From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1O7TJE-0002l8-2S for qemu-devel@nongnu.org; Thu, 29 Apr 2010 08:57:40 -0400 Received: from [140.186.70.92] (port=39343 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1O7TJC-0002jO-11 for qemu-devel@nongnu.org; Thu, 29 Apr 2010 08:57:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1O7TJ6-0004Qi-Tx for qemu-devel@nongnu.org; Thu, 29 Apr 2010 08:57:34 -0400 Received: from mx1.redhat.com ([209.132.183.28]:63419) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1O7TJ6-0004QX-Mg for qemu-devel@nongnu.org; Thu, 29 Apr 2010 08:57:32 -0400 Received: from int-mx04.intmail.prod.int.phx2.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.17]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o3TCvVjn006843 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Thu, 29 Apr 2010 08:57:31 -0400 From: Kevin Wolf Date: Thu, 29 Apr 2010 14:57:06 +0200 Message-Id: <1272545826-13287-1-git-send-email-kwolf@redhat.com> Subject: [Qemu-devel] [PATCH] qemu-img rebase: Fix output image corruption List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com qemu-img rebase must always give clusters in the COW file priority over those in the backing file. As it failed to use number of non-allocated clusters but assumed the maximum, it was possible that allocated clusters were taken from the backing file instead, leading to a corrupted output image. Signed-off-by: Kevin Wolf --- qemu-img.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-) diff --git a/qemu-img.c b/qemu-img.c index c21d999..d3c30a7 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -1136,7 +1136,7 @@ static int img_rebase(int argc, char **argv) if (!unsafe) { uint64_t num_sectors; uint64_t sector; - int n, n1; + int n; uint8_t * buf_old; uint8_t * buf_new; @@ -1155,8 +1155,8 @@ static int img_rebase(int argc, char **argv) } /* If the cluster is allocated, we don't need to take action */ - if (bdrv_is_allocated(bs, sector, n, &n1)) { - n = n1; + ret = bdrv_is_allocated(bs, sector, n, &n); + if (ret) { continue; } -- 1.6.6.1