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 "resize2fs.h"
37 #include <time.h>
38
39 #ifdef __linux__ /* Kludge for debugging */
40 #define RESIZE2FS_DEBUG
41 #endif
42
43 static void fix_uninit_block_bitmaps(ext2_filsys fs);
44 static errcode_t adjust_superblock(ext2_resize_t rfs, blk_t new_size);
45 static errcode_t blocks_to_move(ext2_resize_t rfs);
46 static errcode_t block_mover(ext2_resize_t rfs);
47 static errcode_t inode_scan_and_fix(ext2_resize_t rfs);
48 static errcode_t inode_ref_fix(ext2_resize_t rfs);
49 static errcode_t move_itables(ext2_resize_t rfs);
50 static errcode_t fix_resize_inode(ext2_filsys fs);
51 static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs);
52 static errcode_t fix_sb_journal_backup(ext2_filsys fs);
53
54 /*
55 * Some helper CPP macros
56 */
57 #define FS_BLOCK_BM(fs, i) ((fs)->group_desc[(i)].bg_block_bitmap)
58 #define FS_INODE_BM(fs, i) ((fs)->group_desc[(i)].bg_inode_bitmap)
59 #define FS_INODE_TB(fs, i) ((fs)->group_desc[(i)].bg_inode_table)
60
61 #define IS_BLOCK_BM(fs, i, blk) ((blk) == FS_BLOCK_BM((fs),(i)))
62 #define IS_INODE_BM(fs, i, blk) ((blk) == FS_INODE_BM((fs),(i)))
63
64 #define IS_INODE_TB(fs, i, blk) (((blk) >= FS_INODE_TB((fs), (i))) && \
65 ((blk) < (FS_INODE_TB((fs), (i)) + \
66 (fs)->inode_blocks_per_group)))
67
68 #define META_OVERHEAD(fs) (2 + (fs)->inode_blocks_per_group)
69 #define SUPER_OVERHEAD(fs) (1 + (fs)->desc_blocks +\
70 (fs)->super->s_reserved_gdt_blocks)
71
72 /*
73 * This is the top-level routine which does the dirty deed....
74 */
resize_fs(ext2_filsys fs,blk_t * new_size,int flags,errcode_t (* progress)(ext2_resize_t rfs,int pass,unsigned long cur,unsigned long max_val))75 errcode_t resize_fs(ext2_filsys fs, blk_t *new_size, int flags,
76 errcode_t (*progress)(ext2_resize_t rfs, int pass,
77 unsigned long cur,
78 unsigned long max_val))
79 {
80 ext2_resize_t rfs;
81 errcode_t retval;
82
83 retval = ext2fs_read_bitmaps(fs);
84 if (retval)
85 return retval;
86
87 fs->super->s_state |= EXT2_ERROR_FS;
88 ext2fs_mark_super_dirty(fs);
89 ext2fs_flush(fs);
90
91 /*
92 * Create the data structure
93 */
94 retval = ext2fs_get_mem(sizeof(struct ext2_resize_struct), &rfs);
95 if (retval)
96 return retval;
97 memset(rfs, 0, sizeof(struct ext2_resize_struct));
98
99 fix_uninit_block_bitmaps(fs);
100 fs->priv_data = rfs;
101 rfs->old_fs = fs;
102 rfs->flags = flags;
103 rfs->itable_buf = 0;
104 rfs->progress = progress;
105 retval = ext2fs_dup_handle(fs, &rfs->new_fs);
106 if (retval)
107 goto errout;
108
109 retval = adjust_superblock(rfs, *new_size);
110 if (retval)
111 goto errout;
112
113 fix_uninit_block_bitmaps(rfs->new_fs);
114 /* Clear the block bitmap uninit flag for the last block group */
115 rfs->new_fs->group_desc[rfs->new_fs->group_desc_count-1].bg_flags &=
116 ~EXT2_BG_BLOCK_UNINIT;
117
118 *new_size = rfs->new_fs->super->s_blocks_count;
119
120 retval = blocks_to_move(rfs);
121 if (retval)
122 goto errout;
123
124 #ifdef RESIZE2FS_DEBUG
125 if (rfs->flags & RESIZE_DEBUG_BMOVE)
126 printf("Number of free blocks: %u/%u, Needed: %d\n",
127 rfs->old_fs->super->s_free_blocks_count,
128 rfs->new_fs->super->s_free_blocks_count,
129 rfs->needed_blocks);
130 #endif
131
132 retval = block_mover(rfs);
133 if (retval)
134 goto errout;
135
136 retval = inode_scan_and_fix(rfs);
137 if (retval)
138 goto errout;
139
140 retval = inode_ref_fix(rfs);
141 if (retval)
142 goto errout;
143
144 retval = move_itables(rfs);
145 if (retval)
146 goto errout;
147
148 retval = ext2fs_calculate_summary_stats(rfs->new_fs);
149 if (retval)
150 goto errout;
151
152 retval = fix_resize_inode(rfs->new_fs);
153 if (retval)
154 goto errout;
155
156 retval = fix_sb_journal_backup(rfs->new_fs);
157 if (retval)
158 goto errout;
159
160 rfs->new_fs->super->s_state &= ~EXT2_ERROR_FS;
161 rfs->new_fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
162 retval = ext2fs_close(rfs->new_fs);
163 if (retval)
164 goto errout;
165
166 rfs->flags = flags;
167
168 ext2fs_free(rfs->old_fs);
169 if (rfs->itable_buf)
170 ext2fs_free_mem(&rfs->itable_buf);
171 if (rfs->reserve_blocks)
172 ext2fs_free_block_bitmap(rfs->reserve_blocks);
173 if (rfs->move_blocks)
174 ext2fs_free_block_bitmap(rfs->move_blocks);
175 ext2fs_free_mem(&rfs);
176
177 return 0;
178
179 errout:
180 if (rfs->new_fs)
181 ext2fs_free(rfs->new_fs);
182 if (rfs->itable_buf)
183 ext2fs_free_mem(&rfs->itable_buf);
184 ext2fs_free_mem(&rfs);
185 return retval;
186 }
187
188 /*
189 * Clean up the bitmaps for unitialized bitmaps
190 */
fix_uninit_block_bitmaps(ext2_filsys fs)191 static void fix_uninit_block_bitmaps(ext2_filsys fs)
192 {
193 blk_t i, blk, super_blk, old_desc_blk, new_desc_blk;
194 int old_desc_blocks;
195 dgrp_t g;
196
197 if (!(EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
198 EXT4_FEATURE_RO_COMPAT_GDT_CSUM)))
199 return;
200
201 for (g=0; g < fs->group_desc_count; g++) {
202 if (!(fs->group_desc[g].bg_flags & EXT2_BG_BLOCK_UNINIT))
203 continue;
204
205 blk = (g * fs->super->s_blocks_per_group) +
206 fs->super->s_first_data_block;
207
208 ext2fs_super_and_bgd_loc(fs, g, &super_blk,
209 &old_desc_blk, &new_desc_blk, 0);
210
211 if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
212 old_desc_blocks = fs->super->s_first_meta_bg;
213 else
214 old_desc_blocks = fs->desc_blocks +
215 fs->super->s_reserved_gdt_blocks;
216
217 for (i=0; i < fs->super->s_blocks_per_group; i++, blk++) {
218 if (blk >= fs->super->s_blocks_count)
219 break;
220 if ((blk == super_blk) ||
221 (old_desc_blk && old_desc_blocks &&
222 (blk >= old_desc_blk) &&
223 (blk < old_desc_blk + old_desc_blocks)) ||
224 (new_desc_blk && (blk == new_desc_blk)) ||
225 (blk == fs->group_desc[g].bg_block_bitmap) ||
226 (blk == fs->group_desc[g].bg_inode_bitmap) ||
227 (blk >= fs->group_desc[g].bg_inode_table &&
228 (blk < fs->group_desc[g].bg_inode_table
229 + fs->inode_blocks_per_group)))
230 ext2fs_fast_mark_block_bitmap(fs->block_map, blk);
231 else
232 ext2fs_fast_unmark_block_bitmap(fs->block_map, blk);
233 }
234 }
235 }
236
237 /* --------------------------------------------------------------------
238 *
239 * Resize processing, phase 1.
240 *
241 * In this phase we adjust the in-memory superblock information, and
242 * initialize any new parts of the inode table. The new parts of the
243 * inode table are created in virgin disk space, so we can abort here
244 * without any side effects.
245 * --------------------------------------------------------------------
246 */
247
248 /*
249 * If the group descriptor's bitmap and inode table blocks are valid,
250 * release them in the new filesystem data structure, and mark them as
251 * reserved so the old inode table blocks don't get overwritten.
252 */
free_gdp_blocks(ext2_filsys fs,ext2fs_block_bitmap reserve_blocks,struct ext2_group_desc * gdp)253 static void free_gdp_blocks(ext2_filsys fs,
254 ext2fs_block_bitmap reserve_blocks,
255 struct ext2_group_desc *gdp)
256 {
257 blk_t blk;
258 int j;
259
260 if (gdp->bg_block_bitmap &&
261 (gdp->bg_block_bitmap < fs->super->s_blocks_count)) {
262 ext2fs_block_alloc_stats(fs, gdp->bg_block_bitmap, -1);
263 ext2fs_mark_block_bitmap(reserve_blocks,
264 gdp->bg_block_bitmap);
265 }
266
267 if (gdp->bg_inode_bitmap &&
268 (gdp->bg_inode_bitmap < fs->super->s_blocks_count)) {
269 ext2fs_block_alloc_stats(fs, gdp->bg_inode_bitmap, -1);
270 ext2fs_mark_block_bitmap(reserve_blocks,
271 gdp->bg_inode_bitmap);
272 }
273
274 if (gdp->bg_inode_table == 0 ||
275 (gdp->bg_inode_table >= fs->super->s_blocks_count))
276 return;
277
278 for (blk = gdp->bg_inode_table, j = 0;
279 j < fs->inode_blocks_per_group; j++, blk++) {
280 if (blk >= fs->super->s_blocks_count)
281 break;
282 ext2fs_block_alloc_stats(fs, blk, -1);
283 ext2fs_mark_block_bitmap(reserve_blocks, blk);
284 }
285 }
286
287 /*
288 * This routine is shared by the online and offline resize routines.
289 * All of the information which is adjusted in memory is done here.
290 *
291 * The reserve_blocks parameter is only needed when shrinking the
292 * filesystem.
293 */
adjust_fs_info(ext2_filsys fs,ext2_filsys old_fs,ext2fs_block_bitmap reserve_blocks,blk_t new_size)294 errcode_t adjust_fs_info(ext2_filsys fs, ext2_filsys old_fs,
295 ext2fs_block_bitmap reserve_blocks, blk_t new_size)
296 {
297 errcode_t retval;
298 int overhead = 0;
299 int rem;
300 blk_t blk, group_block;
301 ext2_ino_t real_end;
302 int adj, old_numblocks, numblocks, adjblocks;
303 unsigned long i, j, old_desc_blocks, max_group;
304 unsigned int meta_bg, meta_bg_size;
305 int has_super, csum_flag;
306 unsigned long long new_inodes; /* u64 to check for overflow */
307 double percent;
308
309 fs->super->s_blocks_count = new_size;
310
311 retry:
312 fs->group_desc_count = ext2fs_div_ceil(fs->super->s_blocks_count -
313 fs->super->s_first_data_block,
314 EXT2_BLOCKS_PER_GROUP(fs->super));
315 if (fs->group_desc_count == 0)
316 return EXT2_ET_TOOSMALL;
317 fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count,
318 EXT2_DESC_PER_BLOCK(fs->super));
319
320 /*
321 * Overhead is the number of bookkeeping blocks per group. It
322 * includes the superblock backup, the group descriptor
323 * backups, the inode bitmap, the block bitmap, and the inode
324 * table.
325 */
326 overhead = (int) (2 + fs->inode_blocks_per_group);
327
328 if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1))
329 overhead += 1 + fs->desc_blocks +
330 fs->super->s_reserved_gdt_blocks;
331
332 /*
333 * See if the last group is big enough to support the
334 * necessary data structures. If not, we need to get rid of
335 * it.
336 */
337 rem = (fs->super->s_blocks_count - fs->super->s_first_data_block) %
338 fs->super->s_blocks_per_group;
339 if ((fs->group_desc_count == 1) && rem && (rem < overhead))
340 return EXT2_ET_TOOSMALL;
341 if (rem && (rem < overhead+50)) {
342 fs->super->s_blocks_count -= rem;
343 goto retry;
344 }
345 /*
346 * Adjust the number of inodes
347 */
348 new_inodes =(unsigned long long) fs->super->s_inodes_per_group * fs->group_desc_count;
349 if (new_inodes > ~0U) {
350 fprintf(stderr, _("inodes (%llu) must be less than %u"),
351 new_inodes, ~0U);
352 return EXT2_ET_TOO_MANY_INODES;
353 }
354 fs->super->s_inodes_count = fs->super->s_inodes_per_group *
355 fs->group_desc_count;
356
357 /*
358 * Adjust the number of free blocks
359 */
360 blk = old_fs->super->s_blocks_count;
361 if (blk > fs->super->s_blocks_count)
362 fs->super->s_free_blocks_count -=
363 (blk - fs->super->s_blocks_count);
364 else
365 fs->super->s_free_blocks_count +=
366 (fs->super->s_blocks_count - blk);
367
368 /*
369 * Adjust the number of reserved blocks
370 */
371 percent = (old_fs->super->s_r_blocks_count * 100.0) /
372 old_fs->super->s_blocks_count;
373 fs->super->s_r_blocks_count = (unsigned int) (percent *
374 fs->super->s_blocks_count / 100.0);
375
376 /*
377 * Adjust the bitmaps for size
378 */
379 retval = ext2fs_resize_inode_bitmap(fs->super->s_inodes_count,
380 fs->super->s_inodes_count,
381 fs->inode_map);
382 if (retval) goto errout;
383
384 real_end = ((EXT2_BLOCKS_PER_GROUP(fs->super)
385 * fs->group_desc_count)) - 1 +
386 fs->super->s_first_data_block;
387 retval = ext2fs_resize_block_bitmap(fs->super->s_blocks_count-1,
388 real_end, fs->block_map);
389
390 if (retval) goto errout;
391
392 /*
393 * Reallocate the group descriptors as necessary.
394 */
395 if (old_fs->desc_blocks != fs->desc_blocks) {
396 retval = ext2fs_resize_mem(old_fs->desc_blocks *
397 fs->blocksize,
398 fs->desc_blocks * fs->blocksize,
399 &fs->group_desc);
400 if (retval)
401 goto errout;
402 if (fs->desc_blocks > old_fs->desc_blocks)
403 memset((char *) fs->group_desc +
404 (old_fs->desc_blocks * fs->blocksize), 0,
405 (fs->desc_blocks - old_fs->desc_blocks) *
406 fs->blocksize);
407 }
408
409 /*
410 * If the resize_inode feature is set, and we are changing the
411 * number of descriptor blocks, then adjust
412 * s_reserved_gdt_blocks if possible to avoid needing to move
413 * the inode table either now or in the future.
414 */
415 if ((fs->super->s_feature_compat &
416 EXT2_FEATURE_COMPAT_RESIZE_INODE) &&
417 (old_fs->desc_blocks != fs->desc_blocks)) {
418 int new;
419
420 new = ((int) fs->super->s_reserved_gdt_blocks) +
421 (old_fs->desc_blocks - fs->desc_blocks);
422 if (new < 0)
423 new = 0;
424 if (new > (int) fs->blocksize/4)
425 new = fs->blocksize/4;
426 fs->super->s_reserved_gdt_blocks = new;
427 }
428
429 /*
430 * If we are shrinking the number of block groups, we're done
431 * and can exit now.
432 */
433 if (old_fs->group_desc_count > fs->group_desc_count) {
434 /*
435 * Check the block groups that we are chopping off
436 * and free any blocks associated with their metadata
437 */
438 for (i = fs->group_desc_count;
439 i < old_fs->group_desc_count; i++) {
440 free_gdp_blocks(fs, reserve_blocks,
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 = (old_fs->super->s_blocks_count -
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 = (fs->super->s_blocks_count -
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 fs->group_desc[i].bg_free_blocks_count += (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 adj = old_fs->group_desc_count;
486 max_group = fs->group_desc_count - adj;
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(&fs->group_desc[i], 0,
495 sizeof(struct ext2_group_desc));
496 adjblocks = 0;
497
498 fs->group_desc[i].bg_flags = 0;
499 if (csum_flag)
500 fs->group_desc[i].bg_flags |= EXT2_BG_INODE_UNINIT |
501 EXT2_BG_INODE_ZEROED;
502 if (i == fs->group_desc_count-1) {
503 numblocks = (fs->super->s_blocks_count -
504 fs->super->s_first_data_block) %
505 fs->super->s_blocks_per_group;
506 if (!numblocks)
507 numblocks = fs->super->s_blocks_per_group;
508 } else {
509 numblocks = fs->super->s_blocks_per_group;
510 if (csum_flag)
511 fs->group_desc[i].bg_flags |=
512 EXT2_BG_BLOCK_UNINIT;
513 }
514
515 has_super = ext2fs_bg_has_super(fs, i);
516 if (has_super) {
517 ext2fs_block_alloc_stats(fs, group_block, +1);
518 adjblocks++;
519 }
520 meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
521 meta_bg = i / meta_bg_size;
522 if (!(fs->super->s_feature_incompat &
523 EXT2_FEATURE_INCOMPAT_META_BG) ||
524 (meta_bg < fs->super->s_first_meta_bg)) {
525 if (has_super) {
526 for (j=0; j < old_desc_blocks; j++)
527 ext2fs_block_alloc_stats(fs,
528 group_block + 1 + j, +1);
529 adjblocks += old_desc_blocks;
530 }
531 } else {
532 if (has_super)
533 has_super = 1;
534 if (((i % meta_bg_size) == 0) ||
535 ((i % meta_bg_size) == 1) ||
536 ((i % meta_bg_size) == (meta_bg_size-1)))
537 ext2fs_block_alloc_stats(fs,
538 group_block + has_super, +1);
539 }
540
541 adjblocks += 2 + fs->inode_blocks_per_group;
542
543 numblocks -= adjblocks;
544 fs->super->s_free_blocks_count -= adjblocks;
545 fs->super->s_free_inodes_count +=
546 fs->super->s_inodes_per_group;
547 fs->group_desc[i].bg_free_blocks_count = numblocks;
548 fs->group_desc[i].bg_free_inodes_count =
549 fs->super->s_inodes_per_group;
550 fs->group_desc[i].bg_used_dirs_count = 0;
551 ext2fs_group_desc_csum_set(fs, i);
552
553 retval = ext2fs_allocate_group_table(fs, i, 0);
554 if (retval) goto errout;
555
556 group_block += fs->super->s_blocks_per_group;
557 }
558 retval = 0;
559
560 errout:
561 return (retval);
562 }
563
564 /*
565 * This routine adjusts the superblock and other data structures, both
566 * in disk as well as in memory...
567 */
adjust_superblock(ext2_resize_t rfs,blk_t new_size)568 static errcode_t adjust_superblock(ext2_resize_t rfs, blk_t new_size)
569 {
570 ext2_filsys fs;
571 int adj = 0;
572 errcode_t retval;
573 blk_t group_block;
574 unsigned long i;
575 unsigned long max_group;
576
577 fs = rfs->new_fs;
578 ext2fs_mark_super_dirty(fs);
579 ext2fs_mark_bb_dirty(fs);
580 ext2fs_mark_ib_dirty(fs);
581
582 retval = ext2fs_allocate_block_bitmap(fs, _("reserved blocks"),
583 &rfs->reserve_blocks);
584 if (retval)
585 return retval;
586
587 retval = adjust_fs_info(fs, rfs->old_fs, rfs->reserve_blocks, new_size);
588 if (retval)
589 goto errout;
590
591 /*
592 * Check to make sure there are enough inodes
593 */
594 if ((rfs->old_fs->super->s_inodes_count -
595 rfs->old_fs->super->s_free_inodes_count) >
596 rfs->new_fs->super->s_inodes_count) {
597 retval = ENOSPC;
598 goto errout;
599 }
600
601 /*
602 * If we are shrinking the number block groups, we're done and
603 * can exit now.
604 */
605 if (rfs->old_fs->group_desc_count > fs->group_desc_count) {
606 retval = 0;
607 goto errout;
608 }
609
610 /*
611 * If the number of block groups is staying the same, we're
612 * done and can exit now. (If the number block groups is
613 * shrinking, we had exited earlier.)
614 */
615 if (rfs->old_fs->group_desc_count >= fs->group_desc_count) {
616 retval = 0;
617 goto errout;
618 }
619
620 /*
621 * Initialize the new block group descriptors
622 */
623 retval = ext2fs_get_array(fs->blocksize, fs->inode_blocks_per_group,
624 &rfs->itable_buf);
625 if (retval)
626 goto errout;
627
628 memset(rfs->itable_buf, 0, fs->blocksize * fs->inode_blocks_per_group);
629 group_block = fs->super->s_first_data_block +
630 rfs->old_fs->group_desc_count * fs->super->s_blocks_per_group;
631
632 adj = rfs->old_fs->group_desc_count;
633 max_group = fs->group_desc_count - adj;
634 if (rfs->progress) {
635 retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
636 0, max_group);
637 if (retval)
638 goto errout;
639 }
640 for (i = rfs->old_fs->group_desc_count;
641 i < fs->group_desc_count; i++) {
642 /*
643 * Write out the new inode table
644 */
645 retval = io_channel_write_blk(fs->io,
646 fs->group_desc[i].bg_inode_table,
647 fs->inode_blocks_per_group,
648 rfs->itable_buf);
649 if (retval) goto errout;
650
651 io_channel_flush(fs->io);
652 if (rfs->progress) {
653 retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS,
654 i - adj + 1, max_group);
655 if (retval)
656 goto errout;
657 }
658 group_block += fs->super->s_blocks_per_group;
659 }
660 io_channel_flush(fs->io);
661 retval = 0;
662
663 errout:
664 return retval;
665 }
666
667 /* --------------------------------------------------------------------
668 *
669 * Resize processing, phase 2.
670 *
671 * In this phase we adjust determine which blocks need to be moved, in
672 * blocks_to_move(). We then copy the blocks to their ultimate new
673 * destinations using block_mover(). Since we are copying blocks to
674 * their new locations, again during this pass we can abort without
675 * any problems.
676 * --------------------------------------------------------------------
677 */
678
679 /*
680 * This helper function creates a block bitmap with all of the
681 * filesystem meta-data blocks.
682 */
mark_table_blocks(ext2_filsys fs,ext2fs_block_bitmap bmap)683 static errcode_t mark_table_blocks(ext2_filsys fs,
684 ext2fs_block_bitmap bmap)
685 {
686 blk_t b;
687 unsigned int j;
688 dgrp_t i;
689 unsigned long meta_bg_size;
690 unsigned int old_desc_blocks;
691
692 meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
693 if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
694 old_desc_blocks = fs->super->s_first_meta_bg;
695 else
696 old_desc_blocks = fs->desc_blocks +
697 fs->super->s_reserved_gdt_blocks;
698 for (i = 0; i < fs->group_desc_count; i++) {
699 ext2fs_reserve_super_and_bgd(fs, i, bmap);
700
701 /*
702 * Mark the blocks used for the inode table
703 */
704 for (j = 0, b = fs->group_desc[i].bg_inode_table;
705 j < (unsigned int) fs->inode_blocks_per_group;
706 j++, b++)
707 ext2fs_mark_block_bitmap(bmap, b);
708
709 /*
710 * Mark block used for the block bitmap
711 */
712 ext2fs_mark_block_bitmap(bmap,
713 fs->group_desc[i].bg_block_bitmap);
714
715 /*
716 * Mark block used for the inode bitmap
717 */
718 ext2fs_mark_block_bitmap(bmap,
719 fs->group_desc[i].bg_inode_bitmap);
720 }
721 return 0;
722 }
723
724 /*
725 * This function checks to see if a particular block (either a
726 * superblock or a block group descriptor) overlaps with an inode or
727 * block bitmap block, or with the inode table.
728 */
mark_fs_metablock(ext2_resize_t rfs,ext2fs_block_bitmap meta_bmap,int group,blk_t blk)729 static void mark_fs_metablock(ext2_resize_t rfs,
730 ext2fs_block_bitmap meta_bmap,
731 int group, blk_t blk)
732 {
733 ext2_filsys fs = rfs->new_fs;
734
735 ext2fs_mark_block_bitmap(rfs->reserve_blocks, blk);
736 ext2fs_block_alloc_stats(fs, blk, +1);
737
738 /*
739 * Check to see if we overlap with the inode or block bitmap,
740 * or the inode tables. If not, and the block is in use, then
741 * mark it as a block to be moved.
742 */
743 if (IS_BLOCK_BM(fs, group, blk)) {
744 FS_BLOCK_BM(fs, group) = 0;
745 rfs->needed_blocks++;
746 } else if (IS_INODE_BM(fs, group, blk)) {
747 FS_INODE_BM(fs, group) = 0;
748 rfs->needed_blocks++;
749 } else if (IS_INODE_TB(fs, group, blk)) {
750 FS_INODE_TB(fs, group) = 0;
751 rfs->needed_blocks++;
752 } else if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
753 EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
754 (fs->group_desc[group].bg_flags & EXT2_BG_BLOCK_UNINIT)) {
755 /*
756 * If the block bitmap is uninitialized, which means
757 * nothing other than standard metadata in use.
758 */
759 return;
760 } else if (ext2fs_test_block_bitmap(rfs->old_fs->block_map, blk) &&
761 !ext2fs_test_block_bitmap(meta_bmap, blk)) {
762 ext2fs_mark_block_bitmap(rfs->move_blocks, blk);
763 rfs->needed_blocks++;
764 }
765 }
766
767
768 /*
769 * This routine marks and unmarks reserved blocks in the new block
770 * bitmap. It also determines which blocks need to be moved and
771 * places this information into the move_blocks bitmap.
772 */
blocks_to_move(ext2_resize_t rfs)773 static errcode_t blocks_to_move(ext2_resize_t rfs)
774 {
775 int j, has_super;
776 dgrp_t i, max_groups, g;
777 blk_t blk, group_blk;
778 unsigned long old_blocks, new_blocks;
779 unsigned int meta_bg, meta_bg_size;
780 errcode_t retval;
781 ext2_filsys fs, old_fs;
782 ext2fs_block_bitmap meta_bmap;
783 __u32 save_incompat_flag;
784
785 fs = rfs->new_fs;
786 old_fs = rfs->old_fs;
787 if (old_fs->super->s_blocks_count > fs->super->s_blocks_count)
788 fs = rfs->old_fs;
789
790 retval = ext2fs_allocate_block_bitmap(fs, _("blocks to be moved"),
791 &rfs->move_blocks);
792 if (retval)
793 return retval;
794
795 retval = ext2fs_allocate_block_bitmap(fs, _("meta-data blocks"),
796 &meta_bmap);
797 if (retval)
798 return retval;
799
800 retval = mark_table_blocks(old_fs, meta_bmap);
801 if (retval)
802 return retval;
803
804 fs = rfs->new_fs;
805
806 /*
807 * If we're shrinking the filesystem, we need to move all of
808 * the blocks that don't fit any more
809 */
810 for (blk = fs->super->s_blocks_count;
811 blk < old_fs->super->s_blocks_count; blk++) {
812 g = ext2fs_group_of_blk(fs, blk);
813 if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
814 EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
815 (old_fs->group_desc[g].bg_flags & EXT2_BG_BLOCK_UNINIT)) {
816 /*
817 * The block bitmap is uninitialized, so skip
818 * to the next block group.
819 */
820 blk = ((g+1) * fs->super->s_blocks_per_group) +
821 fs->super->s_first_data_block - 1;
822 continue;
823 }
824 if (ext2fs_test_block_bitmap(old_fs->block_map, blk) &&
825 !ext2fs_test_block_bitmap(meta_bmap, blk)) {
826 ext2fs_mark_block_bitmap(rfs->move_blocks, blk);
827 rfs->needed_blocks++;
828 }
829 ext2fs_mark_block_bitmap(rfs->reserve_blocks, blk);
830 }
831
832 if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) {
833 old_blocks = old_fs->super->s_first_meta_bg;
834 new_blocks = fs->super->s_first_meta_bg;
835 } else {
836 old_blocks = old_fs->desc_blocks + old_fs->super->s_reserved_gdt_blocks;
837 new_blocks = fs->desc_blocks + fs->super->s_reserved_gdt_blocks;
838 }
839
840 if (old_blocks == new_blocks) {
841 retval = 0;
842 goto errout;
843 }
844
845 max_groups = fs->group_desc_count;
846 if (max_groups > old_fs->group_desc_count)
847 max_groups = old_fs->group_desc_count;
848 group_blk = old_fs->super->s_first_data_block;
849 /*
850 * If we're reducing the number of descriptor blocks, this
851 * makes life easy. :-) We just have to mark some extra
852 * blocks as free.
853 */
854 if (old_blocks > new_blocks) {
855 for (i = 0; i < max_groups; i++) {
856 if (!ext2fs_bg_has_super(fs, i)) {
857 group_blk += fs->super->s_blocks_per_group;
858 continue;
859 }
860 for (blk = group_blk+1+new_blocks;
861 blk < group_blk+1+old_blocks; blk++) {
862 ext2fs_block_alloc_stats(fs, blk, -1);
863 rfs->needed_blocks--;
864 }
865 group_blk += fs->super->s_blocks_per_group;
866 }
867 retval = 0;
868 goto errout;
869 }
870 /*
871 * If we're increasing the number of descriptor blocks, life
872 * gets interesting....
873 */
874 meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
875 for (i = 0; i < max_groups; i++) {
876 has_super = ext2fs_bg_has_super(fs, i);
877 if (has_super)
878 mark_fs_metablock(rfs, meta_bmap, i, group_blk);
879
880 meta_bg = i / meta_bg_size;
881 if (!(fs->super->s_feature_incompat &
882 EXT2_FEATURE_INCOMPAT_META_BG) ||
883 (meta_bg < fs->super->s_first_meta_bg)) {
884 if (has_super) {
885 for (blk = group_blk+1;
886 blk < group_blk + 1 + new_blocks; blk++)
887 mark_fs_metablock(rfs, meta_bmap,
888 i, blk);
889 }
890 } else {
891 if (has_super)
892 has_super = 1;
893 if (((i % meta_bg_size) == 0) ||
894 ((i % meta_bg_size) == 1) ||
895 ((i % meta_bg_size) == (meta_bg_size-1)))
896 mark_fs_metablock(rfs, meta_bmap, i,
897 group_blk + has_super);
898 }
899
900 if (fs->group_desc[i].bg_inode_table &&
901 fs->group_desc[i].bg_inode_bitmap &&
902 fs->group_desc[i].bg_block_bitmap)
903 goto next_group;
904
905 /*
906 * Reserve the existing meta blocks that we know
907 * aren't to be moved.
908 */
909 if (fs->group_desc[i].bg_block_bitmap)
910 ext2fs_mark_block_bitmap(rfs->reserve_blocks,
911 fs->group_desc[i].bg_block_bitmap);
912 if (fs->group_desc[i].bg_inode_bitmap)
913 ext2fs_mark_block_bitmap(rfs->reserve_blocks,
914 fs->group_desc[i].bg_inode_bitmap);
915 if (fs->group_desc[i].bg_inode_table)
916 for (blk = fs->group_desc[i].bg_inode_table, j=0;
917 j < fs->inode_blocks_per_group ; j++, blk++)
918 ext2fs_mark_block_bitmap(rfs->reserve_blocks,
919 blk);
920
921 /*
922 * Allocate the missing data structures
923 *
924 * XXX We have a problem with FLEX_BG and off-line
925 * resizing where we are growing the size of the
926 * filesystem. ext2fs_allocate_group_table() will try
927 * to reserve the inode table in the desired flex_bg
928 * location. However, passing rfs->reserve_blocks
929 * doesn't work since it only has reserved the blocks
930 * that will be used in the new block group -- and
931 * with flex_bg, we can and will allocate the tables
932 * outside of the block group. And we can't pass in
933 * the fs->block_map because it doesn't handle
934 * overlapping inode table movements right. So for
935 * now, we temporarily disable flex_bg to force
936 * ext2fs_allocate_group_tables() to allocate the bg
937 * metadata in side the block group, and the restore
938 * it afterwards. Ugly, until we can fix this up
939 * right later.
940 */
941 save_incompat_flag = fs->super->s_feature_incompat;
942 fs->super->s_feature_incompat &= ~EXT4_FEATURE_INCOMPAT_FLEX_BG;
943 retval = ext2fs_allocate_group_table(fs, i,
944 rfs->reserve_blocks);
945 fs->super->s_feature_incompat = save_incompat_flag;
946 if (retval)
947 goto errout;
948
949 /*
950 * For those structures that have changed, we need to
951 * do bookkeepping.
952 */
953 if (FS_BLOCK_BM(old_fs, i) !=
954 (blk = FS_BLOCK_BM(fs, i))) {
955 ext2fs_block_alloc_stats(fs, blk, +1);
956 if (ext2fs_test_block_bitmap(old_fs->block_map, blk) &&
957 !ext2fs_test_block_bitmap(meta_bmap, blk))
958 ext2fs_mark_block_bitmap(rfs->move_blocks,
959 blk);
960 }
961 if (FS_INODE_BM(old_fs, i) !=
962 (blk = FS_INODE_BM(fs, i))) {
963 ext2fs_block_alloc_stats(fs, blk, +1);
964 if (ext2fs_test_block_bitmap(old_fs->block_map, blk) &&
965 !ext2fs_test_block_bitmap(meta_bmap, blk))
966 ext2fs_mark_block_bitmap(rfs->move_blocks,
967 blk);
968 }
969
970 /*
971 * The inode table, if we need to relocate it, is
972 * handled specially. We have to reserve the blocks
973 * for both the old and the new inode table, since we
974 * can't have the inode table be destroyed during the
975 * block relocation phase.
976 */
977 if (FS_INODE_TB(fs, i) == FS_INODE_TB(old_fs, i))
978 goto next_group; /* inode table not moved */
979
980 rfs->needed_blocks += fs->inode_blocks_per_group;
981
982 /*
983 * Mark the new inode table as in use in the new block
984 * allocation bitmap, and move any blocks that might
985 * be necessary.
986 */
987 for (blk = fs->group_desc[i].bg_inode_table, j=0;
988 j < fs->inode_blocks_per_group ; j++, blk++) {
989 ext2fs_block_alloc_stats(fs, blk, +1);
990 if (ext2fs_test_block_bitmap(old_fs->block_map, blk) &&
991 !ext2fs_test_block_bitmap(meta_bmap, blk))
992 ext2fs_mark_block_bitmap(rfs->move_blocks,
993 blk);
994 }
995
996 /*
997 * Make sure the old inode table is reserved in the
998 * block reservation bitmap.
999 */
1000 for (blk = rfs->old_fs->group_desc[i].bg_inode_table, j=0;
1001 j < fs->inode_blocks_per_group ; j++, blk++)
1002 ext2fs_mark_block_bitmap(rfs->reserve_blocks, blk);
1003
1004 next_group:
1005 group_blk += rfs->new_fs->super->s_blocks_per_group;
1006 }
1007 retval = 0;
1008
1009 errout:
1010 if (meta_bmap)
1011 ext2fs_free_block_bitmap(meta_bmap);
1012
1013 return retval;
1014 }
1015
1016 /*
1017 * This helper function tries to allocate a new block. We try to
1018 * avoid hitting the original group descriptor blocks at least at
1019 * first, since we want to make it possible to recover from a badly
1020 * aborted resize operation as much as possible.
1021 *
1022 * In the future, I may further modify this routine to balance out
1023 * where we get the new blocks across the various block groups.
1024 * Ideally we would allocate blocks that corresponded with the block
1025 * group of the containing inode, and keep contiguous blocks
1026 * together. However, this very difficult to do efficiently, since we
1027 * don't have the necessary information up front.
1028 */
1029
1030 #define AVOID_OLD 1
1031 #define DESPERATION 2
1032
init_block_alloc(ext2_resize_t rfs)1033 static void init_block_alloc(ext2_resize_t rfs)
1034 {
1035 rfs->alloc_state = AVOID_OLD;
1036 rfs->new_blk = rfs->new_fs->super->s_first_data_block;
1037 #if 0
1038 /* HACK for testing */
1039 if (rfs->new_fs->super->s_blocks_count >
1040 rfs->old_fs->super->s_blocks_count)
1041 rfs->new_blk = rfs->old_fs->super->s_blocks_count;
1042 #endif
1043 }
1044
get_new_block(ext2_resize_t rfs)1045 static blk_t get_new_block(ext2_resize_t rfs)
1046 {
1047 ext2_filsys fs = rfs->new_fs;
1048
1049 while (1) {
1050 if (rfs->new_blk >= fs->super->s_blocks_count) {
1051 if (rfs->alloc_state == DESPERATION)
1052 return 0;
1053
1054 #ifdef RESIZE2FS_DEBUG
1055 if (rfs->flags & RESIZE_DEBUG_BMOVE)
1056 printf("Going into desperation mode "
1057 "for block allocations\n");
1058 #endif
1059 rfs->alloc_state = DESPERATION;
1060 rfs->new_blk = fs->super->s_first_data_block;
1061 continue;
1062 }
1063 if (ext2fs_test_block_bitmap(fs->block_map, rfs->new_blk) ||
1064 ext2fs_test_block_bitmap(rfs->reserve_blocks,
1065 rfs->new_blk) ||
1066 ((rfs->alloc_state == AVOID_OLD) &&
1067 (rfs->new_blk < rfs->old_fs->super->s_blocks_count) &&
1068 ext2fs_test_block_bitmap(rfs->old_fs->block_map,
1069 rfs->new_blk))) {
1070 rfs->new_blk++;
1071 continue;
1072 }
1073 return rfs->new_blk;
1074 }
1075 }
1076
resize2fs_get_alloc_block(ext2_filsys fs,blk64_t goal,blk64_t * ret)1077 static errcode_t resize2fs_get_alloc_block(ext2_filsys fs, blk64_t goal,
1078 blk64_t *ret)
1079 {
1080 ext2_resize_t rfs = (ext2_resize_t) fs->priv_data;
1081 blk_t blk;
1082
1083 blk = get_new_block(rfs);
1084 if (!blk)
1085 return ENOSPC;
1086
1087 #ifdef RESIZE2FS_DEBUG
1088 if (rfs->flags & 0xF)
1089 printf("get_alloc_block allocating %u\n", blk);
1090 #endif
1091
1092 ext2fs_mark_block_bitmap(rfs->old_fs->block_map, blk);
1093 ext2fs_mark_block_bitmap(rfs->new_fs->block_map, blk);
1094 *ret = (blk64_t) blk;
1095 return 0;
1096 }
1097
block_mover(ext2_resize_t rfs)1098 static errcode_t block_mover(ext2_resize_t rfs)
1099 {
1100 blk_t blk, old_blk, new_blk;
1101 ext2_filsys fs = rfs->new_fs;
1102 ext2_filsys old_fs = rfs->old_fs;
1103 errcode_t retval;
1104 int size, c;
1105 int to_move, moved;
1106 ext2_badblocks_list badblock_list = 0;
1107 int bb_modified = 0;
1108
1109 fs->get_alloc_block = resize2fs_get_alloc_block;
1110 old_fs->get_alloc_block = resize2fs_get_alloc_block;
1111
1112 retval = ext2fs_read_bb_inode(old_fs, &badblock_list);
1113 if (retval)
1114 return retval;
1115
1116 new_blk = fs->super->s_first_data_block;
1117 if (!rfs->itable_buf) {
1118 retval = ext2fs_get_array(fs->blocksize,
1119 fs->inode_blocks_per_group,
1120 &rfs->itable_buf);
1121 if (retval)
1122 return retval;
1123 }
1124 retval = ext2fs_create_extent_table(&rfs->bmap, 0);
1125 if (retval)
1126 return retval;
1127
1128 /*
1129 * The first step is to figure out where all of the blocks
1130 * will go.
1131 */
1132 to_move = moved = 0;
1133 init_block_alloc(rfs);
1134 for (blk = old_fs->super->s_first_data_block;
1135 blk < old_fs->super->s_blocks_count; blk++) {
1136 if (!ext2fs_test_block_bitmap(old_fs->block_map, blk))
1137 continue;
1138 if (!ext2fs_test_block_bitmap(rfs->move_blocks, blk))
1139 continue;
1140 if (ext2fs_badblocks_list_test(badblock_list, blk)) {
1141 ext2fs_badblocks_list_del(badblock_list, blk);
1142 bb_modified++;
1143 continue;
1144 }
1145
1146 new_blk = get_new_block(rfs);
1147 if (!new_blk) {
1148 retval = ENOSPC;
1149 goto errout;
1150 }
1151 ext2fs_block_alloc_stats(fs, new_blk, +1);
1152 ext2fs_add_extent_entry(rfs->bmap, blk, new_blk);
1153 to_move++;
1154 }
1155
1156 if (to_move == 0) {
1157 if (rfs->bmap) {
1158 ext2fs_free_extent_table(rfs->bmap);
1159 rfs->bmap = 0;
1160 }
1161 retval = 0;
1162 goto errout;
1163 }
1164
1165 /*
1166 * Step two is to actually move the blocks
1167 */
1168 retval = ext2fs_iterate_extent(rfs->bmap, 0, 0, 0);
1169 if (retval) goto errout;
1170
1171 if (rfs->progress) {
1172 retval = (rfs->progress)(rfs, E2_RSZ_BLOCK_RELOC_PASS,
1173 0, to_move);
1174 if (retval)
1175 goto errout;
1176 }
1177 while (1) {
1178 retval = ext2fs_iterate_extent(rfs->bmap, &old_blk, &new_blk, &size);
1179 if (retval) goto errout;
1180 if (!size)
1181 break;
1182 #ifdef RESIZE2FS_DEBUG
1183 if (rfs->flags & RESIZE_DEBUG_BMOVE)
1184 printf("Moving %d blocks %u->%u\n",
1185 size, old_blk, new_blk);
1186 #endif
1187 do {
1188 c = size;
1189 if (c > fs->inode_blocks_per_group)
1190 c = fs->inode_blocks_per_group;
1191 retval = io_channel_read_blk(fs->io, old_blk, c,
1192 rfs->itable_buf);
1193 if (retval) goto errout;
1194 retval = io_channel_write_blk(fs->io, new_blk, c,
1195 rfs->itable_buf);
1196 if (retval) goto errout;
1197 size -= c;
1198 new_blk += c;
1199 old_blk += c;
1200 moved += c;
1201 if (rfs->progress) {
1202 io_channel_flush(fs->io);
1203 retval = (rfs->progress)(rfs,
1204 E2_RSZ_BLOCK_RELOC_PASS,
1205 moved, to_move);
1206 if (retval)
1207 goto errout;
1208 }
1209 } while (size > 0);
1210 io_channel_flush(fs->io);
1211 }
1212
1213 errout:
1214 if (badblock_list) {
1215 if (!retval && bb_modified)
1216 retval = ext2fs_update_bb_inode(old_fs,
1217 badblock_list);
1218 ext2fs_badblocks_list_free(badblock_list);
1219 }
1220 return retval;
1221 }
1222
1223
1224 /* --------------------------------------------------------------------
1225 *
1226 * Resize processing, phase 3
1227 *
1228 * --------------------------------------------------------------------
1229 */
1230
1231
1232 struct process_block_struct {
1233 ext2_resize_t rfs;
1234 ext2_ino_t ino;
1235 struct ext2_inode * inode;
1236 errcode_t error;
1237 int is_dir;
1238 int changed;
1239 };
1240
process_block(ext2_filsys fs,blk_t * block_nr,e2_blkcnt_t blockcnt,blk_t ref_block EXT2FS_ATTR ((unused)),int ref_offset EXT2FS_ATTR ((unused)),void * priv_data)1241 static int process_block(ext2_filsys fs, blk_t *block_nr,
1242 e2_blkcnt_t blockcnt,
1243 blk_t ref_block EXT2FS_ATTR((unused)),
1244 int ref_offset EXT2FS_ATTR((unused)), void *priv_data)
1245 {
1246 struct process_block_struct *pb;
1247 errcode_t retval;
1248 blk_t block, new_block;
1249 int ret = 0;
1250
1251 pb = (struct process_block_struct *) priv_data;
1252 block = *block_nr;
1253 if (pb->rfs->bmap) {
1254 new_block = ext2fs_extent_translate(pb->rfs->bmap, block);
1255 if (new_block) {
1256 *block_nr = new_block;
1257 ret |= BLOCK_CHANGED;
1258 pb->changed = 1;
1259 #ifdef RESIZE2FS_DEBUG
1260 if (pb->rfs->flags & RESIZE_DEBUG_BMOVE)
1261 printf("ino=%u, blockcnt=%lld, %u->%u\n",
1262 pb->ino, blockcnt, block, new_block);
1263 #endif
1264 block = new_block;
1265 }
1266 }
1267 if (pb->is_dir) {
1268 retval = ext2fs_add_dir_block(fs->dblist, pb->ino,
1269 block, (int) blockcnt);
1270 if (retval) {
1271 pb->error = retval;
1272 ret |= BLOCK_ABORT;
1273 }
1274 }
1275 return ret;
1276 }
1277
1278 /*
1279 * Progress callback
1280 */
progress_callback(ext2_filsys fs,ext2_inode_scan scan EXT2FS_ATTR ((unused)),dgrp_t group,void * priv_data)1281 static errcode_t progress_callback(ext2_filsys fs,
1282 ext2_inode_scan scan EXT2FS_ATTR((unused)),
1283 dgrp_t group, void * priv_data)
1284 {
1285 ext2_resize_t rfs = (ext2_resize_t) priv_data;
1286 errcode_t retval;
1287
1288 /*
1289 * This check is to protect against old ext2 libraries. It
1290 * shouldn't be needed against new libraries.
1291 */
1292 if ((group+1) == 0)
1293 return 0;
1294
1295 if (rfs->progress) {
1296 io_channel_flush(fs->io);
1297 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
1298 group+1, fs->group_desc_count);
1299 if (retval)
1300 return retval;
1301 }
1302
1303 return 0;
1304 }
1305
inode_scan_and_fix(ext2_resize_t rfs)1306 static errcode_t inode_scan_and_fix(ext2_resize_t rfs)
1307 {
1308 struct process_block_struct pb;
1309 ext2_ino_t ino, new_inode;
1310 struct ext2_inode *inode = NULL;
1311 ext2_inode_scan scan = NULL;
1312 errcode_t retval;
1313 char *block_buf = 0;
1314 ext2_ino_t start_to_move;
1315 blk_t orig_size, new_block;
1316 int inode_size;
1317
1318 if ((rfs->old_fs->group_desc_count <=
1319 rfs->new_fs->group_desc_count) &&
1320 !rfs->bmap)
1321 return 0;
1322
1323 /*
1324 * Save the original size of the old filesystem, and
1325 * temporarily set the size to be the new size if the new size
1326 * is larger. We need to do this to avoid catching an error
1327 * by the block iterator routines
1328 */
1329 orig_size = rfs->old_fs->super->s_blocks_count;
1330 if (orig_size < rfs->new_fs->super->s_blocks_count)
1331 rfs->old_fs->super->s_blocks_count =
1332 rfs->new_fs->super->s_blocks_count;
1333
1334 retval = ext2fs_open_inode_scan(rfs->old_fs, 0, &scan);
1335 if (retval) goto errout;
1336
1337 retval = ext2fs_init_dblist(rfs->old_fs, 0);
1338 if (retval) goto errout;
1339 retval = ext2fs_get_array(rfs->old_fs->blocksize, 3, &block_buf);
1340 if (retval) goto errout;
1341
1342 start_to_move = (rfs->new_fs->group_desc_count *
1343 rfs->new_fs->super->s_inodes_per_group);
1344
1345 if (rfs->progress) {
1346 retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS,
1347 0, rfs->old_fs->group_desc_count);
1348 if (retval)
1349 goto errout;
1350 }
1351 ext2fs_set_inode_callback(scan, progress_callback, (void *) rfs);
1352 pb.rfs = rfs;
1353 pb.inode = inode;
1354 pb.error = 0;
1355 new_inode = EXT2_FIRST_INODE(rfs->new_fs->super);
1356 inode_size = EXT2_INODE_SIZE(rfs->new_fs->super);
1357 inode = malloc(inode_size);
1358 if (!inode) {
1359 retval = ENOMEM;
1360 goto errout;
1361 }
1362 /*
1363 * First, copy all of the inodes that need to be moved
1364 * elsewhere in the inode table
1365 */
1366 while (1) {
1367 retval = ext2fs_get_next_inode_full(scan, &ino, inode, inode_size);
1368 if (retval) goto errout;
1369 if (!ino)
1370 break;
1371
1372 if (inode->i_links_count == 0 && ino != EXT2_RESIZE_INO)
1373 continue; /* inode not in use */
1374
1375 pb.is_dir = LINUX_S_ISDIR(inode->i_mode);
1376 pb.changed = 0;
1377
1378 if (inode->i_file_acl && rfs->bmap) {
1379 new_block = ext2fs_extent_translate(rfs->bmap,
1380 inode->i_file_acl);
1381 if (new_block) {
1382 inode->i_file_acl = new_block;
1383 retval = ext2fs_write_inode_full(rfs->old_fs,
1384 ino, inode, inode_size);
1385 if (retval) goto errout;
1386 }
1387 }
1388
1389 if (ext2fs_inode_has_valid_blocks(inode) &&
1390 (rfs->bmap || pb.is_dir)) {
1391 pb.ino = ino;
1392 retval = ext2fs_block_iterate2(rfs->old_fs,
1393 ino, 0, block_buf,
1394 process_block, &pb);
1395 if (retval)
1396 goto errout;
1397 if (pb.error) {
1398 retval = pb.error;
1399 goto errout;
1400 }
1401 }
1402
1403 if (ino <= start_to_move)
1404 continue; /* Don't need to move it. */
1405
1406 /*
1407 * Find a new inode
1408 */
1409 retval = ext2fs_new_inode(rfs->new_fs, 0, 0, 0, &new_inode);
1410 if (retval)
1411 goto errout;
1412
1413 ext2fs_inode_alloc_stats2(rfs->new_fs, new_inode, +1,
1414 pb.is_dir);
1415 if (pb.changed) {
1416 /* Get the new version of the inode */
1417 retval = ext2fs_read_inode_full(rfs->old_fs, ino,
1418 inode, inode_size);
1419 if (retval) goto errout;
1420 }
1421 inode->i_ctime = time(0);
1422 retval = ext2fs_write_inode_full(rfs->old_fs, new_inode,
1423 inode, inode_size);
1424 if (retval) goto errout;
1425
1426 #ifdef RESIZE2FS_DEBUG
1427 if (rfs->flags & RESIZE_DEBUG_INODEMAP)
1428 printf("Inode moved %u->%u\n", ino, new_inode);
1429 #endif
1430 if (!rfs->imap) {
1431 retval = ext2fs_create_extent_table(&rfs->imap, 0);
1432 if (retval)
1433 goto errout;
1434 }
1435 ext2fs_add_extent_entry(rfs->imap, ino, new_inode);
1436 }
1437 io_channel_flush(rfs->old_fs->io);
1438
1439 errout:
1440 rfs->old_fs->super->s_blocks_count = orig_size;
1441 if (rfs->bmap) {
1442 ext2fs_free_extent_table(rfs->bmap);
1443 rfs->bmap = 0;
1444 }
1445 if (scan)
1446 ext2fs_close_inode_scan(scan);
1447 if (block_buf)
1448 ext2fs_free_mem(&block_buf);
1449 free(inode);
1450 return retval;
1451 }
1452
1453 /* --------------------------------------------------------------------
1454 *
1455 * Resize processing, phase 4.
1456 *
1457 * --------------------------------------------------------------------
1458 */
1459
1460 struct istruct {
1461 ext2_resize_t rfs;
1462 errcode_t err;
1463 unsigned int max_dirs;
1464 unsigned int num;
1465 };
1466
check_and_change_inodes(ext2_ino_t dir,int entry EXT2FS_ATTR ((unused)),struct ext2_dir_entry * dirent,int offset,int blocksize EXT2FS_ATTR ((unused)),char * buf EXT2FS_ATTR ((unused)),void * priv_data)1467 static int check_and_change_inodes(ext2_ino_t dir,
1468 int entry EXT2FS_ATTR((unused)),
1469 struct ext2_dir_entry *dirent, int offset,
1470 int blocksize EXT2FS_ATTR((unused)),
1471 char *buf EXT2FS_ATTR((unused)),
1472 void *priv_data)
1473 {
1474 struct istruct *is = (struct istruct *) priv_data;
1475 struct ext2_inode inode;
1476 ext2_ino_t new_inode;
1477 errcode_t retval;
1478
1479 if (is->rfs->progress && offset == 0) {
1480 io_channel_flush(is->rfs->old_fs->io);
1481 is->err = (is->rfs->progress)(is->rfs,
1482 E2_RSZ_INODE_REF_UPD_PASS,
1483 ++is->num, is->max_dirs);
1484 if (is->err)
1485 return DIRENT_ABORT;
1486 }
1487
1488 if (!dirent->inode)
1489 return 0;
1490
1491 new_inode = ext2fs_extent_translate(is->rfs->imap, dirent->inode);
1492
1493 if (!new_inode)
1494 return 0;
1495 #ifdef RESIZE2FS_DEBUG
1496 if (is->rfs->flags & RESIZE_DEBUG_INODEMAP)
1497 printf("Inode translate (dir=%u, name=%.*s, %u->%u)\n",
1498 dir, dirent->name_len&0xFF, dirent->name,
1499 dirent->inode, new_inode);
1500 #endif
1501
1502 dirent->inode = new_inode;
1503
1504 /* Update the directory mtime and ctime */
1505 retval = ext2fs_read_inode(is->rfs->old_fs, dir, &inode);
1506 if (retval == 0) {
1507 inode.i_mtime = inode.i_ctime = time(0);
1508 is->err = ext2fs_write_inode(is->rfs->old_fs, dir, &inode);
1509 if (is->err)
1510 return DIRENT_ABORT;
1511 }
1512
1513 return DIRENT_CHANGED;
1514 }
1515
inode_ref_fix(ext2_resize_t rfs)1516 static errcode_t inode_ref_fix(ext2_resize_t rfs)
1517 {
1518 errcode_t retval;
1519 struct istruct is;
1520
1521 if (!rfs->imap)
1522 return 0;
1523
1524 /*
1525 * Now, we iterate over all of the directories to update the
1526 * inode references
1527 */
1528 is.num = 0;
1529 is.max_dirs = ext2fs_dblist_count(rfs->old_fs->dblist);
1530 is.rfs = rfs;
1531 is.err = 0;
1532
1533 if (rfs->progress) {
1534 retval = (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS,
1535 0, is.max_dirs);
1536 if (retval)
1537 goto errout;
1538 }
1539
1540 retval = ext2fs_dblist_dir_iterate(rfs->old_fs->dblist,
1541 DIRENT_FLAG_INCLUDE_EMPTY, 0,
1542 check_and_change_inodes, &is);
1543 if (retval)
1544 goto errout;
1545 if (is.err) {
1546 retval = is.err;
1547 goto errout;
1548 }
1549
1550 if (rfs->progress && (is.num < is.max_dirs))
1551 (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS,
1552 is.max_dirs, is.max_dirs);
1553
1554 errout:
1555 ext2fs_free_extent_table(rfs->imap);
1556 rfs->imap = 0;
1557 return retval;
1558 }
1559
1560
1561 /* --------------------------------------------------------------------
1562 *
1563 * Resize processing, phase 5.
1564 *
1565 * In this phase we actually move the inode table around, and then
1566 * update the summary statistics. This is scary, since aborting here
1567 * will potentially scramble the filesystem. (We are moving the
1568 * inode tables around in place, and so the potential for lost data,
1569 * or at the very least scrambling the mapping between filenames and
1570 * inode numbers is very high in case of a power failure here.)
1571 * --------------------------------------------------------------------
1572 */
1573
1574
1575 /*
1576 * A very scary routine --- this one moves the inode table around!!!
1577 *
1578 * After this you have to use the rfs->new_fs file handle to read and
1579 * write inodes.
1580 */
move_itables(ext2_resize_t rfs)1581 static errcode_t move_itables(ext2_resize_t rfs)
1582 {
1583 int n, num, size, diff;
1584 dgrp_t i, max_groups;
1585 ext2_filsys fs = rfs->new_fs;
1586 char *cp;
1587 blk_t old_blk, new_blk, blk;
1588 errcode_t retval;
1589 int j, to_move, moved;
1590
1591 max_groups = fs->group_desc_count;
1592 if (max_groups > rfs->old_fs->group_desc_count)
1593 max_groups = rfs->old_fs->group_desc_count;
1594
1595 size = fs->blocksize * fs->inode_blocks_per_group;
1596 if (!rfs->itable_buf) {
1597 retval = ext2fs_get_mem(size, &rfs->itable_buf);
1598 if (retval)
1599 return retval;
1600 }
1601
1602 /*
1603 * Figure out how many inode tables we need to move
1604 */
1605 to_move = moved = 0;
1606 for (i=0; i < max_groups; i++)
1607 if (rfs->old_fs->group_desc[i].bg_inode_table !=
1608 fs->group_desc[i].bg_inode_table)
1609 to_move++;
1610
1611 if (to_move == 0)
1612 return 0;
1613
1614 if (rfs->progress) {
1615 retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
1616 0, to_move);
1617 if (retval)
1618 goto errout;
1619 }
1620
1621 rfs->old_fs->flags |= EXT2_FLAG_MASTER_SB_ONLY;
1622
1623 for (i=0; i < max_groups; i++) {
1624 old_blk = rfs->old_fs->group_desc[i].bg_inode_table;
1625 new_blk = fs->group_desc[i].bg_inode_table;
1626 diff = new_blk - old_blk;
1627
1628 #ifdef RESIZE2FS_DEBUG
1629 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1630 printf("Itable move group %d block %u->%u (diff %d)\n",
1631 i, old_blk, new_blk, diff);
1632 #endif
1633
1634 if (!diff)
1635 continue;
1636
1637 retval = io_channel_read_blk(fs->io, old_blk,
1638 fs->inode_blocks_per_group,
1639 rfs->itable_buf);
1640 if (retval)
1641 goto errout;
1642 /*
1643 * The end of the inode table segment often contains
1644 * all zeros, and we're often only moving the inode
1645 * table down a block or two. If so, we can optimize
1646 * things by not rewriting blocks that we know to be zero
1647 * already.
1648 */
1649 for (cp = rfs->itable_buf+size-1, n=0; n < size; n++, cp--)
1650 if (*cp)
1651 break;
1652 n = n >> EXT2_BLOCK_SIZE_BITS(fs->super);
1653 #ifdef RESIZE2FS_DEBUG
1654 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1655 printf("%d blocks of zeros...\n", n);
1656 #endif
1657 num = fs->inode_blocks_per_group;
1658 if (n > diff)
1659 num -= n;
1660
1661 retval = io_channel_write_blk(fs->io, new_blk,
1662 num, rfs->itable_buf);
1663 if (retval) {
1664 io_channel_write_blk(fs->io, old_blk,
1665 num, rfs->itable_buf);
1666 goto errout;
1667 }
1668 if (n > diff) {
1669 retval = io_channel_write_blk(fs->io,
1670 old_blk + fs->inode_blocks_per_group,
1671 diff, (rfs->itable_buf +
1672 (fs->inode_blocks_per_group - diff) *
1673 fs->blocksize));
1674 if (retval)
1675 goto errout;
1676 }
1677
1678 for (blk = rfs->old_fs->group_desc[i].bg_inode_table, j=0;
1679 j < fs->inode_blocks_per_group ; j++, blk++)
1680 ext2fs_block_alloc_stats(fs, blk, -1);
1681
1682 rfs->old_fs->group_desc[i].bg_inode_table = new_blk;
1683 ext2fs_group_desc_csum_set(rfs->old_fs, i);
1684 ext2fs_mark_super_dirty(rfs->old_fs);
1685 ext2fs_flush(rfs->old_fs);
1686
1687 if (rfs->progress) {
1688 retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS,
1689 ++moved, to_move);
1690 if (retval)
1691 goto errout;
1692 }
1693 }
1694 mark_table_blocks(fs, fs->block_map);
1695 ext2fs_flush(fs);
1696 #ifdef RESIZE2FS_DEBUG
1697 if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE)
1698 printf("Inode table move finished.\n");
1699 #endif
1700 return 0;
1701
1702 errout:
1703 return retval;
1704 }
1705
1706 /*
1707 * Fix the resize inode
1708 */
fix_resize_inode(ext2_filsys fs)1709 static errcode_t fix_resize_inode(ext2_filsys fs)
1710 {
1711 struct ext2_inode inode;
1712 errcode_t retval;
1713 char * block_buf;
1714 blk_t blk;
1715
1716 if (!(fs->super->s_feature_compat &
1717 EXT2_FEATURE_COMPAT_RESIZE_INODE))
1718 return 0;
1719
1720 retval = ext2fs_get_mem(fs->blocksize, &block_buf);
1721 if (retval) goto errout;
1722
1723 retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode);
1724 if (retval) goto errout;
1725
1726 if (fs->super->s_reserved_gdt_blocks == 0) {
1727 fs->super->s_feature_compat &=
1728 ~EXT2_FEATURE_COMPAT_RESIZE_INODE;
1729 ext2fs_mark_super_dirty(fs);
1730
1731 if ((blk = inode.i_block[EXT2_DIND_BLOCK]) != 0)
1732 ext2fs_block_alloc_stats(fs, blk, -1);
1733
1734 memset(&inode, 0, sizeof(inode));
1735
1736 retval = ext2fs_write_inode(fs, EXT2_RESIZE_INO, &inode);
1737 goto errout;
1738 }
1739
1740 ext2fs_iblk_set(fs, &inode, 1);
1741
1742 retval = ext2fs_write_inode(fs, EXT2_RESIZE_INO, &inode);
1743 if (retval) goto errout;
1744
1745 if (!inode.i_block[EXT2_DIND_BLOCK]) {
1746 /*
1747 * Avoid zeroing out block #0; that's rude. This
1748 * should never happen anyway since the filesystem
1749 * should be fsck'ed and we assume it is consistent.
1750 */
1751 fprintf(stderr,
1752 _("Should never happen: resize inode corrupt!\n"));
1753 exit(1);
1754 }
1755
1756 memset(block_buf, 0, fs->blocksize);
1757
1758 retval = io_channel_write_blk(fs->io, inode.i_block[EXT2_DIND_BLOCK],
1759 1, block_buf);
1760 if (retval) goto errout;
1761
1762 retval = ext2fs_create_resize_inode(fs);
1763 if (retval)
1764 goto errout;
1765
1766 errout:
1767 if (block_buf)
1768 ext2fs_free_mem(&block_buf);
1769 return retval;
1770 }
1771
1772 /*
1773 * Finally, recalculate the summary information
1774 */
ext2fs_calculate_summary_stats(ext2_filsys fs)1775 static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs)
1776 {
1777 blk_t blk;
1778 ext2_ino_t ino;
1779 unsigned int group = 0;
1780 unsigned int count = 0;
1781 int total_free = 0;
1782 int group_free = 0;
1783 int uninit = 0;
1784 blk_t super_blk, old_desc_blk, new_desc_blk;
1785 int old_desc_blocks;
1786
1787 /*
1788 * First calculate the block statistics
1789 */
1790 uninit = fs->group_desc[group].bg_flags & EXT2_BG_BLOCK_UNINIT;
1791 ext2fs_super_and_bgd_loc(fs, group, &super_blk, &old_desc_blk,
1792 &new_desc_blk, 0);
1793 if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
1794 old_desc_blocks = fs->super->s_first_meta_bg;
1795 else
1796 old_desc_blocks = fs->desc_blocks +
1797 fs->super->s_reserved_gdt_blocks;
1798 for (blk = fs->super->s_first_data_block;
1799 blk < fs->super->s_blocks_count; blk++) {
1800 if ((uninit &&
1801 !((blk == super_blk) ||
1802 ((old_desc_blk && old_desc_blocks &&
1803 (blk >= old_desc_blk) &&
1804 (blk < old_desc_blk + old_desc_blocks))) ||
1805 ((new_desc_blk && (blk == new_desc_blk))) ||
1806 (blk == fs->group_desc[group].bg_block_bitmap) ||
1807 (blk == fs->group_desc[group].bg_inode_bitmap) ||
1808 ((blk >= fs->group_desc[group].bg_inode_table &&
1809 (blk < fs->group_desc[group].bg_inode_table
1810 + fs->inode_blocks_per_group))))) ||
1811 (!ext2fs_fast_test_block_bitmap(fs->block_map, blk))) {
1812 group_free++;
1813 total_free++;
1814 }
1815 count++;
1816 if ((count == fs->super->s_blocks_per_group) ||
1817 (blk == fs->super->s_blocks_count-1)) {
1818 fs->group_desc[group].bg_free_blocks_count =
1819 group_free;
1820 ext2fs_group_desc_csum_set(fs, group);
1821 group++;
1822 if (group >= fs->group_desc_count)
1823 break;
1824 count = 0;
1825 group_free = 0;
1826 uninit = (fs->group_desc[group].bg_flags &
1827 EXT2_BG_BLOCK_UNINIT);
1828 ext2fs_super_and_bgd_loc(fs, group, &super_blk,
1829 &old_desc_blk,
1830 &new_desc_blk, 0);
1831 if (fs->super->s_feature_incompat &
1832 EXT2_FEATURE_INCOMPAT_META_BG)
1833 old_desc_blocks = fs->super->s_first_meta_bg;
1834 else
1835 old_desc_blocks = fs->desc_blocks +
1836 fs->super->s_reserved_gdt_blocks;
1837 }
1838 }
1839 fs->super->s_free_blocks_count = total_free;
1840
1841 /*
1842 * Next, calculate the inode statistics
1843 */
1844 group_free = 0;
1845 total_free = 0;
1846 count = 0;
1847 group = 0;
1848
1849 /* Protect loop from wrap-around if s_inodes_count maxed */
1850 uninit = fs->group_desc[group].bg_flags & EXT2_BG_INODE_UNINIT;
1851 for (ino = 1; ino <= fs->super->s_inodes_count && ino > 0; ino++) {
1852 if (uninit ||
1853 !ext2fs_fast_test_inode_bitmap(fs->inode_map, ino)) {
1854 group_free++;
1855 total_free++;
1856 }
1857 count++;
1858 if ((count == fs->super->s_inodes_per_group) ||
1859 (ino == fs->super->s_inodes_count)) {
1860 fs->group_desc[group].bg_free_inodes_count =
1861 group_free;
1862 ext2fs_group_desc_csum_set(fs, group);
1863 group++;
1864 if (group >= fs->group_desc_count)
1865 break;
1866 count = 0;
1867 group_free = 0;
1868 uninit = (fs->group_desc[group].bg_flags &
1869 EXT2_BG_INODE_UNINIT);
1870 }
1871 }
1872 fs->super->s_free_inodes_count = total_free;
1873 ext2fs_mark_super_dirty(fs);
1874 return 0;
1875 }
1876
1877 /*
1878 * Journal may have been relocated; update the backup journal blocks
1879 * in the superblock.
1880 */
fix_sb_journal_backup(ext2_filsys fs)1881 static errcode_t fix_sb_journal_backup(ext2_filsys fs)
1882 {
1883 errcode_t retval;
1884 struct ext2_inode inode;
1885
1886 if (!(fs->super->s_feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1887 return 0;
1888
1889 /* External journal? Nothing to do. */
1890 if (fs->super->s_journal_dev && !fs->super->s_journal_inum)
1891 return 0;
1892
1893 retval = ext2fs_read_inode(fs, fs->super->s_journal_inum, &inode);
1894 if (retval)
1895 return retval;
1896 memcpy(fs->super->s_jnl_blocks, inode.i_block, EXT2_N_BLOCKS*4);
1897 fs->super->s_jnl_blocks[16] = inode.i_size;
1898 fs->super->s_jnl_backup_type = EXT3_JNL_BACKUP_BLOCKS;
1899 ext2fs_mark_super_dirty(fs);
1900 return 0;
1901 }
1902
1903 /*
1904 * calcluate the minimum number of blocks the given fs can be resized to
1905 */
calculate_minimum_resize_size(ext2_filsys fs)1906 blk_t calculate_minimum_resize_size(ext2_filsys fs)
1907 {
1908 blk_t inode_count, blks_needed, groups, data_blocks;
1909 blk_t grp, data_needed, last_start;
1910 int overhead = 0, num_of_superblocks = 0;
1911 int extra_groups = 0;
1912 int flexbg_size = 1 << fs->super->s_log_groups_per_flex;
1913
1914 /*
1915 * first figure out how many group descriptors we need to
1916 * handle the number of inodes we have
1917 */
1918 inode_count = fs->super->s_inodes_count -
1919 fs->super->s_free_inodes_count;
1920 blks_needed = ext2fs_div_ceil(inode_count,
1921 fs->super->s_inodes_per_group) *
1922 EXT2_BLOCKS_PER_GROUP(fs->super);
1923 groups = ext2fs_div_ceil(blks_needed,
1924 EXT2_BLOCKS_PER_GROUP(fs->super));
1925
1926 /*
1927 * we need to figure out how many backup superblocks we have so we can
1928 * account for that in the metadata
1929 */
1930 for (grp = 0; grp < fs->group_desc_count; grp++) {
1931 if (ext2fs_bg_has_super(fs, grp))
1932 num_of_superblocks++;
1933 }
1934
1935 /* calculate how many blocks are needed for data */
1936 data_needed = fs->super->s_blocks_count -
1937 fs->super->s_free_blocks_count;
1938 data_needed -= SUPER_OVERHEAD(fs) * num_of_superblocks;
1939 data_needed -= META_OVERHEAD(fs) * fs->group_desc_count;
1940
1941 if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_FLEX_BG) {
1942 /*
1943 * For ext4 we need to allow for up to a flex_bg worth
1944 * of inode tables of slack space so the resize
1945 * operation can be guaranteed to finish.
1946 */
1947 extra_groups = flexbg_size - (groups & (flexbg_size - 1));
1948 data_needed += META_OVERHEAD(fs) * extra_groups;
1949 extra_groups = groups % flexbg_size;
1950 }
1951
1952 /*
1953 * figure out how many data blocks we have given the number of groups
1954 * we need for our inodes
1955 */
1956 data_blocks = groups * EXT2_BLOCKS_PER_GROUP(fs->super);
1957 last_start = 0;
1958 for (grp = 0; grp < groups; grp++) {
1959 overhead = META_OVERHEAD(fs);
1960
1961 if (ext2fs_bg_has_super(fs, grp))
1962 overhead += SUPER_OVERHEAD(fs);
1963
1964 /*
1965 * we want to keep track of how much data we can store in
1966 * the groups leading up to the last group so we can determine
1967 * how big the last group needs to be
1968 */
1969 if (grp != (groups - 1))
1970 last_start += EXT2_BLOCKS_PER_GROUP(fs->super) -
1971 overhead;
1972
1973 data_blocks -= overhead;
1974 }
1975
1976 /*
1977 * if we need more group descriptors in order to accomodate our data
1978 * then we need to add them here
1979 */
1980 while (data_needed > data_blocks) {
1981 blk_t remainder = data_needed - data_blocks;
1982 blk_t extra_grps;
1983
1984 /* figure out how many more groups we need for the data */
1985 extra_grps = ext2fs_div_ceil(remainder,
1986 EXT2_BLOCKS_PER_GROUP(fs->super));
1987
1988 data_blocks += extra_grps * EXT2_BLOCKS_PER_GROUP(fs->super);
1989
1990 /* ok we have to account for the last group */
1991 overhead = META_OVERHEAD(fs);
1992 if (ext2fs_bg_has_super(fs, groups-1))
1993 overhead += SUPER_OVERHEAD(fs);
1994 last_start += EXT2_BLOCKS_PER_GROUP(fs->super) - overhead;
1995
1996 for (grp = groups; grp < groups+extra_grps; grp++) {
1997 overhead = META_OVERHEAD(fs);
1998 if (ext2fs_bg_has_super(fs, grp))
1999 overhead += SUPER_OVERHEAD(fs);
2000
2001 /*
2002 * again, we need to see how much data we cram into
2003 * all of the groups leading up to the last group
2004 */
2005 if (grp != (groups + extra_grps - 1))
2006 last_start += EXT2_BLOCKS_PER_GROUP(fs->super)
2007 - overhead;
2008
2009 data_blocks -= overhead;
2010 }
2011
2012 groups += extra_grps;
2013 extra_groups += extra_grps;
2014 if (fs->super->s_feature_incompat
2015 & EXT4_FEATURE_INCOMPAT_FLEX_BG
2016 && extra_groups > flexbg_size) {
2017 /*
2018 * For ext4 we need to allow for up to a flex_bg worth
2019 * of inode tables of slack space so the resize
2020 * operation can be guaranteed to finish.
2021 */
2022 extra_groups = flexbg_size -
2023 (groups & (flexbg_size - 1));
2024 data_needed += META_OVERHEAD(fs) * extra_groups;
2025 extra_groups = groups % flexbg_size;
2026 }
2027 }
2028
2029 /* now for the fun voodoo */
2030 overhead = META_OVERHEAD(fs);
2031
2032 /*
2033 * if this is the case then the last group is going to have data in it
2034 * so we need to adjust the size of the last group accordingly
2035 */
2036 if (last_start < data_needed) {
2037 blk_t remainder = data_needed - last_start;
2038
2039 /*
2040 * 50 is a magic number that mkfs/resize uses to see if its
2041 * even worth making/resizing the fs. basically you need to
2042 * have at least 50 blocks in addition to the blocks needed
2043 * for the metadata in the last group
2044 */
2045 if (remainder > 50)
2046 overhead += remainder;
2047 else
2048 overhead += 50;
2049 } else
2050 overhead += 50;
2051
2052 if (ext2fs_bg_has_super(fs, groups-1))
2053 overhead += SUPER_OVERHEAD(fs);
2054
2055 /*
2056 * since our last group doesn't have to be BLOCKS_PER_GROUP large, we
2057 * only do groups-1, and then add the number of blocks needed to
2058 * handle the group descriptor metadata+data that we need
2059 */
2060 blks_needed = (groups-1) * EXT2_BLOCKS_PER_GROUP(fs->super);
2061 blks_needed += overhead;
2062
2063 /*
2064 * If at this point we've already added up more "needed" than
2065 * the current size, just return current size as minimum.
2066 */
2067 if (blks_needed >= fs->super->s_blocks_count)
2068 return fs->super->s_blocks_count;
2069 /*
2070 * We need to reserve a few extra blocks if extents are
2071 * enabled, in case we need to grow the extent tree. The more
2072 * we shrink the file system, the more space we need.
2073 */
2074 if (fs->super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_EXTENTS)
2075 blks_needed += (fs->super->s_blocks_count - blks_needed)/500;
2076
2077 return blks_needed;
2078 }
2079