iotests: Write test output to TEST_DIR

Drop the use of OUTPUT_DIR (test/qemu-iotests under the build
directory), and instead write test output files (.out.bad, .notrun, and
.casenotrun) to TEST_DIR.

With this, the same test can be run concurrently without the separate
instances interfering, because they will need separate TEST_DIRs anyway.
Running the same test separately is useful when running the iotests with
various format/protocol combinations in parallel, or when you just want
to aggressively exercise a single test (e.g. when it fails only
sporadically).

Putting this output into TEST_DIR means that it will stick around for
inspection after the test run is done (though running the same test in
the same TEST_DIR will overwrite it, just as it used to be); but given
that TEST_DIR is a scratch directory, it should be clear that users can
delete all of its content at any point.  (And if TEST_DIR is on tmpfs,
it will just disappear on shutdown.)  Contrarily, alternative approaches
that would put these output files into OUTPUT_DIR with some prefix to
differentiate between separate test runs might easily lead to cluttering
OUTPUT_DIR.

(This change means OUTPUT_DIR is no longer written to by the iotests, so
we can drop its usage altogether.)

Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220221172909.762858-1-hreitz@redhat.com>
[hreitz: Simplified `Path(os.path.join(x, y))` to `Path(x, y)`, as
         suggested by Vladimir; and rebased on 9086c76
         ("tests/qemu-iotests: Rework the checks and spots using GNU
         sed")]
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

tests/qemu-iotests/common.rc

@@ -20,7 +20,7 @@
 # bail out, setting up .notrun file
 _notrun()
 {
-    echo "$*" >"$OUTPUT_DIR/$seq.notrun"
+    echo "$*" >"$TEST_DIR/$seq.notrun"
     echo "$seq not run: $*"
     status=0
     exit
@@ -739,14 +739,14 @@ _img_info()
 #
 _casenotrun()
 {
-    echo "    [case not run] $*" >>"$OUTPUT_DIR/$seq.casenotrun"
+    echo "    [case not run] $*" >>"$TEST_DIR/$seq.casenotrun"
 }
 
 # just plain bail out
 #
 _fail()
 {
-    echo "$*" | tee -a "$OUTPUT_DIR/$seq.full"
+    echo "$*" | tee -a "$TEST_DIR/$seq.full"
     echo "(see $seq.full for details)"
     status=1
     exit 1

tests/qemu-iotests/iotests.py

@@ -85,7 +85,6 @@
 
 imgfmt = os.environ.get('IMGFMT', 'raw')
 imgproto = os.environ.get('IMGPROTO', 'file')
-output_dir = os.environ.get('OUTPUT_DIR', '.')
 
 try:
     test_dir = os.environ['TEST_DIR']
@@ -1239,7 +1238,7 @@ def notrun(reason):
     # Each test in qemu-iotests has a number ("seq")
     seq = os.path.basename(sys.argv[0])
 
-    with open('%s/%s.notrun' % (output_dir, seq), 'w', encoding='utf-8') \
+    with open('%s/%s.notrun' % (test_dir, seq), 'w', encoding='utf-8') \
             as outfile:
         outfile.write(reason + '\n')
     logger.warning("%s not run: %s", seq, reason)
@@ -1254,7 +1253,7 @@ def case_notrun(reason):
     # Each test in qemu-iotests has a number ("seq")
     seq = os.path.basename(sys.argv[0])
 
-    with open('%s/%s.casenotrun' % (output_dir, seq), 'a', encoding='utf-8') \
+    with open('%s/%s.casenotrun' % (test_dir, seq), 'a', encoding='utf-8') \
             as outfile:
         outfile.write('    [case not run] ' + reason + '\n')
 

tests/qemu-iotests/testenv.py

@@ -66,7 +66,7 @@ class TestEnv(ContextManager['TestEnv']):
     # pylint: disable=too-many-instance-attributes
 
     env_variables = ['PYTHONPATH', 'TEST_DIR', 'SOCK_DIR', 'SAMPLE_IMG_DIR',
-                     'OUTPUT_DIR', 'PYTHON', 'QEMU_PROG', 'QEMU_IMG_PROG',
+                     'PYTHON', 'QEMU_PROG', 'QEMU_IMG_PROG',
                      'QEMU_IO_PROG', 'QEMU_NBD_PROG', 'QSD_PROG',
                      'QEMU_OPTIONS', 'QEMU_IMG_OPTIONS',
                      'QEMU_IO_OPTIONS', 'QEMU_IO_OPTIONS_NO_FMT',
@@ -106,7 +106,6 @@ def init_directories(self) -> None:
              TEST_DIR
              SOCK_DIR
              SAMPLE_IMG_DIR
-             OUTPUT_DIR
         """
 
         # Path where qemu goodies live in this source tree.
@@ -134,8 +133,6 @@ def init_directories(self) -> None:
                                         os.path.join(self.source_iotests,
                                                      'sample_images'))
 
-        self.output_dir = os.getcwd()  # OUTPUT_DIR
-
     def init_binaries(self) -> None:
         """Init binary path variables:
              PYTHON (for bash tests)

tests/qemu-iotests/testrunner.py

@@ -259,9 +259,6 @@ def do_run_test(self, test: str, mp: bool) -> TestResult:
         """
 
         f_test = Path(test)
-        f_bad = Path(f_test.name + '.out.bad')
-        f_notrun = Path(f_test.name + '.notrun')
-        f_casenotrun = Path(f_test.name + '.casenotrun')
         f_reference = Path(self.find_reference(test))
 
         if not f_test.exists():
@@ -276,9 +273,6 @@ def do_run_test(self, test: str, mp: bool) -> TestResult:
                               description='No qualified output '
                                           f'(expected {f_reference})')
 
-        for p in (f_bad, f_notrun, f_casenotrun):
-            silent_unlink(p)
-
         args = [str(f_test.resolve())]
         env = self.env.prepare_subprocess(args)
         if mp:
@@ -288,6 +282,14 @@ def do_run_test(self, test: str, mp: bool) -> TestResult:
                 env[d] = os.path.join(env[d], f_test.name)
                 Path(env[d]).mkdir(parents=True, exist_ok=True)
 
+        test_dir = env['TEST_DIR']
+        f_bad = Path(test_dir, f_test.name + '.out.bad')
+        f_notrun = Path(test_dir, f_test.name + '.notrun')
+        f_casenotrun = Path(test_dir, f_test.name + '.casenotrun')
+
+        for p in (f_notrun, f_casenotrun):
+            silent_unlink(p)
+
         t0 = time.time()
         with f_bad.open('w', encoding="utf-8") as f:
             with subprocess.Popen(args, cwd=str(f_test.parent), env=env,