Re: [PATCH RFC 04/11] nvmet: Add function to get nvmet_fabrics_ops from trtype

Damien Le Moal
2025-03-13T09:03:16Z

On 3/13/25 14:18, Mike Christie wrote:
> In the next patches we allow users to create static controllers if the
> driver supports it. To get this info we need the nvmet_fabrics_ops
> a little sooner then port enablement so this creates a function to go
> from trtype to nvmet_fabrics_ops.
>
> Signed-off-by: Mike Christie <michael.christie@oracle.com>
> ---
> drivers/nvme/target/core.c | 41 +++++++++++++++++++++++--------------
> drivers/nvme/target/nvmet.h | 1 +
> 2 files changed, 27 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
> index 4de534eafd89..06967c00e9a2 100644
> --- a/drivers/nvme/target/core.c
> +++ b/drivers/nvme/target/core.c
> @@ -306,6 +306,30 @@ void nvmet_unregister_transport(const struct nvmet_fabrics_ops *ops)
> }
> EXPORT_SYMBOL_GPL(nvmet_unregister_transport);
>
> +const struct nvmet_fabrics_ops *nvmet_get_ops_by_transport(int trtype)
> +{
> + const struct nvmet_fabrics_ops *ops;
> +
> + lockdep_assert_held(&nvmet_config_sem);
> +
> + ops = nvmet_transports[trtype];
> + if (!ops) {
> + up_write(&nvmet_config_sem);
> + request_module("nvmet-transport-%d", trtype);
> + down_write(&nvmet_config_sem);
> + ops = nvmet_transports[trtype];
> + if (!ops) {
> + pr_err("transport type %d not supported\n", trtype);
> + return NULL;
> + }
> + }
> +
> + if (!try_module_get(ops->owner))
> + return NULL;
> +
> + return ops;
> +}
> +
> void nvmet_port_del_ctrls(struct nvmet_port *port, struct nvmet_subsys *subsys)
> {
> struct nvmet_ctrl *ctrl;
> @@ -325,22 +349,9 @@ int nvmet_enable_port(struct nvmet_port *port)
>
> lockdep_assert_held(&nvmet_config_sem);
>
> - ops = nvmet_transports[port->disc_addr.trtype];
> - if (!ops) {
> - up_write(&nvmet_config_sem);
> - request_module("nvmet-transport-%d", port->disc_addr.trtype);
> - down_write(&nvmet_config_sem);
> - ops = nvmet_transports[port->disc_addr.trtype];
> - if (!ops) {
> - pr_err("transport type %d not supported\n",
> - port->disc_addr.trtype);
> - return -EINVAL;
> - }
> - }
> -
> - if (!try_module_get(ops->owner))
> + ops = nvmet_get_ops_by_transport(port->disc_addr.trtype);
> + if (!ops)
> return -EINVAL;
> -

whiteline change.

> /*
> * If the user requested PI support and the transport isn't pi capable,
> * don't enable the port.
> diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
> index ec3d10eb316a..052ea4a105fc 100644
> --- a/drivers/nvme/target/nvmet.h
> +++ b/drivers/nvme/target/nvmet.h
> @@ -622,6 +622,7 @@ void nvmet_port_send_ana_event(struct nvmet_port *port);
>
> int nvmet_register_transport(const struct nvmet_fabrics_ops *ops);
> void nvmet_unregister_transport(const struct nvmet_fabrics_ops *ops);
> +const struct nvmet_fabrics_ops *nvmet_get_ops_by_transport(int trtype);
>
> void nvmet_port_del_ctrls(struct nvmet_port *port,
> struct nvmet_subsys *subsys);

--
Damien Le Moal
Western Digital Research