From nobody Sat Feb 7 07:10:19 2026 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 1516463477215282.63742615276624; Sat, 20 Jan 2018 07:51:17 -0800 (PST) Received: from localhost ([::1]:46335 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ecvQK-0000xg-I1 for importer@patchew.org; Sat, 20 Jan 2018 10:51:16 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51623) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ecvJv-0004aO-5S for qemu-devel@nongnu.org; Sat, 20 Jan 2018 10:44:42 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ecvJr-0000C1-Ts for qemu-devel@nongnu.org; Sat, 20 Jan 2018 10:44:39 -0500 Received: from mx1.redhat.com ([209.132.183.28]:34394) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ecvJo-0008V8-AI; Sat, 20 Jan 2018 10:44:32 -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 6CC4E800AF; Sat, 20 Jan 2018 15:44:31 +0000 (UTC) Received: from localhost (ovpn-204-54.brq.redhat.com [10.40.204.54]) by smtp.corp.redhat.com (Postfix) with ESMTPS id F2E5660BE5; Sat, 20 Jan 2018 15:44:30 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Date: Sat, 20 Jan 2018 16:44:11 +0100 Message-Id: <20180120154412.9990-6-mreitz@redhat.com> In-Reply-To: <20180120154412.9990-1-mreitz@redhat.com> References: <20180120154412.9990-1-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 [10.5.110.28]); Sat, 20 Jan 2018 15:44:31 +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 v2 5/6] block: Handle null backing link 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 , 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" Instead of converting all "backing": null instances into "backing": "", handle a null value directly in bdrv_open_inherit(). This enables explicitly null backing links for json:{} filenames. Signed-off-by: Max Reitz Reviewed-by: Alberto Garcia --- block.c | 4 +++- blockdev.c | 14 -------------- tests/qemu-iotests/089 | 20 ++++++++++++++++++++ tests/qemu-iotests/089.out | 8 ++++++++ 4 files changed, 31 insertions(+), 15 deletions(-) diff --git a/block.c b/block.c index 909cf076b7..32b7887651 100644 --- a/block.c +++ b/block.c @@ -2597,7 +2597,9 @@ static BlockDriverState *bdrv_open_inherit(const char= *filename, =20 /* See cautionary note on accessing @options above */ backing =3D qdict_get_try_str(options, "backing"); - if (backing && *backing =3D=3D '\0') { + if (qobject_to(qdict_get(options, "backing"), QNull) !=3D NULL || + (backing && *backing =3D=3D '\0')) + { flags |=3D BDRV_O_NO_BACKING; qdict_del(options, "backing"); } diff --git a/blockdev.c b/blockdev.c index 2dce231c98..5aac920eae 100644 --- a/blockdev.c +++ b/blockdev.c @@ -3969,7 +3969,6 @@ void qmp_blockdev_add(BlockdevOptions *options, Error= **errp) QObject *obj; Visitor *v =3D qobject_output_visitor_new(&obj); QDict *qdict; - const QDictEntry *ent; Error *local_err =3D NULL; =20 visit_type_BlockdevOptions(v, NULL, &options, &local_err); @@ -3983,19 +3982,6 @@ void qmp_blockdev_add(BlockdevOptions *options, Erro= r **errp) =20 qdict_flatten(qdict); =20 - /* - * Rewrite "backing": null to "backing": "" - * TODO Rewrite "" to null instead, and perhaps not even here - */ - for (ent =3D qdict_first(qdict); ent; ent =3D qdict_next(qdict, ent)) { - char *dot =3D strrchr(ent->key, '.'); - - if (!strcmp(dot ? dot + 1 : ent->key, "backing") - && qobject_type(ent->value) =3D=3D QTYPE_QNULL) { - qdict_put(qdict, ent->key, qstring_new()); - } - } - if (!qdict_get_try_str(qdict, "node-name")) { error_setg(errp, "'node-name' must be specified for the root node"= ); goto fail; diff --git a/tests/qemu-iotests/089 b/tests/qemu-iotests/089 index 0b059aba90..aa1ba4a98e 100755 --- a/tests/qemu-iotests/089 +++ b/tests/qemu-iotests/089 @@ -82,6 +82,26 @@ $QEMU_IO_PROG --cache $CACHEMODE \ $QEMU_IO -c 'read -P 42 0 512' "$TEST_IMG" | _filter_qemu_io =20 =20 +echo +echo "=3D=3D=3D Testing correct handling of 'backing':null =3D=3D=3D" +echo + +_make_test_img -b "$TEST_IMG.base" $IMG_SIZE + +# This should read 42 +$QEMU_IO -c 'read -P 42 0 512' "$TEST_IMG" | _filter_qemu_io + +# This should read 0 +$QEMU_IO -c 'read -P 0 0 512' "json:{\ + 'driver': '$IMGFMT', + 'file': { + 'driver': 'file', + 'filename': '$TEST_IMG' + }, + 'backing': null +}" | _filter_qemu_io + + # Taken from test 071 echo echo "=3D=3D=3D Testing blkdebug =3D=3D=3D" diff --git a/tests/qemu-iotests/089.out b/tests/qemu-iotests/089.out index 0bf5a13ec1..89e3e4340a 100644 --- a/tests/qemu-iotests/089.out +++ b/tests/qemu-iotests/089.out @@ -19,6 +19,14 @@ Pattern verification failed at offset 0, 512 bytes read 512/512 bytes at offset 0 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) =20 +=3D=3D=3D Testing correct handling of 'backing':null =3D=3D=3D + +Formatting 'TEST_DIR/t.IMGFMT', fmt=3DIMGFMT size=3D67108864 backing_file= =3DTEST_DIR/t.IMGFMT.base +read 512/512 bytes at offset 0 +512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) +read 512/512 bytes at offset 0 +512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) + =3D=3D=3D Testing blkdebug =3D=3D=3D =20 Formatting 'TEST_DIR/t.IMGFMT', fmt=3DIMGFMT size=3D67108864 --=20 2.14.3