From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3BFFFC432C0 for ; Wed, 27 Nov 2019 18:17:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 11FF520835 for ; Wed, 27 Nov 2019 18:17:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574878643; bh=VWX/yO9DaPITM0/vWZ09RFb6PLBlIB3+UWPycaDaxB8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=shSJE+cSUyOTUppWXykL1WyDxOQtu+MUB52AXWbBM3l6eRIz6W4iZp3273naMTOqW AupaEUPOp5/3U+28ZyEaqCzgVzP1rnwqDc+GC2sWR/6ZNpsALNWKr68/CNwoyB2s9w CRYOi8w+Du9IUNoEhSWdKAJdS0cUUXYijWN9wLC0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726633AbfK0SRW (ORCPT ); Wed, 27 Nov 2019 13:17:22 -0500 Received: from mail.kernel.org ([198.145.29.99]:46232 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726576AbfK0SRW (ORCPT ); Wed, 27 Nov 2019 13:17:22 -0500 Received: from localhost (unknown [104.132.0.81]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D48F32070B; Wed, 27 Nov 2019 18:17:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574878641; bh=VWX/yO9DaPITM0/vWZ09RFb6PLBlIB3+UWPycaDaxB8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jgyOx1vKWxkW0yxbl7C59Wjk3T+MSlcQg8O2p4fz9nW1rcCmaKWxWA4nzv9kO22xU KGnwN+CUYiurs5pkZo5sj9FDYvHwVEtC1lWPtfiRAp2f5wrtB0jXqXS9XJLLNLjSAF AjRy8KvaDoeDnFOR70IKajHfcLOX60ehHM9QOb0k= Date: Wed, 27 Nov 2019 10:17:21 -0800 From: Jaegeuk Kim To: Bart Van Assche Cc: Jens Axboe , linux-block@vger.kernel.org Subject: Re: [PATCH v2] loop: avoid EAGAIN, if offset or block_size are changed Message-ID: <20191127181721.GA41818@jaegeuk-macbookpro.roam.corp.google.com> References: <4ab43c9d-8b95-7265-2b55-b6d526938b32@acm.org> <20191126182907.GA5510@jaegeuk-macbookpro.roam.corp.google.com> <73eb7776-6f13-8dce-28ae-270a90dda229@acm.org> <20191126223204.GA20652@jaegeuk-macbookpro.roam.corp.google.com> <20191127000407.GC20652@jaegeuk-macbookpro.roam.corp.google.com> <3ca36251-57c4-b62c-c029-77b643ddea77@acm.org> <20191127010926.GA34613@jaegeuk-macbookpro.roam.corp.google.com> <5e322380-0f3a-59ad-9d0d-2e1a4a9b676e@acm.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5e322380-0f3a-59ad-9d0d-2e1a4a9b676e@acm.org> User-Agent: Mutt/1.8.2 (2017-04-18) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 11/27, Bart Van Assche wrote: > On 11/26/19 5:09 PM, Jaegeuk Kim wrote: > > + if (drop_request) > > + blk_set_queue_dying(lo->lo_queue); > > /* I/O need to be drained during transfer transition */ > > blk_mq_freeze_queue(lo->lo_queue); > > Since blk_set_queue_dying() calls blk_freeze_queue_start(), I think the > above code will increase q->mq_freeze_depth by one or by two depending on > which path is taken. How about changing the above code into the following: > > if (drop_request) { > blk_set_queue_dying(lo->lo_queue); > blk_mq_freeze_queue_wait(lo->lo_queue); > } else { > blk_mq_freeze_queue(lo->lo_queue); > } Done. > > Otherwise this patch looks good to me. > > Thanks, > > Bart.