[PATCH 2/6] nvme: export nvme_find_get_subsystem()/nvme_put_subsystem()

[hare@kernel.org]

From: Hannes Reinecke <hare@kernel.org>

Export functions to find and release a subsystem based on the
subsystem NQN.

Signed-off-by: Hannes Reinecke <hare@kernel.org>
---
 drivers/nvme/host/core.c | 14 ++++++++++++--
 drivers/nvme/host/nvme.h |  2 ++
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 895fb163d48e..a2f3da453af4 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -147,7 +147,6 @@ static const struct class nvme_ns_chr_class = {
 	.name = "nvme-generic",
 };
 
-static void nvme_put_subsystem(struct nvme_subsystem *subsys);
 static void nvme_remove_invalid_namespaces(struct nvme_ctrl *ctrl,
 					   unsigned nsid);
 static void nvme_update_keep_alive(struct nvme_ctrl *ctrl,
@@ -3115,7 +3114,7 @@ static void nvme_destroy_subsystem(struct kref *ref)
 	put_device(&subsys->dev);
 }
 
-static void nvme_put_subsystem(struct nvme_subsystem *subsys)
+void nvme_put_subsystem(struct nvme_subsystem *subsys)
 {
 	kref_put(&subsys->ref, nvme_destroy_subsystem);
 }
@@ -3148,6 +3147,17 @@ static struct nvme_subsystem *__nvme_find_get_subsystem(const char *subsysnqn)
 	return NULL;
 }
 
+struct nvme_subsystem *nvme_find_get_subsystem(const char *subsysnqn)
+{
+	struct nvme_subsystem *subsys;
+
+	mutex_lock(&nvme_subsystems_lock);
+	subsys = __nvme_find_get_subsystem(subsysnqn);
+	mutex_unlock(&nvme_subsystems_lock);
+	return subsys;
+}
+EXPORT_SYMBOL_GPL(nvme_find_get_subsystem);
+
 static inline bool nvme_discovery_ctrl(struct nvme_ctrl *ctrl)
 {
 	return ctrl->opts && ctrl->opts->discovery_nqn;
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 7df2ea21851f..f1eb8ae57c84 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -948,6 +948,8 @@ extern const struct attribute_group *nvme_subsys_attrs_groups[];
 extern const struct attribute_group *nvme_dev_attr_groups[];
 extern const struct block_device_operations nvme_bdev_ops;
 
+struct nvme_subsystem *nvme_find_get_subsystem(const char *subsysnqn);
+void nvme_put_subsystem(struct nvme_subsystem *subsys);
 void nvme_delete_ctrl_sync(struct nvme_ctrl *ctrl);
 struct nvme_ns *nvme_find_path(struct nvme_ns_head *head);
 #ifdef CONFIG_NVME_MULTIPATH
-- 
2.43.0