From patchwork Fri Jun 12 14:57:50 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 483658 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 90E4F140218 for ; Sat, 13 Jun 2015 01:05:37 +1000 (AEST) Received: from localhost ([::1]:52051 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z3QWV-00043W-Ov for incoming@patchwork.ozlabs.org; Fri, 12 Jun 2015 11:05:35 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58861) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z3QPK-0007zZ-Fn for qemu-devel@nongnu.org; Fri, 12 Jun 2015 10:58:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z3QPG-0004s0-4X for qemu-devel@nongnu.org; Fri, 12 Jun 2015 10:58:10 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48337) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z3QPF-0004rw-VV for qemu-devel@nongnu.org; Fri, 12 Jun 2015 10:58:06 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (Postfix) with ESMTPS id 77287AB849; Fri, 12 Jun 2015 14:58:05 +0000 (UTC) Received: from localhost (ovpn-112-61.ams2.redhat.com [10.36.112.61]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t5CEw4eU009032; Fri, 12 Jun 2015 10:58:04 -0400 From: Stefan Hajnoczi To: Date: Fri, 12 Jun 2015 15:57:50 +0100 Message-Id: <1434121078-15776-3-git-send-email-stefanha@redhat.com> In-Reply-To: <1434121078-15776-1-git-send-email-stefanha@redhat.com> References: <1434121078-15776-1-git-send-email-stefanha@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: Kevin Wolf , Peter Maydell , Stefan Hajnoczi Subject: [Qemu-devel] [PULL 02/10] raw-posix: Fix .bdrv_co_get_block_status() for unaligned image size 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: Kevin Wolf Image files with an unaligned image size have a final hole that starts at EOF, i.e. in the middle of a sector. Currently, *pnum == 0 is returned when checking the status of this sector. In qemu-img, this triggers an assertion failure. In order to fix this, one type for the sector that contains EOF must be found. Treating a hole as data is safe, so this patch rounds the calculated number of data sectors up, so that a partial sector at EOF is treated as a full data sector. This fixes https://bugzilla.redhat.com/show_bug.cgi?id=1229394 Signed-off-by: Kevin Wolf Message-id: 1433840108-9996-1-git-send-email-kwolf@redhat.com Signed-off-by: Stefan Hajnoczi --- block/raw-posix.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/block/raw-posix.c b/block/raw-posix.c index 2990e95..44ade8c 100644 --- a/block/raw-posix.c +++ b/block/raw-posix.c @@ -1848,8 +1848,9 @@ static int64_t coroutine_fn raw_co_get_block_status(BlockDriverState *bs, *pnum = nb_sectors; ret = BDRV_BLOCK_DATA; } else if (data == start) { - /* On a data extent, compute sectors to the end of the extent. */ - *pnum = MIN(nb_sectors, (hole - start) / BDRV_SECTOR_SIZE); + /* On a data extent, compute sectors to the end of the extent, + * possibly including a partial sector at EOF. */ + *pnum = MIN(nb_sectors, DIV_ROUND_UP(hole - start, BDRV_SECTOR_SIZE)); ret = BDRV_BLOCK_DATA; } else { /* On a hole, compute sectors to the beginning of the next extent. */