is_shared_mount
ASSERT_EQ(is_shared_mount("/mnt/A"), true);
ASSERT_EQ(is_shared_mount("/mnt/A/AA"), true);
ASSERT_EQ(is_shared_mount("/mnt/A/AA/B"), true);
ASSERT_EQ(is_shared_mount("/mnt/A/AA/B/BB"), true);
ASSERT_EQ(is_shared_mount("/mnt/A"), true);
ASSERT_EQ(is_shared_mount("/mnt/A/AA"), true);
ASSERT_EQ(is_shared_mount("/mnt/A/AA/B"), true);
ASSERT_EQ(is_shared_mount("/mnt/A/AA/B/BB"), true);
ASSERT_EQ(is_shared_mount("/mnt/A"), false);
ASSERT_EQ(is_shared_mount("/mnt/A/AA"), false);
ASSERT_EQ(is_shared_mount("/mnt/A/AA/B"), false);
ASSERT_EQ(is_shared_mount("/mnt/A/AA/B/BB"), false);
ASSERT_EQ(is_shared_mount("/mnt/A"), true);
ASSERT_EQ(is_shared_mount("/mnt/A/AA"), true);
ASSERT_EQ(is_shared_mount("/mnt/A/AA/B"), true);
ASSERT_EQ(is_shared_mount("/mnt/A/AA/B/BB"), true);
ASSERT_EQ(is_shared_mount(SET_GROUP_A), 1);