[PATCH 03/10] selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts

[SeongJae Park <sj@kernel.org>]

_damon_sysfs.py assumes sysfs is mounted at /sys.  In some systems, that
might not be true.  Find the mount point from /proc/mounts file content.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 tools/testing/selftests/damon/_damon_sysfs.py | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/damon/_damon_sysfs.py b/tools/testing/selftests/damon/_damon_sysfs.py
index fffa74a78bd7..5367e98817a9 100644
--- a/tools/testing/selftests/damon/_damon_sysfs.py
+++ b/tools/testing/selftests/damon/_damon_sysfs.py
@@ -2,7 +2,18 @@
 
 import os
 
-sysfs_root = '/sys/kernel/mm/damon/admin'
+ksft_skip=4
+
+sysfs_root = None
+with open('/proc/mounts', 'r') as f:
+    for line in f:
+        dev_name, mount_point, dev_fs = line.split()[:3]
+        if dev_fs == 'sysfs':
+            sysfs_root = '%s/kernel/mm/damon/admin' % mount_point
+            break
+if sysfs_root is None:
+    print('Seems sysfs not mounted?')
+    exit(ksft_skip)
 
 def write_file(path, string):
     "Returns error string if failed, or None otherwise"
-- 
2.39.2