From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754679Ab3EPDeV (ORCPT ); Wed, 15 May 2013 23:34:21 -0400 Received: from intranet.asianux.com ([58.214.24.6]:8532 "EHLO intranet.asianux.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753440Ab3EPDeS (ORCPT ); Wed, 15 May 2013 23:34:18 -0400 X-Spam-Score: -100.8 Message-ID: <51945384.9060308@asianux.com> Date: Thu, 16 May 2013 11:33:24 +0800 From: Chen Gang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130110 Thunderbird/17.0.2 MIME-Version: 1.0 To: Tejun Heo CC: "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] kernel/workqueue.c: need call device_remove_file() when failure occurs after called device_create_file() References: <51922D30.8000809@asianux.com> <20130514151752.GB6795@mtj.dyndns.org> <5192EFE0.4040903@asianux.com> <5193277A.3040506@asianux.com> <20130515212228.GE26222@htj.dyndns.org> In-Reply-To: <20130515212228.GE26222@htj.dyndns.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/16/2013 05:22 AM, Tejun Heo wrote: > On Wed, May 15, 2013 at 02:13:14PM +0800, Chen Gang wrote: >> >> In workqueue_sysfs_register(), when failure occurs after called >> device_create_file(), need call device_remove_file() to release the >> related resources, then call device_unregister(). >> >> Or it will cause issue. >> >> For individual 'device_attributs' (just like our case), need call >> device_remove_file() explictly and then call device_unregister(), >> please reference drivers/base/*.c (e.g node.c or cpu.c). > > Hmm... isn't this already taken care of by __sysfs_remove_dir() which > device_unregister() calls? That function removes all non-directory > files under the directory being removed. > It just like what you said: device_unregister() -> kobject_del() -> sysfs_remove_dir() -> __sysfs_remove_dir() -> sysfs_remove_one() But: device_remove_file() -> sysfs_remove_file() -> ... sysfs_attr_ns() -> ops->namespace() (such as device_namespace() in workqueue.c) ... sysfs_hash_and_remove() -> sysfs_remove_one(). So if not call device_remove_file() explicitly, the device_namespace() may be not called. Even in device_unregister(), it still call device_remove_file() to release the related attributes firstly, then call kobject_del(). Thanks. -- Chen Gang Asianux Corporation