From nobody Wed Nov 5 10:30:43 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1499281576932968.0718542552729; Wed, 5 Jul 2017 12:06:16 -0700 (PDT) Received: from localhost ([::1]:47711 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dSpcq-0005J0-LC for importer@patchew.org; Wed, 05 Jul 2017 15:06:12 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40075) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dSpb5-00043k-6N for qemu-devel@nongnu.org; Wed, 05 Jul 2017 15:04:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dSpb4-0005wN-76 for qemu-devel@nongnu.org; Wed, 05 Jul 2017 15:04:23 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60726) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dSpaz-0005uM-Gd; Wed, 05 Jul 2017 15:04:17 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7D9EFC056791; Wed, 5 Jul 2017 19:04:16 +0000 (UTC) Received: from localhost (ovpn-204-111.brq.redhat.com [10.40.204.111]) by smtp.corp.redhat.com (Postfix) with ESMTPS id F01915D723; Wed, 5 Jul 2017 19:04:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 7D9EFC056791 Authentication-Results: ext-mx08.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx08.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=mreitz@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 7D9EFC056791 From: Max Reitz To: qemu-block@nongnu.org Date: Wed, 5 Jul 2017 21:04:02 +0200 Message-Id: <20170705190404.22449-4-mreitz@redhat.com> In-Reply-To: <20170705190404.22449-1-mreitz@redhat.com> References: <20170705190404.22449-1-mreitz@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Wed, 05 Jul 2017 19:04:16 +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 3/5] block: qobject_is_equal() in bdrv_reopen_prepare() 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 , Markus Armbruster , qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Currently, bdrv_reopen_prepare() assumes that all BDS options are strings. However, this is not the case if the BDS has been created through the json: pseudo-protocol or blockdev-add. Note that the user-invokable reopen command is an HMP command, so you can only specify strings there. Therefore, specifying a non-string option with the "same" value as it was when originally created will now return an error because the values are supposedly similar (and there is no way for the user to circumvent this but to just not specify the option again -- however, this is still strictly better than just crashing). Signed-off-by: Max Reitz Reviewed-by: Eric Blake --- block.c | 29 ++++++++++++++++++----------- 1 file changed, 18 insertions(+), 11 deletions(-) diff --git a/block.c b/block.c index 913bb43..f8c8e92 100644 --- a/block.c +++ b/block.c @@ -2947,19 +2947,26 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_sta= te, BlockReopenQueue *queue, const QDictEntry *entry =3D qdict_first(reopen_state->options); =20 do { - QString *new_obj =3D qobject_to_qstring(entry->value); - const char *new =3D qstring_get_str(new_obj); + QObject *new =3D entry->value; + QObject *old =3D qdict_get(reopen_state->bs->options, entry->k= ey); + /* - * Caution: while qdict_get_try_str() is fine, getting - * non-string types would require more care. When - * bs->options come from -blockdev or blockdev_add, its - * members are typed according to the QAPI schema, but - * when they come from -drive, they're all QString. + * TODO: When using -drive to specify blockdev options, all va= lues + * will be strings; however, when using -blockdev, blockdev-ad= d or + * filenames using the json:{} pseudo-protocol, they will be + * correctly typed. + * In contrast, reopening options are (currently) always strin= gs + * (because you can only specify them through qemu-io; all oth= er + * callers do not specify any options). + * Therefore, when using anything other than -drive to create = a BDS, + * this cannot detect non-string options as unchanged, because + * qobject_is_equal() always returns false for objects of diff= erent + * type. In the future, this should be remedied by correctly = typing + * all options. For now, this is not too big of an issue beca= use + * the user can simply omit options which cannot be changed an= yway, + * so they will stay unchanged. */ - const char *old =3D qdict_get_try_str(reopen_state->bs->option= s, - entry->key); - - if (!old || strcmp(new, old)) { + if (!qobject_is_equal(new, old)) { error_setg(errp, "Cannot change the option '%s'", entry->k= ey); ret =3D -EINVAL; goto error; --=20 2.9.4