Re: [Qemu-devel] [PATCH v2 2/3] qcow2: Do not mark inactive images corrupt

[Jeff Cody <jcody@redhat.com>]

On Wed, Jun 06, 2018 at 09:37:01PM +0200, Max Reitz wrote:
> When signaling a corruption on a read-only image, qcow2 already makes
> fatal events non-fatal (i.e., they will not result in the image being
> closed, and the image header's corrupt flag will not be set).  This is
> necessary because we cannot set the corrupt flag on read-only images,
> and it is possible because further corruption of read-only images is
> impossible.
> 
> Inactive images are effectively read-only, too, so we should do the same
> for them.  bdrv_is_writable() can tell us whether an image can actually
> be written to, so use its result instead of !bs->read_only.
> 
> (Otherwise, the assert(!(bs->open_flags & BDRV_O_INACTIVE)) in
> bdrv_co_pwritev() will fail, crashing qemu.)
> 
> Cc: qemu-stable@nongnu.org
> Signed-off-by: Max Reitz <mreitz@redhat.com>

Reviewed-by: Jeff Cody <jcody@redhat.com>

> ---
>  block/qcow2.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/block/qcow2.c b/block/qcow2.c
> index 6b2d88759d..6fa5e1d71a 100644
> --- a/block/qcow2.c
> +++ b/block/qcow2.c
> @@ -4569,7 +4569,7 @@ void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
>      char *message;
>      va_list ap;
>  
> -    fatal = fatal && !bs->read_only;
> +    fatal = fatal && bdrv_is_writable(bs);
>  
>      if (s->signaled_corruption &&
>          (!fatal || (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT)))
> -- 
> 2.17.0
>