Apply InnoDB snapshot innodb-5.1-ss2858, part 4. Fixes

Bug #39438: Testcase for Bug#39436 crashes on 5.1 in fil_space_get_latch


Detailed revision comments:

r2719 | vasil | 2008-10-03 18:17:28 +0300 (Fri, 03 Oct 2008) | 49 lines
branches/5.1:

Fix Bug#39438 Testcase for Bug#39436 crashes on 5.1 in fil_space_get_latch

In ha_innobase::info() - do not try to get the free space for a tablespace
which has been discarded with ALTER TABLE ... DISCARD TABLESPACE or if the
.ibd file is missing for some other reason.

ibd_file_missing and tablespace_discarded are manipulated only in
row_discard_tablespace_for_mysql() and in row_import_tablespace_for_mysql()
and the manipulation is protected/surrounded by
row_mysql_lock_data_dictionary()/row_mysql_unlock_data_dictionary() thus we
do the same in ha_innobase::info() when checking the values of those members
to avoid race conditions. I have tested the code-path with UNIV_DEBUG and
UNIV_SYNC_DEBUG.

rb://20

Reviewed by:	Inaam, Calvin
Approved by:	Heikki

mysql-test/t/innodb_bug39438.test

@@ -0,0 +1,27 @@
+#
+# Bug#39438 Testcase for Bug#39436 crashes on 5.1 in fil_space_get_latch
+# http://bugs.mysql.com/39438
+#
+# This test must be run with innodb_file_per_table=1 because the crash
+# only occurs if that option is turned on and DISCARD TABLESPACE only
+# works with innodb_file_per_table.
+#
+
+-- source include/have_innodb.inc
+
+SET storage_engine=InnoDB;
+
+# we care only that the following SQL commands do not crash the server
+-- disable_query_log
+-- disable_result_log
+
+DROP TABLE IF EXISTS bug39438;
+
+CREATE TABLE bug39438 (id INT) ENGINE=INNODB;
+
+ALTER TABLE bug39438 DISCARD TABLESPACE;
+
+# this crashes the server if the bug is present
+SHOW TABLE STATUS;
+
+DROP TABLE bug39438;