resize/resize2fs.c

   1 /*
   2  * resize2fs.c --- ext2 main routine
   3  *
   4  * Copyright (C) 1997, 1998 by Theodore Ts'o and
   5  *      PowerQuest, Inc.
   6  *
   7  * Copyright (C) 1999, 2000 by Theosore Ts'o
   8  *
   9  * %Begin-Header%
  10  * This file may be redistributed under the terms of the GNU Public
  11  * License.
  12  * %End-Header%
  13  */
  14
  15 /*
  16  * Resizing a filesystem consists of the following phases:
  17  *
  18  *      1.  Adjust superblock and write out new parts of the inode
  19  *              table
  20  *      2.  Determine blocks which need to be relocated, and copy the
  21  *              contents of blocks from their old locations to the new ones.
  22  *      3.  Scan the inode table, doing the following:
  23  *              a.  If blocks have been moved, update the block
  24  *                      pointers in the inodes and indirect blocks to
  25  *                      point at the new block locations.
  26  *              b.  If parts of the inode table need to be evacuated,
  27  *                      copy inodes from their old locations to their
  28  *                      new ones.
  29  *              c.  If (b) needs to be done, note which blocks contain
  30  *                      directory information, since we will need to
  31  *                      update the directory information.
  32  *      4.  Update the directory blocks with the new inode locations.
  33  *      5.  Move the inode tables, if necessary.
  34  */
  35
  36 #include "config.h"
  37 #include "resize2fs.h"
  38 #include <time.h>
  39
  40 #ifdef __linux__                        /* Kludge for debugging */
  41 #define RESIZE2FS_DEBUG
  42 #endif
  43
  44 static void fix_uninit_block_bitmaps(ext2_filsys fs);
  45 static errcode_t adjust_superblock(ext2_resize_t rfs, blk64_t new_size);
  46 static errcode_t blocks_to_move(ext2_resize_t rfs);
  47 static errcode_t block_mover(ext2_resize_t rfs);
  48 static errcode_t inode_scan_and_fix(ext2_resize_t rfs);
  49 static errcode_t inode_ref_fix(ext2_resize_t rfs);
  50 static errcode_t move_itables(ext2_resize_t rfs);
  51 static errcode_t fix_resize_inode(ext2_filsys fs);
  52 static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs);
  53 static errcode_t fix_sb_journal_backup(ext2_filsys fs);
  54
  55 /*
  56  * Some helper CPP macros
  57  */
  58 #define IS_BLOCK_BM(fs, i, blk) ((blk) == ext2fs_block_bitmap_loc((fs),(i)))
  59 #define IS_INODE_BM(fs, i, blk) ((blk) == ext2fs_inode_bitmap_loc((fs),(i)))
  60
  61 #define IS_INODE_TB(fs, i, blk) (((blk) >= ext2fs_inode_table_loc((fs), (i))) && \
  62                                  ((blk) < (ext2fs_inode_table_loc((fs), (i)) + \
  63                                            (fs)->inode_blocks_per_group)))
  64
  65 int lazy_itable_init;
  66
  67 /*
  68  * This is the top-level routine which does the dirty deed....
  69  */
  70 errcode_t resize_fs(ext2_filsys fs, blk64_t *new_size, int flags,
  71             errcode_t (*progress)(ext2_resize_t rfs, int pass,
  72                                           unsigned long cur,
  73                                           unsigned long max_val))
  74 {
  75         ext2_resize_t   rfs;
  76         errcode_t       retval;
  77
  78         retval = ext2fs_read_bitmaps(fs);
  79         if (retval)
  80                 return retval;
  81
  82         fs->super->s_state |= EXT2_ERROR_FS;
  83         ext2fs_mark_super_dirty(fs);
  84         ext2fs_flush(fs);
  85
  86         /*
  87          * Create the data structure
  88          */
  89         retval = ext2fs_get_mem(sizeof(struct ext2_resize_struct), &rfs);
  90         if (retval)
  91                 return retval;
  92         memset(rfs, 0, sizeof(struct ext2_resize_struct));
  93
  94         fix_uninit_block_bitmaps(fs);
  95         fs->priv_data = rfs;
  96         rfs->old_fs = fs;
  97         rfs->flags = flags;
  98         rfs->itable_buf  = 0;
  99         rfs->progress = progress;
 100         retval = ext2fs_dup_handle(fs, &rfs->new_fs);
 101         if (retval)
 102                 goto errout;
 103
 104         retval = adjust_superblock(rfs, *new_size);
 105         if (retval)
 106                 goto errout;
 107
 108         fix_uninit_block_bitmaps(rfs->new_fs);
 109         /* Clear the block bitmap uninit flag for the last block group */
 110         ext2fs_bg_flags_clear(rfs->new_fs, rfs->new_fs->group_desc_count - 1,
 111                              EXT2_BG_BLOCK_UNINIT);
 112
 113         *new_size = ext2fs_blocks_count(rfs->new_fs->super);
 114
 115         retval = blocks_to_move(rfs);
 116         if (retval)
 117                 goto errout;
 118
 119 #ifdef RESIZE2FS_DEBUG
 120         if (rfs->flags & RESIZE_DEBUG_BMOVE)
 121                 printf("Number of free blocks: %llu/%llu, Needed: %llu\n",
 122                        ext2fs_free_blocks_count(rfs->old_fs->super),
 123                        ext2fs_free_blocks_count(rfs->new_fs->super),
 124                        rfs->needed_blocks);
 125 #endif
 126
 127         retval = block_mover(rfs);
 128         if (retval)
 129                 goto errout;
 130
 131         retval = inode_scan_and_fix(rfs);
 132         if (retval)
 133                 goto errout;
 134
 135         retval = inode_ref_fix(rfs);
 136         if (retval)
 137                 goto errout;
 138
 139         retval = move_itables(rfs);
 140         if (retval)
 141                 goto errout;
 142
 143         retval = ext2fs_calculate_summary_stats(rfs->new_fs);
 144         if (retval)
 145                 goto errout;
 146
 147         retval = fix_resize_inode(rfs->new_fs);
 148         if (retval)
 149                 goto errout;
 150
 151         retval = fix_sb_journal_backup(rfs->new_fs);
 152         if (retval)
 153                 goto errout;
 154
 155         rfs->new_fs->super->s_state &= ~EXT2_ERROR_FS;
 156         rfs->new_fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
 157         retval = ext2fs_close(rfs->new_fs);
 158         if (retval)
 159                 goto errout;
 160
 161         rfs->flags = flags;
 162
 163         ext2fs_free(rfs->old_fs);
 164         if (rfs->itable_buf)
 165                 ext2fs_free_mem(&rfs->itable_buf);
 166         if (rfs->reserve_blocks)
 167                 ext2fs_free_block_bitmap(rfs->reserve_blocks);
 168         if (rfs->move_blocks)
 169                 ext2fs_free_block_bitmap(rfs->move_blocks);
 170         ext2fs_free_mem(&rfs);
 171
 172         return 0;
 173
 174 errout:
 175         if (rfs->new_fs)
 176                 ext2fs_free(rfs->new_fs);
 177         if (rfs->itable_buf)
 178                 ext2fs_free_mem(&rfs->itable_buf);
 179         ext2fs_free_mem(&rfs);
 180         return retval;
 181 }
 182
 183 /*
 184  * Clean up the bitmaps for unitialized bitmaps
 185  */
 186 static void fix_uninit_block_bitmaps(ext2_filsys fs)
 187 {
 188         blk64_t         i, blk, super_blk, old_desc_blk, new_desc_blk;
 189         int             old_desc_blocks;
 190         dgrp_t          g;
 191
 192         if (!(EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 193                                          EXT4_FEATURE_RO_COMPAT_GDT_CSUM)))
 194                 return;
 195
 196         for (g=0; g < fs->group_desc_count; g++) {
 197                 if (!(ext2fs_bg_flags_test(fs, g, EXT2_BG_BLOCK_UNINIT)))
 198                         continue;
 199
 200                 blk = (g * fs->super->s_blocks_per_group) +
 201                         fs->super->s_first_data_block;
 202
 203                 ext2fs_super_and_bgd_loc2(fs, g, &super_blk,
 204                                           &old_desc_blk, &new_desc_blk, 0);
 205
 206                 if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
 207                         old_desc_blocks = fs->super->s_first_meta_bg;
 208                 else
 209                         old_desc_blocks = fs->desc_blocks +
 210                                 fs->super->s_reserved_gdt_blocks;
 211
 212                 for (i=0; i < fs->super->s_blocks_per_group; i++, blk++) {
 213                         if (blk >= ext2fs_blocks_count(fs->super))
 214                                 break;
 215                         if ((blk == super_blk) ||
 216                             (old_desc_blk && old_desc_blocks &&
 217                              (blk >= old_desc_blk) &&
 218                              (blk < old_desc_blk + old_desc_blocks)) ||
 219                             (new_desc_blk && (blk == new_desc_blk)) ||
 220                             (blk == ext2fs_block_bitmap_loc(fs, g)) ||
 221                             (blk == ext2fs_inode_bitmap_loc(fs, g)) ||
 222                             (blk >= ext2fs_inode_table_loc(fs, g) &&
 223                              (blk < ext2fs_inode_table_loc(fs, g)
 224                               + fs->inode_blocks_per_group)))
 225                                 ext2fs_fast_mark_block_bitmap2(fs->block_map, blk);
 226                         else
 227                                 ext2fs_fast_unmark_block_bitmap2(fs->block_map, blk);
 228                 }
 229         }
 230 }
 231
 232 /* --------------------------------------------------------------------
 233  *
 234  * Resize processing, phase 1.
 235  *
 236  * In this phase we adjust the in-memory superblock information, and
 237  * initialize any new parts of the inode table.  The new parts of the
 238  * inode table are created in virgin disk space, so we can abort here
 239  * without any side effects.
 240  * --------------------------------------------------------------------
 241  */
 242
 243 /*
 244  * If the group descriptor's bitmap and inode table blocks are valid,
 245  * release them in the new filesystem data structure, and mark them as
 246  * reserved so the old inode table blocks don't get overwritten.
 247  */
 248 static void free_gdp_blocks(ext2_filsys fs,
 249                             ext2fs_block_bitmap reserve_blocks,
 250                             struct ext2_group_desc *gdp)
 251 {
 252         blk_t   blk;
 253         int     j;
 254
 255         if (gdp->bg_block_bitmap &&
 256             (gdp->bg_block_bitmap < ext2fs_blocks_count(fs->super))) {
 257                 ext2fs_block_alloc_stats(fs, gdp->bg_block_bitmap, -1);
 258                 ext2fs_mark_block_bitmap2(reserve_blocks,
 259                                          gdp->bg_block_bitmap);
 260         }
 261
 262         if (gdp->bg_inode_bitmap &&
 263             (gdp->bg_inode_bitmap < ext2fs_blocks_count(fs->super))) {
 264                 ext2fs_block_alloc_stats(fs, gdp->bg_inode_bitmap, -1);
 265                 ext2fs_mark_block_bitmap2(reserve_blocks,
 266                                          gdp->bg_inode_bitmap);
 267         }
 268
 269         if (gdp->bg_inode_table == 0 ||
 270             (gdp->bg_inode_table >= ext2fs_blocks_count(fs->super)))
 271                 return;
 272
 273         for (blk = gdp->bg_inode_table, j = 0;
 274              j < fs->inode_blocks_per_group; j++, blk++) {
 275                 if (blk >= ext2fs_blocks_count(fs->super))
 276                         break;
 277                 ext2fs_block_alloc_stats(fs, blk, -1);
 278                 ext2fs_mark_block_bitmap2(reserve_blocks, blk);
 279         }
 280 }
 281
 282 /*
 283  * This routine is shared by the online and offline resize routines.
 284  * All of the information which is adjusted in memory is done here.
 285  *
 286  * The reserve_blocks parameter is only needed when shrinking the
 287  * filesystem.
 288  */
 289 errcode_t adjust_fs_info(ext2_filsys fs, ext2_filsys old_fs,
 290                          ext2fs_block_bitmap reserve_blocks, blk64_t new_size)
 291 {
 292         errcode_t       retval;
 293         blk64_t         overhead = 0;
 294         blk64_t         rem;
 295         blk64_t         blk, group_block;
 296         blk64_t         real_end;
 297         blk64_t         adj, old_numblocks, numblocks, adjblocks;
 298         unsigned long   i, j, old_desc_blocks, max_group;
 299         unsigned int    meta_bg, meta_bg_size;
 300         int             has_super, csum_flag;
 301         unsigned long long new_inodes;  /* u64 to check for overflow */
 302         double          percent;
 303
 304         ext2fs_blocks_count_set(fs->super, new_size);
 305
 306 retry:
 307         fs->group_desc_count = ext2fs_div64_ceil(ext2fs_blocks_count(fs->super) -
 308                                        fs->super->s_first_data_block,
 309                                        EXT2_BLOCKS_PER_GROUP(fs->super));
 310         if (fs->group_desc_count == 0)
 311                 return EXT2_ET_TOOSMALL;
 312         fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count,
 313                                           EXT2_DESC_PER_BLOCK(fs->super));
 314
 315         /*
 316          * Overhead is the number of bookkeeping blocks per group.  It
 317          * includes the superblock backup, the group descriptor
 318          * backups, the inode bitmap, the block bitmap, and the inode
 319          * table.
 320          */
 321         overhead = (int) (2 + fs->inode_blocks_per_group);
 322
 323         if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1))
 324                 overhead += 1 + fs->desc_blocks +
 325                         fs->super->s_reserved_gdt_blocks;
 326
 327         /*
 328          * See if the last group is big enough to support the
 329          * necessary data structures.  If not, we need to get rid of
 330          * it.
 331          */
 332         rem = (ext2fs_blocks_count(fs->super) - fs->super->s_first_data_block) %
 333                 fs->super->s_blocks_per_group;
 334         if ((fs->group_desc_count == 1) && rem && (rem < overhead))
 335                 return EXT2_ET_TOOSMALL;
 336         if ((fs->group_desc_count > 1) && rem && (rem < overhead+50)) {
 337                 ext2fs_blocks_count_set(fs->super,
 338                                         ext2fs_blocks_count(fs->super) - rem);
 339                 goto retry;
 340         }
 341         /*
 342          * Adjust the number of inodes
 343          */
 344         new_inodes =(unsigned long long) fs->super->s_inodes_per_group * fs->group_desc_count;
 345         if (new_inodes > ~0U) {
 346                 fprintf(stderr, _("inodes (%llu) must be less than %u"),
 347                                    new_inodes, ~0U);
 348                 return EXT2_ET_TOO_MANY_INODES;
 349         }
 350         fs->super->s_inodes_count = fs->super->s_inodes_per_group *
 351                 fs->group_desc_count;
 352
 353         /*
 354          * Adjust the number of free blocks
 355          */
 356         blk = ext2fs_blocks_count(old_fs->super);
 357         if (blk > ext2fs_blocks_count(fs->super))
 358                 ext2fs_free_blocks_count_set(fs->super,
 359                         ext2fs_free_blocks_count(fs->super) -
 360                         (blk - ext2fs_blocks_count(fs->super)));
 361         else
 362                 ext2fs_free_blocks_count_set(fs->super,
 363                         ext2fs_free_blocks_count(fs->super) +
 364                         (ext2fs_blocks_count(fs->super) - blk));
 365
 366         /*
 367          * Adjust the number of reserved blocks
 368          */
 369         percent = (ext2fs_r_blocks_count(old_fs->super) * 100.0) /
 370                 ext2fs_blocks_count(old_fs->super);
 371         ext2fs_r_blocks_count_set(fs->super,
 372                                   (percent * ext2fs_blocks_count(fs->super) /
 373                                    100.0));
 374
 375         /*
 376          * Adjust the bitmaps for size
 377          */
 378         retval = ext2fs_resize_inode_bitmap2(fs->super->s_inodes_count,
 379                                             fs->super->s_inodes_count,
 380                                             fs->inode_map);
 381         if (retval) goto errout;
 382
 383         real_end = (((blk64_t) EXT2_BLOCKS_PER_GROUP(fs->super) *
 384                      fs->group_desc_count)) - 1 +
 385                 fs->super->s_first_data_block;
 386         retval = ext2fs_resize_block_bitmap2(ext2fs_blocks_count(fs->super)-1,
 387                                             real_end, fs->block_map);
 388
 389         if (retval) goto errout;
 390
 391         /*
 392          * Reallocate the group descriptors as necessary.
 393          */
 394         if (old_fs->desc_blocks != fs->desc_blocks) {
 395                 retval = ext2fs_resize_mem(old_fs->desc_blocks *
 396                                            fs->blocksize,
 397                                            fs->desc_blocks * fs->blocksize,
 398                                            &fs->group_desc);
 399                 if (retval)
 400                         goto errout;
 401                 if (fs->desc_blocks > old_fs->desc_blocks)
 402                         memset((char *) fs->group_desc +
 403                                (old_fs->desc_blocks * fs->blocksize), 0,
 404                                (fs->desc_blocks - old_fs->desc_blocks) *
 405                                fs->blocksize);
 406         }
 407
 408         /*
 409          * If the resize_inode feature is set, and we are changing the
 410          * number of descriptor blocks, then adjust
 411          * s_reserved_gdt_blocks if possible to avoid needing to move
 412          * the inode table either now or in the future.
 413          */
 414         if ((fs->super->s_feature_compat &
 415              EXT2_FEATURE_COMPAT_RESIZE_INODE) &&
 416             (old_fs->desc_blocks != fs->desc_blocks)) {
 417                 int new;
 418
 419                 new = ((int) fs->super->s_reserved_gdt_blocks) +
 420                         (old_fs->desc_blocks - fs->desc_blocks);
 421                 if (new < 0)
 422                         new = 0;
 423                 if (new > (int) fs->blocksize/4)
 424                         new = fs->blocksize/4;
 425                 fs->super->s_reserved_gdt_blocks = new;
 426         }
 427
 428         /*
 429          * If we are shrinking the number of block groups, we're done
 430          * and can exit now.
 431          */
 432         if (old_fs->group_desc_count > fs->group_desc_count) {
 433                 /*
 434                  * Check the block groups that we are chopping off
 435                  * and free any blocks associated with their metadata
 436                  */
 437                 for (i = fs->group_desc_count;
 438                      i < old_fs->group_desc_count; i++) {
 439                         free_gdp_blocks(fs, reserve_blocks,
 440                                         ext2fs_group_desc(old_fs,
 441                                                 old_fs->group_desc, i));
 442                 }
 443                 retval = 0;
 444                 goto errout;
 445         }
 446
 447         /*
 448          * Fix the count of the last (old) block group
 449          */
 450         old_numblocks = (ext2fs_blocks_count(old_fs->super) -
 451                          old_fs->super->s_first_data_block) %
 452                                  old_fs->super->s_blocks_per_group;
 453         if (!old_numblocks)
 454                 old_numblocks = old_fs->super->s_blocks_per_group;
 455         if (old_fs->group_desc_count == fs->group_desc_count) {
 456                 numblocks = (ext2fs_blocks_count(fs->super) -
 457                              fs->super->s_first_data_block) %
 458                         fs->super->s_blocks_per_group;
 459                 if (!numblocks)
 460                         numblocks = fs->super->s_blocks_per_group;
 461         } else
 462                 numblocks = fs->super->s_blocks_per_group;
 463         i = old_fs->group_desc_count - 1;
 464         ext2fs_bg_free_blocks_count_set(fs, i, ext2fs_bg_free_blocks_count(fs, i) + (numblocks - old_numblocks));
 465         ext2fs_group_desc_csum_set(fs, i);
 466
 467         /*
 468          * If the number of block groups is staying the same, we're
 469          * done and can exit now.  (If the number block groups is
 470          * shrinking, we had exited earlier.)
 471          */
 472         if (old_fs->group_desc_count >= fs->group_desc_count) {
 473                 retval = 0;
 474                 goto errout;
 475         }
 476
 477         /*
 478          * Initialize the new block group descriptors
 479          */
 480         group_block = fs->super->s_first_data_block +
 481                 old_fs->group_desc_count * fs->super->s_blocks_per_group;
 482
 483         csum_flag = EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 484                                                EXT4_FEATURE_RO_COMPAT_GDT_CSUM);
 485         if (access("/sys/fs/ext4/features/lazy_itable_init", F_OK) == 0)
 486                 lazy_itable_init = 1;
 487         adj = old_fs->group_desc_count;
 488         max_group = fs->group_desc_count - adj;
 489         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
 490                 old_desc_blocks = fs->super->s_first_meta_bg;
 491         else
 492                 old_desc_blocks = fs->desc_blocks +
 493                         fs->super->s_reserved_gdt_blocks;
 494         for (i = old_fs->group_desc_count;
 495              i < fs->group_desc_count; i++) {
 496                 memset(ext2fs_group_desc(fs, fs->group_desc, i), 0,
 497                        sizeof(struct ext2_group_desc));
 498                 adjblocks = 0;
 499
 500                 ext2fs_bg_flags_zap(fs, i);
 501                 if (csum_flag) {
 502                         ext2fs_bg_flags_set(fs, i, EXT2_BG_INODE_UNINIT);
 503                         if (!lazy_itable_init)
 504                                 ext2fs_bg_flags_set(fs, i,
 505                                                     EXT2_BG_INODE_ZEROED);
 506                         ext2fs_bg_itable_unused_set(fs, i,
 507                                         fs->super->s_inodes_per_group);
 508                 }
 509
 510                 numblocks = ext2fs_group_blocks_count(fs, i);
 511                 if ((i < fs->group_desc_count - 1) && csum_flag)
 512                         ext2fs_bg_flags_set(fs, i, EXT2_BG_BLOCK_UNINIT);
 513
 514                 has_super = ext2fs_bg_has_super(fs, i);
 515                 if (has_super) {
 516                         ext2fs_block_alloc_stats2(fs, group_block, +1);
 517                         adjblocks++;
 518                 }
 519                 meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
 520                 meta_bg = i / meta_bg_size;
 521                 if (!(fs->super->s_feature_incompat &
 522                       EXT2_FEATURE_INCOMPAT_META_BG) ||
 523                     (meta_bg < fs->super->s_first_meta_bg)) {
 524                         if (has_super) {
 525                                 for (j=0; j < old_desc_blocks; j++)
 526                                         ext2fs_block_alloc_stats2(fs,
 527                                                  group_block + 1 + j, +1);
 528                                 adjblocks += old_desc_blocks;
 529                         }
 530                 } else {
 531                         if (has_super)
 532                                 has_super = 1;
 533                         if (((i % meta_bg_size) == 0) ||
 534                             ((i % meta_bg_size) == 1) ||
 535                             ((i % meta_bg_size) == (meta_bg_size-1)))
 536                                 ext2fs_block_alloc_stats2(fs,
 537                                                  group_block + has_super, +1);
 538                 }
 539
 540                 adjblocks += 2 + fs->inode_blocks_per_group;
 541
 542                 numblocks -= adjblocks;
 543                 ext2fs_free_blocks_count_set(fs->super,
 544                              ext2fs_free_blocks_count(fs->super) - adjblocks);
 545                 fs->super->s_free_inodes_count +=
 546                         fs->super->s_inodes_per_group;
 547                 ext2fs_bg_free_blocks_count_set(fs, i, numblocks);
 548                 ext2fs_bg_free_inodes_count_set(fs, i,
 549                                                 fs->super->s_inodes_per_group);
 550                 ext2fs_bg_used_dirs_count_set(fs, i, 0);
 551                 ext2fs_group_desc_csum_set(fs, i);
 552
 553                 retval = ext2fs_allocate_group_table(fs, i, 0);
 554                 if (retval) goto errout;
 555
 556                 group_block += fs->super->s_blocks_per_group;
 557         }
 558         retval = 0;
 559
 560 errout:
 561         return (retval);
 562 }
 563
 564 /*
 565  * This routine adjusts the superblock and other data structures, both
 566  * in disk as well as in memory...
 567  */
 568 static errcode_t adjust_superblock(ext2_resize_t rfs, blk64_t new_size)
 569 {
 570         ext2_filsys fs;
 571         int             adj = 0;
 572         errcode_t       retval;
 573         blk64_t         group_block;
 574         unsigned long   i;
 575         unsigned long   max_group;
 576
 577         fs = rfs->new_fs;
 578         ext2fs_mark_super_dirty(fs);
 579         ext2fs_mark_bb_dirty(fs);
 580         ext2fs_mark_ib_dirty(fs);
 581
 582         retval = ext2fs_allocate_block_bitmap(fs, _("reserved blocks"),
 583                                               &rfs->reserve_blocks);
 584         if (retval)
 585                 return retval;
 586
 587         retval = adjust_fs_info(fs, rfs->old_fs, rfs->reserve_blocks, new_size);
 588         if (retval)
 589                 goto errout;
 590
 591         /*
 592          * Check to make sure there are enough inodes
 593          */
 594         if ((rfs->old_fs->super->s_inodes_count -
 595              rfs->old_fs->super->s_free_inodes_count) >
 596             rfs->new_fs->super->s_inodes_count) {
 597                 retval = ENOSPC;
 598                 goto errout;
 599         }
 600
 601         /*
 602          * If we are shrinking the number block groups, we're done and
 603          * can exit now.
 604          */
 605         if (rfs->old_fs->group_desc_count > fs->group_desc_count) {
 606                 retval = 0;
 607                 goto errout;
 608         }
 609
 610         /*
 611          * If the number of block groups is staying the same, we're
 612          * done and can exit now.  (If the number block groups is
 613          * shrinking, we had exited earlier.)
 614          */
 615         if (rfs->old_fs->group_desc_count >= fs->group_desc_count) {
 616                 retval = 0;
 617                 goto errout;
 618         }
 619
 620         /*
 621          * If we are using uninit_bg (aka GDT_CSUM) and the kernel
 622          * supports lazy inode initialization, we can skip
 623          * initializing the inode table.
 624          */
 625         if (lazy_itable_init &&
 626             EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 627                                        EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
 628                 retval = 0;
 629                 goto errout;
 630         }
 631
 632         /*
 633          * Initialize the inode table
 634          */
 635         retval = ext2fs_get_array(fs->blocksize, fs->inode_blocks_per_group,
 636                                 &rfs->itable_buf);
 637         if (retval)
 638                 goto errout;
 639
 640         memset(rfs->itable_buf, 0, fs->blocksize * fs->inode_blocks_per_group);
 641         group_block = fs->super->s_first_data_block +
 642                 rfs->old_fs->group_desc_count * fs->super->s_blocks_per_group;
 643
 644         adj = rfs->old_fs->group_desc_count;
 645         max_group = fs->group_desc_count - adj;
 646         if (rfs->progress) {
 647                 retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
 648                                        0, max_group);
 649                 if (retval)
 650                         goto errout;
 651         }
 652         for (i = rfs->old_fs->group_desc_count;
 653              i < fs->group_desc_count; i++) {
 654                 /*
 655                  * Write out the new inode table
 656                  */
 657                 retval = io_channel_write_blk64(fs->io,
 658                                                 ext2fs_inode_table_loc(fs, i),
 659                                                 fs->inode_blocks_per_group,
 660                                                 rfs->itable_buf);
 661                 if (retval) goto errout;
 662
 663                 io_channel_flush(fs->io);
 664                 if (rfs->progress) {
 665                         retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
 666                                                i - adj + 1, max_group);
 667                         if (retval)
 668                                 goto errout;
 669                 }
 670                 group_block += fs->super->s_blocks_per_group;
 671         }
 672         io_channel_flush(fs->io);
 673         retval = 0;
 674
 675 errout:
 676         return retval;
 677 }
 678
 679 /* --------------------------------------------------------------------
 680  *
 681  * Resize processing, phase 2.
 682  *
 683  * In this phase we adjust determine which blocks need to be moved, in
 684  * blocks_to_move().  We then copy the blocks to their ultimate new
 685  * destinations using block_mover().  Since we are copying blocks to
 686  * their new locations, again during this pass we can abort without
 687  * any problems.
 688  * --------------------------------------------------------------------
 689  */
 690
 691 /*
 692  * This helper function creates a block bitmap with all of the
 693  * filesystem meta-data blocks.
 694  */
 695 static errcode_t mark_table_blocks(ext2_filsys fs,
 696                                    ext2fs_block_bitmap bmap)
 697 {
 698         blk64_t                 b;
 699         unsigned int            j;
 700         dgrp_t                  i;
 701         unsigned long           meta_bg_size;
 702         unsigned int            old_desc_blocks;
 703
 704         meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
 705         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
 706                 old_desc_blocks = fs->super->s_first_meta_bg;
 707         else
 708                 old_desc_blocks = fs->desc_blocks +
 709                         fs->super->s_reserved_gdt_blocks;
 710         for (i = 0; i < fs->group_desc_count; i++) {
 711                 ext2fs_reserve_super_and_bgd(fs, i, bmap);
 712
 713                 /*
 714                  * Mark the blocks used for the inode table
 715                  */
 716                 for (j = 0, b = ext2fs_inode_table_loc(fs, i);
 717                      j < (unsigned int) fs->inode_blocks_per_group;
 718                      j++, b++)
 719                         ext2fs_mark_block_bitmap2(bmap, b);
 720
 721                 /*
 722                  * Mark block used for the block bitmap
 723                  */
 724                 ext2fs_mark_block_bitmap2(bmap,
 725                                          ext2fs_block_bitmap_loc(fs, i));
 726
 727                 /*
 728                  * Mark block used for the inode bitmap
 729                  */
 730                 ext2fs_mark_block_bitmap2(bmap,
 731                                          ext2fs_inode_bitmap_loc(fs, i));
 732         }
 733         return 0;
 734 }
 735
 736 /*
 737  * This function checks to see if a particular block (either a
 738  * superblock or a block group descriptor) overlaps with an inode or
 739  * block bitmap block, or with the inode table.
 740  */
 741 static void mark_fs_metablock(ext2_resize_t rfs,
 742                               ext2fs_block_bitmap meta_bmap,
 743                               int group, blk64_t blk)
 744 {
 745         ext2_filsys     fs = rfs->new_fs;
 746
 747         ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
 748         ext2fs_block_alloc_stats2(fs, blk, +1);
 749
 750         /*
 751          * Check to see if we overlap with the inode or block bitmap,
 752          * or the inode tables.  If not, and the block is in use, then
 753          * mark it as a block to be moved.
 754          */
 755         if (IS_BLOCK_BM(fs, group, blk)) {
 756                 ext2fs_block_bitmap_loc_set(fs, group, 0);
 757                 rfs->needed_blocks++;
 758         } else if (IS_INODE_BM(fs, group, blk)) {
 759                 ext2fs_inode_bitmap_loc_set(fs, group, 0);
 760                 rfs->needed_blocks++;
 761         } else if (IS_INODE_TB(fs, group, blk)) {
 762                 ext2fs_inode_table_loc_set(fs, group, 0);
 763                 rfs->needed_blocks++;
 764         } else if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 765                                               EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
 766                    (ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT))) {
 767                 /*
 768                  * If the block bitmap is uninitialized, which means
 769                  * nothing other than standard metadata in use.
 770                  */
 771                 return;
 772         } else if (ext2fs_test_block_bitmap2(rfs->old_fs->block_map, blk) &&
 773                    !ext2fs_test_block_bitmap2(meta_bmap, blk)) {
 774                 ext2fs_mark_block_bitmap2(rfs->move_blocks, blk);
 775                 rfs->needed_blocks++;
 776         }
 777 }
 778
 779
 780 /*
 781  * This routine marks and unmarks reserved blocks in the new block
 782  * bitmap.  It also determines which blocks need to be moved and
 783  * places this information into the move_blocks bitmap.
 784  */
 785 static errcode_t blocks_to_move(ext2_resize_t rfs)
 786 {
 787         int             j, has_super;
 788         dgrp_t          i, max_groups, g;
 789         blk64_t         blk, group_blk;
 790         blk64_t         old_blocks, new_blocks;
 791         unsigned int    meta_bg, meta_bg_size;
 792         errcode_t       retval;
 793         ext2_filsys     fs, old_fs;
 794         ext2fs_block_bitmap     meta_bmap;
 795         __u32           save_incompat_flag;
 796
 797         fs = rfs->new_fs;
 798         old_fs = rfs->old_fs;
 799         if (ext2fs_blocks_count(old_fs->super) > ext2fs_blocks_count(fs->super))
 800                 fs = rfs->old_fs;
 801
 802         retval = ext2fs_allocate_block_bitmap(fs, _("blocks to be moved"),
 803                                               &rfs->move_blocks);
 804         if (retval)
 805                 return retval;
 806
 807         retval = ext2fs_allocate_block_bitmap(fs, _("meta-data blocks"),
 808                                               &meta_bmap);
 809         if (retval)
 810                 return retval;
 811
 812         retval = mark_table_blocks(old_fs, meta_bmap);
 813         if (retval)
 814                 return retval;
 815
 816         fs = rfs->new_fs;
 817
 818         /*
 819          * If we're shrinking the filesystem, we need to move all of
 820          * the blocks that don't fit any more
 821          */
 822         for (blk = ext2fs_blocks_count(fs->super);
 823              blk < ext2fs_blocks_count(old_fs->super); blk++) {
 824                 g = ext2fs_group_of_blk2(fs, blk);
 825                 if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 826                                                EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
 827                     ext2fs_bg_flags_test(old_fs, g, EXT2_BG_BLOCK_UNINIT)) {
 828                         /*
 829                          * The block bitmap is uninitialized, so skip
 830                          * to the next block group.
 831                          */
 832                         blk = ((g+1) * fs->super->s_blocks_per_group) +
 833                                 fs->super->s_first_data_block - 1;
 834                         continue;
 835                 }
 836                 if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
 837                     !ext2fs_test_block_bitmap2(meta_bmap, blk)) {
 838                         ext2fs_mark_block_bitmap2(rfs->move_blocks, blk);
 839                         rfs->needed_blocks++;
 840                 }
 841                 ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
 842         }
 843
 844         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) {
 845                 old_blocks = old_fs->super->s_first_meta_bg;
 846                 new_blocks = fs->super->s_first_meta_bg;
 847         } else {
 848                 old_blocks = old_fs->desc_blocks + old_fs->super->s_reserved_gdt_blocks;
 849                 new_blocks = fs->desc_blocks + fs->super->s_reserved_gdt_blocks;
 850         }
 851
 852         if (old_blocks == new_blocks) {
 853                 retval = 0;
 854                 goto errout;
 855         }
 856
 857         max_groups = fs->group_desc_count;
 858         if (max_groups > old_fs->group_desc_count)
 859                 max_groups = old_fs->group_desc_count;
 860         group_blk = old_fs->super->s_first_data_block;
 861         /*
 862          * If we're reducing the number of descriptor blocks, this
 863          * makes life easy.  :-)   We just have to mark some extra
 864          * blocks as free.
 865          */
 866         if (old_blocks > new_blocks) {
 867                 for (i = 0; i < max_groups; i++) {
 868                         if (!ext2fs_bg_has_super(fs, i)) {
 869                                 group_blk += fs->super->s_blocks_per_group;
 870                                 continue;
 871                         }
 872                         for (blk = group_blk+1+new_blocks;
 873                              blk < group_blk+1+old_blocks; blk++) {
 874                                 ext2fs_block_alloc_stats2(fs, blk, -1);
 875                                 rfs->needed_blocks--;
 876                         }
 877                         group_blk += fs->super->s_blocks_per_group;
 878                 }
 879                 retval = 0;
 880                 goto errout;
 881         }
 882         /*
 883          * If we're increasing the number of descriptor blocks, life
 884          * gets interesting....
 885          */
 886         meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
 887         for (i = 0; i < max_groups; i++) {
 888                 has_super = ext2fs_bg_has_super(fs, i);
 889                 if (has_super)
 890                         mark_fs_metablock(rfs, meta_bmap, i, group_blk);
 891
 892                 meta_bg = i / meta_bg_size;
 893                 if (!(fs->super->s_feature_incompat &
 894                       EXT2_FEATURE_INCOMPAT_META_BG) ||
 895                     (meta_bg < fs->super->s_first_meta_bg)) {
 896                         if (has_super) {
 897                                 for (blk = group_blk+1;
 898                                      blk < group_blk + 1 + new_blocks; blk++)
 899                                         mark_fs_metablock(rfs, meta_bmap,
 900                                                           i, blk);
 901                         }
 902                 } else {
 903                         if (has_super)
 904                                 has_super = 1;
 905                         if (((i % meta_bg_size) == 0) ||
 906                             ((i % meta_bg_size) == 1) ||
 907                             ((i % meta_bg_size) == (meta_bg_size-1)))
 908                                 mark_fs_metablock(rfs, meta_bmap, i,
 909                                                   group_blk + has_super);
 910                 }
 911
 912                 if (ext2fs_inode_table_loc(fs, i) &&
 913                     ext2fs_inode_bitmap_loc(fs, i) &&
 914                     ext2fs_block_bitmap_loc(fs, i))
 915                         goto next_group;
 916
 917                 /*
 918                  * Reserve the existing meta blocks that we know
 919                  * aren't to be moved.
 920                  */
 921                 if (ext2fs_block_bitmap_loc(fs, i))
 922                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
 923                                  ext2fs_block_bitmap_loc(fs, i));
 924                 if (ext2fs_inode_bitmap_loc(fs, i))
 925                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
 926                                  ext2fs_inode_bitmap_loc(fs, i));
 927                 if (ext2fs_inode_table_loc(fs, i))
 928                         for (blk = ext2fs_inode_table_loc(fs, i), j=0;
 929                              j < fs->inode_blocks_per_group ; j++, blk++)
 930                                 ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
 931                                                          blk);
 932
 933                 /*
 934                  * Allocate the missing data structures
 935                  *
 936                  * XXX We have a problem with FLEX_BG and off-line
 937                  * resizing where we are growing the size of the
 938                  * filesystem.  ext2fs_allocate_group_table() will try
 939                  * to reserve the inode table in the desired flex_bg
 940                  * location.  However, passing rfs->reserve_blocks
 941                  * doesn't work since it only has reserved the blocks
 942                  * that will be used in the new block group -- and
 943                  * with flex_bg, we can and will allocate the tables
 944                  * outside of the block group.  And we can't pass in
 945                  * the fs->block_map because it doesn't handle
 946                  * overlapping inode table movements right.  So for
 947                  * now, we temporarily disable flex_bg to force
 948                  * ext2fs_allocate_group_tables() to allocate the bg
 949                  * metadata in side the block group, and the restore
 950                  * it afterwards.  Ugly, until we can fix this up
 951                  * right later.
 952                  */
 953                 save_incompat_flag = fs->super->s_feature_incompat;
 954                 fs->super->s_feature_incompat &= ~EXT4_FEATURE_INCOMPAT_FLEX_BG;
 955                 retval = ext2fs_allocate_group_table(fs, i,
 956                                                      rfs->reserve_blocks);
 957                 fs->super->s_feature_incompat = save_incompat_flag;
 958                 if (retval)
 959                         goto errout;
 960
 961                 /*
 962                  * For those structures that have changed, we need to
 963                  * do bookkeepping.
 964                  */
 965                 if (ext2fs_block_bitmap_loc(old_fs, i) !=
 966                     (blk = ext2fs_block_bitmap_loc(fs, i))) {
 967                         ext2fs_block_alloc_stats2(fs, blk, +1);
 968                         if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
 969                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
 970                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
 971                                                          blk);
 972                 }
 973                 if (ext2fs_inode_bitmap_loc(old_fs, i) !=
 974                     (blk = ext2fs_inode_bitmap_loc(fs, i))) {
 975                         ext2fs_block_alloc_stats2(fs, blk, +1);
 976                         if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
 977                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
 978                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
 979                                                          blk);
 980                 }
 981
 982                 /*
 983                  * The inode table, if we need to relocate it, is
 984                  * handled specially.  We have to reserve the blocks
 985                  * for both the old and the new inode table, since we
 986                  * can't have the inode table be destroyed during the
 987                  * block relocation phase.
 988                  */
 989                 if (ext2fs_inode_table_loc(fs, i) == ext2fs_inode_table_loc(old_fs, i))
 990                         goto next_group; /* inode table not moved */
 991
 992                 rfs->needed_blocks += fs->inode_blocks_per_group;
 993
 994                 /*
 995                  * Mark the new inode table as in use in the new block
 996                  * allocation bitmap, and move any blocks that might
 997                  * be necessary.
 998                  */
 999                 for (blk = ext2fs_inode_table_loc(fs, i), j=0;
1000                      j < fs->inode_blocks_per_group ; j++, blk++) {
1001                         ext2fs_block_alloc_stats2(fs, blk, +1);
1002                         if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
1003                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
1004                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
1005                                                          blk);
1006                 }
1007
1008                 /*
1009                  * Make sure the old inode table is reserved in the
1010                  * block reservation bitmap.
1011                  */
1012                 for (blk = ext2fs_inode_table_loc(rfs->old_fs, i), j=0;
1013                      j < fs->inode_blocks_per_group ; j++, blk++)
1014                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
1015
1016         next_group:
1017                 group_blk += rfs->new_fs->super->s_blocks_per_group;
1018         }
1019         retval = 0;
1020
1021 errout:
1022         if (meta_bmap)
1023                 ext2fs_free_block_bitmap(meta_bmap);
1024
1025         return retval;
1026 }
1027
1028 /*
1029  * This helper function tries to allocate a new block.  We try to
1030  * avoid hitting the original group descriptor blocks at least at
1031  * first, since we want to make it possible to recover from a badly
1032  * aborted resize operation as much as possible.
1033  *
1034  * In the future, I may further modify this routine to balance out
1035  * where we get the new blocks across the various block groups.
1036  * Ideally we would allocate blocks that corresponded with the block
1037  * group of the containing inode, and keep contiguous blocks
1038  * together.  However, this very difficult to do efficiently, since we
1039  * don't have the necessary information up front.
1040  */
1041
1042 #define AVOID_OLD       1
1043 #define DESPERATION     2
1044
1045 static void init_block_alloc(ext2_resize_t rfs)
1046 {
1047         rfs->alloc_state = AVOID_OLD;
1048         rfs->new_blk = rfs->new_fs->super->s_first_data_block;
1049 #if 0
1050         /* HACK for testing */
1051         if (ext2fs_blocks_count(rfs->new_fs->super) >
1052             ext2fs_blocks_count(rfs->old_fs->super))
1053                 rfs->new_blk = ext2fs_blocks_count(rfs->old_fs->super);
1054 #endif
1055 }
1056
1057 static blk64_t get_new_block(ext2_resize_t rfs)
1058 {
1059         ext2_filsys     fs = rfs->new_fs;
1060
1061         while (1) {
1062                 if (rfs->new_blk >= ext2fs_blocks_count(fs->super)) {
1063                         if (rfs->alloc_state == DESPERATION)
1064                                 return 0;
1065
1066 #ifdef RESIZE2FS_DEBUG
1067                         if (rfs->flags & RESIZE_DEBUG_BMOVE)
1068                                 printf("Going into desperation mode "
1069                                        "for block allocations\n");
1070 #endif
1071                         rfs->alloc_state = DESPERATION;
1072                         rfs->new_blk = fs->super->s_first_data_block;
1073                         continue;
1074                 }
1075                 if (ext2fs_test_block_bitmap2(fs->block_map, rfs->new_blk) ||
1076                     ext2fs_test_block_bitmap2(rfs->reserve_blocks,
1077                                              rfs->new_blk) ||
1078                     ((rfs->alloc_state == AVOID_OLD) &&
1079                      (rfs->new_blk < ext2fs_blocks_count(rfs->old_fs->super)) &&
1080                      ext2fs_test_block_bitmap2(rfs->old_fs->block_map,
1081                                               rfs->new_blk))) {
1082                         rfs->new_blk++;
1083                         continue;
1084                 }
1085                 return rfs->new_blk;
1086         }
1087 }
1088
1089 static errcode_t resize2fs_get_alloc_block(ext2_filsys fs, blk64_t goal,
1090                                            blk64_t *ret)
1091 {
1092         ext2_resize_t rfs = (ext2_resize_t) fs->priv_data;
1093         blk64_t blk;
1094
1095         blk = get_new_block(rfs);
1096         if (!blk)
1097                 return ENOSPC;
1098
1099 #ifdef RESIZE2FS_DEBUG
1100         if (rfs->flags & 0xF)
1101                 printf("get_alloc_block allocating %llu\n", blk);
1102 #endif
1103
1104         ext2fs_mark_block_bitmap2(rfs->old_fs->block_map, blk);
1105         ext2fs_mark_block_bitmap2(rfs->new_fs->block_map, blk);
1106         *ret = (blk64_t) blk;
1107         return 0;
1108 }
1109
1110 static errcode_t block_mover(ext2_resize_t rfs)
1111 {
1112         blk64_t                 blk, old_blk, new_blk;
1113         ext2_filsys             fs = rfs->new_fs;
1114         ext2_filsys             old_fs = rfs->old_fs;
1115         errcode_t               retval;
1116         __u64                   size;
1117         int                     c;
1118         int                     to_move, moved;
1119         ext2_badblocks_list     badblock_list = 0;
1120         int                     bb_modified = 0;
1121
1122         fs->get_alloc_block = resize2fs_get_alloc_block;
1123         old_fs->get_alloc_block = resize2fs_get_alloc_block;
1124
1125         retval = ext2fs_read_bb_inode(old_fs, &badblock_list);
1126         if (retval)
1127                 return retval;
1128
1129         new_blk = fs->super->s_first_data_block;
1130         if (!rfs->itable_buf) {
1131                 retval = ext2fs_get_array(fs->blocksize,
1132                                         fs->inode_blocks_per_group,
1133                                         &rfs->itable_buf);
1134                 if (retval)
1135                         return retval;
1136         }
1137         retval = ext2fs_create_extent_table(&rfs->bmap, 0);
1138         if (retval)
1139                 return retval;
1140
1141         /*
1142          * The first step is to figure out where all of the blocks
1143          * will go.
1144          */
1145         to_move = moved = 0;
1146         init_block_alloc(rfs);
1147         for (blk = old_fs->super->s_first_data_block;
1148              blk < ext2fs_blocks_count(old_fs->super); blk++) {
1149                 if (!ext2fs_test_block_bitmap2(old_fs->block_map, blk))
1150                         continue;
1151                 if (!ext2fs_test_block_bitmap2(rfs->move_blocks, blk))
1152                         continue;
1153                 if (ext2fs_badblocks_list_test(badblock_list, blk)) {
1154                         ext2fs_badblocks_list_del(badblock_list, blk);
1155                         bb_modified++;
1156                         continue;
1157                 }
1158
1159                 new_blk = get_new_block(rfs);
1160                 if (!new_blk) {
1161                         retval = ENOSPC;
1162                         goto errout;
1163                 }
1164                 ext2fs_block_alloc_stats2(fs, new_blk, +1);
1165                 ext2fs_add_extent_entry(rfs->bmap, blk, new_blk);
1166                 to_move++;
1167         }
1168
1169         if (to_move == 0) {
1170                 if (rfs->bmap) {
1171                         ext2fs_free_extent_table(rfs->bmap);
1172                         rfs->bmap = 0;
1173                 }
1174                 retval = 0;
1175                 goto errout;
1176         }
1177
1178         /*
1179          * Step two is to actually move the blocks
1180          */
1181         retval =  ext2fs_iterate_extent(rfs->bmap, 0, 0, 0);
1182         if (retval) goto errout;
1183
1184         if (rfs->progress) {
1185                 retval = (rfs->progress)(rfs, E2_RSZ_BLOCK_RELOC_PASS,
1186                                          0, to_move);
1187                 if (retval)
1188                         goto errout;
1189         }
1190         while (1) {
1191                 retval = ext2fs_iterate_extent(rfs->bmap, &old_blk, &new_blk, &size);
1192                 if (retval) goto errout;
1193                 if (!size)
1194                         break;
1195 #ifdef RESIZE2FS_DEBUG
1196                 if (rfs->flags & RESIZE_DEBUG_BMOVE)
1197                         printf("Moving %llu blocks %llu->%llu\n",
1198                                size, old_blk, new_blk);
1199 #endif
1200                 do {
1201                         c = size;
1202                         if (c > fs->inode_blocks_per_group)
1203                                 c = fs->inode_blocks_per_group;
1204                         retval = io_channel_read_blk64(fs->io, old_blk, c,
1205                                                        rfs->itable_buf);
1206                         if (retval) goto errout;
1207                         retval = io_channel_write_blk64(fs->io, new_blk, c,
1208                                                         rfs->itable_buf);
1209                         if (retval) goto errout;
1210                         size -= c;
1211                         new_blk += c;
1212                         old_blk += c;
1213                         moved += c;
1214                         if (rfs->progress) {
1215                                 io_channel_flush(fs->io);
1216                                 retval = (rfs->progress)(rfs,
1217                                                 E2_RSZ_BLOCK_RELOC_PASS,
1218                                                 moved, to_move);
1219                                 if (retval)
1220                                         goto errout;
1221                         }
1222                 } while (size > 0);
1223                 io_channel_flush(fs->io);
1224         }
1225
1226 errout:
1227         if (badblock_list) {
1228                 if (!retval && bb_modified)
1229                         retval = ext2fs_update_bb_inode(old_fs,
1230                                                         badblock_list);
1231                 ext2fs_badblocks_list_free(badblock_list);
1232         }
1233         return retval;
1234 }
1235
1236
1237 /* --------------------------------------------------------------------
1238  *
1239  * Resize processing, phase 3
1240  *
1241  * --------------------------------------------------------------------
1242  */
1243
1244
1245 struct process_block_struct {
1246         ext2_resize_t           rfs;
1247         ext2_ino_t              ino;
1248         struct ext2_inode *     inode;
1249         errcode_t               error;
1250         int                     is_dir;
1251         int                     changed;
1252 };
1253
1254 static int process_block(ext2_filsys fs, blk64_t        *block_nr,
1255                          e2_blkcnt_t blockcnt,
1256                          blk64_t ref_block EXT2FS_ATTR((unused)),
1257                          int ref_offset EXT2FS_ATTR((unused)), void *priv_data)
1258 {
1259         struct process_block_struct *pb;
1260         errcode_t       retval;
1261         blk64_t         block, new_block;
1262         int             ret = 0;
1263
1264         pb = (struct process_block_struct *) priv_data;
1265         block = *block_nr;
1266         if (pb->rfs->bmap) {
1267                 new_block = ext2fs_extent_translate(pb->rfs->bmap, block);
1268                 if (new_block) {
1269                         *block_nr = new_block;
1270                         ret |= BLOCK_CHANGED;
1271                         pb->changed = 1;
1272 #ifdef RESIZE2FS_DEBUG
1273                         if (pb->rfs->flags & RESIZE_DEBUG_BMOVE)
1274                                 printf("ino=%u, blockcnt=%lld, %llu->%llu\n",
1275                                        pb->ino, blockcnt, block, new_block);
1276 #endif
1277                         block = new_block;
1278                 }
1279         }
1280         if (pb->is_dir) {
1281                 retval = ext2fs_add_dir_block2(fs->dblist, pb->ino,
1282                                                block, (int) blockcnt);
1283                 if (retval) {
1284                         pb->error = retval;
1285                         ret |= BLOCK_ABORT;
1286                 }
1287         }
1288         return ret;
1289 }
1290
1291 /*
1292  * Progress callback
1293  */
1294 static errcode_t progress_callback(ext2_filsys fs,
1295                                    ext2_inode_scan scan EXT2FS_ATTR((unused)),
1296                                    dgrp_t group, void * priv_data)
1297 {
1298         ext2_resize_t rfs = (ext2_resize_t) priv_data;
1299         errcode_t               retval;
1300
1301         /*
1302          * This check is to protect against old ext2 libraries.  It
1303          * shouldn't be needed against new libraries.
1304          */
1305         if ((group+1) == 0)
1306                 return 0;
1307
1308         if (rfs->progress) {
1309                 io_channel_flush(fs->io);
1310                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
1311                                          group+1, fs->group_desc_count);
1312                 if (retval)
1313                         return retval;
1314         }
1315
1316         return 0;
1317 }
1318
1319 static errcode_t inode_scan_and_fix(ext2_resize_t rfs)
1320 {
1321         struct process_block_struct     pb;
1322         ext2_ino_t              ino, new_inode;
1323         struct ext2_inode       *inode = NULL;
1324         ext2_inode_scan         scan = NULL;
1325         errcode_t               retval;
1326         char                    *block_buf = 0;
1327         ext2_ino_t              start_to_move;
1328         blk64_t                 orig_size;
1329         blk64_t                 new_block;
1330         int                     inode_size;
1331
1332         if ((rfs->old_fs->group_desc_count <=
1333              rfs->new_fs->group_desc_count) &&
1334             !rfs->bmap)
1335                 return 0;
1336
1337         /*
1338          * Save the original size of the old filesystem, and
1339          * temporarily set the size to be the new size if the new size
1340          * is larger.  We need to do this to avoid catching an error
1341          * by the block iterator routines
1342          */
1343         orig_size = ext2fs_blocks_count(rfs->old_fs->super);
1344         if (orig_size < ext2fs_blocks_count(rfs->new_fs->super))
1345                 ext2fs_blocks_count_set(rfs->old_fs->super,
1346                                 ext2fs_blocks_count(rfs->new_fs->super));
1347
1348         retval = ext2fs_open_inode_scan(rfs->old_fs, 0, &scan);
1349         if (retval) goto errout;
1350
1351         retval = ext2fs_init_dblist(rfs->old_fs, 0);
1352         if (retval) goto errout;
1353         retval = ext2fs_get_array(rfs->old_fs->blocksize, 3, &block_buf);
1354         if (retval) goto errout;
1355
1356         start_to_move = (rfs->new_fs->group_desc_count *
1357                          rfs->new_fs->super->s_inodes_per_group);
1358
1359         if (rfs->progress) {
1360                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
1361                                          0, rfs->old_fs->group_desc_count);
1362                 if (retval)
1363                         goto errout;
1364         }
1365         ext2fs_set_inode_callback(scan, progress_callback, (void *) rfs);
1366         pb.rfs = rfs;
1367         pb.inode = inode;
1368         pb.error = 0;
1369         new_inode = EXT2_FIRST_INODE(rfs->new_fs->super);
1370         inode_size = EXT2_INODE_SIZE(rfs->new_fs->super);
1371         inode = malloc(inode_size);
1372         if (!inode) {
1373                 retval = ENOMEM;
1374                 goto errout;
1375         }
1376         /*
1377          * First, copy all of the inodes that need to be moved
1378          * elsewhere in the inode table
1379          */
1380         while (1) {
1381                 retval = ext2fs_get_next_inode_full(scan, &ino, inode, inode_size);
1382                 if (retval) goto errout;
1383                 if (!ino)
1384                         break;
1385
1386                 if (inode->i_links_count == 0 && ino != EXT2_RESIZE_INO)
1387                         continue; /* inode not in use */
1388
1389                 pb.is_dir = LINUX_S_ISDIR(inode->i_mode);
1390                 pb.changed = 0;
1391
1392                 if (ext2fs_file_acl_block(rfs->old_fs, inode) && rfs->bmap) {
1393                         new_block = ext2fs_extent_translate(rfs->bmap,
1394                                 ext2fs_file_acl_block(rfs->old_fs, inode));
1395                         if (new_block) {
1396                                 ext2fs_file_acl_block_set(rfs->old_fs, inode,
1397                                                           new_block);
1398                                 retval = ext2fs_write_inode_full(rfs->old_fs,
1399                                                             ino, inode, inode_size);
1400                                 if (retval) goto errout;
1401                         }
1402                 }
1403
1404                 if (ext2fs_inode_has_valid_blocks2(rfs->old_fs, inode) &&
1405                     (rfs->bmap || pb.is_dir)) {
1406                         pb.ino = ino;
1407                         retval = ext2fs_block_iterate3(rfs->old_fs,
1408                                                        ino, 0, block_buf,
1409                                                        process_block, &pb);
1410                         if (retval)
1411                                 goto errout;
1412                         if (pb.error) {
1413                                 retval = pb.error;
1414                                 goto errout;
1415                         }
1416                 }
1417
1418                 if (ino <= start_to_move)
1419                         continue; /* Don't need to move it. */
1420
1421                 /*
1422                  * Find a new inode
1423                  */
1424                 retval = ext2fs_new_inode(rfs->new_fs, 0, 0, 0, &new_inode);
1425                 if (retval)
1426                         goto errout;
1427
1428                 ext2fs_inode_alloc_stats2(rfs->new_fs, new_inode, +1,
1429                                           pb.is_dir);
1430                 if (pb.changed) {
1431                         /* Get the new version of the inode */
1432                         retval = ext2fs_read_inode_full(rfs->old_fs, ino,
1433                                                 inode, inode_size);
1434                         if (retval) goto errout;
1435                 }
1436                 inode->i_ctime = time(0);
1437                 retval = ext2fs_write_inode_full(rfs->old_fs, new_inode,
1438                                                 inode, inode_size);
1439                 if (retval) goto errout;
1440
1441 #ifdef RESIZE2FS_DEBUG
1442                 if (rfs->flags & RESIZE_DEBUG_INODEMAP)
1443                         printf("Inode moved %u->%u\n", ino, new_inode);
1444 #endif
1445                 if (!rfs->imap) {
1446                         retval = ext2fs_create_extent_table(&rfs->imap, 0);
1447                         if (retval)
1448                                 goto errout;
1449                 }
1450                 ext2fs_add_extent_entry(rfs->imap, ino, new_inode);
1451         }
1452         io_channel_flush(rfs->old_fs->io);
1453
1454 errout:
1455         ext2fs_blocks_count_set(rfs->old_fs->super, orig_size);
1456         if (rfs->bmap) {
1457                 ext2fs_free_extent_table(rfs->bmap);
1458                 rfs->bmap = 0;
1459         }
1460         if (scan)
1461                 ext2fs_close_inode_scan(scan);
1462         if (block_buf)
1463                 ext2fs_free_mem(&block_buf);
1464         free(inode);
1465         return retval;
1466 }
1467
1468 /* --------------------------------------------------------------------
1469  *
1470  * Resize processing, phase 4.
1471  *
1472  * --------------------------------------------------------------------
1473  */
1474
1475 struct istruct {
1476         ext2_resize_t rfs;
1477         errcode_t       err;
1478         unsigned int    max_dirs;
1479         unsigned int    num;
1480 };
1481
1482 static int check_and_change_inodes(ext2_ino_t dir,
1483                                    int entry EXT2FS_ATTR((unused)),
1484                                    struct ext2_dir_entry *dirent, int offset,
1485                                    int  blocksize EXT2FS_ATTR((unused)),
1486                                    char *buf EXT2FS_ATTR((unused)),
1487                                    void *priv_data)
1488 {
1489         struct istruct *is = (struct istruct *) priv_data;
1490         struct ext2_inode       inode;
1491         ext2_ino_t              new_inode;
1492         errcode_t               retval;
1493
1494         if (is->rfs->progress && offset == 0) {
1495                 io_channel_flush(is->rfs->old_fs->io);
1496                 is->err = (is->rfs->progress)(is->rfs,
1497                                               E2_RSZ_INODE_REF_UPD_PASS,
1498                                               ++is->num, is->max_dirs);
1499                 if (is->err)
1500                         return DIRENT_ABORT;
1501         }
1502
1503         if (!dirent->inode)
1504                 return 0;
1505
1506         new_inode = ext2fs_extent_translate(is->rfs->imap, dirent->inode);
1507
1508         if (!new_inode)
1509                 return 0;
1510 #ifdef RESIZE2FS_DEBUG
1511         if (is->rfs->flags & RESIZE_DEBUG_INODEMAP)
1512                 printf("Inode translate (dir=%u, name=%.*s, %u->%u)\n",
1513                        dir, dirent->name_len&0xFF, dirent->name,
1514                        dirent->inode, new_inode);
1515 #endif
1516
1517         dirent->inode = new_inode;
1518
1519         /* Update the directory mtime and ctime */
1520         retval = ext2fs_read_inode(is->rfs->old_fs, dir, &inode);
1521         if (retval == 0) {
1522                 inode.i_mtime = inode.i_ctime = time(0);
1523                 is->err = ext2fs_write_inode(is->rfs->old_fs, dir, &inode);
1524                 if (is->err)
1525                         return DIRENT_ABORT;
1526         }
1527
1528         return DIRENT_CHANGED;
1529 }
1530
1531 static errcode_t inode_ref_fix(ext2_resize_t rfs)
1532 {
1533         errcode_t               retval;
1534         struct istruct          is;
1535
1536         if (!rfs->imap)
1537                 return 0;
1538
1539         /*
1540          * Now, we iterate over all of the directories to update the
1541          * inode references
1542          */
1543         is.num = 0;
1544         is.max_dirs = ext2fs_dblist_count2(rfs->old_fs->dblist);
1545         is.rfs = rfs;
1546         is.err = 0;
1547
1548         if (rfs->progress) {
1549                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS,
1550                                          0, is.max_dirs);
1551                 if (retval)
1552                         goto errout;
1553         }
1554
1555         retval = ext2fs_dblist_dir_iterate(rfs->old_fs->dblist,
1556                                            DIRENT_FLAG_INCLUDE_EMPTY, 0,
1557                                            check_and_change_inodes, &is);
1558         if (retval)
1559                 goto errout;
1560         if (is.err) {
1561                 retval = is.err;
1562                 goto errout;
1563         }
1564
1565         if (rfs->progress && (is.num < is.max_dirs))
1566                 (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS,
1567                                 is.max_dirs, is.max_dirs);
1568
1569 errout:
1570         ext2fs_free_extent_table(rfs->imap);
1571         rfs->imap = 0;
1572         return retval;
1573 }
1574
1575
1576 /* --------------------------------------------------------------------
1577  *
1578  * Resize processing, phase 5.
1579  *
1580  * In this phase we actually move the inode table around, and then
1581  * update the summary statistics.  This is scary, since aborting here
1582  * will potentially scramble the filesystem.  (We are moving the
1583  * inode tables around in place, and so the potential for lost data,
1584  * or at the very least scrambling the mapping between filenames and
1585  * inode numbers is very high in case of a power failure here.)
1586  * --------------------------------------------------------------------
1587  */
1588
1589
1590 /*
1591  * A very scary routine --- this one moves the inode table around!!!
1592  *
1593  * After this you have to use the rfs->new_fs file handle to read and
1594  * write inodes.
1595  */
1596 static errcode_t move_itables(ext2_resize_t rfs)
1597 {
1598         int             n, num, size;
1599         long long       diff;
1600         dgrp_t          i, max_groups;
1601         ext2_filsys     fs = rfs->new_fs;
1602         char            *cp;
1603         blk64_t         old_blk, new_blk, blk;
1604         errcode_t       retval;
1605         int             j, to_move, moved;
1606
1607         max_groups = fs->group_desc_count;
1608         if (max_groups > rfs->old_fs->group_desc_count)
1609                 max_groups = rfs->old_fs->group_desc_count;
1610
1611         size = fs->blocksize * fs->inode_blocks_per_group;
1612         if (!rfs->itable_buf) {
1613                 retval = ext2fs_get_mem(size, &rfs->itable_buf);
1614                 if (retval)
1615                         return retval;
1616         }
1617
1618         /*
1619          * Figure out how many inode tables we need to move
1620          */
1621         to_move = moved = 0;
1622         for (i=0; i < max_groups; i++)
1623                 if (ext2fs_inode_table_loc(rfs->old_fs, i) !=
1624                     ext2fs_inode_table_loc(fs, i))
1625                         to_move++;
1626
1627         if (to_move == 0)
1628                 return 0;
1629
1630         if (rfs->progress) {
1631                 retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
1632                                        0, to_move);
1633                 if (retval)
1634                         goto errout;
1635         }
1636
1637         rfs->old_fs->flags |= EXT2_FLAG_MASTER_SB_ONLY;
1638
1639         for (i=0; i < max_groups; i++) {
1640                 old_blk = ext2fs_inode_table_loc(rfs->old_fs, i);
1641                 new_blk = ext2fs_inode_table_loc(fs, i);
1642                 diff = new_blk - old_blk;
1643
1644 #ifdef RESIZE2FS_DEBUG
1645                 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1646                         printf("Itable move group %d block %llu->%llu (diff %lld)\n",
1647                                i, old_blk, new_blk, diff);
1648 #endif
1649
1650                 if (!diff)
1651                         continue;
1652
1653                 retval = io_channel_read_blk64(fs->io, old_blk,
1654                                                fs->inode_blocks_per_group,
1655                                                rfs->itable_buf);
1656                 if (retval)
1657                         goto errout;
1658                 /*
1659                  * The end of the inode table segment often contains
1660                  * all zeros, and we're often only moving the inode
1661                  * table down a block or two.  If so, we can optimize
1662                  * things by not rewriting blocks that we know to be zero
1663                  * already.
1664                  */
1665                 for (cp = rfs->itable_buf+size-1, n=0; n < size; n++, cp--)
1666                         if (*cp)
1667                                 break;
1668                 n = n >> EXT2_BLOCK_SIZE_BITS(fs->super);
1669 #ifdef RESIZE2FS_DEBUG
1670                 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1671                         printf("%d blocks of zeros...\n", n);
1672 #endif
1673                 num = fs->inode_blocks_per_group;
1674                 if (n > diff)
1675                         num -= n;
1676
1677                 retval = io_channel_write_blk64(fs->io, new_blk,
1678                                                 num, rfs->itable_buf);
1679                 if (retval) {
1680                         io_channel_write_blk64(fs->io, old_blk,
1681                                                num, rfs->itable_buf);
1682                         goto errout;
1683                 }
1684                 if (n > diff) {
1685                         retval = io_channel_write_blk64(fs->io,
1686                               old_blk + fs->inode_blocks_per_group,
1687                               diff, (rfs->itable_buf +
1688                                      (fs->inode_blocks_per_group - diff) *
1689                                      fs->blocksize));
1690                         if (retval)
1691                                 goto errout;
1692                 }
1693
1694                 for (blk = ext2fs_inode_table_loc(rfs->old_fs, i), j=0;
1695                      j < fs->inode_blocks_per_group ; j++, blk++)
1696                         ext2fs_block_alloc_stats2(fs, blk, -1);
1697
1698                 ext2fs_inode_table_loc_set(rfs->old_fs, i, new_blk);
1699                 ext2fs_group_desc_csum_set(rfs->old_fs, i);
1700                 ext2fs_mark_super_dirty(rfs->old_fs);
1701                 ext2fs_flush(rfs->old_fs);
1702
1703                 if (rfs->progress) {
1704                         retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
1705                                                ++moved, to_move);
1706                         if (retval)
1707                                 goto errout;
1708                 }
1709         }
1710         mark_table_blocks(fs, fs->block_map);
1711         ext2fs_flush(fs);
1712 #ifdef RESIZE2FS_DEBUG
1713         if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1714                 printf("Inode table move finished.\n");
1715 #endif
1716         return 0;
1717
1718 errout:
1719         return retval;
1720 }
1721
1722 /*
1723  * Fix the resize inode
1724  */
1725 static errcode_t fix_resize_inode(ext2_filsys fs)
1726 {
1727         struct ext2_inode       inode;
1728         errcode_t               retval;
1729         char *                  block_buf;
1730
1731         if (!(fs->super->s_feature_compat &
1732               EXT2_FEATURE_COMPAT_RESIZE_INODE))
1733                 return 0;
1734
1735         retval = ext2fs_get_mem(fs->blocksize, &block_buf);
1736         if (retval) goto errout;
1737
1738         retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode);
1739         if (retval) goto errout;
1740
1741         ext2fs_iblk_set(fs, &inode, 1);
1742
1743         retval = ext2fs_write_inode(fs, EXT2_RESIZE_INO, &inode);
1744         if (retval) goto errout;
1745
1746         if (!inode.i_block[EXT2_DIND_BLOCK]) {
1747                 /*
1748                  * Avoid zeroing out block #0; that's rude.  This
1749                  * should never happen anyway since the filesystem
1750                  * should be fsck'ed and we assume it is consistent.
1751                  */
1752                 fprintf(stderr,
1753                         _("Should never happen: resize inode corrupt!\n"));
1754                 exit(1);
1755         }
1756
1757         memset(block_buf, 0, fs->blocksize);
1758
1759         retval = io_channel_write_blk64(fs->io, inode.i_block[EXT2_DIND_BLOCK],
1760                                         1, block_buf);
1761         if (retval) goto errout;
1762
1763         retval = ext2fs_create_resize_inode(fs);
1764         if (retval)
1765                 goto errout;
1766
1767 errout:
1768         if (block_buf)
1769                 ext2fs_free_mem(&block_buf);
1770         return retval;
1771 }
1772
1773 /*
1774  * Finally, recalculate the summary information
1775  */
1776 static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs)
1777 {
1778         blk64_t         blk;
1779         ext2_ino_t      ino;
1780         unsigned int    group = 0;
1781         unsigned int    count = 0;
1782         int             total_free = 0;
1783         int             group_free = 0;
1784         int             uninit = 0;
1785         blk64_t         super_blk, old_desc_blk, new_desc_blk;
1786         int             old_desc_blocks;
1787
1788         /*
1789          * First calculate the block statistics
1790          */
1791         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT);
1792         ext2fs_super_and_bgd_loc2(fs, group, &super_blk, &old_desc_blk,
1793                                   &new_desc_blk, 0);
1794         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
1795                 old_desc_blocks = fs->super->s_first_meta_bg;
1796         else
1797                 old_desc_blocks = fs->desc_blocks +
1798                         fs->super->s_reserved_gdt_blocks;
1799         for (blk = fs->super->s_first_data_block;
1800              blk < ext2fs_blocks_count(fs->super); blk++) {
1801                 if ((uninit &&
1802                      !((blk == super_blk) ||
1803                        ((old_desc_blk && old_desc_blocks &&
1804                          (blk >= old_desc_blk) &&
1805                          (blk < old_desc_blk + old_desc_blocks))) ||
1806                        ((new_desc_blk && (blk == new_desc_blk))) ||
1807                        (blk == ext2fs_block_bitmap_loc(fs, group)) ||
1808                        (blk == ext2fs_inode_bitmap_loc(fs, group)) ||
1809                        ((blk >= ext2fs_inode_table_loc(fs, group) &&
1810                          (blk < ext2fs_inode_table_loc(fs, group)
1811                           + fs->inode_blocks_per_group))))) ||
1812                     (!ext2fs_fast_test_block_bitmap2(fs->block_map, blk))) {
1813                         group_free++;
1814                         total_free++;
1815                 }
1816                 count++;
1817                 if ((count == fs->super->s_blocks_per_group) ||
1818                     (blk == ext2fs_blocks_count(fs->super)-1)) {
1819                         ext2fs_bg_free_blocks_count_set(fs, group, group_free);
1820                         ext2fs_group_desc_csum_set(fs, group);
1821                         group++;
1822                         if (group >= fs->group_desc_count)
1823                                 break;
1824                         count = 0;
1825                         group_free = 0;
1826                         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT);
1827                         ext2fs_super_and_bgd_loc2(fs, group, &super_blk,
1828                                                   &old_desc_blk,
1829                                                   &new_desc_blk, 0);
1830                         if (fs->super->s_feature_incompat &
1831                             EXT2_FEATURE_INCOMPAT_META_BG)
1832                                 old_desc_blocks = fs->super->s_first_meta_bg;
1833                         else
1834                                 old_desc_blocks = fs->desc_blocks +
1835                                         fs->super->s_reserved_gdt_blocks;
1836                 }
1837         }
1838         ext2fs_free_blocks_count_set(fs->super, total_free);
1839
1840         /*
1841          * Next, calculate the inode statistics
1842          */
1843         group_free = 0;
1844         total_free = 0;
1845         count = 0;
1846         group = 0;
1847
1848         /* Protect loop from wrap-around if s_inodes_count maxed */
1849         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT);
1850         for (ino = 1; ino <= fs->super->s_inodes_count && ino > 0; ino++) {
1851                 if (uninit ||
1852                     !ext2fs_fast_test_inode_bitmap2(fs->inode_map, ino)) {
1853                         group_free++;
1854                         total_free++;
1855                 }
1856                 count++;
1857                 if ((count == fs->super->s_inodes_per_group) ||
1858                     (ino == fs->super->s_inodes_count)) {
1859                         ext2fs_bg_free_inodes_count_set(fs, group, group_free);
1860                         ext2fs_group_desc_csum_set(fs, group);
1861                         group++;
1862                         if (group >= fs->group_desc_count)
1863                                 break;
1864                         count = 0;
1865                         group_free = 0;
1866                         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT);
1867                 }
1868         }
1869         fs->super->s_free_inodes_count = total_free;
1870         ext2fs_mark_super_dirty(fs);
1871         return 0;
1872 }
1873
1874 /*
1875  *  Journal may have been relocated; update the backup journal blocks
1876  *  in the superblock.
1877  */
1878 static errcode_t fix_sb_journal_backup(ext2_filsys fs)
1879 {
1880         errcode_t         retval;
1881         struct ext2_inode inode;
1882
1883         if (!(fs->super->s_feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1884                 return 0;
1885
1886         /* External journal? Nothing to do. */
1887         if (fs->super->s_journal_dev && !fs->super->s_journal_inum)
1888                 return 0;
1889
1890         retval = ext2fs_read_inode(fs, fs->super->s_journal_inum, &inode);
1891         if (retval)
1892                 return retval;
1893         memcpy(fs->super->s_jnl_blocks, inode.i_block, EXT2_N_BLOCKS*4);
1894         fs->super->s_jnl_blocks[15] = inode.i_size_high;
1895         fs->super->s_jnl_blocks[16] = inode.i_size;
1896         fs->super->s_jnl_backup_type = EXT3_JNL_BACKUP_BLOCKS;
1897         ext2fs_mark_super_dirty(fs);
1898         return 0;
1899 }
1900
1901 static int calc_group_overhead(ext2_filsys fs, blk64_t grp,
1902                                int old_desc_blocks)
1903 {
1904         blk64_t super_blk, old_desc_blk, new_desc_blk;
1905         int overhead;
1906
1907         /* inode table blocks plus allocation bitmaps */
1908         overhead = fs->inode_blocks_per_group + 2;
1909
1910         ext2fs_super_and_bgd_loc2(fs, grp, &super_blk,
1911                                   &old_desc_blk, &new_desc_blk, 0);
1912         if ((grp == 0) || super_blk)
1913                 overhead++;
1914         if (old_desc_blk)
1915                 overhead += old_desc_blocks;
1916         else if (new_desc_blk)
1917                 overhead++;
1918         return overhead;
1919 }
1920
1921
1922 /*
1923  * calcluate the minimum number of blocks the given fs can be resized to
1924  */
1925 blk64_t calculate_minimum_resize_size(ext2_filsys fs)
1926 {
1927         ext2_ino_t inode_count;
1928         blk64_t blks_needed, groups, data_blocks;
1929         blk64_t grp, data_needed, last_start;
1930         blk64_t overhead = 0;
1931         int num_of_superblocks = 0;
1932         blk64_t super_overhead = 0;
1933         int old_desc_blocks;
1934         int extra_groups = 0;
1935         int flexbg_size = 1 << fs->super->s_log_groups_per_flex;
1936
1937         /*
1938          * first figure out how many group descriptors we need to
1939          * handle the number of inodes we have
1940          */
1941         inode_count = fs->super->s_inodes_count -
1942                 fs->super->s_free_inodes_count;
1943         blks_needed = ext2fs_div_ceil(inode_count,
1944                                       fs->super->s_inodes_per_group) *
1945                 EXT2_BLOCKS_PER_GROUP(fs->super);
1946         groups = ext2fs_div64_ceil(blks_needed,
1947                                    EXT2_BLOCKS_PER_GROUP(fs->super));
1948
1949         /*
1950          * number of old-style block group descriptor blocks
1951          */
1952         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
1953                 old_desc_blocks = fs->super->s_first_meta_bg;
1954         else
1955                 old_desc_blocks = fs->desc_blocks +
1956                         fs->super->s_reserved_gdt_blocks;
1957
1958         /* calculate how many blocks are needed for data */
1959         data_needed = ext2fs_blocks_count(fs->super) -
1960                 ext2fs_free_blocks_count(fs->super);
1961
1962         for (grp = 0; grp < fs->group_desc_count; grp++)
1963                 data_needed -= calc_group_overhead(fs, grp, old_desc_blocks);
1964
1965         /*
1966          * For ext4 we need to allow for up to a flex_bg worth of
1967          * inode tables of slack space so the resize operation can be
1968          * guaranteed to finish.
1969          */
1970         if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_FLEX_BG) {
1971                 extra_groups = flexbg_size - (groups & (flexbg_size - 1));
1972                 data_needed += fs->inode_blocks_per_group * extra_groups;
1973                 extra_groups = groups % flexbg_size;
1974         }
1975
1976         /*
1977          * figure out how many data blocks we have given the number of groups
1978          * we need for our inodes
1979          */
1980         data_blocks = groups * EXT2_BLOCKS_PER_GROUP(fs->super);
1981         last_start = 0;
1982         for (grp = 0; grp < groups; grp++) {
1983                 overhead = calc_group_overhead(fs, grp, old_desc_blocks);
1984
1985                 /*
1986                  * we want to keep track of how much data we can store in
1987                  * the groups leading up to the last group so we can determine
1988                  * how big the last group needs to be
1989                  */
1990                 if (grp != (groups - 1))
1991                         last_start += EXT2_BLOCKS_PER_GROUP(fs->super) -
1992                                 overhead;
1993
1994                 data_blocks -= overhead;
1995         }
1996
1997         /*
1998          * if we need more group descriptors in order to accomodate our data
1999          * then we need to add them here
2000          */
2001         while (data_needed > data_blocks) {
2002                 blk64_t remainder = data_needed - data_blocks;
2003                 blk64_t extra_grps;
2004
2005                 /* figure out how many more groups we need for the data */
2006                 extra_grps = ext2fs_div64_ceil(remainder,
2007                                                EXT2_BLOCKS_PER_GROUP(fs->super));
2008
2009                 data_blocks += extra_grps * EXT2_BLOCKS_PER_GROUP(fs->super);
2010
2011                 /* ok we have to account for the last group */
2012                 overhead = calc_group_overhead(fs, groups-1, old_desc_blocks);
2013                 last_start += EXT2_BLOCKS_PER_GROUP(fs->super) - overhead;
2014
2015                 for (grp = groups; grp < groups+extra_grps; grp++) {
2016                         overhead = calc_group_overhead(fs, grp,
2017                                                        old_desc_blocks);
2018
2019                         /*
2020                          * again, we need to see how much data we cram into
2021                          * all of the groups leading up to the last group
2022                          */
2023                         if (grp != (groups + extra_grps - 1))
2024                                 last_start += EXT2_BLOCKS_PER_GROUP(fs->super)
2025                                         - overhead;
2026
2027                         data_blocks -= overhead;
2028                 }
2029
2030                 groups += extra_grps;
2031                 extra_groups += extra_grps;
2032                 if (fs->super->s_feature_incompat
2033                         & EXT4_FEATURE_INCOMPAT_FLEX_BG
2034                     && extra_groups > flexbg_size) {
2035                         /*
2036                          * For ext4 we need to allow for up to a flex_bg worth
2037                          * of inode tables of slack space so the resize
2038                          * operation can be guaranteed to finish.
2039                          */
2040                         extra_groups = flexbg_size -
2041                                                 (groups & (flexbg_size - 1));
2042                         data_needed += (fs->inode_blocks_per_group *
2043                                         extra_groups);
2044                         extra_groups = groups % flexbg_size;
2045                 }
2046         }
2047
2048         /* now for the fun voodoo */
2049         overhead = calc_group_overhead(fs, groups-1, old_desc_blocks);
2050
2051         /*
2052          * if this is the case then the last group is going to have data in it
2053          * so we need to adjust the size of the last group accordingly
2054          */
2055         if (last_start < data_needed) {
2056                 blk64_t remainder = data_needed - last_start;
2057
2058                 /*
2059                  * 50 is a magic number that mkfs/resize uses to see if its
2060                  * even worth making/resizing the fs.  basically you need to
2061                  * have at least 50 blocks in addition to the blocks needed
2062                  * for the metadata in the last group
2063                  */
2064                 if (remainder > 50)
2065                         overhead += remainder;
2066                 else
2067                         overhead += 50;
2068         } else
2069                 overhead += 50;
2070
2071         overhead += fs->super->s_first_data_block;
2072
2073         /*
2074          * since our last group doesn't have to be BLOCKS_PER_GROUP large, we
2075          * only do groups-1, and then add the number of blocks needed to
2076          * handle the group descriptor metadata+data that we need
2077          */
2078         blks_needed = (groups-1) * EXT2_BLOCKS_PER_GROUP(fs->super);
2079         blks_needed += overhead;
2080
2081         /*
2082          * If at this point we've already added up more "needed" than
2083          * the current size, just return current size as minimum.
2084          */
2085         if (blks_needed >= ext2fs_blocks_count(fs->super))
2086                 return ext2fs_blocks_count(fs->super);
2087         /*
2088          * We need to reserve a few extra blocks if extents are
2089          * enabled, in case we need to grow the extent tree.  The more
2090          * we shrink the file system, the more space we need.
2091          */
2092         if (fs->super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_EXTENTS)
2093                 blks_needed += (ext2fs_blocks_count(fs->super) -
2094                                 blks_needed)/500;
2095
2096         return blks_needed;
2097 }