From patchwork Fri Sep 25 15:50:54 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Cody X-Patchwork-Id: 522907 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 B0EC41400A0 for ; Sat, 26 Sep 2015 01:52:24 +1000 (AEST) Received: from localhost ([::1]:48139 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZfVIM-0004XP-FO for incoming@patchwork.ozlabs.org; Fri, 25 Sep 2015 11:52:22 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50226) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZfVHI-0002bx-W5 for qemu-devel@nongnu.org; Fri, 25 Sep 2015 11:51:22 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZfVHI-0002xr-39 for qemu-devel@nongnu.org; Fri, 25 Sep 2015 11:51:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58403) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZfVHC-0002wI-Oh; Fri, 25 Sep 2015 11:51:10 -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 6B753C0B2E0C; Fri, 25 Sep 2015 15:51:10 +0000 (UTC) Received: from localhost (ovpn-112-77.phx2.redhat.com [10.3.112.77]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t8PFp85T019344 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA256 bits=256 verify=NO); Fri, 25 Sep 2015 11:51:09 -0400 From: Jeff Cody To: qemu-block@nongnu.org Date: Fri, 25 Sep 2015 11:50:54 -0400 Message-Id: <1443196256-5601-6-git-send-email-jcody@redhat.com> In-Reply-To: <1443196256-5601-1-git-send-email-jcody@redhat.com> References: <1443196256-5601-1-git-send-email-jcody@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: peter.maydell@linaro.org, jcody@redhat.com, qemu-devel@nongnu.org Subject: [Qemu-devel] [PULL 5/7] Backup: don't do copy-on-read in before_write_notifier 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: Wen Congyang We will copy data in before_write_notifier to do backup. It is a nested I/O request, so we cannot do copy-on-read. The steps to reproduce it: 1. -drive copy-on-read=on,... // qemu option 2. drive_backup -f disk0 /path_to_backup.img // monitor command Signed-off-by: Wen Congyang Tested-by: Jeff Cody Message-id: 1441682913-14320-3-git-send-email-wency@cn.fujitsu.com Signed-off-by: Jeff Cody --- block/backup.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/block/backup.c b/block/backup.c index 965654d..5696431 100644 --- a/block/backup.c +++ b/block/backup.c @@ -89,7 +89,8 @@ static void cow_request_end(CowRequest *req) static int coroutine_fn backup_do_cow(BlockDriverState *bs, int64_t sector_num, int nb_sectors, - bool *error_is_read) + bool *error_is_read, + bool is_write_notifier) { BackupBlockJob *job = (BackupBlockJob *)bs->job; CowRequest cow_request; @@ -129,8 +130,14 @@ static int coroutine_fn backup_do_cow(BlockDriverState *bs, iov.iov_len = n * BDRV_SECTOR_SIZE; qemu_iovec_init_external(&bounce_qiov, &iov, 1); - ret = bdrv_co_readv(bs, start * BACKUP_SECTORS_PER_CLUSTER, n, - &bounce_qiov); + if (is_write_notifier) { + ret = bdrv_co_no_copy_on_readv(bs, + start * BACKUP_SECTORS_PER_CLUSTER, + n, &bounce_qiov); + } else { + ret = bdrv_co_readv(bs, start * BACKUP_SECTORS_PER_CLUSTER, n, + &bounce_qiov); + } if (ret < 0) { trace_backup_do_cow_read_fail(job, start, ret); if (error_is_read) { @@ -190,7 +197,7 @@ static int coroutine_fn backup_before_write_notify( assert((req->offset & (BDRV_SECTOR_SIZE - 1)) == 0); assert((req->bytes & (BDRV_SECTOR_SIZE - 1)) == 0); - return backup_do_cow(req->bs, sector_num, nb_sectors, NULL); + return backup_do_cow(req->bs, sector_num, nb_sectors, NULL, true); } static void backup_set_speed(BlockJob *job, int64_t speed, Error **errp) @@ -303,7 +310,8 @@ static int coroutine_fn backup_run_incremental(BackupBlockJob *job) return ret; } ret = backup_do_cow(bs, cluster * BACKUP_SECTORS_PER_CLUSTER, - BACKUP_SECTORS_PER_CLUSTER, &error_is_read); + BACKUP_SECTORS_PER_CLUSTER, &error_is_read, + false); if ((ret < 0) && backup_error_action(job, error_is_read, -ret) == BLOCK_ERROR_ACTION_REPORT) { @@ -408,7 +416,7 @@ static void coroutine_fn backup_run(void *opaque) } /* FULL sync mode we copy the whole drive. */ ret = backup_do_cow(bs, start * BACKUP_SECTORS_PER_CLUSTER, - BACKUP_SECTORS_PER_CLUSTER, &error_is_read); + BACKUP_SECTORS_PER_CLUSTER, &error_is_read, false); if (ret < 0) { /* Depending on error action, fail now or retry cluster */ BlockErrorAction action =