From patchwork Fri Nov 10 22:13:28 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 10053883 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 1F86960631 for ; Fri, 10 Nov 2017 22:18:05 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 135C52B496 for ; Fri, 10 Nov 2017 22:18:05 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 089AC2B49B; Fri, 10 Nov 2017 22:18:05 +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 87F8E2B49C for ; Fri, 10 Nov 2017 22:18:04 +0000 (UTC) Received: from localhost ([::1]:43679 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eDHch-0007dw-H7 for patchwork-qemu-devel@patchwork.kernel.org; Fri, 10 Nov 2017 17:18:03 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47483) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eDHYT-0004jZ-HO for qemu-devel@nongnu.org; Fri, 10 Nov 2017 17:13:42 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eDHYS-0005Z4-D8 for qemu-devel@nongnu.org; Fri, 10 Nov 2017 17:13:41 -0500 Received: from mx1.redhat.com ([209.132.183.28]:50636) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eDHYP-0005X0-Pa; Fri, 10 Nov 2017 17:13:37 -0500 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 0D46272FE9; Fri, 10 Nov 2017 22:13:37 +0000 (UTC) Received: from localhost (ovpn-204-126.brq.redhat.com [10.40.204.126]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 93FCD5D99A; Fri, 10 Nov 2017 22:13:36 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Date: Fri, 10 Nov 2017 23:13:28 +0100 Message-Id: <20171110221329.24176-3-mreitz@redhat.com> In-Reply-To: <20171110221329.24176-1-mreitz@redhat.com> References: <20171110221329.24176-1-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 [10.5.110.38]); Fri, 10 Nov 2017 22:13:37 +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 for-2.12 2/3] 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 , Markus Armbruster , 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 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: Eric Blake Reviewed-by: Alberto Garcia Reviewed-by: Markus Armbruster --- block.c | 2 +- blockdev.c | 14 -------------- tests/qemu-iotests/089 | 20 ++++++++++++++++++++ tests/qemu-iotests/089.out | 8 ++++++++ 4 files changed, 29 insertions(+), 15 deletions(-) diff --git a/block.c b/block.c index 85427df577..bc92ddd5a0 100644 --- a/block.c +++ b/block.c @@ -2558,7 +2558,7 @@ static BlockDriverState *bdrv_open_inherit(const char *filename, /* See cautionary note on accessing @options above */ backing = qdict_get_try_str(options, "backing"); - if (backing && *backing == '\0') { + if (qdict_is_qnull(options, "backing") || (backing && *backing == '\0')) { flags |= BDRV_O_NO_BACKING; qdict_del(options, "backing"); } diff --git a/blockdev.c b/blockdev.c index 56a6b24a0b..99ef618b39 100644 --- a/blockdev.c +++ b/blockdev.c @@ -3885,7 +3885,6 @@ void qmp_blockdev_add(BlockdevOptions *options, Error **errp) QObject *obj; Visitor *v = qobject_output_visitor_new(&obj); QDict *qdict; - const QDictEntry *ent; Error *local_err = NULL; visit_type_BlockdevOptions(v, NULL, &options, &local_err); @@ -3899,19 +3898,6 @@ void qmp_blockdev_add(BlockdevOptions *options, Error **errp) qdict_flatten(qdict); - /* - * Rewrite "backing": null to "backing": "" - * TODO Rewrite "" to null instead, and perhaps not even here - */ - for (ent = qdict_first(qdict); ent; ent = qdict_next(qdict, ent)) { - char *dot = strrchr(ent->key, '.'); - - if (!strcmp(dot ? dot + 1 : ent->key, "backing") - && qobject_type(ent->value) == 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 9bfe2307b3..832eac1248 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 +echo +echo "=== Testing correct handling of 'backing':null ===" +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 "=== Testing blkdebug ===" diff --git a/tests/qemu-iotests/089.out b/tests/qemu-iotests/089.out index 18f5fdda7a..607a9c6d9c 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) +=== Testing correct handling of 'backing':null === + +Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 backing_file=TEST_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) + === Testing blkdebug === Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864