From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752716Ab3IVRAL (ORCPT ); Sun, 22 Sep 2013 13:00:11 -0400 Received: from mail-qe0-f48.google.com ([209.85.128.48]:49787 "EHLO mail-qe0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752252Ab3IVRAK (ORCPT ); Sun, 22 Sep 2013 13:00:10 -0400 Date: Sun, 22 Sep 2013 13:00:05 -0400 From: Tejun Heo To: Tomoki Sekiyama Cc: linux-kernel@vger.kernel.org, axboe@kernel.dk, seiji.aguchi@hds.com, vgoyal@redhat.com, majianpeng@gmail.com Subject: Re: [PATCH v2 2/2] elevator: acquire q->sysfs_lock in elevator_change() Message-ID: <20130922170005.GE30946@htj.dyndns.org> References: <20130830224707.21812.63516.stgit@hds.com> <20130830224716.21812.99333.stgit@hds.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130830224716.21812.99333.stgit@hds.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 30, 2013 at 06:47:16PM -0400, Tomoki Sekiyama wrote: > Add locking of q->sysfs_lock into elevator_change() (an exported function) > to ensure it is held to protect q->elevator from elevator_init(), even if > elevator_change() is called from non-sysfs paths. > sysfs path (elv_iosched_store) uses __elevator_change(), non-locking > version, as the lock is already taken by elv_iosched_store(). > > Signed-off-by: Tomoki Sekiyama Acked-by: Tejun Heo Thanks. -- tejun