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 FS_BLOCK_BM(fs, i) ((fs)->group_desc[(i)].bg_block_bitmap)
  58 #define FS_INODE_BM(fs, i) ((fs)->group_desc[(i)].bg_inode_bitmap)
  59 #define FS_INODE_TB(fs, i) ((fs)->group_desc[(i)].bg_inode_table)
  60
  61 #define IS_BLOCK_BM(fs, i, blk) ((blk) == FS_BLOCK_BM((fs),(i)))
  62 #define IS_INODE_BM(fs, i, blk) ((blk) == FS_INODE_BM((fs),(i)))
  63
  64 #define IS_INODE_TB(fs, i, blk) (((blk) >= FS_INODE_TB((fs), (i))) && \
  65                                  ((blk) < (FS_INODE_TB((fs), (i)) + \
  66                                            (fs)->inode_blocks_per_group)))
  67
  68 #define META_OVERHEAD(fs) (2 + (fs)->inode_blocks_per_group)
  69 #define SUPER_OVERHEAD(fs) (1 + (fs)->desc_blocks +\
  70                             (fs)->super->s_reserved_gdt_blocks)
  71
  72 /*
  73  * This is the top-level routine which does the dirty deed....
  74  */
  75 errcode_t resize_fs(ext2_filsys fs, blk_t *new_size, int flags,
  76                     errcode_t (*progress)(ext2_resize_t rfs, int pass,
  77                                           unsigned long cur,
  78                                           unsigned long max_val))
  79 {
  80         ext2_resize_t   rfs;
  81         errcode_t       retval;
  82
  83         retval = ext2fs_read_bitmaps(fs);
  84         if (retval)
  85                 return retval;
  86
  87         fs->super->s_state |= EXT2_ERROR_FS;
  88         ext2fs_mark_super_dirty(fs);
  89         ext2fs_flush(fs);
  90
  91         /*
  92          * Create the data structure
  93          */
  94         retval = ext2fs_get_mem(sizeof(struct ext2_resize_struct), &rfs);
  95         if (retval)
  96                 return retval;
  97         memset(rfs, 0, sizeof(struct ext2_resize_struct));
  98
  99         fix_uninit_block_bitmaps(fs);
 100         fs->priv_data = rfs;
 101         rfs->old_fs = fs;
 102         rfs->flags = flags;
 103         rfs->itable_buf  = 0;
 104         rfs->progress = progress;
 105         retval = ext2fs_dup_handle(fs, &rfs->new_fs);
 106         if (retval)
 107                 goto errout;
 108
 109         retval = adjust_superblock(rfs, *new_size);
 110         if (retval)
 111                 goto errout;
 112
 113         fix_uninit_block_bitmaps(rfs->new_fs);
 114         /* Clear the block bitmap uninit flag for the last block group */
 115         rfs->new_fs->group_desc[rfs->new_fs->group_desc_count-1].bg_flags &=
 116                 ~EXT2_BG_BLOCK_UNINIT;
 117
 118         *new_size = rfs->new_fs->super->s_blocks_count;
 119
 120         retval = blocks_to_move(rfs);
 121         if (retval)
 122                 goto errout;
 123
 124 #ifdef RESIZE2FS_DEBUG
 125         if (rfs->flags & RESIZE_DEBUG_BMOVE)
 126                 printf("Number of free blocks: %u/%u, Needed: %d\n",
 127                        rfs->old_fs->super->s_free_blocks_count,
 128                        rfs->new_fs->super->s_free_blocks_count,
 129                        rfs->needed_blocks);
 130 #endif
 131
 132         retval = block_mover(rfs);
 133         if (retval)
 134                 goto errout;
 135
 136         retval = inode_scan_and_fix(rfs);
 137         if (retval)
 138                 goto errout;
 139
 140         retval = inode_ref_fix(rfs);
 141         if (retval)
 142                 goto errout;
 143
 144         retval = move_itables(rfs);
 145         if (retval)
 146                 goto errout;
 147
 148         retval = ext2fs_calculate_summary_stats(rfs->new_fs);
 149         if (retval)
 150                 goto errout;
 151
 152         retval = fix_resize_inode(rfs->new_fs);
 153         if (retval)
 154                 goto errout;
 155
 156         retval = fix_sb_journal_backup(rfs->new_fs);
 157         if (retval)
 158                 goto errout;
 159
 160         rfs->new_fs->super->s_state &= ~EXT2_ERROR_FS;
 161         rfs->new_fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
 162         retval = ext2fs_close(rfs->new_fs);
 163         if (retval)
 164                 goto errout;
 165
 166         rfs->flags = flags;
 167
 168         ext2fs_free(rfs->old_fs);
 169         if (rfs->itable_buf)
 170                 ext2fs_free_mem(&rfs->itable_buf);
 171         if (rfs->reserve_blocks)
 172                 ext2fs_free_block_bitmap(rfs->reserve_blocks);
 173         if (rfs->move_blocks)
 174                 ext2fs_free_block_bitmap(rfs->move_blocks);
 175         ext2fs_free_mem(&rfs);
 176
 177         return 0;
 178
 179 errout:
 180         if (rfs->new_fs)
 181                 ext2fs_free(rfs->new_fs);
 182         if (rfs->itable_buf)
 183                 ext2fs_free_mem(&rfs->itable_buf);
 184         ext2fs_free_mem(&rfs);
 185         return retval;
 186 }
 187
 188 /*
 189  * Clean up the bitmaps for unitialized bitmaps
 190  */
 191 static void fix_uninit_block_bitmaps(ext2_filsys fs)
 192 {
 193         blk_t           i, blk, super_blk, old_desc_blk, new_desc_blk;
 194         int             old_desc_blocks;
 195         dgrp_t          g;
 196
 197         if (!(EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 198                                          EXT4_FEATURE_RO_COMPAT_GDT_CSUM)))
 199                 return;
 200
 201         for (g=0; g < fs->group_desc_count; g++) {
 202                 if (!(fs->group_desc[g].bg_flags & EXT2_BG_BLOCK_UNINIT))
 203                         continue;
 204
 205                 blk = (g * fs->super->s_blocks_per_group) +
 206                         fs->super->s_first_data_block;
 207
 208                 ext2fs_super_and_bgd_loc(fs, g, &super_blk,
 209                                          &old_desc_blk, &new_desc_blk, 0);
 210
 211                 if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
 212                         old_desc_blocks = fs->super->s_first_meta_bg;
 213                 else
 214                         old_desc_blocks = fs->desc_blocks +
 215                                 fs->super->s_reserved_gdt_blocks;
 216
 217                 for (i=0; i < fs->super->s_blocks_per_group; i++, blk++) {
 218                         if (blk >= fs->super->s_blocks_count)
 219                                 break;
 220                         if ((blk == super_blk) ||
 221                             (old_desc_blk && old_desc_blocks &&
 222                              (blk >= old_desc_blk) &&
 223                              (blk < old_desc_blk + old_desc_blocks)) ||
 224                             (new_desc_blk && (blk == new_desc_blk)) ||
 225                             (blk == fs->group_desc[g].bg_block_bitmap) ||
 226                             (blk == fs->group_desc[g].bg_inode_bitmap) ||
 227                             (blk >= fs->group_desc[g].bg_inode_table &&
 228                              (blk < fs->group_desc[g].bg_inode_table
 229                               + fs->inode_blocks_per_group)))
 230                                 ext2fs_fast_mark_block_bitmap(fs->block_map, blk);
 231                         else
 232                                 ext2fs_fast_unmark_block_bitmap(fs->block_map, blk);
 233                 }
 234         }
 235 }
 236
 237 /* --------------------------------------------------------------------
 238  *
 239  * Resize processing, phase 1.
 240  *
 241  * In this phase we adjust the in-memory superblock information, and
 242  * initialize any new parts of the inode table.  The new parts of the
 243  * inode table are created in virgin disk space, so we can abort here
 244  * without any side effects.
 245  * --------------------------------------------------------------------
 246  */
 247
 248 /*
 249  * If the group descriptor's bitmap and inode table blocks are valid,
 250  * release them in the new filesystem data structure, and mark them as
 251  * reserved so the old inode table blocks don't get overwritten.
 252  */
 253 static void free_gdp_blocks(ext2_filsys fs,
 254                             ext2fs_block_bitmap reserve_blocks,
 255                             struct ext2_group_desc *gdp)
 256 {
 257         blk_t   blk;
 258         int     j;
 259
 260         if (gdp->bg_block_bitmap &&
 261             (gdp->bg_block_bitmap < fs->super->s_blocks_count)) {
 262                 ext2fs_block_alloc_stats(fs, gdp->bg_block_bitmap, -1);
 263                 ext2fs_mark_block_bitmap(reserve_blocks,
 264                                          gdp->bg_block_bitmap);
 265         }
 266
 267         if (gdp->bg_inode_bitmap &&
 268             (gdp->bg_inode_bitmap < fs->super->s_blocks_count)) {
 269                 ext2fs_block_alloc_stats(fs, gdp->bg_inode_bitmap, -1);
 270                 ext2fs_mark_block_bitmap(reserve_blocks,
 271                                          gdp->bg_inode_bitmap);
 272         }
 273
 274         if (gdp->bg_inode_table == 0 ||
 275             (gdp->bg_inode_table >= fs->super->s_blocks_count))
 276                 return;
 277
 278         for (blk = gdp->bg_inode_table, j = 0;
 279              j < fs->inode_blocks_per_group; j++, blk++) {
 280                 if (blk >= fs->super->s_blocks_count)
 281                         break;
 282                 ext2fs_block_alloc_stats(fs, blk, -1);
 283                 ext2fs_mark_block_bitmap(reserve_blocks, blk);
 284         }
 285 }
 286
 287 /*
 288  * This routine is shared by the online and offline resize routines.
 289  * All of the information which is adjusted in memory is done here.
 290  *
 291  * The reserve_blocks parameter is only needed when shrinking the
 292  * filesystem.
 293  */
 294 errcode_t adjust_fs_info(ext2_filsys fs, ext2_filsys old_fs,
 295                          ext2fs_block_bitmap reserve_blocks, blk_t new_size)
 296 {
 297         errcode_t       retval;
 298         int             overhead = 0;
 299         int             rem;
 300         blk_t           blk, group_block;
 301         ext2_ino_t      real_end;
 302         int             adj, old_numblocks, numblocks, adjblocks;
 303         unsigned long   i, j, old_desc_blocks, max_group;
 304         unsigned int    meta_bg, meta_bg_size;
 305         int             has_super, csum_flag;
 306         unsigned long long new_inodes;  /* u64 to check for overflow */
 307         double          percent;
 308
 309         fs->super->s_blocks_count = new_size;
 310
 311 retry:
 312         fs->group_desc_count = ext2fs_div_ceil(fs->super->s_blocks_count -
 313                                        fs->super->s_first_data_block,
 314                                        EXT2_BLOCKS_PER_GROUP(fs->super));
 315         if (fs->group_desc_count == 0)
 316                 return EXT2_ET_TOOSMALL;
 317         fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count,
 318                                           EXT2_DESC_PER_BLOCK(fs->super));
 319
 320         /*
 321          * Overhead is the number of bookkeeping blocks per group.  It
 322          * includes the superblock backup, the group descriptor
 323          * backups, the inode bitmap, the block bitmap, and the inode
 324          * table.
 325          */
 326         overhead = (int) (2 + fs->inode_blocks_per_group);
 327
 328         if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1))
 329                 overhead += 1 + fs->desc_blocks +
 330                         fs->super->s_reserved_gdt_blocks;
 331
 332         /*
 333          * See if the last group is big enough to support the
 334          * necessary data structures.  If not, we need to get rid of
 335          * it.
 336          */
 337         rem = (fs->super->s_blocks_count - fs->super->s_first_data_block) %
 338                 fs->super->s_blocks_per_group;
 339         if ((fs->group_desc_count == 1) && rem && (rem < overhead))
 340                 return EXT2_ET_TOOSMALL;
 341         if (rem && (rem < overhead+50)) {
 342                 fs->super->s_blocks_count -= rem;
 343                 goto retry;
 344         }
 345         /*
 346          * Adjust the number of inodes
 347          */
 348         new_inodes =(unsigned long long) fs->super->s_inodes_per_group * fs->group_desc_count;
 349         if (new_inodes > ~0U) {
 350                 fprintf(stderr, _("inodes (%llu) must be less than %u"),
 351                                    new_inodes, ~0U);
 352                 return EXT2_ET_TOO_MANY_INODES;
 353         }
 354         fs->super->s_inodes_count = fs->super->s_inodes_per_group *
 355                 fs->group_desc_count;
 356
 357         /*
 358          * Adjust the number of free blocks
 359          */
 360         blk = old_fs->super->s_blocks_count;
 361         if (blk > fs->super->s_blocks_count)
 362                 fs->super->s_free_blocks_count -=
 363                         (blk - fs->super->s_blocks_count);
 364         else
 365                 fs->super->s_free_blocks_count +=
 366                         (fs->super->s_blocks_count - blk);
 367
 368         /*
 369          * Adjust the number of reserved blocks
 370          */
 371         percent = (old_fs->super->s_r_blocks_count * 100.0) /
 372                 old_fs->super->s_blocks_count;
 373         fs->super->s_r_blocks_count = (unsigned int) (percent *
 374                                         fs->super->s_blocks_count / 100.0);
 375
 376         /*
 377          * Adjust the bitmaps for size
 378          */
 379         retval = ext2fs_resize_inode_bitmap(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_bitmap(fs->super->s_blocks_count-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                                         &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 = (old_fs->super->s_blocks_count -
 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 = (fs->super->s_blocks_count -
 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         fs->group_desc[i].bg_free_blocks_count += (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         adj = old_fs->group_desc_count;
 486         max_group = fs->group_desc_count - adj;
 487         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
 488                 old_desc_blocks = fs->super->s_first_meta_bg;
 489         else
 490                 old_desc_blocks = fs->desc_blocks +
 491                         fs->super->s_reserved_gdt_blocks;
 492         for (i = old_fs->group_desc_count;
 493              i < fs->group_desc_count; i++) {
 494                 memset(&fs->group_desc[i], 0,
 495                        sizeof(struct ext2_group_desc));
 496                 adjblocks = 0;
 497
 498                 fs->group_desc[i].bg_flags = 0;
 499                 if (csum_flag)
 500                         fs->group_desc[i].bg_flags |= EXT2_BG_INODE_UNINIT |
 501                                 EXT2_BG_INODE_ZEROED;
 502                 if (i == fs->group_desc_count-1) {
 503                         numblocks = (fs->super->s_blocks_count -
 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                                 fs->group_desc[i].bg_flags |=
 512                                         EXT2_BG_BLOCK_UNINIT;
 513                 }
 514
 515                 has_super = ext2fs_bg_has_super(fs, i);
 516                 if (has_super) {
 517                         ext2fs_block_alloc_stats(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_stats(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_stats(fs,
 538                                                  group_block + has_super, +1);
 539                 }
 540
 541                 adjblocks += 2 + fs->inode_blocks_per_group;
 542
 543                 numblocks -= adjblocks;
 544                 fs->super->s_free_blocks_count -= adjblocks;
 545                 fs->super->s_free_inodes_count +=
 546                         fs->super->s_inodes_per_group;
 547                 fs->group_desc[i].bg_free_blocks_count = numblocks;
 548                 fs->group_desc[i].bg_free_inodes_count =
 549                         fs->super->s_inodes_per_group;
 550                 fs->group_desc[i].bg_used_dirs_count = 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, blk_t new_size)
 569 {
 570         ext2_filsys fs;
 571         int             adj = 0;
 572         errcode_t       retval;
 573         blk_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          * Initialize the new block group descriptors
 622          */
 623         retval = ext2fs_get_array(fs->blocksize, fs->inode_blocks_per_group,
 624                                 &rfs->itable_buf);
 625         if (retval)
 626                 goto errout;
 627
 628         memset(rfs->itable_buf, 0, fs->blocksize * fs->inode_blocks_per_group);
 629         group_block = fs->super->s_first_data_block +
 630                 rfs->old_fs->group_desc_count * fs->super->s_blocks_per_group;
 631
 632         adj = rfs->old_fs->group_desc_count;
 633         max_group = fs->group_desc_count - adj;
 634         if (rfs->progress) {
 635                 retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
 636                                        0, max_group);
 637                 if (retval)
 638                         goto errout;
 639         }
 640         for (i = rfs->old_fs->group_desc_count;
 641              i < fs->group_desc_count; i++) {
 642                 /*
 643                  * Write out the new inode table
 644                  */
 645                 retval = io_channel_write_blk(fs->io,
 646                                               fs->group_desc[i].bg_inode_table,
 647                                               fs->inode_blocks_per_group,
 648                                               rfs->itable_buf);
 649                 if (retval) goto errout;
 650
 651                 io_channel_flush(fs->io);
 652                 if (rfs->progress) {
 653                         retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
 654                                                i - adj + 1, max_group);
 655                         if (retval)
 656                                 goto errout;
 657                 }
 658                 group_block += fs->super->s_blocks_per_group;
 659         }
 660         io_channel_flush(fs->io);
 661         retval = 0;
 662
 663 errout:
 664         return retval;
 665 }
 666
 667 /* --------------------------------------------------------------------
 668  *
 669  * Resize processing, phase 2.
 670  *
 671  * In this phase we adjust determine which blocks need to be moved, in
 672  * blocks_to_move().  We then copy the blocks to their ultimate new
 673  * destinations using block_mover().  Since we are copying blocks to
 674  * their new locations, again during this pass we can abort without
 675  * any problems.
 676  * --------------------------------------------------------------------
 677  */
 678
 679 /*
 680  * This helper function creates a block bitmap with all of the
 681  * filesystem meta-data blocks.
 682  */
 683 static errcode_t mark_table_blocks(ext2_filsys fs,
 684                                    ext2fs_block_bitmap bmap)
 685 {
 686         blk_t                   b;
 687         unsigned int            j;
 688         dgrp_t                  i;
 689         unsigned long           meta_bg_size;
 690         unsigned int            old_desc_blocks;
 691
 692         meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
 693         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
 694                 old_desc_blocks = fs->super->s_first_meta_bg;
 695         else
 696                 old_desc_blocks = fs->desc_blocks +
 697                         fs->super->s_reserved_gdt_blocks;
 698         for (i = 0; i < fs->group_desc_count; i++) {
 699                 ext2fs_reserve_super_and_bgd(fs, i, bmap);
 700
 701                 /*
 702                  * Mark the blocks used for the inode table
 703                  */
 704                 for (j = 0, b = fs->group_desc[i].bg_inode_table;
 705                      j < (unsigned int) fs->inode_blocks_per_group;
 706                      j++, b++)
 707                         ext2fs_mark_block_bitmap(bmap, b);
 708
 709                 /*
 710                  * Mark block used for the block bitmap
 711                  */
 712                 ext2fs_mark_block_bitmap(bmap,
 713                                          fs->group_desc[i].bg_block_bitmap);
 714
 715                 /*
 716                  * Mark block used for the inode bitmap
 717                  */
 718                 ext2fs_mark_block_bitmap(bmap,
 719                                          fs->group_desc[i].bg_inode_bitmap);
 720         }
 721         return 0;
 722 }
 723
 724 /*
 725  * This function checks to see if a particular block (either a
 726  * superblock or a block group descriptor) overlaps with an inode or
 727  * block bitmap block, or with the inode table.
 728  */
 729 static void mark_fs_metablock(ext2_resize_t rfs,
 730                               ext2fs_block_bitmap meta_bmap,
 731                               int group, blk_t blk)
 732 {
 733         ext2_filsys     fs = rfs->new_fs;
 734
 735         ext2fs_mark_block_bitmap(rfs->reserve_blocks, blk);
 736         ext2fs_block_alloc_stats(fs, blk, +1);
 737
 738         /*
 739          * Check to see if we overlap with the inode or block bitmap,
 740          * or the inode tables.  If not, and the block is in use, then
 741          * mark it as a block to be moved.
 742          */
 743         if (IS_BLOCK_BM(fs, group, blk)) {
 744                 FS_BLOCK_BM(fs, group) = 0;
 745                 rfs->needed_blocks++;
 746         } else if (IS_INODE_BM(fs, group, blk)) {
 747                 FS_INODE_BM(fs, group) = 0;
 748                 rfs->needed_blocks++;
 749         } else if (IS_INODE_TB(fs, group, blk)) {
 750                 FS_INODE_TB(fs, group) = 0;
 751                 rfs->needed_blocks++;
 752         } else if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 753                                               EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
 754                    (fs->group_desc[group].bg_flags & EXT2_BG_BLOCK_UNINIT)) {
 755                 /*
 756                  * If the block bitmap is uninitialized, which means
 757                  * nothing other than standard metadata in use.
 758                  */
 759                 return;
 760         } else if (ext2fs_test_block_bitmap(rfs->old_fs->block_map, blk) &&
 761                    !ext2fs_test_block_bitmap(meta_bmap, blk)) {
 762                 ext2fs_mark_block_bitmap(rfs->move_blocks, blk);
 763                 rfs->needed_blocks++;
 764         }
 765 }
 766
 767
 768 /*
 769  * This routine marks and unmarks reserved blocks in the new block
 770  * bitmap.  It also determines which blocks need to be moved and
 771  * places this information into the move_blocks bitmap.
 772  */
 773 static errcode_t blocks_to_move(ext2_resize_t rfs)
 774 {
 775         int             j, has_super;
 776         dgrp_t          i, max_groups, g;
 777         blk_t           blk, group_blk;
 778         unsigned long   old_blocks, new_blocks;
 779         unsigned int    meta_bg, meta_bg_size;
 780         errcode_t       retval;
 781         ext2_filsys     fs, old_fs;
 782         ext2fs_block_bitmap     meta_bmap;
 783         __u32           save_incompat_flag;
 784
 785         fs = rfs->new_fs;
 786         old_fs = rfs->old_fs;
 787         if (old_fs->super->s_blocks_count > fs->super->s_blocks_count)
 788                 fs = rfs->old_fs;
 789
 790         retval = ext2fs_allocate_block_bitmap(fs, _("blocks to be moved"),
 791                                               &rfs->move_blocks);
 792         if (retval)
 793                 return retval;
 794
 795         retval = ext2fs_allocate_block_bitmap(fs, _("meta-data blocks"),
 796                                               &meta_bmap);
 797         if (retval)
 798                 return retval;
 799
 800         retval = mark_table_blocks(old_fs, meta_bmap);
 801         if (retval)
 802                 return retval;
 803
 804         fs = rfs->new_fs;
 805
 806         /*
 807          * If we're shrinking the filesystem, we need to move all of
 808          * the blocks that don't fit any more
 809          */
 810         for (blk = fs->super->s_blocks_count;
 811              blk < old_fs->super->s_blocks_count; blk++) {
 812                 g = ext2fs_group_of_blk(fs, blk);
 813                 if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 814                                                EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
 815                     (old_fs->group_desc[g].bg_flags & EXT2_BG_BLOCK_UNINIT)) {
 816                         /*
 817                          * The block bitmap is uninitialized, so skip
 818                          * to the next block group.
 819                          */
 820                         blk = ((g+1) * fs->super->s_blocks_per_group) +
 821                                 fs->super->s_first_data_block - 1;
 822                         continue;
 823                 }
 824                 if (ext2fs_test_block_bitmap(old_fs->block_map, blk) &&
 825                     !ext2fs_test_block_bitmap(meta_bmap, blk)) {
 826                         ext2fs_mark_block_bitmap(rfs->move_blocks, blk);
 827                         rfs->needed_blocks++;
 828                 }
 829                 ext2fs_mark_block_bitmap(rfs->reserve_blocks, blk);
 830         }
 831
 832         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) {
 833                 old_blocks = old_fs->super->s_first_meta_bg;
 834                 new_blocks = fs->super->s_first_meta_bg;
 835         } else {
 836                 old_blocks = old_fs->desc_blocks + old_fs->super->s_reserved_gdt_blocks;
 837                 new_blocks = fs->desc_blocks + fs->super->s_reserved_gdt_blocks;
 838         }
 839
 840         if (old_blocks == new_blocks) {
 841                 retval = 0;
 842                 goto errout;
 843         }
 844
 845         max_groups = fs->group_desc_count;
 846         if (max_groups > old_fs->group_desc_count)
 847                 max_groups = old_fs->group_desc_count;
 848         group_blk = old_fs->super->s_first_data_block;
 849         /*
 850          * If we're reducing the number of descriptor blocks, this
 851          * makes life easy.  :-)   We just have to mark some extra
 852          * blocks as free.
 853          */
 854         if (old_blocks > new_blocks) {
 855                 for (i = 0; i < max_groups; i++) {
 856                         if (!ext2fs_bg_has_super(fs, i)) {
 857                                 group_blk += fs->super->s_blocks_per_group;
 858                                 continue;
 859                         }
 860                         for (blk = group_blk+1+new_blocks;
 861                              blk < group_blk+1+old_blocks; blk++) {
 862                                 ext2fs_block_alloc_stats(fs, blk, -1);
 863                                 rfs->needed_blocks--;
 864                         }
 865                         group_blk += fs->super->s_blocks_per_group;
 866                 }
 867                 retval = 0;
 868                 goto errout;
 869         }
 870         /*
 871          * If we're increasing the number of descriptor blocks, life
 872          * gets interesting....
 873          */
 874         meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
 875         for (i = 0; i < max_groups; i++) {
 876                 has_super = ext2fs_bg_has_super(fs, i);
 877                 if (has_super)
 878                         mark_fs_metablock(rfs, meta_bmap, i, group_blk);
 879
 880                 meta_bg = i / meta_bg_size;
 881                 if (!(fs->super->s_feature_incompat &
 882                       EXT2_FEATURE_INCOMPAT_META_BG) ||
 883                     (meta_bg < fs->super->s_first_meta_bg)) {
 884                         if (has_super) {
 885                                 for (blk = group_blk+1;
 886                                      blk < group_blk + 1 + new_blocks; blk++)
 887                                         mark_fs_metablock(rfs, meta_bmap,
 888                                                           i, blk);
 889                         }
 890                 } else {
 891                         if (has_super)
 892                                 has_super = 1;
 893                         if (((i % meta_bg_size) == 0) ||
 894                             ((i % meta_bg_size) == 1) ||
 895                             ((i % meta_bg_size) == (meta_bg_size-1)))
 896                                 mark_fs_metablock(rfs, meta_bmap, i,
 897                                                   group_blk + has_super);
 898                 }
 899
 900                 if (fs->group_desc[i].bg_inode_table &&
 901                     fs->group_desc[i].bg_inode_bitmap &&
 902                     fs->group_desc[i].bg_block_bitmap)
 903                         goto next_group;
 904
 905                 /*
 906                  * Reserve the existing meta blocks that we know
 907                  * aren't to be moved.
 908                  */
 909                 if (fs->group_desc[i].bg_block_bitmap)
 910                         ext2fs_mark_block_bitmap(rfs->reserve_blocks,
 911                                  fs->group_desc[i].bg_block_bitmap);
 912                 if (fs->group_desc[i].bg_inode_bitmap)
 913                         ext2fs_mark_block_bitmap(rfs->reserve_blocks,
 914                                  fs->group_desc[i].bg_inode_bitmap);
 915                 if (fs->group_desc[i].bg_inode_table)
 916                         for (blk = fs->group_desc[i].bg_inode_table, j=0;
 917                              j < fs->inode_blocks_per_group ; j++, blk++)
 918                                 ext2fs_mark_block_bitmap(rfs->reserve_blocks,
 919                                                          blk);
 920
 921                 /*
 922                  * Allocate the missing data structures
 923                  *
 924                  * XXX We have a problem with FLEX_BG and off-line
 925                  * resizing where we are growing the size of the
 926                  * filesystem.  ext2fs_allocate_group_table() will try
 927                  * to reserve the inode table in the desired flex_bg
 928                  * location.  However, passing rfs->reserve_blocks
 929                  * doesn't work since it only has reserved the blocks
 930                  * that will be used in the new block group -- and
 931                  * with flex_bg, we can and will allocate the tables
 932                  * outside of the block group.  And we can't pass in
 933                  * the fs->block_map because it doesn't handle
 934                  * overlapping inode table movements right.  So for
 935                  * now, we temporarily disable flex_bg to force
 936                  * ext2fs_allocate_group_tables() to allocate the bg
 937                  * metadata in side the block group, and the restore
 938                  * it afterwards.  Ugly, until we can fix this up
 939                  * right later.
 940                  */
 941                 save_incompat_flag = fs->super->s_feature_incompat;
 942                 fs->super->s_feature_incompat &= ~EXT4_FEATURE_INCOMPAT_FLEX_BG;
 943                 retval = ext2fs_allocate_group_table(fs, i,
 944                                                      rfs->reserve_blocks);
 945                 fs->super->s_feature_incompat = save_incompat_flag;
 946                 if (retval)
 947                         goto errout;
 948
 949                 /*
 950                  * For those structures that have changed, we need to
 951                  * do bookkeepping.
 952                  */
 953                 if (FS_BLOCK_BM(old_fs, i) !=
 954                     (blk = FS_BLOCK_BM(fs, i))) {
 955                         ext2fs_block_alloc_stats(fs, blk, +1);
 956                         if (ext2fs_test_block_bitmap(old_fs->block_map, blk) &&
 957                             !ext2fs_test_block_bitmap(meta_bmap, blk))
 958                                 ext2fs_mark_block_bitmap(rfs->move_blocks,
 959                                                          blk);
 960                 }
 961                 if (FS_INODE_BM(old_fs, i) !=
 962                     (blk = FS_INODE_BM(fs, i))) {
 963                         ext2fs_block_alloc_stats(fs, blk, +1);
 964                         if (ext2fs_test_block_bitmap(old_fs->block_map, blk) &&
 965                             !ext2fs_test_block_bitmap(meta_bmap, blk))
 966                                 ext2fs_mark_block_bitmap(rfs->move_blocks,
 967                                                          blk);
 968                 }
 969
 970                 /*
 971                  * The inode table, if we need to relocate it, is
 972                  * handled specially.  We have to reserve the blocks
 973                  * for both the old and the new inode table, since we
 974                  * can't have the inode table be destroyed during the
 975                  * block relocation phase.
 976                  */
 977                 if (FS_INODE_TB(fs, i) == FS_INODE_TB(old_fs, i))
 978                         goto next_group; /* inode table not moved */
 979
 980                 rfs->needed_blocks += fs->inode_blocks_per_group;
 981
 982                 /*
 983                  * Mark the new inode table as in use in the new block
 984                  * allocation bitmap, and move any blocks that might
 985                  * be necessary.
 986                  */
 987                 for (blk = fs->group_desc[i].bg_inode_table, j=0;
 988                      j < fs->inode_blocks_per_group ; j++, blk++) {
 989                         ext2fs_block_alloc_stats(fs, blk, +1);
 990                         if (ext2fs_test_block_bitmap(old_fs->block_map, blk) &&
 991                             !ext2fs_test_block_bitmap(meta_bmap, blk))
 992                                 ext2fs_mark_block_bitmap(rfs->move_blocks,
 993                                                          blk);
 994                 }
 995
 996                 /*
 997                  * Make sure the old inode table is reserved in the
 998                  * block reservation bitmap.
 999                  */
1000                 for (blk = rfs->old_fs->group_desc[i].bg_inode_table, j=0;
1001                      j < fs->inode_blocks_per_group ; j++, blk++)
1002                         ext2fs_mark_block_bitmap(rfs->reserve_blocks, blk);
1003
1004         next_group:
1005                 group_blk += rfs->new_fs->super->s_blocks_per_group;
1006         }
1007         retval = 0;
1008
1009 errout:
1010         if (meta_bmap)
1011                 ext2fs_free_block_bitmap(meta_bmap);
1012
1013         return retval;
1014 }
1015
1016 /*
1017  * This helper function tries to allocate a new block.  We try to
1018  * avoid hitting the original group descriptor blocks at least at
1019  * first, since we want to make it possible to recover from a badly
1020  * aborted resize operation as much as possible.
1021  *
1022  * In the future, I may further modify this routine to balance out
1023  * where we get the new blocks across the various block groups.
1024  * Ideally we would allocate blocks that corresponded with the block
1025  * group of the containing inode, and keep contiguous blocks
1026  * together.  However, this very difficult to do efficiently, since we
1027  * don't have the necessary information up front.
1028  */
1029
1030 #define AVOID_OLD       1
1031 #define DESPERATION     2
1032
1033 static void init_block_alloc(ext2_resize_t rfs)
1034 {
1035         rfs->alloc_state = AVOID_OLD;
1036         rfs->new_blk = rfs->new_fs->super->s_first_data_block;
1037 #if 0
1038         /* HACK for testing */
1039         if (rfs->new_fs->super->s_blocks_count >
1040             rfs->old_fs->super->s_blocks_count)
1041                 rfs->new_blk = rfs->old_fs->super->s_blocks_count;
1042 #endif
1043 }
1044
1045 static blk_t get_new_block(ext2_resize_t rfs)
1046 {
1047         ext2_filsys     fs = rfs->new_fs;
1048
1049         while (1) {
1050                 if (rfs->new_blk >= fs->super->s_blocks_count) {
1051                         if (rfs->alloc_state == DESPERATION)
1052                                 return 0;
1053
1054 #ifdef RESIZE2FS_DEBUG
1055                         if (rfs->flags & RESIZE_DEBUG_BMOVE)
1056                                 printf("Going into desperation mode "
1057                                        "for block allocations\n");
1058 #endif
1059                         rfs->alloc_state = DESPERATION;
1060                         rfs->new_blk = fs->super->s_first_data_block;
1061                         continue;
1062                 }
1063                 if (ext2fs_test_block_bitmap(fs->block_map, rfs->new_blk) ||
1064                     ext2fs_test_block_bitmap(rfs->reserve_blocks,
1065                                              rfs->new_blk) ||
1066                     ((rfs->alloc_state == AVOID_OLD) &&
1067                      (rfs->new_blk < rfs->old_fs->super->s_blocks_count) &&
1068                      ext2fs_test_block_bitmap(rfs->old_fs->block_map,
1069                                               rfs->new_blk))) {
1070                         rfs->new_blk++;
1071                         continue;
1072                 }
1073                 return rfs->new_blk;
1074         }
1075 }
1076
1077 static errcode_t resize2fs_get_alloc_block(ext2_filsys fs, blk64_t goal,
1078                                            blk64_t *ret)
1079 {
1080         ext2_resize_t rfs = (ext2_resize_t) fs->priv_data;
1081         blk_t blk;
1082
1083         blk = get_new_block(rfs);
1084         if (!blk)
1085                 return ENOSPC;
1086
1087 #ifdef RESIZE2FS_DEBUG
1088         if (rfs->flags & 0xF)
1089                 printf("get_alloc_block allocating %u\n", blk);
1090 #endif
1091
1092         ext2fs_mark_block_bitmap(rfs->old_fs->block_map, blk);
1093         ext2fs_mark_block_bitmap(rfs->new_fs->block_map, blk);
1094         *ret = (blk64_t) blk;
1095         return 0;
1096 }
1097
1098 static errcode_t block_mover(ext2_resize_t rfs)
1099 {
1100         blk_t                   blk, old_blk, new_blk;
1101         ext2_filsys             fs = rfs->new_fs;
1102         ext2_filsys             old_fs = rfs->old_fs;
1103         errcode_t               retval;
1104         int                     size, c;
1105         int                     to_move, moved;
1106         ext2_badblocks_list     badblock_list = 0;
1107         int                     bb_modified = 0;
1108
1109         fs->get_alloc_block = resize2fs_get_alloc_block;
1110         old_fs->get_alloc_block = resize2fs_get_alloc_block;
1111
1112         retval = ext2fs_read_bb_inode(old_fs, &badblock_list);
1113         if (retval)
1114                 return retval;
1115
1116         new_blk = fs->super->s_first_data_block;
1117         if (!rfs->itable_buf) {
1118                 retval = ext2fs_get_array(fs->blocksize,
1119                                         fs->inode_blocks_per_group,
1120                                         &rfs->itable_buf);
1121                 if (retval)
1122                         return retval;
1123         }
1124         retval = ext2fs_create_extent_table(&rfs->bmap, 0);
1125         if (retval)
1126                 return retval;
1127
1128         /*
1129          * The first step is to figure out where all of the blocks
1130          * will go.
1131          */
1132         to_move = moved = 0;
1133         init_block_alloc(rfs);
1134         for (blk = old_fs->super->s_first_data_block;
1135              blk < old_fs->super->s_blocks_count; blk++) {
1136                 if (!ext2fs_test_block_bitmap(old_fs->block_map, blk))
1137                         continue;
1138                 if (!ext2fs_test_block_bitmap(rfs->move_blocks, blk))
1139                         continue;
1140                 if (ext2fs_badblocks_list_test(badblock_list, blk)) {
1141                         ext2fs_badblocks_list_del(badblock_list, blk);
1142                         bb_modified++;
1143                         continue;
1144                 }
1145
1146                 new_blk = get_new_block(rfs);
1147                 if (!new_blk) {
1148                         retval = ENOSPC;
1149                         goto errout;
1150                 }
1151                 ext2fs_block_alloc_stats(fs, new_blk, +1);
1152                 ext2fs_add_extent_entry(rfs->bmap, blk, new_blk);
1153                 to_move++;
1154         }
1155
1156         if (to_move == 0) {
1157                 if (rfs->bmap) {
1158                         ext2fs_free_extent_table(rfs->bmap);
1159                         rfs->bmap = 0;
1160                 }
1161                 retval = 0;
1162                 goto errout;
1163         }
1164
1165         /*
1166          * Step two is to actually move the blocks
1167          */
1168         retval =  ext2fs_iterate_extent(rfs->bmap, 0, 0, 0);
1169         if (retval) goto errout;
1170
1171         if (rfs->progress) {
1172                 retval = (rfs->progress)(rfs, E2_RSZ_BLOCK_RELOC_PASS,
1173                                          0, to_move);
1174                 if (retval)
1175                         goto errout;
1176         }
1177         while (1) {
1178                 retval = ext2fs_iterate_extent(rfs->bmap, &old_blk, &new_blk, &size);
1179                 if (retval) goto errout;
1180                 if (!size)
1181                         break;
1182 #ifdef RESIZE2FS_DEBUG
1183                 if (rfs->flags & RESIZE_DEBUG_BMOVE)
1184                         printf("Moving %d blocks %u->%u\n",
1185                                size, old_blk, new_blk);
1186 #endif
1187                 do {
1188                         c = size;
1189                         if (c > fs->inode_blocks_per_group)
1190                                 c = fs->inode_blocks_per_group;
1191                         retval = io_channel_read_blk(fs->io, old_blk, c,
1192                                                      rfs->itable_buf);
1193                         if (retval) goto errout;
1194                         retval = io_channel_write_blk(fs->io, new_blk, c,
1195                                                       rfs->itable_buf);
1196                         if (retval) goto errout;
1197                         size -= c;
1198                         new_blk += c;
1199                         old_blk += c;
1200                         moved += c;
1201                         if (rfs->progress) {
1202                                 io_channel_flush(fs->io);
1203                                 retval = (rfs->progress)(rfs,
1204                                                 E2_RSZ_BLOCK_RELOC_PASS,
1205                                                 moved, to_move);
1206                                 if (retval)
1207                                         goto errout;
1208                         }
1209                 } while (size > 0);
1210                 io_channel_flush(fs->io);
1211         }
1212
1213 errout:
1214         if (badblock_list) {
1215                 if (!retval && bb_modified)
1216                         retval = ext2fs_update_bb_inode(old_fs,
1217                                                         badblock_list);
1218                 ext2fs_badblocks_list_free(badblock_list);
1219         }
1220         return retval;
1221 }
1222
1223
1224 /* --------------------------------------------------------------------
1225  *
1226  * Resize processing, phase 3
1227  *
1228  * --------------------------------------------------------------------
1229  */
1230
1231
1232 struct process_block_struct {
1233         ext2_resize_t           rfs;
1234         ext2_ino_t              ino;
1235         struct ext2_inode *     inode;
1236         errcode_t               error;
1237         int                     is_dir;
1238         int                     changed;
1239 };
1240
1241 static int process_block(ext2_filsys fs, blk_t  *block_nr,
1242                          e2_blkcnt_t blockcnt,
1243                          blk_t ref_block EXT2FS_ATTR((unused)),
1244                          int ref_offset EXT2FS_ATTR((unused)), void *priv_data)
1245 {
1246         struct process_block_struct *pb;
1247         errcode_t       retval;
1248         blk_t           block, new_block;
1249         int             ret = 0;
1250
1251         pb = (struct process_block_struct *) priv_data;
1252         block = *block_nr;
1253         if (pb->rfs->bmap) {
1254                 new_block = ext2fs_extent_translate(pb->rfs->bmap, block);
1255                 if (new_block) {
1256                         *block_nr = new_block;
1257                         ret |= BLOCK_CHANGED;
1258                         pb->changed = 1;
1259 #ifdef RESIZE2FS_DEBUG
1260                         if (pb->rfs->flags & RESIZE_DEBUG_BMOVE)
1261                                 printf("ino=%u, blockcnt=%lld, %u->%u\n",
1262                                        pb->ino, blockcnt, block, new_block);
1263 #endif
1264                         block = new_block;
1265                 }
1266         }
1267         if (pb->is_dir) {
1268                 retval = ext2fs_add_dir_block(fs->dblist, pb->ino,
1269                                               block, (int) blockcnt);
1270                 if (retval) {
1271                         pb->error = retval;
1272                         ret |= BLOCK_ABORT;
1273                 }
1274         }
1275         return ret;
1276 }
1277
1278 /*
1279  * Progress callback
1280  */
1281 static errcode_t progress_callback(ext2_filsys fs,
1282                                    ext2_inode_scan scan EXT2FS_ATTR((unused)),
1283                                    dgrp_t group, void * priv_data)
1284 {
1285         ext2_resize_t rfs = (ext2_resize_t) priv_data;
1286         errcode_t               retval;
1287
1288         /*
1289          * This check is to protect against old ext2 libraries.  It
1290          * shouldn't be needed against new libraries.
1291          */
1292         if ((group+1) == 0)
1293                 return 0;
1294
1295         if (rfs->progress) {
1296                 io_channel_flush(fs->io);
1297                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
1298                                          group+1, fs->group_desc_count);
1299                 if (retval)
1300                         return retval;
1301         }
1302
1303         return 0;
1304 }
1305
1306 static errcode_t inode_scan_and_fix(ext2_resize_t rfs)
1307 {
1308         struct process_block_struct     pb;
1309         ext2_ino_t              ino, new_inode;
1310         struct ext2_inode       *inode = NULL;
1311         ext2_inode_scan         scan = NULL;
1312         errcode_t               retval;
1313         char                    *block_buf = 0;
1314         ext2_ino_t              start_to_move;
1315         blk_t                   orig_size, new_block;
1316         int                     inode_size;
1317
1318         if ((rfs->old_fs->group_desc_count <=
1319              rfs->new_fs->group_desc_count) &&
1320             !rfs->bmap)
1321                 return 0;
1322
1323         /*
1324          * Save the original size of the old filesystem, and
1325          * temporarily set the size to be the new size if the new size
1326          * is larger.  We need to do this to avoid catching an error
1327          * by the block iterator routines
1328          */
1329         orig_size = rfs->old_fs->super->s_blocks_count;
1330         if (orig_size < rfs->new_fs->super->s_blocks_count)
1331                 rfs->old_fs->super->s_blocks_count =
1332                         rfs->new_fs->super->s_blocks_count;
1333
1334         retval = ext2fs_open_inode_scan(rfs->old_fs, 0, &scan);
1335         if (retval) goto errout;
1336
1337         retval = ext2fs_init_dblist(rfs->old_fs, 0);
1338         if (retval) goto errout;
1339         retval = ext2fs_get_array(rfs->old_fs->blocksize, 3, &block_buf);
1340         if (retval) goto errout;
1341
1342         start_to_move = (rfs->new_fs->group_desc_count *
1343                          rfs->new_fs->super->s_inodes_per_group);
1344
1345         if (rfs->progress) {
1346                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
1347                                          0, rfs->old_fs->group_desc_count);
1348                 if (retval)
1349                         goto errout;
1350         }
1351         ext2fs_set_inode_callback(scan, progress_callback, (void *) rfs);
1352         pb.rfs = rfs;
1353         pb.inode = inode;
1354         pb.error = 0;
1355         new_inode = EXT2_FIRST_INODE(rfs->new_fs->super);
1356         inode_size = EXT2_INODE_SIZE(rfs->new_fs->super);
1357         inode = malloc(inode_size);
1358         if (!inode) {
1359                 retval = ENOMEM;
1360                 goto errout;
1361         }
1362         /*
1363          * First, copy all of the inodes that need to be moved
1364          * elsewhere in the inode table
1365          */
1366         while (1) {
1367                 retval = ext2fs_get_next_inode_full(scan, &ino, inode, inode_size);
1368                 if (retval) goto errout;
1369                 if (!ino)
1370                         break;
1371
1372                 if (inode->i_links_count == 0 && ino != EXT2_RESIZE_INO)
1373                         continue; /* inode not in use */
1374
1375                 pb.is_dir = LINUX_S_ISDIR(inode->i_mode);
1376                 pb.changed = 0;
1377
1378                 if (inode->i_file_acl && rfs->bmap) {
1379                         new_block = ext2fs_extent_translate(rfs->bmap,
1380                                                             inode->i_file_acl);
1381                         if (new_block) {
1382                                 inode->i_file_acl = new_block;
1383                                 retval = ext2fs_write_inode_full(rfs->old_fs,
1384                                                             ino, inode, inode_size);
1385                                 if (retval) goto errout;
1386                         }
1387                 }
1388
1389                 if (ext2fs_inode_has_valid_blocks(inode) &&
1390                     (rfs->bmap || pb.is_dir)) {
1391                         pb.ino = ino;
1392                         retval = ext2fs_block_iterate2(rfs->old_fs,
1393                                                        ino, 0, block_buf,
1394                                                        process_block, &pb);
1395                         if (retval)
1396                                 goto errout;
1397                         if (pb.error) {
1398                                 retval = pb.error;
1399                                 goto errout;
1400                         }
1401                 }
1402
1403                 if (ino <= start_to_move)
1404                         continue; /* Don't need to move it. */
1405
1406                 /*
1407                  * Find a new inode
1408                  */
1409                 retval = ext2fs_new_inode(rfs->new_fs, 0, 0, 0, &new_inode);
1410                 if (retval)
1411                         goto errout;
1412
1413                 ext2fs_inode_alloc_stats2(rfs->new_fs, new_inode, +1,
1414                                           pb.is_dir);
1415                 if (pb.changed) {
1416                         /* Get the new version of the inode */
1417                         retval = ext2fs_read_inode_full(rfs->old_fs, ino,
1418                                                 inode, inode_size);
1419                         if (retval) goto errout;
1420                 }
1421                 inode->i_ctime = time(0);
1422                 retval = ext2fs_write_inode_full(rfs->old_fs, new_inode,
1423                                                 inode, inode_size);
1424                 if (retval) goto errout;
1425
1426 #ifdef RESIZE2FS_DEBUG
1427                 if (rfs->flags & RESIZE_DEBUG_INODEMAP)
1428                         printf("Inode moved %u->%u\n", ino, new_inode);
1429 #endif
1430                 if (!rfs->imap) {
1431                         retval = ext2fs_create_extent_table(&rfs->imap, 0);
1432                         if (retval)
1433                                 goto errout;
1434                 }
1435                 ext2fs_add_extent_entry(rfs->imap, ino, new_inode);
1436         }
1437         io_channel_flush(rfs->old_fs->io);
1438
1439 errout:
1440         rfs->old_fs->super->s_blocks_count = orig_size;
1441         if (rfs->bmap) {
1442                 ext2fs_free_extent_table(rfs->bmap);
1443                 rfs->bmap = 0;
1444         }
1445         if (scan)
1446                 ext2fs_close_inode_scan(scan);
1447         if (block_buf)
1448                 ext2fs_free_mem(&block_buf);
1449         free(inode);
1450         return retval;
1451 }
1452
1453 /* --------------------------------------------------------------------
1454  *
1455  * Resize processing, phase 4.
1456  *
1457  * --------------------------------------------------------------------
1458  */
1459
1460 struct istruct {
1461         ext2_resize_t rfs;
1462         errcode_t       err;
1463         unsigned int    max_dirs;
1464         unsigned int    num;
1465 };
1466
1467 static int check_and_change_inodes(ext2_ino_t dir,
1468                                    int entry EXT2FS_ATTR((unused)),
1469                                    struct ext2_dir_entry *dirent, int offset,
1470                                    int  blocksize EXT2FS_ATTR((unused)),
1471                                    char *buf EXT2FS_ATTR((unused)),
1472                                    void *priv_data)
1473 {
1474         struct istruct *is = (struct istruct *) priv_data;
1475         struct ext2_inode       inode;
1476         ext2_ino_t              new_inode;
1477         errcode_t               retval;
1478
1479         if (is->rfs->progress && offset == 0) {
1480                 io_channel_flush(is->rfs->old_fs->io);
1481                 is->err = (is->rfs->progress)(is->rfs,
1482                                               E2_RSZ_INODE_REF_UPD_PASS,
1483                                               ++is->num, is->max_dirs);
1484                 if (is->err)
1485                         return DIRENT_ABORT;
1486         }
1487
1488         if (!dirent->inode)
1489                 return 0;
1490
1491         new_inode = ext2fs_extent_translate(is->rfs->imap, dirent->inode);
1492
1493         if (!new_inode)
1494                 return 0;
1495 #ifdef RESIZE2FS_DEBUG
1496         if (is->rfs->flags & RESIZE_DEBUG_INODEMAP)
1497                 printf("Inode translate (dir=%u, name=%.*s, %u->%u)\n",
1498                        dir, dirent->name_len&0xFF, dirent->name,
1499                        dirent->inode, new_inode);
1500 #endif
1501
1502         dirent->inode = new_inode;
1503
1504         /* Update the directory mtime and ctime */
1505         retval = ext2fs_read_inode(is->rfs->old_fs, dir, &inode);
1506         if (retval == 0) {
1507                 inode.i_mtime = inode.i_ctime = time(0);
1508                 is->err = ext2fs_write_inode(is->rfs->old_fs, dir, &inode);
1509                 if (is->err)
1510                         return DIRENT_ABORT;
1511         }
1512
1513         return DIRENT_CHANGED;
1514 }
1515
1516 static errcode_t inode_ref_fix(ext2_resize_t rfs)
1517 {
1518         errcode_t               retval;
1519         struct istruct          is;
1520
1521         if (!rfs->imap)
1522                 return 0;
1523
1524         /*
1525          * Now, we iterate over all of the directories to update the
1526          * inode references
1527          */
1528         is.num = 0;
1529         is.max_dirs = ext2fs_dblist_count(rfs->old_fs->dblist);
1530         is.rfs = rfs;
1531         is.err = 0;
1532
1533         if (rfs->progress) {
1534                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS,
1535                                          0, is.max_dirs);
1536                 if (retval)
1537                         goto errout;
1538         }
1539
1540         retval = ext2fs_dblist_dir_iterate(rfs->old_fs->dblist,
1541                                            DIRENT_FLAG_INCLUDE_EMPTY, 0,
1542                                            check_and_change_inodes, &is);
1543         if (retval)
1544                 goto errout;
1545         if (is.err) {
1546                 retval = is.err;
1547                 goto errout;
1548         }
1549
1550         if (rfs->progress && (is.num < is.max_dirs))
1551                 (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS,
1552                                 is.max_dirs, is.max_dirs);
1553
1554 errout:
1555         ext2fs_free_extent_table(rfs->imap);
1556         rfs->imap = 0;
1557         return retval;
1558 }
1559
1560
1561 /* --------------------------------------------------------------------
1562  *
1563  * Resize processing, phase 5.
1564  *
1565  * In this phase we actually move the inode table around, and then
1566  * update the summary statistics.  This is scary, since aborting here
1567  * will potentially scramble the filesystem.  (We are moving the
1568  * inode tables around in place, and so the potential for lost data,
1569  * or at the very least scrambling the mapping between filenames and
1570  * inode numbers is very high in case of a power failure here.)
1571  * --------------------------------------------------------------------
1572  */
1573
1574
1575 /*
1576  * A very scary routine --- this one moves the inode table around!!!
1577  *
1578  * After this you have to use the rfs->new_fs file handle to read and
1579  * write inodes.
1580  */
1581 static errcode_t move_itables(ext2_resize_t rfs)
1582 {
1583         int             n, num, size, diff;
1584         dgrp_t          i, max_groups;
1585         ext2_filsys     fs = rfs->new_fs;
1586         char            *cp;
1587         blk_t           old_blk, new_blk, blk;
1588         errcode_t       retval;
1589         int             j, to_move, moved;
1590
1591         max_groups = fs->group_desc_count;
1592         if (max_groups > rfs->old_fs->group_desc_count)
1593                 max_groups = rfs->old_fs->group_desc_count;
1594
1595         size = fs->blocksize * fs->inode_blocks_per_group;
1596         if (!rfs->itable_buf) {
1597                 retval = ext2fs_get_mem(size, &rfs->itable_buf);
1598                 if (retval)
1599                         return retval;
1600         }
1601
1602         /*
1603          * Figure out how many inode tables we need to move
1604          */
1605         to_move = moved = 0;
1606         for (i=0; i < max_groups; i++)
1607                 if (rfs->old_fs->group_desc[i].bg_inode_table !=
1608                     fs->group_desc[i].bg_inode_table)
1609                         to_move++;
1610
1611         if (to_move == 0)
1612                 return 0;
1613
1614         if (rfs->progress) {
1615                 retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
1616                                        0, to_move);
1617                 if (retval)
1618                         goto errout;
1619         }
1620
1621         rfs->old_fs->flags |= EXT2_FLAG_MASTER_SB_ONLY;
1622
1623         for (i=0; i < max_groups; i++) {
1624                 old_blk = rfs->old_fs->group_desc[i].bg_inode_table;
1625                 new_blk = fs->group_desc[i].bg_inode_table;
1626                 diff = new_blk - old_blk;
1627
1628 #ifdef RESIZE2FS_DEBUG
1629                 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1630                         printf("Itable move group %d block %u->%u (diff %d)\n",
1631                                i, old_blk, new_blk, diff);
1632 #endif
1633
1634                 if (!diff)
1635                         continue;
1636
1637                 retval = io_channel_read_blk(fs->io, old_blk,
1638                                              fs->inode_blocks_per_group,
1639                                              rfs->itable_buf);
1640                 if (retval)
1641                         goto errout;
1642                 /*
1643                  * The end of the inode table segment often contains
1644                  * all zeros, and we're often only moving the inode
1645                  * table down a block or two.  If so, we can optimize
1646                  * things by not rewriting blocks that we know to be zero
1647                  * already.
1648                  */
1649                 for (cp = rfs->itable_buf+size-1, n=0; n < size; n++, cp--)
1650                         if (*cp)
1651                                 break;
1652                 n = n >> EXT2_BLOCK_SIZE_BITS(fs->super);
1653 #ifdef RESIZE2FS_DEBUG
1654                 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1655                         printf("%d blocks of zeros...\n", n);
1656 #endif
1657                 num = fs->inode_blocks_per_group;
1658                 if (n > diff)
1659                         num -= n;
1660
1661                 retval = io_channel_write_blk(fs->io, new_blk,
1662                                               num, rfs->itable_buf);
1663                 if (retval) {
1664                         io_channel_write_blk(fs->io, old_blk,
1665                                              num, rfs->itable_buf);
1666                         goto errout;
1667                 }
1668                 if (n > diff) {
1669                         retval = io_channel_write_blk(fs->io,
1670                               old_blk + fs->inode_blocks_per_group,
1671                               diff, (rfs->itable_buf +
1672                                      (fs->inode_blocks_per_group - diff) *
1673                                      fs->blocksize));
1674                         if (retval)
1675                                 goto errout;
1676                 }
1677
1678                 for (blk = rfs->old_fs->group_desc[i].bg_inode_table, j=0;
1679                      j < fs->inode_blocks_per_group ; j++, blk++)
1680                         ext2fs_block_alloc_stats(fs, blk, -1);
1681
1682                 rfs->old_fs->group_desc[i].bg_inode_table = new_blk;
1683                 ext2fs_group_desc_csum_set(rfs->old_fs, i);
1684                 ext2fs_mark_super_dirty(rfs->old_fs);
1685                 ext2fs_flush(rfs->old_fs);
1686
1687                 if (rfs->progress) {
1688                         retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
1689                                                ++moved, to_move);
1690                         if (retval)
1691                                 goto errout;
1692                 }
1693         }
1694         mark_table_blocks(fs, fs->block_map);
1695         ext2fs_flush(fs);
1696 #ifdef RESIZE2FS_DEBUG
1697         if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1698                 printf("Inode table move finished.\n");
1699 #endif
1700         return 0;
1701
1702 errout:
1703         return retval;
1704 }
1705
1706 /*
1707  * Fix the resize inode
1708  */
1709 static errcode_t fix_resize_inode(ext2_filsys fs)
1710 {
1711         struct ext2_inode       inode;
1712         errcode_t               retval;
1713         char *                  block_buf;
1714         blk_t                   blk;
1715
1716         if (!(fs->super->s_feature_compat &
1717               EXT2_FEATURE_COMPAT_RESIZE_INODE))
1718                 return 0;
1719
1720         retval = ext2fs_get_mem(fs->blocksize, &block_buf);
1721         if (retval) goto errout;
1722
1723         retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode);
1724         if (retval) goto errout;
1725
1726         if (fs->super->s_reserved_gdt_blocks == 0) {
1727                 fs->super->s_feature_compat &=
1728                         ~EXT2_FEATURE_COMPAT_RESIZE_INODE;
1729                 ext2fs_mark_super_dirty(fs);
1730
1731                 if ((blk = inode.i_block[EXT2_DIND_BLOCK]) != 0)
1732                         ext2fs_block_alloc_stats(fs, blk, -1);
1733
1734                 memset(&inode, 0, sizeof(inode));
1735
1736                 retval = ext2fs_write_inode(fs, EXT2_RESIZE_INO, &inode);
1737                 goto errout;
1738         }
1739
1740         ext2fs_iblk_set(fs, &inode, 1);
1741
1742         retval = ext2fs_write_inode(fs, EXT2_RESIZE_INO, &inode);
1743         if (retval) goto errout;
1744
1745         if (!inode.i_block[EXT2_DIND_BLOCK]) {
1746                 /*
1747                  * Avoid zeroing out block #0; that's rude.  This
1748                  * should never happen anyway since the filesystem
1749                  * should be fsck'ed and we assume it is consistent.
1750                  */
1751                 fprintf(stderr,
1752                         _("Should never happen: resize inode corrupt!\n"));
1753                 exit(1);
1754         }
1755
1756         memset(block_buf, 0, fs->blocksize);
1757
1758         retval = io_channel_write_blk(fs->io, inode.i_block[EXT2_DIND_BLOCK],
1759                                       1, block_buf);
1760         if (retval) goto errout;
1761
1762         retval = ext2fs_create_resize_inode(fs);
1763         if (retval)
1764                 goto errout;
1765
1766 errout:
1767         if (block_buf)
1768                 ext2fs_free_mem(&block_buf);
1769         return retval;
1770 }
1771
1772 /*
1773  * Finally, recalculate the summary information
1774  */
1775 static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs)
1776 {
1777         blk_t           blk;
1778         ext2_ino_t      ino;
1779         unsigned int    group = 0;
1780         unsigned int    count = 0;
1781         int             total_free = 0;
1782         int             group_free = 0;
1783         int             uninit = 0;
1784         blk_t           super_blk, old_desc_blk, new_desc_blk;
1785         int             old_desc_blocks;
1786
1787         /*
1788          * First calculate the block statistics
1789          */
1790         uninit = fs->group_desc[group].bg_flags & EXT2_BG_BLOCK_UNINIT;
1791         ext2fs_super_and_bgd_loc(fs, group, &super_blk, &old_desc_blk,
1792                                  &new_desc_blk, 0);
1793         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
1794                 old_desc_blocks = fs->super->s_first_meta_bg;
1795         else
1796                 old_desc_blocks = fs->desc_blocks +
1797                         fs->super->s_reserved_gdt_blocks;
1798         for (blk = fs->super->s_first_data_block;
1799              blk < fs->super->s_blocks_count; blk++) {
1800                 if ((uninit &&
1801                      !((blk == super_blk) ||
1802                        ((old_desc_blk && old_desc_blocks &&
1803                          (blk >= old_desc_blk) &&
1804                          (blk < old_desc_blk + old_desc_blocks))) ||
1805                        ((new_desc_blk && (blk == new_desc_blk))) ||
1806                        (blk == fs->group_desc[group].bg_block_bitmap) ||
1807                        (blk == fs->group_desc[group].bg_inode_bitmap) ||
1808                        ((blk >= fs->group_desc[group].bg_inode_table &&
1809                          (blk < fs->group_desc[group].bg_inode_table
1810                           + fs->inode_blocks_per_group))))) ||
1811                     (!ext2fs_fast_test_block_bitmap(fs->block_map, blk))) {
1812                         group_free++;
1813                         total_free++;
1814                 }
1815                 count++;
1816                 if ((count == fs->super->s_blocks_per_group) ||
1817                     (blk == fs->super->s_blocks_count-1)) {
1818                         fs->group_desc[group].bg_free_blocks_count =
1819                                 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 = (fs->group_desc[group].bg_flags &
1827                                   EXT2_BG_BLOCK_UNINIT);
1828                         ext2fs_super_and_bgd_loc(fs, group, &super_blk,
1829                                                  &old_desc_blk,
1830                                                  &new_desc_blk, 0);
1831                         if (fs->super->s_feature_incompat &
1832                             EXT2_FEATURE_INCOMPAT_META_BG)
1833                                 old_desc_blocks = fs->super->s_first_meta_bg;
1834                         else
1835                                 old_desc_blocks = fs->desc_blocks +
1836                                         fs->super->s_reserved_gdt_blocks;
1837                 }
1838         }
1839         fs->super->s_free_blocks_count = total_free;
1840
1841         /*
1842          * Next, calculate the inode statistics
1843          */
1844         group_free = 0;
1845         total_free = 0;
1846         count = 0;
1847         group = 0;
1848
1849         /* Protect loop from wrap-around if s_inodes_count maxed */
1850         uninit = fs->group_desc[group].bg_flags & EXT2_BG_INODE_UNINIT;
1851         for (ino = 1; ino <= fs->super->s_inodes_count && ino > 0; ino++) {
1852                 if (uninit ||
1853                     !ext2fs_fast_test_inode_bitmap(fs->inode_map, ino)) {
1854                         group_free++;
1855                         total_free++;
1856                 }
1857                 count++;
1858                 if ((count == fs->super->s_inodes_per_group) ||
1859                     (ino == fs->super->s_inodes_count)) {
1860                         fs->group_desc[group].bg_free_inodes_count =
1861                                 group_free;
1862                         ext2fs_group_desc_csum_set(fs, group);
1863                         group++;
1864                         if (group >= fs->group_desc_count)
1865                                 break;
1866                         count = 0;
1867                         group_free = 0;
1868                         uninit = (fs->group_desc[group].bg_flags &
1869                                   EXT2_BG_INODE_UNINIT);
1870                 }
1871         }
1872         fs->super->s_free_inodes_count = total_free;
1873         ext2fs_mark_super_dirty(fs);
1874         return 0;
1875 }
1876
1877 /*
1878  *  Journal may have been relocated; update the backup journal blocks
1879  *  in the superblock.
1880  */
1881 static errcode_t fix_sb_journal_backup(ext2_filsys fs)
1882 {
1883         errcode_t         retval;
1884         struct ext2_inode inode;
1885
1886         if (!(fs->super->s_feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1887                 return 0;
1888
1889         /* External journal? Nothing to do. */
1890         if (fs->super->s_journal_dev && !fs->super->s_journal_inum)
1891                 return 0;
1892
1893         retval = ext2fs_read_inode(fs, fs->super->s_journal_inum, &inode);
1894         if (retval)
1895                 return retval;
1896         memcpy(fs->super->s_jnl_blocks, inode.i_block, EXT2_N_BLOCKS*4);
1897         fs->super->s_jnl_blocks[16] = inode.i_size;
1898         fs->super->s_jnl_backup_type = EXT3_JNL_BACKUP_BLOCKS;
1899         ext2fs_mark_super_dirty(fs);
1900         return 0;
1901 }
1902
1903 /*
1904  * calcluate the minimum number of blocks the given fs can be resized to
1905  */
1906 blk_t calculate_minimum_resize_size(ext2_filsys fs)
1907 {
1908         blk_t inode_count, blks_needed, groups, data_blocks;
1909         blk_t grp, data_needed, last_start;
1910         int overhead = 0, num_of_superblocks = 0;
1911         int extra_groups = 0;
1912         int flexbg_size = 1 << fs->super->s_log_groups_per_flex;
1913
1914         /*
1915          * first figure out how many group descriptors we need to
1916          * handle the number of inodes we have
1917          */
1918         inode_count = fs->super->s_inodes_count -
1919                 fs->super->s_free_inodes_count;
1920         blks_needed = ext2fs_div_ceil(inode_count,
1921                                       fs->super->s_inodes_per_group) *
1922                 EXT2_BLOCKS_PER_GROUP(fs->super);
1923         groups = ext2fs_div_ceil(blks_needed,
1924                                  EXT2_BLOCKS_PER_GROUP(fs->super));
1925
1926         /*
1927          * we need to figure out how many backup superblocks we have so we can
1928          * account for that in the metadata
1929          */
1930         for (grp = 0; grp < fs->group_desc_count; grp++) {
1931                 if (ext2fs_bg_has_super(fs, grp))
1932                         num_of_superblocks++;
1933         }
1934
1935         /* calculate how many blocks are needed for data */
1936         data_needed = fs->super->s_blocks_count -
1937                 fs->super->s_free_blocks_count;
1938         data_needed -= SUPER_OVERHEAD(fs) * num_of_superblocks;
1939         data_needed -= META_OVERHEAD(fs) * fs->group_desc_count;
1940
1941         if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_FLEX_BG) {
1942                 /*
1943                  * For ext4 we need to allow for up to a flex_bg worth
1944                  * of inode tables of slack space so the resize
1945                  * operation can be guaranteed to finish.
1946                  */
1947                 extra_groups = flexbg_size - (groups & (flexbg_size - 1));
1948                 data_needed += META_OVERHEAD(fs) * extra_groups;
1949                 extra_groups = groups % flexbg_size;
1950         }
1951
1952         /*
1953          * figure out how many data blocks we have given the number of groups
1954          * we need for our inodes
1955          */
1956         data_blocks = groups * EXT2_BLOCKS_PER_GROUP(fs->super);
1957         last_start = 0;
1958         for (grp = 0; grp < groups; grp++) {
1959                 overhead = META_OVERHEAD(fs);
1960
1961                 if (ext2fs_bg_has_super(fs, grp))
1962                         overhead += SUPER_OVERHEAD(fs);
1963
1964                 /*
1965                  * we want to keep track of how much data we can store in
1966                  * the groups leading up to the last group so we can determine
1967                  * how big the last group needs to be
1968                  */
1969                 if (grp != (groups - 1))
1970                         last_start += EXT2_BLOCKS_PER_GROUP(fs->super) -
1971                                 overhead;
1972
1973                 data_blocks -= overhead;
1974         }
1975
1976         /*
1977          * if we need more group descriptors in order to accomodate our data
1978          * then we need to add them here
1979          */
1980         while (data_needed > data_blocks) {
1981                 blk_t remainder = data_needed - data_blocks;
1982                 blk_t extra_grps;
1983
1984                 /* figure out how many more groups we need for the data */
1985                 extra_grps = ext2fs_div_ceil(remainder,
1986                                              EXT2_BLOCKS_PER_GROUP(fs->super));
1987
1988                 data_blocks += extra_grps * EXT2_BLOCKS_PER_GROUP(fs->super);
1989
1990                 /* ok we have to account for the last group */
1991                 overhead = META_OVERHEAD(fs);
1992                 if (ext2fs_bg_has_super(fs, groups-1))
1993                         overhead += SUPER_OVERHEAD(fs);
1994                 last_start += EXT2_BLOCKS_PER_GROUP(fs->super) - overhead;
1995
1996                 for (grp = groups; grp < groups+extra_grps; grp++) {
1997                         overhead = META_OVERHEAD(fs);
1998                         if (ext2fs_bg_has_super(fs, grp))
1999                                 overhead += SUPER_OVERHEAD(fs);
2000
2001                         /*
2002                          * again, we need to see how much data we cram into
2003                          * all of the groups leading up to the last group
2004                          */
2005                         if (grp != (groups + extra_grps - 1))
2006                                 last_start += EXT2_BLOCKS_PER_GROUP(fs->super)
2007                                         - overhead;
2008
2009                         data_blocks -= overhead;
2010                 }
2011
2012                 groups += extra_grps;
2013                 extra_groups += extra_grps;
2014                 if (fs->super->s_feature_incompat
2015                         & EXT4_FEATURE_INCOMPAT_FLEX_BG
2016                     && extra_groups > flexbg_size) {
2017                         /*
2018                          * For ext4 we need to allow for up to a flex_bg worth
2019                          * of inode tables of slack space so the resize
2020                          * operation can be guaranteed to finish.
2021                          */
2022                         extra_groups = flexbg_size -
2023                                                 (groups & (flexbg_size - 1));
2024                         data_needed += META_OVERHEAD(fs) * extra_groups;
2025                         extra_groups = groups % flexbg_size;
2026                 }
2027         }
2028
2029         /* now for the fun voodoo */
2030         overhead = META_OVERHEAD(fs);
2031
2032         /*
2033          * if this is the case then the last group is going to have data in it
2034          * so we need to adjust the size of the last group accordingly
2035          */
2036         if (last_start < data_needed) {
2037                 blk_t remainder = data_needed - last_start;
2038
2039                 /*
2040                  * 50 is a magic number that mkfs/resize uses to see if its
2041                  * even worth making/resizing the fs.  basically you need to
2042                  * have at least 50 blocks in addition to the blocks needed
2043                  * for the metadata in the last group
2044                  */
2045                 if (remainder > 50)
2046                         overhead += remainder;
2047                 else
2048                         overhead += 50;
2049         } else
2050                 overhead += 50;
2051
2052         if (ext2fs_bg_has_super(fs, groups-1))
2053                 overhead += SUPER_OVERHEAD(fs);
2054
2055         /*
2056          * since our last group doesn't have to be BLOCKS_PER_GROUP large, we
2057          * only do groups-1, and then add the number of blocks needed to
2058          * handle the group descriptor metadata+data that we need
2059          */
2060         blks_needed = (groups-1) * EXT2_BLOCKS_PER_GROUP(fs->super);
2061         blks_needed += overhead;
2062
2063         /*
2064          * If at this point we've already added up more "needed" than
2065          * the current size, just return current size as minimum.
2066          */
2067         if (blks_needed >= fs->super->s_blocks_count)
2068                 return fs->super->s_blocks_count;
2069         /*
2070          * We need to reserve a few extra blocks if extents are
2071          * enabled, in case we need to grow the extent tree.  The more
2072          * we shrink the file system, the more space we need.
2073          */
2074         if (fs->super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_EXTENTS)
2075                 blks_needed += (fs->super->s_blocks_count - blks_needed)/500;
2076
2077         return blks_needed;
2078 }