From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:41862) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S23Ml-0001kk-1O for qemu-devel@nongnu.org; Mon, 27 Feb 2012 11:24:05 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1S23Mj-0000zF-OY for qemu-devel@nongnu.org; Mon, 27 Feb 2012 11:23:58 -0500 Received: from mx1.redhat.com ([209.132.183.28]:58291) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S23Mj-0000z9-GS for qemu-devel@nongnu.org; Mon, 27 Feb 2012 11:23:57 -0500 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q1RGNupF030001 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 27 Feb 2012 11:23:56 -0500 From: Kevin Wolf Date: Mon, 27 Feb 2012 17:27:25 +0100 Message-Id: <1330360045-27198-1-git-send-email-kwolf@redhat.com> Subject: [Qemu-devel] [PATCH] qcow2: Fix offset in qcow2_read_extensions List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com The spec says that the length of extensions is padded to 8 bytes, not the offset. Currently this is the same because the header size is a multiple of 8, so this is only about compatibility with future changes to the header size. While touching it, move the calculation to a common place instead of duplicating it for each header extension type. Signed-off-by: Kevin Wolf --- block/qcow2.c | 5 ++--- 1 files changed, 2 insertions(+), 3 deletions(-) diff --git a/block/qcow2.c b/block/qcow2.c index dea12c1..f68f0e1 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -126,7 +126,6 @@ static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset, #ifdef DEBUG_EXT printf("Qcow2: Got format extension %s\n", bs->backing_format); #endif - offset = ((offset + ext.len + 7) & ~7); break; default: @@ -143,11 +142,11 @@ static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset, if (ret < 0) { return ret; } - - offset = ((offset + ext.len + 7) & ~7); } break; } + + offset += ((ext.len + 7) & ~7); } return 0; -- 1.7.6.5