From patchwork Wed Nov 30 01:18:49 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 9453447 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 38AAD60235 for ; Wed, 30 Nov 2016 01:43:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2B7AC2818E for ; Wed, 30 Nov 2016 01:43:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1FC0028334; Wed, 30 Nov 2016 01:43:03 +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 8E8602818E for ; Wed, 30 Nov 2016 01:43:02 +0000 (UTC) Received: from localhost ([::1]:40268 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cBtvJ-00028Q-Hd for patchwork-qemu-devel@patchwork.kernel.org; Tue, 29 Nov 2016 20:43:01 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54856) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cBtYz-0008Ld-7G for qemu-devel@nongnu.org; Tue, 29 Nov 2016 20:19:58 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cBtYu-0006ae-CT for qemu-devel@nongnu.org; Tue, 29 Nov 2016 20:19:57 -0500 Received: from mx1.redhat.com ([209.132.183.28]:37310) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cBtYr-0006YO-Ok; Tue, 29 Nov 2016 20:19:49 -0500 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (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 002FF662C; Wed, 30 Nov 2016 01:19:49 +0000 (UTC) Received: from localhost (ovpn-116-36.phx2.redhat.com [10.3.116.36]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id uAU1JlfH020849 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Tue, 29 Nov 2016 20:19:48 -0500 From: Max Reitz To: qemu-block@nongnu.org Date: Wed, 30 Nov 2016 02:18:49 +0100 Message-Id: <20161130011851.24696-24-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 10.5.11.27 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Wed, 30 Nov 2016 01:19:49 +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 23/25] block: Fix FIXME from "Add BDS.backing_overridden" 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 Said commit introduced a FIXME stating that bdrv_open_backing_file() should set bs->backing_overridden to true not only if the file.filename option was set, but if the "options" QDict contained any option that is significant for any node in the BDS tree emerging from the backing BDS. This behavior is implemented by this patch. Signed-off-by: Max Reitz --- block.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 75 insertions(+), 6 deletions(-) diff --git a/block.c b/block.c index 71c14f4..62c5dc0 100644 --- a/block.c +++ b/block.c @@ -74,6 +74,9 @@ static BlockDriverState *bdrv_open_inherit(const char *filename, const BdrvChildRole *child_role, Error **errp); +static bool has_significant_runtime_options(BlockDriverState *bs, + const QDict *d); + /* If non-zero, use only whitelisted block drivers */ static int use_bdrv_whitelist; @@ -1481,6 +1484,42 @@ out: bdrv_refresh_limits(bs, NULL); } +/** + * Checks whether @options contains any significant option for any of the nodes + * in the BDS tree emerging from @bs. + */ +static bool is_significant_option_tree(BlockDriverState *bs, QDict *options) +{ + BdrvChild *child; + + if (!qdict_size(options)) { + /* No need to recurse */ + return false; + } + + if (has_significant_runtime_options(bs, options)) { + return true; + } + + QLIST_FOREACH(child, &bs->children, next) { + QDict *child_options; + char *option_prefix; + + option_prefix = g_strdup_printf("%s.", child->name); + qdict_extract_subqdict(options, &child_options, option_prefix); + g_free(option_prefix); + + if (is_significant_option_tree(child->bs, child_options)) { + QDECREF(child_options); + return true; + } + + QDECREF(child_options); + } + + return false; +} + /* * Opens the backing file for a BlockDriverState if not yet open * @@ -1499,7 +1538,7 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, const char *reference = NULL; int ret = 0; BlockDriverState *backing_hd; - QDict *options; + QDict *options, *cloned_options = NULL; QDict *tmp_parent_options = NULL; Error *local_err = NULL; @@ -1522,11 +1561,6 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, reference = qdict_get_try_str(parent_options, bdref_key); if (reference || qdict_haskey(options, "file.filename")) { backing_filename = NULL; - - /* FIXME: Should also be set to true if @options contains other runtime - * options which control the data that is read from the backing - * BDS */ - bs->backing_overridden = true; } else if (bs->backing_file[0] == '\0' && qdict_size(options) == 0) { QDECREF(options); goto free_exit; @@ -1547,6 +1581,8 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, goto free_exit; } + cloned_options = qdict_clone_shallow(options); + if (bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) { qdict_put(options, "driver", qstring_from_str(bs->backing_format)); } @@ -1560,6 +1596,10 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, goto free_exit; } + if (reference || is_significant_option_tree(backing_hd, cloned_options)) { + bs->backing_overridden = true; + } + /* Hook up the backing file link; drop our reference, bs owns the * backing_hd reference now */ bdrv_set_backing_hd(bs, backing_hd); @@ -1570,6 +1610,7 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, free_exit: g_free(backing_filename); QDECREF(tmp_parent_options); + QDECREF(cloned_options); return ret; } @@ -3964,6 +4005,34 @@ static const char *const *significant_options(BlockDriverState *bs, } /** + * Returns true if @d contains any options the block driver of @bs considers to + * be significant runtime options. + */ +static bool has_significant_runtime_options(BlockDriverState *bs, + const QDict *d) +{ + const char *const *option_name = NULL; + + while ((option_name = significant_options(bs, option_name))) { + assert(strlen(*option_name) > 0); + if ((*option_name)[strlen(*option_name) - 1] != '.') { + if (qdict_haskey(d, *option_name)) { + return true; + } + } else { + const QDictEntry *entry; + for (entry = qdict_first(d); entry; entry = qdict_next(d, entry)) { + if (strstart(qdict_entry_key(entry), *option_name, NULL)) { + return true; + } + } + } + } + + return false; +} + +/** * Copies all significant runtime options from bs->options to the given QDict. * The set of significant option keys is determined by invoking * significant_options().