lib/ext2fs/inode.c

   1 /*
   2  * inode.c --- utility routines to read and write inodes
   3  *
   4  * Copyright (C) 1993, 1994, 1995, 1996, 1997 Theodore Ts'o.
   5  *
   6  * %Begin-Header%
   7  * This file may be redistributed under the terms of the GNU Public
   8  * License.
   9  * %End-Header%
  10  */
  11
  12 #include <stdio.h>
  13 #include <string.h>
  14 #if HAVE_UNISTD_H
  15 #include <unistd.h>
  16 #endif
  17 #include <stdlib.h>
  18 #if HAVE_SYS_STAT_H
  19 #include <sys/stat.h>
  20 #endif
  21 #if HAVE_SYS_TYPES_H
  22 #include <sys/types.h>
  23 #endif
  24
  25 #include <linux/ext2_fs.h>
  26
  27 #include "ext2fsP.h"
  28
  29 struct ext2_struct_inode_scan {
  30         errcode_t               magic;
  31         ext2_filsys             fs;
  32         ino_t                   current_inode;
  33         blk_t                   current_block;
  34         dgrp_t                  current_group;
  35         ino_t                   inodes_left;
  36         blk_t                   blocks_left;
  37         dgrp_t                  groups_left;
  38         blk_t                   inode_buffer_blocks;
  39         char *                  inode_buffer;
  40         int                     inode_size;
  41         char *                  ptr;
  42         int                     bytes_left;
  43         char                    *temp_buffer;
  44         errcode_t               (*done_group)(ext2_filsys fs,
  45                                               ext2_inode_scan scan,
  46                                               dgrp_t group,
  47                                               void * private);
  48         void *                  done_group_data;
  49         int                     bad_block_ptr;
  50         int                     scan_flags;
  51         int                     reserved[6];
  52 };
  53
  54 static errcode_t create_icache(ext2_filsys fs)
  55 {
  56         int     i;
  57
  58         if (fs->icache)
  59                 return 0;
  60         fs->icache = malloc(sizeof(struct ext2_inode_cache));
  61         memset(fs->icache, 0, sizeof(struct ext2_inode_cache));
  62         fs->icache->buffer = malloc(fs->blocksize);
  63         if (!fs->icache->buffer) {
  64                 free(fs->icache);
  65                 return EXT2_NO_MEMORY;
  66         }
  67         fs->icache->buffer_blk = 0;
  68         fs->icache->cache_last = -1;
  69         fs->icache->cache_size = 4;
  70         fs->icache->refcount = 1;
  71         fs->icache->cache = malloc(sizeof(struct ext2_inode_cache_ent)
  72                                    * fs->icache->cache_size);
  73         if (!fs->icache->cache) {
  74                 free(fs->icache->buffer);
  75                 free(fs->icache);
  76                 return EXT2_NO_MEMORY;
  77         }
  78         for (i=0; i < fs->icache->cache_size; i++)
  79                 fs->icache->cache[i].ino = 0;
  80         return 0;
  81 }
  82
  83 errcode_t ext2fs_open_inode_scan(ext2_filsys fs, int buffer_blocks,
  84                                  ext2_inode_scan *ret_scan)
  85 {
  86         ext2_inode_scan scan;
  87         errcode_t       retval;
  88         errcode_t (*save_get_blocks)(ext2_filsys f, ino_t ino, blk_t *blocks);
  89
  90         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
  91
  92         /*
  93          * If fs->badblocks isn't set, then set it --- since the inode
  94          * scanning functions require it.
  95          */
  96         if (fs->badblocks == 0) {
  97                 /*
  98                  * Temporarly save fs->get_blocks and set it to zero,
  99                  * for compatibility with old e2fsck's.
 100                  */
 101                 save_get_blocks = fs->get_blocks;
 102                 fs->get_blocks = 0;
 103                 retval = ext2fs_read_bb_inode(fs, &fs->badblocks);
 104                 if (retval && fs->badblocks) {
 105                         badblocks_list_free(fs->badblocks);
 106                         fs->badblocks = 0;
 107                 }
 108                 fs->get_blocks = save_get_blocks;
 109         }
 110
 111         scan = (ext2_inode_scan) malloc(sizeof(struct ext2_struct_inode_scan));
 112         if (!scan)
 113                 return EXT2_NO_MEMORY;
 114         memset(scan, 0, sizeof(struct ext2_struct_inode_scan));
 115
 116         scan->magic = EXT2_ET_MAGIC_INODE_SCAN;
 117         scan->fs = fs;
 118         scan->inode_size = EXT2_INODE_SIZE(fs->super);
 119         scan->bytes_left = 0;
 120         scan->current_group = -1;
 121         scan->inode_buffer_blocks = buffer_blocks ? buffer_blocks : 8;
 122         scan->groups_left = fs->group_desc_count;
 123         scan->inode_buffer = malloc((size_t) (scan->inode_buffer_blocks *
 124                                               fs->blocksize));
 125         scan->done_group = 0;
 126         scan->done_group_data = 0;
 127         scan->bad_block_ptr = 0;
 128         if (!scan->inode_buffer) {
 129                 free(scan);
 130                 return EXT2_NO_MEMORY;
 131         }
 132         scan->temp_buffer = malloc(scan->inode_size);
 133         if (!scan->temp_buffer) {
 134                 free(scan->inode_buffer);
 135                 free(scan);
 136                 return EXT2_NO_MEMORY;
 137         }
 138         if (scan->fs->badblocks && scan->fs->badblocks->num)
 139                 scan->scan_flags |= EXT2_SF_CHK_BADBLOCKS;
 140         *ret_scan = scan;
 141         return 0;
 142 }
 143
 144 void ext2fs_close_inode_scan(ext2_inode_scan scan)
 145 {
 146         if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
 147                 return;
 148
 149         free(scan->inode_buffer);
 150         scan->inode_buffer = NULL;
 151         free(scan->temp_buffer);
 152         scan->temp_buffer = NULL;
 153         free(scan);
 154         return;
 155 }
 156
 157 void ext2fs_set_inode_callback(ext2_inode_scan scan,
 158                                errcode_t (*done_group)(ext2_filsys fs,
 159                                                        ext2_inode_scan scan,
 160                                                        dgrp_t group,
 161                                                        void * private),
 162                                void *done_group_data)
 163 {
 164         if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
 165                 return;
 166
 167         scan->done_group = done_group;
 168         scan->done_group_data = done_group_data;
 169 }
 170
 171 int ext2fs_inode_scan_flags(ext2_inode_scan scan, int set_flags,
 172                             int clear_flags)
 173 {
 174         int     old_flags;
 175
 176         if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
 177                 return 0;
 178
 179         old_flags = scan->scan_flags;
 180         scan->scan_flags &= ~clear_flags;
 181         scan->scan_flags |= set_flags;
 182         return old_flags;
 183 }
 184
 185 /*
 186  * This function is called by ext2fs_get_next_inode when it needs to
 187  * get ready to read in a new blockgroup.
 188  */
 189 static errcode_t get_next_blockgroup(ext2_inode_scan scan)
 190 {
 191         scan->current_group++;
 192         scan->groups_left--;
 193
 194         scan->current_block = scan->fs->
 195                 group_desc[scan->current_group].bg_inode_table;
 196
 197         scan->bytes_left = 0;
 198         scan->inodes_left = EXT2_INODES_PER_GROUP(scan->fs->super);
 199         scan->blocks_left = scan->fs->inode_blocks_per_group;
 200         return 0;
 201 }
 202
 203 errcode_t ext2fs_inode_scan_goto_blockgroup(ext2_inode_scan scan,
 204                                             int group)
 205 {
 206         scan->current_group = group - 1;
 207         scan->groups_left = scan->fs->group_desc_count - group;
 208         scan->current_inode = group * EXT2_INODES_PER_GROUP(scan->fs->super);
 209         return get_next_blockgroup(scan);
 210 }
 211
 212 /*
 213  * This function is called by get_next_blocks() to check for bad
 214  * blocks in the inode table.
 215  *
 216  * This function assumes that badblocks_list->list is sorted in
 217  * increasing order.
 218  */
 219 static errcode_t check_for_inode_bad_blocks(ext2_inode_scan scan,
 220                                             blk_t *num_blocks)
 221 {
 222         blk_t   blk = scan->current_block;
 223         badblocks_list  bb = scan->fs->badblocks;
 224
 225         /*
 226          * If the inode table is missing, then obviously there are no
 227          * bad blocks.  :-)
 228          */
 229         if (blk == 0)
 230                 return 0;
 231
 232         /*
 233          * If the current block is greater than the bad block listed
 234          * in the bad block list, then advance the pointer until this
 235          * is no longer the case.  If we run out of bad blocks, then
 236          * we don't need to do any more checking!
 237          */
 238         while (blk > bb->list[scan->bad_block_ptr]) {
 239                 if (++scan->bad_block_ptr >= bb->num) {
 240                         scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS;
 241                         return 0;
 242                 }
 243         }
 244
 245         /*
 246          * If the current block is equal to the bad block listed in
 247          * the bad block list, then handle that one block specially.
 248          * (We could try to handle runs of bad blocks, but that
 249          * only increases CPU efficiency by a small amount, at the
 250          * expense of a huge expense of code complexity, and for an
 251          * uncommon case at that.)
 252          */
 253         if (blk == bb->list[scan->bad_block_ptr]) {
 254                 scan->scan_flags |= EXT2_SF_BAD_INODE_BLK;
 255                 *num_blocks = 1;
 256                 if (++scan->bad_block_ptr >= bb->num)
 257                         scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS;
 258                 return 0;
 259         }
 260
 261         /*
 262          * If there is a bad block in the range that we're about to
 263          * read in, adjust the number of blocks to read so that we we
 264          * don't read in the bad block.  (Then the next block to read
 265          * will be the bad block, which is handled in the above case.)
 266          */
 267         if ((blk + *num_blocks) > bb->list[scan->bad_block_ptr])
 268                 *num_blocks = (int) (bb->list[scan->bad_block_ptr] - blk);
 269
 270         return 0;
 271 }
 272
 273 /*
 274  * This function is called by ext2fs_get_next_inode when it needs to
 275  * read in more blocks from the current blockgroup's inode table.
 276  */
 277 static errcode_t get_next_blocks(ext2_inode_scan scan)
 278 {
 279         blk_t           num_blocks;
 280         errcode_t       retval;
 281
 282         /*
 283          * Figure out how many blocks to read; we read at most
 284          * inode_buffer_blocks, and perhaps less if there aren't that
 285          * many blocks left to read.
 286          */
 287         num_blocks = scan->inode_buffer_blocks;
 288         if (num_blocks > scan->blocks_left)
 289                 num_blocks = scan->blocks_left;
 290
 291         /*
 292          * If the past block "read" was a bad block, then mark the
 293          * left-over extra bytes as also being bad.
 294          */
 295         if (scan->scan_flags & EXT2_SF_BAD_INODE_BLK) {
 296                 if (scan->bytes_left)
 297                         scan->scan_flags |= EXT2_SF_BAD_EXTRA_BYTES;
 298                 scan->scan_flags &= ~EXT2_SF_BAD_INODE_BLK;
 299         }
 300
 301         /*
 302          * Do inode bad block processing, if necessary.
 303          */
 304         if (scan->scan_flags & EXT2_SF_CHK_BADBLOCKS) {
 305                 retval = check_for_inode_bad_blocks(scan, &num_blocks);
 306                 if (retval)
 307                         return retval;
 308         }
 309
 310         if ((scan->scan_flags & EXT2_SF_BAD_INODE_BLK) ||
 311             (scan->current_block == 0)) {
 312                 memset(scan->inode_buffer, 0,
 313                        (size_t) num_blocks * scan->fs->blocksize);
 314         } else {
 315                 retval = io_channel_read_blk(scan->fs->io,
 316                                              scan->current_block,
 317                                              (int) num_blocks,
 318                                              scan->inode_buffer);
 319                 if (retval)
 320                         return EXT2_ET_NEXT_INODE_READ;
 321         }
 322         scan->ptr = scan->inode_buffer;
 323         scan->bytes_left = num_blocks * scan->fs->blocksize;
 324
 325         scan->blocks_left -= num_blocks;
 326         if (scan->current_block)
 327                 scan->current_block += num_blocks;
 328         return 0;
 329 }
 330
 331 errcode_t ext2fs_get_next_inode(ext2_inode_scan scan, ino_t *ino,
 332                                 struct ext2_inode *inode)
 333 {
 334         errcode_t       retval;
 335         int             extra_bytes = 0;
 336
 337         EXT2_CHECK_MAGIC(scan, EXT2_ET_MAGIC_INODE_SCAN);
 338
 339         /*
 340          * Do we need to start reading a new block group?
 341          */
 342         if (scan->inodes_left <= 0) {
 343         retry:
 344                 if (scan->done_group) {
 345                         retval = (scan->done_group)
 346                                 (scan->fs, scan, scan->current_group,
 347                                  scan->done_group_data);
 348                         if (retval)
 349                                 return retval;
 350                 }
 351                 if (scan->groups_left <= 0) {
 352                         *ino = 0;
 353                         return 0;
 354                 }
 355                 retval = get_next_blockgroup(scan);
 356                 if (retval)
 357                         return retval;
 358                 if (scan->current_block == 0) {
 359                         if (scan->scan_flags & EXT2_SF_SKIP_MISSING_ITABLE) {
 360                                 goto retry;
 361                         } else
 362                                 return EXT2_ET_MISSING_INODE_TABLE;
 363                 }
 364         }
 365
 366         /*
 367          * Have we run out of space in the inode buffer?  If so, we
 368          * need to read in more blocks.
 369          */
 370         if (scan->bytes_left < scan->inode_size) {
 371                 memcpy(scan->temp_buffer, scan->ptr, scan->bytes_left);
 372                 extra_bytes = scan->bytes_left;
 373
 374                 retval = get_next_blocks(scan);
 375                 if (retval)
 376                         return retval;
 377         }
 378
 379         retval = 0;
 380         if (extra_bytes) {
 381                 memcpy(scan->temp_buffer+extra_bytes, scan->ptr,
 382                        scan->inode_size - extra_bytes);
 383                 scan->ptr += scan->inode_size - extra_bytes;
 384                 scan->bytes_left -= scan->inode_size - extra_bytes;
 385
 386                 if ((scan->fs->flags & EXT2_FLAG_SWAP_BYTES) ||
 387                     (scan->fs->flags & EXT2_FLAG_SWAP_BYTES_READ))
 388                         ext2fs_swap_inode(scan->fs, inode,
 389                                  (struct ext2_inode *) scan->temp_buffer, 0);
 390                 else
 391                         *inode = *((struct ext2_inode *) scan->temp_buffer);
 392                 if (scan->scan_flags & EXT2_SF_BAD_EXTRA_BYTES)
 393                         retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE;
 394                 scan->scan_flags &= ~EXT2_SF_BAD_EXTRA_BYTES;
 395         } else {
 396                 if ((scan->fs->flags & EXT2_FLAG_SWAP_BYTES) ||
 397                     (scan->fs->flags & EXT2_FLAG_SWAP_BYTES_READ))
 398                         ext2fs_swap_inode(scan->fs, inode,
 399                                  (struct ext2_inode *) scan->ptr, 0);
 400                 else
 401                         *inode = *((struct ext2_inode *) scan->ptr);
 402                 scan->ptr += scan->inode_size;
 403                 scan->bytes_left -= scan->inode_size;
 404                 if (scan->scan_flags & EXT2_SF_BAD_INODE_BLK)
 405                         retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE;
 406         }
 407
 408         scan->inodes_left--;
 409         scan->current_inode++;
 410         *ino = scan->current_inode;
 411         return retval;
 412 }
 413
 414 /*
 415  * Functions to read and write a single inode.
 416  */
 417 errcode_t ext2fs_read_inode (ext2_filsys fs, ino_t ino,
 418                              struct ext2_inode * inode)
 419 {
 420         unsigned long   group, block, block_nr, offset;
 421         char            *ptr;
 422         errcode_t       retval;
 423         int             clen, length, i;
 424
 425         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 426
 427         /* Check to see if user has an override function */
 428         if (fs->read_inode) {
 429                 retval = (fs->read_inode)(fs, ino, inode);
 430                 if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
 431                         return retval;
 432         }
 433         /* Create inode cache if not present */
 434         if (!fs->icache) {
 435                 retval = create_icache(fs);
 436                 if (retval)
 437                         return retval;
 438         }
 439         /* Check to see if it's in the inode cache */
 440         for (i=0; i < fs->icache->cache_size; i++) {
 441                 if (fs->icache->cache[i].ino == ino) {
 442                         *inode = fs->icache->cache[i].inode;
 443                         return 0;
 444                 }
 445         }
 446         if (ino > fs->super->s_inodes_count)
 447                 return EXT2_ET_BAD_INODE_NUM;
 448         group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super);
 449         offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) *
 450                 EXT2_INODE_SIZE(fs->super);
 451         block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super);
 452         if (!fs->group_desc[(unsigned)group].bg_inode_table)
 453                 return EXT2_ET_MISSING_INODE_TABLE;
 454         block_nr = fs->group_desc[(unsigned)group].bg_inode_table + block;
 455         if (block_nr != fs->icache->buffer_blk) {
 456                 retval = io_channel_read_blk(fs->io, block_nr, 1,
 457                                              fs->icache->buffer);
 458                 if (retval)
 459                         return retval;
 460                 fs->icache->buffer_blk = block_nr;
 461         }
 462         offset &= (EXT2_BLOCK_SIZE(fs->super) - 1);
 463         ptr = ((char *) fs->icache->buffer) + (unsigned) offset;
 464
 465         memset(inode, 0, sizeof(struct ext2_inode));
 466         length = EXT2_INODE_SIZE(fs->super);
 467         if (length > sizeof(struct ext2_inode))
 468                 length = sizeof(struct ext2_inode);
 469
 470         if ((offset + length) > EXT2_BLOCK_SIZE(fs->super)) {
 471                 clen = (int) (EXT2_BLOCK_SIZE(fs->super) - offset);
 472                 memcpy((char *) inode, ptr, clen);
 473                 length -= clen;
 474
 475                 retval = io_channel_read_blk(fs->io, block_nr+1, 1,
 476                                              fs->icache->buffer);
 477                 if (retval) {
 478                         fs->icache->buffer_blk = 0;
 479                         return retval;
 480                 }
 481                 fs->icache->buffer_blk = block_nr+1;
 482
 483                 memcpy(((char *) inode) + clen,
 484                        fs->icache->buffer, length);
 485         } else
 486                 memcpy((char *) inode, ptr, length);
 487
 488         if ((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
 489             (fs->flags & EXT2_FLAG_SWAP_BYTES_READ))
 490                 ext2fs_swap_inode(fs, inode, inode, 0);
 491
 492         /* Update the inode cache */
 493         fs->icache->cache_last = (fs->icache->cache_last + 1) %
 494                 fs->icache->cache_size;
 495         fs->icache->cache[fs->icache->cache_last].ino = ino;
 496         fs->icache->cache[fs->icache->cache_last].inode = *inode;
 497
 498         return 0;
 499 }
 500
 501 errcode_t ext2fs_write_inode(ext2_filsys fs, ino_t ino,
 502                              struct ext2_inode * inode)
 503 {
 504         unsigned long group, block, block_nr, offset;
 505         errcode_t       retval;
 506         struct ext2_inode temp_inode;
 507         char *ptr;
 508         int clen, length, i;
 509
 510         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 511
 512         /* Check to see if user provided an override function */
 513         if (fs->write_inode) {
 514                 retval = (fs->write_inode)(fs, ino, inode);
 515                 if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
 516                         return retval;
 517         }
 518
 519         /* Check to see if the inode cache needs to be updated */
 520         if (fs->icache) {
 521                 for (i=0; i < fs->icache->cache_size; i++) {
 522                         if (fs->icache->cache[i].ino == ino) {
 523                                 fs->icache->cache[i].inode = *inode;
 524                                 break;
 525                         }
 526                 }
 527         } else {
 528                 retval = create_icache(fs);
 529                 if (retval)
 530                         return retval;
 531         }
 532
 533         if (!(fs->flags & EXT2_FLAG_RW))
 534                 return EXT2_ET_RO_FILSYS;
 535
 536         if (ino > fs->super->s_inodes_count)
 537                 return EXT2_ET_BAD_INODE_NUM;
 538
 539         if ((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
 540             (fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE))
 541                 ext2fs_swap_inode(fs, &temp_inode, inode, 1);
 542         else
 543                 memcpy(&temp_inode, inode, sizeof(struct ext2_inode));
 544
 545         group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super);
 546         offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) *
 547                 EXT2_INODE_SIZE(fs->super);
 548         block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super);
 549         if (!fs->group_desc[(unsigned) group].bg_inode_table)
 550                 return EXT2_ET_MISSING_INODE_TABLE;
 551         block_nr = fs->group_desc[(unsigned) group].bg_inode_table + block;
 552         offset &= (EXT2_BLOCK_SIZE(fs->super) - 1);
 553         ptr = (char *) fs->icache->buffer + (unsigned) offset;
 554
 555         length = EXT2_INODE_SIZE(fs->super);
 556         clen = length;
 557         if (length > sizeof(struct ext2_inode))
 558                 length = sizeof(struct ext2_inode);
 559
 560         if (fs->icache->buffer_blk != block_nr) {
 561                 retval = io_channel_read_blk(fs->io, block_nr, 1,
 562                                              fs->icache->buffer);
 563                 if (retval)
 564                         return retval;
 565                 fs->icache->buffer_blk = block_nr;
 566         }
 567
 568         if ((offset + length) > EXT2_BLOCK_SIZE(fs->super)) {
 569                 clen = (int) (EXT2_BLOCK_SIZE(fs->super) - offset);
 570                 length -= clen;
 571         } else {
 572                 length = 0;
 573         }
 574         memcpy(ptr, &temp_inode, clen);
 575         retval = io_channel_write_blk(fs->io, block_nr, 1, fs->icache->buffer);
 576         if (retval)
 577                 return retval;
 578
 579         if (length) {
 580                 retval = io_channel_read_blk(fs->io, ++block_nr, 1,
 581                                              fs->icache->buffer);
 582                 if (retval) {
 583                         fs->icache->buffer_blk = 0;
 584                         return retval;
 585                 }
 586                 fs->icache->buffer_blk = block_nr;
 587                 memcpy(fs->icache->buffer, ((char *) &temp_inode) + clen,
 588                        length);
 589
 590                 retval = io_channel_write_blk(fs->io, block_nr, 1,
 591                                               fs->icache->buffer);
 592                 if (retval)
 593                         return retval;
 594         }
 595
 596         fs->flags |= EXT2_FLAG_CHANGED;
 597         return 0;
 598 }
 599
 600 errcode_t ext2fs_get_blocks(ext2_filsys fs, ino_t ino, blk_t *blocks)
 601 {
 602         struct ext2_inode       inode;
 603         int                     i;
 604         errcode_t               retval;
 605
 606         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 607
 608         if (ino > fs->super->s_inodes_count)
 609                 return EXT2_ET_BAD_INODE_NUM;
 610
 611         if (fs->get_blocks) {
 612                 if (!(*fs->get_blocks)(fs, ino, blocks))
 613                         return 0;
 614         }
 615         retval = ext2fs_read_inode(fs, ino, &inode);
 616         if (retval)
 617                 return retval;
 618         for (i=0; i < EXT2_N_BLOCKS; i++)
 619                 blocks[i] = inode.i_block[i];
 620         return 0;
 621 }
 622
 623 errcode_t ext2fs_check_directory(ext2_filsys fs, ino_t ino)
 624 {
 625         struct  ext2_inode      inode;
 626         errcode_t               retval;
 627
 628         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 629
 630         if (ino > fs->super->s_inodes_count)
 631                 return EXT2_ET_BAD_INODE_NUM;
 632
 633         if (fs->check_directory) {
 634                 retval = (fs->check_directory)(fs, ino);
 635                 if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
 636                         return retval;
 637         }
 638         retval = ext2fs_read_inode(fs, ino, &inode);
 639         if (retval)
 640                 return retval;
 641         if (!LINUX_S_ISDIR(inode.i_mode))
 642                 return EXT2_NO_DIRECTORY;
 643         return 0;
 644 }
 645