MDEV-24792 Assertion `!newest_lsn || fil_page_get_type(page)' failed upon...

MDEV-24792 Assertion `!newest_lsn || fil_page_get_type(page)' failed upon MariaBackup prepare in buf_flush_init_for_writing with innodb_log_optimize_ddl=off

fsp_free_page() writes MLOG_INIT_FREE_PAGE, but does not update page
type. But fil_crypt_rotate_page() checks the type to understand if the
page is freshly initialized, and writes dummy record(updates space id)
to force rotation during recovery. This dummy record causes assertion
crash when the page is flushed after recovery, as it's supposed
that pages LSN is 0 for freshly initialized pages.

The bug is similiar to MDEV-24695, the difference is that in 10.5 the
assertion crashes during log record applying, but in 10.4 it crashes
during page flushing.

The fix could be in marking page as freed and not writing dummy record
during keys rotation procedure for such marked pages. But
bpage->file_page_was_freed is not consistent enough for release builds in
10.4, and the issue is fixed in 10.5 and does not exist in 10.[23] as
MLOG_INIT_FREE_PAGE was introduced since 10.4.

So the better solution is just to relax the assertion and implement some
additional property for freshly allocated pages, and check this property
during pages flushing.

The test is copied from MDEV-24695, the only change is in forcing pages
flushing after each server start to cause crash in non-fixed code.

There is no need to merge it to 10.5+, as the bug is already fixed by
MDEV-24695.

mysql-test/suite/encryption/r/innodb_encrypt_freed.result

+SHOW VARIABLES LIKE 'innodb_encrypt%';
+Variable_name	Value
+innodb_encrypt_log	ON
+innodb_encrypt_tables	ON
+innodb_encrypt_temporary_tables	OFF
+innodb_encryption_rotate_key_age	1
+innodb_encryption_rotation_iops	100
+innodb_encryption_threads	1
+SET GLOBAL innodb_encrypt_tables = ON;
+CREATE TABLE t1(f1 BIGINT PRIMARY KEY, f2 int not null,
+f3 int not null, index(f1), index idx_1(f2),
+index(f2, f3)) ENGINE=InnoDB;
+# Wait max 10 min for key encryption threads to encrypt all spaces
+SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
+NAME
+innodb_system
+mysql/innodb_index_stats
+mysql/innodb_table_stats
+mysql/transaction_registry
+test/t1
+CREATE TABLE t2 (f1 int not null)engine=innodb;
+# restart: --debug=d,ib_log_checkpoint_avoid
+SET GLOBAL innodb_log_checkpoint_now=TRUE;
+connect con1,localhost,root,,,;
+begin;
+insert into t2 values(1);
+connection default;
+set global innodb_encrypt_tables = OFF;
+# Wait max 10 min for key encryption threads to decrypt all spaces
+SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION = 0;
+NAME
+innodb_system
+mysql/innodb_index_stats
+mysql/innodb_table_stats
+mysql/transaction_registry
+test/t1
+test/t2
+alter table t1 drop index idx_1;
+set global innodb_encrypt_tables = ON;
+# Wait max 10 min for key encryption threads to encrypt all spaces
+SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
+NAME
+innodb_system
+mysql/innodb_index_stats
+mysql/innodb_table_stats
+mysql/transaction_registry
+test/t1
+test/t2
+disconnect con1;
+# restart: --debug=d,ib_log_checkpoint_avoid
+SET GLOBAL innodb_log_checkpoint_now=TRUE;
+drop table t1, t2;
+CREATE TABLE t1(f1 BIGINT PRIMARY KEY, f2 int not null,
+f3 int not null, index(f1), index idx_1(f2),
+index(f2, f3)) ENGINE=InnoDB;
+# Wait max 10 min for key encryption threads to encrypt all spaces
+SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
+NAME
+innodb_system
+mysql/innodb_index_stats
+mysql/innodb_table_stats
+mysql/transaction_registry
+test/t1
+CREATE TABLE t2 (f1 int not null)engine=innodb;
+# restart: --debug=d,ib_log_checkpoint_avoid
+SET GLOBAL innodb_log_checkpoint_now=TRUE;
+connect con1,localhost,root,,,;
+begin;
+insert into t2 values(1);
+connection default;
+set global innodb_encrypt_tables = OFF;
+# Wait max 10 min for key encryption threads to decrypt all spaces
+SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION = 0;
+NAME
+innodb_system
+mysql/innodb_index_stats
+mysql/innodb_table_stats
+mysql/transaction_registry
+test/t1
+test/t2
+alter table t1 drop index idx_1;
+disconnect con1;
+# restart: --debug=d,ib_log_checkpoint_avoid
+SET GLOBAL innodb_log_checkpoint_now=TRUE;
+connect con1,localhost,root,,,;
+begin;
+insert into t2 values(1);
+connection default;
+set global innodb_encrypt_tables = ON;
+# Wait max 10 min for key encryption threads to encrypt all spaces
+SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
+NAME
+innodb_system
+mysql/innodb_index_stats
+mysql/innodb_table_stats
+mysql/transaction_registry
+test/t1
+test/t2
+disconnect con1;
+drop table t2, t1;

mysql-test/suite/encryption/t/innodb_encrypt_freed.opt

+--innodb-encrypt-tables
+--innodb-encrypt-log
+--innodb-encryption-threads=1
+--innodb-tablespaces-encryption
+--innodb-log-optimize-ddl=OFF

mysql-test/suite/encryption/t/innodb_encrypt_freed.test

+--source include/have_innodb.inc
+--source include/have_example_key_management_plugin.inc
+--source include/have_debug.inc
+--source include/not_embedded.inc
+
+SHOW VARIABLES LIKE 'innodb_encrypt%';
+
+SET GLOBAL innodb_encrypt_tables = ON;
+
+CREATE TABLE t1(f1 BIGINT PRIMARY KEY, f2 int not null,
+		f3 int not null, index(f1), index idx_1(f2),
+		index(f2, f3)) ENGINE=InnoDB;
+--let $tables_count= `select count(*) + 1 from information_schema.tables where engine = 'InnoDB'`
+
+--echo # Wait max 10 min for key encryption threads to encrypt all spaces
+--let $wait_timeout= 600
+--let $wait_condition=SELECT COUNT(*) >= $tables_count FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
+--source include/wait_condition.inc
+--sorted_result
+SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
+
+CREATE TABLE t2 (f1 int not null)engine=innodb;
+let $restart_parameters="--debug=d,ib_log_checkpoint_avoid";
+--source include/restart_mysqld.inc
+SET GLOBAL innodb_log_checkpoint_now=TRUE;
+
+# Stop the purge
+connect(con1,localhost,root,,,);
+begin;
+insert into t2 values(1);
+
+connection default;
+
+--let $tables_count= `select count(*) + 1 from information_schema.tables where engine = 'InnoDB'`
+set global innodb_encrypt_tables = OFF;
+
+--echo # Wait max 10 min for key encryption threads to decrypt all spaces
+--let $wait_timeout= 600
+--let $wait_condition=SELECT COUNT(*) >= $tables_count FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION = 0;
+--source include/wait_condition.inc
+--sorted_result
+SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION = 0;
+
+# Free the index `idx_1`
+alter table t1 drop index idx_1;
+
+set global innodb_encrypt_tables = ON;
+
+--echo # Wait max 10 min for key encryption threads to encrypt all spaces
+--let $wait_timeout= 600
+--let $wait_condition=SELECT COUNT(*) >= $tables_count FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
+--source include/wait_condition.inc
+--sorted_result
+SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
+
+disconnect con1;
+let $shutdown_timeout=0;
+--source include/restart_mysqld.inc
+SET GLOBAL innodb_log_checkpoint_now=TRUE;
+
+drop table t1, t2;
+
+#
+#
+CREATE TABLE t1(f1 BIGINT PRIMARY KEY, f2 int not null,
+		f3 int not null, index(f1), index idx_1(f2),
+		index(f2, f3)) ENGINE=InnoDB;
+--let $tables_count= `select count(*) + 1 from information_schema.tables where engine = 'InnoDB'`
+
+--echo # Wait max 10 min for key encryption threads to encrypt all spaces
+--let $wait_timeout= 600
+--let $wait_condition=SELECT COUNT(*) >= $tables_count FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
+--source include/wait_condition.inc
+--sorted_result
+SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
+
+CREATE TABLE t2 (f1 int not null)engine=innodb;
+--source include/restart_mysqld.inc
+SET GLOBAL innodb_log_checkpoint_now=TRUE;
+
+# Stop the purge
+connect(con1,localhost,root,,,);
+begin;
+insert into t2 values(1);
+
+connection default;
+
+--let $tables_count= `select count(*) + 1 from information_schema.tables where engine = 'InnoDB'`
+set global innodb_encrypt_tables = OFF;
+
+--echo # Wait max 10 min for key encryption threads to decrypt all spaces
+--let $wait_timeout= 600
+--let $wait_condition=SELECT COUNT(*) >= $tables_count FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION = 0;
+--source include/wait_condition.inc
+--sorted_result
+SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION = 0;
+
+# Free the index `idx_1`
+alter table t1 drop index idx_1;
+
+disconnect con1;
+--source include/restart_mysqld.inc
+SET GLOBAL innodb_log_checkpoint_now=TRUE;
+
+# Stop the purge
+connect(con1,localhost,root,,,);
+begin;
+insert into t2 values(1);
+
+connection default;
+set global innodb_encrypt_tables = ON;
+
+--echo # Wait max 10 min for key encryption threads to encrypt all spaces
+--let $wait_timeout= 600
+--let $wait_condition=SELECT COUNT(*) >= $tables_count FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
+--source include/wait_condition.inc
+--sorted_result
+SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
+
+disconnect con1;
+drop table t2, t1;

mysql-test/suite/encryption/t/innodb_encryption.test

@@ -14,7 +14,7 @@ SHOW VARIABLES LIKE 'innodb_encrypt%';
 
 SET GLOBAL innodb_encrypt_tables = ON;
 
---let $tables_count= `select count(*) + 1 from information_schema.tables where engine = 'InnoDB'`
+--let $tables_count= `select count(*) + @@global.innodb_undo_tablespaces + 1 from information_schema.tables where engine = 'InnoDB'`
 
 --echo # Wait max 10 min for key encryption threads to encrypt all spaces
 --let $wait_timeout= 600

storage/innobase/buf/buf0buf.cc

@@ -5713,6 +5713,9 @@ buf_page_create(
 
 	memset(frame + FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION, 0, 8);
 	memset(frame + FIL_PAGE_LSN, 0, 8);
+	/* mark page as just allocated for check in
+	buf_flush_init_for_writing() */
+	ut_d(memset(frame + FIL_PAGE_SPACE_OR_CHKSUM, 0, 4));
 
 #if defined UNIV_DEBUG || defined UNIV_BUF_DEBUG
 	ut_a(++buf_dbg_counter % 5771 || buf_validate());

storage/innobase/buf/buf0flu.cc

@@ -783,7 +783,17 @@ buf_flush_init_for_writing(
 	      || &block->page.zip == page_zip_);
 	ut_ad(!block || newest_lsn);
 	ut_ad(page);
-	ut_ad(!newest_lsn || fil_page_get_type(page));
+	/* Encryption key rotation procedure can write dummy log records to
+	update page's space id, what causes page LSN update, and we need some
+	additional check during recovery to be sure the page is freshly
+	allocated, see buf_page_create() to find such patterns */
+	ut_ad(fil_page_get_type(page)
+	      || (!newest_lsn
+		  || (mach_read_from_4(page + FIL_PAGE_SPACE_ID)
+			      == block->page.id.space()
+		      && mach_read_from_4(page + FIL_PAGE_PREV) == 0xffffffff
+		      && mach_read_from_4(page + FIL_PAGE_NEXT) == 0xffffffff
+		      && !mach_read_from_4(page + FIL_PAGE_SPACE_OR_CHKSUM))));
 
 	if (page_zip_) {
 		page_zip_des_t*	page_zip;