From patchwork Fri May 22 03:40:56 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fam Zheng X-Patchwork-Id: 475276 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 6ABB714029C for ; Fri, 22 May 2015 13:42:13 +1000 (AEST) Received: from localhost ([::1]:60176 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Yvdqd-0001V8-KR for incoming@patchwork.ozlabs.org; Thu, 21 May 2015 23:42:11 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54744) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Yvdq2-0000Bn-Ba for qemu-devel@nongnu.org; Thu, 21 May 2015 23:41:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Yvdq0-0000OG-Sm for qemu-devel@nongnu.org; Thu, 21 May 2015 23:41:34 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34213) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Yvdq0-0000Nt-ME; Thu, 21 May 2015 23:41:32 -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 (8.14.4/8.14.4) with ESMTP id t4M3fVvw005933 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 21 May 2015 23:41:32 -0400 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 t4M3f1wv012352; Thu, 21 May 2015 23:41:26 -0400 From: Fam Zheng To: qemu-devel@nongnu.org Date: Fri, 22 May 2015 11:40:56 +0800 Message-Id: <1432266060-22104-5-git-send-email-famz@redhat.com> In-Reply-To: <1432266060-22104-1-git-send-email-famz@redhat.com> References: <1432266060-22104-1-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, Jeff Cody , qemu-stable@nongnu.org, Stefan Hajnoczi , pbonzini@redhat.com, jsnow@redhat.com, wangxiaolong@ucloud.cn Subject: [Qemu-devel] [PATCH v4 4/8] 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 Reviewed-by: Paolo Bonzini Reviewed-by: Eric Blake --- block/io.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/block/io.c b/block/io.c index 36a4007..a1ff943 100644 --- a/block/io.c +++ b/block/io.c @@ -2368,8 +2368,6 @@ 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; @@ -2379,6 +2377,8 @@ 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;