Re: [PATCH 2/2] debugfs: return error values, not NULL

[Greg Kroah-Hartman]

On Wed, Jan 23, 2019 at 11:28:14AM +0100, Greg Kroah-Hartman wrote:
> When an error happens, debugfs should return an error pointer value, not
> NULL.  This will prevent the totally theoretical error where a debugfs
> call fails due to lack of memory, returning NULL, and that dentry value
> is then passed to another debugfs call, which would end up succeeding,
> creating a file at the root of the debugfs tree, but would then be
> impossible to remove (because you can not remove the directory NULL).
> 
> So, to make everyone happy, always return errors, this makes the users
> of debugfs much simpler (they do not have to ever check the return
> value), and everyone can rest easy.
> 
> Reported-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
> Reported-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
> Reported-by: Gary R Hook <ghook@xxxxxxx>
> Reported-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>

Oops, also reported by:
	Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>

I'll go fix that up when I merge this.

greg k-h