Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753057Ab3J3QXq (ORCPT ); Wed, 30 Oct 2013 12:23:46 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:46264 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751630Ab3J3QXo (ORCPT ); Wed, 30 Oct 2013 12:23:44 -0400 Date: Wed, 30 Oct 2013 09:23:42 -0700 From: Greg KH To: Paolo Bonzini Cc: Raghavendra K T , Linus Torvalds , Tim Gardner , Linux Kernel Mailing List , the arch/x86 maintainers , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Gleb Natapov , Marcelo Tosatti , KVM list , Al Viro Subject: Re: [PATCH 3.12-rc7] KVM: Fix modprobe failure for kvm_intel/kvm_amd Message-ID: <20131030162342.GA21211@kroah.com> References: <1383059634-55512-1-git-send-email-tim.gardner@canonical.com> <52700C24.9050001@linux.vnet.ibm.com> <52711121.9030606@linux.vnet.ibm.com> <20131030142359.GA32196@kroah.com> <5271284A.6000002@linux.vnet.ibm.com> <527129D4.3010308@redhat.com> <20131030155930.GA23433@kroah.com> <52712EE9.9050402@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <52712EE9.9050402@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1534 Lines: 41 On Wed, Oct 30, 2013 at 05:08:09PM +0100, Paolo Bonzini wrote: > Il 30/10/2013 16:59, Greg KH ha scritto: > >> > Even if it is okay to exit and not create the files (and I think it's a > >> > bit surprising), I'd like at least a printk to signal what's happening. > >> > But there should be no reason for debugfs directory creation to fail in > >> > the end, except for basic mistakes such as the one that Tim reported, so > >> > I think it's better to report the failure. > > Creation will "fail" if debugfs is not enabled, so spiting out printk > > messages in that case is not a good idea. > > Interestingly, if debugfs is not enabled we are already returning an > error-valued pointer: > > static inline struct dentry *debugfs_create_dir(const char *name, > struct dentry *parent) > { > return ERR_PTR(-ENODEV); > } > > which would oops a lot of the current callers. It will oops? Really? Where? That shouldn't happen at all. > Very few places use the currently correct idiom > > if (IS_ERR(root) || !root) > > but it's very ugly... Perhaps debugfs_create_dir *should* return an > error-valued pointer after all. Or just don't care about the return value, and all will work out just fine, right? thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/