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 Theodore 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 resize2fs_calculate_summary_stats(ext2_filsys fs);
  53 static errcode_t fix_sb_journal_backup(ext2_filsys fs);
  54 static errcode_t mark_table_blocks(ext2_filsys fs,
  55                                    ext2fs_block_bitmap bmap);
  56 static errcode_t clear_sparse_super2_last_group(ext2_resize_t rfs);
  57 static errcode_t reserve_sparse_super2_last_group(ext2_resize_t rfs,
  58                                                  ext2fs_block_bitmap meta_bmap);
  59 static errcode_t resize_group_descriptors(ext2_resize_t rfs, blk64_t new_size);
  60 static errcode_t move_bg_metadata(ext2_resize_t rfs);
  61 static errcode_t zero_high_bits_in_inodes(ext2_resize_t rfs);
  62
  63 /*
  64  * Some helper functions to check if a block is in a metadata area
  65  */
  66 static inline int is_block_bm(ext2_filsys fs, unsigned int grp, blk64_t blk)
  67 {
  68         return blk == ext2fs_block_bitmap_loc(fs, grp);
  69 }
  70
  71 static inline int is_inode_bm(ext2_filsys fs, unsigned int grp, blk64_t blk)
  72 {
  73         return blk == ext2fs_inode_bitmap_loc(fs, grp);
  74 }
  75
  76 static int is_inode_tb(ext2_filsys fs, unsigned int grp, blk64_t blk)
  77 {
  78         return blk >= ext2fs_inode_table_loc(fs, grp) &&
  79                blk < (ext2fs_inode_table_loc(fs, grp) +
  80                       fs->inode_blocks_per_group);
  81 }
  82
  83 /* Some bigalloc helper macros which are more succinct... */
  84 #define B2C(x)  EXT2FS_B2C(fs, (x))
  85 #define C2B(x)  EXT2FS_C2B(fs, (x))
  86 #define EQ_CLSTR(x, y) (B2C(x) == B2C(y))
  87 #define LE_CLSTR(x, y) (B2C(x) <= B2C(y))
  88 #define LT_CLSTR(x, y) (B2C(x) <  B2C(y))
  89 #define GE_CLSTR(x, y) (B2C(x) >= B2C(y))
  90 #define GT_CLSTR(x, y) (B2C(x) >  B2C(y))
  91
  92 static int lazy_itable_init;
  93
  94 /*
  95  * This is the top-level routine which does the dirty deed....
  96  */
  97 errcode_t resize_fs(ext2_filsys fs, blk64_t *new_size, int flags,
  98             errcode_t (*progress)(ext2_resize_t rfs, int pass,
  99                                           unsigned long cur,
 100                                           unsigned long max_val))
 101 {
 102         ext2_resize_t   rfs;
 103         errcode_t       retval;
 104         struct resource_track   rtrack, overall_track;
 105
 106         /*
 107          * Create the data structure
 108          */
 109         retval = ext2fs_get_mem(sizeof(struct ext2_resize_struct), &rfs);
 110         if (retval)
 111                 return retval;
 112
 113         memset(rfs, 0, sizeof(struct ext2_resize_struct));
 114         fs->priv_data = rfs;
 115         rfs->old_fs = fs;
 116         rfs->flags = flags;
 117         rfs->itable_buf  = 0;
 118         rfs->progress = progress;
 119
 120         init_resource_track(&overall_track, "overall resize2fs", fs->io);
 121         init_resource_track(&rtrack, "read_bitmaps", fs->io);
 122         retval = ext2fs_read_bitmaps(fs);
 123         if (retval)
 124                 goto errout;
 125         print_resource_track(rfs, &rtrack, fs->io);
 126
 127         fs->super->s_state |= EXT2_ERROR_FS;
 128         ext2fs_mark_super_dirty(fs);
 129         ext2fs_flush(fs);
 130
 131         init_resource_track(&rtrack, "fix_uninit_block_bitmaps 1", fs->io);
 132         fix_uninit_block_bitmaps(fs);
 133         print_resource_track(rfs, &rtrack, fs->io);
 134         retval = ext2fs_dup_handle(fs, &rfs->new_fs);
 135         if (retval)
 136                 goto errout;
 137
 138         init_resource_track(&rtrack, "resize_group_descriptors", fs->io);
 139         retval = resize_group_descriptors(rfs, *new_size);
 140         if (retval)
 141                 goto errout;
 142         print_resource_track(rfs, &rtrack, fs->io);
 143
 144         init_resource_track(&rtrack, "move_bg_metadata", fs->io);
 145         retval = move_bg_metadata(rfs);
 146         if (retval)
 147                 goto errout;
 148         print_resource_track(rfs, &rtrack, fs->io);
 149
 150         init_resource_track(&rtrack, "zero_high_bits_in_metadata", fs->io);
 151         retval = zero_high_bits_in_inodes(rfs);
 152         if (retval)
 153                 goto errout;
 154         print_resource_track(rfs, &rtrack, fs->io);
 155
 156         init_resource_track(&rtrack, "adjust_superblock", fs->io);
 157         retval = adjust_superblock(rfs, *new_size);
 158         if (retval)
 159                 goto errout;
 160         print_resource_track(rfs, &rtrack, fs->io);
 161
 162         init_resource_track(&rtrack, "fix_uninit_block_bitmaps 2", fs->io);
 163         fix_uninit_block_bitmaps(rfs->new_fs);
 164         print_resource_track(rfs, &rtrack, fs->io);
 165         /* Clear the block bitmap uninit flag for the last block group */
 166         ext2fs_bg_flags_clear(rfs->new_fs, rfs->new_fs->group_desc_count - 1,
 167                              EXT2_BG_BLOCK_UNINIT);
 168
 169         *new_size = ext2fs_blocks_count(rfs->new_fs->super);
 170
 171         init_resource_track(&rtrack, "blocks_to_move", fs->io);
 172         retval = blocks_to_move(rfs);
 173         if (retval)
 174                 goto errout;
 175         print_resource_track(rfs, &rtrack, fs->io);
 176
 177 #ifdef RESIZE2FS_DEBUG
 178         if (rfs->flags & RESIZE_DEBUG_BMOVE)
 179                 printf("Number of free blocks: %llu/%llu, Needed: %llu\n",
 180                        (unsigned long long) ext2fs_free_blocks_count(rfs->old_fs->super),
 181                        (unsigned long long) ext2fs_free_blocks_count(rfs->new_fs->super),
 182                        (unsigned long long) rfs->needed_blocks);
 183 #endif
 184
 185         init_resource_track(&rtrack, "block_mover", fs->io);
 186         retval = block_mover(rfs);
 187         if (retval)
 188                 goto errout;
 189         print_resource_track(rfs, &rtrack, fs->io);
 190
 191         init_resource_track(&rtrack, "inode_scan_and_fix", fs->io);
 192         retval = inode_scan_and_fix(rfs);
 193         if (retval)
 194                 goto errout;
 195         print_resource_track(rfs, &rtrack, fs->io);
 196
 197         init_resource_track(&rtrack, "inode_ref_fix", fs->io);
 198         retval = inode_ref_fix(rfs);
 199         if (retval)
 200                 goto errout;
 201         print_resource_track(rfs, &rtrack, fs->io);
 202
 203         init_resource_track(&rtrack, "move_itables", fs->io);
 204         retval = move_itables(rfs);
 205         if (retval)
 206                 goto errout;
 207         print_resource_track(rfs, &rtrack, fs->io);
 208
 209         retval = clear_sparse_super2_last_group(rfs);
 210         if (retval)
 211                 goto errout;
 212
 213         init_resource_track(&rtrack, "calculate_summary_stats", fs->io);
 214         retval = resize2fs_calculate_summary_stats(rfs->new_fs);
 215         if (retval)
 216                 goto errout;
 217         print_resource_track(rfs, &rtrack, fs->io);
 218
 219         init_resource_track(&rtrack, "fix_resize_inode", fs->io);
 220         retval = fix_resize_inode(rfs->new_fs);
 221         if (retval)
 222                 goto errout;
 223         print_resource_track(rfs, &rtrack, fs->io);
 224
 225         init_resource_track(&rtrack, "fix_sb_journal_backup", fs->io);
 226         retval = fix_sb_journal_backup(rfs->new_fs);
 227         if (retval)
 228                 goto errout;
 229         print_resource_track(rfs, &rtrack, fs->io);
 230
 231         retval = ext2fs_set_gdt_csum(rfs->new_fs);
 232         if (retval)
 233                 goto errout;
 234
 235         rfs->new_fs->super->s_state &= ~EXT2_ERROR_FS;
 236         rfs->new_fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
 237
 238         print_resource_track(rfs, &overall_track, fs->io);
 239         retval = ext2fs_close_free(&rfs->new_fs);
 240         if (retval)
 241                 goto errout;
 242
 243         rfs->flags = flags;
 244
 245         ext2fs_free(rfs->old_fs);
 246         rfs->old_fs = NULL;
 247         if (rfs->itable_buf)
 248                 ext2fs_free_mem(&rfs->itable_buf);
 249         if (rfs->reserve_blocks)
 250                 ext2fs_free_block_bitmap(rfs->reserve_blocks);
 251         if (rfs->move_blocks)
 252                 ext2fs_free_block_bitmap(rfs->move_blocks);
 253         ext2fs_free_mem(&rfs);
 254
 255         return 0;
 256
 257 errout:
 258         if (rfs->new_fs) {
 259                 ext2fs_free(rfs->new_fs);
 260                 rfs->new_fs = NULL;
 261         }
 262         if (rfs->itable_buf)
 263                 ext2fs_free_mem(&rfs->itable_buf);
 264         ext2fs_free_mem(&rfs);
 265         return retval;
 266 }
 267
 268 /* Keep the size of the group descriptor region constant */
 269 static void adjust_reserved_gdt_blocks(ext2_filsys old_fs, ext2_filsys fs)
 270 {
 271         if (ext2fs_has_feature_resize_inode(fs->super) &&
 272             (old_fs->desc_blocks != fs->desc_blocks)) {
 273                 int new;
 274
 275                 new = ((int) fs->super->s_reserved_gdt_blocks) +
 276                         (old_fs->desc_blocks - fs->desc_blocks);
 277                 if (new < 0)
 278                         new = 0;
 279                 if (new > (int) fs->blocksize/4)
 280                         new = fs->blocksize/4;
 281                 fs->super->s_reserved_gdt_blocks = new;
 282         }
 283 }
 284
 285 /* Toggle 64bit mode */
 286 static errcode_t resize_group_descriptors(ext2_resize_t rfs, blk64_t new_size)
 287 {
 288         void *o, *n, *new_group_desc;
 289         dgrp_t i;
 290         int copy_size;
 291         errcode_t retval;
 292
 293         if (!(rfs->flags & (RESIZE_DISABLE_64BIT | RESIZE_ENABLE_64BIT)))
 294                 return 0;
 295
 296         if (new_size != ext2fs_blocks_count(rfs->new_fs->super) ||
 297             ext2fs_blocks_count(rfs->new_fs->super) >= (1ULL << 32) ||
 298             (rfs->flags & RESIZE_DISABLE_64BIT &&
 299              rfs->flags & RESIZE_ENABLE_64BIT))
 300                 return EXT2_ET_INVALID_ARGUMENT;
 301
 302         if (rfs->flags & RESIZE_DISABLE_64BIT) {
 303                 ext2fs_clear_feature_64bit(rfs->new_fs->super);
 304                 rfs->new_fs->super->s_desc_size = EXT2_MIN_DESC_SIZE;
 305         } else if (rfs->flags & RESIZE_ENABLE_64BIT) {
 306                 ext2fs_set_feature_64bit(rfs->new_fs->super);
 307                 rfs->new_fs->super->s_desc_size = EXT2_MIN_DESC_SIZE_64BIT;
 308         }
 309
 310         if (EXT2_DESC_SIZE(rfs->old_fs->super) ==
 311             EXT2_DESC_SIZE(rfs->new_fs->super))
 312                 return 0;
 313
 314         o = rfs->new_fs->group_desc;
 315         rfs->new_fs->desc_blocks = ext2fs_div_ceil(
 316                         rfs->old_fs->group_desc_count,
 317                         EXT2_DESC_PER_BLOCK(rfs->new_fs->super));
 318         retval = ext2fs_get_arrayzero(rfs->new_fs->desc_blocks,
 319                                       rfs->old_fs->blocksize, &new_group_desc);
 320         if (retval)
 321                 return retval;
 322
 323         n = new_group_desc;
 324
 325         if (EXT2_DESC_SIZE(rfs->old_fs->super) <=
 326             EXT2_DESC_SIZE(rfs->new_fs->super))
 327                 copy_size = EXT2_DESC_SIZE(rfs->old_fs->super);
 328         else
 329                 copy_size = EXT2_DESC_SIZE(rfs->new_fs->super);
 330         for (i = 0; i < rfs->old_fs->group_desc_count; i++) {
 331                 memcpy(n, o, copy_size);
 332                 n = (char *)n + EXT2_DESC_SIZE(rfs->new_fs->super);
 333                 o = (char *)o + EXT2_DESC_SIZE(rfs->old_fs->super);
 334         }
 335
 336         ext2fs_free_mem(&rfs->new_fs->group_desc);
 337         rfs->new_fs->group_desc = new_group_desc;
 338
 339         for (i = 0; i < rfs->old_fs->group_desc_count; i++)
 340                 ext2fs_group_desc_csum_set(rfs->new_fs, i);
 341
 342         adjust_reserved_gdt_blocks(rfs->old_fs, rfs->new_fs);
 343
 344         return 0;
 345 }
 346
 347 /* Move bitmaps/inode tables out of the way. */
 348 static errcode_t move_bg_metadata(ext2_resize_t rfs)
 349 {
 350         dgrp_t i;
 351         blk64_t b, c, d, old_desc_blocks, new_desc_blocks, j;
 352         ext2fs_block_bitmap old_map, new_map;
 353         int old, new;
 354         errcode_t retval;
 355         int cluster_ratio;
 356
 357         if (!(rfs->flags & (RESIZE_DISABLE_64BIT | RESIZE_ENABLE_64BIT)))
 358                 return 0;
 359
 360         retval = ext2fs_allocate_block_bitmap(rfs->old_fs, "oldfs", &old_map);
 361         if (retval)
 362                 return retval;
 363
 364         retval = ext2fs_allocate_block_bitmap(rfs->new_fs, "newfs", &new_map);
 365         if (retval)
 366                 goto out;
 367
 368         if (ext2fs_has_feature_meta_bg(rfs->old_fs->super)) {
 369                 old_desc_blocks = rfs->old_fs->super->s_first_meta_bg;
 370                 new_desc_blocks = rfs->new_fs->super->s_first_meta_bg;
 371         } else {
 372                 old_desc_blocks = rfs->old_fs->desc_blocks +
 373                                 rfs->old_fs->super->s_reserved_gdt_blocks;
 374                 new_desc_blocks = rfs->new_fs->desc_blocks +
 375                                 rfs->new_fs->super->s_reserved_gdt_blocks;
 376         }
 377
 378         /* Construct bitmaps of super/descriptor blocks in old and new fs */
 379         for (i = 0; i < rfs->old_fs->group_desc_count; i++) {
 380                 retval = ext2fs_super_and_bgd_loc2(rfs->old_fs, i, &b, &c, &d,
 381                                                    NULL);
 382                 if (retval)
 383                         goto out;
 384                 if (b)
 385                         ext2fs_mark_block_bitmap2(old_map, b);
 386                 for (j = 0; c != 0 && j < old_desc_blocks; j++)
 387                         ext2fs_mark_block_bitmap2(old_map, c + j);
 388                 if (d)
 389                         ext2fs_mark_block_bitmap2(old_map, d);
 390
 391                 retval = ext2fs_super_and_bgd_loc2(rfs->new_fs, i, &b, &c, &d,
 392                                                    NULL);
 393                 if (retval)
 394                         goto out;
 395                 if (b)
 396                         ext2fs_mark_block_bitmap2(new_map, b);
 397                 for (j = 0; c != 0 && j < new_desc_blocks; j++)
 398                         ext2fs_mark_block_bitmap2(new_map, c + j);
 399                 if (d)
 400                         ext2fs_mark_block_bitmap2(new_map, d);
 401         }
 402
 403         cluster_ratio = EXT2FS_CLUSTER_RATIO(rfs->new_fs);
 404
 405         /* Find changes in block allocations for bg metadata */
 406         for (b = EXT2FS_B2C(rfs->old_fs,
 407                             rfs->old_fs->super->s_first_data_block);
 408              b < ext2fs_blocks_count(rfs->new_fs->super);
 409              b += cluster_ratio) {
 410                 old = ext2fs_test_block_bitmap2(old_map, b);
 411                 new = ext2fs_test_block_bitmap2(new_map, b);
 412
 413                 if (old && !new) {
 414                         /* mark old_map, unmark new_map */
 415                         if (cluster_ratio == 1)
 416                                 ext2fs_unmark_block_bitmap2(
 417                                                 rfs->new_fs->block_map, b);
 418                 } else if (!old && new)
 419                         ; /* unmark old_map, mark new_map */
 420                 else {
 421                         ext2fs_unmark_block_bitmap2(old_map, b);
 422                         ext2fs_unmark_block_bitmap2(new_map, b);
 423                 }
 424         }
 425
 426         /*
 427          * new_map now shows blocks that have been newly allocated.
 428          * old_map now shows blocks that have been newly freed.
 429          */
 430
 431         /*
 432          * Move any conflicting bitmaps and inode tables.  Ensure that we
 433          * don't try to free clusters associated with bitmaps or tables.
 434          */
 435         for (i = 0; i < rfs->old_fs->group_desc_count; i++) {
 436                 b = ext2fs_block_bitmap_loc(rfs->new_fs, i);
 437                 if (ext2fs_test_block_bitmap2(new_map, b))
 438                         ext2fs_block_bitmap_loc_set(rfs->new_fs, i, 0);
 439                 else if (ext2fs_test_block_bitmap2(old_map, b))
 440                         ext2fs_unmark_block_bitmap2(old_map, b);
 441
 442                 b = ext2fs_inode_bitmap_loc(rfs->new_fs, i);
 443                 if (ext2fs_test_block_bitmap2(new_map, b))
 444                         ext2fs_inode_bitmap_loc_set(rfs->new_fs, i, 0);
 445                 else if (ext2fs_test_block_bitmap2(old_map, b))
 446                         ext2fs_unmark_block_bitmap2(old_map, b);
 447
 448                 c = ext2fs_inode_table_loc(rfs->new_fs, i);
 449                 for (b = 0;
 450                      b < rfs->new_fs->inode_blocks_per_group;
 451                      b++) {
 452                         if (ext2fs_test_block_bitmap2(new_map, b + c))
 453                                 ext2fs_inode_table_loc_set(rfs->new_fs, i, 0);
 454                         else if (ext2fs_test_block_bitmap2(old_map, b + c))
 455                                 ext2fs_unmark_block_bitmap2(old_map, b + c);
 456                 }
 457         }
 458
 459         /* Free unused clusters */
 460         for (b = 0;
 461              cluster_ratio > 1 && b < ext2fs_blocks_count(rfs->new_fs->super);
 462              b += cluster_ratio)
 463                 if (ext2fs_test_block_bitmap2(old_map, b))
 464                         ext2fs_unmark_block_bitmap2(rfs->new_fs->block_map, b);
 465 out:
 466         if (old_map)
 467                 ext2fs_free_block_bitmap(old_map);
 468         if (new_map)
 469                 ext2fs_free_block_bitmap(new_map);
 470         return retval;
 471 }
 472
 473 /* Zero out the high bits of extent fields */
 474 static errcode_t zero_high_bits_in_extents(ext2_filsys fs, ext2_ino_t ino,
 475                                  struct ext2_inode *inode)
 476 {
 477         ext2_extent_handle_t    handle;
 478         struct ext2fs_extent    extent;
 479         int                     op = EXT2_EXTENT_ROOT;
 480         errcode_t               errcode;
 481
 482         if (!(inode->i_flags & EXT4_EXTENTS_FL))
 483                 return 0;
 484
 485         errcode = ext2fs_extent_open(fs, ino, &handle);
 486         if (errcode)
 487                 return errcode;
 488
 489         while (1) {
 490                 errcode = ext2fs_extent_get(handle, op, &extent);
 491                 if (errcode)
 492                         break;
 493
 494                 op = EXT2_EXTENT_NEXT_SIB;
 495
 496                 if (extent.e_pblk > (1ULL << 32)) {
 497                         extent.e_pblk &= (1ULL << 32) - 1;
 498                         errcode = ext2fs_extent_replace(handle, 0, &extent);
 499                         if (errcode)
 500                                 break;
 501                 }
 502         }
 503
 504         /* Ok if we run off the end */
 505         if (errcode == EXT2_ET_EXTENT_NO_NEXT)
 506                 errcode = 0;
 507         ext2fs_extent_free(handle);
 508         return errcode;
 509 }
 510
 511 /* Zero out the high bits of inodes. */
 512 static errcode_t zero_high_bits_in_inodes(ext2_resize_t rfs)
 513 {
 514         ext2_filsys     fs = rfs->old_fs;
 515         int length = EXT2_INODE_SIZE(fs->super);
 516         struct ext2_inode *inode = NULL;
 517         ext2_inode_scan scan = NULL;
 518         errcode_t       retval;
 519         ext2_ino_t      ino;
 520
 521         if (!(rfs->flags & (RESIZE_DISABLE_64BIT | RESIZE_ENABLE_64BIT)))
 522                 return 0;
 523
 524         if (fs->super->s_creator_os == EXT2_OS_HURD)
 525                 return 0;
 526
 527         retval = ext2fs_open_inode_scan(fs, 0, &scan);
 528         if (retval)
 529                 return retval;
 530
 531         retval = ext2fs_get_mem(length, &inode);
 532         if (retval)
 533                 goto out;
 534
 535         do {
 536                 retval = ext2fs_get_next_inode_full(scan, &ino, inode, length);
 537                 if (retval)
 538                         goto out;
 539                 if (!ino)
 540                         break;
 541                 if (!ext2fs_test_inode_bitmap2(fs->inode_map, ino))
 542                         continue;
 543
 544                 /*
 545                  * Here's how we deal with high block number fields:
 546                  *
 547                  *  - i_size_high has been been written out with i_size_lo
 548                  *    since the ext2 days, so no conversion is needed.
 549                  *
 550                  *  - i_blocks_hi is guarded by both the huge_file feature and
 551                  *    inode flags and has always been written out with
 552                  *    i_blocks_lo if the feature is set.  The field is only
 553                  *    ever read if both feature and inode flag are set, so
 554                  *    we don't need to zero it now.
 555                  *
 556                  *  - i_file_acl_high can be uninitialized, so zero it if
 557                  *    it isn't already.
 558                  */
 559                 if (inode->osd2.linux2.l_i_file_acl_high) {
 560                         inode->osd2.linux2.l_i_file_acl_high = 0;
 561                         retval = ext2fs_write_inode_full(fs, ino, inode,
 562                                                          length);
 563                         if (retval)
 564                                 goto out;
 565                 }
 566
 567                 retval = zero_high_bits_in_extents(fs, ino, inode);
 568                 if (retval)
 569                         goto out;
 570         } while (ino);
 571
 572 out:
 573         if (inode)
 574                 ext2fs_free_mem(&inode);
 575         if (scan)
 576                 ext2fs_close_inode_scan(scan);
 577         return retval;
 578 }
 579
 580 /*
 581  * Clean up the bitmaps for uninitialized bitmaps
 582  */
 583 static void fix_uninit_block_bitmaps(ext2_filsys fs)
 584 {
 585         blk64_t         blk, lblk;
 586         dgrp_t          g;
 587         unsigned int    i;
 588
 589         if (!ext2fs_has_group_desc_csum(fs))
 590                 return;
 591
 592         for (g=0; g < fs->group_desc_count; g++) {
 593                 if (!(ext2fs_bg_flags_test(fs, g, EXT2_BG_BLOCK_UNINIT)))
 594                         continue;
 595
 596                 blk = ext2fs_group_first_block2(fs, g);
 597                 lblk = ext2fs_group_last_block2(fs, g);
 598                 ext2fs_unmark_block_bitmap_range2(fs->block_map, blk,
 599                                                   lblk - blk + 1);
 600
 601                 ext2fs_reserve_super_and_bgd(fs, g, fs->block_map);
 602                 ext2fs_mark_block_bitmap2(fs->block_map,
 603                                           ext2fs_block_bitmap_loc(fs, g));
 604                 ext2fs_mark_block_bitmap2(fs->block_map,
 605                                           ext2fs_inode_bitmap_loc(fs, g));
 606                 for (i = 0, blk = ext2fs_inode_table_loc(fs, g);
 607                      i < fs->inode_blocks_per_group;
 608                      i++, blk++)
 609                         ext2fs_mark_block_bitmap2(fs->block_map, blk);
 610         }
 611 }
 612
 613 /* --------------------------------------------------------------------
 614  *
 615  * Resize processing, phase 1.
 616  *
 617  * In this phase we adjust the in-memory superblock information, and
 618  * initialize any new parts of the inode table.  The new parts of the
 619  * inode table are created in virgin disk space, so we can abort here
 620  * without any side effects.
 621  * --------------------------------------------------------------------
 622  */
 623
 624 /*
 625  * If the group descriptor's bitmap and inode table blocks are valid,
 626  * release them in the new filesystem data structure, and mark them as
 627  * reserved so the old inode table blocks don't get overwritten.
 628  */
 629 static errcode_t free_gdp_blocks(ext2_filsys fs,
 630                                  ext2fs_block_bitmap reserve_blocks,
 631                                  ext2_filsys old_fs,
 632                                  dgrp_t group)
 633 {
 634         blk64_t         blk;
 635         unsigned int    j;
 636         dgrp_t          i;
 637         ext2fs_block_bitmap bg_map = NULL;
 638         errcode_t       retval = 0;
 639         dgrp_t          count = old_fs->group_desc_count - fs->group_desc_count;
 640
 641         /* If bigalloc, don't free metadata living in the same cluster */
 642         if (EXT2FS_CLUSTER_RATIO(fs) > 1) {
 643                 retval = ext2fs_allocate_block_bitmap(fs, "bgdata", &bg_map);
 644                 if (retval)
 645                         goto out;
 646
 647                 retval = mark_table_blocks(fs, bg_map);
 648                 if (retval)
 649                         goto out;
 650         }
 651
 652         for (i = group; i < group + count; i++) {
 653                 blk = ext2fs_block_bitmap_loc(old_fs, i);
 654                 if (blk &&
 655                     (blk < ext2fs_blocks_count(fs->super)) &&
 656                     !(bg_map && ext2fs_test_block_bitmap2(bg_map, blk))) {
 657                         ext2fs_block_alloc_stats2(fs, blk, -1);
 658                         ext2fs_mark_block_bitmap2(reserve_blocks, blk);
 659                 }
 660
 661                 blk = ext2fs_inode_bitmap_loc(old_fs, i);
 662                 if (blk &&
 663                     (blk < ext2fs_blocks_count(fs->super)) &&
 664                     !(bg_map && ext2fs_test_block_bitmap2(bg_map, blk))) {
 665                         ext2fs_block_alloc_stats2(fs, blk, -1);
 666                         ext2fs_mark_block_bitmap2(reserve_blocks, blk);
 667                 }
 668
 669                 blk = ext2fs_inode_table_loc(old_fs, i);
 670                 for (j = 0;
 671                      j < fs->inode_blocks_per_group; j++, blk++) {
 672                         if (blk >= ext2fs_blocks_count(fs->super) ||
 673                             (bg_map && ext2fs_test_block_bitmap2(bg_map, blk)))
 674                                 continue;
 675                         ext2fs_block_alloc_stats2(fs, blk, -1);
 676                         ext2fs_mark_block_bitmap2(reserve_blocks, blk);
 677                 }
 678         }
 679
 680 out:
 681         if (bg_map)
 682                 ext2fs_free_block_bitmap(bg_map);
 683         return retval;
 684 }
 685
 686 /*
 687  * This routine is shared by the online and offline resize routines.
 688  * All of the information which is adjusted in memory is done here.
 689  */
 690 errcode_t adjust_fs_info(ext2_filsys fs, ext2_filsys old_fs,
 691                          ext2fs_block_bitmap reserve_blocks, blk64_t new_size)
 692 {
 693         errcode_t       retval;
 694         blk64_t         overhead = 0;
 695         blk64_t         rem;
 696         blk64_t         blk, group_block;
 697         blk64_t         real_end;
 698         blk64_t         old_numblocks, numblocks, adjblocks;
 699         unsigned long   i, j, old_desc_blocks;
 700         unsigned int    meta_bg, meta_bg_size;
 701         int             has_super, csum_flag, has_bg;
 702         unsigned long long new_inodes;  /* u64 to check for overflow */
 703         double          percent;
 704
 705         ext2fs_blocks_count_set(fs->super, new_size);
 706         fs->super->s_overhead_clusters = 0;
 707
 708 retry:
 709         fs->group_desc_count = ext2fs_div64_ceil(ext2fs_blocks_count(fs->super) -
 710                                        fs->super->s_first_data_block,
 711                                        EXT2_BLOCKS_PER_GROUP(fs->super));
 712         if (fs->group_desc_count == 0)
 713                 return EXT2_ET_TOOSMALL;
 714         fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count,
 715                                           EXT2_DESC_PER_BLOCK(fs->super));
 716
 717         /*
 718          * Overhead is the number of bookkeeping blocks per group.  It
 719          * includes the superblock backup, the group descriptor
 720          * backups, the inode bitmap, the block bitmap, and the inode
 721          * table.
 722          */
 723         overhead = (int) (2 + fs->inode_blocks_per_group);
 724
 725         has_bg = 0;
 726         if (ext2fs_has_feature_sparse_super2(fs->super)) {
 727                 /*
 728                  * We have to do this manually since
 729                  * super->s_backup_bgs hasn't been set up yet.
 730                  */
 731                 if (fs->group_desc_count == 2)
 732                         has_bg = fs->super->s_backup_bgs[0] != 0;
 733                 else
 734                         has_bg = fs->super->s_backup_bgs[1] != 0;
 735         } else
 736                 has_bg = ext2fs_bg_has_super(fs, fs->group_desc_count - 1);
 737         if (has_bg)
 738                 overhead += 1 + fs->desc_blocks +
 739                         fs->super->s_reserved_gdt_blocks;
 740
 741         /*
 742          * See if the last group is big enough to support the
 743          * necessary data structures.  If not, we need to get rid of
 744          * it.
 745          */
 746         rem = (ext2fs_blocks_count(fs->super) - fs->super->s_first_data_block) %
 747                 fs->super->s_blocks_per_group;
 748         if ((fs->group_desc_count == 1) && rem && (rem < overhead))
 749                 return EXT2_ET_TOOSMALL;
 750         if ((fs->group_desc_count > 1) && rem && (rem < overhead+50)) {
 751                 ext2fs_blocks_count_set(fs->super,
 752                                         ext2fs_blocks_count(fs->super) - rem);
 753                 goto retry;
 754         }
 755         /*
 756          * Adjust the number of inodes
 757          */
 758         new_inodes =(unsigned long long) fs->super->s_inodes_per_group * fs->group_desc_count;
 759         if (new_inodes > ~0U) {
 760                 fprintf(stderr, _("inodes (%llu) must be less than %u\n"),
 761                         (unsigned long long) new_inodes, ~0U);
 762                 return EXT2_ET_TOO_MANY_INODES;
 763         }
 764         fs->super->s_inodes_count = fs->super->s_inodes_per_group *
 765                 fs->group_desc_count;
 766
 767         /*
 768          * Adjust the number of free blocks
 769          */
 770         blk = ext2fs_blocks_count(old_fs->super);
 771         if (blk > ext2fs_blocks_count(fs->super))
 772                 ext2fs_free_blocks_count_set(fs->super,
 773                         ext2fs_free_blocks_count(fs->super) -
 774                         (blk - ext2fs_blocks_count(fs->super)));
 775         else
 776                 ext2fs_free_blocks_count_set(fs->super,
 777                         ext2fs_free_blocks_count(fs->super) +
 778                         (ext2fs_blocks_count(fs->super) - blk));
 779
 780         /*
 781          * Adjust the number of reserved blocks
 782          */
 783         percent = (ext2fs_r_blocks_count(old_fs->super) * 100.0) /
 784                 ext2fs_blocks_count(old_fs->super);
 785         ext2fs_r_blocks_count_set(fs->super,
 786                                   (percent * ext2fs_blocks_count(fs->super) /
 787                                    100.0));
 788
 789         /*
 790          * Adjust the bitmaps for size
 791          */
 792         retval = ext2fs_resize_inode_bitmap2(fs->super->s_inodes_count,
 793                                             fs->super->s_inodes_count,
 794                                             fs->inode_map);
 795         if (retval) goto errout;
 796
 797         real_end = EXT2_GROUPS_TO_BLOCKS(fs->super, fs->group_desc_count) - 1 +
 798                 fs->super->s_first_data_block;
 799         retval = ext2fs_resize_block_bitmap2(new_size - 1,
 800                                              real_end, fs->block_map);
 801         if (retval) goto errout;
 802
 803         /*
 804          * If we are growing the file system, also grow the size of
 805          * the reserve_blocks bitmap
 806          */
 807         if (reserve_blocks && new_size > ext2fs_blocks_count(old_fs->super)) {
 808                 retval = ext2fs_resize_block_bitmap2(new_size - 1,
 809                                                      real_end, reserve_blocks);
 810                 if (retval) goto errout;
 811         }
 812
 813         /*
 814          * Reallocate the group descriptors as necessary.
 815          */
 816         if (EXT2_DESC_SIZE(old_fs->super) == EXT2_DESC_SIZE(fs->super) &&
 817             old_fs->desc_blocks != fs->desc_blocks) {
 818                 retval = ext2fs_resize_mem(old_fs->desc_blocks *
 819                                            fs->blocksize,
 820                                            fs->desc_blocks * fs->blocksize,
 821                                            &fs->group_desc);
 822                 if (retval)
 823                         goto errout;
 824                 if (fs->desc_blocks > old_fs->desc_blocks)
 825                         memset((char *) fs->group_desc +
 826                                (old_fs->desc_blocks * fs->blocksize), 0,
 827                                (fs->desc_blocks - old_fs->desc_blocks) *
 828                                fs->blocksize);
 829         }
 830
 831         /*
 832          * If the resize_inode feature is set, and we are changing the
 833          * number of descriptor blocks, then adjust
 834          * s_reserved_gdt_blocks if possible to avoid needing to move
 835          * the inode table either now or in the future.
 836          *
 837          * Note: If we're converting to 64bit mode, we did this earlier.
 838          */
 839         if (EXT2_DESC_SIZE(old_fs->super) == EXT2_DESC_SIZE(fs->super))
 840                 adjust_reserved_gdt_blocks(old_fs, fs);
 841
 842         if (ext2fs_has_feature_meta_bg(fs->super) &&
 843             (fs->super->s_first_meta_bg > fs->desc_blocks)) {
 844                 ext2fs_clear_feature_meta_bg(fs->super);
 845                 fs->super->s_first_meta_bg = 0;
 846         }
 847
 848         /*
 849          * Update the location of the backup superblocks if the
 850          * sparse_super2 feature is enabled.
 851          */
 852         if (ext2fs_has_feature_sparse_super2(fs->super)) {
 853                 dgrp_t last_bg = fs->group_desc_count - 1;
 854                 dgrp_t old_last_bg = old_fs->group_desc_count - 1;
 855
 856                 if (last_bg > old_last_bg) {
 857                         if (old_fs->group_desc_count == 1)
 858                                 fs->super->s_backup_bgs[0] = 1;
 859                         if ((old_fs->group_desc_count < 3 &&
 860                              fs->group_desc_count > 2) ||
 861                             fs->super->s_backup_bgs[1])
 862                                 fs->super->s_backup_bgs[1] = last_bg;
 863                 } else if (last_bg < old_last_bg) {
 864                         if (fs->super->s_backup_bgs[0] > last_bg)
 865                                 fs->super->s_backup_bgs[0] = 0;
 866                         if (fs->super->s_backup_bgs[1] > last_bg)
 867                                 fs->super->s_backup_bgs[1] = 0;
 868                         if (last_bg > 1 &&
 869                             old_fs->super->s_backup_bgs[1] == old_last_bg)
 870                                 fs->super->s_backup_bgs[1] = last_bg;
 871                 }
 872         }
 873
 874         /*
 875          * If we are shrinking the number of block groups, we're done
 876          * and can exit now.
 877          */
 878         if (old_fs->group_desc_count > fs->group_desc_count) {
 879                 /*
 880                  * Check the block groups that we are chopping off
 881                  * and free any blocks associated with their metadata
 882                  */
 883                 retval = free_gdp_blocks(fs, reserve_blocks, old_fs,
 884                                          fs->group_desc_count);
 885                 goto errout;
 886         }
 887
 888         /*
 889          * Fix the count of the last (old) block group
 890          */
 891         old_numblocks = (ext2fs_blocks_count(old_fs->super) -
 892                          old_fs->super->s_first_data_block) %
 893                                  old_fs->super->s_blocks_per_group;
 894         if (!old_numblocks)
 895                 old_numblocks = old_fs->super->s_blocks_per_group;
 896         if (old_fs->group_desc_count == fs->group_desc_count) {
 897                 numblocks = (ext2fs_blocks_count(fs->super) -
 898                              fs->super->s_first_data_block) %
 899                         fs->super->s_blocks_per_group;
 900                 if (!numblocks)
 901                         numblocks = fs->super->s_blocks_per_group;
 902         } else
 903                 numblocks = fs->super->s_blocks_per_group;
 904         i = old_fs->group_desc_count - 1;
 905         ext2fs_bg_free_blocks_count_set(fs, i, ext2fs_bg_free_blocks_count(fs, i) + (numblocks - old_numblocks));
 906         ext2fs_group_desc_csum_set(fs, i);
 907
 908         /*
 909          * If the number of block groups is staying the same, we're
 910          * done and can exit now.  (If the number block groups is
 911          * shrinking, we had exited earlier.)
 912          */
 913         if (old_fs->group_desc_count >= fs->group_desc_count) {
 914                 retval = 0;
 915                 goto errout;
 916         }
 917
 918         /*
 919          * Initialize the new block group descriptors
 920          */
 921         group_block = ext2fs_group_first_block2(fs,
 922                                                 old_fs->group_desc_count);
 923         csum_flag = ext2fs_has_group_desc_csum(fs);
 924         if (getenv("RESIZE2FS_FORCE_LAZY_ITABLE_INIT") ||
 925             (!getenv("RESIZE2FS_FORCE_ITABLE_INIT") &&
 926              access("/sys/fs/ext4/features/lazy_itable_init", F_OK) == 0))
 927                 lazy_itable_init = 1;
 928         if (ext2fs_has_feature_meta_bg(fs->super))
 929                 old_desc_blocks = fs->super->s_first_meta_bg;
 930         else
 931                 old_desc_blocks = fs->desc_blocks +
 932                         fs->super->s_reserved_gdt_blocks;
 933
 934         /*
 935          * If we changed the number of block_group descriptor blocks,
 936          * we need to make sure they are all marked as reserved in the
 937          * filesystem's block allocation map.
 938          */
 939         for (i = 0; i < old_fs->group_desc_count; i++)
 940                 ext2fs_reserve_super_and_bgd(fs, i, fs->block_map);
 941
 942         for (i = old_fs->group_desc_count;
 943              i < fs->group_desc_count; i++) {
 944                 memset(ext2fs_group_desc(fs, fs->group_desc, i), 0,
 945                        sizeof(struct ext2_group_desc));
 946                 adjblocks = 0;
 947
 948                 ext2fs_bg_flags_zap(fs, i);
 949                 if (csum_flag) {
 950                         ext2fs_bg_flags_set(fs, i, EXT2_BG_INODE_UNINIT);
 951                         if (!lazy_itable_init)
 952                                 ext2fs_bg_flags_set(fs, i,
 953                                                     EXT2_BG_INODE_ZEROED);
 954                         ext2fs_bg_itable_unused_set(fs, i,
 955                                         fs->super->s_inodes_per_group);
 956                 }
 957
 958                 numblocks = ext2fs_group_blocks_count(fs, i);
 959                 if ((i < fs->group_desc_count - 1) && csum_flag)
 960                         ext2fs_bg_flags_set(fs, i, EXT2_BG_BLOCK_UNINIT);
 961
 962                 has_super = ext2fs_bg_has_super(fs, i);
 963                 if (has_super) {
 964                         ext2fs_block_alloc_stats2(fs, group_block, +1);
 965                         adjblocks++;
 966                 }
 967                 meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
 968                 meta_bg = i / meta_bg_size;
 969                 if (!ext2fs_has_feature_meta_bg(fs->super) ||
 970                     (meta_bg < fs->super->s_first_meta_bg)) {
 971                         if (has_super) {
 972                                 for (j=0; j < old_desc_blocks; j++)
 973                                         ext2fs_block_alloc_stats2(fs,
 974                                                  group_block + 1 + j, +1);
 975                                 adjblocks += old_desc_blocks;
 976                         }
 977                 } else {
 978                         if (has_super)
 979                                 has_super = 1;
 980                         if (((i % meta_bg_size) == 0) ||
 981                             ((i % meta_bg_size) == 1) ||
 982                             ((i % meta_bg_size) == (meta_bg_size-1)))
 983                                 ext2fs_block_alloc_stats2(fs,
 984                                                  group_block + has_super, +1);
 985                 }
 986
 987                 adjblocks += 2 + fs->inode_blocks_per_group;
 988
 989                 numblocks -= adjblocks;
 990                 ext2fs_free_blocks_count_set(fs->super,
 991                              ext2fs_free_blocks_count(fs->super) - adjblocks);
 992                 fs->super->s_free_inodes_count +=
 993                         fs->super->s_inodes_per_group;
 994                 ext2fs_bg_free_blocks_count_set(fs, i, numblocks);
 995                 ext2fs_bg_free_inodes_count_set(fs, i,
 996                                                 fs->super->s_inodes_per_group);
 997                 ext2fs_bg_used_dirs_count_set(fs, i, 0);
 998                 ext2fs_group_desc_csum_set(fs, i);
 999
1000                 retval = ext2fs_allocate_group_table(fs, i, 0);
1001                 if (retval) goto errout;
1002
1003                 group_block += fs->super->s_blocks_per_group;
1004         }
1005         retval = 0;
1006
1007         /*
1008          * Mark all of the metadata blocks as reserved so they won't
1009          * get allocated by the call to ext2fs_allocate_group_table()
1010          * in blocks_to_move(), where we allocate new blocks to
1011          * replace those allocation bitmap and inode table blocks
1012          * which have to get relocated to make space for an increased
1013          * number of the block group descriptors.
1014          */
1015         if (reserve_blocks)
1016                 mark_table_blocks(fs, reserve_blocks);
1017
1018 errout:
1019         return (retval);
1020 }
1021
1022 /*
1023  * This routine adjusts the superblock and other data structures, both
1024  * in disk as well as in memory...
1025  */
1026 static errcode_t adjust_superblock(ext2_resize_t rfs, blk64_t new_size)
1027 {
1028         ext2_filsys     fs = rfs->new_fs;
1029         int             adj = 0;
1030         errcode_t       retval;
1031         blk64_t         group_block;
1032         unsigned long   i;
1033         unsigned long   max_group;
1034
1035         ext2fs_mark_super_dirty(fs);
1036         ext2fs_mark_bb_dirty(fs);
1037         ext2fs_mark_ib_dirty(fs);
1038
1039         retval = ext2fs_allocate_block_bitmap(fs, _("reserved blocks"),
1040                                               &rfs->reserve_blocks);
1041         if (retval)
1042                 return retval;
1043
1044         retval = adjust_fs_info(fs, rfs->old_fs, rfs->reserve_blocks, new_size);
1045         if (retval)
1046                 goto errout;
1047
1048         /*
1049          * Check to make sure there are enough inodes
1050          */
1051         if ((rfs->old_fs->super->s_inodes_count -
1052              rfs->old_fs->super->s_free_inodes_count) >
1053             rfs->new_fs->super->s_inodes_count) {
1054                 retval = ENOSPC;
1055                 goto errout;
1056         }
1057
1058         /*
1059          * If we are shrinking the number block groups, we're done and
1060          * can exit now.
1061          */
1062         if (rfs->old_fs->group_desc_count > fs->group_desc_count) {
1063                 retval = 0;
1064                 goto errout;
1065         }
1066
1067         /*
1068          * If the number of block groups is staying the same, we're
1069          * done and can exit now.  (If the number block groups is
1070          * shrinking, we had exited earlier.)
1071          */
1072         if (rfs->old_fs->group_desc_count >= fs->group_desc_count) {
1073                 retval = 0;
1074                 goto errout;
1075         }
1076
1077         /*
1078          * If we are using uninit_bg (aka GDT_CSUM) and the kernel
1079          * supports lazy inode initialization, we can skip
1080          * initializing the inode table.
1081          */
1082         if (lazy_itable_init && ext2fs_has_group_desc_csum(fs)) {
1083                 retval = 0;
1084                 goto errout;
1085         }
1086
1087         /*
1088          * Initialize the inode table
1089          */
1090         retval = ext2fs_get_array(fs->blocksize, fs->inode_blocks_per_group,
1091                                 &rfs->itable_buf);
1092         if (retval)
1093                 goto errout;
1094
1095         memset(rfs->itable_buf, 0, fs->blocksize * fs->inode_blocks_per_group);
1096         group_block = ext2fs_group_first_block2(fs,
1097                                                 rfs->old_fs->group_desc_count);
1098         adj = rfs->old_fs->group_desc_count;
1099         max_group = fs->group_desc_count - adj;
1100         if (rfs->progress) {
1101                 retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
1102                                        0, max_group);
1103                 if (retval)
1104                         goto errout;
1105         }
1106         for (i = rfs->old_fs->group_desc_count;
1107              i < fs->group_desc_count; i++) {
1108                 /*
1109                  * Write out the new inode table
1110                  */
1111                 retval = ext2fs_zero_blocks2(fs, ext2fs_inode_table_loc(fs, i),
1112                                              fs->inode_blocks_per_group, NULL,
1113                                              NULL);
1114                 if (retval)
1115                         goto errout;
1116
1117                 io_channel_flush(fs->io);
1118                 if (rfs->progress) {
1119                         retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
1120                                                i - adj + 1, max_group);
1121                         if (retval)
1122                                 goto errout;
1123                 }
1124                 group_block += fs->super->s_blocks_per_group;
1125         }
1126         io_channel_flush(fs->io);
1127         retval = 0;
1128
1129 errout:
1130         return retval;
1131 }
1132
1133 /* --------------------------------------------------------------------
1134  *
1135  * Resize processing, phase 2.
1136  *
1137  * In this phase we adjust determine which blocks need to be moved, in
1138  * blocks_to_move().  We then copy the blocks to their ultimate new
1139  * destinations using block_mover().  Since we are copying blocks to
1140  * their new locations, again during this pass we can abort without
1141  * any problems.
1142  * --------------------------------------------------------------------
1143  */
1144
1145 /*
1146  * This helper function creates a block bitmap with all of the
1147  * filesystem meta-data blocks.
1148  */
1149 static errcode_t mark_table_blocks(ext2_filsys fs,
1150                                    ext2fs_block_bitmap bmap)
1151 {
1152         dgrp_t                  i;
1153         blk64_t                 blk;
1154
1155         for (i = 0; i < fs->group_desc_count; i++) {
1156                 ext2fs_reserve_super_and_bgd(fs, i, bmap);
1157
1158                 /*
1159                  * Mark the blocks used for the inode table
1160                  */
1161                 blk = ext2fs_inode_table_loc(fs, i);
1162                 if (blk)
1163                         ext2fs_mark_block_bitmap_range2(bmap, blk,
1164                                                 fs->inode_blocks_per_group);
1165
1166                 /*
1167                  * Mark block used for the block bitmap
1168                  */
1169                 blk = ext2fs_block_bitmap_loc(fs, i);
1170                 if (blk)
1171                         ext2fs_mark_block_bitmap2(bmap, blk);
1172
1173                 /*
1174                  * Mark block used for the inode bitmap
1175                  */
1176                 blk = ext2fs_inode_bitmap_loc(fs, i);
1177                 if (blk)
1178                         ext2fs_mark_block_bitmap2(bmap, blk);
1179         }
1180         return 0;
1181 }
1182
1183 /*
1184  * This function checks to see if a particular block (either a
1185  * superblock or a block group descriptor) overlaps with an inode or
1186  * block bitmap block, or with the inode table.
1187  */
1188 static void mark_fs_metablock(ext2_resize_t rfs,
1189                               ext2fs_block_bitmap meta_bmap,
1190                               int group, blk64_t blk)
1191 {
1192         ext2_filsys fs = rfs->new_fs;
1193
1194         ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
1195         ext2fs_block_alloc_stats2(fs, blk, +1);
1196
1197         /*
1198          * Check to see if we overlap with the inode or block bitmap,
1199          * or the inode tables.  If not, and the block is in use, then
1200          * mark it as a block to be moved.
1201          */
1202         if (is_block_bm(fs, group, blk)) {
1203                 ext2fs_block_bitmap_loc_set(fs, group, 0);
1204                 rfs->needed_blocks++;
1205                 return;
1206         }
1207         if (is_inode_bm(fs, group, blk)) {
1208                 ext2fs_inode_bitmap_loc_set(fs, group, 0);
1209                 rfs->needed_blocks++;
1210                 return;
1211         }
1212         if (is_inode_tb(fs, group, blk)) {
1213                 ext2fs_inode_table_loc_set(fs, group, 0);
1214                 rfs->needed_blocks++;
1215                 return;
1216         }
1217         if (ext2fs_has_feature_flex_bg(fs->super)) {
1218                 dgrp_t i;
1219
1220                 for (i = 0; i < rfs->old_fs->group_desc_count; i++) {
1221                         if (is_block_bm(fs, i, blk)) {
1222                                 ext2fs_block_bitmap_loc_set(fs, i, 0);
1223                                 rfs->needed_blocks++;
1224                                 return;
1225                         }
1226                         if (is_inode_bm(fs, i, blk)) {
1227                                 ext2fs_inode_bitmap_loc_set(fs, i, 0);
1228                                 rfs->needed_blocks++;
1229                                 return;
1230                         }
1231                         if (is_inode_tb(fs, i, blk)) {
1232                                 ext2fs_inode_table_loc_set(fs, i, 0);
1233                                 rfs->needed_blocks++;
1234                                 return;
1235                         }
1236                 }
1237         }
1238
1239         if (ext2fs_has_group_desc_csum(fs) &&
1240             (ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT))) {
1241                 /*
1242                  * If the block bitmap is uninitialized, which means
1243                  * nothing other than standard metadata in use.
1244                  */
1245                 return;
1246         } else if (blk < ext2fs_blocks_count(rfs->old_fs->super) &&
1247                    ext2fs_test_block_bitmap2(rfs->old_fs->block_map, blk) &&
1248                    !ext2fs_test_block_bitmap2(meta_bmap, blk)) {
1249                 ext2fs_mark_block_bitmap2(rfs->move_blocks, blk);
1250                 rfs->needed_blocks++;
1251         }
1252 }
1253
1254
1255 /*
1256  * This routine marks and unmarks reserved blocks in the new block
1257  * bitmap.  It also determines which blocks need to be moved and
1258  * places this information into the move_blocks bitmap.
1259  */
1260 static errcode_t blocks_to_move(ext2_resize_t rfs)
1261 {
1262         unsigned int    j;
1263         int             has_super;
1264         dgrp_t          i, max_groups, g;
1265         blk64_t         blk, group_blk;
1266         blk64_t         old_blocks, new_blocks, group_end, cluster_freed;
1267         blk64_t         new_size;
1268         unsigned int    meta_bg, meta_bg_size;
1269         errcode_t       retval;
1270         ext2_filsys     fs, old_fs;
1271         ext2fs_block_bitmap     meta_bmap, new_meta_bmap = NULL;
1272         int             flex_bg;
1273
1274         fs = rfs->new_fs;
1275         old_fs = rfs->old_fs;
1276         if (ext2fs_blocks_count(old_fs->super) > ext2fs_blocks_count(fs->super))
1277                 fs = rfs->old_fs;
1278
1279         retval = ext2fs_allocate_block_bitmap(fs, _("blocks to be moved"),
1280                                               &rfs->move_blocks);
1281         if (retval)
1282                 return retval;
1283
1284         retval = ext2fs_allocate_block_bitmap(fs, _("meta-data blocks"),
1285                                               &meta_bmap);
1286         if (retval)
1287                 return retval;
1288
1289         retval = mark_table_blocks(old_fs, meta_bmap);
1290         if (retval)
1291                 return retval;
1292
1293         fs = rfs->new_fs;
1294
1295         /*
1296          * If we're shrinking the filesystem, we need to move any
1297          * group's metadata blocks (either allocation bitmaps or the
1298          * inode table) which are beyond the end of the new
1299          * filesystem.
1300          */
1301         new_size = ext2fs_blocks_count(fs->super);
1302         if (new_size < ext2fs_blocks_count(old_fs->super)) {
1303                 for (g = 0; g < fs->group_desc_count; g++) {
1304                         int realloc = 0;
1305                         /*
1306                          * ext2fs_allocate_group_table will re-allocate any
1307                          * metadata blocks whose location is set to zero.
1308                          */
1309                         if (ext2fs_block_bitmap_loc(fs, g) >= new_size) {
1310                                 ext2fs_block_bitmap_loc_set(fs, g, 0);
1311                                 realloc = 1;
1312                         }
1313                         if (ext2fs_inode_bitmap_loc(fs, g) >= new_size) {
1314                                 ext2fs_inode_bitmap_loc_set(fs, g, 0);
1315                                 realloc = 1;
1316                         }
1317                         if ((ext2fs_inode_table_loc(fs, g) +
1318                              fs->inode_blocks_per_group) > new_size) {
1319                                 ext2fs_inode_table_loc_set(fs, g, 0);
1320                                 realloc = 1;
1321                         }
1322
1323                         if (realloc) {
1324                                 retval = ext2fs_allocate_group_table(fs, g, 0);
1325                                 if (retval)
1326                                         return retval;
1327                         }
1328                 }
1329         }
1330
1331         /*
1332          * If we're shrinking the filesystem, we need to move all of
1333          * the blocks that don't fit any more
1334          */
1335         for (blk = ext2fs_blocks_count(fs->super);
1336              blk < ext2fs_blocks_count(old_fs->super); blk++) {
1337                 g = ext2fs_group_of_blk2(fs, blk);
1338                 if (ext2fs_has_group_desc_csum(fs) &&
1339                     ext2fs_bg_flags_test(old_fs, g, EXT2_BG_BLOCK_UNINIT)) {
1340                         /*
1341                          * The block bitmap is uninitialized, so skip
1342                          * to the next block group.
1343                          */
1344                         blk = ext2fs_group_first_block2(fs, g+1) - 1;
1345                         continue;
1346                 }
1347                 if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
1348                     !ext2fs_test_block_bitmap2(meta_bmap, blk)) {
1349                         ext2fs_mark_block_bitmap2(rfs->move_blocks, blk);
1350                         rfs->needed_blocks++;
1351                 }
1352                 ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
1353         }
1354
1355         if (ext2fs_has_feature_meta_bg(old_fs->super))
1356                 old_blocks = old_fs->super->s_first_meta_bg;
1357         else
1358                 old_blocks = old_fs->desc_blocks +
1359                         old_fs->super->s_reserved_gdt_blocks;
1360         if (ext2fs_has_feature_meta_bg(fs->super))
1361                 new_blocks = fs->super->s_first_meta_bg;
1362         else
1363                 new_blocks = fs->desc_blocks + fs->super->s_reserved_gdt_blocks;
1364
1365         retval = reserve_sparse_super2_last_group(rfs, meta_bmap);
1366         if (retval)
1367                 goto errout;
1368
1369         if (EXT2_DESC_SIZE(rfs->old_fs->super) ==
1370             EXT2_DESC_SIZE(rfs->new_fs->super) &&
1371             old_blocks == new_blocks) {
1372                 retval = 0;
1373                 goto errout;
1374         }
1375
1376         max_groups = fs->group_desc_count;
1377         if (max_groups > old_fs->group_desc_count)
1378                 max_groups = old_fs->group_desc_count;
1379         group_blk = old_fs->super->s_first_data_block;
1380         /*
1381          * If we're reducing the number of descriptor blocks, this
1382          * makes life easy.  :-)   We just have to mark some extra
1383          * blocks as free.
1384          */
1385         if (old_blocks > new_blocks) {
1386                 if (EXT2FS_CLUSTER_RATIO(fs) > 1) {
1387                         retval = ext2fs_allocate_block_bitmap(fs,
1388                                                         _("new meta blocks"),
1389                                                         &new_meta_bmap);
1390                         if (retval)
1391                                 goto errout;
1392
1393                         retval = mark_table_blocks(fs, new_meta_bmap);
1394                         if (retval)
1395                                 goto errout;
1396                 }
1397
1398                 for (i = 0; i < max_groups; i++) {
1399                         if (!ext2fs_bg_has_super(old_fs, i)) {
1400                                 group_blk += fs->super->s_blocks_per_group;
1401                                 continue;
1402                         }
1403                         group_end = group_blk + 1 + old_blocks;
1404                         for (blk = group_blk + 1 + new_blocks;
1405                              blk < group_end;) {
1406                                 if (new_meta_bmap == NULL ||
1407                                     !ext2fs_test_block_bitmap2(new_meta_bmap,
1408                                                                blk)) {
1409                                         cluster_freed =
1410                                                 EXT2FS_CLUSTER_RATIO(fs) -
1411                                                 (blk &
1412                                                  EXT2FS_CLUSTER_MASK(fs));
1413                                         if (cluster_freed > group_end - blk)
1414                                                 cluster_freed = group_end - blk;
1415                                         ext2fs_block_alloc_stats2(fs, blk, -1);
1416                                         blk += EXT2FS_CLUSTER_RATIO(fs);
1417                                         rfs->needed_blocks -= cluster_freed;
1418                                         continue;
1419                                 }
1420                                 rfs->needed_blocks--;
1421                                 blk++;
1422                         }
1423                         group_blk += fs->super->s_blocks_per_group;
1424                 }
1425                 retval = 0;
1426                 goto errout;
1427         }
1428         /*
1429          * If we're increasing the number of descriptor blocks, life
1430          * gets interesting....
1431          */
1432         meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
1433         flex_bg = ext2fs_has_feature_flex_bg(fs->super);
1434         /* first reserve all of the existing fs meta blocks */
1435         for (i = 0; i < max_groups; i++) {
1436                 has_super = ext2fs_bg_has_super(fs, i);
1437                 if (has_super)
1438                         mark_fs_metablock(rfs, meta_bmap, i, group_blk);
1439
1440                 meta_bg = i / meta_bg_size;
1441                 if (!ext2fs_has_feature_meta_bg(fs->super) ||
1442                     (meta_bg < fs->super->s_first_meta_bg)) {
1443                         if (has_super) {
1444                                 for (blk = group_blk+1;
1445                                      blk < group_blk + 1 + new_blocks; blk++)
1446                                         mark_fs_metablock(rfs, meta_bmap,
1447                                                           i, blk);
1448                         }
1449                 } else {
1450                         if (has_super)
1451                                 has_super = 1;
1452                         if (((i % meta_bg_size) == 0) ||
1453                             ((i % meta_bg_size) == 1) ||
1454                             ((i % meta_bg_size) == (meta_bg_size-1)))
1455                                 mark_fs_metablock(rfs, meta_bmap, i,
1456                                                   group_blk + has_super);
1457                 }
1458
1459                 /*
1460                  * Reserve the existing meta blocks that we know
1461                  * aren't to be moved.
1462                  *
1463                  * For flex_bg file systems, in order to avoid
1464                  * overwriting fs metadata (especially inode table
1465                  * blocks) belonging to a different block group when
1466                  * we are relocating the inode tables, we need to
1467                  * reserve all existing fs metadata blocks.
1468                  */
1469                 if (ext2fs_block_bitmap_loc(fs, i))
1470                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
1471                                  ext2fs_block_bitmap_loc(fs, i));
1472                 else if (flex_bg && i < old_fs->group_desc_count)
1473                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
1474                                  ext2fs_block_bitmap_loc(old_fs, i));
1475
1476                 if (ext2fs_inode_bitmap_loc(fs, i))
1477                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
1478                                  ext2fs_inode_bitmap_loc(fs, i));
1479                 else if (flex_bg && i < old_fs->group_desc_count)
1480                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
1481                                  ext2fs_inode_bitmap_loc(old_fs, i));
1482
1483                 if (ext2fs_inode_table_loc(fs, i))
1484                         ext2fs_mark_block_bitmap_range2(rfs->reserve_blocks,
1485                                         ext2fs_inode_table_loc(fs, i),
1486                                         fs->inode_blocks_per_group);
1487                 else if (flex_bg && i < old_fs->group_desc_count)
1488                         ext2fs_mark_block_bitmap_range2(rfs->reserve_blocks,
1489                                         ext2fs_inode_table_loc(old_fs, i),
1490                                         old_fs->inode_blocks_per_group);
1491
1492                 group_blk += rfs->new_fs->super->s_blocks_per_group;
1493         }
1494
1495         /* Allocate the missing data structures */
1496         for (i = 0; i < max_groups; i++) {
1497                 if (ext2fs_inode_table_loc(fs, i) &&
1498                     ext2fs_inode_bitmap_loc(fs, i) &&
1499                     ext2fs_block_bitmap_loc(fs, i))
1500                         continue;
1501
1502                 retval = ext2fs_allocate_group_table(fs, i,
1503                                                      rfs->reserve_blocks);
1504                 if (retval)
1505                         goto errout;
1506
1507                 /*
1508                  * For those structures that have changed, we need to
1509                  * do bookkeeping.
1510                  */
1511                 if (ext2fs_block_bitmap_loc(old_fs, i) !=
1512                     (blk = ext2fs_block_bitmap_loc(fs, i))) {
1513                         ext2fs_block_alloc_stats2(fs, blk, +1);
1514                         if (blk < ext2fs_blocks_count(old_fs->super) &&
1515                             ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
1516                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
1517                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
1518                                                          blk);
1519                 }
1520                 if (ext2fs_inode_bitmap_loc(old_fs, i) !=
1521                     (blk = ext2fs_inode_bitmap_loc(fs, i))) {
1522                         ext2fs_block_alloc_stats2(fs, blk, +1);
1523                         if (blk < ext2fs_blocks_count(old_fs->super) &&
1524                             ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
1525                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
1526                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
1527                                                          blk);
1528                 }
1529
1530                 /*
1531                  * The inode table, if we need to relocate it, is
1532                  * handled specially.  We have to reserve the blocks
1533                  * for both the old and the new inode table, since we
1534                  * can't have the inode table be destroyed during the
1535                  * block relocation phase.
1536                  */
1537                 if (ext2fs_inode_table_loc(fs, i) == ext2fs_inode_table_loc(old_fs, i))
1538                         continue;       /* inode table not moved */
1539
1540                 rfs->needed_blocks += fs->inode_blocks_per_group;
1541
1542                 /*
1543                  * Mark the new inode table as in use in the new block
1544                  * allocation bitmap, and move any blocks that might
1545                  * be necessary.
1546                  */
1547                 for (blk = ext2fs_inode_table_loc(fs, i), j=0;
1548                      j < fs->inode_blocks_per_group ; j++, blk++) {
1549                         ext2fs_block_alloc_stats2(fs, blk, +1);
1550                         if (blk < ext2fs_blocks_count(old_fs->super) &&
1551                             ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
1552                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
1553                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
1554                                                          blk);
1555                 }
1556
1557                 /*
1558                  * Make sure the old inode table is reserved in the
1559                  * block reservation bitmap.
1560                  */
1561                 for (blk = ext2fs_inode_table_loc(rfs->old_fs, i), j=0;
1562                      j < fs->inode_blocks_per_group ; j++, blk++)
1563                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
1564         }
1565         retval = 0;
1566
1567 errout:
1568         if (new_meta_bmap)
1569                 ext2fs_free_block_bitmap(new_meta_bmap);
1570         if (meta_bmap)
1571                 ext2fs_free_block_bitmap(meta_bmap);
1572
1573         return retval;
1574 }
1575
1576 /*
1577  * This helper function tries to allocate a new block.  We try to
1578  * avoid hitting the original group descriptor blocks at least at
1579  * first, since we want to make it possible to recover from a badly
1580  * aborted resize operation as much as possible.
1581  *
1582  * In the future, I may further modify this routine to balance out
1583  * where we get the new blocks across the various block groups.
1584  * Ideally we would allocate blocks that corresponded with the block
1585  * group of the containing inode, and keep contiguous blocks
1586  * together.  However, this very difficult to do efficiently, since we
1587  * don't have the necessary information up front.
1588  */
1589
1590 #define AVOID_OLD       1
1591 #define DESPERATION     2
1592
1593 static void init_block_alloc(ext2_resize_t rfs)
1594 {
1595         rfs->alloc_state = AVOID_OLD;
1596         rfs->new_blk = rfs->new_fs->super->s_first_data_block;
1597 #if 0
1598         /* HACK for testing */
1599         if (ext2fs_blocks_count(rfs->new_fs->super) >
1600             ext2fs_blocks_count(rfs->old_fs->super))
1601                 rfs->new_blk = ext2fs_blocks_count(rfs->old_fs->super);
1602 #endif
1603 }
1604
1605 static blk64_t get_new_block(ext2_resize_t rfs)
1606 {
1607         ext2_filsys     fs = rfs->new_fs;
1608
1609         while (1) {
1610                 if (rfs->new_blk >= ext2fs_blocks_count(fs->super)) {
1611                         if (rfs->alloc_state == DESPERATION)
1612                                 return 0;
1613
1614 #ifdef RESIZE2FS_DEBUG
1615                         if (rfs->flags & RESIZE_DEBUG_BMOVE)
1616                                 printf("Going into desperation mode "
1617                                        "for block allocations\n");
1618 #endif
1619                         rfs->alloc_state = DESPERATION;
1620                         rfs->new_blk = fs->super->s_first_data_block;
1621                         continue;
1622                 }
1623                 if (ext2fs_test_block_bitmap2(fs->block_map, rfs->new_blk) ||
1624                     ext2fs_test_block_bitmap2(rfs->reserve_blocks,
1625                                              rfs->new_blk) ||
1626                     ((rfs->alloc_state == AVOID_OLD) &&
1627                      (rfs->new_blk < ext2fs_blocks_count(rfs->old_fs->super)) &&
1628                      ext2fs_test_block_bitmap2(rfs->old_fs->block_map,
1629                                               rfs->new_blk))) {
1630                         rfs->new_blk++;
1631                         continue;
1632                 }
1633                 return rfs->new_blk;
1634         }
1635 }
1636
1637 static errcode_t resize2fs_get_alloc_block(ext2_filsys fs,
1638                                            blk64_t goal EXT2FS_ATTR((unused)),
1639                                            blk64_t *ret)
1640 {
1641         ext2_resize_t rfs = (ext2_resize_t) fs->priv_data;
1642         blk64_t blk;
1643         int group;
1644
1645         blk = get_new_block(rfs);
1646         if (!blk)
1647                 return ENOSPC;
1648
1649 #ifdef RESIZE2FS_DEBUG
1650         if (rfs->flags & 0xF)
1651                 printf("get_alloc_block allocating %llu\n",
1652                        (unsigned long long) blk);
1653 #endif
1654
1655         ext2fs_mark_block_bitmap2(rfs->old_fs->block_map, blk);
1656         ext2fs_mark_block_bitmap2(rfs->new_fs->block_map, blk);
1657
1658         group = ext2fs_group_of_blk2(rfs->old_fs, blk);
1659         ext2fs_clear_block_uninit(rfs->old_fs, group);
1660         group = ext2fs_group_of_blk2(rfs->new_fs, blk);
1661         ext2fs_clear_block_uninit(rfs->new_fs, group);
1662
1663         *ret = (blk64_t) blk;
1664         return 0;
1665 }
1666
1667 static errcode_t block_mover(ext2_resize_t rfs)
1668 {
1669         blk64_t                 blk, old_blk, new_blk;
1670         ext2_filsys             fs = rfs->new_fs;
1671         ext2_filsys             old_fs = rfs->old_fs;
1672         errcode_t               retval;
1673         __u64                   c, size;
1674         int                     to_move, moved;
1675         ext2_badblocks_list     badblock_list = 0;
1676         int                     bb_modified = 0;
1677
1678         fs->get_alloc_block = resize2fs_get_alloc_block;
1679         old_fs->get_alloc_block = resize2fs_get_alloc_block;
1680
1681         retval = ext2fs_read_bb_inode(old_fs, &badblock_list);
1682         if (retval)
1683                 return retval;
1684
1685         new_blk = fs->super->s_first_data_block;
1686         if (!rfs->itable_buf) {
1687                 retval = ext2fs_get_array(fs->blocksize,
1688                                         fs->inode_blocks_per_group,
1689                                         &rfs->itable_buf);
1690                 if (retval)
1691                         return retval;
1692         }
1693         retval = ext2fs_create_extent_table(&rfs->bmap, 0);
1694         if (retval)
1695                 return retval;
1696
1697         /*
1698          * The first step is to figure out where all of the blocks
1699          * will go.
1700          */
1701         to_move = moved = 0;
1702         init_block_alloc(rfs);
1703         for (blk = B2C(old_fs->super->s_first_data_block);
1704              blk < ext2fs_blocks_count(old_fs->super);
1705              blk += EXT2FS_CLUSTER_RATIO(fs)) {
1706                 if (!ext2fs_test_block_bitmap2(old_fs->block_map, blk))
1707                         continue;
1708                 if (!ext2fs_test_block_bitmap2(rfs->move_blocks, blk))
1709                         continue;
1710                 if (ext2fs_badblocks_list_test(badblock_list, blk)) {
1711                         ext2fs_badblocks_list_del(badblock_list, blk);
1712                         bb_modified++;
1713                         continue;
1714                 }
1715
1716                 new_blk = get_new_block(rfs);
1717                 if (!new_blk) {
1718                         retval = ENOSPC;
1719                         goto errout;
1720                 }
1721                 ext2fs_block_alloc_stats2(fs, new_blk, +1);
1722                 ext2fs_add_extent_entry(rfs->bmap, B2C(blk), B2C(new_blk));
1723                 to_move++;
1724         }
1725
1726         if (to_move == 0) {
1727                 if (rfs->bmap) {
1728                         ext2fs_free_extent_table(rfs->bmap);
1729                         rfs->bmap = 0;
1730                 }
1731                 retval = 0;
1732                 goto errout;
1733         }
1734
1735         /*
1736          * Step two is to actually move the blocks
1737          */
1738         retval =  ext2fs_iterate_extent(rfs->bmap, 0, 0, 0);
1739         if (retval) goto errout;
1740
1741         if (rfs->progress) {
1742                 retval = (rfs->progress)(rfs, E2_RSZ_BLOCK_RELOC_PASS,
1743                                          0, to_move);
1744                 if (retval)
1745                         goto errout;
1746         }
1747         while (1) {
1748                 retval = ext2fs_iterate_extent(rfs->bmap, &old_blk, &new_blk, &size);
1749                 if (retval) goto errout;
1750                 if (!size)
1751                         break;
1752                 old_blk = C2B(old_blk);
1753                 new_blk = C2B(new_blk);
1754                 size = C2B(size);
1755 #ifdef RESIZE2FS_DEBUG
1756                 if (rfs->flags & RESIZE_DEBUG_BMOVE)
1757                         printf("Moving %llu blocks %llu->%llu\n",
1758                                (unsigned long long) size,
1759                                (unsigned long long) old_blk,
1760                                (unsigned long long) new_blk);
1761 #endif
1762                 do {
1763                         c = size;
1764                         if (c > fs->inode_blocks_per_group)
1765                                 c = fs->inode_blocks_per_group;
1766                         retval = io_channel_read_blk64(fs->io, old_blk, c,
1767                                                        rfs->itable_buf);
1768                         if (retval) goto errout;
1769                         retval = io_channel_write_blk64(fs->io, new_blk, c,
1770                                                         rfs->itable_buf);
1771                         if (retval) goto errout;
1772                         size -= c;
1773                         new_blk += c;
1774                         old_blk += c;
1775                         moved += c;
1776                         if (rfs->progress) {
1777                                 io_channel_flush(fs->io);
1778                                 retval = (rfs->progress)(rfs,
1779                                                 E2_RSZ_BLOCK_RELOC_PASS,
1780                                                 moved, to_move);
1781                                 if (retval)
1782                                         goto errout;
1783                         }
1784                 } while (size > 0);
1785                 io_channel_flush(fs->io);
1786         }
1787
1788 errout:
1789         if (badblock_list) {
1790                 if (!retval && bb_modified)
1791                         retval = ext2fs_update_bb_inode(old_fs,
1792                                                         badblock_list);
1793                 ext2fs_badblocks_list_free(badblock_list);
1794         }
1795         return retval;
1796 }
1797
1798
1799 /* --------------------------------------------------------------------
1800  *
1801  * Resize processing, phase 3
1802  *
1803  * --------------------------------------------------------------------
1804  */
1805
1806
1807 /*
1808  * The extent translation table is stored in clusters so we need to
1809  * take special care when mapping a source block number to its
1810  * destination block number.
1811  */
1812 static __u64 extent_translate(ext2_filsys fs, ext2_extent extent, __u64 old_loc)
1813 {
1814         __u64 new_block = C2B(ext2fs_extent_translate(extent, B2C(old_loc)));
1815
1816         if (new_block != 0)
1817                 new_block += old_loc & (EXT2FS_CLUSTER_RATIO(fs) - 1);
1818         return new_block;
1819 }
1820
1821 struct process_block_struct {
1822         ext2_resize_t           rfs;
1823         ext2_ino_t              ino;
1824         ext2_ino_t              old_ino;
1825         struct ext2_inode *     inode;
1826         errcode_t               error;
1827         int                     is_dir;
1828         int                     changed;
1829         int                     has_extents;
1830 };
1831
1832 static int process_block(ext2_filsys fs, blk64_t        *block_nr,
1833                          e2_blkcnt_t blockcnt,
1834                          blk64_t ref_block EXT2FS_ATTR((unused)),
1835                          int ref_offset EXT2FS_ATTR((unused)), void *priv_data)
1836 {
1837         struct process_block_struct *pb;
1838         errcode_t       retval;
1839         blk64_t         block, new_block;
1840         int             ret = 0;
1841
1842         pb = (struct process_block_struct *) priv_data;
1843         block = *block_nr;
1844         if (pb->rfs->bmap) {
1845                 new_block = extent_translate(fs, pb->rfs->bmap, block);
1846                 if (new_block) {
1847                         *block_nr = new_block;
1848                         ret |= BLOCK_CHANGED;
1849                         pb->changed = 1;
1850 #ifdef RESIZE2FS_DEBUG
1851                         if (pb->rfs->flags & RESIZE_DEBUG_BMOVE)
1852                                 printf("ino=%u, blockcnt=%lld, %llu->%llu\n",
1853                                        pb->old_ino, (long long) blockcnt,
1854                                        (unsigned long long) block,
1855                                        (unsigned long long) new_block);
1856 #endif
1857                         block = new_block;
1858                 }
1859         }
1860
1861         if (pb->is_dir) {
1862                 retval = ext2fs_add_dir_block2(fs->dblist, pb->ino,
1863                                                block, (int) blockcnt);
1864                 if (retval) {
1865                         pb->error = retval;
1866                         ret |= BLOCK_ABORT;
1867                 }
1868         }
1869         return ret;
1870 }
1871
1872 /*
1873  * Progress callback
1874  */
1875 static errcode_t progress_callback(ext2_filsys fs,
1876                                    ext2_inode_scan scan EXT2FS_ATTR((unused)),
1877                                    dgrp_t group, void * priv_data)
1878 {
1879         ext2_resize_t rfs = (ext2_resize_t) priv_data;
1880         errcode_t               retval;
1881
1882         /*
1883          * This check is to protect against old ext2 libraries.  It
1884          * shouldn't be needed against new libraries.
1885          */
1886         if ((group+1) == 0)
1887                 return 0;
1888
1889         if (rfs->progress) {
1890                 io_channel_flush(fs->io);
1891                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
1892                                          group+1, fs->group_desc_count);
1893                 if (retval)
1894                         return retval;
1895         }
1896
1897         return 0;
1898 }
1899
1900 static errcode_t migrate_ea_block(ext2_resize_t rfs, ext2_ino_t ino,
1901                                   struct ext2_inode *inode, int *changed)
1902 {
1903         char *buf = NULL;
1904         blk64_t new_block;
1905         errcode_t err = 0;
1906
1907         /* No EA block or no remapping?  Quit early. */
1908         if (ext2fs_file_acl_block(rfs->old_fs, inode) == 0 || !rfs->bmap)
1909                 return 0;
1910         new_block = extent_translate(rfs->old_fs, rfs->bmap,
1911                 ext2fs_file_acl_block(rfs->old_fs, inode));
1912         if (new_block == 0)
1913                 return 0;
1914
1915         /* Set the new ACL block */
1916         ext2fs_file_acl_block_set(rfs->old_fs, inode, new_block);
1917
1918         /* Update checksum */
1919         if (ext2fs_has_feature_metadata_csum(rfs->new_fs->super)) {
1920                 err = ext2fs_get_mem(rfs->old_fs->blocksize, &buf);
1921                 if (err)
1922                         return err;
1923                 rfs->old_fs->flags |= EXT2_FLAG_IGNORE_CSUM_ERRORS;
1924                 err = ext2fs_read_ext_attr3(rfs->old_fs, new_block, buf, ino);
1925                 rfs->old_fs->flags &= ~EXT2_FLAG_IGNORE_CSUM_ERRORS;
1926                 if (err)
1927                         goto out;
1928                 err = ext2fs_write_ext_attr3(rfs->old_fs, new_block, buf, ino);
1929                 if (err)
1930                         goto out;
1931         }
1932         *changed = 1;
1933
1934 out:
1935         ext2fs_free_mem(&buf);
1936         return err;
1937 }
1938
1939 static void quiet_com_err_proc(const char *whoami EXT2FS_ATTR((unused)),
1940                                errcode_t code EXT2FS_ATTR((unused)),
1941                                const char *fmt EXT2FS_ATTR((unused)),
1942                                va_list args EXT2FS_ATTR((unused)))
1943 {
1944 }
1945
1946 static int fix_ea_entries(ext2_extent imap, struct ext2_ext_attr_entry *entry,
1947                           struct ext2_ext_attr_entry *end, ext2_ino_t last_ino)
1948 {
1949         int modified = 0;
1950         ext2_ino_t new_ino;
1951
1952         while (entry < end && !EXT2_EXT_IS_LAST_ENTRY(entry)) {
1953                 if (entry->e_value_inum > last_ino) {
1954                         new_ino = ext2fs_extent_translate(imap,
1955                                                           entry->e_value_inum);
1956                         entry->e_value_inum = new_ino;
1957                         modified = 1;
1958                 }
1959                 entry = EXT2_EXT_ATTR_NEXT(entry);
1960         }
1961         return modified;
1962 }
1963
1964 static int fix_ea_ibody_entries(ext2_extent imap,
1965                                 struct ext2_inode_large *inode, int inode_size,
1966                                 ext2_ino_t last_ino)
1967 {
1968         struct ext2_ext_attr_entry *start, *end;
1969         __u32 *ea_magic;
1970
1971         if (inode->i_extra_isize == 0)
1972                 return 0;
1973
1974         ea_magic = (__u32 *)((char *)inode + EXT2_GOOD_OLD_INODE_SIZE +
1975                                 inode->i_extra_isize);
1976         if (*ea_magic != EXT2_EXT_ATTR_MAGIC)
1977                 return 0;
1978
1979         start = (struct ext2_ext_attr_entry *)(ea_magic + 1);
1980         end = (struct ext2_ext_attr_entry *)((char *)inode + inode_size);
1981
1982         return fix_ea_entries(imap, start, end, last_ino);
1983 }
1984
1985 static int fix_ea_block_entries(ext2_extent imap, char *block_buf,
1986                                 unsigned int blocksize, ext2_ino_t last_ino)
1987 {
1988         struct ext2_ext_attr_header *header;
1989         struct ext2_ext_attr_entry *start, *end;
1990
1991         header = (struct ext2_ext_attr_header *)block_buf;
1992         start = (struct ext2_ext_attr_entry *)(header+1);
1993         end = (struct ext2_ext_attr_entry *)(block_buf + blocksize);
1994
1995         return fix_ea_entries(imap, start, end, last_ino);
1996 }
1997
1998 /* A simple LRU cache to check recently processed blocks. */
1999 struct blk_cache {
2000         int cursor;
2001         blk64_t blks[4];
2002 };
2003
2004 #define BLK_IN_CACHE(b,c) ((b) == (c).blks[0] || (b) == (c).blks[1] || \
2005                            (b) == (c).blks[2] || (b) == (c).blks[3])
2006 #define BLK_ADD_CACHE(b,c) {                    \
2007         (c).blks[(c).cursor] = (b);             \
2008         (c).cursor = ((c).cursor + 1) % 4;      \
2009 }
2010
2011 static errcode_t fix_ea_inode_refs(ext2_resize_t rfs, struct ext2_inode *inode,
2012                                    char *block_buf, ext2_ino_t last_ino)
2013 {
2014         ext2_filsys     fs = rfs->new_fs;
2015         ext2_inode_scan scan = NULL;
2016         ext2_ino_t      ino;
2017         int             inode_size = EXT2_INODE_SIZE(fs->super);
2018         blk64_t         blk;
2019         int             modified;
2020         struct blk_cache blk_cache;
2021         struct ext2_ext_attr_header *header;
2022         errcode_t               retval;
2023
2024         memset(&blk_cache, 0, sizeof(blk_cache));
2025
2026         header = (struct ext2_ext_attr_header *)block_buf;
2027
2028         retval = ext2fs_open_inode_scan(fs, 0, &scan);
2029         if (retval)
2030                 goto out;
2031
2032         while (1) {
2033                 retval = ext2fs_get_next_inode_full(scan, &ino, inode,
2034                                                     inode_size);
2035                 if (retval)
2036                         goto out;
2037                 if (!ino)
2038                         break;
2039
2040                 if (inode->i_links_count == 0 && ino != EXT2_RESIZE_INO)
2041                         continue; /* inode not in use */
2042
2043                 if (inode_size != EXT2_GOOD_OLD_INODE_SIZE) {
2044                         modified = fix_ea_ibody_entries(rfs->imap,
2045                                         (struct ext2_inode_large *)inode,
2046                                         inode_size, last_ino);
2047                         if (modified) {
2048                                 retval = ext2fs_write_inode_full(fs, ino, inode,
2049                                                                  inode_size);
2050                                 if (retval)
2051                                         goto out;
2052                         }
2053                 }
2054
2055                 blk = ext2fs_file_acl_block(fs, inode);
2056                 if (blk && !BLK_IN_CACHE(blk, blk_cache)) {
2057                         retval = ext2fs_read_ext_attr3(fs, blk, block_buf, ino);
2058                         if (retval)
2059                                 goto out;
2060
2061                         modified = fix_ea_block_entries(rfs->imap, block_buf,
2062                                                         fs->blocksize,
2063                                                         last_ino);
2064                         if (modified) {
2065                                 retval = ext2fs_write_ext_attr3(fs, blk,
2066                                                                 block_buf, ino);
2067                                 if (retval)
2068                                         goto out;
2069                                 /*
2070                                  * If refcount is greater than 1, we might see
2071                                  * the same block referenced by other inodes
2072                                  * later.
2073                                  */
2074                                 if (header->h_refcount > 1)
2075                                         BLK_ADD_CACHE(blk, blk_cache);
2076                         }
2077                 }
2078         }
2079         retval = 0;
2080 out:
2081         if (scan)
2082                 ext2fs_close_inode_scan(scan);
2083         return retval;
2084
2085 }
2086 static errcode_t inode_scan_and_fix(ext2_resize_t rfs)
2087 {
2088         struct process_block_struct     pb;
2089         ext2_ino_t              ino, new_inode;
2090         struct ext2_inode       *inode = NULL;
2091         ext2_inode_scan         scan = NULL;
2092         errcode_t               retval;
2093         char                    *block_buf = 0;
2094         ext2_ino_t              start_to_move;
2095         int                     inode_size;
2096         int                     update_ea_inode_refs = 0;
2097
2098         if ((rfs->old_fs->group_desc_count <=
2099              rfs->new_fs->group_desc_count) &&
2100             !rfs->bmap)
2101                 return 0;
2102
2103         set_com_err_hook(quiet_com_err_proc);
2104
2105         retval = ext2fs_open_inode_scan(rfs->old_fs, 0, &scan);
2106         if (retval) goto errout;
2107
2108         retval = ext2fs_init_dblist(rfs->old_fs, 0);
2109         if (retval) goto errout;
2110         retval = ext2fs_get_array(rfs->old_fs->blocksize, 3, &block_buf);
2111         if (retval) goto errout;
2112
2113         start_to_move = (rfs->new_fs->group_desc_count *
2114                          rfs->new_fs->super->s_inodes_per_group);
2115
2116         if (rfs->progress) {
2117                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
2118                                          0, rfs->old_fs->group_desc_count);
2119                 if (retval)
2120                         goto errout;
2121         }
2122         ext2fs_set_inode_callback(scan, progress_callback, (void *) rfs);
2123         pb.rfs = rfs;
2124         pb.inode = inode;
2125         pb.error = 0;
2126         new_inode = EXT2_FIRST_INODE(rfs->new_fs->super);
2127         inode_size = EXT2_INODE_SIZE(rfs->new_fs->super);
2128         inode = malloc(inode_size);
2129         if (!inode) {
2130                 retval = ENOMEM;
2131                 goto errout;
2132         }
2133         /*
2134          * First, copy all of the inodes that need to be moved
2135          * elsewhere in the inode table
2136          */
2137         while (1) {
2138                 retval = ext2fs_get_next_inode_full(scan, &ino, inode, inode_size);
2139                 if (retval) goto errout;
2140                 if (!ino)
2141                         break;
2142
2143                 if (inode->i_links_count == 0 && ino != EXT2_RESIZE_INO)
2144                         continue; /* inode not in use */
2145
2146                 pb.is_dir = LINUX_S_ISDIR(inode->i_mode);
2147                 pb.changed = 0;
2148
2149                 /* Remap EA block */
2150                 retval = migrate_ea_block(rfs, ino, inode, &pb.changed);
2151                 if (retval)
2152                         goto errout;
2153
2154                 new_inode = ino;
2155                 if (ino <= start_to_move)
2156                         goto remap_blocks; /* Don't need to move inode. */
2157
2158                 /*
2159                  * Find a new inode.  Now that extents and directory blocks
2160                  * are tied to the inode number through the checksum, we must
2161                  * set up the new inode before we start rewriting blocks.
2162                  */
2163                 retval = ext2fs_new_inode(rfs->new_fs, 0, 0, 0, &new_inode);
2164                 if (retval)
2165                         goto errout;
2166
2167                 ext2fs_inode_alloc_stats2(rfs->new_fs, new_inode, +1,
2168                                           pb.is_dir);
2169                 /*
2170                  * i_ctime field in xattr inodes contain a portion of the ref
2171                  * count, do not overwrite.
2172                  */
2173                 if (inode->i_flags & EXT4_EA_INODE_FL)
2174                         update_ea_inode_refs = 1;
2175                 else
2176                         inode->i_ctime = time(0);
2177
2178                 retval = ext2fs_write_inode_full(rfs->old_fs, new_inode,
2179                                                 inode, inode_size);
2180                 if (retval)
2181                         goto errout;
2182                 pb.changed = 0;
2183
2184 #ifdef RESIZE2FS_DEBUG
2185                 if (rfs->flags & RESIZE_DEBUG_INODEMAP)
2186                         printf("Inode moved %u->%u\n", ino, new_inode);
2187 #endif
2188                 if (!rfs->imap) {
2189                         retval = ext2fs_create_extent_table(&rfs->imap, 0);
2190                         if (retval)
2191                                 goto errout;
2192                 }
2193                 ext2fs_add_extent_entry(rfs->imap, ino, new_inode);
2194
2195 remap_blocks:
2196                 if (pb.changed)
2197                         retval = ext2fs_write_inode_full(rfs->old_fs,
2198                                                          new_inode,
2199                                                          inode, inode_size);
2200                 if (retval)
2201                         goto errout;
2202
2203                 /*
2204                  * Update inodes to point to new blocks; schedule directory
2205                  * blocks for inode remapping.  Need to write out dir blocks
2206                  * with new inode numbers if we have metadata_csum enabled.
2207                  */
2208                 rfs->old_fs->flags |= EXT2_FLAG_IGNORE_CSUM_ERRORS;
2209                 if (ext2fs_inode_has_valid_blocks2(rfs->old_fs, inode) &&
2210                     (rfs->bmap || pb.is_dir)) {
2211                         pb.ino = new_inode;
2212                         pb.old_ino = ino;
2213                         pb.has_extents = inode->i_flags & EXT4_EXTENTS_FL;
2214                         retval = ext2fs_block_iterate3(rfs->old_fs,
2215                                                        new_inode, 0, block_buf,
2216                                                        process_block, &pb);
2217                         if (retval)
2218                                 goto errout;
2219                         if (pb.error) {
2220                                 retval = pb.error;
2221                                 goto errout;
2222                         }
2223                 } else if ((inode->i_flags & EXT4_INLINE_DATA_FL) &&
2224                            (rfs->bmap || pb.is_dir)) {
2225                         /* inline data dir; update it too */
2226                         retval = ext2fs_add_dir_block2(rfs->old_fs->dblist,
2227                                                        new_inode, 0, 0);
2228                         if (retval)
2229                                 goto errout;
2230                 }
2231
2232                 /* Fix up extent block checksums with the new inode number */
2233                 if (ext2fs_has_feature_metadata_csum(rfs->old_fs->super) &&
2234                     (inode->i_flags & EXT4_EXTENTS_FL)) {
2235                         retval = ext2fs_fix_extents_checksums(rfs->old_fs,
2236                                                               new_inode, NULL);
2237                         if (retval)
2238                                 goto errout;
2239                 }
2240         }
2241
2242         if (update_ea_inode_refs &&
2243             ext2fs_has_feature_ea_inode(rfs->new_fs->super)) {
2244                 retval = fix_ea_inode_refs(rfs, inode, block_buf,
2245                                            start_to_move);
2246                 if (retval)
2247                         goto errout;
2248         }
2249         io_channel_flush(rfs->old_fs->io);
2250
2251 errout:
2252         reset_com_err_hook();
2253         rfs->old_fs->flags &= ~EXT2_FLAG_IGNORE_CSUM_ERRORS;
2254         if (rfs->bmap) {
2255                 ext2fs_free_extent_table(rfs->bmap);
2256                 rfs->bmap = 0;
2257         }
2258         if (scan)
2259                 ext2fs_close_inode_scan(scan);
2260         if (block_buf)
2261                 ext2fs_free_mem(&block_buf);
2262         free(inode);
2263         return retval;
2264 }
2265
2266 /* --------------------------------------------------------------------
2267  *
2268  * Resize processing, phase 4.
2269  *
2270  * --------------------------------------------------------------------
2271  */
2272
2273 struct istruct {
2274         ext2_resize_t rfs;
2275         errcode_t       err;
2276         unsigned int    max_dirs;
2277         unsigned int    num;
2278 };
2279
2280 static int check_and_change_inodes(ext2_ino_t dir,
2281                                    int entry EXT2FS_ATTR((unused)),
2282                                    struct ext2_dir_entry *dirent, int offset,
2283                                    int  blocksize EXT2FS_ATTR((unused)),
2284                                    char *buf EXT2FS_ATTR((unused)),
2285                                    void *priv_data)
2286 {
2287         struct istruct *is = (struct istruct *) priv_data;
2288         struct ext2_inode       inode;
2289         ext2_ino_t              new_inode;
2290         errcode_t               retval;
2291         int                     ret = 0;
2292
2293         if (is->rfs->progress && offset == 0) {
2294                 io_channel_flush(is->rfs->old_fs->io);
2295                 is->err = (is->rfs->progress)(is->rfs,
2296                                               E2_RSZ_INODE_REF_UPD_PASS,
2297                                               ++is->num, is->max_dirs);
2298                 if (is->err)
2299                         return DIRENT_ABORT;
2300         }
2301
2302         /*
2303          * If we have checksums enabled and the inode wasn't present in the
2304          * old fs, then we must rewrite all dir blocks with new checksums.
2305          */
2306         if (ext2fs_has_feature_metadata_csum(is->rfs->old_fs->super) &&
2307             !ext2fs_test_inode_bitmap2(is->rfs->old_fs->inode_map, dir))
2308                 ret |= DIRENT_CHANGED;
2309
2310         if (!dirent->inode)
2311                 return ret;
2312
2313         new_inode = ext2fs_extent_translate(is->rfs->imap, dirent->inode);
2314
2315         if (!new_inode)
2316                 return ret;
2317 #ifdef RESIZE2FS_DEBUG
2318         if (is->rfs->flags & RESIZE_DEBUG_INODEMAP)
2319                 printf("Inode translate (dir=%u, name=%.*s, %u->%u)\n",
2320                        dir, ext2fs_dirent_name_len(dirent), dirent->name,
2321                        dirent->inode, new_inode);
2322 #endif
2323
2324         dirent->inode = new_inode;
2325
2326         /* Update the directory mtime and ctime */
2327         retval = ext2fs_read_inode(is->rfs->old_fs, dir, &inode);
2328         if (retval == 0) {
2329                 inode.i_mtime = inode.i_ctime = time(0);
2330                 is->err = ext2fs_write_inode(is->rfs->old_fs, dir, &inode);
2331                 if (is->err)
2332                         return ret | DIRENT_ABORT;
2333         }
2334
2335         return ret | DIRENT_CHANGED;
2336 }
2337
2338 static errcode_t inode_ref_fix(ext2_resize_t rfs)
2339 {
2340         errcode_t               retval;
2341         struct istruct          is;
2342
2343         if (!rfs->imap)
2344                 return 0;
2345
2346         /*
2347          * Now, we iterate over all of the directories to update the
2348          * inode references
2349          */
2350         is.num = 0;
2351         is.max_dirs = ext2fs_dblist_count2(rfs->old_fs->dblist);
2352         is.rfs = rfs;
2353         is.err = 0;
2354
2355         if (rfs->progress) {
2356                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS,
2357                                          0, is.max_dirs);
2358                 if (retval)
2359                         goto errout;
2360         }
2361
2362         rfs->old_fs->flags |= EXT2_FLAG_IGNORE_CSUM_ERRORS;
2363         retval = ext2fs_dblist_dir_iterate(rfs->old_fs->dblist,
2364                                            DIRENT_FLAG_INCLUDE_EMPTY, 0,
2365                                            check_and_change_inodes, &is);
2366         rfs->old_fs->flags &= ~EXT2_FLAG_IGNORE_CSUM_ERRORS;
2367         if (retval)
2368                 goto errout;
2369         if (is.err) {
2370                 retval = is.err;
2371                 goto errout;
2372         }
2373
2374         if (rfs->progress && (is.num < is.max_dirs))
2375                 (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS,
2376                                 is.max_dirs, is.max_dirs);
2377
2378 errout:
2379         ext2fs_free_extent_table(rfs->imap);
2380         rfs->imap = 0;
2381         return retval;
2382 }
2383
2384
2385 /* --------------------------------------------------------------------
2386  *
2387  * Resize processing, phase 5.
2388  *
2389  * In this phase we actually move the inode table around, and then
2390  * update the summary statistics.  This is scary, since aborting here
2391  * will potentially scramble the filesystem.  (We are moving the
2392  * inode tables around in place, and so the potential for lost data,
2393  * or at the very least scrambling the mapping between filenames and
2394  * inode numbers is very high in case of a power failure here.)
2395  * --------------------------------------------------------------------
2396  */
2397
2398
2399 /*
2400  * A very scary routine --- this one moves the inode table around!!!
2401  *
2402  * After this you have to use the rfs->new_fs file handle to read and
2403  * write inodes.
2404  */
2405 static errcode_t move_itables(ext2_resize_t rfs)
2406 {
2407         int             n, num, size;
2408         long long       diff;
2409         dgrp_t          i, max_groups;
2410         ext2_filsys     fs = rfs->new_fs;
2411         char            *cp;
2412         blk64_t         old_blk, new_blk, blk, cluster_freed;
2413         errcode_t       retval;
2414         int             to_move, moved;
2415         unsigned int    j;
2416         ext2fs_block_bitmap     new_bmap = NULL;
2417
2418         max_groups = fs->group_desc_count;
2419         if (max_groups > rfs->old_fs->group_desc_count)
2420                 max_groups = rfs->old_fs->group_desc_count;
2421
2422         size = fs->blocksize * fs->inode_blocks_per_group;
2423         if (!rfs->itable_buf) {
2424                 retval = ext2fs_get_mem(size, &rfs->itable_buf);
2425                 if (retval)
2426                         return retval;
2427         }
2428
2429         if (EXT2FS_CLUSTER_RATIO(fs) > 1) {
2430                 retval = ext2fs_allocate_block_bitmap(fs, _("new meta blocks"),
2431                                                       &new_bmap);
2432                 if (retval)
2433                         return retval;
2434
2435                 retval = mark_table_blocks(fs, new_bmap);
2436                 if (retval)
2437                         goto errout;
2438         }
2439
2440         /*
2441          * Figure out how many inode tables we need to move
2442          */
2443         to_move = moved = 0;
2444         for (i=0; i < max_groups; i++)
2445                 if (ext2fs_inode_table_loc(rfs->old_fs, i) !=
2446                     ext2fs_inode_table_loc(fs, i))
2447                         to_move++;
2448
2449         if (to_move == 0) {
2450                 retval = 0;
2451                 goto errout;
2452         }
2453
2454         if (rfs->progress) {
2455                 retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
2456                                        0, to_move);
2457                 if (retval)
2458                         goto errout;
2459         }
2460
2461         rfs->old_fs->flags |= EXT2_FLAG_MASTER_SB_ONLY;
2462
2463         for (i=0; i < max_groups; i++) {
2464                 old_blk = ext2fs_inode_table_loc(rfs->old_fs, i);
2465                 new_blk = ext2fs_inode_table_loc(fs, i);
2466                 diff = new_blk - old_blk;
2467
2468 #ifdef RESIZE2FS_DEBUG
2469                 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
2470                         printf("Itable move group %d block %llu->%llu (diff %lld)\n",
2471                                i, (unsigned long long) old_blk,
2472                                (unsigned long long) new_blk, diff);
2473 #endif
2474
2475                 if (!diff)
2476                         continue;
2477                 if (diff < 0)
2478                         diff = 0;
2479
2480                 retval = io_channel_read_blk64(fs->io, old_blk,
2481                                                fs->inode_blocks_per_group,
2482                                                rfs->itable_buf);
2483                 if (retval)
2484                         goto errout;
2485                 /*
2486                  * The end of the inode table segment often contains
2487                  * all zeros, and we're often only moving the inode
2488                  * table down a block or two.  If so, we can optimize
2489                  * things by not rewriting blocks that we know to be zero
2490                  * already.
2491                  */
2492                 for (cp = rfs->itable_buf+size-1, n=0; n < size; n++, cp--)
2493                         if (*cp)
2494                                 break;
2495                 n = n >> EXT2_BLOCK_SIZE_BITS(fs->super);
2496 #ifdef RESIZE2FS_DEBUG
2497                 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
2498                         printf("%d blocks of zeros...\n", n);
2499 #endif
2500                 num = fs->inode_blocks_per_group;
2501                 if (n > diff)
2502                         num -= n;
2503
2504                 retval = io_channel_write_blk64(fs->io, new_blk,
2505                                                 num, rfs->itable_buf);
2506                 if (retval) {
2507                         io_channel_write_blk64(fs->io, old_blk,
2508                                                num, rfs->itable_buf);
2509                         goto errout;
2510                 }
2511                 if (n > diff) {
2512                         retval = io_channel_write_blk64(fs->io,
2513                               old_blk + fs->inode_blocks_per_group,
2514                               diff, (rfs->itable_buf +
2515                                      (fs->inode_blocks_per_group - diff) *
2516                                      fs->blocksize));
2517                         if (retval)
2518                                 goto errout;
2519                 }
2520
2521                 for (blk = ext2fs_inode_table_loc(rfs->old_fs, i), j=0;
2522                      j < fs->inode_blocks_per_group;) {
2523                         if (new_bmap == NULL ||
2524                             !ext2fs_test_block_bitmap2(new_bmap, blk)) {
2525                                 ext2fs_block_alloc_stats2(fs, blk, -1);
2526                                 cluster_freed = EXT2FS_CLUSTER_RATIO(fs) -
2527                                                 (blk & EXT2FS_CLUSTER_MASK(fs));
2528                                 blk += cluster_freed;
2529                                 j += cluster_freed;
2530                                 continue;
2531                         }
2532                         blk++;
2533                         j++;
2534                 }
2535
2536                 ext2fs_inode_table_loc_set(rfs->old_fs, i, new_blk);
2537                 ext2fs_group_desc_csum_set(rfs->old_fs, i);
2538                 ext2fs_mark_super_dirty(rfs->old_fs);
2539                 ext2fs_flush(rfs->old_fs);
2540
2541                 if (rfs->progress) {
2542                         retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
2543                                                ++moved, to_move);
2544                         if (retval)
2545                                 goto errout;
2546                 }
2547         }
2548         mark_table_blocks(fs, fs->block_map);
2549         ext2fs_flush(fs);
2550 #ifdef RESIZE2FS_DEBUG
2551         if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
2552                 printf("Inode table move finished.\n");
2553 #endif
2554         retval = 0;
2555
2556 errout:
2557         if (new_bmap)
2558                 ext2fs_free_block_bitmap(new_bmap);
2559         return retval;
2560 }
2561
2562 /*
2563  * This function is used when expanding a file system.  It frees the
2564  * superblock and block group descriptor blocks from the block group
2565  * which is no longer the last block group.
2566  */
2567 static errcode_t clear_sparse_super2_last_group(ext2_resize_t rfs)
2568 {
2569         ext2_filsys     fs = rfs->new_fs;
2570         ext2_filsys     old_fs = rfs->old_fs;
2571         errcode_t       retval;
2572         dgrp_t          old_last_bg = rfs->old_fs->group_desc_count - 1;
2573         dgrp_t          last_bg = fs->group_desc_count - 1;
2574         blk64_t         sb, old_desc;
2575         blk_t           num;
2576
2577         if (!ext2fs_has_feature_sparse_super2(fs->super))
2578                 return 0;
2579
2580         if (last_bg <= old_last_bg)
2581                 return 0;
2582
2583         if (fs->super->s_backup_bgs[0] == old_fs->super->s_backup_bgs[0] &&
2584             fs->super->s_backup_bgs[1] == old_fs->super->s_backup_bgs[1])
2585                 return 0;
2586
2587         if (old_fs->super->s_backup_bgs[0] != old_last_bg &&
2588             old_fs->super->s_backup_bgs[1] != old_last_bg)
2589                 return 0;
2590
2591         if (fs->super->s_backup_bgs[0] == old_last_bg ||
2592             fs->super->s_backup_bgs[1] == old_last_bg)
2593                 return 0;
2594
2595         if (old_last_bg == 0)
2596                 return 0;
2597
2598         retval = ext2fs_super_and_bgd_loc2(rfs->old_fs, old_last_bg,
2599                                            &sb, &old_desc, NULL, &num);
2600         if (retval)
2601                 return retval;
2602
2603         if (sb)
2604                 ext2fs_unmark_block_bitmap2(fs->block_map, sb);
2605         if (old_desc)
2606                 ext2fs_unmark_block_bitmap_range2(fs->block_map, old_desc, num);
2607         return 0;
2608 }
2609
2610 /*
2611  * This function is used when shrinking a file system.  We need to
2612  * utilize blocks from what will be the new last block group for the
2613  * backup superblock and block group descriptor blocks.
2614  * Unfortunately, those blocks may be used by other files or fs
2615  * metadata blocks.  We need to mark them as being in use.
2616  */
2617 static errcode_t reserve_sparse_super2_last_group(ext2_resize_t rfs,
2618                                                  ext2fs_block_bitmap meta_bmap)
2619 {
2620         ext2_filsys     fs = rfs->new_fs;
2621         ext2_filsys     old_fs = rfs->old_fs;
2622         errcode_t       retval;
2623         dgrp_t          old_last_bg = rfs->old_fs->group_desc_count - 1;
2624         dgrp_t          last_bg = fs->group_desc_count - 1;
2625         dgrp_t          g;
2626         blk64_t         blk, sb, old_desc;
2627         blk_t           i, num;
2628         int             realloc = 0;
2629
2630         if (!ext2fs_has_feature_sparse_super2(fs->super))
2631                 return 0;
2632
2633         if (last_bg >= old_last_bg)
2634                 return 0;
2635
2636         if (fs->super->s_backup_bgs[0] == old_fs->super->s_backup_bgs[0] &&
2637             fs->super->s_backup_bgs[1] == old_fs->super->s_backup_bgs[1])
2638                 return 0;
2639
2640         if (fs->super->s_backup_bgs[0] != last_bg &&
2641             fs->super->s_backup_bgs[1] != last_bg)
2642                 return 0;
2643
2644         if (old_fs->super->s_backup_bgs[0] == last_bg ||
2645             old_fs->super->s_backup_bgs[1] == last_bg)
2646                 return 0;
2647
2648         retval = ext2fs_super_and_bgd_loc2(rfs->new_fs, last_bg,
2649                                            &sb, &old_desc, NULL, &num);
2650         if (retval)
2651                 return retval;
2652
2653         if (last_bg && !sb) {
2654                 fputs(_("Should never happen!  No sb in last super_sparse bg?\n"),
2655                       stderr);
2656                 exit(1);
2657         }
2658         if (old_desc && old_desc != sb+1) {
2659                 fputs(_("Should never happen!  Unexpected old_desc in "
2660                         "super_sparse bg?\n"),
2661                       stderr);
2662                 exit(1);
2663         }
2664         num = (old_desc) ? num : 1;
2665
2666         /* Reserve the backup blocks */
2667         ext2fs_mark_block_bitmap_range2(fs->block_map, sb, num);
2668
2669         for (g = 0; g < fs->group_desc_count; g++) {
2670                 blk64_t mb;
2671
2672                 mb = ext2fs_block_bitmap_loc(fs, g);
2673                 if ((mb >= sb) && (mb < sb + num)) {
2674                         ext2fs_block_bitmap_loc_set(fs, g, 0);
2675                         realloc = 1;
2676                 }
2677                 mb = ext2fs_inode_bitmap_loc(fs, g);
2678                 if ((mb >= sb) && (mb < sb + num)) {
2679                         ext2fs_inode_bitmap_loc_set(fs, g, 0);
2680                         realloc = 1;
2681                 }
2682                 mb = ext2fs_inode_table_loc(fs, g);
2683                 if ((mb < sb + num) &&
2684                     (sb < mb + fs->inode_blocks_per_group)) {
2685                         ext2fs_inode_table_loc_set(fs, g, 0);
2686                         realloc = 1;
2687                 }
2688                 if (realloc) {
2689                         retval = ext2fs_allocate_group_table(fs, g, 0);
2690                         if (retval)
2691                                 return retval;
2692                 }
2693         }
2694
2695         for (blk = sb, i = 0; i < num; blk++, i++) {
2696                 if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
2697                     !ext2fs_test_block_bitmap2(meta_bmap, blk)) {
2698                         ext2fs_mark_block_bitmap2(rfs->move_blocks, blk);
2699                         rfs->needed_blocks++;
2700                 }
2701                 ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
2702         }
2703         return 0;
2704 }
2705
2706 /*
2707  * Fix the resize inode
2708  */
2709 static errcode_t fix_resize_inode(ext2_filsys fs)
2710 {
2711         struct ext2_inode       inode;
2712         errcode_t               retval;
2713
2714         if (!ext2fs_has_feature_resize_inode(fs->super))
2715                 return 0;
2716
2717         retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode);
2718         if (retval) goto errout;
2719
2720         ext2fs_iblk_set(fs, &inode, 1);
2721
2722         retval = ext2fs_write_inode(fs, EXT2_RESIZE_INO, &inode);
2723         if (retval) goto errout;
2724
2725         if (!inode.i_block[EXT2_DIND_BLOCK]) {
2726                 /*
2727                  * Avoid zeroing out block #0; that's rude.  This
2728                  * should never happen anyway since the filesystem
2729                  * should be fsck'ed and we assume it is consistent.
2730                  */
2731                 fprintf(stderr, "%s",
2732                         _("Should never happen: resize inode corrupt!\n"));
2733                 exit(1);
2734         }
2735
2736         retval = ext2fs_zero_blocks2(fs, inode.i_block[EXT2_DIND_BLOCK], 1,
2737                                      NULL, NULL);
2738         if (retval)
2739                 goto errout;
2740
2741         retval = ext2fs_create_resize_inode(fs);
2742         if (retval)
2743                 goto errout;
2744
2745 errout:
2746         return retval;
2747 }
2748
2749 /*
2750  * Finally, recalculate the summary information
2751  */
2752 static errcode_t resize2fs_calculate_summary_stats(ext2_filsys fs)
2753 {
2754         blk64_t         blk;
2755         ext2_ino_t      ino;
2756         unsigned int    group = 0;
2757         unsigned int    count = 0;
2758         blk64_t         total_blocks_free = 0;
2759         int             total_inodes_free = 0;
2760         int             group_free = 0;
2761         int             uninit = 0;
2762         blk64_t         super_blk, old_desc_blk, new_desc_blk;
2763         int             old_desc_blocks;
2764
2765         /*
2766          * First calculate the block statistics
2767          */
2768         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT);
2769         ext2fs_super_and_bgd_loc2(fs, group, &super_blk, &old_desc_blk,
2770                                   &new_desc_blk, 0);
2771         if (ext2fs_has_feature_meta_bg(fs->super))
2772                 old_desc_blocks = fs->super->s_first_meta_bg;
2773         else
2774                 old_desc_blocks = fs->desc_blocks +
2775                         fs->super->s_reserved_gdt_blocks;
2776         for (blk = B2C(fs->super->s_first_data_block);
2777              blk < ext2fs_blocks_count(fs->super);
2778              blk += EXT2FS_CLUSTER_RATIO(fs)) {
2779                 if ((uninit &&
2780                      !(EQ_CLSTR(blk, super_blk) ||
2781                        ((old_desc_blk && old_desc_blocks &&
2782                          GE_CLSTR(blk, old_desc_blk) &&
2783                          LT_CLSTR(blk, old_desc_blk + old_desc_blocks))) ||
2784                        ((new_desc_blk && EQ_CLSTR(blk, new_desc_blk))) ||
2785                        EQ_CLSTR(blk, ext2fs_block_bitmap_loc(fs, group)) ||
2786                        EQ_CLSTR(blk, ext2fs_inode_bitmap_loc(fs, group)) ||
2787                        ((GE_CLSTR(blk, ext2fs_inode_table_loc(fs, group)) &&
2788                          LT_CLSTR(blk, ext2fs_inode_table_loc(fs, group)
2789                                   + fs->inode_blocks_per_group))))) ||
2790                     (!ext2fs_fast_test_block_bitmap2(fs->block_map, blk))) {
2791                         group_free++;
2792                         total_blocks_free++;
2793                 }
2794                 count++;
2795                 if ((count == fs->super->s_clusters_per_group) ||
2796                     EQ_CLSTR(blk, ext2fs_blocks_count(fs->super)-1)) {
2797                         ext2fs_bg_free_blocks_count_set(fs, group, group_free);
2798                         ext2fs_group_desc_csum_set(fs, group);
2799                         group++;
2800                         if (group >= fs->group_desc_count)
2801                                 break;
2802                         count = 0;
2803                         group_free = 0;
2804                         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT);
2805                         ext2fs_super_and_bgd_loc2(fs, group, &super_blk,
2806                                                   &old_desc_blk,
2807                                                   &new_desc_blk, 0);
2808                         if (ext2fs_has_feature_meta_bg(fs->super))
2809                                 old_desc_blocks = fs->super->s_first_meta_bg;
2810                         else
2811                                 old_desc_blocks = fs->desc_blocks +
2812                                         fs->super->s_reserved_gdt_blocks;
2813                 }
2814         }
2815         total_blocks_free = C2B(total_blocks_free);
2816         ext2fs_free_blocks_count_set(fs->super, total_blocks_free);
2817
2818         /*
2819          * Next, calculate the inode statistics
2820          */
2821         group_free = 0;
2822         count = 0;
2823         group = 0;
2824
2825         /* Protect loop from wrap-around if s_inodes_count maxed */
2826         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT);
2827         for (ino = 1; ino <= fs->super->s_inodes_count && ino > 0; ino++) {
2828                 if (uninit ||
2829                     !ext2fs_fast_test_inode_bitmap2(fs->inode_map, ino)) {
2830                         group_free++;
2831                         total_inodes_free++;
2832                 }
2833                 count++;
2834                 if ((count == fs->super->s_inodes_per_group) ||
2835                     (ino == fs->super->s_inodes_count)) {
2836                         ext2fs_bg_free_inodes_count_set(fs, group, group_free);
2837                         ext2fs_group_desc_csum_set(fs, group);
2838                         group++;
2839                         if (group >= fs->group_desc_count)
2840                                 break;
2841                         count = 0;
2842                         group_free = 0;
2843                         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT);
2844                 }
2845         }
2846         fs->super->s_free_inodes_count = total_inodes_free;
2847         ext2fs_mark_super_dirty(fs);
2848         return 0;
2849 }
2850
2851 /*
2852  *  Journal may have been relocated; update the backup journal blocks
2853  *  in the superblock.
2854  */
2855 static errcode_t fix_sb_journal_backup(ext2_filsys fs)
2856 {
2857         errcode_t         retval;
2858         struct ext2_inode inode;
2859
2860         if (!ext2fs_has_feature_journal(fs->super))
2861                 return 0;
2862
2863         /* External journal? Nothing to do. */
2864         if (fs->super->s_journal_dev && !fs->super->s_journal_inum)
2865                 return 0;
2866
2867         retval = ext2fs_read_inode(fs, fs->super->s_journal_inum, &inode);
2868         if (retval)
2869                 return retval;
2870         memcpy(fs->super->s_jnl_blocks, inode.i_block, EXT2_N_BLOCKS*4);
2871         fs->super->s_jnl_blocks[15] = inode.i_size_high;
2872         fs->super->s_jnl_blocks[16] = inode.i_size;
2873         fs->super->s_jnl_backup_type = EXT3_JNL_BACKUP_BLOCKS;
2874         ext2fs_mark_super_dirty(fs);
2875         return 0;
2876 }
2877
2878 static int calc_group_overhead(ext2_filsys fs, blk64_t grp,
2879                                int old_desc_blocks)
2880 {
2881         blk64_t super_blk, old_desc_blk, new_desc_blk;
2882         int overhead;
2883
2884         /* inode table blocks plus allocation bitmaps */
2885         overhead = fs->inode_blocks_per_group + 2;
2886
2887         ext2fs_super_and_bgd_loc2(fs, grp, &super_blk,
2888                                   &old_desc_blk, &new_desc_blk, 0);
2889         if ((grp == 0) || super_blk)
2890                 overhead++;
2891         if (old_desc_blk)
2892                 overhead += old_desc_blocks;
2893         else if (new_desc_blk)
2894                 overhead++;
2895         return overhead;
2896 }
2897
2898
2899 /*
2900  * calculate the minimum number of blocks the given fs can be resized to
2901  */
2902 blk64_t calculate_minimum_resize_size(ext2_filsys fs, int flags)
2903 {
2904         ext2_ino_t inode_count;
2905         dgrp_t groups, flex_groups;
2906         blk64_t blks_needed, data_blocks;
2907         blk64_t grp, data_needed, last_start;
2908         blk64_t overhead = 0;
2909         int old_desc_blocks;
2910         int flexbg_size = 1 << fs->super->s_log_groups_per_flex;
2911
2912         /*
2913          * first figure out how many group descriptors we need to
2914          * handle the number of inodes we have
2915          */
2916         inode_count = fs->super->s_inodes_count -
2917                 fs->super->s_free_inodes_count;
2918         blks_needed = ext2fs_div_ceil(inode_count,
2919                                       fs->super->s_inodes_per_group) *
2920                 (blk64_t) EXT2_BLOCKS_PER_GROUP(fs->super);
2921         groups = ext2fs_div64_ceil(blks_needed,
2922                                    EXT2_BLOCKS_PER_GROUP(fs->super));
2923 #ifdef RESIZE2FS_DEBUG
2924         if (flags & RESIZE_DEBUG_MIN_CALC)
2925                 printf("fs has %d inodes, %d groups required.\n",
2926                        inode_count, groups);
2927 #endif
2928
2929         /*
2930          * number of old-style block group descriptor blocks
2931          */
2932         if (ext2fs_has_feature_meta_bg(fs->super))
2933                 old_desc_blocks = fs->super->s_first_meta_bg;
2934         else
2935                 old_desc_blocks = fs->desc_blocks +
2936                         fs->super->s_reserved_gdt_blocks;
2937
2938         /* calculate how many blocks are needed for data */
2939         data_needed = ext2fs_blocks_count(fs->super);
2940         for (grp = 0; grp < fs->group_desc_count; grp++) {
2941                 data_needed -= calc_group_overhead(fs, grp, old_desc_blocks);
2942                 data_needed -= ext2fs_bg_free_blocks_count(fs, grp);
2943         }
2944 #ifdef RESIZE2FS_DEBUG
2945         if (flags & RESIZE_DEBUG_MIN_CALC)
2946                 printf("fs requires %llu data blocks.\n",
2947                        (unsigned long long) data_needed);
2948 #endif
2949
2950         /*
2951          * For ext4 we need to allow for up to a flex_bg worth of
2952          * inode tables of slack space so the resize operation can be
2953          * guaranteed to finish.
2954          */
2955         flex_groups = groups;
2956         if (ext2fs_has_feature_flex_bg(fs->super)) {
2957                 dgrp_t remainder = groups & (flexbg_size - 1);
2958
2959                 flex_groups += flexbg_size - remainder;
2960                 if (flex_groups > fs->group_desc_count)
2961                         flex_groups = fs->group_desc_count;
2962         }
2963
2964         /*
2965          * figure out how many data blocks we have given the number of groups
2966          * we need for our inodes
2967          */
2968         data_blocks = EXT2_GROUPS_TO_BLOCKS(fs->super, groups);
2969         last_start = 0;
2970         for (grp = 0; grp < flex_groups; grp++) {
2971                 overhead = calc_group_overhead(fs, grp, old_desc_blocks);
2972
2973                 /*
2974                  * we want to keep track of how much data we can store in
2975                  * the groups leading up to the last group so we can determine
2976                  * how big the last group needs to be
2977                  */
2978                 if (grp < (groups - 1))
2979                         last_start += EXT2_BLOCKS_PER_GROUP(fs->super) -
2980                                 overhead;
2981
2982                 if (data_blocks > overhead)
2983                         data_blocks -= overhead;
2984                 else
2985                         data_blocks = 0;
2986         }
2987 #ifdef RESIZE2FS_DEBUG
2988         if (flags & RESIZE_DEBUG_MIN_CALC)
2989                 printf("With %d group(s), we have %llu blocks available.\n",
2990                        groups, (unsigned long long) data_blocks);
2991 #endif
2992
2993         /*
2994          * if we need more group descriptors in order to accommodate our data
2995          * then we need to add them here
2996          */
2997         blks_needed = data_needed;
2998         while (blks_needed > data_blocks) {
2999                 blk64_t remainder = blks_needed - data_blocks;
3000                 dgrp_t extra_grps;
3001
3002                 /* figure out how many more groups we need for the data */
3003                 extra_grps = ext2fs_div64_ceil(remainder,
3004                                                EXT2_BLOCKS_PER_GROUP(fs->super));
3005
3006                 data_blocks += EXT2_GROUPS_TO_BLOCKS(fs->super, extra_grps);
3007
3008                 /* ok we have to account for the last group */
3009                 overhead = calc_group_overhead(fs, groups-1, old_desc_blocks);
3010                 last_start += EXT2_BLOCKS_PER_GROUP(fs->super) - overhead;
3011
3012                 grp = flex_groups;
3013                 groups += extra_grps;
3014                 if (!ext2fs_has_feature_flex_bg(fs->super))
3015                         flex_groups = groups;
3016                 else if (groups > flex_groups) {
3017                         dgrp_t r = groups & (flexbg_size - 1);
3018
3019                         flex_groups = groups + flexbg_size - r;
3020                         if (flex_groups > fs->group_desc_count)
3021                                 flex_groups = fs->group_desc_count;
3022                 }
3023
3024                 for (; grp < flex_groups; grp++) {
3025                         overhead = calc_group_overhead(fs, grp,
3026                                                        old_desc_blocks);
3027
3028                         /*
3029                          * again, we need to see how much data we cram into
3030                          * all of the groups leading up to the last group
3031                          */
3032                         if (grp < groups - 1)
3033                                 last_start += EXT2_BLOCKS_PER_GROUP(fs->super)
3034                                         - overhead;
3035
3036                         data_blocks -= overhead;
3037                 }
3038
3039 #ifdef RESIZE2FS_DEBUG
3040                 if (flags & RESIZE_DEBUG_MIN_CALC)
3041                         printf("Added %d extra group(s), "
3042                                "blks_needed %llu, data_blocks %llu, "
3043                                "last_start %llu\n", extra_grps,
3044                                (unsigned long long) blks_needed,
3045                                (unsigned long long) data_blocks,
3046                                (unsigned long long) last_start);
3047 #endif
3048         }
3049
3050         /* now for the fun voodoo */
3051         grp = groups - 1;
3052         if (ext2fs_has_feature_flex_bg(fs->super) &&
3053             (grp & ~(flexbg_size - 1)) == 0)
3054                 grp = grp & ~(flexbg_size - 1);
3055         overhead = 0;
3056         for (; grp < flex_groups; grp++)
3057                 overhead += calc_group_overhead(fs, grp, old_desc_blocks);
3058
3059 #ifdef RESIZE2FS_DEBUG
3060         if (flags & RESIZE_DEBUG_MIN_CALC)
3061                 printf("Last group's overhead is %llu\n",
3062                        (unsigned long long) overhead);
3063 #endif
3064
3065         /*
3066          * if this is the case then the last group is going to have data in it
3067          * so we need to adjust the size of the last group accordingly
3068          */
3069         if (last_start < blks_needed) {
3070                 blk64_t remainder = blks_needed - last_start;
3071
3072 #ifdef RESIZE2FS_DEBUG
3073                 if (flags & RESIZE_DEBUG_MIN_CALC)
3074                         printf("Need %llu data blocks in last group\n",
3075                                (unsigned long long) remainder);
3076 #endif
3077                 /*
3078                  * 50 is a magic number that mkfs/resize uses to see if its
3079                  * even worth making/resizing the fs.  basically you need to
3080                  * have at least 50 blocks in addition to the blocks needed
3081                  * for the metadata in the last group
3082                  */
3083                 if (remainder > 50)
3084                         overhead += remainder;
3085                 else
3086                         overhead += 50;
3087         } else
3088                 overhead += 50;
3089
3090         overhead += fs->super->s_first_data_block;
3091 #ifdef RESIZE2FS_DEBUG
3092         if (flags & RESIZE_DEBUG_MIN_CALC)
3093                 printf("Final size of last group is %llu\n",
3094                        (unsigned long long) overhead);
3095 #endif
3096
3097         /* Add extra slack for bigalloc file systems */
3098         if (EXT2FS_CLUSTER_RATIO(fs) > 1)
3099                 overhead += EXT2FS_CLUSTER_RATIO(fs) * 2;
3100
3101         /*
3102          * since our last group doesn't have to be BLOCKS_PER_GROUP
3103          * large, we only do groups-1, and then add the number of
3104          * blocks needed to handle the group descriptor metadata+data
3105          * that we need
3106          */
3107         blks_needed = EXT2_GROUPS_TO_BLOCKS(fs->super, groups - 1);
3108         blks_needed += overhead;
3109
3110         /*
3111          * Make sure blks_needed covers the end of the inode table in
3112          * the last block group.
3113          */
3114         overhead = ext2fs_inode_table_loc(fs, groups-1) +
3115                 fs->inode_blocks_per_group;
3116         if (blks_needed < overhead)
3117                 blks_needed = overhead;
3118
3119 #ifdef RESIZE2FS_DEBUG
3120         if (flags & RESIZE_DEBUG_MIN_CALC)
3121                 printf("Estimated blocks needed: %llu\n",
3122                        (unsigned long long) blks_needed);
3123 #endif
3124
3125         /*
3126          * If at this point we've already added up more "needed" than
3127          * the current size, just return current size as minimum.
3128          */
3129         if (blks_needed >= ext2fs_blocks_count(fs->super))
3130                 return ext2fs_blocks_count(fs->super);
3131         /*
3132          * We need to reserve a few extra blocks if extents are
3133          * enabled, in case we need to grow the extent tree.  The more
3134          * we shrink the file system, the more space we need.
3135          *
3136          * The absolute worst case is every single data block is in
3137          * the part of the file system that needs to be evacuated,
3138          * with each data block needs to be in its own extent, and
3139          * with each inode needing at least one extent block.
3140          */
3141         if (ext2fs_has_feature_extents(fs->super)) {
3142                 blk64_t safe_margin = (ext2fs_blocks_count(fs->super) -
3143                                        blks_needed)/500;
3144                 unsigned int exts_per_blk = (fs->blocksize /
3145                                              sizeof(struct ext3_extent)) - 1;
3146                 blk64_t worst_case = ((data_needed + exts_per_blk - 1) /
3147                                       exts_per_blk);
3148
3149                 if (worst_case < inode_count)
3150                         worst_case = inode_count;
3151
3152                 if (safe_margin > worst_case)
3153                         safe_margin = worst_case;
3154
3155 #ifdef RESIZE2FS_DEBUG
3156                 if (flags & RESIZE_DEBUG_MIN_CALC)
3157                         printf("Extents safety margin: %llu\n",
3158                                (unsigned long long) safe_margin);
3159 #endif
3160                 blks_needed += safe_margin;
3161         }
3162
3163         return blks_needed;
3164 }