Re: [PATCH] kvm: remove invalid check for debugfs_create_dir()

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Wed, Jun 12, 2019 at 08:40:21AM -0700, Sean Christopherson wrote:
> On Wed, Jun 12, 2019 at 04:50:33PM +0200, Greg Kroah-Hartman wrote:
> > debugfs_create_dir() can never return NULL, so no need to check for an
> > impossible thing.
> > 
> > It's also not needed to ever check the return value of this function, so
> > just remove the check entirely, and indent the previous line to a sane
> > formatting :)
> > 
> > Cc: Paolo Bonzini <pbonzini@redhat.com>
> > Cc: "Radim Krčmář" <rkrcmar@redhat.com>
> > Cc: kvm@vger.kernel.org
> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > ---
> >  virt/kvm/kvm_main.c | 4 +---
> >  1 file changed, 1 insertion(+), 3 deletions(-)
> > 
> > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> > index ca54b09adf5b..4b4ef642d8fa 100644
> > --- a/virt/kvm/kvm_main.c
> > +++ b/virt/kvm/kvm_main.c
> > @@ -2605,9 +2605,7 @@ static int kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
> >  
> >  	snprintf(dir_name, sizeof(dir_name), "vcpu%d", vcpu->vcpu_id);
> >  	vcpu->debugfs_dentry = debugfs_create_dir(dir_name,
> > -								vcpu->kvm->debugfs_dentry);
> > -	if (!vcpu->debugfs_dentry)
> > -		return -ENOMEM;
> > +						  vcpu->kvm->debugfs_dentry);
> >  
> >  	ret = kvm_arch_create_vcpu_debugfs(vcpu);
> >  	if (ret < 0) {
> > -- 
> > 2.22.0
> 
> Any objection to me pulling this into a series to clean up similar issues
> in arch/x86/kvm/debugfs.c -> kvm_arch_create_vcpu_debugfs(), and to
> change kvm_create_vcpu_debugfs() to not return success/failure?  It'd be
> nice to fix everything in a single shot.

It was on my todo list to do the cleanup of the x86 kvm stuff.  I
figured this arch-neutral fix was independent, but if you want me to do
it all at once, I'll be glad to do so later this week.

thanks,

greg k-h