qcow2_co_pwritev_compressed() should not call bdrv_truncate() if determining the size failed.
Reported-by: Markus Armbruster <arm...@redhat.com> Signed-off-by: Eric Blake <ebl...@redhat.com> --- block/qcow2.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/block/qcow2.c b/block/qcow2.c index 99407403ea..40ba26c111 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -3282,12 +3282,15 @@ qcow2_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset, z_stream strm; int ret, out_len; uint8_t *buf, *out_buf; - uint64_t cluster_offset; + int64_t cluster_offset; if (bytes == 0) { /* align end of file to a sector boundary to ease reading with sector based I/Os */ cluster_offset = bdrv_getlength(bs->file->bs); + if (cluster_offset < 0) { + return cluster_offset; + } return bdrv_truncate(bs->file, cluster_offset, PREALLOC_MODE_OFF, NULL); } -- 2.13.4