[PATCH RFC v2 11/12] nvmet: per net-namespace port list

[Hannes Reinecke]

The port list needs to be per net-namespace, as each network namespace
has a different view on the existing IP addresses etc.
So replace the global list with an xarray of lists indexed by the
network namespace id.

Signed-off-by: Hannes Reinecke <hare at kernel.org>
---
 drivers/nvme/target/configfs.c  | 61 ++++++++++++++++++++++++++++++++++++++---
 drivers/nvme/target/discovery.c |  4 ++-
 drivers/nvme/target/nvmet.h     |  1 -
 3 files changed, 60 insertions(+), 6 deletions(-)

diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index 6030647cee937195d772bcf4b92cb37b6ebf9f08..9c761a7f98496d59aa993e3663f0b3da63b6d3c1 100644
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -25,8 +25,7 @@
 static const struct config_item_type nvmet_host_type;
 static const struct config_item_type nvmet_subsys_type;
 
-static LIST_HEAD(nvmet_ports_list);
-struct list_head *nvmet_ports = &nvmet_ports_list;
+static DEFINE_XARRAY(nvmet_ports_xa);
 
 struct nvmet_type_name_map {
 	u8		type;
@@ -61,6 +60,60 @@ u64 nvmet_get_ns_id(struct net *net_ns)
 	return net_ns == &init_net ? 0 : ns->ns_id;
 }
 
+struct list_head *nvmet_get_port_list(struct net *net_ns)
+{
+	struct list_head *port_list;
+	u64 ns_id = nvmet_get_ns_id(net_ns);
+
+	port_list = xa_load(&nvmet_ports_xa, ns_id);
+	return port_list;
+}
+
+static int nvmet_add_port_list(struct nvmet_port *p)
+{
+	u64 ns_id = nvmet_get_ns_id(&init_net);
+	struct list_head *port_list;
+	int err = 0;
+
+	xa_lock(&nvmet_ports_xa);
+	port_list = xa_load(&nvmet_ports_xa, ns_id);
+	if (!port_list) {
+		port_list = kzalloc_obj(*port_list);
+		if (!port_list) {
+			err = -ENOMEM;
+			goto out_unlock;
+		}
+		INIT_LIST_HEAD(port_list);
+		err = __xa_insert(&nvmet_ports_xa, ns_id,
+				  port_list, GFP_KERNEL);
+		if (err < 0) {
+			kfree(port_list);
+			goto out_unlock;
+		}
+	}
+	list_add(&p->global_entry, port_list);
+out_unlock:
+	xa_unlock(&nvmet_ports_xa);
+	return err;
+}
+
+static void nvmet_del_port_list(struct nvmet_port *p)
+{
+	struct list_head *port_list;
+	u64 ns_id = nvmet_get_ns_id(&init_net);
+
+	xa_lock(&nvmet_ports_xa);
+	port_list = xa_load(&nvmet_ports_xa, ns_id);
+	if (!WARN_ON(!port_list)) {
+		list_del_init(&p->global_entry);
+		if (list_empty(port_list)) {
+			__xa_erase(&nvmet_ports_xa, ns_id);
+			kfree(port_list);
+		}
+	}
+	xa_unlock(&nvmet_ports_xa);
+}
+
 static bool nvmet_is_port_enabled(struct nvmet_port *p, const char *caller)
 {
 	if (p->enabled)
@@ -2017,7 +2070,7 @@ static void nvmet_port_release(struct config_item *item)
 
 	/* Let inflight controllers teardown complete */
 	flush_workqueue(nvmet_wq);
-	list_del(&port->global_entry);
+	nvmet_del_port_list(port);
 
 	key_put(port->keyring);
 	kfree(port->ana_state);
@@ -2085,7 +2138,7 @@ static struct config_group *nvmet_ports_make(struct config_group *group,
 			port->ana_state[i] = NVME_ANA_INACCESSIBLE;
 	}
 
-	list_add(&port->global_entry, &nvmet_ports_list);
+	nvmet_add_port_list(port);
 
 	INIT_LIST_HEAD(&port->entry);
 	INIT_LIST_HEAD(&port->subsystems);
diff --git a/drivers/nvme/target/discovery.c b/drivers/nvme/target/discovery.c
index 4a0e5929125ece4c98bf25918ce82b66d4140228..e929402314f66b635e330980d4d771b9474e7e3d 100644
--- a/drivers/nvme/target/discovery.c
+++ b/drivers/nvme/target/discovery.c
@@ -111,6 +111,7 @@ void nvmet_subsys_disc_changed(struct nvmet_subsys *subsys,
 {
 	struct nvmet_port *port;
 	struct nvmet_subsys_link *s;
+	struct list_head *port_list;
 	struct nvmet_subsys *disc_subsys;
 
 	lockdep_assert_held(&nvmet_config_sem);
@@ -119,7 +120,8 @@ void nvmet_subsys_disc_changed(struct nvmet_subsys *subsys,
 		return;
 	disc_subsys->genctr++;
 
-	list_for_each_entry(port, nvmet_ports, global_entry)
+	port_list = nvmet_get_port_list(&init_net);
+	list_for_each_entry(port, port_list, global_entry)
 		list_for_each_entry(s, &port->subsystems, entry) {
 			if (s->subsys != subsys)
 				continue;
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index 2bbee443ce7c7a13be15976c18ab003265a366cb..fc871b2b777d633dd64b6d339e124668fd760f8b 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -665,7 +665,6 @@ u16 nvmet_zero_sgl(struct nvmet_req *req, off_t off, size_t len);
 u32 nvmet_get_log_page_len(struct nvme_command *cmd);
 u64 nvmet_get_log_page_offset(struct nvme_command *cmd);
 
-extern struct list_head *nvmet_ports;
 void nvmet_port_disc_changed(struct nvmet_port *port,
 		struct nvmet_subsys *subsys);
 void nvmet_subsys_disc_changed(struct nvmet_subsys *subsys,

-- 
2.51.0