branches/zip: Do not release the data dictionary latch while holding locks

to the data dictionary records.  This should fix Issue #83.

row_drop_table_for_mysql_no_commit(): Rename back to
row_drop_table_for_mysql().  Commit the transaction if the data
dictionary was not locked when the function was called.  Otherwise,
neither commit the transaction nor unlock the data dictionary.

row_merge_drop_table(): Let row_drop_table_for_mysql() take care of
locking the data dictionary.

dict_create_or_check_foreign_constraint_tables(),
trx_rollback_active(), row_create_table_for_mysql(),
row_create_index_for_mysql(), row_table_add_foreign_constraints():
Explicitly commit the transaction, because row_drop_table_for_mysql()
would no longer commit it, given that the data dictionary will be
locked during the calls.

Approved by Sunny (over IM). rb://23

ChangeLog

+2008-10-08	The InnoDB Team
+
+	* dict/dict0crea.c, trx/trx0roll.c, include/row0mysql.h,
+	row/row0merge.c, row/row0mysql.c: When dropping a table, hold the
+	data dictionary latch until the transaction has been committed.
+	The data dictionary latch is supposed to prevent lock waits and
+	deadlocks in the data dictionary tables.  Due to this bug,
+	DROP TABLE could cause a deadlock or hang.  Note that because of
+	Bug#33650 and Bug#39833, MySQL may also drop a (temporary) table
+	when executing CREATE INDEX or ALTER TABLE ... ADD INDEX.
+
 2008-10-04	The InnoDB Team
 
 	* handler/ha_innodb.cc, mysql-test/innodb_bug39438-master.opt,

dict/dict0crea.c

@@ -1225,7 +1225,6 @@ dict_create_or_check_foreign_constraint_tables(void)
 			     " FOR_COL_NAME CHAR, REF_COL_NAME CHAR);\n"
 			     "CREATE UNIQUE CLUSTERED INDEX ID_IND"
 			     " ON SYS_FOREIGN_COLS (ID, POS);\n"
-			     "COMMIT WORK;\n"
 			     "END;\n"
 			     , FALSE, trx);
 
@@ -1248,7 +1247,7 @@ dict_create_or_check_foreign_constraint_tables(void)
 		error = DB_MUST_GET_MORE_FILE_SPACE;
 	}
 
-	trx->op_info = "";
+	trx_commit_for_mysql(trx);
 
 	row_mysql_unlock_data_dictionary(trx);
 

include/row0mysql.h

@@ -411,10 +411,12 @@ row_truncate_table_for_mysql(
 	dict_table_t*	table,	/* in: table handle */
 	trx_t*		trx);	/* in: transaction handle */
 /*************************************************************************
-Drops a table for MySQL. If the name of the dropped table ends in
+Drops a table for MySQL.  If the name of the dropped table ends in
 one of "innodb_monitor", "innodb_lock_monitor", "innodb_tablespace_monitor",
 "innodb_table_monitor", then this will also stop the printing of monitor
-output by the master thread. */
+output by the master thread.  If the data dictionary was not already locked
+by the transaction, the transaction will be committed.  Otherwise, the
+data dictionary will remain locked. */
 UNIV_INTERN
 int
 row_drop_table_for_mysql(
@@ -425,20 +427,6 @@ row_drop_table_for_mysql(
 	ibool		drop_db);/* in: TRUE=dropping whole database */
 
 /*************************************************************************
-Drops a table for MySQL but does not commit the transaction.  If the
-name of the dropped table ends in one of "innodb_monitor",
-"innodb_lock_monitor", "innodb_tablespace_monitor",
-"innodb_table_monitor", then this will also stop the printing of
-monitor output by the master thread. */
-UNIV_INTERN
-int
-row_drop_table_for_mysql_no_commit(
-/*===============================*/
-				/* out: error code or DB_SUCCESS */
-	const char*	name,	/* in: table name */
-	trx_t*		trx,	/* in: transaction handle */
-	ibool		drop_db);/* in: TRUE=dropping whole database */
-/*************************************************************************
 Discards the tablespace of a table which stored in an .ibd file. Discarding
 means that this function deletes the .ibd file and assigns a new table id for
 the table. Also the flag table->ibd_file_missing is set TRUE. */

row/row0merge.c

@@ -2218,24 +2218,10 @@ row_merge_drop_table(
 	trx_t*		trx,		/* in: transaction */
 	dict_table_t*	table)		/* in: table to drop */
 {
-	ulint		err = DB_SUCCESS;
-	ibool		dict_locked = FALSE;
-
-	if (trx->dict_operation_lock_mode == 0) {
-		row_mysql_lock_data_dictionary(trx);
-		dict_locked = TRUE;
-	}
-
 	/* There must be no open transactions on the table. */
 	ut_a(table->n_mysql_handles_opened == 0);
 
-	err = row_drop_table_for_mysql_no_commit(table->name, trx, FALSE);
-
-	if (dict_locked) {
-		row_mysql_unlock_data_dictionary(trx);
-	}
-
-	return(err);
+	return(row_drop_table_for_mysql(table->name, trx, FALSE));
 }
 
 /*************************************************************************

row/row0mysql.c

@@ -1850,6 +1850,7 @@ err_exit:
 		if (dict_table_get_low(table->name)) {
 
 			row_drop_table_for_mysql(table->name, trx, FALSE);
+			trx_commit_for_mysql(trx);
 		}
 		break;
 
@@ -2007,6 +2008,8 @@ error_handling:
 
 		row_drop_table_for_mysql(table_name, trx, FALSE);
 
+		trx_commit_for_mysql(trx);
+
 		trx->error_state = DB_SUCCESS;
 	}
 
@@ -2074,6 +2077,8 @@ row_table_add_foreign_constraints(
 
 		row_drop_table_for_mysql(name, trx, FALSE);
 
+		trx_commit_for_mysql(trx);
+
 		trx->error_state = DB_SUCCESS;
 	}
 
@@ -2933,10 +2938,12 @@ funct_exit:
 }
 
 /*************************************************************************
-Drops a table for MySQL. If the name of the dropped table ends in
+Drops a table for MySQL.  If the name of the dropped table ends in
 one of "innodb_monitor", "innodb_lock_monitor", "innodb_tablespace_monitor",
 "innodb_table_monitor", then this will also stop the printing of monitor
-output by the master thread. */
+output by the master thread.  If the data dictionary was not already locked
+by the transaction, the transaction will be committed.  Otherwise, the
+data dictionary will remain locked. */
 UNIV_INTERN
 int
 row_drop_table_for_mysql(
@@ -2945,29 +2952,6 @@ row_drop_table_for_mysql(
 	const char*	name,	/* in: table name */
 	trx_t*		trx,	/* in: transaction handle */
 	ibool		drop_db)/* in: TRUE=dropping whole database */
-{
-	ulint		err;
-
-	err = row_drop_table_for_mysql_no_commit(name, trx, drop_db);
-	trx_commit_for_mysql(trx);
-
-	return(err);
-}
-
-/*************************************************************************
-Drops a table for MySQL but does not commit the transaction.  If the
-name of the dropped table ends in one of "innodb_monitor",
-"innodb_lock_monitor", "innodb_tablespace_monitor",
-"innodb_table_monitor", then this will also stop the printing of
-monitor output by the master thread. */
-UNIV_INTERN
-int
-row_drop_table_for_mysql_no_commit(
-/*===============================*/
-				/* out: error code or DB_SUCCESS */
-	const char*	name,	/* in: table name */
-	trx_t*		trx,	/* in: transaction handle */
-	ibool		drop_db)/* in: TRUE=dropping whole database */
 {
 	dict_foreign_t*	foreign;
 	dict_table_t*	table;
@@ -3336,6 +3320,8 @@ check_next_foreign:
 funct_exit:
 
 	if (locked_dictionary) {
+		trx_commit_for_mysql(trx);
+
 		row_mysql_unlock_data_dictionary(trx);
 	}
 

trx/trx0roll.c

@@ -506,6 +506,7 @@ trx_rollback_active(
 			fputs(" in recovery\n", stderr);
 
 			err = row_drop_table_for_mysql(table->name, trx, TRUE);
+			trx_commit_for_mysql(trx);
 
 			ut_a(err == (int) DB_SUCCESS);
 		}