1 // SPDX-License-Identifier: GPL-2.0
4 #include "bkey_methods.h"
5 #include "btree_cache.h"
6 #include "btree_iter.h"
7 #include "btree_key_cache.h"
8 #include "btree_locking.h"
9 #include "btree_update.h"
14 #include <linux/prefetch.h>
15 #include <trace/events/bcachefs.h>
17 static inline bool is_btree_node(struct btree_iter *iter, unsigned l)
19 return l < BTREE_MAX_DEPTH &&
20 (unsigned long) iter->l[l].b >= 128;
23 static inline struct bpos btree_iter_search_key(struct btree_iter *iter)
25 struct bpos pos = iter->pos;
27 if ((iter->flags & BTREE_ITER_IS_EXTENTS) &&
28 bkey_cmp(pos, POS_MAX))
29 pos = bkey_successor(pos);
33 static inline bool btree_iter_pos_before_node(struct btree_iter *iter,
36 return bkey_cmp(btree_iter_search_key(iter), b->data->min_key) < 0;
39 static inline bool btree_iter_pos_after_node(struct btree_iter *iter,
42 return bkey_cmp(b->key.k.p, btree_iter_search_key(iter)) < 0;
45 static inline bool btree_iter_pos_in_node(struct btree_iter *iter,
48 return iter->btree_id == b->c.btree_id &&
49 !btree_iter_pos_before_node(iter, b) &&
50 !btree_iter_pos_after_node(iter, b);
53 /* Btree node locking: */
55 void bch2_btree_node_unlock_write(struct btree *b, struct btree_iter *iter)
57 bch2_btree_node_unlock_write_inlined(b, iter);
60 void __bch2_btree_node_lock_write(struct btree *b, struct btree_iter *iter)
62 struct btree_iter *linked;
65 EBUG_ON(!btree_node_intent_locked(iter, b->c.level));
67 trans_for_each_iter(iter->trans, linked)
68 if (linked->l[b->c.level].b == b &&
69 btree_node_read_locked(linked, b->c.level))
73 * Must drop our read locks before calling six_lock_write() -
74 * six_unlock() won't do wakeups until the reader count
75 * goes to 0, and it's safe because we have the node intent
78 atomic64_sub(__SIX_VAL(read_lock, readers),
79 &b->c.lock.state.counter);
80 btree_node_lock_type(iter->trans->c, b, SIX_LOCK_write);
81 atomic64_add(__SIX_VAL(read_lock, readers),
82 &b->c.lock.state.counter);
85 bool __bch2_btree_node_relock(struct btree_iter *iter, unsigned level)
87 struct btree *b = btree_iter_node(iter, level);
88 int want = __btree_lock_want(iter, level);
90 if (!is_btree_node(iter, level))
96 if (six_relock_type(&b->c.lock, want, iter->l[level].lock_seq) ||
97 (btree_node_lock_seq_matches(iter, b, level) &&
98 btree_node_lock_increment(iter->trans, b, level, want))) {
99 mark_btree_node_locked(iter, level, want);
106 static bool bch2_btree_node_upgrade(struct btree_iter *iter, unsigned level)
108 struct btree *b = iter->l[level].b;
110 EBUG_ON(btree_lock_want(iter, level) != BTREE_NODE_INTENT_LOCKED);
112 if (!is_btree_node(iter, level))
115 if (btree_node_intent_locked(iter, level))
121 if (btree_node_locked(iter, level)
122 ? six_lock_tryupgrade(&b->c.lock)
123 : six_relock_type(&b->c.lock, SIX_LOCK_intent, iter->l[level].lock_seq))
126 if (btree_node_lock_seq_matches(iter, b, level) &&
127 btree_node_lock_increment(iter->trans, b, level, BTREE_NODE_INTENT_LOCKED)) {
128 btree_node_unlock(iter, level);
134 mark_btree_node_intent_locked(iter, level);
138 static inline bool btree_iter_get_locks(struct btree_iter *iter,
139 bool upgrade, bool trace)
141 unsigned l = iter->level;
145 if (!btree_iter_node(iter, l))
149 ? bch2_btree_node_upgrade(iter, l)
150 : bch2_btree_node_relock(iter, l))) {
153 ? trace_node_upgrade_fail
154 : trace_node_relock_fail)(l, iter->l[l].lock_seq,
155 is_btree_node(iter, l)
157 : (unsigned long) iter->l[l].b,
158 is_btree_node(iter, l)
159 ? iter->l[l].b->c.lock.state.seq
163 btree_iter_set_dirty(iter, BTREE_ITER_NEED_TRAVERSE);
167 } while (l < iter->locks_want);
170 * When we fail to get a lock, we have to ensure that any child nodes
171 * can't be relocked so bch2_btree_iter_traverse has to walk back up to
172 * the node that we failed to relock:
174 while (fail_idx >= 0) {
175 btree_node_unlock(iter, fail_idx);
176 iter->l[fail_idx].b = BTREE_ITER_NO_NODE_GET_LOCKS;
180 if (iter->uptodate == BTREE_ITER_NEED_RELOCK)
181 iter->uptodate = BTREE_ITER_NEED_PEEK;
183 bch2_btree_trans_verify_locks(iter->trans);
185 return iter->uptodate < BTREE_ITER_NEED_RELOCK;
188 static struct bpos btree_node_pos(struct btree_bkey_cached_common *_b,
189 enum btree_iter_type type)
191 return type != BTREE_ITER_CACHED
192 ? container_of(_b, struct btree, c)->key.k.p
193 : container_of(_b, struct bkey_cached, c)->key.pos;
197 bool __bch2_btree_node_lock(struct btree *b, struct bpos pos,
198 unsigned level, struct btree_iter *iter,
199 enum six_lock_type type,
200 six_lock_should_sleep_fn should_sleep_fn,
203 struct btree_trans *trans = iter->trans;
204 struct btree_iter *linked;
205 u64 start_time = local_clock();
208 /* Check if it's safe to block: */
209 trans_for_each_iter(trans, linked) {
210 if (!linked->nodes_locked)
214 * Can't block taking an intent lock if we have _any_ nodes read
217 * - Our read lock blocks another thread with an intent lock on
218 * the same node from getting a write lock, and thus from
219 * dropping its intent lock
221 * - And the other thread may have multiple nodes intent locked:
222 * both the node we want to intent lock, and the node we
223 * already have read locked - deadlock:
225 if (type == SIX_LOCK_intent &&
226 linked->nodes_locked != linked->nodes_intent_locked) {
227 if (!(trans->nounlock)) {
228 linked->locks_want = max_t(unsigned,
230 __fls(linked->nodes_locked) + 1);
231 if (!btree_iter_get_locks(linked, true, false))
239 * Interior nodes must be locked before their descendants: if
240 * another iterator has possible descendants locked of the node
241 * we're about to lock, it must have the ancestors locked too:
243 if (linked->btree_id == iter->btree_id &&
244 level > __fls(linked->nodes_locked)) {
245 if (!(trans->nounlock)) {
247 max(level + 1, max_t(unsigned,
250 if (!btree_iter_get_locks(linked, true, false))
257 /* Must lock btree nodes in key order: */
258 if ((cmp_int(iter->btree_id, linked->btree_id) ?:
259 -cmp_int(btree_iter_type(iter), btree_iter_type(linked))) < 0)
262 if (iter->btree_id == linked->btree_id &&
263 btree_node_locked(linked, level) &&
264 bkey_cmp(pos, btree_node_pos((void *) linked->l[level].b,
265 btree_iter_type(linked))) <= 0)
269 * Recheck if this is a node we already have locked - since one
270 * of the get_locks() calls might've successfully
271 * upgraded/relocked it:
273 if (linked->l[level].b == b &&
274 btree_node_locked_type(linked, level) >= type) {
275 six_lock_increment(&b->c.lock, type);
280 if (unlikely(!ret)) {
281 trace_trans_restart_would_deadlock(iter->trans->ip);
285 if (six_trylock_type(&b->c.lock, type))
288 if (six_lock_type(&b->c.lock, type, should_sleep_fn, p))
291 bch2_time_stats_update(&trans->c->times[lock_to_time_stat(type)],
296 /* Btree iterator locking: */
298 #ifdef CONFIG_BCACHEFS_DEBUG
299 static void bch2_btree_iter_verify_locks(struct btree_iter *iter)
303 if (!(iter->trans->iters_linked & (1ULL << iter->idx))) {
304 BUG_ON(iter->nodes_locked);
308 for (l = 0; is_btree_node(iter, l); l++) {
309 if (iter->uptodate >= BTREE_ITER_NEED_RELOCK &&
310 !btree_node_locked(iter, l))
313 BUG_ON(btree_lock_want(iter, l) !=
314 btree_node_locked_type(iter, l));
318 void bch2_btree_trans_verify_locks(struct btree_trans *trans)
320 struct btree_iter *iter;
322 trans_for_each_iter_all(trans, iter)
323 bch2_btree_iter_verify_locks(iter);
326 static inline void bch2_btree_iter_verify_locks(struct btree_iter *iter) {}
330 bool bch2_btree_iter_relock(struct btree_iter *iter, bool trace)
332 return btree_iter_get_locks(iter, false, trace);
335 bool __bch2_btree_iter_upgrade(struct btree_iter *iter,
336 unsigned new_locks_want)
338 struct btree_iter *linked;
340 EBUG_ON(iter->locks_want >= new_locks_want);
342 iter->locks_want = new_locks_want;
344 if (btree_iter_get_locks(iter, true, true))
348 * Ancestor nodes must be locked before child nodes, so set locks_want
349 * on iterators that might lock ancestors before us to avoid getting
352 trans_for_each_iter(iter->trans, linked)
353 if (linked != iter &&
354 linked->btree_id == iter->btree_id &&
355 linked->locks_want < new_locks_want) {
356 linked->locks_want = new_locks_want;
357 btree_iter_get_locks(linked, true, false);
363 bool __bch2_btree_iter_upgrade_nounlock(struct btree_iter *iter,
364 unsigned new_locks_want)
366 unsigned l = iter->level;
368 EBUG_ON(iter->locks_want >= new_locks_want);
370 iter->locks_want = new_locks_want;
373 if (!btree_iter_node(iter, l))
376 if (!bch2_btree_node_upgrade(iter, l)) {
377 iter->locks_want = l;
382 } while (l < iter->locks_want);
387 void __bch2_btree_iter_downgrade(struct btree_iter *iter,
388 unsigned downgrade_to)
390 unsigned l, new_locks_want = downgrade_to ?:
391 (iter->flags & BTREE_ITER_INTENT ? 1 : 0);
393 if (iter->locks_want < downgrade_to) {
394 iter->locks_want = new_locks_want;
396 while (iter->nodes_locked &&
397 (l = __fls(iter->nodes_locked)) >= iter->locks_want) {
398 if (l > iter->level) {
399 btree_node_unlock(iter, l);
401 if (btree_node_intent_locked(iter, l)) {
402 six_lock_downgrade(&iter->l[l].b->c.lock);
403 iter->nodes_intent_locked ^= 1 << l;
410 bch2_btree_trans_verify_locks(iter->trans);
413 void bch2_trans_downgrade(struct btree_trans *trans)
415 struct btree_iter *iter;
417 trans_for_each_iter(trans, iter)
418 bch2_btree_iter_downgrade(iter);
421 /* Btree transaction locking: */
423 bool bch2_trans_relock(struct btree_trans *trans)
425 struct btree_iter *iter;
428 trans_for_each_iter(trans, iter)
429 if (iter->uptodate == BTREE_ITER_NEED_RELOCK)
430 ret &= bch2_btree_iter_relock(iter, true);
435 void bch2_trans_unlock(struct btree_trans *trans)
437 struct btree_iter *iter;
439 trans_for_each_iter(trans, iter)
440 __bch2_btree_iter_unlock(iter);
443 /* Btree iterator: */
445 #ifdef CONFIG_BCACHEFS_DEBUG
447 static void bch2_btree_iter_verify_cached(struct btree_iter *iter)
449 struct bkey_cached *ck;
450 bool locked = btree_node_locked(iter, 0);
452 if (!bch2_btree_node_relock(iter, 0))
455 ck = (void *) iter->l[0].b;
456 BUG_ON(ck->key.btree_id != iter->btree_id ||
457 bkey_cmp(ck->key.pos, iter->pos));
460 btree_node_unlock(iter, 0);
463 static void bch2_btree_iter_verify_level(struct btree_iter *iter,
466 struct bpos pos = btree_iter_search_key(iter);
467 struct btree_iter_level *l = &iter->l[level];
468 struct btree_node_iter tmp = l->iter;
469 bool locked = btree_node_locked(iter, level);
470 struct bkey_packed *p, *k;
471 char buf1[100], buf2[100];
474 if (!debug_check_iterators(iter->trans->c))
477 if (btree_iter_type(iter) == BTREE_ITER_CACHED) {
479 bch2_btree_iter_verify_cached(iter);
483 BUG_ON(iter->level < iter->min_depth);
485 if (!btree_iter_node(iter, level))
488 if (!bch2_btree_node_relock(iter, level))
492 * Ideally this invariant would always be true, and hopefully in the
493 * future it will be, but for now set_pos_same_leaf() breaks it:
495 BUG_ON(iter->uptodate < BTREE_ITER_NEED_TRAVERSE &&
496 !btree_iter_pos_in_node(iter, l->b));
499 * node iterators don't use leaf node iterator:
501 if (btree_iter_type(iter) == BTREE_ITER_NODES &&
502 level <= iter->min_depth)
505 bch2_btree_node_iter_verify(&l->iter, l->b);
508 * For interior nodes, the iterator will have skipped past
511 * For extents, the iterator may have skipped past deleted keys (but not
514 p = level || btree_node_type_is_extents(iter->btree_id)
515 ? bch2_btree_node_iter_prev_filter(&tmp, l->b, KEY_TYPE_discard)
516 : bch2_btree_node_iter_prev_all(&tmp, l->b);
517 k = bch2_btree_node_iter_peek_all(&l->iter, l->b);
519 if (p && bkey_iter_pos_cmp(l->b, p, &pos) >= 0) {
524 if (k && bkey_iter_pos_cmp(l->b, k, &pos) < 0) {
530 btree_node_unlock(iter, level);
533 strcpy(buf1, "(none)");
534 strcpy(buf2, "(none)");
537 struct bkey uk = bkey_unpack_key(l->b, p);
538 bch2_bkey_to_text(&PBUF(buf1), &uk);
542 struct bkey uk = bkey_unpack_key(l->b, k);
543 bch2_bkey_to_text(&PBUF(buf2), &uk);
546 panic("iterator should be %s key at level %u:\n"
547 "iter pos %s %llu:%llu\n"
551 iter->flags & BTREE_ITER_IS_EXTENTS ? ">" : "=>",
552 iter->pos.inode, iter->pos.offset,
556 static void bch2_btree_iter_verify(struct btree_iter *iter)
560 bch2_btree_trans_verify_locks(iter->trans);
562 for (i = 0; i < BTREE_MAX_DEPTH; i++)
563 bch2_btree_iter_verify_level(iter, i);
566 void bch2_btree_trans_verify_iters(struct btree_trans *trans, struct btree *b)
568 struct btree_iter *iter;
570 if (!debug_check_iterators(trans->c))
573 trans_for_each_iter_with_node(trans, b, iter)
574 bch2_btree_iter_verify_level(iter, b->c.level);
579 static inline void bch2_btree_iter_verify_level(struct btree_iter *iter, unsigned l) {}
580 static inline void bch2_btree_iter_verify(struct btree_iter *iter) {}
584 static void btree_node_iter_set_set_pos(struct btree_node_iter *iter,
587 struct bkey_packed *k)
589 struct btree_node_iter_set *set;
591 btree_node_iter_for_each(iter, set)
592 if (set->end == t->end_offset) {
593 set->k = __btree_node_key_to_offset(b, k);
594 bch2_btree_node_iter_sort(iter, b);
598 bch2_btree_node_iter_push(iter, b, k, btree_bkey_last(b, t));
601 static void __bch2_btree_iter_fix_key_modified(struct btree_iter *iter,
603 struct bkey_packed *where)
605 struct btree_iter_level *l = &iter->l[b->c.level];
606 struct bpos pos = btree_iter_search_key(iter);
608 if (where != bch2_btree_node_iter_peek_all(&l->iter, l->b))
611 if (bkey_iter_pos_cmp(l->b, where, &pos) < 0)
612 bch2_btree_node_iter_advance(&l->iter, l->b);
614 btree_iter_set_dirty(iter, BTREE_ITER_NEED_PEEK);
617 void bch2_btree_iter_fix_key_modified(struct btree_iter *iter,
619 struct bkey_packed *where)
621 struct btree_iter *linked;
623 trans_for_each_iter_with_node(iter->trans, b, linked) {
624 __bch2_btree_iter_fix_key_modified(linked, b, where);
625 bch2_btree_iter_verify_level(linked, b->c.level);
629 static void __bch2_btree_node_iter_fix(struct btree_iter *iter,
631 struct btree_node_iter *node_iter,
633 struct bkey_packed *where,
634 unsigned clobber_u64s,
637 const struct bkey_packed *end = btree_bkey_last(b, t);
638 struct btree_node_iter_set *set;
639 unsigned offset = __btree_node_key_to_offset(b, where);
640 int shift = new_u64s - clobber_u64s;
641 unsigned old_end = t->end_offset - shift;
642 unsigned orig_iter_pos = node_iter->data[0].k;
643 bool iter_current_key_modified =
644 orig_iter_pos >= offset &&
645 orig_iter_pos <= offset + clobber_u64s;
646 struct bpos iter_pos = btree_iter_search_key(iter);
648 btree_node_iter_for_each(node_iter, set)
649 if (set->end == old_end)
652 /* didn't find the bset in the iterator - might have to readd it: */
654 bkey_iter_pos_cmp(b, where, &iter_pos) >= 0) {
655 bch2_btree_node_iter_push(node_iter, b, where, end);
658 /* Iterator is after key that changed */
662 set->end = t->end_offset;
664 /* Iterator hasn't gotten to the key that changed yet: */
669 bkey_iter_pos_cmp(b, where, &iter_pos) >= 0) {
671 } else if (set->k < offset + clobber_u64s) {
672 set->k = offset + new_u64s;
673 if (set->k == set->end)
674 bch2_btree_node_iter_set_drop(node_iter, set);
676 /* Iterator is after key that changed */
677 set->k = (int) set->k + shift;
681 bch2_btree_node_iter_sort(node_iter, b);
683 if (node_iter->data[0].k != orig_iter_pos)
684 iter_current_key_modified = true;
687 * When a new key is added, and the node iterator now points to that
688 * key, the iterator might have skipped past deleted keys that should
689 * come after the key the iterator now points to. We have to rewind to
690 * before those deleted keys - otherwise
691 * bch2_btree_node_iter_prev_all() breaks:
693 if (!bch2_btree_node_iter_end(node_iter) &&
694 iter_current_key_modified &&
696 btree_node_type_is_extents(iter->btree_id))) {
698 struct bkey_packed *k, *k2, *p;
700 k = bch2_btree_node_iter_peek_all(node_iter, b);
702 for_each_bset(b, t) {
703 bool set_pos = false;
705 if (node_iter->data[0].end == t->end_offset)
708 k2 = bch2_btree_node_iter_bset_pos(node_iter, b, t);
710 while ((p = bch2_bkey_prev_all(b, t, k2)) &&
711 bkey_iter_cmp(b, k, p) < 0) {
717 btree_node_iter_set_set_pos(node_iter,
723 node_iter == &iter->l[0].iter &&
724 iter_current_key_modified)
725 btree_iter_set_dirty(iter, BTREE_ITER_NEED_PEEK);
728 void bch2_btree_node_iter_fix(struct btree_iter *iter,
730 struct btree_node_iter *node_iter,
731 struct bkey_packed *where,
732 unsigned clobber_u64s,
735 struct bset_tree *t = bch2_bkey_to_bset(b, where);
736 struct btree_iter *linked;
738 if (node_iter != &iter->l[b->c.level].iter) {
739 __bch2_btree_node_iter_fix(iter, b, node_iter, t,
740 where, clobber_u64s, new_u64s);
742 if (debug_check_iterators(iter->trans->c))
743 bch2_btree_node_iter_verify(node_iter, b);
746 trans_for_each_iter_with_node(iter->trans, b, linked) {
747 __bch2_btree_node_iter_fix(linked, b,
748 &linked->l[b->c.level].iter, t,
749 where, clobber_u64s, new_u64s);
750 bch2_btree_iter_verify_level(linked, b->c.level);
754 static inline struct bkey_s_c __btree_iter_unpack(struct btree_iter *iter,
755 struct btree_iter_level *l,
757 struct bkey_packed *k)
763 * signal to bch2_btree_iter_peek_slot() that we're currently at
766 u->type = KEY_TYPE_deleted;
767 return bkey_s_c_null;
770 ret = bkey_disassemble(l->b, k, u);
772 if (debug_check_bkeys(iter->trans->c))
773 bch2_bkey_debugcheck(iter->trans->c, l->b, ret);
778 /* peek_all() doesn't skip deleted keys */
779 static inline struct bkey_s_c __btree_iter_peek_all(struct btree_iter *iter,
780 struct btree_iter_level *l,
783 return __btree_iter_unpack(iter, l, u,
784 bch2_btree_node_iter_peek_all(&l->iter, l->b));
787 static inline struct bkey_s_c __btree_iter_peek(struct btree_iter *iter,
788 struct btree_iter_level *l)
790 return __btree_iter_unpack(iter, l, &iter->k,
791 bch2_btree_node_iter_peek(&l->iter, l->b));
794 static inline struct bkey_s_c __btree_iter_prev(struct btree_iter *iter,
795 struct btree_iter_level *l)
797 return __btree_iter_unpack(iter, l, &iter->k,
798 bch2_btree_node_iter_prev(&l->iter, l->b));
801 static inline bool btree_iter_advance_to_pos(struct btree_iter *iter,
802 struct btree_iter_level *l,
805 struct bpos pos = btree_iter_search_key(iter);
806 struct bkey_packed *k;
809 while ((k = bch2_btree_node_iter_peek_all(&l->iter, l->b)) &&
810 bkey_iter_pos_cmp(l->b, k, &pos) < 0) {
811 if (max_advance > 0 && nr_advanced >= max_advance)
814 bch2_btree_node_iter_advance(&l->iter, l->b);
822 * Verify that iterator for parent node points to child node:
824 static void btree_iter_verify_new_node(struct btree_iter *iter, struct btree *b)
826 struct btree_iter_level *l;
829 struct bkey_packed *k;
831 if (!IS_ENABLED(CONFIG_BCACHEFS_DEBUG))
834 plevel = b->c.level + 1;
835 if (!btree_iter_node(iter, plevel))
838 parent_locked = btree_node_locked(iter, plevel);
840 if (!bch2_btree_node_relock(iter, plevel))
843 l = &iter->l[plevel];
844 k = bch2_btree_node_iter_peek_all(&l->iter, l->b);
847 bkey_cmp_left_packed(l->b, k, &b->key.k.p)) {
849 struct bkey uk = bkey_unpack_key(b, k);
851 bch2_bkey_to_text(&PBUF(buf), &uk);
852 panic("parent iter doesn't point to new node:\n%s\n%llu:%llu\n",
853 buf, b->key.k.p.inode, b->key.k.p.offset);
857 btree_node_unlock(iter, b->c.level + 1);
860 static inline void __btree_iter_init(struct btree_iter *iter,
863 struct bpos pos = btree_iter_search_key(iter);
864 struct btree_iter_level *l = &iter->l[level];
866 bch2_btree_node_iter_init(&l->iter, l->b, &pos);
868 btree_iter_set_dirty(iter, BTREE_ITER_NEED_PEEK);
871 static inline void btree_iter_node_set(struct btree_iter *iter,
874 BUG_ON(btree_iter_type(iter) == BTREE_ITER_CACHED);
876 btree_iter_verify_new_node(iter, b);
878 EBUG_ON(!btree_iter_pos_in_node(iter, b));
879 EBUG_ON(b->c.lock.state.seq & 1);
881 iter->l[b->c.level].lock_seq = b->c.lock.state.seq;
882 iter->l[b->c.level].b = b;
883 __btree_iter_init(iter, b->c.level);
887 * A btree node is being replaced - update the iterator to point to the new
890 void bch2_btree_iter_node_replace(struct btree_iter *iter, struct btree *b)
892 enum btree_node_locked_type t;
893 struct btree_iter *linked;
895 trans_for_each_iter(iter->trans, linked)
896 if (btree_iter_type(linked) != BTREE_ITER_CACHED &&
897 btree_iter_pos_in_node(linked, b)) {
899 * bch2_btree_iter_node_drop() has already been called -
900 * the old node we're replacing has already been
901 * unlocked and the pointer invalidated
903 BUG_ON(btree_node_locked(linked, b->c.level));
905 t = btree_lock_want(linked, b->c.level);
906 if (t != BTREE_NODE_UNLOCKED) {
907 six_lock_increment(&b->c.lock, t);
908 mark_btree_node_locked(linked, b->c.level, t);
911 btree_iter_node_set(linked, b);
915 void bch2_btree_iter_node_drop(struct btree_iter *iter, struct btree *b)
917 struct btree_iter *linked;
918 unsigned level = b->c.level;
920 trans_for_each_iter(iter->trans, linked)
921 if (linked->l[level].b == b) {
922 __btree_node_unlock(linked, level);
923 linked->l[level].b = BTREE_ITER_NO_NODE_DROP;
928 * A btree node has been modified in such a way as to invalidate iterators - fix
931 void bch2_btree_iter_reinit_node(struct btree_iter *iter, struct btree *b)
933 struct btree_iter *linked;
935 trans_for_each_iter_with_node(iter->trans, b, linked)
936 __btree_iter_init(linked, b->c.level);
939 static int lock_root_check_fn(struct six_lock *lock, void *p)
941 struct btree *b = container_of(lock, struct btree, c.lock);
942 struct btree **rootp = p;
944 return b == *rootp ? 0 : -1;
947 static inline int btree_iter_lock_root(struct btree_iter *iter,
950 struct bch_fs *c = iter->trans->c;
951 struct btree *b, **rootp = &c->btree_roots[iter->btree_id].b;
952 enum six_lock_type lock_type;
955 EBUG_ON(iter->nodes_locked);
958 b = READ_ONCE(*rootp);
959 iter->level = READ_ONCE(b->c.level);
961 if (unlikely(iter->level < depth_want)) {
963 * the root is at a lower depth than the depth we want:
964 * got to the end of the btree, or we're walking nodes
965 * greater than some depth and there are no nodes >=
968 iter->level = depth_want;
969 for (i = iter->level; i < BTREE_MAX_DEPTH; i++)
974 lock_type = __btree_lock_want(iter, iter->level);
975 if (unlikely(!btree_node_lock(b, POS_MAX, iter->level,
977 lock_root_check_fn, rootp)))
980 if (likely(b == READ_ONCE(*rootp) &&
981 b->c.level == iter->level &&
983 for (i = 0; i < iter->level; i++)
984 iter->l[i].b = BTREE_ITER_NO_NODE_LOCK_ROOT;
985 iter->l[iter->level].b = b;
986 for (i = iter->level + 1; i < BTREE_MAX_DEPTH; i++)
989 mark_btree_node_locked(iter, iter->level, lock_type);
990 btree_iter_node_set(iter, b);
994 six_unlock_type(&b->c.lock, lock_type);
999 static void btree_iter_prefetch(struct btree_iter *iter)
1001 struct bch_fs *c = iter->trans->c;
1002 struct btree_iter_level *l = &iter->l[iter->level];
1003 struct btree_node_iter node_iter = l->iter;
1004 struct bkey_packed *k;
1006 unsigned nr = test_bit(BCH_FS_STARTED, &c->flags)
1007 ? (iter->level > 1 ? 0 : 2)
1008 : (iter->level > 1 ? 1 : 16);
1009 bool was_locked = btree_node_locked(iter, iter->level);
1012 if (!bch2_btree_node_relock(iter, iter->level))
1015 bch2_btree_node_iter_advance(&node_iter, l->b);
1016 k = bch2_btree_node_iter_peek(&node_iter, l->b);
1020 bch2_bkey_unpack(l->b, &tmp.k, k);
1021 bch2_btree_node_prefetch(c, iter, &tmp.k, iter->level - 1);
1025 btree_node_unlock(iter, iter->level);
1028 static noinline void btree_node_mem_ptr_set(struct btree_iter *iter,
1029 unsigned plevel, struct btree *b)
1031 struct btree_iter_level *l = &iter->l[plevel];
1032 bool locked = btree_node_locked(iter, plevel);
1033 struct bkey_packed *k;
1034 struct bch_btree_ptr_v2 *bp;
1036 if (!bch2_btree_node_relock(iter, plevel))
1039 k = bch2_btree_node_iter_peek_all(&l->iter, l->b);
1040 BUG_ON(k->type != KEY_TYPE_btree_ptr_v2);
1042 bp = (void *) bkeyp_val(&l->b->format, k);
1043 bp->mem_ptr = (unsigned long)b;
1046 btree_node_unlock(iter, plevel);
1049 static __always_inline int btree_iter_down(struct btree_iter *iter)
1051 struct bch_fs *c = iter->trans->c;
1052 struct btree_iter_level *l = &iter->l[iter->level];
1054 unsigned level = iter->level - 1;
1055 enum six_lock_type lock_type = __btree_lock_want(iter, level);
1058 EBUG_ON(!btree_node_locked(iter, iter->level));
1060 bch2_bkey_unpack(l->b, &tmp.k,
1061 bch2_btree_node_iter_peek(&l->iter, l->b));
1063 b = bch2_btree_node_get(c, iter, &tmp.k, level, lock_type);
1064 if (unlikely(IS_ERR(b)))
1067 mark_btree_node_locked(iter, level, lock_type);
1068 btree_iter_node_set(iter, b);
1070 if (tmp.k.k.type == KEY_TYPE_btree_ptr_v2 &&
1071 unlikely(b != btree_node_mem_ptr(&tmp.k)))
1072 btree_node_mem_ptr_set(iter, level + 1, b);
1074 if (iter->flags & BTREE_ITER_PREFETCH)
1075 btree_iter_prefetch(iter);
1077 iter->level = level;
1082 static void btree_iter_up(struct btree_iter *iter)
1084 btree_node_unlock(iter, iter->level++);
1087 static int btree_iter_traverse_one(struct btree_iter *);
1089 static int __btree_iter_traverse_all(struct btree_trans *trans, int ret)
1091 struct bch_fs *c = trans->c;
1092 struct btree_iter *iter;
1093 u8 sorted[BTREE_ITER_MAX];
1094 unsigned i, nr_sorted = 0;
1096 if (trans->in_traverse_all)
1099 trans->in_traverse_all = true;
1103 trans_for_each_iter(trans, iter)
1104 sorted[nr_sorted++] = iter->idx;
1106 #define btree_iter_cmp_by_idx(_l, _r) \
1107 btree_iter_cmp(&trans->iters[_l], &trans->iters[_r])
1109 bubble_sort(sorted, nr_sorted, btree_iter_cmp_by_idx);
1110 #undef btree_iter_cmp_by_idx
1111 bch2_trans_unlock(trans);
1113 if (unlikely(ret == -ENOMEM)) {
1116 closure_init_stack(&cl);
1119 ret = bch2_btree_cache_cannibalize_lock(c, &cl);
1124 if (unlikely(ret == -EIO)) {
1125 trans->error = true;
1129 BUG_ON(ret && ret != -EINTR);
1131 /* Now, redo traversals in correct order: */
1132 for (i = 0; i < nr_sorted; i++) {
1133 unsigned idx = sorted[i];
1136 * sucessfully traversing one iterator can cause another to be
1137 * unlinked, in btree_key_cache_fill()
1139 if (!(trans->iters_linked & (1ULL << idx)))
1142 ret = btree_iter_traverse_one(&trans->iters[idx]);
1147 if (hweight64(trans->iters_live) > 1)
1150 trans_for_each_iter(trans, iter)
1151 if (iter->flags & BTREE_ITER_KEEP_UNTIL_COMMIT) {
1156 bch2_btree_cache_cannibalize_unlock(c);
1158 trans->in_traverse_all = false;
1162 int bch2_btree_iter_traverse_all(struct btree_trans *trans)
1164 return __btree_iter_traverse_all(trans, 0);
1167 static inline bool btree_iter_good_node(struct btree_iter *iter,
1168 unsigned l, int check_pos)
1170 if (!is_btree_node(iter, l) ||
1171 !bch2_btree_node_relock(iter, l))
1174 if (check_pos <= 0 && btree_iter_pos_before_node(iter, iter->l[l].b))
1176 if (check_pos >= 0 && btree_iter_pos_after_node(iter, iter->l[l].b))
1181 static inline unsigned btree_iter_up_until_good_node(struct btree_iter *iter,
1184 unsigned l = iter->level;
1186 while (btree_iter_node(iter, l) &&
1187 !btree_iter_good_node(iter, l, check_pos)) {
1188 btree_node_unlock(iter, l);
1189 iter->l[l].b = BTREE_ITER_NO_NODE_UP;
1197 * This is the main state machine for walking down the btree - walks down to a
1200 * Returns 0 on success, -EIO on error (error reading in a btree node).
1202 * On error, caller (peek_node()/peek_key()) must return NULL; the error is
1203 * stashed in the iterator and returned from bch2_trans_exit().
1205 static int btree_iter_traverse_one(struct btree_iter *iter)
1207 unsigned depth_want = iter->level;
1210 * if we need interior nodes locked, call btree_iter_relock() to make
1211 * sure we walk back up enough that we lock them:
1213 if (iter->uptodate == BTREE_ITER_NEED_RELOCK ||
1214 iter->locks_want > 1)
1215 bch2_btree_iter_relock(iter, false);
1217 if (btree_iter_type(iter) == BTREE_ITER_CACHED)
1218 return bch2_btree_iter_traverse_cached(iter);
1220 if (iter->uptodate < BTREE_ITER_NEED_RELOCK)
1223 if (unlikely(iter->level >= BTREE_MAX_DEPTH))
1227 * XXX: correctly using BTREE_ITER_UPTODATE should make using check_pos
1230 iter->level = btree_iter_up_until_good_node(iter, 0);
1233 * If we've got a btree node locked (i.e. we aren't about to relock the
1234 * root) - advance its node iterator if necessary:
1236 * XXX correctly using BTREE_ITER_UPTODATE should make this unnecessary
1238 if (is_btree_node(iter, iter->level)) {
1239 BUG_ON(!btree_iter_pos_in_node(iter, iter->l[iter->level].b));
1241 btree_iter_advance_to_pos(iter, &iter->l[iter->level], -1);
1245 * Note: iter->nodes[iter->level] may be temporarily NULL here - that
1246 * would indicate to other code that we got to the end of the btree,
1247 * here it indicates that relocking the root failed - it's critical that
1248 * btree_iter_lock_root() comes next and that it can't fail
1250 while (iter->level > depth_want) {
1251 int ret = btree_iter_node(iter, iter->level)
1252 ? btree_iter_down(iter)
1253 : btree_iter_lock_root(iter, depth_want);
1254 if (unlikely(ret)) {
1258 iter->level = depth_want;
1261 iter->flags |= BTREE_ITER_ERROR;
1262 iter->l[iter->level].b =
1263 BTREE_ITER_NO_NODE_ERROR;
1265 iter->l[iter->level].b =
1266 BTREE_ITER_NO_NODE_DOWN;
1272 iter->uptodate = BTREE_ITER_NEED_PEEK;
1274 bch2_btree_iter_verify(iter);
1278 int __must_check __bch2_btree_iter_traverse(struct btree_iter *iter)
1280 struct btree_trans *trans = iter->trans;
1283 ret = bch2_trans_cond_resched(trans) ?:
1284 btree_iter_traverse_one(iter);
1286 ret = __btree_iter_traverse_all(trans, ret);
1291 static inline void bch2_btree_iter_checks(struct btree_iter *iter)
1293 enum btree_iter_type type = btree_iter_type(iter);
1295 EBUG_ON(iter->btree_id >= BTREE_ID_NR);
1297 BUG_ON((type == BTREE_ITER_KEYS ||
1298 type == BTREE_ITER_CACHED) &&
1299 (bkey_cmp(iter->pos, bkey_start_pos(&iter->k)) < 0 ||
1300 bkey_cmp(iter->pos, iter->k.p) > 0));
1302 bch2_btree_iter_verify_locks(iter);
1303 bch2_btree_iter_verify_level(iter, iter->level);
1306 /* Iterate across nodes (leaf and interior nodes) */
1308 struct btree *bch2_btree_iter_peek_node(struct btree_iter *iter)
1313 EBUG_ON(btree_iter_type(iter) != BTREE_ITER_NODES);
1314 bch2_btree_iter_checks(iter);
1316 if (iter->uptodate == BTREE_ITER_UPTODATE)
1317 return iter->l[iter->level].b;
1319 ret = bch2_btree_iter_traverse(iter);
1323 b = btree_iter_node(iter, iter->level);
1327 BUG_ON(bkey_cmp(b->key.k.p, iter->pos) < 0);
1329 iter->pos = b->key.k.p;
1330 iter->uptodate = BTREE_ITER_UPTODATE;
1332 bch2_btree_iter_verify(iter);
1337 struct btree *bch2_btree_iter_next_node(struct btree_iter *iter)
1342 EBUG_ON(btree_iter_type(iter) != BTREE_ITER_NODES);
1343 bch2_btree_iter_checks(iter);
1345 /* already got to end? */
1346 if (!btree_iter_node(iter, iter->level))
1349 bch2_trans_cond_resched(iter->trans);
1351 btree_iter_up(iter);
1353 if (!bch2_btree_node_relock(iter, iter->level))
1354 btree_iter_set_dirty(iter, BTREE_ITER_NEED_RELOCK);
1356 ret = bch2_btree_iter_traverse(iter);
1361 b = btree_iter_node(iter, iter->level);
1365 if (bkey_cmp(iter->pos, b->key.k.p) < 0) {
1367 * Haven't gotten to the end of the parent node: go back down to
1368 * the next child node
1372 * We don't really want to be unlocking here except we can't
1373 * directly tell btree_iter_traverse() "traverse to this level"
1374 * except by setting iter->level, so we have to unlock so we
1375 * don't screw up our lock invariants:
1377 if (btree_node_read_locked(iter, iter->level))
1378 btree_node_unlock(iter, iter->level);
1380 iter->pos = bkey_successor(iter->pos);
1381 iter->level = iter->min_depth;
1383 btree_iter_set_dirty(iter, BTREE_ITER_NEED_TRAVERSE);
1384 ret = bch2_btree_iter_traverse(iter);
1388 b = iter->l[iter->level].b;
1391 iter->pos = b->key.k.p;
1392 iter->uptodate = BTREE_ITER_UPTODATE;
1394 bch2_btree_iter_verify(iter);
1399 /* Iterate across keys (in leaf nodes only) */
1401 void bch2_btree_iter_set_pos_same_leaf(struct btree_iter *iter, struct bpos new_pos)
1403 struct btree_iter_level *l = &iter->l[0];
1405 EBUG_ON(iter->level != 0);
1406 EBUG_ON(bkey_cmp(new_pos, iter->pos) < 0);
1407 EBUG_ON(!btree_node_locked(iter, 0));
1408 EBUG_ON(bkey_cmp(new_pos, l->b->key.k.p) > 0);
1410 bkey_init(&iter->k);
1411 iter->k.p = iter->pos = new_pos;
1412 btree_iter_set_dirty(iter, BTREE_ITER_NEED_PEEK);
1414 btree_iter_advance_to_pos(iter, l, -1);
1418 * keeping a node locked that's outside (even just outside) iter->pos
1419 * breaks __bch2_btree_node_lock(). This seems to only affect
1420 * bch2_btree_node_get_sibling so for now it's fixed there, but we
1421 * should try to get rid of this corner case.
1423 * (this behaviour is currently needed for BTREE_INSERT_NOUNLOCK)
1426 if (bch2_btree_node_iter_end(&l->iter) &&
1427 btree_iter_pos_after_node(iter, l->b))
1428 btree_iter_set_dirty(iter, BTREE_ITER_NEED_TRAVERSE);
1431 static void btree_iter_pos_changed(struct btree_iter *iter, int cmp)
1433 unsigned l = iter->level;
1438 if (unlikely(btree_iter_type(iter) == BTREE_ITER_CACHED)) {
1439 btree_node_unlock(iter, 0);
1440 iter->l[0].b = BTREE_ITER_NO_NODE_UP;
1441 btree_iter_set_dirty(iter, BTREE_ITER_NEED_TRAVERSE);
1445 l = btree_iter_up_until_good_node(iter, cmp);
1447 if (btree_iter_node(iter, l)) {
1449 * We might have to skip over many keys, or just a few: try
1450 * advancing the node iterator, and if we have to skip over too
1451 * many keys just reinit it (or if we're rewinding, since that
1455 !btree_iter_advance_to_pos(iter, &iter->l[l], 8))
1456 __btree_iter_init(iter, l);
1458 /* Don't leave it locked if we're not supposed to: */
1459 if (btree_lock_want(iter, l) == BTREE_NODE_UNLOCKED)
1460 btree_node_unlock(iter, l);
1463 if (l != iter->level)
1464 btree_iter_set_dirty(iter, BTREE_ITER_NEED_TRAVERSE);
1466 btree_iter_set_dirty(iter, BTREE_ITER_NEED_PEEK);
1469 void __bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos,
1470 bool strictly_greater)
1472 struct bpos old = btree_iter_search_key(iter);
1475 iter->flags &= ~BTREE_ITER_IS_EXTENTS;
1476 iter->flags |= strictly_greater ? BTREE_ITER_IS_EXTENTS : 0;
1478 bkey_init(&iter->k);
1479 iter->k.p = iter->pos = new_pos;
1481 cmp = bkey_cmp(btree_iter_search_key(iter), old);
1483 btree_iter_pos_changed(iter, cmp);
1486 void bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos)
1488 int cmp = bkey_cmp(new_pos, iter->pos);
1490 bkey_init(&iter->k);
1491 iter->k.p = iter->pos = new_pos;
1493 btree_iter_pos_changed(iter, cmp);
1496 static inline bool btree_iter_set_pos_to_next_leaf(struct btree_iter *iter)
1498 struct btree_iter_level *l = &iter->l[0];
1501 bkey_init(&iter->k);
1502 iter->k.p = iter->pos = l->b->key.k.p;
1504 ret = bkey_cmp(iter->pos, POS_MAX) != 0;
1505 if (ret && !(iter->flags & BTREE_ITER_IS_EXTENTS))
1506 iter->k.p = iter->pos = bkey_successor(iter->pos);
1508 btree_iter_pos_changed(iter, 1);
1512 static inline bool btree_iter_set_pos_to_prev_leaf(struct btree_iter *iter)
1514 struct btree_iter_level *l = &iter->l[0];
1517 bkey_init(&iter->k);
1518 iter->k.p = iter->pos = l->b->data->min_key;
1519 iter->uptodate = BTREE_ITER_NEED_TRAVERSE;
1521 ret = bkey_cmp(iter->pos, POS_MIN) != 0;
1523 iter->k.p = iter->pos = bkey_predecessor(iter->pos);
1525 if (iter->flags & BTREE_ITER_IS_EXTENTS)
1526 iter->k.p = iter->pos = bkey_predecessor(iter->pos);
1529 btree_iter_pos_changed(iter, -1);
1534 * btree_iter_peek_uptodate - given an iterator that is uptodate, return the key
1535 * it currently points to
1537 static inline struct bkey_s_c btree_iter_peek_uptodate(struct btree_iter *iter)
1539 struct btree_iter_level *l = &iter->l[0];
1540 struct bkey_s_c ret = { .k = &iter->k };
1542 if (!bkey_deleted(&iter->k)) {
1543 struct bkey_packed *_k =
1544 __bch2_btree_node_iter_peek_all(&l->iter, l->b);
1546 ret.v = bkeyp_val(&l->b->format, _k);
1548 if (debug_check_iterators(iter->trans->c)) {
1549 struct bkey k = bkey_unpack_key(l->b, _k);
1551 BUG_ON(memcmp(&k, &iter->k, sizeof(k)));
1554 if (debug_check_bkeys(iter->trans->c))
1555 bch2_bkey_debugcheck(iter->trans->c, l->b, ret);
1562 * bch2_btree_iter_peek: returns first key greater than or equal to iterator's
1565 struct bkey_s_c bch2_btree_iter_peek(struct btree_iter *iter)
1567 struct btree_iter_level *l = &iter->l[0];
1571 EBUG_ON(btree_iter_type(iter) != BTREE_ITER_KEYS);
1572 bch2_btree_iter_checks(iter);
1574 if (iter->uptodate == BTREE_ITER_UPTODATE &&
1575 !bkey_deleted(&iter->k))
1576 return btree_iter_peek_uptodate(iter);
1579 ret = bch2_btree_iter_traverse(iter);
1581 return bkey_s_c_err(ret);
1583 k = __btree_iter_peek(iter, l);
1587 if (!btree_iter_set_pos_to_next_leaf(iter))
1588 return bkey_s_c_null;
1592 * iter->pos should always be equal to the key we just
1593 * returned - except extents can straddle iter->pos:
1595 if (!(iter->flags & BTREE_ITER_IS_EXTENTS) ||
1596 bkey_cmp(bkey_start_pos(k.k), iter->pos) > 0)
1597 iter->pos = bkey_start_pos(k.k);
1599 iter->uptodate = BTREE_ITER_UPTODATE;
1601 bch2_btree_iter_verify_level(iter, 0);
1606 * bch2_btree_iter_next: returns first key greater than iterator's current
1609 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *iter)
1611 if (unlikely(!bkey_cmp(iter->k.p, POS_MAX)))
1612 return bkey_s_c_null;
1614 bch2_btree_iter_set_pos(iter,
1615 (iter->flags & BTREE_ITER_IS_EXTENTS)
1617 : bkey_successor(iter->k.p));
1619 return bch2_btree_iter_peek(iter);
1622 static struct bkey_s_c __btree_trans_updates_peek(struct btree_iter *iter)
1624 struct bpos pos = btree_iter_search_key(iter);
1625 struct btree_trans *trans = iter->trans;
1626 struct btree_insert_entry *i;
1628 trans_for_each_update2(trans, i)
1629 if ((cmp_int(iter->btree_id, i->iter->btree_id) ?:
1630 bkey_cmp(pos, i->k->k.p)) <= 0)
1633 return i < trans->updates2 + trans->nr_updates2 &&
1634 iter->btree_id == i->iter->btree_id
1635 ? bkey_i_to_s_c(i->k)
1639 static struct bkey_s_c __bch2_btree_iter_peek_with_updates(struct btree_iter *iter)
1641 struct btree_iter_level *l = &iter->l[0];
1642 struct bkey_s_c k = __btree_iter_peek(iter, l);
1643 struct bkey_s_c u = __btree_trans_updates_peek(iter);
1645 if (k.k && (!u.k || bkey_cmp(k.k->p, u.k->p) < 0))
1647 if (u.k && bkey_cmp(u.k->p, l->b->key.k.p) <= 0) {
1651 return bkey_s_c_null;
1654 struct bkey_s_c bch2_btree_iter_peek_with_updates(struct btree_iter *iter)
1659 EBUG_ON(btree_iter_type(iter) != BTREE_ITER_KEYS);
1660 bch2_btree_iter_checks(iter);
1663 ret = bch2_btree_iter_traverse(iter);
1665 return bkey_s_c_err(ret);
1667 k = __bch2_btree_iter_peek_with_updates(iter);
1669 if (k.k && bkey_deleted(k.k)) {
1670 bch2_btree_iter_set_pos(iter,
1671 (iter->flags & BTREE_ITER_IS_EXTENTS)
1673 : bkey_successor(iter->k.p));
1680 if (!btree_iter_set_pos_to_next_leaf(iter))
1681 return bkey_s_c_null;
1685 * iter->pos should always be equal to the key we just
1686 * returned - except extents can straddle iter->pos:
1688 if (!(iter->flags & BTREE_ITER_IS_EXTENTS) ||
1689 bkey_cmp(bkey_start_pos(k.k), iter->pos) > 0)
1690 iter->pos = bkey_start_pos(k.k);
1692 iter->uptodate = BTREE_ITER_UPTODATE;
1696 struct bkey_s_c bch2_btree_iter_next_with_updates(struct btree_iter *iter)
1698 if (unlikely(!bkey_cmp(iter->k.p, POS_MAX)))
1699 return bkey_s_c_null;
1701 bch2_btree_iter_set_pos(iter,
1702 (iter->flags & BTREE_ITER_IS_EXTENTS)
1704 : bkey_successor(iter->k.p));
1706 return bch2_btree_iter_peek_with_updates(iter);
1710 * bch2_btree_iter_peek_prev: returns first key less than or equal to
1711 * iterator's current position
1713 struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *iter)
1715 struct bpos pos = iter->pos;
1716 struct btree_iter_level *l = &iter->l[0];
1720 EBUG_ON(btree_iter_type(iter) != BTREE_ITER_KEYS);
1721 bch2_btree_iter_checks(iter);
1723 if (iter->uptodate == BTREE_ITER_UPTODATE &&
1724 !bkey_deleted(&iter->k))
1725 return btree_iter_peek_uptodate(iter);
1728 ret = bch2_btree_iter_traverse(iter);
1730 return bkey_s_c_err(ret);
1732 k = __btree_iter_peek(iter, l);
1733 if (!k.k || bkey_cmp(bkey_start_pos(k.k), pos) > 0)
1734 k = __btree_iter_prev(iter, l);
1739 if (!btree_iter_set_pos_to_prev_leaf(iter))
1740 return bkey_s_c_null;
1743 EBUG_ON(bkey_cmp(bkey_start_pos(k.k), pos) > 0);
1744 iter->pos = bkey_start_pos(k.k);
1745 iter->uptodate = BTREE_ITER_UPTODATE;
1750 * bch2_btree_iter_prev: returns first key less than iterator's current
1753 struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *iter)
1755 struct bpos pos = bkey_start_pos(&iter->k);
1757 EBUG_ON(btree_iter_type(iter) != BTREE_ITER_KEYS);
1758 bch2_btree_iter_checks(iter);
1760 if (unlikely(!bkey_cmp(pos, POS_MIN)))
1761 return bkey_s_c_null;
1763 bch2_btree_iter_set_pos(iter, bkey_predecessor(pos));
1765 return bch2_btree_iter_peek_prev(iter);
1768 static inline struct bkey_s_c
1769 __bch2_btree_iter_peek_slot_extents(struct btree_iter *iter)
1771 struct btree_iter_level *l = &iter->l[0];
1772 struct btree_node_iter node_iter;
1777 /* keys & holes can't span inode numbers: */
1778 if (iter->pos.offset == KEY_OFFSET_MAX) {
1779 if (iter->pos.inode == KEY_INODE_MAX)
1780 return bkey_s_c_null;
1782 bch2_btree_iter_set_pos(iter, bkey_successor(iter->pos));
1784 ret = bch2_btree_iter_traverse(iter);
1786 return bkey_s_c_err(ret);
1790 * iterator is now at the correct position for inserting at iter->pos,
1791 * but we need to keep iterating until we find the first non whiteout so
1792 * we know how big a hole we have, if any:
1795 node_iter = l->iter;
1796 k = __btree_iter_unpack(iter, l, &iter->k,
1797 bch2_btree_node_iter_peek(&node_iter, l->b));
1799 if (k.k && bkey_cmp(bkey_start_pos(k.k), iter->pos) <= 0) {
1801 * We're not setting iter->uptodate because the node iterator
1802 * doesn't necessarily point at the key we're returning:
1805 EBUG_ON(bkey_cmp(k.k->p, iter->pos) <= 0);
1806 bch2_btree_iter_verify_level(iter, 0);
1818 min_t(u64, KEY_SIZE_MAX,
1819 (k.k->p.inode == n.p.inode
1820 ? bkey_start_offset(k.k)
1827 iter->uptodate = BTREE_ITER_UPTODATE;
1829 bch2_btree_iter_verify_level(iter, 0);
1830 return (struct bkey_s_c) { &iter->k, NULL };
1833 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *iter)
1835 struct btree_iter_level *l = &iter->l[0];
1839 EBUG_ON(btree_iter_type(iter) != BTREE_ITER_KEYS);
1840 bch2_btree_iter_checks(iter);
1842 if (iter->uptodate == BTREE_ITER_UPTODATE)
1843 return btree_iter_peek_uptodate(iter);
1845 ret = bch2_btree_iter_traverse(iter);
1847 return bkey_s_c_err(ret);
1849 if (iter->flags & BTREE_ITER_IS_EXTENTS)
1850 return __bch2_btree_iter_peek_slot_extents(iter);
1852 k = __btree_iter_peek_all(iter, l, &iter->k);
1854 EBUG_ON(k.k && bkey_deleted(k.k) && bkey_cmp(k.k->p, iter->pos) == 0);
1856 if (!k.k || bkey_cmp(iter->pos, k.k->p)) {
1858 bkey_init(&iter->k);
1859 iter->k.p = iter->pos;
1860 k = (struct bkey_s_c) { &iter->k, NULL };
1863 iter->uptodate = BTREE_ITER_UPTODATE;
1864 bch2_btree_iter_verify_level(iter, 0);
1868 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *iter)
1870 if (unlikely(!bkey_cmp(iter->k.p, POS_MAX)))
1871 return bkey_s_c_null;
1873 bch2_btree_iter_set_pos(iter,
1874 (iter->flags & BTREE_ITER_IS_EXTENTS)
1876 : bkey_successor(iter->k.p));
1878 return bch2_btree_iter_peek_slot(iter);
1881 struct bkey_s_c bch2_btree_iter_peek_cached(struct btree_iter *iter)
1883 struct bkey_cached *ck;
1886 EBUG_ON(btree_iter_type(iter) != BTREE_ITER_CACHED);
1887 bch2_btree_iter_checks(iter);
1889 ret = bch2_btree_iter_traverse(iter);
1891 return bkey_s_c_err(ret);
1893 ck = (void *) iter->l[0].b;
1895 EBUG_ON(iter->btree_id != ck->key.btree_id ||
1896 bkey_cmp(iter->pos, ck->key.pos));
1899 return bkey_i_to_s_c(ck->k);
1902 static inline void bch2_btree_iter_init(struct btree_trans *trans,
1903 struct btree_iter *iter, enum btree_id btree_id,
1904 struct bpos pos, unsigned flags)
1906 struct bch_fs *c = trans->c;
1909 if (btree_node_type_is_extents(btree_id) &&
1910 !(flags & BTREE_ITER_NODES))
1911 flags |= BTREE_ITER_IS_EXTENTS;
1913 iter->trans = trans;
1915 bkey_init(&iter->k);
1917 iter->flags = flags;
1918 iter->uptodate = BTREE_ITER_NEED_TRAVERSE;
1919 iter->btree_id = btree_id;
1921 iter->min_depth = 0;
1922 iter->locks_want = flags & BTREE_ITER_INTENT ? 1 : 0;
1923 iter->nodes_locked = 0;
1924 iter->nodes_intent_locked = 0;
1925 for (i = 0; i < ARRAY_SIZE(iter->l); i++)
1926 iter->l[i].b = BTREE_ITER_NO_NODE_INIT;
1928 prefetch(c->btree_roots[btree_id].b);
1931 /* new transactional stuff: */
1933 static inline void __bch2_trans_iter_free(struct btree_trans *trans,
1936 __bch2_btree_iter_unlock(&trans->iters[idx]);
1937 trans->iters_linked &= ~(1ULL << idx);
1938 trans->iters_live &= ~(1ULL << idx);
1939 trans->iters_touched &= ~(1ULL << idx);
1942 int bch2_trans_iter_put(struct btree_trans *trans,
1943 struct btree_iter *iter)
1947 if (IS_ERR_OR_NULL(iter))
1950 BUG_ON(trans->iters + iter->idx != iter);
1952 ret = btree_iter_err(iter);
1954 if (!(trans->iters_touched & (1ULL << iter->idx)) &&
1955 !(iter->flags & BTREE_ITER_KEEP_UNTIL_COMMIT))
1956 __bch2_trans_iter_free(trans, iter->idx);
1958 trans->iters_live &= ~(1ULL << iter->idx);
1962 int bch2_trans_iter_free(struct btree_trans *trans,
1963 struct btree_iter *iter)
1965 if (IS_ERR_OR_NULL(iter))
1968 trans->iters_touched &= ~(1ULL << iter->idx);
1970 return bch2_trans_iter_put(trans, iter);
1973 static int bch2_trans_realloc_iters(struct btree_trans *trans,
1976 void *p, *new_iters, *new_updates, *new_updates2;
1978 size_t updates_bytes;
1980 new_size = roundup_pow_of_two(new_size);
1982 BUG_ON(new_size > BTREE_ITER_MAX);
1984 if (new_size <= trans->size)
1987 BUG_ON(trans->used_mempool);
1989 bch2_trans_unlock(trans);
1991 iters_bytes = sizeof(struct btree_iter) * new_size;
1992 updates_bytes = sizeof(struct btree_insert_entry) * new_size;
1994 p = kmalloc(iters_bytes +
1996 updates_bytes, GFP_NOFS);
2000 p = mempool_alloc(&trans->c->btree_iters_pool, GFP_NOFS);
2001 new_size = BTREE_ITER_MAX;
2003 trans->used_mempool = true;
2005 new_iters = p; p += iters_bytes;
2006 new_updates = p; p += updates_bytes;
2007 new_updates2 = p; p += updates_bytes;
2009 memcpy(new_iters, trans->iters,
2010 sizeof(struct btree_iter) * trans->nr_iters);
2011 memcpy(new_updates, trans->updates,
2012 sizeof(struct btree_insert_entry) * trans->nr_updates);
2013 memcpy(new_updates2, trans->updates2,
2014 sizeof(struct btree_insert_entry) * trans->nr_updates2);
2016 if (IS_ENABLED(CONFIG_BCACHEFS_DEBUG))
2017 memset(trans->iters, POISON_FREE,
2018 sizeof(struct btree_iter) * trans->nr_iters +
2019 sizeof(struct btree_insert_entry) * trans->nr_iters);
2021 if (trans->iters != trans->iters_onstack)
2022 kfree(trans->iters);
2024 trans->iters = new_iters;
2025 trans->updates = new_updates;
2026 trans->updates2 = new_updates2;
2027 trans->size = new_size;
2029 if (trans->iters_live) {
2030 trace_trans_restart_iters_realloced(trans->ip, trans->size);
2037 static struct btree_iter *btree_trans_iter_alloc(struct btree_trans *trans)
2039 unsigned idx = __ffs64(~trans->iters_linked);
2041 if (idx < trans->nr_iters)
2044 if (trans->nr_iters == trans->size) {
2047 if (trans->nr_iters >= BTREE_ITER_MAX) {
2048 struct btree_iter *iter;
2050 trans_for_each_iter(trans, iter) {
2051 pr_err("iter: btree %s pos %llu:%llu%s%s%s %ps",
2052 bch2_btree_ids[iter->btree_id],
2055 (trans->iters_live & (1ULL << iter->idx)) ? " live" : "",
2056 (trans->iters_touched & (1ULL << iter->idx)) ? " touched" : "",
2057 iter->flags & BTREE_ITER_KEEP_UNTIL_COMMIT ? " keep" : "",
2058 (void *) iter->ip_allocated);
2061 panic("trans iter oveflow\n");
2064 ret = bch2_trans_realloc_iters(trans, trans->size * 2);
2066 return ERR_PTR(ret);
2069 idx = trans->nr_iters++;
2070 BUG_ON(trans->nr_iters > trans->size);
2072 trans->iters[idx].idx = idx;
2074 BUG_ON(trans->iters_linked & (1ULL << idx));
2075 trans->iters_linked |= 1ULL << idx;
2076 trans->iters[idx].flags = 0;
2077 return &trans->iters[idx];
2080 static inline void btree_iter_copy(struct btree_iter *dst,
2081 struct btree_iter *src)
2083 unsigned i, idx = dst->idx;
2087 dst->flags &= ~BTREE_ITER_KEEP_UNTIL_COMMIT;
2089 for (i = 0; i < BTREE_MAX_DEPTH; i++)
2090 if (btree_node_locked(dst, i))
2091 six_lock_increment(&dst->l[i].b->c.lock,
2092 __btree_lock_want(dst, i));
2094 dst->flags &= ~BTREE_ITER_KEEP_UNTIL_COMMIT;
2095 dst->flags &= ~BTREE_ITER_SET_POS_AFTER_COMMIT;
2098 static inline struct bpos bpos_diff(struct bpos l, struct bpos r)
2100 if (bkey_cmp(l, r) > 0)
2103 return POS(r.inode - l.inode, r.offset - l.offset);
2106 static struct btree_iter *__btree_trans_get_iter(struct btree_trans *trans,
2107 unsigned btree_id, struct bpos pos,
2110 struct btree_iter *iter, *best = NULL;
2112 BUG_ON(trans->nr_iters > BTREE_ITER_MAX);
2114 trans_for_each_iter(trans, iter) {
2115 if (btree_iter_type(iter) != (flags & BTREE_ITER_TYPE))
2118 if (iter->btree_id != btree_id)
2122 bkey_cmp(bpos_diff(best->pos, pos),
2123 bpos_diff(iter->pos, pos)) < 0)
2130 iter = btree_trans_iter_alloc(trans);
2134 bch2_btree_iter_init(trans, iter, btree_id, pos, flags);
2135 } else if ((trans->iters_live & (1ULL << best->idx)) ||
2136 (best->flags & BTREE_ITER_KEEP_UNTIL_COMMIT)) {
2137 iter = btree_trans_iter_alloc(trans);
2141 btree_iter_copy(iter, best);
2146 iter->flags &= ~BTREE_ITER_KEEP_UNTIL_COMMIT;
2147 iter->flags &= ~BTREE_ITER_USER_FLAGS;
2148 iter->flags |= flags & BTREE_ITER_USER_FLAGS;
2150 if (iter->flags & BTREE_ITER_INTENT)
2151 bch2_btree_iter_upgrade(iter, 1);
2153 bch2_btree_iter_downgrade(iter);
2155 BUG_ON(iter->btree_id != btree_id);
2156 BUG_ON((iter->flags ^ flags) & BTREE_ITER_TYPE);
2157 BUG_ON(iter->flags & BTREE_ITER_KEEP_UNTIL_COMMIT);
2158 BUG_ON(iter->flags & BTREE_ITER_SET_POS_AFTER_COMMIT);
2159 BUG_ON(trans->iters_live & (1ULL << iter->idx));
2161 trans->iters_live |= 1ULL << iter->idx;
2162 trans->iters_touched |= 1ULL << iter->idx;
2167 struct btree_iter *__bch2_trans_get_iter(struct btree_trans *trans,
2168 enum btree_id btree_id,
2169 struct bpos pos, unsigned flags)
2171 struct btree_iter *iter =
2172 __btree_trans_get_iter(trans, btree_id, pos, flags);
2175 __bch2_btree_iter_set_pos(iter, pos,
2176 btree_node_type_is_extents(btree_id));
2180 struct btree_iter *bch2_trans_get_node_iter(struct btree_trans *trans,
2181 enum btree_id btree_id,
2183 unsigned locks_want,
2187 struct btree_iter *iter =
2188 __btree_trans_get_iter(trans, btree_id, pos,
2189 flags|BTREE_ITER_NODES);
2192 BUG_ON(IS_ERR(iter));
2193 BUG_ON(bkey_cmp(iter->pos, pos));
2195 iter->locks_want = locks_want;
2196 iter->level = depth;
2197 iter->min_depth = depth;
2199 for (i = 0; i < ARRAY_SIZE(iter->l); i++)
2200 iter->l[i].b = NULL;
2201 iter->l[iter->level].b = BTREE_ITER_NO_NODE_INIT;
2206 struct btree_iter *__bch2_trans_copy_iter(struct btree_trans *trans,
2207 struct btree_iter *src)
2209 struct btree_iter *iter;
2211 iter = btree_trans_iter_alloc(trans);
2215 btree_iter_copy(iter, src);
2217 trans->iters_live |= 1ULL << iter->idx;
2219 * We don't need to preserve this iter since it's cheap to copy it
2220 * again - this will cause trans_iter_put() to free it right away:
2222 trans->iters_touched &= ~(1ULL << iter->idx);
2227 static int bch2_trans_preload_mem(struct btree_trans *trans, size_t size)
2229 if (size > trans->mem_bytes) {
2230 size_t old_bytes = trans->mem_bytes;
2231 size_t new_bytes = roundup_pow_of_two(size);
2232 void *new_mem = krealloc(trans->mem, new_bytes, GFP_NOFS);
2237 trans->mem = new_mem;
2238 trans->mem_bytes = new_bytes;
2241 trace_trans_restart_mem_realloced(trans->ip, new_bytes);
2249 void *bch2_trans_kmalloc(struct btree_trans *trans, size_t size)
2254 ret = bch2_trans_preload_mem(trans, trans->mem_top + size);
2256 return ERR_PTR(ret);
2258 p = trans->mem + trans->mem_top;
2259 trans->mem_top += size;
2263 inline void bch2_trans_unlink_iters(struct btree_trans *trans)
2265 u64 iters = trans->iters_linked &
2266 ~trans->iters_touched &
2270 unsigned idx = __ffs64(iters);
2272 iters &= ~(1ULL << idx);
2273 __bch2_trans_iter_free(trans, idx);
2277 void bch2_trans_reset(struct btree_trans *trans, unsigned flags)
2279 struct btree_iter *iter;
2281 trans_for_each_iter(trans, iter)
2282 iter->flags &= ~(BTREE_ITER_KEEP_UNTIL_COMMIT|
2283 BTREE_ITER_SET_POS_AFTER_COMMIT);
2285 bch2_trans_unlink_iters(trans);
2287 trans->iters_touched &= trans->iters_live;
2289 trans->need_reset = 0;
2290 trans->nr_updates = 0;
2291 trans->nr_updates2 = 0;
2294 trans->extra_journal_entries = NULL;
2295 trans->extra_journal_entry_u64s = 0;
2297 if (trans->fs_usage_deltas) {
2298 trans->fs_usage_deltas->used = 0;
2299 memset(&trans->fs_usage_deltas->memset_start, 0,
2300 (void *) &trans->fs_usage_deltas->memset_end -
2301 (void *) &trans->fs_usage_deltas->memset_start);
2304 if (!(flags & TRANS_RESET_NOTRAVERSE))
2305 bch2_btree_iter_traverse_all(trans);
2308 void bch2_trans_init(struct btree_trans *trans, struct bch_fs *c,
2309 unsigned expected_nr_iters,
2310 size_t expected_mem_bytes)
2312 memset(trans, 0, offsetof(struct btree_trans, iters_onstack));
2315 * reallocating iterators currently completely breaks
2316 * bch2_trans_iter_put():
2318 expected_nr_iters = BTREE_ITER_MAX;
2321 trans->ip = _RET_IP_;
2322 trans->size = ARRAY_SIZE(trans->iters_onstack);
2323 trans->iters = trans->iters_onstack;
2324 trans->updates = trans->updates_onstack;
2325 trans->updates2 = trans->updates2_onstack;
2326 trans->fs_usage_deltas = NULL;
2328 if (expected_nr_iters > trans->size)
2329 bch2_trans_realloc_iters(trans, expected_nr_iters);
2331 if (expected_mem_bytes)
2332 bch2_trans_preload_mem(trans, expected_mem_bytes);
2334 #ifdef CONFIG_BCACHEFS_DEBUG
2335 trans->pid = current->pid;
2336 mutex_lock(&c->btree_trans_lock);
2337 list_add(&trans->list, &c->btree_trans_list);
2338 mutex_unlock(&c->btree_trans_lock);
2342 int bch2_trans_exit(struct btree_trans *trans)
2344 bch2_trans_unlock(trans);
2346 #ifdef CONFIG_BCACHEFS_DEBUG
2347 mutex_lock(&trans->c->btree_trans_lock);
2348 list_del(&trans->list);
2349 mutex_unlock(&trans->c->btree_trans_lock);
2352 bch2_journal_preres_put(&trans->c->journal, &trans->journal_preres);
2354 kfree(trans->fs_usage_deltas);
2356 if (trans->used_mempool)
2357 mempool_free(trans->iters, &trans->c->btree_iters_pool);
2358 else if (trans->iters != trans->iters_onstack)
2359 kfree(trans->iters);
2360 trans->mem = (void *) 0x1;
2361 trans->iters = (void *) 0x1;
2363 return trans->error ? -EIO : 0;
2366 static void bch2_btree_iter_node_to_text(struct printbuf *out,
2367 struct btree_bkey_cached_common *_b,
2368 enum btree_iter_type type)
2370 pr_buf(out, " %px l=%u %s:",
2371 _b, _b->level, bch2_btree_ids[_b->btree_id]);
2372 bch2_bpos_to_text(out, btree_node_pos(_b, type));
2375 void bch2_btree_trans_to_text(struct printbuf *out, struct bch_fs *c)
2377 #ifdef CONFIG_BCACHEFS_DEBUG
2378 struct btree_trans *trans;
2379 struct btree_iter *iter;
2383 mutex_lock(&c->btree_trans_lock);
2384 list_for_each_entry(trans, &c->btree_trans_list, list) {
2385 pr_buf(out, "%i %px %ps\n", trans->pid, trans, (void *) trans->ip);
2387 trans_for_each_iter(trans, iter) {
2388 if (!iter->nodes_locked)
2391 pr_buf(out, " iter %u %s:",
2393 bch2_btree_ids[iter->btree_id]);
2394 bch2_bpos_to_text(out, iter->pos);
2397 for (l = 0; l < BTREE_MAX_DEPTH; l++) {
2398 if (btree_node_locked(iter, l)) {
2399 pr_buf(out, " %s l=%u ",
2400 btree_node_intent_locked(iter, l) ? "i" : "r", l);
2401 bch2_btree_iter_node_to_text(out,
2402 (void *) iter->l[l].b,
2403 btree_iter_type(iter));
2409 b = READ_ONCE(trans->locking);
2411 pr_buf(out, " locking iter %u l=%u %s:",
2412 trans->locking_iter_idx,
2413 trans->locking_level,
2414 bch2_btree_ids[trans->locking_btree_id]);
2415 bch2_bpos_to_text(out, trans->locking_pos);
2418 pr_buf(out, " node ");
2419 bch2_btree_iter_node_to_text(out,
2421 btree_iter_type(&trans->iters[trans->locking_iter_idx]));
2425 mutex_unlock(&c->btree_trans_lock);
2429 void bch2_fs_btree_iter_exit(struct bch_fs *c)
2431 mempool_exit(&c->btree_iters_pool);
2434 int bch2_fs_btree_iter_init(struct bch_fs *c)
2436 unsigned nr = BTREE_ITER_MAX;
2438 INIT_LIST_HEAD(&c->btree_trans_list);
2439 mutex_init(&c->btree_trans_lock);
2441 return mempool_init_kmalloc_pool(&c->btree_iters_pool, 1,
2442 sizeof(struct btree_iter) * nr +
2443 sizeof(struct btree_insert_entry) * nr +
2444 sizeof(struct btree_insert_entry) * nr);