From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43157) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e1g1f-0000Y2-Rn for qemu-devel@nongnu.org; Mon, 09 Oct 2017 17:55:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1e1g1c-0000Ho-KO for qemu-devel@nongnu.org; Mon, 09 Oct 2017 17:55:51 -0400 From: Max Reitz Date: Mon, 9 Oct 2017 23:55:31 +0200 Message-Id: <20171009215533.12530-2-mreitz@redhat.com> In-Reply-To: <20171009215533.12530-1-mreitz@redhat.com> References: <20171009215533.12530-1-mreitz@redhat.com> Subject: [Qemu-devel] [PATCH 1/3] qcow2: Fix unaligned preallocated truncation List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: qemu-devel@nongnu.org, Max Reitz , Kevin Wolf , Stefan Hajnoczi A qcow2 image file's length is not required to have a length that is a multiple of the cluster size. However, qcow2_refcount_area() expects an aligned value for its @start_offset parameter, so we need to round @old_file_size up to the next cluster boundary. Reported-by: pingl Bug: https://bugzilla.redhat.com/show_bug.cgi?id=1414049 Signed-off-by: Max Reitz --- block/qcow2.c | 1 + 1 file changed, 1 insertion(+) diff --git a/block/qcow2.c b/block/qcow2.c index 2f6a8e1ff8..c3b312cdef 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -3193,6 +3193,7 @@ static int qcow2_truncate(BlockDriverState *bs, int64_t offset, "Failed to inquire current file length"); return old_file_size; } + old_file_size = ROUND_UP(old_file_size, s->cluster_size); nb_new_data_clusters = DIV_ROUND_UP(offset - old_length, s->cluster_size); -- 2.13.6