From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750794AbVLOQy1 (ORCPT ); Thu, 15 Dec 2005 11:54:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750812AbVLOQy1 (ORCPT ); Thu, 15 Dec 2005 11:54:27 -0500 Received: from mail.kroah.org ([69.55.234.183]:60550 "EHLO perch.kroah.org") by vger.kernel.org with ESMTP id S1750794AbVLOQy0 (ORCPT ); Thu, 15 Dec 2005 11:54:26 -0500 Date: Thu, 15 Dec 2005 08:53:57 -0800 From: Greg KH To: Jeremy Katz Cc: Pete Zaitcev , linux-kernel@vger.kernel.org Subject: Re: "block" symlink in sysfs for a multifunction device Message-ID: <20051215165357.GA15016@kroah.com> References: <20051212134904.225dcc5d.zaitcev@redhat.com> <20051214055019.GA23036@kroah.com> <20051214152615.13b6b105.zaitcev@redhat.com> <20051214234255.GA3275@kroah.com> <1134622055.2864.21.camel@bree.local.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1134622055.2864.21.camel@bree.local.net> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 14, 2005 at 11:47:35PM -0500, Jeremy Katz wrote: > On Wed, 2005-12-14 at 15:42 -0800, Greg KH wrote: > > On Wed, Dec 14, 2005 at 03:26:15PM -0800, Pete Zaitcev wrote: > > > On Tue, 13 Dec 2005 21:50:19 -0800, Greg KH wrote: > > > > $ ls -l /sys/block/uba/device/ > > > > -r--r--r-- 1 root root 4096 Dec 13 21:31 bNumEndpoints > > > > lrwxrwxrwx 1 root root 0 Dec 13 21:31 block:uba -> ../../../../../../block/uba > > > > lrwxrwxrwx 1 root root 0 Dec 13 21:31 block:ubb -> ../../../../../../block/ubb > > > > lrwxrwxrwx 1 root root 0 Dec 13 21:31 block:ubc -> ../../../../../../block/ubc > > > > lrwxrwxrwx 1 root root 0 Dec 13 21:31 block:ubd -> ../../../../../../block/ubd > > > > > > Greg, Jeremy is not happy about this. > > > > > > > https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=175563 > > > > ------- Additional Comments From katzj@redhat.com 2005-12-14 18:05 EST ------- > > > > Actually, this is problematic. It makes it so that the single device directory > > > > corresponds to more than one device which we can't handle with kudzu :-( > > > > Well, how do you handle it for class devices then? > > We don't have any where we need to handle it at present. > > > And if this isn't acceptable, what would be? > > By going this route, it really feels like you're hacking around your own > rule of a single value per file :-) Except that instead of having a > file that I read five values from, it's five files with naming > heuristics to get five values. Which is, in a lot of ways, worse. What? These are symlinks, not files. Why would you want to read the name of the block device from a file and then go have to look that location up, instead of just following the symlink? > I'd much rather see the fact that there are multiple devices be handled > by having each device with its own unique directory. This then keeps > all of the abstractions which currently exist. Those devices do have their own unique directory. Look at the pointer above :) The point here is that multiple class devices and block devices can bind to a single "real device" in the system, and we need to handle that representation properly. We have had the symlink for a while now, and I just forgot to put the proper name on the block device one, to match up with the class device naming. thanks, greg k-h