fs/ext4/dir.c

   1 /*
   2  *  linux/fs/ext4/dir.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/dir.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  ext4 directory handling functions
  16  *
  17  *  Big-endian to little-endian byte-swapping/bitmaps by
  18  *        David S. Miller (davem@caip.rutgers.edu), 1995
  19  *
  20  * Hash Tree Directory indexing (c) 2001  Daniel Phillips
  21  *
  22  */
  23
  24 #include <linux/fs.h>
  25 #include <linux/jbd2.h>
  26 #include <linux/buffer_head.h>
  27 #include <linux/slab.h>
  28 #include <linux/rbtree.h>
  29 #include "ext4.h"
  30
  31 static unsigned char ext4_filetype_table[] = {
  32         DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
  33 };
  34
  35 static int ext4_dx_readdir(struct file *filp,
  36                            void *dirent, filldir_t filldir);
  37
  38 static unsigned char get_dtype(struct super_block *sb, int filetype)
  39 {
  40         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE) ||
  41             (filetype >= EXT4_FT_MAX))
  42                 return DT_UNKNOWN;
  43
  44         return (ext4_filetype_table[filetype]);
  45 }
  46
  47 /**
  48  * Check if the given dir-inode refers to an htree-indexed directory
  49  * (or a directory which chould potentially get coverted to use htree
  50  * indexing).
  51  *
  52  * Return 1 if it is a dx dir, 0 if not
  53  */
  54 static int is_dx_dir(struct inode *inode)
  55 {
  56         struct super_block *sb = inode->i_sb;
  57
  58         if (EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
  59                      EXT4_FEATURE_COMPAT_DIR_INDEX) &&
  60             ((ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) ||
  61              ((inode->i_size >> sb->s_blocksize_bits) == 1)))
  62                 return 1;
  63
  64         return 0;
  65 }
  66
  67 /*
  68  * Return 0 if the directory entry is OK, and 1 if there is a problem
  69  *
  70  * Note: this is the opposite of what ext2 and ext3 historically returned...
  71  */
  72 int __ext4_check_dir_entry(const char *function, unsigned int line,
  73                            struct inode *dir, struct file *filp,
  74                            struct ext4_dir_entry_2 *de,
  75                            struct buffer_head *bh,
  76                            unsigned int offset)
  77 {
  78         const char *error_msg = NULL;
  79         const int rlen = ext4_rec_len_from_disk(de->rec_len,
  80                                                 dir->i_sb->s_blocksize);
  81
  82         if (unlikely(rlen < EXT4_DIR_REC_LEN(1)))
  83                 error_msg = "rec_len is smaller than minimal";
  84         else if (unlikely(rlen % 4 != 0))
  85                 error_msg = "rec_len % 4 != 0";
  86         else if (unlikely(rlen < EXT4_DIR_REC_LEN(de->name_len)))
  87                 error_msg = "rec_len is too small for name_len";
  88         else if (unlikely(((char *) de - bh->b_data) + rlen >
  89                           dir->i_sb->s_blocksize))
  90                 error_msg = "directory entry across blocks";
  91         else if (unlikely(le32_to_cpu(de->inode) >
  92                         le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count)))
  93                 error_msg = "inode out of bounds";
  94         else
  95                 return 0;
  96
  97         if (filp)
  98                 ext4_error_file(filp, function, line, bh->b_blocknr,
  99                                 "bad entry in directory: %s - offset=%u(%u), "
 100                                 "inode=%u, rec_len=%d, name_len=%d",
 101                                 error_msg, (unsigned) (offset % bh->b_size),
 102                                 offset, le32_to_cpu(de->inode),
 103                                 rlen, de->name_len);
 104         else
 105                 ext4_error_inode(dir, function, line, bh->b_blocknr,
 106                                 "bad entry in directory: %s - offset=%u(%u), "
 107                                 "inode=%u, rec_len=%d, name_len=%d",
 108                                 error_msg, (unsigned) (offset % bh->b_size),
 109                                 offset, le32_to_cpu(de->inode),
 110                                 rlen, de->name_len);
 111
 112         return 1;
 113 }
 114
 115 static int ext4_readdir(struct file *filp,
 116                          void *dirent, filldir_t filldir)
 117 {
 118         int error = 0;
 119         unsigned int offset;
 120         int i, stored;
 121         struct ext4_dir_entry_2 *de;
 122         int err;
 123         struct inode *inode = filp->f_path.dentry->d_inode;
 124         struct super_block *sb = inode->i_sb;
 125         int ret = 0;
 126         int dir_has_error = 0;
 127
 128         if (is_dx_dir(inode)) {
 129                 err = ext4_dx_readdir(filp, dirent, filldir);
 130                 if (err != ERR_BAD_DX_DIR) {
 131                         ret = err;
 132                         goto out;
 133                 }
 134                 /*
 135                  * We don't set the inode dirty flag since it's not
 136                  * critical that it get flushed back to the disk.
 137                  */
 138                 ext4_clear_inode_flag(filp->f_path.dentry->d_inode,
 139                                       EXT4_INODE_INDEX);
 140         }
 141         stored = 0;
 142         offset = filp->f_pos & (sb->s_blocksize - 1);
 143
 144         while (!error && !stored && filp->f_pos < inode->i_size) {
 145                 struct ext4_map_blocks map;
 146                 struct buffer_head *bh = NULL;
 147
 148                 map.m_lblk = filp->f_pos >> EXT4_BLOCK_SIZE_BITS(sb);
 149                 map.m_len = 1;
 150                 err = ext4_map_blocks(NULL, inode, &map, 0);
 151                 if (err > 0) {
 152                         pgoff_t index = map.m_pblk >>
 153                                         (PAGE_CACHE_SHIFT - inode->i_blkbits);
 154                         if (!ra_has_index(&filp->f_ra, index))
 155                                 page_cache_sync_readahead(
 156                                         sb->s_bdev->bd_inode->i_mapping,
 157                                         &filp->f_ra, filp,
 158                                         index, 1);
 159                         filp->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT;
 160                         bh = ext4_bread(NULL, inode, map.m_lblk, 0, &err);
 161                 }
 162
 163                 /*
 164                  * We ignore I/O errors on directories so users have a chance
 165                  * of recovering data when there's a bad sector
 166                  */
 167                 if (!bh) {
 168                         if (!dir_has_error) {
 169                                 EXT4_ERROR_FILE(filp, 0,
 170                                                 "directory contains a "
 171                                                 "hole at offset %llu",
 172                                            (unsigned long long) filp->f_pos);
 173                                 dir_has_error = 1;
 174                         }
 175                         /* corrupt size?  Maybe no more blocks to read */
 176                         if (filp->f_pos > inode->i_blocks << 9)
 177                                 break;
 178                         filp->f_pos += sb->s_blocksize - offset;
 179                         continue;
 180                 }
 181
 182                 /* Check the checksum */
 183                 if (!buffer_verified(bh) &&
 184                     !ext4_dirent_csum_verify(inode,
 185                                 (struct ext4_dir_entry *)bh->b_data)) {
 186                         EXT4_ERROR_FILE(filp, 0, "directory fails checksum "
 187                                         "at offset %llu",
 188                                         (unsigned long long)filp->f_pos);
 189                         filp->f_pos += sb->s_blocksize - offset;
 190                         continue;
 191                 }
 192                 set_buffer_verified(bh);
 193
 194 revalidate:
 195                 /* If the dir block has changed since the last call to
 196                  * readdir(2), then we might be pointing to an invalid
 197                  * dirent right now.  Scan from the start of the block
 198                  * to make sure. */
 199                 if (filp->f_version != inode->i_version) {
 200                         for (i = 0; i < sb->s_blocksize && i < offset; ) {
 201                                 de = (struct ext4_dir_entry_2 *)
 202                                         (bh->b_data + i);
 203                                 /* It's too expensive to do a full
 204                                  * dirent test each time round this
 205                                  * loop, but we do have to test at
 206                                  * least that it is non-zero.  A
 207                                  * failure will be detected in the
 208                                  * dirent test below. */
 209                                 if (ext4_rec_len_from_disk(de->rec_len,
 210                                         sb->s_blocksize) < EXT4_DIR_REC_LEN(1))
 211                                         break;
 212                                 i += ext4_rec_len_from_disk(de->rec_len,
 213                                                             sb->s_blocksize);
 214                         }
 215                         offset = i;
 216                         filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1))
 217                                 | offset;
 218                         filp->f_version = inode->i_version;
 219                 }
 220
 221                 while (!error && filp->f_pos < inode->i_size
 222                        && offset < sb->s_blocksize) {
 223                         de = (struct ext4_dir_entry_2 *) (bh->b_data + offset);
 224                         if (ext4_check_dir_entry(inode, filp, de,
 225                                                  bh, offset)) {
 226                                 /*
 227                                  * On error, skip the f_pos to the next block
 228                                  */
 229                                 filp->f_pos = (filp->f_pos |
 230                                                 (sb->s_blocksize - 1)) + 1;
 231                                 brelse(bh);
 232                                 ret = stored;
 233                                 goto out;
 234                         }
 235                         offset += ext4_rec_len_from_disk(de->rec_len,
 236                                         sb->s_blocksize);
 237                         if (le32_to_cpu(de->inode)) {
 238                                 /* We might block in the next section
 239                                  * if the data destination is
 240                                  * currently swapped out.  So, use a
 241                                  * version stamp to detect whether or
 242                                  * not the directory has been modified
 243                                  * during the copy operation.
 244                                  */
 245                                 u64 version = filp->f_version;
 246
 247                                 error = filldir(dirent, de->name,
 248                                                 de->name_len,
 249                                                 filp->f_pos,
 250                                                 le32_to_cpu(de->inode),
 251                                                 get_dtype(sb, de->file_type));
 252                                 if (error)
 253                                         break;
 254                                 if (version != filp->f_version)
 255                                         goto revalidate;
 256                                 stored++;
 257                         }
 258                         filp->f_pos += ext4_rec_len_from_disk(de->rec_len,
 259                                                 sb->s_blocksize);
 260                 }
 261                 offset = 0;
 262                 brelse(bh);
 263         }
 264 out:
 265         return ret;
 266 }
 267
 268 static inline int is_32bit_api(void)
 269 {
 270 #ifdef CONFIG_COMPAT
 271         return is_compat_task();
 272 #else
 273         return (BITS_PER_LONG == 32);
 274 #endif
 275 }
 276
 277 /*
 278  * These functions convert from the major/minor hash to an f_pos
 279  * value for dx directories
 280  *
 281  * Upper layer (for example NFS) should specify FMODE_32BITHASH or
 282  * FMODE_64BITHASH explicitly. On the other hand, we allow ext4 to be mounted
 283  * directly on both 32-bit and 64-bit nodes, under such case, neither
 284  * FMODE_32BITHASH nor FMODE_64BITHASH is specified.
 285  */
 286 static inline loff_t hash2pos(struct file *filp, __u32 major, __u32 minor)
 287 {
 288         if ((filp->f_mode & FMODE_32BITHASH) ||
 289             (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
 290                 return major >> 1;
 291         else
 292                 return ((__u64)(major >> 1) << 32) | (__u64)minor;
 293 }
 294
 295 static inline __u32 pos2maj_hash(struct file *filp, loff_t pos)
 296 {
 297         if ((filp->f_mode & FMODE_32BITHASH) ||
 298             (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
 299                 return (pos << 1) & 0xffffffff;
 300         else
 301                 return ((pos >> 32) << 1) & 0xffffffff;
 302 }
 303
 304 static inline __u32 pos2min_hash(struct file *filp, loff_t pos)
 305 {
 306         if ((filp->f_mode & FMODE_32BITHASH) ||
 307             (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
 308                 return 0;
 309         else
 310                 return pos & 0xffffffff;
 311 }
 312
 313 /*
 314  * Return 32- or 64-bit end-of-file for dx directories
 315  */
 316 static inline loff_t ext4_get_htree_eof(struct file *filp)
 317 {
 318         if ((filp->f_mode & FMODE_32BITHASH) ||
 319             (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
 320                 return EXT4_HTREE_EOF_32BIT;
 321         else
 322                 return EXT4_HTREE_EOF_64BIT;
 323 }
 324
 325
 326 /*
 327  * ext4_dir_llseek() based on generic_file_llseek() to handle both
 328  * non-htree and htree directories, where the "offset" is in terms
 329  * of the filename hash value instead of the byte offset.
 330  *
 331  * NOTE: offsets obtained *before* ext4_set_inode_flag(dir, EXT4_INODE_INDEX)
 332  *       will be invalid once the directory was converted into a dx directory
 333  */
 334 loff_t ext4_dir_llseek(struct file *file, loff_t offset, int origin)
 335 {
 336         struct inode *inode = file->f_mapping->host;
 337         loff_t ret = -EINVAL;
 338         int dx_dir = is_dx_dir(inode);
 339
 340         mutex_lock(&inode->i_mutex);
 341
 342         /* NOTE: relative offsets with dx directories might not work
 343          *       as expected, as it is difficult to figure out the
 344          *       correct offset between dx hashes */
 345
 346         switch (origin) {
 347         case SEEK_END:
 348                 if (unlikely(offset > 0))
 349                         goto out_err; /* not supported for directories */
 350
 351                 /* so only negative offsets are left, does that have a
 352                  * meaning for directories at all? */
 353                 if (dx_dir)
 354                         offset += ext4_get_htree_eof(file);
 355                 else
 356                         offset += inode->i_size;
 357                 break;
 358         case SEEK_CUR:
 359                 /*
 360                  * Here we special-case the lseek(fd, 0, SEEK_CUR)
 361                  * position-querying operation.  Avoid rewriting the "same"
 362                  * f_pos value back to the file because a concurrent read(),
 363                  * write() or lseek() might have altered it
 364                  */
 365                 if (offset == 0) {
 366                         offset = file->f_pos;
 367                         goto out_ok;
 368                 }
 369
 370                 offset += file->f_pos;
 371                 break;
 372         }
 373
 374         if (unlikely(offset < 0))
 375                 goto out_err;
 376
 377         if (!dx_dir) {
 378                 if (offset > inode->i_sb->s_maxbytes)
 379                         goto out_err;
 380         } else if (offset > ext4_get_htree_eof(file))
 381                 goto out_err;
 382
 383         /* Special lock needed here? */
 384         if (offset != file->f_pos) {
 385                 file->f_pos = offset;
 386                 file->f_version = 0;
 387         }
 388
 389 out_ok:
 390         ret = offset;
 391 out_err:
 392         mutex_unlock(&inode->i_mutex);
 393
 394         return ret;
 395 }
 396
 397 /*
 398  * This structure holds the nodes of the red-black tree used to store
 399  * the directory entry in hash order.
 400  */
 401 struct fname {
 402         __u32           hash;
 403         __u32           minor_hash;
 404         struct rb_node  rb_hash;
 405         struct fname    *next;
 406         __u32           inode;
 407         __u8            name_len;
 408         __u8            file_type;
 409         char            name[0];
 410 };
 411
 412 /*
 413  * This functoin implements a non-recursive way of freeing all of the
 414  * nodes in the red-black tree.
 415  */
 416 static void free_rb_tree_fname(struct rb_root *root)
 417 {
 418         struct rb_node  *n = root->rb_node;
 419         struct rb_node  *parent;
 420         struct fname    *fname;
 421
 422         while (n) {
 423                 /* Do the node's children first */
 424                 if (n->rb_left) {
 425                         n = n->rb_left;
 426                         continue;
 427                 }
 428                 if (n->rb_right) {
 429                         n = n->rb_right;
 430                         continue;
 431                 }
 432                 /*
 433                  * The node has no children; free it, and then zero
 434                  * out parent's link to it.  Finally go to the
 435                  * beginning of the loop and try to free the parent
 436                  * node.
 437                  */
 438                 parent = rb_parent(n);
 439                 fname = rb_entry(n, struct fname, rb_hash);
 440                 while (fname) {
 441                         struct fname *old = fname;
 442                         fname = fname->next;
 443                         kfree(old);
 444                 }
 445                 if (!parent)
 446                         *root = RB_ROOT;
 447                 else if (parent->rb_left == n)
 448                         parent->rb_left = NULL;
 449                 else if (parent->rb_right == n)
 450                         parent->rb_right = NULL;
 451                 n = parent;
 452         }
 453 }
 454
 455
 456 static struct dir_private_info *ext4_htree_create_dir_info(struct file *filp,
 457                                                            loff_t pos)
 458 {
 459         struct dir_private_info *p;
 460
 461         p = kzalloc(sizeof(struct dir_private_info), GFP_KERNEL);
 462         if (!p)
 463                 return NULL;
 464         p->curr_hash = pos2maj_hash(filp, pos);
 465         p->curr_minor_hash = pos2min_hash(filp, pos);
 466         return p;
 467 }
 468
 469 void ext4_htree_free_dir_info(struct dir_private_info *p)
 470 {
 471         free_rb_tree_fname(&p->root);
 472         kfree(p);
 473 }
 474
 475 /*
 476  * Given a directory entry, enter it into the fname rb tree.
 477  */
 478 int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
 479                              __u32 minor_hash,
 480                              struct ext4_dir_entry_2 *dirent)
 481 {
 482         struct rb_node **p, *parent = NULL;
 483         struct fname *fname, *new_fn;
 484         struct dir_private_info *info;
 485         int len;
 486
 487         info = dir_file->private_data;
 488         p = &info->root.rb_node;
 489
 490         /* Create and allocate the fname structure */
 491         len = sizeof(struct fname) + dirent->name_len + 1;
 492         new_fn = kzalloc(len, GFP_KERNEL);
 493         if (!new_fn)
 494                 return -ENOMEM;
 495         new_fn->hash = hash;
 496         new_fn->minor_hash = minor_hash;
 497         new_fn->inode = le32_to_cpu(dirent->inode);
 498         new_fn->name_len = dirent->name_len;
 499         new_fn->file_type = dirent->file_type;
 500         memcpy(new_fn->name, dirent->name, dirent->name_len);
 501         new_fn->name[dirent->name_len] = 0;
 502
 503         while (*p) {
 504                 parent = *p;
 505                 fname = rb_entry(parent, struct fname, rb_hash);
 506
 507                 /*
 508                  * If the hash and minor hash match up, then we put
 509                  * them on a linked list.  This rarely happens...
 510                  */
 511                 if ((new_fn->hash == fname->hash) &&
 512                     (new_fn->minor_hash == fname->minor_hash)) {
 513                         new_fn->next = fname->next;
 514                         fname->next = new_fn;
 515                         return 0;
 516                 }
 517
 518                 if (new_fn->hash < fname->hash)
 519                         p = &(*p)->rb_left;
 520                 else if (new_fn->hash > fname->hash)
 521                         p = &(*p)->rb_right;
 522                 else if (new_fn->minor_hash < fname->minor_hash)
 523                         p = &(*p)->rb_left;
 524                 else /* if (new_fn->minor_hash > fname->minor_hash) */
 525                         p = &(*p)->rb_right;
 526         }
 527
 528         rb_link_node(&new_fn->rb_hash, parent, p);
 529         rb_insert_color(&new_fn->rb_hash, &info->root);
 530         return 0;
 531 }
 532
 533
 534
 535 /*
 536  * This is a helper function for ext4_dx_readdir.  It calls filldir
 537  * for all entres on the fname linked list.  (Normally there is only
 538  * one entry on the linked list, unless there are 62 bit hash collisions.)
 539  */
 540 static int call_filldir(struct file *filp, void *dirent,
 541                         filldir_t filldir, struct fname *fname)
 542 {
 543         struct dir_private_info *info = filp->private_data;
 544         loff_t  curr_pos;
 545         struct inode *inode = filp->f_path.dentry->d_inode;
 546         struct super_block *sb;
 547         int error;
 548
 549         sb = inode->i_sb;
 550
 551         if (!fname) {
 552                 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: comm %s: "
 553                          "called with null fname?!?", __func__, __LINE__,
 554                          inode->i_ino, current->comm);
 555                 return 0;
 556         }
 557         curr_pos = hash2pos(filp, fname->hash, fname->minor_hash);
 558         while (fname) {
 559                 error = filldir(dirent, fname->name,
 560                                 fname->name_len, curr_pos,
 561                                 fname->inode,
 562                                 get_dtype(sb, fname->file_type));
 563                 if (error) {
 564                         filp->f_pos = curr_pos;
 565                         info->extra_fname = fname;
 566                         return error;
 567                 }
 568                 fname = fname->next;
 569         }
 570         return 0;
 571 }
 572
 573 static int ext4_dx_readdir(struct file *filp,
 574                          void *dirent, filldir_t filldir)
 575 {
 576         struct dir_private_info *info = filp->private_data;
 577         struct inode *inode = filp->f_path.dentry->d_inode;
 578         struct fname *fname;
 579         int     ret;
 580
 581         if (!info) {
 582                 info = ext4_htree_create_dir_info(filp, filp->f_pos);
 583                 if (!info)
 584                         return -ENOMEM;
 585                 filp->private_data = info;
 586         }
 587
 588         if (filp->f_pos == ext4_get_htree_eof(filp))
 589                 return 0;       /* EOF */
 590
 591         /* Some one has messed with f_pos; reset the world */
 592         if (info->last_pos != filp->f_pos) {
 593                 free_rb_tree_fname(&info->root);
 594                 info->curr_node = NULL;
 595                 info->extra_fname = NULL;
 596                 info->curr_hash = pos2maj_hash(filp, filp->f_pos);
 597                 info->curr_minor_hash = pos2min_hash(filp, filp->f_pos);
 598         }
 599
 600         /*
 601          * If there are any leftover names on the hash collision
 602          * chain, return them first.
 603          */
 604         if (info->extra_fname) {
 605                 if (call_filldir(filp, dirent, filldir, info->extra_fname))
 606                         goto finished;
 607                 info->extra_fname = NULL;
 608                 goto next_node;
 609         } else if (!info->curr_node)
 610                 info->curr_node = rb_first(&info->root);
 611
 612         while (1) {
 613                 /*
 614                  * Fill the rbtree if we have no more entries,
 615                  * or the inode has changed since we last read in the
 616                  * cached entries.
 617                  */
 618                 if ((!info->curr_node) ||
 619                     (filp->f_version != inode->i_version)) {
 620                         info->curr_node = NULL;
 621                         free_rb_tree_fname(&info->root);
 622                         filp->f_version = inode->i_version;
 623                         ret = ext4_htree_fill_tree(filp, info->curr_hash,
 624                                                    info->curr_minor_hash,
 625                                                    &info->next_hash);
 626                         if (ret < 0)
 627                                 return ret;
 628                         if (ret == 0) {
 629                                 filp->f_pos = ext4_get_htree_eof(filp);
 630                                 break;
 631                         }
 632                         info->curr_node = rb_first(&info->root);
 633                 }
 634
 635                 fname = rb_entry(info->curr_node, struct fname, rb_hash);
 636                 info->curr_hash = fname->hash;
 637                 info->curr_minor_hash = fname->minor_hash;
 638                 if (call_filldir(filp, dirent, filldir, fname))
 639                         break;
 640         next_node:
 641                 info->curr_node = rb_next(info->curr_node);
 642                 if (info->curr_node) {
 643                         fname = rb_entry(info->curr_node, struct fname,
 644                                          rb_hash);
 645                         info->curr_hash = fname->hash;
 646                         info->curr_minor_hash = fname->minor_hash;
 647                 } else {
 648                         if (info->next_hash == ~0) {
 649                                 filp->f_pos = ext4_get_htree_eof(filp);
 650                                 break;
 651                         }
 652                         info->curr_hash = info->next_hash;
 653                         info->curr_minor_hash = 0;
 654                 }
 655         }
 656 finished:
 657         info->last_pos = filp->f_pos;
 658         return 0;
 659 }
 660
 661 static int ext4_release_dir(struct inode *inode, struct file *filp)
 662 {
 663         if (filp->private_data)
 664                 ext4_htree_free_dir_info(filp->private_data);
 665
 666         return 0;
 667 }
 668
 669 const struct file_operations ext4_dir_operations = {
 670         .llseek         = ext4_dir_llseek,
 671         .read           = generic_read_dir,
 672         .readdir        = ext4_readdir,
 673         .unlocked_ioctl = ext4_ioctl,
 674 #ifdef CONFIG_COMPAT
 675         .compat_ioctl   = ext4_compat_ioctl,
 676 #endif
 677         .fsync          = ext4_sync_file,
 678         .release        = ext4_release_dir,
 679 };