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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#include <trace/events/ext4.h>
25
26static unsigned ext4_num_base_meta_clusters(struct super_block *sb,
27 ext4_group_t block_group);
28
29
30
31
32
33
34
35ext4_group_t ext4_get_group_number(struct super_block *sb,
36 ext4_fsblk_t block)
37{
38 ext4_group_t group;
39
40 if (test_opt2(sb, STD_GROUP_SIZE))
41 group = (block -
42 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) >>
43 (EXT4_BLOCK_SIZE_BITS(sb) + EXT4_CLUSTER_BITS(sb) + 3);
44 else
45 ext4_get_group_no_and_offset(sb, block, &group, NULL);
46 return group;
47}
48
49
50
51
52
53void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
54 ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp)
55{
56 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
57 ext4_grpblk_t offset;
58
59 blocknr = blocknr - le32_to_cpu(es->s_first_data_block);
60 offset = do_div(blocknr, EXT4_BLOCKS_PER_GROUP(sb)) >>
61 EXT4_SB(sb)->s_cluster_bits;
62 if (offsetp)
63 *offsetp = offset;
64 if (blockgrpp)
65 *blockgrpp = blocknr;
66
67}
68
69
70
71
72
73static inline int ext4_block_in_group(struct super_block *sb,
74 ext4_fsblk_t block,
75 ext4_group_t block_group)
76{
77 ext4_group_t actual_group;
78
79 actual_group = ext4_get_group_number(sb, block);
80 return (actual_group == block_group) ? 1 : 0;
81}
82
83
84
85
86unsigned ext4_num_overhead_clusters(struct super_block *sb,
87 ext4_group_t block_group,
88 struct ext4_group_desc *gdp)
89{
90 unsigned num_clusters;
91 int block_cluster = -1, inode_cluster = -1, itbl_cluster = -1, i, c;
92 ext4_fsblk_t start = ext4_group_first_block_no(sb, block_group);
93 ext4_fsblk_t itbl_blk;
94 struct ext4_sb_info *sbi = EXT4_SB(sb);
95
96
97
98
99 num_clusters = ext4_num_base_meta_clusters(sb, block_group);
100
101
102
103
104
105
106
107
108
109
110
111
112
113 if (ext4_block_in_group(sb, ext4_block_bitmap(sb, gdp), block_group)) {
114 block_cluster = EXT4_B2C(sbi,
115 ext4_block_bitmap(sb, gdp) - start);
116 if (block_cluster < num_clusters)
117 block_cluster = -1;
118 else if (block_cluster == num_clusters) {
119 num_clusters++;
120 block_cluster = -1;
121 }
122 }
123
124 if (ext4_block_in_group(sb, ext4_inode_bitmap(sb, gdp), block_group)) {
125 inode_cluster = EXT4_B2C(sbi,
126 ext4_inode_bitmap(sb, gdp) - start);
127 if (inode_cluster < num_clusters)
128 inode_cluster = -1;
129 else if (inode_cluster == num_clusters) {
130 num_clusters++;
131 inode_cluster = -1;
132 }
133 }
134
135 itbl_blk = ext4_inode_table(sb, gdp);
136 for (i = 0; i < sbi->s_itb_per_group; i++) {
137 if (ext4_block_in_group(sb, itbl_blk + i, block_group)) {
138 c = EXT4_B2C(sbi, itbl_blk + i - start);
139 if ((c < num_clusters) || (c == inode_cluster) ||
140 (c == block_cluster) || (c == itbl_cluster))
141 continue;
142 if (c == num_clusters) {
143 num_clusters++;
144 continue;
145 }
146 num_clusters++;
147 itbl_cluster = c;
148 }
149 }
150
151 if (block_cluster != -1)
152 num_clusters++;
153 if (inode_cluster != -1)
154 num_clusters++;
155
156 return num_clusters;
157}
158
159static unsigned int num_clusters_in_group(struct super_block *sb,
160 ext4_group_t block_group)
161{
162 unsigned int blocks;
163
164 if (block_group == ext4_get_groups_count(sb) - 1) {
165
166
167
168
169
170
171 blocks = ext4_blocks_count(EXT4_SB(sb)->s_es) -
172 ext4_group_first_block_no(sb, block_group);
173 } else
174 blocks = EXT4_BLOCKS_PER_GROUP(sb);
175 return EXT4_NUM_B2C(EXT4_SB(sb), blocks);
176}
177
178
179void ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh,
180 ext4_group_t block_group,
181 struct ext4_group_desc *gdp)
182{
183 unsigned int bit, bit_max;
184 struct ext4_sb_info *sbi = EXT4_SB(sb);
185 ext4_fsblk_t start, tmp;
186 int flex_bg = 0;
187
188 J_ASSERT_BH(bh, buffer_locked(bh));
189
190
191
192 if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) {
193 ext4_error(sb, "Checksum bad for group %u", block_group);
194 ext4_free_group_clusters_set(sb, gdp, 0);
195 ext4_free_inodes_set(sb, gdp, 0);
196 ext4_itable_unused_set(sb, gdp, 0);
197 memset(bh->b_data, 0xff, sb->s_blocksize);
198 ext4_block_bitmap_csum_set(sb, block_group, gdp, bh);
199 return;
200 }
201 memset(bh->b_data, 0, sb->s_blocksize);
202
203 bit_max = ext4_num_base_meta_clusters(sb, block_group);
204 for (bit = 0; bit < bit_max; bit++)
205 ext4_set_bit(bit, bh->b_data);
206
207 start = ext4_group_first_block_no(sb, block_group);
208
209 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
210 flex_bg = 1;
211
212
213 tmp = ext4_block_bitmap(sb, gdp);
214 if (!flex_bg || ext4_block_in_group(sb, tmp, block_group))
215 ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data);
216
217 tmp = ext4_inode_bitmap(sb, gdp);
218 if (!flex_bg || ext4_block_in_group(sb, tmp, block_group))
219 ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data);
220
221 tmp = ext4_inode_table(sb, gdp);
222 for (; tmp < ext4_inode_table(sb, gdp) +
223 sbi->s_itb_per_group; tmp++) {
224 if (!flex_bg || ext4_block_in_group(sb, tmp, block_group))
225 ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data);
226 }
227
228
229
230
231
232
233 ext4_mark_bitmap_end(num_clusters_in_group(sb, block_group),
234 sb->s_blocksize * 8, bh->b_data);
235 ext4_block_bitmap_csum_set(sb, block_group, gdp, bh);
236 ext4_group_desc_csum_set(sb, block_group, gdp);
237}
238
239
240
241
242unsigned ext4_free_clusters_after_init(struct super_block *sb,
243 ext4_group_t block_group,
244 struct ext4_group_desc *gdp)
245{
246 return num_clusters_in_group(sb, block_group) -
247 ext4_num_overhead_clusters(sb, block_group, gdp);
248}
249
250
251
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255
256
257
258
259
260
261
262
263
264
265
266
267
268struct ext4_group_desc * ext4_get_group_desc(struct super_block *sb,
269 ext4_group_t block_group,
270 struct buffer_head **bh)
271{
272 unsigned int group_desc;
273 unsigned int offset;
274 ext4_group_t ngroups = ext4_get_groups_count(sb);
275 struct ext4_group_desc *desc;
276 struct ext4_sb_info *sbi = EXT4_SB(sb);
277
278 if (block_group >= ngroups) {
279 ext4_error(sb, "block_group >= groups_count - block_group = %u,"
280 " groups_count = %u", block_group, ngroups);
281
282 return NULL;
283 }
284
285 group_desc = block_group >> EXT4_DESC_PER_BLOCK_BITS(sb);
286 offset = block_group & (EXT4_DESC_PER_BLOCK(sb) - 1);
287 if (!sbi->s_group_desc[group_desc]) {
288 ext4_error(sb, "Group descriptor not loaded - "
289 "block_group = %u, group_desc = %u, desc = %u",
290 block_group, group_desc, offset);
291 return NULL;
292 }
293
294 desc = (struct ext4_group_desc *)(
295 (__u8 *)sbi->s_group_desc[group_desc]->b_data +
296 offset * EXT4_DESC_SIZE(sb));
297 if (bh)
298 *bh = sbi->s_group_desc[group_desc];
299 return desc;
300}
301
302
303
304
305
306static ext4_fsblk_t ext4_valid_block_bitmap(struct super_block *sb,
307 struct ext4_group_desc *desc,
308 unsigned int block_group,
309 struct buffer_head *bh)
310{
311 ext4_grpblk_t offset;
312 ext4_grpblk_t next_zero_bit;
313 ext4_fsblk_t blk;
314 ext4_fsblk_t group_first_block;
315
316 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG)) {
317
318
319
320
321
322
323 return 0;
324 }
325 group_first_block = ext4_group_first_block_no(sb, block_group);
326
327
328 blk = ext4_block_bitmap(sb, desc);
329 offset = blk - group_first_block;
330 if (!ext4_test_bit(offset, bh->b_data))
331
332 return blk;
333
334
335 blk = ext4_inode_bitmap(sb, desc);
336 offset = blk - group_first_block;
337 if (!ext4_test_bit(offset, bh->b_data))
338
339 return blk;
340
341
342 blk = ext4_inode_table(sb, desc);
343 offset = blk - group_first_block;
344 next_zero_bit = ext4_find_next_zero_bit(bh->b_data,
345 offset + EXT4_SB(sb)->s_itb_per_group,
346 offset);
347 if (next_zero_bit < offset + EXT4_SB(sb)->s_itb_per_group)
348
349 return blk;
350 return 0;
351}
352
353void ext4_validate_block_bitmap(struct super_block *sb,
354 struct ext4_group_desc *desc,
355 unsigned int block_group,
356 struct buffer_head *bh)
357{
358 ext4_fsblk_t blk;
359
360 if (buffer_verified(bh))
361 return;
362
363 ext4_lock_group(sb, block_group);
364 blk = ext4_valid_block_bitmap(sb, desc, block_group, bh);
365 if (unlikely(blk != 0)) {
366 ext4_unlock_group(sb, block_group);
367 ext4_error(sb, "bg %u: block %llu: invalid block bitmap",
368 block_group, blk);
369 return;
370 }
371 if (unlikely(!ext4_block_bitmap_csum_verify(sb, block_group,
372 desc, bh))) {
373 ext4_unlock_group(sb, block_group);
374 ext4_error(sb, "bg %u: bad block bitmap checksum", block_group);
375 return;
376 }
377 set_buffer_verified(bh);
378 ext4_unlock_group(sb, block_group);
379}
380
381
382
383
384
385
386
387
388
389
390
391struct buffer_head *
392ext4_read_block_bitmap_nowait(struct super_block *sb, ext4_group_t block_group)
393{
394 struct ext4_group_desc *desc;
395 struct buffer_head *bh;
396 ext4_fsblk_t bitmap_blk;
397
398 desc = ext4_get_group_desc(sb, block_group, NULL);
399 if (!desc)
400 return NULL;
401 bitmap_blk = ext4_block_bitmap(sb, desc);
402 bh = sb_getblk(sb, bitmap_blk);
403 if (unlikely(!bh)) {
404 ext4_error(sb, "Cannot get buffer for block bitmap - "
405 "block_group = %u, block_bitmap = %llu",
406 block_group, bitmap_blk);
407 return NULL;
408 }
409
410 if (bitmap_uptodate(bh))
411 goto verify;
412
413 lock_buffer(bh);
414 if (bitmap_uptodate(bh)) {
415 unlock_buffer(bh);
416 goto verify;
417 }
418 ext4_lock_group(sb, block_group);
419 if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
420 ext4_init_block_bitmap(sb, bh, block_group, desc);
421 set_bitmap_uptodate(bh);
422 set_buffer_uptodate(bh);
423 ext4_unlock_group(sb, block_group);
424 unlock_buffer(bh);
425 return bh;
426 }
427 ext4_unlock_group(sb, block_group);
428 if (buffer_uptodate(bh)) {
429
430
431
432
433 set_bitmap_uptodate(bh);
434 unlock_buffer(bh);
435 goto verify;
436 }
437
438
439
440 set_buffer_new(bh);
441 trace_ext4_read_block_bitmap_load(sb, block_group);
442 bh->b_end_io = ext4_end_bitmap_read;
443 get_bh(bh);
444 submit_bh(READ | REQ_META | REQ_PRIO, bh);
445 return bh;
446verify:
447 ext4_validate_block_bitmap(sb, desc, block_group, bh);
448 return bh;
449}
450
451
452int ext4_wait_block_bitmap(struct super_block *sb, ext4_group_t block_group,
453 struct buffer_head *bh)
454{
455 struct ext4_group_desc *desc;
456
457 if (!buffer_new(bh))
458 return 0;
459 desc = ext4_get_group_desc(sb, block_group, NULL);
460 if (!desc)
461 return 1;
462 wait_on_buffer(bh);
463 if (!buffer_uptodate(bh)) {
464 ext4_error(sb, "Cannot read block bitmap - "
465 "block_group = %u, block_bitmap = %llu",
466 block_group, (unsigned long long) bh->b_blocknr);
467 return 1;
468 }
469 clear_buffer_new(bh);
470
471 ext4_validate_block_bitmap(sb, desc, block_group, bh);
472 return 0;
473}
474
475struct buffer_head *
476ext4_read_block_bitmap(struct super_block *sb, ext4_group_t block_group)
477{
478 struct buffer_head *bh;
479
480 bh = ext4_read_block_bitmap_nowait(sb, block_group);
481 if (!bh)
482 return NULL;
483 if (ext4_wait_block_bitmap(sb, block_group, bh)) {
484 put_bh(bh);
485 return NULL;
486 }
487 return bh;
488}
489
490
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493
494
495
496
497
498
499static int ext4_has_free_clusters(struct ext4_sb_info *sbi,
500 s64 nclusters, unsigned int flags)
501{
502 s64 free_clusters, dirty_clusters, rsv, resv_clusters;
503 struct percpu_counter *fcc = &sbi->s_freeclusters_counter;
504 struct percpu_counter *dcc = &sbi->s_dirtyclusters_counter;
505
506 free_clusters = percpu_counter_read_positive(fcc);
507 dirty_clusters = percpu_counter_read_positive(dcc);
508 resv_clusters = atomic64_read(&sbi->s_resv_clusters);
509
510
511
512
513
514 rsv = (ext4_r_blocks_count(sbi->s_es) >> sbi->s_cluster_bits) +
515 resv_clusters;
516
517 if (free_clusters - (nclusters + rsv + dirty_clusters) <
518 EXT4_FREECLUSTERS_WATERMARK) {
519 free_clusters = percpu_counter_sum_positive(fcc);
520 dirty_clusters = percpu_counter_sum_positive(dcc);
521 }
522
523
524
525 if (free_clusters >= (rsv + nclusters + dirty_clusters))
526 return 1;
527
528
529 if (uid_eq(sbi->s_resuid, current_fsuid()) ||
530 (!gid_eq(sbi->s_resgid, GLOBAL_ROOT_GID) && in_group_p(sbi->s_resgid)) ||
531 capable(CAP_SYS_RESOURCE) ||
532 (flags & EXT4_MB_USE_ROOT_BLOCKS)) {
533
534 if (free_clusters >= (nclusters + dirty_clusters +
535 resv_clusters))
536 return 1;
537 }
538
539 if (flags & EXT4_MB_USE_RESERVED) {
540 if (free_clusters >= (nclusters + dirty_clusters))
541 return 1;
542 }
543
544 return 0;
545}
546
547int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
548 s64 nclusters, unsigned int flags)
549{
550 if (ext4_has_free_clusters(sbi, nclusters, flags)) {
551 percpu_counter_add(&sbi->s_dirtyclusters_counter, nclusters);
552 return 0;
553 } else
554 return -ENOSPC;
555}
556
557
558
559
560
561
562
563
564
565
566
567
568
569int ext4_should_retry_alloc(struct super_block *sb, int *retries)
570{
571 if (!ext4_has_free_clusters(EXT4_SB(sb), 1, 0) ||
572 (*retries)++ > 3 ||
573 !EXT4_SB(sb)->s_journal)
574 return 0;
575
576 jbd_debug(1, "%s: retrying operation after ENOSPC\n", sb->s_id);
577
578 return jbd2_journal_force_commit_nested(EXT4_SB(sb)->s_journal);
579}
580
581
582
583
584
585
586
587
588
589
590
591
592
593ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
594 ext4_fsblk_t goal, unsigned int flags,
595 unsigned long *count, int *errp)
596{
597 struct ext4_allocation_request ar;
598 ext4_fsblk_t ret;
599
600 memset(&ar, 0, sizeof(ar));
601
602 ar.inode = inode;
603 ar.goal = goal;
604 ar.len = count ? *count : 1;
605 ar.flags = flags;
606
607 ret = ext4_mb_new_blocks(handle, &ar, errp);
608 if (count)
609 *count = ar.len;
610
611
612
613
614 if (!(*errp) &&
615 ext4_test_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED)) {
616 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
617 EXT4_I(inode)->i_allocated_meta_blocks += ar.len;
618 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
619 dquot_alloc_block_nofail(inode,
620 EXT4_C2B(EXT4_SB(inode->i_sb), ar.len));
621 }
622 return ret;
623}
624
625
626
627
628
629
630
631ext4_fsblk_t ext4_count_free_clusters(struct super_block *sb)
632{
633 ext4_fsblk_t desc_count;
634 struct ext4_group_desc *gdp;
635 ext4_group_t i;
636 ext4_group_t ngroups = ext4_get_groups_count(sb);
637#ifdef EXT4FS_DEBUG
638 struct ext4_super_block *es;
639 ext4_fsblk_t bitmap_count;
640 unsigned int x;
641 struct buffer_head *bitmap_bh = NULL;
642
643 es = EXT4_SB(sb)->s_es;
644 desc_count = 0;
645 bitmap_count = 0;
646 gdp = NULL;
647
648 for (i = 0; i < ngroups; i++) {
649 gdp = ext4_get_group_desc(sb, i, NULL);
650 if (!gdp)
651 continue;
652 desc_count += ext4_free_group_clusters(sb, gdp);
653 brelse(bitmap_bh);
654 bitmap_bh = ext4_read_block_bitmap(sb, i);
655 if (bitmap_bh == NULL)
656 continue;
657
658 x = ext4_count_free(bitmap_bh->b_data,
659 EXT4_BLOCKS_PER_GROUP(sb) / 8);
660 printk(KERN_DEBUG "group %u: stored = %d, counted = %u\n",
661 i, ext4_free_group_clusters(sb, gdp), x);
662 bitmap_count += x;
663 }
664 brelse(bitmap_bh);
665 printk(KERN_DEBUG "ext4_count_free_clusters: stored = %llu"
666 ", computed = %llu, %llu\n",
667 EXT4_NUM_B2C(EXT4_SB(sb), ext4_free_blocks_count(es)),
668 desc_count, bitmap_count);
669 return bitmap_count;
670#else
671 desc_count = 0;
672 for (i = 0; i < ngroups; i++) {
673 gdp = ext4_get_group_desc(sb, i, NULL);
674 if (!gdp)
675 continue;
676 desc_count += ext4_free_group_clusters(sb, gdp);
677 }
678
679 return desc_count;
680#endif
681}
682
683static inline int test_root(ext4_group_t a, int b)
684{
685 while (1) {
686 if (a < b)
687 return 0;
688 if (a == b)
689 return 1;
690 if ((a % b) != 0)
691 return 0;
692 a = a / b;
693 }
694}
695
696static int ext4_group_sparse(ext4_group_t group)
697{
698 if (group <= 1)
699 return 1;
700 if (!(group & 1))
701 return 0;
702 return (test_root(group, 7) || test_root(group, 5) ||
703 test_root(group, 3));
704}
705
706
707
708
709
710
711
712
713
714int ext4_bg_has_super(struct super_block *sb, ext4_group_t group)
715{
716 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
717 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER) &&
718 !ext4_group_sparse(group))
719 return 0;
720 return 1;
721}
722
723static unsigned long ext4_bg_num_gdb_meta(struct super_block *sb,
724 ext4_group_t group)
725{
726 unsigned long metagroup = group / EXT4_DESC_PER_BLOCK(sb);
727 ext4_group_t first = metagroup * EXT4_DESC_PER_BLOCK(sb);
728 ext4_group_t last = first + EXT4_DESC_PER_BLOCK(sb) - 1;
729
730 if (group == first || group == first + 1 || group == last)
731 return 1;
732 return 0;
733}
734
735static unsigned long ext4_bg_num_gdb_nometa(struct super_block *sb,
736 ext4_group_t group)
737{
738 if (!ext4_bg_has_super(sb, group))
739 return 0;
740
741 if (EXT4_HAS_INCOMPAT_FEATURE(sb,EXT4_FEATURE_INCOMPAT_META_BG))
742 return le32_to_cpu(EXT4_SB(sb)->s_es->s_first_meta_bg);
743 else
744 return EXT4_SB(sb)->s_gdb_count;
745}
746
747
748
749
750
751
752
753
754
755
756unsigned long ext4_bg_num_gdb(struct super_block *sb, ext4_group_t group)
757{
758 unsigned long first_meta_bg =
759 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_meta_bg);
760 unsigned long metagroup = group / EXT4_DESC_PER_BLOCK(sb);
761
762 if (!EXT4_HAS_INCOMPAT_FEATURE(sb,EXT4_FEATURE_INCOMPAT_META_BG) ||
763 metagroup < first_meta_bg)
764 return ext4_bg_num_gdb_nometa(sb, group);
765
766 return ext4_bg_num_gdb_meta(sb,group);
767
768}
769
770
771
772
773
774static unsigned ext4_num_base_meta_clusters(struct super_block *sb,
775 ext4_group_t block_group)
776{
777 struct ext4_sb_info *sbi = EXT4_SB(sb);
778 unsigned num;
779
780
781 num = ext4_bg_has_super(sb, block_group);
782
783 if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
784 block_group < le32_to_cpu(sbi->s_es->s_first_meta_bg) *
785 sbi->s_desc_per_block) {
786 if (num) {
787 num += ext4_bg_num_gdb(sb, block_group);
788 num += le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks);
789 }
790 } else {
791 num += ext4_bg_num_gdb(sb, block_group);
792 }
793 return EXT4_NUM_B2C(sbi, num);
794}
795
796
797
798
799
800
801
802ext4_fsblk_t ext4_inode_to_goal_block(struct inode *inode)
803{
804 struct ext4_inode_info *ei = EXT4_I(inode);
805 ext4_group_t block_group;
806 ext4_grpblk_t colour;
807 int flex_size = ext4_flex_bg_size(EXT4_SB(inode->i_sb));
808 ext4_fsblk_t bg_start;
809 ext4_fsblk_t last_block;
810
811 block_group = ei->i_block_group;
812 if (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) {
813
814
815
816
817
818
819
820
821 block_group &= ~(flex_size-1);
822 if (S_ISREG(inode->i_mode))
823 block_group++;
824 }
825 bg_start = ext4_group_first_block_no(inode->i_sb, block_group);
826 last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1;
827
828
829
830
831
832 if (test_opt(inode->i_sb, DELALLOC))
833 return bg_start;
834
835 if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block)
836 colour = (current->pid % 16) *
837 (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16);
838 else
839 colour = (current->pid % 16) * ((last_block - bg_start) / 16);
840 return bg_start + colour;
841}
842
843