maria-developers team mailing list archive

[Sergey Vojtovich <svoj@xxxxxxxxxxx>]

Hi Sergei,

On Fri, Jun 16, 2017 at 02:28:55PM +0200, Sergei Golubchik wrote:
> Hi, Sergey!
> 
> On Jun 16, Sergey Vojtovich wrote:
> > revision-id: 056bab0880544d91ea67d18fe8db65b4f6625482 (mariadb-10.1.24-22-g056bab0)
> > parent(s): 58f87a41bd8de7370cc05c41977fadc685826c9e
> > committer: Sergey Vojtovich
> > timestamp: 2017-06-16 15:47:46 +0400
> > message:
> > 
> > MDEV-12620 - set lock_wait_timeout = 1;flush tables with read lock;
> >              lock not released after timeout
> > 
> > Release GRL if FLUSH TABLES phase failed.
> > 
> > diff --git a/mysql-test/t/mdl_sync.test b/mysql-test/t/mdl_sync.test
> > index 8e80978..c479c2a 100644
> > --- a/mysql-test/t/mdl_sync.test
> > +++ b/mysql-test/t/mdl_sync.test
> > @@ -4806,6 +4806,30 @@ disconnect con2;
> >  disconnect con3;
> >  
> > +--echo #
> > +--echo # MDEV-12620 - set lock_wait_timeout = 1;flush tables with read lock;
> > +--echo #              lock not released after timeout
> > +--echo #
> > +CREATE TABLE t1(a INT) ENGINE=InnoDB;
> > +SET debug_sync='open_tables_after_open_and_process_table SIGNAL ready WAIT_FOR go';
> > +send SELECT * FROM t1;
> > +
> > +connect (con1,localhost,root,,);
> > +SET debug_sync='now WAIT_FOR ready';
> > +# lock_wait_timeout should be 0 in 10.3, so that we don't have to wait at all
> 
> what's special in 10.3?
Rev. 8026cd6202bd252dc9baac31d6c8bc39653bd637:
...
    Valid range of lock_wait_timeout and innodb_lock_wait_timeout was extended so
    that 0 is acceptable value (means no wait).
...

> 
> > +SET lock_wait_timeout=1;
> > +--error ER_LOCK_WAIT_TIMEOUT
> > +FLUSH TABLES WITH READ LOCK;
> > +SET debug_sync='now SIGNAL go';
> > +
> > +connection default;
> > +reap;
> > +SET debug_sync='RESET';
> > +DROP TABLE t1;
> 
> What should happen without a bug fix?
> DROP TABLE hangs?
Yes, DROP TABLE hangs.

> 
> > +
> > +disconnect con1;
> > +
> >  # Check that all connections opened by test cases in this file are really
> >  # gone so execution of other tests won't be affected by their presence.
> >  --source include/wait_until_count_sessions.inc
> > diff --git a/sql/sql_reload.cc b/sql/sql_reload.cc
> > index 376dfeb..d68ce96 100644
> > --- a/sql/sql_reload.cc
> > +++ b/sql/sql_reload.cc
> > @@ -253,7 +253,8 @@ bool reload_acl_and_cache(THD *thd, unsigned long long options,
> >            NOTE: my_error() has been already called by reopen_tables() within
> >            close_cached_tables().
> >          */
> > -        result= 1;
> > +        thd->global_read_lock.unlock_global_read_lock(thd);
> > +        return 1;
> >        }
> 
> Sure. Looks correct.
> 
> Regards,
> Sergei
> Chief Architect MariaDB
> and security@xxxxxxxxxxx

Thanks,
Sergey