resize2fs.c revision 831f309c624d77e41c83ee7c55d900e347cd44fe
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 44static void fix_uninit_block_bitmaps(ext2_filsys fs); 45static errcode_t adjust_superblock(ext2_resize_t rfs, blk64_t new_size); 46static errcode_t blocks_to_move(ext2_resize_t rfs); 47static errcode_t block_mover(ext2_resize_t rfs); 48static errcode_t inode_scan_and_fix(ext2_resize_t rfs); 49static errcode_t inode_ref_fix(ext2_resize_t rfs); 50static errcode_t move_itables(ext2_resize_t rfs); 51static errcode_t fix_resize_inode(ext2_filsys fs); 52static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs); 53static errcode_t fix_sb_journal_backup(ext2_filsys fs); 54 55/* 56 * Some helper CPP macros 57 */ 58#define IS_BLOCK_BM(fs, i, blk) ((blk) == ext2fs_block_bitmap_loc((fs),(i))) 59#define IS_INODE_BM(fs, i, blk) ((blk) == ext2fs_inode_bitmap_loc((fs),(i))) 60 61#define IS_INODE_TB(fs, i, blk) (((blk) >= ext2fs_inode_table_loc((fs), (i))) && \ 62 ((blk) < (ext2fs_inode_table_loc((fs), (i)) + \ 63 (fs)->inode_blocks_per_group))) 64 65int lazy_itable_init; 66 67/* 68 * This is the top-level routine which does the dirty deed.... 69 */ 70errcode_t resize_fs(ext2_filsys fs, blk64_t *new_size, int flags, 71 errcode_t (*progress)(ext2_resize_t rfs, int pass, 72 unsigned long cur, 73 unsigned long max_val)) 74{ 75 ext2_resize_t rfs; 76 errcode_t retval; 77 78 retval = ext2fs_read_bitmaps(fs); 79 if (retval) 80 return retval; 81 82 fs->super->s_state |= EXT2_ERROR_FS; 83 ext2fs_mark_super_dirty(fs); 84 ext2fs_flush(fs); 85 86 /* 87 * Create the data structure 88 */ 89 retval = ext2fs_get_mem(sizeof(struct ext2_resize_struct), &rfs); 90 if (retval) 91 return retval; 92 memset(rfs, 0, sizeof(struct ext2_resize_struct)); 93 94 fix_uninit_block_bitmaps(fs); 95 fs->priv_data = rfs; 96 rfs->old_fs = fs; 97 rfs->flags = flags; 98 rfs->itable_buf = 0; 99 rfs->progress = progress; 100 retval = ext2fs_dup_handle(fs, &rfs->new_fs); 101 if (retval) 102 goto errout; 103 104 retval = adjust_superblock(rfs, *new_size); 105 if (retval) 106 goto errout; 107 108 fix_uninit_block_bitmaps(rfs->new_fs); 109 /* Clear the block bitmap uninit flag for the last block group */ 110 ext2fs_bg_flags_clear(rfs->new_fs, rfs->new_fs->group_desc_count - 1, 111 EXT2_BG_BLOCK_UNINIT); 112 113 *new_size = ext2fs_blocks_count(rfs->new_fs->super); 114 115 retval = blocks_to_move(rfs); 116 if (retval) 117 goto errout; 118 119#ifdef RESIZE2FS_DEBUG 120 if (rfs->flags & RESIZE_DEBUG_BMOVE) 121 printf("Number of free blocks: %llu/%llu, Needed: %llu\n", 122 ext2fs_free_blocks_count(rfs->old_fs->super), 123 ext2fs_free_blocks_count(rfs->new_fs->super), 124 rfs->needed_blocks); 125#endif 126 127 retval = block_mover(rfs); 128 if (retval) 129 goto errout; 130 131 retval = inode_scan_and_fix(rfs); 132 if (retval) 133 goto errout; 134 135 retval = inode_ref_fix(rfs); 136 if (retval) 137 goto errout; 138 139 retval = move_itables(rfs); 140 if (retval) 141 goto errout; 142 143 retval = ext2fs_calculate_summary_stats(rfs->new_fs); 144 if (retval) 145 goto errout; 146 147 retval = fix_resize_inode(rfs->new_fs); 148 if (retval) 149 goto errout; 150 151 retval = fix_sb_journal_backup(rfs->new_fs); 152 if (retval) 153 goto errout; 154 155 rfs->new_fs->super->s_state &= ~EXT2_ERROR_FS; 156 rfs->new_fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY; 157 retval = ext2fs_close(rfs->new_fs); 158 if (retval) 159 goto errout; 160 161 rfs->flags = flags; 162 163 ext2fs_free(rfs->old_fs); 164 if (rfs->itable_buf) 165 ext2fs_free_mem(&rfs->itable_buf); 166 if (rfs->reserve_blocks) 167 ext2fs_free_block_bitmap(rfs->reserve_blocks); 168 if (rfs->move_blocks) 169 ext2fs_free_block_bitmap(rfs->move_blocks); 170 ext2fs_free_mem(&rfs); 171 172 return 0; 173 174errout: 175 if (rfs->new_fs) 176 ext2fs_free(rfs->new_fs); 177 if (rfs->itable_buf) 178 ext2fs_free_mem(&rfs->itable_buf); 179 ext2fs_free_mem(&rfs); 180 return retval; 181} 182 183/* 184 * Clean up the bitmaps for unitialized bitmaps 185 */ 186static void fix_uninit_block_bitmaps(ext2_filsys fs) 187{ 188 blk64_t i, blk, super_blk, old_desc_blk, new_desc_blk; 189 int old_desc_blocks; 190 dgrp_t g; 191 192 if (!(EXT2_HAS_RO_COMPAT_FEATURE(fs->super, 193 EXT4_FEATURE_RO_COMPAT_GDT_CSUM))) 194 return; 195 196 for (g=0; g < fs->group_desc_count; g++) { 197 if (!(ext2fs_bg_flags_test(fs, g, EXT2_BG_BLOCK_UNINIT))) 198 continue; 199 200 blk = (g * fs->super->s_blocks_per_group) + 201 fs->super->s_first_data_block; 202 203 ext2fs_super_and_bgd_loc2(fs, g, &super_blk, 204 &old_desc_blk, &new_desc_blk, 0); 205 206 if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) 207 old_desc_blocks = fs->super->s_first_meta_bg; 208 else 209 old_desc_blocks = fs->desc_blocks + 210 fs->super->s_reserved_gdt_blocks; 211 212 for (i=0; i < fs->super->s_blocks_per_group; i++, blk++) { 213 if (blk >= ext2fs_blocks_count(fs->super)) 214 break; 215 if ((blk == super_blk) || 216 (old_desc_blk && old_desc_blocks && 217 (blk >= old_desc_blk) && 218 (blk < old_desc_blk + old_desc_blocks)) || 219 (new_desc_blk && (blk == new_desc_blk)) || 220 (blk == ext2fs_block_bitmap_loc(fs, g)) || 221 (blk == ext2fs_inode_bitmap_loc(fs, g)) || 222 (blk >= ext2fs_inode_table_loc(fs, g) && 223 (blk < ext2fs_inode_table_loc(fs, g) 224 + fs->inode_blocks_per_group))) 225 ext2fs_fast_mark_block_bitmap2(fs->block_map, blk); 226 else 227 ext2fs_fast_unmark_block_bitmap2(fs->block_map, blk); 228 } 229 } 230} 231 232/* -------------------------------------------------------------------- 233 * 234 * Resize processing, phase 1. 235 * 236 * In this phase we adjust the in-memory superblock information, and 237 * initialize any new parts of the inode table. The new parts of the 238 * inode table are created in virgin disk space, so we can abort here 239 * without any side effects. 240 * -------------------------------------------------------------------- 241 */ 242 243/* 244 * If the group descriptor's bitmap and inode table blocks are valid, 245 * release them in the new filesystem data structure, and mark them as 246 * reserved so the old inode table blocks don't get overwritten. 247 */ 248static void free_gdp_blocks(ext2_filsys fs, 249 ext2fs_block_bitmap reserve_blocks, 250 struct ext2_group_desc *gdp) 251{ 252 blk_t blk; 253 int j; 254 255 if (gdp->bg_block_bitmap && 256 (gdp->bg_block_bitmap < ext2fs_blocks_count(fs->super))) { 257 ext2fs_block_alloc_stats(fs, gdp->bg_block_bitmap, -1); 258 ext2fs_mark_block_bitmap2(reserve_blocks, 259 gdp->bg_block_bitmap); 260 } 261 262 if (gdp->bg_inode_bitmap && 263 (gdp->bg_inode_bitmap < ext2fs_blocks_count(fs->super))) { 264 ext2fs_block_alloc_stats(fs, gdp->bg_inode_bitmap, -1); 265 ext2fs_mark_block_bitmap2(reserve_blocks, 266 gdp->bg_inode_bitmap); 267 } 268 269 if (gdp->bg_inode_table == 0 || 270 (gdp->bg_inode_table >= ext2fs_blocks_count(fs->super))) 271 return; 272 273 for (blk = gdp->bg_inode_table, j = 0; 274 j < fs->inode_blocks_per_group; j++, blk++) { 275 if (blk >= ext2fs_blocks_count(fs->super)) 276 break; 277 ext2fs_block_alloc_stats(fs, blk, -1); 278 ext2fs_mark_block_bitmap2(reserve_blocks, blk); 279 } 280} 281 282/* 283 * This routine is shared by the online and offline resize routines. 284 * All of the information which is adjusted in memory is done here. 285 * 286 * The reserve_blocks parameter is only needed when shrinking the 287 * filesystem. 288 */ 289errcode_t adjust_fs_info(ext2_filsys fs, ext2_filsys old_fs, 290 ext2fs_block_bitmap reserve_blocks, blk64_t new_size) 291{ 292 errcode_t retval; 293 blk64_t overhead = 0; 294 blk64_t rem; 295 blk64_t blk, group_block; 296 blk64_t real_end; 297 blk64_t old_numblocks, numblocks, adjblocks; 298 unsigned long i, j, old_desc_blocks; 299 unsigned int meta_bg, meta_bg_size; 300 int has_super, csum_flag; 301 unsigned long long new_inodes; /* u64 to check for overflow */ 302 double percent; 303 304 ext2fs_blocks_count_set(fs->super, new_size); 305 306retry: 307 fs->group_desc_count = ext2fs_div64_ceil(ext2fs_blocks_count(fs->super) - 308 fs->super->s_first_data_block, 309 EXT2_BLOCKS_PER_GROUP(fs->super)); 310 if (fs->group_desc_count == 0) 311 return EXT2_ET_TOOSMALL; 312 fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count, 313 EXT2_DESC_PER_BLOCK(fs->super)); 314 315 /* 316 * Overhead is the number of bookkeeping blocks per group. It 317 * includes the superblock backup, the group descriptor 318 * backups, the inode bitmap, the block bitmap, and the inode 319 * table. 320 */ 321 overhead = (int) (2 + fs->inode_blocks_per_group); 322 323 if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1)) 324 overhead += 1 + fs->desc_blocks + 325 fs->super->s_reserved_gdt_blocks; 326 327 /* 328 * See if the last group is big enough to support the 329 * necessary data structures. If not, we need to get rid of 330 * it. 331 */ 332 rem = (ext2fs_blocks_count(fs->super) - fs->super->s_first_data_block) % 333 fs->super->s_blocks_per_group; 334 if ((fs->group_desc_count == 1) && rem && (rem < overhead)) 335 return EXT2_ET_TOOSMALL; 336 if ((fs->group_desc_count > 1) && rem && (rem < overhead+50)) { 337 ext2fs_blocks_count_set(fs->super, 338 ext2fs_blocks_count(fs->super) - rem); 339 goto retry; 340 } 341 /* 342 * Adjust the number of inodes 343 */ 344 new_inodes =(unsigned long long) fs->super->s_inodes_per_group * fs->group_desc_count; 345 if (new_inodes > ~0U) { 346 fprintf(stderr, _("inodes (%llu) must be less than %u"), 347 new_inodes, ~0U); 348 return EXT2_ET_TOO_MANY_INODES; 349 } 350 fs->super->s_inodes_count = fs->super->s_inodes_per_group * 351 fs->group_desc_count; 352 353 /* 354 * Adjust the number of free blocks 355 */ 356 blk = ext2fs_blocks_count(old_fs->super); 357 if (blk > ext2fs_blocks_count(fs->super)) 358 ext2fs_free_blocks_count_set(fs->super, 359 ext2fs_free_blocks_count(fs->super) - 360 (blk - ext2fs_blocks_count(fs->super))); 361 else 362 ext2fs_free_blocks_count_set(fs->super, 363 ext2fs_free_blocks_count(fs->super) + 364 (ext2fs_blocks_count(fs->super) - blk)); 365 366 /* 367 * Adjust the number of reserved blocks 368 */ 369 percent = (ext2fs_r_blocks_count(old_fs->super) * 100.0) / 370 ext2fs_blocks_count(old_fs->super); 371 ext2fs_r_blocks_count_set(fs->super, 372 (percent * ext2fs_blocks_count(fs->super) / 373 100.0)); 374 375 /* 376 * Adjust the bitmaps for size 377 */ 378 retval = ext2fs_resize_inode_bitmap2(fs->super->s_inodes_count, 379 fs->super->s_inodes_count, 380 fs->inode_map); 381 if (retval) goto errout; 382 383 real_end = (((blk64_t) EXT2_BLOCKS_PER_GROUP(fs->super) * 384 fs->group_desc_count)) - 1 + 385 fs->super->s_first_data_block; 386 retval = ext2fs_resize_block_bitmap2(ext2fs_blocks_count(fs->super)-1, 387 real_end, fs->block_map); 388 389 if (retval) goto errout; 390 391 /* 392 * Reallocate the group descriptors as necessary. 393 */ 394 if (old_fs->desc_blocks != fs->desc_blocks) { 395 retval = ext2fs_resize_mem(old_fs->desc_blocks * 396 fs->blocksize, 397 fs->desc_blocks * fs->blocksize, 398 &fs->group_desc); 399 if (retval) 400 goto errout; 401 if (fs->desc_blocks > old_fs->desc_blocks) 402 memset((char *) fs->group_desc + 403 (old_fs->desc_blocks * fs->blocksize), 0, 404 (fs->desc_blocks - old_fs->desc_blocks) * 405 fs->blocksize); 406 } 407 408 /* 409 * If the resize_inode feature is set, and we are changing the 410 * number of descriptor blocks, then adjust 411 * s_reserved_gdt_blocks if possible to avoid needing to move 412 * the inode table either now or in the future. 413 */ 414 if ((fs->super->s_feature_compat & 415 EXT2_FEATURE_COMPAT_RESIZE_INODE) && 416 (old_fs->desc_blocks != fs->desc_blocks)) { 417 int new; 418 419 new = ((int) fs->super->s_reserved_gdt_blocks) + 420 (old_fs->desc_blocks - fs->desc_blocks); 421 if (new < 0) 422 new = 0; 423 if (new > (int) fs->blocksize/4) 424 new = fs->blocksize/4; 425 fs->super->s_reserved_gdt_blocks = new; 426 } 427 428 /* 429 * If we are shrinking the number of block groups, we're done 430 * and can exit now. 431 */ 432 if (old_fs->group_desc_count > fs->group_desc_count) { 433 /* 434 * Check the block groups that we are chopping off 435 * and free any blocks associated with their metadata 436 */ 437 for (i = fs->group_desc_count; 438 i < old_fs->group_desc_count; i++) { 439 free_gdp_blocks(fs, reserve_blocks, 440 ext2fs_group_desc(old_fs, 441 old_fs->group_desc, i)); 442 } 443 retval = 0; 444 goto errout; 445 } 446 447 /* 448 * Fix the count of the last (old) block group 449 */ 450 old_numblocks = (ext2fs_blocks_count(old_fs->super) - 451 old_fs->super->s_first_data_block) % 452 old_fs->super->s_blocks_per_group; 453 if (!old_numblocks) 454 old_numblocks = old_fs->super->s_blocks_per_group; 455 if (old_fs->group_desc_count == fs->group_desc_count) { 456 numblocks = (ext2fs_blocks_count(fs->super) - 457 fs->super->s_first_data_block) % 458 fs->super->s_blocks_per_group; 459 if (!numblocks) 460 numblocks = fs->super->s_blocks_per_group; 461 } else 462 numblocks = fs->super->s_blocks_per_group; 463 i = old_fs->group_desc_count - 1; 464 ext2fs_bg_free_blocks_count_set(fs, i, ext2fs_bg_free_blocks_count(fs, i) + (numblocks - old_numblocks)); 465 ext2fs_group_desc_csum_set(fs, i); 466 467 /* 468 * If the number of block groups is staying the same, we're 469 * done and can exit now. (If the number block groups is 470 * shrinking, we had exited earlier.) 471 */ 472 if (old_fs->group_desc_count >= fs->group_desc_count) { 473 retval = 0; 474 goto errout; 475 } 476 477 /* 478 * Initialize the new block group descriptors 479 */ 480 group_block = fs->super->s_first_data_block + 481 old_fs->group_desc_count * fs->super->s_blocks_per_group; 482 483 csum_flag = EXT2_HAS_RO_COMPAT_FEATURE(fs->super, 484 EXT4_FEATURE_RO_COMPAT_GDT_CSUM); 485 if (access("/sys/fs/ext4/features/lazy_itable_init", F_OK) == 0) 486 lazy_itable_init = 1; 487 if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) 488 old_desc_blocks = fs->super->s_first_meta_bg; 489 else 490 old_desc_blocks = fs->desc_blocks + 491 fs->super->s_reserved_gdt_blocks; 492 for (i = old_fs->group_desc_count; 493 i < fs->group_desc_count; i++) { 494 memset(ext2fs_group_desc(fs, fs->group_desc, i), 0, 495 sizeof(struct ext2_group_desc)); 496 adjblocks = 0; 497 498 ext2fs_bg_flags_zap(fs, i); 499 if (csum_flag) { 500 ext2fs_bg_flags_set(fs, i, EXT2_BG_INODE_UNINIT); 501 if (!lazy_itable_init) 502 ext2fs_bg_flags_set(fs, i, 503 EXT2_BG_INODE_ZEROED); 504 ext2fs_bg_itable_unused_set(fs, i, 505 fs->super->s_inodes_per_group); 506 } 507 508 numblocks = ext2fs_group_blocks_count(fs, i); 509 if ((i < fs->group_desc_count - 1) && csum_flag) 510 ext2fs_bg_flags_set(fs, i, EXT2_BG_BLOCK_UNINIT); 511 512 has_super = ext2fs_bg_has_super(fs, i); 513 if (has_super) { 514 ext2fs_block_alloc_stats2(fs, group_block, +1); 515 adjblocks++; 516 } 517 meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super); 518 meta_bg = i / meta_bg_size; 519 if (!(fs->super->s_feature_incompat & 520 EXT2_FEATURE_INCOMPAT_META_BG) || 521 (meta_bg < fs->super->s_first_meta_bg)) { 522 if (has_super) { 523 for (j=0; j < old_desc_blocks; j++) 524 ext2fs_block_alloc_stats2(fs, 525 group_block + 1 + j, +1); 526 adjblocks += old_desc_blocks; 527 } 528 } else { 529 if (has_super) 530 has_super = 1; 531 if (((i % meta_bg_size) == 0) || 532 ((i % meta_bg_size) == 1) || 533 ((i % meta_bg_size) == (meta_bg_size-1))) 534 ext2fs_block_alloc_stats2(fs, 535 group_block + has_super, +1); 536 } 537 538 adjblocks += 2 + fs->inode_blocks_per_group; 539 540 numblocks -= adjblocks; 541 ext2fs_free_blocks_count_set(fs->super, 542 ext2fs_free_blocks_count(fs->super) - adjblocks); 543 fs->super->s_free_inodes_count += 544 fs->super->s_inodes_per_group; 545 ext2fs_bg_free_blocks_count_set(fs, i, numblocks); 546 ext2fs_bg_free_inodes_count_set(fs, i, 547 fs->super->s_inodes_per_group); 548 ext2fs_bg_used_dirs_count_set(fs, i, 0); 549 ext2fs_group_desc_csum_set(fs, i); 550 551 retval = ext2fs_allocate_group_table(fs, i, 0); 552 if (retval) goto errout; 553 554 group_block += fs->super->s_blocks_per_group; 555 } 556 retval = 0; 557 558errout: 559 return (retval); 560} 561 562/* 563 * This routine adjusts the superblock and other data structures, both 564 * in disk as well as in memory... 565 */ 566static errcode_t adjust_superblock(ext2_resize_t rfs, blk64_t new_size) 567{ 568 ext2_filsys fs; 569 int adj = 0; 570 errcode_t retval; 571 blk64_t group_block; 572 unsigned long i; 573 unsigned long max_group; 574 575 fs = rfs->new_fs; 576 ext2fs_mark_super_dirty(fs); 577 ext2fs_mark_bb_dirty(fs); 578 ext2fs_mark_ib_dirty(fs); 579 580 retval = ext2fs_allocate_block_bitmap(fs, _("reserved blocks"), 581 &rfs->reserve_blocks); 582 if (retval) 583 return retval; 584 585 retval = adjust_fs_info(fs, rfs->old_fs, rfs->reserve_blocks, new_size); 586 if (retval) 587 goto errout; 588 589 /* 590 * Check to make sure there are enough inodes 591 */ 592 if ((rfs->old_fs->super->s_inodes_count - 593 rfs->old_fs->super->s_free_inodes_count) > 594 rfs->new_fs->super->s_inodes_count) { 595 retval = ENOSPC; 596 goto errout; 597 } 598 599 /* 600 * If we are shrinking the number block groups, we're done and 601 * can exit now. 602 */ 603 if (rfs->old_fs->group_desc_count > fs->group_desc_count) { 604 retval = 0; 605 goto errout; 606 } 607 608 /* 609 * If the number of block groups is staying the same, we're 610 * done and can exit now. (If the number block groups is 611 * shrinking, we had exited earlier.) 612 */ 613 if (rfs->old_fs->group_desc_count >= fs->group_desc_count) { 614 retval = 0; 615 goto errout; 616 } 617 618 /* 619 * If we are using uninit_bg (aka GDT_CSUM) and the kernel 620 * supports lazy inode initialization, we can skip 621 * initializing the inode table. 622 */ 623 if (lazy_itable_init && 624 EXT2_HAS_RO_COMPAT_FEATURE(fs->super, 625 EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) { 626 retval = 0; 627 goto errout; 628 } 629 630 /* 631 * Initialize the inode table 632 */ 633 retval = ext2fs_get_array(fs->blocksize, fs->inode_blocks_per_group, 634 &rfs->itable_buf); 635 if (retval) 636 goto errout; 637 638 memset(rfs->itable_buf, 0, fs->blocksize * fs->inode_blocks_per_group); 639 group_block = fs->super->s_first_data_block + 640 rfs->old_fs->group_desc_count * fs->super->s_blocks_per_group; 641 642 adj = rfs->old_fs->group_desc_count; 643 max_group = fs->group_desc_count - adj; 644 if (rfs->progress) { 645 retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS, 646 0, max_group); 647 if (retval) 648 goto errout; 649 } 650 for (i = rfs->old_fs->group_desc_count; 651 i < fs->group_desc_count; i++) { 652 /* 653 * Write out the new inode table 654 */ 655 retval = io_channel_write_blk64(fs->io, 656 ext2fs_inode_table_loc(fs, i), 657 fs->inode_blocks_per_group, 658 rfs->itable_buf); 659 if (retval) goto errout; 660 661 io_channel_flush(fs->io); 662 if (rfs->progress) { 663 retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS, 664 i - adj + 1, max_group); 665 if (retval) 666 goto errout; 667 } 668 group_block += fs->super->s_blocks_per_group; 669 } 670 io_channel_flush(fs->io); 671 retval = 0; 672 673errout: 674 return retval; 675} 676 677/* -------------------------------------------------------------------- 678 * 679 * Resize processing, phase 2. 680 * 681 * In this phase we adjust determine which blocks need to be moved, in 682 * blocks_to_move(). We then copy the blocks to their ultimate new 683 * destinations using block_mover(). Since we are copying blocks to 684 * their new locations, again during this pass we can abort without 685 * any problems. 686 * -------------------------------------------------------------------- 687 */ 688 689/* 690 * This helper function creates a block bitmap with all of the 691 * filesystem meta-data blocks. 692 */ 693static errcode_t mark_table_blocks(ext2_filsys fs, 694 ext2fs_block_bitmap bmap) 695{ 696 blk64_t b; 697 unsigned int j; 698 dgrp_t i; 699 700 for (i = 0; i < fs->group_desc_count; i++) { 701 ext2fs_reserve_super_and_bgd(fs, i, bmap); 702 703 /* 704 * Mark the blocks used for the inode table 705 */ 706 for (j = 0, b = ext2fs_inode_table_loc(fs, i); 707 j < (unsigned int) fs->inode_blocks_per_group; 708 j++, b++) 709 ext2fs_mark_block_bitmap2(bmap, b); 710 711 /* 712 * Mark block used for the block bitmap 713 */ 714 ext2fs_mark_block_bitmap2(bmap, 715 ext2fs_block_bitmap_loc(fs, i)); 716 717 /* 718 * Mark block used for the inode bitmap 719 */ 720 ext2fs_mark_block_bitmap2(bmap, 721 ext2fs_inode_bitmap_loc(fs, i)); 722 } 723 return 0; 724} 725 726/* 727 * This function checks to see if a particular block (either a 728 * superblock or a block group descriptor) overlaps with an inode or 729 * block bitmap block, or with the inode table. 730 */ 731static void mark_fs_metablock(ext2_resize_t rfs, 732 ext2fs_block_bitmap meta_bmap, 733 int group, blk64_t blk) 734{ 735 ext2_filsys fs = rfs->new_fs; 736 737 ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk); 738 ext2fs_block_alloc_stats2(fs, blk, +1); 739 740 /* 741 * Check to see if we overlap with the inode or block bitmap, 742 * or the inode tables. If not, and the block is in use, then 743 * mark it as a block to be moved. 744 */ 745 if (IS_BLOCK_BM(fs, group, blk)) { 746 ext2fs_block_bitmap_loc_set(fs, group, 0); 747 rfs->needed_blocks++; 748 return; 749 } 750 if (IS_INODE_BM(fs, group, blk)) { 751 ext2fs_inode_bitmap_loc_set(fs, group, 0); 752 rfs->needed_blocks++; 753 return; 754 } 755 if (IS_INODE_TB(fs, group, blk)) { 756 ext2fs_inode_table_loc_set(fs, group, 0); 757 rfs->needed_blocks++; 758 return; 759 } 760 if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_FLEX_BG) { 761 dgrp_t i; 762 763 for (i=0; i < rfs->old_fs->group_desc_count; i++) { 764 if (IS_BLOCK_BM(fs, i, blk)) { 765 ext2fs_block_bitmap_loc_set(fs, i, 0); 766 rfs->needed_blocks++; 767 return; 768 } 769 if (IS_INODE_BM(fs, i, blk)) { 770 ext2fs_inode_bitmap_loc_set(fs, i, 0); 771 rfs->needed_blocks++; 772 return; 773 } 774 if (IS_INODE_TB(fs, i, blk)) { 775 ext2fs_inode_table_loc_set(fs, i, 0); 776 rfs->needed_blocks++; 777 return; 778 } 779 } 780 } 781 if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super, 782 EXT4_FEATURE_RO_COMPAT_GDT_CSUM) && 783 (ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT))) { 784 /* 785 * If the block bitmap is uninitialized, which means 786 * nothing other than standard metadata in use. 787 */ 788 return; 789 } else if (ext2fs_test_block_bitmap2(rfs->old_fs->block_map, blk) && 790 !ext2fs_test_block_bitmap2(meta_bmap, blk)) { 791 ext2fs_mark_block_bitmap2(rfs->move_blocks, blk); 792 rfs->needed_blocks++; 793 } 794} 795 796 797/* 798 * This routine marks and unmarks reserved blocks in the new block 799 * bitmap. It also determines which blocks need to be moved and 800 * places this information into the move_blocks bitmap. 801 */ 802static errcode_t blocks_to_move(ext2_resize_t rfs) 803{ 804 int j, has_super; 805 dgrp_t i, max_groups, g; 806 blk64_t blk, group_blk; 807 blk64_t old_blocks, new_blocks; 808 unsigned int meta_bg, meta_bg_size; 809 errcode_t retval; 810 ext2_filsys fs, old_fs; 811 ext2fs_block_bitmap meta_bmap; 812 int flex_bg; 813 814 fs = rfs->new_fs; 815 old_fs = rfs->old_fs; 816 if (ext2fs_blocks_count(old_fs->super) > ext2fs_blocks_count(fs->super)) 817 fs = rfs->old_fs; 818 819 retval = ext2fs_allocate_block_bitmap(fs, _("blocks to be moved"), 820 &rfs->move_blocks); 821 if (retval) 822 return retval; 823 824 retval = ext2fs_allocate_block_bitmap(fs, _("meta-data blocks"), 825 &meta_bmap); 826 if (retval) 827 return retval; 828 829 retval = mark_table_blocks(old_fs, meta_bmap); 830 if (retval) 831 return retval; 832 833 fs = rfs->new_fs; 834 835 /* 836 * If we're shrinking the filesystem, we need to move all of 837 * the blocks that don't fit any more 838 */ 839 for (blk = ext2fs_blocks_count(fs->super); 840 blk < ext2fs_blocks_count(old_fs->super); blk++) { 841 g = ext2fs_group_of_blk2(fs, blk); 842 if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super, 843 EXT4_FEATURE_RO_COMPAT_GDT_CSUM) && 844 ext2fs_bg_flags_test(old_fs, g, EXT2_BG_BLOCK_UNINIT)) { 845 /* 846 * The block bitmap is uninitialized, so skip 847 * to the next block group. 848 */ 849 blk = ((g+1) * fs->super->s_blocks_per_group) + 850 fs->super->s_first_data_block - 1; 851 continue; 852 } 853 if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) && 854 !ext2fs_test_block_bitmap2(meta_bmap, blk)) { 855 ext2fs_mark_block_bitmap2(rfs->move_blocks, blk); 856 rfs->needed_blocks++; 857 } 858 ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk); 859 } 860 861 if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) { 862 old_blocks = old_fs->super->s_first_meta_bg; 863 new_blocks = fs->super->s_first_meta_bg; 864 } else { 865 old_blocks = old_fs->desc_blocks + old_fs->super->s_reserved_gdt_blocks; 866 new_blocks = fs->desc_blocks + fs->super->s_reserved_gdt_blocks; 867 } 868 869 if (old_blocks == new_blocks) { 870 retval = 0; 871 goto errout; 872 } 873 874 max_groups = fs->group_desc_count; 875 if (max_groups > old_fs->group_desc_count) 876 max_groups = old_fs->group_desc_count; 877 group_blk = old_fs->super->s_first_data_block; 878 /* 879 * If we're reducing the number of descriptor blocks, this 880 * makes life easy. :-) We just have to mark some extra 881 * blocks as free. 882 */ 883 if (old_blocks > new_blocks) { 884 for (i = 0; i < max_groups; i++) { 885 if (!ext2fs_bg_has_super(fs, i)) { 886 group_blk += fs->super->s_blocks_per_group; 887 continue; 888 } 889 for (blk = group_blk+1+new_blocks; 890 blk < group_blk+1+old_blocks; blk++) { 891 ext2fs_block_alloc_stats2(fs, blk, -1); 892 rfs->needed_blocks--; 893 } 894 group_blk += fs->super->s_blocks_per_group; 895 } 896 retval = 0; 897 goto errout; 898 } 899 /* 900 * If we're increasing the number of descriptor blocks, life 901 * gets interesting.... 902 */ 903 meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super); 904 flex_bg = fs->super->s_feature_incompat & 905 EXT4_FEATURE_INCOMPAT_FLEX_BG; 906 /* first reserve all of the existing fs meta blocks */ 907 for (i = 0; i < max_groups; i++) { 908 has_super = ext2fs_bg_has_super(fs, i); 909 if (has_super) 910 mark_fs_metablock(rfs, meta_bmap, i, group_blk); 911 912 meta_bg = i / meta_bg_size; 913 if (!(fs->super->s_feature_incompat & 914 EXT2_FEATURE_INCOMPAT_META_BG) || 915 (meta_bg < fs->super->s_first_meta_bg)) { 916 if (has_super) { 917 for (blk = group_blk+1; 918 blk < group_blk + 1 + new_blocks; blk++) 919 mark_fs_metablock(rfs, meta_bmap, 920 i, blk); 921 } 922 } else { 923 if (has_super) 924 has_super = 1; 925 if (((i % meta_bg_size) == 0) || 926 ((i % meta_bg_size) == 1) || 927 ((i % meta_bg_size) == (meta_bg_size-1))) 928 mark_fs_metablock(rfs, meta_bmap, i, 929 group_blk + has_super); 930 } 931 932 /* 933 * Reserve the existing meta blocks that we know 934 * aren't to be moved. 935 * 936 * For flex_bg file systems, in order to avoid 937 * overwriting fs metadata (especially inode table 938 * blocks) belonging to a different block group when 939 * we are relocating the inode tables, we need to 940 * reserve all existing fs metadata blocks. 941 */ 942 if (ext2fs_block_bitmap_loc(fs, i)) 943 ext2fs_mark_block_bitmap2(rfs->reserve_blocks, 944 ext2fs_block_bitmap_loc(fs, i)); 945 else if (flex_bg && i < old_fs->group_desc_count) 946 ext2fs_mark_block_bitmap2(rfs->reserve_blocks, 947 ext2fs_block_bitmap_loc(old_fs, i)); 948 949 if (ext2fs_inode_bitmap_loc(fs, i)) 950 ext2fs_mark_block_bitmap2(rfs->reserve_blocks, 951 ext2fs_inode_bitmap_loc(fs, i)); 952 else if (flex_bg && i < old_fs->group_desc_count) 953 ext2fs_mark_block_bitmap2(rfs->reserve_blocks, 954 ext2fs_inode_bitmap_loc(old_fs, i)); 955 956 if (ext2fs_inode_table_loc(fs, i)) 957 for (blk = ext2fs_inode_table_loc(fs, i), j=0; 958 j < fs->inode_blocks_per_group ; j++, blk++) 959 ext2fs_mark_block_bitmap2(rfs->reserve_blocks, 960 blk); 961 else if (flex_bg && i < old_fs->group_desc_count) 962 for (blk = ext2fs_inode_table_loc(old_fs, i), j=0; 963 j < old_fs->inode_blocks_per_group ; j++, blk++) 964 ext2fs_mark_block_bitmap2(rfs->reserve_blocks, 965 blk); 966 967 group_blk += rfs->new_fs->super->s_blocks_per_group; 968 } 969 970 /* Allocate the missing data structures */ 971 for (i = 0; i < max_groups; i++) { 972 if (ext2fs_inode_table_loc(fs, i) && 973 ext2fs_inode_bitmap_loc(fs, i) && 974 ext2fs_block_bitmap_loc(fs, i)) 975 continue; 976 977 retval = ext2fs_allocate_group_table(fs, i, 978 rfs->reserve_blocks); 979 if (retval) 980 goto errout; 981 982 /* 983 * For those structures that have changed, we need to 984 * do bookkeepping. 985 */ 986 if (ext2fs_block_bitmap_loc(old_fs, i) != 987 (blk = ext2fs_block_bitmap_loc(fs, i))) { 988 ext2fs_block_alloc_stats2(fs, blk, +1); 989 if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) && 990 !ext2fs_test_block_bitmap2(meta_bmap, blk)) 991 ext2fs_mark_block_bitmap2(rfs->move_blocks, 992 blk); 993 } 994 if (ext2fs_inode_bitmap_loc(old_fs, i) != 995 (blk = ext2fs_inode_bitmap_loc(fs, i))) { 996 ext2fs_block_alloc_stats2(fs, blk, +1); 997 if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) && 998 !ext2fs_test_block_bitmap2(meta_bmap, blk)) 999 ext2fs_mark_block_bitmap2(rfs->move_blocks, 1000 blk); 1001 } 1002 1003 /* 1004 * The inode table, if we need to relocate it, is 1005 * handled specially. We have to reserve the blocks 1006 * for both the old and the new inode table, since we 1007 * can't have the inode table be destroyed during the 1008 * block relocation phase. 1009 */ 1010 if (ext2fs_inode_table_loc(fs, i) == ext2fs_inode_table_loc(old_fs, i)) 1011 continue; /* inode table not moved */ 1012 1013 rfs->needed_blocks += fs->inode_blocks_per_group; 1014 1015 /* 1016 * Mark the new inode table as in use in the new block 1017 * allocation bitmap, and move any blocks that might 1018 * be necessary. 1019 */ 1020 for (blk = ext2fs_inode_table_loc(fs, i), j=0; 1021 j < fs->inode_blocks_per_group ; j++, blk++) { 1022 ext2fs_block_alloc_stats2(fs, blk, +1); 1023 if (ext2fs_test_block_bitmap2(old_fs->block_map, blk) && 1024 !ext2fs_test_block_bitmap2(meta_bmap, blk)) 1025 ext2fs_mark_block_bitmap2(rfs->move_blocks, 1026 blk); 1027 } 1028 1029 /* 1030 * Make sure the old inode table is reserved in the 1031 * block reservation bitmap. 1032 */ 1033 for (blk = ext2fs_inode_table_loc(rfs->old_fs, i), j=0; 1034 j < fs->inode_blocks_per_group ; j++, blk++) 1035 ext2fs_mark_block_bitmap2(rfs->reserve_blocks, blk); 1036 } 1037 retval = 0; 1038 1039errout: 1040 if (meta_bmap) 1041 ext2fs_free_block_bitmap(meta_bmap); 1042 1043 return retval; 1044} 1045 1046/* 1047 * This helper function tries to allocate a new block. We try to 1048 * avoid hitting the original group descriptor blocks at least at 1049 * first, since we want to make it possible to recover from a badly 1050 * aborted resize operation as much as possible. 1051 * 1052 * In the future, I may further modify this routine to balance out 1053 * where we get the new blocks across the various block groups. 1054 * Ideally we would allocate blocks that corresponded with the block 1055 * group of the containing inode, and keep contiguous blocks 1056 * together. However, this very difficult to do efficiently, since we 1057 * don't have the necessary information up front. 1058 */ 1059 1060#define AVOID_OLD 1 1061#define DESPERATION 2 1062 1063static void init_block_alloc(ext2_resize_t rfs) 1064{ 1065 rfs->alloc_state = AVOID_OLD; 1066 rfs->new_blk = rfs->new_fs->super->s_first_data_block; 1067#if 0 1068 /* HACK for testing */ 1069 if (ext2fs_blocks_count(rfs->new_fs->super) > 1070 ext2fs_blocks_count(rfs->old_fs->super)) 1071 rfs->new_blk = ext2fs_blocks_count(rfs->old_fs->super); 1072#endif 1073} 1074 1075static blk64_t get_new_block(ext2_resize_t rfs) 1076{ 1077 ext2_filsys fs = rfs->new_fs; 1078 1079 while (1) { 1080 if (rfs->new_blk >= ext2fs_blocks_count(fs->super)) { 1081 if (rfs->alloc_state == DESPERATION) 1082 return 0; 1083 1084#ifdef RESIZE2FS_DEBUG 1085 if (rfs->flags & RESIZE_DEBUG_BMOVE) 1086 printf("Going into desperation mode " 1087 "for block allocations\n"); 1088#endif 1089 rfs->alloc_state = DESPERATION; 1090 rfs->new_blk = fs->super->s_first_data_block; 1091 continue; 1092 } 1093 if (ext2fs_test_block_bitmap2(fs->block_map, rfs->new_blk) || 1094 ext2fs_test_block_bitmap2(rfs->reserve_blocks, 1095 rfs->new_blk) || 1096 ((rfs->alloc_state == AVOID_OLD) && 1097 (rfs->new_blk < ext2fs_blocks_count(rfs->old_fs->super)) && 1098 ext2fs_test_block_bitmap2(rfs->old_fs->block_map, 1099 rfs->new_blk))) { 1100 rfs->new_blk++; 1101 continue; 1102 } 1103 return rfs->new_blk; 1104 } 1105} 1106 1107static errcode_t resize2fs_get_alloc_block(ext2_filsys fs, blk64_t goal, 1108 blk64_t *ret) 1109{ 1110 ext2_resize_t rfs = (ext2_resize_t) fs->priv_data; 1111 blk64_t blk; 1112 1113 blk = get_new_block(rfs); 1114 if (!blk) 1115 return ENOSPC; 1116 1117#ifdef RESIZE2FS_DEBUG 1118 if (rfs->flags & 0xF) 1119 printf("get_alloc_block allocating %llu\n", blk); 1120#endif 1121 1122 ext2fs_mark_block_bitmap2(rfs->old_fs->block_map, blk); 1123 ext2fs_mark_block_bitmap2(rfs->new_fs->block_map, blk); 1124 *ret = (blk64_t) blk; 1125 return 0; 1126} 1127 1128static errcode_t block_mover(ext2_resize_t rfs) 1129{ 1130 blk64_t blk, old_blk, new_blk; 1131 ext2_filsys fs = rfs->new_fs; 1132 ext2_filsys old_fs = rfs->old_fs; 1133 errcode_t retval; 1134 __u64 size; 1135 int c; 1136 int to_move, moved; 1137 ext2_badblocks_list badblock_list = 0; 1138 int bb_modified = 0; 1139 1140 fs->get_alloc_block = resize2fs_get_alloc_block; 1141 old_fs->get_alloc_block = resize2fs_get_alloc_block; 1142 1143 retval = ext2fs_read_bb_inode(old_fs, &badblock_list); 1144 if (retval) 1145 return retval; 1146 1147 new_blk = fs->super->s_first_data_block; 1148 if (!rfs->itable_buf) { 1149 retval = ext2fs_get_array(fs->blocksize, 1150 fs->inode_blocks_per_group, 1151 &rfs->itable_buf); 1152 if (retval) 1153 return retval; 1154 } 1155 retval = ext2fs_create_extent_table(&rfs->bmap, 0); 1156 if (retval) 1157 return retval; 1158 1159 /* 1160 * The first step is to figure out where all of the blocks 1161 * will go. 1162 */ 1163 to_move = moved = 0; 1164 init_block_alloc(rfs); 1165 for (blk = old_fs->super->s_first_data_block; 1166 blk < ext2fs_blocks_count(old_fs->super); blk++) { 1167 if (!ext2fs_test_block_bitmap2(old_fs->block_map, blk)) 1168 continue; 1169 if (!ext2fs_test_block_bitmap2(rfs->move_blocks, blk)) 1170 continue; 1171 if (ext2fs_badblocks_list_test(badblock_list, blk)) { 1172 ext2fs_badblocks_list_del(badblock_list, blk); 1173 bb_modified++; 1174 continue; 1175 } 1176 1177 new_blk = get_new_block(rfs); 1178 if (!new_blk) { 1179 retval = ENOSPC; 1180 goto errout; 1181 } 1182 ext2fs_block_alloc_stats2(fs, new_blk, +1); 1183 ext2fs_add_extent_entry(rfs->bmap, blk, new_blk); 1184 to_move++; 1185 } 1186 1187 if (to_move == 0) { 1188 if (rfs->bmap) { 1189 ext2fs_free_extent_table(rfs->bmap); 1190 rfs->bmap = 0; 1191 } 1192 retval = 0; 1193 goto errout; 1194 } 1195 1196 /* 1197 * Step two is to actually move the blocks 1198 */ 1199 retval = ext2fs_iterate_extent(rfs->bmap, 0, 0, 0); 1200 if (retval) goto errout; 1201 1202 if (rfs->progress) { 1203 retval = (rfs->progress)(rfs, E2_RSZ_BLOCK_RELOC_PASS, 1204 0, to_move); 1205 if (retval) 1206 goto errout; 1207 } 1208 while (1) { 1209 retval = ext2fs_iterate_extent(rfs->bmap, &old_blk, &new_blk, &size); 1210 if (retval) goto errout; 1211 if (!size) 1212 break; 1213#ifdef RESIZE2FS_DEBUG 1214 if (rfs->flags & RESIZE_DEBUG_BMOVE) 1215 printf("Moving %llu blocks %llu->%llu\n", 1216 size, old_blk, new_blk); 1217#endif 1218 do { 1219 c = size; 1220 if (c > fs->inode_blocks_per_group) 1221 c = fs->inode_blocks_per_group; 1222 retval = io_channel_read_blk64(fs->io, old_blk, c, 1223 rfs->itable_buf); 1224 if (retval) goto errout; 1225 retval = io_channel_write_blk64(fs->io, new_blk, c, 1226 rfs->itable_buf); 1227 if (retval) goto errout; 1228 size -= c; 1229 new_blk += c; 1230 old_blk += c; 1231 moved += c; 1232 if (rfs->progress) { 1233 io_channel_flush(fs->io); 1234 retval = (rfs->progress)(rfs, 1235 E2_RSZ_BLOCK_RELOC_PASS, 1236 moved, to_move); 1237 if (retval) 1238 goto errout; 1239 } 1240 } while (size > 0); 1241 io_channel_flush(fs->io); 1242 } 1243 1244errout: 1245 if (badblock_list) { 1246 if (!retval && bb_modified) 1247 retval = ext2fs_update_bb_inode(old_fs, 1248 badblock_list); 1249 ext2fs_badblocks_list_free(badblock_list); 1250 } 1251 return retval; 1252} 1253 1254 1255/* -------------------------------------------------------------------- 1256 * 1257 * Resize processing, phase 3 1258 * 1259 * -------------------------------------------------------------------- 1260 */ 1261 1262 1263struct process_block_struct { 1264 ext2_resize_t rfs; 1265 ext2_ino_t ino; 1266 struct ext2_inode * inode; 1267 errcode_t error; 1268 int is_dir; 1269 int changed; 1270}; 1271 1272static int process_block(ext2_filsys fs, blk64_t *block_nr, 1273 e2_blkcnt_t blockcnt, 1274 blk64_t ref_block EXT2FS_ATTR((unused)), 1275 int ref_offset EXT2FS_ATTR((unused)), void *priv_data) 1276{ 1277 struct process_block_struct *pb; 1278 errcode_t retval; 1279 blk64_t block, new_block; 1280 int ret = 0; 1281 1282 pb = (struct process_block_struct *) priv_data; 1283 block = *block_nr; 1284 if (pb->rfs->bmap) { 1285 new_block = ext2fs_extent_translate(pb->rfs->bmap, block); 1286 if (new_block) { 1287 *block_nr = new_block; 1288 ret |= BLOCK_CHANGED; 1289 pb->changed = 1; 1290#ifdef RESIZE2FS_DEBUG 1291 if (pb->rfs->flags & RESIZE_DEBUG_BMOVE) 1292 printf("ino=%u, blockcnt=%lld, %llu->%llu\n", 1293 pb->ino, blockcnt, block, new_block); 1294#endif 1295 block = new_block; 1296 } 1297 } 1298 if (pb->is_dir) { 1299 retval = ext2fs_add_dir_block2(fs->dblist, pb->ino, 1300 block, (int) blockcnt); 1301 if (retval) { 1302 pb->error = retval; 1303 ret |= BLOCK_ABORT; 1304 } 1305 } 1306 return ret; 1307} 1308 1309/* 1310 * Progress callback 1311 */ 1312static errcode_t progress_callback(ext2_filsys fs, 1313 ext2_inode_scan scan EXT2FS_ATTR((unused)), 1314 dgrp_t group, void * priv_data) 1315{ 1316 ext2_resize_t rfs = (ext2_resize_t) priv_data; 1317 errcode_t retval; 1318 1319 /* 1320 * This check is to protect against old ext2 libraries. It 1321 * shouldn't be needed against new libraries. 1322 */ 1323 if ((group+1) == 0) 1324 return 0; 1325 1326 if (rfs->progress) { 1327 io_channel_flush(fs->io); 1328 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS, 1329 group+1, fs->group_desc_count); 1330 if (retval) 1331 return retval; 1332 } 1333 1334 return 0; 1335} 1336 1337static errcode_t inode_scan_and_fix(ext2_resize_t rfs) 1338{ 1339 struct process_block_struct pb; 1340 ext2_ino_t ino, new_inode; 1341 struct ext2_inode *inode = NULL; 1342 ext2_inode_scan scan = NULL; 1343 errcode_t retval; 1344 char *block_buf = 0; 1345 ext2_ino_t start_to_move; 1346 blk64_t orig_size; 1347 blk64_t new_block; 1348 int inode_size; 1349 1350 if ((rfs->old_fs->group_desc_count <= 1351 rfs->new_fs->group_desc_count) && 1352 !rfs->bmap) 1353 return 0; 1354 1355 /* 1356 * Save the original size of the old filesystem, and 1357 * temporarily set the size to be the new size if the new size 1358 * is larger. We need to do this to avoid catching an error 1359 * by the block iterator routines 1360 */ 1361 orig_size = ext2fs_blocks_count(rfs->old_fs->super); 1362 if (orig_size < ext2fs_blocks_count(rfs->new_fs->super)) 1363 ext2fs_blocks_count_set(rfs->old_fs->super, 1364 ext2fs_blocks_count(rfs->new_fs->super)); 1365 1366 retval = ext2fs_open_inode_scan(rfs->old_fs, 0, &scan); 1367 if (retval) goto errout; 1368 1369 retval = ext2fs_init_dblist(rfs->old_fs, 0); 1370 if (retval) goto errout; 1371 retval = ext2fs_get_array(rfs->old_fs->blocksize, 3, &block_buf); 1372 if (retval) goto errout; 1373 1374 start_to_move = (rfs->new_fs->group_desc_count * 1375 rfs->new_fs->super->s_inodes_per_group); 1376 1377 if (rfs->progress) { 1378 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS, 1379 0, rfs->old_fs->group_desc_count); 1380 if (retval) 1381 goto errout; 1382 } 1383 ext2fs_set_inode_callback(scan, progress_callback, (void *) rfs); 1384 pb.rfs = rfs; 1385 pb.inode = inode; 1386 pb.error = 0; 1387 new_inode = EXT2_FIRST_INODE(rfs->new_fs->super); 1388 inode_size = EXT2_INODE_SIZE(rfs->new_fs->super); 1389 inode = malloc(inode_size); 1390 if (!inode) { 1391 retval = ENOMEM; 1392 goto errout; 1393 } 1394 /* 1395 * First, copy all of the inodes that need to be moved 1396 * elsewhere in the inode table 1397 */ 1398 while (1) { 1399 retval = ext2fs_get_next_inode_full(scan, &ino, inode, inode_size); 1400 if (retval) goto errout; 1401 if (!ino) 1402 break; 1403 1404 if (inode->i_links_count == 0 && ino != EXT2_RESIZE_INO) 1405 continue; /* inode not in use */ 1406 1407 pb.is_dir = LINUX_S_ISDIR(inode->i_mode); 1408 pb.changed = 0; 1409 1410 if (ext2fs_file_acl_block(rfs->old_fs, inode) && rfs->bmap) { 1411 new_block = ext2fs_extent_translate(rfs->bmap, 1412 ext2fs_file_acl_block(rfs->old_fs, inode)); 1413 if (new_block) { 1414 ext2fs_file_acl_block_set(rfs->old_fs, inode, 1415 new_block); 1416 retval = ext2fs_write_inode_full(rfs->old_fs, 1417 ino, inode, inode_size); 1418 if (retval) goto errout; 1419 } 1420 } 1421 1422 if (ext2fs_inode_has_valid_blocks2(rfs->old_fs, inode) && 1423 (rfs->bmap || pb.is_dir)) { 1424 pb.ino = ino; 1425 retval = ext2fs_block_iterate3(rfs->old_fs, 1426 ino, 0, block_buf, 1427 process_block, &pb); 1428 if (retval) 1429 goto errout; 1430 if (pb.error) { 1431 retval = pb.error; 1432 goto errout; 1433 } 1434 } 1435 1436 if (ino <= start_to_move) 1437 continue; /* Don't need to move it. */ 1438 1439 /* 1440 * Find a new inode 1441 */ 1442 retval = ext2fs_new_inode(rfs->new_fs, 0, 0, 0, &new_inode); 1443 if (retval) 1444 goto errout; 1445 1446 ext2fs_inode_alloc_stats2(rfs->new_fs, new_inode, +1, 1447 pb.is_dir); 1448 if (pb.changed) { 1449 /* Get the new version of the inode */ 1450 retval = ext2fs_read_inode_full(rfs->old_fs, ino, 1451 inode, inode_size); 1452 if (retval) goto errout; 1453 } 1454 inode->i_ctime = time(0); 1455 retval = ext2fs_write_inode_full(rfs->old_fs, new_inode, 1456 inode, inode_size); 1457 if (retval) goto errout; 1458 1459#ifdef RESIZE2FS_DEBUG 1460 if (rfs->flags & RESIZE_DEBUG_INODEMAP) 1461 printf("Inode moved %u->%u\n", ino, new_inode); 1462#endif 1463 if (!rfs->imap) { 1464 retval = ext2fs_create_extent_table(&rfs->imap, 0); 1465 if (retval) 1466 goto errout; 1467 } 1468 ext2fs_add_extent_entry(rfs->imap, ino, new_inode); 1469 } 1470 io_channel_flush(rfs->old_fs->io); 1471 1472errout: 1473 ext2fs_blocks_count_set(rfs->old_fs->super, orig_size); 1474 if (rfs->bmap) { 1475 ext2fs_free_extent_table(rfs->bmap); 1476 rfs->bmap = 0; 1477 } 1478 if (scan) 1479 ext2fs_close_inode_scan(scan); 1480 if (block_buf) 1481 ext2fs_free_mem(&block_buf); 1482 free(inode); 1483 return retval; 1484} 1485 1486/* -------------------------------------------------------------------- 1487 * 1488 * Resize processing, phase 4. 1489 * 1490 * -------------------------------------------------------------------- 1491 */ 1492 1493struct istruct { 1494 ext2_resize_t rfs; 1495 errcode_t err; 1496 unsigned int max_dirs; 1497 unsigned int num; 1498}; 1499 1500static int check_and_change_inodes(ext2_ino_t dir, 1501 int entry EXT2FS_ATTR((unused)), 1502 struct ext2_dir_entry *dirent, int offset, 1503 int blocksize EXT2FS_ATTR((unused)), 1504 char *buf EXT2FS_ATTR((unused)), 1505 void *priv_data) 1506{ 1507 struct istruct *is = (struct istruct *) priv_data; 1508 struct ext2_inode inode; 1509 ext2_ino_t new_inode; 1510 errcode_t retval; 1511 1512 if (is->rfs->progress && offset == 0) { 1513 io_channel_flush(is->rfs->old_fs->io); 1514 is->err = (is->rfs->progress)(is->rfs, 1515 E2_RSZ_INODE_REF_UPD_PASS, 1516 ++is->num, is->max_dirs); 1517 if (is->err) 1518 return DIRENT_ABORT; 1519 } 1520 1521 if (!dirent->inode) 1522 return 0; 1523 1524 new_inode = ext2fs_extent_translate(is->rfs->imap, dirent->inode); 1525 1526 if (!new_inode) 1527 return 0; 1528#ifdef RESIZE2FS_DEBUG 1529 if (is->rfs->flags & RESIZE_DEBUG_INODEMAP) 1530 printf("Inode translate (dir=%u, name=%.*s, %u->%u)\n", 1531 dir, dirent->name_len&0xFF, dirent->name, 1532 dirent->inode, new_inode); 1533#endif 1534 1535 dirent->inode = new_inode; 1536 1537 /* Update the directory mtime and ctime */ 1538 retval = ext2fs_read_inode(is->rfs->old_fs, dir, &inode); 1539 if (retval == 0) { 1540 inode.i_mtime = inode.i_ctime = time(0); 1541 is->err = ext2fs_write_inode(is->rfs->old_fs, dir, &inode); 1542 if (is->err) 1543 return DIRENT_ABORT; 1544 } 1545 1546 return DIRENT_CHANGED; 1547} 1548 1549static errcode_t inode_ref_fix(ext2_resize_t rfs) 1550{ 1551 errcode_t retval; 1552 struct istruct is; 1553 1554 if (!rfs->imap) 1555 return 0; 1556 1557 /* 1558 * Now, we iterate over all of the directories to update the 1559 * inode references 1560 */ 1561 is.num = 0; 1562 is.max_dirs = ext2fs_dblist_count2(rfs->old_fs->dblist); 1563 is.rfs = rfs; 1564 is.err = 0; 1565 1566 if (rfs->progress) { 1567 retval = (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS, 1568 0, is.max_dirs); 1569 if (retval) 1570 goto errout; 1571 } 1572 1573 retval = ext2fs_dblist_dir_iterate(rfs->old_fs->dblist, 1574 DIRENT_FLAG_INCLUDE_EMPTY, 0, 1575 check_and_change_inodes, &is); 1576 if (retval) 1577 goto errout; 1578 if (is.err) { 1579 retval = is.err; 1580 goto errout; 1581 } 1582 1583 if (rfs->progress && (is.num < is.max_dirs)) 1584 (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS, 1585 is.max_dirs, is.max_dirs); 1586 1587errout: 1588 ext2fs_free_extent_table(rfs->imap); 1589 rfs->imap = 0; 1590 return retval; 1591} 1592 1593 1594/* -------------------------------------------------------------------- 1595 * 1596 * Resize processing, phase 5. 1597 * 1598 * In this phase we actually move the inode table around, and then 1599 * update the summary statistics. This is scary, since aborting here 1600 * will potentially scramble the filesystem. (We are moving the 1601 * inode tables around in place, and so the potential for lost data, 1602 * or at the very least scrambling the mapping between filenames and 1603 * inode numbers is very high in case of a power failure here.) 1604 * -------------------------------------------------------------------- 1605 */ 1606 1607 1608/* 1609 * A very scary routine --- this one moves the inode table around!!! 1610 * 1611 * After this you have to use the rfs->new_fs file handle to read and 1612 * write inodes. 1613 */ 1614static errcode_t move_itables(ext2_resize_t rfs) 1615{ 1616 int n, num, size; 1617 long long diff; 1618 dgrp_t i, max_groups; 1619 ext2_filsys fs = rfs->new_fs; 1620 char *cp; 1621 blk64_t old_blk, new_blk, blk; 1622 errcode_t retval; 1623 int j, to_move, moved; 1624 1625 max_groups = fs->group_desc_count; 1626 if (max_groups > rfs->old_fs->group_desc_count) 1627 max_groups = rfs->old_fs->group_desc_count; 1628 1629 size = fs->blocksize * fs->inode_blocks_per_group; 1630 if (!rfs->itable_buf) { 1631 retval = ext2fs_get_mem(size, &rfs->itable_buf); 1632 if (retval) 1633 return retval; 1634 } 1635 1636 /* 1637 * Figure out how many inode tables we need to move 1638 */ 1639 to_move = moved = 0; 1640 for (i=0; i < max_groups; i++) 1641 if (ext2fs_inode_table_loc(rfs->old_fs, i) != 1642 ext2fs_inode_table_loc(fs, i)) 1643 to_move++; 1644 1645 if (to_move == 0) 1646 return 0; 1647 1648 if (rfs->progress) { 1649 retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS, 1650 0, to_move); 1651 if (retval) 1652 goto errout; 1653 } 1654 1655 rfs->old_fs->flags |= EXT2_FLAG_MASTER_SB_ONLY; 1656 1657 for (i=0; i < max_groups; i++) { 1658 old_blk = ext2fs_inode_table_loc(rfs->old_fs, i); 1659 new_blk = ext2fs_inode_table_loc(fs, i); 1660 diff = new_blk - old_blk; 1661 1662#ifdef RESIZE2FS_DEBUG 1663 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE) 1664 printf("Itable move group %d block %llu->%llu (diff %lld)\n", 1665 i, old_blk, new_blk, diff); 1666#endif 1667 1668 if (!diff) 1669 continue; 1670 1671 retval = io_channel_read_blk64(fs->io, old_blk, 1672 fs->inode_blocks_per_group, 1673 rfs->itable_buf); 1674 if (retval) 1675 goto errout; 1676 /* 1677 * The end of the inode table segment often contains 1678 * all zeros, and we're often only moving the inode 1679 * table down a block or two. If so, we can optimize 1680 * things by not rewriting blocks that we know to be zero 1681 * already. 1682 */ 1683 for (cp = rfs->itable_buf+size-1, n=0; n < size; n++, cp--) 1684 if (*cp) 1685 break; 1686 n = n >> EXT2_BLOCK_SIZE_BITS(fs->super); 1687#ifdef RESIZE2FS_DEBUG 1688 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE) 1689 printf("%d blocks of zeros...\n", n); 1690#endif 1691 num = fs->inode_blocks_per_group; 1692 if (n > diff) 1693 num -= n; 1694 1695 retval = io_channel_write_blk64(fs->io, new_blk, 1696 num, rfs->itable_buf); 1697 if (retval) { 1698 io_channel_write_blk64(fs->io, old_blk, 1699 num, rfs->itable_buf); 1700 goto errout; 1701 } 1702 if (n > diff) { 1703 retval = io_channel_write_blk64(fs->io, 1704 old_blk + fs->inode_blocks_per_group, 1705 diff, (rfs->itable_buf + 1706 (fs->inode_blocks_per_group - diff) * 1707 fs->blocksize)); 1708 if (retval) 1709 goto errout; 1710 } 1711 1712 for (blk = ext2fs_inode_table_loc(rfs->old_fs, i), j=0; 1713 j < fs->inode_blocks_per_group ; j++, blk++) 1714 ext2fs_block_alloc_stats2(fs, blk, -1); 1715 1716 ext2fs_inode_table_loc_set(rfs->old_fs, i, new_blk); 1717 ext2fs_group_desc_csum_set(rfs->old_fs, i); 1718 ext2fs_mark_super_dirty(rfs->old_fs); 1719 ext2fs_flush(rfs->old_fs); 1720 1721 if (rfs->progress) { 1722 retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS, 1723 ++moved, to_move); 1724 if (retval) 1725 goto errout; 1726 } 1727 } 1728 mark_table_blocks(fs, fs->block_map); 1729 ext2fs_flush(fs); 1730#ifdef RESIZE2FS_DEBUG 1731 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE) 1732 printf("Inode table move finished.\n"); 1733#endif 1734 return 0; 1735 1736errout: 1737 return retval; 1738} 1739 1740/* 1741 * Fix the resize inode 1742 */ 1743static errcode_t fix_resize_inode(ext2_filsys fs) 1744{ 1745 struct ext2_inode inode; 1746 errcode_t retval; 1747 char *block_buf = NULL; 1748 1749 if (!(fs->super->s_feature_compat & 1750 EXT2_FEATURE_COMPAT_RESIZE_INODE)) 1751 return 0; 1752 1753 retval = ext2fs_get_mem(fs->blocksize, &block_buf); 1754 if (retval) goto errout; 1755 1756 retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode); 1757 if (retval) goto errout; 1758 1759 ext2fs_iblk_set(fs, &inode, 1); 1760 1761 retval = ext2fs_write_inode(fs, EXT2_RESIZE_INO, &inode); 1762 if (retval) goto errout; 1763 1764 if (!inode.i_block[EXT2_DIND_BLOCK]) { 1765 /* 1766 * Avoid zeroing out block #0; that's rude. This 1767 * should never happen anyway since the filesystem 1768 * should be fsck'ed and we assume it is consistent. 1769 */ 1770 fprintf(stderr, 1771 _("Should never happen: resize inode corrupt!\n")); 1772 exit(1); 1773 } 1774 1775 memset(block_buf, 0, fs->blocksize); 1776 1777 retval = io_channel_write_blk64(fs->io, inode.i_block[EXT2_DIND_BLOCK], 1778 1, block_buf); 1779 if (retval) goto errout; 1780 1781 retval = ext2fs_create_resize_inode(fs); 1782 if (retval) 1783 goto errout; 1784 1785errout: 1786 if (block_buf) 1787 ext2fs_free_mem(&block_buf); 1788 return retval; 1789} 1790 1791/* 1792 * Finally, recalculate the summary information 1793 */ 1794static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs) 1795{ 1796 blk64_t blk; 1797 ext2_ino_t ino; 1798 unsigned int group = 0; 1799 unsigned int count = 0; 1800 int total_free = 0; 1801 int group_free = 0; 1802 int uninit = 0; 1803 blk64_t super_blk, old_desc_blk, new_desc_blk; 1804 int old_desc_blocks; 1805 1806 /* 1807 * First calculate the block statistics 1808 */ 1809 uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT); 1810 ext2fs_super_and_bgd_loc2(fs, group, &super_blk, &old_desc_blk, 1811 &new_desc_blk, 0); 1812 if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) 1813 old_desc_blocks = fs->super->s_first_meta_bg; 1814 else 1815 old_desc_blocks = fs->desc_blocks + 1816 fs->super->s_reserved_gdt_blocks; 1817 for (blk = fs->super->s_first_data_block; 1818 blk < ext2fs_blocks_count(fs->super); blk++) { 1819 if ((uninit && 1820 !((blk == super_blk) || 1821 ((old_desc_blk && old_desc_blocks && 1822 (blk >= old_desc_blk) && 1823 (blk < old_desc_blk + old_desc_blocks))) || 1824 ((new_desc_blk && (blk == new_desc_blk))) || 1825 (blk == ext2fs_block_bitmap_loc(fs, group)) || 1826 (blk == ext2fs_inode_bitmap_loc(fs, group)) || 1827 ((blk >= ext2fs_inode_table_loc(fs, group) && 1828 (blk < ext2fs_inode_table_loc(fs, group) 1829 + fs->inode_blocks_per_group))))) || 1830 (!ext2fs_fast_test_block_bitmap2(fs->block_map, blk))) { 1831 group_free++; 1832 total_free++; 1833 } 1834 count++; 1835 if ((count == fs->super->s_blocks_per_group) || 1836 (blk == ext2fs_blocks_count(fs->super)-1)) { 1837 ext2fs_bg_free_blocks_count_set(fs, group, group_free); 1838 ext2fs_group_desc_csum_set(fs, group); 1839 group++; 1840 if (group >= fs->group_desc_count) 1841 break; 1842 count = 0; 1843 group_free = 0; 1844 uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT); 1845 ext2fs_super_and_bgd_loc2(fs, group, &super_blk, 1846 &old_desc_blk, 1847 &new_desc_blk, 0); 1848 if (fs->super->s_feature_incompat & 1849 EXT2_FEATURE_INCOMPAT_META_BG) 1850 old_desc_blocks = fs->super->s_first_meta_bg; 1851 else 1852 old_desc_blocks = fs->desc_blocks + 1853 fs->super->s_reserved_gdt_blocks; 1854 } 1855 } 1856 ext2fs_free_blocks_count_set(fs->super, total_free); 1857 1858 /* 1859 * Next, calculate the inode statistics 1860 */ 1861 group_free = 0; 1862 total_free = 0; 1863 count = 0; 1864 group = 0; 1865 1866 /* Protect loop from wrap-around if s_inodes_count maxed */ 1867 uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT); 1868 for (ino = 1; ino <= fs->super->s_inodes_count && ino > 0; ino++) { 1869 if (uninit || 1870 !ext2fs_fast_test_inode_bitmap2(fs->inode_map, ino)) { 1871 group_free++; 1872 total_free++; 1873 } 1874 count++; 1875 if ((count == fs->super->s_inodes_per_group) || 1876 (ino == fs->super->s_inodes_count)) { 1877 ext2fs_bg_free_inodes_count_set(fs, group, group_free); 1878 ext2fs_group_desc_csum_set(fs, group); 1879 group++; 1880 if (group >= fs->group_desc_count) 1881 break; 1882 count = 0; 1883 group_free = 0; 1884 uninit = ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT); 1885 } 1886 } 1887 fs->super->s_free_inodes_count = total_free; 1888 ext2fs_mark_super_dirty(fs); 1889 return 0; 1890} 1891 1892/* 1893 * Journal may have been relocated; update the backup journal blocks 1894 * in the superblock. 1895 */ 1896static errcode_t fix_sb_journal_backup(ext2_filsys fs) 1897{ 1898 errcode_t retval; 1899 struct ext2_inode inode; 1900 1901 if (!(fs->super->s_feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL)) 1902 return 0; 1903 1904 /* External journal? Nothing to do. */ 1905 if (fs->super->s_journal_dev && !fs->super->s_journal_inum) 1906 return 0; 1907 1908 retval = ext2fs_read_inode(fs, fs->super->s_journal_inum, &inode); 1909 if (retval) 1910 return retval; 1911 memcpy(fs->super->s_jnl_blocks, inode.i_block, EXT2_N_BLOCKS*4); 1912 fs->super->s_jnl_blocks[15] = inode.i_size_high; 1913 fs->super->s_jnl_blocks[16] = inode.i_size; 1914 fs->super->s_jnl_backup_type = EXT3_JNL_BACKUP_BLOCKS; 1915 ext2fs_mark_super_dirty(fs); 1916 return 0; 1917} 1918 1919static int calc_group_overhead(ext2_filsys fs, blk64_t grp, 1920 int old_desc_blocks) 1921{ 1922 blk64_t super_blk, old_desc_blk, new_desc_blk; 1923 int overhead; 1924 1925 /* inode table blocks plus allocation bitmaps */ 1926 overhead = fs->inode_blocks_per_group + 2; 1927 1928 ext2fs_super_and_bgd_loc2(fs, grp, &super_blk, 1929 &old_desc_blk, &new_desc_blk, 0); 1930 if ((grp == 0) || super_blk) 1931 overhead++; 1932 if (old_desc_blk) 1933 overhead += old_desc_blocks; 1934 else if (new_desc_blk) 1935 overhead++; 1936 return overhead; 1937} 1938 1939 1940/* 1941 * calcluate the minimum number of blocks the given fs can be resized to 1942 */ 1943blk64_t calculate_minimum_resize_size(ext2_filsys fs) 1944{ 1945 ext2_ino_t inode_count; 1946 blk64_t blks_needed, groups, data_blocks; 1947 blk64_t grp, data_needed, last_start; 1948 blk64_t overhead = 0; 1949 int old_desc_blocks; 1950 int extra_groups = 0; 1951 int flexbg_size = 1 << fs->super->s_log_groups_per_flex; 1952 1953 /* 1954 * first figure out how many group descriptors we need to 1955 * handle the number of inodes we have 1956 */ 1957 inode_count = fs->super->s_inodes_count - 1958 fs->super->s_free_inodes_count; 1959 blks_needed = ext2fs_div_ceil(inode_count, 1960 fs->super->s_inodes_per_group) * 1961 EXT2_BLOCKS_PER_GROUP(fs->super); 1962 groups = ext2fs_div64_ceil(blks_needed, 1963 EXT2_BLOCKS_PER_GROUP(fs->super)); 1964 1965 /* 1966 * number of old-style block group descriptor blocks 1967 */ 1968 if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) 1969 old_desc_blocks = fs->super->s_first_meta_bg; 1970 else 1971 old_desc_blocks = fs->desc_blocks + 1972 fs->super->s_reserved_gdt_blocks; 1973 1974 /* calculate how many blocks are needed for data */ 1975 data_needed = ext2fs_blocks_count(fs->super) - 1976 ext2fs_free_blocks_count(fs->super); 1977 1978 for (grp = 0; grp < fs->group_desc_count; grp++) 1979 data_needed -= calc_group_overhead(fs, grp, old_desc_blocks); 1980 1981 /* 1982 * For ext4 we need to allow for up to a flex_bg worth of 1983 * inode tables of slack space so the resize operation can be 1984 * guaranteed to finish. 1985 */ 1986 if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_FLEX_BG) { 1987 extra_groups = flexbg_size - (groups & (flexbg_size - 1)); 1988 data_needed += fs->inode_blocks_per_group * extra_groups; 1989 extra_groups = groups % flexbg_size; 1990 } 1991 1992 /* 1993 * figure out how many data blocks we have given the number of groups 1994 * we need for our inodes 1995 */ 1996 data_blocks = groups * EXT2_BLOCKS_PER_GROUP(fs->super); 1997 last_start = 0; 1998 for (grp = 0; grp < groups; grp++) { 1999 overhead = calc_group_overhead(fs, grp, old_desc_blocks); 2000 2001 /* 2002 * we want to keep track of how much data we can store in 2003 * the groups leading up to the last group so we can determine 2004 * how big the last group needs to be 2005 */ 2006 if (grp != (groups - 1)) 2007 last_start += EXT2_BLOCKS_PER_GROUP(fs->super) - 2008 overhead; 2009 2010 data_blocks -= overhead; 2011 } 2012 2013 /* 2014 * if we need more group descriptors in order to accomodate our data 2015 * then we need to add them here 2016 */ 2017 while (data_needed > data_blocks) { 2018 blk64_t remainder = data_needed - data_blocks; 2019 blk64_t extra_grps; 2020 2021 /* figure out how many more groups we need for the data */ 2022 extra_grps = ext2fs_div64_ceil(remainder, 2023 EXT2_BLOCKS_PER_GROUP(fs->super)); 2024 2025 data_blocks += extra_grps * EXT2_BLOCKS_PER_GROUP(fs->super); 2026 2027 /* ok we have to account for the last group */ 2028 overhead = calc_group_overhead(fs, groups-1, old_desc_blocks); 2029 last_start += EXT2_BLOCKS_PER_GROUP(fs->super) - overhead; 2030 2031 for (grp = groups; grp < groups+extra_grps; grp++) { 2032 overhead = calc_group_overhead(fs, grp, 2033 old_desc_blocks); 2034 2035 /* 2036 * again, we need to see how much data we cram into 2037 * all of the groups leading up to the last group 2038 */ 2039 if (grp != (groups + extra_grps - 1)) 2040 last_start += EXT2_BLOCKS_PER_GROUP(fs->super) 2041 - overhead; 2042 2043 data_blocks -= overhead; 2044 } 2045 2046 groups += extra_grps; 2047 extra_groups += extra_grps; 2048 if (fs->super->s_feature_incompat 2049 & EXT4_FEATURE_INCOMPAT_FLEX_BG 2050 && extra_groups > flexbg_size) { 2051 /* 2052 * For ext4 we need to allow for up to a flex_bg worth 2053 * of inode tables of slack space so the resize 2054 * operation can be guaranteed to finish. 2055 */ 2056 extra_groups = flexbg_size - 2057 (groups & (flexbg_size - 1)); 2058 data_needed += (fs->inode_blocks_per_group * 2059 extra_groups); 2060 extra_groups = groups % flexbg_size; 2061 } 2062 } 2063 2064 /* now for the fun voodoo */ 2065 overhead = calc_group_overhead(fs, groups-1, old_desc_blocks); 2066 2067 /* 2068 * if this is the case then the last group is going to have data in it 2069 * so we need to adjust the size of the last group accordingly 2070 */ 2071 if (last_start < data_needed) { 2072 blk64_t remainder = data_needed - last_start; 2073 2074 /* 2075 * 50 is a magic number that mkfs/resize uses to see if its 2076 * even worth making/resizing the fs. basically you need to 2077 * have at least 50 blocks in addition to the blocks needed 2078 * for the metadata in the last group 2079 */ 2080 if (remainder > 50) 2081 overhead += remainder; 2082 else 2083 overhead += 50; 2084 } else 2085 overhead += 50; 2086 2087 overhead += fs->super->s_first_data_block; 2088 2089 /* 2090 * since our last group doesn't have to be BLOCKS_PER_GROUP large, we 2091 * only do groups-1, and then add the number of blocks needed to 2092 * handle the group descriptor metadata+data that we need 2093 */ 2094 blks_needed = (groups-1) * EXT2_BLOCKS_PER_GROUP(fs->super); 2095 blks_needed += overhead; 2096 2097 /* 2098 * If at this point we've already added up more "needed" than 2099 * the current size, just return current size as minimum. 2100 */ 2101 if (blks_needed >= ext2fs_blocks_count(fs->super)) 2102 return ext2fs_blocks_count(fs->super); 2103 /* 2104 * We need to reserve a few extra blocks if extents are 2105 * enabled, in case we need to grow the extent tree. The more 2106 * we shrink the file system, the more space we need. 2107 */ 2108 if (fs->super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_EXTENTS) 2109 blks_needed += (ext2fs_blocks_count(fs->super) - 2110 blks_needed)/500; 2111 2112 return blks_needed; 2113} 2114