Re: [PATCH v3 3/4] cxl/mem: Do not rely on device_add() side effects for dev_set_name() failures

From: Jason Gunthorpe
Date: Wed Mar 31 2021 - 09:10:59 EST


On Tue, Mar 30, 2021 at 04:36:42PM -0700, Dan Williams wrote:
> +static int cxl_mem_add_memdev(struct cxl_mem *cxlm)
> +{
> + struct cxl_memdev *cxlmd;
> + struct device *dev;
> + struct cdev *cdev;
> + int rc;
> +
> + cxlmd = cxl_memdev_alloc(cxlm);
> + if (IS_ERR(cxlmd))
> + return PTR_ERR(cxlmd);
> +
> + dev = &cxlmd->dev;
> + rc = dev_set_name(dev, "mem%d", cxlmd->id);
> + if (rc)
> + goto err;
>
> + cdev = &cxlmd->cdev;
> cxl_memdev_activate(cxlmd, cxlm);
> rc = cdev_device_add(cdev, dev);
> if (rc)
> - goto err_add;
> + goto err;

It might read nicer to have the error unwind here just call cxl_memdev_unregister()

> - return devm_add_action_or_reset(&pdev->dev, cxl_memdev_unregister,
> + return devm_add_action_or_reset(dev->parent, cxl_memdev_unregister,
> cxlmd);

Since that is what the error unwind does at this point.

>
> -err_add:
> +err:
> /*
> * The cdev was briefly live, shutdown any ioctl operations that
> * saw that state.
> */
> cxl_memdev_shutdown(cxlmd);

Then this doesn't need to be a function

But it is OK as is

Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>

Jason