From patchwork Mon Apr 1 20:58:52 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Roth X-Patchwork-Id: 10880607 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5C2A414DE for ; Mon, 1 Apr 2019 21:16:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 44D2A28768 for ; Mon, 1 Apr 2019 21:16:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3934E2878E; Mon, 1 Apr 2019 21:16:58 +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=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id BFEC128768 for ; Mon, 1 Apr 2019 21:16:57 +0000 (UTC) Received: from localhost ([127.0.0.1]:41573 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hB4Ia-0008WC-CF for patchwork-qemu-devel@patchwork.kernel.org; Mon, 01 Apr 2019 17:16:56 -0400 Received: from eggs.gnu.org ([209.51.188.92]:40807) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hB44X-0001K0-3X for qemu-devel@nongnu.org; Mon, 01 Apr 2019 17:02:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hB44V-0003Nc-8d for qemu-devel@nongnu.org; Mon, 01 Apr 2019 17:02:25 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:52462) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hB44U-0003AO-Sa for qemu-devel@nongnu.org; Mon, 01 Apr 2019 17:02:23 -0400 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x31L1r12122331 for ; Mon, 1 Apr 2019 17:01:56 -0400 Received: from e33.co.us.ibm.com (e33.co.us.ibm.com [32.97.110.151]) by mx0a-001b2d01.pphosted.com with ESMTP id 2rksyg8phq-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 01 Apr 2019 17:01:55 -0400 Received: from localhost by e33.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Mon, 1 Apr 2019 22:01:44 +0100 Received: from b03ledav001.gho.boulder.ibm.com (b03ledav001.gho.boulder.ibm.com [9.17.130.232]) by b03cxnp08026.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x31L1hH052101172 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 1 Apr 2019 21:01:44 GMT Received: from b03ledav001.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C1E166E04E; Mon, 1 Apr 2019 21:01:42 +0000 (GMT) Received: from b03ledav001.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 920C26E066; Mon, 1 Apr 2019 21:01:42 +0000 (GMT) Received: from localhost (unknown [9.80.94.43]) by b03ledav001.gho.boulder.ibm.com (Postfix) with ESMTP; Mon, 1 Apr 2019 21:01:42 +0000 (GMT) From: Michael Roth To: qemu-devel@nongnu.org Date: Mon, 1 Apr 2019 15:58:52 -0500 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190401210011.16009-1-mdroth@linux.vnet.ibm.com> References: <20190401210011.16009-1-mdroth@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 19040121-0036-0000-0000-00000AA31DA2 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00010857; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000283; SDB=6.01182941; UDB=6.00619269; IPR=6.00963683; MB=3.00026249; MTD=3.00000008; XFM=3.00000015; UTC=2019-04-01 21:01:46 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19040121-0037-0000-0000-00004B3CB12D Message-Id: <20190401210011.16009-19-mdroth@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-04-01_06:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904010136 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] X-Received-From: 148.163.156.1 Subject: [Qemu-devel] [PATCH 18/97] mirror: Fail gracefully for source == target 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 , qemu-stable@nongnu.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Kevin Wolf blockdev-mirror with the same node for source and target segfaults today: A node is in its own backing chain, so mirror_start_job() decides that this is an active commit. When adding the intermediate nodes with block_job_add_bdrv(), it starts the iteration through the subchain with the backing file of source, though, so it never reaches target and instead runs into NULL at the base. While we could fix that by starting with source itself, there is no point in allowing mirroring a node into itself and I wouldn't be surprised if this caused more problems later. So just check for this scenario and error out. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf Reviewed-by: Eric Blake (cherry picked from commit 86fae10c64d642256cf019e6829929fa0d259c7a) Signed-off-by: Michael Roth --- block/mirror.c | 5 +++++ tests/qemu-iotests/041 | 6 ++++++ tests/qemu-iotests/041.out | 4 ++-- 3 files changed, 13 insertions(+), 2 deletions(-) diff --git a/block/mirror.c b/block/mirror.c index b48c3f8cf5..dd5ca02b09 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -1499,6 +1499,11 @@ static void mirror_start_job(const char *job_id, BlockDriverState *bs, buf_size = DEFAULT_MIRROR_BUF_SIZE; } + if (bs == target) { + error_setg(errp, "Can't mirror node into itself"); + return; + } + /* In the case of active commit, add dummy driver to provide consistent * reads on the top, while disabling it in the intermediate nodes, and make * the backing chain writable. */ diff --git a/tests/qemu-iotests/041 b/tests/qemu-iotests/041 index c20ac7da87..9336ab6ff5 100755 --- a/tests/qemu-iotests/041 +++ b/tests/qemu-iotests/041 @@ -234,6 +234,12 @@ class TestSingleBlockdev(TestSingleDrive): result = self.vm.qmp("blockdev-add", **args) self.assert_qmp(result, 'return', {}) + def test_mirror_to_self(self): + result = self.vm.qmp(self.qmp_cmd, job_id='job0', + device=self.qmp_target, sync='full', + target=self.qmp_target) + self.assert_qmp(result, 'error/class', 'GenericError') + test_large_cluster = None test_image_not_found = None test_small_buffer2 = None diff --git a/tests/qemu-iotests/041.out b/tests/qemu-iotests/041.out index c28b392b87..e071d0b261 100644 --- a/tests/qemu-iotests/041.out +++ b/tests/qemu-iotests/041.out @@ -1,5 +1,5 @@ -..................................................................................... +........................................................................................ ---------------------------------------------------------------------- -Ran 85 tests +Ran 88 tests OK