From nobody Tue Nov 4 15:41:12 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 1503966276890256.8060782619124; Mon, 28 Aug 2017 17:24:36 -0700 (PDT) Received: from localhost ([::1]:41920 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dmUKY-0000BC-Fh for importer@patchew.org; Mon, 28 Aug 2017 20:24:34 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47528) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dmUCC-0000v0-IA for qemu-devel@nongnu.org; Mon, 28 Aug 2017 20:15:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dmUCA-0005Bf-ET for qemu-devel@nongnu.org; Mon, 28 Aug 2017 20:15:56 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:48696) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dmUCA-0005Af-3t for qemu-devel@nongnu.org; Mon, 28 Aug 2017 20:15:54 -0400 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v7T0E85d005466 for ; Mon, 28 Aug 2017 20:15:53 -0400 Received: from e12.ny.us.ibm.com (e12.ny.us.ibm.com [129.33.205.202]) by mx0a-001b2d01.pphosted.com with ESMTP id 2cmvjejk4c-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 28 Aug 2017 20:15:52 -0400 Received: from localhost by e12.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Mon, 28 Aug 2017 20:15:49 -0400 Received: from b01ledav001.gho.pok.ibm.com (b01ledav001.gho.pok.ibm.com [9.57.199.106]) by b01cxnp22033.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v7T0FmuQ24182974; Tue, 29 Aug 2017 00:15:48 GMT Received: from b01ledav001.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 025E92803E; Mon, 28 Aug 2017 20:15:42 -0400 (EDT) Received: from localhost (unknown [9.80.85.217]) by b01ledav001.gho.pok.ibm.com (Postfix) with ESMTP id BE47C2803F; Mon, 28 Aug 2017 20:15:41 -0400 (EDT) From: Michael Roth To: qemu-devel@nongnu.org Date: Mon, 28 Aug 2017 19:13:54 -0500 X-Mailer: git-send-email 2.7.4 In-Reply-To: <1503965694-10794-1-git-send-email-mdroth@linux.vnet.ibm.com> References: <1503965694-10794-1-git-send-email-mdroth@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17082900-0048-0000-0000-000001DAEA2F X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007630; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000226; SDB=6.00909028; UDB=6.00455849; IPR=6.00689279; BA=6.00005557; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00016909; XFM=3.00000015; UTC=2017-08-29 00:15:50 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17082900-0049-0000-0000-000042619399 Message-Id: <1503965694-10794-20-git-send-email-mdroth@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-08-28_13:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=1 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1708290001 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] [fuzzy] X-Received-From: 148.163.156.1 Subject: [Qemu-devel] [PATCH 19/79] block: Reuse bs as backing hd for drive-backup sync=none 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 , Fam Zheng , qemu-stable@nongnu.org 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" From: Fam Zheng Opening the backing image for the second time is bad, especially here when it is also in use as the active image as the source. The drive-backup job itself doesn't read from target->backing for COW, instead it gets data from the write notifier, so it's not a big problem. However, exporting the target to NBD etc. won't work, because of the likely stale metadata cache. Use BDRV_O_NO_BACKING in this case and manually set up the backing BdrvChild. Cc: qemu-stable@nongnu.org Signed-off-by: Fam Zheng Signed-off-by: Kevin Wolf (cherry picked from commit fc0932fdcfc3e5cafa3641e361b681c07f639812) Signed-off-by: Michael Roth --- blockdev.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/blockdev.c b/blockdev.c index e2f9c1e..841200e 100644 --- a/blockdev.c +++ b/blockdev.c @@ -3170,6 +3170,7 @@ static BlockJob *do_drive_backup(DriveBackup *backup,= BlockJobTxn *txn, Error *local_err =3D NULL; int flags; int64_t size; + bool set_backing_hd =3D false; =20 if (!backup->has_speed) { backup->speed =3D 0; @@ -3220,6 +3221,8 @@ static BlockJob *do_drive_backup(DriveBackup *backup,= BlockJobTxn *txn, } if (backup->sync =3D=3D MIRROR_SYNC_MODE_NONE) { source =3D bs; + flags |=3D BDRV_O_NO_BACKING; + set_backing_hd =3D true; } =20 size =3D bdrv_getlength(bs); @@ -3246,7 +3249,9 @@ static BlockJob *do_drive_backup(DriveBackup *backup,= BlockJobTxn *txn, } =20 if (backup->format) { - options =3D qdict_new(); + if (!options) { + options =3D qdict_new(); + } qdict_put_str(options, "driver", backup->format); } =20 @@ -3257,6 +3262,14 @@ static BlockJob *do_drive_backup(DriveBackup *backup= , BlockJobTxn *txn, =20 bdrv_set_aio_context(target_bs, aio_context); =20 + if (set_backing_hd) { + bdrv_set_backing_hd(target_bs, source, &local_err); + if (local_err) { + bdrv_unref(target_bs); + goto out; + } + } + if (backup->has_bitmap) { bmap =3D bdrv_find_dirty_bitmap(bs, backup->bitmap); if (!bmap) { --=20 2.7.4