Re: [PATCH v15 1/5] fs/nsfs.c: added ns_match

[Yonghong Song <yhs@fb.com>]

Hi, Eric,

Could you take a look at this patch the series as well?
If it looks good, could you ack the patch #1?

Thanks!

On 10/22/19 12:17 PM, Carlos Neira wrote:
> ns_match returns true if the namespace inode and dev_t matches the ones
> provided by the caller.
> 
> Signed-off-by: Carlos Neira <cneirabustos@gmail.com>
> ---
>   fs/nsfs.c               | 14 ++++++++++++++
>   include/linux/proc_ns.h |  2 ++
>   2 files changed, 16 insertions(+)
> 
> diff --git a/fs/nsfs.c b/fs/nsfs.c
> index a0431642c6b5..ef59cf347285 100644
> --- a/fs/nsfs.c
> +++ b/fs/nsfs.c
> @@ -245,6 +245,20 @@ struct file *proc_ns_fget(int fd)
>   	return ERR_PTR(-EINVAL);
>   }
>   
> +/**
> + * ns_match() - Returns true if current namespace matches dev/ino provided.
> + * @ns_common: current ns
> + * @dev: dev_t from nsfs that will be matched against current nsfs
> + * @ino: ino_t from nsfs that will be matched against current nsfs
> + *
> + * Return: true if dev and ino matches the current nsfs.
> + */
> +bool ns_match(const struct ns_common *ns, dev_t dev, ino_t ino)
> +{
> +	return (ns->inum == ino) && (nsfs_mnt->mnt_sb->s_dev == dev);
> +}
> +
> +
>   static int nsfs_show_path(struct seq_file *seq, struct dentry *dentry)
>   {
>   	struct inode *inode = d_inode(dentry);
> diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h
> index d31cb6215905..1da9f33489f3 100644
> --- a/include/linux/proc_ns.h
> +++ b/include/linux/proc_ns.h
> @@ -82,6 +82,8 @@ typedef struct ns_common *ns_get_path_helper_t(void *);
>   extern void *ns_get_path_cb(struct path *path, ns_get_path_helper_t ns_get_cb,
>   			    void *private_data);
>   
> +extern bool ns_match(const struct ns_common *ns, dev_t dev, ino_t ino);
> +
>   extern int ns_get_name(char *buf, size_t size, struct task_struct *task,
>   			const struct proc_ns_operations *ns_ops);
>   extern void nsfs_init(void);
>