Fix bug #54678, InnoDB, TRUNCATE, ALTER, I_S SELECT, crash or deadlock

rb://399 approved by Sunny Bains

storage/innodb_plugin/ChangeLog

+2010-08-03	The InnoDB Team
+
+	* include/dict0dict.h, include/dict0dict.ic, row/row0mysql.c:
+	Fix bug #54678, InnoDB, TRUNCATE, ALTER, I_S SELECT, crash or deadlock
+
 2010-08-03	The InnoDB Team
 
 	* dict/dict0load.c, handler/ha_innodb.cc, include/db0err.h,

storage/innodb_plugin/include/dict0dict.h

@@ -680,6 +680,22 @@ ulint
 dict_table_zip_size(
 /*================*/
 	const dict_table_t*	table);	/*!< in: table */
+/*********************************************************************//**
+Obtain exclusive locks on all index trees of the table. This is to prevent
+accessing index trees while InnoDB is updating internal metadata for
+operations such as truncate tables. */
+UNIV_INLINE
+void
+dict_table_x_lock_indexes(
+/*======================*/
+	dict_table_t*	table);	/*!< in: table */
+/*********************************************************************//**
+Release the exclusive locks on all index tree. */
+UNIV_INLINE
+void
+dict_table_x_unlock_indexes(
+/*========================*/
+	dict_table_t*	table);	/*!< in: table */
 /********************************************************************//**
 Checks if a column is in the ordering columns of the clustered index of a
 table. Column prefixes are treated like whole columns.

storage/innodb_plugin/include/dict0dict.ic

@@ -452,6 +452,48 @@ dict_table_zip_size(
 	return(dict_table_flags_to_zip_size(table->flags));
 }
 
+/*********************************************************************//**
+Obtain exclusive locks on all index trees of the table. This is to prevent
+accessing index trees while InnoDB is updating internal metadata for
+operations such as truncate tables. */
+UNIV_INLINE
+void
+dict_table_x_lock_indexes(
+/*======================*/
+	dict_table_t*	table)	/*!< in: table */
+{
+	dict_index_t*   index;
+
+	ut_a(table);
+	ut_ad(mutex_own(&(dict_sys->mutex)));
+
+	/* Loop through each index of the table and lock them */
+	for (index = dict_table_get_first_index(table);
+	     index != NULL;
+	     index = dict_table_get_next_index(index)) {
+		rw_lock_x_lock(dict_index_get_lock(index));
+	}
+}
+
+/*********************************************************************//**
+Release the exclusive locks on all index tree. */
+UNIV_INLINE
+void
+dict_table_x_unlock_indexes(
+/*========================*/
+	dict_table_t*	table)	/*!< in: table */
+{
+	dict_index_t*   index;
+
+	ut_a(table);
+	ut_ad(mutex_own(&(dict_sys->mutex)));
+
+	for (index = dict_table_get_first_index(table);
+	     index != NULL;
+	     index = dict_table_get_next_index(index)) {
+		rw_lock_x_unlock(dict_index_get_lock(index));
+	}
+}
 /********************************************************************//**
 Gets the number of fields in the internal representation of an index,
 including fields added by the dictionary system.

storage/innodb_plugin/row/row0mysql.c

@@ -2766,6 +2766,15 @@ row_truncate_table_for_mysql(
 
 	trx->table_id = table->id;
 
+	/* Lock all index trees for this table, as we will
+	truncate the table/index and possibly change their metadata.
+	All DML/DDL are blocked by table level lock, with
+	a few exceptions such as queries into information schema
+	about the table, MySQL could try to access index stats
+	for this kind of query, we need to use index locks to
+	sync up */
+	dict_table_x_lock_indexes(table);
+
 	if (table->space && !table->dir_path_of_temp_table) {
 		/* Discard and create the single-table tablespace. */
 		ulint	space	= table->space;
@@ -2782,6 +2791,7 @@ row_truncate_table_for_mysql(
 			    || fil_create_new_single_table_tablespace(
 				    space, table->name, FALSE, flags,
 				    FIL_IBD_FILE_INITIAL_SIZE) != DB_SUCCESS) {
+				dict_table_x_unlock_indexes(table);
 				ut_print_timestamp(stderr);
 				fprintf(stderr,
 					"  InnoDB: TRUNCATE TABLE %s failed to"
@@ -2885,6 +2895,10 @@ next_rec:
 
 	mem_heap_free(heap);
 
+	/* Done with index truncation, release index tree locks,
+	subsequent work relates to table level metadata change */
+	dict_table_x_unlock_indexes(table);
+
 	dict_hdr_get_new_id(&new_id, NULL, NULL);
 
 	info = pars_info_create();