resize/resize2fs.c

   1 /*
   2  * resize2fs.c --- ext2 main routine
   3  *
   4  * Copyright (C) 1997, 1998 by Theodore Ts'o and
   5  *      PowerQuest, Inc.
   6  *
   7  * Copyright (C) 1999, 2000 by Theosore Ts'o
   8  *
   9  * %Begin-Header%
  10  * This file may be redistributed under the terms of the GNU Public
  11  * License.
  12  * %End-Header%
  13  */
  14
  15 /*
  16  * Resizing a filesystem consists of the following phases:
  17  *
  18  *      1.  Adjust superblock and write out new parts of the inode
  19  *              table
  20  *      2.  Determine blocks which need to be relocated, and copy the
  21  *              contents of blocks from their old locations to the new ones.
  22  *      3.  Scan the inode table, doing the following:
  23  *              a.  If blocks have been moved, update the block
  24  *                      pointers in the inodes and indirect blocks to
  25  *                      point at the new block locations.
  26  *              b.  If parts of the inode table need to be evacuated,
  27  *                      copy inodes from their old locations to their
  28  *                      new ones.
  29  *              c.  If (b) needs to be done, note which blocks contain
  30  *                      directory information, since we will need to
  31  *                      update the directory information.
  32  *      4.  Update the directory blocks with the new inode locations.
  33  *      5.  Move the inode tables, if necessary.
  34  */
  35
  36 #include "config.h"
  37 #include "resize2fs.h"
  38 #include <time.h>
  39
  40 #ifdef __linux__                        /* Kludge for debugging */
  41 #define RESIZE2FS_DEBUG
  42 #endif
  43
  44 static void fix_uninit_block_bitmaps(ext2_filsys fs);
  45 static errcode_t adjust_superblock(ext2_resize_t rfs, blk64_t new_size);
  46 static errcode_t blocks_to_move(ext2_resize_t rfs);
  47 static errcode_t block_mover(ext2_resize_t rfs);
  48 static errcode_t inode_scan_and_fix(ext2_resize_t rfs);
  49 static errcode_t inode_ref_fix(ext2_resize_t rfs);
  50 static errcode_t move_itables(ext2_resize_t rfs);
  51 static errcode_t fix_resize_inode(ext2_filsys fs);
  52 static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs);
  53 static errcode_t fix_sb_journal_backup(ext2_filsys fs);
  54 static errcode_t mark_table_blocks(ext2_filsys fs,
  55                                    ext2fs_block_bitmap bmap);
  56 static errcode_t clear_sparse_super2_last_group(ext2_resize_t rfs);
  57 static errcode_t reserve_sparse_super2_last_group(ext2_resize_t rfs,
  58                                                  ext2fs_block_bitmap meta_bmap);
  59 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 inline 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 succint... */
  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                        ext2fs_free_blocks_count(rfs->old_fs->super),
 181                        ext2fs_free_blocks_count(rfs->new_fs->super),
 182                        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         init_resource_track(&rtrack, "calculate_summary_stats", fs->io);
 210         retval = ext2fs_calculate_summary_stats(rfs->new_fs);
 211         if (retval)
 212                 goto errout;
 213         print_resource_track(rfs, &rtrack, fs->io);
 214
 215         init_resource_track(&rtrack, "fix_resize_inode", fs->io);
 216         retval = fix_resize_inode(rfs->new_fs);
 217         if (retval)
 218                 goto errout;
 219         print_resource_track(rfs, &rtrack, fs->io);
 220
 221         init_resource_track(&rtrack, "fix_sb_journal_backup", fs->io);
 222         retval = fix_sb_journal_backup(rfs->new_fs);
 223         if (retval)
 224                 goto errout;
 225         print_resource_track(rfs, &rtrack, fs->io);
 226
 227         retval = clear_sparse_super2_last_group(rfs);
 228         if (retval)
 229                 goto errout;
 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 += EXT2_DESC_SIZE(rfs->new_fs->super);
 333                 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_LINUX)
 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 unitialized bitmaps
 582  */
 583 static void fix_uninit_block_bitmaps(ext2_filsys fs)
 584 {
 585         blk64_t         blk, lblk;
 586         dgrp_t          g;
 587         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 < (unsigned int) 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         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;
 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
 707 retry:
 708         fs->group_desc_count = ext2fs_div64_ceil(ext2fs_blocks_count(fs->super) -
 709                                        fs->super->s_first_data_block,
 710                                        EXT2_BLOCKS_PER_GROUP(fs->super));
 711         if (fs->group_desc_count == 0)
 712                 return EXT2_ET_TOOSMALL;
 713         fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count,
 714                                           EXT2_DESC_PER_BLOCK(fs->super));
 715
 716         /*
 717          * Overhead is the number of bookkeeping blocks per group.  It
 718          * includes the superblock backup, the group descriptor
 719          * backups, the inode bitmap, the block bitmap, and the inode
 720          * table.
 721          */
 722         overhead = (int) (2 + fs->inode_blocks_per_group);
 723
 724         if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1))
 725                 overhead += 1 + fs->desc_blocks +
 726                         fs->super->s_reserved_gdt_blocks;
 727
 728         /*
 729          * See if the last group is big enough to support the
 730          * necessary data structures.  If not, we need to get rid of
 731          * it.
 732          */
 733         rem = (ext2fs_blocks_count(fs->super) - fs->super->s_first_data_block) %
 734                 fs->super->s_blocks_per_group;
 735         if ((fs->group_desc_count == 1) && rem && (rem < overhead))
 736                 return EXT2_ET_TOOSMALL;
 737         if ((fs->group_desc_count > 1) && rem && (rem < overhead+50)) {
 738                 ext2fs_blocks_count_set(fs->super,
 739                                         ext2fs_blocks_count(fs->super) - rem);
 740                 goto retry;
 741         }
 742         /*
 743          * Adjust the number of inodes
 744          */
 745         new_inodes =(unsigned long long) fs->super->s_inodes_per_group * fs->group_desc_count;
 746         if (new_inodes > ~0U) {
 747                 fprintf(stderr, _("inodes (%llu) must be less than %u"),
 748                                    new_inodes, ~0U);
 749                 return EXT2_ET_TOO_MANY_INODES;
 750         }
 751         fs->super->s_inodes_count = fs->super->s_inodes_per_group *
 752                 fs->group_desc_count;
 753
 754         /*
 755          * Adjust the number of free blocks
 756          */
 757         blk = ext2fs_blocks_count(old_fs->super);
 758         if (blk > ext2fs_blocks_count(fs->super))
 759                 ext2fs_free_blocks_count_set(fs->super,
 760                         ext2fs_free_blocks_count(fs->super) -
 761                         (blk - ext2fs_blocks_count(fs->super)));
 762         else
 763                 ext2fs_free_blocks_count_set(fs->super,
 764                         ext2fs_free_blocks_count(fs->super) +
 765                         (ext2fs_blocks_count(fs->super) - blk));
 766
 767         /*
 768          * Adjust the number of reserved blocks
 769          */
 770         percent = (ext2fs_r_blocks_count(old_fs->super) * 100.0) /
 771                 ext2fs_blocks_count(old_fs->super);
 772         ext2fs_r_blocks_count_set(fs->super,
 773                                   (percent * ext2fs_blocks_count(fs->super) /
 774                                    100.0));
 775
 776         /*
 777          * Adjust the bitmaps for size
 778          */
 779         retval = ext2fs_resize_inode_bitmap2(fs->super->s_inodes_count,
 780                                             fs->super->s_inodes_count,
 781                                             fs->inode_map);
 782         if (retval) goto errout;
 783
 784         real_end = EXT2_GROUPS_TO_BLOCKS(fs->super, fs->group_desc_count) - 1 +
 785                 fs->super->s_first_data_block;
 786         retval = ext2fs_resize_block_bitmap2(new_size - 1,
 787                                              real_end, fs->block_map);
 788         if (retval) goto errout;
 789
 790         /*
 791          * If we are growing the file system, also grow the size of
 792          * the reserve_blocks bitmap
 793          */
 794         if (reserve_blocks && new_size > ext2fs_blocks_count(old_fs->super)) {
 795                 retval = ext2fs_resize_block_bitmap2(new_size - 1,
 796                                                      real_end, reserve_blocks);
 797                 if (retval) goto errout;
 798         }
 799
 800         /*
 801          * Reallocate the group descriptors as necessary.
 802          */
 803         if (EXT2_DESC_SIZE(old_fs->super) == EXT2_DESC_SIZE(fs->super) &&
 804             old_fs->desc_blocks != fs->desc_blocks) {
 805                 retval = ext2fs_resize_mem(old_fs->desc_blocks *
 806                                            fs->blocksize,
 807                                            fs->desc_blocks * fs->blocksize,
 808                                            &fs->group_desc);
 809                 if (retval)
 810                         goto errout;
 811                 if (fs->desc_blocks > old_fs->desc_blocks)
 812                         memset((char *) fs->group_desc +
 813                                (old_fs->desc_blocks * fs->blocksize), 0,
 814                                (fs->desc_blocks - old_fs->desc_blocks) *
 815                                fs->blocksize);
 816         }
 817
 818         /*
 819          * If the resize_inode feature is set, and we are changing the
 820          * number of descriptor blocks, then adjust
 821          * s_reserved_gdt_blocks if possible to avoid needing to move
 822          * the inode table either now or in the future.
 823          *
 824          * Note: If we're converting to 64bit mode, we did this earlier.
 825          */
 826         if (EXT2_DESC_SIZE(old_fs->super) == EXT2_DESC_SIZE(fs->super))
 827                 adjust_reserved_gdt_blocks(old_fs, fs);
 828
 829         if (ext2fs_has_feature_meta_bg(fs->super) &&
 830             (fs->super->s_first_meta_bg > fs->desc_blocks)) {
 831                 ext2fs_clear_feature_meta_bg(fs->super);
 832                 fs->super->s_first_meta_bg = 0;
 833         }
 834
 835         /*
 836          * Update the location of the backup superblocks if the
 837          * sparse_super2 feature is enabled.
 838          */
 839         if (ext2fs_has_feature_sparse_super2(fs->super)) {
 840                 dgrp_t last_bg = fs->group_desc_count - 1;
 841                 dgrp_t old_last_bg = old_fs->group_desc_count - 1;
 842
 843                 if (last_bg > old_last_bg) {
 844                         if (old_fs->group_desc_count == 1)
 845                                 fs->super->s_backup_bgs[0] = 1;
 846                         if (old_fs->group_desc_count == 1 &&
 847                             fs->super->s_backup_bgs[0])
 848                                 fs->super->s_backup_bgs[0] = last_bg;
 849                         else if (fs->super->s_backup_bgs[1])
 850                                 fs->super->s_backup_bgs[1] = last_bg;
 851                 } else if (last_bg < old_last_bg) {
 852                         if (fs->super->s_backup_bgs[0] > last_bg)
 853                                 fs->super->s_backup_bgs[0] = 0;
 854                         if (fs->super->s_backup_bgs[1] > last_bg)
 855                                 fs->super->s_backup_bgs[1] = 0;
 856                         if (last_bg > 1 &&
 857                             old_fs->super->s_backup_bgs[1] == old_last_bg)
 858                                 fs->super->s_backup_bgs[1] = last_bg;
 859                 }
 860         }
 861
 862         /*
 863          * If we are shrinking the number of block groups, we're done
 864          * and can exit now.
 865          */
 866         if (old_fs->group_desc_count > fs->group_desc_count) {
 867                 /*
 868                  * Check the block groups that we are chopping off
 869                  * and free any blocks associated with their metadata
 870                  */
 871                 retval = free_gdp_blocks(fs, reserve_blocks, old_fs,
 872                                          fs->group_desc_count);
 873                 goto errout;
 874         }
 875
 876         /*
 877          * Fix the count of the last (old) block group
 878          */
 879         old_numblocks = (ext2fs_blocks_count(old_fs->super) -
 880                          old_fs->super->s_first_data_block) %
 881                                  old_fs->super->s_blocks_per_group;
 882         if (!old_numblocks)
 883                 old_numblocks = old_fs->super->s_blocks_per_group;
 884         if (old_fs->group_desc_count == fs->group_desc_count) {
 885                 numblocks = (ext2fs_blocks_count(fs->super) -
 886                              fs->super->s_first_data_block) %
 887                         fs->super->s_blocks_per_group;
 888                 if (!numblocks)
 889                         numblocks = fs->super->s_blocks_per_group;
 890         } else
 891                 numblocks = fs->super->s_blocks_per_group;
 892         i = old_fs->group_desc_count - 1;
 893         ext2fs_bg_free_blocks_count_set(fs, i, ext2fs_bg_free_blocks_count(fs, i) + (numblocks - old_numblocks));
 894         ext2fs_group_desc_csum_set(fs, i);
 895
 896         /*
 897          * If the number of block groups is staying the same, we're
 898          * done and can exit now.  (If the number block groups is
 899          * shrinking, we had exited earlier.)
 900          */
 901         if (old_fs->group_desc_count >= fs->group_desc_count) {
 902                 retval = 0;
 903                 goto errout;
 904         }
 905
 906         /*
 907          * Initialize the new block group descriptors
 908          */
 909         group_block = ext2fs_group_first_block2(fs,
 910                                                 old_fs->group_desc_count);
 911         csum_flag = ext2fs_has_group_desc_csum(fs);
 912         if (!getenv("RESIZE2FS_FORCE_ITABLE_INIT") &&
 913             access("/sys/fs/ext4/features/lazy_itable_init", F_OK) == 0)
 914                 lazy_itable_init = 1;
 915         if (ext2fs_has_feature_meta_bg(fs->super))
 916                 old_desc_blocks = fs->super->s_first_meta_bg;
 917         else
 918                 old_desc_blocks = fs->desc_blocks +
 919                         fs->super->s_reserved_gdt_blocks;
 920
 921         /*
 922          * If we changed the number of block_group descriptor blocks,
 923          * we need to make sure they are all marked as reserved in the
 924          * file systems's block allocation map.
 925          */
 926         for (i = 0; i < old_fs->group_desc_count; i++)
 927                 ext2fs_reserve_super_and_bgd(fs, i, fs->block_map);
 928
 929         for (i = old_fs->group_desc_count;
 930              i < fs->group_desc_count; i++) {
 931                 memset(ext2fs_group_desc(fs, fs->group_desc, i), 0,
 932                        sizeof(struct ext2_group_desc));
 933                 adjblocks = 0;
 934
 935                 ext2fs_bg_flags_zap(fs, i);
 936                 if (csum_flag) {
 937                         ext2fs_bg_flags_set(fs, i, EXT2_BG_INODE_UNINIT);
 938                         if (!lazy_itable_init)
 939                                 ext2fs_bg_flags_set(fs, i,
 940                                                     EXT2_BG_INODE_ZEROED);
 941                         ext2fs_bg_itable_unused_set(fs, i,
 942                                         fs->super->s_inodes_per_group);
 943                 }
 944
 945                 numblocks = ext2fs_group_blocks_count(fs, i);
 946                 if ((i < fs->group_desc_count - 1) && csum_flag)
 947                         ext2fs_bg_flags_set(fs, i, EXT2_BG_BLOCK_UNINIT);
 948
 949                 has_super = ext2fs_bg_has_super(fs, i);
 950                 if (has_super) {
 951                         ext2fs_block_alloc_stats2(fs, group_block, +1);
 952                         adjblocks++;
 953                 }
 954                 meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
 955                 meta_bg = i / meta_bg_size;
 956                 if (!ext2fs_has_feature_meta_bg(fs->super) ||
 957                     (meta_bg < fs->super->s_first_meta_bg)) {
 958                         if (has_super) {
 959                                 for (j=0; j < old_desc_blocks; j++)
 960                                         ext2fs_block_alloc_stats2(fs,
 961                                                  group_block + 1 + j, +1);
 962                                 adjblocks += old_desc_blocks;
 963                         }
 964                 } else {
 965                         if (has_super)
 966                                 has_super = 1;
 967                         if (((i % meta_bg_size) == 0) ||
 968                             ((i % meta_bg_size) == 1) ||
 969                             ((i % meta_bg_size) == (meta_bg_size-1)))
 970                                 ext2fs_block_alloc_stats2(fs,
 971                                                  group_block + has_super, +1);
 972                 }
 973
 974                 adjblocks += 2 + fs->inode_blocks_per_group;
 975
 976                 numblocks -= adjblocks;
 977                 ext2fs_free_blocks_count_set(fs->super,
 978                              ext2fs_free_blocks_count(fs->super) - adjblocks);
 979                 fs->super->s_free_inodes_count +=
 980                         fs->super->s_inodes_per_group;
 981                 ext2fs_bg_free_blocks_count_set(fs, i, numblocks);
 982                 ext2fs_bg_free_inodes_count_set(fs, i,
 983                                                 fs->super->s_inodes_per_group);
 984                 ext2fs_bg_used_dirs_count_set(fs, i, 0);
 985                 ext2fs_group_desc_csum_set(fs, i);
 986
 987                 retval = ext2fs_allocate_group_table(fs, i, 0);
 988                 if (retval) goto errout;
 989
 990                 group_block += fs->super->s_blocks_per_group;
 991         }
 992         retval = 0;
 993
 994         /*
 995          * Mark all of the metadata blocks as reserved so they won't
 996          * get allocated by the call to ext2fs_allocate_group_table()
 997          * in blocks_to_move(), where we allocate new blocks to
 998          * replace those allocation bitmap and inode table blocks
 999          * which have to get relocated to make space for an increased
1000          * number of the block group descriptors.
1001          */
1002         if (reserve_blocks)
1003                 mark_table_blocks(fs, reserve_blocks);
1004
1005 errout:
1006         return (retval);
1007 }
1008
1009 /*
1010  * This routine adjusts the superblock and other data structures, both
1011  * in disk as well as in memory...
1012  */
1013 static errcode_t adjust_superblock(ext2_resize_t rfs, blk64_t new_size)
1014 {
1015         ext2_filsys     fs = rfs->new_fs;
1016         int             adj = 0;
1017         errcode_t       retval;
1018         blk64_t         group_block;
1019         unsigned long   i;
1020         unsigned long   max_group;
1021
1022         ext2fs_mark_super_dirty(fs);
1023         ext2fs_mark_bb_dirty(fs);
1024         ext2fs_mark_ib_dirty(fs);
1025
1026         retval = ext2fs_allocate_block_bitmap(fs, _("reserved blocks"),
1027                                               &rfs->reserve_blocks);
1028         if (retval)
1029                 return retval;
1030
1031         retval = adjust_fs_info(fs, rfs->old_fs, rfs->reserve_blocks, new_size);
1032         if (retval)
1033                 goto errout;
1034
1035         /*
1036          * Check to make sure there are enough inodes
1037          */
1038         if ((rfs->old_fs->super->s_inodes_count -
1039              rfs->old_fs->super->s_free_inodes_count) >
1040             rfs->new_fs->super->s_inodes_count) {
1041                 retval = ENOSPC;
1042                 goto errout;
1043         }
1044
1045         /*
1046          * If we are shrinking the number block groups, we're done and
1047          * can exit now.
1048          */
1049         if (rfs->old_fs->group_desc_count > fs->group_desc_count) {
1050                 retval = 0;
1051                 goto errout;
1052         }
1053
1054         /*
1055          * If the number of block groups is staying the same, we're
1056          * done and can exit now.  (If the number block groups is
1057          * shrinking, we had exited earlier.)
1058          */
1059         if (rfs->old_fs->group_desc_count >= fs->group_desc_count) {
1060                 retval = 0;
1061                 goto errout;
1062         }
1063
1064         /*
1065          * If we are using uninit_bg (aka GDT_CSUM) and the kernel
1066          * supports lazy inode initialization, we can skip
1067          * initializing the inode table.
1068          */
1069         if (lazy_itable_init && ext2fs_has_group_desc_csum(fs)) {
1070                 retval = 0;
1071                 goto errout;
1072         }
1073
1074         /*
1075          * Initialize the inode table
1076          */
1077         retval = ext2fs_get_array(fs->blocksize, fs->inode_blocks_per_group,
1078                                 &rfs->itable_buf);
1079         if (retval)
1080                 goto errout;
1081
1082         memset(rfs->itable_buf, 0, fs->blocksize * fs->inode_blocks_per_group);
1083         group_block = ext2fs_group_first_block2(fs,
1084                                                 rfs->old_fs->group_desc_count);
1085         adj = rfs->old_fs->group_desc_count;
1086         max_group = fs->group_desc_count - adj;
1087         if (rfs->progress) {
1088                 retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
1089                                        0, max_group);
1090                 if (retval)
1091                         goto errout;
1092         }
1093         for (i = rfs->old_fs->group_desc_count;
1094              i < fs->group_desc_count; i++) {
1095                 /*
1096                  * Write out the new inode table
1097                  */
1098                 retval = ext2fs_zero_blocks2(fs, ext2fs_inode_table_loc(fs, i),
1099                                              fs->inode_blocks_per_group, NULL,
1100                                              NULL);
1101                 if (retval)
1102                         goto errout;
1103
1104                 io_channel_flush(fs->io);
1105                 if (rfs->progress) {
1106                         retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
1107                                                i - adj + 1, max_group);
1108                         if (retval)
1109                                 goto errout;
1110                 }
1111                 group_block += fs->super->s_blocks_per_group;
1112         }
1113         io_channel_flush(fs->io);
1114         retval = 0;
1115
1116 errout:
1117         return retval;
1118 }
1119
1120 /* --------------------------------------------------------------------
1121  *
1122  * Resize processing, phase 2.
1123  *
1124  * In this phase we adjust determine which blocks need to be moved, in
1125  * blocks_to_move().  We then copy the blocks to their ultimate new
1126  * destinations using block_mover().  Since we are copying blocks to
1127  * their new locations, again during this pass we can abort without
1128  * any problems.
1129  * --------------------------------------------------------------------
1130  */
1131
1132 /*
1133  * This helper function creates a block bitmap with all of the
1134  * filesystem meta-data blocks.
1135  */
1136 static errcode_t mark_table_blocks(ext2_filsys fs,
1137                                    ext2fs_block_bitmap bmap)
1138 {
1139         dgrp_t                  i;
1140         blk64_t                 blk;
1141
1142         for (i = 0; i < fs->group_desc_count; i++) {
1143                 ext2fs_reserve_super_and_bgd(fs, i, bmap);
1144
1145                 /*
1146                  * Mark the blocks used for the inode table
1147                  */
1148                 blk = ext2fs_inode_table_loc(fs, i);
1149                 if (blk)
1150                         ext2fs_mark_block_bitmap_range2(bmap, blk,
1151                                                 fs->inode_blocks_per_group);
1152
1153                 /*
1154                  * Mark block used for the block bitmap
1155                  */
1156                 blk = ext2fs_block_bitmap_loc(fs, i);
1157                 if (blk)
1158                         ext2fs_mark_block_bitmap2(bmap, blk);
1159
1160                 /*
1161                  * Mark block used for the inode bitmap
1162                  */
1163                 blk = ext2fs_inode_bitmap_loc(fs, i);
1164                 if (blk)
1165                         ext2fs_mark_block_bitmap2(bmap, blk);
1166         }
1167         return 0;
1168 }
1169
1170 /*
1171  * This function checks to see if a particular block (either a
1172  * superblock or a block group descriptor) overlaps with an inode or
1173  * block bitmap block, or with the inode table.
1174  */
1175 static void mark_fs_metablock(ext2_resize_t rfs,
1176                               ext2fs_block_bitmap meta_bmap,
1177                               int group, blk64_t blk)
1178 {
1179         ext2_filsys fs = rfs->new_fs;
1180
1181         ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
1182         ext2fs_block_alloc_stats2(fs, blk, +1);
1183
1184         /*
1185          * Check to see if we overlap with the inode or block bitmap,
1186          * or the inode tables.  If not, and the block is in use, then
1187          * mark it as a block to be moved.
1188          */
1189         if (is_block_bm(fs, group, blk)) {
1190                 ext2fs_block_bitmap_loc_set(fs, group, 0);
1191                 rfs->needed_blocks++;
1192                 return;
1193         }
1194         if (is_inode_bm(fs, group, blk)) {
1195                 ext2fs_inode_bitmap_loc_set(fs, group, 0);
1196                 rfs->needed_blocks++;
1197                 return;
1198         }
1199         if (is_inode_tb(fs, group, blk)) {
1200                 ext2fs_inode_table_loc_set(fs, group, 0);
1201                 rfs->needed_blocks++;
1202                 return;
1203         }
1204         if (ext2fs_has_feature_flex_bg(fs->super)) {
1205                 dgrp_t i;
1206
1207                 for (i = 0; i < rfs->old_fs->group_desc_count; i++) {
1208                         if (is_block_bm(fs, i, blk)) {
1209                                 ext2fs_block_bitmap_loc_set(fs, i, 0);
1210                                 rfs->needed_blocks++;
1211                                 return;
1212                         }
1213                         if (is_inode_bm(fs, i, blk)) {
1214                                 ext2fs_inode_bitmap_loc_set(fs, i, 0);
1215                                 rfs->needed_blocks++;
1216                                 return;
1217                         }
1218                         if (is_inode_tb(fs, i, blk)) {
1219                                 ext2fs_inode_table_loc_set(fs, i, 0);
1220                                 rfs->needed_blocks++;
1221                                 return;
1222                         }
1223                 }
1224         }
1225
1226         if (ext2fs_has_group_desc_csum(fs) &&
1227             (ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT))) {
1228                 /*
1229                  * If the block bitmap is uninitialized, which means
1230                  * nothing other than standard metadata in use.
1231                  */
1232                 return;
1233         } else if (ext2fs_test_block_bitmap2(rfs->old_fs->block_map, blk) &&
1234                    !ext2fs_test_block_bitmap2(meta_bmap, blk)) {
1235                 ext2fs_mark_block_bitmap2(rfs->move_blocks, blk);
1236                 rfs->needed_blocks++;
1237         }
1238 }
1239
1240
1241 /*
1242  * This routine marks and unmarks reserved blocks in the new block
1243  * bitmap.  It also determines which blocks need to be moved and
1244  * places this information into the move_blocks bitmap.
1245  */
1246 static errcode_t blocks_to_move(ext2_resize_t rfs)
1247 {
1248         int             j, has_super;
1249         dgrp_t          i, max_groups, g;
1250         blk64_t         blk, group_blk;
1251         blk64_t         old_blocks, new_blocks, group_end, cluster_freed;
1252         blk64_t         new_size;
1253         unsigned int    meta_bg, meta_bg_size;
1254         errcode_t       retval;
1255         ext2_filsys     fs, old_fs;
1256         ext2fs_block_bitmap     meta_bmap, new_meta_bmap = NULL;
1257         int             flex_bg;
1258
1259         fs = rfs->new_fs;
1260         old_fs = rfs->old_fs;
1261         if (ext2fs_blocks_count(old_fs->super) > ext2fs_blocks_count(fs->super))
1262                 fs = rfs->old_fs;
1263
1264         retval = ext2fs_allocate_block_bitmap(fs, _("blocks to be moved"),
1265                                               &rfs->move_blocks);
1266         if (retval)
1267                 return retval;
1268
1269         retval = ext2fs_allocate_block_bitmap(fs, _("meta-data blocks"),
1270                                               &meta_bmap);
1271         if (retval)
1272                 return retval;
1273
1274         retval = mark_table_blocks(old_fs, meta_bmap);
1275         if (retval)
1276                 return retval;
1277
1278         fs = rfs->new_fs;
1279
1280         /*
1281          * If we're shrinking the filesystem, we need to move any
1282          * group's metadata blocks (either allocation bitmaps or the
1283          * inode table) which are beyond the end of the new
1284          * filesystem.
1285          */
1286         new_size = ext2fs_blocks_count(fs->super);
1287         if (new_size < ext2fs_blocks_count(old_fs->super)) {
1288                 for (g = 0; g < fs->group_desc_count; g++) {
1289                         int realloc = 0;
1290                         /*
1291                          * ext2fs_allocate_group_table will re-allocate any
1292                          * metadata blocks whose location is set to zero.
1293                          */
1294                         if (ext2fs_block_bitmap_loc(fs, g) >= new_size) {
1295                                 ext2fs_block_bitmap_loc_set(fs, g, 0);
1296                                 realloc = 1;
1297                         }
1298                         if (ext2fs_inode_bitmap_loc(fs, g) >= new_size) {
1299                                 ext2fs_inode_bitmap_loc_set(fs, g, 0);
1300                                 realloc = 1;
1301                         }
1302                         if ((ext2fs_inode_table_loc(fs, g) +
1303                              fs->inode_blocks_per_group) > new_size) {
1304                                 ext2fs_inode_table_loc_set(fs, g, 0);
1305                                 realloc = 1;
1306                         }
1307
1308                         if (realloc) {
1309                                 retval = ext2fs_allocate_group_table(fs, g, 0);
1310                                 if (retval)
1311                                         return retval;
1312                         }
1313                 }
1314         }
1315
1316         /*
1317          * If we're shrinking the filesystem, we need to move all of
1318          * the blocks that don't fit any more
1319          */
1320         for (blk = ext2fs_blocks_count(fs->super);
1321              blk < ext2fs_blocks_count(old_fs->super); blk++) {
1322                 g = ext2fs_group_of_blk2(fs, blk);
1323                 if (ext2fs_has_group_desc_csum(fs) &&
1324                     ext2fs_bg_flags_test(old_fs, g, EXT2_BG_BLOCK_UNINIT)) {
1325                         /*
1326                          * The block bitmap is uninitialized, so skip
1327                          * to the next block group.
1328                          */
1329                         blk = ext2fs_group_first_block2(fs, g+1) - 1;
1330                         continue;
1331                 }
1332                 if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
1333                     !ext2fs_test_block_bitmap2(meta_bmap, blk)) {
1334                         ext2fs_mark_block_bitmap2(rfs->move_blocks, blk);
1335                         rfs->needed_blocks++;
1336                 }
1337                 ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
1338         }
1339
1340         if (ext2fs_has_feature_meta_bg(old_fs->super))
1341                 old_blocks = old_fs->super->s_first_meta_bg;
1342         else
1343                 old_blocks = old_fs->desc_blocks +
1344                         old_fs->super->s_reserved_gdt_blocks;
1345         if (ext2fs_has_feature_meta_bg(fs->super))
1346                 new_blocks = fs->super->s_first_meta_bg;
1347         else
1348                 new_blocks = fs->desc_blocks + fs->super->s_reserved_gdt_blocks;
1349
1350         retval = reserve_sparse_super2_last_group(rfs, meta_bmap);
1351         if (retval)
1352                 goto errout;
1353
1354         if (EXT2_DESC_SIZE(rfs->old_fs->super) ==
1355             EXT2_DESC_SIZE(rfs->new_fs->super) &&
1356             old_blocks == new_blocks) {
1357                 retval = 0;
1358                 goto errout;
1359         }
1360
1361         max_groups = fs->group_desc_count;
1362         if (max_groups > old_fs->group_desc_count)
1363                 max_groups = old_fs->group_desc_count;
1364         group_blk = old_fs->super->s_first_data_block;
1365         /*
1366          * If we're reducing the number of descriptor blocks, this
1367          * makes life easy.  :-)   We just have to mark some extra
1368          * blocks as free.
1369          */
1370         if (old_blocks > new_blocks) {
1371                 if (EXT2FS_CLUSTER_RATIO(fs) > 1) {
1372                         retval = ext2fs_allocate_block_bitmap(fs,
1373                                                         _("new meta blocks"),
1374                                                         &new_meta_bmap);
1375                         if (retval)
1376                                 goto errout;
1377
1378                         retval = mark_table_blocks(fs, new_meta_bmap);
1379                         if (retval)
1380                                 goto errout;
1381                 }
1382
1383                 for (i = 0; i < max_groups; i++) {
1384                         if (!ext2fs_bg_has_super(old_fs, i)) {
1385                                 group_blk += fs->super->s_blocks_per_group;
1386                                 continue;
1387                         }
1388                         group_end = group_blk + 1 + old_blocks;
1389                         for (blk = group_blk + 1 + new_blocks;
1390                              blk < group_end;) {
1391                                 if (new_meta_bmap == NULL ||
1392                                     !ext2fs_test_block_bitmap2(new_meta_bmap,
1393                                                                blk)) {
1394                                         cluster_freed =
1395                                                 EXT2FS_CLUSTER_RATIO(fs) -
1396                                                 (blk &
1397                                                  EXT2FS_CLUSTER_MASK(fs));
1398                                         if (cluster_freed > group_end - blk)
1399                                                 cluster_freed = group_end - blk;
1400                                         ext2fs_block_alloc_stats2(fs, blk, -1);
1401                                         blk += EXT2FS_CLUSTER_RATIO(fs);
1402                                         rfs->needed_blocks -= cluster_freed;
1403                                         continue;
1404                                 }
1405                                 rfs->needed_blocks--;
1406                                 blk++;
1407                         }
1408                         group_blk += fs->super->s_blocks_per_group;
1409                 }
1410                 retval = 0;
1411                 goto errout;
1412         }
1413         /*
1414          * If we're increasing the number of descriptor blocks, life
1415          * gets interesting....
1416          */
1417         meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
1418         flex_bg = ext2fs_has_feature_flex_bg(fs->super);
1419         /* first reserve all of the existing fs meta blocks */
1420         for (i = 0; i < max_groups; i++) {
1421                 has_super = ext2fs_bg_has_super(fs, i);
1422                 if (has_super)
1423                         mark_fs_metablock(rfs, meta_bmap, i, group_blk);
1424
1425                 meta_bg = i / meta_bg_size;
1426                 if (!ext2fs_has_feature_meta_bg(fs->super) ||
1427                     (meta_bg < fs->super->s_first_meta_bg)) {
1428                         if (has_super) {
1429                                 for (blk = group_blk+1;
1430                                      blk < group_blk + 1 + new_blocks; blk++)
1431                                         mark_fs_metablock(rfs, meta_bmap,
1432                                                           i, blk);
1433                         }
1434                 } else {
1435                         if (has_super)
1436                                 has_super = 1;
1437                         if (((i % meta_bg_size) == 0) ||
1438                             ((i % meta_bg_size) == 1) ||
1439                             ((i % meta_bg_size) == (meta_bg_size-1)))
1440                                 mark_fs_metablock(rfs, meta_bmap, i,
1441                                                   group_blk + has_super);
1442                 }
1443
1444                 /*
1445                  * Reserve the existing meta blocks that we know
1446                  * aren't to be moved.
1447                  *
1448                  * For flex_bg file systems, in order to avoid
1449                  * overwriting fs metadata (especially inode table
1450                  * blocks) belonging to a different block group when
1451                  * we are relocating the inode tables, we need to
1452                  * reserve all existing fs metadata blocks.
1453                  */
1454                 if (ext2fs_block_bitmap_loc(fs, i))
1455                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
1456                                  ext2fs_block_bitmap_loc(fs, i));
1457                 else if (flex_bg && i < old_fs->group_desc_count)
1458                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
1459                                  ext2fs_block_bitmap_loc(old_fs, i));
1460
1461                 if (ext2fs_inode_bitmap_loc(fs, i))
1462                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
1463                                  ext2fs_inode_bitmap_loc(fs, i));
1464                 else if (flex_bg && i < old_fs->group_desc_count)
1465                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks,
1466                                  ext2fs_inode_bitmap_loc(old_fs, i));
1467
1468                 if (ext2fs_inode_table_loc(fs, i))
1469                         ext2fs_mark_block_bitmap_range2(rfs->reserve_blocks,
1470                                         ext2fs_inode_table_loc(fs, i),
1471                                         fs->inode_blocks_per_group);
1472                 else if (flex_bg && i < old_fs->group_desc_count)
1473                         ext2fs_mark_block_bitmap_range2(rfs->reserve_blocks,
1474                                         ext2fs_inode_table_loc(old_fs, i),
1475                                         old_fs->inode_blocks_per_group);
1476
1477                 group_blk += rfs->new_fs->super->s_blocks_per_group;
1478         }
1479
1480         /* Allocate the missing data structures */
1481         for (i = 0; i < max_groups; i++) {
1482                 if (ext2fs_inode_table_loc(fs, i) &&
1483                     ext2fs_inode_bitmap_loc(fs, i) &&
1484                     ext2fs_block_bitmap_loc(fs, i))
1485                         continue;
1486
1487                 retval = ext2fs_allocate_group_table(fs, i,
1488                                                      rfs->reserve_blocks);
1489                 if (retval)
1490                         goto errout;
1491
1492                 /*
1493                  * For those structures that have changed, we need to
1494                  * do bookkeepping.
1495                  */
1496                 if (ext2fs_block_bitmap_loc(old_fs, i) !=
1497                     (blk = ext2fs_block_bitmap_loc(fs, i))) {
1498                         ext2fs_block_alloc_stats2(fs, blk, +1);
1499                         if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
1500                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
1501                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
1502                                                          blk);
1503                 }
1504                 if (ext2fs_inode_bitmap_loc(old_fs, i) !=
1505                     (blk = ext2fs_inode_bitmap_loc(fs, i))) {
1506                         ext2fs_block_alloc_stats2(fs, blk, +1);
1507                         if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
1508                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
1509                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
1510                                                          blk);
1511                 }
1512
1513                 /*
1514                  * The inode table, if we need to relocate it, is
1515                  * handled specially.  We have to reserve the blocks
1516                  * for both the old and the new inode table, since we
1517                  * can't have the inode table be destroyed during the
1518                  * block relocation phase.
1519                  */
1520                 if (ext2fs_inode_table_loc(fs, i) == ext2fs_inode_table_loc(old_fs, i))
1521                         continue;       /* inode table not moved */
1522
1523                 rfs->needed_blocks += fs->inode_blocks_per_group;
1524
1525                 /*
1526                  * Mark the new inode table as in use in the new block
1527                  * allocation bitmap, and move any blocks that might
1528                  * be necessary.
1529                  */
1530                 for (blk = ext2fs_inode_table_loc(fs, i), j=0;
1531                      j < fs->inode_blocks_per_group ; j++, blk++) {
1532                         ext2fs_block_alloc_stats2(fs, blk, +1);
1533                         if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
1534                             !ext2fs_test_block_bitmap2(meta_bmap, blk))
1535                                 ext2fs_mark_block_bitmap2(rfs->move_blocks,
1536                                                          blk);
1537                 }
1538
1539                 /*
1540                  * Make sure the old inode table is reserved in the
1541                  * block reservation bitmap.
1542                  */
1543                 for (blk = ext2fs_inode_table_loc(rfs->old_fs, i), j=0;
1544                      j < fs->inode_blocks_per_group ; j++, blk++)
1545                         ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
1546         }
1547         retval = 0;
1548
1549 errout:
1550         if (new_meta_bmap)
1551                 ext2fs_free_block_bitmap(new_meta_bmap);
1552         if (meta_bmap)
1553                 ext2fs_free_block_bitmap(meta_bmap);
1554
1555         return retval;
1556 }
1557
1558 /*
1559  * This helper function tries to allocate a new block.  We try to
1560  * avoid hitting the original group descriptor blocks at least at
1561  * first, since we want to make it possible to recover from a badly
1562  * aborted resize operation as much as possible.
1563  *
1564  * In the future, I may further modify this routine to balance out
1565  * where we get the new blocks across the various block groups.
1566  * Ideally we would allocate blocks that corresponded with the block
1567  * group of the containing inode, and keep contiguous blocks
1568  * together.  However, this very difficult to do efficiently, since we
1569  * don't have the necessary information up front.
1570  */
1571
1572 #define AVOID_OLD       1
1573 #define DESPERATION     2
1574
1575 static void init_block_alloc(ext2_resize_t rfs)
1576 {
1577         rfs->alloc_state = AVOID_OLD;
1578         rfs->new_blk = rfs->new_fs->super->s_first_data_block;
1579 #if 0
1580         /* HACK for testing */
1581         if (ext2fs_blocks_count(rfs->new_fs->super) >
1582             ext2fs_blocks_count(rfs->old_fs->super))
1583                 rfs->new_blk = ext2fs_blocks_count(rfs->old_fs->super);
1584 #endif
1585 }
1586
1587 static blk64_t get_new_block(ext2_resize_t rfs)
1588 {
1589         ext2_filsys     fs = rfs->new_fs;
1590
1591         while (1) {
1592                 if (rfs->new_blk >= ext2fs_blocks_count(fs->super)) {
1593                         if (rfs->alloc_state == DESPERATION)
1594                                 return 0;
1595
1596 #ifdef RESIZE2FS_DEBUG
1597                         if (rfs->flags & RESIZE_DEBUG_BMOVE)
1598                                 printf("Going into desperation mode "
1599                                        "for block allocations\n");
1600 #endif
1601                         rfs->alloc_state = DESPERATION;
1602                         rfs->new_blk = fs->super->s_first_data_block;
1603                         continue;
1604                 }
1605                 if (ext2fs_test_block_bitmap2(fs->block_map, rfs->new_blk) ||
1606                     ext2fs_test_block_bitmap2(rfs->reserve_blocks,
1607                                              rfs->new_blk) ||
1608                     ((rfs->alloc_state == AVOID_OLD) &&
1609                      (rfs->new_blk < ext2fs_blocks_count(rfs->old_fs->super)) &&
1610                      ext2fs_test_block_bitmap2(rfs->old_fs->block_map,
1611                                               rfs->new_blk))) {
1612                         rfs->new_blk++;
1613                         continue;
1614                 }
1615                 return rfs->new_blk;
1616         }
1617 }
1618
1619 static errcode_t resize2fs_get_alloc_block(ext2_filsys fs,
1620                                            blk64_t goal EXT2FS_ATTR((unused)),
1621                                            blk64_t *ret)
1622 {
1623         ext2_resize_t rfs = (ext2_resize_t) fs->priv_data;
1624         blk64_t blk;
1625         int group;
1626
1627         blk = get_new_block(rfs);
1628         if (!blk)
1629                 return ENOSPC;
1630
1631 #ifdef RESIZE2FS_DEBUG
1632         if (rfs->flags & 0xF)
1633                 printf("get_alloc_block allocating %llu\n", blk);
1634 #endif
1635
1636         ext2fs_mark_block_bitmap2(rfs->old_fs->block_map, blk);
1637         ext2fs_mark_block_bitmap2(rfs->new_fs->block_map, blk);
1638
1639         group = ext2fs_group_of_blk2(rfs->old_fs, blk);
1640         ext2fs_clear_block_uninit(rfs->old_fs, group);
1641         group = ext2fs_group_of_blk2(rfs->new_fs, blk);
1642         ext2fs_clear_block_uninit(rfs->new_fs, group);
1643
1644         *ret = (blk64_t) blk;
1645         return 0;
1646 }
1647
1648 static errcode_t block_mover(ext2_resize_t rfs)
1649 {
1650         blk64_t                 blk, old_blk, new_blk;
1651         ext2_filsys             fs = rfs->new_fs;
1652         ext2_filsys             old_fs = rfs->old_fs;
1653         errcode_t               retval;
1654         __u64                   size;
1655         int                     c;
1656         int                     to_move, moved;
1657         ext2_badblocks_list     badblock_list = 0;
1658         int                     bb_modified = 0;
1659
1660         fs->get_alloc_block = resize2fs_get_alloc_block;
1661         old_fs->get_alloc_block = resize2fs_get_alloc_block;
1662
1663         retval = ext2fs_read_bb_inode(old_fs, &badblock_list);
1664         if (retval)
1665                 return retval;
1666
1667         new_blk = fs->super->s_first_data_block;
1668         if (!rfs->itable_buf) {
1669                 retval = ext2fs_get_array(fs->blocksize,
1670                                         fs->inode_blocks_per_group,
1671                                         &rfs->itable_buf);
1672                 if (retval)
1673                         return retval;
1674         }
1675         retval = ext2fs_create_extent_table(&rfs->bmap, 0);
1676         if (retval)
1677                 return retval;
1678
1679         /*
1680          * The first step is to figure out where all of the blocks
1681          * will go.
1682          */
1683         to_move = moved = 0;
1684         init_block_alloc(rfs);
1685         for (blk = B2C(old_fs->super->s_first_data_block);
1686              blk < ext2fs_blocks_count(old_fs->super);
1687              blk += EXT2FS_CLUSTER_RATIO(fs)) {
1688                 if (!ext2fs_test_block_bitmap2(old_fs->block_map, blk))
1689                         continue;
1690                 if (!ext2fs_test_block_bitmap2(rfs->move_blocks, blk))
1691                         continue;
1692                 if (ext2fs_badblocks_list_test(badblock_list, blk)) {
1693                         ext2fs_badblocks_list_del(badblock_list, blk);
1694                         bb_modified++;
1695                         continue;
1696                 }
1697
1698                 new_blk = get_new_block(rfs);
1699                 if (!new_blk) {
1700                         retval = ENOSPC;
1701                         goto errout;
1702                 }
1703                 ext2fs_block_alloc_stats2(fs, new_blk, +1);
1704                 ext2fs_add_extent_entry(rfs->bmap, B2C(blk), B2C(new_blk));
1705                 to_move++;
1706         }
1707
1708         if (to_move == 0) {
1709                 if (rfs->bmap) {
1710                         ext2fs_free_extent_table(rfs->bmap);
1711                         rfs->bmap = 0;
1712                 }
1713                 retval = 0;
1714                 goto errout;
1715         }
1716
1717         /*
1718          * Step two is to actually move the blocks
1719          */
1720         retval =  ext2fs_iterate_extent(rfs->bmap, 0, 0, 0);
1721         if (retval) goto errout;
1722
1723         if (rfs->progress) {
1724                 retval = (rfs->progress)(rfs, E2_RSZ_BLOCK_RELOC_PASS,
1725                                          0, to_move);
1726                 if (retval)
1727                         goto errout;
1728         }
1729         while (1) {
1730                 retval = ext2fs_iterate_extent(rfs->bmap, &old_blk, &new_blk, &size);
1731                 if (retval) goto errout;
1732                 if (!size)
1733                         break;
1734                 old_blk = C2B(old_blk);
1735                 new_blk = C2B(new_blk);
1736                 size = C2B(size);
1737 #ifdef RESIZE2FS_DEBUG
1738                 if (rfs->flags & RESIZE_DEBUG_BMOVE)
1739                         printf("Moving %llu blocks %llu->%llu\n",
1740                                size, old_blk, new_blk);
1741 #endif
1742                 do {
1743                         c = size;
1744                         if (c > fs->inode_blocks_per_group)
1745                                 c = fs->inode_blocks_per_group;
1746                         retval = io_channel_read_blk64(fs->io, old_blk, c,
1747                                                        rfs->itable_buf);
1748                         if (retval) goto errout;
1749                         retval = io_channel_write_blk64(fs->io, new_blk, c,
1750                                                         rfs->itable_buf);
1751                         if (retval) goto errout;
1752                         size -= c;
1753                         new_blk += c;
1754                         old_blk += c;
1755                         moved += c;
1756                         if (rfs->progress) {
1757                                 io_channel_flush(fs->io);
1758                                 retval = (rfs->progress)(rfs,
1759                                                 E2_RSZ_BLOCK_RELOC_PASS,
1760                                                 moved, to_move);
1761                                 if (retval)
1762                                         goto errout;
1763                         }
1764                 } while (size > 0);
1765                 io_channel_flush(fs->io);
1766         }
1767
1768 errout:
1769         if (badblock_list) {
1770                 if (!retval && bb_modified)
1771                         retval = ext2fs_update_bb_inode(old_fs,
1772                                                         badblock_list);
1773                 ext2fs_badblocks_list_free(badblock_list);
1774         }
1775         return retval;
1776 }
1777
1778
1779 /* --------------------------------------------------------------------
1780  *
1781  * Resize processing, phase 3
1782  *
1783  * --------------------------------------------------------------------
1784  */
1785
1786
1787 /*
1788  * The extent translation table is stored in clusters so we need to
1789  * take special care when mapping a source block number to its
1790  * destination block number.
1791  */
1792 static __u64 extent_translate(ext2_filsys fs, ext2_extent extent, __u64 old_loc)
1793 {
1794         __u64 new_block = C2B(ext2fs_extent_translate(extent, B2C(old_loc)));
1795
1796         if (new_block != 0)
1797                 new_block += old_loc & (EXT2FS_CLUSTER_RATIO(fs) - 1);
1798         return new_block;
1799 }
1800
1801 struct process_block_struct {
1802         ext2_resize_t           rfs;
1803         ext2_ino_t              ino;
1804         ext2_ino_t              old_ino;
1805         struct ext2_inode *     inode;
1806         errcode_t               error;
1807         int                     is_dir;
1808         int                     changed;
1809         int                     has_extents;
1810 };
1811
1812 static int process_block(ext2_filsys fs, blk64_t        *block_nr,
1813                          e2_blkcnt_t blockcnt,
1814                          blk64_t ref_block EXT2FS_ATTR((unused)),
1815                          int ref_offset EXT2FS_ATTR((unused)), void *priv_data)
1816 {
1817         struct process_block_struct *pb;
1818         errcode_t       retval;
1819         blk64_t         block, new_block;
1820         int             ret = 0;
1821
1822         pb = (struct process_block_struct *) priv_data;
1823         block = *block_nr;
1824         if (pb->rfs->bmap) {
1825                 new_block = extent_translate(fs, pb->rfs->bmap, block);
1826                 if (new_block) {
1827                         *block_nr = new_block;
1828                         ret |= BLOCK_CHANGED;
1829                         pb->changed = 1;
1830 #ifdef RESIZE2FS_DEBUG
1831                         if (pb->rfs->flags & RESIZE_DEBUG_BMOVE)
1832                                 printf("ino=%u, blockcnt=%lld, %llu->%llu\n",
1833                                        pb->old_ino, blockcnt, block,
1834                                        new_block);
1835 #endif
1836                         block = new_block;
1837                 }
1838         }
1839
1840         if (pb->is_dir) {
1841                 retval = ext2fs_add_dir_block2(fs->dblist, pb->ino,
1842                                                block, (int) blockcnt);
1843                 if (retval) {
1844                         pb->error = retval;
1845                         ret |= BLOCK_ABORT;
1846                 }
1847         }
1848         return ret;
1849 }
1850
1851 /*
1852  * Progress callback
1853  */
1854 static errcode_t progress_callback(ext2_filsys fs,
1855                                    ext2_inode_scan scan EXT2FS_ATTR((unused)),
1856                                    dgrp_t group, void * priv_data)
1857 {
1858         ext2_resize_t rfs = (ext2_resize_t) priv_data;
1859         errcode_t               retval;
1860
1861         /*
1862          * This check is to protect against old ext2 libraries.  It
1863          * shouldn't be needed against new libraries.
1864          */
1865         if ((group+1) == 0)
1866                 return 0;
1867
1868         if (rfs->progress) {
1869                 io_channel_flush(fs->io);
1870                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
1871                                          group+1, fs->group_desc_count);
1872                 if (retval)
1873                         return retval;
1874         }
1875
1876         return 0;
1877 }
1878
1879 static errcode_t migrate_ea_block(ext2_resize_t rfs, ext2_ino_t ino,
1880                                   struct ext2_inode *inode, int *changed)
1881 {
1882         char *buf = NULL;
1883         blk64_t new_block;
1884         errcode_t err = 0;
1885
1886         /* No EA block or no remapping?  Quit early. */
1887         if (ext2fs_file_acl_block(rfs->old_fs, inode) == 0 && !rfs->bmap)
1888                 return 0;
1889         new_block = extent_translate(rfs->old_fs, rfs->bmap,
1890                 ext2fs_file_acl_block(rfs->old_fs, inode));
1891         if (new_block == 0)
1892                 return 0;
1893
1894         /* Set the new ACL block */
1895         ext2fs_file_acl_block_set(rfs->old_fs, inode, new_block);
1896
1897         /* Update checksum */
1898         if (ext2fs_has_feature_metadata_csum(rfs->new_fs->super)) {
1899                 err = ext2fs_get_mem(rfs->old_fs->blocksize, &buf);
1900                 if (err)
1901                         return err;
1902                 rfs->old_fs->flags |= EXT2_FLAG_IGNORE_CSUM_ERRORS;
1903                 err = ext2fs_read_ext_attr3(rfs->old_fs, new_block, buf, ino);
1904                 rfs->old_fs->flags &= ~EXT2_FLAG_IGNORE_CSUM_ERRORS;
1905                 if (err)
1906                         goto out;
1907                 err = ext2fs_write_ext_attr3(rfs->old_fs, new_block, buf, ino);
1908                 if (err)
1909                         goto out;
1910         }
1911         *changed = 1;
1912
1913 out:
1914         ext2fs_free_mem(&buf);
1915         return err;
1916 }
1917
1918 /* Rewrite extents */
1919 static errcode_t rewrite_extents(ext2_filsys fs, ext2_ino_t ino)
1920 {
1921         ext2_extent_handle_t    handle;
1922         struct ext2fs_extent    extent;
1923         errcode_t               errcode;
1924         struct ext2_extent_info info;
1925
1926         errcode = ext2fs_extent_open(fs, ino, &handle);
1927         if (errcode)
1928                 return errcode;
1929
1930         errcode = ext2fs_extent_get(handle, EXT2_EXTENT_ROOT, &extent);
1931         if (errcode)
1932                 goto out;
1933
1934         do {
1935                 errcode = ext2fs_extent_get_info(handle, &info);
1936                 if (errcode)
1937                         break;
1938
1939                 /*
1940                  * If this is the first extent in an extent block that we
1941                  * haven't visited, rewrite the extent to force the ETB
1942                  * checksum to be rewritten.
1943                  */
1944                 if (info.curr_entry == 1 && info.curr_level != 0 &&
1945                     !(extent.e_flags & EXT2_EXTENT_FLAGS_SECOND_VISIT)) {
1946                         errcode = ext2fs_extent_replace(handle, 0, &extent);
1947                         if (errcode)
1948                                 break;
1949                 }
1950
1951                 /* Skip to the end of a block of leaf nodes */
1952                 if (extent.e_flags & EXT2_EXTENT_FLAGS_LEAF) {
1953                         errcode = ext2fs_extent_get(handle,
1954                                                     EXT2_EXTENT_LAST_SIB,
1955                                                     &extent);
1956                         if (errcode)
1957                                 break;
1958                 }
1959
1960                 errcode = ext2fs_extent_get(handle, EXT2_EXTENT_NEXT, &extent);
1961         } while (errcode == 0);
1962
1963 out:
1964         /* Ok if we run off the end */
1965         if (errcode == EXT2_ET_EXTENT_NO_NEXT)
1966                 errcode = 0;
1967         ext2fs_extent_free(handle);
1968         return errcode;
1969 }
1970
1971 static void quiet_com_err_proc(const char *whoami EXT2FS_ATTR((unused)),
1972                                errcode_t code EXT2FS_ATTR((unused)),
1973                                const char *fmt EXT2FS_ATTR((unused)),
1974                                va_list args EXT2FS_ATTR((unused)))
1975 {
1976 }
1977
1978 static errcode_t inode_scan_and_fix(ext2_resize_t rfs)
1979 {
1980         struct process_block_struct     pb;
1981         ext2_ino_t              ino, new_inode;
1982         struct ext2_inode       *inode = NULL;
1983         ext2_inode_scan         scan = NULL;
1984         errcode_t               retval;
1985         char                    *block_buf = 0;
1986         ext2_ino_t              start_to_move;
1987         int                     inode_size;
1988
1989         if ((rfs->old_fs->group_desc_count <=
1990              rfs->new_fs->group_desc_count) &&
1991             !rfs->bmap)
1992                 return 0;
1993
1994         set_com_err_hook(quiet_com_err_proc);
1995
1996         retval = ext2fs_open_inode_scan(rfs->old_fs, 0, &scan);
1997         if (retval) goto errout;
1998
1999         retval = ext2fs_init_dblist(rfs->old_fs, 0);
2000         if (retval) goto errout;
2001         retval = ext2fs_get_array(rfs->old_fs->blocksize, 3, &block_buf);
2002         if (retval) goto errout;
2003
2004         start_to_move = (rfs->new_fs->group_desc_count *
2005                          rfs->new_fs->super->s_inodes_per_group);
2006
2007         if (rfs->progress) {
2008                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
2009                                          0, rfs->old_fs->group_desc_count);
2010                 if (retval)
2011                         goto errout;
2012         }
2013         ext2fs_set_inode_callback(scan, progress_callback, (void *) rfs);
2014         pb.rfs = rfs;
2015         pb.inode = inode;
2016         pb.error = 0;
2017         new_inode = EXT2_FIRST_INODE(rfs->new_fs->super);
2018         inode_size = EXT2_INODE_SIZE(rfs->new_fs->super);
2019         inode = malloc(inode_size);
2020         if (!inode) {
2021                 retval = ENOMEM;
2022                 goto errout;
2023         }
2024         /*
2025          * First, copy all of the inodes that need to be moved
2026          * elsewhere in the inode table
2027          */
2028         while (1) {
2029                 retval = ext2fs_get_next_inode_full(scan, &ino, inode, inode_size);
2030                 if (retval) goto errout;
2031                 if (!ino)
2032                         break;
2033
2034                 if (inode->i_links_count == 0 && ino != EXT2_RESIZE_INO)
2035                         continue; /* inode not in use */
2036
2037                 pb.is_dir = LINUX_S_ISDIR(inode->i_mode);
2038                 pb.changed = 0;
2039
2040                 /* Remap EA block */
2041                 retval = migrate_ea_block(rfs, ino, inode, &pb.changed);
2042                 if (retval)
2043                         goto errout;
2044
2045                 new_inode = ino;
2046                 if (ino <= start_to_move)
2047                         goto remap_blocks; /* Don't need to move inode. */
2048
2049                 /*
2050                  * Find a new inode.  Now that extents and directory blocks
2051                  * are tied to the inode number through the checksum, we must
2052                  * set up the new inode before we start rewriting blocks.
2053                  */
2054                 retval = ext2fs_new_inode(rfs->new_fs, 0, 0, 0, &new_inode);
2055                 if (retval)
2056                         goto errout;
2057
2058                 ext2fs_inode_alloc_stats2(rfs->new_fs, new_inode, +1,
2059                                           pb.is_dir);
2060                 inode->i_ctime = time(0);
2061                 retval = ext2fs_write_inode_full(rfs->old_fs, new_inode,
2062                                                 inode, inode_size);
2063                 if (retval)
2064                         goto errout;
2065                 pb.changed = 0;
2066
2067 #ifdef RESIZE2FS_DEBUG
2068                 if (rfs->flags & RESIZE_DEBUG_INODEMAP)
2069                         printf("Inode moved %u->%u\n", ino, new_inode);
2070 #endif
2071                 if (!rfs->imap) {
2072                         retval = ext2fs_create_extent_table(&rfs->imap, 0);
2073                         if (retval)
2074                                 goto errout;
2075                 }
2076                 ext2fs_add_extent_entry(rfs->imap, ino, new_inode);
2077
2078 remap_blocks:
2079                 if (pb.changed)
2080                         retval = ext2fs_write_inode_full(rfs->old_fs,
2081                                                          new_inode,
2082                                                          inode, inode_size);
2083                 if (retval)
2084                         goto errout;
2085
2086                 /* Rewrite extent block checksums with new inode number */
2087                 if (ext2fs_has_feature_metadata_csum(rfs->old_fs->super) &&
2088                     (inode->i_flags & EXT4_EXTENTS_FL)) {
2089                         rfs->old_fs->flags |= EXT2_FLAG_IGNORE_CSUM_ERRORS;
2090                         retval = rewrite_extents(rfs->old_fs, new_inode);
2091                         rfs->old_fs->flags &= ~EXT2_FLAG_IGNORE_CSUM_ERRORS;
2092                         if (retval)
2093                                 goto errout;
2094                 }
2095
2096                 /*
2097                  * Update inodes to point to new blocks; schedule directory
2098                  * blocks for inode remapping.  Need to write out dir blocks
2099                  * with new inode numbers if we have metadata_csum enabled.
2100                  */
2101                 if (ext2fs_inode_has_valid_blocks2(rfs->old_fs, inode) &&
2102                     (rfs->bmap || pb.is_dir)) {
2103                         pb.ino = new_inode;
2104                         pb.old_ino = ino;
2105                         pb.has_extents = inode->i_flags & EXT4_EXTENTS_FL;
2106                         rfs->old_fs->flags |= EXT2_FLAG_IGNORE_CSUM_ERRORS;
2107                         retval = ext2fs_block_iterate3(rfs->old_fs,
2108                                                        new_inode, 0, block_buf,
2109                                                        process_block, &pb);
2110                         rfs->old_fs->flags &= ~EXT2_FLAG_IGNORE_CSUM_ERRORS;
2111                         if (retval)
2112                                 goto errout;
2113                         if (pb.error) {
2114                                 retval = pb.error;
2115                                 goto errout;
2116                         }
2117                 } else if ((inode->i_flags & EXT4_INLINE_DATA_FL) &&
2118                            (rfs->bmap || pb.is_dir)) {
2119                         /* inline data dir; update it too */
2120                         retval = ext2fs_add_dir_block2(rfs->old_fs->dblist,
2121                                                        new_inode, 0, 0);
2122                         if (retval)
2123                                 goto errout;
2124                 }
2125         }
2126         io_channel_flush(rfs->old_fs->io);
2127
2128 errout:
2129         reset_com_err_hook();
2130         if (rfs->bmap) {
2131                 ext2fs_free_extent_table(rfs->bmap);
2132                 rfs->bmap = 0;
2133         }
2134         if (scan)
2135                 ext2fs_close_inode_scan(scan);
2136         if (block_buf)
2137                 ext2fs_free_mem(&block_buf);
2138         free(inode);
2139         return retval;
2140 }
2141
2142 /* --------------------------------------------------------------------
2143  *
2144  * Resize processing, phase 4.
2145  *
2146  * --------------------------------------------------------------------
2147  */
2148
2149 struct istruct {
2150         ext2_resize_t rfs;
2151         errcode_t       err;
2152         unsigned int    max_dirs;
2153         unsigned int    num;
2154 };
2155
2156 static int check_and_change_inodes(ext2_ino_t dir,
2157                                    int entry EXT2FS_ATTR((unused)),
2158                                    struct ext2_dir_entry *dirent, int offset,
2159                                    int  blocksize EXT2FS_ATTR((unused)),
2160                                    char *buf EXT2FS_ATTR((unused)),
2161                                    void *priv_data)
2162 {
2163         struct istruct *is = (struct istruct *) priv_data;
2164         struct ext2_inode       inode;
2165         ext2_ino_t              new_inode;
2166         errcode_t               retval;
2167         int                     ret = 0;
2168
2169         if (is->rfs->progress && offset == 0) {
2170                 io_channel_flush(is->rfs->old_fs->io);
2171                 is->err = (is->rfs->progress)(is->rfs,
2172                                               E2_RSZ_INODE_REF_UPD_PASS,
2173                                               ++is->num, is->max_dirs);
2174                 if (is->err)
2175                         return DIRENT_ABORT;
2176         }
2177
2178         /*
2179          * If we have checksums enabled and the inode wasn't present in the
2180          * old fs, then we must rewrite all dir blocks with new checksums.
2181          */
2182         if (ext2fs_has_feature_metadata_csum(is->rfs->old_fs->super) &&
2183             !ext2fs_test_inode_bitmap2(is->rfs->old_fs->inode_map, dir))
2184                 ret |= DIRENT_CHANGED;
2185
2186         if (!dirent->inode)
2187                 return ret;
2188
2189         new_inode = ext2fs_extent_translate(is->rfs->imap, dirent->inode);
2190
2191         if (!new_inode)
2192                 return ret;
2193 #ifdef RESIZE2FS_DEBUG
2194         if (is->rfs->flags & RESIZE_DEBUG_INODEMAP)
2195                 printf("Inode translate (dir=%u, name=%.*s, %u->%u)\n",
2196                        dir, ext2fs_dirent_name_len(dirent), dirent->name,
2197                        dirent->inode, new_inode);
2198 #endif
2199
2200         dirent->inode = new_inode;
2201
2202         /* Update the directory mtime and ctime */
2203         retval = ext2fs_read_inode(is->rfs->old_fs, dir, &inode);
2204         if (retval == 0) {
2205                 inode.i_mtime = inode.i_ctime = time(0);
2206                 is->err = ext2fs_write_inode(is->rfs->old_fs, dir, &inode);
2207                 if (is->err)
2208                         return ret | DIRENT_ABORT;
2209         }
2210
2211         return ret | DIRENT_CHANGED;
2212 }
2213
2214 static errcode_t inode_ref_fix(ext2_resize_t rfs)
2215 {
2216         errcode_t               retval;
2217         struct istruct          is;
2218
2219         if (!rfs->imap)
2220                 return 0;
2221
2222         /*
2223          * Now, we iterate over all of the directories to update the
2224          * inode references
2225          */
2226         is.num = 0;
2227         is.max_dirs = ext2fs_dblist_count2(rfs->old_fs->dblist);
2228         is.rfs = rfs;
2229         is.err = 0;
2230
2231         if (rfs->progress) {
2232                 retval = (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS,
2233                                          0, is.max_dirs);
2234                 if (retval)
2235                         goto errout;
2236         }
2237
2238         rfs->old_fs->flags |= EXT2_FLAG_IGNORE_CSUM_ERRORS;
2239         retval = ext2fs_dblist_dir_iterate(rfs->old_fs->dblist,
2240                                            DIRENT_FLAG_INCLUDE_EMPTY, 0,
2241                                            check_and_change_inodes, &is);
2242         rfs->old_fs->flags &= ~EXT2_FLAG_IGNORE_CSUM_ERRORS;
2243         if (retval)
2244                 goto errout;
2245         if (is.err) {
2246                 retval = is.err;
2247                 goto errout;
2248         }
2249
2250         if (rfs->progress && (is.num < is.max_dirs))
2251                 (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS,
2252                                 is.max_dirs, is.max_dirs);
2253
2254 errout:
2255         ext2fs_free_extent_table(rfs->imap);
2256         rfs->imap = 0;
2257         return retval;
2258 }
2259
2260
2261 /* --------------------------------------------------------------------
2262  *
2263  * Resize processing, phase 5.
2264  *
2265  * In this phase we actually move the inode table around, and then
2266  * update the summary statistics.  This is scary, since aborting here
2267  * will potentially scramble the filesystem.  (We are moving the
2268  * inode tables around in place, and so the potential for lost data,
2269  * or at the very least scrambling the mapping between filenames and
2270  * inode numbers is very high in case of a power failure here.)
2271  * --------------------------------------------------------------------
2272  */
2273
2274
2275 /*
2276  * A very scary routine --- this one moves the inode table around!!!
2277  *
2278  * After this you have to use the rfs->new_fs file handle to read and
2279  * write inodes.
2280  */
2281 static errcode_t move_itables(ext2_resize_t rfs)
2282 {
2283         int             n, num, size;
2284         long long       diff;
2285         dgrp_t          i, max_groups;
2286         ext2_filsys     fs = rfs->new_fs;
2287         char            *cp;
2288         blk64_t         old_blk, new_blk, blk, cluster_freed;
2289         errcode_t       retval;
2290         int             j, to_move, moved;
2291         ext2fs_block_bitmap     new_bmap = NULL;
2292
2293         max_groups = fs->group_desc_count;
2294         if (max_groups > rfs->old_fs->group_desc_count)
2295                 max_groups = rfs->old_fs->group_desc_count;
2296
2297         size = fs->blocksize * fs->inode_blocks_per_group;
2298         if (!rfs->itable_buf) {
2299                 retval = ext2fs_get_mem(size, &rfs->itable_buf);
2300                 if (retval)
2301                         return retval;
2302         }
2303
2304         if (EXT2FS_CLUSTER_RATIO(fs) > 1) {
2305                 retval = ext2fs_allocate_block_bitmap(fs, _("new meta blocks"),
2306                                                       &new_bmap);
2307                 if (retval)
2308                         return retval;
2309
2310                 retval = mark_table_blocks(fs, new_bmap);
2311                 if (retval)
2312                         goto errout;
2313         }
2314
2315         /*
2316          * Figure out how many inode tables we need to move
2317          */
2318         to_move = moved = 0;
2319         for (i=0; i < max_groups; i++)
2320                 if (ext2fs_inode_table_loc(rfs->old_fs, i) !=
2321                     ext2fs_inode_table_loc(fs, i))
2322                         to_move++;
2323
2324         if (to_move == 0) {
2325                 retval = 0;
2326                 goto errout;
2327         }
2328
2329         if (rfs->progress) {
2330                 retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
2331                                        0, to_move);
2332                 if (retval)
2333                         goto errout;
2334         }
2335
2336         rfs->old_fs->flags |= EXT2_FLAG_MASTER_SB_ONLY;
2337
2338         for (i=0; i < max_groups; i++) {
2339                 old_blk = ext2fs_inode_table_loc(rfs->old_fs, i);
2340                 new_blk = ext2fs_inode_table_loc(fs, i);
2341                 diff = new_blk - old_blk;
2342
2343 #ifdef RESIZE2FS_DEBUG
2344                 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
2345                         printf("Itable move group %d block %llu->%llu (diff %lld)\n",
2346                                i, old_blk, new_blk, diff);
2347 #endif
2348
2349                 if (!diff)
2350                         continue;
2351                 if (diff < 0)
2352                         diff = 0;
2353
2354                 retval = io_channel_read_blk64(fs->io, old_blk,
2355                                                fs->inode_blocks_per_group,
2356                                                rfs->itable_buf);
2357                 if (retval)
2358                         goto errout;
2359                 /*
2360                  * The end of the inode table segment often contains
2361                  * all zeros, and we're often only moving the inode
2362                  * table down a block or two.  If so, we can optimize
2363                  * things by not rewriting blocks that we know to be zero
2364                  * already.
2365                  */
2366                 for (cp = rfs->itable_buf+size-1, n=0; n < size; n++, cp--)
2367                         if (*cp)
2368                                 break;
2369                 n = n >> EXT2_BLOCK_SIZE_BITS(fs->super);
2370 #ifdef RESIZE2FS_DEBUG
2371                 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
2372                         printf("%d blocks of zeros...\n", n);
2373 #endif
2374                 num = fs->inode_blocks_per_group;
2375                 if (n > diff)
2376                         num -= n;
2377
2378                 retval = io_channel_write_blk64(fs->io, new_blk,
2379                                                 num, rfs->itable_buf);
2380                 if (retval) {
2381                         io_channel_write_blk64(fs->io, old_blk,
2382                                                num, rfs->itable_buf);
2383                         goto errout;
2384                 }
2385                 if (n > diff) {
2386                         retval = io_channel_write_blk64(fs->io,
2387                               old_blk + fs->inode_blocks_per_group,
2388                               diff, (rfs->itable_buf +
2389                                      (fs->inode_blocks_per_group - diff) *
2390                                      fs->blocksize));
2391                         if (retval)
2392                                 goto errout;
2393                 }
2394
2395                 for (blk = ext2fs_inode_table_loc(rfs->old_fs, i), j=0;
2396                      j < fs->inode_blocks_per_group;) {
2397                         if (new_bmap == NULL ||
2398                             !ext2fs_test_block_bitmap2(new_bmap, blk)) {
2399                                 ext2fs_block_alloc_stats2(fs, blk, -1);
2400                                 cluster_freed = EXT2FS_CLUSTER_RATIO(fs) -
2401                                                 (blk & EXT2FS_CLUSTER_MASK(fs));
2402                                 blk += cluster_freed;
2403                                 j += cluster_freed;
2404                                 continue;
2405                         }
2406                         blk++;
2407                         j++;
2408                 }
2409
2410                 ext2fs_inode_table_loc_set(rfs->old_fs, i, new_blk);
2411                 ext2fs_group_desc_csum_set(rfs->old_fs, i);
2412                 ext2fs_mark_super_dirty(rfs->old_fs);
2413                 ext2fs_flush(rfs->old_fs);
2414
2415                 if (rfs->progress) {
2416                         retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
2417                                                ++moved, to_move);
2418                         if (retval)
2419                                 goto errout;
2420                 }
2421         }
2422         mark_table_blocks(fs, fs->block_map);
2423         ext2fs_flush(fs);
2424 #ifdef RESIZE2FS_DEBUG
2425         if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
2426                 printf("Inode table move finished.\n");
2427 #endif
2428         retval = 0;
2429
2430 errout:
2431         if (new_bmap)
2432                 ext2fs_free_block_bitmap(new_bmap);
2433         return retval;
2434 }
2435
2436 /*
2437  * This function is used when expanding a file system.  It frees the
2438  * superblock and block group descriptor blocks from the block group
2439  * which is no longer the last block group.
2440  */
2441 static errcode_t clear_sparse_super2_last_group(ext2_resize_t rfs)
2442 {
2443         ext2_filsys     fs = rfs->new_fs;
2444         ext2_filsys     old_fs = rfs->old_fs;
2445         errcode_t       retval;
2446         dgrp_t          old_last_bg = rfs->old_fs->group_desc_count - 1;
2447         dgrp_t          last_bg = fs->group_desc_count - 1;
2448         blk64_t         sb, old_desc;
2449         blk_t           num;
2450
2451         if (!ext2fs_has_feature_sparse_super2(fs->super))
2452                 return 0;
2453
2454         if (last_bg <= old_last_bg)
2455                 return 0;
2456
2457         if (fs->super->s_backup_bgs[0] == old_fs->super->s_backup_bgs[0] &&
2458             fs->super->s_backup_bgs[1] == old_fs->super->s_backup_bgs[1])
2459                 return 0;
2460
2461         if (old_fs->super->s_backup_bgs[0] != old_last_bg &&
2462             old_fs->super->s_backup_bgs[1] != old_last_bg)
2463                 return 0;
2464
2465         if (fs->super->s_backup_bgs[0] == old_last_bg ||
2466             fs->super->s_backup_bgs[1] == old_last_bg)
2467                 return 0;
2468
2469         retval = ext2fs_super_and_bgd_loc2(rfs->old_fs, old_last_bg,
2470                                            &sb, &old_desc, NULL, &num);
2471         if (retval)
2472                 return retval;
2473
2474         if (sb)
2475                 ext2fs_unmark_block_bitmap2(fs->block_map, sb);
2476         if (old_desc)
2477                 ext2fs_unmark_block_bitmap_range2(fs->block_map, old_desc, num);
2478         return 0;
2479 }
2480
2481 /*
2482  * This function is used when shrinking a file system.  We need to
2483  * utilize blocks from what will be the new last block group for the
2484  * backup superblock and block group descriptor blocks.
2485  * Unfortunately, those blocks may be used by other files or fs
2486  * metadata blocks.  We need to mark them as being in use.
2487  */
2488 static errcode_t reserve_sparse_super2_last_group(ext2_resize_t rfs,
2489                                                  ext2fs_block_bitmap meta_bmap)
2490 {
2491         ext2_filsys     fs = rfs->new_fs;
2492         ext2_filsys     old_fs = rfs->old_fs;
2493         errcode_t       retval;
2494         dgrp_t          old_last_bg = rfs->old_fs->group_desc_count - 1;
2495         dgrp_t          last_bg = fs->group_desc_count - 1;
2496         dgrp_t          g;
2497         blk64_t         blk, sb, old_desc;
2498         blk_t           i, num;
2499         int             realloc = 0;
2500
2501         if (!ext2fs_has_feature_sparse_super2(fs->super))
2502                 return 0;
2503
2504         if (last_bg >= old_last_bg)
2505                 return 0;
2506
2507         if (fs->super->s_backup_bgs[0] == old_fs->super->s_backup_bgs[0] &&
2508             fs->super->s_backup_bgs[1] == old_fs->super->s_backup_bgs[1])
2509                 return 0;
2510
2511         if (fs->super->s_backup_bgs[0] != last_bg &&
2512             fs->super->s_backup_bgs[1] != last_bg)
2513                 return 0;
2514
2515         if (old_fs->super->s_backup_bgs[0] == last_bg ||
2516             old_fs->super->s_backup_bgs[1] == last_bg)
2517                 return 0;
2518
2519         retval = ext2fs_super_and_bgd_loc2(rfs->new_fs, last_bg,
2520                                            &sb, &old_desc, NULL, &num);
2521         if (retval)
2522                 return retval;
2523
2524         if (last_bg && !sb) {
2525                 fputs(_("Should never happen!  No sb in last super_sparse bg?\n"),
2526                       stderr);
2527                 exit(1);
2528         }
2529         if (old_desc && old_desc != sb+1) {
2530                 fputs(_("Should never happen!  Unexpected old_desc in "
2531                         "super_sparse bg?\n"),
2532                       stderr);
2533                 exit(1);
2534         }
2535         num = (old_desc) ? num : 1;
2536
2537         /* Reserve the backup blocks */
2538         ext2fs_mark_block_bitmap_range2(fs->block_map, sb, num);
2539
2540         for (g = 0; g < fs->group_desc_count; g++) {
2541                 blk64_t mb;
2542
2543                 mb = ext2fs_block_bitmap_loc(fs, g);
2544                 if ((mb >= sb) && (mb < sb + num)) {
2545                         ext2fs_block_bitmap_loc_set(fs, g, 0);
2546                         realloc = 1;
2547                 }
2548                 mb = ext2fs_inode_bitmap_loc(fs, g);
2549                 if ((mb >= sb) && (mb < sb + num)) {
2550                         ext2fs_inode_bitmap_loc_set(fs, g, 0);
2551                         realloc = 1;
2552                 }
2553                 mb = ext2fs_inode_table_loc(fs, g);
2554                 if ((mb < sb + num) &&
2555                     (sb < mb + fs->inode_blocks_per_group)) {
2556                         ext2fs_inode_table_loc_set(fs, g, 0);
2557                         realloc = 1;
2558                 }
2559                 if (realloc) {
2560                         retval = ext2fs_allocate_group_table(fs, g, 0);
2561                         if (retval)
2562                                 return retval;
2563                 }
2564         }
2565
2566         for (blk = sb, i = 0; i < num; blk++, i++) {
2567                 if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) &&
2568                     !ext2fs_test_block_bitmap2(meta_bmap, blk)) {
2569                         ext2fs_mark_block_bitmap2(rfs->move_blocks, blk);
2570                         rfs->needed_blocks++;
2571                 }
2572                 ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk);
2573         }
2574         return 0;
2575 }
2576
2577 /*
2578  * Fix the resize inode
2579  */
2580 static errcode_t fix_resize_inode(ext2_filsys fs)
2581 {
2582         struct ext2_inode       inode;
2583         errcode_t               retval;
2584
2585         if (!ext2fs_has_feature_resize_inode(fs->super))
2586                 return 0;
2587
2588         retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode);
2589         if (retval) goto errout;
2590
2591         ext2fs_iblk_set(fs, &inode, 1);
2592
2593         retval = ext2fs_write_inode(fs, EXT2_RESIZE_INO, &inode);
2594         if (retval) goto errout;
2595
2596         if (!inode.i_block[EXT2_DIND_BLOCK]) {
2597                 /*
2598                  * Avoid zeroing out block #0; that's rude.  This
2599                  * should never happen anyway since the filesystem
2600                  * should be fsck'ed and we assume it is consistent.
2601                  */
2602                 fprintf(stderr, "%s",
2603                         _("Should never happen: resize inode corrupt!\n"));
2604                 exit(1);
2605         }
2606
2607         retval = ext2fs_zero_blocks2(fs, inode.i_block[EXT2_DIND_BLOCK], 1,
2608                                      NULL, NULL);
2609         if (retval)
2610                 goto errout;
2611
2612         retval = ext2fs_create_resize_inode(fs);
2613         if (retval)
2614                 goto errout;
2615
2616 errout:
2617         return retval;
2618 }
2619
2620 /*
2621  * Finally, recalculate the summary information
2622  */
2623 static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs)
2624 {
2625         blk64_t         blk;
2626         ext2_ino_t      ino;
2627         unsigned int    group = 0;
2628         unsigned int    count = 0;
2629         blk64_t         total_blocks_free = 0;
2630         int             total_inodes_free = 0;
2631         int             group_free = 0;
2632         int             uninit = 0;
2633         blk64_t         super_blk, old_desc_blk, new_desc_blk;
2634         int             old_desc_blocks;
2635
2636         /*
2637          * First calculate the block statistics
2638          */
2639         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT);
2640         ext2fs_super_and_bgd_loc2(fs, group, &super_blk, &old_desc_blk,
2641                                   &new_desc_blk, 0);
2642         if (ext2fs_has_feature_meta_bg(fs->super))
2643                 old_desc_blocks = fs->super->s_first_meta_bg;
2644         else
2645                 old_desc_blocks = fs->desc_blocks +
2646                         fs->super->s_reserved_gdt_blocks;
2647         for (blk = B2C(fs->super->s_first_data_block);
2648              blk < ext2fs_blocks_count(fs->super);
2649              blk += EXT2FS_CLUSTER_RATIO(fs)) {
2650                 if ((uninit &&
2651                      !(EQ_CLSTR(blk, super_blk) ||
2652                        ((old_desc_blk && old_desc_blocks &&
2653                          GE_CLSTR(blk, old_desc_blk) &&
2654                          LT_CLSTR(blk, old_desc_blk + old_desc_blocks))) ||
2655                        ((new_desc_blk && EQ_CLSTR(blk, new_desc_blk))) ||
2656                        EQ_CLSTR(blk, ext2fs_block_bitmap_loc(fs, group)) ||
2657                        EQ_CLSTR(blk, ext2fs_inode_bitmap_loc(fs, group)) ||
2658                        ((GE_CLSTR(blk, ext2fs_inode_table_loc(fs, group)) &&
2659                          LT_CLSTR(blk, ext2fs_inode_table_loc(fs, group)
2660                                   + fs->inode_blocks_per_group))))) ||
2661                     (!ext2fs_fast_test_block_bitmap2(fs->block_map, blk))) {
2662                         group_free++;
2663                         total_blocks_free++;
2664                 }
2665                 count++;
2666                 if ((count == fs->super->s_clusters_per_group) ||
2667                     EQ_CLSTR(blk, ext2fs_blocks_count(fs->super)-1)) {
2668                         ext2fs_bg_free_blocks_count_set(fs, group, group_free);
2669                         ext2fs_group_desc_csum_set(fs, group);
2670                         group++;
2671                         if (group >= fs->group_desc_count)
2672                                 break;
2673                         count = 0;
2674                         group_free = 0;
2675                         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT);
2676                         ext2fs_super_and_bgd_loc2(fs, group, &super_blk,
2677                                                   &old_desc_blk,
2678                                                   &new_desc_blk, 0);
2679                         if (ext2fs_has_feature_meta_bg(fs->super))
2680                                 old_desc_blocks = fs->super->s_first_meta_bg;
2681                         else
2682                                 old_desc_blocks = fs->desc_blocks +
2683                                         fs->super->s_reserved_gdt_blocks;
2684                 }
2685         }
2686         total_blocks_free = C2B(total_blocks_free);
2687         ext2fs_free_blocks_count_set(fs->super, total_blocks_free);
2688
2689         /*
2690          * Next, calculate the inode statistics
2691          */
2692         group_free = 0;
2693         count = 0;
2694         group = 0;
2695
2696         /* Protect loop from wrap-around if s_inodes_count maxed */
2697         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT);
2698         for (ino = 1; ino <= fs->super->s_inodes_count && ino > 0; ino++) {
2699                 if (uninit ||
2700                     !ext2fs_fast_test_inode_bitmap2(fs->inode_map, ino)) {
2701                         group_free++;
2702                         total_inodes_free++;
2703                 }
2704                 count++;
2705                 if ((count == fs->super->s_inodes_per_group) ||
2706                     (ino == fs->super->s_inodes_count)) {
2707                         ext2fs_bg_free_inodes_count_set(fs, group, group_free);
2708                         ext2fs_group_desc_csum_set(fs, group);
2709                         group++;
2710                         if (group >= fs->group_desc_count)
2711                                 break;
2712                         count = 0;
2713                         group_free = 0;
2714                         uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT);
2715                 }
2716         }
2717         fs->super->s_free_inodes_count = total_inodes_free;
2718         ext2fs_mark_super_dirty(fs);
2719         return 0;
2720 }
2721
2722 /*
2723  *  Journal may have been relocated; update the backup journal blocks
2724  *  in the superblock.
2725  */
2726 static errcode_t fix_sb_journal_backup(ext2_filsys fs)
2727 {
2728         errcode_t         retval;
2729         struct ext2_inode inode;
2730
2731         if (!ext2fs_has_feature_journal(fs->super))
2732                 return 0;
2733
2734         /* External journal? Nothing to do. */
2735         if (fs->super->s_journal_dev && !fs->super->s_journal_inum)
2736                 return 0;
2737
2738         retval = ext2fs_read_inode(fs, fs->super->s_journal_inum, &inode);
2739         if (retval)
2740                 return retval;
2741         memcpy(fs->super->s_jnl_blocks, inode.i_block, EXT2_N_BLOCKS*4);
2742         fs->super->s_jnl_blocks[15] = inode.i_size_high;
2743         fs->super->s_jnl_blocks[16] = inode.i_size;
2744         fs->super->s_jnl_backup_type = EXT3_JNL_BACKUP_BLOCKS;
2745         ext2fs_mark_super_dirty(fs);
2746         return 0;
2747 }
2748
2749 static int calc_group_overhead(ext2_filsys fs, blk64_t grp,
2750                                int old_desc_blocks)
2751 {
2752         blk64_t super_blk, old_desc_blk, new_desc_blk;
2753         int overhead;
2754
2755         /* inode table blocks plus allocation bitmaps */
2756         overhead = fs->inode_blocks_per_group + 2;
2757
2758         ext2fs_super_and_bgd_loc2(fs, grp, &super_blk,
2759                                   &old_desc_blk, &new_desc_blk, 0);
2760         if ((grp == 0) || super_blk)
2761                 overhead++;
2762         if (old_desc_blk)
2763                 overhead += old_desc_blocks;
2764         else if (new_desc_blk)
2765                 overhead++;
2766         return overhead;
2767 }
2768
2769
2770 /*
2771  * calcluate the minimum number of blocks the given fs can be resized to
2772  */
2773 blk64_t calculate_minimum_resize_size(ext2_filsys fs, int flags)
2774 {
2775         ext2_ino_t inode_count;
2776         dgrp_t groups, flex_groups;
2777         blk64_t blks_needed, data_blocks;
2778         blk64_t grp, data_needed, last_start;
2779         blk64_t overhead = 0;
2780         int old_desc_blocks;
2781         int flexbg_size = 1 << fs->super->s_log_groups_per_flex;
2782
2783         /*
2784          * first figure out how many group descriptors we need to
2785          * handle the number of inodes we have
2786          */
2787         inode_count = fs->super->s_inodes_count -
2788                 fs->super->s_free_inodes_count;
2789         blks_needed = ext2fs_div_ceil(inode_count,
2790                                       fs->super->s_inodes_per_group) *
2791                 (blk64_t) EXT2_BLOCKS_PER_GROUP(fs->super);
2792         groups = ext2fs_div64_ceil(blks_needed,
2793                                    EXT2_BLOCKS_PER_GROUP(fs->super));
2794 #ifdef RESIZE2FS_DEBUG
2795         if (flags & RESIZE_DEBUG_MIN_CALC)
2796                 printf("fs has %d inodes, %d groups required.\n",
2797                        inode_count, groups);
2798 #endif
2799
2800         /*
2801          * number of old-style block group descriptor blocks
2802          */
2803         if (ext2fs_has_feature_meta_bg(fs->super))
2804                 old_desc_blocks = fs->super->s_first_meta_bg;
2805         else
2806                 old_desc_blocks = fs->desc_blocks +
2807                         fs->super->s_reserved_gdt_blocks;
2808
2809         /* calculate how many blocks are needed for data */
2810         data_needed = ext2fs_blocks_count(fs->super) -
2811                 ext2fs_free_blocks_count(fs->super);
2812
2813         for (grp = 0; grp < fs->group_desc_count; grp++)
2814                 data_needed -= calc_group_overhead(fs, grp, old_desc_blocks);
2815 #ifdef RESIZE2FS_DEBUG
2816         if (flags & RESIZE_DEBUG_MIN_CALC)
2817                 printf("fs requires %llu data blocks.\n", data_needed);
2818 #endif
2819
2820         /*
2821          * For ext4 we need to allow for up to a flex_bg worth of
2822          * inode tables of slack space so the resize operation can be
2823          * guaranteed to finish.
2824          */
2825         flex_groups = groups;
2826         if (ext2fs_has_feature_flex_bg(fs->super)) {
2827                 dgrp_t remainder = groups & (flexbg_size - 1);
2828
2829                 flex_groups += flexbg_size - remainder;
2830                 if (flex_groups > fs->group_desc_count)
2831                         flex_groups = fs->group_desc_count;
2832         }
2833
2834         /*
2835          * figure out how many data blocks we have given the number of groups
2836          * we need for our inodes
2837          */
2838         data_blocks = EXT2_GROUPS_TO_BLOCKS(fs->super, groups);
2839         last_start = 0;
2840         for (grp = 0; grp < flex_groups; grp++) {
2841                 overhead = calc_group_overhead(fs, grp, old_desc_blocks);
2842
2843                 /*
2844                  * we want to keep track of how much data we can store in
2845                  * the groups leading up to the last group so we can determine
2846                  * how big the last group needs to be
2847                  */
2848                 if (grp < (groups - 1))
2849                         last_start += EXT2_BLOCKS_PER_GROUP(fs->super) -
2850                                 overhead;
2851
2852                 if (data_blocks > overhead)
2853                         data_blocks -= overhead;
2854                 else
2855                         data_blocks = 0;
2856         }
2857 #ifdef RESIZE2FS_DEBUG
2858         if (flags & RESIZE_DEBUG_MIN_CALC)
2859                 printf("With %d group(s), we have %llu blocks available.\n",
2860                        groups, data_blocks);
2861 #endif
2862
2863         /*
2864          * if we need more group descriptors in order to accomodate our data
2865          * then we need to add them here
2866          */
2867         blks_needed = data_needed;
2868         while (blks_needed > data_blocks) {
2869                 blk64_t remainder = blks_needed - data_blocks;
2870                 dgrp_t extra_grps;
2871
2872                 /* figure out how many more groups we need for the data */
2873                 extra_grps = ext2fs_div64_ceil(remainder,
2874                                                EXT2_BLOCKS_PER_GROUP(fs->super));
2875
2876                 data_blocks += EXT2_GROUPS_TO_BLOCKS(fs->super, extra_grps);
2877
2878                 /* ok we have to account for the last group */
2879                 overhead = calc_group_overhead(fs, groups-1, old_desc_blocks);
2880                 last_start += EXT2_BLOCKS_PER_GROUP(fs->super) - overhead;
2881
2882                 grp = flex_groups;
2883                 groups += extra_grps;
2884                 if (!ext2fs_has_feature_flex_bg(fs->super))
2885                         flex_groups = groups;
2886                 else if (groups > flex_groups) {
2887                         dgrp_t r = groups & (flexbg_size - 1);
2888
2889                         flex_groups = groups + flexbg_size - r;
2890                         if (flex_groups > fs->group_desc_count)
2891                                 flex_groups = fs->group_desc_count;
2892                 }
2893
2894                 for (; grp < flex_groups; grp++) {
2895                         overhead = calc_group_overhead(fs, grp,
2896                                                        old_desc_blocks);
2897
2898                         /*
2899                          * again, we need to see how much data we cram into
2900                          * all of the groups leading up to the last group
2901                          */
2902                         if (grp < groups - 1)
2903                                 last_start += EXT2_BLOCKS_PER_GROUP(fs->super)
2904                                         - overhead;
2905
2906                         data_blocks -= overhead;
2907                 }
2908
2909 #ifdef RESIZE2FS_DEBUG
2910                 if (flags & RESIZE_DEBUG_MIN_CALC)
2911                         printf("Added %d extra group(s), "
2912                                "blks_needed %llu, data_blocks %llu, "
2913                                "last_start %llu\n", extra_grps, blks_needed,
2914                                data_blocks, last_start);
2915 #endif
2916         }
2917
2918         /* now for the fun voodoo */
2919         grp = groups - 1;
2920         if (ext2fs_has_feature_flex_bg(fs->super) &&
2921             (grp & ~(flexbg_size - 1)) == 0)
2922                 grp = grp & ~(flexbg_size - 1);
2923         overhead = 0;
2924         for (; grp < flex_groups; grp++)
2925                 overhead += calc_group_overhead(fs, grp, old_desc_blocks);
2926
2927 #ifdef RESIZE2FS_DEBUG
2928         if (flags & RESIZE_DEBUG_MIN_CALC)
2929                 printf("Last group's overhead is %llu\n", overhead);
2930 #endif
2931
2932         /*
2933          * if this is the case then the last group is going to have data in it
2934          * so we need to adjust the size of the last group accordingly
2935          */
2936         if (last_start < blks_needed) {
2937                 blk64_t remainder = blks_needed - last_start;
2938
2939 #ifdef RESIZE2FS_DEBUG
2940                 if (flags & RESIZE_DEBUG_MIN_CALC)
2941                         printf("Need %llu data blocks in last group\n",
2942                                remainder);
2943 #endif
2944                 /*
2945                  * 50 is a magic number that mkfs/resize uses to see if its
2946                  * even worth making/resizing the fs.  basically you need to
2947                  * have at least 50 blocks in addition to the blocks needed
2948                  * for the metadata in the last group
2949                  */
2950                 if (remainder > 50)
2951                         overhead += remainder;
2952                 else
2953                         overhead += 50;
2954         } else
2955                 overhead += 50;
2956
2957         overhead += fs->super->s_first_data_block;
2958 #ifdef RESIZE2FS_DEBUG
2959         if (flags & RESIZE_DEBUG_MIN_CALC)
2960                 printf("Final size of last group is %lld\n", overhead);
2961 #endif
2962
2963         /* Add extra slack for bigalloc file systems */
2964         if (EXT2FS_CLUSTER_RATIO(fs) > 1)
2965                 overhead += EXT2FS_CLUSTER_RATIO(fs) * 2;
2966
2967         /*
2968          * since our last group doesn't have to be BLOCKS_PER_GROUP
2969          * large, we only do groups-1, and then add the number of
2970          * blocks needed to handle the group descriptor metadata+data
2971          * that we need
2972          */
2973         blks_needed = EXT2_GROUPS_TO_BLOCKS(fs->super, groups - 1);
2974         blks_needed += overhead;
2975
2976         /*
2977          * Make sure blks_needed covers the end of the inode table in
2978          * the last block group.
2979          */
2980         overhead = ext2fs_inode_table_loc(fs, groups-1) +
2981                 fs->inode_blocks_per_group;
2982         if (blks_needed < overhead)
2983                 blks_needed = overhead;
2984
2985 #ifdef RESIZE2FS_DEBUG
2986         if (flags & RESIZE_DEBUG_MIN_CALC)
2987                 printf("Estimated blocks needed: %llu\n", blks_needed);
2988 #endif
2989
2990         /*
2991          * If at this point we've already added up more "needed" than
2992          * the current size, just return current size as minimum.
2993          */
2994         if (blks_needed >= ext2fs_blocks_count(fs->super))
2995                 return ext2fs_blocks_count(fs->super);
2996         /*
2997          * We need to reserve a few extra blocks if extents are
2998          * enabled, in case we need to grow the extent tree.  The more
2999          * we shrink the file system, the more space we need.
3000          *
3001          * The absolute worst case is every single data block is in
3002          * the part of the file system that needs to be evacuated,
3003          * with each data block needs to be in its own extent, and
3004          * with each inode needing at least one extent block.
3005          */
3006         if (ext2fs_has_feature_extents(fs->super)) {
3007                 blk64_t safe_margin = (ext2fs_blocks_count(fs->super) -
3008                                        blks_needed)/500;
3009                 unsigned int exts_per_blk = (fs->blocksize /
3010                                              sizeof(struct ext3_extent)) - 1;
3011                 blk64_t worst_case = ((data_needed + exts_per_blk - 1) /
3012                                       exts_per_blk);
3013
3014                 if (worst_case < inode_count)
3015                         worst_case = inode_count;
3016
3017                 if (safe_margin > worst_case)
3018                         safe_margin = worst_case;
3019
3020 #ifdef RESIZE2FS_DEBUG
3021                 if (flags & RESIZE_DEBUG_MIN_CALC)
3022                         printf("Extents safety margin: %llu\n", safe_margin);
3023 #endif
3024                 blks_needed += safe_margin;
3025         }
3026
3027         return blks_needed;
3028 }