From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Debonzi Subject: Re: [Scst-devel] Discussion about SCST sysfs layout and implementation. Date: Thu, 23 Apr 2009 13:11:40 -0300 Message-ID: <49F0933C.6040009@linux.vnet.ibm.com> References: <49E7307A.8000205@vlnb.net> <49E77795.7080204@linux.vnet.ibm.com> <49E85F1C.7040106@vlnb.net> <49E8832F.6070302@linux.vnet.ibm.com> <49E88E3F.8030107@vlnb.net> <49E891C8.1050007@emulex.com> <49E8BFB2.50608@vlnb.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from e24smtp03.br.ibm.com ([32.104.18.24]:35333 "EHLO e24smtp03.br.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751344AbZDWQLq (ORCPT ); Thu, 23 Apr 2009 12:11:46 -0400 In-Reply-To: Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Kay Sievers Cc: Vladislav Bolkhovitin , James Smart , "scst-devel@lists.sourceforge.net" , "linux-kernel@vger.kernel.org" , "linux-scsi@vger.kernel.org" Hi all, I was off those days due to a long holiday here in Brazil. Now I am getting back to it. Kay Sievers wrote: > On Fri, Apr 17, 2009 at 19:56, Kay Sievers wrote: >> On Fri, Apr 17, 2009 at 19:43, Vladislav Bolkhovitin wrote: >>> Thank you for the suggestion. If nobody objects, we will go with >>> /sys/class/scst_tgt. >> On Fri, Apr 17, 2009 at 19:43, Vladislav Bolkhovitin wrote: >>> I agree, looks like using struct device instead of struct kobject should >>> additionally complicate the code a lot for not clear gain. >> Thes both replies together suggest that you miss how sysfs and the >> driver core works. Please go and read the current code, and look at >> sysfs, before trying anything like this. >> >> There is no way to add any stuff to /sys/class/scst_tgt/ without using >> proper "struct device" objects. >> >> For the same reason we will not have a disconnected device tree, we >> will not havet any raw kobject in the /sys/devices, /sys/class, >> /sys/bus directories. > > As a starting point, consider creating a "scst" bus_type. Then make > sure all devices you need are uniquely named, so they can be in a flat > list in /sys/bus/scst/devices/. > > Then add all the devices as struct_device to the tree, maybe use an > existing parent struct_device (like a pci device) if you have one, or > create a custom one in /sys/devices/ if there is nothing to use. > > All the devices you add will show up in a hierarchy in /sys/devices/ > depending on the parent information you supply, and every single > device of your subsystem will be listed in a flat list in > /sys/bus/scst/devices/*. You will also get proper events for userspace > that way. > > The question is where the actual block devices hang off, and if they > can use one of the created scst devices, or if they will be virtual > ones? Vlad, how do you think we should move on it? Do you want me to try to go deeper on it and make a new plan/propose or would you like to reformulate the RFC you did? As you all know my knowledge still limited on this subject so I don't feel comfortable to make this sort of decisions at this moments. Regards, Daniel Debonzi