1 files changed, 37 insertions, 5 deletions

diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index a2325330bf22..bd87dfd173a4 100644
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -676,10 +676,18 @@ static ssize_t nvmet_ns_enable_store(struct config_item *item,
 	if (kstrtobool(page, &enable))
 		return -EINVAL;
 
+	/*
+	 * take a global nvmet_config_sem because the disable routine has a
+	 * window where it releases the subsys-lock, giving a chance to
+	 * a parallel enable to concurrently execute causing the disable to
+	 * have a misaccounting of the ns percpu_ref.
+	 */
+	down_write(&nvmet_config_sem);
 	if (enable)
 		ret = nvmet_ns_enable(ns);
 	else
 		nvmet_ns_disable(ns);
+	up_write(&nvmet_config_sem);
 
 	return ret ? ret : count;
 }
@@ -754,6 +762,18 @@ static struct configfs_attribute *nvmet_ns_attrs[] = {
 	NULL,
 };
 
+bool nvmet_subsys_nsid_exists(struct nvmet_subsys *subsys, u32 nsid)
+{
+	struct config_item *ns_item;
+	char name[12];
+
+	snprintf(name, sizeof(name), "%u", nsid);
+	mutex_lock(&subsys->namespaces_group.cg_subsys->su_mutex);
+	ns_item = config_group_find_item(&subsys->namespaces_group, name);
+	mutex_unlock(&subsys->namespaces_group.cg_subsys->su_mutex);
+	return ns_item != NULL;
+}
+
 static void nvmet_ns_release(struct config_item *item)
 {
 	struct nvmet_ns *ns = to_nvmet_ns(item);
@@ -1995,11 +2015,17 @@ static struct config_group nvmet_ports_group;
 static ssize_t nvmet_host_dhchap_key_show(struct config_item *item,
 		char *page)
 {
-	u8 *dhchap_secret = to_host(item)->dhchap_secret;
+	u8 *dhchap_secret;
+	ssize_t ret;
 
+	down_read(&nvmet_config_sem);
+	dhchap_secret = to_host(item)->dhchap_secret;
 	if (!dhchap_secret)
-		return sprintf(page, "\n");
-	return sprintf(page, "%s\n", dhchap_secret);
+		ret = sprintf(page, "\n");
+	else
+		ret = sprintf(page, "%s\n", dhchap_secret);
+	up_read(&nvmet_config_sem);
+	return ret;
 }
 
 static ssize_t nvmet_host_dhchap_key_store(struct config_item *item,
@@ -2023,10 +2049,16 @@ static ssize_t nvmet_host_dhchap_ctrl_key_show(struct config_item *item,
 		char *page)
 {
 	u8 *dhchap_secret = to_host(item)->dhchap_ctrl_secret;
+	ssize_t ret;
 
+	down_read(&nvmet_config_sem);
+	dhchap_secret = to_host(item)->dhchap_ctrl_secret;
 	if (!dhchap_secret)
-		return sprintf(page, "\n");
-	return sprintf(page, "%s\n", dhchap_secret);
+		ret = sprintf(page, "\n");
+	else
+		ret = sprintf(page, "%s\n", dhchap_secret);
+	up_read(&nvmet_config_sem);
+	return ret;
 }
 
 static ssize_t nvmet_host_dhchap_ctrl_key_store(struct config_item *item,