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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 5B4B2C433F5 for ; Mon, 24 Jan 2022 23:22:33 +0000 (UTC) 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:In-Reply-To:Content-Type: MIME-Version:References: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:List-Owner; bh=roW5J7iac8fftPWGb47ZXrc4wN3kazKOO4vYqBt3HH8=; b=eURJtuknoSXqrBM3ODdakmi8zK mAHfDrmOFqP1lcmGN7HNM/cA+i8+j8b6KUYJNa33BAS8xj9d/7LwE/jJts5q4kwLznZ/10f8xfwL/ uGmh6V/LMqLHl5jgBBeoeSc54gydqEq193kjmQWijyrslGmhthrDOviQheLu0NThUfWHpAc56eVlQ ffbSbH8J0cvQ4sixnMJ/VKGr7cpa+3OHAiv76Te3j5sV9jWYev6bUi73p/nZTpfX1kFqGPZx03t+J ruQJ80+e0/6xxkbi2t+ArGVxPTOx4l3XfczXxxhxr0wd+XuI8aUyOZExhdKj2z5D8BMW68azfvPpC p8PWdGfw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nC8fM-005ZM2-4F; Mon, 24 Jan 2022 23:22:28 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nC8fJ-005ZKp-D9 for linux-nvme@lists.infradead.org; Mon, 24 Jan 2022 23:22:26 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1643066544; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=roW5J7iac8fftPWGb47ZXrc4wN3kazKOO4vYqBt3HH8=; b=WZpSgbHQJvcU9Gmq6qdzUiKoE91YiK/Lq82soHr+MyMo6RkiNX2ZRk+0JLAoDU2nINofaC gQJSpMAISxuCOLQzA2EHJmSMU7MkkgkxQGLZzSPg19hosfSbsVIPuZAQh7FAcT4NSoeLVr 9+JNrKtl5AC+DriNTiObYWuLQuHH19U= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-444-LxYTban4Na-bPjpDFcffpg-1; Mon, 24 Jan 2022 18:22:18 -0500 X-MC-Unique: LxYTban4Na-bPjpDFcffpg-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5AE4F1006AA8; Mon, 24 Jan 2022 23:22:17 +0000 (UTC) Received: from T590 (ovpn-8-21.pek2.redhat.com [10.72.8.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 442025ED55; Mon, 24 Jan 2022 23:21:59 +0000 (UTC) Date: Tue, 25 Jan 2022 07:21:55 +0800 From: Ming Lei To: Christoph Hellwig Cc: Jens Axboe , "Martin K . Petersen" , linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, linux-scsi@vger.kernel.org, Bart Van Assche Subject: Re: [PATCH V2 09/13] scsi: force unfreezing queue into atomic mode Message-ID: References: <20220122111054.1126146-1-ming.lei@redhat.com> <20220122111054.1126146-10-ming.lei@redhat.com> <20220124131516.GH27269@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220124131516.GH27269@lst.de> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220124_152225_541040_C2EC35E9 X-CRM114-Status: GOOD ( 26.45 ) 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 On Mon, Jan 24, 2022 at 02:15:16PM +0100, Christoph Hellwig wrote: > On Sat, Jan 22, 2022 at 07:10:50PM +0800, Ming Lei wrote: > > In scsi_disk_release() request queue is frozen for clearing > > disk->private_data, and there can't be any FS IO issued to > > this queue, and only private passthrough request will be handled, so > > force unfreezing queue into atomic mode. > > > > Signed-off-by: Ming Lei > > --- > > drivers/scsi/sd.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c > > index 0e73c3f2f381..27f04c860f00 100644 > > --- a/drivers/scsi/sd.c > > +++ b/drivers/scsi/sd.c > > @@ -3670,7 +3670,7 @@ static void scsi_disk_release(struct device *dev) > > * in case multiple processes open a /dev/sd... node concurrently. > > */ > > blk_mq_freeze_queue(q); > > - blk_mq_unfreeze_queue(q); > > + __blk_mq_unfreeze_queue(q, true); > > I think the right thing here is to drop the freeze/unfreeze pair. > Now that del_gendisk properly freezes the queue, we don't need this > protection as the issue that Bart fixed with it can't happen any more. As you see, the last patch removes freeze/unfreeze pair in del_gendisk(), which looks not very useful: it can't drain IO on bio based driver, and del_gendisk() is supposed to provide consistent behavior for both request and bio based driver. Thanks, Ming