Re: [PATCH 2/9] mnt: expose pointer to init_mnt_ns

[Jan Kara]

On Wed 17-09-25 12:28:01, Christian Brauner wrote:
> There's various scenarios where we need to know whether we are in the
> initial set of namespaces or not to e.g., shortcut permission checking.
> All namespaces expose that information. Let's do that too.
> 
> Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>

Right. Feel free to add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

								Honza

> ---
>  fs/namespace.c                | 2 ++
>  include/linux/mnt_namespace.h | 2 ++
>  2 files changed, 4 insertions(+)
> 
> diff --git a/fs/namespace.c b/fs/namespace.c
> index a68998449698..c8251545d57e 100644
> --- a/fs/namespace.c
> +++ b/fs/namespace.c
> @@ -81,6 +81,7 @@ static DECLARE_RWSEM(namespace_sem);
>  static HLIST_HEAD(unmounted);	/* protected by namespace_sem */
>  static LIST_HEAD(ex_mountpoints); /* protected by namespace_sem */
>  static struct mnt_namespace *emptied_ns; /* protected by namespace_sem */
> +struct mnt_namespace *init_mnt_ns;
>  
>  #ifdef CONFIG_FSNOTIFY
>  LIST_HEAD(notify_list); /* protected by namespace_sem */
> @@ -6037,6 +6038,7 @@ static void __init init_mount_tree(void)
>  	set_fs_root(current->fs, &root);
>  
>  	ns_tree_add(ns);
> +	init_mnt_ns = ns;
>  }
>  
>  void __init mnt_init(void)
> diff --git a/include/linux/mnt_namespace.h b/include/linux/mnt_namespace.h
> index 70b366b64816..7e23c8364a9c 100644
> --- a/include/linux/mnt_namespace.h
> +++ b/include/linux/mnt_namespace.h
> @@ -11,6 +11,8 @@ struct fs_struct;
>  struct user_namespace;
>  struct ns_common;
>  
> +extern struct mnt_namespace *init_mnt_ns;
> +
>  extern struct mnt_namespace *copy_mnt_ns(unsigned long, struct mnt_namespace *,
>  		struct user_namespace *, struct fs_struct *);
>  extern void put_mnt_ns(struct mnt_namespace *ns);
> 
> -- 
> 2.47.3
> 
-- 
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR