From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52565) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z1wqr-0001Tg-5y for qemu-devel@nongnu.org; Mon, 08 Jun 2015 09:12:30 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z1wqm-0005RL-MV for qemu-devel@nongnu.org; Mon, 08 Jun 2015 09:12:29 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33070) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z1wlC-0002xY-3y for qemu-devel@nongnu.org; Mon, 08 Jun 2015 09:06:38 -0400 From: Stefan Hajnoczi Date: Mon, 8 Jun 2015 14:06:21 +0100 Message-Id: <1433768785-19413-6-git-send-email-stefanha@redhat.com> In-Reply-To: <1433768785-19413-1-git-send-email-stefanha@redhat.com> References: <1433768785-19413-1-git-send-email-stefanha@redhat.com> Subject: [Qemu-devel] [PULL v2 5/9] block: Fix dirty bitmap in bdrv_co_discard List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Kevin Wolf , Peter Maydell , Fam Zheng , Stefan Hajnoczi From: Fam Zheng 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 destination 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 Message-id: 1433742974-20128-5-git-send-email-famz@redhat.com Signed-off-by: Stefan Hajnoczi --- block/io.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/block/io.c b/block/io.c index ad6a76d..e4d7a59 100644 --- a/block/io.c +++ b/block/io.c @@ -2440,8 +2440,6 @@ int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, return -EPERM; } - bdrv_reset_dirty(bs, sector_num, nb_sectors); - /* Do nothing if disabled. */ if (!(bs->open_flags & BDRV_O_UNMAP)) { return 0; @@ -2451,6 +2449,8 @@ 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; -- 2.4.2