[PATCH 1/2] nvmet: make 'readonly' setting configurable

[Keith Busch]

On Thu, Apr 03, 2025 at 04:47:46PM +0200, Hannes Reinecke wrote:
> +static ssize_t nvmet_ns_readonly_store(struct config_item *item,
> +		const char *page, size_t count)
> +{
> +	struct nvmet_ns *ns = to_nvmet_ns(item);
> +	bool val;
> +
> +	if (kstrtobool(page, &val))
> +		return -EINVAL;
> +
> +	mutex_lock(&ns->subsys->lock);
> +	if (ns->enabled) {
> +		pr_err("the ns:%d is already enabled.\n", ns->nsid);
> +		mutex_unlock(&ns->subsys->lock);
> +		return -EINVAL;
> +	}
> +	ns->readonly = val;
> +	mutex_unlock(&ns->subsys->lock);

Not sure how people feel about the "cleanup" constructs. If we're okay
using them in this driver, this is a simple use case for the guard to
manage the mutex:

	guard(mutex)(&ns->subsys->lock);

And then you don't need to worry about unlocking.

> +	return count;
> +}