+struct bkey_i *bch2_journal_keys_peek_upto(struct bch_fs *c, enum btree_id btree_id,
+ unsigned level, struct bpos pos,
+ struct bpos end_pos, size_t *idx)
+{
+ struct journal_keys *keys = &c->journal_keys;
+ unsigned iters = 0;
+ struct journal_key *k;
+search:
+ if (!*idx)
+ *idx = __bch2_journal_key_search(keys, btree_id, level, pos);
+
+ while ((k = *idx < keys->nr ? idx_to_key(keys, *idx) : NULL)) {
+ if (__journal_key_cmp(btree_id, level, end_pos, k) < 0)
+ return NULL;
+
+ if (__journal_key_cmp(btree_id, level, pos, k) <= 0 &&
+ !k->overwritten)
+ return k->k;
+
+ (*idx)++;
+ iters++;
+ if (iters == 10) {
+ *idx = 0;
+ goto search;
+ }
+ }
+
+ return NULL;
+}
+
+struct bkey_i *bch2_journal_keys_peek_slot(struct bch_fs *c, enum btree_id btree_id,
+ unsigned level, struct bpos pos)
+{
+ size_t idx = 0;
+
+ return bch2_journal_keys_peek_upto(c, btree_id, level, pos, pos, &idx);
+}
+
+static void journal_iters_fix(struct bch_fs *c)
+{
+ struct journal_keys *keys = &c->journal_keys;
+ /* The key we just inserted is immediately before the gap: */
+ size_t gap_end = keys->gap + (keys->size - keys->nr);
+ struct btree_and_journal_iter *iter;
+
+ /*
+ * If an iterator points one after the key we just inserted, decrement
+ * the iterator so it points at the key we just inserted - if the
+ * decrement was unnecessary, bch2_btree_and_journal_iter_peek() will
+ * handle that:
+ */
+ list_for_each_entry(iter, &c->journal_iters, journal.list)
+ if (iter->journal.idx == gap_end)
+ iter->journal.idx = keys->gap - 1;
+}
+
+static void journal_iters_move_gap(struct bch_fs *c, size_t old_gap, size_t new_gap)
+{
+ struct journal_keys *keys = &c->journal_keys;
+ struct journal_iter *iter;
+ size_t gap_size = keys->size - keys->nr;
+
+ list_for_each_entry(iter, &c->journal_iters, list) {
+ if (iter->idx > old_gap)
+ iter->idx -= gap_size;
+ if (iter->idx >= new_gap)
+ iter->idx += gap_size;
+ }
+}
+
+int bch2_journal_key_insert_take(struct bch_fs *c, enum btree_id id,
+ unsigned level, struct bkey_i *k)