From patchwork Wed Nov 30 01:18:42 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 700818 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3tT3466G7Bz9t0t for ; Wed, 30 Nov 2016 12:39:18 +1100 (AEDT) Received: from localhost ([::1]:40242 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cBtrf-0007Xs-Pq for incoming@patchwork.ozlabs.org; Tue, 29 Nov 2016 20:39:15 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54562) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cBtYg-000834-3J for qemu-devel@nongnu.org; Tue, 29 Nov 2016 20:19:39 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cBtYf-0006ON-6X for qemu-devel@nongnu.org; Tue, 29 Nov 2016 20:19:38 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51056) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cBtYb-0006Lm-2e; Tue, 29 Nov 2016 20:19:33 -0500 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (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 39D1B8124A; Wed, 30 Nov 2016 01:19:32 +0000 (UTC) Received: from localhost (ovpn-116-36.phx2.redhat.com [10.3.116.36]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id uAU1JUgf010132 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Tue, 29 Nov 2016 20:19:31 -0500 From: Max Reitz To: qemu-block@nongnu.org Date: Wed, 30 Nov 2016 02:18:42 +0100 Message-Id: <20161130011851.24696-17-mreitz@redhat.com> In-Reply-To: <20161130011851.24696-1-mreitz@redhat.com> References: <20161130011851.24696-1-mreitz@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Wed, 30 Nov 2016 01:19:32 +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 v3 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" 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 --- block.c | 14 ++++++++++++++ include/block/block_int.h | 2 ++ qapi/block-core.json | 9 +++++++++ 3 files changed, 25 insertions(+) diff --git a/block.c b/block.c index 16eda37..d789caa 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; diff --git a/include/block/block_int.h b/include/block/block_int.h index 65d6f53..7143737 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/qapi/block-core.json b/qapi/block-core.json index c29bef7..a677483 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -2366,6 +2366,14 @@ # (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. # @@ -2374,6 +2382,7 @@ { 'union': 'BlockdevOptions', 'base': { 'driver': 'BlockdevDriver', '*node-name': 'str', + '*base-directory': 'str', '*discard': 'BlockdevDiscardOptions', '*cache': 'BlockdevCacheOptions', '*read-only': 'bool',