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 (!(EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 244                                          EXT4_FEATURE_RO_COMPAT_GDT_CSUM)))
 245                 return;
 246
 247         for (g=0; g < fs->group_desc_count; g++) {
 248                 if (!(ext2fs_bg_flags_test(fs, g, EXT2_BG_BLOCK_UNINIT)))
 249                         continue;
 250
 251                 blk = ext2fs_group_first_block2(fs, g);
 252                 lblk = ext2fs_group_last_block2(fs, g);
 253                 ext2fs_unmark_block_bitmap_range2(fs->block_map, blk,
 254                                                   lblk - blk + 1);
 255
 256                 ext2fs_reserve_super_and_bgd(fs, g, fs->block_map);
 257                 ext2fs_mark_block_bitmap2(fs->block_map,
 258                                           ext2fs_block_bitmap_loc(fs, g));
 259                 ext2fs_mark_block_bitmap2(fs->block_map,
 260                                           ext2fs_inode_bitmap_loc(fs, g));
 261                 for (i = 0, blk = ext2fs_inode_table_loc(fs, g);
 262                      i < (unsigned int) fs->inode_blocks_per_group;
 263                      i++, blk++)
 264                         ext2fs_mark_block_bitmap2(fs->block_map, blk);
 265         }
 266 }
 267
 268 /* --------------------------------------------------------------------
 269  *
 270  * Resize processing, phase 1.
 271  *
 272  * In this phase we adjust the in-memory superblock information, and
 273  * initialize any new parts of the inode table.  The new parts of the
 274  * inode table are created in virgin disk space, so we can abort here
 275  * without any side effects.
 276  * --------------------------------------------------------------------
 277  */
 278
 279 /*
 280  * If the group descriptor's bitmap and inode table blocks are valid,
 281  * release them in the new filesystem data structure, and mark them as
 282  * reserved so the old inode table blocks don't get overwritten.
 283  */
 284 static errcode_t free_gdp_blocks(ext2_filsys fs,
 285                                  ext2fs_block_bitmap reserve_blocks,
 286                                  ext2_filsys old_fs,
 287                                  dgrp_t group)
 288 {
 289         blk64_t blk;
 290         int     j;
 291         dgrp_t  i;
 292         ext2fs_block_bitmap bg_map = NULL;
 293         errcode_t retval = 0;
 294         dgrp_t count = old_fs->group_desc_count - fs->group_desc_count;
 295
 296         /* If bigalloc, don't free metadata living in the same cluster */
 297         if (EXT2FS_CLUSTER_RATIO(fs) > 1) {
 298                 retval = ext2fs_allocate_block_bitmap(fs, "bgdata", &bg_map);
 299                 if (retval)
 300                         goto out;
 301
 302                 retval = mark_table_blocks(fs, bg_map);
 303                 if (retval)
 304                         goto out;
 305         }
 306
 307         for (i = group; i < group + count; i++) {
 308                 blk = ext2fs_block_bitmap_loc(old_fs, i);
 309                 if (blk &&
 310                     (blk < ext2fs_blocks_count(fs->super)) &&
 311                     !(bg_map && ext2fs_test_block_bitmap2(bg_map, blk))) {
 312                         ext2fs_block_alloc_stats2(fs, blk, -1);
 313                         ext2fs_mark_block_bitmap2(reserve_blocks, blk);
 314                 }
 315
 316                 blk = ext2fs_inode_bitmap_loc(old_fs, i);
 317                 if (blk &&
 318                     (blk < ext2fs_blocks_count(fs->super)) &&
 319                     !(bg_map && ext2fs_test_block_bitmap2(bg_map, blk))) {
 320                         ext2fs_block_alloc_stats2(fs, blk, -1);
 321                         ext2fs_mark_block_bitmap2(reserve_blocks, blk);
 322                 }
 323
 324                 blk = ext2fs_inode_table_loc(old_fs, i);
 325                 for (j = 0;
 326                      j < fs->inode_blocks_per_group; j++, blk++) {
 327                         if (blk >= ext2fs_blocks_count(fs->super) ||
 328                             (bg_map && ext2fs_test_block_bitmap2(bg_map, blk)))
 329                                 continue;
 330                         ext2fs_block_alloc_stats2(fs, blk, -1);
 331                         ext2fs_mark_block_bitmap2(reserve_blocks, blk);
 332                 }
 333         }
 334
 335 out:
 336         if (bg_map)
 337                 ext2fs_free_block_bitmap(bg_map);
 338         return retval;
 339 }
 340
 341 /*
 342  * This routine is shared by the online and offline resize routines.
 343  * All of the information which is adjusted in memory is done here.
 344  */
 345 errcode_t adjust_fs_info(ext2_filsys fs, ext2_filsys old_fs,
 346                          ext2fs_block_bitmap reserve_blocks, blk64_t new_size)
 347 {
 348         errcode_t       retval;
 349         blk64_t         overhead = 0;
 350         blk64_t         rem;
 351         blk64_t         blk, group_block;
 352         blk64_t         real_end;
 353         blk64_t         old_numblocks, numblocks, adjblocks;
 354         unsigned long   i, j, old_desc_blocks;
 355         unsigned int    meta_bg, meta_bg_size;
 356         int             has_super, csum_flag;
 357         unsigned long long new_inodes;  /* u64 to check for overflow */
 358         double          percent;
 359
 360         ext2fs_blocks_count_set(fs->super, new_size);
 361
 362 retry:
 363         fs->group_desc_count = ext2fs_div64_ceil(ext2fs_blocks_count(fs->super) -
 364                                        fs->super->s_first_data_block,
 365                                        EXT2_BLOCKS_PER_GROUP(fs->super));
 366         if (fs->group_desc_count == 0)
 367                 return EXT2_ET_TOOSMALL;
 368         fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count,
 369                                           EXT2_DESC_PER_BLOCK(fs->super));
 370
 371         /*
 372          * Overhead is the number of bookkeeping blocks per group.  It
 373          * includes the superblock backup, the group descriptor
 374          * backups, the inode bitmap, the block bitmap, and the inode
 375          * table.
 376          */
 377         overhead = (int) (2 + fs->inode_blocks_per_group);
 378
 379         if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1))
 380                 overhead += 1 + fs->desc_blocks +
 381                         fs->super->s_reserved_gdt_blocks;
 382
 383         /*
 384          * See if the last group is big enough to support the
 385          * necessary data structures.  If not, we need to get rid of
 386          * it.
 387          */
 388         rem = (ext2fs_blocks_count(fs->super) - fs->super->s_first_data_block) %
 389                 fs->super->s_blocks_per_group;
 390         if ((fs->group_desc_count == 1) && rem && (rem < overhead))
 391                 return EXT2_ET_TOOSMALL;
 392         if ((fs->group_desc_count > 1) && rem && (rem < overhead+50)) {
 393                 ext2fs_blocks_count_set(fs->super,
 394                                         ext2fs_blocks_count(fs->super) - rem);
 395                 goto retry;
 396         }
 397         /*
 398          * Adjust the number of inodes
 399          */
 400         new_inodes =(unsigned long long) fs->super->s_inodes_per_group * fs->group_desc_count;
 401         if (new_inodes > ~0U) {
 402                 fprintf(stderr, _("inodes (%llu) must be less than %u"),
 403                                    new_inodes, ~0U);
 404                 return EXT2_ET_TOO_MANY_INODES;
 405         }
 406         fs->super->s_inodes_count = fs->super->s_inodes_per_group *
 407                 fs->group_desc_count;
 408
 409         /*
 410          * Adjust the number of free blocks
 411          */
 412         blk = ext2fs_blocks_count(old_fs->super);
 413         if (blk > ext2fs_blocks_count(fs->super))
 414                 ext2fs_free_blocks_count_set(fs->super,
 415                         ext2fs_free_blocks_count(fs->super) -
 416                         (blk - ext2fs_blocks_count(fs->super)));
 417         else
 418                 ext2fs_free_blocks_count_set(fs->super,
 419                         ext2fs_free_blocks_count(fs->super) +
 420                         (ext2fs_blocks_count(fs->super) - blk));
 421
 422         /*
 423          * Adjust the number of reserved blocks
 424          */
 425         percent = (ext2fs_r_blocks_count(old_fs->super) * 100.0) /
 426                 ext2fs_blocks_count(old_fs->super);
 427         ext2fs_r_blocks_count_set(fs->super,
 428                                   (percent * ext2fs_blocks_count(fs->super) /
 429                                    100.0));
 430
 431         /*
 432          * Adjust the bitmaps for size
 433          */
 434         retval = ext2fs_resize_inode_bitmap2(fs->super->s_inodes_count,
 435                                             fs->super->s_inodes_count,
 436                                             fs->inode_map);
 437         if (retval) goto errout;
 438
 439         real_end = EXT2_GROUPS_TO_BLOCKS(fs->super, fs->group_desc_count) - 1 +
 440                 fs->super->s_first_data_block;
 441         retval = ext2fs_resize_block_bitmap2(new_size - 1,
 442                                              real_end, fs->block_map);
 443         if (retval) goto errout;
 444
 445         /*
 446          * If we are growing the file system, also grow the size of
 447          * the reserve_blocks bitmap
 448          */
 449         if (reserve_blocks && new_size > ext2fs_blocks_count(old_fs->super)) {
 450                 retval = ext2fs_resize_block_bitmap2(new_size - 1,
 451                                                      real_end, reserve_blocks);
 452                 if (retval) goto errout;
 453         }
 454
 455         /*
 456          * Reallocate the group descriptors as necessary.
 457          */
 458         if (old_fs->desc_blocks != fs->desc_blocks) {
 459                 retval = ext2fs_resize_mem(old_fs->desc_blocks *
 460                                            fs->blocksize,
 461                                            fs->desc_blocks * fs->blocksize,
 462                                            &fs->group_desc);
 463                 if (retval)
 464                         goto errout;
 465                 if (fs->desc_blocks > old_fs->desc_blocks)
 466                         memset((char *) fs->group_desc +
 467                                (old_fs->desc_blocks * fs->blocksize), 0,
 468                                (fs->desc_blocks - old_fs->desc_blocks) *
 469                                fs->blocksize);
 470         }
 471
 472         /*
 473          * If the resize_inode feature is set, and we are changing the
 474          * number of descriptor blocks, then adjust
 475          * s_reserved_gdt_blocks if possible to avoid needing to move
 476          * the inode table either now or in the future.
 477          */
 478         if ((fs->super->s_feature_compat &
 479              EXT2_FEATURE_COMPAT_RESIZE_INODE) &&
 480             (old_fs->desc_blocks != fs->desc_blocks)) {
 481                 int new;
 482
 483                 new = ((int) fs->super->s_reserved_gdt_blocks) +
 484                         (old_fs->desc_blocks - fs->desc_blocks);
 485                 if (new < 0)
 486                         new = 0;
 487                 if (new > (int) fs->blocksize/4)
 488                         new = fs->blocksize/4;
 489                 fs->super->s_reserved_gdt_blocks = new;
 490         }
 491
 492         if ((fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) &&
 493             (fs->super->s_first_meta_bg > fs->desc_blocks)) {
 494                 fs->super->s_feature_incompat &=
 495                         ~EXT2_FEATURE_INCOMPAT_META_BG;
 496                 fs->super->s_first_meta_bg = 0;
 497         }
 498
 499         /*
 500          * Update the location of the backup superblocks if the
 501          * sparse_super2 feature is enabled.
 502          */
 503         if (fs->super->s_feature_compat & EXT4_FEATURE_COMPAT_SPARSE_SUPER2) {
 504                 dgrp_t last_bg = fs->group_desc_count - 1;
 505                 dgrp_t old_last_bg = old_fs->group_desc_count - 1;
 506
 507                 if (last_bg > old_last_bg) {
 508                         if (old_fs->group_desc_count == 1)
 509                                 fs->super->s_backup_bgs[0] = 1;
 510                         if (old_fs->group_desc_count == 1 &&
 511                             fs->super->s_backup_bgs[0])
 512                                 fs->super->s_backup_bgs[0] = last_bg;
 513                         else if (fs->super->s_backup_bgs[1])
 514                                 fs->super->s_backup_bgs[1] = last_bg;
 515                 } else if (last_bg < old_last_bg) {
 516                         if (fs->super->s_backup_bgs[0] > last_bg)
 517                                 fs->super->s_backup_bgs[0] = 0;
 518                         if (fs->super->s_backup_bgs[1] > last_bg)
 519                                 fs->super->s_backup_bgs[1] = 0;
 520                         if (last_bg > 1 &&
 521                             old_fs->super->s_backup_bgs[1] == old_last_bg)
 522                                 fs->super->s_backup_bgs[1] = last_bg;
 523                 }
 524         }
 525
 526         /*
 527          * If we are shrinking the number of block groups, we're done
 528          * and can exit now.
 529          */
 530         if (old_fs->group_desc_count > fs->group_desc_count) {
 531                 /*
 532                  * Check the block groups that we are chopping off
 533                  * and free any blocks associated with their metadata
 534                  */
 535                 retval = free_gdp_blocks(fs, reserve_blocks, old_fs,
 536                                          fs->group_desc_count);
 537                 goto errout;
 538         }
 539
 540         /*
 541          * Fix the count of the last (old) block group
 542          */
 543         old_numblocks = (ext2fs_blocks_count(old_fs->super) -
 544                          old_fs->super->s_first_data_block) %
 545                                  old_fs->super->s_blocks_per_group;
 546         if (!old_numblocks)
 547                 old_numblocks = old_fs->super->s_blocks_per_group;
 548         if (old_fs->group_desc_count == fs->group_desc_count) {
 549                 numblocks = (ext2fs_blocks_count(fs->super) -
 550                              fs->super->s_first_data_block) %
 551                         fs->super->s_blocks_per_group;
 552                 if (!numblocks)
 553                         numblocks = fs->super->s_blocks_per_group;
 554         } else
 555                 numblocks = fs->super->s_blocks_per_group;
 556         i = old_fs->group_desc_count - 1;
 557         ext2fs_bg_free_blocks_count_set(fs, i, ext2fs_bg_free_blocks_count(fs, i) + (numblocks - old_numblocks));
 558         ext2fs_group_desc_csum_set(fs, i);
 559
 560         /*
 561          * If the number of block groups is staying the same, we're
 562          * done and can exit now.  (If the number block groups is
 563          * shrinking, we had exited earlier.)
 564          */
 565         if (old_fs->group_desc_count >= fs->group_desc_count) {
 566                 retval = 0;
 567                 goto errout;
 568         }
 569
 570         /*
 571          * Initialize the new block group descriptors
 572          */
 573         group_block = ext2fs_group_first_block2(fs,
 574                                                 old_fs->group_desc_count);
 575         csum_flag = EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 576                                                EXT4_FEATURE_RO_COMPAT_GDT_CSUM);
 577         if (access("/sys/fs/ext4/features/lazy_itable_init", F_OK) == 0)
 578                 lazy_itable_init = 1;
 579         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
 580                 old_desc_blocks = fs->super->s_first_meta_bg;
 581         else
 582                 old_desc_blocks = fs->desc_blocks +
 583                         fs->super->s_reserved_gdt_blocks;
 584
 585         /*
 586          * If we changed the number of block_group descriptor blocks,
 587          * we need to make sure they are all marked as reserved in the
 588          * file systems's block allocation map.
 589          */
 590         for (i = 0; i < old_fs->group_desc_count; i++)
 591                 ext2fs_reserve_super_and_bgd(fs, i, fs->block_map);
 592
 593         for (i = old_fs->group_desc_count;
 594              i < fs->group_desc_count; i++) {
 595                 memset(ext2fs_group_desc(fs, fs->group_desc, i), 0,
 596                        sizeof(struct ext2_group_desc));
 597                 adjblocks = 0;
 598
 599                 ext2fs_bg_flags_zap(fs, i);
 600                 if (csum_flag) {
 601                         ext2fs_bg_flags_set(fs, i, EXT2_BG_INODE_UNINIT);
 602                         if (!lazy_itable_init)
 603                                 ext2fs_bg_flags_set(fs, i,
 604                                                     EXT2_BG_INODE_ZEROED);
 605                         ext2fs_bg_itable_unused_set(fs, i,
 606                                         fs->super->s_inodes_per_group);
 607                 }
 608
 609                 numblocks = ext2fs_group_blocks_count(fs, i);
 610                 if ((i < fs->group_desc_count - 1) && csum_flag)
 611                         ext2fs_bg_flags_set(fs, i, EXT2_BG_BLOCK_UNINIT);
 612
 613                 has_super = ext2fs_bg_has_super(fs, i);
 614                 if (has_super) {
 615                         ext2fs_block_alloc_stats2(fs, group_block, +1);
 616                         adjblocks++;
 617                 }
 618                 meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
 619                 meta_bg = i / meta_bg_size;
 620                 if (!(fs->super->s_feature_incompat &
 621                       EXT2_FEATURE_INCOMPAT_META_BG) ||
 622                     (meta_bg < fs->super->s_first_meta_bg)) {
 623                         if (has_super) {
 624                                 for (j=0; j < old_desc_blocks; j++)
 625                                         ext2fs_block_alloc_stats2(fs,
 626                                                  group_block + 1 + j, +1);
 627                                 adjblocks += old_desc_blocks;
 628                         }
 629                 } else {
 630                         if (has_super)
 631                                 has_super = 1;
 632                         if (((i % meta_bg_size) == 0) ||
 633                             ((i % meta_bg_size) == 1) ||
 634                             ((i % meta_bg_size) == (meta_bg_size-1)))
 635                                 ext2fs_block_alloc_stats2(fs,
 636                                                  group_block + has_super, +1);
 637                 }
 638
 639                 adjblocks += 2 + fs->inode_blocks_per_group;
 640
 641                 numblocks -= adjblocks;
 642                 ext2fs_free_blocks_count_set(fs->super,
 643                              ext2fs_free_blocks_count(fs->super) - adjblocks);
 644                 fs->super->s_free_inodes_count +=
 645                         fs->super->s_inodes_per_group;
 646                 ext2fs_bg_free_blocks_count_set(fs, i, numblocks);
 647                 ext2fs_bg_free_inodes_count_set(fs, i,
 648                                                 fs->super->s_inodes_per_group);
 649                 ext2fs_bg_used_dirs_count_set(fs, i, 0);
 650                 ext2fs_group_desc_csum_set(fs, i);
 651
 652                 retval = ext2fs_allocate_group_table(fs, i, 0);
 653                 if (retval) goto errout;
 654
 655                 group_block += fs->super->s_blocks_per_group;
 656         }
 657         retval = 0;
 658
 659         /*
 660          * Mark all of the metadata blocks as reserved so they won't
 661          * get allocated by the call to ext2fs_allocate_group_table()
 662          * in blocks_to_move(), where we allocate new blocks to
 663          * replace those allocation bitmap and inode table blocks
 664          * which have to get relocated to make space for an increased
 665          * number of the block group descriptors.
 666          */
 667         if (reserve_blocks)
 668                 mark_table_blocks(fs, reserve_blocks);
 669
 670 errout:
 671         return (retval);
 672 }
 673
 674 /*
 675  * This routine adjusts the superblock and other data structures, both
 676  * in disk as well as in memory...
 677  */
 678 static errcode_t adjust_superblock(ext2_resize_t rfs, blk64_t new_size)
 679 {
 680         ext2_filsys     fs = rfs->new_fs;
 681         int             adj = 0;
 682         errcode_t       retval;
 683         blk64_t         group_block;
 684         unsigned long   i;
 685         unsigned long   max_group;
 686
 687         ext2fs_mark_super_dirty(fs);
 688         ext2fs_mark_bb_dirty(fs);
 689         ext2fs_mark_ib_dirty(fs);
 690
 691         retval = ext2fs_allocate_block_bitmap(fs, _("reserved blocks"),
 692                                               &rfs->reserve_blocks);
 693         if (retval)
 694                 return retval;
 695
 696         retval = adjust_fs_info(fs, rfs->old_fs, rfs->reserve_blocks, new_size);
 697         if (retval)
 698                 goto errout;
 699
 700         /*
 701          * Check to make sure there are enough inodes
 702          */
 703         if ((rfs->old_fs->super->s_inodes_count -
 704              rfs->old_fs->super->s_free_inodes_count) >
 705             rfs->new_fs->super->s_inodes_count) {
 706                 retval = ENOSPC;
 707                 goto errout;
 708         }
 709
 710         /*
 711          * If we are shrinking the number block groups, we're done and
 712          * can exit now.
 713          */
 714         if (rfs->old_fs->group_desc_count > fs->group_desc_count) {
 715                 retval = 0;
 716                 goto errout;
 717         }
 718
 719         /*
 720          * If the number of block groups is staying the same, we're
 721          * done and can exit now.  (If the number block groups is
 722          * shrinking, we had exited earlier.)
 723          */
 724         if (rfs->old_fs->group_desc_count >= fs->group_desc_count) {
 725                 retval = 0;
 726                 goto errout;
 727         }
 728
 729         /*
 730          * If we are using uninit_bg (aka GDT_CSUM) and the kernel
 731          * supports lazy inode initialization, we can skip
 732          * initializing the inode table.
 733          */
 734         if (lazy_itable_init &&
 735             EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 736                                        EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
 737                 retval = 0;
 738                 goto errout;
 739         }
 740
 741         /*
 742          * Initialize the inode table
 743          */
 744         retval = ext2fs_get_array(fs->blocksize, fs->inode_blocks_per_group,
 745                                 &rfs->itable_buf);
 746         if (retval)
 747                 goto errout;
 748
 749         memset(rfs->itable_buf, 0, fs->blocksize * fs->inode_blocks_per_group);
 750         group_block = ext2fs_group_first_block2(fs,
 751                                                 rfs->old_fs->group_desc_count);
 752         adj = rfs->old_fs->group_desc_count;
 753         max_group = fs->group_desc_count - adj;
 754         if (rfs->progress) {
 755                 retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
 756                                        0, max_group);
 757                 if (retval)
 758                         goto errout;
 759         }
 760         for (i = rfs->old_fs->group_desc_count;
 761              i < fs->group_desc_count; i++) {
 762                 /*
 763                  * Write out the new inode table
 764                  */
 765                 retval = io_channel_write_blk64(fs->io,
 766                                                 ext2fs_inode_table_loc(fs, i),
 767                                                 fs->inode_blocks_per_group,
 768                                                 rfs->itable_buf);
 769                 if (retval) goto errout;
 770
 771                 io_channel_flush(fs->io);
 772                 if (rfs->progress) {
 773                         retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
 774                                                i - adj + 1, max_group);
 775                         if (retval)
 776                                 goto errout;
 777                 }
 778                 group_block += fs->super->s_blocks_per_group;
 779         }
 780         io_channel_flush(fs->io);
 781         retval = 0;
 782
 783 errout:
 784         return retval;
 785 }
 786
 787 /* --------------------------------------------------------------------
 788  *
 789  * Resize processing, phase 2.
 790  *
 791  * In this phase we adjust determine which blocks need to be moved, in
 792  * blocks_to_move().  We then copy the blocks to their ultimate new
 793  * destinations using block_mover().  Since we are copying blocks to
 794  * their new locations, again during this pass we can abort without
 795  * any problems.
 796  * --------------------------------------------------------------------
 797  */
 798
 799 /*
 800  * This helper function creates a block bitmap with all of the
 801  * filesystem meta-data blocks.
 802  */
 803 static errcode_t mark_table_blocks(ext2_filsys fs,
 804                                    ext2fs_block_bitmap bmap)
 805 {
 806         dgrp_t                  i;
 807         blk64_t                 blk;
 808
 809         for (i = 0; i < fs->group_desc_count; i++) {
 810                 ext2fs_reserve_super_and_bgd(fs, i, bmap);
 811
 812                 /*
 813                  * Mark the blocks used for the inode table
 814                  */
 815                 blk = ext2fs_inode_table_loc(fs, i);
 816                 if (blk)
 817                         ext2fs_mark_block_bitmap_range2(bmap, blk,
 818                                                 fs->inode_blocks_per_group);
 819
 820                 /*
 821                  * Mark block used for the block bitmap
 822                  */
 823                 blk = ext2fs_block_bitmap_loc(fs, i);
 824                 if (blk)
 825                         ext2fs_mark_block_bitmap2(bmap, blk);
 826
 827                 /*
 828                  * Mark block used for the inode bitmap
 829                  */
 830                 blk = ext2fs_inode_bitmap_loc(fs, i);
 831                 if (blk)
 832                         ext2fs_mark_block_bitmap2(bmap, blk);
 833         }
 834         return 0;
 835 }
 836
 837 /*
 838  * This function checks to see if a particular block (either a
 839  * superblock or a block group descriptor) overlaps with an inode or
 840  * block bitmap block, or with the inode table.
 841  */
 842 static void mark_fs_metablock(ext2_resize_t rfs,
 843                               ext2fs_block_bitmap meta_bmap,
 844                               int group, blk64_t blk)
 845 {
 846         ext2_filsys     fs = rfs->new_fs;
 847
 848         ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
 849         ext2fs_block_alloc_stats2(fs, blk, +1);
 850
 851         /*
 852          * Check to see if we overlap with the inode or block bitmap,
 853          * or the inode tables.  If not, and the block is in use, then
 854          * mark it as a block to be moved.
 855          */
 856         if (IS_BLOCK_BM(fs, group, blk)) {
 857                 ext2fs_block_bitmap_loc_set(fs, group, 0);
 858                 rfs->needed_blocks++;
 859                 return;
 860         }
 861         if (IS_INODE_BM(fs, group, blk)) {
 862                 ext2fs_inode_bitmap_loc_set(fs, group, 0);
 863                 rfs->needed_blocks++;
 864                 return;
 865         }
 866         if (IS_INODE_TB(fs, group, blk)) {
 867                 ext2fs_inode_table_loc_set(fs, group, 0);
 868                 rfs->needed_blocks++;
 869                 return;
 870         }
 871         if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_FLEX_BG) {
 872                 dgrp_t i;
 873
 874                 for (i=0; i < rfs->old_fs->group_desc_count; i++) {
 875                         if (IS_BLOCK_BM(fs, i, blk)) {
 876                                 ext2fs_block_bitmap_loc_set(fs, i, 0);
 877                                 rfs->needed_blocks++;
 878                                 return;
 879                         }
 880                         if (IS_INODE_BM(fs, i, blk)) {
 881                                 ext2fs_inode_bitmap_loc_set(fs, i, 0);
 882                                 rfs->needed_blocks++;
 883                                 return;
 884                         }
 885                         if (IS_INODE_TB(fs, i, blk)) {
 886                                 ext2fs_inode_table_loc_set(fs, i, 0);
 887                                 rfs->needed_blocks++;
 888                                 return;
 889                         }
 890                 }
 891         }
 892         if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 893                                        EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
 894                    (ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT))) {
 895                 /*
 896                  * If the block bitmap is uninitialized, which means
 897                  * nothing other than standard metadata in use.
 898                  */
 899                 return;
 900         } else if (ext2fs_test_block_bitmap2(rfs->old_fs->block_map, blk) &&
 901                    !ext2fs_test_block_bitmap2(meta_bmap, blk)) {
 902                 ext2fs_mark_block_bitmap2(rfs->move_blocks, blk);
 903                 rfs->needed_blocks++;
 904         }
 905 }
 906
 907
 908 /*
 909  * This routine marks and unmarks reserved blocks in the new block
 910  * bitmap.  It also determines which blocks need to be moved and
 911  * places this information into the move_blocks bitmap.
 912  */
 913 static errcode_t blocks_to_move(ext2_resize_t rfs)
 914 {
 915         int             j, has_super;
 916         dgrp_t          i, max_groups, g;
 917         blk64_t         blk, group_blk;
 918         blk64_t         old_blocks, new_blocks, group_end, cluster_freed;
 919         blk64_t         new_size;
 920         unsigned int    meta_bg, meta_bg_size;
 921         errcode_t       retval;
 922         ext2_filsys     fs, old_fs;
 923         ext2fs_block_bitmap     meta_bmap, new_meta_bmap = NULL;
 924         int             flex_bg;
 925
 926         fs = rfs->new_fs;
 927         old_fs = rfs->old_fs;
 928         if (ext2fs_blocks_count(old_fs->super) > ext2fs_blocks_count(fs->super))
 929                 fs = rfs->old_fs;
 930
 931         retval = ext2fs_allocate_block_bitmap(fs, _("blocks to be moved"),
 932                                               &rfs->move_blocks);
 933         if (retval)
 934                 return retval;
 935
 936         retval = ext2fs_allocate_block_bitmap(fs, _("meta-data blocks"),
 937                                               &meta_bmap);
 938         if (retval)
 939                 return retval;
 940
 941         retval = mark_table_blocks(old_fs, meta_bmap);
 942         if (retval)
 943                 return retval;
 944
 945         fs = rfs->new_fs;
 946
 947         /*
 948          * If we're shrinking the filesystem, we need to move any
 949          * group's metadata blocks (either allocation bitmaps or the
 950          * inode table) which are beyond the end of the new
 951          * filesystem.
 952          */
 953         new_size = ext2fs_blocks_count(fs->super);
 954         if (new_size < ext2fs_blocks_count(old_fs->super)) {
 955                 for (g = 0; g < fs->group_desc_count; g++) {
 956                         int realloc = 0;
 957                         /*
 958                          * ext2fs_allocate_group_table will re-allocate any
 959                          * metadata blocks whose location is set to zero.
 960                          */
 961                         if (ext2fs_block_bitmap_loc(fs, g) >= new_size) {
 962                                 ext2fs_block_bitmap_loc_set(fs, g, 0);
 963                                 realloc = 1;
 964                         }
 965                         if (ext2fs_inode_bitmap_loc(fs, g) >= new_size) {
 966                                 ext2fs_inode_bitmap_loc_set(fs, g, 0);
 967                                 realloc = 1;
 968                         }
 969                         if ((ext2fs_inode_table_loc(fs, g) +
 970                              fs->inode_blocks_per_group) > new_size) {
 971                                 ext2fs_inode_table_loc_set(fs, g, 0);
 972                                 realloc = 1;
 973                         }
 974
 975                         if (realloc) {
 976                                 retval = ext2fs_allocate_group_table(fs, g, 0);
 977                                 if (retval)
 978                                         return retval;
 979                         }
 980                 }
 981         }
 982
 983         /*
 984          * If we're shrinking the filesystem, we need to move all of
 985          * the blocks that don't fit any more
 986          */
 987         for (blk = ext2fs_blocks_count(fs->super);
 988              blk < ext2fs_blocks_count(old_fs->super); blk++) {
 989                 g = ext2fs_group_of_blk2(fs, blk);
 990                 if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 991                                                EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
 992                     ext2fs_bg_flags_test(old_fs, g, EXT2_BG_BLOCK_UNINIT)) {
 993                         /*
 994                          * The block bitmap is uninitialized, so skip
 995                          * to the next block group.
 996                          */
 997                         blk = ext2fs_group_first_block2(fs, g+1) - 1;
 998                         continue;
 999                 }
1000                 if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
1001                     !ext2fs_test_block_bitmap2(meta_bmap, blk)) {
1002                         ext2fs_mark_block_bitmap2(rfs->move_blocks, blk);
1003                         rfs->needed_blocks++;
1004                 }
1005                 ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
1006         }
1007
1008         if (old_fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
1009                 old_blocks = old_fs->super->s_first_meta_bg;
1010         else
1011                 old_blocks = old_fs->desc_blocks +
1012                         old_fs->super->s_reserved_gdt_blocks;
1013         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
1014                 new_blocks = fs->super->s_first_meta_bg;
1015         else
1016                 new_blocks = fs->desc_blocks + fs->super->s_reserved_gdt_blocks;
1017
1018         retval = reserve_sparse_super2_last_group(rfs, meta_bmap);
1019         if (retval)
1020                 goto errout;
1021
1022         if (old_blocks == new_blocks) {
1023                 retval = 0;
1024                 goto errout;
1025         }
1026
1027         max_groups = fs->group_desc_count;
1028         if (max_groups > old_fs->group_desc_count)
1029                 max_groups = old_fs->group_desc_count;
1030         group_blk = old_fs->super->s_first_data_block;
1031         /*
1032          * If we're reducing the number of descriptor blocks, this
1033          * makes life easy.  :-)   We just have to mark some extra
1034          * blocks as free.
1035          */
1036         if (old_blocks > new_blocks) {
1037                 if (EXT2FS_CLUSTER_RATIO(fs) > 1) {
1038                         retval = ext2fs_allocate_block_bitmap(fs,
1039                                                         _("new meta blocks"),
1040                                                         &new_meta_bmap);
1041                         if (retval)
1042                                 goto errout;
1043
1044                         retval = mark_table_blocks(fs, new_meta_bmap);
1045                         if (retval)
1046                                 goto errout;
1047                 }
1048
1049                 for (i = 0; i < max_groups; i++) {
1050                         if (!ext2fs_bg_has_super(fs, i)) {
1051                                 group_blk += fs->super->s_blocks_per_group;
1052                                 continue;
1053                         }
1054                         group_end = group_blk + 1 + old_blocks;
1055                         for (blk = group_blk + 1 + new_blocks;
1056                              blk < group_end;) {
1057                                 if (new_meta_bmap == NULL ||
1058                                     !ext2fs_test_block_bitmap2(new_meta_bmap,
1059                                                                blk)) {
1060                                         cluster_freed =
1061                                                 EXT2FS_CLUSTER_RATIO(fs) -
1062                                                 (blk &
1063                                                  EXT2FS_CLUSTER_MASK(fs));
1064                                         if (cluster_freed > group_end - blk)
1065                                                 cluster_freed = group_end - blk;
1066                                         ext2fs_block_alloc_stats2(fs, blk, -1);
1067                                         blk += EXT2FS_CLUSTER_RATIO(fs);
1068                                         rfs->needed_blocks -= cluster_freed;
1069                                         continue;
1070                                 }
1071                                 rfs->needed_blocks--;
1072                                 blk++;
1073                         }
1074                         group_blk += fs->super->s_blocks_per_group;
1075                 }
1076                 retval = 0;
1077                 goto errout;
1078         }
1079         /*
1080          * If we're increasing the number of descriptor blocks, life
1081          * gets interesting....
1082          */
1083         meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
1084         flex_bg = fs->super->s_feature_incompat &
1085                 EXT4_FEATURE_INCOMPAT_FLEX_BG;
1086         /* first reserve all of the existing fs meta blocks */
1087         for (i = 0; i < max_groups; i++) {
1088                 has_super = ext2fs_bg_has_super(fs, i);
1089                 if (has_super)
1090                         mark_fs_metablock(rfs, meta_bmap, i, group_blk);
1091
1092                 meta_bg = i / meta_bg_size;
1093                 if (!(fs->super->s_feature_incompat &
1094                       EXT2_FEATURE_INCOMPAT_META_BG) ||
1095                     (meta_bg < fs->super->s_first_meta_bg)) {
1096                         if (has_super) {
1097                                 for (blk = group_blk+1;
1098                                      blk < group_blk + 1 + new_blocks; blk++)
1099                                         mark_fs_metablock(rfs, meta_bmap,
1100                                                           i, blk);
1101                         }
1102                 } else {
1103                         if (has_super)
1104                                 has_super = 1;
1105                         if (((i % meta_bg_size) == 0) ||
1106                             ((i % meta_bg_size) == 1) ||
1107                             ((i % meta_bg_size) == (meta_bg_size-1)))
1108                                 mark_fs_metablock(rfs, meta_bmap, i,
1109                                                   group_blk + has_super);
1110                 }
1111
1112                 /*
1113                  * Reserve the existing meta blocks that we know
1114                  * aren't to be moved.
1115                  *
1116                  * For flex_bg file systems, in order to avoid
1117                  * overwriting fs metadata (especially inode table
1118                  * blocks) belonging to a different block group when
1119                  * we are relocating the inode tables, we need to
1120                  * reserve all existing fs metadata blocks.
1121                  */
1122                 if (ext2fs_block_bitmap_loc(fs, i))
1123                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
1124                                  ext2fs_block_bitmap_loc(fs, i));
1125                 else if (flex_bg && i < old_fs->group_desc_count)
1126                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
1127                                  ext2fs_block_bitmap_loc(old_fs, i));
1128
1129                 if (ext2fs_inode_bitmap_loc(fs, i))
1130                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
1131                                  ext2fs_inode_bitmap_loc(fs, i));
1132                 else if (flex_bg && i < old_fs->group_desc_count)
1133                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
1134                                  ext2fs_inode_bitmap_loc(old_fs, i));
1135
1136                 if (ext2fs_inode_table_loc(fs, i))
1137                         ext2fs_mark_block_bitmap_range2(rfs->reserve_blocks,
1138                                         ext2fs_inode_table_loc(fs, i),
1139                                         fs->inode_blocks_per_group);
1140                 else if (flex_bg && i < old_fs->group_desc_count)
1141                         ext2fs_mark_block_bitmap_range2(rfs->reserve_blocks,
1142                                         ext2fs_inode_table_loc(old_fs, i),
1143                                         old_fs->inode_blocks_per_group);
1144
1145                 group_blk += rfs->new_fs->super->s_blocks_per_group;
1146         }
1147
1148         /* Allocate the missing data structures */
1149         for (i = 0; i < max_groups; i++) {
1150                 if (ext2fs_inode_table_loc(fs, i) &&
1151                     ext2fs_inode_bitmap_loc(fs, i) &&
1152                     ext2fs_block_bitmap_loc(fs, i))
1153                         continue;
1154
1155                 retval = ext2fs_allocate_group_table(fs, i,
1156                                                      rfs->reserve_blocks);
1157                 if (retval)
1158                         goto errout;
1159
1160                 /*
1161                  * For those structures that have changed, we need to
1162                  * do bookkeepping.
1163                  */
1164                 if (ext2fs_block_bitmap_loc(old_fs, i) !=
1165                     (blk = ext2fs_block_bitmap_loc(fs, i))) {
1166                         ext2fs_block_alloc_stats2(fs, blk, +1);
1167                         if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
1168                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
1169                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
1170                                                          blk);
1171                 }
1172                 if (ext2fs_inode_bitmap_loc(old_fs, i) !=
1173                     (blk = ext2fs_inode_bitmap_loc(fs, i))) {
1174                         ext2fs_block_alloc_stats2(fs, blk, +1);
1175                         if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
1176                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
1177                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
1178                                                          blk);
1179                 }
1180
1181                 /*
1182                  * The inode table, if we need to relocate it, is
1183                  * handled specially.  We have to reserve the blocks
1184                  * for both the old and the new inode table, since we
1185                  * can't have the inode table be destroyed during the
1186                  * block relocation phase.
1187                  */
1188                 if (ext2fs_inode_table_loc(fs, i) == ext2fs_inode_table_loc(old_fs, i))
1189                         continue;       /* inode table not moved */
1190
1191                 rfs->needed_blocks += fs->inode_blocks_per_group;
1192
1193                 /*
1194                  * Mark the new inode table as in use in the new block
1195                  * allocation bitmap, and move any blocks that might
1196                  * be necessary.
1197                  */
1198                 for (blk = ext2fs_inode_table_loc(fs, i), j=0;
1199                      j < fs->inode_blocks_per_group ; j++, blk++) {
1200                         ext2fs_block_alloc_stats2(fs, blk, +1);
1201                         if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
1202                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
1203                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
1204                                                          blk);
1205                 }
1206
1207                 /*
1208                  * Make sure the old inode table is reserved in the
1209                  * block reservation bitmap.
1210                  */
1211                 for (blk = ext2fs_inode_table_loc(rfs->old_fs, i), j=0;
1212                      j < fs->inode_blocks_per_group ; j++, blk++)
1213                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
1214         }
1215         retval = 0;
1216
1217 errout:
1218         if (new_meta_bmap)
1219                 ext2fs_free_block_bitmap(new_meta_bmap);
1220         if (meta_bmap)
1221                 ext2fs_free_block_bitmap(meta_bmap);
1222
1223         return retval;
1224 }
1225
1226 /*
1227  * This helper function tries to allocate a new block.  We try to
1228  * avoid hitting the original group descriptor blocks at least at
1229  * first, since we want to make it possible to recover from a badly
1230  * aborted resize operation as much as possible.
1231  *
1232  * In the future, I may further modify this routine to balance out
1233  * where we get the new blocks across the various block groups.
1234  * Ideally we would allocate blocks that corresponded with the block
1235  * group of the containing inode, and keep contiguous blocks
1236  * together.  However, this very difficult to do efficiently, since we
1237  * don't have the necessary information up front.
1238  */
1239
1240 #define AVOID_OLD       1
1241 #define DESPERATION     2
1242
1243 static void init_block_alloc(ext2_resize_t rfs)
1244 {
1245         rfs->alloc_state = AVOID_OLD;
1246         rfs->new_blk = rfs->new_fs->super->s_first_data_block;
1247 #if 0
1248         /* HACK for testing */
1249         if (ext2fs_blocks_count(rfs->new_fs->super) >
1250             ext2fs_blocks_count(rfs->old_fs->super))
1251                 rfs->new_blk = ext2fs_blocks_count(rfs->old_fs->super);
1252 #endif
1253 }
1254
1255 static blk64_t get_new_block(ext2_resize_t rfs)
1256 {
1257         ext2_filsys     fs = rfs->new_fs;
1258
1259         while (1) {
1260                 if (rfs->new_blk >= ext2fs_blocks_count(fs->super)) {
1261                         if (rfs->alloc_state == DESPERATION)
1262                                 return 0;
1263
1264 #ifdef RESIZE2FS_DEBUG
1265                         if (rfs->flags & RESIZE_DEBUG_BMOVE)
1266                                 printf("Going into desperation mode "
1267                                        "for block allocations\n");
1268 #endif
1269                         rfs->alloc_state = DESPERATION;
1270                         rfs->new_blk = fs->super->s_first_data_block;
1271                         continue;
1272                 }
1273                 if (ext2fs_test_block_bitmap2(fs->block_map, rfs->new_blk) ||
1274                     ext2fs_test_block_bitmap2(rfs->reserve_blocks,
1275                                              rfs->new_blk) ||
1276                     ((rfs->alloc_state == AVOID_OLD) &&
1277                      (rfs->new_blk < ext2fs_blocks_count(rfs->old_fs->super)) &&
1278                      ext2fs_test_block_bitmap2(rfs->old_fs->block_map,
1279                                               rfs->new_blk))) {
1280                         rfs->new_blk++;
1281                         continue;
1282                 }
1283                 return rfs->new_blk;
1284         }
1285 }
1286
1287 static errcode_t resize2fs_get_alloc_block(ext2_filsys fs, blk64_t goal,
1288                                            blk64_t *ret)
1289 {
1290         ext2_resize_t rfs = (ext2_resize_t) fs->priv_data;
1291         blk64_t blk;
1292
1293         blk = get_new_block(rfs);
1294         if (!blk)
1295                 return ENOSPC;
1296
1297 #ifdef RESIZE2FS_DEBUG
1298         if (rfs->flags & 0xF)
1299                 printf("get_alloc_block allocating %llu\n", blk);
1300 #endif
1301
1302         ext2fs_mark_block_bitmap2(rfs->old_fs->block_map, blk);
1303         ext2fs_mark_block_bitmap2(rfs->new_fs->block_map, blk);
1304         *ret = (blk64_t) blk;
1305         return 0;
1306 }
1307
1308 static errcode_t block_mover(ext2_resize_t rfs)
1309 {
1310         blk64_t                 blk, old_blk, new_blk;
1311         ext2_filsys             fs = rfs->new_fs;
1312         ext2_filsys             old_fs = rfs->old_fs;
1313         errcode_t               retval;
1314         __u64                   size;
1315         int                     c;
1316         int                     to_move, moved;
1317         ext2_badblocks_list     badblock_list = 0;
1318         int                     bb_modified = 0;
1319
1320         fs->get_alloc_block = resize2fs_get_alloc_block;
1321         old_fs->get_alloc_block = resize2fs_get_alloc_block;
1322
1323         retval = ext2fs_read_bb_inode(old_fs, &badblock_list);
1324         if (retval)
1325                 return retval;
1326
1327         new_blk = fs->super->s_first_data_block;
1328         if (!rfs->itable_buf) {
1329                 retval = ext2fs_get_array(fs->blocksize,
1330                                         fs->inode_blocks_per_group,
1331                                         &rfs->itable_buf);
1332                 if (retval)
1333                         return retval;
1334         }
1335         retval = ext2fs_create_extent_table(&rfs->bmap, 0);
1336         if (retval)
1337                 return retval;
1338
1339         /*
1340          * The first step is to figure out where all of the blocks
1341          * will go.
1342          */
1343         to_move = moved = 0;
1344         init_block_alloc(rfs);
1345         for (blk = B2C(old_fs->super->s_first_data_block);
1346              blk < ext2fs_blocks_count(old_fs->super);
1347              blk += EXT2FS_CLUSTER_RATIO(fs)) {
1348                 if (!ext2fs_test_block_bitmap2(old_fs->block_map, blk))
1349                         continue;
1350                 if (!ext2fs_test_block_bitmap2(rfs->move_blocks, blk))
1351                         continue;
1352                 if (ext2fs_badblocks_list_test(badblock_list, blk)) {
1353                         ext2fs_badblocks_list_del(badblock_list, blk);
1354                         bb_modified++;
1355                         continue;
1356                 }
1357
1358                 new_blk = get_new_block(rfs);
1359                 if (!new_blk) {
1360                         retval = ENOSPC;
1361                         goto errout;
1362                 }
1363                 ext2fs_block_alloc_stats2(fs, new_blk, +1);
1364                 ext2fs_add_extent_entry(rfs->bmap, B2C(blk), B2C(new_blk));
1365                 to_move++;
1366         }
1367
1368         if (to_move == 0) {
1369                 if (rfs->bmap) {
1370                         ext2fs_free_extent_table(rfs->bmap);
1371                         rfs->bmap = 0;
1372                 }
1373                 retval = 0;
1374                 goto errout;
1375         }
1376
1377         /*
1378          * Step two is to actually move the blocks
1379          */
1380         retval =  ext2fs_iterate_extent(rfs->bmap, 0, 0, 0);
1381         if (retval) goto errout;
1382
1383         if (rfs->progress) {
1384                 retval = (rfs->progress)(rfs, E2_RSZ_BLOCK_RELOC_PASS,
1385                                          0, to_move);
1386                 if (retval)
1387                         goto errout;
1388         }
1389         while (1) {
1390                 retval = ext2fs_iterate_extent(rfs->bmap, &old_blk, &new_blk, &size);
1391                 if (retval) goto errout;
1392                 if (!size)
1393                         break;
1394                 old_blk = C2B(old_blk);
1395                 new_blk = C2B(new_blk);
1396                 size = C2B(size);
1397 #ifdef RESIZE2FS_DEBUG
1398                 if (rfs->flags & RESIZE_DEBUG_BMOVE)
1399                         printf("Moving %llu blocks %llu->%llu\n",
1400                                size, old_blk, new_blk);
1401 #endif
1402                 do {
1403                         c = size;
1404                         if (c > fs->inode_blocks_per_group)
1405                                 c = fs->inode_blocks_per_group;
1406                         retval = io_channel_read_blk64(fs->io, old_blk, c,
1407                                                        rfs->itable_buf);
1408                         if (retval) goto errout;
1409                         retval = io_channel_write_blk64(fs->io, new_blk, c,
1410                                                         rfs->itable_buf);
1411                         if (retval) goto errout;
1412                         size -= c;
1413                         new_blk += c;
1414                         old_blk += c;
1415                         moved += c;
1416                         if (rfs->progress) {
1417                                 io_channel_flush(fs->io);
1418                                 retval = (rfs->progress)(rfs,
1419                                                 E2_RSZ_BLOCK_RELOC_PASS,
1420                                                 moved, to_move);
1421                                 if (retval)
1422                                         goto errout;
1423                         }
1424                 } while (size > 0);
1425                 io_channel_flush(fs->io);
1426         }
1427
1428 errout:
1429         if (badblock_list) {
1430                 if (!retval && bb_modified)
1431                         retval = ext2fs_update_bb_inode(old_fs,
1432                                                         badblock_list);
1433                 ext2fs_badblocks_list_free(badblock_list);
1434         }
1435         return retval;
1436 }
1437
1438
1439 /* --------------------------------------------------------------------
1440  *
1441  * Resize processing, phase 3
1442  *
1443  * --------------------------------------------------------------------
1444  */
1445
1446
1447 /*
1448  * The extent translation table is stored in clusters so we need to
1449  * take special care when mapping a source block number to its
1450  * destination block number.
1451  */
1452 static __u64 extent_translate(ext2_filsys fs, ext2_extent extent, __u64 old_loc)
1453 {
1454         __u64 new_block = C2B(ext2fs_extent_translate(extent, B2C(old_loc)));
1455
1456         if (new_block != 0)
1457                 new_block += old_loc & (EXT2FS_CLUSTER_RATIO(fs) - 1);
1458         return new_block;
1459 }
1460
1461 struct process_block_struct {
1462         ext2_resize_t           rfs;
1463         ext2_ino_t              ino;
1464         struct ext2_inode *     inode;
1465         errcode_t               error;
1466         int                     is_dir;
1467         int                     changed;
1468 };
1469
1470 static int process_block(ext2_filsys fs, blk64_t        *block_nr,
1471                          e2_blkcnt_t blockcnt,
1472                          blk64_t ref_block EXT2FS_ATTR((unused)),
1473                          int ref_offset EXT2FS_ATTR((unused)), void *priv_data)
1474 {
1475         struct process_block_struct *pb;
1476         errcode_t       retval;
1477         blk64_t         block, new_block;
1478         int             ret = 0;
1479
1480         pb = (struct process_block_struct *) priv_data;
1481         block = *block_nr;
1482         if (pb->rfs->bmap) {
1483                 new_block = extent_translate(fs, pb->rfs->bmap, block);
1484                 if (new_block) {
1485                         *block_nr = new_block;
1486                         ret |= BLOCK_CHANGED;
1487                         pb->changed = 1;
1488 #ifdef RESIZE2FS_DEBUG
1489                         if (pb->rfs->flags & RESIZE_DEBUG_BMOVE)
1490                                 printf("ino=%u, blockcnt=%lld, %llu->%llu\n",
1491                                        pb->ino, blockcnt, block, new_block);
1492 #endif
1493                         block = new_block;
1494                 }
1495         }
1496         if (pb->is_dir) {
1497                 retval = ext2fs_add_dir_block2(fs->dblist, pb->ino,
1498                                                block, (int) blockcnt);
1499                 if (retval) {
1500                         pb->error = retval;
1501                         ret |= BLOCK_ABORT;
1502                 }
1503         }
1504         return ret;
1505 }
1506
1507 /*
1508  * Progress callback
1509  */
1510 static errcode_t progress_callback(ext2_filsys fs,
1511                                    ext2_inode_scan scan EXT2FS_ATTR((unused)),
1512                                    dgrp_t group, void * priv_data)
1513 {
1514         ext2_resize_t rfs = (ext2_resize_t) priv_data;
1515         errcode_t               retval;
1516
1517         /*
1518          * This check is to protect against old ext2 libraries.  It
1519          * shouldn't be needed against new libraries.
1520          */
1521         if ((group+1) == 0)
1522                 return 0;
1523
1524         if (rfs->progress) {
1525                 io_channel_flush(fs->io);
1526                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
1527                                          group+1, fs->group_desc_count);
1528                 if (retval)
1529                         return retval;
1530         }
1531
1532         return 0;
1533 }
1534
1535 static errcode_t inode_scan_and_fix(ext2_resize_t rfs)
1536 {
1537         struct process_block_struct     pb;
1538         ext2_ino_t              ino, new_inode;
1539         struct ext2_inode       *inode = NULL;
1540         ext2_inode_scan         scan = NULL;
1541         errcode_t               retval;
1542         char                    *block_buf = 0;
1543         ext2_ino_t              start_to_move;
1544         blk64_t                 orig_size;
1545         blk64_t                 new_block;
1546         int                     inode_size;
1547
1548         if ((rfs->old_fs->group_desc_count <=
1549              rfs->new_fs->group_desc_count) &&
1550             !rfs->bmap)
1551                 return 0;
1552
1553         /*
1554          * Save the original size of the old filesystem, and
1555          * temporarily set the size to be the new size if the new size
1556          * is larger.  We need to do this to avoid catching an error
1557          * by the block iterator routines
1558          */
1559         orig_size = ext2fs_blocks_count(rfs->old_fs->super);
1560         if (orig_size < ext2fs_blocks_count(rfs->new_fs->super))
1561                 ext2fs_blocks_count_set(rfs->old_fs->super,
1562                                 ext2fs_blocks_count(rfs->new_fs->super));
1563
1564         retval = ext2fs_open_inode_scan(rfs->old_fs, 0, &scan);
1565         if (retval) goto errout;
1566
1567         retval = ext2fs_init_dblist(rfs->old_fs, 0);
1568         if (retval) goto errout;
1569         retval = ext2fs_get_array(rfs->old_fs->blocksize, 3, &block_buf);
1570         if (retval) goto errout;
1571
1572         start_to_move = (rfs->new_fs->group_desc_count *
1573                          rfs->new_fs->super->s_inodes_per_group);
1574
1575         if (rfs->progress) {
1576                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
1577                                          0, rfs->old_fs->group_desc_count);
1578                 if (retval)
1579                         goto errout;
1580         }
1581         ext2fs_set_inode_callback(scan, progress_callback, (void *) rfs);
1582         pb.rfs = rfs;
1583         pb.inode = inode;
1584         pb.error = 0;
1585         new_inode = EXT2_FIRST_INODE(rfs->new_fs->super);
1586         inode_size = EXT2_INODE_SIZE(rfs->new_fs->super);
1587         retval = ext2fs_get_mem(inode_size, &inode);
1588         if (retval) {
1589                 retval = ENOMEM;
1590                 goto errout;
1591         }
1592         /*
1593          * First, copy all of the inodes that need to be moved
1594          * elsewhere in the inode table
1595          */
1596         while (1) {
1597                 retval = ext2fs_get_next_inode_full(scan, &ino, inode, inode_size);
1598                 if (retval) goto errout;
1599                 if (!ino)
1600                         break;
1601
1602                 if (inode->i_links_count == 0 && ino != EXT2_RESIZE_INO)
1603                         continue; /* inode not in use */
1604
1605                 pb.is_dir = LINUX_S_ISDIR(inode->i_mode);
1606                 pb.changed = 0;
1607
1608                 if (ext2fs_file_acl_block(rfs->old_fs, inode) && rfs->bmap) {
1609                         new_block = extent_translate(rfs->old_fs, rfs->bmap,
1610                                 ext2fs_file_acl_block(rfs->old_fs, inode));
1611                         if (new_block) {
1612                                 ext2fs_file_acl_block_set(rfs->old_fs, inode,
1613                                                           new_block);
1614                                 retval = ext2fs_write_inode_full(rfs->old_fs,
1615                                                             ino, inode, inode_size);
1616                                 if (retval) goto errout;
1617                         }
1618                 }
1619
1620                 if (ext2fs_inode_has_valid_blocks2(rfs->old_fs, inode) &&
1621                     (rfs->bmap || pb.is_dir)) {
1622                         pb.ino = ino;
1623                         retval = ext2fs_block_iterate3(rfs->old_fs,
1624                                                        ino, 0, block_buf,
1625                                                        process_block, &pb);
1626                         if (retval)
1627                                 goto errout;
1628                         if (pb.error) {
1629                                 retval = pb.error;
1630                                 goto errout;
1631                         }
1632                 }
1633
1634                 if (ino <= start_to_move)
1635                         continue; /* Don't need to move it. */
1636
1637                 /*
1638                  * Find a new inode
1639                  */
1640                 retval = ext2fs_new_inode(rfs->new_fs, 0, 0, 0, &new_inode);
1641                 if (retval)
1642                         goto errout;
1643
1644                 ext2fs_inode_alloc_stats2(rfs->new_fs, new_inode, +1,
1645                                           pb.is_dir);
1646                 if (pb.changed) {
1647                         /* Get the new version of the inode */
1648                         retval = ext2fs_read_inode_full(rfs->old_fs, ino,
1649                                                 inode, inode_size);
1650                         if (retval) goto errout;
1651                 }
1652                 inode->i_ctime = time(0);
1653                 retval = ext2fs_write_inode_full(rfs->old_fs, new_inode,
1654                                                 inode, inode_size);
1655                 if (retval) goto errout;
1656
1657 #ifdef RESIZE2FS_DEBUG
1658                 if (rfs->flags & RESIZE_DEBUG_INODEMAP)
1659                         printf("Inode moved %u->%u\n", ino, new_inode);
1660 #endif
1661                 if (!rfs->imap) {
1662                         retval = ext2fs_create_extent_table(&rfs->imap, 0);
1663                         if (retval)
1664                                 goto errout;
1665                 }
1666                 ext2fs_add_extent_entry(rfs->imap, ino, new_inode);
1667         }
1668         io_channel_flush(rfs->old_fs->io);
1669
1670 errout:
1671         ext2fs_blocks_count_set(rfs->old_fs->super, orig_size);
1672         if (rfs->bmap) {
1673                 ext2fs_free_extent_table(rfs->bmap);
1674                 rfs->bmap = 0;
1675         }
1676         if (scan)
1677                 ext2fs_close_inode_scan(scan);
1678         if (block_buf)
1679                 ext2fs_free_mem(&block_buf);
1680         if (inode)
1681                 ext2fs_free_mem(&inode);
1682         return retval;
1683 }
1684
1685 /* --------------------------------------------------------------------
1686  *
1687  * Resize processing, phase 4.
1688  *
1689  * --------------------------------------------------------------------
1690  */
1691
1692 struct istruct {
1693         ext2_resize_t rfs;
1694         errcode_t       err;
1695         unsigned int    max_dirs;
1696         unsigned int    num;
1697 };
1698
1699 static int check_and_change_inodes(ext2_ino_t dir,
1700                                    int entry EXT2FS_ATTR((unused)),
1701                                    struct ext2_dir_entry *dirent, int offset,
1702                                    int  blocksize EXT2FS_ATTR((unused)),
1703                                    char *buf EXT2FS_ATTR((unused)),
1704                                    void *priv_data)
1705 {
1706         struct istruct *is = (struct istruct *) priv_data;
1707         struct ext2_inode       inode;
1708         ext2_ino_t              new_inode;
1709         errcode_t               retval;
1710
1711         if (is->rfs->progress && offset == 0) {
1712                 io_channel_flush(is->rfs->old_fs->io);
1713                 is->err = (is->rfs->progress)(is->rfs,
1714                                               E2_RSZ_INODE_REF_UPD_PASS,
1715                                               ++is->num, is->max_dirs);
1716                 if (is->err)
1717                         return DIRENT_ABORT;
1718         }
1719
1720         if (!dirent->inode)
1721                 return 0;
1722
1723         new_inode = ext2fs_extent_translate(is->rfs->imap, dirent->inode);
1724
1725         if (!new_inode)
1726                 return 0;
1727 #ifdef RESIZE2FS_DEBUG
1728         if (is->rfs->flags & RESIZE_DEBUG_INODEMAP)
1729                 printf("Inode translate (dir=%u, name=%.*s, %u->%u)\n",
1730                        dir, dirent->name_len&0xFF, dirent->name,
1731                        dirent->inode, new_inode);
1732 #endif
1733
1734         dirent->inode = new_inode;
1735
1736         /* Update the directory mtime and ctime */
1737         retval = ext2fs_read_inode(is->rfs->old_fs, dir, &inode);
1738         if (retval == 0) {
1739                 inode.i_mtime = inode.i_ctime = time(0);
1740                 is->err = ext2fs_write_inode(is->rfs->old_fs, dir, &inode);
1741                 if (is->err)
1742                         return DIRENT_ABORT;
1743         }
1744
1745         return DIRENT_CHANGED;
1746 }
1747
1748 static errcode_t inode_ref_fix(ext2_resize_t rfs)
1749 {
1750         errcode_t               retval;
1751         struct istruct          is;
1752
1753         if (!rfs->imap)
1754                 return 0;
1755
1756         /*
1757          * Now, we iterate over all of the directories to update the
1758          * inode references
1759          */
1760         is.num = 0;
1761         is.max_dirs = ext2fs_dblist_count2(rfs->old_fs->dblist);
1762         is.rfs = rfs;
1763         is.err = 0;
1764
1765         if (rfs->progress) {
1766                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS,
1767                                          0, is.max_dirs);
1768                 if (retval)
1769                         goto errout;
1770         }
1771
1772         retval = ext2fs_dblist_dir_iterate(rfs->old_fs->dblist,
1773                                            DIRENT_FLAG_INCLUDE_EMPTY, 0,
1774                                            check_and_change_inodes, &is);
1775         if (retval)
1776                 goto errout;
1777         if (is.err) {
1778                 retval = is.err;
1779                 goto errout;
1780         }
1781
1782         if (rfs->progress && (is.num < is.max_dirs))
1783                 (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS,
1784                                 is.max_dirs, is.max_dirs);
1785
1786 errout:
1787         ext2fs_free_extent_table(rfs->imap);
1788         rfs->imap = 0;
1789         return retval;
1790 }
1791
1792
1793 /* --------------------------------------------------------------------
1794  *
1795  * Resize processing, phase 5.
1796  *
1797  * In this phase we actually move the inode table around, and then
1798  * update the summary statistics.  This is scary, since aborting here
1799  * will potentially scramble the filesystem.  (We are moving the
1800  * inode tables around in place, and so the potential for lost data,
1801  * or at the very least scrambling the mapping between filenames and
1802  * inode numbers is very high in case of a power failure here.)
1803  * --------------------------------------------------------------------
1804  */
1805
1806
1807 /*
1808  * A very scary routine --- this one moves the inode table around!!!
1809  *
1810  * After this you have to use the rfs->new_fs file handle to read and
1811  * write inodes.
1812  */
1813 static errcode_t move_itables(ext2_resize_t rfs)
1814 {
1815         int             n, num, size;
1816         long long       diff;
1817         dgrp_t          i, max_groups;
1818         ext2_filsys     fs = rfs->new_fs;
1819         char            *cp;
1820         blk64_t         old_blk, new_blk, blk, cluster_freed;
1821         errcode_t       retval;
1822         int             j, to_move, moved;
1823         ext2fs_block_bitmap     new_bmap = NULL;
1824
1825         max_groups = fs->group_desc_count;
1826         if (max_groups > rfs->old_fs->group_desc_count)
1827                 max_groups = rfs->old_fs->group_desc_count;
1828
1829         size = fs->blocksize * fs->inode_blocks_per_group;
1830         if (!rfs->itable_buf) {
1831                 retval = ext2fs_get_mem(size, &rfs->itable_buf);
1832                 if (retval)
1833                         return retval;
1834         }
1835
1836         if (EXT2FS_CLUSTER_RATIO(fs) > 1) {
1837                 retval = ext2fs_allocate_block_bitmap(fs, _("new meta blocks"),
1838                                                       &new_bmap);
1839                 if (retval)
1840                         return retval;
1841
1842                 retval = mark_table_blocks(fs, new_bmap);
1843                 if (retval)
1844                         goto errout;
1845         }
1846
1847         /*
1848          * Figure out how many inode tables we need to move
1849          */
1850         to_move = moved = 0;
1851         for (i=0; i < max_groups; i++)
1852                 if (ext2fs_inode_table_loc(rfs->old_fs, i) !=
1853                     ext2fs_inode_table_loc(fs, i))
1854                         to_move++;
1855
1856         if (to_move == 0) {
1857                 retval = 0;
1858                 goto errout;
1859         }
1860
1861         if (rfs->progress) {
1862                 retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
1863                                        0, to_move);
1864                 if (retval)
1865                         goto errout;
1866         }
1867
1868         rfs->old_fs->flags |= EXT2_FLAG_MASTER_SB_ONLY;
1869
1870         for (i=0; i < max_groups; i++) {
1871                 old_blk = ext2fs_inode_table_loc(rfs->old_fs, i);
1872                 new_blk = ext2fs_inode_table_loc(fs, i);
1873                 diff = new_blk - old_blk;
1874
1875 #ifdef RESIZE2FS_DEBUG
1876                 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1877                         printf("Itable move group %d block %llu->%llu (diff %lld)\n",
1878                                i, old_blk, new_blk, diff);
1879 #endif
1880
1881                 if (!diff)
1882                         continue;
1883                 if (diff < 0)
1884                         diff = 0;
1885
1886                 retval = io_channel_read_blk64(fs->io, old_blk,
1887                                                fs->inode_blocks_per_group,
1888                                                rfs->itable_buf);
1889                 if (retval)
1890                         goto errout;
1891                 /*
1892                  * The end of the inode table segment often contains
1893                  * all zeros, and we're often only moving the inode
1894                  * table down a block or two.  If so, we can optimize
1895                  * things by not rewriting blocks that we know to be zero
1896                  * already.
1897                  */
1898                 for (cp = rfs->itable_buf+size-1, n=0; n < size; n++, cp--)
1899                         if (*cp)
1900                                 break;
1901                 n = n >> EXT2_BLOCK_SIZE_BITS(fs->super);
1902 #ifdef RESIZE2FS_DEBUG
1903                 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1904                         printf("%d blocks of zeros...\n", n);
1905 #endif
1906                 num = fs->inode_blocks_per_group;
1907                 if (n > diff)
1908                         num -= n;
1909
1910                 retval = io_channel_write_blk64(fs->io, new_blk,
1911                                                 num, rfs->itable_buf);
1912                 if (retval) {
1913                         io_channel_write_blk64(fs->io, old_blk,
1914                                                num, rfs->itable_buf);
1915                         goto errout;
1916                 }
1917                 if (n > diff) {
1918                         retval = io_channel_write_blk64(fs->io,
1919                               old_blk + fs->inode_blocks_per_group,
1920                               diff, (rfs->itable_buf +
1921                                      (fs->inode_blocks_per_group - diff) *
1922                                      fs->blocksize));
1923                         if (retval)
1924                                 goto errout;
1925                 }
1926
1927                 for (blk = ext2fs_inode_table_loc(rfs->old_fs, i), j=0;
1928                      j < fs->inode_blocks_per_group;) {
1929                         if (new_bmap == NULL ||
1930                             !ext2fs_test_block_bitmap2(new_bmap, blk)) {
1931                                 ext2fs_block_alloc_stats2(fs, blk, -1);
1932                                 cluster_freed = EXT2FS_CLUSTER_RATIO(fs) -
1933                                                 (blk & EXT2FS_CLUSTER_MASK(fs));
1934                                 blk += cluster_freed;
1935                                 j += cluster_freed;
1936                                 continue;
1937                         }
1938                         blk++;
1939                         j++;
1940                 }
1941
1942                 ext2fs_inode_table_loc_set(rfs->old_fs, i, new_blk);
1943                 ext2fs_group_desc_csum_set(rfs->old_fs, i);
1944                 ext2fs_mark_super_dirty(rfs->old_fs);
1945                 ext2fs_flush(rfs->old_fs);
1946
1947                 if (rfs->progress) {
1948                         retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
1949                                                ++moved, to_move);
1950                         if (retval)
1951                                 goto errout;
1952                 }
1953         }
1954         mark_table_blocks(fs, fs->block_map);
1955         ext2fs_flush(fs);
1956 #ifdef RESIZE2FS_DEBUG
1957         if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1958                 printf("Inode table move finished.\n");
1959 #endif
1960         retval = 0;
1961
1962 errout:
1963         if (new_bmap)
1964                 ext2fs_free_block_bitmap(new_bmap);
1965         return retval;
1966 }
1967
1968 /*
1969  * This function is used when expanding a file system.  It frees the
1970  * superblock and block group descriptor blocks from the block group
1971  * which is no longer the last block group.
1972  */
1973 static errcode_t clear_sparse_super2_last_group(ext2_resize_t rfs)
1974 {
1975         ext2_filsys     fs = rfs->new_fs;
1976         ext2_filsys     old_fs = rfs->old_fs;
1977         errcode_t       retval;
1978         dgrp_t          old_last_bg = rfs->old_fs->group_desc_count - 1;
1979         dgrp_t          last_bg = fs->group_desc_count - 1;
1980         blk64_t         sb, old_desc;
1981         blk_t           num;
1982
1983         if (!(fs->super->s_feature_compat & EXT4_FEATURE_COMPAT_SPARSE_SUPER2))
1984                 return 0;
1985
1986         if (last_bg <= old_last_bg)
1987                 return 0;
1988
1989         if (fs->super->s_backup_bgs[0] == old_fs->super->s_backup_bgs[0] &&
1990             fs->super->s_backup_bgs[1] == old_fs->super->s_backup_bgs[1])
1991                 return 0;
1992
1993         if (old_fs->super->s_backup_bgs[0] != old_last_bg &&
1994             old_fs->super->s_backup_bgs[1] != old_last_bg)
1995                 return 0;
1996
1997         if (fs->super->s_backup_bgs[0] == old_last_bg ||
1998             fs->super->s_backup_bgs[1] == old_last_bg)
1999                 return 0;
2000
2001         retval = ext2fs_super_and_bgd_loc2(rfs->old_fs, old_last_bg,
2002                                            &sb, &old_desc, NULL, &num);
2003         if (retval)
2004                 return retval;
2005
2006         if (sb)
2007                 ext2fs_unmark_block_bitmap2(fs->block_map, sb);
2008         if (old_desc)
2009                 ext2fs_unmark_block_bitmap_range2(fs->block_map, old_desc, num);
2010         return 0;
2011 }
2012
2013 /*
2014  * This function is used when shrinking a file system.  We need to
2015  * utilize blocks from what will be the new last block group for the
2016  * backup superblock and block group descriptor blocks.
2017  * Unfortunately, those blocks may be used by other files or fs
2018  * metadata blocks.  We need to mark them as being in use.
2019  */
2020 static errcode_t reserve_sparse_super2_last_group(ext2_resize_t rfs,
2021                                                  ext2fs_block_bitmap meta_bmap)
2022 {
2023         ext2_filsys     fs = rfs->new_fs;
2024         ext2_filsys     old_fs = rfs->old_fs;
2025         errcode_t       retval;
2026         dgrp_t          old_last_bg = rfs->old_fs->group_desc_count - 1;
2027         dgrp_t          last_bg = fs->group_desc_count - 1;
2028         dgrp_t          g;
2029         blk64_t         blk, sb, old_desc;
2030         blk_t           i, num;
2031         int             realloc = 0;
2032
2033         if (!(fs->super->s_feature_compat & EXT4_FEATURE_COMPAT_SPARSE_SUPER2))
2034                 return 0;
2035
2036         if (last_bg >= old_last_bg)
2037                 return 0;
2038
2039         if (fs->super->s_backup_bgs[0] == old_fs->super->s_backup_bgs[0] &&
2040             fs->super->s_backup_bgs[1] == old_fs->super->s_backup_bgs[1])
2041                 return 0;
2042
2043         if (fs->super->s_backup_bgs[0] != last_bg &&
2044             fs->super->s_backup_bgs[1] != last_bg)
2045                 return 0;
2046
2047         if (old_fs->super->s_backup_bgs[0] == last_bg ||
2048             old_fs->super->s_backup_bgs[1] == last_bg)
2049                 return 0;
2050
2051         retval = ext2fs_super_and_bgd_loc2(rfs->new_fs, last_bg,
2052                                            &sb, &old_desc, NULL, &num);
2053         if (retval)
2054                 return retval;
2055
2056         if (!sb) {
2057                 fputs(_("Should never happen!  No sb in last super_sparse bg?\n"),
2058                       stderr);
2059                 exit(1);
2060         }
2061         if (old_desc && old_desc != sb+1) {
2062                 fputs(_("Should never happen!  Unexpected old_desc in "
2063                         "super_sparse bg?\n"),
2064                       stderr);
2065                 exit(1);
2066         }
2067         num = (old_desc) ? num : 1;
2068
2069         /* Reserve the backup blocks */
2070         ext2fs_mark_block_bitmap_range2(fs->block_map, sb, num);
2071
2072         for (g = 0; g < fs->group_desc_count; g++) {
2073                 blk64_t mb;
2074
2075                 mb = ext2fs_block_bitmap_loc(fs, g);
2076                 if ((mb >= sb) && (mb < sb + num)) {
2077                         ext2fs_block_bitmap_loc_set(fs, g, 0);
2078                         realloc = 1;
2079                 }
2080                 mb = ext2fs_inode_bitmap_loc(fs, g);
2081                 if ((mb >= sb) && (mb < sb + num)) {
2082                         ext2fs_inode_bitmap_loc_set(fs, g, 0);
2083                         realloc = 1;
2084                 }
2085                 mb = ext2fs_inode_table_loc(fs, g);
2086                 if ((mb < sb + num) &&
2087                     (sb < mb + fs->inode_blocks_per_group)) {
2088                         ext2fs_inode_table_loc_set(fs, g, 0);
2089                         realloc = 1;
2090                 }
2091                 if (realloc) {
2092                         retval = ext2fs_allocate_group_table(fs, g, 0);
2093                         if (retval)
2094                                 return retval;
2095                 }
2096         }
2097
2098         for (blk = sb, i = 0; i < num; blk++, i++) {
2099                 if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
2100                     !ext2fs_test_block_bitmap2(meta_bmap, blk)) {
2101                         ext2fs_mark_block_bitmap2(rfs->move_blocks, blk);
2102                         rfs->needed_blocks++;
2103                 }
2104                 ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
2105         }
2106         return 0;
2107 }
2108
2109 /*
2110  * Fix the resize inode
2111  */
2112 static errcode_t fix_resize_inode(ext2_filsys fs)
2113 {
2114         struct ext2_inode       inode;
2115         errcode_t               retval;
2116         char                    *block_buf = NULL;
2117
2118         if (!(fs->super->s_feature_compat &
2119               EXT2_FEATURE_COMPAT_RESIZE_INODE))
2120                 return 0;
2121
2122         retval = ext2fs_get_mem(fs->blocksize, &block_buf);
2123         if (retval) goto errout;
2124
2125         retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode);
2126         if (retval) goto errout;
2127
2128         ext2fs_iblk_set(fs, &inode, 1);
2129
2130         retval = ext2fs_write_inode(fs, EXT2_RESIZE_INO, &inode);
2131         if (retval) goto errout;
2132
2133         if (!inode.i_block[EXT2_DIND_BLOCK]) {
2134                 /*
2135                  * Avoid zeroing out block #0; that's rude.  This
2136                  * should never happen anyway since the filesystem
2137                  * should be fsck'ed and we assume it is consistent.
2138                  */
2139                 fprintf(stderr, "%s",
2140                         _("Should never happen: resize inode corrupt!\n"));
2141                 exit(1);
2142         }
2143
2144         memset(block_buf, 0, fs->blocksize);
2145
2146         retval = io_channel_write_blk64(fs->io, inode.i_block[EXT2_DIND_BLOCK],
2147                                         1, block_buf);
2148         if (retval) goto errout;
2149
2150         retval = ext2fs_create_resize_inode(fs);
2151         if (retval)
2152                 goto errout;
2153
2154 errout:
2155         if (block_buf)
2156                 ext2fs_free_mem(&block_buf);
2157         return retval;
2158 }
2159
2160 /*
2161  * Finally, recalculate the summary information
2162  */
2163 static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs)
2164 {
2165         blk64_t         blk;
2166         ext2_ino_t      ino;
2167         unsigned int    group = 0;
2168         unsigned int    count = 0;
2169         blk64_t         total_blocks_free = 0;
2170         int             total_inodes_free = 0;
2171         int             group_free = 0;
2172         int             uninit = 0;
2173         blk64_t         super_blk, old_desc_blk, new_desc_blk;
2174         int             old_desc_blocks;
2175
2176         /*
2177          * First calculate the block statistics
2178          */
2179         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT);
2180         ext2fs_super_and_bgd_loc2(fs, group, &super_blk, &old_desc_blk,
2181                                   &new_desc_blk, 0);
2182         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
2183                 old_desc_blocks = fs->super->s_first_meta_bg;
2184         else
2185                 old_desc_blocks = fs->desc_blocks +
2186                         fs->super->s_reserved_gdt_blocks;
2187         for (blk = B2C(fs->super->s_first_data_block);
2188              blk < ext2fs_blocks_count(fs->super);
2189              blk += EXT2FS_CLUSTER_RATIO(fs)) {
2190                 if ((uninit &&
2191                      !(EQ_CLSTR(blk, super_blk) ||
2192                        ((old_desc_blk && old_desc_blocks &&
2193                          GE_CLSTR(blk, old_desc_blk) &&
2194                          LT_CLSTR(blk, old_desc_blk + old_desc_blocks))) ||
2195                        ((new_desc_blk && EQ_CLSTR(blk, new_desc_blk))) ||
2196                        EQ_CLSTR(blk, ext2fs_block_bitmap_loc(fs, group)) ||
2197                        EQ_CLSTR(blk, ext2fs_inode_bitmap_loc(fs, group)) ||
2198                        ((GE_CLSTR(blk, ext2fs_inode_table_loc(fs, group)) &&
2199                          LT_CLSTR(blk, ext2fs_inode_table_loc(fs, group)
2200                                   + fs->inode_blocks_per_group))))) ||
2201                     (!ext2fs_fast_test_block_bitmap2(fs->block_map, blk))) {
2202                         group_free++;
2203                         total_blocks_free++;
2204                 }
2205                 count++;
2206                 if ((count == fs->super->s_clusters_per_group) ||
2207                     EQ_CLSTR(blk, ext2fs_blocks_count(fs->super)-1)) {
2208                         ext2fs_bg_free_blocks_count_set(fs, group, group_free);
2209                         ext2fs_group_desc_csum_set(fs, group);
2210                         group++;
2211                         if (group >= fs->group_desc_count)
2212                                 break;
2213                         count = 0;
2214                         group_free = 0;
2215                         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT);
2216                         ext2fs_super_and_bgd_loc2(fs, group, &super_blk,
2217                                                   &old_desc_blk,
2218                                                   &new_desc_blk, 0);
2219                         if (fs->super->s_feature_incompat &
2220                             EXT2_FEATURE_INCOMPAT_META_BG)
2221                                 old_desc_blocks = fs->super->s_first_meta_bg;
2222                         else
2223                                 old_desc_blocks = fs->desc_blocks +
2224                                         fs->super->s_reserved_gdt_blocks;
2225                 }
2226         }
2227         total_blocks_free = C2B(total_blocks_free);
2228         ext2fs_free_blocks_count_set(fs->super, total_blocks_free);
2229
2230         /*
2231          * Next, calculate the inode statistics
2232          */
2233         group_free = 0;
2234         count = 0;
2235         group = 0;
2236
2237         /* Protect loop from wrap-around if s_inodes_count maxed */
2238         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT);
2239         for (ino = 1; ino <= fs->super->s_inodes_count && ino > 0; ino++) {
2240                 if (uninit ||
2241                     !ext2fs_fast_test_inode_bitmap2(fs->inode_map, ino)) {
2242                         group_free++;
2243                         total_inodes_free++;
2244                 }
2245                 count++;
2246                 if ((count == fs->super->s_inodes_per_group) ||
2247                     (ino == fs->super->s_inodes_count)) {
2248                         ext2fs_bg_free_inodes_count_set(fs, group, group_free);
2249                         ext2fs_group_desc_csum_set(fs, group);
2250                         group++;
2251                         if (group >= fs->group_desc_count)
2252                                 break;
2253                         count = 0;
2254                         group_free = 0;
2255                         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT);
2256                 }
2257         }
2258         fs->super->s_free_inodes_count = total_inodes_free;
2259         ext2fs_mark_super_dirty(fs);
2260         return 0;
2261 }
2262
2263 /*
2264  *  Journal may have been relocated; update the backup journal blocks
2265  *  in the superblock.
2266  */
2267 static errcode_t fix_sb_journal_backup(ext2_filsys fs)
2268 {
2269         errcode_t         retval;
2270         struct ext2_inode inode;
2271
2272         if (!(fs->super->s_feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL))
2273                 return 0;
2274
2275         /* External journal? Nothing to do. */
2276         if (fs->super->s_journal_dev && !fs->super->s_journal_inum)
2277                 return 0;
2278
2279         retval = ext2fs_read_inode(fs, fs->super->s_journal_inum, &inode);
2280         if (retval)
2281                 return retval;
2282         memcpy(fs->super->s_jnl_blocks, inode.i_block, EXT2_N_BLOCKS*4);
2283         fs->super->s_jnl_blocks[15] = inode.i_size_high;
2284         fs->super->s_jnl_blocks[16] = inode.i_size;
2285         fs->super->s_jnl_backup_type = EXT3_JNL_BACKUP_BLOCKS;
2286         ext2fs_mark_super_dirty(fs);
2287         return 0;
2288 }
2289
2290 static int calc_group_overhead(ext2_filsys fs, blk64_t grp,
2291                                int old_desc_blocks)
2292 {
2293         blk64_t super_blk, old_desc_blk, new_desc_blk;
2294         int overhead;
2295
2296         /* inode table blocks plus allocation bitmaps */
2297         overhead = fs->inode_blocks_per_group + 2;
2298
2299         ext2fs_super_and_bgd_loc2(fs, grp, &super_blk,
2300                                   &old_desc_blk, &new_desc_blk, 0);
2301         if ((grp == 0) || super_blk)
2302                 overhead++;
2303         if (old_desc_blk)
2304                 overhead += old_desc_blocks;
2305         else if (new_desc_blk)
2306                 overhead++;
2307         return overhead;
2308 }
2309
2310
2311 /*
2312  * calcluate the minimum number of blocks the given fs can be resized to
2313  */
2314 blk64_t calculate_minimum_resize_size(ext2_filsys fs, int flags)
2315 {
2316         ext2_ino_t inode_count;
2317         dgrp_t groups, flex_groups;
2318         blk64_t blks_needed, data_blocks;
2319         blk64_t grp, data_needed, last_start;
2320         blk64_t overhead = 0;
2321         int old_desc_blocks;
2322         int flexbg_size = 1 << fs->super->s_log_groups_per_flex;
2323
2324         /*
2325          * first figure out how many group descriptors we need to
2326          * handle the number of inodes we have
2327          */
2328         inode_count = fs->super->s_inodes_count -
2329                 fs->super->s_free_inodes_count;
2330         blks_needed = ext2fs_div_ceil(inode_count,
2331                                       fs->super->s_inodes_per_group) *
2332                 (blk64_t) EXT2_BLOCKS_PER_GROUP(fs->super);
2333         groups = ext2fs_div64_ceil(blks_needed,
2334                                    EXT2_BLOCKS_PER_GROUP(fs->super));
2335 #ifdef RESIZE2FS_DEBUG
2336         if (flags & RESIZE_DEBUG_MIN_CALC)
2337                 printf("fs has %d inodes, %d groups required.\n",
2338                        inode_count, groups);
2339 #endif
2340
2341         /*
2342          * number of old-style block group descriptor blocks
2343          */
2344         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
2345                 old_desc_blocks = fs->super->s_first_meta_bg;
2346         else
2347                 old_desc_blocks = fs->desc_blocks +
2348                         fs->super->s_reserved_gdt_blocks;
2349
2350         /* calculate how many blocks are needed for data */
2351         data_needed = ext2fs_blocks_count(fs->super) -
2352                 ext2fs_free_blocks_count(fs->super);
2353
2354         for (grp = 0; grp < fs->group_desc_count; grp++)
2355                 data_needed -= calc_group_overhead(fs, grp, old_desc_blocks);
2356 #ifdef RESIZE2FS_DEBUG
2357         if (flags & RESIZE_DEBUG_MIN_CALC)
2358                 printf("fs requires %llu data blocks.\n", data_needed);
2359 #endif
2360
2361         /*
2362          * For ext4 we need to allow for up to a flex_bg worth of
2363          * inode tables of slack space so the resize operation can be
2364          * guaranteed to finish.
2365          */
2366         flex_groups = groups;
2367         if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_FLEX_BG) {
2368                 dgrp_t remainder = groups & (flexbg_size - 1);
2369
2370                 flex_groups += flexbg_size - remainder;
2371                 if (flex_groups > fs->group_desc_count)
2372                         flex_groups = fs->group_desc_count;
2373         }
2374
2375         /*
2376          * figure out how many data blocks we have given the number of groups
2377          * we need for our inodes
2378          */
2379         data_blocks = EXT2_GROUPS_TO_BLOCKS(fs->super, groups);
2380         last_start = 0;
2381         for (grp = 0; grp < flex_groups; grp++) {
2382                 overhead = calc_group_overhead(fs, grp, old_desc_blocks);
2383
2384                 /*
2385                  * we want to keep track of how much data we can store in
2386                  * the groups leading up to the last group so we can determine
2387                  * how big the last group needs to be
2388                  */
2389                 if (grp < (groups - 1))
2390                         last_start += EXT2_BLOCKS_PER_GROUP(fs->super) -
2391                                 overhead;
2392
2393                 if (data_blocks > overhead)
2394                         data_blocks -= overhead;
2395                 else
2396                         data_blocks = 0;
2397         }
2398 #ifdef RESIZE2FS_DEBUG
2399         if (flags & RESIZE_DEBUG_MIN_CALC)
2400                 printf("With %d group(s), we have %llu blocks available.\n",
2401                        groups, data_blocks);
2402 #endif
2403
2404         /*
2405          * if we need more group descriptors in order to accomodate our data
2406          * then we need to add them here
2407          */
2408         blks_needed = data_needed;
2409         while (blks_needed > data_blocks) {
2410                 blk64_t remainder = blks_needed - data_blocks;
2411                 dgrp_t extra_grps;
2412
2413                 /* figure out how many more groups we need for the data */
2414                 extra_grps = ext2fs_div64_ceil(remainder,
2415                                                EXT2_BLOCKS_PER_GROUP(fs->super));
2416
2417                 data_blocks += EXT2_GROUPS_TO_BLOCKS(fs->super, extra_grps);
2418
2419                 /* ok we have to account for the last group */
2420                 overhead = calc_group_overhead(fs, groups-1, old_desc_blocks);
2421                 last_start += EXT2_BLOCKS_PER_GROUP(fs->super) - overhead;
2422
2423                 grp = flex_groups;
2424                 groups += extra_grps;
2425                 if (!(fs->super->s_feature_incompat &
2426                       EXT4_FEATURE_INCOMPAT_FLEX_BG))
2427                         flex_groups = groups;
2428                 else if (groups > flex_groups) {
2429                         dgrp_t r = groups & (flexbg_size - 1);
2430
2431                         flex_groups = groups + flexbg_size - r;
2432                         if (flex_groups > fs->group_desc_count)
2433                                 flex_groups = fs->group_desc_count;
2434                 }
2435
2436                 for (; grp < flex_groups; grp++) {
2437                         overhead = calc_group_overhead(fs, grp,
2438                                                        old_desc_blocks);
2439
2440                         /*
2441                          * again, we need to see how much data we cram into
2442                          * all of the groups leading up to the last group
2443                          */
2444                         if (grp < groups - 1)
2445                                 last_start += EXT2_BLOCKS_PER_GROUP(fs->super)
2446                                         - overhead;
2447
2448                         data_blocks -= overhead;
2449                 }
2450
2451 #ifdef RESIZE2FS_DEBUG
2452                 if (flags & RESIZE_DEBUG_MIN_CALC)
2453                         printf("Added %d extra group(s), "
2454                                "blks_needed %llu, data_blocks %llu, "
2455                                "last_start %llu\n", extra_grps, blks_needed,
2456                                data_blocks, last_start);
2457 #endif
2458         }
2459
2460         /* now for the fun voodoo */
2461         grp = groups - 1;
2462         if ((fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_FLEX_BG) &&
2463             (grp & ~(flexbg_size - 1)) == 0)
2464                 grp = grp & ~(flexbg_size - 1);
2465         overhead = 0;
2466         for (; grp < flex_groups; grp++)
2467                 overhead += calc_group_overhead(fs, grp, old_desc_blocks);
2468
2469 #ifdef RESIZE2FS_DEBUG
2470         if (flags & RESIZE_DEBUG_MIN_CALC)
2471                 printf("Last group's overhead is %llu\n", overhead);
2472 #endif
2473
2474         /*
2475          * if this is the case then the last group is going to have data in it
2476          * so we need to adjust the size of the last group accordingly
2477          */
2478         if (last_start < blks_needed) {
2479                 blk64_t remainder = blks_needed - last_start;
2480
2481 #ifdef RESIZE2FS_DEBUG
2482                 if (flags & RESIZE_DEBUG_MIN_CALC)
2483                         printf("Need %llu data blocks in last group\n",
2484                                remainder);
2485 #endif
2486                 /*
2487                  * 50 is a magic number that mkfs/resize uses to see if its
2488                  * even worth making/resizing the fs.  basically you need to
2489                  * have at least 50 blocks in addition to the blocks needed
2490                  * for the metadata in the last group
2491                  */
2492                 if (remainder > 50)
2493                         overhead += remainder;
2494                 else
2495                         overhead += 50;
2496         } else
2497                 overhead += 50;
2498
2499         overhead += fs->super->s_first_data_block;
2500 #ifdef RESIZE2FS_DEBUG
2501         if (flags & RESIZE_DEBUG_MIN_CALC)
2502                 printf("Final size of last group is %lld\n", overhead);
2503 #endif
2504
2505         /* Add extra slack for bigalloc file systems */
2506         if (EXT2FS_CLUSTER_RATIO(fs) > 1)
2507                 overhead += EXT2FS_CLUSTER_RATIO(fs) * 2;
2508
2509         /*
2510          * since our last group doesn't have to be BLOCKS_PER_GROUP
2511          * large, we only do groups-1, and then add the number of
2512          * blocks needed to handle the group descriptor metadata+data
2513          * that we need
2514          */
2515         blks_needed = EXT2_GROUPS_TO_BLOCKS(fs->super, groups - 1);
2516         blks_needed += overhead;
2517
2518         /*
2519          * Make sure blks_needed covers the end of the inode table in
2520          * the last block group.
2521          */
2522         overhead = ext2fs_inode_table_loc(fs, groups-1) +
2523                 fs->inode_blocks_per_group;
2524         if (blks_needed < overhead)
2525                 blks_needed = overhead;
2526
2527 #ifdef RESIZE2FS_DEBUG
2528         if (flags & RESIZE_DEBUG_MIN_CALC)
2529                 printf("Estimated blocks needed: %llu\n", blks_needed);
2530 #endif
2531
2532         /*
2533          * If at this point we've already added up more "needed" than
2534          * the current size, just return current size as minimum.
2535          */
2536         if (blks_needed >= ext2fs_blocks_count(fs->super))
2537                 return ext2fs_blocks_count(fs->super);
2538         /*
2539          * We need to reserve a few extra blocks if extents are
2540          * enabled, in case we need to grow the extent tree.  The more
2541          * we shrink the file system, the more space we need.
2542          *
2543          * The absolute worst case is every single data block is in
2544          * the part of the file system that needs to be evacuated,
2545          * with each data block needs to be in its own extent, and
2546          * with each inode needing at least one extent block.
2547          */
2548         if (fs->super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_EXTENTS) {
2549                 blk64_t safe_margin = (ext2fs_blocks_count(fs->super) -
2550                                        blks_needed)/500;
2551                 unsigned int exts_per_blk = (fs->blocksize /
2552                                              sizeof(struct ext3_extent)) - 1;
2553                 blk64_t worst_case = ((data_needed + exts_per_blk - 1) /
2554                                       exts_per_blk);
2555
2556                 if (worst_case < inode_count)
2557                         worst_case = inode_count;
2558
2559                 if (safe_margin > worst_case)
2560                         safe_margin = worst_case;
2561
2562 #ifdef RESIZE2FS_DEBUG
2563                 if (flags & RESIZE_DEBUG_MIN_CALC)
2564                         printf("Extents safety margin: %llu\n", safe_margin);
2565 #endif
2566                 blks_needed += safe_margin;
2567         }
2568
2569         return blks_needed;
2570 }