Re: [PATCH v2 2/5] lockd: add a /proc/fs/lockd/nlm_end_grace file

["J. Bruce Fields" <bfields@fieldses.org>]

On Tue, Aug 19, 2014 at 02:38:26PM -0400, Jeff Layton wrote:
> Add a new procfile that will allow a (privileged) userland process to
> end the NLM grace period early. The basic idea here will be to have
> sm-notify write to this file, if it sent out no NOTIFY requests when
> it runs. In that situation, we can generally expect that there will be
> no reclaim requests so the grace period can be lifted early.
> 
> +static ssize_t
> +nlm_end_grace_write(struct file *file, const char __user *buf, size_t size,
> +		    loff_t *pos)
> +{
> +	struct lockd_net *ln = net_generic(current->nsproxy->net_ns, lockd_net_id);
> +
> +	if (size > 0)

I'd rather we expect some particular string ("Y\n"?) and return -EINVAL
otherwise, just in case we want to extend this some day.

--b.