journal: bugfix: avoid deleting zero-byte prefix...

...when deleting rootzone-related records
because it also deletes global metadata

src/knot/journal/journal_basic.c

@@ -36,6 +36,19 @@ MDB_val journal_changeset_to_chunk_key(const changeset_t *ch, uint32_t chunk_id)
 	}
 }
 
+MDB_val journal_zone_prefix(const knot_dname_t *zone)
+{
+	return knot_lmdb_make_key("NI", zone, (uint32_t)0);
+}
+
+void journal_del_zone(knot_lmdb_txn_t *txn, const knot_dname_t *zone)
+{
+	assert(txn->is_rw);
+	MDB_val prefix = journal_zone_prefix(zone);
+	knot_lmdb_del_prefix(txn, &prefix);
+	free(prefix.mv_data);
+}
+
 void journal_make_header(void *chunk, uint32_t ch_serial_to)
 {
 	knot_lmdb_make_key_part(chunk, JOURNAL_HEADER_SIZE, "IILLL", ch_serial_to,

src/knot/journal/journal_basic.h

@@ -58,6 +58,16 @@ MDB_val journal_changeset_id_to_key(bool zone_in_journal, uint32_t serial, const
  */
 MDB_val journal_changeset_to_chunk_key(const changeset_t *ch, uint32_t chunk_id);
 
+/*!
+ * \brief Return a key prefix to operate with all zone-related records.
+ */
+MDB_val journal_zone_prefix(const knot_dname_t *zone);
+
+/*!
+ * \brief Delete all zone-related records from journal with open read-write txn.
+ */
+void journal_del_zone(knot_lmdb_txn_t *txn, const knot_dname_t *zone);
+
 /*!
  * \brief Initialise chunk header.
  *

src/knot/journal/journal_metadata.c

@@ -295,8 +295,7 @@ int journal_scrape_with_md(zone_journal_t j, bool check_existence)
 	knot_lmdb_begin(j.db, &txn, true);
 
 	update_last_inserter(&txn, NULL);
-	MDB_val prefix = { knot_dname_size(j.zone), (void *)j.zone };
-	knot_lmdb_del_prefix(&txn, &prefix);
+	journal_del_zone(&txn, j.zone);
 
 	knot_lmdb_commit(&txn);
 	return txn.ret;
@@ -313,8 +312,9 @@ int journal_copy_with_md(knot_lmdb_db_t *from, knot_lmdb_db_t *to, const knot_dn
 	knot_lmdb_begin(from, &tr, true);
 	knot_lmdb_begin(to, &tw, true);
 	update_last_inserter(&tr, NULL);
-	MDB_val prefix = { knot_dname_size(zone), (void *)zone };
+	MDB_val prefix = journal_zone_prefix(zone);
 	knot_lmdb_copy_prefix(&tr, &tw, &prefix);
+	free(prefix.mv_data);
 	knot_lmdb_commit(&tw);
 	knot_lmdb_commit(&tr);
 done:

src/knot/journal/journal_write.c

@@ -225,8 +225,7 @@ int journal_insert_zone(zone_journal_t j, const zone_contents_t *z)
 	knot_lmdb_begin(j.db, &txn, true);
 
 	update_last_inserter(&txn, j.zone);
-	MDB_val prefix = { knot_dname_size(j.zone), (void *)j.zone };
-	knot_lmdb_del_prefix(&txn, &prefix);
+	journal_del_zone(&txn, j.zone);
 
 	journal_write_zone(&txn, z);
 
@@ -282,8 +281,7 @@ int journal_insert(zone_journal_t j, const changeset_t *ch, const changeset_t *e
 		if (journal_contains(&txn, true, 0, j.zone)) {
 			txn.ret = KNOT_ESEMCHECK;
 		} else {
-			MDB_val prefix = { knot_dname_size(j.zone), (void *)j.zone };
-			knot_lmdb_del_prefix(&txn, &prefix);
+			journal_del_zone(&txn, j.zone);
 			memset(&md, 0, sizeof(md));
 		}
 	}