selftests/damon: test quota goals directory

Add DAMON selftests for testing creation/existence of quota goals
directories and files, and simple valid input writes.

Link: https://lkml.kernel.org/r/20231130023652.50284-7-sj@kernel.orgSigned-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Gow <davidgow@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

tools/testing/selftests/damon/sysfs.sh

@@ -150,6 +150,32 @@ test_weights()
 	ensure_file "$weights_dir/age_permil" "exist" "600"
 }
 
+test_goal()
+{
+	goal_dir=$1
+	ensure_dir "$goal_dir" "exist"
+	ensure_file "$goal_dir/target_value" "exist" "600"
+	ensure_file "$goal_dir/current_value" "exist" "600"
+}
+
+test_goals()
+{
+	goals_dir=$1
+	ensure_dir "$goals_dir" "exist"
+	ensure_file "$goals_dir/nr_goals" "exist" "600"
+
+	ensure_write_succ  "$goals_dir/nr_goals" "1" "valid input"
+	test_goal "$goals_dir/0"
+
+	ensure_write_succ  "$goals_dir/nr_goals" "2" "valid input"
+	test_goal "$goals_dir/0"
+	test_goal "$goals_dir/1"
+
+	ensure_write_succ  "$goals_dir/nr_goals" "0" "valid input"
+	ensure_dir "$goals_dir/0" "not_exist"
+	ensure_dir "$goals_dir/1" "not_exist"
+}
+
 test_quotas()
 {
 	quotas_dir=$1
@@ -158,6 +184,7 @@ test_quotas()
 	ensure_file "$quotas_dir/bytes" "exist" 600
 	ensure_file "$quotas_dir/reset_interval_ms" "exist" 600
 	test_weights "$quotas_dir/weights"
+	test_goals "$quotas_dir/goals"
 }
 
 test_access_pattern()