From patchwork Tue Apr 11 01:17:11 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Blake X-Patchwork-Id: 9674443 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 979666020C for ; Tue, 11 Apr 2017 01:22:52 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8546B2846F for ; Tue, 11 Apr 2017 01:22:52 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 76D68284DD; Tue, 11 Apr 2017 01:22:52 +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 161672846F for ; Tue, 11 Apr 2017 01:22:52 +0000 (UTC) Received: from localhost ([::1]:36707 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cxkWB-00009D-6d for patchwork-qemu-devel@patchwork.kernel.org; Mon, 10 Apr 2017 21:22:51 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46417) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cxkR6-0005HK-Af for qemu-devel@nongnu.org; Mon, 10 Apr 2017 21:17:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cxkR5-0005qM-4X for qemu-devel@nongnu.org; Mon, 10 Apr 2017 21:17:36 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40230) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cxkR2-0005oe-LO; Mon, 10 Apr 2017 21:17:32 -0400 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 A9D6A4AEA3; Tue, 11 Apr 2017 01:17:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com A9D6A4AEA3 Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=eblake@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com A9D6A4AEA3 Received: from red.redhat.com (ovpn-122-58.rdu2.redhat.com [10.10.122.58]) by smtp.corp.redhat.com (Postfix) with ESMTP id EE47278DF2; Tue, 11 Apr 2017 01:17:30 +0000 (UTC) From: Eric Blake To: qemu-devel@nongnu.org Date: Mon, 10 Apr 2017 20:17:11 -0500 Message-Id: <20170411011718.9152-7-eblake@redhat.com> In-Reply-To: <20170411011718.9152-1-eblake@redhat.com> References: <20170411011718.9152-1-eblake@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 [10.5.110.39]); Tue, 11 Apr 2017 01:17:31 +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 v9 06/13] qcow2: Assert that cluster operations are aligned 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: kwolf@redhat.com, qemu-block@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP We already audited (in commit 0c1bd469) that qcow2_discard_clusters() is only passed cluster-aligned start values; but we can further tighten the assertion that the only unaligned end value is at EOF. Recent commits have taken advantage of an unaligned tail cluster, for both discard and write zeroes. Signed-off-by: Eric Blake --- v9: rebase to master, by asserting that only tail cluster is unaligned v7, v8: only earlier half of series submitted for 2.9 v6: avoid assertion on non-cluster-aligned image, use s->cluster_sectors to avoid a shift, drop R-b v5: no change v4: new patch --- block/qcow2-cluster.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 12f44b2..362a855 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -1519,11 +1519,10 @@ int qcow2_discard_clusters(BlockDriverState *bs, uint64_t offset, end_offset = offset + (nb_sectors << BDRV_SECTOR_BITS); - /* The caller must cluster-align start; round end down except at EOF */ + /* Caller must pass aligned values, except at image end */ assert(QEMU_IS_ALIGNED(offset, s->cluster_size)); - if (end_offset != bs->total_sectors * BDRV_SECTOR_SIZE) { - end_offset = start_of_cluster(s, end_offset); - } + assert(QEMU_IS_ALIGNED(end_offset, s->cluster_size) || + end_offset == bs->total_sectors << BDRV_SECTOR_BITS); nb_clusters = size_to_clusters(s, end_offset - offset); @@ -1596,9 +1595,17 @@ int qcow2_zero_clusters(BlockDriverState *bs, uint64_t offset, int nb_sectors, int flags) { BDRVQcow2State *s = bs->opaque; + uint64_t end_offset; uint64_t nb_clusters; int ret; + end_offset = offset + (nb_sectors << BDRV_SECTOR_BITS); + + /* Caller must pass aligned values, except at image end */ + assert(QEMU_IS_ALIGNED(offset, s->cluster_size)); + assert(QEMU_IS_ALIGNED(end_offset, s->cluster_size) || + end_offset == bs->total_sectors << BDRV_SECTOR_BITS); + /* The zero flag is only supported by version 3 and newer; we * require the use of that flag if there is a backing file or if * we are not allowed to unmap. */