Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752726Ab1FRTzj (ORCPT ); Sat, 18 Jun 2011 15:55:39 -0400 Received: from mail-gx0-f174.google.com ([209.85.161.174]:46151 "EHLO mail-gx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751345Ab1FRTzg convert rfc822-to-8bit (ORCPT ); Sat, 18 Jun 2011 15:55:36 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=vrfy.org; s=google; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type:content-transfer-encoding; b=NhwoBkcYEuhs4R9FoKUa8aeccEZlBRYpB3nCcQtK6XiOp83g9qbeQONVL6gQEhXerC SaJIUoloA+PDhs9NFyUbWEmUuYBkILlCGoz1HLnsbfcx6hYUPFXEoLYZIDgWJIBAgr0O O21zwgqkxWf5LJdPve4uBpGkDLLmDTGvwOXAQ= MIME-Version: 1.0 In-Reply-To: <1308426017.2586.1273.camel@mulgrave> References: <20110616181943.GB1439@kroah.com> <1308256290.2436.143.camel@mulgrave> <1308264321.2436.161.camel@mulgrave> <1308320844.2586.14.camel@mulgrave> <1308322193.2586.30.camel@mulgrave> <20110617162247.GA16261@kroah.com> <1308426017.2586.1273.camel@mulgrave> From: Kay Sievers Date: Sat, 18 Jun 2011 21:55:20 +0200 Message-ID: Subject: Re: [PATCH 1/3] [RFC] genhd: add a new attribute in device structure To: James Bottomley Cc: Greg KH , Nao Nishijima , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, jcm@redhat.com, hare@suse.de, stefanr@s5r6.in-berlin.de, yrl.pp-manager.tt@hitachi.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2918 Lines: 62 On Sat, Jun 18, 2011 at 21:40, James Bottomley wrote: > On Fri, 2011-06-17 at 09:22 -0700, Greg KH wrote: >> On Fri, Jun 17, 2011 at 06:12:14PM +0200, Kay Sievers wrote: >> > On Fri, Jun 17, 2011 at 17:39, Kay Sievers wrote: >> > > On Fri, Jun 17, 2011 at 16:49, James Bottomley >> > >> > >> So this is subsystem specific.  For the case of a SCSI enclosure, I can >> > >> answer that it's actually burned into the enclosure firmware.  When you >> > >> build an enclosure with labels, the label names are stored in a >> > >> diagnostic page.  We can actually interrogate the enclosure directly or >> > >> use the ses driver to get these names mapped to current devices. >> > > >> > > To me this sounds like a nice name on top of the current bunch of >> > > names, not like a 'preferred' name. >> > > >> > > I still don't like to introduce any new facility to the kernel that >> > > can handle only one single name. Reality the last years has taught us >> > > a very different story, and we've walked a long way to get where we >> > > are. I really don't believe single names will ever work, it's just a >> > > nice theory. >> > >> > I might need to clarify this a bit. >> > >> > I have no problem in general to add a 'alias' to every disk, and use >> > that when stuff is logged. Just the same way the netifs have an alias. >> > Sure, it might be useful for some use cases. And if that helps to >> > solve any real problem, we should just do it. >> > >> > I just want to make clear, that I don't think that it is anywhere near >> > to a solution for the problems which are described here. And that >> > nobody should see this as an excuse not to get their stuff together >> > and work on the problem, which is that we don't have machine-readable >> > error and debug from the kernel and a smart syslog. >> > >> > If we had that, I'm very sure nobody would even ask for a 'pretty >> > name' in the kernel, and I think that is a good indication that we are >> > not on the right track here. >> >> And I totally agree here, which is why I don't want to accept this >> change to the driver core to add this, as it's not the correct solution. > > OK, fine ... we'll do it as gendisk only then.  I suppose that is the > 95% use case anyway. Sounds fine. It's probably easier to have it domain-specific anyway. Just like the netif alias already is. I would suggest not to call it 'preferred' though, but something similar to 'alias'. Having /dev/disk/by-preferred/ doesn't sound too convincing to me. An 'change' uevent when the alias is set sounds fine. I don't think a set-once policy is needed. Thanks, Kay -- 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/