From patchwork Tue May 5 12:46:46 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fam Zheng X-Patchwork-Id: 468108 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 212E0140772 for ; Tue, 5 May 2015 22:47:59 +1000 (AEST) Received: from localhost ([::1]:39066 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YpcGS-0004MR-UT for incoming@patchwork.ozlabs.org; Tue, 05 May 2015 08:47:56 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45492) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YpcFh-0003Mo-2B for qemu-devel@nongnu.org; Tue, 05 May 2015 08:47:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YpcFb-0000RQ-GH for qemu-devel@nongnu.org; Tue, 05 May 2015 08:47:09 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40081) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YpcFY-0000Qb-1q; Tue, 05 May 2015 08:47:00 -0400 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (Postfix) with ESMTPS id A29C7AB103; Tue, 5 May 2015 12:46:59 +0000 (UTC) Received: from ad.nay.redhat.com (dhcp-14-137.nay.redhat.com [10.66.14.137]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t45Ckqnm008320; Tue, 5 May 2015 08:46:57 -0400 From: Fam Zheng To: qemu-devel@nongnu.org Date: Tue, 5 May 2015 20:46:46 +0800 Message-Id: <1430830009-29839-2-git-send-email-famz@redhat.com> In-Reply-To: <1430830009-29839-1-git-send-email-famz@redhat.com> References: <1430830009-29839-1-git-send-email-famz@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.26 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, Stefan Hajnoczi , pbonzini@redhat.com, jsnow@redhat.com, wangxiaolong@ucloud.cn Subject: [Qemu-devel] [PATCH 1/4] block: Fix dirty bitmap in bdrv_co_discard 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 Unsetting dirty globally with discard is not very correct. The discard may zero out sectors (depending on can_write_zeroes_with_unmap), we should replicate this change to destinition side to make sure that the guest sees the same data. Calling bdrv_reset_dirty also troubles mirror job because the hbitmap iterator doesn't expect unsetting of bits after current position. So let's do it the opposite way which fixes both problems: set the dirty bits if we are to discard it. Reported-by: wangxiaolong@ucloud.cn Signed-off-by: Fam Zheng --- block/io.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/block/io.c b/block/io.c index 1ce62c4..809688b 100644 --- a/block/io.c +++ b/block/io.c @@ -2343,8 +2343,6 @@ int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, return -EROFS; } - bdrv_reset_dirty(bs, sector_num, nb_sectors); - /* Do nothing if disabled. */ if (!(bs->open_flags & BDRV_O_UNMAP)) { return 0; @@ -2354,6 +2352,8 @@ int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, return 0; } + bdrv_set_dirty(bs, sector_num, nb_sectors); + max_discard = MIN_NON_ZERO(bs->bl.max_discard, BDRV_REQUEST_MAX_SECTORS); while (nb_sectors > 0) { int ret;