Merge remote-tracking branch 'remotes/maxreitz/tags/pull-block-2021-05-14' into staging

Block patches:
- drop block/io write notifiers
- qemu-iotests enhancements to make debugging easier
- rbd parsing fix
- HMP qemu-io fix (for iothreads)
- mirror job cancel relaxation (do not cancel in-flight requests when a
  READY mirror job is canceled with force=false)
- document qcow2's data_file and data_file_raw features
- fix iotest 297 for pylint 2.8
- block/copy-on-read refactoring

# gpg: Signature made Fri 14 May 2021 17:43:40 BST
# gpg:                using RSA key 91BEB60A30DB3E8857D11829F407DB0061D5CF40
# gpg:                issuer "mreitz@redhat.com"
# gpg: Good signature from "Max Reitz <mreitz@redhat.com>" [full]
# Primary key fingerprint: 91BE B60A 30DB 3E88 57D1  1829 F407 DB00 61D5 CF40

* remotes/maxreitz/tags/pull-block-2021-05-14:
  write-threshold: deal with includes
  test-write-threshold: drop extra TestStruct structure
  test-write-threshold: drop extra tests
  block/write-threshold: drop extra APIs
  test-write-threshold: rewrite test_threshold_(not_)trigger tests
  block: drop write notifiers
  block/write-threshold: don't use write notifiers
  qemu-iotests: fix pylint 2.8 consider-using-with error
  block/copy-on-read: use bdrv_drop_filter() and drop s->active
  Document qemu-img options data_file and data_file_raw
  qemu-iotests: fix case of SOCK_DIR already in the environment
  qemu-iotests: let "check" spawn an arbitrary test command
  qemu-iotests: move command line and environment handling from TestRunner to TestEnv
  qemu-iotests: allow passing unittest.main arguments to the test scripts
  qemu-iotests: do not buffer the test output
  mirror: stop cancelling in-flight requests on non-force cancel in READY
  monitor: hmp_qemu_io: acquire aio contex, fix crash
  block/rbd: Add an escape-aware strchr helper
  iotests/231: Update expected deprecation message

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

13 files changed, 164 insertions, 195 deletions

diff --git a/tests/qemu-iotests/231 b/tests/qemu-iotests/231
index 0f66d0c..8e6c644 100755
--- a/tests/qemu-iotests/231
+++ b/tests/qemu-iotests/231
@@ -55,6 +55,10 @@ _filter_conf()
 $QEMU_IMG info "json:{'file.driver':'rbd','file.filename':'rbd:rbd/bogus:conf=${BOGUS_CONF}'}" 2>&1 | _filter_conf
 $QEMU_IMG info "json:{'file.driver':'rbd','file.pool':'rbd','file.image':'bogus','file.conf':'${BOGUS_CONF}'}" 2>&1 | _filter_conf
 
+# Regression test: the qemu-img invocation is expected to fail, but it should
+# not seg fault the parser.
+$QEMU_IMG create "rbd:rbd/aa\/bb:conf=${BOGUS_CONF}" 1M 2>&1 | _filter_conf
+
 # success, all done
 echo "*** done"
 rm -f $seq.full
diff --git a/tests/qemu-iotests/231.out b/tests/qemu-iotests/231.out
index 579ba11..a785a6e 100644
--- a/tests/qemu-iotests/231.out
+++ b/tests/qemu-iotests/231.out
@@ -1,9 +1,10 @@
 QA output created by 231
-qemu-img: RBD options encoded in the filename as keyvalue pairs is deprecated.  Future versions may cease to parse these options in the future.
+qemu-img: warning: RBD options encoded in the filename as keyvalue pairs is deprecated
 unable to get monitor info from DNS SRV with service name: ceph-mon
-no monitors specified to connect to.
 qemu-img: Could not open 'json:{'file.driver':'rbd','file.filename':'rbd:rbd/bogus:conf=BOGUS_CONF'}': error connecting: No such file or directory
 unable to get monitor info from DNS SRV with service name: ceph-mon
-no monitors specified to connect to.
 qemu-img: Could not open 'json:{'file.driver':'rbd','file.pool':'rbd','file.image':'bogus','file.conf':'BOGUS_CONF'}': error connecting: No such file or directory
+Formatting 'rbd:rbd/aa\/bb:conf=BOGUS_CONF', fmt=raw size=1048576
+unable to get monitor info from DNS SRV with service name: ceph-mon
+qemu-img: rbd:rbd/aa\/bb:conf=BOGUS_CONF: error connecting: No such file or directory
 *** done
diff --git a/tests/qemu-iotests/240.out b/tests/qemu-iotests/240.out
index e098283..89ed25e 100644
--- a/tests/qemu-iotests/240.out
+++ b/tests/qemu-iotests/240.out
@@ -15,7 +15,7 @@
 {"return": {}}
 {"execute": "blockdev-del", "arguments": {"node-name": "hd0"}}
 {"return": {}}
-==Attach two SCSI disks using the same block device and the same iothread==
+.==Attach two SCSI disks using the same block device and the same iothread==
 {"execute": "blockdev-add", "arguments": {"driver": "null-co", "node-name": "hd0", "read-only": true, "read-zeroes": true}}
 {"return": {}}
 {"execute": "object-add", "arguments": {"id": "iothread0", "qom-type": "iothread"}}
@@ -32,7 +32,7 @@
 {"return": {}}
 {"execute": "blockdev-del", "arguments": {"node-name": "hd0"}}
 {"return": {}}
-==Attach two SCSI disks using the same block device but different iothreads==
+.==Attach two SCSI disks using the same block device but different iothreads==
 {"execute": "blockdev-add", "arguments": {"driver": "null-co", "node-name": "hd0", "read-only": true, "read-zeroes": true}}
 {"return": {}}
 {"execute": "object-add", "arguments": {"id": "iothread0", "qom-type": "iothread"}}
@@ -55,7 +55,7 @@
 {"return": {}}
 {"execute": "blockdev-del", "arguments": {"node-name": "hd0"}}
 {"return": {}}
-==Attach a SCSI disks using the same block device as a NBD server==
+.==Attach a SCSI disks using the same block device as a NBD server==
 {"execute": "blockdev-add", "arguments": {"driver": "null-co", "node-name": "hd0", "read-only": true, "read-zeroes": true}}
 {"return": {}}
 {"execute": "nbd-server-start", "arguments": {"addr": {"data": {"path": "SOCK_DIR/PID-nbd.sock"}, "type": "unix"}}}
@@ -68,7 +68,7 @@
 {"return": {}}
 {"execute": "device_add", "arguments": {"drive": "hd0", "driver": "scsi-hd", "id": "scsi-hd0"}}
 {"return": {}}
-....
+.
 ----------------------------------------------------------------------
 Ran 4 tests
 
diff --git a/tests/qemu-iotests/245.out b/tests/qemu-iotests/245.out
index 4b33dca..99c12f4 100644
--- a/tests/qemu-iotests/245.out
+++ b/tests/qemu-iotests/245.out
@@ -1,16 +1,16 @@
-{"execute": "job-finalize", "arguments": {"id": "commit0"}}
+..{"execute": "job-finalize", "arguments": {"id": "commit0"}}
 {"return": {}}
 {"data": {"id": "commit0", "type": "commit"}, "event": "BLOCK_JOB_PENDING", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 {"data": {"device": "commit0", "len": 3145728, "offset": 3145728, "speed": 0, "type": "commit"}, "event": "BLOCK_JOB_COMPLETED", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
-{"execute": "job-finalize", "arguments": {"id": "stream0"}}
+...{"execute": "job-finalize", "arguments": {"id": "stream0"}}
 {"return": {}}
 {"data": {"id": "stream0", "type": "stream"}, "event": "BLOCK_JOB_PENDING", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 {"data": {"device": "stream0", "len": 3145728, "offset": 3145728, "speed": 0, "type": "stream"}, "event": "BLOCK_JOB_COMPLETED", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
-{"execute": "job-finalize", "arguments": {"id": "stream0"}}
+.{"execute": "job-finalize", "arguments": {"id": "stream0"}}
 {"return": {}}
 {"data": {"id": "stream0", "type": "stream"}, "event": "BLOCK_JOB_PENDING", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 {"data": {"device": "stream0", "len": 3145728, "offset": 3145728, "speed": 0, "type": "stream"}, "event": "BLOCK_JOB_COMPLETED", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
-.....................
+...............
 ----------------------------------------------------------------------
 Ran 21 tests
 
diff --git a/tests/qemu-iotests/264 b/tests/qemu-iotests/264
index 4f96825..bc431d1 100755
--- a/tests/qemu-iotests/264
+++ b/tests/qemu-iotests/264
@@ -95,7 +95,7 @@ class TestNbdReconnect(iotests.QMPTestCase):
             self.assert_qmp(result, 'return', {})
 
     def cancel_job(self):
-        result = self.vm.qmp('block-job-cancel', device='drive0')
+        result = self.vm.qmp('block-job-cancel', device='drive0', force=True)
         self.assert_qmp(result, 'return', {})
 
         start_t = time.time()
diff --git a/tests/qemu-iotests/295.out b/tests/qemu-iotests/295.out
index ad34b2c..5ff91f1 100644
--- a/tests/qemu-iotests/295.out
+++ b/tests/qemu-iotests/295.out
@@ -4,7 +4,7 @@
 {"return": {}}
 {"execute": "job-dismiss", "arguments": {"id": "job_erase_key"}}
 {"return": {}}
-{"execute": "job-dismiss", "arguments": {"id": "job_add_key"}}
+.{"execute": "job-dismiss", "arguments": {"id": "job_add_key"}}
 {"return": {}}
 {"execute": "job-dismiss", "arguments": {"id": "job_erase_key"}}
 {"return": {}}
@@ -13,7 +13,7 @@ Job failed: Invalid password, cannot unlock any keyslot
 {"return": {}}
 {"execute": "job-dismiss", "arguments": {"id": "job_add_key"}}
 {"return": {}}
-{"execute": "job-dismiss", "arguments": {"id": "job_add_key"}}
+.{"execute": "job-dismiss", "arguments": {"id": "job_add_key"}}
 {"return": {}}
 {"execute": "job-dismiss", "arguments": {"id": "job_add_key"}}
 {"return": {}}
@@ -33,7 +33,7 @@ Job failed: All the active keyslots match the (old) password that was given and
 {"return": {}}
 {"execute": "job-dismiss", "arguments": {"id": "job_erase_key"}}
 {"return": {}}
-...
+.
 ----------------------------------------------------------------------
 Ran 3 tests
 
diff --git a/tests/qemu-iotests/296.out b/tests/qemu-iotests/296.out
index cb2859a..6c69735 100644
--- a/tests/qemu-iotests/296.out
+++ b/tests/qemu-iotests/296.out
@@ -13,7 +13,7 @@ Job failed: Failed to get shared "consistent read" lock
 qemu-img: Failed to get shared "consistent read" lock
 Is another process using the image [TEST_DIR/test.img]?
 
-Formatting 'TEST_DIR/test.img', fmt=luks size=1048576 key-secret=keysec0 iter-time=10
+.Formatting 'TEST_DIR/test.img', fmt=luks size=1048576 key-secret=keysec0 iter-time=10
 
 Job failed: Block node is read-only
 {"execute": "job-dismiss", "arguments": {"id": "job0"}}
@@ -26,15 +26,15 @@ Job failed: Failed to get shared "consistent read" lock
 {"return": {}}
 {"execute": "job-dismiss", "arguments": {"id": "job0"}}
 {"return": {}}
-Formatting 'TEST_DIR/test.img', fmt=luks size=1048576 key-secret=keysec0 iter-time=10
+.Formatting 'TEST_DIR/test.img', fmt=luks size=1048576 key-secret=keysec0 iter-time=10
 
 {"return": {}}
 {"error": {"class": "GenericError", "desc": "Failed to get \"write\" lock"}}
-Formatting 'TEST_DIR/test.img', fmt=luks size=1048576 key-secret=keysec0 iter-time=10
+.Formatting 'TEST_DIR/test.img', fmt=luks size=1048576 key-secret=keysec0 iter-time=10
 
 {"return": {}}
 {"return": {}}
-....
+.
 ----------------------------------------------------------------------
 Ran 4 tests
 
diff --git a/tests/qemu-iotests/check b/tests/qemu-iotests/check
index 08f5136..2dd529e 100755
--- a/tests/qemu-iotests/check
+++ b/tests/qemu-iotests/check
@@ -19,6 +19,9 @@
 import os
 import sys
 import argparse
+import shutil
+from pathlib import Path
+
 from findtests import TestFinder
 from testenv import TestEnv
 from testrunner import TestRunner
@@ -100,7 +103,7 @@ def make_argparser() -> argparse.ArgumentParser:
                        'rerun failed ./check command, starting from the '
                        'middle of the process.')
     g_sel.add_argument('tests', metavar='TEST_FILES', nargs='*',
-                       help='tests to run')
+                       help='tests to run, or "--" followed by a command')
 
     return p
 
@@ -113,6 +116,20 @@ if __name__ == '__main__':
                   imgopts=args.imgopts, misalign=args.misalign,
                   debug=args.debug, valgrind=args.valgrind)
 
+    if len(sys.argv) > 1 and sys.argv[-len(args.tests)-1] == '--':
+        if not args.tests:
+            sys.exit("missing command after '--'")
+        cmd = args.tests
+        env.print_env()
+        exec_pathstr = shutil.which(cmd[0])
+        if exec_pathstr is None:
+            sys.exit('command not found: ' + cmd[0])
+        exec_path = Path(exec_pathstr).resolve()
+        cmd[0] = str(exec_path)
+        full_env = env.prepare_subprocess(cmd)
+        os.chdir(exec_path.parent)
+        os.execve(cmd[0], cmd, full_env)
+
     testfinder = TestFinder(test_dir=env.source_iotests)
 
     groups = args.groups.split(',') if args.groups else None
diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index 5af0182..777fa2e 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -20,7 +20,6 @@ import atexit
 import bz2
 from collections import OrderedDict
 import faulthandler
-import io
 import json
 import logging
 import os
@@ -32,7 +31,7 @@ import subprocess
 import sys
 import time
 from typing import (Any, Callable, Dict, Iterable,
-                    List, Optional, Sequence, Tuple, TypeVar)
+                    List, Optional, Sequence, TextIO, Tuple, Type, TypeVar)
 import unittest
 
 from contextlib import contextmanager
@@ -113,15 +112,14 @@ def qemu_tool_pipe_and_status(tool: str, args: Sequence[str],
     Run a tool and return both its output and its exit code
     """
     stderr = subprocess.STDOUT if connect_stderr else None
-    subp = subprocess.Popen(args,
-                            stdout=subprocess.PIPE,
-                            stderr=stderr,
-                            universal_newlines=True)
-    output = subp.communicate()[0]
-    if subp.returncode < 0:
-        cmd = ' '.join(args)
-        sys.stderr.write(f'{tool} received signal {-subp.returncode}: {cmd}\n')
-    return (output, subp.returncode)
+    with subprocess.Popen(args, stdout=subprocess.PIPE,
+                          stderr=stderr, universal_newlines=True) as subp:
+        output = subp.communicate()[0]
+        if subp.returncode < 0:
+            cmd = ' '.join(args)
+            sys.stderr.write(f'{tool} received signal \
+                               {-subp.returncode}: {cmd}\n')
+        return (output, subp.returncode)
 
 def qemu_img_pipe_and_status(*args: str) -> Tuple[str, int]:
     """
@@ -237,6 +235,9 @@ def qemu_io_silent_check(*args):
 class QemuIoInteractive:
     def __init__(self, *args):
         self.args = qemu_io_args_no_fmt + list(args)
+        # We need to keep the Popen objext around, and not
+        # close it immediately. Therefore, disable the pylint check:
+        # pylint: disable=consider-using-with
         self._p = subprocess.Popen(self.args, stdin=subprocess.PIPE,
                                    stdout=subprocess.PIPE,
                                    stderr=subprocess.STDOUT,
@@ -310,22 +311,22 @@ def qemu_nbd_popen(*args):
     cmd.extend(args)
 
     log('Start NBD server')
-    p = subprocess.Popen(cmd)
-    try:
-        while not os.path.exists(pid_file):
-            if p.poll() is not None:
-                raise RuntimeError(
-                    "qemu-nbd terminated with exit code {}: {}"
-                    .format(p.returncode, ' '.join(cmd)))
-
-            time.sleep(0.01)
-        yield
-    finally:
-        if os.path.exists(pid_file):
-            os.remove(pid_file)
-        log('Kill NBD server')
-        p.kill()
-        p.wait()
+    with subprocess.Popen(cmd) as p:
+        try:
+            while not os.path.exists(pid_file):
+                if p.poll() is not None:
+                    raise RuntimeError(
+                        "qemu-nbd terminated with exit code {}: {}"
+                        .format(p.returncode, ' '.join(cmd)))
+
+                time.sleep(0.01)
+            yield
+        finally:
+            if os.path.exists(pid_file):
+                os.remove(pid_file)
+            log('Kill NBD server')
+            p.kill()
+            p.wait()
 
 def compare_images(img1, img2, fmt1=imgfmt, fmt2=imgfmt):
     '''Return True if two image files are identical'''
@@ -334,13 +335,12 @@ def compare_images(img1, img2, fmt1=imgfmt, fmt2=imgfmt):
 
 def create_image(name, size):
     '''Create a fully-allocated raw image with sector markers'''
-    file = open(name, 'wb')
-    i = 0
-    while i < size:
-        sector = struct.pack('>l504xl', i // 512, i // 512)
-        file.write(sector)
-        i = i + 512
-    file.close()
+    with open(name, 'wb') as file:
+        i = 0
+        while i < size:
+            sector = struct.pack('>l504xl', i // 512, i // 512)
+            file.write(sector)
+            i = i + 512
 
 def image_size(img):
     '''Return image's virtual size'''
@@ -1271,37 +1271,54 @@ def skip_if_user_is_root(func):
             return func(*args, **kwargs)
     return func_wrapper
 
-def execute_unittest(debug=False):
+# We need to filter out the time taken from the output so that
+# qemu-iotest can reliably diff the results against master output,
+# and hide skipped tests from the reference output.
+
+class ReproducibleTestResult(unittest.TextTestResult):
+    def addSkip(self, test, reason):
+        # Same as TextTestResult, but print dot instead of "s"
+        unittest.TestResult.addSkip(self, test, reason)
+        if self.showAll:
+            self.stream.writeln("skipped {0!r}".format(reason))
+        elif self.dots:
+            self.stream.write(".")
+            self.stream.flush()
+
+class ReproducibleStreamWrapper:
+    def __init__(self, stream: TextIO):
+        self.stream = stream
+
+    def __getattr__(self, attr):
+        if attr in ('stream', '__getstate__'):
+            raise AttributeError(attr)
+        return getattr(self.stream, attr)
+
+    def write(self, arg=None):
+        arg = re.sub(r'Ran (\d+) tests? in [\d.]+s', r'Ran \1 tests', arg)
+        arg = re.sub(r' \(skipped=\d+\)', r'', arg)
+        self.stream.write(arg)
+
+class ReproducibleTestRunner(unittest.TextTestRunner):
+    def __init__(self, stream: Optional[TextIO] = None,
+             resultclass: Type[unittest.TestResult] = ReproducibleTestResult,
+             **kwargs: Any) -> None:
+        rstream = ReproducibleStreamWrapper(stream or sys.stdout)
+        super().__init__(stream=rstream,           # type: ignore
+                         descriptions=True,
+                         resultclass=resultclass,
+                         **kwargs)
+
+def execute_unittest(argv: List[str], debug: bool = False) -> None:
     """Executes unittests within the calling module."""
 
-    verbosity = 2 if debug else 1
-
-    if debug:
-        output = sys.stdout
-    else:
-        # We need to filter out the time taken from the output so that
-        # qemu-iotest can reliably diff the results against master output.
-        output = io.StringIO()
-
-    runner = unittest.TextTestRunner(stream=output, descriptions=True,
-                                     verbosity=verbosity)
-    try:
-        # unittest.main() will use sys.exit(); so expect a SystemExit
-        # exception
-        unittest.main(testRunner=runner)
-    finally:
-        # We need to filter out the time taken from the output so that
-        # qemu-iotest can reliably diff the results against master output.
-        if not debug:
-            out = output.getvalue()
-            out = re.sub(r'Ran (\d+) tests? in [\d.]+s', r'Ran \1 tests', out)
-
-            # Hide skipped tests from the reference output
-            out = re.sub(r'OK \(skipped=\d+\)', 'OK', out)
-            out_first_line, out_rest = out.split('\n', 1)
-            out = out_first_line.replace('s', '.') + '\n' + out_rest
-
-            sys.stderr.write(out)
+    # Some tests have warnings, especially ResourceWarnings for unclosed
+    # files and sockets.  Ignore them for now to ensure reproducibility of
+    # the test output.
+    unittest.main(argv=argv,
+                  testRunner=ReproducibleTestRunner,
+                  verbosity=2 if debug else 1,
+                  warnings=None if sys.warnoptions else 'ignore')
 
 def execute_setup_common(supported_fmts: Sequence[str] = (),
                          supported_platforms: Sequence[str] = (),
@@ -1338,7 +1355,7 @@ def execute_test(*args, test_function=None, **kwargs):
 
     debug = execute_setup_common(*args, **kwargs)
     if not test_function:
-        execute_unittest(debug)
+        execute_unittest(sys.argv, debug)
     else:
         test_function()
 
diff --git a/tests/qemu-iotests/pylintrc b/tests/qemu-iotests/pylintrc
index 7a6c0a9..f2c0b52 100644
--- a/tests/qemu-iotests/pylintrc
+++ b/tests/qemu-iotests/pylintrc
@@ -19,6 +19,9 @@ disable=invalid-name,
         too-many-public-methods,
         # pylint warns about Optional[] etc. as unsubscriptable in 3.9
         unsubscriptable-object,
+        # Sometimes we need to disable a newly introduced pylint warning.
+        # Doing so should not produce a warning in older versions of pylint.
+        bad-option-value,
         # These are temporary, and should be removed:
         missing-docstring,
         too-many-return-statements,
diff --git a/tests/qemu-iotests/testenv.py b/tests/qemu-iotests/testenv.py
index 6d27712..0c3fe75 100644
--- a/tests/qemu-iotests/testenv.py
+++ b/tests/qemu-iotests/testenv.py
@@ -25,7 +25,7 @@ import collections
 import random
 import subprocess
 import glob
-from typing import Dict, Any, Optional, ContextManager
+from typing import List, Dict, Any, Optional, ContextManager
 
 
 def isxfile(path: str) -> bool:
@@ -74,6 +74,21 @@ class TestEnv(ContextManager['TestEnv']):
                      'CACHEMODE_IS_DEFAULT', 'IMGFMT_GENERIC', 'IMGOPTSSYNTAX',
                      'IMGKEYSECRET', 'QEMU_DEFAULT_MACHINE', 'MALLOC_PERTURB_']
 
+    def prepare_subprocess(self, args: List[str]) -> Dict[str, str]:
+        if self.debug:
+            args.append('-d')
+
+        with open(args[0], encoding="utf-8") as f:
+            try:
+                if f.readline().rstrip() == '#!/usr/bin/env python3':
+                    args.insert(0, self.python)
+            except UnicodeDecodeError:  # binary test? for future.
+                pass
+
+        os_env = os.environ.copy()
+        os_env.update(self.get_env())
+        return os_env
+
     def get_env(self) -> Dict[str, str]:
         env = {}
         for v in self.env_variables:
@@ -105,7 +120,7 @@ class TestEnv(ContextManager['TestEnv']):
         try:
             self.sock_dir = os.environ['SOCK_DIR']
             self.tmp_sock_dir = False
-            Path(self.test_dir).mkdir(parents=True, exist_ok=True)
+            Path(self.sock_dir).mkdir(parents=True, exist_ok=True)
         except KeyError:
             self.sock_dir = tempfile.mkdtemp()
             self.tmp_sock_dir = True
@@ -269,7 +284,8 @@ IMGPROTO      -- {IMGPROTO}
 PLATFORM      -- {platform}
 TEST_DIR      -- {TEST_DIR}
 SOCK_DIR      -- {SOCK_DIR}
-SOCKET_SCM_HELPER -- {SOCKET_SCM_HELPER}"""
+SOCKET_SCM_HELPER -- {SOCKET_SCM_HELPER}
+"""
 
         args = collections.defaultdict(str, self.get_env())
 
diff --git a/tests/qemu-iotests/testrunner.py b/tests/qemu-iotests/testrunner.py
index 1fc61fc..4a6ec42 100644
--- a/tests/qemu-iotests/testrunner.py
+++ b/tests/qemu-iotests/testrunner.py
@@ -129,7 +129,6 @@ class TestRunner(ContextManager['TestRunner']):
     def __init__(self, env: TestEnv, makecheck: bool = False,
                  color: str = 'auto') -> None:
         self.env = env
-        self.test_run_env = self.env.get_env()
         self.makecheck = makecheck
         self.last_elapsed = LastElapsedTime('.last-elapsed-cache', env)
 
@@ -243,32 +242,21 @@ class TestRunner(ContextManager['TestRunner']):
             silent_unlink(p)
 
         args = [str(f_test.resolve())]
-        if self.env.debug:
-            args.append('-d')
-
-        with f_test.open(encoding="utf-8") as f:
-            try:
-                if f.readline().rstrip() == '#!/usr/bin/env python3':
-                    args.insert(0, self.env.python)
-            except UnicodeDecodeError:  # binary test? for future.
-                pass
-
-        env = os.environ.copy()
-        env.update(self.test_run_env)
+        env = self.env.prepare_subprocess(args)
 
         t0 = time.time()
         with f_bad.open('w', encoding="utf-8") as f:
-            proc = subprocess.Popen(args, cwd=str(f_test.parent), env=env,
-                                    stdout=f, stderr=subprocess.STDOUT)
-            try:
-                proc.wait()
-            except KeyboardInterrupt:
-                proc.terminate()
-                proc.wait()
-                return TestResult(status='not run',
-                                  description='Interrupted by user',
-                                  interrupted=True)
-            ret = proc.returncode
+            with subprocess.Popen(args, cwd=str(f_test.parent), env=env,
+                                  stdout=f, stderr=subprocess.STDOUT) as proc:
+                try:
+                    proc.wait()
+                except KeyboardInterrupt:
+                    proc.terminate()
+                    proc.wait()
+                    return TestResult(status='not run',
+                                      description='Interrupted by user',
+                                      interrupted=True)
+                ret = proc.returncode
 
         elapsed = round(time.time() - t0, 1)
 
@@ -328,7 +316,6 @@ class TestRunner(ContextManager['TestRunner']):
 
         if not self.makecheck:
             self.env.print_env()
-            print()
 
         test_field_width = max(len(os.path.basename(t)) for t in tests) + 2
 
diff --git a/tests/unit/test-write-threshold.c b/tests/unit/test-write-threshold.c
index fc1c45a..0158e46 100644
--- a/tests/unit/test-write-threshold.c
+++ b/tests/unit/test-write-threshold.c
@@ -7,117 +7,41 @@
  */
 
 #include "qemu/osdep.h"
-#include "qapi/error.h"
 #include "block/block_int.h"
 #include "block/write-threshold.h"
 
 
-static void test_threshold_not_set_on_init(void)
-{
-    uint64_t res;
-    BlockDriverState bs;
-    memset(&bs, 0, sizeof(bs));
-
-    g_assert(!bdrv_write_threshold_is_set(&bs));
-
-    res = bdrv_write_threshold_get(&bs);
-    g_assert_cmpint(res, ==, 0);
-}
-
-static void test_threshold_set_get(void)
-{
-    uint64_t threshold = 4 * 1024 * 1024;
-    uint64_t res;
-    BlockDriverState bs;
-    memset(&bs, 0, sizeof(bs));
-
-    bdrv_write_threshold_set(&bs, threshold);
-
-    g_assert(bdrv_write_threshold_is_set(&bs));
-
-    res = bdrv_write_threshold_get(&bs);
-    g_assert_cmpint(res, ==, threshold);
-}
-
-static void test_threshold_multi_set_get(void)
-{
-    uint64_t threshold1 = 4 * 1024 * 1024;
-    uint64_t threshold2 = 15 * 1024 * 1024;
-    uint64_t res;
-    BlockDriverState bs;
-    memset(&bs, 0, sizeof(bs));
-
-    bdrv_write_threshold_set(&bs, threshold1);
-    bdrv_write_threshold_set(&bs, threshold2);
-    res = bdrv_write_threshold_get(&bs);
-    g_assert_cmpint(res, ==, threshold2);
-}
-
 static void test_threshold_not_trigger(void)
 {
-    uint64_t amount = 0;
     uint64_t threshold = 4 * 1024 * 1024;
     BlockDriverState bs;
-    BdrvTrackedRequest req;
 
     memset(&bs, 0, sizeof(bs));
-    memset(&req, 0, sizeof(req));
-    req.offset = 1024;
-    req.bytes = 1024;
-
-    bdrv_check_request(req.offset, req.bytes, &error_abort);
 
     bdrv_write_threshold_set(&bs, threshold);
-    amount = bdrv_write_threshold_exceeded(&bs, &req);
-    g_assert_cmpuint(amount, ==, 0);
+    bdrv_write_threshold_check_write(&bs, 1024, 1024);
+    g_assert_cmpuint(bdrv_write_threshold_get(&bs), ==, threshold);
 }
 
 
 static void test_threshold_trigger(void)
 {
-    uint64_t amount = 0;
     uint64_t threshold = 4 * 1024 * 1024;
     BlockDriverState bs;
-    BdrvTrackedRequest req;
 
     memset(&bs, 0, sizeof(bs));
-    memset(&req, 0, sizeof(req));
-    req.offset = (4 * 1024 * 1024) - 1024;
-    req.bytes = 2 * 1024;
-
-    bdrv_check_request(req.offset, req.bytes, &error_abort);
 
     bdrv_write_threshold_set(&bs, threshold);
-    amount = bdrv_write_threshold_exceeded(&bs, &req);
-    g_assert_cmpuint(amount, >=, 1024);
+    bdrv_write_threshold_check_write(&bs, threshold - 1024, 2 * 1024);
+    g_assert_cmpuint(bdrv_write_threshold_get(&bs), ==, 0);
 }
 
-typedef struct TestStruct {
-    const char *name;
-    void (*func)(void);
-} TestStruct;
-
 
 int main(int argc, char **argv)
 {
-    size_t i;
-    TestStruct tests[] = {
-        { "/write-threshold/not-set-on-init",
-          test_threshold_not_set_on_init },
-        { "/write-threshold/set-get",
-          test_threshold_set_get },
-        { "/write-threshold/multi-set-get",
-          test_threshold_multi_set_get },
-        { "/write-threshold/not-trigger",
-          test_threshold_not_trigger },
-        { "/write-threshold/trigger",
-          test_threshold_trigger },
-        { NULL, NULL }
-    };
-
     g_test_init(&argc, &argv, NULL);
-    for (i = 0; tests[i].name != NULL; i++) {
-        g_test_add_func(tests[i].name, tests[i].func);
-    }
+    g_test_add_func("/write-threshold/not-trigger", test_threshold_not_trigger);
+    g_test_add_func("/write-threshold/trigger", test_threshold_trigger);
+
     return g_test_run();
 }