MDEV-19347: Mariabackup does not honor ignore_db_dirs from server

config.

The solution is to read the system variable value on startup and to fill
databases_exclude_hash.

xb_load_list_string() became non-static and was reformatted. The system
variable value is read and processed in get_mysql_vars(), which was also
reformatted.

extra/mariabackup/backup_mysql.cc

@@ -326,36 +326,36 @@ check_server_version(unsigned long version_number,
 /*********************************************************************//**
 Receive options important for XtraBackup from MySQL server.
 @return	true on success. */
-bool
-get_mysql_vars(MYSQL *connection)
+bool get_mysql_vars(MYSQL *connection)
 {
-	char *gtid_mode_var = NULL;
-	char *version_var = NULL;
-	char *version_comment_var = NULL;
-	char *innodb_version_var = NULL;
-	char *have_backup_locks_var = NULL;
-	char *log_bin_var = NULL;
+  char *gtid_mode_var= NULL;
+  char *version_var= NULL;
+  char *version_comment_var= NULL;
+  char *innodb_version_var= NULL;
+  char *have_backup_locks_var= NULL;
+  char *log_bin_var= NULL;
   char *lock_wait_timeout_var= NULL;
-	char *wsrep_on_var = NULL;
-	char *slave_parallel_workers_var = NULL;
-	char *gtid_slave_pos_var = NULL;
-	char *innodb_buffer_pool_filename_var = NULL;
-	char *datadir_var = NULL;
-	char *innodb_log_group_home_dir_var = NULL;
-	char *innodb_log_file_size_var = NULL;
-	char *innodb_log_files_in_group_var = NULL;
-	char *innodb_data_file_path_var = NULL;
-	char *innodb_data_home_dir_var = NULL;
-	char *innodb_undo_directory_var = NULL;
-	char *innodb_page_size_var = NULL;
-	char *innodb_undo_tablespaces_var = NULL;
-	char *page_zip_level_var = NULL;
+  char *wsrep_on_var= NULL;
+  char *slave_parallel_workers_var= NULL;
+  char *gtid_slave_pos_var= NULL;
+  char *innodb_buffer_pool_filename_var= NULL;
+  char *datadir_var= NULL;
+  char *innodb_log_group_home_dir_var= NULL;
+  char *innodb_log_file_size_var= NULL;
+  char *innodb_log_files_in_group_var= NULL;
+  char *innodb_data_file_path_var= NULL;
+  char *innodb_data_home_dir_var= NULL;
+  char *innodb_undo_directory_var= NULL;
+  char *innodb_page_size_var= NULL;
+  char *innodb_undo_tablespaces_var= NULL;
+  char *page_zip_level_var= NULL;
+  char *ignore_db_dirs= NULL;
   char *endptr;
-	unsigned long server_version = mysql_get_server_version(connection);
+  unsigned long server_version= mysql_get_server_version(connection);
 
-	bool ret = true;
+  bool ret= true;
 
-	mysql_variable mysql_vars[] = {
+  mysql_variable mysql_vars[]= {
       {"have_backup_locks", &have_backup_locks_var},
       {"log_bin", &log_bin_var},
       {"lock_wait_timeout", &lock_wait_timeout_var},
@@ -366,8 +366,7 @@ get_mysql_vars(MYSQL *connection)
       {"wsrep_on", &wsrep_on_var},
       {"slave_parallel_workers", &slave_parallel_workers_var},
       {"gtid_slave_pos", &gtid_slave_pos_var},
-		{"innodb_buffer_pool_filename",
-			&innodb_buffer_pool_filename_var},
+      {"innodb_buffer_pool_filename", &innodb_buffer_pool_filename_var},
       {"datadir", &datadir_var},
       {"innodb_log_group_home_dir", &innodb_log_group_home_dir_var},
       {"innodb_log_file_size", &innodb_log_file_size_var},
@@ -378,74 +377,88 @@ get_mysql_vars(MYSQL *connection)
       {"innodb_page_size", &innodb_page_size_var},
       {"innodb_undo_tablespaces", &innodb_undo_tablespaces_var},
       {"innodb_compression_level", &page_zip_level_var},
-		{NULL, NULL}
-	};
+      {"ignore_db_dirs", &ignore_db_dirs},
+      {NULL, NULL}};
 
-	read_mysql_variables(connection, "SHOW VARIABLES",
-				mysql_vars, true);
+  read_mysql_variables(connection, "SHOW VARIABLES", mysql_vars, true);
 
-	if (have_backup_locks_var != NULL && !opt_no_backup_locks) {
-		have_backup_locks = true;
+  if (have_backup_locks_var != NULL && !opt_no_backup_locks)
+  {
+    have_backup_locks= true;
   }
 
-	if (opt_binlog_info == BINLOG_INFO_AUTO) {
+  if (opt_binlog_info == BINLOG_INFO_AUTO)
+  {
     if (log_bin_var != NULL && !strcmp(log_bin_var, "ON"))
-			opt_binlog_info = BINLOG_INFO_ON;
+      opt_binlog_info= BINLOG_INFO_ON;
     else
-			opt_binlog_info = BINLOG_INFO_OFF;
+      opt_binlog_info= BINLOG_INFO_OFF;
   }
 
-	if (lock_wait_timeout_var != NULL) {
-		have_lock_wait_timeout = true;
+  if (lock_wait_timeout_var != NULL)
+  {
+    have_lock_wait_timeout= true;
   }
 
-	if (wsrep_on_var != NULL) {
-		have_galera_enabled = true;
+  if (wsrep_on_var != NULL)
+  {
+    have_galera_enabled= true;
   }
 
   /* Check server version compatibility and detect server flavor */
 
-	if (!(ret = check_server_version(server_version, version_var,
-					 version_comment_var,
-					 innodb_version_var))) {
+  if (!(ret= check_server_version(server_version, version_var,
+                                  version_comment_var, innodb_version_var)))
+  {
     goto out;
   }
 
-	if (server_version > 50500) {
-		have_flush_engine_logs = true;
+  if (server_version > 50500)
+  {
+    have_flush_engine_logs= true;
   }
 
-	if (slave_parallel_workers_var != NULL
-		&& atoi(slave_parallel_workers_var) > 0) {
-		have_multi_threaded_slave = true;
+  if (slave_parallel_workers_var != NULL &&
+      atoi(slave_parallel_workers_var) > 0)
+  {
+    have_multi_threaded_slave= true;
   }
 
-	if (innodb_buffer_pool_filename_var != NULL) {
-		buffer_pool_filename = strdup(innodb_buffer_pool_filename_var);
+  if (innodb_buffer_pool_filename_var != NULL)
+  {
+    buffer_pool_filename= strdup(innodb_buffer_pool_filename_var);
   }
 
   if ((gtid_mode_var && strcmp(gtid_mode_var, "ON") == 0) ||
-	    (gtid_slave_pos_var && *gtid_slave_pos_var)) {
-		have_gtid_slave = true;
+      (gtid_slave_pos_var && *gtid_slave_pos_var))
+  {
+    have_gtid_slave= true;
   }
 
   msg("Using server version %s", version_var);
 
-	if (!(ret = detect_mysql_capabilities_for_backup())) {
+  if (!(ret= detect_mysql_capabilities_for_backup()))
+  {
     goto out;
   }
 
   /* make sure datadir value is the same in configuration file */
-	if (check_if_param_set("datadir")) {
-		if (!directory_exists(mysql_data_home, false)) {
+  if (check_if_param_set("datadir"))
+  {
+    if (!directory_exists(mysql_data_home, false))
+    {
       msg("Warning: option 'datadir' points to "
-			    "nonexistent directory '%s'", mysql_data_home);
+          "nonexistent directory '%s'",
+          mysql_data_home);
     }
-		if (!directory_exists(datadir_var, false)) {
+    if (!directory_exists(datadir_var, false))
+    {
       msg("Warning: MySQL variable 'datadir' points to "
-			    "nonexistent directory '%s'", datadir_var);
+          "nonexistent directory '%s'",
+          datadir_var);
     }
-		if (!equal_paths(mysql_data_home, datadir_var)) {
+    if (!equal_paths(mysql_data_home, datadir_var))
+    {
       msg("Warning: option 'datadir' has different "
           "values:\n"
           "  '%s' in defaults file\n"
@@ -455,65 +468,70 @@ get_mysql_vars(MYSQL *connection)
   }
 
   /* get some default values is they are missing from my.cnf */
-	if (datadir_var && *datadir_var) {
+  if (datadir_var && *datadir_var)
+  {
     strmake(mysql_real_data_home, datadir_var, FN_REFLEN - 1);
     mysql_data_home= mysql_real_data_home;
   }
 
-	if (innodb_data_file_path_var && *innodb_data_file_path_var) {
-		innobase_data_file_path = my_strdup(
-			innodb_data_file_path_var, MYF(MY_FAE));
+  if (innodb_data_file_path_var && *innodb_data_file_path_var)
+  {
+    innobase_data_file_path= my_strdup(innodb_data_file_path_var, MYF(MY_FAE));
   }
 
-	if (innodb_data_home_dir_var) {
-		innobase_data_home_dir = my_strdup(
-			innodb_data_home_dir_var, MYF(MY_FAE));
+  if (innodb_data_home_dir_var)
+  {
+    innobase_data_home_dir= my_strdup(innodb_data_home_dir_var, MYF(MY_FAE));
   }
 
-	if (innodb_log_group_home_dir_var
-	    && *innodb_log_group_home_dir_var) {
-		srv_log_group_home_dir = my_strdup(
-			innodb_log_group_home_dir_var, MYF(MY_FAE));
+  if (innodb_log_group_home_dir_var && *innodb_log_group_home_dir_var)
+  {
+    srv_log_group_home_dir=
+        my_strdup(innodb_log_group_home_dir_var, MYF(MY_FAE));
   }
 
-	if (innodb_undo_directory_var && *innodb_undo_directory_var) {
-		srv_undo_dir = my_strdup(
-			innodb_undo_directory_var, MYF(MY_FAE));
+  if (innodb_undo_directory_var && *innodb_undo_directory_var)
+  {
+    srv_undo_dir= my_strdup(innodb_undo_directory_var, MYF(MY_FAE));
   }
 
-	if (innodb_log_files_in_group_var) {
-		srv_n_log_files = strtol(
-			innodb_log_files_in_group_var, &endptr, 10);
+  if (innodb_log_files_in_group_var)
+  {
+    srv_n_log_files= strtol(innodb_log_files_in_group_var, &endptr, 10);
     ut_ad(*endptr == 0);
   }
 
-	if (innodb_log_file_size_var) {
-		srv_log_file_size = strtoll(
-			innodb_log_file_size_var, &endptr, 10);
+  if (innodb_log_file_size_var)
+  {
+    srv_log_file_size= strtoll(innodb_log_file_size_var, &endptr, 10);
     ut_ad(*endptr == 0);
   }
 
-	if (innodb_page_size_var) {
-		innobase_page_size = strtoll(
-			innodb_page_size_var, &endptr, 10);
+  if (innodb_page_size_var)
+  {
+    innobase_page_size= strtoll(innodb_page_size_var, &endptr, 10);
     ut_ad(*endptr == 0);
   }
 
-	if (innodb_undo_tablespaces_var) {
-		srv_undo_tablespaces = strtoul(innodb_undo_tablespaces_var,
-					       &endptr, 10);
+  if (innodb_undo_tablespaces_var)
+  {
+    srv_undo_tablespaces= strtoul(innodb_undo_tablespaces_var, &endptr, 10);
     ut_ad(*endptr == 0);
   }
 
-	if (page_zip_level_var != NULL) {
-		page_zip_level = strtoul(page_zip_level_var, &endptr, 10);
+  if (page_zip_level_var != NULL)
+  {
+    page_zip_level= strtoul(page_zip_level_var, &endptr, 10);
     ut_ad(*endptr == 0);
   }
 
+  if (ignore_db_dirs)
+    xb_load_list_string(ignore_db_dirs, ",", register_ignore_db_dirs_filter);
+
 out:
   free_mysql_variables(mysql_vars);
 
-	return(ret);
+  return (ret);
 }
 
 /*********************************************************************//**

extra/mariabackup/xtrabackup.cc

@@ -3632,6 +3632,11 @@ xb_register_exclude_filter_entry(
 				 &tables_exclude_hash);
 }
 
+void register_ignore_db_dirs_filter(const char *name)
+{
+  xb_add_filter(name, &databases_exclude_hash);
+}
+
 /***********************************************************************
 Register new table for the filter.  */
 static
@@ -3694,25 +3699,23 @@ xb_register_exclude_regex(
 
 typedef void (*insert_entry_func_t)(const char*);
 
-/***********************************************************************
-Scan string and load filter entries from it.  */
-static
-void
-xb_load_list_string(
-/*================*/
-	char* list,			/*!< in: string representing a list */
-	const char* delimiters,		/*!< in: delimiters of entries */
-	insert_entry_func_t ins)	/*!< in: callback to add entry */
+/* Scan string and load filter entries from it.
+@param[in] list string representing a list
+@param[in] delimiters delimiters of entries
+@param[in] ins callback to add entry */
+void xb_load_list_string(char *list, const char *delimiters,
+                         insert_entry_func_t ins)
 {
-	char*	p;
-	char*	saveptr;
+  char *p;
+  char *saveptr;
 
-	p = strtok_r(list, delimiters, &saveptr);
-	while (p) {
+  p= strtok_r(list, delimiters, &saveptr);
+  while (p)
+  {
 
     ins(p);
 
-		p = strtok_r(NULL, delimiters, &saveptr);
+    p= strtok_r(NULL, delimiters, &saveptr);
   }
 }
 

extra/mariabackup/xtrabackup.h

@@ -194,4 +194,14 @@ void mdl_lock_init();
 void mdl_lock_table(ulint space_id);
 void mdl_unlock_all();
 bool ends_with(const char *str, const char *suffix);
+
+typedef void (*insert_entry_func_t)(const char*);
+
+/* Scan string and load filter entries from it.
+@param[in] list string representing a list
+@param[in] delimiters delimiters of entries
+@param[in] ins callback to add entry */
+void xb_load_list_string(char *list, const char *delimiters,
+                         insert_entry_func_t ins);
+void register_ignore_db_dirs_filter(const char *name);
 #endif /* XB_XTRABACKUP_H */

mysql-test/suite/mariabackup/partial_exclude.opt

+--ignore-db-dirs=db3
+--ignore-db-dirs=db4

mysql-test/suite/mariabackup/partial_exclude.result

+select @@ignore_db_dirs;
+@@ignore_db_dirs
+db3,db4
 CREATE TABLE t1(i INT) ENGINE INNODB;
 INSERT INTO t1 VALUES(1);
 CREATE TABLE t2(i int) ENGINE INNODB;

mysql-test/suite/mariabackup/partial_exclude.test

 #--source include/innodb_page_size.inc
 
 # Test --databases-exclude and --tables-exclude feature of xtrabackup 2.3.8
+select @@ignore_db_dirs;
+
+let $MYSQLD_DATADIR= `select @@datadir`;
+
+mkdir $MYSQLD_DATADIR/db3;
+mkdir $MYSQLD_DATADIR/db4;
+mkdir $MYSQLD_DATADIR/db5;
 
 CREATE TABLE t1(i INT) ENGINE INNODB;
 INSERT INTO t1 VALUES(1);
@@ -24,8 +31,19 @@ list_files $targetdir/test *.ibd;
 # check that db2 database is not in the backup (excluded)
 --error 1
 list_files $targetdir/db2 *.ibd;
+# check that db3 database is not in the backup (excluded)
+--error 1
+list_files $targetdir/db3 *.ibd;
+# check that db4 database is not in the backup (excluded)
+--error 1
+list_files $targetdir/db4 *.ibd;
+# check that db5 database is in the backup
+list_files $targetdir/db5 *.ibd;
 
 DROP TABLE t1;
 DROP TABLE t2;
 DROP DATABASE db2;
+rmdir $MYSQLD_DATADIR/db3;
+rmdir $MYSQLD_DATADIR/db4;
+rmdir $MYSQLD_DATADIR/db5;
 rmdir $targetdir;