MDEV-12108 Fix backup for Innodb tables with DATA DIRECTORY

mysql-test/suite/mariabackup/data_directory.result

+CREATE TABLE t(a INT) ENGINE=InnoDB DATA DIRECTORY='table_data_dir';
+INSERT INTO t VALUES(1);
+# xtrabackup backup
+# xtrabackup prepare
+DROP TABLE t;
+# shutdown server
+# remove datadir
+# xtrabackup move back
+# restart server
+SELECT * FROM t;
+a
+1
+DROP TABLE t;

mysql-test/suite/mariabackup/data_directory.test

+let $table_data_dir=$MYSQLTEST_VARDIR/ddir;
+mkdir $table_data_dir;
+--replace_result $table_data_dir table_data_dir
+EVAL CREATE TABLE t(a INT) ENGINE=InnoDB DATA DIRECTORY='$table_data_dir';
+INSERT INTO t VALUES(1);
+echo # xtrabackup backup;
+let $targetdir=$MYSQLTEST_VARDIR/tmp/backup;
+--disable_result_log
+exec  $XTRABACKUP --defaults-file=$MYSQLTEST_VARDIR/my.cnf --backup --target-dir=$targetdir;
+--enable_result_log
+--source include/shutdown_mysqld.inc
+echo # xtrabackup prepare;
+--disable_result_log
+exec $XTRABACKUP  --prepare --target-dir=$targetdir;
+--source include/start_mysqld.inc
+DROP TABLE t;
+rmdir $table_data_dir;
+-- source include/restart_and_restore.inc
+--enable_result_log
+SELECT * FROM t;
+DROP TABLE t;
+rmdir $targetdir;
+rmdir $table_data_dir;

mysql-test/suite/mariabackup/partition_datadir.opt

+--partition
\ No newline at end of file

mysql-test/suite/mariabackup/partition_datadir.result

+CREATE TABLE t(i int)
+ENGINE=InnoDB
+PARTITION BY RANGE (i)
+(PARTITION p0 VALUES LESS THAN (100),
+PARTITION P1 VALUES LESS THAN (200),
+PARTITION p2 VALUES LESS THAN (300) DATA DIRECTORY = "D:/work/10.1/xxx/mysql-test/var/partitdata",
+PARTITION p3 VALUES LESS THAN (400) DATA DIRECTORY = "D:/work/10.1/xxx/mysql-test/var/partitdata",
+PARTITION p4 VALUES LESS THAN MAXVALUE);
+INSERT INTO t VALUES (1), (101), (201), (301), (401);
+DROP TABLE t;
+# shutdown server
+# remove datadir
+# xtrabackup move back
+# restart server
+SELECT * FROM t;
+i
+1
+101
+201
+301
+401
+DROP TABLE t;

mysql-test/suite/mariabackup/partition_datadir.test

+let $targetdir=$MYSQLTEST_VARDIR/backup;
+mkdir $targetdir;
+mkdir $MYSQLTEST_VARDIR/partitdata;
+eval CREATE TABLE t(i int)
+ENGINE=InnoDB
+PARTITION BY RANGE (i)
+(PARTITION p0 VALUES LESS THAN (100),
+ PARTITION P1 VALUES LESS THAN (200),
+ PARTITION p2 VALUES LESS THAN (300) DATA DIRECTORY = "$MYSQLTEST_VARDIR/partitdata",
+ PARTITION p3 VALUES LESS THAN (400) DATA DIRECTORY = "$MYSQLTEST_VARDIR/partitdata",
+ PARTITION p4 VALUES LESS THAN MAXVALUE);
+INSERT INTO t VALUES (1), (101), (201), (301), (401);
+exec $XTRABACKUP --defaults-file=$MYSQLTEST_VARDIR/my.cnf  --backup  --target-dir=$targetdir;
+exec $XTRABACKUP --prepare --target-dir=$targetdir;
+DROP TABLE t;
+rmdir $MYSQLTEST_VARDIR/partitdata;
+--source include/restart_and_restore.inc
+--enable_result_log
+SELECT * FROM t;
+DROP TABLE t;
+rmdir $targetdir;
+rmdir $MYSQLTEST_VARDIR/partitdata;

storage/xtradb/fil/fil0fil.cc

@@ -4857,7 +4857,7 @@ fil_load_single_table_tablespace(
 
 
 	/* Check for a link file which locates a remote tablespace. */
-	remote.success = fil_open_linked_file(
+	remote.success = (IS_XTRABACKUP() && !srv_backup_mode) ? 0 : fil_open_linked_file(
 		tablename, &remote.filepath, &remote.file, FALSE);
 
 	/* Read the first page of the remote tablespace */