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 "resize2fs.h"
  37 #include <time.h>
  38
  39 #ifdef __linux__                        /* Kludge for debugging */
  40 #define RESIZE2FS_DEBUG
  41 #endif
  42
  43 static void fix_uninit_block_bitmaps(ext2_filsys fs);
  44 static errcode_t adjust_superblock(ext2_resize_t rfs, blk_t new_size);
  45 static errcode_t blocks_to_move(ext2_resize_t rfs);
  46 static errcode_t block_mover(ext2_resize_t rfs);
  47 static errcode_t inode_scan_and_fix(ext2_resize_t rfs);
  48 static errcode_t inode_ref_fix(ext2_resize_t rfs);
  49 static errcode_t move_itables(ext2_resize_t rfs);
  50 static errcode_t fix_resize_inode(ext2_filsys fs);
  51 static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs);
  52 static errcode_t fix_sb_journal_backup(ext2_filsys fs);
  53
  54 /*
  55  * Some helper CPP macros
  56  */
  57 #define IS_BLOCK_BM(fs, i, blk) ((blk) == ext2fs_block_bitmap_loc((fs),(i)))
  58 #define IS_INODE_BM(fs, i, blk) ((blk) == ext2fs_inode_bitmap_loc((fs),(i)))
  59
  60 #define IS_INODE_TB(fs, i, blk) (((blk) >= ext2fs_inode_table_loc((fs), (i))) && \
  61                                  ((blk) < (ext2fs_inode_table_loc((fs), (i)) + \
  62                                            (fs)->inode_blocks_per_group)))
  63
  64 #define META_OVERHEAD(fs) (2 + (fs)->inode_blocks_per_group)
  65 #define SUPER_OVERHEAD(fs) (1 + (fs)->desc_blocks +\
  66                             (fs)->super->s_reserved_gdt_blocks)
  67
  68 /*
  69  * This is the top-level routine which does the dirty deed....
  70  */
  71 errcode_t resize_fs(ext2_filsys fs, blk_t *new_size, int flags,
  72             errcode_t (*progress)(ext2_resize_t rfs, int pass,
  73                                           unsigned long cur,
  74                                           unsigned long max_val))
  75 {
  76         ext2_resize_t   rfs;
  77         errcode_t       retval;
  78
  79         retval = ext2fs_read_bitmaps(fs);
  80         if (retval)
  81                 return retval;
  82
  83         fs->super->s_state |= EXT2_ERROR_FS;
  84         ext2fs_mark_super_dirty(fs);
  85         ext2fs_flush(fs);
  86
  87         /*
  88          * Create the data structure
  89          */
  90         retval = ext2fs_get_mem(sizeof(struct ext2_resize_struct), &rfs);
  91         if (retval)
  92                 return retval;
  93         memset(rfs, 0, sizeof(struct ext2_resize_struct));
  94
  95         fix_uninit_block_bitmaps(fs);
  96         fs->priv_data = rfs;
  97         rfs->old_fs = fs;
  98         rfs->flags = flags;
  99         rfs->itable_buf  = 0;
 100         rfs->progress = progress;
 101         retval = ext2fs_dup_handle(fs, &rfs->new_fs);
 102         if (retval)
 103                 goto errout;
 104
 105         retval = adjust_superblock(rfs, *new_size);
 106         if (retval)
 107                 goto errout;
 108
 109         fix_uninit_block_bitmaps(rfs->new_fs);
 110         /* Clear the block bitmap uninit flag for the last block group */
 111         ext2fs_bg_flags_clear(rfs->new_fs, rfs->new_fs->group_desc_count - 1,
 112                              EXT2_BG_BLOCK_UNINIT);
 113
 114         *new_size = ext2fs_blocks_count(rfs->new_fs->super);
 115
 116         retval = blocks_to_move(rfs);
 117         if (retval)
 118                 goto errout;
 119
 120 #ifdef RESIZE2FS_DEBUG
 121         if (rfs->flags & RESIZE_DEBUG_BMOVE)
 122                 printf("Number of free blocks: %llu/%llu, Needed: %d\n",
 123                        ext2fs_free_blocks_count(rfs->old_fs->super),
 124                        ext2fs_free_blocks_count(rfs->new_fs->super),
 125                        rfs->needed_blocks);
 126 #endif
 127
 128         retval = block_mover(rfs);
 129         if (retval)
 130                 goto errout;
 131
 132         retval = inode_scan_and_fix(rfs);
 133         if (retval)
 134                 goto errout;
 135
 136         retval = inode_ref_fix(rfs);
 137         if (retval)
 138                 goto errout;
 139
 140         retval = move_itables(rfs);
 141         if (retval)
 142                 goto errout;
 143
 144         retval = ext2fs_calculate_summary_stats(rfs->new_fs);
 145         if (retval)
 146                 goto errout;
 147
 148         retval = fix_resize_inode(rfs->new_fs);
 149         if (retval)
 150                 goto errout;
 151
 152         retval = fix_sb_journal_backup(rfs->new_fs);
 153         if (retval)
 154                 goto errout;
 155
 156         rfs->new_fs->super->s_state &= ~EXT2_ERROR_FS;
 157         rfs->new_fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
 158         retval = ext2fs_close(rfs->new_fs);
 159         if (retval)
 160                 goto errout;
 161
 162         rfs->flags = flags;
 163
 164         ext2fs_free(rfs->old_fs);
 165         if (rfs->itable_buf)
 166                 ext2fs_free_mem(&rfs->itable_buf);
 167         if (rfs->reserve_blocks)
 168                 ext2fs_free_block_bitmap(rfs->reserve_blocks);
 169         if (rfs->move_blocks)
 170                 ext2fs_free_block_bitmap(rfs->move_blocks);
 171         ext2fs_free_mem(&rfs);
 172
 173         return 0;
 174
 175 errout:
 176         if (rfs->new_fs)
 177                 ext2fs_free(rfs->new_fs);
 178         if (rfs->itable_buf)
 179                 ext2fs_free_mem(&rfs->itable_buf);
 180         ext2fs_free_mem(&rfs);
 181         return retval;
 182 }
 183
 184 /*
 185  * Clean up the bitmaps for unitialized bitmaps
 186  */
 187 static void fix_uninit_block_bitmaps(ext2_filsys fs)
 188 {
 189         blk_t           i, blk, super_blk, old_desc_blk, new_desc_blk;
 190         int             old_desc_blocks;
 191         dgrp_t          g;
 192
 193         if (!(EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 194                                          EXT4_FEATURE_RO_COMPAT_GDT_CSUM)))
 195                 return;
 196
 197         for (g=0; g < fs->group_desc_count; g++) {
 198                 if (!(ext2fs_bg_flags_test(fs, g, EXT2_BG_BLOCK_UNINIT)))
 199                         continue;
 200
 201                 blk = (g * fs->super->s_blocks_per_group) +
 202                         fs->super->s_first_data_block;
 203
 204                 ext2fs_super_and_bgd_loc(fs, g, &super_blk,
 205                                          &old_desc_blk, &new_desc_blk, 0);
 206
 207                 if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
 208                         old_desc_blocks = fs->super->s_first_meta_bg;
 209                 else
 210                         old_desc_blocks = fs->desc_blocks +
 211                                 fs->super->s_reserved_gdt_blocks;
 212
 213                 for (i=0; i < fs->super->s_blocks_per_group; i++, blk++) {
 214                         if (blk >= ext2fs_blocks_count(fs->super))
 215                                 break;
 216                         if ((blk == super_blk) ||
 217                             (old_desc_blk && old_desc_blocks &&
 218                              (blk >= old_desc_blk) &&
 219                              (blk < old_desc_blk + old_desc_blocks)) ||
 220                             (new_desc_blk && (blk == new_desc_blk)) ||
 221                             (blk == ext2fs_block_bitmap_loc(fs, g)) ||
 222                             (blk == ext2fs_inode_bitmap_loc(fs, g)) ||
 223                             (blk >= ext2fs_inode_table_loc(fs, g) &&
 224                              (blk < ext2fs_inode_table_loc(fs, g)
 225                               + fs->inode_blocks_per_group)))
 226                                 ext2fs_fast_mark_block_bitmap2(fs->block_map, blk);
 227                         else
 228                                 ext2fs_fast_unmark_block_bitmap2(fs->block_map, blk);
 229                 }
 230         }
 231 }
 232
 233 /* --------------------------------------------------------------------
 234  *
 235  * Resize processing, phase 1.
 236  *
 237  * In this phase we adjust the in-memory superblock information, and
 238  * initialize any new parts of the inode table.  The new parts of the
 239  * inode table are created in virgin disk space, so we can abort here
 240  * without any side effects.
 241  * --------------------------------------------------------------------
 242  */
 243
 244 /*
 245  * If the group descriptor's bitmap and inode table blocks are valid,
 246  * release them in the new filesystem data structure, and mark them as
 247  * reserved so the old inode table blocks don't get overwritten.
 248  */
 249 static void free_gdp_blocks(ext2_filsys fs,
 250                             ext2fs_block_bitmap reserve_blocks,
 251                             struct ext2_group_desc *gdp)
 252 {
 253         blk_t   blk;
 254         int     j;
 255
 256         if (gdp->bg_block_bitmap &&
 257             (gdp->bg_block_bitmap < ext2fs_blocks_count(fs->super))) {
 258                 ext2fs_block_alloc_stats(fs, gdp->bg_block_bitmap, -1);
 259                 ext2fs_mark_block_bitmap2(reserve_blocks,
 260                                          gdp->bg_block_bitmap);
 261         }
 262
 263         if (gdp->bg_inode_bitmap &&
 264             (gdp->bg_inode_bitmap < ext2fs_blocks_count(fs->super))) {
 265                 ext2fs_block_alloc_stats(fs, gdp->bg_inode_bitmap, -1);
 266                 ext2fs_mark_block_bitmap2(reserve_blocks,
 267                                          gdp->bg_inode_bitmap);
 268         }
 269
 270         if (gdp->bg_inode_table == 0 ||
 271             (gdp->bg_inode_table >= ext2fs_blocks_count(fs->super)))
 272                 return;
 273
 274         for (blk = gdp->bg_inode_table, j = 0;
 275              j < fs->inode_blocks_per_group; j++, blk++) {
 276                 if (blk >= ext2fs_blocks_count(fs->super))
 277                         break;
 278                 ext2fs_block_alloc_stats(fs, blk, -1);
 279                 ext2fs_mark_block_bitmap2(reserve_blocks, blk);
 280         }
 281 }
 282
 283 /*
 284  * This routine is shared by the online and offline resize routines.
 285  * All of the information which is adjusted in memory is done here.
 286  *
 287  * The reserve_blocks parameter is only needed when shrinking the
 288  * filesystem.
 289  */
 290 errcode_t adjust_fs_info(ext2_filsys fs, ext2_filsys old_fs,
 291                          ext2fs_block_bitmap reserve_blocks, blk_t new_size)
 292 {
 293         errcode_t       retval;
 294         int             overhead = 0;
 295         int             rem;
 296         blk_t           blk, group_block;
 297         ext2_ino_t      real_end;
 298         int             adj, old_numblocks, numblocks, adjblocks;
 299         unsigned long   i, j, old_desc_blocks, max_group;
 300         unsigned int    meta_bg, meta_bg_size;
 301         int             has_super, csum_flag;
 302         unsigned long long new_inodes;  /* u64 to check for overflow */
 303         double          percent;
 304
 305         ext2fs_blocks_count_set(fs->super, new_size);
 306
 307 retry:
 308         fs->group_desc_count = ext2fs_div64_ceil(ext2fs_blocks_count(fs->super) -
 309                                        fs->super->s_first_data_block,
 310                                        EXT2_BLOCKS_PER_GROUP(fs->super));
 311         if (fs->group_desc_count == 0)
 312                 return EXT2_ET_TOOSMALL;
 313         fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count,
 314                                           EXT2_DESC_PER_BLOCK(fs->super));
 315
 316         /*
 317          * Overhead is the number of bookkeeping blocks per group.  It
 318          * includes the superblock backup, the group descriptor
 319          * backups, the inode bitmap, the block bitmap, and the inode
 320          * table.
 321          */
 322         overhead = (int) (2 + fs->inode_blocks_per_group);
 323
 324         if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1))
 325                 overhead += 1 + fs->desc_blocks +
 326                         fs->super->s_reserved_gdt_blocks;
 327
 328         /*
 329          * See if the last group is big enough to support the
 330          * necessary data structures.  If not, we need to get rid of
 331          * it.
 332          */
 333         rem = (ext2fs_blocks_count(fs->super) - fs->super->s_first_data_block) %
 334                 fs->super->s_blocks_per_group;
 335         if ((fs->group_desc_count == 1) && rem && (rem < overhead))
 336                 return EXT2_ET_TOOSMALL;
 337         if (rem && (rem < overhead+50)) {
 338                 ext2fs_blocks_count_set(fs->super,
 339                                         ext2fs_blocks_count(fs->super) - rem);
 340                 goto retry;
 341         }
 342         /*
 343          * Adjust the number of inodes
 344          */
 345         new_inodes =(unsigned long long) fs->super->s_inodes_per_group * fs->group_desc_count;
 346         if (new_inodes > ~0U) {
 347                 fprintf(stderr, _("inodes (%llu) must be less than %u"),
 348                                    new_inodes, ~0U);
 349                 return EXT2_ET_TOO_MANY_INODES;
 350         }
 351         fs->super->s_inodes_count = fs->super->s_inodes_per_group *
 352                 fs->group_desc_count;
 353
 354         /*
 355          * Adjust the number of free blocks
 356          */
 357         blk = ext2fs_blocks_count(old_fs->super);
 358         if (blk > ext2fs_blocks_count(fs->super))
 359                 ext2fs_free_blocks_count_set(fs->super,
 360                         ext2fs_free_blocks_count(fs->super) -
 361                         (blk - ext2fs_blocks_count(fs->super)));
 362         else
 363                 ext2fs_free_blocks_count_set(fs->super,
 364                         ext2fs_free_blocks_count(fs->super) +
 365                         (ext2fs_blocks_count(fs->super) - blk));
 366
 367         /*
 368          * Adjust the number of reserved blocks
 369          */
 370         percent = (ext2fs_r_blocks_count(old_fs->super) * 100.0) /
 371                 ext2fs_blocks_count(old_fs->super);
 372         ext2fs_r_blocks_count_set(fs->super,
 373                                   (percent * ext2fs_blocks_count(fs->super) /
 374                                    100.0));
 375
 376         /*
 377          * Adjust the bitmaps for size
 378          */
 379         retval = ext2fs_resize_inode_bitmap2(fs->super->s_inodes_count,
 380                                             fs->super->s_inodes_count,
 381                                             fs->inode_map);
 382         if (retval) goto errout;
 383
 384         real_end = ((EXT2_BLOCKS_PER_GROUP(fs->super)
 385                      * fs->group_desc_count)) - 1 +
 386                              fs->super->s_first_data_block;
 387         retval = ext2fs_resize_block_bitmap2(ext2fs_blocks_count(fs->super)-1,
 388                                             real_end, fs->block_map);
 389
 390         if (retval) goto errout;
 391
 392         /*
 393          * Reallocate the group descriptors as necessary.
 394          */
 395         if (old_fs->desc_blocks != fs->desc_blocks) {
 396                 retval = ext2fs_resize_mem(old_fs->desc_blocks *
 397                                            fs->blocksize,
 398                                            fs->desc_blocks * fs->blocksize,
 399                                            &fs->group_desc);
 400                 if (retval)
 401                         goto errout;
 402                 if (fs->desc_blocks > old_fs->desc_blocks)
 403                         memset((char *) fs->group_desc +
 404                                (old_fs->desc_blocks * fs->blocksize), 0,
 405                                (fs->desc_blocks - old_fs->desc_blocks) *
 406                                fs->blocksize);
 407         }
 408
 409         /*
 410          * If the resize_inode feature is set, and we are changing the
 411          * number of descriptor blocks, then adjust
 412          * s_reserved_gdt_blocks if possible to avoid needing to move
 413          * the inode table either now or in the future.
 414          */
 415         if ((fs->super->s_feature_compat &
 416              EXT2_FEATURE_COMPAT_RESIZE_INODE) &&
 417             (old_fs->desc_blocks != fs->desc_blocks)) {
 418                 int new;
 419
 420                 new = ((int) fs->super->s_reserved_gdt_blocks) +
 421                         (old_fs->desc_blocks - fs->desc_blocks);
 422                 if (new < 0)
 423                         new = 0;
 424                 if (new > (int) fs->blocksize/4)
 425                         new = fs->blocksize/4;
 426                 fs->super->s_reserved_gdt_blocks = new;
 427         }
 428
 429         /*
 430          * If we are shrinking the number of block groups, we're done
 431          * and can exit now.
 432          */
 433         if (old_fs->group_desc_count > fs->group_desc_count) {
 434                 /*
 435                  * Check the block groups that we are chopping off
 436                  * and free any blocks associated with their metadata
 437                  */
 438                 for (i = fs->group_desc_count;
 439                      i < old_fs->group_desc_count; i++) {
 440                         free_gdp_blocks(fs, reserve_blocks,
 441                                         ext2fs_group_desc(old_fs,
 442                                                 old_fs->group_desc, i));
 443                 }
 444                 retval = 0;
 445                 goto errout;
 446         }
 447
 448         /*
 449          * Fix the count of the last (old) block group
 450          */
 451         old_numblocks = (ext2fs_blocks_count(old_fs->super) -
 452                          old_fs->super->s_first_data_block) %
 453                                  old_fs->super->s_blocks_per_group;
 454         if (!old_numblocks)
 455                 old_numblocks = old_fs->super->s_blocks_per_group;
 456         if (old_fs->group_desc_count == fs->group_desc_count) {
 457                 numblocks = (ext2fs_blocks_count(fs->super) -
 458                              fs->super->s_first_data_block) %
 459                         fs->super->s_blocks_per_group;
 460                 if (!numblocks)
 461                         numblocks = fs->super->s_blocks_per_group;
 462         } else
 463                 numblocks = fs->super->s_blocks_per_group;
 464         i = old_fs->group_desc_count - 1;
 465         ext2fs_bg_free_blocks_count_set(fs, i, ext2fs_bg_free_blocks_count(fs, i) + (numblocks - old_numblocks));
 466         ext2fs_group_desc_csum_set(fs, i);
 467
 468         /*
 469          * If the number of block groups is staying the same, we're
 470          * done and can exit now.  (If the number block groups is
 471          * shrinking, we had exited earlier.)
 472          */
 473         if (old_fs->group_desc_count >= fs->group_desc_count) {
 474                 retval = 0;
 475                 goto errout;
 476         }
 477
 478         /*
 479          * Initialize the new block group descriptors
 480          */
 481         group_block = fs->super->s_first_data_block +
 482                 old_fs->group_desc_count * fs->super->s_blocks_per_group;
 483
 484         csum_flag = EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 485                                                EXT4_FEATURE_RO_COMPAT_GDT_CSUM);
 486         adj = old_fs->group_desc_count;
 487         max_group = fs->group_desc_count - adj;
 488         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
 489                 old_desc_blocks = fs->super->s_first_meta_bg;
 490         else
 491                 old_desc_blocks = fs->desc_blocks +
 492                         fs->super->s_reserved_gdt_blocks;
 493         for (i = old_fs->group_desc_count;
 494              i < fs->group_desc_count; i++) {
 495                 memset(ext2fs_group_desc(fs, fs->group_desc, i), 0,
 496                        sizeof(struct ext2_group_desc));
 497                 adjblocks = 0;
 498
 499                 ext2fs_bg_flags_zap(fs, i);
 500                 if (csum_flag)
 501                         ext2fs_bg_flags_set(fs, i, EXT2_BG_INODE_UNINIT | EXT2_BG_INODE_ZEROED);
 502                 if (i == fs->group_desc_count-1) {
 503                         numblocks = (ext2fs_blocks_count(fs->super) -
 504                                      fs->super->s_first_data_block) %
 505                                              fs->super->s_blocks_per_group;
 506                         if (!numblocks)
 507                                 numblocks = fs->super->s_blocks_per_group;
 508                 } else {
 509                         numblocks = fs->super->s_blocks_per_group;
 510                         if (csum_flag)
 511                                 ext2fs_bg_flags_set(fs, i,
 512                                                     EXT2_BG_BLOCK_UNINIT);
 513                 }
 514
 515                 has_super = ext2fs_bg_has_super(fs, i);
 516                 if (has_super) {
 517                         ext2fs_block_alloc_stats2(fs, group_block, +1);
 518                         adjblocks++;
 519                 }
 520                 meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
 521                 meta_bg = i / meta_bg_size;
 522                 if (!(fs->super->s_feature_incompat &
 523                       EXT2_FEATURE_INCOMPAT_META_BG) ||
 524                     (meta_bg < fs->super->s_first_meta_bg)) {
 525                         if (has_super) {
 526                                 for (j=0; j < old_desc_blocks; j++)
 527                                         ext2fs_block_alloc_stats2(fs,
 528                                                  group_block + 1 + j, +1);
 529                                 adjblocks += old_desc_blocks;
 530                         }
 531                 } else {
 532                         if (has_super)
 533                                 has_super = 1;
 534                         if (((i % meta_bg_size) == 0) ||
 535                             ((i % meta_bg_size) == 1) ||
 536                             ((i % meta_bg_size) == (meta_bg_size-1)))
 537                                 ext2fs_block_alloc_stats2(fs,
 538                                                  group_block + has_super, +1);
 539                 }
 540
 541                 adjblocks += 2 + fs->inode_blocks_per_group;
 542
 543                 numblocks -= adjblocks;
 544                 ext2fs_free_blocks_count_set(fs->super,
 545                              ext2fs_free_blocks_count(fs->super) - adjblocks);
 546                 fs->super->s_free_inodes_count +=
 547                         fs->super->s_inodes_per_group;
 548                 ext2fs_bg_free_blocks_count_set(fs, i, numblocks);
 549                 ext2fs_bg_free_inodes_count_set(fs, i,
 550                                                 fs->super->s_inodes_per_group);
 551                 ext2fs_bg_used_dirs_count_set(fs, i, 0);
 552                 ext2fs_group_desc_csum_set(fs, i);
 553
 554                 retval = ext2fs_allocate_group_table(fs, i, 0);
 555                 if (retval) goto errout;
 556
 557                 group_block += fs->super->s_blocks_per_group;
 558         }
 559         retval = 0;
 560
 561 errout:
 562         return (retval);
 563 }
 564
 565 /*
 566  * This routine adjusts the superblock and other data structures, both
 567  * in disk as well as in memory...
 568  */
 569 static errcode_t adjust_superblock(ext2_resize_t rfs, blk_t new_size)
 570 {
 571         ext2_filsys fs;
 572         int             adj = 0;
 573         errcode_t       retval;
 574         blk_t           group_block;
 575         unsigned long   i;
 576         unsigned long   max_group;
 577
 578         fs = rfs->new_fs;
 579         ext2fs_mark_super_dirty(fs);
 580         ext2fs_mark_bb_dirty(fs);
 581         ext2fs_mark_ib_dirty(fs);
 582
 583         retval = ext2fs_allocate_block_bitmap(fs, _("reserved blocks"),
 584                                               &rfs->reserve_blocks);
 585         if (retval)
 586                 return retval;
 587
 588         retval = adjust_fs_info(fs, rfs->old_fs, rfs->reserve_blocks, new_size);
 589         if (retval)
 590                 goto errout;
 591
 592         /*
 593          * Check to make sure there are enough inodes
 594          */
 595         if ((rfs->old_fs->super->s_inodes_count -
 596              rfs->old_fs->super->s_free_inodes_count) >
 597             rfs->new_fs->super->s_inodes_count) {
 598                 retval = ENOSPC;
 599                 goto errout;
 600         }
 601
 602         /*
 603          * If we are shrinking the number block groups, we're done and
 604          * can exit now.
 605          */
 606         if (rfs->old_fs->group_desc_count > fs->group_desc_count) {
 607                 retval = 0;
 608                 goto errout;
 609         }
 610
 611         /*
 612          * If the number of block groups is staying the same, we're
 613          * done and can exit now.  (If the number block groups is
 614          * shrinking, we had exited earlier.)
 615          */
 616         if (rfs->old_fs->group_desc_count >= fs->group_desc_count) {
 617                 retval = 0;
 618                 goto errout;
 619         }
 620
 621         /*
 622          * Initialize the new block group descriptors
 623          */
 624         retval = ext2fs_get_array(fs->blocksize, fs->inode_blocks_per_group,
 625                                 &rfs->itable_buf);
 626         if (retval)
 627                 goto errout;
 628
 629         memset(rfs->itable_buf, 0, fs->blocksize * fs->inode_blocks_per_group);
 630         group_block = fs->super->s_first_data_block +
 631                 rfs->old_fs->group_desc_count * fs->super->s_blocks_per_group;
 632
 633         adj = rfs->old_fs->group_desc_count;
 634         max_group = fs->group_desc_count - adj;
 635         if (rfs->progress) {
 636                 retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
 637                                        0, max_group);
 638                 if (retval)
 639                         goto errout;
 640         }
 641         for (i = rfs->old_fs->group_desc_count;
 642              i < fs->group_desc_count; i++) {
 643                 /*
 644                  * Write out the new inode table
 645                  */
 646                 retval = io_channel_write_blk64(fs->io,
 647                                                 ext2fs_inode_table_loc(fs, i),
 648                                                 fs->inode_blocks_per_group,
 649                                                 rfs->itable_buf);
 650                 if (retval) goto errout;
 651
 652                 io_channel_flush(fs->io);
 653                 if (rfs->progress) {
 654                         retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
 655                                                i - adj + 1, max_group);
 656                         if (retval)
 657                                 goto errout;
 658                 }
 659                 group_block += fs->super->s_blocks_per_group;
 660         }
 661         io_channel_flush(fs->io);
 662         retval = 0;
 663
 664 errout:
 665         return retval;
 666 }
 667
 668 /* --------------------------------------------------------------------
 669  *
 670  * Resize processing, phase 2.
 671  *
 672  * In this phase we adjust determine which blocks need to be moved, in
 673  * blocks_to_move().  We then copy the blocks to their ultimate new
 674  * destinations using block_mover().  Since we are copying blocks to
 675  * their new locations, again during this pass we can abort without
 676  * any problems.
 677  * --------------------------------------------------------------------
 678  */
 679
 680 /*
 681  * This helper function creates a block bitmap with all of the
 682  * filesystem meta-data blocks.
 683  */
 684 static errcode_t mark_table_blocks(ext2_filsys fs,
 685                                    ext2fs_block_bitmap bmap)
 686 {
 687         blk_t                   b;
 688         unsigned int            j;
 689         dgrp_t                  i;
 690         unsigned long           meta_bg_size;
 691         unsigned int            old_desc_blocks;
 692
 693         meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
 694         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
 695                 old_desc_blocks = fs->super->s_first_meta_bg;
 696         else
 697                 old_desc_blocks = fs->desc_blocks +
 698                         fs->super->s_reserved_gdt_blocks;
 699         for (i = 0; i < fs->group_desc_count; i++) {
 700                 ext2fs_reserve_super_and_bgd(fs, i, bmap);
 701
 702                 /*
 703                  * Mark the blocks used for the inode table
 704                  */
 705                 for (j = 0, b = ext2fs_inode_table_loc(fs, i);
 706                      j < (unsigned int) fs->inode_blocks_per_group;
 707                      j++, b++)
 708                         ext2fs_mark_block_bitmap2(bmap, b);
 709
 710                 /*
 711                  * Mark block used for the block bitmap
 712                  */
 713                 ext2fs_mark_block_bitmap2(bmap,
 714                                          ext2fs_block_bitmap_loc(fs, i));
 715
 716                 /*
 717                  * Mark block used for the inode bitmap
 718                  */
 719                 ext2fs_mark_block_bitmap2(bmap,
 720                                          ext2fs_inode_bitmap_loc(fs, i));
 721         }
 722         return 0;
 723 }
 724
 725 /*
 726  * This function checks to see if a particular block (either a
 727  * superblock or a block group descriptor) overlaps with an inode or
 728  * block bitmap block, or with the inode table.
 729  */
 730 static void mark_fs_metablock(ext2_resize_t rfs,
 731                               ext2fs_block_bitmap meta_bmap,
 732                               int group, blk_t blk)
 733 {
 734         ext2_filsys     fs = rfs->new_fs;
 735
 736         ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
 737         ext2fs_block_alloc_stats2(fs, blk, +1);
 738
 739         /*
 740          * Check to see if we overlap with the inode or block bitmap,
 741          * or the inode tables.  If not, and the block is in use, then
 742          * mark it as a block to be moved.
 743          */
 744         if (IS_BLOCK_BM(fs, group, blk)) {
 745                 ext2fs_block_bitmap_loc_set(fs, group, 0);
 746                 rfs->needed_blocks++;
 747         } else if (IS_INODE_BM(fs, group, blk)) {
 748                 ext2fs_inode_bitmap_loc_set(fs, group, 0);
 749                 rfs->needed_blocks++;
 750         } else if (IS_INODE_TB(fs, group, blk)) {
 751                 ext2fs_inode_table_loc_set(fs, group, 0);
 752                 rfs->needed_blocks++;
 753         } else if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 754                                               EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
 755                    (ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT))) {
 756                 /*
 757                  * If the block bitmap is uninitialized, which means
 758                  * nothing other than standard metadata in use.
 759                  */
 760                 return;
 761         } else if (ext2fs_test_block_bitmap2(rfs->old_fs->block_map, blk) &&
 762                    !ext2fs_test_block_bitmap2(meta_bmap, blk)) {
 763                 ext2fs_mark_block_bitmap2(rfs->move_blocks, blk);
 764                 rfs->needed_blocks++;
 765         }
 766 }
 767
 768
 769 /*
 770  * This routine marks and unmarks reserved blocks in the new block
 771  * bitmap.  It also determines which blocks need to be moved and
 772  * places this information into the move_blocks bitmap.
 773  */
 774 static errcode_t blocks_to_move(ext2_resize_t rfs)
 775 {
 776         int             j, has_super;
 777         dgrp_t          i, max_groups, g;
 778         blk_t           blk, group_blk;
 779         unsigned long   old_blocks, new_blocks;
 780         unsigned int    meta_bg, meta_bg_size;
 781         errcode_t       retval;
 782         ext2_filsys     fs, old_fs;
 783         ext2fs_block_bitmap     meta_bmap;
 784         __u32           save_incompat_flag;
 785
 786         fs = rfs->new_fs;
 787         old_fs = rfs->old_fs;
 788         if (ext2fs_blocks_count(old_fs->super) > ext2fs_blocks_count(fs->super))
 789                 fs = rfs->old_fs;
 790
 791         retval = ext2fs_allocate_block_bitmap(fs, _("blocks to be moved"),
 792                                               &rfs->move_blocks);
 793         if (retval)
 794                 return retval;
 795
 796         retval = ext2fs_allocate_block_bitmap(fs, _("meta-data blocks"),
 797                                               &meta_bmap);
 798         if (retval)
 799                 return retval;
 800
 801         retval = mark_table_blocks(old_fs, meta_bmap);
 802         if (retval)
 803                 return retval;
 804
 805         fs = rfs->new_fs;
 806
 807         /*
 808          * If we're shrinking the filesystem, we need to move all of
 809          * the blocks that don't fit any more
 810          */
 811         for (blk = ext2fs_blocks_count(fs->super);
 812              blk < ext2fs_blocks_count(old_fs->super); blk++) {
 813                 g = ext2fs_group_of_blk2(fs, blk);
 814                 if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 815                                                EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
 816                     ext2fs_bg_flags_test(old_fs, g, EXT2_BG_BLOCK_UNINIT)) {
 817                         /*
 818                          * The block bitmap is uninitialized, so skip
 819                          * to the next block group.
 820                          */
 821                         blk = ((g+1) * fs->super->s_blocks_per_group) +
 822                                 fs->super->s_first_data_block - 1;
 823                         continue;
 824                 }
 825                 if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
 826                     !ext2fs_test_block_bitmap2(meta_bmap, blk)) {
 827                         ext2fs_mark_block_bitmap2(rfs->move_blocks, blk);
 828                         rfs->needed_blocks++;
 829                 }
 830                 ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
 831         }
 832
 833         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) {
 834                 old_blocks = old_fs->super->s_first_meta_bg;
 835                 new_blocks = fs->super->s_first_meta_bg;
 836         } else {
 837                 old_blocks = old_fs->desc_blocks + old_fs->super->s_reserved_gdt_blocks;
 838                 new_blocks = fs->desc_blocks + fs->super->s_reserved_gdt_blocks;
 839         }
 840
 841         if (old_blocks == new_blocks) {
 842                 retval = 0;
 843                 goto errout;
 844         }
 845
 846         max_groups = fs->group_desc_count;
 847         if (max_groups > old_fs->group_desc_count)
 848                 max_groups = old_fs->group_desc_count;
 849         group_blk = old_fs->super->s_first_data_block;
 850         /*
 851          * If we're reducing the number of descriptor blocks, this
 852          * makes life easy.  :-)   We just have to mark some extra
 853          * blocks as free.
 854          */
 855         if (old_blocks > new_blocks) {
 856                 for (i = 0; i < max_groups; i++) {
 857                         if (!ext2fs_bg_has_super(fs, i)) {
 858                                 group_blk += fs->super->s_blocks_per_group;
 859                                 continue;
 860                         }
 861                         for (blk = group_blk+1+new_blocks;
 862                              blk < group_blk+1+old_blocks; blk++) {
 863                                 ext2fs_block_alloc_stats2(fs, blk, -1);
 864                                 rfs->needed_blocks--;
 865                         }
 866                         group_blk += fs->super->s_blocks_per_group;
 867                 }
 868                 retval = 0;
 869                 goto errout;
 870         }
 871         /*
 872          * If we're increasing the number of descriptor blocks, life
 873          * gets interesting....
 874          */
 875         meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
 876         for (i = 0; i < max_groups; i++) {
 877                 has_super = ext2fs_bg_has_super(fs, i);
 878                 if (has_super)
 879                         mark_fs_metablock(rfs, meta_bmap, i, group_blk);
 880
 881                 meta_bg = i / meta_bg_size;
 882                 if (!(fs->super->s_feature_incompat &
 883                       EXT2_FEATURE_INCOMPAT_META_BG) ||
 884                     (meta_bg < fs->super->s_first_meta_bg)) {
 885                         if (has_super) {
 886                                 for (blk = group_blk+1;
 887                                      blk < group_blk + 1 + new_blocks; blk++)
 888                                         mark_fs_metablock(rfs, meta_bmap,
 889                                                           i, blk);
 890                         }
 891                 } else {
 892                         if (has_super)
 893                                 has_super = 1;
 894                         if (((i % meta_bg_size) == 0) ||
 895                             ((i % meta_bg_size) == 1) ||
 896                             ((i % meta_bg_size) == (meta_bg_size-1)))
 897                                 mark_fs_metablock(rfs, meta_bmap, i,
 898                                                   group_blk + has_super);
 899                 }
 900
 901                 if (ext2fs_inode_table_loc(fs, i) &&
 902                     ext2fs_inode_bitmap_loc(fs, i) &&
 903                     ext2fs_block_bitmap_loc(fs, i))
 904                         goto next_group;
 905
 906                 /*
 907                  * Reserve the existing meta blocks that we know
 908                  * aren't to be moved.
 909                  */
 910                 if (ext2fs_block_bitmap_loc(fs, i))
 911                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
 912                                  ext2fs_block_bitmap_loc(fs, i));
 913                 if (ext2fs_inode_bitmap_loc(fs, i))
 914                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
 915                                  ext2fs_inode_bitmap_loc(fs, i));
 916                 if (ext2fs_inode_table_loc(fs, i))
 917                         for (blk = ext2fs_inode_table_loc(fs, i), j=0;
 918                              j < fs->inode_blocks_per_group ; j++, blk++)
 919                                 ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
 920                                                          blk);
 921
 922                 /*
 923                  * Allocate the missing data structures
 924                  *
 925                  * XXX We have a problem with FLEX_BG and off-line
 926                  * resizing where we are growing the size of the
 927                  * filesystem.  ext2fs_allocate_group_table() will try
 928                  * to reserve the inode table in the desired flex_bg
 929                  * location.  However, passing rfs->reserve_blocks
 930                  * doesn't work since it only has reserved the blocks
 931                  * that will be used in the new block group -- and
 932                  * with flex_bg, we can and will allocate the tables
 933                  * outside of the block group.  And we can't pass in
 934                  * the fs->block_map because it doesn't handle
 935                  * overlapping inode table movements right.  So for
 936                  * now, we temporarily disable flex_bg to force
 937                  * ext2fs_allocate_group_tables() to allocate the bg
 938                  * metadata in side the block group, and the restore
 939                  * it afterwards.  Ugly, until we can fix this up
 940                  * right later.
 941                  */
 942                 save_incompat_flag = fs->super->s_feature_incompat;
 943                 fs->super->s_feature_incompat &= ~EXT4_FEATURE_INCOMPAT_FLEX_BG;
 944                 retval = ext2fs_allocate_group_table(fs, i,
 945                                                      rfs->reserve_blocks);
 946                 fs->super->s_feature_incompat = save_incompat_flag;
 947                 if (retval)
 948                         goto errout;
 949
 950                 /*
 951                  * For those structures that have changed, we need to
 952                  * do bookkeepping.
 953                  */
 954                 if (ext2fs_block_bitmap_loc(old_fs, i) !=
 955                     (blk = ext2fs_block_bitmap_loc(fs, i))) {
 956                         ext2fs_block_alloc_stats2(fs, blk, +1);
 957                         if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
 958                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
 959                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
 960                                                          blk);
 961                 }
 962                 if (ext2fs_inode_bitmap_loc(old_fs, i) !=
 963                     (blk = ext2fs_inode_bitmap_loc(fs, i))) {
 964                         ext2fs_block_alloc_stats2(fs, blk, +1);
 965                         if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
 966                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
 967                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
 968                                                          blk);
 969                 }
 970
 971                 /*
 972                  * The inode table, if we need to relocate it, is
 973                  * handled specially.  We have to reserve the blocks
 974                  * for both the old and the new inode table, since we
 975                  * can't have the inode table be destroyed during the
 976                  * block relocation phase.
 977                  */
 978                 if (ext2fs_inode_table_loc(fs, i) == ext2fs_inode_table_loc(old_fs, i))
 979                         goto next_group; /* inode table not moved */
 980
 981                 rfs->needed_blocks += fs->inode_blocks_per_group;
 982
 983                 /*
 984                  * Mark the new inode table as in use in the new block
 985                  * allocation bitmap, and move any blocks that might
 986                  * be necessary.
 987                  */
 988                 for (blk = ext2fs_inode_table_loc(fs, i), j=0;
 989                      j < fs->inode_blocks_per_group ; j++, blk++) {
 990                         ext2fs_block_alloc_stats2(fs, blk, +1);
 991                         if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
 992                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
 993                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
 994                                                          blk);
 995                 }
 996
 997                 /*
 998                  * Make sure the old inode table is reserved in the
 999                  * block reservation bitmap.
1000                  */
1001                 for (blk = ext2fs_inode_table_loc(rfs->old_fs, i), j=0;
1002                      j < fs->inode_blocks_per_group ; j++, blk++)
1003                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
1004
1005         next_group:
1006                 group_blk += rfs->new_fs->super->s_blocks_per_group;
1007         }
1008         retval = 0;
1009
1010 errout:
1011         if (meta_bmap)
1012                 ext2fs_free_block_bitmap(meta_bmap);
1013
1014         return retval;
1015 }
1016
1017 /*
1018  * This helper function tries to allocate a new block.  We try to
1019  * avoid hitting the original group descriptor blocks at least at
1020  * first, since we want to make it possible to recover from a badly
1021  * aborted resize operation as much as possible.
1022  *
1023  * In the future, I may further modify this routine to balance out
1024  * where we get the new blocks across the various block groups.
1025  * Ideally we would allocate blocks that corresponded with the block
1026  * group of the containing inode, and keep contiguous blocks
1027  * together.  However, this very difficult to do efficiently, since we
1028  * don't have the necessary information up front.
1029  */
1030
1031 #define AVOID_OLD       1
1032 #define DESPERATION     2
1033
1034 static void init_block_alloc(ext2_resize_t rfs)
1035 {
1036         rfs->alloc_state = AVOID_OLD;
1037         rfs->new_blk = rfs->new_fs->super->s_first_data_block;
1038 #if 0
1039         /* HACK for testing */
1040         if (ext2fs_blocks_count(rfs->new_fs->super) >
1041             ext2fs_blocks_count(rfs->old_fs->super))
1042                 rfs->new_blk = ext2fs_blocks_count(rfs->old_fs->super);
1043 #endif
1044 }
1045
1046 static blk_t get_new_block(ext2_resize_t rfs)
1047 {
1048         ext2_filsys     fs = rfs->new_fs;
1049
1050         while (1) {
1051                 if (rfs->new_blk >= ext2fs_blocks_count(fs->super)) {
1052                         if (rfs->alloc_state == DESPERATION)
1053                                 return 0;
1054
1055 #ifdef RESIZE2FS_DEBUG
1056                         if (rfs->flags & RESIZE_DEBUG_BMOVE)
1057                                 printf("Going into desperation mode "
1058                                        "for block allocations\n");
1059 #endif
1060                         rfs->alloc_state = DESPERATION;
1061                         rfs->new_blk = fs->super->s_first_data_block;
1062                         continue;
1063                 }
1064                 if (ext2fs_test_block_bitmap2(fs->block_map, rfs->new_blk) ||
1065                     ext2fs_test_block_bitmap2(rfs->reserve_blocks,
1066                                              rfs->new_blk) ||
1067                     ((rfs->alloc_state == AVOID_OLD) &&
1068                      (rfs->new_blk < ext2fs_blocks_count(rfs->old_fs->super)) &&
1069                      ext2fs_test_block_bitmap2(rfs->old_fs->block_map,
1070                                               rfs->new_blk))) {
1071                         rfs->new_blk++;
1072                         continue;
1073                 }
1074                 return rfs->new_blk;
1075         }
1076 }
1077
1078 static errcode_t resize2fs_get_alloc_block(ext2_filsys fs, blk64_t goal,
1079                                            blk64_t *ret)
1080 {
1081         ext2_resize_t rfs = (ext2_resize_t) fs->priv_data;
1082         blk_t blk;
1083
1084         blk = get_new_block(rfs);
1085         if (!blk)
1086                 return ENOSPC;
1087
1088 #ifdef RESIZE2FS_DEBUG
1089         if (rfs->flags & 0xF)
1090                 printf("get_alloc_block allocating %u\n", blk);
1091 #endif
1092
1093         ext2fs_mark_block_bitmap2(rfs->old_fs->block_map, blk);
1094         ext2fs_mark_block_bitmap2(rfs->new_fs->block_map, blk);
1095         *ret = (blk64_t) blk;
1096         return 0;
1097 }
1098
1099 static errcode_t block_mover(ext2_resize_t rfs)
1100 {
1101         blk_t                   blk, old_blk, new_blk;
1102         ext2_filsys             fs = rfs->new_fs;
1103         ext2_filsys             old_fs = rfs->old_fs;
1104         errcode_t               retval;
1105         int                     size, c;
1106         int                     to_move, moved;
1107         ext2_badblocks_list     badblock_list = 0;
1108         int                     bb_modified = 0;
1109
1110         fs->get_alloc_block = resize2fs_get_alloc_block;
1111         old_fs->get_alloc_block = resize2fs_get_alloc_block;
1112
1113         retval = ext2fs_read_bb_inode(old_fs, &badblock_list);
1114         if (retval)
1115                 return retval;
1116
1117         new_blk = fs->super->s_first_data_block;
1118         if (!rfs->itable_buf) {
1119                 retval = ext2fs_get_array(fs->blocksize,
1120                                         fs->inode_blocks_per_group,
1121                                         &rfs->itable_buf);
1122                 if (retval)
1123                         return retval;
1124         }
1125         retval = ext2fs_create_extent_table(&rfs->bmap, 0);
1126         if (retval)
1127                 return retval;
1128
1129         /*
1130          * The first step is to figure out where all of the blocks
1131          * will go.
1132          */
1133         to_move = moved = 0;
1134         init_block_alloc(rfs);
1135         for (blk = old_fs->super->s_first_data_block;
1136              blk < ext2fs_blocks_count(old_fs->super); blk++) {
1137                 if (!ext2fs_test_block_bitmap2(old_fs->block_map, blk))
1138                         continue;
1139                 if (!ext2fs_test_block_bitmap2(rfs->move_blocks, blk))
1140                         continue;
1141                 if (ext2fs_badblocks_list_test(badblock_list, blk)) {
1142                         ext2fs_badblocks_list_del(badblock_list, blk);
1143                         bb_modified++;
1144                         continue;
1145                 }
1146
1147                 new_blk = get_new_block(rfs);
1148                 if (!new_blk) {
1149                         retval = ENOSPC;
1150                         goto errout;
1151                 }
1152                 ext2fs_block_alloc_stats2(fs, new_blk, +1);
1153                 ext2fs_add_extent_entry(rfs->bmap, blk, new_blk);
1154                 to_move++;
1155         }
1156
1157         if (to_move == 0) {
1158                 if (rfs->bmap) {
1159                         ext2fs_free_extent_table(rfs->bmap);
1160                         rfs->bmap = 0;
1161                 }
1162                 retval = 0;
1163                 goto errout;
1164         }
1165
1166         /*
1167          * Step two is to actually move the blocks
1168          */
1169         retval =  ext2fs_iterate_extent(rfs->bmap, 0, 0, 0);
1170         if (retval) goto errout;
1171
1172         if (rfs->progress) {
1173                 retval = (rfs->progress)(rfs, E2_RSZ_BLOCK_RELOC_PASS,
1174                                          0, to_move);
1175                 if (retval)
1176                         goto errout;
1177         }
1178         while (1) {
1179                 retval = ext2fs_iterate_extent(rfs->bmap, &old_blk, &new_blk, &size);
1180                 if (retval) goto errout;
1181                 if (!size)
1182                         break;
1183 #ifdef RESIZE2FS_DEBUG
1184                 if (rfs->flags & RESIZE_DEBUG_BMOVE)
1185                         printf("Moving %d blocks %u->%u\n",
1186                                size, old_blk, new_blk);
1187 #endif
1188                 do {
1189                         c = size;
1190                         if (c > fs->inode_blocks_per_group)
1191                                 c = fs->inode_blocks_per_group;
1192                         retval = io_channel_read_blk64(fs->io, old_blk, c,
1193                                                        rfs->itable_buf);
1194                         if (retval) goto errout;
1195                         retval = io_channel_write_blk64(fs->io, new_blk, c,
1196                                                         rfs->itable_buf);
1197                         if (retval) goto errout;
1198                         size -= c;
1199                         new_blk += c;
1200                         old_blk += c;
1201                         moved += c;
1202                         if (rfs->progress) {
1203                                 io_channel_flush(fs->io);
1204                                 retval = (rfs->progress)(rfs,
1205                                                 E2_RSZ_BLOCK_RELOC_PASS,
1206                                                 moved, to_move);
1207                                 if (retval)
1208                                         goto errout;
1209                         }
1210                 } while (size > 0);
1211                 io_channel_flush(fs->io);
1212         }
1213
1214 errout:
1215         if (badblock_list) {
1216                 if (!retval && bb_modified)
1217                         retval = ext2fs_update_bb_inode(old_fs,
1218                                                         badblock_list);
1219                 ext2fs_badblocks_list_free(badblock_list);
1220         }
1221         return retval;
1222 }
1223
1224
1225 /* --------------------------------------------------------------------
1226  *
1227  * Resize processing, phase 3
1228  *
1229  * --------------------------------------------------------------------
1230  */
1231
1232
1233 struct process_block_struct {
1234         ext2_resize_t           rfs;
1235         ext2_ino_t              ino;
1236         struct ext2_inode *     inode;
1237         errcode_t               error;
1238         int                     is_dir;
1239         int                     changed;
1240 };
1241
1242 static int process_block(ext2_filsys fs, blk_t  *block_nr,
1243                          e2_blkcnt_t blockcnt,
1244                          blk_t ref_block EXT2FS_ATTR((unused)),
1245                          int ref_offset EXT2FS_ATTR((unused)), void *priv_data)
1246 {
1247         struct process_block_struct *pb;
1248         errcode_t       retval;
1249         blk_t           block, new_block;
1250         int             ret = 0;
1251
1252         pb = (struct process_block_struct *) priv_data;
1253         block = *block_nr;
1254         if (pb->rfs->bmap) {
1255                 new_block = ext2fs_extent_translate(pb->rfs->bmap, block);
1256                 if (new_block) {
1257                         *block_nr = new_block;
1258                         ret |= BLOCK_CHANGED;
1259                         pb->changed = 1;
1260 #ifdef RESIZE2FS_DEBUG
1261                         if (pb->rfs->flags & RESIZE_DEBUG_BMOVE)
1262                                 printf("ino=%u, blockcnt=%lld, %u->%u\n",
1263                                        pb->ino, blockcnt, block, new_block);
1264 #endif
1265                         block = new_block;
1266                 }
1267         }
1268         if (pb->is_dir) {
1269                 retval = ext2fs_add_dir_block(fs->dblist, pb->ino,
1270                                               block, (int) blockcnt);
1271                 if (retval) {
1272                         pb->error = retval;
1273                         ret |= BLOCK_ABORT;
1274                 }
1275         }
1276         return ret;
1277 }
1278
1279 /*
1280  * Progress callback
1281  */
1282 static errcode_t progress_callback(ext2_filsys fs,
1283                                    ext2_inode_scan scan EXT2FS_ATTR((unused)),
1284                                    dgrp_t group, void * priv_data)
1285 {
1286         ext2_resize_t rfs = (ext2_resize_t) priv_data;
1287         errcode_t               retval;
1288
1289         /*
1290          * This check is to protect against old ext2 libraries.  It
1291          * shouldn't be needed against new libraries.
1292          */
1293         if ((group+1) == 0)
1294                 return 0;
1295
1296         if (rfs->progress) {
1297                 io_channel_flush(fs->io);
1298                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
1299                                          group+1, fs->group_desc_count);
1300                 if (retval)
1301                         return retval;
1302         }
1303
1304         return 0;
1305 }
1306
1307 static errcode_t inode_scan_and_fix(ext2_resize_t rfs)
1308 {
1309         struct process_block_struct     pb;
1310         ext2_ino_t              ino, new_inode;
1311         struct ext2_inode       *inode = NULL;
1312         ext2_inode_scan         scan = NULL;
1313         errcode_t               retval;
1314         char                    *block_buf = 0;
1315         ext2_ino_t              start_to_move;
1316         blk_t                   orig_size, new_block;
1317         int                     inode_size;
1318
1319         if ((rfs->old_fs->group_desc_count <=
1320              rfs->new_fs->group_desc_count) &&
1321             !rfs->bmap)
1322                 return 0;
1323
1324         /*
1325          * Save the original size of the old filesystem, and
1326          * temporarily set the size to be the new size if the new size
1327          * is larger.  We need to do this to avoid catching an error
1328          * by the block iterator routines
1329          */
1330         orig_size = ext2fs_blocks_count(rfs->old_fs->super);
1331         if (orig_size < ext2fs_blocks_count(rfs->new_fs->super))
1332                 ext2fs_blocks_count_set(rfs->old_fs->super,
1333                                 ext2fs_blocks_count(rfs->new_fs->super));
1334
1335         retval = ext2fs_open_inode_scan(rfs->old_fs, 0, &scan);
1336         if (retval) goto errout;
1337
1338         retval = ext2fs_init_dblist(rfs->old_fs, 0);
1339         if (retval) goto errout;
1340         retval = ext2fs_get_array(rfs->old_fs->blocksize, 3, &block_buf);
1341         if (retval) goto errout;
1342
1343         start_to_move = (rfs->new_fs->group_desc_count *
1344                          rfs->new_fs->super->s_inodes_per_group);
1345
1346         if (rfs->progress) {
1347                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
1348                                          0, rfs->old_fs->group_desc_count);
1349                 if (retval)
1350                         goto errout;
1351         }
1352         ext2fs_set_inode_callback(scan, progress_callback, (void *) rfs);
1353         pb.rfs = rfs;
1354         pb.inode = inode;
1355         pb.error = 0;
1356         new_inode = EXT2_FIRST_INODE(rfs->new_fs->super);
1357         inode_size = EXT2_INODE_SIZE(rfs->new_fs->super);
1358         inode = malloc(inode_size);
1359         if (!inode) {
1360                 retval = ENOMEM;
1361                 goto errout;
1362         }
1363         /*
1364          * First, copy all of the inodes that need to be moved
1365          * elsewhere in the inode table
1366          */
1367         while (1) {
1368                 retval = ext2fs_get_next_inode_full(scan, &ino, inode, inode_size);
1369                 if (retval) goto errout;
1370                 if (!ino)
1371                         break;
1372
1373                 if (inode->i_links_count == 0 && ino != EXT2_RESIZE_INO)
1374                         continue; /* inode not in use */
1375
1376                 pb.is_dir = LINUX_S_ISDIR(inode->i_mode);
1377                 pb.changed = 0;
1378
1379                 if (ext2fs_file_acl_block(inode) && rfs->bmap) {
1380                         new_block = ext2fs_extent_translate(rfs->bmap,
1381                                                             ext2fs_file_acl_block(inode));
1382                         if (new_block) {
1383                                 ext2fs_file_acl_block_set(inode, new_block);
1384                                 retval = ext2fs_write_inode_full(rfs->old_fs,
1385                                                             ino, inode, inode_size);
1386                                 if (retval) goto errout;
1387                         }
1388                 }
1389
1390                 if (ext2fs_inode_has_valid_blocks(inode) &&
1391                     (rfs->bmap || pb.is_dir)) {
1392                         pb.ino = ino;
1393                         retval = ext2fs_block_iterate2(rfs->old_fs,
1394                                                        ino, 0, block_buf,
1395                                                        process_block, &pb);
1396                         if (retval)
1397                                 goto errout;
1398                         if (pb.error) {
1399                                 retval = pb.error;
1400                                 goto errout;
1401                         }
1402                 }
1403
1404                 if (ino <= start_to_move)
1405                         continue; /* Don't need to move it. */
1406
1407                 /*
1408                  * Find a new inode
1409                  */
1410                 retval = ext2fs_new_inode(rfs->new_fs, 0, 0, 0, &new_inode);
1411                 if (retval)
1412                         goto errout;
1413
1414                 ext2fs_inode_alloc_stats2(rfs->new_fs, new_inode, +1,
1415                                           pb.is_dir);
1416                 if (pb.changed) {
1417                         /* Get the new version of the inode */
1418                         retval = ext2fs_read_inode_full(rfs->old_fs, ino,
1419                                                 inode, inode_size);
1420                         if (retval) goto errout;
1421                 }
1422                 inode->i_ctime = time(0);
1423                 retval = ext2fs_write_inode_full(rfs->old_fs, new_inode,
1424                                                 inode, inode_size);
1425                 if (retval) goto errout;
1426
1427 #ifdef RESIZE2FS_DEBUG
1428                 if (rfs->flags & RESIZE_DEBUG_INODEMAP)
1429                         printf("Inode moved %u->%u\n", ino, new_inode);
1430 #endif
1431                 if (!rfs->imap) {
1432                         retval = ext2fs_create_extent_table(&rfs->imap, 0);
1433                         if (retval)
1434                                 goto errout;
1435                 }
1436                 ext2fs_add_extent_entry(rfs->imap, ino, new_inode);
1437         }
1438         io_channel_flush(rfs->old_fs->io);
1439
1440 errout:
1441         ext2fs_blocks_count_set(rfs->old_fs->super, orig_size);
1442         if (rfs->bmap) {
1443                 ext2fs_free_extent_table(rfs->bmap);
1444                 rfs->bmap = 0;
1445         }
1446         if (scan)
1447                 ext2fs_close_inode_scan(scan);
1448         if (block_buf)
1449                 ext2fs_free_mem(&block_buf);
1450         free(inode);
1451         return retval;
1452 }
1453
1454 /* --------------------------------------------------------------------
1455  *
1456  * Resize processing, phase 4.
1457  *
1458  * --------------------------------------------------------------------
1459  */
1460
1461 struct istruct {
1462         ext2_resize_t rfs;
1463         errcode_t       err;
1464         unsigned int    max_dirs;
1465         unsigned int    num;
1466 };
1467
1468 static int check_and_change_inodes(ext2_ino_t dir,
1469                                    int entry EXT2FS_ATTR((unused)),
1470                                    struct ext2_dir_entry *dirent, int offset,
1471                                    int  blocksize EXT2FS_ATTR((unused)),
1472                                    char *buf EXT2FS_ATTR((unused)),
1473                                    void *priv_data)
1474 {
1475         struct istruct *is = (struct istruct *) priv_data;
1476         struct ext2_inode       inode;
1477         ext2_ino_t              new_inode;
1478         errcode_t               retval;
1479
1480         if (is->rfs->progress && offset == 0) {
1481                 io_channel_flush(is->rfs->old_fs->io);
1482                 is->err = (is->rfs->progress)(is->rfs,
1483                                               E2_RSZ_INODE_REF_UPD_PASS,
1484                                               ++is->num, is->max_dirs);
1485                 if (is->err)
1486                         return DIRENT_ABORT;
1487         }
1488
1489         if (!dirent->inode)
1490                 return 0;
1491
1492         new_inode = ext2fs_extent_translate(is->rfs->imap, dirent->inode);
1493
1494         if (!new_inode)
1495                 return 0;
1496 #ifdef RESIZE2FS_DEBUG
1497         if (is->rfs->flags & RESIZE_DEBUG_INODEMAP)
1498                 printf("Inode translate (dir=%u, name=%.*s, %u->%u)\n",
1499                        dir, dirent->name_len&0xFF, dirent->name,
1500                        dirent->inode, new_inode);
1501 #endif
1502
1503         dirent->inode = new_inode;
1504
1505         /* Update the directory mtime and ctime */
1506         retval = ext2fs_read_inode(is->rfs->old_fs, dir, &inode);
1507         if (retval == 0) {
1508                 inode.i_mtime = inode.i_ctime = time(0);
1509                 is->err = ext2fs_write_inode(is->rfs->old_fs, dir, &inode);
1510                 if (is->err)
1511                         return DIRENT_ABORT;
1512         }
1513
1514         return DIRENT_CHANGED;
1515 }
1516
1517 static errcode_t inode_ref_fix(ext2_resize_t rfs)
1518 {
1519         errcode_t               retval;
1520         struct istruct          is;
1521
1522         if (!rfs->imap)
1523                 return 0;
1524
1525         /*
1526          * Now, we iterate over all of the directories to update the
1527          * inode references
1528          */
1529         is.num = 0;
1530         is.max_dirs = ext2fs_dblist_count(rfs->old_fs->dblist);
1531         is.rfs = rfs;
1532         is.err = 0;
1533
1534         if (rfs->progress) {
1535                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS,
1536                                          0, is.max_dirs);
1537                 if (retval)
1538                         goto errout;
1539         }
1540
1541         retval = ext2fs_dblist_dir_iterate(rfs->old_fs->dblist,
1542                                            DIRENT_FLAG_INCLUDE_EMPTY, 0,
1543                                            check_and_change_inodes, &is);
1544         if (retval)
1545                 goto errout;
1546         if (is.err) {
1547                 retval = is.err;
1548                 goto errout;
1549         }
1550
1551         if (rfs->progress && (is.num < is.max_dirs))
1552                 (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS,
1553                                 is.max_dirs, is.max_dirs);
1554
1555 errout:
1556         ext2fs_free_extent_table(rfs->imap);
1557         rfs->imap = 0;
1558         return retval;
1559 }
1560
1561
1562 /* --------------------------------------------------------------------
1563  *
1564  * Resize processing, phase 5.
1565  *
1566  * In this phase we actually move the inode table around, and then
1567  * update the summary statistics.  This is scary, since aborting here
1568  * will potentially scramble the filesystem.  (We are moving the
1569  * inode tables around in place, and so the potential for lost data,
1570  * or at the very least scrambling the mapping between filenames and
1571  * inode numbers is very high in case of a power failure here.)
1572  * --------------------------------------------------------------------
1573  */
1574
1575
1576 /*
1577  * A very scary routine --- this one moves the inode table around!!!
1578  *
1579  * After this you have to use the rfs->new_fs file handle to read and
1580  * write inodes.
1581  */
1582 static errcode_t move_itables(ext2_resize_t rfs)
1583 {
1584         int             n, num, size, diff;
1585         dgrp_t          i, max_groups;
1586         ext2_filsys     fs = rfs->new_fs;
1587         char            *cp;
1588         blk_t           old_blk, new_blk, blk;
1589         errcode_t       retval;
1590         int             j, to_move, moved;
1591
1592         max_groups = fs->group_desc_count;
1593         if (max_groups > rfs->old_fs->group_desc_count)
1594                 max_groups = rfs->old_fs->group_desc_count;
1595
1596         size = fs->blocksize * fs->inode_blocks_per_group;
1597         if (!rfs->itable_buf) {
1598                 retval = ext2fs_get_mem(size, &rfs->itable_buf);
1599                 if (retval)
1600                         return retval;
1601         }
1602
1603         /*
1604          * Figure out how many inode tables we need to move
1605          */
1606         to_move = moved = 0;
1607         for (i=0; i < max_groups; i++)
1608                 if (ext2fs_inode_table_loc(rfs->old_fs, i) !=
1609                     ext2fs_inode_table_loc(fs, i))
1610                         to_move++;
1611
1612         if (to_move == 0)
1613                 return 0;
1614
1615         if (rfs->progress) {
1616                 retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
1617                                        0, to_move);
1618                 if (retval)
1619                         goto errout;
1620         }
1621
1622         rfs->old_fs->flags |= EXT2_FLAG_MASTER_SB_ONLY;
1623
1624         for (i=0; i < max_groups; i++) {
1625                 old_blk = ext2fs_inode_table_loc(rfs->old_fs, i);
1626                 new_blk = ext2fs_inode_table_loc(fs, i);
1627                 diff = new_blk - old_blk;
1628
1629 #ifdef RESIZE2FS_DEBUG
1630                 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1631                         printf("Itable move group %d block %u->%u (diff %d)\n",
1632                                i, old_blk, new_blk, diff);
1633 #endif
1634
1635                 if (!diff)
1636                         continue;
1637
1638                 retval = io_channel_read_blk64(fs->io, old_blk,
1639                                                fs->inode_blocks_per_group,
1640                                                rfs->itable_buf);
1641                 if (retval)
1642                         goto errout;
1643                 /*
1644                  * The end of the inode table segment often contains
1645                  * all zeros, and we're often only moving the inode
1646                  * table down a block or two.  If so, we can optimize
1647                  * things by not rewriting blocks that we know to be zero
1648                  * already.
1649                  */
1650                 for (cp = rfs->itable_buf+size-1, n=0; n < size; n++, cp--)
1651                         if (*cp)
1652                                 break;
1653                 n = n >> EXT2_BLOCK_SIZE_BITS(fs->super);
1654 #ifdef RESIZE2FS_DEBUG
1655                 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1656                         printf("%d blocks of zeros...\n", n);
1657 #endif
1658                 num = fs->inode_blocks_per_group;
1659                 if (n > diff)
1660                         num -= n;
1661
1662                 retval = io_channel_write_blk64(fs->io, new_blk,
1663                                                 num, rfs->itable_buf);
1664                 if (retval) {
1665                         io_channel_write_blk64(fs->io, old_blk,
1666                                                num, rfs->itable_buf);
1667                         goto errout;
1668                 }
1669                 if (n > diff) {
1670                         retval = io_channel_write_blk64(fs->io,
1671                               old_blk + fs->inode_blocks_per_group,
1672                               diff, (rfs->itable_buf +
1673                                      (fs->inode_blocks_per_group - diff) *
1674                                      fs->blocksize));
1675                         if (retval)
1676                                 goto errout;
1677                 }
1678
1679                 for (blk = ext2fs_inode_table_loc(rfs->old_fs, i), j=0;
1680                      j < fs->inode_blocks_per_group ; j++, blk++)
1681                         ext2fs_block_alloc_stats2(fs, blk, -1);
1682
1683                 ext2fs_inode_table_loc_set(rfs->old_fs, i, new_blk);
1684                 ext2fs_group_desc_csum_set(rfs->old_fs, i);
1685                 ext2fs_mark_super_dirty(rfs->old_fs);
1686                 ext2fs_flush(rfs->old_fs);
1687
1688                 if (rfs->progress) {
1689                         retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
1690                                                ++moved, to_move);
1691                         if (retval)
1692                                 goto errout;
1693                 }
1694         }
1695         mark_table_blocks(fs, fs->block_map);
1696         ext2fs_flush(fs);
1697 #ifdef RESIZE2FS_DEBUG
1698         if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1699                 printf("Inode table move finished.\n");
1700 #endif
1701         return 0;
1702
1703 errout:
1704         return retval;
1705 }
1706
1707 /*
1708  * Fix the resize inode
1709  */
1710 static errcode_t fix_resize_inode(ext2_filsys fs)
1711 {
1712         struct ext2_inode       inode;
1713         errcode_t               retval;
1714         char *                  block_buf;
1715         blk_t                   blk;
1716
1717         if (!(fs->super->s_feature_compat &
1718               EXT2_FEATURE_COMPAT_RESIZE_INODE))
1719                 return 0;
1720
1721         retval = ext2fs_get_mem(fs->blocksize, &block_buf);
1722         if (retval) goto errout;
1723
1724         retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode);
1725         if (retval) goto errout;
1726
1727         if (fs->super->s_reserved_gdt_blocks == 0) {
1728                 fs->super->s_feature_compat &=
1729                         ~EXT2_FEATURE_COMPAT_RESIZE_INODE;
1730                 ext2fs_mark_super_dirty(fs);
1731
1732                 if ((blk = inode.i_block[EXT2_DIND_BLOCK]) != 0)
1733                         ext2fs_block_alloc_stats2(fs, blk, -1);
1734
1735                 memset(&inode, 0, sizeof(inode));
1736
1737                 retval = ext2fs_write_inode(fs, EXT2_RESIZE_INO, &inode);
1738                 goto errout;
1739         }
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         blk_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         blk_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_loc(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                         count = 0;
1823                         group_free = 0;
1824                         uninit = (ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT)
1825                                   );
1826                         ext2fs_super_and_bgd_loc(fs, group, &super_blk,
1827                                                  &old_desc_blk,
1828                                                  &new_desc_blk, 0);
1829                         if (fs->super->s_feature_incompat &
1830                             EXT2_FEATURE_INCOMPAT_META_BG)
1831                                 old_desc_blocks = fs->super->s_first_meta_bg;
1832                         else
1833                                 old_desc_blocks = fs->desc_blocks +
1834                                         fs->super->s_reserved_gdt_blocks;
1835                 }
1836         }
1837         ext2fs_free_blocks_count_set(fs->super, total_free);
1838
1839         /*
1840          * Next, calculate the inode statistics
1841          */
1842         group_free = 0;
1843         total_free = 0;
1844         count = 0;
1845         group = 0;
1846
1847         /* Protect loop from wrap-around if s_inodes_count maxed */
1848         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT);
1849         for (ino = 1; ino <= fs->super->s_inodes_count && ino > 0; ino++) {
1850                 if (uninit ||
1851                     !ext2fs_fast_test_inode_bitmap2(fs->inode_map, ino)) {
1852                         group_free++;
1853                         total_free++;
1854                 }
1855                 count++;
1856                 if ((count == fs->super->s_inodes_per_group) ||
1857                     (ino == fs->super->s_inodes_count)) {
1858                         ext2fs_bg_free_inodes_count_set(fs, group, group_free);
1859                         ext2fs_group_desc_csum_set(fs, group);
1860                         group++;
1861                         count = 0;
1862                         group_free = 0;
1863                         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT);
1864                 }
1865         }
1866         fs->super->s_free_inodes_count = total_free;
1867         ext2fs_mark_super_dirty(fs);
1868         return 0;
1869 }
1870
1871 /*
1872  *  Journal may have been relocated; update the backup journal blocks
1873  *  in the superblock.
1874  */
1875 static errcode_t fix_sb_journal_backup(ext2_filsys fs)
1876 {
1877         errcode_t         retval;
1878         struct ext2_inode inode;
1879
1880         if (!(fs->super->s_feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1881                 return 0;
1882
1883         retval = ext2fs_read_inode(fs, fs->super->s_journal_inum, &inode);
1884         if (retval)
1885                 return retval;
1886         memcpy(fs->super->s_jnl_blocks, inode.i_block, EXT2_N_BLOCKS*4);
1887         fs->super->s_jnl_blocks[16] = inode.i_size;
1888         fs->super->s_jnl_backup_type = EXT3_JNL_BACKUP_BLOCKS;
1889         ext2fs_mark_super_dirty(fs);
1890         return 0;
1891 }
1892
1893 /*
1894  * calcluate the minimum number of blocks the given fs can be resized to
1895  */
1896 blk_t calculate_minimum_resize_size(ext2_filsys fs)
1897 {
1898         blk_t inode_count, blks_needed, groups, data_blocks;
1899         blk_t grp, data_needed, last_start;
1900         int overhead = 0, num_of_superblocks = 0;
1901         int extra_groups = 0;
1902         int flexbg_size = 1 << fs->super->s_log_groups_per_flex;
1903
1904         /*
1905          * first figure out how many group descriptors we need to
1906          * handle the number of inodes we have
1907          */
1908         inode_count = fs->super->s_inodes_count -
1909                 fs->super->s_free_inodes_count;
1910         blks_needed = ext2fs_div_ceil(inode_count,
1911                                       fs->super->s_inodes_per_group) *
1912                 EXT2_BLOCKS_PER_GROUP(fs->super);
1913         groups = ext2fs_div_ceil(blks_needed,
1914                                  EXT2_BLOCKS_PER_GROUP(fs->super));
1915
1916         /*
1917          * we need to figure out how many backup superblocks we have so we can
1918          * account for that in the metadata
1919          */
1920         for (grp = 0; grp < fs->group_desc_count; grp++) {
1921                 if (ext2fs_bg_has_super(fs, grp))
1922                         num_of_superblocks++;
1923         }
1924
1925         /* calculate how many blocks are needed for data */
1926         data_needed = ext2fs_blocks_count(fs->super) -
1927                 ext2fs_free_blocks_count(fs->super);
1928         data_needed -= SUPER_OVERHEAD(fs) * num_of_superblocks;
1929         data_needed -= META_OVERHEAD(fs) * fs->group_desc_count;
1930
1931         if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_FLEX_BG) {
1932                 /*
1933                  * For ext4 we need to allow for up to a flex_bg worth
1934                  * of inode tables of slack space so the resize
1935                  * operation can be guaranteed to finish.
1936                  */
1937                 extra_groups = flexbg_size - (groups & (flexbg_size - 1));
1938                 data_needed += META_OVERHEAD(fs) * extra_groups;
1939                 extra_groups = groups % flexbg_size;
1940         }
1941
1942         /*
1943          * figure out how many data blocks we have given the number of groups
1944          * we need for our inodes
1945          */
1946         data_blocks = groups * EXT2_BLOCKS_PER_GROUP(fs->super);
1947         last_start = 0;
1948         for (grp = 0; grp < groups; grp++) {
1949                 overhead = META_OVERHEAD(fs);
1950
1951                 if (ext2fs_bg_has_super(fs, grp))
1952                         overhead += SUPER_OVERHEAD(fs);
1953
1954                 /*
1955                  * we want to keep track of how much data we can store in
1956                  * the groups leading up to the last group so we can determine
1957                  * how big the last group needs to be
1958                  */
1959                 if (grp != (groups - 1))
1960                         last_start += EXT2_BLOCKS_PER_GROUP(fs->super) -
1961                                 overhead;
1962
1963                 data_blocks -= overhead;
1964         }
1965
1966         /*
1967          * if we need more group descriptors in order to accomodate our data
1968          * then we need to add them here
1969          */
1970         while (data_needed > data_blocks) {
1971                 blk_t remainder = data_needed - data_blocks;
1972                 blk_t extra_grps;
1973
1974                 /* figure out how many more groups we need for the data */
1975                 extra_grps = ext2fs_div_ceil(remainder,
1976                                              EXT2_BLOCKS_PER_GROUP(fs->super));
1977
1978                 data_blocks += extra_grps * EXT2_BLOCKS_PER_GROUP(fs->super);
1979
1980                 /* ok we have to account for the last group */
1981                 overhead = META_OVERHEAD(fs);
1982                 if (ext2fs_bg_has_super(fs, groups-1))
1983                         overhead += SUPER_OVERHEAD(fs);
1984                 last_start += EXT2_BLOCKS_PER_GROUP(fs->super) - overhead;
1985
1986                 for (grp = groups; grp < groups+extra_grps; grp++) {
1987                         overhead = META_OVERHEAD(fs);
1988                         if (ext2fs_bg_has_super(fs, grp))
1989                                 overhead += SUPER_OVERHEAD(fs);
1990
1991                         /*
1992                          * again, we need to see how much data we cram into
1993                          * all of the groups leading up to the last group
1994                          */
1995                         if (grp != (groups + extra_grps - 1))
1996                                 last_start += EXT2_BLOCKS_PER_GROUP(fs->super)
1997                                         - overhead;
1998
1999                         data_blocks -= overhead;
2000                 }
2001
2002                 groups += extra_grps;
2003                 extra_groups += extra_grps;
2004                 if (fs->super->s_feature_incompat
2005                         & EXT4_FEATURE_INCOMPAT_FLEX_BG
2006                     && extra_groups > flexbg_size) {
2007                         /*
2008                          * For ext4 we need to allow for up to a flex_bg worth
2009                          * of inode tables of slack space so the resize
2010                          * operation can be guaranteed to finish.
2011                          */
2012                         extra_groups = flexbg_size -
2013                                                 (groups & (flexbg_size - 1));
2014                         data_needed += META_OVERHEAD(fs) * extra_groups;
2015                         extra_groups = groups % flexbg_size;
2016                 }
2017         }
2018
2019         /* now for the fun voodoo */
2020         overhead = META_OVERHEAD(fs);
2021
2022         /*
2023          * if this is the case then the last group is going to have data in it
2024          * so we need to adjust the size of the last group accordingly
2025          */
2026         if (last_start < data_needed) {
2027                 blk_t remainder = data_needed - last_start;
2028
2029                 /*
2030                  * 50 is a magic number that mkfs/resize uses to see if its
2031                  * even worth making/resizing the fs.  basically you need to
2032                  * have at least 50 blocks in addition to the blocks needed
2033                  * for the metadata in the last group
2034                  */
2035                 if (remainder > 50)
2036                         overhead += remainder;
2037                 else
2038                         overhead += 50;
2039         } else
2040                 overhead += 50;
2041
2042         if (ext2fs_bg_has_super(fs, groups-1))
2043                 overhead += SUPER_OVERHEAD(fs);
2044
2045         /*
2046          * since our last group doesn't have to be BLOCKS_PER_GROUP large, we
2047          * only do groups-1, and then add the number of blocks needed to
2048          * handle the group descriptor metadata+data that we need
2049          */
2050         blks_needed = (groups-1) * EXT2_BLOCKS_PER_GROUP(fs->super);
2051         blks_needed += overhead;
2052
2053         /*
2054          * If at this point we've already added up more "needed" than
2055          * the current size, just return current size as minimum.
2056          */
2057         if (blks_needed >= ext2fs_blocks_count(fs->super))
2058                 return ext2fs_blocks_count(fs->super);
2059         /*
2060          * We need to reserve a few extra blocks if extents are
2061          * enabled, in case we need to grow the extent tree.  The more
2062          * we shrink the file system, the more space we need.
2063          */
2064         if (fs->super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_EXTENTS)
2065                 blks_needed += (ext2fs_blocks_count(fs->super) -
2066                                 blks_needed)/500;
2067
2068         return blks_needed;
2069 }