Re: [PATCH for-7.2 4/5] iotests/151: Test that active mirror progresses

[Kevin Wolf]

Am 09.11.2022 um 17:54 hat Hanna Reitz geschrieben:
> Before this series, a mirror job in write-blocking mode would pause
> issuing background requests while active requests are in flight.  Thus,
> if the source is constantly in use by active requests, no actual
> progress can be made.
> 
> This series should have fixed that, making the mirror job issue
> background requests even while active requests are in flight.
> 
> Have a new test case in 151 verify this.
> 
> Signed-off-by: Hanna Reitz 

Reviewed-by: Kevin Wolf 

[PATCH for-7.2 4/5] iotests/151: Test that active mirror progresses

[Hanna Reitz]

Before this series, a mirror job in write-blocking mode would pause
issuing background requests while active requests are in flight.  Thus,
if the source is constantly in use by active requests, no actual
progress can be made.

This series should have fixed that, making the mirror job issue
background requests even while active requests are in flight.

Have a new test case in 151 verify this.

Signed-off-by: Hanna Reitz 
---
 tests/qemu-iotests/151 | 180 -
 tests/qemu-iotests/151.out |   4 +-
 2 files changed, 181 insertions(+), 3 deletions(-)

diff --git a/tests/qemu-iotests/151 b/tests/qemu-iotests/151
index 93d14193d0..0a052e5050 100755
--- a/tests/qemu-iotests/151
+++ b/tests/qemu-iotests/151
@@ -19,7 +19,10 @@
 # along with this program.  If not, see .
 #
 
+import math
 import os
+import subprocess
+from typing import List
 import iotests
 from iotests import qemu_img
 
@@ -50,7 +53,7 @@ class TestActiveMirror(iotests.QMPTestCase):
 self.vm = iotests.VM()
 self.vm.add_drive_raw(self.vm.qmp_to_opts(blk_source))
 self.vm.add_blockdev(self.vm.qmp_to_opts(blk_target))
-self.vm.add_device('virtio-blk,drive=source')
+self.vm.add_device('virtio-blk,id=vblk,drive=source')
 self.vm.launch()
 
 def tearDown(self):
@@ -192,6 +195,181 @@ class TestActiveMirror(iotests.QMPTestCase):
 self.potential_writes_in_flight = False
 
 
+class TestThrottledWithNbdExport(iotests.QMPTestCase):
+image_len = 128 * 1024 * 1024  # MB
+iops = 16
+background_processes: List['subprocess.Popen[str]'] = []
+
+def setUp(self):
+qemu_img('create', '-f', iotests.imgfmt, source_img, '128M')
+qemu_img('create', '-f', iotests.imgfmt, target_img, '128M')
+
+self.vm = iotests.VM()
+self.vm.launch()
+
+result = self.vm.qmp('object-add', **{
+'qom-type': 'throttle-group',
+'id': 'thrgr',
+'limits': {
+'iops-total': self.iops,
+'iops-total-max': self.iops
+}
+})
+self.assert_qmp(result, 'return', {})
+
+result = self.vm.qmp('blockdev-add', **{
+'node-name': 'source-node',
+'driver': 'throttle',
+'throttle-group': 'thrgr',
+'file': {
+'driver': iotests.imgfmt,
+'file': {
+'driver': 'file',
+'filename': source_img
+}
+}
+})
+self.assert_qmp(result, 'return', {})
+
+result = self.vm.qmp('blockdev-add', **{
+'node-name': 'target-node',
+'driver': iotests.imgfmt,
+'file': {
+'driver': 'file',
+'filename': target_img
+}
+})
+self.assert_qmp(result, 'return', {})
+
+self.nbd_sock = iotests.file_path('nbd.sock',
+  base_dir=iotests.sock_dir)
+self.nbd_url = f'nbd+unix:///source-node?socket={self.nbd_sock}'
+
+result = self.vm.qmp('nbd-server-start', addr={
+'type': 'unix',
+'data': {
+'path': self.nbd_sock
+}
+})
+self.assert_qmp(result, 'return', {})
+
+result = self.vm.qmp('block-export-add', id='exp0', type='nbd',
+ node_name='source-node', writable=True)
+self.assert_qmp(result, 'return', {})
+
+def tearDown(self):
+# Wait for background requests to settle
+try:
+while True:
+p = self.background_processes.pop()
+while True:
+try:
+p.wait(timeout=0.0)
+break
+except subprocess.TimeoutExpired:
+self.vm.qtest(f'clock_step {1 * 1000 * 1000 * 1000}')
+except IndexError:
+pass
+
+# Cancel ongoing block jobs
+for job in self.vm.qmp('query-jobs')['return']:
+self.vm.qmp('block-job-cancel', device=job['id'], force=True)
+
+while True:
+self.vm.qtest(f'clock_step {1 * 1000 * 1000 * 1000}')
+if len(self.vm.qmp('query-jobs')['return']) == 0:
+break
+
+self.vm.shutdown()
+os.remove(source_img)
+os.remove(target_img)
+
+def testUnderLoad(self):
+'''
+Throttle the source node, then issue a whole bunch of external requests
+while the mirror job (in write-blocking mode) is running.  We want to
+see background requests being issued even while the source is under
+full load by active writes, so that progress can be made towards READY.
+'''
+
+# Fill the first half of the source image; do not fill the second half,
+# that is where we will have active requests occur.  This ensures that
+