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 9086c7639822b6
         ("tests/qemu-iotests: Rework the checks and spots using GNU
         sed")]
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

1 files changed, 8 insertions, 6 deletions

diff --git a/tests/qemu-iotests/testrunner.py b/tests/qemu-iotests/testrunner.py
index 0c7dc34a9e..41083ff9c6 100644
--- a/tests/qemu-iotests/testrunner.py
+++ b/tests/qemu-iotests/testrunner.py
@@ -259,9 +259,6 @@ class TestRunner(ContextManager['TestRunner']):
         """
 
         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 @@ class TestRunner(ContextManager['TestRunner']):
                               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 @@ class TestRunner(ContextManager['TestRunner']):
                 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,