aio: add regression test race between write and fcntl

perform AIO-DIO and fcntl(F_SETFL) concurently. Unaligned AIO likely
results in synchronization which makes the race window wider.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

tests/generic/036

@@ -0,0 +1,51 @@
+#! /bin/bash
+# FS QA Test No. 036
+#
+# CVE-2014-8086
+# Run aio-dio-fcntl-race - test aio write race with O_DIRECT toggle
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2014 Dmitry Monakhov.  All Rights Reserved.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it would be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write the Free Software Foundation,
+# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#-----------------------------------------------------------------------
+
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1	# failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+    cd /
+    rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# real QA test starts here
+
+_supported_fs generic
+_supported_os Linux
+_require_test
+
+_run_aiodio aio-dio-fcntl-race
+
+exit $status

tests/generic/036.out

@@ -0,0 +1,2 @@
+QA output created by 036
+All tasks are spawned

tests/generic/group

@@ -38,6 +38,7 @@
 033 auto quick rw
 034 auto quick metadata log
 035 auto quick
+036 auto aio rw stress
 053 acl repair auto quick
 062 attr udf auto quick
 068 other auto freeze dangerous stress