From nobody Thu Dec 18 17:50:02 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; 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 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1559072497; cv=none; d=zoho.com; s=zohoarc; b=DhVnKz0g4BuCi7COmTyLuxJz8MaVx3dgv+J5PUV+622A/hubLR/p/Vu7hgmEILtwMnVoPJEAEREoFJi+9W6iImmM1zK2xZ7PQ5N2mh/4kq0gHf7yy9mnr0BgmrnXe2WipOVvDZ7kSe3jEA5VSLznPQu2Q/AgYv8sLKn7kTYepC4= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1559072497; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To:ARC-Authentication-Results; bh=lYOl6DM+S0I1mkZzYcYiiSjEp2QspraXpoabFr5HWkE=; b=bo7PRvIzLti7GQL3DuI8Y37ycIgsSI+1wHotLF7PVp1rZDcDR92UxX96UNnXCToYDeaLAgq2Ec29noVRzVRCtqufKojnCBFOy1qvZe47YdDn0XQkxvoxbKfePdJ7KF+gPC9jCP8uugnfw+vvo5qfOfZ7dGEzjQlk/wlSxrL5mrQ= ARC-Authentication-Results: i=1; mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1559072497915764.1325647172309; Tue, 28 May 2019 12:41:37 -0700 (PDT) Received: from localhost ([127.0.0.1]:41667 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hVhyO-0001bA-Kz for importer@patchew.org; Tue, 28 May 2019 15:41:24 -0400 Received: from eggs.gnu.org ([209.51.188.92]:36878) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hVhnj-0001LM-9R for qemu-devel@nongnu.org; Tue, 28 May 2019 15:30:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hVhnY-0001Vo-2S for qemu-devel@nongnu.org; Tue, 28 May 2019 15:30:19 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41084) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hVhnN-0000vt-5p; Tue, 28 May 2019 15:30:03 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E45A3883D7; Tue, 28 May 2019 19:29:34 +0000 (UTC) Received: from localhost (unknown [10.40.205.223]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 7844B60565; Tue, 28 May 2019 19:29:33 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Date: Tue, 28 May 2019 21:28:42 +0200 Message-Id: <20190528192847.2730-17-mreitz@redhat.com> In-Reply-To: <20190528192847.2730-1-mreitz@redhat.com> References: <20190528192847.2730-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Tue, 28 May 2019 19:29:34 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 16/21] qemu-img: rebase: Reuse parent BlockDriverState 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 , Peter Maydell , qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" From: Sam Eiderman In safe mode we open the entire chain, including the parent backing file of the rebased file. Do not open a new BlockBackend for the parent backing file, which saves opening the rest of the chain twice, which for long chains saves many "pricy" bdrv_open() calls. Permissions for blk_new() were copied from blk_new_open() when flags =3D 0. Reviewed-by: Karl Heubaum Reviewed-by: Eyal Moscovici Signed-off-by: Sagi Amit Co-developed-by: Sagi Amit Signed-off-by: Sam Eiderman Message-id: 20190523163337.4497-2-shmuel.eiderman@oracle.com Signed-off-by: Max Reitz --- qemu-img.c | 29 +++++++++-------------------- 1 file changed, 9 insertions(+), 20 deletions(-) diff --git a/qemu-img.c b/qemu-img.c index 28fba1e7a7..9bd0bb1e47 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -3309,29 +3309,18 @@ static int img_rebase(int argc, char **argv) =20 /* For safe rebasing we need to compare old and new backing file */ if (!unsafe) { - char backing_name[PATH_MAX]; QDict *options =3D NULL; + BlockDriverState *base_bs =3D backing_bs(bs); =20 - if (bs->backing) { - if (bs->backing_format[0] !=3D '\0') { - options =3D qdict_new(); - qdict_put_str(options, "driver", bs->backing_format); - } - - if (force_share) { - if (!options) { - options =3D qdict_new(); - } - qdict_put_bool(options, BDRV_OPT_FORCE_SHARE, true); - } - bdrv_get_backing_filename(bs, backing_name, sizeof(backing_nam= e)); - blk_old_backing =3D blk_new_open(backing_name, NULL, - options, src_flags, &local_err); - if (!blk_old_backing) { + if (base_bs) { + blk_old_backing =3D blk_new(BLK_PERM_CONSISTENT_READ, + BLK_PERM_ALL); + ret =3D blk_insert_bs(blk_old_backing, base_bs, + &local_err); + if (ret < 0) { error_reportf_err(local_err, - "Could not open old backing file '%s': ", - backing_name); - ret =3D -1; + "Could not reuse old backing file '%s': = ", + base_bs->filename); goto out; } } else { --=20 2.21.0