[PATCH 1/3 rfc] nvme-fabrics: allow discovery subsystems accept a kato

[hare@suse.de (Hannes Reinecke)]

On 2/23/19 3:31 AM, Sagi Grimberg wrote:
> This modifies the behavior of discovery subsystems to accept
> a kato as a preparation to support discovery log change
> events. This also means that now every discovery controller
> will have a default kato value, and for non-persistent connections
> the host needs to pass in a zero kato value (keep_alive_tmo=0).
> 
> Signed-off-by: Sagi Grimberg <sagi at grimberg.me>
> ---
>   drivers/nvme/host/fabrics.c | 12 ++----------
>   1 file changed, 2 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/nvme/host/fabrics.c b/drivers/nvme/host/fabrics.c
> index 70c09abcfcbf..9d53ea4939cd 100644
> --- a/drivers/nvme/host/fabrics.c
> +++ b/drivers/nvme/host/fabrics.c
> @@ -389,8 +389,8 @@ int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl)
>   	 * Set keep-alive timeout in seconds granularity (ms * 1000)
>   	 * and add a grace period for controller kato enforcement
>   	 */
> -	cmd.connect.kato = ctrl->opts->discovery_nqn ? 0 :
> -		cpu_to_le32((ctrl->kato + NVME_KATO_GRACE) * 1000);
> +	cmd.connect.kato = ctrl->kato ?
> +		cpu_to_le32((ctrl->kato + NVME_KATO_GRACE) * 1000) : 0;
>   
>   	if (ctrl->opts->disable_sqflow)
>   		cmd.connect.cattr |= NVME_CONNECT_DISABLE_SQFLOW;
> @@ -746,13 +746,6 @@ static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
>   				pr_warn("keep_alive_tmo 0 won't execute keep alives!!!\n");
>   			}
>   			opts->kato = token;
> -
> -			if (opts->discovery_nqn && opts->kato) {
> -				pr_err("Discovery controllers cannot accept KATO != 0\n");
> -				ret = -EINVAL;
> -				goto out;
> -			}
> -
>   			break;
>   		case NVMF_OPT_CTRL_LOSS_TMO:
>   			if (match_int(args, &token)) {
> @@ -873,7 +866,6 @@ static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
>   	}
>   
>   	if (opts->discovery_nqn) {
> -		opts->kato = 0;
>   		opts->nr_io_queues = 0;
>   		opts->nr_write_queues = 0;
>   		opts->nr_poll_queues = 0;
> 

Reviewed-by: Hannes Reinecke <hare at suse.com>

Cheers,

Hannes