[Devel] [PATCH VZ8 v1 02/14] cgroup/cfs: added 'activate' option to cgroup_add_file

[Kirill Tkhai]

On 20.01.2021 12:56, Valeriy Vdovin wrote:
> In kernfs files get created in 'deactivated' state, which means
> they are not visible.  Add option to activate the file after
> creation immediately making it visible in the parent directory.
> Will be used in later patches.
> 
> Signed-off-by: Valeriy Vdovin <valeriy.vdovin at virtuozzo.com>

Reviewed-by: Kirill Tkhai <ktkhai at virtuozzo.com>

> ---
>  kernel/cgroup/cgroup.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
> index 4488df184235..797a3971ab46 100644
> --- a/kernel/cgroup/cgroup.c
> +++ b/kernel/cgroup/cgroup.c
> @@ -3824,7 +3824,7 @@ static void cgroup_file_notify_timer(struct timer_list *timer)
>  }
>  
>  static int cgroup_add_file(struct cgroup_subsys_state *css, struct cgroup *cgrp,
> -			   struct cftype *cft)
> +			   struct cftype *cft, bool activate)
>  {
>  	char name[CGROUP_FILE_NAME_MAX];
>  	struct kernfs_node *kn;
> @@ -3866,6 +3866,8 @@ static int cgroup_add_file(struct cgroup_subsys_state *css, struct cgroup *cgrp,
>  		if (IS_ERR(kn_link))
>  			return PTR_ERR(kn_link);
>  	}
> +	if (activate)
> +		kernfs_activate(kn);
>  
>  	return 0;
>  }
> @@ -3903,7 +3905,7 @@ static int cgroup_addrm_files(struct cgroup_subsys_state *css,
>  		if ((cft->flags & CFTYPE_DEBUG) && !cgroup_debug)
>  			continue;
>  		if (is_add) {
> -			ret = cgroup_add_file(css, cgrp, cft);
> +			ret = cgroup_add_file(css, cgrp, cft, false);
>  			if (ret) {
>  				pr_warn("%s: failed to add %s, err=%d\n",
>  					__func__, cft->name, ret);
>