resize/resize2fs.c

   1 /*
   2  * resize2fs.c --- ext2 main routine
   3  *
   4  * Copyright (C) 1997, 1998 by Theodore Ts'o and
   5  *      PowerQuest, Inc.
   6  *
   7  * Copyright (C) 1999, 2000 by Theosore Ts'o
   8  *
   9  * %Begin-Header%
  10  * This file may be redistributed under the terms of the GNU Public
  11  * License.
  12  * %End-Header%
  13  */
  14
  15 /*
  16  * Resizing a filesystem consists of the following phases:
  17  *
  18  *      1.  Adjust superblock and write out new parts of the inode
  19  *              table
  20  *      2.  Determine blocks which need to be relocated, and copy the
  21  *              contents of blocks from their old locations to the new ones.
  22  *      3.  Scan the inode table, doing the following:
  23  *              a.  If blocks have been moved, update the block
  24  *                      pointers in the inodes and indirect blocks to
  25  *                      point at the new block locations.
  26  *              b.  If parts of the inode table need to be evacuated,
  27  *                      copy inodes from their old locations to their
  28  *                      new ones.
  29  *              c.  If (b) needs to be done, note which blocks contain
  30  *                      directory information, since we will need to
  31  *                      update the directory information.
  32  *      4.  Update the directory blocks with the new inode locations.
  33  *      5.  Move the inode tables, if necessary.
  34  */
  35
  36 #include "config.h"
  37 #include "resize2fs.h"
  38 #include <time.h>
  39
  40 #ifdef __linux__                        /* Kludge for debugging */
  41 #define RESIZE2FS_DEBUG
  42 #endif
  43
  44 static void fix_uninit_block_bitmaps(ext2_filsys fs);
  45 static errcode_t adjust_superblock(ext2_resize_t rfs, blk64_t new_size);
  46 static errcode_t blocks_to_move(ext2_resize_t rfs);
  47 static errcode_t block_mover(ext2_resize_t rfs);
  48 static errcode_t inode_scan_and_fix(ext2_resize_t rfs);
  49 static errcode_t inode_ref_fix(ext2_resize_t rfs);
  50 static errcode_t move_itables(ext2_resize_t rfs);
  51 static errcode_t fix_resize_inode(ext2_filsys fs);
  52 static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs);
  53 static errcode_t fix_sb_journal_backup(ext2_filsys fs);
  54
  55 /*
  56  * Some helper CPP macros
  57  */
  58 #define IS_BLOCK_BM(fs, i, blk) ((blk) == ext2fs_block_bitmap_loc((fs),(i)))
  59 #define IS_INODE_BM(fs, i, blk) ((blk) == ext2fs_inode_bitmap_loc((fs),(i)))
  60
  61 #define IS_INODE_TB(fs, i, blk) (((blk) >= ext2fs_inode_table_loc((fs), (i))) && \
  62                                  ((blk) < (ext2fs_inode_table_loc((fs), (i)) + \
  63                                            (fs)->inode_blocks_per_group)))
  64
  65 /* Some bigalloc helper macros which are more succint... */
  66 #define B2C(x)  EXT2FS_B2C(fs, (x))
  67 #define C2B(x)  EXT2FS_C2B(fs, (x))
  68 #define EQ_CLSTR(x, y) (B2C(x) == B2C(y))
  69 #define LE_CLSTR(x, y) (B2C(x) <= B2C(y))
  70 #define LT_CLSTR(x, y) (B2C(x) <  B2C(y))
  71 #define GE_CLSTR(x, y) (B2C(x) >= B2C(y))
  72 #define GT_CLSTR(x, y) (B2C(x) >  B2C(y))
  73
  74 int lazy_itable_init;
  75
  76 /*
  77  * This is the top-level routine which does the dirty deed....
  78  */
  79 errcode_t resize_fs(ext2_filsys fs, blk64_t *new_size, int flags,
  80             errcode_t (*progress)(ext2_resize_t rfs, int pass,
  81                                           unsigned long cur,
  82                                           unsigned long max_val))
  83 {
  84         ext2_resize_t   rfs;
  85         errcode_t       retval;
  86         struct resource_track   rtrack, overall_track;
  87
  88         /*
  89          * Create the data structure
  90          */
  91         retval = ext2fs_get_mem(sizeof(struct ext2_resize_struct), &rfs);
  92         if (retval)
  93                 return retval;
  94
  95         memset(rfs, 0, sizeof(struct ext2_resize_struct));
  96         fs->priv_data = rfs;
  97         rfs->old_fs = fs;
  98         rfs->flags = flags;
  99         rfs->itable_buf  = 0;
 100         rfs->progress = progress;
 101
 102         init_resource_track(&overall_track, "overall resize2fs", fs->io);
 103         init_resource_track(&rtrack, "read_bitmaps", fs->io);
 104         retval = ext2fs_read_bitmaps(fs);
 105         if (retval)
 106                 goto errout;
 107         print_resource_track(rfs, &rtrack, fs->io);
 108
 109         fs->super->s_state |= EXT2_ERROR_FS;
 110         ext2fs_mark_super_dirty(fs);
 111         ext2fs_flush(fs);
 112
 113         init_resource_track(&rtrack, "fix_uninit_block_bitmaps 1", fs->io);
 114         fix_uninit_block_bitmaps(fs);
 115         print_resource_track(rfs, &rtrack, fs->io);
 116         retval = ext2fs_dup_handle(fs, &rfs->new_fs);
 117         if (retval)
 118                 goto errout;
 119
 120         init_resource_track(&rtrack, "adjust_superblock", fs->io);
 121         retval = adjust_superblock(rfs, *new_size);
 122         if (retval)
 123                 goto errout;
 124         print_resource_track(rfs, &rtrack, fs->io);
 125
 126
 127         init_resource_track(&rtrack, "fix_uninit_block_bitmaps 2", fs->io);
 128         fix_uninit_block_bitmaps(rfs->new_fs);
 129         print_resource_track(rfs, &rtrack, fs->io);
 130         /* Clear the block bitmap uninit flag for the last block group */
 131         ext2fs_bg_flags_clear(rfs->new_fs, rfs->new_fs->group_desc_count - 1,
 132                              EXT2_BG_BLOCK_UNINIT);
 133
 134         *new_size = ext2fs_blocks_count(rfs->new_fs->super);
 135
 136         init_resource_track(&rtrack, "blocks_to_move", fs->io);
 137         retval = blocks_to_move(rfs);
 138         if (retval)
 139                 goto errout;
 140         print_resource_track(rfs, &rtrack, fs->io);
 141
 142 #ifdef RESIZE2FS_DEBUG
 143         if (rfs->flags & RESIZE_DEBUG_BMOVE)
 144                 printf("Number of free blocks: %llu/%llu, Needed: %llu\n",
 145                        ext2fs_free_blocks_count(rfs->old_fs->super),
 146                        ext2fs_free_blocks_count(rfs->new_fs->super),
 147                        rfs->needed_blocks);
 148 #endif
 149
 150         init_resource_track(&rtrack, "block_mover", fs->io);
 151         retval = block_mover(rfs);
 152         if (retval)
 153                 goto errout;
 154         print_resource_track(rfs, &rtrack, fs->io);
 155
 156         init_resource_track(&rtrack, "inode_scan_and_fix", fs->io);
 157         retval = inode_scan_and_fix(rfs);
 158         if (retval)
 159                 goto errout;
 160         print_resource_track(rfs, &rtrack, fs->io);
 161
 162         init_resource_track(&rtrack, "inode_ref_fix", fs->io);
 163         retval = inode_ref_fix(rfs);
 164         if (retval)
 165                 goto errout;
 166         print_resource_track(rfs, &rtrack, fs->io);
 167
 168         init_resource_track(&rtrack, "move_itables", fs->io);
 169         retval = move_itables(rfs);
 170         if (retval)
 171                 goto errout;
 172         print_resource_track(rfs, &rtrack, fs->io);
 173
 174         init_resource_track(&rtrack, "calculate_summary_stats", fs->io);
 175         retval = ext2fs_calculate_summary_stats(rfs->new_fs);
 176         if (retval)
 177                 goto errout;
 178         print_resource_track(rfs, &rtrack, fs->io);
 179
 180         init_resource_track(&rtrack, "fix_resize_inode", fs->io);
 181         retval = fix_resize_inode(rfs->new_fs);
 182         if (retval)
 183                 goto errout;
 184         print_resource_track(rfs, &rtrack, fs->io);
 185
 186         init_resource_track(&rtrack, "fix_sb_journal_backup", fs->io);
 187         retval = fix_sb_journal_backup(rfs->new_fs);
 188         if (retval)
 189                 goto errout;
 190         print_resource_track(rfs, &rtrack, fs->io);
 191
 192         rfs->new_fs->super->s_state &= ~EXT2_ERROR_FS;
 193         rfs->new_fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
 194
 195         print_resource_track(rfs, &overall_track, fs->io);
 196         retval = ext2fs_close(rfs->new_fs);
 197         if (retval)
 198                 goto errout;
 199
 200         rfs->flags = flags;
 201
 202         ext2fs_free(rfs->old_fs);
 203         if (rfs->itable_buf)
 204                 ext2fs_free_mem(&rfs->itable_buf);
 205         if (rfs->reserve_blocks)
 206                 ext2fs_free_block_bitmap(rfs->reserve_blocks);
 207         if (rfs->move_blocks)
 208                 ext2fs_free_block_bitmap(rfs->move_blocks);
 209         ext2fs_free_mem(&rfs);
 210
 211         return 0;
 212
 213 errout:
 214         if (rfs->new_fs)
 215                 ext2fs_free(rfs->new_fs);
 216         if (rfs->itable_buf)
 217                 ext2fs_free_mem(&rfs->itable_buf);
 218         ext2fs_free_mem(&rfs);
 219         return retval;
 220 }
 221
 222 /*
 223  * Clean up the bitmaps for unitialized bitmaps
 224  */
 225 static void fix_uninit_block_bitmaps(ext2_filsys fs)
 226 {
 227         blk64_t         blk, lblk;
 228         dgrp_t          g;
 229         int             i;
 230
 231         if (!(EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 232                                          EXT4_FEATURE_RO_COMPAT_GDT_CSUM)))
 233                 return;
 234
 235         for (g=0; g < fs->group_desc_count; g++) {
 236                 if (!(ext2fs_bg_flags_test(fs, g, EXT2_BG_BLOCK_UNINIT)))
 237                         continue;
 238
 239                 blk = ext2fs_group_first_block2(fs, g);
 240                 lblk = ext2fs_group_last_block2(fs, g);
 241                 ext2fs_unmark_block_bitmap_range2(fs->block_map, blk,
 242                                                   lblk - blk + 1);
 243
 244                 ext2fs_reserve_super_and_bgd(fs, g, fs->block_map);
 245                 ext2fs_mark_block_bitmap2(fs->block_map,
 246                                           ext2fs_block_bitmap_loc(fs, g));
 247                 ext2fs_mark_block_bitmap2(fs->block_map,
 248                                           ext2fs_inode_bitmap_loc(fs, g));
 249                 for (i = 0, blk = ext2fs_inode_table_loc(fs, g);
 250                      i < (unsigned int) fs->inode_blocks_per_group;
 251                      i++, blk++)
 252                         ext2fs_mark_block_bitmap2(fs->block_map, blk);
 253         }
 254 }
 255
 256 /* --------------------------------------------------------------------
 257  *
 258  * Resize processing, phase 1.
 259  *
 260  * In this phase we adjust the in-memory superblock information, and
 261  * initialize any new parts of the inode table.  The new parts of the
 262  * inode table are created in virgin disk space, so we can abort here
 263  * without any side effects.
 264  * --------------------------------------------------------------------
 265  */
 266
 267 /*
 268  * If the group descriptor's bitmap and inode table blocks are valid,
 269  * release them in the new filesystem data structure, and mark them as
 270  * reserved so the old inode table blocks don't get overwritten.
 271  */
 272 static void free_gdp_blocks(ext2_filsys fs,
 273                             ext2fs_block_bitmap reserve_blocks,
 274                             struct ext2_group_desc *gdp)
 275 {
 276         blk_t   blk;
 277         int     j;
 278
 279         if (gdp->bg_block_bitmap &&
 280             (gdp->bg_block_bitmap < ext2fs_blocks_count(fs->super))) {
 281                 ext2fs_block_alloc_stats(fs, gdp->bg_block_bitmap, -1);
 282                 ext2fs_mark_block_bitmap2(reserve_blocks,
 283                                          gdp->bg_block_bitmap);
 284         }
 285
 286         if (gdp->bg_inode_bitmap &&
 287             (gdp->bg_inode_bitmap < ext2fs_blocks_count(fs->super))) {
 288                 ext2fs_block_alloc_stats(fs, gdp->bg_inode_bitmap, -1);
 289                 ext2fs_mark_block_bitmap2(reserve_blocks,
 290                                          gdp->bg_inode_bitmap);
 291         }
 292
 293         if (gdp->bg_inode_table == 0 ||
 294             (gdp->bg_inode_table >= ext2fs_blocks_count(fs->super)))
 295                 return;
 296
 297         for (blk = gdp->bg_inode_table, j = 0;
 298              j < fs->inode_blocks_per_group; j++, blk++) {
 299                 if (blk >= ext2fs_blocks_count(fs->super))
 300                         break;
 301                 ext2fs_block_alloc_stats(fs, blk, -1);
 302                 ext2fs_mark_block_bitmap2(reserve_blocks, blk);
 303         }
 304 }
 305
 306 /*
 307  * This routine is shared by the online and offline resize routines.
 308  * All of the information which is adjusted in memory is done here.
 309  *
 310  * The reserve_blocks parameter is only needed when shrinking the
 311  * filesystem.
 312  */
 313 errcode_t adjust_fs_info(ext2_filsys fs, ext2_filsys old_fs,
 314                          ext2fs_block_bitmap reserve_blocks, blk64_t new_size)
 315 {
 316         errcode_t       retval;
 317         blk64_t         overhead = 0;
 318         blk64_t         rem;
 319         blk64_t         blk, group_block;
 320         blk64_t         real_end;
 321         blk64_t         old_numblocks, numblocks, adjblocks;
 322         unsigned long   i, j, old_desc_blocks;
 323         unsigned int    meta_bg, meta_bg_size;
 324         int             has_super, csum_flag;
 325         unsigned long long new_inodes;  /* u64 to check for overflow */
 326         double          percent;
 327
 328         ext2fs_blocks_count_set(fs->super, new_size);
 329
 330 retry:
 331         fs->group_desc_count = ext2fs_div64_ceil(ext2fs_blocks_count(fs->super) -
 332                                        fs->super->s_first_data_block,
 333                                        EXT2_BLOCKS_PER_GROUP(fs->super));
 334         if (fs->group_desc_count == 0)
 335                 return EXT2_ET_TOOSMALL;
 336         fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count,
 337                                           EXT2_DESC_PER_BLOCK(fs->super));
 338
 339         /*
 340          * Overhead is the number of bookkeeping blocks per group.  It
 341          * includes the superblock backup, the group descriptor
 342          * backups, the inode bitmap, the block bitmap, and the inode
 343          * table.
 344          */
 345         overhead = (int) (2 + fs->inode_blocks_per_group);
 346
 347         if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1))
 348                 overhead += 1 + fs->desc_blocks +
 349                         fs->super->s_reserved_gdt_blocks;
 350
 351         /*
 352          * See if the last group is big enough to support the
 353          * necessary data structures.  If not, we need to get rid of
 354          * it.
 355          */
 356         rem = (ext2fs_blocks_count(fs->super) - fs->super->s_first_data_block) %
 357                 fs->super->s_blocks_per_group;
 358         if ((fs->group_desc_count == 1) && rem && (rem < overhead))
 359                 return EXT2_ET_TOOSMALL;
 360         if ((fs->group_desc_count > 1) && rem && (rem < overhead+50)) {
 361                 ext2fs_blocks_count_set(fs->super,
 362                                         ext2fs_blocks_count(fs->super) - rem);
 363                 goto retry;
 364         }
 365         /*
 366          * Adjust the number of inodes
 367          */
 368         new_inodes =(unsigned long long) fs->super->s_inodes_per_group * fs->group_desc_count;
 369         if (new_inodes > ~0U) {
 370                 fprintf(stderr, _("inodes (%llu) must be less than %u"),
 371                                    new_inodes, ~0U);
 372                 return EXT2_ET_TOO_MANY_INODES;
 373         }
 374         fs->super->s_inodes_count = fs->super->s_inodes_per_group *
 375                 fs->group_desc_count;
 376
 377         /*
 378          * Adjust the number of free blocks
 379          */
 380         blk = ext2fs_blocks_count(old_fs->super);
 381         if (blk > ext2fs_blocks_count(fs->super))
 382                 ext2fs_free_blocks_count_set(fs->super,
 383                         ext2fs_free_blocks_count(fs->super) -
 384                         (blk - ext2fs_blocks_count(fs->super)));
 385         else
 386                 ext2fs_free_blocks_count_set(fs->super,
 387                         ext2fs_free_blocks_count(fs->super) +
 388                         (ext2fs_blocks_count(fs->super) - blk));
 389
 390         /*
 391          * Adjust the number of reserved blocks
 392          */
 393         percent = (ext2fs_r_blocks_count(old_fs->super) * 100.0) /
 394                 ext2fs_blocks_count(old_fs->super);
 395         ext2fs_r_blocks_count_set(fs->super,
 396                                   (percent * ext2fs_blocks_count(fs->super) /
 397                                    100.0));
 398
 399         /*
 400          * Adjust the bitmaps for size
 401          */
 402         retval = ext2fs_resize_inode_bitmap2(fs->super->s_inodes_count,
 403                                             fs->super->s_inodes_count,
 404                                             fs->inode_map);
 405         if (retval) goto errout;
 406
 407         real_end = (((blk64_t) EXT2_BLOCKS_PER_GROUP(fs->super) *
 408                      fs->group_desc_count)) - 1 +
 409                 fs->super->s_first_data_block;
 410         retval = ext2fs_resize_block_bitmap2(ext2fs_blocks_count(fs->super)-1,
 411                                             real_end, fs->block_map);
 412
 413         if (retval) goto errout;
 414
 415         /*
 416          * Reallocate the group descriptors as necessary.
 417          */
 418         if (old_fs->desc_blocks != fs->desc_blocks) {
 419                 retval = ext2fs_resize_mem(old_fs->desc_blocks *
 420                                            fs->blocksize,
 421                                            fs->desc_blocks * fs->blocksize,
 422                                            &fs->group_desc);
 423                 if (retval)
 424                         goto errout;
 425                 if (fs->desc_blocks > old_fs->desc_blocks)
 426                         memset((char *) fs->group_desc +
 427                                (old_fs->desc_blocks * fs->blocksize), 0,
 428                                (fs->desc_blocks - old_fs->desc_blocks) *
 429                                fs->blocksize);
 430         }
 431
 432         /*
 433          * If the resize_inode feature is set, and we are changing the
 434          * number of descriptor blocks, then adjust
 435          * s_reserved_gdt_blocks if possible to avoid needing to move
 436          * the inode table either now or in the future.
 437          */
 438         if ((fs->super->s_feature_compat &
 439              EXT2_FEATURE_COMPAT_RESIZE_INODE) &&
 440             (old_fs->desc_blocks != fs->desc_blocks)) {
 441                 int new;
 442
 443                 new = ((int) fs->super->s_reserved_gdt_blocks) +
 444                         (old_fs->desc_blocks - fs->desc_blocks);
 445                 if (new < 0)
 446                         new = 0;
 447                 if (new > (int) fs->blocksize/4)
 448                         new = fs->blocksize/4;
 449                 fs->super->s_reserved_gdt_blocks = new;
 450         }
 451
 452         /*
 453          * If we are shrinking the number of block groups, we're done
 454          * and can exit now.
 455          */
 456         if (old_fs->group_desc_count > fs->group_desc_count) {
 457                 /*
 458                  * Check the block groups that we are chopping off
 459                  * and free any blocks associated with their metadata
 460                  */
 461                 for (i = fs->group_desc_count;
 462                      i < old_fs->group_desc_count; i++) {
 463                         free_gdp_blocks(fs, reserve_blocks,
 464                                         ext2fs_group_desc(old_fs,
 465                                                 old_fs->group_desc, i));
 466                 }
 467                 retval = 0;
 468                 goto errout;
 469         }
 470
 471         /*
 472          * Fix the count of the last (old) block group
 473          */
 474         old_numblocks = (ext2fs_blocks_count(old_fs->super) -
 475                          old_fs->super->s_first_data_block) %
 476                                  old_fs->super->s_blocks_per_group;
 477         if (!old_numblocks)
 478                 old_numblocks = old_fs->super->s_blocks_per_group;
 479         if (old_fs->group_desc_count == fs->group_desc_count) {
 480                 numblocks = (ext2fs_blocks_count(fs->super) -
 481                              fs->super->s_first_data_block) %
 482                         fs->super->s_blocks_per_group;
 483                 if (!numblocks)
 484                         numblocks = fs->super->s_blocks_per_group;
 485         } else
 486                 numblocks = fs->super->s_blocks_per_group;
 487         i = old_fs->group_desc_count - 1;
 488         ext2fs_bg_free_blocks_count_set(fs, i, ext2fs_bg_free_blocks_count(fs, i) + (numblocks - old_numblocks));
 489         ext2fs_group_desc_csum_set(fs, i);
 490
 491         /*
 492          * If the number of block groups is staying the same, we're
 493          * done and can exit now.  (If the number block groups is
 494          * shrinking, we had exited earlier.)
 495          */
 496         if (old_fs->group_desc_count >= fs->group_desc_count) {
 497                 retval = 0;
 498                 goto errout;
 499         }
 500
 501         /*
 502          * Initialize the new block group descriptors
 503          */
 504         group_block = ext2fs_group_first_block2(fs,
 505                                                 old_fs->group_desc_count);
 506         csum_flag = EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 507                                                EXT4_FEATURE_RO_COMPAT_GDT_CSUM);
 508         if (access("/sys/fs/ext4/features/lazy_itable_init", F_OK) == 0)
 509                 lazy_itable_init = 1;
 510         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
 511                 old_desc_blocks = fs->super->s_first_meta_bg;
 512         else
 513                 old_desc_blocks = fs->desc_blocks +
 514                         fs->super->s_reserved_gdt_blocks;
 515         for (i = old_fs->group_desc_count;
 516              i < fs->group_desc_count; i++) {
 517                 memset(ext2fs_group_desc(fs, fs->group_desc, i), 0,
 518                        sizeof(struct ext2_group_desc));
 519                 adjblocks = 0;
 520
 521                 ext2fs_bg_flags_zap(fs, i);
 522                 if (csum_flag) {
 523                         ext2fs_bg_flags_set(fs, i, EXT2_BG_INODE_UNINIT);
 524                         if (!lazy_itable_init)
 525                                 ext2fs_bg_flags_set(fs, i,
 526                                                     EXT2_BG_INODE_ZEROED);
 527                         ext2fs_bg_itable_unused_set(fs, i,
 528                                         fs->super->s_inodes_per_group);
 529                 }
 530
 531                 numblocks = ext2fs_group_blocks_count(fs, i);
 532                 if ((i < fs->group_desc_count - 1) && csum_flag)
 533                         ext2fs_bg_flags_set(fs, i, EXT2_BG_BLOCK_UNINIT);
 534
 535                 has_super = ext2fs_bg_has_super(fs, i);
 536                 if (has_super) {
 537                         ext2fs_block_alloc_stats2(fs, group_block, +1);
 538                         adjblocks++;
 539                 }
 540                 meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
 541                 meta_bg = i / meta_bg_size;
 542                 if (!(fs->super->s_feature_incompat &
 543                       EXT2_FEATURE_INCOMPAT_META_BG) ||
 544                     (meta_bg < fs->super->s_first_meta_bg)) {
 545                         if (has_super) {
 546                                 for (j=0; j < old_desc_blocks; j++)
 547                                         ext2fs_block_alloc_stats2(fs,
 548                                                  group_block + 1 + j, +1);
 549                                 adjblocks += old_desc_blocks;
 550                         }
 551                 } else {
 552                         if (has_super)
 553                                 has_super = 1;
 554                         if (((i % meta_bg_size) == 0) ||
 555                             ((i % meta_bg_size) == 1) ||
 556                             ((i % meta_bg_size) == (meta_bg_size-1)))
 557                                 ext2fs_block_alloc_stats2(fs,
 558                                                  group_block + has_super, +1);
 559                 }
 560
 561                 adjblocks += 2 + fs->inode_blocks_per_group;
 562
 563                 numblocks -= adjblocks;
 564                 ext2fs_free_blocks_count_set(fs->super,
 565                              ext2fs_free_blocks_count(fs->super) - adjblocks);
 566                 fs->super->s_free_inodes_count +=
 567                         fs->super->s_inodes_per_group;
 568                 ext2fs_bg_free_blocks_count_set(fs, i, numblocks);
 569                 ext2fs_bg_free_inodes_count_set(fs, i,
 570                                                 fs->super->s_inodes_per_group);
 571                 ext2fs_bg_used_dirs_count_set(fs, i, 0);
 572                 ext2fs_group_desc_csum_set(fs, i);
 573
 574                 retval = ext2fs_allocate_group_table(fs, i, 0);
 575                 if (retval) goto errout;
 576
 577                 group_block += fs->super->s_blocks_per_group;
 578         }
 579         retval = 0;
 580
 581 errout:
 582         return (retval);
 583 }
 584
 585 /*
 586  * This routine adjusts the superblock and other data structures, both
 587  * in disk as well as in memory...
 588  */
 589 static errcode_t adjust_superblock(ext2_resize_t rfs, blk64_t new_size)
 590 {
 591         ext2_filsys fs;
 592         int             adj = 0;
 593         errcode_t       retval;
 594         blk64_t         group_block;
 595         unsigned long   i;
 596         unsigned long   max_group;
 597
 598         fs = rfs->new_fs;
 599         ext2fs_mark_super_dirty(fs);
 600         ext2fs_mark_bb_dirty(fs);
 601         ext2fs_mark_ib_dirty(fs);
 602
 603         retval = ext2fs_allocate_block_bitmap(fs, _("reserved blocks"),
 604                                               &rfs->reserve_blocks);
 605         if (retval)
 606                 return retval;
 607
 608         retval = adjust_fs_info(fs, rfs->old_fs, rfs->reserve_blocks, new_size);
 609         if (retval)
 610                 goto errout;
 611
 612         /*
 613          * Check to make sure there are enough inodes
 614          */
 615         if ((rfs->old_fs->super->s_inodes_count -
 616              rfs->old_fs->super->s_free_inodes_count) >
 617             rfs->new_fs->super->s_inodes_count) {
 618                 retval = ENOSPC;
 619                 goto errout;
 620         }
 621
 622         /*
 623          * If we are shrinking the number block groups, we're done and
 624          * can exit now.
 625          */
 626         if (rfs->old_fs->group_desc_count > fs->group_desc_count) {
 627                 retval = 0;
 628                 goto errout;
 629         }
 630
 631         /*
 632          * If the number of block groups is staying the same, we're
 633          * done and can exit now.  (If the number block groups is
 634          * shrinking, we had exited earlier.)
 635          */
 636         if (rfs->old_fs->group_desc_count >= fs->group_desc_count) {
 637                 retval = 0;
 638                 goto errout;
 639         }
 640
 641         /*
 642          * If we are using uninit_bg (aka GDT_CSUM) and the kernel
 643          * supports lazy inode initialization, we can skip
 644          * initializing the inode table.
 645          */
 646         if (lazy_itable_init &&
 647             EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 648                                        EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
 649                 retval = 0;
 650                 goto errout;
 651         }
 652
 653         /*
 654          * Initialize the inode table
 655          */
 656         retval = ext2fs_get_array(fs->blocksize, fs->inode_blocks_per_group,
 657                                 &rfs->itable_buf);
 658         if (retval)
 659                 goto errout;
 660
 661         memset(rfs->itable_buf, 0, fs->blocksize * fs->inode_blocks_per_group);
 662         group_block = ext2fs_group_first_block2(fs,
 663                                                 rfs->old_fs->group_desc_count);
 664         adj = rfs->old_fs->group_desc_count;
 665         max_group = fs->group_desc_count - adj;
 666         if (rfs->progress) {
 667                 retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
 668                                        0, max_group);
 669                 if (retval)
 670                         goto errout;
 671         }
 672         for (i = rfs->old_fs->group_desc_count;
 673              i < fs->group_desc_count; i++) {
 674                 /*
 675                  * Write out the new inode table
 676                  */
 677                 retval = io_channel_write_blk64(fs->io,
 678                                                 ext2fs_inode_table_loc(fs, i),
 679                                                 fs->inode_blocks_per_group,
 680                                                 rfs->itable_buf);
 681                 if (retval) goto errout;
 682
 683                 io_channel_flush(fs->io);
 684                 if (rfs->progress) {
 685                         retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
 686                                                i - adj + 1, max_group);
 687                         if (retval)
 688                                 goto errout;
 689                 }
 690                 group_block += fs->super->s_blocks_per_group;
 691         }
 692         io_channel_flush(fs->io);
 693         retval = 0;
 694
 695 errout:
 696         return retval;
 697 }
 698
 699 /* --------------------------------------------------------------------
 700  *
 701  * Resize processing, phase 2.
 702  *
 703  * In this phase we adjust determine which blocks need to be moved, in
 704  * blocks_to_move().  We then copy the blocks to their ultimate new
 705  * destinations using block_mover().  Since we are copying blocks to
 706  * their new locations, again during this pass we can abort without
 707  * any problems.
 708  * --------------------------------------------------------------------
 709  */
 710
 711 /*
 712  * This helper function creates a block bitmap with all of the
 713  * filesystem meta-data blocks.
 714  */
 715 static errcode_t mark_table_blocks(ext2_filsys fs,
 716                                    ext2fs_block_bitmap bmap)
 717 {
 718         dgrp_t                  i;
 719
 720         for (i = 0; i < fs->group_desc_count; i++) {
 721                 ext2fs_reserve_super_and_bgd(fs, i, bmap);
 722
 723                 /*
 724                  * Mark the blocks used for the inode table
 725                  */
 726                 ext2fs_mark_block_bitmap_range2(bmap,
 727                                           ext2fs_inode_table_loc(fs, i),
 728                                           fs->inode_blocks_per_group);
 729
 730                 /*
 731                  * Mark block used for the block bitmap
 732                  */
 733                 ext2fs_mark_block_bitmap2(bmap,
 734                                          ext2fs_block_bitmap_loc(fs, i));
 735
 736                 /*
 737                  * Mark block used for the inode bitmap
 738                  */
 739                 ext2fs_mark_block_bitmap2(bmap,
 740                                          ext2fs_inode_bitmap_loc(fs, i));
 741         }
 742         return 0;
 743 }
 744
 745 /*
 746  * This function checks to see if a particular block (either a
 747  * superblock or a block group descriptor) overlaps with an inode or
 748  * block bitmap block, or with the inode table.
 749  */
 750 static void mark_fs_metablock(ext2_resize_t rfs,
 751                               ext2fs_block_bitmap meta_bmap,
 752                               int group, blk64_t blk)
 753 {
 754         ext2_filsys     fs = rfs->new_fs;
 755
 756         ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
 757         ext2fs_block_alloc_stats2(fs, blk, +1);
 758
 759         /*
 760          * Check to see if we overlap with the inode or block bitmap,
 761          * or the inode tables.  If not, and the block is in use, then
 762          * mark it as a block to be moved.
 763          */
 764         if (IS_BLOCK_BM(fs, group, blk)) {
 765                 ext2fs_block_bitmap_loc_set(fs, group, 0);
 766                 rfs->needed_blocks++;
 767                 return;
 768         }
 769         if (IS_INODE_BM(fs, group, blk)) {
 770                 ext2fs_inode_bitmap_loc_set(fs, group, 0);
 771                 rfs->needed_blocks++;
 772                 return;
 773         }
 774         if (IS_INODE_TB(fs, group, blk)) {
 775                 ext2fs_inode_table_loc_set(fs, group, 0);
 776                 rfs->needed_blocks++;
 777                 return;
 778         }
 779         if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_FLEX_BG) {
 780                 dgrp_t i;
 781
 782                 for (i=0; i < rfs->old_fs->group_desc_count; i++) {
 783                         if (IS_BLOCK_BM(fs, i, blk)) {
 784                                 ext2fs_block_bitmap_loc_set(fs, i, 0);
 785                                 rfs->needed_blocks++;
 786                                 return;
 787                         }
 788                         if (IS_INODE_BM(fs, i, blk)) {
 789                                 ext2fs_inode_bitmap_loc_set(fs, i, 0);
 790                                 rfs->needed_blocks++;
 791                                 return;
 792                         }
 793                         if (IS_INODE_TB(fs, i, blk)) {
 794                                 ext2fs_inode_table_loc_set(fs, i, 0);
 795                                 rfs->needed_blocks++;
 796                                 return;
 797                         }
 798                 }
 799         }
 800         if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 801                                        EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
 802                    (ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT))) {
 803                 /*
 804                  * If the block bitmap is uninitialized, which means
 805                  * nothing other than standard metadata in use.
 806                  */
 807                 return;
 808         } else if (ext2fs_test_block_bitmap2(rfs->old_fs->block_map, blk) &&
 809                    !ext2fs_test_block_bitmap2(meta_bmap, blk)) {
 810                 ext2fs_mark_block_bitmap2(rfs->move_blocks, blk);
 811                 rfs->needed_blocks++;
 812         }
 813 }
 814
 815
 816 /*
 817  * This routine marks and unmarks reserved blocks in the new block
 818  * bitmap.  It also determines which blocks need to be moved and
 819  * places this information into the move_blocks bitmap.
 820  */
 821 static errcode_t blocks_to_move(ext2_resize_t rfs)
 822 {
 823         int             j, has_super;
 824         dgrp_t          i, max_groups, g;
 825         blk64_t         blk, group_blk;
 826         blk64_t         old_blocks, new_blocks;
 827         unsigned int    meta_bg, meta_bg_size;
 828         errcode_t       retval;
 829         ext2_filsys     fs, old_fs;
 830         ext2fs_block_bitmap     meta_bmap;
 831         int             flex_bg;
 832
 833         fs = rfs->new_fs;
 834         old_fs = rfs->old_fs;
 835         if (ext2fs_blocks_count(old_fs->super) > ext2fs_blocks_count(fs->super))
 836                 fs = rfs->old_fs;
 837
 838         retval = ext2fs_allocate_block_bitmap(fs, _("blocks to be moved"),
 839                                               &rfs->move_blocks);
 840         if (retval)
 841                 return retval;
 842
 843         retval = ext2fs_allocate_block_bitmap(fs, _("meta-data blocks"),
 844                                               &meta_bmap);
 845         if (retval)
 846                 return retval;
 847
 848         retval = mark_table_blocks(old_fs, meta_bmap);
 849         if (retval)
 850                 return retval;
 851
 852         fs = rfs->new_fs;
 853
 854         /*
 855          * If we're shrinking the filesystem, we need to move all of
 856          * the blocks that don't fit any more
 857          */
 858         for (blk = ext2fs_blocks_count(fs->super);
 859              blk < ext2fs_blocks_count(old_fs->super); blk++) {
 860                 g = ext2fs_group_of_blk2(fs, blk);
 861                 if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 862                                                EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
 863                     ext2fs_bg_flags_test(old_fs, g, EXT2_BG_BLOCK_UNINIT)) {
 864                         /*
 865                          * The block bitmap is uninitialized, so skip
 866                          * to the next block group.
 867                          */
 868                         blk = ext2fs_group_first_block2(fs, g+1) - 1;
 869                         continue;
 870                 }
 871                 if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
 872                     !ext2fs_test_block_bitmap2(meta_bmap, blk)) {
 873                         ext2fs_mark_block_bitmap2(rfs->move_blocks, blk);
 874                         rfs->needed_blocks++;
 875                 }
 876                 ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
 877         }
 878
 879         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) {
 880                 old_blocks = old_fs->super->s_first_meta_bg;
 881                 new_blocks = fs->super->s_first_meta_bg;
 882         } else {
 883                 old_blocks = old_fs->desc_blocks + old_fs->super->s_reserved_gdt_blocks;
 884                 new_blocks = fs->desc_blocks + fs->super->s_reserved_gdt_blocks;
 885         }
 886
 887         if (old_blocks == new_blocks) {
 888                 retval = 0;
 889                 goto errout;
 890         }
 891
 892         max_groups = fs->group_desc_count;
 893         if (max_groups > old_fs->group_desc_count)
 894                 max_groups = old_fs->group_desc_count;
 895         group_blk = old_fs->super->s_first_data_block;
 896         /*
 897          * If we're reducing the number of descriptor blocks, this
 898          * makes life easy.  :-)   We just have to mark some extra
 899          * blocks as free.
 900          */
 901         if (old_blocks > new_blocks) {
 902                 for (i = 0; i < max_groups; i++) {
 903                         if (!ext2fs_bg_has_super(fs, i)) {
 904                                 group_blk += fs->super->s_blocks_per_group;
 905                                 continue;
 906                         }
 907                         for (blk = group_blk+1+new_blocks;
 908                              blk < group_blk+1+old_blocks; blk++) {
 909                                 ext2fs_block_alloc_stats2(fs, blk, -1);
 910                                 rfs->needed_blocks--;
 911                         }
 912                         group_blk += fs->super->s_blocks_per_group;
 913                 }
 914                 retval = 0;
 915                 goto errout;
 916         }
 917         /*
 918          * If we're increasing the number of descriptor blocks, life
 919          * gets interesting....
 920          */
 921         meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
 922         flex_bg = fs->super->s_feature_incompat &
 923                 EXT4_FEATURE_INCOMPAT_FLEX_BG;
 924         /* first reserve all of the existing fs meta blocks */
 925         for (i = 0; i < max_groups; i++) {
 926                 has_super = ext2fs_bg_has_super(fs, i);
 927                 if (has_super)
 928                         mark_fs_metablock(rfs, meta_bmap, i, group_blk);
 929
 930                 meta_bg = i / meta_bg_size;
 931                 if (!(fs->super->s_feature_incompat &
 932                       EXT2_FEATURE_INCOMPAT_META_BG) ||
 933                     (meta_bg < fs->super->s_first_meta_bg)) {
 934                         if (has_super) {
 935                                 for (blk = group_blk+1;
 936                                      blk < group_blk + 1 + new_blocks; blk++)
 937                                         mark_fs_metablock(rfs, meta_bmap,
 938                                                           i, blk);
 939                         }
 940                 } else {
 941                         if (has_super)
 942                                 has_super = 1;
 943                         if (((i % meta_bg_size) == 0) ||
 944                             ((i % meta_bg_size) == 1) ||
 945                             ((i % meta_bg_size) == (meta_bg_size-1)))
 946                                 mark_fs_metablock(rfs, meta_bmap, i,
 947                                                   group_blk + has_super);
 948                 }
 949
 950                 /*
 951                  * Reserve the existing meta blocks that we know
 952                  * aren't to be moved.
 953                  *
 954                  * For flex_bg file systems, in order to avoid
 955                  * overwriting fs metadata (especially inode table
 956                  * blocks) belonging to a different block group when
 957                  * we are relocating the inode tables, we need to
 958                  * reserve all existing fs metadata blocks.
 959                  */
 960                 if (ext2fs_block_bitmap_loc(fs, i))
 961                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
 962                                  ext2fs_block_bitmap_loc(fs, i));
 963                 else if (flex_bg && i < old_fs->group_desc_count)
 964                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
 965                                  ext2fs_block_bitmap_loc(old_fs, i));
 966
 967                 if (ext2fs_inode_bitmap_loc(fs, i))
 968                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
 969                                  ext2fs_inode_bitmap_loc(fs, i));
 970                 else if (flex_bg && i < old_fs->group_desc_count)
 971                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
 972                                  ext2fs_inode_bitmap_loc(old_fs, i));
 973
 974                 if (ext2fs_inode_table_loc(fs, i))
 975                         ext2fs_mark_block_bitmap_range2(rfs->reserve_blocks,
 976                                         ext2fs_inode_table_loc(fs, i),
 977                                         fs->inode_blocks_per_group);
 978                 else if (flex_bg && i < old_fs->group_desc_count)
 979                         ext2fs_mark_block_bitmap_range2(rfs->reserve_blocks,
 980                                         ext2fs_inode_table_loc(old_fs, i),
 981                                         old_fs->inode_blocks_per_group);
 982
 983                 group_blk += rfs->new_fs->super->s_blocks_per_group;
 984         }
 985
 986         /* Allocate the missing data structures */
 987         for (i = 0; i < max_groups; i++) {
 988                 if (ext2fs_inode_table_loc(fs, i) &&
 989                     ext2fs_inode_bitmap_loc(fs, i) &&
 990                     ext2fs_block_bitmap_loc(fs, i))
 991                         continue;
 992
 993                 retval = ext2fs_allocate_group_table(fs, i,
 994                                                      rfs->reserve_blocks);
 995                 if (retval)
 996                         goto errout;
 997
 998                 /*
 999                  * For those structures that have changed, we need to
1000                  * do bookkeepping.
1001                  */
1002                 if (ext2fs_block_bitmap_loc(old_fs, i) !=
1003                     (blk = ext2fs_block_bitmap_loc(fs, i))) {
1004                         ext2fs_block_alloc_stats2(fs, blk, +1);
1005                         if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
1006                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
1007                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
1008                                                          blk);
1009                 }
1010                 if (ext2fs_inode_bitmap_loc(old_fs, i) !=
1011                     (blk = ext2fs_inode_bitmap_loc(fs, i))) {
1012                         ext2fs_block_alloc_stats2(fs, blk, +1);
1013                         if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
1014                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
1015                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
1016                                                          blk);
1017                 }
1018
1019                 /*
1020                  * The inode table, if we need to relocate it, is
1021                  * handled specially.  We have to reserve the blocks
1022                  * for both the old and the new inode table, since we
1023                  * can't have the inode table be destroyed during the
1024                  * block relocation phase.
1025                  */
1026                 if (ext2fs_inode_table_loc(fs, i) == ext2fs_inode_table_loc(old_fs, i))
1027                         continue;       /* inode table not moved */
1028
1029                 rfs->needed_blocks += fs->inode_blocks_per_group;
1030
1031                 /*
1032                  * Mark the new inode table as in use in the new block
1033                  * allocation bitmap, and move any blocks that might
1034                  * be necessary.
1035                  */
1036                 for (blk = ext2fs_inode_table_loc(fs, i), j=0;
1037                      j < fs->inode_blocks_per_group ; j++, blk++) {
1038                         ext2fs_block_alloc_stats2(fs, blk, +1);
1039                         if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
1040                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
1041                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
1042                                                          blk);
1043                 }
1044
1045                 /*
1046                  * Make sure the old inode table is reserved in the
1047                  * block reservation bitmap.
1048                  */
1049                 for (blk = ext2fs_inode_table_loc(rfs->old_fs, i), j=0;
1050                      j < fs->inode_blocks_per_group ; j++, blk++)
1051                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
1052         }
1053         retval = 0;
1054
1055 errout:
1056         if (meta_bmap)
1057                 ext2fs_free_block_bitmap(meta_bmap);
1058
1059         return retval;
1060 }
1061
1062 /*
1063  * This helper function tries to allocate a new block.  We try to
1064  * avoid hitting the original group descriptor blocks at least at
1065  * first, since we want to make it possible to recover from a badly
1066  * aborted resize operation as much as possible.
1067  *
1068  * In the future, I may further modify this routine to balance out
1069  * where we get the new blocks across the various block groups.
1070  * Ideally we would allocate blocks that corresponded with the block
1071  * group of the containing inode, and keep contiguous blocks
1072  * together.  However, this very difficult to do efficiently, since we
1073  * don't have the necessary information up front.
1074  */
1075
1076 #define AVOID_OLD       1
1077 #define DESPERATION     2
1078
1079 static void init_block_alloc(ext2_resize_t rfs)
1080 {
1081         rfs->alloc_state = AVOID_OLD;
1082         rfs->new_blk = rfs->new_fs->super->s_first_data_block;
1083 #if 0
1084         /* HACK for testing */
1085         if (ext2fs_blocks_count(rfs->new_fs->super) >
1086             ext2fs_blocks_count(rfs->old_fs->super))
1087                 rfs->new_blk = ext2fs_blocks_count(rfs->old_fs->super);
1088 #endif
1089 }
1090
1091 static blk64_t get_new_block(ext2_resize_t rfs)
1092 {
1093         ext2_filsys     fs = rfs->new_fs;
1094
1095         while (1) {
1096                 if (rfs->new_blk >= ext2fs_blocks_count(fs->super)) {
1097                         if (rfs->alloc_state == DESPERATION)
1098                                 return 0;
1099
1100 #ifdef RESIZE2FS_DEBUG
1101                         if (rfs->flags & RESIZE_DEBUG_BMOVE)
1102                                 printf("Going into desperation mode "
1103                                        "for block allocations\n");
1104 #endif
1105                         rfs->alloc_state = DESPERATION;
1106                         rfs->new_blk = fs->super->s_first_data_block;
1107                         continue;
1108                 }
1109                 if (ext2fs_test_block_bitmap2(fs->block_map, rfs->new_blk) ||
1110                     ext2fs_test_block_bitmap2(rfs->reserve_blocks,
1111                                              rfs->new_blk) ||
1112                     ((rfs->alloc_state == AVOID_OLD) &&
1113                      (rfs->new_blk < ext2fs_blocks_count(rfs->old_fs->super)) &&
1114                      ext2fs_test_block_bitmap2(rfs->old_fs->block_map,
1115                                               rfs->new_blk))) {
1116                         rfs->new_blk++;
1117                         continue;
1118                 }
1119                 return rfs->new_blk;
1120         }
1121 }
1122
1123 static errcode_t resize2fs_get_alloc_block(ext2_filsys fs, blk64_t goal,
1124                                            blk64_t *ret)
1125 {
1126         ext2_resize_t rfs = (ext2_resize_t) fs->priv_data;
1127         blk64_t blk;
1128
1129         blk = get_new_block(rfs);
1130         if (!blk)
1131                 return ENOSPC;
1132
1133 #ifdef RESIZE2FS_DEBUG
1134         if (rfs->flags & 0xF)
1135                 printf("get_alloc_block allocating %llu\n", blk);
1136 #endif
1137
1138         ext2fs_mark_block_bitmap2(rfs->old_fs->block_map, blk);
1139         ext2fs_mark_block_bitmap2(rfs->new_fs->block_map, blk);
1140         *ret = (blk64_t) blk;
1141         return 0;
1142 }
1143
1144 static errcode_t block_mover(ext2_resize_t rfs)
1145 {
1146         blk64_t                 blk, old_blk, new_blk;
1147         ext2_filsys             fs = rfs->new_fs;
1148         ext2_filsys             old_fs = rfs->old_fs;
1149         errcode_t               retval;
1150         __u64                   size;
1151         int                     c;
1152         int                     to_move, moved;
1153         ext2_badblocks_list     badblock_list = 0;
1154         int                     bb_modified = 0;
1155
1156         fs->get_alloc_block = resize2fs_get_alloc_block;
1157         old_fs->get_alloc_block = resize2fs_get_alloc_block;
1158
1159         retval = ext2fs_read_bb_inode(old_fs, &badblock_list);
1160         if (retval)
1161                 return retval;
1162
1163         new_blk = fs->super->s_first_data_block;
1164         if (!rfs->itable_buf) {
1165                 retval = ext2fs_get_array(fs->blocksize,
1166                                         fs->inode_blocks_per_group,
1167                                         &rfs->itable_buf);
1168                 if (retval)
1169                         return retval;
1170         }
1171         retval = ext2fs_create_extent_table(&rfs->bmap, 0);
1172         if (retval)
1173                 return retval;
1174
1175         /*
1176          * The first step is to figure out where all of the blocks
1177          * will go.
1178          */
1179         to_move = moved = 0;
1180         init_block_alloc(rfs);
1181         for (blk = old_fs->super->s_first_data_block;
1182              blk < ext2fs_blocks_count(old_fs->super); blk++) {
1183                 if (!ext2fs_test_block_bitmap2(old_fs->block_map, blk))
1184                         continue;
1185                 if (!ext2fs_test_block_bitmap2(rfs->move_blocks, blk))
1186                         continue;
1187                 if (ext2fs_badblocks_list_test(badblock_list, blk)) {
1188                         ext2fs_badblocks_list_del(badblock_list, blk);
1189                         bb_modified++;
1190                         continue;
1191                 }
1192
1193                 new_blk = get_new_block(rfs);
1194                 if (!new_blk) {
1195                         retval = ENOSPC;
1196                         goto errout;
1197                 }
1198                 ext2fs_block_alloc_stats2(fs, new_blk, +1);
1199                 ext2fs_add_extent_entry(rfs->bmap, blk, new_blk);
1200                 to_move++;
1201         }
1202
1203         if (to_move == 0) {
1204                 if (rfs->bmap) {
1205                         ext2fs_free_extent_table(rfs->bmap);
1206                         rfs->bmap = 0;
1207                 }
1208                 retval = 0;
1209                 goto errout;
1210         }
1211
1212         /*
1213          * Step two is to actually move the blocks
1214          */
1215         retval =  ext2fs_iterate_extent(rfs->bmap, 0, 0, 0);
1216         if (retval) goto errout;
1217
1218         if (rfs->progress) {
1219                 retval = (rfs->progress)(rfs, E2_RSZ_BLOCK_RELOC_PASS,
1220                                          0, to_move);
1221                 if (retval)
1222                         goto errout;
1223         }
1224         while (1) {
1225                 retval = ext2fs_iterate_extent(rfs->bmap, &old_blk, &new_blk, &size);
1226                 if (retval) goto errout;
1227                 if (!size)
1228                         break;
1229 #ifdef RESIZE2FS_DEBUG
1230                 if (rfs->flags & RESIZE_DEBUG_BMOVE)
1231                         printf("Moving %llu blocks %llu->%llu\n",
1232                                size, old_blk, new_blk);
1233 #endif
1234                 do {
1235                         c = size;
1236                         if (c > fs->inode_blocks_per_group)
1237                                 c = fs->inode_blocks_per_group;
1238                         retval = io_channel_read_blk64(fs->io, old_blk, c,
1239                                                        rfs->itable_buf);
1240                         if (retval) goto errout;
1241                         retval = io_channel_write_blk64(fs->io, new_blk, c,
1242                                                         rfs->itable_buf);
1243                         if (retval) goto errout;
1244                         size -= c;
1245                         new_blk += c;
1246                         old_blk += c;
1247                         moved += c;
1248                         if (rfs->progress) {
1249                                 io_channel_flush(fs->io);
1250                                 retval = (rfs->progress)(rfs,
1251                                                 E2_RSZ_BLOCK_RELOC_PASS,
1252                                                 moved, to_move);
1253                                 if (retval)
1254                                         goto errout;
1255                         }
1256                 } while (size > 0);
1257                 io_channel_flush(fs->io);
1258         }
1259
1260 errout:
1261         if (badblock_list) {
1262                 if (!retval && bb_modified)
1263                         retval = ext2fs_update_bb_inode(old_fs,
1264                                                         badblock_list);
1265                 ext2fs_badblocks_list_free(badblock_list);
1266         }
1267         return retval;
1268 }
1269
1270
1271 /* --------------------------------------------------------------------
1272  *
1273  * Resize processing, phase 3
1274  *
1275  * --------------------------------------------------------------------
1276  */
1277
1278
1279 struct process_block_struct {
1280         ext2_resize_t           rfs;
1281         ext2_ino_t              ino;
1282         struct ext2_inode *     inode;
1283         errcode_t               error;
1284         int                     is_dir;
1285         int                     changed;
1286 };
1287
1288 static int process_block(ext2_filsys fs, blk64_t        *block_nr,
1289                          e2_blkcnt_t blockcnt,
1290                          blk64_t ref_block EXT2FS_ATTR((unused)),
1291                          int ref_offset EXT2FS_ATTR((unused)), void *priv_data)
1292 {
1293         struct process_block_struct *pb;
1294         errcode_t       retval;
1295         blk64_t         block, new_block;
1296         int             ret = 0;
1297
1298         pb = (struct process_block_struct *) priv_data;
1299         block = *block_nr;
1300         if (pb->rfs->bmap) {
1301                 new_block = ext2fs_extent_translate(pb->rfs->bmap, block);
1302                 if (new_block) {
1303                         *block_nr = new_block;
1304                         ret |= BLOCK_CHANGED;
1305                         pb->changed = 1;
1306 #ifdef RESIZE2FS_DEBUG
1307                         if (pb->rfs->flags & RESIZE_DEBUG_BMOVE)
1308                                 printf("ino=%u, blockcnt=%lld, %llu->%llu\n",
1309                                        pb->ino, blockcnt, block, new_block);
1310 #endif
1311                         block = new_block;
1312                 }
1313         }
1314         if (pb->is_dir) {
1315                 retval = ext2fs_add_dir_block2(fs->dblist, pb->ino,
1316                                                block, (int) blockcnt);
1317                 if (retval) {
1318                         pb->error = retval;
1319                         ret |= BLOCK_ABORT;
1320                 }
1321         }
1322         return ret;
1323 }
1324
1325 /*
1326  * Progress callback
1327  */
1328 static errcode_t progress_callback(ext2_filsys fs,
1329                                    ext2_inode_scan scan EXT2FS_ATTR((unused)),
1330                                    dgrp_t group, void * priv_data)
1331 {
1332         ext2_resize_t rfs = (ext2_resize_t) priv_data;
1333         errcode_t               retval;
1334
1335         /*
1336          * This check is to protect against old ext2 libraries.  It
1337          * shouldn't be needed against new libraries.
1338          */
1339         if ((group+1) == 0)
1340                 return 0;
1341
1342         if (rfs->progress) {
1343                 io_channel_flush(fs->io);
1344                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
1345                                          group+1, fs->group_desc_count);
1346                 if (retval)
1347                         return retval;
1348         }
1349
1350         return 0;
1351 }
1352
1353 static errcode_t inode_scan_and_fix(ext2_resize_t rfs)
1354 {
1355         struct process_block_struct     pb;
1356         ext2_ino_t              ino, new_inode;
1357         struct ext2_inode       *inode = NULL;
1358         ext2_inode_scan         scan = NULL;
1359         errcode_t               retval;
1360         char                    *block_buf = 0;
1361         ext2_ino_t              start_to_move;
1362         blk64_t                 orig_size;
1363         blk64_t                 new_block;
1364         int                     inode_size;
1365
1366         if ((rfs->old_fs->group_desc_count <=
1367              rfs->new_fs->group_desc_count) &&
1368             !rfs->bmap)
1369                 return 0;
1370
1371         /*
1372          * Save the original size of the old filesystem, and
1373          * temporarily set the size to be the new size if the new size
1374          * is larger.  We need to do this to avoid catching an error
1375          * by the block iterator routines
1376          */
1377         orig_size = ext2fs_blocks_count(rfs->old_fs->super);
1378         if (orig_size < ext2fs_blocks_count(rfs->new_fs->super))
1379                 ext2fs_blocks_count_set(rfs->old_fs->super,
1380                                 ext2fs_blocks_count(rfs->new_fs->super));
1381
1382         retval = ext2fs_open_inode_scan(rfs->old_fs, 0, &scan);
1383         if (retval) goto errout;
1384
1385         retval = ext2fs_init_dblist(rfs->old_fs, 0);
1386         if (retval) goto errout;
1387         retval = ext2fs_get_array(rfs->old_fs->blocksize, 3, &block_buf);
1388         if (retval) goto errout;
1389
1390         start_to_move = (rfs->new_fs->group_desc_count *
1391                          rfs->new_fs->super->s_inodes_per_group);
1392
1393         if (rfs->progress) {
1394                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
1395                                          0, rfs->old_fs->group_desc_count);
1396                 if (retval)
1397                         goto errout;
1398         }
1399         ext2fs_set_inode_callback(scan, progress_callback, (void *) rfs);
1400         pb.rfs = rfs;
1401         pb.inode = inode;
1402         pb.error = 0;
1403         new_inode = EXT2_FIRST_INODE(rfs->new_fs->super);
1404         inode_size = EXT2_INODE_SIZE(rfs->new_fs->super);
1405         inode = malloc(inode_size);
1406         if (!inode) {
1407                 retval = ENOMEM;
1408                 goto errout;
1409         }
1410         /*
1411          * First, copy all of the inodes that need to be moved
1412          * elsewhere in the inode table
1413          */
1414         while (1) {
1415                 retval = ext2fs_get_next_inode_full(scan, &ino, inode, inode_size);
1416                 if (retval) goto errout;
1417                 if (!ino)
1418                         break;
1419
1420                 if (inode->i_links_count == 0 && ino != EXT2_RESIZE_INO)
1421                         continue; /* inode not in use */
1422
1423                 pb.is_dir = LINUX_S_ISDIR(inode->i_mode);
1424                 pb.changed = 0;
1425
1426                 if (ext2fs_file_acl_block(rfs->old_fs, inode) && rfs->bmap) {
1427                         new_block = ext2fs_extent_translate(rfs->bmap,
1428                                 ext2fs_file_acl_block(rfs->old_fs, inode));
1429                         if (new_block) {
1430                                 ext2fs_file_acl_block_set(rfs->old_fs, inode,
1431                                                           new_block);
1432                                 retval = ext2fs_write_inode_full(rfs->old_fs,
1433                                                             ino, inode, inode_size);
1434                                 if (retval) goto errout;
1435                         }
1436                 }
1437
1438                 if (ext2fs_inode_has_valid_blocks2(rfs->old_fs, inode) &&
1439                     (rfs->bmap || pb.is_dir)) {
1440                         pb.ino = ino;
1441                         retval = ext2fs_block_iterate3(rfs->old_fs,
1442                                                        ino, 0, block_buf,
1443                                                        process_block, &pb);
1444                         if (retval)
1445                                 goto errout;
1446                         if (pb.error) {
1447                                 retval = pb.error;
1448                                 goto errout;
1449                         }
1450                 }
1451
1452                 if (ino <= start_to_move)
1453                         continue; /* Don't need to move it. */
1454
1455                 /*
1456                  * Find a new inode
1457                  */
1458                 retval = ext2fs_new_inode(rfs->new_fs, 0, 0, 0, &new_inode);
1459                 if (retval)
1460                         goto errout;
1461
1462                 ext2fs_inode_alloc_stats2(rfs->new_fs, new_inode, +1,
1463                                           pb.is_dir);
1464                 if (pb.changed) {
1465                         /* Get the new version of the inode */
1466                         retval = ext2fs_read_inode_full(rfs->old_fs, ino,
1467                                                 inode, inode_size);
1468                         if (retval) goto errout;
1469                 }
1470                 inode->i_ctime = time(0);
1471                 retval = ext2fs_write_inode_full(rfs->old_fs, new_inode,
1472                                                 inode, inode_size);
1473                 if (retval) goto errout;
1474
1475 #ifdef RESIZE2FS_DEBUG
1476                 if (rfs->flags & RESIZE_DEBUG_INODEMAP)
1477                         printf("Inode moved %u->%u\n", ino, new_inode);
1478 #endif
1479                 if (!rfs->imap) {
1480                         retval = ext2fs_create_extent_table(&rfs->imap, 0);
1481                         if (retval)
1482                                 goto errout;
1483                 }
1484                 ext2fs_add_extent_entry(rfs->imap, ino, new_inode);
1485         }
1486         io_channel_flush(rfs->old_fs->io);
1487
1488 errout:
1489         ext2fs_blocks_count_set(rfs->old_fs->super, orig_size);
1490         if (rfs->bmap) {
1491                 ext2fs_free_extent_table(rfs->bmap);
1492                 rfs->bmap = 0;
1493         }
1494         if (scan)
1495                 ext2fs_close_inode_scan(scan);
1496         if (block_buf)
1497                 ext2fs_free_mem(&block_buf);
1498         free(inode);
1499         return retval;
1500 }
1501
1502 /* --------------------------------------------------------------------
1503  *
1504  * Resize processing, phase 4.
1505  *
1506  * --------------------------------------------------------------------
1507  */
1508
1509 struct istruct {
1510         ext2_resize_t rfs;
1511         errcode_t       err;
1512         unsigned int    max_dirs;
1513         unsigned int    num;
1514 };
1515
1516 static int check_and_change_inodes(ext2_ino_t dir,
1517                                    int entry EXT2FS_ATTR((unused)),
1518                                    struct ext2_dir_entry *dirent, int offset,
1519                                    int  blocksize EXT2FS_ATTR((unused)),
1520                                    char *buf EXT2FS_ATTR((unused)),
1521                                    void *priv_data)
1522 {
1523         struct istruct *is = (struct istruct *) priv_data;
1524         struct ext2_inode       inode;
1525         ext2_ino_t              new_inode;
1526         errcode_t               retval;
1527
1528         if (is->rfs->progress && offset == 0) {
1529                 io_channel_flush(is->rfs->old_fs->io);
1530                 is->err = (is->rfs->progress)(is->rfs,
1531                                               E2_RSZ_INODE_REF_UPD_PASS,
1532                                               ++is->num, is->max_dirs);
1533                 if (is->err)
1534                         return DIRENT_ABORT;
1535         }
1536
1537         if (!dirent->inode)
1538                 return 0;
1539
1540         new_inode = ext2fs_extent_translate(is->rfs->imap, dirent->inode);
1541
1542         if (!new_inode)
1543                 return 0;
1544 #ifdef RESIZE2FS_DEBUG
1545         if (is->rfs->flags & RESIZE_DEBUG_INODEMAP)
1546                 printf("Inode translate (dir=%u, name=%.*s, %u->%u)\n",
1547                        dir, dirent->name_len&0xFF, dirent->name,
1548                        dirent->inode, new_inode);
1549 #endif
1550
1551         dirent->inode = new_inode;
1552
1553         /* Update the directory mtime and ctime */
1554         retval = ext2fs_read_inode(is->rfs->old_fs, dir, &inode);
1555         if (retval == 0) {
1556                 inode.i_mtime = inode.i_ctime = time(0);
1557                 is->err = ext2fs_write_inode(is->rfs->old_fs, dir, &inode);
1558                 if (is->err)
1559                         return DIRENT_ABORT;
1560         }
1561
1562         return DIRENT_CHANGED;
1563 }
1564
1565 static errcode_t inode_ref_fix(ext2_resize_t rfs)
1566 {
1567         errcode_t               retval;
1568         struct istruct          is;
1569
1570         if (!rfs->imap)
1571                 return 0;
1572
1573         /*
1574          * Now, we iterate over all of the directories to update the
1575          * inode references
1576          */
1577         is.num = 0;
1578         is.max_dirs = ext2fs_dblist_count2(rfs->old_fs->dblist);
1579         is.rfs = rfs;
1580         is.err = 0;
1581
1582         if (rfs->progress) {
1583                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS,
1584                                          0, is.max_dirs);
1585                 if (retval)
1586                         goto errout;
1587         }
1588
1589         retval = ext2fs_dblist_dir_iterate(rfs->old_fs->dblist,
1590                                            DIRENT_FLAG_INCLUDE_EMPTY, 0,
1591                                            check_and_change_inodes, &is);
1592         if (retval)
1593                 goto errout;
1594         if (is.err) {
1595                 retval = is.err;
1596                 goto errout;
1597         }
1598
1599         if (rfs->progress && (is.num < is.max_dirs))
1600                 (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS,
1601                                 is.max_dirs, is.max_dirs);
1602
1603 errout:
1604         ext2fs_free_extent_table(rfs->imap);
1605         rfs->imap = 0;
1606         return retval;
1607 }
1608
1609
1610 /* --------------------------------------------------------------------
1611  *
1612  * Resize processing, phase 5.
1613  *
1614  * In this phase we actually move the inode table around, and then
1615  * update the summary statistics.  This is scary, since aborting here
1616  * will potentially scramble the filesystem.  (We are moving the
1617  * inode tables around in place, and so the potential for lost data,
1618  * or at the very least scrambling the mapping between filenames and
1619  * inode numbers is very high in case of a power failure here.)
1620  * --------------------------------------------------------------------
1621  */
1622
1623
1624 /*
1625  * A very scary routine --- this one moves the inode table around!!!
1626  *
1627  * After this you have to use the rfs->new_fs file handle to read and
1628  * write inodes.
1629  */
1630 static errcode_t move_itables(ext2_resize_t rfs)
1631 {
1632         int             n, num, size;
1633         long long       diff;
1634         dgrp_t          i, max_groups;
1635         ext2_filsys     fs = rfs->new_fs;
1636         char            *cp;
1637         blk64_t         old_blk, new_blk, blk;
1638         errcode_t       retval;
1639         int             j, to_move, moved;
1640
1641         max_groups = fs->group_desc_count;
1642         if (max_groups > rfs->old_fs->group_desc_count)
1643                 max_groups = rfs->old_fs->group_desc_count;
1644
1645         size = fs->blocksize * fs->inode_blocks_per_group;
1646         if (!rfs->itable_buf) {
1647                 retval = ext2fs_get_mem(size, &rfs->itable_buf);
1648                 if (retval)
1649                         return retval;
1650         }
1651
1652         /*
1653          * Figure out how many inode tables we need to move
1654          */
1655         to_move = moved = 0;
1656         for (i=0; i < max_groups; i++)
1657                 if (ext2fs_inode_table_loc(rfs->old_fs, i) !=
1658                     ext2fs_inode_table_loc(fs, i))
1659                         to_move++;
1660
1661         if (to_move == 0)
1662                 return 0;
1663
1664         if (rfs->progress) {
1665                 retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
1666                                        0, to_move);
1667                 if (retval)
1668                         goto errout;
1669         }
1670
1671         rfs->old_fs->flags |= EXT2_FLAG_MASTER_SB_ONLY;
1672
1673         for (i=0; i < max_groups; i++) {
1674                 old_blk = ext2fs_inode_table_loc(rfs->old_fs, i);
1675                 new_blk = ext2fs_inode_table_loc(fs, i);
1676                 diff = new_blk - old_blk;
1677
1678 #ifdef RESIZE2FS_DEBUG
1679                 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1680                         printf("Itable move group %d block %llu->%llu (diff %lld)\n",
1681                                i, old_blk, new_blk, diff);
1682 #endif
1683
1684                 if (!diff)
1685                         continue;
1686
1687                 retval = io_channel_read_blk64(fs->io, old_blk,
1688                                                fs->inode_blocks_per_group,
1689                                                rfs->itable_buf);
1690                 if (retval)
1691                         goto errout;
1692                 /*
1693                  * The end of the inode table segment often contains
1694                  * all zeros, and we're often only moving the inode
1695                  * table down a block or two.  If so, we can optimize
1696                  * things by not rewriting blocks that we know to be zero
1697                  * already.
1698                  */
1699                 for (cp = rfs->itable_buf+size-1, n=0; n < size; n++, cp--)
1700                         if (*cp)
1701                                 break;
1702                 n = n >> EXT2_BLOCK_SIZE_BITS(fs->super);
1703 #ifdef RESIZE2FS_DEBUG
1704                 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1705                         printf("%d blocks of zeros...\n", n);
1706 #endif
1707                 num = fs->inode_blocks_per_group;
1708                 if (n > diff)
1709                         num -= n;
1710
1711                 retval = io_channel_write_blk64(fs->io, new_blk,
1712                                                 num, rfs->itable_buf);
1713                 if (retval) {
1714                         io_channel_write_blk64(fs->io, old_blk,
1715                                                num, rfs->itable_buf);
1716                         goto errout;
1717                 }
1718                 if (n > diff) {
1719                         retval = io_channel_write_blk64(fs->io,
1720                               old_blk + fs->inode_blocks_per_group,
1721                               diff, (rfs->itable_buf +
1722                                      (fs->inode_blocks_per_group - diff) *
1723                                      fs->blocksize));
1724                         if (retval)
1725                                 goto errout;
1726                 }
1727
1728                 for (blk = ext2fs_inode_table_loc(rfs->old_fs, i), j=0;
1729                      j < fs->inode_blocks_per_group ; j++, blk++)
1730                         ext2fs_block_alloc_stats2(fs, blk, -1);
1731
1732                 ext2fs_inode_table_loc_set(rfs->old_fs, i, new_blk);
1733                 ext2fs_group_desc_csum_set(rfs->old_fs, i);
1734                 ext2fs_mark_super_dirty(rfs->old_fs);
1735                 ext2fs_flush(rfs->old_fs);
1736
1737                 if (rfs->progress) {
1738                         retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
1739                                                ++moved, to_move);
1740                         if (retval)
1741                                 goto errout;
1742                 }
1743         }
1744         mark_table_blocks(fs, fs->block_map);
1745         ext2fs_flush(fs);
1746 #ifdef RESIZE2FS_DEBUG
1747         if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1748                 printf("Inode table move finished.\n");
1749 #endif
1750         return 0;
1751
1752 errout:
1753         return retval;
1754 }
1755
1756 /*
1757  * Fix the resize inode
1758  */
1759 static errcode_t fix_resize_inode(ext2_filsys fs)
1760 {
1761         struct ext2_inode       inode;
1762         errcode_t               retval;
1763         char                    *block_buf = NULL;
1764
1765         if (!(fs->super->s_feature_compat &
1766               EXT2_FEATURE_COMPAT_RESIZE_INODE))
1767                 return 0;
1768
1769         retval = ext2fs_get_mem(fs->blocksize, &block_buf);
1770         if (retval) goto errout;
1771
1772         retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode);
1773         if (retval) goto errout;
1774
1775         ext2fs_iblk_set(fs, &inode, 1);
1776
1777         retval = ext2fs_write_inode(fs, EXT2_RESIZE_INO, &inode);
1778         if (retval) goto errout;
1779
1780         if (!inode.i_block[EXT2_DIND_BLOCK]) {
1781                 /*
1782                  * Avoid zeroing out block #0; that's rude.  This
1783                  * should never happen anyway since the filesystem
1784                  * should be fsck'ed and we assume it is consistent.
1785                  */
1786                 fprintf(stderr,
1787                         _("Should never happen: resize inode corrupt!\n"));
1788                 exit(1);
1789         }
1790
1791         memset(block_buf, 0, fs->blocksize);
1792
1793         retval = io_channel_write_blk64(fs->io, inode.i_block[EXT2_DIND_BLOCK],
1794                                         1, block_buf);
1795         if (retval) goto errout;
1796
1797         retval = ext2fs_create_resize_inode(fs);
1798         if (retval)
1799                 goto errout;
1800
1801 errout:
1802         if (block_buf)
1803                 ext2fs_free_mem(&block_buf);
1804         return retval;
1805 }
1806
1807 /*
1808  * Finally, recalculate the summary information
1809  */
1810 static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs)
1811 {
1812         blk64_t         blk;
1813         ext2_ino_t      ino;
1814         unsigned int    group = 0;
1815         unsigned int    count = 0;
1816         blk64_t         total_blocks_free = 0;
1817         int             total_inodes_free = 0;
1818         int             group_free = 0;
1819         int             uninit = 0;
1820         blk64_t         super_blk, old_desc_blk, new_desc_blk;
1821         int             old_desc_blocks;
1822
1823         /*
1824          * First calculate the block statistics
1825          */
1826         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT);
1827         ext2fs_super_and_bgd_loc2(fs, group, &super_blk, &old_desc_blk,
1828                                   &new_desc_blk, 0);
1829         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
1830                 old_desc_blocks = fs->super->s_first_meta_bg;
1831         else
1832                 old_desc_blocks = fs->desc_blocks +
1833                         fs->super->s_reserved_gdt_blocks;
1834         for (blk = B2C(fs->super->s_first_data_block);
1835              blk < ext2fs_blocks_count(fs->super);
1836              blk += EXT2FS_CLUSTER_RATIO(fs)) {
1837                 if ((uninit &&
1838                      !(EQ_CLSTR(blk, super_blk) ||
1839                        ((old_desc_blk && old_desc_blocks &&
1840                          GE_CLSTR(blk, old_desc_blk) &&
1841                          LT_CLSTR(blk, old_desc_blk + old_desc_blocks))) ||
1842                        ((new_desc_blk && EQ_CLSTR(blk, new_desc_blk))) ||
1843                        EQ_CLSTR(blk, ext2fs_block_bitmap_loc(fs, group)) ||
1844                        EQ_CLSTR(blk, ext2fs_inode_bitmap_loc(fs, group)) ||
1845                        ((GE_CLSTR(blk, ext2fs_inode_table_loc(fs, group)) &&
1846                          LT_CLSTR(blk, ext2fs_inode_table_loc(fs, group)
1847                                   + fs->inode_blocks_per_group))))) ||
1848                     (!ext2fs_fast_test_block_bitmap2(fs->block_map, blk))) {
1849                         group_free++;
1850                         total_blocks_free++;
1851                 }
1852                 count++;
1853                 if ((count == fs->super->s_clusters_per_group) ||
1854                     EQ_CLSTR(blk, ext2fs_blocks_count(fs->super)-1)) {
1855                         ext2fs_bg_free_blocks_count_set(fs, group, group_free);
1856                         ext2fs_group_desc_csum_set(fs, group);
1857                         group++;
1858                         if (group >= fs->group_desc_count)
1859                                 break;
1860                         count = 0;
1861                         group_free = 0;
1862                         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT);
1863                         ext2fs_super_and_bgd_loc2(fs, group, &super_blk,
1864                                                   &old_desc_blk,
1865                                                   &new_desc_blk, 0);
1866                         if (fs->super->s_feature_incompat &
1867                             EXT2_FEATURE_INCOMPAT_META_BG)
1868                                 old_desc_blocks = fs->super->s_first_meta_bg;
1869                         else
1870                                 old_desc_blocks = fs->desc_blocks +
1871                                         fs->super->s_reserved_gdt_blocks;
1872                 }
1873         }
1874         total_blocks_free = C2B(total_blocks_free);
1875         ext2fs_free_blocks_count_set(fs->super, total_blocks_free);
1876
1877         /*
1878          * Next, calculate the inode statistics
1879          */
1880         group_free = 0;
1881         count = 0;
1882         group = 0;
1883
1884         /* Protect loop from wrap-around if s_inodes_count maxed */
1885         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT);
1886         for (ino = 1; ino <= fs->super->s_inodes_count && ino > 0; ino++) {
1887                 if (uninit ||
1888                     !ext2fs_fast_test_inode_bitmap2(fs->inode_map, ino)) {
1889                         group_free++;
1890                         total_inodes_free++;
1891                 }
1892                 count++;
1893                 if ((count == fs->super->s_inodes_per_group) ||
1894                     (ino == fs->super->s_inodes_count)) {
1895                         ext2fs_bg_free_inodes_count_set(fs, group, group_free);
1896                         ext2fs_group_desc_csum_set(fs, group);
1897                         group++;
1898                         if (group >= fs->group_desc_count)
1899                                 break;
1900                         count = 0;
1901                         group_free = 0;
1902                         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT);
1903                 }
1904         }
1905         fs->super->s_free_inodes_count = total_inodes_free;
1906         ext2fs_mark_super_dirty(fs);
1907         return 0;
1908 }
1909
1910 /*
1911  *  Journal may have been relocated; update the backup journal blocks
1912  *  in the superblock.
1913  */
1914 static errcode_t fix_sb_journal_backup(ext2_filsys fs)
1915 {
1916         errcode_t         retval;
1917         struct ext2_inode inode;
1918
1919         if (!(fs->super->s_feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1920                 return 0;
1921
1922         /* External journal? Nothing to do. */
1923         if (fs->super->s_journal_dev && !fs->super->s_journal_inum)
1924                 return 0;
1925
1926         retval = ext2fs_read_inode(fs, fs->super->s_journal_inum, &inode);
1927         if (retval)
1928                 return retval;
1929         memcpy(fs->super->s_jnl_blocks, inode.i_block, EXT2_N_BLOCKS*4);
1930         fs->super->s_jnl_blocks[15] = inode.i_size_high;
1931         fs->super->s_jnl_blocks[16] = inode.i_size;
1932         fs->super->s_jnl_backup_type = EXT3_JNL_BACKUP_BLOCKS;
1933         ext2fs_mark_super_dirty(fs);
1934         return 0;
1935 }
1936
1937 static int calc_group_overhead(ext2_filsys fs, blk64_t grp,
1938                                int old_desc_blocks)
1939 {
1940         blk64_t super_blk, old_desc_blk, new_desc_blk;
1941         int overhead;
1942
1943         /* inode table blocks plus allocation bitmaps */
1944         overhead = fs->inode_blocks_per_group + 2;
1945
1946         ext2fs_super_and_bgd_loc2(fs, grp, &super_blk,
1947                                   &old_desc_blk, &new_desc_blk, 0);
1948         if ((grp == 0) || super_blk)
1949                 overhead++;
1950         if (old_desc_blk)
1951                 overhead += old_desc_blocks;
1952         else if (new_desc_blk)
1953                 overhead++;
1954         return overhead;
1955 }
1956
1957
1958 /*
1959  * calcluate the minimum number of blocks the given fs can be resized to
1960  */
1961 blk64_t calculate_minimum_resize_size(ext2_filsys fs)
1962 {
1963         ext2_ino_t inode_count;
1964         blk64_t blks_needed, groups, data_blocks;
1965         blk64_t grp, data_needed, last_start;
1966         blk64_t overhead = 0;
1967         int old_desc_blocks;
1968         int extra_groups = 0;
1969         int flexbg_size = 1 << fs->super->s_log_groups_per_flex;
1970
1971         /*
1972          * first figure out how many group descriptors we need to
1973          * handle the number of inodes we have
1974          */
1975         inode_count = fs->super->s_inodes_count -
1976                 fs->super->s_free_inodes_count;
1977         blks_needed = ext2fs_div_ceil(inode_count,
1978                                       fs->super->s_inodes_per_group) *
1979                 EXT2_BLOCKS_PER_GROUP(fs->super);
1980         groups = ext2fs_div64_ceil(blks_needed,
1981                                    EXT2_BLOCKS_PER_GROUP(fs->super));
1982
1983         /*
1984          * number of old-style block group descriptor blocks
1985          */
1986         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
1987                 old_desc_blocks = fs->super->s_first_meta_bg;
1988         else
1989                 old_desc_blocks = fs->desc_blocks +
1990                         fs->super->s_reserved_gdt_blocks;
1991
1992         /* calculate how many blocks are needed for data */
1993         data_needed = ext2fs_blocks_count(fs->super) -
1994                 ext2fs_free_blocks_count(fs->super);
1995
1996         for (grp = 0; grp < fs->group_desc_count; grp++)
1997                 data_needed -= calc_group_overhead(fs, grp, old_desc_blocks);
1998
1999         /*
2000          * For ext4 we need to allow for up to a flex_bg worth of
2001          * inode tables of slack space so the resize operation can be
2002          * guaranteed to finish.
2003          */
2004         if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_FLEX_BG) {
2005                 extra_groups = flexbg_size - (groups & (flexbg_size - 1));
2006                 data_needed += fs->inode_blocks_per_group * extra_groups;
2007                 extra_groups = groups % flexbg_size;
2008         }
2009
2010         /*
2011          * figure out how many data blocks we have given the number of groups
2012          * we need for our inodes
2013          */
2014         data_blocks = groups * EXT2_BLOCKS_PER_GROUP(fs->super);
2015         last_start = 0;
2016         for (grp = 0; grp < groups; grp++) {
2017                 overhead = calc_group_overhead(fs, grp, old_desc_blocks);
2018
2019                 /*
2020                  * we want to keep track of how much data we can store in
2021                  * the groups leading up to the last group so we can determine
2022                  * how big the last group needs to be
2023                  */
2024                 if (grp != (groups - 1))
2025                         last_start += EXT2_BLOCKS_PER_GROUP(fs->super) -
2026                                 overhead;
2027
2028                 data_blocks -= overhead;
2029         }
2030
2031         /*
2032          * if we need more group descriptors in order to accomodate our data
2033          * then we need to add them here
2034          */
2035         while (data_needed > data_blocks) {
2036                 blk64_t remainder = data_needed - data_blocks;
2037                 blk64_t extra_grps;
2038
2039                 /* figure out how many more groups we need for the data */
2040                 extra_grps = ext2fs_div64_ceil(remainder,
2041                                                EXT2_BLOCKS_PER_GROUP(fs->super));
2042
2043                 data_blocks += extra_grps * EXT2_BLOCKS_PER_GROUP(fs->super);
2044
2045                 /* ok we have to account for the last group */
2046                 overhead = calc_group_overhead(fs, groups-1, old_desc_blocks);
2047                 last_start += EXT2_BLOCKS_PER_GROUP(fs->super) - overhead;
2048
2049                 for (grp = groups; grp < groups+extra_grps; grp++) {
2050                         overhead = calc_group_overhead(fs, grp,
2051                                                        old_desc_blocks);
2052
2053                         /*
2054                          * again, we need to see how much data we cram into
2055                          * all of the groups leading up to the last group
2056                          */
2057                         if (grp != (groups + extra_grps - 1))
2058                                 last_start += EXT2_BLOCKS_PER_GROUP(fs->super)
2059                                         - overhead;
2060
2061                         data_blocks -= overhead;
2062                 }
2063
2064                 groups += extra_grps;
2065                 extra_groups += extra_grps;
2066                 if (fs->super->s_feature_incompat
2067                         & EXT4_FEATURE_INCOMPAT_FLEX_BG
2068                     && extra_groups > flexbg_size) {
2069                         /*
2070                          * For ext4 we need to allow for up to a flex_bg worth
2071                          * of inode tables of slack space so the resize
2072                          * operation can be guaranteed to finish.
2073                          */
2074                         extra_groups = flexbg_size -
2075                                                 (groups & (flexbg_size - 1));
2076                         data_needed += (fs->inode_blocks_per_group *
2077                                         extra_groups);
2078                         extra_groups = groups % flexbg_size;
2079                 }
2080         }
2081
2082         /* now for the fun voodoo */
2083         overhead = calc_group_overhead(fs, groups-1, old_desc_blocks);
2084
2085         /*
2086          * if this is the case then the last group is going to have data in it
2087          * so we need to adjust the size of the last group accordingly
2088          */
2089         if (last_start < data_needed) {
2090                 blk64_t remainder = data_needed - last_start;
2091
2092                 /*
2093                  * 50 is a magic number that mkfs/resize uses to see if its
2094                  * even worth making/resizing the fs.  basically you need to
2095                  * have at least 50 blocks in addition to the blocks needed
2096                  * for the metadata in the last group
2097                  */
2098                 if (remainder > 50)
2099                         overhead += remainder;
2100                 else
2101                         overhead += 50;
2102         } else
2103                 overhead += 50;
2104
2105         overhead += fs->super->s_first_data_block;
2106
2107         /*
2108          * since our last group doesn't have to be BLOCKS_PER_GROUP large, we
2109          * only do groups-1, and then add the number of blocks needed to
2110          * handle the group descriptor metadata+data that we need
2111          */
2112         blks_needed = (groups-1) * EXT2_BLOCKS_PER_GROUP(fs->super);
2113         blks_needed += overhead;
2114
2115         /*
2116          * If at this point we've already added up more "needed" than
2117          * the current size, just return current size as minimum.
2118          */
2119         if (blks_needed >= ext2fs_blocks_count(fs->super))
2120                 return ext2fs_blocks_count(fs->super);
2121         /*
2122          * We need to reserve a few extra blocks if extents are
2123          * enabled, in case we need to grow the extent tree.  The more
2124          * we shrink the file system, the more space we need.
2125          */
2126         if (fs->super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_EXTENTS)
2127                 blks_needed += (ext2fs_blocks_count(fs->super) -
2128                                 blks_needed)/500;
2129
2130         return blks_needed;
2131 }