Merge lp:~akopytov/percona-server/bug1247305-5.5 into lp:percona-server/5.5

[Alexey Kopytov]

    Bug #1247305: InnoDB: Assertion failure in thread <nr> in file trx0trx.c
                  line 180

    Acquire kernel_mutex to satisfy a debug assertion in
    trx_release_descriptor() when calling it from
    trx_cleanup_at_db_startup().

http://jenkins.percona.com/view/PS%205.5/job/percona-server-5.5-param/893/

[Vlad Lesin (vlad-lesin)]

review: Approve (g2)

=== modified file 'Percona-Server/storage/innobase/trx/trx0trx.c'
--- Percona-Server/storage/innobase/trx/trx0trx.c	2013-09-06 13:24:59 +0000
+++ Percona-Server/storage/innobase/trx/trx0trx.c	2013-11-05 13:24:28 +0000
@@ -1306,7 +1306,15 @@
 	}
 
 	trx->state = TRX_NOT_STARTED;
+
+	/* This code is executed in a single threaded context, but we acquire
+	kernel_mutex to satisfy a debug assertion in
+	trx_release_descriptor(). */
+
+	mutex_enter(&kernel_mutex);
 	trx_release_descriptor(trx);
+	mutex_exit(&kernel_mutex);
+
 	trx->rseg = NULL;
 	trx->undo_no = 0;
 	trx->last_sql_stat_start.least_undo_no = 0;