Re: [PATCH] kvm: no need to check return value of debugfs_create functions

From: Sean Christopherson
Date: Tue Jan 22 2019 - 12:29:15 EST


On Tue, Jan 22, 2019 at 09:21:02AM -0800, Sean Christopherson wrote:
> On Tue, Jan 22, 2019 at 04:21:50PM +0100, Greg Kroah-Hartman wrote:
> > When calling debugfs functions, there is no need to ever check the
> > return value. The function can work or not, but the code logic should
> > never do something different based on this.
>
> What about wanting to make the debugfs all-or-nothing? That seems like
> a legitimate usage of checking the return value.
>
> E.g. KVM removes the debugfs if kvm_arch_create_vcpu_debugfs() fails, and
> the arch/x86/kvm/debugfs.c implementation of kvm_arch_create_vcpu_debugfs()
> returns an error if any of its debugfs_create_file() calls fail.
>
> If you're adamant about removing all debugfs create return value checks,
> the aforementioned debugfs_create_file() calls should also be removed.
> And at that point kvm_create_vcpu_debugfs() should have a 'void' return
> value.

Belatedly saw the other series. It'll require a bit more coordination,
but folding this into the x86 series would allow for converting the KVM
call stack to have 'void' returns.