iotests: Add test for QMP event rates

This test verifies that the rate-limited QMP events are emitted at a
maximum rate of 1 per second as defined in monitor_qapi_event_conf in
monitor.c

It also checks that QUORUM_REPORT_BAD events generated from different
nodes are kept in separate queues so they don't mask each other.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 0dbd3ee88a59a6363042ad81cfb345037bfbf612.1457610443.git.berto@igalia.com
[mreitz@redhat.com: Renamed test from 146 to 148]
Signed-off-by: Max Reitz <mreitz@redhat.com>

tests/qemu-iotests/148

@@ -0,0 +1,129 @@
+#!/usr/bin/env python
+#
+# Test the rate limit of QMP events
+#
+# Copyright (C) 2016 Igalia, S.L.
+# Author: Alberto Garcia <berto@igalia.com>
+#
+# 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; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will 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, see <http://www.gnu.org/licenses/>.
+#
+
+import os
+import iotests
+
+imgs = (os.path.join(iotests.test_dir, 'quorum0.img'),
+        os.path.join(iotests.test_dir, 'quorum1.img'),
+        os.path.join(iotests.test_dir, 'quorum2.img'))
+
+img_conf = (os.path.join(iotests.test_dir, 'quorum0.conf'),
+            os.path.join(iotests.test_dir, 'quorum1.conf'),
+            os.path.join(iotests.test_dir, 'quorum2.conf'))
+
+event_rate = 1000000000
+sector_size = 512
+offset = 10
+
+class TestQuorumEvents(iotests.QMPTestCase):
+
+    def create_blkdebug_file(self, blkdebug_file, bad_sector):
+        file = open(blkdebug_file, 'w')
+        file.write('''
+[inject-error]
+event = "read_aio"
+errno = "5"
+sector = "%d"
+''' % bad_sector)
+        file.close()
+
+    def setUp(self):
+        driveopts = ['driver=quorum', 'vote-threshold=2']
+        for i in range(len(imgs)):
+            iotests.qemu_img('create', '-f', iotests.imgfmt, imgs[i], '1M')
+            self.create_blkdebug_file(img_conf[i], i + offset)
+            driveopts.append('children.%d.driver=%s' % (i, iotests.imgfmt))
+            driveopts.append('children.%d.file.driver=blkdebug' % i)
+            driveopts.append('children.%d.file.config=%s' % (i, img_conf[i]))
+            driveopts.append('children.%d.file.image.filename=%s' % (i, imgs[i]))
+            driveopts.append('children.%d.node-name=img%d' % (i, i))
+        self.vm = iotests.VM()
+        self.vm.add_drive(None, opts = ','.join(driveopts))
+        self.vm.launch()
+
+    def tearDown(self):
+        self.vm.shutdown()
+        for i in range(len(imgs)):
+            os.remove(imgs[i])
+            os.remove(img_conf[i])
+
+    def do_check_event(self, node, sector = 0):
+        if node == None:
+            self.assertEqual(self.vm.get_qmp_event(), None)
+            return
+
+        for event in self.vm.get_qmp_events(wait=True):
+            if event['event'] == 'QUORUM_REPORT_BAD':
+                self.assert_qmp(event, 'data/node-name', node)
+                self.assert_qmp(event, 'data/sector-num', sector)
+
+    def testQuorum(self):
+        if not 'quorum' in iotests.qemu_img_pipe('--help'):
+            return
+
+        # Generate an error and get an event
+        self.vm.hmp_qemu_io("drive0", "aio_read %d %d" %
+                            (offset * sector_size, sector_size))
+        self.vm.qtest("clock_step 10")
+        self.do_check_event('img0', offset)
+
+        # I/O errors in the same child: only one event is emitted
+        delay = 10
+        for i in range(3):
+            self.vm.hmp_qemu_io("drive0", "aio_read %d %d" %
+                                (offset * sector_size, sector_size))
+            self.vm.qtest("clock_step %d" % delay)
+            self.do_check_event(None)
+
+        # Wait enough so the event is finally emitted
+        self.vm.qtest("clock_step %d" % (2 * event_rate))
+        self.do_check_event('img0', offset)
+
+        # I/O errors in the same child: all events are emitted
+        delay = 2 * event_rate
+        for i in range(3):
+            self.vm.hmp_qemu_io("drive0", "aio_read %d %d" %
+                                (offset * sector_size, sector_size))
+            self.vm.qtest("clock_step %d" % delay)
+            self.do_check_event('img0', offset)
+
+        # I/O errors in different children: all events are emitted
+        delay = 10
+        for i in range(len(imgs)):
+            self.vm.hmp_qemu_io("drive0", "aio_read %d %d" %
+                                ((offset + i) * sector_size, sector_size))
+            self.vm.qtest("clock_step %d" % delay)
+            self.do_check_event('img%d' % i, offset + i)
+
+        # I/O errors in different children: all events are emitted
+        delay = 2 * event_rate
+        for i in range(len(imgs)):
+            self.vm.hmp_qemu_io("drive0", "aio_read %d %d" %
+                                ((offset + i) * sector_size, sector_size))
+            self.vm.qtest("clock_step %d" % delay)
+            self.do_check_event('img%d' % i, offset + i)
+
+        # No more pending events
+        self.do_check_event(None)
+
+if __name__ == '__main__':
+    iotests.main(supported_fmts=["raw"])

tests/qemu-iotests/148.out

@@ -0,0 +1,5 @@
+.
+----------------------------------------------------------------------
+Ran 1 tests
+
+OK

tests/qemu-iotests/group

@@ -149,3 +149,4 @@
 144 rw auto quick
 145 auto quick
 146 auto quick
+148 rw auto quick