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 3774DC433EF for ; Wed, 10 Nov 2021 09:14:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 11F9F61186 for ; Wed, 10 Nov 2021 09:14:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229831AbhKJJQ5 (ORCPT ); Wed, 10 Nov 2021 04:16:57 -0500 Received: from verein.lst.de ([213.95.11.211]:53580 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229781AbhKJJQ4 (ORCPT ); Wed, 10 Nov 2021 04:16:56 -0500 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) Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.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?