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14#include <linux/time.h>
15#include <linux/capability.h>
16#include <linux/fs.h>
17#include <linux/jbd2.h>
18#include <linux/quotaops.h>
19#include <linux/buffer_head.h>
20#include "ext4.h"
21#include "ext4_jbd2.h"
22#include "mballoc.h"
23
24
25
26
27
28
29
30
31void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
32 ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp)
33{
34 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
35 ext4_grpblk_t offset;
36
37 blocknr = blocknr - le32_to_cpu(es->s_first_data_block);
38 offset = do_div(blocknr, EXT4_BLOCKS_PER_GROUP(sb));
39 if (offsetp)
40 *offsetp = offset;
41 if (blockgrpp)
42 *blockgrpp = blocknr;
43
44}
45
46static int ext4_block_in_group(struct super_block *sb, ext4_fsblk_t block,
47 ext4_group_t block_group)
48{
49 ext4_group_t actual_group;
50 ext4_get_group_no_and_offset(sb, block, &actual_group, NULL);
51 if (actual_group == block_group)
52 return 1;
53 return 0;
54}
55
56static int ext4_group_used_meta_blocks(struct super_block *sb,
57 ext4_group_t block_group,
58 struct ext4_group_desc *gdp)
59{
60 ext4_fsblk_t tmp;
61 struct ext4_sb_info *sbi = EXT4_SB(sb);
62
63 int used_blocks = sbi->s_itb_per_group + 2;
64
65 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG)) {
66 if (!ext4_block_in_group(sb, ext4_block_bitmap(sb, gdp),
67 block_group))
68 used_blocks--;
69
70 if (!ext4_block_in_group(sb, ext4_inode_bitmap(sb, gdp),
71 block_group))
72 used_blocks--;
73
74 tmp = ext4_inode_table(sb, gdp);
75 for (; tmp < ext4_inode_table(sb, gdp) +
76 sbi->s_itb_per_group; tmp++) {
77 if (!ext4_block_in_group(sb, tmp, block_group))
78 used_blocks -= 1;
79 }
80 }
81 return used_blocks;
82}
83
84
85
86unsigned ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh,
87 ext4_group_t block_group, struct ext4_group_desc *gdp)
88{
89 int bit, bit_max;
90 ext4_group_t ngroups = ext4_get_groups_count(sb);
91 unsigned free_blocks, group_blocks;
92 struct ext4_sb_info *sbi = EXT4_SB(sb);
93
94 if (bh) {
95 J_ASSERT_BH(bh, buffer_locked(bh));
96
97
98
99 if (!ext4_group_desc_csum_verify(sbi, block_group, gdp)) {
100 ext4_error(sb, "Checksum bad for group %u",
101 block_group);
102 ext4_free_blks_set(sb, gdp, 0);
103 ext4_free_inodes_set(sb, gdp, 0);
104 ext4_itable_unused_set(sb, gdp, 0);
105 memset(bh->b_data, 0xff, sb->s_blocksize);
106 return 0;
107 }
108 memset(bh->b_data, 0, sb->s_blocksize);
109 }
110
111
112 bit_max = ext4_bg_has_super(sb, block_group);
113
114 if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
115 block_group < le32_to_cpu(sbi->s_es->s_first_meta_bg) *
116 sbi->s_desc_per_block) {
117 if (bit_max) {
118 bit_max += ext4_bg_num_gdb(sb, block_group);
119 bit_max +=
120 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks);
121 }
122 } else {
123 bit_max += ext4_bg_num_gdb(sb, block_group);
124 }
125
126 if (block_group == ngroups - 1) {
127
128
129
130
131
132 group_blocks = ext4_blocks_count(sbi->s_es) -
133 ext4_group_first_block_no(sb, ngroups - 1);
134 } else {
135 group_blocks = EXT4_BLOCKS_PER_GROUP(sb);
136 }
137
138 free_blocks = group_blocks - bit_max;
139
140 if (bh) {
141 ext4_fsblk_t start, tmp;
142 int flex_bg = 0;
143
144 for (bit = 0; bit < bit_max; bit++)
145 ext4_set_bit(bit, bh->b_data);
146
147 start = ext4_group_first_block_no(sb, block_group);
148
149 if (EXT4_HAS_INCOMPAT_FEATURE(sb,
150 EXT4_FEATURE_INCOMPAT_FLEX_BG))
151 flex_bg = 1;
152
153
154 tmp = ext4_block_bitmap(sb, gdp);
155 if (!flex_bg || ext4_block_in_group(sb, tmp, block_group))
156 ext4_set_bit(tmp - start, bh->b_data);
157
158 tmp = ext4_inode_bitmap(sb, gdp);
159 if (!flex_bg || ext4_block_in_group(sb, tmp, block_group))
160 ext4_set_bit(tmp - start, bh->b_data);
161
162 tmp = ext4_inode_table(sb, gdp);
163 for (; tmp < ext4_inode_table(sb, gdp) +
164 sbi->s_itb_per_group; tmp++) {
165 if (!flex_bg ||
166 ext4_block_in_group(sb, tmp, block_group))
167 ext4_set_bit(tmp - start, bh->b_data);
168 }
169
170
171
172
173
174 ext4_mark_bitmap_end(group_blocks, sb->s_blocksize * 8,
175 bh->b_data);
176 }
177 return free_blocks - ext4_group_used_meta_blocks(sb, block_group, gdp);
178}
179
180
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196
197
198
199struct ext4_group_desc * ext4_get_group_desc(struct super_block *sb,
200 ext4_group_t block_group,
201 struct buffer_head **bh)
202{
203 unsigned int group_desc;
204 unsigned int offset;
205 ext4_group_t ngroups = ext4_get_groups_count(sb);
206 struct ext4_group_desc *desc;
207 struct ext4_sb_info *sbi = EXT4_SB(sb);
208
209 if (block_group >= ngroups) {
210 ext4_error(sb, "block_group >= groups_count - block_group = %u,"
211 " groups_count = %u", block_group, ngroups);
212
213 return NULL;
214 }
215
216 group_desc = block_group >> EXT4_DESC_PER_BLOCK_BITS(sb);
217 offset = block_group & (EXT4_DESC_PER_BLOCK(sb) - 1);
218 if (!sbi->s_group_desc[group_desc]) {
219 ext4_error(sb, "Group descriptor not loaded - "
220 "block_group = %u, group_desc = %u, desc = %u",
221 block_group, group_desc, offset);
222 return NULL;
223 }
224
225 desc = (struct ext4_group_desc *)(
226 (__u8 *)sbi->s_group_desc[group_desc]->b_data +
227 offset * EXT4_DESC_SIZE(sb));
228 if (bh)
229 *bh = sbi->s_group_desc[group_desc];
230 return desc;
231}
232
233static int ext4_valid_block_bitmap(struct super_block *sb,
234 struct ext4_group_desc *desc,
235 unsigned int block_group,
236 struct buffer_head *bh)
237{
238 ext4_grpblk_t offset;
239 ext4_grpblk_t next_zero_bit;
240 ext4_fsblk_t bitmap_blk;
241 ext4_fsblk_t group_first_block;
242
243 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG)) {
244
245
246
247
248
249
250 return 1;
251 }
252 group_first_block = ext4_group_first_block_no(sb, block_group);
253
254
255 bitmap_blk = ext4_block_bitmap(sb, desc);
256 offset = bitmap_blk - group_first_block;
257 if (!ext4_test_bit(offset, bh->b_data))
258
259 goto err_out;
260
261
262 bitmap_blk = ext4_inode_bitmap(sb, desc);
263 offset = bitmap_blk - group_first_block;
264 if (!ext4_test_bit(offset, bh->b_data))
265
266 goto err_out;
267
268
269 bitmap_blk = ext4_inode_table(sb, desc);
270 offset = bitmap_blk - group_first_block;
271 next_zero_bit = ext4_find_next_zero_bit(bh->b_data,
272 offset + EXT4_SB(sb)->s_itb_per_group,
273 offset);
274 if (next_zero_bit >= offset + EXT4_SB(sb)->s_itb_per_group)
275
276 return 1;
277
278err_out:
279 ext4_error(sb, "Invalid block bitmap - block_group = %d, block = %llu",
280 block_group, bitmap_blk);
281 return 0;
282}
283
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290
291
292
293struct buffer_head *
294ext4_read_block_bitmap(struct super_block *sb, ext4_group_t block_group)
295{
296 struct ext4_group_desc *desc;
297 struct buffer_head *bh = NULL;
298 ext4_fsblk_t bitmap_blk;
299
300 desc = ext4_get_group_desc(sb, block_group, NULL);
301 if (!desc)
302 return NULL;
303 bitmap_blk = ext4_block_bitmap(sb, desc);
304 bh = sb_getblk(sb, bitmap_blk);
305 if (unlikely(!bh)) {
306 ext4_error(sb, "Cannot read block bitmap - "
307 "block_group = %u, block_bitmap = %llu",
308 block_group, bitmap_blk);
309 return NULL;
310 }
311
312 if (bitmap_uptodate(bh))
313 return bh;
314
315 lock_buffer(bh);
316 if (bitmap_uptodate(bh)) {
317 unlock_buffer(bh);
318 return bh;
319 }
320 ext4_lock_group(sb, block_group);
321 if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
322 ext4_init_block_bitmap(sb, bh, block_group, desc);
323 set_bitmap_uptodate(bh);
324 set_buffer_uptodate(bh);
325 ext4_unlock_group(sb, block_group);
326 unlock_buffer(bh);
327 return bh;
328 }
329 ext4_unlock_group(sb, block_group);
330 if (buffer_uptodate(bh)) {
331
332
333
334
335 set_bitmap_uptodate(bh);
336 unlock_buffer(bh);
337 return bh;
338 }
339
340
341
342
343
344
345 set_bitmap_uptodate(bh);
346 if (bh_submit_read(bh) < 0) {
347 put_bh(bh);
348 ext4_error(sb, "Cannot read block bitmap - "
349 "block_group = %u, block_bitmap = %llu",
350 block_group, bitmap_blk);
351 return NULL;
352 }
353 ext4_valid_block_bitmap(sb, desc, block_group, bh);
354
355
356
357
358 return bh;
359}
360
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369
370
371
372void ext4_add_groupblocks(handle_t *handle, struct super_block *sb,
373 ext4_fsblk_t block, unsigned long count)
374{
375 struct buffer_head *bitmap_bh = NULL;
376 struct buffer_head *gd_bh;
377 ext4_group_t block_group;
378 ext4_grpblk_t bit;
379 unsigned int i;
380 struct ext4_group_desc *desc;
381 struct ext4_sb_info *sbi = EXT4_SB(sb);
382 int err = 0, ret, blk_free_count;
383 ext4_grpblk_t blocks_freed;
384 struct ext4_group_info *grp;
385
386 ext4_debug("Adding block(s) %llu-%llu\n", block, block + count - 1);
387
388 ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
389 grp = ext4_get_group_info(sb, block_group);
390
391
392
393
394 if (bit + count > EXT4_BLOCKS_PER_GROUP(sb)) {
395 goto error_return;
396 }
397 bitmap_bh = ext4_read_block_bitmap(sb, block_group);
398 if (!bitmap_bh)
399 goto error_return;
400 desc = ext4_get_group_desc(sb, block_group, &gd_bh);
401 if (!desc)
402 goto error_return;
403
404 if (in_range(ext4_block_bitmap(sb, desc), block, count) ||
405 in_range(ext4_inode_bitmap(sb, desc), block, count) ||
406 in_range(block, ext4_inode_table(sb, desc), sbi->s_itb_per_group) ||
407 in_range(block + count - 1, ext4_inode_table(sb, desc),
408 sbi->s_itb_per_group)) {
409 ext4_error(sb, "Adding blocks in system zones - "
410 "Block = %llu, count = %lu",
411 block, count);
412 goto error_return;
413 }
414
415
416
417
418
419 BUFFER_TRACE(bitmap_bh, "getting undo access");
420 err = ext4_journal_get_undo_access(handle, bitmap_bh);
421 if (err)
422 goto error_return;
423
424
425
426
427
428
429 BUFFER_TRACE(gd_bh, "get_write_access");
430 err = ext4_journal_get_write_access(handle, gd_bh);
431 if (err)
432 goto error_return;
433
434
435
436
437 down_write(&grp->alloc_sem);
438 for (i = 0, blocks_freed = 0; i < count; i++) {
439 BUFFER_TRACE(bitmap_bh, "clear bit");
440 if (!ext4_clear_bit_atomic(ext4_group_lock_ptr(sb, block_group),
441 bit + i, bitmap_bh->b_data)) {
442 ext4_error(sb, "bit already cleared for block %llu",
443 (ext4_fsblk_t)(block + i));
444 BUFFER_TRACE(bitmap_bh, "bit already cleared");
445 } else {
446 blocks_freed++;
447 }
448 }
449 ext4_lock_group(sb, block_group);
450 blk_free_count = blocks_freed + ext4_free_blks_count(sb, desc);
451 ext4_free_blks_set(sb, desc, blk_free_count);
452 desc->bg_checksum = ext4_group_desc_csum(sbi, block_group, desc);
453 ext4_unlock_group(sb, block_group);
454 percpu_counter_add(&sbi->s_freeblocks_counter, blocks_freed);
455
456 if (sbi->s_log_groups_per_flex) {
457 ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
458 atomic_add(blocks_freed,
459 &sbi->s_flex_groups[flex_group].free_blocks);
460 }
461
462
463
464
465 set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state));
466 grp->bb_free += blocks_freed;
467 up_write(&grp->alloc_sem);
468
469
470 BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
471 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
472
473
474 BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
475 ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh);
476 if (!err)
477 err = ret;
478
479error_return:
480 brelse(bitmap_bh);
481 ext4_std_error(sb, err);
482 return;
483}
484
485
486
487
488
489
490
491
492
493static int ext4_has_free_blocks(struct ext4_sb_info *sbi, s64 nblocks)
494{
495 s64 free_blocks, dirty_blocks, root_blocks;
496 struct percpu_counter *fbc = &sbi->s_freeblocks_counter;
497 struct percpu_counter *dbc = &sbi->s_dirtyblocks_counter;
498
499 free_blocks = percpu_counter_read_positive(fbc);
500 dirty_blocks = percpu_counter_read_positive(dbc);
501 root_blocks = ext4_r_blocks_count(sbi->s_es);
502
503 if (free_blocks - (nblocks + root_blocks + dirty_blocks) <
504 EXT4_FREEBLOCKS_WATERMARK) {
505 free_blocks = percpu_counter_sum_positive(fbc);
506 dirty_blocks = percpu_counter_sum_positive(dbc);
507 if (dirty_blocks < 0) {
508 printk(KERN_CRIT "Dirty block accounting "
509 "went wrong %lld\n",
510 (long long)dirty_blocks);
511 }
512 }
513
514
515
516 if (free_blocks >= ((root_blocks + nblocks) + dirty_blocks))
517 return 1;
518
519
520 if (sbi->s_resuid == current_fsuid() ||
521 ((sbi->s_resgid != 0) && in_group_p(sbi->s_resgid)) ||
522 capable(CAP_SYS_RESOURCE)) {
523 if (free_blocks >= (nblocks + dirty_blocks))
524 return 1;
525 }
526
527 return 0;
528}
529
530int ext4_claim_free_blocks(struct ext4_sb_info *sbi,
531 s64 nblocks)
532{
533 if (ext4_has_free_blocks(sbi, nblocks)) {
534 percpu_counter_add(&sbi->s_dirtyblocks_counter, nblocks);
535 return 0;
536 } else
537 return -ENOSPC;
538}
539
540
541
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543
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548
549
550
551
552int ext4_should_retry_alloc(struct super_block *sb, int *retries)
553{
554 if (!ext4_has_free_blocks(EXT4_SB(sb), 1) ||
555 (*retries)++ > 3 ||
556 !EXT4_SB(sb)->s_journal)
557 return 0;
558
559 jbd_debug(1, "%s: retrying operation after ENOSPC\n", sb->s_id);
560
561 return jbd2_journal_force_commit_nested(EXT4_SB(sb)->s_journal);
562}
563
564
565
566
567
568
569
570
571
572
573
574
575
576ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
577 ext4_fsblk_t goal, unsigned long *count, int *errp)
578{
579 struct ext4_allocation_request ar;
580 ext4_fsblk_t ret;
581
582 memset(&ar, 0, sizeof(ar));
583
584 ar.inode = inode;
585 ar.goal = goal;
586 ar.len = count ? *count : 1;
587
588 ret = ext4_mb_new_blocks(handle, &ar, errp);
589 if (count)
590 *count = ar.len;
591
592
593
594
595 if (!(*errp) &&
596 ext4_test_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED)) {
597 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
598 EXT4_I(inode)->i_allocated_meta_blocks += ar.len;
599 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
600 dquot_alloc_block_nofail(inode, ar.len);
601 }
602 return ret;
603}
604
605
606
607
608
609
610
611ext4_fsblk_t ext4_count_free_blocks(struct super_block *sb)
612{
613 ext4_fsblk_t desc_count;
614 struct ext4_group_desc *gdp;
615 ext4_group_t i;
616 ext4_group_t ngroups = ext4_get_groups_count(sb);
617#ifdef EXT4FS_DEBUG
618 struct ext4_super_block *es;
619 ext4_fsblk_t bitmap_count;
620 unsigned int x;
621 struct buffer_head *bitmap_bh = NULL;
622
623 es = EXT4_SB(sb)->s_es;
624 desc_count = 0;
625 bitmap_count = 0;
626 gdp = NULL;
627
628 for (i = 0; i < ngroups; i++) {
629 gdp = ext4_get_group_desc(sb, i, NULL);
630 if (!gdp)
631 continue;
632 desc_count += ext4_free_blks_count(sb, gdp);
633 brelse(bitmap_bh);
634 bitmap_bh = ext4_read_block_bitmap(sb, i);
635 if (bitmap_bh == NULL)
636 continue;
637
638 x = ext4_count_free(bitmap_bh, sb->s_blocksize);
639 printk(KERN_DEBUG "group %u: stored = %d, counted = %u\n",
640 i, ext4_free_blks_count(sb, gdp), x);
641 bitmap_count += x;
642 }
643 brelse(bitmap_bh);
644 printk(KERN_DEBUG "ext4_count_free_blocks: stored = %llu"
645 ", computed = %llu, %llu\n", ext4_free_blocks_count(es),
646 desc_count, bitmap_count);
647 return bitmap_count;
648#else
649 desc_count = 0;
650 for (i = 0; i < ngroups; i++) {
651 gdp = ext4_get_group_desc(sb, i, NULL);
652 if (!gdp)
653 continue;
654 desc_count += ext4_free_blks_count(sb, gdp);
655 }
656
657 return desc_count;
658#endif
659}
660
661static inline int test_root(ext4_group_t a, int b)
662{
663 int num = b;
664
665 while (a > num)
666 num *= b;
667 return num == a;
668}
669
670static int ext4_group_sparse(ext4_group_t group)
671{
672 if (group <= 1)
673 return 1;
674 if (!(group & 1))
675 return 0;
676 return (test_root(group, 7) || test_root(group, 5) ||
677 test_root(group, 3));
678}
679
680
681
682
683
684
685
686
687
688int ext4_bg_has_super(struct super_block *sb, ext4_group_t group)
689{
690 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
691 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER) &&
692 !ext4_group_sparse(group))
693 return 0;
694 return 1;
695}
696
697static unsigned long ext4_bg_num_gdb_meta(struct super_block *sb,
698 ext4_group_t group)
699{
700 unsigned long metagroup = group / EXT4_DESC_PER_BLOCK(sb);
701 ext4_group_t first = metagroup * EXT4_DESC_PER_BLOCK(sb);
702 ext4_group_t last = first + EXT4_DESC_PER_BLOCK(sb) - 1;
703
704 if (group == first || group == first + 1 || group == last)
705 return 1;
706 return 0;
707}
708
709static unsigned long ext4_bg_num_gdb_nometa(struct super_block *sb,
710 ext4_group_t group)
711{
712 if (!ext4_bg_has_super(sb, group))
713 return 0;
714
715 if (EXT4_HAS_INCOMPAT_FEATURE(sb,EXT4_FEATURE_INCOMPAT_META_BG))
716 return le32_to_cpu(EXT4_SB(sb)->s_es->s_first_meta_bg);
717 else
718 return EXT4_SB(sb)->s_gdb_count;
719}
720
721
722
723
724
725
726
727
728
729
730unsigned long ext4_bg_num_gdb(struct super_block *sb, ext4_group_t group)
731{
732 unsigned long first_meta_bg =
733 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_meta_bg);
734 unsigned long metagroup = group / EXT4_DESC_PER_BLOCK(sb);
735
736 if (!EXT4_HAS_INCOMPAT_FEATURE(sb,EXT4_FEATURE_INCOMPAT_META_BG) ||
737 metagroup < first_meta_bg)
738 return ext4_bg_num_gdb_nometa(sb, group);
739
740 return ext4_bg_num_gdb_meta(sb,group);
741
742}
743
744