diff options
Diffstat (limited to 'sql/sql_reload.cc')
| -rw-r--r-- | sql/sql_reload.cc | 649 |
1 files changed, 649 insertions, 0 deletions
diff --git a/sql/sql_reload.cc b/sql/sql_reload.cc new file mode 100644 index 00000000..2974c770 --- /dev/null +++ b/sql/sql_reload.cc @@ -0,0 +1,649 @@ +/* Copyright (c) 2010, 2016, Oracle and/or its affiliates. + Copyright (c) 2011, 2016, MariaDB + + 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 + the Free Software Foundation; version 2 of the License. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */ + +#include "mariadb.h" +#include "sql_reload.h" +#include "sql_priv.h" +#include "mysqld.h" // select_errors +#include "sql_class.h" // THD +#include "sql_acl.h" // acl_reload +#include "sql_servers.h" // servers_reload +#include "sql_connect.h" // reset_mqh +#include "thread_cache.h" +#include "sql_base.h" // close_cached_tables +#include "sql_db.h" // my_dbopt_cleanup +#include "hostname.h" // hostname_cache_refresh +#include "sql_repl.h" // reset_master, reset_slave +#include "rpl_mi.h" // Master_info::data_lock +#include "sql_show.h" +#include "debug_sync.h" +#include "des_key_file.h" +#include "transaction.h" + +static void disable_checkpoints(THD *thd); + +/** + Reload/resets privileges and the different caches. + + @param thd Thread handler (can be NULL!) + @param options What should be reset/reloaded (tables, privileges, slave...) + @param tables Tables to flush (if any) + @param write_to_binlog < 0 if there was an error while interacting with the binary log inside + reload_acl_and_cache, + 0 if we should not write to the binary log, + > 0 if we can write to the binlog. + + + @note Depending on 'options', it may be very bad to write the + query to the binlog (e.g. FLUSH SLAVE); this is a + pointer where reload_acl_and_cache() will put 0 if + it thinks we really should not write to the binlog. + Otherwise it will put 1. + + @return Error status code + @retval 0 Ok + @retval !=0 Error; thd->killed is set or thd->is_error() is true +*/ + +bool reload_acl_and_cache(THD *thd, unsigned long long options, + TABLE_LIST *tables, int *write_to_binlog) +{ + bool result=0; + select_errors=0; /* Write if more errors */ + int tmp_write_to_binlog= *write_to_binlog= 1; + + DBUG_ASSERT(!thd || !thd->in_sub_stmt); + +#ifndef NO_EMBEDDED_ACCESS_CHECKS + if (options & REFRESH_GRANT) + { + THD *tmp_thd= 0; + /* + If reload_acl_and_cache() is called from SIGHUP handler we have to + allocate temporary THD for execution of acl_reload()/grant_reload(). + */ + if (unlikely(!thd) && (thd= (tmp_thd= new THD(0)))) + { + thd->thread_stack= (char*) &tmp_thd; + thd->store_globals(); + } + + if (likely(thd)) + { + bool reload_acl_failed= acl_reload(thd); + bool reload_grants_failed= grant_reload(thd); + bool reload_servers_failed= servers_reload(thd); + + if (reload_acl_failed || reload_grants_failed || reload_servers_failed) + { + result= 1; + /* + When an error is returned, my_message may have not been called and + the client will hang waiting for a response. + */ + my_error(ER_UNKNOWN_ERROR, MYF(0)); + } + } + opt_noacl= 0; + + if (unlikely(tmp_thd)) + { + delete tmp_thd; + thd= 0; + } + reset_mqh((LEX_USER *)NULL, TRUE); + } +#endif + if (options & REFRESH_LOG) + { + /* + Flush the normal query log, the update log, the binary log, + the slow query log, the relay log (if it exists) and the log + tables. + */ + + options|= REFRESH_BINARY_LOG; + options|= REFRESH_RELAY_LOG; + options|= REFRESH_SLOW_LOG; + options|= REFRESH_GENERAL_LOG; + options|= REFRESH_ENGINE_LOG; + options|= REFRESH_ERROR_LOG; + } + + if (options & REFRESH_ERROR_LOG) + if (unlikely(flush_error_log())) + result= 1; + + if ((options & REFRESH_SLOW_LOG) && global_system_variables.sql_log_slow) + logger.flush_slow_log(); + + if ((options & REFRESH_GENERAL_LOG) && opt_log) + logger.flush_general_log(); + + if (options & REFRESH_ENGINE_LOG) + if (ha_flush_logs()) + result= 1; + + if (options & REFRESH_BINARY_LOG) + { + /* + Writing this command to the binlog may result in infinite loops + when doing mysqlbinlog|mysql, and anyway it does not really make + sense to log it automatically (would cause more trouble to users + than it would help them) + */ + tmp_write_to_binlog= 0; + if (mysql_bin_log.is_open()) + { + DYNAMIC_ARRAY *drop_gtid_domain= + (thd && (thd->lex->delete_gtid_domain.elements > 0)) ? + &thd->lex->delete_gtid_domain : NULL; + if (mysql_bin_log.rotate_and_purge(true, drop_gtid_domain)) + *write_to_binlog= -1; + + /* Note that WSREP(thd) might not be true here e.g. during + SST. */ + if (WSREP_ON) + { + /* Wait for last binlog checkpoint event to be logged. */ + mysql_bin_log.wait_for_last_checkpoint_event(); + } + } + } + if (options & REFRESH_RELAY_LOG) + { +#ifdef HAVE_REPLICATION + LEX_CSTRING connection_name; + Master_info *mi; + if (thd) + connection_name= thd->lex->relay_log_connection_name; + else + { + connection_name.str= (char*) ""; + connection_name.length= 0; + } + + /* + Writing this command to the binlog may cause problems as the + slave is not likely to have the same connection names. + */ + tmp_write_to_binlog= 0; + if (connection_name.length == 0) + { + if (master_info_index->flush_all_relay_logs()) + *write_to_binlog= -1; + } + else if (!(mi= (get_master_info(&connection_name, + Sql_condition::WARN_LEVEL_ERROR)))) + { + result= 1; + } + else + { + mysql_mutex_lock(&mi->data_lock); + if (rotate_relay_log(mi)) + *write_to_binlog= -1; + mysql_mutex_unlock(&mi->data_lock); + mi->release(); + } +#endif + } +#ifdef HAVE_QUERY_CACHE + if (options & REFRESH_QUERY_CACHE_FREE) + { + query_cache.pack(thd); // FLUSH QUERY CACHE + options &= ~REFRESH_QUERY_CACHE; // Don't flush cache, just free memory + } + if (options & (REFRESH_TABLES | REFRESH_QUERY_CACHE)) + { + query_cache.flush(); // RESET QUERY CACHE + } +#endif /*HAVE_QUERY_CACHE*/ + + DBUG_ASSERT(!thd || thd->locked_tables_mode || + !thd->mdl_context.has_locks() || + thd->handler_tables_hash.records || + thd->ull_hash.records || + thd->global_read_lock.is_acquired() || + thd->mdl_backup_lock || + thd->current_backup_stage != BACKUP_FINISHED + ); + + /* + Note that if REFRESH_READ_LOCK bit is set then REFRESH_TABLES is set too + (see sql_yacc.yy) + */ + if (options & (REFRESH_TABLES | REFRESH_READ_LOCK)) + { + if ((options & REFRESH_READ_LOCK) && thd) + { + DBUG_ASSERT(!(options & REFRESH_FAST) && !tables); + /* + On the first hand we need write lock on the tables to be flushed, + on the other hand we must not try to aspire a global read lock + if we have a write locked table as this would lead to a deadlock + when trying to reopen (and re-lock) the table after the flush. + */ + if (thd->locked_tables_mode) + { + my_error(ER_LOCK_OR_ACTIVE_TRANSACTION, MYF(0)); + return 1; + } + + /* + Writing to the binlog could cause deadlocks, as we don't log + UNLOCK TABLES + */ + tmp_write_to_binlog= 0; + if (thd->global_read_lock.lock_global_read_lock(thd)) + return 1; // Killed + if (flush_tables(thd, FLUSH_ALL)) + { + /* + NOTE: my_error() has been already called by reopen_tables() within + close_cached_tables(). + */ + thd->global_read_lock.unlock_global_read_lock(thd); + return 1; + } + + if (thd->global_read_lock.make_global_read_lock_block_commit(thd)) // Killed + { + /* Don't leave things in a half-locked state */ + thd->global_read_lock.unlock_global_read_lock(thd); + return 1; + } + if (options & REFRESH_CHECKPOINT) + disable_checkpoints(thd); + /* + We need to do it second time after wsrep appliers were blocked in + make_global_read_lock_block_commit(thd) above since they could have + modified the tables too. + */ + if (WSREP(thd) && flush_tables(thd, FLUSH_ALL)) + result= 1; + } + else + { + if (thd && thd->locked_tables_mode) + { + /* + If we are under LOCK TABLES we should have a write + lock on tables which we are going to flush. + */ + if (tables) + { + int err; + for (TABLE_LIST *t= tables; t; t= t->next_local) + if (!find_table_for_mdl_upgrade(thd, t->db.str, t->table_name.str, &err)) + { + if (is_locked_view(thd, t)) + t->next_local= t->next_global; + else + { + my_error(err, MYF(0), t->table_name.str); + return 1; + } + } + } + else + { + /* + It is not safe to upgrade the metadata lock without GLOBAL IX lock. + This can happen with FLUSH TABLES <list> WITH READ LOCK as we in + these cases don't take a GLOBAL IX lock in order to be compatible + with global read lock. + */ + if (thd->open_tables && + !thd->mdl_context.is_lock_owner(MDL_key::BACKUP, "", "", + MDL_BACKUP_DDL)) + { + my_error(ER_TABLE_NOT_LOCKED_FOR_WRITE, MYF(0), + thd->open_tables->s->table_name.str); + return true; + } + + for (TABLE *tab= thd->open_tables; tab; tab= tab->next) + { + if (! tab->mdl_ticket->is_upgradable_or_exclusive()) + { + my_error(ER_TABLE_NOT_LOCKED_FOR_WRITE, MYF(0), + tab->s->table_name.str); + return 1; + } + } + } + } + +#ifdef WITH_WSREP + /* In case of applier thread, do not call flush tables */ + if (!thd || !thd->wsrep_applier) +#endif /* WITH_WSREP */ + { + if (close_cached_tables(thd, tables, + ((options & REFRESH_FAST) ? FALSE : TRUE), + (thd ? thd->variables.lock_wait_timeout : + LONG_TIMEOUT))) + { + /* + NOTE: my_error() has been already called by reopen_tables() within + close_cached_tables(). + */ + result= 1; + } + } + } + my_dbopt_cleanup(); + } + if (options & REFRESH_HOSTS) + hostname_cache_refresh(); + if (thd && (options & REFRESH_STATUS)) + refresh_status(thd); + if (options & REFRESH_THREADS) + thread_cache.flush(); +#ifdef HAVE_REPLICATION + if (options & REFRESH_MASTER) + { + DBUG_ASSERT(thd); + tmp_write_to_binlog= 0; + if (reset_master(thd, NULL, 0, thd->lex->next_binlog_file_number)) + { + /* NOTE: my_error() has been already called by reset_master(). */ + result= 1; + } + } +#endif +#ifdef HAVE_OPENSSL + if (options & REFRESH_DES_KEY_FILE) + { + if (des_key_file && load_des_key_file(des_key_file)) + { + /* NOTE: my_error() has been already called by load_des_key_file(). */ + result= 1; + } + } +#endif +#ifdef HAVE_REPLICATION + if (options & REFRESH_SLAVE) + { + LEX_MASTER_INFO* lex_mi= &thd->lex->mi; + Master_info *mi; + tmp_write_to_binlog= 0; + + if (!(mi= get_master_info(&lex_mi->connection_name, + Sql_condition::WARN_LEVEL_ERROR))) + { + result= 1; + } + else + { + /* The following will fail if slave is running */ + if (reset_slave(thd, mi)) + { + mi->release(); + /* NOTE: my_error() has been already called by reset_slave(). */ + result= 1; + } + else if (mi->connection_name.length && thd->lex->reset_slave_info.all) + { + /* If not default connection and 'all' is used */ + mi->release(); + mysql_mutex_lock(&LOCK_active_mi); + if (master_info_index->remove_master_info(mi)) + result= 1; + mysql_mutex_unlock(&LOCK_active_mi); + } + else + mi->release(); + } + } +#endif + if (options & REFRESH_USER_RESOURCES) + reset_mqh((LEX_USER *) NULL, 0); /* purecov: inspected */ + if (options & REFRESH_SSL) + { + if (reinit_ssl()) + result= 1; +#ifdef WITH_WSREP + if (!result && + WSREP_ON && wsrep_reload_ssl()) + { + my_message(ER_UNKNOWN_ERROR, "Failed to refresh WSREP SSL.", MYF(0)); + result= 1; + } +#endif + } + if (options & REFRESH_GENERIC) + { + List_iterator_fast<LEX_CSTRING> li(thd->lex->view_list); + LEX_CSTRING *ls; + while ((ls= li++)) + { + ST_SCHEMA_TABLE *table= find_schema_table(thd, ls); + if (table->reset_table()) + result= 1; + } + } + if (*write_to_binlog != -1) + *write_to_binlog= tmp_write_to_binlog; + /* + If the query was killed then this function must fail. + */ + return result || (thd ? thd->killed : 0); +} + + +/** + Implementation of FLUSH TABLES <table_list> WITH READ LOCK + and FLUSH TABLES <table_list> FOR EXPORT + + In brief: take exclusive locks, expel tables from the table + cache, reopen the tables, enter the 'LOCKED TABLES' mode, + downgrade the locks. + Note: the function is written to be called from + mysql_execute_command(), it is not reusable in arbitrary + execution context. + + Required privileges + ------------------- + Since the statement implicitly enters LOCK TABLES mode, + it requires LOCK TABLES privilege on every table. + But since the rest of FLUSH commands require + the global RELOAD_ACL, it also requires RELOAD_ACL. + + Compatibility with the global read lock + --------------------------------------- + We don't wait for the GRL, since neither the + 5.1 combination that this new statement is intended to + replace (LOCK TABLE <list> WRITE; FLUSH TABLES;), + nor FLUSH TABLES WITH READ LOCK do. + @todo: this is not implemented, Dmitry disagrees. + Currently we wait for GRL in another connection, + but are compatible with a GRL in our own connection. + + Behaviour under LOCK TABLES + --------------------------- + Bail out: i.e. don't perform an implicit UNLOCK TABLES. + This is not consistent with LOCK TABLES statement, but is + in line with behaviour of FLUSH TABLES WITH READ LOCK, and we + try to not introduce any new statements with implicit + semantics. + + Compatibility with parallel updates + ----------------------------------- + As a result, we will wait for all open transactions + against the tables to complete. After the lock downgrade, + new transactions will be able to read the tables, but not + write to them. + + Differences from FLUSH TABLES <list> + ------------------------------------- + - you can't flush WITH READ LOCK a non-existent table + - you can't flush WITH READ LOCK under LOCK TABLES + + Effect on views and temporary tables. + ------------------------------------ + You can only apply this command to existing base tables. + If a view with such name exists, ER_WRONG_OBJECT is returned. + If a temporary table with such name exists, it's ignored: + if there is a base table, it's used, otherwise ER_NO_SUCH_TABLE + is returned. + + Handling of MERGE tables + ------------------------ + For MERGE table this statement will open and lock child tables + for read (it is impossible to lock parent table without it). + Child tables won't be flushed unless they are explicitly present + in the statement's table list. + + Implicit commit + --------------- + This statement causes an implicit commit before and + after it. + + HANDLER SQL + ----------- + If this connection has HANDLERs open against + some of the tables being FLUSHed, these handlers + are implicitly flushed (lose their position). +*/ + +bool flush_tables_with_read_lock(THD *thd, TABLE_LIST *all_tables) +{ + Lock_tables_prelocking_strategy lock_tables_prelocking_strategy; + + /* + This is called from SQLCOM_FLUSH, the transaction has + been committed implicitly. + */ + + if (thd->locked_tables_mode) + { + my_error(ER_LOCK_OR_ACTIVE_TRANSACTION, MYF(0)); + goto error; + } + + if (thd->current_backup_stage != BACKUP_FINISHED) + { + my_error(ER_BACKUP_LOCK_IS_ACTIVE, MYF(0)); + goto error; + } + + /* Should not flush tables while BACKUP LOCK is active */ + if (thd->mdl_backup_lock) + { + my_error(ER_LOCK_OR_ACTIVE_TRANSACTION, MYF(0)); + goto error; + } + + if (thd->lex->type & REFRESH_READ_LOCK) + { + /* + Acquire SNW locks on tables to be flushed. Don't acquire global + IX and database-scope IX locks on the tables as this will make + this statement incompatible with FLUSH TABLES WITH READ LOCK. + */ + if (lock_table_names(thd, all_tables, NULL, + thd->variables.lock_wait_timeout, + MYSQL_OPEN_SKIP_SCOPED_MDL_LOCK)) + goto error; + + DEBUG_SYNC(thd,"flush_tables_with_read_lock_after_acquire_locks"); + + /* Reset ticket to satisfy asserts in open_tables(). */ + for (auto table_list= all_tables; table_list; + table_list= table_list->next_global) + table_list->mdl_request.ticket= NULL; + } + + thd->variables.option_bits|= OPTION_TABLE_LOCK; + + /* + Before opening and locking tables the below call also waits + for old shares to go away, so the fact that we don't pass + MYSQL_OPEN_IGNORE_FLUSH flag to it is important. + Also we don't pass MYSQL_OPEN_HAS_MDL_LOCK flag as we want + to open underlying tables if merge table is flushed. + For underlying tables of the merge the below call has to + acquire SNW locks to ensure that they can be locked for + read without further waiting. + */ + if (open_and_lock_tables(thd, all_tables, FALSE, + MYSQL_OPEN_SKIP_SCOPED_MDL_LOCK, + &lock_tables_prelocking_strategy)) + goto error_reset_bits; + + if (thd->lex->type & REFRESH_FOR_EXPORT) + { + // Check if all storage engines support FOR EXPORT. + for (TABLE_LIST *table_list= all_tables; table_list; + table_list= table_list->next_global) + { + if (!(table_list->table->file->ha_table_flags() & HA_CAN_EXPORT)) + { + my_error(ER_ILLEGAL_HA, MYF(0),table_list->table->file->table_type(), + table_list->db.str, table_list->table_name.str); + goto error_reset_bits; + } + } + } + + if (thd->lex->type & REFRESH_READ_LOCK) + { + for (auto table_list= all_tables; table_list; + table_list= table_list->next_global) + { + if (table_list->table->file->extra(HA_EXTRA_FLUSH)) + goto error_reset_bits; + } + } + + if (thd->locked_tables_list.init_locked_tables(thd)) + goto error_reset_bits; + + + /* + We don't downgrade MDL_SHARED_NO_WRITE here as the intended + post effect of this call is identical to LOCK TABLES <...> READ, + and we didn't use thd->in_lock_talbes and + thd->sql_command= SQLCOM_LOCK_TABLES hacks to enter the LTM. + */ + + return FALSE; + +error_reset_bits: + trans_rollback_stmt(thd); + close_thread_tables(thd); + thd->variables.option_bits&= ~OPTION_TABLE_LOCK; +error: + return TRUE; +} + + +/** + Disable checkpoints for all handlers + This is released in unlock_global_read_lock() +*/ + +static void disable_checkpoints(THD *thd) +{ + if (!thd->global_disable_checkpoint) + { + thd->global_disable_checkpoint= 1; + if (!global_disable_checkpoint++) + ha_checkpoint_state(1); // Disable checkpoints + } +} |