Re: [PATCH 5/5] staging: pi433: Remove duplicated code using the "goto" error recovery scheme.

Dan Carpenter
2024-03-28T14:03:22Z

On Thu, Mar 28, 2024 at 02:12:44PM +0200, Shahar Avidar wrote:
> pi433_init had "unregister_chrdev" called twice.
> Remove it using goto statements.
>
> Signed-off-by: Shahar Avidar <ikobh7@gmail.com>
> ---
> drivers/staging/pi433/pi433_if.c | 23 ++++++++++++-----------
> 1 file changed, 12 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/staging/pi433/pi433_if.c b/drivers/staging/pi433/pi433_if.c
> index 62ce75b07bf0..e538f1d4e787 100644
> --- a/drivers/staging/pi433/pi433_if.c
> +++ b/drivers/staging/pi433/pi433_if.c
> @@ -1400,24 +1400,25 @@ static int __init pi433_init(void)
> */
> status = alloc_chrdev_region(&pi433_devt, 0, N_PI433_MINORS, "pi433");
> if (status < 0)
> - return status;
> + goto fail;

Just return directly. Do nothing gotos are bad for readability and they
create Forgot to Set the Error Code bugs. Also there was a direct
return earlier in the function so it's better to do things consistently.

>
> status = class_register(&pi433_class);
> - if (status) {
> - unregister_chrdev(MAJOR(pi433_devt),
> - pi433_spi_driver.driver.name);
> - return status;
> - }
> + if (status)
> + goto unreg_chrdev;
>
> root_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
>
> status = spi_register_driver(&pi433_spi_driver);
> - if (status < 0) {
> - class_unregister(&pi433_class);
> - unregister_chrdev(MAJOR(pi433_devt),
> - pi433_spi_driver.driver.name);
> - }
> + if (status < 0)
> + goto unreg_class;
>
> + return 0;
> +
> +unreg_class:
> + class_unregister(&pi433_class);

There is a debugfs_remove() missing. I have written a blog that might
be helpful:

https://staticthinking.wordpress.com/2022/04/28/free-the-last-thing-style/

regards,
dan carpenter

> +unreg_chrdev:
> + unregister_chrdev(MAJOR(pi433_devt), pi433_spi_driver.driver.name);
> +fail:
> return status;
> }