From patchwork Mon May 10 19:46:26 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Weil X-Patchwork-Id: 52135 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id BB15FB7D6B for ; Tue, 11 May 2010 05:47:21 +1000 (EST) Received: from localhost ([127.0.0.1]:57833 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OBYwh-00032p-3g for incoming@patchwork.ozlabs.org; Mon, 10 May 2010 15:47:19 -0400 Received: from [140.186.70.92] (port=35745 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OBYw8-00032k-Q1 for qemu-devel@nongnu.org; Mon, 10 May 2010 15:46:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OBYw7-0004G4-2u for qemu-devel@nongnu.org; Mon, 10 May 2010 15:46:44 -0400 Received: from moutng.kundenserver.de ([212.227.17.10]:51801) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OBYw5-0004ED-UW for qemu-devel@nongnu.org; Mon, 10 May 2010 15:46:42 -0400 Received: from flocke.weilnetz.de (p54ADED78.dip.t-dialin.net [84.173.237.120]) by mrelayeu.kundenserver.de (node=mrbap2) with ESMTP (Nemesis) id 0MSpj3-1NmRRs1RX3-00RtD5; Mon, 10 May 2010 21:46:33 +0200 Received: from stefan by flocke.weilnetz.de with local (Exim 4.71) (envelope-from ) id 1OBYvw-0002i9-20; Mon, 10 May 2010 21:46:32 +0200 From: Stefan Weil To: qemu-devel@nongnu.org Date: Mon, 10 May 2010 21:46:26 +0200 Message-Id: <1273520786-10385-1-git-send-email-weil@mail.berlios.de> X-Mailer: git-send-email 1.7.1 X-Provags-ID: V01U2FsdGVkX19DSQLRCzpwpAB4M+1ye3tHl5TfwuslrUFnVYm TEvgaaROlcQARGPAdxg+ktP62aL1z7QG0N6HDZmgRvsTLkvR/l 8iAzr6BiVcwKo9xuCxWUFL1h5mmVEc5Gne+s2YaNb31HEzIExD EJw== X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. Cc: Kevin Wolf Subject: [Qemu-devel] [PATCH] block/vpc: Fix conversion from size to disk geometry X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org The VHD algorithm calculates a disk geometry which is usually smaller than the requested size. QEMU tried to round up but failed for certain sizes: qemu-img create -f vpc disk.vpc 9437184 would create an image with 9435136 bytes (which is too small for qemu-img convert). Instead of hacking the geometry algorithm, the patch increases the number of sectors until we get enough sectors. Cc: Kevin Wolf Signed-off-by: Stefan Weil --- block/vpc.c | 21 ++++++++++++--------- 1 files changed, 12 insertions(+), 9 deletions(-) diff --git a/block/vpc.c b/block/vpc.c index f94e469..214e9d1 100644 --- a/block/vpc.c +++ b/block/vpc.c @@ -463,9 +463,7 @@ static int calculate_geometry(int64_t total_sectors, uint16_t* cyls, } } - // Note: Rounding up deviates from the Virtual PC behaviour - // However, we need this to avoid truncating images in qemu-img convert - *cyls = (cyls_times_heads + *heads - 1) / *heads; + *cyls = cyls_times_heads / *heads; return 0; } @@ -477,9 +475,9 @@ static int vpc_create(const char *filename, QEMUOptionParameter *options) struct vhd_dyndisk_header* dyndisk_header = (struct vhd_dyndisk_header*) buf; int fd, i; - uint16_t cyls; - uint8_t heads; - uint8_t secs_per_cyl; + uint16_t cyls = 0; + uint8_t heads = 0; + uint8_t secs_per_cyl = 0; size_t block_size, num_bat_entries; int64_t total_sectors = 0; @@ -496,9 +494,14 @@ static int vpc_create(const char *filename, QEMUOptionParameter *options) if (fd < 0) return -EIO; - // Calculate matching total_size and geometry - if (calculate_geometry(total_sectors, &cyls, &heads, &secs_per_cyl)) - return -EFBIG; + /* Calculate matching total_size and geometry. Increase the number of + sectors requested until we get enough (or fail). */ + for (i = 0; total_sectors > (int64_t)cyls * heads * secs_per_cyl; i++) { + if (calculate_geometry(total_sectors + i, + &cyls, &heads, &secs_per_cyl)) { + return -EFBIG; + } + } total_sectors = (int64_t) cyls * heads * secs_per_cyl; // Prepare the Hard Disk Footer