4 files changed, 111 insertions, 1 deletions

diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index cdec47de89ed..61c258dea88a 100644
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -879,6 +879,10 @@ static ssize_t nvmet_subsys_attr_version_store(struct config_item *item,
 	int major, minor, tertiary = 0;
 	int ret;
 
+	/* passthru subsystems use the underlying controller's version */
+	if (nvmet_passthru_ctrl(subsys))
+		return -EINVAL;
+
 	ret = sscanf(page, "%d.%d.%d\n", &major, &minor, &tertiary);
 	if (ret != 2 && ret != 3)
 		return -EINVAL;
diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index c5a1c82e699b..b92f45f5cd5b 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -544,6 +544,12 @@ int nvmet_ns_enable(struct nvmet_ns *ns)
 
 	mutex_lock(&subsys->lock);
 	ret = 0;
+
+	if (nvmet_passthru_ctrl(subsys)) {
+		pr_info("cannot enable both passthru and regular namespaces for a single subsystem");
+		goto out_unlock;
+	}
+
 	if (ns->enabled)
 		goto out_unlock;
 
@@ -1473,7 +1479,7 @@ struct nvmet_subsys *nvmet_subsys_alloc(const char *subsysnqn,
 	if (!subsys)
 		return ERR_PTR(-ENOMEM);
 
-	subsys->ver = NVME_VS(1, 3, 0); /* NVMe 1.3.0 */
+	subsys->ver = NVMET_DEFAULT_VS;
 	/* generate a random serial number as our controllers are ephemeral: */
 	get_random_bytes(&subsys->serial, sizeof(subsys->serial));
 
@@ -1516,6 +1522,8 @@ static void nvmet_subsys_free(struct kref *ref)
 	WARN_ON_ONCE(!xa_empty(&subsys->namespaces));
 
 	xa_destroy(&subsys->namespaces);
+	nvmet_passthru_subsys_free(subsys);
+
 	kfree(subsys->subsysnqn);
 	kfree_rcu(subsys->model, rcuhead);
 	kfree(subsys);
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index 51719dc62083..9d0aa6560c0c 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -21,6 +21,8 @@
 #include <linux/radix-tree.h>
 #include <linux/t10-pi.h>
 
+#define NVMET_DEFAULT_VS		NVME_VS(1, 3, 0)
+
 #define NVMET_ASYNC_EVENTS		4
 #define NVMET_ERROR_LOG_SLOTS		128
 #define NVMET_NO_ERROR_LOC		((u16)-1)
@@ -245,6 +247,7 @@ struct nvmet_subsys {
 
 #ifdef CONFIG_NVME_TARGET_PASSTHRU
 	struct nvme_ctrl	*passthru_ctrl;
+	char			*passthru_ctrl_path;
 #endif /* CONFIG_NVME_TARGET_PASSTHRU */
 };
 
@@ -544,6 +547,9 @@ static inline u32 nvmet_dsm_len(struct nvmet_req *req)
 }
 
 #ifdef CONFIG_NVME_TARGET_PASSTHRU
+void nvmet_passthru_subsys_free(struct nvmet_subsys *subsys);
+int nvmet_passthru_ctrl_enable(struct nvmet_subsys *subsys);
+void nvmet_passthru_ctrl_disable(struct nvmet_subsys *subsys);
 u16 nvmet_parse_passthru_admin_cmd(struct nvmet_req *req);
 u16 nvmet_parse_passthru_io_cmd(struct nvmet_req *req);
 static inline struct nvme_ctrl *nvmet_passthru_ctrl(struct nvmet_subsys *subsys)
@@ -551,6 +557,12 @@ static inline struct nvme_ctrl *nvmet_passthru_ctrl(struct nvmet_subsys *subsys)
 	return subsys->passthru_ctrl;
 }
 #else /* CONFIG_NVME_TARGET_PASSTHRU */
+static inline void nvmet_passthru_subsys_free(struct nvmet_subsys *subsys)
+{
+}
+static inline void nvmet_passthru_ctrl_disable(struct nvmet_subsys *subsys)
+{
+}
 static inline u16 nvmet_parse_passthru_admin_cmd(struct nvmet_req *req)
 {
 	return 0;
diff --git a/drivers/nvme/target/passthru.c b/drivers/nvme/target/passthru.c
index b9727553ab30..89d91dc999a6 100644
--- a/drivers/nvme/target/passthru.c
+++ b/drivers/nvme/target/passthru.c
@@ -15,6 +15,11 @@
 
 MODULE_IMPORT_NS(NVME_TARGET_PASSTHRU);
 
+/*
+ * xarray to maintain one passthru subsystem per nvme controller.
+ */
+static DEFINE_XARRAY(passthru_subsystems);
+
 static u16 nvmet_passthru_override_id_ctrl(struct nvmet_req *req)
 {
 	struct nvmet_ctrl *ctrl = req->sq->ctrl;
@@ -456,3 +461,84 @@ u16 nvmet_parse_passthru_admin_cmd(struct nvmet_req *req)
 		return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 	}
 }
+
+int nvmet_passthru_ctrl_enable(struct nvmet_subsys *subsys)
+{
+	struct nvme_ctrl *ctrl;
+	int ret = -EINVAL;
+	void *old;
+
+	mutex_lock(&subsys->lock);
+	if (!subsys->passthru_ctrl_path)
+		goto out_unlock;
+	if (subsys->passthru_ctrl)
+		goto out_unlock;
+
+	if (subsys->nr_namespaces) {
+		pr_info("cannot enable both passthru and regular namespaces for a single subsystem");
+		goto out_unlock;
+	}
+
+	ctrl = nvme_ctrl_get_by_path(subsys->passthru_ctrl_path);
+	if (IS_ERR(ctrl)) {
+		ret = PTR_ERR(ctrl);
+		pr_err("failed to open nvme controller %s\n",
+		       subsys->passthru_ctrl_path);
+
+		goto out_unlock;
+	}
+
+	old = xa_cmpxchg(&passthru_subsystems, ctrl->cntlid, NULL,
+			 subsys, GFP_KERNEL);
+	if (xa_is_err(old)) {
+		ret = xa_err(old);
+		goto out_put_ctrl;
+	}
+
+	if (old)
+		goto out_put_ctrl;
+
+	subsys->passthru_ctrl = ctrl;
+	subsys->ver = ctrl->vs;
+
+	if (subsys->ver < NVME_VS(1, 2, 1)) {
+		pr_warn("nvme controller version is too old: %llu.%llu.%llu, advertising 1.2.1\n",
+			NVME_MAJOR(subsys->ver), NVME_MINOR(subsys->ver),
+			NVME_TERTIARY(subsys->ver));
+		subsys->ver = NVME_VS(1, 2, 1);
+	}
+
+	mutex_unlock(&subsys->lock);
+	return 0;
+
+out_put_ctrl:
+	nvme_put_ctrl(ctrl);
+out_unlock:
+	mutex_unlock(&subsys->lock);
+	return ret;
+}
+
+static void __nvmet_passthru_ctrl_disable(struct nvmet_subsys *subsys)
+{
+	if (subsys->passthru_ctrl) {
+		xa_erase(&passthru_subsystems, subsys->passthru_ctrl->cntlid);
+		nvme_put_ctrl(subsys->passthru_ctrl);
+	}
+	subsys->passthru_ctrl = NULL;
+	subsys->ver = NVMET_DEFAULT_VS;
+}
+
+void nvmet_passthru_ctrl_disable(struct nvmet_subsys *subsys)
+{
+	mutex_lock(&subsys->lock);
+	__nvmet_passthru_ctrl_disable(subsys);
+	mutex_unlock(&subsys->lock);
+}
+
+void nvmet_passthru_subsys_free(struct nvmet_subsys *subsys)
+{
+	mutex_lock(&subsys->lock);
+	__nvmet_passthru_ctrl_disable(subsys);
+	mutex_unlock(&subsys->lock);
+	kfree(subsys->passthru_ctrl_path);
+}