *sb = inode->i_sb;
1947         struct ext4_iloc iloc;
1948         int err = 0, rc;
1949
1950         lock_super(sb);
1951         if (!list_empty(&EXT4_I(inode)->i_orphan))
1952                 goto out_unlock;
1953
1954         /* Orphan handling is only valid for files with data blocks
1955          * being truncated, or files being unlinked. */
1956
1957         /* @@@ FIXME: Observation from aviro:
1958          * I think I can trigger J_ASSERT in ext4_orphan_add().  We block
1959          * here (on lock_super()), so race with ext4_link() which might bump
1960          * ->i_nlink. For, say it, character device. Not a regular file,
1961          * not a directory, not a symlink and ->i_nlink > 0.
1962          */
1963         J_ASSERT ((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
1964                 S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
1965
1966         BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
1967         err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
1968         if (err)
1969                 goto out_unlock;
1970
1971         err = ext4_reserve_inode_write(handle, inode, &iloc);
1972         if (err)
1973                 goto out_unlock;
1974
1975         /* Insert this inode at the head of the on-disk orphan list... */
1976         NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
1977         EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
1978         err = ext4_journal_dirty_metadata(handle, EXT4_SB(sb)->s_sbh);
1979         rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
1980         if (!err)
1981                 err = rc;
1982
1983         /* Only add to the head of the in-memory list if all the
1984          * previous operations succeeded.  If the orphan_add is going to
1985          * fail (possibly taking the journal offline), we can't risk
1986          * leaving the inode on the orphan list: stray orphan-list
1987          * entries can cause panics at unmount time.
1988          *
1989          * This is safe: on error we're going to ignore the orphan list
1990          * anyway on the next recovery. */
1991         if (!err)
1992                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1993
1994         jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
1995         jbd_debug(4, "orphan inode %lu will point to %d\n",
1996                         inode->i_ino, NEXT_ORPHAN(inode));
1997 out_unlock:
1998         unlock_super(sb);
1999         ext4_std_error(inode->i_sb, err);
2000         return err;
2001 }
2002
2003 /*
2004  * ext4_orphan_del() removes an unlinked or truncated inode from the list
2005  * of such inodes stored on disk, because it is finally being cleaned up.
2006  */
2007 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2008 {
2009         struct list_head *prev;
2010         struct ext4_inode_info *ei = EXT4_I(inode);
2011         struct ext4_sb_info *sbi;
2012         unsigned long ino_next;
2013         struct ext4_iloc iloc;
2014         int err = 0;
2015
2016         lock_super(inode->i_sb);
2017         if (list_empty(&ei->i_orphan)) {
2018                 unlock_super(inode->i_sb);
2019                 return 0;
2020         }
2021
2022         ino_next = NEXT_ORPHAN(inode);
2023         prev = ei->i_orphan.prev;
2024         sbi = EXT4_SB(inode->i_sb);
2025
2026         jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2027
2028         list_del_init(&ei->i_orphan);
2029
2030         /* If we're on an error path, we may not have a valid
2031          * transaction handle with which to update the orphan list on
2032          * disk, but we still need to remove the inode from the linked
2033          * list in memory. */
2034         if (!handle)
2035                 goto out;
2036
2037         err = ext4_reserve_inode_write(handle, inode, &iloc);
2038         if (err)
2039                 goto out_err;
2040
2041         if (prev == &sbi->s_orphan) {
2042                 jbd_debug(4, "superblock will point to %lu\n", ino_next);
2043                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2044                 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2045                 if (err)
2046                         goto out_brelse;
2047                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2048                 err = ext4_journal_dirty_metadata(handle, sbi->s_sbh);
2049         } else {
2050                 struct ext4_iloc iloc2;
2051                 struct inode *i_prev =
2052                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2053
2054                 jbd_debug(4, "orphan inode %lu will point to %lu\n",
2055                           i_prev->i_ino, ino_next);
2056                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2057                 if (err)
2058                         goto out_brelse;
2059                 NEXT_ORPHAN(i_prev) = ino_next;
2060                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2061         }
2062         if (err)
2063                 goto out_brelse;
2064         NEXT_ORPHAN(inode) = 0;
2065         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2066
2067 out_err:
2068         ext4_std_error(inode->i_sb, err);
2069 out:
2070         unlock_super(inode->i_sb);
2071         return err;
2072
2073 out_brelse:
2074         brelse(iloc.bh);
2075         goto out_err;
2076 }
2077
2078 static int ext4_rmdir (struct inode * dir, struct dentry *dentry)
2079 {
2080         int retval;
2081         struct inode * inode;
2082         struct buffer_head * bh;
2083         struct ext4_dir_entry_2 * de;
2084         handle_t *handle;
2085
2086         /* Initialize quotas before so that eventual writes go in
2087          * separate transaction */
2088         DQUOT_INIT(dentry->d_inode);
2089         handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2090         if (IS_ERR(handle))
2091                 return PTR_ERR(handle);
2092
2093         retval = -ENOENT;
2094         bh = ext4_find_entry (dentry, &de);
2095         if (!bh)
2096                 goto end_rmdir;
2097
2098         if (IS_DIRSYNC(dir))
2099                 handle->h_sync = 1;
2100
2101         inode = dentry->d_inode;
2102
2103         retval = -EIO;
2104         if (le32_to_cpu(de->inode) != inode->i_ino)
2105                 goto end_rmdir;
2106
2107         retval = -ENOTEMPTY;
2108         if (!empty_dir (inode))
2109                 goto end_rmdir;
2110
2111         retval = ext4_delete_entry(handle, dir, de, bh);
2112         if (retval)
2113                 goto end_rmdir;
2114         if (!EXT4_DIR_LINK_EMPTY(inode))
2115                 ext4_warning (inode->i_sb, "ext4_rmdir",
2116                               "empty directory has too many links (%d)",
2117                               inode->i_nlink);
2118         inode->i_version++;
2119         clear_nlink(inode);
2120         /* There's no need to set i_disksize: the fact that i_nlink is
2121          * zero will ensure that the right thing happens during any
2122          * recovery. */
2123         inode->i_size = 0;
2124         ext4_orphan_add(handle, inode);
2125         inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2126         ext4_mark_inode_dirty(handle, inode);
2127         ext4_dec_count(handle, dir);
2128         ext4_update_dx_flag(dir);
2129         ext4_mark_inode_dirty(handle, dir);
2130
2131 end_rmdir:
2132         ext4_journal_stop(handle);
2133         brelse (bh);
2134         return retval;
2135 }
2136
2137 static int ext4_unlink(struct inode * dir, struct dentry *dentry)
2138 {
2139         int retval;
2140         struct inode * inode;
2141         struct buffer_head * bh;
2142         struct ext4_dir_entry_2 * de;
2143         handle_t *handle;
2144
2145         /* Initialize quotas before so that eventual writes go
2146          * in separate transaction */
2147         DQUOT_INIT(dentry->d_inode);
2148         handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2149         if (IS_ERR(handle))
2150                 return PTR_ERR(handle);
2151
2152         if (IS_DIRSYNC(dir))
2153                 handle->h_sync = 1;
2154
2155         retval = -ENOENT;
2156         bh = ext4_find_entry (dentry, &de);
2157         if (!bh)
2158                 goto end_unlink;
2159
2160         inode = dentry->d_inode;
2161
2162         retval = -EIO;
2163         if (le32_to_cpu(de->inode) != inode->i_ino)
2164                 goto end_unlink;
2165
2166         if (!inode->i_nlink) {
2167                 ext4_warning (inode->i_sb, "ext4_unlink",
2168                               "Deleting nonexistent file (%lu), %d",
2169                               inode->i_ino, inode->i_nlink);
2170                 inode->i_nlink = 1;
2171         }
2172         retval = ext4_delete_entry(handle, dir, de, bh);
2173         if (retval)
2174                 goto end_unlink;
2175         dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
2176         ext4_update_dx_flag(dir);
2177         ext4_mark_inode_dirty(handle, dir);
2178         ext4_dec_count(handle, inode);
2179         if (!inode->i_nlink)
2180                 ext4_orphan_add(handle, inode);
2181         inode->i_ctime = ext4_current_time(inode);
2182         ext4_mark_inode_dirty(handle, inode);
2183         retval = 0;
2184
2185 end_unlink:
2186         ext4_journal_stop(handle);
2187         brelse (bh);
2188         return retval;
2189 }
2190
2191 static int ext4_symlink (struct inode * dir,
2192                 struct dentry *dentry, const char * symname)
2193 {
2194         handle_t *handle;
2195         struct inode * inode;
2196         int l, err, retries = 0;
2197
2198         l = strlen(symname)+1;
2199         if (l > dir->i_sb->s_blocksize)
2200                 return -ENAMETOOLONG;
2201
2202 retry:
2203         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2204                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 5 +
2205                                         2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
2206         if (IS_ERR(handle))
2207                 return PTR_ERR(handle);
2208
2209         if (IS_DIRSYNC(dir))
2210                 handle->h_sync = 1;
2211
2212         inode = ext4_new_inode (handle, dir, S_IFLNK|S_IRWXUGO);
2213         err = PTR_ERR(inode);
2214         if (IS_ERR(inode))
2215                 goto out_stop;
2216
2217         if (l > sizeof (EXT4_I(inode)->i_data)) {
2218                 inode->i_op = &ext4_symlink_inode_operations;
2219                 ext4_set_aops(inode);
2220                 /*
2221                  * page_symlink() calls into ext4_prepare/commit_write.
2222                  * We have a transaction open.  All is sweetness.  It also sets
2223                  * i_size in generic_commit_write().
2224                  */
2225                 err = __page_symlink(inode, symname, l,
2226                                 mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
2227                 if (err) {
2228                         ext4_dec_count(handle, inode);
2229                         ext4_mark_inode_dirty(handle, inode);
2230                         iput (inode);
2231                         goto out_stop;
2232                 }
2233         } else {
2234                 inode->i_op = &ext4_fast_symlink_inode_operations;
2235                 memcpy((char*)&EXT4_I(inode)->i_data,symname,l);
2236                 inode->i_size = l-1;
2237         }
2238         EXT4_I(inode)->i_disksize = inode->i_size;
2239         err = ext4_add_nondir(handle, dentry, inode);
2240 out_stop:
2241         ext4_journal_stop(handle);
2242         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2243                 goto retry;
2244         return err;
2245 }
2246
2247 static int ext4_link (struct dentry * old_dentry,
2248                 struct inode * dir, struct dentry *dentry)
2249 {
2250         handle_t *handle;
2251         struct inode *inode = old_dentry->d_inode;
2252         int err, retries = 0;
2253
2254         if (EXT4_DIR_LINK_MAX(inode))
2255                 return -EMLINK;
2256
2257         /*
2258          * Return -ENOENT if we've raced with unlink and i_nlink is 0.  Doing
2259          * otherwise has the potential to corrupt the orphan inode list.
2260          */
2261         if (inode->i_nlink == 0)
2262                 return -ENOENT;
2263
2264 retry:
2265         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2266                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS);
2267         if (IS_ERR(handle))
2268                 return PTR_ERR(handle);
2269
2270         if (IS_DIRSYNC(dir))
2271                 handle->h_sync = 1;
2272
2273         inode->i_ctime = ext4_current_time(inode);
2274         ext4_inc_count(handle, inode);
2275         atomic_inc(&inode->i_count);
2276
2277         err = ext4_add_nondir(handle, dentry, inode);
2278         ext4_journal_stop(handle);
2279         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2280                 goto retry;
2281         return err;
2282 }
2283
2284 #define PARENT_INO(buffer) \
2285         (ext4_next_entry((struct ext4_dir_entry_2 *)(buffer))->inode)
2286
2287 /*
2288  * Anybody can rename anything with this: the permission checks are left to the
2289  * higher-level routines.
2290  */
2291 static int ext4_rename (struct inode * old_dir, struct dentry *old_dentry,
2292                            struct inode * new_dir,struct dentry *new_dentry)
2293 {
2294         handle_t *handle;
2295         struct inode * old_inode, * new_inode;
2296         struct buffer_head * old_bh, * new_bh, * dir_bh;
2297         struct ext4_dir_entry_2 * old_de, * new_de;
2298         int retval;
2299
2300         old_bh = new_bh = dir_bh = NULL;
2301
2302         /* Initialize quotas before so that eventual writes go
2303          * in separate transaction */
2304         if (new_dentry->d_inode)
2305                 DQUOT_INIT(new_dentry->d_inode);
2306         handle = ext4_journal_start(old_dir, 2 *
2307                                         EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
2308                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
2309         if (IS_ERR(handle))
2310                 return PTR_ERR(handle);
2311
2312         if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
2313                 handle->h_sync = 1;
2314
2315         old_bh = ext4_find_entry (old_dentry, &old_de);
2316         /*
2317          *  Check for inode number is _not_ due to possible IO errors.
2318          *  We might rmdir the source, keep it as pwd of some process
2319          *  and merrily kill the link to whatever was created under the
2320          *  same name. Goodbye sticky bit ;-<
2321          */
2322         old_inode = old_dentry->d_inode;
2323         retval = -ENOENT;
2324         if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
2325                 goto end_rename;
2326
2327         new_inode = new_dentry->d_inode;
2328         new_bh = ext4_find_entry (new_dentry, &new_de);
2329         if (new_bh) {
2330                 if (!new_inode) {
2331                         brelse (new_bh);
2332                         new_bh = NULL;
2333                 }
2334         }
2335         if (S_ISDIR(old_inode->i_mode)) {
2336                 if (new_inode) {
2337                         retval = -ENOTEMPTY;
2338                         if (!empty_dir (new_inode))
2339                                 goto end_rename;
2340                 }
2341                 retval = -EIO;
2342                 dir_bh = ext4_bread (handle, old_inode, 0, 0, &retval);
2343                 if (!dir_bh)
2344                         goto end_rename;
2345                 if (le32_to_cpu(PARENT_INO(dir_bh->b_data)) != old_dir->i_ino)
2346                         goto end_rename;
2347                 retval = -EMLINK;
2348                 if (!new_inode && new_dir!=old_dir &&
2349                                 new_dir->i_nlink >= EXT4_LINK_MAX)
2350                         goto end_rename;
2351         }
2352         if (!new_bh) {
2353                 retval = ext4_add_entry (handle, new_dentry, old_inode);
2354                 if (retval)
2355                         goto end_rename;
2356         } else {
2357                 BUFFER_TRACE(new_bh, "get write access");
2358                 ext4_journal_get_write_access(handle, new_bh);
2359                 new_de->inode = cpu_to_le32(old_inode->i_ino);
2360                 if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
2361                                               EXT4_FEATURE_INCOMPAT_FILETYPE))
2362                         new_de->file_type = old_de->file_type;
2363                 new_dir->i_version++;
2364                 BUFFER_TRACE(new_bh, "call ext4_journal_dirty_metadata");
2365                 ext4_journal_dirty_metadata(handle, new_bh);
2366                 brelse(new_bh);
2367                 new_bh = NULL;
2368         }
2369
2370         /*
2371          * Like most other Unix systems, set the ctime for inodes on a
2372          * rename.
2373          */
2374         old_inode->i_ctime = ext4_current_time(old_inode);
2375         ext4_mark_inode_dirty(handle, old_inode);
2376
2377         /*
2378          * ok, that's it
2379          */
2380         if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
2381             old_de->name_len != old_dentry->d_name.len ||
2382             strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
2383             (retval = ext4_delete_entry(handle, old_dir,
2384                                         old_de, old_bh)) == -ENOENT) {
2385                 /* old_de could have moved from under us during htree split, so
2386                  * make sure that we are deleting the right entry.  We might
2387                  * also be pointing to a stale entry in the unused part of
2388                  * old_bh so just checking inum and the name isn't enough. */
2389                 struct buffer_head *old_bh2;
2390                 struct ext4_dir_entry_2 *old_de2;
2391
2392                 old_bh2 = ext4_find_entry(old_dentry, &old_de2);
2393                 if (old_bh2) {
2394                         retval = ext4_delete_entry(handle, old_dir,
2395                                                    old_de2, old_bh2);
2396                         brelse(old_bh2);
2397                 }
2398         }
2399         if (retval) {
2400                 ext4_warning(old_dir->i_sb, "ext4_rename",
2401                                 "Deleting old file (%lu), %d, error=%d",
2402                                 old_dir->i_ino, old_dir->i_nlink, retval);
2403         }
2404
2405         if (new_inode) {
2406                 ext4_dec_count(handle, new_inode);
2407                 new_inode->i_ctime = ext4_current_time(new_inode);
2408         }
2409         old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
2410         ext4_update_dx_flag(old_dir);
2411         if (dir_bh) {
2412                 BUFFER_TRACE(dir_bh, "get_write_access");
2413                 ext4_journal_get_write_access(handle, dir_bh);
2414                 PARENT_INO(dir_bh->b_data) = cpu_to_le32(new_dir->i_ino);
2415                 BUFFER_TRACE(dir_bh, "call ext4_journal_dirty_metadata");
2416                 ext4_journal_dirty_metadata(handle, dir_bh);
2417                 ext4_dec_count(handle, old_dir);
2418                 if (new_inode) {
2419                         /* checked empty_dir above, can't have another parent,
2420                          * ext3_dec_count() won't work for many-linked dirs */
2421                         new_inode->i_nlink = 0;
2422                 } else {
2423                         ext4_inc_count(handle, new_dir);
2424                         ext4_update_dx_flag(new_dir);
2425                         ext4_mark_inode_dirty(handle, new_dir);
2426                 }
2427         }
2428         ext4_mark_inode_dirty(handle, old_dir);
2429         if (new_inode) {
2430                 ext4_mark_inode_dirty(handle, new_inode);
2431                 if (!new_inode->i_nlink)
2432                         ext4_orphan_add(handle, new_inode);
2433         }
2434         retval = 0;
2435
2436 end_rename:
2437         brelse (dir_bh);
2438         brelse (old_bh);
2439         brelse (new_bh);
2440         ext4_journal_stop(handle);
2441         return retval;
2442 }
2443
2444 /*
2445  * directories can handle most operations...
2446  */
2447 const struct inode_operations ext4_dir_inode_operations = {
2448         .create         = ext4_create,
2449         .lookup         = ext4_lookup,
2450         .link           = ext4_link,
2451         .unlink         = ext4_unlink,
2452         .symlink        = ext4_symlink,
2453         .mkdir          = ext4_mkdir,
2454         .rmdir          = ext4_rmdir,
2455         .mknod          = ext4_mknod,
2456         .rename         = ext4_rename,
2457         .setattr        = ext4_setattr,
2458 #ifdef CONFIG_EXT4DEV_FS_XATTR
2459         .setxattr       = generic_setxattr,
2460         .getxattr       = generic_getxattr,
2461         .listxattr      = ext4_listxattr,
2462         .removexattr    = generic_removexattr,
2463 #endif
2464         .permission     = ext4_permission,
2465 };
2466
2467 const struct inode_operations ext4_special_inode_operations = {
2468         .setattr        = ext4_setattr,
2469 #ifdef CONFIG_EXT4DEV_FS_XATTR
2470         .setxattr       = generic_setxattr,
2471         .getxattr       = generic_getxattr,
2472         .listxattr      = ext4_listxattr,
2473         .removexattr    = generic_removexattr,
2474 #endif
2475         .permission     = ext4_permission,
2476 };