Commit 77b7a862 authored by unknown's avatar unknown
Browse files

WL#3602 (SET GLOBAL READONLY) 

Bug#11733 (COMMITs should not happen if read-only is set)
Bug#22009 (Can write to a read-only server under some circumstances)

See the work log for details

The change consist of
a) acquiring the global read lock in SET GLOBAL READONLY
b) honoring opt_readonly in ha_commit_trans(),
c) honoring opt_readonly in mysql_lock_tables().

a) takes care of the server stability,
b) makes the transactional tables safe (Bug 11733)
c) makes the non transactional tables safe (Bug 22009)


mysql-test/r/read_only.result:
  WL#3602 (SET GLOBAL READONLY)
mysql-test/t/read_only.test:
  WL#3602 (SET GLOBAL READONLY)
sql/handler.cc:
  WL#3602 (SET GLOBAL READONLY)
sql/lock.cc:
  WL#3602 (SET GLOBAL READONLY)
sql/set_var.cc:
  WL#3602 (SET GLOBAL READONLY)
sql/set_var.h:
  WL#3602 (SET GLOBAL READONLY)
mysql-test/r/read_only_innodb.result:
  WL#3602 (SET GLOBAL READONLY)
mysql-test/t/read_only_innodb.test:
  WL#3602 (SET GLOBAL READONLY)
parent 78be2cdc

mysql-test/r/read_only.result

+51 −1
Original line number Diff line number Diff line
@@ -39,6 +39,56 @@ delete t1 from t1,t3 where t1.a=t3.a; 
drop table t1;

insert into t1 values(1);

ERROR HY000: The MySQL server is running with the --read-only option so it cannot execute this statement

set global read_only=0;

lock table t1 write;

lock table t2 write;

set global read_only=1;

ERROR HY000: Can't execute the given command because you have active locked tables or an active transaction

unlock tables ;

set global read_only=1;

select @@global.read_only;

@@global.read_only

0

unlock tables ;

select @@global.read_only;

@@global.read_only

1

set global read_only=0;

lock table t1 read;

lock table t2 read;

set global read_only=1;

ERROR HY000: Can't execute the given command because you have active locked tables or an active transaction

unlock tables ;

set global read_only=1;

select @@global.read_only;

@@global.read_only

0

unlock tables ;

select @@global.read_only;

@@global.read_only

1

set global read_only=0;

BEGIN;

BEGIN;

set global read_only=1;

ERROR HY000: Can't execute the given command because you have active locked tables or an active transaction

ROLLBACK;

set global read_only=1;

select @@global.read_only;

@@global.read_only

1

ROLLBACK;

set global read_only=0;

flush tables with read lock;

set global read_only=1;

unlock tables;

set global read_only=0;

flush tables with read lock;

set global read_only=1;

select @@global.read_only;

@@global.read_only

1

unlock tables;

set global read_only=0;

drop table t1,t2;

drop user test@localhost;
 
set global read_only=0;

mysql-test/r/read_only_innodb.result

0 → 100644
+18 −0
Original line number Diff line number Diff line 
DROP TABLE IF EXISTS table_11733 ;

grant CREATE, SELECT, DROP on *.* to test@localhost;

set global read_only=0;

create table table_11733 (a int) engine=InnoDb;

BEGIN;

insert into table_11733 values(11733);

set global read_only=1;

select @@global.read_only;

@@global.read_only

1

select * from table_11733 ;

a

11733

COMMIT;

ERROR HY000: The MySQL server is running with the --read-only option so it cannot execute this statement

set global read_only=0;

drop table table_11733 ;

drop user test@localhost;

mysql-test/t/read_only.test

+108 −2
Original line number Diff line number Diff line
@@ -101,8 +101,114 @@ drop table t1; 
--error 1290

insert into t1 values(1);



#

# BUG#11733: COMMITs should not happen if read-only is set

#



# LOCK TABLE ... WRITE / READ_ONLY

# - is an error in the same connection

# - is ok in a different connection



connection default;

drop table t1,t2;

drop user test@localhost;

set global read_only=0;

lock table t1 write;



connection con1;

lock table t2 write;



connection default;

--error ER_LOCK_OR_ACTIVE_TRANSACTION

set global read_only=1;

unlock tables ;

# The following call blocks until con1 releases the write lock.

# Blocking is expected.

send set global read_only=1;



connection con1;

--sleep 1

select @@global.read_only;

unlock tables ;

--sleep 1

select @@global.read_only;



connection default;

reap;



# LOCK TABLE ... READ / READ_ONLY

# - is an error in the same connection

# - is ok in a different connection



connection default;

set global read_only=0;

lock table t1 read;



connection con1;

lock table t2 read;



connection default;

--error ER_LOCK_OR_ACTIVE_TRANSACTION

set global read_only=1;

unlock tables ;

# The following call blocks until con1 releases the read lock.

# Blocking is a limitation, and could be improved.

send set global read_only=1;



connection con1;

--sleep 1

select @@global.read_only;

unlock tables ;

--sleep 1

select @@global.read_only;



connection default;

reap;



# pending transaction / READ_ONLY

# - is an error in the same connection

# - is ok in a different connection



connection default;

set global read_only=0;

BEGIN;



connection con1;

BEGIN;



connection default;

--error ER_LOCK_OR_ACTIVE_TRANSACTION

set global read_only=1;

ROLLBACK;

set global read_only=1;



connection con1;

select @@global.read_only;

ROLLBACK;



# Verify that FLUSH TABLES WITH READ LOCK do not block READ_ONLY

# - in the same SUPER connection

# - in another SUPER connection



connection default;

set global read_only=0;

flush tables with read lock;

set global read_only=1;

unlock tables;



connect (root2,localhost,root,,test);



connection default;

set global read_only=0;

flush tables with read lock;



connection root2;

set global read_only=1;



connection default;

select @@global.read_only;

unlock tables;



# Cleanup

connection default;

set global read_only=0;

drop table t1,t2;

drop user test@localhost;

mysql-test/t/read_only_innodb.test

0 → 100644
+43 −0
Original line number Diff line number Diff line 
# should work with embedded server after mysqltest is fixed

-- source include/not_embedded.inc

-- source include/have_innodb.inc



#

# BUG#11733: COMMITs should not happen if read-only is set

#



--disable_warnings

DROP TABLE IF EXISTS table_11733 ;

--enable_warnings



# READ_ONLY does nothing to SUPER users

# so we use a non-SUPER one:



grant CREATE, SELECT, DROP on *.* to test@localhost;



connect (con1,localhost,test,,test);



connection default;

set global read_only=0;



# Any transactional engine will do

create table table_11733 (a int) engine=InnoDb;



connection con1;

BEGIN;

insert into table_11733 values(11733);



connection default;

set global read_only=1;



connection con1;

select @@global.read_only;

select * from table_11733 ;

-- error ER_OPTION_PREVENTS_STATEMENT

COMMIT;



connection default;

set global read_only=0;

drop table table_11733 ;

drop user test@localhost;

sql/handler.cc

+9 −0
Original line number Diff line number Diff line
@@ -692,6 +692,15 @@ int ha_commit_trans(THD *thd, bool all) 
      ha_rollback_trans(thd, all);

      DBUG_RETURN(1);

    }



    if (is_real_trans && opt_readonly)

    {

      my_error(ER_OPTION_PREVENTS_STATEMENT, MYF(0), "--read-only");

      ha_rollback_trans(thd, all);

      error= 1;

      goto end;

    }



    DBUG_EXECUTE_IF("crash_commit_before", abort(););



    /* Close all cursors that can not survive COMMIT */