[Qemu-block] [PATCH] iotests: Fix intermittent failure in 219

[Max Reitz]

In 219, we wait for the job to make progress before we emit its status.
This makes the output reliable.

Unfortunately, there is a bug: We do not wait for any more progress if
the job has already reached its total-progress.  Right after the job has
been started, it is possible that total-progress is still 0, though.  In
that case, we may skip the first progress-making step and keep ending up
64 kB short.

To fix that bug, we cab simply wait for total-progress to reach 4 MB
(the image size) after starting the job.

Reported-by: Karen Mezick <address@hidden>
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1686651
Signed-off-by: Max Reitz <address@hidden>
---
 tests/qemu-iotests/219 | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/tests/qemu-iotests/219 b/tests/qemu-iotests/219
index c03bbdb294..e0c51662c0 100755
--- a/tests/qemu-iotests/219
+++ b/tests/qemu-iotests/219
@@ -23,6 +23,8 @@ import iotests
 
 iotests.verify_image_format(supported_fmts=['qcow2'])
 
+img_size = 4 * 1024 * 1024
+
 def pause_wait(vm, job_id):
     with iotests.Timeout(3, "Timeout waiting for job to pause"):
         while True:
@@ -62,6 +64,8 @@ def test_pause_resume(vm):
                 iotests.log(vm.qmp('query-jobs'))
 
 def test_job_lifecycle(vm, job, job_args, has_ready=False):
+    global img_size
+
     iotests.log('')
     iotests.log('')
     iotests.log('Starting block job: %s (auto-finalize: %s; auto-dismiss: %s)' 
%
@@ -84,6 +88,10 @@ def test_job_lifecycle(vm, job, job_args, has_ready=False):
     iotests.log(iotests.filter_qmp_event(vm.event_wait('JOB_STATUS_CHANGE')))
     iotests.log(iotests.filter_qmp_event(vm.event_wait('JOB_STATUS_CHANGE')))
 
+    # Wait for total-progress to stabilize
+    while vm.qmp('query-jobs')['return'][0]['total-progress'] < img_size:
+        pass
+
     # RUNNING state:
     # pause/resume should work, complete/finalize/dismiss should error out
     iotests.log('')
@@ -173,9 +181,8 @@ with iotests.FilePath('disk.img') as disk_path, \
      iotests.FilePath('copy.img') as copy_path, \
      iotests.VM() as vm:
 
-    img_size = '4M'
-    iotests.qemu_img_create('-f', iotests.imgfmt, disk_path, img_size)
-    iotests.qemu_io('-c', 'write 0 %s' % (img_size),
+    iotests.qemu_img_create('-f', iotests.imgfmt, disk_path, str(img_size))
+    iotests.qemu_io('-c', 'write 0 %i' % (img_size),
                     '-f', iotests.imgfmt, disk_path)
 
     iotests.log('Launching VM...')
-- 
2.21.0