[LTP] [PATCH] cgroup_dir_mk: set the umask to '0' before creating the subdir

[Wei Gao]

On Fri, Mar 01, 2024 at 06:23:47PM +0800, Li Wang wrote:
> This is to resolve the permission issue when creating
> a new subdir in the cgroup, in case of system's default
> umask is 0077, this will trigger issues for LTP case.
> 
>  cgroup_core01.c will report following error msg:
>  cgroup_core01.c:50: TBROK: openat(21</sys/fs/cgroup/memory/ltp/test-3519/child_b>, 'tasks', 2, 0): EACCES (13)
> 
> Signed-off-by: Li Wang <liwang@redhat.com>
> Cc: Wei Gao <wegao@suse.com>
> ---
> 
> Notes:
>     Hi Wei, can you help confirm if this patch works for you?

@Li I have tested your patch and it can work.
@Li @Petr Thanks for your patch and comments, i suppose this patch can be merged.

> 
>  lib/tst_cgroup.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/lib/tst_cgroup.c b/lib/tst_cgroup.c
> index a8a598e0e..f6afb51d6 100644
> --- a/lib/tst_cgroup.c
> +++ b/lib/tst_cgroup.c
> @@ -361,6 +361,7 @@ static void cgroup_dir_mk(const struct cgroup_dir *const parent,
>  			  struct cgroup_dir *const new)
>  {
>  	const char *dpath;
> +	mode_t old_umask = umask(0);
>  
>  	new->dir_root = parent->dir_root;
>  	new->dir_name = dir_name;
> @@ -394,6 +395,7 @@ static void cgroup_dir_mk(const struct cgroup_dir *const parent,
>  opendir:
>  	new->dir_fd = SAFE_OPENAT(parent->dir_fd, dir_name,
>  				  O_PATH | O_DIRECTORY);
> +	umask(old_umask);
>  }
>  
>  #define PATH_MAX_STRLEN 4095
> -- 
> 2.40.1
>