1// SPDX-License-Identifier: GPL-2.0
2
3#include "bcachefs.h"
4#include "bkey_buf.h"
5#include "bset.h"
6#include "btree_cache.h"
7#include "btree_journal_iter.h"
8#include "journal_io.h"
9
10#include <linux/sort.h>
11
12/*
13 * For managing keys we read from the journal: until journal replay works normal
14 * btree lookups need to be able to find and return keys from the journal where
15 * they overwrite what's in the btree, so we have a special iterator and
16 * operations for the regular btree iter code to use:
17 */
18
19static int __journal_key_cmp(enum btree_id	l_btree_id,
20			     unsigned		l_level,
21			     struct bpos	l_pos,
22			     const struct journal_key *r)
23{
24	return (cmp_int(l_btree_id,	r->btree_id) ?:
25		cmp_int(l_level,	r->level) ?:
26		bpos_cmp(l_pos,	r->k->k.p));
27}
28
29static int journal_key_cmp(const struct journal_key *l, const struct journal_key *r)
30{
31	return __journal_key_cmp(l->btree_id, l->level, l->k->k.p, r);
32}
33
34static inline size_t idx_to_pos(struct journal_keys *keys, size_t idx)
35{
36	size_t gap_size = keys->size - keys->nr;
37
38	if (idx >= keys->gap)
39		idx += gap_size;
40	return idx;
41}
42
43static inline struct journal_key *idx_to_key(struct journal_keys *keys, size_t idx)
44{
45	return keys->data + idx_to_pos(keys, idx);
46}
47
48static size_t __bch2_journal_key_search(struct journal_keys *keys,
49					enum btree_id id, unsigned level,
50					struct bpos pos)
51{
52	size_t l = 0, r = keys->nr, m;
53
54	while (l < r) {
55		m = l + ((r - l) >> 1);
56		if (__journal_key_cmp(id, level, pos, idx_to_key(keys, m)) > 0)
57			l = m + 1;
58		else
59			r = m;
60	}
61
62	BUG_ON(l < keys->nr &&
63	       __journal_key_cmp(id, level, pos, idx_to_key(keys, l)) > 0);
64
65	BUG_ON(l &&
66	       __journal_key_cmp(id, level, pos, idx_to_key(keys, l - 1)) <= 0);
67
68	return l;
69}
70
71static size_t bch2_journal_key_search(struct journal_keys *keys,
72				      enum btree_id id, unsigned level,
73				      struct bpos pos)
74{
75	return idx_to_pos(keys, __bch2_journal_key_search(keys, id, level, pos));
76}
77
78/* Returns first non-overwritten key >= search key: */
79struct bkey_i *bch2_journal_keys_peek_upto(struct bch_fs *c, enum btree_id btree_id,
80					   unsigned level, struct bpos pos,
81					   struct bpos end_pos, size_t *idx)
82{
83	struct journal_keys *keys = &c->journal_keys;
84	unsigned iters = 0;
85	struct journal_key *k;
86
87	BUG_ON(*idx > keys->nr);
88search:
89	if (!*idx)
90		*idx = __bch2_journal_key_search(keys, btree_id, level, pos);
91
92	while (*idx &&
93	       __journal_key_cmp(btree_id, level, end_pos, idx_to_key(keys, *idx - 1)) <= 0) {
94		--(*idx);
95		iters++;
96		if (iters == 10) {
97			*idx = 0;
98			goto search;
99		}
100	}
101
102	while ((k = *idx < keys->nr ? idx_to_key(keys, *idx) : NULL)) {
103		if (__journal_key_cmp(btree_id, level, end_pos, k) < 0)
104			return NULL;
105
106		if (k->overwritten) {
107			(*idx)++;
108			continue;
109		}
110
111		if (__journal_key_cmp(btree_id, level, pos, k) <= 0)
112			return k->k;
113
114		(*idx)++;
115		iters++;
116		if (iters == 10) {
117			*idx = 0;
118			goto search;
119		}
120	}
121
122	return NULL;
123}
124
125struct bkey_i *bch2_journal_keys_peek_slot(struct bch_fs *c, enum btree_id btree_id,
126					   unsigned level, struct bpos pos)
127{
128	size_t idx = 0;
129
130	return bch2_journal_keys_peek_upto(c, btree_id, level, pos, pos, &idx);
131}
132
133static void journal_iter_verify(struct journal_iter *iter)
134{
135	struct journal_keys *keys = iter->keys;
136	size_t gap_size = keys->size - keys->nr;
137
138	BUG_ON(iter->idx >= keys->gap &&
139	       iter->idx <  keys->gap + gap_size);
140
141	if (iter->idx < keys->size) {
142		struct journal_key *k = keys->data + iter->idx;
143
144		int cmp = cmp_int(k->btree_id,	iter->btree_id) ?:
145			  cmp_int(k->level,	iter->level);
146		BUG_ON(cmp < 0);
147	}
148}
149
150static void journal_iters_fix(struct bch_fs *c)
151{
152	struct journal_keys *keys = &c->journal_keys;
153	/* The key we just inserted is immediately before the gap: */
154	size_t gap_end = keys->gap + (keys->size - keys->nr);
155	struct journal_key *new_key = &keys->data[keys->gap - 1];
156	struct journal_iter *iter;
157
158	/*
159	 * If an iterator points one after the key we just inserted, decrement
160	 * the iterator so it points at the key we just inserted - if the
161	 * decrement was unnecessary, bch2_btree_and_journal_iter_peek() will
162	 * handle that:
163	 */
164	list_for_each_entry(iter, &c->journal_iters, list) {
165		journal_iter_verify(iter);
166		if (iter->idx		== gap_end &&
167		    new_key->btree_id	== iter->btree_id &&
168		    new_key->level	== iter->level)
169			iter->idx = keys->gap - 1;
170		journal_iter_verify(iter);
171	}
172}
173
174static void journal_iters_move_gap(struct bch_fs *c, size_t old_gap, size_t new_gap)
175{
176	struct journal_keys *keys = &c->journal_keys;
177	struct journal_iter *iter;
178	size_t gap_size = keys->size - keys->nr;
179
180	list_for_each_entry(iter, &c->journal_iters, list) {
181		if (iter->idx > old_gap)
182			iter->idx -= gap_size;
183		if (iter->idx >= new_gap)
184			iter->idx += gap_size;
185	}
186}
187
188int bch2_journal_key_insert_take(struct bch_fs *c, enum btree_id id,
189				 unsigned level, struct bkey_i *k)
190{
191	struct journal_key n = {
192		.btree_id	= id,
193		.level		= level,
194		.k		= k,
195		.allocated	= true,
196		/*
197		 * Ensure these keys are done last by journal replay, to unblock
198		 * journal reclaim:
199		 */
200		.journal_seq	= U32_MAX,
201	};
202	struct journal_keys *keys = &c->journal_keys;
203	size_t idx = bch2_journal_key_search(keys, id, level, k->k.p);
204
205	BUG_ON(test_bit(BCH_FS_rw, &c->flags));
206
207	if (idx < keys->size &&
208	    journal_key_cmp(&n, &keys->data[idx]) == 0) {
209		if (keys->data[idx].allocated)
210			kfree(keys->data[idx].k);
211		keys->data[idx] = n;
212		return 0;
213	}
214
215	if (idx > keys->gap)
216		idx -= keys->size - keys->nr;
217
218	size_t old_gap = keys->gap;
219
220	if (keys->nr == keys->size) {
221		journal_iters_move_gap(c, old_gap, keys->size);
222		old_gap = keys->size;
223
224		struct journal_keys new_keys = {
225			.nr			= keys->nr,
226			.size			= max_t(size_t, keys->size, 8) * 2,
227		};
228
229		new_keys.data = kvmalloc_array(new_keys.size, sizeof(new_keys.data[0]), GFP_KERNEL);
230		if (!new_keys.data) {
231			bch_err(c, "%s: error allocating new key array (size %zu)",
232				__func__, new_keys.size);
233			return -BCH_ERR_ENOMEM_journal_key_insert;
234		}
235
236		/* Since @keys was full, there was no gap: */
237		memcpy(new_keys.data, keys->data, sizeof(keys->data[0]) * keys->nr);
238		kvfree(keys->data);
239		keys->data	= new_keys.data;
240		keys->nr	= new_keys.nr;
241		keys->size	= new_keys.size;
242
243		/* And now the gap is at the end: */
244		keys->gap	= keys->nr;
245	}
246
247	journal_iters_move_gap(c, old_gap, idx);
248
249	move_gap(keys, idx);
250
251	keys->nr++;
252	keys->data[keys->gap++] = n;
253
254	journal_iters_fix(c);
255
256	return 0;
257}
258
259/*
260 * Can only be used from the recovery thread while we're still RO - can't be
261 * used once we've got RW, as journal_keys is at that point used by multiple
262 * threads:
263 */
264int bch2_journal_key_insert(struct bch_fs *c, enum btree_id id,
265			    unsigned level, struct bkey_i *k)
266{
267	struct bkey_i *n;
268	int ret;
269
270	n = kmalloc(bkey_bytes(&k->k), GFP_KERNEL);
271	if (!n)
272		return -BCH_ERR_ENOMEM_journal_key_insert;
273
274	bkey_copy(n, k);
275	ret = bch2_journal_key_insert_take(c, id, level, n);
276	if (ret)
277		kfree(n);
278	return ret;
279}
280
281int bch2_journal_key_delete(struct bch_fs *c, enum btree_id id,
282			    unsigned level, struct bpos pos)
283{
284	struct bkey_i whiteout;
285
286	bkey_init(&whiteout.k);
287	whiteout.k.p = pos;
288
289	return bch2_journal_key_insert(c, id, level, &whiteout);
290}
291
292bool bch2_key_deleted_in_journal(struct btree_trans *trans, enum btree_id btree,
293				 unsigned level, struct bpos pos)
294{
295	struct journal_keys *keys = &trans->c->journal_keys;
296	size_t idx = bch2_journal_key_search(keys, btree, level, pos);
297
298	if (!trans->journal_replay_not_finished)
299		return false;
300
301	return (idx < keys->size &&
302		keys->data[idx].btree_id	== btree &&
303		keys->data[idx].level		== level &&
304		bpos_eq(keys->data[idx].k->k.p, pos) &&
305		bkey_deleted(&keys->data[idx].k->k));
306}
307
308void bch2_journal_key_overwritten(struct bch_fs *c, enum btree_id btree,
309				  unsigned level, struct bpos pos)
310{
311	struct journal_keys *keys = &c->journal_keys;
312	size_t idx = bch2_journal_key_search(keys, btree, level, pos);
313
314	if (idx < keys->size &&
315	    keys->data[idx].btree_id	== btree &&
316	    keys->data[idx].level	== level &&
317	    bpos_eq(keys->data[idx].k->k.p, pos))
318		keys->data[idx].overwritten = true;
319}
320
321static void bch2_journal_iter_advance(struct journal_iter *iter)
322{
323	if (iter->idx < iter->keys->size) {
324		iter->idx++;
325		if (iter->idx == iter->keys->gap)
326			iter->idx += iter->keys->size - iter->keys->nr;
327	}
328}
329
330static struct bkey_s_c bch2_journal_iter_peek(struct journal_iter *iter)
331{
332	journal_iter_verify(iter);
333
334	while (iter->idx < iter->keys->size) {
335		struct journal_key *k = iter->keys->data + iter->idx;
336
337		int cmp = cmp_int(k->btree_id,	iter->btree_id) ?:
338			  cmp_int(k->level,	iter->level);
339		if (cmp > 0)
340			break;
341		BUG_ON(cmp);
342
343		if (!k->overwritten)
344			return bkey_i_to_s_c(k->k);
345
346		bch2_journal_iter_advance(iter);
347	}
348
349	return bkey_s_c_null;
350}
351
352static void bch2_journal_iter_exit(struct journal_iter *iter)
353{
354	list_del(&iter->list);
355}
356
357static void bch2_journal_iter_init(struct bch_fs *c,
358				   struct journal_iter *iter,
359				   enum btree_id id, unsigned level,
360				   struct bpos pos)
361{
362	iter->btree_id	= id;
363	iter->level	= level;
364	iter->keys	= &c->journal_keys;
365	iter->idx	= bch2_journal_key_search(&c->journal_keys, id, level, pos);
366
367	journal_iter_verify(iter);
368}
369
370static struct bkey_s_c bch2_journal_iter_peek_btree(struct btree_and_journal_iter *iter)
371{
372	return bch2_btree_node_iter_peek_unpack(&iter->node_iter,
373						iter->b, &iter->unpacked);
374}
375
376static void bch2_journal_iter_advance_btree(struct btree_and_journal_iter *iter)
377{
378	bch2_btree_node_iter_advance(&iter->node_iter, iter->b);
379}
380
381void bch2_btree_and_journal_iter_advance(struct btree_and_journal_iter *iter)
382{
383	if (bpos_eq(iter->pos, SPOS_MAX))
384		iter->at_end = true;
385	else
386		iter->pos = bpos_successor(iter->pos);
387}
388
389static void btree_and_journal_iter_prefetch(struct btree_and_journal_iter *_iter)
390{
391	struct btree_and_journal_iter iter = *_iter;
392	struct bch_fs *c = iter.trans->c;
393	unsigned level = iter.journal.level;
394	struct bkey_buf tmp;
395	unsigned nr = test_bit(BCH_FS_started, &c->flags)
396		? (level > 1 ? 0 :  2)
397		: (level > 1 ? 1 : 16);
398
399	iter.prefetch = false;
400	bch2_bkey_buf_init(&tmp);
401
402	while (nr--) {
403		bch2_btree_and_journal_iter_advance(&iter);
404		struct bkey_s_c k = bch2_btree_and_journal_iter_peek(&iter);
405		if (!k.k)
406			break;
407
408		bch2_bkey_buf_reassemble(&tmp, c, k);
409		bch2_btree_node_prefetch(iter.trans, NULL, tmp.k, iter.journal.btree_id, level - 1);
410	}
411
412	bch2_bkey_buf_exit(&tmp, c);
413}
414
415struct bkey_s_c bch2_btree_and_journal_iter_peek(struct btree_and_journal_iter *iter)
416{
417	struct bkey_s_c btree_k, journal_k = bkey_s_c_null, ret;
418
419	if (iter->prefetch && iter->journal.level)
420		btree_and_journal_iter_prefetch(iter);
421again:
422	if (iter->at_end)
423		return bkey_s_c_null;
424
425	while ((btree_k = bch2_journal_iter_peek_btree(iter)).k &&
426	       bpos_lt(btree_k.k->p, iter->pos))
427		bch2_journal_iter_advance_btree(iter);
428
429	if (iter->trans->journal_replay_not_finished)
430		while ((journal_k = bch2_journal_iter_peek(&iter->journal)).k &&
431		       bpos_lt(journal_k.k->p, iter->pos))
432			bch2_journal_iter_advance(&iter->journal);
433
434	ret = journal_k.k &&
435		(!btree_k.k || bpos_le(journal_k.k->p, btree_k.k->p))
436		? journal_k
437		: btree_k;
438
439	if (ret.k && iter->b && bpos_gt(ret.k->p, iter->b->data->max_key))
440		ret = bkey_s_c_null;
441
442	if (ret.k) {
443		iter->pos = ret.k->p;
444		if (bkey_deleted(ret.k)) {
445			bch2_btree_and_journal_iter_advance(iter);
446			goto again;
447		}
448	} else {
449		iter->pos = SPOS_MAX;
450		iter->at_end = true;
451	}
452
453	return ret;
454}
455
456void bch2_btree_and_journal_iter_exit(struct btree_and_journal_iter *iter)
457{
458	bch2_journal_iter_exit(&iter->journal);
459}
460
461void __bch2_btree_and_journal_iter_init_node_iter(struct btree_trans *trans,
462						  struct btree_and_journal_iter *iter,
463						  struct btree *b,
464						  struct btree_node_iter node_iter,
465						  struct bpos pos)
466{
467	memset(iter, 0, sizeof(*iter));
468
469	iter->trans = trans;
470	iter->b = b;
471	iter->node_iter = node_iter;
472	iter->pos = b->data->min_key;
473	iter->at_end = false;
474	INIT_LIST_HEAD(&iter->journal.list);
475
476	if (trans->journal_replay_not_finished) {
477		bch2_journal_iter_init(trans->c, &iter->journal, b->c.btree_id, b->c.level, pos);
478		if (!test_bit(BCH_FS_may_go_rw, &trans->c->flags))
479			list_add(&iter->journal.list, &trans->c->journal_iters);
480	}
481}
482
483/*
484 * this version is used by btree_gc before filesystem has gone RW and
485 * multithreaded, so uses the journal_iters list:
486 */
487void bch2_btree_and_journal_iter_init_node_iter(struct btree_trans *trans,
488						struct btree_and_journal_iter *iter,
489						struct btree *b)
490{
491	struct btree_node_iter node_iter;
492
493	bch2_btree_node_iter_init_from_start(&node_iter, b);
494	__bch2_btree_and_journal_iter_init_node_iter(trans, iter, b, node_iter, b->data->min_key);
495}
496
497/* sort and dedup all keys in the journal: */
498
499void bch2_journal_entries_free(struct bch_fs *c)
500{
501	struct journal_replay **i;
502	struct genradix_iter iter;
503
504	genradix_for_each(&c->journal_entries, iter, i)
505		kvfree(*i);
506	genradix_free(&c->journal_entries);
507}
508
509/*
510 * When keys compare equal, oldest compares first:
511 */
512static int journal_sort_key_cmp(const void *_l, const void *_r)
513{
514	const struct journal_key *l = _l;
515	const struct journal_key *r = _r;
516
517	return  journal_key_cmp(l, r) ?:
518		cmp_int(l->journal_seq, r->journal_seq) ?:
519		cmp_int(l->journal_offset, r->journal_offset);
520}
521
522void bch2_journal_keys_put(struct bch_fs *c)
523{
524	struct journal_keys *keys = &c->journal_keys;
525
526	BUG_ON(atomic_read(&keys->ref) <= 0);
527
528	if (!atomic_dec_and_test(&keys->ref))
529		return;
530
531	move_gap(keys, keys->nr);
532
533	darray_for_each(*keys, i)
534		if (i->allocated)
535			kfree(i->k);
536
537	kvfree(keys->data);
538	keys->data = NULL;
539	keys->nr = keys->gap = keys->size = 0;
540
541	bch2_journal_entries_free(c);
542}
543
544static void __journal_keys_sort(struct journal_keys *keys)
545{
546	sort(keys->data, keys->nr, sizeof(keys->data[0]), journal_sort_key_cmp, NULL);
547
548	struct journal_key *dst = keys->data;
549
550	darray_for_each(*keys, src) {
551		if (src + 1 < &darray_top(*keys) &&
552		    !journal_key_cmp(src, src + 1))
553			continue;
554
555		*dst++ = *src;
556	}
557
558	keys->nr = dst - keys->data;
559}
560
561int bch2_journal_keys_sort(struct bch_fs *c)
562{
563	struct genradix_iter iter;
564	struct journal_replay *i, **_i;
565	struct journal_keys *keys = &c->journal_keys;
566	size_t nr_read = 0;
567
568	genradix_for_each(&c->journal_entries, iter, _i) {
569		i = *_i;
570
571		if (journal_replay_ignore(i))
572			continue;
573
574		cond_resched();
575
576		for_each_jset_key(k, entry, &i->j) {
577			struct journal_key n = (struct journal_key) {
578				.btree_id	= entry->btree_id,
579				.level		= entry->level,
580				.k		= k,
581				.journal_seq	= le64_to_cpu(i->j.seq),
582				.journal_offset	= k->_data - i->j._data,
583			};
584
585			if (darray_push(keys, n)) {
586				__journal_keys_sort(keys);
587
588				if (keys->nr * 8 > keys->size * 7) {
589					bch_err(c, "Too many journal keys for slowpath; have %zu compacted, buf size %zu, processed %zu keys at seq %llu",
590						keys->nr, keys->size, nr_read, le64_to_cpu(i->j.seq));
591					return -BCH_ERR_ENOMEM_journal_keys_sort;
592				}
593
594				BUG_ON(darray_push(keys, n));
595			}
596
597			nr_read++;
598		}
599	}
600
601	__journal_keys_sort(keys);
602	keys->gap = keys->nr;
603
604	bch_verbose(c, "Journal keys: %zu read, %zu after sorting and compacting", nr_read, keys->nr);
605	return 0;
606}
607
608void bch2_shoot_down_journal_keys(struct bch_fs *c, enum btree_id btree,
609				  unsigned level_min, unsigned level_max,
610				  struct bpos start, struct bpos end)
611{
612	struct journal_keys *keys = &c->journal_keys;
613	size_t dst = 0;
614
615	move_gap(keys, keys->nr);
616
617	darray_for_each(*keys, i)
618		if (!(i->btree_id == btree &&
619		      i->level >= level_min &&
620		      i->level <= level_max &&
621		      bpos_ge(i->k->k.p, start) &&
622		      bpos_le(i->k->k.p, end)))
623			keys->data[dst++] = *i;
624	keys->nr = keys->gap = dst;
625}
626