WL#8548 InnoDB: Transparent data encryption

Fixed bug#22842093 ENCRYPTED TABLES BECOME INACCESSIBLE AFTER
UPGRADE TO MYSQL 5.7.12

Author: Allen Lai

storage/innobase/os/os0file.cc

@@ -8700,16 +8700,31 @@ Encryption::get_master_key(ulint master_key_id,
 	ret = my_key_fetch(key_name, &key_type, NULL,
 			   reinterpret_cast<void**>(master_key), &key_len);
 
+	if (key_type) {
+		my_free(key_type);
+	}
+
+	/* For compitable with 5.7.11, we need to try to get master key with
+	server id when get master key failure. */
+	if (ret || *master_key == NULL) {
+		memset(key_name, 0, ENCRYPTION_MASTER_KEY_NAME_MAX_LEN);
+		sprintf(key_name, "%s-%lu-%lu", ENCRYPTION_MASTER_KEY_PRIFIX,
+			server_id, master_key_id);
+
+		ret = my_key_fetch(key_name, &key_type, NULL,
+				   reinterpret_cast<void**>(master_key),
+				   &key_len);
+		if (key_type) {
+			my_free(key_type);
+		}
+	}
+
 	if (ret) {
 		*master_key = NULL;
 		ib::error() << "Encryption can't find master key, please check"
 				" the keyring plugin is loaded.";
 	}
 
-	if (key_type) {
-		my_free(key_type);
-	}
-
 #ifdef UNIV_ENCRYPT_DEBUG
 	if (!ret && *master_key) {
 		fprintf(stderr, "Fetched master key:%lu ", master_key_id);