Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757576Ab0G2OXK (ORCPT ); Thu, 29 Jul 2010 10:23:10 -0400 Received: from mail-yx0-f174.google.com ([209.85.213.174]:44423 "EHLO mail-yx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754238Ab0G2OXI convert rfc822-to-8bit (ORCPT ); Thu, 29 Jul 2010 10:23:08 -0400 MIME-Version: 1.0 In-Reply-To: <4C518AC9.4040208@redhat.com> References: <20100722101541.GU15652@nb.net.home> <1280410435-7017-1-git-send-email-mbroz@redhat.com> <4C518AC9.4040208@redhat.com> From: Kay Sievers Date: Thu, 29 Jul 2010 16:22:50 +0200 Message-ID: Subject: Re: [PATCH] loop: add some basic read-only sysfs attributes To: Milan Broz Cc: util-linux-ng@vger.kernel.org, linux-kernel@vger.kernel.org, kzak@redhat.com, axboe@kernel.dk 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: 1359 Lines: 31 On Thu, Jul 29, 2010 at 16:06, Milan Broz wrote: > On 07/29/2010 03:47 PM, Kay Sievers wrote: >> On Thu, Jul 29, 2010 at 15:33, Milan Broz wrote: >>> Create /sys/block/loopX/loop directory and provide these attributes: >>>  - backing_file >>>  - autoclear >>>  - offset >>>  - sizelimit >>> >>> To be used in util-linux-ng (and possibly elsewhere like udev rules) >>> where code need to get loop attributes from kernel (and not store >>> duplicate info in userspace). >> >> Isn't it that the loop attributes are created _after_ the loopdev is >> registered? That would make it hard to use these attributes from udev, >> as the event is already running while they are created. > > First 8 loop devices are registered always (without backing file), > so you have wait for change event initiated from fd set ioctl anyway... > (backing file attribute is empty in that case) Ah, so we are sure, we always get a 'change' event, and before that, none of these values are ever useful to read? I mean, there will not be attributes that are interesting during an 'add' event? 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/