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From:   =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= <ilpo.jarvinen@linux.intel.com>
To:     linux-kselftest@vger.kernel.org,
        Reinette Chatre <reinette.chatre@intel.com>,
        Shuah Khan <shuah@kernel.org>,
        Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>,
        Fenghua Yu <fenghua.yu@intel.com>,
        Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>,
        linux-kernel@vger.kernel.org
Cc:     =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= <ilpo.jarvinen@linux.intel.com>
Subject: [PATCH v5 05/19] selftests/resctrl: Unmount resctrl FS before starting the first test
Date:   Mon, 17 Jul 2023 16:14:53 +0300
Message-Id: <20230717131507.32420-6-ilpo.jarvinen@linux.intel.com>
In-Reply-To: <20230717131507.32420-1-ilpo.jarvinen@linux.intel.com>
References: <20230717131507.32420-1-ilpo.jarvinen@linux.intel.com>
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Precedence: bulk

Resctrl FS mount/remount/umount code is hard to track. Better approach
is to use mount/umount pair for each test but that assumes resctrl FS
is not mounted beforehand.

Change umount_resctrlfs() so that it can unmount resctrl FS from any
path, and enable further simplifications into mount/remount/umount
logic by unmounting resctrl FS at the start if a pre-existing
mountpoint is found.

Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 tools/testing/selftests/resctrl/resctrl_tests.c |  3 +++
 tools/testing/selftests/resctrl/resctrlfs.c     | 10 ++++++++--
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c
index 9b9751206e1c..61c3882a26c8 100644
--- a/tools/testing/selftests/resctrl/resctrl_tests.c
+++ b/tools/testing/selftests/resctrl/resctrl_tests.c
@@ -250,6 +250,9 @@ int main(int argc, char **argv)
 	if (!check_resctrlfs_support())
 		return ksft_exit_skip("resctrl FS does not exist. Enable X86_CPU_RESCTRL config option.\n");
 
+	if (umount_resctrlfs())
+		return ksft_exit_skip("resctrl FS unmount failed.\n");
+
 	filter_dmesg();
 
 	ksft_set_plan(tests ? : 4);
diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
index fb00245dee92..cf0c8dd34b8b 100644
--- a/tools/testing/selftests/resctrl/resctrlfs.c
+++ b/tools/testing/selftests/resctrl/resctrlfs.c
@@ -82,10 +82,16 @@ int remount_resctrlfs(bool mum_resctrlfs)
 
 int umount_resctrlfs(void)
 {
-	if (find_resctrl_mount(NULL))
+	char mountpoint[256];
+	int ret;
+
+	ret = find_resctrl_mount(mountpoint);
+	if (ret == -ENOENT)
 		return 0;
+	if (ret)
+		return ret;
 
-	if (umount(RESCTRL_PATH)) {
+	if (umount(mountpoint)) {
 		perror("# Unable to umount resctrl");
 
 		return errno;
-- 
2.30.2