[PATCH 1/3] nvmet: expose discovery subsystem in sysfs

[Hannes Reinecke <hare@suse.de>]

Expose the discovery subsystem in sysfs instead of having it as
an internal structure. This requires the admin to manually
enable the discovery subsystem by linking it to a port, but
this can be seen as a feature as it will allows us to expose
subsystems without discovery subsystems and discovery subsystems
with no I/O subsystems.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/nvme/target/configfs.c  | 11 +++++++++++
 drivers/nvme/target/core.c      |  1 +
 drivers/nvme/target/discovery.c |  7 +------
 3 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index a54cbddd764e..9b94af2444b2 100644
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -1041,6 +1041,11 @@ static ssize_t nvmet_subsys_attr_allow_any_host_store(struct config_item *item,
 	if (strtobool(page, &allow_any_host))
 		return -EINVAL;
 
+	if (subsys == nvmet_disc_subsys) {
+		pr_err("Can't change allow_any_host on discovery subsystem!\n");
+		return -EPERM;
+	}
+
 	down_write(&nvmet_config_sem);
 	if (allow_any_host && !list_empty(&subsys->hosts)) {
 		pr_err("Can't set allow_any_host when explicit hosts are set!\n");
@@ -1965,6 +1970,12 @@ int __init nvmet_init_configfs(void)
 	configfs_add_default_group(&nvmet_subsystems_group,
 			&nvmet_configfs_subsystem.su_group);
 
+	config_group_init_type_name(&nvmet_disc_subsys->group,
+				    NVME_DISC_SUBSYS_NAME,
+				    &nvmet_subsys_type);
+	configfs_add_default_group(&nvmet_disc_subsys->group,
+				   &nvmet_subsystems_group);
+
 	config_group_init_type_name(&nvmet_ports_group,
 			"ports", &nvmet_ports_type);
 	configfs_add_default_group(&nvmet_ports_group,
diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 44f544356081..fab92c008c53 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -1557,6 +1557,7 @@ struct nvmet_subsys *nvmet_subsys_alloc(const char *subsysnqn,
 		break;
 	case NVME_NQN_DISC:
 	case NVME_NQN_CURR:
+		subsys->allow_any_host = 1;
 		subsys->max_qid = 0;
 		break;
 	default:
diff --git a/drivers/nvme/target/discovery.c b/drivers/nvme/target/discovery.c
index c2162eef8ce1..90bcc829c12a 100644
--- a/drivers/nvme/target/discovery.c
+++ b/drivers/nvme/target/discovery.c
@@ -208,18 +208,13 @@ static void nvmet_execute_disc_get_log_page(struct nvmet_req *req)
 
 	nvmet_set_disc_traddr(req, req->port, traddr);
 
-	nvmet_format_discovery_entry(hdr, req->port,
-				     nvmet_disc_subsys->subsysnqn,
-				     traddr, NVME_NQN_CURR, numrec);
-	numrec++;
-
 	list_for_each_entry(p, &req->port->subsystems, entry) {
 		if (!nvmet_host_allowed(p->subsys, ctrl->hostnqn))
 			continue;
 
 		nvmet_format_discovery_entry(hdr, req->port,
 				p->subsys->subsysnqn, traddr,
-				NVME_NQN_NVME, numrec);
+				p->subsys->type, numrec);
 		numrec++;
 	}
 
-- 
2.29.2