From patchwork Thu Sep 6 09:37:05 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alberto Garcia X-Patchwork-Id: 966888 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=208.118.235.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=igalia.com Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=igalia.com header.i=@igalia.com header.b="FNcAS3Ld"; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 425bDb5h0pz9sD2 for ; Thu, 6 Sep 2018 19:41:19 +1000 (AEST) Received: from localhost ([::1]:60462 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fxqmr-0008MG-Ip for incoming@patchwork.ozlabs.org; Thu, 06 Sep 2018 05:41:17 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51966) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fxqjK-0005jE-Nb for qemu-devel@nongnu.org; Thu, 06 Sep 2018 05:37:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fxqjG-0003Yl-KA for qemu-devel@nongnu.org; Thu, 06 Sep 2018 05:37:38 -0400 Received: from fanzine.igalia.com ([91.117.99.155]:54015) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1fxqjG-0003QA-3P; Thu, 06 Sep 2018 05:37:34 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=References:In-Reply-To:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From; bh=V2jZt2dXjcOoqUefDzUVg/kfJEL0beDCNdf/Sin6CIQ=; b=FNcAS3LdIy5GcvZ8cmi6rh2H5g4ZWHtbN2IsD8l/2d2JXIxaMzoa30uQrKp7r6J9Zelsqn9Gyzm+cewNwk2+1q2ChYeFVLyaWZGAUKRr12Dfuuipc3ZdTpHZ1s+w3n2yu6rIQHbYnmeGWFXNCFT68XF3/dwyOxoTfEILPSYmymEeEb+kYDBCpNO+q/nm7AsW2HuI2FOLxqgwmREZJH6FFobhvaNvT0M3ifubnHyP5h7IZ4b1ezJT+8oKbUAN/2WuBaUUL28mp8Szu/9zTwjtxPi6T2XrtRKnvGzVE+sMEdATxvZP0/E9D1AWkXwT+zKHsn6sNV60GIXZK0gBGCppSg==; Received: from 91-158-71-53.elisa-laajakaista.fi ([91.158.71.53] helo=perseus.local) by fanzine.igalia.com with esmtpsa (Cipher TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim) id 1fxqjD-00049c-9J; Thu, 06 Sep 2018 11:37:31 +0200 Received: from berto by perseus.local with local (Exim 4.89) (envelope-from ) id 1fxqiy-0001o1-P8; Thu, 06 Sep 2018 12:37:16 +0300 From: Alberto Garcia To: qemu-devel@nongnu.org Date: Thu, 6 Sep 2018 12:37:05 +0300 Message-Id: <70c436dbf3914d952a2839bf8383a436dc5267ce.1536226505.git.berto@igalia.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: References: In-Reply-To: References: X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x (no timestamps) [generic] [fuzzy] X-Received-From: 91.117.99.155 Subject: [Qemu-devel] [PATCH v3 05/10] block: Allow child references on reopen 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-block@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" In the previous patches we removed all child references from bs->{options,explicit_options} because keeping them is useless and wrong. Because of this, any attempt to reopen a BlockDriverState using a child reference as one of its options would result in a failure, because bdrv_reopen_prepare() would detect that there's a new option (the child reference) that wasn't present in bs->options. But passing child references on reopen can be useful. It's a way to specify a BDS's child without having to pass recursively all of the child's options, and if the reference points to a different BDS then this can allow us to replace the child. However, replacing the child is something that needs to be implemented case by case and only when it makes sense. For now, this patch allows passing a child reference as long as it points to the current child of the BlockDriverState. It's also important to remember that, as a consequence of the previous patches, this child reference will be removed from bs->{options,explicit_options} after the reopening has been completed. Signed-off-by: Alberto Garcia Reviewed-by: Max Reitz --- block.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/block.c b/block.c index aaa4cf6897..5223d16f1b 100644 --- a/block.c +++ b/block.c @@ -3241,6 +3241,24 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue, QObject *new = entry->value; QObject *old = qdict_get(reopen_state->bs->options, entry->key); + /* Allow child references (child_name=node_name) as long as they + * point to the current child (i.e. everything stays the same). */ + if (qobject_type(new) == QTYPE_QSTRING) { + BdrvChild *child; + QLIST_FOREACH(child, &reopen_state->bs->children, next) { + if (!strcmp(child->name, entry->key)) { + break; + } + } + + if (child) { + const char *str = qobject_get_try_str(new); + if (!strcmp(child->bs->node_name, str)) { + continue; /* Found child with this name, skip option */ + } + } + } + /* * TODO: When using -drive to specify blockdev options, all values * will be strings; however, when using -blockdev, blockdev-add or