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>
---
 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

On 08/07/2017 05:30 PM, 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: Philippe Mathieu-Daudé <f4bug@amsat.org>

> ---
>   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);
>       }
> 

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
> 
> 

Am 07.08.2017 um 22:30 hat Eric Blake geschrieben:
> 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: Kevin Wolf <kwolf@redhat.com>