From patchwork Mon Apr 8 14:35:43 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 10889679 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9E4671669 for ; Mon, 8 Apr 2019 14:41:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 88C212843B for ; Mon, 8 Apr 2019 14:41:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7D3CF28632; Mon, 8 Apr 2019 14:41:28 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 2D38C2843B for ; Mon, 8 Apr 2019 14:41:28 +0000 (UTC) Received: from localhost ([127.0.0.1]:54092 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hDVSh-000262-Ie for patchwork-qemu-devel@patchwork.kernel.org; Mon, 08 Apr 2019 10:41:27 -0400 Received: from eggs.gnu.org ([209.51.188.92]:55447) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hDVO2-0007MD-AD for qemu-devel@nongnu.org; Mon, 08 Apr 2019 10:36:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hDVO1-0000VV-9W for qemu-devel@nongnu.org; Mon, 08 Apr 2019 10:36:38 -0400 Received: from mx1.redhat.com ([209.132.183.28]:49078) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hDVNu-0000Q9-Du; Mon, 08 Apr 2019 10:36:32 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1F859859FB; Mon, 8 Apr 2019 14:36:29 +0000 (UTC) Received: from linux.fritz.box.com (ovpn-117-165.ams2.redhat.com [10.36.117.165]) by smtp.corp.redhat.com (Postfix) with ESMTP id AE2F717DD4; Mon, 8 Apr 2019 14:36:27 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Date: Mon, 8 Apr 2019 16:35:43 +0200 Message-Id: <20190408143543.3982-5-kwolf@redhat.com> In-Reply-To: <20190408143543.3982-1-kwolf@redhat.com> References: <20190408143543.3982-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Mon, 08 Apr 2019 14:36:29 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH 4/4] file-posix: Add dynamic-auto-read-only QAPI feature X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, pkrempa@redhat.com, armbru@redhat.com, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP In commit 23dece19da4 ('file-posix: Make auto-read-only dynamic') , auto-read-only=on changed its behaviour in file-posix for the 4.0 release. This change cannot be detected through the usual mechanisms like schema introspection. Add a new feature flag to the schema to allow libvirt to detect the presence of the new behaviour. Signed-off-by: Kevin Wolf --- qapi/block-core.json | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/qapi/block-core.json b/qapi/block-core.json index 7ccbfff9d0..4f96d5846b 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -2843,6 +2843,13 @@ # file is large, do not use in production. # (default: off) (since: 3.0) # +# If the feature 'dynamic-auto-read-only' is present, enabled auto-read-only +# means that the driver will open the image read-only at first, dynamically +# reopen the image file read-write when the first writer is attached to the +# node and reopen read-only when the last writer is detached. This allows to +# give QEMU write permissions only on demand when an operation actually needs +# write access. +# # Since: 2.9 ## { 'struct': 'BlockdevOptionsFile', @@ -2852,7 +2859,9 @@ '*aio': 'BlockdevAioOptions', '*drop-cache': {'type': 'bool', 'if': 'defined(CONFIG_LINUX)'}, - '*x-check-cache-dropped': 'bool' } } + '*x-check-cache-dropped': 'bool' }, + 'features': [ { 'name': 'dynamic-auto-read-only', + 'if': 'defined(CONFIG_POSIX)' } ] } ## # @BlockdevOptionsNull: