From patchwork Mon Nov 20 20:10:02 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 10067199 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 51F9F603FA for ; Mon, 20 Nov 2017 20:18:46 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 446B7292FA for ; Mon, 20 Nov 2017 20:18:46 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 394FF293CA; Mon, 20 Nov 2017 20:18:46 +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 B0D2F29326 for ; Mon, 20 Nov 2017 20:18:45 +0000 (UTC) Received: from localhost ([::1]:59534 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eGsWi-00069d-QF for patchwork-qemu-devel@patchwork.kernel.org; Mon, 20 Nov 2017 15:18:44 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35693) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eGsQE-00016p-AJ for qemu-devel@nongnu.org; Mon, 20 Nov 2017 15:12:03 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eGsQ9-0007pp-Qq for qemu-devel@nongnu.org; Mon, 20 Nov 2017 15:12:02 -0500 Received: from mx1.redhat.com ([209.132.183.28]:42200) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eGsQ6-0007oe-Sb; Mon, 20 Nov 2017 15:11:55 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1D7B13C92; Mon, 20 Nov 2017 20:11:54 +0000 (UTC) Received: from localhost (ovpn-204-75.brq.redhat.com [10.40.204.75]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9743160BE0; Mon, 20 Nov 2017 20:11:51 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Date: Mon, 20 Nov 2017 21:10:02 +0100 Message-Id: <20171120201004.14999-24-mreitz@redhat.com> In-Reply-To: <20171120201004.14999-1-mreitz@redhat.com> References: <20171120201004.14999-1-mreitz@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Mon, 20 Nov 2017 20:11:54 +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 v7 for-2.12 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 , John Snow , 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 Reviewed-by: Alberto Garcia --- block.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 75 insertions(+), 6 deletions(-) diff --git a/block.c b/block.c index 526ce43e9b..40007544e5 100644 --- a/block.c +++ b/block.c @@ -73,6 +73,9 @@ 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; @@ -2214,6 +2217,42 @@ 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 * @@ -2232,7 +2271,7 @@ 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; @@ -2262,11 +2301,6 @@ 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")) { /* keep 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; @@ -2287,6 +2321,8 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, goto free_exit; } + cloned_options = qdict_clone_shallow(options); + if (!reference && bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) { qdict_put_str(options, "driver", bs->backing_format); @@ -2302,6 +2338,10 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, } bdrv_set_aio_context(backing_hd, bdrv_get_aio_context(bs)); + 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, &local_err); @@ -2317,6 +2357,7 @@ 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; } @@ -4973,6 +5014,34 @@ 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().