Re: [PATCH bpf-next v3 8/9] selftests/bpf: Make sure mount directory exists

[Martin KaFai Lau <martin.lau@xxxxxxxxx>]

On 8/29/23 3:18 AM, Daan De Meyer wrote:
> The mount directory for the selftests cgroup tree might
> not exist so let's make sure it does exist by creating
> it ourselves if it doesn't exist.
>
> Signed-off-by: Daan De Meyer <daan.j.demeyer@xxxxxxxxx>
> ---
>   tools/testing/selftests/bpf/cgroup_helpers.c | 5 +++++
>   1 file changed, 5 insertions(+)
>
> diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c
> index 2caee8423ee0..860043d473fd 100644
> --- a/tools/testing/selftests/bpf/cgroup_helpers.c
> +++ b/tools/testing/selftests/bpf/cgroup_helpers.c
> @@ -195,6 +195,11 @@ int setup_cgroup_environment(void)
>   
>   	format_cgroup_path(cgroup_workdir, "");
>   
> +	if (mkdir(CGROUP_MOUNT_PATH, 0777)) {
> +		log_err("mkdir mount");

It fails when the path does exist. This failed a lot of cgroup tests:

create_netns:PASS:create netns 0 nsec
(cgroup_helpers.c:199: errno: File exists) mkdir mount
#11 bind_perm: Failed to setup cgroup environment

> +		return 1;
> +	}
> +
>   	if (unshare(CLONE_NEWNS)) {
>   		log_err("unshare");
>   		return 1;