+ discard_key_type = a->data_type == BCH_DATA_need_discard ? KEY_TYPE_set : 0;
+ bch2_btree_iter_set_pos(discard_iter, alloc_k.k->p);
+ k = bch2_btree_iter_peek_slot(discard_iter);
+ ret = bkey_err(k);
+ if (ret)
+ goto err;
+
+ if (k.k->type != discard_key_type &&
+ (c->opts.reconstruct_alloc ||
+ fsck_err(c, need_discard_key_wrong,
+ "incorrect key in need_discard btree (got %s should be %s)\n"
+ " %s",
+ bch2_bkey_types[k.k->type],
+ bch2_bkey_types[discard_key_type],
+ (bch2_bkey_val_to_text(&buf, c, alloc_k), buf.buf)))) {
+ struct bkey_i *update =
+ bch2_trans_kmalloc(trans, sizeof(*update));
+
+ ret = PTR_ERR_OR_ZERO(update);
+ if (ret)
+ goto err;
+
+ bkey_init(&update->k);
+ update->k.type = discard_key_type;
+ update->k.p = discard_iter->pos;
+
+ ret = bch2_trans_update(trans, discard_iter, update, 0);
+ if (ret)
+ goto err;
+ }
+
+ freespace_key_type = a->data_type == BCH_DATA_free ? KEY_TYPE_set : 0;
+ bch2_btree_iter_set_pos(freespace_iter, alloc_freespace_pos(alloc_k.k->p, *a));
+ k = bch2_btree_iter_peek_slot(freespace_iter);
+ ret = bkey_err(k);
+ if (ret)
+ goto err;
+
+ if (k.k->type != freespace_key_type &&
+ (c->opts.reconstruct_alloc ||
+ fsck_err(c, freespace_key_wrong,
+ "incorrect key in freespace btree (got %s should be %s)\n"
+ " %s",
+ bch2_bkey_types[k.k->type],
+ bch2_bkey_types[freespace_key_type],
+ (printbuf_reset(&buf),
+ bch2_bkey_val_to_text(&buf, c, alloc_k), buf.buf)))) {
+ struct bkey_i *update =
+ bch2_trans_kmalloc(trans, sizeof(*update));
+
+ ret = PTR_ERR_OR_ZERO(update);
+ if (ret)
+ goto err;
+
+ bkey_init(&update->k);
+ update->k.type = freespace_key_type;
+ update->k.p = freespace_iter->pos;
+ bch2_key_resize(&update->k, 1);
+
+ ret = bch2_trans_update(trans, freespace_iter, update, 0);
+ if (ret)
+ goto err;
+ }
+
+ bch2_btree_iter_set_pos(bucket_gens_iter, alloc_gens_pos(alloc_k.k->p, &gens_offset));
+ k = bch2_btree_iter_peek_slot(bucket_gens_iter);
+ ret = bkey_err(k);
+ if (ret)
+ goto err;
+
+ if (a->gen != alloc_gen(k, gens_offset) &&
+ (c->opts.reconstruct_alloc ||
+ fsck_err(c, bucket_gens_key_wrong,
+ "incorrect gen in bucket_gens btree (got %u should be %u)\n"
+ " %s",
+ alloc_gen(k, gens_offset), a->gen,
+ (printbuf_reset(&buf),
+ bch2_bkey_val_to_text(&buf, c, alloc_k), buf.buf)))) {
+ struct bkey_i_bucket_gens *g =
+ bch2_trans_kmalloc(trans, sizeof(*g));
+
+ ret = PTR_ERR_OR_ZERO(g);
+ if (ret)
+ goto err;