vcs.maemo.org Git - busybox4maemo/blob - e2fsprogs/old_e2fsprogs/ext2fs/inode.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * inode.c --- utility routines to read and write inodes
   4  *
   5  * Copyright (C) 1993, 1994, 1995, 1996, 1997 Theodore Ts'o.
   6  *
   7  * %Begin-Header%
   8  * This file may be redistributed under the terms of the GNU Public
   9  * License.
  10  * %End-Header%
  11  */
  12
  13 #include <stdio.h>
  14 #include <string.h>
  15 #if HAVE_UNISTD_H
  16 #include <unistd.h>
  17 #endif
  18 #if HAVE_ERRNO_H
  19 #include <errno.h>
  20 #endif
  21 #if HAVE_SYS_STAT_H
  22 #include <sys/stat.h>
  23 #endif
  24 #if HAVE_SYS_TYPES_H
  25 #include <sys/types.h>
  26 #endif
  27
  28 #include "ext2_fs.h"
  29 #include "ext2fsP.h"
  30 #include "e2image.h"
  31
  32 struct ext2_struct_inode_scan {
  33         errcode_t               magic;
  34         ext2_filsys             fs;
  35         ext2_ino_t              current_inode;
  36         blk_t                   current_block;
  37         dgrp_t                  current_group;
  38         ext2_ino_t              inodes_left;
  39         blk_t                   blocks_left;
  40         dgrp_t                  groups_left;
  41         blk_t                   inode_buffer_blocks;
  42         char *                  inode_buffer;
  43         int                     inode_size;
  44         char *                  ptr;
  45         int                     bytes_left;
  46         char                    *temp_buffer;
  47         errcode_t               (*done_group)(ext2_filsys fs,
  48                                               dgrp_t group,
  49                                               void * priv_data);
  50         void *                  done_group_data;
  51         int                     bad_block_ptr;
  52         int                     scan_flags;
  53         int                     reserved[6];
  54 };
  55
  56 /*
  57  * This routine flushes the icache, if it exists.
  58  */
  59 errcode_t ext2fs_flush_icache(ext2_filsys fs)
  60 {
  61         int     i;
  62
  63         if (!fs->icache)
  64                 return 0;
  65
  66         for (i=0; i < fs->icache->cache_size; i++)
  67                 fs->icache->cache[i].ino = 0;
  68
  69         fs->icache->buffer_blk = 0;
  70         return 0;
  71 }
  72
  73 static errcode_t create_icache(ext2_filsys fs)
  74 {
  75         errcode_t       retval;
  76
  77         if (fs->icache)
  78                 return 0;
  79         retval = ext2fs_get_mem(sizeof(struct ext2_inode_cache), &fs->icache);
  80         if (retval)
  81                 return retval;
  82
  83         memset(fs->icache, 0, sizeof(struct ext2_inode_cache));
  84         retval = ext2fs_get_mem(fs->blocksize, &fs->icache->buffer);
  85         if (retval) {
  86                 ext2fs_free_mem(&fs->icache);
  87                 return retval;
  88         }
  89         fs->icache->buffer_blk = 0;
  90         fs->icache->cache_last = -1;
  91         fs->icache->cache_size = 4;
  92         fs->icache->refcount = 1;
  93         retval = ext2fs_get_mem(sizeof(struct ext2_inode_cache_ent)
  94                                 * fs->icache->cache_size,
  95                                 &fs->icache->cache);
  96         if (retval) {
  97                 ext2fs_free_mem(&fs->icache->buffer);
  98                 ext2fs_free_mem(&fs->icache);
  99                 return retval;
 100         }
 101         ext2fs_flush_icache(fs);
 102         return 0;
 103 }
 104
 105 errcode_t ext2fs_open_inode_scan(ext2_filsys fs, int buffer_blocks,
 106                                  ext2_inode_scan *ret_scan)
 107 {
 108         ext2_inode_scan scan;
 109         errcode_t       retval;
 110         errcode_t (*save_get_blocks)(ext2_filsys f, ext2_ino_t ino, blk_t *blocks);
 111
 112         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 113
 114         /*
 115          * If fs->badblocks isn't set, then set it --- since the inode
 116          * scanning functions require it.
 117          */
 118         if (fs->badblocks == 0) {
 119                 /*
 120                  * Temporarly save fs->get_blocks and set it to zero,
 121                  * for compatibility with old e2fsck's.
 122                  */
 123                 save_get_blocks = fs->get_blocks;
 124                 fs->get_blocks = 0;
 125                 retval = ext2fs_read_bb_inode(fs, &fs->badblocks);
 126                 if (retval) {
 127                         ext2fs_badblocks_list_free(fs->badblocks);
 128                         fs->badblocks = 0;
 129                 }
 130                 fs->get_blocks = save_get_blocks;
 131         }
 132
 133         retval = ext2fs_get_mem(sizeof(struct ext2_struct_inode_scan), &scan);
 134         if (retval)
 135                 return retval;
 136         memset(scan, 0, sizeof(struct ext2_struct_inode_scan));
 137
 138         scan->magic = EXT2_ET_MAGIC_INODE_SCAN;
 139         scan->fs = fs;
 140         scan->inode_size = EXT2_INODE_SIZE(fs->super);
 141         scan->bytes_left = 0;
 142         scan->current_group = 0;
 143         scan->groups_left = fs->group_desc_count - 1;
 144         scan->inode_buffer_blocks = buffer_blocks ? buffer_blocks : 8;
 145         scan->current_block = scan->fs->
 146                 group_desc[scan->current_group].bg_inode_table;
 147         scan->inodes_left = EXT2_INODES_PER_GROUP(scan->fs->super);
 148         scan->blocks_left = scan->fs->inode_blocks_per_group;
 149         retval = ext2fs_get_mem((size_t) (scan->inode_buffer_blocks *
 150                                           fs->blocksize),
 151                                 &scan->inode_buffer);
 152         scan->done_group = 0;
 153         scan->done_group_data = 0;
 154         scan->bad_block_ptr = 0;
 155         if (retval) {
 156                 ext2fs_free_mem(&scan);
 157                 return retval;
 158         }
 159         retval = ext2fs_get_mem(scan->inode_size, &scan->temp_buffer);
 160         if (retval) {
 161                 ext2fs_free_mem(&scan->inode_buffer);
 162                 ext2fs_free_mem(&scan);
 163                 return retval;
 164         }
 165         if (scan->fs->badblocks && scan->fs->badblocks->num)
 166                 scan->scan_flags |= EXT2_SF_CHK_BADBLOCKS;
 167         *ret_scan = scan;
 168         return 0;
 169 }
 170
 171 void ext2fs_close_inode_scan(ext2_inode_scan scan)
 172 {
 173         if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
 174                 return;
 175
 176         ext2fs_free_mem(&scan->inode_buffer);
 177         scan->inode_buffer = NULL;
 178         ext2fs_free_mem(&scan->temp_buffer);
 179         scan->temp_buffer = NULL;
 180         ext2fs_free_mem(&scan);
 181 }
 182
 183 void ext2fs_set_inode_callback(ext2_inode_scan scan,
 184                                errcode_t (*done_group)(ext2_filsys fs,
 185                                                        dgrp_t group,
 186                                                        void * priv_data),
 187                                void *done_group_data)
 188 {
 189         if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
 190                 return;
 191
 192         scan->done_group = done_group;
 193         scan->done_group_data = done_group_data;
 194 }
 195
 196 int ext2fs_inode_scan_flags(ext2_inode_scan scan, int set_flags,
 197                             int clear_flags)
 198 {
 199         int     old_flags;
 200
 201         if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
 202                 return 0;
 203
 204         old_flags = scan->scan_flags;
 205         scan->scan_flags &= ~clear_flags;
 206         scan->scan_flags |= set_flags;
 207         return old_flags;
 208 }
 209
 210 /*
 211  * This function is called by ext2fs_get_next_inode when it needs to
 212  * get ready to read in a new blockgroup.
 213  */
 214 static errcode_t get_next_blockgroup(ext2_inode_scan scan)
 215 {
 216         scan->current_group++;
 217         scan->groups_left--;
 218
 219         scan->current_block = scan->fs->
 220                 group_desc[scan->current_group].bg_inode_table;
 221
 222         scan->current_inode = scan->current_group *
 223                 EXT2_INODES_PER_GROUP(scan->fs->super);
 224
 225         scan->bytes_left = 0;
 226         scan->inodes_left = EXT2_INODES_PER_GROUP(scan->fs->super);
 227         scan->blocks_left = scan->fs->inode_blocks_per_group;
 228         return 0;
 229 }
 230
 231 errcode_t ext2fs_inode_scan_goto_blockgroup(ext2_inode_scan scan,
 232                                             int group)
 233 {
 234         scan->current_group = group - 1;
 235         scan->groups_left = scan->fs->group_desc_count - group;
 236         return get_next_blockgroup(scan);
 237 }
 238
 239 /*
 240  * This function is called by get_next_blocks() to check for bad
 241  * blocks in the inode table.
 242  *
 243  * This function assumes that badblocks_list->list is sorted in
 244  * increasing order.
 245  */
 246 static errcode_t check_for_inode_bad_blocks(ext2_inode_scan scan,
 247                                             blk_t *num_blocks)
 248 {
 249         blk_t   blk = scan->current_block;
 250         badblocks_list  bb = scan->fs->badblocks;
 251
 252         /*
 253          * If the inode table is missing, then obviously there are no
 254          * bad blocks.  :-)
 255          */
 256         if (blk == 0)
 257                 return 0;
 258
 259         /*
 260          * If the current block is greater than the bad block listed
 261          * in the bad block list, then advance the pointer until this
 262          * is no longer the case.  If we run out of bad blocks, then
 263          * we don't need to do any more checking!
 264          */
 265         while (blk > bb->list[scan->bad_block_ptr]) {
 266                 if (++scan->bad_block_ptr >= bb->num) {
 267                         scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS;
 268                         return 0;
 269                 }
 270         }
 271
 272         /*
 273          * If the current block is equal to the bad block listed in
 274          * the bad block list, then handle that one block specially.
 275          * (We could try to handle runs of bad blocks, but that
 276          * only increases CPU efficiency by a small amount, at the
 277          * expense of a huge expense of code complexity, and for an
 278          * uncommon case at that.)
 279          */
 280         if (blk == bb->list[scan->bad_block_ptr]) {
 281                 scan->scan_flags |= EXT2_SF_BAD_INODE_BLK;
 282                 *num_blocks = 1;
 283                 if (++scan->bad_block_ptr >= bb->num)
 284                         scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS;
 285                 return 0;
 286         }
 287
 288         /*
 289          * If there is a bad block in the range that we're about to
 290          * read in, adjust the number of blocks to read so that we we
 291          * don't read in the bad block.  (Then the next block to read
 292          * will be the bad block, which is handled in the above case.)
 293          */
 294         if ((blk + *num_blocks) > bb->list[scan->bad_block_ptr])
 295                 *num_blocks = (int) (bb->list[scan->bad_block_ptr] - blk);
 296
 297         return 0;
 298 }
 299
 300 /*
 301  * This function is called by ext2fs_get_next_inode when it needs to
 302  * read in more blocks from the current blockgroup's inode table.
 303  */
 304 static errcode_t get_next_blocks(ext2_inode_scan scan)
 305 {
 306         blk_t           num_blocks;
 307         errcode_t       retval;
 308
 309         /*
 310          * Figure out how many blocks to read; we read at most
 311          * inode_buffer_blocks, and perhaps less if there aren't that
 312          * many blocks left to read.
 313          */
 314         num_blocks = scan->inode_buffer_blocks;
 315         if (num_blocks > scan->blocks_left)
 316                 num_blocks = scan->blocks_left;
 317
 318         /*
 319          * If the past block "read" was a bad block, then mark the
 320          * left-over extra bytes as also being bad.
 321          */
 322         if (scan->scan_flags & EXT2_SF_BAD_INODE_BLK) {
 323                 if (scan->bytes_left)
 324                         scan->scan_flags |= EXT2_SF_BAD_EXTRA_BYTES;
 325                 scan->scan_flags &= ~EXT2_SF_BAD_INODE_BLK;
 326         }
 327
 328         /*
 329          * Do inode bad block processing, if necessary.
 330          */
 331         if (scan->scan_flags & EXT2_SF_CHK_BADBLOCKS) {
 332                 retval = check_for_inode_bad_blocks(scan, &num_blocks);
 333                 if (retval)
 334                         return retval;
 335         }
 336
 337         if ((scan->scan_flags & EXT2_SF_BAD_INODE_BLK) ||
 338             (scan->current_block == 0)) {
 339                 memset(scan->inode_buffer, 0,
 340                        (size_t) num_blocks * scan->fs->blocksize);
 341         } else {
 342                 retval = io_channel_read_blk(scan->fs->io,
 343                                              scan->current_block,
 344                                              (int) num_blocks,
 345                                              scan->inode_buffer);
 346                 if (retval)
 347                         return EXT2_ET_NEXT_INODE_READ;
 348         }
 349         scan->ptr = scan->inode_buffer;
 350         scan->bytes_left = num_blocks * scan->fs->blocksize;
 351
 352         scan->blocks_left -= num_blocks;
 353         if (scan->current_block)
 354                 scan->current_block += num_blocks;
 355         return 0;
 356 }
 357
 358 errcode_t ext2fs_get_next_inode_full(ext2_inode_scan scan, ext2_ino_t *ino,
 359                                      struct ext2_inode *inode, int bufsize)
 360 {
 361         errcode_t       retval;
 362         int             extra_bytes = 0;
 363
 364         EXT2_CHECK_MAGIC(scan, EXT2_ET_MAGIC_INODE_SCAN);
 365
 366         /*
 367          * Do we need to start reading a new block group?
 368          */
 369         if (scan->inodes_left <= 0) {
 370         force_new_group:
 371                 if (scan->done_group) {
 372                         retval = (scan->done_group)
 373                                 (scan->fs, scan->current_group,
 374                                  scan->done_group_data);
 375                         if (retval)
 376                                 return retval;
 377                 }
 378                 if (scan->groups_left <= 0) {
 379                         *ino = 0;
 380                         return 0;
 381                 }
 382                 retval = get_next_blockgroup(scan);
 383                 if (retval)
 384                         return retval;
 385         }
 386         /*
 387          * This is done outside the above if statement so that the
 388          * check can be done for block group #0.
 389          */
 390         if (scan->current_block == 0) {
 391                 if (scan->scan_flags & EXT2_SF_SKIP_MISSING_ITABLE) {
 392                         goto force_new_group;
 393                 } else
 394                         return EXT2_ET_MISSING_INODE_TABLE;
 395         }
 396
 397
 398         /*
 399          * Have we run out of space in the inode buffer?  If so, we
 400          * need to read in more blocks.
 401          */
 402         if (scan->bytes_left < scan->inode_size) {
 403                 memcpy(scan->temp_buffer, scan->ptr, scan->bytes_left);
 404                 extra_bytes = scan->bytes_left;
 405
 406                 retval = get_next_blocks(scan);
 407                 if (retval)
 408                         return retval;
 409 #if 0
 410                 /*
 411                  * XXX test  Need check for used inode somehow.
 412                  * (Note: this is hard.)
 413                  */
 414                 if (is_empty_scan(scan))
 415                         goto force_new_group;
 416 #endif
 417         }
 418
 419         retval = 0;
 420         if (extra_bytes) {
 421                 memcpy(scan->temp_buffer+extra_bytes, scan->ptr,
 422                        scan->inode_size - extra_bytes);
 423                 scan->ptr += scan->inode_size - extra_bytes;
 424                 scan->bytes_left -= scan->inode_size - extra_bytes;
 425
 426 #if BB_BIG_ENDIAN
 427                 if ((scan->fs->flags & EXT2_FLAG_SWAP_BYTES) ||
 428                     (scan->fs->flags & EXT2_FLAG_SWAP_BYTES_READ))
 429                         ext2fs_swap_inode_full(scan->fs,
 430                                 (struct ext2_inode_large *) inode,
 431                                 (struct ext2_inode_large *) scan->temp_buffer,
 432                                 0, bufsize);
 433                 else
 434 #endif
 435                         *inode = *((struct ext2_inode *) scan->temp_buffer);
 436                 if (scan->scan_flags & EXT2_SF_BAD_EXTRA_BYTES)
 437                         retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE;
 438                 scan->scan_flags &= ~EXT2_SF_BAD_EXTRA_BYTES;
 439         } else {
 440 #if BB_BIG_ENDIAN
 441                 if ((scan->fs->flags & EXT2_FLAG_SWAP_BYTES) ||
 442                     (scan->fs->flags & EXT2_FLAG_SWAP_BYTES_READ))
 443                         ext2fs_swap_inode_full(scan->fs,
 444                                 (struct ext2_inode_large *) inode,
 445                                 (struct ext2_inode_large *) scan->ptr,
 446                                 0, bufsize);
 447                 else
 448 #endif
 449                         memcpy(inode, scan->ptr, bufsize);
 450                 scan->ptr += scan->inode_size;
 451                 scan->bytes_left -= scan->inode_size;
 452                 if (scan->scan_flags & EXT2_SF_BAD_INODE_BLK)
 453                         retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE;
 454         }
 455
 456         scan->inodes_left--;
 457         scan->current_inode++;
 458         *ino = scan->current_inode;
 459         return retval;
 460 }
 461
 462 errcode_t ext2fs_get_next_inode(ext2_inode_scan scan, ext2_ino_t *ino,
 463                                 struct ext2_inode *inode)
 464 {
 465         return ext2fs_get_next_inode_full(scan, ino, inode,
 466                                                 sizeof(struct ext2_inode));
 467 }
 468
 469 /*
 470  * Functions to read and write a single inode.
 471  */
 472 errcode_t ext2fs_read_inode_full(ext2_filsys fs, ext2_ino_t ino,
 473                                  struct ext2_inode * inode, int bufsize)
 474 {
 475         unsigned long   group, block, block_nr, offset;
 476         char            *ptr;
 477         errcode_t       retval;
 478         int             clen, i, inodes_per_block, length;
 479         io_channel      io;
 480
 481         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 482
 483         /* Check to see if user has an override function */
 484         if (fs->read_inode) {
 485                 retval = (fs->read_inode)(fs, ino, inode);
 486                 if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
 487                         return retval;
 488         }
 489         /* Create inode cache if not present */
 490         if (!fs->icache) {
 491                 retval = create_icache(fs);
 492                 if (retval)
 493                         return retval;
 494         }
 495         /* Check to see if it's in the inode cache */
 496         if (bufsize == sizeof(struct ext2_inode)) {
 497                 /* only old good inode can be retrieve from the cache */
 498                 for (i=0; i < fs->icache->cache_size; i++) {
 499                         if (fs->icache->cache[i].ino == ino) {
 500                                 *inode = fs->icache->cache[i].inode;
 501                                 return 0;
 502                         }
 503                 }
 504         }
 505         if ((ino == 0) || (ino > fs->super->s_inodes_count))
 506                 return EXT2_ET_BAD_INODE_NUM;
 507         if (fs->flags & EXT2_FLAG_IMAGE_FILE) {
 508                 inodes_per_block = fs->blocksize / EXT2_INODE_SIZE(fs->super);
 509                 block_nr = fs->image_header->offset_inode / fs->blocksize;
 510                 block_nr += (ino - 1) / inodes_per_block;
 511                 offset = ((ino - 1) % inodes_per_block) *
 512                         EXT2_INODE_SIZE(fs->super);
 513                 io = fs->image_io;
 514         } else {
 515                 group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super);
 516                 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) *
 517                         EXT2_INODE_SIZE(fs->super);
 518                 block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super);
 519                 if (!fs->group_desc[(unsigned)group].bg_inode_table)
 520                         return EXT2_ET_MISSING_INODE_TABLE;
 521                 block_nr = fs->group_desc[(unsigned)group].bg_inode_table +
 522                         block;
 523                 io = fs->io;
 524         }
 525         offset &= (EXT2_BLOCK_SIZE(fs->super) - 1);
 526
 527         length = EXT2_INODE_SIZE(fs->super);
 528         if (bufsize < length)
 529                 length = bufsize;
 530
 531         ptr = (char *) inode;
 532         while (length) {
 533                 clen = length;
 534                 if ((offset + length) > fs->blocksize)
 535                         clen = fs->blocksize - offset;
 536
 537                 if (block_nr != fs->icache->buffer_blk) {
 538                         retval = io_channel_read_blk(io, block_nr, 1,
 539                                                      fs->icache->buffer);
 540                         if (retval)
 541                                 return retval;
 542                         fs->icache->buffer_blk = block_nr;
 543                 }
 544
 545                 memcpy(ptr, ((char *) fs->icache->buffer) + (unsigned) offset,
 546                        clen);
 547
 548                 offset = 0;
 549                 length -= clen;
 550                 ptr += clen;
 551                 block_nr++;
 552         }
 553
 554 #if BB_BIG_ENDIAN
 555         if ((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
 556             (fs->flags & EXT2_FLAG_SWAP_BYTES_READ))
 557                 ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) inode,
 558                                        (struct ext2_inode_large *) inode,
 559                                        0, length);
 560 #endif
 561
 562         /* Update the inode cache */
 563         fs->icache->cache_last = (fs->icache->cache_last + 1) %
 564                 fs->icache->cache_size;
 565         fs->icache->cache[fs->icache->cache_last].ino = ino;
 566         fs->icache->cache[fs->icache->cache_last].inode = *inode;
 567
 568         return 0;
 569 }
 570
 571 errcode_t ext2fs_read_inode(ext2_filsys fs, ext2_ino_t ino,
 572                             struct ext2_inode * inode)
 573 {
 574         return ext2fs_read_inode_full(fs, ino, inode,
 575                                         sizeof(struct ext2_inode));
 576 }
 577
 578 errcode_t ext2fs_write_inode_full(ext2_filsys fs, ext2_ino_t ino,
 579                                   struct ext2_inode * inode, int bufsize)
 580 {
 581         unsigned long group, block, block_nr, offset;
 582         errcode_t retval = 0;
 583         struct ext2_inode_large temp_inode, *w_inode;
 584         char *ptr;
 585         int clen, i, length;
 586
 587         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 588
 589         /* Check to see if user provided an override function */
 590         if (fs->write_inode) {
 591                 retval = (fs->write_inode)(fs, ino, inode);
 592                 if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
 593                         return retval;
 594         }
 595
 596         /* Check to see if the inode cache needs to be updated */
 597         if (fs->icache) {
 598                 for (i=0; i < fs->icache->cache_size; i++) {
 599                         if (fs->icache->cache[i].ino == ino) {
 600                                 fs->icache->cache[i].inode = *inode;
 601                                 break;
 602                         }
 603                 }
 604         } else {
 605                 retval = create_icache(fs);
 606                 if (retval)
 607                         return retval;
 608         }
 609
 610         if (!(fs->flags & EXT2_FLAG_RW))
 611                 return EXT2_ET_RO_FILSYS;
 612
 613         if ((ino == 0) || (ino > fs->super->s_inodes_count))
 614                 return EXT2_ET_BAD_INODE_NUM;
 615
 616         length = bufsize;
 617         if (length < EXT2_INODE_SIZE(fs->super))
 618                 length = EXT2_INODE_SIZE(fs->super);
 619
 620         if (length > (int) sizeof(struct ext2_inode_large)) {
 621                 w_inode = xmalloc(length);
 622         } else
 623                 w_inode = &temp_inode;
 624         memset(w_inode, 0, length);
 625
 626 #if BB_BIG_ENDIAN
 627         if ((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
 628             (fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE))
 629                 ext2fs_swap_inode_full(fs, w_inode,
 630                                        (struct ext2_inode_large *) inode,
 631                                        1, bufsize);
 632         else
 633 #endif
 634                 memcpy(w_inode, inode, bufsize);
 635
 636         group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super);
 637         offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) *
 638                 EXT2_INODE_SIZE(fs->super);
 639         block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super);
 640         if (!fs->group_desc[(unsigned) group].bg_inode_table)
 641                 return EXT2_ET_MISSING_INODE_TABLE;
 642         block_nr = fs->group_desc[(unsigned) group].bg_inode_table + block;
 643
 644         offset &= (EXT2_BLOCK_SIZE(fs->super) - 1);
 645
 646         length = EXT2_INODE_SIZE(fs->super);
 647         if (length > bufsize)
 648                 length = bufsize;
 649
 650         ptr = (char *) w_inode;
 651
 652         while (length) {
 653                 clen = length;
 654                 if ((offset + length) > fs->blocksize)
 655                         clen = fs->blocksize - offset;
 656
 657                 if (fs->icache->buffer_blk != block_nr) {
 658                         retval = io_channel_read_blk(fs->io, block_nr, 1,
 659                                                      fs->icache->buffer);
 660                         if (retval)
 661                                 goto errout;
 662                         fs->icache->buffer_blk = block_nr;
 663                 }
 664
 665
 666                 memcpy((char *) fs->icache->buffer + (unsigned) offset,
 667                        ptr, clen);
 668
 669                 retval = io_channel_write_blk(fs->io, block_nr, 1,
 670                                               fs->icache->buffer);
 671                 if (retval)
 672                         goto errout;
 673
 674                 offset = 0;
 675                 ptr += clen;
 676                 length -= clen;
 677                 block_nr++;
 678         }
 679
 680         fs->flags |= EXT2_FLAG_CHANGED;
 681 errout:
 682         if (w_inode && w_inode != &temp_inode)
 683                 free(w_inode);
 684         return retval;
 685 }
 686
 687 errcode_t ext2fs_write_inode(ext2_filsys fs, ext2_ino_t ino,
 688                              struct ext2_inode *inode)
 689 {
 690         return ext2fs_write_inode_full(fs, ino, inode,
 691                                        sizeof(struct ext2_inode));
 692 }
 693
 694 /*
 695  * This function should be called when writing a new inode.  It makes
 696  * sure that extra part of large inodes is initialized properly.
 697  */
 698 errcode_t ext2fs_write_new_inode(ext2_filsys fs, ext2_ino_t ino,
 699                                  struct ext2_inode *inode)
 700 {
 701         struct ext2_inode       *buf;
 702         int                     size = EXT2_INODE_SIZE(fs->super);
 703         struct ext2_inode_large *large_inode;
 704
 705         if (size == sizeof(struct ext2_inode))
 706                 return ext2fs_write_inode_full(fs, ino, inode,
 707                                                sizeof(struct ext2_inode));
 708
 709         buf = xmalloc(size);
 710
 711         memset(buf, 0, size);
 712         *buf = *inode;
 713
 714         large_inode = (struct ext2_inode_large *) buf;
 715         large_inode->i_extra_isize = sizeof(struct ext2_inode_large) -
 716                 EXT2_GOOD_OLD_INODE_SIZE;
 717
 718         return ext2fs_write_inode_full(fs, ino, buf, size);
 719 }
 720
 721
 722 errcode_t ext2fs_get_blocks(ext2_filsys fs, ext2_ino_t ino, blk_t *blocks)
 723 {
 724         struct ext2_inode       inode;
 725         int                     i;
 726         errcode_t               retval;
 727
 728         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 729
 730         if (ino > fs->super->s_inodes_count)
 731                 return EXT2_ET_BAD_INODE_NUM;
 732
 733         if (fs->get_blocks) {
 734                 if (!(*fs->get_blocks)(fs, ino, blocks))
 735                         return 0;
 736         }
 737         retval = ext2fs_read_inode(fs, ino, &inode);
 738         if (retval)
 739                 return retval;
 740         for (i=0; i < EXT2_N_BLOCKS; i++)
 741                 blocks[i] = inode.i_block[i];
 742         return 0;
 743 }
 744
 745 errcode_t ext2fs_check_directory(ext2_filsys fs, ext2_ino_t ino)
 746 {
 747         struct  ext2_inode      inode;
 748         errcode_t               retval;
 749
 750         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 751
 752         if (ino > fs->super->s_inodes_count)
 753                 return EXT2_ET_BAD_INODE_NUM;
 754
 755         if (fs->check_directory) {
 756                 retval = (fs->check_directory)(fs, ino);
 757                 if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
 758                         return retval;
 759         }
 760         retval = ext2fs_read_inode(fs, ino, &inode);
 761         if (retval)
 762                 return retval;
 763         if (!LINUX_S_ISDIR(inode.i_mode))
 764                 return EXT2_ET_NO_DIRECTORY;
 765         return 0;
 766 }
 767