MDEV-15384 buf_flush_LRU_list_batch() always reports n->flushed=0, n->evicted=0

MDEV-14545 Backup fails due to MLOG_INDEX_LOAD record

- Changed the unsupported_redo test case to avoid checkpoint
- Inserting more rows in purge_secondary test case to display evict monitor.

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

@@ -147,6 +147,7 @@ INSERT INTO t1 (a) SELECT NULL FROM t1;
 INSERT INTO t1 (a) SELECT NULL FROM t1;
 INSERT INTO t1 (a) SELECT NULL FROM t1;
 INSERT INTO t1 (a) SELECT NULL FROM t1;
+INSERT INTO t1 (a) SELECT NULL FROM t1;
 SELECT NAME, SUBSYSTEM FROM INFORMATION_SCHEMA.INNODB_METRICS
 WHERE NAME="buffer_LRU_batch_evict_total_pages" AND COUNT > 0;
 NAME	SUBSYSTEM

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

@@ -130,6 +130,7 @@ INSERT INTO t1 (a) SELECT NULL FROM t1;
 INSERT INTO t1 (a) SELECT NULL FROM t1;
 INSERT INTO t1 (a) SELECT NULL FROM t1;
 INSERT INTO t1 (a) SELECT NULL FROM t1;
+INSERT INTO t1 (a) SELECT NULL FROM t1;
 
 SELECT NAME, SUBSYSTEM FROM INFORMATION_SCHEMA.INNODB_METRICS
 WHERE NAME="buffer_LRU_batch_evict_total_pages" AND COUNT > 0;

mysql-test/suite/mariabackup/unsupported_redo.result

@@ -6,20 +6,23 @@ call mtr.add_suppression("InnoDB: Ignoring tablespace for `test`\\.`t21` because
 call mtr.add_suppression("InnoDB: Cannot open datafile for read-only: ");
 call mtr.add_suppression("Table .* in the InnoDB data dictionary has tablespace id .*, but tablespace with that id or name does not exist");
 CREATE TABLE t1(i INT PRIMARY KEY auto_increment, a int) ENGINE INNODB;
-alter table t1 FORCE, algorithm=inplace;
+SET GLOBAL INNODB_FAST_SHUTDOWN = 0;
+ALTER TABLE t1 FORCE, ALGORITHM=INPLACE;
 # Fails during full backup
 DROP TABLE t1;
 CREATE TABLE t1(i INT PRIMARY KEY auto_increment, a int) ENGINE INNODB;
 INSERT INTO t1(a) select 1 union select 2 union select 3;
 # Create full backup , modify table, then fails during creation of
 #		incremental/differential backup
-alter table t1 force, algorithm=inplace;
-drop table t1;
+SET GLOBAL INNODB_FAST_SHUTDOWN = 0;
+ALTER TABLE t1 FORCE, ALGORITHM=INPLACE;
+DROP TABLE t1;
 CREATE TABLE t1(i INT) ENGINE INNODB;
 INSERT INTO t1 VALUES(1);
 CREATE TABLE t21(i INT) ENGINE INNODB;
 INSERT INTO t21 VALUES(1);
 CREATE TABLE t2(i int) ENGINE INNODB;
+SET GLOBAL INNODB_FAST_SHUTDOWN = 0;
 ALTER TABLE t21 FORCE, ALGORITHM=INPLACE;
 # Create partial backup (excluding table t21), Ignore the
 # unsupported redo log for the table t21.

mysql-test/suite/mariabackup/unsupported_redo.test

@@ -11,7 +11,11 @@ let $basedir=$MYSQLTEST_VARDIR/tmp/backup;
 let $incremental_dir=$MYSQLTEST_VARDIR/tmp/backup_inc1;
 
 CREATE TABLE t1(i INT PRIMARY KEY auto_increment, a int) ENGINE INNODB;
-alter table t1 FORCE, algorithm=inplace;
+
+SET GLOBAL INNODB_FAST_SHUTDOWN = 0;
+--source include/restart_mysqld.inc
+
+ALTER TABLE t1 FORCE, ALGORITHM=INPLACE;
 
 # Below mariabackup operation may complete successfully if checkpoint happens
 # after the alter table command.
@@ -35,14 +39,16 @@ INSERT INTO t1(a) select 1 union select 2 union select 3;
 exec $XTRABACKUP --defaults-file=$MYSQLTEST_VARDIR/my.cnf  --backup --target-dir=$basedir;
 --enable_result_log
 
-alter table t1 force, algorithm=inplace;
+SET GLOBAL INNODB_FAST_SHUTDOWN = 0;
+--source include/restart_mysqld.inc
+ALTER TABLE t1 FORCE, ALGORITHM=INPLACE;
 
 --disable_result_log
 --error 1
 exec $XTRABACKUP --defaults-file=$MYSQLTEST_VARDIR/my.cnf  --backup --target-dir=$incremental_dir --incremental-basedir=$basedir;
 --enable_result_log
 
-drop table t1;
+DROP TABLE t1;
 rmdir $basedir;
 rmdir $incremental_dir;
 
@@ -55,6 +61,9 @@ let $MYSQLD_DATADIR= `select @@datadir`;
 let $targetdir=$MYSQLTEST_VARDIR/tmp/bk;
 
 CREATE TABLE t2(i int) ENGINE INNODB;
+
+SET GLOBAL INNODB_FAST_SHUTDOWN = 0;
+--source include/restart_mysqld.inc
 ALTER TABLE t21 FORCE, ALGORITHM=INPLACE;
 
 --echo # Create partial backup (excluding table t21), Ignore the