resize/resize2fs.c

   1 /*
   2  * resize2fs.c --- ext2 main routine
   3  *
   4  * Copyright (C) 1997, 1998 by Theodore Ts'o and
   5  *      PowerQuest, Inc.
   6  *
   7  * Copyright (C) 1999, 2000 by Theosore Ts'o
   8  *
   9  * %Begin-Header%
  10  * This file may be redistributed under the terms of the GNU Public
  11  * License.
  12  * %End-Header%
  13  */
  14
  15 /*
  16  * Resizing a filesystem consists of the following phases:
  17  *
  18  *      1.  Adjust superblock and write out new parts of the inode
  19  *              table
  20  *      2.  Determine blocks which need to be relocated, and copy the
  21  *              contents of blocks from their old locations to the new ones.
  22  *      3.  Scan the inode table, doing the following:
  23  *              a.  If blocks have been moved, update the block
  24  *                      pointers in the inodes and indirect blocks to
  25  *                      point at the new block locations.
  26  *              b.  If parts of the inode table need to be evacuated,
  27  *                      copy inodes from their old locations to their
  28  *                      new ones.
  29  *              c.  If (b) needs to be done, note which blocks contain
  30  *                      directory information, since we will need to
  31  *                      update the directory information.
  32  *      4.  Update the directory blocks with the new inode locations.
  33  *      5.  Move the inode tables, if necessary.
  34  */
  35
  36 #include "config.h"
  37 #include "resize2fs.h"
  38 #include <time.h>
  39
  40 #ifdef __linux__                        /* Kludge for debugging */
  41 #define RESIZE2FS_DEBUG
  42 #endif
  43
  44 static void fix_uninit_block_bitmaps(ext2_filsys fs);
  45 static errcode_t adjust_superblock(ext2_resize_t rfs, blk64_t new_size);
  46 static errcode_t blocks_to_move(ext2_resize_t rfs);
  47 static errcode_t block_mover(ext2_resize_t rfs);
  48 static errcode_t inode_scan_and_fix(ext2_resize_t rfs);
  49 static errcode_t inode_ref_fix(ext2_resize_t rfs);
  50 static errcode_t move_itables(ext2_resize_t rfs);
  51 static errcode_t fix_resize_inode(ext2_filsys fs);
  52 static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs);
  53 static errcode_t fix_sb_journal_backup(ext2_filsys fs);
  54
  55 /*
  56  * Some helper CPP macros
  57  */
  58 #define IS_BLOCK_BM(fs, i, blk) ((blk) == ext2fs_block_bitmap_loc((fs),(i)))
  59 #define IS_INODE_BM(fs, i, blk) ((blk) == ext2fs_inode_bitmap_loc((fs),(i)))
  60
  61 #define IS_INODE_TB(fs, i, blk) (((blk) >= ext2fs_inode_table_loc((fs), (i))) && \
  62                                  ((blk) < (ext2fs_inode_table_loc((fs), (i)) + \
  63                                            (fs)->inode_blocks_per_group)))
  64
  65 int lazy_itable_init;
  66
  67 /*
  68  * This is the top-level routine which does the dirty deed....
  69  */
  70 errcode_t resize_fs(ext2_filsys fs, blk64_t *new_size, int flags,
  71             errcode_t (*progress)(ext2_resize_t rfs, int pass,
  72                                           unsigned long cur,
  73                                           unsigned long max_val))
  74 {
  75         ext2_resize_t   rfs;
  76         errcode_t       retval;
  77         struct resource_track   rtrack, overall_track;
  78
  79         /*
  80          * Create the data structure
  81          */
  82         retval = ext2fs_get_mem(sizeof(struct ext2_resize_struct), &rfs);
  83         if (retval)
  84                 return retval;
  85
  86         memset(rfs, 0, sizeof(struct ext2_resize_struct));
  87         fs->priv_data = rfs;
  88         rfs->old_fs = fs;
  89         rfs->flags = flags;
  90         rfs->itable_buf  = 0;
  91         rfs->progress = progress;
  92
  93         init_resource_track(&overall_track, "overall resize2fs", fs->io);
  94         init_resource_track(&rtrack, "read_bitmaps", fs->io);
  95         retval = ext2fs_read_bitmaps(fs);
  96         if (retval)
  97                 goto errout;
  98         print_resource_track(rfs, &rtrack, fs->io);
  99
 100         fs->super->s_state |= EXT2_ERROR_FS;
 101         ext2fs_mark_super_dirty(fs);
 102         ext2fs_flush(fs);
 103
 104         init_resource_track(&rtrack, "fix_uninit_block_bitmaps 1", fs->io);
 105         fix_uninit_block_bitmaps(fs);
 106         print_resource_track(rfs, &rtrack, fs->io);
 107         retval = ext2fs_dup_handle(fs, &rfs->new_fs);
 108         if (retval)
 109                 goto errout;
 110
 111         init_resource_track(&rtrack, "adjust_superblock", fs->io);
 112         retval = adjust_superblock(rfs, *new_size);
 113         if (retval)
 114                 goto errout;
 115         print_resource_track(rfs, &rtrack, fs->io);
 116
 117
 118         init_resource_track(&rtrack, "fix_uninit_block_bitmaps 2", fs->io);
 119         fix_uninit_block_bitmaps(rfs->new_fs);
 120         print_resource_track(rfs, &rtrack, fs->io);
 121         /* Clear the block bitmap uninit flag for the last block group */
 122         ext2fs_bg_flags_clear(rfs->new_fs, rfs->new_fs->group_desc_count - 1,
 123                              EXT2_BG_BLOCK_UNINIT);
 124
 125         *new_size = ext2fs_blocks_count(rfs->new_fs->super);
 126
 127         init_resource_track(&rtrack, "blocks_to_move", fs->io);
 128         retval = blocks_to_move(rfs);
 129         if (retval)
 130                 goto errout;
 131         print_resource_track(rfs, &rtrack, fs->io);
 132
 133 #ifdef RESIZE2FS_DEBUG
 134         if (rfs->flags & RESIZE_DEBUG_BMOVE)
 135                 printf("Number of free blocks: %llu/%llu, Needed: %llu\n",
 136                        ext2fs_free_blocks_count(rfs->old_fs->super),
 137                        ext2fs_free_blocks_count(rfs->new_fs->super),
 138                        rfs->needed_blocks);
 139 #endif
 140
 141         init_resource_track(&rtrack, "block_mover", fs->io);
 142         retval = block_mover(rfs);
 143         if (retval)
 144                 goto errout;
 145         print_resource_track(rfs, &rtrack, fs->io);
 146
 147         init_resource_track(&rtrack, "inode_scan_and_fix", fs->io);
 148         retval = inode_scan_and_fix(rfs);
 149         if (retval)
 150                 goto errout;
 151         print_resource_track(rfs, &rtrack, fs->io);
 152
 153         init_resource_track(&rtrack, "inode_ref_fix", fs->io);
 154         retval = inode_ref_fix(rfs);
 155         if (retval)
 156                 goto errout;
 157         print_resource_track(rfs, &rtrack, fs->io);
 158
 159         init_resource_track(&rtrack, "move_itables", fs->io);
 160         retval = move_itables(rfs);
 161         if (retval)
 162                 goto errout;
 163         print_resource_track(rfs, &rtrack, fs->io);
 164
 165         init_resource_track(&rtrack, "calculate_summary_stats", fs->io);
 166         retval = ext2fs_calculate_summary_stats(rfs->new_fs);
 167         if (retval)
 168                 goto errout;
 169         print_resource_track(rfs, &rtrack, fs->io);
 170
 171         init_resource_track(&rtrack, "fix_resize_inode", fs->io);
 172         retval = fix_resize_inode(rfs->new_fs);
 173         if (retval)
 174                 goto errout;
 175         print_resource_track(rfs, &rtrack, fs->io);
 176
 177         init_resource_track(&rtrack, "fix_sb_journal_backup", fs->io);
 178         retval = fix_sb_journal_backup(rfs->new_fs);
 179         if (retval)
 180                 goto errout;
 181         print_resource_track(rfs, &rtrack, fs->io);
 182
 183         rfs->new_fs->super->s_state &= ~EXT2_ERROR_FS;
 184         rfs->new_fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
 185
 186         print_resource_track(rfs, &overall_track, fs->io);
 187         retval = ext2fs_close(rfs->new_fs);
 188         if (retval)
 189                 goto errout;
 190
 191         rfs->flags = flags;
 192
 193         ext2fs_free(rfs->old_fs);
 194         if (rfs->itable_buf)
 195                 ext2fs_free_mem(&rfs->itable_buf);
 196         if (rfs->reserve_blocks)
 197                 ext2fs_free_block_bitmap(rfs->reserve_blocks);
 198         if (rfs->move_blocks)
 199                 ext2fs_free_block_bitmap(rfs->move_blocks);
 200         ext2fs_free_mem(&rfs);
 201
 202         return 0;
 203
 204 errout:
 205         if (rfs->new_fs)
 206                 ext2fs_free(rfs->new_fs);
 207         if (rfs->itable_buf)
 208                 ext2fs_free_mem(&rfs->itable_buf);
 209         ext2fs_free_mem(&rfs);
 210         return retval;
 211 }
 212
 213 /*
 214  * Clean up the bitmaps for unitialized bitmaps
 215  */
 216 static void fix_uninit_block_bitmaps(ext2_filsys fs)
 217 {
 218         blk64_t         blk, lblk;
 219         dgrp_t          g;
 220         int             i;
 221
 222         if (!(EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 223                                          EXT4_FEATURE_RO_COMPAT_GDT_CSUM)))
 224                 return;
 225
 226         for (g=0; g < fs->group_desc_count; g++) {
 227                 if (!(ext2fs_bg_flags_test(fs, g, EXT2_BG_BLOCK_UNINIT)))
 228                         continue;
 229
 230                 blk = ext2fs_group_first_block2(fs, g);
 231                 lblk = ext2fs_group_last_block2(fs, g);
 232                 ext2fs_unmark_block_bitmap_range2(fs->block_map, blk,
 233                                                   lblk - blk + 1);
 234
 235                 ext2fs_reserve_super_and_bgd(fs, g, fs->block_map);
 236                 ext2fs_mark_block_bitmap2(fs->block_map,
 237                                           ext2fs_block_bitmap_loc(fs, g));
 238                 ext2fs_mark_block_bitmap2(fs->block_map,
 239                                           ext2fs_inode_bitmap_loc(fs, g));
 240                 for (i = 0, blk = ext2fs_inode_table_loc(fs, g);
 241                      i < (unsigned int) fs->inode_blocks_per_group;
 242                      i++, blk++)
 243                         ext2fs_mark_block_bitmap2(fs->block_map, blk);
 244         }
 245 }
 246
 247 /* --------------------------------------------------------------------
 248  *
 249  * Resize processing, phase 1.
 250  *
 251  * In this phase we adjust the in-memory superblock information, and
 252  * initialize any new parts of the inode table.  The new parts of the
 253  * inode table are created in virgin disk space, so we can abort here
 254  * without any side effects.
 255  * --------------------------------------------------------------------
 256  */
 257
 258 /*
 259  * If the group descriptor's bitmap and inode table blocks are valid,
 260  * release them in the new filesystem data structure, and mark them as
 261  * reserved so the old inode table blocks don't get overwritten.
 262  */
 263 static void free_gdp_blocks(ext2_filsys fs,
 264                             ext2fs_block_bitmap reserve_blocks,
 265                             struct ext2_group_desc *gdp)
 266 {
 267         blk_t   blk;
 268         int     j;
 269
 270         if (gdp->bg_block_bitmap &&
 271             (gdp->bg_block_bitmap < ext2fs_blocks_count(fs->super))) {
 272                 ext2fs_block_alloc_stats(fs, gdp->bg_block_bitmap, -1);
 273                 ext2fs_mark_block_bitmap2(reserve_blocks,
 274                                          gdp->bg_block_bitmap);
 275         }
 276
 277         if (gdp->bg_inode_bitmap &&
 278             (gdp->bg_inode_bitmap < ext2fs_blocks_count(fs->super))) {
 279                 ext2fs_block_alloc_stats(fs, gdp->bg_inode_bitmap, -1);
 280                 ext2fs_mark_block_bitmap2(reserve_blocks,
 281                                          gdp->bg_inode_bitmap);
 282         }
 283
 284         if (gdp->bg_inode_table == 0 ||
 285             (gdp->bg_inode_table >= ext2fs_blocks_count(fs->super)))
 286                 return;
 287
 288         for (blk = gdp->bg_inode_table, j = 0;
 289              j < fs->inode_blocks_per_group; j++, blk++) {
 290                 if (blk >= ext2fs_blocks_count(fs->super))
 291                         break;
 292                 ext2fs_block_alloc_stats(fs, blk, -1);
 293                 ext2fs_mark_block_bitmap2(reserve_blocks, blk);
 294         }
 295 }
 296
 297 /*
 298  * This routine is shared by the online and offline resize routines.
 299  * All of the information which is adjusted in memory is done here.
 300  *
 301  * The reserve_blocks parameter is only needed when shrinking the
 302  * filesystem.
 303  */
 304 errcode_t adjust_fs_info(ext2_filsys fs, ext2_filsys old_fs,
 305                          ext2fs_block_bitmap reserve_blocks, blk64_t new_size)
 306 {
 307         errcode_t       retval;
 308         blk64_t         overhead = 0;
 309         blk64_t         rem;
 310         blk64_t         blk, group_block;
 311         blk64_t         real_end;
 312         blk64_t         old_numblocks, numblocks, adjblocks;
 313         unsigned long   i, j, old_desc_blocks;
 314         unsigned int    meta_bg, meta_bg_size;
 315         int             has_super, csum_flag;
 316         unsigned long long new_inodes;  /* u64 to check for overflow */
 317         double          percent;
 318
 319         ext2fs_blocks_count_set(fs->super, new_size);
 320
 321 retry:
 322         fs->group_desc_count = ext2fs_div64_ceil(ext2fs_blocks_count(fs->super) -
 323                                        fs->super->s_first_data_block,
 324                                        EXT2_BLOCKS_PER_GROUP(fs->super));
 325         if (fs->group_desc_count == 0)
 326                 return EXT2_ET_TOOSMALL;
 327         fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count,
 328                                           EXT2_DESC_PER_BLOCK(fs->super));
 329
 330         /*
 331          * Overhead is the number of bookkeeping blocks per group.  It
 332          * includes the superblock backup, the group descriptor
 333          * backups, the inode bitmap, the block bitmap, and the inode
 334          * table.
 335          */
 336         overhead = (int) (2 + fs->inode_blocks_per_group);
 337
 338         if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1))
 339                 overhead += 1 + fs->desc_blocks +
 340                         fs->super->s_reserved_gdt_blocks;
 341
 342         /*
 343          * See if the last group is big enough to support the
 344          * necessary data structures.  If not, we need to get rid of
 345          * it.
 346          */
 347         rem = (ext2fs_blocks_count(fs->super) - fs->super->s_first_data_block) %
 348                 fs->super->s_blocks_per_group;
 349         if ((fs->group_desc_count == 1) && rem && (rem < overhead))
 350                 return EXT2_ET_TOOSMALL;
 351         if ((fs->group_desc_count > 1) && rem && (rem < overhead+50)) {
 352                 ext2fs_blocks_count_set(fs->super,
 353                                         ext2fs_blocks_count(fs->super) - rem);
 354                 goto retry;
 355         }
 356         /*
 357          * Adjust the number of inodes
 358          */
 359         new_inodes =(unsigned long long) fs->super->s_inodes_per_group * fs->group_desc_count;
 360         if (new_inodes > ~0U) {
 361                 fprintf(stderr, _("inodes (%llu) must be less than %u"),
 362                                    new_inodes, ~0U);
 363                 return EXT2_ET_TOO_MANY_INODES;
 364         }
 365         fs->super->s_inodes_count = fs->super->s_inodes_per_group *
 366                 fs->group_desc_count;
 367
 368         /*
 369          * Adjust the number of free blocks
 370          */
 371         blk = ext2fs_blocks_count(old_fs->super);
 372         if (blk > ext2fs_blocks_count(fs->super))
 373                 ext2fs_free_blocks_count_set(fs->super,
 374                         ext2fs_free_blocks_count(fs->super) -
 375                         (blk - ext2fs_blocks_count(fs->super)));
 376         else
 377                 ext2fs_free_blocks_count_set(fs->super,
 378                         ext2fs_free_blocks_count(fs->super) +
 379                         (ext2fs_blocks_count(fs->super) - blk));
 380
 381         /*
 382          * Adjust the number of reserved blocks
 383          */
 384         percent = (ext2fs_r_blocks_count(old_fs->super) * 100.0) /
 385                 ext2fs_blocks_count(old_fs->super);
 386         ext2fs_r_blocks_count_set(fs->super,
 387                                   (percent * ext2fs_blocks_count(fs->super) /
 388                                    100.0));
 389
 390         /*
 391          * Adjust the bitmaps for size
 392          */
 393         retval = ext2fs_resize_inode_bitmap2(fs->super->s_inodes_count,
 394                                             fs->super->s_inodes_count,
 395                                             fs->inode_map);
 396         if (retval) goto errout;
 397
 398         real_end = (((blk64_t) EXT2_BLOCKS_PER_GROUP(fs->super) *
 399                      fs->group_desc_count)) - 1 +
 400                 fs->super->s_first_data_block;
 401         retval = ext2fs_resize_block_bitmap2(ext2fs_blocks_count(fs->super)-1,
 402                                             real_end, fs->block_map);
 403
 404         if (retval) goto errout;
 405
 406         /*
 407          * Reallocate the group descriptors as necessary.
 408          */
 409         if (old_fs->desc_blocks != fs->desc_blocks) {
 410                 retval = ext2fs_resize_mem(old_fs->desc_blocks *
 411                                            fs->blocksize,
 412                                            fs->desc_blocks * fs->blocksize,
 413                                            &fs->group_desc);
 414                 if (retval)
 415                         goto errout;
 416                 if (fs->desc_blocks > old_fs->desc_blocks)
 417                         memset((char *) fs->group_desc +
 418                                (old_fs->desc_blocks * fs->blocksize), 0,
 419                                (fs->desc_blocks - old_fs->desc_blocks) *
 420                                fs->blocksize);
 421         }
 422
 423         /*
 424          * If the resize_inode feature is set, and we are changing the
 425          * number of descriptor blocks, then adjust
 426          * s_reserved_gdt_blocks if possible to avoid needing to move
 427          * the inode table either now or in the future.
 428          */
 429         if ((fs->super->s_feature_compat &
 430              EXT2_FEATURE_COMPAT_RESIZE_INODE) &&
 431             (old_fs->desc_blocks != fs->desc_blocks)) {
 432                 int new;
 433
 434                 new = ((int) fs->super->s_reserved_gdt_blocks) +
 435                         (old_fs->desc_blocks - fs->desc_blocks);
 436                 if (new < 0)
 437                         new = 0;
 438                 if (new > (int) fs->blocksize/4)
 439                         new = fs->blocksize/4;
 440                 fs->super->s_reserved_gdt_blocks = new;
 441         }
 442
 443         /*
 444          * If we are shrinking the number of block groups, we're done
 445          * and can exit now.
 446          */
 447         if (old_fs->group_desc_count > fs->group_desc_count) {
 448                 /*
 449                  * Check the block groups that we are chopping off
 450                  * and free any blocks associated with their metadata
 451                  */
 452                 for (i = fs->group_desc_count;
 453                      i < old_fs->group_desc_count; i++) {
 454                         free_gdp_blocks(fs, reserve_blocks,
 455                                         ext2fs_group_desc(old_fs,
 456                                                 old_fs->group_desc, i));
 457                 }
 458                 retval = 0;
 459                 goto errout;
 460         }
 461
 462         /*
 463          * Fix the count of the last (old) block group
 464          */
 465         old_numblocks = (ext2fs_blocks_count(old_fs->super) -
 466                          old_fs->super->s_first_data_block) %
 467                                  old_fs->super->s_blocks_per_group;
 468         if (!old_numblocks)
 469                 old_numblocks = old_fs->super->s_blocks_per_group;
 470         if (old_fs->group_desc_count == fs->group_desc_count) {
 471                 numblocks = (ext2fs_blocks_count(fs->super) -
 472                              fs->super->s_first_data_block) %
 473                         fs->super->s_blocks_per_group;
 474                 if (!numblocks)
 475                         numblocks = fs->super->s_blocks_per_group;
 476         } else
 477                 numblocks = fs->super->s_blocks_per_group;
 478         i = old_fs->group_desc_count - 1;
 479         ext2fs_bg_free_blocks_count_set(fs, i, ext2fs_bg_free_blocks_count(fs, i) + (numblocks - old_numblocks));
 480         ext2fs_group_desc_csum_set(fs, i);
 481
 482         /*
 483          * If the number of block groups is staying the same, we're
 484          * done and can exit now.  (If the number block groups is
 485          * shrinking, we had exited earlier.)
 486          */
 487         if (old_fs->group_desc_count >= fs->group_desc_count) {
 488                 retval = 0;
 489                 goto errout;
 490         }
 491
 492         /*
 493          * Initialize the new block group descriptors
 494          */
 495         group_block = ext2fs_group_first_block2(fs,
 496                                                 old_fs->group_desc_count);
 497         csum_flag = EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 498                                                EXT4_FEATURE_RO_COMPAT_GDT_CSUM);
 499         if (access("/sys/fs/ext4/features/lazy_itable_init", F_OK) == 0)
 500                 lazy_itable_init = 1;
 501         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
 502                 old_desc_blocks = fs->super->s_first_meta_bg;
 503         else
 504                 old_desc_blocks = fs->desc_blocks +
 505                         fs->super->s_reserved_gdt_blocks;
 506         for (i = old_fs->group_desc_count;
 507              i < fs->group_desc_count; i++) {
 508                 memset(ext2fs_group_desc(fs, fs->group_desc, i), 0,
 509                        sizeof(struct ext2_group_desc));
 510                 adjblocks = 0;
 511
 512                 ext2fs_bg_flags_zap(fs, i);
 513                 if (csum_flag) {
 514                         ext2fs_bg_flags_set(fs, i, EXT2_BG_INODE_UNINIT);
 515                         if (!lazy_itable_init)
 516                                 ext2fs_bg_flags_set(fs, i,
 517                                                     EXT2_BG_INODE_ZEROED);
 518                         ext2fs_bg_itable_unused_set(fs, i,
 519                                         fs->super->s_inodes_per_group);
 520                 }
 521
 522                 numblocks = ext2fs_group_blocks_count(fs, i);
 523                 if ((i < fs->group_desc_count - 1) && csum_flag)
 524                         ext2fs_bg_flags_set(fs, i, EXT2_BG_BLOCK_UNINIT);
 525
 526                 has_super = ext2fs_bg_has_super(fs, i);
 527                 if (has_super) {
 528                         ext2fs_block_alloc_stats2(fs, group_block, +1);
 529                         adjblocks++;
 530                 }
 531                 meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
 532                 meta_bg = i / meta_bg_size;
 533                 if (!(fs->super->s_feature_incompat &
 534                       EXT2_FEATURE_INCOMPAT_META_BG) ||
 535                     (meta_bg < fs->super->s_first_meta_bg)) {
 536                         if (has_super) {
 537                                 for (j=0; j < old_desc_blocks; j++)
 538                                         ext2fs_block_alloc_stats2(fs,
 539                                                  group_block + 1 + j, +1);
 540                                 adjblocks += old_desc_blocks;
 541                         }
 542                 } else {
 543                         if (has_super)
 544                                 has_super = 1;
 545                         if (((i % meta_bg_size) == 0) ||
 546                             ((i % meta_bg_size) == 1) ||
 547                             ((i % meta_bg_size) == (meta_bg_size-1)))
 548                                 ext2fs_block_alloc_stats2(fs,
 549                                                  group_block + has_super, +1);
 550                 }
 551
 552                 adjblocks += 2 + fs->inode_blocks_per_group;
 553
 554                 numblocks -= adjblocks;
 555                 ext2fs_free_blocks_count_set(fs->super,
 556                              ext2fs_free_blocks_count(fs->super) - adjblocks);
 557                 fs->super->s_free_inodes_count +=
 558                         fs->super->s_inodes_per_group;
 559                 ext2fs_bg_free_blocks_count_set(fs, i, numblocks);
 560                 ext2fs_bg_free_inodes_count_set(fs, i,
 561                                                 fs->super->s_inodes_per_group);
 562                 ext2fs_bg_used_dirs_count_set(fs, i, 0);
 563                 ext2fs_group_desc_csum_set(fs, i);
 564
 565                 retval = ext2fs_allocate_group_table(fs, i, 0);
 566                 if (retval) goto errout;
 567
 568                 group_block += fs->super->s_blocks_per_group;
 569         }
 570         retval = 0;
 571
 572 errout:
 573         return (retval);
 574 }
 575
 576 /*
 577  * This routine adjusts the superblock and other data structures, both
 578  * in disk as well as in memory...
 579  */
 580 static errcode_t adjust_superblock(ext2_resize_t rfs, blk64_t new_size)
 581 {
 582         ext2_filsys fs;
 583         int             adj = 0;
 584         errcode_t       retval;
 585         blk64_t         group_block;
 586         unsigned long   i;
 587         unsigned long   max_group;
 588
 589         fs = rfs->new_fs;
 590         ext2fs_mark_super_dirty(fs);
 591         ext2fs_mark_bb_dirty(fs);
 592         ext2fs_mark_ib_dirty(fs);
 593
 594         retval = ext2fs_allocate_block_bitmap(fs, _("reserved blocks"),
 595                                               &rfs->reserve_blocks);
 596         if (retval)
 597                 return retval;
 598
 599         retval = adjust_fs_info(fs, rfs->old_fs, rfs->reserve_blocks, new_size);
 600         if (retval)
 601                 goto errout;
 602
 603         /*
 604          * Check to make sure there are enough inodes
 605          */
 606         if ((rfs->old_fs->super->s_inodes_count -
 607              rfs->old_fs->super->s_free_inodes_count) >
 608             rfs->new_fs->super->s_inodes_count) {
 609                 retval = ENOSPC;
 610                 goto errout;
 611         }
 612
 613         /*
 614          * If we are shrinking the number block groups, we're done and
 615          * can exit now.
 616          */
 617         if (rfs->old_fs->group_desc_count > fs->group_desc_count) {
 618                 retval = 0;
 619                 goto errout;
 620         }
 621
 622         /*
 623          * If the number of block groups is staying the same, we're
 624          * done and can exit now.  (If the number block groups is
 625          * shrinking, we had exited earlier.)
 626          */
 627         if (rfs->old_fs->group_desc_count >= fs->group_desc_count) {
 628                 retval = 0;
 629                 goto errout;
 630         }
 631
 632         /*
 633          * If we are using uninit_bg (aka GDT_CSUM) and the kernel
 634          * supports lazy inode initialization, we can skip
 635          * initializing the inode table.
 636          */
 637         if (lazy_itable_init &&
 638             EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 639                                        EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
 640                 retval = 0;
 641                 goto errout;
 642         }
 643
 644         /*
 645          * Initialize the inode table
 646          */
 647         retval = ext2fs_get_array(fs->blocksize, fs->inode_blocks_per_group,
 648                                 &rfs->itable_buf);
 649         if (retval)
 650                 goto errout;
 651
 652         memset(rfs->itable_buf, 0, fs->blocksize * fs->inode_blocks_per_group);
 653         group_block = ext2fs_group_first_block2(fs,
 654                                                 rfs->old_fs->group_desc_count);
 655         adj = rfs->old_fs->group_desc_count;
 656         max_group = fs->group_desc_count - adj;
 657         if (rfs->progress) {
 658                 retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
 659                                        0, max_group);
 660                 if (retval)
 661                         goto errout;
 662         }
 663         for (i = rfs->old_fs->group_desc_count;
 664              i < fs->group_desc_count; i++) {
 665                 /*
 666                  * Write out the new inode table
 667                  */
 668                 retval = io_channel_write_blk64(fs->io,
 669                                                 ext2fs_inode_table_loc(fs, i),
 670                                                 fs->inode_blocks_per_group,
 671                                                 rfs->itable_buf);
 672                 if (retval) goto errout;
 673
 674                 io_channel_flush(fs->io);
 675                 if (rfs->progress) {
 676                         retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
 677                                                i - adj + 1, max_group);
 678                         if (retval)
 679                                 goto errout;
 680                 }
 681                 group_block += fs->super->s_blocks_per_group;
 682         }
 683         io_channel_flush(fs->io);
 684         retval = 0;
 685
 686 errout:
 687         return retval;
 688 }
 689
 690 /* --------------------------------------------------------------------
 691  *
 692  * Resize processing, phase 2.
 693  *
 694  * In this phase we adjust determine which blocks need to be moved, in
 695  * blocks_to_move().  We then copy the blocks to their ultimate new
 696  * destinations using block_mover().  Since we are copying blocks to
 697  * their new locations, again during this pass we can abort without
 698  * any problems.
 699  * --------------------------------------------------------------------
 700  */
 701
 702 /*
 703  * This helper function creates a block bitmap with all of the
 704  * filesystem meta-data blocks.
 705  */
 706 static errcode_t mark_table_blocks(ext2_filsys fs,
 707                                    ext2fs_block_bitmap bmap)
 708 {
 709         dgrp_t                  i;
 710
 711         for (i = 0; i < fs->group_desc_count; i++) {
 712                 ext2fs_reserve_super_and_bgd(fs, i, bmap);
 713
 714                 /*
 715                  * Mark the blocks used for the inode table
 716                  */
 717                 ext2fs_mark_block_bitmap_range2(bmap,
 718                                           ext2fs_inode_table_loc(fs, i),
 719                                           fs->inode_blocks_per_group);
 720
 721                 /*
 722                  * Mark block used for the block bitmap
 723                  */
 724                 ext2fs_mark_block_bitmap2(bmap,
 725                                          ext2fs_block_bitmap_loc(fs, i));
 726
 727                 /*
 728                  * Mark block used for the inode bitmap
 729                  */
 730                 ext2fs_mark_block_bitmap2(bmap,
 731                                          ext2fs_inode_bitmap_loc(fs, i));
 732         }
 733         return 0;
 734 }
 735
 736 /*
 737  * This function checks to see if a particular block (either a
 738  * superblock or a block group descriptor) overlaps with an inode or
 739  * block bitmap block, or with the inode table.
 740  */
 741 static void mark_fs_metablock(ext2_resize_t rfs,
 742                               ext2fs_block_bitmap meta_bmap,
 743                               int group, blk64_t blk)
 744 {
 745         ext2_filsys     fs = rfs->new_fs;
 746
 747         ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
 748         ext2fs_block_alloc_stats2(fs, blk, +1);
 749
 750         /*
 751          * Check to see if we overlap with the inode or block bitmap,
 752          * or the inode tables.  If not, and the block is in use, then
 753          * mark it as a block to be moved.
 754          */
 755         if (IS_BLOCK_BM(fs, group, blk)) {
 756                 ext2fs_block_bitmap_loc_set(fs, group, 0);
 757                 rfs->needed_blocks++;
 758                 return;
 759         }
 760         if (IS_INODE_BM(fs, group, blk)) {
 761                 ext2fs_inode_bitmap_loc_set(fs, group, 0);
 762                 rfs->needed_blocks++;
 763                 return;
 764         }
 765         if (IS_INODE_TB(fs, group, blk)) {
 766                 ext2fs_inode_table_loc_set(fs, group, 0);
 767                 rfs->needed_blocks++;
 768                 return;
 769         }
 770         if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_FLEX_BG) {
 771                 dgrp_t i;
 772
 773                 for (i=0; i < rfs->old_fs->group_desc_count; i++) {
 774                         if (IS_BLOCK_BM(fs, i, blk)) {
 775                                 ext2fs_block_bitmap_loc_set(fs, i, 0);
 776                                 rfs->needed_blocks++;
 777                                 return;
 778                         }
 779                         if (IS_INODE_BM(fs, i, blk)) {
 780                                 ext2fs_inode_bitmap_loc_set(fs, i, 0);
 781                                 rfs->needed_blocks++;
 782                                 return;
 783                         }
 784                         if (IS_INODE_TB(fs, i, blk)) {
 785                                 ext2fs_inode_table_loc_set(fs, i, 0);
 786                                 rfs->needed_blocks++;
 787                                 return;
 788                         }
 789                 }
 790         }
 791         if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 792                                        EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
 793                    (ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT))) {
 794                 /*
 795                  * If the block bitmap is uninitialized, which means
 796                  * nothing other than standard metadata in use.
 797                  */
 798                 return;
 799         } else if (ext2fs_test_block_bitmap2(rfs->old_fs->block_map, blk) &&
 800                    !ext2fs_test_block_bitmap2(meta_bmap, blk)) {
 801                 ext2fs_mark_block_bitmap2(rfs->move_blocks, blk);
 802                 rfs->needed_blocks++;
 803         }
 804 }
 805
 806
 807 /*
 808  * This routine marks and unmarks reserved blocks in the new block
 809  * bitmap.  It also determines which blocks need to be moved and
 810  * places this information into the move_blocks bitmap.
 811  */
 812 static errcode_t blocks_to_move(ext2_resize_t rfs)
 813 {
 814         int             j, has_super;
 815         dgrp_t          i, max_groups, g;
 816         blk64_t         blk, group_blk;
 817         blk64_t         old_blocks, new_blocks;
 818         unsigned int    meta_bg, meta_bg_size;
 819         errcode_t       retval;
 820         ext2_filsys     fs, old_fs;
 821         ext2fs_block_bitmap     meta_bmap;
 822         int             flex_bg;
 823
 824         fs = rfs->new_fs;
 825         old_fs = rfs->old_fs;
 826         if (ext2fs_blocks_count(old_fs->super) > ext2fs_blocks_count(fs->super))
 827                 fs = rfs->old_fs;
 828
 829         retval = ext2fs_allocate_block_bitmap(fs, _("blocks to be moved"),
 830                                               &rfs->move_blocks);
 831         if (retval)
 832                 return retval;
 833
 834         retval = ext2fs_allocate_block_bitmap(fs, _("meta-data blocks"),
 835                                               &meta_bmap);
 836         if (retval)
 837                 return retval;
 838
 839         retval = mark_table_blocks(old_fs, meta_bmap);
 840         if (retval)
 841                 return retval;
 842
 843         fs = rfs->new_fs;
 844
 845         /*
 846          * If we're shrinking the filesystem, we need to move all of
 847          * the blocks that don't fit any more
 848          */
 849         for (blk = ext2fs_blocks_count(fs->super);
 850              blk < ext2fs_blocks_count(old_fs->super); blk++) {
 851                 g = ext2fs_group_of_blk2(fs, blk);
 852                 if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 853                                                EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
 854                     ext2fs_bg_flags_test(old_fs, g, EXT2_BG_BLOCK_UNINIT)) {
 855                         /*
 856                          * The block bitmap is uninitialized, so skip
 857                          * to the next block group.
 858                          */
 859                         blk = ext2fs_group_first_block2(fs, g+1) - 1;
 860                         continue;
 861                 }
 862                 if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
 863                     !ext2fs_test_block_bitmap2(meta_bmap, blk)) {
 864                         ext2fs_mark_block_bitmap2(rfs->move_blocks, blk);
 865                         rfs->needed_blocks++;
 866                 }
 867                 ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
 868         }
 869
 870         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) {
 871                 old_blocks = old_fs->super->s_first_meta_bg;
 872                 new_blocks = fs->super->s_first_meta_bg;
 873         } else {
 874                 old_blocks = old_fs->desc_blocks + old_fs->super->s_reserved_gdt_blocks;
 875                 new_blocks = fs->desc_blocks + fs->super->s_reserved_gdt_blocks;
 876         }
 877
 878         if (old_blocks == new_blocks) {
 879                 retval = 0;
 880                 goto errout;
 881         }
 882
 883         max_groups = fs->group_desc_count;
 884         if (max_groups > old_fs->group_desc_count)
 885                 max_groups = old_fs->group_desc_count;
 886         group_blk = old_fs->super->s_first_data_block;
 887         /*
 888          * If we're reducing the number of descriptor blocks, this
 889          * makes life easy.  :-)   We just have to mark some extra
 890          * blocks as free.
 891          */
 892         if (old_blocks > new_blocks) {
 893                 for (i = 0; i < max_groups; i++) {
 894                         if (!ext2fs_bg_has_super(fs, i)) {
 895                                 group_blk += fs->super->s_blocks_per_group;
 896                                 continue;
 897                         }
 898                         for (blk = group_blk+1+new_blocks;
 899                              blk < group_blk+1+old_blocks; blk++) {
 900                                 ext2fs_block_alloc_stats2(fs, blk, -1);
 901                                 rfs->needed_blocks--;
 902                         }
 903                         group_blk += fs->super->s_blocks_per_group;
 904                 }
 905                 retval = 0;
 906                 goto errout;
 907         }
 908         /*
 909          * If we're increasing the number of descriptor blocks, life
 910          * gets interesting....
 911          */
 912         meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
 913         flex_bg = fs->super->s_feature_incompat &
 914                 EXT4_FEATURE_INCOMPAT_FLEX_BG;
 915         /* first reserve all of the existing fs meta blocks */
 916         for (i = 0; i < max_groups; i++) {
 917                 has_super = ext2fs_bg_has_super(fs, i);
 918                 if (has_super)
 919                         mark_fs_metablock(rfs, meta_bmap, i, group_blk);
 920
 921                 meta_bg = i / meta_bg_size;
 922                 if (!(fs->super->s_feature_incompat &
 923                       EXT2_FEATURE_INCOMPAT_META_BG) ||
 924                     (meta_bg < fs->super->s_first_meta_bg)) {
 925                         if (has_super) {
 926                                 for (blk = group_blk+1;
 927                                      blk < group_blk + 1 + new_blocks; blk++)
 928                                         mark_fs_metablock(rfs, meta_bmap,
 929                                                           i, blk);
 930                         }
 931                 } else {
 932                         if (has_super)
 933                                 has_super = 1;
 934                         if (((i % meta_bg_size) == 0) ||
 935                             ((i % meta_bg_size) == 1) ||
 936                             ((i % meta_bg_size) == (meta_bg_size-1)))
 937                                 mark_fs_metablock(rfs, meta_bmap, i,
 938                                                   group_blk + has_super);
 939                 }
 940
 941                 /*
 942                  * Reserve the existing meta blocks that we know
 943                  * aren't to be moved.
 944                  *
 945                  * For flex_bg file systems, in order to avoid
 946                  * overwriting fs metadata (especially inode table
 947                  * blocks) belonging to a different block group when
 948                  * we are relocating the inode tables, we need to
 949                  * reserve all existing fs metadata blocks.
 950                  */
 951                 if (ext2fs_block_bitmap_loc(fs, i))
 952                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
 953                                  ext2fs_block_bitmap_loc(fs, i));
 954                 else if (flex_bg && i < old_fs->group_desc_count)
 955                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
 956                                  ext2fs_block_bitmap_loc(old_fs, i));
 957
 958                 if (ext2fs_inode_bitmap_loc(fs, i))
 959                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
 960                                  ext2fs_inode_bitmap_loc(fs, i));
 961                 else if (flex_bg && i < old_fs->group_desc_count)
 962                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
 963                                  ext2fs_inode_bitmap_loc(old_fs, i));
 964
 965                 if (ext2fs_inode_table_loc(fs, i))
 966                         ext2fs_mark_block_bitmap_range2(rfs->reserve_blocks,
 967                                         ext2fs_inode_table_loc(fs, i),
 968                                         fs->inode_blocks_per_group);
 969                 else if (flex_bg && i < old_fs->group_desc_count)
 970                         ext2fs_mark_block_bitmap_range2(rfs->reserve_blocks,
 971                                         ext2fs_inode_table_loc(old_fs, i),
 972                                         old_fs->inode_blocks_per_group);
 973
 974                 group_blk += rfs->new_fs->super->s_blocks_per_group;
 975         }
 976
 977         /* Allocate the missing data structures */
 978         for (i = 0; i < max_groups; i++) {
 979                 if (ext2fs_inode_table_loc(fs, i) &&
 980                     ext2fs_inode_bitmap_loc(fs, i) &&
 981                     ext2fs_block_bitmap_loc(fs, i))
 982                         continue;
 983
 984                 retval = ext2fs_allocate_group_table(fs, i,
 985                                                      rfs->reserve_blocks);
 986                 if (retval)
 987                         goto errout;
 988
 989                 /*
 990                  * For those structures that have changed, we need to
 991                  * do bookkeepping.
 992                  */
 993                 if (ext2fs_block_bitmap_loc(old_fs, i) !=
 994                     (blk = ext2fs_block_bitmap_loc(fs, i))) {
 995                         ext2fs_block_alloc_stats2(fs, blk, +1);
 996                         if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
 997                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
 998                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
 999                                                          blk);
1000                 }
1001                 if (ext2fs_inode_bitmap_loc(old_fs, i) !=
1002                     (blk = ext2fs_inode_bitmap_loc(fs, i))) {
1003                         ext2fs_block_alloc_stats2(fs, blk, +1);
1004                         if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
1005                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
1006                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
1007                                                          blk);
1008                 }
1009
1010                 /*
1011                  * The inode table, if we need to relocate it, is
1012                  * handled specially.  We have to reserve the blocks
1013                  * for both the old and the new inode table, since we
1014                  * can't have the inode table be destroyed during the
1015                  * block relocation phase.
1016                  */
1017                 if (ext2fs_inode_table_loc(fs, i) == ext2fs_inode_table_loc(old_fs, i))
1018                         continue;       /* inode table not moved */
1019
1020                 rfs->needed_blocks += fs->inode_blocks_per_group;
1021
1022                 /*
1023                  * Mark the new inode table as in use in the new block
1024                  * allocation bitmap, and move any blocks that might
1025                  * be necessary.
1026                  */
1027                 for (blk = ext2fs_inode_table_loc(fs, i), j=0;
1028                      j < fs->inode_blocks_per_group ; j++, blk++) {
1029                         ext2fs_block_alloc_stats2(fs, blk, +1);
1030                         if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
1031                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
1032                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
1033                                                          blk);
1034                 }
1035
1036                 /*
1037                  * Make sure the old inode table is reserved in the
1038                  * block reservation bitmap.
1039                  */
1040                 for (blk = ext2fs_inode_table_loc(rfs->old_fs, i), j=0;
1041                      j < fs->inode_blocks_per_group ; j++, blk++)
1042                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
1043         }
1044         retval = 0;
1045
1046 errout:
1047         if (meta_bmap)
1048                 ext2fs_free_block_bitmap(meta_bmap);
1049
1050         return retval;
1051 }
1052
1053 /*
1054  * This helper function tries to allocate a new block.  We try to
1055  * avoid hitting the original group descriptor blocks at least at
1056  * first, since we want to make it possible to recover from a badly
1057  * aborted resize operation as much as possible.
1058  *
1059  * In the future, I may further modify this routine to balance out
1060  * where we get the new blocks across the various block groups.
1061  * Ideally we would allocate blocks that corresponded with the block
1062  * group of the containing inode, and keep contiguous blocks
1063  * together.  However, this very difficult to do efficiently, since we
1064  * don't have the necessary information up front.
1065  */
1066
1067 #define AVOID_OLD       1
1068 #define DESPERATION     2
1069
1070 static void init_block_alloc(ext2_resize_t rfs)
1071 {
1072         rfs->alloc_state = AVOID_OLD;
1073         rfs->new_blk = rfs->new_fs->super->s_first_data_block;
1074 #if 0
1075         /* HACK for testing */
1076         if (ext2fs_blocks_count(rfs->new_fs->super) >
1077             ext2fs_blocks_count(rfs->old_fs->super))
1078                 rfs->new_blk = ext2fs_blocks_count(rfs->old_fs->super);
1079 #endif
1080 }
1081
1082 static blk64_t get_new_block(ext2_resize_t rfs)
1083 {
1084         ext2_filsys     fs = rfs->new_fs;
1085
1086         while (1) {
1087                 if (rfs->new_blk >= ext2fs_blocks_count(fs->super)) {
1088                         if (rfs->alloc_state == DESPERATION)
1089                                 return 0;
1090
1091 #ifdef RESIZE2FS_DEBUG
1092                         if (rfs->flags & RESIZE_DEBUG_BMOVE)
1093                                 printf("Going into desperation mode "
1094                                        "for block allocations\n");
1095 #endif
1096                         rfs->alloc_state = DESPERATION;
1097                         rfs->new_blk = fs->super->s_first_data_block;
1098                         continue;
1099                 }
1100                 if (ext2fs_test_block_bitmap2(fs->block_map, rfs->new_blk) ||
1101                     ext2fs_test_block_bitmap2(rfs->reserve_blocks,
1102                                              rfs->new_blk) ||
1103                     ((rfs->alloc_state == AVOID_OLD) &&
1104                      (rfs->new_blk < ext2fs_blocks_count(rfs->old_fs->super)) &&
1105                      ext2fs_test_block_bitmap2(rfs->old_fs->block_map,
1106                                               rfs->new_blk))) {
1107                         rfs->new_blk++;
1108                         continue;
1109                 }
1110                 return rfs->new_blk;
1111         }
1112 }
1113
1114 static errcode_t resize2fs_get_alloc_block(ext2_filsys fs, blk64_t goal,
1115                                            blk64_t *ret)
1116 {
1117         ext2_resize_t rfs = (ext2_resize_t) fs->priv_data;
1118         blk64_t blk;
1119
1120         blk = get_new_block(rfs);
1121         if (!blk)
1122                 return ENOSPC;
1123
1124 #ifdef RESIZE2FS_DEBUG
1125         if (rfs->flags & 0xF)
1126                 printf("get_alloc_block allocating %llu\n", blk);
1127 #endif
1128
1129         ext2fs_mark_block_bitmap2(rfs->old_fs->block_map, blk);
1130         ext2fs_mark_block_bitmap2(rfs->new_fs->block_map, blk);
1131         *ret = (blk64_t) blk;
1132         return 0;
1133 }
1134
1135 static errcode_t block_mover(ext2_resize_t rfs)
1136 {
1137         blk64_t                 blk, old_blk, new_blk;
1138         ext2_filsys             fs = rfs->new_fs;
1139         ext2_filsys             old_fs = rfs->old_fs;
1140         errcode_t               retval;
1141         __u64                   size;
1142         int                     c;
1143         int                     to_move, moved;
1144         ext2_badblocks_list     badblock_list = 0;
1145         int                     bb_modified = 0;
1146
1147         fs->get_alloc_block = resize2fs_get_alloc_block;
1148         old_fs->get_alloc_block = resize2fs_get_alloc_block;
1149
1150         retval = ext2fs_read_bb_inode(old_fs, &badblock_list);
1151         if (retval)
1152                 return retval;
1153
1154         new_blk = fs->super->s_first_data_block;
1155         if (!rfs->itable_buf) {
1156                 retval = ext2fs_get_array(fs->blocksize,
1157                                         fs->inode_blocks_per_group,
1158                                         &rfs->itable_buf);
1159                 if (retval)
1160                         return retval;
1161         }
1162         retval = ext2fs_create_extent_table(&rfs->bmap, 0);
1163         if (retval)
1164                 return retval;
1165
1166         /*
1167          * The first step is to figure out where all of the blocks
1168          * will go.
1169          */
1170         to_move = moved = 0;
1171         init_block_alloc(rfs);
1172         for (blk = old_fs->super->s_first_data_block;
1173              blk < ext2fs_blocks_count(old_fs->super); blk++) {
1174                 if (!ext2fs_test_block_bitmap2(old_fs->block_map, blk))
1175                         continue;
1176                 if (!ext2fs_test_block_bitmap2(rfs->move_blocks, blk))
1177                         continue;
1178                 if (ext2fs_badblocks_list_test(badblock_list, blk)) {
1179                         ext2fs_badblocks_list_del(badblock_list, blk);
1180                         bb_modified++;
1181                         continue;
1182                 }
1183
1184                 new_blk = get_new_block(rfs);
1185                 if (!new_blk) {
1186                         retval = ENOSPC;
1187                         goto errout;
1188                 }
1189                 ext2fs_block_alloc_stats2(fs, new_blk, +1);
1190                 ext2fs_add_extent_entry(rfs->bmap, blk, new_blk);
1191                 to_move++;
1192         }
1193
1194         if (to_move == 0) {
1195                 if (rfs->bmap) {
1196                         ext2fs_free_extent_table(rfs->bmap);
1197                         rfs->bmap = 0;
1198                 }
1199                 retval = 0;
1200                 goto errout;
1201         }
1202
1203         /*
1204          * Step two is to actually move the blocks
1205          */
1206         retval =  ext2fs_iterate_extent(rfs->bmap, 0, 0, 0);
1207         if (retval) goto errout;
1208
1209         if (rfs->progress) {
1210                 retval = (rfs->progress)(rfs, E2_RSZ_BLOCK_RELOC_PASS,
1211                                          0, to_move);
1212                 if (retval)
1213                         goto errout;
1214         }
1215         while (1) {
1216                 retval = ext2fs_iterate_extent(rfs->bmap, &old_blk, &new_blk, &size);
1217                 if (retval) goto errout;
1218                 if (!size)
1219                         break;
1220 #ifdef RESIZE2FS_DEBUG
1221                 if (rfs->flags & RESIZE_DEBUG_BMOVE)
1222                         printf("Moving %llu blocks %llu->%llu\n",
1223                                size, old_blk, new_blk);
1224 #endif
1225                 do {
1226                         c = size;
1227                         if (c > fs->inode_blocks_per_group)
1228                                 c = fs->inode_blocks_per_group;
1229                         retval = io_channel_read_blk64(fs->io, old_blk, c,
1230                                                        rfs->itable_buf);
1231                         if (retval) goto errout;
1232                         retval = io_channel_write_blk64(fs->io, new_blk, c,
1233                                                         rfs->itable_buf);
1234                         if (retval) goto errout;
1235                         size -= c;
1236                         new_blk += c;
1237                         old_blk += c;
1238                         moved += c;
1239                         if (rfs->progress) {
1240                                 io_channel_flush(fs->io);
1241                                 retval = (rfs->progress)(rfs,
1242                                                 E2_RSZ_BLOCK_RELOC_PASS,
1243                                                 moved, to_move);
1244                                 if (retval)
1245                                         goto errout;
1246                         }
1247                 } while (size > 0);
1248                 io_channel_flush(fs->io);
1249         }
1250
1251 errout:
1252         if (badblock_list) {
1253                 if (!retval && bb_modified)
1254                         retval = ext2fs_update_bb_inode(old_fs,
1255                                                         badblock_list);
1256                 ext2fs_badblocks_list_free(badblock_list);
1257         }
1258         return retval;
1259 }
1260
1261
1262 /* --------------------------------------------------------------------
1263  *
1264  * Resize processing, phase 3
1265  *
1266  * --------------------------------------------------------------------
1267  */
1268
1269
1270 struct process_block_struct {
1271         ext2_resize_t           rfs;
1272         ext2_ino_t              ino;
1273         struct ext2_inode *     inode;
1274         errcode_t               error;
1275         int                     is_dir;
1276         int                     changed;
1277 };
1278
1279 static int process_block(ext2_filsys fs, blk64_t        *block_nr,
1280                          e2_blkcnt_t blockcnt,
1281                          blk64_t ref_block EXT2FS_ATTR((unused)),
1282                          int ref_offset EXT2FS_ATTR((unused)), void *priv_data)
1283 {
1284         struct process_block_struct *pb;
1285         errcode_t       retval;
1286         blk64_t         block, new_block;
1287         int             ret = 0;
1288
1289         pb = (struct process_block_struct *) priv_data;
1290         block = *block_nr;
1291         if (pb->rfs->bmap) {
1292                 new_block = ext2fs_extent_translate(pb->rfs->bmap, block);
1293                 if (new_block) {
1294                         *block_nr = new_block;
1295                         ret |= BLOCK_CHANGED;
1296                         pb->changed = 1;
1297 #ifdef RESIZE2FS_DEBUG
1298                         if (pb->rfs->flags & RESIZE_DEBUG_BMOVE)
1299                                 printf("ino=%u, blockcnt=%lld, %llu->%llu\n",
1300                                        pb->ino, blockcnt, block, new_block);
1301 #endif
1302                         block = new_block;
1303                 }
1304         }
1305         if (pb->is_dir) {
1306                 retval = ext2fs_add_dir_block2(fs->dblist, pb->ino,
1307                                                block, (int) blockcnt);
1308                 if (retval) {
1309                         pb->error = retval;
1310                         ret |= BLOCK_ABORT;
1311                 }
1312         }
1313         return ret;
1314 }
1315
1316 /*
1317  * Progress callback
1318  */
1319 static errcode_t progress_callback(ext2_filsys fs,
1320                                    ext2_inode_scan scan EXT2FS_ATTR((unused)),
1321                                    dgrp_t group, void * priv_data)
1322 {
1323         ext2_resize_t rfs = (ext2_resize_t) priv_data;
1324         errcode_t               retval;
1325
1326         /*
1327          * This check is to protect against old ext2 libraries.  It
1328          * shouldn't be needed against new libraries.
1329          */
1330         if ((group+1) == 0)
1331                 return 0;
1332
1333         if (rfs->progress) {
1334                 io_channel_flush(fs->io);
1335                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
1336                                          group+1, fs->group_desc_count);
1337                 if (retval)
1338                         return retval;
1339         }
1340
1341         return 0;
1342 }
1343
1344 static errcode_t inode_scan_and_fix(ext2_resize_t rfs)
1345 {
1346         struct process_block_struct     pb;
1347         ext2_ino_t              ino, new_inode;
1348         struct ext2_inode       *inode = NULL;
1349         ext2_inode_scan         scan = NULL;
1350         errcode_t               retval;
1351         char                    *block_buf = 0;
1352         ext2_ino_t              start_to_move;
1353         blk64_t                 orig_size;
1354         blk64_t                 new_block;
1355         int                     inode_size;
1356
1357         if ((rfs->old_fs->group_desc_count <=
1358              rfs->new_fs->group_desc_count) &&
1359             !rfs->bmap)
1360                 return 0;
1361
1362         /*
1363          * Save the original size of the old filesystem, and
1364          * temporarily set the size to be the new size if the new size
1365          * is larger.  We need to do this to avoid catching an error
1366          * by the block iterator routines
1367          */
1368         orig_size = ext2fs_blocks_count(rfs->old_fs->super);
1369         if (orig_size < ext2fs_blocks_count(rfs->new_fs->super))
1370                 ext2fs_blocks_count_set(rfs->old_fs->super,
1371                                 ext2fs_blocks_count(rfs->new_fs->super));
1372
1373         retval = ext2fs_open_inode_scan(rfs->old_fs, 0, &scan);
1374         if (retval) goto errout;
1375
1376         retval = ext2fs_init_dblist(rfs->old_fs, 0);
1377         if (retval) goto errout;
1378         retval = ext2fs_get_array(rfs->old_fs->blocksize, 3, &block_buf);
1379         if (retval) goto errout;
1380
1381         start_to_move = (rfs->new_fs->group_desc_count *
1382                          rfs->new_fs->super->s_inodes_per_group);
1383
1384         if (rfs->progress) {
1385                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
1386                                          0, rfs->old_fs->group_desc_count);
1387                 if (retval)
1388                         goto errout;
1389         }
1390         ext2fs_set_inode_callback(scan, progress_callback, (void *) rfs);
1391         pb.rfs = rfs;
1392         pb.inode = inode;
1393         pb.error = 0;
1394         new_inode = EXT2_FIRST_INODE(rfs->new_fs->super);
1395         inode_size = EXT2_INODE_SIZE(rfs->new_fs->super);
1396         inode = malloc(inode_size);
1397         if (!inode) {
1398                 retval = ENOMEM;
1399                 goto errout;
1400         }
1401         /*
1402          * First, copy all of the inodes that need to be moved
1403          * elsewhere in the inode table
1404          */
1405         while (1) {
1406                 retval = ext2fs_get_next_inode_full(scan, &ino, inode, inode_size);
1407                 if (retval) goto errout;
1408                 if (!ino)
1409                         break;
1410
1411                 if (inode->i_links_count == 0 && ino != EXT2_RESIZE_INO)
1412                         continue; /* inode not in use */
1413
1414                 pb.is_dir = LINUX_S_ISDIR(inode->i_mode);
1415                 pb.changed = 0;
1416
1417                 if (ext2fs_file_acl_block(rfs->old_fs, inode) && rfs->bmap) {
1418                         new_block = ext2fs_extent_translate(rfs->bmap,
1419                                 ext2fs_file_acl_block(rfs->old_fs, inode));
1420                         if (new_block) {
1421                                 ext2fs_file_acl_block_set(rfs->old_fs, inode,
1422                                                           new_block);
1423                                 retval = ext2fs_write_inode_full(rfs->old_fs,
1424                                                             ino, inode, inode_size);
1425                                 if (retval) goto errout;
1426                         }
1427                 }
1428
1429                 if (ext2fs_inode_has_valid_blocks2(rfs->old_fs, inode) &&
1430                     (rfs->bmap || pb.is_dir)) {
1431                         pb.ino = ino;
1432                         retval = ext2fs_block_iterate3(rfs->old_fs,
1433                                                        ino, 0, block_buf,
1434                                                        process_block, &pb);
1435                         if (retval)
1436                                 goto errout;
1437                         if (pb.error) {
1438                                 retval = pb.error;
1439                                 goto errout;
1440                         }
1441                 }
1442
1443                 if (ino <= start_to_move)
1444                         continue; /* Don't need to move it. */
1445
1446                 /*
1447                  * Find a new inode
1448                  */
1449                 retval = ext2fs_new_inode(rfs->new_fs, 0, 0, 0, &new_inode);
1450                 if (retval)
1451                         goto errout;
1452
1453                 ext2fs_inode_alloc_stats2(rfs->new_fs, new_inode, +1,
1454                                           pb.is_dir);
1455                 if (pb.changed) {
1456                         /* Get the new version of the inode */
1457                         retval = ext2fs_read_inode_full(rfs->old_fs, ino,
1458                                                 inode, inode_size);
1459                         if (retval) goto errout;
1460                 }
1461                 inode->i_ctime = time(0);
1462                 retval = ext2fs_write_inode_full(rfs->old_fs, new_inode,
1463                                                 inode, inode_size);
1464                 if (retval) goto errout;
1465
1466 #ifdef RESIZE2FS_DEBUG
1467                 if (rfs->flags & RESIZE_DEBUG_INODEMAP)
1468                         printf("Inode moved %u->%u\n", ino, new_inode);
1469 #endif
1470                 if (!rfs->imap) {
1471                         retval = ext2fs_create_extent_table(&rfs->imap, 0);
1472                         if (retval)
1473                                 goto errout;
1474                 }
1475                 ext2fs_add_extent_entry(rfs->imap, ino, new_inode);
1476         }
1477         io_channel_flush(rfs->old_fs->io);
1478
1479 errout:
1480         ext2fs_blocks_count_set(rfs->old_fs->super, orig_size);
1481         if (rfs->bmap) {
1482                 ext2fs_free_extent_table(rfs->bmap);
1483                 rfs->bmap = 0;
1484         }
1485         if (scan)
1486                 ext2fs_close_inode_scan(scan);
1487         if (block_buf)
1488                 ext2fs_free_mem(&block_buf);
1489         free(inode);
1490         return retval;
1491 }
1492
1493 /* --------------------------------------------------------------------
1494  *
1495  * Resize processing, phase 4.
1496  *
1497  * --------------------------------------------------------------------
1498  */
1499
1500 struct istruct {
1501         ext2_resize_t rfs;
1502         errcode_t       err;
1503         unsigned int    max_dirs;
1504         unsigned int    num;
1505 };
1506
1507 static int check_and_change_inodes(ext2_ino_t dir,
1508                                    int entry EXT2FS_ATTR((unused)),
1509                                    struct ext2_dir_entry *dirent, int offset,
1510                                    int  blocksize EXT2FS_ATTR((unused)),
1511                                    char *buf EXT2FS_ATTR((unused)),
1512                                    void *priv_data)
1513 {
1514         struct istruct *is = (struct istruct *) priv_data;
1515         struct ext2_inode       inode;
1516         ext2_ino_t              new_inode;
1517         errcode_t               retval;
1518
1519         if (is->rfs->progress && offset == 0) {
1520                 io_channel_flush(is->rfs->old_fs->io);
1521                 is->err = (is->rfs->progress)(is->rfs,
1522                                               E2_RSZ_INODE_REF_UPD_PASS,
1523                                               ++is->num, is->max_dirs);
1524                 if (is->err)
1525                         return DIRENT_ABORT;
1526         }
1527
1528         if (!dirent->inode)
1529                 return 0;
1530
1531         new_inode = ext2fs_extent_translate(is->rfs->imap, dirent->inode);
1532
1533         if (!new_inode)
1534                 return 0;
1535 #ifdef RESIZE2FS_DEBUG
1536         if (is->rfs->flags & RESIZE_DEBUG_INODEMAP)
1537                 printf("Inode translate (dir=%u, name=%.*s, %u->%u)\n",
1538                        dir, dirent->name_len&0xFF, dirent->name,
1539                        dirent->inode, new_inode);
1540 #endif
1541
1542         dirent->inode = new_inode;
1543
1544         /* Update the directory mtime and ctime */
1545         retval = ext2fs_read_inode(is->rfs->old_fs, dir, &inode);
1546         if (retval == 0) {
1547                 inode.i_mtime = inode.i_ctime = time(0);
1548                 is->err = ext2fs_write_inode(is->rfs->old_fs, dir, &inode);
1549                 if (is->err)
1550                         return DIRENT_ABORT;
1551         }
1552
1553         return DIRENT_CHANGED;
1554 }
1555
1556 static errcode_t inode_ref_fix(ext2_resize_t rfs)
1557 {
1558         errcode_t               retval;
1559         struct istruct          is;
1560
1561         if (!rfs->imap)
1562                 return 0;
1563
1564         /*
1565          * Now, we iterate over all of the directories to update the
1566          * inode references
1567          */
1568         is.num = 0;
1569         is.max_dirs = ext2fs_dblist_count2(rfs->old_fs->dblist);
1570         is.rfs = rfs;
1571         is.err = 0;
1572
1573         if (rfs->progress) {
1574                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS,
1575                                          0, is.max_dirs);
1576                 if (retval)
1577                         goto errout;
1578         }
1579
1580         retval = ext2fs_dblist_dir_iterate(rfs->old_fs->dblist,
1581                                            DIRENT_FLAG_INCLUDE_EMPTY, 0,
1582                                            check_and_change_inodes, &is);
1583         if (retval)
1584                 goto errout;
1585         if (is.err) {
1586                 retval = is.err;
1587                 goto errout;
1588         }
1589
1590         if (rfs->progress && (is.num < is.max_dirs))
1591                 (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS,
1592                                 is.max_dirs, is.max_dirs);
1593
1594 errout:
1595         ext2fs_free_extent_table(rfs->imap);
1596         rfs->imap = 0;
1597         return retval;
1598 }
1599
1600
1601 /* --------------------------------------------------------------------
1602  *
1603  * Resize processing, phase 5.
1604  *
1605  * In this phase we actually move the inode table around, and then
1606  * update the summary statistics.  This is scary, since aborting here
1607  * will potentially scramble the filesystem.  (We are moving the
1608  * inode tables around in place, and so the potential for lost data,
1609  * or at the very least scrambling the mapping between filenames and
1610  * inode numbers is very high in case of a power failure here.)
1611  * --------------------------------------------------------------------
1612  */
1613
1614
1615 /*
1616  * A very scary routine --- this one moves the inode table around!!!
1617  *
1618  * After this you have to use the rfs->new_fs file handle to read and
1619  * write inodes.
1620  */
1621 static errcode_t move_itables(ext2_resize_t rfs)
1622 {
1623         int             n, num, size;
1624         long long       diff;
1625         dgrp_t          i, max_groups;
1626         ext2_filsys     fs = rfs->new_fs;
1627         char            *cp;
1628         blk64_t         old_blk, new_blk, blk;
1629         errcode_t       retval;
1630         int             j, to_move, moved;
1631
1632         max_groups = fs->group_desc_count;
1633         if (max_groups > rfs->old_fs->group_desc_count)
1634                 max_groups = rfs->old_fs->group_desc_count;
1635
1636         size = fs->blocksize * fs->inode_blocks_per_group;
1637         if (!rfs->itable_buf) {
1638                 retval = ext2fs_get_mem(size, &rfs->itable_buf);
1639                 if (retval)
1640                         return retval;
1641         }
1642
1643         /*
1644          * Figure out how many inode tables we need to move
1645          */
1646         to_move = moved = 0;
1647         for (i=0; i < max_groups; i++)
1648                 if (ext2fs_inode_table_loc(rfs->old_fs, i) !=
1649                     ext2fs_inode_table_loc(fs, i))
1650                         to_move++;
1651
1652         if (to_move == 0)
1653                 return 0;
1654
1655         if (rfs->progress) {
1656                 retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
1657                                        0, to_move);
1658                 if (retval)
1659                         goto errout;
1660         }
1661
1662         rfs->old_fs->flags |= EXT2_FLAG_MASTER_SB_ONLY;
1663
1664         for (i=0; i < max_groups; i++) {
1665                 old_blk = ext2fs_inode_table_loc(rfs->old_fs, i);
1666                 new_blk = ext2fs_inode_table_loc(fs, i);
1667                 diff = new_blk - old_blk;
1668
1669 #ifdef RESIZE2FS_DEBUG
1670                 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1671                         printf("Itable move group %d block %llu->%llu (diff %lld)\n",
1672                                i, old_blk, new_blk, diff);
1673 #endif
1674
1675                 if (!diff)
1676                         continue;
1677
1678                 retval = io_channel_read_blk64(fs->io, old_blk,
1679                                                fs->inode_blocks_per_group,
1680                                                rfs->itable_buf);
1681                 if (retval)
1682                         goto errout;
1683                 /*
1684                  * The end of the inode table segment often contains
1685                  * all zeros, and we're often only moving the inode
1686                  * table down a block or two.  If so, we can optimize
1687                  * things by not rewriting blocks that we know to be zero
1688                  * already.
1689                  */
1690                 for (cp = rfs->itable_buf+size-1, n=0; n < size; n++, cp--)
1691                         if (*cp)
1692                                 break;
1693                 n = n >> EXT2_BLOCK_SIZE_BITS(fs->super);
1694 #ifdef RESIZE2FS_DEBUG
1695                 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1696                         printf("%d blocks of zeros...\n", n);
1697 #endif
1698                 num = fs->inode_blocks_per_group;
1699                 if (n > diff)
1700                         num -= n;
1701
1702                 retval = io_channel_write_blk64(fs->io, new_blk,
1703                                                 num, rfs->itable_buf);
1704                 if (retval) {
1705                         io_channel_write_blk64(fs->io, old_blk,
1706                                                num, rfs->itable_buf);
1707                         goto errout;
1708                 }
1709                 if (n > diff) {
1710                         retval = io_channel_write_blk64(fs->io,
1711                               old_blk + fs->inode_blocks_per_group,
1712                               diff, (rfs->itable_buf +
1713                                      (fs->inode_blocks_per_group - diff) *
1714                                      fs->blocksize));
1715                         if (retval)
1716                                 goto errout;
1717                 }
1718
1719                 for (blk = ext2fs_inode_table_loc(rfs->old_fs, i), j=0;
1720                      j < fs->inode_blocks_per_group ; j++, blk++)
1721                         ext2fs_block_alloc_stats2(fs, blk, -1);
1722
1723                 ext2fs_inode_table_loc_set(rfs->old_fs, i, new_blk);
1724                 ext2fs_group_desc_csum_set(rfs->old_fs, i);
1725                 ext2fs_mark_super_dirty(rfs->old_fs);
1726                 ext2fs_flush(rfs->old_fs);
1727
1728                 if (rfs->progress) {
1729                         retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
1730                                                ++moved, to_move);
1731                         if (retval)
1732                                 goto errout;
1733                 }
1734         }
1735         mark_table_blocks(fs, fs->block_map);
1736         ext2fs_flush(fs);
1737 #ifdef RESIZE2FS_DEBUG
1738         if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1739                 printf("Inode table move finished.\n");
1740 #endif
1741         return 0;
1742
1743 errout:
1744         return retval;
1745 }
1746
1747 /*
1748  * Fix the resize inode
1749  */
1750 static errcode_t fix_resize_inode(ext2_filsys fs)
1751 {
1752         struct ext2_inode       inode;
1753         errcode_t               retval;
1754         char                    *block_buf = NULL;
1755
1756         if (!(fs->super->s_feature_compat &
1757               EXT2_FEATURE_COMPAT_RESIZE_INODE))
1758                 return 0;
1759
1760         retval = ext2fs_get_mem(fs->blocksize, &block_buf);
1761         if (retval) goto errout;
1762
1763         retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode);
1764         if (retval) goto errout;
1765
1766         ext2fs_iblk_set(fs, &inode, 1);
1767
1768         retval = ext2fs_write_inode(fs, EXT2_RESIZE_INO, &inode);
1769         if (retval) goto errout;
1770
1771         if (!inode.i_block[EXT2_DIND_BLOCK]) {
1772                 /*
1773                  * Avoid zeroing out block #0; that's rude.  This
1774                  * should never happen anyway since the filesystem
1775                  * should be fsck'ed and we assume it is consistent.
1776                  */
1777                 fprintf(stderr,
1778                         _("Should never happen: resize inode corrupt!\n"));
1779                 exit(1);
1780         }
1781
1782         memset(block_buf, 0, fs->blocksize);
1783
1784         retval = io_channel_write_blk64(fs->io, inode.i_block[EXT2_DIND_BLOCK],
1785                                         1, block_buf);
1786         if (retval) goto errout;
1787
1788         retval = ext2fs_create_resize_inode(fs);
1789         if (retval)
1790                 goto errout;
1791
1792 errout:
1793         if (block_buf)
1794                 ext2fs_free_mem(&block_buf);
1795         return retval;
1796 }
1797
1798 /*
1799  * Finally, recalculate the summary information
1800  */
1801 static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs)
1802 {
1803         blk64_t         blk;
1804         ext2_ino_t      ino;
1805         unsigned int    group = 0;
1806         unsigned int    count = 0;
1807         blk64_t         total_blocks_free = 0;
1808         int             total_inodes_free = 0;
1809         int             group_free = 0;
1810         int             uninit = 0;
1811         blk64_t         super_blk, old_desc_blk, new_desc_blk;
1812         int             old_desc_blocks;
1813
1814         /*
1815          * First calculate the block statistics
1816          */
1817         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT);
1818         ext2fs_super_and_bgd_loc2(fs, group, &super_blk, &old_desc_blk,
1819                                   &new_desc_blk, 0);
1820         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
1821                 old_desc_blocks = fs->super->s_first_meta_bg;
1822         else
1823                 old_desc_blocks = fs->desc_blocks +
1824                         fs->super->s_reserved_gdt_blocks;
1825         for (blk = fs->super->s_first_data_block;
1826              blk < ext2fs_blocks_count(fs->super); blk++) {
1827                 if ((uninit &&
1828                      !((blk == super_blk) ||
1829                        ((old_desc_blk && old_desc_blocks &&
1830                          (blk >= old_desc_blk) &&
1831                          (blk < old_desc_blk + old_desc_blocks))) ||
1832                        ((new_desc_blk && (blk == new_desc_blk))) ||
1833                        (blk == ext2fs_block_bitmap_loc(fs, group)) ||
1834                        (blk == ext2fs_inode_bitmap_loc(fs, group)) ||
1835                        ((blk >= ext2fs_inode_table_loc(fs, group) &&
1836                          (blk < ext2fs_inode_table_loc(fs, group)
1837                           + fs->inode_blocks_per_group))))) ||
1838                     (!ext2fs_fast_test_block_bitmap2(fs->block_map, blk))) {
1839                         group_free++;
1840                         total_blocks_free++;
1841                 }
1842                 count++;
1843                 if ((count == fs->super->s_blocks_per_group) ||
1844                     (blk == ext2fs_blocks_count(fs->super)-1)) {
1845                         ext2fs_bg_free_blocks_count_set(fs, group, group_free);
1846                         ext2fs_group_desc_csum_set(fs, group);
1847                         group++;
1848                         if (group >= fs->group_desc_count)
1849                                 break;
1850                         count = 0;
1851                         group_free = 0;
1852                         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT);
1853                         ext2fs_super_and_bgd_loc2(fs, group, &super_blk,
1854                                                   &old_desc_blk,
1855                                                   &new_desc_blk, 0);
1856                         if (fs->super->s_feature_incompat &
1857                             EXT2_FEATURE_INCOMPAT_META_BG)
1858                                 old_desc_blocks = fs->super->s_first_meta_bg;
1859                         else
1860                                 old_desc_blocks = fs->desc_blocks +
1861                                         fs->super->s_reserved_gdt_blocks;
1862                 }
1863         }
1864         ext2fs_free_blocks_count_set(fs->super, total_blocks_free);
1865
1866         /*
1867          * Next, calculate the inode statistics
1868          */
1869         group_free = 0;
1870         count = 0;
1871         group = 0;
1872
1873         /* Protect loop from wrap-around if s_inodes_count maxed */
1874         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT);
1875         for (ino = 1; ino <= fs->super->s_inodes_count && ino > 0; ino++) {
1876                 if (uninit ||
1877                     !ext2fs_fast_test_inode_bitmap2(fs->inode_map, ino)) {
1878                         group_free++;
1879                         total_inodes_free++;
1880                 }
1881                 count++;
1882                 if ((count == fs->super->s_inodes_per_group) ||
1883                     (ino == fs->super->s_inodes_count)) {
1884                         ext2fs_bg_free_inodes_count_set(fs, group, group_free);
1885                         ext2fs_group_desc_csum_set(fs, group);
1886                         group++;
1887                         if (group >= fs->group_desc_count)
1888                                 break;
1889                         count = 0;
1890                         group_free = 0;
1891                         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT);
1892                 }
1893         }
1894         fs->super->s_free_inodes_count = total_inodes_free;
1895         ext2fs_mark_super_dirty(fs);
1896         return 0;
1897 }
1898
1899 /*
1900  *  Journal may have been relocated; update the backup journal blocks
1901  *  in the superblock.
1902  */
1903 static errcode_t fix_sb_journal_backup(ext2_filsys fs)
1904 {
1905         errcode_t         retval;
1906         struct ext2_inode inode;
1907
1908         if (!(fs->super->s_feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1909                 return 0;
1910
1911         /* External journal? Nothing to do. */
1912         if (fs->super->s_journal_dev && !fs->super->s_journal_inum)
1913                 return 0;
1914
1915         retval = ext2fs_read_inode(fs, fs->super->s_journal_inum, &inode);
1916         if (retval)
1917                 return retval;
1918         memcpy(fs->super->s_jnl_blocks, inode.i_block, EXT2_N_BLOCKS*4);
1919         fs->super->s_jnl_blocks[15] = inode.i_size_high;
1920         fs->super->s_jnl_blocks[16] = inode.i_size;
1921         fs->super->s_jnl_backup_type = EXT3_JNL_BACKUP_BLOCKS;
1922         ext2fs_mark_super_dirty(fs);
1923         return 0;
1924 }
1925
1926 static int calc_group_overhead(ext2_filsys fs, blk64_t grp,
1927                                int old_desc_blocks)
1928 {
1929         blk64_t super_blk, old_desc_blk, new_desc_blk;
1930         int overhead;
1931
1932         /* inode table blocks plus allocation bitmaps */
1933         overhead = fs->inode_blocks_per_group + 2;
1934
1935         ext2fs_super_and_bgd_loc2(fs, grp, &super_blk,
1936                                   &old_desc_blk, &new_desc_blk, 0);
1937         if ((grp == 0) || super_blk)
1938                 overhead++;
1939         if (old_desc_blk)
1940                 overhead += old_desc_blocks;
1941         else if (new_desc_blk)
1942                 overhead++;
1943         return overhead;
1944 }
1945
1946
1947 /*
1948  * calcluate the minimum number of blocks the given fs can be resized to
1949  */
1950 blk64_t calculate_minimum_resize_size(ext2_filsys fs)
1951 {
1952         ext2_ino_t inode_count;
1953         blk64_t blks_needed, groups, data_blocks;
1954         blk64_t grp, data_needed, last_start;
1955         blk64_t overhead = 0;
1956         int old_desc_blocks;
1957         int extra_groups = 0;
1958         int flexbg_size = 1 << fs->super->s_log_groups_per_flex;
1959
1960         /*
1961          * first figure out how many group descriptors we need to
1962          * handle the number of inodes we have
1963          */
1964         inode_count = fs->super->s_inodes_count -
1965                 fs->super->s_free_inodes_count;
1966         blks_needed = ext2fs_div_ceil(inode_count,
1967                                       fs->super->s_inodes_per_group) *
1968                 EXT2_BLOCKS_PER_GROUP(fs->super);
1969         groups = ext2fs_div64_ceil(blks_needed,
1970                                    EXT2_BLOCKS_PER_GROUP(fs->super));
1971
1972         /*
1973          * number of old-style block group descriptor blocks
1974          */
1975         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
1976                 old_desc_blocks = fs->super->s_first_meta_bg;
1977         else
1978                 old_desc_blocks = fs->desc_blocks +
1979                         fs->super->s_reserved_gdt_blocks;
1980
1981         /* calculate how many blocks are needed for data */
1982         data_needed = ext2fs_blocks_count(fs->super) -
1983                 ext2fs_free_blocks_count(fs->super);
1984
1985         for (grp = 0; grp < fs->group_desc_count; grp++)
1986                 data_needed -= calc_group_overhead(fs, grp, old_desc_blocks);
1987
1988         /*
1989          * For ext4 we need to allow for up to a flex_bg worth of
1990          * inode tables of slack space so the resize operation can be
1991          * guaranteed to finish.
1992          */
1993         if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_FLEX_BG) {
1994                 extra_groups = flexbg_size - (groups & (flexbg_size - 1));
1995                 data_needed += fs->inode_blocks_per_group * extra_groups;
1996                 extra_groups = groups % flexbg_size;
1997         }
1998
1999         /*
2000          * figure out how many data blocks we have given the number of groups
2001          * we need for our inodes
2002          */
2003         data_blocks = groups * EXT2_BLOCKS_PER_GROUP(fs->super);
2004         last_start = 0;
2005         for (grp = 0; grp < groups; grp++) {
2006                 overhead = calc_group_overhead(fs, grp, old_desc_blocks);
2007
2008                 /*
2009                  * we want to keep track of how much data we can store in
2010                  * the groups leading up to the last group so we can determine
2011                  * how big the last group needs to be
2012                  */
2013                 if (grp != (groups - 1))
2014                         last_start += EXT2_BLOCKS_PER_GROUP(fs->super) -
2015                                 overhead;
2016
2017                 data_blocks -= overhead;
2018         }
2019
2020         /*
2021          * if we need more group descriptors in order to accomodate our data
2022          * then we need to add them here
2023          */
2024         while (data_needed > data_blocks) {
2025                 blk64_t remainder = data_needed - data_blocks;
2026                 blk64_t extra_grps;
2027
2028                 /* figure out how many more groups we need for the data */
2029                 extra_grps = ext2fs_div64_ceil(remainder,
2030                                                EXT2_BLOCKS_PER_GROUP(fs->super));
2031
2032                 data_blocks += extra_grps * EXT2_BLOCKS_PER_GROUP(fs->super);
2033
2034                 /* ok we have to account for the last group */
2035                 overhead = calc_group_overhead(fs, groups-1, old_desc_blocks);
2036                 last_start += EXT2_BLOCKS_PER_GROUP(fs->super) - overhead;
2037
2038                 for (grp = groups; grp < groups+extra_grps; grp++) {
2039                         overhead = calc_group_overhead(fs, grp,
2040                                                        old_desc_blocks);
2041
2042                         /*
2043                          * again, we need to see how much data we cram into
2044                          * all of the groups leading up to the last group
2045                          */
2046                         if (grp != (groups + extra_grps - 1))
2047                                 last_start += EXT2_BLOCKS_PER_GROUP(fs->super)
2048                                         - overhead;
2049
2050                         data_blocks -= overhead;
2051                 }
2052
2053                 groups += extra_grps;
2054                 extra_groups += extra_grps;
2055                 if (fs->super->s_feature_incompat
2056                         & EXT4_FEATURE_INCOMPAT_FLEX_BG
2057                     && extra_groups > flexbg_size) {
2058                         /*
2059                          * For ext4 we need to allow for up to a flex_bg worth
2060                          * of inode tables of slack space so the resize
2061                          * operation can be guaranteed to finish.
2062                          */
2063                         extra_groups = flexbg_size -
2064                                                 (groups & (flexbg_size - 1));
2065                         data_needed += (fs->inode_blocks_per_group *
2066                                         extra_groups);
2067                         extra_groups = groups % flexbg_size;
2068                 }
2069         }
2070
2071         /* now for the fun voodoo */
2072         overhead = calc_group_overhead(fs, groups-1, old_desc_blocks);
2073
2074         /*
2075          * if this is the case then the last group is going to have data in it
2076          * so we need to adjust the size of the last group accordingly
2077          */
2078         if (last_start < data_needed) {
2079                 blk64_t remainder = data_needed - last_start;
2080
2081                 /*
2082                  * 50 is a magic number that mkfs/resize uses to see if its
2083                  * even worth making/resizing the fs.  basically you need to
2084                  * have at least 50 blocks in addition to the blocks needed
2085                  * for the metadata in the last group
2086                  */
2087                 if (remainder > 50)
2088                         overhead += remainder;
2089                 else
2090                         overhead += 50;
2091         } else
2092                 overhead += 50;
2093
2094         overhead += fs->super->s_first_data_block;
2095
2096         /*
2097          * since our last group doesn't have to be BLOCKS_PER_GROUP large, we
2098          * only do groups-1, and then add the number of blocks needed to
2099          * handle the group descriptor metadata+data that we need
2100          */
2101         blks_needed = (groups-1) * EXT2_BLOCKS_PER_GROUP(fs->super);
2102         blks_needed += overhead;
2103
2104         /*
2105          * If at this point we've already added up more "needed" than
2106          * the current size, just return current size as minimum.
2107          */
2108         if (blks_needed >= ext2fs_blocks_count(fs->super))
2109                 return ext2fs_blocks_count(fs->super);
2110         /*
2111          * We need to reserve a few extra blocks if extents are
2112          * enabled, in case we need to grow the extent tree.  The more
2113          * we shrink the file system, the more space we need.
2114          */
2115         if (fs->super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_EXTENTS)
2116                 blks_needed += (ext2fs_blocks_count(fs->super) -
2117                                 blks_needed)/500;
2118
2119         return blks_needed;
2120 }