MDEV-26870 --skip-symbolic-links does not disallow .isl file creation

The InnoDB DATA DIRECTORY attribute is not implemented via
symbolic links but something similar, *.isl files that contain
the names of data files.

InnoDB failed to ignore the DATA DIRECTORY attribute even though
the server was started with --skip-symbolic-links.

Native ALTER TABLE in InnoDB will retain the DATA DIRECTORY attribute
of the table, no matter if the table will be rebuilt or not.

Generic ALTER TABLE (with ALGORITHM=COPY) as well as TRUNCATE TABLE
will discard the DATA DIRECTORY attribute.

All tests have been run with and without the ./mtr option
--mysqld=--skip-symbolic-links
and some tests that use the InnoDB DATA DIRECTORY attribute
have been adjusted for this.

include/my_sys.h

 /* Copyright (c) 2000, 2013, Oracle and/or its affiliates.
-   Copyright (c) 2010, 2021, MariaDB Corporation.
+   Copyright (c) 2010, 2022, MariaDB Corporation.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -276,7 +276,7 @@ extern int my_umask_dir,
 	   my_recived_signals,	/* Signals we have got */
 	   my_safe_to_handle_signal, /* Set when allowed to SIGTSTP */
 	   my_dont_interrupt;	/* call remember_intr when set */
-extern my_bool my_use_symdir;
+extern MYSQL_PLUGIN_IMPORT my_bool my_use_symdir;
 
 extern ulong	my_default_record_cache_size;
 extern MYSQL_PLUGIN_IMPORT my_bool my_disable_locking;

mysql-test/r/information_schema_inno.result

-DROP TABLE IF EXISTS t1,t2,t3;
 CREATE TABLE t1 (id INT NOT NULL, PRIMARY KEY (id)) ENGINE=INNODB;
 CREATE TABLE t2 (id INT PRIMARY KEY, t1_id INT, INDEX par_ind (t1_id, id),
 FOREIGN KEY (t1_id) REFERENCES t1(id)  ON DELETE CASCADE,

mysql-test/suite/encryption/t/innodb-first-page-read.test

 -- source include/have_innodb.inc
 -- source include/have_file_key_management_plugin.inc
 -- source include/not_embedded.inc
+-- source include/have_symlink.inc
 
 --disable_warnings
 SET GLOBAL innodb_file_format = `Barracuda`;

mysql-test/suite/innodb/r/skip_symbolic_links.result

+SELECT @@have_symlink;
+@@have_symlink
+DISABLED
+CREATE TABLE t1(a INT) ENGINE=InnoDB DATA DIRECTORY 'MYSQL_TMP_DIR';
+Warnings:
+Warning	1618	<DATA DIRECTORY> option ignored
+DROP TABLE t1;
+CREATE TABLE t1(a INT) ENGINE=InnoDB;
+ALTER TABLE t1 DATA DIRECTORY 'MYSQL_TMP_DIR';
+Warnings:
+Warning	1618	<DATA DIRECTORY> option ignored
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` int(11) DEFAULT NULL
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+DROP TABLE t1;
+CREATE TABLE t1(a INT PRIMARY KEY, b INT) ENGINE=InnoDB
+DATA DIRECTORY 'MYSQL_TMP_DIR';
+CREATE TABLE t2(a INT PRIMARY KEY, b INT) ENGINE=InnoDB
+DATA DIRECTORY 'MYSQL_TMP_DIR';
+TRUNCATE TABLE t1;
+TRUNCATE TABLE t2;
+ALTER TABLE t1 FORCE, ALGORITHM=INPLACE;
+Warnings:
+Warning	1618	<DATA DIRECTORY> option ignored
+ALTER TABLE t2 FORCE, ALGORITHM=COPY;
+Warnings:
+Warning	1618	<DATA DIRECTORY> option ignored
+OPTIMIZE TABLE t1;
+Table	Op	Msg_type	Msg_text
+test.t1	optimize	note	Table does not support optimize, doing recreate + analyze instead
+test.t1	optimize	status	OK
+Warnings:
+Warning	1618	<DATA DIRECTORY> option ignored
+t1.ibd
+DROP TABLE t2;
+RENAME TABLE t1 TO t2;
+ALTER TABLE t2 ADD UNIQUE INDEX(b), RENAME TO t3;
+Warnings:
+Warning	1618	<DATA DIRECTORY> option ignored
+ALTER TABLE t3 RENAME TO t2;
+ALTER TABLE t2 DROP INDEX b, RENAME TO t1;
+Warnings:
+Warning	1618	<DATA DIRECTORY> option ignored
+ALTER TABLE t1 CHANGE b c INT;
+Warnings:
+Warning	1618	<DATA DIRECTORY> option ignored
+ALTER TABLE t1 CHANGE c b INT NOT NULL;
+Warnings:
+Warning	1618	<DATA DIRECTORY> option ignored
+t1.ibd
+TRUNCATE TABLE t1;
+DROP TABLE t1;

mysql-test/suite/innodb/t/101_compatibility.test

 --source include/innodb_page_size.inc
 --source include/not_embedded.inc
+--source include/have_symlink.inc
 
 -- echo #
 -- echo # MDEV-11623 MariaDB 10.1 fails to start datadir created with

mysql-test/suite/innodb/t/create_isl_with_direct.test

 --source include/not_embedded.inc
 --source include/have_innodb.inc
+--source include/have_symlink.inc
 
 --disable_query_log
 CALL mtr.add_suppression(".*Failed to set O_DIRECT on file.*");

mysql-test/suite/innodb/t/innodb-wl5980-alter.test

@@ -4,6 +4,7 @@
 --echo #
 
 --source include/have_innodb.inc
+--source include/have_symlink.inc
 
 --disable_query_log
 # These values can change during the test

mysql-test/suite/innodb/t/innodb-wl5980-debug.test

@@ -8,6 +8,7 @@
 --source include/not_embedded.inc
 --source include/have_debug.inc
 --source include/have_innodb.inc
+--source include/have_symlink.inc
 
 # These messages are expected in the log
 call mtr.add_suppression("Cannot find space id [0-9]+ in the tablespace memory cache");

mysql-test/suite/innodb/t/restart.test

 --source include/innodb_page_size.inc
 --source include/not_embedded.inc
+--source include/have_symlink.inc
 
 let datadir= `select @@datadir`;
 let page_size= `select @@innodb_page_size`;

mysql-test/suite/innodb/t/skip_symbolic_links.opt

+--skip-symbolic-links

mysql-test/suite/innodb/t/skip_symbolic_links.test

+--source include/have_innodb.inc
+--source include/not_windows.inc
+
+SELECT @@have_symlink;
+--replace_result $MYSQL_TMP_DIR MYSQL_TMP_DIR
+eval CREATE TABLE t1(a INT) ENGINE=InnoDB DATA DIRECTORY '$MYSQL_TMP_DIR';
+DROP TABLE t1;
+CREATE TABLE t1(a INT) ENGINE=InnoDB;
+
+--replace_result $MYSQL_TMP_DIR MYSQL_TMP_DIR
+eval ALTER TABLE t1 DATA DIRECTORY '$MYSQL_TMP_DIR';
+SHOW CREATE TABLE t1;
+
+DROP TABLE t1;
+
+--let $restart_parameters=--symbolic-links
+--source include/restart_mysqld.inc
+
+--replace_result $MYSQL_TMP_DIR MYSQL_TMP_DIR
+eval CREATE TABLE t1(a INT PRIMARY KEY, b INT) ENGINE=InnoDB
+DATA DIRECTORY '$MYSQL_TMP_DIR';
+--replace_result $MYSQL_TMP_DIR MYSQL_TMP_DIR
+eval CREATE TABLE t2(a INT PRIMARY KEY, b INT) ENGINE=InnoDB
+DATA DIRECTORY '$MYSQL_TMP_DIR';
+
+TRUNCATE TABLE t1;
+TRUNCATE TABLE t2;
+
+--let $restart_parameters=
+--source include/restart_mysqld.inc
+
+# Native ALTER will retain DATA DIRECTORY
+ALTER TABLE t1 FORCE, ALGORITHM=INPLACE;
+ALTER TABLE t2 FORCE, ALGORITHM=COPY;
+OPTIMIZE TABLE t1;
+--list_files $MYSQL_TMP_DIR/test
+DROP TABLE t2;
+
+RENAME TABLE t1 TO t2;
+ALTER TABLE t2 ADD UNIQUE INDEX(b), RENAME TO t3;
+
+ALTER TABLE t3 RENAME TO t2;
+ALTER TABLE t2 DROP INDEX b, RENAME TO t1;
+ALTER TABLE t1 CHANGE b c INT;
+ALTER TABLE t1 CHANGE c b INT NOT NULL;
+
+--list_files $MYSQL_TMP_DIR/test
+# TRUNCATE TABLE will discard DATA DIRECTORY.
+TRUNCATE TABLE t1;
+--list_files $MYSQL_TMP_DIR/test
+DROP TABLE t1;

mysql-test/suite/innodb_zip/t/restart.test

@@ -4,6 +4,7 @@
 --source include/innodb_page_size_small.inc
 --source include/have_partition.inc
 --source include/not_embedded.inc
+--source include/have_symlink.inc
 SET default_storage_engine=InnoDB;
 LET $MYSQLD_DATADIR = `select @@datadir`;
 LET $INNODB_PAGE_SIZE = `select @@innodb_page_size`;

mysql-test/suite/mariabackup/create_with_data_directory_during_backup.test

 --source include/have_debug.inc
+--source include/have_symlink.inc
 let $table_data_dir=$MYSQLTEST_VARDIR/tmp/ddir;
 let $targetdir=$MYSQLTEST_VARDIR/tmp/backup;
 mkdir $table_data_dir;

mysql-test/suite/mariabackup/data_directory.test

+--source include/have_symlink.inc
 let $table_data_dir=$MYSQLTEST_VARDIR/ddir;
 mkdir $table_data_dir;
 --replace_result $table_data_dir table_data_dir

mysql-test/suite/mariabackup/partition_datadir.test

 --source include/have_partition.inc
+--source include/have_symlink.inc
 let $targetdir=$MYSQLTEST_VARDIR/backup;
 mkdir $targetdir;
 mkdir $MYSQLTEST_VARDIR/partitdata;

mysql-test/suite/parts/t/alter_data_directory_innodb.test

 --source include/have_innodb.inc
 --source include/have_partition.inc
+--source include/have_symlink.inc
 
 --echo #
 --echo # MDEV-15953 Alter InnoDB Partitioned Table Moves Files (which were originally not in the datadir) to the datadir

mysql-test/suite/parts/t/reorganize_partition_innodb.test

 --source include/have_innodb.inc
 --source include/have_partition.inc
+--source include/have_symlink.inc
 
 --echo #
 --echo # MDEV-15953 Alter InnoDB Partitioned Table Moves Files (which were originally not in the datadir) to the datadir

mysql-test/t/information_schema_inno.test

 -- source include/testdb_only.inc
 -- source include/have_innodb.inc
---disable_warnings
-DROP TABLE IF EXISTS t1,t2,t3;
---enable_warnings
+-- source include/have_symlink.inc
 
 #
 # Test for KEY_COLUMN_USAGE & TABLE_CONSTRAINTS tables

storage/innobase/handler/ha_innodb.cc

@@ -4,7 +4,7 @@ Copyright (c) 2000, 2020, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2008, 2009 Google Inc.
 Copyright (c) 2009, Percona Inc.
 Copyright (c) 2012, Facebook Inc.
-Copyright (c) 2013, 2021, MariaDB Corporation.
+Copyright (c) 2013, 2022, MariaDB Corporation.
 
 Portions of this file contain modifications contributed and copyrighted by
 Google, Inc. Those modifications are gratefully acknowledged and are described
@@ -11710,9 +11710,12 @@ create_table_info_t::create_options_are_invalid()
 		break;
 	}
 
-	if (m_create_info->data_file_name
-	    && m_create_info->data_file_name[0] != '\0'
-	    && !create_option_data_directory_is_valid()) {
+	if (!m_create_info->data_file_name
+	    || !m_create_info->data_file_name[0]) {
+	} else if (!my_use_symdir) {
+		my_error(WARN_OPTION_IGNORED, MYF(ME_JUST_WARNING),
+			 "DATA DIRECTORY");
+	} else if (!create_option_data_directory_is_valid()) {
 		ret = "DATA DIRECTORY";
 	}
 
@@ -11986,7 +11989,8 @@ create_table_info_t::parse_table_name(
 	  CREATE TABLE ... DATA DIRECTORY={path} TABLESPACE={name}... ;
 	we ignore the DATA DIRECTORY. */
 	if (m_create_info->data_file_name
-	    && m_create_info->data_file_name[0] != '\0') {
+	    && m_create_info->data_file_name[0]
+	    && my_use_symdir) {
 		if (!create_option_data_directory_is_valid()) {
 			push_warning_printf(
 				m_thd, Sql_condition::WARN_LEVEL_WARN,
@@ -12457,8 +12461,9 @@ create_table_info_t::set_tablespace_type(
 	used with TEMPORARY tables. */
 	m_use_data_dir =
 		m_use_file_per_table
-		&& (m_create_info->data_file_name != NULL)
-		&& (m_create_info->data_file_name[0] != '\0');
+		&& m_create_info->data_file_name
+		&& m_create_info->data_file_name[0]
+		&& my_use_symdir;
 }
 
 /** Initialize the create_table_info_t object.