Re: [Qemu-devel] [Qemu-block] [PATCH 4/4] qcow2: Check failure of bdrv_getlength()

[Jeff Cody <jcody@redhat.com>]

On Mon, Aug 07, 2017 at 03:30:07PM -0500, Eric Blake wrote:
> qcow2_co_pwritev_compressed() should not call bdrv_truncate()
> if determining the size failed.
> 
> Reported-by: Markus Armbruster <armbru@redhat.com>
> Signed-off-by: Eric Blake <eblake@redhat.com>



Reviewed-by: Jeff Cody <jcody@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
> 
>