From patchwork Thu Oct 1 04:31:48 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Cody X-Patchwork-Id: 524956 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 6FCBE140D6D for ; Thu, 1 Oct 2015 21:52:34 +1000 (AEST) Received: from localhost ([::1]:48832 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZhcPY-0004Rq-99 for incoming@patchwork.ozlabs.org; Thu, 01 Oct 2015 07:52:32 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59181) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZhVXD-0000M7-CW for qemu-devel@nongnu.org; Thu, 01 Oct 2015 00:32:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZhVXC-00063v-CC for qemu-devel@nongnu.org; Thu, 01 Oct 2015 00:31:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36833) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZhVX6-00063D-1b; Thu, 01 Oct 2015 00:31:52 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (Postfix) with ESMTPS id 1B334558DE; Thu, 1 Oct 2015 04:31:51 +0000 (UTC) Received: from localhost (ovpn-112-77.phx2.redhat.com [10.3.112.77]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t914VmiS020814 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA256 bits=256 verify=NO); Thu, 1 Oct 2015 00:31:50 -0400 From: Jeff Cody To: qemu-devel@nongnu.org Date: Thu, 1 Oct 2015 00:31:48 -0400 Message-Id: <0c2c486b3692736e0b7084f1bc2461ab362ac98b.1443673739.git.jcody@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: kwolf@redhat.com, qemu-block@nongnu.org, mreitz@redhat.com, stefanha@redhat.com, pbonzini@redhat.com Subject: [Qemu-devel] [PATCH v2] block: mirror - fix full sync mode when target does not support zero init 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 During mirror, if the target device does not support zero init, a mirror may result in a corrupted image for sync="full" mode. This is due to how the initial dirty bitmap is set up prior to copying data - we did not mark sectors as dirty that are unallocated. This means those unallocated sectors are skipped over on the target, and for a device without zero init, invalid data may reside in those holes. If both of the following conditions are true, then we will explicitly mark all sectors as dirty: 1.) sync = "full" 2.) bdrv_has_zero_init(target) == false If the target does support zero init, but a target image is passed in with data already present (i.e. an "existing" image), it is assumed the data present in the existing image is valid data for those sectors. Signed-off-by: Jeff Cody --- block/mirror.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/block/mirror.c b/block/mirror.c index a258926..5d7828b 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -61,6 +61,7 @@ typedef struct MirrorBlockJob { int ret; bool unmap; bool waiting_for_io; + bool mark_all_dirty; } MirrorBlockJob; typedef struct MirrorOp { @@ -477,7 +478,7 @@ static void coroutine_fn mirror_run(void *opaque) } assert(n > 0); - if (ret == 1) { + if (ret == 1 || s->mark_all_dirty) { bdrv_set_dirty_bitmap(s->dirty_bitmap, sector_num, n); } sector_num += n; @@ -688,7 +689,7 @@ static void mirror_start_job(BlockDriverState *bs, BlockDriverState *target, int64_t buf_size, BlockdevOnError on_source_error, BlockdevOnError on_target_error, - bool unmap, + bool unmap, bool mark_all_dirty, BlockCompletionFunc *cb, void *opaque, Error **errp, const BlockJobDriver *driver, @@ -732,6 +733,7 @@ static void mirror_start_job(BlockDriverState *bs, BlockDriverState *target, s->granularity = granularity; s->buf_size = ROUND_UP(buf_size, granularity); s->unmap = unmap; + s->mark_all_dirty = mark_all_dirty; s->dirty_bitmap = bdrv_create_dirty_bitmap(bs, granularity, NULL, errp); if (!s->dirty_bitmap) { @@ -757,6 +759,7 @@ void mirror_start(BlockDriverState *bs, BlockDriverState *target, void *opaque, Error **errp) { bool is_none_mode; + bool mark_all_dirty; BlockDriverState *base; if (mode == MIRROR_SYNC_MODE_INCREMENTAL) { @@ -764,11 +767,13 @@ void mirror_start(BlockDriverState *bs, BlockDriverState *target, return; } is_none_mode = mode == MIRROR_SYNC_MODE_NONE; + mark_all_dirty = mode == MIRROR_SYNC_MODE_FULL && + !bdrv_has_zero_init(target); base = mode == MIRROR_SYNC_MODE_TOP ? bs->backing_hd : NULL; mirror_start_job(bs, target, replaces, speed, granularity, buf_size, - on_source_error, on_target_error, unmap, cb, opaque, errp, - &mirror_job_driver, is_none_mode, base); + on_source_error, on_target_error, unmap, mark_all_dirty, + cb, opaque, errp, &mirror_job_driver, is_none_mode, base); } void commit_active_start(BlockDriverState *bs, BlockDriverState *base, @@ -815,7 +820,7 @@ void commit_active_start(BlockDriverState *bs, BlockDriverState *base, bdrv_ref(base); mirror_start_job(bs, base, NULL, speed, 0, 0, - on_error, on_error, false, cb, opaque, &local_err, + on_error, on_error, false, false, cb, opaque, &local_err, &commit_active_job_driver, false, base); if (local_err) { error_propagate(errp, local_err);