From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:52804 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751813AbdC0Mds (ORCPT ); Mon, 27 Mar 2017 08:33:48 -0400 Date: Mon, 27 Mar 2017 14:14:13 +0200 From: Johannes Thumshirn To: Ming Lei Cc: Jens Axboe , linux-block@vger.kernel.org, Christoph Hellwig , Bart Van Assche , Hannes Reinecke Subject: Re: [PATCH v3 2/4] block: add a read barrier in blk_queue_enter() Message-ID: <20170327121413.GB7237@linux-x5ow.site> References: <20170327120658.29864-1-tom.leiming@gmail.com> <20170327120658.29864-3-tom.leiming@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 In-Reply-To: <20170327120658.29864-3-tom.leiming@gmail.com> Sender: linux-block-owner@vger.kernel.org List-Id: linux-block@vger.kernel.org On Mon, Mar 27, 2017 at 08:06:56PM +0800, Ming Lei wrote: > Without the barrier, reading DEAD flag of .q_usage_counter > and reading .mq_freeze_depth may be reordered, then the > following wait_event_interruptible() may never return. > > Reviewed-by: Hannes Reinecke > Signed-off-by: Ming Lei > --- Reviewed-by: Johannes Thumshirn -- Johannes Thumshirn Storage jthumshirn@suse.de +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 N�rnberg GF: Felix Imend�rffer, Jane Smithard, Graham Norton HRB 21284 (AG N�rnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850