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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 662BFC433F5 for ; Wed, 10 Nov 2021 09:14:21 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1E5DA61186 for ; Wed, 10 Nov 2021 09:14:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 1E5DA61186 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:MIME-Version: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=nndBfNfqhcbOI8YYGBnx8yCkSa49zwNeoRFjXuHDD8M=; b=14dgcR5GGl/FXfaHtobh4LQLtu VQhTqyRShbEsVWVawmK6hBlspcU94ATdGU3CGffzKDSLJ0XEAOL9PxsJGkXY3AQVCS9gLVX84a+87 6upRaDPTDmek7eG7lfWf+2g1dPbnOMRSwDoXlV4HiaeHOk6VuFmHsNdXibTW2Gh9xZaBaqlu29GRx QnGD5VtChZyC/UpEKhchImsKoOiNqRBvaL2jWE3yXgPHM/0UIcucS3dO1AMPGWu0ulBozJaJtOLsr /81oor/TLBdYejxAkn8/Ad6JWh19U8exUWKPgGFb4Dfc0hbDXHYmJA/wIlwsM2tmEHvMGhwzhqEqc nYG5MpwQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mkjgO-004xag-1G; Wed, 10 Nov 2021 09:14:16 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mkjgK-004xZK-TW for linux-nvme@lists.infradead.org; Wed, 10 Nov 2021 09:14:14 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 966DD68AA6; Wed, 10 Nov 2021 10:14:07 +0100 (CET) Date: Wed, 10 Nov 2021 10:14:07 +0100 From: Christoph Hellwig To: Jens Axboe , Ming Lei Cc: linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, linux-nvme@lists.infradead.org Subject: sorting out the freeze / quiesce mess Message-ID: <20211110091407.GA8396@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211110_011413_139588_81146BB7 X-CRM114-Status: UNSURE ( 9.34 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org Hi Jens and Ming, I've been looking into properly supporting queue freezing for bio based drivers (that is only release q_usage_counter on bio completion for them). And the deeper I look into the code the more I'm confused by us having the blk_mq_quiesce* interface in addition to blk_freeze_queue. What is a good reason to do a quiesce separately from a freeze?