[PATCH 3/3] nvmet: don't report subsys with 0 namespaces

[Chaitanya Kulkarni]

Skip reporting the subsys from the discovery log page which has no
namespaces.

This is needed because we don't allow creating a controller from such
subsystem from previous patch.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni at wdc.com>
---
 drivers/nvme/target/discovery.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/nvme/target/discovery.c b/drivers/nvme/target/discovery.c
index 7aa62bc6ae84..03a34ad3d59b 100644
--- a/drivers/nvme/target/discovery.c
+++ b/drivers/nvme/target/discovery.c
@@ -158,6 +158,17 @@ static size_t discovery_log_entries(struct nvmet_req *req)
 	return entries;
 }
 
+static bool nvmet_disc_get_log_report_subsys(struct nvmet_subsys *s)
+{
+	bool skip;
+
+	mutex_lock(&s->lock);
+	/* skip reporting the subsys with 0 MNAN */
+	skip = s->max_nsid ? true : false;
+	mutex_unlock(&s->lock);
+	return skip;
+}
+
 static void nvmet_execute_disc_get_log_page(struct nvmet_req *req)
 {
 	const int entry_size = sizeof(struct nvmf_disc_rsp_page_entry);
@@ -210,6 +221,8 @@ static void nvmet_execute_disc_get_log_page(struct nvmet_req *req)
 
 		if (!nvmet_host_allowed(p->subsys, ctrl->hostnqn))
 			continue;
+		if (!nvmet_disc_get_log_report_subsys(p->subsys))
+			continue;
 
 		nvmet_set_disc_traddr(req, req->port, traddr);
 		nvmet_format_discovery_entry(hdr, req->port,
-- 
2.22.1