Commit 39eaefce authored by Alberto Garcia's avatar Alberto Garcia Committed by Max Reitz
Browse files

iotests: Tweak 030 in order to trigger a race condition with parallel jobs 



This patch tweaks TestParallelOps in iotest 030 so it allocates data
in smaller regions (256KB/512KB instead of 512KB/1MB) and the
block-stream job in test_stream_commit() only needs to copy data that
is at the very end of the image.

This way when the block-stream job is awakened it will finish right
away without any chance of being stopped by block_job_sleep_ns(). This
triggers the bug that was fixed by 3d5d319e and
1a63a907 and is therefore a more useful test
case for parallel block jobs.

After this patch the aforementiond bug can also be reproduced with the
test_stream_parallel() test case.

Since with this change the stream job in test_stream_commit() finishes
early, this patch introduces a similar test case where both jobs are
slowed down so they can actually run in parallel.

Signed-off-by: default avatarAlberto Garcia <berto@igalia.com>
Cc: John Snow <jsnow@redhat.com>
Message-id: 20180306130121.30243-1-berto@igalia.com
Signed-off-by: default avatarMax Reitz <mreitz@redhat.com>
parent 0bfed484

tests/qemu-iotests/030

+43 −9
Original line number Diff line number Diff line
@@ -156,7 +156,7 @@ class TestSingleDrive(iotests.QMPTestCase): 
class TestParallelOps(iotests.QMPTestCase):

    num_ops = 4 # Number of parallel block-stream operations

    num_imgs = num_ops * 2 + 1

    image_len = num_ops * 1024 * 1024

    image_len = num_ops * 512 * 1024

    imgs = []



    def setUp(self):
@@ -176,14 +176,14 @@ class TestParallelOps(iotests.QMPTestCase): 
                     '-o', 'backing_file=%s' % self.imgs[i-1], self.imgs[i])



        # Put data into the images we are copying data from

        for i in range(self.num_imgs / 2):

            img_index = i * 2 + 1

            # Alternate between 512k and 1M.

        odd_img_indexes = [x for x in reversed(range(self.num_imgs)) if x % 2 == 1]

        for i in range(len(odd_img_indexes)):

            # Alternate between 256KB and 512KB.

            # This way jobs will not finish in the same order they were created

            num_kb = 512 + 512 * (i % 2)

            num_kb = 256 + 256 * (i % 2)

            qemu_io('-f', iotests.imgfmt,

                    '-c', 'write -P %d %d %d' % (i, i*1024*1024, num_kb * 1024),

                    self.imgs[img_index])

                    '-c', 'write -P 0xFF %dk %dk' % (i * 512, num_kb),

                    self.imgs[odd_img_indexes[i]])



        # Attach the drive to the VM

        self.vm = iotests.VM()
@@ -318,12 +318,14 @@ class TestParallelOps(iotests.QMPTestCase): 
        self.wait_until_completed(drive='commit-drive0')



    # Test a block-stream and a block-commit job in parallel

    def test_stream_commit(self):

    # Here the stream job is supposed to finish quickly in order to reproduce

    # the scenario that triggers the bug fixed in 3d5d319e1221 and 1a63a907507

    def test_stream_commit_1(self):

        self.assertLessEqual(8, self.num_imgs)

        self.assert_no_active_block_jobs()



        # Stream from node0 into node2

        result = self.vm.qmp('block-stream', device='node2', job_id='node2')

        result = self.vm.qmp('block-stream', device='node2', base_node='node0', job_id='node2')

        self.assert_qmp(result, 'return', {})



        # Commit from the active layer into node3
@@ -348,6 +350,38 @@ class TestParallelOps(iotests.QMPTestCase): 


        self.assert_no_active_block_jobs()



    # This is similar to test_stream_commit_1 but both jobs are slowed

    # down so they can run in parallel for a little while.

    def test_stream_commit_2(self):

        self.assertLessEqual(8, self.num_imgs)

        self.assert_no_active_block_jobs()



        # Stream from node0 into node4

        result = self.vm.qmp('block-stream', device='node4', base_node='node0', job_id='node4', speed=1024*1024)

        self.assert_qmp(result, 'return', {})



        # Commit from the active layer into node5

        result = self.vm.qmp('block-commit', device='drive0', base=self.imgs[5], speed=1024*1024)

        self.assert_qmp(result, 'return', {})



        # Wait for all jobs to be finished.

        pending_jobs = ['node4', 'drive0']

        while len(pending_jobs) > 0:

            for event in self.vm.get_qmp_events(wait=True):

                if event['event'] == 'BLOCK_JOB_COMPLETED':

                    node_name = self.dictpath(event, 'data/device')

                    self.assertTrue(node_name in pending_jobs)

                    self.assert_qmp_absent(event, 'data/error')

                    pending_jobs.remove(node_name)

                if event['event'] == 'BLOCK_JOB_READY':

                    self.assert_qmp(event, 'data/device', 'drive0')

                    self.assert_qmp(event, 'data/type', 'commit')

                    self.assert_qmp_absent(event, 'data/error')

                    self.assertTrue('drive0' in pending_jobs)

                    self.vm.qmp('block-job-complete', device='drive0')



        self.assert_no_active_block_jobs()



    # Test the base_node parameter

    def test_stream_base_node_name(self):

        self.assert_no_active_block_jobs()

tests/qemu-iotests/030.out

+2 −2
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Ran 23 tests

Ran 24 tests



OK