resize/resize2fs.c

   1 /*
   2  * resize2fs.c --- ext2 main routine
   3  *
   4  * Copyright (C) 1997 Theodore Ts'o
   5  *
   6  * %Begin-Header%
   7  * All rights reserved.
   8  * %End-Header%
   9  */
  10
  11 /*
  12  * Resizing a filesystem consists of the following phases:
  13  *
  14  *      1.  Adjust superblock and write out new parts of the inode
  15  *              table
  16  *      2.  Determine blocks which need to be relocated, and copy the
  17  *              contents of blocks from their old locations to the new ones.
  18  *      3.  Scan the inode table, doing the following:
  19  *              a.  If blocks have been moved, update the block
  20  *                      pointers in the inodes and indirect blocks to
  21  *                      point at the new block locations.
  22  *              b.  If parts of the inode table need to be evacuated,
  23  *                      copy inodes from their old locations to their
  24  *                      new ones.
  25  *              c.  If (b) needs to be done, note which blocks contain
  26  *                      directory information, since we will need to
  27  *                      update the directory information.
  28  *      4.  Update the directory blocks with the new inode locations.
  29  *      5.  Move the inode tables, if necessary.
  30  */
  31
  32 #include "resize2fs.h"
  33
  34 #ifdef linux                    /* Kludge for debugging */
  35 #define RESIZE2FS_DEBUG
  36 #endif
  37
  38 static errcode_t adjust_superblock(ext2_resize_t rfs, blk_t new_size);
  39 static errcode_t blocks_to_move(ext2_resize_t rfs);
  40 static errcode_t block_mover(ext2_resize_t rfs);
  41 static errcode_t inode_scan_and_fix(ext2_resize_t rfs);
  42 static errcode_t inode_ref_fix(ext2_resize_t rfs);
  43 static errcode_t move_itables(ext2_resize_t rfs);
  44 static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs);
  45
  46 /*
  47  * Some helper CPP macros
  48  */
  49 #define FS_BLOCK_BM(fs, i) ((fs)->group_desc[(i)].bg_block_bitmap)
  50 #define FS_INODE_BM(fs, i) ((fs)->group_desc[(i)].bg_inode_bitmap)
  51 #define FS_INODE_TB(fs, i) ((fs)->group_desc[(i)].bg_inode_table)
  52
  53 #define IS_BLOCK_BM(fs, i, blk) ((blk) == FS_BLOCK_BM((fs),(i)))
  54 #define IS_INODE_BM(fs, i, blk) ((blk) == FS_INODE_BM((fs),(i)))
  55
  56 #define IS_INODE_TB(fs, i, blk) (((blk) >= FS_INODE_TB((fs), (i))) && \
  57                                  ((blk) < (FS_INODE_TB((fs), (i)) + \
  58                                            (fs)->inode_blocks_per_group)))
  59
  60
  61
  62 /*
  63  * This is the top-level routine which does the dirty deed....
  64  */
  65 errcode_t resize_fs(ext2_filsys fs, blk_t new_size, int flags,
  66                     errcode_t (*progress)(ext2_resize_t rfs, int pass,
  67                                      unsigned long cur,
  68                                      unsigned long max))
  69 {
  70         ext2_resize_t   rfs;
  71         errcode_t       retval;
  72
  73         retval = ext2fs_read_bitmaps(fs);
  74         if (retval)
  75                 return retval;
  76
  77         /*
  78          * Create the data structure
  79          */
  80         retval = ext2fs_get_mem(sizeof(struct ext2_resize_struct),
  81                                 (void **) &rfs);
  82         if (retval)
  83                 return retval;
  84         memset(rfs, 0, sizeof(struct ext2_resize_struct));
  85
  86         rfs->old_fs = fs;
  87         rfs->flags = flags;
  88         rfs->itable_buf  = 0;
  89         rfs->progress = progress;
  90         retval = ext2fs_dup_handle(fs, &rfs->new_fs);
  91         if (retval)
  92                 goto errout;
  93
  94         retval = adjust_superblock(rfs, new_size);
  95         if (retval)
  96                 goto errout;
  97
  98         retval = blocks_to_move(rfs);
  99         if (retval)
 100                 goto errout;
 101
 102 #ifdef RESIZE2FS_DEBUG
 103         if (rfs->flags & RESIZE_DEBUG_BMOVE)
 104                 printf("Number of free blocks: %d/%d, Needed: %d\n",
 105                        rfs->old_fs->super->s_free_blocks_count,
 106                        rfs->new_fs->super->s_free_blocks_count,
 107                        rfs->needed_blocks);
 108 #endif
 109
 110         retval = block_mover(rfs);
 111         if (retval)
 112                 goto errout;
 113
 114         retval = inode_scan_and_fix(rfs);
 115         if (retval)
 116                 goto errout;
 117
 118         retval = inode_ref_fix(rfs);
 119         if (retval)
 120                 goto errout;
 121
 122         retval = ext2fs_calculate_summary_stats(rfs->new_fs);
 123         if (retval)
 124                 goto errout;
 125
 126         retval = move_itables(rfs);
 127         if (retval)
 128                 goto errout;
 129
 130         retval = ext2fs_close(rfs->new_fs);
 131         if (retval)
 132                 goto errout;
 133
 134         rfs->flags = flags;
 135
 136         ext2fs_free(rfs->old_fs);
 137         if (rfs->itable_buf)
 138                 ext2fs_free_mem((void **) &rfs->itable_buf);
 139         ext2fs_free_mem((void **) &rfs);
 140
 141         return 0;
 142
 143 errout:
 144         if (rfs->new_fs)
 145                 ext2fs_free(rfs->new_fs);
 146         if (rfs->itable_buf)
 147                 ext2fs_free_mem((void **) &rfs->itable_buf);
 148         ext2fs_free_mem((void **) &rfs);
 149         return retval;
 150 }
 151
 152 /* --------------------------------------------------------------------
 153  *
 154  * Resize processing, phase 1.
 155  *
 156  * In this phase we adjust the in-memory superblock information, and
 157  * initialize any new parts of the inode table.  The new parts of the
 158  * inode table are created in virgin disk space, so we can abort here
 159  * without any side effects.
 160  * --------------------------------------------------------------------
 161  */
 162
 163 /*
 164  * This routine adjusts the superblock and other data structures...
 165  */
 166 static errcode_t adjust_superblock(ext2_resize_t rfs, blk_t new_size)
 167 {
 168         ext2_filsys fs;
 169         int             overhead = 0;
 170         int             rem, adj = 0;
 171         errcode_t       retval;
 172         ino_t           real_end;
 173         blk_t           blk, group_block;
 174         unsigned long   i, j;
 175         int             old_numblocks, numblocks, adjblocks;
 176         unsigned long   max_group;
 177
 178         fs = rfs->new_fs;
 179         fs->super->s_blocks_count = new_size;
 180         ext2fs_mark_super_dirty(fs);
 181         ext2fs_mark_bb_dirty(fs);
 182         ext2fs_mark_ib_dirty(fs);
 183
 184 retry:
 185         fs->group_desc_count = (fs->super->s_blocks_count -
 186                                 fs->super->s_first_data_block +
 187                                 EXT2_BLOCKS_PER_GROUP(fs->super) - 1)
 188                 / EXT2_BLOCKS_PER_GROUP(fs->super);
 189         if (fs->group_desc_count == 0)
 190                 return EXT2_ET_TOOSMALL;
 191         fs->desc_blocks = (fs->group_desc_count +
 192                            EXT2_DESC_PER_BLOCK(fs->super) - 1)
 193                 / EXT2_DESC_PER_BLOCK(fs->super);
 194
 195         /*
 196          * Overhead is the number of bookkeeping blocks per group.  It
 197          * includes the superblock backup, the group descriptor
 198          * backups, the inode bitmap, the block bitmap, and the inode
 199          * table.
 200          *
 201          * XXX Not all block groups need the descriptor blocks, but
 202          * being clever is tricky...
 203          */
 204         overhead = 3 + fs->desc_blocks + fs->inode_blocks_per_group;
 205
 206         /*
 207          * See if the last group is big enough to support the
 208          * necessary data structures.  If not, we need to get rid of
 209          * it.
 210          */
 211         rem = (fs->super->s_blocks_count - fs->super->s_first_data_block) %
 212                 fs->super->s_blocks_per_group;
 213         if ((fs->group_desc_count == 1) && rem && (rem < overhead))
 214                 return EXT2_ET_TOOSMALL;
 215         if (rem && (rem < overhead+50)) {
 216                 fs->super->s_blocks_count -= rem;
 217                 goto retry;
 218         }
 219         /*
 220          * Adjust the number of inodes
 221          */
 222         fs->super->s_inodes_count = fs->super->s_inodes_per_group *
 223                 fs->group_desc_count;
 224
 225         /*
 226          * Adjust the number of free blocks
 227          */
 228         blk = rfs->old_fs->super->s_blocks_count;
 229         if (blk > fs->super->s_blocks_count)
 230                 fs->super->s_free_blocks_count -=
 231                         (blk - fs->super->s_blocks_count);
 232         else
 233                 fs->super->s_free_blocks_count +=
 234                         (fs->super->s_blocks_count - blk);
 235
 236         /*
 237          * Adjust the number of reserved blocks
 238          */
 239         blk = rfs->old_fs->super->s_r_blocks_count * 100 /
 240                 rfs->old_fs->super->s_blocks_count;
 241         fs->super->s_r_blocks_count = ((fs->super->s_blocks_count * blk)
 242                                        / 100);
 243
 244         /*
 245          * Adjust the bitmaps for size
 246          */
 247         retval = ext2fs_resize_inode_bitmap(fs->super->s_inodes_count,
 248                                             fs->super->s_inodes_count,
 249                                             fs->inode_map);
 250         if (retval) goto errout;
 251
 252         real_end = ((EXT2_BLOCKS_PER_GROUP(fs->super)
 253                      * fs->group_desc_count)) - 1 +
 254                              fs->super->s_first_data_block;
 255         retval = ext2fs_resize_block_bitmap(fs->super->s_blocks_count-1,
 256                                             real_end, fs->block_map);
 257
 258         if (retval) goto errout;
 259
 260         /*
 261          * Reallocate the group descriptors as necessary.
 262          */
 263         if (rfs->old_fs->desc_blocks != fs->desc_blocks) {
 264                 retval = ext2fs_resize_mem(fs->desc_blocks * fs->blocksize,
 265                                            (void **) &fs->group_desc);
 266                 if (retval)
 267                         goto errout;
 268         }
 269
 270         /*
 271          * Check to make sure there are enough inodes
 272          */
 273         if ((rfs->old_fs->super->s_inodes_count -
 274              rfs->old_fs->super->s_free_inodes_count) >
 275             rfs->new_fs->super->s_inodes_count) {
 276                 retval = ENOSPC;
 277                 goto errout;
 278         }
 279
 280         /*
 281          * If we are shrinking the number block groups, we're done and
 282          * can exit now.
 283          */
 284         if (rfs->old_fs->group_desc_count > fs->group_desc_count) {
 285                 retval = 0;
 286                 goto errout;
 287         }
 288         /*
 289          * Fix the count of the last (old) block group
 290          */
 291         old_numblocks = (rfs->old_fs->super->s_blocks_count -
 292                          rfs->old_fs->super->s_first_data_block) %
 293                                  rfs->old_fs->super->s_blocks_per_group;
 294         if (!old_numblocks)
 295                 old_numblocks = rfs->old_fs->super->s_blocks_per_group;
 296         if (rfs->old_fs->group_desc_count == fs->group_desc_count) {
 297                 numblocks = (rfs->new_fs->super->s_blocks_count -
 298                              rfs->new_fs->super->s_first_data_block) %
 299                                      rfs->new_fs->super->s_blocks_per_group;
 300                 if (!numblocks)
 301                         numblocks = rfs->new_fs->super->s_blocks_per_group;
 302         } else
 303                 numblocks = rfs->new_fs->super->s_blocks_per_group;
 304         i = rfs->old_fs->group_desc_count - 1;
 305         fs->group_desc[i].bg_free_blocks_count += (numblocks-old_numblocks);
 306
 307         /*
 308          * If the number of block groups is staying the same, we're
 309          * done and can exit now.  (If the number block groups is
 310          * shrinking, we had exited earlier.)
 311          */
 312         if (rfs->old_fs->group_desc_count >= fs->group_desc_count) {
 313                 retval = 0;
 314                 goto errout;
 315         }
 316         /*
 317          * Initialize the new block group descriptors
 318          */
 319         retval = ext2fs_get_mem(fs->blocksize * fs->inode_blocks_per_group,
 320                                 (void **) &rfs->itable_buf);
 321         if (retval)
 322                 goto errout;
 323
 324         memset(rfs->itable_buf, 0, fs->blocksize * fs->inode_blocks_per_group);
 325         group_block = fs->super->s_first_data_block +
 326                 rfs->old_fs->group_desc_count * fs->super->s_blocks_per_group;
 327
 328         adj = rfs->old_fs->group_desc_count;
 329         max_group = fs->group_desc_count - adj;
 330         if (rfs->progress) {
 331                 retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
 332                                        0, max_group);
 333                 if (retval)
 334                         goto errout;
 335         }
 336         for (i = rfs->old_fs->group_desc_count;
 337              i < fs->group_desc_count; i++) {
 338                 memset(&fs->group_desc[i], 0,
 339                        sizeof(struct ext2_group_desc));
 340                 adjblocks = 0;
 341
 342                 if (i == fs->group_desc_count-1) {
 343                         numblocks = (fs->super->s_blocks_count -
 344                                      fs->super->s_first_data_block) %
 345                                              fs->super->s_blocks_per_group;
 346                         if (!numblocks)
 347                                 numblocks = fs->super->s_blocks_per_group;
 348                 } else
 349                         numblocks = fs->super->s_blocks_per_group;
 350
 351                 if (ext2fs_bg_has_super(fs, i)) {
 352                         for (j=0; j < fs->desc_blocks+1; j++)
 353                                 ext2fs_mark_block_bitmap(fs->block_map,
 354                                                          group_block + j);
 355                         adjblocks = 1 + fs->desc_blocks;
 356                 }
 357                 adjblocks += 2 + fs->inode_blocks_per_group;
 358
 359                 numblocks -= adjblocks;
 360                 fs->super->s_free_blocks_count -= adjblocks;
 361                 fs->super->s_free_inodes_count +=
 362                         fs->super->s_inodes_per_group;
 363                 fs->group_desc[i].bg_free_blocks_count = numblocks;
 364                 fs->group_desc[i].bg_free_inodes_count =
 365                         fs->super->s_inodes_per_group;
 366                 fs->group_desc[i].bg_used_dirs_count = 0;
 367
 368                 retval = ext2fs_allocate_group_table(fs, i, 0);
 369                 if (retval) goto errout;
 370
 371                 /*
 372                  * Write out the new inode table
 373                  */
 374                 retval = io_channel_write_blk(fs->io,
 375                                               fs->group_desc[i].bg_inode_table,
 376                                               fs->inode_blocks_per_group,
 377                                               rfs->itable_buf);
 378                 if (retval) goto errout;
 379
 380                 io_channel_flush(fs->io);
 381                 if (rfs->progress) {
 382                         retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
 383                                                i - adj + 1, max_group);
 384                         if (retval)
 385                                 goto errout;
 386                 }
 387                 group_block += fs->super->s_blocks_per_group;
 388         }
 389         io_channel_flush(fs->io);
 390         retval = 0;
 391
 392 errout:
 393         return retval;
 394 }
 395
 396 /* --------------------------------------------------------------------
 397  *
 398  * Resize processing, phase 2.
 399  *
 400  * In this phase we adjust determine which blocks need to be moved, in
 401  * blocks_to_move().  We then copy the blocks to their ultimate new
 402  * destinations using block_mover().  Since we are copying blocks to
 403  * their new locations, again during this pass we can abort without
 404  * any problems.
 405  * --------------------------------------------------------------------
 406  */
 407
 408 /*
 409  * This helper function creates a block bitmap with all of the
 410  * filesystem meta-data blocks.
 411  */
 412 static errcode_t mark_table_blocks(ext2_filsys fs,
 413                                    ext2fs_block_bitmap *ret_bmap)
 414 {
 415         blk_t                   block, b;
 416         int                     i,j;
 417         ext2fs_block_bitmap     bmap;
 418         errcode_t               retval;
 419
 420         retval = ext2fs_allocate_block_bitmap(fs, "meta-data blocks", &bmap);
 421         if (retval)
 422                 return retval;
 423
 424         block = fs->super->s_first_data_block;
 425         for (i = 0; i < fs->group_desc_count; i++) {
 426                 if (ext2fs_bg_has_super(fs, i)) {
 427                         /*
 428                          * Mark this group's copy of the superblock
 429                          */
 430                         ext2fs_mark_block_bitmap(bmap, block);
 431
 432                         /*
 433                          * Mark this group's copy of the descriptors
 434                          */
 435                         for (j = 0; j < fs->desc_blocks; j++)
 436                                 ext2fs_mark_block_bitmap(bmap, block + j + 1);
 437                 }
 438
 439                 /*
 440                  * Mark the blocks used for the inode table
 441                  */
 442                 for (j = 0, b = fs->group_desc[i].bg_inode_table;
 443                      j < fs->inode_blocks_per_group;
 444                      j++, b++)
 445                         ext2fs_mark_block_bitmap(bmap, b);
 446
 447                 /*
 448                  * Mark block used for the block bitmap
 449                  */
 450                 ext2fs_mark_block_bitmap(bmap,
 451                                          fs->group_desc[i].bg_block_bitmap);
 452                 /*
 453                  * Mark block used for the inode bitmap
 454                  */
 455                 ext2fs_mark_block_bitmap(bmap,
 456                                          fs->group_desc[i].bg_inode_bitmap);
 457                 block += fs->super->s_blocks_per_group;
 458         }
 459         *ret_bmap = bmap;
 460         return 0;
 461 }
 462
 463 /*
 464  * This routine marks and unmarks reserved blocks in the new block
 465  * bitmap.  It also determines which blocks need to be moved and
 466  * places this information into the move_blocks bitmap.
 467  */
 468 static errcode_t blocks_to_move(ext2_resize_t rfs)
 469 {
 470         int     i, j, max;
 471         blk_t   blk, group_blk;
 472         unsigned long old_blocks, new_blocks;
 473         errcode_t       retval;
 474         ext2_filsys     fs, old_fs;
 475         ext2fs_block_bitmap     meta_bmap;
 476
 477         fs = rfs->new_fs;
 478         old_fs = rfs->old_fs;
 479         if (old_fs->super->s_blocks_count > fs->super->s_blocks_count)
 480                 fs = rfs->old_fs;
 481
 482         retval = ext2fs_allocate_block_bitmap(fs, "reserved blocks",
 483                                               &rfs->reserve_blocks);
 484         if (retval)
 485                 return retval;
 486
 487         retval = ext2fs_allocate_block_bitmap(fs, "blocks to be moved",
 488                                               &rfs->move_blocks);
 489         if (retval)
 490                 return retval;
 491
 492         retval = mark_table_blocks(old_fs, &meta_bmap);
 493         if (retval)
 494                 return retval;
 495
 496         fs = rfs->new_fs;
 497
 498         /*
 499          * If we're shrinking the filesystem, we need to move all of
 500          * the blocks that don't fit any more
 501          */
 502         for (blk = fs->super->s_blocks_count;
 503              blk < old_fs->super->s_blocks_count; blk++) {
 504                 if (ext2fs_test_block_bitmap(old_fs->block_map, blk) &&
 505                     !ext2fs_test_block_bitmap(meta_bmap, blk)) {
 506                         ext2fs_mark_block_bitmap(rfs->move_blocks, blk);
 507                         rfs->needed_blocks++;
 508                 }
 509                 ext2fs_mark_block_bitmap(rfs->reserve_blocks, blk);
 510         }
 511
 512         old_blocks = old_fs->desc_blocks;
 513         new_blocks = fs->desc_blocks;
 514
 515         if (old_blocks == new_blocks) {
 516                 retval = 0;
 517                 goto errout;
 518         }
 519
 520         max = fs->group_desc_count;
 521         if (max > old_fs->group_desc_count)
 522                 max = old_fs->group_desc_count;
 523         group_blk = old_fs->super->s_first_data_block;
 524         /*
 525          * If we're reducing the number of descriptor blocks, this
 526          * makes life easy.  :-)   We just have to mark some extra
 527          * blocks as free.
 528          */
 529         if (old_blocks > new_blocks) {
 530                 for (i = 0; i < max; i++) {
 531                         if (!ext2fs_bg_has_super(fs, i)) {
 532                                 group_blk += fs->super->s_blocks_per_group;
 533                                 continue;
 534                         }
 535                         for (blk = group_blk+1+new_blocks;
 536                              blk < group_blk+1+old_blocks; blk++) {
 537                                 ext2fs_unmark_block_bitmap(fs->block_map,
 538                                                            blk);
 539                                 rfs->needed_blocks--;
 540                         }
 541                         group_blk += fs->super->s_blocks_per_group;
 542                 }
 543                 retval = 0;
 544                 goto errout;
 545         }
 546         /*
 547          * If we're increasing the number of descriptor blocks, life
 548          * gets interesting....
 549          */
 550         for (i = 0; i < max; i++) {
 551                 if (!ext2fs_bg_has_super(fs, i))
 552                         goto next_group;
 553
 554                 for (blk = group_blk;
 555                      blk < group_blk + 1 + new_blocks; blk++) {
 556                         ext2fs_mark_block_bitmap(rfs->reserve_blocks, blk);
 557                         ext2fs_mark_block_bitmap(fs->block_map, blk);
 558
 559                         /*
 560                          * Check to see if we overlap with the inode
 561                          * or block bitmap, or the inode tables.  If
 562                          * not, and the block is in use, then mark it
 563                          * as a block to be moved.
 564                          */
 565                         if (IS_BLOCK_BM(fs, i, blk)) {
 566                                 FS_BLOCK_BM(fs, i) = 0;
 567                                 rfs->needed_blocks++;
 568                         } else if (IS_INODE_BM(fs, i, blk)) {
 569                                 FS_INODE_BM(fs, i) = 0;
 570                                 rfs->needed_blocks++;
 571                         } else if (IS_INODE_TB(fs, i, blk)) {
 572                                 FS_INODE_TB(fs, i) = 0;
 573                                 rfs->needed_blocks++;
 574                         } else if (ext2fs_test_block_bitmap(old_fs->block_map,
 575                                                             blk) &&
 576                                    !ext2fs_test_block_bitmap(meta_bmap, blk)) {
 577                                 ext2fs_mark_block_bitmap(rfs->move_blocks,
 578                                                          blk);
 579                                 rfs->needed_blocks++;
 580                         }
 581                 }
 582                 if (fs->group_desc[i].bg_inode_table &&
 583                     fs->group_desc[i].bg_inode_bitmap &&
 584                     fs->group_desc[i].bg_block_bitmap)
 585                         goto next_group;
 586
 587                 /*
 588                  * Reserve the existing meta blocks that we know
 589                  * aren't to be moved.
 590                  */
 591                 if (fs->group_desc[i].bg_block_bitmap)
 592                         ext2fs_mark_block_bitmap(rfs->reserve_blocks,
 593                                  fs->group_desc[i].bg_block_bitmap);
 594                 if (fs->group_desc[i].bg_inode_bitmap)
 595                         ext2fs_mark_block_bitmap(rfs->reserve_blocks,
 596                                  fs->group_desc[i].bg_inode_bitmap);
 597                 if (fs->group_desc[i].bg_inode_table)
 598                         for (blk = fs->group_desc[i].bg_inode_table, j=0;
 599                              j < fs->inode_blocks_per_group ; j++, blk++)
 600                                 ext2fs_mark_block_bitmap(rfs->reserve_blocks,
 601                                                          blk);
 602
 603                 /*
 604                  * Allocate the missing data structures
 605                  */
 606                 retval = ext2fs_allocate_group_table(fs, i,
 607                                                      rfs->reserve_blocks);
 608                 if (retval)
 609                         goto errout;
 610
 611                 /*
 612                  * For those structures that have changed, we need to
 613                  * do bookkeepping.
 614                  */
 615                 if (FS_BLOCK_BM(old_fs, i) !=
 616                     (blk = FS_BLOCK_BM(fs, i))) {
 617                         ext2fs_mark_block_bitmap(fs->block_map, blk);
 618                         if (ext2fs_test_block_bitmap(old_fs->block_map, blk) &&
 619                             !ext2fs_test_block_bitmap(meta_bmap, blk))
 620                                 ext2fs_mark_block_bitmap(rfs->move_blocks,
 621                                                          blk);
 622                 }
 623                 if (FS_INODE_BM(old_fs, i) !=
 624                     (blk = FS_INODE_BM(fs, i))) {
 625                         ext2fs_mark_block_bitmap(fs->block_map, blk);
 626                         if (ext2fs_test_block_bitmap(old_fs->block_map, blk) &&
 627                             !ext2fs_test_block_bitmap(meta_bmap, blk))
 628                                 ext2fs_mark_block_bitmap(rfs->move_blocks,
 629                                                          blk);
 630                 }
 631
 632                 /*
 633                  * The inode table, if we need to relocate it, is
 634                  * handled specially.  We have to reserve the blocks
 635                  * for both the old and the new inode table, since we
 636                  * can't have the inode table be destroyed during the
 637                  * block relocation phase.
 638                  */
 639                 if (FS_INODE_TB(fs, i) == FS_INODE_TB(old_fs, i))
 640                         goto next_group; /* inode table not moved */
 641
 642                 rfs->needed_blocks += fs->inode_blocks_per_group;
 643
 644                 /*
 645                  * Mark the new inode table as in use in the new block
 646                  * allocation bitmap, and move any blocks that might
 647                  * be necessary.
 648                  */
 649                 for (blk = fs->group_desc[i].bg_inode_table, j=0;
 650                      j < fs->inode_blocks_per_group ; j++, blk++) {
 651                         ext2fs_mark_block_bitmap(fs->block_map, blk);
 652                         if (ext2fs_test_block_bitmap(old_fs->block_map, blk) &&
 653                             !ext2fs_test_block_bitmap(meta_bmap, blk))
 654                                 ext2fs_mark_block_bitmap(rfs->move_blocks,
 655                                                          blk);
 656                 }
 657
 658                 /*
 659                  * Make sure the old inode table is reserved in the
 660                  * block reservation bitmap.
 661                  */
 662                 for (blk = rfs->old_fs->group_desc[i].bg_inode_table, j=0;
 663                      j < fs->inode_blocks_per_group ; j++, blk++)
 664                         ext2fs_mark_block_bitmap(rfs->reserve_blocks, blk);
 665
 666         next_group:
 667                 group_blk += rfs->new_fs->super->s_blocks_per_group;
 668         }
 669         retval = 0;
 670
 671 errout:
 672         if (meta_bmap)
 673                 ext2fs_free_block_bitmap(meta_bmap);
 674
 675         return retval;
 676 }
 677
 678 /*
 679  * This helper function tries to allocate a new block.  We try to
 680  * avoid hitting the original group descriptor blocks at least at
 681  * first, since we want to make it possible to recover from a badly
 682  * aborted resize operation as much as possible.
 683  *
 684  * In the future, I may further modify this routine to balance out
 685  * where we get the new blocks across the various block groups.
 686  * Ideally we would allocate blocks that corresponded with the block
 687  * group of the containing inode, and keep contiguous blocks
 688  * together.  However, this very difficult to do efficiently, since we
 689  * don't have the necessary information up front.
 690  */
 691
 692 #define AVOID_OLD       1
 693 #define DESPERATION     2
 694
 695 static void init_block_alloc(ext2_resize_t rfs)
 696 {
 697         rfs->alloc_state = AVOID_OLD;
 698         rfs->new_blk = rfs->new_fs->super->s_first_data_block;
 699 #if 0
 700         /* HACK for testing */
 701         if (rfs->new_fs->super->s_blocks_count >
 702             rfs->old_fs->super->s_blocks_count)
 703                 rfs->new_blk = rfs->old_fs->super->s_blocks_count;
 704 #endif
 705 }
 706
 707 static blk_t get_new_block(ext2_resize_t rfs)
 708 {
 709         ext2_filsys     fs = rfs->new_fs;
 710
 711         while (1) {
 712                 if (rfs->new_blk >= fs->super->s_blocks_count) {
 713                         if (rfs->alloc_state == DESPERATION)
 714                                 return 0;
 715
 716 #ifdef RESIZE2FS_DEBUG
 717                         if (rfs->flags & RESIZE_DEBUG_BMOVE)
 718                                 printf("Going into desperation "
 719                                        "mode for block allocations\n");
 720 #endif
 721                         rfs->alloc_state = DESPERATION;
 722                         rfs->new_blk = fs->super->s_first_data_block;
 723                         continue;
 724                 }
 725                 if (ext2fs_test_block_bitmap(fs->block_map, rfs->new_blk) ||
 726                     ext2fs_test_block_bitmap(rfs->reserve_blocks,
 727                                              rfs->new_blk) ||
 728                     ((rfs->alloc_state == AVOID_OLD) &&
 729                      (rfs->new_blk < rfs->old_fs->super->s_blocks_count) &&
 730                      ext2fs_test_block_bitmap(rfs->old_fs->block_map,
 731                                               rfs->new_blk))) {
 732                         rfs->new_blk++;
 733                         continue;
 734                 }
 735                 return rfs->new_blk;
 736         }
 737 }
 738
 739 static errcode_t block_mover(ext2_resize_t rfs)
 740 {
 741         blk_t                   blk, old_blk, new_blk;
 742         ext2_filsys             fs = rfs->new_fs;
 743         ext2_filsys             old_fs = rfs->old_fs;
 744         errcode_t               retval;
 745         int                     size, c;
 746         int                     to_move, moved;
 747
 748         new_blk = fs->super->s_first_data_block;
 749         if (!rfs->itable_buf) {
 750                 retval = ext2fs_get_mem(fs->blocksize *
 751                                         fs->inode_blocks_per_group,
 752                                         (void **) &rfs->itable_buf);
 753                 if (retval)
 754                         return retval;
 755         }
 756         retval = ext2fs_create_extent_table(&rfs->bmap, 0);
 757         if (retval)
 758                 return retval;
 759
 760         /*
 761          * The first step is to figure out where all of the blocks
 762          * will go.
 763          */
 764         to_move = moved = 0;
 765         init_block_alloc(rfs);
 766         for (blk = old_fs->super->s_first_data_block;
 767              blk < old_fs->super->s_blocks_count; blk++) {
 768                 if (!ext2fs_test_block_bitmap(old_fs->block_map, blk))
 769                         continue;
 770                 if (!ext2fs_test_block_bitmap(rfs->move_blocks, blk))
 771                         continue;
 772
 773                 new_blk = get_new_block(rfs);
 774                 if (!new_blk) {
 775                         retval = ENOSPC;
 776                         goto errout;
 777                 }
 778                 ext2fs_mark_block_bitmap(fs->block_map, new_blk);
 779                 ext2fs_add_extent_entry(rfs->bmap, blk, new_blk);
 780                 to_move++;
 781         }
 782
 783         if (to_move == 0) {
 784                 retval = 0;
 785                 goto errout;
 786         }
 787
 788         /*
 789          * Step two is to actually move the blocks
 790          */
 791         retval =  ext2fs_iterate_extent(rfs->bmap, 0, 0, 0);
 792         if (retval) goto errout;
 793
 794         if (rfs->progress) {
 795                 retval = (rfs->progress)(rfs, E2_RSZ_BLOCK_RELOC_PASS,
 796                                          0, to_move);
 797                 if (retval)
 798                         goto errout;
 799         }
 800         while (1) {
 801                 retval = ext2fs_iterate_extent(rfs->bmap, &old_blk, &new_blk, &size);
 802                 if (retval) goto errout;
 803                 if (!size)
 804                         break;
 805 #ifdef RESIZE2FS_DEBUG
 806                 if (rfs->flags & RESIZE_DEBUG_BMOVE)
 807                         printf("Moving %d blocks %u->%u\n", size,
 808                                old_blk, new_blk);
 809 #endif
 810                 do {
 811                         c = size;
 812                         if (c > fs->inode_blocks_per_group)
 813                                 c = fs->inode_blocks_per_group;
 814                         retval = io_channel_read_blk(fs->io, old_blk, c,
 815                                                      rfs->itable_buf);
 816                         if (retval) goto errout;
 817                         retval = io_channel_write_blk(fs->io, new_blk, c,
 818                                                       rfs->itable_buf);
 819                         if (retval) goto errout;
 820                         size -= c;
 821                         new_blk += c;
 822                         old_blk += c;
 823                         moved += c;
 824                         if (rfs->progress) {
 825                                 io_channel_flush(fs->io);
 826                                 retval = (rfs->progress)(rfs,
 827                                                 E2_RSZ_BLOCK_RELOC_PASS,
 828                                                 moved, to_move);
 829                                 if (retval)
 830                                         goto errout;
 831                         }
 832                 } while (size > 0);
 833                 io_channel_flush(fs->io);
 834         }
 835
 836 errout:
 837         return retval;
 838 }
 839
 840
 841 /* --------------------------------------------------------------------
 842  *
 843  * Resize processing, phase 3
 844  *
 845  * --------------------------------------------------------------------
 846  */
 847
 848
 849 struct process_block_struct {
 850         ext2_resize_t           rfs;
 851         ino_t                   ino;
 852         struct ext2_inode *     inode;
 853         errcode_t               error;
 854         int                     is_dir;
 855         int                     changed;
 856 };
 857
 858 static int process_block(ext2_filsys fs, blk_t  *block_nr,
 859                          int blockcnt, blk_t ref_block,
 860                          int ref_offset, void *priv_data)
 861 {
 862         struct process_block_struct *pb;
 863         errcode_t       retval;
 864         blk_t           block, new_block;
 865         int             ret = 0;
 866
 867         pb = (struct process_block_struct *) priv_data;
 868         block = *block_nr;
 869         if (pb->rfs->bmap) {
 870                 new_block = ext2fs_extent_translate(pb->rfs->bmap, block);
 871                 if (new_block) {
 872                         *block_nr = new_block;
 873                         ret |= BLOCK_CHANGED;
 874                         pb->changed = 1;
 875 #ifdef RESIZE2FS_DEBUG
 876                         if (pb->rfs->flags & RESIZE_DEBUG_BMOVE)
 877                                 printf("ino=%ld, blockcnt=%d, %u->%u\n",
 878                                        pb->ino, blockcnt, block, new_block);
 879 #endif
 880                         block = new_block;
 881                 }
 882         }
 883         if (pb->is_dir) {
 884                 retval = ext2fs_add_dir_block(fs->dblist, pb->ino,
 885                                               block, blockcnt);
 886                 if (retval) {
 887                         pb->error = retval;
 888                         ret |= BLOCK_ABORT;
 889                 }
 890         }
 891         return ret;
 892 }
 893
 894 /*
 895  * Progress callback
 896  */
 897 static errcode_t progress_callback(ext2_filsys fs, ext2_inode_scan scan,
 898                                    dgrp_t group, void * priv_data)
 899 {
 900         ext2_resize_t rfs = (ext2_resize_t) priv_data;
 901         errcode_t               retval;
 902
 903         /*
 904          * This check is to protect against old ext2 libraries.  It
 905          * shouldn't be needed against new libraries.
 906          */
 907         if ((group+1) == 0)
 908                 return 0;
 909
 910         if (rfs->progress) {
 911                 io_channel_flush(fs->io);
 912                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
 913                                          group+1, fs->group_desc_count);
 914                 if (retval)
 915                         return retval;
 916         }
 917
 918         return 0;
 919 }
 920
 921 static errcode_t inode_scan_and_fix(ext2_resize_t rfs)
 922 {
 923         struct process_block_struct     pb;
 924         ino_t                   ino, new_inode;
 925         struct ext2_inode       inode;
 926         ext2_inode_scan         scan = NULL;
 927         errcode_t               retval;
 928         int                     group;
 929         char                    *block_buf = 0;
 930         ino_t                   start_to_move;
 931         blk_t                   orig_size;
 932
 933         if ((rfs->old_fs->group_desc_count <=
 934              rfs->new_fs->group_desc_count) &&
 935             !rfs->bmap)
 936                 return 0;
 937
 938         /*
 939          * Save the original size of the old filesystem, and
 940          * temporarily set the size to be the new size if the new size
 941          * is larger.  We need to do this to avoid catching an error
 942          * by the block iterator routines
 943          */
 944         orig_size = rfs->old_fs->super->s_blocks_count;
 945         if (orig_size < rfs->new_fs->super->s_blocks_count)
 946                 rfs->old_fs->super->s_blocks_count =
 947                         rfs->new_fs->super->s_blocks_count;
 948
 949         retval = ext2fs_open_inode_scan(rfs->old_fs, 0, &scan);
 950         if (retval) goto errout;
 951
 952         retval = ext2fs_init_dblist(rfs->old_fs, 0);
 953         if (retval) goto errout;
 954         retval = ext2fs_get_mem(rfs->old_fs->blocksize * 3,
 955                                 (void **) &block_buf);
 956         if (retval) goto errout;
 957
 958         start_to_move = (rfs->new_fs->group_desc_count *
 959                          rfs->new_fs->super->s_inodes_per_group);
 960
 961         if (rfs->progress) {
 962                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
 963                                          0, rfs->old_fs->group_desc_count);
 964                 if (retval)
 965                         goto errout;
 966         }
 967         ext2fs_set_inode_callback(scan, progress_callback, (void *) rfs);
 968         pb.rfs = rfs;
 969         pb.inode = &inode;
 970         pb.error = 0;
 971         new_inode = EXT2_FIRST_INODE(rfs->new_fs->super);
 972         /*
 973          * First, copy all of the inodes that need to be moved
 974          * elsewhere in the inode table
 975          */
 976         while (1) {
 977                 retval = ext2fs_get_next_inode(scan, &ino, &inode);
 978                 if (retval) goto errout;
 979                 if (!ino)
 980                         break;
 981
 982                 if (inode.i_links_count == 0)
 983                         continue; /* inode not in use */
 984
 985                 pb.is_dir = LINUX_S_ISDIR(inode.i_mode);
 986                 pb.changed = 0;
 987
 988                 if (ext2fs_inode_has_valid_blocks(&inode) &&
 989                     (rfs->bmap || pb.is_dir)) {
 990                         pb.ino = ino;
 991                         retval = ext2fs_block_iterate2(rfs->old_fs,
 992                                                        ino, 0, block_buf,
 993                                                        process_block, &pb);
 994                         if (retval)
 995                                 goto errout;
 996                         if (pb.error) {
 997                                 retval = pb.error;
 998                                 goto errout;
 999                         }
1000                 }
1001
1002                 if (ino <= start_to_move)
1003                         continue; /* Don't need to move it. */
1004
1005                 /*
1006                  * Find a new inode
1007                  */
1008                 while (1) {
1009                         if (!ext2fs_test_inode_bitmap(rfs->new_fs->inode_map,
1010                                                       new_inode))
1011                                 break;
1012                         new_inode++;
1013                         if (new_inode > rfs->new_fs->super->s_inodes_count) {
1014                                 retval = ENOSPC;
1015                                 goto errout;
1016                         }
1017                 }
1018                 ext2fs_mark_inode_bitmap(rfs->new_fs->inode_map, new_inode);
1019                 if (pb.changed) {
1020                         /* Get the new version of the inode */
1021                         retval = ext2fs_read_inode(rfs->old_fs, ino, &inode);
1022                         if (retval) goto errout;
1023                 }
1024                 retval = ext2fs_write_inode(rfs->old_fs, new_inode, &inode);
1025                 if (retval) goto errout;
1026
1027                 group = (new_inode-1) / EXT2_INODES_PER_GROUP(rfs->new_fs->super);
1028                 if (LINUX_S_ISDIR(inode.i_mode))
1029                         rfs->new_fs->group_desc[group].bg_used_dirs_count++;
1030
1031 #ifdef RESIZE2FS_DEBUG
1032                 if (rfs->flags & RESIZE_DEBUG_INODEMAP)
1033                         printf("Inode moved %ld->%ld\n", ino, new_inode);
1034 #endif
1035                 if (!rfs->imap) {
1036                         retval = ext2fs_create_extent_table(&rfs->imap, 0);
1037                         if (retval)
1038                                 goto errout;
1039                 }
1040                 ext2fs_add_extent_entry(rfs->imap, ino, new_inode);
1041         }
1042         io_channel_flush(rfs->old_fs->io);
1043
1044 errout:
1045         rfs->old_fs->super->s_blocks_count = orig_size;
1046         if (rfs->bmap) {
1047                 ext2fs_free_extent_table(rfs->bmap);
1048                 rfs->bmap = 0;
1049         }
1050         if (scan)
1051                 ext2fs_close_inode_scan(scan);
1052         if (block_buf)
1053                 ext2fs_free_mem((void **) &block_buf);
1054         return retval;
1055 }
1056
1057 /* --------------------------------------------------------------------
1058  *
1059  * Resize processing, phase 4.
1060  *
1061  * --------------------------------------------------------------------
1062  */
1063
1064 struct istruct {
1065         ext2_resize_t rfs;
1066         errcode_t       err;
1067         unsigned long   max;
1068         int             num;
1069 };
1070
1071 static int check_and_change_inodes(ino_t dir, int entry,
1072                                    struct ext2_dir_entry *dirent, int offset,
1073                                    int  blocksize, char *buf, void *priv_data)
1074 {
1075         struct istruct *is = (struct istruct *) priv_data;
1076         ino_t           new_inode;
1077
1078         if (is->rfs->progress && offset == 0) {
1079                 io_channel_flush(is->rfs->old_fs->io);
1080                 is->err = (is->rfs->progress)(is->rfs,
1081                                               E2_RSZ_INODE_REF_UPD_PASS,
1082                                               ++is->num, is->max);
1083                 if (is->err)
1084                         return DIRENT_ABORT;
1085         }
1086
1087         if (!dirent->inode)
1088                 return 0;
1089
1090         new_inode = ext2fs_extent_translate(is->rfs->imap, dirent->inode);
1091
1092         if (!new_inode)
1093                 return 0;
1094 #ifdef RESIZE2FS_DEBUG
1095         if (is->rfs->flags & RESIZE_DEBUG_INODEMAP)
1096                 printf("Inode translate (dir=%ld, name=%.*s, %u->%ld)\n",
1097                        dir, dirent->name_len, dirent->name,
1098                        dirent->inode, new_inode);
1099 #endif
1100
1101         dirent->inode = new_inode;
1102
1103         return DIRENT_CHANGED;
1104 }
1105
1106 static errcode_t inode_ref_fix(ext2_resize_t rfs)
1107 {
1108         errcode_t               retval;
1109         struct istruct          is;
1110
1111         if (!rfs->imap)
1112                 return 0;
1113
1114         /*
1115          * Now, we iterate over all of the directories to update the
1116          * inode references
1117          */
1118         is.num = 0;
1119         is.max = ext2fs_dblist_count(rfs->old_fs->dblist);
1120         is.rfs = rfs;
1121         is.err = 0;
1122
1123         if (rfs->progress) {
1124                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS,
1125                                          0, is.max);
1126                 if (retval)
1127                         goto errout;
1128         }
1129
1130         retval = ext2fs_dblist_dir_iterate(rfs->old_fs->dblist,
1131                                            DIRENT_FLAG_INCLUDE_EMPTY, 0,
1132                                            check_and_change_inodes, &is);
1133         if (retval)
1134                 goto errout;
1135         if (is.err) {
1136                 retval = is.err;
1137                 goto errout;
1138         }
1139
1140 errout:
1141         ext2fs_free_extent_table(rfs->imap);
1142         rfs->imap = 0;
1143         return retval;
1144 }
1145
1146
1147 /* --------------------------------------------------------------------
1148  *
1149  * Resize processing, phase 5.
1150  *
1151  * In this phase we actually move the inode table around, and then
1152  * update the summary statistics.  This is scary, since aborting here
1153  * will potentially scramble the filesystem.  (We are moving the
1154  * inode tables around in place, and so the potential for lost data,
1155  * or at the very least scrambling the mapping between filenames and
1156  * inode numbers is very high in case of a power failure here.)
1157  * --------------------------------------------------------------------
1158  */
1159
1160
1161 /*
1162  * A very scary routine --- this one moves the inode table around!!!
1163  *
1164  * After this you have to use the rfs->new_fs file handle to read and
1165  * write inodes.
1166  */
1167 static errcode_t move_itables(ext2_resize_t rfs)
1168 {
1169         int             i, n, num, max, size, diff;
1170         ext2_filsys     fs = rfs->new_fs;
1171         char            *cp;
1172         blk_t           old_blk, new_blk;
1173         errcode_t       retval;
1174         int             to_move, moved;
1175
1176         max = fs->group_desc_count;
1177         if (max > rfs->old_fs->group_desc_count)
1178                 max = rfs->old_fs->group_desc_count;
1179
1180         size = fs->blocksize * fs->inode_blocks_per_group;
1181         if (!rfs->itable_buf) {
1182                 retval = ext2fs_get_mem(size, (void **) &rfs->itable_buf);
1183                 if (retval)
1184                         return retval;
1185         }
1186
1187         /*
1188          * Figure out how many inode tables we need to move
1189          */
1190         to_move = moved = 0;
1191         for (i=0; i < max; i++)
1192                 if (rfs->old_fs->group_desc[i].bg_inode_table !=
1193                     fs->group_desc[i].bg_inode_table)
1194                         to_move++;
1195
1196         if (to_move == 0)
1197                 return 0;
1198
1199         if (rfs->progress) {
1200                 retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
1201                                        0, to_move);
1202                 if (retval)
1203                         goto errout;
1204         }
1205
1206         rfs->old_fs->flags |= EXT2_FLAG_MASTER_SB_ONLY;
1207
1208         for (i=0; i < max; i++) {
1209                 old_blk = rfs->old_fs->group_desc[i].bg_inode_table;
1210                 new_blk = fs->group_desc[i].bg_inode_table;
1211                 diff = new_blk - old_blk;
1212
1213 #ifdef RESIZE2FS_DEBUG
1214                 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1215                         printf("Itable move group %d block "
1216                                "%u->%u (diff %d)\n",
1217                                i, old_blk, new_blk, diff);
1218 #endif
1219
1220                 if (!diff)
1221                         continue;
1222
1223                 retval = io_channel_read_blk(fs->io, old_blk,
1224                                              fs->inode_blocks_per_group,
1225                                              rfs->itable_buf);
1226                 if (retval)
1227                         goto errout;
1228                 /*
1229                  * The end of the inode table segment often contains
1230                  * all zeros, and we're often only moving the inode
1231                  * table down a block or two.  If so, we can optimize
1232                  * things by not rewriting blocks that we know to be zero
1233                  * already.
1234                  */
1235                 for (cp = rfs->itable_buf+size, n=0; n < size; n++, cp--)
1236                         if (*cp)
1237                                 break;
1238                 n = n >> EXT2_BLOCK_SIZE_BITS(fs->super);
1239 #ifdef RESIZE2FS_DEBUG
1240                 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1241                         printf("%d blocks of zeros...\n", n);
1242 #endif
1243                 num = fs->inode_blocks_per_group;
1244                 if (n > diff)
1245                         num -= n;
1246
1247                 retval = io_channel_write_blk(fs->io, new_blk,
1248                                               num, rfs->itable_buf);
1249                 if (retval) {
1250                         io_channel_write_blk(fs->io, old_blk,
1251                                              num, rfs->itable_buf);
1252                         goto errout;
1253                 }
1254                 if (n > diff) {
1255                         retval = io_channel_write_blk(fs->io,
1256                               old_blk + fs->inode_blocks_per_group,
1257                               diff, (rfs->itable_buf +
1258                                      (fs->inode_blocks_per_group - diff) *
1259                                      fs->blocksize));
1260                         if (retval)
1261                                 goto errout;
1262                 }
1263                 rfs->old_fs->group_desc[i].bg_inode_table = new_blk;
1264                 ext2fs_mark_super_dirty(rfs->old_fs);
1265                 if (rfs->progress) {
1266                         ext2fs_flush(rfs->old_fs);
1267                         retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
1268                                                ++moved, to_move);
1269                         if (retval)
1270                                 goto errout;
1271                 }
1272         }
1273         ext2fs_flush(fs);
1274 #ifdef RESIZE2FS_DEBUG
1275         if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1276                 printf("Inode table move finished.\n");
1277 #endif
1278         return 0;
1279
1280 errout:
1281         return retval;
1282 }
1283
1284 /*
1285  * Finally, recalculate the summary information
1286  */
1287 static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs)
1288 {
1289         blk_t   blk;
1290         ino_t   ino;
1291         int     group = 0;
1292         int     count = 0;
1293         int     total_free = 0;
1294         int     group_free = 0;
1295
1296         /*
1297          * First calculate the block statistics
1298          */
1299         for (blk = fs->super->s_first_data_block;
1300              blk < fs->super->s_blocks_count; blk++) {
1301                 if (!ext2fs_fast_test_block_bitmap(fs->block_map, blk)) {
1302                         group_free++;
1303                         total_free++;
1304                 }
1305                 count++;
1306                 if ((count == fs->super->s_blocks_per_group) ||
1307                     (blk == fs->super->s_blocks_count-1)) {
1308                         fs->group_desc[group++].bg_free_blocks_count =
1309                                 group_free;
1310                         count = 0;
1311                         group_free = 0;
1312                 }
1313         }
1314         fs->super->s_free_blocks_count = total_free;
1315
1316         /*
1317          * Next, calculate the inode statistics
1318          */
1319         group_free = 0;
1320         total_free = 0;
1321         count = 0;
1322         group = 0;
1323         for (ino = 1; ino <= fs->super->s_inodes_count; ino++) {
1324                 if (!ext2fs_fast_test_inode_bitmap(fs->inode_map, ino)) {
1325                         group_free++;
1326                         total_free++;
1327                 }
1328                 count++;
1329                 if ((count == fs->super->s_inodes_per_group) ||
1330                     (ino == fs->super->s_inodes_count)) {
1331                         fs->group_desc[group++].bg_free_inodes_count =
1332                                 group_free;
1333                         count = 0;
1334                         group_free = 0;
1335                 }
1336         }
1337         fs->super->s_free_inodes_count = total_free;
1338         ext2fs_mark_super_dirty(fs);
1339         return 0;
1340 }