Received: by 2002:a05:6a10:f347:0:0:0:0 with SMTP id d7csp5593580pxu;
        Tue, 22 Dec 2020 23:52:12 -0800 (PST)
X-Google-Smtp-Source: ABdhPJzc/eXb7c24XVfNBkUM+TDzYHD1OVwzKi48wFXP1vY1PEmde5BDjAMMG4hspJlCFWubVVah
X-Received: by 2002:a17:906:e291:: with SMTP id gg17mr23262661ejb.31.1608709932266;
        Tue, 22 Dec 2020 23:52:12 -0800 (PST)
ARC-Seal: i=1; a=rsa-sha256; t=1608709932; cv=none;
        d=google.com; s=arc-20160816;
        b=TaOynShXRxV3qDywAzw+XRkkwXFiWvPXJUVAD83ta3pMakoMevkczWTU/TbnxpENB7
         Rd0ap3wJYLn3JtwdXBSKaGyvom4lfLlzCwUENN0z4TlP09mzegjuiatlXbheOpO3P6RR
         4TyGwyyHWxPRoYGSGAXDTTl+WpDDFfPmJTVaGPhcqqKon+SgKdBtgWUSWIh5qLsbNYp2
         r4EzNpMHEdEfr+NF29XZhxBGOEJrLBzdjdHcV2thHyspQWGLHwNFr0LWjoEzGbdvhaWn
         pcsEzP3kS+xMEE1zsZ7vkASCFahXtubUQcGATfMv1y4ptCpuLzR8VCMmVCVeT93DknwR
         AvTw==
ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816;
        h=list-id:precedence:in-reply-to:content-disposition:mime-version
         :references:message-id:subject:cc:to:from:date:dkim-signature;
        bh=VJA2Gqy8jGT0RgzTT5UVlJfq4XprQm8NpWSKksAaoTw=;
        b=bgL4446OqUeGyL9jOtVXkCMdYDeVXCbdeI/fX89Kd+LeaE6hk0hCGr4evN4LwjpB5h
         zU4SaaCHig5ce2KMszl2rZVb/iKztxJ716+1HPP2DJCSHtJGk4XeHk0Kcc9qRNNDEdoj
         6B1puTKP21cmdb0cwd2qKHVtE5q6XfBZq4bP9xnYfA0hLxQn8RR78oL2eDpPrP8at1aN
         GeXQNNDvbk+VxHBF7z9gelt8v+aQAPxHJpWcGMrVqNn6cZMUCRDZe5/XDAheYEyojess
         i9qj68gDHRO6d9MqzI5MZem7bkfNOCSJ697/eb4wbY6m0IdPLr7mwnxjfvhq3o3IJ2jS
         RNOw==
ARC-Authentication-Results: i=1; mx.google.com;
       dkim=pass header.i=@infradead.org header.s=casper.20170209 header.b=Y2KK7HRk;
       spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18])
        by mx.google.com with ESMTP id l14si15931162edv.597.2020.12.22.23.51.50;
        Tue, 22 Dec 2020 23:52:12 -0800 (PST)
Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Authentication-Results: mx.google.com;
       dkim=pass header.i=@infradead.org header.s=casper.20170209 header.b=Y2KK7HRk;
       spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1727802AbgLWHtv (ORCPT <rfc822;ly15351151@gmail.com>
        + 99 others); Wed, 23 Dec 2020 02:49:51 -0500
Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58324 "EHLO
        lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1727179AbgLWHtv (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Wed, 23 Dec 2020 02:49:51 -0500
Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1])
        by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 126BDC0613D3;
        Tue, 22 Dec 2020 23:49:11 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed;
        d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version:
        References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To:
        Content-Transfer-Encoding:Content-ID:Content-Description;
        bh=VJA2Gqy8jGT0RgzTT5UVlJfq4XprQm8NpWSKksAaoTw=; b=Y2KK7HRkXqg1VLN9ubpTwYDI0w
        Ep+SKigC5jwe2uB1UnUMz3uOsrVasAiYXZUzP9QprSSBjPJVqSZvomAb9NqBq8/VzqcNEclwAUs/a
        9DpG7xDpanTsGh1QSz6ldIcRgzZwLujXZ+nZ/jcAJSf48gFxTkatMqAmJmc2aOcQMSVzk2xyxf/9+
        tGNvyc4LINYaZpwmksQKJ4Mnlp6k069qYALw9MkYmOSKZVWgpS4Mesca9CJVr2T0TaIpy6LcqkJTl
        9gjBt/ayYYok4M0W0gqXj+mKdlMVIPkSK6Ni3DTGAUivYygjDnO58CGjHXQgH7OiKrcppizSGoHq+
        xahlPh9g==;
Received: from hch by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux))
        id 1kryt8-00046B-Vc; Wed, 23 Dec 2020 07:48:52 +0000
Date:   Wed, 23 Dec 2020 07:48:50 +0000
From:   Christoph Hellwig <hch@infradead.org>
To:     Palmer Dabbelt <palmer@dabbelt.com>
Cc:     snitzer@redhat.com, Christoph Hellwig <hch@infradead.org>,
        josef@toxicpanda.com, bvanassche@acm.org, corbet@lwn.net,
        kernel-team@android.com, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org,
        song@kernel.org, dm-devel@redhat.com,
        linux-kselftest@vger.kernel.org, shuah@kernel.org, agk@redhat.com,
        michael.christie@oracle.com
Subject: Re: [PATCH v1 0/5] dm: dm-user: New target that proxies BIOs to
 userspace
Message-ID: <20201223074850.GA15369@infradead.org>
References: <20201222143616.GB12885@redhat.com>
 <mhng-26d96d8e-77aa-415b-a8ee-518a0e91b6ef@palmerdabbelt-glaptop>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <mhng-26d96d8e-77aa-415b-a8ee-518a0e91b6ef@palmerdabbelt-glaptop>
X-SRS-Rewrite: SMTP reverse-path rewritten from <hch@infradead.org> by casper.infradead.org. See http://www.infradead.org/rpr.html
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org


FYI, a few years ago I spent some time helping a customer to prepare
their block device in userspace using fuse code for upstreaming, but
at some point they abandoned the project.  But if for some reason we
don't want to use nbd I think a driver using the fuse infrastructure
would be the next logical choice.