r2629 | inaam | 2008-09-16 18:46:00 +0300 (Tue, 16 Sep 2008) | 9 lines

branches/5.0   bug#39483 InnoDB hang on adaptive hash because of out
of order ::open() call by MySQL

Under some conditions MySQL calls ::open with search_latch leading
to a deadlock as we try to acquire dict_sys->mutex inside ::open
breaking the latching order. The fix is to release search_latch.

Reviewed by: Heikki

sql/ha_innodb.cc

@@ -2158,6 +2158,14 @@ ha_innobase::open(
 	UT_NOT_USED(test_if_locked);
 
 	thd = current_thd;
+
+	/* Under some cases MySQL seems to call this function while
+	holding btr_search_latch. This breaks the latching order as
+	we acquire dict_sys->mutex below and leads to a deadlock. */
+	if (thd != NULL) {
+		innobase_release_temporary_latches(thd);
+	}
+
 	normalize_table_name(norm_name, name);
 
 	user_thd = NULL;