[PATCH v2 1/3] nvmet: Expose max queues to sysfs

[Sagi Grimberg]

> Allow to set the max queues the target supports. This is useful for
> testing the reconnect attempt of the host with chaning numbers of
> supported queues.
> 
> Signed-off-by: Daniel Wagner <dwagner at suse.de>
> ---
>   drivers/nvme/target/configfs.c | 25 +++++++++++++++++++++++++
>   1 file changed, 25 insertions(+)
> 
> diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
> index 2bcd60758919..ba9f3209f848 100644
> --- a/drivers/nvme/target/configfs.c
> +++ b/drivers/nvme/target/configfs.c
> @@ -1281,6 +1281,30 @@ static ssize_t nvmet_subsys_attr_pi_enable_store(struct config_item *item,
>   CONFIGFS_ATTR(nvmet_subsys_, attr_pi_enable);
>   #endif
>   
> +static ssize_t nvmet_subsys_attr_qid_max_show(struct config_item *item,
> +					      char *page)
> +{
> +	return snprintf(page, PAGE_SIZE, "%u\n", to_subsys(item)->max_qid);
> +}
> +
> +static ssize_t nvmet_subsys_attr_qid_max_store(struct config_item *item,
> +					       const char *page, size_t cnt)
> +{
> +	u16 qid_max;
> +
> +	if (sscanf(page, "%hu\n", &qid_max) != 1)
> +		return -EINVAL;
> +
> +	if (qid_max == 0)
> +		return -EINVAL;

This needs an upper limit.