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 static errcode_t mark_table_blocks(ext2_filsys fs,
  55                                    ext2fs_block_bitmap bmap);
  56 static errcode_t clear_sparse_super2_last_group(ext2_resize_t rfs);
  57 static errcode_t reserve_sparse_super2_last_group(ext2_resize_t rfs,
  58                                                  ext2fs_block_bitmap meta_bmap);
  59
  60 /*
  61  * Some helper CPP macros
  62  */
  63 #define IS_BLOCK_BM(fs, i, blk) ((blk) == ext2fs_block_bitmap_loc((fs),(i)))
  64 #define IS_INODE_BM(fs, i, blk) ((blk) == ext2fs_inode_bitmap_loc((fs),(i)))
  65
  66 #define IS_INODE_TB(fs, i, blk) (((blk) >= ext2fs_inode_table_loc((fs), (i))) && \
  67                                  ((blk) < (ext2fs_inode_table_loc((fs), (i)) + \
  68                                            (fs)->inode_blocks_per_group)))
  69
  70 /* Some bigalloc helper macros which are more succint... */
  71 #define B2C(x)  EXT2FS_B2C(fs, (x))
  72 #define C2B(x)  EXT2FS_C2B(fs, (x))
  73 #define EQ_CLSTR(x, y) (B2C(x) == B2C(y))
  74 #define LE_CLSTR(x, y) (B2C(x) <= B2C(y))
  75 #define LT_CLSTR(x, y) (B2C(x) <  B2C(y))
  76 #define GE_CLSTR(x, y) (B2C(x) >= B2C(y))
  77 #define GT_CLSTR(x, y) (B2C(x) >  B2C(y))
  78
  79 static int lazy_itable_init;
  80
  81 /*
  82  * This is the top-level routine which does the dirty deed....
  83  */
  84 errcode_t resize_fs(ext2_filsys fs, blk64_t *new_size, int flags,
  85             errcode_t (*progress)(ext2_resize_t rfs, int pass,
  86                                           unsigned long cur,
  87                                           unsigned long max_val))
  88 {
  89         ext2_resize_t   rfs;
  90         errcode_t       retval;
  91         struct resource_track   rtrack, overall_track;
  92
  93         /*
  94          * Create the data structure
  95          */
  96         retval = ext2fs_get_mem(sizeof(struct ext2_resize_struct), &rfs);
  97         if (retval)
  98                 return retval;
  99
 100         memset(rfs, 0, sizeof(struct ext2_resize_struct));
 101         fs->priv_data = rfs;
 102         rfs->old_fs = fs;
 103         rfs->flags = flags;
 104         rfs->itable_buf  = 0;
 105         rfs->progress = progress;
 106
 107         init_resource_track(&overall_track, "overall resize2fs", fs->io);
 108         init_resource_track(&rtrack, "read_bitmaps", fs->io);
 109         retval = ext2fs_read_bitmaps(fs);
 110         if (retval)
 111                 goto errout;
 112         print_resource_track(rfs, &rtrack, fs->io);
 113
 114         fs->super->s_state |= EXT2_ERROR_FS;
 115         ext2fs_mark_super_dirty(fs);
 116         ext2fs_flush(fs);
 117
 118         init_resource_track(&rtrack, "fix_uninit_block_bitmaps 1", fs->io);
 119         fix_uninit_block_bitmaps(fs);
 120         print_resource_track(rfs, &rtrack, fs->io);
 121         retval = ext2fs_dup_handle(fs, &rfs->new_fs);
 122         if (retval)
 123                 goto errout;
 124
 125         init_resource_track(&rtrack, "adjust_superblock", fs->io);
 126         retval = adjust_superblock(rfs, *new_size);
 127         if (retval)
 128                 goto errout;
 129         print_resource_track(rfs, &rtrack, fs->io);
 130
 131
 132         init_resource_track(&rtrack, "fix_uninit_block_bitmaps 2", fs->io);
 133         fix_uninit_block_bitmaps(rfs->new_fs);
 134         print_resource_track(rfs, &rtrack, fs->io);
 135         /* Clear the block bitmap uninit flag for the last block group */
 136         ext2fs_bg_flags_clear(rfs->new_fs, rfs->new_fs->group_desc_count - 1,
 137                              EXT2_BG_BLOCK_UNINIT);
 138
 139         *new_size = ext2fs_blocks_count(rfs->new_fs->super);
 140
 141         init_resource_track(&rtrack, "blocks_to_move", fs->io);
 142         retval = blocks_to_move(rfs);
 143         if (retval)
 144                 goto errout;
 145         print_resource_track(rfs, &rtrack, fs->io);
 146
 147 #ifdef RESIZE2FS_DEBUG
 148         if (rfs->flags & RESIZE_DEBUG_BMOVE)
 149                 printf("Number of free blocks: %llu/%llu, Needed: %llu\n",
 150                        ext2fs_free_blocks_count(rfs->old_fs->super),
 151                        ext2fs_free_blocks_count(rfs->new_fs->super),
 152                        rfs->needed_blocks);
 153 #endif
 154
 155         init_resource_track(&rtrack, "block_mover", fs->io);
 156         retval = block_mover(rfs);
 157         if (retval)
 158                 goto errout;
 159         print_resource_track(rfs, &rtrack, fs->io);
 160
 161         init_resource_track(&rtrack, "inode_scan_and_fix", fs->io);
 162         retval = inode_scan_and_fix(rfs);
 163         if (retval)
 164                 goto errout;
 165         print_resource_track(rfs, &rtrack, fs->io);
 166
 167         init_resource_track(&rtrack, "inode_ref_fix", fs->io);
 168         retval = inode_ref_fix(rfs);
 169         if (retval)
 170                 goto errout;
 171         print_resource_track(rfs, &rtrack, fs->io);
 172
 173         init_resource_track(&rtrack, "move_itables", fs->io);
 174         retval = move_itables(rfs);
 175         if (retval)
 176                 goto errout;
 177         print_resource_track(rfs, &rtrack, fs->io);
 178
 179         init_resource_track(&rtrack, "calculate_summary_stats", fs->io);
 180         retval = ext2fs_calculate_summary_stats(rfs->new_fs);
 181         if (retval)
 182                 goto errout;
 183         print_resource_track(rfs, &rtrack, fs->io);
 184
 185         init_resource_track(&rtrack, "fix_resize_inode", fs->io);
 186         retval = fix_resize_inode(rfs->new_fs);
 187         if (retval)
 188                 goto errout;
 189         print_resource_track(rfs, &rtrack, fs->io);
 190
 191         init_resource_track(&rtrack, "fix_sb_journal_backup", fs->io);
 192         retval = fix_sb_journal_backup(rfs->new_fs);
 193         if (retval)
 194                 goto errout;
 195         print_resource_track(rfs, &rtrack, fs->io);
 196
 197         retval = clear_sparse_super2_last_group(rfs);
 198         if (retval)
 199                 goto errout;
 200
 201         rfs->new_fs->super->s_state &= ~EXT2_ERROR_FS;
 202         rfs->new_fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
 203
 204         print_resource_track(rfs, &overall_track, fs->io);
 205         retval = ext2fs_close(rfs->new_fs);
 206         if (retval)
 207                 goto errout;
 208
 209         rfs->flags = flags;
 210
 211         ext2fs_free(rfs->old_fs);
 212         rfs->old_fs = NULL;
 213         if (rfs->itable_buf)
 214                 ext2fs_free_mem(&rfs->itable_buf);
 215         if (rfs->reserve_blocks)
 216                 ext2fs_free_block_bitmap(rfs->reserve_blocks);
 217         if (rfs->move_blocks)
 218                 ext2fs_free_block_bitmap(rfs->move_blocks);
 219         ext2fs_free_mem(&rfs);
 220
 221         return 0;
 222
 223 errout:
 224         if (rfs->new_fs) {
 225                 ext2fs_free(rfs->new_fs);
 226                 rfs->new_fs = NULL;
 227         }
 228         if (rfs->itable_buf)
 229                 ext2fs_free_mem(&rfs->itable_buf);
 230         ext2fs_free_mem(&rfs);
 231         return retval;
 232 }
 233
 234 /*
 235  * Clean up the bitmaps for unitialized bitmaps
 236  */
 237 static void fix_uninit_block_bitmaps(ext2_filsys fs)
 238 {
 239         blk64_t         blk, lblk;
 240         dgrp_t          g;
 241         int             i;
 242
 243         if (!ext2fs_has_group_desc_csum(fs))
 244                 return;
 245
 246         for (g=0; g < fs->group_desc_count; g++) {
 247                 if (!(ext2fs_bg_flags_test(fs, g, EXT2_BG_BLOCK_UNINIT)))
 248                         continue;
 249
 250                 blk = ext2fs_group_first_block2(fs, g);
 251                 lblk = ext2fs_group_last_block2(fs, g);
 252                 ext2fs_unmark_block_bitmap_range2(fs->block_map, blk,
 253                                                   lblk - blk + 1);
 254
 255                 ext2fs_reserve_super_and_bgd(fs, g, fs->block_map);
 256                 ext2fs_mark_block_bitmap2(fs->block_map,
 257                                           ext2fs_block_bitmap_loc(fs, g));
 258                 ext2fs_mark_block_bitmap2(fs->block_map,
 259                                           ext2fs_inode_bitmap_loc(fs, g));
 260                 for (i = 0, blk = ext2fs_inode_table_loc(fs, g);
 261                      i < (unsigned int) fs->inode_blocks_per_group;
 262                      i++, blk++)
 263                         ext2fs_mark_block_bitmap2(fs->block_map, blk);
 264         }
 265 }
 266
 267 /* --------------------------------------------------------------------
 268  *
 269  * Resize processing, phase 1.
 270  *
 271  * In this phase we adjust the in-memory superblock information, and
 272  * initialize any new parts of the inode table.  The new parts of the
 273  * inode table are created in virgin disk space, so we can abort here
 274  * without any side effects.
 275  * --------------------------------------------------------------------
 276  */
 277
 278 /*
 279  * If the group descriptor's bitmap and inode table blocks are valid,
 280  * release them in the new filesystem data structure, and mark them as
 281  * reserved so the old inode table blocks don't get overwritten.
 282  */
 283 static errcode_t free_gdp_blocks(ext2_filsys fs,
 284                                  ext2fs_block_bitmap reserve_blocks,
 285                                  ext2_filsys old_fs,
 286                                  dgrp_t group)
 287 {
 288         blk64_t blk;
 289         int     j;
 290         dgrp_t  i;
 291         ext2fs_block_bitmap bg_map = NULL;
 292         errcode_t retval = 0;
 293         dgrp_t count = old_fs->group_desc_count - fs->group_desc_count;
 294
 295         /* If bigalloc, don't free metadata living in the same cluster */
 296         if (EXT2FS_CLUSTER_RATIO(fs) > 1) {
 297                 retval = ext2fs_allocate_block_bitmap(fs, "bgdata", &bg_map);
 298                 if (retval)
 299                         goto out;
 300
 301                 retval = mark_table_blocks(fs, bg_map);
 302                 if (retval)
 303                         goto out;
 304         }
 305
 306         for (i = group; i < group + count; i++) {
 307                 blk = ext2fs_block_bitmap_loc(old_fs, i);
 308                 if (blk &&
 309                     (blk < ext2fs_blocks_count(fs->super)) &&
 310                     !(bg_map && ext2fs_test_block_bitmap2(bg_map, blk))) {
 311                         ext2fs_block_alloc_stats2(fs, blk, -1);
 312                         ext2fs_mark_block_bitmap2(reserve_blocks, blk);
 313                 }
 314
 315                 blk = ext2fs_inode_bitmap_loc(old_fs, i);
 316                 if (blk &&
 317                     (blk < ext2fs_blocks_count(fs->super)) &&
 318                     !(bg_map && ext2fs_test_block_bitmap2(bg_map, blk))) {
 319                         ext2fs_block_alloc_stats2(fs, blk, -1);
 320                         ext2fs_mark_block_bitmap2(reserve_blocks, blk);
 321                 }
 322
 323                 blk = ext2fs_inode_table_loc(old_fs, i);
 324                 for (j = 0;
 325                      j < fs->inode_blocks_per_group; j++, blk++) {
 326                         if (blk >= ext2fs_blocks_count(fs->super) ||
 327                             (bg_map && ext2fs_test_block_bitmap2(bg_map, blk)))
 328                                 continue;
 329                         ext2fs_block_alloc_stats2(fs, blk, -1);
 330                         ext2fs_mark_block_bitmap2(reserve_blocks, blk);
 331                 }
 332         }
 333
 334 out:
 335         if (bg_map)
 336                 ext2fs_free_block_bitmap(bg_map);
 337         return retval;
 338 }
 339
 340 /*
 341  * This routine is shared by the online and offline resize routines.
 342  * All of the information which is adjusted in memory is done here.
 343  */
 344 errcode_t adjust_fs_info(ext2_filsys fs, ext2_filsys old_fs,
 345                          ext2fs_block_bitmap reserve_blocks, blk64_t new_size)
 346 {
 347         errcode_t       retval;
 348         blk64_t         overhead = 0;
 349         blk64_t         rem;
 350         blk64_t         blk, group_block;
 351         blk64_t         real_end;
 352         blk64_t         old_numblocks, numblocks, adjblocks;
 353         unsigned long   i, j, old_desc_blocks;
 354         unsigned int    meta_bg, meta_bg_size;
 355         int             has_super, csum_flag;
 356         unsigned long long new_inodes;  /* u64 to check for overflow */
 357         double          percent;
 358
 359         ext2fs_blocks_count_set(fs->super, new_size);
 360
 361 retry:
 362         fs->group_desc_count = ext2fs_div64_ceil(ext2fs_blocks_count(fs->super) -
 363                                        fs->super->s_first_data_block,
 364                                        EXT2_BLOCKS_PER_GROUP(fs->super));
 365         if (fs->group_desc_count == 0)
 366                 return EXT2_ET_TOOSMALL;
 367         fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count,
 368                                           EXT2_DESC_PER_BLOCK(fs->super));
 369
 370         /*
 371          * Overhead is the number of bookkeeping blocks per group.  It
 372          * includes the superblock backup, the group descriptor
 373          * backups, the inode bitmap, the block bitmap, and the inode
 374          * table.
 375          */
 376         overhead = (int) (2 + fs->inode_blocks_per_group);
 377
 378         if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1))
 379                 overhead += 1 + fs->desc_blocks +
 380                         fs->super->s_reserved_gdt_blocks;
 381
 382         /*
 383          * See if the last group is big enough to support the
 384          * necessary data structures.  If not, we need to get rid of
 385          * it.
 386          */
 387         rem = (ext2fs_blocks_count(fs->super) - fs->super->s_first_data_block) %
 388                 fs->super->s_blocks_per_group;
 389         if ((fs->group_desc_count == 1) && rem && (rem < overhead))
 390                 return EXT2_ET_TOOSMALL;
 391         if ((fs->group_desc_count > 1) && rem && (rem < overhead+50)) {
 392                 ext2fs_blocks_count_set(fs->super,
 393                                         ext2fs_blocks_count(fs->super) - rem);
 394                 goto retry;
 395         }
 396         /*
 397          * Adjust the number of inodes
 398          */
 399         new_inodes =(unsigned long long) fs->super->s_inodes_per_group * fs->group_desc_count;
 400         if (new_inodes > ~0U) {
 401                 fprintf(stderr, _("inodes (%llu) must be less than %u"),
 402                                    new_inodes, ~0U);
 403                 return EXT2_ET_TOO_MANY_INODES;
 404         }
 405         fs->super->s_inodes_count = fs->super->s_inodes_per_group *
 406                 fs->group_desc_count;
 407
 408         /*
 409          * Adjust the number of free blocks
 410          */
 411         blk = ext2fs_blocks_count(old_fs->super);
 412         if (blk > ext2fs_blocks_count(fs->super))
 413                 ext2fs_free_blocks_count_set(fs->super,
 414                         ext2fs_free_blocks_count(fs->super) -
 415                         (blk - ext2fs_blocks_count(fs->super)));
 416         else
 417                 ext2fs_free_blocks_count_set(fs->super,
 418                         ext2fs_free_blocks_count(fs->super) +
 419                         (ext2fs_blocks_count(fs->super) - blk));
 420
 421         /*
 422          * Adjust the number of reserved blocks
 423          */
 424         percent = (ext2fs_r_blocks_count(old_fs->super) * 100.0) /
 425                 ext2fs_blocks_count(old_fs->super);
 426         ext2fs_r_blocks_count_set(fs->super,
 427                                   (percent * ext2fs_blocks_count(fs->super) /
 428                                    100.0));
 429
 430         /*
 431          * Adjust the bitmaps for size
 432          */
 433         retval = ext2fs_resize_inode_bitmap2(fs->super->s_inodes_count,
 434                                             fs->super->s_inodes_count,
 435                                             fs->inode_map);
 436         if (retval) goto errout;
 437
 438         real_end = (((blk64_t) EXT2_BLOCKS_PER_GROUP(fs->super) *
 439                      fs->group_desc_count)) - 1 +
 440                 fs->super->s_first_data_block;
 441         retval = ext2fs_resize_block_bitmap2(new_size - 1,
 442                                              real_end, fs->block_map);
 443         if (retval) goto errout;
 444
 445         /*
 446          * If we are growing the file system, also grow the size of
 447          * the reserve_blocks bitmap
 448          */
 449         if (reserve_blocks && new_size > ext2fs_blocks_count(old_fs->super)) {
 450                 retval = ext2fs_resize_block_bitmap2(new_size - 1,
 451                                                      real_end, reserve_blocks);
 452                 if (retval) goto errout;
 453         }
 454
 455         /*
 456          * Reallocate the group descriptors as necessary.
 457          */
 458         if (old_fs->desc_blocks != fs->desc_blocks) {
 459                 retval = ext2fs_resize_mem(old_fs->desc_blocks *
 460                                            fs->blocksize,
 461                                            fs->desc_blocks * fs->blocksize,
 462                                            &fs->group_desc);
 463                 if (retval)
 464                         goto errout;
 465                 if (fs->desc_blocks > old_fs->desc_blocks)
 466                         memset((char *) fs->group_desc +
 467                                (old_fs->desc_blocks * fs->blocksize), 0,
 468                                (fs->desc_blocks - old_fs->desc_blocks) *
 469                                fs->blocksize);
 470         }
 471
 472         /*
 473          * If the resize_inode feature is set, and we are changing the
 474          * number of descriptor blocks, then adjust
 475          * s_reserved_gdt_blocks if possible to avoid needing to move
 476          * the inode table either now or in the future.
 477          */
 478         if ((fs->super->s_feature_compat &
 479              EXT2_FEATURE_COMPAT_RESIZE_INODE) &&
 480             (old_fs->desc_blocks != fs->desc_blocks)) {
 481                 int new;
 482
 483                 new = ((int) fs->super->s_reserved_gdt_blocks) +
 484                         (old_fs->desc_blocks - fs->desc_blocks);
 485                 if (new < 0)
 486                         new = 0;
 487                 if (new > (int) fs->blocksize/4)
 488                         new = fs->blocksize/4;
 489                 fs->super->s_reserved_gdt_blocks = new;
 490         }
 491
 492         /*
 493          * Update the location of the backup superblocks if the
 494          * sparse_super2 feature is enabled.
 495          */
 496         if (fs->super->s_feature_compat & EXT4_FEATURE_COMPAT_SPARSE_SUPER2) {
 497                 dgrp_t last_bg = fs->group_desc_count - 1;
 498                 dgrp_t old_last_bg = old_fs->group_desc_count - 1;
 499
 500                 if (last_bg > old_last_bg) {
 501                         if (old_fs->group_desc_count == 1)
 502                                 fs->super->s_backup_bgs[0] = 1;
 503                         if (old_fs->group_desc_count == 1 &&
 504                             fs->super->s_backup_bgs[0])
 505                                 fs->super->s_backup_bgs[0] = last_bg;
 506                         else if (fs->super->s_backup_bgs[1])
 507                                 fs->super->s_backup_bgs[1] = last_bg;
 508                 } else if (last_bg < old_last_bg) {
 509                         if (fs->super->s_backup_bgs[0] > last_bg)
 510                                 fs->super->s_backup_bgs[0] = 0;
 511                         if (fs->super->s_backup_bgs[1] > last_bg)
 512                                 fs->super->s_backup_bgs[1] = 0;
 513                         if (last_bg > 1 &&
 514                             old_fs->super->s_backup_bgs[1] == old_last_bg)
 515                                 fs->super->s_backup_bgs[1] = last_bg;
 516                 }
 517         }
 518
 519         /*
 520          * If we are shrinking the number of block groups, we're done
 521          * and can exit now.
 522          */
 523         if (old_fs->group_desc_count > fs->group_desc_count) {
 524                 /*
 525                  * Check the block groups that we are chopping off
 526                  * and free any blocks associated with their metadata
 527                  */
 528                 retval = free_gdp_blocks(fs, reserve_blocks, old_fs,
 529                                          fs->group_desc_count);
 530                 goto errout;
 531         }
 532
 533         /*
 534          * Fix the count of the last (old) block group
 535          */
 536         old_numblocks = (ext2fs_blocks_count(old_fs->super) -
 537                          old_fs->super->s_first_data_block) %
 538                                  old_fs->super->s_blocks_per_group;
 539         if (!old_numblocks)
 540                 old_numblocks = old_fs->super->s_blocks_per_group;
 541         if (old_fs->group_desc_count == fs->group_desc_count) {
 542                 numblocks = (ext2fs_blocks_count(fs->super) -
 543                              fs->super->s_first_data_block) %
 544                         fs->super->s_blocks_per_group;
 545                 if (!numblocks)
 546                         numblocks = fs->super->s_blocks_per_group;
 547         } else
 548                 numblocks = fs->super->s_blocks_per_group;
 549         i = old_fs->group_desc_count - 1;
 550         ext2fs_bg_free_blocks_count_set(fs, i, ext2fs_bg_free_blocks_count(fs, i) + (numblocks - old_numblocks));
 551         ext2fs_group_desc_csum_set(fs, i);
 552
 553         /*
 554          * If the number of block groups is staying the same, we're
 555          * done and can exit now.  (If the number block groups is
 556          * shrinking, we had exited earlier.)
 557          */
 558         if (old_fs->group_desc_count >= fs->group_desc_count) {
 559                 retval = 0;
 560                 goto errout;
 561         }
 562
 563         /*
 564          * Initialize the new block group descriptors
 565          */
 566         group_block = ext2fs_group_first_block2(fs,
 567                                                 old_fs->group_desc_count);
 568         csum_flag = ext2fs_has_group_desc_csum(fs);
 569         if (access("/sys/fs/ext4/features/lazy_itable_init", F_OK) == 0)
 570                 lazy_itable_init = 1;
 571         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
 572                 old_desc_blocks = fs->super->s_first_meta_bg;
 573         else
 574                 old_desc_blocks = fs->desc_blocks +
 575                         fs->super->s_reserved_gdt_blocks;
 576
 577         /*
 578          * If we changed the number of block_group descriptor blocks,
 579          * we need to make sure they are all marked as reserved in the
 580          * file systems's block allocation map.
 581          */
 582         for (i = 0; i < old_fs->group_desc_count; i++)
 583                 ext2fs_reserve_super_and_bgd(fs, i, fs->block_map);
 584
 585         for (i = old_fs->group_desc_count;
 586              i < fs->group_desc_count; i++) {
 587                 memset(ext2fs_group_desc(fs, fs->group_desc, i), 0,
 588                        sizeof(struct ext2_group_desc));
 589                 adjblocks = 0;
 590
 591                 ext2fs_bg_flags_zap(fs, i);
 592                 if (csum_flag) {
 593                         ext2fs_bg_flags_set(fs, i, EXT2_BG_INODE_UNINIT);
 594                         if (!lazy_itable_init)
 595                                 ext2fs_bg_flags_set(fs, i,
 596                                                     EXT2_BG_INODE_ZEROED);
 597                         ext2fs_bg_itable_unused_set(fs, i,
 598                                         fs->super->s_inodes_per_group);
 599                 }
 600
 601                 numblocks = ext2fs_group_blocks_count(fs, i);
 602                 if ((i < fs->group_desc_count - 1) && csum_flag)
 603                         ext2fs_bg_flags_set(fs, i, EXT2_BG_BLOCK_UNINIT);
 604
 605                 has_super = ext2fs_bg_has_super(fs, i);
 606                 if (has_super) {
 607                         ext2fs_block_alloc_stats2(fs, group_block, +1);
 608                         adjblocks++;
 609                 }
 610                 meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
 611                 meta_bg = i / meta_bg_size;
 612                 if (!(fs->super->s_feature_incompat &
 613                       EXT2_FEATURE_INCOMPAT_META_BG) ||
 614                     (meta_bg < fs->super->s_first_meta_bg)) {
 615                         if (has_super) {
 616                                 for (j=0; j < old_desc_blocks; j++)
 617                                         ext2fs_block_alloc_stats2(fs,
 618                                                  group_block + 1 + j, +1);
 619                                 adjblocks += old_desc_blocks;
 620                         }
 621                 } else {
 622                         if (has_super)
 623                                 has_super = 1;
 624                         if (((i % meta_bg_size) == 0) ||
 625                             ((i % meta_bg_size) == 1) ||
 626                             ((i % meta_bg_size) == (meta_bg_size-1)))
 627                                 ext2fs_block_alloc_stats2(fs,
 628                                                  group_block + has_super, +1);
 629                 }
 630
 631                 adjblocks += 2 + fs->inode_blocks_per_group;
 632
 633                 numblocks -= adjblocks;
 634                 ext2fs_free_blocks_count_set(fs->super,
 635                              ext2fs_free_blocks_count(fs->super) - adjblocks);
 636                 fs->super->s_free_inodes_count +=
 637                         fs->super->s_inodes_per_group;
 638                 ext2fs_bg_free_blocks_count_set(fs, i, numblocks);
 639                 ext2fs_bg_free_inodes_count_set(fs, i,
 640                                                 fs->super->s_inodes_per_group);
 641                 ext2fs_bg_used_dirs_count_set(fs, i, 0);
 642                 ext2fs_group_desc_csum_set(fs, i);
 643
 644                 retval = ext2fs_allocate_group_table(fs, i, 0);
 645                 if (retval) goto errout;
 646
 647                 group_block += fs->super->s_blocks_per_group;
 648         }
 649         retval = 0;
 650
 651         /*
 652          * Mark all of the metadata blocks as reserved so they won't
 653          * get allocated by the call to ext2fs_allocate_group_table()
 654          * in blocks_to_move(), where we allocate new blocks to
 655          * replace those allocation bitmap and inode table blocks
 656          * which have to get relocated to make space for an increased
 657          * number of the block group descriptors.
 658          */
 659         if (reserve_blocks)
 660                 mark_table_blocks(fs, reserve_blocks);
 661
 662 errout:
 663         return (retval);
 664 }
 665
 666 /*
 667  * This routine adjusts the superblock and other data structures, both
 668  * in disk as well as in memory...
 669  */
 670 static errcode_t adjust_superblock(ext2_resize_t rfs, blk64_t new_size)
 671 {
 672         ext2_filsys     fs = rfs->new_fs;
 673         int             adj = 0;
 674         errcode_t       retval;
 675         blk64_t         group_block;
 676         unsigned long   i;
 677         unsigned long   max_group;
 678
 679         ext2fs_mark_super_dirty(fs);
 680         ext2fs_mark_bb_dirty(fs);
 681         ext2fs_mark_ib_dirty(fs);
 682
 683         retval = ext2fs_allocate_block_bitmap(fs, _("reserved blocks"),
 684                                               &rfs->reserve_blocks);
 685         if (retval)
 686                 return retval;
 687
 688         retval = adjust_fs_info(fs, rfs->old_fs, rfs->reserve_blocks, new_size);
 689         if (retval)
 690                 goto errout;
 691
 692         /*
 693          * Check to make sure there are enough inodes
 694          */
 695         if ((rfs->old_fs->super->s_inodes_count -
 696              rfs->old_fs->super->s_free_inodes_count) >
 697             rfs->new_fs->super->s_inodes_count) {
 698                 retval = ENOSPC;
 699                 goto errout;
 700         }
 701
 702         /*
 703          * If we are shrinking the number block groups, we're done and
 704          * can exit now.
 705          */
 706         if (rfs->old_fs->group_desc_count > fs->group_desc_count) {
 707                 retval = 0;
 708                 goto errout;
 709         }
 710
 711         /*
 712          * If the number of block groups is staying the same, we're
 713          * done and can exit now.  (If the number block groups is
 714          * shrinking, we had exited earlier.)
 715          */
 716         if (rfs->old_fs->group_desc_count >= fs->group_desc_count) {
 717                 retval = 0;
 718                 goto errout;
 719         }
 720
 721         /*
 722          * If we are using uninit_bg (aka GDT_CSUM) and the kernel
 723          * supports lazy inode initialization, we can skip
 724          * initializing the inode table.
 725          */
 726         if (lazy_itable_init && ext2fs_has_group_desc_csum(fs)) {
 727                 retval = 0;
 728                 goto errout;
 729         }
 730
 731         /*
 732          * Initialize the inode table
 733          */
 734         retval = ext2fs_get_array(fs->blocksize, fs->inode_blocks_per_group,
 735                                 &rfs->itable_buf);
 736         if (retval)
 737                 goto errout;
 738
 739         memset(rfs->itable_buf, 0, fs->blocksize * fs->inode_blocks_per_group);
 740         group_block = ext2fs_group_first_block2(fs,
 741                                                 rfs->old_fs->group_desc_count);
 742         adj = rfs->old_fs->group_desc_count;
 743         max_group = fs->group_desc_count - adj;
 744         if (rfs->progress) {
 745                 retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
 746                                        0, max_group);
 747                 if (retval)
 748                         goto errout;
 749         }
 750         for (i = rfs->old_fs->group_desc_count;
 751              i < fs->group_desc_count; i++) {
 752                 /*
 753                  * Write out the new inode table
 754                  */
 755                 retval = io_channel_write_blk64(fs->io,
 756                                                 ext2fs_inode_table_loc(fs, i),
 757                                                 fs->inode_blocks_per_group,
 758                                                 rfs->itable_buf);
 759                 if (retval) goto errout;
 760
 761                 io_channel_flush(fs->io);
 762                 if (rfs->progress) {
 763                         retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
 764                                                i - adj + 1, max_group);
 765                         if (retval)
 766                                 goto errout;
 767                 }
 768                 group_block += fs->super->s_blocks_per_group;
 769         }
 770         io_channel_flush(fs->io);
 771         retval = 0;
 772
 773 errout:
 774         return retval;
 775 }
 776
 777 /* --------------------------------------------------------------------
 778  *
 779  * Resize processing, phase 2.
 780  *
 781  * In this phase we adjust determine which blocks need to be moved, in
 782  * blocks_to_move().  We then copy the blocks to their ultimate new
 783  * destinations using block_mover().  Since we are copying blocks to
 784  * their new locations, again during this pass we can abort without
 785  * any problems.
 786  * --------------------------------------------------------------------
 787  */
 788
 789 /*
 790  * This helper function creates a block bitmap with all of the
 791  * filesystem meta-data blocks.
 792  */
 793 static errcode_t mark_table_blocks(ext2_filsys fs,
 794                                    ext2fs_block_bitmap bmap)
 795 {
 796         dgrp_t                  i;
 797         blk64_t                 blk;
 798
 799         for (i = 0; i < fs->group_desc_count; i++) {
 800                 ext2fs_reserve_super_and_bgd(fs, i, bmap);
 801
 802                 /*
 803                  * Mark the blocks used for the inode table
 804                  */
 805                 blk = ext2fs_inode_table_loc(fs, i);
 806                 if (blk)
 807                         ext2fs_mark_block_bitmap_range2(bmap, blk,
 808                                                 fs->inode_blocks_per_group);
 809
 810                 /*
 811                  * Mark block used for the block bitmap
 812                  */
 813                 blk = ext2fs_block_bitmap_loc(fs, i);
 814                 if (blk)
 815                         ext2fs_mark_block_bitmap2(bmap, blk);
 816
 817                 /*
 818                  * Mark block used for the inode bitmap
 819                  */
 820                 blk = ext2fs_inode_bitmap_loc(fs, i);
 821                 if (blk)
 822                         ext2fs_mark_block_bitmap2(bmap, blk);
 823         }
 824         return 0;
 825 }
 826
 827 /*
 828  * This function checks to see if a particular block (either a
 829  * superblock or a block group descriptor) overlaps with an inode or
 830  * block bitmap block, or with the inode table.
 831  */
 832 static void mark_fs_metablock(ext2_resize_t rfs,
 833                               ext2fs_block_bitmap meta_bmap,
 834                               int group, blk64_t blk)
 835 {
 836         ext2_filsys     fs = rfs->new_fs;
 837
 838         ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
 839         ext2fs_block_alloc_stats2(fs, blk, +1);
 840
 841         /*
 842          * Check to see if we overlap with the inode or block bitmap,
 843          * or the inode tables.  If not, and the block is in use, then
 844          * mark it as a block to be moved.
 845          */
 846         if (IS_BLOCK_BM(fs, group, blk)) {
 847                 ext2fs_block_bitmap_loc_set(fs, group, 0);
 848                 rfs->needed_blocks++;
 849                 return;
 850         }
 851         if (IS_INODE_BM(fs, group, blk)) {
 852                 ext2fs_inode_bitmap_loc_set(fs, group, 0);
 853                 rfs->needed_blocks++;
 854                 return;
 855         }
 856         if (IS_INODE_TB(fs, group, blk)) {
 857                 ext2fs_inode_table_loc_set(fs, group, 0);
 858                 rfs->needed_blocks++;
 859                 return;
 860         }
 861         if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_FLEX_BG) {
 862                 dgrp_t i;
 863
 864                 for (i=0; i < rfs->old_fs->group_desc_count; i++) {
 865                         if (IS_BLOCK_BM(fs, i, blk)) {
 866                                 ext2fs_block_bitmap_loc_set(fs, i, 0);
 867                                 rfs->needed_blocks++;
 868                                 return;
 869                         }
 870                         if (IS_INODE_BM(fs, i, blk)) {
 871                                 ext2fs_inode_bitmap_loc_set(fs, i, 0);
 872                                 rfs->needed_blocks++;
 873                                 return;
 874                         }
 875                         if (IS_INODE_TB(fs, i, blk)) {
 876                                 ext2fs_inode_table_loc_set(fs, i, 0);
 877                                 rfs->needed_blocks++;
 878                                 return;
 879                         }
 880                 }
 881         }
 882
 883         if (ext2fs_has_group_desc_csum(fs) &&
 884             (ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT))) {
 885                 /*
 886                  * If the block bitmap is uninitialized, which means
 887                  * nothing other than standard metadata in use.
 888                  */
 889                 return;
 890         } else if (ext2fs_test_block_bitmap2(rfs->old_fs->block_map, blk) &&
 891                    !ext2fs_test_block_bitmap2(meta_bmap, blk)) {
 892                 ext2fs_mark_block_bitmap2(rfs->move_blocks, blk);
 893                 rfs->needed_blocks++;
 894         }
 895 }
 896
 897
 898 /*
 899  * This routine marks and unmarks reserved blocks in the new block
 900  * bitmap.  It also determines which blocks need to be moved and
 901  * places this information into the move_blocks bitmap.
 902  */
 903 static errcode_t blocks_to_move(ext2_resize_t rfs)
 904 {
 905         int             j, has_super;
 906         dgrp_t          i, max_groups, g;
 907         blk64_t         blk, group_blk;
 908         blk64_t         old_blocks, new_blocks, group_end, cluster_freed;
 909         blk64_t         new_size;
 910         unsigned int    meta_bg, meta_bg_size;
 911         errcode_t       retval;
 912         ext2_filsys     fs, old_fs;
 913         ext2fs_block_bitmap     meta_bmap, new_meta_bmap = NULL;
 914         int             flex_bg;
 915
 916         fs = rfs->new_fs;
 917         old_fs = rfs->old_fs;
 918         if (ext2fs_blocks_count(old_fs->super) > ext2fs_blocks_count(fs->super))
 919                 fs = rfs->old_fs;
 920
 921         retval = ext2fs_allocate_block_bitmap(fs, _("blocks to be moved"),
 922                                               &rfs->move_blocks);
 923         if (retval)
 924                 return retval;
 925
 926         retval = ext2fs_allocate_block_bitmap(fs, _("meta-data blocks"),
 927                                               &meta_bmap);
 928         if (retval)
 929                 return retval;
 930
 931         retval = mark_table_blocks(old_fs, meta_bmap);
 932         if (retval)
 933                 return retval;
 934
 935         fs = rfs->new_fs;
 936
 937         /*
 938          * If we're shrinking the filesystem, we need to move any
 939          * group's metadata blocks (either allocation bitmaps or the
 940          * inode table) which are beyond the end of the new
 941          * filesystem.
 942          */
 943         new_size = ext2fs_blocks_count(fs->super);
 944         if (new_size < ext2fs_blocks_count(old_fs->super)) {
 945                 for (g = 0; g < fs->group_desc_count; g++) {
 946                         int realloc = 0;
 947                         /*
 948                          * ext2fs_allocate_group_table will re-allocate any
 949                          * metadata blocks whose location is set to zero.
 950                          */
 951                         if (ext2fs_block_bitmap_loc(fs, g) >= new_size) {
 952                                 ext2fs_block_bitmap_loc_set(fs, g, 0);
 953                                 realloc = 1;
 954                         }
 955                         if (ext2fs_inode_bitmap_loc(fs, g) >= new_size) {
 956                                 ext2fs_inode_bitmap_loc_set(fs, g, 0);
 957                                 realloc = 1;
 958                         }
 959                         if ((ext2fs_inode_table_loc(fs, g) +
 960                              fs->inode_blocks_per_group) > new_size) {
 961                                 ext2fs_inode_table_loc_set(fs, g, 0);
 962                                 realloc = 1;
 963                         }
 964
 965                         if (realloc) {
 966                                 retval = ext2fs_allocate_group_table(fs, g, 0);
 967                                 if (retval)
 968                                         return retval;
 969                         }
 970                 }
 971         }
 972
 973         /*
 974          * If we're shrinking the filesystem, we need to move all of
 975          * the blocks that don't fit any more
 976          */
 977         for (blk = ext2fs_blocks_count(fs->super);
 978              blk < ext2fs_blocks_count(old_fs->super); blk++) {
 979                 g = ext2fs_group_of_blk2(fs, blk);
 980                 if (ext2fs_has_group_desc_csum(fs) &&
 981                     ext2fs_bg_flags_test(old_fs, g, EXT2_BG_BLOCK_UNINIT)) {
 982                         /*
 983                          * The block bitmap is uninitialized, so skip
 984                          * to the next block group.
 985                          */
 986                         blk = ext2fs_group_first_block2(fs, g+1) - 1;
 987                         continue;
 988                 }
 989                 if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
 990                     !ext2fs_test_block_bitmap2(meta_bmap, blk)) {
 991                         ext2fs_mark_block_bitmap2(rfs->move_blocks, blk);
 992                         rfs->needed_blocks++;
 993                 }
 994                 ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
 995         }
 996
 997         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) {
 998                 old_blocks = old_fs->super->s_first_meta_bg;
 999                 new_blocks = fs->super->s_first_meta_bg;
1000         } else {
1001                 old_blocks = old_fs->desc_blocks + old_fs->super->s_reserved_gdt_blocks;
1002                 new_blocks = fs->desc_blocks + fs->super->s_reserved_gdt_blocks;
1003         }
1004
1005         retval = reserve_sparse_super2_last_group(rfs, meta_bmap);
1006         if (retval)
1007                 goto errout;
1008
1009         if (old_blocks == new_blocks) {
1010                 retval = 0;
1011                 goto errout;
1012         }
1013
1014         max_groups = fs->group_desc_count;
1015         if (max_groups > old_fs->group_desc_count)
1016                 max_groups = old_fs->group_desc_count;
1017         group_blk = old_fs->super->s_first_data_block;
1018         /*
1019          * If we're reducing the number of descriptor blocks, this
1020          * makes life easy.  :-)   We just have to mark some extra
1021          * blocks as free.
1022          */
1023         if (old_blocks > new_blocks) {
1024                 if (EXT2FS_CLUSTER_RATIO(fs) > 1) {
1025                         retval = ext2fs_allocate_block_bitmap(fs,
1026                                                         _("new meta blocks"),
1027                                                         &new_meta_bmap);
1028                         if (retval)
1029                                 goto errout;
1030
1031                         retval = mark_table_blocks(fs, new_meta_bmap);
1032                         if (retval)
1033                                 goto errout;
1034                 }
1035
1036                 for (i = 0; i < max_groups; i++) {
1037                         if (!ext2fs_bg_has_super(fs, i)) {
1038                                 group_blk += fs->super->s_blocks_per_group;
1039                                 continue;
1040                         }
1041                         group_end = group_blk + 1 + old_blocks;
1042                         for (blk = group_blk + 1 + new_blocks;
1043                              blk < group_end;) {
1044                                 if (new_meta_bmap == NULL ||
1045                                     !ext2fs_test_block_bitmap2(new_meta_bmap,
1046                                                                blk)) {
1047                                         cluster_freed =
1048                                                 EXT2FS_CLUSTER_RATIO(fs) -
1049                                                 (blk &
1050                                                  EXT2FS_CLUSTER_MASK(fs));
1051                                         if (cluster_freed > group_end - blk)
1052                                                 cluster_freed = group_end - blk;
1053                                         ext2fs_block_alloc_stats2(fs, blk, -1);
1054                                         blk += EXT2FS_CLUSTER_RATIO(fs);
1055                                         rfs->needed_blocks -= cluster_freed;
1056                                         continue;
1057                                 }
1058                                 rfs->needed_blocks--;
1059                                 blk++;
1060                         }
1061                         group_blk += fs->super->s_blocks_per_group;
1062                 }
1063                 retval = 0;
1064                 goto errout;
1065         }
1066         /*
1067          * If we're increasing the number of descriptor blocks, life
1068          * gets interesting....
1069          */
1070         meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
1071         flex_bg = fs->super->s_feature_incompat &
1072                 EXT4_FEATURE_INCOMPAT_FLEX_BG;
1073         /* first reserve all of the existing fs meta blocks */
1074         for (i = 0; i < max_groups; i++) {
1075                 has_super = ext2fs_bg_has_super(fs, i);
1076                 if (has_super)
1077                         mark_fs_metablock(rfs, meta_bmap, i, group_blk);
1078
1079                 meta_bg = i / meta_bg_size;
1080                 if (!(fs->super->s_feature_incompat &
1081                       EXT2_FEATURE_INCOMPAT_META_BG) ||
1082                     (meta_bg < fs->super->s_first_meta_bg)) {
1083                         if (has_super) {
1084                                 for (blk = group_blk+1;
1085                                      blk < group_blk + 1 + new_blocks; blk++)
1086                                         mark_fs_metablock(rfs, meta_bmap,
1087                                                           i, blk);
1088                         }
1089                 } else {
1090                         if (has_super)
1091                                 has_super = 1;
1092                         if (((i % meta_bg_size) == 0) ||
1093                             ((i % meta_bg_size) == 1) ||
1094                             ((i % meta_bg_size) == (meta_bg_size-1)))
1095                                 mark_fs_metablock(rfs, meta_bmap, i,
1096                                                   group_blk + has_super);
1097                 }
1098
1099                 /*
1100                  * Reserve the existing meta blocks that we know
1101                  * aren't to be moved.
1102                  *
1103                  * For flex_bg file systems, in order to avoid
1104                  * overwriting fs metadata (especially inode table
1105                  * blocks) belonging to a different block group when
1106                  * we are relocating the inode tables, we need to
1107                  * reserve all existing fs metadata blocks.
1108                  */
1109                 if (ext2fs_block_bitmap_loc(fs, i))
1110                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
1111                                  ext2fs_block_bitmap_loc(fs, i));
1112                 else if (flex_bg && i < old_fs->group_desc_count)
1113                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
1114                                  ext2fs_block_bitmap_loc(old_fs, i));
1115
1116                 if (ext2fs_inode_bitmap_loc(fs, i))
1117                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
1118                                  ext2fs_inode_bitmap_loc(fs, i));
1119                 else if (flex_bg && i < old_fs->group_desc_count)
1120                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
1121                                  ext2fs_inode_bitmap_loc(old_fs, i));
1122
1123                 if (ext2fs_inode_table_loc(fs, i))
1124                         ext2fs_mark_block_bitmap_range2(rfs->reserve_blocks,
1125                                         ext2fs_inode_table_loc(fs, i),
1126                                         fs->inode_blocks_per_group);
1127                 else if (flex_bg && i < old_fs->group_desc_count)
1128                         ext2fs_mark_block_bitmap_range2(rfs->reserve_blocks,
1129                                         ext2fs_inode_table_loc(old_fs, i),
1130                                         old_fs->inode_blocks_per_group);
1131
1132                 group_blk += rfs->new_fs->super->s_blocks_per_group;
1133         }
1134
1135         /* Allocate the missing data structures */
1136         for (i = 0; i < max_groups; i++) {
1137                 if (ext2fs_inode_table_loc(fs, i) &&
1138                     ext2fs_inode_bitmap_loc(fs, i) &&
1139                     ext2fs_block_bitmap_loc(fs, i))
1140                         continue;
1141
1142                 retval = ext2fs_allocate_group_table(fs, i,
1143                                                      rfs->reserve_blocks);
1144                 if (retval)
1145                         goto errout;
1146
1147                 /*
1148                  * For those structures that have changed, we need to
1149                  * do bookkeepping.
1150                  */
1151                 if (ext2fs_block_bitmap_loc(old_fs, i) !=
1152                     (blk = ext2fs_block_bitmap_loc(fs, i))) {
1153                         ext2fs_block_alloc_stats2(fs, blk, +1);
1154                         if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
1155                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
1156                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
1157                                                          blk);
1158                 }
1159                 if (ext2fs_inode_bitmap_loc(old_fs, i) !=
1160                     (blk = ext2fs_inode_bitmap_loc(fs, i))) {
1161                         ext2fs_block_alloc_stats2(fs, blk, +1);
1162                         if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
1163                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
1164                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
1165                                                          blk);
1166                 }
1167
1168                 /*
1169                  * The inode table, if we need to relocate it, is
1170                  * handled specially.  We have to reserve the blocks
1171                  * for both the old and the new inode table, since we
1172                  * can't have the inode table be destroyed during the
1173                  * block relocation phase.
1174                  */
1175                 if (ext2fs_inode_table_loc(fs, i) == ext2fs_inode_table_loc(old_fs, i))
1176                         continue;       /* inode table not moved */
1177
1178                 rfs->needed_blocks += fs->inode_blocks_per_group;
1179
1180                 /*
1181                  * Mark the new inode table as in use in the new block
1182                  * allocation bitmap, and move any blocks that might
1183                  * be necessary.
1184                  */
1185                 for (blk = ext2fs_inode_table_loc(fs, i), j=0;
1186                      j < fs->inode_blocks_per_group ; j++, blk++) {
1187                         ext2fs_block_alloc_stats2(fs, blk, +1);
1188                         if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
1189                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
1190                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
1191                                                          blk);
1192                 }
1193
1194                 /*
1195                  * Make sure the old inode table is reserved in the
1196                  * block reservation bitmap.
1197                  */
1198                 for (blk = ext2fs_inode_table_loc(rfs->old_fs, i), j=0;
1199                      j < fs->inode_blocks_per_group ; j++, blk++)
1200                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
1201         }
1202         retval = 0;
1203
1204 errout:
1205         if (new_meta_bmap)
1206                 ext2fs_free_block_bitmap(new_meta_bmap);
1207         if (meta_bmap)
1208                 ext2fs_free_block_bitmap(meta_bmap);
1209
1210         return retval;
1211 }
1212
1213 /*
1214  * This helper function tries to allocate a new block.  We try to
1215  * avoid hitting the original group descriptor blocks at least at
1216  * first, since we want to make it possible to recover from a badly
1217  * aborted resize operation as much as possible.
1218  *
1219  * In the future, I may further modify this routine to balance out
1220  * where we get the new blocks across the various block groups.
1221  * Ideally we would allocate blocks that corresponded with the block
1222  * group of the containing inode, and keep contiguous blocks
1223  * together.  However, this very difficult to do efficiently, since we
1224  * don't have the necessary information up front.
1225  */
1226
1227 #define AVOID_OLD       1
1228 #define DESPERATION     2
1229
1230 static void init_block_alloc(ext2_resize_t rfs)
1231 {
1232         rfs->alloc_state = AVOID_OLD;
1233         rfs->new_blk = rfs->new_fs->super->s_first_data_block;
1234 #if 0
1235         /* HACK for testing */
1236         if (ext2fs_blocks_count(rfs->new_fs->super) >
1237             ext2fs_blocks_count(rfs->old_fs->super))
1238                 rfs->new_blk = ext2fs_blocks_count(rfs->old_fs->super);
1239 #endif
1240 }
1241
1242 static blk64_t get_new_block(ext2_resize_t rfs)
1243 {
1244         ext2_filsys     fs = rfs->new_fs;
1245
1246         while (1) {
1247                 if (rfs->new_blk >= ext2fs_blocks_count(fs->super)) {
1248                         if (rfs->alloc_state == DESPERATION)
1249                                 return 0;
1250
1251 #ifdef RESIZE2FS_DEBUG
1252                         if (rfs->flags & RESIZE_DEBUG_BMOVE)
1253                                 printf("Going into desperation mode "
1254                                        "for block allocations\n");
1255 #endif
1256                         rfs->alloc_state = DESPERATION;
1257                         rfs->new_blk = fs->super->s_first_data_block;
1258                         continue;
1259                 }
1260                 if (ext2fs_test_block_bitmap2(fs->block_map, rfs->new_blk) ||
1261                     ext2fs_test_block_bitmap2(rfs->reserve_blocks,
1262                                              rfs->new_blk) ||
1263                     ((rfs->alloc_state == AVOID_OLD) &&
1264                      (rfs->new_blk < ext2fs_blocks_count(rfs->old_fs->super)) &&
1265                      ext2fs_test_block_bitmap2(rfs->old_fs->block_map,
1266                                               rfs->new_blk))) {
1267                         rfs->new_blk++;
1268                         continue;
1269                 }
1270                 return rfs->new_blk;
1271         }
1272 }
1273
1274 static errcode_t resize2fs_get_alloc_block(ext2_filsys fs, blk64_t goal,
1275                                            blk64_t *ret)
1276 {
1277         ext2_resize_t rfs = (ext2_resize_t) fs->priv_data;
1278         blk64_t blk;
1279
1280         blk = get_new_block(rfs);
1281         if (!blk)
1282                 return ENOSPC;
1283
1284 #ifdef RESIZE2FS_DEBUG
1285         if (rfs->flags & 0xF)
1286                 printf("get_alloc_block allocating %llu\n", blk);
1287 #endif
1288
1289         ext2fs_mark_block_bitmap2(rfs->old_fs->block_map, blk);
1290         ext2fs_mark_block_bitmap2(rfs->new_fs->block_map, blk);
1291         *ret = (blk64_t) blk;
1292         return 0;
1293 }
1294
1295 static errcode_t block_mover(ext2_resize_t rfs)
1296 {
1297         blk64_t                 blk, old_blk, new_blk;
1298         ext2_filsys             fs = rfs->new_fs;
1299         ext2_filsys             old_fs = rfs->old_fs;
1300         errcode_t               retval;
1301         __u64                   size;
1302         int                     c;
1303         int                     to_move, moved;
1304         ext2_badblocks_list     badblock_list = 0;
1305         int                     bb_modified = 0;
1306
1307         fs->get_alloc_block = resize2fs_get_alloc_block;
1308         old_fs->get_alloc_block = resize2fs_get_alloc_block;
1309
1310         retval = ext2fs_read_bb_inode(old_fs, &badblock_list);
1311         if (retval)
1312                 return retval;
1313
1314         new_blk = fs->super->s_first_data_block;
1315         if (!rfs->itable_buf) {
1316                 retval = ext2fs_get_array(fs->blocksize,
1317                                         fs->inode_blocks_per_group,
1318                                         &rfs->itable_buf);
1319                 if (retval)
1320                         return retval;
1321         }
1322         retval = ext2fs_create_extent_table(&rfs->bmap, 0);
1323         if (retval)
1324                 return retval;
1325
1326         /*
1327          * The first step is to figure out where all of the blocks
1328          * will go.
1329          */
1330         to_move = moved = 0;
1331         init_block_alloc(rfs);
1332         for (blk = B2C(old_fs->super->s_first_data_block);
1333              blk < ext2fs_blocks_count(old_fs->super);
1334              blk += EXT2FS_CLUSTER_RATIO(fs)) {
1335                 if (!ext2fs_test_block_bitmap2(old_fs->block_map, blk))
1336                         continue;
1337                 if (!ext2fs_test_block_bitmap2(rfs->move_blocks, blk))
1338                         continue;
1339                 if (ext2fs_badblocks_list_test(badblock_list, blk)) {
1340                         ext2fs_badblocks_list_del(badblock_list, blk);
1341                         bb_modified++;
1342                         continue;
1343                 }
1344
1345                 new_blk = get_new_block(rfs);
1346                 if (!new_blk) {
1347                         retval = ENOSPC;
1348                         goto errout;
1349                 }
1350                 ext2fs_block_alloc_stats2(fs, new_blk, +1);
1351                 ext2fs_add_extent_entry(rfs->bmap, B2C(blk), B2C(new_blk));
1352                 to_move++;
1353         }
1354
1355         if (to_move == 0) {
1356                 if (rfs->bmap) {
1357                         ext2fs_free_extent_table(rfs->bmap);
1358                         rfs->bmap = 0;
1359                 }
1360                 retval = 0;
1361                 goto errout;
1362         }
1363
1364         /*
1365          * Step two is to actually move the blocks
1366          */
1367         retval =  ext2fs_iterate_extent(rfs->bmap, 0, 0, 0);
1368         if (retval) goto errout;
1369
1370         if (rfs->progress) {
1371                 retval = (rfs->progress)(rfs, E2_RSZ_BLOCK_RELOC_PASS,
1372                                          0, to_move);
1373                 if (retval)
1374                         goto errout;
1375         }
1376         while (1) {
1377                 retval = ext2fs_iterate_extent(rfs->bmap, &old_blk, &new_blk, &size);
1378                 if (retval) goto errout;
1379                 if (!size)
1380                         break;
1381                 old_blk = C2B(old_blk);
1382                 new_blk = C2B(new_blk);
1383                 size = C2B(size);
1384 #ifdef RESIZE2FS_DEBUG
1385                 if (rfs->flags & RESIZE_DEBUG_BMOVE)
1386                         printf("Moving %llu blocks %llu->%llu\n",
1387                                size, old_blk, new_blk);
1388 #endif
1389                 do {
1390                         c = size;
1391                         if (c > fs->inode_blocks_per_group)
1392                                 c = fs->inode_blocks_per_group;
1393                         retval = io_channel_read_blk64(fs->io, old_blk, c,
1394                                                        rfs->itable_buf);
1395                         if (retval) goto errout;
1396                         retval = io_channel_write_blk64(fs->io, new_blk, c,
1397                                                         rfs->itable_buf);
1398                         if (retval) goto errout;
1399                         size -= c;
1400                         new_blk += c;
1401                         old_blk += c;
1402                         moved += c;
1403                         if (rfs->progress) {
1404                                 io_channel_flush(fs->io);
1405                                 retval = (rfs->progress)(rfs,
1406                                                 E2_RSZ_BLOCK_RELOC_PASS,
1407                                                 moved, to_move);
1408                                 if (retval)
1409                                         goto errout;
1410                         }
1411                 } while (size > 0);
1412                 io_channel_flush(fs->io);
1413         }
1414
1415 errout:
1416         if (badblock_list) {
1417                 if (!retval && bb_modified)
1418                         retval = ext2fs_update_bb_inode(old_fs,
1419                                                         badblock_list);
1420                 ext2fs_badblocks_list_free(badblock_list);
1421         }
1422         return retval;
1423 }
1424
1425
1426 /* --------------------------------------------------------------------
1427  *
1428  * Resize processing, phase 3
1429  *
1430  * --------------------------------------------------------------------
1431  */
1432
1433
1434 /*
1435  * The extent translation table is stored in clusters so we need to
1436  * take special care when mapping a source block number to its
1437  * destination block number.
1438  */
1439 static __u64 extent_translate(ext2_filsys fs, ext2_extent extent, __u64 old_loc)
1440 {
1441         __u64 new_block = C2B(ext2fs_extent_translate(extent, B2C(old_loc)));
1442
1443         if (new_block != 0)
1444                 new_block += old_loc & (EXT2FS_CLUSTER_RATIO(fs) - 1);
1445         return new_block;
1446 }
1447
1448 struct process_block_struct {
1449         ext2_resize_t           rfs;
1450         ext2_ino_t              ino;
1451         ext2_ino_t              old_ino;
1452         struct ext2_inode *     inode;
1453         errcode_t               error;
1454         int                     is_dir;
1455         int                     changed;
1456         int                     has_extents;
1457 };
1458
1459 static int process_block(ext2_filsys fs, blk64_t        *block_nr,
1460                          e2_blkcnt_t blockcnt,
1461                          blk64_t ref_block EXT2FS_ATTR((unused)),
1462                          int ref_offset EXT2FS_ATTR((unused)), void *priv_data)
1463 {
1464         struct process_block_struct *pb;
1465         errcode_t       retval;
1466         blk64_t         block, new_block;
1467         int             ret = 0;
1468
1469         pb = (struct process_block_struct *) priv_data;
1470         block = *block_nr;
1471         if (pb->rfs->bmap) {
1472                 new_block = extent_translate(fs, pb->rfs->bmap, block);
1473                 if (new_block) {
1474                         *block_nr = new_block;
1475                         ret |= BLOCK_CHANGED;
1476                         pb->changed = 1;
1477 #ifdef RESIZE2FS_DEBUG
1478                         if (pb->rfs->flags & RESIZE_DEBUG_BMOVE)
1479                                 printf("ino=%u, blockcnt=%lld, %llu->%llu\n",
1480                                        pb->old_ino, blockcnt, block,
1481                                        new_block);
1482 #endif
1483                         block = new_block;
1484                 }
1485         }
1486
1487         /*
1488          * If we moved inodes and metadata_csum is enabled, we must force the
1489          * extent block to be rewritten with new checksum.
1490          */
1491         if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
1492                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
1493             pb->has_extents &&
1494             pb->old_ino != pb->ino)
1495                 ret |= BLOCK_CHANGED;
1496
1497         if (pb->is_dir) {
1498                 retval = ext2fs_add_dir_block2(fs->dblist, pb->ino,
1499                                                block, (int) blockcnt);
1500                 if (retval) {
1501                         pb->error = retval;
1502                         ret |= BLOCK_ABORT;
1503                 }
1504         }
1505         return ret;
1506 }
1507
1508 /*
1509  * Progress callback
1510  */
1511 static errcode_t progress_callback(ext2_filsys fs,
1512                                    ext2_inode_scan scan EXT2FS_ATTR((unused)),
1513                                    dgrp_t group, void * priv_data)
1514 {
1515         ext2_resize_t rfs = (ext2_resize_t) priv_data;
1516         errcode_t               retval;
1517
1518         /*
1519          * This check is to protect against old ext2 libraries.  It
1520          * shouldn't be needed against new libraries.
1521          */
1522         if ((group+1) == 0)
1523                 return 0;
1524
1525         if (rfs->progress) {
1526                 io_channel_flush(fs->io);
1527                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
1528                                          group+1, fs->group_desc_count);
1529                 if (retval)
1530                         return retval;
1531         }
1532
1533         return 0;
1534 }
1535
1536 static errcode_t migrate_ea_block(ext2_resize_t rfs, ext2_ino_t ino,
1537                                   struct ext2_inode *inode, int *changed)
1538 {
1539         char *buf;
1540         blk64_t new_block;
1541         errcode_t err = 0;
1542
1543         /* No EA block or no remapping?  Quit early. */
1544         if (ext2fs_file_acl_block(rfs->old_fs, inode) == 0 && !rfs->bmap)
1545                 return 0;
1546         new_block = extent_translate(rfs->old_fs, rfs->bmap,
1547                 ext2fs_file_acl_block(rfs->old_fs, inode));
1548         if (new_block == 0)
1549                 return 0;
1550
1551         /* Set the new ACL block */
1552         ext2fs_file_acl_block_set(rfs->old_fs, inode, new_block);
1553
1554         /* Update checksum */
1555         if (EXT2_HAS_RO_COMPAT_FEATURE(rfs->new_fs->super,
1556                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
1557                 err = ext2fs_get_mem(rfs->old_fs->blocksize, &buf);
1558                 if (err)
1559                         return err;
1560                 rfs->old_fs->flags |= EXT2_FLAG_IGNORE_CSUM_ERRORS;
1561                 err = ext2fs_read_ext_attr3(rfs->old_fs, new_block, buf, ino);
1562                 rfs->old_fs->flags &= ~EXT2_FLAG_IGNORE_CSUM_ERRORS;
1563                 if (err)
1564                         goto out;
1565                 err = ext2fs_write_ext_attr3(rfs->old_fs, new_block, buf, ino);
1566                 if (err)
1567                         goto out;
1568         }
1569         *changed = 1;
1570
1571 out:
1572         ext2fs_free_mem(&buf);
1573         return err;
1574 }
1575
1576 static errcode_t inode_scan_and_fix(ext2_resize_t rfs)
1577 {
1578         struct process_block_struct     pb;
1579         ext2_ino_t              ino, new_inode;
1580         struct ext2_inode       *inode = NULL;
1581         ext2_inode_scan         scan = NULL;
1582         errcode_t               retval;
1583         char                    *block_buf = 0;
1584         ext2_ino_t              start_to_move;
1585         blk64_t                 orig_size;
1586         int                     inode_size;
1587
1588         if ((rfs->old_fs->group_desc_count <=
1589              rfs->new_fs->group_desc_count) &&
1590             !rfs->bmap)
1591                 return 0;
1592
1593         /*
1594          * Save the original size of the old filesystem, and
1595          * temporarily set the size to be the new size if the new size
1596          * is larger.  We need to do this to avoid catching an error
1597          * by the block iterator routines
1598          */
1599         orig_size = ext2fs_blocks_count(rfs->old_fs->super);
1600         if (orig_size < ext2fs_blocks_count(rfs->new_fs->super))
1601                 ext2fs_blocks_count_set(rfs->old_fs->super,
1602                                 ext2fs_blocks_count(rfs->new_fs->super));
1603
1604         retval = ext2fs_open_inode_scan(rfs->old_fs, 0, &scan);
1605         if (retval) goto errout;
1606
1607         retval = ext2fs_init_dblist(rfs->old_fs, 0);
1608         if (retval) goto errout;
1609         retval = ext2fs_get_array(rfs->old_fs->blocksize, 3, &block_buf);
1610         if (retval) goto errout;
1611
1612         start_to_move = (rfs->new_fs->group_desc_count *
1613                          rfs->new_fs->super->s_inodes_per_group);
1614
1615         if (rfs->progress) {
1616                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
1617                                          0, rfs->old_fs->group_desc_count);
1618                 if (retval)
1619                         goto errout;
1620         }
1621         ext2fs_set_inode_callback(scan, progress_callback, (void *) rfs);
1622         pb.rfs = rfs;
1623         pb.inode = inode;
1624         pb.error = 0;
1625         new_inode = EXT2_FIRST_INODE(rfs->new_fs->super);
1626         inode_size = EXT2_INODE_SIZE(rfs->new_fs->super);
1627         inode = malloc(inode_size);
1628         if (!inode) {
1629                 retval = ENOMEM;
1630                 goto errout;
1631         }
1632         /*
1633          * First, copy all of the inodes that need to be moved
1634          * elsewhere in the inode table
1635          */
1636         while (1) {
1637                 retval = ext2fs_get_next_inode_full(scan, &ino, inode, inode_size);
1638                 if (retval) goto errout;
1639                 if (!ino)
1640                         break;
1641
1642                 if (inode->i_links_count == 0 && ino != EXT2_RESIZE_INO)
1643                         continue; /* inode not in use */
1644
1645                 pb.is_dir = LINUX_S_ISDIR(inode->i_mode);
1646                 pb.changed = 0;
1647
1648                 /* Remap EA block */
1649                 retval = migrate_ea_block(rfs, ino, inode, &pb.changed);
1650                 if (retval)
1651                         goto errout;
1652
1653                 new_inode = ino;
1654                 if (ino <= start_to_move)
1655                         goto remap_blocks; /* Don't need to move inode. */
1656
1657                 /*
1658                  * Find a new inode.  Now that extents and directory blocks
1659                  * are tied to the inode number through the checksum, we must
1660                  * set up the new inode before we start rewriting blocks.
1661                  */
1662                 retval = ext2fs_new_inode(rfs->new_fs, 0, 0, 0, &new_inode);
1663                 if (retval)
1664                         goto errout;
1665
1666                 ext2fs_inode_alloc_stats2(rfs->new_fs, new_inode, +1,
1667                                           pb.is_dir);
1668                 inode->i_ctime = time(0);
1669                 retval = ext2fs_write_inode_full(rfs->old_fs, new_inode,
1670                                                 inode, inode_size);
1671                 if (retval)
1672                         goto errout;
1673                 pb.changed = 0;
1674
1675 #ifdef RESIZE2FS_DEBUG
1676                 if (rfs->flags & RESIZE_DEBUG_INODEMAP)
1677                         printf("Inode moved %u->%u\n", ino, new_inode);
1678 #endif
1679                 if (!rfs->imap) {
1680                         retval = ext2fs_create_extent_table(&rfs->imap, 0);
1681                         if (retval)
1682                                 goto errout;
1683                 }
1684                 ext2fs_add_extent_entry(rfs->imap, ino, new_inode);
1685
1686 remap_blocks:
1687                 if (pb.changed)
1688                         retval = ext2fs_write_inode_full(rfs->old_fs,
1689                                                          new_inode,
1690                                                          inode, inode_size);
1691                 if (retval)
1692                         goto errout;
1693
1694                 /*
1695                  * Update inodes to point to new blocks; schedule directory
1696                  * blocks for inode remapping.  Need to write out dir blocks
1697                  * with new inode numbers if we have metadata_csum enabled.
1698                  */
1699                 if (ext2fs_inode_has_valid_blocks2(rfs->old_fs, inode) &&
1700                     (rfs->bmap || pb.is_dir)) {
1701                         pb.ino = new_inode;
1702                         pb.old_ino = ino;
1703                         pb.has_extents = inode->i_flags & EXT4_EXTENTS_FL;
1704                         rfs->old_fs->flags |= EXT2_FLAG_IGNORE_CSUM_ERRORS;
1705                         retval = ext2fs_block_iterate3(rfs->old_fs,
1706                                                        new_inode, 0, block_buf,
1707                                                        process_block, &pb);
1708                         rfs->old_fs->flags &= ~EXT2_FLAG_IGNORE_CSUM_ERRORS;
1709                         if (retval)
1710                                 goto errout;
1711                         if (pb.error) {
1712                                 retval = pb.error;
1713                                 goto errout;
1714                         }
1715                 } else if ((inode->i_flags & EXT4_INLINE_DATA_FL) &&
1716                            (rfs->bmap || pb.is_dir)) {
1717                         /* inline data dir; update it too */
1718                         retval = ext2fs_add_dir_block2(rfs->old_fs->dblist,
1719                                                        new_inode, 0, 0);
1720                         if (retval)
1721                                 goto errout;
1722                 }
1723         }
1724         io_channel_flush(rfs->old_fs->io);
1725
1726 errout:
1727         ext2fs_blocks_count_set(rfs->old_fs->super, orig_size);
1728         if (rfs->bmap) {
1729                 ext2fs_free_extent_table(rfs->bmap);
1730                 rfs->bmap = 0;
1731         }
1732         if (scan)
1733                 ext2fs_close_inode_scan(scan);
1734         if (block_buf)
1735                 ext2fs_free_mem(&block_buf);
1736         free(inode);
1737         return retval;
1738 }
1739
1740 /* --------------------------------------------------------------------
1741  *
1742  * Resize processing, phase 4.
1743  *
1744  * --------------------------------------------------------------------
1745  */
1746
1747 struct istruct {
1748         ext2_resize_t rfs;
1749         errcode_t       err;
1750         unsigned int    max_dirs;
1751         unsigned int    num;
1752 };
1753
1754 static int check_and_change_inodes(ext2_ino_t dir,
1755                                    int entry EXT2FS_ATTR((unused)),
1756                                    struct ext2_dir_entry *dirent, int offset,
1757                                    int  blocksize EXT2FS_ATTR((unused)),
1758                                    char *buf EXT2FS_ATTR((unused)),
1759                                    void *priv_data)
1760 {
1761         struct istruct *is = (struct istruct *) priv_data;
1762         struct ext2_inode       inode;
1763         ext2_ino_t              new_inode;
1764         errcode_t               retval;
1765         int                     ret = 0;
1766
1767         if (is->rfs->progress && offset == 0) {
1768                 io_channel_flush(is->rfs->old_fs->io);
1769                 is->err = (is->rfs->progress)(is->rfs,
1770                                               E2_RSZ_INODE_REF_UPD_PASS,
1771                                               ++is->num, is->max_dirs);
1772                 if (is->err)
1773                         return DIRENT_ABORT;
1774         }
1775
1776         /*
1777          * If we have checksums enabled and the inode wasn't present in the
1778          * old fs, then we must rewrite all dir blocks with new checksums.
1779          */
1780         if (EXT2_HAS_RO_COMPAT_FEATURE(is->rfs->old_fs->super,
1781                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
1782             !ext2fs_test_inode_bitmap2(is->rfs->old_fs->inode_map, dir))
1783                 ret |= DIRENT_CHANGED;
1784
1785         if (!dirent->inode)
1786                 return ret;
1787
1788         new_inode = ext2fs_extent_translate(is->rfs->imap, dirent->inode);
1789
1790         if (!new_inode)
1791                 return ret;
1792 #ifdef RESIZE2FS_DEBUG
1793         if (is->rfs->flags & RESIZE_DEBUG_INODEMAP)
1794                 printf("Inode translate (dir=%u, name=%.*s, %u->%u)\n",
1795                        dir, ext2fs_dirent_name_len(dirent), dirent->name,
1796                        dirent->inode, new_inode);
1797 #endif
1798
1799         dirent->inode = new_inode;
1800
1801         /* Update the directory mtime and ctime */
1802         retval = ext2fs_read_inode(is->rfs->old_fs, dir, &inode);
1803         if (retval == 0) {
1804                 inode.i_mtime = inode.i_ctime = time(0);
1805                 is->err = ext2fs_write_inode(is->rfs->old_fs, dir, &inode);
1806                 if (is->err)
1807                         return ret | DIRENT_ABORT;
1808         }
1809
1810         return ret | DIRENT_CHANGED;
1811 }
1812
1813 static errcode_t inode_ref_fix(ext2_resize_t rfs)
1814 {
1815         errcode_t               retval;
1816         struct istruct          is;
1817
1818         if (!rfs->imap)
1819                 return 0;
1820
1821         /*
1822          * Now, we iterate over all of the directories to update the
1823          * inode references
1824          */
1825         is.num = 0;
1826         is.max_dirs = ext2fs_dblist_count2(rfs->old_fs->dblist);
1827         is.rfs = rfs;
1828         is.err = 0;
1829
1830         if (rfs->progress) {
1831                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS,
1832                                          0, is.max_dirs);
1833                 if (retval)
1834                         goto errout;
1835         }
1836
1837         rfs->old_fs->flags |= EXT2_FLAG_IGNORE_CSUM_ERRORS;
1838         retval = ext2fs_dblist_dir_iterate(rfs->old_fs->dblist,
1839                                            DIRENT_FLAG_INCLUDE_EMPTY, 0,
1840                                            check_and_change_inodes, &is);
1841         rfs->old_fs->flags &= ~EXT2_FLAG_IGNORE_CSUM_ERRORS;
1842         if (retval)
1843                 goto errout;
1844         if (is.err) {
1845                 retval = is.err;
1846                 goto errout;
1847         }
1848
1849         if (rfs->progress && (is.num < is.max_dirs))
1850                 (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS,
1851                                 is.max_dirs, is.max_dirs);
1852
1853 errout:
1854         ext2fs_free_extent_table(rfs->imap);
1855         rfs->imap = 0;
1856         return retval;
1857 }
1858
1859
1860 /* --------------------------------------------------------------------
1861  *
1862  * Resize processing, phase 5.
1863  *
1864  * In this phase we actually move the inode table around, and then
1865  * update the summary statistics.  This is scary, since aborting here
1866  * will potentially scramble the filesystem.  (We are moving the
1867  * inode tables around in place, and so the potential for lost data,
1868  * or at the very least scrambling the mapping between filenames and
1869  * inode numbers is very high in case of a power failure here.)
1870  * --------------------------------------------------------------------
1871  */
1872
1873
1874 /*
1875  * A very scary routine --- this one moves the inode table around!!!
1876  *
1877  * After this you have to use the rfs->new_fs file handle to read and
1878  * write inodes.
1879  */
1880 static errcode_t move_itables(ext2_resize_t rfs)
1881 {
1882         int             n, num, size;
1883         long long       diff;
1884         dgrp_t          i, max_groups;
1885         ext2_filsys     fs = rfs->new_fs;
1886         char            *cp;
1887         blk64_t         old_blk, new_blk, blk, cluster_freed;
1888         errcode_t       retval;
1889         int             j, to_move, moved;
1890         ext2fs_block_bitmap     new_bmap = NULL;
1891
1892         max_groups = fs->group_desc_count;
1893         if (max_groups > rfs->old_fs->group_desc_count)
1894                 max_groups = rfs->old_fs->group_desc_count;
1895
1896         size = fs->blocksize * fs->inode_blocks_per_group;
1897         if (!rfs->itable_buf) {
1898                 retval = ext2fs_get_mem(size, &rfs->itable_buf);
1899                 if (retval)
1900                         return retval;
1901         }
1902
1903         if (EXT2FS_CLUSTER_RATIO(fs) > 1) {
1904                 retval = ext2fs_allocate_block_bitmap(fs, _("new meta blocks"),
1905                                                       &new_bmap);
1906                 if (retval)
1907                         return retval;
1908
1909                 retval = mark_table_blocks(fs, new_bmap);
1910                 if (retval)
1911                         goto errout;
1912         }
1913
1914         /*
1915          * Figure out how many inode tables we need to move
1916          */
1917         to_move = moved = 0;
1918         for (i=0; i < max_groups; i++)
1919                 if (ext2fs_inode_table_loc(rfs->old_fs, i) !=
1920                     ext2fs_inode_table_loc(fs, i))
1921                         to_move++;
1922
1923         if (to_move == 0)
1924                 return 0;
1925
1926         if (rfs->progress) {
1927                 retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
1928                                        0, to_move);
1929                 if (retval)
1930                         goto errout;
1931         }
1932
1933         rfs->old_fs->flags |= EXT2_FLAG_MASTER_SB_ONLY;
1934
1935         for (i=0; i < max_groups; i++) {
1936                 old_blk = ext2fs_inode_table_loc(rfs->old_fs, i);
1937                 new_blk = ext2fs_inode_table_loc(fs, i);
1938                 diff = new_blk - old_blk;
1939
1940 #ifdef RESIZE2FS_DEBUG
1941                 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1942                         printf("Itable move group %d block %llu->%llu (diff %lld)\n",
1943                                i, old_blk, new_blk, diff);
1944 #endif
1945
1946                 if (!diff)
1947                         continue;
1948
1949                 retval = io_channel_read_blk64(fs->io, old_blk,
1950                                                fs->inode_blocks_per_group,
1951                                                rfs->itable_buf);
1952                 if (retval)
1953                         goto errout;
1954                 /*
1955                  * The end of the inode table segment often contains
1956                  * all zeros, and we're often only moving the inode
1957                  * table down a block or two.  If so, we can optimize
1958                  * things by not rewriting blocks that we know to be zero
1959                  * already.
1960                  */
1961                 for (cp = rfs->itable_buf+size-1, n=0; n < size; n++, cp--)
1962                         if (*cp)
1963                                 break;
1964                 n = n >> EXT2_BLOCK_SIZE_BITS(fs->super);
1965 #ifdef RESIZE2FS_DEBUG
1966                 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1967                         printf("%d blocks of zeros...\n", n);
1968 #endif
1969                 num = fs->inode_blocks_per_group;
1970                 if (n > diff)
1971                         num -= n;
1972
1973                 retval = io_channel_write_blk64(fs->io, new_blk,
1974                                                 num, rfs->itable_buf);
1975                 if (retval) {
1976                         io_channel_write_blk64(fs->io, old_blk,
1977                                                num, rfs->itable_buf);
1978                         goto errout;
1979                 }
1980                 if (n > diff) {
1981                         retval = io_channel_write_blk64(fs->io,
1982                               old_blk + fs->inode_blocks_per_group,
1983                               diff, (rfs->itable_buf +
1984                                      (fs->inode_blocks_per_group - diff) *
1985                                      fs->blocksize));
1986                         if (retval)
1987                                 goto errout;
1988                 }
1989
1990                 for (blk = ext2fs_inode_table_loc(rfs->old_fs, i), j=0;
1991                      j < fs->inode_blocks_per_group;) {
1992                         if (new_bmap == NULL ||
1993                             !ext2fs_test_block_bitmap2(new_bmap, blk)) {
1994                                 ext2fs_block_alloc_stats2(fs, blk, -1);
1995                                 cluster_freed = EXT2FS_CLUSTER_RATIO(fs) -
1996                                                 (blk & EXT2FS_CLUSTER_MASK(fs));
1997                                 blk += cluster_freed;
1998                                 j += cluster_freed;
1999                                 continue;
2000                         }
2001                         blk++;
2002                         j++;
2003                 }
2004
2005                 ext2fs_inode_table_loc_set(rfs->old_fs, i, new_blk);
2006                 ext2fs_group_desc_csum_set(rfs->old_fs, i);
2007                 ext2fs_mark_super_dirty(rfs->old_fs);
2008                 ext2fs_flush(rfs->old_fs);
2009
2010                 if (rfs->progress) {
2011                         retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
2012                                                ++moved, to_move);
2013                         if (retval)
2014                                 goto errout;
2015                 }
2016         }
2017         mark_table_blocks(fs, fs->block_map);
2018         ext2fs_flush(fs);
2019 #ifdef RESIZE2FS_DEBUG
2020         if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
2021                 printf("Inode table move finished.\n");
2022 #endif
2023         retval = 0;
2024
2025 errout:
2026         if (new_bmap)
2027                 ext2fs_free_block_bitmap(new_bmap);
2028         return retval;
2029 }
2030
2031 /*
2032  * This function is used when expanding a file system.  It frees the
2033  * superblock and block group descriptor blocks from the block group
2034  * which is no longer the last block group.
2035  */
2036 static errcode_t clear_sparse_super2_last_group(ext2_resize_t rfs)
2037 {
2038         ext2_filsys     fs = rfs->new_fs;
2039         ext2_filsys     old_fs = rfs->old_fs;
2040         errcode_t       retval;
2041         dgrp_t          old_last_bg = rfs->old_fs->group_desc_count - 1;
2042         dgrp_t          last_bg = fs->group_desc_count - 1;
2043         blk64_t         sb, old_desc;
2044         blk_t           num;
2045
2046         if (!(fs->super->s_feature_compat & EXT4_FEATURE_COMPAT_SPARSE_SUPER2))
2047                 return 0;
2048
2049         if (last_bg <= old_last_bg)
2050                 return 0;
2051
2052         if (fs->super->s_backup_bgs[0] == old_fs->super->s_backup_bgs[0] &&
2053             fs->super->s_backup_bgs[1] == old_fs->super->s_backup_bgs[1])
2054                 return 0;
2055
2056         if (old_fs->super->s_backup_bgs[0] != old_last_bg &&
2057             old_fs->super->s_backup_bgs[1] != old_last_bg)
2058                 return 0;
2059
2060         if (fs->super->s_backup_bgs[0] == old_last_bg ||
2061             fs->super->s_backup_bgs[1] == old_last_bg)
2062                 return 0;
2063
2064         retval = ext2fs_super_and_bgd_loc2(rfs->old_fs, old_last_bg,
2065                                            &sb, &old_desc, NULL, &num);
2066         if (retval)
2067                 return retval;
2068
2069         if (sb)
2070                 ext2fs_unmark_block_bitmap2(fs->block_map, sb);
2071         if (old_desc)
2072                 ext2fs_unmark_block_bitmap_range2(fs->block_map, old_desc, num);
2073         return 0;
2074 }
2075
2076 /*
2077  * This function is used when shrinking a file system.  We need to
2078  * utilize blocks from what will be the new last block group for the
2079  * backup superblock and block group descriptor blocks.
2080  * Unfortunately, those blocks may be used by other files or fs
2081  * metadata blocks.  We need to mark them as being in use.
2082  */
2083 static errcode_t reserve_sparse_super2_last_group(ext2_resize_t rfs,
2084                                                  ext2fs_block_bitmap meta_bmap)
2085 {
2086         ext2_filsys     fs = rfs->new_fs;
2087         ext2_filsys     old_fs = rfs->old_fs;
2088         errcode_t       retval;
2089         dgrp_t          old_last_bg = rfs->old_fs->group_desc_count - 1;
2090         dgrp_t          last_bg = fs->group_desc_count - 1;
2091         dgrp_t          g;
2092         blk64_t         blk, sb, old_desc;
2093         blk_t           i, num;
2094         int             realloc = 0;
2095
2096         if (!(fs->super->s_feature_compat & EXT4_FEATURE_COMPAT_SPARSE_SUPER2))
2097                 return 0;
2098
2099         if (last_bg >= old_last_bg)
2100                 return 0;
2101
2102         if (fs->super->s_backup_bgs[0] == old_fs->super->s_backup_bgs[0] &&
2103             fs->super->s_backup_bgs[1] == old_fs->super->s_backup_bgs[1])
2104                 return 0;
2105
2106         if (fs->super->s_backup_bgs[0] != last_bg &&
2107             fs->super->s_backup_bgs[1] != last_bg)
2108                 return 0;
2109
2110         if (old_fs->super->s_backup_bgs[0] == last_bg ||
2111             old_fs->super->s_backup_bgs[1] == last_bg)
2112                 return 0;
2113
2114         retval = ext2fs_super_and_bgd_loc2(rfs->new_fs, last_bg,
2115                                            &sb, &old_desc, NULL, &num);
2116         if (retval)
2117                 return retval;
2118
2119         if (!sb) {
2120                 fputs(_("Should never happen!  No sb in last super_sparse bg?\n"),
2121                       stderr);
2122                 exit(1);
2123         }
2124         if (old_desc != sb+1) {
2125                 fputs(_("Should never happen!  Unexpected old_desc in "
2126                         "super_sparse bg?\n"),
2127                       stderr);
2128                 exit(1);
2129         }
2130         num = (old_desc) ? num : 1;
2131
2132         /* Reserve the backup blocks */
2133         ext2fs_mark_block_bitmap_range2(fs->block_map, sb, num);
2134
2135         for (g = 0; g < fs->group_desc_count; g++) {
2136                 blk64_t mb;
2137
2138                 mb = ext2fs_block_bitmap_loc(fs, g);
2139                 if ((mb >= sb) && (mb < sb + num)) {
2140                         ext2fs_block_bitmap_loc_set(fs, g, 0);
2141                         realloc = 1;
2142                 }
2143                 mb = ext2fs_inode_bitmap_loc(fs, g);
2144                 if ((mb >= sb) && (mb < sb + num)) {
2145                         ext2fs_inode_bitmap_loc_set(fs, g, 0);
2146                         realloc = 1;
2147                 }
2148                 mb = ext2fs_inode_table_loc(fs, g);
2149                 if ((mb < sb + num) &&
2150                     (sb < mb + fs->inode_blocks_per_group)) {
2151                         ext2fs_inode_table_loc_set(fs, g, 0);
2152                         realloc = 1;
2153                 }
2154                 if (realloc) {
2155                         retval = ext2fs_allocate_group_table(fs, g, 0);
2156                         if (retval)
2157                                 return retval;
2158                 }
2159         }
2160
2161         for (blk = sb, i = 0; i < num; blk++, i++) {
2162                 if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
2163                     !ext2fs_test_block_bitmap2(meta_bmap, blk)) {
2164                         ext2fs_mark_block_bitmap2(rfs->move_blocks, blk);
2165                         rfs->needed_blocks++;
2166                 }
2167                 ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
2168         }
2169         return 0;
2170 }
2171
2172 /*
2173  * Fix the resize inode
2174  */
2175 static errcode_t fix_resize_inode(ext2_filsys fs)
2176 {
2177         struct ext2_inode       inode;
2178         errcode_t               retval;
2179         char                    *block_buf = NULL;
2180
2181         if (!(fs->super->s_feature_compat &
2182               EXT2_FEATURE_COMPAT_RESIZE_INODE))
2183                 return 0;
2184
2185         retval = ext2fs_get_mem(fs->blocksize, &block_buf);
2186         if (retval) goto errout;
2187
2188         retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode);
2189         if (retval) goto errout;
2190
2191         ext2fs_iblk_set(fs, &inode, 1);
2192
2193         retval = ext2fs_write_inode(fs, EXT2_RESIZE_INO, &inode);
2194         if (retval) goto errout;
2195
2196         if (!inode.i_block[EXT2_DIND_BLOCK]) {
2197                 /*
2198                  * Avoid zeroing out block #0; that's rude.  This
2199                  * should never happen anyway since the filesystem
2200                  * should be fsck'ed and we assume it is consistent.
2201                  */
2202                 fprintf(stderr, "%s",
2203                         _("Should never happen: resize inode corrupt!\n"));
2204                 exit(1);
2205         }
2206
2207         memset(block_buf, 0, fs->blocksize);
2208
2209         retval = io_channel_write_blk64(fs->io, inode.i_block[EXT2_DIND_BLOCK],
2210                                         1, block_buf);
2211         if (retval) goto errout;
2212
2213         retval = ext2fs_create_resize_inode(fs);
2214         if (retval)
2215                 goto errout;
2216
2217 errout:
2218         if (block_buf)
2219                 ext2fs_free_mem(&block_buf);
2220         return retval;
2221 }
2222
2223 /*
2224  * Finally, recalculate the summary information
2225  */
2226 static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs)
2227 {
2228         blk64_t         blk;
2229         ext2_ino_t      ino;
2230         unsigned int    group = 0;
2231         unsigned int    count = 0;
2232         blk64_t         total_blocks_free = 0;
2233         int             total_inodes_free = 0;
2234         int             group_free = 0;
2235         int             uninit = 0;
2236         blk64_t         super_blk, old_desc_blk, new_desc_blk;
2237         int             old_desc_blocks;
2238
2239         /*
2240          * First calculate the block statistics
2241          */
2242         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT);
2243         ext2fs_super_and_bgd_loc2(fs, group, &super_blk, &old_desc_blk,
2244                                   &new_desc_blk, 0);
2245         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
2246                 old_desc_blocks = fs->super->s_first_meta_bg;
2247         else
2248                 old_desc_blocks = fs->desc_blocks +
2249                         fs->super->s_reserved_gdt_blocks;
2250         for (blk = B2C(fs->super->s_first_data_block);
2251              blk < ext2fs_blocks_count(fs->super);
2252              blk += EXT2FS_CLUSTER_RATIO(fs)) {
2253                 if ((uninit &&
2254                      !(EQ_CLSTR(blk, super_blk) ||
2255                        ((old_desc_blk && old_desc_blocks &&
2256                          GE_CLSTR(blk, old_desc_blk) &&
2257                          LT_CLSTR(blk, old_desc_blk + old_desc_blocks))) ||
2258                        ((new_desc_blk && EQ_CLSTR(blk, new_desc_blk))) ||
2259                        EQ_CLSTR(blk, ext2fs_block_bitmap_loc(fs, group)) ||
2260                        EQ_CLSTR(blk, ext2fs_inode_bitmap_loc(fs, group)) ||
2261                        ((GE_CLSTR(blk, ext2fs_inode_table_loc(fs, group)) &&
2262                          LT_CLSTR(blk, ext2fs_inode_table_loc(fs, group)
2263                                   + fs->inode_blocks_per_group))))) ||
2264                     (!ext2fs_fast_test_block_bitmap2(fs->block_map, blk))) {
2265                         group_free++;
2266                         total_blocks_free++;
2267                 }
2268                 count++;
2269                 if ((count == fs->super->s_clusters_per_group) ||
2270                     EQ_CLSTR(blk, ext2fs_blocks_count(fs->super)-1)) {
2271                         ext2fs_bg_free_blocks_count_set(fs, group, group_free);
2272                         ext2fs_group_desc_csum_set(fs, group);
2273                         group++;
2274                         if (group >= fs->group_desc_count)
2275                                 break;
2276                         count = 0;
2277                         group_free = 0;
2278                         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT);
2279                         ext2fs_super_and_bgd_loc2(fs, group, &super_blk,
2280                                                   &old_desc_blk,
2281                                                   &new_desc_blk, 0);
2282                         if (fs->super->s_feature_incompat &
2283                             EXT2_FEATURE_INCOMPAT_META_BG)
2284                                 old_desc_blocks = fs->super->s_first_meta_bg;
2285                         else
2286                                 old_desc_blocks = fs->desc_blocks +
2287                                         fs->super->s_reserved_gdt_blocks;
2288                 }
2289         }
2290         total_blocks_free = C2B(total_blocks_free);
2291         ext2fs_free_blocks_count_set(fs->super, total_blocks_free);
2292
2293         /*
2294          * Next, calculate the inode statistics
2295          */
2296         group_free = 0;
2297         count = 0;
2298         group = 0;
2299
2300         /* Protect loop from wrap-around if s_inodes_count maxed */
2301         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT);
2302         for (ino = 1; ino <= fs->super->s_inodes_count && ino > 0; ino++) {
2303                 if (uninit ||
2304                     !ext2fs_fast_test_inode_bitmap2(fs->inode_map, ino)) {
2305                         group_free++;
2306                         total_inodes_free++;
2307                 }
2308                 count++;
2309                 if ((count == fs->super->s_inodes_per_group) ||
2310                     (ino == fs->super->s_inodes_count)) {
2311                         ext2fs_bg_free_inodes_count_set(fs, group, group_free);
2312                         ext2fs_group_desc_csum_set(fs, group);
2313                         group++;
2314                         if (group >= fs->group_desc_count)
2315                                 break;
2316                         count = 0;
2317                         group_free = 0;
2318                         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT);
2319                 }
2320         }
2321         fs->super->s_free_inodes_count = total_inodes_free;
2322         ext2fs_mark_super_dirty(fs);
2323         return 0;
2324 }
2325
2326 /*
2327  *  Journal may have been relocated; update the backup journal blocks
2328  *  in the superblock.
2329  */
2330 static errcode_t fix_sb_journal_backup(ext2_filsys fs)
2331 {
2332         errcode_t         retval;
2333         struct ext2_inode inode;
2334
2335         if (!(fs->super->s_feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL))
2336                 return 0;
2337
2338         /* External journal? Nothing to do. */
2339         if (fs->super->s_journal_dev && !fs->super->s_journal_inum)
2340                 return 0;
2341
2342         retval = ext2fs_read_inode(fs, fs->super->s_journal_inum, &inode);
2343         if (retval)
2344                 return retval;
2345         memcpy(fs->super->s_jnl_blocks, inode.i_block, EXT2_N_BLOCKS*4);
2346         fs->super->s_jnl_blocks[15] = inode.i_size_high;
2347         fs->super->s_jnl_blocks[16] = inode.i_size;
2348         fs->super->s_jnl_backup_type = EXT3_JNL_BACKUP_BLOCKS;
2349         ext2fs_mark_super_dirty(fs);
2350         return 0;
2351 }
2352
2353 static int calc_group_overhead(ext2_filsys fs, blk64_t grp,
2354                                int old_desc_blocks)
2355 {
2356         blk64_t super_blk, old_desc_blk, new_desc_blk;
2357         int overhead;
2358
2359         /* inode table blocks plus allocation bitmaps */
2360         overhead = fs->inode_blocks_per_group + 2;
2361
2362         ext2fs_super_and_bgd_loc2(fs, grp, &super_blk,
2363                                   &old_desc_blk, &new_desc_blk, 0);
2364         if ((grp == 0) || super_blk)
2365                 overhead++;
2366         if (old_desc_blk)
2367                 overhead += old_desc_blocks;
2368         else if (new_desc_blk)
2369                 overhead++;
2370         return overhead;
2371 }
2372
2373
2374 /*
2375  * calcluate the minimum number of blocks the given fs can be resized to
2376  */
2377 blk64_t calculate_minimum_resize_size(ext2_filsys fs, int flags)
2378 {
2379         ext2_ino_t inode_count;
2380         dgrp_t groups;
2381         blk64_t blks_needed, data_blocks;
2382         blk64_t grp, data_needed, last_start;
2383         blk64_t overhead = 0;
2384         int old_desc_blocks;
2385         int extra_groups = 0;
2386         int flexbg_size = 1 << fs->super->s_log_groups_per_flex;
2387
2388         /*
2389          * first figure out how many group descriptors we need to
2390          * handle the number of inodes we have
2391          */
2392         inode_count = fs->super->s_inodes_count -
2393                 fs->super->s_free_inodes_count;
2394         blks_needed = ext2fs_div_ceil(inode_count,
2395                                       fs->super->s_inodes_per_group) *
2396                 EXT2_BLOCKS_PER_GROUP(fs->super);
2397         groups = ext2fs_div64_ceil(blks_needed,
2398                                    EXT2_BLOCKS_PER_GROUP(fs->super));
2399 #ifdef RESIZE2FS_DEBUG
2400         if (flags & RESIZE_DEBUG_MIN_CALC)
2401                 printf("fs has %d inodes, %d groups required.\n",
2402                        inode_count, groups);
2403 #endif
2404
2405         /*
2406          * number of old-style block group descriptor blocks
2407          */
2408         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
2409                 old_desc_blocks = fs->super->s_first_meta_bg;
2410         else
2411                 old_desc_blocks = fs->desc_blocks +
2412                         fs->super->s_reserved_gdt_blocks;
2413
2414         /* calculate how many blocks are needed for data */
2415         data_needed = ext2fs_blocks_count(fs->super) -
2416                 ext2fs_free_blocks_count(fs->super);
2417
2418         for (grp = 0; grp < fs->group_desc_count; grp++)
2419                 data_needed -= calc_group_overhead(fs, grp, old_desc_blocks);
2420 #ifdef RESIZE2FS_DEBUG
2421         if (flags & RESIZE_DEBUG_MIN_CALC)
2422                 printf("fs requires %llu data blocks.\n", data_needed);
2423 #endif
2424
2425         /*
2426          * For ext4 we need to allow for up to a flex_bg worth of
2427          * inode tables of slack space so the resize operation can be
2428          * guaranteed to finish.
2429          */
2430         if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_FLEX_BG) {
2431                 extra_groups = flexbg_size - (groups & (flexbg_size - 1));
2432                 data_needed += fs->inode_blocks_per_group * extra_groups;
2433                 extra_groups = groups % flexbg_size;
2434         }
2435
2436         /*
2437          * figure out how many data blocks we have given the number of groups
2438          * we need for our inodes
2439          */
2440         data_blocks = groups * EXT2_BLOCKS_PER_GROUP(fs->super);
2441         last_start = 0;
2442         for (grp = 0; grp < groups; grp++) {
2443                 overhead = calc_group_overhead(fs, grp, old_desc_blocks);
2444
2445                 /*
2446                  * we want to keep track of how much data we can store in
2447                  * the groups leading up to the last group so we can determine
2448                  * how big the last group needs to be
2449                  */
2450                 if (grp != (groups - 1))
2451                         last_start += EXT2_BLOCKS_PER_GROUP(fs->super) -
2452                                 overhead;
2453
2454                 data_blocks -= overhead;
2455         }
2456 #ifdef RESIZE2FS_DEBUG
2457         if (flags & RESIZE_DEBUG_MIN_CALC)
2458                 printf("With %d group(s), we have %llu blocks available.\n",
2459                        groups, data_blocks);
2460 #endif
2461
2462         /*
2463          * if we need more group descriptors in order to accomodate our data
2464          * then we need to add them here
2465          */
2466         while (data_needed > data_blocks) {
2467                 blk64_t remainder = data_needed - data_blocks;
2468                 dgrp_t extra_grps;
2469
2470                 /* figure out how many more groups we need for the data */
2471                 extra_grps = ext2fs_div64_ceil(remainder,
2472                                                EXT2_BLOCKS_PER_GROUP(fs->super));
2473
2474                 data_blocks += extra_grps * EXT2_BLOCKS_PER_GROUP(fs->super);
2475
2476                 /* ok we have to account for the last group */
2477                 overhead = calc_group_overhead(fs, groups-1, old_desc_blocks);
2478                 last_start += EXT2_BLOCKS_PER_GROUP(fs->super) - overhead;
2479
2480                 for (grp = groups; grp < groups+extra_grps; grp++) {
2481                         overhead = calc_group_overhead(fs, grp,
2482                                                        old_desc_blocks);
2483
2484                         /*
2485                          * again, we need to see how much data we cram into
2486                          * all of the groups leading up to the last group
2487                          */
2488                         if (grp != (groups + extra_grps - 1))
2489                                 last_start += EXT2_BLOCKS_PER_GROUP(fs->super)
2490                                         - overhead;
2491
2492                         data_blocks -= overhead;
2493                 }
2494
2495                 groups += extra_grps;
2496                 extra_groups += extra_grps;
2497                 if (fs->super->s_feature_incompat
2498                         & EXT4_FEATURE_INCOMPAT_FLEX_BG
2499                     && extra_groups > flexbg_size) {
2500                         /*
2501                          * For ext4 we need to allow for up to a flex_bg worth
2502                          * of inode tables of slack space so the resize
2503                          * operation can be guaranteed to finish.
2504                          */
2505                         extra_groups = flexbg_size -
2506                                                 (groups & (flexbg_size - 1));
2507                         data_needed += (fs->inode_blocks_per_group *
2508                                         extra_groups);
2509                         extra_groups = groups % flexbg_size;
2510                 }
2511 #ifdef RESIZE2FS_DEBUG
2512                 if (flags & RESIZE_DEBUG_MIN_CALC)
2513                         printf("Added %d extra group(s), "
2514                                "data_needed %llu, data_blocks %llu, "
2515                                "last_start %llu\n",
2516                                extra_grps, data_needed, data_blocks,
2517                                last_start);
2518 #endif
2519         }
2520
2521         /* now for the fun voodoo */
2522         overhead = calc_group_overhead(fs, groups-1, old_desc_blocks);
2523 #ifdef RESIZE2FS_DEBUG
2524         if (flags & RESIZE_DEBUG_MIN_CALC)
2525                 printf("Last group's overhead is %llu\n", overhead);
2526 #endif
2527
2528         /*
2529          * if this is the case then the last group is going to have data in it
2530          * so we need to adjust the size of the last group accordingly
2531          */
2532         if (last_start < data_needed) {
2533                 blk64_t remainder = data_needed - last_start;
2534
2535 #ifdef RESIZE2FS_DEBUG
2536                 if (flags & RESIZE_DEBUG_MIN_CALC)
2537                         printf("Need %llu data blocks in last group\n",
2538                                remainder);
2539 #endif
2540                 /*
2541                  * 50 is a magic number that mkfs/resize uses to see if its
2542                  * even worth making/resizing the fs.  basically you need to
2543                  * have at least 50 blocks in addition to the blocks needed
2544                  * for the metadata in the last group
2545                  */
2546                 if (remainder > 50)
2547                         overhead += remainder;
2548                 else
2549                         overhead += 50;
2550         } else
2551                 overhead += 50;
2552
2553         overhead += fs->super->s_first_data_block;
2554 #ifdef RESIZE2FS_DEBUG
2555         if (flags & RESIZE_DEBUG_MIN_CALC)
2556                 printf("Final size of last group is %lld\n", overhead);
2557 #endif
2558
2559         /*
2560          * since our last group doesn't have to be BLOCKS_PER_GROUP large, we
2561          * only do groups-1, and then add the number of blocks needed to
2562          * handle the group descriptor metadata+data that we need
2563          */
2564         blks_needed = (groups-1) * EXT2_BLOCKS_PER_GROUP(fs->super);
2565         blks_needed += overhead;
2566
2567         /*
2568          * Make sure blks_needed covers the end of the inode table in
2569          * the last block group.
2570          */
2571         overhead = ext2fs_inode_table_loc(fs, groups-1) +
2572                 fs->inode_blocks_per_group;
2573         if (blks_needed < overhead)
2574                 blks_needed = overhead;
2575
2576 #ifdef RESIZE2FS_DEBUG
2577         if (flags & RESIZE_DEBUG_MIN_CALC)
2578                 printf("Estimated blocks needed: %llu\n", blks_needed);
2579 #endif
2580
2581         /*
2582          * If at this point we've already added up more "needed" than
2583          * the current size, just return current size as minimum.
2584          */
2585         if (blks_needed >= ext2fs_blocks_count(fs->super))
2586                 return ext2fs_blocks_count(fs->super);
2587         /*
2588          * We need to reserve a few extra blocks if extents are
2589          * enabled, in case we need to grow the extent tree.  The more
2590          * we shrink the file system, the more space we need.
2591          */
2592         if (fs->super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_EXTENTS) {
2593                 blk64_t safe_margin = (ext2fs_blocks_count(fs->super) -
2594                                        blks_needed)/500;
2595 #ifdef RESIZE2FS_DEBUG
2596                 if (flags & RESIZE_DEBUG_MIN_CALC)
2597                         printf("Extents safety margin: %llu\n", safe_margin);
2598 #endif
2599                 blks_needed += safe_margin;
2600         }
2601
2602         return blks_needed;
2603 }