[PATCH RFC v3 11/12] nvmet: make configfs setup namespace aware

[Hannes Reinecke <hare@kernel.org>]

Implement 'fill_subsystem' and 'clear_subsystem' callbacks to make
nvmet configfs namespace aware.

Signed-off-by: Hannes Reinecke <hare@kernel.org>
---
 drivers/nvme/target/configfs.c | 103 +++++++++++++++++++++++++++++++----------
 1 file changed, 78 insertions(+), 25 deletions(-)

diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index 9c761a7f98496d59aa993e3663f0b3da63b6d3c1..0c0f7719336d80e57a007e74ed542f6276f57fa0 100644
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -1780,6 +1780,7 @@ static void nvmet_subsys_release(struct config_item *item)
 {
 	struct nvmet_subsys *subsys = to_subsys(item);
 
+	configfs_remove_default_groups(&subsys->group);
 	nvmet_subsys_del_ctrls(subsys);
 	nvmet_subsys_put(subsys);
 }
@@ -2072,6 +2073,7 @@ static void nvmet_port_release(struct config_item *item)
 	flush_workqueue(nvmet_wq);
 	nvmet_del_port_list(port);
 
+	configfs_remove_default_groups(&port->group);
 	key_put(port->keyring);
 	kfree(port->ana_state);
 	kfree(port);
@@ -2185,9 +2187,6 @@ static const struct config_item_type nvmet_ports_type = {
 	.ct_owner		= THIS_MODULE,
 };
 
-static struct config_group nvmet_subsystems_group;
-static struct config_group nvmet_ports_group;
-
 #ifdef CONFIG_NVME_TARGET_AUTH
 static ssize_t nvmet_host_dhchap_key_show(struct config_item *item,
 		char *page)
@@ -2369,8 +2368,6 @@ static const struct config_item_type nvmet_hosts_type = {
 	.ct_owner		= THIS_MODULE,
 };
 
-static struct config_group nvmet_hosts_group;
-
 static ssize_t nvmet_root_discovery_nqn_show(struct config_item *item,
 					     char *page)
 {
@@ -2384,9 +2381,11 @@ static ssize_t nvmet_root_discovery_nqn_show(struct config_item *item,
 static ssize_t nvmet_root_discovery_nqn_store(struct config_item *item,
 		const char *page, size_t count)
 {
+	struct config_item *subsystems_item;
+	struct config_group *subsystems_group;
 	struct nvmet_subsys *disc_subsys;
 	struct list_head *entry;
-	char *old_nqn, *new_nqn;
+	char *old_nqn = NULL, *new_nqn;
 	size_t len;
 
 	len = strcspn(page, "\n");
@@ -2398,7 +2397,14 @@ static ssize_t nvmet_root_discovery_nqn_store(struct config_item *item,
 		return -ENOMEM;
 
 	down_write(&nvmet_config_sem);
-	list_for_each(entry, &nvmet_subsystems_group.cg_children) {
+	subsystems_item = config_group_find_item(to_config_group(item), "subsystems");
+	if (WARN_ON(!subsystems_item)) {
+		kfree(new_nqn);
+		up_write(&nvmet_config_sem);
+		return -EINVAL;
+	}
+	subsystems_group = to_config_group(subsystems_item);
+	list_for_each(entry, &subsystems_group->cg_children) {
 		struct config_item *item =
 			container_of(entry, struct config_item, ci_entry);
 
@@ -2432,6 +2438,69 @@ static const struct config_item_type nvmet_root_type = {
 	.ct_owner		= THIS_MODULE,
 };
 
+static int nvmet_configfs_fill_subsystem(struct configfs_subsystem *subsys,
+					 struct net *net_ns)
+{
+	struct config_group *subsystems_group, *ports_group, *hosts_group;
+	int err;
+
+	err = nvmet_add_disc_subsys(net_ns);
+	if (err < 0)
+		return err;
+
+	subsystems_group = kzalloc_obj(*subsystems_group);
+	if (!subsystems_group) {
+		nvmet_del_disc_subsys(net_ns);
+		return -ENOMEM;
+	}
+	config_group_init_type_name(subsystems_group,
+			"subsystems", &nvmet_subsystems_type);
+	configfs_add_default_group(subsystems_group,
+			&subsys->su_group);
+
+	ports_group = kzalloc_obj(*ports_group);
+	if (!ports_group) {
+		kfree(subsystems_group);
+		nvmet_del_disc_subsys(net_ns);
+		return -ENOMEM;
+	}
+	config_group_init_type_name(ports_group,
+			"ports", &nvmet_ports_type);
+	configfs_add_default_group(ports_group,
+			&subsys->su_group);
+
+	hosts_group = kzalloc_obj(*hosts_group);
+	if (!hosts_group) {
+		kfree(ports_group);
+		kfree(subsystems_group);
+		nvmet_del_disc_subsys(net_ns);
+		return -ENOMEM;
+	}
+	config_group_init_type_name(hosts_group,
+			"hosts", &nvmet_hosts_type);
+	configfs_add_default_group(hosts_group,
+			&subsys->su_group);
+	strscpy(subsys->su_group.cg_item.ci_namebuf, "nvmet",
+		sizeof(subsys->su_group.cg_item.ci_namebuf));
+	subsys->su_group.cg_item.ci_type = &nvmet_root_type;
+
+	return 0;
+}
+
+static void nvmet_configfs_clear_subsystem(struct configfs_subsystem *subsys,
+					   struct net *net_ns)
+{
+	struct config_group *g, *n;
+
+	list_for_each_entry_safe(g, n, &subsys->su_group.default_groups,
+				 group_entry) {
+		list_del(&g->group_entry);
+		config_item_put(&g->cg_item);
+		kfree(g);
+	}
+	nvmet_del_disc_subsys(net_ns);
+}
+
 static struct configfs_subsystem nvmet_configfs_subsystem = {
 	.su_group = {
 		.cg_item = {
@@ -2439,30 +2508,14 @@ static struct configfs_subsystem nvmet_configfs_subsystem = {
 			.ci_type	= &nvmet_root_type,
 		},
 	},
+	.fill_subsystem = nvmet_configfs_fill_subsystem,
+	.clear_subsystem = nvmet_configfs_clear_subsystem,
 };
 
 int __init nvmet_init_configfs(void)
 {
 	int ret;
 
-	config_group_init(&nvmet_configfs_subsystem.su_group);
-	mutex_init(&nvmet_configfs_subsystem.su_mutex);
-
-	config_group_init_type_name(&nvmet_subsystems_group,
-			"subsystems", &nvmet_subsystems_type);
-	configfs_add_default_group(&nvmet_subsystems_group,
-			&nvmet_configfs_subsystem.su_group);
-
-	config_group_init_type_name(&nvmet_ports_group,
-			"ports", &nvmet_ports_type);
-	configfs_add_default_group(&nvmet_ports_group,
-			&nvmet_configfs_subsystem.su_group);
-
-	config_group_init_type_name(&nvmet_hosts_group,
-			"hosts", &nvmet_hosts_type);
-	configfs_add_default_group(&nvmet_hosts_group,
-			&nvmet_configfs_subsystem.su_group);
-
 	ret = configfs_register_subsystem(&nvmet_configfs_subsystem);
 	if (ret) {
 		pr_err("configfs_register_subsystem: %d\n", ret);

-- 
2.51.0