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_free(&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 = EXT2_GROUPS_TO_BLOCKS(fs->super, fs->group_desc_count) - 1 +
 439                 fs->super->s_first_data_block;
 440         retval = ext2fs_resize_block_bitmap2(new_size - 1,
 441                                              real_end, fs->block_map);
 442         if (retval) goto errout;
 443
 444         /*
 445          * If we are growing the file system, also grow the size of
 446          * the reserve_blocks bitmap
 447          */
 448         if (reserve_blocks && new_size > ext2fs_blocks_count(old_fs->super)) {
 449                 retval = ext2fs_resize_block_bitmap2(new_size - 1,
 450                                                      real_end, reserve_blocks);
 451                 if (retval) goto errout;
 452         }
 453
 454         /*
 455          * Reallocate the group descriptors as necessary.
 456          */
 457         if (old_fs->desc_blocks != fs->desc_blocks) {
 458                 retval = ext2fs_resize_mem(old_fs->desc_blocks *
 459                                            fs->blocksize,
 460                                            fs->desc_blocks * fs->blocksize,
 461                                            &fs->group_desc);
 462                 if (retval)
 463                         goto errout;
 464                 if (fs->desc_blocks > old_fs->desc_blocks)
 465                         memset((char *) fs->group_desc +
 466                                (old_fs->desc_blocks * fs->blocksize), 0,
 467                                (fs->desc_blocks - old_fs->desc_blocks) *
 468                                fs->blocksize);
 469         }
 470
 471         /*
 472          * If the resize_inode feature is set, and we are changing the
 473          * number of descriptor blocks, then adjust
 474          * s_reserved_gdt_blocks if possible to avoid needing to move
 475          * the inode table either now or in the future.
 476          */
 477         if ((fs->super->s_feature_compat &
 478              EXT2_FEATURE_COMPAT_RESIZE_INODE) &&
 479             (old_fs->desc_blocks != fs->desc_blocks)) {
 480                 int new;
 481
 482                 new = ((int) fs->super->s_reserved_gdt_blocks) +
 483                         (old_fs->desc_blocks - fs->desc_blocks);
 484                 if (new < 0)
 485                         new = 0;
 486                 if (new > (int) fs->blocksize/4)
 487                         new = fs->blocksize/4;
 488                 fs->super->s_reserved_gdt_blocks = new;
 489         }
 490
 491         if ((fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) &&
 492             (fs->super->s_first_meta_bg > fs->desc_blocks)) {
 493                 fs->super->s_feature_incompat &=
 494                         ~EXT2_FEATURE_INCOMPAT_META_BG;
 495                 fs->super->s_first_meta_bg = 0;
 496         }
 497
 498         /*
 499          * Update the location of the backup superblocks if the
 500          * sparse_super2 feature is enabled.
 501          */
 502         if (fs->super->s_feature_compat & EXT4_FEATURE_COMPAT_SPARSE_SUPER2) {
 503                 dgrp_t last_bg = fs->group_desc_count - 1;
 504                 dgrp_t old_last_bg = old_fs->group_desc_count - 1;
 505
 506                 if (last_bg > old_last_bg) {
 507                         if (old_fs->group_desc_count == 1)
 508                                 fs->super->s_backup_bgs[0] = 1;
 509                         if (old_fs->group_desc_count == 1 &&
 510                             fs->super->s_backup_bgs[0])
 511                                 fs->super->s_backup_bgs[0] = last_bg;
 512                         else if (fs->super->s_backup_bgs[1])
 513                                 fs->super->s_backup_bgs[1] = last_bg;
 514                 } else if (last_bg < old_last_bg) {
 515                         if (fs->super->s_backup_bgs[0] > last_bg)
 516                                 fs->super->s_backup_bgs[0] = 0;
 517                         if (fs->super->s_backup_bgs[1] > last_bg)
 518                                 fs->super->s_backup_bgs[1] = 0;
 519                         if (last_bg > 1 &&
 520                             old_fs->super->s_backup_bgs[1] == old_last_bg)
 521                                 fs->super->s_backup_bgs[1] = last_bg;
 522                 }
 523         }
 524
 525         /*
 526          * If we are shrinking the number of block groups, we're done
 527          * and can exit now.
 528          */
 529         if (old_fs->group_desc_count > fs->group_desc_count) {
 530                 /*
 531                  * Check the block groups that we are chopping off
 532                  * and free any blocks associated with their metadata
 533                  */
 534                 retval = free_gdp_blocks(fs, reserve_blocks, old_fs,
 535                                          fs->group_desc_count);
 536                 goto errout;
 537         }
 538
 539         /*
 540          * Fix the count of the last (old) block group
 541          */
 542         old_numblocks = (ext2fs_blocks_count(old_fs->super) -
 543                          old_fs->super->s_first_data_block) %
 544                                  old_fs->super->s_blocks_per_group;
 545         if (!old_numblocks)
 546                 old_numblocks = old_fs->super->s_blocks_per_group;
 547         if (old_fs->group_desc_count == fs->group_desc_count) {
 548                 numblocks = (ext2fs_blocks_count(fs->super) -
 549                              fs->super->s_first_data_block) %
 550                         fs->super->s_blocks_per_group;
 551                 if (!numblocks)
 552                         numblocks = fs->super->s_blocks_per_group;
 553         } else
 554                 numblocks = fs->super->s_blocks_per_group;
 555         i = old_fs->group_desc_count - 1;
 556         ext2fs_bg_free_blocks_count_set(fs, i, ext2fs_bg_free_blocks_count(fs, i) + (numblocks - old_numblocks));
 557         ext2fs_group_desc_csum_set(fs, i);
 558
 559         /*
 560          * If the number of block groups is staying the same, we're
 561          * done and can exit now.  (If the number block groups is
 562          * shrinking, we had exited earlier.)
 563          */
 564         if (old_fs->group_desc_count >= fs->group_desc_count) {
 565                 retval = 0;
 566                 goto errout;
 567         }
 568
 569         /*
 570          * Initialize the new block group descriptors
 571          */
 572         group_block = ext2fs_group_first_block2(fs,
 573                                                 old_fs->group_desc_count);
 574         csum_flag = ext2fs_has_group_desc_csum(fs);
 575         if (access("/sys/fs/ext4/features/lazy_itable_init", F_OK) == 0)
 576                 lazy_itable_init = 1;
 577         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
 578                 old_desc_blocks = fs->super->s_first_meta_bg;
 579         else
 580                 old_desc_blocks = fs->desc_blocks +
 581                         fs->super->s_reserved_gdt_blocks;
 582
 583         /*
 584          * If we changed the number of block_group descriptor blocks,
 585          * we need to make sure they are all marked as reserved in the
 586          * file systems's block allocation map.
 587          */
 588         for (i = 0; i < old_fs->group_desc_count; i++)
 589                 ext2fs_reserve_super_and_bgd(fs, i, fs->block_map);
 590
 591         for (i = old_fs->group_desc_count;
 592              i < fs->group_desc_count; i++) {
 593                 memset(ext2fs_group_desc(fs, fs->group_desc, i), 0,
 594                        sizeof(struct ext2_group_desc));
 595                 adjblocks = 0;
 596
 597                 ext2fs_bg_flags_zap(fs, i);
 598                 if (csum_flag) {
 599                         ext2fs_bg_flags_set(fs, i, EXT2_BG_INODE_UNINIT);
 600                         if (!lazy_itable_init)
 601                                 ext2fs_bg_flags_set(fs, i,
 602                                                     EXT2_BG_INODE_ZEROED);
 603                         ext2fs_bg_itable_unused_set(fs, i,
 604                                         fs->super->s_inodes_per_group);
 605                 }
 606
 607                 numblocks = ext2fs_group_blocks_count(fs, i);
 608                 if ((i < fs->group_desc_count - 1) && csum_flag)
 609                         ext2fs_bg_flags_set(fs, i, EXT2_BG_BLOCK_UNINIT);
 610
 611                 has_super = ext2fs_bg_has_super(fs, i);
 612                 if (has_super) {
 613                         ext2fs_block_alloc_stats2(fs, group_block, +1);
 614                         adjblocks++;
 615                 }
 616                 meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
 617                 meta_bg = i / meta_bg_size;
 618                 if (!(fs->super->s_feature_incompat &
 619                       EXT2_FEATURE_INCOMPAT_META_BG) ||
 620                     (meta_bg < fs->super->s_first_meta_bg)) {
 621                         if (has_super) {
 622                                 for (j=0; j < old_desc_blocks; j++)
 623                                         ext2fs_block_alloc_stats2(fs,
 624                                                  group_block + 1 + j, +1);
 625                                 adjblocks += old_desc_blocks;
 626                         }
 627                 } else {
 628                         if (has_super)
 629                                 has_super = 1;
 630                         if (((i % meta_bg_size) == 0) ||
 631                             ((i % meta_bg_size) == 1) ||
 632                             ((i % meta_bg_size) == (meta_bg_size-1)))
 633                                 ext2fs_block_alloc_stats2(fs,
 634                                                  group_block + has_super, +1);
 635                 }
 636
 637                 adjblocks += 2 + fs->inode_blocks_per_group;
 638
 639                 numblocks -= adjblocks;
 640                 ext2fs_free_blocks_count_set(fs->super,
 641                              ext2fs_free_blocks_count(fs->super) - adjblocks);
 642                 fs->super->s_free_inodes_count +=
 643                         fs->super->s_inodes_per_group;
 644                 ext2fs_bg_free_blocks_count_set(fs, i, numblocks);
 645                 ext2fs_bg_free_inodes_count_set(fs, i,
 646                                                 fs->super->s_inodes_per_group);
 647                 ext2fs_bg_used_dirs_count_set(fs, i, 0);
 648                 ext2fs_group_desc_csum_set(fs, i);
 649
 650                 retval = ext2fs_allocate_group_table(fs, i, 0);
 651                 if (retval) goto errout;
 652
 653                 group_block += fs->super->s_blocks_per_group;
 654         }
 655         retval = 0;
 656
 657         /*
 658          * Mark all of the metadata blocks as reserved so they won't
 659          * get allocated by the call to ext2fs_allocate_group_table()
 660          * in blocks_to_move(), where we allocate new blocks to
 661          * replace those allocation bitmap and inode table blocks
 662          * which have to get relocated to make space for an increased
 663          * number of the block group descriptors.
 664          */
 665         if (reserve_blocks)
 666                 mark_table_blocks(fs, reserve_blocks);
 667
 668 errout:
 669         return (retval);
 670 }
 671
 672 /*
 673  * This routine adjusts the superblock and other data structures, both
 674  * in disk as well as in memory...
 675  */
 676 static errcode_t adjust_superblock(ext2_resize_t rfs, blk64_t new_size)
 677 {
 678         ext2_filsys     fs = rfs->new_fs;
 679         int             adj = 0;
 680         errcode_t       retval;
 681         blk64_t         group_block;
 682         unsigned long   i;
 683         unsigned long   max_group;
 684
 685         ext2fs_mark_super_dirty(fs);
 686         ext2fs_mark_bb_dirty(fs);
 687         ext2fs_mark_ib_dirty(fs);
 688
 689         retval = ext2fs_allocate_block_bitmap(fs, _("reserved blocks"),
 690                                               &rfs->reserve_blocks);
 691         if (retval)
 692                 return retval;
 693
 694         retval = adjust_fs_info(fs, rfs->old_fs, rfs->reserve_blocks, new_size);
 695         if (retval)
 696                 goto errout;
 697
 698         /*
 699          * Check to make sure there are enough inodes
 700          */
 701         if ((rfs->old_fs->super->s_inodes_count -
 702              rfs->old_fs->super->s_free_inodes_count) >
 703             rfs->new_fs->super->s_inodes_count) {
 704                 retval = ENOSPC;
 705                 goto errout;
 706         }
 707
 708         /*
 709          * If we are shrinking the number block groups, we're done and
 710          * can exit now.
 711          */
 712         if (rfs->old_fs->group_desc_count > fs->group_desc_count) {
 713                 retval = 0;
 714                 goto errout;
 715         }
 716
 717         /*
 718          * If the number of block groups is staying the same, we're
 719          * done and can exit now.  (If the number block groups is
 720          * shrinking, we had exited earlier.)
 721          */
 722         if (rfs->old_fs->group_desc_count >= fs->group_desc_count) {
 723                 retval = 0;
 724                 goto errout;
 725         }
 726
 727         /*
 728          * If we are using uninit_bg (aka GDT_CSUM) and the kernel
 729          * supports lazy inode initialization, we can skip
 730          * initializing the inode table.
 731          */
 732         if (lazy_itable_init && ext2fs_has_group_desc_csum(fs)) {
 733                 retval = 0;
 734                 goto errout;
 735         }
 736
 737         /*
 738          * Initialize the inode table
 739          */
 740         retval = ext2fs_get_array(fs->blocksize, fs->inode_blocks_per_group,
 741                                 &rfs->itable_buf);
 742         if (retval)
 743                 goto errout;
 744
 745         memset(rfs->itable_buf, 0, fs->blocksize * fs->inode_blocks_per_group);
 746         group_block = ext2fs_group_first_block2(fs,
 747                                                 rfs->old_fs->group_desc_count);
 748         adj = rfs->old_fs->group_desc_count;
 749         max_group = fs->group_desc_count - adj;
 750         if (rfs->progress) {
 751                 retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
 752                                        0, max_group);
 753                 if (retval)
 754                         goto errout;
 755         }
 756         for (i = rfs->old_fs->group_desc_count;
 757              i < fs->group_desc_count; i++) {
 758                 /*
 759                  * Write out the new inode table
 760                  */
 761                 retval = io_channel_write_blk64(fs->io,
 762                                                 ext2fs_inode_table_loc(fs, i),
 763                                                 fs->inode_blocks_per_group,
 764                                                 rfs->itable_buf);
 765                 if (retval) goto errout;
 766
 767                 io_channel_flush(fs->io);
 768                 if (rfs->progress) {
 769                         retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
 770                                                i - adj + 1, max_group);
 771                         if (retval)
 772                                 goto errout;
 773                 }
 774                 group_block += fs->super->s_blocks_per_group;
 775         }
 776         io_channel_flush(fs->io);
 777         retval = 0;
 778
 779 errout:
 780         return retval;
 781 }
 782
 783 /* --------------------------------------------------------------------
 784  *
 785  * Resize processing, phase 2.
 786  *
 787  * In this phase we adjust determine which blocks need to be moved, in
 788  * blocks_to_move().  We then copy the blocks to their ultimate new
 789  * destinations using block_mover().  Since we are copying blocks to
 790  * their new locations, again during this pass we can abort without
 791  * any problems.
 792  * --------------------------------------------------------------------
 793  */
 794
 795 /*
 796  * This helper function creates a block bitmap with all of the
 797  * filesystem meta-data blocks.
 798  */
 799 static errcode_t mark_table_blocks(ext2_filsys fs,
 800                                    ext2fs_block_bitmap bmap)
 801 {
 802         dgrp_t                  i;
 803         blk64_t                 blk;
 804
 805         for (i = 0; i < fs->group_desc_count; i++) {
 806                 ext2fs_reserve_super_and_bgd(fs, i, bmap);
 807
 808                 /*
 809                  * Mark the blocks used for the inode table
 810                  */
 811                 blk = ext2fs_inode_table_loc(fs, i);
 812                 if (blk)
 813                         ext2fs_mark_block_bitmap_range2(bmap, blk,
 814                                                 fs->inode_blocks_per_group);
 815
 816                 /*
 817                  * Mark block used for the block bitmap
 818                  */
 819                 blk = ext2fs_block_bitmap_loc(fs, i);
 820                 if (blk)
 821                         ext2fs_mark_block_bitmap2(bmap, blk);
 822
 823                 /*
 824                  * Mark block used for the inode bitmap
 825                  */
 826                 blk = ext2fs_inode_bitmap_loc(fs, i);
 827                 if (blk)
 828                         ext2fs_mark_block_bitmap2(bmap, blk);
 829         }
 830         return 0;
 831 }
 832
 833 /*
 834  * This function checks to see if a particular block (either a
 835  * superblock or a block group descriptor) overlaps with an inode or
 836  * block bitmap block, or with the inode table.
 837  */
 838 static void mark_fs_metablock(ext2_resize_t rfs,
 839                               ext2fs_block_bitmap meta_bmap,
 840                               int group, blk64_t blk)
 841 {
 842         ext2_filsys     fs = rfs->new_fs;
 843
 844         ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
 845         ext2fs_block_alloc_stats2(fs, blk, +1);
 846
 847         /*
 848          * Check to see if we overlap with the inode or block bitmap,
 849          * or the inode tables.  If not, and the block is in use, then
 850          * mark it as a block to be moved.
 851          */
 852         if (IS_BLOCK_BM(fs, group, blk)) {
 853                 ext2fs_block_bitmap_loc_set(fs, group, 0);
 854                 rfs->needed_blocks++;
 855                 return;
 856         }
 857         if (IS_INODE_BM(fs, group, blk)) {
 858                 ext2fs_inode_bitmap_loc_set(fs, group, 0);
 859                 rfs->needed_blocks++;
 860                 return;
 861         }
 862         if (IS_INODE_TB(fs, group, blk)) {
 863                 ext2fs_inode_table_loc_set(fs, group, 0);
 864                 rfs->needed_blocks++;
 865                 return;
 866         }
 867         if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_FLEX_BG) {
 868                 dgrp_t i;
 869
 870                 for (i=0; i < rfs->old_fs->group_desc_count; i++) {
 871                         if (IS_BLOCK_BM(fs, i, blk)) {
 872                                 ext2fs_block_bitmap_loc_set(fs, i, 0);
 873                                 rfs->needed_blocks++;
 874                                 return;
 875                         }
 876                         if (IS_INODE_BM(fs, i, blk)) {
 877                                 ext2fs_inode_bitmap_loc_set(fs, i, 0);
 878                                 rfs->needed_blocks++;
 879                                 return;
 880                         }
 881                         if (IS_INODE_TB(fs, i, blk)) {
 882                                 ext2fs_inode_table_loc_set(fs, i, 0);
 883                                 rfs->needed_blocks++;
 884                                 return;
 885                         }
 886                 }
 887         }
 888
 889         if (ext2fs_has_group_desc_csum(fs) &&
 890             (ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT))) {
 891                 /*
 892                  * If the block bitmap is uninitialized, which means
 893                  * nothing other than standard metadata in use.
 894                  */
 895                 return;
 896         } else if (ext2fs_test_block_bitmap2(rfs->old_fs->block_map, blk) &&
 897                    !ext2fs_test_block_bitmap2(meta_bmap, blk)) {
 898                 ext2fs_mark_block_bitmap2(rfs->move_blocks, blk);
 899                 rfs->needed_blocks++;
 900         }
 901 }
 902
 903
 904 /*
 905  * This routine marks and unmarks reserved blocks in the new block
 906  * bitmap.  It also determines which blocks need to be moved and
 907  * places this information into the move_blocks bitmap.
 908  */
 909 static errcode_t blocks_to_move(ext2_resize_t rfs)
 910 {
 911         int             j, has_super;
 912         dgrp_t          i, max_groups, g;
 913         blk64_t         blk, group_blk;
 914         blk64_t         old_blocks, new_blocks, group_end, cluster_freed;
 915         blk64_t         new_size;
 916         unsigned int    meta_bg, meta_bg_size;
 917         errcode_t       retval;
 918         ext2_filsys     fs, old_fs;
 919         ext2fs_block_bitmap     meta_bmap, new_meta_bmap = NULL;
 920         int             flex_bg;
 921
 922         fs = rfs->new_fs;
 923         old_fs = rfs->old_fs;
 924         if (ext2fs_blocks_count(old_fs->super) > ext2fs_blocks_count(fs->super))
 925                 fs = rfs->old_fs;
 926
 927         retval = ext2fs_allocate_block_bitmap(fs, _("blocks to be moved"),
 928                                               &rfs->move_blocks);
 929         if (retval)
 930                 return retval;
 931
 932         retval = ext2fs_allocate_block_bitmap(fs, _("meta-data blocks"),
 933                                               &meta_bmap);
 934         if (retval)
 935                 return retval;
 936
 937         retval = mark_table_blocks(old_fs, meta_bmap);
 938         if (retval)
 939                 return retval;
 940
 941         fs = rfs->new_fs;
 942
 943         /*
 944          * If we're shrinking the filesystem, we need to move any
 945          * group's metadata blocks (either allocation bitmaps or the
 946          * inode table) which are beyond the end of the new
 947          * filesystem.
 948          */
 949         new_size = ext2fs_blocks_count(fs->super);
 950         if (new_size < ext2fs_blocks_count(old_fs->super)) {
 951                 for (g = 0; g < fs->group_desc_count; g++) {
 952                         int realloc = 0;
 953                         /*
 954                          * ext2fs_allocate_group_table will re-allocate any
 955                          * metadata blocks whose location is set to zero.
 956                          */
 957                         if (ext2fs_block_bitmap_loc(fs, g) >= new_size) {
 958                                 ext2fs_block_bitmap_loc_set(fs, g, 0);
 959                                 realloc = 1;
 960                         }
 961                         if (ext2fs_inode_bitmap_loc(fs, g) >= new_size) {
 962                                 ext2fs_inode_bitmap_loc_set(fs, g, 0);
 963                                 realloc = 1;
 964                         }
 965                         if ((ext2fs_inode_table_loc(fs, g) +
 966                              fs->inode_blocks_per_group) > new_size) {
 967                                 ext2fs_inode_table_loc_set(fs, g, 0);
 968                                 realloc = 1;
 969                         }
 970
 971                         if (realloc) {
 972                                 retval = ext2fs_allocate_group_table(fs, g, 0);
 973                                 if (retval)
 974                                         return retval;
 975                         }
 976                 }
 977         }
 978
 979         /*
 980          * If we're shrinking the filesystem, we need to move all of
 981          * the blocks that don't fit any more
 982          */
 983         for (blk = ext2fs_blocks_count(fs->super);
 984              blk < ext2fs_blocks_count(old_fs->super); blk++) {
 985                 g = ext2fs_group_of_blk2(fs, blk);
 986                 if (ext2fs_has_group_desc_csum(fs) &&
 987                     ext2fs_bg_flags_test(old_fs, g, EXT2_BG_BLOCK_UNINIT)) {
 988                         /*
 989                          * The block bitmap is uninitialized, so skip
 990                          * to the next block group.
 991                          */
 992                         blk = ext2fs_group_first_block2(fs, g+1) - 1;
 993                         continue;
 994                 }
 995                 if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
 996                     !ext2fs_test_block_bitmap2(meta_bmap, blk)) {
 997                         ext2fs_mark_block_bitmap2(rfs->move_blocks, blk);
 998                         rfs->needed_blocks++;
 999                 }
1000                 ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
1001         }
1002
1003         if (old_fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
1004                 old_blocks = old_fs->super->s_first_meta_bg;
1005         else
1006                 old_blocks = old_fs->desc_blocks +
1007                         old_fs->super->s_reserved_gdt_blocks;
1008         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
1009                 new_blocks = fs->super->s_first_meta_bg;
1010         else
1011                 new_blocks = fs->desc_blocks + fs->super->s_reserved_gdt_blocks;
1012
1013         retval = reserve_sparse_super2_last_group(rfs, meta_bmap);
1014         if (retval)
1015                 goto errout;
1016
1017         if (old_blocks == new_blocks) {
1018                 retval = 0;
1019                 goto errout;
1020         }
1021
1022         max_groups = fs->group_desc_count;
1023         if (max_groups > old_fs->group_desc_count)
1024                 max_groups = old_fs->group_desc_count;
1025         group_blk = old_fs->super->s_first_data_block;
1026         /*
1027          * If we're reducing the number of descriptor blocks, this
1028          * makes life easy.  :-)   We just have to mark some extra
1029          * blocks as free.
1030          */
1031         if (old_blocks > new_blocks) {
1032                 if (EXT2FS_CLUSTER_RATIO(fs) > 1) {
1033                         retval = ext2fs_allocate_block_bitmap(fs,
1034                                                         _("new meta blocks"),
1035                                                         &new_meta_bmap);
1036                         if (retval)
1037                                 goto errout;
1038
1039                         retval = mark_table_blocks(fs, new_meta_bmap);
1040                         if (retval)
1041                                 goto errout;
1042                 }
1043
1044                 for (i = 0; i < max_groups; i++) {
1045                         if (!ext2fs_bg_has_super(fs, i)) {
1046                                 group_blk += fs->super->s_blocks_per_group;
1047                                 continue;
1048                         }
1049                         group_end = group_blk + 1 + old_blocks;
1050                         for (blk = group_blk + 1 + new_blocks;
1051                              blk < group_end;) {
1052                                 if (new_meta_bmap == NULL ||
1053                                     !ext2fs_test_block_bitmap2(new_meta_bmap,
1054                                                                blk)) {
1055                                         cluster_freed =
1056                                                 EXT2FS_CLUSTER_RATIO(fs) -
1057                                                 (blk &
1058                                                  EXT2FS_CLUSTER_MASK(fs));
1059                                         if (cluster_freed > group_end - blk)
1060                                                 cluster_freed = group_end - blk;
1061                                         ext2fs_block_alloc_stats2(fs, blk, -1);
1062                                         blk += EXT2FS_CLUSTER_RATIO(fs);
1063                                         rfs->needed_blocks -= cluster_freed;
1064                                         continue;
1065                                 }
1066                                 rfs->needed_blocks--;
1067                                 blk++;
1068                         }
1069                         group_blk += fs->super->s_blocks_per_group;
1070                 }
1071                 retval = 0;
1072                 goto errout;
1073         }
1074         /*
1075          * If we're increasing the number of descriptor blocks, life
1076          * gets interesting....
1077          */
1078         meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
1079         flex_bg = fs->super->s_feature_incompat &
1080                 EXT4_FEATURE_INCOMPAT_FLEX_BG;
1081         /* first reserve all of the existing fs meta blocks */
1082         for (i = 0; i < max_groups; i++) {
1083                 has_super = ext2fs_bg_has_super(fs, i);
1084                 if (has_super)
1085                         mark_fs_metablock(rfs, meta_bmap, i, group_blk);
1086
1087                 meta_bg = i / meta_bg_size;
1088                 if (!(fs->super->s_feature_incompat &
1089                       EXT2_FEATURE_INCOMPAT_META_BG) ||
1090                     (meta_bg < fs->super->s_first_meta_bg)) {
1091                         if (has_super) {
1092                                 for (blk = group_blk+1;
1093                                      blk < group_blk + 1 + new_blocks; blk++)
1094                                         mark_fs_metablock(rfs, meta_bmap,
1095                                                           i, blk);
1096                         }
1097                 } else {
1098                         if (has_super)
1099                                 has_super = 1;
1100                         if (((i % meta_bg_size) == 0) ||
1101                             ((i % meta_bg_size) == 1) ||
1102                             ((i % meta_bg_size) == (meta_bg_size-1)))
1103                                 mark_fs_metablock(rfs, meta_bmap, i,
1104                                                   group_blk + has_super);
1105                 }
1106
1107                 /*
1108                  * Reserve the existing meta blocks that we know
1109                  * aren't to be moved.
1110                  *
1111                  * For flex_bg file systems, in order to avoid
1112                  * overwriting fs metadata (especially inode table
1113                  * blocks) belonging to a different block group when
1114                  * we are relocating the inode tables, we need to
1115                  * reserve all existing fs metadata blocks.
1116                  */
1117                 if (ext2fs_block_bitmap_loc(fs, i))
1118                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
1119                                  ext2fs_block_bitmap_loc(fs, i));
1120                 else if (flex_bg && i < old_fs->group_desc_count)
1121                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
1122                                  ext2fs_block_bitmap_loc(old_fs, i));
1123
1124                 if (ext2fs_inode_bitmap_loc(fs, i))
1125                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
1126                                  ext2fs_inode_bitmap_loc(fs, i));
1127                 else if (flex_bg && i < old_fs->group_desc_count)
1128                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
1129                                  ext2fs_inode_bitmap_loc(old_fs, i));
1130
1131                 if (ext2fs_inode_table_loc(fs, i))
1132                         ext2fs_mark_block_bitmap_range2(rfs->reserve_blocks,
1133                                         ext2fs_inode_table_loc(fs, i),
1134                                         fs->inode_blocks_per_group);
1135                 else if (flex_bg && i < old_fs->group_desc_count)
1136                         ext2fs_mark_block_bitmap_range2(rfs->reserve_blocks,
1137                                         ext2fs_inode_table_loc(old_fs, i),
1138                                         old_fs->inode_blocks_per_group);
1139
1140                 group_blk += rfs->new_fs->super->s_blocks_per_group;
1141         }
1142
1143         /* Allocate the missing data structures */
1144         for (i = 0; i < max_groups; i++) {
1145                 if (ext2fs_inode_table_loc(fs, i) &&
1146                     ext2fs_inode_bitmap_loc(fs, i) &&
1147                     ext2fs_block_bitmap_loc(fs, i))
1148                         continue;
1149
1150                 retval = ext2fs_allocate_group_table(fs, i,
1151                                                      rfs->reserve_blocks);
1152                 if (retval)
1153                         goto errout;
1154
1155                 /*
1156                  * For those structures that have changed, we need to
1157                  * do bookkeepping.
1158                  */
1159                 if (ext2fs_block_bitmap_loc(old_fs, i) !=
1160                     (blk = ext2fs_block_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                 if (ext2fs_inode_bitmap_loc(old_fs, i) !=
1168                     (blk = ext2fs_inode_bitmap_loc(fs, i))) {
1169                         ext2fs_block_alloc_stats2(fs, blk, +1);
1170                         if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
1171                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
1172                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
1173                                                          blk);
1174                 }
1175
1176                 /*
1177                  * The inode table, if we need to relocate it, is
1178                  * handled specially.  We have to reserve the blocks
1179                  * for both the old and the new inode table, since we
1180                  * can't have the inode table be destroyed during the
1181                  * block relocation phase.
1182                  */
1183                 if (ext2fs_inode_table_loc(fs, i) == ext2fs_inode_table_loc(old_fs, i))
1184                         continue;       /* inode table not moved */
1185
1186                 rfs->needed_blocks += fs->inode_blocks_per_group;
1187
1188                 /*
1189                  * Mark the new inode table as in use in the new block
1190                  * allocation bitmap, and move any blocks that might
1191                  * be necessary.
1192                  */
1193                 for (blk = ext2fs_inode_table_loc(fs, i), j=0;
1194                      j < fs->inode_blocks_per_group ; j++, blk++) {
1195                         ext2fs_block_alloc_stats2(fs, blk, +1);
1196                         if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
1197                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
1198                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
1199                                                          blk);
1200                 }
1201
1202                 /*
1203                  * Make sure the old inode table is reserved in the
1204                  * block reservation bitmap.
1205                  */
1206                 for (blk = ext2fs_inode_table_loc(rfs->old_fs, i), j=0;
1207                      j < fs->inode_blocks_per_group ; j++, blk++)
1208                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
1209         }
1210         retval = 0;
1211
1212 errout:
1213         if (new_meta_bmap)
1214                 ext2fs_free_block_bitmap(new_meta_bmap);
1215         if (meta_bmap)
1216                 ext2fs_free_block_bitmap(meta_bmap);
1217
1218         return retval;
1219 }
1220
1221 /*
1222  * This helper function tries to allocate a new block.  We try to
1223  * avoid hitting the original group descriptor blocks at least at
1224  * first, since we want to make it possible to recover from a badly
1225  * aborted resize operation as much as possible.
1226  *
1227  * In the future, I may further modify this routine to balance out
1228  * where we get the new blocks across the various block groups.
1229  * Ideally we would allocate blocks that corresponded with the block
1230  * group of the containing inode, and keep contiguous blocks
1231  * together.  However, this very difficult to do efficiently, since we
1232  * don't have the necessary information up front.
1233  */
1234
1235 #define AVOID_OLD       1
1236 #define DESPERATION     2
1237
1238 static void init_block_alloc(ext2_resize_t rfs)
1239 {
1240         rfs->alloc_state = AVOID_OLD;
1241         rfs->new_blk = rfs->new_fs->super->s_first_data_block;
1242 #if 0
1243         /* HACK for testing */
1244         if (ext2fs_blocks_count(rfs->new_fs->super) >
1245             ext2fs_blocks_count(rfs->old_fs->super))
1246                 rfs->new_blk = ext2fs_blocks_count(rfs->old_fs->super);
1247 #endif
1248 }
1249
1250 static blk64_t get_new_block(ext2_resize_t rfs)
1251 {
1252         ext2_filsys     fs = rfs->new_fs;
1253
1254         while (1) {
1255                 if (rfs->new_blk >= ext2fs_blocks_count(fs->super)) {
1256                         if (rfs->alloc_state == DESPERATION)
1257                                 return 0;
1258
1259 #ifdef RESIZE2FS_DEBUG
1260                         if (rfs->flags & RESIZE_DEBUG_BMOVE)
1261                                 printf("Going into desperation mode "
1262                                        "for block allocations\n");
1263 #endif
1264                         rfs->alloc_state = DESPERATION;
1265                         rfs->new_blk = fs->super->s_first_data_block;
1266                         continue;
1267                 }
1268                 if (ext2fs_test_block_bitmap2(fs->block_map, rfs->new_blk) ||
1269                     ext2fs_test_block_bitmap2(rfs->reserve_blocks,
1270                                              rfs->new_blk) ||
1271                     ((rfs->alloc_state == AVOID_OLD) &&
1272                      (rfs->new_blk < ext2fs_blocks_count(rfs->old_fs->super)) &&
1273                      ext2fs_test_block_bitmap2(rfs->old_fs->block_map,
1274                                               rfs->new_blk))) {
1275                         rfs->new_blk++;
1276                         continue;
1277                 }
1278                 return rfs->new_blk;
1279         }
1280 }
1281
1282 static errcode_t resize2fs_get_alloc_block(ext2_filsys fs, blk64_t goal,
1283                                            blk64_t *ret)
1284 {
1285         ext2_resize_t rfs = (ext2_resize_t) fs->priv_data;
1286         blk64_t blk;
1287
1288         blk = get_new_block(rfs);
1289         if (!blk)
1290                 return ENOSPC;
1291
1292 #ifdef RESIZE2FS_DEBUG
1293         if (rfs->flags & 0xF)
1294                 printf("get_alloc_block allocating %llu\n", blk);
1295 #endif
1296
1297         ext2fs_mark_block_bitmap2(rfs->old_fs->block_map, blk);
1298         ext2fs_mark_block_bitmap2(rfs->new_fs->block_map, blk);
1299         *ret = (blk64_t) blk;
1300         return 0;
1301 }
1302
1303 static errcode_t block_mover(ext2_resize_t rfs)
1304 {
1305         blk64_t                 blk, old_blk, new_blk;
1306         ext2_filsys             fs = rfs->new_fs;
1307         ext2_filsys             old_fs = rfs->old_fs;
1308         errcode_t               retval;
1309         __u64                   size;
1310         int                     c;
1311         int                     to_move, moved;
1312         ext2_badblocks_list     badblock_list = 0;
1313         int                     bb_modified = 0;
1314
1315         fs->get_alloc_block = resize2fs_get_alloc_block;
1316         old_fs->get_alloc_block = resize2fs_get_alloc_block;
1317
1318         retval = ext2fs_read_bb_inode(old_fs, &badblock_list);
1319         if (retval)
1320                 return retval;
1321
1322         new_blk = fs->super->s_first_data_block;
1323         if (!rfs->itable_buf) {
1324                 retval = ext2fs_get_array(fs->blocksize,
1325                                         fs->inode_blocks_per_group,
1326                                         &rfs->itable_buf);
1327                 if (retval)
1328                         return retval;
1329         }
1330         retval = ext2fs_create_extent_table(&rfs->bmap, 0);
1331         if (retval)
1332                 return retval;
1333
1334         /*
1335          * The first step is to figure out where all of the blocks
1336          * will go.
1337          */
1338         to_move = moved = 0;
1339         init_block_alloc(rfs);
1340         for (blk = B2C(old_fs->super->s_first_data_block);
1341              blk < ext2fs_blocks_count(old_fs->super);
1342              blk += EXT2FS_CLUSTER_RATIO(fs)) {
1343                 if (!ext2fs_test_block_bitmap2(old_fs->block_map, blk))
1344                         continue;
1345                 if (!ext2fs_test_block_bitmap2(rfs->move_blocks, blk))
1346                         continue;
1347                 if (ext2fs_badblocks_list_test(badblock_list, blk)) {
1348                         ext2fs_badblocks_list_del(badblock_list, blk);
1349                         bb_modified++;
1350                         continue;
1351                 }
1352
1353                 new_blk = get_new_block(rfs);
1354                 if (!new_blk) {
1355                         retval = ENOSPC;
1356                         goto errout;
1357                 }
1358                 ext2fs_block_alloc_stats2(fs, new_blk, +1);
1359                 ext2fs_add_extent_entry(rfs->bmap, B2C(blk), B2C(new_blk));
1360                 to_move++;
1361         }
1362
1363         if (to_move == 0) {
1364                 if (rfs->bmap) {
1365                         ext2fs_free_extent_table(rfs->bmap);
1366                         rfs->bmap = 0;
1367                 }
1368                 retval = 0;
1369                 goto errout;
1370         }
1371
1372         /*
1373          * Step two is to actually move the blocks
1374          */
1375         retval =  ext2fs_iterate_extent(rfs->bmap, 0, 0, 0);
1376         if (retval) goto errout;
1377
1378         if (rfs->progress) {
1379                 retval = (rfs->progress)(rfs, E2_RSZ_BLOCK_RELOC_PASS,
1380                                          0, to_move);
1381                 if (retval)
1382                         goto errout;
1383         }
1384         while (1) {
1385                 retval = ext2fs_iterate_extent(rfs->bmap, &old_blk, &new_blk, &size);
1386                 if (retval) goto errout;
1387                 if (!size)
1388                         break;
1389                 old_blk = C2B(old_blk);
1390                 new_blk = C2B(new_blk);
1391                 size = C2B(size);
1392 #ifdef RESIZE2FS_DEBUG
1393                 if (rfs->flags & RESIZE_DEBUG_BMOVE)
1394                         printf("Moving %llu blocks %llu->%llu\n",
1395                                size, old_blk, new_blk);
1396 #endif
1397                 do {
1398                         c = size;
1399                         if (c > fs->inode_blocks_per_group)
1400                                 c = fs->inode_blocks_per_group;
1401                         retval = io_channel_read_blk64(fs->io, old_blk, c,
1402                                                        rfs->itable_buf);
1403                         if (retval) goto errout;
1404                         retval = io_channel_write_blk64(fs->io, new_blk, c,
1405                                                         rfs->itable_buf);
1406                         if (retval) goto errout;
1407                         size -= c;
1408                         new_blk += c;
1409                         old_blk += c;
1410                         moved += c;
1411                         if (rfs->progress) {
1412                                 io_channel_flush(fs->io);
1413                                 retval = (rfs->progress)(rfs,
1414                                                 E2_RSZ_BLOCK_RELOC_PASS,
1415                                                 moved, to_move);
1416                                 if (retval)
1417                                         goto errout;
1418                         }
1419                 } while (size > 0);
1420                 io_channel_flush(fs->io);
1421         }
1422
1423 errout:
1424         if (badblock_list) {
1425                 if (!retval && bb_modified)
1426                         retval = ext2fs_update_bb_inode(old_fs,
1427                                                         badblock_list);
1428                 ext2fs_badblocks_list_free(badblock_list);
1429         }
1430         return retval;
1431 }
1432
1433
1434 /* --------------------------------------------------------------------
1435  *
1436  * Resize processing, phase 3
1437  *
1438  * --------------------------------------------------------------------
1439  */
1440
1441
1442 /*
1443  * The extent translation table is stored in clusters so we need to
1444  * take special care when mapping a source block number to its
1445  * destination block number.
1446  */
1447 static __u64 extent_translate(ext2_filsys fs, ext2_extent extent, __u64 old_loc)
1448 {
1449         __u64 new_block = C2B(ext2fs_extent_translate(extent, B2C(old_loc)));
1450
1451         if (new_block != 0)
1452                 new_block += old_loc & (EXT2FS_CLUSTER_RATIO(fs) - 1);
1453         return new_block;
1454 }
1455
1456 struct process_block_struct {
1457         ext2_resize_t           rfs;
1458         ext2_ino_t              ino;
1459         ext2_ino_t              old_ino;
1460         struct ext2_inode *     inode;
1461         errcode_t               error;
1462         int                     is_dir;
1463         int                     changed;
1464         int                     has_extents;
1465 };
1466
1467 static int process_block(ext2_filsys fs, blk64_t        *block_nr,
1468                          e2_blkcnt_t blockcnt,
1469                          blk64_t ref_block EXT2FS_ATTR((unused)),
1470                          int ref_offset EXT2FS_ATTR((unused)), void *priv_data)
1471 {
1472         struct process_block_struct *pb;
1473         errcode_t       retval;
1474         blk64_t         block, new_block;
1475         int             ret = 0;
1476
1477         pb = (struct process_block_struct *) priv_data;
1478         block = *block_nr;
1479         if (pb->rfs->bmap) {
1480                 new_block = extent_translate(fs, pb->rfs->bmap, block);
1481                 if (new_block) {
1482                         *block_nr = new_block;
1483                         ret |= BLOCK_CHANGED;
1484                         pb->changed = 1;
1485 #ifdef RESIZE2FS_DEBUG
1486                         if (pb->rfs->flags & RESIZE_DEBUG_BMOVE)
1487                                 printf("ino=%u, blockcnt=%lld, %llu->%llu\n",
1488                                        pb->old_ino, blockcnt, block,
1489                                        new_block);
1490 #endif
1491                         block = new_block;
1492                 }
1493         }
1494
1495         /*
1496          * If we moved inodes and metadata_csum is enabled, we must force the
1497          * extent block to be rewritten with new checksum.
1498          */
1499         if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
1500                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
1501             pb->has_extents &&
1502             pb->old_ino != pb->ino)
1503                 ret |= BLOCK_CHANGED;
1504
1505         if (pb->is_dir) {
1506                 retval = ext2fs_add_dir_block2(fs->dblist, pb->ino,
1507                                                block, (int) blockcnt);
1508                 if (retval) {
1509                         pb->error = retval;
1510                         ret |= BLOCK_ABORT;
1511                 }
1512         }
1513         return ret;
1514 }
1515
1516 /*
1517  * Progress callback
1518  */
1519 static errcode_t progress_callback(ext2_filsys fs,
1520                                    ext2_inode_scan scan EXT2FS_ATTR((unused)),
1521                                    dgrp_t group, void * priv_data)
1522 {
1523         ext2_resize_t rfs = (ext2_resize_t) priv_data;
1524         errcode_t               retval;
1525
1526         /*
1527          * This check is to protect against old ext2 libraries.  It
1528          * shouldn't be needed against new libraries.
1529          */
1530         if ((group+1) == 0)
1531                 return 0;
1532
1533         if (rfs->progress) {
1534                 io_channel_flush(fs->io);
1535                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
1536                                          group+1, fs->group_desc_count);
1537                 if (retval)
1538                         return retval;
1539         }
1540
1541         return 0;
1542 }
1543
1544 static errcode_t migrate_ea_block(ext2_resize_t rfs, ext2_ino_t ino,
1545                                   struct ext2_inode *inode, int *changed)
1546 {
1547         char *buf;
1548         blk64_t new_block;
1549         errcode_t err = 0;
1550
1551         /* No EA block or no remapping?  Quit early. */
1552         if (ext2fs_file_acl_block(rfs->old_fs, inode) == 0 && !rfs->bmap)
1553                 return 0;
1554         new_block = extent_translate(rfs->old_fs, rfs->bmap,
1555                 ext2fs_file_acl_block(rfs->old_fs, inode));
1556         if (new_block == 0)
1557                 return 0;
1558
1559         /* Set the new ACL block */
1560         ext2fs_file_acl_block_set(rfs->old_fs, inode, new_block);
1561
1562         /* Update checksum */
1563         if (EXT2_HAS_RO_COMPAT_FEATURE(rfs->new_fs->super,
1564                         EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
1565                 err = ext2fs_get_mem(rfs->old_fs->blocksize, &buf);
1566                 if (err)
1567                         return err;
1568                 rfs->old_fs->flags |= EXT2_FLAG_IGNORE_CSUM_ERRORS;
1569                 err = ext2fs_read_ext_attr3(rfs->old_fs, new_block, buf, ino);
1570                 rfs->old_fs->flags &= ~EXT2_FLAG_IGNORE_CSUM_ERRORS;
1571                 if (err)
1572                         goto out;
1573                 err = ext2fs_write_ext_attr3(rfs->old_fs, new_block, buf, ino);
1574                 if (err)
1575                         goto out;
1576         }
1577         *changed = 1;
1578
1579 out:
1580         ext2fs_free_mem(&buf);
1581         return err;
1582 }
1583
1584 static errcode_t inode_scan_and_fix(ext2_resize_t rfs)
1585 {
1586         struct process_block_struct     pb;
1587         ext2_ino_t              ino, new_inode;
1588         struct ext2_inode       *inode = NULL;
1589         ext2_inode_scan         scan = NULL;
1590         errcode_t               retval;
1591         char                    *block_buf = 0;
1592         ext2_ino_t              start_to_move;
1593         blk64_t                 orig_size;
1594         int                     inode_size;
1595
1596         if ((rfs->old_fs->group_desc_count <=
1597              rfs->new_fs->group_desc_count) &&
1598             !rfs->bmap)
1599                 return 0;
1600
1601         /*
1602          * Save the original size of the old filesystem, and
1603          * temporarily set the size to be the new size if the new size
1604          * is larger.  We need to do this to avoid catching an error
1605          * by the block iterator routines
1606          */
1607         orig_size = ext2fs_blocks_count(rfs->old_fs->super);
1608         if (orig_size < ext2fs_blocks_count(rfs->new_fs->super))
1609                 ext2fs_blocks_count_set(rfs->old_fs->super,
1610                                 ext2fs_blocks_count(rfs->new_fs->super));
1611
1612         retval = ext2fs_open_inode_scan(rfs->old_fs, 0, &scan);
1613         if (retval) goto errout;
1614
1615         retval = ext2fs_init_dblist(rfs->old_fs, 0);
1616         if (retval) goto errout;
1617         retval = ext2fs_get_array(rfs->old_fs->blocksize, 3, &block_buf);
1618         if (retval) goto errout;
1619
1620         start_to_move = (rfs->new_fs->group_desc_count *
1621                          rfs->new_fs->super->s_inodes_per_group);
1622
1623         if (rfs->progress) {
1624                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
1625                                          0, rfs->old_fs->group_desc_count);
1626                 if (retval)
1627                         goto errout;
1628         }
1629         ext2fs_set_inode_callback(scan, progress_callback, (void *) rfs);
1630         pb.rfs = rfs;
1631         pb.inode = inode;
1632         pb.error = 0;
1633         new_inode = EXT2_FIRST_INODE(rfs->new_fs->super);
1634         inode_size = EXT2_INODE_SIZE(rfs->new_fs->super);
1635         inode = malloc(inode_size);
1636         if (!inode) {
1637                 retval = ENOMEM;
1638                 goto errout;
1639         }
1640         /*
1641          * First, copy all of the inodes that need to be moved
1642          * elsewhere in the inode table
1643          */
1644         while (1) {
1645                 retval = ext2fs_get_next_inode_full(scan, &ino, inode, inode_size);
1646                 if (retval) goto errout;
1647                 if (!ino)
1648                         break;
1649
1650                 if (inode->i_links_count == 0 && ino != EXT2_RESIZE_INO)
1651                         continue; /* inode not in use */
1652
1653                 pb.is_dir = LINUX_S_ISDIR(inode->i_mode);
1654                 pb.changed = 0;
1655
1656                 /* Remap EA block */
1657                 retval = migrate_ea_block(rfs, ino, inode, &pb.changed);
1658                 if (retval)
1659                         goto errout;
1660
1661                 new_inode = ino;
1662                 if (ino <= start_to_move)
1663                         goto remap_blocks; /* Don't need to move inode. */
1664
1665                 /*
1666                  * Find a new inode.  Now that extents and directory blocks
1667                  * are tied to the inode number through the checksum, we must
1668                  * set up the new inode before we start rewriting blocks.
1669                  */
1670                 retval = ext2fs_new_inode(rfs->new_fs, 0, 0, 0, &new_inode);
1671                 if (retval)
1672                         goto errout;
1673
1674                 ext2fs_inode_alloc_stats2(rfs->new_fs, new_inode, +1,
1675                                           pb.is_dir);
1676                 inode->i_ctime = time(0);
1677                 retval = ext2fs_write_inode_full(rfs->old_fs, new_inode,
1678                                                 inode, inode_size);
1679                 if (retval)
1680                         goto errout;
1681                 pb.changed = 0;
1682
1683 #ifdef RESIZE2FS_DEBUG
1684                 if (rfs->flags & RESIZE_DEBUG_INODEMAP)
1685                         printf("Inode moved %u->%u\n", ino, new_inode);
1686 #endif
1687                 if (!rfs->imap) {
1688                         retval = ext2fs_create_extent_table(&rfs->imap, 0);
1689                         if (retval)
1690                                 goto errout;
1691                 }
1692                 ext2fs_add_extent_entry(rfs->imap, ino, new_inode);
1693
1694 remap_blocks:
1695                 if (pb.changed)
1696                         retval = ext2fs_write_inode_full(rfs->old_fs,
1697                                                          new_inode,
1698                                                          inode, inode_size);
1699                 if (retval)
1700                         goto errout;
1701
1702                 /*
1703                  * Update inodes to point to new blocks; schedule directory
1704                  * blocks for inode remapping.  Need to write out dir blocks
1705                  * with new inode numbers if we have metadata_csum enabled.
1706                  */
1707                 if (ext2fs_inode_has_valid_blocks2(rfs->old_fs, inode) &&
1708                     (rfs->bmap || pb.is_dir)) {
1709                         pb.ino = new_inode;
1710                         pb.old_ino = ino;
1711                         pb.has_extents = inode->i_flags & EXT4_EXTENTS_FL;
1712                         rfs->old_fs->flags |= EXT2_FLAG_IGNORE_CSUM_ERRORS;
1713                         retval = ext2fs_block_iterate3(rfs->old_fs,
1714                                                        new_inode, 0, block_buf,
1715                                                        process_block, &pb);
1716                         rfs->old_fs->flags &= ~EXT2_FLAG_IGNORE_CSUM_ERRORS;
1717                         if (retval)
1718                                 goto errout;
1719                         if (pb.error) {
1720                                 retval = pb.error;
1721                                 goto errout;
1722                         }
1723                 } else if ((inode->i_flags & EXT4_INLINE_DATA_FL) &&
1724                            (rfs->bmap || pb.is_dir)) {
1725                         /* inline data dir; update it too */
1726                         retval = ext2fs_add_dir_block2(rfs->old_fs->dblist,
1727                                                        new_inode, 0, 0);
1728                         if (retval)
1729                                 goto errout;
1730                 }
1731         }
1732         io_channel_flush(rfs->old_fs->io);
1733
1734 errout:
1735         ext2fs_blocks_count_set(rfs->old_fs->super, orig_size);
1736         if (rfs->bmap) {
1737                 ext2fs_free_extent_table(rfs->bmap);
1738                 rfs->bmap = 0;
1739         }
1740         if (scan)
1741                 ext2fs_close_inode_scan(scan);
1742         if (block_buf)
1743                 ext2fs_free_mem(&block_buf);
1744         free(inode);
1745         return retval;
1746 }
1747
1748 /* --------------------------------------------------------------------
1749  *
1750  * Resize processing, phase 4.
1751  *
1752  * --------------------------------------------------------------------
1753  */
1754
1755 struct istruct {
1756         ext2_resize_t rfs;
1757         errcode_t       err;
1758         unsigned int    max_dirs;
1759         unsigned int    num;
1760 };
1761
1762 static int check_and_change_inodes(ext2_ino_t dir,
1763                                    int entry EXT2FS_ATTR((unused)),
1764                                    struct ext2_dir_entry *dirent, int offset,
1765                                    int  blocksize EXT2FS_ATTR((unused)),
1766                                    char *buf EXT2FS_ATTR((unused)),
1767                                    void *priv_data)
1768 {
1769         struct istruct *is = (struct istruct *) priv_data;
1770         struct ext2_inode       inode;
1771         ext2_ino_t              new_inode;
1772         errcode_t               retval;
1773         int                     ret = 0;
1774
1775         if (is->rfs->progress && offset == 0) {
1776                 io_channel_flush(is->rfs->old_fs->io);
1777                 is->err = (is->rfs->progress)(is->rfs,
1778                                               E2_RSZ_INODE_REF_UPD_PASS,
1779                                               ++is->num, is->max_dirs);
1780                 if (is->err)
1781                         return DIRENT_ABORT;
1782         }
1783
1784         /*
1785          * If we have checksums enabled and the inode wasn't present in the
1786          * old fs, then we must rewrite all dir blocks with new checksums.
1787          */
1788         if (EXT2_HAS_RO_COMPAT_FEATURE(is->rfs->old_fs->super,
1789                                        EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
1790             !ext2fs_test_inode_bitmap2(is->rfs->old_fs->inode_map, dir))
1791                 ret |= DIRENT_CHANGED;
1792
1793         if (!dirent->inode)
1794                 return ret;
1795
1796         new_inode = ext2fs_extent_translate(is->rfs->imap, dirent->inode);
1797
1798         if (!new_inode)
1799                 return ret;
1800 #ifdef RESIZE2FS_DEBUG
1801         if (is->rfs->flags & RESIZE_DEBUG_INODEMAP)
1802                 printf("Inode translate (dir=%u, name=%.*s, %u->%u)\n",
1803                        dir, ext2fs_dirent_name_len(dirent), dirent->name,
1804                        dirent->inode, new_inode);
1805 #endif
1806
1807         dirent->inode = new_inode;
1808
1809         /* Update the directory mtime and ctime */
1810         retval = ext2fs_read_inode(is->rfs->old_fs, dir, &inode);
1811         if (retval == 0) {
1812                 inode.i_mtime = inode.i_ctime = time(0);
1813                 is->err = ext2fs_write_inode(is->rfs->old_fs, dir, &inode);
1814                 if (is->err)
1815                         return ret | DIRENT_ABORT;
1816         }
1817
1818         return ret | DIRENT_CHANGED;
1819 }
1820
1821 static errcode_t inode_ref_fix(ext2_resize_t rfs)
1822 {
1823         errcode_t               retval;
1824         struct istruct          is;
1825
1826         if (!rfs->imap)
1827                 return 0;
1828
1829         /*
1830          * Now, we iterate over all of the directories to update the
1831          * inode references
1832          */
1833         is.num = 0;
1834         is.max_dirs = ext2fs_dblist_count2(rfs->old_fs->dblist);
1835         is.rfs = rfs;
1836         is.err = 0;
1837
1838         if (rfs->progress) {
1839                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS,
1840                                          0, is.max_dirs);
1841                 if (retval)
1842                         goto errout;
1843         }
1844
1845         rfs->old_fs->flags |= EXT2_FLAG_IGNORE_CSUM_ERRORS;
1846         retval = ext2fs_dblist_dir_iterate(rfs->old_fs->dblist,
1847                                            DIRENT_FLAG_INCLUDE_EMPTY, 0,
1848                                            check_and_change_inodes, &is);
1849         rfs->old_fs->flags &= ~EXT2_FLAG_IGNORE_CSUM_ERRORS;
1850         if (retval)
1851                 goto errout;
1852         if (is.err) {
1853                 retval = is.err;
1854                 goto errout;
1855         }
1856
1857         if (rfs->progress && (is.num < is.max_dirs))
1858                 (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS,
1859                                 is.max_dirs, is.max_dirs);
1860
1861 errout:
1862         ext2fs_free_extent_table(rfs->imap);
1863         rfs->imap = 0;
1864         return retval;
1865 }
1866
1867
1868 /* --------------------------------------------------------------------
1869  *
1870  * Resize processing, phase 5.
1871  *
1872  * In this phase we actually move the inode table around, and then
1873  * update the summary statistics.  This is scary, since aborting here
1874  * will potentially scramble the filesystem.  (We are moving the
1875  * inode tables around in place, and so the potential for lost data,
1876  * or at the very least scrambling the mapping between filenames and
1877  * inode numbers is very high in case of a power failure here.)
1878  * --------------------------------------------------------------------
1879  */
1880
1881
1882 /*
1883  * A very scary routine --- this one moves the inode table around!!!
1884  *
1885  * After this you have to use the rfs->new_fs file handle to read and
1886  * write inodes.
1887  */
1888 static errcode_t move_itables(ext2_resize_t rfs)
1889 {
1890         int             n, num, size;
1891         long long       diff;
1892         dgrp_t          i, max_groups;
1893         ext2_filsys     fs = rfs->new_fs;
1894         char            *cp;
1895         blk64_t         old_blk, new_blk, blk, cluster_freed;
1896         errcode_t       retval;
1897         int             j, to_move, moved;
1898         ext2fs_block_bitmap     new_bmap = NULL;
1899
1900         max_groups = fs->group_desc_count;
1901         if (max_groups > rfs->old_fs->group_desc_count)
1902                 max_groups = rfs->old_fs->group_desc_count;
1903
1904         size = fs->blocksize * fs->inode_blocks_per_group;
1905         if (!rfs->itable_buf) {
1906                 retval = ext2fs_get_mem(size, &rfs->itable_buf);
1907                 if (retval)
1908                         return retval;
1909         }
1910
1911         if (EXT2FS_CLUSTER_RATIO(fs) > 1) {
1912                 retval = ext2fs_allocate_block_bitmap(fs, _("new meta blocks"),
1913                                                       &new_bmap);
1914                 if (retval)
1915                         return retval;
1916
1917                 retval = mark_table_blocks(fs, new_bmap);
1918                 if (retval)
1919                         goto errout;
1920         }
1921
1922         /*
1923          * Figure out how many inode tables we need to move
1924          */
1925         to_move = moved = 0;
1926         for (i=0; i < max_groups; i++)
1927                 if (ext2fs_inode_table_loc(rfs->old_fs, i) !=
1928                     ext2fs_inode_table_loc(fs, i))
1929                         to_move++;
1930
1931         if (to_move == 0)
1932                 return 0;
1933
1934         if (rfs->progress) {
1935                 retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
1936                                        0, to_move);
1937                 if (retval)
1938                         goto errout;
1939         }
1940
1941         rfs->old_fs->flags |= EXT2_FLAG_MASTER_SB_ONLY;
1942
1943         for (i=0; i < max_groups; i++) {
1944                 old_blk = ext2fs_inode_table_loc(rfs->old_fs, i);
1945                 new_blk = ext2fs_inode_table_loc(fs, i);
1946                 diff = new_blk - old_blk;
1947
1948 #ifdef RESIZE2FS_DEBUG
1949                 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1950                         printf("Itable move group %d block %llu->%llu (diff %lld)\n",
1951                                i, old_blk, new_blk, diff);
1952 #endif
1953
1954                 if (!diff)
1955                         continue;
1956                 if (diff < 0)
1957                         diff = 0;
1958
1959                 retval = io_channel_read_blk64(fs->io, old_blk,
1960                                                fs->inode_blocks_per_group,
1961                                                rfs->itable_buf);
1962                 if (retval)
1963                         goto errout;
1964                 /*
1965                  * The end of the inode table segment often contains
1966                  * all zeros, and we're often only moving the inode
1967                  * table down a block or two.  If so, we can optimize
1968                  * things by not rewriting blocks that we know to be zero
1969                  * already.
1970                  */
1971                 for (cp = rfs->itable_buf+size-1, n=0; n < size; n++, cp--)
1972                         if (*cp)
1973                                 break;
1974                 n = n >> EXT2_BLOCK_SIZE_BITS(fs->super);
1975 #ifdef RESIZE2FS_DEBUG
1976                 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1977                         printf("%d blocks of zeros...\n", n);
1978 #endif
1979                 num = fs->inode_blocks_per_group;
1980                 if (n > diff)
1981                         num -= n;
1982
1983                 retval = io_channel_write_blk64(fs->io, new_blk,
1984                                                 num, rfs->itable_buf);
1985                 if (retval) {
1986                         io_channel_write_blk64(fs->io, old_blk,
1987                                                num, rfs->itable_buf);
1988                         goto errout;
1989                 }
1990                 if (n > diff) {
1991                         retval = io_channel_write_blk64(fs->io,
1992                               old_blk + fs->inode_blocks_per_group,
1993                               diff, (rfs->itable_buf +
1994                                      (fs->inode_blocks_per_group - diff) *
1995                                      fs->blocksize));
1996                         if (retval)
1997                                 goto errout;
1998                 }
1999
2000                 for (blk = ext2fs_inode_table_loc(rfs->old_fs, i), j=0;
2001                      j < fs->inode_blocks_per_group;) {
2002                         if (new_bmap == NULL ||
2003                             !ext2fs_test_block_bitmap2(new_bmap, blk)) {
2004                                 ext2fs_block_alloc_stats2(fs, blk, -1);
2005                                 cluster_freed = EXT2FS_CLUSTER_RATIO(fs) -
2006                                                 (blk & EXT2FS_CLUSTER_MASK(fs));
2007                                 blk += cluster_freed;
2008                                 j += cluster_freed;
2009                                 continue;
2010                         }
2011                         blk++;
2012                         j++;
2013                 }
2014
2015                 ext2fs_inode_table_loc_set(rfs->old_fs, i, new_blk);
2016                 ext2fs_group_desc_csum_set(rfs->old_fs, i);
2017                 ext2fs_mark_super_dirty(rfs->old_fs);
2018                 ext2fs_flush(rfs->old_fs);
2019
2020                 if (rfs->progress) {
2021                         retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
2022                                                ++moved, to_move);
2023                         if (retval)
2024                                 goto errout;
2025                 }
2026         }
2027         mark_table_blocks(fs, fs->block_map);
2028         ext2fs_flush(fs);
2029 #ifdef RESIZE2FS_DEBUG
2030         if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
2031                 printf("Inode table move finished.\n");
2032 #endif
2033         retval = 0;
2034
2035 errout:
2036         if (new_bmap)
2037                 ext2fs_free_block_bitmap(new_bmap);
2038         return retval;
2039 }
2040
2041 /*
2042  * This function is used when expanding a file system.  It frees the
2043  * superblock and block group descriptor blocks from the block group
2044  * which is no longer the last block group.
2045  */
2046 static errcode_t clear_sparse_super2_last_group(ext2_resize_t rfs)
2047 {
2048         ext2_filsys     fs = rfs->new_fs;
2049         ext2_filsys     old_fs = rfs->old_fs;
2050         errcode_t       retval;
2051         dgrp_t          old_last_bg = rfs->old_fs->group_desc_count - 1;
2052         dgrp_t          last_bg = fs->group_desc_count - 1;
2053         blk64_t         sb, old_desc;
2054         blk_t           num;
2055
2056         if (!(fs->super->s_feature_compat & EXT4_FEATURE_COMPAT_SPARSE_SUPER2))
2057                 return 0;
2058
2059         if (last_bg <= old_last_bg)
2060                 return 0;
2061
2062         if (fs->super->s_backup_bgs[0] == old_fs->super->s_backup_bgs[0] &&
2063             fs->super->s_backup_bgs[1] == old_fs->super->s_backup_bgs[1])
2064                 return 0;
2065
2066         if (old_fs->super->s_backup_bgs[0] != old_last_bg &&
2067             old_fs->super->s_backup_bgs[1] != old_last_bg)
2068                 return 0;
2069
2070         if (fs->super->s_backup_bgs[0] == old_last_bg ||
2071             fs->super->s_backup_bgs[1] == old_last_bg)
2072                 return 0;
2073
2074         retval = ext2fs_super_and_bgd_loc2(rfs->old_fs, old_last_bg,
2075                                            &sb, &old_desc, NULL, &num);
2076         if (retval)
2077                 return retval;
2078
2079         if (sb)
2080                 ext2fs_unmark_block_bitmap2(fs->block_map, sb);
2081         if (old_desc)
2082                 ext2fs_unmark_block_bitmap_range2(fs->block_map, old_desc, num);
2083         return 0;
2084 }
2085
2086 /*
2087  * This function is used when shrinking a file system.  We need to
2088  * utilize blocks from what will be the new last block group for the
2089  * backup superblock and block group descriptor blocks.
2090  * Unfortunately, those blocks may be used by other files or fs
2091  * metadata blocks.  We need to mark them as being in use.
2092  */
2093 static errcode_t reserve_sparse_super2_last_group(ext2_resize_t rfs,
2094                                                  ext2fs_block_bitmap meta_bmap)
2095 {
2096         ext2_filsys     fs = rfs->new_fs;
2097         ext2_filsys     old_fs = rfs->old_fs;
2098         errcode_t       retval;
2099         dgrp_t          old_last_bg = rfs->old_fs->group_desc_count - 1;
2100         dgrp_t          last_bg = fs->group_desc_count - 1;
2101         dgrp_t          g;
2102         blk64_t         blk, sb, old_desc;
2103         blk_t           i, num;
2104         int             realloc = 0;
2105
2106         if (!(fs->super->s_feature_compat & EXT4_FEATURE_COMPAT_SPARSE_SUPER2))
2107                 return 0;
2108
2109         if (last_bg >= old_last_bg)
2110                 return 0;
2111
2112         if (fs->super->s_backup_bgs[0] == old_fs->super->s_backup_bgs[0] &&
2113             fs->super->s_backup_bgs[1] == old_fs->super->s_backup_bgs[1])
2114                 return 0;
2115
2116         if (fs->super->s_backup_bgs[0] != last_bg &&
2117             fs->super->s_backup_bgs[1] != last_bg)
2118                 return 0;
2119
2120         if (old_fs->super->s_backup_bgs[0] == last_bg ||
2121             old_fs->super->s_backup_bgs[1] == last_bg)
2122                 return 0;
2123
2124         retval = ext2fs_super_and_bgd_loc2(rfs->new_fs, last_bg,
2125                                            &sb, &old_desc, NULL, &num);
2126         if (retval)
2127                 return retval;
2128
2129         if (!sb) {
2130                 fputs(_("Should never happen!  No sb in last super_sparse bg?\n"),
2131                       stderr);
2132                 exit(1);
2133         }
2134         if (old_desc && old_desc != sb+1) {
2135                 fputs(_("Should never happen!  Unexpected old_desc in "
2136                         "super_sparse bg?\n"),
2137                       stderr);
2138                 exit(1);
2139         }
2140         num = (old_desc) ? num : 1;
2141
2142         /* Reserve the backup blocks */
2143         ext2fs_mark_block_bitmap_range2(fs->block_map, sb, num);
2144
2145         for (g = 0; g < fs->group_desc_count; g++) {
2146                 blk64_t mb;
2147
2148                 mb = ext2fs_block_bitmap_loc(fs, g);
2149                 if ((mb >= sb) && (mb < sb + num)) {
2150                         ext2fs_block_bitmap_loc_set(fs, g, 0);
2151                         realloc = 1;
2152                 }
2153                 mb = ext2fs_inode_bitmap_loc(fs, g);
2154                 if ((mb >= sb) && (mb < sb + num)) {
2155                         ext2fs_inode_bitmap_loc_set(fs, g, 0);
2156                         realloc = 1;
2157                 }
2158                 mb = ext2fs_inode_table_loc(fs, g);
2159                 if ((mb < sb + num) &&
2160                     (sb < mb + fs->inode_blocks_per_group)) {
2161                         ext2fs_inode_table_loc_set(fs, g, 0);
2162                         realloc = 1;
2163                 }
2164                 if (realloc) {
2165                         retval = ext2fs_allocate_group_table(fs, g, 0);
2166                         if (retval)
2167                                 return retval;
2168                 }
2169         }
2170
2171         for (blk = sb, i = 0; i < num; blk++, i++) {
2172                 if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
2173                     !ext2fs_test_block_bitmap2(meta_bmap, blk)) {
2174                         ext2fs_mark_block_bitmap2(rfs->move_blocks, blk);
2175                         rfs->needed_blocks++;
2176                 }
2177                 ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
2178         }
2179         return 0;
2180 }
2181
2182 /*
2183  * Fix the resize inode
2184  */
2185 static errcode_t fix_resize_inode(ext2_filsys fs)
2186 {
2187         struct ext2_inode       inode;
2188         errcode_t               retval;
2189         char                    *block_buf = NULL;
2190
2191         if (!(fs->super->s_feature_compat &
2192               EXT2_FEATURE_COMPAT_RESIZE_INODE))
2193                 return 0;
2194
2195         retval = ext2fs_get_mem(fs->blocksize, &block_buf);
2196         if (retval) goto errout;
2197
2198         retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode);
2199         if (retval) goto errout;
2200
2201         ext2fs_iblk_set(fs, &inode, 1);
2202
2203         retval = ext2fs_write_inode(fs, EXT2_RESIZE_INO, &inode);
2204         if (retval) goto errout;
2205
2206         if (!inode.i_block[EXT2_DIND_BLOCK]) {
2207                 /*
2208                  * Avoid zeroing out block #0; that's rude.  This
2209                  * should never happen anyway since the filesystem
2210                  * should be fsck'ed and we assume it is consistent.
2211                  */
2212                 fprintf(stderr, "%s",
2213                         _("Should never happen: resize inode corrupt!\n"));
2214                 exit(1);
2215         }
2216
2217         memset(block_buf, 0, fs->blocksize);
2218
2219         retval = io_channel_write_blk64(fs->io, inode.i_block[EXT2_DIND_BLOCK],
2220                                         1, block_buf);
2221         if (retval) goto errout;
2222
2223         retval = ext2fs_create_resize_inode(fs);
2224         if (retval)
2225                 goto errout;
2226
2227 errout:
2228         if (block_buf)
2229                 ext2fs_free_mem(&block_buf);
2230         return retval;
2231 }
2232
2233 /*
2234  * Finally, recalculate the summary information
2235  */
2236 static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs)
2237 {
2238         blk64_t         blk;
2239         ext2_ino_t      ino;
2240         unsigned int    group = 0;
2241         unsigned int    count = 0;
2242         blk64_t         total_blocks_free = 0;
2243         int             total_inodes_free = 0;
2244         int             group_free = 0;
2245         int             uninit = 0;
2246         blk64_t         super_blk, old_desc_blk, new_desc_blk;
2247         int             old_desc_blocks;
2248
2249         /*
2250          * First calculate the block statistics
2251          */
2252         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT);
2253         ext2fs_super_and_bgd_loc2(fs, group, &super_blk, &old_desc_blk,
2254                                   &new_desc_blk, 0);
2255         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
2256                 old_desc_blocks = fs->super->s_first_meta_bg;
2257         else
2258                 old_desc_blocks = fs->desc_blocks +
2259                         fs->super->s_reserved_gdt_blocks;
2260         for (blk = B2C(fs->super->s_first_data_block);
2261              blk < ext2fs_blocks_count(fs->super);
2262              blk += EXT2FS_CLUSTER_RATIO(fs)) {
2263                 if ((uninit &&
2264                      !(EQ_CLSTR(blk, super_blk) ||
2265                        ((old_desc_blk && old_desc_blocks &&
2266                          GE_CLSTR(blk, old_desc_blk) &&
2267                          LT_CLSTR(blk, old_desc_blk + old_desc_blocks))) ||
2268                        ((new_desc_blk && EQ_CLSTR(blk, new_desc_blk))) ||
2269                        EQ_CLSTR(blk, ext2fs_block_bitmap_loc(fs, group)) ||
2270                        EQ_CLSTR(blk, ext2fs_inode_bitmap_loc(fs, group)) ||
2271                        ((GE_CLSTR(blk, ext2fs_inode_table_loc(fs, group)) &&
2272                          LT_CLSTR(blk, ext2fs_inode_table_loc(fs, group)
2273                                   + fs->inode_blocks_per_group))))) ||
2274                     (!ext2fs_fast_test_block_bitmap2(fs->block_map, blk))) {
2275                         group_free++;
2276                         total_blocks_free++;
2277                 }
2278                 count++;
2279                 if ((count == fs->super->s_clusters_per_group) ||
2280                     EQ_CLSTR(blk, ext2fs_blocks_count(fs->super)-1)) {
2281                         ext2fs_bg_free_blocks_count_set(fs, group, group_free);
2282                         ext2fs_group_desc_csum_set(fs, group);
2283                         group++;
2284                         if (group >= fs->group_desc_count)
2285                                 break;
2286                         count = 0;
2287                         group_free = 0;
2288                         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT);
2289                         ext2fs_super_and_bgd_loc2(fs, group, &super_blk,
2290                                                   &old_desc_blk,
2291                                                   &new_desc_blk, 0);
2292                         if (fs->super->s_feature_incompat &
2293                             EXT2_FEATURE_INCOMPAT_META_BG)
2294                                 old_desc_blocks = fs->super->s_first_meta_bg;
2295                         else
2296                                 old_desc_blocks = fs->desc_blocks +
2297                                         fs->super->s_reserved_gdt_blocks;
2298                 }
2299         }
2300         total_blocks_free = C2B(total_blocks_free);
2301         ext2fs_free_blocks_count_set(fs->super, total_blocks_free);
2302
2303         /*
2304          * Next, calculate the inode statistics
2305          */
2306         group_free = 0;
2307         count = 0;
2308         group = 0;
2309
2310         /* Protect loop from wrap-around if s_inodes_count maxed */
2311         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT);
2312         for (ino = 1; ino <= fs->super->s_inodes_count && ino > 0; ino++) {
2313                 if (uninit ||
2314                     !ext2fs_fast_test_inode_bitmap2(fs->inode_map, ino)) {
2315                         group_free++;
2316                         total_inodes_free++;
2317                 }
2318                 count++;
2319                 if ((count == fs->super->s_inodes_per_group) ||
2320                     (ino == fs->super->s_inodes_count)) {
2321                         ext2fs_bg_free_inodes_count_set(fs, group, group_free);
2322                         ext2fs_group_desc_csum_set(fs, group);
2323                         group++;
2324                         if (group >= fs->group_desc_count)
2325                                 break;
2326                         count = 0;
2327                         group_free = 0;
2328                         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT);
2329                 }
2330         }
2331         fs->super->s_free_inodes_count = total_inodes_free;
2332         ext2fs_mark_super_dirty(fs);
2333         return 0;
2334 }
2335
2336 /*
2337  *  Journal may have been relocated; update the backup journal blocks
2338  *  in the superblock.
2339  */
2340 static errcode_t fix_sb_journal_backup(ext2_filsys fs)
2341 {
2342         errcode_t         retval;
2343         struct ext2_inode inode;
2344
2345         if (!(fs->super->s_feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL))
2346                 return 0;
2347
2348         /* External journal? Nothing to do. */
2349         if (fs->super->s_journal_dev && !fs->super->s_journal_inum)
2350                 return 0;
2351
2352         retval = ext2fs_read_inode(fs, fs->super->s_journal_inum, &inode);
2353         if (retval)
2354                 return retval;
2355         memcpy(fs->super->s_jnl_blocks, inode.i_block, EXT2_N_BLOCKS*4);
2356         fs->super->s_jnl_blocks[15] = inode.i_size_high;
2357         fs->super->s_jnl_blocks[16] = inode.i_size;
2358         fs->super->s_jnl_backup_type = EXT3_JNL_BACKUP_BLOCKS;
2359         ext2fs_mark_super_dirty(fs);
2360         return 0;
2361 }
2362
2363 static int calc_group_overhead(ext2_filsys fs, blk64_t grp,
2364                                int old_desc_blocks)
2365 {
2366         blk64_t super_blk, old_desc_blk, new_desc_blk;
2367         int overhead;
2368
2369         /* inode table blocks plus allocation bitmaps */
2370         overhead = fs->inode_blocks_per_group + 2;
2371
2372         ext2fs_super_and_bgd_loc2(fs, grp, &super_blk,
2373                                   &old_desc_blk, &new_desc_blk, 0);
2374         if ((grp == 0) || super_blk)
2375                 overhead++;
2376         if (old_desc_blk)
2377                 overhead += old_desc_blocks;
2378         else if (new_desc_blk)
2379                 overhead++;
2380         return overhead;
2381 }
2382
2383
2384 /*
2385  * calcluate the minimum number of blocks the given fs can be resized to
2386  */
2387 blk64_t calculate_minimum_resize_size(ext2_filsys fs, int flags)
2388 {
2389         ext2_ino_t inode_count;
2390         dgrp_t groups, flex_groups;
2391         blk64_t blks_needed, data_blocks;
2392         blk64_t grp, data_needed, last_start;
2393         blk64_t overhead = 0;
2394         int old_desc_blocks;
2395         int flexbg_size = 1 << fs->super->s_log_groups_per_flex;
2396
2397         /*
2398          * first figure out how many group descriptors we need to
2399          * handle the number of inodes we have
2400          */
2401         inode_count = fs->super->s_inodes_count -
2402                 fs->super->s_free_inodes_count;
2403         blks_needed = ext2fs_div_ceil(inode_count,
2404                                       fs->super->s_inodes_per_group) *
2405                 (blk64_t) EXT2_BLOCKS_PER_GROUP(fs->super);
2406         groups = ext2fs_div64_ceil(blks_needed,
2407                                    EXT2_BLOCKS_PER_GROUP(fs->super));
2408 #ifdef RESIZE2FS_DEBUG
2409         if (flags & RESIZE_DEBUG_MIN_CALC)
2410                 printf("fs has %d inodes, %d groups required.\n",
2411                        inode_count, groups);
2412 #endif
2413
2414         /*
2415          * number of old-style block group descriptor blocks
2416          */
2417         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
2418                 old_desc_blocks = fs->super->s_first_meta_bg;
2419         else
2420                 old_desc_blocks = fs->desc_blocks +
2421                         fs->super->s_reserved_gdt_blocks;
2422
2423         /* calculate how many blocks are needed for data */
2424         data_needed = ext2fs_blocks_count(fs->super) -
2425                 ext2fs_free_blocks_count(fs->super);
2426
2427         for (grp = 0; grp < fs->group_desc_count; grp++)
2428                 data_needed -= calc_group_overhead(fs, grp, old_desc_blocks);
2429 #ifdef RESIZE2FS_DEBUG
2430         if (flags & RESIZE_DEBUG_MIN_CALC)
2431                 printf("fs requires %llu data blocks.\n", data_needed);
2432 #endif
2433
2434         /*
2435          * For ext4 we need to allow for up to a flex_bg worth of
2436          * inode tables of slack space so the resize operation can be
2437          * guaranteed to finish.
2438          */
2439         flex_groups = groups;
2440         if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_FLEX_BG) {
2441                 dgrp_t remainder = groups & (flexbg_size - 1);
2442
2443                 flex_groups += flexbg_size - remainder;
2444                 if (flex_groups > fs->group_desc_count)
2445                         flex_groups = fs->group_desc_count;
2446         }
2447
2448         /*
2449          * figure out how many data blocks we have given the number of groups
2450          * we need for our inodes
2451          */
2452         data_blocks = EXT2_GROUPS_TO_BLOCKS(fs->super, groups);
2453         last_start = 0;
2454         for (grp = 0; grp < flex_groups; grp++) {
2455                 overhead = calc_group_overhead(fs, grp, old_desc_blocks);
2456
2457                 /*
2458                  * we want to keep track of how much data we can store in
2459                  * the groups leading up to the last group so we can determine
2460                  * how big the last group needs to be
2461                  */
2462                 if (grp < (groups - 1))
2463                         last_start += EXT2_BLOCKS_PER_GROUP(fs->super) -
2464                                 overhead;
2465
2466                 if (data_blocks > overhead)
2467                         data_blocks -= overhead;
2468                 else
2469                         data_blocks = 0;
2470         }
2471 #ifdef RESIZE2FS_DEBUG
2472         if (flags & RESIZE_DEBUG_MIN_CALC)
2473                 printf("With %d group(s), we have %llu blocks available.\n",
2474                        groups, data_blocks);
2475 #endif
2476
2477         /*
2478          * if we need more group descriptors in order to accomodate our data
2479          * then we need to add them here
2480          */
2481         blks_needed = data_needed;
2482         while (blks_needed > data_blocks) {
2483                 blk64_t remainder = blks_needed - data_blocks;
2484                 dgrp_t extra_grps;
2485
2486                 /* figure out how many more groups we need for the data */
2487                 extra_grps = ext2fs_div64_ceil(remainder,
2488                                                EXT2_BLOCKS_PER_GROUP(fs->super));
2489
2490                 data_blocks += EXT2_GROUPS_TO_BLOCKS(fs->super, extra_grps);
2491
2492                 /* ok we have to account for the last group */
2493                 overhead = calc_group_overhead(fs, groups-1, old_desc_blocks);
2494                 last_start += EXT2_BLOCKS_PER_GROUP(fs->super) - overhead;
2495
2496                 grp = flex_groups;
2497                 groups += extra_grps;
2498                 if (!(fs->super->s_feature_incompat &
2499                       EXT4_FEATURE_INCOMPAT_FLEX_BG))
2500                         flex_groups = groups;
2501                 else if (groups > flex_groups) {
2502                         dgrp_t r = groups & (flexbg_size - 1);
2503
2504                         flex_groups = groups + flexbg_size - r;
2505                         if (flex_groups > fs->group_desc_count)
2506                                 flex_groups = fs->group_desc_count;
2507                 }
2508
2509                 for (; grp < flex_groups; grp++) {
2510                         overhead = calc_group_overhead(fs, grp,
2511                                                        old_desc_blocks);
2512
2513                         /*
2514                          * again, we need to see how much data we cram into
2515                          * all of the groups leading up to the last group
2516                          */
2517                         if (grp < groups - 1)
2518                                 last_start += EXT2_BLOCKS_PER_GROUP(fs->super)
2519                                         - overhead;
2520
2521                         data_blocks -= overhead;
2522                 }
2523
2524 #ifdef RESIZE2FS_DEBUG
2525                 if (flags & RESIZE_DEBUG_MIN_CALC)
2526                         printf("Added %d extra group(s), "
2527                                "blks_needed %llu, data_blocks %llu, "
2528                                "last_start %llu\n", extra_grps, blks_needed,
2529                                data_blocks, last_start);
2530 #endif
2531         }
2532
2533         /* now for the fun voodoo */
2534         grp = groups - 1;
2535         if ((fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_FLEX_BG) &&
2536             (grp & ~(flexbg_size - 1)) == 0)
2537                 grp = grp & ~(flexbg_size - 1);
2538         overhead = 0;
2539         for (; grp < flex_groups; grp++)
2540                 overhead += calc_group_overhead(fs, grp, old_desc_blocks);
2541
2542 #ifdef RESIZE2FS_DEBUG
2543         if (flags & RESIZE_DEBUG_MIN_CALC)
2544                 printf("Last group's overhead is %llu\n", overhead);
2545 #endif
2546
2547         /*
2548          * if this is the case then the last group is going to have data in it
2549          * so we need to adjust the size of the last group accordingly
2550          */
2551         if (last_start < blks_needed) {
2552                 blk64_t remainder = blks_needed - last_start;
2553
2554 #ifdef RESIZE2FS_DEBUG
2555                 if (flags & RESIZE_DEBUG_MIN_CALC)
2556                         printf("Need %llu data blocks in last group\n",
2557                                remainder);
2558 #endif
2559                 /*
2560                  * 50 is a magic number that mkfs/resize uses to see if its
2561                  * even worth making/resizing the fs.  basically you need to
2562                  * have at least 50 blocks in addition to the blocks needed
2563                  * for the metadata in the last group
2564                  */
2565                 if (remainder > 50)
2566                         overhead += remainder;
2567                 else
2568                         overhead += 50;
2569         } else
2570                 overhead += 50;
2571
2572         overhead += fs->super->s_first_data_block;
2573 #ifdef RESIZE2FS_DEBUG
2574         if (flags & RESIZE_DEBUG_MIN_CALC)
2575                 printf("Final size of last group is %lld\n", overhead);
2576 #endif
2577
2578         /* Add extra slack for bigalloc file systems */
2579         if (EXT2FS_CLUSTER_RATIO(fs) > 1)
2580                 overhead += EXT2FS_CLUSTER_RATIO(fs) * 2;
2581
2582         /*
2583          * since our last group doesn't have to be BLOCKS_PER_GROUP
2584          * large, we only do groups-1, and then add the number of
2585          * blocks needed to handle the group descriptor metadata+data
2586          * that we need
2587          */
2588         blks_needed = EXT2_GROUPS_TO_BLOCKS(fs->super, groups - 1);
2589         blks_needed += overhead;
2590
2591         /*
2592          * Make sure blks_needed covers the end of the inode table in
2593          * the last block group.
2594          */
2595         overhead = ext2fs_inode_table_loc(fs, groups-1) +
2596                 fs->inode_blocks_per_group;
2597         if (blks_needed < overhead)
2598                 blks_needed = overhead;
2599
2600 #ifdef RESIZE2FS_DEBUG
2601         if (flags & RESIZE_DEBUG_MIN_CALC)
2602                 printf("Estimated blocks needed: %llu\n", blks_needed);
2603 #endif
2604
2605         /*
2606          * If at this point we've already added up more "needed" than
2607          * the current size, just return current size as minimum.
2608          */
2609         if (blks_needed >= ext2fs_blocks_count(fs->super))
2610                 return ext2fs_blocks_count(fs->super);
2611         /*
2612          * We need to reserve a few extra blocks if extents are
2613          * enabled, in case we need to grow the extent tree.  The more
2614          * we shrink the file system, the more space we need.
2615          *
2616          * The absolute worst case is every single data block is in
2617          * the part of the file system that needs to be evacuated,
2618          * with each data block needs to be in its own extent, and
2619          * with each inode needing at least one extent block.
2620          */
2621         if (fs->super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_EXTENTS) {
2622                 blk64_t safe_margin = (ext2fs_blocks_count(fs->super) -
2623                                        blks_needed)/500;
2624                 unsigned int exts_per_blk = (fs->blocksize /
2625                                              sizeof(struct ext3_extent)) - 1;
2626                 blk64_t worst_case = ((data_needed + exts_per_blk - 1) /
2627                                       exts_per_blk);
2628
2629                 if (worst_case < inode_count)
2630                         worst_case = inode_count;
2631
2632                 if (safe_margin > worst_case)
2633                         safe_margin = worst_case;
2634
2635 #ifdef RESIZE2FS_DEBUG
2636                 if (flags & RESIZE_DEBUG_MIN_CALC)
2637                         printf("Extents safety margin: %llu\n", safe_margin);
2638 #endif
2639                 blks_needed += safe_margin;
2640         }
2641
2642         return blks_needed;
2643 }