From patchwork Thu Mar 28 16:40:31 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 232112 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 3DD862C00A9 for ; Fri, 29 Mar 2013 03:45:10 +1100 (EST) Received: from localhost ([::1]:37903 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ULFwq-0002WW-CM for incoming@patchwork.ozlabs.org; Thu, 28 Mar 2013 12:45:08 -0400 Received: from eggs.gnu.org ([208.118.235.92]:46633) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ULFtE-00065k-T4 for qemu-devel@nongnu.org; Thu, 28 Mar 2013 12:41:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ULFtB-0002Gq-US for qemu-devel@nongnu.org; Thu, 28 Mar 2013 12:41:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:62438) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ULFtB-0002Gj-Np for qemu-devel@nongnu.org; Thu, 28 Mar 2013 12:41:21 -0400 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r2SGfLLa025468 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 28 Mar 2013 12:41:21 -0400 Received: from localhost (ovpn-112-23.ams2.redhat.com [10.36.112.23]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r2SGfJWL019841; Thu, 28 Mar 2013 12:41:20 -0400 From: Stefan Hajnoczi To: Date: Thu, 28 Mar 2013 17:40:31 +0100 Message-Id: <1364488837-15916-18-git-send-email-stefanha@redhat.com> In-Reply-To: <1364488837-15916-1-git-send-email-stefanha@redhat.com> References: <1364488837-15916-1-git-send-email-stefanha@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.25 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: Kevin Wolf , Anthony Liguori , Stefan Hajnoczi Subject: [Qemu-devel] [PATCH 17/23] qcow2: handle_copied(): Implement non-zero host_offset X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Kevin Wolf Look only for clusters that start at a given physical offset. Signed-off-by: Kevin Wolf Signed-off-by: Stefan Hajnoczi --- block/qcow2-cluster.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 5e5465d..239a997 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -830,8 +830,6 @@ static int handle_dependencies(BlockDriverState *bs, uint64_t guest_offset, * the length of the area that can be written to. * * -errno: in error cases - * - * TODO Make non-zero host_offset behave like describe above */ static int handle_copied(BlockDriverState *bs, uint64_t guest_offset, uint64_t *host_offset, uint64_t *bytes, QCowL2Meta **m) @@ -846,7 +844,6 @@ static int handle_copied(BlockDriverState *bs, uint64_t guest_offset, trace_qcow2_handle_copied(qemu_coroutine_self(), guest_offset, *host_offset, *bytes); - assert(*host_offset == 0); /* * Calculate the number of clusters to look for. We stop at L2 table @@ -870,6 +867,16 @@ static int handle_copied(BlockDriverState *bs, uint64_t guest_offset, if (qcow2_get_cluster_type(cluster_offset) == QCOW2_CLUSTER_NORMAL && (cluster_offset & QCOW_OFLAG_COPIED)) { + /* If a specific host_offset is required, check it */ + bool offset_matches = + (cluster_offset & L2E_OFFSET_MASK) == *host_offset; + + if (*host_offset != 0 && !offset_matches) { + *bytes = 0; + ret = 0; + goto out; + } + /* We keep all QCOW_OFLAG_COPIED clusters */ keep_clusters = count_contiguous_clusters(nb_clusters, s->cluster_size, @@ -883,19 +890,22 @@ static int handle_copied(BlockDriverState *bs, uint64_t guest_offset, ret = 1; } else { - cluster_offset = 0; ret = 0; } - cluster_offset &= L2E_OFFSET_MASK; - *host_offset = cluster_offset; - /* Cleanup */ +out: pret = qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table); if (pret < 0) { return pret; } + /* Only return a host offset if we actually made progress. Otherwise we + * would make requirements for handle_alloc() that it can't fulfill */ + if (ret) { + *host_offset = cluster_offset & L2E_OFFSET_MASK; + } + return ret; } @@ -1165,7 +1175,6 @@ again: /* * 2. Count contiguous COPIED clusters. - * TODO: Consider cluster_offset if set in step 1c. */ uint64_t tmp_bytes = cur_bytes; ret = handle_copied(bs, offset, &cluster_offset, &tmp_bytes, m); @@ -1179,6 +1188,9 @@ again: if (!*host_offset) { *host_offset = cluster_offset; } + } else if (cur_bytes == 0) { + keep_clusters = 0; + goto done; } else { keep_clusters = 0; }