From patchwork Mon Jan 16 20:49:12 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 9519427 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 5516D601C3 for ; Mon, 16 Jan 2017 20:50:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 467662823E for ; Mon, 16 Jan 2017 20:50:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3B2E2282DC; Mon, 16 Jan 2017 20:50:28 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id C12DB28285 for ; Mon, 16 Jan 2017 20:50:27 +0000 (UTC) Received: from localhost ([::1]:59453 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cTEEU-00012R-Nz for patchwork-qemu-devel@patchwork.kernel.org; Mon, 16 Jan 2017 15:50:26 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45732) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cTEDs-0000zY-KH for qemu-devel@nongnu.org; Mon, 16 Jan 2017 15:49:49 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cTEDr-0003r8-OE for qemu-devel@nongnu.org; Mon, 16 Jan 2017 15:49:48 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51188) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cTEDo-0003pK-J7; Mon, 16 Jan 2017 15:49:44 -0500 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A67423B470; Mon, 16 Jan 2017 20:49:44 +0000 (UTC) Received: from localhost (ovpn-204-161.brq.redhat.com [10.40.204.161]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v0GKng1E010469 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Mon, 16 Jan 2017 15:49:44 -0500 From: Max Reitz To: qemu-block@nongnu.org Date: Mon, 16 Jan 2017 21:49:12 +0100 Message-Id: <20170116204921.31578-9-mreitz@redhat.com> In-Reply-To: <20170111181432.18868-1-mreitz@redhat.com> References: <20170111181432.18868-1-mreitz@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.26 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Mon, 16 Jan 2017 20:49:44 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v4 16/25] block: Add 'base-directory' BDS option 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: Kevin Wolf , Alberto Garcia , qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP Using this option, one can directly override what bdrv_dirname() will return. This is useful if one uses e.g. qcow2 on top of quorum (with only protocol BDSs under the quorum BDS) and wants to be able to use relative backing filenames. Signed-off-by: Max Reitz --- qapi/block-core.json | 9 +++++++++ include/block/block_int.h | 2 ++ block.c | 14 ++++++++++++++ 3 files changed, 25 insertions(+) diff --git a/qapi/block-core.json b/qapi/block-core.json index 6b42216960..b4bd941696 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -2367,6 +2367,14 @@ # (default: false) # @detect-zeroes: #optional detect and optimize zero writes (Since 2.1) # (default: off) +# @base-directory #optional May be specified for any node. Normally, whenever a +# filename is specified which is supposed to be relative to this +# node (such as relative backing filenames), the base directory +# to be used is the directory the image file of this node is in, +# which is simply prepended to the relative filename. Using this +# option, the string which is prepended (i.e. the base +# directory) can be overridden. +# (Since 2.9) # # Remaining options are determined by the block driver. # @@ -2375,6 +2383,7 @@ { 'union': 'BlockdevOptions', 'base': { 'driver': 'BlockdevDriver', '*node-name': 'str', + '*base-directory': 'str', '*discard': 'BlockdevDiscardOptions', '*cache': 'BlockdevCacheOptions', '*read-only': 'bool', diff --git a/include/block/block_int.h b/include/block/block_int.h index fb916a7890..30fc1def4a 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -467,6 +467,8 @@ struct BlockDriverState { QDict *full_open_options; char exact_filename[PATH_MAX]; + char *dirname; + BdrvChild *backing; BdrvChild *file; diff --git a/block.c b/block.c index f3d4436c9e..a10ba111bc 100644 --- a/block.c +++ b/block.c @@ -984,6 +984,12 @@ QemuOptsList bdrv_runtime_opts = { .type = QEMU_OPT_STRING, .help = "discard operation (ignore/off, unmap/on)", }, + { + .name = "base-directory", + .type = QEMU_OPT_STRING, + .help = "String to prepend to filenames relative to this BDS for " + "making them absolute", + }, { /* end of list */ } }, }; @@ -1047,6 +1053,8 @@ static int bdrv_open_common(BlockDriverState *bs, BdrvChild *file, goto fail_opts; } + bs->dirname = g_strdup(qemu_opt_get(opts, "base-directory")); + bs->read_only = !(bs->open_flags & BDRV_O_RDWR); if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, bs->read_only)) { @@ -2490,6 +2498,8 @@ static void bdrv_delete(BlockDriverState *bs) bdrv_close(bs); + g_free(bs->dirname); + /* remove from list, if necessary */ if (bs->node_name[0] != '\0') { QTAILQ_REMOVE(&graph_bdrv_states, bs, node_list); @@ -4097,6 +4107,10 @@ char *bdrv_dirname(BlockDriverState *bs, Error **errp) { BlockDriver *drv = bs->drv; + if (bs->dirname) { + return g_strdup(bs->dirname); + } + if (!drv) { error_setg(errp, "Node '%s' is ejected", bs->node_name); return NULL;