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/buffer_head.h>
  26 #include <linux/slab.h>
  27 #include "ext4.h"
  28 #include "xattr.h"
  29
  30 static int ext4_dx_readdir(struct file *, struct dir_context *);
  31
  32 /**
  33  * Check if the given dir-inode refers to an htree-indexed directory
  34  * (or a directory which could potentially get converted to use htree
  35  * indexing).
  36  *
  37  * Return 1 if it is a dx dir, 0 if not
  38  */
  39 static int is_dx_dir(struct inode *inode)
  40 {
  41         struct super_block *sb = inode->i_sb;
  42
  43         if (EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
  44                      EXT4_FEATURE_COMPAT_DIR_INDEX) &&
  45             ((ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) ||
  46              ((inode->i_size >> sb->s_blocksize_bits) == 1) ||
  47              ext4_has_inline_data(inode)))
  48                 return 1;
  49
  50         return 0;
  51 }
  52
  53 /*
  54  * Return 0 if the directory entry is OK, and 1 if there is a problem
  55  *
  56  * Note: this is the opposite of what ext2 and ext3 historically returned...
  57  *
  58  * bh passed here can be an inode block or a dir data block, depending
  59  * on the inode inline data flag.
  60  */
  61 int __ext4_check_dir_entry(const char *function, unsigned int line,
  62                            struct inode *dir, struct file *filp,
  63                            struct ext4_dir_entry_2 *de,
  64                            struct buffer_head *bh, char *buf, int size,
  65                            unsigned int offset)
  66 {
  67         const char *error_msg = NULL;
  68         const int rlen = ext4_rec_len_from_disk(de->rec_len,
  69                                                 dir->i_sb->s_blocksize);
  70
  71         if (unlikely(rlen < EXT4_DIR_REC_LEN(1)))
  72                 error_msg = "rec_len is smaller than minimal";
  73         else if (unlikely(rlen % 4 != 0))
  74                 error_msg = "rec_len % 4 != 0";
  75         else if (unlikely(rlen < EXT4_DIR_REC_LEN(de->name_len)))
  76                 error_msg = "rec_len is too small for name_len";
  77         else if (unlikely(((char *) de - buf) + rlen > size))
  78                 error_msg = "directory entry across range";
  79         else if (unlikely(le32_to_cpu(de->inode) >
  80                         le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count)))
  81                 error_msg = "inode out of bounds";
  82         else
  83                 return 0;
  84
  85         if (filp)
  86                 ext4_error_file(filp, function, line, bh->b_blocknr,
  87                                 "bad entry in directory: %s - offset=%u(%u), "
  88                                 "inode=%u, rec_len=%d, name_len=%d",
  89                                 error_msg, (unsigned) (offset % size),
  90                                 offset, le32_to_cpu(de->inode),
  91                                 rlen, de->name_len);
  92         else
  93                 ext4_error_inode(dir, function, line, bh->b_blocknr,
  94                                 "bad entry in directory: %s - offset=%u(%u), "
  95                                 "inode=%u, rec_len=%d, name_len=%d",
  96                                 error_msg, (unsigned) (offset % size),
  97                                 offset, le32_to_cpu(de->inode),
  98                                 rlen, de->name_len);
  99
 100         return 1;
 101 }
 102
 103 static int ext4_readdir(struct file *file, struct dir_context *ctx)
 104 {
 105         unsigned int offset;
 106         int i;
 107         struct ext4_dir_entry_2 *de;
 108         int err;
 109         struct inode *inode = file_inode(file);
 110         struct super_block *sb = inode->i_sb;
 111         struct buffer_head *bh = NULL;
 112         int dir_has_error = 0;
 113         struct ext4_str fname_crypto_str = {.name = NULL, .len = 0};
 114
 115         if (is_dx_dir(inode)) {
 116                 err = ext4_dx_readdir(file, ctx);
 117                 if (err != ERR_BAD_DX_DIR) {
 118                         return err;
 119                 }
 120                 /*
 121                  * We don't set the inode dirty flag since it's not
 122                  * critical that it get flushed back to the disk.
 123                  */
 124                 ext4_clear_inode_flag(file_inode(file),
 125                                       EXT4_INODE_INDEX);
 126         }
 127
 128         if (ext4_has_inline_data(inode)) {
 129                 int has_inline_data = 1;
 130                 err = ext4_read_inline_dir(file, ctx,
 131                                            &has_inline_data);
 132                 if (has_inline_data)
 133                         return err;
 134         }
 135
 136         if (ext4_encrypted_inode(inode)) {
 137                 err = ext4_fname_crypto_alloc_buffer(inode, EXT4_NAME_LEN,
 138                                                      &fname_crypto_str);
 139                 if (err < 0)
 140                         return err;
 141         }
 142
 143         offset = ctx->pos & (sb->s_blocksize - 1);
 144
 145         while (ctx->pos < inode->i_size) {
 146                 struct ext4_map_blocks map;
 147
 148                 map.m_lblk = ctx->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(&file->f_ra, index))
 155                                 page_cache_sync_readahead(
 156                                         sb->s_bdev->bd_inode->i_mapping,
 157                                         &file->f_ra, file,
 158                                         index, 1);
 159                         file->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT;
 160                         bh = ext4_bread(NULL, inode, map.m_lblk, 0);
 161                         if (IS_ERR(bh))
 162                                 return PTR_ERR(bh);
 163                 }
 164
 165                 if (!bh) {
 166                         if (!dir_has_error) {
 167                                 EXT4_ERROR_FILE(file, 0,
 168                                                 "directory contains a "
 169                                                 "hole at offset %llu",
 170                                            (unsigned long long) ctx->pos);
 171                                 dir_has_error = 1;
 172                         }
 173                         /* corrupt size?  Maybe no more blocks to read */
 174                         if (ctx->pos > inode->i_blocks << 9)
 175                                 break;
 176                         ctx->pos += sb->s_blocksize - offset;
 177                         continue;
 178                 }
 179
 180                 /* Check the checksum */
 181                 if (!buffer_verified(bh) &&
 182                     !ext4_dirent_csum_verify(inode,
 183                                 (struct ext4_dir_entry *)bh->b_data)) {
 184                         EXT4_ERROR_FILE(file, 0, "directory fails checksum "
 185                                         "at offset %llu",
 186                                         (unsigned long long)ctx->pos);
 187                         ctx->pos += sb->s_blocksize - offset;
 188                         brelse(bh);
 189                         bh = NULL;
 190                         continue;
 191                 }
 192                 set_buffer_verified(bh);
 193
 194                 /* If the dir block has changed since the last call to
 195                  * readdir(2), then we might be pointing to an invalid
 196                  * dirent right now.  Scan from the start of the block
 197                  * to make sure. */
 198                 if (file->f_version != inode->i_version) {
 199                         for (i = 0; i < sb->s_blocksize && i < offset; ) {
 200                                 de = (struct ext4_dir_entry_2 *)
 201                                         (bh->b_data + i);
 202                                 /* It's too expensive to do a full
 203                                  * dirent test each time round this
 204                                  * loop, but we do have to test at
 205                                  * least that it is non-zero.  A
 206                                  * failure will be detected in the
 207                                  * dirent test below. */
 208                                 if (ext4_rec_len_from_disk(de->rec_len,
 209                                         sb->s_blocksize) < EXT4_DIR_REC_LEN(1))
 210                                         break;
 211                                 i += ext4_rec_len_from_disk(de->rec_len,
 212                                                             sb->s_blocksize);
 213                         }
 214                         offset = i;
 215                         ctx->pos = (ctx->pos & ~(sb->s_blocksize - 1))
 216                                 | offset;
 217                         file->f_version = inode->i_version;
 218                 }
 219
 220                 while (ctx->pos < inode->i_size
 221                        && offset < sb->s_blocksize) {
 222                         de = (struct ext4_dir_entry_2 *) (bh->b_data + offset);
 223                         if (ext4_check_dir_entry(inode, file, de, bh,
 224                                                  bh->b_data, bh->b_size,
 225                                                  offset)) {
 226                                 /*
 227                                  * On error, skip to the next block
 228                                  */
 229                                 ctx->pos = (ctx->pos |
 230                                                 (sb->s_blocksize - 1)) + 1;
 231                                 break;
 232                         }
 233                         offset += ext4_rec_len_from_disk(de->rec_len,
 234                                         sb->s_blocksize);
 235                         if (le32_to_cpu(de->inode)) {
 236                                 if (!ext4_encrypted_inode(inode)) {
 237                                         if (!dir_emit(ctx, de->name,
 238                                             de->name_len,
 239                                             le32_to_cpu(de->inode),
 240                                             get_dtype(sb, de->file_type)))
 241                                                 goto done;
 242                                 } else {
 243                                         int save_len = fname_crypto_str.len;
 244
 245                                         /* Directory is encrypted */
 246                                         err = ext4_fname_disk_to_usr(inode,
 247                                                 NULL, de, &fname_crypto_str);
 248                                         fname_crypto_str.len = save_len;
 249                                         if (err < 0)
 250                                                 goto errout;
 251                                         if (!dir_emit(ctx,
 252                                             fname_crypto_str.name, err,
 253                                             le32_to_cpu(de->inode),
 254                                             get_dtype(sb, de->file_type)))
 255                                                 goto done;
 256                                 }
 257                         }
 258                         ctx->pos += ext4_rec_len_from_disk(de->rec_len,
 259                                                 sb->s_blocksize);
 260                 }
 261                 if ((ctx->pos < inode->i_size) && !dir_relax(inode))
 262                         goto done;
 263                 brelse(bh);
 264                 bh = NULL;
 265                 offset = 0;
 266         }
 267 done:
 268         err = 0;
 269 errout:
 270 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 271         ext4_fname_crypto_free_buffer(&fname_crypto_str);
 272 #endif
 273         brelse(bh);
 274         return err;
 275 }
 276
 277 static inline int is_32bit_api(void)
 278 {
 279 #ifdef CONFIG_COMPAT
 280         return is_compat_task();
 281 #else
 282         return (BITS_PER_LONG == 32);
 283 #endif
 284 }
 285
 286 /*
 287  * These functions convert from the major/minor hash to an f_pos
 288  * value for dx directories
 289  *
 290  * Upper layer (for example NFS) should specify FMODE_32BITHASH or
 291  * FMODE_64BITHASH explicitly. On the other hand, we allow ext4 to be mounted
 292  * directly on both 32-bit and 64-bit nodes, under such case, neither
 293  * FMODE_32BITHASH nor FMODE_64BITHASH is specified.
 294  */
 295 static inline loff_t hash2pos(struct file *filp, __u32 major, __u32 minor)
 296 {
 297         if ((filp->f_mode & FMODE_32BITHASH) ||
 298             (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
 299                 return major >> 1;
 300         else
 301                 return ((__u64)(major >> 1) << 32) | (__u64)minor;
 302 }
 303
 304 static inline __u32 pos2maj_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 (pos << 1) & 0xffffffff;
 309         else
 310                 return ((pos >> 32) << 1) & 0xffffffff;
 311 }
 312
 313 static inline __u32 pos2min_hash(struct file *filp, loff_t pos)
 314 {
 315         if ((filp->f_mode & FMODE_32BITHASH) ||
 316             (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
 317                 return 0;
 318         else
 319                 return pos & 0xffffffff;
 320 }
 321
 322 /*
 323  * Return 32- or 64-bit end-of-file for dx directories
 324  */
 325 static inline loff_t ext4_get_htree_eof(struct file *filp)
 326 {
 327         if ((filp->f_mode & FMODE_32BITHASH) ||
 328             (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
 329                 return EXT4_HTREE_EOF_32BIT;
 330         else
 331                 return EXT4_HTREE_EOF_64BIT;
 332 }
 333
 334
 335 /*
 336  * ext4_dir_llseek() calls generic_file_llseek_size to handle htree
 337  * directories, where the "offset" is in terms of the filename hash
 338  * value instead of the byte offset.
 339  *
 340  * Because we may return a 64-bit hash that is well beyond offset limits,
 341  * we need to pass the max hash as the maximum allowable offset in
 342  * the htree directory case.
 343  *
 344  * For non-htree, ext4_llseek already chooses the proper max offset.
 345  */
 346 static loff_t ext4_dir_llseek(struct file *file, loff_t offset, int whence)
 347 {
 348         struct inode *inode = file->f_mapping->host;
 349         int dx_dir = is_dx_dir(inode);
 350         loff_t htree_max = ext4_get_htree_eof(file);
 351
 352         if (likely(dx_dir))
 353                 return generic_file_llseek_size(file, offset, whence,
 354                                                     htree_max, htree_max);
 355         else
 356                 return ext4_llseek(file, offset, whence);
 357 }
 358
 359 /*
 360  * This structure holds the nodes of the red-black tree used to store
 361  * the directory entry in hash order.
 362  */
 363 struct fname {
 364         __u32           hash;
 365         __u32           minor_hash;
 366         struct rb_node  rb_hash;
 367         struct fname    *next;
 368         __u32           inode;
 369         __u8            name_len;
 370         __u8            file_type;
 371         char            name[0];
 372 };
 373
 374 /*
 375  * This functoin implements a non-recursive way of freeing all of the
 376  * nodes in the red-black tree.
 377  */
 378 static void free_rb_tree_fname(struct rb_root *root)
 379 {
 380         struct fname *fname, *next;
 381
 382         rbtree_postorder_for_each_entry_safe(fname, next, root, rb_hash)
 383                 while (fname) {
 384                         struct fname *old = fname;
 385                         fname = fname->next;
 386                         kfree(old);
 387                 }
 388
 389         *root = RB_ROOT;
 390 }
 391
 392
 393 static struct dir_private_info *ext4_htree_create_dir_info(struct file *filp,
 394                                                            loff_t pos)
 395 {
 396         struct dir_private_info *p;
 397
 398         p = kzalloc(sizeof(struct dir_private_info), GFP_KERNEL);
 399         if (!p)
 400                 return NULL;
 401         p->curr_hash = pos2maj_hash(filp, pos);
 402         p->curr_minor_hash = pos2min_hash(filp, pos);
 403         return p;
 404 }
 405
 406 void ext4_htree_free_dir_info(struct dir_private_info *p)
 407 {
 408         free_rb_tree_fname(&p->root);
 409         kfree(p);
 410 }
 411
 412 /*
 413  * Given a directory entry, enter it into the fname rb tree.
 414  *
 415  * When filename encryption is enabled, the dirent will hold the
 416  * encrypted filename, while the htree will hold decrypted filename.
 417  * The decrypted filename is passed in via ent_name.  parameter.
 418  */
 419 int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
 420                              __u32 minor_hash,
 421                             struct ext4_dir_entry_2 *dirent,
 422                             struct ext4_str *ent_name)
 423 {
 424         struct rb_node **p, *parent = NULL;
 425         struct fname *fname, *new_fn;
 426         struct dir_private_info *info;
 427         int len;
 428
 429         info = dir_file->private_data;
 430         p = &info->root.rb_node;
 431
 432         /* Create and allocate the fname structure */
 433         len = sizeof(struct fname) + ent_name->len + 1;
 434         new_fn = kzalloc(len, GFP_KERNEL);
 435         if (!new_fn)
 436                 return -ENOMEM;
 437         new_fn->hash = hash;
 438         new_fn->minor_hash = minor_hash;
 439         new_fn->inode = le32_to_cpu(dirent->inode);
 440         new_fn->name_len = ent_name->len;
 441         new_fn->file_type = dirent->file_type;
 442         memcpy(new_fn->name, ent_name->name, ent_name->len);
 443         new_fn->name[ent_name->len] = 0;
 444
 445         while (*p) {
 446                 parent = *p;
 447                 fname = rb_entry(parent, struct fname, rb_hash);
 448
 449                 /*
 450                  * If the hash and minor hash match up, then we put
 451                  * them on a linked list.  This rarely happens...
 452                  */
 453                 if ((new_fn->hash == fname->hash) &&
 454                     (new_fn->minor_hash == fname->minor_hash)) {
 455                         new_fn->next = fname->next;
 456                         fname->next = new_fn;
 457                         return 0;
 458                 }
 459
 460                 if (new_fn->hash < fname->hash)
 461                         p = &(*p)->rb_left;
 462                 else if (new_fn->hash > fname->hash)
 463                         p = &(*p)->rb_right;
 464                 else if (new_fn->minor_hash < fname->minor_hash)
 465                         p = &(*p)->rb_left;
 466                 else /* if (new_fn->minor_hash > fname->minor_hash) */
 467                         p = &(*p)->rb_right;
 468         }
 469
 470         rb_link_node(&new_fn->rb_hash, parent, p);
 471         rb_insert_color(&new_fn->rb_hash, &info->root);
 472         return 0;
 473 }
 474
 475
 476
 477 /*
 478  * This is a helper function for ext4_dx_readdir.  It calls filldir
 479  * for all entres on the fname linked list.  (Normally there is only
 480  * one entry on the linked list, unless there are 62 bit hash collisions.)
 481  */
 482 static int call_filldir(struct file *file, struct dir_context *ctx,
 483                         struct fname *fname)
 484 {
 485         struct dir_private_info *info = file->private_data;
 486         struct inode *inode = file_inode(file);
 487         struct super_block *sb = inode->i_sb;
 488
 489         if (!fname) {
 490                 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: comm %s: "
 491                          "called with null fname?!?", __func__, __LINE__,
 492                          inode->i_ino, current->comm);
 493                 return 0;
 494         }
 495         ctx->pos = hash2pos(file, fname->hash, fname->minor_hash);
 496         while (fname) {
 497                 if (!dir_emit(ctx, fname->name,
 498                                 fname->name_len,
 499                                 fname->inode,
 500                                 get_dtype(sb, fname->file_type))) {
 501                         info->extra_fname = fname;
 502                         return 1;
 503                 }
 504                 fname = fname->next;
 505         }
 506         return 0;
 507 }
 508
 509 static int ext4_dx_readdir(struct file *file, struct dir_context *ctx)
 510 {
 511         struct dir_private_info *info = file->private_data;
 512         struct inode *inode = file_inode(file);
 513         struct fname *fname;
 514         int     ret;
 515
 516         if (!info) {
 517                 info = ext4_htree_create_dir_info(file, ctx->pos);
 518                 if (!info)
 519                         return -ENOMEM;
 520                 file->private_data = info;
 521         }
 522
 523         if (ctx->pos == ext4_get_htree_eof(file))
 524                 return 0;       /* EOF */
 525
 526         /* Some one has messed with f_pos; reset the world */
 527         if (info->last_pos != ctx->pos) {
 528                 free_rb_tree_fname(&info->root);
 529                 info->curr_node = NULL;
 530                 info->extra_fname = NULL;
 531                 info->curr_hash = pos2maj_hash(file, ctx->pos);
 532                 info->curr_minor_hash = pos2min_hash(file, ctx->pos);
 533         }
 534
 535         /*
 536          * If there are any leftover names on the hash collision
 537          * chain, return them first.
 538          */
 539         if (info->extra_fname) {
 540                 if (call_filldir(file, ctx, info->extra_fname))
 541                         goto finished;
 542                 info->extra_fname = NULL;
 543                 goto next_node;
 544         } else if (!info->curr_node)
 545                 info->curr_node = rb_first(&info->root);
 546
 547         while (1) {
 548                 /*
 549                  * Fill the rbtree if we have no more entries,
 550                  * or the inode has changed since we last read in the
 551                  * cached entries.
 552                  */
 553                 if ((!info->curr_node) ||
 554                     (file->f_version != inode->i_version)) {
 555                         info->curr_node = NULL;
 556                         free_rb_tree_fname(&info->root);
 557                         file->f_version = inode->i_version;
 558                         ret = ext4_htree_fill_tree(file, info->curr_hash,
 559                                                    info->curr_minor_hash,
 560                                                    &info->next_hash);
 561                         if (ret < 0)
 562                                 return ret;
 563                         if (ret == 0) {
 564                                 ctx->pos = ext4_get_htree_eof(file);
 565                                 break;
 566                         }
 567                         info->curr_node = rb_first(&info->root);
 568                 }
 569
 570                 fname = rb_entry(info->curr_node, struct fname, rb_hash);
 571                 info->curr_hash = fname->hash;
 572                 info->curr_minor_hash = fname->minor_hash;
 573                 if (call_filldir(file, ctx, fname))
 574                         break;
 575         next_node:
 576                 info->curr_node = rb_next(info->curr_node);
 577                 if (info->curr_node) {
 578                         fname = rb_entry(info->curr_node, struct fname,
 579                                          rb_hash);
 580                         info->curr_hash = fname->hash;
 581                         info->curr_minor_hash = fname->minor_hash;
 582                 } else {
 583                         if (info->next_hash == ~0) {
 584                                 ctx->pos = ext4_get_htree_eof(file);
 585                                 break;
 586                         }
 587                         info->curr_hash = info->next_hash;
 588                         info->curr_minor_hash = 0;
 589                 }
 590         }
 591 finished:
 592         info->last_pos = ctx->pos;
 593         return 0;
 594 }
 595
 596 static int ext4_dir_open(struct inode * inode, struct file * filp)
 597 {
 598         if (ext4_encrypted_inode(inode))
 599                 return ext4_get_encryption_info(inode) ? -EACCES : 0;
 600         return 0;
 601 }
 602
 603 static int ext4_release_dir(struct inode *inode, struct file *filp)
 604 {
 605         if (filp->private_data)
 606                 ext4_htree_free_dir_info(filp->private_data);
 607
 608         return 0;
 609 }
 610
 611 int ext4_check_all_de(struct inode *dir, struct buffer_head *bh, void *buf,
 612                       int buf_size)
 613 {
 614         struct ext4_dir_entry_2 *de;
 615         int nlen, rlen;
 616         unsigned int offset = 0;
 617         char *top;
 618
 619         de = (struct ext4_dir_entry_2 *)buf;
 620         top = buf + buf_size;
 621         while ((char *) de < top) {
 622                 if (ext4_check_dir_entry(dir, NULL, de, bh,
 623                                          buf, buf_size, offset))
 624                         return -EIO;
 625                 nlen = EXT4_DIR_REC_LEN(de->name_len);
 626                 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
 627                 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
 628                 offset += rlen;
 629         }
 630         if ((char *) de > top)
 631                 return -EIO;
 632
 633         return 0;
 634 }
 635
 636 const struct file_operations ext4_dir_operations = {
 637         .llseek         = ext4_dir_llseek,
 638         .read           = generic_read_dir,
 639         .iterate        = ext4_readdir,
 640         .unlocked_ioctl = ext4_ioctl,
 641 #ifdef CONFIG_COMPAT
 642         .compat_ioctl   = ext4_compat_ioctl,
 643 #endif
 644         .fsync          = ext4_sync_file,
 645         .open           = ext4_dir_open,
 646         .release        = ext4_release_dir,
 647 };