Re: [PATCH 1/2] quickstats, kernel sample collector

[Greg KH]

On Tue, Feb 25, 2020 at 06:30:26PM -0800, Luigi Rizzo wrote:
> +static int __init ks_init(void)
> +{
> +	ks_root = debugfs_create_dir("kstats", NULL);
> +	if (IS_ERR_OR_NULL(ks_root)) {
> +		pr_warn("kstats: cannot create debugfs root\n");
> +		return PTR_ERR(ks_root);
> +	}

Do not check debugfs_create_* calls as there is no need to.  Just take
the return value (if you care to use it again) and move on.

Also, the check you made here is incorrect :)

> +	ks_control_dentry = debugfs_create_file("_control", 0644, ks_root,
> +						NULL, &ks_file_ops);
> +	if (IS_ERR_OR_NULL(ks_control_dentry)) {
> +		pr_warn("kstats: cannot create kstats/_control\n");
> +		debugfs_remove_recursive(ks_root);
> +		return PTR_ERR(ks_control_dentry);
> +	}

Same here, just call debugfs_create_file and move on.

You do this same thing in other places too.

thanks,

greg k-h