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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D80FEC433EF for ; Mon, 24 Jan 2022 15:14:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240709AbiAXPOk (ORCPT ); Mon, 24 Jan 2022 10:14:40 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:56618 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240722AbiAXPOi (ORCPT ); Mon, 24 Jan 2022 10:14:38 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1643037277; 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=dk5kGxRxi565EfcpOZ1yuslQdkFqELh0PiM92UCiGmo=; b=I1ufN6GFfpbntpWSV8KZWDpx3RLgPdX8bFDescGMhpRkIfwOTRV5i2pKsJ2KqM4bC37YqZ KXdJHxKXZkJboDM2Bi2Zq5IOq+iIurup1dL0SMTLO/YI12rxWBdoGNotgyDUBWix9CYdIq BsLpmQNL/0tEp7pt/SQMbKcpU30zROo= 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-474-1jTLhPTUMECjJhSHFDmUAA-1; Mon, 24 Jan 2022 10:14:33 -0500 X-MC-Unique: 1jTLhPTUMECjJhSHFDmUAA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0916D8519E0; Mon, 24 Jan 2022 15:14:33 +0000 (UTC) Received: from agk-cloud1.hosts.prod.upshift.rdu2.redhat.com (agk-cloud1.hosts.prod.upshift.rdu2.redhat.com [10.0.13.154]) by smtp.corp.redhat.com (Postfix) with ESMTP id E2B7E7E2F4; Mon, 24 Jan 2022 15:14:32 +0000 (UTC) Received: by agk-cloud1.hosts.prod.upshift.rdu2.redhat.com (Postfix, from userid 3883) id 1EDD0424F088; Mon, 24 Jan 2022 15:14:34 +0000 (GMT) Date: Mon, 24 Jan 2022 15:14:34 +0000 From: Alasdair G Kergon To: Brian Geffon Cc: Alasdair Kergon , Mike Snitzer , dm-devel@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] dm: introduce a no open flag for deferred remove Message-ID: <20220124151434.GB20331@agk-cloud1.hosts.prod.upshift.rdu2.redhat.com> Mail-Followup-To: Brian Geffon , Alasdair Kergon , Mike Snitzer , dm-devel@redhat.com, linux-kernel@vger.kernel.org References: <20220124150209.22202-1-bgeffon@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220124150209.22202-1-bgeffon@google.com> Organization: Red Hat UK Ltd. Registered in England and Wales, number 03798903. Registered Office: Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE. User-Agent: Mutt/1.5.21 (2010-09-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 24, 2022 at 07:02:09AM -0800, Brian Geffon wrote: > When a device is being removed with deferred remove it's > still possible to open and use the device. This change > introduces a flag called DM_DEFERRED_REMOVE_NO_OPEN_FLAG > which when used with DM_DEFERRED_REMOVE will cause any > new opens to fail with -ENXIO. What is the need for this? Does it break any semantics assumed by userspace? Alasdair