1 files changed, 23 insertions, 27 deletions

diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index 635a7cb45d0b..e5dbd1923b7b 100644
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -1118,16 +1118,12 @@ static ssize_t nvmet_subsys_attr_model_show(struct config_item *item,
 					    char *page)
 {
 	struct nvmet_subsys *subsys = to_subsys(item);
-	struct nvmet_subsys_model *subsys_model;
-	char *model = NVMET_DEFAULT_CTRL_MODEL;
 	int ret;
 
-	rcu_read_lock();
-	subsys_model = rcu_dereference(subsys->model);
-	if (subsys_model)
-		model = subsys_model->number;
-	ret = snprintf(page, PAGE_SIZE, "%s\n", model);
-	rcu_read_unlock();
+	mutex_lock(&subsys->lock);
+	ret = snprintf(page, PAGE_SIZE, "%s\n", subsys->model_number ?
+			subsys->model_number : NVMET_DEFAULT_CTRL_MODEL);
+	mutex_unlock(&subsys->lock);
 
 	return ret;
 }
@@ -1138,14 +1134,17 @@ static bool nvmet_is_ascii(const char c)
 	return c >= 0x20 && c <= 0x7e;
 }
 
-static ssize_t nvmet_subsys_attr_model_store(struct config_item *item,
-					     const char *page, size_t count)
+static ssize_t nvmet_subsys_attr_model_store_locked(struct nvmet_subsys *subsys,
+		const char *page, size_t count)
 {
-	struct nvmet_subsys *subsys = to_subsys(item);
-	struct nvmet_subsys_model *new_model;
-	char *new_model_number;
 	int pos = 0, len;
 
+	if (subsys->model_number) {
+		pr_err("Can't set model number. %s is already assigned\n",
+		       subsys->model_number);
+		return -EINVAL;
+	}
+
 	len = strcspn(page, "\n");
 	if (!len)
 		return -EINVAL;
@@ -1155,28 +1154,25 @@ static ssize_t nvmet_subsys_attr_model_store(struct config_item *item,
 			return -EINVAL;
 	}
 
-	new_model_number = kmemdup_nul(page, len, GFP_KERNEL);
-	if (!new_model_number)
+	subsys->model_number = kmemdup_nul(page, len, GFP_KERNEL);
+	if (!subsys->model_number)
 		return -ENOMEM;
+	return count;
+}
 
-	new_model = kzalloc(sizeof(*new_model) + len + 1, GFP_KERNEL);
-	if (!new_model) {
-		kfree(new_model_number);
-		return -ENOMEM;
-	}
-	memcpy(new_model->number, new_model_number, len);
+static ssize_t nvmet_subsys_attr_model_store(struct config_item *item,
+					     const char *page, size_t count)
+{
+	struct nvmet_subsys *subsys = to_subsys(item);
+	ssize_t ret;
 
 	down_write(&nvmet_config_sem);
 	mutex_lock(&subsys->lock);
-	new_model = rcu_replace_pointer(subsys->model, new_model,
-					mutex_is_locked(&subsys->lock));
+	ret = nvmet_subsys_attr_model_store_locked(subsys, page, count);
 	mutex_unlock(&subsys->lock);
 	up_write(&nvmet_config_sem);
 
-	kfree_rcu(new_model, rcuhead);
-	kfree(new_model_number);
-
-	return count;
+	return ret;
 }
 CONFIGFS_ATTR(nvmet_subsys_, attr_model);