Re: [PATCH 07/38] pidns 1/2: make create_pid_namespace() accept parent pidns

[Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>]

Alexey Dobriyan wrote:
> create_pid_namespace() creates everything, but caller has to assign parent
> pidns by hand, which is unnatural. At the moment of call new ->level has
> to be taken from somewhere and parent pidns is already available.
> 
> Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>

> ---
>  kernel/pid_namespace.c |    8 ++++----
>  1 files changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c
> index 2d1001b..495d5de 100644
> --- a/kernel/pid_namespace.c
> +++ b/kernel/pid_namespace.c
> @@ -67,9 +67,10 @@ err_alloc:
>  	return NULL;
>  }
>  
> -static struct pid_namespace *create_pid_namespace(unsigned int level)
> +static struct pid_namespace *create_pid_namespace(struct pid_namespace *parent_pid_ns)
>  {
>  	struct pid_namespace *ns;
> +	unsigned int level = parent_pid_ns->level + 1;
>  	int i;
>  
>  	ns = kmem_cache_zalloc(pid_ns_cachep, GFP_KERNEL);
> @@ -86,6 +87,7 @@ static struct pid_namespace *create_pid_namespace(unsigned int level)
>  
>  	kref_init(&ns->kref);
>  	ns->level = level;
> +	ns->parent = get_pid_ns(parent_pid_ns);
>  
>  	set_bit(0, ns->pidmap[0].page);
>  	atomic_set(&ns->pidmap[0].nr_free, BITS_PER_PAGE - 1);
> @@ -125,9 +127,7 @@ struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *old
>  	if (flags & CLONE_THREAD)
>  		goto out_put;
>  
> -	new_ns = create_pid_namespace(old_ns->level + 1);
> -	if (!IS_ERR(new_ns))
> -		new_ns->parent = get_pid_ns(old_ns);
> +	new_ns = create_pid_namespace(old_ns);
>  
>  out_put:
>  	put_pid_ns(old_ns);