From e400ad1e1f0127b4fdabcb1c8de1e99be91788df Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Mon, 9 Oct 2017 23:55:31 +0200 Subject: [PATCH] qcow2: Fix unaligned preallocated truncation 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: Ping Li Bug: https://bugzilla.redhat.com/show_bug.cgi?id=1414049 Signed-off-by: Max Reitz Message-id: 20171009215533.12530-2-mreitz@redhat.com Cc: qemu-stable@nongnu.org Reviewed-by: Eric Blake Reviewed-by: Jeff Cody Reviewed-by: Stefan Hajnoczi 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 d3e114bce5..1ea763126d 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -3188,6 +3188,7 @@ 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); -- 2.30.2