From patchwork Thu May 21 06:43:03 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fam Zheng X-Patchwork-Id: 474829 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 D872114018C for ; Thu, 21 May 2015 16:53:16 +1000 (AEST) Received: from localhost ([::1]:55573 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YvKLz-0003GN-3u for incoming@patchwork.ozlabs.org; Thu, 21 May 2015 02:53:15 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37313) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YvKDU-0002rB-NG for qemu-devel@nongnu.org; Thu, 21 May 2015 02:44:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YvKDT-0004p9-Tl for qemu-devel@nongnu.org; Thu, 21 May 2015 02:44:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40138) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YvKDO-0004nw-Qf; Thu, 21 May 2015 02:44:22 -0400 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (Postfix) with ESMTPS id 6044CAB112; Thu, 21 May 2015 06:44:22 +0000 (UTC) Received: from ad.nay.redhat.com (dhcp-14-155.nay.redhat.com [10.66.14.155]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t4L6h4VJ007303; Thu, 21 May 2015 02:44:18 -0400 From: Fam Zheng To: qemu-devel@nongnu.org Date: Thu, 21 May 2015 14:43:03 +0800 Message-Id: <1432190583-10518-14-git-send-email-famz@redhat.com> In-Reply-To: <1432190583-10518-1-git-send-email-famz@redhat.com> References: <1432190583-10518-1-git-send-email-famz@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.27 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: Kevin Wolf , qemu-block@nongnu.org, jcody@redhat.com, armbru@redhat.com, mreitz@redhat.com, Stefan Hajnoczi , amit.shah@redhat.com, pbonzini@redhat.com Subject: [Qemu-devel] [PATCH v6 13/13] block/mirror: Block "device IO" during mirror exit 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 When mirror should complete, the source and target are in sync. But we call bdrv_swap() only a while later in the main loop bh. If the guest writes something before that, target will not get the new data. Block "device IO" before bdrv_drain and unblock it after bdrw_swap(). Reported-by: Wen Congyang Signed-off-by: Fam Zheng Reviewed-by: Max Reitz --- block/mirror.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/block/mirror.c b/block/mirror.c index 58f391a..ed770c2 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -320,6 +320,8 @@ static void mirror_drain(MirrorBlockJob *s) typedef struct { int ret; + /* Use to pause device IO during mirror exit */ + Error *blocker; } MirrorExitData; static void mirror_exit(BlockJob *job, void *opaque) @@ -358,6 +360,8 @@ static void mirror_exit(BlockJob *job, void *opaque) if (replace_aio_context) { aio_context_release(replace_aio_context); } + bdrv_op_unblock(s->common.bs, BLOCK_OP_TYPE_DEVICE_IO, data->blocker); + error_free(data->blocker); g_free(s->replaces); bdrv_unref(s->target); block_job_completed(&s->common, data->ret); @@ -376,6 +380,8 @@ static void coroutine_fn mirror_run(void *opaque) checking for a NULL string */ int ret = 0; int n; + data = g_malloc0(sizeof(*data)); + error_setg(&data->blocker, "mirror job exiting"); if (block_job_is_cancelled(&s->common)) { goto immediate_exit; @@ -521,6 +527,7 @@ static void coroutine_fn mirror_run(void *opaque) * mirror_populate runs. */ trace_mirror_before_drain(s, cnt); + bdrv_op_block(bs, BLOCK_OP_TYPE_DEVICE_IO, data->blocker); bdrv_drain(bs); cnt = bdrv_get_dirty_count(s->dirty_bitmap); } @@ -543,6 +550,7 @@ static void coroutine_fn mirror_run(void *opaque) s->common.cancelled = false; break; } + bdrv_op_unblock(bs, BLOCK_OP_TYPE_DEVICE_IO, data->blocker); last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); } @@ -563,7 +571,6 @@ immediate_exit: bdrv_release_dirty_bitmap(bs, s->dirty_bitmap); bdrv_iostatus_disable(s->target); - data = g_malloc(sizeof(*data)); data->ret = ret; block_job_defer_to_main_loop(&s->common, mirror_exit, data); }