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         return;
 182 }
 183
 184 void ext2fs_set_inode_callback(ext2_inode_scan scan,
 185                                errcode_t (*done_group)(ext2_filsys fs,
 186                                                        dgrp_t group,
 187                                                        void * priv_data),
 188                                void *done_group_data)
 189 {
 190         if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
 191                 return;
 192
 193         scan->done_group = done_group;
 194         scan->done_group_data = done_group_data;
 195 }
 196
 197 int ext2fs_inode_scan_flags(ext2_inode_scan scan, int set_flags,
 198                             int clear_flags)
 199 {
 200         int     old_flags;
 201
 202         if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
 203                 return 0;
 204
 205         old_flags = scan->scan_flags;
 206         scan->scan_flags &= ~clear_flags;
 207         scan->scan_flags |= set_flags;
 208         return old_flags;
 209 }
 210
 211 /*
 212  * This function is called by ext2fs_get_next_inode when it needs to
 213  * get ready to read in a new blockgroup.
 214  */
 215 static errcode_t get_next_blockgroup(ext2_inode_scan scan)
 216 {
 217         scan->current_group++;
 218         scan->groups_left--;
 219
 220         scan->current_block = scan->fs->
 221                 group_desc[scan->current_group].bg_inode_table;
 222
 223         scan->current_inode = scan->current_group *
 224                 EXT2_INODES_PER_GROUP(scan->fs->super);
 225
 226         scan->bytes_left = 0;
 227         scan->inodes_left = EXT2_INODES_PER_GROUP(scan->fs->super);
 228         scan->blocks_left = scan->fs->inode_blocks_per_group;
 229         return 0;
 230 }
 231
 232 errcode_t ext2fs_inode_scan_goto_blockgroup(ext2_inode_scan scan,
 233                                             int group)
 234 {
 235         scan->current_group = group - 1;
 236         scan->groups_left = scan->fs->group_desc_count - group;
 237         return get_next_blockgroup(scan);
 238 }
 239
 240 /*
 241  * This function is called by get_next_blocks() to check for bad
 242  * blocks in the inode table.
 243  *
 244  * This function assumes that badblocks_list->list is sorted in
 245  * increasing order.
 246  */
 247 static errcode_t check_for_inode_bad_blocks(ext2_inode_scan scan,
 248                                             blk_t *num_blocks)
 249 {
 250         blk_t   blk = scan->current_block;
 251         badblocks_list  bb = scan->fs->badblocks;
 252
 253         /*
 254          * If the inode table is missing, then obviously there are no
 255          * bad blocks.  :-)
 256          */
 257         if (blk == 0)
 258                 return 0;
 259
 260         /*
 261          * If the current block is greater than the bad block listed
 262          * in the bad block list, then advance the pointer until this
 263          * is no longer the case.  If we run out of bad blocks, then
 264          * we don't need to do any more checking!
 265          */
 266         while (blk > bb->list[scan->bad_block_ptr]) {
 267                 if (++scan->bad_block_ptr >= bb->num) {
 268                         scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS;
 269                         return 0;
 270                 }
 271         }
 272
 273         /*
 274          * If the current block is equal to the bad block listed in
 275          * the bad block list, then handle that one block specially.
 276          * (We could try to handle runs of bad blocks, but that
 277          * only increases CPU efficiency by a small amount, at the
 278          * expense of a huge expense of code complexity, and for an
 279          * uncommon case at that.)
 280          */
 281         if (blk == bb->list[scan->bad_block_ptr]) {
 282                 scan->scan_flags |= EXT2_SF_BAD_INODE_BLK;
 283                 *num_blocks = 1;
 284                 if (++scan->bad_block_ptr >= bb->num)
 285                         scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS;
 286                 return 0;
 287         }
 288
 289         /*
 290          * If there is a bad block in the range that we're about to
 291          * read in, adjust the number of blocks to read so that we we
 292          * don't read in the bad block.  (Then the next block to read
 293          * will be the bad block, which is handled in the above case.)
 294          */
 295         if ((blk + *num_blocks) > bb->list[scan->bad_block_ptr])
 296                 *num_blocks = (int) (bb->list[scan->bad_block_ptr] - blk);
 297
 298         return 0;
 299 }
 300
 301 /*
 302  * This function is called by ext2fs_get_next_inode when it needs to
 303  * read in more blocks from the current blockgroup's inode table.
 304  */
 305 static errcode_t get_next_blocks(ext2_inode_scan scan)
 306 {
 307         blk_t           num_blocks;
 308         errcode_t       retval;
 309
 310         /*
 311          * Figure out how many blocks to read; we read at most
 312          * inode_buffer_blocks, and perhaps less if there aren't that
 313          * many blocks left to read.
 314          */
 315         num_blocks = scan->inode_buffer_blocks;
 316         if (num_blocks > scan->blocks_left)
 317                 num_blocks = scan->blocks_left;
 318
 319         /*
 320          * If the past block "read" was a bad block, then mark the
 321          * left-over extra bytes as also being bad.
 322          */
 323         if (scan->scan_flags & EXT2_SF_BAD_INODE_BLK) {
 324                 if (scan->bytes_left)
 325                         scan->scan_flags |= EXT2_SF_BAD_EXTRA_BYTES;
 326                 scan->scan_flags &= ~EXT2_SF_BAD_INODE_BLK;
 327         }
 328
 329         /*
 330          * Do inode bad block processing, if necessary.
 331          */
 332         if (scan->scan_flags & EXT2_SF_CHK_BADBLOCKS) {
 333                 retval = check_for_inode_bad_blocks(scan, &num_blocks);
 334                 if (retval)
 335                         return retval;
 336         }
 337
 338         if ((scan->scan_flags & EXT2_SF_BAD_INODE_BLK) ||
 339             (scan->current_block == 0)) {
 340                 memset(scan->inode_buffer, 0,
 341                        (size_t) num_blocks * scan->fs->blocksize);
 342         } else {
 343                 retval = io_channel_read_blk(scan->fs->io,
 344                                              scan->current_block,
 345                                              (int) num_blocks,
 346                                              scan->inode_buffer);
 347                 if (retval)
 348                         return EXT2_ET_NEXT_INODE_READ;
 349         }
 350         scan->ptr = scan->inode_buffer;
 351         scan->bytes_left = num_blocks * scan->fs->blocksize;
 352
 353         scan->blocks_left -= num_blocks;
 354         if (scan->current_block)
 355                 scan->current_block += num_blocks;
 356         return 0;
 357 }
 358
 359 errcode_t ext2fs_get_next_inode_full(ext2_inode_scan scan, ext2_ino_t *ino,
 360                                      struct ext2_inode *inode, int bufsize)
 361 {
 362         errcode_t       retval;
 363         int             extra_bytes = 0;
 364
 365         EXT2_CHECK_MAGIC(scan, EXT2_ET_MAGIC_INODE_SCAN);
 366
 367         /*
 368          * Do we need to start reading a new block group?
 369          */
 370         if (scan->inodes_left <= 0) {
 371         force_new_group:
 372                 if (scan->done_group) {
 373                         retval = (scan->done_group)
 374                                 (scan->fs, scan->current_group,
 375                                  scan->done_group_data);
 376                         if (retval)
 377                                 return retval;
 378                 }
 379                 if (scan->groups_left <= 0) {
 380                         *ino = 0;
 381                         return 0;
 382                 }
 383                 retval = get_next_blockgroup(scan);
 384                 if (retval)
 385                         return retval;
 386         }
 387         /*
 388          * This is done outside the above if statement so that the
 389          * check can be done for block group #0.
 390          */
 391         if (scan->current_block == 0) {
 392                 if (scan->scan_flags & EXT2_SF_SKIP_MISSING_ITABLE) {
 393                         goto force_new_group;
 394                 } else
 395                         return EXT2_ET_MISSING_INODE_TABLE;
 396         }
 397
 398
 399         /*
 400          * Have we run out of space in the inode buffer?  If so, we
 401          * need to read in more blocks.
 402          */
 403         if (scan->bytes_left < scan->inode_size) {
 404                 memcpy(scan->temp_buffer, scan->ptr, scan->bytes_left);
 405                 extra_bytes = scan->bytes_left;
 406
 407                 retval = get_next_blocks(scan);
 408                 if (retval)
 409                         return retval;
 410 #if 0
 411                 /*
 412                  * XXX test  Need check for used inode somehow.
 413                  * (Note: this is hard.)
 414                  */
 415                 if (is_empty_scan(scan))
 416                         goto force_new_group;
 417 #endif
 418         }
 419
 420         retval = 0;
 421         if (extra_bytes) {
 422                 memcpy(scan->temp_buffer+extra_bytes, scan->ptr,
 423                        scan->inode_size - extra_bytes);
 424                 scan->ptr += scan->inode_size - extra_bytes;
 425                 scan->bytes_left -= scan->inode_size - extra_bytes;
 426
 427 #if BB_BIG_ENDIAN
 428                 if ((scan->fs->flags & EXT2_FLAG_SWAP_BYTES) ||
 429                     (scan->fs->flags & EXT2_FLAG_SWAP_BYTES_READ))
 430                         ext2fs_swap_inode_full(scan->fs,
 431                                 (struct ext2_inode_large *) inode,
 432                                 (struct ext2_inode_large *) scan->temp_buffer,
 433                                 0, bufsize);
 434                 else
 435 #endif
 436                         *inode = *((struct ext2_inode *) scan->temp_buffer);
 437                 if (scan->scan_flags & EXT2_SF_BAD_EXTRA_BYTES)
 438                         retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE;
 439                 scan->scan_flags &= ~EXT2_SF_BAD_EXTRA_BYTES;
 440         } else {
 441 #if BB_BIG_ENDIAN
 442                 if ((scan->fs->flags & EXT2_FLAG_SWAP_BYTES) ||
 443                     (scan->fs->flags & EXT2_FLAG_SWAP_BYTES_READ))
 444                         ext2fs_swap_inode_full(scan->fs,
 445                                 (struct ext2_inode_large *) inode,
 446                                 (struct ext2_inode_large *) scan->ptr,
 447                                 0, bufsize);
 448                 else
 449 #endif
 450                         memcpy(inode, scan->ptr, bufsize);
 451                 scan->ptr += scan->inode_size;
 452                 scan->bytes_left -= scan->inode_size;
 453                 if (scan->scan_flags & EXT2_SF_BAD_INODE_BLK)
 454                         retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE;
 455         }
 456
 457         scan->inodes_left--;
 458         scan->current_inode++;
 459         *ino = scan->current_inode;
 460         return retval;
 461 }
 462
 463 errcode_t ext2fs_get_next_inode(ext2_inode_scan scan, ext2_ino_t *ino,
 464                                 struct ext2_inode *inode)
 465 {
 466         return ext2fs_get_next_inode_full(scan, ino, inode,
 467                                                 sizeof(struct ext2_inode));
 468 }
 469
 470 /*
 471  * Functions to read and write a single inode.
 472  */
 473 errcode_t ext2fs_read_inode_full(ext2_filsys fs, ext2_ino_t ino,
 474                                  struct ext2_inode * inode, int bufsize)
 475 {
 476         unsigned long   group, block, block_nr, offset;
 477         char            *ptr;
 478         errcode_t       retval;
 479         int             clen, i, inodes_per_block, length;
 480         io_channel      io;
 481
 482         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 483
 484         /* Check to see if user has an override function */
 485         if (fs->read_inode) {
 486                 retval = (fs->read_inode)(fs, ino, inode);
 487                 if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
 488                         return retval;
 489         }
 490         /* Create inode cache if not present */
 491         if (!fs->icache) {
 492                 retval = create_icache(fs);
 493                 if (retval)
 494                         return retval;
 495         }
 496         /* Check to see if it's in the inode cache */
 497         if (bufsize == sizeof(struct ext2_inode)) {
 498                 /* only old good inode can be retrieve from the cache */
 499                 for (i=0; i < fs->icache->cache_size; i++) {
 500                         if (fs->icache->cache[i].ino == ino) {
 501                                 *inode = fs->icache->cache[i].inode;
 502                                 return 0;
 503                         }
 504                 }
 505         }
 506         if ((ino == 0) || (ino > fs->super->s_inodes_count))
 507                 return EXT2_ET_BAD_INODE_NUM;
 508         if (fs->flags & EXT2_FLAG_IMAGE_FILE) {
 509                 inodes_per_block = fs->blocksize / EXT2_INODE_SIZE(fs->super);
 510                 block_nr = fs->image_header->offset_inode / fs->blocksize;
 511                 block_nr += (ino - 1) / inodes_per_block;
 512                 offset = ((ino - 1) % inodes_per_block) *
 513                         EXT2_INODE_SIZE(fs->super);
 514                 io = fs->image_io;
 515         } else {
 516                 group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super);
 517                 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) *
 518                         EXT2_INODE_SIZE(fs->super);
 519                 block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super);
 520                 if (!fs->group_desc[(unsigned)group].bg_inode_table)
 521                         return EXT2_ET_MISSING_INODE_TABLE;
 522                 block_nr = fs->group_desc[(unsigned)group].bg_inode_table +
 523                         block;
 524                 io = fs->io;
 525         }
 526         offset &= (EXT2_BLOCK_SIZE(fs->super) - 1);
 527
 528         length = EXT2_INODE_SIZE(fs->super);
 529         if (bufsize < length)
 530                 length = bufsize;
 531
 532         ptr = (char *) inode;
 533         while (length) {
 534                 clen = length;
 535                 if ((offset + length) > fs->blocksize)
 536                         clen = fs->blocksize - offset;
 537
 538                 if (block_nr != fs->icache->buffer_blk) {
 539                         retval = io_channel_read_blk(io, block_nr, 1,
 540                                                      fs->icache->buffer);
 541                         if (retval)
 542                                 return retval;
 543                         fs->icache->buffer_blk = block_nr;
 544                 }
 545
 546                 memcpy(ptr, ((char *) fs->icache->buffer) + (unsigned) offset,
 547                        clen);
 548
 549                 offset = 0;
 550                 length -= clen;
 551                 ptr += clen;
 552                 block_nr++;
 553         }
 554
 555 #if BB_BIG_ENDIAN
 556         if ((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
 557             (fs->flags & EXT2_FLAG_SWAP_BYTES_READ))
 558                 ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) inode,
 559                                        (struct ext2_inode_large *) inode,
 560                                        0, length);
 561 #endif
 562
 563         /* Update the inode cache */
 564         fs->icache->cache_last = (fs->icache->cache_last + 1) %
 565                 fs->icache->cache_size;
 566         fs->icache->cache[fs->icache->cache_last].ino = ino;
 567         fs->icache->cache[fs->icache->cache_last].inode = *inode;
 568
 569         return 0;
 570 }
 571
 572 errcode_t ext2fs_read_inode(ext2_filsys fs, ext2_ino_t ino,
 573                             struct ext2_inode * inode)
 574 {
 575         return ext2fs_read_inode_full(fs, ino, inode,
 576                                         sizeof(struct ext2_inode));
 577 }
 578
 579 errcode_t ext2fs_write_inode_full(ext2_filsys fs, ext2_ino_t ino,
 580                                   struct ext2_inode * inode, int bufsize)
 581 {
 582         unsigned long group, block, block_nr, offset;
 583         errcode_t retval = 0;
 584         struct ext2_inode_large temp_inode, *w_inode;
 585         char *ptr;
 586         int clen, i, length;
 587
 588         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 589
 590         /* Check to see if user provided an override function */
 591         if (fs->write_inode) {
 592                 retval = (fs->write_inode)(fs, ino, inode);
 593                 if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
 594                         return retval;
 595         }
 596
 597         /* Check to see if the inode cache needs to be updated */
 598         if (fs->icache) {
 599                 for (i=0; i < fs->icache->cache_size; i++) {
 600                         if (fs->icache->cache[i].ino == ino) {
 601                                 fs->icache->cache[i].inode = *inode;
 602                                 break;
 603                         }
 604                 }
 605         } else {
 606                 retval = create_icache(fs);
 607                 if (retval)
 608                         return retval;
 609         }
 610
 611         if (!(fs->flags & EXT2_FLAG_RW))
 612                 return EXT2_ET_RO_FILSYS;
 613
 614         if ((ino == 0) || (ino > fs->super->s_inodes_count))
 615                 return EXT2_ET_BAD_INODE_NUM;
 616
 617         length = bufsize;
 618         if (length < EXT2_INODE_SIZE(fs->super))
 619                 length = EXT2_INODE_SIZE(fs->super);
 620
 621         if (length > (int) sizeof(struct ext2_inode_large)) {
 622                 w_inode = xmalloc(length);
 623         } else
 624                 w_inode = &temp_inode;
 625         memset(w_inode, 0, length);
 626
 627 #if BB_BIG_ENDIAN
 628         if ((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
 629             (fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE))
 630                 ext2fs_swap_inode_full(fs, w_inode,
 631                                        (struct ext2_inode_large *) inode,
 632                                        1, bufsize);
 633         else
 634 #endif
 635                 memcpy(w_inode, inode, bufsize);
 636
 637         group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super);
 638         offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) *
 639                 EXT2_INODE_SIZE(fs->super);
 640         block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super);
 641         if (!fs->group_desc[(unsigned) group].bg_inode_table)
 642                 return EXT2_ET_MISSING_INODE_TABLE;
 643         block_nr = fs->group_desc[(unsigned) group].bg_inode_table + block;
 644
 645         offset &= (EXT2_BLOCK_SIZE(fs->super) - 1);
 646
 647         length = EXT2_INODE_SIZE(fs->super);
 648         if (length > bufsize)
 649                 length = bufsize;
 650
 651         ptr = (char *) w_inode;
 652
 653         while (length) {
 654                 clen = length;
 655                 if ((offset + length) > fs->blocksize)
 656                         clen = fs->blocksize - offset;
 657
 658                 if (fs->icache->buffer_blk != block_nr) {
 659                         retval = io_channel_read_blk(fs->io, block_nr, 1,
 660                                                      fs->icache->buffer);
 661                         if (retval)
 662                                 goto errout;
 663                         fs->icache->buffer_blk = block_nr;
 664                 }
 665
 666
 667                 memcpy((char *) fs->icache->buffer + (unsigned) offset,
 668                        ptr, clen);
 669
 670                 retval = io_channel_write_blk(fs->io, block_nr, 1,
 671                                               fs->icache->buffer);
 672                 if (retval)
 673                         goto errout;
 674
 675                 offset = 0;
 676                 ptr += clen;
 677                 length -= clen;
 678                 block_nr++;
 679         }
 680
 681         fs->flags |= EXT2_FLAG_CHANGED;
 682 errout:
 683         if (w_inode && w_inode != &temp_inode)
 684                 free(w_inode);
 685         return retval;
 686 }
 687
 688 errcode_t ext2fs_write_inode(ext2_filsys fs, ext2_ino_t ino,
 689                              struct ext2_inode *inode)
 690 {
 691         return ext2fs_write_inode_full(fs, ino, inode,
 692                                        sizeof(struct ext2_inode));
 693 }
 694
 695 /*
 696  * This function should be called when writing a new inode.  It makes
 697  * sure that extra part of large inodes is initialized properly.
 698  */
 699 errcode_t ext2fs_write_new_inode(ext2_filsys fs, ext2_ino_t ino,
 700                                  struct ext2_inode *inode)
 701 {
 702         struct ext2_inode       *buf;
 703         int                     size = EXT2_INODE_SIZE(fs->super);
 704         struct ext2_inode_large *large_inode;
 705
 706         if (size == sizeof(struct ext2_inode))
 707                 return ext2fs_write_inode_full(fs, ino, inode,
 708                                                sizeof(struct ext2_inode));
 709
 710         buf = xmalloc(size);
 711
 712         memset(buf, 0, size);
 713         *buf = *inode;
 714
 715         large_inode = (struct ext2_inode_large *) buf;
 716         large_inode->i_extra_isize = sizeof(struct ext2_inode_large) -
 717                 EXT2_GOOD_OLD_INODE_SIZE;
 718
 719         return ext2fs_write_inode_full(fs, ino, buf, size);
 720 }
 721
 722
 723 errcode_t ext2fs_get_blocks(ext2_filsys fs, ext2_ino_t ino, blk_t *blocks)
 724 {
 725         struct ext2_inode       inode;
 726         int                     i;
 727         errcode_t               retval;
 728
 729         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 730
 731         if (ino > fs->super->s_inodes_count)
 732                 return EXT2_ET_BAD_INODE_NUM;
 733
 734         if (fs->get_blocks) {
 735                 if (!(*fs->get_blocks)(fs, ino, blocks))
 736                         return 0;
 737         }
 738         retval = ext2fs_read_inode(fs, ino, &inode);
 739         if (retval)
 740                 return retval;
 741         for (i=0; i < EXT2_N_BLOCKS; i++)
 742                 blocks[i] = inode.i_block[i];
 743         return 0;
 744 }
 745
 746 errcode_t ext2fs_check_directory(ext2_filsys fs, ext2_ino_t ino)
 747 {
 748         struct  ext2_inode      inode;
 749         errcode_t               retval;
 750
 751         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 752
 753         if (ino > fs->super->s_inodes_count)
 754                 return EXT2_ET_BAD_INODE_NUM;
 755
 756         if (fs->check_directory) {
 757                 retval = (fs->check_directory)(fs, ino);
 758                 if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
 759                         return retval;
 760         }
 761         retval = ext2fs_read_inode(fs, ino, &inode);
 762         if (retval)
 763                 return retval;
 764         if (!LINUX_S_ISDIR(inode.i_mode))
 765                 return EXT2_ET_NO_DIRECTORY;
 766         return 0;
 767 }
 768