nvmet: enable Discovery Controller AENs

Add functions to find connections requesting Discovery Change events
and send a notification to hosts that maintain an explicit persistent
connection and have and active Asynchronous Event Request pending.
Only Hosts that have access to the Subsystem effected by the change
will receive notifications of Discovery Change event.

Call these functions each time there is a configfs change that effects
the Discover Log Pages.

Set the OAES field in the Identify Controller response to advertise the
support for Asynchronous Event Notifications.

Signed-off-by: Jay Sternberg <jay.e.sternberg@intel.com>
Reviewed-by: Phil Cayton <phil.cayton@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 23 insertions, 7 deletions

diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index d895579b6c5d..d37fd7713bbc 100644
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -25,6 +25,9 @@
 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 const struct nvmet_transport_name {
 	u8		type;
 	const char	*name;
@@ -646,7 +649,8 @@ static int nvmet_port_subsys_allow_link(struct config_item *parent,
 	}
 
 	list_add_tail(&link->entry, &port->subsystems);
-	nvmet_genctr++;
+	nvmet_port_disc_changed(port, subsys);
+
 	up_write(&nvmet_config_sem);
 	return 0;
 
@@ -673,7 +677,8 @@ static void nvmet_port_subsys_drop_link(struct config_item *parent,
 
 found:
 	list_del(&p->entry);
-	nvmet_genctr++;
+	nvmet_port_disc_changed(port, subsys);
+
 	if (list_empty(&port->subsystems))
 		nvmet_disable_port(port);
 	up_write(&nvmet_config_sem);
@@ -722,7 +727,8 @@ static int nvmet_allowed_hosts_allow_link(struct config_item *parent,
 			goto out_free_link;
 	}
 	list_add_tail(&link->entry, &subsys->hosts);
-	nvmet_genctr++;
+	nvmet_subsys_disc_changed(subsys, host);
+
 	up_write(&nvmet_config_sem);
 	return 0;
 out_free_link:
@@ -748,7 +754,8 @@ static void nvmet_allowed_hosts_drop_link(struct config_item *parent,
 
 found:
 	list_del(&p->entry);
-	nvmet_genctr++;
+	nvmet_subsys_disc_changed(subsys, host);
+
 	up_write(&nvmet_config_sem);
 	kfree(p);
 }
@@ -787,7 +794,11 @@ static ssize_t nvmet_subsys_attr_allow_any_host_store(struct config_item *item,
 		goto out_unlock;
 	}
 
-	subsys->allow_any_host = allow_any_host;
+	if (subsys->allow_any_host != allow_any_host) {
+		subsys->allow_any_host = allow_any_host;
+		nvmet_subsys_disc_changed(subsys, NULL);
+	}
+
 out_unlock:
 	up_write(&nvmet_config_sem);
 	return ret ? ret : count;
@@ -936,7 +947,7 @@ static ssize_t nvmet_referral_enable_store(struct config_item *item,
 	if (enable)
 		nvmet_referral_enable(parent, port);
 	else
-		nvmet_referral_disable(port);
+		nvmet_referral_disable(parent, port);
 
 	return count;
 inval:
@@ -962,9 +973,10 @@ static struct configfs_attribute *nvmet_referral_attrs[] = {
 
 static void nvmet_referral_release(struct config_item *item)
 {
+	struct nvmet_port *parent = to_nvmet_port(item->ci_parent->ci_parent);
 	struct nvmet_port *port = to_nvmet_port(item);
 
-	nvmet_referral_disable(port);
+	nvmet_referral_disable(parent, port);
 	kfree(port);
 }
 
@@ -1137,6 +1149,8 @@ static void nvmet_port_release(struct config_item *item)
 {
 	struct nvmet_port *port = to_nvmet_port(item);
 
+	list_del(&port->global_entry);
+
 	kfree(port->ana_state);
 	kfree(port);
 }
@@ -1189,6 +1203,8 @@ 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);
+
 	INIT_LIST_HEAD(&port->entry);
 	INIT_LIST_HEAD(&port->subsystems);
 	INIT_LIST_HEAD(&port->referrals);