summaryrefslogtreecommitdiff
path: root/fs/bcachefs/disk_accounting.c
blob: 9f3133e3e7e5e4deca5c45cc090f4792a5e2671e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
// SPDX-License-Identifier: GPL-2.0

#include "bcachefs.h"
#include "bcachefs_ioctl.h"
#include "btree_cache.h"
#include "btree_journal_iter.h"
#include "btree_update.h"
#include "btree_write_buffer.h"
#include "buckets.h"
#include "compress.h"
#include "disk_accounting.h"
#include "error.h"
#include "journal_io.h"
#include "replicas.h"

/*
 * Notes on disk accounting:
 *
 * We have two parallel sets of counters to be concerned with, and both must be
 * kept in sync.
 *
 *  - Persistent/on disk accounting, stored in the accounting btree and updated
 *    via btree write buffer updates that treat new accounting keys as deltas to
 *    apply to existing values. But reading from a write buffer btree is
 *    expensive, so we also have
 *
 *  - In memory accounting, where accounting is stored as an array of percpu
 *    counters, indexed by an eytzinger array of disk acounting keys/bpos (which
 *    are the same thing, excepting byte swabbing on big endian).
 *
 *    Cheap to read, but non persistent.
 *
 * Disk accounting updates are generated by transactional triggers; these run as
 * keys enter and leave the btree, and can compare old and new versions of keys;
 * the output of these triggers are deltas to the various counters.
 *
 * Disk accounting updates are done as btree write buffer updates, where the
 * counters in the disk accounting key are deltas that will be applied to the
 * counter in the btree when the key is flushed by the write buffer (or journal
 * replay).
 *
 * To do a disk accounting update:
 * - initialize a disk_accounting_pos, to specify which counter is being update
 * - initialize counter deltas, as an array of 1-3 s64s
 * - call bch2_disk_accounting_mod()
 *
 * This queues up the accounting update to be done at transaction commit time.
 * Underneath, it's a normal btree write buffer update.
 *
 * The transaction commit path is responsible for propagating updates to the in
 * memory counters, with bch2_accounting_mem_mod().
 *
 * The commit path also assigns every disk accounting update a unique version
 * number, based on the journal sequence number and offset within that journal
 * buffer; this is used by journal replay to determine which updates have been
 * done.
 *
 * The transaction commit path also ensures that replicas entry accounting
 * updates are properly marked in the superblock (so that we know whether we can
 * mount without data being unavailable); it will update the superblock if
 * bch2_accounting_mem_mod() tells it to.
 */

static const char * const disk_accounting_type_strs[] = {
#define x(t, n, ...) [n] = #t,
	BCH_DISK_ACCOUNTING_TYPES()
#undef x
	NULL
};

static inline void accounting_key_init(struct bkey_i *k, struct disk_accounting_pos *pos,
				       s64 *d, unsigned nr)
{
	struct bkey_i_accounting *acc = bkey_accounting_init(k);

	acc->k.p = disk_accounting_pos_to_bpos(pos);
	set_bkey_val_u64s(&acc->k, sizeof(struct bch_accounting) / sizeof(u64) + nr);

	memcpy_u64s_small(acc->v.d, d, nr);
}

int bch2_disk_accounting_mod(struct btree_trans *trans,
			     struct disk_accounting_pos *k,
			     s64 *d, unsigned nr, bool gc)
{
	/* Normalize: */
	switch (k->type) {
	case BCH_DISK_ACCOUNTING_replicas:
		bubble_sort(k->replicas.devs, k->replicas.nr_devs, u8_cmp);
		break;
	}

	BUG_ON(nr > BCH_ACCOUNTING_MAX_COUNTERS);

	struct { __BKEY_PADDED(k, BCH_ACCOUNTING_MAX_COUNTERS); } k_i;

	accounting_key_init(&k_i.k, k, d, nr);

	return likely(!gc)
		? bch2_trans_update_buffered(trans, BTREE_ID_accounting, &k_i.k)
		: bch2_accounting_mem_add(trans, bkey_i_to_s_c_accounting(&k_i.k), true);
}

int bch2_mod_dev_cached_sectors(struct btree_trans *trans,
				unsigned dev, s64 sectors,
				bool gc)
{
	struct disk_accounting_pos acc = {
		.type = BCH_DISK_ACCOUNTING_replicas,
	};

	bch2_replicas_entry_cached(&acc.replicas, dev);

	return bch2_disk_accounting_mod(trans, &acc, &sectors, 1, gc);
}

static inline bool is_zero(char *start, char *end)
{
	BUG_ON(start > end);

	for (; start < end; start++)
		if (*start)
			return false;
	return true;
}

#define field_end(p, member)	(((void *) (&p.member)) + sizeof(p.member))

int bch2_accounting_validate(struct bch_fs *c, struct bkey_s_c k,
			     enum bch_validate_flags flags)
{
	struct disk_accounting_pos acc_k;
	bpos_to_disk_accounting_pos(&acc_k, k.k->p);
	void *end = &acc_k + 1;
	int ret = 0;

	bkey_fsck_err_on(bversion_zero(k.k->bversion),
			 c, accounting_key_version_0,
			 "accounting key with version=0");

	switch (acc_k.type) {
	case BCH_DISK_ACCOUNTING_nr_inodes:
		end = field_end(acc_k, nr_inodes);
		break;
	case BCH_DISK_ACCOUNTING_persistent_reserved:
		end = field_end(acc_k, persistent_reserved);
		break;
	case BCH_DISK_ACCOUNTING_replicas:
		bkey_fsck_err_on(!acc_k.replicas.nr_devs,
				 c, accounting_key_replicas_nr_devs_0,
				 "accounting key replicas entry with nr_devs=0");

		bkey_fsck_err_on(acc_k.replicas.nr_required > acc_k.replicas.nr_devs ||
				 (acc_k.replicas.nr_required > 1 &&
				  acc_k.replicas.nr_required == acc_k.replicas.nr_devs),
				 c, accounting_key_replicas_nr_required_bad,
				 "accounting key replicas entry with bad nr_required");

		for (unsigned i = 0; i + 1 < acc_k.replicas.nr_devs; i++)
			bkey_fsck_err_on(acc_k.replicas.devs[i] >= acc_k.replicas.devs[i + 1],
					 c, accounting_key_replicas_devs_unsorted,
					 "accounting key replicas entry with unsorted devs");

		end = (void *) &acc_k.replicas + replicas_entry_bytes(&acc_k.replicas);
		break;
	case BCH_DISK_ACCOUNTING_dev_data_type:
		end = field_end(acc_k, dev_data_type);
		break;
	case BCH_DISK_ACCOUNTING_compression:
		end = field_end(acc_k, compression);
		break;
	case BCH_DISK_ACCOUNTING_snapshot:
		end = field_end(acc_k, snapshot);
		break;
	case BCH_DISK_ACCOUNTING_btree:
		end = field_end(acc_k, btree);
		break;
	case BCH_DISK_ACCOUNTING_rebalance_work:
		end = field_end(acc_k, rebalance_work);
		break;
	}

	bkey_fsck_err_on(!is_zero(end, (void *) (&acc_k + 1)),
			 c, accounting_key_junk_at_end,
			 "junk at end of accounting key");
fsck_err:
	return ret;
}

void bch2_accounting_key_to_text(struct printbuf *out, struct disk_accounting_pos *k)
{
	if (k->type >= BCH_DISK_ACCOUNTING_TYPE_NR) {
		prt_printf(out, "unknown type %u", k->type);
		return;
	}

	prt_str(out, disk_accounting_type_strs[k->type]);
	prt_str(out, " ");

	switch (k->type) {
	case BCH_DISK_ACCOUNTING_nr_inodes:
		break;
	case BCH_DISK_ACCOUNTING_persistent_reserved:
		prt_printf(out, "replicas=%u", k->persistent_reserved.nr_replicas);
		break;
	case BCH_DISK_ACCOUNTING_replicas:
		bch2_replicas_entry_to_text(out, &k->replicas);
		break;
	case BCH_DISK_ACCOUNTING_dev_data_type:
		prt_printf(out, "dev=%u data_type=", k->dev_data_type.dev);
		bch2_prt_data_type(out, k->dev_data_type.data_type);
		break;
	case BCH_DISK_ACCOUNTING_compression:
		bch2_prt_compression_type(out, k->compression.type);
		break;
	case BCH_DISK_ACCOUNTING_snapshot:
		prt_printf(out, "id=%u", k->snapshot.id);
		break;
	case BCH_DISK_ACCOUNTING_btree:
		prt_printf(out, "btree=%s", bch2_btree_id_str(k->btree.id));
		break;
	}
}

void bch2_accounting_to_text(struct printbuf *out, struct bch_fs *c, struct bkey_s_c k)
{
	struct bkey_s_c_accounting acc = bkey_s_c_to_accounting(k);
	struct disk_accounting_pos acc_k;
	bpos_to_disk_accounting_pos(&acc_k, k.k->p);

	bch2_accounting_key_to_text(out, &acc_k);

	for (unsigned i = 0; i < bch2_accounting_counters(k.k); i++)
		prt_printf(out, " %lli", acc.v->d[i]);
}

void bch2_accounting_swab(struct bkey_s k)
{
	for (u64 *p = (u64 *) k.v;
	     p < (u64 *) bkey_val_end(k);
	     p++)
		*p = swab64(*p);
}

static inline bool accounting_to_replicas(struct bch_replicas_entry_v1 *r, struct bpos p)
{
	struct disk_accounting_pos acc_k;
	bpos_to_disk_accounting_pos(&acc_k, p);

	switch (acc_k.type) {
	case BCH_DISK_ACCOUNTING_replicas:
		unsafe_memcpy(r, &acc_k.replicas,
			      replicas_entry_bytes(&acc_k.replicas),
			      "variable length struct");
		return true;
	default:
		return false;
	}
}

static int bch2_accounting_update_sb_one(struct bch_fs *c, struct bpos p)
{
	struct bch_replicas_padded r;
	return accounting_to_replicas(&r.e, p)
		? bch2_mark_replicas(c, &r.e)
		: 0;
}

/*
 * Ensure accounting keys being updated are present in the superblock, when
 * applicable (i.e. replicas updates)
 */
int bch2_accounting_update_sb(struct btree_trans *trans)
{
	for (struct jset_entry *i = trans->journal_entries;
	     i != (void *) ((u64 *) trans->journal_entries + trans->journal_entries_u64s);
	     i = vstruct_next(i))
		if (jset_entry_is_key(i) && i->start->k.type == KEY_TYPE_accounting) {
			int ret = bch2_accounting_update_sb_one(trans->c, i->start->k.p);
			if (ret)
				return ret;
		}

	return 0;
}

static int __bch2_accounting_mem_insert(struct bch_fs *c, struct bkey_s_c_accounting a)
{
	struct bch_accounting_mem *acc = &c->accounting;

	/* raced with another insert, already present: */
	if (eytzinger0_find(acc->k.data, acc->k.nr, sizeof(acc->k.data[0]),
			    accounting_pos_cmp, &a.k->p) < acc->k.nr)
		return 0;

	struct accounting_mem_entry n = {
		.pos		= a.k->p,
		.bversion	= a.k->bversion,
		.nr_counters	= bch2_accounting_counters(a.k),
		.v[0]		= __alloc_percpu_gfp(n.nr_counters * sizeof(u64),
						     sizeof(u64), GFP_KERNEL),
	};

	if (!n.v[0])
		goto err;

	if (acc->gc_running) {
		n.v[1] = __alloc_percpu_gfp(n.nr_counters * sizeof(u64),
					    sizeof(u64), GFP_KERNEL);
		if (!n.v[1])
			goto err;
	}

	if (darray_push(&acc->k, n))
		goto err;

	eytzinger0_sort(acc->k.data, acc->k.nr, sizeof(acc->k.data[0]),
			accounting_pos_cmp, NULL);
	return 0;
err:
	free_percpu(n.v[1]);
	free_percpu(n.v[0]);
	return -BCH_ERR_ENOMEM_disk_accounting;
}

int bch2_accounting_mem_insert(struct bch_fs *c, struct bkey_s_c_accounting a,
			       enum bch_accounting_mode mode)
{
	struct bch_replicas_padded r;

	if (mode != BCH_ACCOUNTING_read &&
	    accounting_to_replicas(&r.e, a.k->p) &&
	    !bch2_replicas_marked_locked(c, &r.e))
		return -BCH_ERR_btree_insert_need_mark_replicas;

	percpu_up_read(&c->mark_lock);
	percpu_down_write(&c->mark_lock);
	int ret = __bch2_accounting_mem_insert(c, a);
	percpu_up_write(&c->mark_lock);
	percpu_down_read(&c->mark_lock);
	return ret;
}

static bool accounting_mem_entry_is_zero(struct accounting_mem_entry *e)
{
	for (unsigned i = 0; i < e->nr_counters; i++)
		if (percpu_u64_get(e->v[0] + i) ||
		    (e->v[1] &&
		     percpu_u64_get(e->v[1] + i)))
			return false;
	return true;
}

void bch2_accounting_mem_gc(struct bch_fs *c)
{
	struct bch_accounting_mem *acc = &c->accounting;

	percpu_down_write(&c->mark_lock);
	struct accounting_mem_entry *dst = acc->k.data;

	darray_for_each(acc->k, src) {
		if (accounting_mem_entry_is_zero(src)) {
			free_percpu(src->v[0]);
			free_percpu(src->v[1]);
		} else {
			*dst++ = *src;
		}
	}

	acc->k.nr = dst - acc->k.data;
	eytzinger0_sort(acc->k.data, acc->k.nr, sizeof(acc->k.data[0]),
			accounting_pos_cmp, NULL);
	percpu_up_write(&c->mark_lock);
}

/*
 * Read out accounting keys for replicas entries, as an array of
 * bch_replicas_usage entries.
 *
 * Note: this may be deprecated/removed at smoe point in the future and replaced
 * with something more general, it exists to support the ioctl used by the
 * 'bcachefs fs usage' command.
 */
int bch2_fs_replicas_usage_read(struct bch_fs *c, darray_char *usage)
{
	struct bch_accounting_mem *acc = &c->accounting;
	int ret = 0;

	darray_init(usage);

	percpu_down_read(&c->mark_lock);
	darray_for_each(acc->k, i) {
		struct {
			struct bch_replicas_usage r;
			u8 pad[BCH_BKEY_PTRS_MAX];
		} u;

		if (!accounting_to_replicas(&u.r.r, i->pos))
			continue;

		u64 sectors;
		bch2_accounting_mem_read_counters(acc, i - acc->k.data, &sectors, 1, false);
		u.r.sectors = sectors;

		ret = darray_make_room(usage, replicas_usage_bytes(&u.r));
		if (ret)
			break;

		memcpy(&darray_top(*usage), &u.r, replicas_usage_bytes(&u.r));
		usage->nr += replicas_usage_bytes(&u.r);
	}
	percpu_up_read(&c->mark_lock);

	if (ret)
		darray_exit(usage);
	return ret;
}

int bch2_fs_accounting_read(struct bch_fs *c, darray_char *out_buf, unsigned accounting_types_mask)
{

	struct bch_accounting_mem *acc = &c->accounting;
	int ret = 0;

	darray_init(out_buf);

	percpu_down_read(&c->mark_lock);
	darray_for_each(acc->k, i) {
		struct disk_accounting_pos a_p;
		bpos_to_disk_accounting_pos(&a_p, i->pos);

		if (!(accounting_types_mask & BIT(a_p.type)))
			continue;

		ret = darray_make_room(out_buf, sizeof(struct bkey_i_accounting) +
				       sizeof(u64) * i->nr_counters);
		if (ret)
			break;

		struct bkey_i_accounting *a_out =
			bkey_accounting_init((void *) &darray_top(*out_buf));
		set_bkey_val_u64s(&a_out->k, i->nr_counters);
		a_out->k.p = i->pos;
		bch2_accounting_mem_read_counters(acc, i - acc->k.data,
						  a_out->v.d, i->nr_counters, false);

		if (!bch2_accounting_key_is_zero(accounting_i_to_s_c(a_out)))
			out_buf->nr += bkey_bytes(&a_out->k);
	}

	percpu_up_read(&c->mark_lock);

	if (ret)
		darray_exit(out_buf);
	return ret;
}

void bch2_fs_accounting_to_text(struct printbuf *out, struct bch_fs *c)
{
	struct bch_accounting_mem *acc = &c->accounting;

	percpu_down_read(&c->mark_lock);
	out->atomic++;

	eytzinger0_for_each(i, acc->k.nr) {
		struct disk_accounting_pos acc_k;
		bpos_to_disk_accounting_pos(&acc_k, acc->k.data[i].pos);

		bch2_accounting_key_to_text(out, &acc_k);

		u64 v[BCH_ACCOUNTING_MAX_COUNTERS];
		bch2_accounting_mem_read_counters(acc, i, v, ARRAY_SIZE(v), false);

		prt_str(out, ":");
		for (unsigned j = 0; j < acc->k.data[i].nr_counters; j++)
			prt_printf(out, " %llu", v[j]);
		prt_newline(out);
	}

	--out->atomic;
	percpu_up_read(&c->mark_lock);
}

static void bch2_accounting_free_counters(struct bch_accounting_mem *acc, bool gc)
{
	darray_for_each(acc->k, e) {
		free_percpu(e->v[gc]);
		e->v[gc] = NULL;
	}
}

int bch2_gc_accounting_start(struct bch_fs *c)
{
	struct bch_accounting_mem *acc = &c->accounting;
	int ret = 0;

	percpu_down_write(&c->mark_lock);
	darray_for_each(acc->k, e) {
		e->v[1] = __alloc_percpu_gfp(e->nr_counters * sizeof(u64),
					     sizeof(u64), GFP_KERNEL);
		if (!e->v[1]) {
			bch2_accounting_free_counters(acc, true);
			ret = -BCH_ERR_ENOMEM_disk_accounting;
			break;
		}
	}

	acc->gc_running = !ret;
	percpu_up_write(&c->mark_lock);

	return ret;
}

int bch2_gc_accounting_done(struct bch_fs *c)
{
	struct bch_accounting_mem *acc = &c->accounting;
	struct btree_trans *trans = bch2_trans_get(c);
	struct printbuf buf = PRINTBUF;
	struct bpos pos = POS_MIN;
	int ret = 0;

	percpu_down_write(&c->mark_lock);
	while (1) {
		unsigned idx = eytzinger0_find_ge(acc->k.data, acc->k.nr, sizeof(acc->k.data[0]),
						  accounting_pos_cmp, &pos);

		if (idx >= acc->k.nr)
			break;

		struct accounting_mem_entry *e = acc->k.data + idx;
		pos = bpos_successor(e->pos);

		struct disk_accounting_pos acc_k;
		bpos_to_disk_accounting_pos(&acc_k, e->pos);

		if (acc_k.type >= BCH_DISK_ACCOUNTING_TYPE_NR)
			continue;

		u64 src_v[BCH_ACCOUNTING_MAX_COUNTERS];
		u64 dst_v[BCH_ACCOUNTING_MAX_COUNTERS];

		unsigned nr = e->nr_counters;
		bch2_accounting_mem_read_counters(acc, idx, dst_v, nr, false);
		bch2_accounting_mem_read_counters(acc, idx, src_v, nr, true);

		if (memcmp(dst_v, src_v, nr * sizeof(u64))) {
			printbuf_reset(&buf);
			prt_str(&buf, "accounting mismatch for ");
			bch2_accounting_key_to_text(&buf, &acc_k);

			prt_str(&buf, ": got");
			for (unsigned j = 0; j < nr; j++)
				prt_printf(&buf, " %llu", dst_v[j]);

			prt_str(&buf, " should be");
			for (unsigned j = 0; j < nr; j++)
				prt_printf(&buf, " %llu", src_v[j]);

			for (unsigned j = 0; j < nr; j++)
				src_v[j] -= dst_v[j];

			if (fsck_err(trans, accounting_mismatch, "%s", buf.buf)) {
				percpu_up_write(&c->mark_lock);
				ret = commit_do(trans, NULL, NULL, 0,
						bch2_disk_accounting_mod(trans, &acc_k, src_v, nr, false));
				percpu_down_write(&c->mark_lock);
				if (ret)
					goto err;

				if (!test_bit(BCH_FS_may_go_rw, &c->flags)) {
					memset(&trans->fs_usage_delta, 0, sizeof(trans->fs_usage_delta));
					struct { __BKEY_PADDED(k, BCH_ACCOUNTING_MAX_COUNTERS); } k_i;

					accounting_key_init(&k_i.k, &acc_k, src_v, nr);
					bch2_accounting_mem_mod_locked(trans,
								bkey_i_to_s_c_accounting(&k_i.k),
								BCH_ACCOUNTING_normal);

					preempt_disable();
					struct bch_fs_usage_base *dst = this_cpu_ptr(c->usage);
					struct bch_fs_usage_base *src = &trans->fs_usage_delta;
					acc_u64s((u64 *) dst, (u64 *) src, sizeof(*src) / sizeof(u64));
					preempt_enable();
				}
			}
		}
	}
err:
fsck_err:
	percpu_up_write(&c->mark_lock);
	printbuf_exit(&buf);
	bch2_trans_put(trans);
	bch_err_fn(c, ret);
	return ret;
}

static int accounting_read_key(struct btree_trans *trans, struct bkey_s_c k)
{
	struct bch_fs *c = trans->c;

	if (k.k->type != KEY_TYPE_accounting)
		return 0;

	percpu_down_read(&c->mark_lock);
	int ret = bch2_accounting_mem_mod_locked(trans, bkey_s_c_to_accounting(k),
						 BCH_ACCOUNTING_read);
	percpu_up_read(&c->mark_lock);
	return ret;
}

/*
 * At startup time, initialize the in memory accounting from the btree (and
 * journal)
 */
int bch2_accounting_read(struct bch_fs *c)
{
	struct bch_accounting_mem *acc = &c->accounting;
	struct btree_trans *trans = bch2_trans_get(c);
	struct printbuf buf = PRINTBUF;

	int ret = for_each_btree_key(trans, iter,
				BTREE_ID_accounting, POS_MIN,
				BTREE_ITER_prefetch|BTREE_ITER_all_snapshots, k, ({
			struct bkey u;
			struct bkey_s_c k = bch2_btree_path_peek_slot_exact(btree_iter_path(trans, &iter), &u);
			accounting_read_key(trans, k);
		}));
	if (ret)
		goto err;

	struct journal_keys *keys = &c->journal_keys;
	struct journal_key *dst = keys->data;
	move_gap(keys, keys->nr);

	darray_for_each(*keys, i) {
		if (i->k->k.type == KEY_TYPE_accounting) {
			struct bkey_s_c k = bkey_i_to_s_c(i->k);
			unsigned idx = eytzinger0_find(acc->k.data, acc->k.nr,
						sizeof(acc->k.data[0]),
						accounting_pos_cmp, &k.k->p);

			bool applied = idx < acc->k.nr &&
				bversion_cmp(acc->k.data[idx].bversion, k.k->bversion) >= 0;

			if (applied)
				continue;

			if (i + 1 < &darray_top(*keys) &&
			    i[1].k->k.type == KEY_TYPE_accounting &&
			    !journal_key_cmp(i, i + 1)) {
				WARN_ON(bversion_cmp(i[0].k->k.bversion, i[1].k->k.bversion) >= 0);

				i[1].journal_seq = i[0].journal_seq;

				bch2_accounting_accumulate(bkey_i_to_accounting(i[1].k),
							   bkey_s_c_to_accounting(k));
				continue;
			}

			ret = accounting_read_key(trans, k);
			if (ret)
				goto err;
		}

		*dst++ = *i;
	}
	keys->gap = keys->nr = dst - keys->data;

	percpu_down_read(&c->mark_lock);
	for (unsigned i = 0; i < acc->k.nr; i++) {
		u64 v[BCH_ACCOUNTING_MAX_COUNTERS];
		bch2_accounting_mem_read_counters(acc, i, v, ARRAY_SIZE(v), false);

		if (bch2_is_zero(v, sizeof(v[0]) * acc->k.data[i].nr_counters))
			continue;

		struct bch_replicas_padded r;
		if (!accounting_to_replicas(&r.e, acc->k.data[i].pos))
			continue;

		/*
		 * If the replicas entry is invalid it'll get cleaned up by
		 * check_allocations:
		 */
		if (bch2_replicas_entry_validate(&r.e, c, &buf))
			continue;

		struct disk_accounting_pos k;
		bpos_to_disk_accounting_pos(&k, acc->k.data[i].pos);

		if (fsck_err_on(!bch2_replicas_marked_locked(c, &r.e),
				trans, accounting_replicas_not_marked,
				"accounting not marked in superblock replicas\n  %s",
				(printbuf_reset(&buf),
				 bch2_accounting_key_to_text(&buf, &k),
				 buf.buf))) {
			/*
			 * We're not RW yet and still single threaded, dropping
			 * and retaking lock is ok:
			 */
			percpu_up_read(&c->mark_lock);
			ret = bch2_mark_replicas(c, &r.e);
			if (ret)
				goto fsck_err;
			percpu_down_read(&c->mark_lock);
		}
	}

	preempt_disable();
	struct bch_fs_usage_base *usage = this_cpu_ptr(c->usage);

	for (unsigned i = 0; i < acc->k.nr; i++) {
		struct disk_accounting_pos k;
		bpos_to_disk_accounting_pos(&k, acc->k.data[i].pos);

		u64 v[BCH_ACCOUNTING_MAX_COUNTERS];
		bch2_accounting_mem_read_counters(acc, i, v, ARRAY_SIZE(v), false);

		switch (k.type) {
		case BCH_DISK_ACCOUNTING_persistent_reserved:
			usage->reserved += v[0] * k.persistent_reserved.nr_replicas;
			break;
		case BCH_DISK_ACCOUNTING_replicas:
			fs_usage_data_type_to_base(usage, k.replicas.data_type, v[0]);
			break;
		case BCH_DISK_ACCOUNTING_dev_data_type:
			rcu_read_lock();
			struct bch_dev *ca = bch2_dev_rcu(c, k.dev_data_type.dev);
			if (ca) {
				struct bch_dev_usage_type __percpu *d = &ca->usage->d[k.dev_data_type.data_type];
				percpu_u64_set(&d->buckets,	v[0]);
				percpu_u64_set(&d->sectors,	v[1]);
				percpu_u64_set(&d->fragmented,	v[2]);

				if (k.dev_data_type.data_type == BCH_DATA_sb ||
				    k.dev_data_type.data_type == BCH_DATA_journal)
					usage->hidden += v[0] * ca->mi.bucket_size;
			}
			rcu_read_unlock();
			break;
		}
	}
	preempt_enable();
fsck_err:
	percpu_up_read(&c->mark_lock);
err:
	printbuf_exit(&buf);
	bch2_trans_put(trans);
	bch_err_fn(c, ret);
	return ret;
}

int bch2_dev_usage_remove(struct bch_fs *c, unsigned dev)
{
	return bch2_trans_run(c,
		bch2_btree_write_buffer_flush_sync(trans) ?:
		for_each_btree_key_commit(trans, iter, BTREE_ID_accounting, POS_MIN,
				BTREE_ITER_all_snapshots, k, NULL, NULL, 0, ({
			struct disk_accounting_pos acc;
			bpos_to_disk_accounting_pos(&acc, k.k->p);

			acc.type == BCH_DISK_ACCOUNTING_dev_data_type &&
			acc.dev_data_type.dev == dev
				? bch2_btree_bit_mod_buffered(trans, BTREE_ID_accounting, k.k->p, 0)
				: 0;
		})) ?:
		bch2_btree_write_buffer_flush_sync(trans));
}

int bch2_dev_usage_init(struct bch_dev *ca, bool gc)
{
	struct bch_fs *c = ca->fs;
	struct disk_accounting_pos acc = {
		.type = BCH_DISK_ACCOUNTING_dev_data_type,
		.dev_data_type.dev = ca->dev_idx,
		.dev_data_type.data_type = BCH_DATA_free,
	};
	u64 v[3] = { ca->mi.nbuckets - ca->mi.first_bucket, 0, 0 };

	int ret = bch2_trans_do(c, NULL, NULL, 0,
			bch2_disk_accounting_mod(trans, &acc, v, ARRAY_SIZE(v), gc));
	bch_err_fn(c, ret);
	return ret;
}

void bch2_verify_accounting_clean(struct bch_fs *c)
{
	bool mismatch = false;
	struct bch_fs_usage_base base = {}, base_inmem = {};

	bch2_trans_run(c,
		for_each_btree_key(trans, iter,
				   BTREE_ID_accounting, POS_MIN,
				   BTREE_ITER_all_snapshots, k, ({
			u64 v[BCH_ACCOUNTING_MAX_COUNTERS];
			struct bkey_s_c_accounting a = bkey_s_c_to_accounting(k);
			unsigned nr = bch2_accounting_counters(k.k);

			struct disk_accounting_pos acc_k;
			bpos_to_disk_accounting_pos(&acc_k, k.k->p);

			if (acc_k.type >= BCH_DISK_ACCOUNTING_TYPE_NR)
				continue;

			if (acc_k.type == BCH_DISK_ACCOUNTING_inum)
				continue;

			bch2_accounting_mem_read(c, k.k->p, v, nr);

			if (memcmp(a.v->d, v, nr * sizeof(u64))) {
				struct printbuf buf = PRINTBUF;

				bch2_bkey_val_to_text(&buf, c, k);
				prt_str(&buf, " !=");
				for (unsigned j = 0; j < nr; j++)
					prt_printf(&buf, " %llu", v[j]);

				pr_err("%s", buf.buf);
				printbuf_exit(&buf);
				mismatch = true;
			}

			switch (acc_k.type) {
			case BCH_DISK_ACCOUNTING_persistent_reserved:
				base.reserved += acc_k.persistent_reserved.nr_replicas * a.v->d[0];
				break;
			case BCH_DISK_ACCOUNTING_replicas:
				fs_usage_data_type_to_base(&base, acc_k.replicas.data_type, a.v->d[0]);
				break;
			case BCH_DISK_ACCOUNTING_dev_data_type: {
				rcu_read_lock();
				struct bch_dev *ca = bch2_dev_rcu(c, acc_k.dev_data_type.dev);
				if (!ca) {
					rcu_read_unlock();
					continue;
				}

				v[0] = percpu_u64_get(&ca->usage->d[acc_k.dev_data_type.data_type].buckets);
				v[1] = percpu_u64_get(&ca->usage->d[acc_k.dev_data_type.data_type].sectors);
				v[2] = percpu_u64_get(&ca->usage->d[acc_k.dev_data_type.data_type].fragmented);
				rcu_read_unlock();

				if (memcmp(a.v->d, v, 3 * sizeof(u64))) {
					struct printbuf buf = PRINTBUF;

					bch2_bkey_val_to_text(&buf, c, k);
					prt_str(&buf, " in mem");
					for (unsigned j = 0; j < nr; j++)
						prt_printf(&buf, " %llu", v[j]);

					pr_err("dev accounting mismatch: %s", buf.buf);
					printbuf_exit(&buf);
					mismatch = true;
				}
			}
			}

			0;
		})));

	acc_u64s_percpu(&base_inmem.hidden, &c->usage->hidden, sizeof(base_inmem) / sizeof(u64));

#define check(x)										\
	if (base.x != base_inmem.x) {								\
		pr_err("fs_usage_base.%s mismatch: %llu != %llu", #x, base.x, base_inmem.x);	\
		mismatch = true;								\
	}

	//check(hidden);
	check(btree);
	check(data);
	check(cached);
	check(reserved);
	check(nr_inodes);

	WARN_ON(mismatch);
}

void bch2_accounting_gc_free(struct bch_fs *c)
{
	lockdep_assert_held(&c->mark_lock);

	struct bch_accounting_mem *acc = &c->accounting;

	bch2_accounting_free_counters(acc, true);
	acc->gc_running = false;
}

void bch2_fs_accounting_exit(struct bch_fs *c)
{
	struct bch_accounting_mem *acc = &c->accounting;

	bch2_accounting_free_counters(acc, false);
	darray_exit(&acc->k);
}