summaryrefslogtreecommitdiff
path: root/fs/bcachefs/btree_iter.h
blob: 798eb1c47966d29d9aeb0c3a1f888a914745978e (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
896
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _BCACHEFS_BTREE_ITER_H
#define _BCACHEFS_BTREE_ITER_H

#include "bset.h"
#include "btree_types.h"
#include "trace.h"

static inline int __bkey_err(const struct bkey *k)
{
	return PTR_ERR_OR_ZERO(k);
}

#define bkey_err(_k)	__bkey_err((_k).k)

static inline void __btree_path_get(struct btree_path *path, bool intent)
{
	path->ref++;
	path->intent_ref += intent;
}

static inline bool __btree_path_put(struct btree_path *path, bool intent)
{
	EBUG_ON(!path->ref);
	EBUG_ON(!path->intent_ref && intent);
	path->intent_ref -= intent;
	return --path->ref == 0;
}

static inline void btree_path_set_dirty(struct btree_path *path,
					enum btree_path_uptodate u)
{
	path->uptodate = max_t(unsigned, path->uptodate, u);
}

static inline struct btree *btree_path_node(struct btree_path *path,
					    unsigned level)
{
	return level < BTREE_MAX_DEPTH ? path->l[level].b : NULL;
}

static inline bool btree_node_lock_seq_matches(const struct btree_path *path,
					const struct btree *b, unsigned level)
{
	return path->l[level].lock_seq == six_lock_seq(&b->c.lock);
}

static inline struct btree *btree_node_parent(struct btree_path *path,
					      struct btree *b)
{
	return btree_path_node(path, b->c.level + 1);
}

/* Iterate over paths within a transaction: */

void __bch2_btree_trans_sort_paths(struct btree_trans *);

static inline void btree_trans_sort_paths(struct btree_trans *trans)
{
	if (!IS_ENABLED(CONFIG_BCACHEFS_DEBUG) &&
	    trans->paths_sorted)
		return;
	__bch2_btree_trans_sort_paths(trans);
}

static inline unsigned long *trans_paths_nr(struct btree_path *paths)
{
	return &container_of(paths, struct btree_trans_paths, paths[0])->nr_paths;
}

static inline unsigned long *trans_paths_allocated(struct btree_path *paths)
{
	unsigned long *v = trans_paths_nr(paths);
	return v - BITS_TO_LONGS(*v);
}

#define trans_for_each_path_idx_from(_paths_allocated, _nr, _idx, _start)\
	for (_idx = _start;						\
	     (_idx = find_next_bit(_paths_allocated, _nr, _idx)) < _nr;	\
	     _idx++)

static inline struct btree_path *
__trans_next_path(struct btree_trans *trans, unsigned *idx)
{
	unsigned long *w = trans->paths_allocated + *idx / BITS_PER_LONG;
	/*
	 * Open coded find_next_bit(), because
	 *  - this is fast path, we can't afford the function call
	 *  - and we know that nr_paths is a multiple of BITS_PER_LONG,
	 */
	while (*idx < trans->nr_paths) {
		unsigned long v = *w >> (*idx & (BITS_PER_LONG - 1));
		if (v) {
			*idx += __ffs(v);
			return trans->paths + *idx;
		}

		*idx += BITS_PER_LONG;
		*idx &= ~(BITS_PER_LONG - 1);
		w++;
	}

	return NULL;
}

/*
 * This version is intended to be safe for use on a btree_trans that is owned by
 * another thread, for bch2_btree_trans_to_text();
 */
#define trans_for_each_path_from(_trans, _path, _idx, _start)		\
	for (_idx = _start;						\
	     (_path = __trans_next_path((_trans), &_idx));		\
	     _idx++)

#define trans_for_each_path(_trans, _path, _idx)			\
	trans_for_each_path_from(_trans, _path, _idx, 1)

static inline struct btree_path *next_btree_path(struct btree_trans *trans, struct btree_path *path)
{
	unsigned idx = path ? path->sorted_idx + 1 : 0;

	EBUG_ON(idx > trans->nr_sorted);

	return idx < trans->nr_sorted
		? trans->paths + trans->sorted[idx]
		: NULL;
}

static inline struct btree_path *prev_btree_path(struct btree_trans *trans, struct btree_path *path)
{
	unsigned idx = path ? path->sorted_idx : trans->nr_sorted;

	return idx
		? trans->paths + trans->sorted[idx - 1]
		: NULL;
}

#define trans_for_each_path_idx_inorder(_trans, _iter)			\
	for (_iter = (struct trans_for_each_path_inorder_iter) { 0 };	\
	     (_iter.path_idx = trans->sorted[_iter.sorted_idx],		\
	      _iter.sorted_idx < (_trans)->nr_sorted);			\
	     _iter.sorted_idx++)

struct trans_for_each_path_inorder_iter {
	btree_path_idx_t	sorted_idx;
	btree_path_idx_t	path_idx;
};

#define trans_for_each_path_inorder(_trans, _path, _iter)		\
	for (_iter = (struct trans_for_each_path_inorder_iter) { 0 };	\
	     (_iter.path_idx = trans->sorted[_iter.sorted_idx],		\
	      _path = (_trans)->paths + _iter.path_idx,			\
	      _iter.sorted_idx < (_trans)->nr_sorted);			\
	     _iter.sorted_idx++)

#define trans_for_each_path_inorder_reverse(_trans, _path, _i)		\
	for (_i = trans->nr_sorted - 1;					\
	     ((_path) = (_trans)->paths + trans->sorted[_i]), (_i) >= 0;\
	     --_i)

static inline bool __path_has_node(const struct btree_path *path,
				   const struct btree *b)
{
	return path->l[b->c.level].b == b &&
		btree_node_lock_seq_matches(path, b, b->c.level);
}

static inline struct btree_path *
__trans_next_path_with_node(struct btree_trans *trans, struct btree *b,
			    unsigned *idx)
{
	struct btree_path *path;

	while ((path = __trans_next_path(trans, idx)) &&
		!__path_has_node(path, b))
	       (*idx)++;

	return path;
}

#define trans_for_each_path_with_node(_trans, _b, _path, _iter)		\
	for (_iter = 1;							\
	     (_path = __trans_next_path_with_node((_trans), (_b), &_iter));\
	     _iter++)

btree_path_idx_t __bch2_btree_path_make_mut(struct btree_trans *, btree_path_idx_t,
					    bool, unsigned long);

static inline btree_path_idx_t __must_check
bch2_btree_path_make_mut(struct btree_trans *trans,
			 btree_path_idx_t path, bool intent,
			 unsigned long ip)
{
	if (trans->paths[path].ref > 1 ||
	    trans->paths[path].preserve)
		path = __bch2_btree_path_make_mut(trans, path, intent, ip);
	trans->paths[path].should_be_locked = false;
	return path;
}

btree_path_idx_t __must_check
__bch2_btree_path_set_pos(struct btree_trans *, btree_path_idx_t,
			  struct bpos, bool, unsigned long);

static inline btree_path_idx_t __must_check
bch2_btree_path_set_pos(struct btree_trans *trans,
			btree_path_idx_t path, struct bpos new_pos,
			bool intent, unsigned long ip)
{
	return !bpos_eq(new_pos, trans->paths[path].pos)
		? __bch2_btree_path_set_pos(trans, path, new_pos, intent, ip)
		: path;
}

int __must_check bch2_btree_path_traverse_one(struct btree_trans *,
					      btree_path_idx_t,
					      unsigned, unsigned long);

static inline void bch2_trans_verify_not_unlocked(struct btree_trans *);

static inline int __must_check bch2_btree_path_traverse(struct btree_trans *trans,
					  btree_path_idx_t path, unsigned flags)
{
	bch2_trans_verify_not_unlocked(trans);

	if (trans->paths[path].uptodate < BTREE_ITER_NEED_RELOCK)
		return 0;

	return bch2_btree_path_traverse_one(trans, path, flags, _RET_IP_);
}

btree_path_idx_t bch2_path_get(struct btree_trans *, enum btree_id, struct bpos,
				 unsigned, unsigned, unsigned, unsigned long);
btree_path_idx_t bch2_path_get_unlocked_mut(struct btree_trans *, enum btree_id,
					    unsigned, struct bpos);

struct bkey_s_c bch2_btree_path_peek_slot(struct btree_path *, struct bkey *);

/*
 * bch2_btree_path_peek_slot() for a cached iterator might return a key in a
 * different snapshot:
 */
static inline struct bkey_s_c bch2_btree_path_peek_slot_exact(struct btree_path *path, struct bkey *u)
{
	struct bkey_s_c k = bch2_btree_path_peek_slot(path, u);

	if (k.k && bpos_eq(path->pos, k.k->p))
		return k;

	bkey_init(u);
	u->p = path->pos;
	return (struct bkey_s_c) { u, NULL };
}

struct bkey_i *bch2_btree_journal_peek_slot(struct btree_trans *,
					struct btree_iter *, struct bpos);

void bch2_btree_path_level_init(struct btree_trans *, struct btree_path *, struct btree *);

int __bch2_trans_mutex_lock(struct btree_trans *, struct mutex *);

static inline int bch2_trans_mutex_lock(struct btree_trans *trans, struct mutex *lock)
{
	return mutex_trylock(lock)
		? 0
		: __bch2_trans_mutex_lock(trans, lock);
}

#ifdef CONFIG_BCACHEFS_DEBUG
void bch2_trans_verify_paths(struct btree_trans *);
void bch2_assert_pos_locked(struct btree_trans *, enum btree_id,
			    struct bpos, bool);
#else
static inline void bch2_trans_verify_paths(struct btree_trans *trans) {}
static inline void bch2_assert_pos_locked(struct btree_trans *trans, enum btree_id id,
					  struct bpos pos, bool key_cache) {}
#endif

void bch2_btree_path_fix_key_modified(struct btree_trans *trans,
				      struct btree *, struct bkey_packed *);
void bch2_btree_node_iter_fix(struct btree_trans *trans, struct btree_path *,
			      struct btree *, struct btree_node_iter *,
			      struct bkey_packed *, unsigned, unsigned);

int bch2_btree_path_relock_intent(struct btree_trans *, struct btree_path *);

void bch2_path_put(struct btree_trans *, btree_path_idx_t, bool);

int bch2_trans_relock(struct btree_trans *);
int bch2_trans_relock_notrace(struct btree_trans *);
void bch2_trans_unlock(struct btree_trans *);
void bch2_trans_unlock_long(struct btree_trans *);

static inline int trans_was_restarted(struct btree_trans *trans, u32 restart_count)
{
	return restart_count != trans->restart_count
		? -BCH_ERR_transaction_restart_nested
		: 0;
}

void __noreturn bch2_trans_restart_error(struct btree_trans *, u32);

static inline void bch2_trans_verify_not_restarted(struct btree_trans *trans,
						   u32 restart_count)
{
	if (trans_was_restarted(trans, restart_count))
		bch2_trans_restart_error(trans, restart_count);
}

void __noreturn bch2_trans_in_restart_error(struct btree_trans *);

static inline void bch2_trans_verify_not_in_restart(struct btree_trans *trans)
{
	if (trans->restarted)
		bch2_trans_in_restart_error(trans);
}

void __noreturn bch2_trans_unlocked_error(struct btree_trans *);

static inline void bch2_trans_verify_not_unlocked(struct btree_trans *trans)
{
	if (!trans->locked)
		bch2_trans_unlocked_error(trans);
}

__always_inline
static int btree_trans_restart_nounlock(struct btree_trans *trans, int err)
{
	BUG_ON(err <= 0);
	BUG_ON(!bch2_err_matches(-err, BCH_ERR_transaction_restart));

	trans->restarted = err;
	trans->last_restarted_ip = _THIS_IP_;
	return -err;
}

__always_inline
static int btree_trans_restart(struct btree_trans *trans, int err)
{
	btree_trans_restart_nounlock(trans, err);
	return -err;
}

bool bch2_btree_node_upgrade(struct btree_trans *,
			     struct btree_path *, unsigned);

void __bch2_btree_path_downgrade(struct btree_trans *, struct btree_path *, unsigned);

static inline void bch2_btree_path_downgrade(struct btree_trans *trans,
					     struct btree_path *path)
{
	unsigned new_locks_want = path->level + !!path->intent_ref;

	if (path->locks_want > new_locks_want)
		__bch2_btree_path_downgrade(trans, path, new_locks_want);
}

void bch2_trans_downgrade(struct btree_trans *);

void bch2_trans_node_add(struct btree_trans *trans, struct btree_path *, struct btree *);
void bch2_trans_node_reinit_iter(struct btree_trans *, struct btree *);

int __must_check __bch2_btree_iter_traverse(struct btree_iter *iter);
int __must_check bch2_btree_iter_traverse(struct btree_iter *);

struct btree *bch2_btree_iter_peek_node(struct btree_iter *);
struct btree *bch2_btree_iter_peek_node_and_restart(struct btree_iter *);
struct btree *bch2_btree_iter_next_node(struct btree_iter *);

struct bkey_s_c bch2_btree_iter_peek_upto(struct btree_iter *, struct bpos);
struct bkey_s_c bch2_btree_iter_next(struct btree_iter *);

static inline struct bkey_s_c bch2_btree_iter_peek(struct btree_iter *iter)
{
	return bch2_btree_iter_peek_upto(iter, SPOS_MAX);
}

struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *);
struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *);

struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *);
struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *);
struct bkey_s_c bch2_btree_iter_prev_slot(struct btree_iter *);

bool bch2_btree_iter_advance(struct btree_iter *);
bool bch2_btree_iter_rewind(struct btree_iter *);

static inline void __bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos)
{
	iter->k.type = KEY_TYPE_deleted;
	iter->k.p.inode		= iter->pos.inode	= new_pos.inode;
	iter->k.p.offset	= iter->pos.offset	= new_pos.offset;
	iter->k.p.snapshot	= iter->pos.snapshot	= new_pos.snapshot;
	iter->k.size = 0;
}

static inline void bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos)
{
	struct btree_trans *trans = iter->trans;

	if (unlikely(iter->update_path))
		bch2_path_put(trans, iter->update_path,
			      iter->flags & BTREE_ITER_intent);
	iter->update_path = 0;

	if (!(iter->flags & BTREE_ITER_all_snapshots))
		new_pos.snapshot = iter->snapshot;

	__bch2_btree_iter_set_pos(iter, new_pos);
}

static inline void bch2_btree_iter_set_pos_to_extent_start(struct btree_iter *iter)
{
	BUG_ON(!(iter->flags & BTREE_ITER_is_extents));
	iter->pos = bkey_start_pos(&iter->k);
}

static inline void bch2_btree_iter_set_snapshot(struct btree_iter *iter, u32 snapshot)
{
	struct bpos pos = iter->pos;

	iter->snapshot = snapshot;
	pos.snapshot = snapshot;
	bch2_btree_iter_set_pos(iter, pos);
}

void bch2_trans_iter_exit(struct btree_trans *, struct btree_iter *);

static inline unsigned __bch2_btree_iter_flags(struct btree_trans *trans,
					       unsigned btree_id,
					       unsigned flags)
{
	if (!(flags & (BTREE_ITER_all_snapshots|BTREE_ITER_not_extents)) &&
	    btree_id_is_extents(btree_id))
		flags |= BTREE_ITER_is_extents;

	if (!(flags & BTREE_ITER_snapshot_field) &&
	    !btree_type_has_snapshot_field(btree_id))
		flags &= ~BTREE_ITER_all_snapshots;

	if (!(flags & BTREE_ITER_all_snapshots) &&
	    btree_type_has_snapshots(btree_id))
		flags |= BTREE_ITER_filter_snapshots;

	if (trans->journal_replay_not_finished)
		flags |= BTREE_ITER_with_journal;

	return flags;
}

static inline unsigned bch2_btree_iter_flags(struct btree_trans *trans,
					     unsigned btree_id,
					     unsigned flags)
{
	if (!btree_id_cached(trans->c, btree_id)) {
		flags &= ~BTREE_ITER_cached;
		flags &= ~BTREE_ITER_with_key_cache;
	} else if (!(flags & BTREE_ITER_cached))
		flags |= BTREE_ITER_with_key_cache;

	return __bch2_btree_iter_flags(trans, btree_id, flags);
}

static inline void bch2_trans_iter_init_common(struct btree_trans *trans,
					  struct btree_iter *iter,
					  unsigned btree_id, struct bpos pos,
					  unsigned locks_want,
					  unsigned depth,
					  unsigned flags,
					  unsigned long ip)
{
	iter->trans		= trans;
	iter->update_path	= 0;
	iter->key_cache_path	= 0;
	iter->btree_id		= btree_id;
	iter->min_depth		= 0;
	iter->flags		= flags;
	iter->snapshot		= pos.snapshot;
	iter->pos		= pos;
	iter->k			= POS_KEY(pos);
	iter->journal_idx	= 0;
#ifdef CONFIG_BCACHEFS_DEBUG
	iter->ip_allocated = ip;
#endif
	iter->path = bch2_path_get(trans, btree_id, iter->pos,
				   locks_want, depth, flags, ip);
}

void bch2_trans_iter_init_outlined(struct btree_trans *, struct btree_iter *,
			  enum btree_id, struct bpos, unsigned);

static inline void bch2_trans_iter_init(struct btree_trans *trans,
			  struct btree_iter *iter,
			  unsigned btree_id, struct bpos pos,
			  unsigned flags)
{
	if (__builtin_constant_p(btree_id) &&
	    __builtin_constant_p(flags))
		bch2_trans_iter_init_common(trans, iter, btree_id, pos, 0, 0,
				bch2_btree_iter_flags(trans, btree_id, flags),
				_THIS_IP_);
	else
		bch2_trans_iter_init_outlined(trans, iter, btree_id, pos, flags);
}

void bch2_trans_node_iter_init(struct btree_trans *, struct btree_iter *,
			       enum btree_id, struct bpos,
			       unsigned, unsigned, unsigned);
void bch2_trans_copy_iter(struct btree_iter *, struct btree_iter *);

void bch2_set_btree_iter_dontneed(struct btree_iter *);

void *__bch2_trans_kmalloc(struct btree_trans *, size_t);

static inline void *bch2_trans_kmalloc(struct btree_trans *trans, size_t size)
{
	size = roundup(size, 8);

	if (likely(trans->mem_top + size <= trans->mem_bytes)) {
		void *p = trans->mem + trans->mem_top;

		trans->mem_top += size;
		memset(p, 0, size);
		return p;
	} else {
		return __bch2_trans_kmalloc(trans, size);
	}
}

static inline void *bch2_trans_kmalloc_nomemzero(struct btree_trans *trans, size_t size)
{
	size = round_up(size, 8);

	if (likely(trans->mem_top + size <= trans->mem_bytes)) {
		void *p = trans->mem + trans->mem_top;

		trans->mem_top += size;
		return p;
	} else {
		return __bch2_trans_kmalloc(trans, size);
	}
}

static inline struct bkey_s_c __bch2_bkey_get_iter(struct btree_trans *trans,
				struct btree_iter *iter,
				unsigned btree_id, struct bpos pos,
				unsigned flags, unsigned type)
{
	struct bkey_s_c k;

	bch2_trans_iter_init(trans, iter, btree_id, pos, flags);
	k = bch2_btree_iter_peek_slot(iter);

	if (!bkey_err(k) && type && k.k->type != type)
		k = bkey_s_c_err(-BCH_ERR_ENOENT_bkey_type_mismatch);
	if (unlikely(bkey_err(k)))
		bch2_trans_iter_exit(trans, iter);
	return k;
}

static inline struct bkey_s_c bch2_bkey_get_iter(struct btree_trans *trans,
				struct btree_iter *iter,
				unsigned btree_id, struct bpos pos,
				unsigned flags)
{
	return __bch2_bkey_get_iter(trans, iter, btree_id, pos, flags, 0);
}

#define bch2_bkey_get_iter_typed(_trans, _iter, _btree_id, _pos, _flags, _type)\
	bkey_s_c_to_##_type(__bch2_bkey_get_iter(_trans, _iter,			\
				       _btree_id, _pos, _flags, KEY_TYPE_##_type))

static inline int __bch2_bkey_get_val_typed(struct btree_trans *trans,
				unsigned btree_id, struct bpos pos,
				unsigned flags, unsigned type,
				unsigned val_size, void *val)
{
	struct btree_iter iter;
	struct bkey_s_c k;
	int ret;

	k = __bch2_bkey_get_iter(trans, &iter, btree_id, pos, flags, type);
	ret = bkey_err(k);
	if (!ret) {
		unsigned b = min_t(unsigned, bkey_val_bytes(k.k), val_size);

		memcpy(val, k.v, b);
		if (unlikely(b < sizeof(*val)))
			memset((void *) val + b, 0, sizeof(*val) - b);
		bch2_trans_iter_exit(trans, &iter);
	}

	return ret;
}

#define bch2_bkey_get_val_typed(_trans, _btree_id, _pos, _flags, _type, _val)\
	__bch2_bkey_get_val_typed(_trans, _btree_id, _pos, _flags,	\
				  KEY_TYPE_##_type, sizeof(*_val), _val)

void bch2_trans_srcu_unlock(struct btree_trans *);

u32 bch2_trans_begin(struct btree_trans *);

/*
 * XXX
 * this does not handle transaction restarts from bch2_btree_iter_next_node()
 * correctly
 */
#define __for_each_btree_node(_trans, _iter, _btree_id, _start,		\
			      _locks_want, _depth, _flags, _b, _ret)	\
	for (bch2_trans_node_iter_init((_trans), &(_iter), (_btree_id),	\
				_start, _locks_want, _depth, _flags);	\
	     (_b) = bch2_btree_iter_peek_node_and_restart(&(_iter)),	\
	     !((_ret) = PTR_ERR_OR_ZERO(_b)) && (_b);			\
	     (_b) = bch2_btree_iter_next_node(&(_iter)))

#define for_each_btree_node(_trans, _iter, _btree_id, _start,		\
			    _flags, _b, _ret)				\
	__for_each_btree_node(_trans, _iter, _btree_id, _start,		\
			      0, 0, _flags, _b, _ret)

static inline struct bkey_s_c bch2_btree_iter_peek_prev_type(struct btree_iter *iter,
							     unsigned flags)
{
	return  flags & BTREE_ITER_slots      ? bch2_btree_iter_peek_slot(iter) :
						bch2_btree_iter_peek_prev(iter);
}

static inline struct bkey_s_c bch2_btree_iter_peek_type(struct btree_iter *iter,
							unsigned flags)
{
	return  flags & BTREE_ITER_slots      ? bch2_btree_iter_peek_slot(iter) :
						bch2_btree_iter_peek(iter);
}

static inline struct bkey_s_c bch2_btree_iter_peek_upto_type(struct btree_iter *iter,
							     struct bpos end,
							     unsigned flags)
{
	if (!(flags & BTREE_ITER_slots))
		return bch2_btree_iter_peek_upto(iter, end);

	if (bkey_gt(iter->pos, end))
		return bkey_s_c_null;

	return bch2_btree_iter_peek_slot(iter);
}

int __bch2_btree_trans_too_many_iters(struct btree_trans *);

static inline int btree_trans_too_many_iters(struct btree_trans *trans)
{
	if (bitmap_weight(trans->paths_allocated, trans->nr_paths) > BTREE_ITER_NORMAL_LIMIT - 8)
		return __bch2_btree_trans_too_many_iters(trans);

	return 0;
}

/*
 * goto instead of loop, so that when used inside for_each_btree_key2()
 * break/continue work correctly
 */
#define lockrestart_do(_trans, _do)					\
({									\
	__label__ transaction_restart;					\
	u32 _restart_count;						\
	int _ret2;							\
transaction_restart:							\
	_restart_count = bch2_trans_begin(_trans);			\
	_ret2 = (_do);							\
									\
	if (bch2_err_matches(_ret2, BCH_ERR_transaction_restart))	\
		goto transaction_restart;				\
									\
	if (!_ret2)							\
		bch2_trans_verify_not_restarted(_trans, _restart_count);\
	_ret2;								\
})

/*
 * nested_lockrestart_do(), nested_commit_do():
 *
 * These are like lockrestart_do() and commit_do(), with two differences:
 *
 *  - We don't call bch2_trans_begin() unless we had a transaction restart
 *  - We return -BCH_ERR_transaction_restart_nested if we succeeded after a
 *  transaction restart
 */
#define nested_lockrestart_do(_trans, _do)				\
({									\
	u32 _restart_count, _orig_restart_count;			\
	int _ret2;							\
									\
	_restart_count = _orig_restart_count = (_trans)->restart_count;	\
									\
	while (bch2_err_matches(_ret2 = (_do), BCH_ERR_transaction_restart))\
		_restart_count = bch2_trans_begin(_trans);		\
									\
	if (!_ret2)							\
		bch2_trans_verify_not_restarted(_trans, _restart_count);\
									\
	_ret2 ?: trans_was_restarted(_trans, _restart_count);		\
})

#define for_each_btree_key_upto_continue(_trans, _iter,			\
					 _end, _flags, _k, _do)		\
({									\
	struct bkey_s_c _k;						\
	int _ret3 = 0;							\
									\
	do {								\
		_ret3 = lockrestart_do(_trans, ({			\
			(_k) = bch2_btree_iter_peek_upto_type(&(_iter),	\
						_end, (_flags));	\
			if (!(_k).k)					\
				break;					\
									\
			bkey_err(_k) ?: (_do);				\
		}));							\
	} while (!_ret3 && bch2_btree_iter_advance(&(_iter)));		\
									\
	bch2_trans_iter_exit((_trans), &(_iter));			\
	_ret3;								\
})

#define for_each_btree_key_continue(_trans, _iter, _flags, _k, _do)	\
	for_each_btree_key_upto_continue(_trans, _iter, SPOS_MAX, _flags, _k, _do)

#define for_each_btree_key_upto(_trans, _iter, _btree_id,		\
				_start, _end, _flags, _k, _do)		\
({									\
	bch2_trans_begin(trans);					\
									\
	struct btree_iter _iter;					\
	bch2_trans_iter_init((_trans), &(_iter), (_btree_id),		\
			     (_start), (_flags));			\
									\
	for_each_btree_key_upto_continue(_trans, _iter, _end, _flags, _k, _do);\
})

#define for_each_btree_key(_trans, _iter, _btree_id,			\
			   _start, _flags, _k, _do)			\
	for_each_btree_key_upto(_trans, _iter, _btree_id, _start,	\
				 SPOS_MAX, _flags, _k, _do)

#define for_each_btree_key_reverse(_trans, _iter, _btree_id,		\
				   _start, _flags, _k, _do)		\
({									\
	struct btree_iter _iter;					\
	struct bkey_s_c _k;						\
	int _ret3 = 0;							\
									\
	bch2_trans_iter_init((_trans), &(_iter), (_btree_id),		\
			     (_start), (_flags));			\
									\
	do {								\
		_ret3 = lockrestart_do(_trans, ({			\
			(_k) = bch2_btree_iter_peek_prev_type(&(_iter),	\
							(_flags));	\
			if (!(_k).k)					\
				break;					\
									\
			bkey_err(_k) ?: (_do);				\
		}));							\
	} while (!_ret3 && bch2_btree_iter_rewind(&(_iter)));		\
									\
	bch2_trans_iter_exit((_trans), &(_iter));			\
	_ret3;								\
})

#define for_each_btree_key_commit(_trans, _iter, _btree_id,		\
				  _start, _iter_flags, _k,		\
				  _disk_res, _journal_seq, _commit_flags,\
				  _do)					\
	for_each_btree_key(_trans, _iter, _btree_id, _start, _iter_flags, _k,\
			    (_do) ?: bch2_trans_commit(_trans, (_disk_res),\
					(_journal_seq), (_commit_flags)))

#define for_each_btree_key_reverse_commit(_trans, _iter, _btree_id,	\
				  _start, _iter_flags, _k,		\
				  _disk_res, _journal_seq, _commit_flags,\
				  _do)					\
	for_each_btree_key_reverse(_trans, _iter, _btree_id, _start, _iter_flags, _k,\
			    (_do) ?: bch2_trans_commit(_trans, (_disk_res),\
					(_journal_seq), (_commit_flags)))

#define for_each_btree_key_upto_commit(_trans, _iter, _btree_id,	\
				  _start, _end, _iter_flags, _k,	\
				  _disk_res, _journal_seq, _commit_flags,\
				  _do)					\
	for_each_btree_key_upto(_trans, _iter, _btree_id, _start, _end, _iter_flags, _k,\
			    (_do) ?: bch2_trans_commit(_trans, (_disk_res),\
					(_journal_seq), (_commit_flags)))

struct bkey_s_c bch2_btree_iter_peek_and_restart_outlined(struct btree_iter *);

static inline struct bkey_s_c
__bch2_btree_iter_peek_and_restart(struct btree_trans *trans,
				   struct btree_iter *iter, unsigned flags)
{
	struct bkey_s_c k;

	while (btree_trans_too_many_iters(trans) ||
	       (k = bch2_btree_iter_peek_type(iter, flags),
		bch2_err_matches(bkey_err(k), BCH_ERR_transaction_restart)))
		bch2_trans_begin(trans);

	return k;
}

#define for_each_btree_key_upto_norestart(_trans, _iter, _btree_id,	\
			   _start, _end, _flags, _k, _ret)		\
	for (bch2_trans_iter_init((_trans), &(_iter), (_btree_id),	\
				  (_start), (_flags));			\
	     (_k) = bch2_btree_iter_peek_upto_type(&(_iter), _end, _flags),\
	     !((_ret) = bkey_err(_k)) && (_k).k;			\
	     bch2_btree_iter_advance(&(_iter)))

#define for_each_btree_key_upto_continue_norestart(_iter, _end, _flags, _k, _ret)\
	for (;									\
	     (_k) = bch2_btree_iter_peek_upto_type(&(_iter), _end, _flags),	\
	     !((_ret) = bkey_err(_k)) && (_k).k;				\
	     bch2_btree_iter_advance(&(_iter)))

#define for_each_btree_key_norestart(_trans, _iter, _btree_id,		\
			   _start, _flags, _k, _ret)			\
	for_each_btree_key_upto_norestart(_trans, _iter, _btree_id, _start,\
					  SPOS_MAX, _flags, _k, _ret)

#define for_each_btree_key_continue_norestart(_iter, _flags, _k, _ret)	\
	for_each_btree_key_upto_continue_norestart(_iter, SPOS_MAX, _flags, _k, _ret)

/*
 * This should not be used in a fastpath, without first trying _do in
 * nonblocking mode - it will cause excessive transaction restarts and
 * potentially livelocking:
 */
#define drop_locks_do(_trans, _do)					\
({									\
	bch2_trans_unlock(_trans);					\
	(_do) ?: bch2_trans_relock(_trans);				\
})

#define allocate_dropping_locks_errcode(_trans, _do)			\
({									\
	gfp_t _gfp = GFP_NOWAIT|__GFP_NOWARN;				\
	int _ret = _do;							\
									\
	if (bch2_err_matches(_ret, ENOMEM)) {				\
		_gfp = GFP_KERNEL;					\
		_ret = drop_locks_do(trans, _do);			\
	}								\
	_ret;								\
})

#define allocate_dropping_locks(_trans, _ret, _do)			\
({									\
	gfp_t _gfp = GFP_NOWAIT|__GFP_NOWARN;				\
	typeof(_do) _p = _do;						\
									\
	_ret = 0;							\
	if (unlikely(!_p)) {						\
		_gfp = GFP_KERNEL;					\
		_ret = drop_locks_do(trans, ((_p = _do), 0));		\
	}								\
	_p;								\
})

void bch2_trans_updates_to_text(struct printbuf *, struct btree_trans *);
void bch2_btree_path_to_text(struct printbuf *, struct btree_trans *, btree_path_idx_t);
void bch2_trans_paths_to_text(struct printbuf *, struct btree_trans *);
void bch2_dump_trans_updates(struct btree_trans *);
void bch2_dump_trans_paths_updates(struct btree_trans *);

struct btree_trans *__bch2_trans_get(struct bch_fs *, unsigned);
void bch2_trans_put(struct btree_trans *);

extern const char *bch2_btree_transaction_fns[BCH_TRANSACTIONS_NR];
unsigned bch2_trans_get_fn_idx(const char *);

#define bch2_trans_get(_c)						\
({									\
	static unsigned trans_fn_idx;					\
									\
	if (unlikely(!trans_fn_idx))					\
		trans_fn_idx = bch2_trans_get_fn_idx(__func__);		\
	__bch2_trans_get(_c, trans_fn_idx);				\
})

void bch2_btree_trans_to_text(struct printbuf *, struct btree_trans *);

void bch2_fs_btree_iter_exit(struct bch_fs *);
void bch2_fs_btree_iter_init_early(struct bch_fs *);
int bch2_fs_btree_iter_init(struct bch_fs *);

#endif /* _BCACHEFS_BTREE_ITER_H */