Re: [PATCH] nvme-hwmon: don't return errors from nvme_hwmon_init

[Christoph Hellwig <hch@lst.de>]

On Tue, Oct 18, 2022 at 06:31:36PM +0300, Serge Semin wrote:
> What about just taking the -EINTR error into account by the
> nvme_hwmon_init() caller and ignore any other there? Meanwhile you can
> convert the nvme_hwmon_init() method to return any error including the
> ENOMEM. Thus the function will be more consistent and will have
> independent from the caller context design.

Yeah, that actually looks a tad cleaner than what I just sent out:

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 9cbe7854d4883..7c949f44e1db2 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3261,9 +3261,13 @@ int nvme_init_ctrl_finish(struct nvme_ctrl *ctrl)
 	if (ret < 0)
 		return ret;
 
+	/*
+	 * Do not return errors unless we are in a controller reset.
+	 * The controller works perfectly fine without the hwmon registration.
+	 */
 	if (!ctrl->identified && !nvme_discovery_ctrl(ctrl)) {
 		ret = nvme_hwmon_init(ctrl);
-		if (ret < 0)
+		if (err == -EINTR)
 			return ret;
 	}
 
diff --git a/drivers/nvme/host/hwmon.c b/drivers/nvme/host/hwmon.c
index 0a586d7129201..23918bb7bdca2 100644
--- a/drivers/nvme/host/hwmon.c
+++ b/drivers/nvme/host/hwmon.c
@@ -230,7 +230,7 @@ int nvme_hwmon_init(struct nvme_ctrl *ctrl)
 
 	data = kzalloc(sizeof(*data), GFP_KERNEL);
 	if (!data)
-		return 0;
+		return -ENOMEM;
 
 	data->ctrl = ctrl;
 	mutex_init(&data->read_lock);
@@ -238,8 +238,7 @@ int nvme_hwmon_init(struct nvme_ctrl *ctrl)
 	err = nvme_hwmon_get_smart_log(data);
 	if (err) {
 		dev_warn(dev, "Failed to read smart log (error %d)\n", err);
-		kfree(data);
-		return err;
+		goto err_free_data;
 	}
 
 	hwmon = hwmon_device_register_with_info(dev, "nvme",
@@ -247,11 +246,15 @@ int nvme_hwmon_init(struct nvme_ctrl *ctrl)
 						NULL);
 	if (IS_ERR(hwmon)) {
 		dev_warn(dev, "Failed to instantiate hwmon device\n");
-		kfree(data);
-		return PTR_ERR(hwmon);
+		err = PTR_ERR(hwmon);
+		goto err_free_data;
 	}
 	ctrl->hwmon_device = hwmon;
 	return 0;
+
+err_free_data:
+	kfree(data);
+	return err;
 }
 
 void nvme_hwmon_exit(struct nvme_ctrl *ctrl)