From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752821Ab2G0SZu (ORCPT ); Fri, 27 Jul 2012 14:25:50 -0400 Received: from out3-smtp.messagingengine.com ([66.111.4.27]:46539 "EHLO out3-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752441Ab2G0SZt (ORCPT ); Fri, 27 Jul 2012 14:25:49 -0400 X-Sasl-enc: BAZBvo+plubMPbK2a1Y/9BDd9HPfsQDwKdpuY9AZJKde 1343413548 Date: Fri, 27 Jul 2012 11:25:46 -0700 From: Greg KH To: Matthew Wilcox Cc: Keith Busch , linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, Alan Cox Subject: Re: [PATCH] NVMe: Add a character device for each nvme device Message-ID: <20120727182546.GA23874@kroah.com> References: <1343407458-29909-1-git-send-email-keith.busch@intel.com> <20120727181212.GM22985@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120727181212.GM22985@linux.intel.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 On Fri, Jul 27, 2012 at 02:12:12PM -0400, Matthew Wilcox wrote: > On Fri, Jul 27, 2012 at 10:44:18AM -0600, Keith Busch wrote: > > Registers a character device for the nvme module and creates character > > files as /dev/nvmeN for each nvme device probed, where N is the device > > instance. The character devices support nvme admin ioctl commands so > > that nvme devices without namespaces can be managed. > > I don't see a problem here, but I'm no expert at sysfs / character devices. > Alan, Greg, anyone else see any problems with how this character device is > created / destroyed? Yes, see below: > > + device_create(nvme_char_cl, NULL, MKDEV(nvme_char_major, dev->instance), > > + NULL, "nvme%d", dev->instance); You just created a device at the "root" of sysfs, which is wrong, especially when you do have a parent device here. Please use it. Also, why are you creating your own class? Can't this just be a misc device? And if you want to create your own class, please don't, use a bus, as that is what is really happening here, right? We are trying to move away from using 'struct class' wherever possible (one of these days we'll just remove it...) thanks, greg k-h