From 65c5e8dcbf829c1e554b44363c4d264202514513 Mon Sep 17 00:00:00 2001 From: Alexander Nozdrin Date: Tue, 31 Aug 2010 13:52:56 +0400 Subject: Bug#27480 (Extend CREATE TEMPORARY TABLES privilege to allow temp table operations) -- prerequisite patch #2. Introduce a new form of find_temporary_table() function: find_temporary_table() by a table key. It will be used in further patches. Replace find_temporary_table(table_list->db, table_list->name) by more appropiate find_temporary_table(table_list) across the codebase. --- sql/sql_trigger.cc | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'sql/sql_trigger.cc') diff --git a/sql/sql_trigger.cc b/sql/sql_trigger.cc index b81461e8371..c1405015365 100644 --- a/sql/sql_trigger.cc +++ b/sql/sql_trigger.cc @@ -458,7 +458,7 @@ bool mysql_create_or_drop_trigger(THD *thd, TABLE_LIST *tables, bool create) DBUG_ASSERT(tables->next_global == 0); /* We do not allow creation of triggers on temporary tables. */ - if (create && find_temporary_table(thd, tables->db, tables->table_name)) + if (create && find_temporary_table(thd, tables)) { my_error(ER_TRG_ON_VIEW_OR_TEMP_TABLE, MYF(0), tables->alias); goto end; -- cgit v1.2.1 From a302953bf77cceb0fec5097b7a5a7a937b8157c3 Mon Sep 17 00:00:00 2001 From: Jon Olav Hauglid Date: Thu, 16 Sep 2010 11:11:13 +0200 Subject: Bug #56595 RENAME TABLE causes assert on OS X The problem was that RENAME TABLE caused an assert if the system variable lower_case_table_names was 2 (default on Mac OS X) and the old table name was given in upper case. This caused lowercase_table2.test to fail. The assert checks that an exclusive metadata lock is held by the connection trying to do RENAME TABLE - specificially during updates of table triggers. The assert was triggered since the check is case sensitive and the lock was held on the normalized (lower case) version of the table name. This patch fixes the problem by making sure a normalized version of the table name is used for the metadata lock check, while using a non-normalized version of the table name for the rename of trigger files. The same is done for ALTER TABLE ... RENAME. Regression testing for the bug itself is already covered by lowercase_table2.test. Additional coverage added to lowercase_fs_off.test. --- sql/sql_trigger.cc | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'sql/sql_trigger.cc') diff --git a/sql/sql_trigger.cc b/sql/sql_trigger.cc index c1405015365..392343eb9a3 100644 --- a/sql/sql_trigger.cc +++ b/sql/sql_trigger.cc @@ -1874,6 +1874,7 @@ Table_triggers_list::change_table_name_in_trignames(const char *old_db_name, @param[in,out] thd Thread context @param[in] db Old database of subject table + @param[in] old_alias Old alias of subject table @param[in] old_table Old name of subject table @param[in] new_db New database for subject table @param[in] new_table New name of subject table @@ -1890,6 +1891,7 @@ Table_triggers_list::change_table_name_in_trignames(const char *old_db_name, */ bool Table_triggers_list::change_table_name(THD *thd, const char *db, + const char *old_alias, const char *old_table, const char *new_db, const char *new_table) @@ -1911,7 +1913,7 @@ bool Table_triggers_list::change_table_name(THD *thd, const char *db, MDL_EXCLUSIVE)); DBUG_ASSERT(my_strcasecmp(table_alias_charset, db, new_db) || - my_strcasecmp(table_alias_charset, old_table, new_table)); + my_strcasecmp(table_alias_charset, old_alias, new_table)); if (Table_triggers_list::check_n_load(thd, db, old_table, &table, TRUE)) { @@ -1920,7 +1922,7 @@ bool Table_triggers_list::change_table_name(THD *thd, const char *db, } if (table.triggers) { - LEX_STRING old_table_name= { (char *) old_table, strlen(old_table) }; + LEX_STRING old_table_name= { (char *) old_alias, strlen(old_alias) }; LEX_STRING new_table_name= { (char *) new_table, strlen(new_table) }; /* Since triggers should be in the same schema as their subject tables -- cgit v1.2.1 From 6bf6272fdabf78e62f04fbcafb1d1e7dee2b27c2 Mon Sep 17 00:00:00 2001 From: Dmitry Lenev Date: Thu, 11 Nov 2010 20:11:05 +0300 Subject: Patch that refactors global read lock implementation and fixes bug #57006 "Deadlock between HANDLER and FLUSH TABLES WITH READ LOCK" and bug #54673 "It takes too long to get readlock for 'FLUSH TABLES WITH READ LOCK'". The first bug manifested itself as a deadlock which occurred when a connection, which had some table open through HANDLER statement, tried to update some data through DML statement while another connection tried to execute FLUSH TABLES WITH READ LOCK concurrently. What happened was that FTWRL in the second connection managed to perform first step of GRL acquisition and thus blocked all upcoming DML. After that it started to wait for table open through HANDLER statement to be flushed. When the first connection tried to execute DML it has started to wait for GRL/the second connection creating deadlock. The second bug manifested itself as starvation of FLUSH TABLES WITH READ LOCK statements in cases when there was a constant stream of concurrent DML statements (in two or more connections). This has happened because requests for protection against GRL which were acquired by DML statements were ignoring presence of pending GRL and thus the latter was starved. This patch solves both these problems by re-implementing GRL using metadata locks. Similar to the old implementation acquisition of GRL in new implementation is two-step. During the first step we block all concurrent DML and DDL statements by acquiring global S metadata lock (each DML and DDL statement acquires global IX lock for its duration). During the second step we block commits by acquiring global S lock in COMMIT namespace (commit code acquires global IX lock in this namespace). Note that unlike in old implementation acquisition of protection against GRL in DML and DDL is semi-automatic. We assume that any statement which should be blocked by GRL will either open and acquires write-lock on tables or acquires metadata locks on objects it is going to modify. For any such statement global IX metadata lock is automatically acquired for its duration. The first problem is solved because waits for GRL become visible to deadlock detector in metadata locking subsystem and thus deadlocks like one in the first bug become impossible. The second problem is solved because global S locks which are used for GRL implementation are given preference over IX locks which are acquired by concurrent DML (and we can switch to fair scheduling in future if needed). Important change: FTWRL/GRL no longer blocks DML and DDL on temporary tables. Before this patch behavior was not consistent in this respect: in some cases DML/DDL statements on temporary tables were blocked while in others they were not. Since the main use cases for FTWRL are various forms of backups and temporary tables are not preserved during backups we have opted for consistently allowing DML/DDL on temporary tables during FTWRL/GRL. Important change: This patch changes thread state names which are used when DML/DDL of FTWRL is waiting for global read lock. It is now either "Waiting for global read lock" or "Waiting for commit lock" depending on the stage on which FTWRL is. Incompatible change: To solve deadlock in events code which was exposed by this patch we have to replace LOCK_event_metadata mutex with metadata locks on events. As result we have to prohibit DDL on events under LOCK TABLES. This patch also adds extensive test coverage for interaction of DML/DDL and FTWRL. Performance of new and old global read lock implementations in sysbench tests were compared. There were no significant difference between new and old implementations. mysql-test/include/check_ftwrl_compatible.inc: Added helper script which allows to check that a statement is compatible with FLUSH TABLES WITH READ LOCK. mysql-test/include/check_ftwrl_incompatible.inc: Added helper script which allows to check that a statement is incompatible with FLUSH TABLES WITH READ LOCK. mysql-test/include/handler.inc: Adjusted test case to the fact that now DROP TABLE closes open HANDLERs for the table to be dropped before checking if there active FTWRL in this connection. mysql-test/include/wait_show_condition.inc: Fixed small error in the timeout message. The correct name of variable used as parameter for this script is "$condition" and not "$wait_condition". mysql-test/r/delayed.result: Added test coverage for scenario which triggered assert in metadata locking subsystem. mysql-test/r/events_2.result: Updated test results after prohibiting event DDL operations under LOCK TABLES. mysql-test/r/flush.result: Added test coverage for bug #57006 "Deadlock between HANDLER and FLUSH TABLES WITH READ LOCK". mysql-test/r/flush_read_lock.result: Added test coverage for various aspects of FLUSH TABLES WITH READ LOCK functionality. mysql-test/r/flush_read_lock_kill.result: Adjusted test case after replacing custom global read lock implementation with one based on metadata locks. Use new debug_sync point. Do not disable concurrent inserts as now InnoDB we always use InnoDB table. mysql-test/r/handler_innodb.result: Adjusted test case to the fact that now DROP TABLE closes open HANDLERs for the table to be dropped before checking if there active FTWRL in this connection. mysql-test/r/handler_myisam.result: Adjusted test case to the fact that now DROP TABLE closes open HANDLERs for the table to be dropped before checking if there active FTWRL in this connection. mysql-test/r/mdl_sync.result: Adjusted test case after replacing custom global read lock implementation with one based on metadata locks. Replaced usage of GRL-specific debug_sync's with appropriate sync points in MDL subsystem. mysql-test/suite/perfschema/r/dml_setup_instruments.result: Updated test results after removing global COND_global_read_lock condition variable. mysql-test/suite/perfschema/r/func_file_io.result: Ensure that this test doesn't affect subsequent tests. At the end of its execution enable back P_S instrumentation which this test disables at some point. mysql-test/suite/perfschema/r/func_mutex.result: Ensure that this test doesn't affect subsequent tests. At the end of its execution enable back P_S instrumentation which this test disables at some point. mysql-test/suite/perfschema/r/global_read_lock.result: Adjusted test case to take into account that new GRL implementation is based on MDL. mysql-test/suite/perfschema/r/server_init.result: Adjusted test case after replacing custom global read lock implementation with one based on MDL and replacing LOCK_event_metadata mutex with metadata lock. mysql-test/suite/perfschema/t/func_file_io.test: Ensure that this test doesn't affect subsequent tests. At the end of its execution enable back P_S instrumentation which this test disables at some point. mysql-test/suite/perfschema/t/func_mutex.test: Ensure that this test doesn't affect subsequent tests. At the end of its execution enable back P_S instrumentation which this test disables at some point. mysql-test/suite/perfschema/t/global_read_lock.test: Adjusted test case to take into account that new GRL implementation is based on MDL. mysql-test/suite/perfschema/t/server_init.test: Adjusted test case after replacing custom global read lock implementation with one based on MDL and replacing LOCK_event_metadata mutex with metadata lock. mysql-test/suite/rpl/r/rpl_tmp_table_and_DDL.result: Updated test results after prohibiting event DDL under LOCK TABLES. mysql-test/t/delayed.test: Added test coverage for scenario which triggered assert in metadata locking subsystem. mysql-test/t/events_2.test: Updated test case after prohibiting event DDL operations under LOCK TABLES. mysql-test/t/flush.test: Added test coverage for bug #57006 "Deadlock between HANDLER and FLUSH TABLES WITH READ LOCK". mysql-test/t/flush_block_commit.test: Adjusted test case after changing thread state name which is used when COMMIT waits for FLUSH TABLES WITH READ LOCK from "Waiting for release of readlock" to "Waiting for commit lock". mysql-test/t/flush_block_commit_notembedded.test: Adjusted test case after changing thread state name which is used when DML waits for FLUSH TABLES WITH READ LOCK. Now we use "Waiting for global read lock" in this case. mysql-test/t/flush_read_lock.test: Added test coverage for various aspects of FLUSH TABLES WITH READ LOCK functionality. mysql-test/t/flush_read_lock_kill-master.opt: We no longer need to use make_global_read_lock_block_commit_loop debug tag in this test. Instead we rely on an appropriate debug_sync point in MDL code. mysql-test/t/flush_read_lock_kill.test: Adjusted test case after replacing custom global read lock implementation with one based on metadata locks. Use new debug_sync point. Do not disable concurrent inserts as now InnoDB we always use InnoDB table. mysql-test/t/lock_multi.test: Adjusted test case after changing thread state names which are used when DML or DDL waits for FLUSH TABLES WITH READ LOCK to "Waiting for global read lock". mysql-test/t/mdl_sync.test: Adjusted test case after replacing custom global read lock implementation with one based on metadata locks. Replaced usage of GRL-specific debug_sync's with appropriate sync points in MDL subsystem. Updated thread state names which are used when DDL waits for FTWRL. mysql-test/t/trigger_notembedded.test: Adjusted test case after changing thread state names which are used when DML or DDL waits for FLUSH TABLES WITH READ LOCK to "Waiting for global read lock". sql/event_data_objects.cc: Removed Event_queue_element::status/last_executed_changed members and Event_queue_element::update_timing_fields() method. We no longer use this class for updating mysql.events once event is chosen for execution. Accesses to instances of this class in scheduler thread require protection by Event_queue::LOCK_event_queue mutex and we try to avoid updating table while holding this lock. sql/event_data_objects.h: Removed Event_queue_element::status/last_executed_changed members and Event_queue_element::update_timing_fields() method. We no longer use this class for updating mysql.events once event is chosen for execution. Accesses to instances of this class in scheduler thread require protection by Event_queue::LOCK_event_queue mutex and we try to avoid updating table while holding this lock. sql/event_db_repository.cc: - Changed Event_db_repository methods to not release all metadata locks once they are done updating mysql.events table. This allows to keep metadata lock protecting against GRL and lock protecting particular event around until corresponding DDL statement is written to the binary log. - Removed logic for conditional update of "status" and "last_executed" fields from update_timing_fields_for_event() method. In the only case when this method is called now "last_executed" is always modified and tracking change of "status" is too much hassle. sql/event_db_repository.h: Removed logic for conditional update of "status" and "last_executed" fields from Event_db_repository:: update_timing_fields_for_event() method. In the only case when this method is called now "last_executed" is always modified and tracking change of "status" field is too much hassle. sql/event_queue.cc: Changed event scheduler code not to update mysql.events table while holding Event_queue::LOCK_event_queue mutex. Doing so led to a deadlock with a new GRL implementation. This deadlock didn't occur with old implementation due to fact that code acquiring protection against GRL ignored pending GRL requests (which lead to GRL starvation). One of goals of new implementation is to disallow GRL starvation and so we have to solve problem with this deadlock in a different way. sql/events.cc: Changed methods of Events class to acquire protection against GRL while perfoming DDL statement and keep it until statement is written to the binary log. Unfortunately this step together with new GRL implementation exposed deadlock involving Events::LOCK_event_metadata and GRL. To solve it Events::LOCK_event_metadata mutex was replaced with a metadata lock on event. As a side-effect events DDL has to be prohibited under LOCK TABLES even in cases when mysql.events table was explicitly locked for write. sql/events.h: Replaced Events::LOCK_event_metadata mutex with a metadata lock on event. sql/ha_ndbcluster.cc: Updated code after replacing custom global read lock implementation with one based on MDL. Since MDL subsystem should now be able to detect deadlocks involving metadata locks and GRL there is no need for special handling of active GRL. sql/handler.cc: Replaced custom implementation of global read lock with one based on metadata locks. Consequently when doing commit instead of calling method of Global_read_lock class to acquire protection against GRL we simply acquire IX in COMMIT namespace. sql/lock.cc: Replaced custom implementation of global read lock with one based on metadata locks. This step allows to expose wait for GRL to deadlock detector of MDL subsystem and thus succesfully resolve deadlocks similar to one behind bug #57006 "Deadlock between HANDLER and FLUSH TABLES WITH READ LOCK". It also solves problem with GRL starvation described in bug #54673 "It takes too long to get readlock for 'FLUSH TABLES WITH READ LOCK'" since metadata locks used by GRL give preference to FTWRL statement instead of DML statements (if needed in future this can be changed to fair scheduling). Similar to old implementation of acquisition of GRL is two-step. During the first step we block all concurrent DML and DDL statements by acquiring global S metadata lock (each DML and DDL statement acquires global IX lock for its duration). During the second step we block commits by acquiring global S lock in COMMIT namespace (commit code acquires global IX lock in this namespace). Note that unlike in old implementation acquisition of protection against GRL in DML and DDL is semi-automatic. We assume that any statement which should be blocked by GRL will either open and acquires write-lock on tables or acquires metadata locks on objects it is going to modify. For any such statement global IX metadata lock is automatically acquired for its duration. To support this change: - Global_read_lock::lock/unlock_global_read_lock and make_global_read_lock_block_commit methods were changed accordingly. - Global_read_lock::wait_if_global_read_lock() and start_waiting_global_read_lock() methods were dropped. It is now responsibility of code acquiring metadata locks opening tables to acquire protection against GRL by explicitly taking global IX lock with statement duration. - Global variables, mutex and condition variable used by old implementation was removed. - lock_routine_name() was changed to use statement duration for its global IX lock. It was also renamed to lock_object_name() as it now also used to take metadata locks on events. - Global_read_lock::set_explicit_lock_duration() was added which allows not to release locks used for GRL when leaving prelocked mode. sql/lock.h: - Renamed lock_routine_name() to lock_object_name() and changed its signature to allow its usage for events. - Removed broadcast_refresh() function. It is no longer needed with new GRL implementation. sql/log_event.cc: Release metadata locks with statement duration at the end of processing legacy event for LOAD DATA. This ensures that replication thread processing such event properly releases its protection against global read lock. sql/mdl.cc: Changed MDL subsystem to support new MDL-based implementation of global read lock. Added COMMIT and EVENTS namespaces for metadata locks. Changed thread state name for GLOBAL namespace to "Waiting for global read lock". Optimized MDL_map::find_or_insert() method to avoid taking m_mutex mutex when looking up MDL_lock objects for GLOBAL or COMMIT namespaces. We keep pre-created MDL_lock objects for these namespaces around and simply return pointers to these global objects when needed. Changed MDL_lock/MDL_scoped_lock to properly handle notification of insert delayed handler threads when FTWRL takes global S lock. Introduced concept of lock duration. In addition to locks with transaction duration which work in the way which is similar to how locks worked before (i.e. they are released at the end of transaction), locks with statement and explicit duration were introduced. Locks with statement duration are automatically released at the end of statement. Locks with explicit duration require explicit release and obsolete concept of transactional sentinel. * Changed MDL_request and MDL_ticket classes to support notion of duration. * Changed MDL_context to keep locks with different duration in different lists. Changed code handling ticket list to take this into account. * Changed methods responsible for releasing locks to take into account duration of tickets. Particularly public MDL_context::release_lock() method now only can release tickets with explicit duration (there is still internal method which allows to specify duration). To release locks with statement or transaction duration one have to use release_statement/transactional_locks() methods. * Concept of savepoint for MDL subsystem now has to take into account locks with statement duration. Consequently MDL_savepoint class was introduced and methods working with savepoints were updated accordingly. * Added methods which allow to set duration for one or all locks in the context. sql/mdl.h: Changed MDL subsystem to support new MDL-based implementation of global read lock. Added COMMIT and EVENTS namespaces for metadata locks. Introduced concept of lock duration. In addition to locks with transaction duration which work in the way which is similar to how locks worked before (i.e. they are released at the end of transaction), locks with statement and explicit duration were introduced. Locks with statement duration are automatically released at the end of statement. Locks with explicit duration require explicit release and obsolete concept of transactional sentinel. * Changed MDL_request and MDL_ticket classes to support notion of duration. * Changed MDL_context to keep locks with different duration in different lists. Changed code handling ticket list to take this into account. * Changed methods responsible for releasing locks to take into account duration of tickets. Particularly public MDL_context::release_lock() method now only can release tickets with explicit duration (there is still internal method which allows to specify duration). To release locks with statement or transaction duration one have to use release_statement/transactional_locks() methods. * Concept of savepoint for MDL subsystem now has to take into account locks with statement duration. Consequently MDL_savepoint class was introduced and methods working with savepoints were updated accordingly. * Added methods which allow to set duration for one or all locks in the context. sql/mysqld.cc: Removed global mutex and condition variables which were used by old implementation of GRL. Also we no longer need to initialize Events::LOCK_event_metadata mutex as it was replaced with metadata locks on events. sql/mysqld.h: Removed global variable, mutex and condition variables which were used by old implementation of GRL. sql/rpl_rli.cc: When slave thread closes tables which were open for handling of RBR events ensure that it releases global IX lock which was acquired as protection against GRL. sql/sp.cc: Adjusted code to the new signature of lock_object/routine_name(), to the fact that one now needs specify duration of lock when initializing MDL_request and to the fact that savepoints for MDL subsystem are now represented by MDL_savepoint class. sql/sp_head.cc: Ensure that statements in stored procedures release statement metadata locks and thus release their protectiong against GRL in proper moment in time. Adjusted code to the fact that one now needs specify duration of lock when initializing MDL_request. sql/sql_admin.cc: Adjusted code to the fact that one now needs specify duration of lock when initializing MDL_request. sql/sql_base.cc: - Implemented support for new approach to acquiring protection against global read lock. We no longer acquire such protection explicitly on the basis of statement flags. Instead we always rely on code which is responsible for acquiring metadata locks on object to be changed acquiring this protection. This is achieved by acquiring global IX metadata lock with statement duration. Code doing this also responsible for checking that current connection has no active GRL by calling an Global_read_lock::can_acquire_protection() method. Changed code in open_table() and lock_table_names() accordingly. Note that as result of this change DDL and DML on temporary tables is always compatible with GRL (before it was incompatible in some cases and compatible in other cases). - To speed-up code acquiring protection against GRL introduced m_has_protection_against_grl member in Open_table_context class. It indicates that protection was already acquired sometime during open_tables() execution and new attempts can be skipped. - Thanks to new GRL implementation calls to broadcast_refresh() became unnecessary and were removed. - Adjusted code to the fact that one now needs specify duration of lock when initializing MDL_request and to the fact that savepoints for MDL subsystem are now represented by MDL_savepoint class. sql/sql_base.h: Adjusted code to the fact that savepoints for MDL subsystem are now represented by MDL_savepoint class. Also introduced Open_table_context::m_has_protection_against_grl member which allows to avoid acquiring protection against GRL while opening tables if such protection was already acquired. sql/sql_class.cc: Changed THD::leave_locked_tables_mode() after transactional sentinel for metadata locks was obsoleted by introduction of locks with explicit duration. sql/sql_class.h: - Adjusted code to the fact that savepoints for MDL subsystem are now represented by MDL_savepoint class. - Changed Global_read_lock class according to changes in global read lock implementation: * wait_if_global_read_lock and start_waiting_global_read_lock are now gone. Instead code needing protection against GRL has to acquire global IX metadata lock with statement duration itself. To help it new can_acquire_protection() was introduced. Also as result of the above change m_protection_count member is gone too. * Added m_mdl_blocks_commits_lock member to store metadata lock blocking commits. * Adjusted code to the fact that concept of transactional sentinel was obsoleted by concept of lock duration. - Removed CF_PROTECT_AGAINST_GRL flag as it is no longer necessary. New GRL implementation acquires protection against global read lock automagically when statement acquires metadata locks on tables or other objects it is going to change. sql/sql_db.cc: Adjusted code to the fact that one now needs specify duration of lock when initializing MDL_request. sql/sql_handler.cc: Removed call to broadcast_refresh() function. It is no longer needed with new GRL implementation. Adjusted code after introducing duration concept for metadata locks. Particularly to the fact transactional sentinel was replaced with explicit duration. sql/sql_handler.h: Renamed mysql_ha_move_tickets_after_trans_sentinel() to mysql_ha_set_explicit_lock_duration() after transactional sentinel was obsoleted by locks with explicit duration. sql/sql_insert.cc: Adjusted code handling delaying inserts after switching to new GRL implementation. Now connection thread initiating delayed insert has to acquire global IX lock in addition to metadata lock on table being inserted into. This IX lock protects against GRL and similarly to SW lock on table being inserted into has to be passed to handler thread in order to avoid deadlocks. sql/sql_lex.cc: LEX::protect_against_global_read_lock member is no longer necessary since protection against GRL is automatically taken by code acquiring metadata locks/opening tables. sql/sql_lex.h: LEX::protect_against_global_read_lock member is no longer necessary since protection against GRL is automatically taken by code acquiring metadata locks/opening tables. sql/sql_parse.cc: - Implemented support for new approach to acquiring protection against global read lock. We no longer acquire such protection explicitly on the basis of statement flags. Instead we always rely on code which is responsible for acquiring metadata locks on object to be changed acquiring this protection. This is achieved by acquiring global IX metadata lock with statement duration. This lock is automatically released at the end of statement execution. - Changed implementation of CREATE/DROP PROCEDURE/FUNCTION not to release metadata locks and thus protection against of GRL in the middle of statement execution. - Adjusted code to the fact that one now needs specify duration of lock when initializing MDL_request and to the fact that savepoints for MDL subsystem are now represented by MDL_savepoint class. sql/sql_prepare.cc: Adjusted code to the to the fact that savepoints for MDL subsystem are now represented by MDL_savepoint class. sql/sql_rename.cc: With new GRL implementation there is no need to explicitly acquire protection against GRL before renaming tables. This happens automatically in code which acquires metadata locks on tables being renamed. sql/sql_show.cc: Adjusted code to the fact that one now needs specify duration of lock when initializing MDL_request and to the fact that savepoints for MDL subsystem are now represented by MDL_savepoint class. sql/sql_table.cc: - With new GRL implementation there is no need to explicitly acquire protection against GRL before dropping tables. This happens automatically in code which acquires metadata locks on tables being dropped. - Changed mysql_alter_table() not to release lock on new table name explicitly and to rely on automatic release of locks at the end of statement instead. This was necessary since now MDL_context::release_lock() is supported only for locks for explicit duration. sql/sql_trigger.cc: With new GRL implementation there is no need to explicitly acquire protection against GRL before changing table triggers. This happens automatically in code which acquires metadata locks on tables which triggers are to be changed. sql/sql_update.cc: Fix bug exposed by GRL testing. During prepare phase acquire only S metadata locks instead of SW locks to keep prepare of multi-UPDATE compatible with concurrent LOCK TABLES WRITE and global read lock. sql/sql_view.cc: With new GRL implementation there is no need to explicitly acquire protection against GRL before creating view. This happens automatically in code which acquires metadata lock on view to be created. sql/sql_yacc.yy: LEX::protect_against_global_read_lock member is no longer necessary since protection against GRL is automatically taken by code acquiring metadata locks/opening tables. sql/table.cc: Adjusted code to the fact that one now needs specify duration of lock when initializing MDL_request. sql/table.h: Adjusted code to the fact that one now needs specify duration of lock when initializing MDL_request. sql/transaction.cc: Replaced custom implementation of global read lock with one based on metadata locks. Consequently when doing commit instead of calling method of Global_read_lock class to acquire protection against GRL we simply acquire IX in COMMIT namespace. Also adjusted code to the fact that MDL savepoint is now represented by MDL_savepoint class. --- sql/sql_trigger.cc | 14 -------------- 1 file changed, 14 deletions(-) (limited to 'sql/sql_trigger.cc') diff --git a/sql/sql_trigger.cc b/sql/sql_trigger.cc index a9b52eee9fc..c2e3cd9944a 100644 --- a/sql/sql_trigger.cc +++ b/sql/sql_trigger.cc @@ -24,8 +24,6 @@ #include "parse_file.h" #include "sp.h" #include "sql_base.h" // find_temporary_table -#include "lock.h" // wait_if_global_read_lock, - // start_waiting_global_read_lock #include "sql_show.h" // append_definer, append_identifier #include "sql_table.h" // build_table_filename, // check_n_cut_mysql50_prefix @@ -391,15 +389,6 @@ bool mysql_create_or_drop_trigger(THD *thd, TABLE_LIST *tables, bool create) DBUG_RETURN(TRUE); } - /* - We don't want perform our operations while global read lock is held - so we have to wait until its end and then prevent it from occurring - again until we are done, unless we are under lock tables. - */ - if (!thd->locked_tables_mode && - thd->global_read_lock.wait_if_global_read_lock(thd, FALSE, TRUE)) - DBUG_RETURN(TRUE); - if (!create) { bool if_exists= thd->lex->drop_if_exists; @@ -547,9 +536,6 @@ end: if (!create) thd->lex->restore_backup_query_tables_list(&backup); - if (thd->global_read_lock.has_protection()) - thd->global_read_lock.start_waiting_global_read_lock(thd); - if (!result) my_ok(thd); -- cgit v1.2.1 From bafe24035dbf6d5452d7328ab45d6b43abe52d54 Mon Sep 17 00:00:00 2001 From: Jon Olav Hauglid Date: Mon, 7 Mar 2011 10:08:10 +0100 Subject: Bug #11764779 (former 57649) FLUSH TABLES under FLUSH TABLES WITH READ LOCK leads to assert failure. This assert was triggered if a statement tried up upgrade a metadata lock with an active FLUSH TABLE WITH READ LOCK. The assert checks that the connection already holds a global intention exclusive metadata lock. However, FLUSH TABLE WITH READ LOCK does not acquire this lock in order to be compatible with FLUSH TABLES WITH READ LOCK. Therefore any metadata lock upgrade caused the assert to be triggered. This patch fixes the problem by preventing metadata lock upgrade if the connection has an active FLUSH TABLE WITH READ LOCK. ER_TABLE_NOT_LOCKED_FOR_WRITE will instead be reported to the client. Test case added to flush.test. --- sql/sql_trigger.cc | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'sql/sql_trigger.cc') diff --git a/sql/sql_trigger.cc b/sql/sql_trigger.cc index c2e3cd9944a..e986f6d7e92 100644 --- a/sql/sql_trigger.cc +++ b/sql/sql_trigger.cc @@ -1,4 +1,4 @@ -/* Copyright (C) 2004-2005 MySQL AB, 2008-2009 Sun Microsystems, Inc +/* Copyright (c) 2004, 2011, Oracle and/or its affiliates. All rights reserved. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -467,8 +467,7 @@ bool mysql_create_or_drop_trigger(THD *thd, TABLE_LIST *tables, bool create) if (thd->locked_tables_mode) { /* Under LOCK TABLES we must only accept write locked tables. */ - if (!(tables->table= find_table_for_mdl_upgrade(thd->open_tables, - tables->db, + if (!(tables->table= find_table_for_mdl_upgrade(thd, tables->db, tables->table_name, FALSE))) goto end; -- cgit v1.2.1 From 5653a71d3ec08e64098b430fcd7def790e249fa3 Mon Sep 17 00:00:00 2001 From: Alexander Nozdrin Date: Thu, 10 Mar 2011 11:07:57 +0300 Subject: Patch for Bug#11765684 (58674: SP-cache does not detect changes in pre-locking list caused by triggers). The thing is that CREATE TRIGGER / DROP TRIGGER may actually change pre-locking list of (some) stored routines. The SP-cache does not detect such changes. Thus if sp_head-instance is cached in SP-cache, subsequent executions of the cached sp_head will use inaccurate pre-locking list. The patch is to invalidate SP-cache on CREATE TRIGGER / DROP TRIGGER. --- sql/sql_trigger.cc | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'sql/sql_trigger.cc') diff --git a/sql/sql_trigger.cc b/sql/sql_trigger.cc index e986f6d7e92..4908fce5950 100644 --- a/sql/sql_trigger.cc +++ b/sql/sql_trigger.cc @@ -30,6 +30,7 @@ #include "sql_db.h" // get_default_db_collation #include "sql_acl.h" // *_ACL, is_acl_user #include "sql_handler.h" // mysql_ha_rm_tables +#include "sp_cache.h" // sp_invalidate_cache /*************************************************************************/ @@ -517,6 +518,12 @@ bool mysql_create_or_drop_trigger(THD *thd, TABLE_LIST *tables, bool create) */ thd->locked_tables_list.reopen_tables(thd); + /* + Invalidate SP-cache. That's needed because triggers may change list of + pre-locking tables. + */ + sp_cache_invalidate(); + end: if (!result) { -- cgit v1.2.1 From 060541c02e6c332db0f08fa3b861cb2de305c71f Mon Sep 17 00:00:00 2001 From: Alexander Nozdrin Date: Fri, 15 Apr 2011 16:02:22 +0400 Subject: A patch for Bug#11763166 (55847: SHOW WARNINGS returns empty result set when SQLEXCEPTION is active. The problem was in a hackish THD::no_warnings_for_error attribute. When it was set, an error was not written to Warning_info -- only Diagnostics_area state was changed. That means, Diagnostics_area might contain error state, which is not present in Warning_info. The user-visible problem was that in some cases SHOW WARNINGS returned empty result set (i.e. there were no warnings) while the previous SQL statement failed. According to the MySQL protocol errors must be presented in warning list. The main idea of this patch is to remove THD::no_warnings_for_error. There were few places where it was used: - sql_admin.cc, handling of REPAIR TABLE USE_FRM. - sql_show.cc, when calling fill_schema_table_from_frm(). - sql_show.cc, when calling fill_table(). The fix is to either use internal-error-handlers, or to use temporary Warning_info storing warnings, which might be ignored. This patch is needed to fix Bug 11763162 (55843). --- sql/sql_trigger.cc | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-) (limited to 'sql/sql_trigger.cc') diff --git a/sql/sql_trigger.cc b/sql/sql_trigger.cc index 4908fce5950..d026714c007 100644 --- a/sql/sql_trigger.cc +++ b/sql/sql_trigger.cc @@ -1225,13 +1225,12 @@ bool Table_triggers_list::check_n_load(THD *thd, const char *db, DBUG_RETURN(1); // EOM } - - if (!thd->no_warnings_for_error) - push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_WARN, - ER_TRG_NO_CREATION_CTX, - ER(ER_TRG_NO_CREATION_CTX), - (const char*) db, - (const char*) table_name); + + push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_WARN, + ER_TRG_NO_CREATION_CTX, + ER(ER_TRG_NO_CREATION_CTX), + (const char*) db, + (const char*) table_name); if (!(trg_client_cs_name= alloc_lex_string(&table->mem_root)) || !(trg_connection_cl_name= alloc_lex_string(&table->mem_root)) || @@ -1362,12 +1361,12 @@ bool Table_triggers_list::check_n_load(THD *thd, const char *db, MySQL, which does not support triggers definers. We should emit warning here. */ - if (!thd->no_warnings_for_error) - push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_WARN, - ER_TRG_NO_DEFINER, ER(ER_TRG_NO_DEFINER), - (const char*) db, - (const char*) sp->m_name.str); - + + push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_WARN, + ER_TRG_NO_DEFINER, ER(ER_TRG_NO_DEFINER), + (const char*) db, + (const char*) sp->m_name.str); + /* Set definer to the '' to correct displaying in the information schema. -- cgit v1.2.1 From 1fea8c1b9070018be12f9c748fec781322944d7c Mon Sep 17 00:00:00 2001 From: Dmitry Shulga Date: Fri, 10 Jun 2011 10:52:39 +0700 Subject: Fixed bug#11753738 (formely known as bug#45235) - 5.1 DOES NOT SUPPORT 5.0-ONLY SYNTAX TRIGGERS IN ANY WAY Table with triggers which were using deprecated (5.0-only) syntax became unavailable for any DML and DDL after upgrade to 5.1 version of server. Attempt to execute any statement on such a table resulted in parsing error reported. Since this included DROP TRIGGER and DROP TABLE statements (actually, the latter was allowed but was not functioning properly for such tables) it was impossible to fix the problem without manual operations on .TRG and .TRN files in data directory. The problem was that failure to parse trigger body (due to 5.0-only syntax) when opening trigger file for a table prevented the table from being open. This made all operations on the table impossible (except DROP TABLE which due to peculiarity in its implementation dropped the table but left trigger files around). This patch solves this problem by silencing error which occurs when we parse trigger body during table open. Error message is preserved for the future use and table is marked as having a broken trigger. We also try to analyze parse tree to recover trigger name, which will be needed in order to drop the broken trigger. DML statements which invoke triggers on the table marked as having broken trigger are prohibited and emit saved error message. The same happens for DDL which change triggers except DROP TRIGGER and DROP TABLE which try their best to do what was requested. Table becomes no longer marked as having broken trigger when last such trigger is dropped. mysql-test/r/trigger-compat.result: Add results for test case for bug#45235 mysql-test/t/trigger-compat.test: Add test case for bug#45235. sql/sp_head.cc: Added protection against MEM_ROOT double restoring to sp_head::restore_thd_mem_root() method. Since this method can be sometimes called twice during parsing of stored routine (the first time during normal flow of parsing, and the second time when a syntax error is detected) we need to shortcut execution of the method to avoid damaging MEM_ROOT by the second consecutive call to this method. sql/sql_trigger.cc: Added error handler Deprecated_trigger_syntax_handler to catch non-OOM errors during parsing of trigger body. Added handling of parse errors into method Table_triggers_list::check_n_load(). sql/sql_trigger.h: Added new members to handle broken triggers and error messages. --- sql/sql_trigger.cc | 148 ++++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 136 insertions(+), 12 deletions(-) (limited to 'sql/sql_trigger.cc') diff --git a/sql/sql_trigger.cc b/sql/sql_trigger.cc index 9348feaa22a..89ee411c8da 100644 --- a/sql/sql_trigger.cc +++ b/sql/sql_trigger.cc @@ -19,6 +19,7 @@ #include "sp_head.h" #include "sql_trigger.h" #include "parse_file.h" +#include /*************************************************************************/ @@ -292,6 +293,52 @@ private: }; +/** + An error handler that catches all non-OOM errors which can occur during + parsing of trigger body. Such errors are ignored and corresponding error + message is used to construct a more verbose error message which contains + name of problematic trigger. This error message is later emitted when + one tries to perform DML or some of DDL on this table. + Also, if possible, grabs name of the trigger being parsed so it can be + used to correctly drop problematic trigger. +*/ +class Deprecated_trigger_syntax_handler : public Internal_error_handler +{ +private: + + char m_message[MYSQL_ERRMSG_SIZE]; + LEX_STRING *m_trigger_name; + +public: + + Deprecated_trigger_syntax_handler() : m_trigger_name(NULL) {} + + virtual bool handle_error(uint sql_errno, const char *message, + MYSQL_ERROR::enum_warning_level level, THD *thd) + { + if (sql_errno != EE_OUTOFMEMORY && + sql_errno != ER_OUT_OF_RESOURCES) + { + if(thd->lex->spname) + m_trigger_name= &thd->lex->spname->m_name; + if (m_trigger_name) + my_snprintf(m_message, sizeof(m_message), + "Trigger '%s' has an error in its body: '%s'", + m_trigger_name->str, message); + else + my_snprintf(m_message, sizeof(m_message), + "Unknown trigger has an error in its body: '%s'", + message); + return true; + } + return false; + } + + LEX_STRING *get_trigger_name() { return m_trigger_name; } + char *get_error_message() { return m_message; } +}; + + /** Create or drop trigger for table. @@ -575,6 +622,8 @@ bool Table_triggers_list::create_trigger(THD *thd, TABLE_LIST *tables, LEX_STRING *trg_connection_cl_name; LEX_STRING *trg_db_cl_name; + if (check_for_broken_triggers()) + return true; /* Trigger must be in the same schema as target table. */ if (my_strcasecmp(table_alias_charset, table->s->db.str, @@ -848,7 +897,7 @@ static bool rm_trigger_file(char *path, const char *db, @param path char buffer of size FN_REFLEN to be used for constructing path to .TRN file. @param db trigger's database name - @param table_name trigger's name + @param trigger_name trigger's name @retval False success @@ -1312,12 +1361,11 @@ bool Table_triggers_list::check_n_load(THD *thd, const char *db, lex_start(thd); thd->spcont= NULL; - if (parse_sql(thd, & parser_state, creation_ctx)) - { - /* Currently sphead is always deleted in case of a parse error */ - DBUG_ASSERT(lex.sphead == 0); - goto err_with_lex_cleanup; - } + Deprecated_trigger_syntax_handler error_handler; + thd->push_internal_handler(&error_handler); + bool parse_error= parse_sql(thd, & parser_state, creation_ctx); + thd->pop_internal_handler(); + /* Not strictly necessary to invoke this method here, since we know that we've parsed CREATE TRIGGER and not an @@ -1328,6 +1376,52 @@ bool Table_triggers_list::check_n_load(THD *thd, const char *db, */ lex.set_trg_event_type_for_tables(); + if (parse_error) + { + if (!triggers->m_has_unparseable_trigger) + triggers->set_parse_error_message(error_handler.get_error_message()); + /* Currently sphead is always set to NULL in case of a parse error */ + DBUG_ASSERT(lex.sphead == 0); + if (error_handler.get_trigger_name()) + { + LEX_STRING *trigger_name; + const LEX_STRING *orig_trigger_name= error_handler.get_trigger_name(); + + if (!(trigger_name= alloc_lex_string(&table->mem_root)) || + !(trigger_name->str= strmake_root(&table->mem_root, + orig_trigger_name->str, + orig_trigger_name->length))) + goto err_with_lex_cleanup; + + trigger_name->length= orig_trigger_name->length; + + if (triggers->names_list.push_back(trigger_name, + &table->mem_root)) + goto err_with_lex_cleanup; + } + else + { + /* + The Table_triggers_list is not constructed as a list of + trigger objects as one would expect, but rather of lists of + properties of equal length. Thus, even if we don't get the + trigger name, we still fill all in all the lists with + placeholders as we might otherwise create a skew in the + lists. Obviously, this has to be refactored. + */ + LEX_STRING *empty= alloc_lex_string(&table->mem_root); + if (!empty) + goto err_with_lex_cleanup; + + empty->str= const_cast(""); + empty->length= 0; + if (triggers->names_list.push_back(empty, &table->mem_root)) + goto err_with_lex_cleanup; + } + lex_end(&lex); + continue; + } + lex.sphead->set_info(0, 0, &lex.sp_chistics, (ulong) *trg_sql_mode); int event= lex.trg_chistics.event; @@ -1368,8 +1462,8 @@ bool Table_triggers_list::check_n_load(THD *thd, const char *db, if (triggers->names_list.push_back(&lex.sphead->m_name, &table->mem_root)) - goto err_with_lex_cleanup; - + goto err_with_lex_cleanup; + if (!(on_table_name= alloc_lex_string(&table->mem_root))) goto err_with_lex_cleanup; @@ -1394,9 +1488,8 @@ bool Table_triggers_list::check_n_load(THD *thd, const char *db, char fname[NAME_LEN + 1]; DBUG_ASSERT((!my_strcasecmp(table_alias_charset, lex.query_tables->db, db) || (check_n_cut_mysql50_prefix(db, fname, sizeof(fname)) && - !my_strcasecmp(table_alias_charset, lex.query_tables->db, fname))) && - (!my_strcasecmp(table_alias_charset, lex.query_tables->table_name, - table_name) || + !my_strcasecmp(table_alias_charset, lex.query_tables->db, fname)))); + DBUG_ASSERT((!my_strcasecmp(table_alias_charset, lex.query_tables->table_name, table_name) || (check_n_cut_mysql50_prefix(table_name, fname, sizeof(fname)) && !my_strcasecmp(table_alias_charset, lex.query_tables->table_name, fname)))); #endif @@ -1680,6 +1773,13 @@ bool Table_triggers_list::drop_all_triggers(THD *thd, char *db, char *name) while ((trigger= it_name++)) { + /* + Trigger, which body we failed to parse during call + Table_triggers_list::check_n_load(), might be missing name. + Such triggers have zero-length name and are skipped here. + */ + if (trigger->length == 0) + continue; if (rm_trigname_file(path, db, trigger->str)) { /* @@ -1903,6 +2003,11 @@ bool Table_triggers_list::change_table_name(THD *thd, const char *db, } if (table.triggers) { + if (table.triggers->check_for_broken_triggers()) + { + result= 1; + goto end; + } LEX_STRING old_table_name= { (char *) old_table, strlen(old_table) }; LEX_STRING new_table_name= { (char *) new_table, strlen(new_table) }; /* @@ -1991,6 +2096,9 @@ bool Table_triggers_list::process_triggers(THD *thd, sp_head *sp_trigger= bodies[event][time_type]; SELECT_LEX *save_current_select; + if (check_for_broken_triggers()) + return true; + if (sp_trigger == NULL) return FALSE; @@ -2069,6 +2177,22 @@ void Table_triggers_list::mark_fields_used(trg_event_type event) } +/** + Signals to the Table_triggers_list that a parse error has occured when + reading a trigger from file. This makes the Table_triggers_list enter an + error state flagged by m_has_unparseable_trigger == true. The error message + will be used whenever a statement invoking or manipulating triggers is + issued against the Table_triggers_list's table. + + @param error_message The error message thrown by the parser. + */ +void Table_triggers_list::set_parse_error_message(char *error_message) +{ + m_has_unparseable_trigger= true; + strcpy(m_parse_error_message, error_message); +} + + /** Trigger BUG#14090 compatibility hook. -- cgit v1.2.1