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 X-Spam-Level: X-Spam-Status: No, score=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 75AFDC43603 for ; Fri, 20 Dec 2019 10:29:39 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 4011E2072B for ; Fri, 20 Dec 2019 10:29:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="NciEBDwB" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4011E2072B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:52870 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iiFXO-0007PI-E1 for qemu-devel@archiver.kernel.org; Fri, 20 Dec 2019 05:29:38 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:54684) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iiFUt-0004lP-9B for qemu-devel@nongnu.org; Fri, 20 Dec 2019 05:27:04 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iiFUr-0007h6-QS for qemu-devel@nongnu.org; Fri, 20 Dec 2019 05:27:03 -0500 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:45213 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iiFUr-0007eR-JZ for qemu-devel@nongnu.org; Fri, 20 Dec 2019 05:27:01 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1576837621; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Q30peCWL/s5Pxkld0vifC6p0WAWiHMPQ+pVk5GZxywM=; b=NciEBDwBy1epnwe7Xwoo/5sO/u9vO/jgLfBqH+O8+IilN5TBRrTKPrq+lhf67vFxQWzoRA r9HZu1/jsfIjLq+/OKGH8kQSchDKC3xAMwvVDKPN75sgC7/ONol+0B4t0szzP6r2jKUMnE rf7cUh7bOFnIxI6yU+dhiAagdHioI6g= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-285-0xZ-_yUuMbOYaHYCreKrAQ-1; Fri, 20 Dec 2019 05:26:59 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B9ECA66F; Fri, 20 Dec 2019 10:26:58 +0000 (UTC) Received: from dhcp-200-226.str.redhat.com (dhcp-200-226.str.redhat.com [10.33.200.226]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D16B56B56E; Fri, 20 Dec 2019 10:26:57 +0000 (UTC) Date: Fri, 20 Dec 2019 11:26:56 +0100 From: Kevin Wolf To: Max Reitz Subject: Re: [PATCH 02/18] fuse: Allow exporting BDSs via FUSE Message-ID: <20191220102656.GD4019@dhcp-200-226.str.redhat.com> References: <20191219143818.1646168-1-mreitz@redhat.com> <20191219143818.1646168-3-mreitz@redhat.com> MIME-Version: 1.0 In-Reply-To: <20191219143818.1646168-3-mreitz@redhat.com> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-MC-Unique: 0xZ-_yUuMbOYaHYCreKrAQ-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.81 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qemu-devel@nongnu.org, qemu-block@nongnu.org, armbru@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Am 19.12.2019 um 15:38 hat Max Reitz geschrieben: > fuse-export-add allows mounting block graph nodes via FUSE on some > existing regular file. That file should then appears like a raw disk > image, and accesses to it result in accesses to the exported BDS. >=20 > Right now, we only set up the mount point and tear all mount points down > in bdrv_close_all(). We do not implement any access functions, so > accessing the mount point only results in errors. This will be > addressed by a followup patch. >=20 > The set of exported nodes is kept in a hash table so we can later add a > fuse-export-remove that allows unmounting. >=20 > Signed-off-by: Max Reitz > diff --git a/qapi/block.json b/qapi/block.json > index 145c268bb6..03f8d1b537 100644 > --- a/qapi/block.json > +++ b/qapi/block.json > @@ -317,6 +317,29 @@ > ## > { 'command': 'nbd-server-stop' } > =20 > +## > +# @fuse-export-add: > +# > +# Exports a block graph node on some (file) mountpoint as a raw image. > +# > +# @node-name: Node to be exported > +# > +# @mountpoint: Path on which to export the block device via FUSE. > +# This must point to an existing regular file. > +# > +# @writable: Whether clients should be able to write to the block > +# device via the FUSE export. (default: false) > +# > +# Since: 5.0 > +## > +{ 'command': 'fuse-export-add', > + 'data': { > + 'node-name': 'str', > + 'mountpoint': 'str', > + '*writable': 'bool' > + }, > + 'if': 'defined(CONFIG_FUSE)' } Can this use a BlockExport union from the start like I'm introducing in the storage daemon series, together with a generic block-export-add? It also looks like node-name and writable should be part of the common base of BlockExport. Unfortunately this would mean that I can't use the same BlockExportNbd for the existing nbd-server-add command any more. I guess I could somehow get a shared base type for both, though. Markus, any thoughts on these QAPI interfaces? Kevin